Master equations for Wigner functions with spontaneous collapse and their relation to thermodynamic irreversibility

Journal of Computational Electronics - Wigner functions, allowing for a reformulation of quantum mechanics in phase space, are of central importance for the study of the quantum-classical...     

Controlling Nozzle Clogging by Secondary Steelmaking Without Reheating

Ever since continuous casting was introduced, nozzle clogging has been a recurring subject of metallurgical research and publications. Nozzle clogging is caused by the deposition of non‐metallic inclusions – on the casting equipment – which are solid at the temperature of casting. Calcium treatment already represents a possible solution to eliminate this phenomenon, but there are special steel grades which do not allow its application either because they are price sensitive or for certain other reasons.³ Cleaning the steel melt by agitation is an alternative solution, but it has time constraints due to the cooling of the melt. Over extensive cooling can be prevented by heating the melt (in ladle), but its introduction and operational costs per heat are often too high for an individual steelmaking plant to afford. The goal of our research is to find metallurgical solution to reduce the rate of nozzle clogging in plants which do not possess a ladle furnace and the time devoted to treatment or the price of the product do not allow Ca‐treatment to be applied.     

On the distance of databases

In the present paper a distance concept of databases is investigated. Two database instances are of distance 0, if they have the same number of attributes and satisfy exactly the same set of functional dependencies. This naturally leads to the poset of closures as a model of changing database. The distance of two databases (closures) is defined to be the distance of the two closures in the Hasse diagram of that poset. We determine the diameter of the poset and show that the distance of two closures is equal to the natural lower bound, that is to the size of the symmetric difference of the collections of closed sets. We also investigate the diameter of the set of databases with a given system of keys. Sharp upper bounds are given in the case when the minimal keys are 2 (or r)-element sets.     

Pulsed Laser Deposition of Photoresponsive Two‐Dimensional GaSe Nanosheet Networks

Synthesis of functional metal chalcogenide (GaSe) nanosheet networks by stoichiometric transfer of laser‐vaporized material from bulk GaSe targets is presented. Uniform coverage of interconnected, crystalline, and photoresponsive GaSe nanosheets in both in‐plane and out‐of‐plane orientations are achieved under different ablation conditions. The propagation of the laser‐vaporized material is characterized by in situ ICCD‐imaging. High (1 Torr) Ar background gas pressure is found to be crucial for the stoichiometric growth of GaSe nanosheet networks. Individual 1–3 layer GaSe triangular nanosheets of ≈200 nm domain size are formed within 30 laser pulses, coalescing to form nanosheet networks in as few as 100 laser pulses. The thickness of the deposited networks increases linearly with pulse number, adding layers in a two‐dimensional (2D) growth mode. GaSe nanosheet networks show p‐type semiconducting characteristics with mobilities reaching as high as 0.1 cm²V^?1s^?1. Spectrally‐resolved photoresponsivities and external quantum efficiencies range from 0.4 AW^?1 and 100% at 700 nm, to 1.4 AW^?1 and 600% at 240 nm, respectively. Pulsed laser deposition under these conditions appears to provide a versatile and rapid approach to stoichiometrically transfer and deposit functional networks of 2D nanosheets with digital thickness control and uniformity for a variety of applications.     

How buildings affect the local climate

Big new developments with large individual apartment blocks still feature in the housing work of many countries in eastern Europe. This article briefly reviews wind tunnel investigations in Hungary which show, inter alia, that the resulting ‘heat island’ can create a poorly ventilated zone above the centre of the development, and that very long facades are vulnerable to air borne pollution. The author is a senior research officer at ETI, the Hungarian Institute for Building Science.     

Analysis of Parameter Estimation Possibilities of the Thermal Contact Resistance Using the Laser Flash Method with Two-Layer Specimens

The paper presents a curve-fitting-based calculation of the thermal contact resistance and other parameters (absorbed energy and material properties) from laser flash measurements considering a two-layer specimen (aluminum substrate and stainless-steel film). Sensitivity analysis of different cases was used to examine the sensitivities of the unknown parameters: thermal contact resistance, absorbed energy, specific heat of the film, and thermal conductivity of the film. A nonlinear curve-fitting method was applied to perform the estimation of the unknown parameters using simulated measurements generated by the solution of the direct problem. An extensive analysis was performed to examine which parameters might be estimated simultaneously with the contact resistance for different noise levels of the simulated measurement. It was concluded that in the noiseless case all four unknown parameters can be estimated simultaneously with high accuracy. The noise has a significant effect on the accuracy of the parameter estimation, but even when a reasonable noise level is present, it is still possible to accurately estimate one or two parameters together with the thermal contact resistance.     

Evaluation of Tack Behaviour of Coating Solutions

A new apparatus was constructed and a method was suggested to measure the tackiness of tablet coating solutions. The method is simple, rapid, reproducible and it can be used to fulfil either researchal or control investigations.

Water solutions/or dispersions/of seven different coating materials widely used in the industry were investigated. On the basis of experimental results it was concluded that increase in concentration of solution led to increase in tackiness. By the evaluation of the data gained from the tack values vs. concentration curves it was possible to choose the concentration of coating solution which proved to be the most favorable from the aspects of both producing requirements and tackiness.

The construction and the evaluation of the so called “Tack curves” showing the change of tackiness in time. The data of these curves add further useful informations to the optimization of the production parameters of coating.     

Arsenic removal from rice by washing and cooking with water

Two Hungarian and one Chinese rice samples were selected in order to establish the extractable arsenic content by washing and cooking in water in a ratio of 6:1, water:rice (cm³:g) by inductively coupled plasma sector field mass spectrometry (ICP-SF-MS). Total arsenic concentration of the Zhenshan 97, Risabell and Ko?röstáj-333 samples were 171.3 ± 7.1 ng g⁻¹, 116.0 ± 3.7 ng g⁻¹ and 139.0 ± 6.1 ng g⁻¹, respectively, which did not exceed the toxic limits established for As in Hungary (0.3 μg g⁻¹) or in China (0.7 μg g⁻¹). The predominant chemical form of As in the raw rice samples determined by on-line high performance liquid chromatography and ICP-MS was arsenite. Moreover, enzymatic hydrolysis with α-amylase + protease and microprobe focused sonication proved that arsenite could be removed in the highest extent by washing and cooking, meanwhile the main As form remaining in the cooked rice was As(V). Thus, it is recommended to prepare rice-containing dishes in abundant water, which should be discarded after washing and cooking. The results were validated with a NIST SRM 1568a.