scholarly journals Gamma Shielding Experiment Simulation utilizing MCNPX Code

2021 ◽  
Vol 12 (2) ◽  
pp. 11-21
Author(s):  
Shafiqul Islam Faisal ◽  
Abi Muttaquin Bin Jalal Bayar

Experimental investigation requires materials, radiation sources, and test arrangements with a high monetary financial plan. Furthermore, radiation exposure involves people during the experiment. On the contrary, the simulation technique for examining radiation interactions is radio-logically safer, less timeconsuming, cost-effective, and applicable for all desired radiation sources. Through 48.86 mCi 662 keV Caesium-137 gamma-ray source; shielding experiment as well as simulation of it with MCNPX were performed for three shielding materials Lead, Copper, and Aluminum. These materials were placed in front of the gamma source and the emergent radiation was counted in a Geiger- Muller detector to understand the attenuation quality of these materials to each other. These courses of action were simulated utilizing the MCNPX code version 2.7.0 and the results likewise gave and looked at that of the experiment. There are huge similarities of shielding behavior between MCNPX simulation and experiments for the three absorbing materials. The modeled geometry of this MCNPX simulation could be used for future approaches of new designs and structures of radiation shielding, especially where no analogous experimental data exist Journal of Engineering Science 12(2), 2021, 11-21

2018 ◽  
Vol 9 (08) ◽  
pp. 20193-20206 ◽  
Author(s):  
Md. Akhlak Bin Aziz ◽  
Md. Faisal Rahman ◽  
Md. Mahidul Haque Prodhan

The paper compares  Lead, Copper and Aluminium as gamma radiation shielding material using both experimental and simulation techniques. Cs- 137 (662KeV), Na-22 (511KeV) and Na- 22(1274KeV) were used as gamma radiation sources and a sodium iodide (NaI) detector was used to detect the radiation. Variations were noted for detected gamma count rates by changing shielding material thickness. In the experimental approach, thickness was varied by placing sheets of a particular test material one by one. For simulation, Monte Carlo n- Particle (MCNP) code version 4c was used and the geometry of the whole experimental setup was plotted in it. The results were then compared for each test material and it was found that lead is the best shielding material for gamma radiation followed by copper and aluminium.


2019 ◽  
Vol 21 (2) ◽  
pp. 108-114
Author(s):  
Abdus Sattar Mollah

Gamma-ray radiation shielding properties such as linear attenuation coefficient (m), mass attenuation coefficient (m/r), half- value thickness (HVT), tenth value thickness (TVL) and mean free path (MFP) were calculated for different types of radiation absorbing materials such as Concrete, Aluminum, Iron, Copper, Lead, Lead-glass and Tungsten. These materials are being widely used as radiation shielding materials in different areas of nuclear medicine facilities for different purposes. The XCOM and in-house developed computer program were used to calculate the above mentioned parameters for gamma-ray energies of 100 keV, 200 keV and 511 keV. The gamma-ray energy range used in nuclear medicine is between 100 keV and 511 keV. Results show that attenuation coefficient decreases with increase of gamma-ray energy, and attenuation coefficient increases with increase of density and shows significant variation for different materials. Linear attenuation coefficient depends on the energy of incident gamma-rays and the nature of the absorbing materials. These gamma-ray attenuation parameters of different absorbing materials can be used for proper shielding design of syringe shield, isotope storage container, isotope transport container, personnel protective shield barrier, radioactive waste storage facility etc.  in nuclear medicine services. Bangladesh J. Nuclear Med. 21(2): 108-114, July 2018  


Author(s):  
I.N. Voronchikhina ◽  
◽  
A.G. Marenkova ◽  
V. S. Rubets ◽  
V. V. Pylnev

The results of elements development of varietal agrotechnics of a new high-potential line 238h of winter triticale presented. It was identified that under the conditions of 2020 the most cost effective fertilizer system is an early spring application of NPK (S) (15-15-15 (10)) at a dose of 200kg/ha. The profitability level of this fertilizer was 88,9%.


1998 ◽  
Vol 37 (4II) ◽  
pp. 873-882 ◽  
Author(s):  
Sarfaraz Khan Quershi

Growth in telecom infrastructure and provision of modern telecom services to consumers at a cost based tariff helps growth of national economy. Modern telecoms serve as the engine of growth of national economy. Following the global trends of liberalisation and deregulation in telecoms monopolies which have thus far been providing inefficient communication at a greedily high tariffs are falling apart. Mergers in telecoms are not for increasing the size of the monopoly but to provide more efficient and cost effective services to the consumers. In Pakistan the erstwhile T&T department played a needful role at its time. Conversion of the department into a corporation and then into a company were steps necessary for following the global trends. Need now is to continue this trend further, eliminate the monopolistic approach by allowing more players in the field thus permitting the market forces to decide the provision of better quality of modern services at competitive price.


Author(s):  
Gwee Hoon Yen ◽  
Ng Kiong Kay

Abstract Today, failure analysis involving flip chip [1] with copper pillar bump packaging technologies would be the major challenges faced by analysts. Most often, handling on the chips after destructive chemical decapsulation is extremely critical as there are several failure analysis steps to be continued such as chip level fault localization, chip micro probing for fault isolation, parallel lapping [2, 3, 4] and passive voltage contrast. Therefore, quality of sample preparation is critical. This paper discussed and demonstrated a quick, reliable and cost effective methodology to decapsulate the thin small leadless (TSLP) flip chip package with copper pillar (CuP) bump interconnect technology.


2017 ◽  
Vol 6 (04) ◽  
pp. 5347 ◽  
Author(s):  
Omar B. Ahmed* ◽  
Anas S. Dablool

Several methods of Deoxyribonucleic acid (DNA) extraction have been applied to extract bacterial DNA. The amount and the quality of the DNA obtained for each one of those methods are variable. The study aimed to evaluate bacterial DNA extraction using conventional boiling method followed by alcohol precipitation. DNA extraction from Gram negative bacilli was extracted and precipitated using boiling method with further precipitation by ethanol. The extraction procedure performed using the boiling method resulted in high DNA yields for both E. coli and K. pneumoniae bacteria in (199.7 and 285.7μg/ml, respectively) which was close to control method (229.3 and 440.3μg/ml). It was concluded that after alcohol precipitation boiling procedure was easy, cost-effective, and applicable for high-yield quality of DNA in Gram-negative bacteria.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1158
Author(s):  
Huseyin O. Tekin ◽  
Shams A. M. Issa ◽  
Gokhan Kilic ◽  
Hesham M. H. Zakaly ◽  
Mohamed M. Abuzaid ◽  
...  

In the current study, promising glass composites based on vanadium pentoxide (V2O5)-doped zinc borate (ZnB) were investigated in terms of their nuclear-radiation-shielding dynamics. The mass and linear attenuation coefficient, half-value layer, mean free path, tenth-value layer, effective atomic number, exposure-buildup factor, and energy-absorption-buildup factor were deeply simulated by using MCNPX code, Phy-X PSD code, and WinXcom to study the validation of ZBV1, ZBV2, ZBV3, and ZBV4 based on (100−x)(0.6ZnO-0.4B2O3)(x)(V2O5) (x = 1, 2, 3, 4 mol%) samples against ionizing radiation. The results showed that attenuation competencies of the studied glasses slightly changed while increasing the V2O5 content from 1 mol% to 4 mol%. The domination of ZnO concentration in the composition compared to B2O3 makes ZnO substitution with V2O5 more dominant, leading to a decrease in density. Since density has a significant role in the attenuation of gamma rays, a negative effect was observed. It can be concluded that the aforementioned substitution can negatively affect the shielding competencies of studied glasses.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Michael J. Allison ◽  
Jessica M. Round ◽  
Lauren C. Bergman ◽  
Ali Mirabzadeh ◽  
Heather Allen ◽  
...  

Abstract Objective Silica gel beads have promise as a non-toxic, cost-effective, portable method for storing environmental DNA (eDNA) immobilized on filter membranes. Consequently, many ecological surveys are turning to silica bead filter desiccation rather than ethanol preservation. However, no systematic evaluation of silica bead storage conditions or duration past 1 week has been published. The present study evaluates the quality of filter-immobilized eDNA desiccated with silica gel under different storage conditions for over a year using targeted quantitative real-time polymerase chain reaction (qPCR)-based assays. Results While the detection of relatively abundant eDNA target was stable over 15 months from either ethanol- or silica gel-preserved filters at − 20 and 4 °C, silica gel out-performed ethanol preservation at 23 °C by preventing a progressive decrease in eDNA sample quality. Silica gel filter desiccation preserved low abundance eDNA equally well up to 1 month regardless of storage temperature (18, 4, or − 20 °C). However only storage at − 20 °C prevented a noticeable decrease in detectability at 5 and 12 months. The results indicate that brief storage of eDNA filters with silica gel beads up to 1 month can be successfully accomplished at a range of temperatures. However, longer-term storage should be at − 20 °C to maximize sample integrity.


Kidney Cancer ◽  
2021 ◽  
pp. 1-14
Author(s):  
Elizabeth E. Ellis ◽  
Edward Messing

Background: Our goal is to review current literature regarding active surveillance (AS) of small renal masses (SRMs) and identify trends in survival outcomes, factors that predict the need for further intervention, and quality of life (QOL). Methods: We performed a comprehensive literature search in PubMed and EMBASE and identified 194 articles. A narrative summary was performed in lieu of a meta-analysis due to the heterogeneity of selected studies. Results: Seventeen articles were chosen to be featured in this review. Growth rate (GR) was not an accurate predictor of malignancy, although it was the characteristic most commonly used to trigger delayed intervention (DI). The mean 5-year overall survival (OS) of all studies was 73.6% ±1.7% for AS groups. The combined cancer specific survival (CSS) for AS is 97.1% ±0.6% , compared to 98.6% ±0.4% for the primary intervention (PI) groups, (p = 0.038). Conclusions: Short and intermediate-term data demonstrate that AS with the option for DI is a management approach whose efficacy (in terms of CSS) approaches that of PI at 5 years, is cost effective, and prevents overtreatment, especially in patients with significant comorbidities.


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