Electrical And Thermal Properties Of Thecomposite Semiconductors, (Cdse)1-X(Se)X And (Cds)1-X(S)X

A series of (CdSe)1-x(Se)x and (CdS)1-x(S)x composite semiconductors were prepared with different stoichiometric compositions of Se and S with x = 0 to x = 0.8 both in the interval of 0.2 by varying the ratio of CdSe:Se and CdS:S in a reaction mixture. The following powder of CdSe, Se and CdS, S were used as the starting materials. X-ray diffraction analysis was carried out in order to investigate the structural character of the composites obtained. For both samples, analysis of the X-ray diffractogram revealed that the samples were in hexagonal form. Atomic Force Microscopy (AFM) was used for analyzing the surface morphology of the composites samples. Parallel plate method was used to determine the dc conductivity of all samples in the temperature range of 300 – 460 K. Both samples, (CdSe)1-x(Se)x and (CdS)1-x(S)x , show variation in ln σ with 1000/T (K-1) that indicated that there are three distinct temperature zones with three different characteristic regions. This behaviour suggests that two types of conduction mechanisms were presence. The first region is identified as the extrinsic region, the second region is the intermediate region and the third region is the intrinsic region. For both series of samples, the conductivity obtained for all series of samples shown similar trend, the dc conductivity increased as the temperature increased. For (CdSe)1-x(Se)x composite where x = 0, the dc conductivity at 300 K is about 10-8 S/cm and increase up to 10-5 S/cm at 460 K. While for (CdS)1-x(S)x composite where x = 0, the dc conductivity at 300 K is about 10-10 S/cm and increase up to 10-8 S/cm at 503 K. The activation energies were calculated from the Arrhenius relation and the values of the activation energy indicated that all the prepared samples were semiconductors. The ac conductivity properties of polycrystalline (CdSe)1-x(Se)x and (CdS)1-x(S)x were studied in temperature range of 300 – 523 K and frequency range of 100 Hz – 1 MHz using Impedance Analyzer. Obtained data of ac conductivity revealed that at low frequency σAC (ω) was independent of frequency and proportional to ωs at higher frequency for all samples. The values of the frequency exponent, s were found to decrease with increasing temperature which suggested that the dominant transport process as Correlated Barrier Hopping (CBH). Thermal diffusivity values of both (CdSe)1-x(Se)x and (CdS)1-x(S)x were investigated using photoflash technique. Thermal diffusivity value decrease as we increase the Se and S compositions in the samples

Plenitude of mathematics in architecture and its infinite possibilities: a review of parametric design

During the earlier stage of architectural education, we are exposed to the concept of mathematics in architecture such as the Vitruvian man, the golden ratio, the Cartesian, Euclidean and Pythagoras Theorem. After a while this so-called basic architectural knowledge is no longer that matter that we are much consumed by the freedom of art and aesthetic that drove us to oversight that science and technology are also important parts of architecture that we should never overlook. Therefore, this paper explores the use of mathematics in architecture, and how it can contribute in revolutionizing the architecture to a different and logical spectrum. Case studies, site visits and observations are conducted on selected buildings that used applied mathematics in the design process such as British Museum, England (parametric design), Sydney Opera House, Australia (algo rithm design), and Segrada Familia , Spain (sequence number). The paper suggests that it is been retained in a new emerging style of parametricism as the only way for the ideology survive with a better understanding of mathematics as an underlying principle and reasoning

Investigation of bandgap energies of a single phase Zn(₁₋ₓ)CuₓO nanoparticles / Suraya Ahmad Kamil … [et al.]

ZnO nanostructures are extensively studied due to their attractive characteristics and behaviour with wide band gap (3.4 eV) and large exciton binding energy (60 meV) Recently, there have been a lot of interests in studying modified ZnO nanostructures. The prospect of magnetically controlled operation of semiconductor devices has provoked intensive research to develop transition metal doped wide-band-gap semiconductors,i.e. diluted magnetic semiconductors (DMS) with room temperature ferromagnetism. Among transition metals, Cu is an especially interesting dopant because that Cu-related compounds are not strongly ferromagnetic. Transition metal-doped ZnO offers the potential for realizing room temperature operation of active spintronic devices as well as rich and fascinating fundamental physics

Development of TaqMan-based real-time RT-PCR assay based on N gene for the quantitative detection of feline morbillivirus

Background: Morbilliviruses are categorized under the family of Paramyxoviridae and have been associated with severe diseases, such as Peste des petits ruminants, canine distemper and measles with evidence of high morbidity and/or could cause major economic loss in production of livestock animals, such as goats and sheep. Feline morbillivirus (FeMV) is one of the members of Morbilliviruses that has been speculated to cause chronic kidney disease in cats even though a definite relationship is still unclear. To date, FeMV has been detected in several continents, such as Asia (Japan, China, Thailand, Malaysia), Europe (Italy, German, Turkey), Africa (South Africa), and South and North America (Brazil, Unites States). This study aims to develop a TaqMan real-time RT-PCR (qRT-PCR) assay targeting the N gene of FeMV in clinical samples to detect early phase of FeMV infection. Results: A specific assay was developed, since no amplification was observed in viral strains from the same family of Paramyxoviridae, such as canine distemper virus (CDV), Newcastle disease virus (NDV), and measles virus (MeV), and other feline viruses, such as feline coronavirus (FCoV) and feline leukemia virus (FeLV). The lower detection limit of the assay was 1.74 × 104 copies/μL with Cq value of 34.32 ± 0.5 based on the cRNA copy number. The coefficient of variations (CV) values calculated for both intra- and inter-assay were low, ranging from 0.34–0.53% and 1.38–2.03%, respectively. In addition, the clinical sample evaluation using this assay showed a higher detection rate, with 25 (35.2%) clinical samples being FeMV-positive compared to 11 (15.5%) using conventional RT-PCR, proving a more sensitive assay compared to the conventional RT-PCR. Conclusions: The TaqMan-based real-time RT-PCR assay targeting the N gene described in this study is more sensitive, specific, rapid, and reproducible compared to the conventional RT-PCR assay targeting the N gene, which could be used to detect early infection in cats

The effects of structural modifications on the electrical and electrochemical properties of stannum based nasicon structured solid electrolytes / Nur Amalina Mustaffa

In this study, LiSn2P3O12 parent compound was synthesized using water based sol-gel method and the parameters of sol-gel method have been optimized in obtaining minimize impurity of the NASICON compound. Then the effects of structural modifications by partial substitutions using trivalent (Cr3+, Al3+) and tetravalent (Zr4+, Si4+) ions at Sn4+ and P5+ sites on the conductivity and electrochemical properties of the modified NASICON compound were studied. The X-ray diffraction analysis showed that LiSn2P3O12 compound can be indexed to rhomboherdral structure with space group

Silicon substituted lithium stannum phosphate ceramic electrolytes: structural, electrical and electrochemical properties / Noriah Ab Wahab …[et al.]

Structural, electrical, and electrochemical properties of silicon (Si) substituted NASICON-structured lithium stannum phosphate, Li1+ySn2P3- ySiyO12 with 0 < y < 1 that was prepared by the low-temperature waterbased sol-gel method has been investigated. From the structural analysis, all samples in the system from y = 0.1 to 0.5 displayed rhombohedral symmetry. The electrical analysis showed that the total ionic conductivity, was increased with the increase of silicon content, y. A high ionic conductivity value of 6.05 × 10-5 S cm-1 exhibited at y = 0.5 with a temperature of 500 °C. Linear sweep voltammetry analysis of the highest conducting sample showed that the sample was electrochemically stable up to 5.1 V. Meanwhile, the ionic transference number value of the sample was 0.99, suggesting that the majority of mobile charge carriers were predominantly due to ions. Thus, from these results, it indicated that silicon substitution in LiSn2P3O12 ceramic electrolytes is significantly enhanced the electrical and electrochemical properties

Thermal, structural and electrical properties of Li2BaSiO4 ceramic electrolyte

Lithium Barium Silicate (Li2BaSiO4) solid electrolyte was prepared by Sol - gel method with citric acid as the chelating agent. Thermal, structural and electrical characterization was done using Thermogravimetric/Differential Scanning Calorimetry, X-ray Diffraction, Fourier Transform Infrared and Impedance Spectroscopy respectively. Pure phase of Li2BaSiO4 sintered at 700 °C and 800 °C showed stability at that temperature. The conductivity of the electrolyte increased linearly with temperature. The bulk conductivity of the samples sintered at 800 °C was found to be 1.45 × 10−4 S cm−1 at 500 °C. The temperature dependence also follows the Arrhenius relation with activation energy of 0.11 eV. The complex impedance analysis of the electrolyte showed a typical negative temperature coefficient of resistance (NTCR) behavior

Enhancing Photoluminescence Intensity and Spectral Bandwidth of Hybrid Nanofiber/Thin-Film Multilayer Tm3+-Doped SiO2&ndash;HfO2

Multilayering of optical thin films is widely used for a range of purposes in photonic technology, but the development of nanofiber structures that can outperform thin films and nanoparticles in optical applications cannot simply be disregarded. Hybrid structures composed of Tm3+-doped SiO2&ndash;HfO2 in the form of nanofibers (NFs) and thin films (TFs) are deposited on a single substrate using the electrospinning and dip-coating methods, respectively. Ultrafine nanofiber strands with a diameter of 10&ndash;60 nm were fabricated in both single and multilayer samples. Enhanced photoluminescence emission intensity of about 10 times was attained at wavelengths of around 457, 512 and 634 nm under an excitation of 350 nm for NF-TF-NF* hybrid structures when compared with single-layered NF and TF structures. The arrangement of nanofibers and thin films in a multilayer structure influenced the luminescence intensity and spectral bandwidth. High transparency in the range of 75&ndash;95% transparency across the wavelength of 200&ndash;2000 nm was achieved, making it ideal for photonic application. Theoretical findings obtained through IMD software were compared with experimental results, and they were found to be in good agreement