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"This investigation presents the synthesis procedure and the results of an investigation of the crystallite growth of TiO2 and the formation of Si–O–Ti bonds in novel silica xerogel (SiO2) glass ceramic produced from an amorphous SX derived from sago waste ash. The composition had been prepared by adding various amounts of TiO2, from 20 wt% to 80 wt%, into the amorphous SiO2, and then a series of samples were sintered at 1200°C for 2 hours. The influence of the content of TiO2 and the sintering temperature on the properties of TiO2, namely crystallite size and formation of Si–O–Ti bonds, has been studied in detail. The properties of the produced ceramics have been characterized on the basis of the experimental data obtained using X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. It has been found that an addition of SiO2 confers an appreciable effect on the quantity of Si–O–Ti bonds. The interpretation of the XRD pattern allows one to explain the increase in the crystallite size of rutile TiO2 by a decreased quantity of Si–O–Ti bonds."

"Telah dilakukan penelitian untuk membuat paduan Sn-Cu-Zn dengan menggunakan material solder 99.3% Sn - 0.7% Cu (wt%) dan plat Zn. Pembuatan material menggunakan metode peleburan dengan lima buah sampel dengan variasi komposisi Zn. Karakterisasi XRD digunakan untuk melihat sifat struktural, fasa yang terbentuk, ukuran kristal serta regangan mikro. Metode perhitungan ukuran kristal dan regangan mikro menggunakan metode Scherrer dan metode Williamsons-Hall. Dari hasil penelitian didapatkan bahwa besar parameter kisi akan berubah saat besar konsentrasi Zn ditambahkan juga, walaupun besar perubahan tersebut tidak signifikan. Ukuran kristal terbesar didapatkan pada 12.9 wt% Zn, saat besar konsentrasi Zn ditambahkan maka ukuran kristal serta regangan mikro akan menurun. Pada paduan Sn-Cu-Zn ini hanya ditemukan 3 buah fasa yaitu fasa Sn (Timah), fasa Cu (Tembaga) dan fasa Zn (Seng).

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Research on creating Sn-Cu-Zn alloys consisting solder material 99.3% Sn - 0.7% Cu (wt%) and Zn plate has been done. The alloy were manufactured using fusion method with five various Zn composition. XRD characterization was used to observe the structural properties, type of phase, crystallite size and microstrain. Scherrer and Williamson-Hall method was used to calculate crystallite size and microstrain. The result shown that lattice parameter changed when Zn concentration changed, with no significant variation of change. The largest crystallite size were found with 12.9 wt% Zn, and when the Zn composition was increased the crystallite size and microstrain will decrease. Only 3 phase were found in Sn-Cu-Zn alloys, the phases is Sn (Stannum), Cu (Cuprum) and Zn (Zinc)."

"ABSTRAKPolianilin telah disintesis melalui polimerisasi oksidatif kimia dengan Ammonium Peroksidisulfat APS sebagai inisiator dalam berbagai konsentrasi 50 g/L, 100 g/L dan 200 g/L . Polimerisasi anilin berjalan dengan ditandai adanya kenaikan temperatur karena reaksi yang terjadi dalam larutan mencapai temperatur tertinggi sebesar 42 C pada larutan dengan konsentrasi APS 200 g/l. Hasil dari reaksi polimerisasi oksidatif berupa basa emeraldin PANi-EB . Struktur PANi dikonfirmasi dengan FTIR ditandai dengan adanya vibrasi stretching pada cincin benzenoid dan quinoid pada bilangan gelombang 1400-1500 cm-1. Sifat konduktif PANi diperoleh melalui pemberian protonasi menggunakan asam kuat yaitu HCl dan HClO4. Nilai konduktivitas PANi-EB mengalami peningkatan 102 kali setelah doping menggunakan HCl dan 106 kali pasca doping HClO4. Semua PANi hasil sintesis memiliki kemampuan penyerapan gelombang elektromagnetik pada rentang frekuensi 10 GHz-15 GHz. Semakin tinggi nilai resistivitas PANi yaitu makin rendah nilai konduktivitas, semakin tinggi juga nilai reflection loss RL . Nilai RL tertinggi sekitar -18 dB pada frekuensi 12,5 GHz dan 14,3 GHz diperoleh dari PANi-EB hasil polimerasi dengan konsentrasi APS sebesar 200 g/l.

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ABSTRAKPolianiline has been synthesized by chemical oxidative polymerization using Ammonium Polyaniline has been synthesized through chemical oxidative polymerization with Ammonium Peroxidisulfate APS as an initiator in various concentrations 50 g l, 100 g l and 200 g l . The polymerization reactions of aniline are characterized by an increase in temperature due to the reaction occurring in the solution, reaching the highest temperature of 42 C in a solution with APS concentration of 200 g l. Result of oxidative polymerization reaction is the emeraldine base polyaniline or PANi EB. The PANi formation was confirmed by FTIR which characterized by stretching vibrations in benzenoid and quinoid rings at wave numbers 1400 1500 cm 1 respectively. The conductive property of PANi was obtained through doping by a protonation using strong acids HCl and HClO4. It was found that conductivity value PANi EB increased 102 times after doping with HCl and 106 times after doping with HClO4. Moreover, all synthesized PANi has the ability to absorb electromagnetic waves in the frequency range 10 GHz 15 GHz. The higher the resistivity value of PANi that is the lower the conductivity value, the higher the reflection loss RL . The highest RL values of about 18 dB at 12.5 GHz and 14.3 GHz frequencies were obtained from PANi EB polymeration results with APS concentrations of 200 g l."

"The purpose of this research was to study the synthesis of TiO2 nanotubes on Ti-10Ta-10Nb thin film and the effect of applied potential on the tube size, length and morphology. The Ti-10Ta-10Nb thin film was deposited by dc magnetron sputtering on the CP Ti substrate. The anodization of this Ti-10Ta-10Nb thin film was performed in the solution containing 1M H3PO4 + 1.5wt.% HF at the potential readings of 4, 6, 8 and 10 V for 10 minutes. The results showed that there was a slight increase in the tube diameter from approximately 25 nm at 4 V to 50 nm at 8 V. The length of nanotube varied from 700-900 nm. Interestingly, at the potential of 10 V, the nanotube diameters were damaged with slight decreases in nanotube lengths (500 nm)."

"Dalam penelitian ini telah dilakukan sintesis material katalis terimmobilisasi mikropartikel dan nanopartikel TiO2 dan evaluasi aktivitas fotokatalitiknya pada dekolorisasi larutan zat warna azo Acid Red 4 (AR4). Mikropartikel TiO2 diimmobilisasikan pada pelat akrilik, sedangkan nanopartikel TiO2 terimmobilisasi pada pelat gelas. Nanopartikel TiO2 dilekatkan pada lapisan pendukung nanofiber untuk meningkatkan performa fotokatalitik, membentuk komposit nanofiber-nanopartikel di atas pelat gelas. Pada beban katalis 2,0 g/l, performa fotokatalitik lapisan katalis terimmobilisasi (k'=0,013 menit -1) lebih baik dibandingkan katalis tersuspensi (k'=0,008 menit -1). Efisiensi dekolorisasi fotokatalitik katalis terimmobilisasi TiO2 berukuran nanopartikel mencapai 82,3% dalam waktu irradiasi 2 jam, lebih tinggi dibandingkan katalis berukur an mikropartikel (77,8%). Teknik komposit nanofiber-nanopartikel TiO2 memperlihatkan peningkatan kinetika fotokatalitik (k'= 0,018 menit -1) dibandingkan lapisan katalis tunggal nanopartikel (k'= 0,015 menit -1). Katalis terimmobilisasi TiO2 tetap efektif dalam penggunaan berulang meski ditemukan sedikit penurunan efisiensi pengolahan.

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This research studied the synthesis of immobilized TiO2 microparticle and nanoparticle catalyst materials and evaluated its photocatalytic activity on the decolorization of Acid Red 4 (AR4) azo dye solution. TiO2 microparticles were immobilized on an acrylic plate, while TiO2 nanoparticles were immobilised on a glass plate. TiO2 nanoparticles were embedded in a nanofiber support layer to enhance photocatalytic performance, forming a nanofiber-nanoparticle composite on the glass plate. In the catalyst load 2.0 g/l, the performance of the photocatalytic layer of immobilized catalyst (k '= 0.013 min-1) is better than that of the suspended catalyst (k'= 0.008 min-1). Photocatalytic decolorization efficiency of TiO2 immobilized catalysts of nanoparticle sized reached 82.3% in irradiation time of 2 hours, which is higher than microparticle sized catalysts (77.8%). The technique of TiO2 nanofiber-nanoparticle composite showed improved photocatalytic kinetics (k'= 0.018 min-1) compared to a single layer of nanoparticle catalyst (k'= 0.015 min-1). Immobilized TiO2 catalysts remain effective with repeated use despite a slight decrease inprocessing efficiency."

"Pembukaan konstitusi proklamasi, undang-undang dasar negara republik Indonesia tahun 1945 ( UUD NRI 1945) merupakan kristalisasi dari cita negara dan cita hukum negara republik Indonesia . Dalam pembukaan konstitusi tersebut terkandung alasan, tujuan dan misi negara berlandaskan nilai dasar pancasila.embukaan dianggap bertentangan dengan semangat pembukaan dianggap bertentangan dengan konstitusi."

"Polylactid acid (PLA) adalah plastik berbasis alam yang memiliki potensial yang besar untuk menggantikan plastik berbasis minyak bumi karena tingginya modulus young dan kuat tariknya. Akan tetapi PLA memiliki kekurangan yaitu ketangguhan dan kecepatan kristalisasinya yang rendah yang membatasi aplikasinya.Pada penelitian ini, PLA diperkuat oleh serat bambu dengan perlakuan berbeda seperti perlakuan alkali (NaOH) dan perlakuan pemutihan (NaClO) yang bertujuan untuk meningkatkan kristalinitas PLA. Kandungan serat bambu dalam komposit adalah 5, 10 dan 20 %. Kandungan kimia dan kristalintas serat diselidiki dengan menggunakan FTIR (Fourier Transform Infra Red ) dan XRD (X ray Diffraction). Terbukti bahwa terjadi peningkatan kristalinitas seiring dengan penurunan lignin dan hemiselulosa. Kristalinitas serat bambu yang tidak diberi perlakuan adalah 56,5 %, sedangkan dengan perlakuan alkali adalah 64 % dan dengan perlakuan pemutihan adalah 66,6 %. Untuk mengetahui efek kristalinitas terhadap PLA dilakukan uji DSC (differensial Scanning Calorimetri) dan XRD pada masing – masing sampel komposit. Hasil XRD menunjukkan adanya interaksi antara serat dan PLA serta menunjukkan adanya peningkatan kristalinitas. Peningkatan kristalinitas terjadi ketika penambahan kandungan 10 % dan 20 % serat tetapi tidak pada kandungan serat 5 %. Tanpa memperhatikan komposit PLA – serat bambu kandungan serat 5 %, kristalinitas tertinggi terjadi pada PLA – serat bambu hasil perlakuan pemutihan. Sedangkan hasil DSC menujukkan kecenderungan peningkatan kristalinitas seiring dengan bertambahnya kandungan serat.

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Polylactid acid (PLA) is a bio-based palstic that has a great potential to replace petroleum-based plastic due to its high Young's modulus and tensile strength. However, the drawbacks of PLA are low toughness and slow crystallization speed limited it's application. In this study, PLA reinforced by bamboo fibers with different treatments such as alkali treated (NaOH) and bleaching treated (NaClO) in order to improve the crystallinity of PLA. The concentration of bamboo fiber in the composite were 5, 10 and 20 wt%. The chemical content and cystallinity of fiber was investigated by FTIR (Fourier Transform Infra Red ) and XRD (X ray Diffraction). It was proved that the crystallinty of fiber was increased with decreasing of lignin and hemicellulose. Bamboo fibers without treatment has 56,5 % cystallinity, while alkali treatment 64 % crystallinity and fiber bleaching treatment has 66,6 % crystalllinity. To determine the crystallinity effect of treated fiber on PLA composite, DSC (Differential Scanning Calorimetry) and XRD test was conducted on each composite sample. XRD result showed the interaction between fibers and PLA and an increasing of crystallinity with increasing of fiber content. The increasing of crystallinity happened on 10 % and 20 % fiber content but not in composite with 5 % fiber content. By obeying 5 % fiber content on PLA, the best cystallinty was PLA - bleached bamboo fiber composite. The DSC data showed that increasing of fiber content resulted in increasing crystallization rate of PLA."

"Latar Belakang: Saliva mengandung protein yang berfungsi sebagai pertahanan rongga mulut terhadap S.sanguinis dan C.albicans, keduanya diketahui memiliki interaksi sinergis.Tujuan: menganalisis efek protein saliva spesifik dan non-spesifik C.albicans dari kelompok usia anak, dewasa, dan lansia sebagai pelikel dalam pembentukan biofilm S.sanguinis in vitro.Metode: Uji Biofilm yang diinkubasi 6 dan 18 jam.Hasil: Protein spesifik C.albicans menurunkan pembentukan biofilm S.sanguinis pada inkubasi 18 jam (p≤0.05). Protein saliva non-spesifik C.albicans menurunkan pembentukan biofilm pada inkubasi 6 jam dan sebaliknya pada inkubasi 18 jam (p≤0.05).Kesimpulan: Protein spesifik C.albicans menurunkan pembentukan biofilm S.sanguinis, sedangkan protein non-spesifik C.albicans meningkatkan pembentukan biofilm S.sanguinis

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Background: Saliva contains protein as defense against S.sanguinis and C.albicans, which both known to synergist.

Objective: to analyze the effect of specific and non-specific salivary proteins to C.albicans from children, adult, and elderly as a pellicle on S.sanguinis biofilm formation in vitro.

Methods: Biofilm Assay incubated in 6 and 18 hours.

Results: Specific salivary protein to C.albicans decreased S.sanguinis biofilm formation at 18 hours incubation (p≤0.05). Non-specific protein decreased the biofilm formation at 6 hours incubation, contrary to the 18 hours incubation (p≤0.05).

Conclusion: Specific salivary protein to C.albicans decreased S.sanguinis biofilm formation, contrary to non-specific salivary protein to C.albicans."