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Abstrak :
Au-Ag nanoalloys disintesis dengan menggunakan tehnik laser radiasi femtosecond dengan metode top-down maupun bottom-up. Metode top-down Au-Ag nanoalloys disintesis dari pelat Au dan Ag sedangkan metode bottom-up disintesis dari garam metal silver nitrate AgNO3 dan garam metal emas Potassium gold III chloride K AuCl4 . Pada metode top-down, pelat Au dan Ag ditembak dengan radiasi laser femtosecond, dihasilkan nanopartikel emas AuNPs dan nanopartikel perak AgNPs dengan waktu abalasi 25 menit dan 1 jam. Kemudian dicampur dengan perbandingan 50:50 dan ditembak laser kembali dengan waktu irradiasi yang berbeda sehingga dihasilkan Au-Ag Nanoalloys dengan ukuran 12-13 nm. Sedangkan pada metode bottom-up, Au-Ag Nanoalloys dibuat dari perbandingan larutan ion Au dan larutan Ag yaitu Au100Ag0 100:0 , Au10Ag90 10:90 , Au80Ag20 80:20 , Au70Ag30 70:30 , Au60Ag40 60:40 , Au50Ag50 50:50 , Au40Ag60 40:60 , Au70Ag30 70:30 , Au80Ag20 80:20 , Au10Ag90 10:90 dan Au100Ag0 100:0 pada medium air, medium air PVP 0,01 dan medium air PVP 0,1 dan setiap komposisi tersebut pada setiap medium ditembak dengan waktu iradiasi laser yang berbeda sehingga dihasilkan Au-Ag Nanoalloys dengan ukuran partikel 5-10 nm. Setelah Au-Ag nanoalloys terbentuk, sifat optiknya dipelajari yaitu pergeseran surface plasmon. Dimana surface plasmon dipengaruhi oleh oleh ukuran nanomaterial, bentuk, komposisi, pengaruh kimia dan lingkungan sekitar nanopartikel. ...... Au Ag Nanoalloys are synthesized with femtosecond laser technique with top down and bottom up methods. In top down Au Ag Nanoalloys are synthesized from 99 plate Au and Ag, while bottom up method Au Ag Nanoalloys are synthesized from silver nitrate metal salt AgNO3 dan Potassium gold III chloride K AuCl4 . In top down 99 plate Au and Ag were shot laser, respectively until result nanogold AuNPs and nanosilver AgNPs at 25 minutes and 1 hour ablation time and then mix with ratio 50 50, after that was shot laser with different irradiation time until Au Ag Nanoalloys formed with particle size of 12 13 nm. And in bottom up Au Ag Nanoalloys are made from the different ratio ion liquid Au and Ag that is Au100Ag0 100 0 , Au10Ag90 10 90 , Au80Ag20 80 20 , Au70Ag30 70 30 , Au60Ag40 60 40 , Au50Ag50 50 50 , Au40Ag60 40 60 , Au70Ag30 70 30 , Au80Ag20 80 20 , Au10Ag90 10 90 dan Au100Ag0 100 0 in water medium, water medium PVP 0,01 and water medium PVP 0,1 . Each different molar ratio in the different medium was shot with different irradiation time resulting Au Ag Nanoalloys with particle size of 5 10 nm. After Au Ag formed, the optical properties are studied i.e. the shift of surface plasmon. Where surface plasmon is affected by nanoparticle size, shape, composition, chemical and environment around nanoparticle.

Abstrak :
ABSTRACT A series of experimental studies on the emission spectra of laser-induced plasma at reduced ambient gas pressure were carried out for the analyses of organic materials. The plasma was generated by means of a Q-switch Nd-YAG laser having a pulse width of 8 ns, wavelength of 1,064 nm and operated at an energy of 120 mJ. The emission was detected with time-integrated and time resolved spectroscopic techniques. These studies were intended to investigate the possible extension of the previously established technique of laser induced shock-wave plasma spectroscopy (LISPS) for its applications to organic samples of different natures as well as to examine the related excitation mechanism and the effects of different experimental conditions on the plasma generation. The first experiment was conducted on soft solid organic samples or samples which have low melting point. It is well known that plasma emission from soft organic samples can not be directly produced by Nd-YAG laser irradiation even in low pressure surrounding gas. We have shown in this experiment that this problem can be overcome by placing a hard sub-target behind or underneath the soft samples or putting an obstacle in front of it. The sharp emission lines of light elements such as hydrogen, carbon and chlorine from organic samples were clearly observed from a black polyvinyl chloride plastic sheet when the shock wave plasma was generated in appropriately chosen low-pressure of the ambient air. In the second experiment, the same technique has been successfully applied for hydrogen and carbon atomic emission analysis in various fossil samples at low gas pressure around 3 Torr. The quality of the spectrum allows a quantitative comparison of the carbon and hydrogen emission intensities with the associated molecular band spectra, yielding a rough estimation of the period of fossilization process. In the third experiment, another successful application of this technique was also achieved for spectrochemical analysis of bead samples, which offers the possibility of its applications for non destructive identifications of genuine beads as well as its potential application to other areas of forgery inspection. In addition to the variety of applications demonstrated in those experiments, the related study has also verified the distinct role of laser induced shockwave in the generation of excitation process leading to the observed favorable plasma emission. We show in this connection the crucial condition of low pressure ambient gas for producing the sharp emission lines desirable for high resolution and quantitative analysis. It was further demonstrated that the mass difference between the host elements and the impurity elements has a sensitive effect on the pressure dependent characteristics of the emission lines to be analyzed. On the basis of those results, we have reason to hold out hope for the extension of the technique developed in this study to more credible quantitative spectrochemical analysis of organic samples, including those of biomedical interest and those in the form of thin films.

Abstrak :
ABSTRACT A series of experimental studies on the emission spectra of laser-induced plasma at reduced ambient gas pressure were carried out for the analyses of organic materials. The plasma was generated by means of a Q-switch Nd-YAG laser having a pulse width of 8 ns, wavelength of 1,064 nm and operated at an energy of 120 mJ. The emission was detected with time-integrated and time resolved spectroscopic techniques. These studies were intended to investigate the possible extension of the previously established technique of laser induced shock-wave plasma spectroscopy (LISPS) for its applications to organic samples of different natures as well as to examine the related excitation mechanism and the effects of different experimental conditions on the plasma generation. The first experiment was conducted on soft solid organic samples or samples which have low melting point. It is well known that plasma emission from soft organic samples can not be directly produced by Nd-YAG laser irradiation even in low pressure surrounding gas. We have shown in this experiment that this problem can be overcome by placing a hard sub-target behind or underneath the soft samples or putting an obstacle in front of it. The sharp emission lines of light elements such as hydrogen, carbon and chlorine from organic samples were clearly observed from a black polyvinyl chloride plastic sheet when the shock wave plasma was generated in appropriately chosen low-pressure of the ambient air. In the second experiment, the same technique has been successfully applied for hydrogen and carbon atomic emission analysis in various fossil samples at low gas pressure around 3 Torr. The quality of the spectrum allows a quantitative comparison of the carbon and hydrogen emission intensities with the associated molecular band spectra, yielding a rough estimation of the period of fossilization process. In the third experiment, another successful application of this technique was also achieved for spectrochemical analysis of bead samples, which offers the possibility of its applications for non destructive identifications of genuine beads as well as its potential application to other areas of forgery inspection. In addition to the variety of applications demonstrated in those experiments, the related study has also verified the distinct role of laser induced shockwave in the generation of excitation process leading to the observed favorable plasma emission. We show in this connection the crucial condition of low pressure ambient gas for producing the sharp emission lines desirable for high resolution and quantitative analysis. It was further demonstrated that the mass difference between the host elements and the impurity elements has a sensitive effect on the pressure dependent characteristics of the emission lines to be analyzed. On the basis of those results, we have reason to hold out hope for the extension of the technique developed in this study to more credible quantitative spectrochemical analysis of organic samples, including those of biomedical interest and those in the form of thin films.

Abstrak :
ABSTRAK
Pada proses engraving penggunaan laser berdaya tinggi marak digunakan saat ini. Laser daya tinggi yang sering digunakan adalah laser gas seperti CO2, Nd:YaG dan laser diode. Laser diode memiliki beberapa kekurangan diantaranya sudut divergensi lebar, astigmatisme dan beam profile yang tidak ideal yang berbentuk elips. Kekurangan tersebut menyebabkan kualitas beam profile yang buruk. Oleh karena itu perlu dilakukan koreksi beam pada output diode untuk mengurangi rasio elips yang dimilikinya. Metode koreksi yang umum dilakukan adalah dengan menggunakan dua lensa silinder untuk melakukan koreksi pada sumbu horisontal dan vertikal.Pada tesis ini telah dikembangkan metode koreksi output beam berbasis pada ray tracing analysis untuk menghitung struktur susunan lensa yang meliputi pengaturan fokus dan jarak antara lensa ndash; lensa silinder yang digunakan untuk mengurangi rasio elips serta lensa pemfokus untuk mendapatkan ukuran beam yang diinginkan. Hasil experiment terhadap metode koreksi beam diamati melalui dua cara yaitu; 1 pengamatan burning spot dengan mikroskop digital dan 2 menghitung hasil foto menggunakan MATLAB. Hasil kedua metode ini menunjukan pengurangan rasio elips. Pengurangan rasio elips dari 1.43 menjadi 1.14 pada pengamatan burning spot. Selain itu, dilakukan pula karakterisasi kebutuhan intensitas terhadap waktu pembakaran beberapa objek material.

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ABSTRACT
In the process of engraving the use of high power lasers are rife in use today. The most commonly used high power lasers are gas lasers such as CO2, Nd YaG and also semiconductor, laser diodes. Laser diodes have some disadvantages such as wide divergence angles, astigmatism and elliptical beam profile. These deficiencies cause poor beam profile quality. Therefore it is necessary to do beam correction at the output diode to reduce the ratio of the ellipse it has. A common method of correction is to use two cylindrical lenses to correct the horizontal and vertical axes.In this paper use this ray tracing method for focus setting, the distance on the cylinder lenses and the focusing lens are used to reduce the ellipse ratio and obtain the desired beam size. The experimental results of the beam correction method were observed in two ways 1 observation of spot burning with digital microscope and 2 calculate the result of photo using MATLAB. The results of both methods show a reduction in the elliptical ratio. The reduction of the ellipse ratio is from 1.43 to 1.14 on the observation of burning. In addition, there is also characterization of the need for intensity to burning time of some material objects.

Abstrak :
Saat ini komputasi tomografi (CT) sinar-X sudah banyak diterapkan di industri manufaktur untuk keperluan kontrol kualitas seperti penentuan cacat, porositas, koreksi geometri manufaktur dan reverse engineering. Kemampuan untuk memeriksa struktur internal material yang kompleks tanpa merusak konstruksi material tersebut merupakan salah satu keuntungan CT industri. Namun biaya perangkat CT industri komersial sangat mahal, karena hampir semuanya diimpor. Penelitian ini bertujuan untuk mengembangkan perangkat CT sinar-X berbasis fluoroskopi untuk industri manufaktur. Perangkat ini terdiri dari komponen utama yaitu detektor fluoroskopi, meja putar, pesawat sinar-X dan komputer beserta perangkat lunak akuisisi dan rekonstruksi citra. Telah dilakukan akuisisi citra dengan menggunakan berbagai benda uji dengan bentuk, material dan ketebalan yang berbeda beda. Kualitas citra tomografi berbagai benda uji sangat memuaskan. Data penelitian ini diharapkan dapat dijadikan referensi untuk pengembangan perangkat CT industri yang produksi dalam negeri dengan biaya lebih murah. ......Currently, X-ray computed tomography (CT) has been widely applied in the manufacturing industry for quality control purposes such as defect determination, porosity, manufacturing geometry correction, and reverse engineering. The ability to inspect the internal structure of complex materials without destructive the construction of the material is one of the advantages of industrial CTs. However, the cost of commercial industrial CT devices is very expensive, because almost all of them are imported. This study aims to develop a development of fluoroscopy-based X-ray CT system for the manufacturing industry. The device consists of the main components, that is a fluoroscopy detector, a rotary table, an X-ray device, and a computer along with image acquisition and reconstruction software. Image acquisition has been carried out using various test objects with different shapes, materials, and thicknesses. The tomographic image quality of various test objects is very satisfying. Hopefully this research data can be used as references for the development of producing a low-cost industrial X-ray CT equipment made within the country.

Abstrak :
The book is mainly focused on micromachining of transparent materials which, due to the nonlinear absorption mechanism of ultrashort pulses, allows unique three-dimensional capabilities and can be exploited for the fabrication of complex microsystems with unprecedented functionalities.

Abstrak :
"Providing a clear theoretical understanding of MEMS and NEMS, Solid-State Physics, Fluidics, and Analytical Techniques in Micro- and Nanotechnology covers all aspects of solid state physics behind nanotechnology and science. After exploring the rise of Si, MEMS, and NEMS in a historical context, the text discusses crystallography, quantum mechanics, the band theory of solids, and the silicon single crystal. It concludes with coverage of photonics, the quantum hall effect, and superconductivity. The text offers end-of-chapter problems, worked examples throughout, extensive references, and PowerPoint slides for download, along with a solutions manual for qualifying instructors"-- "In Solid State Physics, Fluidics and Analytical Techniques in Micro- and Nanotechnology we lay the foundations for a qualitative and quantitative theoretical understanding of micro-and nano-electromechanical systems, i.e., MEMS and NEMS. In integrated circuits (ICs), MEMS and NEMS, silicon (Si) is still the substrate and construction material of choice"--