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"ABSTRAKPenelitian ini bertujuan untuk mempelajari sifat-sifat dari lapisan tipis alumina. Sol alumina berbasis air yang diturunkan dari prekursor organik aluminium secondary butoxide (ASB) dibuat melalui proses Yoldas. Pengaruh derajat hidrolisis dan keasaman dipelajari dengan XRD dan FT-Raman spectrometer. Selanjutnya boehmit yang terbentuk dipanaskan dan dikarakterisasi seperti sebelumnya. Untuk mempelajari sifat-sifat lapisan boehmit dideposisikan pada berbagai subtrat (gelas, Al, Cu, dan Stainless steel). Morfologi dari film diamati dengan mikroskop optik dan SEM. Ketebalan dari film ditentukan dengan metode indentasi dengan UMIS-2000 menggunakan indenter sferis 1 µm. ketebalan film tergantung dari gaya adhesi antar sol dan subtrat. Ketebalan film pada 5 x pelapisan untuk subtrat SS antara 60 nm sampai dengan 120 nm. Modulus dan kekerasan dpelajari dengan indenter sferis 10 µm dan biaxial bending. Hasil dari penelitian ini disajikan dalam Bab 6.

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ABSTRACTThe aim of this project is to investigate the properties of sol-gel deposited alumina films. The water base alumina sol was derived from alumina secondary butoxide through Yoldas process. The effect of hydrolysis and acidity were studied using XRD and FT-Raman spectrometer in order to characterize the structure of boehmite. Furthermore, produced boehmite were fired and characterized as previous methods. For studying the film properties, the boehmite was deposited onto substrates (glass, Al, Cu and stainless steel). The surface properties were observed using an optic microscope and SEM. The thickness of the film was determined through indentation method using UMIS-2000 with 1 µm spherical tipped indenter. The thickness of the film depends on the adhesion force between boehmite sol and substrate. The film thickness of stainless steel-coated alumina was found between 60 nm to 120 nm. The elastic modulus and hardness of the film were investigated using 10 µm spherical indenter and biaxial bending test. The result of this project is presented in Chapter 6."

"Emisi asap (smoke) merupakan polutan utama pada mesin diesel. Smoke dihasilkan oleh pembakaran akibat kekurangan oksigen. Hal tersebut kebanyakan terjadi pada inti (core) spray yang mempunyai λ < 0,8. Secara tradisional pengurangan emisi smoke dapat dicapai dengan cara modifikasi sistem bahan bakar, geometri mesin, kontrol dari mesin atau menggunakan kombinasi dari ketiga cara diatas. Metode yang lain yang sering digunakan adalah menggunakan bahan bakar reformulasi atau biodiesel yang mengandung oksigen. Hal ini karena penambahan oksigen didalam bahan bakar menyebabkan inti dari spray menjadi tidak terlalu kaya, sehingga memungkinkan penurunan emisi smoke. Beberapa studi telah membuktikan hal ini, namun mekanisme kerja oksigen dalam hal ini belum begitu jelas.Oleh karena itu studi kali ini berusaha untuk mempelajari lebih jauh peranan dan efek oksigen dalam proses pembakaran dengan cara ekperimen dengan menggunakan bahan bakar solar murni dan dibandingkan dengan bahan bakar campuran solar-biodiesel. Pada studi kali ini proses pembakaran didalam ruang bakar dipelajari dengan menggunakan analisa heat release, tekanan puncak silinder dan waktu tunda pembakaran. Dan hasil penelitian dengan variasi beban nampak bahwa pengurangan fraksi pembakaran difusi menghasilkan pengurangan emisi smoke. Hasil eksperimen memperlihatkan adanya hubungan antara durasi Mixing controlled combustion dengan emisi smoke yang dihasilkan. Durasi pembakaran pada fase tersebut memegang peranan penting dalam penurunan emisi smoke. Analisa heat release menunjukkan penggunaan bahan bakar solar-Biodiesel dalam hal ini menggunakan Metyl Ester 30 % berat, mempersingkat waktu pembakaran pada mixing controlled combustion dan memperpanjang lama pembakaran di late combution.

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Smoke emission is the major pollutant from diesel engine. Smoke is emitted in diesel engine because fuel injected into combustion chamber burns with insuffient oxygen. The process takes place in the spray core that has λ < 0,8. Reductions of diesel engine emissions have traditionally been achieved through modification fuel system, combustion chamber geometry, engine control or combination of those. Another method to decrease smoke emissions is by using reformulating diesel fuel or biodiesel that contains oxygen in the fuel. The additional oxygen content into fuel would make a leaner mixture in the core spray. Therefore oxygenated diesel fuel offers the possibility of reduction particulates matter emissions significantly. The mechanism by which oxygen content leads to particulates matter reductions is still unclear.In this study author would attempt to further study about the oxygen effect in combustion process experimentally using diesel fuel and of mixture diesel fuel-biodiesel. The study was conducted using in-cylinder pressure analysis to obtain heat release, peak pressure, and ignition delay. The results load variation experiment so that the smoke would increase with the diffusion combustion fraction. The experiment results show a relationship between mixing controlled combustion durations with the smoke emitted from the engine. The duration in this phase combustion plays important role on smoke reductions. Heat release rate shows that using mixture of diesel fuel-biodiesel, in these case methyl ester sawit 30% by mass, would decrease premixed and mixing controlled combustion durations and increase late combustion duration."

"Nowadays, instant film is being an alternative choice on supportive radiographic examination in dentistry. Early diagnosis of alteration in periodontal tissue, especially gingiva which has a low density, on a conventional radiographic image often give a difficulty to the dentists. Detail image of soft tissue can be gained by decreasing radiographic contrast. Added aluminium filter itself can influence radiographic contrast. The purpose of this research is to observe the effect of coin Rp. 100,- as added aluminium filter in increasing the detail of intraoral image of interdental object with D-speed instant film Hanshin© on phantom. Sixty radiographic images were taken. 30 films added with aluminium filter and 30 films without any added filter. The examination was taken by measuring the height of vertical dimention of interdental papilla?s opacity with caliper. Data gained in the region of interest which was the interdental papilla between mandibular right first molar and mandibular second molar were analize with independent-sample t test. The result showed that there is differences in mean of the height of interdental object?s opacity (p<0,05). It was concluded that coin Rp. 100,- as added aluminium filter can increase the radiographic detail of interdental object with instant film compare with the intraoral image without any added filtration.

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Dewasa ini, penggunaan film instan menjadi pilihan alternatif dalam pemeriksaan penunjang radiografis di bidang kedokteran gigi. Deteksi dini perubahan jaringan periodonsium pada radiograf konvensional sering memberikan kesulitan bagi dokter gigi, terutama jaringan lunak/gingiva yang mempunyai densitas minimal. Gambaran detil jaringan lunak dapat diraih dengan cara menurunkan kekontrasan radiograf. Penggunaan filter aluminium tambahan dapat mempengaruhi kekontrasan radiograf. Penelitian ini bertujuan untuk melihat pengaruh uang logam seratus rupiah sebagai filter dalam meningkatkan detil gambaran radiografis obyek interdental model gigi pada foto intraoral dengan film instan Hanshin D-speed. Obyek penelitian adalah 60 buah radiograf, 30 tanpa menggunakan filter alumunium dan 30 radiograf menggunakan filter aluminium. Pemeriksaan detil dilakukan dengan cara mengukur panjang dimensi vertikal opasitas papila interdental menggunakan kaliper (milimeter). Data yang diperoleh adalah data numerik. Regio yang diperiksa adalah obyek interdental antara gigi molar 1 bawah kanan dengan gigi molar 2 bawah kanan. Hasil penelitian ini menunjukkan bahwa terdapat perbedaan rerata panjang dimensi vertikal opasitas obyek interdental (uji t tidak berpasangan, p<0,05). Dari penelitian ini dapat disimpulkan bahwa filter aluminium berupa uang logam Rp 100,- (seratus rupiah) terbukti dapat meningkatkan detil obyek interdental model gigi foto intraoral dengan film instan dibandingkan dengan foto tanpa menggunakan filter."

"Material yang sesuai dengan penghantar listrik yang baik harus mempunyai sifat konduktifitas dan kuat tarik yang baik. Tembaga merupakan material yang paling poluler untuk material penghantar listrik. Akan tetapi Tembaga mempunyai kuat tarik yang kurang bagus. Untuk memperbaiki kuat tarik Tembaga dilakukan dengan memadukan material yang lain. Sudah diketahui bahwa Tembaga yang mempunyai kuat tarik tinggi dapat diperoleh dengan memadukan Tembaga dengan logam refractory seperti Niobium, Vanadium dan lain - lain. Niobium merupakan material pemadu yang paling cocok karena mempunyai kuat tarik dan konduktifitas yang tinggi. Dari hasil perhitungan regresi linier variabel konduktifitas listrik dan kuat tarik dihasilkan koefisien regresi - 5,1228733 x 10-6 dan perhitungan korelasi - 1 dengan R 100 %.

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The suitable materials for electrical conductivity device should have high properties of conductivity and tensile strength. Copper is the very common material for its purpose. However, copper has relatively weak tensile strength. One promising approach to improving the strength of copper is to mix it with an alloying material. It is know that quite high strength copper can be produced by alloying copper with refractory metal such as niobium, vanadium, etc. Niobium is suitable alloying material because it's high strength and good in electrical conductivity. The result from the linear regression calculation of the electrical conductivity and tensile strength variable that coefficient regression is ' 5,1228733 x 10-6 and its correlation is ' 1 by R 100 %."

"Latar Belakang: Penelitian mengenai pengaruh pelebaran korona saluran akar terhadap tingkat ketepatan apex locator hanya sedikit. Tujuan: Membandingkan ketepatan lokasi foramen apikalis pada dua tipe apex locator dan menilai pengaruh pelebaran koronal saluran akar. Metode: Panjang kerja 16 gigi premolar satu mandibula diukur secara visual, menggunakan dua jenis apex locator saat sebelum dan setelah dilakukan pelebaran korona saluran akar. Hasil: Berbeda bermakna ketepatan pada tiap jenis apex locator setelah dilakukan pelebaran korona, namun tidak berbeda bermakna pada keduanya setelah pelebaran koronal saluran akar. Kesimpulan: pelebaran korona saluran akar meningkatkan ketepatan apex locator mengukur lokasi foramen apikalis.

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Background: Only a few studies on the effect of coronal preflaring to the accuracy of apex locator.

Objective: To compare the accuracy of two types of apex locators and evaluate the influence of coronal preflaring in them.

Method: working length of sixteen first mandibular bicuspids were measured visually, using two types apex locator at before and after coronal preflaring.

Result: statistically significant of two type apex locators at before and after coronal preflaring, no statistically significant at both types after coronal preflaring.

Conclusion: coronal preflaring will increase the accuracy of apex locator in locating the apical foramen."

"In 2016, the mandatory use of biodiesel as a substitute fuel by up to 20%,as introduced by the Indonesian Ministry of Energy and Mineral Resources,forced vehicle manufacturers to invent suitable engines that would acceptbiodiesel. The use of biodiesel in such a large proportion is highly risky,particularly due to the formation of deposits in the combustion chamberengines. The previous method of fuel droplets are placed on a hot plateapproach produces deposits are slightly different from those generated by areal engine, therefore to obtain realistic deposits it is necessary to modifythis method so temperatures as hot as those in a real engine. In this study,the potential deposit formation of biodiesel fuel was examined by conductingthe deposition process and the evaporation of fuel on a stainless-steel plate(SS), which was placed in a closed space. Deposit characterization was carried outon a hot plate using Scanning Electron Microscopy (SEM). The test results showeddifferences in the structures of the deposits produced by biodiesel and dieselfuel; fine structures were seen in the former, while those of the latter wererougher and more porous. Deposit results that are similar to what is seen in areal engine will be very helpful for knowing the patterns, structures, and mechanismof the formation of deposits in such an environment."

"Kewajiban penggunaan biodiesel sebesar 20 pada tahun 2016 oleh Kementerian ESDM memaksa pabrik kendaraan menyiapkan mesin yang cocok untuk bahan bakar biodiesel. Karena penggunaan biodiesel dengan prosentase besar >20 sangatlah beresiko, khususnya pembentukan deposit di ruang bakar mesin diesel. Riset awal dilakukan dengan membandingkan IBF dan BS50 dalam sisi pertumbuhan deposit, komposisi deposit, serta efek deposit terhadap kualitas kerja mesin. Riset dengan menggunakan mesin single silinder selama 200 jam menunjukan bahwa biodiesel menghasilkan deposit yang lebih banyak, akan tetapi belum menunjukkan penurunan performa yang signifikan. Dan untuk mengetahui pertumbuhan secara detail, metode droplet pada pelat panas digunakan pada bahan bakar biodiesel FAME dan Solar murni. Karena pembentukan deposit di mesin sangat komplek penggunaan metode droplet sangat membantu melihat lebih detail setiap faktor yang berperan dalam pertumbuhan deposit. Berdasarkan data riset faktor temperatur permukaan komponen memegang peran dominan dalam pertumbuhan deposit. Karakterisasi deposit pada plat dilakukan dengan menggunakan FTIR, SEM dan mikroskop elektron. Berdasarkan data SEM dan mikroskop electron struktur deposit tergantung dari suhu permukaan pelat. Semakin tinggi suhunya semakin banyak pori dan permukaan deposit cenderung kasar. Selain itu hasil analisa unsur pada deposit mampu menjadi finger print kondisi mesin. Hasil FTIR deposit biodiesel sawit menunjukkan adanya kemiripan gugus fungsi bila dibandingkan dengan deposit yang terbentuk pada injektor dari data referensi. Variasi aditif antioksidan pada biodiesel dilakukan untuk mengetahui efek yang ditimbulkan terhadap pembentukan deposit.

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The Mandatory from the Indonesian Ministry of Energy and Natural Resources about an implementation to blend of 20 biodiesel in diesel fuel forced the vehicle manufacturers to prepare suitable mesins for biodiesel fuel. Due to the use of biodiesel with a large percentage more than 20 is extremely risky, particularly the formation of deposits inside the combustion chamber of diesel mesins. The initial research was done by comparing the IBF and BS50 in the growth of the deposit, the composition of the deposit, as well as the effect of a deposit to the performance of mesin.

Research using single cylinder mesin during 200 hours showed that biodiesel generates a lot of deposit, but has not shown a decrease in the performance.The droplets on hot plate method used to know the growth of deposit in detail, on biodiesel fuel FAME and pure diesel fuel. Due to the complexity of deposits formation on the mesin, the use of the droplets method is very helpful to see more detail each of the faktors that play a role in the growth of the deposit.

Based on this research, the surface temperature of component became dominant faktor in the deposits growth. Characterization of deposits on the plate is performed using FTIR, SEM and electron microscopy. The result of elemental analysis on the deposit is able to become finger print to mesin condition. FTIR results of palm biodiesel deposits indicate a similarity of functional groups if compared with deposits formed on injektors. Variations of antioxidant aditifs were carried out to determine the effects of deposition. "

"Pada proses pengembangan produk, produsen menerapkan berbagai cara agar produk yang dihasilkannya bisa menjawab kebutuhan pasar, dengan pergeseran tren konsumen yang menginginkan produk yang lebih spesifik, para engineer mulai mengembangkan metode terbaru untuk memproduksi suatu benda yang efisien, baik secara biaya maupun waktu, Virtual Manufacturing mampu mengakomodasi hal tersebut dengan baik, produsen dapat meminimalkan atau menghilangkan sama sekali fase pembuatan prototype secara fisik, yang berdampak pada efisiensi biaya maupun waktu, saat ini proses Virtual Manufacturing lebih banyak menggunakan Virtual Reality, dan hal ini berdampak pada proses yang lebih artificial, penelitian ini ditujukan untuk menggabungkan metode Virtual Manufacturing dengan menggunakan kamera dan sensor berbasis Electromyogram untuk mengukur tingkat kontraksi tangan ketika melakukan proses Virtual Manufacturing. Sehingga fokus pada skripsi ini adalah bagaimana cara mengetahui karakter kontraksi otot biceps brachii pada beberapa kondisi, yang kedepannya akan dimanfaatkan dalam proses Virtual Manufacturing.

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In term of product development, many manufacturer seeking for the best solution to ensure their product is what the customers really looking for. Manufacturer have to be able to know the trend, and accomodate the spesific needs of the customer, but after that they also have to minimize the cost and time to make a product. Virtual Manufacturing is one of the method that can achieve that requirement, because it rsquo s really efficient, and many big manufacturer in the world have implemented this method. Basicly, Virtual Manufacturing tend to use Virtual Reality to showing the object. But in this thesis, author mainly use camera for projecting the virtual image and electromyogram sensor to calculate muscle contraction during Virtual Manufacturing process. Author made some parameter from different people to getting know the characteristics from Biceps Brachii Muscle. In the future researcher really hope that Electromyogram based Virtual Manufacturing can be able used by Manufacturer."

"In 2016, the mandatory use of biodiesel as a substitute fuel by up to 20%, as introduced by the Indonesian Ministry of Energy and Mineral Resources, forced vehicle manufacturers to invent suitable engines that would accept biodiesel. The use of biodiesel in such a large proportion is highly risky, particularly due to the formation of deposits in the combustion chamber engines. The previous method of fuel droplets are placed on a hot plate approach produces deposits are slightly different from those generated by a real engine, therefore to obtain realistic deposits it is necessary to modify this method so temperatures as hot as those in a real engine. In this study, the potential deposit formation of biodiesel fuel was examined by conducting the deposition process and the evaporation of fuel on a stainless-steel plate (SS), which was placed in a closed space. Deposit characterization was carried out on a hot plate using Scanning Electron Microscopy (SEM). The test results showed differences in the structures of the deposits produced by biodiesel and diesel fuel; fine structures were seen in the former, while those of the latter were rougher and more porous. Deposit results that are similar to what is seen in a real engine will be very helpful for knowing the patterns, structures, and mechanism of the formation of deposits in such an environment."