64 research outputs found
Drying and storage costs in existing grain plants
Att lagra spannmÄlen hemma pÄ gÄrden Àr nÄgot som mÄnga lantbrukare gör i hopp om att kunna sÀlja det till ett bÀttre pris senare pÄ Äret. Att sÀlja spannmÄlen senare pÄ Äret kan ge ett högre pris pÄ 0,2 kr per kg spannmÄl. Tidigare studier av Westlin., et al (2002) har visat att man kan bygga en komplett anlÀggning för under 0,2 kr per kg spannmÄl. Detta kan dÄ motivera en investering av en spannmÄlsanlÀggning hemma pÄ gÄrden. Kontakt togs med 8 stycken gÄrdar som hade investerat i en anlÀggning som inte var Àldre Àn 10 Är. Ett frÄgeformulÀr skickades ut dÀr de fick skriva in kostnaderna som vi sen rÀknade om och sammanstÀllde i tabeller.
Det vi kunde fÄ fram i vÄran undersökning Àr att mobiltork i kombination med planlager Àr det billigaste alternativet. Det gÄr att kombinera planlagring med mobiltorkning för en kostnad av 0,168 kr per kg spannmÄl. Detta Àr exklusive energiÄtgÄng för torkprocessen. Silolagring krÀver mindre arbete Àn planlager dÄ det mesta sker med skruvar. Det Àr individuellt mellan gÄrdarna och vad just de har för förutsÀttningar som styr val av tork och lagring, som i sin tur pÄverkar den slutliga kostanden.
VĂ„r slutsats:
âąMobiltork i kombination med planlager Ă€r det billigaste alternativet
âąGĂ„rdens förutsĂ€ttningar har stor inverkan pĂ„ val av system
âąStörre anlĂ€ggningar blir billigareStoring the grain at the farm is something that many farmers do, and they hope to sell the grain at a better price later on. Selling the grain later in the year can give a higher price of 0,2 kr per kg grain. Previous studies have shown that you can build a complete plant for less than 0.2 kr per kg grain. This can then justify an investment in a grain plant at the farm. We contacted 8 farms that we knew had invested in a plant, not older than 10 years. Then we sent out a questionnaire where they had to enter the costs that we later calculated and compiled in tables. What we found in our study is that the mobile dryer in combination with flatbeds is the cheapest option. It is possible to combine flatbeds with mobile drying for a cost of 0.168 kr per kg of grain. This is excluding energy usage for the drying process. Silo storage requires less work than flatbeds, since the grain are moved with augers. It is very individual between the farms and what conditions they have that control the choice of drying and storage, which in turn affects the final cost. Our conclusion:
âąMobile drying in combination with flatbeds is the cheapest option
âąThe conditions of the farm have a major impact on the choice of systems
âąLarger facilities will be cheape
Birth weight as an independent predictor of ADHD symptoms : a within-twin pair analysis
BACKGROUND: Studies have found an association between low birth weight and ADHD,
but the nature of this relation is unclear. First, it is uncertain whether birth
weight is associated with both of the ADHD dimensions, inattentiveness and
hyperactivity-impulsivity. Second, it remains uncertain whether the association
between birth weight and ADHD symptom severity is confounded by familial factors.
METHOD: Parents of all Swedish 9- and 12-year-old twins born between 1992 and
2000 were interviewed for DSM-IV inattentive and hyperactive-impulsive ADHD
symptoms by the Autism - Tics, AD/HD and other Comorbidities (A-TAC) inventory (N= 21,775 twins). Birth weight was collected prospectively through the Medical
Birth Registry. We used a within-twin pair design to control for genetic and
shared environmental factors.
RESULTS: Reduced birth weight was significantly
associated with a mean increase in total ADHD (beta = -.42; 95% CI: -.53, -.30),
inattentive (beta = -.26; 95% CI: -.33, -.19), and hyperactive-impulsive (beta =
-.16; 95% CI: -.22, -.10) symptom severity. These results imply that a change of
one kilogram of birth weight corresponded to parents rating their child nearly
one unit higher (going from "no" to "yes, to some extent" on a given symptom) on
the total ADHD scale. These associations remained within pairs of MZ and DZ
twins, and were also present when restricting the analyses to full term births.
CONCLUSIONS: There is an independent association between low birth weight and all
forms of ADHD symptoms, even after controlling for all environmental and genetic
confounds shared within twin pairs. These results indicate that fetal growth
restriction (as reflected in birth weight differences within twin pairs) and/or
the environmental factors which influence it is in the casual pathway leading to
ADHD.The Swedish Council for Working Life and Social ResearchThe Swedish Research CouncilManuscrip
Familial Liability for Eating Disorders and Suicide Attempts: Evidence From a Population Registry in Sweden
IMPORTANCE: Suicide attempts are common in individuals with eating disorders. More precise understanding of the mechanisms underlying their concomitant occurrence is needed.
OBJECTIVE: To examine the association between eating disorders and suicide attempts and whether familial risk factors contribute to the association.
DESIGN, SETTING, AND PARTICIPANTS: A Swedish birth cohort including individuals born in Sweden between January 1, 1979, and December 31, 2001, was followed up from age 6 years to December 31, 2009 (N = 2,268,786). Information was acquired from Swedish national registers. All individuals were linked to their biological full siblings, maternal half siblings, paternal half siblings, full cousins, and half cousins. Data analysis was conducted from October 5, 2014, to April 28, 2015.
MAIN OUTCOMES AND MEASURES: Eating disorders were captured by 3 variables (any eating disorder, anorexia nervosa, and bulimia nervosa) identified by any lifetime diagnoses recorded in the registers. Suicide attempts were defined as any suicide attempts, including death by suicide, recorded in the registers. We examined the association between eating disorders and death by suicide separately, but the study was underpowered to explore familial liability for this association.
RESULTS: Of 2,268,786 individuals, 15,457 females (1.40% of all females) and 991 males (0.09% of all males) had any eating disorder, 7680 females (0.70%) and 453 males (0.04%) had anorexia nervosa, and 3349 females (0.30%), and 61 males (0.01%) had bulimia nervosa. Individuals with any eating disorder had an increased risk (reported as odds ratio [95% CI]) of suicide attempts (5.28 [5.04-5.54]) and death by suicide (5.39 [4.00-7.25]). The risks were attenuated but remained significant after adjusting for comorbid major depressive disorder, anxiety disorder, and substance use disorder (suicide attempts: 1.82 [1.72-1.93]; death by suicide: 2.04 [1.49-2.80]). Similar results were found for anorexia nervosa (suicide attempts: crude, 4.42 [4.12-4.74] vs adjusted, 1.70 [1.56-1.85]; death by suicide: crude, 6.46 [4.38-9.54] vs adjusted, 2.67 [1.78-4.01]) and bulimia nervosa (suicide attempts: crude, 6.26 [5.73-6.85] vs adjusted, 1.88 [1.68-2.10]; death by suicide: crude, 4.45 [2.44-8.11] vs adjusted, 1.48 [0.81-2.72]). Individuals (index) who had a full sibling with any eating disorder had an increased risk of suicide attempts (1.41 [1.29-1.53]). The risk was attenuated for any eating disorder in more-distant relatives (maternal half siblings, 1.10 [0.90-1.34]; paternal half siblings, 1.21 [0.98-1.49]; full cousins, 1.11 [1.06-1.18]; half cousins, 0.90 [0.78-1.03]). This familial pattern remained stable after adjusting for the index individuals' eating disorders. Similar patterns were found for anorexia nervosa and bulimia nervosa.
CONCLUSIONS AND RELEVANCE: These results suggest an increased risk of suicide attempts in individuals with lifetime eating disorders and their relatives. The pattern of familial coaggregation suggests familial liability for the association between eating disorders and suicide. Psychiatric comorbidities partially explain this association, suggesting particularly high-risk presentations
Shared familial risk factors between attention-deficit/hyperactivity disorder and overweight/obesity : a population based familial co-aggregation study in Sweden
BACKGROUND: Despite meta-analytic evidence for the association between
attention-deficit/hyperactivity disorder (ADHD) and overweight/obesity, the
mechanisms underlying the association are yet to be fully understood. METHODS: By
linking multiple Swedish national and regional registers, we identified 472,735
index males born during 1973-1992, with information on body weight and height
directly measured before they were conscripted for military service. We further
identified 523,237 full siblings born during 1973-2002 for the index males. All
individuals were followed up from their third birthday to December 31, 2009 for
ADHD diagnosis. Logistic regression models were used to estimate the association
between overweight/obesity in index males and ADHD in their full siblings.
RESULTS: Siblings of index males with overweight/obesity had increased risk for
ADHD (overweight: OR = 1.14, 95% CI = 1.05-1.24; obesity: OR = 1.42, 95% CI =
1.24-1.63), compared with siblings of index males with normal weight. The results
were adjusted for birth year of the index male and sex of the sibling. After
further adjustment for ADHD status of the index male, the familial coaggregation
remained significant (overweight: OR = 1.13, 95% CI = 1.04-1.22; obesity: OR =
1.38, 95% CI = 1.21-1.57). The results were similar across sex of the siblings.
CONCLUSIONS: Attention-deficit/hyperactivity disorder and overweight/obesity
share familial risk factors, which are not limited to those causing
overweight/obesity through the mediation of ADHD. Future research aiming at
identifying family-wide environmental risk factors as well as common pleiotropic
genetic variants contributing to both traits is warranted.The Swedish Research CouncilThe Swedish Initiative for research on Microdata in the Social and Medical Sciences (SIMSAM)Accepte
Spin polarization of neutral excitons in quantum dots: the role of the carrier collection area
A genetically informed study of the associations between maternal age at childbearing and adverse perinatal outcomes
We examined associations of maternal age at childbearing (MAC) with gestational
age and fetal growth (i.e., birth weight adjusting for gestational age), using
two genetically informed designs (cousin and sibling comparisons) and data from
two cohorts, a population-based Swedish sample and a nationally representative
United States sample. We also conducted sensitivity analyses to test limitations
of the designs. The findings were consistent across samples and suggested that,
associations observed in the population between younger MAC and shorter
gestational age were confounded by shared familial factors; however, associations
of advanced MAC with shorter gestational age remained robust after accounting for
shared familial factors. In contrast to the gestational age findings, neither
early nor advanced MAC was associated with lower fetal growth after accounting
for shared familial factors. Given certain assumptions, these findings provide
support for a causal association between advanced MAC and shorter gestational
age. The results also suggest that there are not causal associations between
early MAC and shorter gestational age, between early MAC and lower fetal growth,
and between advanced MAC and lower fetal growth.NonePublishe
Epidemiological overview of major depressive disorder in Scandinavia using nationwide registers
Why New Hybrid Organizations are Formed: Historical Perspectives on Epistemic and Academic Drift
Optical spectroscopy of InGaAs quantum dots
The work presented in this thesis deals with optical studies of semiconductor quantum dots (QDs) in the InGaAs material system. It is shown that for self-assembled InAs QDs, the interaction with the surrounding GaAs barrier and the InAs wetting layer (WL) in particular, has a very large impact on their optical properties. The ability to control the charge state of individual QDs is demonstrated and attributed to a modulation in the carrier transport dynamics in the WL. After photo-excitation of carriers (electrons and holes) in the barrier, they will migrate in the sample and with a certain probability become captured into a QD. During this migration, the carriers can be affected by exerting them to an external magnetic field or by altering the temperature. An external magnetic field applied perpendicular to the carrier transport direction will lead to a decrease in the carrier drift velocity since their trajectories are bent, and at sufficiently high field strength become circular. In turn, this decreases the probability for the carriers to reach the QD since the probability for the carriers to get trapped in WL localizing potentials increases. An elevated temperature leads to an increased escape rate out of these potentials and again increases the flow of carriers towards the QD. These effects have significantly different strengths for electrons and holes due to the large difference in their respective masses and therefore it constitutes a way to control the supply of charges to the QD. Another effect of the different capture probabilities for electrons and holes into a QD that is explored is the ability to achieve spin polarization of the neutral exciton (X0). It has been concluded frequently in the literature that X0 cannot maintain its spin without application of an external magnetic field, due to the anisotropic electron â hole exchange interaction (AEI). In our studies, we show that at certain excitation conditions, the AEI can be by-passed since an electron is captured faster than a hole into a QD. The result is that the electron will populate the QD solely for a certain time window, before the hole is captured. During this time window and at polarized excitation, which creates spin polarized carriers, the electron can polarize the QD nuclei. In this way, a nuclear magnetic field is built up with a magnitude as high as ~ 1.5 T. This field will stabilize the X0 spin in a similar manner as an external magnetic field would. The build-up time for this nuclear field was determined to be ~ 10 ms and the polarization degree achieved for X0 is ~ 60 %. In contrast to the case of X0, the AEI is naturally cancelled for the negatively charged exciton (X-) and the positively charged exciton (X+) complexes. This is due to the fact that the electron (hole) spin is paired off in case of X- (X+). Accordingly, an even higher polarization degree (~ 73 %) is measured for the positively charged exciton. In a different study, pyramidal QD structures were employed. In contrast to fabrication of self-assembled QDs, the position of QDs can be controlled in these samples as they are grown in inverted pyramids that are etched into a substrate. After sample processing, the result is free-standing AlGaAs pyramids with InGaAs QDs inside. Due to the pyramidal shape of these structures, the light extraction is considerably enhanced which opens up possibilities to study processes un-resolvable in self-assembled QDs. This has allowed studies of Auger-like shake-up processes of holes in single QDs. Normally, after radiative recombination of X+, the QD is populated with a ground state hole. However, at recombination, a fraction of the energy can be transferred to the hole so that it afterwards occupies an excited state instead. This process is detected experimentally as a red-shifted luminescence satellite peak with an intensity on the order of ~ 1/1000 of the main X+ peak intensity. The identification of the satellite peak is based on its intensity correlation with the X+ peak, photoluminescence excitation measurements and on magnetic field measurements.Arbetet som presenteras i denna avhandling rör studier av kvantprickars optiska egenskaper. En kvantprick Ă€r en halvledarkristall som endast Ă€r nĂ„gra tiotals nanometer stor. Den ligger oftast inbĂ€ddad inuti en större kristall av ett annat halvledarmaterial och pga. den begrĂ€nsade storleken fĂ„r en kvantprick mycket speciella egenskaper. Bland annat sĂ„ kommer elektronerna i en kvantprick endast att kunna anta vissa diskreta energinivĂ„er liknande situationen för elektronerna i en atom. Följaktligen kallas kvantprickar ofta för artificiella atomer. För halvledarmaterial gĂ€ller det generellt att det inte endast Ă€r fria elektroner i ledningsbandet, som kan leda ström utan Ă€ven tomma elektrontillstĂ„nd i valensÂbandet, vilka upptrĂ€der som positivt laddade partiklar, kan leda ström. Dessa kallas kort och gott för hĂ„l. I en kvantprick har hĂ„len sĂ„som elektronerna helt diskreta energinivĂ„er. Precis som Ă€r fallet i en atom, sĂ„ kommer elektroniska övergĂ„ngar mellan olika energiÂnivĂ„er i en kvantprick att resultera i att ljus emitteras. Energin (dvs. vĂ„glĂ€ngden alt. fĂ€rgen) för detta ljus bestĂ€ms av hur energinivĂ„erna i kvantÂpricken ligger, för elektronerna och hĂ„len, och genom att analysera ljuset kan man sĂ„ledes studera kvantprickens egenskaper. Studierna i den hĂ€r avhandlingen visar att vĂ€xelverkan mellan en kvantprick och den omgivande kristallen, som den ligger inbĂ€ddad i, har stor inverkan pĂ„ kvantprickens optiska egenskaper. T.ex. visas att man kan kontrollera antalet elektroner, som kommer att finnas i kvantpricken genom att modifiera hur elektronerna kan röra sig i omgivningen. Dessa rörelser modifieras hĂ€r genom att variera temperaturen och genom att lĂ€gga pĂ„ ett magnetiskt fĂ€lt. Ett magnetiskt fĂ€lt, vinkelrĂ€tt mot en elektrons rörelse, kommer att böja av dess bana och dess chans att nĂ„ fram till kvantpricken kan sĂ„ledes minskas. Elektronen kan dĂ„ istĂ€llet fastna i andra potentialgropar i kvantprickens nĂ€rhet. Genom att öka temperaturen, vilket ger elektronerna större energi, kan deras chans att nĂ„ fram till kvantpricken Ă„ andra sidan öka. En annan effekt, som studerats, Ă€r möjligheten att kontrollera spinnet hos elektronerna i en kvantprick. Ăven i dessa studier visar det sig att vĂ€xelverkan med omgivningen spelar stor roll och kan anvĂ€ndas till att kontrollera elektronens spin. Mekanismen som föreslĂ„s Ă€r att om elektronerna hinner före hĂ„len till kvantpricken, sĂ„ hinner de överföra sitt spin till atomkĂ€rnorna i kvantpricken. PĂ„ detta sĂ€tt kan man fĂ„ atomkĂ€rnornas spin polariserat, vilket resulterar i ett inbyggt magnetfĂ€lt, i storleksordningen 1.5 Tesla, som i sin tur hjĂ€lper till att upprĂ€tthĂ„lla en hög grad av spinpolarisering Ă€ven hos elektronerna. För att fĂ„ elektronerna att hinna först, mĂ„ste deras rörelser i omgivningen kontrolleras. I en ytterligare studie undersöktes den process dĂ€r en elektronisk övergĂ„ng i kvantpricken inte enbart resulterar i emission av ljus, utan Ă€ven i att en annan partikel tar över en del av energin och blir exciterad. Dessa processer avspeglas i att en del av det ljus som emitteras har lĂ€gre energi. Detta ljus Ă€r ocksĂ„ mycket svagt, ca 1000 ggr lĂ€gre intensitet, och möjligheten att kunna mĂ€ta detta Ă€r helt beroende pĂ„ hur ljusstarka kvantprickarna Ă€r. De prover som anvĂ€nts i denna studie bestĂ„r av pyramidstrukturer, ca 7.5 mikrometer stora, med kvantprickar inuti. Denna geometri ger ca 1000 ggr bĂ€ttre ljusutbyte jĂ€mfört med traditionella strukturer, vilket möjliggjort studien
Ekolometer - Ett sÀljverktyg med fokus pÄ miljöpÄverkan
Sustainability thinking and environmental questions are often in the center of news today. Our planet is changing and us humans need to change our lifestyle in order to avoid potentially devastating events. New laws and regulations, along with new sustainability goals, are constantly arriving around the world. Within the maritime industry, multiple emission goals have recently been implemented which puts a lot of pressure on shipping companies around the world. This thesis introduces a new sales-tool, The Ecolometer, which purpose is to support sales-processes within Volvo Penta. The tool uses a Product Environmental Footprint methodology to quantify different environmental impact categories based on the Nine Planetary Boundaries model. Based on the Planetary Boundaries model, some focus categories have been selected which has been set as requirements for the new tool. The tool have been validated and tested on some cases, where different propulsion systems where investigated. The results shows that the method and tool is useful and applicable to the intended purpose. The tool provides an efficient and easy way to quantify and optimize environmental impact throughout the lifecycle of a vessel, while in the meantime making sustainability thinking accessible, and popular within the industry. The thesis also shows how necessary it is for Volvo Penta the implement this tool, in order to ensure that their sustainability investments is going in the right direction.MiljöfrÄgor ligger ofta i fokus i dagens debatt, och att tÀnka miljövÀnligt och hÄllbart blir allt mer ett socialt krav. VÄr planet förÀndras, och vi mÀnniskor mÄste göra stora förÀndringar i hur vi lever för att undvika att potentiella katastrofer uppstÄr. Nya lagar, regler och hÄllbarhetsmÄl Àr konstant uppsatta runt om i vÀrlden för hur vi ska leva. Inom den maritima industrin sattes nyligen stora mÄl upp i hur mycket utslÀpp som tillÄts för fartyg runt vilket sÀtter stor press pÄ företag inom branschen runt om i vÀrlden. Denna uppsats introducerar ett nytt försÀljningsverktyg, Ecolometern, vars syfte Àr att hjÀlpa och assistera Volvo Pentas sÀljprocesser. Verktyget anvÀnder sig av en Product Environmental Footprint metodologi för att kvantifiera miljöpÄverkan utifrÄn olika kategorier i Nine Planetary Boundaries modellen. Baserat pÄ modellen, har ett antal kategorier valts ut, som agerar kriterier för det nya verktyget. Verktyget har Àven blivit validerat och testa mot ett antal case, dÀr olika drivlinor har blivit analyserade. Resultatet visar att metoden och verktyget Àr anvÀndbart för det uppsatta syftet. Verktyget ger ett effektivt men enkelt sÀtt att visa och optimera miljöpÄverkan sett till hela livscykeln av ett fartyg, samtidigt som det gör hÄllbarhetstÀnk mer tillgÀngligt och populÀrt inom industrin. Uppsatsen visar ocksÄ pÄ nödvÀndigheten för Volvo Penta att implementera detta verktyg, för att försÀkra sig om att deras hÄllbarhetssatsningar verkligen gÄr Ät rÀtt hÄll
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