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Abstrak :
Remdesivir merupakan obat yang memberikan efek besar dalam menyembuhkan pasien yang terjangkit COVID-19, ketersediaan remdesivir di pasaran sangat terbatas dalam segi jumlah, bentuk sediaan hingga dosis. Terbatasnya dosis membuat adanya kesulitan dalam penyesuaian dosis, terutama pasien geriatri dan pediatri, sehingga banyak dosis obat yang akan terbuang karena obat remdesivir yamg telah direkonstitusi hanya stabil selama 4 jam pada suhu 25ºC. Tujuan penelitian ini untuk melihat kestabilan obat remdesivir yang beredar di Indonesia secara fisik dan kimia pada penyimpanan dengan suhu 2-8 ºC selama 2 hari dan suhu -10 s/d 20ºC selama 44 hari. Parameter stabilitas secara fisik diantaranya dilakukan uji pH, bobot jenis, viskositas, ukuran partikel dan potensial zeta, parameter secara kimia dilakukan uji penetapan kadar menggunakan kromatografi cair kinerja tinggi. Hasil yang diperoleh selama penyimpanan 48 jam pada suhu 2-8ºC memberikan hasil yang stabil secara fisika ditinjau dari pH dan ukuran partikel, namun belum dapat dibuktikan stabil secara kimia ditinjau dari kadarnya. Untuk penyimpanan suhu -10 s/d -20 ºC selama 44 hari tidak memperlihatkan kestabilan yang baik secara fisik maupun kimia karena parameter fisika maupun kimia tidak dapat bertahan selama masa penyimpanan. ......Remdesivir is a drug that has a great effect in curing patients infected with COVID-19, the availability of remdesivir on the market is very limited in terms of quantity, dosage form and dosage. Since the drug's limited dose makes it difficult to change the dosage, particularly for elderly and pediatric patients, many doses of the medication will be squandered. Remdesivir, when reconstituted, is only stable for four hours at 25°C. The goal of this study was to assess the physical and chemical stability of remdesivir, which was circulating in Indonesia at temperatures of 2–8 C for 2 days and –10–20 C for 44 days. Particle size, pH, specific gravity, viscosity, and zeta potential were assessed for physical stability characteristics, while high performance liquid chromatography was used to measure chemical stability parameters. Physically stable results were obtained for pH and particle size after 48 hours of storage at a temperature between 2 and 8 oC, but chemical stability for levels was not established. Because the physical and chemical characteristics could not endure the 44-day storage period, storage at -10 to -20 C did not demonstrate good physical or chemical stability.

Abstrak :
Negara Indonesia banyak memiliki gunung berapi yang masih aktif dan yang sudah tidak aktif lagi di daerah-daerah sekitar pegunungan tersebut banyak terdapat deposit mineral dalam jumlah yang cukup besar yang dapat dimanfaatkan, seperti zeolit. Pada penelitian ini zeolit akan dimanfaatkan sebagai bahan bakar pembuat membran keramik. Membran yang Ielah banyak digunakan pada masa sekarang ini terbuat dari polimer yang kurang efektif bila digunakan pada suhu yang cukup tinggi sehingga diperlukan suatu alternative seperti membrane keramik ini. Zeolit yang akan digunakan sebagai bahan baku pembuat membran keramik ini harus memiliki beberapa sifat.fisik dan sifat mekanis yang tertentu sehingga menunjang dalam aplikasinya digunakankan sebagai membran. Pembuatan membran ini menggunakan teknologi serbuk yang cukup sederhana dengan menggunakan variasi distribusi ukuran parlikel yang cukup seragam (narrow particle size distribution) untuk ukuran mesh 80, 100 dan 120 yang didapat melalui proses pengayakan (sieving). Teknologi serbuk yang digunakan antara lain adalah pengayakan untuk mendapatkan ukuran partikel yang seragam, kompaksi dengan beban penekanan 10,2 ton dan proses sintering pada suhu 11 00 ℃ selama 2 jam untuk mendapatkan kekuatan dan sifat fisik yang tinggi sampel prototipe membran keramik. Untuk mengetahui sifat fisiknya dilakukan pengujian porositas dan hasil yang diperoleh dari penelitian ini adalah kecenderungan berkurangnya porositas mulai dari 43% menjadi 42% dan 30% dengan bertambah halusnya ukuran butir (bertambahnya ukuran mesa). Sedangkan sifat mekanis yang ingin diketahui adalah dengan melakukan pengujian kekerasan dimana hasilnya adalah terjadi peningkatan kekerasan yaitu 23 VHN mejadi 24 VHN dan 27 VHN seiring dengan bertambah halusnya ukuran partikel dan peningkatan densitas mulai dari 1,302 gr/cm3 sampai 1,596 gr/cm3 dari sampel uji pembuat membran keramik dalam suatu distribusi ukuran partikel yang seragam. Dari hasil di atas terlihat terbukanya kesempatan yang besar untuk zeolite sebagai bahan pengganti pembuat membrane yang selama ini sudah ada, namun masih diperlukan penelitian yang lebih mendalam mengenai hal ini.

Abstrak :
Kurkumin, senyawa polifenol hidrofobik dari rimpang kunyit (Curcuma longa) memiliki aktivitas farmakologi yang luas. Bioavailabilitas kurkumin yang rendah menyebabkan pemanfaatannya masih belum maksimal. Dendrimer Poliamidoamin Generasi 4 (PAMAM G4) yang merupakan polimer unik bercabang, berukuran nanometer, monodisper, dan mampu menjerap molekul asing ke dalamnya dapat dimanfaatkan sebagai pembawa nanopartikel kurkumin untuk meningkatkan kestabilannya. Pada penelitian ini akan dibuat nanopartikel kurkumin menggunakan Polimer Dendrimer PAMAM G4 sebagai pembawanya dengan rasio Kurkumin : Dendrimer (50:25)μM dan diuji kestabilanya dalam lingkungan in vitro. Nanopartikel-Kurkumin-Dendrimer PAMAM G4 (NP-KD) dimurnikan menggunakan sentrifugasi ultrafiltrasi dan dikarakterisasi menggunakan TEM, PSA, Zetasizer, dan FTIR. Kestabilan dan efisiensi penjerapan ditetapkan secara spektrofotometri UV-Vis. Stabilitas Nanopartikel Kurkumin-Dendrimer PAMAM G4 secara in vitro dilakukan pengamatan setiap hari selama 10 hari dengan menggunakan alat Spektrofotometer UV-Vis. Hasil penelitian menunjukan bahwa NP-KD memiliki bentuk sferis dengan diameter partikel 53,9±65,55 nm, indeks polidispersitas 0,468±0,04, potensial zeta -68,505±1,845 mV. Hasil uji stabilitas NP-KD secara in vitro selama 10 hari menunjukan bahwa NP-KD stabil di dalam dapar pH 3,0 ; kurang stabil dalam Aquabides; Dapar pH 7,4; Dapar pH 11,0; NaCl 0,35%; NaCl 0,5%; NaCl 0,9%; dan tidak stabil dalam Sistein 1%; dan Bovin Serum Albumin (BSA) 2%. Hasil pengukuran NP-KD dalam dapar pH 3,0 setelah uji stabilitas menunjukan diameter partikel yang tetap stabil pada 45,97±13,08 nm dan memiliki nilai indeks polidispersitas 0,364±0,03. Hasil penelitian tersebut menunjukan bahwa NP-KD stabil pada pH asam. ......Curcumin, a hydrophobic polyphenol compound derived from the rhizome of turmeric (Curcuma longa) has a wide pharmacological activities. Low bioavailability of curcumin caused the under-developed utilization. Polyamidoamine Generation 4 (PAMAM G4) dendrimer is unique branched polymer , nano-sized, monodisperse, and has ability to entrap guest molecules so it can be used as ideal carrier systems to improve stability of curcumin nanoparticles. In this study, will be prepared and studies in vitro of curcumin nanoparticles with dendrimer PAMAM G4 as a carrier with ratio curcumin : dendrimer (50:25)μM. Nanocurcumin were purified by ultrafiltration centrifugation method and characterizated by TEM, PSA, Zetasizer and FTIR. The result showed that the spherical nanocurcumin have a particle size of 53,9±65,55 nm, polydisperisty index 0,468±0,04, and zeta potential -68,505±1,845 mV. Stability test result of nanocurcumin in 10 days showed that nanocurcumin were stable in buffer solution pH 3,0, almost stable in Aquabidest; buffer solution 7,4 and 11,0 ; NaCl solution 0,35%; 0,5% and 0,9% and unstable in cystein solution 1% and Bovin Serum Albumin (BSA) 2%. Particle measurement results after in vitro studies of nanocurcumin in buffer solution pH 3,0 after stability showed the particle was stable in 45,97±13,08 nm and polydispersity index was 0,364±0,03. Thus, these result nanocurcumin stable in acid solution.

Abstrak :
Composited tile was made using marble particles, phenol resin and hcxamethy leneleiramine (HEXA) as the catalyst. The matrix and hardener of these materials were mixed on volume variation from 62.50 ml to 12?,()<) ml. and on variation of 25. 40 and 60 mesh. Samples were dried in a room temperature for 3 hours. The compressive strength and crystal structure were analysed. The results showed that compressive strength values were in range of 6.15 x I07 N/m" - 9.61 x Id7 N/n. and there were two crystal structures consisted of marble crystal and phenol crystal. The analysis was carried out by using the Rietveld semi quantitative analysis. The final crystal structure of marble is rhombothedral, where the lanice constants arc a h =- 4.969 A: c = 17.026 A. This results indicate that the composites and marble can he used to make tile, because they were lighter, stronger and the amount of crystals increases compared with the pure marble.

Abstrak :
Trimethololethane (TME) tryhydrate particle suspended in water is a proper substance for latent heat tranportation in cooling system,since it has high heat tranfer and thermal capacity.....

Abstrak :
Analysis of alfa emitted radionuclide deposition at respiratory tract via inhalation process under difference air-ventilation system at radiometallurgy intallation...

Abstrak :
Barium strontium titanate (BST) or Ba1-xSrxTiO3 with x=0-1 possesses superior dielectric properties, which are widely used in many applications like in communication technology, electronic instrumentations, and various electrical devices. In this paper, the characterization of the particle and crystallite size of Ba1-xSrxTiO3 (x: 0; 0.3; 0.7) is described. A two-step refinement commenced: first by mechanical milling, and then a further refinement under ultrasonic irradiation in a high power sonicator was applied to Ba1-xSrxTiO3 (x: 0; 0.3; 0.7) particles. The crystalline powders were obtained through mechanically alloyed standard research grade BaCO3, TiO2, and SrCO3 precursors in a planetary ball mill.The powders were first found heavily deformed after 60 hours of milling and then went through a sintering process at 1200°C for 4 hours to form multicrystallite particles. The presence of a single phase in the three samples was solidly confirmed in their respective X-ray diffraction (XRD) patterns. The changes of multicrystallite particles into monocrystallite particles were obtained only after crystalline powders were irradiated ultrasonically in a high power sonicator. The processing variable during ultrasonic irradiation was limited to the duration time of irradiation and particle concentration in the exposed media. It is shown that the average sizes of BST particles at x=0; 0.3; 0.7 before ultrasonic irradiation were 353, 348, and 385 nm, respectively. These respective sizes decreased drastically to 52, 35, and 49 nm, respectively, after 12 hours of ultrasonic irradiation. These particle sizes are almost identical with that of their crystallite size. Hence, the synthesis of monocrystallite particles has been achieved. As the particle concentration of media takes effect, it is shown that an exposed media with a higher particle concentration tends to form multicrystallite particles.

Abstrak :
Barium strontium titanate (BST) or Ba1-xSrxTiO3 with x=0-1 possesses superior dielectric properties, which are widely used in many applications like in communication technology, electronic instrumentations, and various electrical devices. In this paper, the characterization of the particle and crystallite size of Ba1-xSrxTiO3 (x: 0; 0.3; 0.7) is described. A two-step refinement commenced: first by mechanical milling, and then a further refinement under ultrasonic irradiation in a high power sonicator was applied to Ba1-xSrxTiO3 (x: 0; 0.3; 0.7) particles. The crystalline powders were obtained through mechanically alloyed standard research grade BaCO3, TiO2, and SrCO3 precursors in a planetary ball mill.The powders were first found heavily deformed after 60 hours of milling and then went through a sintering process at 1200°C for 4 hours to form multicrystallite particles. The presence of a single phase in the three samples was solidly confirmed in their respective X-ray diffraction (XRD) patterns. The changes of multicrystallite particles into monocrystallite particles were obtained only after crystalline powders were irradiated ultrasonically in a high power sonicator. The processing variable during ultrasonic irradiation was limited to the duration time of irradiation and particle concentration in the exposed media. It is shown that the average sizes of BST particles at x=0; 0.3; 0.7 before ultrasonic irradiation were 353, 348, and 385 nm, respectively. These respective sizes decreased drastically to 52, 35, and 49 nm, respectively, after 12 hours of ultrasonic irradiation. These particle sizes are almost identical with that of their crystallite size. Hence, the synthesis of monocrystallite particles has been achieved. As the particle concentration of media takes effect, it is shown that an exposed media with a higher particle concentration tends to form multicrystallite particles.

Abstrak :
The performance of anaerobic digestion (AD) to process organic fraction of municipal solid waste (OFMSW) can be improved with various pre-treatments. Mechanical pre-treatments, mainly chopping, have shown to be the most economical and relatively effective method to increase contact between the substrate and microorganisms. The purpose of this research was to analyze the effect of OFMSW particle size on CH4 gas formation in a laboratory-scale Biochemical Methane Potential (BMP) assay. The research was conducted for 35 days at a temperature of 35°C with three sizes of OFMSW co-digested with cow manure. OFMSW with particle sizes of 10-13 mm, 4.76-10 mm, and 2-4.76 mm produce CH4 gas with an average of 114.7+14.7 ml, 101.7+0.5 ml, and 110.9+10.8 ml, respectively, while methane yield was 0.277 L CH4/g VS, 0.208 L CH4/g VS, and 0.229 L CH4/g VS, respectively. Particle size is more likely to have an influence on the hydrolysis and acidogenesis processes, as demonstrated by the significant difference of VFA value, but not on the biogas potential. Particle sizes of 13-15 mm produce 19.25 mg VFA/L, while the size range of 2-4.76 mm produces 118.1 mg VFA/L.

Abstrak :
Optimasi polimerisasi emulsi core-shell stirena-etil akrilat telah dilakukan pada penelitian ini, dengan penambahan konsentrasi inisiator NaPS tahap kedua, yakni 0,5%, 1,0% dan 1,5%. Teknik polimerisasi yang digunakan pada polimerisasi core stirena adalah batch dengan waktu 5 jam (4 jam reaksi dan 1 jam aging) dengan suhu polimerisasi 750C, dihasilkan core stirena dengan hasil konversi 86,65% dan ukuran partikel berkisar antara 68,78nm dengan nilai PDI sebesar 0,029, sedangkan teknik pada polimerisasi core-shell stirena-etil akrilat adalah semikontinu dengan dengan waktu 5 jam (4 jam feeding dan 1 jam aging) dengan suhu polimerisasi 750C. Variasi konsentrasi inisiator NaPS pada polimerisasi core-shell stirena-etil akrilat menghasilkan kondisi optimum pada konsentrasi inisiator NaPS 1,0%, yakni persen hasil konversi sebesar 75,07% dengan ukuran partikel berkisar 166.8nm dan nilai PDI sebesar 0,07. Data hasil karakterisasi FTIR, DSC, FE-SEM dan PSA memperkuat bukti telah terjadi polimerisasi.

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Optimation of styrene-ethyl acrylate core-shell have done at this study, with added initiator NaPS concentration in core-shell polimerization, 0.5%, 1.0% and 1.5%. The polymerization techniques used in styrene core polimerization was batch during 5 hours (4 hours reaction and 1 hour aging) at polymerization temperature 750C, resulted % conversion styrene core 86.65% and particle size gave particle size i.e. 68.78nm with PDI value i.e. 0.029, whereas the technique of styrene-ethyl acrylate core-shell polimerization was semicontinue during 5 hours (4 hours feeding and 1 hour aging) at polymerization temperature 750C. Variance NaPS initiator concentration in styrene-ethyl acrylate core-shell polimerization resulted optimum condition at NaPS initiator concentration 1.0%, % conversion i.e. 75.07% and particle size gave i.e. 166.8nm with PDI value i.e. 0.07. The result of characterization IR, DSC, SEM and PSA supported the evidence that occurred the polimerization.