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"Penelitian ini bertujuan mengidentifikasi potensi fluktuasi suhu mata air panas sebagai prekursor gempabumi tektonik di Sesar Cimandiri dengan menggunakan teknologi Internet of Things (IoT). Latar belakang penelitian ini adalah tingginya aktivitas seismik di sekitar Sesar Cimandiri, yang disebabkan oleh pergerakan lempeng Eurasia dan Indo-Australia. Fluktuasi suhu pada mata air panas di daerah tersebut diasumsikan dapat menjadi indikator awal atau prekursor terjadinya gempabumi. Berdasarkan teori K. Mogi dan Jonathan R. Bedford, perubahan tekanan dan aktivitas seismik pada kerak bumi dapat menyebabkan peningkatan suhu pada mata air panas sebelum gempa terjadi. Penelitian ini dilakukan dengan metode pemantauan suhu mata air panas menggunakan IoT berbasis Arduino yang dilengkapi dengan sensor suhu DS18B20. Pengumpulan data suhu dilakukan pada dua lokasi mata air panas utama, yaitu Cisolok dan Cikundul, yang terletak di sekitar Sesar Cimandiri, dengan interval waktu perekaman setiap dua menit selama periode Mei hingga Oktober 2024. Data suhu mata air panas dihubungkan dengan data kejadian gempa tektonik yang terjadi dalam radius 50 km dari Sesar Cimandiri. Variabel utama yang dianalisis meliputi suhu mata air panas Cisolok dan Cikundul, jarak episentrum gempa, jenis batuan, dan struktur geologi yang dilalui gelombang seismik. Hasil penelitian menunjukkan adanya fluktuasi suhu pada mata air panas sebelum sebagian besar gempa yang terjadi. Delapan dari sepuluh peristiwa gempabumi menunjukkan peningkatan suhu yang signifikan pada mata air panas di Cisolok dan Cikundul. Analisis yang dilakukan menunjukkan bahwa jarak antara episentrum gempa dan lokasi mata air panas memengaruhi intensitas serta waktu fluktuasi suhu yang terjadi. Selain itu, jenis batuan yang dilalui oleh gelombang seismik juga turut mempengaruhi pergerakan panas dalam akuifer di bawah permukaan, yang pada akhirnya berdampak pada fluktuasi suhu mata air panas.

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This study aims to identify the potential of hot spring temperature fluctuations as precursors to tectonic earthquakes along the Cimandiri Fault, utilizing Internet of Things (IoT) technology. The background of this research is the high seismic activity around the Cimandiri Fault, driven by the movement of the Eurasian and Indo-Australian plates. Temperature fluctuations in the region's hot springs are hypothesized to serve as early indicators or precursors of earthquakes. Based on the theories of K. Mogi and Jonathan R. Bedford, changes in pressure and seismic activity in the Earth's crust can lead to increased temperatures in hot springs prior to earthquake events. The study employs a method of monitoring hot spring temperatures using Arduino-based IoT technology equipped with DS18B20 temperature sensors. Temperature data were collected from two major hot spring locations, Cisolok and Cikundul, situated near the Cimandiri Fault, with recording intervals every two minutes from May to October 2024. The temperature data from the hot springs were correlated with data on tectonic earthquakes occurring within a 50 km radius of the Cimandiri Fault.Key variables analyzed include the hot spring temperatures at Cisolok and Cikundul, the distance from the earthquake epicenter, the type of rock, and the geological structures through which seismic waves travel. The results revealed temperature fluctuations in the hot springs prior to the majority of the recorded earthquakes. Eight out of ten earthquake events showed significant temperature increases in the hot springs at Cisolok and Cikundul. Further analysis indicated that the distance between the earthquake epicenter and the hot spring locations influenced the intensity and timing of the observed temperature fluctuations. Additionally, the type of rock traversed by seismic waves impacted subsurface heat movement within the aquifer, ultimately affecting the temperature fluctuations in the hot springs."

"Telah dilakukan immobilisasi TiO2 dalam bentuk lapisan tipis pada permukaan kaca preparat. Teknik pelapisan menggunakan teknik proses sol-gel (PSG) dari prekursor titanium tetraisopropoksida yang dilarutkan dalam isopropanol pada konsentrasi 0,05 M dan 0,1 M. Lapisan tipis yang diperoleh dikarakterisasi dengan instrumen spektrofotometer UV-Vis, difraksi sinar-x, foto SEM, serta dilakukan uji aktivitas mendegradasi fenol sebagai model limbah organik dan uji adsorbsi. Hasil XRD menunjukkan bahwa kristal yang diperoleh anatase dan tidak terdeteksi adanya rutil. Dari difraktogram tersebut juga dapat diperkirakan ukuran kristal yang dihasilkan adalah sekitar 19 - 39 nm. Foto SEM menunjukkan permukaan yang cukup berpori, namun uji adsobsi menunjukkan peningkatan luas permukaan hanya 20%. Dari hasil uji aktivitas dapat diprediksi bahwa katalis dengan tebal 6,33 µm, dan kandungan TiO2 1,04 mg/cm2 akan memiliki aktivitas optimum.

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The Characterization of Thin Layer Titanium Dioxide from Titanium Tetraisopropoxide Precursor and the Examination of Its Activity as Photo CatalystImmobilization of TiO2 as thin layer on microscope slide glasses has been done. The slide was coated by sol-gel technique with titanium tetraisopropoxide as precursor diluted in isopropanol at the concentration of 0.05 M and 0.1 M. The thin films produced were characterized with W-Vis spectrophotometer, X-ray diffraction analyzer (XRD), SEM, and the activity as photo catalyst was examined by degrading phenol as an organic pollutant model, and also done adsorption examination.

The XRD results show that the crystal produced were in the anatase form and there are no rutile form detected. The results were also provide that the expectation size of the crystal was about 19 -- 37 nm. SEM results show moderate porosity of the thin layer surface but the adsorption examinations provide that the effective surface width increased in only 20 percent. From the result of activity examinations was been able to predict that thin layer catalyst at the thick of 6.33 µm, and TiO2 loading of 1.04 mg/cm2 has maximum activity."

"ABSTRAKGeopolimer sebagai filler dapat digunakan sebagai semen instan yang ramah lingkungan dalam proses reparasi jalan beton. Sampel prekursor sintetis geoplimer dihasilkan melalui metode melt-quench. Analisa melalui XRD dan uji kuat tekan dilakukan untuk mengetahui perbandingan amorfisitas antara prekursor metakaolin sintetis, prekursor abu terbang class F sintetis, prekursor metakaolin alami, dan prekursor abu terbang class F alami dalam lingkup pengaruhnyaterhadap reaktivitas geopolimer dalam medium alkali. Sampel dengan struktur prekursor dan struktur geopolimer yang lebih amorf memiliki reaktivitas dan kuat tekan yang lebih tinggi. Komposisi prekursor, sejarah perlakuan, kandungan pengotor, cooling rate, komposisi geopolimer memberi pengaruh signifikan pada struktur yang terbentuk.

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ABSTRACTGeopolymer as filler can be used in repairing the concrete road for itscharacteristic as environment friendly instant cement. Synthetic geopolymer precursor was made by melt-quench method. XRD and compressive strength test have been done in order to analyzing the amorphous comparative of synthetic metakaoline precursor, synthetic class F fly ash, natural metakaoline precursor, natural class F fly ash respectively corresponds to reactivity in alkaline medium. Precursor and geopolymer that have more amorphous structure indicate higher reactivity and compressive strength. Precursor composition, treatment history, modifier content, cooling rate, geopolymer composition give significant effect on the structure produced."

"Keberadaan limbah antibiotik di berbagai sumber air menimbulkan bahaya lingkungan yang besar, karena limbah tersebut tetap utuh dan tahan terhadap dekomposisi, sehingga menimbulkan tantangan bagi ekosistem. Penelitian ini bertujuan untuk mengatasi masalah ini dengan berfokus pada penetapan muatan optimal g-C3N4 dalam komposit g-C3N4-TiO2. g-C3N4 diproduksi dari beberapa prekursor seperti melamin, disiandiamida, dan urea. Tujuan utama komposit baru ini adalah berfungsi sebagai fotokatalis yang sangat efisien untuk degradasi ciprofloksasin di bawah pengaruh pencahayaan yang berbeda. Fotokatalis yang dihasilkan akan dikarakterisasi secara menyeluruh menggunakan berbagai teknik termasuk XRD, UV-Vis DRS, SEM, dan FTIR. Degradasi ciprofloksasin akan dipantau secara cermat dengan mengumpulkan sampel larutan secara berkala dan melakukan analisis menyeluruh menggunakan spektrofotometri UV-Vis. Uji degradasi akan dilakukan menggunakan reaktor foto yang dibangun secara khusus, yang akan memanfaatkan iradiasi internal dari lampu UV 20 W dan lampu tampak 23 W. Metode yang digunakan untuk percobaan ini adalah kalsinasi untuk sintesis g-C3N4, dan impregnasi untuk pencampuran komposit. Setelah melakukan percobaan, jenis komposit yang paling efektif ditemukan yaitu (5)U-CN- TiO2, dengan laju degradasi 82%, yaitu 29% lebih besar dari TiO2 murni di bawah Iradiasi sinar UV dan laju degradasi 31%, yaitu 15% lebih besar dari TiO2 murni di bawah cahaya tampak. Oleh karena itu, penambahan g-C3N4 ke TiO2 dapat meningkatkan laju degradasi fotokatalitik.

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The presence of antibiotic waste in different water sources poses a substantial environmental hazard, as it remains intact and resistant to decomposition, hence posing a challenge to the ecosystem. This study aims to address this problem by focusing on establishing the optimal loading of g-C3N4 within g-C3N4-TiO2 composite. The g-C3N4 is produced from several precursors such as melamine, dicyandiamide, and urea. The primary objective of these new composites is to function as exceptionally efficient photocatalysts for the degradation of ciprofloxacin under the influence of different lighting. The generated photocatalysts will be thoroughly characterized using a range of techniques including XRD, UV-Vis DRS, SEM, and FTIR. The degradation of ciprofloxacin will be carefully monitored by periodically collecting samples of the solution and doing thorough analysis using UV-Vis spectrophotometry. The degradation trials will be carried out using a specifically built photo reactor, which will utilize internal irradiation from a 20 W UV light and 23 W visible light. The methods used for this experiment were calcination for the synthesis of g-C3N4, and impregnation for mixing the composite. After conducting the experiment, the most effective type of composite was discovered to be (5)U-CN-TiO2, with a degradation rate of 82%, which is 29% greater than pure TiO2 under UV light Irradiation and 31% degradation rate, which is 15% greater than purê TiO2 under visible light. Therefore, the addition of g-C3N4 to TiO2 can increase the photocatalytic degradation rate."

"Transparent conductive oxide (TCO) glass is one of most important components in dye-sensitized solar cell (DSSC) device. In addition to its high electrical conductivity, transparency is another important requirement that must be achieved in fabricating TCO. One TCO film is fluorine-doped tin oxide (FTO), which can be considered as the most promising substitution for indium-doped tin oxide (ITO), since the latter is very expensive. However, the fabrication techniques for TCO film need to be carefully selected; the synthesis parameters must be properly optimized to provide the desired properties. In this work, FTO glass has been fabricated by the ultrasonic spray pyrolisis technique with different precursors, i.e. tin (II) chloride dihydrate (SnCl2.2H2O) and anhydrous tin (IV) chloride (SnCl4), as well as different solvents, i.e. ethanol and methanol. For both conditions, ammonium fluoride (NH4F) was used as the doping compound. The resulting thin films were characterized by use of a scanning electron microscope (SEM), x-ray diffraction (XRD), ultraviolet-visible (UV-Vis) spectroscopy and a four-point probe test. The results of the investigation show that the highest transmittance of 88.3% and the lowest electrical resistivity of 8.44×10-5 ?.cm were obtained with the FTO glass processed with 20 minutes of spray pyrolysis deposition and 300oC substrate heating, using SnCl4 as the precursor and methanol as the solvent. It can be concluded that TCO fabrication with tin chloride precursors and ammonium fluoride doping using ultrasonic spray pyrolisis can be considered as a simple and low cost method, as well as a breakthrough in manufacturing conductive and transparent glass."

"The growth and crystallization processes of the Cu2ZnSnS4 (CZTS) phase typically rely on high-temperature sulfurization, which involves a harmful chalcogen-containing atmosphere. Together with the use of high-toxicity solvents, these processes could hinder the widespread adoption of this technology in the mass production of CZTS semiconductors for solar cell application. Thus, we studied the formation of CZTS films from ethanol-based precursors without the sulfurization step, fully employing the non-toxic solvent and avoiding the environmentally harmful sulfur-containing atmosphere. The certain addition of 2-mercaptopropionic acid led to the formation of a clear and stable sulfur-containing precursor. The precursors were successfully deposited onto soda lime glass by employing spin coater. CZTS crystallinity in the identified XRD patterns was vanishingly small in the case of eliminating the sulfurization process. Moreover, the carbon concentration and grain size of the resulting films were controlled by changing the time period of drying treatment during film fabrication. A drying time of 120 minutes, which demonstrated a CZTS grain size of ± 1 µm with a direct optical energy gap around 1.4 eV, was confirmed as the ideal condition. These results may provide a useful route toward environment-friendly strategies for the production of a CZTS semiconductor that is compatible with the absorber application in thin-film solar cells."

"MoS2 nanosheet-microsphere telah berhasil disintesis melalui metode hidrotermal dengan prekursor amonium heptamolibdat dan tiourea yang konsentrasinya campuran bervariasi 0,25 M, 0,5 M, 1,0 M dan 1,5 M. Struktur kristal, morfologi, ukuran partikel dan koefisien gesekan dan pembentukan tribofilm diamati sebagai pengaruh dari konsentrasi prekursor. Pola difraksi sinar-X menunjukkan struktur kristal heksagonal 2H-MoS2 dengan perbedaan kristalinitas medan (002) dan tidak ditemukan fase lain. Pengukuran Spektrometer Raman menunjukkan pergeseran frekuensi E1 2g dan A1g bersama dengan perubahan konsentrasi prekursor di mana MoS2 adalah dengankonsentrasi prekursor dari frekuensi 0,25 M mendekati frekuensi massal MoS2 menunjukkan semakin banyak lapisan dan kristalinitas yang lebih baik. Pengamatan dengan Scanning Electron Microscope (SEM) yang menunjukkan morfologi partikel lembar nano dengan puluhan ketebalan nanometer berkumpul untuk membentuk microsphere dengan diameter 1-3 μm. Pengukuran koefisien gesek dan pembentukan lapisan film menunjukkan efek kristalinitas partikel pada koefisien gesekan dan pembentukan lapisan film di mana partikel dengan kristalinitas lebih rendah menghasilkan nilai koefisien gesekan yang lebih kecil dan pembentukan lapisan film lebih cepat. Menguji koefisien gesekan dengan Rig Reciprocating Frekuensi Tinggi (HFRR) juga menunjukkan penambahan 2% berat dan 3% berat MoS2-1,5M mengurangi koefisien gesekan pelumasan Yubase 8 sebesar 30% dan 37,5%

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MoS2 nanosheet microsphere has been successfully synthesized through the hydrothermal method with precursors of ammonium heptamolybdate and thiourea whose concentrations the mixture is varied 0.25 M, 0.5 M, 1.0 M and 1.5 M. Crystal structure, morphology, particle size and friction coefficient and tribofilm formation were observed as influences from precursor concentration. X-ray diffraction pattern shows the crystal structure hexagonal 2H-MoS2 with a difference in field crystallinity (002) and not found another phase. Raman Spectrometer measurements show E1 frequency shifts 2g and A1g along with changes in precursor concentration where MoS2 is with the precursor concentration of 0.25 M frequency approaches the bulk MoS2 frequency indicates more and more layers and better crystallinity. Observation with Scanning Electron Microscope (SEM) showing particle morphology nanosheets with tens of nanometer thickness gathered to form microsphere with a diameter of 1-3 μm. Measurement of coefficient of friction and formation film layer shows the effect of particle crystallinity on the coefficient of friction and the formation of a film layer where particles with lower crystallinity resulting in smaller friction coefficient values ​​and film layer formation faster. Testing the coefficient of friction with the High Frequency Reciprocating Rig (HFRR) also shows the addition of 2 wt% and 3 wt% MoS2-1.5 M can decreases the coefficient of lubrication friction Yubase 8 by 30% and 37.5%."

"Sintesis semikonduktor Cu2ZnSnS4 (CZTS) sebagai absorber sel surya lapis tipis telah dilakukan dengan metode ekonomis dan ramah terhadap lingkungan dengan pelarut etanol. Prekursor CZTS diperoleh dari melarutkan garam logam berupa CuCl2, ZnCl2, dan SnCl4 dengan etanol, kemudian larutan tersebut ditambahkan 2-mercaptopropionic acid sebagai stabilizer. Penambahan thiourea dengan konsentrasi 4,4M, 5,4M, dan 6,4M dilakukan setelah memasukkan 2-mercaptopropionic acid yang dilanjutkan dengan deposisi larutan di atas kaca menggunakan metode spin coating. Sifat optik, morfologi, dan komposisi semikonduktor CZTS dibahas secara detil. Dengan konsentrasi sulfur yang bertambah akan memberikan hasil deposisi lapisan yang mengalami penurunan sifat optik. Nilai energi celah pita yang dihasilkan sebesar 1,4eV, 1,5eV, dan 1,52eV untuk konsentrasi 4,4M, 5,4M, dan 6,4M secara berurutan.

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Synthesis Cu2ZnSnS4 (CZTS) thin film absorber layer semiconductor has been made by cost-effective and environmentally friendly method using ethanol solvent. The precursor of CZTS was obtained from dissolving metal salts of CuCl2, ZnCl2, and SnCl4 with ethanol, then the solution was added 2-mercaptopropionic acid as stabilizer. The addition of thiourea with concentration 4,4M, 5,4M, and 6,4M was performed after adding 2-mercaptopropionic acid followed by deposition of the solution on the glass using spin coating method. The characteristic of optic, morphology, and composition of CZTS semiconductor are to be described in-depth. With increasing the sulfur concentration will decreased optical properties of deposition coating result. The constants of band gap that are produced are 1,4eV, 1,5eV, and 1,52eV for 4,4M, 5,4M, and 6,4M respectively."

"The growth and crystallization processes of the Cu2ZnSnS4 (CZTS) phase typically rely on high-temperature sulfurization, which involves a harmful chalcogen-containing atmosphere. Together with the use of high-toxicity solvents, these processes could hinder the widespread adoption of this technology in the mass production of CZTS semiconductors for solar cell application. Thus, we studied the formation of CZTS films from ethanol-based precursors without the sulfurization step, fully employing the non-toxic solvent and avoiding the environmentally harmful sulfur-containing atmosphere. The certain addition of 2-mercaptopropionic acid led to the formation of a clear and stable sulfur-containing precursor. The precursors were successfully deposited onto soda lime glass by employing spin coater. CZTS crystallinity in the identified XRD patterns was vanishingly small in the case of eliminating the sulfurization process. Moreover, the carbon concentration and grain size of the resulting films were controlled by changing the time period of drying treatment during film fabrication. A drying time of 120 minutes, which demonstrated a CZTS grain size of ± 1 µm with a direct optical energy gap around 1.4 eV, was confirmed as the ideal condition. These results may provide a useful route toward environment-friendly strategies for the production of a CZTS semiconductor that is compatible with the absorber application in thin-film solar cells."

"Latar Belakang: Remineralisasi pada dentin affected dapat terjadi secara guided tissue remineralization (GTR). Remineralisasi ini terjadi pada matriks intrafibrilar kolagen dentin karena peran protein non kolagen yaitu Dentin Matriks Protein 1 (DMP1) yang dapat rusak saat proses demineralisasi. Dibutuhkan material analog pengganti DMP1 untuk proses remineralisasi, salah satunya adalah asam poliaspartik dalam proses Polymer-Induced Liquid Precursor (PILP). Tujuan: Menganalisis remineralisasi yang terjadi pada demineralized dentin setelah diinduksi oleh asam poliaspartik dalam proses PILP. Metode: Sampel berupa dentin blok direndam pada larutan demineralisasi lalu dibagi menjadi empat kelompok, yaitu kelompok demineralized dentin tanpa perendaman larutan asam poliaspartik dan kelompok dengan perendaman larutan asam poliaspastik selama 3, 7, dan 14 hari. Sampel di evaluasi dengan uji SEM dan EDX. Hasil: Terdapat perbedaan signifikan antara kelompok demineralized dentin dengan kelompok remineralisasi asam poliaspartik pada hari ke 3, 7, dan 14. Remineralisasi yang terjadi berupa deposit ion kalsium dan fosfat. Kesimpulan: Asam poliaspartik dalam proses PILP memiliki potensi untuk meremineralisasi demineralized dentin.

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Background: Remineralization on affected dentin can be occurred by guided tissue remineralization (GTR) method. The remineralization process took place in intrafibilar matrix dentin collagen which regulated by a non collagenous protein, Dentin Matrix Protein (DMP 1) which can be destroyed during demineralization process. Remineralization process requires non collagenous protein analog material, one in particular is poliaspartic acid in Polymer-Induced Liquid Precursor (PILP) process. Objective: To analyze remineralization process that occured on demineralized dentin after application polyaspartic acid in PILP process. Method: Dentin block sample was soaked in demineralized solution. The sample then divided into four groups which are demineralized dentin without application of poliasparticacid solution, and demineralized dentin soaked in polyaspartic acid solution in the period of 3 ,7 and 14 days. The samples were evaluated by using SEM and EDX. Result: A statistically significant result between demineralized dentin group and remineralization with poliaspartic acid group within 3, 7, 14 days. Remineralization occurred by calcium and phosphate ions deposition. Conclusion: Polyaspartic acid in PILP process has the capability of remineralizing demineralized dentin."