bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of the relationship between DC component and spectral components of corona current on HVDC transmission lines
Authors: Liu Yingyi , Liu Yuanqing , Cui Yong , Yuan Haiwen , Lv Jianxun
Published: March 2019

Corona current is an important parameter to characterise the corona discharge on high‐voltage direct current (HVDC) transmission lines. The spectral components of corona current are closely related to a variety of corona effects, such as audible noise. It is of great significance to study the frequency‐domain characteristics of corona current. Here, the relationship between DC component and spectral components of corona current on HVDC transmission lines in the band of 2–20 kHz was analysed. First, a lot of corona current data were measured in two HVDC experiment bases. Then, the expression representing the correlation between DC component and spectral components of corona current within 2–20 kHz was established with the maximum surface nominal electric field intensity of conductor as an intermediate variable. Finally, the correctness and universality of the relationship found were verified. The research results here not only reveal the characteristics of corona discharge but can also provide a new way for obtaining the spectral components of corona current in 2–20 kHz with its DC component, and can lay the foundation to provide a new way to get audible noise indirectly based on the DC component of corona current in the future.
Impact of FFC distributed generations in a DNR in the presence of renewable and load uncertainties by mixed‐discrete particle swarm‐based point estimation method
Authors: Barik Soumyabrata , Das Debapriya
Published: March 2019

This study presents the uncertainty analysis of a distribution network (DNR) caused by unit power output control (UPC) distributed generations (DGs) (solar, wind) and load demand by point estimate method (PEM) based on mixed‐discrete‐based particle swarm optimisation (MDPSO) technique. The uncertainties are taken care by the feeder flow control (FFC) DGs which make the DNR power independent of the main grid, which means the DNR does not exchange any power with the main grid at any load level. To analyse the situation, the load flow technique is modified with introducing and zero bus in the system. and the higher‐order PEM methods are applied in this study for uncertainty analysis. The FFC and the UPC DGs are placed and sized by the MDPSO algorithm. The uncertainty analysis of the system is done based on different objective functions and test cases which are the combinations of active power loss, voltage deviation, and the DG operation cost. The proposed method is applied to the 69‐bus DNR, and the results are compared with teaching learning‐based meta‐heuristic optimisation method. The cumulative distribution function and probability density function of the output random variable are approximate with Gram–Charlier expansion method.
Optimal sizing of a wind/solar/battery/diesel hybrid microgrid based on typical scenarios considering meteorological variability
Authors: Yang Dongfeng , Jiang Chao , Cai Guowei , Huang Nantian
Published: March 2019

Microgrid systems, such as solar photovoltaic (PV) and wind turbine (WT), integrated with diesel generator can provide adequate energy to supply increased demands and are economically feasible for current and future use considering depletion of conventional sources. It is, thus, important to determine the appropriate sizes of PV, WT, diesel generator, and associated energy storage system (ESS) for efficient, economic, and reliable operation of electric power system in microgrid. Stochastic nature of intermittent renewable energy (RE) resources complicate their planning, integration, and operation of electric power system. Therefore, it is critical to generate typical scenarios of wind speed, irradiation, and load time series to reflect their stochastic characteristic for microgrid system planning and operation. In this study, a wind‐irradiation‐load typical scenarios generation method is proposed for optimal sizing RE resources of microgrid. The teaching‐learning‐based optimisation (TLBO) method is used to find the best configuration of the microgrid system. Simulation results show that scenarios generated by the proposed model have ability to approximate the original scenarios and reduce planning data effectively.
Unravelling the effects of berry size on ‘Tempranillo’ grapes under different field practices
Authors: Mirás-Avalos José M. , Buesa Ignacio , Yeves Antonio , Pérez Diego , Risco David , Castel Juan R. , Intrigliolo Diego S.
Published: March 2019

Small berries are considered to produce the best red wines as berry size determines the skin to pulp ratio and may affect wine composition. However, contrasting results have been reported about this postulate. In this context, the aim of this work was to assess the influence of berry size on grape compositional attributes in ‘Tempranillo’ grapevines under different irrigation, crop load and defoliation regimes. Grapes were collected from different experiments performed during three years in a ‘Tempranillo’ vineyard (Valencia, Spain). Grape size distribution was assessed and several traits were measured for each size category: number of seeds, seed and skin weight, total soluble solids, titratable acidity, pH, total phenolic index and anthocyanin concentration. Berry size exerted a significant effect on grape composition; smaller berries having higher sugars and anthocyanins concentrations. However, irrigation, crop load and defoliation also affected these compositional traits, producing greater berries with similar traits than those smaller, but coming from rain-fed and not defoliated treatments. Depending on the field practices applied, grape compositional attributes can be modulated for a given berry size. Therefore, wineries can use berry size classification for selecting those from a given size for making different wine styles.
XYZ states as hadronic molecules
Authors: Nefediev A.V.
Published: March 2019

In the past decade, a lot of new hadrons containing heavy quarks were discovered which do not fit into the scheme provided by the traditional quark models. Such states are known as the XYZ states and they are conventionally referred to as exotic ones. At present, there is no consensus on their nature, and different models and approaches have been suggested to explain their unusual properties. The talk is devoted to a brief overview of the molecule model for such exotic states.
Double heavy tri-hadron bound state with strange flavor
Authors: Ma Li
Published: March 2019

Through the Born-Oppenheimer Approximation, we have performed a comprehensive investigation of the DD∗K, D$ \overline D $*K, BB∗$ \overline K $ and B$ \overline B $*$ \overline K $ molecular states. In the framework of One-Pion Exchange model as well as the treatments of the coupled-channel eﬀects and S-D wave mixing, we find a loosely bound tri-meson molecular state these systems with the isospin configuration |0,$ {1 \over 2} $, ±$ {1 \over 2} $> and quantum number I(JP) = 1/2(1−), where the, $ {1 \over 2} $ is the total isospin of the three-body system, the 0 is the isospin of the D∗K, $ \overline D $*K, B∗$ \overline K $ and $ \overline B $∗$ \overline K $. With the estimated error, the mass of the DD∗K or D$ \overline D $∗K molecule is $ 4317.92_{ - 4.32}^{ + 3.66} $ MeV or $ 4317.92_{ - 6.55}^{ + 6.13} $MeV. We also extend our calculations to the bottom sector and find tri-meson bound states for the BB∗$ \overline K $ and B$ \overline B $*$ \overline K $ with the mass $ 11013.65_{ - 8.84}^{ + 8.49} $ MeV and $ 11013.65_{ - 9.02}^{ + 8.68} $MeV respectively.
Angular analysis of the e+e- → D(*)D* process near the open-charm threshold using initial-state radiation
Authors: Zhukova Valentina
Published: March 2019

We report new measurement of the exclusive e+e- → D(*)±D*∓ cross sections as a function of center-of-mass energy from the D(∗)±D∗∓ threshold up to $ \sqrt s $ = 6.0 GeV with initial state radiation. The analysis is based on a data sample collected by the Belle detector with an integrated luminosity of 951 fb−1. The accuracy of the cross section measurement is increased by a factor of 2 in comparison with the first Belle study. We have performed the first angular analysis of the e+e- → D∗±D∗∓ process and decomposed this exclusive cross section into three components corresponding to the different D∗ helicities.
Properties of Zb(10610) and Zb(10650) from an analysis of experimental line shapes
Authors: Baru V. , Filin A. A. , Hanhart C. , Nefediev A. V. , Wang Q. , Wynen J.-L.
Published: March 2019

The experimental line shapes available in the B$ \bar {B} $*, B*$ \bar {B} $*, hb(1P)π and hb(2P)π channels are analysed using a theoretical EFT-based framework manifestly consistent with unitarity and analyticity. The line shapes are calculated using a system of coupled channel integral equations with the potential consisting of the one-pion and one-eta meson exchange interactions from the lightest Goldstone boson octet as well as of several contact terms at leading and subleading orders which are adjusted to minimise the overall chi squared. The pole positions of the Zb(10610) and Zb(10650) are extracted for the best fits corresponding to χ2/d.o.f. of the order of one.
Simulation of vertical tidal turbine based on OpenFOAM and influence of inlet turbulence
Authors: Yun-ya Liu , Yang Yu-chen , Yang Ya-wen
Published: March 2019

This paper first introduces the basic theory of CFD method, including basic control equations, finite volume method, control equation solving algorithm and turbulence model selection. Second, based on OpenFOAM, an open-source fluid mechanics software, a numerical simulation method of vertical axis tidal turbine was proposed by using k-ω SST turbulence model and PIMPLE algorithm. The hydrodynamic characteristics of the vertical axis turbine were studied, and the calculation results were compared with experiments. The higher consistency proves the feasibility of the numerical simulation method proposed in this paper. Finally, the influence of inlet turbulence on numerical simulation was explored, and a set of effective CFD simulation strategies was concluded, which provided a valuable reference for future CFD simulation and research on vertical axis tidal turbines.
Research on ordered charge and discharge of cluster electric vehicle based on index selection
Authors: Hu Chunxuan , Li Tianran , Yuan Chao
Published: March 2019

The basic characteristics of electric vehicles are important basis for studying the behavior of electric vehicles. According to the basic characteristics of electric vehicles, this paper establishes an electric vehicle convergence model and its control strategy with demand-side response. Taking into account the demand for electric vehicles, electric vehicle aggregators and power companies, reducing the cost of control, while reducing the impact on electric vehicles. Based on the real-time state of charge, the conditions of electric vehicle in the network and other factors to build the assessment model of the scheduling potential, and then put forward the demand response indicators of electric vehicles, and give the corresponding aggregation strategy. considering the multiple constraints , such as the cost constraints of electric vehicles participating in grid regulation, the charging requirements of electric vehicle owners, and the battery consumption of electric vehicles, a control strategy model is proposed for electric vehicles participating in demand response of power systems. The simulation test shows that the aggregation strategy can not only meet the travel needs of electric vehicle owners, but also reduce the impact on the electric vehicle caused by frequent switching of charge and discharge status. In addition, it can also reduce the cost of grid regulation.
A modified multilevel k-way partitioning algorithm for trip-based road networks
Authors: Withanage C , Lakmal D , Hansini M , Kankanamge K , Witharanage Y , Thayasivam U
Published: March 2019

In today’s world, the traffic volume on urban road networks is multiplying rapidly due to the heavy usage of vehicles and mobility on demand services. Migration of people towards urban areas result in increasing size and complexity of urban road networks. When handling such complex traffic systems, partitioning the road network into multiple sub-regions and managing the identified sub regions is a popular approach.
In this paper, we propose an algorithm to identify sub-regions of a road network that exhibit homogeneous traffic flow patterns. In a stage wise manner, we model the road network graph by using taxi-trip data obtained on the selected region. Then, we apply the proposed modified multilevel kway partitioning algorithm to obtain optimal number of partitions from the developed road graph. An interesting feature of this algorithm is, resulting partitions are geographically connected and consists minimal interpartition trip flow. Our results show that the proposed algorithm outperforms state-of-the-art multilevel partitioning algorithms for tripbased road networks. By this research, we demonstrate the ability of road network partitioning using trip data while preserving the partition homogeneity and connectivity.
Greedy approach for solving the capacitated vehicle routing problem of liquefied natural gas distribution to power plants
Authors: Wijharnasir A P A , Alghasi M A , Pujawan N
Published: March 2019

In LNG industries, how to decide the number of ships and their routes for transporting LNG to every demand location efficiently effects the minimization of total operational cost. Therefore, this paper provides a case study in Papua and proposes a model to determine the optimum ship route to transport LNG from an LNG production terminal to thirteen regasification terminals by considering both transportation cost and inventory cost. Distance, power plants demands, transportation cost, and inventory cost were further analyzed by using the greedy approach. In addition, the ship sizes were limited to four alternatives, which were 2500 m3, 7500 m3, 10000 m3, and 23000 m3. The result recommends the utilization of smaller size vessels with more frequent shipments compared to the earlier research on the same case study. It considers that the result will be more adaptable for changing water depth due to changing tides at particular ports.
Numerical analysis of the embedded track structure under mixed traffic load
Authors: Bu Jianqing , Li Junpeng
Published: March 2019

Taking into account that the embedded track structure not only bears the load from tram, but also suffers from road traffic, this paper aims to establish the finite element analysis model of embedded track structure in the mixed traffic area with ABAQUS software, calculates the deformation and stress of asphalt surface course and filling material. Also,
the paper puts forward the way to improve the structural stability of embedded track.
Lane-based optimization for signalized network configuration designs
Authors: Wong C K , Liu Yi
Published: March 2019

Lane-based traffic signal design has been developed for designing signal-controlled intersections. Conventional designs take on fixed configurations as exogenous inputs to design traffic signal settings.
The proposed study will be an extension to merge geometrical junction arrangement and signal controls together for network configuration designs.
Design methodology would be directly extended from existing lane-based design method. New Path flows variables and new flow conservation constraints are required to ensure the users’ input OD flows could be assigned onto network paths through different signal-controlled intersections. This problem is new that involves binary variables and related linear constraints which is formulated as a BMILP. Standard technique could solve the optimum solution. A four-intersection network with two approach lane settings is optimized for demonstration purposes.
Long-term behavior of connections for glubam-concrete composite beams
Authors: Ye Xin , Shan Bo , Yue Qian , Wang Zhenyu
Published: March 2019

Glubam-concrete composite (BCC) structure is a construction technique where glue-laminated bamboo beam is connected to an upper concrete slab using different types of connectors. The long-term behavior and creep mechanism of BCC system are very complex due to different time-dependent behavior of three components. This paper performed a series long-term push-out tests on four types of connections under static load. The tests lasted for a period of seven months in uncontrolled sheltered indoor condition. Important results such as the relative slip-time curves are presented in order to characterize time-dependent behavior of connectors. Furthermore creep coefficient constitutive models are provided for predicting the long-term behavior of connections.
Behaviour of Parallel Bamboo Strand Lumber under compression loading – an experimental study
Authors: Li Xin , Ashraf Mahmud , Li Haitao , Zheng Xiaoyan , Ameri Ali A.H. , Al-Deen Safat
Published: March 2019

This paper investigates the compression behaviour of 18 Parallel Bamboo Strand Lumber specimens. 25 mm × 25 mm square specimens with varying heights and fibre orientations were tested. Test results indicated typical 5-stage failure path, and a 45º failure plane in all specimens when the compression load was applied parallel to the fibres. Specimen height did not affect the ultimate load carrying capacities but showed considerable influence on the initial stiffness as well as the post-ultimate loading regime. Experimental results showed that the deformation ratio and the energy absorption ratio for longer specimens were not affected by fibre orientations.
Effects of APP/SiO2polyelectrolyte composites on wood-plastic composite
Authors: Chen He , Zhang Shuai , Cai Xin , Pan Mingzhu
Published: March 2019

This paper was aimed to evaluate process of APP/SiO2, which used Nano-crystalline cellulose (NCC) modified ammonium polyphosphate (APP) as anionic polyelectrolyte (a-APP), and cationic polyethyleneimine (PEI) modified Nano–SiO2as cationic polyelectrolyte (c-SiO2). The flame retardant system was built due to the reaction of a-APP and c-SiO2. Polyelectrolyte composite of a-APP/c-SiO2were then assembled on the surface of wood powder and HDPE composites. The effect of polyelectrolytes on wood-plastic composites (WPC) were investigated and the results showed that the flame-retardant property of WPC treated by polyelectrolyte was the best. The average heat release rate was 152.8kW/m2, the peak heat release rate was 352.2kW/m2, the total heat release was 108.5kW/m2, the limit oxygen index reached the maximum was 27.5%, compared with the WPC treated by APP, the elongation at break increased by 60.4%. After anionic and cationic polyelectrolyte treatment, making anionized a-APP and cationized c-SiO2due to the charge interaction, in the WPC combustion process to form a dense, uniform WPC carbon layer, thereby reducing the heat transfer to the material inside, and increasing the flame retardancy of WPC composites.
Research of the size effect on shear strength of metal-plate connector joints in China
Authors: Wang Chuang , Zhang Xinpei , Zhao Peiyan , Que Zeli
Published: March 2019

According to the reliability theory, the size effect has a great impact on the design value on shear strength of metal-plate connector. But little research has been done. So, based on GB/T50329-2002 of China, firstly, determining the size of metal-plate at different conditions, size effect tests were then conducted on metal-plate connectors composed of a type of Chinese metal-plate and 2# SPF dimension lumber from North America. A total of 125 metal-plate connectors are tested at five angles (90°, 60°T, 120°C, 150°C, 30°T), with Five kinds of widths (50mm，85mm，125mm，150mm，180mm) for each angle. Based on the testing data, fitting curve of size effect is presented, and width-effect parameters are estimated with SPSS(Statistic Package for Social Science). Results indicate that the width effect is significant; shear strength increases with the increase of width, and stays stable after a certain width.
Digital analysis of the geometric variability of bamboo poles in bending
Authors: Lorenzo Rodolfo , Mimendi Leonel , Li Haitao
Published: March 2019

The importance of sustainable materials in the building industry has grown during the last decades due to the negative impact that industrialised materials have caused over the environment as a consequence of the rapid increase of urban areas, especially in developing countries. To alleviate this problem, research has focused on the utilisation of bamboo, a ready-to-use natural material with a high potential of playing an important role in the future development of the building industry, however, the limitations of the material have not been properly addressed and therefore, the current use of bamboo in the building industry is negligible. This paper presents a digital approach to analyse the structural effects that the inherent geometric variability causes in bamboo poles subjected to bending effects. In contrast with current methodologies that apply the use of conventional tools to determine average geometric properties of a bamboo pole, this work adopted a combination of material testing and 3D scanning of a series of bamboo elements, in order to define suitable parameters for structural analysis that accurately represents the geometric variability of the poles. The results confirmed that the geometric variability produces significant effects that had not been considered before in the mechanical characterisation of bamboo, and that could not have been possible to identify without the use of digital technology. This work encourages the future development of methodologies that implement the use of digital technology to increase the structural understanding of bamboo and therefore, offer a robust platform for the general implementation of bamboo culms in the building industry.
Failure Modes and Mechanical Properties of Bracket Anchor Connections for Cross-Laminated-Timber
Authors: Shen Yinlan , Schneider Johannes , Stiemer Siegfried F. , Ren Xueyong
Published: March 2019

The paper presents some experimental data and phenomenon on bracket anchor connections for Cross-Laminated-Timber. The goal of this research is to provide a better understanding of the seismic performance of bracket connections subjected to seismic actions and how to choose and design bracket connections for Cross-Laminated-Timber structures. Test configuration and experimental setups are illustrated in details; cyclic displacement schedules of the connections in two directions are presented considering that CLT wall has horizontal sliding in the plane and uplift at the end in quasi-state tests. Different failure modes and force transmission mechanisms of different connections under the loading protocol were analysed. And important quantities for seismic design such as strength, and stiffness, equivalent yield load, peak load and ductility of the connections are evaluated and compared among different kinds of connections; an excellent connector is revealed in ductility and load capacity by test data analysis. In addition, some suggestions to choose and design bracket anchor connections are given.
Calculation of Sound Insulation for Hybrid CLT Fabricated with Lumber and LVL and comparison with experimental data.
Authors: Ju Zehui , He Qian , Zhang Haiyang , Zhan Tianyi , Hong Lu , Lin Yangfan , Lu Xiaoning
Published: March 2019

The insulated predictions were carried out for LVL, CLT and HCLT in order to evaluate their sound properties, in which the theoretical value of sound insulation was predicted by regarding the substances in wood cell wall as equivalence to specific medium based on Biot model, and the wood anatomical characteristics, such as the length and diameter of tracheid, diameter of pit, and porosity, were taken into account for determining the equivalent density and bulk modulus of elasticity of wood cell wall. By comparing the tested and predicted values of sound insulation, the conclusion were drawn as follows: the predicted values of sound insulation were significantly correlated with the tested values for LVL, CLT and HCLT. As for Masson pine and Southern pine, the adjacent of earlywood and latewood was considered as sandwich structure for the calculation of sound insulation. Meanwhile, the bonding interface was creatively introduced to improve the accuracy of sound insulation prediction. The transfer function involved in sound insulation prediction provide an effective method to characterize the sound insulation volume of wood composite in construction and decoration areas.
Research Progress on Repair and Reinforcement of Beams in Timber Building
Authors: Zhang Xiaofeng , Sun Youfu , Liu Mingbin , Yang Ruyuan
Published: March 2019

Timber building has been widely used for its renewable, excellent structural performance and aesthetic value. The “beam” is one of the most important components in the upper structure of a timber structure; beam as the main force component is under long-term loading may cause it to crack and resulting in a reduced safety factor. In this paper, the predecessors' research results are analyzed and summarized from the perspectives of the damage reinforcement methods of timber beams in ancient building and modern building, as well as the research hot-pots of modern timber beams, in order to lay the foundation for subsequent related research..
Optimization of bonding parameters of laminated wood using a novel bio-based RPF adhesive
Authors: Ren Xueyong , Shen Yinlan , Gao Ying , Zhang Derong , Chang Jianmin
Published: March 2019

Adhesive is the key component and factor for the manufacture of glulam, affected both the properties and cost of glulam product. Bio-based resorcinol-phenol-formaldehyde (BRPF) resin was developed by partly replacing the expensive resorcinol and phenol with the cheap biomass derived pyrolysis oil. The press process parameters and the dosage of adhesive and corresponding curing agent were selected as the factors and extensively studied. BRPF resin was successfully used to bond the laminas to produce glulam, and the optimized process parameters for the cold-pressing adhesion of BRPF resin with pine wood were obtained as follows: the cold-pressing pressure 1.4 MPa, the cold-pressing time 9 h, the amount of adhesive coating 320 g/m2, and the proportion of curing agent (poly-formaldehyde) 17%. The mechanical performances of laminated wood bonding with BRPF resin under the optimal condition were further verified. It is believed that the results obtained here will promote the use of bio-based resin in the bonding of laminated wood, and then contribute to the green manufacturing of glulam with lower cost.
Study on Temperature Control and Crack Prevention of Mass Concrete for Large Powerhouse Constructed in Cold Area
Authors: Sun Qiaorong , Ding Bingyong , Zheng Zaixin , Du Running , Qiang Sheng
Published: March 2019

Due to complex structure, large scale, and cold climate, the temperature field and stress field during construction of BoYi Station is different with ordinary mass concrete. Therefore the corresponding crack prevention method must be explored. In order to simulate the complicated construction course, cold climate, multiple materials and unusual structure, a finite element program is adopted. In 5 numerical simulation cases, different temperature control methods are tried to decrease the tensile stress of mass concrete. Based on the simulation analysis and combined with the engineering experience, the scheme and indexes of temperature control and crack prevention are recommended. The mainly measures are controlling pouring temperature, insulation of concrete surface, pipe cooling, block partition and extra steel bar reinforcement. The values of temperature indexes are sharply lower than that of ordinary hydropower station mass concrete. The suggested measures and indexes in this paper, which are various with season, structure position and material, may provide some reference to similar large hydropower station workshop in cold area.
Study on Fatigue Property of Cracked Steel Plate Strengthened by CFRP
Authors: Wu Xi-Zhi , Yang Wei-Kang , Zang Xian-Guo
Published: March 2019

This paper presents fatigue property of CFRP-strengthened cracked steel plate. Firstly, the finite element model of CFRP-strengthened cracked steel plate is established by using the cohesive zone model. With the finite element model, stress intensity factor of the crack-tipis calculated. Then, it gives the fatigue tests of cracked steel plate. According to the experimental data, the material constants C and n value sare obtained. The prediction fatigue life is calculated by the finite element model and Paris function and verified by the experimental data. The results show that the prediction fatigue life, calculated by the finite element model and the Paris formula, is consistent with the experimental fatigue life, which verifies the accuracy of our prediction model with finite element model and the Paris function.
Damage plasticity model for passively confined concrete
Authors: Li Ben-ben , Xiong Hai-bei , Jiang Jia-fei , Zhan Yang
Published: March 2019

This paper presents a modified concrete damage plasticity model (CDPM) for passively confined concrete within the concrete damage plasticity theory frame in ABAQUS. The modified CDPM can be used to simulate concrete under non-uniform passive confinement, for example, Fiber-reinforced polymer (FRP)-confined square concrete columns. The modification of CDPM includes a flow rule and a strain hardening/softening criterion in which dilation angle and yield stress are important parameters. Based on the true-triaxial experiment results of passively confined concrete, the dilation angle and yield stress were determined considering different confinement stiffness and non-uniform confinement stiffness ratio. Finally, the modified CDPM were incorporated in the ABAQUS model. The prediction of the finite element model of FRP-confined square concrete columns shows good prediction accuracy.
Study on toughness and toughening mechanism of cement-based fiber materials
Authors: Hu Huixiao , Li Qiang , Cao Lu
Published: March 2019

In order to improve the character of common cement mortar which are brittle and easily cracked, andtotake advantage of the local materials, abandoned fishing nets was used toform get the cement-based fiber materials. In this study, the influence of the amount and length of abandoned fishing nets on the mechanical properties of cement mortar and its mechanism were discussed. Four different lengths of abandoned fishing nets were adopted under four kinds of dosages to mix with mortar and make a total of 16 test blocks. Then the flexural strengths of the prepared test blocks were tested, and the load-deflection curve of the test block was obtained. The results showthat the residual strength after the test block after which reachesthe peak load in the flexural test generally increases with the increase of the fiber content and the length of the fiber, but when the dosage and length increase to a certain range, the influences becomecomplicated. The crack propagation simulation byAbaqus further revealed the reinforcement mechanism, and it can be concluded thatthe bridging between the fiber and the matrix has a great influence on the character toughness.
Experimental Study on Stress and Strain Characteristics of Solidified Clay under Seawater Condition
Authors: Zhiqiang WU , Zhengyin CAI , Kai XU , Zhizhou GENG , Yinghao HUANG , Xiaomei LI
Published: March 2019

This paper presents the results of a laboratory study on the stress-strain relationship of solidified clay formed in seawater corrosion condition. An automatic triaxial apparatus was used and the axial stress and strain was monitored continuously. The dry density was 1.0g/cm3, the cement contents were 4, 6, 8 and 10% by weight of dry soil particles, and the curing time was 28, 60 and 90 days respectively. Test results indicate that the stress strain relationship of cemented clay was affected by soil density, cement content and curing period. A behaviour of strain hardening to strain softening occurred with the increase of cement content. Strong structure will form in cemented clay when the admixture content is 10% or more. The increase in strength of the solidified foundation is resulted from the increase in internal friction angle and cohesive force. The cohesive force increases obviously with the increase of the cement content and the curing age, but the change of internal friction angle is not pronounced after reaching a certain value.
Analysis of plastic zones in surrounding rocks around a circular tunnel considering the effect of intermediate principal stress and heterogeneity
Authors: Deng Shuxin , Zheng Yonglai , Feng Lipo , Tuan Le Van , Yue Cuizhou , Wu Zhuorui
Published: March 2019

Based on a modified Mohr-Coulomb criterion with a non-uniform coefficient, a calculation method of plastic zone boundary of surrounding rocks in a circular tunnel in non-uniform stress field is established. Both the effects of intermediate principal stress and heterogeneity are studied. With the increase of the intermediate principal stress, the plastic zone size of the surrounding rocks will decrease first and then increase. Lateral pressure coefficient has an effect on the shape of the plastic zone. With the increase of lateral pressure coefficient, the plastic zone gradually becomes uniform, and the failure of surrounding rock develops upward and downward from both sides. As non-uniform coefficient increases, the material is more uniform and the effect of intermediate principal stress on the plastic zone is less significant. If the effect of intermediate principal stress is not taken into account, the calculation results tend to be consistent with results calculated by the Mohr-Coulomb criterion, which are considered to be conservative.
Research on Uplift Bearing Performance of Assembled Steel Pipe Pile used in Transmission Lines in Mountainous Terrain
Authors: Zhou Kun , Chen Linhua , Gu Xiangyu , Zhang Qi
Published: March 2019

Assembled steel pipe pile, which is a novel pile foundation, is developed in the paper. The ultimate uplift bearing capacity of the pile is proposed, and simulation by Plaxis3D and the corresponding experiment are performed to verify the theory. In the simulation, ultimate uplift bearing capacity of the assembled steel pipe pile and ultimate lateral frictional resistance of the interface of pile-soil increases with the increasing of the strength and stiffness of the interface of pile-soil, and with the increasing of length-diameter ratio, ultimate uplift bearing capacity of the assembled steel pipe pile increases while the ultimate lateral frictional resistance decreases gradually. The ultimate lateral friction is influenced by both of the strength of the soil around the pile and the interface of pile-soil, and the ultimate uplift bearing capacity obtained by simulation and theoretical calculation are close. Long-gauge FBG sensors are used in the experiment for measuring the longitudinal strain of the pile, and the error of ultimate uplift bearing capacity between the results of experiment and theory is less than 10%.
Skid resistance demands of asphalt pavement during the braking process of autonomous vehicles
Authors: Binshuang Zheng , Jiaying Chen , Runmin Zhao , Xiaoming Huang
Published: March 2019

As the main operationality of AVs, the braking property is directly related to traffic safety. Major traffic accidents are often related to the braking distance, the side slip and hydroplaning during the emergency braking, which depends on the pavement skid resistance. Therefore, the estimation to relate AVs braking distance requirements with pavement peak friction coefficient to ensure a safe driving condition on expressway is of high practical significance. In this paper, the effect of AVs on braking performance parameters and dynamic friction on tire-pavement interaction are investigated. Based on the field test of the Coastal highway in Jiangsu province of China, this paper proposes an algorithm to determine time-dependent braking distance of AVs considering pavement frictional properties. According to the algorithm, an AVs braking system is provided to reach the maximum braking force for improving the AVs traffic safety. Furthermore, it revises the braking distance formula of Design Specification for Highway Alignment and the skid resistance threshold adopted by Technical Specifications for Maintenance of Highway Asphalt Pavement.
Application of evolutionary algorithms to optimize cooling channels
Authors: Nagaiah Narasimha R. , Geiger Christopher D.
Published: March 2019

The design and development is a complex, repetitive, and more often difficult task, as design tasks comprising of restraining and conflicting relationships among design variables with more than one design objectives. Conventional methods for solving more than one objective optimization problems is to build one composite function by scalarizing the multiple objective functions into a single objective function with one solution. But, the disadvantages of conventional methods inspired scientists and engineers to look for different methods that result in more than one design solutions, also known as Pareto optimal solutions instead of one single solution. Furthermore, these methods not only involved in the optimization of more than one objectives concurrently but also optimize the objectives which are conflicting in nature, where optimizing one or more objective affects the outcome of other objectives negatively. This study demonstrates a nature-based and bio-inspired evolutionary simulation method that addresses the disadvantages of current methods in the application of design optimization. As an example, in this research, we chose to optimize the periodic segment of the cooling passage of an industrial gas turbine blade comprising of ribs (also known as turbulators) to enhance the cooling effectiveness. The outlined design optimization method provides a set of tradeoff designs to pick from depending on designer requirements.
Das Schlafapnoe-Syndrom
Authors: Schmid HP Eva C.
Published: March 2019

Vermehrt auftretende Atemstillstände im Schlaf, die mindestens 10 Sekunden dauern, kennzeichnen das Schlafapnoe-Syndrom (SAS). Man unterscheidet zwischen dem obstruktiven und zentralen Apnoemuster, wobei es auch eine gemischte Form gibt. Unbehandelt kann das SAS gesundheitliche Konsequenzen mit sich bringen.
Wenn Schlaf zum Problem wird
Authors: Weeß Hans-Günter
Published: March 2019

Die American Academy of Sleep Medicine differenziert mehr als 80 Schlafstörungen klinisch-wissenschaftlich. Diese werden in 7 Hauptgruppen unterteilt. Die häufigsten Schlafstörungen in Deutschland sind die Insomnien, rund 6 % der Bevölkerung sind betroffen. Die Folgen können das Berufs- und Alltagsleben beeinträchtigen. Bei Insomnien ist eine geeignete Therapie aufgrund meist vielfältiger Ursachen multimodal. Die Kognitive Verhaltenstherapie hat sich hierbei bewährt.
Süßer (und lebenswichtiger) Schlaf
Authors: Hödlmoser Kerstin
Published: March 2019

Summary: Um Schlafproblemen vorzubeugen oder sie zu behandeln, ist es wichtig, durch ausreichende Information über den Schlaf Missverständnissen und Mythen vorzubeugen. Schlaf wird in vier Stadien unterteilt: NREM (N1, N2, N3) und REM. Sie folgen zyklisch aufeinander und sind durch verschiedene physiologische Parameter gekennzeichnet. Die drei wichtigsten Funktionen des Schlafs sind: Erholung und Regeneration, Informationsverarbeitung und Entwicklung. Laut aktueller Forschung hat der Schlaf viele weitere (zum Teil noch unbekannte) Aufgaben inne.
The Extended Barthel Index (EBI) can Be Reported as a Unidimensional Interval-Scaled Metric – A Psychometric Study
Authors: Maritz Roxanne , Tennant Alan , Fellinghauer Carolina Saskia , Stucki Gerold , Prodinger Birgit ,   on behalf of the NRP74 StARS clinics
Published: March 2019

Background The Extended Barthel Index (EBI), consisting of the original Barthel Index plus 6 cognitive items, provides a tool to monitor patients’ outcomes in rehabilitation. Whether the EBI provides a unidimensional metric, thus can be reported as a valid sum-score, remains to be examined.

Objective To examine whether the EBI can be reported as unidimensional interval-scaled metric for neurological and musculoskeletal rehabilitation.

Methods Rasch analysis of a calibration sample of 800 cases from neurological or musculoskeletal rehabilitation in 2016 in Switzerland.

Results In the baseline analysis no fit to the Rasch Model was achieved. When accommodating local dependencies with a testlet approach satisfactory fit to the Rasch Model was achieved, and an interval scale transformation table was created.

Conclusion The results support the reporting of adapted EBI total scores for both rehabilitation groups by applying the interval scaled transformation table presented in this study.
Labordiagnostik bei entzündlichen Gelenkerkrankungen
Authors: Mierau Dr. rer. nat. Rudolf
Published: March 2019

Das Labor leistet auf mehreren Gebieten Beiträge in der Primärdiagnostik entzündlicher Gelenkerkrankungen und begleitet zudem auch deren Management im Verlauf. Entzündungsparameter helfen, zwischen primär entzündlichen und nicht entzündlichen rheumatischen Erkrankungen zu unterscheiden, sind allerdings sowohl bei der rheumatoiden Arthritis (RA) als auch bei den Spondyloarthritiden nicht in jedem Fall erhöht. Autoantikörper sind bedeutende Diagnostik-Bausteine vor allem bei der RA sowie bei den Kollagenosen. Die Synovia-Analyse hilft bei der Beurteilung der Entzündungsaktivität und liefert ätiologische Hinweise z. B. bei Kristallarthropathien. Genetische Risikofaktoren für Gelenkerkrankungen sind in großer Zahl bekannt; diagnostisch verwertet wird von diesen aber nur die Bestimmung des HLA-B27-Merkmals in der Diagnostik der Spondyloarthritiden.
IgG4-assoziierte Aortitis bei einem sechsjährigen Jungen
Authors: Youssef H , Lutz T , Helling-Bakki A
Published: March 2019

Hintergrund

IgG4-related disease (IgG4-RD) ist eine inflammatorisch fibrosierende Systemerkrankung, die sich in unterschiedlichsten Organsystemen manifestieren kann und einer immunsuppressiven Therapie bedarf. Im Kindes- und Jugendalter handelt es sich um eine Rarität.

Fall

Bei einem Sechsjährigen wurde nach einer Aortenteilresektion mit Prothesenersatz anhand des hier gewonnenen histologischen Materials der Verdacht auf eine Großgefäß-vaskulitis gestellt. Anamnestisch bestanden in den ersten zwei Lebensjahren rezidivierende Analabszesse. Im Alter von drei Jahren wurde eine solitäre Nierenzyste mit konsekutiver Harntransportstörung diagnostiziert und marsupialisiert. Mit fünf Jahren fiel ein arterieller Hypertonus auf, bei dessen Abklärung eine hochgradige Mehrstufenstenose der thorakalen und der abdominellen Aorta diagnostiziert wurde. Laborchemisch zeigten sich deutlich erhöhte IgG4-Spiegel. Im sechsten Lebensjahr entwickelte der Junge begleitend zum Beginn einer immunsuppressiven Therapie eine Hyperthyreose.

Schlussfolgerung

Anhand der allgemeinen und klinischen Diagnosekriterien kann in diesem Fall bei Vorliegen einer inflammatorischen abdominellen Aortitis und entsprechender IgG4-Erhöhung die im Kindesalter äußerst seltene Diagnose einer IgG4-assoziierten Erkrankung gestellt werden, allerdings bei Nichterfüllen der histologischen Kriterien.
Vom Pflanzenreich ins Schlummerland
Authors: Stern Cornelia
Published: March 2019

Die Pflanzenheilkunde bietet verschiedene Heilpflanzen für den Einsatz bei Schlafstörungen: unter anderem Baldrian, Kalifornischen Mohn, Hafer, Passionsblume und Hopfen. Nicht jede Schlafpflanze ist für jeden Patienten gleich gut geeignet. Die Signaturenlehre hilft, die richtige je nach Ursache, individueller Symptomatik und Situation des Patienten auszusuchen. Die meisten der vorgestellten Schlafpflanzen sind auch von der Rationalen Phytotherapie mit den Indikationen Unruhezustände und/oder Schlafstörungen anerkannt.
Validierung einer deutschen, adaptierten Fassung der Self-Stigma of Depression Scale (SSDS) zur Messung von Selbststigmatisierung bei Personen mit Depression (SSDS-D)
Authors: Goepfert Nele Cornelia , Lehr Karla , Zillich Lea , von Heydendorff Steffen Conrad , Dreßing Harald , Bailer Josef
Published: March 2019

Die Self-Stigma of Depression Scale (SSDS) erfasst mit 16 Items das von der befragten Person antizipierte Selbststigma für den hypothetischen Fall, dass sie eine Depression hätte. Für die Befragung von Patienten ist die Erfassung des tatsächlich erlebten Selbststigmas sinnvoller. Ziel der Studie war folglich die Entwicklung und Validierung einer Patientenversion der SSDS, um das erlebte Selbststigma bei Personen mit Depression adäquat erfassen zu können. Alle Items wurden neu übersetzt und in den Indikativ gesetzt. Die Skala wurde Self-Stigma of Depression Scale für Personen mit Depression genannt und mit SSDS-D (D für Depression) abgekürzt. Faktorstruktur, interne Konsistenz sowie Konstruktvalidität wurden in 2 unabhängigen klinischen Stichproben (NA=550; NB=180) an Personen mit Depression überprüft. In Stichprobe A konnte – mit Ausnahme eines Items – die Originalstruktur mit den 4 Faktoren Scham, Eigene Schuldzuschreibung, Hemmungen bei Hilfesuche und Soziale Unzulänglichkeit mittels explorativer Faktorenanalyse repliziert werden. Konfirmatorische Faktorenanalysen in Stichprobe B führten bei dem empirisch hergeleiteten Modell zu einem deskriptiv besseren Fit als beim alternativ getesteten Originalmodell. Die interne Konsistenz der neu gebildeten SSDS-D-Subskalen war zufriedenstellend bis sehr gut. Kontrolliert für Depressivität fanden sich erwartungskonforme Zusammenhänge der SSDS-D mit Selbstwert und anderen Selbststigma-Skalen, was die Konstruktvalidität der SSDS-D belegt. Die SSDS-D erwies sich als valides und reliables Instrument zur Erfassung von erlebtem Selbststigma bei Personen mit Depression. Sie kann bei klinischen Stichproben genutzt werden, um Korrelate von Selbststigma zu identifizieren und theoretische Modelle sowie die Wirksamkeit von Interventionen zu testen.
Auf einen Blick: Schlafstörungen
Authors: Weeß Hans-Günter
Published: March 2019

Als Heilpraktiker behandelt man vor allem Ein- und Durchschlafstörungen. Differenzialdiagnostisch kann es aber auch wichtig sein, andere Schlafstörungen zu erkennen und den Patienten gegebenenfalls an einen Facharzt weiterzuvermitteln. Nach der American Academy of Sleep Medicine werden Schlafstörungen in 7 Hauptgruppen eingeteilt: Insomnien, schlafbezogene Atmungsstörungen, Hypersomnien, zirkadiane Rhythmusschlafwachstörungen, Parasomnien, schlafbezogene Bewegungsstörungen und andere Schlafstörungen.