IR heating Krishnamurthy article
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热浪滚烫的观后感500字英文版Here is the 600-word essay on the topic "Reflections on the Scorching Heat":The scorching heat has been relentless in recent weeks, enveloping the city in a suffocating blanket of oppressive temperatures. As the sun beats down mercilessly, the very air seems to shimmer with an intensity that saps the energy from even the most resilient of individuals. This heatwave has been a stark reminder of the power of nature and the vulnerability of our environment in the face of a rapidly changing climate.From the moment I step outside, the heat hits me like a physical force, weighing me down and making even the simplest tasks a challenge. The once-lively streets have become ghost towns, as people seek refuge in the cool respite of air-conditioned spaces, desperately trying to escape the relentless onslaught of the sun's rays. The pavement radiates a palpable heat, and the air is thick with the stifling humidity, making it difficult to breathe.The impact of this scorching heat extends far beyond the immediate discomfort it causes. It has disrupted the delicate balance of ourecosystem, with reports of heat-related illnesses and even fatalities on the rise. The intense temperatures have also placed a significant strain on our infrastructure, with power grids struggling to keep up with the increased demand for air conditioning and other cooling systems.Yet, amidst the adversity, I've been struck by the resilience and ingenuity of my fellow citizens. Neighbors have come together to check on the most vulnerable, offering support and assistance in the face of the challenges posed by the heatwave. Local community centers have opened their doors as cooling centers, providing respite and resources to those in need.The scorching heat has also served as a stark reminder of the urgent need to address the pressing issue of climate change. As the planet continues to warm, events like this heatwave are likely to become more frequent and more severe. It is a sobering reality that demands immediate action from policymakers, businesses, and individuals alike.In the face of this adversity, I am reminded of the importance of adaptability and preparedness. As a community, we must continue to seek innovative solutions to mitigate the impact of extreme weather events and build resilience in the face of a rapidly changing climate. This may involve investing in sustainable energy solutions, improvinginfrastructure to better withstand the effects of heat, and educating the public on the steps they can take to protect themselves and their loved ones.Despite the challenges, I remain hopeful that through collective action and a steadfast commitment to creating a more sustainable future, we can emerge from this heatwave stronger and more resilient than ever before. It is a testament to the power of the human spirit and our ability to come together in the face of adversity.As the sun finally sets and the temperatures begin to cool, I can't help but reflect on the lessons learned from this experience. The scorching heat has been a harsh reminder of the fragility of our existence and the urgent need to address the environmental challenges we face. But it has also shown me the incredible strength and resilience of my community, and the power of unity in the faceof a common foe.。
热胀冷缩的作文英语版80词Thermal Expansion and Contraction: A Fundamental Concept in Physics.Thermal expansion and contraction is a fundamental concept in physics that describes the change in size and volume of a material due to changes in temperature. This phenomenon is observed in various materials, including solids, liquids, and gases. The precise behavior of a material under thermal expansion and contraction depends on its physical properties and molecular structure.Solids.Solids typically exhibit a positive coefficient of thermal expansion, meaning that they expand upon heating and contract upon cooling. This is because the increased temperature causes the atoms and molecules within the solid to vibrate more vigorously, effectively increasing the interatomic spacing. As a result, the overall size andvolume of the solid increase. Some solids, however, can exhibit negative thermal expansion, where they contract upon heating and expand upon cooling. This behavior is observed in certain materials at specific temperature ranges and is associated with complex molecular arrangements.Liquids.Liquids generally exhibit positive thermal expansion coefficients as well. Upon heating, the increased molecular kinetic energy leads to a decrease in the average intermolecular distance, resulting in the expansion of the liquid's volume. However, unlike solids, liquids do not have a fixed shape and conform to the shape of their container. Therefore, the thermal expansion of liquids is primarily evident in terms of volume changes rather than linear or area changes.Gases.Gases exhibit the most significant thermal expansioncompared to solids and liquids. This is because the intermolecular spacing in gases is much larger than in condensed phases. As the temperature increases, the gas molecules move faster and collide more frequently,resulting in a substantial expansion of the gas's volume. The thermal expansion coefficient of gases is typically several orders of magnitude higher than that of solids and liquids.Applications and Consequences.Thermal expansion and contraction have numerous applications and consequences in various fields. In engineering, it is crucial to consider thermal expansion when designing structures and components to prevent damage or failure due to temperature fluctuations. For example, bridges and buildings are typically designed with expansion joints to accommodate thermal expansion and contraction.In the construction industry, thermal expansion can cause concrete structures to crack if proper measures are not taken to mitigate its effects. Similarly, in mechanicalengineering, thermal expansion can lead to differential expansion between different materials, which can cause wear and tear on moving parts.Conversely, thermal expansion can also be harnessed for beneficial purposes. For instance, in temperature sensors, a material's thermal expansion can be used to measure temperature changes. Additionally, in some medical applications, thermal expansion is utilized to activate drug delivery systems or adjust surgical instruments remotely.Understanding thermal expansion and contraction is essential for engineers, scientists, and anyone working with materials that undergo temperature changes. It helps to predict and mitigate potential risks, design more efficient systems, and exploit thermal expansion for various applications.。
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I recently conducted a fascinating experiment called the hot ice experiment. It was mind-blowing! Let me tell you all about it.So, picture this: I had a solution of sodium acetate and water in a beaker. It looked just like regular water, nothing special. But here's the crazy part when I heated it up, it didn't boil! Instead, it turned into a solidcrystal-like substance. Can you believe that? It was like magic happening right in front of my eyes.Now, let me explain the science behind this incredible transformation. When the sodium acetate solution is heated, it becomes supersaturated. This means that it holds more solute (the sodium acetate) than it normally should at that temperature. When the solution is disturbed or a seed crystal is added, it triggers the crystallization process,causing the liquid to solidify into a mass of crystals.It's like the solution is freezing, but without actually being cold. Isn't that mind-boggling?What's even more mind-blowing is that this solidified substance, also known as "hot ice," can stay in its solid state even when it's above its melting point. Yes, you heard that right it can be solid at temperatures higher than its melting point. It's like defying the laws of nature! This property of hot ice is known as supercooling.Now, to make things even more interesting, I decided to test the supercooling property of hot ice. I carefully heated the solid crystals to melt them, and then I let them cool down slowly without any disturbance. Surprisingly, the hot ice remained in its liquid state, even though it was below its melting point. It was like a liquid that didn't want to freeze! I couldn't believe my eyes.The hot ice experiment truly left me in awe of the wonders of science. It's incredible how a simple solution can turn into a solid crystal-like substance and defy thelaws of nature by remaining solid at high temperatures. This experiment not only taught me about the concept of supersaturation and supercooling but also reminded me of the endless possibilities that science has to offer. It's experiments like these that make me appreciate the beauty and complexity of the world we live in.。
高考英语口语考试真题及答案云南版全文共3篇示例,供读者参考篇1Hey everyone, it's me again with another inside scoop on the Gaokao. This time, I'm dishing all the details about the English speaking section for the Yunnan province version. You know how important English is for getting into a good university, so you'll want to read this carefully!First off, the structure of the speaking exam. It consisted of three parts: first there was a reading comprehension where you had to read a short passage and answer two questions about it. Next was the individual response where you had to choose one out of three topics and talk about it for 1-2 minutes. Finally, there was the roleplaying section where you got a scenario and had to act it out with the examiner.For the reading part, the passage was actually pretty manageable in length and difficulty level. Mine was about environmental protection and recycling. The two questions asked for key details from the passage, so as long as you understood the main points, you could answer them accurately.Pro tip: make sure to clearly state which part of the passage you are referring to when giving your answer.The individual response topics seemed pretty standard - things like describing a memorable experience, discussing an admirable person, talking about your future goals, etc. The key here is having a basic structure prepared that you can then adapt to whichever prompt you get. Something like a short intro, 2-3 main points with examples, and a conclusion. Also, try to sprinkle in some fancy vocab and grammar structures without going overboard.But let me tell you, the role play part was by far the trickiest! You don't get any time to prepare, the scenario is just sprung on you. For mine, I had to act as a student asking a clerk at the student center about joining an extracurricular club. Keeping up my character's persona while still producing coherent and contextually appropriate English responses on the fly was really challenging. My advice would be to practice, practice, practice doing improv conversations with others beforehand.In terms of evaluation criteria, I've been told fluency, pronunciation, grammar, vocabulary usage, and how well you respond to the actual prompts all factored in. Making silly little mistakes was okay, but having lots of awkward pauses or notproperly addressing what you were asked could really hurt your score.Of course, staying calm and confident is also huge. It's normal to feel nervous, but try your best not to let it show through things like mumbling or fidgeting. Speak slowly and clearly, and don't be afraid of a little bit of awkward silence while you gather your thoughts.One reassuring thing was that the evaluators seemed like pretty chill, supportive people overall. They didn't have intimidating poker faces and tried to put me at ease. As long as you make an earnest effort, I don't think they'll be too harsh in their judgement.So there you have it, all the insider deets on the Gaokao English speaking test for Yunnan! It's definitely a challenge, but if you prepare properly, you can definitely put your best foot forward. Let me know if you need any other tips or have questions. Wishing all my fellow test takers the best of luck - you've got this!篇2The Dreaded English Oral Exam: Yunnan's College Entrance Exam Strikes FearAs if the gauntlet of the college entrance exam wasn't tough enough, we students in Yunnan province have to contend with the dreaded English oral exam as well. This seemingly innocuous addition to the test has caused many a student to break out in a cold sweat. After all, isn't it hard enough to master written English? Now we have to demonstrate oral fluency too? The pressure is immense.I'll never forget my own experience with the English oral exam two years ago. I had been diligently preparing by watching English movies, listening to podcasts, and even talking to myself in the mirror to practice. But when I stepped into that small room with the examiners staring me down, my mind went blank.The first question they asked was deceptively simple: "Tell us about your favorite book and why you enjoyed it." I stammered through some jumbled thoughts about the sci-fi novel I had read, rambling aimlessly until they had to move me along to the next question mercifully.From there, it didn't get any easier. They fired off questions about my future goals, current events, even asking my opinion on government policies. With each query, I felt more tongue-tied and flustered. By the end, I could have filled a swimming pool with the cold sweat dripping down my back.Needless to say, I didn't exactly ace the oral portion. Luckily, my written English exam scores were strong enough to buoy my overall grade. But I shudder to think about my poor classmates who struggled with both the written and spoken components. The oral exam seems almost designed to causthem maximum anxiety.As this year's English oral exams get underway, I can't help but sympathize with the students sweating it out. To help them out, I've compiled some of the actual questions given this year along with sample answers that earned top marks:Question: What are your thoughts on climate change? What steps can individuals take to reduce their carbon footprint?Sample Answer: Climate change is one of the most pressing issues facing our world today. The effects of rising global temperatures, melting ice caps, and increasing extreme weather events will be absolutely devastating if not addressed. On an individual level, we can all do our part by reducing energy consumption, taking public transportation, eating less meat, and being diligent about recycling. Collective action through sustainable practices is crucial to curbing our carbon emissions and protecting the environment for future generations.Question: Tell me about a major historical figure you admire and why you look up to them.Sample Answer: One historical figure I greatly admire is Malala Yousafzai, the Pakistani activist for female education and the youngest Nobel Prize laureate. What I find so inspiring about Malala is her unwavering courage and commitment to her cause, even after being shot in the head by the Taliban for daring to want an education. Rather than being cowed by this horrific act, Malala has doubled down on her advocacy, drawing global attention to the educational inequalities and human rights abuses girls face in parts of the world. Her resilience, eloquence, and steadfast dedication to creating a better world for girls and women everywhere is something I aspire to emulate.Question: What is your opinion on the growing role of artificial intelligence in daily life? What are the potential benefits and drawbacks?Sample Answer: Artificial intelligence is rapidly becoming integrated into our daily lives through technologies like virtual assistants, facial recognition, and self-driving vehicles. While AI undoubtedly offers many potential benefits in terms of efficiency, automation, and insight through data analysis, I also have concerns about the implications for privacy, security, and humanrights. We must be prudent that the algorithms powering AI are not harboring unconscious biases that perpetuate discrimination. There are also thorny ethical questions around ceding certain decisions to machines rather than human discretion. Ultimately, I believe AI should be a tool that enhances and complements human capabilities while following a robust ethical framework - not a replacement for human judgment altogether.As torturous as the English oral exam was for me, mastering spoken fluency is a critical skill for success in our increasingly globalized world. My struggle was a humbling lesson in overcoming fears, thinking on my feet, and rolling with the punches. To all my fellow students facing the ordeal this year, the best advice I can give is: be prepared for anything, stay calm and confident, and don't stress too much over any single question. The oral exam judges overall command of the language, not perfection. You've got this!篇3Sure, here's an article about "Authentic Yunnan High School English Oral Test Questions and Answers" written from a student's perspective, with a length of around 2000 words in English.The Nerve-Wracking English Oral Exam: Yunnan's High School AdventureAs students in Yunnan, the English oral exam was the stuff of nightmares. The mere mention of it sent shivers down our spines and prompted frantic last-minute cramming sessions. Yet, despite our best efforts, the unpredictable nature of the test left us feeling like we were venturing into uncharted territory every single time.One year, the topic was "Environmental Protection" – a subject we thought we had a decent grasp on. Little did we know that the examiner would throw us a curveball by asking about the intricate details of carbon footprint calculations. Needless to say, our carefully rehearsed speeches about recycling and energy conservation went out the window faster than a plastic bottle tossed into a landfill.Another year, the topic was "Technology and Its Impact on Society." We diligently prepared our talking points, covering everything from the rise of social media to the ethical implications of artificial intelligence. However, the examiner decided to focus exclusively on the nuances of blockchain technology, leaving us scrambling to string together coherentsentences about decentralized ledgers and cryptographic hashing.Then there was the year when the topic was "Cultural Traditions in China." We meticulously studied the history and significance of various festivals, prepared to wax poetic about the beauty of Chinese calligraphy and the intricacies of traditional cuisine. But the examiner had other plans. They inquired about the obscure rituals of minority ethnic groups we had barely scratched the surface of, leaving us floundering like fish out of water.Despite the challenges, we persevered, always hoping that the next year's topic would be the one we had thoroughly mastered. We practiced our pronunciation, expanded our vocabularies, and rehearsed our responses until our tongues felt like they would fall off. Yet, the English oral exam continued to be a formidable foe, testing not only our language skills but also our ability to think on our feet and adapt to the unexpected.One particular year, the topic was "Travel and Adventure." We eagerly prepared our tales of daring escapades andawe-inspiring destinations, only to be met with a barrage of questions about the logistics of travel planning and the environmental impact of tourism. Suddenly, our grand stories ofscaling mountains and exploring exotic locales seemed irrelevant, and we found ourselves grasping for information about carbon offsets and sustainable travel practices.Through it all, we learned valuable lessons about resilience, quick thinking, and the importance of having a diverse knowledge base. We discovered that the English oral exam wasn't just about regurgitating memorized facts but about demonstrating our ability to communicate effectively, even in the face of curveballs.As we look back on those nerve-wracking experiences, we can't help but chuckle at the absurdity of some of the questions we encountered. Yet, we also feel a sense of pride for having survived the gauntlet that was the Yunnan High School English Oral Exam. And who knows? Maybe one day, we'll be the ones crafting the questions, ensuring that the next generation of students faces their own unique set of challenges and learns the invaluable art of thinking on their feet.。
克劳德•麦凯《回到哈莱姆》中的跨国书写舒进艳内容摘要:克劳德•麦凯的《回到哈莱姆》描摹了20世纪早期的黑人跨国体验。
学界主要阐释了作者个人的跨国经历与黑人国际主义思想对小说塑造主要人物的影响,而忽视了小说中副线主人公雷的国籍及其旅居哈莱姆的意义。
雷的跨国移民经历既再现了麦凯的复杂跨国情感与认同经历,又观照了哈莱姆作为流散非裔移居的理想家园与城市黑人社区所承载的空间意涵。
论文提出哈莱姆具有三个维度,作为移民唤起历史记忆的地理空间、建构跨国身份的政治空间及容纳差异的多元文化空间,并考察移民在跨国流动中历经的现代性体验,以此揭示他们通过改变既定身份与重新定义自我而竭力摆脱传统的民族、种族和阶级观念的束缚与身份认同的困惑,从而参与到美国城市的种族空间生产中。
关键词:克劳德•麦凯;《回到哈莱姆》;跨国书写基金项目:本文系国家社会科学重大项目“美国文学地理的文史考证与学科建构”(项目编号:16ZDA197);天津市研究生科研创新项目“美国新现实主义小说的跨国空间研究”(项目编号:19YJSB039)的阶段性研究成果。
作者简介:舒进艳,南开大学外国语学院博士研究生、喀什大学外国语学院副教授,主要从事美国文学研究。
Title: Claude Mckay’s Transnational Writing in Home to HarlemAbstract: Claude McKay’s Home to Harlem depicts the black transnational experience of the early 20th century. Academics mainly studied the influence of McKay’s personal transnational experience and black internationalist thinking on his main character, but neglected the minor plot’s protagonist Ray and his nationality, and the significance of his sojourn in Harlem. Ray’s transnational migration experience not only embodies McKay’s complex transnational feeling and identity experience, but also reflects Harlem’s spatial significance as an ideal home for African diaspora and urban black community. The paper aims to examine Caribbean immigrants’ experience of modernity in Harlem which is interpreted as the geographic space for immigrants to evoke historical memories, the political space for constructing transnational identities and the multicultural space for accommodating differences. It is to prove that they manage to extricate themselves from the shackles of traditional concepts of nation, race and class and their confusion of identity by changing their established identity and redefining themselves, and thus participate in the production of racial space in American cities.60Foreign Language and Literature Research 2 (2021)外国语文研究2021年第2期Key words: Claude Mckay; Home to Harlem; transnational writingAuthor: Shu Jinyan is Ph. D. candidate at College of Foreign Languages, Nankai University (Tianjin, 300071, China), associate professor at School of Foreign Studies, Kashi University (Kashi 844000, China). Her major academic research interest includes American literature. E-mail: ******************1925年,阿伦•洛克在《新黑人》选集中将哈莱姆描述为一个国际化的文化之都,视其重要性堪比欧洲新兴民族国家的首都。
Sauna is a traditional form of heat bathing that has its roots in Finland, though it has since spread across the globe and become a popular method of relaxation and therapy. The experience of a sauna is unique and offers a variety of benefits, both physical and mental. Here, we will delve into the distinctive characteristics of saunas, exploring their design, temperature, and the overall experience they provide.The design of a sauna is one of its most notable features. Traditional saunas are constructed from wood, often using spruce or pine, which not only provides a natural and warm aesthetic but also emits a pleasant aroma when heated. The interiors are typically simple, with wooden benches arranged in tiers to accommodate multiple users, and a stove in the center where heated rocks are placed. Modern saunas may incorporate various technologies, such as digital temperature controls and lighting, but the essence of the traditional design remains.Temperature is a critical aspect of the sauna experience. Traditional saunas can reach temperatures of up to 90 degrees Celsius 194 degrees Fahrenheit, although the average is usually around 80 degrees Celsius 176 degrees Fahrenheit. This intense heat is designed to induce sweating, which helps to detoxify the body by releasing impurities through the skin. The heat also dilates blood vessels, increasing blood circulation and promoting muscle relaxation.One of the most enjoyable aspects of a sauna is the sensory experience it provides. The warmth envelops the body, creating a sense of comfort and relaxation. Many saunas are equipped with a bucket of water and a ladle,which users can pour over the heated rocks to create steam. This steam, combined with the heat, intensifies the saunas effects and adds a layer of humidity that can be soothing to the respiratory system.The use of essential oils or eucalyptus is another common practice in saunas. These scents not only enhance the ambiance but also contribute to the therapeutic effects of the sauna. Eucalyptus, for example, is known for its decongestant properties and can help to clear the sinuses.Saunas also offer a social aspect that is unique to the experience. In many cultures, saunas are a communal space where friends and family gather to enjoy the heat together. This social aspect can foster a sense of camaraderie and relaxation, as individuals share the experience and engage in conversation.The health benefits of saunas are welldocumented. Regular sauna use has been linked to improved cardiovascular health, reduced stress levels, and even enhanced immune function. The heat can help to alleviate muscle soreness and joint pain, making saunas a popular choice for athletes and those dealing with chronic pain conditions.In addition to the physical benefits, saunas also offer mental health benefits. The tranquil environment and the act of sweating can help to clear the mind and reduce stress. Many people find that a session in the sauna allows them to unwind and decompress after a long day.In summary, saunas are a unique and multifaceted experience that offers arange of physical and mental health benefits. From the traditional wooden design to the intense heat and sensory experience, saunas provide a space for relaxation, socialization, and therapeutic healing. Whether you are seeking a way to unwind after a stressful day or looking to improve your overall health, a sauna session may be just what you need.。
气温攀升学术英语作文Title: The Escalation of Temperature: A Global Academic Perspective。
Introduction。
The escalation of temperature has emerged as a critical concern in contemporary discourse, transcending geographical boundaries and disciplinary confines. This essay delves into the multifaceted dimensions of rising temperatures, encompassing scientific, environmental, and societal implications.Scientific Understanding。
At the core of the discussion lies the scientific understanding of temperature escalation. Over the past century, anthropogenic activities, notably the combustion of fossil fuels and deforestation, have significantly contributed to the amplification of greenhouse gases in theatmosphere. These gases, including carbon dioxide and methane, trap heat, leading to a phenomenon known as the greenhouse effect. Consequently, global temperatures have witnessed a steady rise, manifesting in phenomena such as global warming and climate change.Environmental Ramifications。
全球变暖的新闻英文作文Title: The Melting Ice: Global Warming's Unseen Reality。
1. (Randomness 1)。
Imagine a world where glaciers, once eternal sentinelsof cold, now shimmer with a faint glow. The Arctic's Arctic Vortex, once a place of unyielding silence, now hums withthe rhythmic groan of melting ice. It's not a forecast, but a stark reality that's been playing out on our planet's stage.2. (Randomness 2)。
In the heart of the Amazon, the once lush rainforestnow whispers secrets of drought. The Amazon River, once alife-giving force, now struggles with reduced flow, a symptom of the relentless heat. It's not a choice, but a testament to the relentless march of global warming.3. (Randomness 3)。
The Antarctic, the last ice frontier, is witnessing a retreat that's not just a change, but a transformation. The penguin colonies, once teeming with life, now face a future where their icy homes are slowly disappearing. It's not a trend, but a crisis that's altering the balance of our planet.4. (Randomness 4)。
乔丹普尔英文作文Title: The Enigmatic Jordan Pool。
Jordan Pool is a fascinating phenomenon, a confluence of natural beauty and historical intrigue. Nestled amidst the verdant hills of the countryside, it beckons travelers with its serene waters and picturesque surroundings. However, beneath its tranquil facade lies a tapestry woven with tales of legend and mystery.First and foremost, Jordan Pool is renowned for its crystalline waters, which have been likened to liquid sapphires glistening under the sun. Its pristine clarity reflects the azure sky above, creating a mesmerizing spectacle that captivates all who behold it. The pool's refreshing depths offer respite from the sweltering summer heat, drawing visitors from far and wide to immerse themselves in its cool embrace.Yet, beyond its aesthetic allure, Jordan Pool harborssecrets that date back centuries. According to local folklore, the pool is said to be enchanted, imbued with mystical energies that grant it healing properties. Legend has it that those who bathe in its waters are blessed with renewed vitality and longevity, their ailments washed away by the pool's magical touch. While skeptics may dismiss such tales as mere superstition, the enduring belief in Jordan Pool's curative powers continues to attract pilgrims seeking solace and restoration.Moreover, Jordan Pool occupies a pivotal place in the annals of history, its shores bearing witness to the ebb and flow of civilization. Archaeological excavations have uncovered artifacts dating back to antiquity, hinting at the pool's significance as a sacred site of worship and ritual. Ancient inscriptions etched into nearby cliffs speak of offerings made to appease the deities believed to preside over the waters, underscoring the reverence with which Jordan Pool was held by generations past.In addition to its spiritual and historical resonance, Jordan Pool serves as a haven for biodiversity, supportinga rich tapestry of flora and fauna. The surrounding ecosystem teems with life, from the delicate blooms of water lilies to the melodious trill of songbirds perched in the canopy above. Beneath the surface, a vibrant community of aquatic creatures thrives, their intricate dance hidden from view beneath the tranquil veneer of the water's surface.Despite its idyllic charm, Jordan Pool is not without its challenges. Over the years, human encroachment and environmental degradation have taken their toll on this fragile ecosystem. Pollution from urban runoff and agricultural practices threatens the water quality, while deforestation and habitat destruction diminish the pool's natural splendor. Efforts to preserve and protect Jordan Pool have thus become paramount, as stakeholders strive to strike a balance between conservation and sustainable development.In conclusion, Jordan Pool stands as a testament to the enduring bond between humanity and the natural world. Its timeless beauty and enigmatic allure continue to captivatehearts and minds, inspiring awe and reverence in all who behold it. As custodians of this precious resource, it is our collective responsibility to safeguard Jordan Pool for future generations, ensuring that its legacy endures for millennia to come.。
鸡尾酒疗法英语作文Title: The Therapeutic Elixir: Exploring the World of Cocktails。
In the realm of mixology, where spirits meet creativity, lies a realm of possibility known as cocktail therapy. This fusion of art and science has captivated both connoisseurs and curious minds alike, offering not only a delightful sensory experience but also a potential avenue for therapeutic benefits.At its core, cocktail therapy involves the mindful consumption of well-crafted cocktails, each concoction tailored to evoke certain emotions or sensations. Through the careful selection and combination of ingredients, mixologists aim to create drinks that not only tantalizethe taste buds but also soothe the soul.One of the key elements of cocktail therapy is the useof aromatic ingredients, such as herbs, spices, andbotanicals, which have long been associated with various health benefits. For example, the inclusion of fresh mintin a mojito not only adds a refreshing flavor but also aids in digestion and promotes relaxation. Similarly, the addition of ginger in a Moscow Mule can help alleviate nausea and improve circulation.Moreover, the act of crafting and savoring cocktails can be a form of mindfulness practice, allowing individuals to be fully present in the moment and engage their senses. From the meticulous muddling of ingredients to the precise pouring of spirits, every step in the cocktail-making process invites mindfulness and intentionality.Furthermore, the social aspect of cocktail therapy should not be overlooked. Sharing a well-crafted drink with friends or loved ones can foster connections and create a sense of community. Whether it's gathering around a bar or hosting a cocktail party at home, the shared experience of enjoying cocktails can strengthen bonds and provide much-needed support.It's important to note that cocktail therapy is not a substitute for professional medical treatment or therapy. However, when enjoyed responsibly and in moderation, cocktails can complement other wellness practices and enhance overall well-being.In conclusion, cocktail therapy offers a unique blend of sensory delight, mindfulness, and social connection. By embracing the art of mixology and savoring thoughtfully crafted drinks, individuals can embark on a journey ofself-discovery and relaxation. So, let's raise a glass to the therapeutic elixir that is the cocktail, and toast to the joys of mindful indulgence. Cheers!。
2024学年山西省晋城市陵川一中高考冲刺押题(最后一卷)英语试卷考生请注意:1.答题前请将考场、试室号、座位号、考生号、姓名写在试卷密封线内,不得在试卷上作任何标记。
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第一部分(共20小题,每小题1.5分,满分30分)1.Whitney Houston’s sudden death suggests that dr ug abuse is such a serious problem ________ we should deal with it appropriately.A.as B.that C.which D.where2.If they throw stones at you,don’t throw e them to build your own foundation ________.A.somehow B.anywayC.instead D.nevertheless3.--- Do you think I should join the singing group, Mary?--- ______ If I were in your shoes, I certainly would.A.None of your business.B.It depends.C.Why not? D.I don’t think so.4.— What great changes have taken place in our city in the last few years!— Indeed, many high buildings have _______all over the city.A.wound up B.sprung up C.held up D.made up5.In my driving lesson, a traffic rule that impressed me most is that in no time ________ when the traffic lights turn red. A.all vehicles should stop B.should all vehicles stopC.should stop all vehicles D.should stop all vehicles6.So far, only one man has ________ a theory that seems to fit all the facts.A.come up with B.put up withC.lined up with D.caught up with7.The new product is beyond all praise and has quickly taken over the market ________ its superior quality.A.in terms of B.on account ofC.on behalf of D.on top of8.Countries which continue importing huge quantities of waste will have to____ the issue of pollution.A.maintain B.simplify C.overlook D.address9.Nobody can go back and start a new beginning, ______ anyone can start now and make a new ending.A.for B.andC.but D.so10.If you sleep less than seven hours, you are three times more to catch a cold.A.possible B.certainly C.probable D.likely11.We believe ________ you have been devoted to ________ naturally of great necessity.A.that; being B.all that; beC.that all; are D.what; is12.—I’m afraid I couldn’t go to your birthday party.I have a test next Monday.—Oh,!You’re my best friend and you must be there!A.go ahead B.come on C.you needn’t D.it doesn’t matter13.She is quite____to office work.You had better offer her some suggestions when necessary.A.familiar B.freshC.similar D.sensitive14.Time is pressing.You cannot start your task _____ soon.A.too B.very C.so D.as15.-Do you really mean it when you say he will a good president?A.judge B.duit C.turn D.Serve16.---We want someone to design the new art museum for me.---_____ the young fellow have a try?A.Shall B.May C.Will D.Need17.Last December China _____ 100 Chinese and 10 foreigners for their outstanding contributions to the country’s reform and opening-up.A.distinguished B.sponsoredC.acknowledged D.evaluated18.— Did you go to last night’s concert?— Y es. And the girl playing the violin at the concert _______ all the people present with her excellent ability.A. impressed B.compared C.conveyed D.observed19.If I can help , I don’t like working late into the night.A.so B.that C.them D.it20.—Sorry, I didn’t hear the door bell ring.—Your bell . Perhaps it needs repairing.A.never worked B.is never workingC.never works D.had never worked第二部分阅读理解(满分40分)阅读下列短文,从每题所给的A、B、C、D四个选项中,选出最佳选项。
考证热的英语作文Investigating the Concept of Heat。
Heat is a form of energy that is transferred from one body to another as a result of a difference in temperature. It is a fundamental concept in physics and plays a vital role in our daily lives. In this essay, we will explore the nature of heat, its properties, and its various applications.The Nature of Heat。
Heat is a form of energy that is transferred from one body to another as a result of a difference in temperature. It is a measure of the internal energy of a system, and its flow is always from a hotter object to a colder one. Heat can be transferred through three mechanisms: conduction, convection, and radiation.Conduction is the transfer of heat through a materialwithout any net movement of the material itself. For example, when you touch a hot stove, heat is transferred to your hand through conduction. Convection is the transfer of heat through the movement of a fluid, such as air or water. For example, when you feel a breeze on a hot day, heat is being transferred away from your body through convection. Radiation is the transfer of heat through electromagnetic waves, such as light or infrared radiation. For example, the sun transfers heat to the Earth through radiation.The Properties of Heat。
人造小太阳可控核聚变作文英文回答:Artificial Controlled Nuclear Fusion.Nuclear fusion, the process of combining light atomic nuclei to form heavier ones, has long been a subject of scientific exploration and research. It holds the promise of providing clean and virtually limitless energy for our planet. In recent years, scientists and engineers have made significant progress in developing controlled nuclear fusion, and one of the most exciting advancements is the creation of an artificial small sun.The concept of an artificial small sun is based on the idea of creating a miniature version of the sun here on Earth. By replicating the conditions found in the core of the sun, scientists aim to harness the immense power of nuclear fusion. The goal is to achieve a self-sustaining fusion reaction that can generate large amounts of energy.To achieve controlled nuclear fusion, scientists use a device called a tokamak. This device consists of a toroidal vacuum chamber surrounded by powerful magnets. Inside the chamber, a mixture of hydrogen isotopes, such as deuterium and tritium, is heated to extremely high temperatures, creating a plasma state. The strong magnetic field confines the plasma, preventing it from touching the walls of the chamber and causing damage.The plasma is then subjected to powerful heating methods, such as radiofrequency waves or neutral beam injection, to increase its temperature and pressure. As the plasma reaches the necessary conditions, the hydrogen isotopes collide and fuse together, releasing a tremendous amount of energy in the process. This energy can be captured and converted into electricity, providing a clean and sustainable source of power.The development of an artificial small sun has numerous advantages. Firstly, it offers a solution to the global energy crisis by providing a virtually unlimited source ofclean energy. Unlike fossil fuels, which contribute to climate change and pollution, nuclear fusion does not produce greenhouse gases or radioactive waste. Secondly,the technology behind controlled nuclear fusion can be used for various applications, such as powering spacecraft or generating electricity for remote areas. Lastly, theartificial small sun has the potential to revolutionize the way we think about energy, paving the way for a sustainable and environmentally friendly future.中文回答:人造小太阳可控核聚变。
你该如何散热英语作文Title: Efficient Heat Dissipation Methods。
Introduction:Effective heat dissipation is crucial for maintaining the optimal operating temperature of electronic devices, preventing overheating, and ensuring their longevity and performance. In this essay, we will explore various methods and techniques for efficient heat dissipation.1. Thermal Design: 。
Efficient heat dissipation begins with the thermal design of the electronic device. This involvesstrategically placing components, such as processors and heat sinks, to maximize airflow and heat transfer.2. Heat Sinks:Heat sinks are passive cooling devices that absorb and dissipate heat away from electronic components. They are typically made of materials with high thermal conductivity, such as aluminum or copper. Properly sized and positioned heat sinks can significantly enhance heat dissipation.3. Fans and Ventilation:Active cooling methods, such as fans and ventilation systems, are commonly used to improve heat dissipation. Fans generate airflow over heat sinks and other components, facilitating heat transfer to the surrounding environment. Proper ventilation design ensures the efficient removal of hot air and the intake of cooler air.4. Thermal Interface Materials (TIMs):TIMs are substances applied between electronic components and heat sinks to improve thermal conductivity and reduce thermal resistance. Common TIMs include thermal greases, pads, and phase-change materials. Using high-quality TIMs enhances heat transfer and improves overall thermal performance.5. Liquid Cooling Systems:Liquid cooling systems are increasingly being adopted for high-performance electronic devices, such as gaming PCs and servers. These systems use a circulating fluid to absorb heat from components and transfer it to a radiator, where it is dissipated into the surrounding air. Liquid cooling offers superior heat dissipation capabilities compared to air cooling.6. Thermal Management Software:Advanced electronic devices often employ thermal management software to monitor temperature levels and adjust cooling mechanisms accordingly. These software solutions can optimize fan speed, regulate component power consumption, and provide real-time feedback on thermal performance.7. Heat Pipes:Heat pipes are heat transfer devices thatefficiently conduct heat away from electronic components using phase-change principles. They consist of a sealed tube containing a working fluid, such as water or refrigerant, which evaporates at the hot end and condenses at the cooler end, releasing heat in the process. Heat pipes are particularly effective for transferring heat over long distances with minimal thermal resistance.8. Thermal Design Considerations:In addition to implementing specific heatdissipation methods, careful consideration must be given to the overall thermal design of electronic devices. Factors such as component layout, enclosure design, and ambient temperature conditions can significantly impact thermal performance.Conclusion:Efficient heat dissipation is essential for maintaining the reliability and performance of electronic devices. By employing a combination of passive and active cooling methods, along with careful thermal design considerations, engineers can ensure optimal thermal management and prolong the lifespan of electronic products.This essay has explored various techniques forefficient heat dissipation, including the use of heat sinks, fans, liquid cooling systems, thermal interface materials, heat pipes, and thermal management software. By implementing these methods effectively, electronic devices can operate within safe temperature limits, minimizing the risk of overheating and maximizing performance.。
The Phenomenon of Fanaticism: A Deep Dive into the World of Celebrity WorshipIn today's digital era, the phenomenon of fanaticism has taken center stage, particularly in the realm of celebrity worship. With the advent of social media and the rise of influencers, individuals are more connected totheir favorite stars than ever before. This obsession with celebrities has given rise to a unique culture where fans go to extraordinary lengths to support, admire, and emulate their idols.The roots of this mania can be traced back to the desire for connection and belongingness. In a world where people are constantly connected through digital platforms, following a celebrity becomes a way to feel part of alarger community. Fans identify with their favorite stars, finding common ground in their interests, values, or even their life stories. This shared experience creates a sense of belonging that is often difficult to find in today's fragmented society.However, this obsession with celebrities can sometimes go too far. Some fans engage in unhealthy behaviors such asstalking, cyberbullying, or even spending exorbitant amounts of money on merchandise and tickets. This extreme fanaticism can have negative consequences not only for the fans themselves but also for the celebrities they admire.It can lead to privacy invasions, emotional distress, and even financial ruin.Moreover, the rise of fanaticism has also given birth to a new breed of influencers who capitalize on their fame for personal gain. These celebrities often have a significant impact on their followers, especially young and impressionable minds. Their endorsements and opinions can shape the buying habits, values, and even political leanings of their followers. This influence can be both positive and negative, depending on how the celebrity chooses to wield it.In conclusion, the phenomenon of fanaticism is a complex and multifaceted issue that deserves further examination. While it can bring people together and create a sense of community, it can also lead to unhealthy behaviors and negative consequences. It is important for both fans and celebrities to maintain a healthy balance intheir relationship, respecting each other's boundaries and promoting positive values.**追星热现象:深入剖析名人崇拜的世界**在当今数字化时代,追星热现象已经成为中心议题,特别是在名人崇拜领域。
写《热辣滚烫》用由悟理法的英语作文英文回答:"Tropic Thunder": A Meta-Commentary on Hollywood."Tropic Thunder" is a 2008 American satirical action comedy film directed by Ben Stiller and co-written by Stiller, Justin Theroux, and Etan Cohen. It stars Stiller, Robert Downey Jr., Jack Black, Jay Baruchel, and Danny McBride.The film follows a group of actors who are filming a war film in Southeast Asia when they encounter real-life combat. The film is a parody of war films, action films, and Hollywood in general. It satirizes the excess, ego, and greed that are often associated with the film industry.One of the most notable things about "Tropic Thunder" is its use of black humor. The film is full of dark jokes and offensive language. This may be off-putting to someviewers, but it is essential to the film's satire. The black humor helps to highlight the absurdity and hypocrisy of the film industry.Another notable aspect of "Tropic Thunder" is its performances. The entire cast is excellent, but Downey Jr. is particularly memorable as Kirk Lazarus, an Australian actor who undergoes surgery to portray an African-American soldier. Lazarus is a walking stereotype, but Downey Jr. plays him with such sincerity and conviction that he becomes a sympathetic character."Tropic Thunder" is a sharp and funny satire of Hollywood. It is a must-see for fans of comedy and film criticism.中文回答:《热辣滚烫》,对好莱坞的元评论。
硝酸铵乳胶在持续受热条件下的热失控特性徐森;陈相;段瑞坤;刘大斌;潘峰【摘要】To study the thermal runaway of emulsion matrix under continuous heating in a fire, TG and ARC were employed to detect its thermal decomposition characteristics, and modified vented pipetest(MVPT) recommended by UN for the transport of dangerous goods did to measure the temperature evolution of sample. The TG and ARC test results show that the higher water content of emulsion matrix, the easierits demulsification, and the lower heat released by reaction is. In the MVPT test, sample temperature rises slowly between 100-146℃, and above 146℃raise of temperature speeds up quickly, indicating appearance of obvious exothermic reaction process. When the temperature is up to 270℃, emulsion matrix takes place thermal runaway reaction (explosion). So the control of emulsion matrix temperature is very important for its transportation and storage safety.%为了研究乳胶基质在运输过程中在火灾条件下持续受热的热失控发展过程,采用TG和ARC研究了乳胶基质的热分解特性,同时采用联合国橘黄书中改进的通风管试验分析研究了乳胶基质在持续受热条件下发生热爆炸的过程。
烤制新英格兰龙虾英语作文Grilled New England LobsterNew England lobster is a delicacy cherished by many seafood lovers around the world. The sweet, succulent meat of thelobster is a true delight to the taste buds. One popular way to prepare and enjoy New England lobster is by grilling it.Grilling lobster enhances its natural flavors and gives it a delicious smoky char. In this essay, we will explore the steps to properly grill New England lobster to perfection.To begin, you will need fresh New England lobsters. It is important to use live lobsters for the freshest and besttasting results. Before grilling, you will need to prepare the lobsters by carefully splitting them in half. This can be done by first chilling the lobsters in the freezer for about 20 minutes to numb them. Then, place the lobster on a cutting board, bellyside down, and carefully cut through the head with a sharp knife, all the way down to the tail.Next, gently pry open the lobster shell to reveal the meat inside. Remove the black vein that runs down the length of the tail, as it can impart a bitter taste to the meat when grilled. You can also remove the tomalley (the green substance found in the body cavity) if desired, although some people enjoy its unique flavor.Once the lobsters are prepped, it's time to season them before grilling. A simple yet flavorful seasoning for grilled lobster includes a mixture of melted butter, minced garlic, chopped parsley, salt, and pepper. Brush this mixture generously over the lobster meat, ensuring that it is well coated.Preheat your grill to mediumhigh heat and place the lobster halves on the grill, shellside down. Grill the lobsters for about 57 minutes, or until the meat is opaque and firm, and the shell is charred. Be careful not to overcook the lobster, as it can become tough and rubbery.Once the lobsters are cooked to perfection, carefully remove them from the grill and serve hot. You can garnish the grilled lobsters with additional melted butter and fresh lemon wedgesfor extra flavor. Pair them with your favorite side dishes, such as corn on the cob or a fresh garden salad, for a complete and satisfying meal.In conclusion, grilling New England lobster is a delicious way to enjoy this exquisite seafood. By following these simple steps and techniques, you can create a mouthwatering dish that will impress your family and friends. So fire up the grill, grab some fresh lobsters, and get ready to savor the irresistible flavors of grilled New England lobster.。
Infrared Heatingin FoodProcessing:AnOverviewKathiravan Krishnamurthy,Harpreet Kaur Khurana,Soojin Jun,Joseph Irudayaraj,and Ali DemirciABSTRACT:Infrared(IR)heatingprovidessignificantadvantagesoverconventionalheating,includingreducedheat-ing time,uniform heating,reduced quality losses,absence of solute migration in food material,versatile,simple,and compact equipment,and significant energy saving.Infrared heating can be applied to various food processing opera-tions,namely,drying,baking,roasting,blanching,pasteurization,and binations of IR heating with microwave heating and other common conductive and convective modes of heating have been gaining momentum because of increased energy throughput.This article reviews aspects of IR heating and presents a theoretical basis for IR heat processing of food materials and the interaction of IR radiation with food components.The effect of IR on food quality attributes is discussed in the context of samples and process parameters.Applications of IR heatingin food processing operations and future research potential are also reviewed.IntroductionEnergy conservation is one of the key factors determining prof-itability and success of any unit operation.Heat transfer occurs through one of3methods,conduction,convection,and radia-tion.Foods and biological materials are heated primarily to ex-tend their shelf life or to enhance taste.In conventional heating, which is achieved by combustion of fuels or by an electric resis-tive heater,heat is generated outside of the object to be heated and is conveyed to the material by convection of hot air or by ther-mal conduction.By exposing an object to infrared(IR)radiation (wavelength of0.78to1000µm),the heat energy generated can be absorbed by food materials.Along with microwave,radiofre-quency(RF),and induction,IR radiation transfers thermal energy in the form of electromagnetic(EM)waves and encompasses that portion of the EM spectrum that borders on visible light and mi-crowaves(Figure1).Certain characteristics of IR heating such as efficiency,wavelength,and reflectivity set it apart from and make it more effective for some applications than others.IR heating is also gaining popularity because of its higher thermal efficiency and fast heating rate/response time in comparison to conven-tional heating.Recently,IR radiation has been widely applied to various thermal processing operations in the food industry such as dehydration,frying,and pasteurization(Sakai and Hanzawa 1994).MS20070368Submitted5/15/2007,Accepted8/5/2007.Author Krishna-murthy is with Dept.of Food and Animal Sciences,Alabama A&M Univ.,Nor-mal,AL35762,U.S.A.Authors Khurana and Jun are with Dept.of Human Nu-trition,Food and Animal Science,Univ.of Hawaii,Honolulu,HI96822,U.S.A. Author Irudayaraj is with Dept.of Agricultural and Biological Engineering,Pur-due Univ.,West Lafayette,IN47907,U.S.A.Author Demirci is with Agricultural and Biological Engineering,The Pennsylvania State Univ.,University Park,PA 16802,U.S.A.Direct inquiries to author Jun(E-mail:soojin@).Food systems are complex mixtures of different biochemical molecules,biological polymers,inorganic salts,and water.The infrared spectra of such mixtures originate with the mechanical vibrations of molecules or particular molecular aggregates within a very complex phenomenon of reciprocal overlapping(Halford 1957).Amino acids,polypeptides,and proteins reveal2strong absorption bands localized at3to4and6to9µm.On the other hand,lipids show strong absorption phenomena over the entire infrared radiation spectrum with3stronger absorption bands sit-uated at3to4,6,and9to10µm,whereas carbohydrates yield 2strong absorption bands centered at3and7to10µm(Sandu 1986;Rosenthal1992).IR radiation can be classified into3regions,namely,near-infrared(NIR),mid-infrared(MIR),and far-infrared(FIR),corre-sponding to the spectral ranges of0.75to1.4,1.4to3,and3 to1000µm,respectively(Sakai and Hanzawa1994).In general, FIR radiation is advantageous for food processing because most food components absorb radiative energy in the FIR region(Sandu 1986).Over the past several years,IR heating has been predominantly applied in the electronics and allied fields with little practical ap-plication in the food processing industry.However,in the last few years significant research efforts have been made in the area of IR heating of foods.The present review is in line with the cur-rent developments in the area of IR heating and a base for its widespread upcoming practical applications in food processing. Therefore,the aim of this review is to evaluate existing knowl-edge in the area of IR heating,provide insight for the relation be-tween product properties and engineering processes,and present an up-to-date view on further research.Along with the sound theoretical background on IR heating,the review also encom-passes application of IR heating in food processing operations such as drying,dehydration,blanching,thawing,pasteurization, sterilization,and other miscellaneous food applications such as2COMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY—Vol.7,2008C 2008Institute of Food TechnologistsInfrared heating in food processing...roasting,frying,broiling,and cooking,as well as in-depth assess-ment of pathogen inactivation.The effect of IR heating on sensory,physicochemical,nutritional,and microstructural quality of foods and its comparison with other existing common methods of heat-ing such as convection and microwave heating are discussed as well.Basic laws of infrared radiationThe amount of the IR radiation that is incident on any sur-face has a spectral dependence because energy coming out of an emitter is composed of different wavelengths and the fraction of the radiation in each band,dependent upon the temperature and emissivity of the emitter.The wavelength at which the maxi-mum radiation occurs is determined by the temperature of the IR heating elements.This relationship is described by the basic laws for blackbody radiation such as Planck ’s law,Wien ’s displace-ment law,and Stefan –Boltzman ’s law,as summarized in Table 1(Dagerskog and ¨Osterstr ¨om1979;Sakai and Hanzawa 1994).Interaction of IR radiation with food componentsThe effect of IR radiation on optical and physical propertiesof food materials is crucial for the design of an infrared heating system and optimization of a thermal process of food compo-nents.The infrared spectra of such mixtures originate with the mechanical vibrations of molecules or particular molecular ag-gregates within a very complex phenomenon in overlapping (Hal-ford 1957).When radiant electromagnetic energy impinges upon a food surface,it may induce changes in the electronic,vibrational,andVisible Table 1---Basic laws pertaining to infrared radiation.Basic laws Aspects addressed/explanationPlanck’s law Gives spectral blackbody emissive power distribution E b λ(T ,λ)E b λ(T ,λ)=2πhc 20n [e 0/n λkTWien’s displacement law Gives the peak wavelength (λmax ),where spectral distribution of radiation emitted by a blackbody reaches maximum emissive powerλmax =2898TStefan–Boltzmann’s law Gives the total power radiated (E b (T ))at a specific temperature from an infrared source E b (T )=n 2σT 4Modified Beer’s law Gives the transmitted spectral irradiance (H λW/m 2·µm)in nonhomogeneous systemsH λ=H λ0exp (−σ∗λu )ρ+α+τ=1Reflectivity (ρ):ratio of reflected part of incoming radiation to the total incoming radiation,absorptivity (α):ratio of absorbed part of incoming radiation to the total incoming radiation,and transmissivity (τ):ratio of transmitted part of incoming radiation to the total incoming radiation (Figure 2)k :Boltzmann’s constant (1.3806×10−23J/K),n :refractive index of the medium (n for vacuum is 1and,for most gases,n is very close to unity),λ:the wavelength (µm),T :sourcetemperature (K),c 0:speed of light (km/s),h :Planck’s constant (6.626×10−34J ·s),σ:Stefan–Boltzmann constant (5.670×10−8W m 2K4),λmax :peak wavelength,H λo :incident spectral irradiance (W/m 2·µm),u :mass of absorbing medium per unit area (kg/m 2)and σ∗λ:spectral extinction coefficient (m 2/kg).rotational states of atoms and molecules.As food is exposed to infrared radiation,it is absorbed,reflected,or scattered (a black-body does not reflect or scatter),as shown in Figure 2.Absorption intensities at different wavelengths differ by food components.The type of mechanisms for energy absorption determined by the wavelength range of the incident radiative energy can be cate-gorized as (1)changes in the electronic state corresponding to the wavelength range 0.2to 0.7µm (ultraviolet and visible rays),(2)changes in the vibrational state corresponding to wavelength range 2.5to 1000µm (FIR),and (3)changes in the rotational state corresponding to wavelengths above 1000µm (microwaves)(De-careau 1985).In general,the food substances absorb FIR energy most efficiently through the mechanism of changes in the molec-ular vibrational state,which can lead to radiative heating.Water and organic compounds such as proteins and starches,which are the main components of food,absorb FIR energy at wavelengths greater than 2.5µm (Sakai and Hanzawa 1994).Sandu (1986)reported that most foods have high transmissivities (low absorp-tivities)smaller than 2.5µm.Due to a lack of information,data on absorption of infrared radiation by the principal food constituents can be regarded as approximate values.The key absorption ranges of food compo-nents are as visualized in Figure 3(Sandu 1986).It depicts the principal absorption bands of the major food components com-pared to the absorption spectrum of water,indicating that the absorption spectra of food components overlap with one another in the spectral regions considered.Water effect on absorption of incident radiation is predominant over all the wavelengths,sug-gesting that selective heating based on distinct absorptivities forVol.7,2008—COMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY3CRFSFS:Comprehensive Reviews in Food Science and Food Safetya target food material can be more effective when predominant energy absorption of water is eliminated.The infrared absorption bands for chemical groups and relevant food components are summarized in Table 2(Rosenthal 1992).Interactions of light with food material and the crucial optical principles such as regular reflection,body reflection,and light scattering were discussed by Birth (1978).Regular reflection takes place at the surface of a material.For body reflection,the light enters the material,becomes diffuse due to light scattering,and undergoes some absorption;and the remaining light leaves the material close to where it enters.Regular reflection produces only the gloss or shine of polished surfaces,whereas body reflection produces the colors and patterns that constitute most of the in-formation obtained visually.For materials with a rough surface,both regular and body reflection can be observed.For instance,at NIR wavelength region (λ<1.25µm),approximately 50%of the radiation is reflected back,while less than 10%radiation is reflected back at the FIR wavelength region (Skjoldebrand 2001).Most organic materials reflect 4%of the total reflection produc-ing a shine of polished surfaces.The rest of the reflection occurs where radiation enters the food material and scatters,producing different color and patterns (Dagerskog 1979).The infrared optical characteristics of different media are also theoretically discussed demonstrating the necessity of the scat-tered radiation during measurements (Krust and others 1962).It was experimentally observed that as the thickness of the layer increases,a simultaneous decrease in transmittance and increase in reflection occurs.However,no theoretical explanation of thission,and reflection).Figure 3---Principal absorption bands of the main food components compared with water (Sandu 1986).phenomenon was presented.Applications of IR heating in food processing operationsThe application of infrared radiation to food processing has gained momentum due to its inherent advantages over the con-ventional heating systems.Infrared heating has been applied in drying,baking,roasting,blanching,pasteurization,and steriliza-tion of food products.Drying and dehydration.Infrared heating provides an imper-ative place in drying technology and extensive research work has been conducted in this area.Most dried vegetable products are prepared conventionally using a hot-air dryer.However,this method is inappropriate when dried vegetables are used as in-gredients of instant foods because of low rehydration rate of the vegetables.Freeze-drying technique is a competitive alternative;however,it is comparatively expensive.Application of FIR drying in the food industry is expected to represent a new process for the production of high-quality dried foods at low cost (Sakai and Hanzawa 1994).The use of IR radia-tion technology for dehydrating foods has numerous advantages including reduction in drying time,alternate energy source,in-creased energy efficiency,uniform temperature in the product while drying,better-quality finished products,a reduced neces-sity for air flow across the product,high degree of process control parameters,and space saving along with clean working environ-ment (Dostie and others 1989;Navari and others 1992;Sakai and Hanzawa 1994;Mongpreneet and others 2002).Therefore,FIR drying operations have been successfully ap-plied in recent years for drying of fruit and vegetable products such as potatoes (Masamura and others 1988;Afzal and Abe 1998),sweetpotatoes (Sawai and others 2004),onions (Mongpre-neet and others 2002;Sharma and others 2005),kiwifruit (Fenton and Kennedy 1998),and apples (Nowak and Levicki 2004;Togrul 2005).Drying of seaweed,vegetables,fish flakes,and pasta is also done in tunnel infrared dryers.Infrared drying has found its appli-cation in food analysis to measure water content in food products(Hagen and Drawert 1986;Anonymous 1995).Generally,solid materials absorb infrared radiation in a thin surface layer.However,moist porous materials are penetrated by radiation to some depth and their transmissivity depends on the moisture content (Lampinen and others 1991).Energy and mass balance developed by Ratti and Mujumdar (1995)accounts for the shrinkage of the heated particle and absorption of infraredenergy.Theoretical calculations showed that intermittent infrareddrying with energy input of 10W/m 2becomes equivalent to con-vective drying in which the heat transfer coefficient would be as high as 200W/m 2K.Factors affecting IR drying kinetics have been studied by several researchers.Masamura and others (1988)confirmed increasedTable 2---The infrared absorption bands for chemical groups and relevant food components (Rosenthal 1992).Absorption Relevant wavelengthfood Chemical group(µm)component Hydroxyl group (O-H)2.7to3.3Water,sugars Aliphatic carbon-hydrogen bond 3.25to 3.7Lipids,sugars,proteins Carbonyl group (C =O)(ester) 5.71to 5.76Lipids Carbonyl group (C =O)(amide) 5.92Proteins Nitrogen –hydrogen group (-NH-) 2.83to 3.33Proteins Carbon –carbon double 4.44to 4.76Unsaturated bond (C =C)lipids4COMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY—Vol.7,2008Infrared heating in food processing...drying rates of potatoes with increasing surface temperature of the radiator.Optimization of the FIR heating process for shrimp dehydration found that the effect of plate distance on the drying rate was not significant,whereas the drying rate increased mono-tonically with an increase in the plate and air temperature(Fu and Lien1998).Nowak and Levicki(2004)reported that infrared drying of apple slices was an effective and much faster method of water removal than convective drying under equivalent parame-ters.Exploring the IR convective drying of onion slices,Sharma and others(2005)observed that the drying time increased with the increase in air velocity at all infrared powers applied;how-ever,it reduced with an increase in infrared power and the drying took place in the falling drying rate period.Integrated drying technologies:IR and convective drying.Even though IR drying is a promising novel method,it is not a panacea for all drying processes.It appeals,because it is fast and pro-duces heating inside the material being dried,but its penetrating powers are limited(Hashimoto and others1990;Sakai and oth-ers1993).Prolonged exposure of a biological material to IR heat results in swelling and ultimately fracturing of the material(Jones 1992).Fasina and others(1996)showed that IR heating changes the physical,mechanical,chemical,and functional properties of barley grains.IR heating of legume seeds to140◦C caused crack-ing on the surface(Fasina and others1997).However,a combi-nation of intermittent infrared heating and continuous convection drying of thick porous material resulted in better product quality and energy efficiency(Dostie and others1989).Thus,IR radiation can be considered as surface treatment similar to other radiation technologies.Application of combined electromagnetic radiation and con-ventional convective heating is considered to be more efficient over radiation or convective heating alone,as it gives a syn-ergistic effect.Afzal and others(1999)reported that during the combined convective and IR heating process of barley,the total energy required was reduced by about156%,238%,and245% as compared with convection drying alone at40,55,or70◦C, respectively.Datta and Ni(2002)discussed the application of combined infrared,microwave,and hot air heating food mate-rials.Mongpreneet and others(2002)evaluated the dehydrating synergy generated when using ceramic-coated radiators and a high-vacuum environment to study drying of welsh onion. Development of a continuous drying apparatus equipped with FIR heaters,NIR heaters,and hot air blast can reduce the eco-nomic costs,drying time,and operating temperature.However, vegetable size should be restricted to no more than5mm in thick-ness to improve drying efficiency(Sakai and Hanzawa1994). Hebbar and others(2004)developed a continuous combined in-frared and convective dryer for vegetables.The synergistic effect of infrared and hot air led to rapid heating of the materials,re-sulting in a higher rate of mass transfer.The evaporation of water took48%less time and63%less energy consumption in com-bined mode drying as compared to convective drying. Recently,the concept of FIR heating immediately after convec-tive drying(approximately40◦C)for drying of paddy has been utilized in the paddy industry in Japan(Bekki1991;Inst.of Agri-cultural Machinery2003).Gabel and others(2006)compared the drying and quality characteristics of sliced high-solids onions dried with catalytic infrared(CIR)heating and forced air convec-tion(FAC)heating.CIR both with and without air recirculation had higher maximum drying rates,shorter drying times,and greater drying constants than FAC at moisture contents greater than50% (d.b.).A combination of IR heating with freeze-drying in sweetpota-toes could reduce the processing time by less than half(Lin and others2005).The effect of NIR on reduction of freeze-drying time of beef was investigated by Burgheimer and others(1971).The authors concluded that shorter wavelength resulted in rapid drying and thus reduced drying time.Drying time with infrared heating was reduced to7h,as opposed to11h with convectional drying.Enzyme inactivation.Infrared heating can be effectively used for enzyme inactivation.Lipooxygenase,an enzyme responsible for deterioration in soybeans,was inactivated95.5%within60s of IR treatment(Kouzeh and others1982).Certain enzyme reac-tions(involving action of lipases andαamylases)were affected by infrared radiation at a bulk temperature of30to40◦C(Ko-hashi and others1993;Rosenthal and others1996;Sawai and others2003).FIR radiation for6min resulted in a60%reduc-tion in lipase activity,while thermal conduction resulted in70% reduction.FIR has been successfully used to inactivate enzymes responsi-ble for the development of off-flavors in peas prior to the freezing process(van Zuilichem and others1986),as well as other en-zymes and bacteria in solution(Sawai and others2003).Galindo and others(2005)investigated the application of IR heating of carrot slices prior to freezing as compared to blanching in terms of carrot cell and tissue damage.Carrot slices heated by FIR ra-diation contained damaged cells only in the first half millimeter from the surface and exhibited the texture characteristic of the raw tissue,thus providing the potential of FIR energy technology in the frozen carrots industry.Pathogen inactivation.IR heating can be used to inactivate bac-teria,spores,yeast,and mold in both liquid and solid foods.Ef-ficacy of microbial inactivation by infrared heating depends on the following parameters:infrared power level,temperature of food sample,peak wavelength,and bandwidth of infrared heating source,sample depth,types of microorganisms,moisture content, physiological phase of M/Os(exponential or stationary phase), and types of food materials.Therefore,several researchers have investigated the effects of these parameters on inactivation of pathogenic microorganisms as follows.Effect of power:Increase in the power of infrared heating source produces more energy and thus total energy absorbed by microor-ganisms(M/Os)increases,leading to microbial inactivation.Ster-ilization of wheat surface was investigated by Hamanaka and others(2000).Surface temperature increased rapidly as infrared rays directly heated the surface without any need for conductors. Therefore,irradiating powers of0.5,1.0,1.5,and2.0kW resulted in60,80,125,and195◦C inside the experimental device,and 45,65,95,and120◦C on the surface of wheat stack,obtaining 0.83,1.14,1.18,and1.90log10CFU/g total bacteria after a60s treatment,respectively.Temperature of food sample:Dry heat inactivation of B.sub-tilis spores by infrared radiation was investigated by Molin and Ostlund(1975).D values of B.subtilis at120,140,160,and 180◦C were26min,66,9.3,and3.2s,respectively.Shorter treatment time was enough to inactivate pathogens at higher tem-peratures and the estimated Z value was23◦C.E.coli population was reduced by0.76,0.90,and0.98log10after2min exposure to IR radiation when the temperature of the bacterial suspension was maintained at56,58,and61◦C,correspondingly(Sawai and others2003).Effect of peak wavelength and bandwidth:As indicated earlier, food and microbial components absorb certain wavelengths of infrared radiation.Therefore,it is beneficial to investigate the ab-sorption pattern of key components in order to ensure pathogen inactivation and minimize changes in food quality.It would be feasible to selectively heat the M/Os present in food products without adversely increasing the temperature of sensitive food components.Jun and Irudayaraj(2003)utilized selective infrared heating in the wavelength range of5.88to6.66µm using optical bandpass filters for inactivation of Aspergillus niger and Fusar-Vol.7,2008—COMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY5CRFSFS:Comprehensive Reviews in Food Science and Food Safetyium proliferatum in corn meal.The selected wavelength dena-tures the protein in microorganisms,leading to a40%increase in inactivation of A.niger and F.proliferatum compared to normal IR heating.For instance,a5-min treatment with nonselective and se-lective heating resulted in approximately1.8and2.3log10CFU/g reduction of A.niger.Similarly,reductions of1.4and1.95log10 CFU/g of F.proliferatum were obtained with5min of nonselective and selective heating,respectively.Although the sample temper-atures after selective or nonselective infrared heating were iden-tical,absorption of energy by fungal spores increased in selective heating,leading to a higher lethal rate(Jun and Irudayaraj2003). Total energy decreases as the peak wavelength increases. Therefore,NIR radiation with short wavelength has a relatively higher energy level than FIR radiation with longer wavelength. Hamanaka and others(2006)studied the inactivation efficacy of Bacillus subtilis treated with3infrared heaters(A,B,and C) having different peak wavelengths(950,1100,and1150nm)and radiant energies(4.2,3.7,and3.2µW/cm2/nm),respectively.Air-dried Bacillus subtilis solution placed on a stainless steel petri dish was treated with infrared heating after water activity adjustment using a desiccator.Surface temperature of petri dish was100◦C after a2-min exposure for all the heaters.Pathogen inactivation was higher with heater A than those of heaters B and C,although temperature was the same for all the heaters.For example,at wa-ter activity of0.7,decimal reduction times of heaters A,B,and C were approximately4,12,and22min,respectively.Therefore, it is obvious that inactivation efficiency is associated with the radiation spectrum(Hamanaka and others2006).Effect of sample depth:The penetration depth of IR radiation is very low.An increase in the sample depth slows down the bulk temperature increase of the food sample(Sawai and others1995). A90%reduction in IR power was observed within a thin layer of40µm in bacterial suspension(Hashimoto and others1991). Therefore,the effect of IR radiation on the microbial inactiva-tion diminishes as the sample thickness increases.Decreasing the sample depth also accelerates the inactivation of spores(Sawai and others1997)and E.coli and S.aureus(Hashimoto and others 1992a).The ratio of number of injured cells to the number of sur-vivors increased as the depth decreased.For example,S.aureus population was reduced by approximately2and5log10CFU/mL at321◦K,when the sample depths were2.9and0.9mm,re-spectively.Similarly,E.coli population in the samples with1.3 and2.2mm in depth showed approximately1.33and1.66log10 CFU/mL at321◦K.Types of M/Os:Resistance of bacteria,yeasts,and molds to infrared heating may be different due to their structural and com-positional differences.In general,spores are more resistant than vegetative cells.When Bacillus subtilis spores in physiological saline were exposed to infrared heating,a spore population in-creased up to5times in the first2min,followed by subsequent exponential reduction,resulting in shoulder and tailing effects. Upon infrared heat treatment,vegetative cells were inactivated followed by activation of spores.Then vegetative cells formed from spores will be activated and thus spores will be inactivated. If inactivation occurs in sequence,there will be tailing and shoul-der effects.An initial increase in B.subtilis population was caused by heat shock germination of spores.A10-min treatment with infrared heating resulted in more than90%reduction in B.sub-tilis population(Daisuke and others2001).Hamanaka and oth-ers(2006)also reported a shoulder effect where B.subtilis spores were germinated.Cereal surface is often contaminated with spore formers like Bacillus,Aspergillus,and Penicillium.Wheat was treated with in-frared heating at2.0kW for30s,followed by cooling for4h,and again treated for30s with infrared heating to obtain a1.56log10 CFU/g reduction.The irradiation helped in activation of spores into vegetative cells and the second irradiation effectively inacti-vated spore formers.Furthermore,intermittent treatment can min-imize the quality changes,as continuous treatment longer than 50s resulted in discoloration of wheat surface(Hamanaka and others2000).Naturally occurring yeasts in honey were completely inacti-vated with an8-min infrared heat treatment(Hebbar and others 2003).The temperature of the honey was raised to110◦C af-ter the treatment,resulting in microbial reduction of3.85log10 CFU/mL.Effect of moisture content:Water molecules inside M/Os read-ily absorb infrared radiation.These water molecules are attached to polar groups such as-NH2,-COOH,and-COO within the cell (Uedaira and Ohsaka1990;Hamanaka and others2006).State and amount of water inside spores,bonding conditions of water molecules,and location of water molecule within M/Os affect their responses to infrared heating(Hamanaka and others2006). Maximum D values of B.subtilis spores inactivated by IR heat differed with initial water activities ranging from0.6to0.9.As the peak wavelength of the IR heating was short,the initial val-ues of water activity leading to maximum D values for bacterial spores also increased.Physiological phase of M/Os:Physiological phase of M/Os can be classified as lag phase(M/Os adapt to new environment before replicating),exponential phase(the number of M/Os increases exponentially),stationary phase(no further increase in M/O pop-ulation),and death phase(the number of dead cells is higher than live cells).The chemical composition and resistance of the M/Os in various growth phases are different.Exponential phase cells are more sensitive to IR heating than stationary phase cells. In other words,exponential phase cells will have more injuries than stationary phase cells under IR heating.Sawai and others (1997)reported that IR radiation at3.2kW/m2resulted in reduc-tions of approximately1.8and3.9log10CFU/mL for stationary and exponential phase cells after5-min treatment,respectively. It was also found that the pasteurization effect of FIR irradiation was much higher than conductive heating on exponential phase cells under the same conditions.Inactivation mechanism:Inactivation of M/Os by IR heating may include inactivation mechanism similar to that of ultra-violet light(DNA damage)and microwave heating(induction heating)in addition to thermal effect,as infrared is located be-tween ultraviolet and microwave in the electromagnetic spectrum (Hamanaka and others2000).Thermal inactivation can damage DNA,RNA,ribosome,cell envelope,and proteins in microbial cell.Sawai and others(1995)investigated the inactivation mech-anism of E.coli treated with infrared radiation in phosphate buffer saline.They proposed that sublethally injured cells will become more sensitive to an inhibitory agent which has an inhibitory ac-tion on the damaged portion of the cell.Four inhibitory agents, namely,penicillin(PCG;inhibits cell wall synthesis),chloram-phenicol(CP;inhibits protein synthesis),rifampicin(RFP;inhibits RNA synthesis),and nalidixic acid(NA;inhibits DNA synthe-sis),were used for the enumeration of pathogens.An8-min in-frared radiation at a wattage of3.22kW/m2resulted in approx-imately1.8,1.9,2.7,and3.2log10reduction of E.coli,when NA,PCG,RFP,and CP enriched agars were used for enumer-ation,respectively.When no inhibitory agents were present,a 1.8log reduction was obtained.This observation implies that approximately0.1,0.9,and1.4log reductions were caused by inhibitory actions of PCG,RFP,and CP,respectively.With con-ductive heating,similar damages were observed;however,RNA, protein,and cell wall showed more vulnerability to IR heating than conductive heating.The order of magnitude of infrared dam-ages was as follows:protein>RNA>cell wall>DNA.RFP inhibits RNA polymerase in E.coli and CP binds ribosomal sub-6COMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY—Vol.7,2008。