Peningkatan konduktivitas termal lemak sapi sebagai bahan PCM dengan menambahkan arang sekam padi

Phase change material (PCM) is a material that can absorb and store energy and can release it based on the principle of latent heat energy storage. Beef tallow is one of the materials that can be used as PCM but its low thermal conductivity is around 0.181 W/mK. Hence, thermal conductivity is considered an important factor in the conduction heat transfer.  This further affects kinetic absorption and heat release. However it is possible to increase the values by adding another material that has a high thermal conductivity. The purpose of this study is to elevate the thermal conductivity of beef tallow by adding rice husk char. This research involves direct incorporation method, where beef tallow is thawed and mixed with the rice husk char then stirred with a rotation of 100 rpm until the mixture becomes solid. Addition of rice husk char with weight fractions of 5 and 10% and grain size of 0.045 mm. Subsequently, thermal conductivity test was performed using the TQ Heat Transfer Experiment Base Unit.The results show that with the addition of rice husk can increase the thermal conductivity of PCM beef tallow. The increase obtained in the addition of 10% rice husk char is 37 times compared to the pure sample. Based on this result it is concluded that carbon-based materials such as rice husk char can be used to increase the thermal conductivity of PCM materials

Pengaruh minyak zippo pada kecepatan rambatan api dan residu dari komposit epoksi dengan penguat serat jute

This study investigated the rate of flame propagation and residue quality of epoxy composite with jute fiber reinforcement. Three layer of jute fibers were stacked as reinforcement of composites. It was manufactured by the injection method (vacuum assisted injection, VARI). In this study, the zippo oil as flame trigger was added on the specimen. This study aims to investigate the effects of zippo oil on the rate of flame propagation and residue of composites. The flame rate testing was based on ASTM D 635 standard, with repetitions of 5 times for each sample that conducted inside of the combustion chamber. Test results obtained in addition to carbon dioxide (CO2) are carbon monoxide (CO) and methane (CH4), as well as dust particles (PM10). The result of measuring the flame propagation rate with zippo fuel is 0.23 mm/s, while composite without zippo oil is 0.17 mm/s. Furthermore, CO2 residue with zippo oil addition is 1.55% and without zippo oil is 1.57%, respectively. Meanwhile, residual test results for contaminants such as carbon monoxide (CO) and Methane (CH4) from composites with the addition of zippo oil were 0.006 % and 0.008% respectively. In additional, the remaining composite burned without zippo oil has an equal value of CO and methane about 0.002%. The conclusion shows that there was an increase of flame propagation rate and residual value produced after the addition of zippo oil, and that pollutant residues exceeded threshold value

Recent advances in antimicrobial air filter

The worsening air quality has become an environmental issue since it has a serious effect on human health. This is generally attributed to airborne particles including various pathogens and others fine particles. Even though air filters show excellent removal efficiency towards pathogens, the captured microorganism can remain viable in the filter, grow, and re-suspended into an air stream resulting in a secondary source of pollutants. Considerable studies have been conducted to develop air filters which also have antibacterial properties for solving this issue. Results of several studies showed that air filters with antimicrobial activities have been successfully prepared by incorporating inorganic nanoparticles and natural plant extracts. With antibacterial properties, the air filters may be potentially used to control air quality, particularly for indoor spaces e.g. hospitals, by removing fine particles and inhibiting microorganism. In this paper, the recent development of antimicrobial air filter is reviewed. In addition, preparation and performance of developed antimicrobial filters are discussed. Prospects and challenges of antimicrobial air filter are also pointed out

Recent advances in antimicrobial air filter

The worsening air quality has become an environmental issue since it has a serious effect on human health. This is generally attributed to airborne particles including various pathogens and others fine particles. Even though air filters show excellent removal efficiency towards pathogens, the captured microorganism can remain viable in the filter, grow, and re-suspended into an air stream resulting in a secondary source of pollutants. Considerable studies have been conducted to develop air filters which also have antibacterial properties for solving this issue. Results of several studies showed that air filters with antimicrobial activities have been successfully prepared by incorporating inorganic nanoparticles and natural plant extracts. With antibacterial properties, the air filters may be potentially used to control air quality, particularly for indoor spaces e.g. hospitals, by removing fine particles and inhibiting microorganism. In this paper, the recent development of antimicrobial air filter is reviewed. In addition, preparation and performance of developed antimicrobial filters are discussed. Prospects and challenges of antimicrobial air filter are also pointed out