We give an explicit description of the Loday assembly map on homotopy groups when restricted to a subgroup coming from the Atiyah-Hirzebruch spectral sequence. This proves and generalises a formula about the Loday assembly map on the first homotopy group that originally appeared in work of Waldhausen. Furthermore, we show that the Loday assembly map is injective on the second homotopy groups for a large class of integral group rings. Finally, we show that our methods can be used to compute the universal assembly map on homotopy.

This is a bachelor thesis which handles a balancing problem in a manual assembly line for mixed models. Many product variations that are assembled in an assembly line have different cycle times in each operation in the process. The products that are assembled in the line have also large variations in their lead times. This leads to large balancing losses leading to reduced productivity and efficiency. Many balancing losses occur due to the inefficient time that one of the products causes. Other balancing losses occur due to bottlenecks that occur in some operations. The purpose of this study is to investigate the balancing losses in a manual assembly line with mixed models. The goal is to develop a proposal for a balanced layout, as well as to minimize balancing losses and waste and maximize productivity as much as possible. Two research questions have been developed as guidelines for the study: RQ1: What factors can lead to balancing losses in a mixed-model assembly line? RQ2: How can a mixed-model assembly line be balanced without leading to other types of losses? The study is a case study that looks for problems in one case company. It is based on a literature study and the collection of real-world data, which has been collected at the case company by observations, interviews and documents that include data about production times and balancing reports.  A proposal on how balancing losses can be reduced in the best possible way has been developed. The inefficient time has been reduced and the assembly line has become more efficient and productive. With help of this improvement proposal, other types of losses could be avoided, such as losses of human resources and financial resources. This study aimed to reduce the balancing losses that one product causes in the assembly line. No rebalancing of the other products was done, but other products were considered so that the balancing of the product does not lead to extra imbalance on the other products in the line. It was important for the fall company to be able to implement a solution that does not lead to a lot of other losses. Based on the three solutions proposed, this solution was the most suitable for what the company wants. A new layout for the product’s stations has been proposed. With this layout, efficiency will increase, and downtime will decrease, thus increasing productivity. Proposal three shows that it is possible to balance a mixed-model assembly line, by terminating a product and removing it earlier from the assembly line.   Keywords: Line balancing, manual assembly, balancing loss, mixed products, mixed-model assembly / Det här är ett examensarbete på grundnivå, som behandlar ett balanseringsproblem i en manuell monteringslinje för mixade modeller. Det monteras många produktkonfigurationer som har olika cykeltider i varje station i processen. Produkterna som monteras i linan har även stora variationer i deras ledtider. Detta medför stora balanseringsförluster som leder till minskad produktivitet och effektivitet. Många balanseringsförluster uppstår på grund av den ineffektiva tiden som en av produkterna orsakar. Andra balanseringsförluster uppstår på grund av flaskhalsar som förekommer i vissa stationer.  Syftet med denna studie är att undersöka balansringsförlusterna i en manuell monteringslinje med mixade modeller. Målet är att ta fram ett förslag på en balanserad layout, samt att minimera balanseringsförlusterna och slöseri och maximera produktiviteten så mycket som möjligt.   Två forskningsfrågor har tagits fram som riktlinjer för studien: F1: Vilka faktorer kan leda till balanseringsförluster i en mixad-modellmonteringslinje?  F2: Hur kan en mixad-modellmonteringslina balanseras utan att leda till andra typer av förluster? Studien är en fallstudie som undersöker problem hos ett fallföretag. Studien är baserad på en initial litteraturstudie och insamlad data, som har samlats in från fallföretaget via observationer, intervjuer samt dokument med data om produktionstider och balansrapporter.  Ett förslag på hur balanseringsförlusterna kan minskas på bästa möjliga sätt har tagits fram. Den ineffektiva tiden har minskats och monteringslinan har blivit effektivare och produktivare. Med hjälp av det här förbättringsförslaget, kunde andra typer av förluster undvikas, som exempelvis förluster av mänskliga resurser och ekonomiska resurser.   Denna studie är gjord för att minska balanseringsförlusterna som en av produkterna orsakar i monteringslinjen. Ingen ombalansering på de andra produkterna gjordes, men det togs hänsyn till andra produkter så att balanseringen av den produkten inte leder till extra obalans på de andra produkter i linan. Det var viktigt för fallföretaget att kunna implementera en lösning som inte leder till massa andra förluster. Utifrån de tre lösningarna som föreslagits var denna lösning den mest lämplig för vad företaget önskar sig. En ny layout på produktens stationer har tagits fram. Med denna layout kommer effektiviteten att öka och dötiden minska, och därmed ökas produktiviteten. Förslag tre visar sig att det är möjligt att kunna balansera en mixad-modellmonteringslina, genom att avsluta en produkt och ta ut den tidigare ur monteringslinan.   Nyckelord: Line balancing, manuell montering, balanseringsförluster, mixed products, mixed-model assembly line.

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No description available.

Doctor of Philosophy / Department of Chemistry / Daniel A. Higgins / This doctoral thesis covers the synthesis, preparation, and characterization of a series of four perylene diimide derivatives, and the nanofibrous composite materials formed by these perylene diimides when complexed with oppositely charged polyelectrolytes. The perylene diimides include a symmetric dication (TAPDI2+), a symmetric dianion (PDISO32-), and two singly charged asymmetric varieties (C11OPDI+ and C7OPDI+) that contain a hydrophilic head group and hydrophobic ether tail. For all studies presented in the following chapters, poly(acrylate) (PA-) or poly(diallyldimethylammonium) chloride (PDDA+) are used as the polyelectrolytes (PEs). The patterned deposition of sheer aligned, nanofibrous material within a fluidic device is conclusively demonstrated. Thin films of the nanofibrous composite are prepared from aqueous solutions of the semiconducting perylene diimides and oppositely charged polyelectrolyte precursors. By sequentially exposing a clean glass substrate to the cationic and anionic precursor solutions, a thin film of composite material is deposited in a layer-by-layer fashion. By utilizing electrostatic self-assembly (ESA) and layer-by-layer (LbL) procedures, precise control of film thickness and optical density are obtained. The effect of perylene diimide structure and charge on resultant composite film morphology is explored. Through spectroscopic and microscopic studies of bulk perylene diimide solutions and composite thin films, it was determined that the formation of these fibrous materials is dependent on the aggregation of the PDI within the precursor solutions. The molecular orientation of the perylene diimide within the composite nanofiber was determined to be perpendicular to the fiber long axis. For the special case of C7OPDI+/PA- composite, flow induced fiber alignment was observed for both dip coated and flow coated samples. The influence of solution flow profile, PE molecular weight (MW), and PDI structure on deposition efficiency, macroscopic and microscopic morphology, and the potential for nanofiber alignment are investigated. Film formation mechanisms involving two unique routes are also presented.

Centrioles are conserved microtubule-based structures that are required for the formation of two important cellular organelles, centrosomes and cilia. Centrosomes form the poles of the mitotic spindle and consist of a pair of centrioles surrounded by a matrix of pericentriolar material (PCM) that has the ability to nucleate and organise microtubules. Centrosome defects are implicated into a variety of human diseases including cancer, microcephaly, and ciliopathies. Therefore it is of great interest to understand the mechanisms that lead to centrosome formation and the consequences that centrosome defects have in cells. I have analysed the roles of several centrosomal proteins in centrosome assembly in Drosophila. My results indicate that Sak/PLK4 is only required for the initial step of centriole duplication, but has no further role in recruitment of PCM. I show that two proteins important for PCM recruitment, Asterless (Asl) and Spd-2, are preferentially phosphorylated when they are integrated into the centrosome and I identified these phosphorylation sites using a phosphoproteomic screen. A phosphorylation site in Asl is specifically phosphorylated in mitosis, and the phosphorylation state of Spd-2 regulates its maintenance at the centrosome, suggesting that phosphorylation of PCM proteins is an important mechanism to ensure PCM assembly specifically at the centrosome and in mitosis. I have performed a global transcriptional analysis of flies lacking centrosomes or having extra centrosomes to investigate the effects of centrosomal defects on a cellular level. Surprisingly, my results indicate that centrosome defects per se do not dramatically alter cellular physiology. Finally, I demonstrate that in the absence of centrioles acentrosomal microtubule-organising centres (aMTOCs) are formed in an Asl- and Cnn-dependent fashion, and I show that these aMTOCs can contribute to spindle focusing in acentrosomal cells.

No description available.

This paper describes a new application for servopneumatic drives. In a battery module for automotive applications the pouch cells are clamped between frames. During the assembly the frames needs to be clamped permanently. So a clamping system comprising two drives was developed, which moves four clamp fingers each alternating. In the first chapter the application is described in detail. The second chapter includes a comparison of servoelectric and servopneumatic drives for this application with respect to energy consumption, installation space and purchase cost. The developed clamping unit is described in chapter three as well as a verification of the influence of the preload force on the straightness of the stack. At the end of this paper the conclusions are summed up.

Ανάπτυξη αναπτυξιακού συστήματος για τους μικροελεγκτες MCS-51. / Design and development of a development system for MCS-51 controllers.

Self-assembly is a process of non-intrusive transformation of a system from a disordered to an ordered state. For engineering purposes, self-assembly of microscopic objects can benefit significantly from macroscopic guidance and control. This dissertation is concerned with controlling self-assembly in binary monolayers of electrically charged particles that follow basic laws of statistical mechanics. First, a simple macroscopic model is used to determine an optimal thermal control for self-assembly. The model assumes that a single rate-controlling mechanism is responsible for the formation of spatially ordered structures and that its rate follows an Arrhenius form. The model parameters are obtained using molecular dynamics simulations. The optimal control is derived in an analytical form using classical optimization methods. Two major lessons were learned from that work: (i) isothermal control was almost as effective as optimal time-dependent thermal control, and (ii) neither electrostatic interactions nor thermal control were particularly effective in eliminating voids formed during self-assembly. Accordingly, at the next stage, the focus is on temperature-pressure control under isothermal-isobaric conditions. In identifying optimal temperature and pressure conditions, several assumptions, that allow one to relate the optimal conditions to the phase diagram, are proposed. Instead of verifying the individual assumptions, the entire approach is verified using molecular dynamics simulations. It is estimated that under optimal isothermal-isobaric conditions the rate of self-assembly is about five time faster than that under optimal temperature control conditions. It is argued that the proposed approach of relating optimal conditions to the phase diagram is applicable to other systems. Further, the work reveals numerous and useful parallels between self-assembly and crystal physics, which are important to exploit for developing robust engineering self-assembly processes. / text