eBooks de Estudios y ensayos, página 6 de 16

Soluciones a los problemas planteados en el tomo I de la obra Ingeniería Química. Soluciones a los problemas planteados en el tomo I de la obra Ingeniería Química.

Es deplorable que la resolución de problemas no siempre reciba suficiente atención. En la mayoría de los manuales de Química, para la preparación del ingreso en los Centros de Enseñanza Superior, los problemas son considerados como una cuestion secundaria. Este manual presenta por separado y en la mayor parte de los casos con sus resoluciones, diferentes tipos de problemas y de metodos para su resolucion.

Oliver Sacks evoca en este libro de memorias su niñez en Inglaterra. Cuando tenía seis años estalla la Segunda Guerra Mundial y es enviado, junto con su hermano Michael, a un internado en el campo. Cuatro años despues, a su regreso a Londres, Michael enloquece, y Oliver encuentra su salvacion personal en el mundo de la ciencia. Quien lo inicia es su tio Dave, el tio Tungsteno, dueño de una fabrica de bombillas electricas. Y asi, totalmente absorto en la fisica y la quimica, el adolescente va construyendose un peculiar paraiso intelectual, donde sus heroes son Lavoisier, Marie Curie, Mendeleev y su tabla de los elementos...

Este manual trata todos los aspectos de la química organometálica en su sentido más amplio: histórico, conceptos fundamentales, estructuras, orbitales moleculares, reactividad, catálisis, biología, aplicaciones en sintesis organica, y en particular, los grandes procesos industriales y las sintesis de medicamentos y productos naturales. Todos los metales estan considerados: los metales de transicion, los metales de los grupos principales y los lantanidos y actinidos.El texto aqui presentado esta destinado a servir de apoyo en los cursos de quimica organometalica que se imparten en el segundo ciclo de la licenciatura en ciencias quimicas. Asi pues, corresponde sobre todo a un primer nivel.

El objetivo de esta antología es mostrar qué es la química, qué investigan quienes se dedican a ella, cómo se hace y qué procesos involucra, alentando la capacidad de asombro y la curiosidad en nuestros lectores, jovenes y profesores de bachillerato. Ofrecemos aqui una seleccion enriquecida de lecturas que contribuiran a la formacion de los alumnos que cursan la materia de quimica. A las sustancias y materiales, teoria e historia de la quimica, su influencia en el medio ambiente y los avances de la bioquimica temas de nuestra primera edicion, se añaden ahora semblanzas de reconocidos quimicos como Lavoisier, Mendeleiev y Pasteur, asi como temas tan relevantes como el descubrimiento del ADN, el papel de las moleculas y las hormonas en la obesidad, las endorfinas, los enemigos de las vacunas y las drogas sinteticas, entre otros. Ademas, entrevistas con quimicos universitarios como Plinio Sosa, Ana Maria Martinez Vazquez y Agustin Lopez Munguia.

Este libro incluye treinta experimentos de aula que cubren algunos de los temas de Química General y Termodinámica que se tratan en los cursos de nivel medio superior y superior. Están agrupados de acuerdo con una tematica especifica: caracteristicas y propiedades de la materia, cambio quimico y tipos de reacciones quimicas. El profesor puede darle el nivel de profundidad que requiera de acuerdo a la planeacion de su clase, las caracteristicas del grupo y el nivel educativo del que se trate.

La química entre nosotros es una selección integrada por once artículos de divulgación preparados por dieciséis investigadores y estudiantes en activo de la Facultad y el Instituto. Desde la enseñanza, la investigacion y la divulgacion, las tres instancias universitarias participamos en este esfuerzo editorial con el objetivo de contribuir a la apreciacion y el entendimiento de la quimica en tanto conocimiento imprescindible para la vida y la cultura del siglo XXI. El interes de los autores por dar vida a esta antologia se explica por la necesidad de dar a conocer de una manera sencilla pero rigurosa los conocimientos generados en sus estudios de frontera, lo cual sin duda ampliara el contacto de los lectores con las ciencias quimicas. Es por medio de la divulgacion como se pueden aportar conocimientos fundamentales sobre las diversas areas de la quimica y su relacion con otras disciplinas cientificas, para acercar asi a la sociedad a los complejos desarrollos del mundo academico, con miras a obtener un mejor entendimiento de las relaciones entre ciencia y vida cotidiana.

Polytetrafluoroethylene (PTFE) is an engineered paradox. Better known as Teflon, it is the slipperiest solid material known to science, capable of shedding water, grease, and extreme heat without breaking a sweat. It revolutionized aerospace engineering and cookware by completely refusing to interact with its physical environment, but this exact chemical defiance is now recognized as a global biological hazard.The core of PTFE is the carbon-fluorine bond, which is so incredibly strong that it cannot be broken down by natural geological or biological processes. As these "forever chemicals" (PFAS) are shed from frying pans and industrial coatings, they accumulate permanently in the soil, the water table, and human bloodstreams. The industry is currently facing a reckoning, struggling to find alternative low-friction materials that dont leave a permanent, toxic legacy in the biosphere.Analyze the molecular architecture of frictionless surfaces. Understand the severe biological trade-offs of engineering synthetic polymers designed to outlast the natural world.

When Claude Monet and Vincent van Gogh painted their sun-drenched wheat fields and glowing sunflowers, they relied on a newly discovered chemical element. Cadmium offered a level of vibrancy and opacity that older organic yellows simply could not match, allowing the Impressionists to capture light with unprecedented intensity. However, the tubes of paint they handled daily contained a highly dangerous heavy metal.Cadmium is a cumulative toxin and a known carcinogen that aggressively targets human lung and kidney tissue. For over a century, painters sculpted their masterpieces while breathing in toxic dust and inadvertently absorbing the metal through their skin. Today, strict environmental and health regulations are forcing major paint manufacturers to phase out authentic cadmium pigments entirely, creating a deep divide between traditional artists demanding aesthetic purity and safety advocates demanding chemical bans.Trace the intersection of fine art and heavy metal toxicity. Discover how the pursuit of the perfect color exposed generations of visionary artists to severe, invisible neurological decay.

The birth of the motion picture industry relied on a medium that was chemically engineered to self-destruct. Early cinematic film was printed on cellulose nitrate, a highly volatile cousin of guncotton. This unstable compound produced exceptionally sharp, silver-rich images, but it also possessed a terrifying propensity for spontaneous combustion. Once ignited, a nitrate fire generates its own oxygen, meaning it can burn fiercely even underwater.Because of this chemical hazard, over half of all films made before 1950 have been permanently erased from history. Entire archives burned to the ground in sudden infernos, while the reels that survived the flames fell victim to a slower molecular decay, turning into acidic dust or sticky goo in their canisters. Today, archivists face a ticking clock, utilizing sub-zero cold storage and desperate digitization efforts to rescue the remaining fragments of our visual heritage.Watch the flickering, explosive origins of the silver screen. Grasp the devastating chemical trade-offs early filmmakers accepted to capture motion, and the frantic race to save their rotting legacy.

The bread you buy at the supermarket today bears almost no physical resemblance to the bread consumed just a century ago. In 1961, a quiet laboratory experiment fundamentally altered global diets forever. It completely bypassed the ancient, slow process of natural fermentation in favor of aggressive mechanical force and complex chemical additives.The goal was extreme efficiency. Traditional baking required hours of resting and specific, high-protein wheat. The Chorleywood Bread Process utilized intense mechanical mixing, solid vegetable fats, and ascorbic acid to force lower-quality flour into a rapid rise. This allowed factories to pump out millions of ultra-soft, highly preserved loaves at a fraction of the cost, but stripped away the natural digestibility of the grain.This book breaks down the biochemical reality of modern industrial baking. You will explore the exact synthetic enzymes used to maintain artificial freshness, the physical engineering of the high-speed mixers, and the subsequent explosion of modern gluten sensitivities.Step onto the factory floor of the global food supply. Discover the scientific manipulation behind the modern loaf and rethink the basic chemistry of your everyday diet.

Edição revista e atualizada de Introdução a métodos cromatográficos, este livro apresenta princípios básicos de cromatografia, descreve as diferentes técnicas cromatográficas e reúne sugestões para e

A química brasileira atual desperta grande interesse por suas origens. A maioria dos relatos prende-se ao século XX, havendo pouca publicação sobre períodos anteriores. Na colônia praticavam-se técni

Triste? Apaixonado? Entediado? A Química explica-lhe o porquê. Acredita que é um ser racional? Que as suas decisões são fruto de uma lógica apurada e de uma vontade soberana? A verdade é muito mais

A ciência, em sua mais nobre vocação, é um ato de serviço. Na Engenharia de Alimentos, essa verdade se manifesta com especial clareza: o saber técnico-laboratorial se torna a ponte entre o invisível

When we bite into a potato chip, we believe we are evaluating its quality based on taste and texture. However, the food industry knows that the most critical metric for perceived freshness is hidden in the auditory cortex. The sensation of crunchiness is not just a physical force; it is a meticulously engineered acoustic event designed to trigger a primal neurological reward.Food scientists utilize specialized microphones and pressure sensors to calibrate the exact decibel level and frequency pitch of a breaking chip. If the snap is too quiet or the frequency too low, the brain immediately registers the food as stale and unappetizing, regardless of its actual chemical composition. By optimizing the sonic amplitude of our food, corporations hijack our evolutionary association between loud, crisp sounds and nutrient-dense, fresh vegetables."Acoustic Appetites" uncovers the bizarre intersection of psychoacoustics and culinary chemistry. It reveals how multi-national snack conglomerates manipulate the physics of sound to maximize cravings, bypass our satiety mechanisms, and enforce habitual consumption.Listen closely to the hidden engineering on your plate. Recognize the auditory manipulation governing your dietary choices, and reclaim your autonomy from the highly calculated sonic architecture of modern junk food.

Take a look in your refrigerator, your bathroom cabinet, and your medicine pouch. From the smooth texture of your ice cream and the foam on your beer to your toothpaste and the petri dishes used in critical medical research, one invisible ingredient holds it all together: seaweed extracts. Agar, carrageenan, and alginate are the unsung heroes of global manufacturing, forming a multi-billion-dollar industry harvested entirely from the ocean.This fascinating exploration dives into the complex supply chains and food chemistry of hydrocolloids. You will discover how a simple red algae cultivated by impoverished farmers in Southeast Asia is processed into high-tech gels that stabilize the entire modern food and pharmaceutical system. The book uncovers the historical accidents that led to seaweeds industrial dominance and the fierce corporate battles over extraction patents.Learn how this hidden oceanic commodity dictates the texture of our daily lives. As climate change threatens fragile coastal ecosystems, understanding the economics of seaweed is crucial to securing the invisible glue that keeps our modern world from literally falling apart.

For decades, consumers have scoured food labels looking for the dreaded letters "MSG," convinced that Monosodium Glutamate is a toxic chemical responsible for headaches, sweating, and heart palpitations. Restaurants proudly advertise "No MSG" to ease public anxiety. Yet, scientifically, MSG is simply sodium combined with glutamate, an amino acid naturally found in massive quantities in tomatoes, parmesan cheese, and human breast milk.So how did one of the greatest culinary discoveries of the 20th century become universally demonized? The origin of the MSG panic traces back to a single, anecdotal letter submitted to a medical journal in 1968, which casually coined the term "Chinese Restaurant Syndrome." What followed was a masterclass in mass hysteria, fueled not by clinical data, but by deeply ingrained xenophobia and a western distrust of Asian immigration.This fascinating exploration of food chemistry and cultural history completely dismantles the panic. It explores the Japanese laboratory where MSG was first synthesized to isolate the elusive fifth tasteumamiand traces its quiet adoption by massive American food corporations who hid it in snacks while publicly condemning its use in Asian cuisine.Prepare to rethink everything you know about flavor. Uncover the truth behind the scapegoat, shed the baseless fear of this crystalline seasoning, and learn how to embrace the pure, savory magic of umami in your own kitchen.

A quitosana e dois derivados modificados (com pirocatecol e óleo de girassol) foram empregados como adsorventes para seis diferentes corantes têxteis. Os ensaios foram realizados em soluções aquosas,

Esta edição reúne conteúdos essenciais de Ciências da Natureza, com foco em Química, Termologia e Óptica. Na parte de Química, apresenta matéria, substância e estados físicos. Em Termologia, explora