264 research outputs found
Product to process lifecycle management in assembly automation systems
Presently, the automotive industry is facing enormous pressure due to global competition and ever
changing legislative, economic and customer demands. Product and process development in the
automotive manufacturing industry is a challenging task for many reasons. Current product life
cycle management (PLM) systems tend to be product-focussed. Though, information about
processes and resources are there but mostly linked to the product. Process is an important aspect,
especially in assembly automation systems that link products to their manufacturing resources. This
paper presents a process-centric approach to improve PLM systems in large-scale manufacturing
companies, especially in the powertrain sector of the automotive industry. The idea is to integrate
the information related to key engineering chains i.e. products, processes and resources based upon
PLM philosophy and shift the trend of product-focussed lifecycle management to process-focussed
lifecycle management, the outcome of which is the Product, Process and Resource Lifecycle
Management not PLM only
A Laboratory Investigation on Thermal Properties of the Opalinus Claystone
Some aspects of the thermal behavior of the Opalinus claystone are investigated through laboratory tests conducted on a new hollow cylinder triaxial apparatus specially designed for studying the thermo-hydro-mechanical behavior of very low permeable materials. Two hollow cylinder samples are first resaturated under isotropic stress state equal to the mean effective in situ one in order to minimize swelling and induced damage during the resaturation phase. Two drained heating-cooling cycles are performed on the first sample of Opalinus claystone. During the first cycle, a thermo-elasto-plastic response similar to that of plastic clays with low overconsolidation ratio is obtained. The thermal hardening of the sample is demonstrated by the quasi-reversible behavior of the sample during the second heating-cooling cycle. An undrained heating test performed on the second sample of Opalinus claystone induces an excess pore pressure in this sample. This induced pore pressure is attributed to the higher thermal expansion coefficient of pore water compared to that of the solid phase. It is shown that the excess pore pressure generated in the sample by undrained heating cannot be modeled by considering the free water thermal expansion coefficient. The thermal expansion coefficient of the Opalinus claystone water is back-analyzed from the experimental results which show a higher value than free wate
Machine utilisation and breaksdown modelling for measuring productivity using virtual engineering simulation modelling
Results accuracy and reliability of discrete event simulation (DES) models to predict the production line productivities are based on the unexpected breakdowns taken place by machine faults or human errors. Process modeller practices DES modelling to incorporate these breakdowns and corresponding mainte-nances up-to the machine level. But actually breakdowns are potentially taken place at process level com-ponents inside the machine/stations. Domains like Virtual Engineering (VE) allow user to emulate the ac-tual machine build from components using the CAD data and thus define the components level processes model exist inside the machine station. Therefore author came with idea to integrate VE and DES model up-to component level processes to get an improved simulation modelling to analyse the machines breakdowns for validating pre-build and after-build phases of machine development. Initially in this arti-cle it was proposed to produce an algorithm required to integrate and model the component–level DES model driven from the available emulated data models
Biosynthesis and Characterization of Silver Nanoparticles by Aspergillus Species
Currently, researchers turn to natural processes such as using biological microorganisms in order to develop reliable and ecofriendly methods for the synthesis of metallic nanoparticles. In this study, we have investigated extracellular biosynthesis of silver nanoparticles using four Aspergillus species including A. fumigatus, A. clavatus, A. niger, and A. flavus. We have also analyzed nitrate reductase activity in the studied species in order to determine the probable role of this enzyme in the biosynthesis of silver nanoparticles. The formation of silver nanoparticles in the cell filtrates was confirmed by the passage of laser light, change in the color of cell filtrates, absorption peak at 430 nm in UV-Vis spectra, and atomic force microscopy (AFM). There was a logical relationship between the efficiencies of studied Aspergillus species in the production of silver nanoparticles and their nitrate reductase activity. A. fumigatus as the most efficient species showed the highest nitrate reductase activity among the studied species while A. flavus exhibited the lowest capacity in the biosynthesis of silver nanoparticles which was in accord with its low nitrate reductase activity. The present study showed that Aspergillus species had potential for the biosynthesis of silver nanoparticles depending on their nitrate reductase activity
Stabilization and Anticancer Enhancing Activity of the Peptide Nisin by Cyclodextrin-Based Nanosponges against Colon and Breast Cancer Cells
The great variability of cancer types demands novel drugs with broad spectrum, this is the case of Nisin, a polycyclic antibacterial peptide that recently has been considered for prevention of cancer cells growth. As an accepted food additive, this drug would be very useful for intestinal cancers, but the peptide nature would make easier its degradation by digestion procedures. For that reason, the aim of present study to investigate the protective effect of two different β-cyclodextrin-based nanosponges (carbonyl diimidazole and pyromellitic dianhydride) and their anti-cancer enhancement effect of Nisin-Z encapsulated with against colon cancer cells (HT-29). To extend its possible use, a comparison with breast (MCF-7) cancer cell was carried out. The physicochemical properties, loading efficiency, and release kinetics of Nisin complex with nanosponges were studied. Then, tricin-SDS-PAGE electrophoresis was used to understand the effect of NSs on stability of Nisin-Z in the presence of gastric peptidase pepsin. In addition, the cytotoxicity and cell membrane damage of Nisin Z were evaluated by using the MTT and LDH assay, which was complemented via Annexin-V/ Propidium Iodide (PI) by using flowcytometry. CD-NS are able to complex Nisin-Z with an encapsulation efficiency around 90%. A protective effect of Nisin-Z complexed with CD-NSs was observed in presence of pepsin. An increase in the percentage of apoptotic cells was observed when the cancer cells were exposed to Nisin Z complexed with nanosponges. Interestingly, Nisin Z free and loaded on PMDA/CDI-NSs is more selectively toxic towards HT-29 cells than MCF-7 cancer cells. These results indicated that nanosponges might be good candidates to protect peptides and deliver drugs against intestinal cancers
Product to process lifecycle management in assembly automation systems
Presently, the automotive industry is facing enormous pressure due to global competition and ever
changing legislative, economic and customer demands. Product and process development in the
automotive manufacturing industry is a challenging task for many reasons. Current product life
cycle management (PLM) systems tend to be product-focussed. Though, information about
processes and resources are there but mostly linked to the product. Process is an important aspect,
especially in assembly automation systems that link products to their manufacturing resources. This
paper presents a process-centric approach to improve PLM systems in large-scale manufacturing
companies, especially in the powertrain sector of the automotive industry. The idea is to integrate
the information related to key engineering chains i.e. products, processes and resources based upon
PLM philosophy and shift the trend of product-focussed lifecycle management to process-focussed
lifecycle management, the outcome of which is the Product, Process and Resource Lifecycle
Management not PLM only
PGC-1α is coupled to HIF-1α-dependent gene expression by increasing mitochondrial oxygen consumption in skeletal muscle cells
Mitochondrial biogenesis occurs in response to increased cellular ATP demand. The mitochondrial electron transport chain requires molecular oxygen to produce ATP. Thus, increased ATP generation after mitochondrial biogenesis results in increased oxygen demand that must be matched by a corresponding increase in oxygen supply. We found that overexpression of peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α), which increases mitochondrial biogenesis in primary skeletal muscle cells, leads to increased expression of a cohort of genes known to be regulated by the dimeric hypoxia-inducible factor (HIF), a master regulator of the adaptive response to hypoxia. PGC-1α-dependent induction of HIF target genes under physiologic oxygen concentrations is not through transcriptional coactivation of HIF or up-regulation of HIF-1α mRNA but through HIF-1α protein stabilization. It occurs because of intracellular hypoxia as a result of increased oxygen consumption after mitochondrial biogenesis. Thus, we propose that at physiologic oxygen concentrations, PGC-1α is coupled to HIF signaling through the regulation of intracellular oxygen availability, allowing cells and tissues to match increased oxygen demand after mitochondrial biogenesis with increased oxygen supply
Differential miRNAs expression pattern of irradiated breast cancer cell lines is correlated with radiation sensitivity
Radiotherapy is a fundamental step in the treatment of breast cancer patients. The treatment efficiency is however reduced by the possible onset of radiation resistance. In order to develop the effective treatment approach, it is important to understand molecular basis of radiosensitivity in breast cancer. The purpose of the present study was to investigate different radiation response of breast cancer cell lines, and find out if this response may be related to change in the microRNAs expression profile. MDA-MB-231 and T47D cells were subjected to different doses of radiation, then MTT and clonogenic assays were performed to assess radiation sensitivity. Cytofluorometric and western blot analysis were performed to gain insight into cell cycle distribution and protein expression. MicroRNA sequencing and bioinformatics prediction methods were used to identify the difference in microRNAs expression between two breast cancer cells and the related genes and pathways. T47D cells were more sensitive to radiation respect to MDA-MB-231 cells as demonstrated by a remarkable G2 cell cycle arrest followed by a greater reduction in cell viability and colony forming ability. Accordingly, T47D cells showed higher increase in the phosphorylation of ATM, TP53 and CDK1 (markers of radiation response) and faster and more pronounced increase in RAD51 and γH2AX expression (markers of DNA damage), when compared to MDA-MB-231 cells. The two cell lines had different microRNAs expression profiles with a confirmed significant differential expression of miR-16-5p, which targets cell cycle related genes and predicts longer overall survival of breast cancer patients, as determined by bioinformatics analysis. These results suggest a possible role for miR-16-5p as radiation sensitizing microRNA and as prognostic/predictive biomarker in breast cancer. © 2020, The Author(s)
Cyber security incident handling, warning and response system for the european critical information infrastructures (cyberSANE)
This paper aims to enhance the security and resilience of Critical
Information Infrastructures (CIIs) by providing a dynamic collaborative,
warning and response system (CyberSANE system) supporting and guiding security
officers and operators (e.g. Incident Response professionals) to recognize,
identify, dynamically analyse, forecast, treat and respond to their threats and
risks and handle their daily cyber incidents. The proposed solution provides a
first of a kind approach for handling cyber security incidents in the digital
environments with highly interconnected, complex and diverse nature
Integration approach to virtual-driven discrete event simulation for manufacturing systems
This is an Accepted Manuscript of an article published by Taylor & Francis in 'International Journal of Computer Integrated Manufacturing' on 11/06/2014, available online: https://doi.org/10.1080/0951192X.2014.924159.Virtual engineering (VE) environment helps to verify process and resource design through visualisation. By using VE, the impacts of re-configurability and new-process additions in the machine stops can be viewed down to the component level. On the other hand, discrete event simulation (DES) typically forecasts the system behaviour over a period of time to predict future performance. During pre-build stages of machines, DES analysis comes with uncertainties, as most of the parameters in the model are based on the assumptions. Therefore, it was aimed to use the validated and verified data, for example ‘process time’ of a machine component available from the VE-emulated systems, in the DES model. Thus, a systematic algorithm was proposed to integrate the VE tool data, with the DES. This article presents the development of a package known as ‘virtual-driven discrete event simulation’ (VDSim), used to establish an integration between the VE and DES domains. The success of this integration depends upon the quality of information and the compatibility of data flow between these independent domains. VDSim integration will help productivity planners and schedulers to get the best possible options for resource selection at stages even when the resource is not physically present
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