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Abstrak :
ABSTRAK
Batasan rasio komposisi Cu : Mg yang mengalami fenomena rapid hardening pada paduan Al-Cu-Mg masih belum diketahui secara pasti. Selain itu juga, pengaruh komposisi Cu dan Mg pada rentang yang lebar terhadap respons penuaan belum pernah diamati dengan rinci. Penelitian ini mengamati pengaruh variasi komposisi Cu dan Mg pada fenomena rapid hardening dan respons penuaan pada paduan Al-Cu-Mg. Karakterisasi meliputi pengujian kekerasan Vickers dan pengamatan mikrostruktur dengan menggunakan mikroskop optik, SEM/EDS (Scanning Electron Microscopy/Energy Dispersive Spectroscopy), dan TEM (Transmission Electron Microscopy). Hasil menunjukkan bahwa peningkatan komposisi Cu dan Mg memperkecil ukuran butir dan meningkatkan fraksi volume partikel intermetalik yang terbentuk. Pada rentang komposisi Cu (1.1-3.0 at.%) dan Mg (1.7-3.5 at.%) yang lebar, pada paduan Al-Cu-Mg, batas rasio terjadinya fenomena rapid hardening belum dapat ditentukan dengan tepat. Komposisi dimana terjadi fenomena rapid hardening pada penuaan temperatur 170 oC ternyata fluktuatif. Pada saat rapid hardening (waktu penuaan 60 detik), loop dislokasi merupakan satu-satunya mikrostruktur yang ditemukan, sementara pada saat kekerasan puncak, ditemukan presipitat fasa S.

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ABSTRACT
The range of Cu : Mg ratio in Al-Cu-Mg alloy which undergoes rapid hardening has not been clearly understood. The ageing response on this alloy with wide Cu : Mg ratio has not been fully evaluated. This study observed the effect of Cu : Mg ratio on rapid hardening and ageing response of Al-Cu-Mg alloys. Characterization included Vickers Hardness Testing and Microstructural Observation by using Optical Microscope, SEM/EDS (Scanning Electron Microscopy/Energy Dispersive Spectroscopy), and TEM (Transmission Electron Microscopy). The results showed that the higher the Cu and Mg content, the smaller the grain size and the higher the volume fraction of intermetallic particles. Within the range of 1.1-3.0 at.% Cu and 1.7-3.5 at.% Mg, the Cu : Mg ratio at which rapid hardening occurred, was not able to define. The data was fluctuative at the ageing temperature of 170 oC. After rapid hardening (for 60 seconds of ageing), dislocation loops were observed. While at the peak hardness, the microstructure was strengthened by S precipitates.

Abstrak :
[ABSTRAK
Indonesia memiliki banyak sumber daya alam ilmenit yang dapat dimanfaatkan lebih lanjut menjadi material mesopori Fe2O3 TiO2. Material mesopori dengan dinding (wall) yang tersusun atas nano-kristalin TiO2 adalah kandidat yang sangat menjanjikan dalam memberikan sumbangan yang sangat signifikan untuk mengatasi permasalahan lingkungan dan krisis energi yang melanda dunia. Namun demikian, hingga sekarang ini masih sulit untuk memperoleh kombinasi sinergis dua hal utama yaitu susunan pori yang teratur (highly-oriented) dan tingkat kristalinitas yang tinggi. Penelitian ini bertujuan untuk mensintesis mesopori Fe2O3 TiO2 dari mineral ilmenit (FeTiO3) untuk aplikasi pemurnian air limbah dan pembuatan prototipe DSSC. Metode yang digunakan dalam penelitian adalah kombinasi teknik hidrotermal dan sol−gel. Tahapan proses adalah mineral ilmenit yang telah dihaluskan dilakukan proses dekomposisi dengan larutan basa dalam autoklaf kemudian dilanjutkan dengan proses pelindian menggunakan asam sulfat. Larutan TiOSO4 yang dihasilkan digunakan sebagai prekursor dalam mempersiapkan nanopartikel TiO2 atau material mesopori Fe2O3 TiO2. Pengontrolan dalam proses sol−gel dilakukan dengan penambahan Fe, dextrin dan triblock copolimer. Hasil penelitian dikarakterisasi menggunakan XRF, AAS, TEM/SEM, BET, XRD, DRS, UV Vis. Hasil penelitian memberikan gambaran tentang potensi yang besar terhadap ilmenit Bangka untuk dimanfaatkan sebagai bahan baku dalam pembuatan material mesopori Fe2O3 TiO2. Ilmenit terdekomposisi dengan pelarut basa (KOH dan NaOH) membentuk fase intermediet yaitu kalium titanat dan natrium titanat dengan morfologi yang berbentuk benang-benang halus. Penambahan bubuk Fe dan dextrin mampu mengontrol pembentukan nanopartikel dan meningkatkan kemurnian TiO2. Penelitian ini juga berhasil mempersiapkan mesopori Fe2O3 TiO2 yang digolongkan sebagai bidang kristal anatase maupun rutil dengan ukuran kristal rata-rata berkisar 5 -7 nm, energi band gab berkisar 3,00 ? 3,16 eV dan luas permukaan, SBET berkisar.100 ? 151 m2/g.;

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ABSTRACT
Indonesia has many natural resources including ilmenite which could be exploited further into mesoporous TiO2 Fe2O3 materials. Mesoporous materials with walls composed of nano-crystalline TiO2 are very promising candidate in a very significant contribution for solving environmental problems and energy crisis that hit in the world. However, until now it is still difficult to obtain a synergistic combination of two major things that the regular arrangement of pores (highlyoriented) and a high degree of crystallinity. This study aims to synthesize mesoporous TiO2 Fe2O3 of the ilmenite (FeTiO3) mineral for waste water purification applications and prototyping DSSC. The method used in the study is a combination of hydrothermal and sol-gel techniques. Stage of the process was ilmenite mineral which has been smoothed carried out the decomposition process using alkaline solution in the autoclave and then followed by a leaching process using sulfuric acid. The TiOSO4 solution obtained was used as a precursor in the preparation of TiO2 nanoparticles or mesoporous TiO2 Fe2O3 material. Controlling the sol-gel process was done with the addition of Fe, dextrin and triblock copolimer. The results of the study were characterized using XRF, AAS, TEM/SEM, BET, XRD, DRS, UV-Vis apparatus. The results of the study provided an overview of the enormous potential of the Bangka-Indonesia ilmenite to be used as raw material in the manufacture of mesoporous TiO2 Fe2O3 materials. Ilmenite decomposed by alkaline solvent (KOH and NaOH) formed the intermediate phase of potassium titanate and sodium titanate with morphology shaped by fine threads. The addition of Fe powder and dextrin were able to control the formation nanoparticles and increase the purity of TiO2. This study also succeeded in preparing mesoporous TiO2 Fe2O3 classified as anatase and rutile crystal planes with an average crystal size ranges from 5 to 7 nm, the band gap energy ranges from 3.00 to 3.16 eV and the surface area (SBET) ranges from 100 to 151 m2/g.;Indonesia has many natural resources including ilmenite which could be exploited further into mesoporous TiO2 Fe2O3 materials. Mesoporous materials with walls composed of nano-crystalline TiO2 are very promising candidate in a very significant contribution for solving environmental problems and energy crisis that hit in the world. However, until now it is still difficult to obtain a synergistic combination of two major things that the regular arrangement of pores (highlyoriented) and a high degree of crystallinity. This study aims to synthesize mesoporous TiO2 Fe2O3 of the ilmenite (FeTiO3) mineral for waste water purification applications and prototyping DSSC. The method used in the study is a combination of hydrothermal and sol-gel techniques. Stage of the process was ilmenite mineral which has been smoothed carried out the decomposition process using alkaline solution in the autoclave and then followed by a leaching process using sulfuric acid. The TiOSO4 solution obtained was used as a precursor in the preparation of TiO2 nanoparticles or mesoporous TiO2 Fe2O3 material. Controlling the sol-gel process was done with the addition of Fe, dextrin and triblock copolimer. The results of the study were characterized using XRF, AAS, TEM/SEM, BET, XRD, DRS, UV-Vis apparatus. The results of the study provided an overview of the enormous potential of the Bangka-Indonesia ilmenite to be used as raw material in the manufacture of mesoporous TiO2 Fe2O3 materials. Ilmenite decomposed by alkaline solvent (KOH and NaOH) formed the intermediate phase of potassium titanate and sodium titanate with morphology shaped by fine threads. The addition of Fe powder and dextrin were able to control the formation nanoparticles and increase the purity of TiO2. This study also succeeded in preparing mesoporous TiO2 Fe2O3 classified as anatase and rutile crystal planes with an average crystal size ranges from 5 to 7 nm, the band gap energy ranges from 3.00 to 3.16 eV and the surface area (SBET) ranges from 100 to 151 m2/g.;Indonesia has many natural resources including ilmenite which could be exploited further into mesoporous TiO2 Fe2O3 materials. Mesoporous materials with walls composed of nano-crystalline TiO2 are very promising candidate in a very significant contribution for solving environmental problems and energy crisis that hit in the world. However, until now it is still difficult to obtain a synergistic combination of two major things that the regular arrangement of pores (highlyoriented) and a high degree of crystallinity. This study aims to synthesize mesoporous TiO2 Fe2O3 of the ilmenite (FeTiO3) mineral for waste water purification applications and prototyping DSSC. The method used in the study is a combination of hydrothermal and sol-gel techniques. Stage of the process was ilmenite mineral which has been smoothed carried out the decomposition process using alkaline solution in the autoclave and then followed by a leaching process using sulfuric acid. The TiOSO4 solution obtained was used as a precursor in the preparation of TiO2 nanoparticles or mesoporous TiO2 Fe2O3 material. Controlling the sol-gel process was done with the addition of Fe, dextrin and triblock copolimer. The results of the study were characterized using XRF, AAS, TEM/SEM, BET, XRD, DRS, UV-Vis apparatus. The results of the study provided an overview of the enormous potential of the Bangka-Indonesia ilmenite to be used as raw material in the manufacture of mesoporous TiO2 Fe2O3 materials. Ilmenite decomposed by alkaline solvent (KOH and NaOH) formed the intermediate phase of potassium titanate and sodium titanate with morphology shaped by fine threads. The addition of Fe powder and dextrin were able to control the formation nanoparticles and increase the purity of TiO2. This study also succeeded in preparing mesoporous TiO2 Fe2O3 classified as anatase and rutile crystal planes with an average crystal size ranges from 5 to 7 nm, the band gap energy ranges from 3.00 to 3.16 eV and the surface area (SBET) ranges from 100 to 151 m2/g., Indonesia has many natural resources including ilmenite which could be exploited further into mesoporous TiO2 Fe2O3 materials. Mesoporous materials with walls composed of nano-crystalline TiO2 are very promising candidate in a very significant contribution for solving environmental problems and energy crisis that hit in the world. However, until now it is still difficult to obtain a synergistic combination of two major things that the regular arrangement of pores (highlyoriented) and a high degree of crystallinity. This study aims to synthesize mesoporous TiO2 Fe2O3 of the ilmenite (FeTiO3) mineral for waste water purification applications and prototyping DSSC. The method used in the study is a combination of hydrothermal and sol-gel techniques. Stage of the process was ilmenite mineral which has been smoothed carried out the decomposition process using alkaline solution in the autoclave and then followed by a leaching process using sulfuric acid. The TiOSO4 solution obtained was used as a precursor in the preparation of TiO2 nanoparticles or mesoporous TiO2 Fe2O3 material. Controlling the sol-gel process was done with the addition of Fe, dextrin and triblock copolimer. The results of the study were characterized using XRF, AAS, TEM/SEM, BET, XRD, DRS, UV-Vis apparatus. The results of the study provided an overview of the enormous potential of the Bangka-Indonesia ilmenite to be used as raw material in the manufacture of mesoporous TiO2 Fe2O3 materials. Ilmenite decomposed by alkaline solvent (KOH and NaOH) formed the intermediate phase of potassium titanate and sodium titanate with morphology shaped by fine threads. The addition of Fe powder and dextrin were able to control the formation nanoparticles and increase the purity of TiO2. This study also succeeded in preparing mesoporous TiO2 Fe2O3 classified as anatase and rutile crystal planes with an average crystal size ranges from 5 to 7 nm, the band gap energy ranges from 3.00 to 3.16 eV and the surface area (SBET) ranges from 100 to 151 m2/g.]

Abstrak :
Fitosom merupakan salah satu nanovesikel lipid yang dapat meningkatkan absorbi zat aktif. Ekstrak teh hijau diformulasikan menjadi fitosom. Tujuan untuk melihat kemampuan fitosom menghambat kenaikan berat badan. Tiga formula dengan hidrasi lapis tipis, selanjutkan dikarakterisasi pembentukan kompleks fitosom, morfologi, ukuran partikel, zeta potensial, indeks polidispersitas , dan uji efisiensi penjerapan. Fitosom dan ekstrak teh hijau diuji absorbsi secara in vitro. Sebanyak 25 ekor tikus dibagi menjadi lima kelompok uji, kelompok normal, plasebo, orlistat, ekstrak teh hijau dan fitosom. Selama 8 minggu diinduksi peroral menggunakan fruktosa 10% + kolesterol 2% dan perlakuan uji. Karakteristik terbaik FIII terbentuk kompleks, morfologi bentuk sferis, Dv90 782,67 ± 39,7 nm, polidispersitas indeks 56 ± 0,11, zeta potensial -70,83 ± 1,67 mV, dan efisiensi penjerapan 97,77 ± 2,66%. Hasil pengujian terhadap hewan uji pada minggu ke-8 persentase kenaikan berat badan pada perlakuan normal 46,47 ± 17,48 %, plasebo 101,17 ± 10,37%, orlistat 42,51 ±25,13 %, ekstrak teh hijau 92,73 ± 36,43 %, dan fitosom 45,09 ± 15,56 %. Fluks ekstrak teh hijau sebesar 2.316,2 ± 1309,8 µg/cm2/jam dan fitosom 3.125,3 ± 2071,8 µg/cm2/jam. Kesimpulan dari penelitian ini adalah fitosom dapat menghambat kenaikan berat badan dan lebih baik jika dibandingkan dengan ekstrak teh hijau (p < 0,05).

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Phytosomes are one of the lipid nanovesicles that can increase the absorption of active substances. Green tea extract is formulated into phytosomes. The goal is to see the ability of phytosomes to inhibit weight gain. Three formulas with thin layer hydration were further characterized by phytosome complex formation, morphology, particle size, zeta potential, polydispersity index, and entrapment efficiency. Phytosomes and green tea extracts were tested for absorption in vitro. A total of 25 rats were divided into five test groups, the normal group, placebo, orlistat, green tea extract and phytosomes. For 8 weeks orally induced using fructose 10% + 2% cholesterol and treatment. The best characteristics of FIII are complex, spherical morphology, Dv90 782.67 ± 39.7 nm, polydispersity index 56 ± 0.11, zeta potential -70.83 ± 1.67 mV, and entrapment effiiency 97.77 ± 2.66 %. Test results on test animals at 8 weeks percentage of weight gain in normal treatment 46.47 ± 17.48%, placebo 101.17 ± 10.37%, orlistat 42.51 ± 25.13%, green tea extract 92, 73 ± 36.43%, and fitosomes 45.09 ± 15.56%. Green tea extract flux was 2,316.2 ± 1309.8 µg/cm2/hour and phytosomes 3,125.3 ± 2071.8 μg/cm2/hour. The conclusion of this study is that phytosomes can inhibit weight gain and are better when compared to green tea extracts (p <0.05).

Abstrak :
ABSTRAK
Malaria masih menjadi salah satu masalah di dunia. Salah satu tantangan dalam eliminasi malaria adalah timbulnya resistensi obat antimalaria. Terjadinya resistensi telah mendorong usaha untuk penemuan kandidat obat antimalaria. Beberapa studi yang dilakukan memperlihatkan adanya aktivitas antimalaria dari produk fermentasi Streptomyces sp. Streptomyces sp. menghasilkan beberapa metabolit sekunder yang diantaranya memilki aktivitas antimalaria yaitu prodigiosin. Penelitian ini bertujuan untuk mengetahui efektivitas produk fermentasi Streptomyces sp. sebagai antimalaria, mekanisme kerja hambatannya dan sifat toksisitasnya terhadap sel HepG2. Penelitian ini merupakan penelitian eksperimental dengan teknik in vitro, menggunakan galur parasit Plasmodium falciparum 3D7 drug sensitive . Penelitian dilakukan untuk mengetahui potensi produk fermentasi Streptomyces sp. sebagai antimalaria dengan melakukan uji IC50, dan mekanisme kerja dengan Transmission Electron Microscopy TEM . Dilakukan pula uji toksisitas produk fermentasi Streptomyces sp. pada sel HepG2. Produk fermentasi Streptomyces sp. memiliki aktivitas sebagai antimalaria dengan nilai IC50 sebesar 0,001 ?g/mL, sedangkan kontrol kuinidin yang digunakan memiliki nilai IC50 sebesar 0,054 ?g/mL dan prodigiosin 0,022 ?g/mL. Hasil pengamatan dengan TEM menunjukkan tidak terbentuknya hemozoin. Produk fermentasi Streptomyces sp. bersifat tidak toksik terhadap sel hati HepG2 dengan nilai CC50 1380 ?g/mL. Produk fermentasi Streptomyces sp. memiliki potensi sebagai antimalaria dan tidak memiliki efek toksik terhadap sel HepG2

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ABSTRACT
Malaria remains one of the problem in the world. One of the challenge in malaria elimination is the emergence of antimalarial drug resistance. The occurance of drug resistance has been encouraging efforts to find antimalarial drugs candidate. Some studies showed that there was antimalarial activity from Streptomyces sp. fermentation. Streptomyces sp. produced some secondary metabolite, which include prodigiosin who had antimalarial activity. This research aim to know the activity of Streptomyces sp. fermentation product as antimalarial, worked mechanism and toxicity on HepG2 cell. This research was experimental research with in vitro technique using Plasmodium falciparum 3D7 drug sensitive parasite. The research was done to know potency of Streptomyces sp. fermentation product as antimalarial by IC50 test, and worked mechanism by Transmission Electron Microscopy TEM . Toxicity tests was also done on HepG2 cell. Streptomyces sp. fermentation product has activity as antimalarial with IC50 value 0,001 g mL, quinidine control has IC50 value 0,054 g mL and prodigiosin 0,022 g mL. Observation with TEM showed no formation of hemozoin. Streptomyces sp. fermentation product was not toxic for HepG2 sel with CC50 value 1380 g mL. Streptomyces sp. fermentation product has a potency as antimalarial and not toxic for HepG2 cell.

Abstrak :
In this work the formation of Fe-Cr microalloy by ultrasonic irradiation at a frequency of 20 kHz is presented. Two sample series were produced with different ultrasonic irradiation procedures. For the first sample, Fe and Cr powder were each separately brought into the ultrasonic device before they were mixed in 7:1 weight ratio and then together retreated using the ultrasonic method. Secondly, Fe and Cr powder with same weight ratio were mixed and directly ultrasonically irradiated. During the ultrasonic irradiation process both samples were put in a toluene solution of 99%. The formation of the Fe-Cr microstructure in conjunction with ultrasonication time were investigated by using Scanning Electron Microscopy (SEM ), X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). After 40 hours of ultrasonic irradiation the particle sizes of the Fe powder of the first samples became significantly smaller; some particles were also fused together. However, with the exception of smaller-sized particles no fused Cr powders can be found even after 63 hours of ultrasonic irradiation. After both experiments Fe and Cr were mixed and again ultrasonically irradiated for 20 hours. Some particles indicated as Fe-Cr alloys containing 24.34 wt.% Fe and 67.43 wt.% Cr were observed. In the sample produced from the second procedure in which both Fe and Cr powders were irradiated together by an ultrasonic method for 50 hours, some powder particles formed a Fe-Cr microalloy with the composition of 96.27 wt.% Fe and 3.73 wt.% Cr. The XRD analysis revealed that the Fe-Cr alloy from the first samples has a BCC structure with a mass fraction of Fe:Cr:Fe-Cr which is equal to 0.836:0.0294:0.135, while the mass fraction of the Fe-Cr alloy from the second sample series is equal to 0.736:0.0808:0.183, respectively. Analysis of the TEM selected area diffraction patterns (SAED) confirmed that the Fe-Cr microalloy occured originaly from the precursor Fe and Cr particles of size smaller than 2 µm. The Fe-Cr microalloy has been successfully synthesized by using an ultrasonic process.

Abstrak :
The 56Fe16.6Cr25Ni0.9Si0.5Mn austenitic superalloy has been produced in an induction furnace; it was made from granular ferro-scrap, ferrochrome, ferrosilicon, and ferromanganese materials. Originally, this alloy had been proposed for use in high mechanical loads and high temperature conditions (such as in nuclear and fossil fuel power plant facilities). Tensile strength tests showed that the alloy has an average yield strength of about 430.56 MPa, which is higher than Incoloy A-286 (a commercially available alloy). A combination of microscopy techniques by means of an optical microscope, X-ray diffraction [XRD], scanning electron microscopy [SEM], and transmission electron microscopy [TEM] techniques were applied in order to get detailed information about the fine structure of the alloy. XRD confirmed that the alloy matrix exhibits an FCC crystal structure with a lattice parameter of about 3.60 Å and grain sizes ranging from 50 to 100 µm. The results of the TEM analysis revealed the new type of precipitations that formed at the grain boundaries. These needle-like precipitations, probably Fe/Cr-rich precipitations of the (Fe,Cr)xCy type, acted as the source of intergranular corrosion (IGC). Small coherent plate-like and much smaller granular precipitations were found distributed homogenously along grain boundaries and inside the grains. Combining the tensile strength test and microstructure analysis suggested that these precipitations play significant roles in the hardness of the investigated sample.

Abstrak :
Penelitian ini mengunakan gas oksigen sebagai pengoksidasi dari gas hidrokarbon menghasilkan CO2, CO dan H2O, dimana gas-gas ini memiliki peranan terhadap pertumbuhan CNT dengan cara melakukan uji laju alir oksigen dalam proses sintesis CNT. Dan, penelitian ini juga melakukan variasi waktu pretreatment Oxidative Heat Treatment (OHT) katalis dalam sintesis CNT. Plastik Polypropylene (PP) diprolisis pada suhu 500 oC dan disintesis pada suhu 800 oC selama 1 jam. Kemudian, laju alir O2 yang digunakan sebesar 33 ml/menit, 50 ml/menit dan 66 ml/menit (Sampel A, B, C) dengan waktu pretreatment OHT stainless steel (SS) 316 selama 1 menit. Kemudian melakukan uji waktu pretreatment (OHT) stainless steel (SS) 316 selama 1, 5, 10, 20 menit (Sampel A, D, E, F,) dengan laju alir gas oksigen yang digunakan 33 ml/menit. Dan karakterisasi CNT mengunakan alat XRD, TEM dan TGA. Diameter CNT yang dihasilkan Sampel A, B, C, D, E dan F adalah 9,46 nm, 16,84 nm, 33,93 nm, 12,34 nm, 11,39 nm, dan 15,74 nm. Produksi optimum sintesis CNT berada pada laju alir gas O2 33 ml/menit selama 1 menit pretreatment OHT SS dengan yield 9,9 %. ...... This research using oxygen as oxidation of hydrocarbon to produce CO2, CO, and H2O which they are important for growth of CNT with variance of it flowrate. And, this research is to do variance of pretreatment time of catalyztic. Oxygen to synthesis CNT. Plastik polypropylene (PP) is pyrolysed on temperature 500 oC and synthesized on temperature 800 oC during 1 hour. Then, flowrate of oxygen is used 33 ml/minute, 50 ml/minute, 66 ml/minute with long pretreatment stainless steel (SS) 316 during 1 minute. Then, next is to do variance of long pretreatment catallytic SS 316 during 1, 5, 10 and 20 minute. Then, characterization of CNT is using XRD, TEM and TGA. The result of outer diameter CNT from Sampel A, B, C, D, E dan F are 9.46 nm, 16.84 nm, 33.93 nm, 12.34 nm, 11.39 nm, and 15.74 nm. Optimum production is on flowrate of oxygen 33 ml/min during 1 minute of pretreatment OHT catalytiz with 9.9 % yield.