RESUMEN
Human activities and climatic elements, including temperature, humidity, and wind speed, have an impact on natural dust deposition. Therefore, this study aims to investigate the effects of wind speed, relative humidity, and ambient temperature on the performance of soiled photovoltaic panels in Al Seeb, Oman. The study was conducted by exposing the solar PV panels to outdoor sunlight for a duration of two months. Parameters such as solar radiation, voltage, current, solar panel temperature, wind speed, relative humidity, and ambient temperature were collected in a short time interval. It was observed that the dust densities of 20.7 g/m2, 27 g/m2, and 41.3 g/m2 resulted in electrical power reductions of 18 %, 33 %, and 40 % for the panels uncleaned for one week, two weeks, and three weeks, respectively. The effect of daily dust resulted in an energy reduction of 14 %. Moreover, dust deposition decreases when the wind speed increases, resulting in a higher power output and vice versa. The higher the humidity, the stronger the dust's adhesion to the surface, resulting in more deposition and reduced power output. The maximum power output of 82.3 W was achieved at the wind speed of 10 m/s, 34.9 % relative humidity, and ambient temperature of 38.5 °C.
RESUMEN
Although starch based materials have an array of fascinating industrial applications, the native starches do not show good mechanical strength, thermal stability, and rheological properties for their use in the mainstream processing industry. For example, the use of starches for producing controlled release fertilizers is a new research endeavor with detailed knowledge still to come. The thermal processing of native starches with water as a plasticizer results in poor physical and pasting properties of the final product. Therefore in this study, corn starch was thermally processed with urea and borate in a water medium. The pure starch (PS), starch-urea (SU), starch-borate (SB), and starch-urea-borate (SUB) samples were prepared and characterized for their rheological traits. The PS sample exhibited a peak viscosity of 299 cP after 17 min of thermal processing. Further heating of the suspension caused a decrease in viscosity of 38 points due to thermal cracking of the starch granules. A similar trend was depicted in the viscosity measurements of SU, SB, and SUB adhesives. However, the viscosity of these samples remained slightly higher than that for PS. Also, the reduction in viscosity after the peak value was not as notable as for PS. The modified starch behaved like a gel and its storage modulus was significantly higher than the loss modulus. The lower magnitudes of storage and loss moduli revealed that the modified starch was in the form of a weak gel and not a solid. The PS is more fluid in nature with dominating loss modulus at lower angular frequencies.
RESUMEN
Oil palm frond biomass is abundantly available in Malaysia, but underutilized. In this study, gasifiers were evaluated based on the available literature data and downdraft gasifiers were found to be the best option for the study of oil palm fronds gasification. A downdraft gasifier was constructed with a novel height adjustment mechanism for changing the position of gasifying air and steam inlet. The oil palm fronds gasification results showed that preheating the gasifying air improved the volumetric percentage of H(2) from 8.47% to 10.53%, CO from 22.87% to 24.94%, CH(4) from 2.02% to 2.03%, and higher heating value from 4.66 to 5.31 MJ/Nm(3) of the syngas. In general, the results of the current study demonstrated that oil palm fronds can be used as an alternative energy source in the energy diversification plan of Malaysia through gasification, along with, the resulting syngas quality can be improved by preheating the gasifying air.