Model System For Production Research Articles

Layout model system for production of plants inorganic solid waste recycling for small cities

In the past, garbage was not a problem so emphasized by society, however, the significant increase in consumption has made waste management one of the main areas of study throughout the world. This study aimed to identify, describe and compare models of layout of the production system of recycling plants, thus providing better prospects in the design of these much needed projects in the cities of the new sustainable society that wants to build. The main object of study is the layout models of productive systems for recycling plants in order to identify, describe and compare them. To this end, we used bibliographic or secondary data, in books, periodicals, and dissertations on the theme in question. The main result was to scan the literature, with subsequent identification and description of 04 (four) layout models for recycling plants. When reviewing Layouts broached, it can be seen that there are some similarities and differences between them. It is expected that the theoretical background, results and discussions presented in this study may support further studies on the physical arrangement ideal for implementation of recycling plants for small municipalities.

Life cycle assessment of Swiss farming systems: II. Extensive and intensive production

Extensive or low-input farming is considered a way of remedying many problems associated with intensive farming practices. But do extensive farming systems really result in a clear reduction in environmental impacts, especially if their lower productivity is taken into account? This question is studied for Swiss arable cropping and forage production systems in a comprehensive life cycle assessment (LCA) study. Three long-term experiments (DOC experiment comparing bio-dynamic, bio-organic and conventional farming, the “Burgrain” experiment including integrated intensive, integrated extensive and organic systems and the “Oberacker” experiment with conventional ploughing and no-till soil cultivation, are considered in the LCA study. Furthermore, model systems for arable crops and forage production for feeding livestock are investigated by using the Swiss Agricultural Life Cycle Assessment method (SALCA). The analysis covers an overall extensification of cropping systems and forage production on the one hand and a partial extensification of fertiliser use, plant protection and soil cultivation on the other. The overall extensification of an intensively managed system reduced environmental impacts in general, both per area unit and per product unit. In arable cropping systems medium production intensity gave the best results for the environment, and the intensity should not fall below the environmental optimum in order to avoid a deterioration of eco-efficiency. In grassland systems, on the contrary, a combination of both intensively and extensively managed plots was preferable to medium intensity practices on the whole area. The differences in yield, production intensity and environmental impact were much more pronounced in grassland than in arable cropping systems. Partial extensification of a farming system should be conceived in the context of the whole system in order to be successful. For example, the extensification solely of fertiliser use and soil cultivation resulted in a general improvement in the environmental performance of the farming system, whereas a reduction in plant protection intensity by banning certain pesticide categories reduced negative impacts on ecotoxicity and biodiversity only, while increasing other burdens such as global warming, ozone formation, eutrophication and acidification per product unit. The replacement of mineral fertilisers by farmyard manure as a special form of extensification reduced resource use and improved soil quality, while slightly increasing nutrient losses. These results show that a considerable environmental improvement potential exists in Swiss farming systems and that a detailed eco-efficiency analysis could help to target a further reduction in their environmental impacts.

Multidisciplinary Collaborative Product Modeling in Distributed Network Environment

Based on the analysis of product model characteristics of multidisciplinary collaborative design (MCD), multiple views model expressed by an extended object-oriented method is introduced to satisfy the requirements of different discipline designers for product information interaction and share. A product modeling system for multidisciplinary collaborative design is proposed, and the modeling method of discipline view model under the network environment is given, which can effectively support the evolution of product model and improve the flexibility of product modeling. The clutch is illustrated to validate the proposed methods.

Assembly process simulation of toleranced products

Virtual assembly based on virtual reality provides a low-cost and rapid prototyping method for products' assembly, and tolerances have become a key technique of information integration in CAD/CAM. Integrating tolerances into virtual assembly is therefore a completely new approach. Many representations of assembly modelling have focused on capturing the mating constraints between components. Using the related theories, the expression of the constraints for assembly components and the method of extracting the constraints and mate feature matrix from the CAD software of Pro/Engineer are proposed, and finally, they are used to control and simulate the assembly process. A toleranced product modelling system based on the virtual reality is developed, and the use of tolerances is discussed by an example. In our research, we found that virtual assembly becomes more available by integrating tolerances into it.

Data integration from product design to assembly planning in a collaborative environment

Virtual Manufacturing (VM) evaluates products in Virtual Environments (VEs) before actual production. A key issue in VM systems is the integration of design information into different product development stages. A product design model has to be accessible and reusable by downstream applications, such as product process planning and assembly planning. However, existing product modelling systems cannot fully support the downstream applications. This paper presents a method of extracting product design information from its CAD models for assembly planning and tool accessibility analysis. A web-based interface is developed for the system implementation and the process simulation. [Received 1 December 2008; Revised 21 July 2009; Accepted 31 July 2009]

Study of Toleranced Products Modeling Based on Virtual Reality

Virtual assembly based on the virtual reality gives a low-cost and rapid prototyping method for products’ assembly, and tolerances have become a key technique of information integration in CAD/CAM. It will be a new task about how to integrate tolerances into virtual assembly. A toleranced product model based on the virtual reality is constructed for the virtual assembly, and the essential data is saved and managed in database. Model transform interface software is developed, which is a special software that users can get the essential data without any users’ acting. The geometric model of products is constructed in the virtual reality, and the method of getting assembly information, dimensions, and tolerances is proposed. A toleranced product modeling system based on the virtual reality is developed, and the using of tolerances is discussed by an example.

Sphingosine 1-Phosphate Receptor Signaling

The sphingosine 1-phosphate (S1P) receptor signaling system is a productive model system. A hydrophobic zwitterionic lysophospholipid ligand with difficult physical properties interacts with five high-affinity G protein-coupled receptors to generate multiple downstream signals. These signals modulate homeostasis and pathology on a steep agonist concentration-response curve. Ligand presence is essential for vascular development and endothelial integrity, while acute increases in ligand concentrations result in cardiac death. Understanding this integrated biochemical system has exemplified the impact of both genetics and chemistry. Developing specific tools with defined biochemical properties for the reversible modulation of signals in real time has been essential to complement insights gained from genetic approaches that may be irreversible and compensated. Despite its knife-edge between life and death, this system, based in part on receptor subtype-selectivity and in part on differential attenuation of deleterious signals, now appears to be on the cusp of meaningful therapy for multiple sclerosis.

Brain-Derived Neurotrophic Factor and TrkB Modulate Visual Experience-Dependent Refinement of Neuronal Pathways in Retina

Sensory experience refines neuronal structure and functionality. The visual system has proved to be a productive model system to study this plasticity. In the neonatal retina, the dendritic arbors of a large proportion of ganglion cells are diffuse in the inner plexiform layer. With maturation, many of these arbors become monolaminated. Visual deprivation suppresses this remodeling. Little is known of the molecular mechanisms controlling maturational and experience-dependent refinement. Here, we tested the hypothesis that brain-derived neurotrophic factor (BDNF), which is known to regulate dendritic branching and synaptic function in the brain, modulates the developmental and visual experience-dependent refinement of retinal ganglion cells. We used a transgenic mouse line, in which a small number of ganglion cells were labeled with yellow fluorescence protein, to delineate their dendritic structure in vivo. We found that transgenic overexpression of BDNF accelerated the laminar refinement of ganglion cell dendrites, whereas decreased TrkB expression or retina-specific deletion of TrkB, the cognate receptor for BDNF, retarded it. BDNF-TrkB signaling regulated the maturational formation of new branches in ON but not the bilaminated ON-OFF ganglion cells. Furthermore, BDNF overexpression overrides the requirement for visual inputs to stimulate laminar refinement and dendritic branching of ganglion cells. These experiments reveal a previously unrecognized action of BDNF and TrkB in controlling cell-specific, experience-dependent remodeling of neuronal structures in the visual system.

Urinary tract infection in women: New pathogenic considerations

Urinary tract infection (UTI) is a common clinical syndrome in women. Most UTIs are caused by Escherichia coli. UTI has become a productive and accessible model system for studying the molecular details of how bacteria interact with mucosal surfaces and the nature of the host response. Important advances in the past year include the discovery of new virulence determinants; better understanding the pathogenic role of the ubiquitous motility organelle, the flagellum; and defining aspects of coordinate regulation of virulence determinants in the pathogenesis of UTI.

A system for the design and manufacture of feature-based parts through the Internet

The Internet has enabled the development of applications for supporting the design and manufacturing of industrial parts and products. Some actions have been performed by some research groups in different parts of the world aiming at conceiving product modeling systems based on the technology of features to allow information sharing, both for the activities related to product development and for manufacturing. This paper describes the implementation of the WebMachining system ( http://www.WebMachining.AlvaresTech.com ) developed in a context of e-Mfg and concurrent engineering, aimed at integrating CAD/CAPP/CAM for the remote manufacturing of feature-based cylindrical parts with symmetrical and asymmetrical features through the Internet, using an approach based on multi-agent systems. The information referring to the features is manipulated through a relational database management system. The graphic user interface (GUI) is implemented in Java and HTML. In this GUI, the user inputs the information on the design features that compose the part. Then these data are sent to the server. Since the part is cylindrical, the user models the part in two dimensions, and it can be visualized as three-dimensional through VRML. A database was implemented that stores the information on the product modeled by features, containing information associated with the form features, material features, tolerance features and technological features. These combined pieces of information allow the mapping of design features into machining features, which is fundamental for process planning. The database information is described in this article through the IDEF1X information model.

Managing stakeholder requirements in a product modelling system

In order to develop a well-balanced product, it is necessary to consider not only the customers, but also all the other stakeholders throughout the product's life cycle. A holistic view is needed i...

Managing stakeholder requirements in a product modelling system

In order to develop a well-balanced product, it is necessary to consider not only the customers, but also all the other stakeholders throughout the product's life cycle. A holistic view is needed in order to manage all criteria, considering as many perspectives and interests as possible. This paper presents a model that provides a common understanding for stakeholders involved, together with the requirements, functions and sub-systems of the product being developed. The model supports the decision making process, and supports the designer to balance the interests of different stakeholders and the related functions. This results in a product developed according to all known demands from various stakeholders. This, in turn, will enhance the possibility of success in the market. The model has been applied in an industrial case study.

The psychology of songbird acoustic communication: Open-ended categorization and its role in songbird perception

Songbirds are used as a model system for understanding vocal learning, production, and perception. Over the past several years one particular aspect of songbird communication has been examined, vocal perception that has parallels with human speech perception, namely, the perception of natural acoustic categories in songbird vocalizations. A series of studies will be presented highlighting the role of open-ended categorization in the perception of vocalizations in songbirds. Attempts will be made to make the case that open-ended categorization is a fundamental proximate mechanism for acoustic communication in both humans and songbirds, that it is used in a highly analogous manner in each, and future directions will attempt to integrate these two areas of research and, ultimately, lead to a more complete understanding of acoustic communication in animals.

Kinetic modeling of lipase catalyzed hydrolysis of ( R/ S)-1-methoxy-2-propyl-acetate as a model reaction for production of chiral secondary alcohols

The Candida antarctica lipase B catalyzed kinetic resolution of ( R/ S)-1-methoxy-2-propyl-acetate was studied as a model system for the biocatalytic production of chiral secondary alcohols. For this purpose, a kinetic model is proposed involving both enantiomers of this reaction using model discrimination and parameter identification. Starting from a ping–pong bi–bi mechanism, a simplified model with sensitive parameters was derived for the R- and S-enantiomer, respectively. It was validated at pH 7.0, using time-course measurements at varying temperatures (30–60 °C) and initial substrate conditions (0.05–1.5 M). This model was then used for mechanistic interpretation of the kinetic resolution on a biochemical level. The effect of temperature on kinetic parameters and enantiomeric ratio was investigated and compared to findings from the field of molecular modeling to obtain a better understanding of the reaction system for process design. Values of 21.2 and 9.7 kJ mol −1 were determined for the enthalpic (Δ R– S Δ H ‡°) and the entropic (– T·Δ R– S Δ S ‡°) contribution of the difference in transition state energy of both enantiomers at 30 °C. High enantiomeric ratio's ( E of 47–110) especially at lower temperatures, in addition to enzyme activity at a wide pH range, indicate this biotransformation is a promising example for the industrial production of chiral secondary alcohols.

Highly Active Mutants of Carbonyl Reductase S1 with Inverted Coenzyme Specificity and Production of Optically Active Alcohols

A wild type NADPH-dependent carbonyl reductase from Candida magnoliae (reductase S1) has been found not to utilize NADH as a coenzyme. A mutation to exchange the coenzyme specificity in reductase S1 has been designed by computer-aided methods, including three-dimensional structure modeling and in silico screening of enzyme mutants. Site-directed mutagenesis has been used to introduce systematic substitutions of seven or eight amino acid residues onto the adenosine-binding pocket of the enzyme according to rational computational design. The resulting S1 mutants show NADH-dependency and have lost their ability to utilize NADPH as a coenzyme, but retain those catalytic activities. Kinetic parameter V(max) and K(m) values of those mutants for NADH are 1/3- to 1/10-fold those of the wild type enzyme for NADPH. As a model system for industrial production of optically active alcohols, the S1 mutants can be applied to an asymmetric reduction of ketones, cooperating with a coenzyme-regeneration system that uses an NAD-dependent formate dehydrogenase.

Integrating product and process information in the construction sector

Collaborative working in construction projects is becoming very important as many activities are usually performed involving actors based in different geographical locations. Recent years have seen the emergence and development of a plethora of visual software modelling tools, modelling standards, methods for wide enterprise concurrent engineering, and techniques for exchanging and sharing construction information between software applications. This paper describes an integrated product and process information modelling system developed to manage information essential to construction managers. The integrated conceptual model is based on information and functional requirements and was developed to model both product and process information in a hierarchical manner. The also shows how the model relates to practice, and presents the benefits that are gained from structuring information using this approach.

The application of information modelling methodologies: the HIPPY approach to integrated project modelling

Due to the lack of effective coordination between stages of the construction process, the importance of integrating information modelling techniques with the view to creating a generic integrated product and process model that is applicable to all stages of a construction project's life cycle, is being recognised by the architecture, engineering and construction (AEC) industries and the computer integrated construction (CIC) research community. However, improved methods are still needed to assist the developer in the definition of information model structures. Current available modelling methods and standards can only help at certain stages of the information modelling process. This paper proposes a prototype of a generic Hyper-Integrated Product and Process modelling information system (HIPPY). The main functions of the prototype include integrating information models with document files using data transferring techniques and multiple software applications. Functions, software architecture, implementation and exploitation of the integrated modelling framework are presented. The paper first reviews existing modelling efforts addressing integration in the AEC domain. It explores the advantages of combining modelling methodologies in the definition of the structure for integrating data that will support computer applications through the project life cycle. The approach adopted in this paper uses unified modelling language (UML), IDEF0 and scheduling charts (project planning). The combined use of these methods means that the weaknesses of each could be counteracted by the strengths of others. Finally, the user-interface through which project participants interact with multiple applications in the integrated environment is presented.

The lateral line of zebrafish: a model system for the analysis of morphogenesis and neural development in vertebrates

The lateral line of the zebrafish has many of the advantages that made the sensory organs of Drosophila a very productive model system: 1) it comprises a set of discrete sense organs (neuromasts) arranged in a defined, species-specific pattern, such that each organ can be individually recognized; 2) the neuromasts are superficial and easy to visualize, and the innervating neurons are easy to label; 3) the sensory projection is simple yet reproducibly organized. Here we describe some of the tools that can be used to investigate the development of this system, and we illustrate their usefulness with specific exemples. We conclude that the lateral line is uniquely suited among vertebrate sensory systems for a molecular, cellular and genetic analysis of pattern formation and of neural development.

Development of a semantic product modeling system for initial hull structure in shipbuilding

In the initial stage of ship design, designers represent geometry, arrangement, and dimension of hull structures, which correspond to product model information, with 2D geometric primitives such as points, lines, arcs, and drawing symbols on 2D drawings. However, designers must translate the product model information defined on the 2D drawings more intelligently in the following design stages. Thus, design semantics could be lost and design processes that follow could be delayed because of errors by mistranslating the information. Here, design semantics mean design intents of the designer, that is, functions and structures which the product must have. In this study, a semantic product model data structure of an initial ship hull structure was proposed, and a semantic product modeling system was developed based on the proposed data structure. The proposed data structure can store semantic product model information such as product design results with the use of 2D wire frame geometrical data, part attributes, and design knowledge. Hence, this information can be used to generate a 3D solid model and production material information for CAPP as needed. The applicability of the proposed data structure and the developed system was verified by applying them to the deadweight 300,000 ton of Very Large Crude oil Carrier’s product modeling procedure. The application results showed that the proposed data structure and the developed system can be efficiently used for overall initial ship design environment.

Functional model for the development of an inspection integration framework

Product dimensional inspection is set as one of the essential parts of the production process, where not only product quality test is checked but also its interaction with other development stages in a minimal time. This enables a feedback to make quicker production and design decisions, provides updated information about the inspection processes to be shared and used in the new development processes, and permits the simultaneous work in the preparation of the inspection processes themselves. For this aim, it is necessary, as it occurs in the STEP framework, to develop an application context that includes all dimensional inspection aspects, from the geometrical and measurement aspects to those related to administration and configuration product data. This paper proposes a solution to integrate the dimensional inspection process with coordinate measuring machines with the design and manufacturing processes. Integration is achieved through a common product information model. A functional information model, a reference information model and an interpreted information model have been defined. The interaction with other information models associated to other activities of the production cycle is possible. Tests have been made of the possibility of making the inspection information interchange at the operation level instead of making it at the CMM trajectory level, as it is the case of the current DMIS format. This level of information definition is easier to put into effect, easier to interpret, and it is more productive. In order to test the validity of the information model, a real work environment which has been called IFCIA (Inspection Framework for Concurrent Information Access) has been developed. The IFCIA architecture is composed of a product modelling system, an object-oriented central database and a tri-dimensional coordinate measuring machine. The model has been implemented on an object-oriented product central database which is accessible by all the applications, so that the access to data is achieved in a concurrent way and in real time for the different agents involved in the development cycle, in a heterogeneous framework of platforms and applications. The generation and transference of the information among these systems are carried out exclusively according to data structures defined in the information model.