Cellulose-based film has gained popularity as an alternative to synthetic polymers due to its outstanding properties.Among all types of cellulose materials available,cellulose nanofiber(CNF)has great potential to be u...Cellulose-based film has gained popularity as an alternative to synthetic polymers due to its outstanding properties.Among all types of cellulose materials available,cellulose nanofiber(CNF)has great potential to be utilized in a diverse range of applications,including as a film material.In this study,CNF biocomposite film was prepared by using polyvinyl alcohol(PVA)as a matrix and Uncaria gambir extract as a filler.This study aims to investigate the effect of Uncaria gambir extract on the optical properties and thermal stability of the produced film.The formation of the CNF biocomposite films was confirmed using Fourier Transform Infrared Spectroscopy,their transmittance characteristics were measured using UV-Vis spectroscopy and a transmittance meter,while their reflectance was determined using a reflectance meter.The results revealed that the addition of Uncaria gambir extract to the CNF biocomposite film improved its UV-shielding properties,as indicated by the lower percentage of transmittance in the visible region,10%–70%.In addition,its reflectance increased to 10.6%compared to the CNF film without the addition of Uncaria gambir extract.Furthermore,the thermal stability of the CNF biocomposite film with the addition of Uncaria gambir extract improved to around 400℃–500℃.In conclusion,the results showed that CNF biocomposite film prepared by adding Uncaria gambir extract can be a promising candidate for optical and thermal management materials.展开更多
Daylight is one of the essential criteria for decent housing.However,in an urban kampung,access to daylight is limited due to the high-density population in urban Kampung Kota.This study aims to improve the visual and...Daylight is one of the essential criteria for decent housing.However,in an urban kampung,access to daylight is limited due to the high-density population in urban Kampung Kota.This study aims to improve the visual and thermal conditions by modifying the aperture of the light pipe based on visual daylight distribution,illuminance level,and thermal conditions in multi-storey houses in hot-humid climates.Light pipe was developed experi-mentally through the simulation model to investigate the performance and impact on the visual and thermal conditions like operational temperature and RH in densely populated Kampung Kota without vertical apertures.According to the results,the two-aperture light pipe residential space enhanced the current situation but did not fulfill the standards.The two aperture light pipe visually improved daylight distribution by 1.05%-31.36%and illumination level by 8.4%-14.8%.We also found that light pipe also impacts thermal conditions with a 10.92%RH reduction while at the same time increasing temperature up to 10.57%.Therefore,it can be concluded that a two-aperture light pipe has the potential to be applied to actual conditions in hot-humid climates.展开更多
基金funded by the Institute for Research and Community Service(LPPM)Universitas Negeri Padang,Indonesia,with a Contract Number:1529/UN35.15/LT/2023.
文摘Cellulose-based film has gained popularity as an alternative to synthetic polymers due to its outstanding properties.Among all types of cellulose materials available,cellulose nanofiber(CNF)has great potential to be utilized in a diverse range of applications,including as a film material.In this study,CNF biocomposite film was prepared by using polyvinyl alcohol(PVA)as a matrix and Uncaria gambir extract as a filler.This study aims to investigate the effect of Uncaria gambir extract on the optical properties and thermal stability of the produced film.The formation of the CNF biocomposite films was confirmed using Fourier Transform Infrared Spectroscopy,their transmittance characteristics were measured using UV-Vis spectroscopy and a transmittance meter,while their reflectance was determined using a reflectance meter.The results revealed that the addition of Uncaria gambir extract to the CNF biocomposite film improved its UV-shielding properties,as indicated by the lower percentage of transmittance in the visible region,10%–70%.In addition,its reflectance increased to 10.6%compared to the CNF film without the addition of Uncaria gambir extract.Furthermore,the thermal stability of the CNF biocomposite film with the addition of Uncaria gambir extract improved to around 400℃–500℃.In conclusion,the results showed that CNF biocomposite film prepared by adding Uncaria gambir extract can be a promising candidate for optical and thermal management materials.
基金funded by the Directorate of Research and De-velopment,Universitas Indonesia under Hibah PUTI 2022 (grant no.NKB-332/UN2.RST/HKP.05.00/2022).
文摘Daylight is one of the essential criteria for decent housing.However,in an urban kampung,access to daylight is limited due to the high-density population in urban Kampung Kota.This study aims to improve the visual and thermal conditions by modifying the aperture of the light pipe based on visual daylight distribution,illuminance level,and thermal conditions in multi-storey houses in hot-humid climates.Light pipe was developed experi-mentally through the simulation model to investigate the performance and impact on the visual and thermal conditions like operational temperature and RH in densely populated Kampung Kota without vertical apertures.According to the results,the two-aperture light pipe residential space enhanced the current situation but did not fulfill the standards.The two aperture light pipe visually improved daylight distribution by 1.05%-31.36%and illumination level by 8.4%-14.8%.We also found that light pipe also impacts thermal conditions with a 10.92%RH reduction while at the same time increasing temperature up to 10.57%.Therefore,it can be concluded that a two-aperture light pipe has the potential to be applied to actual conditions in hot-humid climates.
