scholarly journals Homogenization Effects of VVER-1000 Fuel Assembly on Criticality Calculations

2020 ◽  
Vol 8 (1) ◽  
pp. 1-6
Author(s):  
Sardar Muhammad Shauddin
Keyword(s):  
Fuel Assembly ◽  
Room Temperature ◽  
Cost Effective ◽  
Reactor System ◽  
Relative Power ◽  
Delayed Neutron ◽  
Heterogeneous Reactor ◽  
Energy Neutron ◽  
Homogeneous Reactor ◽  
Neutronic Parameters

Due to cost effective and simplicity homogeneous reactors have been widely used for experimental and research purposes. Parameters which are difficult to get from a heterogeneous reactor system can be easily obtained from a homogeneous reactor system and can be applied in the heterogeneous reactor system if the major parametric differences are known. In this study, homogenization effects of VVER (Water Water Energetic Reactor)-1000 fuel assembly on neutronic parameters have been analyzed with the universal probabilistic code MCNP (Monte Carlo N-Particle). The infinite multiplication factor (k∞) has been calculated for the reconfigured heterogeneous and homogenous fuel assembly models with 2 w/o U-235 enriched fuel at room temperature. Effect of mixing soluble boron into the moderator/coolant (H2O) has been investigated for both models. Direct and fission detected thermal to higher energy neutron ratio also has been investigated. Relative power distributions of both models have been calculated at critical and supercritical states. Burnup calculations for both the reconfigured cores have been carried out up to 5 years of operation. Effective delayed neutron fraction (βeff) and prompt removal lifetime (ℓ) also have been evaluated. All the results show significant differences between the two systems except the average relative power.

scholarly journals Facile Green, Room-Temperature Synthesis of Gold Nanoparticles Using Combretum erythrophyllum Leaf Extract: Antibacterial and Cell Viability Studies against Normal and Cancerous Cells

Antibiotics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 893
Author(s):  
Olufunto T. Fanoro ◽  
Sundararajan Parani ◽  
Rodney Maluleke ◽  
Thabang C. Lebepe ◽  
Jose R. Varghese ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Cell Viability ◽  
Leaf Extract ◽  
Room Temperature ◽  
Klebsiella Oxytoca ◽  
Cost Effective ◽  
Average Diameter ◽  
Antibacterial Activities ◽  
Inhibition Concentration ◽  
First Time

We herein report a facile, green, cost-effective, plant-mediated synthesis of gold nanoparticles (AuNPs) for the first time using Combretum erythrophyllum (CE) plant leaves. The synthesis was conducted at room temperature using CE leaf extract serving as a reducing and capping agent. The as-synthesized AuNPs were found to be crystalline, well dispersed, and spherical in shape with an average diameter of 13.20 nm and an excellent stability of over 60 days. The AuNPs showed broad-spectrum antibacterial activities against both pathogenic Gram-positive (Staphylococcus epidermidis (ATCC14990), Staphylococcus aureus (ATCC 25923), Mycobacterium smegmatis (MC 215)) and Gram-negative bacteria (Proteus mirabilis (ATCC 7002), Escherichia coli (ATCC 25922), Klebsiella pneumoniae (ATCC 13822), Klebsiella oxytoca (ATCC 8724)), with a minimum inhibition concentration of 62.5 µg/mL. In addition, the as-synthesized AuNPs were highly stable with exceptional cell viability towards normal cells (BHK- 21) and cancerous cancer cell lines (cervical and lung cancer).

Preparation and Characterization of Sawdust Derived Bio-Fuel Pellets Depending on "Solid Bridge" Intertwining Action of Hyacinth Fiber

2014 ◽  
Vol 878 ◽  
pp. 450-458
Author(s):  
Ling Jun Kong ◽  
Xiong Fei Zhang ◽  
Shuang Hong Tian ◽  
Ting Liu ◽  
Ya Xiong
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Elastic Recovery ◽  
Impact Resistance ◽  
Resistance Index ◽  
Cost Effective ◽  
Environmental Benefits ◽  
Fuel Pellet ◽  
Mass Ratio ◽  
Solid Bridge

Densified biomass pellets named as H/S-BPs were prepared from waste wood sawdust (S) in the presence of water hyacinth fiber (H) as solid bridge under room temperature and 6 MPa lower than in the previous study. Mechanical properties including relaxed density (ρr), resiliency (R), abrasion resistance (AR) and impact resistance index (IRI) were evaluated. Results showed that adding H greatly reduced negative effect of resiliency on the mechanical properties of H/S-BPs during storage. For example, H/S-BPs compressed at 6 MPa in an H/S mass ratio of 1 to 3 presented lower resiliency of 10% and higher relaxed density of 1.04 kg dm-3 than pellets without H fiber. This is due to the intertwining action of H fiber, what fabricates solid bridge, replacing the bonding creating by applying high pressure to resist the disruptive force caused by elastic recovery. Thus, compression of waste H and S in a mass ratio of 1 to 3 at room temperature under 6 MPa is a cost-effective process to produce densified sustainable bio-fuel pellet as well as dispose waste S and H, combining the economical and environmental benefits.

Neutronic Analysis of Accident-Tolerant Fuel Assemblies With Silicon Carbide Cladding in Pressurized Water Reactors

2017 ◽  
Author(s):  
Zhixiong Tan ◽  
Jiejin Cai
Keyword(s):  
Silicon Carbide ◽  
Fuel Assembly ◽  
Power Distribution ◽  
Safety Margin ◽  
Severe Accident ◽  
Pressurized Water Reactors ◽  
Fuel Pellet ◽  
Pressurized Water ◽  
Neutronic Parameters ◽  
Water Reactors

After Fukushima Daiichi Nuclear Power Plant accident, alternative fuel-design to enhance tolerance for severe accident conditions becomes particularly important. Silicon carbide (SiC) cladding fuel assembly gain more safety margin as novel accident tolerant fuel. This paper focuses on the neutron properties of SiC cladding fuel assembly in pressurized water reactors. Annular fuel pellet was adopted in this paper. Two types of silicon carbide assemblies were evaluated via using lattice calculation code “dragon”. Type one was consisted of 0.057cm SiC cladding and conventional fuel. Type two was consisted of 0.089cm SiC cladding and BeO/UO2 fuel. Compared the results of SiC cladding fuel assembly neutronic parameters with conventional Zircaloy cladding fuel assembly, this paper analyzed the safety of neutronic parameters performance. Results demonstrate that assembly-level reactivity coefficient is kept negative, meanwhile, the numerical value got a relatively decrease. Other parameters are conformed to the design-limiting requirement. SiC kinds cladding show more flat power distribution. SiC cases also show the ability of reducing the enrichment of fuel pellets even though it has higher xenon concentration. These types of assembly have broadly agreement neutron performance with the conventional cladding fuel, which confirmed the acceptability of SiC cladding in the way of neutron physics analysis.

Preservation of sperm within the mouse cauda epididymidis in salt or sugars at room temperature

Zygote ◽  
2010 ◽  
Vol 18 (3) ◽  
pp. 245-256 ◽  
Author(s):  
Tetsuo Ono ◽  
Eiji Mizutani ◽  
Chong Li ◽  
Teruhiko Wakayama
Keyword(s):  
Room Temperature ◽  
Polar Body ◽  
Methylation Status ◽  
Cost Effective ◽  
Oocyte Activation ◽  
Male Gametes ◽  
Effective Manner ◽  
Cell Embryo ◽  
Cauda Epididymidis ◽  
Second Polar Body

SummaryThe development of preservation techniques for male gametes at room temperature might allow us to store them in a simple and cost-effective manner. In this study, we studied the use of pure salt or sugar to preserve the whole cauda epididymidis, because it is known that food can be preserved in this way at room temperature for long periods. Mouse epididymides were placed directly in powdered salt (NaCl) or sugars (glucose or raffinose) for 1 day to 1 year at room temperature. Spermatozoa were recovered from the preserved organs after being rehydrated with medium and then isolated sperm heads were microinjected into fresh oocytes. Importantly, the oocyte activation capacity of spermatozoa was maintained after epididymal storage in NaCl for 1 year, whereas most untreated spermatozoa failed to activate oocytes within 1 month of storage. Pronuclear morphology, the rate of extrusion of a second polar body and the methylation status of histone H3 lysine 9 (H3K9me3) in those zygotes were similar to those of zygotes fertilized with fresh spermatozoa. However, the developmental ability of the zygotes decreased within 1 day of sperm storage. This effect led to nuclear fragmentation at the 2-cell embryo stage, irrespective of the storage method used. Thus, although the preserved sperm failed to allow embryo development, their oocyte activation factors were maintained by salt storage of the epididymis for up to 1 year at room temperature.

DESCRIPTION OF CHITOSANE GRAFTED ACRYLIC ACID BASED HYDROGEL SWELLING KINETICS AND THEIR USE IN NEW DESIGNED SYSTEM

2021 ◽  
Author(s):  
Tamara Erceg ◽  
◽  
Gaja Brakus ◽  
Dejan Kojić ◽  
Nevena Vukić ◽  
...  
Keyword(s):  
Acrylic Acid ◽  
Room Temperature ◽  
Cost Effective ◽  
Swelling Kinetics ◽  
Swelling Ratio ◽  
Empirical Dependence ◽  
Step Procedure ◽  
Dynamic Swelling ◽  
Hydrogel Swelling

Chitosan based hydrogel was synthesized via free-radical polymerization in a two-step procedure, after modification of chitosan by acrylic acid. Dynamic swelling test was carried out in distilled water at room temperature. Swelling kinetics was modeling using the principle of assuming the equation for a swelling ratio-time empirical dependence. Using regression analysis in this way gives the possibility for simpler determination of swelling ratio-time empirical dependence, knowing the graph functions. Obtained hydrogel was used for preparation of new bilayer hydrogel system which has potential application in wound dressing systems and other fields where pH sensitivity and improved mechanical properties of biopolymers are required in framework of green, cost-effective process.

Strip Cladding of Propeller Shafts with Nickel Alloy 625 by Electroslag Surfacing

1993 ◽  
Vol 9 (03) ◽  
pp. 173-180
Author(s):  
J. H. Devletian ◽  
Y. P. Gao ◽  
Q. H. Zhao ◽  
W. E. Wood
Keyword(s):  
Nickel Alloy ◽  
Room Temperature ◽  
Cost Effective ◽  
Flat Plates ◽  
Alloy 625 ◽  
Silicon Carbon ◽  
Class 1 ◽  
Comprehensive Comparison ◽  
Bend Tests ◽  
Submerged Arc

A comprehensive comparison between electroslag surfacing (ESS) and submerged arc surfacing (SAS) using 30-mm-wide (1.2 in.) χ 0.5-mm-thick (0.020 in.) nickel alloy 625 strip was conducted in both the as-deposited and stress relieved (at 650°C [1200°F]) conditions. In most cases, exactly duplicate cladding conditions were used to best compare ESS with SAS. Nickel alloy 625 strip was deposited on 10-cm-thick (4 in.) flat plates and 64-cm-diameter (25 in.) shafting (both MIL-S-23284 Class 1 steel) using optimized ESS and SAS processes. Tension and face and side bend tests were performed on as-welded and stress-relieved cladding at room temperature. Microstructural analyses of the clad specimens were performed using optical and electron microscopy. Cladding parameters were found to affect the dilution, deposition rate, and penetration. Although ESS and SAS cladding possessed similar strength levels, the cladding deposited by ESS was shown to have greater ductility than that by SAS. Also, the resistance to solidification cracking of cladding by ESS was superior to SAS because of the reduced silicon, carbon, oxygen, and impurity levels which promote interdendritic Laves phase, niobium-rich MC carbides and inclusions. Compared with SAS, the ESS method proved to be not only more metallurgically favorable but also cost-effective.

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