Linköping University

About: Linköping University is a education organization based out in Linköping, Sweden. It is known for research contribution in the topics: Population & Thin film. The organization has 15671 authors who have published 50013 publications receiving 1542189 citations.

System Level Hardware/Software Partitioning Based on Simulated Annealing and Tabu Search

Abstract: This paper presents two heuristics for automatic hardware/software partitioning of system level specifications. Partitioning is performed at the granularity of blocks, loops, subprograms, and processes with the objective of performance optimization with a limited hardware and software cost. We define the metric values for partitioning and develop a cost function that guides partitioning towards the desired objective. We consider minimization of communication cost and improvement of the overall parallelism as essential criteria during partitioning. Two heuristics for hardware/software partitioning, formulated as a graph partitioning problem, are presented: one based on simulated annealing and the other on tabu search. Results of extensive experiments, including real-life examples, show the clear superiority of the tabu search based algorithm.

A New Donor–Acceptor–Donor Polyfluorene Copolymer with Balanced Electron and Hole Mobility†

Abstract: A New Donor-Acceptor-Donor Polyfluorence Copolymer with Balanced Electron and Hole Mobility

Electrochemical bandgaps of substituted polythiophenes

Abstract: The electrochemical bandgaps for different soluble substituted polythiophenes have been measured by cyclic voltammetry. The effect of substituents on the oxidation/reduction potentials is discussed. Bandgaps obtained by cyclic voltammetry have been found to be in general higher than optical bandgaps. Among regioregular polymers substituted with a phenyl group at position 3 of the thiophene ring, examples are found that give very symmetric voltammograms. Rationalization for this behaviour is discussed from a conformational point of view.

Evidence of poor vitamin status in coeliac patients on a gluten‐free diet for 10 years

Abstract: Summary Background : Patients with coeliac disease are advised to keep to a lifelong gluten-free diet to remain well. Uncertainty still exists as to whether this gives a nutritionally balanced diet. Aim : To assess the vitamin nutrition status of a series of coeliac patients living on a gluten-free diet for 10 years. Methods : Thirty adults with coeliac disease (mean age, 55 years; range, 45–64 years; 60% women), in biopsy-proven remission following 8–12 years of dietary treatment, were studied. We measured the total plasma homocysteine level, a metabolic marker of folate, vitamin B-6 and vitamin B-12 deficiency, and related plasma vitamin levels. The daily vitamin intake level was assessed using a 4-day food record. Normative data were obtained from the general population of the same age. Results : Coeliac patients showed a higher total plasma homocysteine level than the general population, indicative of a poor vitamin status. In accordance, the plasma levels of folate and pyridoxal 5′-phosphate (active form of vitamin B-6) were low in 37% and 20%, respectively, and accounted for 33% of the variation of the total plasma homocysteine level (P < 0.008). The mean daily intakes of folate and vitamin B-12, but not of vitamin B-6, were significantly lower in coeliac patients than in controls. Conclusions : Half of the adult coeliac patients carefully treated with a gluten-free diet for several years showed signs of a poor vitamin status. This may have clinical implications considering the linkage between vitamin deficiency, elevated total plasma homocysteine levels and cardiovascular disease. The results may suggest that, when following up adults with coeliac disease, the vitamin status should be reviewed.

Abiotic reduction of mercury by humic substances in aquatic system — an important process for the mercury cycle

Abstract: The potential ability of humic substances to reduce Hg(II) to Hg(0) in aqueous systems and, consequently, strongly influence Hg speciation and mobility in the environment is known but has not been studied in detail. A demonstration of the redox behavior of Hg in the presence of humic substances is made in the present work. Calculations show that the reduction is thermodynamically possible. The effects of some chemical parameters (pH, aerobic/anaerobic conditions, presence of chloride) on the process were studied experimentally. Hg(0) production was highest in O2-free systems in the absence of chloride at pH ca 4.5, when ca 25% of initially 2x10−6 M Hg(II) was reduced to Hg(0) in 50 hr. The presence of a competing ion (10−4 M Eu) in the system as well as methylation of the carboxyl groups in the humic substance considerably reduced the Hg(0) production. The practical importance of the abiotic reduction of Hg in the environment is pointed out.