Zafri Azran Abdul Majid

Acid blue 25 adsorption on base treated Shorea dasyphylla sawdust: kinetic, isotherm, thermodynamic and spectroscopic analysis.

The potential of base treated Shorea dasyphylla (BTSD) sawdust for Acid Blue 25 (AB 25) adsorption was investigated in a batch adsorption process. Various physiochemical parameters such as pH, stirring rate, dosage, concentration, contact time and temperature were studied. The adsorbent was characterized with Fourier transform infrared spectrophotometer, scanning electron microscope and Brunauer, Emmett and Teller analysis. The optimum conditions for AB 25 adsorption were pH 2, stirring rate 500 r/min, adsorbent dosage 0.10 g and contact time 60 min. The pseudo second-order model showed the best conformity to the kinetic data. The equilibrium adsorption of AB 25 was described by Freundlich and Langmuir, with the latter found to agree well with the isotherm model. The maximum monolayer adsorption capacity of BTSD was 24.39 mg/g at 300 K, estimated from the Langmuir model. Thermodynamic parameters such as Gibbs free energy, enthalpy and entropy were determined. It was found that AB 25 adsorption was spontaneous and exothermic.

Study on electrical power output of floating photovoltaic and conventional photovoltaic

In this paper, several attempt were made to investigate the best electrical performance of a floating photovoltaic (FPV). In photovoltaic (PV) system, the electrical efficiency of the system decreases rapidly as the PV module temperature increases. Therefore, in order to achieve higher electrical efficiency, the PV module have to be cooled by removing the heat in some way. This paper presents study on a conventional photovoltaic (PV) module and floating photovoltaic (FPV) system. The objective of the study is to compare the performance of conventional PV module and FPV. At FPV, an absorber comprises of aluminum flat-box housing was attached to the back of the PV module to absorb heat. Water is used to cool the PV module by passing it under the bottom surface of the module. The system was tested under simulated solar intensity of 417 W/m2, 667 W/m2 and 834 W/m2. Current (I) – voltage (V) curves and power (P) – voltage (V) curves of the results were analyzed. The study found that the FPV has higher efficiency and total power gain than the conventional PV module. The average PV temperature in a FPV might be lower than that for a conventional PV module, thereby increasing its electrical power output. The simplicity of the system structure and aluminum as the chosen material enabled it to reduce the installation costs for a larger scale. Applicable as heat sink, this FPV system is convenient to place on lakes, ponds or rivers.

Variable filtered photographic film as a radiation detector for environmental radiation monitoring

Environmental radiation is an ionising radiation that present in the natural environment which mostly originates from cosmic rays and radionuclide agents in the environment. This may lead the population to be exposed to the radiation. Therefore, the environmental radiation needs to be observed cautiously to minimize the impact of radiation. However, there is no specific or proper monitoring device that provides an outdoor environmental radiation monitoring. Hence, a new outdoor environmental radiation monitoring device was developed. A photographic film has been chosen as a dosimeter. The purpose of this study was to prove the covered photographic film attached with variable filter can be used to develop environmental radiation monitoring device to detect the ionising radiation. The filter used was variable thickness of plastic, aluminium (Al) and lead (Pb). The result from the study showed that the mean optical density (OD) values for medium speed film are in the range 0.41 to 0.73, and for fast speed film the OD values are in the range 0.51 to 1.35. The OD values decreased when the filter was attached. This has proven that the photographic film can be used to detect radiation and fast speed film was more sensitive compared to medium speed film.

Development of a Solar Assisted Drying System Using Double-Pass Solar Collector with Finned Absorber

The Solar Energy Research Group, Universiti Kebangsaan Malaysia, International Islamic University Malaysia and Yayasan FELDA has designed and constructed a solar assisted drying system at OPF FELDA Factory, Felda Bukit Sagu 2, Kuantan, Pahang. The drying system has a total of six double-pass solar collectors. Each collector has a length of 480 cm and a width of 120 cm. The first channel depth is 3.5 cm and the second channel depth is 7 cm. Longitudinal fins made of angle aluminium, 0.8 mm thickness were attached to the bottom surface of the absorber plate. The solar collectors are arranged as two banks of three collectors each in series. Internal manifold are used to connect the collectors. Air enters through the first channel and then through the second channel of the collector. An auxiliary heater source is installed to supply heat under unfavourable solar radiation condition. An on/off controller is used to control the startup and shutdown of the auxiliary heater. An outlet temperature of 70–75 °C can be achieved at solar radiation range of 800–900 W/m2 and flow rate of 0.12 kg/s. The average thermal efficiency of a solar collector is approximately 37%.

Multiparameter double hole contrast detail phantom: Ability to detect image displacement due to off position anode stem

Contrast Detail phantom is a quality control tool to analyze the performance of imaging devices. Currently, its function is solely to evaluate the contrast detail characteristic of imaging system. It consists of drilled hole which gives effect to the penetration of x-ray beam divergence to pass through the base of each hole. This effect will lead to false appearance of image from its original location but it does not being visualized in the radiograph. In this study, a new design of Contrast Detail phantom’s hole which consists of double hole construction has been developed. It can detect the image displacement which is due to off position of anode stem from its original location. The double hole differs from previous milled hole, whereby it consists of combination of different hole diameters. Small hole diameter (3 mm) is positioned on top of larger hole diameter (10 mm). The thickness of double hole acrylic blocks is 13 mm. Result revealed` that, Multiparameter Double Hole Contrast Detail phantom can vi...

Assessment of Double Hole Contrast Detail Phantom for Image Displacement Evaluation

Contrast Detail phantom is used to evaluate the Contrast Detail performance of imaging system. The wall of drilled hole in commercial Contrast Detail phantom will give effect to the penetration of x-ray beam divergence to pass through the base of each hole. This effect will lead to false appearance of image but it does not visualised in the radiograph. In this study, a new design of Contrast Detail phantom’s hole has been developed. The hole feature differs from the current Contrast Detail phantom. The hole consists of combination of different holes diameters, whereby the small hole diameter (3 mm) is placed on top of large hole diameter of different measurements (5 mm, 7 mm and 10 mm). The thickness of double hole acrylic blocks vary from 10 mm, 15 mm, 20 mm, 25 mm and 30 mm. A tiny size of iron which is used as an indicator was placed at the bottom of each holes. Results shows that, as the value of SID values decrease from 2000 mm, 1800 mm, 1600 mm, 1400 mm, 1200 mm, 1000 mm to 800 mm, the size of upper hole image in different thickness of acrylic block increases from the original size (3mm). In different SID setting, variable acrylic block heights (10 mm, 15 mm, 20 mm, 25 mm and 30 mm) which are located at 100 mm from the center show that, the heighest acrylic block visualises the greatest image displacement. Image displacement which occurs due to magnification can be compensated by increasing the level of SID value and also by reducing the height of acrylic block. The increment in image displacement occurs when the hole is situated far from the center of x-ray beam The new design of hole shows the effect of displacement of object from the x-ray focal length in a well manner.

Thermal performance of solar collector with multi direction properties using cross absorber

A solar collector with multi direction properties using cross absorbers has been developed and its performance has been studied. The concept of multi direction is used so that solar radiation can penetrate to the top and sides of the solar collector. In this study, comparison between conventional solar collector (CSC) and solar collector with multi direction properties (SCwMDp) were made whereby SCwMDp was installed with polycarbonate on the side while the CSC will be insulated by using an insulfex type on its side. The experimental setup has been constructed to investigate the thermal performance over a range of the designs and operating conditions. Several important relationships between the designs and operating conditions have been obtained where the effects of mass flow rate, solar radiation, and temperature rises on the thermal efficiency of both solar collectors have been observed. Overall, the SCwMDp is suitable to add or increase the intensity of solar radiation passing through the solar collecto...