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Copyright of Journal of Fuzhou University is the property of Journal of Fuzhou University, Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Screening is a key step in the process of non-ferrous metal beneficiation, and the screen plate is an important carrier for the screening process. The design of the material characteristics of the screen plate is an effective means to improve screening efficiency. However, in industrial production, due to technical limitations such as pouring technology and testing methods, this difficult to accurately design the material characteristics of the screening plate. Based on this, this study proposes a dynamic design method for elastic screen plate material characteristics based on DEM-FEM, and constructs a coupled simulation calculation model for screening of fine grained ilmenite particles using DEM-FEM. The design criteria are the impact stress and the material screening percentage of the screen plate under different screening plate material characteristics. The optimal combination of the elastic screen plate material parameters for 3 mm screening of ilmenite is determined through dynamic design: material constants C10 is 1.76 and C01 is 0.44, elastic modulus is 13.23 MPa, and density is 1.30 g/cm³. Finally, a solid new screen plate was assembled on the HEWA3060 screening machine for vibration characteristics testing and 3 mm industrial screening verification experiment. When the screening machine processing capacity was 12t/(h ⋅ m²), the screening efficiency reached 92.14. This study has important guiding significance for the design of key material characteristics of elastic screen plates. [ABSTRACT FROM AUTHOR]

Copyright of Guangdong Architecture Civil Engineering is the property of Guangdong Architecture Civil Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Applied Mechanics is the property of Chinese Journal of Applied Mechanics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The short flexspline harmonic drive has the advantages of a small axial size and a compact structure. However, unlike the ordinary cup-shaped flexspline with a long cylinder, a steel flexspline with a short cylinder often leads to concentrated stress and transmission failure due to inaccurate spatial meshing. This paper proposes a harmonic drive made of carbon fiber-reinforced polyetheretherketone (CF/PEEK) composite to solve this problem. The finite element method is employed to calculate and analyze the key technical performance of the composite material and the traditional steel harmonic drive. Results indicate the good vibration characteristics, fatigue life, and excellent load capacity of the new composite harmonic drive despite sacrificing some transmission accuracy. This work provides a new research method for designing a short flexspline harmonic drive using composite materials and a theoretical basis for designing a CF/PEEK short flexspline harmonic drive. [ABSTRACT FROM AUTHOR]

Industrial robots are complex systems, as they require the integration of several sub-assemblies to perform accurate operations. Moreover, they may experience remarkable dynamic actions due to high kinematic requirements, which are necessary to obtain reduced cycle times. The dynamic design of industrial robots can therefore be demanding, since the single structural component can induce an impact both in the design phase (development strategy and computational time) and at the machine level (global stiffness and natural frequencies). To this end, the present paper proposes first a topology optimization procedure based on the Equivalent Static Loads (ESL) method that integrates flexible multibody simulation outputs. The same procedure also foresees an intermediate static reduction to reduce and to precisely define the application points of the ESL. Secondly, an optimization procedure based on the Quasi-Static Loads (QSL) method integrating flexible multibody simulation outputs is proposed as well. The objective is to carry out a comparison between the two methods and consequently evaluate the benefits and drawbacks of the two. In the end, practical guidelines regarding the selection and application of the two methods are also provided to the reader. [ABSTRACT FROM AUTHOR]

The design and simulation methods of composite components are vital to the performance and application research of composite materials. Research pertaining to composite component design and simulation systems begins late in China and confronts many risks，including inadequate theoretical levels，lack of independent standards，weak foundation of simulation software，and segregation between design and manufacture. Therefore，the large-scale application of composite components in major equipment can hardly be realized. Considering the problems and challenges，this study analyzes the macro demand for composite component design theory and simulation technique，summarizes the development status and main trends in China and abroad，and proposes the key directions in China：design theory of composite components under extreme and multi-field environment，dynamic analysis and design theory of composite components，data-driven simulation method of composite components，and simulation evaluation method of strength and life of composite components. We suggest that research should be conducted on multi-field and multi-scale design technology of composite components for equipment engineering applications，performance design technology of composite components under dynamic load，data-driven design and simulation technology of composite components，and strength and lifespan simulation software platform of composite components，thereby comprehensively improving the design and engineering application level of composite components in China.

The absorbing transfer matrix method (ATMM) is applied to dynamics calculation and optimization design of planar branch piping systems combined with the response surface model or method (RSM) and a new proposed hybrid RSM (HRSM). A main path is chosen to absorb the influences of sub-branches, and the branch point transfer matrix in the main transfer path is established and proved by the ANSYS simulation and experimental results. It shows that the errors between the ATMM and the finite element method are less than 0.36% in the calculation of the natural frequencies of the two-branch piping system, and the ATMM also agrees well with the dynamics response experimental results of the cross-branch piping system. Then, based on the initial design model of a double-branch piping system, first order natural frequency analysis samples are selected for the branch point positions optimization using the uniform design method (UD) and calculated by the ATMM; the minimum value of the RSM, obtained by fitting the samples with a second-order polynomial (SOP) function, is solved as the best design scheme using the genetic algorithm (GA). Finally, for the problem of supporting positions optimization of a T-branch piping system, a HRSM using the SOP function to fit the variation law with different supporting positions in the samples of the dynamics response optimization target, which is the total x -directional vibration acceleration level (TAC) of three supporting points in the frequency 1–300 Hz and the Fourier basis function to fit the relationship of SOP function error with independent variables is proposed combining the Minimize Prediction (MP) adding point criterion to gradually update the samples, until the HRSM reaches stability and obtains the wanted design solution. [ABSTRACT FROM AUTHOR]

Layout variation is an essential concept in design and allows designers to create a sense of depth and complexity in their work. However, manually creating layout variations can be time-consuming and limit a designer's creativity. The use of generative art as a tool for creating visual poster designs that emphasize layout variety is explored in this study. Deep learning through generative art offers a solution by using an algorithm to generate layout variations automatically. This paper uses the VQGAN and CLIP approach to describe a generative art system, which renders images via a text prompt and produces a series of variations based on the zoom parameter 0.95 and shifts the y-axis 5 pixels. Our experiment shows that one frame can be generated roughly in 10.108 ± 0.226 seconds, significantly faster than the conventional method for creating layouts on poster design. The model achieved a good quality image, scoring 4.248 using an inception score evaluation. The layout variations can be used as a basis for poster design visuals, allowing designers to explore different visual representations of layouts. This paper demonstrates the potential of generative art to explore layout variation in visual design, offering designers a new approach to creating dynamic and engaging visual designs. [ABSTRACT FROM AUTHOR]

Industrial robots are complex systems, as they require the integration of several sub-assemblies to perform accurate operations. Moreover, they may experience remarkable dynamic actions due to high kinematic requirements, which are necessary to obtain reduced cycle times. The dynamic design of industrial robots can therefore be demanding, since the single structural component can induce an impact both in the design phase (development strategy and computational time) and at the machine level (global stiffness and natural frequencies). To this end, the present paper proposes first a topology optimization procedure based on the Equivalent Static Loads (ESL) method that integrates flexible multibody simulation outputs. The same procedure also foresees an intermediate static reduction to reduce and to precisely define the application points of the ESL. Secondly, an optimization procedure based on the Quasi-Static Loads (QSL) method integrating flexible multibody simulation outputs is proposed as well. The objective is to carry out a comparison between the two methods and consequently evaluate the benefits and drawbacks of the two. In the end, practical guidelines regarding the selection and application of the two methods are also provided to the reader.

The design of Reconfigurable Control Systems (RCS) is a tremendous task since that their increasing need for reconfiguration imposes the anticipation of all potential runtime changes at design time, which is in most cases infeasible. To deal with the high dynamicity of RCS at design-time we propose a novel design approach, RLReC (R einforcement L earning-based Re configuration C ontrol) allowing for the improvement of reconfiguration knowledge through online (runtime) exploration. This approach combines the benefits of meta-modelling with Reinforcement Learning (RL) principals for reconfiguration knowledge modelling in order to handle early and effective exploration of various design choices. In this work, the reconfiguration controller is an autonomous software agent designed as a RL agent (RLRA) that handles both offline (exploitation) and online (exploration) learning through interactions with the controlled system at runtime. In particular, the RLRA has to select reconfiguration rules that were not selected before, which is known as exploration. The main aim of this proposal is to cope with design-time unplanned changes by giving the RLRA the ability of improving its knowledge through online learning feedback. We illustrate the use of our contributions with a running example from the manufacturing domain. [ABSTRACT FROM AUTHOR]

Sleeper spacing has been a taboo subject throughout the railway's history. Safety concerns related to the structural integrity have been the main causes of not addressing this matter. There are no specific and clear recommendations or guidelines in relation to this matter and the distances do not go more than 0.8 m. In order to go beyond this current situation, the following research paper analyses the influence of the spacing between sleepers on the behaviour of ballasted tracks by performing a dynamic simulation with finite elements in two dimensions for different track configurations, different elements, geometries, and separations within the frame of the ODSTRACK project. The variables studied are the vertical displacements, the forces and stresses on the most important elements of the superstructure, as well as the vertical accelerations in the sleepers and the train. The values obtained from the numerical simulations were compared with the maximum permitted values according to the guidelines. To limit this distance to the most restrictive variable among those analysed, it is necessary to make important assumptions, such as the permissible values and effective support contact areas between the sleepers and the ballast. The preliminary analyses carried out shed light on a possible increment of the spacing between sleepers' axes up to more than 0.8 m. This suggests that important savings in railways construction costs can be achieved, and they will help to develop the next stage of the ODSTRACK project. [ABSTRACT FROM AUTHOR]

• Two dynamic and cyclic concepts are proposed to relieve scaling at ultra-high recoveries. • Pumps and valves are added to dynamically direct flows in multistage ROs. • System designs are conducted following FilmTec's guidelines. • FRRR and SRRO avoid cycle-to-cycle salt buildup in CCRO. • Increasing recovery from 80% to 90% demands a slight increase in energy consumption. There is a drive for ultra-high recoveries in waste and brackish water RO desalination due to high brine disposal costs. In this work, two novel dynamic and cyclic designs (i.e. feed reversal and retentate recycle with a time-varying ratio in stage 3, as well as stage rotation between 1 and 3) are proposed to achieve a 90% recovery while alleviating scaling potential. The designs are conducted following FilmTec's guidelines and are simulated using validated models published previously. It is shown that retentate recycle suppresses concentration polarization, despite a higher pressure drop. Feed reversal leads to a quick drop of salt concentration due to mixing of fresh feed and brine. However, if the feed reversal is applied to the same stage, the salt concentration on the other end may be higher than brine concentration for a short period of time. Such a behavior is not observed during rotations between stages 1 and 3, whether the feed is reversed or not. Interestingly, the designs at 90% recovery demand only a few percent more energy than traditional two-stage designs operated at 80% recovery. Moreover, cycle-to-cycle salt build-up in batch-type ROs is absent in both dynamic designs presented in this work. [ABSTRACT FROM AUTHOR]

Copyright of Railway Standard Design is the property of Railway Standard Design Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The assessment of the time evolution of the impact force exerted by dry flowing masses on rigid obstacles is mandatory for the dynamic design of sheltering structures and the evaluation of the vulnerability of existing structures. In this paper, the results of an extensive numerical campaign performed by employing a discrete element method (DEM) code are presented and the role of different geometrical factors (flow length, height and front inclination) and state parameters (porosity and velocity) on the impact force–time evolution is investigated. The impact process is studied to correlate local information with the macroscopic response and a physically based force–time function, generalising the formula already introduced by the authors for the assessment of maximum impact force, in which each parameter is correlated with the previously mentioned factors, is proposed. [ABSTRACT FROM AUTHOR]

Featured Application: The proposed time-domain dynamic modeling method can be applied to analysis and design of heavy-duty gearboxes in wind turbines, cranes, drilling rigs and so on. Expert insights into the time-domain dynamic behavior of heavy-duty gearboxes form the foundations of design evaluation and improvement. However, in the existing lateral–torsional coupling (LTC) modeling method for gearboxes that is normally used for frequency-domain dynamic behavior, the meshing forces are modeled as spring dampers with fixed acting points on the meshing gears to simulate only the transient LTC effect, and thus the steady state characteristic in the time domain cannot be obtained due to the unrealistic distortion of positions and orientations as the gear angles increase. In this paper, a novel and generally applicable LTC modeling method for heavy-duty gearboxes, mainly planetary gear sets with floating components, is proposed by using space-fixed spring dampers with floating acting points on the meshing gears to study the time-domain dynamic response and to support the dynamic design of heavy-duty gearboxes. Based on the proposed method, a LTC model of a 2 megawatt (MW) wind turbine gearbox with floating components considering the time-varying meshing stiffness, bearing stiffness, torsional stiffness, and floating effect was established. The simulated results of representative components were in accordance with experimental results on a test rig, and dynamic behavior was calculated. [ABSTRACT FROM AUTHOR]

Heavy, large and robust supporting structures are needed to keep the airgap clearance of direct-drive multi-MW wind turbine electrical generators open and stable. As rotating pieces of machinery, generators vibrate when their natural frequencies are excited introducing potentially large amplitude oscillations due to the forces acting on them that could cause structural fatigue, noise and, in the worst-case scenario, their sudden collapse. A novel procedure for cost-effective and dynamically efficient structural design of a generator has been developed through a series of different finite element studies for a proposed 3MW machine with a conical rotor structure working under extreme conditions. Following a parametric approach coupled with the use of a topology optimisation tool it was demonstrated that the structural mass and dynamic response of the machine can be minimised, while complying with the deflection requirements. [ABSTRACT FROM AUTHOR]

Sleeper spacing has been a taboo subject throughout the railway’s history. Safety concerns related to the structural integrity have been the main causes of not addressing this matter. There are no specific and clear recommendations or guidelines in relation to this matter and the distances do not go more than 0.8 m. In order to go beyond this current situation, the following research paper analyses the influence of the spacing between sleepers on the behaviour of ballasted tracks by performing a dynamic simulation with finite elements in two dimensions for different track configurations, different elements, geometries, and separations within the frame of the ODSTRACK project. The variables studied are the vertical displacements, the forces and stresses on the most important elements of the superstructure, as well as the vertical accelerations in the sleepers and the train. The values obtained from the numerical simulations were compared with the maximum permitted values according to the guidelines. To limit this distance to the most restrictive variable among those analysed, it is necessary to make important assumptions, such as the permissible values and effective support contact areas between the sleepers and the ballast. The preliminary analyses carried out shed light on a possible increment of the spacing between sleepers’ axes up to more than 0.8 m. This suggests that important savings in railways construction costs can be achieved, and they will help to develop the next stage of the ODSTRACK project.

In modern warfare, in order to destroy the target to largest extent, missile warhead is required to explode after penetrating inside the target, therefore, the measurement of mechanical signal during projectile penetration is critical. This paper studies the dynamic design principle of projectile penetration overload test system based on charge sensor, according to characteristics of steep front and a great number of contained installing structure impulse response, designs the measuring circuit based on charge sensor, conducts detailed theoretical deduction on dynamic model of sensor, charge-amplifier, filter and single conversion differential circuit, and provides theoretical basis for design. In order to more objectively evaluate the dynamic characteristics of this kind of test system, the dynamic uncertainty estimation of charge signal measured by this test system is considered as the standard for evaluating its dynamic characteristics, instead of unflatness of amplitude-frequency characteristic and its width in frequency domain, and the comprehensive evaluation on uncertainty of this test system is realized. In order to improve the measurement accuracy of dynamic test system designed, in this paper, an improved de-noising algorithm based on Ensemble Empirical Mode Decomposition (EEMD) is proposed, different low-pass filters are formed on the basis of Intrinsic Mode Function (IMF), de-noising effect of signal with noise is analyzed, and the evaluation indicators of dynamic uncertainty and approximation are established. Finally, the effectiveness of the designed method is verified through experiment.

The most significant challenge facing the researcher in the field of robotics is to control the robot manipulator with appropriate overall performance. This paper focuses mainly on the novel Intelligent Particle Swarm Optimization (PSO) algorithm that was used for optimizing and tuning the gain of conventional Proportional Integral Derivative (PID), and improve the parameters of dynamic design in Sliding Mode Control (SMC), which is considered a strong nonlinear controller for controlling highly nonlinear systems, particularly for multi-degree serial link robot manipulator. Additional modified Integral Sliding Mode Controller (ISMC) was implemented to the design of dynamic system with high control theory of sliding mode controller. Intelligent Particle Swarm Optimization (PSO) algorithm was introduced for developing the nonlinear controller. The algorithm demonstrates superior performance in determining the appropriate gains and parameters value in harmony with robot scheme dynamic layout in order to achieve suitable and stable nonlinear controller, besides reduce the chattering phenomenon. PUMA robot manipulator that was used as study case in this work, shows perfect result in step response, with acceptable steady state, and overshoot, besides, eliminating the disadvantage of chattering in conventional SMC. Matlab / Simulink presents to increase the speed of matrix calculation in forward, inverse kinematics and dynamic model of manipulator. Comparison was made between the proposed method with existing methods. Result shows that integral sliding mode with PSO (ISMC/PSO) gave best result for stable step response, minimum mean square error with best objective function, and stable torque. [ABSTRACT FROM AUTHOR]

Literature has suggested numerous benefits of online learning. In this study, we focused on asynchronous online discussion in higher education. We defined effective online discussions as making social presence known and conducting multidimensional discussions. Three dimensions were used to define multidimensional discussions: time, learning space, and example. Discussion posts and course evaluations made by graduate students in two online courses were examined to understand whether different sizes of online discussion groups and requirements for discussions can generate different frequencies of social presence and multidimensional discussions. Results showed that when the class size was around 30, whole class interaction in online discussions and requiring students to reply to others' posts encouraged students to make their social presence known and to conduct multidimensional discussions. Furthermore, when students were assigned to small groups of three or four students for online discussions, the frequencies of social presence and multidimensional discussions depended on other group members' engagement in discussions. Findings from the study also provided evidence that making one's social presence known was positively related to multidimensional discussions. Implications of the findings are discussed. [ABSTRACT FROM AUTHOR]

Known as one of the significant sources of impacting building energy efficiency, climate change can drastically alter the long-term energy consumption patterns of buildings. It is widely acknowledged in the literature that designs based on conventional pathways relying solely on historical weather data disregard the effects of the changing climate and lose their intended energy performance over time. Several endeavors have been made to generate weather files capable of capturing the essence of the changing climate and carrying its variability. In line with these efforts, the synthesized weather files have emerged as a promising alternative to the commonly used morphing method for incorporating climate change variability into building energy designs. However, a comprehensive framework with a potential to accommodate this variability in this context is yet to be investigated. Addressing this gap, the present study aims to propose a novel framework that can facilitate dynamic design upgrades in response to the changing climate including the extreme climate conditions. This framework has been applied to a case study building in Australia and around 31% annual thermal load reduction, on average, has been achieved. Furthermore, the results showed that conventional design pathways are likely to leave buildings inadequately prepared against the upcoming climate conditions. Therefore, the proposed framework is capable of generating a dynamic design that not only maintains the expected energy performance by incorporating the changing climate into its structure but also draws a more realistic picture of the building energy demand pattern over time. • Conventional building designs neglecting climate change, lead to energy deficiency. • Extreme climate conditions can noticeably affect thermal energy demand. • CABED reduces thermal load by 20% on average, even facing extreme climate conditions. • CABED retains the initial energy rating stars over time, unlike the static design. [ABSTRACT FROM AUTHOR]

Expert insights into the time-domain dynamic behavior of heavy-duty gearboxes form the foundations of design evaluation and improvement. However, in the existing lateral–torsional coupling (LTC) modeling method for gearboxes that is normally used for frequency-domain dynamic behavior, the meshing forces are modeled as spring dampers with fixed acting points on the meshing gears to simulate only the transient LTC effect, and thus the steady state characteristic in the time domain cannot be obtained due to the unrealistic distortion of positions and orientations as the gear angles increase. In this paper, a novel and generally applicable LTC modeling method for heavy-duty gearboxes, mainly planetary gear sets with floating components, is proposed by using space-fixed spring dampers with floating acting points on the meshing gears to study the time-domain dynamic response and to support the dynamic design of heavy-duty gearboxes. Based on the proposed method, a LTC model of a 2 megawatt (MW) wind turbine gearbox with floating components considering the time-varying meshing stiffness, bearing stiffness, torsional stiffness, and floating effect was established. The simulated results of representative components were in accordance with experimental results on a test rig, and dynamic behavior was calculated.

Educators have been using social media to enrich learning activities and promote interactive and collaborative learning. Under the context of dynamic learning - the way that 21st century's learners learn, the new challenges are: how educators design such a setting to effectively integrate certain social media tools to improve learning, and what the influential factors might be that educators need to focus during the design. In this article, we employ the concept "logistics" to explain and redefine dynamic design, dynamic learning, and dynamic thinking, which furthermore formulate the framework of the study. This article presents a critical content review of current literature, and an analysis of 276 cases located from the literature on seven factors (Information Logistics, Technology Logistics, Overall Design Logistics, Collaborative Learning, Active Stimulation, Motivation, and Objective-Driven Activities) regarding their influence on the success of social medial supported learning experiences. All seven factors were found to be significant and included in a static predictive model. An in-depth comprehension of this static predictive model is provided, based on which a new dynamic model is proposed. [ABSTRACT FROM AUTHOR]

Direct-drive permanent magnet generators for multi-MW wind turbines are low speed high torque electrical machines requiring large, heavy and robust structures to maintain the airgap clearance open and stable. The structural mass of radial-flux generators can be estimated at an early phase of the design process. Using distinct approaches, the integrity of a 3 MW electrical machine structure has been addressed from a dynamic perspective by carrying out modal analyses with a view to minimize its mass. A versatile tool has also been developed to help the engineers with the dynamic design of generator disc structures. Conical structures have been analysed and compared with the baseline disc model obtaining very promising results. Potential improvements have been proposed for more ambitious structural designs. [ABSTRACT FROM AUTHOR]

Constructed wetlands treating combined sewer overflow (CSO CWs) are vertical flow filters in France, with outflow limitation and detention basin. Treating storm-generated flows reduces pollutants and flow peaks entering natural waters. Storm-generated flows are stochastic and therefore optimized CSO CW design requires a dynamic approach, i.e., a modelling software targeting engineers. Therefore a new tool, called Orage, was developed. Orage consists of a core model, an iterative shell and a user interface. It optimizes dimensions and materials of CSO CWs site-specifically, based on inflow series and a low number of input parameters. The core model simulates hydraulics and TSS, COD and NH 4 -N removal. Manual fitting of the core showed good results with a single load. The same parameters gave satisfying accuracy when simulating load series with closed material balance. Sensitivity analysis confirmed model robustness and justified coupling with an automatic shell algorithm for automatic optimization, based on a single output. [ABSTRACT FROM AUTHOR]

A new approach has been developed to determine the dynamic amplification factors of railways. This approach employs a traditional multi-body dynamic model of vehicle--track interaction and a 3D explicit finite element model of wheel--rail rolling contact to treat the low- and high-frequency dynamics, respectively. Excitations are considered by contact surface unevenness and more specifically, by the power spectrum density of track irregularity for the low-frequency analysis and by the critical wheel flat, weld, and rail corrugation for the high frequency. For the 40-tonne axle load heavy haul railway simulated in this work, it has been found that the optimum fastening stiffness should be 150-200 MN/m; the dynamic amplification factors of the wheel--rail contact, fastening, and ballast forces are 1.94, 2.0, and 1.67, respectively, if the fastening stiffness of 200 MN/m is applied. Finally, new dynamic amplification factor formulae that include key parameters such as the fastening stiffness, speed, and axle load are proposed for the heavy haul railway design. [ABSTRACT FROM AUTHOR]

The qualities of perishable products are significantly influenced by the environment during the circulation process, and environmental factors have a crucial effect on the decay of perishable products. Timely risk control can ensure the safety of perishable products when environmental information in circulation is completely collected. In order to comprehensively collect the environmental information of the perishable products in the supply chain, this study presented a method that extracted the cold chain information according to the independent category and constructs to establish the information dynamic record data collection method and the information integration framework model. Based on the information that could be independently extracted from the cold chain, this study proposed that the data collection of dynamic recording should be conducted and the module framework of information integration should be constructed. By designing and planning the individual module of cold-chain circulation information of perishable products, dynamic data collection and information integration framework were shaped to classify and stratify the key information, and aquatic products in the cold chain were taken as an example to verify the effectiveness and accuracy of the module. Results indicate that 89% of the integrated processing of environmental information can be achieved through the independent module processing of perishable products and dynamic management of information stratification. Meanwhile, information modularization, rate of stratification coverage, and accurate estimation of the shelf life of perishable products exhibit a positive correlation. To some extent, the proposed method provides references for the coldchain risk management and accurate estimation of the shelf life of perishable products. [ABSTRACT FROM AUTHOR]

Design and execution of a trough excavation pit in the Hamburg city center considering complex structural conditions For the project Alter Wall in Hamburg the creation of highly valued office buildings and retail stores is being realized in the heart of the city center. In cooperation with the BID Nikolai Quarters (Business-Improvement-District) the Alte Wall is being reshaped in a high-quality internal-urban boulevard. In close vicinity of the city hall in Hamburg, existing buildings are being demolished up to the street-sided façade and an underground parking with five basements is being established. In this area very inhomogenous geologic conditions exist, comprising of backfill, organic soft layers as well as alternating sequences of sand, marl and clay. On basis of the results of the ground investigation carried out, the excavation was designed as a trough excavation pit. A diaphragm wall with depths between 43 and 50 m was constructed into the underlain impervious layers. The cross bracing of the excavation pit existed of two layers. Because of the existing difference of the ground levels of approximately 7 m between the Alte Wall and the shipping canal, additional soil-anchors have been installed. Before the demolition of the existing building began, the execution of soil investigations in the construction area was not possible. The site investigations carried out after demolition of the buildings have proved, that in one area a supposed deep glacial sandy channel exists, so that the diaphragm wall could not be embedded in the impervious layer, because this is located in a depth of approx. 70 m beneath the surface. Therefore, a grout injection veil consisting of soft gel reaching form the lower edge of the diaphragm wall into the impervious layer was realized. On basis of the won knowledge during construction, the design had to be updated and put in place immediately during construction. The development and the dynamic updating of the excavation pit planning, the results of the deformation and groundwater level measurements, the assurance of the acceptable deformation of the historical buildings as well as the braced façade and the effectiveness of the timber pile foundation of the city hall is being explained. [ABSTRACT FROM AUTHOR]

Optimal design and rehabilitation scheduling of water distribution networks (WDNs) have been often dealt separately over the past few decades. However initial design (which is named as static design in this paper) has indubitable influence on the operational condition and rehabilitation scheduling of network. This paper introduces an approach for simultaneous optimization of initial design and rehabilitation scheduling of WDNs during their life cycle. In this approach which is named as dynamic design, pipe diameters in the first year and their rehabilitation/replacement in the next years of the expected life of the network are determined considering the nodal demands growth and increase in pipes' roughness. The proposed model consists of a multiobjective ant colony optimization engine linked to a pressure dependent analysis model and a pipe break prediction model. This paper introduces the following contributions: (1) it implements dynamic design based on the pressure dependent analysis with considering leakage; (2) a support vector machine based sub model is used for pipe break prediction. Then pipe breaks and their repair costs are considered in dynamic design process; (3) a new reliability index is used as one of the objective functions. Two networks are used to investigate the impact of static and dynamic designs on the reliability and total cost of design and rehabilitation of WDNs during their life cycle. The results show that the dynamic design produces more reliable and lower cost networks in comparison to the ones resulted from either static design or rehabilitation scheduling separately. [ABSTRACT FROM AUTHOR]

Post-combustion capture is a promising solution to mitigate the anthropogenic CO 2 emission rate and reduce global warming. However, to make it economically attractive, the techno-economic performance of this process needs to be improved. This includes steady-state but also dynamic operation of the plant. Flexibility is particularly crucial from an economic and operational point of view since plants must balance the power production and the electricity demand on a daily basis. This work shows the impact of design decisions and uncertainties on the dynamic operation and economics of a CO 2 capture plant using piperazine (PZ), compared to the benchmark MEA solvent. This is exemplified through dynamic model calculations. The results show that the capacity of the buffer tank is a key parameter for the flexibility of the plant. A small tank corresponds to lower capital cost but it leads to increased operation cost and also to flexibility/controllability issues. Both, the PZ and MEA plants present inverse response for small tanks. These plants are challenging to control. [ABSTRACT FROM AUTHOR]

The model-based Orage toolkit facilitates the design of constructed wetlands treating combined sewer overflow (CSO-CWs). It deals with the stochasticity of overflows and optimizes filter area and material site-specifically. Its automatic optimization approach, which is based on measured or simulated CSO series and simple input parameters, is a novelty. In the process, the iterative shell calls a single-output model repetitively, comparing effluent concentrations from different filter setups to legislative thresholds. The approach was confirmed with measured and simulated inflows. Parameters were fixed so that extremely small and large filters are avoided (decreases clogging risk and short-circuiting, respectively), and pollutant removal is optimized on a tighter range of filter areas. The iterative shell was verified using inflow data and area of a full-scale CSO-CW, with effluent thresholds between 4–10 mg/L NH 4 -N. Zeolite-enriched media ensures NH 4 -N removal at high hydraulic loads (possibly up to 250 m 3 /m 2 /year) where clogging is a possible risk. [ABSTRACT FROM AUTHOR]