Phys.org August 2, 2021 The strong erosion in the Himalayas was assumed to be a primary driver of Cenozoic atmospheric CO2 decline and global cooling predominantly through accelerating silicate chemical weathering in the India-Asia collision zone or through effective burial of organic carbon in the nearby Bengal Fan in South Asia. An international team of researchers (China, France) has found that the northward advance of the East Asian monsoon on tectonically inactive subtropical China induced globally significant silicate weathering atmospheric CO2 sink. The organic carbon burial flux is approximately 25% of the contemporary CO2 consumption by silicate weathering. The unusual […]
China to release updated climate plans ‘in near future’: envoy
Phys.org August 3, 2021 Climate negotiators from 196 countries and the European Union as well as businesses, experts and world leaders will gather in Glasgow in November for the 2021 United Nations Climate Change Conference (COP26) summit. Under the Paris Agreement, countries are meant to have submitted updated 2030 climate targets ahead of COP26, but nearly half have yet to do so. China said they will soon release their updated plans. The United Nations is pushing for a global coalition committed to net zero carbon emissions by 2050 which will cover all countries. Many scientists now say 1.5 degrees must […]
A comprehensive study of technological change
MIT News August 2, 2021 Researchers at MIT have provided predicted yearly performance improvement rates for nearly all definable technologies by creating a correspondence of all patents within the US patent system to a set of 1757 technology domains. A technology domain is a body of patented inventions achieving the same technological function using the same knowledge and scientific principles. The domains contain 97.2% of all patents within the entire US patent system. From the identified patent sets, they calculated the average centrality of the patents in each domain to predict their improvement rates, following a patent network-based methodology tested […]
Concrete and the hard-core bacteria that stubbornly persist within
Phys.org August 4, 2021 Researchers at the University of Delaware hypothesized that the microbial communities of concrete reflect those of the concrete components and that these communities change as the concrete ages. To show how microbial communities change over 2 years of outdoor weathering they used two sets of concrete cylinders, one prone to the concrete-degrading alkali-silica reaction (ASR) and the other having the risk of the ASR mitigated. After identifying and removing taxa that were likely laboratory or reagent contaminants, they found that precursor materials, particularly the large aggregate (gravel), were the probable source of ∼50 to 60% of […]
Effective EMI shielding behavior of thin graphene/PMMA nanolaminates
Phys.org August 4, 2021 The use of graphene in a form of discontinuous flakes in polymer composites limits the full exploitation of the unique properties of graphene, thus requiring high filler loadings for achieving satisfactory electrical and mechanical properties. An international team of researchers (Greece, Italy) produced centimetre-scale CVD graphene/polymer nanolaminates by using an iterative ‘lift-off/float-on’ process. These have outperformed, for the same graphene content, state-of-the-art flake-based graphene polymer composites in terms of mechanical reinforcement and electrical properties. The thin laminate materials have shown a high electromagnetic interference (EMI) shielding effectiveness, reaching 60 dB for a small thickness of 33 μm, […]
Engineers bend light to enhance wavelength conversion
Nanowerk July 30, 2021 Incoming light can hit the electrons in the semiconductor lattice and move them to a higher energy state creating an electric field which further accelerates the high-energy electrons. They unload the extra energy by radiating it at different optical wavelengths, thus converting the wavelengths. An international team of researchers (USA – UCLA, Iowa State University, Germany) devised a solution for improving wavelength conversion using the semiconductor surface state phenomenon. They incorporated a nanoantenna array that bends incoming light, so it is confined around the shallow surface of the semiconductor converting the wavelength easily and without any […]
Exotic property of ‘ambidextrous’ crystals points to new magnetic phenomena
Phys.org August 4, 2021 Researchers in Sweden used symmetry-based analysis and numerical computations to predict the existence of antichiral ferromagnetism—a kind of ferromagnetic ordering when both types of chirality (handedness) exist simultaneously and alternate in space. They predicted a fundamentally different magnetic ordering in tetrahedral ferromagnets. They showed that antichiral ferromagnetism can be observed in a class of crystals in which many minerals are formed naturally by studying magnetic ordering in the structure with tetrahedral crystal symmetry and used micromagnetic analysis to derive the new antichiral ordering. The proposed magnetic ordering might result in a rich family of magnetic phenomena […]
Here’s What Ancient Climate Tipping Points May Be Able to Reveal About Earth’s Future
Science Alert July 30, 2021 In many cases, abrupt changes arise from slow changes in one component of the Earth system that eventually pass a critical threshold after which impacts cascade through coupled climate–ecological–social systems. The geological record provides the only long-term information we have on the conditions and processes that can drive physical, ecological, and social systems into new states or organizational structures that may be irreversible within human time frames. An international team of researchers (Germany, USA – Oregon State University, University Wisconsin, Arizona State University Tempe, UMass Amherst, Columbia University, USGS, University of Colorado, Northern Arizona University, […]
Major Atlantic Ocean current system might be approaching critical threshold
Science Daily August 5, 2021 The Atlantic Meridional Overturning Circulation, or AMOC, transports warm water masses from the tropics northward at the ocean surface and cold water southward at the ocean bottom. It influences weather systems worldwide. A potential collapse of this ocean current system could have severe consequences. An international team of researchers (Germany, UK) have developed a robust and general early-warning indicator for forthcoming critical transitions. Significant early-warning signals are found in eight independent AMOC indices, based on observational sea-surface temperature and salinity data from across the Atlantic Ocean basin. The findings support the assessment that the AMOC […]
A major challenge to harvesting fusion energy on Earth
Phys.org August 5, 2021 A key challenge to producing the fusion energy is preventing the runaway electrons that can bore holes in tokamaks. To see the electrons so that they can find ways to stop them before their population can grow into an avalanche an international team of researchers (USA – Princeton University, University of Wisconsin, Edgewood College, Japan, Switzerland) used a multi-energy pinhole camera which has the unique ability to record not only the properties of the plasma in time and space but its energy distribution as well. Use of the novel camera moves technology forward. Comparing their diagnosis […]