Zone Of Radiation Research Articles

Approaches for improvement of reliability of the Prony’s method computation

Parametric spectral analysis methods such as the Prony’s method can estimate the frequencies and amplitudes of a signal, conforming to their model, with great precision. At the same time, the addition of noise to the signal can lead to a complete model breakdown which leads to erroneous parameter values. This is especially true for the impulse noise. The article explores several possible algorithms which can be applied to the Prony’s method in order to refine the results and make them more noise resistant. Such algorithms include signal segmentation methods where the results of each segment processing influence the final estimate as well as the conceptually related method of point skipping. An approach based on the use of non-Euclidean norms as a measure of the linear algebraic equation system’s solution quality is developed and tested. Initially, the methods are applied to model digital signals, comprised of harmonic components with varying complex frequencies and amplitudes. Additive white Gaussian and impulse noise is added to the model signals. The results are then applied to the noisy results of a real-life synthetic aperture synthesis experiment obtained in the intermediate zone of radiation.

Substantiation of the Possibility to Use the Electromagnetic Shields Based on Powdered Aluminum Oxides to Reduce the Electromagnetic Radiation Energy of Electronic Devices

The article introduces the results of the experimental substantiation of the possibility to use the electromagnetic shields based on powdered aluminum oxides to reduce the electromagnetic radiation energy introduced by electronic devices. To achieve this goal, a methodology has been developed for assessing the effect of materials on the electromagnetic radiation level of electronic devices, and a methodology for estimating the radius of the controlled zone of the secondary electromagnetic radiation of computer equipment has been systematized. In accordance with the indicated methods, the study has been carried out, based on the results of which it was determined that electromagnetic shields containing the composite coating based on powdered aluminum oxides and iron oxide provide suppression of the electromagnetic radiation energy of electronic devices, as well as a reduction of up to 2 times the radius of the controlled zone of the secondary electromagnetic radiation of computer equipment. Recommendations for the practical application of the composite coatings based on the powdered alumina and iron oxide have been developed. In accordance with these recommendations, such coatings can be used in the process of manufacturing or improving the technical and functional properties of electromagnetic shields designed to ensure the electromagnetic compatibility of electronic devices, as well as to solve problems related to the information security.

Fire and Explosion Consequence Analysis of Occupied Buildings in an LPG Storage Facility in Southern Nigeria

The purpose of this work was to carry out an evaluation of occupied buildings from the devastating impact of an explosion in a Liquefied Petroleum Gas (LPG) bulk storage facility with the intention to provide information on blast requirements of the buildings and make layout modification as needed using the consequence-based approach. The simulation was done using DNV’s Process Hazard Analysis Software Tool (PHAST) and the process data were obtained from a process plant located in the Niger-Delta region of Nigeria. Three major scenarios; catastrophic rupture, full bore rupture was considered for a 6-inch pipe and fixed duration release of the stored LPG and propane gas using the TNO multi-energy method to determine the Maximum Credible Event on the occupied buildings within the facility From the study, the catastrophic rupture of LPG vessel #18 at 2/F weather category gave the worst impact with an overpressure effect of 0.7barg at a hazard distance of 166.959m. The thermal radiation intensity of 37.5KW/m2 due to Jet fire from the fixed duration release of Propane vessel #22 at 2/F weather category was found to produce the greatest consequence/impact at a hazard distance of 180.72m. The results from this work show that most of the occupied buildings within the location are in the vicinity of the effect zone of both explosion overpressure and Jet fire thermal radiation.

EMITTANCE MEASUREMENT OF THE ACCELERATED BEAMS (A REVIEW)

A review of emittance measurement methods of the accelerated (ionic or electronic) beams on various accelerating facilities both foreign, and Ukrainian is presented. There are some ways of emittance measurements in their various modifications: a slit method ("two slits", "four slits", Allison scanner), pepperpot method, and also gradient method (quadrupole scanning). The most high-speed and exact enough way of emittance measurement what is pepperpot method in detail considered on example UNILAC GSI (Darmstadt, Germany). Possibility of a field angular distribution use in a distant zone of an optical diffraction radiation made electronic bunch, passing through rectangular apertures in screens (DESY, Hamburg, Germany) is shown.

REVIEW OF RESEARCH OF THE INFLUENCE OF THE ELECTROMAGNETIC FIELD ON HUMAN WORKING WORK AND DEVELOPMENT OF METHODS OF ELECTROMAGNETIC WAVE SCREENING

This article discusses the issues of life safety of living objects under conditions of constant influence of an electromagnetic field on them. A planned laboratory facility for further research has been proposed. The mathematical apparatus of the generated electromagnetic field by the traction electric motor by the rolling stock of electric transport is shown. Conclusions are made that suggest the creation of special protective clothing for everyday use by humans with a constantly acting electromagnetic field in a man-made environment. Modern man is constantly in the zone of electromagnetic radiation, the influence of which cannot be avoided. Only by minimizing radiation by avoiding areas with increased electromagnetic activity and developing modern means of protection can ensure a safe and harmonious stay of a person in a modern technogenic environment of existence. If we turn to statistics and analyze the issue of the impact of electromagnetic radiation on the human body and study the problems that arise after its negative influence, we will find that almost all human systems and organs are negatively influenced with destructive consequences. This article discusses the latest developments in the field of electromagnetic waves on the human body. The most actual problems connected with work of electric transport as the technogenic environment are analyzed. The mathematical apparatus and the equation of the electromagnetic field for the electric motor are offered to create the mathematical models showing dependence of growth of an electromagnetic field depending on operating modes of the vehicle and places of stay of the passenger in vehicle interior. Еlectromagnetic radiation in the form of clothing, which will allow a comfortable and safe stay of people in a new man-made environment.

UV radiation dose in real time with a cryogenic SiPM using Monte Carlo-Geant4 simulation

At the moment, there is no method that allows the user to calculate the dose of UV radiation during the liquid nitrogen (LN2) sterilization process while complying with quality control regulations. This article describes a simulating method using Geant4 to obtain the dose of UV radiation in real-time with a cryogenic Silicon PhotoMultipliers (SiPM) inside the LN2 container. The results present the zone of minimum UV radiation and the estimation of the radiation dose with a cryogenic SiPM, located in the minimum zone to certify the absence of microorganisms in the LN2.

ASSESSMENT OF THE IMPACT OF ELECTROMAGNETIC RADIATION IN LOW-FREQUENCY ENERGY FACILITIES ON THE RESIDENTIAL ECOLOGICAL ZONE

Nowadays, one of the key issues in the ecological field and environmental protection is the influence of the electromagnetic field distribution intensity generated by low-frequency energy objects on the urban system. The purpose of environmental monitoring is to establish sanitary protection zones, taking into account the necessary maximum permissible conditions, during the construction and commissioning of new energy facilities. The agglomeration environment of the Shymkent city in the Republic of Kazakhstan where there is an increased electromagnetic pollution propagation generated by 110 and 220 kV high-voltage lines has been taken as the object under study. At the initial stage, the geometric parameters of power transmission lines have been determined by ground-based laser scanning and were later used in the main calculations to determine the electric and magnetic field distribution intensity. The mirror image method has been used to determine the electric and magnetic field levels in high-voltage transmission lines. As a result of the calculations obtained a geoinformation map was constructed based on the gradient of electric and magnetic fields in the studied territories using the inversely weighted distance method with the use of the ESRI ARC Gis application program. A three-dimensional characteristic is constructed that visually shows the dependence of the time spent by people in the zone of electromagnetic radiation, which depends on the radiated object. This characteristic is a sanitary protection zone that restricts the routing of line workers.

Effect of vibrating feeder pan geometry on radiometric separator performance

The article offers justifies the optimized shape for the vibrating feeder pan of a radiometric separator, which ensures the maximum travelling speed and uniform flow of ore material in the zone of radiation and recording. Three shapes of pans are discussed: rectangular, parabolic and triangular. It is found that motion of ore material along an inclined rectangular-shape pan is straight-linear. Distribution of ore particles along the width of the channel, which governs the scatter of the motion trajectories relative to the central axis of the channel, depends on the runoff point of particles from the outlet feeder. Proposed for the description of the motion trajectory of ore particles along an inclined channel of parabolic shape, the mathematical model demonstrates the curved and pendulum-wise motion of an ore particle with the attenuating amplitude. The motion of an ore particle in an inclined pan with the triangular-shape channel features the minimized scatter of motion trajectories relative to the central axis of the channel. The analysis of ore motion along vibrating feeder pans with different shape channels is carried out in Rocky DEM environment with regard to interaction of ore particles with the pan surface and with each other. The simulation modeling has proved the conclusions on the efficiency of the triangularshape profile of the vibrating feeder pan as it ensures uniform single-row flow of ore particles along the straight-line trajectory. The triangular shape of the pan contributes to the increased travelling speed of ore particles and, accordingly, to the enhanced capacity of the separator. The radiometric separator efficiency can be increased 1.5 times by changing from the parabolicshape channels to the triangular-shape profiles of vibrating feeder pans at the other operating conditions of radiometric separators being equal.

Formation of CrxCyOz Coatings under Laser Treatment of Chromium Carbide Ceramics

The effect of the pulsed laser irradiation in air on Cr23C6 ceramic with Cr3C2 and Cr7C3 additives has been studied. It is established that the main process occurring in the zone of laser radiation is the melting of the ceramic surface of chromium carbide and the formation of a crater. This process is accompanied by the ejection of melt droplets from the crater zone and the dissociation of chromium carbides. As a result, the crater area is enriched in such ablation products as Cr, C, CO, and CO2. Reduction of hydrogen in the crater zone and neighboring areas leads to slowing down of the rate of oxidation processes, and the presence of ablation products such as Cr and C atoms promotes the process of synthesis of oxycarbides CrxCyOz (x ≈ 0.3–0.8, y ≈ 0.03–0.3, z ≈ 0.61–0.26) in the gas phase. Emission of the newly formed products of ablation from the crater and their distribution to the neighboring areas is accompanied by coagulation of nanoparticles into clusters. Depending on the length of flight of nanoclusters through different temperature zones and temperature of the deposition surface, oxycarbides with different morphology are formed: from islets (like fractal clusters) to film ones. The deposited ablation products are characterized by the signs of particle size “separation.” This makes it possible to create films of a given type and purpose. The passage of particles of different sizes through a gaseous medium containing oxygen is accompanied by the oxidation of oxycarbides to Cr2O3.

Improvement of resolution in aperture synthesis in near zone of radiation based on the application of the Prony’s method

Applicability of inverse filtering with evolution control for reconstruction of images obtained by aperture synthesis technique is considered. A horn antenna, which is moved in the transversal direction, is used in order to obtain a 2-dimensional image. Scanned structure consists of one or two similar metaplates. In the latter case the plates are coplanar and their common plane is parallel to the aperture of the antenna. Regularisation coefficients are found with the help of trial and error method. The image of a single plate was used to tune the software. The Prony’s method is tested as a separate way of estimation of the distance between the plates. Both methods are tested for a range of different distances between the plates and between the plates’ common plane and aperture of the antenna. It is shown that inverse filtration tends to provide better results if the scanned object is situated further from the antenna. Said method was proven to be precise enough to distinguish closely-spaced plates. The Prony’s method was proven to provide reliable distance measurements if it was tuned correctly.

On the wave zone of synchrotron radiation.

The extension of the wave zone of synchrotron radiation is studied.

Reconstruction of Radiated Gluteal Defects following Sarcoma Resection with Pedicled Sensate Tensor Fascia Lata Flaps.

Sarcomas of the gluteal region often result in sizable defects following resection that are challenging to reconstruct due to their location, particularly in patients who have received radiation therapy. Reconstruction of these defects has been seldom discussed in the literature. We present two patients with large radiated gluteal defects following sarcoma resection, of which one patient received neoadjuvant radiation and the other received intraoperative radiation therapy. As a result of the resection and radiation, local tissues and recipient vessels were unsuitable for use in reconstruction. A pedicled tensor fascia lata (TFL) flap was therefore performed in both cases, which resulted in durable sensate reconstruction with good functional outcomes and no complications. We believe the pedicled TFL flap represents an important option for the reconstruction of oncologic gluteal defects that provides well-vascularized and sensate tissue from outside the zone of radiation without the need for microsurgical techniques.

Filamentation length of high-power sharply focused femtosecond laser radiation in air. Effect of light beam size

The results of laboratory experiments on measurements of the length and position of the filamentation zone of femtosecond GW laser radiation at wavelengths of 800 and 400 nm propagating in air under conditions of sharp external focusing are presented. Dependencies of the length of the radiation filamentation zone on its initial radius and power are studied. Qualitatively new regularity is obtained, which consists in invariance of the observed length of the beam filamentation under variations in its diameter with the assumption of equality of the initial intensities. The feature is not typical for collimated radiation and is connected with the dominance of geometrical focusing over Kerr self-focusing of a beam during filament formation.

Long-term remission after multiple bone metastases following cervical cancer: A case report

•Multiple bone metastases following cervical cancer was completed resolved.•Metastatic lesions were present within a previously irradiated zone of primary external radiation.•Concurrent chemotherapy and bisphosphonate administration is promising.

Temporal and spatial variations of global solar radiation over the Qinghai–Tibetan Plateau during the past 40 years

Global solar radiation is of great significance to the balance of ground surface radiation, the energy exchange between the Earth’s surface and atmosphere, and the development of weather and climate systems in various regions. In this study, the monthly global radiation recorded at 23 stations over the Qinghai–Tibetan Plateau (QTP) was utilized to estimate global solar radiation (Q) from sunshine duration and to obtain improved fits to the variation coefficients of the monthly Angstrom–Prescott model (APM). The modeling results were evaluated by calculating the statistical errors, including mean bias error, mean absolute error, root mean square error, and mean relative error. We demonstrate that the monthly Q values can be predicted accurately by APM over the QTP. We also assess the variations of Q values at 116 meteorological stations by APM over the QTP during 1961–2000. The analysis shows that the annual mean sunshine duration amounted to more than 3,000 h over the whole plateau, implying promising prospects for economic applications of solar energy. During the past 40 years, the mean global solar radiation has been relatively high in the western QTP, extending northward to the Inner Mongolian Plateau. Although its decadal variations in the QTP and surrounding regions were inconsistent, the anomaly values of global solar radiation were generally positive during the 1960s and 1970s, indicating that the QTP’s global solar radiation has increased during those periods. The anomaly values were negative during the 1980s and 1990s, showing that the plateau’s global solar radiation has decreased during those periods. Global solar radiation over the QTP is negatively proportional to latitude but positively proportional to altitude and relative sunshine duration. Three factors, the sunshine duration, latitude, and altitude, exert great influence on global surface radiation, of which sunshine duration is most significant. A high-variation-coefficient zone of global solar radiation occurred in the western part of the QTP but, on average, the variation coefficient of the plateau’s global solar radiation was only 0.031, suggesting that the variation in global radiation was relatively stable over the whole QTP.

The Medical Association Activity and Pediatric Care after the Earthquake Disaster in Fukushima

On March 11, 2011, a gigantic earthquake struck eastern Japan. Utilities such as electricity, water, gas and telecommunication were interrupted. In Koriyama, the City Hall collapsed and government administration offices had to be moved to a nearby baseball stadium that had been designed to include facilities for use during a pandemic. An operations center was set up in this stadium. As members of the Koriyama Medical Association, we following the disaster protocol and set up our operations center in the Koriyama Medical Care Hospital. One large hospital with 280 inpatients and another hospital with 150 inpatients had been heavily damaged. Transfer of those patients to other hospitals without the use of telecommunications was extremely difficult. Many doctors in member hospitals and clinics went out of their way to cooperate throughout the crisis. Up to 5,000 people from the radiation evacuation zone were rushed to Koriyama. They stayed in schools and community centers, where we provided them with healthcare. Even in Koriyama, which is 60 km away from the Fukushima nuclear power plant, radiation levels were high, especially for the first few weeks. Citizens were advised to stay at home and keep their doors and windows closed. These drastic measures and frequent earthquake aftershocks were very stressful, especially for children. To help prevent children from developing posttraumatic stress disorder (PTSD), a project team composed of various groups caring for children was developed, and this team took action to protect children. Through these efforts we hoped to provide children with an appropriate environment to grow normally, even in a zone of persistent low-level radiation. We demonstrated once again that our members' long history of mutual assistance and cooperation with the administration was the main cornerstone to overcome the crisis.

Remarkable new evidence for island radiation in birds

If island biogeography has a sweet spot, it's where islands generate their own species diversity rather than merely taking on mainland immigrants. In birds and other highly dispersive taxa, however, this 'zone of radiation', may be vanishingly small. Darwin's finches and Hawaiian Honeycreepers are among only a handful of examples of island radiation in birds (Price 2008), suggesting that winged powers of dispersal make sufficient isolation from mainland colonists unlikely, while also hindering speciation within and among isolated islands. Nevertheless, two studies in this issue of Molecular Ecology join a string of other recent analyses suggesting that island radiation in birds remains under-appreciated (see also Moyle et al. 2009; Kisel & Barraclough 2010; Rosindell & Phillimore 2011). Melo et al. (2011) use a phylogenetic analysis of white-eyes on islands in the Gulf of Guinea to identify two previously overlooked island radiations, and reveal replicated adaptive divergence on islands where species occur in pairs. Sly et al. (2011), meanwhile, consider possible explanations for speciation and geographic differentiation within a large island, and find the same type of oceanic barriers that are critical to bird speciation across archipelagos may also contribute to divergence that appears to have occurred within a single island.

A unified model of island biogeography sheds light on the zone of radiation

Islands acquire species through immigration and speciation. Models of island biogeography should capture both processes; however quantitative island biogeography theory has either neglected speciation or treated it unrealistically. We introduce a model where the dominance of immigration on small and near islands gives way to an increasing role for speciation as island area and isolation increase. We examine the contribution of immigration and speciation to the avifauna of 35 archipelagoes and find, consistent with our model, that the zone of radiation comprises two regions: endemic species diverged from mainland sister-species at intermediate isolation and from insular sister-species at higher levels of isolation. Our model also predicts species-area curves in accord with existing research and makes new predictions about species ages and abundances. We argue that a paucity of data and theory on species abundances on isolated islands highlights the need for island biogeography to be reconnected with mainstream ecology.

Millimeter-Wave Transmittance and Reflectance Measurement on Pure and Diluted Carbonyl Iron

Transmittance and reflectance measurements on highly absorbing carbonyl iron materials over a broad millimeter-wave frequency range have been performed. The frequency dependence of the complex dielectric permittivity of a carbonyl iron diluted composite and pure powdered materials has been determined in the millimeter waves for the first time. The measurements have been employed using a free-space quasi-optical millimeter-wave spectrometer equipped with a set of high-power backward-wave oscillators as sources of coherent radiation, which are tunable in the range from 30 to 120 GHz. A significant transmission zone of millimeter-wave radiation at a frequency around 60 GHz has been observed in the transmittance spectra for the carbonyl iron materials.

Fouling Mechanisms in a Laboratory‐Scale UV Disinfection System

The fouling of quartz sleeves surrounding UV disinfection lamps is a perennial problem affecting both drinking water and wastewater applications. The mechanisms of fouling are not fully understood, but factors promoting fouling are believed to include heat, high hardness and/or high iron concentrations, and hydrodynamic forces. The role of UV radiation itself is unclear. The goal of this paper is to attempt to isolate the fouling mechanisms and to provide key information about those induced by UV radiation, using a unique laboratory-scale continuous-flow UV reactor. Its design allowed for irradiated and nonirradiated zones and control of both temperature and UV intensity at the fouling surface. Synthetic wastewater samples were tested with two levels of calcium, iron, phosphorus, and biochemical oxygen demand (as beef broth), and constant levels of magnesium and nitrogen to assess the effects of the four key variables. Average UV fluence before fouling exceeded 35 mJ/cm2, based on collimated beam tests. Foulant accumulation was monitored by UV intensity measurements and by mass and composition of foulant collected after an average of 56 hours of continuous operation. Tests showed that relative UV intensity dropped by as much as 100% when iron was present. Detailed results were assessed and yielded support for the following three UV-induced fouling mechanisms: (a) precipitation of ferric hydroxide [Fe(OH)3], (b) release of calcium from calcium-organics complexes followed by precipitation of iron-organics complexes, and (c) calcium carbonate precipitation. Other fouling mechanisms, such as sedimentation of preformed particles and sorption of calcium onto preformed colloids of Fe(OH)3, occurred outside the zone of UV radiation. Hence, these could be confused with concurrent UV-induced mechanisms in full-scale reactors. Iron and/or calcium undoubtedly created the most favorable conditions for fouling to occur; in the absence of both, fouling would be unlikely. The rates of fouling were enhanced when organics were also present; however, when phosphorus was present, fouling in the UV section was reduced. Indeed, UV may be viewed as inhibiting the fouling caused by phosphate complexes.