251 research outputs found
Glide Symmetry Breaking and Quantum Criticality in the Ising Magnet CoNb2O6
No full textSee Readme.txt for details
Recent advances in the production of value added chemicals and lipids utilizing biodiesel industry generated crude glycerol as a substrate - Metabolic aspects, challenges and possibilities: An overview
No full textOne of the major ecological concerns associated with biodiesel production is the generation of waste/
crude glycerol during the trans-esterification process. Purification of this crude glycerol is not economically
viable. In this context, the development of an efficient and economically viable strategy would be
biotransformation reactions converting the biodiesel derived crude glycerol into value added chemicals.
Hence the process ensures the sustainability and waste management in biodiesel industry, paving a path
to integrated biorefineries. This review addresses a waste to wealth approach for utilization of crude glycerol
in the production of value added chemicals, current trends, challenges, future perspectives, metabolic
approaches and the genetic tools developed for the improved synthesis over wild type
microorganisms were described
RETRACTED: Water hyacinth a potential source for value addition: An overview
No full textWater hyacinth a fresh water aquatic plant is considered as a noxious weed in many parts of the world since it grows very fast and depletes nutrients and oxygen from water bodies adversely affecting the growth of both plants and animals. Hence conversion of this problematic weed to value added chemicals and fuels helps in the self-sustainability especially for developing countries. The present review discusses the various value added products and fuels which can be produced from water hyacinth, the recent research and developmental activities on the bioconversion of water hyacinth for the production of fuels and value added products as well as its possibilities and challenges in commercialization. (C) 2017 Elsevier Ltd. All rights reserved.GR-G
Realising complex quantum states of matter via symmetries and heating
No full textIdentifying mechanisms which can guide many-body quantum systems into regimes where properties such as entanglement and long-range coherence are manifest is a fundamental goal for those working in the field of strongly correlated systems. With this comes the potential to realise and exploit states of matter such as superconductors and superfluids, where quantum behaviour is observable at the macroscopic level.
In this thesis we study how symmetries and heating can, counterintuively, be used to realise phases of matter with such desirable properties. We prove how heating a many-body system whilst preserving certain symmetries - such as those of the special unitary group - result in the formation of maximum entropy states which are confined to a subspace of the total Hilbert space and are capable of possessing finite, completely uniform off-diagonal correlations. This mechanism is termed heating-induced order and is independent of any microscopic details.
We use the Hubbard model as a central example where this mechanism can be observed. Heating is introduced to the system via periodic driving or local dissipation and we study the various ordered steady states which emerge in this setup. We discuss the applicability of this mechanism to the thermodynamic limit and its relevance to recent solid-state experiments observing photo-induced superconductivity in irradiated compounds.
We then show how, in an open quantum system, the satisfaction of a set of simple symmetry-based conditions guarantees an absence of stationarity and the formation of coherent oscillations in the long-time limit. We prove how this result subsumes and goes beyond the established notion of a Decoherence Free Subspace. When these conditions are satisfied in the presence of heating-induced order we observe the formation of an entangled, correlated state undergoing identical limit cycles at all positions in space. This leads us to formulate a novel process for quantum synchronisation which is based on the combination of these symmetry-based conditions and the mechanism of heating-induced order
Application of a new xylanase activity from Bacillus amyloliquefaciens XR44A in brewer's spent grain saccharification
No full textCellulases and xylanases are the key enzymes involved in the conversion of lignocelluloses into fermentable sugars. Western Ghat region (India) has been recognized as an active hot spot for the isolation of new microorganisms. The aim of this work was to isolate new microorganisms producing cellulases and xylanases to be applied in brewer's spent grain saccharification
Climate change and diatoms
No full textClimate change has triple-pronged effects – warming, deoxygenation, and acidification – in freshwater and marine environments, effects which have a full spectrum of impacts on primary producers. Diatoms are an appropriate model for indicating climate change effects because they are ubiquitous in aquatic ecosystems and are the most important primary producers in marine ecosystems (i.e., 40% of productivity) and contribute 20% of atmospheric oxygen, but have not been adequately studied in relation to climate change. Diatoms have numerous characteristics that can be used to measure the effects of climate change. For example, climate change may increase the relative abundance of dinoflagellates compared to diatoms, leading to more frequent occurrences of harmful algal blooms in marine ecosystems, where diatoms and dinoflagellates dominate blooms. Such blooms can have far-reaching impacts on ecosystems and can impact on humans by affecting fisheries, tourism, and other economic losses. These changing climatic scenarios may be accompanied by a change in the various life-forms of diatoms, such as a shift from mixed life-forms (undisturbed) to the dominance of pioneer and adnate diatoms (disturbed by an increase in carbon dioxide concentration) in the community. Diatoms store excess energy as lipids, and the number and biovolume of lipid bodies can be a valuable diagnostic tool for stress, including climate change. At the molecular level, organic lipid biomarkers can provide information to help decipher past and present climatic conditions, such as glaciation and deglaciation processes in polar regions. Reductions in diatom size and silica availability for frustule formation have been linked to increasing temperatures, such as those from global warming, in both freshwater and oceanic ecosystems – although not all studies are supportive. Finally, diatoms are excellent experimental organisms for indicating potential impacts of climate change on living organisms
Waste to wealth: valorization of food waste for the production of fuels and chemicals
No full textFood waste is becoming a major global concern especially in developing and underdeveloped countries. Vegetable and food waste biomass is continuously generated in huge amounts. Its major impact on the environment is the generation of greenhouse gases. Food wastes are generated at different stages like production, handling, storage, processing, as well as consumption. First-generation technologies used for food waste disposal include landfill, incineration, and composting. But these strategies are not satisfactory for food wastes since they produce toxic methane gas and bad odor and have slow reaction kinetics. This can be addressed to a certain extent by adopting alternative strategies of food waste valorization by converting wastes to value-added products like fuels and chemicals. Food waste valorization will provide a green process with least environmental impact. This chapter discusses the latest trends in food waste valorization for the production of fuels and chemicals.GR-G
Quantum Hall valley nematics
No full textTwo-dimensional electron gases in strong magnetic fields provide a canonical platform for realizing a variety of electronic ordering phenomena. Here we review the physics of one intriguing class of interaction-driven quantum Hall states: quantum Hall valley nematics. These phases of matter emerge when the formation of a topologically insulating quantum Hall state is accompanied by the spontaneous breaking of a point-group symmetry that combines a spatial rotation with a permutation of valley indices. The resulting orientational order is particularly sensitive to quenched disorder, while quantum Hall physics links charge conduction to topological defects. We discuss how these combine to yield a rich phase structure, and their implications for transport and spectroscopy measurements. In parallel, we discuss relevant experimental systems. We close with an outlook on future directions
Mesenteric inflammatory veno-occlusive disease of the colon: An under-recognized entity - A Case Report
No full textIsolated nonthrombotic venulitis of the colon with concomitant ischemic injury, also known as mesenteric inflammatory veno-occlusive disease (MIVOD), is a rare inflammatory vascular disorder of unknown etiology. First described in 1994, there are only about 34 cases in the literature. We report a 25-year-old woman who presented with loose stools and abdominal pain of 3-week duration. Investigations revealed eosinophilia. Endoscopy showed erosion and ulcers of the gastrointestinal tract, with mucosal biopsies showing features of ischemic injury. Computed tomography showed an edematous and thickened colonic wall with impending perforation, hence, a subtotal colectomy was performed. The patient, however, had a cardiac arrest and expired despite adequate measures. The resection specimen was consistent with a diagnosis of MIVOD. As the clinical and radiological features of MIVOD are nonspecific and overlap with inflammatory bowel disease or mesenteric ischemic disorders, histopathological examination of the resection specimen is the mainstay for its diagnosis. We believe this is the only other case in the literature of MIVOD with eosinophil predominance
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