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"In this work the formation of Fe-Cr microalloy by ultrasonic irradiation at a frequency of 20 kHz is presented. Two sample series were produced with different ultrasonic irradiation procedures. For the first sample, Fe and Cr powder were each separately brought into the ultrasonic device before they were mixed in 7:1 weight ratio and then together retreated using the ultrasonic method. Secondly, Fe and Cr powder with same weight ratio were mixed and directly ultrasonically irradiated. During the ultrasonic irradiation process both samples were put in a toluene solution of 99%. The formation of the Fe-Cr microstructure in conjunction with ultrasonication time were investigated by using Scanning Electron Microscopy (SEM ), X-rayDiffraction (XRD) and Transmission Electron Microscopy (TEM). After 40 hours of ultrasonicirradiation the particle sizes of the Fe powder of the first samples became significantly smaller; some particles were also fused together. However, with the exception of smaller-sized particles no fused Cr powders can be found even after 63 hours of ultrasonic irradiation. After both experiments Fe and Cr were mixed and again ultrasonically irradiated for 20 hours. Someparticles indicated as Fe-Cr alloys containing 24.34 wt.% Fe and 67.43 wt.% Cr were observed.In the sample produced from the second procedure in which both Fe and Cr powders were irradiated together by an ultrasonic method for 50 hours, some powder particles formed a Fe-Cr microalloy with the composition of 96.27 wt.% Fe and 3.73 wt.% Cr. The XRD analysis revealed that the Fe-Cr alloy from the first samples has a BCC structure with a mass fraction of Fe:Cr:Fe-Cr which is equal to 0.836:0.0294:0.135, while the mass fraction of the Fe-Cr alloy from the second sample series is equal to 0.736:0.0808:0.183, respectively. Analysis of the TEM selected area diffraction patterns (SAED) confirmed that the Fe-Cr microalloy occured originaly from the precursor Fe and Cr particles of size smaller than 2 µm. The Fe-Cr microalloy has been successfully synthesized by using an ultrasonic process."

"ABSTRAKBaja ODS (Oxide Dispersion Strengthened) merupakan paduan dengan ketahanan temperatur dan korosi yang baik. Penggunaan metode iradiasi ultrasonik di dalam larutan toluene merupakan metode baru yang dapat memberikan keuntungan berupa ukuran butir yang halus, dapat membentuk microalloying di dalam serbuk, dan dapat meminimalisasi pembentukan fasa oksida. Penelitian ini mempelajari tentang pengaruh amplitudo terhadap reduksi ukuran partikel, homogenitas serbuk, dan pembentukan microalloying Fe-Cr pada preparasi serbuk Fe-15Cr-0.5Y2O3. Serbuk dibagi menjadi 4 sampel dengan perlakuan pencampuran mortar (sampel A), iradiasi ultrasonik dengan amplitudo 40% (sampel B), 50% (sampel C), dan 60% (sampel D) yang kemudian dikarakterisasi menggunakan SEM, EDS, dan XRD. Hasil dari penelitian ini adalah peningkatan amplitudo akan menurunkan ukuran butir dengan nilai sampel B>sampel C>sampel D adalah 4.63 μm>3.44 μm>3.09 μm. Sampel C menghasilkan partikel Fe-Cr sementara sampel B dan D terbentuk partikel paduan Fe-Cr-Y2O3. Nilai komposisi Fe-Cr terbesar dicapai pada amplitudo 40% dengan nilai sampel A:sampel B:sampel C: sampel D adalah 0.00%:20.5%:10.06%:5.2% tanpa pembentukan oksida dengan ukuran crystallite Fe-Cr sampel B:sampel C:sampel D berukuran 16.79 nm:30.13 nm: 55.69 nm. Nilai lattice strain sampel B:sampel C: sampel D adalah 0.0055:0.0030:0.0016.

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ABSTRACTODS Steel (Oxide Dispersion Strengthened) is an alloy with good corrosion and high temperature resistance. The utilization of ultrasonic irradiation method in toluene solution is a new method giving benefits like producing fine grain-size, forming micro-alloying on powder, and minimizing the oxide phase formation. This research investigates the influence of amplitude on the reduction of the particle size, the homogeneity of the powder, and the formation of Fe-Cr microalloying on Fe-15Cr-0.5Y2O3 powder preparation. The powder was divided into 4 samples with various treatments such as mortar mixing (sample A) and ultrasonic irradiation with an amplitude of 40% (sample B), 50% (sample C) and 60% (sample D). After that, each sample was characterized by SEM, EDS and XRD. This research shows that increasing the amplitude will decrease the grain size with the value of sample B> sample C> sample D is 4.63 μm>μm 3:44> 3:09 μm. Sample C produced Fe-Cr particles meanwhile samples B and D formed Fe-Cr-Y2O3 alloy particle. The highest composition value of Fe-Cr is reached on the amplitude of 40% to the composition value of sample A: sample B: sample C: sample D is 0.00%: 20.5%: 10:06%: 5.2% without the oxide formation. The size of crystalline Fe-Cr sample B: sample C : sample D size of 16.79 nm: 30.13 nm: 55.69 nm. The lattice strain value of the sample B: the sample C: sample D was 0.0055: 0.0030: 0.0016.;"

"ABSTRAKPercampuran serbuk baja ODS Oxide Dispersion Strengthened pada umumnya menggunakan metode mekanik dengan ball mill, namun selama pembuatannya disertai pembentukan oksida. Percampuran serbuk dengan metode iradiasi ultrasonik merupakan metode baru yang memberikan keuntungan berupa membentuk microalloying partikel dan meminimalisasi pembentukan fasa oksida. Penelitian ini mempelajari tentang pengaruh amplitudo 20, 30, 40 dan waktu perlakuan 20jam, 30 jam terhadap reduksi ukuran partikel dan pembentukan microalloying Fe-Cr. Serbuk dibagi menjadi 7 sampel dengan sampel A perlakuan pencampuran mortar, iradiasi ultrasonik sampel B1 A:20, t: 20 jam, sampel B2 A:30, t:20 jam, sampel B3 A:40, t:20 jam, sampel C1 A:20, t:30 jam, sampel C2 A:40, t:30 jam, dan sampel C3 A:40, t:30 jam yang kemudian dikarakterisasi menggunakan SEM, EDS, dan XRD. Hasil penelitian ini adalah pada iradiasi ultrasonik selama 20 jam menghasilkan ukuran partikel sampel B1>sampel B2>sampel B3 adalah 5.326 m>4.769 m>4.563 m. Sedangkan pada iradiasi ultrasonik selama 30 jam menghasilkan ukuran partikel sampel C1>sampel C2>sampel C3 adalah 4.605 m>3.719 m>3.608 m. Komposisi Fe-Cr yang terbentuk adalah sampel A: sampel B1: sampel B2: sampel B3:sampel C1:sampel C2: C3 adalah 0:48.85:26.07:2478:89:81.94:42.98. Hasil tersebut menunjukan bahwa semakin besar amplitudo, microalloying Fe-Cr yang terbentuk menjadi semakin rendah, penambahan waktu perlakuan justru meningkatkan presentase Fe-Cr yang terbentuk. Pada ultrasonik selama 20 jam, nilai crystallite size Fe-Cr sampel B1>sampel B2>sampel B3 adalah 292.72 nm>246.76 nm>184.77 nm dan nilai microstrains Fe-Cr sampel B1184.34 nm dan nilai microstrains Fe-Cr sampel C1< sampel C2.

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ABSTRACTThe mixing of ODS Oxide Dispersion Strengthened powder generally uses mechanical method with ball mill, but during its manufacture with oxide formation. Powder mixing with ultrasonic irradiation method is a new method that provides the advantage of forming microalloying particles and minimizing the formation of the oxide phase. This study studied the effect of amplitude 20, 30, 40 and treatment time 20h, 30h on particle size reduction and formation of Fe Cr microalloying. The powder was divided into 7 samples with sample A mortar mixing treatment, ultrasonic irradiation of sample B1 A 20, t 20 hours, sample B2 A 30, t 20 hours, sample B3 A 40, T 20 hours, sample C1 A 20, t 30 hours, C2 sample A 40, t 30 hours, and C3 sample A 40, t 30 hours Which is then characterized using SEM, EDS, and XRD. The results of this study were on ultrasonic irradiation for 20 hours yielding sample particle size B1 sample B2 B3 sample was 5,326 m 4,769 m 4,563 m. While on ultrasonic irradiation for 30 hours resulted in particle size of sample C1 C2 sample C3 sample is 4,605 m 3,719 m 3,608 m. The composition of Fe Cr formed is sample A sample B1 sample B2 sample B3 sample C1 sample C2 C3 is 0 48.85 26.07 24.78 89 81.94 42.98. These results show that the greater the amplitude, the lower the Fe Cr microalloying that is formed, the added time of treatment actually increases the Fe Cr percentage that is formed. At ultrasonic for 20 hours, the crystallite size of Fe Cr sample B1 sample B2 B3 sample is 292.72 nm 246.76 nm 184.77 nm and the Fe Cr microstrains value of sample B1 198.02 nm 184.34 nm and the Fe Cr microstrains value of sample C1."

"ABSTRACTIndonesia pernah merajai industri kayu dunia pada periode 1980 hingga 1995, saat itu perolehan devisa untuk industri ini mencapai US 6 milyar hingga US 7 milyar pertahun, serta memberikan kontribusi ekonomi terhadap pendapatan negara sangat besar. Industri kayu juga menciptakan peluang usaha maupun penyerapan tenaga kerja yang tinggi. Produk kayu dari Indonesia seperti kayu lapis, kayu olahan, pulp and paper serta industri mabel berjaya di pasar dunia. Dengan banyaknya lembaran kayu lapis yang akan diproduksi setiap harinya maka dibutuhkan alat penghitung otomatis yang dapat menghitung kayu lapis yang akan diproses pada mesin glue spreader dengan tantangan bahwa kayu lapis yang akan diproses tidak selalu memiliki bentuk yang utuh atau dengan kata lain terbelah menjadi dua bagian. Salah satu kemajuan teknologi yang dapat dimanfaatkan untuk membuat alat penghitung otomatis adalah dengan memanfaatkan sensor ultrasonik dan juga mikrokontroller Arduino. Pembuatan alat ini akan menggunakan 3 buah sensor ultrasonik dan mikrokontroller Arduino. Akan terdapat 4 kondisi pada pengujian alat ini yang mana masing-masing kondisi dirancang agar sesuai dengan tantangan bahwa kondisi dari kayu lapis tidak selalu dalam keadaan utuh. Pengujian alat akan dilakukan sebanyak 3 kali dan setiap pengujian alat dilakukan dengan melakukan pengetesan penghitungan kayu lapis sebanyak 50 kali, selain itu pengujian alat akan melakukan variasi pada jarak horizontal, jarak vertikal, delay pendeteksian sensor. Hasil dari pengujian alat tersebut didapati bahwa kondisi yang paling baik untuk variasi jarak horizontal adalah pada jark 13 cm, untuk variasi jarak vertikal adalah pada jarak 25 cm, dan untuk variasi delay adalah pada delay 300 ms.Indonesia pernah merajai industri kayu dunia pada periode 1980 hingga 1995, saat itu perolehan devisa untuk industri ini mencapai US 6 milyar hingga US 7 milyar pertahun, serta memberikan kontribusi ekonomi terhadap pendapatan negara sangat besar. Industri kayu juga menciptakan peluang usaha maupun penyerapan tenaga kerja yang tinggi. Produk kayu dari Indonesia seperti kayu lapis, kayu olahan, pulp and paper serta industri mabel berjaya di pasar dunia. Dengan banyaknya lembaran kayu lapis yang akan diproduksi setiap harinya maka dibutuhkan alat penghitung otomatis yang dapat menghitung kayu lapis yang akan diproses pada mesin glue spreader dengan tantangan bahwa kayu lapis yang akan diproses tidak selalu memiliki bentuk yang utuh atau dengan kata lain terbelah menjadi dua bagian. Salah satu kemajuan teknologi yang dapat dimanfaatkan untuk membuat alat penghitung otomatis adalah dengan memanfaatkan sensor ultrasonik dan juga mikrokontroller Arduino. Pembuatan alat ini akan menggunakan 3 buah sensor ultrasonik dan mikrokontroller Arduino. Akan terdapat 4 kondisi pada pengujian alat ini yang mana masing-masing kondisi dirancang agar sesuai dengan tantangan bahwa kondisi dari kayu lapis tidak selalu dalam keadaan utuh. Pengujian alat akan dilakukan sebanyak 3 kali dan setiap pengujian alat dilakukan dengan melakukan pengetesan penghitungan kayu lapis sebanyak 50 kali, selain itu pengujian alat akan melakukan variasi pada jarak horizontal, jarak vertikal, delay pendeteksian sensor. Hasil dari pengujian alat tersebut didapati bahwa kondisi yang paling baik untuk variasi jarak horizontal adalah pada jark 13 cm, untuk variasi jarak vertikal adalah pada jarak 25 cm, dan untuk variasi delay adalah pada delay 300 ms.

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ABSTRACTIndonesia once dominated the world wood industry in the period 1980 to 1995, at that time the acquisition of foreign exchange for this industry reached US 6 billion to US 7 billion per year, and contributed economically to the income of the country is very large. The timber industry also creates business opportunities and high employment. Wood products from Indonesia such as plywood, processed wood, pulp and paper and mabel industries triumph in the world market. With so many plywood sheets that will be produced every day, an automatic counters is needed that can calculate the plywood to be processed on a glue spreader machine with the challenge that the plywood to be processed does not always have the full shape or in other words split into two parts. One of the technological advances that can be utilized to create automated counters is by utilizing ultrasonic sensors as well as Arduino microcontrollers. Making this tool will use 3 pieces ultrasonic sensors and Arduino microcontroller. There will be 4 conditions under which this tool is tested in which each condition is designed to conform to the challenge that the condition of the plywood is not always intact. Testing tool will be done 3 times and every testing tool done by testing ply counting counted 50 times, besides testing tool will do variation on horizontal distance, vertical distance, sensor detection delay. The result of the tool test shows that the best condition for horizontal distance variation is at 13 cm distance, for variation of vertical distance is at 25 cm distance, and for delay variation is at 300 ms delay."

"[ABSTRAKFe-Cr adalah paduan yang memiliki ketahanan temperatur tinggi danpotensial digunakan sebagai interkonektor pada sel bakar (SOFC=solid oxide fuelcell). Sintesis paduan Fe-Cr terus dikembangkan untuk mendapatkan metode yangefektif, dan efisien. Metode sintesis paduan Fe-Cr yang ada sekarang ini adalahmetode peleburan, metalurgi serbuk ataupun metode pemaduan mekanik. Metodemetodetersebut memiliki kelemahan misalnya paduan yang tidak homogen,terdapat oksida, proses panjang dan membutuhkan waktu lama. Untukmeminimumkan permasalahan ini, adalah penting untuk menghasilkan paduanmikro Fe-Cr yang memiliki kestabilan fasa dan sifat mekanis baik. Metodeultrasonik dapat dimanfaatkan untuk sintesis paduan mikro homogen melaluipenggunaan gelombang suara ultrasonik. Gelombang suara ultrasonikmenghasilkan gelembung-gelembung kavitasi, setiap runtuhan kavitasi dapatdianggap sebagai reaktor mikro yang mampu menghasilkan temperatur sekitar4737 oC dan tekanan sekitar 1000 atm dan yang terbentuk dengan sangat cepat,serta menghasilkan gelombang kejut. Dengan demikian metode ultrasonik dapatdimanfaatkan dalam pembuatan paduan mikro Fe-Cr yang homogen serta tanpaoksida dan diharapkan bisa mengatasi kelemahan metode pembuatan paduanberbasis Fe saat ini. Pada penelitian ini telah dilakukan sintesis paduan mikro Fe-Cr dengan metode ultrasonik pada frekuensi 20 kHz dalam cairan toluene.Tahapan yang telah dilakukan adalah perlakuan ultrasonik sebagai variasi waktuterhadap partikel prekursor (Fe, Cr), kemudian terhadap campuran partikelprecursor untuk mendapatkan paduan mikro Fe-Cr. Kemudian dilakukanpembuatan bongkah paduan Fe-Cr dari partikel hasil perlakuan ultrasonik melaluikompaksi tanpa lubrikan dan sintering dalam kapsul kaca kuarsa. Karakterisasiyang dilakukan adalah menggunakan Scanning Electron Microscopy (SEM)terhadap partikel precursor hasil rekayasa ultrasonic. Untuk partikel campuranprekursor Fe-Cr hasil perlakuan ultrasonik karakterisasi dilakukan menggunakanSEM-EDS (Energy Dispersive Spectroscopy), X-Ray Diffraction (XRD) disertaianalisis dengan metode Rietveld, Transmission Electron Microscopy-SelectedArea Electron Diffraction (TEM-SAED). Untuk bongkah Fe-Cr hasil konsolidasidengan menggunakan SEM-EDS, XRD disertai analisis dengan metode Rietveld,pengukuran densitas sebenarnya, pengujian kekerasan Vickers. Efek perlakuanultrasonik terhadap partikel Fe adalah pengurangan ukuran, penyatuan, danaglomerasi. Setelah perlakuan ultrasonik 40 jam terjadi peningkatan ukuranpartikel Fe (>2μm). Terhadap partikel Cr memberikan efek erosi permukaan,pengurangan ukuran dan pemecahan partikel aglomerasi. Partikel Cr aglomerasiterurai sepenuhnya menjadi partikel Cr kecil (< 2 m) setelah 63 jam. Terhadapcampuran partikel Fe dan Cr dapat menyatukan partikel kohesif (Fe-Fe, Cr-Cr)dan adhesif (Fe-Cr), terbentuk paduan mikro Fe-Cr seutuhnya (setelah 20 jam)ataupun paduan mikro Fe-Cr sebagian (setelah 50 jam). Pembentukan paduanmikro Fe-Cr diawali pada ukuran partikel Fe ataupun Cr < 2m. Bongkah paduan mikro Fe-Cr yang diperoleh adalah homogen dan tanpa oksida, dengankarakteristik densitas melalui sintering dua tahap yaitu tipe O = 8.655 gr/cm3, tipeB=8.179 gr/cm3, dan tipe A=8.196 gr/cm3, dan melalui proses sintering satu tahaptipe O = 7.678 gr/cm3, tipe B=7.587gr/cm3, dan tipe A=7.092 gr/cm3. Kekerasanbongkah Fe-Cr terbesar melalui sintering satu tahap yaitu 88 VHN adalah tipe B,sementara terbesar dua tahap yaitu 81 VHN adalah tipe A. Proses perlakuanultrasonik memberikan dampak positif baik dari sisi waktu proses maupunkualitas hasil paduan Fe-Cr. Dengan demikian metode ultrasonik bisa diandalkansebagai alternatif dalam pembuatan paduan berbasis Fe untuk mengatasi kendalahomogenisasi dan oksidasi yang dihadapi pada metode saat ini.;

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ABSTRACTFe-Cr alloys have the potential for use as an interconnection material forsolid oxide fuel cell (SOFC) due to its being resistance to high temperatures.Synthesis methods of Fe-Cr alloy continue to be developed in order to obtain amethod that is both effective and efficient. Presently, the synthesis of Fe-Cr alloysinclude the casting, the powder metallurgy, and the mechanical alloying method.These methods have several drawbacks such as inhomogeneity in the resultingproducts, oxidation, and require a very time-consuming process to accomplish. Inorder to minimize this problem, it is important to produce Fe-Cr microalloys. Fe-Cr microalloys exhibit phase stability and good mechanical properties. Ultrasonicmethods can be used in the synthesis of homogeneous microalloys by employingthe ultrasonic sound waves. Ultrasonic sound waves will generate cavitationbubbles. Any cavitation collapse can be considered as a micro reactor in which atemperature of about 4737 oC and a pressure of about 1000 atm a very rapidlycreated, thereby generating a shock wave. Thus, the ultrasonic method can beused in producing homogeneous and free-oxide Fe-Cr microalloys and can beexpected to overcome the limitations imposed by the current methods. In thiswork the formation of Fe-Cr microalloys by ultrasonic treatment at a frequency of20 kHz in toluene liquid is presented. In the synthesis procedure, the proceduresteps followed were: (1) the treatment of precursor particles (Fe, Cr) throughultrasonic method with a time-variation, followed by (2) the same time-varyingultrasonic treatment on the admixture of these specially prepared precursorparticles in order to obtain the Fe-Cr microalloys, and (3) finally, the lubricantlesscompaction method was employed on these precursor particles admixturefollowed by sintering process inside quartz tubes to obtain a bulk of Fe-Cr alloy.Observations of the specially prepared precursor particles using ultrasonictechnique were carried out by scanning electron microscopy (SEM) method.Observation of the precursor mixture of Fe-Cr particles mixture treatedultrasonically was performed using a SEM-EDS (energy-dispersive spectroscopy)apparatus, a X-Ray diffractometer and accompanied by the Rietveld analysismethod, and transmission electron microscopy (TEM)-selected area electrondiffraction (SAED) apparatus. The bulk of Fe-Cr alloy were observed using SEMEDS,XRD accompanied by analysis by the Rietveld method, true densitymeasurement, and Vickers microhardness testing. Ultrasonic treatment has causedFe particles to form agglomerations, an interparticles neck formation, and a fusingamong the particles. The size of the Fe particles increased (>2μm) after 40 hourstreatment. The agglomerated Cr particles experienced fragmentation, surfaceerosion, and reduction of particle size. The agglometrated Cr particles fullydisintegrated into Cr microparticles (<2μm) after 63 hours treatment. The mixtureof Fe-Cr forming cohesive (Fe-Fe, Cr-Cr) and adhesive (Fe-Cr) particles, formingcompletely (after ultrasonic treatment for 20 hours) and partially (after ultrasonictreatment for 50 hours) Fe-Cr microalloys. The complete formation of Fe-Cr microalloy was possible with an equal particle size of the precursor Fe and Cr(approximately <2 μm). The bulk of Fe-Cr alloy results are homogenous andoxide-free. For two-step sintering, its density (in gr/cm3 unit) is 8.655 for type O,is 8.179 for type B, and is 8.196 for type A, and for one-step sintering its densityis 7.678 for type O, is 7.587 for type B, and is 7.092 for type A. The greatestmicrohardness number of 88 VHN is of type B (one-step sintering), and of 81VHN is of type A (two-step sintering). The ultrasonic treatment process has apositive impact, with respect to both of quality and time-consumption to finish theFe-Cr alloying process. Therefore the ultrasonic method can be relied upon as analternative method in the production of Fe-based alloys to solve problems inhomogenization and oxidation encountered in current methods;Fe-Cr alloys have the potential for use as an interconnection material forsolid oxide fuel cell (SOFC) due to its being resistance to high temperatures.Synthesis methods of Fe-Cr alloy continue to be developed in order to obtain amethod that is both effective and efficient. Presently, the synthesis of Fe-Cr alloysinclude the casting, the powder metallurgy, and the mechanical alloying method.These methods have several drawbacks such as inhomogeneity in the resultingproducts, oxidation, and require a very time-consuming process to accomplish. Inorder to minimize this problem, it is important to produce Fe-Cr microalloys. Fe-Cr microalloys exhibit phase stability and good mechanical properties. Ultrasonicmethods can be used in the synthesis of homogeneous microalloys by employingthe ultrasonic sound waves. Ultrasonic sound waves will generate cavitationbubbles. Any cavitation collapse can be considered as a micro reactor in which atemperature of about 4737 oC and a pressure of about 1000 atm a very rapidlycreated, thereby generating a shock wave. Thus, the ultrasonic method can beused in producing homogeneous and free-oxide Fe-Cr microalloys and can beexpected to overcome the limitations imposed by the current methods. In thiswork the formation of Fe-Cr microalloys by ultrasonic treatment at a frequency of20 kHz in toluene liquid is presented. In the synthesis procedure, the proceduresteps followed were: (1) the treatment of precursor particles (Fe, Cr) throughultrasonic method with a time-variation, followed by (2) the same time-varyingultrasonic treatment on the admixture of these specially prepared precursorparticles in order to obtain the Fe-Cr microalloys, and (3) finally, the lubricantlesscompaction method was employed on these precursor particles admixturefollowed by sintering process inside quartz tubes to obtain a bulk of Fe-Cr alloy.Observations of the specially prepared precursor particles using ultrasonictechnique were carried out by scanning electron microscopy (SEM) method.Observation of the precursor mixture of Fe-Cr particles mixture treatedultrasonically was performed using a SEM-EDS (energy-dispersive spectroscopy)apparatus, a X-Ray diffractometer and accompanied by the Rietveld analysismethod, and transmission electron microscopy (TEM)-selected area electrondiffraction (SAED) apparatus. The bulk of Fe-Cr alloy were observed using SEMEDS,XRD accompanied by analysis by the Rietveld method, true densitymeasurement, and Vickers microhardness testing. Ultrasonic treatment has causedFe particles to form agglomerations, an interparticles neck formation, and a fusingamong the particles. The size of the Fe particles increased (>2μm) after 40 hourstreatment. The agglomerated Cr particles experienced fragmentation, surfaceerosion, and reduction of particle size. The agglometrated Cr particles fullydisintegrated into Cr microparticles (<2μm) after 63 hours treatment. The mixtureof Fe-Cr forming cohesive (Fe-Fe, Cr-Cr) and adhesive (Fe-Cr) particles, formingcompletely (after ultrasonic treatment for 20 hours) and partially (after ultrasonictreatment for 50 hours) Fe-Cr microalloys. The complete formation of Fe-Cr microalloy was possible with an equal particle size of the precursor Fe and Cr(approximately <2 μm). The bulk of Fe-Cr alloy results are homogenous andoxide-free. For two-step sintering, its density (in gr/cm3 unit) is 8.655 for type O,is 8.179 for type B, and is 8.196 for type A, and for one-step sintering its densityis 7.678 for type O, is 7.587 for type B, and is 7.092 for type A. The greatestmicrohardness number of 88 VHN is of type B (one-step sintering), and of 81VHN is of type A (two-step sintering). The ultrasonic treatment process has apositive impact, with respect to both of quality and time-consumption to finish theFe-Cr alloying process. Therefore the ultrasonic method can be relied upon as analternative method in the production of Fe-based alloys to solve problems inhomogenization and oxidation encountered in current methods, Fe-Cr alloys have the potential for use as an interconnection material forsolid oxide fuel cell (SOFC) due to its being resistance to high temperatures.Synthesis methods of Fe-Cr alloy continue to be developed in order to obtain amethod that is both effective and efficient. Presently, the synthesis of Fe-Cr alloysinclude the casting, the powder metallurgy, and the mechanical alloying method.These methods have several drawbacks such as inhomogeneity in the resultingproducts, oxidation, and require a very time-consuming process to accomplish. Inorder to minimize this problem, it is important to produce Fe-Cr microalloys. Fe-Cr microalloys exhibit phase stability and good mechanical properties. Ultrasonicmethods can be used in the synthesis of homogeneous microalloys by employingthe ultrasonic sound waves. Ultrasonic sound waves will generate cavitationbubbles. Any cavitation collapse can be considered as a micro reactor in which atemperature of about 4737 oC and a pressure of about 1000 atm a very rapidlycreated, thereby generating a shock wave. Thus, the ultrasonic method can beused in producing homogeneous and free-oxide Fe-Cr microalloys and can beexpected to overcome the limitations imposed by the current methods. In thiswork the formation of Fe-Cr microalloys by ultrasonic treatment at a frequency of20 kHz in toluene liquid is presented. In the synthesis procedure, the proceduresteps followed were: (1) the treatment of precursor particles (Fe, Cr) throughultrasonic method with a time-variation, followed by (2) the same time-varyingultrasonic treatment on the admixture of these specially prepared precursorparticles in order to obtain the Fe-Cr microalloys, and (3) finally, the lubricantlesscompaction method was employed on these precursor particles admixturefollowed by sintering process inside quartz tubes to obtain a bulk of Fe-Cr alloy.Observations of the specially prepared precursor particles using ultrasonictechnique were carried out by scanning electron microscopy (SEM) method.Observation of the precursor mixture of Fe-Cr particles mixture treatedultrasonically was performed using a SEM-EDS (energy-dispersive spectroscopy)apparatus, a X-Ray diffractometer and accompanied by the Rietveld analysismethod, and transmission electron microscopy (TEM)-selected area electrondiffraction (SAED) apparatus. The bulk of Fe-Cr alloy were observed using SEMEDS,XRD accompanied by analysis by the Rietveld method, true densitymeasurement, and Vickers microhardness testing. Ultrasonic treatment has causedFe particles to form agglomerations, an interparticles neck formation, and a fusingamong the particles. The size of the Fe particles increased (>2μm) after 40 hourstreatment. The agglomerated Cr particles experienced fragmentation, surfaceerosion, and reduction of particle size. The agglometrated Cr particles fullydisintegrated into Cr microparticles (<2μm) after 63 hours treatment. The mixtureof Fe-Cr forming cohesive (Fe-Fe, Cr-Cr) and adhesive (Fe-Cr) particles, formingcompletely (after ultrasonic treatment for 20 hours) and partially (after ultrasonictreatment for 50 hours) Fe-Cr microalloys. The complete formation of Fe-Cr microalloy was possible with an equal particle size of the precursor Fe and Cr(approximately <2 μm). The bulk of Fe-Cr alloy results are homogenous andoxide-free. For two-step sintering, its density (in gr/cm3 unit) is 8.655 for type O,is 8.179 for type B, and is 8.196 for type A, and for one-step sintering its densityis 7.678 for type O, is 7.587 for type B, and is 7.092 for type A. The greatestmicrohardness number of 88 VHN is of type B (one-step sintering), and of 81VHN is of type A (two-step sintering). The ultrasonic treatment process has apositive impact, with respect to both of quality and time-consumption to finish theFe-Cr alloying process. Therefore the ultrasonic method can be relied upon as analternative method in the production of Fe-based alloys to solve problems inhomogenization and oxidation encountered in current methods]"

"Dengan berjalannya waktu, permintaan akan penggunaan implan pada tulang semakin meningkat, hal ini juga beriringan dengan pengembangan efisiensinya dengan mengurangi jumlah tindakan operasi untuk menanam dan melepas implan miniplate. Pengunaan bahan magnesium yang dapat terurai secara biologis menjadi efisiensi dengan tidak perlunya tindakan operasi pelepasannya, Akan tetapi produksi miniplate berbahan magnesium AZ31B secara microforming tidak dapat diproduksi dengan baik karena sifat fisik pada temperatur ruangan dan skala mikro pada produk yang ingin dicapai. Oleh karena itu digunakan getaran ultrasonik untuk meningkatkan kualitas produksi miniplate magnesium. Dalam produksinya dari lembaran berbentuk persegi panjang hingga bentuk akhirnya, memerlukan perancangan tool dalam ukuran mikro yang diintegrasi dengan sistem ultrasonik dan penyesuaian terhadap desain miniplate. Proses microforming yang terjadi adalah blanking, punching, dan stamping. Validasi terhadap rancangan yang telah dibuat adalah dengan simulasi-simulasi yang paling mendekati kerja sebenarnya. Hasil yang diharapkan adalah desain secara lengkap tool yang dirancang agar menghasilkan produk akhir dengan kualitas yang diinginkan dengan bantuan getaran ultrasonik yang tervalidasi oleh simulasi, dimana diperkirakan adanya perbedaan antara tanpa dan dengan penggunaan Ultrasonic Vibration Assisted Microforming (UVAM), yaitu pada grafik stress dimana terjadi penurunan 100 MPa untuk punching dan 150 MPa untuk stamping.

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As time goes by, the demand for the use of bone implants is increasing. This is also accompanied by the development of its efficiency by reducing the number of operations for implanting and removing miniplate implants. The use of magnesium which is biodegradable is efficient without the need for a release operation. However, the production of miniplate made from magnesium AZ31B by microforming cannot be produced properly because of the physical properties in room temperature and the micro-scale of the product that needs to be achieved. Therefore, ultrasonic vibration is used to improve the production quality of magnesium miniplate. Its production from rectangular sheet to final shape requires designing tools in micro sizes integrated with ultrasonic systems and adjustments to the miniplate design. The microforming processes that occur are blanking, punching, and stamping. Validation of the design that has been made is by simulations that are closest to the actual work. The expected result is a complete design of the tool designed to produce the final product with the desired quality with the help of ultrasonic vibrations validated by the simulation, where it is estimated that there is a difference between with and without the use of Ultrasonic Vibration Assisted Microforming (UVAM), namely on the graph of the stress by decrement of 100 MPa on punching and 150 MPa for stamping."

"Minyak atsiri merupakan senyawa penting dalam bahan alam, yang memiliki banyak khasiat bagi kesehatan manusia. Minyak atsiri dapat diambil dari bahan alam dengan proses ekstraksi. Salah satu proses ekstraksi yang sedang menjadi tren penelitian adalah ekstraksi ultrasonik, yang dinilai memiliki banyak keunggulan, seperti kemudahan operasi, energi yang relatif rendah, dan operasi pada temperatur rendah yang dapat menjaga stabilitas senyawa biokimia dalam bunga telang. Salah satu kebaruan dalam penelitian ini adalah adanya penambahan mekanisme probe yang bergerak secara oksilasi, memungkinkan sumber gelombang ultrasonik menjadi dinamis. Selain itu, juga ditambahkan variasi intensitas ultrasonik sebagai parameter optimasi universal dalam ekstraksi ultrasonik. Adapun metode yang digunakan dalam analisis adalah metode kuantitatif dengan pengukuran data-data temperatur dan perhitungan fraksi massa minyak atsiri sebagai representasi kuantitas minyak atsiri, metode kualitatif dengan analisis visual perubahan warna emulsi dan distribusi temperatur terhadap waktu, serta metode analitik dengan perhitungan kinetik proses ekstraksi ultrasonik, untuk mengetahui nilai yield, yang direpresentasikan oleh kuantitas senyawa phenolic dengan perhitungan konstanta Peleg. Hasil penelitian menunjukkan bahwa, dengan penambahan probe oksilasi, dapat menyeragamkan distribusi temperatur dan ikatan antara pelarut dan senyawa biokimia dalam bahan alam, atau dengan kata lain, meningkatkan kualitas minyak atsiri yang dihasilkan. Di sisi lain, intensitas ultrasonik yang semakin tinggi dapat meningkatkan volume minyak atsiri yang dihasilkan, yang direpsentasikan fraksi massa minyak atsiri dan analisis kinetik yield terhadap waktu, serta meningkatkan laju ekstraksi yang terlihat dari analisis kinetik dan perubahan warna emulsi terhadap waktu. Hal ini disebabkan karena intensitas ultrasonik meningkatkan efek sonokemistri, kavitasi, turbulensi dan tegangan geser yang meningkatkan kuantitas dan laju ekstraksi. Hal penting yang harus diperhatikan dalam optimasi proses ekstraksi ultrasonik adalah turbulensi yang terlalu tinggi dapat menyebabkan agitasi dan temperatur yang terlalu tinggi dapat berpotensi merusak senyawa biokimia aktif dalam bunga telang.

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Essential oil is an important compound in natural substances, which has many benefits for human health. Essential oil can be produced from natural substances through the process of extraction. One of the trending extraction processes is ultrasonic extraction, which is considered to have many advantages, including, ease of operation, relatively low energi consumption, and capability to operate at low temperature which keep stabilitizing biochemical compounds inside natural substances, which in this research used butterfly pea flower (Clitoria Ternatea L). The novelty of this research was the application of a mechanism of osscilating moving probe, enabling ultrasonic wave source to be dynamic. Additionally, varieties of ultrasonic intensities was also applied as an universal parameter in optimizing the process of ultrasonic extraction. The methods used in the research were quantitative methods by measuring data of temperatures and calculating essential oil mass fraction, as representatives of essential oil quantity, qualitative methods by visual analysis of emulsion color evolution and temperature distribution through time, as well as analytical method by calculating the kinetics of ultrasonic extraction process, to determine yield, represented by phenolic compound quantity with Peleg’s constant calculation. The results of the research showed that oscilating probe addition could evenly distribute temperature and enhanced the bonds between solvent and biochemical compounds inside the natural substances, in other words, improving the quality of essential oil produced. On the other hand, a rise in ultrasonic intensities could increase essential oil volume produced, which was represented by essential oil mass fraction and kinetic analysis of yield through time, as well as increasing the extraction rate, as shown in kinetic analysis and emulsion color evolution. This was due to higher ultrasonic intensities enhanced sonochemistry effect, cavitation, turbulence and shear stress which increased essential oil quantity and the rate of extraction process. The important issues that needed to be considered in optimizing ultrasonic extraction process was over turbulence which could cause agitation and overhigh temperature which potentially could damage the active biochemical compounds inside butterlfy pea flower as a natural susbtance."

"ABSTRAKNavigasi otomatis pada drone sedang banyak dikembangkan dari berbagai macam jenis drone dan fungsi otomasinya. Drone yang digunakan pada skripsi ini berupa pesawat dengan empat buah baling-baling atau quadcopter. Skripsi ini membahas tentang sistem otomasi drone dengan menggunakan metode image processing. Tahapan yang pertama pada metode ini adalah feature detection untuk membaca tepi-tepi atau ujung dari suatu benda berdasarkan metode Shi-Tomasi. Data yang didapatk akan diolah pada tahapan optical flow. Tahapan ini dilakukan untuk menentukan jarak atau keberadaan suatu benda yang didasari oleh metode Lucas-Kanade. Namun karena sifatnya yang otomatis, drone tidak dapat terhindar dari kecelakaan jika terjadi kesalahan pembacaan hasil gambar. Untuk mengurangi kesalahan pembacaan, penulis menambahkan sistem sensor ultrasonik. Dengan pembacaan pada jarak tertentu sensor akan membantu pembacaan rintangan yang berada pada lintasan. Pengolahan citra sistem otomasi drone akan diuji coba dengan software OpenCV dan Microsoft Visual Studio. Selanjutnya akan diunduh pada Robot Operating System ROS pada drone. Visual feedback control berbasis pengendali PID digunakan sebagai kendali pengerak drone. Drone yang digunakan pada skripsi ini berupa pesawat dengan empat buah baling-baling atau quadcopter. Disini akan dibahas bagaimana cara kerja antara sensor kamera dan sensor ultrasonik bekerja terintegrasi secara bersamaan agar drone dapat menghindari rintangan secara otomatis.

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ABSTRACTAutomatic navigation on the drone is being developed on these days, from a wide variety of types of drones and its automatic functions. Drones used in this study is an aircraft with four propellers or quadcopter. This research discusses the drone automation system using image processing methods. The first stages in this method is the feature detection to read the edges or corner of an object based on the Shi Tomasi method. Then the data will be processed on the of optical flow phases. This stage will determine the distance or the presence of an object based on the Lucas Kanade method. Furthermore, the object distance is close and there on the track drones will be grouped and considered as obstacles using grouping stage based on the method of K means. But because it is automatic, drones can rsquo t avoid an accident if an error occurs reading the images. To reduce reading errors, the author adds ultrasonic sensor system. With a reading at a certain distance, sensor helps readings obstacles that are on the track. Drone image processing automation system will be tested with OpenCV software and Microsoft Visual Studio. Next the program will be downloaded on the Robot Operating System ROS on the drone. Visual feedback control based PID controllers are used as a control of drones movement. This paper will be discussed how to work the camera sensor and ultrasonic sensor working together so that the drones can avoid obstacles automatically."

"Penelitian ini memanfaatkan peristiwa ozonasi yang menghasilkan ozon dari udara bebas sebagai disinfektan untuk proses disinfeksi alternatif Salmonella sp. Untuk melakukan signifikansi proses disinfeksi ini, digunakan pembangkitan fenomena kavitasi ultrasonik dengan variasi intensitas gelombang ultrasonik sebesar 30, 60 dan 100%. Pada laju alir air 4 LPM (liter per menit) proses disinfeksi Salmonella sp. menunjukkan hasil yang terbaik dengan menggunakan peristiwa ozonasi maupun kombinasi kedua metode tersebut. Pada laju alir air 4 LPM pula dengan intensitas gelombang ultrasonik 100%, proses disinfeksi menggunakan ozonasi dan kavitasi ultrasonik menghasilkan pengurangan jumlah koloni bakteri paling cepat dibandingkan menggunakan konfigurasi lain dimana konsentrasi awal yang digunakan pada kisaran 105 CFU/mL berkurang hingga mencapai 0 CFU/mL dalam waktu 15 menit. Selain itu terbukti bahwa penggunaan kavitasi ultrasonik dapat meningkatkan kelarutan ozon di dalam air yang dibuktikan melalui perhitungan jumlah ozon residual. Peningkatan laju alir dan intensitas gelombang ultrasonik secara garis besar meningkatkan laju disinfeksi Salmonella sp pada penelitian ini.

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This study utilizes ozonation that produce ozone from the free air as a disinfectant for Salmonella sp. disinfection alternatives process. To achieve the significance of this disinfection process , ultrasonic cavitation phenomenon with variations in the intensity of ultrasonic waves of 30, 60 and 100% will be used . On the water flow rate 4 LPM (liters per minute) Salmonella sp. disinfection showed the best results by using ozonation or a combination of both methods. On the water flow rate 4 LPM also with ultrasonic waves intensity 100% , disinfection using ozonation and ultrasonic cavitation produce reduction in the number of bacterial colonies the fastest compared to other configurations in which the initial concentration used in the range of 105 CFU / mL decrease until it reaches 0 CFU / mL within 15 minutes. In addition it is evident that the use of ultrasonic cavitation can increase the solubility of ozone in water as showed by calculating the amount of residual ozone. Increased flow rate and the intensity of the ultrasonic waves can increase the rate of disinfection of Salmonella sp."