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"EPDM (Ethylene propylene diene monomer) is one of synthetic rubber that widely used in automotive. It must be vulcanized and added by other materials before used. The aim of this study is to investigate the effect of vulcanization system and the addition of carbon black (CB) to the mechanical properties and swelling characteristic of EPDM.This research used three vulcanization system: conventional vulcanization (CV), efficient vulcanization (EV), and semi-efficient vulcanization (SEV) with the variation of carbon black 50, 60, and 70 phr (per hundred resin).This research showed that EV system resulted faster vulcanization time and lower delta torque than SEV and CV systems. This system also performed the highest tensile strength, elongation, and tear strength, while SEV system resulted the highest hardness. Furthermore, the conventional vulcanization system resulted the lowest swelling index."

"The land area and production of rubber on smallholder rubber plantations contribute to about 85% and 81% of national rubber production, respectively. Based on this, having technology to utilize vulcanized natural rubber latex (NRL) in a way that is simple, inexpensive, energy-saving, environmentally friendly, and according to the quality standards of the processing of NRL is important. The purpose of the current research is to design of a prototype photoreactor ultraviolet light-emitting diodes (UV-LEDs) for the vulcanization of NRL that is irradiated (VNRLI) to produce NRL-irradiated free carcinogens and protein allergens. The methodology used is the technological development of a prototype photoreactor with an UV-mercury irradiator that located in a vertical cylindrical glass column with the capacity of VNRLI about 249.2 tons/year. The development of technologies applied to increase the capacity of VNRLI by enlarging the area of thin NRL films to be irradiated with UV-A rays derived from UV-LED irradiators that are more energy-efficient, long-life, and environmentally friendly than UV-mercury irradiators. The results allowed for the design of a prototype photoreactor UV-LEDs to process feed NRL with the capacity VNRLI about 522 tons/year. The UV-LED photoreactor prototype design results show that the UV-LED photoreactor prototype is ready to test the VNRLI process function that can produce NRL- irradiated free carcinogen and protein allergens."

"Karet alam merupakan salah satu komoditas terbesar yang ada di Indonesia. Kondisi tersebut mendorong perkembangan pesat industri karet. Namun rendahnya modulus kekakuan karet alam menjadi kelemahan dari produk karet alam contohnya ban kendaraan dimana akan menghasilkan sifat yang buruk sehingga berpengaruh kepada umur pakai ban tersebut. Untuk mengkompensasi modulus kekakuannya yang rendah, biasaya karet alam ditambahkan penguat yaitu silica atau carbon black. Tetapi kedua bahan tersebut memiliki kelemahan dimana harganya yang mahal. Alternatif yang dapat digunakan adalah dengan menggunakan penguat berupa serat sorgum. Permasalah kompatibilitas antara karet alam dan sorgum yang memiliki sifat permukaan berbeda menjadi hambatan dalam modifikasi ini. Permasalahan kompatibiltas tersebut dapat diatasi dengan penggunaan coupling agent yang dibuat dari hibrida lateks-pati. Coupling agent merupakan senyawa yang digunakan untuk meningkatkan adhesivitas antara dua material yang berbeda. Pengamatan terhadap perilaku alir vulkaniasi dan kompatibilitas karet alam berpenguat serat sorgum dengan penambahan coupling agent berbasis pati dilakukan untuk dapat mengamati kinetika vulkanisasi. Hasil perilaku alir menunjukkan kenaikan torsi maksimum (MH) dan torsi minimum (ML) serta penurunan waktu pematangan optimum (t90) dan waktu scorch (ts2) dengan adanya penambahan coupling agent berbasis pati. Didapat pula optimasi vulkanisasi pada komposisi coupling agent sebesar 3 phr dan temperatur 150oC. Penambahan coupling agent berbasi pati juga berpengaruh kepada kenaikan nilai laju reaksi dan penurunan energi aktivasi dalam proses vulkanisasi. Hasil karakterisasi menunjukan penambahan coupling agent meningkatkan absorpsi ikatan hidrogen O-H serta menurunkan fiber pull-out dan meningkatkan dispersi yang mengindikasikan kompatibilitas karet alam dengan sorgum meningkat.

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Natural rubber is one of the largest commodities in Indonesia. This condition encouraged the rapid development of the rubber industry. However, the low modulus of natural rubber has become a weakness of natural rubber products, for example vehicle tires which will produce bad properties which affect the life of the tire. To compensate for the low modulus of stiffness, reinforcement is usually used, which are silica or carbon black. But both of these materials have weaknesses where the price is expensive. The alternative is to use sorghum fiber as a reinforced.

Problems of compatibility between natural rubber and sorghum which have different surface properties are obstacles in binding. The compatibility problems can be overcome by using a coupling agent made from a hybrid of latex-starch. Coupling agent is a compound used to increase adhesivity between two different materials. Observations on the behavior of vulcanization and compatibility of natural rubber reinforced with sorghum fibers with the addition of starch-based coupling agents were carried out to be able to observe vulcanization kinetics.

The results of the flow behavior show the increase in maximum torque (MH) and minimum torque (ML) and decrease in optimum ripening time (t90) and scorch time (ts2) with the addition of starch-based coupling agents. Optimization of vulcanization was also obtained on the composition of coupling agent by 3 phr and temperature of 150oC. Addition of starch-based coupling agent also influences the increase in reaction rate and decrease in activation energy in the vulcanization process.

The characterization results show that the addition of coupling agents increases the absorption of O-H hydrogen bonds and decreases fiber pull-out and increases the dispersion which indicates the compatibility of natural rubber with sorghum increases."

"EPDM dan NR merupakan polimer yang tidak misibel dan kompatibel. Penambahan kompatibiliser maleat anhidrat diharapkan menghasilkan campuran yang kompatibel dengan sifat mekanik yang baik. Pencampuran EPDM dan NR dilakukan menggunakan alat two roll mill, dengan rasio EPDM/NR adalah: 100/0, 80/20, 70/30, 60/40, 50/50, dan 40/60 phr. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh rasio EPDM/NR terhadap sifat reologi, aging, termal dan swelling dari campuran EPDM/NR. Hasil penelitian menunjukkan penambahan NR mempengaruhi torsi maksimum, waktu scorch dan waktu vulkanisasi optimum. Penambahan EPDM memberikan sifat aging, termal dan swelling lebih baik.

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The blends of EPDM and NR are immiscible in nature and incompatible. Introducing maleic anhydride as a compatibilizer into the blends was expected to produce compatible blends with balanced mechanical properties.

The purpose of this research was to determine the effect of EPDM/NR ratio on the rheological, aging, thermal and swelling properties of the blends. The variation of EPDM/NR ratio were 100/0, 80/20, 70/30, 60/40, 50/50, and 40/60 phr. The blends were mixed using two roll mill.

The results showed that the addition of NR affects the maximum torque, scorch time, and optimum vulcanization time. In the blends, EPDM plays an important role in improving aging, swelling, thermal properties."

"The production and/or worldwide consumption of chicken at an industrial or domestic level lead to a considerable quantity of chicken feather residue as a waste by-product. Chicken feathers have a possible application in preparing lightweight composites. The use of chicken feathers as a constituent to prepare hybrid composites leads to a solution for disposal of the feathers. In this study, chicken feathers were used as filler material to prepare hybrid composites. Different varieties of composites were prepared by a chicken feather hand-layup technique, and by varying the percentage weight of the chicken feathers. Specimens were prepared and tested according to ASTM standards. The 10 wt. % chicken feather-filled hybrid composites indicated the maximum tensile strength (193 MPa), flexural strength (148 MPa) and impact strength (3.65 Joules). Scanning Electron Microscopy (SEM) analysis was carried out to find the fracture and interfacial characteristics of the composites. The results indicated that, these composites can be used in domestic, automobile and structural applications which carry nominal loads."

"Penggunaan komposit sandwich dalam berbagai aspek kehidupan semakin meningkat belakangan ini. Komposit sandwich banyak digunakan karena mempunyai rasio modulus terhadap berat yang tinggi, rasio kekuatan terhadap berat yang tinggi, ketahanan aus, hingga ketahanan terhadap korosi. Penelitian ini bertujuan untuk membandingkan pengaruh teknik fabrikasi yang digunakan terhadap sifat mekanik komposit sandwich. Komposit sandwich dibuat dari serat gelas anyam dan resin poliester tak-jenuh sebagai kulit dan busa poliuretan kaku sebagai inti menggunakan dua teknik fabrikasi yakni adhesive-cold press dan Vacuum Assisted Resin Infusion (VARI). Pada komposit sandwich kemudian dilakukan uji tarik, uji tekan, uji lentur, dan uji densitas. Untuk komposit sandwich yang difabrikasi dengan teknik adhesive-cold press, didapatkan nilai kuat tarik, kuat tekan, kuat lentur dan densitas berturut-turut sebesar (1,55 ± 0,01) MPa, (1,30 ± 0,01) MPa, (11,04 ± 0,45) MPa, dan (0,29 ± 0,01) g/cm3. Sementara itu, untuk komposit sandwich yang difabrikasi dengan teknik VARI, didapatkan nilai kuat tarik, kuat tekan, kuat lentur dan densitas berturut-turut sebesar (2,25 ± 0,42) MPa, (1,41 ± 0,01) MPa, (13,84 ± 0,42) MPa, dan (0,33 ± 0,01) g/cm3. Hasil ini menunjukkan bahwa sifat mekanik dari komposit sandwich yang difabrikasi dengan teknik VARI lebih tinggi dari pada yang difabrikasi dengan teknik adhesive-cold press. Tidak ada perbedaan mode kegagalan yang terjadi pada kedua tipe komposit sandwich. Untuk uji tarik dan tekan, mode kegagalan yang terjadi adalah kerusakan inti busa, sedangkan untuk uji lentur adalah kerusakan kulit bagian atas. Hal ini menunjukkan bahwa ikatan inti dan kulit dengan kedua teknik sangat baik.

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The use of sandwich composites in various aspects of life has increased lately. Sandwich composites are widely used because of their high modulus-to-weight ratio, high strength-to-weight ratio, wear resistance, and corrosion resistance. This study aimed to compare the effect of the fabrication techniques used on the mechanical properties of sandwich composites. The sandwich composites were fabricated from woven glass fiber reinforced unsaturated polyester resin as skin and rigid polyurethane foam as core using two fabrication techniques, namely adhesive-cold press and Vacuum Assisted Resin Infusion (VARI). The sandwich composites were then tested for tensile, compressive, flexural, and density tests. For the adhesive-cold pressed sandwich composites, the values of tensile strength, compressive strength, flexural strength, and density were (1.55 ± 0.01) MPa, (1.30 ± 0.01) MPa, (11.04 ± 0.45) MPa, and (0.29 ± 0.01) g/cm3, respectively. Meanwhile, for the VARI fabricated sandwich composites, the values of tensile strength, compressive strength, flexural strength, and density were (2.25 ± 0.42) MPa, (1.41 ± 0.01) MPa, (13,84 ± 0.42) MPa, and (0.33 ± 0.01) g/cm3, respectively. These results indicated that the mechanical properties of sandwich composites fabricated with the VARI technique were higher than those fabricated with the adhesive-cold press technique. For the tensile and compressive tests, the failure mode was foam core failure, while for the flexural test was upper skin failure. These results indicated that the bonding of the core and skin with both techniques is excellent."

"Serat tandan kosong kelapa sawit (TKKS) merupakan limbah tanaman kelapa sawit yang berlimpah di Indonesia. Serat ini merupakan serat alam yang dapat digunakan sebagai penguat di dalam komposit polimer, namun masalah utama dari serat alam adalah hidrofilik sedangkan polimer propilena sebagai matriks adalah hidrofobik. Perlakuan kimia alkalinisasi merupakan perlakuan kimia yang dapat meningkatkan kompatibilitas serat dan sifat mekanis yang dihasilkan pada pembentukan komposit. Metode pengujian yang dilakukan untuk mengetahui bentuk serat di dalam struktur komposit menggunakan Scanning Electron Microscope (SEM) dan kemudian diolah menggunakan perangkat lunak ImageJ. Alkalinisasi dapat meningkatkan distribusi serat di dalam komposit dinyatakan dalam bentuk rasio distribusi hingga 0,42 pada serat 50 mesh dan 0,40 pada serat 100 mesh. Selain itu, kompatibilitas serat juga meningkat ditunjukkan oleh selisih tegangan permukaan yang menurun hingga 1.60 mN/m. Hasil pengujian dibentuk dalam purwa-rupa aplikasi sebagai contoh manfaat mengetahui pengaruh secara kuantitatif yaitu dapat memprediksi sifat-sifat yang dihasilkan.

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Oil Palm Empty Fruit Bunch (OPEFB) Fiber is an abundant waste in Indonesia. This fiber is a natural fiber that can be used for reinforcement in polymer-based composites, but natural fiber is hydrophilic while polypropylene as a matrix are hydrophobic. Alkalinization is a type of chemical treatment that can improve fiber compatibility and mechanical properties resulting in the formation of composites. Testing methods conducted to determine the shape of the fibers in the composite structure are using Scanning Electron Microscope (SEM) and then processed using ImageJ software. Alkalinization can increase fiber distribution in composites expressed in the form of distribution ratio up to 0,42 for 50 mesh and 0,40 for 100 mesh. In addition, the compatibility of the fiber also increases, indicated by the differences in surface tension decreased to 1,60 mN/m. The test results are formed in the prototype of application that can be used for an example of the benefits of knowing the influence quantitatively so that can be able to predict the resulting properties.

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"Pada sistem transnmisi long-haul fiber optik yang menggunakan input daya yang tinggi dan memiliki jarak transmisi yang jauh, gangguan-gangguan dapat terjadi selama proses propagasi. Gangguan-gangguan ini dapat dikategorikan menjadi efek linear dan non-linear yang dipengaruhi oleh kebergantungan intensitas terhadap medium indeks n. Efek-efek ini dibagi terbagi menjadi beberapa orde dan dianalisa secara terpisah karena setiap orde memiliki efek yang berbeda satu sama lain. Pada penelitian ini, dispersi yang menjadi bagian dari efek linear dan beberapa efek non linear akan dianalisa. Secara lebih spesifik, fokus utama dari paper ini adalah keberadaan pulse broadening, pulse oscillation, dan evolusi spektral yang terjadi di dalam pulsa signal. Pendekatan yang baru mengenai pemodelan metode orde tinggi dari NLSE diajukan untuk menjadi topik pembahasan skripsi ini untuk mendeteksi dan menganakusa efek-efek tersebut. Skema baru ini menggunakan high orders sequence, SSFM, dan Symmetrized SSFM yang akan digunakan untuk menganalisa setiap orde di dalam NLSE. Skema baru ini didasarkan kepada deret orde tinggi dari NLSE yang akan digunakan untuk mengklasifikasikan efek-efek dari parameter-parameter yang ada. Selanjutnya, beberapa metode chirping dari setuap input pulsa juga akan didiskusikan untuk mengkomparasi pulsa yang sudah ataupun belum diberlakukan efek chirping. Sehingga ditemukan bahwa metode chirping juga mempengaruhi hasil dispersi karena kebergantungan dari parameter-parameter-parameter orde tinggi NLSE terhadap metode chirping. Selain itu ditemukan pula bahwa hasil terbaik untuk simulasi berada pada nilai rata-rata PBR yaitu 2,4833 untuk nilai variabel non linear yang tetap, 1,8944 untuk nilai tetap, dan nilai intensitas fiber sebesar 2,433 a.u pada 0,1 untuk TOD. Analisa lebih lanjut terhadap hasil simulasi MATLAB juga dijabarkan di dalam tugas akhir ini.

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In a long-haul optical fiber transmission system which uses a high power input and a long distance transmission, disturbances can occur during the propagation process. These disturbances can be categorized into linear and non-linear effects which are affected by the intensity dependence of fiber optic refractive index n . These effects are divided into several orders and analyzed separately since each of the orders has different effects. In this research, dispersion which is part of the linear effect and some of the non linear effects are analyzed. More specifically, the main focus of this paper will be on the phenomena of pulse broadening, oscillation and spectral evolution that occur within a signal pulse. A novel approach which is based on the modeling of high order method of NLSE, SSFM, and Symmetrized SSFM within the modelled equation were proposed in this final project in order to detect and analyze those effects. This new scheme is based on the high order sequence of NLSE which will be used to classify the effects of the parameters. Furthermore, various chirping methods for each input pulse were also discussed to compare the chirped and unchirped pulses. Consequently, it was found that the chirping method affected the dispersion result due to the dependencies of high order parameter with respect to the chirping constants and the best result of PBR found in the average of 2,4833 for constant non linearity variabel, 1,8944 for constant variabel, and 2,433 at 0,1 for best intesity fiber in TOD. Further analysis of the MATLAB results is also presented in this paper based on each output."

"ABSTRAKTersedianya serabut kelapa di Indonesia dalam jumlah yang besar dapatdimanfaatkan pada dunia konstruksi, salah satunya adalah batu bata sebagai material bangunan yang dapat di fungsikan secara struktur maupun non struktur. Berdasarkan hal tersebut, dilakukan penelitian mengkaji sifat fisik dan mekanik batu bata tidak dibakar yang dicampur serabut kelapa. Sifat mekanik yang diuji antara lain adalah kuat tekan dan kuat lentur, kemudian sifat fisik yang diuji antara lain adalah susut, absorbsi, densitas, dan kadar air. Campuran bata adalah tanah lempung, pasir, semen, air, dan serabut kelapa. Serabut kelapa yang digunakan berukuran panjang 4 cm dan 2,5 cm, masing-masing panjang memiliki persentase serabut 2%, 4%, dan 6% dari massa semen. Kondisi penyimpanan batadengan panjang serabut 4 cm adalah di dalam ruang, sementara bata dengan panjang serabut 2,5 cm adalah di ruang terbuka. Pengunaan serabut kelapa, menunjukan bahwa bata dengan serabut kelapa lebih baik dibandingkan dengan bata tanpa serabut kelapa. Hasil pengujian menunjukan bahwa bata dengan panjang serabut 4 cm secara keseluruhan lebih baik dibandingkan bata dengan panjang serabut 2,5 cm. Persentase serabut kelapa paling optimal adalah 2%, baik pada bata dengan panjang serabut 4 cm maupun 2,5 cm.

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ABSTRACTIn Indonesia coconut fibers (coir) are available in large numbers. In the construction world, one kind of building materials that benefit of this situation is brick. The bricks can be used as structural and non structural members. This study was conducted in order to assess the physical and mechanical properties of unfired bricks added by coconut fibers (coir). Mechanical properties were obtained by compressive and flexural test, then their physical properties such are shrinkage, absorption, density, and water content were also observed. Tests performed on a mixture of clay bricks, sand, cement, water, and coconut fibers. Coconut fibers were cut and grouped to length of 4 cm and 2,5 cm. Respectivelythose 2 fibers have a percentage of 2%, 4%, and 6% of the cement mass. Storageconditions of the brick with 4 cm long fibers are in the room, while the brick withfiber length of 2,5 cm is placed in open space with roof. The use of coconut fibers shows that mechanical behavior of the brick with coconut fibers was better than that of a brick without coconut fibers. The test results also showed that the bricks with 4 cm long fibers in general perform better than a brick reinforced with 2,5 cm fibers. Optimal percentage of coconut fibers addition is 4%, either in bricks reinforced with fibers with a length of 4 cm or 2.5 cm."

"ABSTRAKBambu sebagai salah satu serat alam yang ada di Indonesia berpotensi menjadi penguat pada komposit yang ramah lingkungan. Penelitian ini dilakukan untuk menentukan jenis komposit dan kuat lengkung dari komposit polipropilena/serat Bambu Tali (PP/SBT) sesuai dengan SNI 01-4449-2006 untuk papan serat dan kekeraannya. Serat Bambu Tali diberi perlakuan alkali sebelum dijadikan penguat komposit. Single Fiber Test dan analisa FTIR dilakukan pada serat Bambu Tali sebelum dan sesudah proses alkalisasi. Fabrikasi komposit menggunakan mesin ekstruder dengan variasi fraksi berat serat Bambu Tali 10wt%, 20wt%, dan 30wt%, dengan ukuran serat 0.5 mm. Uji lengkung dan kekerasan dilakukan pada komposit dan polipropilena murni, dan pengamatan Scanning Electron Microscope (SEM) dilakukan pada permukaan patahan uji lengkung. Hasil uji lengkung dan densitas menunjukkan bahwa komposit PP/SBT merupakan tipe Papan Serat Kerapatan Tinggi (PSKT) T1, dengan modulus lengkung dan kuat lengkung terbaik pada PP/SBT 30wt% masing-masing yaitu (79,01±4,47) GPa dan (36,97±3,03) MPa. Nilai ini meningkat 15,5% dan 25,6% dari polipropilena murni. Nilai uji kekerasan terbaik pada komposit PP/SBT 30wt% yaitu (61,86±0,67) HD yang meningkat 26% dari nilai kekerasan polipropilena murni. Hasil pengamatan SEM terlihat patahan serat terjadi pada permukaan patahan uji lengkung.

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ABSTRACT

Bamboo as one of the natural fibers in Indonesia has the potential to become an environmental friendly composite reinforcement. This study was conducted to determine the density of composite and bending properties of polypropylene/Tali Bamboo fiber (PP/TBF) composites in accordance with SNI 01-4449-2006 for fiberboard and their hardness. Tali Bamboo Fiber was treated with alkali before being fabricated. Single Fiber Test and FTIR analysis were conducted on Tali Bamboo fibers before and after the alkalization process. Composites were fabricated using an extruder machine with variations in the weight fraction of Tali Bamboo fiber i.e 10wt%, 20wt%, and 30wt%, with a fiber size of 0.5 mm. Bending and hardness tests were carried for composites and pristine polypropylene ; fracture surfaces after bending test were ensured using Scanning Electron Microscope (SEM). The density and bending test results showed that all PP/TBF composites were categorized as Papan Serat Kerapatan Tinggi (PSKT) T1 type. PP/TBF30 composites had the highest bending modulus and strength of (79.01±4.47) GPa and (36.97±3.03) MPa respectively. These values increased 15.5% and 25.6% compared to the pristine polypropylene. The highest hardness value belong to PP/TBF30 i.e (61,86±0.67) HD, in which increased 26% from the value of pristine polypropylene hardness. SEM observations showed that fiber failure occurred on the fracture surfaces after bending test.

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