18 research outputs found

    Toleranskostnader vid diskret tillverkning - Avseende ytor, dimensioner, form och egenskapskrav

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    Toleransproblematiken Ă€r ett omtalat Ă€mne inom tillverkningsindustrin, dĂ€r det Ă€r allmĂ€nt kĂ€nt att snĂ€va toleranser medför höga kassationer och kostnader. Konstruktörer och utvecklare anvĂ€nder sig av ett traditionsbaserat tĂ€nk vid toleranssĂ€ttning, dĂ„ kunskapen kring omrĂ„det Ă€r lĂ„gt och dĂ„ kunskapen kring kostnader kopplat till olika toleransintervall saknas. Detta medför att onödigt hĂ„rda krav stĂ€lls pĂ„ bearbetningen, och pĂ„ sĂ„ sĂ€tt ökade kassationer och kostnader för produktionen. Ökad kunskap kring problemomrĂ„det kan bidra till stora konkurrensfördelar och kostnadsbesparingar. Syftet med examensarbetet var att kartlĂ€gga problemomrĂ„det avseende toleranser och ytkrav. Fokus lĂ„g pĂ„ att identifiera faktorer, kopplat till processen, som industrin an-sĂ„g sig ha problem med vid tillverkning av detaljerna. Samt Ă€ven att analysera kost-naderna och kostnadsparametrarna kopplat till toleranser och slutligen hur tolerans-sĂ€ttning sker i industrin. Examensarbetet utfördes i samarbete med tvĂ„ tillverkningsföretag. Metoderna som anvĂ€nts, för att komma fram till resultatet Ă€r; intervjuer med konstruktörer, produktionsutvecklare/produktionschefer, kvalitetspersonal och operatörer, samt genom data-insamling. Det insamlade materialet analyserades genom granskning av materialet genom faktorgruppernas indelning och med hjĂ€lp av MathCad. En del av resultatet frĂ„n studien Ă€r en övergripande beskrivning av vad industrin anser att problemen inom toleransomrĂ„det Ă€r. Beskrivningen talar Ă€ven om att det Ă€r mĂ„nga faktorer som pĂ„verkar toleranserna. Det krĂ€vs fallstudier med tester, för att avgöra hur stor en enskild faktor pĂ„verkar toleranserna. Resultatet visar Ă€ven att företagen har generellt dĂ„lig insikt i sina faktiska produktionskostnader, produktionsparametrar, och att ökade kunskaper kring detta kan leda till stora besparingar. Det har Ă€ven via de genomförda granskningarna visat sig att företagen anvĂ€nder ett traditionstĂ€nk vid toleranssĂ€ttning. Detta medför att onödigt hĂ„rda krav stĂ€lls pĂ„ bearbetningen, och att deras insikt i kostnaderna rörande de olika toleransintervallerna Ă€r vag.The area of concern is an up to date subject within the manufacturing industry, were it is well known that high tolerance-requirements contributes to increased costs and scraps. Improved knowledge regarding the area of concern may be an asset within the market of competition, and will also reduce the costs. The purpose of the master thesis was to describe the area of concern regarding toler-ances and surface requirements. The main concern was to identify the factors related to the process, that the industry considered to be problems during the manufacturing. The aim was also to analyse the costs and the costs element specifically related to the tolerances, and finally how the company are working with standard measures. The result from the study is a general description of the industries concerns regarding tolerances. The description also outlines the many factors that affect the tolerances, and that case studies will be necessary to settle how much a separate factor will affect the tolerance. It has also shown that the companies lack knowledge about their actual production costs, production elements and that enhanced knowledge regarding the subject will contribute to savings. The analyse also displayed that the companies use a traditional way of thinking when setting the standard of tolerances. This contributes to unnecessary high demands on the process and also leads to the lack of awareness regarding the expenses for different tolerance intervals

    Cooking quality in potatoes depending on cultivation measures and specific gravity

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    Matpotatis Ă€r en livsmedelsrĂ„vara dĂ€r den specifika vikten Ă€r direkt avgörande för kokegenskaperna och kvaliteten. PĂ„ grund av varierande kokkvalitet hos matpotatis blev vi kontaktade av SkĂ„nes Potatisodlarförening för att göra en dokumentation om hur odlarna bedriver sina matpotatisodlingar och för att försöka hitta ett samband mellan odlingsĂ„tgĂ€rder och kokkvalitet i matpotatisen. Genom styrd bevattning, val av gödselmĂ€ngder och jordmĂ„n Ă€r teorin att man kan pĂ„verka den specifika viktens utveckling under vĂ€xtperioden och dĂ€rmed kokkvaliteten. I projektet deltog 12 odlare, utspridda i hela SkĂ„ne, och en odlare i södra Halland. Projektet inleddes med att Ă„ka ut till alla odlarna och utföra en skriftlig dokumentation om hur odlingarna bedrivs och vilka strategier som odlarna hade inför sĂ€songen. Under odlingssĂ€songen besöktes varje odlare en gĂ„ng per vecka och prov togs ut för att bestĂ€mma den specifika vikten hos potatisen frĂ„n olika delar av fĂ€lten. MĂ„let var att följa den specifika viktens utveckling under olika förhĂ„llanden, sĂ„som nederbörd, bevattning, gödsling och jordmĂ„ner. Under odlingssĂ€songen bestĂ€mdes matpotatisens specifika vikt genom ”sjunkprovsmetoden”. I denna metod vĂ€gs en exakt mĂ€ngd potatis upp och sedan sĂ€nker man ner potatisen i ett vattenbad. DĂ€refter mĂ€ter man hur mycket vatten som potatisen trycker undan och fĂ„r genom avlĂ€sning i en översĂ€ttningstabell reda pĂ„ den specifika vikten. BĂ„de i samband med blastdödning och upptagning lĂ€mnades prover till SMAK för bestĂ€mning av specifik vikt och kokanalyser. För potatissorten Sava som studerades hos 5 odlare fanns större möjligheter att dra slutsatser om riktvĂ€rdet för den specifika vikten sĂ„ att bra kokegenskaper uppnĂ„s. Studien tyder pĂ„ att 1075 för den specifika vikten hos Sava Ă€r ett rimligt mĂ„l att satsa pĂ„ för att fĂ„ bra egenskaper och rĂ€tt kokkvalitet. Efter genomfört arbete har vi inte kunnat identifiera nĂ„gra speciella odlingsĂ„tgĂ€rder som vi med sĂ€kerhet kan sĂ€ga pĂ„verka kokresultatet p.g.a. studiens översiktliga upplĂ€gg. DĂ€remot tror vi att mĂ„nga variabler pĂ„verkar resultatet, bland annat vatten- och kvĂ€vetillgĂ„ngen, hur blastdödningen utförs samt hur snabbt potatisen slutar vĂ€xa efter att blastdödningen utförts och om potatisen börjar vĂ€xa om igen efter blastdödningen. Det finns en viss antydan till att tyngre jord leder till en högre specifik vikt, men detta Ă€r inte helt entydigt.Potatoes are a raw material where the specific gravity content is crucial for the cooking quality. We were contacted because of the variation in cooking qualities by the “SkĂ„nes Potato Growers Union” to perform a survey on how potato is grown and to try and find a relation between farming methods and cooking qualities. The theory is that thru controlled irrigation, the choice of fertilizers and soil structure, the cooking quality and the specific gravity content, development during the growing season can be affected. There are 12 growers participating in this project, scattered all over SkĂ„ne and one in southern Halland. We started the project by visiting all the farmers to perform a written documentation about how the farmers grow their potatoes and which strategies they had before the growth season. During the growing season each field was visited every week and samples were taken from different parts of the field for determination of the specific gravity. The aim was to follow the development of the specific gravity content during different conditions such as rainfall, irrigation, fertilization and soil structure. During the growth season the specific gravity content is determined by the potato hydrometer, a certain weight of potatoes is measured and then lowered into a bucket of water. The amount of water that is pushed away by the potatoes is measured and by using a translation table the specific gravity content can be determined. One sample is taken at the same time as haulm killing and one sample is taken at the time of harvesting and both were sent to SMAK for cooking analysis. 5 growers had the potato variety Sava and beacuse of this, the possibilities to draw more accurate results on what specific gravity recommendations that are needed to obtain good cooking quality, were larger. The study indicates that the aim of 1075 for specific gravity of Sava, is a resonable aim to obtain the correct cooking quality. We have not been able to idetify any specific cultivations measures after completing this study that directly affects the results, because of the overall layout of the study. On the other hand we believe that a lot of variables affects the results and the most important variables are water- and nitrogensupply. Other cultivation measures that we believe play an important role are the way haulm killing is done and how quickly the potatoes actually dies after this as well as if the potatoes starts to grow again after the defoliation. It seems like that soil with higher claycontent might lead to higher specific gravity but this is not univocally

    Hur integrerar man förÀldrarna i matematikundervisningen?

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    Syftet med detta arbete Ă€r att utforma ett material dĂ€r matematikundervisningens mĂ„l och arbetssĂ€tt tydliggörs för förĂ€ldrarna; detta för att förĂ€ldrarna ska bli mer positiva till undervisningen och dĂ€rmed pĂ„verka sina barn positivt. Vi har pĂ„ tvĂ„ skolor i södra Sverige genomfört en enkĂ€tundersökning med 49 elever i skolĂ„r 4 och deras förĂ€ldrar. Undersökningen visar att förĂ€ldrar inte Ă€r insatta i matematikundervisningen, att de vill ha mer information om undervisningens mĂ„l och arbetssĂ€tt samt hur de kan hjĂ€lpa sina barns matematik-inlĂ€rning. Denna information vill de ha i form av brev och trĂ€ffar. Vi har utformat ett material för hur informationstrĂ€ff och –brev kan lĂ€ggas upp och vad de kan innehĂ„lla. Med detta material kan skolan tydliggöra den information som förĂ€ldrarna behöver för att bĂ€ttre kunna hjĂ€lpa sina barn med matematiken

    Makroekonomiska variablers pÄverkan pÄ Dow Jones och OMXS30

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    Syftet med studien Àr att undersöka makroekonomiska variablers effekt pÄ Dow Jones och OMXS30, med hjÀlp av en lÀmplig ekonometrisk modell. Vidare Àr syftet att analysera möjligheten för börsprognostisering och analysera om denna möjlighet Àr lika stor för Dow Jones som för OMXS30. Detta kommer att ske genom att undersöka motsvarande variabler för respektive lands aktieindex. Variablerna arbetslöshet, rÀnta och oljepris visade sig inte ha nÄgon signifikant pÄverkan pÄ varken Dow Jones eller OMXS30. Det visade sig dock att aktieindexen reagerade pÄ samma sÀtt, för respektive lands variabler

    Regulation of callose synthase activity in situ in alamethicin-permeabilized Arabidopsis and tobacco suspension cells

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    Background: The cell wall component callose is mainly synthesized at certain developmental stages and after wounding or pathogen attack. Callose synthases are membrane-bound enzymes that have been relatively well characterized in vitro using isolated membrane fractions or purified enzyme. However, little is known about their functional properties in situ, under conditions when the cell wall is intact. To allow in situ investigations of the regulation of callose synthesis, cell suspensions of Arabidopsis thaliana (Col-0), and tobacco (BY-2), were permeabilized with the channel-forming peptide alamethicin. Results: Nucleic acid-binding dyes and marker enzymes demonstrated alamethicin permeabilization of plasma membrane, mitochondria and plastids, also allowing callose synthase measurements. In the presence of alamethicin, Ca2+ addition was required for callose synthase activity, and the activity was further stimulated by Mg2+ Cells pretreated with oryzalin to destabilize the microtubules prior to alamethicin permeabilization showed significantly lower callose synthase activity as compared to non-treated cells. As judged by aniline blue staining, the callose formed was deposited both at the cell walls joining adjacent cells and at discrete punctate locations earlier described as half plasmodesmata on the outer walls. This pattern was unaffected by oryzalin pretreatment, showing a quantitative rather than a qualitative effect of polymerized tubulin on callose synthase activity. No callose was deposited unless alamethicin, Ca2+ and UDP-glucose were present. Tubulin and callose synthase were furthermore part of the same plasma membrane protein complex, as judged by two-dimensional blue native SDS-PAGE. Conclusion: Alamethicin permeabilization allowed determination of callose synthase regulation and tubulin interaction in the natural crowded cellular environment and under conditions where contacts between the cell wall, the plasma membrane and cytoskeletal macromolecules remained. The results also suggest that alamethicin permeabilization induces a defense response mimicking the natural physical separation of cells (for example when intercellulars are formed), during which plasmodesmata are transiently left open

    Cost-effectiveness of Internet-Delivered Emotion Regulation Therapy for Adolescents With Nonsuicidal Self-injury

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    Objectives: To evaluate the cost-effectiveness of internet-delivered emotion regulation individual therapy for adolescents (IERITA) with nonsuicidal self-injury disorder. Design: Secondary cost-effectiveness analyses from a randomized controlled trial of IERITA plus treatment as usual (TAU) versus TAU only. Setting: Multi-site study at three child and adolescent mental health services in Sweden. Participants: Clinically referred and self-referred adolescent participants meeting diagnostic criteria for nonsuicidal self-injury disorder (N = 166) and their parents. Recruitment took place between November 20, 2017, and April 9, 2020. Interventions: Twelve weeks of IERITA delivered adjunctive to TAU versus TAU only. Main outcomes and measures: Clinical outcomes were frequency of nonsuicidal self-injury (primary outcome) and NSSI remission, assessed by the Deliberate Self-Harm Inventory-Youth version and quality-adjusted life-years (QALYs) estimated based on participant responses on the Kid-Screen 10. Intervention, health care sector, and societal costs were assessed using the parent-rated version of the Trimbos-iMTA questionnaire for costs associated with psychiatric illness. Clinical outcomes and costs were measured before treatment, 1-month post-treatment (primary end-point), and 3-month post-treatment. Results: Adding IERITA to TAU was associated with improved clinical outcomes and increased costs at 1-month post-treatment, reducing one NSSI episode at a cost of \$2107 and achieving NSSI remission in one additional participant for \$8809. At 3-month post-treatment, IERITA was more effective in clinical outcomes and cost saving from both a societal (\$-2067) and health-care perspective (\$-425). IERITA had a 48-55% probability of being cost-effective at common QALY willingness-to-pay thresholds at 1-month post-treatment, which increased to 73-76% at the 3-month post-treatment. Conclusions: IERITA delivered adjunctive to TAU is a cost-effective treatment of nonsuicidal self-injury in youth, compared to TAU only. At the 3-month post-treatment assessment, IERITA was associated with both improved clinical outcomes and reduced costs
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