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Many road pavements have experienced a decline in quality, giving rise to the issue of nanotechnology materials in the construction sector which is expected to overcome this problem. Indonesia, which is the largest palm oil-producing country in the world, needs to utilize its waste, including for pavement materials. The research aims to examine adhesion, and characteristics of asphalt and mastics asphalt based on physical properties, SEM (Scanning Electron Microscope) and contact angles. Palm oil waste was processed into medium-Nano carbon material, then mixed with asphalt cement 60/70 at a temperature of 150ºC and stirred using a high-speed drill for 45 minutes until evenly mixed. The research results show that the carbon Nano material used has an average surface area of 115 nm2 which produces dominant elements of C atoms and S atoms. The low penetration value, high softening point and ductility prove that the ability to increase the strength, temperature resistance and cohesion of mastics asphalt is better than AC 60/70. Apart from that, the medium level of waste used can increase the adhesion of mastics asphalt. This can be seen from the contact angle obtained which is 125.830º which is smaller than using 60/70 asphalt which is 129.258º.

A bio-catalyst made of natural resources, such as Carica papaya latex, is very challenging for nanoparticle separation. In addition, differences in thermal conditions between nanoparticles affect the movement of substances in the separation process. The study experimentally investigated the role of Carica papaya latex bio-catalyst and thermal shock in water on synthesizing rice husk (RH). The synthesis retained the Mg and C elements attached to SiO2, which were generally neglected during the process. The study's objective was to evaluate the effectiveness of biocatalysts and thermal effects on the separation of Mg-SiO2-C from rice husk carbon nanoparticles (CNPs-RH). The research involved various treatment processes, such as RH pyrolysis in obtaining charcoal, High energy milling (HEM) to have carbon particles, and washing to get nano-sized carbon particles. The bonding of elemental compounds to rice husk carbon particles (CPs-RH) was released using NaOH and coagulation using a bio-catalyst. Coagulated CPs-RH was injected into water at a temperature of 60–70 °C to have a thermal shock effect for H2O clusters in Na+ and Mg2+ ions attached to the surface of the nanoparticles. Several tests were carried out, such as the SEM-EDX, TEM, XRD, and FTIR tests, to investigate the two nanoparticle clusters formed up to the nanometer scale. The results indicated that CNPs-RH nanoparticles consist of spherical particles with a diameter of 1.2 nm, while Mg-SiO2-C nanoparticles have a diameter of 0.6 nm. Both are classified as amorphous. Based on the FTIR test, CNPs-RH is hydrophilic, while Mg-SiO2-C is hydrophobic. Thermal shock in water strengthens the ion's mobility, increasing the interfacial dipole forces between nanoparticles and accelerating the separation process.

Biotechnology-based enzymes are challenging in reducing production costs and presenting environmentally friendly technologies. The study deal with an experimental investigation of the bio-catalyst made of Carica-papaya latex in recycling used fibre pulp in industry. The experiments used a test specimen from 5 g of dry pulp mixed with 150 mL of water and a mixture composition of 3.23%. Other similar experiments applied a bio-catalyst from papaya latex by dipping 6 g of unripe papaya into the water. A heating process of the test material was performed at a temperature of 50 °C to optimise the work of enzymes in the pulping process, and then Carica papaya fruit was removed from the container after 3 min. In addition, the characterisation of test materials in the hand-sheets form was realised in dry conditions. The tests carried out include Scanning electron microscope (SEM), Energy-dispersive X-ray spectroscopy (EDX), Fourier Transform Infrared (FTIR) Spectroscopy, acidity (pH), turbidity, whiteness, and freeness. The results indicated that the addition of bio-activator in water produces bio-ions (positive and negative), which play a vital role in eroding pulp functional groups, influencing the construction of stalagmite micro valleys, and changing the surface morphology of pulp. The release of Bromide, Iodide, Chloride and Fluoride functional groups causes brightening effects and increases the degree of whiteness, impacting the pre-whitening process. Meanwhile, changes in the stalagmite micro valley and the surface morphology of the pulp cause a bulky effect and ultimately reduce the degree of freeness.

ABSTRAK Penelitian ini bertujuan untuk mengetahui kualitas bahan yang digunakan pada empat merk bearing (SKF, FMB, NKK, dan JAL) berdasarkan data-data pengujian sifat- sifat mekanik serta struktur intern (struktur mikro) pada benda uji tersebut dan dapat membandingkan ketahanan dan kekuatan keempat merk bearing tersebut berdasarkan analisis pengujian terhadap kegunaannya. Pengujian yang dilakukan meliputi pengujian kekerasan menggunakan alat Micro Vickers Hardness Tester, pengamatan struktur mikro menggunakan alat Olympus Metallurgical Microscope dan Olympus Phtomicrographics Systems, serta pengujian kekasaran permukaan menggunakan alat Surfcorder. Pengujian kekerasan maupun struktur mikro dilakukan pada bagian cincin luar bantalan (outer bearing) dan ball bearing. Sedangkan pengujian kekasaran permukaan hanya pada bagian outer bearing. Setelah dilakukan semua pengujian dapat disimpulkan bahwa berdasarkan kekuatan, kekerasan (ketahanan aus) serta kekasaran permukaan pada bagian outer bearing dan ball bearing maka merk yang memenuhi kualitas optimum adalah merk FMB karena sudah mencukupi dengan parameter kerja bantalan sehingga membuat umur pakai lebih panjang pada aspek penggunaan yang sama. Kata kunci: bearing, kekerasan, struktur mikro, kekasaran permukaan ABSTRACT This study aims to determine the quality of materials used in four bearing brands (SKF, FMB, NKK, and JAL) based on data testing of mechanical properties as well as internal structure (micro structure) on the specimens and can compare the endurance and the strength of the four brands bearings based on the test analysis of its usefulness. The tests include hardness testing using the Micro Vickers Hardness Tester tool, microstructure observation using Olympus Metallurgical Microscope and Olympus Phtomicrographics Systems, and surface roughness testing using Surfcorder tool. Hardness testing and microstructure are performed on outer bearing and ball bearing parts. While the surface roughness testing only on the outer bearing. After all tests, it can be concluded that based on strength, hardness (wear resistance) and surface roughness on outer bearing and ball bearings, the brand that meets the optimum quality is the FMB brand because it is sufficient with the bearing working parameters that make longer life on the same aspect of use. Keywords: bearing, strengthness, microstructure, surface roughness

The paddy husk is often used as material for persevering ice block which means it has good thermal resistance property. The thermal resistance of paddy husk can be used as base for composing new composite material having good thermal resistance property. The material is made by using polyester as binder with composition paddy husk and polyester in 20%, 30%, 40%, 50% and 60% of husk volume fraction. The types of composite manufactured are honeycomb and nonhoneycomb composites. The only test that has been carried out is thermal conductivity property. The thermal conductivity decreases as material temperature increases. In honeycomb composite the decrease of thermal conductivity occurred greater than that in non-honeycomb composite.

Nature composite from skin rice fibre and palm sago fibre have different mechanical and physycs properties characteristic , that have done from result of our researh before. Therefore there is many research that can composse the properties of materials above. The methode of compossing two fiber use poliester that have 20%, 30%, and 40% volume fraction of that matrice, compossing with sandwich layer. Caracterizing properties testing used are thermal conductivity test, and bending test. The result are, at high thermal condition the conductivity was decrease for all above materials. The decreasing of conductivity of this sandwich compsite is more significant. The sandwich composite more tough than skin rice fibre composite. The resume is the mechanical properties ( bending toughness) more less significant of the thermal conductivity that more better.

Tujuan penelitian ini adalah untuk mengetahui pengaruh antara panjang serat pelepah pisang 10 mm, 20 mm, 30 mm, 40 mm terhadap keausan, kekuatan tarik dan impact komposit serat pelepah pisang dengan matrik polyester. Selain itu untuk meneliti jenis-jenis patahan yang terjadi pada pengujian impact dan tarik. Pada penelitian ini serat yang digunakan adalah serat pelepah pisang kepok dengan fraksi volume 50%, panjang serat 10 mm, 20 mm, 30 mm, 40 mm. Proses pembuatan spesimen menggunakan pressmold. Jenis matrik yang digunakan adalah polyester BQTN 157, 1% hardener. Cetakan spesimen menggunakan kaca. Standart acuan untuk pembuatan dan pengujian spesimen yang digunakan yaitu ASTM D 256 untuk pengujian impact dan ASTM D 638-03 type I untuk pengujian tarik, serta untuk pengujian keausan menggunakan metode ’’Ogoshi High Speed Universal Wear Testing Machine’’ (type OAT-U). Dari hasil penelitian dapat disimpulkan bahwa perbandingan panjang serat tidak begitu berpengaruh terhadap kekuatan impact. Spesimen dengan serat yang semakin panjang akan semakin tahan lama dalam menahan beban tarik karena serat yang panjang mempunyai struktur yang lebih sempurna yang terpasang sepanjang sumbu serat dan cacat internal pada serat lebih sedikit daripada material serat yang pendek. Semakin panjang serat maka tingkat keausannya semakin tinggi. Sedangkan serat yang pendek memiliki kerapatan dan kemampuan yang lebih dalam meredam gesekan dibandingkan serat yang panjang sehingga tingkat keausannya relatif rendah. Sehingga serat yang lebih pendek baik digunakan sebagai bahan kanvas rem. Jenis patahan yang terjadi adalah pull out fiber pada spesimen uji impact dan patah getas pada spesimen uji tarik.

Nano-CaO can be used in various fields such as energy, health, and medicine. Clamshell (Geloina sp.) has a large enough CaCO3 content, so it has the potential as a material for making nano-CaO. The synthesis of nano-CaO from shells can be done by the top-down method using high-energy milling. One of the problems with the top-down method is the high energy requirement. The utilization of papaya latex is an effort to reduce energy requirements during the milling process. This study aims to examine the use of papaya latex as a bio-activator in the synthesis of nano-CaO from clamshell (Geloina sp.). Several aspects studied include the yield of nano-CaO obtained and the characteristics of nano-CaO. The results show the optimum conditions for the incubation process with papaya latex were at a temperature of 60 °C, the papaya latex concentration of 5%, and the time of 3 h. The content of Ca, C, and O in nano-CaO is 45.04, 35.07, and 18.36%, respectively. Nano-CaO has a very active group and has antibacterial activity. Therefore, nano-CaO from clamshell (Geloina sp.) can be used in any industrial field. [ABSTRACT FROM AUTHOR]

The aim of this work is to characterize particle of bamboo leaves charcoal produced by ball milling process. The characterization parameter are the particle size and the morphology of the particle. The milling process was completed in a cylinder vial made from stainless steel. The milling element was a steel ball. The dimension of the cylinder vial was 120 mm length and 1 inch diameter, while the ball diameter was 0.25 inch. The charcoal was crushed manually then sieved with a filter size of 200 meshes. The particles passing the filter were then put together with the milling balls into cylinder vial. The cylinder vial was shaken to have ball collision for the size reduction. The shaker machine was operated at 1000 rpm for 2 million cycles. The empty space in the vial was varied for 1/2, 1/3, 1/4 and 1/5 empty space of vial volume. Further work is done to see the effect of the machine speed to the characteristics of particles. The machine is operated at 800 rpm, 900 rpm, 1100 rpm for 1/5 empty space and 0.25 inch ball diameter. Particle size analyzer (PSA) was used to measure average particle size, while Scanning electron microscope (SEM) and Energy Dispersive X-ray (EDX) were employed to see the particle morphology and the content of elements in the bamboo leaf charcoal. The results showed that the average size of particles is in the range of 300 nm to 600 nm. There is no certain relationship between final particle size and percentage of vial volume empty space. The SEM results showed that the particle shape is irregular as a result of fracture due to collision. The most dominant element is carbon which is more than 60% and the second is silicon dioxide (silica) which is more the 20%. [ABSTRACT FROM AUTHOR]