Sri Hidayati^1,*, Eugenia Fonny Budiyanto¹, Hadi Saputra¹, Sutopo Hadi¹, Apri Heri Iswanto^2,3, Nissa Nurfajrin Solihat⁴, Petar Antov⁵, Lee Seng Hua^6,7, Widya Fatriasari^4,8, Mohd. Sapuan Salit⁹

Journal of Renewable Materials, Vol.11, No.6, pp. 2865-2879, 2023, DOI:10.32604/jrm.2023.027579

Abstract Black liquor is obtained as a by-product of the pulping process, which is used to convert biomass into pulp by removing lignin, hemicelluloses and other extractives from wood to free cellulose fibers. Lignin represents a major constituent in black liquor, with quantities varying from 20% to 30%, of which a very low share is used for manufacturing value-added products, while the rest is mainly burned for energy purposes, thus underestimating its great potential as a raw material. Therefore, it is essential to establish new isolation and extraction methods to increase lignin valorization in the development of bio-based chemicals. The aim… More > Graphic Abstract

Vignesh Sekar^1,*, Se Yong Eh Noum¹, Azma Putra², Sivakumar Sivanesan¹, Kok Chun Chin¹, Yi San Wong¹, Dg Hafizah Kassim³

Sound & Vibration, Vol.55, No.4, pp. 343-352, 2021, DOI:10.32604/sv.2021.014916

Abstract This paper presents the development and performance of micro-perforated panels (MPP) from natural fiber reinforced composites. The MPP is made of Polylactic Acid (PLA) reinforced with Oil Palm Empty Fruit Bunch Fiber (OPEFBF). The investigation was made by varying the fiber density, air gap, and perforation ratio to observe the effect on the Sound Absorption Coefficient (SAC) through the experiment in an impedance tube. It is found that the peak level of SAC is not affected, but the peak frequency shifts to lower frequency when the fiber density is increased. This phenomenon might be due to the presence of porosity… More >