scholarly journals Factors affecting the cesium transfer factor to shiitake (Lentinula edodes) cultivated in sawdust medium

2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Masakazu Hiraide

AbstractThe transfer factor (TF) of radioactive cesium-137 (137Cs) to shiitake (Lentinula edodes) cultivated on bed logs varies greatly. Therefore, the present study investigated which factors affect the TF using stable cesium-133 (133Cs) and sawdust medium with 5% rice bran as a model, which had similar 133Cs TFs to bed-log cultivation. It was found that the Cs concentration and nutrient concentration (represented by the nitrogen concentration) concerned with the TF in the model sawdust medium. In addition, the TFs calculated using total 137Cs and 133Cs concentrations differed in both bed-log cultivation and the model sawdust medium cultivation, while the TFs calculated using exchangeable 137Cs and 133Cs concentrations were the same in sawdust medium cultivation, indicating that exchangeable Cs in the medium is the source of Cs for the fruiting body and the former difference was due to the presence of other chemical speciation of Cs that could not be absorbed. One purpose of the TF on the mushroom farm is to determine the fruiting body 137Cs concentration at the start of bed-log cultivation, therefore the prediction method of TF are discussed considering the future changes of 137Cs concentrations in trees.

2020 ◽  
Vol 108 (10) ◽  
pp. 799-808
Author(s):  
Mostafa M. Hamed ◽  
Mahmoud M. S. Ali ◽  
Aly A. Helal

AbstractRemoval of 137Cs radionuclides from the environment has engrossed the concern of researchers after Fukushima accident. The leakage of radioactive cesium ions can lead up to surface and groundwater contamination, and this leads to pollution of drinking water sources. In this work, corchorus olitorius stalks has been used as a novel precursor for production of low-cost mesoporous activated carbon (Meso-AC) and HNO3/H2O2-modified Meso-AC (m-Meso-AC). The physicochemical properties of all adsorbents were evaluated. The influences of sorption parameters and presence of some ligands (humic acid, fulvic acid, and EDTA) on the sorption of 137Cs were studied. The maximum 137Cs capacity of m-Meso-AC was found to be 58.74 mg/g. Efficiency of the new adsorbent to remove 137Cs radionuclides from natural waters (tap, river, and groundwater) was investigated. The studies showed that new adsorbent could be used as promising material for the retention of 137Cs from real radioactive waste and natural water samples.


2017 ◽  
Vol 12 (1) ◽  
pp. 87-96 ◽  
Author(s):  
J. S. Hyung ◽  
K. B. Kim ◽  
M. C. Kim ◽  
I. S. Lee ◽  
J. Y. Koo

Ozone dosage in most water treatment plants is operated by determining the ozone concentration with the experience of the operation. In this case, it is not economical. This study selected the factors affecting residual ozone concentration and attempted to estimate the optimum amount of hydrogen peroxide dosage for the control of the residual ozone concentration by developing a model for the prediction of the residual ozone concentration. The prediction formulas developed in this study can quickly respond to the environment of water quality and surrounding environmental factors, which change in real time, so it is judged that they could be used for the operation of the optimum ozone process, and the control of ozone dosage could be used as a new method in controlling the concentration of ozone dosage and the concentration of residual ozone.


2010 ◽  
Vol 44-47 ◽  
pp. 3403-3407
Author(s):  
Fei Yue Wang ◽  
Zhi Sheng Xu ◽  
Long Jun Dong

Due to the extremely complicated seepage boundary conditions of tailing dam, the calculation results adopting two-dimensional simplified theory may greatly different from the measured results. It is urgent need of an accurate calculation method to forecast phreatic surface. In-depth analysis of factors affecting tailings dam phreatic surface, phreatic surface prediction model based on GRNN and GM (1,1) was established. A tailing dam engineering is tested using this model. It shows that the model uses the advantages of "accumulative generation" of a Gray prediction method, which weakens the original sequence of random disturbance factors, and increases the regularity of data. It also makes full advantage of the GRNN approximation performance, which has a fast solving speed, describes the nonlinear relationship easily, and avoids the defects of Gray theory.


2019 ◽  
pp. 47-52
Author(s):  
Alexander Mikhailovich Okunev

The degree of contamination of the organism of wild animals with radionuclides is of particular importance in the framework of environmental monitoring and assessment of its safety, both for humans and for animals. However, the majority of domestic scientific works on this subject concerns farm animals, and the information relating to hunting animals is much less. This fact determined the relevance of our work, the purpose of which was to study the features of the accumulation of global technogenic and natural radionuclides in the meat of some wild animals in the TRANS-Urals. Experimental data on the content of technogenic radionuclides in the meat of hunting animals were obtained in the autumn-winter periods of 2014 – 2018. Analysis of the average data showed, that the content in the meat of wild animals cesium-137, depending on the animal species, ranged from 4.1 to 49.2; lead-210 – 0,7 – 4,3; and strontium-90 – 0,1 – 1,7 Bq/kg. The total beta- activity of radionuclides in the meat of wild animals varied, depending on the species, from 71.2 to 104.3 Bq/kg. At the same time, all the studied samples of meat corresponded to the norms established by SanPiN-2010 for this type of food product. Some increased accumulation of radioactive cesium (49.2 Bq/kg) and other anthropogenic radionuclides was observed in wild reindeer meat, and in the southern regions of the TRANS-Urals – in bear and wild boar meat (21.1 and 17.4 Bq/kg, respectively). In the muscle tissue of the roe deer the content of this radionuclide was slightly higher than that of the elk (14.7 and 12.2 Bq/kg, respectively). The lowest concentration of cesium-137 (4.1 Bq/kg) and other nuclides was found in beaver meat. The content of strontium-90 in the meat of all tested animals was at a minimum level, and the specific activity of lead-210 was higher than strontium-90 by 2 - 10 times, depending on the species, which indicates the accumulation of this radionuclide in forest ecosystems due to anthropogenic pressure and expansion of the technogenic zone of cities.  The results of studies have shown that differences in the accumulation of technogenic radionuclides in the meat of the hunting animals are largely related to the nature of feeding and composition of the diet of wild species, and are subject to significant fluctuations in accordance with the change in the volume and qualities of food resources in forest biotopes over the year.      


Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1530
Author(s):  
Muhammad Shahid Anwar ◽  
Jing Wang ◽  
Sadique Ahmad ◽  
Asad Ullah ◽  
Wahab Khan ◽  
...  

360-degree Virtual Reality (VR) videos have already taken up viewers’ attention by storm. Despite the immense attractiveness and hype, VR conveys a loathsome side effect called “cybersickness” that often creates significant discomfort to the viewers. It is of great importance to evaluate the factors that induce cybersickness symptoms and its deterioration on the end user’s Quality-of-Experience (QoE) when visualizing 360-degree videos in VR. This manuscript’s intent is to subjectively investigate factors of high priority that affect a user’s QoE in terms of perceptual quality, presence, and cybersickness. The content type (fast, medium, and slow), the effect of camera motion (fixed, horizontal, and vertical), and the number of moving targets (none, single, and multiple) in a video can be the factors that may affect the QoE. The significant effect of such factors on end-user QoE under various stalling events (none, single, and multiple) is evaluated in a subjective experiment. The results from subjective experiments show a notable impact of these factors on end-user QoE. Finally, to label the viewing safety concern in VR, we propose a neural network-based QoE prediction method that can predict the degree of cybersickness influenced by 360-degree videos under various stalling events in VR. The performance accuracy of the proposed method is then compared against well-known Machine Learning (ML) algorithms and existing QoE prediction models. The proposed method achieved a 90% prediction accuracy rate and performed well against existing models and other ML methods.


2015 ◽  
Vol 78 (3) ◽  
pp. 561-566 ◽  
Author(s):  
MAYUMI HACHINOHE ◽  
TOMOYA OKUNISHI ◽  
SHOJI HAGIWARA ◽  
SETSUKO TODORIKI ◽  
SHINICHI KAWAMOTO ◽  
...  

We investigated the distribution of cesium-134 (134Cs) and cesium-137 (137Cs) during polishing and cooking of rice to obtain their processing factors (Pf) and food processing retention factors (Fr) to make the information available for an adequate understanding of radioactive Cs dynamics. Polishing brown rice resulted in a decreased radioactive Cs concentration of the polished rice, but the bran and germ (outer layers) exhibited higher concentrations than brown rice. The Pf values for 100% polished rice and outer layers ranged from 0.47 to 0.48 and 6.5 to 7.8, respectively. The Fr values for 100% polished rice and outer layers were 0.43 and 0.58 to 0.60, respectively. The distribution of radioactive Cs in polished rice and outer layers was estimated at approximately 40 and 60%, respectively. On the other hand, cooked rice showed significantly lower levels of radioactive Cs than polished rice, and transfer of radioactive Cs into wash water was observed. The Pf and Fr values for cooked rice were 0.28 and 0.65 to 0.66, respectively. From these results, we can calculate that if the radioactive Cs concentration in brown rice is 100 Bq/kg, the concentrations of Cs in polished rice and cooked rice will be 47 to 48 Bq/kg and 13 Bq/kg, respectively.


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