Stockholm University

About: Stockholm University is a education organization based out in Stockholm, Sweden. It is known for research contribution in the topics: Population & Context (language use). The organization has 21052 authors who have published 62567 publications receiving 2725859 citations. The organization is also known as: University of Stockholm & Stockholms universitet.

Direct observation of active catalyst surface phases and the effect of dynamic self-optimization in NiFe-layered double hydroxides for alkaline water splitting

Abstract: Earth-abundant transition metal-based compounds are of high interest as catalysts for sustainable hydrogen fuel generation. The realization of effective electrolysis of water, however, is still limited by the requirement of a high sustainable driving potential above thermodynamic requirements. Here, we report dynamically self-optimized (DSO) NiFe layered double hydroxide (LDH) nanosheets with promising bi-functional performance. Compared with pristine NiFe LDH, DSO NiFe LDH exhibits much lower overpotential for the hydrogen evolution reaction (HER), even outperforming platinum. Under 1 M KOH aqueous electrolyte, the bi-functional DSO catalysts show an overpotential of 184 and −59 mV without iR compensation for oxygen evolution reaction (OER) and HER at 10 mA cm−2. The material system operates at 1.48 V and 1.29 V to reach 10 and 1 mA cm−2 in two-electrode measurements, corresponding to 83% and 95% electricity-to-fuel conversion efficiency with respect to the lower heating value of hydrogen. The material is seen to dynamically reform the active phase of the surface layer during HER and OER, where the pristine and activated catalysts are analyzed with ex situ XPS, SAED and EELS as well as with in situ Raman spectro-electrochemistry. The results show transformation into different active interfacial species during OER and HER, revealing a synergistic interplay between iron and nickel in facilitating water electrolysis.

Gaussian basis sets for the first and second row atoms

Abstract: Gaussian basis sets consisting for first row atoms of 7 s-type and 3 p-type and for second row atoms of 10 s-type and 6 p-type functions with optimized exponents are reported. These basis sets consists of at least two functions per atomic orbital.

Early contact versus separation: effects on mother-infant interaction one year later.

Abstract: : Background: A tradition of separation of the mother and baby after birth still persists in many parts of the world, including some parts of Russia, and often is combined with swaddling of the baby. The aim of this study was to evaluate and compare possible long-term effects on mother-infant interaction of practices used in the delivery and maternity wards, including practices relating to mother-infant closeness versus separation.Methods:A total of 176 mother-infant pairs were randomized into four experimental groups: Group I infants were placed skin-to-skin with their mothers after birth, and had rooming-in while in the maternity ward. Group II infants were dressed and placed in their mothers’ arms after birth, and roomed-in with their mothers in the maternity ward. Group III infants were kept in the nursery both after birth and while their mothers were in the maternity ward. Group IV infants were kept in the nursery after birth, but roomed-in with their mothers in the maternity ward. Equal numbers of infants were either swaddled or dressed in baby clothes. Episodes of early suckling in the delivery ward were noted. The mother-infant interaction was videotaped according to the Parent-Child Early Relational Assessment (PCERA) 1 year after birth.Results:The practice of skin-to-skin contact, early suckling, or both during the first 2 hours after birth when compared with separation between the mothers and their infants positively affected the PCERA variables maternal sensitivity, infant's self-regulation, and dyadic mutuality and reciprocity at 1 year after birth. The negative effect of a 2-hour separation after birth was not compensated for by the practice of rooming-in. These findings support the presence of a period after birth (the early “sensitive period”) during which close contact between mother and infant may induce long-term positive effect on mother-infant interaction. In addition, swaddling of the infant was found to decrease the mother’s responsiveness to the infant, her ability for positive affective involvement with the infant, and the mutuality and reciprocity in the dyad.Conclusions:Skin-to-skin contact, for 25 to 120 minutes after birth, early suckling, or both positively influenced mother-infant interaction 1 year later when compared with routines involving separation of mother and infant.