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"Reaksi thermal dari campuran kaolin dengan magnesium hidroksida dan kaolin dengan magnesium karbonat diamati untuk mendapatkan keramik cordierite tanpa penambahan zat aditif. Komposisi campuran ditentukan berdasarkan rumus molekul 2MgO.2Al2O3.5SiO2. Pembakaran campuran bahan-bahan pada perbandingan mol berdasarkan formula tersebut diharapkan dapat menghasilkan bentuk fasa amorf pada temperatur sekitar 900°C, yang merupakan temperatur dekomposisi. μ-Cordierite kemudian mengkristal pada temperatur sekitar 950°C, dan perlahan-lahan berubah menjadi keramik α-cordierite. Campuran reaktan dipress menjadi benda uji dan dibakar untuk mendapatkan keramik α-cordierite pada temperatur 1300 oC dan 1350°C. Keramik cordierite sebanyak 80,41 - 86,62 % dihasilkan dari campuran kaolin dengan magnesium karbonat dan metakaolin dengan magnesium karbonat pada temperatur pembakaran 1300 oC dan 1350 oC. Uji katalitik dilakukan terhadap cordierite untuk mendekomposisi gas NO, di mana 44,17 % NO terdekomposisi pada temperatur 400°C.

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Thermal reaction of mixed kaolin with magnesium hydroxide and kaolin with magnesium carbonate were studied to produce cordierite ceramic without additives. Its composition was determined based on the molecular formula of 2MgO.2Al2O3.5SiO2. The firing of those mixed materials at mole ratios of this formula was expected to produce μ-cordierite at temperature of 900°C due to its thermal decomposition. The μ-Cordierite was then crystallized at temperature around 950°C, and was gradually transformed into α-cordierite. This study was conducted by prssing the reactants mixtures as specimens which were then fired to obtain α-cordierite ceramic at 1300°C and 1350°C. Cordierite of 80.41-86.62 % were resulted from the mixture of kaolin with magnesium carbonate and metakaolin with magnesium carbonate at the firing temperature of 1300 oC and 1350°C. The catalityc activity of cordierite was tested to decompose NO was tested, in which 44,17% NO could be decomposed at 400°C."

"Carbon Nanotube (CNT) merupakan sebuah material nano yang banyak digunakan pada berbagai aplikasi karena berbagai keunggulan yang dimilikinya. Aligned CNT (ACNT) bahkan dapat meningkatkan performa dari berbagai aplikasi. Namun, pemanfaatan ACNT mengalami hambatan karena ACNT sulit untuk didapatkan. Hal ini disebabkan banyaknya parameter yang perlu diperhatikan. Untuk mendapatkan ACNT, pada penelitian ini dilakukan variasi terhadap substrat, katalis, waktu reaksi dan sumber karbon. Katalis Fe/Mo/MgO dibuat menggunakan metode impregnasi, sehingga katalis terdeposisi pada substrat kaolinite dan vermiculite. CNT dengan diameter yang kecil (12-25nm) berhasil ditumbuhkan pada semua variasi, dengan sumber karbon metana pada reaktor Chemical Vapor Deposition (CVD). Penggunaan substrat vermiculite menunjukkan pertumbuhan beberapa CNT yang mengarah pada terbentuknya ACNT, dimana pertumbuhan tersebut semakin banyak terjadi ketika dilakukan penambahan MgO pada katalis Fe/Mo. Penambahan MgO juga menunjukkan pengecilan diameter CNT, dimana diameter terkecil yang dihasilkan berkisar 12 nm pada perbandingan mol Fe:Mo:MgO sebesar 1:0,46:13. Peningkatan yield CNT terjadi pada peningkatan waktu reaksi menjadi 90 menit, dimana dihasilkan yield sebesar 0,93 gCNT/gKat. Sementara penggunaan etilen menghasilkan yield CNT yang sangat besar (10,5 gCNT/gKat), serta diameter CNT yang besar (150-200nm).

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Carbon Nanotube (CNT) is a nanomaterial that are widely used in various applications due to its advantages. Aligned CNT (ACNT) can even improve the performance of various applications. However, the utilization of ACNT were suspended because ACNT is difficult to be made. There are too many parameters that need to be considered. In order to obtain ACNT, in this research we investigate the effect of substrate, catalyst, reaction time, and carbon source. The Fe/Mo/MgO catalyst be prepared by impregnation, therefore the catalyst was deposited on kaolinite and vermicuite as the substrate. CNT with small diameter (12-25nm) has successfully grown in all variations, with methane as the carbon source in Chemical Vapor Deposition (CVD) reactor. The use of vermiculite substrate showed some CNT growth that leads to the formation of ACNT, where the more growth formation happens after the addition of MgO on Fe/Mo catalyst. The addition of MgO also reduced the diameter of the CNT, which the smallest diameter obtained was around 12 nm with the mol ratio of Fe:Mo:MgO = 1:0.46:13. An increase in CNT’s yield happened on the longer reaction time for 90 minutes, for around 0.93 gCNT/gKat. However, the use of ethylene produced an enormous number of CNT’s yield (10.5 gCNT/gKat), and a large diameter of CNT (150-200nm)."

"Cement column reinforcement is a method of soil reinforcement used in the field to increase soil's shear strength and decrease soil's compressibility. A set of laboratory studies of the effect of cement column reinforcement on shear strength in an undrained condition was conducted on kaolinite clay by using a triaxial apparatus to simulate real conditions. For triaxial testing, the soil samples were made using an extruder. Afterward, to make the composite samples, the soil sample cores were bored to create holes 5 mm in diameter and 50 mm long, and the holes were filled with cement slurry. The soil samples' cement column reinforcements were cured for seven, 14, and 21 days. Then, the soil and composite samples were saturated, consolidated, and applied to the loading. In this test, applying shear force to the soil sample and composite samples was carried out until the maximum stress and a strain of 12% were reached. The results from this test indicated that the cohesion parameter and angle of the internal friction of composite samples are higher and lower, respectively, than the unreinforced soil samples in theconsolidated, undrained triaxial test. It was found that a cement column reinforcement system can improve soil shear strength."

"Pandemi COVID-19 yang disebabkan oleh virus SARS-CoV-2 saat ini tengah melanda seluruh dunia. Virus ini dapat menyebar dengan mudah dan cepat, oleh karena itu diperlukan metode yang cepat untuk mendeteksi virus ini, salah satunya adalah metode RT-PCR. Salah satu tahapan yang penting dari RT-PCR adalah tahap ekstraksi RNA. Tahapan ekstraksi RNA mengalami perkembangan yang pesat, salah satunya dilakukan dengan prinsip ekstraksi fasa padat. Ekstraksi fasa padat salah satunya dapat menggunakan matriks silika. Pada penelitian ini, akan dilakukan ekstraksi asam nukleat menggunakan silika hasil modifikasi dari Kaolin Bangka Belitung dan Bentonit Pacitan. Kaolin dan bentonit akan melalui tahap purifikasi agar didapatkan MMT dan Na-MMT (untuk bentonit) serta kaolin hasil purifikasi dan silika ekstraksi (untuk kaolin). Modifikasi dilakukan dengan membuat kaolin serta bentonit menjadi silica coarse yang dilakukan packing menjadi bentuk kolom ekstraksi (kolom SPE) dan cakram. Modifikasi kolom dan cakram dilakukan terhadap kit ekstraksi komersial. Melalui karakterisasi FTIR, XRD, dan SEM-EDX telah terkonfirmasi bahwa MMT, Na-MMT, kaolin purifikasi, dan silika ekstraksi telah terbentuk. Kolom SPE dan cakram yang sudah dibuat kemudian dilakukan uji performa sebelum dilakukan ekstraksi asam nukleat. Hasilnya adalah semua variasi tidak dapat dilanjutkan karena sudah mengalami kerusakan saat uji performa. Studi literatur kemudian dilakukan untuk menentukan interaksi yang terjadi antara asam nukleat dengan matriks silika dari kaolin dan bentonit. Interaksinya adalah dapat berupa interaksi elektrostatik, interaksi hidrofobik, ikatan hidrogen, pertukaran ligan, ataupun jembatan kation

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The COVID-19 pandemic caused by the SARS-CoV-2 virus is currently sweeping the entire world. This virus can spread easily and quickly, therefore we need a fast method to detect this virus, one of which is the RT-PCR method. One of the important steps of RT-PCR is the extraction stage of RNA. The RNA extraction stage has experienced rapid development, one of which is carried out by the principle of solid phase extraction. One of the solid phase extraction can use a silica matrix. In this research, nucleic acid extraction will be carried out using modified silica from Kaolin Bangka Belitung and Bentonite Pacitan. Kaolin and bentonite will go through the purification stage to obtain MMT and Na-MMT (for bentonite) as well as purified kaolin and extracted silica (for kaolin). Modifications were made by making kaolin and bentonite into silica coarse which was packed into the form of an extraction column (SPE column) and discs. Column and disc modifications are made to commercial extraction kits. Through FTIR, XRD, and SEM-EDX characterization it has been confirmed that MMT, Na-MMT, purified kaolin, and extracted silica have been formed. The SPE column and the disc that have been made are then tested for performance before extracting nucleic acids. The result is that all variations cannot be continued because they were damaged during a performance test. A literature study was then carried out to determine the interactions that occur between nucleic acids and the silica matrix of kaolin and bentonite. The interactions can be in the form of electrostatic interactions, hydrophobic interactions, hydrogen bonds, ligand exchanges, or cation bridges."

"Telah diimobilisasi metilen biru ke dalam lapisan tipis nanozeolit Faujasite (FAU) tipe Y dari kaolin yang ditumbuhkan pada glassy carbon termodifikasi polielektrolit. Lapisan tipis nanozeolit Y disintesis dengan teknik seeding dengan perbandingan komposisi molar 14 Na2O : Al2O3 : 10 SiO2 : 798 H2O : 3 Na2SO4. Keberhasilan sintesis ini diperlihatkan dengan pola XRD zeolit bubuk hasil sintesis yang memiliki kemiripan dengan pola XRD FAU standar. Pencitraan dengan SEM semakin menguatkan bahwa zeolit yang terbentuk merupakan zeolit Y dengan bentuk semi kubus berukuran sekitar 0,8 μM dan memiliki rasio Si/Al sebesar 1,681, rasio ini berada dalam rentang rasio literatur. Namun baik karakterisasi XRD maupun SEM pada glassy carbon termodifikasi lapisan tipis zeolit belum dapat membuktikan bahwa zeolit yang terbentuk merupakan zeolit Y karena memiliki rasio Si/Al sebesar 18,64. Lapisan tipis ini diimobilisasi dengan metilen biru dan digunakan sebagai indikator asam askorbat. Melalui karakterisasi dengan voltametri siklik dapat dilihat respon dari kehadiran metilen biru yang terperangkap dalam NaY. Dari hasil yang didapatkan terlihat bahwa penambahan konsentrasi asam askorbat mengakibatkan arus yang terukur pada puncak oksidasi asam askorbat pada potensial 0,348 V vs Ag/AgCl menjadi semakin besar.

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Methylene blue has been immobilized into a thin layer nanozeolite Faujasite (FAU) type Y from kaolin grown on glassy carbon modified polyelectrolytes. A thin layer nanozeolite Y synthesized with seeding techniques with the molar composition ratio of 14 Na2O: Al2O3: 10 SiO2: 798 H2O: 3 Na2SO4. The success of this synthesis is shown by the XRD pattern of zeolite powders synthesis results which have similarities with the XRD pattern of standard FAU. Imaging with the SEM confirmed that the zeolite is zeolite Y formed by a semi cube measuring approximately 0.8 μM and the ratio Si / Al of 1.681, this ratio is in the range of the ratio of the literature. However, both XRD and SEM characterization of the thin layer of glassy carbon modified zeolite has not been able to prove that the zeolites formed a zeolite Y having a ratio Si / Al of 18.64. This thin layer of immobilized with methylene blue and ascorbic acid used as an indicator. Through characterization by cyclic voltammetry can be seen the response from the presence of methylene blue is caught up in NaY. From the results obtained shows that the addition of ascorbic acid concentration resulted in a measurable current at the peak of ascorbic acid oxidation at a potential of 0.348 V vs Ag/AgCl becomes larger."