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"Sintesis superabsorben dari selulosa sekam padi sebagai backbone dengan metode polimerisasi radikal bebas pada kopolimerisasi cangkok dengan monomer asam akrilat dan akrilamida dapat menghasilkan pupuk slow-release yang bersifat ramah lingkungan. Selulosa diisolasi dari sekam padi dengan tahapan ekstraksi lemak dengan toluen : etanol (2:1). Penghilangan hemiselulosa dan lignin dengan menggunakan kalium hidroksida 5% dan hidrogen peroksida 2% pH basa. Rendemen selulosa yang diperoleh adalah 39,5% untuk metoda I dan 59,50% untuk metoda II. Spektrum FTIR selulosa menunjukkan hilangnya serapan lignin pada bilangan gelombang 1728 cm-1 untuk selulosa I sedangkan pada selulosa II masih muncul gugus lignin. Indeks kristalinitas dari selulosa didapatkan dari hasil analisis XRD sebesar 68% untuk selulosa I sedangkan 60% untuk selulosa II. Kopolimerisasi berlangsung 2 jam pada suhu 70C dengan dialiri gas nitrogen. Inisiator dan agen pengikat silang yang digunakan adalah kalium peroksodisulfat dan N?N-metilena bis akrilamida. Hasil analisis SEM memperlihatkan bahwa permukaan kopolimer selulosa memiliki morfologi yang lebih kasar, homogen, dan merata disebabkan terjadinya pencangkokkan monomer ke selulosa sehingga jaringan superabsorben yang terbentuk semakin rapat. Superbasorben menunjukkan kapasitas pengembangan air dan urea dengan konsentrasi 200 ppm berturut-turut adalah 845,53 g/g dan 667,81 g/g untuk selulosa I dan 744,52 g/g dan 1459,13 g/g untuk selulosa II . Sedangkan kapasitas pelepasan air dan urea dari superbsorben yang paling baik adalah pada selulosa satu dengan kapasitas berturut-turut adalah 87,14 % dan 24,34%. Kinetika pengembangan dan pelepasan dari urea mengikuti orde pseudo-kedua.

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Superabsorbent that synthesized from rice husk cellulose as backbone and grafted with acrylic acid and acrylamide can be used as biodegradable slow release fertilizer. Cellulose was isolated from rice husk by extracted fat, wax, other extractive material with mixture of toluen and ethanol (2:1). Hemicellulose and lignin was removed by using potassium hydroxyde solution (5%) and hydrogen peroxyde solution (2%) in base condition. The average rendement of cellulose-1 obtained 39.50 % and 59.50 % for cellulose-2.

FTIR spectrum of cellulose showed that lignin from rice husk had been removed, it showed at wave number 1750 cm-1. The diffraction pattern of XRD obtained crystallinity index of rice husk 42.60 % which increased after isolated to 67.80% for cellulose-1 and cellulose-2 60.20 %. Copolymerization process was conducted at temperatur 70C for 2 hours and nitrogen gas was flowed into reactor. Potassium peroxodisulphate and N,N?-methylene bis-acrylamide was used as cross-linking agent and inisiator, respectively.

Mycrograph of SEM analysis showed that the surface of superabsorbent was rough and homogen because of monomer grafting that was done to cellulose. Swelling capacity of superabsobent in water and urea solution (200 ppm) were 845,53 g/g and 667,81 g/g for cellulose-1 and 744,52 g/g and 1459,13 g/g for cellulose-2, respectively. Release capacity of superbasobent for cellulose-1 was the best, and the release capacity were 87,14 % and 24,34% for water and urea solution respectively. Swelling and release kinetics of urea solution followed a pseudo-second order of rate law."

"Modifikasi pati singkong dikembangkan untuk meningkatkanpemanfaatan pati sebagai eksipien dalam sediaan farmasi. Sistem matrikshidrofilik dirancang untuk mengurangi frekuensi pemberian obat danmeningkatkan kepatuhan pasien. Tujuan penelitian ini adalah untukmenyelidiki kemampuan pregelatinasi pati singkong propioinat sebagaimatriks hidrofilik dalam mengendalikan pelepasan obat. Pregelatinasi patisingkong propionat dibuat dengan mereaksikan pregelatinasi pati singkongdengan asam propionat. Matriks-matriks tablet dibentuk dengan PPSPsebagai matriks tunggal dan juga dilakukan kombinasi dengan pembentukmatriks hidrofilik lainnya seperti HPC, HPMC, dan natrium alginat.Tablet didipersiapkan dengan metode cetak langsung untuk tiga formula pertama, danmetode granulasi basah untuk tiga formula terakhir. Uji disolusi dilakukanmengunakan alat tipe II dengan kecepatan pengadukan 50 rpm, selamadelapan jam dalam medium dapar fosfat pH 7,0. Hasilnya menunjukkanhanya PPSP yang dikombinasi dengan matriks lain yang dapat menahan lajupelepasan obat selama delapan jam. PPSP yang digunakan sebagai matrikstungggal, memiliki kemampuan yang buruk dalam mengendalikan pelepasanobat."

"Superabsorben nanokomposit berbasis natrium alginat tercangkok poli akrilat-co-akrilamida yang dikompositkan dengan montmorillonite MMT , dan dengan penambahan pupuk NPK ke dalam superabsorben nanokomposit dengan metode polimerisasi in situ telah berhasil disintesis pada panelitian ini. Pada awal penelitian dilakukan isolasi natrium alginat dari ganggang coklat dengan persen rendemen rata-rata yang diperoleh sebesar 44,26 . Selanjutnya, natrium alginat hasil isolasi dikopolimerisasi dengan menggunakan asam akrilat dan akrilamida sebagai monomer, kalium persulfat sebagai inisiator, N,N '; metilen-bis-akrilamida MBA sebagai agen pengikat silang dan ditambahkan MMT untuk memperkuat sifat fisik dari superabsorben nanokomposit. Superabsorben nanokomposit dikarakterisasi dengan instrumen FTIR untuk analisis gugus fungsi, XRD untuk analisis indeks kristanilitas, dan SEM untuk melihat morfologi permukaan. Kapasitas swelling air, urea, KH2PO4, dan NH4 H2PO4 superabsorben nanokomposit natrium alginat menunjukkan nilai kapasitas terbaik, yaitu berturut-turut sebesar 475.8 g/g, 491.1 g/g, 122.9 g/g, dan 134.9 g/g. Kapasitas release air, urea, KH2PO4, dan NH4 H2PO4 superabsorben nanokomposit natrium alginat menunjukkan nilai kapasitas terbaik, yaitu berturut-turut sebesar 70.9 , 69.8 , 52.6 , dan 48.6 . Kapasitas swelling optimum superabsorben nanokomposit pupuk lepas lambat dengan in situ urea, KH2PO4, NH4 H2PO4, yaitu berturut - turut sebesar 423.3 g/g, 89.8 g/g, dan 138.1 g/g. Kapasitas release optimum superabsorben nanokomposit pupuk lepas lambat dengan in situ urea, KH2PO4, NH4 H2PO4, yaitu berturut - turut sebesar 55.0 , 35.3 , 28.2 . Kinetika orde swelling optimum SA9 FD terhadap larutan air, urea, KH2PO4, dan NH4 H2PO4 mengikuti hukum laju orde pseudo-pertama. Kinetika orde release optimum SA9 FD terhadap larutan KH2PO4, dan NH4 H2PO4 mengikuti hukum laju orde pseudo-pertama, sedangkan kinetika orde release optimum SA9 FD terhadap larutan air dan urea mengikuti hukum laju orde pseudo-kedua. Kinetika orde swelling optimum superabsorben nanokomposit pupuk lepas lambat in situ KH2PO4 SA17 FD terhadap air mengikuti hukum laju orde pseudo-pertama, sedangkan kinetika orde swelling optimum superabsorben nanokomposit pupuk lepas lambat in situ urea SA14 FD , dan in situ NH4 H2PO4 SA20 FD mengikuti hukum laju orde pseudo-kedua. Kinetika orde release optimum SA14 FD dan SA20 FD terhadap larutan NaCl 0.9 mengikuti hukum laju orde pseudo-pertama, sedangkan kinetika orde release optimum SA17 FD mengikuti hukum laju orde pseudo-kedua. Hukum laju reaksi orde pseudo-pertama mengikuti persamaan v=k[absorbat]^1, sedangkan hukum laju reaksi orde pseudo-kedua mengikuti persamaan v=k[absorbat]^2.

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Superabsorbent nanocomposite based sodium alginate grafted poly acrylate co acrylamide composited with montmorillonite MMT , and with the addition of NPK fertilizers into superabsorbent nanocomposite by in situ polymerization methods have been successfully synthesized in this study. At the beginning of the study, the isolation of sodium alginate from brown algae with percentage of average yield was 44,26 . Furthermore, the isolated sodium alginate was copolymerized using acrylic acid and acrylamide as monomer, potassium persulfate as initiator, N, N 39 methylene bis acrylamide MBA as a crosslinking agent and MMT was added to enhance the physical properties of the superabsorbent nanocomposite. Superabsorbent nanocomposite were characterized by FTIR instruments for functional group analysis, XRD for christanility index analysis, and SEM for viewing surface morphology. The swelling capacity of water, urea, KH2PO4, and NH4 H2PO4 superabsorbent nanocomposite sodium alginate show the best capacity value, ie 475,8 g g, 491,1 g g, 122,9 g g, and 134,9 g g, respectively. The release capacity of water, urea, KH2PO4, and NH4 H2PO4 superabsorbent nanocomposite sodium alginate show the best capacity, ie 70,9 , 69,8 , 52,6 and 48,6 , respectively. The optimum swelling capacity of slow release fertilizer superabsorbent nanocomposites with in situ urea, KH2PO4, NH4 H2PO4, ie 423,3 g g, 89,8 g g, and 138,1 g g, respectively. The optimum release capacity of slow release fertilizer superabsorbent nanocomposites with in situ urea, KH2PO4, NH4 H2PO4, ie 55.0 g g, 35,3 g g, 28,2 g g, respectively. The optimum swelling order kinetics of SA9 FD against water, urea, KH2PO4, and NH4 H2PO4 solution follows the pseudo first order rate law. The optimum release order kinetics of SA9 FD against KH2PO4, and NH4 H2PO4 solution follows the pseudo first order rate law, whereas the optimum release order kinetics of SA9 FD against water and urea solution follows the pseudo second order rate law. The optimum swelling order kinetics superabsorbent nanocomposite fertilizer slow release in situ KH2PO4 SA17 FD against the water follows the pseudo first order rate law, while the optimum swelling order kinetics superabsorbent nanocomposite fertilizer slow release in situ urea SA14 FD , and in situ NH4 H2PO4 SA20 FD follows the pseudo second order rate law. The optimum release order kinetics SA14 FD and SA20 FD against 0.9 NaCl solution follows the pseudo first order rate law, while the optimum release order kinetics SA17 FD follows the pseudo second order rate law. The pseudo first order reaction rate law follows the equation v k absorbat 1, while the pseudo second order reaction rate law follows the equation v k absorbat 2."

"ABSTRAKBatas Pelepasan (BP) tiap zat radioaktif ke atmosfir untuk tiap instalasi nuklir BATAN di Serpong telah dianalisis. Tujuan dari analisis adalah untuk memperoleh batas aktivitas tertinggi tiap zat radioaktif yang dapat terlepaskan ke atmosfir pada operasi normal dimana dosis yang diterima oleh perorangan (a member of public) yang tinggal di sekitar instalasi nuklir tidak melampaui batasan dosis radiasi yang diperkenankan. Analisis dilakukan berdasarkan batasan dosis yang direkomendasikan oleh BATAN untuk perorangan dengan menggunakan metode factor pemekatan (concentration factor method). Dalam analisis besaran-besaran spesifik dengan keadaan lingkungan setempat diikutsertakan dalam perhitungan, sehingga nilai BP ini hanya berlaku untuk kawasan BATAN di Serpong. Besaran yang belum tersedia diadopsi dari berbagai pustaka, dalam hal ini nilai maksimal yang digunakan sehingga hasil perkiraan yang diperoleh cukup konservatif. Berdasarkan hasil analisis yang diperoleh selanjutnya diturunkan Batasan Normal Operasi (BNO), Batasan Administrasi (BA) dan Batasan Peringatan Dini (BPD). Batasan-batasan ini harus dioperasionalkan sebagai tolok-ukur dalam pemantauan pelepasan zat radioaktif ke atmosfir di tiap instalasi nuklir BATAN di Serpong, sehingga bila terjadi pelepasan yang menjurus abnormal dengan segera dapat diketahui. Hal ini memungkinkan untuk dilakukan penghentian operasi ataupun penyelidikan lebih lanjut untuk mengetahui kelainan operasi yang terjadi. Maka dengan mengoperasionalkan BNO, BA dan BPD ini keselamatan masyarakat dan lingkungan di sekitar instalasi nuklir BATAN dapat ditingkatkan.Pelepasan rat radioaktif ke atmosfir rata-rata per tahun dari tiap instalasi nuklir BATAN di Serpong berdasarkan desain-dasar telah dibandingkan dengan hasil analisis. Hasil yang diperoleh menuniukkan bahwa pelepasan berdasarkan desain-dasar adalah relafif lebih rendah. Hal ini memberikan infomnasi bahwa desain-dasar tiap instalasi nuklir BATAN tidak melampaui kapasitas radiologi lingkungan dari kawasan Serpong.

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ABSTRACT

Derived Release Limits (DRL) Of Each Radio nuclide Into The Atmosphere For Each Batan Nuclear Installation In Serpong, West JavaDerived release limits (DRL) of each radionuclide into the atmosphere for each BATAN nuclear installation were analyzed. The objective of the analysis is to find the limit values for each radionuclide, which can be released into the atmosphere during normal operation. The radiation doses received by a member of the public must not exceed the limit values. In this analysis, the DRL were calculated based on the dose limit values for a member of the public as recommended by BATAN. The method used in this analysis was concentration factor method. The site parameters were taken into account, but some parameters, which were not -available from these sites, were adopted from literatures. In order to estimate the maximum values of ORL, conservative estimation has been considered in the analysis. The results were then used to derive some other limit values, such as Normal Operation Level (NOL), Administration Level (AL) and Early Warning Level (EWL). These limit values can be used as a reference in monitoring the release of radionuclides in each installation so that abnormal release can be identified earlier, and hence an investigation or emergency stop are possible before nuclear accident happens. The application of the NOL, AL and EWL are useful to increase the safety of the public living in surrounding area of BATAN nuclear installations in Serpong.

The annual release rate of each radionuclide from each BATAN nuclear installation based or. The basic design was compared with the analysis results. The results showed that the release rate is relatively lower indicating that the radiological capacity of Serpong site is not exceeded."

"[ABSTRAKLatar belakang: Persalinan prematur sekarang ini menjadi tantangan dibidangobstetri. Ini terlihat dari tingginya angka prematur di dunia. Dua hal yang harusdiperhatikan dalam kehamilan prematur yaitu kontraksi dan pemberian kortikosteroiduntuk pematangan paru, maka dibutuhkan suatu penanganan dengan menggunakanobat tokolitik. Saat ini telah banyak digunakan terbutalin sulfat yang merupakangolongan agonis beta dan juga nifedipine yang merupakan golongan penyekat kanalkalsium. Namun penggunaan agonis beta menyebabkan efek yang kurang baik padaibu seperti takikardi, dispnoe dan ansietas sehingga penggunaannya sekarang mulaiterbatas. Tujuan: Tesis ini bertujuan mengetahui perbandingan efektifitas nifedipineoral dibandingkan dengan terbutalin sulfat sebagai tokolitik dalam kehamilanprematur. Metode: Penelitian ini merupakan uji klinis randomisasi tanpa penyamaranpada ibu hamil prematur di kurang dari 34 minggu di RSUPN Cipto mangunkusumo.Hasil: dari 60 subyek yang diikutsertakan dengan consecutive sampling, didapatkan56 subyek (93,3%) hilang kontraksi dengan rincian 27 subyek (90,0%) padakelompok nifedipin dan 29 subyek (96,7%) pada kelompok terbutalin (p=0,61).Kelompok yang diberikan nifedipin hilang kontraksi dengan median waktu 1,25(0,67-2,00) jam sementara kelompok yang diberikan terbutalin hilang kontraksi lebihcepat dengan median waktu 0,50 (0,50-1,50) jam (p<0,001). Tidak ada perbedaan efek samping yang ditemukan pada kedua kelompok. Simpulan: Nifedipin dan terbutalin memiliki efektifitas yang sama pada kehamilan prematur.

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ABSTRACTBackground: Preterm labour is considered as one of problems frequentlyencountered in obstetric and ginecologic department. To date, the incidence ofprematurity is still high worldwide. Two things should be noted: uterine contractionand corticosteroid for lung maturity of the baby. Thus, a tocolytic agent may be usefulin these circumstances. To date, terbutaline sulfate is widely used as it is known asbeta agonist. Beside, nifedine, a calcium channel blocker, is also widely accepted. Theuse of beta agonist might contribute several adverse events related to the mother,including tachycardia, dispnea, and anxiety. Some physicians have begun to restrictits use. Objective: This study aimed to compare the efficacy of slow releasenifedipine and terbutaline sulfate injection as a tocolytic agent for preterm labour.Methods: This is a randomized clinical trial unblinding. Subjects were pregnantwomen with prematurity (below 34 weeks of gestational age) at CiptoMangunkusumo hospital. Results: From a total of 60 subjects, 56 subjects (93.3%)had no contraction after given tocolytic (27 subjects (90.0%) in nifedipine group and29 subjects (96.7%) in terbutaline sulfate group; (p= 0.61). Subjects in nifedipinegroup lost their contraction after the drug was given with median time of 1.25 (0.672.00)hours while subjects in terbutaline sulfate group lost their contraction withmedian time of 0.50 (0.50-1.50) hours (p<0.001). There was no significantly differentproportion of adverse event found in both groups. Conclusions: Nifedipine and terbutaline sulfate have relatively same efficacy to vanish uterine contraction for prematurity management. ;Background: Preterm labour is considered as one of problems frequentlyencountered in obstetric and ginecologic department. To date, the incidence ofprematurity is still high worldwide. Two things should be noted: uterine contractionand corticosteroid for lung maturity of the baby. Thus, a tocolytic agent may be usefulin these circumstances. To date, terbutaline sulfate is widely used as it is known asbeta agonist. Beside, nifedine, a calcium channel blocker, is also widely accepted. Theuse of beta agonist might contribute several adverse events related to the mother,including tachycardia, dispnea, and anxiety. Some physicians have begun to restrictits use. Objective: This study aimed to compare the efficacy of slow releasenifedipine and terbutaline sulfate injection as a tocolytic agent for preterm labour.Methods: This is a randomized clinical trial unblinding. Subjects were pregnantwomen with prematurity (below 34 weeks of gestational age) at CiptoMangunkusumo hospital. Results: From a total of 60 subjects, 56 subjects (93.3%)had no contraction after given tocolytic (27 subjects (90.0%) in nifedipine group and29 subjects (96.7%) in terbutaline sulfate group; (p= 0.61). Subjects in nifedipinegroup lost their contraction after the drug was given with median time of 1.25 (0.672.00)hours while subjects in terbutaline sulfate group lost their contraction withmedian time of 0.50 (0.50-1.50) hours (p<0.001). There was no significantly differentproportion of adverse event found in both groups. Conclusions: Nifedipine and terbutaline sulfate have relatively same efficacy to vanish uterine contraction for prematurity management. ;Background: Preterm labour is considered as one of problems frequentlyencountered in obstetric and ginecologic department. To date, the incidence ofprematurity is still high worldwide. Two things should be noted: uterine contractionand corticosteroid for lung maturity of the baby. Thus, a tocolytic agent may be usefulin these circumstances. To date, terbutaline sulfate is widely used as it is known asbeta agonist. Beside, nifedine, a calcium channel blocker, is also widely accepted. Theuse of beta agonist might contribute several adverse events related to the mother,including tachycardia, dispnea, and anxiety. Some physicians have begun to restrictits use. Objective: This study aimed to compare the efficacy of slow releasenifedipine and terbutaline sulfate injection as a tocolytic agent for preterm labour.Methods: This is a randomized clinical trial unblinding. Subjects were pregnantwomen with prematurity (below 34 weeks of gestational age) at CiptoMangunkusumo hospital. Results: From a total of 60 subjects, 56 subjects (93.3%)had no contraction after given tocolytic (27 subjects (90.0%) in nifedipine group and29 subjects (96.7%) in terbutaline sulfate group; (p= 0.61). Subjects in nifedipinegroup lost their contraction after the drug was given with median time of 1.25 (0.672.00)hours while subjects in terbutaline sulfate group lost their contraction withmedian time of 0.50 (0.50-1.50) hours (p<0.001). There was no significantly differentproportion of adverse event found in both groups. Conclusions: Nifedipine and terbutaline sulfate have relatively same efficacy to vanish uterine contraction for prematurity management. , Background: Preterm labour is considered as one of problems frequentlyencountered in obstetric and ginecologic department. To date, the incidence ofprematurity is still high worldwide. Two things should be noted: uterine contractionand corticosteroid for lung maturity of the baby. Thus, a tocolytic agent may be usefulin these circumstances. To date, terbutaline sulfate is widely used as it is known asbeta agonist. Beside, nifedine, a calcium channel blocker, is also widely accepted. Theuse of beta agonist might contribute several adverse events related to the mother,including tachycardia, dispnea, and anxiety. Some physicians have begun to restrictits use. Objective: This study aimed to compare the efficacy of slow releasenifedipine and terbutaline sulfate injection as a tocolytic agent for preterm labour.Methods: This is a randomized clinical trial unblinding. Subjects were pregnantwomen with prematurity (below 34 weeks of gestational age) at CiptoMangunkusumo hospital. Results: From a total of 60 subjects, 56 subjects (93.3%)had no contraction after given tocolytic (27 subjects (90.0%) in nifedipine group and29 subjects (96.7%) in terbutaline sulfate group; (p= 0.61). Subjects in nifedipinegroup lost their contraction after the drug was given with median time of 1.25 (0.672.00)hours while subjects in terbutaline sulfate group lost their contraction withmedian time of 0.50 (0.50-1.50) hours (p<0.001). There was no significantly differentproportion of adverse event found in both groups. Conclusions: Nifedipine and terbutaline sulfate have relatively same efficacy to vanish uterine contraction for prematurity management. ]"

"Stainless steel 17-4 PH merupakan salah satu jenis breket ortodonti yang digunakan dalam kedokteran gigi karena memiliki sifat mekanik yang baik, ekonomis, dan biokompatibel. Namun, sifat mekanik dan fisiknya dapat beragam sesuai dengan temperatur heat treatment yang dilakukan. Tujuan penelitian ini adalah untuk mengetahui pengaruh aging di suhu 5400C terhadap analisa biodegradation material, kekerasan, ketahanan korosi, struktur mikro, dan biokompatibilitas in vitro dengan melihat lepasan ion Nikel yang dapat menimbulkan reaksi alergi di dalam artificial saliva. Proses age hardening dilakukan dalam dua tahapan. Langkah pertama adalah solution treatment dengan memanaskan spesimen pada temperatur 10800 C. Kemudian dilakukan proses pendinginan cepat sampai temperatur kamar menggunakan media oli. Langkah selanjutnya adalah proses aging di temperatur 5400C dengan waktu penahanan empat jam yang didinginkan di oli. Hasil akan dianalisa sebelum dan sesudah heat treatment menggunakan mikroskop optik untuk melihat perubahan mikrostruktur, EDS-SEM untuk membuktikan terbentuknya presipitat, metode polarisasi untuk mengetahui perubahan laju korosi material, uji hardness dengan Vickers, dan biokompatibilitas in vitro dengan cara merendam sampel dalam artifisial saliva selama 15, 21 dan 28 hari untuk melihat perbandingan jumlah ion nikel yang terlepas menggunakan atomic absorption spectroscopy. Morfologi permukaan sebelum dan sesudah periode perendaman dianalisa menggunakan SEM. Hasil penelitian menunjukan bahwa sampel mengalami hardening sebesar 16% dari kekerasan awal 35 HRC menjadi 41 HRC. Laju korosi material menurun setelah heat treatment dari 0.26072 mm/year menjadi 0,020012 mm/year. Optical microscope menunjukkan perubahan mikrostruktur menjadi martensit temper dan δ-ferrite, serta tumbuhnya presipitat di sekitar batas butir. Analisa EDS-SEM menunjukkan presipitat Cu terbentuk setelah proses pemanasan dan memicu terbentuknya fasa Ni-rich di sekitar presipitat Cu. Gambar SEM menunjukkan adanya scale dan micro-pit yang semakin besar seiring dengan peningkatan periode perendaman ditandai dengan peningkatan weight loss material. Hasil ion nikel yang terlepas <0,09 mg/L selama periode perendaman. Hasil penelitian membuktikan bahwa ion logam dalam kondisi eksperimental adalah baik karena konsentrasi di bawah nilai kritis yaitu 600 - 2500 μg untuk mengurangi risiko alergi dan di bawah tingkat asupan harian makanan sebesar 300-500 μg sehingga tergolong material yang biokompatibel untuk aplikasi ortodonti.

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Stainless steel 17-4 PH is one of a commercial orthodontic brackets type that has been used today in the field of dentistry because it has good mechanical properties, economical value, and biocompatible although the mechanical properties can be varied depends on the temperature of age hardening. The aim of the research is to study the effect of age hardening at 5400C on biodegradation of material, alteration hardness, corrosion resistance, microstructure, and biocompatibility in vitro to determine the ion release of Nickel concentration in artificial saliva. The age hardening treatment is done by 2 steps. Firstly, solution treatment at 10800C, then quench to room temperature with oil medium. Secondly, the material is tempered at 5400C for 4 hours, then quench with oil medium. Sample is analyzed before and after heat treatment using optical microscope to see the change in microstructure, EDS-SEM analysis to prove the forming of precipitate, polarization method to measure the corrosion rate and hardness test using Vickers method to identify the hardness of material. Biocompatibility in vitro is tested after immersing the material in artificial saliva for 15, 21, and 28 days to demonstrate and compare the ion release of Nickel concentration using atomic absorption spectroscopy. The surface morfology of stainless steel 17-4 PH is investigated using Scanning Electron Microscop (SEM) before and after immersing the sample in the period of time. The result showed that there was 16% increase of hardening effect which results to the change of hardness from 35 HRC to 41 HRC. The corrosion rate decreased after heat treatment, from 0.26072 mm/year to 0.020012 mm/year. Optical microscope showed the microstructure of heat treated stainless steel were tempered-martensite and δ-ferrite, with precipitate along grain boundaries. EDS-SEM analyzed that Cu precipitates were formed because of age hardening and it was found that there was an enrichment of Ni at the Cu precipitate-matrix interface. SEM captured scale and the micro-sized pitting were getting bigger along the increasing of immersing time which can be proved by the increasing of weight loss. Nickel ion release test showed that the value was below 0,09 mg/L for all immersing periods. Results showed that metal ions released in this experimental condition were well below the critical value which is 600 ? 2500 μg to induce allergy and below daily dietary intake level (300-500 μg) and it is considered to be a biocompatible material for orthodontic application."

"ABSTRAKTeknologi pelepasan obat jangka panjang diinginkan untuk mengobati penyakit mata, termasuk penyakit retinopati diabetik. Obat ini umumnya disampaikan melalui intraokular menggunakan injeksi intravitreal karena ketidakefektifan dan hambatan dari metode pemberian obat lainnya. Namun, frekuensi injeksi yang tinggi dapat menyebabkan beberapa kerugian, seperti ketidaknyamanan pasien dan beberapa komplikasi. Oleh karena itu, diperlukan sistem yang sempurna untuk mendapatkan pelepasan jangka panjang dan terkontrol. Untuk membentuk sistem seperti itu, Poly Lactic Acid PLA nanopartikel polimer digunakan untuk membungkus obat dexamethasone. Persiapan nanopartikel menggunakan metode penguapan pelarut-emulsifikasi. Selain itu, untuk meningkatkan stabilitas dan interaksi dengan asam hyaluronic dan vitreous, surfaktan kationik DDAB didodecyldimethylammonium bromide ditambahkan untuk modifikasi permukaan. Variasi surfaktan yang digunakan adalah DDAB 0,5 dan PVA-DDAB-0,5 . Uji rilis dilakukan selama 24 hari, dengan interval sampling 48 jam T = 35 C . Data menunjukkan bahwa stabilitas DDAB di permukaan dapat mencapai lebih lama dalam PLA-PVA-DDAB 0,5 dibandingkan dengan PLA-DDAB 0,5 . Setelah 24 hari, pelepasan kumulatif PLA-PVA-DDAB 0,5 mencapai 67,53 sementara PLA-DDAB 0,5 mencapai 89,2.

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ABSTRACTLong term drug release technology is desirable to treat ocular diseases, including diabetic retinopathy disease. The drug is commonly delivered via intraocular using intravitreal injecton due to ineffectiveness and obstacles of other drug delivery methods. However, the high frequency of injection can lead to several disadvantages, such as the patients rsquo inconvenience and several complications. Therefore, a perfect system to obtain long term and controlled release is required. To establish a such system, Poly Lactic Acid PLA polymer nanoparticles is used to encapsulate dexamethasone drug. The preparation of the nanoparticles uses emulsification solvent evaporation method. Moreover, to increase stability and interaction with the hyaluronic acid and vitreous, cationic surfactant DDAB didodecyldimethylammonium bromide is added for surface modification. Variations of surfactant used are DDAB 0.5 and PVA DDAB 0.5 . Release test was conducted for 24 days, with sampling interval of 48 hours T 35 C . The data show that the DDAB stability in the surface can reach longer in PLA PVA DDAB 0.5 comparing to PLA DDAB 0.5 . After 24 days, PLA PVA DDAB 0.5 cumulated release reached up to 67.53 while PLA DDAB 0.5 reached up to 89.2. "

"Penjadwalan produksi adalah hal yang penting dilakukan dalam perusahaan agar permintaan konsumen terpenuhi tepat waktu, sehingga daya saing perusahaan dan kepuasan konsumen tetap terjaga. Salah satu tipe penjadwalan berdasarkan aliran proses produksi adalah penjadwalan flowshop. Dalam permasalahan penjadwalan flowshop mempunyai beberapa konstrain yang potensial untuk dikembangkan, salah satunya release time. Penelitian ini mengembangkan model dari penjadwalan flowshop dengan mempertimbangkan release time serta mempunyai fungsi tujuan meminimasi makespan dan total lateness pada perusahaan yang bersifat mass production. Hasil penelitian menunjukan bahwa formulasi model usulan menghasilkan performansi yang baik dari model yang digunakan oleh perusahaan, baik dari nilai makespan ataupun total lateness.

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Production scheduling is an important thing done in the company so that consumer demand can be fulfilled on time, so that the company 39's competitiveness and customer satisfaction are maintained. One type of scheduling based on production process is flow shop scheduling. In flowshop scheduling problems have some potential constraints to develop, one of which is release time. This research develops a model of flowshop scheduling by considering release time and has purpose function to minimize makespan and total lateness in a mass production company. The results indicate that the proposed model formulation yielded a good performance of the model used by the company, either from the value of makespan or total lateness."

"ABSTRAKPeneliti ingin melihat probabilitas dan pengaruh mekanisme informasi dalam melakukan peluncuran produk di pasar dengan sampel sebanyak 275 proyek crowdfunding di 5 industri teratas ASEAN-five countries pada platform Kickstarter. Untuk mendapatkan hasil analisis tersebut, peneliti menggunakan regresi probit dan average marginal effect dalam melakukan pengolahan data. Jumlah backers merupakan salah satu variabel mekanisme informasi yang memiliki hubungan yang positif dan signifikan terhadap variabel dependen dengan probabilitas perubahan rata-rata sebesar 0,331 percentage points. Hasil tersebut menunjukkan bahwa inisiator proyek menggunakan jumlah backers sebagai salah satu alat ukur untuk membuat keputusan dalam melakukan peluncuran produk. Terdapat empat variabel independent lainnya yaitu average pledge, pledge ratio, total pledge dan komunitas yang digunakan untuk melihat pengaruh dan probabilitas terhadap variabel dependen penelitian.

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ABSTRACT

The researcher wanted to see the probability and influence of the information mechanism in launching products on the market with a sample of 275 crowdfunding projects in the top 5 industries of ASEAN-five countries on the Kickstarter platform. To get the results of the analysis, researchers used probit regression and the average marginal effect in processing data. The number of backers is one of the information mechanism variables that has a positive and significant relationship to the dependent variable with the probability of change averaging 0.331 percentage points. These results indicate that the initiator of the project uses the number of backers as one measure to make decisions in carrying out product launches. There are four other independent variables, namely average pledge, pledge ratio, total pledge and community that are used to see the effect and probability of the dependent variable of the study."