72 research outputs found
3-D Printed Guns: A Developing Technology with Dangerous Potential
No full textAs an up-and-coming technology, the full potential of 3-D printing has yet to be realized, and its movement toward at-home consumers may cause problems that still remain undiscovered. Paired with the inconsistencies between various state and federal laws, the continued development of 3-D printed weapons could pose a major threat to our nation’s security. Left untouched, current trends could allow for the issue of untraceable weapons to spiral out of control and beyond repair. 3-D printing is undoubtedly one of the world’s most revolutionary technologies, but it could become one of the world’s most dangerous if left without limits.
Stress analysis in the beater relief of a beater wheel
No full textPresented is numerically efficient finite element discrete model which uses the submodeling technique. The application of the model was to analyze stresses in the beater relief of the beater wheel. Results of the simulation and conclusions as well as the benefits of the adopted modelling methodology in terms of the time needed to find the solution were presented. The relationship between the modelling approach applied and the size of files generated during the analysis was highlighted.</jats:p
A Sub-modeling Approach for Building Numerically Efficient Discrete Model for Shape Optimization - A Case Study
No full textAnalysis of Hot Stamping Tool Cooling System—A Case Study
No full textOne of the important steps in the design of hot stamping tools is the analysis of their cooling system. This article presents an authorial, two-stage approach to solving this problem. The first stage consisted of a series of simulations of the hot stamping process in the Autoform package, with initial selection of shape and arrangement of cooling channels. These results allowed for the design of the tool for which the coupled thermal-flow analysis was carried out. The correctness of the adopted design assumptions has been confirmed by experimental tests. A trial series of drawpieces made in production conditions meet the requirements for hardness, mechanical properties, and appropriate microstructure. The presented procedure has become the practice of the drawpiece producers
Efficient calculation model of textile machine cylinder for parametric optimization with the use of the FEM method
No full textW artykule przedstawiono rozwiązanie zadania poszukiwania optymalnego kształtu i wymiarów bębna głównego zgrzeblarki wałkowej z punktu widzenia minimalizacji amplitudy ugięcia. Do analiz przygotowano parametryczny, efektywny obliczeniowo, dyskretny model bębna z wykorzystaniem MES. Do jego budowy użyto superelementów zastosowanych w niestandardowy sposób. Pokazano korzyści wynikające z przyjętej metodyki modelowania.The paper presents a solution to the problem of finding optimal shape and dimensions of the carding machine main cylinder from the point of view of minimizing the amplitude of deflection. With the use of the FEM method, a computationally efficient parametric discreet model of the cylinder was prepared for the analyzes. The model’s construction involved using superelements in a non-standard way. Benefits of the adopted modelling methodology have been shown
Control System for Automated Technological Process of Hot Stamping—A Case Study
No full textHot forming process has been used more and more frequently in the production of body structures of modern ultralight passenger cars for several years. This, unlike the commonly used cold stamping, is a complicated process, combining heat treatment and plastic-forming methods. For this reason, permanent control at each stage is required. This includes, among others, measurement of the blank thickness, monitoring its heating process in the suitable atmosphere in the furnace, control of the forming process itself, measurement of shape-dimensional accuracy as well as mechanical parameters of the finished drawpiece. This paper discusses the method of controlling the values of production parameters during the hot stamping process of a selected drawpiece. For this purpose, digital twins of the production line and the stamping process, made in accordance with the assumptions of Industry 4.0, have been used. Individual components of the production line with sensors for monitoring process parameters have been shown. The system’s response to emerging threats has also been described. The correctness of the adopted values is confirmed via tests of mechanical properties and the assessment of the shape-dimensional accuracy of a drawpiece test series
The process of preparing special blanks and hot stamping of a B-pillar with variable mechanical parameters
No full textW artykule opisano badania dotyczące laserowego spawania płaskich formatek o jednakowej grubości, wykonanych z dwóch różnych gatunków stali stosowanych do tłoczenia na gorąco. Przedstawiono opracowane w ramach projektu badawczego specjalne oprzyrządowanie do spawania formatek, na którym przetestowano proces laserowego spawania formatek o grubości 2 mm wykonanych z dwóch typów stali: Usibor 1500 i Usibor 2000, wykorzystując różne parametry spawania. Dodatkowo przedstawiono proces tłoczenia na gorąco słupka B samochodu osobowego z dwóch formatek spawanych laserowo z dodatkową nakładką. Przedstawiono wyniki komputerowej symulacji tłoczenia przeprowadzonej przy użyciu pakietu Autoform a także opisano konstrukcję tłocznika. Wykonano próbną serię 300 wytłoczek. Przeprowadzono badania podstawowych właściwości mechanicznych, takich jak granica plastyczności (Rp0.2), granica wytrzymałości (Rm) oraz twardość HV.Badania realizowano przy finansowaniu w ramach RPO WSL 2014-2020 Oś priorytetowa I. Nowoczesna gospodarka Działanie 1.2. Badania, rozwój i innowacje w przedsiębiorstwach w ramach projektu: Prace rozwojowe nad innowacyjnym słupkiem B o 3 zróżnicowanych pod względem parametrów mechanicznych strefach, z zastosowaniem nowych rodzajów stali oraz udoskonalonej technologii spawania laserowego TWB
Warsaw airports 2018–2030
No full textW artykule omówiono obecny stan portów lotniczych obsługujących aglomerację warszawską (Lotnisko Chopina oraz Modlin), przedstawiono problemy, które uniemożliwiają swobodny wzrost ruchu lotniczego na obu lotniskach wraz z zaproponowaniem rozwiązań, które pomogą złagodzić te problemy. Ponadto odniesiono się do planów budowy Centralnego Portu Komunikacyjnego w gminie Baranów, a także do propozycji budowy drugiego lotniska mającego odciążyć Lotnisko Chopina do czasu uruchomienia CPK. Oceniono także jak poszczególne rozwiązania wpłyną na port przesiadkowy Polskich Linii Lotniczych LOT w Warszawie, które będą musiały się zmierzyć z rosnącym zatłoczeniem Lotniska Chopina (a tym samym wyczerpującą się przepustowość) w stosunku do bardzo ambitnych planów rozwoju przewoźnika w ciągu najbliższych kilku lat.The aim of this paper is to present airports for the Warsaw agglomeration (Chopin Airport and Warsaw Modlin Airport). The lecture presents problems limiting the development of these airportsand it shown proposed solutions would minimize these problems. Also related to the plans for the construction of the Polish Central Hub, which will be located 40 km from Warsaw. Also presents a plan for the construction of another airport near Warsaw until the CPK will be launched. The paper also described the current situation of the LOT Polish Airlines, who has a hub at Chopin Airport. Also analyzed ambitious LOT’s development plan in relation to the limited capacity of the Warsaw Chopin Airpor
Parametric optimization with the use of numerically efficient finite element models
No full textThis article presents numerically efficient computational models for solving exemplary problems of parametric optimization with the use of the finite element method. Building computational models involved applying a non-standard usage of superelements. In the problems of static analysis, static condensation method was used for model reduction. In the case dynamic problem, component mode synthesis method was applied. The advantages of the adopted modelling methodology were shown with reference to the time required to find the optimal solution. The issue, so far overlooked in this type of analyses, of the relationship between the modelling methodology and the size of the files generated during the analysis was also mentioned
Genetic variation in the choline O-acetyltransferase gene in depression and Alzheimer's disease: the VITA and Milano studies
No full textLinkage studies point to the long arm of chromosome 10 being a susceptibility region for Alzheimer's disease (AD). Additionally, the gene choline O-acetyltransferase (CHAT) located on chromosome 10 was discussed for conveying risk towards AD, but the results are ambiguous. We examined a possible association of nineteen single-nucleotide polymorphisms (SNPs) in the CHAT gene in a longitudinal cohort study, the Vienna Tansdanube Aging (VITA)-study, in which all subjects were 75 years old at baseline. For replication, we used a more heterogeneous case-control sample from Milano with early and late AD. Nominal allelic and genotypic associations with AD risk in the cross-sectional VITA sample were found for rs3810950 (p = 0.038 for genotype, OR = 1.66 95% CI 1.03-2.68, p = 0.052 allele-wise). When combining both VITA- and Milano study rs3810950 was significantly associated with AD (p(combined) = 0.01634; power = 82%). This association was highly significant for APOEε4 carriers (p = 0.009 for genotype, OR = 3.21 95% CI 1.43-7.19 p = 0.007 allele-wise). Furthermore, an association of rs1880676 with AD was specific to carriers of the APOEε4 risk allele (p = 0.008, genotype; OR = 3.47 95% CI 1.50-8.01 p = 0.005 allele-wise). For depressive symptoms, we found a nominally significant association of rs3810950 with minor and major depression (p = 0.023, genotype; p = 0.008, allele). Applying Benjamini and Hochberg correction these associations could not be confirmed and also not be replicated in the more heterogeneous Milano sample. While our data therefore do not seem to support a major role for CHAT genetic variation in geriatric depression and AD, there might be a minor contribution in geriatric patients with depression and late onset AD, in particular those carrying the APOEε4 genotype
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