A systematic literature review was conducted to summarize the overall thermal performance of different gasified cooking stoves from the available literature. For this purpose, available studies from the last 14 years (2008 to 2022) were searched using different search strings. After screening, a total of 28 articles were selected for this literature review. Scopus, Google Scholar, and Web of Science databases were used as search strings by applying "Gasifier cooking stove" AND "producer gas cooking stove" AND "thermal performance" keywords. This review uncovers different gasified cooking stoves, cooking fuels, and fabrication materials besides overall thermal performances. The result shows that the overall thermal performance of different gasified cooking stoves was 5.88% to 91% depending on the design and burning fuels. The premixed producer gas burner with a swirl vane stove provided the highest overall thermal performance range, which was 84% to 91%, and the updraft gasified stove provided the lowest performance, which was 5.88% to 8.79%. The result also demonstrates that the wood pellets cooking fuel provided the highest thermal performance and corn straw briquette fuel provided the lowest for gasified cooking stoves. The overall thermal performance of wood pellets was 38.5% and corn straw briquette was 10.86%.
The hardcoat anodising process was done by using different concentration of H2SO4 from 0% to 20%. The 90 volt of anodising process was applied by using Al foil as cathode materials. The surface changes on PM Al-Mg resulted by hardcoat anodising was characterised by XRD measured. Surface hardness was measured by Micro-Vickers hardness machine. The experiment found different XRD pattern between anodised PM Al-Mg samples. The study was found by that the optimum value for H2SO4 concentration was 15 % H2SO4 and result 26 μm thickness, 5.07% of mass changes and HVN 105.4 hardness. The hardcoat anodising was affected to the XRD pattern for PM Al-Mg.
The aim of this study was to produce a high-protein, wet yellow noodle by the incorporation of surimi powder as a protein source and evaluate the effects of the physicochemical and sensory properties of the
noodle. The surimi powder was prepared by oven drying the wet surimi at 60oC until the moisture content was below 10%. Five concentration levels of surimi powder substitutions were used (0, 5, 10, 15 and 20%), and as a result, the noodles showed a trend that significantly increased (P
As the lighting load constituted amount of power in electricity system, improving of efficiency in lighting technology would make a beneficial to consumer, energy provider and environment. Consequently, majority of home lighting manufacturers were competing each other by improving and claiming their product as the best energy efficient lighting product. Knowledge or exposure regarding to lighting technology especially on energy efficiency, power quality and economy are an important issues to give awareness to user before buy or use the lighting product. Therefore in this research study, three types of lighting product such as energy saving incandescent lighting, compact fluorescent lighting (CFL) and solid state lighting (LED) were compared. Comparative parameters were collected from data provided by lighting manufacturer and experimental data conducted in laboratory using power quality meter and lux meter. Hence, these study discussed in term of economy, power and light quality and energy efficiency of the tested lighting product. At the end of this study, the best home lighting technology is determined successfully.
A 2.4 GHz variable-gain low noise amplifier (VGLNA) intended for use in a Wide-band Code Division
Multiple Access receiver was designed in 0.18 um CMOS process for low voltage and low power applications. Rivaling classical designs using voltage mode approach, this design used the current mode approach, utilizing the current mirror principle to obtain a controllable gain range from 8.26 dB to 16.95 dB with good input and output return losses. By varying the current through the widths of transistors and a bias resistor, the VGLNA was capable of exhibiting 8 dB gain tuning range without degrading the noise figure. Therefore, higher gain was possible at lower current and thus at lower power consumption. Total power consumption simulated was 4.63 mW from a 1 V supply and this gave a gain/power quotient of 3.66 dB/mW. Comparing this with available published data, it was observed that this work demonstrated a good gain tuning range and the lowest noise figure with such power consumption.
The glow curve in TLD-100 was compared by applying long preheat time, short preheat time
techniques and without preheat technique before the TLD readout. Fading effect of the TLD signal
upon certain storage time with long preheat time (100°C, 10 minutes using the oven) and short
preheat time techniques (100°C, 10 seconds using the reader) were also studied. 15 TLD-100 chips
were used with 3 of the TLD chips were used for measuring background radiation. 12 TLD chips
were annealed, irradiated, preheated long and short preheat time techniques) and analyzed. The TL
signals output from TLD chips of without preheated were used as the control. Two sets of data were
taken using TLD chips irradiated with 6 MV and 10 MV photon beams. TL signal output was
recorded the highest for short preheat time, followed by long preheat time and no preheating. The
TL signal loss upon certain storage time was also reduced when short preheat time technique was
applied. By applying long preheat time technique the low temperature peak in the glow curve was
completely removed for both energies. Whereas, TLD chips exposed to 6 MV and with short preheat
time technique the low temperature peak did not disappear completely but decreased in intensity as
compared to the control data by 19.80%, 37.69%, 48.19% and 100% at 24, 48, 72 and 96 hours
after exposure prior to readout, respectively. Meanwhile, for 10 MV photon beam with short
preheat time, the small peak intensity was reduced by 19.58% for readout at 24 hours after
irradiation and 100% for 48,72 and 96 hours delayed time prior to readout. It was observed that
the TLD-100 was highly dependent on preheat heating time before readout. Short preheat time
technique was able to reduce post irradiation fading of TLD-100 dosimeters
All relevant and essential data of an existing vehicle seat assembly line such as the operating time and processes, material handling system, workstation layout, bill of materials, equipment and hand tools, were collected and analyzed. The time standards for each of the vehicle seat assembly elements were established using work study techniques. A simulation approach was used to determine the productivity and effi ciency of the existing and proposed lines. Simulation technique was also used to determine and identify bottle-necks in both existing and proposed systems. Comparison of the existing assembly line and the proposed assembly line in terms of their productivity and effi ciency are also highlighted.
Solar thermal system or solar water heater system is one of the applications used to produce hot water in the residential sector. This paper describes HAZOP analysis and reliability assessment to evaluates the potential hazard and system probability for the closed loop solar thermal system applied for the residential area. Hazard identification for the main system components is analyzed while Fault Tree Analysis (FTA), Reliability Block Diagram (RBD) and Weibull distributions performed to determine the reliability for the overall system. The result shows that there are 49 potential hazards for the system with failure probability at 0.23822 and the reliability is 0.9693. Subsequently, this study determined the potential hazards for the system which can be anticipated by the residential consumer for the safety aspect. Furthermore, the evaluated reliability result shows that the application of closed loop type solar water heater system at residential premises is highly recommended due to its long lasting operational condition.
An experimental study was performed to determine the drying characteristics of dried papaya using different drying methods. They were dried using several methods, such as sun drying, solar drying, oven drying, and microwave drying. The effects of different operating conditions on physical quality attributes were investigated. The papaya were cut into different thicknesses and cooked in sugar syrup with different sugar concentration for 24 hours. Three different temperature settings were used in oven and microwave drying. The drying curve and drying rate of each method, temperature, sample
thickness and sugar concentration were studied. The drying times were found as in 6-15 minutes, 5 to 11 h, 10 to 18 h, and 14 to 23 h for the microwave, oven, sun and solar drying, respectively. The drying time increased with the increase of sample thickness and sugar concentration, as well as with the decrease of the drying temperature. In this study, quality attributes like colours and textural property of dried papaya were explored. Among the various methods of the drying characteristics
of papaya halwa, oven drying was preferred with the optimum sample in 5 mm thickness and at the air temperature of 70ºC as it saved up to 40% of the drying time as compared to other methods, except microwave, and produced acceptable physical quality of product.
This paper describes a study on the design, fabrication and testing of a prototype digging device for sweet potato tubers in bris soil. The soil texture was sandy soil (fine sand 94.53%), with mean moisture content of 9.16% and mean bulk density of 1.44 g-cm-3. The soil was prepared in a soil bin. Three types of soil digging tools were designed and fabricated to determine the optimum draft force. These were Flat or plane, V-shaped and Hoe type blades. Plane and V-shaped blades were 30 cm long, and 13 cm wide, while the Hoe type had three rods, 25 mm in diameter, 30 cm long and 6.5 cm wide with sharp cutting edge. The digging tools were tested in a soil bin filled with bris soil to determine the optimum draft force and area of soil disturbance. The results were analysed using statistical analysis of variance (ANOVA). Comparison between all blade types and blade depths to measured draft force and the area of soil disturbed showed that the highest draft of 0.54 kN-m-2 was caused by a flat or plane blade at the optimum depth of 20 cm when the area of soil disturbed was 0.180 m2 . The V-shaped blade had the mean draft of 0.51 kN-m-2, with area of soil disturbance of 0.185 m2 . Thebest choice was V-shaped blade with a rake angle of 30o at 20 cm. depth. The selected blade was fixed onto the sweet potato harvester and tested on bris soil planted with sweet potato of Telong and VitAto varieties. The harvesting efficiency of the machine in bris soil was 93.64% and 90.49% for Telong (Plot A) and VitAto (Plot B) varieties, respectively. The average ground speed and turning time during operation for plots A and B was 0.56 km-hr-1 and 102.7 s and 0.99 km-hr-1 and 81.22 s, respectively. The harvesting efficiencies for both plots showed no significant difference. The total productive time (harvesting time) and unproductive time (turning time) in plot A, at a tractor speed of 0.56 km.hr-1, was 14.8 hours for harvesting a hectare of sweet potato ( 0.068 ha.hr-1). In plot B, the total time for harvesting a hectare of sweet potato was 8.35 hours (0.12 ha.hr-1) at a tractor speed of 0.99 km.hr-1. The average harvesting time for both plots was 11.47 hr.ha-1. The average field work rate was 0.087 ha.hr-1 or 34 man-hr.ha-1 compared to manual harvesting of 150 man-hrs.ha-1.
In recent years, vegetable oil such as Palm Oil (PO) has been identified as a potential alternative dielectric insulating fluid for transformers. It is biodegradable, non-toxic and has high flash and fire points. In this paper, a study on the positive lightning impulse breakdown voltages of PO under non-uniform field is carried out. The testing was carried out using needle-plane electrodes configuration at gap distances of 25 mm and 50 mm. Rising voltage, 1 and 3 shots per step testing methods were used and 3 types of Refined Bleach and Deodorized Palm Oil (RBDPO) and Mineral Oil (MO) were examined. It was found there is no significant effect on the breakdown voltages of all samples. The breakdown voltages of all RBDPO at 50% probability are comparable with MO. At 1% probability and gap distance of 50 mm, the breakdown voltages of all RBDPO are lower than MO.
This paper presents a low-cost method of constructing the compact UV illuminator, which is considered as an important
component of a gel documentation system. The procedure involves using a smallest-possible UV lamp and a motor which
moves the UV lamp in the UV illuminator instead of conventional 4 UV lamps. A comparative analysis of images produced
by using the commercial gel documentation system and our prototype was carried out. These comparisons were done
in real DNA gel as well as a reference plate made of quantum dot. The plate was composed of the chambers filled with
various densities of the quantum dot instead of the Agarose gel containing the ETBR in order to increase the accuracy of
comparison and the convenience of experiments. Despite the use of only 1 UV lamp, the proposed system demonstrated
a similar imaging performance compared with the conventional gel documentation system equipped with 4 UV lamps,
resulting in the great reduction of the system cost.
Tropical or subtropical countries are very suitable for the development of solar and heat pump technology. This paper
proposed the integration of air conditioners that exhaust heat with solar energy to enhance the overall efficiency of thermal
energy conversion. The analysis of thermal storage tanks of different volumes showed that a two-ton air conditioner
operating for an hour produced double energy than normal sunshine for a day. With thermal storage tanks of fixed
volume, the integration of air conditioners of different tons with solar energy indicated that air conditioners of less tons
produced faster and more efficient energy conversion. Therefore, this paper proposed that the modification of condenser
in domestic air conditioner into water-cooled condenser not only enhance the energy efficiency of air conditioners but
also increased hot water supplies since hot water from air conditioners could be integrated into solar water heaters. By
doing so, energy conservation and carbon reduction could be achieved.
Globally, around three billion people depend upon solid fuels such as firewood, dry animal dung, crop residues, or coal, and use traditional stoves for cooking and heating purposes. This solid fuel combustion causes indoor air pollution (IAP) and severely impairs health and the environment, especially in developing countries like Pakistan. A number of alternative household energy strategies can be adopted to mitigate IAP, such as using liquefied petroleum gas (LPG), natural gas, biogas, electric stoves, or improved cook stoves (ICS). In this study, we estimate the benefit-cost ratios and net present value of these interventions over a ten-year period in Pakistan. Annual costs include both fixed and operating costs, whereas benefits cover health, productivity gains, time savings, and fuel savings. We find that LPG has the highest benefit-cost ratio, followed by natural gas, while ICS has the lowest benefit-cost ratio. Electric stoves and biogas have moderate benefit-cost ratios that nevertheless exceed one. To maximize the return on cleaner burning technology, the government of Pakistan should consider encouraging the adoption of LPG, piped natural gas, and electric stoves as means to reduce IAP and adopt clean technologies.
A species of house dust mite, Suidasia pontifica, was recently shown to produce allergens affecting man. The species may be as important as other allergen producing mite in sensitization and causing allergic symptoms in Malaysians. Surveys conducted demonstrated that 80% of the houses surveyed were positive for this mite with densities ranged from 2 to 50 mites per gram of dust. Colonies of the species has been successfully established and materials from those colonies have been used to produce extracts for studies on sensitization to the mites. A total of 85 suspected allergic rhinitis patients were tested and 74.1% demonstrated positive reactions. Extract of this mite should be considered for routine diagnostic testing and possible immunotherapy.
Bunting is a medium to promote advertisements or programs that are widely used in Universiti Putra Malaysia in conjunction with the programs. There are two types of bunting that are commonly used; indoor and outdoor bunting. Outdoor bunting is a bunting that is installed outside of a building and it is usually installed at the street lamp poles, fence or at dedicated space. In UPM, outdoor buntings usually installed at the street lamp poles, around the campus. Issues faced by staff when installing and uninstalling the outdoor buntings are; method used, number of staff needed, time consuming and securities issues. All these factors lead UPM to hire external contractor for installing the outdoor buntings. These issues are also faced by other universities/institutions and external contractors. Several initiatives have been identified in order to mitigate this issues including the implementation of ‘Program Bebas Dawai’, an improvement of Standard Operating Procedure for bunting installation and creation of a new innovation called SkytiderTM. SkytiderTM is an installation tool for outdoor buntings that will expedite method without using ladder, minimize time, improve security measures and save costs by hiring less external contractor. SkytiderTM protected under industrial design, trademark and copyright protection. SkytiderTM is widely used in Serdang Campus, Selangor, Bintulu, Sarawak and Port Dickson, Negeri Sembilan.
Circular 10/2016 issued by UiTM Vice-Chancellor’s office comprises a clear guideline for 2017 Strategic Budget Planning. The guidelines can help the Head of PTJ’s to plan and take necessary cost effective measures to reduce on utility expenditure especially to counter the rising monthly electricity bills related to the use of air conditioners on campuses. Looking at the figures drawn from the energy management office in UiTM Negeri Sembilan Branch, UiTM Kuala Pilah campus has spent an average of RM153, 028.88 monthly in 2016. As of August 2016, the cost of electricity consumption in UiTM Kuala Pilah has reached RM1,224,231.03. This amount has surpassed the overall approved allocation of RM 800,000.00 for 2016 electricity bill. In order to reduce spending and encourage saving, as well as responding to the ‘Energy Savings Campaign’ held at the campus level, various efforts have been taken at the departmental levels. One of the innovative products that came about from the campaign is the ‘Smartfan’ project pioneered by the Physics and Materials Science Unit. The main objective of this project is the production of a “smartfan” or a mini air conditioner which is a simple, cost-effective and an energy saving device. In addition, products and ideas from the campaign can be piloted and taken to innovative, inventions and design contests at national and international levels.
Simulium chayamaritae Takaoka and Srisuka from Thailand belongs to the Simulium darjeelingense species-group of Simulium (Simulium) (Diptera: Simuliidae). The female of this species is described for the first time based on a female reared from a pupa collected from Chiang Mai, Thailand. It is characterized by the sensory vesicle elongate and the inner margins of the arms of the genital fork divergent, then convergent apically. It is similar to the female of S. eshimai Takaoka and Adler of the same speciesgroup from Vietnam. Taxonomic notes are given to separate it from two other species of the S. darjeelingense species-group from India and Malaysia, and 28 of 31 other species of the subgenus Gomphostilbia recorded from Thailand.
The aim of this study is to determine colour changes during storage and physico- chemical properties of peel, core and crown extracts of pineapple variety N36 for maturity indices of 1, 2 and 3. The L* (lightness), a* (redness) and b* (yellowness) values for peels increased significantly (p ≤ 0.05) at each maturity stage during seven days storage. pH of pineapple peel, core and crown extracts were in the range of 3.24 to 3.84. The titratable acidity, percentage of pulp and Total Soluble Solid (TSS) of pineapple peel, core and crown extracts were in the range of 0.16 to 0.36%, 1.37 to 2.91% and 1.4 to 5.3˚Brix, respectively. Fructose and glucose contents were significantly highest (p ≤ 0.05) in pineapple core extract followed by pineapple peel extract and pineapple crown extract for maturity index 2. Significant difference (p ≤ 0.05) was found in sucrose content between pineapple core and peel extracts with 8.92% and 3.87%, respectively for maturity index 3. However, sucrose was not detected in pineapple crown extract. Pineapple core extract was significantly higher (p ≤ 0.05) amount of total sugar content compared to pineapple peel and crown extracts for all maturity indices.
Vapour pressure deficit (VPD) analysis introduces an approach to develop a better basis for the control of the environment of lowland greenhouses in Malaysia. The study of vapour pressure deficit (VPD) is to show air moisture conditions for plant production while taking into account different temperature levels. The purpose of this project is to develop a real-time automatic temperature and relative humidity control system in the lowland tropical greenhouse using a PIC16f876A microcontroller. The controller will then be used to monitor the temperature, relative humidity and VPD in the planting of Chili Kulai (Titisan 15). The fertigation system was introduced to the greenhouse to fertilize and irrigate the plant as well as to provide moisture to the environment. A swamp cooler was used to bring down the temperature and increase moisture content in the greenhouse. Ventilators were installed to remove the heat in the greenhouse. The study was carried out in an experimental greenhouse located at the Institute of Advanced Technology, Universiti Putra Malaysia (UPM).