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"[Penelitian ini bertujuan untuk mengetahui pengaruh kekasaran, proses phosphating, serta ketebalan adhesive bonding terhadap ketahanan delaminasi komposit laminat. Variasi kekasaran substrat, yaitu pada rentang 5-8 μm dan 10-13 μm, variasi terhadap proses phosphating, yaitu ada yang melalui proses phosphating dan ada yang tidak, serta variasi ketebalan adhesive baik primer ataupun topcoat dengan rentang 1-5 μm, 6-10 μm, serta 11-15 μm. Pembentukan komposit laminat ini dilakukan melalui proses transfer moulding pada suhu 160 C selama 450 detik. Komposit laminat yang sudah terbentuk kemudian diuji peel-off untuk mengetahui kekuatan delaminasinya lalu dikarakterisasi dengan SEM-EDX. Hasil menunjukan bahwa kekasaran permukaan, lapisan zinc phosphate, serta ketebalan adhesive bonding mempengaruhi ketahanan delaminasi komposit laminat yang diinterpretasikan dengan kekuatan ikat antarlapisan dan visual delaminasi. Kekasaran optimum terjadi pada rentang 10-13 μm dengan kekuatan ikat 179,68 N dan visual delaminasi R-R sebanyak 35%. Adanya lapisan zinc phosphate memberikan nilai kekuatan ikat optimum sebesar 157,38 N dan visual delaminasi R-R sebanyak 50%. Ketebalan adhesive primer optimum terjadi pada rentang 1-5 μm dengan kekuatan ikat 163,35 N dan visual delaminasi R-R sebanyak 50%. Ketebalan adhesive topcoat optimum terjadi pada rentang 6-10 μm dengan kekuatan ikat sebesar 154,65 N dan visual delaminasi R-R sebanyak 41,6%.;This study aims to determine the effect of roughness, phosphating process, and the thickness of the adhesive bonding into delamination resistance of laminate composite. Variation of the substrate roughness are 5-8 μm and 10-13 μm. Some substrates are coated by zinc phosphate and other substrate are uncoated. Variations of the thickness of adhesive primer and adhesive topcoat are in a range of 1-5 μm, 6-10 μm, and 11-15 μm. The process of forming the laminate composite occurs through transfer molding process at 1600C in 450 seconds. Laminate composite that has been formed then tested by peel-off test to determine the strength of delamination. Visual of delamination was characterized by SEM-EDX. The results showed that the optimum surface roughness occurs in the range of 10-13 μm with bonding strength 179.68 N and 35% of R-R visual. The coated substrate has a higher bonding strength compared to uncoated substrate, which is 157.38 N and 50% of R-R visual. The optimum thickness of adhesive primer occurs in the range of 1-5 μm with bonding strength is 163.35 N and 50% of R-R visual. While the optimum thickness of adhesive topcoat occurs in the range of 6-10 μm with a bonding strength is 154.65 N and 41,6% of R-R visual;This study aims to determine the effect of roughness, phosphating process, and the thickness of the adhesive bonding into delamination resistance of laminate composite. Variation of the substrate roughness are 5-8 μm and 10-13 μm. Some substrates are coated by zinc phosphate and other substrate are uncoated. Variations of the thickness of adhesive primer and adhesive topcoat are in a range of 1-5 μm, 6-10 μm, and 11-15 μm. The process of forming the laminate composite occurs through transfer molding process at 1600C in 450 seconds. Laminate composite that has been formed then tested by peel-off test to determine the strength of delamination. Visual of delamination was characterized by SEM-EDX. The results showed that the optimum surface roughness occurs in the range of 10-13 μm with bonding strength 179.68 N and 35% of R-R visual. The coated substrate has a higher bonding strength compared to uncoated substrate, which is 157.38 N and 50% of R-R visual. The optimum thickness of adhesive primer occurs in the range of 1-5 μm with bonding strength is 163.35 N and 50% of R-R visual. While the optimum thickness of adhesive topcoat occurs in the range of 6-10 μm with a bonding strength is 154.65 N and 41,6% of R-R visual, This study aims to determine the effect of roughness, phosphating process, and the thickness of the adhesive bonding into delamination resistance of laminate composite. Variation of the substrate roughness are 5-8 μm and 10-13 μm. Some substrates are coated by zinc phosphate and other substrate are uncoated. Variations of the thickness of adhesive primer and adhesive topcoat are in a range of 1-5 μm, 6-10 μm, and 11-15 μm. The process of forming the laminate composite occurs through transfer molding process at 1600C in 450 seconds. Laminate composite that has been formed then tested by peel-off test to determine the strength of delamination. Visual of delamination was characterized by SEM-EDX. The results showed that the optimum surface roughness occurs in the range of 10-13 μm with bonding strength 179.68 N and 35% of R-R visual. The coated substrate has a higher bonding strength compared to uncoated substrate, which is 157.38 N and 50% of R-R visual. The optimum thickness of adhesive primer occurs in the range of 1-5 μm with bonding strength is 163.35 N and 50% of R-R visual. While the optimum thickness of adhesive topcoat occurs in the range of 6-10 μm with a bonding strength is 154.65 N and 41,6% of R-R visual]"

"Material film adhesive yang digunakan PT Dirgantara Indonesia untuk pembuatan pesawat memiliki batas waktu penyimpanan di suhu ruang yang disebut work life. Untuk mengevaluasi work life film adhesive Z-15.429 telah dilakukan penelitian dengan tiga variasi lama penyimpanan film adhesive di suhu ruang yaitu 97.5 jam, 173 jam, dan 270.25 jam yang selanjutnya masing-masing diuji mekanik berupa shear test, peel test, dan drum peel test. Selain itu dilakukan juga uji Fourier Transform Infra Red (FTIR) untuk mengamati proses polimerisasi di suhu ruang dan pengamatan kerusakan akibat uji mekanik menggunakan mikroskop optik. Hasil penelitian menunjukkan bahwa hanya spesimen dengan film adhesive yang disimpan selama 97.5 jam di suhu ruang saja yang memenuhi standar PT Dirgantara Indonesia dengan nilai rata-rata kekuatan geser, nilai rata-rata beban pengelupasan hasil peel test, dan nilai rata-rata beban pengelupasan hasil drum peel test berturut-turut (38.06 ± 2.16) MPa, (355.62 ± 13.36) N, dan (648.17 ± 20.71) N serta mengalami 100% kerusakan kohesif.

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Adhesive film materials that are used by PT Dirgantara Indonesia for aircraft manufacturing have a time limit in room temperature storage that is called work life. To evaluate the work life of Z-15.429 adhesive films, a study was conducted for this adhesive film that was stored at room temperature within three different durations, namely 97.50, 173, and 270.25 hours. Each sample for each duration was then mechanical tested, including shear, peel, and drum peel tests. Moreover, Fourier Transform Infra Red (FTIR) was applied to observe the polymerization process of the adhesive film and optical microscope observation was conducted to study the failure of the specimens after mechanical testing.

The results showed that only adhesive film specimen which was stored for 97.50 hours in room temperature have met the PT Dirgantara Indonesia standard with the average values of shear strength, peeling load of peel, and peeling load of drum peel were (38.06 ± 2.16) MPa, (355.62 ± 13.36) N, and (648.17 ± 20.71) N respectively, with 100% of cohesive failure."

"[Penggunaan semen seng fosfat yang tidak memperhatikan rentang waktu penyimpanan sebelum kedaluwarsa dapat memengaruhi kuat tekan semen. Tujuan penelitian adalah mengetahui perbedaan nilai kuat tekan semen seng fosfat dengan berbagai rentang waktu penyimpanan sebelum kedaluwarsa. Tiga kelompok semen seng fosfat dengan tanggal kedaluwarsa berbeda (t=6mm; d=4mm) merk GC Elite Cement 100 dilakukan uji kuat tekan menggunakan universal testing machine (crosshead speed 1 mm/menit dan beban 250 kgF). Hasil menunjukkan terdapat perbedaan bermakna (p<0,05) nilai kuat tekan semen seng fosfat kelompok III dengan kelompok I dan II. Dapat disimpulkan bahwa terdapat penurunan nilai kuat tekan pada semen yang mendekati waktu kedaluwarsa, Usage of zinc phosphate cement that do not notice its shelf life before expired can affect its compressive strength. To observe difference compressive strength value of zinc phosphate cement with different shelf life before expired. Three groups of zinc phosphate cement (GC Elite Cement 100) with different expiry dates (h=6mm; d=4mm) were tested for compressive strength using universal testing machine (crosshead speed 1mm/minute and load cell 250 kgF). There is significant difference (p<0,05) compressive strength of zinc phosphate cement group III to group I and II. There is a decrease of compressive strength of zinc phosphate cement near expiry date.]"

"Latar Belakang: Penyakit gigi dan mulut yang paling banyak ditemukan di Indonesia adalah karies gigi. Penggabungan antara lilin propolis, yang mempunyai sifat antibakteri, dan CPP-ACP, yang merupakan agen remineralisasi, sebagai bahan aktif di dalam medium permen karet CPP-ACP-Propolis merupakan suatu keuntungan dan inovasi baru dalam upaya pencegahan karies.Tujuan: Menganalisis kerja dari CPP-ACP dan lilin propolis jika digabungkan dalam satu formulasi permen karet, dilihat dari kadar ion kalsium dan ion fosfat yang dilepas CPP-ACP dan penekanan massa biofilm S.mutans oleh lilin propolis, terhadap saliva subjek karies. Metode: Dilakukan simulasi pengunyahan lima konsentrasi permen karet (0%propolis, 0%CPP-ACP; 0%propolis + CPP-ACP; 2%propolis + CPP-ACP; 4%propolis + CPP-ACP; 6%propolis + CPP-ACP) secara in vitro pada 25 sampel saliva subjek karies kemudian diuji menggunakan alat Atomic Absorption Spectrophotometer untuk melihat kadar ion kalsium, Ultraviolet-Visible Spectrophotometer untuk melihat kadar ion fosfat, serta uji crystal violet untuk menganalisis penurunan massa biofilm.Hasil: Terdapat peningkatan kadar kalsium yang signifikan pada saliva + eluen permen karet dibandingkan dengan kontrol saliva, dengan tingkat pelepasan kalsium tertinggi dari permen karet CPP-ACP + 2% propolis. Terdapat peningkatan kadar fosfat yang tidak signifikan antara kontrol saliva dan saliva+eluen permen karet. Terjadi penurunan massa biofilm S.mutans yang signifikan antara kontrol saliva dan saliva+eluen permen karet, dengan penurunan terbanyak oleh konsentrasi permen karet CPP-ACP dan CPP-ACP+6%propolis. Simpulan: Simulasi pengunyahan permen karet CPP-ACP-Propolis menghasilkan peningkatan kadar ion kalsium dan ion fosfat, serta penurunan massa biofilm S.mutans pada saliva subjek karies.

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Background: The most frequent oral disease found in Indonesia is caries. The combination of propolis wax, which is an antibacterial agent, and CPP-ACP, which is a remineralization agent, as the active compounds in chewing gum is an advantage and a new innovation in caries prevention. Aim: To analyze the effect of CPP-APP and propolis wax if both are combined in a chewing gum formulation, observed from the calcium and phosphate ion level released by CPPACP and the emphasis of S.mutans biofilm mass by propolis wax, towards cariesactive subjects’ saliva.Methods: Chewing simulation being done in vitro to 25 caries-active subjects’ saliva sample using five concentrations of chewing gums (0%propolis,0%CPP-ACP; 0%propolis+CPP-ACP; 2%propolis+CPP-ACP; 4%propolis+CPP-ACP; 6%propolis+CPP-ACP), then being tested using Atomic Absorption Spectrophotometer to analyze calcium ion level, Ultraviolet-Visible Spectrophotometer to analyze phosphate ion level, and biofilm assay using crystal violet to analyze the decline in biofilm mass.Results: After chewing simulation, calcium ion level on saliva+gum eluent have increased significantly compared to saliva control, with the highest calcium level released by CPP-ACP +2%propolis chewing gum. There is insignificant phosphate level change between saliva control and saliva + gum eluent. There is also significant decline of S.mutans biofilm mass in the saliva + gum eluent, most decline by CPP-ACP chewing gum and CPP-ACP+6%propolis. Conclusion: CPP-ACP-Propolis chewing simulation generate the increase of calcium and phosphate ion level and the decline in S.mutans biofilm mass of caries-active subjects’ saliva"

"Seleksi bakteri pelarut fosfat dan kajian produksi sel bakteri terpilih menggunakan medium Pikovskaya dengan modifikasi sumber karbon (glukosa teknis dan molase) dan nitrogen (urea dan tepung ikan) telah dilakukan. Penelitian bertujuan menyeleksi 20 isolat bakteri yang memiliki aktivitas pelarut fosfat terbaik dalam medium mengandung senyawa Ca3(PO4)2 dan batuan fosfat serta mengkaji komposisi medium produksi sel bakteri pelarut fosfat isolat terpilih menggunakan medium Pikovskaya dengan variasi sumber karbon dan sumber nitrogen. Produksi sel dilakukan selama 48 jam menggunakan 5 variasi medium Pikovskaya dengan komposisi sumber karbon dan nitrogen yang berbeda (M1, M2, M3, M4, dan M5). Metode Total Plate Count (TPC) digunakan untuk menghitung jumlah sel bakteri yang diuji tiap interval 6 jam. Hasil penelitian menunjukkan isolat GRTL 6.2 dan GRTL 7.3 diidentifikasi sebagai Burkholderia seminalis dan Burkholderia cenocepacia. Identifikasi bakteri dilakukan oleh Indonesia Culture Collection (InaCC), LIPI, Cibinong. Kedua isolat memiliki rata-rata indeks pelarutan fosfat (IPF) tertinggi dengan nilai masing-masing 4,38 dan 3,92, selanjutnya digunakan dalam tahap kajian produksi sel BPF. Jumlah sel kedua isolat pada akhir masa inkubasi (48 jam) berkisar 5,4 - 5,6x1013 CFU/ml. Data statistik dengan uji Anova (P>0,05) menunjukkan jumlah sel kedua isolat pada kelima medium perlakuan tidak terdapat perbedaan nyata. Glukosa teknis dan molase dapat menggantikan glukosa sebagai sumber karbon, sedangkan urea dan tepung ikan dapat menggantikan yeast extract sebagai sumber nitrogen untuk produksi sel bakteri pelarut fosfat.

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Screening of phosphate solubilizing bacteria (PSB) and study of producing selected bacteria cell by using Pikovskaya medium with carbon source (technical glucose and molasses) and nitrogen (urea and fish meal) modification have been done. This research aims at selecting 20 bacterial isolates that have phosphate solubilizing activity in Pikovskaya medium with a compound Ca3(PO4)2 and phosphate rock as well as examining the composition of production medium of the PSB cell selected using Pikovskaya medium with a variety of carbon and nitrogen sources. Cell production was done within 48 hours by using five types of medium Pikovskaya with different variations in the composition of carbon and nitrogen sources (M1, M2, M3, M4, and M5). Total Plate Count (TPC) method was used to calculate the number of bacterial cells that were tested with 6 hours interval each.

The result shows isolates GRTL 6.2 and GRTL 7.3 were identified as Burkholderia seminalis and Burkholderia cenocepacia. Identification of bacteria carried by Indonesia Culture Collection (InaCC), LIPI Cibinong. Both isolates had an average of phosphate solubilizing index (PSI) with the highest value of each is 4.38 and 3.92, and they are later used in the assessment stage of PSB cell production. Results calculation the two isolates cell numbers at the end of the incubation period (48 hours) is 5,4 - 5,6x1013 CFU/ml.

Statistical data by Anova (P> 0.05) showed that there is no real difference in an average yield of TPC of both isolates in the fifth treatment medium. Technical glucose and molasses can replace glucose as the carbon source whereas urea and fish flour can replace yeast extract as nitrogen source in the Pikovskaya medium for the production of phosphate solubilizing bacterial cells."

"This book deals with the most recent numerical modeling of adhesive joints. Advances in damage mechanics and extended finite element method are described in the context of the finite element method with examples of application. The book also introduces the classical continuum mechanics and fracture mechanics approach and discusses the boundary element method and the finite difference method with indication of the cases they are most adapted to. At the moment there a no numerical technique that can solve any problem and the analyst needs to be aware of the limitations involved in each case."

"Tulang adalah jaringan tubuh yang dapat menyembuhkan dirinya sendiri apabila mengalami kerusakan. Namun pada beberapa kasus cacat tulang, cangkok tulang (bone graft) atau material pengganti tulang dibutuhkan untuk membantu penyembuhan jaringan. Terdapat tiga jenis cangkok tulang yaitu autograf, allograf, dan xenograf. Karena terbatasnya sumber tulang untuk cangkok tulang, peneliti mencari material alternatif sebagai pengganti tulang. Biokeramik telah banyak diteliti karena dinilai sebagai material yang paling menjanjikan sebagai pengganti tulang. Bifasik kalsium fosfat (BCP), tersusun atas hidroksiapatit (HA) dan b-trikalsium fosfat (b-TCP), menunjukkan potensi besar sebagai material pengganti tulang karena sifatnya yang bioaktif, biokompatibel, dan laju degradasi yang cocok dengan laju pertumbuhan tulang. Hidroksiapatit di sintesis dengan metode presipitasi gelombang mikro. Serbuk hidroksiapatit dicampurkan ke dalam larutan polivinil alkohol yang bertujuan untuk menghasilkan hidroksiapatit dengan mikrostruktur berpori. Selanjutnya, serbuk hidroksiapatit dipadatkan dan disintering dengan variasi temperatur sintering mulai dari 800 °C hingga 1300 °C untuk mempelajari perubahan fasa dan mikrostruktur dari hidroksiapatit. Fase kristal, gugus fungsi, morfologi, dan sifat mekanik diuji dengan X-ray Diffraction (XRD), Fourier Transform Infrared FTIR, Scanning Electron Microscope (SEM), dan Mikro Vickers. XRD menunjukkan terjadi perubahan fase HA menjadi b-TCP pada temperatur 1000 – 1300 °C. Hasil FTIR menunjukkan tidak ditemukannya gugus vinil yang berarti PVA telah sepenuhnya terdegradasi akibat sintering dengan temperatur tinggi. Pori yang dihasilkan memiliki bentuk spherical-like dengan ukuran yang semakin besar seiring dengan peningkatan temperatur sintering. Nilai kekerasan maksimal sebesar 4,166 GPa dihasilkan oleh hidroksiapatit yang disintering pada temperatur 1200 °C dan kekerasan menurun pada temperatur diatasnya karena peningkatan dekomposisi HA.

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Bone is a tissue that can heal by itself. However, for some cases of bone defects, a bone graft or bone substitute is needed to help bone tissue to heal. There are three kinds of bone grafting which is autograft, allograft, and xenograft. Due to the limited source of bone for bone grafting, researchers eager to find an alternative material for bone substitution. Bioceramic has been widely studied because they are considered the most promising material for bone tissue substitution. Biphasic calcium phosphate (BCP), composed of hydroxyapatite (HA) and b-tricalcium phosphate (b-TCP), has shown great potential as a bone substitute material due to its bioactive, biocompatible properties and the rate of degradation that corresponds to the growth rate of bone. Hydroxyapatite nanocrystal was synthesized through the microwave-assisted precipitation method. Hydroxyapatite powder was later added into a polyvinyl alcohol solution, which is aimed to produced hydroxyapatite with a porous microstructure. Hydroxyapatite powder was compacted and sintered at various temperatures, from 800 – 1300 °C, to study the transformation of phase and microstructure of hydroxyapatite. The crystal phase, functional groups, morphology, and hardness of biphasic calcium phosphate were determined through X-Ray Diffraction (XRD), Fourier Transform Infrared (FTIR) Spectroscopy, Scanning Electron Microscope (SEM), and Vickers Microhardness Tester. XRD result shows that the b-TCP phase appears due to the decomposition of HA at 1000 – 1300 °C. FTIR result shows there is no sign of a vinyl functional group, which means that PVA has fully degraded due to sintering with high temperature. Produced pores have a spherical-like shape and become larger as the sintering temperature reaches up to 1300 °C. The maximum hardness value of 4,166 GPa obtained from the hydroxyapatite sintered at 1200 °C and slightly decreased at 1300 °C due to increased decomposition of HA"

"Dalam penelitian ini telah dilakukan fabrikasi suatu kamar reaksi baru yang akan ditempatkan pada alat difraksi sinar X (XRD). Penelitian dilanjutkan dengan investigasiex situ dari serbuk kalsium fosfat hasil sintesis kimiawi dengan variasi waktu kontak dengan ammonia selama 0, 3, 4, 5, 15, dan 36 jam yang secara khusus ditujukan untuk menginvestigasi proses mineralisasi kalsium fosfat. Selama transformasi kalsium fosfat menjadi hidroksiapatit, telah terdeteksi adanya pembentukan fase-fase perantara, yaitu brushite dan monetite, melalui karakterisasi XRD. Hasil penelitian juga menunjukkan bahwa meningkatnya waktu kontak ammonia dari 4 hingga 36 jam mampu meningkatkan ukuran kristalit mineral dari 9.3 menjadi 16.1 nm. Hasil-hasil penelitian ini dapat dijadikan acuan untuk investigasi lebih lanjut mengenai mineralisasi kalsium fosfat, khususnya melalui investigasi in situ via XRD.

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In the current research, fabrication of newly-designed reaction chamber for X-Ray Diffraction (XRD) has been conducted, followed by ex situ investigation of chemically synthesized CaPwith various time of 0, 3, 4, 5, 15, and 36 hours in contact with ammonia. This route was specifically aimed at investigating the mineralization of CaP. During the transformation of CaP toHydroxy Apatite(HA), formation of intermediate phases, i.e. brushite (DCPD) and monetite (DCPD) is well detected by XRD characterization. Increasing of contact time with alkali atmosphere from 4 to 36 hours has increased the crystallite size of CaP minerals from 9.3 to 16.1 nm. Those results can be a baseline for further investigation of CaP mineralization, especially in situ XRD investigation."