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Ketosis is a common nutritional metabolic disease during the perinatal period in dairy cows. Although various risk factors have been identified, the molecular mechanism underlying ketosis remains elusive. In this study, subcutaneous white adipose tissue (sWAT) was biopsied for transcriptome sequencing on 10 Holstein cows with type II ketosis [blood β-hydroxybutyric acid (BHB) >1.4 mmol/L; Ket group] and another 10 cows without type II ketosis (BHB ≤1.4 mmol/L; Nket group) at d 10 after calving. Serum concentrations of nonesterified fatty acids (NEFA) and BHB, as indicators of excessive fat mobilization and circulating ketone bodies, respectively, were significantly higher in the Ket group than in the Nket group. Aspartate transaminase (AST) and total bilirubin (TBIL), as indicators of liver damage, were higher in the Ket group than in the Nket group. Weighted gene co-expression network analysis (WGCNA) of the sWAT transcriptome revealed modules significantly correlated with serum BHB, NEFA, AST, TBIL, and total cholesterol. The genes in these modules were enriched in the regulation of the lipid biosynthesis process. Neurotrophic tyrosine kinase receptor type 2 (NTRK2) was identified as the key hub gene by intramodular connectivity, gene significance, and module membership. Quantitative reverse transcription PCR analyses for these samples, as well as a set of independent samples, validated the downregulation of NTRK2 expression in the sWAT of dairy cows with type II ketosis. NTRK2 encodes tyrosine protein kinase receptor B (TrkB), which is a high-affinity receptor for brain-derived neurotrophic factor, suggesting that abnormal lipid mobilization in cows with type II ketosis might be associated with impaired central nervous system regulation of adipose tissue metabolism, providing a novel insight into the pathogenesis underlying type II ketosis in dairy cows. [ABSTRACT FROM AUTHOR]

• A novel model for classifying Autism Spectrum Disorder (ASD) is proposed, which employs self-attention to capture the association among remote brain regions. The model consists of a multi-head self-attention encoder as the primary component, with Multilayer Perceptron (MLP) used for classification assistance. • An effective method called sliding window analysis is adopted to alleviate overfitting, which can help the model extract more useful information for classification from approximate samples, resulting in significantly improved performance in all metrics. • The results of the study show significant differences in functional connectivity in brain regions (including the middle frontal gyrus, superior frontal gyrus, and hippocampus) in ASD patients compared with normal subjects, consistent with previous studies. The static functional connectivity (SFC) networks based on resting-state functional MRI (rs-fMRI) typically focus on local correlations between specific brain regions, neglecting the broader connections across the entire brain. This limitation can hinder the accurate diagnosis of neurological conditions such as Autism Spectrum Disorder (ASD). This study aimed to overcome this limitation and improve ASD dentification accuracy. We propose a self-attention based ASD classification model. Employing sliding windows with longer window width, we locally sample the original data to increase the training sample size, thereby alleviating model overfitting. Subsequently, we introduce the multi-head self-attention mechanism, forming a deep model composed of stacked attention blocks. This ensure the capture of not only local correlations but also overall brain network features, significantly enhancing the classification accuracy of ASD. Our proposed model was evaluated on fMRI data from the ABIDE NYU site. Experimental results demonstrated an accuracy of 81.47%, a sensitivity of 83.8%, and a specificity of 80.16%. Compared to other methods in the literature, our approach exhibited superior accuracy. Furthermore, the experiments revealed that the biomarkers used by the model for classification are primarily distributed across brain regions such as the superior frontal gyrus, middle frontal gyrus, and hippocampus, aligning with previous research findings. The sliding window method effectively enriches the dataset and alleviates overfitting. Simultaneously, the suggested model, which relies on self-attention mechanisms, has the ability to effectively extract global information from brain regions, providing a viable method to improve the accuracy of ASD identification. [ABSTRACT FROM AUTHOR]

Abstract To promote the application of bedroom TAC to a larger region, task/ambient air conditioning (TAC) system was applied to different climate zones in China. In this study, China as a typical country which has a very large area and significantly different climate zones, was selected as the investigated country. Firstly, five cities in different climate zones were selected. Secondly, the CFD study was carried out on the bedroom TAC using the environmental parameters. Thirdly, predictive models of energy consumption were established using RSM method. Afterwards, the energy performance of the TAC system in different cities were predicted and analyzed. The results showed that the energy consumption in the typical day was from 0 kJ in Kunming to 4588.30 kJ in Shanghai. [ABSTRACT FROM AUTHOR]

Abstract For an air source heat pump (ASHP) unit, uneven frost distribution would result in mal-defrosting, or adversely degrade system defrosting efficiency. Previous investigations demonstrated that, for an ASHP unit with a multi-circuit outdoor coil, when the frosting evenness value (FEV) on its surface of outdoor coil is higher, the defrosting efficiency would also be higher. On the other hand, as reported, the downwards flowing melted frost during defrosting would also play negative effects on defrosting performance. Although the comprehensive influence of the two factors, uneven frost distribution and the downwards flowing melted frost, had been experimentally investigated, the influence of uneven frost distribution or the FEV on negative effect of downwards flowing melted frost was still unknown. As a fundamental and interesting problem, it is meaningful to be explored. It was therefore quantitatively analyzed here basing on six experimental cases. Water collecting trays were used to take away the melted frost during defrosting in three cases, and the other three ones without trays installed stood for the traditional status. Meanwhile, their FEVs of two groups were separately adjusted to be at three different levels. Results clearly showed the positive effects of increasing FEV and taking away the melted frost on system defrosting efficiency. After the melted frost was taken away, the FEV effects was increased. The increase of defrosting efficiency seems unchanged, but the reduction of defrosting duration was obviously increased from 17 s to 22 s. However, the differences of defrosting duration and efficiency changed were too small when melted frost was locally drained or not. More experimental cases with lower FEVs should be carried out. [ABSTRACT FROM AUTHOR]

Abstract In applications, the defrosting operation of an air source heat pump (ASHP) unit is always started with a pre-set time, corresponding to a fixed mass of frost accumulation, and thus resulting in series of mal-defrosting phenomenon. The exact defrosting initiation time is hard to be quantitatively given due to the dynamic and uneven frosting conditions. For an ASHP unit with a multi-circuit outdoor coil, when the melted frost was locally drained during defrosting, the optimization of start defrosting control strategy becomes more complicated. Here, this fundamental problem was experimentally investigated, with frost evenly distributed on the surface of the outdoor coil at the start of defrosting. Defrosting performance of the experimental ASHP unit at different frost accumulations were then comparatively analyzed, with the melted frost local drainage specially considered. These physical parameters include the temperature of tube surface and melted frost, compressor suction and discharge pressures and their difference, thermal energy taken from indoor air and electricity inputs on compressor and fans during defrosting, etc. Results suggest that, the defrosting efficiency reached its peak at 46.05% when frost accumulation was at 930 g. After the melted frost was locally taken away during defrosting, it reached its peak at 51.80% when frost accumulation was at 933 g. Thus, the time-based start defrosting control strategy was demonstrated to be fundamentally optimized with this method. Contributions of this study could be used for adjusting the control strategy of ASHP units, which are valuable to energy saving in industrial applications. [ABSTRACT FROM AUTHOR]

Abstract Task/ambient air conditioning (TAC) system is reported to be an energy efficient technology with available methods to control thermal comfortable level for sleeping environments. However, the variation of indoor thermal environment will directly affect the performance of the TAC system, especially the set of operation parameters. Therefore, an optimization study on the TAC system operation considering the effects of envelope thermal load was carried out in this paper. Firstly, a full factorial design method was used to construct the models of the energy consumption and thermal comfort. Secondly, comfort lines were obtained to calculate the optimum operating parameters at which the energy consumption was at the lowest. Finally, the energy consumption at the optimum status was calculated. [ABSTRACT FROM AUTHOR]

As a common physical phenomenon, frost deposition is inevitable and always has significant negative effects in many industry fields, such as aerospace, aviation, and HVAC&R, etc. To accurately predict and control a frosting-defrosting cycle, the frost layer thickness should be firstly obtained, which is the most fundamental and important parameter. During the last several decades, frost layer thickness measurement methods and different correlations were widely reported, basing on experimental, semi-empirical, theoretical, and numerical approaches. To provide an overview of the analytical tools for scholars, researchers, product developers, and policy designers, a review and comparative analysis of frost layer thickness studies were conducted. The existing gaps in the frost research are identified and recommendations are made as authors’ outlooks in final conclusions. [ABSTRACT FROM AUTHOR]

It is noticed that the building envelope thermal load affects the indoor thermal environment and operation of the air conditioning system due to the heat transfer through the envelope. The variation of indoor thermal environment will directly affect the performance of the air conditioning system. To weaken even eliminate the effects of envelope thermal load, PCM was integrated in the building envelope. The effects of PCM on variation of return air temperature in a bedroom in a coastal city was studied and compared with the traditional building envelope. The characteristics of PCM, like the melting temperature and amount of PCM were also investigated. [ABSTRACT FROM AUTHOR]

Task/ambient air conditioning (TAC) system is reported to be an energy efficient technology with available methods to control thermal comfortable level for sleeping environments. However, for real application the varied envelope thermal load should be considered. To determine the optimum operation under different envelope thermal load, an optimization of the TAC system operation was carried out in this study. A multi-objective optimization approach named TOPSIS method was used to evaluate the integrated performance of the TAC system. Finally, the ranking of the selected study cases was obtained and the optimum operation was achieved. [ABSTRACT FROM AUTHOR]

Phase change materials have found wide applications in recent decades in different fields due to their good thermal performance in energy systems. These fields include green building envelope, industry thermal energy storage, battery thermal management, power peak regulation, smart thermal fibers, and bio-medical, etc. These applications are mainly limited by their phase change temperatures and latent heat values, which makes topics around characteristic improvement for binary organic phase change materials very hot. Thus, the thermal stability study on organic binary phase change materials used in thermal energy storage applications is fundamental and meaningful. In this study, an experimental investigation on thermal stability of three types of organic binary PCMs was conducted, which are very frequently-used in building services and industry waste energy recovery. As concluded, in view of phase change temperature and heat of fusion, Capric acid & Myristic acid has the best thermal stability and reliability performance among the mentioned three composite materials. This study makes contributions to phase change materials choosing and system life-span design optimization. [ABSTRACT FROM AUTHOR]

Sleep can help people overcome physical and psychological fatigue, and sleep is very important to one’s memory. The total insulation value of a bedding system is a significant factor, which affects remarkably the thermal comfort for sleeping environments. This paper reports a study on the effects of different bedding systems on thermal comfort to quantify the sensitivity coefficient used for calculating PMV in sleeping environments. Firstly, the experimental materials and methods were described in detail. Then, the experimental results and their analysis of the effects of different bedding systems on thermal comfort, in terms of skin temperatures and thermal sensations, are reported. Finally, the sensitivity coefficient used for calculating PMV in sleeping environments is regressed and further discussions are presented. The experimental results showed that the bedding systems affected remarkably mean skin temperatures, and especially the local skin temperature at forearm posterior. The relationship between the local skin temperature at forearm posterior and thermal sensation of subjects was established, suggesting that the skin temperatures was an important factor that influences the human’s sensation during sleep. A sensitivity coefficient with a higher value of 0.1733 was regressed by the experimental results, and can be used for calculating PMV in sleeping environment. [ABSTRACT FROM AUTHOR]

There has been an increasing concern on thermal comfort in sleeping environments and its associated energy use in the past few years. To improve the thermal environment and reduce energy use of air conditioning in bedrooms, task/ambient air conditioning (TAC) can be applied and was studied previously. Due to the variation of the envelope thermal loads in a bedroom during night, it is necessary to study the thermal environment inside the bedroom and the energy use of a TAC system for the bedroom at varying envelope thermal loads. Therefore, this paper reports on a numerical study on a TAC system applied to a bedroom with different envelope heat gains. PMV and EUC (energy utilization coefficient) values were evaluated, respectively. The study results indicated that when envelope thermal loads was higher, the advantage of the TAC system in energy saving was greater for the same thermal comfort level. However, it should be noted that a higher envelope thermal load could also resulted in the non-uniformity in air flow and air temperature distributions, leading to a possible uncomfortable micro environment. [ABSTRACT FROM AUTHOR]

It was revealed in a previous related study that for an air conditioning (A/C) system used in a sleeping environment, the height of its supply air outlet would significantly affect its ventilation performance in terms of effectiveness. To further examine the underlying reasons of the differences in ventilation performance, the air flow field, distributions of mean age of air, air change efficiency and distributions of CO 2 concentrations inside an experimental bedroom were numerically studied using CFD method under five different settings, where its supply air outlet was positioned at 5 different heights. The study results suggested that positing a supply air outlet at a lower level was effective in both saving energy and removing the exhaled CO 2 in a breathing zone, and when a supply outlet was positioned at a higher level, less CO 2 was removed from the region near the mouth of a sleeper. [ABSTRACT FROM AUTHOR]

A bed-based TAC system applied to sleeping environments has been developed and its performances experimentally and numerically studied, and the study results are reported in this paper. Firstly, a detailed description of an experimental rig for the bed-based TAC system at two settings is presented with a return air inlet on the wall (Setting 1) and with a return air plenum and inlet placed under the bed (Setting 2). Secondly, the experimental results on the operating performances of the bed-based TAC system at the two settings in terms of thermal environmental control and energy saving are analyzed and reported. Thirdly, to supplement the experimental study for a more detailed analysis on air temperature and flow fields, a follow-up numerical study was carried out and is reported. Both the experimental and numerical study results suggested that the bed-based TAC system at Setting 2 performed better in controlling thermal environment in an occupied zone but with a relatively poorer energy saving performance, as compared to that at Setting 1. [ABSTRACT FROM AUTHOR]

When the surface temperature of the outdoor coil in an air source heat pump (ASHP) unit is below both the air dew point and freezing point of water, frost can be formed and accumulated over the surface of the outdoor coil, which is usually of multi-circuit structure in order to minimize its refrigerant pressure loss and enhance the heat transfer between refrigerant and ambient air. However, frosting adversely affects the operational performance and hence the energy efficiency of the ASHP unit, therefore periodic defrosting is necessary. Currently, the most widely standard defrosting method used for ASHP units is reverse cycle defrosting. A previous related study has suggested that during reverse cycle defrosting, downwards flowing of melted frost due to gravity over a vertical multi-circuit outdoor coil in an ASHP unit could deteriorate defrosting performance, by using more energy for defrosting and prolonging a defrosting process. If however an outdoor coil can be horizontally installed, the flow path for melted frost over coil surface can be shortened, and a better defrosting performance expected. In this paper, therefore, an experimental study on performance during reverse cycle defrosting of an ASHP unit having a horizontal three-circuit outdoor coil has been carried out. Firstly, a detailed description of the ASHP unit is presented. This is followed by reporting the experimental results. Finally, a comparative and quantitative analysis is given. [ABSTRACT FROM AUTHOR]

Abstract: This paper considers the two-point boundary value problem of stochastic differential equation with the following form:The sufficient and necessary conditions are given for the existence of the adapted solutions. In the simple case that f(t, X t )= f t , the solution can be obtained by introducing a control term f t , extending the solution from X t to (X t , f t ), and constructing a process sequence. All the results obtained are compared with those related to the eigenvalue problems, and the “martingale approach” solution proposed by Pardoux and Peng for backward stochastic differential equations. [Copyright &y& Elsevier]

The fabric filtration process is divided into three stages, i.e. depth filtration, transition filtration and surface filtration. A new model is proposed to describe the three stages under both virgin and regeneration conditions. The concept of an interface dust layer is introduced to predict the transition from the depth filtration stage to the transition filtration stage. The transition filtration stage due to the non-uniform accumulation of residual dust on a filter is characterized by two parameters — the surface cleaning fraction, f, and the residual dust load on the uncleaned surface, Wu0. It is found that f decreases and Wu0 increases with the number of filtration cycles. This result suggests that both the fraction of uncleaned surface and the thickness of dust cake on the uncleaned surface increase with the number of filtration cycles. The present model successfully describes the change in pressure drop during the filtration cycles using the parameters. [ABSTRACT FROM AUTHOR]

The VDI type 1 rig and JIS rig are two of the major testing rigs for cleanable fabric filters. We measured the filter performance using these rigs and compared the results in order to characterize the two testing rigs. The filter performance tests showed that the filter cleaning efficiency measured with the VDI type 1 rig is higher than that with the JIS rig. The difference in cleaning efficiency led to the different residual pressure drop after the aging of the filter. The difference in filter performance measured by the two rigs can be minimized by modifying the aging condition, i.e. either reducing the number of filtration cycles during the aging with the JIS rig or increasing it with the VDI type 1 rig so as to give the same residual pressure drop after aging. Furthermore, it is found that there is an optimum filtration cycle time to grow the residual pressure drop during the filter aging in order to minimize the time period of filter aging. [ABSTRACT FROM AUTHOR]

• Spray falling film of oily wastewater over a horizontal tube was investigated. • VOF model was used to simulate the gas-liquid falling film flow. • The non-uniform film flow, temperature and thickness distributions were analyzed. • The non-uniform heat transfer properties were quantitatively investigated. • The effects of oil content, spray density and tube diameter were studied. Recently, the spray heat exchanger became an important technology in a sewage source heat pump (SSHP) to recover thermal energy from oily wastewater. Hence, it's necessary to study the heat transfer properties and its enhancements. In this paper, a numerical model with VOF method was established to study the oily wastewater spray falling film over a horizontal tube. The flow field, falling film distribution and temperature distribution and heat transfer coefficient were investigated, and the non-uniformity of flow, temperature and heat transfer were further analyzed. Regions of low level film thickness were found around tube suggesting the non-uniform axial and circumferential distribution, corresponding to low film temperature regions. The non-uniformity of heat transfer coefficient at different circumferential angles was evaluated showing severe non-uniformity in impingement and departure regions due to the intense impinging of falling wastewater at the top and instability of dropping flow at the bottom. Thereafter, the influence of oil content, spray density and tube diameter were studied. The increase in oil content led the flow pattern changed from sheet flow to column-sheet flow due to increase in viscosity, resulting to non-uniformity increase from 0.15 to 0.19. Compared to tube diameter of 25.4 mm, the 12.7 mm tube accelerated flow downstream, therefore, the non-uniformity at the top was weakened to 0.13 and the downstream non-uniformity was strengthened to 0.19. The higher spray density of 0.262 kg/m∙s reduced the negative effect of viscosity, enhanced the flow velocity and weakened the non-uniformity at the top. However, the increase in flow velocity raised the flow instability in downstream suggesting higher non-uniformity. [ABSTRACT FROM AUTHOR]