Influences of NaCl and Na2SO4 on the Micellization Behavior of the Mixture of Cetylpyridinium Chloride + Polyvinyl Pyrrolidone at Several Temperatures

Herein, the conductivity measurement technique is used to determine the interactions that may occur between polyvinyl pyrrolidone (PVP) polymer and cetylpyridinium chloride (CPC) surfactant in the presence of NaCl and Na2SO4 of fixed concentration at variable temperatures (298.15–323.15 K) with an interval of 5 K. In the absence or presence of salts, we observed three critical micelle concentrations (CMC) for the CPC + PVP mixture. In all situations, CMC1 values of CPC + PVP system were found to be higher in water than in attendance of salts (NaCl and Na2SO4). Temperature and additives have the tendency to affect counterion binding values. Various physico-chemical parameters were analyzed and demonstrated smoothly, including free energy (ΔG0m), enthalpy (ΔH0m) and entropy change (ΔS0m). The micellization process is achieved to be spontaneous based on the obtained negative ΔG0m values. The linearity of the ΔHmo and ΔSmo values is excellent. The intrinsic enthalpy gain (ΔH0*m) and compensation temperature (Tc) were calculated and discussed with logical points. Interactions of polymer hydrophobic chains or the polymer + surfactant associated with amphiphilic surface-active drugs can employ a strong impact on the behavior of the gels.

A Discrepancy in Thermal Conductivity Measurement Data of Quantum Spin Liquid β′-EtMe3Sb[Pd(dmit)2]2 (dmit = 1,3-Dithiol-2-thione-4,5-dithiolate)

A molecular Mott insulator β′-EtMe3Sb[Pd(dmit)2]2 is a quantum spin liquid candidate. In 2010, it was reported that thermal conductivity of β′-EtMe3Sb[Pd(dmit)2]2 is characterized by its large value and gapless behavior (a finite temperature-linear term). In 2019, however, two other research groups reported opposite data (much smaller value and a vanishingly small temperature-linear term) and the discrepancy in the thermal conductivity measurement data emerges as a serious problem concerning the ground state of the quantum spin liquid. Recently, the cooling rate was proposed to be an origin of the discrepancy. We examined effects of the cooling rate on electrical resistivity, low-temperature crystal structure, and 13C-NMR measurements and could not find any significant cooling rate dependence.

In vivo electrical conductivity measurement of muscle, cartilage, and peripheral nerve around knee joint using MR-electrical properties tomography

This study aimed to investigate whether in vivo MR-electrical properties tomography (MR-EPT) is feasible in musculoskeletal tissues by evaluating the conductivity of muscle, cartilage, and peripheral nerve around the knee joint, and to explore whether these measurements change after exercise. This prospective study was approved by the institutional review board. On February 2020, ten healthy volunteers provided written informed consent and underwent MRI of the right knee using a three-dimensional balanced steady-state free precession (bSSFP) sequence. To test the effect of loading, the subjects performed 60 squatting exercises after baseline MRI, immediately followed by post-exercise MRI with the same sequences. After reconstruction of conductivity map based on the bSSFP sequence, conductivity of muscles, cartilages, and nerves were measured. Measurements between the baseline and post-exercise MRI were compared using the paired t-test. Test–retest reliability for baseline conductivity was evaluated using the intraclass correlation coefficient. The baseline and post-exercise conductivity values (mean ± standard deviation) [S/m] of muscles, cartilages, and nerves were 1.73 ± 0.40 and 1.82 ± 0.50 (p = 0.048), 2.29 ± 0.47 and 2.51 ± 0.37 (p = 0.006), and 2.35 ± 0.57 and 2.36 ± 0.57 (p = 0.927), respectively. Intraclass correlation coefficient for the baseline conductivity of muscles, cartilages, and nerves were 0.89, 0.67, and 0.89, respectively. In conclusion, in vivo conductivity measurement of musculoskeletal tissues is feasible using MR-EPT. Conductivity of muscles and cartilages significantly changed with an overall increase after exercise.

Study of the electrical and thermal conductivity of compounds and solid solutions resulting from the study of the triple system (BaCl2-CuSO4-Na2CO3): دراسة الناقلية الكهربائية والحرارية للمركبات والمحاليل الصلبة الناتجة عن دراسة الجملة الثلاثية (BaCl2-CuSO4-Na2CO3)

In this research, the electrical and thermal conductivity of the compounds BaCl2-CuSO4-Na2CO3 - Ba6Na8C4Cl12O12 - Ba6Cu4S4Cl12O16 - Cu6Na8S6C4O36 and the solid solutions resulting from the interaction of these compounds with each other, using the thermal conductivity measuring device (ITP-M64) and electrical conductivity measurement device (the four paths) were studied. The results are different between superconducting materials and medium conductive materials (semiconductors).

Transparent Vacuum Insulation Panels

New, low-cost transparent vacuum insulation panels (TVIPs) using structured cores for the windows of existing buildings are proposed. The TVIP is produced by inserting the structured core, the low-emissivity film, and the adsorbent into the transparent gas barrier envelopes. In this chapter, the authors introduce the outlines, the design and thermal analysis method, the performance evaluation (test) method. Firstly, five spacers, namely peek, modified peek, mesh, silica aerogel, and frame, are selected as the structured core. The effective thermal conductivity of TVIPs with five different spacers is evaluated at different pressure levels by applying numerical calculation. The result indicated that TVIPs with frame and mesh spacers accomplish better insulation performance, with a center-of-panel apparent thermal conductivity of 7.0 × 10−3 W/m K at a pressure of 1 Pa. The apparent thermal conductivity is the same as the value obtained by the simultaneous evacuation thermal conductivity measurement applying the heat flux meter method. Furthermore, using a frame-type TVIP with a total thickness of 3 mm attached to an existing window as a curtain decreases the space heat loss by approximately 69.5%, whereas the light transparency decreases to 75%.

Solid state synthesis, characterization and anti- microbial studies of some transition metal complexes of a schiff base ligand derived from parabenzoquinone and glycine

Schiff base was synthesized by mixing parabenzoquinone and glycine mechanochemically. Its corresponding complexes of Cu, Co and Mn were synthesized by grinding metal (II) carbonates. The synthesized compound were characterized by elemental analysis, infrared spectroscopy, melting/decomposition temperature determination and conductivity measurements .The infrared spectroscopic analysis of the ligand shows a peak at 1620cm-1 confirm the presence of azomethane while the shift to 1602 cm-1,1623.15cm-1, 1635.69cm-1 in Mn, Cu, Co complexes respectively confirmed bond formation from azo-group to metal. The melting point temperature of the ligand at 128.20oC show that it is stable at low temperature while the decomposition temperature of Mn, Cu, Co complexes at 1900C,188.40C,2050C shows that they are stable conductivity measurement shows that the complexes were found to be non-electrolytic as compared with the theoretical values. The ligand and its respective complexes showed antimicrobial activities against some bacteria and fungi at high concentrations(1000 μg/disc and 500μg/disc) respectively while some showed no activity at all concentrations. However, Co complex shows significant activity against all the species at low concentration (250μ/disc).

Identifikasi Salinitas Tanah Menggunakan Instrumen Induksi Elektromagentik EM38 di Kecamatan Baitussalam Kabupaten Aceh Besar

Salinity is the amount of salt contained or dissolved in water or soil. Salinity can cause the change of physical characteristics of soil, especially in coastal area, that affects human daily activities, including agriculture. Baitussalam District (Kecamatan Baitussalam) is one of the districts that was hit most devastatingly by the Indian Ocean Tsunami 2004 as well as has large population with potential agricultural prospect in Aceh Besar Region (Kabupaten Aceh Besar). This research aims to identify the soil salinity level in the Baitussalam District. The sampling technique uses descriptive methodology with scalable quantitative approach in the chosen sampling areas. 26 sampling spots have been chosen according to mathematical calculation. Quantitative method is used to analyze the result in this research. Furthermore, conductivity measurement is done through induction electromagnetic method, using Geonics EM38 and to identify the soil salinity level, analysis of soil texture is conducted in the laboratory. As the result, the electrical conductivity measurement shows varying values. The minimum conductivity value is 0,004 dS/m, taken at spot T 004 in Lam Ujong Village (Desa Lam Ujong). Whereas the maximum conductivity value reaches 10,31 dS/m, taken at spot T 003 in Labuy Village. The soil salinity in the 26 sampling spots in Baitussalam District demonstrates an average level, with a value of ECa 2-4 dS/m. The result of this research is expected to be a parameter to control and develop the activities, especially for agricultural activities, in the coastal area in Aceh Besar Region, and in Baitussalam district in particular.

Toprak Hidrolik İletkenlik Ölçümünün Atölye Koşullarında Modellenmesi

The aim of this study is to model the system that measures soil hydraulic conductivity using Programmable Logic Control (PLC), pressure transducer and motor pump in workshop conditions. In the study, a plastic pipe with a length of 2 m and a diameter of 100 was prepared to simulate an auger hole. In addition, a set was created using PLC and its module. In the hydraulic conductivity measurement system, the auger hole method (the bottom of the auger hole is above the impermeable layer) is used. Using the auger-hole equation, the system’s program was written in CODESYS-ST language and uploaded to the PLC. As a result of the regression analysis between the water head in the pipe (auger-hole) measured by hand (ESY) and PLC (PLCSY), an equation as PLCSY = 0,99ESY + 1,69 (R² = 1) was obtained and the Mean Absolute Percent Error (MAPE) of these two data sets was calculated as 0,41%. Each hydraulic conductivity measurement time is approximately 5, 6 and 8 minutes when the valve is fully open and half open and one-third open. The distance from the pipe base to the static level (d, cm) was measured as averages of 122.83, 123.91 and 123.7 cm on, respectively. In the first quarter section, the average times taken for the water level to rise from 20 to 25, 25 to 30, 30 to 35 and 35 to 40 was determined as 4.4, 6.0 and 26.1 seconds, respectively. The hydraulic conductivity values were calculated as 18.6, 13.2 and 3.1 cm/hour at the valve openings, respectively. The measured data is saved on an SD card. All of these processes are done automatically. The expectation that this system will measure hydraulic conductivity accurately, economically and quickly in field conditions is high and should be tested in field conditions.