Physical Properties of the Pb1-xSnxTe Solid Solutions in the Vicinity of the Topological Phase Transition | Chapter 7 | Current Perspective to Physical Science Research Vol. 6

Semiconductor Pb1-xSnxTe solid solutions (PSTS) are well known as promising materials widely used in the IR electronics, thermoelectricity and other fields of science and technology. Recently, it has been found that these alloys in certain concentration ranges exhibit the properties characteristic of the new quantum objects of solid-state physics – topological crystalline insulators (TCIs), whose unique properties define new possibilities for practical use of these materials in spintronics, quantum computing and thermoelectricity. The fact that in PSTS, the band inversion near some composition xc leads to the emergence of the TCI states stimulates a detailed study of the behavior of the lattice, transport, and thermoelectric properties near xc. The goal of the studies presented here was to reveal effects accompanying the band inversion in PSTS by measuring the x-dependences of the heat capacity Cp, microhardness H, lattice thermal conductivity λ L electrical conductivity σ, charge carrier mobility μ H, the Hall coefficient RH, and the Seebeck coefficient S in the range x = (0.59 – 0.68), near the composition (x ~ 0.62) corresponding to the transition to an inversion  state at room temperature. It was established that the transition to the band inverted state is manifested through the appearance of peaks in the isotherms (T = 77-300 K) of  CP, H, σ, RH , μH, and S at x ~ 0.62. In the λL (X) isotherms, we observed two peaks near x =0.61 and x=0.63 and suggested that one peak corresponded to the band inversion point, and the other peak – to a structural self-organization process in the crystal lattice.

Author(s) Details:

E. I. Rogacheva,
National Technical University, Kharkiv Polytechnic Institute, 2 kyrpychova St., 61002 Kharkiv, Ukraine.

G. O. Nikolaenko,
National Technical University, Kharkiv Polytechnic Institute, 2 kyrpychova St., 61002 Kharkiv, Ukraine.

O. N. Nashchekina,
National Technical University, Kharkiv Polytechnic Institute, 2 kyrpychova St., 61002 Kharkiv, Ukraine.

Please see the link here: https://stm.bookpi.org/CPPSR-V6/article/view/13254

Keywords: Pb1–xSnxTe, topological crystalline insulator, band inversion, heat capacity, microhardness, thermal conductivity, electrical conductivity, hall coefficient, charge carrier mobility, seebeck coefficient, self-organization

Calculation of the Expanded Uncertainty of the Measurements of the Moisture Content of a Lot of Paper Samples | Chapter 09 | Challenges and Advances in Chemical Science Vol. 8

 Oven drying at 105°C was explored as a method for determining the dry matter content in the laboratory. It was used in this work to determine the moisture content of sheets and boards that did not contain any other chemical compounds save water. The moisture content of a paper sample is mostly determined by the moisture content of its environment.

The goal of this project was to expand on the ISO technique in the laboratory by employing four different paper substrates and statistically analysing the findings.

The proper sampling process, as well as the conditioning of the quality control sample paper, were given priority. The moisture content measurements were carried out in a 105oC oven for 16 hours.

The moisture percentage of the paper substrates studied was 4 percent -6 percent w/w, according to the analytical results. Finally, the moisture content was calculated as a percentage mass fraction using the equation wH2O=((mo-m1)/mo)x100 (1a)

where m0 was the mass of the test piece inside the glass container before oven drying or at the time of sampling, in grammes, and m1 was the mass of the test piece inside the glass container after drying to constant mass, in grammes. For the physical transformation of water into vapour, the definition of the standard enthalpy change was used.

In addition, the combined standard uncertainty was computed as follows:

(RSD rMETHOD2+((u(wH2O)/wH2O)2) RSDTOTAL=(RSD rMETHOD2+((u(wH2O)/wH2O)2) RSDTOTAL=(RSD rMETHOD2+((u(wH2O) (1b)

CV=sr x100/mean (1c) was also used to determine the RSD rMETHOD (repeatability coefficient of variation), where sr=repeatability standard deviation.

For each of the four separate samples of paper, the expanded uncertainty was computed using the equation: Uexpanded = 2.RSDTOTAL at a 95% confidence level and coefficient k=2 (1d).

The statistical analysis of the gravimetric approach presented was required in order to further refine the analytical method employed in the laboratory and thus produce exact results, as well as to quantify extended uncertainties and estimate moisture content expectations. The goal of the study was to quantify the uncertainty of measuring the moisture content of paper samples in the lab and to investigate the statistics of this measurement using mathematical models.

Author(S) Details

Katerina Chryssou
General Chemical State Laboratory, B Chemical Service of Athens, An. Tsocha 16, 11521 Athens, Greece.

Maria Stassinopoulou
General Chemical State Laboratory, B Chemical Service of Athens, An. Tsocha 16, 11521 Athens, Greece.

Eugenia Lampi
General Chemical State Laboratory, B Chemical Service of Athens, An. Tsocha 16, 11521 Athens, Greece.

View Book:- https://stm.bookpi.org/CACS-V8/article/view/5633

Study on the Ecological Outcome of Climate Change in Lake Kinneret, Israel: An Approach towards Thermal Pollution | Chapter 9 | Modern Advances in Geography, Environment and Earth Sciences Vol. 5

 The goal of this research is to determine the effects of thermal fluctuations on water quality. Pollution-related water quality degradation includes a number of factors, including nutrient input loads, fishery management, hydrological budget, toxicity, watershed deforestation, soil exposure, and exotic invaders. Thermal pollution is usually thought of as the result of power plant or nuclear power plant effluent, or as the result of a severe thermal shock. The long-term impact of global warming consideration has not been thoroughly investigated. The influence of climate change (warming and precipitation loss) on the Lake Kinneret ecology over time (1969-2001) is discussed. Temperatures of water and air, as well as heat capacity and thermal conductivity of water, are investigated in conjunction with less precipitation and a drop in lake water level. The temperature of surface water increased with WL reduction and reduced in deep layers during high WL, according to the findings. This study demonstrates that even slight thermal changes can signify ecological change. For a lake under water inflow reduction followed by WL and volume drop, the single thermal measure of degrees may be insignificant. It is advised that future management design be implemented.

Author (s) Details

Moshe Gophen
MIGAL, Scientific Research Institute, Kiryat Shmona, Israel.

View Book :- https://stm.bookpi.org/MAGEES-V5/article/view/2410