Possibility of application nuclear magnetic resonance for measurement of fluid-flow

The paper considers the application of nuclear magnetic resonance for measurement of fluid-flow. The paper is of an experimental nature. Flowmeter based on nuclear magnetic resonance is extremely precise. The combined measurement uncertainty can be 0.1 %. Such a value of measurement uncertainty indicates that it is a matter of a deterministic and not of a stochastic quantity. This high degree of reliability of the method is theoretically and mathematically described. The paper presents a measurement scheme for flow measurement. Water flow measurement was performed on the principle of nuclear magnetic resonance and on the basis of tritiated water (which is considered to be the most accurate classical method). The obtained results show that the measurement of flow based on nuclear magnetic resonance is more accurate (especially at higher flow). This is explained by the higher inertial mass of HTO tritiated water molecules than the standard H2 O mass and the possible transition of tritiated water to H3HeO. In this way, it has been proven that tracing water based on nuclear magnetic resonance is the only real tracing of water by water. The obtained results show that tracing water with tritiated or heavy water is not tracing water by water which is explained by different inertial masses

Health Risks associated with residual pesticide levels in fish reared in purified wastewater from slaughterhouse

ΔΕΝ ΔΙΑΤΙΘΕΤΑΙ ΠΕΡΙΛΗΨΗThe main objective of the present research was to determine the concentrations of the selected pesticides in muscle, liver and skin of common carp. Fish were sampled in two different seasons from fish pond which received previously treated slaughterhouse wastewater. Pesticides including etridiazole, chloroneb, trifluralin, propachlor, chlorothalonil, hexa-chlorocyclopentadiene, atrazine, simazine, alachlor, metribuzin, metolachlor, DCPA, cyanazine, chlorobenzilate, endrin aldehyde, cis permethrin and trans permethrin were determined by using a GS-MS method. Many of pesticides were not determined or determined in low concentrations. Propachlor was found in muscle, skin and liver. The recommended acceptable daily intake was higher in comparison with the estimated daily intake for examined pesticides via fish reared in treated slaughterhouse wastewater. It is very important to maintain the safety of the fresh fish produced in wastewater in order to ensure food safety and avoid health problems in humans

Passive and active shielding against electromagnetic radiation

In nuclear physics experiments, it is very important to isolate the measured quantities from electromagnetic noise. Without this possibility, it is impossible to obtain usable experimental results since natural electromagnetic noise can be several orders of magnitude larger than the measured magnitude. In order to enable such measurements, it is necessary to eliminate electromagnetic noise from the experimental procedure. This is achieved by shielding against electromagnetic radiation. In this paper, experiments were performed to protect a room from electromagnetic noise. By applying all known methods of shielding against electromagnetic radiation, it was concluded that the room can be protected from the electrical component, but it is impossible to protect it from the magnetic component of electromagnetic radiation

In fluence of gamma radiation on Josephson junction

Quantum mechanics consideration, supported by a concrete example, yielded standard sources of di rect volt age mea sured by frequency (which is the most ac cu rate measur able phys-ical quantity) and extremely sensitive instrument for measuring magnetic induction SQUID (which is an ac ro nym based on the term Supercon duct ing Quan tum Inter fer ence Device). The pos sibility of these mea sure ments is based on the Josephson junc tion. In this paper, the in flu ence of gamma ra diation on the mea sure ment un cer tainty Type A, of a com mercial Josephson compound, is investi gated. The conclu sion is that both dy namic gamma radiation and the dose of gamma ra di ation, un der the con ditions of the ex per iment, have a neg ligible ef-fect on the mea sure ment uncer tainty of the Josephson junc tion. Based on the ob tained re sult, it was con cluded that in the primary metrological con di tions, the mea sure ment un cer tainty type A of the Josephson junc tion is neg ligible, i. e., that the secondary cosmic radiation does not af fect the stan dard of the DC volt age source. © 2021, Vinca Inst Nuclear Sci. All rights reserved

Evaluation of ELISA tests as screening methods for determination of antibiotics and sulfonamides in honey

The health safety of honey includes the correctness in terms of the presence of different contaminants, which also implies the antibiotic residue. The presence of antibiotics in honey is prohibited, and methods of food analysis are prescribed in order to reliably determine antibiotics in food. In this paper the application of ELISA tests for determination of selected antibiotics and sulfonamides in honey is shown. The possibility of using four ELISA tests for the analysis of tetracyclines, streptomycines, chloramphenicol and sulfonamides was examined. Each test was evaluated after application on honey samples spiked with standard solution of a particular analyte. Samples were prepared according to the instructions of the ELISA test manufacturer referring to honey. Results of investigation of all ELISA tests, except for sulphonamides, have shown satisfactory accuracy (73-111%) and precision (14-16%). Recovery for sulfametoxypyridazin was low (40%), and for low tetracycline concentration was somewhat higher than acceptable (139%). The detection limits were in accordance with the limits given by the ELISA kit manufacturer and are also satisfactory in relation to the requirements of the legislation (0.075-3 μg/kg). The test kits can be used to screen the presence of tetracycline, chloramphenicol and streptomycin in the honey, taking into account the obtained validation parameters

Design of capacitive voltage divider for measuring ultrafast voltages

The aim of this paper is to consider and analyze design of capacitive voltage divider for measuring ultrafast voltage occurrence. Measuring pulse voltages by means of a capacitive divider in nanosecond range is affected by problems related to the construction of the divider and materials used. However, an appropriate constructive solution could minimize the budget of measuring uncertainty of the measurement pertaining to parasitic inductivity and capacitance. Consequently, the right selection of dielectric materials could offset the effects of high-voltage and low-voltage frequency characteristics of the capacitor. Four types of capacitive dividers have been constructed for the purpose of this paper. The high-voltage capacitor of each divider is a gas capacitor (intended to avoid both electrostatic and electrodynamic influence on measurement uncertainty). Ultrafast pulse response is measured by dividers constructed in this way, and compared with the corresponding response obtained from numerical simulations

Numerical modeling of partial discharges parameters

In recent testing of the partial discharges or the use for the diagnosis of insulation condition of high voltage generators, transformers, cables and high voltage equipment develops rapidly. It is a result of the development of electronics, as well as, the development of knowledge about the processes of partial discharges. The aim of this paper is to contribute the better understanding of this phenomenon of partial discharges by consideration of the relevant physical processes in isolation materials and isolation systems. Prebreakdown considers specific processes, and development processes at the local level and their impact on specific isolation material. This approach to the phenomenon of partial discharges needed to allow better take into account relevant discharge parameters as well as better numerical model of partial discharges

Design of capacitive voltage divider for measuring ultrafast voltages

The aim of this paper is to consider and analyze design of capacitive voltage divider for measuring ultrafast voltage occurrence. Measuring pulse voltages by means of a capacitive divider in nanosecond range is affected by problems related to the construction of the divider and materials used. However, an appropriate constructive solution could minimize the budget of measuring uncertainty of the measurement pertaining to parasitic inductivity and capacitance. Consequently, the right selection of dielectric materials could offset the effects of high-voltage and low-voltage frequency characteristics of the capacitor. Four types of capacitive dividers have been constructed for the purpose of this paper. The high-voltage capacitor of each divider is a gas capacitor (intended to avoid both electrostatic and electrodynamic influence on measurement uncertainty). Ultrafast pulse response is measured by dividers constructed in this way, and compared with the corresponding response obtained from numerical simulations

Reliability of computer memories in radiation environment

The aim of this paper is examining a radiation hardness of the magnetic (Toshiba MK4007 GAL) and semiconductor (AT 27C010 EPROM and AT 28C010 EEPROM) computer memories in the field of radiation. Magnetic memories have been examined in the field of neutron radiation, and semiconductor memories in the field of gamma radiation. The obtained results have shown a high radiation hardness of magnetic memories. On the other side, it has been shown that semiconductor memories are significantly more sensitive and a radiation can lead to an important damage of their functionality. [Projekat Ministarstva nauke Republike Srbije, br. 171007

Lifetime characteristics of Gaiger-Muller counters

This paper discusses the process of functional aging of Geiger-Muller counters. Two types of Geiger-Muller counter chambers were characterized in an experiment using a combined constant voltage. Chamber A had a coaxial geometry and chamber B had a plan-parallel geometry. The experimental results indicate that the aging process was faster in the case of chambers with a coaxial geometry. The results are explained based on the process of electrical discharges in gasses