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 […]