Hemming process with counteraction force to prevent creepage

Creepage, a typical phenomenon in the hemming process, can be defined as undesired roll-in of the panel at the bending line. Creepage also reduces the final panel width and makes the hemming radius larger. In this study, experimental observations are reported, and a finite element model, based on the LS-DYNA^® two dimensional plane strain solid formulation, is utilized to study the mechanics of how the hem flange bends and folds during the hemming process. A novel hemming process incorporating a counteraction force is proposed in order to prevent the creepage phenomenon during the hemming process. An experimental hemming tool was designed according to this concept, and optimization of the tooling geometry was carried out utilizing the finite element model. An experimental study was conducted to confirm that the new hemming process can prevent creep be employed to help retain a sharp radius during flanging operation.     

Numerical Analysis and Optimization of Hemming Processes

Prediction and minimization of hemming defects are critical to the final quality of automobile products. In this paper, finite element analysis (FEA) is employed to simulate flat surface-straight edge hemming operations. Numerical simulations are conducted on the most representative points selected using a computer experiment design method, which involves orthogonal Latin hypercube sampling and response model building. A novel approach of selecting combined parameters as input factors from engineering analysis is proposed. The response surface models (predictors) obtained can capture the fundamental mechanism of the hemming process. The optimization method is developed based on the predictors instead of on time-consuming FEA simulations.     

The design of blanket wash solvents with environmental considerations

The search for new solvents is often driven by (a) the need to replace solvents whose continued use pose a threat to environmental health and safety, (b) the needs of new applications and processing requirements, (c) a response to changing environmental regulations and (d) a response to market demands. For example, many traditional solvents are on the environmental ‘hit list’ and are to be phased out within the next few years. In particular, cleaning solvents, which are used as blanket washes in the lithographic printing industry present a number of environmental concerns including health and safety. To respond to these concerns and more importantly to respond to rapidly changing operational requirements and market forces, there is a need for efficient and systematic strategies for ‘just in time’ optimal design of solvent alternatives. A good strategy has to consider simultaneously, performance objectives, system interactions and environmental constraints. The object of this paper is to identify and discuss the issues in the design of cleaning solvents (blanket washes) in the printing industry and how environmental and health factors can be accounted for. We do this in the context of a framework for product design. As a proof-of-concept, blanket wash solvents are designed.     

Hydrocarbons from plants: Analytical methods and observations

We have suggested that certain plants rich in hydrocarbon-like materials might be cultivated for renewable photosynthetic products. Two species were selected for experimental plantations: Euphorbia lathyris, an annual from seed and Euphorbia tirucalli, a perennial from cuttings. The yield from each species is over 10 barrels of oil/acre/year without genetic or agronomic improvement. In addition to plants, there are trees, such as species of Copaifera in Brazil and other tropical areas, which produce a diesel-like oil upon tapping. Each tree produces approximately 40 liters of hydrocarbon per year, and this material can be used directly by a diesel-powered car. Further efforts to develop plants as alternate energy sources are underway, as well as a continuing search for additional plant species throughout the world which have a similar capability.     

The mechanism of different cyanobacterial responses to glyphosate

Glyphosate, the most extensively used herbicide globally, has raised ecotoxicological concerns because it can be transported into the aquatic environment and cause adverse effects on the aquatic system. However, the functional mechanism of glyphosate on cyanobacteria are not completely disentangled. In this study, we selected six common cyanobacteria to evaluate glyphosate effects on cyanobacterial growth in monoculture experiment. Results showed that the growth of five tested cyanobacterial species were promoted under different degrees, and only Pseudanabaena was inhibited by glyphosate. In the phylogenetic tree based on gene sequences of 5-enol-pyruvylshikimate-3-phosphate synthase (EPSPS), a target for glyphosate, we found that the position of Pseudanabaena is the closest to plant, which was sensitive to glyphosate, thereby explaining the inhibitory effect of Pseudanabaena following glyphosate exposure. The primary degraded metabolites or analogs did not induce cyanobacterial growth, laterally demonstrating that glyphosate was used as a source of phosphorus to accelerate cyanobacterial growth because phosphorus levels increased in the medium of glyphosate treatment. Overall, this study provides a better understanding of the influence of glyphosate on the composition of aquatic microbiota and explains the mechanism of cyanobacterial response to glyphosate.     

Renaturing cities using a regionally-focused biodiversity-led multifunctional benefits approach to urban green infrastructure

If a ‘Renaturing of Cities’ strategy is to maximise the ecosystem service provision of urban green infrastructure (UGI), then detailed consideration of a habitat services, biodiversity-led approach and multifunctionality are necessary rather than relying on the assumed benefits of UGI per se. The paper presents preliminary data from three case studies, two in England and one in Germany, that explore how multifunctionality can be achieved, the stakeholders required, the usefulness of an experimental approach for demonstrating transformation, and how this can be fed back into policy. We argue that incorporating locally contextualised biodiversity-led UGI design into the planning and policy spheres contributes to the functioning and resilience of the city and provides the adaptability to respond to locally contextualised challenges, such as overheating, flooding, air pollution, health and wellbeing as well as biodiversity loss. Framing our research to encompass both the science of biodiversity-led UGI and co-developing methods for incorporating a strategic approach to implementation of biodiversity-led UGI by planners and developers addresses a gap in current knowledge and begins to address barriers to UGI implementation. By combining scientific with policy learning and defined urban environmental targets with community needs, our research to date has begun to demonstrate how nature-based solutions to building resilience and adaptive governance can be strategically incorporated within cities through UGI.     

‘Polishing the Kaswentha’: a Haudenosaunee view of environmental cooperation

Increasingly, Native American and non-Native governments, institutions and individuals are searching for cooperative ways to address environmental problems. While such approaches can offer substantial benefits over top-down or unilateral efforts, there are also potential pitfalls, especially when considering the needs and interests of the Native parties. Among these are threats to their status as sovereign nations, and to their political, economic and cultural autonomy. Given such concerns, many Indian Nations are seeking models for collaboration which protect their unique status based on indigenous and treaty rights, while respecting their cultural identity, values, and indigenous knowledge. In this paper we explore how one Native group in particular, a coalition of Haudenosaunee Nations in the US and Canada, has dealt with these complex issues. We show how positive relationships with outside agencies and researchers have been made possible through the use of mechanisms and processes based on traditional Haudenosaunee concepts and values. Finally, we explore how one item in particular, a 17th century treaty belt called the Kaswentha, offers a powerful symbol for forming relationships which respect Haudenosaunee autonomy while allowing collaborative partnerships to address critical environmental concerns.     

A simple sequential approach for designing industrial wastewater treatment networks

This paper addresses design of wastewater treatment network (WWTN) by hybrid approach. This is a sequential method applying insight-based techniques followed by mathematical programming. The water pinch analysis and wastewater degradation concepts are employed to develop an initial structure. Based on this solution a superstructure is created. The superstructure is the starting point for nonlinear optimisation. The decision variables are both structure of junctions (mixers and splitters) and flow rates. The optimisation model is solved by a simple but robust optimisation algorithm. The design approach can be used for synthesis and also, under some conditions, for retrofit of wastewater treatment networks. The efficiency and robustness of the approach is illustrated using literature examples and industrial cases.     

Energy based phenomenological model for optimizing the sheared edge in the trimming of steels

Attributes related to the dimensional quality of hot rolled steels are very important in commercial sectors that make direct use of this product, because delay or equipment damage can be avoided when forming in downstream operations. In this research, the steel sheet edge trimming process and its relationship with the defect known as broken edge is experimental and numerically studied. The type of material, horizontal clearance between knives and the energy spent during the cutting process are analyzed in detail. A metal-mechanical study is carried out for obtaining a microstructural hardness and flow stress characterization. Consequently, the edge trimming process is FEM simulated and its results in relation to knife penetration and shear stress lead to determining the energy spent during the cutting process. A mathematical model is determined under the consideration that minimum energy gives the optimum cutting conditions. The model proposes a reliable value for the horizontal clearance (H_c), between knives, taking as the principal factors: energy consumed during the edge trimming process, sheet thickness (T_h), carbon content (C) and/or its ultimate tensile strength, expressed as: H_c = α + βT_h − γC. A comparison of the recommended numerical results with the best practical conditions is carried out and a high coincidence is successfully found. This model is expected to be easily adopted as a tool where operators can adjust and control the parameters of process, and then, as a result, produce a sheet without edge trimming defects as well as a reduction in efficiency costs.     

Tetrabromobisphenol A (TBBPA): A controversial environmental pollutant

Tetrabromobisphenol A (TBBPA) is one of the most widely used brominated flame retardants and is extensively used in electronic equipment, furniture, plastics, and textiles. It is frequently detected in water, soil, air, and organisms, including humans, and has raised concerns in the scientific community regarding its potential adverse health effects. Human exposure to TBBPA is mainly via diet, respiration, and skin contact. Various in vivo and in vitro studies based on animal and cell models have demonstrated that TBBPA can induce multifaceted effects in cells and animals, and potentially exert hepatic, renal, neural, cardiac, and reproductive toxicities. Nevertheless, other reports have claimed that TBBPA might be a safe chemical. In this review, we re-evaluated most of the published TBBPA toxicological assessments with the goal of reaching a conclusion about its potential toxicity. We concluded that, although low TBBPA exposure levels and rapid metabolism in humans may signify that TBBPA is a safe chemical for the general population, particular attention should be paid to the potential effects of TBBPA on early developmental stages.     

Organic peroxy radicals: Kinetics,spectroscopy and tropospheric chemistry

The present state of knowledge of organic, or carbon-based, peroxy radicals (RO₂) is reviewed. Data on the chemical and physical properties of peroxy radicals in the gas-phase is considered, as well as the role of peroxy radicals in tropospheric chemistry and measurements of their concentrations in the atmosphere. Where appropriate, peroxy radicals are grouped together by type (alkyl, acyl, oxygen-substituted, halogen-substituted and aromatic radicals) to facilitate comparison. Data on the hydroperoxy radical (HO₂) is included where it is directly relevant to measurements on organic peroxy radicals, eg. absorption cross-sections used in measurements of RO₂ + HO₂ rate constants. The literature data is critically reviewed and recommendations for absorption cross-sections, rate constants and branching ratios are made where considered appropriate.The laboratory experimental techniques which have been used for the generation and detection of peroxy radicals and the products of their reactions are discussed. The structure, spectroscopy and thermochemistry of the radicals are examined. Although the majority of spectroscopic data concerns the u.v. spectra much used for kinetic studies, near-infrared, infrared and electron spin resonance spectra are also considered. In many cases, peroxy radical u.v. spectra are well-fitted by a Gaussian distribution function, enabling the cross-sections to be easily calculated at any wavelength.For the purpose of this review, the chemical reactions of peroxy radicals are divided into reactions with organic peroxy radicals with HO₂, with NO and NO₂, and finally with other species. Peroxy radical abstraction and addition reactions with closed-shell species are sufficiently slow to be of negligible importance at temperatures pertinent to the atmosphere and are consequently not covered. Data on both the kinetics and mechanisms of peroxy radical reactions are considered.The role of peroxy radicals as intermediates in the atmospheric degradation of volatile organic compounds and in the production of ozone in the troposphere under both low and high [NO_x] conditions is discussed. The involvement of peroxy radicals in night-time oxidation chemistry and the oxidation of halocarbons is also indicated. The techniques used for the difficult measurement of peroxy radical concentrations in the atmosphere are described, together with the results to date.Finally, some tentative suggestions as to further avenues of research are made, based on the data reviewed here and with particular reference to the solution of outstanding problems in atmospheric chemistry. Although a great deal of progress has been made in recent years, it is clear that additional work is needed in most areas covered by this review. New, sensitive and selective laboratory techniques are required for studies of peroxy radical kinetics and high level ab initio calculations would help design laser-based detection techniques. Further product studies of photooxidation systems are needed, particularly as a function of temperature. Recent work has shown that the rate constants for RO₂ + HO₂ reactions used in modelling studies may be too low; if so, these reactions will be correspondingly more important than previously believed in tropospheric oxidation. Recent kinetic studies of the potentially important reactions of methylperoxy radicals with ClO and NO₃ need to be confirmed and mechanistic work is necessary. Although substantial progress has been made towards the monitoring of peroxy radical concentrations in the atmosphere, more work is needed, both on measurements and the development of new techniques.     

Advanced process systems design technology for pollution prevention and waste treatment

The paper presents a generic process synthesis and optimisation tool suitable to take up applications in the design of waste treatment systems and in pollution prevention. The main component of the technology is a generalized process synthesis representation for simultaneous consideration of reaction and separation in multiphase systems that is amenable for stochastic optimisation. The flexibility of the representation allows applications to overall process synthesis problems as well as to decomposed reactor, reactive separation and mass exchange network design problems. Applications of the synthesis framework to waste water treatments processes using activated sludge and to natural gas sweetening in hybrid membrane-adsorption processes are presented. The paper highlights the use of the systematic technology in environmental systems design and shows how novel designs of improved performance as well as optimal design knowledge can be revealed using the systematic design framework. Context abstract: Environmental process systems for waste treatment and pollution prevention become increasingly complicated to design. There is a strong need for technology that provides systematic decision support to the process synthesis team in order to enable the timely selection of processes that operate close to the performance limits of the system under consideration. Conventional, optimisation-based process design technology is severely limited by the number of design decisions they can support simultaneously as well as by the increasingly complex process models required for the meaningful mathematical representation of environmental process systems. We have devised an optimisation-based process design methodology for integrated reaction and separation systems that overcomes major limitations of existing tools. This paper illustrates the use of this technology to provide systematic decision-support to the environmental process systems designer.     

基于混合FE-SEA方法的加筋板宽频隔声预计

目的预测有限尺寸加筋平板结构宽频范围内的隔声特性,指导飞行器结构声学设计。方法基于混合FE-SEA方法,对单向加筋平板结构开展宽频隔声预计。同时,在标准声学试验室对其进行隔声测试,并将FE-SEA法预计结果与测试结果、SEA方法计算结果进行对比分析。结果与SEA法相比,混合FE-SEA方法在50 Hz~10 kHz频带内的预计结果与试验结果更为吻合,其更适用于宽频隔声预计;在400 Hz~10 kHz的中高频段内,FE-SEA方法预计结果与试验结果基本相同;在50 Hz~400 Hz的低频段内,FE-SEA方法预计结果略高于试验结果,且随频率降低,偏差会逐渐增大。结论进行加筋板结构声学设计时,为了获得精确的宽频隔声预计结果,可首先选用FE-SEA方法。FE-SEA方法预计结果在中高频段可直接使用,在低频段仅能作为参考,使用时应当进行修正。     

Modeling and optimization of turning duplex stainless steels

The attractive combination of high mechanical strength, good corrosion resistance and relatively low cost has contributed to making duplex stainless steels (DSSs) one of the fastest growing groups of stainless steels. As the importance of DSSs is increasing, practical information about their successful machining is expected to be crucial. To address this industrial need, standard EN 1.4462 and super EN 1.4410 DSSs are machined under constant cutting speed multi-pass facing operations. A systematic approach which employs different modeling and optimization tools under a three phase investigation scheme has been adopted. In phase I, the effect of design variables such as cutting parameters, cutting fluids and axial length of cuts are investigated using the D-Optimal method. The mathematical models for performance characteristics such as; percentage increase in radial cutting force (%F_r), effective cutting power (P_e), maximum tool flank wear (VB_max) and chip volume ratio (R) are developed using response surface methodology (RSM). The adequacy of derived models for each cutting scenario is checked using analysis of variance (ANOVA). Parametric meta-heuristic optimization using Cuckoo search (CS) algorithm is then performed to determine the optimum design variable set for each performance. In the phase II, comprehensive experiment-based production cost and production rate models are developed. To overcome the conflict between the desire of minimizing the production cost and maximizing the production rate, compromise solutions are suggested using Technique for Order Preference by Similarity to Ideal Solution (TOPSIS). The alternatives are ranked according to their relative closeness to the ideal solution. In the phase III, expert systems based on fuzzy rule modeling approach are adopted to derive measures of machining operational sustainability called operational sustainability index (OSI). Artificial neural network (ANN) based models are developed to study the effect of design variables on computed OSIs. Cuckoo search neural network systems (CSNNS) are finally utilized to constrainedly optimize the cutting process per each cutting scenario. The most appropriate cutting setup to ensure successful turning of standard EN 1.4462 and super EN 1.4410 for each scenario is selected in accordance with conditions which give the maximum OSI.     

户外测试检验加速测试

探讨了加速老化测试存在的问题,阐述了户外暴露测试的重要性,指出应该利用户外暴露测试来检验加速老化。使用正确的测试程序,户外暴露测试．-j-~在较短的时间内获得较好的测试结果。采用正确的测试设计、恰当的评估方法、可靠的统计分析及应用参照样品等,可使测试者确定加速程度及加速测试与户外暴露测试的相关系数,以确保加速测试结果的正确性。     

Conceptual design of an integrated heating system at LKAB Malmberget with consideration of social-environmental damage costs

LKAB Malmberget is a Swedish mining site located at Malmberget, Sweden. Seven boiler centers are located in the north part of Malmberget. There are no connections in between these boiler centers, meaning that it is a decentralized heating system. The heat generated is used to heat up buildings and for mine ventilation air mainly during the cold periods. The heat is mainly provided from electric and oil boilers. However, most boilers under use are over 20 years old, and it is time to retrofit the boiler system and infrastructure. The purpose of this work is to design and optimize the heating system by introducing an integrated concept to minimize the heat production cost.An optimization model based on the mixed integer linear programming (MILP) has been developed. Several technical options have been considered in a new centralized heating system. The optimization principle is based on two kinds of perspectives: current price and external costs. With consideration of environmental and health damage from society concerns point of view, instead of environmental taxes in the current price perspective, the monetary values of externalities due to pollutants such as CO₂, NO_x, SO₂ and particulates emitted from the heating system are included. On the basis of data input and assumptions, modeling results indicate that a lower cost could be achieved when a waste heat recovery boiler is installed at the older pelletization plant to recover sensible heat from flue gas. This technical option is the best solution or at least contributes to the best solution in all optimization results. Including the externality cost is useful for making fair evaluation of the social-environmental impacts of the alternatives.     

Development of a biaxial loading frame for sheet metal

Characterization of the evolving yield loci and forming limit diagrams for sheet materials under biaxial loading is necessary for the development of accurate sheet metal forming process simulations. Biaxial tension testing has been shown to have significant advantages over the current computational and experimental methods for such material characterization; however, the few commercially available loading frames are far too large and expensive to be practical for most metal forming research laboratories. In this paper, the design of a practical servohydraulic biaxial loading frame is presented. The design, control, and operation of the loading frame are discussed in detail, and experimental data is provided to validate the effectiveness of the control system with respect to specimen center shifting.     

Polarisation vision: overcoming challenges of working with a property of light we barely see

In recent years, the study of polarisation vision in animals has seen numerous breakthroughs, not just in terms of what is known about the function of this sensory ability, but also in the experimental methods by which polarisation can be controlled, presented and measured. Once thought to be limited to only a few animal species, polarisation sensitivity is now known to be widespread across many taxonomic groups, and advances in experimental techniques are, in part, responsible for these discoveries. Nevertheless, its study remains challenging, perhaps because of our own poor sensitivity to the polarisation of light, but equally as a result of the slow spread of new practices and methodological innovations within the field. In this review, we introduce the most important steps in designing and calibrating polarised stimuli, within the broader context of areas of current research and the applications of new techniques to key questions. Our aim is to provide a constructive guide to help researchers, particularly those with no background in the physics of polarisation, to design robust experiments that are free from confounding factors.     

The V-Cycle for system innovation translating a broad societal need into concrete product service solutions: the multifunctional centre Apeldoorn case

In this paper a system innovation project is presented in which a sustainable future vision with a long-term perspective was developed and translated into short-term commercial innovation opportunities, which in turn can benefit the longer-term vision of society.The case described is a three-year innovation project, in which TNO worked together with a local care organisation De Woonmensen, and a SME company My Bodyguard BV. Starting with the challenges related to the aging society, future visions were developed that focussed upon the need of elderly people to continue living independently for a longer time, instead of moving to an expensive in-house care facility. During the process, the long-term vision was translated into short-term innovation concepts or solution elements on the individual user level, which focussed on the problem of elderly patients wandering off and getting lost. On the micro technological level, this resulted in the development of a personal localization system to enable caregivers to know where a certain patient is, based on a combination of GPS and GSM technology, the ‘Guide Me’ system.The four challenges addressed in this analysis focus on the relation between the broad future vision and the separate solution elements, the detailed design of the solution elements, the distinction between the design, implementation and evaluation of the elements, and the changing role of actors during the system innovation process. To deal with these issues, the V-Cycle of system innovations model was introduced that distinguishes between the various complexity or abstraction levels of the system in combination with the time perspective needed for change. Introducing this model proved to be helpful to clarify the four issues mentioned and was found to be a useful tool to evaluate system innovation projects after they were implemented, as well as supporting the projects before and during their implementation.