Wave reflection phenomenon at the stress-free/rigid surface of a piezoelectric fiber-reinforced composite (PFRC) half-space is studied. The PFRC is micro-mechanically modeled using Strength of ...Materials (SM) and Rule of Mixtures (RM). Some of its electro-mechanical data are graphically shown and its advantages are discussed. An incident quasi-longitudinal (qP) wave generates reflected quasi-longitudinal (qP), quasi-transverse (qSV), and electroacoustic (EA) waves, whose propagation angles are graphically demonstrated. Closed-form expressions of energy ratios of reflected waves and interaction energy are obtained, which satisfy the Law of Conservation of Energy, thus validating this problem. Influences of incident angle, varying fiber volume fractions, and stress-free/rigid surfaces on amplitude/energy ratios are discussed.
•Char (island) dwellers’ risk perceptions and agricultural adaptations to climate change are standardized in an index.•Char dwellers climate change risk perceptions and adaptation strategies vary ...substantially.•HAge, family size, annual income, farm size, farm ownership and farming experience significantly influence adaptation choice.•Early warning by extension agents, information on improved technologies, off-farm income can enhance farmerss resilience.
Farmers in the riverine char islands of Bangladesh are frequently affected by climate change due to their proximity to the river and heavy reliance on agriculture for their livelihoods. The present study evaluates char dwellers’ risk perceptions and agricultural adaptations to climate change. Survey data were collected from 98 households, and focus group discussions were conducted using a semi-structured questionnaire from Rydas Bari char under the Gaibandha District of Bangladesh. A standardized risk perception index was created using a four-point Likert scale against sixteen climatic events. In addition, a binary logit model was used to estimate the influence of socioeconomic characteristics of sample households on the decision to choose climate change adaptation strategies. Findings suggest that droughts, river erosion, and floods are the major climatic risks perceived by char dwellers. Additionally, results from a climate vulnerability index portray similar findings that char respondents are more exposed to diverse climatic hazards. The study further investigates local adaptation mechanisms in agriculture with regards to major climatic events. In response to the existing climate change risks, the char inhabitants employ several adaptation strategies in agriculture such as implementing new or alternative farming practices, changing planting times, and cultivating short-duration varieties. The llogit analysis suggests that household age, family size, annual income, farm size, farm ownership and farming experience have a significant influence on farmers' adaptation choices. Household access to education, early warning by extension agents, information on improved agricultural technologies, access to off-farm sources of income and incorporating char people during policy design can effectively enhance farmers’ resilience and help reduce vulnerability.
Aliment Pharmacol Ther 2011; 33: 662–671
Summary
Background Minimal hepatic encephalopathy (MHE) is characterised by subtle neurocognitive deficits without overt clinical manifestations. Although ...several trials have individually evaluated the role of prebiotics, probiotics and synbiotics, there is yet no consensus on the management of MHE.
Aim To estimate the efficacy of prebiotics, probiotics and synbiotics in MHE in randomised controlled trials.
Methods MEDLINE, EMBASE, CINAHL and the Cochrane Database of Systematic Reviews were searched for published studies in all languages. Inclusion and exclusion criteria were defined a priori. Pooled relative risk and heterogeneity were estimated as the measures of association.
Results Nine studies met our inclusion criteria. Use of prebiotics, probiotics and synbiotics significantly reduced the pooled relative risk (RR) of no improvement of MHE (RR 0.40, 95% CI 0.32–0.50; P < 0.001). Upon subgroup analysis, five studies with lactulose showed significant reduction of risk of no improvement of MHE (RR 0.34, 95% CI 0.24–0.47; P < 0.0001) with no inter‐trial heterogeneity. In two trials each of probiotics and synbiotics, their use was associated with significant beneficial effects (RR 0.41, 95% CI 0.26–0.65; P < 0.0001 and RR of 0.51, 95% CI 0.32–0.80; P = 0.004 respectively). There were no major adverse events though probiotics and synbiotics were better tolerated than lactulose.
Conclusions The use of prebiotics, probiotics and synbiotics was associated with significant improvement in minimal hepatic encephalopathy. Among individual agents, lactulose appears to have the most beneficial effect, followed closely by probiotics and synbiotics.
Holevo, Schumacher, and Westmoreland's coding theorem guarantees the existence of codes that are capacity-achieving for the task of sending classical data over a channel with classical inputs and ...quantum outputs. Although they demonstrated the existence of such codes, their proof does not provide an explicit construction of codes for this task. The aim of this paper is to fill this gap by constructing near-explicit "polar" codes that are capacity-achieving. The codes exploit the channel polarization phenomenon observed by Arikan for the case of classical channels. Channel polarization is an effect in which one can synthesize a set of channels, by "channel combining" and "channel splitting," in which a fraction of the synthesized channels are perfect for data transmission, while the other channels are completely useless for data transmission, with the good fraction equal to the capacity of the channel. The channel polarization effect then leads to a simple scheme for data transmission: send the information bits through the perfect channels and "frozen" bits through the useless ones. The main technical contributions of this paper are threefold. First, we leverage several known results from the quantum information literature to demonstrate that the channel polarization effect occurs for channels with classical inputs and quantum outputs. We then construct linear polar codes based on this effect, and the encoding complexity is O ( N log N ), where N is the blocklength of the code. We also demonstrate that a quantum successive cancellation decoder works well, in the sense that the word error rate decays exponentially with the blocklength of the code. For this last result, we exploit Sen's recent "noncommutative union bound" that holds for a sequence of projectors applied to a quantum state.
For decades, the appealing potential of tandem solar cells for efficiencies beyond the single-junction Shockley-Queisser limit has led researchers to develop thin film tandem solutions for high ...performance low cost solar cells. Perovskite solar cells have recently emerged as a promising candidate for photovoltaics. In addition to ease of fabrication and good efficiencies, a particularly attractive feature is their tunable band gap between 1.48 and 2.3 eV that enables symbiosis with other solar cells in tandem device configurations. The low-temperature processing conditions of perovskites make it possible to monolithically integrate them as the top component of tandem structures without damaging the bottom cell. Early experimental results and modelling indicate that efficiencies beyond 25% are within reach. Optimization and solving perovskite stability limitations could result in a commercially viable technology. We review recent developments and insights in the field.
For decades, the appealing potential of tandem solar cells for efficiencies beyond the single-junction Shockley-Queisser limit has led researchers to develop thin film tandem solutions for high performance low cost solar cells.
This paper presents an analytical treatment of the study of reflection and refraction characteristics of plane waves at different types of imperfect interfaces between two dissimilar, ...piezothermoelastic half-spaces. The classical dynamical coupled theory, Lord-Shulman theory and Green-Lindsay theory have been employed to investigate the problem. The existence of four types of plane waves (qP, qSV, T-mode and EA waves) has been observed in the two-dimensional model of the piezothermoelastic media. The imperfection at the interface has been classified into seven types, viz. normal stiffness boundary, transverse stiffness boundary, thermal contact conductance, slip boundary, welded contact, complete debonding and electric imperfection. The closed form expressions of the amplitude ratios of reflected and refracted waves have been obtained which established their dependency on the angle of incidence, the bonding parameters and the properties of the media. The impact of the aforementioned parameters in the aforesaid three theories of thermoelasticity has been extensively studied and demonstrated in graphs. This study may find noteworthy practical applications towards optimization of design and fabrication of surface wave filter devices and temperature sensors and also may be useful for achieving a superior performance in surface acoustic wave devices (such as filters, oscillators, amplifiers etc.).
Analyzed the influence of normal/shear initial stresses and rotation on reflection/transmission characteristics of waves propagating at the interface of two distinct micro-mechanically modeled ...piezomagnetic fiber-reinforced composite(PMFRC) half-spaces composed of CoFe
2
O
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fiber-epoxy matrix combination. An incident quasi-longitudinal(qP) wave generates reflected/transmitted quasi-longitudinal(qP), quasi-transverse(qSV), and magneto-acoustic(MA) waves, whose propagation directions are illustrated graphically. Transmitted qP wave has critical angles for considered initial stresses and rotation. Energy ratios of reflected/transmitted waves, interaction energy, and net energy are obtained, which satisfy the Law of Conservation of Energy, thereby validating this problem. Influences of incident angle, initial stresses, and rotation on amplitude/energy ratios are meticulously analyzed.
In this work we study, using experiments and theoretical modeling, the mechanical and optical properties of tensile strained Ge microstructures directly fabricated in a state-of-the art complementary ...metal-oxide-semiconductor fabrication line, using fully qualified materials and methods. We show that these microstructures can be used as active lasing materials in mm-long Fabry-Perot cavities, taking advantage of strain-enhanced direct band gap recombination. The results of our study can be realistically applied to the fabrication of a prototype platform for monolithic integration of near infrared laser sources for silicon photonics.
Ferroelectric and magnetic materials are a time-honoured subject of study and have led to some of the most important technological advances to date. Magnetism and ferroelectricity are involved with ...local spins and off-centre structural distortions, respectively. These two seemingly unrelated phenomena can coexist in certain unusual materials, termed multiferroics. Despite the possible coexistence of ferroelectricity and magnetism, a pronounced interplay between these properties has rarely been observed. This has prevented the realization of multiferroic devices offering such functionality. Here, we report a striking interplay between ferroelectricity and magnetism in the multiferroic TbMn2O5, demonstrated by a highly reproducible electric polarization reversal and permanent polarization imprint that are both actuated by an applied magnetic field. Our results point to new device applications such as magnetically recorded ferroelectric memory.
We discuss the potential impacts on the CMSSM of future LHC runs and possible
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and higher-energy proton–proton colliders, considering searches for supersymmetry via
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events, precision ...electroweak physics, Higgs measurements and dark matter searches. We validate and present estimates of the physics reach for exclusion or discovery of supersymmetry via
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searches at the LHC, which should cover the low-mass regions of the CMSSM parameter space favoured in a recent global analysis. As we illustrate with a low-mass benchmark point, a discovery would make possible accurate LHC measurements of sparticle masses using the MT2 variable, which could be combined with cross-section and other measurements to constrain the gluino, squark and stop masses and hence the soft supersymmetry-breaking parameters
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of the CMSSM. Slepton measurements at CLIC would enable
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to be determined with high precision. If supersymmetry is indeed discovered in the low-mass region, precision electroweak and Higgs measurements with a future circular
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collider (FCC-ee, also known as TLEP) combined with LHC measurements would provide tests of the CMSSM at the loop level. If supersymmetry is not discovered at the LHC, it is likely to lie somewhere along a focus-point, stop-coannihilation strip or direct-channel
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resonance funnel. We discuss the prospects for discovering supersymmetry along these strips at a future circular proton–proton collider such as FCC-hh. Illustrative benchmark points on these strips indicate that also in this case FCC-ee could provide tests of the CMSSM at the loop level.
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