CsPd0.875Cr0.125I3 Promising Candidate for Thermoelectric Applications

We study the electronic structure, magnetization, and thermoelectric properties of CsPd0.875Cr0.125I3 obtained by doping CsPdI3 with atoms of the 3d transition metal Cr. By applying the generalized-gradient-approximation (GGA) and the GGA + U one, we found that CsPd0.875Cr0.125I3 alloy exhibits a completely metallic characteristic. Changes in the thermoelectric properties of the alloy are determined with the use of the BoltzTrap code. The electronic thermal conductivities (k/т), Seebeck coefficients (S), power factors (PF), and electrical conductivities (q/т) are calculated. The value of the ZT merit factor is near 1 at room temperature, by indicating that CsPd0.875Cr0.125I3 is a good candidate for thermoelectric applications at high and low temperatures.

A Theoretical Study for Designing Optical Multilayer Films Using NdF3/ ThF4

An idea of a colored glaze is presented in this study to hide and dispose all the obstacles of using solar systems as facades integrated with buildings. This aim is achieved by designing multilayer optical interference filters by using Mat lab program . Appropriate dielectric materials, namely NdF3 of high refractive index (nH =1.6) and ThF4 of low refractive index (nL =1.5143) were employed. Quarter wave thicknesses of high (H) and low (L) refractive index were deposited on a microscopic slide substrate with n=1.513 and 550 nm design wavelength (l°). Two optical models were designed, which are Air//HL//glass and Air//LH//glass, for even numbers of layers (2-32 layers). The challenge in this study is to find the most efficient design which has lower solar reflectance (Rsol.) and higher solar transmittance (Tsol.) to raise the efficiency of the solar systems and, in parallel, obtain the colored reflection to achieve the esthetic appearance of the buildings integrated with the solar system facades. The Tsol. value was high (94-95 %), whereas the Rsol. was very low (4-5 %). Hence, the efficiency of the solar system was increased. The two optical models exhibited green color reflectance in the visible region. The first design, i.e. Air/HL/glass, showed higher values of Rvis. and the merit factor (M) than the second model, resulting in a higher potential of coloration. The first design requires fewer materials and layers, thus, it is more cost-effective as compared to the second one.

The study of structural, electronic and thermoelectric properties of Ca1−xYbxZn2Sb2 (x = 0, 0.25, 0.5, 0.75, 1) Zintl compounds

Based on the electronic structure, the physical properties of [Formula: see text] ([Formula: see text], 0.25, 0.5, 0.75, 1) Zintl compounds are studied. The transport properties can be significantly changed by varying the composition [Formula: see text]. The materials under study are more metallic with increasing [Formula: see text] and behaves like a semiconductor when [Formula: see text] decreases. It is found that [Formula: see text] exhibits a larger thermopower magnitude ([Formula: see text] at [Formula: see text] and the Seebeck coefficient decreases as [Formula: see text] increases. The calculated figure of merit factor of [Formula: see text] is found to be low, this is explained by the fact that its structure is very compact and its bandgap is small which lead to high electrical and thermal conductivity due to high carrier concentration ([Formula: see text] at [Formula: see text]). On other hand a narrow-gap (0.46 eV for [Formula: see text]), provides a balance between a high Seebeck coefficient and low electronic thermal conductivity, with a slight increase in the carrier concentration when the temperature increases ([Formula: see text] at 600 K). As a consequence, [Formula: see text] compound is predicted to have good performance for thermoelectric applications. The electrical [Formula: see text] and the thermal [Formula: see text] conductivity for [Formula: see text] compound in both directions (along [Formula: see text] and [Formula: see text]-axes) are calculated. It is obtained that [Formula: see text] is 120% of [Formula: see text] at high-temperature, whereas [Formula: see text] Seebeck coefficient was higher than [Formula: see text] especially at [Formula: see text] ([Formula: see text]. The large value of [Formula: see text] showed that the transport is dominated by zz-axis.

The first principle calculations of structural, magneto-electronic, elastic, mechanical, and thermoelectric properties of half-metallic double perovskite oxide Sr2TiCoO6

The structural, elastic, mechanical, magneto-electronic, and thermoelectric properties of Sr2TiCoO6 double perovskite oxide have been studied within the framework of density functional theory. The FP-LAPW method within the (GGA) and (mBJ) approximations is chosen in the computational approach. This alloy crystallizes in cubic structure with the ferromagnetic phase. The computed lattice constant was found to agree with the available experimental results. This compound shows the half-metallic ferromagnetic properties. A value of 1 µB is found for the total magnetic moment with an important contribution from Co atoms. The elastic parameters reveal that Sr2TiCoO6 as being super hard and brittle. We calculated the thermoelectric properties of Sr2TiCoO6 using the Boltzmann transport equations within the DFT in a temperature range from 100 to 1000 K. The transport parameters like Seebeck coefficient, electrical thermal conductivity and the merit factor, have been put together to establish their thermoelectric response. The figure of merit value is between [0.71-0.99] indicating that our compound is a good candidate for thermoelectric applications at high and low temperatures.

A Technical Assessment of Comfort Performance of Hanok Using Comparative Field Surveys between Experts and Users

The paper aims to evaluate the psychological factors of the comfort performance of the hanok. This is to guide restoration and improvement in consideration of the intangible variables that provide the quality of the hanok. Through this process, we ultimately intend to build an integrated residential performance evaluation system that includes factors related to the quality of residents’ lives, such as the comfort of their surrounding and indoor environment, as well as the functionality and convenience of the hanok, a representative type of Korean traditional architecture. The test method to evaluate the comfort performance of hanok is largely divided into the physical perception element, which is a quantitative indicator, and the psychological cognitive element, which is a qualitative indicator. Physical perceptive factors are composed of nine quantifiable factors that can be measured by numerical values, namely humidity control, condensation, insulation, thermal comfort, air permeability, solar radiation, solar lighting, sound insulation, and air cleanness. This is a perceptual concept of viewing a building as it is, and a quantitative evaluation method of measuring data in the field using environmental sensors and equipment. Psychological cognitive factors that are evaluated based on the experiences of users (residents) living in hanok, are classified into five categories, of scenery, beauty, deodorization, usability, and health. This study was conducted through a questionnaire between experts and users (residents), limited to the psychological factors among methods of evaluating the comfort performance of hanok. As a result, it can be seen that environmental factors are the main variables that influence the degree of satisfaction with the psychological perception factor. This might be a merit factor of general hanok, and weight could be given when creating an integrated standard in the future.

Study of the Optical Properties of Cobalt Ferrite Magnetic Liquids

In this study, we discussed the optical properties (Faraday rotation, transmittance and Merit factor) of two samples of magnetic liquids synthesized by co-precipitation and an additional hydrothermal synthesis of cobalt ferrite (CoFe2O4) developed according to the protocol developed by R. Massart at the PHENIX laboratory at Pierre and Marie Curie University in the form of ferrofluids. The measurements were carried out using the spectral polarimetric bench (400-1600 nm). The materials did not meet the standard and did not allow a good Faraday rotation due to their preparation conditions. Cobalt ferrite is a hard ferrimagnetic material, having many important applications in the field of magnetic storage and spintronics. The results show a very high spectral Faraday rotation in the Telecom range (1550 nm) with good transparency in the infrared of the transmittance spectra and a strong merit factor around 1550 nm, with a value of the order of 11°. For a cobalt ferrite magnetic liquid obtained hydrothermally.

Optimization of SnO2/Ag nanowire transparent hybrid electrodes for optoelectronic applications

Silver nanowire (Ag NW) networks are gaining more interest as promising candidates for the substitution of indium tin oxide (ITO) for top electrodes in optoelectronic devices. In this work we investigated the electrical, optical, structural, and morphological properties of SnO2/Ag NW hybrid film deposited by spray pyrolysis root. We showed that annealing at appropriate temperature improves optoelectronic and morphological properties of the SnO2/AgNWs electrodes; the optimal annealing temperature was 180 °C for 20 min. These annealing conditions allow better homogenization of the nanowires and their welding at the intersection nodes ensuring conduction of the charge carriers along the conductive grid formed of nanowires. The optimized SnO2/AgNWs electrodes have a large optical window covering the near-UV, Vis and IR range, with an average transparency of 85% and a sheet resistance of 6.1 Ω/sq. These optoelectronic performances have led to a merit factor of 2.5 × 10−2 Ω−1 being a competitive performance among the currently developed electrodes that can be promising candidates for applications as a transparent electrodes in optoelectronic devices.

Merit factor analysis of polyphaser sequences using cyclic algorithm new with good correlation properties

Polyphase sequences such as Pn (n=1, 2, 3, 4, x), Golomb, Frank, and the Chu are with good correlation properties, lower sidelobe levels and large merit factor values are helpful in applications like radar, sonar and channel estimation and communications. The goodness of a sequence obtained from merit factor. The transmitted and received signal may not be the same due to noise. The correlation function of given sequence is expressed by ISL (Integrated Sidelobe Level) by minimizing the ISL metrics the performance parameter merit factor is improved. To make this possible the ISL metric is expressed in the frequency domain and minimized to its most recent values and fixing at their most recent value until the predefined threshold satisfied. Because of FFT operations, the Cyclic Algorithm New applied to very long length sequences say N~106. In this paper, the Merit factor and correlation levels compared with standard, and cyclic algorithm new initialized with Polyphase sequences for lengths 102~104. Moreover, the observations made for four consecutive even and odd integer lengths say 162, 172, 182, and 192. CAN (P3, Golomb) exhibits merit factor improvement of 3.77%. These sequences of sidelobe levels reduced.