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- Athanassiadis, Dimitris, et al.
(författare)
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Is there enough primary forest fuel available to feed into the existing and planned CHP facilities? The case of Northern Sweden
- 2010
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Ingår i: Publications / FINBIO. - 1239-4874. ; , s. 77-83
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Konferensbidrag (refereegranskat)abstract
- A combined GIS and optimization method was used to calculate logging residue (slash and stumps) flows and expected costs at the heating or combined heat and power plants (CHP) in Northern Sweden for two logging residue supply chains. Regional primary forest energy availability was estimated considering ecological, technical and economical restrictions. Two supply chains were considered: One supply chain was based on truck transport of the fuel to the CHP plants and the other one was based on collecting the fuel to terminals adjacent to railway lines and transporting it by train to plants that are located in Central Sweden. The costs for each supply chain were calculated based on current costs for harvesting, forwarding, chipping/crushing, machine allocation to the harvesting site, road transport, compensation to the land owner and administration. The lowest cost pathway to the plants was selected. The effects of the establishment of the CHP plants on regional development are discussed
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- Eriksson, Ola, et al.
(författare)
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Introducing cost-plus-loss analysis into a hierarchical forestry planning environment
- 2014
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Ingår i: Annals of Operations Research. - : Springer Science and Business Media LLC. - 0254-5330 .- 1572-9338. ; 219, s. 415-431
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Tidskriftsartikel (refereegranskat)abstract
- Cost-plus-loss analysis of data for forestry planning has often been carried out for highly simplified planning situations. In this study, we suggest an advance in the cost-plus-loss methodology that aims to capture the hierarchical structure and iterative nature of planning by the large forest owner. The simulation system that is developed to simulate the planning process of the forest owner includes the tactical and operational levels of a continuous planning process. The system is characterized by annual re-planning of the tactical plan with a planning horizon of ten year and with the option to reassess data for selected stands before operational planning. Operational planning is done with a planning horizon of two years and the first year of the plan is considered to have been executed before moving the planning process one year forward. The annual cycle is repeated 10 times, simulating decisions made over a ten-year time horizon. The optimizing planning models of the system consider wood flow requirements, available harvest resources, seasonal variation of ground conditions and spatiality. The data used are evaluated according to standard procedures in cost-plus-loss analysis. Results from a test case indicate high decision losses when planning at both levels is based on the type of data prevalent in the stand databases of Swedish companies. The losses can be reduced substantially if higher-quality data are introduced before operational planning. In summary, the results indicate that the method makes it possible to analyze where in the planning process one needs better data and their value.
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- Holmström, Hampus, et al.
(författare)
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Energioptimera skogsbruket : fallstudier av potentialen i skogsbränsleanpassningar
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Idag är intresset för skogsbränsle större än vad det varit på många år. Möjligen får man gå tillbaka till förra årtusendets vargavintrar för att finna en motsvarande efterfrågan på skog avsett som bränsle för uppvärmning. Pågående klimatförändringar ställer krav på global nivå att samhällen i allt större utsträckning minskar användningen av fossila bränslen och istället ökar andelen av förnyelsebara energikällor. I Sverige finns högt ställda mål och visionära propositioner kring landets energiförsörjning och hur den på relativt kort tid ska växla över till mer klimatneutrala alternativ. För ett land som Sverige faller det sig naturligt att studera de möjligheter som här ges av våra många skogar. Förutom det uppenbara i att skog kan eldas för att ge värme kan den, nästan lika uppenbart, även användas vid elproduktion. Skogsprodukter används dessutom för framställning av drivmedel i en mängd olika former. Med ett stort intresse och med många pågående forsknings- och utvecklingsprojekt så förefaller skogens potential i ett energisammanhang som mycket stor. Svenskt skogsbruk är dock, av olika anledningar, i stor utsträckning fokuserat på två sortiment; sågtimmer och massaved. I många situationer betraktas skogsbränslesortimentet ännu inte fullt jämställt med de övriga två, utan mer som en restprodukt som eventuellt tillvaratas vid timmer- och massavedsproduktionen. På så sätt etableras merparten av de skogliga produktionsplanerna – avverkningar planeras för att på bästa sätt tillvarata värdet av timret och massaveden. I föreliggande fallstudier undersöks effekter av att anpassa skogsbruket till tre sortiment; timmer, massaved och skogsbränsle, där samtliga betraktas som jämställda och i sammanhanget lika viktiga. Värdet, det pris som respektive sortiment betingar, är förstås inte lika för de tre sortimenten utan enligt en verklig prislista. Fallstudierna genomfördes för tre skogsinnehav i olika delar av landet; för Skellefteå Krafts skogar med tyngdpunkt i norra Västerbottens kustland, för Jämtkrafts skogar kring Östersund och för den produktionsinriktade delen av Göteborgs stadsskogar. Analyserna gjordes med Heureka PlanVis, ett nytt skogligt planeringssystem framtaget av SLU i samarbete med Skogforsk. En välkommen och efterfrågad nytta med Heureka är möjligheterna att anpassa de skogsskötselsystem som simuleras och avses analyseras. Studierna kunde på så sätt baseras på scenarier för dels ett konventionellt trakthyggesbruk, dels ett bränsleanpassat skogsbruk. I bägge fallen är den övergripande målsättningen att nuvärdesmaximera skogsbruket, under ett antal restriktioner (främst för att erhålla realistiska scenarier), emedan bränsleanpassningarna består i ett möjligt ökat uttag av skogsbränsle på ett om möjligt bättre sätt än vid trakthyggesbruket. Att planera för skogsbränsleuttag och anpassa skogsbruket även till skogsbränslet visade sig i föreliggande studie kunna leda till en viss lönsamhetsökning, i genomsnitt med 6 %, samtidigt som skogsbränsleuttaget mer än fördubblades (i genomsnitt med en 158 %-ig ökning). Det bränsleanpassade skogsbruket gav dessutom upphov till ett ökat massavedsuttag, i genomsnitt med 14 %. Detta då bränsleanpassningarna här ledde till en viss lönsamhetsökning vid gallring, som i sin tur ledde till ett något mer gallringsintensivt skogsbruk, i genomsnitt med 1.9 gallringar/omloppstid istället för trakthyggesbrukets 1.3 gallringar/omloppstid. Även omloppstiderna och uttagsvolymerna vid slutavverkning ökade något genom att bränsleanpassa skogsbruket.
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- Holstad, Ylva, et al.
(författare)
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Breastfeeding in primiparous women with congenital heart disease : a register study
- 2024
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Ingår i: International Breastfeeding Journal. - : BMJ Publishing Group Ltd. - 1746-4358. ; 19:1
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundThe number of pregnant women with congenital heart disease (CHD) is rising, and the disease poses increased risks of cardiovascular and obstetric complications during pregnancy, potentially impacting breastfeeding success. This study aimed to investigate breastfeeding in primiparous women with CHD compared to primiparous women without CHD, and to examine potential hindering factors for breastfeeding in women with CHD.MethodsThe data were gathered between 2014 and 2019 and obtained by merging the Swedish Congenital Heart Disease Register (SWEDCON) with the Swedish Pregnancy Register. Primiparous women ≥ 18 years of age with CHD (n = 578) were matched by age and municipality to 3049 women without CHD, giving birth after 22 gestational weeks. Multivariable logistic regression analysis was used to identify factors associated with non-breastfeeding in women with CHD.ResultsFewer women with CHD breastfed than women without CHD two days (94% vs. 97%, p = 0.001) and four weeks after birth (84% vs. 89%, p = 0.006). When all women were analysed, having CHD was associated with non-breastfeeding at both two days and four weeks after birth. For women with CHD, body mass index (BMI) ≥ 30 (OR 3.1; 95% CI 1.4, 7.3), preterm birth (OR 6.4; 95% CI 2.1, 19.0), self-reported history of psychiatric illness (OR 2.4; 95% CI 1.2, 5.1), small for gestational age (OR 4.2; 95% CI 1.4, 12.2), and New York Heart Association Stages of Heart Failure class II − III (OR 6.0; 95% CI 1.4, 26.7) were associated with non-breastfeeding two days after birth. Four weeks after birth, factors associated with non-breastfeeding were BMI ≥ 30 (OR 4.3; 95% CI 2.1, 9.0), self-reported history of psychiatric illness (OR 2.2; 95% CI 1.2, 4.2), and preterm birth (OR 8.9; 95% CI 2.8, 27.9).ConclusionsThe study shows that most women with CHD breastfeed, however, at a slightly lower proportion compared to women without CHD. In addition, factors related to the heart disease were not associated with non-breastfeeding four weeks after birth. Since preterm birth, BMI ≥ 30, and psychiatric illness are associated with non-breastfeeding, healthcare professionals should provide greater support to women with CHD having these conditions.
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- Holstad, Ylva, et al.
(författare)
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Self-rated health in primiparous women with congenital heart disease before, during and after pregnancy : a register study
- 2024
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Ingår i: Scandinavian Cardiovascular Journal. - : Taylor & Francis. - 1401-7431 .- 1651-2006. ; 58:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Poor maternal self-rated health in healthy women is associated with adverse neonatal outcomes, but knowledge about self-rated health in pregnant women with congenital heart disease (CHD) is sparse. This study, therefore, investigated self-rated health before, during, and after pregnancy in women with CHD and factors associated with poor self-rated health.Methods: The Swedish national registers for CHD and pregnancy were merged and searched for primiparous women with data on self-rated health; 600 primiparous women with CHD and 3062 women in matched controls. Analysis was performed using descriptive statistics, chi-square test and logistic regression.Results: Women with CHD equally often rated their health as poor as the controls before (15.5% vs. 15.8%, p = .88), during (29.8% vs. 26.8% p = .13), and after pregnancy (18.8% vs. 17.6% p = .46). None of the factors related to heart disease were associated with poor self-rated health. Instead, factors associated with poor self-rated health during pregnancy in women with CHD were ≤12 years of education (OR 1.7, 95%CI 1.2–2.4) and self-reported history of psychiatric illness (OR 12.6, 95%CI 1.4–3.4). After pregnancy, solely self-reported history of psychiatric illness (OR 5.2, 95%CI 1.1–3.0) was associated with poor self-rated health.Conclusion: Women with CHD reported poor self-rated health comparable to controls before, during, and after pregnancy, and factors related to heart disease were not associated with poor self-rated health. Knowledge about self-rated health may guide professionals in reproductive counselling for women with CHD. Further research is required on how pregnancy affects self-rated health for the group in a long-term perspective.
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- Jonsson, Sara, et al.
(författare)
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Time to childbirth and assisted reproductive treatment in women with congenital heart disease
- 2024
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Ingår i: OPEN HEART. - : BMJ Publishing Group Ltd. - 2053-3624 .- 2398-595X. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- Objective To investigate the time to first childbirth and to compare the prevalence of assisted reproductive treatment (ART) in women with congenital heart disease (CHD) compared with women without CHD. Methods All women in the national register for CHD who had a registered first childbirth in the Swedish Pregnancy Register between 2014 and 2019 were identified. These individuals (cases) were matched by birth year and municipality to women without CHD (controls) in a 1:5 ratio. The time from the 18th birthday to the first childbirth and the prevalence of ART was compared between cases and controls. Results 830 first childbirths in cases were identified and compared with 4137 controls. Cases were slightly older at the time for first childbirth (28.9 vs 28.5 years, p=0.04) and ART was more common (6.1% vs 4.0%, p<0.01) compared with controls. There were no differences in ART when stratifying for the complexity of CHD. For all women, higher age was associated with ART treatment (OR 1.24, 95% CI 1.20 to 1.28). Conclusions Women with and without CHD who gave birth to a first child did so at similar ages. ART was more common in women with CHD, but disease severity did not influence the need for ART. Age was an important risk factor for ART also in women with CHD and should be considered in consultations with these patients.
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