Among the many industrially important zeolites, mordenite is found to be interesting because of its unique and exceptional physical and chemical properties. Mordenite (high silica zeolite) is ...generally prepared by the hydrothermal method using TEA
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cations. TEA
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cations are the best templating agent, though they can create a number of issues, for instance, generating poison and high manufacturing cost, wastewater contamination, and environmental pollution. Hence, it is necessary to find a mordenite synthesis method without using an organic template or low-cost template. In this review, a number of unique sources were used in the preparation of mordenite zeolite, for instance, silica sources (rice husk ash, silica gel, silica fumes), alumina sources (metakaolin, faujasite zeolite) and sources containing both silica and alumina (waste coal fly ash). These synthesis approaches are also based on the absence of a template or low-cost mixed organic templates (for instance, glycerol (GL), ethylene glycol (EG), and polyethylene glycol 200 (PEG)) or pyrrolidine-based mesoporogen (
N
-cetyl-
N
-methylpyrrolidinium) modifying the mordenite framework which can create unique properties. The framework properties and optical properties (indium-exchanged mordenite zeolite) have been discussed. Mordenite is generally used in alkylation, dewaxing, reforming, hydrocracking, catalysis, separation, and purification reactions because of its large pore size, strong acidity, and high thermal and chemical stability, although the applications are not limited for mordenite zeolite. Recently, several applications such as electrochemical detection, isomerization, carbonylation, hydrodeoxygenation, adsorption, biomass conversion, biological applications (antibacterial activity), photocatalysis, fuel cells and polymerization reactions using mordenite zeolite were explored which have been described in detail in this review.
Among the many industrially important zeolites, mordenite is found to be interesting because of its unique and exceptional physical and chemical properties.
Grain boundary engineering (GBE) is a thermomechanical processing strategy to enhance the physical and mechanical properties of polycrystalline metals by purposely incorporating special types of ...grain boundaries—such as twin boundaries (TB)—in the microstructure. Because of the multiple strain-annealing cycles involved, conventional GBE is not directly applicable to near-net-shape parts, such as those produced via additive manufacturing (AM) technology. In this study, we explore a different GBE processing route that leverages TB multiplication during recrystallization of austenitic 316L stainless steel produced via selective laser melting (SLM). We find that recrystallization requires a minimum level of mechanical deformation, which scales with the laser scanning speed employed during SLM. We ascribe this relationship to the cell size and the amount of solute segregating at cell boundaries during rapid solidification, which are inversely and directly proportional to the laser scanning speed, respectively. The coarser the cell structure and the more uniform the chemical composition, the easier the nucleation and growth of recrystallized grains. Our results provide the groundwork for devising AM-compatible GBE strategies to produce high-performance parts with complex geometry.
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Sleep plays an important role in the consolidation of recent memories. However, the cellular and synaptic mechanisms of consolidation during sleep remain poorly understood. In this study, using a ...realistic computational model of the thalamocortical network, we tested the role of Non-Rapid Eye Movement (NREM) sleep in memory consolidation. We found that sleep spindles (the hallmark of N2 stage sleep) and slow oscillations (the hallmark of N3 stage sleep) both promote replay of the spike sequences learned in the awake state and replay was localized at the trained network locations. Memory performance improved after a period of NREM sleep but not after the same time period in awake. When multiple memories were trained, the local nature of the spike sequence replay during spindles allowed replay of the distinct memory traces independently, while slow oscillations promoted competition that could prevent replay of the weak memories in a presence of the stronger memory traces. This could lead to extinction of the weak memories unless when sleep spindles (N2 sleep) preceded slow oscillations (N3 sleep), as observed during the natural sleep cycle. Our study presents a mechanistic explanation for the role of sleep rhythms in memory consolidation and proposes a testable hypothesis how the natural structure of sleep stages provides an optimal environment to consolidate memories.
Sleep is critical for regulation of synaptic efficacy, memories, and learning. However, the underlying mechanisms of how sleep rhythms contribute to consolidating memories acquired during wakefulness ...remain unclear. Here we studied the role of slow oscillations, 0.2-1 Hz rhythmic transitions between Up and Down states during stage 3/4 sleep, on dynamics of synaptic connectivity in the thalamocortical network model implementing spike-timing-dependent synaptic plasticity. We found that the spatiotemporal pattern of Up-state propagation determines the changes of synaptic strengths between neurons. Furthermore, an external input, mimicking hippocampal ripples, delivered to the cortical network results in input-specific changes of synaptic weights, which persisted after stimulation was removed. These synaptic changes promoted replay of specific firing sequences of the cortical neurons. Our study proposes a neuronal mechanism on how an interaction between hippocampal input, such as mediated by sharp wave-ripple events, cortical slow oscillations, and synaptic plasticity, may lead to consolidation of memories through preferential replay of cortical cell spike sequences during slow-wave sleep.
Sleep is critical for memory and learning. Replay during sleep of temporally ordered spike sequences related to a recent experience was proposed to be a neuronal substrate of memory consolidation. However, specific mechanisms of replay or how spike sequence replay leads to synaptic changes that underlie memory consolidation are still poorly understood. Here we used a detailed computational model of the thalamocortical system to report that interaction between slow cortical oscillations and synaptic plasticity during deep sleep can underlie mapping hippocampal memory traces to persistent cortical representation. This study provided, for the first time, a mechanistic explanation of how slow-wave sleep may promote consolidation of recent memory events.
Agriculture sector plays a strategic role in the self-sustaining economic development of a country by providing basic ingredients to mankind and raw material for industrialisation. Agriculture is ...much diversified field, but continuing with technological growth at brisk pace. There is need of technical interventions in the basic principles of food processing, quality assurance, disaster risk identification, diagnosis, and prevention to achieve goal ofregional andglobal food security. Thus to improve consumer livelihood and optimal utilization of resources, rapid, real-time, portable, and cost effective technologies are desired in agriculture. Recent advancements in biosensing technologies and material sciences have played crucial role in understanding agricultural process dynamics through molecular recognising materials, antigen-antibody interaction and subsequent transduction mechanism.
In this article, current trends in the development of biosensors, impact of nanotechnology and miniaturization of biosensors on addressing the new developments of agriculture strategies at different levels have been extensively reviewed. The article intensively brings out the implications of biosensors in various agricultural sectors and future need of improvement in the design and development techniques leading to sustainable development.
Technological advancements in the area of nanobiosenors, bioelectronics, material science, miniaturization techniques, electrode design, fabrication technology, nanolithography and microfluidics have significantly influenced agriculture sector too. There is need to direct our research towards enhancing the shelf life of a biosensor for increasing the acceptability among the end-users. Improvement in basic characteristics of biosensors will lead to widespread application in major challenging areas in agriculture.
•The advances in biosensor technology to address the agriculture challenges have been reviewed.•Biosensors in agriculturewith intervention of nanotechnology will lead to enhanced productivity and sustainability.•Agriculture, livestocks, and natural resources need portable and real time quality and safety monitoring technologies.•The commercial and futuristic biosensors to combat the challenges in major agro-domains are reviewed.
Brain-computer interfaces (BCIs) have recently been shown to be clinically effective as a novel method of stroke rehabilitation. In many BCI-based studies, the activation of the ipsilesional ...hemisphere was considered a key factor required for motor recovery after stroke. However, emerging evidence suggests that the contralesional hemisphere also plays a role in motor function rehabilitation. The objective of this study is to investigate the effectiveness of the BCI in detecting motor imagery of the affected hand from contralesional hemisphere. We analyzed a large EEG dataset from 136 stroke patients who performed motor imagery of their stroke-impaired hand. BCI features were extracted from channels covering either the ipsilesional, contralesional or bilateral hemisphere, and the offline BCI accuracy was computed using 10 Formula: see text 10-fold cross-validations. Our results showed that most stroke patients can operate the BCI using either their contralesional or ipsilesional hemisphere. Those with the ipsilesional BCI accuracy of less than 60% had significantly higher motor impairments than those with the ipsilesional BCI accuracy above 80%. Interestingly, those with the ipsilesional BCI accuracy of less than 60% achieved a significantly higher contralesional BCI accuracy, whereas those with the ipsilesional BCI accuracy more than 80% had significantly poorer contralesional BCI accuracy. This study suggests that contralesional BCI may be a useful approach for those with a high motor impairment who cannot accurately generate signals from ipsilesional hemisphere to effectively operate BCI.
Sleep, specifically non-rapid eye movement (NREM) sleep, is thought to play a critical role in the consolidation of recent memories. Two main oscillatory activities observed during NREM, cortical ...slow oscillations (SO, 0.5-1.0 Hz) and thalamic spindles (12-15 Hz), have been shown to independently correlate with memory improvement. Yet, it is not known how these thalamocortical events interact, or the significance of this interaction, during the consolidation process. Here, we found that systemic administration of the GABAergic drug (zolpidem) increased both the phase-amplitude coupling between SO and spindles, and verbal memory improvement in humans. These results suggest that thalamic spindles that occur during transitions to the cortical SO Up state are optimal for memory consolidation. Our study predicts that the timely interactions between cortical and thalamic events during consolidation, contribute to memory improvement and is mediated by the level of inhibitory neurotransmission.
Voltage angle-based torque control of dual three-phase interior permanent magnet synchronous machines (DTP-IPMSMs) in the field weakening (FW) region offers maximum dc voltage utilization, increased ...speed range, and higher torque capability. However, the difference in parameter values between the two three-phase winding sets results in torque limitations during FW operation. This article considers a dual three-phase IPMSM with 0<inline-formula><tex-math notation="LaTeX">^\circ</tex-math></inline-formula> winding displacement (DTP0 IPMSM), where the resistance and leakage inductance of each three-phase winding set are not the same. The effect of this parameter mismatch on the FW performance is discussed in detail. Further, a control scheme is proposed, where a 2-pole torque controller controls the torque dynamics by modifying the voltage angle of one of the inverters, while the other inverter's voltage angle is controlled to minimize the effect of parameter mismatch. The proposed method is implemented on a 3.68 kW DTP0 IPMSM prototype. For a given torque, the current requirement is shown to reduce approximately by 4% in the low and midspeed ranges of the FW region when compared with existing approaches of DTP0 IPMSM control. The performance of the 2-pole controller is also demonstrated, which achieves the desired control system specifications.
Background and aims Sensitivity and uncertainty analyses are critical for identifying the most sensitive parameters of the crop simulation models. These analyses will help the users to concentrate ...more on calibrating those sensitive parameters. The soil parameters are important input parameters as the soils regulate the supply of nutrients and water required for the growth and yield of crops. The aim of this investigation is to perform the sensitivity and uncertainty analyses of the soil parameter inputs of the Web InfoCrop Wheat model, especially under the water deficit- and high temperature stress conditions for different agro-climatic conditions of India. Methods Sensitivities of soil input parameters (15) were analysed by crop simulations under the no stress (potential), water deficit- (limited irrigation), high temperature- (+3 °C above ambient), and their combined stress conditions for a period of 10 years across four sites in the wheat-growing regions of India. The partial rank correlation coefficients (PRCC) were computed, followed by the top-down concordance coefficients. Results Amongst the soil input parameters (15) and outputs (10) considered, the nutrient parameters such as NITRATE, ORG CARB (Organic carbon), AMMONIUM were the most sensitive input parameters under the no stress (potential) and high temperature stress conditions. On the contrary, the parameters related to the soil moisture such as CLAY (Clay %), FLD_CAP (Field capacity), SATU (Saturation) and MOISTURE (initial soil moisture contents) were the most sensitive input parameters under water deficit stress conditions. Conclusions Both the sensitivities and uncertainty of soil parameters under different crop production and environmental conditions influenced the outputs of the Web InfoCrop model significantly. Identification of the most sensitive soil parameters that need to be measured accurately improved the simulation efficiencies of this crop model.
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