Energy

Researchers in Korea have overcome a 100-year old technological limitation by fabricating the world’s first Mott device that reduces the size and enhances the performance of traditional electromagnetic switches and circuit breakers. Daejeon, KOREA – The research team, led by Dr. Hyun-Tak Kim of Korea’s Electronics and Telecommunications Research Institute, has developed an innovative power interruption technology based on a Mott metal-insulator transition (Mott MIT) device. The Mott MIT signifies the phenomenon that a Mott insulator is abruptly converted into a metal or vice versa without the structural phase transition. The research team previously developed a Mott MIT critical temperature switch (CTS) (or MIT device) which generates a control current (or signal) at a critical temperature between 67 degrees Celsius and 85 degrees Celsius as the unique characteristic of vanadium dioxide. After that, the MIT devices were applied to some kinds of electromagnetic switches that interrupt an electric current in case of overcurrent. An existing traditional electromagnetic switch that takes the role to interrupt electricity through the mechanical switching when it conducts an overcurrent is composed of both an electromagnet called the magnetic contactor, which connects or disconnects signals of main power, and the thermal overload relay with an on-off switching function controlled by temperature. The overload relay is composed of both an expensive delicate mechanical switch with a large size and a bimetal that is made of two separate metals with different thermal expansion coefficients joined together. The bimetal has a characteristic of bending to any direction when heat is applied. The bending force of the bimetal controls the mechanical switch inducing the on-off switching; this has been called ‘hundred years technology of power interruption’; Westinghouse applied the patent right of the power circuit breaker using a bimetal in 1924. However, the bimetal undergoes a change of the bending […]

The novel cross-axis-wind-turbine (CAWT) is a new type of wind turbine that has the capability to extract energy from multi-directional wind that is commonly found in urban areas due to the interaction of airflows between high-rise buildings. The novel cross-axis-wind-turbine (CAWT) is a new type of wind turbine that has the capability to extract energy from multi-directional wind that is commonly found in urban areas due to the interaction of airflows between high-rise buildings. Its ability to operate in areas with complex wind pattern and low wind speed overcomes the weaknesses of the vertical and horizontal axis wind turbines (VAWT and HAWT). The novel wind turbine consists of vertical and horizontal blades arranged in a cross axis orientation, therefore enabling it to function with airflows coming from horizontal and vertical directions. The horizontal blades serve as the radial arms that link and support the vertical blades and the hubs through specially designed connectors to form the CAWT. Any airflow streams channeled to the bottom of the turbine interact with the lower and upper radial supporting-arms, therefore maximizing the wind energy potential that can be extracted. Viewed from the top, the upper and lower radial arms can be considered as a double-layered HAWT that extracts energy from the vertical wind. Moreover, the lift created by the interaction between the vertical airflow and the horizontal blades creates aero-levitation forces which reduce bearing friction in the generator, hence extending the lifespan of the wind turbine. Initial studies have shown that the CAWT can overcome the problem of self-starting ability of a conventional VAWT, and produce better performance output by up to 2.5 times. In conclusion, the CAWT presents an innovative outlook on the future of wind turbines, creating significant opportunities for the use of wind energy devices and therefore alleviating dependencies on fossil […]

Picture:Metroxylon sagu or commonly known as the Sago palm thrives in tropical lowland forests and freshwater swamps. The state of Sarawak in Malaysia is one of the world’s largest exporters of sago products with annual exports of approximately 43,000 tons. Waste material generated by Malaysia’s sago palm industry has potential for use as an adsorbent for cleaning up oil spills, according to a study published in the Pertanika Journal of Science and Technology. Conducted by Zainab Ngaini and colleagues at the Universiti Malaysia Sarawak, the study found that when sago waste (consisting primarily of cellulose and lignin) is chemically modified using fatty acid derivatives, the resulting material is more hydrophobic than untreated sago waste, implying that it has less affinity for water and an excellent affinity for oil. The authors conclude that chemically modified sago waste may be suitable for applications where engine oil needs to be removed from an aqueous environment. By contrast, untreated sago waste could be used for absorbing oil in a dry environment. Sago palm is commonly found in tropical lowland forests and freshwater swamps. Sarawak is one of the world’s largest exporters of sago products with annual exports of approximately 43,000 tons. However, the mass production of sago produces large amounts of waste residues. From 600 logs of sago palm per day, an estimated 15.6 tons of woody bark, 237.6 tons of waste water and 7.1 tons of starch fibrous sago pith residue are generated. Currently, sago pith residues are either incinerated or discharged into waterways, which eventually contributes to environmental problems. Until now, no studies have examined sago waste’s potential as an oil adsorbent, despite its resemblance to previously studied natural oil sorbents such as cotton, wool and bark.

Sustainability concept in chemistry involves replacement of toxic chemical components with bio-compatible analogues in attempt to produce environmentally friendly materials and technologies. Principles of Green chemistry and Sustainability concept have largely influenced research and development in chemical sciences. These principles include convenient degradability and minimised toxicity. It is a well-known fact that common chemicals are mainly based on toxic, bio-incompatible substances, which are dangerous for the environment. On the contrary, natural components are biocompatible and have no toxic effects. Nowadays, chemists undertake numerous efforts to replace toxic substances with corresponding natural analogues, and fortunately, change of just one component sometimes does increase environmental compatibility and reduces harmful impact. This approach has been used in attempt to create biocompatible ionic liquids. Ionic liquids, also called molten salts, liquid electrolytes, or ionic melts, are salts, which are liquid at temperatures below 100ºC. Spatial directionality and segregated nano-structuring found in ionic liquids provide them with unique properties, one of the most startling of which is the possibility of ‘fine-tuning’: each ionic liquid consists of cation and anion moieties, and by varying them, individually or together, certain properties of the IL can be changed. Being non-volatile and non-flammable substances, ionic liquids were believed to become a replacement to traditional volatile and flammable organic solvents, and have found application in such various fields of modern chemistry and technology as organic synthesis, catalysis, electrochemistry, nuclear fuel processing, and others. Originally, ionic liquids were considered as ‘green’ chemicals; however, their biological potential has quickly become evident. Now it is established that ionic liquids may affect life at all levels, from single biomolecules to whole ecosystems. The authors tested a series of common and amino acid-based ILs and showed that ionic liquids containing anions or cations based on the amino acids Glycine, Alanine, or Valine generally demonstrate cytotoxicity […]

Toyota Central R&D Labs. Inc. in Japan have reviewed research that might be leading the way towards a new generation of automotive catalytic converters. Catalytic converters that change the toxic fumes of automobile exhaust to less toxic pollutants only reached the market in the mid-1970s. They are formed of a catalyst – usually in the form of a precious metal such as platinum, palladium, or rhodium – a catalyst support material, and a wash-coat designed to disperse the catalytic materials over a wide surface area. Toyota Central R&D Labs. Inc. in Japan are involved in research to develop catalysts that are controlled at the quantum-level. With this level of control, “we can expect an extreme reduction of precious metal usage in automotive exhaust catalysts and/or fuel cells,” says Dr. Yoshihide Watanabe, chief researcher at the Toyota Central R&D Labs in Japan. He reviewed research on different types of catalytic reactions involving metal clusters whose sizes were atomically controlled. Metal cluster chemistry has been developing rapidly since the mid-20th century. A cluster is a group of atoms or molecules formed by interactions varying in strength from very weak to strong. Some naturally occurring clusters are known to be involved in catalytic reactions. The study of metal clusters is inspiring great interest, partially for the potential use of synthetic clusters in industrial applications, such as catalysts in catalytic converters. He pointed out that not much research has been done in the area of atomically controlled cluster catalysis, with the exception of studies on carbon monoxide oxidation reaction. His research indicates that catalytic activity is strongly affected by the electronic structure of clusters, their geometry on a support material, and the interaction between the cluster and the material. Thus, the catalytic activity of clusters can be enhanced by controlling cluster size and the […]

A group of scientists from South Korea have converted used-cigarette butts into a high-performing material that could be integrated into computers, handheld devices, electrical vehicles and wind turbines to store energy. The researchers have demonstrated the material’s superior performance compared to commercially available carbon, graphene and carbon nanotubes. It is hoped the material can be used to coat the electrodes of supercapacitors—electrochemical components that can store extremely large amounts of electrical energy—whilst also offering a solution to the growing environmental problem caused by used-cigarette filters. It is estimated that as many as 5.6 trillion used-cigarettes, or 766 571 metric tons, are deposited into the environment worldwide every year. Co-author of the study Professor Jongheop Yi, from Seoul National University, said: “Our study has shown that used-cigarette filters can be transformed into a high-performing carbon-based material using a simple one step process, which simultaneously offers a green solution to meeting the energy demands of society. “Numerous countries are developing strict regulations to avoid the trillions of toxic and non-biodegradable used-cigarette filters that are disposed of into the environment each year—our method is just one way of achieving this.” Carbon is the most popular material that supercapacitors are composed of, due to its low cost, high surface area, high electrical conductivity and long term stability. Scientists around the world are currently working towards improving the characteristics of supercapacitors—such as energy density, power density and cycle stability—whilst also trying to reduce production costs. In their study, the researchers demonstrated that the cellulose acetate fibres that cigarette filters are mostly composed of could be transformed into a carbon-based material using a simple, one-step burning technique called pyrolysis. As a result of this burning process, the resulting carbon-based material contained a number of tiny pores, increasing its performance as a supercapacitive material. “A high-performing supercapacitor material […]