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"Dalam upaya peningkatan jumlah produksi cadangan energi hijau, pemanfaatan molekul hidrogen (H2) menjadi salah satu cara yang menjanjikan. Pemecahan air merupakan proses pemisahan molekul hidrogen dari air dengan memanfaatkan sinar matahari. Material fotokatalis dapat membantu meningkatkan efisiensi proses pemecahan air dengan menghasilkan pasangan pembawa muatan untuk berlangsungnya proses reaksi redoks air. Belakangan ini, material Graphitic Carbon Nitride (GCN) cukup banyak diteliti untuk aplikasinya sebagai fotokatalis penyerapan cahaya tampak yang sesuai dengan aplikasi pada proses pemecahan air. Modifikasi material GCN ini menjadi fokusan penelitian ini dengan menggunakan strategi in-situ elemental doping logam alkali natrium (Na) dengan tujuan memodifikasi struktur celah pitanya serta mengetahui perbedaan pengaruh dari penggunaan garam natrium yang berbeda (NaOH, NaCl, Na2CO3). Material Na-doped GCN disintesis dari prekursor urea yang ditambahkan garam natrium menggunakan metode dekomposisi termal menggunakan tungku muffle pada suhu 520°C selama 3 jam waktu tahan dengan laju pemanasan sebesar 5°C/menit. Urea dipilih karena fitur keunggulannya yaitu menghasilkan struktur berpori serta area permukaannya yang dihasilkan besar. sehingga dapat meningkatkan proses evolusi hidrogen. Sampel dilakukan karakterisasi SEM-EDS, XRD, FTIR, dan UV-Vis. Dalam penggunaan 3 jenis garam natrium yang berbeda, tidak ditemukan pengaruh yang signifikan pada setiap aspek karakteristik material GCN kecuali pada beberapa aspek yaitu pada sifat derajat kristalinitasnya di mana penggunaan garam Na2CO3 menghasilkan derajat kristalinitas yang paling rendah serta tingkat distorsi pada struktur in-plane heptazine yang paling besar. Terjadi perbedaan pengaruh pada karakteristik sifat optik dan elektronik material GCN di mana penggunaan garam Na2CO3 menghasilkan kemampuan respon terhadap radiasi cahaya tampak yang paling baik serta menghasilkan energi celah pita yang paling rendah (2,63 eV). Sehingga dapat diketahui bahwa gaaram natrium Na2CO3 merupakan garam yang paling efektif dalam menginkorporasikan ion dopant Na+ ke dalam struktur GCN.

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In order to increase the amount of production of green energy reserves, the utilization of molecular hydrogen (H2) is a promising way. Water splitting is the process of separating hydrogen molecules from water by utilizing sunlight. Photocatalyst materials can help increase the efficiency of the water splitting process by producing charge carrier pairs for the water redox reaction process to take place. Recently, Graphitic Carbon Nitride (GCN) material has been extensively studied for its application as a visible light absorption photocatalyst which is suitable for applications in water splitting processes. This modification of the GCN material became the focus of this study using the in-situ strategy of elemental doping of the alkali metal sodium (Na) with the aim of modifying its band gap structure and knowing different effects in using different sodium salts (NaOH, NaCl, Na2CO3). Na-doped GCN material was synthesized from urea precursor added with sodium salt using the thermal decomposition method using muffle furnace at 520°C for 3 hours holding time with a heating rate of 5°C/minute. Urea was chosen because of its superior features, namely it produces a porous structure in GCN material and produces a large surface area. Thus can enhance the process of the hydrogen evolution. Samples were subjected to SEM-EDS, XRD, FTIR, and UV-Vis characterization. In the use of 3 different types of sodium salt, no significant effect was found on any aspect of the GCN material characteristics except for several aspects, namely the degree of crystallinity where the use of Na2CO3 salt resulted in the lowest degree of crystallinity and the degree of distortion in the heptazine in-plane structure which the biggest. There are differences in the effect on the optical and electronic characteristics of GCN materials where the use of Na2CO3 salt produces the best response to visible light radiation and produces the lowest band gap energy (2.63 eV). So it can be concluded that sodium salt Na2CO3 is the most effective salt in incorporating dopant ion Na+ into the GCN structure."

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Berdasarkan data kualitas air IPA 3 Gading Serpong, mangan pada air baku melebihi standar 0,1 mg/L dan kadar sisa klor air produksi masih di bawah standar 0,2-1 mg/L. Untuk menentukan dosis optimum NaOCl dalam menurunkan mangan air baku dan meningkatkan sisa klor air produksi serta menganalisis perbandingan proses pengolahan air dengan oksidasi dan tanpa oksidasi, dilakukan penelitian dengan simulasi proses pengolahan air pada skala laboratorium. Percobaan tahap pertama bertujuan menentukan dosis optimum NaOCl dalam menurunkan kandungan mangan dengan variasi dosis NaOCl 4, 6, 8, dan 10 ppm. Percobaan tahap kedua bertujuan membandingkan proses pengolahan air dengan dan tanpa oksidasi. Percobaan tahap ketiga dilakukan untuk melihat hubungan oksidasi terhadap post-klorinasi. Parameter yang digunakan dalam penelitian adalah mangan, kekeruhan, pH, dan sisa klor. Hasil penelitian menunjukkan dosis optimum untuk oksidasi mangan adalah 8 ppm dengan penurunan mangan sebesar 29%. Hasil kualitas air terbaik dimiliki oleh sampel yang disertai proses oksidasi 8 ppm dengan penambahan klor 60 ppm pada proses post-klorinasi yang memiliki kekeruhan 0,97 NTU, pH 7,7, dan sisa klor 0,26 mg/L. Proses oksidasi dan post-klorinasi tersebut dapat diimplementasikan pada IPA 3 Gading Serpong dengan mudah tanpa penambahan sumber daya yang signifikan.

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WTP 3 Gading Serpong water quality data shows that raw water manganese surpasses 0,1 mg/L and treated water residual chlorine remains below 0,2-1 mg/L. A laboratory-scale simulation was used to identify the optimal dose of NaOCl to reduce raw water manganese and increase treated water residual chlorine, as well as to compare the water treatment process with and without oxidation. The first phase of the trial tested NaOCl doses of 4, 6, 8, and 10 ppm to reduce manganese levels. The second phase trial compares water treatment processes that include and exclude oxidation. In the third phase, the relationship between oxidation and postchlorination was investigated. Manganese, turbidity, pH, and residual chlorine are the study's parameters. The study found that an optimal dose of 8 ppm for manganese oxidation resulted in a 29% reduction in manganese. The best results for water quality are obtained with samples that have an oxidation process of 8 ppm and an addition of 60 ppm chlorine in the post-chlorination process with a turbidity of 0.97 NTU, a pH of 7.7, and a residual chlorine of 0.26 mg/L. The oxidation and post-chlorination processes can be implemented at WTP 3 Gading Serpong easily without adding significant resources.

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"Energi yang besar diperlukan untuk menghasilkan feronikel melalui proses pengolahan bijih nikel laterit. Pengolahan bijih nikel laterit kadar rendah akan menjadi tidak ekonomis. Saat ini, reduksi selektif dianggap sebagai proses yang potensial untuk menghasilkan nikel berkadar tinggi dalam pembuatan feronikel dan mulai banyak dilakukan penelitian untuk mendapatkan metode reduksi selektif yang ekonomis. Pada penelitian ini digunakan natrium sulfat, natrium karbonat, dan natrium klorida sebagai aditif dengan variasi dosis 5, 10, dan 15 berat. Batu bara antrasit dari Padang digunakan sebagai reduktor pada penelitian ini sebanyak 5 berat. Reduksi dilakukan pada variasi temperatur 950, 1050, dan 1150oC selama 60 menit. Proses separasi magnetik basah dengan kekuatan magnet 500 Gauss dilakukan pada tahapan setelah reduksi selektif untuk memisahkan konsentrat feronikel yang bersifat magnetik dan tailing pengotor yang bersifat non-magnetik. Karakterisasi bijih laterit hasil reduksi dilakukan menggunakan X-ray Diffraction XRD , mikroskop optik, dan Scanning Electron Microscope SEM yang dilengkapi Energy Dispersive X-ray Spectroscopy EDS . Konsentrat dan tailing hasil separasi magnetik diidentifikasi menggunakan X-ray Fluororescene XRF . Hasil penelitian ini menunjukkan bahwa pada penambahan 15 berat aditif dengan variasi temperatur reduksi, terlihat bahwa terjadi peningkatan yang signifikan pada kadar nikel yang dihasilkan dari proses separasi magnetik. Kadar nikel optimum didapatkan pada temperatur reduksi 1150 C dengan nilai 15,06 untuk penambahan aditif natrium sulfat; 2,18 untuk penambahan aditif natrium karbonat; dan 2,27 untuk penambahan aditif natrium klorida. Pada reduksi selektif yang dilakukan pada temperatur reduksi 1150 C selama 60 menit dengan variasi penambahan persentase berat aditif, terlihat bahwa terjadi peningkatan yang signifikan pada kandungan nikel. Dosis aditif optimum untuk masing-masing aditif diperoleh pada penambahan 15 berat.

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The extraction process of lateritic nickel ores to produce ferronickel required high energy. It will not be economical to process low grade lateritic nickel ores. Nowadays, selective reduction process is being a potential process to produce high grade nickel from low grade nickel ores and there are many reasearches to gain an economical method of this process. The recent work used sodium sulfate, sodium carbonate, and sodium chloride as additives with the variative dossage of 5, 10, and 15w.t. Antrachite coal from Padang used as reductant with the dossage of 5w.t. The reduction was done with variation reduction temperature of 950, 1050, and 1150oC for 60 minutes. Wet magnetic separation process was done afterwards to separate the magnetic particle feronickel as concentrate and the non magnetic particle gangue as tailing. It was done by 500 Gauss of magnet. The caracterization of reduced ore had been done using X ray Diffraction XRD, optical microscope, and Scanning Electron Microscope SEM completed by Energy Dispersive X ray Spectroscopy EDS. Concentrate and tailing of magnetic separation process had been observed by X ray Fluororescene XRF . The results of the recent work shows that the addition of 15w.t. of additive with the variation of reduction temperature obtained significantly increasing of nickel grade from magnetic separation process. The optimum nickel grade from the reduction temperature of 1150 C are 15,0625 for the addition of sodium sulfate, 2,1855 for the adition of sodium carbonate, and 2,2695 for the addition of sodium chloride. The result of selective reduction process at the reduction of temperature of 1150 C for 60 minutes with variation of additive dossage shows that the optimum dossage for each additive is 15w.t. "

"Scope and Method of Study: Typhoid and paratyphoid fever are still a major problem in developing countries viewed from epidemiological, laboratory, as well as clinical aspects. Reliable laboratory diagnosis is the blood culture. However, failure of the blood culture occurs, due to the bactericidal effect of blood (phagocytes, complement, and specific and nonspecific antibodies, among others). Microbiologists are challenged to improve the blood culture by adding sodium polyanethol sulphonate (SPS) in the media. SPS is capable to inactivate the blood bactericidal effect, is an effective anticoagulant, non-toxic to most pathogens, stable to high temperature, acid and alkaline solutions, and is water-soluble.The objective of this study is to compare bile culture plus 0.05% SPS to conventional bile culture for the growth of salmonella in blood. The result was evaluated by the rate of growth in both cultures after 1 minute, 4 hours and 12 hours (logarithmic phase). The number of organisms was calculated from growth on nutrient agar plates when the range-of growth were 30-300 colonies per 0.1 ml inoculum, and the dilution of both cultures.Findings and Conclusions: Fifty isolates representing five species of salmonellae has been tested and showed that the number of organisms per ml in the SPS bile culture was not significantly different compared to conventional bile culture. In conclusion, the SPS bile culture is the same as conventional bile culture for the growth of S. typhi, S. pa-atyphi A, B, C, and S. typhimurium in blood from healthy humans, with a blood-broth ratio of 1: 10."

"Sodium (Na) was found as one of chemical elements that able to disturb plants that grow along the Cikijing river. This river water that had been detected as contains high sodium,whereas the river water is still used by local famers to irigate their rice fields....."

"Saat ini sumber cadangan litium di dunia >70% hadir dalam bentuk brine water. Serangkaian penelitian telah dilakukan terhadap brine water yang ditemukan pada mata air Gunung Panjang, Ciseeng, Bogor untuk mengetahui pengaruh proses elektrolisis terhadap rasio Mg/Li yang terkandung di dalam brine. Pada penelitian, dilakukan proses elektrolisis terhadap brine water dengan variasi tegangan sebesar 15 V dan 20 V diikuti oleh pemanfaatan jembatan garam selama 60 jam elektrolisis berlangsung. Jenis uji karakterisasi yang dilakukan terhadap hasil penelitian meliputi uji ICP-OES untuk filtrat yang dihasilkan selama proses elektrolisis, serta XRD dan SEM-EDS untuk residu yang dihasilkan pada tiap variabel dengan nilai Mg/Li terkecil. Berdasarkan analisis yang dilakukan, diketahui bahwa proses elektrolisis mampu mempengaruhi nilai Mg/Li pada brine seiring dengan bertambahnya waktu, serta peningkatan arus dan penggunaan dari jembatan garam selama proses elektrolisis dilakukan. Rasio Mg/Li terkecil yang diperoleh untuk masing – masing variabel sebesar 2,96; 3,37; 4,31 serta 6,01 dengan variabel 15 V jembatan garam menghasilkan nilai rasio Mg/Li terkecil. Data analisis XRD menunjukkan 5 senyawa padat yang terbentuk meliputi Mg(OH)2 (brucite), Ca(OH)2 (portlandite), KCl(sylvite), LiCl dan NaCl (halite).

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Currently, >70% of the world's lithium reserves come in the form of brine water. A series of studies have been conducted on brine water found in mata air Gunung Panjang, Ciseeng, Bogor to determine the effect of electrolysis process on the Mg/Li ratio contained in the brine. In the research, the electrolysis process was carried out on brine water with voltage variations of 15 V and 20 V followed by the utilization of salt bridges for 60 hours of electrolysis. The types of characterization tests carried out on the research results include ICP-OES tests for the filtrate produced during the electrolysis process, as well as XRD and SEM-EDS for the residue produced in each variable with the smallest Mg/Li value. Based on the analysis conducted, it is known that the electrolysis process affects the Mg/Li value in the brine as time increases, as well as the increase in current and the use of the salt bridge during the electrolysis process. The smallest Mg/Li ratio obtained for each variable was 2.96; 3.37; 4.31 and 6.01 with the 15 V salt bridge variable producing the smallest Mg/Li ratio value. XRD analysis data showed 5 solid compounds formed including Mg(OH)2 (brucite), Ca(OH)2 (portlandite), KCl (sylvite), LiCl and NaCl (halite)."

"Latar Belakang: Irigasi endodontik konsentrasi tinggi Natrium Hipoklorit (NaOCl) 5% telah banyak dilaporkan menurunkan viabilitas sel punca pulpa (hDPSCs) namun merupakan bahan irigasi pilihan untuk perawatan endodontik. Sehingga dibutuhkan larutan lain untuk menetralkan efek NaOCl seperti Sodium thiosulfate (STS) yang bersifat antioksidan agar potensi anti mikroba NaOCl tetap baik namun tidak mempengaruhi viabilitas sel punca pulpa. Tujuan: Mengetahui efek penggunaan STS 5% setelah paparan NaOCl 1,5% dan NaOCl 5%-PBS-EDTA 17%-PBS dengan variasi paparan waktu terhadap viabilitas hDPSCs. Metode: Sel primer hDPSCs yang telah 80% confluent dan mencapai P3-P4 dilakukan starvation 24 jam, diberikan perlakuan berupa NaOCl-PBS-STS 5%-EDTA 17%-PBS, DMEM sebagai kontrol negatif dan NaOCl 1,5% serta 5% sebagai kontrol positif. Pengamatan viabilitas sel punca pulpa dengan uji flowcitometry MTT-assay. Hasil: Perbandingan antara kelompok NaOCl 5% terhadap kelompok NaOCl 5% - STS 5% 60’ berbeda tidak bermakna (p>0,5) namun nilai viabilitas kelompok NaOCl 5% - STS 5% 60’ lebih tinggi dibanding kelompok NaOCl 5%. Kesimpulan: Sodium thiosulfate sebagai agen antioksidan dan penetralisir NaOCl cukup efektif dalam mempertahankan viabilitas sel punca pulpa pada konsentrasi NaOCl 5% dengan paparan waktu 60’.

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Background: Endodontic irrigation with high concentrations of 5% Sodium Hypochlorite (NaOCl) has been reported to decrease pulp stem cell viability (hDPSCs) however NaOCl is the irrigant of choice for endodontic treatment. Another solution is needed to neutralize the effects of NaOCl, such as Sodium thiosulfate (STS) an antioxidant that has good antimicrobial but minimally effect on the viability hDPSCS. Objective: To determine the effect of 5% STS after exposure to 1.5% NaOCl and 5% NaOCl-PBS-EDTA 17%-PBS with variations in exposure time on the viability of hDPSCs. Method: hDPSCs that has been 80% confluent and reach P3-P4 done starvation for 24 hour,was given treatment of NaOCl-PBS-STS 5%-EDTA 17%-PBS, DMEM as a negative control and NaOCl 1.5% and 5% as a positive control. Observation of viability by MTT-flow cytometry assay. Results: The comparison between the 5% NaOCl group and the 5% NaOCl - 5% STS 60' group was not significantly different (p>0.5) but the viability value of the 5% NaOCl - 5% 60' NaOCl group is higher than 5% NaOCl group. Conclusion: Sodium thiosulfate as an antioxidant agent and NaOCl neutralizer is quite effective in maintaining the viability of pulp stem cells at 5% NaOCl concentration with an exposure time of 60'."