bluuebunny/crossref_metadata_2025 huggingface dataset:
Unsteady electro-osmotic flow of couple stress fluid in a rotating microchannel: An analytical solution
Authors: Siva Thota , Kumbhakar Bidyasagar , Jangili Srinivas , Mondal Pranab Kumar
Published: October 2020

In this work, we present the theoretical investigation of the transient rotating electro-osmotic flow of a couple stress fluid in a microchannel, through the Laplace transform technique. The analysis is dependent on the Debye–Hückel linear approximation for electrical potentials. The governing equations of the couple stress fluid are taken to address the flow field in a rotating environment. The mathematical formulation of these governing equations provides a system of ordinary differential equations, which are then solved to achieve analytical solutions for electrostatic potential, axial and transverse velocity distribution, and volumetric flow rate. A comparison was made for the present analytical solution with data available in the literature. There was excellent matching. The characteristics of different influential parameters on axial and transverse velocity distributions, volume, and angle flow rates are pictorially deliberated. The study reveals that the rise in the couple stress parameter accelerates the axial electro-osmotic flow velocity inside the electrical double layer.
Coherence preservation and electron–phonon interaction in electron transfer in DNA
Authors: Peralta Mayra , Feijoo Steven , Varela Solmar , Mujica Vladimiro , Medina Ernesto
Published: October 2020

We analyze the influence of electron–phonon (e–ph) interaction in a model for electron transfer (ET) processes in DNA in terms of the envelope function approach for spinless electrons. We are specifically concerned with the effect of e–ph interaction on the coherence of the ET process and how to model the interaction of DNA with phonon reservoirs of biological relevance. We assume that the electron bearing orbitals are half filled and derive the physics of e–ph coupling in the vicinity in reciprocal space. We find that at half filling, the acoustical modes are decoupled to ET at first order, while optical modes are predominant. The latter are associated with inter-strand vibrational modes in consistency with previous studies involving polaron models of ET. Coupling to acoustic modes depends on electron doping of DNA, while optical modes are always coupled within our model. Our results yield e–ph coupling consistent with estimates in the literature, and we conclude that large polarons are the main result of such e–ph interactions. This scenario will have strong consequences on decoherence of ET under physiological conditions due to relative isolation from thermal equilibration of the ET mechanism.
Shock waves generated by a pulsed surface sliding discharge in a supersonic airflow past a wedge
Authors: Liao Yu. , Mursenkova I. V. , Ivanov I. E. , Znamenskaya I. A. , Sysoev N. N.
Published: October 2020

An experimental study was made of the dynamics of shock waves developing from a localized channel of a nanosecond surface sliding discharge in supersonic airflows past a wedge in the shock tube with Mach numbers 1.16–1.47 at a density of 0.02 kg/m3–0.20 kg/m3. It is shown that a semi-cylindrical explosive-type shock wave is formed from the discharge channel in the low-density vortex zone behind the wedge. Numerical simulations of the resulting gas-dynamic flow are performed. The shadowgraphy images of shock waves after the discharge were compared with simulations of the flow field after an energy input near the wall in a supersonic flow. The energy input region in the simulations was set in accordance with the experimental results on the geometry of the discharge channel. Based on a comparison of experimental results and simulations, it is shown that shock waves are formed when a heat energy of 0.07 ± 0.04 J is released in the channel of localized discharge in supersonic airflows.
An electro-thermal computational study of conducting channels in dielectric thin films using self-consistent phase-field methodology: A view toward the physical origins of resistive switching
Authors: Koushan Foroozan S. , Kobayashi Nobuhiko P.
Published: October 2020

A large number of experimental studies suggest that two-terminal resistive switching devices made of a dielectric thin film sandwiched by a pair of electrodes exhibit reversible multi-state switching behaviors; however, coherent understanding of physical and chemical origins of their electrical properties needs to be further pursued to improve and customize the performance. In this paper, phase-field methodology is used to study the formation and annihilation of conductive channels, resulting in reversible resistive switching behaviors that can generally occur in any dielectric thin films. Our focus is on the dynamical evolution of domains made of electrical charges under the influence of a spatially varying electric field and a temperature, resulting in distinctive changes in electrical conductance.
The math behind epidemics
Authors: Hill Alison L.
Published: October 2020

A few simple metrics characterize outbreaks like COVID-19, but calculating them correctly is surprisingly tricky.
The polar Ras-like GTPase MglA activates type IV pilus via SgmX to enable twitching motility in
Myxococcus xanthus
Authors: Mercier Romain , Bautista Sarah , Delannoy Maëlle , Gibert Margaux , Guiseppi Annick , Herrou Julien , Mauriello Emilia M. F. , Mignot Tâm
Published: October 2020

Significance

The type IV pilus (Tfp) is a multipurpose machine found on bacterial surfaces that works by cycles of synthesis/retraction of a pilin fiber. During surface (twitching) motility, the coordinated actions of multiple Tfps at the cell pole promotes single cells and synchronized group movements. Here, directly observing polar Tfp machines in action during motility of
Myxococcus xanthus
, we identified the mechanism underlying pole-specific Tfps activation. In this process, the Ras-like protein MglA targets a novel essential Tfp-activator, SgmX, to the pole, ensuring both the unipolar activation of Tfps and its switching to the opposite pole when cells reverse their movement. Thus, a dynamic cascade of polar activators regulates multicellular movements, a feature that is likely conserved in other twitching bacteria.
Onset glottal stop deletion in Suva Rotuman
Authors: Fimone Wilfred
Published: October 2020

This paper studies onset glottal stop deletion in the speech of Suva Rotumans, Fiji. The speech of 18 speakers was analysed and seven factors were tested to identify their prediction on glottal stop deletion. The linguistic factors tested were preceding sound segment, grammatical class, syllable stress, and style, while the social factors were age, gender, and denominational affiliation. Results reveal a change in progress, but towards glottal stop retention. Younger Rotumans and older Rotuman women are deleting glottal stops less compared to middle-aged women and older men. The low incidence of deletion by younger speakers is most probably due to identity, language education in Rotuman, and their increased awareness of their role in preserving the language. Additionally, older women are deleting glottal stops less, which could be attributed to contact, identity, and their consciousness of the standard.
Research on high specific strength as-cast AlxNbTiVZr high entropy alloys
Authors: Xu Jinliang , Wang Tao , Lu Yongfa , Zhang Shannan , Wei Wenchao , Wang Chunyu
Published: October 2020

The effect of continuously varying aluminium with a low content ( x = 0.1–0.5) on as-cast AlxNbTiVZr high entropy alloys (HEAs) was studied. AlxNbTiVZr ( x = 0.1, 0.2) HEAs showed a single BCC phase, while some lamellar second phases precipitated along the grain boundaries in AlxNbTiVZr ( x = 0.3, 0.4, 0.5) alloys. With the increase in Al percentage, the compressive strength of AlxNbTiVZr HEAs increased from 1452 to 1667 MPa, whereas their ductility decreased from 19.40 to 6.15%. Notably, the AlxNbTiVZr HEAs showed both a higher specific yielding strength and considerable plastic strain than other Nb-Ti-V-X-Y HEAs and commercial Mg-, Ti-, and Ni-based alloys. Finally, the fracture morphologies of AlxNbTiVZr ( x = 0.1–0.2) HEAs showed some features of compression ductility.
Characterisation of nickel–aluminium bronze powders produced by the planar flow casting method
Authors: Öztürk Sultan , Sünbül Sefa Emre , Metoğlu Abdurrahim , Önal Suat , İçin Kürşat
Published: October 2020

CuAl10Ni5Fe4 alloy powders were successfully produced using the planar flow casting method, known as the continuous ribbon production process. Cooling the textured wheel to -5 ºC resulted in a much finer microstructure in comparison to uncooled wheel powders. The microstructure of the powders, in case of the cooled wheel, consisted of β′ martensite, which resides inside the colonies, and proeutectoid α phase at colony boundaries. The martensite start and finish temperatures for uncooled wheel powders were obtained as 221 ºC, and 174 ºC, respectively. The Ms and Mf temperatures for cooled wheel powders were measured as 207 ºC, and 135 ºC, respectively. It is observed that the magnetic properties of the produced powders change with the amount of β′ martensite.
The Development of a Prison Mental Health Unit in England: Understanding Realist Context(s)
Authors: Dyer Wendy , Cassidy Kathryn , Ridley Louise , Biddle Paul , McClelland Norman , Brandon Toby
Published: October 2020

A pragmatic solution for the provision of care for prisoners with serious mental illness, who are often subject to delays in hospital transfer, is the creation of specialist prison units. This paper analyses the development of a prison unit in England for prisoners with ‘serious mental illness’. The unit was developed within over-lapping health and justice contexts, including expectations, pressures and priorities, which impacted on the outcomes expected and achieved. The methodology included attendance at Steering group meetings, analysis of a minimum dataset, and interviews with key stakeholders. A number of key sites of contestation are analyzed including: admission criteria; aims; activities; staffing; the physical environment; and discharge.
Femtosecond fragmentation of CS2 after sulfur 1s ionization: interplay between Auger cascade decay, charge delocalization, and nuclear motion
Authors: Grånäs O , Mocellin A , Cardoso E S , Burmeister F , Caleman C , Björneholm O , de Brito A Naves
Published: October 2020

We present a combined experimental and theoretical study of the fragmentation of molecular CS2 after sulfur 1s Auger cascade decay, consisting of electron–multi-ion coincidence spectra of charged fragments and theoretical simulations combining density functional theory and molecular dynamics. On the experimental side, a procedure for a complete determination of all sets of ions formed is described. For many of the fragmentation channels, we observed a higher charge in one of the sulfur atoms than the other atoms. Based on these observations and the theoretical simulations where the time scale of the nuclear motion and decay is taken into account, we propose that KLL Auger decay after the 1s core hole creation, via 2p double hole states, results in highly charged and strongly repulsive states with one localized core hole. These localized core holes are sufficiently long-lived that some will decay after fragmentation of the molecular ion, thereby efficiently impeding charge exchange between the fragments.
Surface charge accumulation and decay in electrospray printing
Authors: Zhu Yaqun , Chiarot Paul R
Published: October 2020

In electrospray printing, the accumulation of electric charge on the target substrate plays an important role in governing the structure of the deposit. To better understand the effect of charge, we report on the use of two methods to measure the rate of charge accumulation and decay on dielectric substrates targeted with electrospray: ohmic dissipation (OhmD) and electrostatic force microscopy (EFM). The OhmD measurements were conducted on an assembly consisting of two different target materials: nylon and glass. The charge accumulation and decay were governed by the electrospray operating conditions, including spray time, flow rate, solution electrical conductivity, and the dielectric properties of the target. We found that the accumulation of charge influenced the electrospray mode in a transient way by decreasing the electric field strength between the emitter and the substrate. To complement the OhmD measurements, the charge accumulation and decay were measured at discrete spots on a silicon substrate coated with photoresist using EFM. These highly spatially resolved measurements revealed that while the electric charge was not distributed uniformly across the substrate, it still followed a similar decay trend as that obtained using the OhmD measurement. The results reported here will assist in understanding and predicting the structure of a deposit printed using electrospray.
Understanding the effects of off-state and hard-switching stress in gallium nitride-based power transistors
Authors: Modolo Nicola , De Santi Carlo , Minetto Andrea , Sayadi Luca , Sicre Sebastien , Prechtl Gerhard , Meneghesso Gaudenzio , Zanoni Enrico , Meneghini Matteo
Published: October 2020

The aim of this paper is to improve the understanding of gallium nitride (GaN) high electron mobility transistors (HEMTs) submitted to hard switching operation, with focus on the hot-electron phenomena. This is becoming a hot-topic both for the scientific community and for the industry. The analysis is carried out through a cross-comparison of three different experimental techniques: conventional Pulsed-IV characterization, a novel pulsed-drain current transient (P-DCT) method, and a custom-developed hard switching test protocol. Hard switching analysis was performed through a novel system able to test the device in hard-switching conditions with an unprecedented turn-on slew-rate of 25 V ns−1 on-wafer level. This allows μs to investigate the impact of hard switching in terms of (i) locus trajectory, (ii) dissipated power, and (iii) dynamic

R

on

increase. Furthermore, the accumulation of switching stress is assessed by repeating the experiment with increasing frequency, from 1 kHz to 100 kHz. The extensive cross-analysis offers a novel insight on the degradation mechanisms occurring in power GaN HEMTs. The results collected within this paper allow: (1) to evaluate the dynamic behavior under both soft- and hard-switching stress, thus differentiating off-state and semi-on-state stress; (2) to pinpoint hot-electrons as the main cause of the current collapse observed in semi-on; (3) by comparing the results obtained from P-DCT and Hard Switching Analysis we demonstrate that the hot-electron trapping is a very fast process which can happen in few ns. The related trapping and de-trapping kinetics are investigated in detail. The results described within this paper provide novel insight on the important role of hot-electrons in the dynamic

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increase during hard switching operations.
Research on Surrounding Rock Deformation Prediction During Underground Excavation of Hydropower Station Based on Prototype Monitoring
Authors: Zhang Tengjiao , Ling Qi , Hu Bo , Li Guangyi , Guo Mingqun
Published: October 2020

This paper proposes an improved gray model of equal dimensional innovation based on time-varying parameters and the gray characteristics of small sample and poor information of the safety monitoring data during underground cavern construction, so as to predict and judge the deformation of surrounding rocks in underground caverns and to obtain relatively reliable results in the analysis of uncertain systems. Under certain conditions, the improved gray model of equal dimensional innovation based on time-varying parameters can be used to predict the deformation of surrounding rocks during the excavation of underground caverns, thereby providing mathematical analysis tools for safe construction.
Design of 20 ft Multifunctional Platform Container
Authors: Yunze Yang , xia Yuan , Junhua Chen
Published: October 2020

In view of the problems of high transportation cost, low loading and unloading efficiency, poor reinforcement in the transportation of glass and coiled steel, combined with the transportation of tubular goods such as aluminum rods and logs, a safe, stable and recyclable 20ft multifunctional platform container is designed, which is based on the “Code for Steel Structure Design”. The overall structure of the 20ft multifunctional platform container consists of two parts: the bottom “platform” and the upper “A-frame”, which has three functions of loading coiled steel, tubular goods and bare glass. In addition, the feasibility of loading cargo on platform container was checked in accordance with the requirements of the “Rules for Loading and Reinforcement of Railway Cargo”. The platform container is constructed and carried on the finite element analysis by using the software named SolidWorks, its stress analysis and displacement analysis results are in line with relevant regulations. The designed multifunctional platform container can improve the loading and unloading efficiency of glass and coiled steel transportation, save loading reinforcement materials and transportation costs, having a promising market prospect.
Research on Railway Traffic Conflict Management Method in Onboard-centered Train Control System
Authors: Xiaonan Zhao , Yong Zhang
Published: October 2020

In order to ensure the safety of train operation and improve the ability of train to deal with emergencies independently, this paper classifies and defines the possible conflicts in railway operation, and proposes a method of train conflict prediction and collaborative resolution. The feasibility of this method is verified by the establishment of timed automata model for different operation scenarios. Finally, a prediction method of station level resource occupation conflict is proposed, which is verified by a simulation example.
Research on Supply and Demand Matching of Urban Public Transport Based on IC Card and GPS Data
Authors: Sun Qiuxia , Hao HE , Sun Lu
Published: October 2020

A research method to establish the matching degree of supply and demand of bus stations by using Moran’s I, which describes the spatial agglomerating feature, was proposed based on IC card and GPS data mining. The bus boarding station information was deduced by the time matching method and the passenger demand of the station was represented by the passenger flow in the station, the vehicle data from GPS data were selected as the bus service supply, the matching situation of bus supply and demand in different time periods in the whole city was researched, the degree of station imbalance was identified, to assist the bus system to optimize supply. Take Qingdao city as an example, the empirical research indicated that: It was concluded that the demand and supply of the bus service in the research area matched well on the whole, and the supply of buses at the bus stations basically met the travel demand of residents. According to the LISA diagram of station clustering distribution, the stations with a mismatch of supply and demand in the area were identified through spatio-temporal difference analysis, and the mismatch was relatively more obvious in regions where a small number of stations were located.
Research on anti-freezing and thermal insulation measures of tunnel in cold area
Authors: Zhang Lidong , Cao Yanfeng , Xiao Shilai , Guo Hongyan , Cao Peng
Published: October 2020

To solve the problem of freezing damage in tunnels in cold areas, based on the investigation and analysis of the existing tunnel insulation measures in cold regions, the Wunvfeng Tunnel is used as a supporting project. First, indoor tests are conducted to analyze the insulation performance, insulation effect and influencing factors of the cold insulation layer. The moisture-proof performance has a great influence on the cold-proof and thermal insulation effect. From the test results, it can be seen that when the thermal insulation layer is immersed in water, its thermal insulation performance decreases rapidly. The temperature behind the thermal insulation layer decreases rapidly with time, and the temperature quickly drops below zero without convergence, trend, the loss of cold-proof and thermal insulation performance. Then, through numerical simulation, the thermal insulation effect of different insulation layer laying methods (intermediate method, double layer method and surface method) was compared and analyzed, and it was concluded that under the same thickness of insulation layer, the better insulation layer laying method was surface method. It also shows that the closer the insulation layer is to the interface between the surrounding rock and the ambient air, the better its insulation effect.
Deimos rendezvous mission analysis and orbital design based on the Mars survey
Authors: Wang Zuopeng , Xie Xin , Xu Ming
Published: October 2020

Imaging the Martian surface with a sun-synchronous orbit is a fundamental task of most current Mars exploration programs. In this paper, the Mars-Deimos multi-target orbit design is carried out for a small spacecraft that uses the spacecraft’s spare spacecraft to achieve a carrier launch. Due to the 92.7° inclination of the working orbit of the main detector, Deimos detection is carried out by means of a swept intersection: The working orbit is designed for a large elliptical orbit with a critical inclination of 116.6° and a lifetime of 280 Deimos intersections. Unlike the Viking-1 orbital control, which is used to suppress arch line drift, the working track maintenance strategy designed in this paper is used only to eliminate tangential drift, and keep the consumption and frequency reducing with increasing orbital accuracy. Finally, the working orbit was analysed for its imaging, illumination and metrological/numeric transmission conditions and the spatio-temporal distribution of occult events between the small spacecraft and the main probe. Deimos imaging plan is used in the pre life descent phase, and Mars surface imaging plan is used in the post life ascent phase. The results of the analysis indicate that the full use of the carrier margin for small spacecraft launch can be carried out, for example, imaging the surface of Mars and Centaur, and covering the earth’s atmosphere with the main detector. The working orbit and orbital control strategies are designed to take into account the impact of orbital determination errors and main actuators (both short-period and long-period items, etc.) on the Deimos rendezvous, and to have engineering implementation conditions.
The detection method of positioning accuracy in CORS system exists
Authors: Yinghao Li , Chunlei Guo , Yang Zhao , Chuanyun Yue
Published: October 2020

The positioning accuracy detection of CORS system is an essential link before it is put into market. However, the location accuracy detection method does not take into account the correlation between the comprehensive environment around the detection point and the external coincidence accuracy, so the method is not rigorous and scientific. This paper proposes a method based on nonparametric statistics, which can verify the correlation between the comprehensive environment around the detection point and the external coincidence accuracy from a mathematical point of view, and then it is incorporated into the traditional positioning accuracy detection method, and is verified by a CORS system. The results are satisfactory, which proves that this method is very effective in compensating the integrity of CORS positioning accuracy detection method.
Optimal signal timing design for the intersection of Dazhi Street and Hexing Road
Authors: Liu Liqiang , Yin Yuexiu , Tian Na , Guo Yu
Published: October 2020

The phenomenon of intersection congestion has become a major problem in the city. Based on the intersection of Hexing road and Dazhi street, the delay phenomenon of Urban Road intersection is optimized. The intersection of Hexing road and Dazhi street is seriously delayed. In order to improve the road capacity of the intersection and reduce the delay of the intersection, the traffic characteristics parameters of the intersection during peak period are obtained, and the traffic capacity and intersection service level of the signalized intersection are analyzed and calculated. Based on the study of the basic content and research methods of signal timing at signalized intersections, the microscopic simulation software VISSIM was used to improve the traffic control scheme with serious delays at intersections and low urban road capacity, the simulation optimization is carried out by changing the signal timing and resetting the channelization scheme of intersection. Meanwhile, the signal timing of intersection is optimized. The results show that the traffic capacity of the intersection has been greatly improved by VISSIM simulation.
Modeling and optimizing the bus operation based on the bus app
Authors: Xu Kunmiao , Cui Shanshan , Zhou Peng
Published: October 2020

Bus congestion is a common phenomenon in the process of bus operation, which will worsen bus service to a certain extent and further affect residents’ travel choice. To cope with this problem, this paper proposed a new passenger arrival model taking into account the usage of bus app, which represents the dynamic passenger arrival distribution and where bus capacity constraints are explicitly considered. First, a bus propagation model was developed to carry out theoretical analysis of the bus bunching problem. Afterwards, the new passenger arrival rule, namely, triangular passenger arrival rule, was obtained by fitting the researching data of the passengers who used “bus is coming” app. Finally, under this law of arrival, a new enhanced bus propagation model was developed. By comparing the simulated results, we found that the occurrence of bus bunching was reduced dramatically and the operation of the bus was more stable, which indicated the superiority of the triangular passenger arrival rule.
Distribution Route Optimization of Electric Vehicles
Authors: Wang Heng , Ke Hang , Zhao Zhiqiang , Li Wei , Xu Yan
Published: October 2020

From the perspective of low carbon logistics, we take into account the environmental costs caused by the carbon emissions of battery electric vehicles. In addition, according to the customer’s certain requirements for the delivery time during the actual delivery process, this paper introduces the penalty cost of the time window, thus constructing a delivery route optimization model with the goal of minimizing the total delivery cost. Then, this problem is solved by using the Ant Colony Algorithm. Finally, the case design is used for empirical analysis.
Research on induction signal control method of queuing length
Authors: Tian Na , Yin Yuexiu , Liu Liqiang
Published: October 2020

This paper aims at the problems of traditional induction signal control. By comparing the advantages and disadvantages of other timing signal control methods and induction signal control methods, an induction signal control method based on queuing length is proposed. The signal setting method of induction signal control method based on queuing length is analyzed in combination with the characteristics of queue length change and traffic flow. The method presented in this paper is introduced to optimize the length of the green light in the various phases of the previous period, the number of vehicles and the length of the queue, to predict the average head time distance and the queue length of the next cycle, so as to calculate the green light time and the period length of the next cycle of the intersection. At last, VISSIM simulation software is used to compare and analyze the traffic efficiency of induction signal control and traditional induction signal control based on queuing length, and verify the adaptability, feasibility and effectiveness of the scheme.
Mining the Value Characteristics of One-Way Car-Sharing Users Based on Empirical Data
Authors: Mi Xue , Wang Ying-Qi , Xie Dong-Fan
Published: October 2020

Car-sharing has been emergent in many cities all over the world due to the environmental sustainability and the diverse service for users. However, the huge investment and the long payback period hinder the development of car-sharing. To this end, this study attempts to mine the value of car-sharing users in terms of empirical data, aiming to provide suggestions for companies to enhance user management. Based on the order data of a car-sharing company, several indicators are defined. On the basis, the users are divided into three categories, namely high-value users, low-value users and potential users. Furthermore, with the proposed indicators and the personal attributes, a prediction model is developed based on random forest method to predict the category of users in advance. The results show that with the observation period of 7 weeks, the long-term value type of a user can be predicted with accuracy of more than 80%.
Short-term Passenger Flow Prediction for Urban Railway Transit Based on Change-point Model
Authors: Yao Enjian , Chen Chuanyu , Lu Muyang , Zhou Ying
Published: October 2020

For short-term passenger flow in urban railway transit has the characteristics of nonlinear distribution, a combined forecasting model based on variable-point model and neural networks model is proposed. First, the Pettitt method, the optimal segmentation algorithm, the BG segmentation algorithm(BGSA) and the wavelet analysis method are used to detect the change point of the passenger flow sequence at the memorial hall station, identify the change point of the passenger flow curve and divide the interval, and the passenger flow is predicted and verified by using the Multilayer neural network (MLP) and the radial basis function neural network (RBF). The results show that the wavelet analysis-RBF combined model based on change point detection has the root mean square error of 24.20 and the mean absolute percentage error of 3.52%. Compared with the single neural network model, it improves forecasting accuracy.
Analysis on the Development Orientation of the Golden Channel of Passenger Roll Transportation in Qiongzhou Strait under the New Era
Authors: Song Gao
Published: October 2020

Combined with the favorable situation of passenger roll transportation in Qiongzhou Strait in the new era, following the guidance of liner policy and the macro market demand closely, the passenger roll transportation in Qiongzhou Strait is defined as the “golden channel” serving the national economy and people’s livelihood, which is judged as the economic development channel, tourism support channel, agricultural and trade transport channel, residents’ communication channel, green travel channel and combat readiness support channel, and is also committed to promoting the construction of modern, scientific and reasonable comprehensive passenger and cargo transportation channels, to provide high-quality development services for the Qiongzhou Strait water passenger and passenger transportation.
Study on Conservation and Reuse Planning of Tianjin Airport Historic Buildings
Authors: Hong Lv , Yu Wang
Published: October 2020

With the continuous development of Chinese civil aviation industry, the airport construction facilities built in different periods of time have suffered from the dilemma of idle, abandoned or even demolished, so it needs to be protected and utilized from the perspective of industry. Taking the historical buildings of Tianjin Airport as an example, this paper first expounds the development course of Tianjin Airport construction, and then delimits the protection scope and functional partition of the airport historical buildings by means of field survey and textual research, and then the AHP and Delphi method are used to evaluate the comprehensive value of the historic buildings of Tianjin Airport. Finally, according to the evaluation results, it is proposed to apply to the overall protection planning of the historic buildings of Tianjin Airport.
The impact of Beijing-Tianjin-Hebei high-speed rail network on regional tourism and hotel industry
Authors: Bingsong Zhang
Published: October 2020

This paper analyzes the impact of high-speed rail (HSR) on regional tourism from the perspective of per capita hotel consumption and regional hotel industry market power in the Beijing-Tianjin-Hebei region. This paper shows that the construction of HSR is not conducive to the coordinated development of the inter-regional hotel industry, especially when there is a large gap in economic development and tourism competitiveness between the two places, the siphoning effect of HSR will be very obvious. HSR may become a factor that restricting the development of hotel industry in economically backward areas.
Solving Multiple Distribution Center Location Allocation Problem Using K-Means Algorithm and Center of Gravity Method Take Jinjiang District of Chengdu as an example
Authors: Cai Chunling , Luo Yong , Cui Yuehong , Chen Feng
Published: October 2020

In the logistics system, logistics nodes play an important role. The centre-of-gravity method is one of the most basic methods in solving the problem of single facility location. The thesis first uses the K-means clustering algorithm to divide the demand points into k clusters, and the k value is selected by the elbow method. Then, the k clusters are regarded as a single facility location problem and analyzed by the center of gravity method. In practical applications, the discrete model analysis can be cited to further obtain the optimal solution.
Predictive Maintenance using Machine Learning Based Classification Models
Authors: Chazhoor Anisha , Mounika Y , Vergin Raja Sarobin M , Sanjana M V , Yasashvini R
Published: October 2020

Machine learning facilitates predictive maintenance due to the advantages it holds over traditional methods of maintaining semi-conductor devices such as preventive and breakdown maintenance. Several predictive models using machine learning on the Semiconductor Manufacturing process dataset (SECOM) will be applied in this paper. The dataset contains the information related to semiconductor manufacturing process, with the attributes corresponding to signals collected from semiconductor devices. Due to the high-dimensionality of the data and class imbalance problem in the SECOM dataset, it poses several challenges related to data pre-processing, which is an essential step incorporated in this work while applying various machine learning models. Comparison and analysis of various predictive machine learning classification models were carried out based on the performance metrics like, accuracy and Receiver Operating Characteristic (ROC) curve.
Passive flow control strategies for low Reynolds number airfoils
Authors: Rajesh Senthil Kumar T , Kolluri Mohini Priya , Gopal Subramaniyan V R , Sripathi A D
Published: October 2020

This study focuses on ameliorating the aerodynamic performance of an airfoil in low Reynolds number regime by implementing a passive flow control technique to suppress the effects created by the bubble bursting which holds significance in enhancing the aerodynamic performance of SUAVs which fall under this regime. A numerical study is conducted for the flow over E387 airfoil at a Reynolds number 105 to investigate the effects of the implementation of the passive flow control configuration on the laminar separation bubble dynamics. It is noted that orientation, thickness, inlet location, and configuration of the passive flow control passage had imposed significant effects on lift and drag coefficients generated by the airfoil. A significant drag reduction was achieved when the airfoil is implemented with a slot oriented at 30° that has a converging exit which resulted in the rise of the airfoil’s aerodynamic efficiency.
Applications of marketing flexibility in manufacturing and service sectors
Authors: Gopakumar Kavya , Suresh M.
Published: October 2020

Most businesses are now faced with extreme pressures that relate to advances in globalization, rapidly evolving technology, as well as changes in the demands and behaviors of consumers. Marketing flexibility is therefore the key strategy for a business which helps to ensure customer satisfaction, achievement of success, differentiation among the competitors and superior performance under the environmental fluctuations. Unlike the plenty of studies pertaining to manufacturing and operational flexibility, there are only little efforts made to investigate and research on the topic marketing flexibility. Hence the concept of marketing flexibility is relevant for the prevailing situation and moreover it is undoubtedly an important topic for researchers that help in investigating firm performance and the sustainability of competitive advantage. This article presents an extensive study about marketing flexibility and its practical as well as theoretical applications through various approaches.
Optimising the Parameters and Increasing the Hardness of Duplex Stainless Steel by Annealing Process in Valve Manufacturing Industries
Authors: Varun Kumar T. , Karthick K. , Dhanushkaran K. , Jagadeesh D.
Published: October 2020

Duplex stainless steels (DSS) are designed to have a phase assemblage consisting of approximately 50% austenite and 50% ferrite. Such an assemblage makes these materials very attractive by providing an excellent combination of high hardness, toughness, and corrosion resistance. This project discuss about the increasing of hardness in duplex stainless steel (DSS), by suitable annealing process. Increasing of austenite increases the hardness of the material and the increasing of ferrite increases the ductile nature of the material. It is too crucial to obtain the suitable result by suitable match of annealing process. Thus the Design of Experiments were done and heating temperature of 1240°C with a holding time of 4.5hrs and cooled to a temperature of 1043.9°C provides the maximum hardness value of 311.235 BHN.
Optimal design and experimental investigation of the material-nanostability and deformation behaviour of Al-5.78Zn-1.45Cu-2.49 Mg, Al-5.6Zn-2.5Mg-1.6Cu and Al-Mg-0.6Si alloys under cyclic-loading for ultra-precision structural applications
Authors: Sharma Shubham , Singh Jujhar , Aggarwal Vivek , Sharma Shalab , Sharma Abhinav , Narayan Ram
Published: October 2020

This paper presents the design and construction of a new simple test facility for the investigation and testing of the deformation behaviour of material properties, namely plastic monolithic, inelastic, elastic and spring joints under cyclic loadings. Test samples were prepared in various machining directions (orthogonal and longitudinal) of Al-5.78Zn-1.45Cu-2.49 Mg, Al-5.6Zn-2.5Mg-1.6Cu and Al-Mg-0.6Si aluminium alloys. As a pulling force for sample deformation, an electromagnet unit was used. The test load range was between 0.2N to 200N, increased by a programmable factor of 1.1-1.4 for a train time of 900s. Two capacitive sensors and interferometers sensors mounted at different sample locations were used to test the sample deformation with and without loading. In a temperature-stable housing that offers isothermal conditions, the overall measuring machine is integrated. The calculated parameters include plastic and inelastic deformation.
An experimental study of wire breakage frequency on different electrodes during WEDM of Inconel-722
Authors: Aggarwal Vivek , Singh Jujhar , Sharma Shubham , Garg Harish K. , Sharma Abhinav , Singh Gursharan , Parshad Jwala
Published: October 2020

Inconel 722 is a nickel-based superalloy that holds high strength and impervious to oxidation and corrosion at high temperatures. Wire electrical discharge machining (WEDM) was investigated as a superior alternative to conventional machining methods for intricate and complex shapes for materials containing more strength. However, these wire electrodes also undergo breakage during WEDM of Inconel 722 which unquestionably diminishes the efficiency of machining process, and accuracy. Therefore, this work is an effort to investigate and understand the phenomenon of wire breakage in relation to the combination set of Inconel 722 and three wire electrodes which are plain brass-wire, diffused brass-wire and zinc-covered metal wire. An experimental study was carried out to check the effect of six machining parameters viz. Ton, Toff, SV, IP, WF and WT on the frequency of wire breakage. Results demonstrate that zinc-covered metal wire has low breakage recurrence according to all the parameters of the process examined. It has also determined the optimal range of process-parameters under which zinc-coated brass-wire can be used to achieve effective machining.
Employees stress level assessment: a case of apparel industry
Authors: Suresh M. , Yuvaprasanth R. , Arun Ram Nathan R.B. , Amarnath K.
Published: October 2020

The assessments of employees stress level in garment industry gains vital importance to improve the efficacy of employees. Fuzzy methods are more appropriate than the conventional methods for assessment of stress level. The study demonstrates an application of a multi-grade fuzzy approach to measure employees stress level. This is the first time that the employees stress level assessment framework has been developed in the garment industry sector. Through literature review and expert opinions, sub-factors, factors and enablers of employees stress in workplace were identified and a conceptual model was developed. This study suggests that stress level assessment is essential to identify the current stress level of employees in workplace. This would help the garment industries to reduce its stress level further. In this study the stress level was found to be 4.74; which indicated the case company employees stress level is fair. Finally, the high stress sub-factors were identified to point the way for further improvements.
Investigation to Enhance the Performance of Computer Processor Cooling System
Authors: Gayathri Prasad P. , Prasad Chilamkurti L.V.R.S.V. , Santarao K
Published: October 2020

In the recent past, cooling via thermoelectric technology has arisen to be as one of the capable cooling technology which helps in lowering the energy intake in a device. In this study, the performance enhancement of cooling system for the computer processor using thermoelectric cooler is investigated. An open loop cooling system was taken into consideration, where the main parameters are focused on computer load conditions, temperature carried by nanofluid or output temperature of nanofluid at water block and heat flux. The thermoelectric cooler (TEC) made of Bismuth Telluride (BiTe3) material for pn junctions is used with Delta Tmaxof 67°C in this analysis to extract the heat from processor. The Aluminium Oxide (Al2O3) and copper oxide (CuO) ranging from 40nm - 50nm size dispersed in distilled water with various volume concentrations were used for dissipation of heat from the hot surface of the TEC. Liquid flow is varied from 0.1LPM - 0.9LPM. Results demonstrate that by maintaining the lower Delta Tmax value, higher Coefficient of performance (COP) is achieved. There is a considerable reduction in operating temperature of processor when using the nanofluids. Both the nanofluids exhibited higher thermal conductivity on comparing with base fluids. The enhancement observed in output temperature is about 15°C to 20°C by using nanofluids. Higher the flowrate used higher the heat flux generated.
Optimization of Al-SiC-MW CNT metal composite by W-EDM using Taguchi method
Authors: Parswajinan C. , Vijaya Ramnath B. , Aiswarya V , Aswini Subhatra M , Rajesh S. , Sriram J.
Published: October 2020

EDM process is primarily used in machining of Al6061 metal matrix composite reinforced with silicon carbide (SiC) and carbon nano-tube (CNT). This process can be used to measure the Metal Removal Rate (MRR), Tool Wear Rate (TWR) and Surface Roughness (SR) of the work piece material. Using Taguchi’s parameter design, significant machining parameters affecting the performance of the process such as discharge current, pulse ON time and duty cycle are the input parameters. The performance measure for each combination of the parameters has been taken. In this work, the MRR, TWR and SR for each combination have been estimated. The results obtained are tabulated. The study demonstrates that the EDM process parameters can be adjusted to do better MRR, TWR and SR by optimizing the parameters using grey relational analysis (GRA).
Effects of trace Ce addition on critical cooling rate and Ti (CN) precipitation of ultra high strength steel plate
Authors: Gao Zhiguo , Xu Liujie
Published: October 2020

It is well-known that issues always occur for local non-hardenability of 1.5 GPa ultra-high strength steel plates during conventional hot forming processes, once the thickness of the plates is more than 2.5 mm. To resolve the issues, our recent research suggests that adding cerium during metallurgical processes is a prospective approach. This paper adopted a novel process to prepare 1.5 GPa ultra-high strength steel plates using a 25 kg smelting furnace. The research team investigated the effects of trace cerium addition on critical cooling rates characterizing the hardenability for the examined steel plates through measuring experimented continuous cooling transformation curves. The results showed the critical cooling rate of the investigated steel plate was about 10 °C s−1 only, which was at least 60% lower than that of traditional 1.5 GPa ultra-high strength steel plate. Cerium addition suppressed the diffusion of Ti atoms in the Fe matrix and improved Ti (CN) precipitation on the matrix of bcc Fe. This paper revealed that cerium addition substantially reduced critical cooling rates of 1.5 GPa ultra-high strength steel plate and significantly improved the hardenability of the processed steel plates.
Insight into the law and mechanism of selective oxidation of Q&P steel under different annealing parameters
Authors: Zhou Dayuan , Li Mian , Mi Zhenli , Jiang Haitao , Wu Yanxin
Published: October 2020

In order to investigate the law and mechanism of selective oxidation of Quenching and Partitioning (Q&P) steel under different annealing parameters, the sensitivity of alloy elements added in Q&P steel to the annealing parameters was explored. Galvanizing experiments of QP steel were carried out at different annealing temperatures(770 °C and 730 °C) and different holding times(180 s and 300 s). The concentration change of selective oxidation element and the alloying element distribution in the coating were analyzed by Glow Discharge Optical Emission Spectrometer (GDOES), the morphology of surface oxides and inhibition layer were observed by Scanning Electron Microscope (SEM). The results showed that higher annealing temperature(770 °C) and longer annealing time(300 s) could both increase the concentration of Mn and Si on the surface of Q&P steel, improve the oxidation degree of steel surface, thin the inhibition layer, and lead to more leakage plating and deterioration of surface coating quality. The Mn depth profiles showing a parabolic trend and reaching its maximum value at about 20 nm below the surface, while the concentration of Si gradually decreases from the surface to the interior. The selective oxidation of Si and Mn are more sensitive to the annealing temperature than the annealing time.