Münster University of Applied Sciences

About: Münster University of Applied Sciences is a education organization based out in Münster, Germany. It is known for research contribution in the topics: Luminescence & Laser. The organization has 694 authors who have published 1067 publications receiving 12597 citations.

Synthesis and Properties of Tetracyanamidosilicates ARE[Si(CN2)4]

Abstract: Tetracyanamidosilicates of the type ARE[Si(CN2)4] with A = K, Rb, and Cs and RE = Y and La−Lu have been prepared by a solid-state metathesis reaction. The potassium compounds with RE = La−Gd crystallize orthorhombically in the space group P21212. Rubidium as well as cesium compounds crystallize tetragonally in the space group I4. The luminescent properties of ARE[Si(CN2)4]:Ln compounds with RE = Y, La, and Gd doped with 5 mol % Ln = Ce, Eu, or Tb were investigated. Temperature-dependent magnetic susceptibilities were measured for KGd[Si(CN2)4]. The value of the magnetic moment is 7.3 μB/Gd3+ ion, which is in line with the expected value for the [Xe]4f7 configuration of Gd3+.

Effect of a Sodium and Calcium DL-β-Hydroxybutyrate Salt in Healthy Adults.

Abstract: Background. Ketone body therapy and supplementation are of high interest for several medical and nutritional fields. The intake of ketone bodies is often discussed in relation to rare metabolic diseases, such as multiple acyl-CoA dehydrogenase deficiency (MADD), that have no alternatives for treatment. Case reports showed positive results of therapy using ketone bodies. The number of ketone body salts offered on the wellness market is increasing steadily. More information on the kinetics of intake, safety, and tolerance of these products is needed. Methods. In a one-dose kinetic study, six healthy subjects received an intervention (0.5 g/kg bw) using a commercially available ketone body supplement. The supplement contained a mixture of sodium and calcium D-/L-β-hydroxybutyrate (βHB) as well as food additives. The blood samples drawn in the study were tested for concentrations of D-βHB, glucose, and electrolytes, and blood gas analyses were done. Data on sensory evaluation and observed side effects of the supplement were collected. The product also went through chemical food analysis. Results. The supplement led to a significant increase of D-βHB concentration in blood 2.5 and 3 h after oral intake ( ). The first significant effect was measured after 2 h with a mean value of 0.598 ± 0.300 mmol/L at the peak, which was recorded at 2.5 h. Changes in serum electrolytes and BGA were largely unremarkable. Taking the supplement was not without side effects. One subject dropped out due to gastrointestinal symptoms and two others reported similar but milder problems. Conclusions. Intake of a combination of calcium and sodium D-/L-βHB salt shows a slow resorption with a moderate increase of D-βHB in serum levels. An influence of βHB salts on acid-base balance could not be excluded by this one-dose study. Excessive regular consumption without medical observation is not free of adverse effects. The tested product can therefore not be recommended unconditionally.

Semiconductor ceramics for NTC thermistors : the reliability aspects

Abstract: Thermally induced processes in ceramic–electrode interfaces of CuxNi1–x–yCo2yMn2–yO4-based NTC thermistors as a function of their chemical compositions and quantitative parameters of low-temperature annealing at 400–800° C are studied. Thermal treatment of thermistors at 400-600° C during 15 h leads to degradation of the metallization layers for the majority of the investigated samples owing to the migration of electrode material (silver) into ceramic body. An accompanying anomalous increase of thermistors' electrical conductivity is observed. The following thermal treatment during 15 h at 800°C leads to an electrical conductivity regeneration to, approximately, the initial values. The reversible nature of this phenomenon is confirmed by Auger-spectroscopy method. Some of the studied NTC thermistors appear to be stable to low-temperature thermal treatment. These compositions are proposed for applications in devices operating at the temperatures up to 530° C.