Analyse und Optimierung von Montagesystemen in der Elektronikproduktion

Im Rahmen dieser Dissertation werden ausgehend von Bauelemente- und Schaltungsträgertechnologien der Maschinenaufbau, die Steuerung und vor allem die Störeinflüsse auf die Maschinenfähigkeit von Bestückungssystemen in einem ganzheitlichen Ansatz systematisch untersucht. Die dabei gewonnenen Ergebnisse leisten einen Beitrag zur Weiterentwicklung und Sicherung der Maschinenleistung von Bestückungssystemen unter Berücksichtigung technologischer Randbedingungen, um eine wirtschaftlichere Verarbeitung innovativer Bauelementformen zu ermöglichen.In the context of this dissertation, the machine structure, the control and, above all, the interferences with the machine capability of assembly systems are systematically examined in a holistic approach based on component and circuit carrier technologies. The results obtained contribute to the further development and safeguarding of the machine performance of assembly systems, taking technological boundary conditions into account, in order to enable more economical processing of innovative component shapes

Development of Moroccan oasis: Theoretical inputs and practical outputs. Daraa-Tafilalet model

تعيش الواحات المغربية مند عقود وضعية مقلقة تنبئ عن العواقب المتسارعة لمختلف المخاطر البيئية التي تهدد هذا المجال. فالرصيد الواحاتي يعرف تدهورا متزايدا بسبب الاستغلال المفرط واللاعقلاني لمصادر المياه والتي تعاني نذرة طبيعية بسبب توالي مواسم الجفاف , علاوة على تنامي كفاءة الدينامية الريحية وبالتالي تفاقم ظاهرة التصحر بمختلف تجلياتها من زحف الرمال، تملح تدهور القدرة الإنتاجية للتربة. كما تعرف الأحواض الواحية سنويا إمتطاحات قوية تؤثر على المجال والمجتمع الواحيين. في مقابل رزنامة المخاطر هاته تتوفر المجالات الواحية على عدد من المؤهلات الطبيعية والبشرية والتراثية الكفيلة في حالة تعبئتها وتثمينها بخلق دينامية تنموية تنهض بالواحات وتحمي توازناتها الهشة. في هذا الصدد، يكتسي الحفاظ على الخدمات الإيكولوجية والاقتصادية والاجتماعية والثقافية التي يقدمها المجال الواحاتي لساكنته ولمجموع التراب الوطني أهمية قصوى باعتباره حاجزا طبيعيا أمام ظاهرة التصحر، وحاضنا لتنوع بيولوجي مهم وعنصرا من عناصر توازن المناخ، ومصدرا لمنتجات زراعية ذات خصوصية مجالية، بالإضافة إلى احتضانه لمنظومة قيمية غنية ومتنوعة . من هنا تنبثق أولوية تحديد مدخلات ومخرجات التنمية الواحية لتفادي تضارب وعدم تكامل التدخلات العمومية والتأسيس لمقاربة مندمجة تحيط بإشكالات هذه المجالات الغنية والهشة.Moroccan oasis has been living for decades in a worrying situation that indicates the accelerating consequences of the various environmental risks that threaten this area. In addition to the growing efficiency of wind dynamics, the phenomenon of desertification, with its various manifestations of sand creep, is exacerbated...The oasis basins are also known annually as strong floods that affect the oasis and the community. In exchange for these calendars, oasis domains have a number of natural, human and heritage qualifications that can be mobilized and valued by creating a dynamic of development that promotes oasis and protects their fragile balances. In this regard, the preservation of ecological, economic, social and cultural services provided by the coastal area and by the national soil as a natural barrier to désertification, an important biological diversity incubator, an element of the climate balance, and a source of agricultural products with a highly specific nature; In addition to embracing a rich and diverse value system ... Top importance. Hence, the priority of identifying the inputs and outputs of the inspired development is to avoid the inconsistency and incomplementarity of public interventions and to establish an integrated approach to the problems of these rich and fragile areas

Degradation of Acid Red 18 in an aqueous environment by TiO2/Zeolite nano photocatalyst

In this study, the TiO2 nanoparticles were supported on Y-type zeolite as a new photocatalyst and used to degrade Acid Red 18 in aqueous media. The nano photocatalyst was synthesized by coprecipitation procedure and characterized by Fourier transfer infrared (FTIR), field emission scanning electron microscopy (FE-SEM), and X-ray powder diffraction (XRD). The central composite design (CCD) was employed for experimental design. The effect of operative variables including contact time, photocatalyst dosage and pH were investigated. The ANOVA (analysis of variance) studies displays the second-order regression model and a high determination coefficient value (R2 = 0.9953, R2pred = 0.9642, R2adj = 0.9910) for the destruction of AR18 was obtained. The contour plots were applied to study the shares of each variable and their interactions on the degradation of AR18. The optimal circumstances predicted by the model were as the following: the catalyst concentration at 0.88g/L, pH at 6.5, and contact time in 125 min. In this situation, the predicted and actual dye removal were 98.5% and 96.3%, respectively. The removal of COD (chemical oxygen demand) after 125 min was 53% indicating, the notable performance of photocatalyst in mineralization of AR18

Improved δ-SPH Scheme With Automatic and Adaptive Numerical Dissipation

[Abstract] In this work we present a δ-Smoothed Particle Hydrodynamics (SPH) scheme for weakly compressible flows with automatic adaptive numerical dissipation. The resulting scheme is a meshless self-adaptive method, in which the introduced artificial dissipation is designed to increase the dissipation in zones where the flow is under-resolved by the numerical scheme, and to decrease it where dissipation is not required. The accuracy and robustness of the proposed methodology is tested by solving several numerical examples. Using the proposed scheme, we are able to recover the theoretical decay of kinetic energy, even where the flow is under-resolved in very coarse particle discretizations. Moreover, compared with the original δ-SPH scheme, the proposed method reduces the number of problem-dependent parameters.This research was funded by the Ministerio de Ciencia, Innovación y Universidades of the Spanish Government, grant number #RTI2018-093366-B-I00, by the Consellería de Educación e Ordenación Universitaria of the Xunta de Galicia (grant number #ED431C 2018/41). Xesús Nogueira has also been funded by the Xunta de Galicia through the program Axudas para a mellora, creación, recoñecemento e estruturación de agrupacións estratéxicas do Sistema Universitario de Galicia (grant number # ED431E 2018/11)Xunta de Galicia; ED431C 2018/41Xunta de Galicia; ED431E 2018/1

Cholest-5-en-3β-yl N-phenyl­carbamate

In the title compound, C34H51NO2, the dihedral angle between the planes of the phenyl ring and the carbonyl group is 9.30 (2)°. No significant inter­molecular inter­actions are observed in the crystal structure. The C5H11 fragment is disordered over two positions with site occupancies of 0.611 (6) and 0.389 (6)

A WCSPH Particle Shifting Strategy for Simulating Violent Free Surface Flows

ABSTRACT: first_pagesettingsOrder Article Reprints Open AccessArticle A WCSPH Particle Shifting Strategy for Simulating Violent Free Surface Flows by Abdelkader Krimi *ORCID,Mojtaba JandaghianORCID andAhmad Shakibaeinia Department of Civil, Geological and Mining Engineering, Polytechnique Montréal, 2900 Boulevard Edouard-Montpetit, Montréal, QC H3T 1J4, Canada * Author to whom correspondence should be addressed. Water 2020, 12(11), 3189; https://doi.org/10.3390/w12113189 Received: 5 October 2020 / Revised: 9 November 2020 / Accepted: 10 November 2020 / Published: 14 November 2020 (This article belongs to the Special Issue Meshless Methods for Water Dynamics and Complex Flows) Download Browse Figures Versions Notes Abstract In this work, we develop an enhanced particle shifting strategy in the framework of weakly compressibl

Optimising Subsidiary Crop Applications in Rotations (OSCAR): A Perspective for the North Africa Region

Background: For sustainable improvement of wheat-based farming systems in the North Africa, there is a need to improve plant health, soil health and fertility. One approach to achieve this is by integrating subsidiary crops (SC) as living or dead mulches or cover crops with the main crops in rotations, which will increase plant species and microbial diversity and reducing water demand in dry climates. Methods: A collaborative research project funded by EU FP 7 (Project No. 289277) was initiated in April 2012, in partnership with European Union (public research organizations and private sector small and medium enterprises of Germany, Norway, Sweden, Denmark, the Netherland, UK, Poland, Switzerland and Italy), Brazil and Morocco (INRA-Morocco and ICARDA), in order to enhance understanding and use of SC systems, develop suitable farm technologies, increase the range of SC species, and enhance understanding of impact of SC on soil ecology, biology and microbial diversity and crop pests and diseases. Results: Based on two field experiments in Morocco (Sidi AI-Aidi and Sidi Allal-Tazi), the project will assess the economic and ecological impact including legume root health and soil health, fertility and microbial diversity and compare the results with other sites in Europe. Screening of new species and genotypes will result in identification of range of potentially useful plant species for SC for the North Africa and Europe. The identified SC species will be tested for their potential as forage and for extraction of useful biochemicals. Conclusion: The results of the project as a whole will be of use for and improve sustainability in low-input, organic, and conventional farming systems in the North Africa, Latin America and Europe

Towards identification of novel legume species of potential interest as cover crops and living mulches for the North Africa region.

Subsidiary crops (SC) grown either as cover crops (CC) preceding or following the main crops, or as living mulches (LM) together with the main crops can deliver multiple ecological services within farming systems. These include increasing the duration of soil cover in the rotation, increasing plant and microbial diversity, improving plant health, soil health and fertility, minimizing the use of tillage and agrochemicals, enhancing biological N fixation and soil C content, and reducing water demand in dry climates. However, species available for growing as SC for dry areas are limited. To identify species of potential interest to CC and LM, we screened 197 accessions from the ICARDA genebank, belonging to 142 species/sub-species at Rabat, Morocco in one square meter plots. The preliminary assessments based on visual observations enabled us to identify: (1) 21 accessions belonging to Medicago and Trifolium species with prostrate growth habit, early maturity and senescence, determinate growth cycle and good potential for seed production, as potentially suitable for LM; and (2) 28 accessions belonging to Vicia, Lathyrus, Medicago and Trifolium species with high biomass and competitive ability, and also good potential for seed production, as potentially suitable for CC or green manure crops. Further evaluations in replicated trials are in progress. The selected accessions have been planted in the field during autumn 2013 at Sidi El Aidi