Numerical Analysis on Temperature Distribution in a Single Cell of PEFC Operated at Higher Temperature by1D Heat Transfer Model and 3D Multi-Physics Simulation Model

This study is to understand the impact of operating conditions, especially initial operation temperature (Tini) which is set in a high temperature range, on the temperature profile of the interface between the polymer electrolyte membrane (PEM) and the catalyst layer at the cathode (i.e., the reaction surface) in a single cell of polymer electrolyte fuel cell (PEFC). A 1D multi-plate heat transfer model based on the temperature data of the separator measured using the thermograph in a power generation experiment was developed to evaluate the reaction surface temperature (Treact). In addition, to validate the proposed heat transfer model, Treact obtained from the model was compared with that from the 3D numerical simulation using CFD software COMSOL Multiphysics which solves the continuity equation, Brinkman equation, Maxwell-Stefan equation, Butler-Volmer equation as well as heat transfer equation. As a result, the temperature gap between the results obtained by 1D heat transfer model and those obtained by 3D numerical simulation is below approximately 0.5 K. The simulation results show the change in the molar concentration of O2 and H2O from the inlet to the outlet is more even with the increase in Tini due to the lower performance of O2 reduction reaction. The change in the current density from the inlet to the outlet is more even with the increase in Tini and the value of current density is smaller with the increase in Tini due to the increase in ohmic over-potential and concentration over-potential. It is revealed that the change in Treact from the inlet to the outlet is more even with the increase in Tini irrespective of heat transfer model. This is because the generated heat from the power generation is lower with the increase in Tini due to the lower performance of O2 reduction reaction.

Research on Hydrodynamics Model Test for Deepsea Open-Framed Remotely Operated Vehicle

This paper presents the features of newly designed hydrodynamics test for the scaled model of 4500 m deepsea open-framed remotely operated vehicle （ROV）, which is being researched and developed by Shanghai Jiao Tong University. Accurate hydrodynamics coefficients measurement and spatial modeling of ROV are significant for the maneuverability and control algorithm. The scaled model of ROV was constructed by 1：1.6. Hydrodynamics coefficients were measured through VPMM and LAHPMM towing test. And dynamics model was derived as a set of equations, describing nonlinear and coupled 5-DOF spatial motions. Rotation control motion was simulated to verify spatial model proposed. Research and application of hydrodynamics coefficients are expected to enable ROV to overcome uncertainty and disturbances of deepsea environment, and accomplish some more challengeable and practical missions.

Low Gate Voltage Operated Multi-emitter-dot H^+ Ion-Sensitive Gated Lateral Bipolar Junction Transistor

A low gate voltage operated multi-emitter-dot gated lateral bipolar junction transistor （BJT） ion sensor is proposed. The proposed device is composed of an arrayed gated lateral BJT, which is driven in the metal-oxidesemiconductor field-effect transistor （MOSFET）-BJT hybrid operation mode. Further, it has multiple emitter dots linked to each other in parallel to improve ionic sensitivity. Using hydrogen ionic solutions as reference solutions, we conduct experiments in which we compare the sensitivity and threshold voltage of the multi-emitter-dot gated lateral BJT with that of the single-emitter-dot gated lateral BJT. The multi-emitter-dot gated lateral BJT not only shows increased sensitivity but, more importantly, the proposed device can be operated under very low gate voltage, whereas the conventional ion-sensitive field-effect transistors cannot. This special characteristic is significant for low power devices and for function devices in which the provision of a gate voltage is difficult.

Analysis of the Self-Protection Characteristics of a 1.5T Bitter-Like HTS Magnet Operated at 65K

We present a conceptual configuration of a high-temperature superconducting（HTS）magnet made from REBCO（Re=Rare Earth,B=Barium,C=Copper,O=Oxide）annular plates,called a Bitter-like HTS magnet,which can operate in persistent current mode without joint resistance and can be excited by a flux pump and without current leads and a persistent power supply.An REBCO annular magnet which can generate 1.5 T corresponding to the operating current density 80%of critical current density of the magnet at an operating temperature of65 K is conceptually designed.Then the thermal stability of the magnet is numerically simulated by Comsol software.Whein a piece of RBCO annular plate quenches,the maximum released energy is its stored energy because each REBCO annular plate in the Bitter-like magnet is in parallel.To calculate the stored energy in the REBCO annular plate,the inductance of every annular plate,including self-inductance and mutual inductance,is calculated.Compared with the minimum quench energy（MQE）and stored energy in one REBCO annular plate,the stored energy in one REBCO annular plate is always smaller than the MQE,and the REBCO annular plate will not be damaged even though the stored energy in the REBCO annular plate is fully released,which indicates that this 1.5 T Bitter-like magnet has the property of self-protection.

THRIVING INDIVIDUALLY-OPERATED ECONOMIC SECTOR

Over the past two years, the individually-operated economic sector in Shandong Province has made rapid development. By the end of 1993, the number of individual households engaged in industrial and commercial undertakings in the province had reached 1.584, involving 3.138 million selfemployed workers, making it the first in the country. The number of licensee

Domestic Trade Successfully Operated By A Foreign-Trade Enterprise

Ahub of commerce in SouthwesternChina, Chengdu in Sichuan Provinceis well known for its thriving and welldeveloped commerce and trade, with rowupon row of modern shopping centers andbazaars scattered along various specializedbusiness streets. One can imagine how fierceis the competition behind the scenes of thebustle and boom of business! Downtown, anarea known as the Manhattan of Chengdu, anewly built commercial building is growingup, becoming one of the five biggest shoppingcenters in the city; it is the Chengdu ForeignTrade building which opened to businessonly a year ago.

Epidemiological, Clinical and Radiological Study of Patients Operated on for Spondylolisthesis in the Neurosurgery Department of CH “the Luxembourg” in Bamako

Introduction: Spondylolisthesis is defined as a permanent anterior sliding of the vertebral body accompanied by the pedicles, the transverse processes and the posterior joints in relation to the underlying vertebra. The prevalence of spondylolisthesis varies between 4% and 9%, according to different authors in France, China and Japan. In Africa, some African authors find a spondylolisthesis rate of 9.93%. The objective of this study was to study the clinical and radiological aspects of spondylolisthesis at the Mother-Child Hospital of Bamako. Methods: Prospective and retrospective descriptive study carried out in the neurosurgery department of CH Mother-Child Luxembourg in Bamako from 2010 to 2018. Result: We collected 42 patients operated on for spondylolisthesis out of 145 patients, i.e., 29% of the department’s activities. The average age of our patients was 51 years old, with extremes of 20 and 75 years old. The sex ratio was 0.81 in favor of women. 61.9% of our patients performed work requiring physical strength. Neurogenic claudication was the predominant clinical sign with 88.1% of cases. CT was the most common way of exploration in 57.1% of cases and CT myelo in 47.6% of cases. Disc herniation was associated with spondylolisthesis in 23% of cases. Spondylolisthesis was grade 1 in 59.6% of cases and was responsible for mixed stenosis in 73.82% of cases. All our patients underwent laminectomy. The evolution at 6 months postoperative was favorable in 64.3% of cases. Conclusion: The diagnosis of spondylolisthesis is radiological and makes it possible to define the type of lesion according to its etiology and its severity, but also to highlight the conflicts with the nervous system which will have to be cured. Field and household work, pregnancy, carrying loads or children on the back could be incriminated.

Impact of Thickness of Polymer Electrolyte Membrane and Gas Diffusion Layer on Temperature Distributions in Polymer Electrolyte Fuel Cell Operated at Temperature around 90℃

Polymer Electrolyte Fuel Cell(PEFC)is desired to be operated at temperature around 90℃ for stationary applications during the period from 2020 to 2025 in Japan.It can be expected thinner polymer electrolyte membrane(PEM)and gas diffusion layer(GDL)would promote the power generation performance of PEFC at this temperature.The aim of this study is to understand the impact of thickness of PEM and GDL on the temperature profile of interface between PEM and catalyst layer at the cathode(i.e.,the reaction surface)in a single PEFC with an initial operation temperature(Tini).An 1D multi-plate heat transfer model based on temperature data of separator measured using thermograph in power generation process was developed to evaluate temperature of the reaction surface(Treact).This study investigated the effect of Tini,flow rate and relative humidity of supply gas on Treact distribution.The study finds that when using thin GDL,the even distribution of Treact – Tini is obtained irrespective of thickness of PEM,Tini and relative humidity conditions.Treact – Tini using Nafion 115 is higher than the other thin PEMs irrespective of Tini and relative humidity conditions.It can be concluded that the even temperature distribution could be achieved by using thin PEM and GDL.

A real-world data collection framework for a fused dataset creation for joint human and remotely operated vehicle monitoring and anomalous command detection

Unmanned Remotely Operated Vehicles(ROVs)are widely used in safety-critical missions,spanning across monitoring,surveillance,and search and rescue missions.In most cases,the human operator controls the ROV under stressful conditions and in harsh environments.The physical and mental states of the operator are vital as they may cause involuntary movements,issuing unintentional commands due to fatigue or stress.Consequently,a joint monitoring mechanism that will assess the operator's commands can be beneficial in preventing potentially catastrophic events,such as accidents.To this end,in this study,we propose a data collection framework for creating a fused dataset,consisting of data obtained from both the human operator and the ROV,and we integrate stress induction to stimulate stress and fatigue that may affect operators during missions.We optimise the dataset,which includes the operator's physiological signals and inertial measurement unit(IMU)sensor data from the ROV,using data fusion approaches and feature extraction.We evaluate the dataset through the statistical analysis,illustrating a statistical difference between data characterising normal and involuntary commands.Finally,we evaluate the optimised and original datasets over a variety of classifiers,demonstrating an accuracy of 94%and 95%,respectively.

Electronic Load Controller for a Parallel Operated Isolated Asynchronous Generator Feeding Various Loads

This paper presents an investigation on a voltage and frequency controller (VFC), which functions as an improved elec-tronic load controller (IELC) for parallel operated isolated asynchronous generators (IAGs) in an autonomous hydro power generation system. In such type of hydro scheme whole generating system is isolated from the grid and supply electricity to the remote communities. The single point operation of these generators is realized, in such a manner that excitation capacitors, speeds, load, voltage, currents of generators remain constant under various operating conditions. The proposed controller consists of a 3-leg IGBT (Insulated Gate Bipolar Transistor) based voltage source converter (VSC) and a DC chopper with an auxiliary load at the DC bus of the VSC. The IELC controls the reactive and active powers simultaneously for controlling the voltage and frequency under varying consumer loads. Along with voltage and frequency control through single point operation of IAGs driven by uncontrolled pico hydro turbines, the IELC meets the power quality standard an IEEE-519 and it keeps the total harmonic distortion (THD) of the terminal voltage and currents within the limit of 5%. Here the proposed electrical system along with its controller is modeled in MATLAB along with Simulink and PSB (Power System Block-set) toolboxes. Simulation results are presented to demonstrate the capability of proposed controller for an isolated generating system.

Process Adaption of a Small WWTP Operated at Low Loading Conditions for Substantial Energy Savings

The very long tradition of the activated sludge treatment model within the water industry has demonstrated very versatile possibilities to adopt the operation mode for different enhancements. By looking into other treatment models within the activated sludge family it is possible to find alternatives for the operation. This paper concentrates on the possibilities to improve even small WWTP with respect to energy savings. The small plant in Northern Sweden, called Rosvik WWTP, is given as an example. Some important findings related to the intermittent aeration mode may be summarized as follows: 1) An energy savings for the operation of the small WWTP with respect to aeration needs that resulted in a decrease of the energy power supply by more than 35%, as compared with the previous operation based on continuous aeration;2) The up to date effluent levels with respect to the main pollutants have remained at very good levels in 2020, P-level averages 0.16 mg P/l versus consent level < 0.5 mg P/l;COD-level 40 versus < 70 mg/l and BOD7 9 versus < 15 mg/l;3) Sometimes, also improved sludge settling characteristics have been observed, thus providing improved discharge figures;4) The potential to develop an enhanced biological phosphorus removal. There are however some needed conditions to accomplish these improvements: 1) Reliable on-line probes for both oxygen control, SS-concentration control and optionally also for nitrogen control;2) A flexible automation system that allows the needed process modifications to take place;3) And finally, very important dedicated and competent plant operators, with the needed curiosity for operation improvements.

The Impacts of Income from Non-agricultural Industries Operated by Rural households on Farmers' Income

Income from non-agricultural industries operated by rural households is an important income source of farmers' income. According to the Regional Rural Residents' Net Income Per Capita in 2004 issued by the State Statistics Bureau and the relevant statistics of national comprehensive investigation(CGSS2005) in 2005, the impacts of farmers' income gap and farmers' individual features on their income and the impacts of income from non-agricultural industries operated by rural households on farmers' individual income differences are analyzed by applying Hierarchical Linear Models (HLM) as an analysis tool to establish the null model of HLM, excluding the second level model of the second level prediction variables and including the second level model of the second layer prediction variables. The analysis assumes that farmers' individual income varies hugely in different provinces; farmers' individual income has close relation with farmers' individual features; the improvement of income from non-agricultural industries operated by rural households has different impacts on farmers' income.

A Short Term Review of Operated Cases in the Plastic Surgery Unit at the Komfo Anokye Teaching Hospital, Kumasi, Ghana

Introduction: Surgical problems are of much disturbance to the world and should therefore be given serious attention. The prevalence of these surgical problems, has made plastic surgery become a broadly relevant and acceptable way for addressing problems like injuries, congenital anomalies, surgical infections and malignancies among others. Aim: This study is to quantify and characterize surgical procedures done in the plastic surgery theatre located in the new Accident and Emergency (A & E) Building of KATH. Materials and Methods: Data were obtained from the Operation Register/Theatre Books in the plastic surgery theatre at the A & E Centre on cases operated on from October 1, 2009 to September 30, 2012. Data entry, presentation and analysis were done using Statistical Package for the Social Sciences (SPSS) 20.0 version. Results: Adults formed the majority of patients who sought for plastic surgery with a percentage of 70.3%. The male patients also outnumbered the females recording (61.5%) out of the total number of patients. Most of the cases recorded were acquired cases (93.2%). Reconstructive surgery was the commonest operation performed (30%);in 53.8% cases general anaesthesia was used. Conclusion: Among all the procedures used reconstructive surgery was the commonest surgery performed in the unit and general anaesthesia was the most type of anaesthesia used for the operations.

Process Adaption and Modifications of a Nutrient Removing Wastewater Treatment Plant in Sri Lanka Operated at Low Loading Conditions

The Sri Lankan national water authority, that is The National Water Supply and Drainage Board (NWS&DB) has taken a new wastewater treatment plant into operation at Ja Ela, North of Colombo. The plant has been in operation since September 2011. In April 2012, it was concluded how a test of the aeration efficiency and a performance test should be carried out. The tests have been based on the actual loading of the plant and the analysis results from the daily process control. The evaluation of the aeration efficiency is not reported in this paper. The paper presents the overall performance of the water treatment part of the plant during start-up conditions, from fall 2011 through the first five months of 2012. The results from the operation are found in Table 1. An important circumstance at the plant is the current very low loading in comparison with the design load. This fact has resulted in an introduction of an intermittent mode of the aeration (nitrification) reactor. Based on operation figures, during more than a month (May 2012), it has been possible to give a realistic assessment of the overall performance. The most striking results are summarized as follows: 1) The intermittent operation has enabled an energy efficient operation of the plant. By the introduction of the intermittent aeration, the energy consumption has been reduced by around 75%, compared with the continuous operation mode;2) The plant performance during the intermittent operation has been improved with respect to virtually all important pollution variables. The most striking improvement is the discharge total P level, reflecting that a substantial enhanced biological phosphorus removal takes. The typical discharge levels found during May 2012, were compared with the earlier obtained values. It is important to underline that the loading on the plant has slightly increased during May as compared with the previous operation period.

Comparison of Physical Therapy Follow-Up of Patients with Operated and Non-Operated Lumbar Spinal Stenosis According to the Nottingham Health Profile-Pain Scale

Background: Lumbar spinal stenosis (LSS) continues to be a major problem in societies, causing job loss and lowering quality of life. There are two types of treatment methods, physical therapy and surgery. If patients with LSS avoid treatment, they are likely to experience neurological deterioration in later years. Objective: The study aimed to evaluate the effect of physical therapy applied after decompression surgery or the effect of only applied physical therapy in patients with lumbar spinal stenosis. Materials and Methods: The results of the physical therapy follow-up of patients who had surgery and did not have surgery due to lumbar spinal stenosis between July 2014 and December 2019 were compared with each other. All patients received physical therapy for 6 months. Included were 42 patients who underwent decompression surgery due to LSS; 56 patients were not operated. Clinical outcomes were measured using the Nottingham Health Profile-Pain (NHP-Pain) scale at the initial, first, third and sixth months. The results were compared statistically. Results: The age of the operated patients was 54.69 ± 8.42 (39 - 71), while the non-operated patients were 59.16 ± 14.04 (34 - 83). There was no significant difference in the statistical comparison (p = 0.053). While the body mass index (BMI) of the operated patients was 29.43 ± 4.99 (21 - 40), the BMI of the non-operated patients was 28.84 ± 4.62 (22 - 42). There was no significant difference in the statistical comparison (p = 0.552). The scores of a 6-month physical therapy follow-up of patients were evaluated according to the NHP-pain scale. The values of patients who underwent surgery, initial - 1st month (p < 0.001), 1st month - 3rd month (p = 0.028), 3rd month - 6th month (p = 0.389) follow-up of the intervals were compared statistically. The values of non-operated patients, initial - 1st month (p = 0.008), 1st month -3rd month (p = 0.013), 3rd month - 6th month (p = 0.025) were compared statistically. Patients with and without surgery had significantly different initial pain scores (p < 0.001). Conclusions: The NHP-Pain scores of the patients undergoing physical therapy with the operation were shown to provide more significant improvement than the group receiving only the physical therapy. Patients with LSS should be treated with an operation to obtain the maximum benefit of physical therapy.

低温等离子治疗儿童鼻咽部第二鳃裂囊肿分析

目的探讨儿童鼻咽部第二鳃裂囊肿的临床特征和治疗方式,提高诊治能力。方法回顾性分析河北省儿童医院收治的4例儿童鼻咽部第二鳃裂囊肿的临床资料,包括年龄、性别、症状、影像学资料和治疗过程。总结分析病变部位特点,B超、CT或MRI特征,术后病理结果及治疗方式。结果4例鼻咽部第二鳃裂囊肿患儿均表现为鼻咽侧壁咽鼓管咽口与腭咽弓后上方连线上的囊性肿物,囊壁较厚,影像学检查结果均为囊性病变。4例患儿选择内镜下低温等离子病变切除术,其中2例为内侧囊壁大部分切除术,将囊腔充分敞开,2例为囊肿全部切除术。术后病理提示衬覆纤毛柱状上皮或复层上皮,周围淋巴组织增生。术后随访1.5~3年无复发。结论儿童鼻咽部第二鳃裂囊肿临床罕见,诊断主要依靠病变部位及术后病理结果,内镜下低温等离子切除病变组织是微创、安全、有效的治疗方式。

Fractal Fractional Order Operators in Computational Techniques for Mathematical Models in Epidemiology

New fractional operators, the COVID-19 model has been studied in this paper. By using different numericaltechniques and the time fractional parameters, the mechanical characteristics of the fractional order model areidentified. The uniqueness and existence have been established. Themodel’sUlam-Hyers stability analysis has beenfound. In order to justify the theoretical results, numerical simulations are carried out for the presented methodin the range of fractional order to show the implications of fractional and fractal orders.We applied very effectivenumerical techniques to obtain the solutions of themodel and simulations. Also, we present conditions of existencefor a solution to the proposed epidemicmodel and to calculate the reproduction number in certain state conditionsof the analyzed dynamic system. COVID-19 fractional order model for the case of Wuhan, China, is offered foranalysis with simulations in order to determine the possible efficacy of Coronavirus disease transmission in theCommunity. For this reason, we employed the COVID-19 fractal fractional derivative model in the example ofWuhan, China, with the given beginning conditions. In conclusion, again the mathematical models with fractionaloperators can facilitate the improvement of decision-making for measures to be taken in the management of anepidemic situation.