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"Masalah yang sering muncul dalam pembuatan grindil ball lokal adalah belum maksimalnya performa standar yang dipersyaratkan seperti nilai yield hanya bisa dicapai 35% masih dibawah standar 35% tingkat pecah yang tinggi dan masih terdapat cacat shinkage atau porositas. Dari data teknis diatas masih diperlukan upaya penelitan dan pengkajian mendalam untuk menghasilkan kualitas grinding ball lokal agar sesuai dengan spesifikasi pemakaian.Penelitian skala laboratiroum terhadap grinding ball hasil industri kecil-menengah dilakukan muai dari inspeksi mikrostruktur, kualitas permukaan, kerusakan dan komposisi kimia kondisi as-cast. Kondisi grinding ball as-cast selanjutnya dilakukan proses perlakuan panas mulai dari annealing, hardening dan tempering untuk kemudian dilakukan pengamatan nilai kekerasan makro, metalografi kualitatif-mikrostruktur serta kuantitatif-persen fasa terhadap hasi tiap-tiap kondisi perlakuan panas.Hasil penelitian menunjukkan bahwa nilai kekerasan grinding ball kondisi as-cast dapat ditingkatkan dengan perlakuan panas yaitu 430-510 HB menjadi 690-833 HB pada perlakuan hardening. Perolehan mikrostruktur primary carbides sebesar 21-32 % pada as temper sedangkan target untuk as-temper adalah 38,2%, Hal ini terjadi karena pengendapan primary carbides dalam matriks belum maksimal akibat perlakuan panas yang kurang optimum."

"Ketoprofen merupakan obat antiinflamasi yang memiliki kelarutan di dalam air yang rendah. Pada umumnya ketoprofen diberikan secara oral. Namun, memiliki kelemahan yaitu dapat terjadi metabolisme lintas pertama dan pendarahan gastrointestinal. Maka dari itu untuk mengatasi hal tersebut, dapat diberikan secara transdermal yaitu dengan dissolving microneedle. Selain itu, untuk meningkatkan kelarutan dari ketoprofen diperlukan metode yang dapat meningkatkan kelarutan seperti co-grinding. Tujuan penelitian ini adalah untuk memformulasikan dan mengkarakterisasi dissolving microneedle yang mengandung co-grinded ketoprofen. Co-grinded ketoprofen diformulasikan dengan PVA atau PVP dan dilanjutkan karakterisasi yang meliputi spektrofotometri FTIR, analisis difraksi sinar-X, analisis termal, dan uji disolusi. Co-grinded ketoprofen dikombinasikan dengan polimer PVA dan/atau PVA lalu dimasukkan ke dalam dissolving microneedle dan dilakukan evaluasi yang meliputi kekuatan mekanis, kehilangaan massa air selama pengeringan, uji kemampuan insersi, dan uji pelarutan jarum. Berdasarkan hasil uji disolusi co-grinded ketoprofen yang terpilih adalah ketoprofen : PVA = 1 : 2 dengan profil disolusi tertinggi yaitu 99,62 ± 1.56% pada menit ke-60. Dapat disimpulkan bahwa formula dissolving microneedle F8 (5% PVA + 15% PVP) dan F11 (7,5% PVA + 15% PVP) dapat diformulasikan dalam dissolving microneedle yang memberikan kekuatan mekanik yang baik yaitu dengan persentase pengurangan tinggi jarum 0,58 ± 0,21% untuk F8 dan 1,26 ± 0,56 untuk F11, mampu membentuk lubang >25% pada lapisan ketiga parafilm, serta waktu pelarutan jarum pada menit ke-10 untuk F8 dan pada menit ke 22,5 untuk F11.......Ketoprofen is an anti-inflammatory drug that has low water solubility. In general, ketoprofen is given orally. However, it has disadvantages such as first pass metabolism and gastrointestinal bleeding. Therefore, to overcome this, it can be given transdermally, namely by dissolving microneedle. In addition, to increase the solubility of ketoprofen, co-grinding is a method that can be used. The purpose of this study was to formulate and characterize dissolving microneedles containing co-grinded ketoprofen. Co-grinded ketoprofen is formulated in combination with PVA or PVP and characterization is continued using FTIR spectrophotometry, X-ray diffraction analysis, thermal analysis, and dissolution test. Co-grinded ketoprofen was combined with PVA and/or PVA polymer and then put into a dissolving microneedle. The evaluation that is carried out includes mechanical strength, loss of drying, insertion test, and in skin dissolution. Based on the results of the co-grinded ketoprofen dissolution test, the selected ketoprofen : PVA = 1: 2 with the highest dissolution profile was 99.62 ± 1.56% at 60 minutes. It can be said that the dissolving microneedle formula F8 (5% PVA + 15% PVP) and F11 (7.5% PVA + 15% PVP) can be formulated in dissolving microneedle which provides good mechanical strength by reducing the number of needles by 0.58 ± 0 .21% for F8 and 1.26 ± 0.56 for F11, capable of forming holes >25% in the third layer of parafilm, as well as needle coating time at 10 minutes for F8 and at 22.5 minutes for F11."

"The effect of rice husk ash produced at different grinding times on the engineering properties of concrete was studied. Eight rice husk ashes representing different grinding times were used in this investigation. Rice husk ash (RHA) was used to partially replace Portland cement Type I at 15% by weight of cementitious material. The compressive strength of concrete was designed to achieve grade 40 N/mm2 at 28 days. A super plasticizer was added to all mixes to provide workability in the range of 110-120 mm. However, the water to cement ratio (w/c) of the concrete was maintained at 0.49. Based on the results, the morphology of the rice husk ashes was changed by grinding. Optimum grinding time appeared to be approximately 90 minutes, during which time the compressive strength increased significantly. Generally, incorporation of RHA at various grinding times can dramatically decrease or increase the engineering properties of concrete."

"Alat berat membutuhkan kualitas dan kehandalan yang tinggi untuk menunjang produktivitas dan kepuasan pelanggan. Konstruksi utama rangka pada alat berat terbuat dari material baja pelat dan coran yang disambungkan melalui proses pengelasan Gas Metal Arc Welding (GMAW). Kondisi saat ini, produsen belum melihat tegangan sisa dari proses manufaktur sebagai pertimbangan khusus terhadap kualitas produk. Pada penelitian ini, pelat baja SM490 berukuran 200x100 mm disambungkan dengan pengelasan robot GMAW secara butt joint single V 45. Kawat las AWS A5.18-05 ER70S-G berdiameter 1,4 mm digunakan dengan polaritas DCEP bersama gas pelindung CO. Masukan panas, tebal spesimen, dan perlakuan pengelasan divariasikan untuk mengetahui efeknya terhadap tegangan sisa dan sifat mekanik yang dihasilkan. Tegangan sisa diukur tanpa merusak menggunakan mesin portabel berbasis X-Ray Diffraction (XRD). Nilai kekerasan diuji dengan mesin uji keras Microvickers, kekuatan tarik diuji dengan mesin Universal Testing Machine (UTM), serta struktur mikro diamati dengan mikroskop optik strereo dan Electron Probe Micro Analyzer (EPMA). Hasil pengujian menunjukkan kenaikan masukan panas sebesar 350 J menit meningkatkan tegangan sebesar 50-90 MPa pada arah x. Peningkatan ketebalan hingga 30 mm, tidak memberikan perbedaan tegangan sisa yang signifikan. Namun, tebal 40 mm, tegangan sisa justru turun 250 MPa. Ketebalan spesimen hingga 40 mm memberikan penurunan tegangan sisa arah y hingga 400 MPa. Proses gerinda memberikan tegangan sisa tarik hingga 800 MPa lebih tinggi dari tegangan sisa spesimen 2 (tanpa perlakuan). Penambahan preheat dan postheat 150oC tidak memberikan efek terhadap tegangan sisa. Proses gerinda menurunkan tegangan sisa hingga 480 MPa. Hanya jet chisel yang konsisten memberikan tegangan sisa kompresi hingga 480 MPa pada arah x dan y. Kenaikan masukan panas hingga 350 J menit menyebabkan nilai kekerasan HAZ dan logam las turun hingga 50 HB. Ketebalan spesimen hingga 30 mm, cenderung meningkatkan kekerasan hingga 30 HB. Perlakuan preheat dan postheat mengurangi nilai kekerasan hingga 10 HB. Kebalikan dari itu, perlakuan jet chisel mampu meningkatkan kekerasan hingga 12 HB, terutama pada kampuh las. Berbagai variasi masukan panas, ketebalan, dan perlakuan pengelasan tidak memberikan perbedaan yang signifikan kekuatan tarik. Peningkatan ketebalan hingga 40 mm cenderung menurunkan kekuatan hingga 70 MPa. Perlakuan jet chisel memberikan tegangan sisa dan sifat mekanik paling optimal di antara preheat, postheat, dan gerinda.

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Heavy equipment requires high quality and reliability to support productivity and customer satisfaction. The main frame construction on the machine is made of steel plate and castings which are connected through the Gas Metal Arc Welding (GMAW) process. Current conditions, manufacturers have not seen the residual stress from the manufacturing process as a special consideration to product quality. In this study, a 200x100 mm SM490 steel plate was connected by GMAW robots welding with a single V 45 butt joint. AWS A5.18-05 ER70S-G welding wire 1.4 mm in diameter is used with DCEP polarity and CO2 protective gas. Heat input, specimen thickness, and welding treatment are varied to determine their effect on residual stresses and mechanical properties. Residual stress is measured using a non destructive portable machine based on X-Ray Diffraction (XRD). Hardness values were tested with Microvickers Hardness Tester, tensile strengths with Universal Testing Machine (UTM), and microstructure was observed with optical strereomicroscope and Electron Probe Micro Analyzer (EPMA). The test results show an increase in heat input of 350 J / min increases the stress by 50-90 MPa in the x direction. Increased thickness up to 30 mm, does not provide a significant residual stress difference. However, 40 mm thick, the residual stress would drop 250 MPa. Specimen thicknesses of up to 40 mm provide a reduction in the residual stress in the y direction up to 400 MPa. The grinding process provides tensile residual stresses of up to 800 MPa higher than specimen 2 residual stress (without treatment). The addition of preheat and postheat 150oC had no effect on residual stress. The grinding process reduces the residual stress to 480 MPa. Only jets chisel that consistently provide compression residual stresses of up to 480 MPa in the x and y directions. Increase in heat input up to 350 J/min causes the HAZ hardness value and weld metal to decrease to 50 HB. Specimen thickness up to 30 mm, tends to increase hardness up to 30 HB. The preheat and postheat treatments reduce the value of hardness to 10 HB. In contrast, jet chisel treatment can increase the hardness to 12 HB, especially in weld joints. Various variations in heat input, thickness, and welding treatment do not provide a significant difference in tensile strength. Increasing thickness up to 40 mm tends to reduce strength up to 70 MPa. Jet chisel treatment provides the most optimal residual stress and mechanical properties between preheat, postheat and grinding."

"ABSTRAKGrinding ball merupakan salah satu komponen dalam mesin ball mill yangberfungsi untuk menggerus batuan mineral menjadi partikel yang sangat halus(100-300 mesh). Penelitian ini bertujuan untuk mempelajari pengaruhpenambahan unsur paduan berupa khromium, molibdenum, vanadium, dan boronterhadap sifat-sifat mekanik grinding ball terbuat dari material high chromiumwhite cast iron, serta pengaruh volume karbida primer, karbida sekunder, danaustenit sisa terhadap ketahanan aus produk grinding ball.Pembuatan grinding ball berukuran Ø50 mm dilakukan dengan menggunakanteknik pengecoran logam dengan menggunakan tungku induksi. Berikut ini adalahkomposisi kimia dari masing-masing grinding ball dalam penelitian ini: 2,18C -13Cr - 1.38Mo; 1.94C - 13.1Cr - 1.29Mo - 1.307V; 1.89C - 13.1Cr - 1.32Mo -1.361V - 0.00051B; 2.12C - 16.5Cr - 1.55Mo. Proses perlakuan panas dilakukanterhadap material tersebut berupa: (1) subcritical heat treatment (700oC, 1 jam)dengan pendinginan udara atmosfer, (2) hardening (950oC, 5 jam) denganpendinginan udara paksa, (3) tempering (250oC, 1 jam) dengan pendinginan udaraatmosfer. Karakterisasi untuk mengetahui sifat-sifat mekanik dan struktur mikrodari material tersebut dilakukan melalui beberapa pengujian diantaranya adalahanalisa komposisi kimia (Optical Electron Spectroscopy/OES), uji kekerasan(Brinell/ASTM E-10), uji impak (Charpy/ASTM E-23), analisa struktur mikro(mikroskop optik, SEM, XRD), dan uji ketahanan aus/wear rates (laboratory ballmill unit).Dari hasil penelitian diperoleh bahwa penambahan khromium, molibdenum,vanadium, dan boron memberikan peningkatan yang signifikan terhadap nilaikekerasan dan ketahananan aus pada material high chromium white cast iron.Nilai ketahanan aus grinding ball yang tinggi dimiliki oleh material dengankomposisi 1.89C - 13.1Cr - 1.32Mo - 1.361V - 0.00051B (as-cast) dan 2.12C -16.5Cr - 1.55Mo (as-tempered), dimana nilai ketahanan aus material tersebutlebih baik dibandingkan dengan grinding ball impor asal China dan India.Ketahanan aus yang tinggi pada material tersebut diakibatkan oleh nilai kekerasandan ketangguhan yang berimbang, besarnya kandungan volume karbida primerdan sekunder dalam matriks martensit, rendahnya kandungan austenit sisa, sertamorfologi karbida primer dan sekunder yang halus.

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AbstractGrinding ball is one of the components in the ball mill unit to grind the mineralsrock into very fine particles (100-300 mesh). The purpose of this research are toinvestigate the effect of alloying elements, such as chromium, molybdenum,vanadium, and boron on the mechanical properties of grinding ball which is madefrom high chromium white cast iron, and to investigate the effect of primary andsecondary carbide volume fraction and also retained austenite volume on the wearresistance of grinding ball.The manufacturing of Ø50 mm grinding ball was conducted by using the ironcasting process. The following are the chemical composition of the grinding ball?smaterials in this research: 2.18 C-13 Cr- 1.38 Mo; 1.94 C-13.1 Cr-1.29Mo-1.307V; 1.89 C-13.1Cr-1.32 Mo-1.361 V-0.00051B; 2.12 C-16.5 Cr-1.55 Mo. The heattreatment process were conducted into those materials include: (1) Subcritical heattreatment (700 ° C, 1 h) with atmospheric air cooling , (2) Hardening (950oC, 5hours) with forced air cooling, and (3) Tempering (250oC, 1 hour) withatmospheric air cooling. Materials characterization was conducted to find out themechanical properties and micro structure of those materials by using a fewtesting methods, there were: chemical analysis (Optical ElectronSpectroscopy/OES), hardness testing (Brinell/ASTM E-10), impact testing(Charpy/ASTM E-23), micro structure analysis (optical microscope, SEM, XRD),and wear resistance/wear rates testing (laboratory ball mill unit).From the results, the addition of alloying elements, such as chromium, vanadium,molybdenum and boron provided a significant improvement on the hardness andwear resistance of high chromium white cast iron. The high wear resistance wasowned by the material with 1.89 C-13.1Cr-1.32 Mo-1.361 V-0.00051B (as-cast)and 2.12 C-16.5 Cr-1.55 Mo (as-tempered), which were better than grinding ball?smaterial from China and India. It was caused by a good combination betweenhardness and toughness, higher primary and secondary carbide volume fraction inmartensitic matrix, lower retained austenite volume, and finer structure of primaryand secondary carbide."

"Pembuatan obat dalam industri farmasi sangat memerlukan perhatian penting, dalam penerapan CPOB setiap industri farmasi memerlukan sertifikat CPOB yang menandakan proses pembuatan obat dalam industri tersebut telah terkualfiikasi dengan hasil dan mutu yang baik. Beberapa produk di industri farmasi yaitu sediaan tablet yang perlu perhatian penting terkait spesifikasi kritisnya yaitu disolusi dan kadar obat. Nilai disolusi secara langsung mempengaruhi kadar obat dan ketersediaan obat dalam tubuh (Bioavaibility). Beberapa zat aktif memiliki sifat disolusi yang buruk sehingga perlu treatment tambahan untuk meningkatkan disolusi seperti co-grinding. Tujuan dari penelitian ini yaitu untuk mengetahui penyebab variasi nilai disolusi dan alternatif peningkatan nilai disolusi. Metode pengambilan data yang dipakai dalam penelitian ini adalah metode retrospektif dan secara analisis diolah menggunakan Microsoft Exel dan Minitab melalui uji T dan Cpk. Data menunjukkan penyebab variasi antara lain dari karakteristik raw material, proses pengayakan dan kekerasan yang berbeda, alternatif penanganannya dengan kontrol kekerasan dan waktu hancur, pemilihan raw material dengan ukuran partikel kecil dan pembuatan prosedur slugging/grinding untuk meningkatkan disolusi.......Drug manufacturing in the pharmaceutical industry requires important attention, in implementing CPOB each pharmaceutical industry requires a CPOB certificate indicating that the drug manufacturing process in the industry has been qualified with good results and quality. Some of the products in the pharmaceutical industry i.e. tablet dosage need important attention related to their critical specifications, namely dissolution and drug levels. Dissolution value directly affects drug levels and drug availability in the body (Bioavaibility). Some active substances have poor dissolution properties so additional treatment is needed to increase dissolution such as co-grinding. The purpose of this research is to find out the causes of variations in dissolution values and alternatives to increase dissolution values. The data collection method used in this study is the method retrospective and analyzed using Microsoft Exel and Minitab through the T-test and Cpk test. The data shows the causes of variation including the characteristics of the raw material, the different sieving processes, and hardness, alternative handling by controlling hardness and disintegration time, choosing raw materials with small particle sizes, and making slugging/grinding procedures to increase dissolution."

"This book offers a comprehensive collection of micro electrical discharge machining (EDM) processes, including hybrid processes. It discusses the theory behind each process and their applications in various technological as well as biomedical domains, and also presents a brief background to various micro EDM processes, current research challenges, and detailed case studies of micro-manufacturing miniaturized parts. The book serves as a valuable guide for students and researchers interested in micro EDM and other related processes."

"In this volume, the design, manufacture and control technology of precision machines are introduced to achieve the concrete requirements for precision engineering. The state-of-the-art of precision machining processes including precision turning, milling, grinding and lapping/polishing are discussed. The key components of precision machines are introduced as well, such as precision spindles, control systems, tools and grinding wheels etc. For design part, methods for the design and simulation of the general structure of precision machines as well as the key components are described in details. For manufacture part, fabrication and assembly technologies for different types of precision machines are introduced. For control part, control system, measurement and compensation technology for precision machines are discussed. The information provided in the book will be of interest to industrial practitioners and researchers in the field of precision machines and their control."