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Abstrak :
The need of electronic has influenced the world of pharmaceutical nowadays.A hardness tester tester is one of the measurement devices that need digitation.....

Abstrak :
Kekerasan nanokomposit nc-TiN/a-Si3N4 yang diperoleh dengan dengan dua metode pengukuran yaitu pengukuran kedalaman indentor dan pengukuran luas bekas indentasi yang diperbesar dengan SEM (Scanning Electron Microscope) memberikan hasil yang sama. Nilai kekerasan yang diperoleh tidak dipengaruhi oleh biaksial dan residual kompresif stress. Pengukuran biaksial stress pada substrat menghasilkan nilai yang sangat kecil dan perlakuan termal menunjukkan kekerasan yang tetap dengan ukuran butir yang tetap. Kekerasan yang diperoleh diyakini sebagai nilai kekerasan yang intrinsik yang tergantung pada sifat mikrostrukturnya.

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Hardness of nc-TiN/a-Si3N4 nanocomposites which was determined by using two methods of measurements i. e. depth sensing method and remaining plastic indentation area that were magnified by using SEM (Scanning Electron Microscope) lie in the good agreement. The hardness value is not influenced by the biaxial and residual compressive stress. The measurement of the biaxial stress on the substrate shows a very small value of biaxial stress as well as the constant hardness and crystallite size against annealing temperature. Therefore, the reported hardness value here is the intrinsic value that depend on its microstructure properties.

Abstrak :
Insulasi panas merupakan material yang penting dalam industri untuk menunjang efisiensi suatu proses sistem. Pada penelitian ini dilakukan pembuatan komposit dengan menggunakan epoksi Interzinc®52 sebagai matriks dan material zirkonia sebagai penguat. Proses pembuatan komposit dengan menggunakan metode pengaduk mekanis dengan kondisi waktu pengadukan 5 menit dan 15 menit. Material substrat yang digunakan adalah baja karbon ASTM A36 dengan ukuran 50 mm x 50 mm x 5 mm. Persen berat (wt%) untuk material zirkonia digunakan dengan Persen 5% (wt%), 10% (wt%) dan 15% (wt%) pada 50 ml epoksi, ketebalan lapisan insulasi 1 mm, 3 mm dan 5 mm. Pengujian dilakukan untuk mengetahui sifat termal dan sifat mekanis dari komposit yang terbentuk terdiri dari X-ray diffraction analysis, scanning electron microscopy, heat loss, thermogravimetric analysis, hardness shore D. Hasil pengujian menunjukkan bahwa penambahan kadar ZrO2 ke dalam epoksi dan kenaikan ketebalan lapisan dapat menghasilkan lapisan insulasi panas dengan stabilitas termal yang lebih baik dan menurunkan PRH (percentage of residual heat). Selain itu nilai kekerasan permukaan naik seiring bertambahnya ZrO2 di dalam epoksi, hal ini disebabkan adanya kenaikan kerapatan dalam struktur mikro. Sementara itu, semakin lama waktu pengadukan meningkatkan nilai kekerasan dan kemampuan lapisan komposit dalam menahan panas yang hilang ke permukaan. Dari penelitian ini di peroleh PRH terendah 64% dan nilai kekerasan tertinggi 36 HD pada sampel epoksi dengan campuran 15% ZrO2 pada ketebalan 5 mm setelah pengadukan selama 15 menit. ......Nowadays, Heat insulation is an important material in industry to support the efficiency of a system process. In this study, composites were made using epoxy Interzinc®52 as matrix and zirkonia material as reinforcement. The process of making composites using the mechanical stirring method with a stirring time of 5 minutes and 15 minutes. The substrate material used is ASTM A36 carbon steel with a size of 50 mm x 50 mm x 5 mm. Weight percentage (wt%) for zirkonia material used with percentages of 5% (wt%), 10% (wt%) and 15% (wt%) in 50 ml Epoxy, insulation layer thickness 1 mm, 3 mm and 5 mm. Tests were carried out to determine the thermal and mechanical properties of the composites, consisting of X-ray diffraction analysis, scanning electron microscopy, heat loss, thermogravimetric analysis, hardness shore D. The test results show that the addition of ZrO2 content into the epoxy and the increase in layer thickness can produce a heat insulation layer with better thermal stability and reduce PRH (percentage of residual heat). In addition, the surface hardness value increases with the addition of ZrO2 in the Epoxy, this is due to an increase in density in the microstructure. Meanwhile, the longer stirring time increases the hardness value and the ability of the composite layer to withstand heat loss to the surface. From this study, the lowest PRH value was 64% and the highest hardness value was 36 HD on the Epoxy sample with a mixture of 15% ZrO2 at a thickness of 5 mm after stirring for 15 minutes.

Abstrak :
Paduan aluminium 2024-T3 biasa digunakan dalam industri penerbangan seperti komponen pada pesawat terbang. Material ini digunakan karena sifatnya yang ringan dan cenderung tahan korosi jika dibandingkan dengan material selain aluminium, namun jika dibandingkan dengan paduan aluminium seri lainnya, paduan aluminium 2xxx cenderung memiliki ketahanan korosi yang rendah. Untuk memperbaiki sifat ini, maka dilakukan proses anodisasi dengan larutan elektrolit asam oksalat 0,5 M selama 30 menit. Proses anodisasi dilakukan pada temperatur 0, 10, dan 20°C serta rapat arus 15, 20, dan 25 mA/cm2. Penelitian bertujuan untuk mengetahui pengaruh dari kedua variabel tersebut terhadap kekerasan mikro dan laju korosi tiap sampel. Didapat hasil bahwa nilai kekerasan mikro paling tinggi pada permukaan sampel didapat pada sampel 0°C - 20 mA/cm2 dengan nilai kekerasan sebesar 543 HV. Sedangkan ketahanan korosi paling baik diperoleh pada sampel 20°C - 20 mA/cm2 dengan laju korosi sebesar 0,00004 mm/year. ...... Aluminum alloy 2024-T3 is commonly used in the aviation industry as components of aircrafts. This material is used because of its light weight and good corrosion resistant when compared to material other than aluminum, but when compared to other series of aluminum alloy, aluminum alloy 2xxx tend to have low corrosion resistance. To improve this property, then carried out the anodizing process with 0,5 M oxalic acid for 30 minutes. Anodizing was carried out at temperatures of 0, 10, and 20°C also at current densities of 15, 20, and 25 mA/cm2. The research aim is to know the influence of both these variables against the corrosion rate and micro-hardness of each samples. The result shows that the highest micro-hardness on the surface of samples is obtained at 0°C and 20 mA/cm2 with a value of 543 HV. While the most excellent corrosion resistance is obtained at 20°C and 20 mA/cm2 with the rate of corrosion of 0,00004 mm/year.

Abstrak :
Latar Belakang: LCU-LED prototip metode PWM iradiansi 900 dan 1.000 mW/cm2 telah dibuat untuk mengurangi panas akibat polimerisasi dengan waktu penyinaran 10 detik. Tujuan: Menganalisis pengaruh iradiansi terhadap kekerasan permukaan komposit resin nano. Metode: Sampel disinar dengan LCU-LED prototip iradiansi 900 dan 1.000 mW/cm2 serta LCU-LED pembanding iradiansi 900 mW/cm2. Kekerasan permukaan diuji dengan sistem Knoop. Data dianalisis dengan One-way ANOVA dan Post-HocTest. Hasil: Kekerasan permukaan antar kelompok berbeda signifikan kecuali antara penyinaran LCU-LED prototip iradiansi 900 mW/cm2 dan LCU-LED pembanding iradiansi 900 mW/cm2. Kesimpulan: Penyinaran iradiansi 900 mW/cm2 dari LCU-LED prototip dan LCU-LED pembanding menunjukan kekerasan permukaan yang sama.

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Introduction: Prototype LCU-LED using PWM with irradiance 900 and 1,000mW/cm2 has constructed that can reduce temperature for polymerizing in ten seconds. Objectives: To analyze influence of irradiance to the hardness of nano resin composites. Methods: Samples were polymerized using the prototype with irradiance of 900 and 1,000mW/cm2 or the off-the-shelf LCU-LED (900mW/cm2) as comparison. Hardness was measured using Knoop system. Statistical analysis was conducted by One-Way ANOVA and post-hoctest. Results: There’s significant differences among the groups except those between prototype and comparison with irradiance of 900mW/cm2. Conclusions: Hardness from prototype is equal to those from comparison with irradiance of 900mW/cm2

Abstrak :
Electrically plating or electroplating is one method used to beautify looks fine and also to improve the mechanical properties of the metal. The teksperiment is performed by preparing specimens have been measured with different variations in time for electroplating with a current of 10 amperes at 12 Volts. The results show that the corrosion test specimen electroplating results with the arrest ofO 1889847379 mpy 40 minutes, 30 minutes ofO. 1771731918mpy, 20 minutes by 0.1417385534 mpy, and without coating 0.93298832 mpy. Judging from the results on each specimen corrossion the safest coating coalings with detention is 20 minutes and is the fastest corroded specimens without coating. Hardware test results from each specimen tested showed rising violence in the area coated by electroplating. The test results showed a thick layer on the detention of 40 minutes is the result of sed,memory layers thicker than the initial 30 minutes and 20 minutes.

Abstrak :
The land in Gedangsari Subdistrict area composes of limestone. Many local people consume drinking water from wells that contain high levels of calcium. Many people suffer from urolithiasis. This study aimed to describe calcium or Ca(OH)2 distribution in the well water and explain its relation with urolithiasis incidence. This study was conducted in Gedangsari Subdistrict, Gunung Kidul District from July to November 2013. The study was cross sectional confirmed with titration test in laboratory. Samples were 94 wells of 3,849 well population as selected randomly. Criteria of sample selection included wells used for drinking by the population aged older than 30 years already, with less than 15 meter of depth. Laboratory test of Ca (OH)2 level was conducted by titration. Suspect urolithiasis was clinically diagnosed by doctor and data analysis used chi-square test. Results showed relation between water hardness and urolithiasis (RP = 2.27), although statistically not significant. In conclusion, there was no relation between mineral water consumption, age, and length of stay with urolithiasis incidence in Gedangsari Subdistrict, Gunungkidul District.

Tanah di wilayah Kecamatan Gedangsari mengandung batuan kapur. Masyarakat di daerah ini banyak yang mengkonsumsi air minum dari sumur gali yang mengandung kadar kalsium tinggi, dan banyak yang menderita urolitiasis. Penelitian ini bertujuan untuk mendapatkan gambaran distribusi kalsium atau Ca(OH)2 pada air sumur dan menjelaskan hubungannya dengan kejadian urolitiasis. Penelitian dilakukan di Kecamatan Gedangsari, Kabupaten Gunungkidul selama Juli sampai November 2013. Penelitian dilakukan secara potong lintang dengan konfirmasi uji titrasi di laboratorium. Sejumlah 94 sampel sumur dipilih secara acak dari populasi 3.849 sumur. Kriteria pemilihan sampel adalah sumur gali yang telah digunakan untuk minum oleh penduduk berusia lebih dari 30 tahun, dengan kedalaman kurang dari 15 meter. Pemeriksaan laboratorium kadar kalsium dilakukan dengan titrasi. Dugaan urolitiasis didiagnosis melalui pemeriksaan klinis oleh dokter. Data dianalisis dengan uji kai kuadrat. Hasil analisis menunjukkan hubungan antara kesadahan air dengan urolitiasis (RP= 2.27) namun tidak bermakna secara statistik. Konsumsi air putih, usia, dan lama tinggal tidak berhubungan dengan kejadian urolitiasis di Kecamatan Gedangsari Kabupaten Gunungkidul.