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"ABSTRACTPermasalahan yang selalu ada pada dunia industri adalah terjadinya gangguanfungsi peralatan yang digunakan, akibat kerusakan dari komponen penyusunnyaKrisis ekonomi yang terjadi di Indonesia secara tidak langsung telah menyebabkanbanyak perusahaan melakukan efisiensi, diantaranya adalah menunda penggantiansuku cadang dan melakukan cara alternatif dengan melakukan rekonsiliasi padakomponen yang rusak tersebut. Mechanical seal adalah salah satu komponen yangterkena dampak terjadinya krisis ekonomi hingga harganya menjadi mahal dan sulitdiperoleh. Sebelum krisis terjadi, kerusakan komponen ini akan segera dilakukanpenggantian komponen yang baru. Oleh karena itu, efisiensi yang perludipertimbangkan selama krisis, adalah melakukan alternatif rekondisi padakomponen ini.Dalam melakukan rekondisi, terlebih dahulu mengetahui jenis mechanical sealyang akan direkondisi, jenis kerusakan yang teijadi, pemilihan material yangdigunakan berdasarkan ketentuan dan ketersediaan di pasaran, dan memperkirakanusia pakai yang dicapai. Efisiensi biaya diukur dari perbandingan biaya rekondisidengan harga pembelian baru komponen mechanical seal.

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"Kontaminasi bakteri pada tumpatan sementara dapat menyebabkan kegagalan perawatan. Tujuan penelitian ini adalah untuk mengetahui perbandingan sealing ability tumpatan sementara berbasis zinc oxide eugenol dan non-eugenol. Dua puluh gigi premolar yang telah diekstraksi ditumpat 4 bahan tumpatan sementara zinc oxide yang berbeda lalu direndam selama 5 hari dalam methylene blue 1% dan diuji penetrasi pewarna dengan skoring menggunakan alat stereomikroskop Nikon SMZ800, Japan (perbesaran 63x). Hasil penelitian menunjukkan sealing ability pada tumpatan sementara zinc oxide non-eugenol lebih baik dibandingkan zinc oxide eugenol.

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Bacteria contamination on temporary filling can cause treatment failure. The aim of this study was to evaluate the sealing ability of zinc oxide eugenol and noneugenol based temporary filling by dye penetration test using scoring. Twenty extracted maxillary premolar were filled with 4 different temporary filling, then immersed in 1% methylene blue solution for 5 days and evaluated under stereomicroscope Nikon SMZ800, Japan (63x). Results showed that sealing ability of zinc oxide non-eugenol based temporary filling was better than temporary filling based of zinc oxide eugenol."

"The Aluminum 7075 (Al 7075) alloy is a precipitation hardening material instead of a strain hardening material. These mechanical properties are of a particular microstructure obtained by thermo-mechanical treatments. Among other things, this is a complicated microstructure which is responsible for the mechanical performance. The evolution of the mechanical properties of aluminum alloys is dependent on aging time parameters after heat treatment. In this study, the material has undergone a tempering heat treatment followed by a series of tensile tests. The experimental data (tensile curves in three directions during maturation time) is used to describe the evolution of the mechanical characteristics in terms of loading directions and maturation time, denoted respectively as: Ψ and t. The tensile curves are the source of data to begin the problem of identifying the behavior law of studied material using Barlat?s model and Hollomon?s isotropic hardening law. Thus, from the identified parameters (anisotropy coefficients and hardening coefficients), the evolution of the Lankford coefficient, deformation rate and load surfaces during the maturation time for three load directions (0°: rolling direction, 45° and 90°) are described. This study allows optimizing the response of the aluminum alloy to plastic strains, resulting from forming processes measured against the best time during maturation and the best load direction."

"The definition of the physical and mechanicalproperties of sugarcane trash pellets were necessary for the designconsiderations relating to storage, handling andprocessing equipment. The mixing ratios of groundsugarcane trash:cassava starch:water content (1.0:0.25:0.85 and 1.0:0.25:1.40 by weight) and pelleting speeds (100, 120, 140, and 160 rpm) were considered to determine their effects on bulkdensity, true density, porosity, durability and compressive strength. The results show that the mixing ratio byweight of 1.0:0.25:0.85 and pelleting speed of 120to 140 rpm were optimum for producing the sugarcane trash pellets. At the moisture content of 12.01% (wb), the bulk density, true density, durability and compressive strengthof biomass pellets were in the range of 330.93 to 365.00 kg/m3, 860.38 to 918.43 kg/m3, 99.34 to 99.46 % and 5.15 to 6.43 MPa, respectively."

"The presentstudy investigated the mechanical properties and microstructure of ultrafinegrained (UFG) brass processed by four passes of equal channel angular pressing(ECAP) and annealed at elevated temperatures. The mechanical properties of allsamples were assessed using tensile and micro-hardness tests. Microstructureanalysis was performed using optical microscopy (OM) and scanning electronmicroscopy (SEM). Ultimate tensile strengths (UTS) and yield strengths (YS) of878 and 804 MPa, respectively, ductility of 15%, and hardness of 248 HV wereobtained for samples processed by four passes of ECAP with equivalent truestrain of 4.20. Annealing at 300°C caused UTS and YS to decrease significantly,to 510 and 408 MPa, respectively, ductility to increase to 28%, and hardness todecrease to 165 HV. Fractography analysis of un-annealed samples after fourECAP passes showed small brittle fractures with shallow dimpling. Ductilefailures were found on annealed samples. After four ECAP passes, themicrostructure of un-annealed samples was UFG and dominated by lamellar grainwith shear band. In contrast, after annealing, the microstructure changed dueto recrystallization, showing nucleation and grain growth."

"AbstrakPerformansi boiler adalah menunjukkan kapasitas jumlah transfer energi panas untuk dapat menghasilkan kapasitas produksi aliran uap. pada pengoperasian boiler tipe fulton 30e, maka performansi akan dianalisis pada kondisi tekanan empat, lima, enam, tujuh dan delapan bar (abs) pada fraksi kualitas uapnya. dari hasil analisis pengujian operasi boiler tipe fulton 30e di laboratorium teknik konversi energi, maka semakin tinggi tekanan maka efisien boiler semakin tinggi efisiensi boiler, yaitu pada tekanan 8 bar dengan konsumsi bahan bakar 35,7% liter dan kapasitas uap 278,565 kg/jam efisiensinya 65,6%. maka untuk meningkatka performansi operasi boiler direkomendasikan pada tekanan kerja maksimum. untuk meningkatkan efisiensi maka rencana tahapan selanjutnya untuk melakukan analisis rugi-rugi dan rancangan heat recovery untuk boiler itu sendiri. "

"The aim of this study was to know the success and the difference of pit & fissure sealant material penetration of composite resin type (UltraSeal XT Plus) into fissure by using syringe blue micro tips and syringe white mini brush tips in fissure clossure efforts for caries prevention of permanent teeth. This study was conducted to 30 maxillary first premolar, using syringe blue micro tips, and 30 maxillary first premolar, using syringe white mini brush tips. The samples, then were made smears and observed by optic microscope with 300 times magnification. The result of this study showed that mean of pit & fissure sealant material penetration of composite resin type into fissure by using syringe blue micro tips was (67.93 ± 13.09) %. By using syringe white mini brush tips was (92.96 ± 6.18) %. With t-test. It showed a significant difference (t = 9.84, p<0.01)"