Hasil Pencarian  ::  Simpan CSV :: Kembali

"ZnO nanoparticles were successfully synthesized by a solochemical method using zinc chloride as the precursor in a sodium hydroxide solution with ZnCl2:NaOH ratios of 1:2 and 1:3. The effects of the thermal treatment on the functionalities of the nanoparticles were investigated by comparing calcined ZnO with uncalcined ZnO. Calcined ZnO underwent a drying process at 120°C, followed by calcination at 500°C, while uncalcined ZnO underwent the drying process only. The synthesized nanoparticles were characterized by XRD and FESEM-EDX analysis. The photoactivity of synthesized ZnO was evaluated through methylene blue degradation. In addition, ZnO nanofluids were synthesized by dispersing nanoparticles into the base fluid. The nanofluidic stability in the presence of a Palm Oil-Based Primary Alkyl Sulphate (palmPAS) surfactant were investigated using a spectrophotometer UV-vis with varied PalmPAS concentrations. XRD and FESEM analysis showed that the nanoparticles exhibited a hexagonal wurtzite structure, and confirmed that the particle size increased on calcination. All the synthesized ZnO nanoparticles exhibited good photoactivity under UV light irradiation due, to some extent, to their good crystallinity. The calcined ZnO from the ZnCl2:NaOH ratio of 1:3 offered the best photocatalytic performance compared to its ZnO counterparts. It was also found that the nanofluids of uncalcined ZnO from the ZnCl2:NaOH ratio of 1:3, at a ZnO:palmPAS ratio of 1:9, offered the best stability."

"ABSTRAKNama : Andi CleveriawanProgram studi : Ilmu Kesehatan MataJudul : Perbandingan Hasil Trabekulektomi MMC Dengan Dan Tanpa Viskoelastik Sodium Hyaluronat Terhadap Morfologi Bleb Pada Glaukoma PrimerPembimbing : Widya Artini, Joedo Prihartono Penelitian ini bertujuan mengetahui manfaat pemberian viskoelastik sodium hyaluronat pada pasien glaukoma primer yang dilakukan bedah trebekulektomi dengan mitomicin C di RSCM. Desain penelitian ini adalah uji klinis prospektif tersamar tunggal. Sebanyak 34 mata 33 pasien yang masing- masing terbagi menjadi 2 kelompok, yaitu 17 mata diberikan viskoelastik dan 17 mata pada kelompok yang diberikan tanpa viskoelastik. Pemeriksaan Tekanan bola mata TIO diukur pada hari 1, minggu 1, minggu 2, dan minggu ke 4 pasca operasi. Penilaian bleb dengan menggunakan Moorfield Bleb Grading System MBGS dilakukan pada minggu ke 4.Setelah 1 bulan pasca operasi, pada pemeriksaan MBGS area sentral, area maksimal, ketinggian, dan vaskularitas pada kedua kelompok tidak ditemukan perbedaan bermakna. Namun pada pemeriksaan TIO minggu 1 didapatkan terdapat perbedaan bermakna pada kelompok viskoelastik sebesar 8,94 3,36 dan pada kelompok tanpa viskoelastik sebesar 11,41 3,72 p = 0,034 . Meskipun pada TIO pada minggu ke 4 tidak didapatkan perbedaan bermakna pada kelompok viskoelastik sebesar 11,70 2,46 dan tanpa viskoelastik sebesar 12,35 3,08 p = 0,504 . Perubahan TIO pada kelompok viskoelastik didapatkan sebesar 21,88 12,29 dan tanpa viskoelastik sebesar 23,29 9,25 p = 0,352 . Pada pemeriksaan OCT ketinggan bleb pada kedua kelompok juga tidak didapatkan perbedaan bermakna yaitu 1,28 0,325 dan 1,17 0,324 p = 0,321 .Tekanan intra okular dan morfologi bleb pasca tindakan trabekulektomi MMC dengan penambahan viskoelastik tidak berbeda bermakna statisik namun memiliki kecenderungan lebih baik dibandingkan tanpa vikoelastik. Kata kunci :Glaukoma primer, MBGS, sodium hyaluronat, trabekulektomi, viskoelastik

---

ABSTRACTName Andi CleveriawanStudy Program OphthalmologyTitle Comparison Of Trabeculectomy MMC With And Without Sodium Hyaluronate Viscoelastic Results To Bleb Morphology In Primary GlaucomaCounsellor Widya Artini, Joedo Prihartono To determine the benefits of viscoelastic sodium hyaluronate in primary glaucoma patients performed by trebeculectomy surgery with mitomycin C in RSCM. Clinical prospective single blinded clinical trial. A total of 34 eyes 33 patients , each split into 2 groups, 17 eyes were given viscoelastic and 17 eyes in the group administered without viscoelastic. Examination of Eye Pressure IOP was measured on day 1, week 1, week 2, and week 4 postoperatively. Assessment of bleb using Moorfield Bleb Grading System MBGS was performed at week 4. After 1 month postoperatively, MBGS examination of central area, maximal area, height, and vascularity in both groups found no significant difference. However, at week 1 IOP examination, there were significant differences in the viscoelastic group of 8.94 3.36 and in the no viscoelastic group of 11.41 3.72 p 0,034 . Although in the IOP at week 4 there was no significant difference in the viscoelastic group of 11.70 2.46 and without viscoelastic at 12.35 3.08 p 0,504 . IIO changes in the viscoelastic group were found to be 21.88 12.29 and without viscoelastic at 23.29 9.25 p 0.352 . In the OCT examination, bleb height in both groups also did not get significant difference that is 1.28 0.325 and 1.17 0.324 p 0.321 . Intraocular pressure and bleb morphology post trabeculectomy MMC action with viscoelastic addition did not differ significantly statistically but had a better tendency than without vicoelastic. Keywords MBGS, primary glaucoma, sodium hyaluronate, trabeculectomy, viscoelastic"

"Kombinasi TiO2 dan PalmPAS sebagai detergen yang stabil untuk mengangkat dan mendegradasi kotoran berupa methylene blue serta menghasilkan limbah hasil pencucian dengan PalmPAS pada air sadah telah dilakukan. Penelitian dilakukan dengan memvariasikan komposisi PalmPAS dan TiO2 dengan pengaturan pH dan proses sonikasi. Semua variasi yang dibuat menunjukkan kestabilan yang baik. Laju pengendapan TiO2 dalam detergen dibawah 1% selama 3 jam dan penurunan konsentrasi PalmPAS dibawah 2 % selama 14 hari. Komposisi optimum yang didapat adalah 0.1% TiO2-0.4% PalmPAS dengan pengangkatan kotoran sebesar 82% dan degradasi kotoran sebesar 92%. Pengujian pada air sadah dengan konsentrasi ion Ca2+ 20-60 ppm menyebabkan penurunan penangkatan kotoran sebesar 20-51% dan penurunan degradasi kotoran sebesar 33-43%.

---

Combination of TiO2 and PalmPAS as a stable detergent to remove and degradate methylene blue as dirt and produce a clean waste with minimum concentration of PalmPAS has been investigated. The research varies PalmPAS dan TiO2 concentration with pH adjustment and sonication process. All the variation exhibits good stability. Precipitation rate of TiO2 is below 1% after 3 hours preparation and the decrease in PalmPAS concentration is below2% after 14 days preparation. 0,1% TiO2-0,4% PalmPAS shows the most optimum concentration that have detergency up to 82% of the dirt and degrade 92% of the dirt. Detergent performance in hardness water with ion Ca2+ concentration from 20 to 60 ppm decreases the detergency of dirt by 20-51% and also decrease the dirt degradation by 33-43%."

"Detergent with composition originated from renewable material are being widely developed to replace detergent that contains LAS (Linear Alkylbenzene Sulfonate), which is originated from oil and hard to decompose. This undergaduate thesis proposed a detergent based on natural ingredients TiO2 and Palm PAS (Palm Oil- Based Primary Alkyl Sulfate). Palm PAS are able to remove dirt, TiO2 are able to degrade dirt and leftover surfactant. After finding the stable and optimum composition of TiO2 and Palm PAS in deionized water, sodium carbonate was added because in the previous research the formulated detergent has only been tested in deionized water. It is hypothesized that water hardness will decrease the performance of detergent. Hard water used in this research was CaCl2 because it was found widely in the water used for washing. The initial characterization of the solution was done using PSA while most of the absorbance determination was done using Uv-vis spectrometer."

"Penelitian terhadap sintesis nanopartikel magnetik menggunakan biologi sebagai agen pereduksi cukup pesat dikembangkan, menimbang proses ny yang ramah lingkungan dan dapat meminimalisir penggunaan produk kimia berbahaya. Penelitian dilakukan dengan menggunakan esktrak daun Matoa Pometia pinnata. Parameter proses seperti pH larutan menjadi pertimbangan dalam proses pembentukan nanopartikel magnetik sehingga dilakukan variasi dengan waktu penambahan NaOH. Berhasilnya proses biosintesis nanopartikel magnetik dapat terlihat dari perubahan warna larutan serta terdapatnya partikel yang tertarik saat didekatkan dengan magnet.Karakterisasi sifat optik yang dihasilkan dari proses biosintesis dipelajari menggunakan UV-Vis, lalu karakterisasi nanopartikel dipelajari menggunakan TEM, PSA, XRD, dan TGA. Ukuran nanopartikel berkisar 5-50 nm dan beraglomerasi, fasa magnetik yang terbentuk yaitu Fe3O4. Dari semua hasil karakterisasi tersebut memperlihatkan bahwa penambahan NaOH berpengaruh terhadap pembentukan morfologi nanopartikel magnetik. Selain itu variasi waktu pada penambahan NaOH akan mempengaruhi kristalinitas pada nanopartikel magnetik.

---

Research on the synthesis of magnetic nanoparticles using biology as reducing agents is a fairly rapid method developed, weighing the process of being environmentally friendly and able to minimize the use of hazardous chemical products. The study was conducted using Matoa leaves extract Pometia pinnata. Process parameters such as solution pH is considered in the process of forming magnetic nanoparticles so that they are varied with the time of addition of NaOH. The success of the biosynthesis of magnetic nanoparticles can be seen from the color changes in the solution and the presence of particles attracted when held close to magnet.

The characterization of the optical properties resulting from the biosynthesis process was studied using UV Vis, then the nanoparticle characterization was studied using TEM, PSA, XRD, and TGA. The size of nanoparticles ranged from 5 50 nm and aglomerated, the magnetic phase formed is Fe3O4. Of all the characterization results showed that the addition of NaOH influenced the morphology of magnetic nanoparticles. In addition, the time variation in the addition of NaOH will influence crystallinity in magnetic nanoparticles. "

"Tandan Kosong Sawit (TKS) merupakan salah satu jenis limbah padat utama yang banyak dihasilkan oleh pabrik kelapa sawit di Indonesia setiap tahunnya. Limbah ini mengandung lignoselulosa yang dapat dikonversi menjadi beberapa produk bernilai jual tinggi, salah satunya adalah senyawa furfural yang diperoleh melalui proses hidrolisis hemiselulosa. Namun, sifat struktur biomassa lignoselulosa yang sulit dipecah mengharuskan langkah praperlakuan yang efisien untuk meningkatkan hasil delignifikasi agar membuat hemiselulosa lebih mudah dihidrolisis. Praperlakuan TKS dengan metode basa NaOH berbantuan gelombang mikro dapat menjadi alternatif yang baik karena metode ini efektif dari segi waktu dan biaya dalam meningkatkan kinerja delignifikasi. Penelitian ini melakukan optimasi kondisi proses menggunakan Response Surface Methodology (RSM). Kondisi yang dioptimasi adalah daya gelombang mikro, konsentrasi NaOH, dan waktu radiasi. Nilai kondisi optimasi model RSM adalah 832,9 Watt untuk daya gelombang mikro, 2,7% untuk konsentrasi NaOH, dan 8,9 menit untuk waktu radiasi dengan persentase delignifikasi sebesar 88,10%. Sedangkan kondisi optimasi saat percobaan RSM adalah daya gelombang mikro sebesar 840 Watt, konsentrasi NaOH sebesar 2%, dan waktu radiasi selama 9 menit dengan persentase delignifikasi yang dicapai adalah 73,75%. Hasil optimasi RSM juga menunjukkan bahwa efek interaktif yang paling signifikan dengan kinerja delignifikasi adalah interaksi antara daya gelombang mikro dan waktu radiasi. Pengaruh dan interaksi variabel yang diuji terhadap kinerja delignifikasi dijelaskan pada penelitian ini. Kinerja delignifikasi TKS yang maksimal juga terbukti dari hasil uji SEM dan uji XRD yang disajikan pada penelitian ini. Modifikasi struktural dan perubahan fisik pada TKS diamati menggunakan uji SEM, sedangkan indeks kristalinitas TKS ditentukan dengan menggunakan uji XRD.

---

Oil Palm Empty Fruit Bunches (OPEFB) is one of the main types of solid waste produced by palm oil mills in Indonesia every year. This waste contains lignocellulose which can be converted into several high-value products, one of which is furfural compounds obtained through the hemicellulose hydrolysis process. However, the nature of the structure of lignocellulosic biomass that is difficult to break down requires efficient pretreatment steps to improve the delignification results to make hemicellulose easier to hydrolyze. Pretreatment of OPEFB fibers using Gelombang Mikro-assisted NaOH base methods, that it can be good alternative because this method is effective in terms of time and cost in improving delignification performance. This study optimizes process conditions using Response Surface Methodology (RSM). The conditions optimized are microwave power, NaOH concentration, and radiation time. The optimization condition of the RSM model is 832.9 Watts for microwave power, 2.7% for NaOH concentration, and 8.9 minutes for radiation time with delignification percentage of 88.10%. While the optimization conditions during the RSM experiment were respectively 840 Watts microwave power, 2% NaOH concentration, and 9 minutes radiation time with the percentage of delignification achieved was 73.75%. The results of RSM optimization also show that the most significant interactive effect with delignification performance is the interaction between Gelombang Mikro power and radiation time. The influence and interaction of the variables tested on the performance of delignification are explained in this study. Maximum delignification performance of OPEFB was also evident from the results of the SEM test and the XRD test presented in this study. The structural modification and physical changes in OPEFB were observed using SEM test, while crystallinity index of OPEFB was determined by using XRD test."

"ABSTRAKReduksi selektif bijih nikel laterit tipe saprolitik dengan kandungan Ni, Fe, MgO, dan SiO2 masing-masing sebesar 1,71%, 18,93%, 13,4%, dan 24,64% telah dilakukan dengan variasi penambahan zat aditif sodium hidroksida dan sulfur. Reduktor yang digunakan terdiri dari dua jenis, yaitu lignite dan batubara sub-bituminous dengan temperatur reduksi divariasikan menjadi 900oC, 1000oC, dan 1100oC, masing-masing selama 60 menit. Kadar nikel meningkat dari 3,91% menjadi 4,2% dengan kenaikan temperatur dari 900oC hingga 1100oC, dan perolehan nikel juga mengalami peningkatan dari 83% pada suhu reduksi 900oC menjadi 91% pada suhu 1100oC. Penambahan sulfur menyebabkan kenaikan recovery nikel dari 60% pada penambahan 0% sulfur menjadi 87% dengan penambahan 9% sulfur. Reduksi tanpa penambahan NaOH hanya mampu mencapai recovery nikel maksimum sebesar 67%, sedangkan penambahan 16,4% NaOH mampu meningkatkanrecovery secara signifikan hingga 89%. Reduksi yang dilakukan dengan memanfaatkan reduktor lignite menghasilkan kecenderungan recovery Ni yang lebih tinggi dibandingkan dengan reduktor sub-bituminous. Reduksi dengan reduktor sub-bituminous menunjukkan hasil perolehan nikel maksimum 67%, sedangkan pemanfaatan reduktor lignite mampu menghasilkan nikel dengan perolehan hingga 89%.Fasa-fasa yang terbentuk pada reduksi selektif nikel laterit dengan penambahan NaOH, antara lain forsterite (Mg2SiO4), olivine [(Mg,Fe)2SiO4], taenite (FeNi), dan natrium silikat (Na2Si2O5). Sedangkan sulfur berperan penting dalam pembentukan fasa pyroxene [(Ca,Mg,Fe)2Si2O6] dan mencegah terjadinya pembentukan fasa olivine dan forsterite yang bersifat menyelubungi oksida nikel yang hendak direduksi. Selain itu sulfur juga berperan penting dalam prosesaglomerasi butiran metalik hingga 50μm dengan penambahan sulfur sebesar 9% dari ukuran butiran yang hanya mencapai 5μm dengan penambahan 0,5% sulfur.

---

ABSTRACTSelective reduction of nickel laterit saprolitic ore with Ni, Fe, MgO, and SiO2 contents 1.71%, 18.93%, 13.4%, and 24.64% respectively, has been conducted with some variated sodium hydroxide and sulphur amounts. Reduction has been done by usingtwo types of reductors, such as lignite and sub-bituminous coal at various reduction temperatures (900oC, 1000oC, and 1100oC) along 60 minutes of reduction timefor each temperatures. Nickel grades increased from 3.91% to 4.2% due to increasing reduction temperature from 900oC to 1100oC. Nickel recovery rose up regarding to increasing temperature from 83% at 900oC to 87% at 1100oC. Sulphur addition gave significant effects on resulted nickel recoveries, from 60% without any addition to 87% with addition of 9% sulphur. Selective reduction with no NaOH addition could only reach 67% of nickel recovery, while 89% nickel could be attained with 16.4% of NaOH. The usage of lignite as solid reductor indicated higher nickel recoveries compared to those with sub-bituminous coal. Selective reduction using sub-bituminous as reductor had maximum nickel grade at 67%. Meanwhile, 89% of nickel recovery could be achieved with employing lignite as solid reductor.Some phases formed after reduction of saprolitic nickel ore with sodium hydroxide addition, such as forsterite (Mg2SiO4), olivine (Mg,Fe)2SiO4, taenite (FeNi), dan natrium silikat (Na2Si2O5). Whereas, sulphur had important role in the formation of iron-rich silicate (pyroxene) phase and impediment of the crystallization of olivine and forsterite phases that inhibit nickel and iron oxides to be reduced. According to backscatter imagesby SEM, fact that sulphur can induce the metallic grain agglomeration is also found. The grain size with excessive sulphur addition (9%) is 50μm, while the addition of only 0.5% sulphur had maximum metallic grain size by 5μm"

"The addition of alumina and wollastonite in geopolymer resin is expected to increase the thermal behavior of the geopolymer matrix composite. In this work, fine granules of solid alumina and acicular wollastonite used as filler were mixed with a fly ash-based geopolymer resin paste to form a composite matrix. The filler additions were 2.5% to 10.0% of the total weight with sodium silicates and sodium hydroxide used as activators. The results showed that the addition of alumina and wollastonite as filler did not have much effect on the flexural and compressive strength of the geopolymer matrix composite at room temperature. Wollastonite fiber, which was added in the form of a short-sized fiber, only produced a very small bridging effect. Nevertheless, alumina filler composite showed a good result after being exposed to a temperature at 200°C, although the strength was reduced as the temperature increased. Moreover, wollastonite fibers only managed to maintain 50% of their flexural strength after 2 hours exposure at a temperature of 200°C due to the damage of the wollastonite fiber."