The experimental THz-excitation spectroscopy technique for determining heterojunction band offsets is suggested. When photoexcited electrons gain sufficient energy to pass the potential barrier ...corresponding to a conduction band offset, an amplitude of THz-emission pulse sharply increases, which allows for direct measurements of the offset value. The technique is applied for determining GaAsBi-GaAs band offsets. The deduced conduction band offset of GaAsBi-GaAs heterojunction has about 45% of an energy gap difference at the Bi concentrations x < 0.12 investigated.
The purpose of this paper was to investigate the influence of fabrication conditions of the carbon based cobalt(II, III) oxide (Co3O4/C) and Au supported Co3O4/C (AuCo3O4/C) catalysts on their ...electrocatalytic activities towards the oxygen reduction reaction (ORR). The catalysts were prepared using impregnation and microwave irradiation methods. It has been found, that the combination of both of these methods was a more efficient way for fabrication of high catalytically active Co3O4/C and AuCo3O4/C catalysts. The synthesized Co3O4/C and AuCo3O4/C catalysts showed high electrocatalytic activity towards the oxygen reduction reaction in an alkaline medium. The ORR onset potential for the investigated catalysts was comparable to theoretical ORR potential values between 0.7 and 0.9 V vs. reversible hydrogen electrode (RHE).
•Different preparation approaches for the Co3O4/C and AuCo3O4/C catalysts.•Electrocatalysts for oxygen reduction.•Higher activity of AuCo3O4/C towards oxygen reduction.
Patients with type 2 diabetes are at high risk of fatal and non-fatal myocardial infarction and stroke. There is indirect evidence that agonists of peroxisome proliferator-activated receptor γ (PPAR ...γ) could reduce macrovascular complications. Our aim, therefore, was to ascertain whether pioglitazone reduces macrovascular morbidity and mortality in high-risk patients with type 2 diabetes.
We did a prospective, randomised controlled trial in 5238 patients with type 2 diabetes who had evidence of macrovascular disease. We recruited patients from primary-care practices and hospitals. We assigned patients to oral pioglitazone titrated from 15 mg to 45 mg (n=2605) or matching placebo (n=2633), to be taken in addition to their glucose-lowering drugs and other medications. Our primary endpoint was the composite of all-cause mortality, non fatal myocardial infarction (including silent myocardial infarction), stroke, acute coronary syndrome, endovascular or surgical intervention in the coronary or leg arteries, and amputation above the ankle. Analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN NCT00174993.
Two patients were lost to follow-up, but were included in analyses. The average time of observation was 34·5 months. 514 of 2605 patients in the pioglitazone group and 572 of 2633 patients in the placebo group had at least one event in the primary composite endpoint (HR 0·90, 95% CI 0·80–1·02, p=0·095). The main secondary endpoint was the composite of all-cause mortality, non-fatal myocardial infarction, and stroke. 301 patients in the pioglitazone group and 358 in the placebo group reached this endpoint (0·84, 0·72–0·98, p=0·027). Overall safety and tolerability was good with no change in the safety profile of pioglitazone identified. 6% (149 of 2065) and 4% (108 of 2633) of those in the pioglitazone and placebo groups, respectively, were admitted to hospital with heart failure; mortality rates from heart failure did not differ between groups.
Pioglitazone reduces the composite of all-cause mortality, non-fatal myocardial infarction, and stroke in patients with type 2 diabetes who have a high risk of macrovascular events.
Kūrybinių sugebėjimų vystymas yra vienas iš svarbiausių jaunosios kartos komunistinio ugdymo uždavinių. Piešimo pamokose ši problema dažniausiai buvo sprendžiama mokant turinio prisilaikant ...akademinio piešimo taisyklių, tačiau nepakankamai dėmesio buvo skiriama naudojant įvairias dailės medžiagas ir technikas. Įvairių dailės medžiagų ar technikos naudojimas piešimo pamokose skirtingai veikia mokinių psichiką ir psichologiją, plečia jų akiratį meno srityje, ugdo kūrybinius sugebėjimus, ugdo meninį skonį, padeda įgyti technikos įgūdžius. Todėl tikslinga vidurinės mokyklos piešimo pamokose kaip galima plačiau mokinius pažindinti su akvarelės liejimo technika, tušo, guašo, štampavimo, grafikos ir kt. būdais. Praktikoje susipažinę su įvairiomis meninėmis priemonėmis ir būdais, mokiniai daug giliau suvokia liaudies ir profesionalųjį meną, meno kūrinio turinio ir formos sintezę.
The influence of surface treatment of as-synthesized Cu2ZnSnS4 (CZTS) thin films on the photocurrent response in the photoelectrochemical cell with Eu3+ contact has been studied. With our work we are ...the first, to our knowledge, to show that in order to achieve the maximal photocurrent response of CZTS, dissolution of copper sulfide in a KCN solution and subsequent dissolution of ZnS in a HCl solution is insufficient. An additional treatment in a KCN solution for only 10 s can results in the highest photocurrent density. XPS, photoelectrochemical and the Mott-Schottky measurements reveal a negatively charged layer of surficial chlorides on the CZTS film. This layer was captured during removal of the ZnS secondary phase from CZTS film surface in a HCl solution. It has been shown that this layer is the reason why it was impossible to reach the maximum photocurrent. XRD, SEM and XPS measurements demonstrated the dissolution of copper sulfide in a KCN solution, zinc sulfide in a HCl solution and removal of a thin layer of copper chloride during a short (10 s) additional treatment in a KCN solution.
This work is focused on the study of self-ordered titania nanotube arrayed electrodes for preparation of efficient gold-nickel/titania nanotubes electrocatalysts (denoted as Au(Ni)/TiO sub(2)-NTs) ...for the oxidation of hydrazine in an alkaline medium. The Au(Ni)/TiO sub(2)-NTs catalysts were prepared by partial galvanic displacement of an electroless Ni layer, deposited on the self-ordered titania, by Au nanoparticles from the gold-containing solution. The morphology, structure and composition of the prepared nano-structured catalysts were examined by Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray Analysis (EDAX), X-ray diffraction (XRD) and Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). The electrocatalytic activity of the prepared catalysts was investigated towards the oxidation of hydrazine in an alkaline medium by means of cyclic voltammetry and chronoamperometry. It was found that the prepared Au(Ni)/TiO sub(2)-NTs catalysts with low Au loadings possess more than ten-twenty times higher electrocatalytic activity towards the oxidation of hydrazine in an alkaline medium as compared to that of Au electrodeposited on TiO sub(2)-NTs and Ni/TiO sub(2)-NTs, presumably due to formation of Au nanoparticles of high dispersivity as well as formation of Ni solid solution in gold.
In this study, we examine the mismatch between the anthropometric and the economic measures of human wellbeing, a fact that has gone unnoticed in the international research on anthropometric history: ...by 1914, Estonian males were among the tallest in the world despite the country's economic underdevelopment. We explain the anthropometric overperformance of Estonia considering the early start of the first demographic transition in relation to the special features of the agrarian reforms in the Baltic provinces. Estonian boys did grow taller than their peers in Lithuania, Finland, and even in the much richer Western countries, because their parents had smaller families.
Although the efficiency of steel fibres for improving mechanical properties (cracking resistance and failure toughness) of the concrete has been broadly discussed in the literature, the number of ...studies dedicated to the fibre effect on structural behaviour of the externally bonded elements is limited. This experimental study investigates the influence of steel fibres on the failure character of concrete elements strengthened with external carbon fibre reinforced polymer sheets. The elements were subjected to different loading conditions. The test data of four ties and eight beams are presented. Different materials were used for the internal bar reinforcement: in addition to the conventional steel, high-grade steel and glass fibre reinforced polymer bars were also considered. The experimental results indicated that the fibres, by significantly increasing the cracking resistance, alter the failure character from splitting of the concrete to the bond loss of the external sheets and thus noticeably increase the load bearing capacity of the elements.
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