bluuebunny/crossref_metadata_2025 huggingface dataset:
Stress-Dependent Elasticity of TiAlN Coatings
Authors: Hans Marcus , Patterer Lena , Music Denis , Holzapfel Damian M. , Evertz Simon , Schnabel Volker , Stelzer Bastian , Primetzhofer Daniel , Völker Bernhard , Widrig Beno , Eriksson Anders O. , Ramm Jürgen , Arndt Mirjam , Rudigier Helmut , Schneider Jochen M.
Published: January 2019

We investigate the effect of continuous vs. periodically interrupted plasma exposure during cathodic arc evaporation on the elastic modulus as well as the residual stress state of metastable cubic TiAlN coatings. Nanoindentation reveals that the elastic modulus of TiAlN grown at floating potential with continuous plasma exposure is 7%–11% larger than for coatings grown with periodically interrupted plasma exposure due to substrate rotation. In combination with X-ray stress analysis, it is evident that the elastic modulus is governed by the residual stress state. The experimental dependence of the elastic modulus on the stress state is in excellent agreement with ab initio predictions. The macroparticle surface coverage exhibits a strong angular dependence as both density and size of incorporated macroparticles are significantly lower during continuous plasma exposure. Scanning transmission electron microscopy in combination with energy dispersive X-ray spectroscopy reveals the formation of underdense boundary regions between the matrix and TiN-rich macroparticles. The estimated porosity is on the order of 1% and a porosity-induced elastic modulus reduction of 5%–9% may be expected based on effective medium theory. It appears reasonable to assume that these underdense boundary regions enable stress relaxation causing the experimentally determined reduction in elastic modulus as the population of macroparticles is increased.
Advanced Markov-Based Machine Learning Framework for Making Adaptive Trading System
Authors: Rundo Francesco , Trenta Francesca , Di Stallo Agatino Luigi , Battiato Sebastiano
Published: January 2019

Stock market prediction and trading has attracted the effort of many researchers in several scientific areas because it is a challenging task due to the high complexity of the market. More investors put their effort to the development of a systematic approach, i.e., the so called “Trading System (TS)” for stocks pricing and trend prediction. The introduction of the Trading On-Line (TOL) has significantly improved the overall number of daily transactions on the stock market with the consequent increasing of the market complexity and liquidity. One of the most main consequence of the TOL is the “automatic trading”, i.e., an ad-hoc algorithmic robot able to automatically analyze a lot of financial data with target to open/close several trading operations in such reduced time for increasing the profitability of the trading system. When the number of such automatic operations increase significantly, the trading approach is known as High Frequency Trading (HFT). In this context, recently, the usage of machine learning has improved the robustness of the trading systems including HFT sector. The authors propose an innovative approach based on usage of ad-hoc machine learning approach, starting from historical data analysis, is able to perform careful stock price prediction. The stock price prediction accuracy is further improved by using adaptive correction based on the hypothesis that stock price formation is regulated by Markov stochastic propriety. The validation results applied to such shares and financial instruments confirms the robustness and effectiveness of the proposed automatic trading algorithm.
Robust Cochlear-Model-Based Speech Recognition
Authors: Russo Mladen , Stella Maja , Sikora Marjan , Pekić Vesna
Published: January 2019

Accurate speech recognition can provide a natural interface for human–computer interaction. Recognition rates of the modern speech recognition systems are highly dependent on background noise levels and a choice of acoustic feature extraction method can have a significant impact on system performance. This paper presents a robust speech recognition system based on a front-end motivated by human cochlear processing of audio signals. In the proposed front-end, cochlear behavior is first emulated by the filtering operations of the gammatone filterbank and subsequently by the Inner Hair cell (IHC) processing stage. Experimental results using a continuous density Hidden Markov Model (HMM) recognizer with the proposed Gammatone Hair Cell (GHC) coefficients are lower for clean speech conditions, but demonstrate significant improvement in performance in noisy conditions compared to standard Mel-Frequency Cepstral Coefficients (MFCC) baseline.
Applications of Blockchain Technology in Medicine and Healthcare: Challenges and Future Perspectives
Authors: Siyal Asad Ali , Junejo Aisha Zahid , Zawish Muhammad , Ahmed Kainat , Khalil Aiman , Soursou Georgia
Published: January 2019

Blockchain technology has gained considerable attention, with an escalating interest in a plethora of numerous applications, ranging from data management, financial services, cyber security, IoT, and food science to healthcare industry and brain research. There has been a remarkable interest witnessed in utilizing applications of blockchain for the delivery of safe and secure healthcare data management. Also, blockchain is reforming the traditional healthcare practices to a more reliable means, in terms of effective diagnosis and treatment through safe and secure data sharing. In the future, blockchain could be a technology that may potentially help in personalized, authentic, and secure healthcare by merging the entire real-time clinical data of a patient’s health and presenting it in an up-to-date secure healthcare setup. In this paper, we review both the existing and latest developments in the field of healthcare by implementing blockchain as a model. We also discuss the applications of blockchain, along with the challenges faced and future perspectives.
Synthesis, Single Crystal X-ray Structure, DFT Computations, Hirshfeld Surface Analysis and Molecular Docking Simulations on ({[(1E)-1-(1,3-Benzodioxol-5-yl)-3-(1H-imidazol-1-yl)propylidene]amino}oxy)(furan-2-yl)methanone: A New Antifungal Agent
Authors: Al-Wabli Reem I. , Al-Ghamdi Alwah R. , Aswathy S. V. , Ghabbour Hazem A. , Al-Agamy Mohamed H. , Hubert Joe I. , Attia Mohamed I.
Published: January 2019

The development of drug-resistance and high morbidity rates due to life-threatening fungal infections account for a major global health problem. A new antifungal imidazole-based oximino ester 5 has been prepared and characterized with the aid of different spectroscopic tools. Single crystal X-ray analysis doubtlessly identified the (E)-configuration of the imine fragment of the title compound. Compound 5, C18H15N3O5, was crystallized in the monoclinic, P21/c, a = 10.4067 (5) Å, b = 6.8534 (3) Å, c = 23.2437 (12) Å, β = 94.627 (2)°, V = 1652.37 (14) Å3, Z = 4. Spectral and electronic features of compound 5 have been thoroughly explored with the aid of density function theory (DFT) simulations and the data were compared with the experimental results. In addition, Hirshfeld surface analysis and molecular docking simulations were executed on the target compound. Molecular docking results are fairly consistent with the experimental in vitro antifungal potential of the oximino ester 5.
Phase Behaviors of Ionic Liquids Heating from Different Crystal Polymorphs toward the Same Smectic-A Ionic Liquid Crystal by Molecular Dynamics Simulation
Authors: Cao Wudi , Wang Yanting
Published: January 2019

Five distinct crystal structures, based on experimental data or constructed manually, of ionic liquid [C14Mim][NO3] were heated in NPT molecular dynamics simulations under the same pressure such that they melted into the liquid crystal (LC) phase and then into the liquid phase. It was found that the more entropy-favored structure had a higher solid-LC transition temperature: Before the transition into the LC, all systems had to go through a metastable state with the side chains almost perpendicular to the polar layers. All those crystals finally melted into the same smectic-A LC structure irrelevant of the initial crystal structure.
Use of a Polyetheretherketone Clasp Retainer for Removable Partial Denture: A Case Report
Authors: Ichikawa Tetsuo , Kurahashi Kosuke , Liu Lipei , Matsuda Takashi , Ishida Yuichi
Published: January 2019

Clasp retainers made of metal alloys may be esthetically unappealing or cause allergic reactions. To investigate alternative materials, we used the nonfiller polyetheretherketone (PEEK) to fabricate the clasp retainer of a removable partial denture for the mandibular bilateral distal free-end abutment of an 84-year-old female. Two years later, few color and texture changes of PEEK were found macroscopically. The rest part and the clasp arm fitted well without any deformation. There were no particular occlusal or periodontal problems. Subjective satisfaction was expressed by both the practitioner and the patient.
Cost Minimization Energy Control Including Battery Aging for Multi-Source EV Charging Station
Authors: Abronzini Umberto , Attaianese Ciro , D’Arpino Matilde , Di Monaco Mauro , Tomasso Giuseppe
Published: January 2019

A Multi-Source Electric Vehicle Charging Station (MS-EVCS) is a local entity that combines the grid energy with Distributed Energy Resources (DERs) with the aim of reducing the grid impact due to electric vehicles (EVs) charging events. The integration of stationary and in-vehicle Energy Storage Systems (ESSs) in MS-EVCSs has gained increasing interest thanks to the possibility of storing energy at off-peak hours to be made available at peak-hours. However, the ESS technology and the vehicle-to-grid (V2G) concept show several issues due to cost, battery life cycle, reliability, and management. The design of the MS-EVCS energy management system is of primary importance to guarantee the optimal usage of the available resources and to enhance the system benefits. This study presents a novel energy management strategy for Real-Time (RT) control of MS-EVCS considering DERs, stationary ESS, and V2G. The proposed energy management control allows defining the MS-EVCS control policy solving several cascaded-problems with the aim of achieving the minimum operating cost when the battery degradation and the stochastic nature of the sources are considered. The key feature of the proposed methodology is the lower computational effort with respect to traditional optimal control methodologies while achieving the same optimal solution.
Channel Sounding for Multi-User Massive MIMO in Distributed Antenna System Environment
Authors: Yu Seoyoung , Lee Jeong Woo
Published: January 2019

We propose a generation scheme for a sounding reference signal (SRS) suitable for supporting a large number of users in massive multi-input multi-output (MIMO) system with a distributed antenna system (DAS) environment. The proposed SRS can alleviate the pilot contamination problem which occurs inherently in the multi-user system due to the limited number of orthogonal sequences. The proposed SRS sequence is generated by applying a well-chosen phase rotation to the conventional LTE/LTE-A SRS sequences without requiring an increased amount of resource usage. We also propose using the correlation-aided channel estimation algorithm as a supplemental scheme to obtain more reliable and refined channel estimation. It is shown that the proposed SRS sequence and the supplemental channel estimation scheme improve significantly the channel estimation performance in multi-user massive MIMO systems.
A Quasi-Average Estimation Aided Hierarchical Control Scheme for Power Electronics-Based Islanded Microgrids
Authors: Hashmi Khurram , Mansoor Khan Muhammad , Xu Jianming , Shahid Muhammad Umair , Habib Salman , Faiz Muhammad Talib , Tang Houjun
Published: January 2019

Self-governed micro power networks are a promising solution for meeting the energy needs of isolated communities not having access to regular transmission networks. The control of such isolated networks requires regulation and “fair” sharing of several power generation and storage resources as well as efficient peer-to-peer coordination between power converters operating in the network. The regulation of key parameters as voltage, frequency and power sharing is to be ensured for the system to operate optimally. This paper proposes a new, de-centralized, and hierarchical control approach for power inverters in isolated micro networks with multi-layered controls, each addressing the regulation of key system parameters. The proposed scheme uses distributed quasi-averaging estimators at each participating node to achieve resilience towards disturbances caused by delayed transmission of measurement and control signals in the data acquisition and information exchange layer. Detailed system models are developed using MATLAB and Sim-power systems to test the effectiveness of the proposed scheme under varying control and network scenarios. The results of these studies are presented as pole zero evolutions, stability margins and case study wise simulations. The studies carried out verify the validity of the proposed control strategy for micro-distribution networks.
Design and Optimization of Supercapacitor Hybrid Architecture for Power Supply-Connected Batteries Lifetime Enhancement
Authors: Kim Jaemin , Shin Donghwa , Baek Donkyu , Park Jaehyun
Published: January 2019

AC power adapters for battery-operated systems, such as smartphones and notebook computers, not only supply run-time power to operate the devices but also charge the built-in batteries. The capacity of the adapter is optimized for the average power demand rather than the maximum power demand to reduce the size and weight of the adapter. Such a reduced capacity adapter may cause the battery to age even when the device is operated with the power adapter while under higher power demand, which is different from the expectation of most users. A recent study proposed a supercapacitor assist architecture to reduce the battery aging when the battery is powered by the adapter. However, the previous work only shows the potential of the architecture. In this work, we propose a design methodology to find the optimal setup for the supercapacitor hybrid architecture considering supercapacitor array structure and power conversion efficiency. The results show that a supercapacitor having 17.5 mF capacity and 20 V withstand voltage is enough to supply the deficient energy of a reduced capacity power adapter.
A Robust Registration Method for Autonomous Driving Pose Estimation in Urban Dynamic Environment Using LiDAR
Authors: Wang Rendong , Xu Youchun , Sotelo Miguel Angel , Ma Yulin , Sarkodie-Gyan Thompson , Li Zhixiong , Li Weihua
Published: January 2019

The registration of point clouds in urban environments faces problems such as dynamic vehicles and pedestrians, changeable road environments, and GPS inaccuracies. The state-of-the-art methodologies have usually combined the dynamic object tracking and/or static feature extraction data into a point cloud towards the solution of these problems. However, there is the occurrence of minor initial position errors due to these methodologies. In this paper, the authors propose a fast and robust registration method that exhibits no need for the detection of any dynamic and/or static objects. This proposed methodology may be able to adapt to higher initial errors. The initial steps of this methodology involved the optimization of the object segmentation under the application of a series of constraints. Based on this algorithm, a novel multi-layer nested RANSAC algorithmic framework is proposed to iteratively update the registration results. The robustness and efficiency of this algorithm is demonstrated on several high dynamic scenes of both short and long time intervals with varying initial offsets. A LiDAR odometry experiment was performed on the KITTI data set and our extracted urban data-set with a high dynamic urban road, and the average of the horizontal position errors was compared to the distance traveled that resulted in 0.45% and 0.55% respectively.
A Tilt Sensor Node Embedding a Data-Fusion Algorithm for Vibration-Based SHM
Authors: Testoni Nicola , Zonzini Federica , Marzani Alessandro , Scarponi Valentina , De Marchi Luca
Published: January 2019

This work describes a miniaturized sensor network based on low-power, light-weight and small footprint microelectromechanical (MEMS) sensor nodes capable to simultaneously measure tri-axial accelerations and tri-axial angular velocities. A real-time data fusion algorithm based on complementary filters is applied to extract tilt angles. The resulting device is designed to show competitive performance over the whole frequency range of the inertial units. Besides the capability to provide accurate measurements both in static and dynamic conditions, an optimization process has been designed to efficiently make the fusion procedure running on-sensor. An experimental campaign conducted on a pinned-pinned steel beam equipped with a network comprising several sensor nodes was used to evaluate the reliability of the developed architecture. Performance metrics revealed a satisfactory agreement to the physical model, thus making the network suitable for real-time tilt monitoring scenarios.
Adaptive Thermal-Aware Routing Protocol for Wireless Body Area Network
Authors: Jamil Faisal , Iqbal Muhammad Azhar , Amin Rashid , Kim DoHyeun
Published: January 2019

The recent advancement in information technology and evolving of the (IoT) shifted the traditional medical approach to patient-oriented approach (e.g., Telemedicine/Telemonitoring). IoT permits several services including sensing, processing and communicating information with physical and bio-medical constraints. Wireless Body Area Network (WBAN) handles the issues pertaining to the medical purposes in the form of sensor nodes and connected network. The WBAN takes human physiological data as an input to subsequently monitor the patient conditions that are transferred to other IoT components for analysis. Such monitoring and analysis demand a cohesive routing approach to ensure the safe and in-time transfer of data. The temperature rise of bio-medical sensor nodes makes the entire routing operation very crucial because the temperature of implanted nodes rises and ultimately damages body tissues. This needs dispersion in data transmission among different nodes by opting various available routes while avoiding temperature rise. In this paper, we present Adaptive Thermal-Aware Routing algorithm for WBAN. The ATAR is designed to overcome the temperature rise issue of implanted bio-medical sensors nodes. The new protocol is based on Multi-Ring Routing approach to find an alternative route in the case of increasing temperature. The simulation results indicate that proposed protocol is more efficient in terms of temperature rise and throughput than existing approaches.
Enhanced Time-of-Use Electricity Price Rate Using Game Theory
Authors: Khalid Adia , Javaid Nadeem , Mateen Abdul , Ilahi Manzoor , Saba Tanzila , Rehman Amjad
Published: January 2019

The emergence of the Demand Response (DR) program optimizes the energy consumption pattern of customers and improves the efficacy of energy supply. The pricing infra-structure of the DR program is dynamic (time-based). It has rather complex features including marginal costs, demand and seasonal parameters. There is variation in DR price rate. Sometime prices go high (peak load) if the demand of electricity is more than the generation capacity. The main objective of DR is to encourage the consumer to shift the peak load and gets incentives in terms of cost reduction. However, prices remain the same for all the users even if they shift the peak load or not. In this work, Game Theory (GT)-based Time-of-Use (ToU) pricing model is presented to define the rates for on-peak and shoulder-peak hours. The price is defined for each user according to the utilize load. At first, the proposed model is examined using the ToU pricing scheme. Afterward, it is evaluated using existing day-ahead real-time pricing scheme. Moreover, shifting load from on-peak hours to off-peak hours may cause rebound peak in off-peak hours. To avert this issue, we analysis the impact of Salp Swam Algorithm (SSA) and Rainfall Algorithm (RFA) on user electricity bill and PAR after scheduling. The experimental results show the effectiveness of the proposed GT-based ToU pricing scheme. Furthermore, the RFA outperformed SSA.
Operational Reliability Assessment of an Interconnected Power System Based on an Online Updating External Network Equivalent Model with Boundary PMU
Authors: Zhang Dabo , Lian Shuai , Tao Weiqing , Liu Jinsong , Fang Chen
Published: January 2019

Information between interconnected power systems is difficult to share in real time, due to trade secrets and technical limitations. The regional power grid cannot timely detect the impact of changes in the operation mode of the external power grid on the regional reliability, due to faults, load fluctuations, power generation plan adjustments, and other reasons. How to evaluate the reliability of a regional power system under the conditions of information isolation is a difficult problem for the security of interconnected power systems. Aiming at this problem, an operational reliability evaluation method for an interconnected power system is proposed herein, which does not depend on external network information directly, but only uses boundary phasor measurement unit (PMU) measurement data and internal network information. A static equivalent model with sensitivity consistency was used to simplify the external network to ensure the accuracy of the reliability calculation of interconnected power systems. The boundary PMU measurement data were used to update the external network equivalent model online. The algorithm flow of the operation reliability assessment for the interconnected power grid is given. The results of an example based on the IEEE-RTS-96 test system show that the proposed method can track the equivalent parameters of the external network without depending on the actual topological information, and calculate the reliability index of the internal network accurately.
Proactive Content Delivery with Service-Tier Awareness and User Demand Prediction
Authors: Hu Jing , Lai Yaling , Peng Ao , Hong Xuemin , Shi Jianghong
Published: January 2019

Cost-effective delivery of massive data content is a pressing challenge facing modern mobile communication networks. In the literature, two primary approaches to tackle this challenge are service-tier differentiation and personalized proactive content caching. However, these two approaches have not been integrated and studied in a unified framework. This paper proposes an integrated proactive content delivery scheme that jointly exploits the availability of multiple service tiers and multi-user behavior prediction. Three optimal algorithms and one heuristic algorithm are introduced to solve the cost-minimization problems of multi-user proactive content delivery under different modelling assumptions. The performance of the proposed scheme is systematically investigated to reveal the impacts of proactive window size, service-tier price ratio, and traffic cost model on the system performance.
Hardware-Enhanced Protection for the Runtime Data Security in Embedded Systems
Authors: Wang Weike , Zhang Xiaobing , Hao Qiang , Zhang Zhun , Xu Bin , Dong Haifeng , Xia Tongsheng , Wang Xiang
Published: January 2019

At present, the embedded systems are facing various kinds of attacks, especially for the data stored in the external memories. This paper presents a hardware-enhanced protection method to protect the data integrity and confidentiality at runtime, preventing the data from spoofing attack, splicing attack, replay attack, and some malicious analysis. For the integrity protection, the signature is calculated by the hardware implemented Lhash engine before the data sending off the chip, and the signature of the data block is recalculated and compared with the decrypted one at the load time. For the confidentiality protection, an AES encryption engine is used to generate the key stream, the plain data and the cipher data can translate through a simple XOR operation. The hardware cryptographic engines are optimized to work simultaneously with the memory access operation, which reduces the hardware overhead and the performance overhead. We implement the proposed architecture within OR1200 processor on Xilinx Virtex 5 FPGA platform. The experiment results show that the proposed hardware-enhanced protection method can preserve the integrity and confidentiality of the runtime data in the embedded systems with low power consumption and a marginal area footprint. The performance overhead is less than 2.27% according to the selected benchmarks.
Comparing Accuracy of Three Methods Based on the GIS Environment for Determining Winching Areas
Authors: Picchio Rodolfo , Latterini Francesco , Mederski Piotr S. , Venanzi Rachele , Karaszewski Zbigniew , Bembenek Mariusz , Croce Michele
Published: January 2019

In forestry interventions such as thinning or selection cutting, appropriate road and skid trail networks are essential for efficient forest operations, but also for limiting damage to the residual stand and soil. Recently, multiple studies have shown the advantage of precision forestry and the use of a geographic information system (GIS) in forest road network planning, replacing time-consuming manual measurements and skid trail design directly in the forest. The objective of this research was to test the accuracy of three GIS-based methods, the correct distance method (CDM), real distance buffer method 12 (RDBM12) and real distance buffer method 10 (RDBM10), in estimating the area accessible for winching along skid trails. The study was carried out in two mountain areas, Fibbino and San Martino al Cimino (Italy). All the methods for determining the winching area were based on GIS and digital terrain model (DTM) maps. Additionally, control distances were measured manually in both areas and the results were compared with the distances measured using the GIS methods. The initial results showed that all the methods were useful for determining the winching area in mountain conditions. However, in conclusion, the CDM and RDBM10 methods were more accurate and can be recommended for further use and development.
Adaptive Damping Control Strategy of Wind Integrated Power System
Authors: Deng Jun , Suo Jun , Yang Jing , Peng Shutao , Chi Fangde , Wang Tong
Published: January 2019

Random variation of grid-connected wind power can cause stochastic variation of the power system operating point. This paper proposes a new scheme to design an adaptive damping controller by tracking the variation of system operating points and updating the controller’s functions to achieve a robust damping control effect. Firstly, the operating space is classified into different modes according to the classification of wind power outputs. Multiple power system stabilizers (PSSs) are then designed. Secondly, the method of optimal classification and regression decision tree (CART) is utilized for classifying subspaces of system operating point and it is proposed that the on-line measurements from wide area measurement system (WAMS) are used for tracking the dynamic behaviors of stochastic drifting point and thus guide the updating of appropriate PSSs be switched on adaptively. A 16-generator-68-bus power system integrated with wind power is presented as a test system to demonstrate that the adaptive control scheme by use of the CART can damp multi-mode oscillations effectively when the wind power output changes.
Environmental Assessment of Municipal Solid Waste by Two-Stage Plasma Gasification
Authors: Ramos Ana , Teixeira Carlos Afonso , Rouboa Abel
Published: January 2019

Plasma gasification is a thermal treatment successfully applied to waste streams, especially for solid residues. It sets an upgrade to more common waste-to-energy (WtE) techniques as incineration or gasification, granting lower levels of pollutant emissions, less landfilled materials and higher conversion efficiencies and producer gas quality. A life cycle assessment (LCA) of plasma gasification for one ton of a defined stream of solid waste is presented and compared to the hypothetical outcomes of incineration, highlighting the need to implement such sustainable techniques rather than more polluting ones. CML 2001 methodology was applied, enabling the evaluation of eleven impact categories, all of them depicting avoided burdens for the environment. Enhanced efficiency and cleanliness were seen due to the plasma step and to the replacement of part of the electrical grid mix by the produced electricity. Plasma gasification presented an overall better performance than incineration, portraying savings in energy and material resources as well as lower emissions to freshwater. Additionally, lower amounts of air contaminants were seen as well as almost triple of the produced electricity.
Performance Prediction Based on Effects of Wrapping Angle of a Side Channel Pump
Authors: Pei Ji , Zhang Fan , Appiah Desmond , Hu Bo , Yuan Shouqi , Chen Ke , Asomani Stephen Ntiri
Published: January 2019

This paper seeks to predict the performance of the side channel pump by considering the influences of different wrapping angles. Firstly, three pump cases 1, 2 and 3 are modeled with wrapping angles 15°, 30° and 45°, respectively. Secondly, different physical parameters comprising exchanged mass flow, pressure and velocity distributions are plotted at the best efficiency point (QBEP) to analyze the internal flow characteristics. Since the flow exchange times depend on the size of the wrapping angle, the size of the wrapping angle has significant effects on the pump head performance. Case 1 with the smallest wrapping angle recorded the largest head improvement at all operating conditions compared to case 2 and case 3. Case 1 at QBEP attained a head coefficient increase of about 9.8% and 38.6% compared to that of case 2 and case 3, respectively. However, the size of the wrapping angle had a slight effect on the pump efficiency; thus, case 1 still predicted a marginal increase in efficiency compared to case 2 and case 3 at all operating conditions. Lastly, the numerical simulations were validated with experimental data after manufacturing pump case 2.
Utilization of Carbon Dioxide in Coal Gasification—An Experimental Study
Authors: Zdeb Janusz , Howaniec Natalia , Smoliński Adam
Published: January 2019

Utilization of coal in the current energy sector requires implementation of highly-efficient technologies to meet the dual targets of increased energy-efficiency and reduced carbon footprint. Efforts are being made to develop gasification systems with lower unit emissions of carbon dioxide and other contaminants, capable of handling various feedstocks and flexible in terms of products generated (synthesis gas, hydrogen, heat and electricity). The utilization of captured carbon dioxide and waste heat in industrial processes are considered to further contribute to the advancements in energy-efficient and low-emission technological solutions. This paper presents the experimental results on the incorporation of carbon dioxide into the valorization cycle as a reactant in coal gasification. Tests were performed on a laboratory scale moving bed gasifier using three system configurations with various simulated waste heat utilization scenarios. The temperature range covered 700, 800 and 900 °C and the gasification agents used were carbon dioxide, oxygen and the mixture of 30 vol.% carbon dioxide in oxygen. The combined effect of the process parameters applied on the efficiency of coal processing in terms of the gas yields, composition and calorific value was studied and the experimental data were explored using Principal Component Analysis.
Simulation Research on the Effect of Coupled Heat and Moisture Transfer on the Energy Consumption and Indoor Environment of Public Buildings
Authors: Yu Shui , Cui Yumeng , Shao Yifei , Han Fuhong
Published: January 2019

A building envelope is a multi-layer porous structure. It transfers heat and moisture to balance the indoor and outdoor temperature difference and water vapor partial pressure difference. This is a typical coupled heat and moisture migration process. When the space is filled with moist air, water or ice, it will directly affect the thermal properties of the material. With respect to moisture coming through the wall into the indoor building, it will also affect the indoor environment and the energy consumption due to the formation of latent heat. However, the moisture transfer process in the building envelopes is not taken into account in the current conventional thermal calculation and energy consumption analysis. This paper analyzes the indoor thermal and humidity environment and building energy consumption of typical cities in Harbin, Shenyang, Beijing, Shanghai, and Guangzhou. The results show that it is obvious that the coupled heat and moisture transfer in the building envelopes has an impact on the annual cooling and heating energy consumption, the total energy consumption, and the indoor thermal and humidity environment. The geographical location of buildings ranging from north to south influences the effect of coupled heat and moisture transfer on the annual energy consumption of the building, moving from positive to negative. It is suggested that the additional coefficient of the coupled thermal and moisture method can effectively correct the existing energy consumption calculation results, which do not take the consumption from the coupled heat and moisture in the building envelopes into account.
Control Effects of Five Common Solid Waste Backfilling Materials on In Situ Strata of Gob
Authors: Huang Peng , Spearing Sam , Ju Feng , Jessu Kashi , Wang Zhongwei , Ning Pai
Published: January 2019

Solid backfill mining as a green mining method has already been successfully applied in many mine sites. Higher requirements for the backfilling materials have been put forward in special regions, such as shallow coal seams, ecologically susceptible areas, and sites with building on the surface. The control effects of common backfilling materials on in situ strata of gob need to be studied and compared to ensure the suitable materials are applied in the mine. The meso-structure, stress variation, energy dissipation, and backfilling effects of the five common solid backfilling materials, which are Aeolian sand, gangue, mineral waste residue, coal ash, and loess are analyzed in this paper. The results show that the Aeolian sand and gangue are densely packed and internally hard when compared to other backfill materials. The deformation of the five materials to absorb the same amount of energy in the order of higher to lower was determined as Aeolian sand, gangue, mineral waste residue, coal ash and loess. The Aeolian sand’s strain energy density is 1.67 times larger than the loess, however, the Aeolian’s strain energy density in front of working face is just 32.2% of the loess, which is important to ensure the safety of the working face. The stress changes were monitored in situ with Aeolian sand and gangue as backfill materials. The monitoring results show that the Aeolian sand stress increase rate is quicker than gangue, which can support the roof effectively.
User-Centric Consumption Scheduling and Fair Billing Mechanism in Demand-Side Management
Authors: Charoen Prasertsak , Sioutis Marios , Javaid Saher , Charoenlarpnopparut Chalie , Lim Yuto , Tan Yasuo
Published: January 2019

In the smart grid, residential consumption scheduling in demand-side management (DSM) is one of the key technologies to facilitate utility companies and users in order to achieve systems optimality such as minimizing energy cost and demand peak. The success of DSM implementation depends on the level of user participation. While most of the prior works on DSM have reported good optimal results, they show a lack of focus towards user-centric issues such as user preferences, consumption deviation, and system fairness. Failure to account for such issues may lead to lower user participation in DSM programs. To address this problem, we propose user-centric consumption scheduling and fair billing mechanism for DSM program which consider economic as well as comfort aspects. First, a user’s discomfort cost is integrated into price incentives for determining consumption schedules. Second, consumption rescheduling mechanism is designed to allow users to change their preferences if necessary, and request new schedules. Finally, to improve the level of system fairness and avoid strategic players who try to manipulate the consumption profile for their benefit, a fair billing mechanism is proposed at the end of the scheduling period which takes into account both rescheduling users and user’s consumption deviation level. Simulation results show the effectiveness of the proposed method in terms of energy cost saving and improving fairness in the user’s billing.
Alternative Design of Double-Suction Centrifugal Pump to Reduce the Effects of Silt Erosion
Authors: Dong Jing , Qian Zhongdong , Thapa Biraj Singh , Thapa Bhola , Guo Zhiwei
Published: January 2019

Large amounts of sediment in the Himalayan rivers causes severe silt erosion to the hydraulic machinery operating along these rivers. In this study, the effects of silt characteristics on the silt-erosion characteristics of a double-suction centrifugal pump was studied and the anti-erosion property of bionic convex domes on silt erosion under these conditions was explored by using computational-fluid-dynamics methods, partly supported by a painted-blade erosion experiment. The results show that the silt size affects the erosion position and erosion strength, whereas the silt concentration mainly affects the erosion strength for the studied range. The bionic convex domes provide an effective solution to improve the silt erosion for most of the investigated silt-laden conditions by decreasing the erosion rate and the erosion area of the blade. The anti-erosion mechanism was studied combined with large eddy simulation. The analysis shows that the relative velocity of water around the blade surface is changed and the mass flow rate of silt particles hitting the blade is reduced by inducing swirling flows around the bionic convex domes.
An Agent Based Model to Analyze the Bitcoin Mining Activity and a Comparison with the Gold Mining Industry
Authors: Cocco Luisanna , Tonelli Roberto , Marchesi Michele
Published: January 2019

In this paper, we present an analysis of the mining process of two popular assets, Bitcoin and gold. The analysis highlights that Bitcoin, more specifically its underlying technology, is a “safe haven” that allows facing the modern environmental challenges better than gold. Our analysis emphasizes that crypto-currencies systems have a social and economic impact much smaller than that of the traditional financial systems. We present an analysis of the several stages needed to produce an ounce of gold and an artificial agent-based market model simulating the Bitcoin mining process and allowing the quantification of Bitcoin mining costs. In this market model, miners validate the Bitcoin transactions using the proof of work as the consensus mechanism, get a reward in Bitcoins, sell a fraction of them to cover their expenses, and stay competitive in the market by buying and divesting hardware units and adjusting their expenses by turning off/on their machines according to the signals provided by a technical analysis indicator, the so-called relative strength index.
Solvent-Free Reactive Vapor Deposition for Functional Fabrics: Separating Oil–Water Mixtures with Fabrics
Authors: Cheng Nongyi , Park Kwang-Won , Andrew Trisha L.
Published: January 2019

A facile, solvent-minimized approach to functionalize commercial raw fabrics is described. Reactive vapor deposition of conjugated polymers followed by post-deposition functionalization transforms common, off-the-shelf textiles into distinctly hydrophobic or superhydrophilic materials. The fabric coatings created by reactive vapor deposition are especially resistant to mechanical and solvent washing, as compared to coatings applied by conventional, solution-phase silane chemistries. Janus fabrics with dissimilar wettability on each face are also easily created using a simple, three-step vapor coating process, which cannot be replicated using conventional solution phase functionalization strategies. Hydrophobic fabrics created using reactive vapor deposition and post-deposition functionalization are effective, reusable, large-volume oil–water separators, either under gravity filtration or as immersible absorbants.
The Evolution of Cooperation in One-Dimensional Mobile Populations with Deterministic Dispersal
Authors: Erovenko Igor V.
Published: January 2019

I investigate how different dispersal patterns affect the evolution of cooperation in a spatially-structured population. I consider a finite fixed-size population of cooperators and free-riders residing on a one-dimensional lattice with periodic boundaries. Individuals interact via a multiplayer game, which is a version of a public goods game, and the population evolves via a Moran process. Individuals try to improve their interactions by evaluating the current state of the environment and moving to locations with better payoffs. I ran stochastic simulations of the evolution of this Markov process and found that if individuals disperse deterministically to locations with the best payoffs, then cooperation can still be maintained even in the worst-case scenarios, albeit at reduced levels compared to the better-case scenarios. This contrasts with an earlier investigation of probabilistic dispersal patterns, which resulted in the breakdown of cooperation in sparse populations with small interaction neighborhoods, a high mobility rate, and a large dispersal range.
Immigration, Identity, and Genealogy: A Case Study
Authors: Knight Thomas Daniel
Published: January 2019

This paper examines the life and experiences of a 19th-century immigrant from the British Isles to the United States and his family. It examines his reasons for immigrating, as well as his experiences after arrival. In this case, the immigrant chose to create a new identity for himself after immigration. Doing so both severed his ties with his birth family and left his American progeny without a clear sense of identity and heritage. The essay uses a variety of sources, including oral history and folklore, to investigate the immigrant’s origins and examine how this uncertainty shaped the family’s history in the 19th and 20th centuries. New methodologies centering on DNA analysis have recently offered insights into the family’s past. The essay ends by positing a birth identity for the family’s immigrant ancestor. Importantly, the family’s post-immigration experiences reveal that the immigrant and his descendants made a deliberate effort to retain aspects of their pre-immigration past across both time and distance. These actions underscore a growing body of literature on the limits of post-immigration assimilation by immigrants and their families, and indicate the value of genealogical study for analyzing the immigrant experience.
The Beat Generation Meets the Hungry Generation: U.S.—Calcutta Networks and the 1960s “Revolt of the Personal”
Authors: Belletto Steven
Published: January 2019

This essay explores the relationship between the U.S.-based Beat literary movement and the Hungry Generation literary movement centered in and around Calcutta, India, in the early 1960s. It discusses a trip Allen Ginsberg and Peter Orlovsky took to India in 1962, where they met writers associated with the Hungry Generation. It further explains how Lawrence Ferlinghetti, owner of City Lights Books in San Francisco, was inspired to start a new literary magazine, City Lights Journal, by Ginsberg’s letters from India, which included work by Hungry Generation writers. The essay shows how City Lights Journal packaged the Hungry Generation writers as the Indian wing of the Beat movement, and focuses in particular on the work of Malay Roy Choudhury, the founder of the Hungry Generation who had been prosecuted for obscenity for his poem “Stark Electric Jesus”. The essay emphasizes in particular the close relationship between aesthetics and politics in Hungry Generation writing, and suggests that Ginsberg’s own mid-1960s turn to political activism via the imagination is reminiscent of strategies employed by Hungry Generation writers.
Is Left Ventricular Global Longitudinal Strain by Two-Dimensional Speckle Tracking Echocardiography in Sepsis Cardiomyopathy Ready for Prime Time Use in the ICU?
Authors: Velagapudi Venu Madhav , Pidikiti Rahul , Tighe Dennis A.
Published: January 2019

Myocardial deformation imaging (strain imaging) is a technique to directly quantify the extent of myocardial contractility and overcomes several of the limitations of ejection fraction. The application of the most commonly used strain imaging method; speckle-tracking echocardiography to patients with sepsis cardiomyopathy heralds an exciting development to the field. However; the body of evidence and knowledge on the utility, feasibility and prognostic value of left ventricular global longitudinal strain in sepsis cardiomyopathy is still evolving. We conducted a review of literature on utility of left ventricular global longitudinal strain in sepsis cardiomyopathy. We discuss the role of left ventricular global longitudinal strain in mortality prediction, utility and limitations of the technique in the context of sepsis cardiomyopathy.
Development of a Potentially Hazardous Pro-Glacial Lake in Aksay Valley, Kyrgyz Range, Northern Tien Shan
Authors: Zaginaev Vitalii , Falatkova Kristyna , Jansky Bohumir , Sobr Miroslav , Erokhin Sergey
Published: January 2019

Debris flows caused by glacial lake outburst floods (GLOFs) are common hazards in mountain environments. The risk posed by glacial lake outburst hazards is particularly evaluated where the lower reaches of catchments are populated. A potentially dangerous lake has been identified adjacent to the Uchitel Glacier in Northern Tien Shan. This lake formed between 1988 and 1994 on the site of a retreated glacier in the upper part of the Aksay Valley. In this study we consider the possibility of an outburst of this pro-glacial lake in the future. The study involved bathymetry mapping of the lake, detailed profile sections of the valley, flow rate measurements on the Aksay river, and monitoring of the lake development using satellite images. Modelling of secondary debris flow inundation heights and hazard footprints has been undertaken. The outburst of this lake could cause powerful debris flows posing a threat to permanent residents living downstream, in the Ala-Archa Valley. Monitoring of the lake over the past ten years suggests certain changes in the runoff to the subsurface, and an increase in lake depth is observed. Glacial lakes with subsurface drainage are considered to be the most hazardous type as the knowledge of drainage channels functioning is still very limited and, thus, the timing of an outburst is hard to predict. Development of monitoring approaches to support forecasting of these hazards is of paramount importance to safety in mountain territories globally.