In 1970, scientists detected amino acids in a meteorite. Fifty years later, a variety of chemical ingredients for life have been found in other space rocks.
Category: chemistry – Page 280
The photovoltaic effect of ferroelectric crystals can be increased by a factor of 1000 if three different materials are arranged periodically in a lattice. This has been revealed in a study by researchers at Martin Luther University Halle-Wittenberg (MLU). They achieved this by creating crystalline layers of barium titanate, strontium titanate and calcium titanate which they alternately placed on top of one another. Their findings, which could significantly increase the efficiency of solar cells, were published in the journal Science Advances.
Most solar cells are currently silicon based; however, their efficiency is limited. This has prompted researchers to examine new materials, such as ferroelectrics like barium titanate, a mixed oxide made of barium and titanium. “Ferroelectric means that the material has spatially separated positive and negative charges,” explains physicist Dr Akash Bhatnagar from MLU’s Centre for Innovation Competence SiLi-nano. “The charge separation leads to an asymmetric structure that enables electricity to be generated from light.” Unlike silicon, ferroelectric crystals do not require a so-called pn junction to create the photovoltaic effect, in other words, no positively and negatively doped layers. This makes it much easier to produce the solar panels.
However, pure barium titanate does not absorb much sunlight and consequently generates a comparatively low photocurrent. The latest research has shown that combining extremely thin layers of different materials significantly increases the solar energy yield. “The important thing here is that a ferroelectric material is alternated with a paraelectric material. Although the latter does not have separated charges, it can become ferroelectric under certain conditions, for example at low temperatures or when its chemical structure is slightly modified,” explains Bhatnagar.
Boston startup Form Energy has secured $200 million Series D funding for the development of what is being called a breakthrough in energy storage. #solarenergy #solarpv #solar
Solar and wind power have variability in their productive hours, as multi-day weather events can impact output. Therefore, multi-day storage that is cost effective is important in grid reliability.
Boston startup Form Energy developed technology to address this need, revealing recently the chemistry behind their iron-air batteries. The company said its iron-air batteries can deliver renewables-sourced electricity for 100 hours at system costs competitive with conventional power plants. At full-scale production, Form Energy said the modules would deliver electricity at tenth the cost of lithium-ion batteries.
The iron-air battery is composed of cells filled with thousands of iron pellets that are exposed to air and create rust. The oxygen is then removed, reverting the rust to iron. Controlling this process allows the battery to be charged and discharged.
The University of Surrey has built an artificial intelligence (AI) model that identifies chemical compounds that promote healthy aging — paving the way towards pharmaceutical innovations that extend a person’s lifespan.
In a paper published by Nature Communication’s Scientific Reports, a team of chemists from Surrey built a machine learning model based on the information from the DrugAge database to predict whether a compound can extend the life of Caenorhabditis elegans — a translucent worm that shares a similar metabolism to humans. The worm’s shorter lifespan gave the researchers the opportunity to see the impact of the chemical compounds.
The AI singled out three compounds that have an 80 percent chance of increasing the lifespan of elegans:
A new tool that enables thousands of tiny experiments to run simultaneously on a single polymer chip will let scientists study enzymes faster and more comprehensively than ever before.
For much of human history, animals and plants were perceived to follow a different set of rules than rest of the universe. In the 18th and 19th centuries, this culminated in a belief that living organisms were infused by a non-physical energy or “life force” that allowed them to perform remarkable transformations that couldn’t be explained by conventional chemistry or physics alone.
Scientists now understand that these transformations are powered by enzymes – protein molecules comprised of chains of amino acids that act to speed up, or catalyze, the conversion of one kind of molecule (substrates) into another (products). In so doing, they enable reactions such as digestion and fermentation – and all of the chemical events that happen in every one of our cells – that, left alone, would happen extraordinarily slowly.
The University of Surrey has built an artificial intelligence (AI) model that identifies chemical compounds that promote healthy aging—paving the way towards pharmaceutical innovations that extend a person’s lifespan.
For decades, researchers around the world have searched for ways to use solar power to generate the key reaction for producing hydrogen as a clean energy source—splitting water molecules to form hydrogen and oxygen. However, such efforts have mostly failed because doing it well was too costly, and trying to do it at a low cost led to poor performance.
Now, researchers from The University of Texas at Austin have found a low-cost way to solve one half of the equation, using sunlight to efficiently split off oxygen molecules from water. The finding, published recently in Nature Communications, represents a step forward toward greater adoption of hydrogen as a key part of our energy infrastructure.
As early as the 1970s, researchers were investigating the possibility of using solar energy to generate hydrogen. But the inability to find materials with the combination of properties needed for a device that can perform the key chemical reactions efficiently has kept it from becoming a mainstream method.
The findings, published in Nature Communications, could have important implications for human health: minis have been found at every type of synapse studied so far, and defects in miniature neurotransmission have been linked to range of neurodevelopmental disorders in children. Figuring out how a reduction in miniature neurotransmission changes the structure of synapses, and how that in turn affects behavior, could help to better understand neurodegenerative disorders and other brain conditions.
Summary: Study reveals how miniature release events help to keep neurons intact and preserve motor neuron function in aging insects.
Source: EPFL
Neurons communicate through rapid electrical signals that regulate the release of neurotransmitters, the brain’s chemical messengers. Once transmitted across a neuron, electrical signals cause the juncture with another neuron, known as a synapse, to release droplets filled with neurotransmitters that pass the information on to the next neuron. This type of neuron-to-neuron communication is known as evoked neurotransmission.
However, some neurotransmitter-packed droplets are released at the synapse even in the absence of electrical impulses. These miniature release events — or minis — have long been regarded as ‘background noise’, says Brian McCabe, Director of the Laboratory of Neural Genetics and Disease and a Professor in the EPFL Brain Mind Institute.
Summary: Newly synthesized compounds can halt the degradation of neurons in a range of neurodegenerative diseases, including Alzheimer’s and Parkinson’s disease, researchers say.
Source: Ural Federal University
Russian scientists have synthesized chemical compounds that can stop the degeneration of neurons in Alzheimer’s, Parkinson’s, and other severe brain pathologies. These substances can provide a breakthrough in the treatment of neurodegenerative pathologies.
New molecules of pyrrolyl-and indolylazine classes activate intracellular mechanisms to combat one of the main causes of “aged” brain diseases – an excess of so-called amyloid structures that accumulate in the human brain with age.
Chemical engineer Zhenan Bao and her team of researchers at Stanford have spent nearly two decades trying to develop skin-like integrated circuits that can be stretched, folded, bent and twisted — working all the while — and then snap back without fail, every time. Such circuits presage a day of wearable and implantable products, but one hurdle has always stood in the way.
Namely, “How does one produce a completely new technology in quantities great enough to make commercialization possible?” Bao said. Bao and team think they have a solution. In a new study, the group describes how they have printed stretchable-yet-durable integrated circuits on rubbery, skin-like materials, using the same equipment designed to make solid silicon chips — an accomplishment that could ease the transition to commercialization by switching foundries that today make rigid circuits to producing stretchable ones.
Stanford researchers show how to print dense transistor arrays on skin-like materials to create stretchable circuits that flex with the body to perform applications yet to be imagined.