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Abstrak :
DETERMINATION OF MATERIAL AND ITS THICKNESS FOR Cs - 137 GAMMA SOURCE SHEILDING. Its has been determined the sheilding material and its thickness necessarily conducted due to every material will have different half - thickness characteristics, and by the selection a suitable material and its thickness will be obtained....

Abstrak :
The characterization of shield panel of X-ray radiation was carried out. Aim of the characterization is to find the panel in that qualities comply with the reference, so the panel can be used for the folding door of nuclear medical....

Abstrak :
Pelepasan ion Al dan V pada produk komersial implan medis Ti-6Al-4V dapat menyebabkan permasalahan kesehatan karena bersifat toksik. Selain itu modulus elastisitas implan medis Ti-6Al-4V relatif lebih tinggi dari modulus elastisitas tulang manusia, sehingga dapat menyebabkan fenomena stress shielding effect. Oleh sebab itu, dilakukan pergantian unsur Al dan V dengan unsur Nb dan Mo yang tidak bersifat toksik. Kemudian ditambahkan kembali unsur low cost Mn dengan variasi 2%, 4%, dan 6% untuk mensubtitusi unsur Nb dan Mo yang termasuk unsur yang relatif mahal. Unsur Nb, Mo dan Mn merupakan unsur penstabil fasa β yang memiliki nilai modulus elastisitas lebih rendah dibanding Ti-6Al-4V. Fasa β merupakan fasa yang stabil pada suhu tinggi, sehingga dilakukan perlakuan panas untuk menstabilkan fasa ini dengan homogenisasi pada 3, 6 dan 12 jam untuk mengetahui pengaruhnya. Hasil penelitian membuktikan bahwa penambahan komposisi Mn pada paduan menyebabkan penurunan efek toksisitas dengan menstabilkan pembentukan lapisan pasif pada permukaan logam. Lalu, didapatkan perolehan fraksi volume fasa β yang meningkat seiring penambahan komposisi unsur Mn sehingga didapatkan nilai modulus elastisitas yang menurun. Pada proses perlakuan panas, waktu 6 jam merupakan waktu yang optimal untuk memperoleh fasa β yang lebih homogen dengan mengeliminasi sisa fraksi volume fasa α yang ada pada paduan. Dapat disimpulkan penambahan komposisi unsur paduan Mn akan meningkatkan perolehan fasa β dan perlakuan panas perlu dilakukan untuk mendapatkan fasa β yang stabil dan homogen, sehingga didapatkan paduan yang lebih inert dengan nilai modulus elastisitas mendekati nilai modulus elastisistas tulang manusia.

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The release of Al and V ions in commercial products of Ti-6Al-4V medical implants can cause health problems because they are toxic. In addition, the modulus of elasticity of Ti-6Al-4V medical implants is relatively higher than the modulus of elasticity of human bones, so that it can cause stress shielding effect phenomena. Therefore, al and V elements are replaced with Nb and Mo elements which are not toxic. Then the low cost Mn element was added with variations of 2%, 4%, and 6% to substitute Nb and Mo elements which included relatively expensive elements. Nb, Mo and Mn elements are β phase stabilizers which have a modulus of elasticity lower than Ti-6Al-4V. The β phase is a phase that is stable at high temperatures, so heat treatment is carried out to stabilize this phase by homogenization at 3, 6 and 12 hours to determine its effect. As a result, the addition of the Mn composition to the alloy causes a decrease in the effect of toxicity by stabilizing the formation of a passive layer on the metal surface. Then, the acquisition of β phase volume fraction obtained increases with the addition of the composition of the element Mn so that the modulus of elasticity decreases. In the heat treatment process, 6 hours is the optimal time to obtain a more homogeneous β phase by eliminating the remaining α phase volume fraction present in the alloy. It can be concluded that the addition of Mn alloy element composition will increase β phase acquisition and heat treatment needs to be done to obtain a stable and homogeneous β phase, so that more inert alloys with elastic modulus values ​​are obtained close to the human bone elastic modulus.

Abstrak :
On transmission line towers can be installed fiber optic cables for control of power supplies and data communication. To avoid the damages of fiber optic cables cause of the eject of climate and environment, the shielding that used on fiber optic cables was made _#am the metal. With using this shielding, the electric field that produced from transmission line will be ejected With this shielding; the electric field that produced from transmission line will be higher or lower. There for, we must know the eject of using the fiber optic cables shielding to the electric field that produced from transmission line that installed fiber optic cables. This is useful to determinating the free room from the transmission line.

Abstrak :
Synthesis and Monte Carlo simulation of improved concrete composites as x-ray/gamma ray shielding materials were performed. Samples of shieldings were synthesized using the base materials of Portland-type cement concrete with fillers of alloy steel, Co, Mn, and Cr, mixed separately as additives. The samples were characterized using Scanning Electron Microscopy-Energy Dispersive X-ray Spectrometry (SEM-EDS) to determine the constituent elements quantitatively. Linear attenuation coefficients of the samples were measured in the experiments and also simulated using Monte Carlo transport code MCNP5 in order to evaluate their shielding performance. The results of the experimentation and computer simulation reveal concrete with alloy steel added as having the best shielding properties, although concrete with other fillers added also exhibited enhanced shielding performance. It was demonstrated that 6.06 w% of fillers enhanced the x-ray/gamma ray shielding capability of ordinary concrete composites by improving their attenuation coefficient values by 40–60%.

Abstrak :
In modern medicine, a radiation scans is an very important examination tool for making a diagnosis and subsequent treatment plan. Among the range of medical examinations, Computed tomography (CT) is being performed in an increasing number of cases and a CT scan uses the most radiation of any diagnostic exam. On the other hand, radiation protection during scanning is not typical for bodily regions other than those designated for examination. Therefore, the aim of this study was to develop a lead-free fused radiation shielding fiber (RSF) and to evaluate its effectiveness with a view to reducing radiation exposure to only the effective dose or less in a CT scan by means of a multilayer structural coating. A GE High Speed Advantage Spiral CT was used to conduct measurements using a FH-40G (Eberline, USA) proportional digital counter survey meter. In a brain CT scan, abdominal CT scan, and knee CT scan, two-way ANOVA was used to analyze the changes in radiation dosage and to examine the correlation based on body parts and thickness of the RSF. In addition, when significant results were obtained, a Duncan post hoc test was used to examine the difference depending on each condition. In the brain CT scan, the highest exposure to secondary radiation was measured in the chest, which was closest in distance. The use of a 3- mm shielding fiber resulted in a shielding effect of approximately 65% shielding effect compared to the initial exposure dose. In the abdominal CT scan, no exposure dose was detected in the head area, which had been shielded with the 3-mm shielding fiber. In a knee CT scan, 1-mm shielding fiber was sufficient to demonstrate a shielding effect. The RSF developed in this study may help reduce low-dose exposure to secondary X-rays, such as scattered rays.

Abstrak :
ABSTRAK
Semakin banyaknya kegiatan konstruksi pada lahan terbatas menyebabkan jarak antara bangunan satu dengan lainnya sangat dekat. Misalnya pada kasus embankment yang berdekatan dengan suatu bangunan yang sudah ada. Konstruksi embankment ini dapat menyebabkan tanah di bawahnya bergerak sehingga dapat mengganggu tiang-tiang eksisting yang menopang struktur bangunan. Pengaruh tersebut antara lain terjadinya settlement dan lateral soil movement. Komponen terakhir dianggap lebih kritis dampaknya terhadap adjacent piles, khususnya pada kondisi tanah yang lunak yang mengalami tekanan akibat konstruksi embakment sehingga tanah bergerak secara horizontal menekan adjacent piles. Untuk itu perlu diberikan shielding piles pada tanah yang berfungsi meminimalisasi efek embankment terhadap lateral soil movement.

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ABSTRACT
Increasing number of construction activities on a limited land causes distance between the buildings to each other very closely, For example in embankment case adjacent to an existing building. Embankment construction can cause the ground beneath him move that can interfere with the existing pillars that support the structure buildings. Influences include the settlement and lateral soil movement. The last component is considered more critical impact on the adjacent iles, especially in soft ground conditions that have pressure due to construction so that the soil mbakment moves horizontal pressing adjacent piles. It needs to be given to shielding Pile on the ground that serves to minimize the effects of Embankment on lateral soil movement.

Abstrak :
Baja tahan karat Austenitik tipe 304 merupakan jenis yang terluas pemakaiannya, yaitu sekitar 65 -70 % dari total kebutuhan baja tahan karat. Baja ini mempunyai sifat yang sangat reaktif pada temperatur di atas 500 _C, sehingga menimbulkan korosi batas butir ( intergranular corrosion ) pada temperature sensitization ( 500 ? 800 _C ) sesuai dengan beberapa kondisi, antara lain a). proses pengelasan b). perlakuan panas dan c). kondisi lapangan. Hasil pengelasan baja tahan karat austenitik dipengaruhi banyak faktor, antara lain jenis logam pengisi, persiapan material sebelum di las, perlakuan sebelum dan sesudah di las, gas pelindung yang digunakan dan lain-lain. Penelitian ini bertujuan mempelajari pengaruh media pendingin terhadap struktur mikro dan sifat mekanis pengelasan austenitik tipe 304 dengan FCAW dan dengan media pendingin udara, air dan perlakuan preheating serta gas pelindung CO2 dan gas pelindung campuran (CO2 + Argon ). Hasil penelitian enam sampel yang diuji dengan parameter media pendingin yang berbeda dan gas pelindung yang juga berbeda, diperoleh kekuatan tarik dan kekerasan yang bervariasi, mulai dari kekuatan tarik 605 MPa sampai dengan 648 MPa dan kekerasan vickers di HAZ dari 220 HV sampai dengan 268 HV. Hasil pengelasan optimum terdapat pada Sampel B ( media pendingin air dan gas pelindung CO2 ). Pembentukan krom karbida di HAZ, paling banyak terdapat pada Sampel D ( krom 29, 42 wt% ) dan paling sedikit pada Sampel A ( krom 12,25 wt% )......Austenitic stainless steel type 304 is the most widely used type, which is about 65 -70% of the total demand for stainless steel. This steel has very reactive properties at temperatures above 500 _C, causing intergranular corrosion at temperature sensitization ( 500 ? 800 _C ) in accordance with several conditions, including a). welding process b). heat treatment and c). field conditions. The results of welding of austenitic stainless steel are influenced by many factors, including the type of filler metal, preparation of the material before welding, treatment before and after welding, the shielding gas used and others. This study aims to study the effect of the cooling medium on the microstructure and mechanical properties of type 304 austenitic welding with FCAW and with air cooling, water and preheating treatment as well as CO2 shielding gas and mixed shielding gas (CO2 + Argon). The results of the six samples tested with different cooling media parameters and different shielding gases, obtained varying tensile strengths and hardness, ranging from tensile strength of 605 MPa to 648 MPa and Vickers hardness in HAZ from 220 HV to 268 HV. The optimum welding results were found in Sample B (water cooling media and CO2 protective gas). The formation of chromium carbide in HAZ was most abundant in Sample D (chrome 29.42 wt% ) and the least in Sample A (chromium 12.25 wt% ).