Rapid growth of the aged population has caused an immense increase in the demand for healthcare services. Generally, the elderly are more prone to health problems compared to other age groups. With ...effective monitoring and alarm systems, the adverse effects of unpredictable events such as sudden illnesses, falls, and so on can be ameliorated to some extent. Recently, advances in wearable and sensor technologies have improved the prospects of these service systems for assisting elderly people. In this article, we review state-of-the-art wearable technologies that can be used for elderly care. These technologies are categorized into three types: indoor positioning, activity recognition and real time vital sign monitoring. Positioning is the process of accurate localization and is particularly important for elderly people so that they can be found in a timely manner. Activity recognition not only helps ensure that sudden events (e.g., falls) will raise alarms but also functions as a feasible way to guide people's activities so that they avoid dangerous behaviors. Since most elderly people suffer from age-related problems, some vital signs that can be monitored comfortably and continuously via existing techniques are also summarized. Finally, we discussed a series of considerations and future trends with regard to the construction of "smart clothing" system.
Ammonia (NH3) can be used as carbon-free alternative fuel for modern energy and transportation systems. Co-firing NH3 with syngas can overcome the high ignition energy and low burning velocities of ...pure NH3 flames on the one hand, while regarding the characteristics of syngas on the other hand, this strategy may have low-emission potential in real application, and a corresponding research can be helpful for validating or developing NH3 co-firing mechanisms with more complex fuels. The present study experimentally investigated laminar burning velocities of NH3/syngas/air flames at atmospheric pressure and 298 K using the heat flux method. Two types of syngas components were used, i.e., SYN_A: 5 vol% H2 + 95 vol% CO and SYN_B: 50 vol% H2 + 50 vol% CO, and the measured conditions cover wide ranges of mixing ratios and equivalence ratios. Several literature kinetic mechanisms were tested and a new mechanism was proposed. Results calculated by the present mechanism agree well with experimental data of the burning velocities and the ignition delay times of NH3, NH3/H2, NH3/CO, and NH3/syngas flames at various mixing ratios, equivalence ratios, and pressures. The present mechanism also reproduces the trend of NOx emission characteristic in literature. Detailed kinetic analyses using the present mechanism were carried out, showing the NH3 oxidation processes in NH3/syngas/air flames and the most rate-limiting reactions for predicting the laminar burning velocities. Important reactions with different rate parameters from different sources were labeled, which could be helpful for future organization or optimization of NH3 kinetic mechanisms.
•Frost retarding and defrosting studies published in 2000–2017 are reviewed.•Two types of 12 frost retarding measures are classified and analyzed.•5 defrosting methods and 6 improvement methods are ...summarized.•Initiation and termination control strategies of defrosting operation are presented.•The existing gaps in the research works are identified and classified as 5 aspects.
Air source heat pump (ASHP) units have found worldwide applications due to their advantages of high energy efficient and environmental friendly. Frost deposition and accumulation on the surface of the outdoor coil in an ASHP unit is inevitable and always play significant negative effects. To accurately predict and control a frosting-defrosting cycle, the interrelated heat, mass, and momentum transport phenomena within frost, melted frost and at the air-frost interface, a moving boundary condition, should be clearly understood. This review paper focuses on the developments in frost retarding and defrosting investigations for ASHP units from 2000 to 2017. 12 frost retarding measures and 5 defrosting methods are firstly introduced, followed by 6 typical system optimization methods during reverse cycle defrosting. Alternative control strategies to start and end a defrosting operation are thereby presented. Basing on previous analysis, the existing gaps in the research works on frost retarding and defrosting are identified, and recommendations are finally offered as per the viewpoint of the present authors. This comprehensive and systematic review around an entire frosting-defrosting cycle might provide an overview of the analytical tools for scholars, researchers, product developers, and policy makers, and shed new light on the designing and performance optimization of ASHP units.
Bifunctional Bi12O17Cl2/MIL-100(Fe) composite (BMx) was firstly constructed via facile ball-milling method. The optimal BM200 was highly efficient for Cr(VI) sequestration and activation of ...persulfate (PS) for bisphenol A (BPA) decomposition under white light illumination, which was much more remarkable than the pristine MIL-100(Fe) and Bi12O17Cl2, respectively. Furthermore, the photocatalytic reduction efficiency can be significantly improved via the addition of some green small organic acids (SOAs). As well, the BPA degradation can be achieved over an extensive initial pH range of 3.0–11.0. When the PS concentration increased to more than 2.0 mM, the BPA degradation efficiency decreased due to the SO4−• self-scavenging effect. It was also found that the co-existence of inorganic anions like H2PO4−, HCO3−, SO42−, Cl− and NO3− could decelerate the BPA degradation. The excellent photocatalytic Cr(VI) reduction and persulfate activation performances originated from both MIL-100(Fe) with excellent PS activation ability and Bi12O17Cl2 with a favorable band position, which not only enabled the efficient separation of charges but also accelerated the formation of SO4−• radicals. The BM200 displayed prominent stability and recyclability. More importantly, the credible degradation pathway was proposed based on UHPLC-MS analysis and DFT calculation. This research revealed that the Fe-based MOFs/bismuth-rich bismuth oxyhalides (BixOyXz, X = Cl, Br and I) composites possessed great potential in wastewater remediation.
Bismuth-rich Bi12O17Cl2/MIL-100(Fe) composites were firstly fabricated to achieve efficient Cr(VI) sequestration and BPA degradation with the addition of persulfate PS under white light illumination. Display omitted
•Bi12O17Cl2/MIL-100(Fe) (BMx) was constructed by facile ball-milling method.•BM200 composite was an efficient photocatalyst for Cr(VI) and BPA cleanup.•BM200/light/PS system exhibited synergistic effect in BPA degradation.•BM200 showed good reusability and high stability.•DFT calculation with high Fukui index interpreted the easy-attacking sites on BPA.
A gas sensor based on the In2O3–rGO nanocomposites was successfully fabricated, which exhibited excellent selectivity, high response, relatively short response and recovery times for detection of NO2 ...at room temperature.
In this paper, well-controlled synthesis of In2O3-reduced graphene oxide (In2O3–rGO) nanocomposites by hydrothermal method was demonstrated. The structural, morphological, chemical composition studies of the In2O3–rGO nanocomposites were carried out, evidencing a homogeneous dispersion of In2O3 on the rGO nanosheets. The sensor based on the In2O3–rGO nanocomposites exhibited excellent selectivity, high response, and relatively short response and recovery time for detection of NO2 at room temperature. The excellent sensing properties were resulted from the composition and structure advantages of the In2O3–rGO nanocomposites.
The purpose of this paper is first to introduce the notation of matrix intuitionistic fuzzy normed spaces, and then by virtue of this notation to study the Hyers-Ulam stability results concerning the ...mixed type additive-quadratic functional equation
<disp-formula> <tex-math id="FE1"> \begin{document}$ 2kf(x+ky)+f(kx+y) = k(1-s+k+ks+2k^{2})f(x+y)\\+k(1-s-3k+ks+2k^{2})f(x-y) \\ +2kf(kx)+2k(s+k-ks-2k^{2})f(x)+2(1-k-s)f(ky)+2ksf(y)$\end{document} </tex-math></disp-formula>
in the setting of matrix intuitionistic fuzzy normed spaces by applying two different methods, where $ s $ is a parameter, $ k > 1 $ and $ s\neq 1-2k $. Moreover, the interdisciplinary relation between the theory of matrix intuitionistic fuzzy normed spaces and the theory of functional equations are also presented in this paper.
The home energy management system (HEMS) plays an important role in enabling residential customers to participate in demand response (DR) programs autonomously via appliance-level dispatch with smart ...plugs, and the flexibility analysis could help the HEMS to dispatch appliances efficiently without harming user's comfort level. This paper presents a bottom-up method to obtain the flexibility of appliances. With the use of smart plugs in the HEMS, the type of the appliance attached to each smart plug is inferred with consideration of measurement uncertainty as well as user behavior. Then, the flexibility of an appliance is analyzed based on the extrapolated power consumption of the appliance as well as the owner's usage behavior. In the case study, the types of appliances recognized for individual smart plugs as well as the corresponding flexibilities are used as reference for appliance dispatching in the HEMS under various DR applications. The case study demonstrates the performance of the proposed appliance load monitoring method and the application of the proposed flexibility analysis.
•Afield test was carried out for deep boreholes with 2000m depth.•The performance of deep borehole ground source heat pump was evaluated.•A 3D numerical model according to geological structure was ...developed.•The simulation results showed a good agreement with the field test data.•The impacts of inlet velocity, inlet temperature and flow pattern were examined.
Deep borehole ground source heat pump (DBGSHP) is a new type of heat pump heating system which extracts deep geothermal energy through heat exchange and can be applied for space heating in winter. To date, the development of deep borehole heat exchangers (BHEs) is limited to the cognized structure design and there is a lack of the experimental studies. This paper presents the investigation of the heat transfer characteristics of the heat exchanger of a DBGSHP heating system through both field test and numerical simulation. A field test was first carried out based on the DBGSHP implemented in a demonstration project. A numerical model was then developed to facilitate the evaluation of the heat extraction capacity and the outlet temperature of the coaxial deep BHEs. Based on the numerical model developed, a sensitivity study was further performed to examine the effect of the primary parameters including the inlet velocity, inlet temperature, flow pattern (one was that the circulating fluid flowed from the inner pipe to the annular space and the other was that the circulating fluid flowed from the annular space to the inner pipe) and pipe diameter on the performance of deep BHE. The results from the field test indicated that the average heat transfer capacity of each single borehole, the average COP of the heat pump unit and the DBGSHP heating system COP were 286.4kW, 6.4 and 4.6, respectively. The simulation results matched well with the field test data, and showed that the inlet fluid velocity between 0.3m/s and 0.7m/s as well as the circulating fluid flowed from the annular space to the inner pipe can result in a better performance for the system of concern. The results from this study could be used as a reference basis for optimal design of coaxial deep BHE and to promote the utilization of deep geothermal energy.
In this paper, we investigate the generalized Hyers-Ulam stability of the following mixed type quadratic-cubic functional equation \begin{align*} 2f(2x+y)+2f(2x-y) = ...4f(x+y)+4f(x-y)+4f(2x)+f(2y)-8f(x)-8f(y) \end{align*} in non-Archimedean $(n,\beta)$-normed spaces.
Cardiac hypertrophy is an adaptive response of the heart to increased workload induced by various physiological or pathological stimuli. It is a common pathological process in multiple cardiovascular ...diseases, and it ultimately leads to heart failure. The development of cardiac hypertrophy is accompanied by gene expression reprogramming, a process that is largely dependent on epigenetic regulation. Histone modifications such as methylation and acetylation are dynamically regulated under cardiac stress. These consequently contribute to the pathogenesis of cardiac hypertrophy via compensatory or maladaptive transcriptome reprogramming. Histone methylation and acetylation modifiers play crucial roles in epigenetic remodeling during the pathogenesis of cardiac hypertrophy. Regulation of histone methylation and acetylation modifiers serves as a bridge between signal transduction and downstream gene reprogramming. Exploring the role of histone modifiers in cardiac hypertrophy provides novel therapeutic strategies to treat cardiac hypertrophy and heart failure. In this review, we summarize the recent advancements in functional histone methylation and acetylation modifiers in cardiac hypertrophy, with an emphasis on the underlying mechanisms and the therapeutic potential.
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•Histone methylation and acetylation are dynamically involved in cardiac hypertrophy.•Histone modifiers coordinate to establish a hypertrophic transcriptome landscape.•Targeting histone methylation and acetylation is of promising therapeutical potential.•Technological advancement will help decode the histone code underlying cardiac hypertrophy.
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