Study of synthesis and characterization of bismuth oxyiodide thin film for non- toxic perovskite solar cells

Perovskite solar cells based on lead halide has demonstrated the fast increase in efficiency and advanced in photovoltaic technology in the last decade. However, perovskite solar cells that contain lead (Pb) has high efficiency but tangible risk to humans, animals, and the environment. Bismuth oxyiodide (BiOI) has been recognized as a suitable candidate of non-toxic material to replace lead without adversely impacting performance in perovskite solar cells. The interest in application of BiOI thin films is because BiOI has narrow band gap, high efficiency light absorption and high photo catalytic activity makes it the perfect contender to replace Pb as new non-toxic material perovskite solar cell. Thin films of BiOI were synthesized and deposited using Successive Ionic Layer Adsorption and Reaction (SILAR) on glass substrates. The same mole ratios of bismuth(III) nitrate pentahydrate (Bi(NO3).5H2O) and potassium iodide (KI) were diluted in deionized water to achieve clear solution. The microscope glass was dipped consecutively in 0.01M of (BiNO3)2.5H2O diluted in deionized water, 0.01M of (KI) diluted deionized water and in 50 ml deionized water. This process has been repeated for 30 times and finally the sample was dripped and dried in air. The sample was annealed at various annealing temperature from 250 °C, 350 °C, 450 °C, and 550 °C for 20 minutes. The optical properties and structural properties of BiOI thin films were characterized using X-ray powder diffraction (XRD), Ultraviolet-visible (UV-Vis) measurement and Field Emission Scanning Electron Microscope (FESEM). The Surface Profilometer (SP) was used to measure the thin films thickness. The structure of the films changed with the annealling temperature. The color of the film changes to the orange-yellow and become more yellowish with increasing annealing temperature. The morphology of FESEM images demonstrated that the BiOI thin films have flakes morphology structure with the size around 1μm. The deposited film thickness ranged between 3.479 μm and 8.082 μm. This study provided significant output and a pathway for non-toxic BiOI thin film for perovskite solar cells

Masakan tradisional dan komposisi nutrien ikan air tawar di Homestay Kg Batu Ring, Beng, Lenggong, Perak; untuk pembangunan dan kesejahteraan pelancongan lestari

Konsep pembangunan pelancongan lestari menekankan keprihatinan penggunaan sumber, iaitu pemuliharaan sumber budaya (termasuk warisan) dan alam sekitar (Wanhill, 1997; Mowrorth dan Munt 1998). Makanan tradisonal sesebuah tempat, negeri atau negara merupakan sumber warisan yang seharusnya dipelihara daripada satu generasi kepada generasi yang lain. la juga seharusnya dipekenalkan kepada pe1ancong. Tambahan, apabila berada di sesebuah destinasi pelancongan, setiap pelancong memerlukan makanan dan minuman. Makanan dan minuman adalah salah satu elemen yang penting bagi sesebuah destinasi pelancongan. Mengikut Farzad (2011), salah satu faktor utama dalam pemilihan tempat pelancongan oleh pelancong ialah makanan. Makanan tradisional atau tempatan memainkan peranan yang penting dalam mempromosikan dan meningkatkan daya tarikan sesebuah rantau atau tempat (Skinner, 2002; Van Westering; Poria dan Liapis, 2000)

Experimental investigation of air-conditioning electrical compressor using binary TiO2–SiO2 polyol-ester nanolubricants

As electric vehicles (EVs) continue to replace conventional gasoline vehicles, maintaining thermal comfort within the car requires additional energy to operate the automotive air-conditioning (AAC) system. This work aims to optimise the electrically driven compressor (EDC) system utilising polyol-ester (POE)-based binary nanolubricants to enhance performance and minimise the size of the EV battery and AAC components. A binary nanolubricant was formulated using a two-step method of formulation. The TiO2–SiO2/POE binary nanolubricant was prepared at different volume concentrations ranging from 0.01 to 0.1 %. The experiment was conducted for the 1200–3840 rpm compressor speed with different initial refrigerant charges between 120 and 160 g. The heat absorption rose by up to 44.2 % while utilising the binary nanolubricant at a volume concentration of 0.03 %. The coefficient of performance (COP) reached its maximum value of 2.43 at a refrigerant charge of 160 g and compressor speed of 1860 rpm. Furthermore, the binary nanolubricant significantly reduced the expansion valve discharge temperature, exhibiting a substantial decrease of up to 51.6 %. The highest COP increment, up to 23.4 %, was achieved at a volume concentration of 0.03 %. Hence, it is recommended to utilise 0.03 % TiO2–SiO2/POE binary nanolubricant to achieve optimal performance in the AAC-EDC system

Karsinoma rektum di kalangan pesakit Hospital Kuala Lumpur

A case control study was caried out on 30 patients with rectal carcinoma chosen from the wards of Hospital Kuala Lumpur from January 1991 to June 1994. The purpose of this study was to determine whether diabetes mellitus, hypertension, smoking and the consumption of alcohol were risk factors for rectal carcinoma. The relevant data was obtain from the patient Medical Records. Another 30 patients were chosen as the control group who are free from any cancer. They were chosen at random from the other wards of Hospital Kuala Lumpur. This study found that only smoking is a risk factor for rectal carcinoma

Growth of titanium dioxide nanorod arrays through the aqueous chemical route under a novel and facile low-cost method

Titanium dioxide (TiO2) nanorod arrays were successfully synthesized through a facile aqueous chemical route on a fluorine tin oxide-coated glass substrate in a Schott bottle with cap clamps. Distinct rutile phase TiO2 peaks were observed via X-ray diffraction and micro-Raman spectroscopy. The surface morphology depicted in field-emission scanning electron microscopy and atomic force microscopy images showed that the nanorod arrays were successfully synthesized on the substrate. Moreover, these arrays possessed an average diameter of 120 nm and an average length of 1.52 mm. The prepared TiO2 nanorod arrays exhibited high absorbance properties in the ultraviolet (UV) region (o400 nm). In this study, the synthesized arrays may be applied in optical sensing based on the steady photocurrent results obtained under UV irradiation in a sodium sulfate electrolyte solution

A theoretical analysis of forced convection in a porous-saturated circular tube: Brinkman-Forchheimer model

Fully developed forced convection inside a circular tube filled with saturated porous medium and with uniform heat flux at the wall is investigated on the basis of a Brinkman-Forchheimer model. The matched asymptotic expansion method is applied at small Darcy numbers. For large Darcy numbers, the solution for the Brinkman-Forchheimer momentum equation is found in terms of an asymptotic expansion. Once the velocity distribution is determined, the energy equation is solved using the same asymptotic technique. The results for the two limiting cases of clear fluid and Darcy flow conditions show good agreement with those available in the literature