bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Vibration Characteristics of Piezoelectric Ceramic Atomizer Based on ANSYS
Authors: Chen Yan , Ma Chunyan , Shen Zaihe , Chen Rui
Published: October 2019

In the design and application of ultrasonic atomizer, the resonant frequency and vibration mode of piezoelectric transducer have an effect on the working state and atomization effect of the atomizer. In order to deeply study the piezoelectric ceramic ultrasonic atomizer Vibration characteristics, piezoelectric coupling simulation analysis was performed by ANSYS software, multi-order vibration mode of piezoelectric ceramic atomization sheet obtained by modal analysis method, combined with harmonic response analysis to obtain resonant frequency of piezoelectric ceramic ultrasonic atomization sheet, and analysis the influence of the main size of the atomized sheet on the vibration mode. According to theoretical analysis and experimental tests, the effectiveness of the finite element analysis can be verified, and then provide a theoretical basis for the study of ultrasonic atomizers.
Transient Characteristics Analysis of 500kV Parallel Circuit Breaker Based on Highly Coupled Split Reactor
Authors: Xiang Changyuan , Xiang Zutao , Xu Wenjia , Xiang Weihua
Published: October 2019

With the continuous expansion of power system capacity, parallel high-voltage circuit breakers with a Highly Coupled Split Reactor (HCSR) have a potential application for limitation of high short-circuit current. However, as the parallel circuit breakers open at different time, the residual voltage of the split reactor on the post-open circuit breaker is higher and the stray capacitors of HCSR form high-order oscillating circuits, which may lead to serious transient recovery voltage (TRV). Therefore, it is necessary to analyze and simulate the transient characteristics of 500kV HCSR. Firstly, the equivalent model of HCSR circuit breakers is built in EMTP simulation plat-form, and its TRV generation is analyzed. Then, the TRV of parallel circuit breakers under different operating conditions and fault types is simulated and calculated. Finally, according to the statistical calculation results, the protection measure of 0.2uF shunt capacitance to limit rise rate of TRV is proposed.
Cost Comparison Based on Transformer Operating State Under Two Kinds of Inspection Strategies
Authors: Cao Boyang , Ren Yi , Wang Yaping , Wen Weining , Sun Huijun , Zhang Yan , You Lisha , Wang Wenhao
Published: October 2019

Based on the analysis of traditional state maintenance strategy and big data-based state maintenance strategy, this paper builds a transformer state duration simulation model based on Monte Carlo method and builds an annual cost model based on the running state of the transformer. Finally, a typical case is selected to simulate a time series of 8760 hours of transformer operation under two operational inspection strategies, and the annual cost is calculated separately. The example shows that the annual cost of the transformer is lower under the big data-based inspection strategy.
Multi-physics coupling finite element analysis of 10kV tri-axial HTS cable
Authors: Cao Jingying , Chen Jie , Yang Liu , He Qidi , Liu Gang , Hu Libin , Tan Xiao , Li Chenying
Published: October 2019

As an important equipment of power transmission, power cable has been required better performance on cable line loss and current ampacity to achieve its high reliability. This paper proposes an advanced application of superconducting transmission technology in power grid, namely tri-axial high-temperature superconducting (HTS) cable. The corresponding simplified model is established for multi-physical field analysis, and the size of each structure is determined through structural design. The temperature distribution of the cable body is analyzed according to multi-physical field coupling, and the influence of flow rate, size and other factors on the stability of the system is studied. In this paper, it is found that increasing liquid nitrogen volume and flow rate have saturation limit for lowering cable body temperature, and the axial temperature rise rate of cable body tends to be stable when it is greater than 4m. Multi-physical field analysis provides a basis for the design of HTS cable length without having system quench or liquid nitrogen gasification.
Analysis and Treatment of 660 MW Ultra Supercritical Units Vibration
Authors: Bing Hankun , Zhao Yuzhu , Wu Zhengfeng , Chen Shuai
Published: October 2019

This paper analyses the excessive vibration of the bearing caused by the high-medium pressure rotor bending of the steam turbine, provides a basis for the weighted and balanced bending scheme of the high-medium pressure rotors of the 660MW ultra-supercritical unit and also provides reference for the same type of unit.
Householder-based Prony Method for Identification of Low-frequency Oscillation in Power System
Authors: Zhang Simin , Liu Guangye , Li Yaxin , Yao Jiangang
Published: October 2019

In this paper, the Prony analysis tool with the software used in the actual operation has a large error. The improved Prony method is used to identify the low-frequency oscillation mode of the power system. The traditional Prony algorithm has the problem of insensitivity to parameter error estimation in low frequency oscillation, which affects the accuracy and accuracy of the least squares calculation. Therefore, this paper proposes a Prony method power system low frequency oscillation method using Householder transform to make the calculation more Accurate and proven to be more efficient and reliable.
A new grounding model for complex soil environments
Authors: Pan Chong , Zhao Dong , Tu Xuesong , Wang Shuqin , Liu Tie , Li Yiqiao
Published: October 2019

The purpose of arranging the grounding electrode is to discharge large currents, such as fault current and ensure the transmission line operate safely. In the grounding system of Chinese transmission network, the common grounding electrodes are horizontal installation and vertical installation. But two installation methods usually have the disadvantages, which are long distance installation and large depth burying, and they are restricted susceptible to uncertain factors such as pipelines, roads and geology, which leads the grounding resistance increasing and affect the normal operation of transmission lines. In order to solve the problem, this paper presents a new grounding model for complex soil environments and analysis from grounding resistance, surface potential and current distribution. The results show that the helix grounding electrode has good resistance reduction performance in complex soil environment, which effectively improves the surface potential distribution and the distribution of the spill current.
The Investigation of the Indoor Temperature During the Heat-Supplied Period and Its Influence in Winter in China
Authors: Wang Linhai , Liu Zhao
Published: October 2019

It is found that the heat-supplied temperature in winter is generally too high by investigating the heat-supplied samples in China. The excessively high temperature increases energy consumption, aggravates environmental pollution, and leads to frequent occurrence of diseases such as respiratory disease, cardiovascular and cerebrovascular disease. Therefore, it is suggested that the heat-supplied temperature should be controlled under 20°C.
Landscape renewal of urban public space under the concept of sustainable development: a case study of Guilin city
Authors: Zhao Fang , Lai Yanni , Du Qin , Xie Xuefang , Chen Qiutong , Qin Ziliu
Published: October 2019

With the theory of “sustainable development” as the theoretical support, the public space landscape of Guilin City is taken as the research object, and from the perspective of landscape architecture, the public space landscape and the non-sustainability issues are deeply analyzed.Guilin city has been deeply investigated and studied.According to various types of public space landscape, five problems are concluded:landscape space problem, landscape energy consumption problem, landscape greening and planting problem, landscape rainwater resources digestion and utilization problem and landscape pollution reduction and noise reduction problem.The smooth solution of these five problems can promote the improvement of the urban environment and create sustainable urban public space.
Research on the Performance and Enlightenment of New York Storm Surge Adaptive Landscape Infrastructure
Authors: Lu Feng
Published: October 2019

In the context of global warming, the study of the resilient city and resilient landscape has received more and more attention. In this work, New York is used as an example to explore the practical applications of storm surge adaptive landscape infrastructure. The vulnerability of New York in storm surges and New York’s plans for resilient city construction are introduced. Then according to the spatial distribution, through field research, questionnaires and data integration, the landscape infrastructure cases of beaches, waterfront parks, inland parks, nature areas and streets are studied, and their performance in Sandy is analysed. After that, under the guidance of resilient city theories and storm surge adaptation strategies, the experience that can be learned from these cases is summarized.
Research on the Strategy of Urban Ecological Competitiveness under the Integration of the Yangtze River Delta -Taking Meilong Town of Shanghai as an example
Authors: Li Shuai , Yang Yan , Yu Yiting , Li Zhao , Li Linlin
Published: October 2019

As the main form of new urbanization, urban agglomeration regional integration has gradually become an important carrier and platform for leading China’s economic transformation and upgrading. The Yangtze River Delta urban agglomeration is one of the largest urban agglomerations in China, and its integrated and coordinated development is of great significance to China. Taking the Meilong Town of Shanghai as an example, this paper summarizes the impact and role of high-quality urban development under the integration of the Yangtze River Delta. Through the analysis from the perspectives of spatial structure, land use layout, urban renewal, and water grid bureau, the urban development under the integration of the Yangtze River Delta was initially explored.
Genetic Diversity of Microbial Eukaryotes in the Pelagic and Littoral Zones of Lake Taihu, China
Authors: Zhao Biying , Chen Feizhou
Published: October 2019

Genetic diversity of microbial eukaryotes (0.8-20 μm) and its seasonal variation in the pelagic and littoral zones were investigated from in Meiliang Bay of Lake Taihu in China. The water samples were collected in four seasons (February, May, August, and November). The genetic diversity of microbial eukaryote was analyzed by terminal restriction fragment length polymorphism (T-RFLP) of PCR-amplified partial eukaryotic 18S rRNA fragments. T-RFLP indicated that the microbial eukaryotic community compositions differed between the pelagic and littoral zone, but the difference decreased in warm seasons. The main environmental factors which affected on the variations of microbial eukaryotic community compositions in pelagic and littoral zones were revealed by multivariate statistical analysis. The canonical correspondence analysis between the genetic diversity of microbial eukaryotes and environmental factors revealed the trophic status had the most important impact on the microbial eukaryotic communities. Besides, a strong top-down regulation of microbial eukaryotes by zooplanktons was found in summer.
Empirical Study on Coupling and Coordinated Development of “Energy-Finance-Environment” in the Middle Reaches of Yangtze River
Authors: Peng Duyun
Published: October 2019

In the important transition period of high-quality development in China, it is of great significance to explore the coordinated development among finance, energy and environment. In this paper, the dynamic average weight method with improved entropy value is used, and the index system of “energy-finance-environment” three-dimensional system (hereinafter referred to as “EFE system”) is established to explore the coordinated development and dynamic evolution of the coupling. The results show that the newly constructed dynamic average weighting method is reasonable and effective, and can reflect the time-varying characteristics of each subsystem index weight; from 2009 to 2017, the EFE values of the four provinces in the middle reaches of the Yangtze river present different development trends, and the trend of finance shows an overall upward trend, while the trend of environment and energy show twists and turns; the coupling degrees of the four provinces are high, but the coordination degrees are generally low, failing to reach the coordination level; the restricting factors of coordinated development are mainly the backward type of financial development and energy efficiency. This conclusion provides a reference for a more rational grasp of the coordinated development of EFE system in the middle reaches of Yangtze river.
The corps’ growth with different water-saving irrigation conditions in new reclamation areas along the coast of Jiangsu
Authors: Wang Jun , Weng Songgan , Wang Tongshun , Yang Xing , Hou Miao , Zhang Xinyuan
Published: October 2019

This study performed a quantitative evaluation of the impact of the corps’ growth with different water-saving irrigation conditions in new reclamation areas along the coast of Jiangsu. In this work, the yield and the amount of irrigation water of corps’ (watermelon, green pepper, and rice) with different water-saving irrigation modes were investigated. The results indicate that the drip-irrigation and micro-spray irrigation can observably reduce the amount of irrigation-water. With respect to normal irrigation, the rate of water-saving is 39.2%. At the same time, there’s been some improvement in the yield of corps. Water-saving irrigation can been accepted as an important means for alleviating the shortage of fresh water resources in the new reclamation.
Spatial-temporal Pattern Evolution of Ecological Land Use in Hebei Province
Authors: Wang Qian , Li Jinlu , Liang Zhongya
Published: October 2019

Ecological land use is an important component of ecosystem. This study presents spatial and temporal pattern evolution characteristics of ecological land for the period from 2009 to 2017, based on GIS technology and mathematical statistics. The results show that ecological land structure is stable, amount tends to decrease, average annual decrease of 21, 000 hm2. Ecological land types were mainly transformed into farmland and urban land, Internal transformed mainly between woodland and grassland. Spatial aggregation were existed, Aggregation degree: forest land > grassland > water area and wetland > desert. But high concentration areas (“HH” related area) is reduced from 11 counties to 9 counties, and low concentration areas (“LL” related areas) increased from 37 counties to 40 counties, from 2009 to 2017. According to the results, proposals for ecological land use were put forward.
Physical Experiment Research on Dielectric Properties of Hydrate-bearing Sediment in Sandstone Reservoir
Authors: Du Bing-rui , Bai Da-wei , Zhang Peng-hui , Guo Peng , Zhang Qiang
Published: October 2019

Dielectric constants can be used to detect hydrates in permafrost regions. Therefore, this study investigated the relationships between the dielectric constant characteristics of sandstone reservoir hydrate and the hydrate saturation degree through physical simulation experiments, as well as the granularity of the surrounding rock. Methane and tetrahydrofuran (THF) hydrates with quartz sands were prepared, and their dielectric constants were analyzed. With different granularities of quartz sands, the dielectric constants of two different methane hydrate sediments decreased with increasing saturation degrees. At a given saturation degree, the dielectric constant of methane hydrate sediments with small granularity was larger than that with medium granularity, a result attributed to the unreacted water in the larger pores of the latter. In addition, the dielectric constant of methane hydrate sediments was larger than that of THF hydrates, which was also attributed to gas-phase factors and the presence of unreacted water. At a given granularity and saturation, the dielectric constants of both the THF and methane hydrates decreased with increasing saturation degrees. We conclude that at low temperature and under normal pressure, THF hydrates cannot be used as a substitute for methane hydrates in laboratory experiments investigating geophysical phenomena.
Research on hydrogen generation from rapid hydrolysis of aluminum in sodium fluoride solution
Authors: Li Changchun , Wu Yuxin
Published: October 2019

Hydrogen generation from rapid hydrolysis of aluminum in sodium fluoride solution was investigated through a hydrolysis experiment. Rapid and instant hydrogen yield were observed using sodium fluoride as additive. The experimental results demonstrate that the increase of temperature and the amount of additives in a certain range will boost the hydrogen production. The amount of additives outside the range only has an effect on the rapid hydrolysis of the aluminum during the initial stage, but the total amount of hydrogen produced doesn’t increased significantly. Theoretical analysis of the effects of the mixing ratio and the temperature on the hydrogen production rates were performed using the shrinking core model and the kinetic model. The shrinking core model parameter a and k indicate the film change degree of porosity and thickness and the effect of time on the diffusion coefficient. the kinetic model is verified and the activation energy confirming hydrogen yield control by a molecular diffusion process. Correspondingly, mechanisms of Al corrosion in NaF solutions under low and high alkalinity were proposed, respectively.
Study On Photovoltaic Modules On Greenhouse Roof For Energy And Strawberry Production
Authors: Tang Yilian , Li Ming , Ma Xun
Published: October 2019

The aim of this study was to investigate the effect of PV modules mounted on top of a greenhouse, on the growth of strawberries and microclimate conditions as well as to estimate the generated energy. In this study, two greenhouses with the same volume were established. One greenhouse was equipped with the opaque photovoltaic (OPV) modules which accounted for 25.9% of the roof area, and the other was equipped with the semi-transparent photovoltaic (STPV) modules which accounted for 20% of the roof area. The maximum annual power generation of OPV and STPV modules was 880 and 388 kWh with 30° tilt angle, respectively, by simulating different tilt angles. The temperature under the OPV and STPV modules was 2.9 and 1.1 °C lower than the unshaded part in the greenhouses, respectively, at noon in clear weather, and had little effect on relative humidity. The photosynthetically active radiation (PAR) under OPV and STPV modules was reduced by 43.5% and 31.7%, respectively, under the PE film greenhouse. The contents of soluble solids in strawberries in OPV and STPV greenhouses were 16.4 and 15.7 mg/g respectively, which were higher than those in unshaded samples. The quality and yield of the strawberry samples under the shade of OPV were better than those of the STPV shade.
Study on the Process of Degradation of Phenolic Compounds in Water by Slot Ultrasonic
Authors: Bi Yong-guang , Zheng Yu-hong , Zhou Shao-qi
Published: October 2019

The test results show that the degradation rate of phenol decreases with the increase of ultrasonic power. The effect of degradation increases by studying the effects of the power of the ultrasonic, the initial concentration of the phenol sample solution, and the pH of the phenol sample solution. The degradation rate of phenol increases first and then decreases with the increase of initial concentration, and the degradation rate of phenol is up to 31.86%. The ultrasonic degradation technology can provide reference for the application of industrial wastewater treatment.
Study on the Mechanism of Gas Component Release for Biomass Pyrolysis
Authors: Li Hongtao , Wang Li , Ji Yunguang , Xue Shuqi , Wang Zhenhui
Published: October 2019

Biomass energy utilization can solve the contradiction between economic development and energy and environment. Biomass pyrolysis technology is not only one of the thermochemical conversion technologies, but also the necessary stage of biomass gasification, which has become a hot academic research topic. Firstly, based on the pyrolysis experimental data of cellulose, hemicellulose and lignin, the analytical expressions of pyrolysis gas mass yields of different biomass components varying with temperature were obtained; then, the prediction of pyrolysis products was obtained by mass component superposition method, and the correction coefficient of biomass pyrolysis gas yield model was obtained based on the comparison between the average yield of biomass pyrolysis gas and the predicted value of pyrolysis products; finally, the gas release mechanism model of biomass pyrolysis was obtained. This study provides theoretical basis and technical support for the development of biomass utilization technology.
Research on promoting the conservation and utilization of agricultural water resources in in the Beijing-Tianjin-Hebei Region under the background of agricultural green development
Authors: Zhao Guang , Dou Yanfen
Published: October 2019

The conservation and utilization of agricultural water resources plays an important role in promoting the green transformation of agriculture. In this background, this paper systematically describes the current situation of agricultural water resources conservation and utilization in the Beijing-Tianjin-Hebei Region. At the same time, this paper points out that the agricultural water resource conservation and utilization in the Beijing-Tianjin-Hebei Region are confronted with such problems as the low degree of popularization and application of water-saving technology, the need to improve the depth and breadth of regional coordinated development, the unsound management mechanism, the insufficient capital investment and the imperfect talent support system. In view of the above problems, this paper puts forward countermeasures and suggestions to promote the conservation and utilization of agricultural water resources in the Beijing-Tianjin-Hebei Region, so as to better promote the agricultural green transformation and development in the Beijing-Tianjin-Hebei Region.
Study on the Influence of Slope on Pollutant Diffusion Characteristics during Tunnel Construction Period
Authors: Ai Zubin , Song Zhongqiang , Chen Fan , Yang Song , Cao Zhensheng , Liu Rong
Published: October 2019

. The relative elevation of the beginning and end of the Jianyuan Expressway exceed 1000m. In order to overcome the impact of the large slope on traffic safety, a spiral tunnel was designed in the middle of the expressway. The tunnel length is 3970m and the radius is 710~730m with its slope being up to 2.08%. The occurrence of large slope has a great impact on ventilation and smoke during tunnel construction, but little research has been done before. In this paper, numerical simulation and field test were used to study the effect of slope on the diffusion characteristics of pollutants. It was found that as the slope increased, the wind speed and CO dilution rate also increased. However, the dust dilution characteristics were different. Especially in the case of the downward tunnel, the effect of wind speed on the sedimentation rate of dust was minimal. Simply increasing the wind speed cannot speed up the dust reduction rate.
Dynamic evaluation of ecosystem service value in southern mountainous areas of Jinan based on 3 “S” technology
Authors: Zhao Huaiqun , Xie Fuju , Cao Mengzhu , Wei Wei , Wang Hong , Zhao Mingquan
Published: October 2019

In this paper, change of land cover and use type was first studied through interpretation of the two images (2007 and 2018), and then, dynamic evaluation of ecological service value in Southern Mountainous Areas of Jinan was made with evaluation system and equivalent factors built by Xie GD based on Costanza’s system. The results revealed that the area of bare land and grass land decreased by 4875.48 hm2 and 55141.56 hm2 respectively, on the contrary, cultivated land, forestland and building land has increased by 26915.671 hm2, 32261.31 hm2 and 1442.16 hm2 respectively. The ecological service value showed the increasing trend generally, among of which water conservation, air regulation, land protection, recreation have increased distinctly, which can be explained that the control develop strategies had taken action actively.
Particle Size Distribution Based Occurrence Features of Organic Components in Printing and Dyeing Wastewater Under a Treatment Process
Authors: Li Yuan , Liu Jie , Yu Yibiao , Zhu Hao , Shen Zheng , Zhang Yalei
Published: October 2019

A more detailed occurrence features of organic matters in the printing and dyeing wastewater, based on its particle size distribution (PSD) and along with a wastewater treatment process, was conducted to provide a support for advanced treatment. Results suggested that, (1) In the dyeing wastewater, the occurrence characteristic of COD was: soluble>supra colloidal>colloidal>settleable; However, for protein, the supra colloidal was dominant, followed by the soluble. The feature of the polysaccharide was consistent with COD’s. In the wastewater, 29.66% of COD could be attributed to proteins and 3.45% of the COD could be attributed to polysaccharides. (2) The relationship among the forms of COD in the primary sedimentation tank, aerobic tank, secondary sedimentation tank, and reverse osmosis-treated concentrated effluent was consistent, that was: soluble>colloidal>supra colloidal>settleable. (3) In the primary sedimentation tank, the settleable COD was almost completely removed; In the aerobic tank, the residual super colloidal COD was not much; After MBR-RO treatment, the COD in the reverse osmosis concentrated water was almost dissolved and only a little presented in other forms.
Temporal-spatial Distribution Characteristics of Air Pollutants in Chengdu Economic Region, China
Authors: Tong Hongjin , Liu Sha , Liao Ruixue , Wei Xiaomei , Che Kangli , Li Fenggang , Liu Wei
Published: October 2019

The previous characteristics researches of air pollution were almost based on data from national environmental monitoring stations in 2015. The temporal variation curves of air pollutants and the ArcGIS grid interpolation method were used to analyze the spatial-temporal variation of air pollutants in five cities of Chengdu economic region. In 2015, the monthly change trends of PM2.5, PM10, CO, NO2 and NO of air pollutants in Chengdu economic region were basically the same. The maximum monthly average concentration was in January or December, and the minimum was in May to September. The temporal variation of SO2 was characterized by little fluctuation of monthly concentration. The temporal variation characteristics of O3 were opposite to other pollutants. The spatial distribution of PM10 and PM2.5 was characterized by the largest concentration in Chengdu and the southwest of Meishan, in which they were mainly concentrated in the central area of Chengdu in winter. The average concentration of CO in Chengdu was the largest, followed by Deyang and Mianyang, and Meishan and Ziyang was the smallest. The concentrations of NO2 and NO in Chengdu were the largest, while those in Ziyang were the smallest. The spatial distribution characteristics of O3 were different from other pollutants. The areas with the largest concentration of O3 were Ziyang and a small part of west in Chengdu. The spatial distribution of SO2 was characterized by the largest concentration of SO2 in Ziyang, the lowest concentration in Mianyang and Deyang.
N2O emission and control strategy in different wastewater treatment processes
Authors: Lv Ying , Zhang Shoubin , Yang Yanming , Liu Yutian , Xie Kang , Zhong Jingxiu
Published: October 2019

N2O (Nitrous oxide) is a strong greenhouse gas, and wastewater treatment process is one of the important artificial sources of N2O. Controlling N2O production and discharge in wastewater treatment process is beneficial to alleviate the greenhouse effect. Based on the mechanism of N2O production in biological nitrogen removal process, emission characteristics and influencing factors of N2O in three traditional biological nitrogen removal processes, A/A/O, SBR and oxidation ditch, and two new biological nitrogen removal processes, SBBR and CANON, have been reviewed. Furthermore, a control strategy for slowing the generation and release of N2O is proposed, which provides a reference for researchers in related field.
Cyanobacteria bloom prevention and control and salvage disposal integrated management system
Authors: Tang Yuming , Liang Hong , Zhao Yi , Seng Bingfeng
Published: October 2019

Cyanobacteria are large single-cell prokaryotes that can undergo oxygen-producing photosynthesis. However, if the cyanobacteria are contaminated by nitrogen, phosphorus and other elements, cyanobacteria will cause the phenomenon of “water bloom” in the lake, which will seriously endanger the safety of humans, animals, fish and shrimps. To help lake management units to prevent and control the outbreak of cyanobacteria, this paper designed and developed a comprehensive management system for the prevention and control of cyanobacteria blooms and salvage treatment. The system consists of four subsystems: the operational reporting subsystem, the monitoring data management system, the algae environmental protection disposal process management system, and the real-time cyanobacteria monitoring system. The three-dimensional interaction between the WEB end and the mobile patrol handheld terminal makes the system more efficient and convenient. The neighborhood image is denoised by the neighborhood averaging method, and the K-means algorithm is used for clustering training, which makes the classification of the algae pictures taken. The realization of the system effectively prevented the large-scale outbreak of cyanobacteria, providing a new idea for monitoring and processing cyanobacteria blooms.
Carbon emission assessment of the life cycle of a small town sewage treatment plant
Authors: Lin Lin
Published: October 2019

The rise of greenhouse gas (GHG) concentration has caused global warming to become a consensus in human society. Carbon emissions from sewage treatment plants are one of the main sources of emissions. Among them, carbon emissions from small town sewage treatment plants cannot be ignored. Based on the life cycle (LCA) evaluation theory, the assessment scope of life cycle carbon emissions of small town sewage treatment plants is defined, and a corresponding evaluation system is constructed. According to the system, the carbon emissions of a small town sewage treatment plant in Jilin are evaluated. Based on the assessment results, the ways to reduce carbon emissions from small town sewage treatment plantswere discussed to provide a reference for their emission reduction.
Scenario Assessment of CO2 and Air Pollutants Emission Reduction Policies for Private Passenger Vehicles in China
Authors: Jiang Yanjie , Wu Peilin
Published: October 2019

The rapid increase of private passenger vehicles in China has brought about serious problems of CO2 and air pollutant emissions. It has important practical guiding significance to compare the effects of emission reduction policies. In this paper, the LEAP system is used as a tool with classifying the private passenger vehicles according to the heterogeneity of displacement and fuel economy. The different emission reduction policy scenarios are simulated with respective implementation time and characteristic parameters. It is found that the management target of fuel economy is difficult to be realized by existing policies. Even the most stringent emission standards are all implemented, it is also necessary to cooperate with green travel which is mainly about reducing vehicles’ annual travel distance. Although the annual increment of private passenger car is huge, however, there will be a certain downward trend in the discharge of air pollutants. On this basis, it is suggested that a policy goal of maintaining or lowering the emission level can be established. The research suggests that, on the supply side the government should continue to strengthen the management of fuel economy, improve the emission standards, boost the new energy vehicles vigorously, the energy saving vehicles under overall consideration and diesel cars carefully, while on the demand side the green travel should be encouraged at the same time.
Interventionen mit der Evidenz anderer Disziplinen belegen – Bezugsrahmen
Authors: Heidrich Kathrin , Nied Lea , Kaldewei Nicole , de Freitas Claudia Merklein
Published: October 2019

Als Ergotherapeutin eignet man sich nicht nur berufsspezifisches Wissen an, sondern nutzt auch Erkenntnisse aus Bezugswissenschaften wie der Medizin. Wendet man diese im ergotherapeutischen Kontext an, entstehen Bezugsrahmen, die evidenzbasiertes und reflektiertes Vorgehen ermöglichen.
Betätigung und Funktion sind untrennbar – Ergotherapie in der Neurologie
Authors: Striesow Robert
Published: October 2019

Folgt die Ergotherapie dem Top-down-Ansatz, steht das Betätigungsanliegen des Klienten im Fokus der Intervention. Doch wie sieht das in der Neurologie aus? Lässt sich ein betätigungsorientiertes Vorgehen mit funktionellem Training vereinbaren? Für Robert Striesow gehören die beiden Anteile zusammen – die Gefahr, Potenzial zu übersehen, wäre viel zu groß. Denn insbesondere in der Akutphase können Klienten körperliche Funktionen wiedererlangen.
Mehr als vier Räder – Rollstuhlversorgung in der Geriatrie
Authors: Wittmershaus Caren
Published: October 2019

Mobilität stellt für ältere Menschen ein hohes Gut dar. Benötigen sie einen Rollstuhl, gilt es ihn an den Bedarfen des Nutzers und seines Umfelds auszurichten. Auch der Erhalt der Lebensqualität und der Schutz vor Folgeerkrankungen erfordern eine individuelle Anpassung. Zum Gelingen tragen ein interdisziplinärer Prozess sowie Wissen über Ausstattung und Versorgungswege bei.
Controlling the Diffusion of Multidrug-Resistant Organisms in Intensive Care Units
Authors: Kernéis Solen , Lucet Jean-Christophe
Published: October 2019

The prevalence of multidrug-resistant organisms (MDROs) in intensive care units (ICUs) is increasing worldwide, with very large variations across countries, microorganisms, and settings. Emerging MDR gram-negative bacteria and fungi raise particular concerns that require improved prevention and control strategies. Vertical approaches are mainly based on screening and contact precautions and/or decolonization of MDRO carriers. On the other hand, horizontal strategies are not pathogen-specific and include standard precautions (i.e., hand hygiene), universal decolonization, antimicrobial stewardship, and environmental cleaning. The impacts of the different strategies vary between MDROs and compliance with control measures, and are intermixed in most infection control programs. Based on historical data, hand hygiene remains the cornerstone to prevent transmission of MDROs in ICUs. In the context of high hand hygiene compliance, screening and contact precautions for carriers seem to have a limited additional effect, particularly for MDR gram-negative bacteria. Studies on skin decolonization with chlorhexidine bathing show conflicting results, impairing its widespread adoption. Selective oral and digestive decontaminations have shown positive impact on clinical outcomes in ICUs with low levels of antibiotic resistance, but raised ecological concerns in high-prevalence settings. Antibiotic stewardship programs have been associated with reductions in antimicrobial use, duration of stay, and costs with no negative impact on mortality and should be widely promoted in ICUs. Whatever the strategy, compliance with the recommended measures is of crucial importance and implementation should rely on behavioral approach and change in the institutional and safety culture.
Risk of Recurrent Bleeding Events in Nonvalvular Atrial Fibrillation Treated with Vitamin K Antagonists: A Clinical Practice Research Datalink Study
Authors: Alikhan Raza , Lefevre Cinira , Menown Ian , Lister Steven , Bird Alex , You Min , Evans David , Sammon Cormac
Published: October 2019

Background There is little evidence on how the occurrence of a bleed in individuals on vitamin K antagonists (VKAs) impacts the risk of subsequent bleeds, and thromboembolic and ischemic events. Such information would help to inform treatment decisions following bleeds.

Objective To estimate the impact of bleeding events on the risk of subsequent bleeds, venous thromboembolism (VTE), stroke, and myocardial infarction (MI) among patients initiating VKA treatment for new-onset nonvalvular atrial fibrillation (NVAF).

Methods We conducted an observational cohort study using a linked Clinical Practice Research Datalink—Hospital Episode Statistics dataset. Among a cohort of individuals with NVAF, the risk of clinically relevant bleeding, VTE, stroke, and MI was compared between the period prior to the first bleed and the periods following each subsequent bleed. The rate and cost of general practitioner (GP) consultations, prescriptions, and hospitalizations were also compared across these periods.

Results The risk of clinically relevant bleeding events was observed to be elevated at least twofold in all periods following the first bleeding event. The risk of VTE, stroke, and MI was not found to differ according to the number of clinically relevant bleeding events. The rate and cost of GP consultations, GP prescriptions, and hospitalizations were increased in all periods relative to the period prior to the first bleed.

Conclusions The doubling in the risk of bleeding following the first bleed, taken alongside the stable risk of MI, VTE, and stroke, suggests that the risk–benefit balance for VKA treatment should be reconsidered following the first clinically relevant bleed.
Investigations of irradiation effects in crystalline and amorphous SiC
Authors: Cowen Benjamin J. , El-Genk Mohamed S. , Hattar Khalid , Briggs Samuel A.
Published: October 2019

The effects of irradiation on 3C-silicon carbide (SiC) and amorphous SiC (a-SiC) are investigated using both in situ transmission electron microscopy (TEM) and complementary molecular dynamics (MD) simulations. The single ion strikes identified in the in situ TEM irradiation experiments, utilizing a 1.7 MeV Au3+ ion beam with nanosecond resolution, are contrasted to MD simulation results of the defect cascades produced by 10–100 keV Si primary knock-on atoms (PKAs). The MD simulations also investigated defect structures that could possibly be responsible for the observed strain fields produced by single ion strikes in the TEM ion beam irradiation experiments. Both MD simulations and in situ TEM experiments show evidence of radiation damage in 3C-SiC but none in a-SiC. Selected area electron diffraction patterns, based on the results of MD simulations and in situ TEM irradiation experiments, show no evidence of structural changes in either 3C-SiC or a-SiC.
Energy harvesting with micro scale hydrodynamic cavitation-thermoelectric generation coupling
Authors: Gevari Moein Talebian , Ghorbani Morteza , Svagan Anna J. , Grishenkov Dmitry , Kosar Ali
Published: October 2019

In this study, energy harvesting with micro scale hydrodynamic cavitation-thermoelectric generation coupling is investigated. For this, three micro orifices with different geometrical dimensions are fabricated. The hydraulic diameter of the micro orifices are 66.6 μm, 75.2 μm, and 80 μm, while their length is the same (2000μm). Two different working fluids, namely water and Perfluoropentane droplet-water suspension, are utilized for cavitating flows in the fabricated micro orifices. The flow patterns at different upstream pressures are recorded using the high-speed camera system, and the experimental results are analyzed and compared. Thereafter, energy harvesting perspectives of cavitating flows are considered. The released heat from collapsing bubbles and the subsequent temperature rise on the end wall of the microchannel, which can be used as the source for the power generation, is calculated over time. Finally, a miniature energy harvesting system with cavitation system and thermoelectric generator coupling is presented. The maximum power corresponding to two different thermoelectric generators is estimated for with both working fluids and is compared with the required power to run miniature daily used electronics components.
Assessing density functional theory in real-time and real-space as a tool for studying bacteriochlorophylls and the light-harvesting complex 2
Authors: Schelter Ingo , Foerster Johannes M. , Gardiner Alastair T. , Roszak Aleksander W. , Cogdell Richard J. , Ullmann G. Matthias , de Queiroz Thiago Branquinho , Kümmel Stephan
Published: October 2019

We use real-time density functional theory on a real-space grid to calculate electronic excitations of bacteriochlorophyll chromophores of the light-harvesting complex 2 (LH2). Comparison with Gaussian basis set calculations allows us to assess the numerical trust range for computing electron dynamics in coupled chromophores with both types of techniques. Tuned range-separated hybrid calculations for one bacteriochlorophyll as well as two coupled ones are used as a reference against which we compare results from the adiabatic time-dependent local density approximation (TDLDA). The tuned range-separated hybrid calculations lead to a qualitatively correct description of the electronic excitations and couplings. They allow us to identify spurious charge-transfer excitations that are obtained with the TDLDA. When we take into account the environment that the LH2 protein complex forms for the bacteriochlorophylls, we find that it substantially shifts the energy of the spurious charge-transfer excitations, restoring a qualitatively correct electronic coupling of the dominant excitations also for TDLDA.
Finite obstacle effect on the aerodynamic performance of a hovering wing
Authors: Yin B. , Yang G. , Prapamonthon P.
Published: October 2019

The finite obstacle effect on the aerodynamic performance of a normal hovering wing is studied using the immersed boundary method. Phenomena of a two-dimensional wing hovering above, under, or on the side of a circular obstacle are presented. Parameters including obstacle size, distance, location, and flapping angle are investigated to study how the aerodynamic force and flow field are affected. The diameter of the obstacle ranges from 0.5c to 12c and the distance between the centroid of the wing and obstacle surface from 0.5c to 6c (c is the wing chord length). Previous observations of ground effects including force enhancement, reduction, and recovery occur similarly when the wing hovers above the obstacle of diameter greater than 2c. However, finite obstacles affect the aerodynamic performance differently when the size shrinks to a critical value. Force drops when the wing moves close and rises when moving away, opposite to the ground effect. As flapping angle amplitude increases, the force change tends to be consistent for different-sized obstacles. The top or side effect shows a different influence on the force change. Force monotonically increases as the distance decreases when the wing hovers under the obstacle. The side effect places a less important factor on the aerodynamic performance. All force changes under such circumstance are less than 13% referring to nonobstacle result. The gap between the leading or trailing edge of the wing and obstacle surface plays a significant role in the leading and trailing edge vortices generating, shedding, and pairing, which greatly affects the force change.
Differential evolution algorithm approach for describing vibrational solvatochromism
Authors: Kwac Kijeong , Cho Minhaeng
Published: October 2019

We model the solvation-induced vibrational frequency shifts of the amide I and amide II modes of N-methylacetamide in water and the nitrile stretch mode of acetonitrile in water by expressing the frequency shift as a polynomial function expanded by the inverse power of interatomic distances. The coefficients of the polynomial are optimized to minimize the deviation between the predicted frequency shifts and those calculated with quantum chemistry methods. Here, we show that a differential evolution algorithm combined with singular value decomposition is useful to find the optimum set of coefficients of polynomial terms. The differential evolution optimization shows that only a few terms in the polynomial are dominant in the contribution to the vibrational frequency shifts. We anticipate that the present work paves the way for further developing different genetic algorithms and machine learning schemes for their applications to vibrational spectroscopic studies.
Generation of boron ion beams by vacuum arc and planar magnetron ion sources
Authors: Bugaev Alexey , Frolova Valeria , Gushenets Vasily , Nikolaev Alexey , Oks Efim , Savkin Konstantin , Shandrikov Maxim , Vizir Alexey , Yushkov Anatoly , Kadlubovich Boris , Yushkov Georgy
Published: October 2019

Boron ions can be implanted not only in semiconductors such as silicon wafers but also in other materials and metal products, e.g., machine parts and tools, to increase their surface properties and therefore lifetime. The purity of boron ion beams for these purposes is not so critical as for semiconductor technologies. Here, we present experimental results on the generation of pulsed boron ion beams in vacuum arc and planar magnetron ion sources with pure boron and lanthanum hexaboride cathodes with emphasis on the mass-charge state composition of the ion beams.
Quasinormal Modes of Modified Gravity (MOG) Black Holes
Authors: Manfredi Luciano , Mureika Jonas , Moffat John
Published: October 2019

Black holes play a fundamental role in modern physics. These possess characteristic resonant frequencies, called Quasinormal Modes (QNMs), which are important in our understanding of the dynamics of astrophysical black holes. Quasinormal modes are single frequency modes dominating the time evolution of perturbations of systems which are subject to damping, either by internal dissipation or by radiating away energy. Due to the damping, the frequency of a quasinormal mode must be complex, its imaginary part being inversely proportional to the typical damping time. In general relativity, damping occurs even without friction, since energy may be radiated away towards infinity by gravitational waves.

In this thesis, the quasinormal modes for gravitational and electromagnetic perturbations are calculated in a Scalar-Tensor-Vector (STVG) Modified Gravity (MOG) spacetime. This theory is based on an action principle and postulates the existence of a vector field, while elevating the three constants of the theory to scalar fields. In the weak-field approximation, STVG produces a Yukawa-like modification of the gravitational force due to a point source. STVG has been used successfully to explain galaxy rotation curves, the mass profiles of galaxy clusters, gravitational lensing in the Bullet Cluster, and cosmological observations without the need for dark matter.

It is found that for the increasing model parameter α, both the real and imaginary parts of the QNMs decrease compared to those for a Schwarzschild black hole. On the other hand, when taking into account the 1/(1 + α) mass re-scaling factor present in MOG, Im(ω) matches almost identically that of GR, while Re(ω) is higher. These results can be identified in the ringdown phase of massive compact object mergers, and are thus timely in light of the recent gravitational wave detections by LIGO.