Gør som tusindvis af andre bogelskere
Tilmeld dig nyhedsbrevet og få gode tilbud og inspiration til din næste læsning.
Ved tilmelding accepterer du vores persondatapolitik.Du kan altid afmelde dig igen.
Metal¿organic frameworks (MOFs) are a class of compounds consisting of metal ions or clusters coordinated to organic ligands to form one-, two-, or three-dimensional structures. They are a subclass of coordination polymers, with the special feature that they are often porous. The organic ligands included are sometimes referred to as "struts" or "linkers", one example being 1,4-benzenedicarboxylic acid (BDC).More formally, a metal¿organic framework is a coordination network with organic ligands containing potential voids. A coordination network is a coordination compound extending, through repeating coordination entities, in one dimension, but with cross-links between two or more individual chains, loops, or spiro-links, or a coordination compound extending through repeating coordination entities in two or three dimensions; and finally a coordination polymer is a coordination compound with repeating coordination entities extending in one, two, or three dimensions. In some cases, the pores are stable during elimination of the guest molecules (often solvents) and could be refilled with other compounds. Ladies and gentlemen!Welcome to the realm of MOF!
Where did chemistry come from? Early "chemists" focused on practical problems -how to make dyes and perfumes, soap manufacture, uses of metals, and glass production, among others. The goal was not to understand the physical world- that came later. People just wanted to make things that would improve their lives in some way.The history of chemistry is an interesting and challenging one. Very early chemists were often motivated mainly by the achievement of a specific goal or product. Making perfume and soaps did not require much theory, just a good recipe and careful attention to detail. There was no standard way of naming materials (and no periodic table that everyone could agree on). However, the science developed over the centuries.Major progress was made in putting chemistry on a solid foundation when Robert Boyle (1637-1691) began his research in chemistry. He developed the basic ideas for the behavior of gases; gases could thereafter be described mathematically. Boyle also helped pioneer the idea that small particles could combine to form molecules. Many years later, John Dalton used these ideas to develop the atomic theory.
Atomic physics is the field of physics that studies atoms as an isolated system of electrons and an atomic nucleus. Atomic physics typically refers to the study of atomic structure and the interaction between atoms.[1] It is primarily concerned with the way in which electrons are arranged around the nucleus and the processes by which these arrangements change. This comprises ions, neutral atoms and, unless otherwise stated, it can be assumed that the term atom includes ions.The term atomic physics can be associated with nuclear power and nuclear weapons, due to the synonymous use of atomic and nuclear in Standard English. Physicists distinguish between atomic physics -which deals with the atom as a system consisting of a nucleus and electrons- and nuclear physics, which studies nuclear reactions and special properties of atomic nuclei.As with many scientific fields, strict delineation can be highly contrived and atomic physics is often considered in the wider context of atomic, molecular, and optical physics.
Zeolites are microporous, aluminosilicate minerals commonly used as commercial adsorbents and catalysts. The term zeolite was originally coined in 1756 by Swedish mineralogist Axel Fredrik Cronstedt, who observed that rapidly heating a material, believed to have been stilbite, produced large amounts of steam from water that had been adsorbed by the material. Based on this, he called the material zeolite, from the Greek ¿¿¿ (zé¿), meaning "to boil" and ¿¿¿¿¿ (líthos), meaning "stone". The classic reference for the field has been Breck's book Zeolite Molecular Sieves: Structure, Chemistry, and Use.Zeolites occur naturally but are also produced industrially on a large scale. As of December 2018, 253 unique zeolite frameworks have been identified, and over 40 naturally occurring zeolite frameworks are known. Every new zeolite structure that is obtained is examined by the International Zeolite Association Structure Commission and receives a three letter designation.Zeolites have a porous structure that can accommodate a wide variety of cations, such as Na+, K+, Ca2+, Mg2+ and others. Ladies and Gentlemen!Welcome to the realm of hard frames empire!
Carbon (C), nonmetallic chemical element in Group 14 (IVa) of the periodic table. Although widely distributed in nature, carbon is not particularly plentiful -it makes up only about 0.025 percent of Earth¿s crust- yet it forms more compounds than all the other elements combined. In 1961 the isotope carbon-12 was selected to replace oxygen as the standard relative to which the atomic weights of all the other elements are measured. Carbon-14, which is radioactive, is the isotope used in radiocarbon dating and radiolabeling.On a weight basis, carbon is 19th in order of elemental abundance in Earth¿s crust, and there are estimated to be 3.5 times as many carbon atoms as silicon atoms in the universe. Only hydrogen, helium, oxygen, neon, and nitrogen are atomically more abundant in the cosmos than carbon. Carbon is the cosmic product of the ¿burning¿ of helium, in which three helium nuclei, atomic weight 4, fuse to produce a carbon nucleus, atomic weight 12.In the crust of Earth, elemental carbon is a minor component. However, carbon compounds (i.e., carbonates of magnesium and calcium) form common minerals (e.g., magnesite, dolomite, marble, or limestone).
A coordination complex consists of a central atom or ion, which is usually metallic and is called the coordination center, and a surrounding array of bound molecules or ions, that are in turn known as ligands or complexing agents. Many metal-containing compounds, especially those that include transition metals (elements like titanium that belong to the Periodic Table's d-block), are coordination complexes.Coordination chemistry emerged from the work of Alfred Werner, a Swiss chemist who examined different compounds composed of cobalt (III) chloride and ammonia. Upon the addition of hydrochloric acid, Werner observed that ammonia could not be completely removed. He then proposed that the ammonia must be bound more tightly to the central cobalt ion. However, when aqueous silver nitrate was added, one of the products formed was solid silver chloride. The amount of silver chloride formed was related to the number of ammonia molecules bound to the cobalt (III) chloride. For example, when silver nitrate was added to CoCl3¿6NH3, all three chlorides were converted to silver chloride. However, when silver nitrate was added to CoCl3¿5NH3, only 2 of the 3 chlorides formed silver chloride.
Toxicology is a scientific discipline, overlapping with biology, chemistry, pharmacology, and medicine that involves the study of the adverse effects of chemical substances on living organisms and the practice of diagnosing and treating exposures to toxins and toxicants. The relationship between dose and its effects on the exposed organism is of high significance in toxicology. Factors that influence chemical toxicity include the dosage, duration of exposure (whether it is acute or chronic), route of exposure, species, age, sex, and environment. Toxicologists are experts on poisons and poisoning. There is a movement for evidence-based toxicology as part of the larger movement towards evidence-based practices. Toxicology is currently contributing to the field of cancer research, since some toxins can be used as drugs for killing tumor cells. One prime example of this is ribosome-inactivating proteins, tested in the treatment of leukemia.
Green chemistry, also called sustainable chemistry, is an area of chemistry and chemical engineering focused on the design of products and processes that minimize or eliminate the use and generation of hazardous substances. While environmental chemistry focuses on the effects of polluting chemicals on nature, green chemistry focuses on the environmental impact of chemistry, including lowering consumption of nonrenewable resources and technological approaches for preventing pollution. The overarching goals of green chemistry¿namely, more resource-efficient and inherently safer design of molecules, materials, products, and processes¿can be pursued in a wide range of contexts.The concept of greening chemistry developed in the business and regulatory communities as a natural evolution of pollution prevention initiatives. In our efforts to improve crop protection, commercial products and medicines, we also caused unintended harm to our planet and humans. By the mid-20th century, some of the long-term negative effects of these advancements could not be ignored. Pollution choked many of the world's waterways and acid rain deteriorated forest health.
Petroleum, also known as crude oil and oil, is a naturally occurring, yellowish-black liquid found in geological formations. It is commonly refined into various fuels and chemicals. Components of petroleum are separated by means of distillation. Petroleum mainly consists of hydrocarbons as well as traces of other organic compounds.The name petroleum covers both naturally occurring unprocessed crude oil and petroleum products that are made up of refined crude oil. A fossil fuel, petroleum is formed when large quantities of dead organisms, mostly zooplankton and algae, are buried underneath sedimentary rock and subjected to both prolonged heat and pressure.Petroleum has mostly been recovered by oil drilling. Drilling is carried out after studies of structural geology, sedimentary basin analysis, and reservoir characterisation. Recent developments in technologies have also led to exploitation of other unconventional reserves such as oil sands and oil shale.
Plasma is one of the four fundamental states of matter. It contains a significant portion of charged particles ¿ ions and/or electrons. The presence of these charged particles is what primarily sets plasma apart from the other fundamental states of matter. It is the most abundant form of ordinary matter in the universe, being mostly associated with stars, including the Sun.It extends to the rarefied intracluster medium and possibly to intergalactic regions. Plasma can be artificially generated by heating a neutral gas or subjecting it to a strong electromagnetic field.The presence of charged particles makes plasma electrically conductive, with the dynamics of individual particles and macroscopic plasma motion governed by collective electromagnetic fields and very sensitive to externally applied fields. The response of plasma to electromagnetic fields is used in many modern technological devices, such as plasma televisions or plasma etching.Depending on temperature and density, a certain amount of neutral particles may also be present, in which case plasma is called partially ionized. Neon signs and lightning are examples of partially ionized plasmas.
Graphene has emerged as one of the most promising nanomaterials because of its unique combination of exceptional properties: it is not only the thinnest but also one of the strongest materials; it conducts heat better than all other materials; it is an excellent conductor of electricity; it is optically transparent, yet so dense that it is impermeable to gases ¿ not even helium, the smallest gas atom, can pass through it.Graphene is the name for a single layer (monolayer) sheet of carbon atoms that are bonded together in a repeating pattern of hexagons. This sheet is only one atom thick. Monolayers of graphene stacked on top of each other form graphite. Since a typical carbon atom has a diameter of about 0.33 nanometers, there are about 3 million layers of graphene in a 1 mm thick sheet of graphite. In scientific terms: The extraordinary characteristics of graphene originate from the 2p orbitals, which form the ¿ state bands that delocalize over the sheet of carbons that constitute graphene. Harder than diamond yet more elastic than rubber; tougher than steel yet lighter than aluminum.
Microscale Chemistry (often referred to as small-scale chemistry, in German: Chemie im Mikromaßstab) is an analytical method and also a teaching method widely used at school and at university levels, working with small quantities of chemical substances. While much of traditional chemistry teaching centers on multi-gramme preparations, milligrams of substances are sufficient for micro scale chemistry. In universities, modern and expensive lab glassware is used and modern methods for detection and characterization of the produced substances are very common. In schools and in many countries of the Southern hemisphere, small-scale working takes place with low-cost and even no-cost material. There has always been a place for small-scale working in qualitative analysis, but the new developments can encompass much of chemistry a student is likely to meet.Micro-chemical chip is several-centimeter squared glass substrate with channels of few tens to few hundreds micrometer. Chemical manipulations such as mixing, reaction, separation, detection and synthesis can take place in the minute sections of each channel.
Nanotechnology is already making new materials available that could revolutionize many areas of manufacturing. For example, nanotubes and Nano particles, which are tubes and particles only a few atoms across, and aerogels, materials composed of very light and strong materials with remarkable insulating properties, could pave the way for new techniques and superior products. In addition, robots that are only a few nanometers in length, called Nano-bots, and Nano-factories could help construct novel materials and objects.In 2021, MIT's Department of Materials Science and Engineering (DMSE) announced that they have developed a new class of artificially created 2D molecules that spontaneously assemble Nano-ribbons that are stronger than steel. Previous attempts to create Nano-ribbons had always been dependent on biological processes which would break down over time. These new molecules don't break down, even when they are outside of water.Nanotechnology may transform the ways in which we obtain and use energy. In particular, it's likely that nanotechnology will make solar power more economical by reducing the cost of constructing solar panels and related equipment.
There are various types of renewable energy sources used globally including, bioenergy, solar energy, hydropower, and geothermal energy, to name a few. Globally, China and Brazil are the top two countries in terms of generating the most energy through hydropower. Geothermal energy has been on the rise as well. Data shows an increase in geothermal energy capacity globally in the last 10 years. Likewise, there has been a dramatic increase in the capacity of global solar energy in recent years.Having about 800 citations, all of which are well and completely addressed at the end of the book, shows my meticulousness and accuracy in using all the important sources in writing this book. I hope you like this book.In fact, we should listen to the proposal of the Saudi Minister of Energy in the 1970s, who said:"The Stone Age did not end because the stone ran out.The age of oil must end much sooner than the oil runs out."SoLadies and gentlemen!Welcome to the age of new Energies¿
Water conflict is a term describing a conflict between countries, states, or groups over the rights to access water resources. The United Nations recognizes that water disputes result from opposing interests of water users, public or private. A wide range of water conflicts appear throughout history, though rarely are traditional wars waged over water alone. Instead, water has historically been a source of tension and a factor in conflicts that start for other reasons. However, water conflicts arise for several reasons, including territorial disputes, a fight for resources, and strategic advantage. A comprehensive online database of water-related conflict -the Water Conflict Chronology- has been developed by the Pacific Institute. This database lists violence over water going back nearly 6,000 years. The institutions created by these agreements can, in fact, be one of the most important factors in ensuring cooperation rather than conflict. I hope you like this book.In fact, if the water crisis is not stopped, the name of this book should be remembered:Next station: The Inferno!So Ladies and gentlemen!Welcome to the new era of the world water crisis
Welcome to the timely publication of this book entitled: ¿Renewable Energy; The last chance to survive for Planet¿.Renewable energy is energy that is collected from renewable resources that are naturally replenished on a human timescale. It includes sources such as sunlight, wind, rain, tides, waves, and geothermal heat.Energy experts believe that renewable energy should replace conventional energy sources such as oil and gas in the 21st century to reduce the wasteful use of hydrocarbon products and that future energy use depends on a structure in which carbon-free energy sources such as solar energy. Or wind to be used. A way to overcome the energy crisis and the time bomb that seems to be tuned to announce the end of energy at any moment. In the book in front of you, chapter by chapter, the types of renewable energy are examined and finally its advantages and even disadvantages are expressed!Having about 660 citations, all of which are well and completely addressed at the end of the book, shows my meticulousness and accuracy in using all the important sources in writing this book. I hope you like this book.Ladies and gentlemen!Welcome to the age of new Energies!
Tilmeld dig nyhedsbrevet og få gode tilbud og inspiration til din næste læsning.
Ved tilmelding accepterer du vores persondatapolitik.