bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical simulation of pounding damage to caisson under storm surge
Authors: Yu Chen
Published: June 2018

In this paper, a new method for the numerical simulation of structural model is proposed，which is employed to analyze the pounding response of caissons subjected to storm surge loads．According to the new method，the simulation process is divided into two steps. Firstly, the wave propagation caused by storm surge is simulated by the wave-generating tool of Flow-3D, and recording the wave force time history on the caisson. Secondly，a refined 3D finite element model of caisson is established，and the wave force load is applied on the caisson according to the measured data in the first step for further analysis of structural pounding response using the explicit solver of LSDYNA. The whole simulation of pounding response of a caisson caused by “Sha Lijia” typhoon is carried out. The results show that the different wave direction results in the different angle caisson collisions, which will lead to different failure mode of caisson, and when the angle of 60 between wave direction and front/back wall is simulated, the numerical pounding failure mode is consistent with the situation.
Urban Flood Prevention and Early Warning System in Jinan City
Authors: Feng Shiyuan , Li Qingguo
Published: June 2018

The system construction of urban flood control and disaster reduction in China is facing pressure and challenge from new urban water disaster. Under the circumstances that it is difficult to build high standards of flood protection engineering measures in urban areas, it is particularly important to carry out urban flood early warning. In Jinan City, a representative inland area, based on the index system of early warning of flood in Jinan urban area, the method of fuzzy comprehensive evaluation was adopted to evaluate the level of early warning. Based on the cumulative rainfall of 3 hours, the CAflood simulation results based on cellular automaton model of urban flooding were used as evaluation indexes to realize the accuracy and integration of urban flood control early warning.
Numerical Simulation Study of Booming Effect in Fast Currents of Inland River
Authors: Chen Rongchang , Liu Chen , Luo Xiaofeng , Shen Wei
Published: June 2018

In the downstream tidal section of the Yangtze River, nine kinds of combinations of hydrological environmental conditions are considered, including the annual average runoff flow, the annual average peak flow and the flood control design flow, as well as the three conditions of spring, medium and neap tides. By means of the numerical simulation method, the effective performance parameter values for conventional intercepting boom under different environmental conditions are obtained by simulating 9 kinds of maximum current speed to withstand, Max.CS, respectively. The results show that, in the downstream fast current tidal section of the Yangtze River, for the boom performance index of Max.CS, the relatively extensive applicability value should be 3.0kn under the condition of the annual average runoff flow; 4.0Kn should be selected under the condition of the annual average peak flow; and 4.5Kn should be selected under the flood control design flow. This study can provide technical support for the design, selection and use of booms in downstream waters of the Yangtze River.
Effect of deflector curvature on hydrodynamic performances of a double-slotted cambered otter-board
Authors: WANG Lei , Wang Lu Min , Shi Jian Gao , Yu Wen Wen , Qi Guang Rui , Zhang Xun , Zhang Rong Jun , Zhang Tian Shu
Published: June 2018

The effect of deflector curvature on hydrodynamic performances of a double-slotted cambered otter-board was investigated using engineering models in a wind tunnel. Four different curvature (0.06,0.09, 0.12 and 0.15) were evaluated at a wind speed of 28 m/s. Parameters measured included: drag coefficient Cx, lift coefficient Cy, pitch moment coefficient Cm, center of pressure coefficient Cp , over a range of angle of attack (0° to 70°). These coefficients were used in analyzing the differences in the performance among the four otter-board models. Results showed that the maximum lift coefficient Cy of the otter-board model with the curvature (0.06) of two deflectors was highest (2.020 at °=55°). The maximum Cy/Cx of the otter-board with the curvature (0.12) of two deflectors was highest (3.655 at °=22.5°). A comparative analysis of Cm and Cp showed that the stability of otter-board model with the curvature (0.12) of two deflectors is better in pitch, and the stability of otter-board model with the curvature (0.06) of two deflectors is better in roll. The findings of this study can offer useful reference data for the structural optimization of otter-boards for trawling.
Effect of panel shape on hydrodynamic performances of vertical v-shaped double- slotted cambered otter-board
Authors: Wang Lei , Zhang Xun , Wang Lu Min , Huang Hong Liang , Zhang Yu , Liu Yong Li , Feng Wei Dong , Zhang Rong Jun
Published: June 2018

The effect of panel shape on hydrodynamic performances of a vertical v-shaped double-slotted cambered otter-board was investigated using engineering models in a wind tunnel. Three different shape panels (rhomboid, left trapezoid and isosceles trapezoid) were evaluated at a wind speed of 28 m/s. Parameters measured included: drag coefficient Cx, lift coefficient Cy, pitch moment coefficient Cm, center of pressure coefficient Cp , over a range of angle of attack (0° to 70°). These coefficients were used in analyzing the differences in the performance among the three otter-board models. Results showed that the maximum lift coefficient Cy of the otter-board model with the isosceles trapezoid shape panels was highest (2.103 at α=45°). The maximum Cy/Cx of the otter-board with the rhomboid shape panels was highest (3.976 at α=15°). A comparative analysis of Cm and Cp showed that the stability of otter-board model with the isosceles trapezoid shape panels is better in pitch, and the stability of otter-board model with the left trapezoid shape panels is better in roll. The findings of this study can offer useful reference data for the structural optimization of otter-boards for trawling.
Quantitative analyzing for As’s transferring process in coastal waters in Jiaozhou Bay
Authors: Yang Dongfang , Wang Qiang , Zhou Wei , Su Chunhua , Zhu Sixi
Published: June 2018

This paper quantified the horizontal and vertical transferring processes of As in coastal waters in the southwest and the bay mouth of Jiaozhou Bay using investigation data in July and October 1982. Results showed that the horizontal absolute loss amounts of As contents in surface waters were 0.20-2.44 μg L-1, and the horizontal relative loss amounts in surface waters were 19.23%-87.14%, respectively. The horizontal absolute loss amounts of As contents in bottom waters were 0.27-2.44 μg L-1, and the horizontal relative loss amounts in bottom waters were 25.00%-54.46%, respectively. The vertical absolute dilution amounts of As contents were 0.02-0.28 μg L-1, and the vertical relative dilution amounts were 1.78-16.66%. The vertical absolute accumulation amounts of Pb contents were 0.10-0.86 μg L-1, and the vertical relative accumulation amounts were 7.35%-35.83%. The vertical absolute dilution amount and vertical relative dilution amount of As’s contents were 0.20-0.76 μg L-1 and 19.23%-27.14%, respectively. The vertical absolute accumulation amount and vertical relative accumulation amount of As’s contents were 0.28-4.12 μg L-1 and 25.00%-91.96%, respectively. The changes of As contents in surface and bottom waters were determined by the source inputs of As and the transferring distance of As from the terrisgenous sources.
Calculation of crack stress density of cement base materials
Authors: Chun-e Sui
Published: June 2018

In this paper, the fracture load of cement paste with different water cement ratio, different mineral admixtures, including fly ash, silica fume and slag, is obtained through experiments. the three-dimensional fracture surface is reconstructed and the three-dimensional effective area of the fracture surface is calculated. the effective fracture stress density of different cement paste is obtained. The results show that the polynomial function can accurately describe the relationship between the three-dimensional total area and the tensile strength
Numerical Simulations of SCR DeNOx System for a 660MW coal-fired power station
Authors: Yongqiang Deng , Zhongming Mei , Yijun Mao , Nianping Liu , Guoming Yin
Published: June 2018

Aimed at the selective catalytic reduction (SCR) DeNOx system of a 660 MW coal-fired power station, which is limited by low denitrification efficiency, large ammonia consumption and over-high ammonia escape rate, numerical simulations were conducted by employing STAR-CCM+ (CFD tool). The simulations results revealed the problems existed in the SCR DeNOx system. Aimed at limitations of the target SCR DeNOx system, factors affecting the denitrification performance of SCR, including the structural parameters and ammonia injected by the ammonia nozzles, were optimized. Under the optimized operational conditions, the denitrification efficiency of the SCR system was enhanced, while the ammonia escape rate was reduced below 3ppm. This study serves as references for optimization and modification of SCR systems.
Fixed-speed and Variable-speed Pumped Storage Dispatch Model in Power Systems with High Renewable Penetration
Authors: Yuan Bo , Zong Jin , Xu Zhicheng
Published: June 2018

According to different operating characteristics of pumped storage fixed speed unit and variable speed unit, a joint dispatching model of pumped storage unit and other types of units based on mixed integer linear optimization is constructed. The model takes into account the operating conditions, reservoir capacity, cycle type and other pumped storage unit constraints, but also consider the frequent start and stop and the stability of the operation of the unit caused by the loss. Using the Cplex solver to solve the model, the empirical example of the provincial power grid shows that the model can effectively arrange the pumping storage speed and the dispatching operation of the variable speed unit under the precondition of economic life of the unit, and give full play to the function of peak shaving and accommodating new energy. Because of its more flexible regulation characteristics of power generation and pumping conditions, the variable speed unit can better improve the operating conditions of other units in the system and promote the new energy dissipation.
Research on the Direction of China's Energy Development and Coping Strategies Based on the Trend of World Energy Development
Authors: Zhang Lixin , Tao Ye , Jiang Yan , Ma Ju
Published: June 2018

To realize the modernization of the national economy, it is necessary to develop energy science and technology for China,which is third largest countries in the world.The rapid development of science and technology has promoted the continuous transformation of the global energy industry. By analyzing the trend of energy development in the world today, this paper discusses the challenges that the global energy development facing and the situation and tasks faced by China's energy sustainable development, and looks forward to China's strategies to cope with the development of the world's energy.
Construction of Multimodal Transport Information Platform
Authors: Wang Ya , Cheng Yu , Zhao Zhi
Published: June 2018

With the rapid development of economy, the volume of transportation in China is increasing, the opening process of the market is accelerating, the scale of enterprises is expanding, the service quality is being improved, and the container multimodal transport is developing continuously.The hardware infrastructure of container multimodal transport is improved obviously, but the network platform construction of multimodal transport is still insufficient.Taking Shandong region of China as an example, the present situation of container multimodal transport in Shandong area can no longer meet the requirement of rapid development of container, and the construction of network platform needs to be solved urgently. Therefore, this paper will briefly describe the conception of construction of multimodal transport network platform in Shandong area.In order to achieve the rapid development of multimodal transport.
Thermal distribution analysis of inner defects in TSV
Authors: Jiang Chuan Kai , Nie Lei , Jia Wen , Zhong Yu Ning
Published: June 2018

In order to uncover the external manifestations of TSV internal defects, the finite element models of typical internal defects, which were filling missing, axial cavity and end cavity, were established. The thermal analysis was carried out using thermoelectric coupling method. The temperature distribution of TSV with and without defects were obtained. And the temperature variation profiles on the defined paths of TSV layer were also analyzed. The analysis indicated that all the defective TSV showed distinct temperature distribution with the defect-free TSV. Among three typical defects, TSV with filling missing showed the most obvious difference on the temperature distribution and path variation. TSV with end cavity has relatively weak affect and the slightest defect was TSV with axial cavity. Therefore, it could be seen that the external temperature difference caused by the internal defects of TSV could provide effective information for the identification and detection in TSV with internal defects.
Research on the Mode of University-Enterprise Cooperation to Promote Engineering Students' Employment
Authors: Hui Yan , Lihua Sun
Published: June 2018

The employment of university students has become a hot issue of concern to the whole society. Promoting the employment of university students is a top priority for higher education institutions. University-enterprise cooperation is an important trend in the development of modern higher education. It is also an important channel for promoting the employment of university students, especially for engineering students. Through an in-depth analysis of the status quo of employment of university graduates, this paper proposes four modes of university-enterprise cooperation to promote university graduates’ employment: The post-employment cooperation model, the professional internship cooperation model, the second classroom expansion cooperation model and the enterprise-oriented recruitment model, and further proposed the countermeasures to strengthen the cooperation between university and enterprise in order to promote the employment of university students.
Vortex valve
Authors: Adámek Karel , Kolář Jan , Peukert Pavel
Published: June 2018

The paper deals with a flow field inside the so-called vortex valve, used as an outlet device on retention reservoirs for retention of rainstorms and later slow outflow into sewerage etc. The system is very simple, without moving parts. Using the method of numerical flow simulation, the unusual flow characteristic Δp = f(Q), containing two branches, is explained. Further, there it is studied influence of both inlet/outlet opening sizes on the form of the characteristic. Results can be used for designing the new model series of valves for various flows.
Experimental Investigation of Vortex Structures in Wake of Hyperboloid-Shaped Model by Means of 2D Particle Image Velocimetry Measurement
Authors: Barraclough V. , Novotný J. , Šafařík P.
Published: June 2018

This paper deals with flow around a bluff body of hyperboloid shape. It consists of results gathered in the course of research by means of Particle Image Velocimetry (PIV). The experiments were carried out by means of low-frequency 2D PIV in a range of Reynolds numbers from 40000 to 50000. A hyperboloid-shaped model was measured in a wind tunnel with a modelled atmospheric boundary layer (and additionally, in a low-speed wind tunnel with low turbulence). The model was tested in a subcritical range of Reynolds numbers and various planes in a wake of the model were captured with the intention of getting an estimation of 3D flow structures. The tunnel with the modelled atmospheric boundary layer has a high rate of turbulence, so the influence of the turbulence of incoming flow on the wake could be outlined. The ratio of the height of the model to a thickness of the modelled boundary layer in the tunnel was 1/3, meaning the turbulence in the boundary layer strongly influenced the flow around the model; it suppresses the wake which leads to a lot shorter area of recirculation than low turbulence incoming flow would cause.
Mathematical Simulation of Drying Process of Fibrous Material
Authors: Blejchař Tomáš , Raška Jiří , Jablonská Jana
Published: June 2018

The article describes mathematical simulation of flowing air through porous zone and water vaporisation from mentioned porous area which actually represents dried fibrous material - cotton towel. Simulation is based on finite volume method. Wet towel is placed in pipe and hot air flow through the towel. Water from towel is evaporated. Simulation of airflow through porous element is described first. Eulerian multiphase model is then used for simulation of water vaporisation from porous medium. Results of simulation are compared with experiment. Ansys Fluent 13.0 was used for calculation.
Investigation of droplet nucleation in CCS relevant systems – design and testing of the expansion chamber
Authors: Čenský Miroslav , Hrubý Jan , Vinš Václav , Hykl Jiří , Šmíd Bohuslav
Published: June 2018

A unique in-house designed experimental apparatus for investigation of nucleation of droplets in CCS relevant systems is being developed by the present team. The apparatus allows simulating various processes relevant to CCS technologies. Gaseous mixtures with CO2 are prepared in a Mixture Preparation Device (MPD) based on accurate adjustment of flow rates of individual components [EPJ Web of Conferences 143, 02140 (2017)]. The mixture then flows into an expansion chamber, where it undergoes a rapid adiabatic expansion. As a consequence of adiabatic cooling, the mixture becomes supersaturated and nucleation and simultaneous growth of droplets occurs. In this study, we describe the design and testing of the expansion part of the experimental setup. The rapid expansion was realized using two valve systems, one for low pressures (up to 0.7 MPa) and the other for high pressures (up to 10 MPa). A challenge for a proper design of the expansion system is avoiding acoustic oscillations. These can occur either in the mode of Helmholtz resonator, where the compressible gas in the chamber acts as a spring and the rapidly moving gas in the valve system as a mass, or in the “flute” mode, where acoustic waves are generated in a long outlet tubing.
Experimental investigation of five parallel plane jets with variation of Reynolds number and outlet conditions
Authors: Daubner Tomas , Kizhofer Jens , Dinulescu Mircea
Published: June 2018

This article describes an experimental investigation in the near field of five parallel plane jets. The study applies 2D Particle Image Velocimetry (PIV) for ventilated and unventilated jets, where ventilated means exiting into a duct with expansion ratio 3.5 and unventilated means exiting to the free atmosphere. Results are presented for Reynolds numbers 1408, 5857 and 10510. The Reynolds number is calculated for the middle channel and is based on the height of the nozzle (channel) equivalent diameter 2h. All characteristic regions of the methodology to describe multiple interacting jets are observed by the PIV measurements - converging, merging and combined. Each of the five parallel channels has an aspect ratio of 25 defined as nozzle width (w) to height (h). The channels have a length of 185 times the channel height guaranteeing a fully developed velocity profile at the exit from the channel. Spacing between the single plane jets is 3 times the channel height. The near field of multiple mixing jets is depended on outlet nozzle geometry. Blunt geometry of the nozzle was chosen (sudden contraction).
Compressed Air Savings During Cooling and Cleaning of Product
Authors: Dvořák Lukáš , Fojtášek Kamil , Holiš Petr
Published: June 2018

The paper deals with possibilities of reduction of compressed air consumption during cooling of drill bit and pressure cleaning of products. First part is focused on the experimental verification of the air consumption of the production machine. On the basis of the experiment in second part of paper the modifications of machine which are aimed to reduction of air consumption are proposed.
Experimental investigation of centrifugal fans for personal protection equipment – effect of used 3D printing technologies
Authors: Dvořák Václav , Votrubec Radek , Šafka Jiří , Kracík Jan
Published: June 2018

The aim of the research is experimental investigation of centrifugal fans for a personal protection equipment. The aim of the fan is to drive the contaminated air containing harmful or irritating particles through the filters and then into the mask of workers, such as a fireman, a labourer or a lab worker. The fan is measured on the test stand, the characteristics and performances are evaluated, i.e. the dependencies of the working pressure on the flow rate. The characteristics are measured for three constant speed settings. The characteristics of the wheels produced by the different 3D printing technology are compared. It is found that the production technology has only a minimal effect, the performance of the wheels is more influenced by the position of the impeller on the motor shaft and hence by the mutual position of the impeller and the diffuser.
CFD analysis of a twin scroll radial turbine
Authors: Fürst Jiří , Žák Zdenĕk
Published: June 2018

The contribution deals with the application of coupled implicit solver for compressible flows to CFD analysis of a twin scroll radial turbine. The solver is based on the finite volume method, convective terms are approximated using AUSM+up scheme, viscous terms use central approximation and the time evolution is achieved with lower-upper symmetric Gauss-Seidel (LU-SGS) method. The solver allows steady simulation with the so called frozen rotor approach as well as the fully unsteady solution. Both approaches are at first validated for the case of ERCOFTAC pump [1]. Then the CFD analysis of the flow through a twin scroll radial turbine and the predictions of the efficiency and turbine power is performed and the results are compared to experimental data obtained in the framework of Josef Božek – Competence Centre for Automotive Industry.
Study on the impulsive pressure of tank oscillating by force towards multiple degrees of freedom
Authors: Hibi Shigeyuki
Published: June 2018

Impulsive loads should be excited under nonlinear phenomena with free surface fluctuating severely such as sloshing and slamming. Estimating impulsive loads properly are important to recent numerical simulations. But it is still difficult to rely on the results of simulations perfectly because of the nonlinearity of the phenomena. In order to develop the algorithm of numerical simulations experimental results of nonlinear phenomena are needed. In this study an apparatus which can oscillate a tank by force was introduced in order to investigate impulsive pressure on the wall of the tank. This apparatus can oscillate it simultaneously towards 3 degrees of freedom with each phase differences. The impulsive pressure under the various combinations of oscillation direction was examined and the specific phase differences to appear the largest peak values of pressure were identified. Experimental results were verified through FFT analysis and statistical methods.
Development of Modified Incompressible Ideal Gas Model for Natural Draft Cooling Tower Flow Simulation
Authors: Hyhlík Tomáš
Published: June 2018

The article deals with the development of incompressible ideal gas like model, which can be used as a part of mathematical model describing natural draft wet-cooling tower flow, heat and mass transfer. It is shown, based on the results of a complex mathematical model of natural draft wet-cooling tower flow, that behaviour of pressure, temperature and density is very similar to the case of hydrostatics of moist air, where heat and mass transfer in the fill zone must be taken into account. The behaviour inside the cooling tower is documented using density, pressure and temperature distributions. The proposed equation for the density is based on the same idea like the incompressible ideal gas model, which is only dependent on temperature, specific humidity and in this case on elevation. It is shown that normalized density difference of the density based on proposed model and density based on the nonsimplified model is in the order of 10-4. The classical incompressible ideal gas model, Boussinesq model and generalised Boussinesq model are also tested. These models show deviation in percentages.
Large-Eddy Simulation of Internal Flow through Human Vocal Folds
Authors: Lasota Martin , Šidlof Petr
Published: June 2018

The phonatory process occurs when air is expelled from the lungs through the glottis and the pressure drop causes flow-induced oscillations of the vocal folds. The flow fields created in phonation are highly unsteady and the coherent vortex structures are also generated. For accuracy it is essential to compute on humanlike computational domain and appropriate mathematical model. The work deals with numerical simulation of air flow within the space between plicae vocales and plicae vestibulares. In addition to the dynamic width of the rima glottidis, where the sound is generated, there are lateral ventriculus laryngis and sacculus laryngis included in the computational domain as well. The paper presents the results from OpenFOAM which are obtained with a large-eddy simulation using second-order finite volume discretization of incompressible Navier-Stokes equations. Large-eddy simulations with different subgrid scale models are executed on structured mesh. In these cases are used only the subgrid scale models which model turbulence via turbulent viscosity and Boussinesq approximation in subglottal and supraglottal area in larynx.
Numerical modelling of turbulent transition in complex geometries
Authors: Louda Petr , Příhoda Jaromír , Kozel Karel
Published: June 2018

The work deals with numerical simulation of laminar-turbulent transition in transonic flows in turbine cas-cades. The 3D cascade geometry as well as 2D model cascade in a wind tunnel is simulated. The γ-ζ transition model is based on empirical criteria for start of the transition. The implementation of the model is discussed including re-formulation of the criterion for transition on separation bubble.
Experimentally determined distribution of granular-flow characteristics in collisional bed load transport
Authors: Matoušek Václav , Zrostlík Štěpán , Fraccarollo Luigi , Prati Anna , Larcher Michele
Published: June 2018

A series of laboratory experiments on turbulent open-channel two-phase flow in a form of intense bed load transport is reported. Measurements in a laboratory tilting flume included camera based imaging techniques to identify the structure of the flow at the local level. Obtained experimental distributions of two-phase flow related parameters - granular velocity, concentration, and temperature - across a collisional transport layer are discussed. The results are analysed together with additional measured quantities (discharges of mixture and grains, flow depth, bed slope etc). Our major goal is to evaluate the distribution of granular stresses across the transport layer with a special attention paid to the interface between the transport layer and the bed. Furthermore, comparisons are discussed between the experimental results and predictions produced by suitable kinetic-theory based models.
Clocking of stators in one and half stage of axial steam turbine
Authors: Němec Martin , Jelínek Tomáš , Milčák Petr
Published: June 2018

An investigation of one and half axial turbine stage configuration was carried out in a closed-loop wind tunnel. The investigation was addressed to that impact how the previous stage outlet flow field influences the flow structures in the next stator in steam multistage turbines. The stage - stator interaction has been studied in this work. The detailed measurement with a pneumatic probes and fast response pressure probes behind the rotor and the second stator were performed to gain the useful data to analyze the impact. The detailed flow field measurement was carried out in the nominal stage regime (given by the stage isentropic Mach number 0.3 and velocity ratio u/c 0.68). The clocking effect of the stators is discussed and detailed unsteady flow analysis is shown.
Dustproof cooling of the electrical box
Authors: Nemec Patrik , Kaduchová Katarína , Malcho Milan
Published: June 2018

In present are electrical boxes cooled by air through the intake hole on the bottom electrical box to the box space with electrotechnical elements and exhaust through the hole at the top to the surrounding by natural convection. This cooling method is effective but operate with the risk of contamination electrotechnical elements by dust sucking from surrounding air. The goal of this work is solution of the dustproof cooling of the electrical box by natural convection. The work deal with design of the device with the heat transfer by the phase change of the working fluid and experimental measuring its thermal performance at the cooling electrotechnical elements loaded by heat 1 200 W in the dustproof electrical box.
Stand Alone PV House Design for Maximum Power Output in Sydney Australia Metropolitan Area
Authors: Nassereddine M. , Rizk J. , Hellany A. , Nagrial M. , Elrafhi A. , Obeid Z. , Hajar K.
Published: June 2018

Nowadays, a strong link exists between human comfort and electrical power. Abundant doings are not possible without the support of the electrical energy. Driven by the human obligation to save the environment, the installation of PV solar system increased dramatically in the past numerous years. The installation can be grid connected or standalone system. These micro-grid situations are installed world-wide and currently are contributing to the local electrical network. To maximize the use of the generated solar system, numerous system installed energy storage in the form of batteries. These energy storages harvest the sun power during daylight to support the household electrical demand after sunset. This paper linked the house roof design to the PV solar system for maximum generation condition. Furthermore the paper contains important information on the optimum location for the solar panel to ensure continuous and reliable system is achieved. An actual real case study is presented.
Performance Index: A Simple Selection Method of Appropriate Energy Storage for Specific Application
Authors: Ibrahim Hussein , Ghandour Mazen , Saad Sabine
Published: June 2018

The efficiency and cost of renewable power systems using intermittent resources could significantly be improved by developing low cost, high efficiency and more sustainable energy storage systems. There are various types of storage methods, some of which are already in use, while others are still in development. A comparison study between energy storage options is presented in this paper. We have taken a look at the main characteristics of the different electricity storage techniques and their field of application (permanent or portable, long-or short-term storage, maximum power required, etc.). These characteristics will serve to make comparisons in order to determine the most appropriate technique for each type of application. Based the results obtained in this study, a “performance index” have been determined for each storage technology in order to facilitate the comparison between the different storage devices.
Feasibility Study of Hybrid Wind-Diesel-Battery Power Generating Systems: Parametric and Sensitivity Analysis
Authors: Ibrahim Hussein , Ghandour Mazen , El-Jamal Georges
Published: June 2018

The renewables energies are being used to reduce the environmental pollution, combat the climate change and burning of fossil fuels. For remote or decentralized areas, where grid connection is very complex, renewable energy generation system can be a reliable and optimized source of energy. Moreover, wind-diesel-solar hybrid system technology promises lots of opportunities in remote areas which are far from the main grid and are supplied by diesel gensets. This paper is based on the analysis of a hybrid energy system for optimization. The analysis of the hybrid system is realized in the HOMER software package. The HOMER software was utilized as the assessment tool with modeling performed with hourly data of wind speed, solar radiation and load. In this study, the remote village of Tuktoyaktuk situated in Northwest Territories of Canada has been taken for the discussion of the optimization analysis of a hybrid energy generation system.
Optimization of Energy Management of a Microgrid Based on Solar-Diesel-Battery Hybrid System
Authors: Ibrahim Hussein , Ghandour Mazen
Published: June 2018

Hybrid systems, which are composed of combinations of diesel generators, battery energy storage system and renewable energy resources such as photovoltaic, are outlined as a recommended approach for off grid power supply options for remote areas applications. Since these systems are not connected to an infinite source of energy, they must be well designed and controlled to satisfy the demand load. This study presents an efficient battery management strategy for the charging and discharging of the batteries in a hybrid renewable energy systems by controlling the energy flow between different components of the system. In order to simulate the developed battery management strategy, the components of the hybrid system are studied and modeled using mathematical models. During modeling of the battery storage system, the effects of aging and capacity degradation were taken into consideration. The simulation of the strategy was based on a case study, where it is validated to be functional. Finally, the optimization of the strategy has been done by working on its critical parameters.
L’optimisation avec réduction de l’exposition du patient lors des procédures en scanographie TDM/TAP : cas des patients cancéreux au nord du Maroc
Authors: Bougana I. , Benabdelouahab F. , Loutfi A. , El Ouahrani A.
Published: June 2018

L’optimisation des procédures en scanographie TDM/TAP et la réduction des doses cumulées chez un patient cancéreux demeure une problématique majeure de la radioprotection médicale. Dans le but de mettre en lumière cette problématique, nous faisons recours à une étude rétrospective d’un échantillon homogène de 100 patients qui ont subi une TDM/TAP au service hospitalier de radiologie de la ville de Tétouan – nord du Maroc. Une évaluation dosimétrique des doses reçues par ces patients a été réalisée par PDL et les doses efficaces ont été calculées par la méthode de coefficient de conversion (Epdl). Les résultats montrent l’hétérogénéité dans les protocoles d’examens, l’absence d’un protocole TAP pour chaque catégorie d’âge, l’ignorance du paramètre poids des patients. L’objectif ultime est la mise en œuvre de protocoles TDM/TAP spécifiques respectant les catégories des patients cancéreux afin de réduire au maximum la dose délivrée et par conséquent de réduire le risque associé à cette exposition.
Teufelspsychose – Verlauf einer Psychotherapie in der
Forensischen Psychiatrie
Authors: Bartsch Benno
Published: June 2018

Hätte jemand die drastische Entwicklung der Psychoseerkrankung mit ihren
katastrophalen Folgen verhindern können? Trägt jemand die Verantwortung dafür?
Wie sicher sind Diagnose und aktuelle Prognose? Wann kann ein psychisch kranker
Straftäter entlassen werden und wer übernimmt dafür die Verantwortung? Mit Hilfe
der exemplarischen Skizzierung eines Krankheits- und Therapieverlaufs werden
Fragen gestreift, die typisch für die Forensische Psychiatrie sind.
Zur Psychologie des islamisierten Terrors
Authors: Kizilhan Jan Ilhan
Published: June 2018

Der islamisierte Terrorismus hat viele religiöse und ideologische Gesichter; er
nutzt moderne Medien, schafft transnationale Netze und zielt auf die Verbreitung
von Angst und Schrecken. Wie kommt es dazu, dass Tausende Menschen aus aller
Welt sich diesen Terrororganisationen anschließen und zu Massenmördern werden
und welche psychologischen, soziokulturellen, religiösen und politischen
Strukturen spielen bei der Motivation der Täter eine Rolle?
Wenn Psychotherapeuten schaden – Eine kollegiale
Reflexion
Authors: Achhammer Detlev , Krauss Gisela , Tibone Giulietta
Published: June 2018

Verstrickungen in der Psychotherapie – Therapeuten können in vielfältiger Weise
ihren Klienten schaden. Wie können psychotherapeutische Gesellschaften und
Institute mit Grenzverletzungen und ethischen Verstößen ihrer Mitglieder
umgehen? Die Autoren schildern die Erfahrungen der Deutschen Gesellschaft für
Psychoanalyse, Psychotherapie, Psychosomatik und Tiefenpsychologie (DGPT).
„Wer „Böses“ tut, ist nicht automatisch psychisch
krank“
Authors: Pollmächer Thomas
Published: June 2018

Prof. Thomas Pollmächer leitet die Task Force „Patientenautonomie“ der DGPPN. PiD
sprach mit ihm über Sichtweisen aus der Alltagspraxis
psychiatrisch-psychotherapeutischer Versorgung auf den Umgang mit Menschen, die
im Rahmen ihrer Erkrankung, Unerlaubtes tun. Es zeigt sich, dass Fragen zu
diesem Themenkomplex offenbar eine Fülle weiterer Fragen aufwerfen, die sich um
die Selbstbestimmung und Diskriminierung von Menschen mit psychischen
Erkrankungen ranken und erheblichen Diskussionsstoff bieten.
Untersuchung der Prävalenz kardiologischer Risikofaktoren in der Allgemeinbevölkerung: Ein Vergleich ambulanter ärztlicher Abrechnungsdaten mit Daten einer populationsbasierten Studie
Authors: Angelow Aniela , Reber Katrin Christiane , Schmidt Carsten Oliver , Baumeister Sebastian Edgar , Chenot Jean-Francois
Published: June 2018

Ziel der Studie Diese Studie untersucht die Validität ICD-kodierter Diagnosen für die kardiovaskulären Risikofaktoren arterielle Hypertonie, Diabetes mellitus, Dyslipidämie, Rauchen und Übergewicht aus kassenärztlichen Abrechnungsdaten in Bezug auf die Übereinstimmung mit klinischen Diagnosedaten einer populationsbasierten Kohortenstudie.

Methodik Hierzu wurden Abrechnungsdaten der Kassenärztlichen Vereinigung Mecklenburg-Vorpommern (Zeitraum 2008–2012) mit Daten der Study of Health in Pomerania (SHIP) gelinkt. Die Übereinstimmung der Abrechnungsdiagnosen (I10.- (arterielle Hypertonie), E10.- bis E14.- (Diabetes mellitus), E78.- (Dyslipidämie), F17.- (Zigarettenrauchen) und E65.- bis E68.- (Übergewicht oder Adipositas)) mit den erhobenen klinischen Goldstandarddaten von 1941 SHIP-Teilnehmern (46 % männlich, durchschnittliches Alter 58±SD 13 Jahre) wurde ermittelt.

Ergebnisse Von den untersuchten Abrechnungsdiagnosen lag für Diabetes mellitus (Sensitivität (Sens) 84%, Spezifität (Spez) 95%, Positiv Prädiktiver Wert (PPW) 80%) und arterielle Hypertonie (Sens 72%, Spez 93%, PPW 97%) eine höhere Übereinstimmung und für die Abrechnungsdiagnosen Zigarettenrauchen (Sens 18%, Spez 99%, PPW 89%), Übergewicht (Sens 22%, Spez 99%, PPW 99%) und Dyslipidämie (Sens 40%, Spez 60%, PPW 70%) eine geringe Übereinstimmung mit den klinischen Diagnosedaten vor. Bei vorliegendem Risikofaktor laut Goldstandard waren die Einnahme von Medikamenten, das Vorliegen weiterer dokumentierter kardiovaskulärer Risikofaktoren im Sinne von Komorbiditäten, Alter, Geschlecht und Erkrankungsschweregrad mit der Kodierung der Abrechnungsdiagnose assoziiert.

Schlussfolgerung Die Kodierqualität kardiovaskulärer Risikofaktoren im ambulanten Bereich variiert stark. Insgesamt besteht eine Unterkodierung, wobei abrechnungsrelevante Diagnosen besser kodiert werden. Basierend auf den Ergebnissen ist bevölkerungsbezogen eine Quantifizierung des Fehlers bei Prävalenzschätzungen auf Basis von Abrechnungsdaten für die untersuchten kardiovaskulären Risikofaktoren möglich.
Risikoberechnung mit Routinedaten? Entwicklung und Validierung multivariabler Modelle zur Prädiktion der 30- und 90-Tage-Mortalität nach chirurgischer Behandlung kolorektaler Karzinome
Authors: Crispin Alexander , Strahwald Brigitte , Cheney Catherine , Mansmann Ulrich
Published: June 2018

Ziele Qualitätssicherung, Benchmarking und Pay for Performance (P4P) erfordern aussagekräftige Indikatoren sowie die adäquate Berücksichtigung der Risikostruktur der Patientenpopulation der jeweiligen Institution anhand geeigneter statistischer Modelle. Der Ansatz, Abrechnungsdaten zur Qualitätsmessung und Risikomodellierung zu verwenden, wird häufig kritisch gesehen. Ziel unserer Analysen war die exemplarische Entwicklung von Prädiktionsmodellen für die 30- und 90-Tage-Mortalität nach chirurgischer Therapie kolorektaler Karzinome mit Routinedaten.

Studiendesign Vollerhebung der Patienten einer großen gesetzlichen Krankenkasse.

Setting Chirurgische Kliniken im gesamten Bundesgebiet.

Patienten 4283 bzw. 4124 Patienten mit Operationen kolorektaler Karzinome in den Jahren 2013 bzw. 2014.

Prädiktoren Alter, Geschlecht, Haupt- und Nebendiagnosen sowie Tumorlokalisation aus den von den Kliniken an die Krankenkasse übermittelten Abrechnungsdaten gemäß §301 Sozialgesetzbuch V.

Outcomes 30- und 90-Tage-Mortalität.

Statistische Analyse Ableitung von Elixhauser Comorbidities, Charlson Conditions sowie Charlson Scores aus den ICD-10-Diagnosen. Entwicklung von Prädiktionsmodellen anhand eines penalisierten Regressionverfahrens (logistische Ridge Regression) in einer Lernstichprobe (Patienten des Jahres 2013). Beurteilung von Kalibrierung und Diskriminationsfähigkeit der Modelle in einer internen Validierungsstichprobe (Patienten des Jahres 2014) mithilfe von Kalibrierungskurven, Brier Scores und Analysen von Receiver Operating Characteristic Curves (ROC-Kurven) und der Flächen unter denselben (Areas Under the Curves, AUC).

Ergebnisse Die 30- bzw. 90-Tage-Mortalität in der Lernstichprobe betrugen 5,7 bzw. 8,4%. Die entsprechenden Werte im Validierungssample waren 5,9% und gleichfalls 8,4%. Modelle auf der Basis der Elixhauser Comorbidities zeigten die beste Diskrimination mit AUC-Werten von 0,804 (95%-KI: 0,776–0,832) bzw. 0,805 (95%-KI: 0,782–0,828) für die 30- bzw. 90-Tage-Mortalität. Die zugehörigen Brier-Scores für die Elixhauser-Modelle betrugen 0,050 (95%-KI: 0,044–0,056) bzw. 0,067 (95%-KI: 0,060–0,074) und stimmten weitgehend mit denjenigen der konkurrierenden Modelle überein. Alle Modelle zeigten im Bereich niedriger prädizierter Wahrscheinlichkeiten eine gute Kalibrierung, bei höheren prädizierten Werten tendierten sie zur Überschätzung der Ereigniswahrscheinlichkeiten.

Schlussfolgerung Trotz der augenscheinlich befriedigenden Ergebnisse zur Diskriminierung und Kalibrierung der vorgestellten Prädiktionsmodelle auf der Basis von Abrechnungsdaten ist deren Anwendung im Kontext von P4P kritisch zu sehen. Als Alternative bietet sich die Modellierung auf der Basis klinischer Register an, die ein umfassenderes, valideres Bild vermitteln dürften.
4th International Consensus Conference on Advanced Breast Cancer (ABC4), Lisbon, November 4, 2017
Authors: Untch Michael , Würstlein Rachel , Marschner Norbert , Lüftner Diana , Augustin Doris , Briest Susanne , Ettl Johannes , Haidinger Renate , Müller Lothar , Müller Volkmar , Ruckhäberle Eugen , Harbeck Nadia , Thomssen Christoph
Published: June 2018

The fourth international advanced breast cancer consensus conference (ABC4) on the diagnosis and treatment of advanced breast cancer (ABC) headed by Professor Fatima Cardoso was once again held in Lisbon on November 2 – 4, 2017. To simplify matters, the abbreviation ABC will be used hereinafter in the text. In clinical practice, the abbreviation corresponds to metastatic breast cancer or locally far-advanced disease. This year the focus was on new developments in the treatment of ABC. Topics discussed included the importance of CDK4/6 inhibition in hormone receptor (HR)-positive ABC, the use of dual antibody blockade to treat HER2-positive ABC, PARP inhibition in triple-negative ABC and the potential therapeutic outcomes. Another major area discussed at the conference was BRCA-associated breast cancer, the treatment of cerebral metastasis, and individualized treatment decisions based on molecular testing (so-called precision medicine). As in previous years, close cooperation with representatives from patient organizations from around the world is an important aspect of the ABC conference. This cooperation was reinforced and expanded at the ABC4 conference. A global alliance was founded at the conclusion of the consensus conference, which aims to promote and coordinate the measures considered necessary by patient advocates worldwide. Because the panel of experts was composed of specialists from all over the world, it was inevitable that the ABC consensus also reflected country-specific features. As in previous years, a team of German breast cancer specialists who closely followed the consensus voting of the ABC panelists in Lisbon and intensively discussed the votes has therefore commented on the consensus in the context of the current German guidelines on the diagnosis and treatment of breast cancer 1, 2 used in clinical practice in Germany. The ABC consensus is based on the votes of the ABC panelists in Lisbon.
Mammography Screening 2.0 – How Can Risk-Adapted Screening be Implemented in Clinical Practice?
Authors: Fürst Nicole , Kiechle Marion , Strahwald Brigitte , Quante Anne
Published: June 2018

Introduction The mammography screening programme has been the subject of criticism for some time. Invitation to take part is currently based only on the risk factors of age and female sex, whereby women with an above-average risk are screened too seldom and women with a low risk are possibly screened too often. In future, an individualised risk assessment could make a risk-adapted procedure possible in breast cancer screening. In the RISIKOLOTSE.DE project, schemes are devised to calculate the individual breast cancer risk and evaluate the results. The aim is to assist doctors and screening participants in participatory decision-making. To gauge the baseline situation in the target groups, qualitative and quantitative surveys were conducted.

Method At the start of the project, a guideline-based focus group discussion was held with 15 doctors and representatives of the public health service. The transcript of this discussion was evaluated by means of a qualitative content analysis.

Results The participants assessed the concept of risk-adapted screening positively overall. At the same time, the majority of them were of the opinion that the results of individualised risk calculation can be understood and evaluated adequately only by doctors. The great communication requirement and lack of remuneration were given as practical obstacles to implementation.

Discussion The suggestions and new ideas from the focus group ranged from administrative and regulatory changes to new forms of counselling and adaptable practice aids. An important indicator for the RISIKOLOTSE.DE conception and for planning future surveys was that risk calculation for mammography screening 2.0 was regarded as a purely medical function and that the concept of participatory decision-making played hardly any part in the discussion.
Hypercoagulable States and Thrombophilias: Risks Relating to Recurrent Venous Thromboembolism
Authors: Rybstein Marissa , DeSancho Maria
Published: June 2018

Inherited and acquired thrombophilias and hypercoagulable states, such as active cancer, estrogen-induced, autoimmune disorders, major surgery, hospitalization, and trauma, are well-known risk factors for venous thromboembolism (VTE). The effect of these on recurrent VTE is different for each specific risk factor. The major risk factors affecting VTE recurrence include the presence of active cancer and an unprovoked first VTE. In addition, the use of combined female hormones in a woman with a previous history of estrogen-related VTE is a major risk factor for VTE recurrence. The extent of influence of inherited thrombophilia on the risk of recurrence is controversial. Conversely, the presence of antiphospholipid antibodies, specifically triple positive carriers, appears to increase the risk of VTE recurrence. Understanding the rates of recurrent VTE in a patient and the individual risk of bleeding is important in determining the duration of anticoagulation therapy.