Ion-selective carbon-paste electrodes for halides and silver(I) ions

The behaviour of a simple type of ion-selective electrode for halogens and silver has been studied. The electrode consists of a plastic body filled with carbon paste, the surface of which can be easily renewed. The paste composition is based on carbon-nujol (5:1, w/v) or carbon-paraffin wax (3:1,w/w) containing a prepared mixture of silver halide-silver sulphide (1–30%). The electrodes have low ohmic resistance and show a rapid Nernstian response (within 2–5 mV) for halide and silver ions down to 5·10-5 M chloride, 1·10-5 M bromide and 5·10-7 M iodide with the respective electrodes. Ions forming very stable complexes with halide or silver and those having strong oxidizing or reducing action interfere

Media Takes: On Aging

With the longevity revolution, humankind enters a new and unprecedented stage of development, the impact of which is even greater because of its rapidity. This report/styleguide is an important step in overcoming ageist language and beliefs by providing journalists and others who work in the media with an appropriate body of knowledge, including a lexicon that helps redefine and navigate this new world

Coupling between static friction force and torque

We show that the static friction force which must be overcome to render a sticking contact sliding is reduced if an external torque is also exerted. As a test system we study a planar disk lying on horizontal flat surface. We perform experiments and compare with analytical results to find that the coupling between static friction force and torque is nontrivial: It is not determined by the Coulomb friction laws alone, instead it depends on the microscopic details of friction. Hence, we conclude that the macroscopic experiment presented here reveals details about the microscopic processes lying behind friction.Comment: 6 pages, 4 figures, revte

Coupling between static friction force and torque for a tripod

If a body is resting on a flat surface, the maximal static friction force before motion sets in is reduced if an external torque is also applied. The coupling between the static friction force and static friction torque is nontrivial as our studies for a tripod lying on horizontal flat surface show. In this article we report on a series of experiments we performed on a tripod and compare these with analytical and numerical solutions. It turns out that the coupling between force and torque reveals information about the microscopic properties at the onset to sliding.Comment: 7 pages, 4 figures, revte

Hysteresis and Noise from Electronic Nematicity in High Temperature Superconductors

An electron nematic is a translationally invariant state which spontaneously breaks the discrete rotational symmetry of a host crystal. In a clean square lattice, the electron nematic has two preferred orientations, while dopant disorder favors one or the other orientations locally. In this way, the electron nematic in a host crystal maps to the random field Ising model (RFIM). Since the electron nematic has anisotropic conductivity, we associate each Ising configuration with a resistor network, and use what is known about the RFIM to predict new ways to test for electron nematicity using noise and hysteresis. In particular, we have uncovered a remarkably robust linear relation between the orientational order and the resistance anisotropy which holds over a wide range of circumstances.Comment: References added; minor wording change

Экономическая целесообразность прогнозирования брака по параметру биения

Для выбора экономически целесообразного применения технологий обработки и сборки предлагается учитывать величину прогнозированного брака по параметру биения.For the choice economic expedient application of technologies of treatment and assembling the method of prognostication of marriage is offered on the parameter of beating

Косвенные методы измерения неравномерности воздушного зазора асинхронных электродвигателей

As widely known laser materials processing has some advantages regarding local heat input and controllability. In many fields applications were developed which are not accessible for conventional thermal processing. In other fields laser-supported manufacturing techniques are a valuable alternative. On the one hand laser techniques enable increased processing speed and less post-processing, leading to an increased productivity. On the other hand low efficiencies in the energy conversion seem to be a major drawback and apparently limit the range of applications. In the frame of conventional processing schemes laser beam welding requires a high utilization in order to run economically. Main advantages lie in the reduced consumption of material and the reduced efforts in post processing. Because of the locally concentrated heat input process emissions are lower which reduces energy and material consumption in the auxiliary chain. To make full use of the often-conjured flex ibility a multitude of manufacturing schemes had been developed and adapted. In order to appraise the versatility of laser driven processing techniques a cost and benefit analysis based on a life-cycle approach is conducted including both, economics and ecology. Eco-efficiency is rated by a variation of the BASF method. Taking into account the reduced consumption of consumables, reduced effort for preparation and post-processing, and focusing on specific application ranges a positive environmental impact can be proven