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Purun fiber (PF), which has been used as a raw material for handicrafts, can be used as a filler in composite materials. The purpose of this study is to determine the characteristics of polyester composites with the addition of PF filler at concentrations (5, 10, and 15 %) with arrangements, namely parallel, random, and woven. In this study, the method used was the press molding method with a size of 20 × 20 × 0.3 cm. The resulting composite was analyzed for functional groups, physical properties, morphological properties, mechanical properties, and thermal properties. The functional group results of PF treatment showed a sharp absorption at wave numbers 1724–2983 cm−1, indicating the presence of C=C vibrations in the aromatic ring. For all fiber arrangements, the addition of 10 % PF resulted in the best composite structure. The results of the highest composite physical properties include density, water absorption, and thickness swelling of 0.958 g/cm−3, 10.079 %, and 24.57 × 10−3, respectively. The results of the highest composite mechanical properties are tensile strength, tensile modulus, elongation, and flexural strength of 813.9519 MPa, 9345.737 MPa, 14.06 MPa, and 58.8399 MPa, respectively. While the results of the thermal properties that can be seen from the percent weight loss of the composite obtained the best results in random samples with a variation of 10 %, the effect of the PF filler ratio on composite heat flow obtained the best results, namely in samples parallel to 5 % with a temperature of 500.87 °C. It can be summarized that PF has the potential as a filler in the manufacture of composites.

Waste glass constitutes significant landfill waste, leading to environmental concerns. Considering its chemical composition, glass powder contains 50% to 60% silica, making it suitable for construction materials. Consequently, this community service initiative introduced waste glass as a building material, serving as a partial substitute for sand in construction products. In addition, the activity involved teaching partners how to create castings/road gates utilizing waste glass. The target partners in this activity were productive business groups engaged in selling wind holes, well rings, rosters, and similar products. The approach applied involved socialization and hands-on practices at the partner's premises. The program's success was obtained through interviews and product compressive strength tests with the partners. The outcomes demonstrate the partners' keen interest in the activity, their understanding of the benefits of utilizing waste glass as a partial sand replacement, and their ability to create products. Notably, the compressive strength of the products created with the partners ranged from 24.72 MPa to 30.84 MPa, aligning with the SNI 03-2442-1991 standard for road curbs (30 MPa). The activity positively impacted the partners, enhancing their business prospects and contributing to environmental sustainability. The training helps in enhancing the partners' skills and capabilities.

Glass waste is harmful if it is disposed of and mixed with other waste. A special disposal site is needed to avoid injuring the hands and feet of the garbage collectors, especially at the Final Disposal Site (TPA). Glass waste highly consists of silica (SiO2), which is needed in cement. Glass waste is crushed by a mechanical method using a crusher, creating glass powder with an average size of 54 µm. Cement is mixed with glass powder in a ratio of 4:1. Water cement factor (FAS) is used at 0.3. The partners in this community service activity are primary school-age children in Ateuk Lam Ura Village, Simpang Tiga District, and Aceh Besar District. The success of the resulting product is indicated by its compressive strength, the hardening of cement and glass powder, and the product's visual appearance without any visible pores. The product has good strength and looks neat with a solid surface. The compressive strength of the product obtained is 3.21. Partners are interested and can apply glass waste to flower pots properly.

As an environmentally friendly material, geopolymers are demanded to have good mechanical and fracture strength. Therefore, this research studied the mechanical properties and fracture parameters of geopolymers based on cellulose nanocrystals (CNCs) from typha sp. fibers. The different percentages of CNCs studied were 0%, 1%, 2% and 3%. Various mechanical parameters were evaluated, such as compressive strength, flexural strength, fracture toughness, and direct tensile strength. Microstructures were also evaluated to strengthen the assessment, which included Scanning Electron Microscope (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The results showed that using 1% CNCs was the most effective for improving the mechanical properties, fracture behavior, and microstructural of CNCs-based geopolymers. Using 1% CNCs in geopolymer showed maximum increases of 15.76% and 11.72%, respectively, for compressive strength and tensile strength. Meanwhile, using 1% of CNCs improved flexural strength and fracture toughness up to 3.36 times. The addition of more than 1% CNCs even decreased the mechanical properties of CNCs-based geopolymers. SEM also confirmed that the inclusion of 1% CNCs increased the microstructure and produced a denser structure, and FTIR showed the presence of Si–O–Al bonds. CNCs-based geopolymers from typha sp. fibers can improve mechanical properties and fracture parameters, thus being suitable for reinforcement material and feasible to apply to construction.

Abstrak. Tujuan penelitian ini adalah mengetahui pengaruh konsentrasi ragi, lama fermentasi dan interaksi antara konsentrasi dan lama fermentasi terhadap mutu tempe biji melinjo. Penelitian ini menggunakan Rancangan Acak lengkap (RAL) faktorial dengan dua faktor yang terdiri dari 3 level dengan 2 kali ulangan. Konsentrasi ragi (R) sebanyak 3 level R1 = 1%, R2 = 2%, R3 = 3%. Lama fermentasi (F) sebanyak 3 level F1 = 18 jam, F2 = 24 jam, dan F3 = 36 jam. Hasil penelitian menunjukkan bahwa konsentrasi ragi berpengaruh nyata (P 0,05) terhadap warna dan tidak berpengaruh (P 0,05) nyata terhadap kadar air, kadar protein, rasa, aroma dan tekstur tempe biji melinjo. Lama fermentasi berpengaruh nyata (P 0,05) terhadap kadar air dan kadar protein tidak berpengaruh nyata (P 0,05) terhadap warna, aroma, rasa dan tekstur tempe biji melinjo. Interaksi antara konsentrasi ragi dan lama fermentasi (RF) tidak berpengaruh nyata (P 0,05) terhadap kadar air, kadar protein, warna, aroma, rasa dan tekstur tempe biji melinjo. Perlakuan terbaik pada konsentrasi ragi 1% dan lama fermentasi 24 jam (R1F2) dengan kadar air 69,72%, kadar protein 4,69%, warna 3,90 (suka), rasa 4,08 (suka), aroma 4,03 (suka) dan tekstur 3,95 (suka). The Influence of Yeast Concentration and Fermentation Time on Moisture Content, Protein Content and Organoleptic on Tempeh from Melinjo Seeds (Gnetum Gnemon L) Abstract. The aim of this study was to determine the effect of yeast concentration, fermentation time and interaction between concentration and fermentation time on the quality of melinjo seed tempeh. This study uses factorial completely randomized design (RAL) consisting of two factors and three levels with two replications. Yeast concentrations (R) are R1 = 1%, R2 = 2%, R3 = 3%. The fermentation times (F) are F1 = 18 hours, F2 = 24 hours, and F3 = 36 hours. The results showed that the yeast concentration had a significant effect (P 0.05) on the color and had no effect (P 0.05) on moisture content, protein content, taste, aroma and texture of melinjo seed tempeh. The fermentation time had a significant effect (P 0.05) on the moisture and protein content and had no effect (P 0.05) on the color, aroma, taste and texture of melinjo seed tempeh. The interaction between yeast concentration and fermentation time (RF) did not have a significant effect (P 0.05) on moisture content, protein content, color, aroma, taste and texture of melinjo seed tempeh. The best treatment was obtained at yeast concentration of 1% and 24-hour fermentation time (R1F2) with a moisture content of 69.72%, protein content 4.69%, color 3.90 (likes), taste 4.08 (likes), aroma 4.03 (likes) and texture 3.95 (likes).

Minyak goreng adalah bahan konsumsi yang penting dalam rumah tangga dan industri makanan. Sayangnya, sering digunakan berulang kali karena mahal. Tindakan ini mungkin tidak hanya berbahaya bagi kesehatan manusia, tetapi juga mempengaruhi nilai gizi dan mengurangi kualitas makanan. Kualitas reduksi ditunjukkan dengan meningkatnya jumlah peroksida dan jumlah asam lemak. Penelitian ini menggunakan membran PES yang dimodifikasi dengan penambahan karbon aktif dari kulit biji jarak sebagai aditif untuk mengurangi fouling dalam minyak goreng olahan. Membran diproduksi dengan metode presipitasi perendaman. Sementara, karbon diaktivasi dengan larutan KOH 0,1% dan dipanaskan dalam furnace pada temperatur 600oC.Membran dan karbon aktif dianalisis menggunakan metode FTIR. Analisis SEM menghasilkan membran asimetris dengan lapisan atas berpori dan lapisan bawah padat. Tiga campuran dalam penelitian ini dibuat dengan melarutkan PES yang dimodifikasi dengan karbon aktif pada 0%,3%, dan 5% (b/b) dalam N-methylpirrolidone. Pada penambahan karbon aktif 5% (b/b) dalam campuran membran menghasilkan koefisien permeabilitas tertinggi (L/P) sebesar 9,682 L m2bar-1h-1, pengurangan bilangan peroksida adalah 45% dan pengurangan asam lemak bebas adalah 72% dapat tercapai.

Pineapple crown leaf fiber (PCLF) is one of the major biomass wastes from pineapple processing plants. It consists mostly of carbohydrate polymers, such as cellulose, hemicellulose, and lignin. It can be further processed to form a more valuable and widely used nanocrystalline cellulose (NCC). This study investigates the effect of hydrolysis time on the properties of the produced NCC. The acid hydrolysis was conducted using 1 M of sulfuric acid at hydrolysis times of 1–3 h. The resulting NCCs were then characterized by their morphology, functional groups, crystallinity, thermal stability, elemental composition, and production yield. The results show that the NCC products had a rod-like particle structure and possessed a strong cellulose crystalline structure typically found in agricultural fiber-based cellulose. The highest NCC yield was obtained at 79.37% for one hour of hydrolysis. This NCC also displayed a higher decomposition temperature of 176.98 °C. The overall findings suggest that PCLF-derived NCC has attractive properties for a variety of applications.

The use of biomass as filler in biocomposites are becoming widespread in the present decade because its variety of advantages. Jatropha (jatropha curcas L) seed shell after separated from kernel can be used to produce carbon black because of its higher carbon content, and have the potentiality to use as reinforcement in composites. In this study, carbon black was produced from jatropha seed shell by carbonization in furnace method for 1 hour at 600oC. Thermo gravimetric analysis to analyze seed shell of jatropha as raw material. The morphological properties of the carbon black were analyzed by elemental analysis by X-ray (EDX), SEM, TEM, XRD, SEM, and TEM. It was found that the yield of carbon black was 40% which included 4 different sizes ranging from 70 – 300 mesh in distribution of particle size analysis. Carbon black suggested that it could be a good filler or reinforcement in biocomposites

Asymmetric ultrafiltration (UF) membranes were prepared from three kinds of polymer namely polyacrilonitryle (PAN), polysufone (PS), and cellulose acetate (CA) by phase inversion method. Water was used as non-solvent. These membranes were charachterized for ultrafiltration membranes i.e measurement of solvent permeability (Lp), Molecular Weight Cut Off membranes (MWCO) with various molecular weight of solute dekstran, and morphology of the membrane by Scanning Electron Microscopy (SEM). SEM analysis includes surface area and cross section area. Membranes with polymer low concentration 10% as PAN-1, PS-1 and CA-1 have the larger Lp from PAN-2, PS-2, and CA-2 that have concentration 15% for the same type of polymer. These occur because of the larger pore membrane than high concentration of polymer. SEM analysis showed a homogeneous distribution in the surface membrane and pore of membran like sponge structure from cross section area. Membranes CA-1, CA-2, FS-1 and FS-2 have Molecular Weight Cut off (MWCO) for the solute dextran 40000 Da. For PS-2 and PS-2 membranes have MWCO of dextran above 20000 Da. Keywords: ultrafiltration membrane, solvent permeability coeficient, MWCO, membrane morphology

he increasing use of rare earth elements in high technology industries needs to be supported by developmental work for the separation of elements. The research objective is fiercely attracting and challenging considering the similarity of bath physical and chemical properties among these elements. The rate separation of samarium and yttrium elements using supported liquid membrane has been studied. Polytetrafluoroethylene (PTFE) with pore size of 0.45 µm has been used as the membrane and di(2-ethylhexyl) phosphate (D2EHP) in hexane has been used as a carrier and nitric acid solution has been used as receiving phase. Result of experiments showed that the best separation rate of samarium and yttrium elements could be obtained at feeding phase of pH 3.0, di(2-ethylhexyl) phosphate (D2EHP) concentration of 0.3 M, agitation rate of 700 rpm, agitation time of 2 hours, and nitric acid and its solution concentrations of 1.0 M and 0.1 M, respectively. At this condition, separation rates of samarium and yttrium were 64.4 and 67.6%, respectively. Keywords: liquid membrane, rare earth elements, samarium, yttrium