The primary goal of the research presented in this thesis has been to establish the yeast Yarrowia lipolytica as a model genetic system for the study of peroxisome biogenesis. To facilitate this, three steps were necessary. First, mutant strains of Y. lipolytica that manifested peroxisomal defects were generated; second, a genomic DNA library was created to rescue the mutants and, hence, clone the gene(s) involved; and third, the parameters governing high efficiency DNA transformation of Y. lipolytica were defined to make complementation of mutants with the genomic library feasible. This work culminated in the cloning, sequencing and characterization of a gene, dubbed PAY 4, that is required for peroxisomal assembly in Y. lipolytica. Two of the mutant strains of Y. lipolytica isolated, ole 2 and ole 4, were identified as peroxisome assembly mutants as they; (i) grew in acetate medium but failed to grow on oleic acid medium, and thus were peroxisomal as opposed to mitochondrial mutants; (ii) lacked recognizable peroxisomal structures when observed by immunofluorescence using a polyclonal serum that recognized a number of peroxisomal proteins and; (iii) had several peroxisomal enzyme activities localized to the cytosol, i.e. they manifested mistargeting of otherwise lumenal peroxisomal proteins. These were complemented with a genomic library, which represented at least 19 000 independent recombinants (insert size ~5-7 kilobases) cloned into a vector (piNA445) capable of autonomous replication in Y. lipolytica. Estimations of the size of the Y. lipolytica genome indicate that probability of this library containing a given portion of the genome is .999. To utilize the library effectively, an electro-poration protocol was developed that could transform Y. lipolytica at high efficiency (>5·10^4 transformants·μg-^1 of DNA). Using these resources, the gene complementing the ole 4 mutation was cloned and sequenced. It encodes Pay4p, a protein of ~112 kDa, containing two putative ATPase modules. Preliminary studies indicate that expression of Pay4p is induced slightly by growth on oleic acid. / Thesis / Master of Science (MSc)

Co-translational targeting of secretory and integral membrane proteins to the endoplasmic reticulum (ER) requires two key mediators, the signal recognition particle (SRP) and its receptor. The SRP receptor is composed of two tightly associated subunits termed SRα and SRβ. Very little is known about the mechanism of membrane assembly of these two subunits of the SRP receptor. Therefore, it is the aim of this thesis to study the interactions between SRα and SRβ on the ER membrane as well as the role of SRα and SRβ in membrane assembly of functional SRP receptor. Unlike typical endoplasmic reticulum (ER) integral membrane proteins, both subunits of the SRP receptor were extracted from the ER membrane with 0.08% deoxycholate; 0.2M Tris pH 9.0. Nevertheless, SRβ could be targeted to the ER only when the SRP dependent pathway of translocation was functional, similar to other integral membrane proteins of the ER. Urea resistant anchoring of SRa on the ER membrane was sensitive to limited digestion of the membranes with trypsin (Andrews eta/., 1989). However, anchoring of SRα was restored by incorporating exogenous SRβ into trypsin treated membranes, confirming that one function of SRβ is anchoring of SRα. Consistent with this is the observation that, SRβ could be immunoprecipitated in a complex with SRα but not with SRα mutants containing deletions in the anchoring domain. Finally, an antiserum to the GTP binding domain of SRβ inhibited translocation of the secretory protein preprolactin suggesting that SRβ also has a direct role in translocation. / Thesis / Master of Science (MSc)

The thesis is concerning rotator assembly at Indexator. A need to increase production has been seen and it can be done by implementing an optimized assembly process. In addition to the assembly process a new design on workstations and new test equipment is needed.The study resulted into three assembly process proposals. The processes were balanced, layouts were produced and Plant simulation was utilized to produce simulation models. Each proposal were analyzed based on cost, performance, ease of implementation, flexibility and worker condition. This resulted in a stationary assembly process being most promising and a 3D simulation model was produced for visualization and better understanding. The stationary assembly process has a capacity for 90 rotators per day, while reducing the amount of workers by one.The layout of the workstations was done based on the assembly process layout and further developed to make the work cell lean and ergonomic. It resulted in three workstations to perform the assembly. The test bench was developed by creating target specifications, establish a test procedure and decide components for the test bench layout. The finished test bench can measure dynamic torque, count particles to ensure cleanliness and is able to run the test unattended. / Examensarbetet handlar om montering av rotatorer på Indexator. Målet är att ta fram en optimerad monteringsprocess som kan implementeras i Indexators fabrik utan svårigheter. Den nya monteringsprocessen kommer kräva en ny design på arbetsstationerna och nya testbänkar.Fyra koncept på monteringsprocessen togs fram, baserat på monteringens behov och målsättning. Efter utvärdering så modifierades de fyra koncepten till tre förslag på monteringsprocesser. Processerna balancerades, layouter utvecklades och simuleringsmodeller producerades för varje process. Varje förslag analyserades baserat på kostnad, prestanda, implementation,flexibilitet och arbetar-förhållande. Resultatet blev en stationär monteringsprocess och en 3Dsimulering gjordes för visualisering och förståelse. Den stationära monteringsprocessen har en kapacitet på 90 rotatorer per dag och reducerar behovet av montörer.Layouten för monteringsstationerna baseras på processens layout och har modifierats för ergonomiska aspekter. Inom monteringsstationerna så utvecklades layouten för att minimera antalet onödiga rörelser för montören. Testriggens design utvecklades genom att analysera de behov som fanns, skapa en kravspecifikation samt utvärdera och besluta om testprocedur, upplägg för testrigg och dess ingående komponenter. Testriggen uppfyller målsättningen som är att kunna mäta dynamiskt vridmoment, räkna partiklar för att säkerställa renhet i rotatorn och kunna utföra testningen självgående för att frigöra montören under testprogrammet.

The procedure of joining flexible or nonrigid parts using applied loads is called compliant assembly, and it is widely used in automotive, aerospace, electronics, and appliance manufacturing. Uncontrolled assembly processes may produce geometric errors that can exceed design tolerances and induce an increment of elastic energy in the structure due to the accumulation of internal stresses. This condition might create unexpected deformations and residual stress distributions across the structure that compromise product functionality. This thesis presents a method based on nonlinear Finite Element Analysis (FEA), metamodelling, and optimization techniques to provide accurate and on-time shimming strategies to support the definition of optimum assembly strategies. An example of the method on a typical aerospace wing box structure is demonstrated in the present study. The delivered outputs intend to support the production line by anticipating the response of the structure under a specific assembly condition and presenting alternative assembly strategies that can be applied to address eventual predicted issues on product requirements. / Graduate

Most of the seafloor is soft sediment, so hard substrata are isolated and island-like. In this dissertation, I explore how species distribution patterns on isolated marine hard substrata resemble terrestrial island communities, drawing on classical island biogeography theory and assembly rules, and describe how benthic invertebrate communities assemble in these island-like habitats. Higher species richness occurred on larger substrata (dropstones and shipwrecks), paralleling terrestrial island communities. However, while larger islands have greater habitat diversity and primary productivity, marine hard substrata are simpler habitats. Greater elevation in the benthic boundary layer may expose fauna to faster current, higher food supply and larval flux. Substrata located closer together had more similar communities, another pattern that resembles terrestrial islands. Dropstone fauna had a clumped distribution, indicating that larvae may disperse among substrata located close together, resulting in similar communities. In Svalbard fjords, benthic megafaunal communities were significantly different between Arctic- and Atlantic-influenced fjords. Depth and temperature had the greatest influence, with the highest diversity occurring in cold Rijpfjorden and on the north Svalbard shelf. Recruitment in Svalbard fjords was spatially and temporally variable, with lower recruitment in Rijpfjorden than in Atlantic-influenced fjords and lower recruitment at greater depth. Most of the recruits in Svalbard fjords were fast-growing, poor-competitive opportunists. On shipwrecks, communities showed two mechanisms of colonization: mobile fauna with long-dispersing planktotrophic larvae, and encrusting fauna with lecithotrophic larvae. Encrusting species reproduce asexually to cover the wreck surface, and philopatry may build up dense populations, leading to uneven communities. On terrestrial islands, non-random co-occurrence is attributed to interspecific competition, but for marine substrata, there may not be a relationship. Fauna were distributed randomly on settlement plates in Svalbard fjords, even when interspecific competition was observed. On dropstones, some morphotypes co-occurred non-randomly in the absence of overgrowth competition. Non-random co-occurrence on isolated marine hard substrata may be a result of restricted larval dispersal (for pairs co-occurring less than by chance) or epibiontism (for pairs co-occurring more often than by chance). While species distribution patterns on island-like marine hard substrata resemble terrestrial islands, the mechanisms are not necessarily the same.

The application of augmented reality (AR) technology for assembly guidance is a novel approach in the traditional manufacturing domain. In this paper, we propose an AR approach for assembly guidance using a virtual interactive tool that is intuitive and easy to use. The virtual interactive tool, termed the Virtual Interaction Panel (VirIP), involves two tasks: the design of the VirIPs and the real-time tracking of an interaction pen using a Restricted Coulomb Energy (RCE) neural network. The VirIP includes virtual buttons, which have meaningful assembly information that can be activated by an interaction pen during the assembly process. A visual assembly tree structure (VATS) is used for information management and assembly instructions retrieval in this AR environment. VATS is a hierarchical tree structure that can be easily maintained via a visual interface. This paper describes a typical scenario for assembly guidance using VirIP and VATS. The main characteristic of the proposed AR system is the intuitive way in which an assembly operator can easily step through a pre-defined assembly plan/sequence without the need of any sensor schemes or markers attached on the assembly components. / Singapore-MIT Alliance (SMA)

Thesis(M.S.)--Auburn University, 2005. / Abstract. Includes bibliographic references.

Thesis (Ph. D.)--University of California, Santa Cruz, 1999. / Includes bibliographical references (leaves 46-48).

Denna rapport dokumenterar ett projekt som ett examensarbete på högskoleingenjörsprogrammet inom innovationsteknik och design vid Karlstads universitet. Projektet utfördes på uppdrag av Nokalux med målet att automatisera monteringen av en belysningsarmatur. I sin fabrik i Töcksfors tillverkar Nokalux belysningsarmaturer för industriellt och privat bruk vilka säljs runt om i Norden. En av deras armaturer monteras automatiskt i en maskinlinje bestående av tre robotceller och nu vill de införa automatisk montering av ytterligare en armatur, Basic 23. Problemformuleringen för detta projekt landade i två frågor. Hur kan Basic 23 monteras per automation med Nokalux automationscell? Samt hur kan Basic 23 anpassas för automatiserad montering? Projektet påbörjades med en förstudie där information om produkten och den automationscell som Nokalux har samlades in. Under litteraturstudier hittades metoden DFA2 vilken varit en central metod i projektets arbete. DFA2 är en metod som används för att förbättra en produkts möjlighet att monteras per automatik. Med metoden DFA2 utvärderades hela Basic 23 på flera nivåer vilket resulterade i att olika problem med produkten identifierades. Utifrån analysen kunde olika förbättringsförslag genereras som ämnar att göra produkten mer anpassad för automatisk montering i Nokalux automationscell. Därefter valdes ett antal moduler av Basic 23, som lämpades bäst för automatisk montering ut för att optimeras. Några av de förbättringsförslagen som genererats infördes och modulerna anpassades med hjälp av DFA2 för att bli så lämpliga som möjligt för automatisk montering. Slutligen skapades en ny monteringsföljd för Basic 23 där de två modulerna monteras i automationscellen. Genom de förbättringsförslagen som infördes kunde antalet ingående detaljer i produkten minskas och den nya monteringsföljden visar en minskning av den manuella arbetstiden som behövs för att montera en armatur.

Over 70% of final product costs are determined by initial product design. Hence, to depict a capable and reliable part design is important during the part conceptual design phase. Case-Based Reasoning (CBR), based on analogical reasoning, is a problem solving methodology. This paper proposes the CBR architecture applied to assembly part design for effectively managing previous design experience and evaluating assemblability and manufacturability of assembly part design. The results can provide a useful reference for novices to reuse and revise previous experience and experienced designers to impart their expertise through CBR methodology.