Actual Transfer Research Articles

Stochastic Thermodynamics of Nonlinear Electronic Circuits: A Realistic Framework for Computing Around kT

We provide a general theory of nonlinear electronic circuits subjected to thermal noise. The devices constituting the circuit can have arbitrary I−V curves but must display shot noise. This theory includes tunnel junctions, diodes, and MOS transistors in subthreshold operation, among others. The stochastic nonequilibrium thermodynamics of these circuits is also established. The irreversible entropy production is expressed in terms of thermodynamic potentials and forces, and its fluctuations satisfy fluctuation theorems. Our theory is ideally suited to formulate a thermodynamics of computing with realistic architectures, where the reduction in transistor size and operating voltages make thermal fluctuations increasingly important. We demonstrate this point in two ways: first, by proposing a stochastic model of a CMOS inverter whose actual transfer function deviates from the deterministic one due to nonequilibrium fluctuations, and, second, by proposing a low-power full-CMOS design for a probabilistic bit (or binary stochastic neuron) exploiting intrinsic noise.8 MoreReceived 1 October 2020Revised 2 July 2021Accepted 8 July 2021DOI:https://doi.org/10.1103/PhysRevX.11.031064Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasNonequilibrium & irreversible thermodynamicsThermodynamicsThermodynamics of computationPhysical SystemsStochastic dynamical systemsStochastic networksStatistical PhysicsNonlinear DynamicsCondensed Matter, Materials & Applied PhysicsNetworks

Mediation of perceived content validity on motivation and training transfer among smallholder farmers in Central Uganda

AbstractFarmer training is a key strategy for building skills that lead to enhanced productivity of small‐scale farmers' fields. This result hinges on farmers transferring the training to their fields. However, the factors that determine the subsequent transfer of training including those with mediating effects are not fully known. A study was conducted to assess the mediating role of perceived content validity on the association of farmers' motivation to implement acquired knowledge with actual training transfer outcomes from a random sample of 603 Ugandan farmers who had received four agricultural related trainings. Using Structural Equation Modelling, results indicated intrinsic motivation (β = 0.246; t = 2.991; p < 0.05) and perceived content validity (β = 0.325; t = 2.693; p < 0.05) to strongly influence training transfer. Intrinsic motivation predicted up to 45% of variance in farmers' perceptions about training design suitability. Perceived content validity mediated the relationship between intrinsic motivations to implement acquired knowledge and training transfer. In order to improve the transfer of learnt knowledge among smallholder farmers, trainers need to pay attention to pre‐training efforts, such as adopting a criterion of assessment checklist for identifying highly motivated trainees, as mechanisms for obtaining internally motivated training participants.

Investigation on Electron Transfer Process of Oxygen Reduction Reactions Catalyzed by Nitrogen-doped Graphitic Carbon in Acidic and Alkaline Media

The electron transfer number is an important parameter to illustrate oxygen reduction reaction (ORR) pathway and explore reaction processes, which can be obtained by the rotating ring-disk electrode (RRDE) method and the Koutecky−Levich equation. However, the two approaches sometimes lead to different and confusing conclusions. Herein, graphitic carbon, nitrogen-doped graphitic carbon and Pt/C are respectively used as carbon and precious metal catalysts to evaluate the reliability of these two methods to calculate electron transfer numbers in acidic and alkaline media. Furthermore, density functional theory (DFT) calculations are employed to reveal effects of electrical potentials on the 4-electron ORR process in acidic and alkaline media. The results show that the electron transfer number varies with potentials and the RRDE method can provide more objective and actual electron transfer numbers in alkaline and acidic electrolytes from the perspective of experiments and theoretical calculations.

A Blade Dynamic Strain Inversion Method for Rotating Blades Based on Blade Tip Timing

Based on the vibration response transfer ratio and Natural Neighbor Interpolation (NNI), the research on the noncontact inversion method of dynamic strain of high-speed rotating blades is carried out. The high-speed rotating blade is analyzed through the motion equation, and the correction method of the transfer ratio is proposed through NNI. The three-dimensional model of the rotating blade is established, and the Finite Element Analysis (FEA) considering stress stiffening is carried out to obtain the transfer ratio between the blade tip displacement and the blade strain at a certain speed. The vibration experiment of the high-speed rotating blade is carried out, and the blade tip displacement and the dynamic strain of the key points of the blade are obtained based on Blade Tip Timing (BTT) and strain gauges. The experimental data are processed to obtain the actual transfer ratio of the key points of the blade, and the theoretical transfer ratio is corrected based on NNI. The results show that when the 1st-order resonance of the rotating blade occurs at the rotating speed of 7960RPM, the strain inversion error of the test point can be reduced to less than 5%, which verifies the proposed correction method. Therefore, the blade dynamic strain can be inverted more accurately based on BTT.

Problematic questions of donation agreement for the future

The scientific article is devoted to the analysis of problematic issues related to the donation agreement for the future. Despite the fact that the topic of the gift agreement is quite common and sufficiently disclosed in scientific articles, textbooks, manuals and monographs, problematic aspects of the gift agreement with the obligation to transfer the gift in the future is still not given due attention. Due to the lack of interest in this type of contract, there is a small amount of research that is not able to fully disclose its content.
 It is established that the basis for the existence of the donation agreement for the future was the enshrinement in the Civil Code of Ukraine of the possibility of consensus of the donation agreement itself. The paper indicates possible options for the transfer of the thing in the future, as well as the essential conditions, the violation of which entails the invalidity of this type of contract.
 In addition, much attention is paid to the features of the gift agreement with the obligation to transfer the gift in the future, which are not enshrined in law, but they can be easily identified by analyzing scientific papers and articles of the Civil Code of Ukraine on donations.
 This article considers such a feature of the contract of gift for the future as its gratuitousness, which is characterized by its imperative. Occasionally, the connection of gratuitousness with the reasons and motives of the gift is determined, because the donor, concluding this type of contract may express some gratitude to the person, seek to provide him with financial assistance, or encourage the person to take beneficial actions. That is why much attention is paid to the study of practical cases related to reciprocal satisfaction, which goes beyond the contract of gift for the future. In addition, the motives for such actions and the real threats that may be faced by the gifted.
 The next, related to the problematic aspects of the contract of donation for the future, is the considered feature of the property of the alienated property. It also analyzes the possibility of donating a thing that the donor does not yet own. The scientific work argues the refusal to perform the contract on condition of loss of the thing, its withdrawal from circulation, as well as the refusal of the gifted person to accept the gift.
 At the same time, the rights of the donor and the gifted are considered, in case of death of one of them after the relevant term, term, adjournment, but until the actual transfer or acceptance of the gift, outlines the difference between the gift agreement and the will.
 The results of the article emphasize the need for further elaboration and more thorough study of the problematic issues of the donation agreement for the future, as well as the improvement of civil legislation in this area.

Adiabatic compressed air energy storage technology

Adiabatic compressed air energy storage technology

Overhead effects of data encryption on TCP throughput across IPSEC secured network

The transmission control protocol (TCP) is an internet protocol used to send data across networks. When encrypted data are sent across networks, additional overhead is incurred. The data to be secured through encryption must be transformed from plain text to Ciphertext, resulting in data size increase. In this paper, the overhead effect of data encryption on TCP throughput across an internet protocol security (IPSec) network was investigated. In particular, we compared the additional data sizes of encrypted data to that of non-encrypted data, and their speed during transmission, respectively, using the iPerf3 simulator. Specifically, a comparative analysis between the actual transfer time of encrypted and non-encrypted data was investigated. The result showed that transmission times vary for different data sizes that were secured through encryption. Encrypted data had higher transfer time across the network. Additionally, the transfer time across the network was found to be consistent as data size increased with non-encrypted data. Encrypted data, on the other hand, were found to have inconsistent increase in data size with the same set of data sizes due to padding resulting in higher transfer time across thenetwork.

Social, Legal and Economic Implications for the Implementation of an Intelligent Wound Plaster in Outpatient Care

Background:The care of chronic wounds is one of the core tasks of inpatient and outpatient care. The correct timing of changes has a significant impact on the positive course of wound healing. The VulnusMON project developed an intelligent wound plaster to determine the optimum time to change the plaster in hospital. Against the background of implementing the solution also in the outpatient sector, this article focuses on the following research questions: What is the legal framework for wound care in outpatient care? What are the differences in wound care between inpatient and outpatient care? What obstacles and barriers arise for the VulnusMON project when it is implemented in the outpatient sector? Can initial economic estimates be made for the transfer to the outpatient sector?Method:Due to the complexity of the different research questions, a mixed method design was used. The qualitative part of the study includes both focus groups and expert interviews. As part of the quantitative analysis, a data set on outpatient wound care was analyzed (n= 463).Results:In summary, it can be stated that the project VulnusMON and its intelligent wound plaster, which aims to determine the ideal time to change a wound plaster is viewed very positively by the professionals. However, there are a number of barriers that inhibit the potential transfer of the new digital solution to the outpatient setting. From an economic point of view, implementation in the outpatient sector makes sense, as travel times can be reduced. However, the study also points out important social implications, that pose several challenges for the actual transfer of the plaster to the outpatient sector.

Impact of COVID-19 Pandemic on Post-Graduate Medical Education and Training in India: Lessons Learned and Opportunities Offered.

Hands-on or practice-based learning is the foundational objective of postgraduate teaching and training. A skilled and competent postgraduate resident is critical to the country’s health needs and is more relevant in the ongoing COVID-19 pandemic. The postgraduate medical training in India is speciality-specific and based on a structured curriculum and syllabus to achieve precise educational goals and objectives. The impact of this pandemic on postgraduate medical education and training is controversial, challenging, unknown, and far-reaching. The exceptional contagious nature of the virus and country-wide lockdowns have tremendously decreased hospital visiting patients. Abolition of outpatient and inpatient services, disruptions in clinical postings, curtailment of elective operations and procedures have adversely affected the training of residents and fellowship students in India and abroad. Apart from this, research work, mentoring, academic conferences, and workshops that offer learning experiences to these residents have been cancelled or suspended, thus denying them a chance to achieve domain knowledge and enhance their skills. Although this pandemic has offered new learning modes like teleconsultation, videoconferencing, virtual simulations, digital podcasts, etc., how much actual knowledge transfer and skill gain will be achieved is unanswered. Despite this disruption, this pandemic has offered a golden opportunity to relook at the current PG resident education and training programme. The lessons learned from this adversity offer medical universities, medical educators, and regulatory authorities many opportunities to develop a novel and innovative curriculum that enables the current and future residents to achieve the necessary proficiency and competency.

Heat transport enhancement in confined Rayleigh-Bénard convection feels the shape of the container (a) (a)Contribution to the Focus Issue Turbulent Thermal Convection edited by Mahendra Verma and Jörg Schumacher.

Moderate spatial confinement enhances the heat transfer in turbulent Rayleigh-Bénard (RB) convection (Chong K. L. et al., Phys. Rev. Lett., 115 (2015) 264503). Here, by performing direct numerical simulations, we answer the question how the shape of the RB cell affects this enhancement. We compare three different geometries: a box with rectangular base (i.e., stronger confined in one horizontal direction), a box with square base (i.e., equally confined in both horizontal directions), and a cylinder (i.e., symmetrically confined in the radial direction). In all cases the confinement can be described by the same confinement parameter , given as height-over-width aspect ratio. The explored parameter range is , for the Rayleigh number, and a Prandtl number of . We find that both the optimal confinement parameter for maximal heat transfer and the actual heat transfer enhancement strongly depend on the cell geometry. The differences can be explained by the formation of different vertically coherent flow structures within the specific geometries. The enhancement is largest in the cylindrical cell, owing to the formation of a domain-spanning flow structure at the optimal confinement parameter .

Effect of Compressibility on Velocity Profile and Friction Factor of Gaseous Laminar Flows in a Microtube

Abstract Laminar flow of nitrogen gas in a microtube was simulated numerically to obtain velocity profile and Fanning friction factor in a quasi-fully developed region. The numerical procedure based on Arbitrary-Lagrangian-Eulerian method solved two-dimensional compressible momentum and energy equations. The computations were performed for a wide range of Reynolds number in laminar flow regime with adiabatic wall condition. It was found that the velocity profile deviates from the parabola as Mach number increases, and the product of Fanning friction factor and Reynolds number is not a constant but a function of only Mach number. To explain the compressibility effect, a new theoretical flow model which gives the velocity profile of gaseous laminar flows in a microtube was proposed under the assumption of purely axial flow. The theoretical velocity profile is taking radial-direction density change into account, and coincides with the numerically obtained velocity profile. The proposed flow model also shows that the Fanning friction factor of a compressible flow in a microtube is expressed by a quadratic function of Mach number. The coefficient of the Mach squared term is 40% of the numerically obtained correlation. The compressibility effect on friction factor of gaseous laminar flows in a microtube partly results from velocity profile change which must occur to keep the mass velocity profile when density changes in radial direction. The remainder of the compressibility effect can be considered to result from actual mass transfer in the radial direction whose existence was demonstrated by the numerical results.

Photosynthetic characteristics of cotton are enhanced by altering the timing of mulch film removal

BackgroundThe photosynthetic parameters of cotton plants may be modified by the timing of film removal during their growing period. This study was undertaken during 2015–2017 in Xinjiang, China, to determine to what extent the film mulching removal time, 1 and 10 days before the first irrigation and 1 day before the second irrigation after seedling emergence, influenced cotton’s photosynthetic characteristics. The control group (CK) was film-mulched throughout the growth stages.ResultsThe results suggested the following: (1) Removing mulching-film within 50 days since seedling emergence had adverse effects on soil temperature and moisture. (2) Film-removal before the first or second irrigation after emergence improved the net photosynthetic rate in cotton’s later flowering stage and its transpiration rate in mid and later flowering stages while enhancing the actual electron transport rate (ETR) and maximum electron transfer rate (ETRmax) between cotton photosystems I and II. (3) Film-removal treatment also increased cotton plants’ tolerance to high irradiation after emergence, the trend was more pronounced in the early flowering stage in wetter years. (4) Leaf area index (LAI) of cotton was reduced in the film-removal treatment for which the least accumulation of dry matter occurred in a drought year (i.e., 2015). (5) Film removal caused a yield decrease in the dry year (2015), and the earlier the film was removed, the more seriously the yield decreased. Removing mulching film before the second irrigation could increase the yield of XLZ42 in the rainy year (2016) and the normal rainfall year (2017). Early film removal can increase the yield of XLZ45 in the rainy year (2016).ConclusionsCollectively, our study’s experimental results indicate that applying mulch film removal at an appropriate, targeted time after seedling emergence had no adverse effects on soil moisture and temperature, and improved the photosynthetic performance of cotton, thus increased cotton yield and fiber quality, but no significant difference was reached.

Heat Transfer Coefficient Estimation and Performance Evaluation of Shell and Tube Heat Exchanger Using Flue Gas

In the past few decades, water and air were commonly used as working fluid to evaluate shell and tube heat exchanger (STHE) performance. This study was undertaken to estimate heat transfer coefficients and evaluate performance in the pilot-scale twisted tube-based STHE using the flue gas from biomass co-combustion as working fluid. Theoretical calculation along with experimental results were used to calculate the specific heat of flue gas. A simplified model was then developed from the integration of two heat transfer methods to predict the overall heat transfer coefficient without tedious calculation of individual heat transfer coefficients and fouling factors. Performance including water and trailer temperature, heat load, effectiveness, and overall heat transfer coefficient were jointly investigated under variable operating conditions. Results indicated that the specific heat of flue gas from co-combustion ranging between 1.044 and 1.338 kJ/kg·K while specific heat was increased by increasing flue gas temperature and decreasing excess air ratio. The developed mathematical model was validated to have relatively small errors to predict the overall heat transfer coefficient. A flue gas mass flow rate of 61.3–98.8 kg/h, a water flow rate of 13.7–14.1 L/min, and a parallel arrangement of two water-to-air heaters in an empty trailer were found to be optimal conditions for space heating purpose. In addition, a lower poultry litter feeding rate decreased heat loss of flue gas and increased heat gain of water, while a lower water flow rate also provided a lower maximum possible heat transfer rate with a higher actual heat transfer rate to quickly achieve heat equilibrium that ultimately improves the performance. This study demonstrates the possibility of collecting residual heat from the flue gas using the pilot-scale STHE system while outlining a systematic approach and process for evaluating its performance.

PSII Activity Was Inhibited at Flowering Stage with Developing Black Bracts of Oat.

The color of bracts generally turns yellow or black from green during cereal grain development. However, the impact of these phenotypic changes on photosynthetic physiology during black bract formation remains unclear. Two oat cultivars (Avena sativa L.), ‘Triple Crown’ and ‘Qinghai 444’, with yellow and black bracts, respectively, were found to both have green bracts at the heading stage, but started to turn black at the flowering stage and become blackened at the milk stage for ‘Qinghai 444’. Their photosynthetic characteristics were analyzed and compared, and the key genes, proteins and regulatory pathways affecting photosynthetic physiology were determined in ‘Triple Crown’ and ‘Qinghai 444’ bracts. The results show that the actual PSII photochemical efficiency and PSII electron transfer rate of ‘Qinghai 444’ bracts had no significant changes at the heading and milk stages but decreased significantly (p < 0.05) at the flowering stage compared with ‘Triple Crown’. The chlorophyll content decreased, the LHCII involved in the assembly of supercomplexes in the thylakoid membrane was inhibited, and the expression of Lhcb1 and Lhcb5 was downregulated at the flowering stage. During this critical stage, the expression of Bh4 and C4H was upregulated, and the biosynthetic pathway of p-coumaric acid using tyrosine and phenylalanine as precursors was also enhanced. Moreover, the key upregulated genes (CHS, CHI and F3H) of anthocyanin biosynthesis might complement the impaired PSII activity until recovered at the milk stage. These findings provide a new insight into how photosynthesis alters during the process of oat bract color transition to black.

Investigating the performance of the PCM-integrated building envelope on a seasonal basis

BackgroundThe PCM-integrated building envelope has shown significant potential in energy management and heating/cooling loads reduction. However, PCM layer performance highly depends on environmental conditions, configuration and its thermo-physical properties. The right choice of these characteristic features is great of importance since it may cause inverse effects. MethodsSo, in this comprehensive study, the performance of PCM wallboard under realistic sessional weather and solar radiation by considering different values of melting points (22, 24 and 26 °C) is investigated. To capture the solid/liquid interface and liquid fraction, the precise enthalpy-porous model, as well as the actual heat transfer chain consisting of radiation, convection and conduction from the environment to the room ambient, are implemented. Significant findingsThe results showed that the PCM layer is not always advantageous and more than 5% negative impact on energy loss is observed. So, the performance is highly dependent on other key factors including the environmental conditions and its volumetric amount. Also, the existence of optimum values for PCM layer thickness regarding the costs and wall density is observed for different types of PCM. The effect of the melting point on energy-saving is another significant parameter that has shown a considerable impact on appropriate PCM selection for specific regional conditions.

Experimental assessment of convective and radiative heat transfer coefficients for various clothing ensembles.

The convective and radiative heat transfer coefficients of clothing are important parameters for human thermoregulation and comfort models. Many researchers have studied convective and radiative heat transfer coefficients of the naked human body. However, there is limited information on convective and radiative heat transfer coefficients for the clothed human body. Therefore, this study aims to confirm whether the convective and radiative heat transfer coefficients vary with different clothing ensembles in addition to clarifying how the difference in clothing heat transfer coefficients affects the prediction of thermal comfort index, such as the predicted mean vote (PMV) index. The convective and radiative heat transfer coefficients for eight sets of clothing ensembles were measured through a manikin experiment. The results demonstrated that (1) the largest difference between convective heat transfer coefficients for various clothing ensembles was 32%, and (2) PMV values differed between the clothing ensembles with the largest value being approximately 0.2, which corresponds nearly 1 °C change in the indoor temperature. Therefore, it is necessary to consider the actual clothing convective heat transfer coefficient for the precise prediction of thermal comfort.

Insecurity Early Warning for Large Scale Hybrid AC/DC Grids Based on Decision Tree and Semi-Supervised Deep Learning

Fast insecurity early warning is the key technique to resist the dynamic insecurity risk, which becomes intractable due to the strong nonlinearity of hybrid AC/DC grids and the high uncertainty of wind generation. Considering dynamic security constraints and wind power uncertainty, this paper presents an insecurity early warning method based on decision tree (DT) and semi-supervised deep learning. First, semi-supervised deep learning is deployed to estimate the dynamic security limit of the critical interface of hybrid AC/DC grids. The system security is assessed by comparing the actual power transfer of the critical interface with the security limit. Then, operating conditions (OCs) are ranked into different insecure levels according to the type of preventive control actions that is needed to ensure the system security. Finally, oblique DT is utilized to identify insecurity classification boundaries in the wind power injection space. Insecure OC sets are constructed based on these classification boundaries. Simulation results of the real-life Jiangsu-Shanghai interconnected grid in east China demonstrate that the proposed method can fast construct the insecure OC sets corresponding to different insecure levels.

An investigation of the second law performance for a condenser used in 210 MW thermal power station

This work presents a case study of thermodynamic performance of a condenser used in a 210 MW thermal power station at Mejia in West Bengal, India. The analysis involves an improvement of actual overall heat transfer coefficient by varying tube materials and fouling resistance. Exergy Destruction Factor (EDF) is introduced to quantify the percentage of exergy loss from the condenser wall. From this study, it is revealed that the second law performance of the condenser increases with the increase in thermal conductivity of the tube materials, decreases with the increase in fouling resistance and decreases with the increase in condenser pressure at the turbine outlet. The actual overall heat transfer coefficient can be increased up to 6% by selecting better conducting tube materials. While the EDF decreases with the increase in cooling water temperature rise and increases with the increase in cooling water inlet temperature, EDF is found to decrease with the increased cooling water mass flow rate.

Correlation approach for the Push-Out and full-size bending short-term performances of timber-to-timber slabs with Self-Tapping Screws

Self-Tapping Screws (STSs) are commonly used to realize many geometrical configurations for connections that are characterized by enhanced stiffness and load-carrying capacity. The analysis of STS joints and composite systems, however, usually requires designers to account for several aspects in their actual load transfer mechanisms, and most of them require refined calculation tools.In this paper, an extended Finite Element (FE) investigation is proposed for timber-to-timber slabs with STS joints, based on full 3D brick models inclusive of Cohesive Zone Modelling (CZM) techniques and damage constitutive laws for the materials in use. The final goal of the study takes advantage of the global and local performance assessment of a selection of STS joints, with careful consideration for their response under a conventional Push-Out (PO) test setup or a full-size bending configuration. As shown, major FE outcomes are discussed to elaborate a design procedure that can be developed on the base of correlation coefficients for maximum force and stiffness calculations in a given slab and loading condition. Major effects due to variable loading configurations are in fact explored at the screw level. Further, geometrically simplified spring-based FE models, that hardly capture the complex behaviour of the examined systems but are largely used in design practice, are presented in comparison to refined FE approaches and literature efforts. As shown, the variation of maximum force and stiffness parameters for STSs is emphasized in the paper for a selection of configurations, and fitting curves are proposed to estimate the STS performance along a given full-size slab, thus suggesting the feasibility and possible generalization of the procedure.

Truck to door assignment in a shared cross-dock under uncertainty

This paper addresses the optimization of the truck to door assignment problem in cross-docks. It defines a new form of horizontal collaboration between suppliers by sharing the platform’s resources to enhance service level and reduce economical costs. Moreover, this study proposes to solve the problem by considering an uncertain transfer time, that is frequently observed in real-world cross-docks. Due to imprecise arrival time of trucks, equipment breakdown, or workload variation, etc, the actual transfer time tends to be shorter or longer than the prefixed one. This uncertainty is modeled as a triangular fuzzy number then a Fuzzy Chance Programming model has been proposed to solve the problem using possibilistic measures. The efficiency and robustness of both (deterministic and fuzzy) proposed models are tested empirically and obtained results confirm the positive effect of collaboration and uncertainty handling.