permissible limits
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Author(s):  
Aditya Manivannan Iyer ◽  
Vedika Dadlani ◽  
Harshal Ashok Pawar

Abstract: Acrylamide is classified as a hazard whose formation in carbohydrate-rich food cooked at a high temperature has created much interest in the scientific community. The review attempts to comprehend the chemistry and mechanisms of formation of acrylamide and its levels in popular foods. A detailed study of the toxicokinetic and biochemistry, carcinogenicity, neurotoxicity, genotoxicity, interaction with biomolecules, and its effects on reproductive health has been presented. The review outlines the various novel and low-cost conventional as well as newer analytical techniques for the detection of acrylamide in foods with the maximum permissible limits. Various effective approaches that can be undertaken in industries and households for the mitigation of levels of acrylamide in foods have also been discussed. This review will assist to provide in depth understanding about acrylamide that will make it simpler to assess the risk to human health from the consumption of foods containing low amounts of acrylamide.


Author(s):  
Nadezhda Konstantinovna Maltseva ◽  
Valeriya Olegovna Popova ◽  
Aleksandr Aleksandrovich Syrov

The relevance of the topic of the safety of nuclear refueling operations is associated with the specificity of exploitation of RBMK units. One of the most hazardous, from the perspective of accidents at modern nuclear power plants, is the process of nuclear fuel reloading. The operations on rearrangement of fuel cartridges entail the risk of fuel damage, and thus, the likelihood of the release of radioactive substances exceeding the permissible limits. The process of reloading RBMK, if the reactor is at full capacity, consists of the vast number of complex operations characterized by a range parameters. Non-observance of the criteria for carrying out operations, or if the parameter values exceed permissible limits, with high probability leads to an accident. This article explores the possibility of application of formalized approach towards determination of the baseline events that may cause accidents for the purpose of the development of essential protection instruments. The formal approach would allow detecting the excessiveness in protection instruments on the existing blocks, as well as revealing the accident situations that cannot be prevented using these protection instruments. The author formulated systemic approach towards comprehensive assessment of the accident rate of structurally complex systems. Adaptation of this method relative to REM allows systematizing the search for baseline vents that entail uncontrolled situations, as well as optimizing the protection instruments that would ultimately enhance reliability of the system, simplify the exploitation process, and reduce the time of operating cycle of the controller for processing of the protection.


2021 ◽  
Vol 14 (1) ◽  
pp. 130-141
Author(s):  
U. Bawa ◽  
A. Ahmad ◽  
J.N. Ahmad ◽  
A. G. Ezra

Heavy metals bioaccumulation in agricultural crops fumigated with pesticides has growninto a major concern globally. This study assessed heavy metals concentrations (Cd, Pb, Cr, Cu, Zn) in commonly consumed crops and their corresponding soil from agricultural farm lands in Jos Plateau State, Nigeria. The mean concentrations of heavy metals in the studied crops ranged from 0.17-100.75, 0.17-54.33, 0.83-28.75, 0.17-5.50, 0.5-0.5mg/kg for Zn, Pb, Cu, Cr, and Cd respectively. The trend of heavy metals in the crops were in decreasing order of Zn>Pb>Cu>Cr>Cd and their concentrations varied in different parts of the crops. The mean concentration of Cd, Pb, and Cr in the studiedcrops were above the WHO, (2019) permissible limits and therefore a call for concern. The mean concentrations of heavy metals in the soil varied from 0.5-0.5, 2.50-13.83, 3.67-5.75, 11.83-26.33, and 41-89.50 mg/kg for Cd, Pb, Cr, Cu and Zn respectively and were below the UNEP, (2013) permissible limits for agricultural soil. The result showed that Pb had the highest transfer factor (1.91) in (Capsicum annuum) and Zn had theleast. Similarly, the result revealed high Pollution index value for Pb compared to other metals. Hazard quotient and Hazard index of all the crops were less than 1; thus the consumption of these crops is unlikely to pose health risks to the target population. However, the result showed health risk from daily intake of some of the studied crops for Pb ((Brassica oleracea, Lactucasativus, Zea mays, Spinaciaoleracea, and Capsicum annuum). Hence, regular monitoring and screening of pesticides for heavy metals should be employed by government agencies.


Author(s):  
P. O. Nzenwa ◽  
C. E. Igwe ◽  
U. C. Edward ◽  
C. C. Obasi ◽  
N. E. Okwodu

Borehole water is one of the major sources of potable water in most developing countries of the world. Therefore, it becomes imperative to evaluate the continuing portability of these sources of water to the populace. The present study was undertaken to appraise the water quality of selected boreholes in Owerri Metropolis using the water quality index (WQI) method. Samples were collected from five different locations under stringent protocols. The water samples were analyzed for selected physicochemical properties and compared with WHO permissible limits and American Public Health Association. Results showed that the assayed parameters were within WHO permissible limits except Turbidity in Locations 2, 3 and 4. Water quality index ranged from 24.91 to 70.06. This study revealed that the investigated borehole waters are mostly portable and can be consumed. Nonetheless, the sources identified to be of poor quality should be treated before consumption.


2021 ◽  
Vol 25 (2) ◽  
pp. 461-481
Author(s):  
Denis A. Dobryakov ◽  
Ilda Kasa ◽  
Yuliia V. Sukhostavskaya

By now (we mean 2020) digitalization has completely replaced the more general modernization and innovation from both the political vocabulary and the sci-entific agenda. It is difficult to say how long this trend will continue and what kind of socio-technological phenomenon will replace it. It can be cyberization, within which a person will begin to bring himself into line with the canons of the sci-fi cyberpunks and combine biological with technological (and digital at the same time) in his body, or vice versa, some kind of reactionary naturalization. Anyway, now the widespread adoption of digital technology is an indisputable and obvious fact. And this process applies to all spheres of societys life, without bypassing legal proceedings and out-of-court settlement of disputes (or in other words - alternative dispute resolution), which can be significantly improved using digital technologies. This article analyses the practice and legislative regulation of the use of digital technologies in various forms of legal proceedings and such types of out-of-court dispute resolution as arbitration and mediation. Comparative legal method allowed to compare Russian and foreign legislations as well as approaches to determining the permissible limits of the use of digital technologies, including their intellectual variety. Individual proposals have been formulated to improve Russian legislation.


2021 ◽  
Vol 13 (24) ◽  
pp. 13719
Author(s):  
Aso H. Saeed H. Salih ◽  
Abdullah A. Hama ◽  
Karzan A. M. Hawrami ◽  
Allah Ditta

Land snails are crucial consumers in the terrestrial environment and beneficial significant bioindicators to evaluate the chemical impact in the ecosystem, especially on urban lands. The present study aimed to investigate the concentration of heavy metals such as As, Cr, Ni, Pb, and Zn in urban soil and study whether Eobania vermiculata acts as a bioindicator for heavy metal contamination in an urban area. Thirty soil and snail samples in triplicate from each sampling site were taken from the urban areas of Suliamani. After a microwave-assisted digestion procedure, every sample was analyzed by inductively coupled plasma-optical emission spectrometry. Results showed that the concentration of chromium (Cr) in each snail sample was significantly high. The maximum Cr concentration (15.87 mg kg−1) was recorded in the snail sample collected from Ali Kamal Park, which was adjacent to a very crowded traffic road. The As concentration in snail samples ranged from 0.08 to 1.004 mg kg−1, and it was below the permissible limits. However, the concentrations of heavy metals in urban soil locations were below their background measurements, except for nickel (Ni) which was above the permissible limits. The safest site in the study area was Chaviland 1, while the most contaminated site was the Ha-wary Shar Park. The snails bioaccumulated metals in their tissues in the following order, Cr > Zn > Ni, and this bioaccumulation occurred more on the main road locations, which represented potentially contaminated places due to anthropogenic activities. Moreover, there was no correlation among the heavy metals within the soil samples when compared to the similar metals in the snail samples, due to the low concentration of heavy metals in soil, excluding Ni, from where the snail samples were collected. Consequently, the land snail, E. vermiculata, is an appropriate sentinel organism for some metals, mainly for Cr, and the bioindicator monitoring with this snail should be extended to mixtures of heavy metals, since such relationships frequently occur in soil.


Toxins ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 870
Author(s):  
Kingsley O. Omeje ◽  
Benjamin O. Ezema ◽  
Finbarr Okonkwo ◽  
Nnenna C. Onyishi ◽  
Juliet Ozioko ◽  
...  

More still needs to be learned regards the relative contamination of heavy metals and pesticide residues, particularly those found in widely consumed Nigerian food crops like cereals, vegetables, and tubers. In this current study, the heavy metals and pesticide residues detectable in widely consumed Nigerian food crops were respectively quantified using atomic absorption spectroscopy (AAS) and gas chromatography (GC). Specifically, the widely consumed Nigerian food crops included cereals (rice, millet, and maize), legume (soybean), tubers (yam and cassava), as well as leaf (fluted pumpkin, Amaranthus leaf, waterleaf, and scent leaf) and fruit vegetables (okro, cucumber, carrot, and watermelon). Results showed that the detected heavy metals included arsenic (As), cadmium (Cd), chromium (Cr), cobalt (Co), iron (Fe), lead (Pb), manganese (Mn), mercury (Hg), and nickel (Ni), whereas the pesticide residues included Aldrin, Carbofuran, g-chlordane, Chlorpyrifos, DichloroBiphenyl, Dichlorodiphenyldichloroethane (DDD), Dichlorodiphenyltrichloroethane (DDT), Dichlorvos, Endosulfan, Heptachlor, Hexachlorobenzene (HCB), Isopropylamine, Lindane, t-nonachlor, and Profenofos. Across the studied food crops, the concentrations of heavy metals and pesticides were varied, with different trends as they largely fell below the established maximum permissible limits, and with some exceptions. Our findings suggest there could be a somewhat gradual decline in the concentration of the heavy metals and pesticide residues of these studied food crops when compared to previously published reports specific to Nigeria. To help substantiate this observation and supplement existing information, further investigations are required into the concentration of these heavy metals and pesticide residues specific to these studied food crops at other parts of the country.


Author(s):  
Omar Farhan Al-Hardanee ◽  
İlyas Çankaya ◽  
Abdulmuttalib A. Muhsen ◽  
Huseyin Canbolat

The core of a typical hydroelectric power plant is the turbine. Vibration and overheating in a turbine occur when water flows through it, and with increased vibration and high temperature, it will cause the turbine blade to break. In this study, the control and monitoring system is designed to predict and avoid any error before it occurs. This process is achieved by measuring vibration and temperature using sensors and sending signals through the Arduino to the graphical user interfaces (GUI), the system compares the signals taken from the sensors with the permissible limits, and when the permissible limits are exceeded, the processor takes appropriate measures to open and close the turbine gates, where the data is displayed in matrix laboratory graphical user interfaces (MATLAB’s GUI) screen. In this way, monitoring is done, and the appropriate action are taken to avoid mistakes.


Coatings ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1441
Author(s):  
Vitaliy V. Savinkin ◽  
Zaure Zh. Zhumekenova ◽  
Andrei Victor Sandu ◽  
Petrica Vizureanu ◽  
Sergey V. Savinkin ◽  
...  

The relevance of this study lies in the need to research the wear process of the elements of dynamic systems and to establish the dependence of the geometric and structural characteristics of wheels restored by plasma surfacing with a coating of 15Cr17Ni12V3F on dynamic, cyclically varying loads. The study was aimed to establish the dependencies between the deviation of the wear area, the formation of contact and fatigue stresses, and the change in the phase structure of the wheel defect. It is important to justify the permissible limits of wear of the transverse profile in the contact zone of a wheel and ridge. The object of the study was the dynamic interaction of the “wheel–ridge–rail contact surface” system. To achieve the goal, the following methodology was adopted: kinematic analysis, strength calculation, the use of mathematical analysis in dynamic system modelling, virtual modelling in the SOLIDWORKS software environment of the GearTrax application, experiment planning, and model correction through the results of metallographic studies. The results of the study are presented as reasonable prediction criteria that consider contact cycles during the formation of fatigue stresses at the stage of defect origin. The process of the dynamic interaction of the contact worn profile of a wheel with a railway rail is explored. Polynomial equations are proposed to substantiate the optimal design and technological parameters of designing a railway carriage wheel. The permissible limits of wear of the transverse profile in the contact zone of the wheel and the ridge are justified while taking the coefficient of the reduction of contact stresses in the metal into account. The dependences of the change in static load on the utilization factor of the railway carriage load capacity are established. The dependences of changes in fatigue stresses on the design deviation of the contact area of wheel wear are established. It is confirmed that the stress concentration under cyclic loads is formed in the ferritic layers of the material structure before the appearance of wear.


Author(s):  
Abdullahi A. Mundi ◽  
Idris M. Mustapha ◽  
Rabo Maikeffi

In this study, assessment of outdoor background exposure levels in some selected swampy agricultural soil in Nasarawa West, Nigeria has been conducted. An in-situ measurement of outdoor background exposure rate (in mRhr-1) for a total of fifty farms (ten each from Keffi (KF), Kokona (KK), Karu (KR), Toto (TT), and Nasarawa (NS))  were  done  using  a  well  calibrated  portable  halogen-quenched  Geiger  Muller  (GM)  detector (Inspector alert Nuclear radiation monitor SN:3544). A geographical positioning system (GPS) was used at an elevation of 1.0 m above ground level to obtain the geographical location.  The radiological hazard parameters were evaluated using the measured outdoor background exposure rates.  The values obtained were compared with recommended permissible limits to ascertain the radiological hazard status of the swampy agricultural farms.  The  mean  values  of  the  outdoor  background  exposure  levels (0.23, 0.038, 0.028, 0.022, and 0.039 mRh-1), absorbed dose rates (458.49, 334.95, 188.79, 194.01,  and 343.65 nGyh-1) and excess lifetime cancer risk (1.968, 1438, 0.810, 0.832, and 1.475)  each for KF, KK, KR, TT, and NS respectively, are higher than the  recommended  safe  limits  of  0.013  mRh-1,  84.0  nGyh-1,  0.00029 respectively  as  recommended by UNSCEAR and ICRP. On the other hand, the mean annual effective dose equivalent (AEDE) values (0.563, 0.410, 0.232, 0.238, and 0.421 mSvy-1 for KF, KK, KR, TT, and NS respectively) are below the recommended permissible limits of 1.00 mSvy-1 for general public exposure. Generally, the study revealed that swampy agricultural soils in Nasarawa west are radiologically safe with little contamination which could be attributed to the geological formation and partly due to human activity in the area.


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