Levels Of Radiation Intensity Research Articles

Preliminary results of the autonomous radiation mapping in Malaysian Nuclear Agency

Autonomous radiation mapping refers to the use of autonomous robots to perform radiation mapping to measure and analyse the levels of radiation intensity of a target area. The primary purpose of the radiation mapping is to uncover the dose distribution across the target area and identify the presence of any hotspots. In this paper, the findings of the autonomous radiation mapping experiments at selected sites in Malaysian Nuclear Agency were presented. The experiments were conducted with a radiation mapping robot namely Autonomous Mobile Robot for Accurate Radiation Detection and Mapping (AMoRA) developed in the previous research. The results consisting of radiation maps of the target areas were presented and discussed.

Quantitative assessment method of muzzle flash and smoke at high noise level on field environment

It is quite a challenge to obtain the temperature and species concentration fields of muzzle flash at high noise level. In this numerical study, radiation intensity of muzzle flash received by the high-speed Complementary Metal-Oxide-Semiconductor (CMOS) camera was simulated based on the line-of-sight method in the direct radiative transfer problem. The inverse radiative transfer problem of reconstructing distributions of temperature and soot volume fraction from the knowledge of flame radiation intensity was transformed into a minimization optimization problem and a meta-heuristic algorithm was used to solve the problem. The effects of the number of detection lines, optical thickness and measurement errors on the reconstruction results were discussed in details. A method to estimate the noise level of radiation intensity was developed, experimental results showed that the signal-to-noise ratio (SNR) of radiation intensity can be successfully inferred when the SNR is greater than 20 dB. Subsequently, prior knowledge of the noise level was introduced in the regularization to achieve a meaningful approximation of the exact value. The reconstruction of the soot volume fraction filed with SNR greater than 40 dB is considered successful with the inclusion of an appropriate regularization term in the objective function, and the reconstruction of the temperature field is feasible even with SNR as low as 15 dB. The high tolerance to the noise level of the radiation intensity gives the reconstruction algorithm the potential to be used in practical experiments of muzzle flash.

The oil pollution and nitric oxide photocatalytic degradation evaluation of composite nanomaterials for asphalt pavement

The frequent occurrence of road pollution by vehicle exhaust and oil pollution has a serious impact on the road environment, the self-clean pavement with nanomaterial coating on the surface with photocatalytic degradation effect could reduce the pollution greatly. In this research, three types of composite photocatalytic coating nanomaterials (Fe2O3-TiO2, Fe2O3-ZnO and TiO2-CeO2) were prepared to evaluate the degradation efficiency of Nitric Oxide (NO) and oil pollution generated during vehicle driving and accidents. The indoor simulation method and testing equipment for oil pollution and NO degradation was proposed, and the photocatalytic degradation rate of the composite nanomaterials was also evaluated. Firstly, the impact of different test conditions of coating amounts, ultraviolet (UV) radiation intensity and reaction time on oil pollution and NO degradation was evaluated in lab. A composite nanomaterial with better degradation efficiency was selected and coated on the surface of the rutting plate specimens to simulate the field environment. The results indicated that the optimum coating amount of composite nanomaterials was affected by UV radiation intensity and reaction time. The degradation rate firstly increased with the increasement of the composite nanomaterial coating amounts, and then reached to a stable state. Considering the combined oil pollution and NO degradation efficiency, the optimal amount of three types of composite nanomaterials used was proposed to be around 26.5 g/m2 when the UV radiation intensity was 20 W/m2 (corresponding to the UV radiation intensity level IV). Among the three types of composite nanomaterials, the Fe2O3-TiO2 shown the best degradation efficiency, and which was also verified by the field simulation experiment. It was recommended that the mass proportion of nano-Fe2O3 and TiO2 was 2:3.

A Cooperation Project in Lesotho: Renewable Energy Potential Maps Embedded in a WebGIS Tool

In this paper the background, activities undertaken, and main outcomes of the cooperation project “Renewable Energy Potential Maps for Lesotho” are presented. The project was launched in 2018 in fulfilment of the Paris Agreement by the Italian Ministry for the Environment and the Lesotho Ministry of Energy and Meteorology, with the aim to facilitate the local Government in the future planning and development of renewable energy in the country. A user-oriented WebGIS platform was utilised to share and analyse the outcomes of the project: a hydrological map to recognize potential areas for power generation; a wind atlas to identify specific sites with the most potential for wind energy generation; a solar radiation map, defining the different levels of radiation intensity, useful to localise sites for photovoltaic production. Human capacity building and technology transfer were carried out to strengthen the local expertise and ability to manage and plan renewable energy sources exploitation. The implementation of the project was based on a fruitful collaboration between scientists and stakeholders at the same time giving the local authorities a useful dataset and tool for renewable energy growth in Lesotho.

A Hybrid Nanofluid of Alumina and Tungsten Oxide for Performance Enhancement of a Parabolic Trough Collector under the Weather Conditions of Budapest

Recently, there has been significant interest in the thermal performance of parabolic trough collectors. They are capable of operating and generating highly variable temperature ranges, which can be used in various applications. This paper, therefore, addressed the thermal performance model of using a parabolic trough collector under the radiation intensity level found in Budapest city, as well as the effect of inserting a hybrid nanofluid as the thermal fluid. First, a new modified hybrid nanofluid of alumina and tungsten oxide-based Therminol VP1 is used to enhance the thermal properties of the thermal fluid to be more efficient to use. This enhancement is performed under various volume concentrations and has a volume fraction of 50:50. Second, in order to demonstrate the effectiveness of the thermal element, mathematical energy balance equations were solved and simulated using MATLAB Symbolic Tools. The simulation is presented for two cases: one under a constant radiation intensity and the other under the radiation intensity level of Budapest. For both cases, the results of the dimensionless Nusselt number, heat transfer coefficient, pressure drop, exergy efficiency, and energy efficiency are described. The major findings show that a volume concentration of 4% (Al2O3 and WO3) based Therminol VP1 was the most efficient volume concentrations in both cases. For the first case, the maximum enhancement of the Nusselt number and the heat transfer coefficient are 138% and 169%, respectively. These results enhanced the thermal and exergy efficiencies by 0.39% and 0.385% at a temperature 600 K, flow rate of 150 L/min, and radiation intensity of 1000 W/m2. For the second case, the maximum exergy and energy values are recorded at midday under Budapest’s summer climatic conditions and reach 32.728% and 71.255%, respectively, under the optimum temperature of 500 K and flow rate of 150 L/min. Accordingly, the mean improvement in thermal and exergy efficiencies approximately equal to 0.25% at a high concentration, regardless of the season (summer or winter).

Experimental evaluation of the thermal and hygrometric behavior of a Colombian greenhouse used for the production of roses (Rosa spp.)

Abstract The spatial behavior of the environmental variables involved in rose production is one of the factors of greatest current interest in the Colombian ornamental sector. The aim of this work consisted in the evaluation of a passive greenhouse through an experimental approach that included the capture and recording of data through a grid of 40 sensors homogeneously distributed inside the greenhouse. The data processing was carried out through the application of geostatistical techniques that allowed to obtain contour plots for 5 levels of radiation intensity. The results of the exploratory analysis showed that the behavior of temperature, relative humidity and vapour pressure deficit are not the most suitable for rose production, mainly for the conditions of the night period where the temperature exhibited values below 12.5 °C, the relative humidity was above 90% and the vapour pressure deficit was below 0.1 kPa. On the other hand in the structural analysis the circular model of theoretical semivariogram was the one that better degree of adjustment presented in comparison with the experimental data finding that a strong spatial dependency exists for the studied variables, the prediction of the not sampled points was made by means of the method of ordinary kriging finding that horizontal gradients of temperature and relative humidity exist inside the greenhouse that increases in magnitude according to the level of radiation arriving to reach values of 6.1 °C and 30.4%.

Mobile robot for radiation mapping in indoor environment

Radiation mapping is the process of measuring radiation intensity level at distributed sampling points in a predefined region of interest (ROI). This procedure is crucial in any radiological related emergency to locate contamination hotspot(s) or in routine inspections in any radiation facilities. When workers knowingly enter a high radiation zone to perform radiation mapping, they are exposed to the risk of radiation exposure. Mobile robot is a potential solution that could eliminate the health and safety risk and subsequently improve the measurement accuracy. This paper reports implementation of mobile robot for radiation mapping by using a commercial mobile robot platform, Turtlebot2 in conjunction with Robot Operating System (ROS). Mobile robot is capable to generate physical map of the targeted environment by using Simultaneous Localization and Mapping (SLAM). Simultaneously, Geiger Muller detector is utilized to perform radiation measurement. The radiation data is directly plotted on the physical map hence the radiation intensity distribution throughout the ROI could be assessed. Functionality of the radiation mapping robot is evaluated in real-world experiments and the results will be presented in the paper.

Study of the effect of ultrasound scanner settings on the level of radiation intensity by the reciprocity method

In this paper, a new method of measuring the intensity on the radiating surface of the convex sensor of the ultrasonic diagnostic scanner EDAN U50 with its various settings was proposed, based on the reciprocity method using a hydrophone calibrated with a vibration simulator. The effect of the following scanner settings on the peak-spatial average time-averaged intensity in B-mode was experimentally investigated: ultrasonic radiation frequencies, number of focuses, and number of focus positions. It was found that changing the scanner settings significantly changes the temporal parameters of the emitted bursts of pulses, which affects the result of averaging intensity over time. At the same time, an increase in the number of focuses leads to a decrease in intensity, while an increase in the focus of the positions and frequency of the radiation, on the contrary, leads to its growth. Studies have shown that the intensity value exceeds the allowable values at almost any settings of the ultrasound scanner, with the exception of the ultrasound frequency of 2.5 MHz.

Monitoring Electromagnetic Radiation Emissions in Buildings and Developing Strategies for Improved Indoor Environmental Quality.

Electronic devices have become ubiquitous in daily life, but they emit electromagnetic radiation, which may have negative health impacts at excessive levels. Little is known regarding the impact of radiation emissions on building occupants or strategies for reducing its intensity. This study applied a novel approach using system analysis to quantify radiation exposure in building spaces, examine building material responses to radiation propagation, and investigate risks to human health in the country of Qatar. Radiation intensity levels varied based on the location and type of building space. Different types of construction materials showed varied responses to electromagnetic field wave propagation. Drywall exhibited the best blocking effect, whereas glass and lumber walls exhibited poor blocking effects. The field strengths quantified in this study are less than the corresponding reference values specified by some jurisdictions, but they are still significantly higher than the safety levels defined in many other countries, which could result in significant health risks. The key strategies for improving indoor environmental quality include the use of shielding materials, spatial design, reduction of exposure time, increased exposure distance, and complete avoidance of exposure in sensitive areas.

Influence of Environmentally Relevant Physicochemical Conditions on a Highly Efficient Inorganic Ice Nucleating Particle

Ice nucleation microphysical processes are identified to be of high importance in forecasting the magnitude of the Earth’s climate change. The environmental conditions often influence the ice nucleation processes in the Earth’s atmosphere. We herein study the impact of various environmental conditions on FeHg (maghemite–Hg2Cl2 composite), a highly efficient ice nucleating particle with similar freezing point to the best inorganic ice nuclei, AgI. FeHg is formed from FeCl2·4H2O and HgCl2, which are observed in the environment, in contrast to AgI, which is rarely found. The ice nucleation efficacy remained unchanged for FeHg under ambient conditions for a long duration. To mimic the atmosphere, we performed a series of experiments using a suite of complementary techniques, at various levels of radiation intensity, temperature, and pH for FeHg. Experiments were also performed in the presence of atmospheric pollutants, such as ozone (in the presence or absence of light), as well as nine emerging metal oxides ...

Enhancement of natural ventilation of a circular greenhouse with double wall solar chimney

The study has been devoted to develop an energy efficient agricultural greenhouse system. To serve this purpose a circular greenhouse with double walled vertical hollow cylindrical type solar chimney has been selected. The circular shape is beneficial to allow the outside wind from any direction. The solar chimney is constructed with double wall- the outer wall is made of fibre reinforced plastic (FRP) sheet to transmit solar radiation and the inner wall is made of blackened aluminium sheet to absorb solar radiation. Thus ventilation is occurred by solar as well as wind effect. It is found that 0.6-0.8 air change per minute (ACM) ventilation rate could be obtained, when total radiation intensity level remains 100-600 W/m2 as well as the ambient temperature remains 30°C. It is found that solar chimney a circular greenhouse can improve ventilation rate 1.6-1.7 times.

Restoration of orbicularis oculi muscle function in rabbits with peripheral facial paralysis via an implantable artificial facial nerve system.

The purpose of the present study was to restore orbicularis oculi muscle function using the implantable artificial facial nerve system (IAFNS). The in vivo part of the IAFNS was implanted into 12 rabbits that were facially paralyzed on the right side of the face to restore the function of the orbicularis oculi muscle, which was indicated by closure of the paralyzed eye when the contralateral side was closed. Wireless communication links were established between the in vivo part (the processing chip and microelectrode) and the external part (System Controller program) of the system, which were used to set the working parameters and indicate the working state of the processing chip and microelectrode implanted in the body. A disturbance field strength test of the IAFNS processing chip was performed in a magnetic field dark room to test its electromagnetic radiation safety. Test distances investigated were 0, 1, 3 and 10 m, and levels of radiation intensity were evaluated in the horizontal and vertical planes. Anti-interference experiments were performed to test the stability of the processing chip under the interference of electromagnetic radiation. The fully implanted IAFNS was run for 5 h per day for 30 consecutive days to evaluate the accuracy and precision as well as the long-term stability and effectiveness of wireless communication. The stimulus intensity (range, 0–8 mA) was set every 3 days to confirm the minimum stimulation intensity which could indicate the movement of the paralyzed side was set. Effective stimulation rate was also tested by comparing the number of eye-close movements on both sides. The results of the present study indicated that the IAFNS could rebuild the reflex arc, inducing the experimental rabbits to close the eye of the paralyzed side. The System Controller program was able to reflect the in vivo part of the artificial facial nerve system in real-time and adjust the working pattern, stimulation intensity and frequency, range of wave and stimulation time. No significant differences in the stimulus intensities were observed during 30 days. The artificial facial nerve system chip operation stable in the anti-interference test, and the radiation field strength of the system was in a safe range according to the national standard. The IAFNS functioned without any interference and was able to restore functionality to facially paralyzed rabbits over the course of 30 days.

Comparison of Drying Characteristics and Quality of Peppermint Leaves Using Different Drying Methods

In this study, we investigated the effects of hot air, infrared and combined hot air-infrared drying methods on the drying time, energy consumption, color, rehydration and oil content of peppermint leaves. Three different air temperatures (30, 40 and 50C) and air velocities (0.5, 1 and 1.5 m/s) were used in the hot air drying. Infrared drying process was implemented using three levels of radiation intensity (1500, 3000 and 4500 W/m2), three distances between emitter and sample (10, 15 and 20 cm) and three air velocities (0.5, 1 and 1.5 m/s). The results showed that the optimum drying period and energy consumption were obtained when infrared- and hot air-drying were applied simultaneously. The results also showed that combined drying resulted in dried leaves of superior quality when compared to the leaves dried separately by either hot air alone or infrared, exhibiting lower total color change, greater rehydration ratio and higher extraction oil yield. Practical Applications Peppermint leaves are highly valuable products with wide range of industrial uses but extremely perishable in normal surrounding temperature-humidity conditions too. This fact makes their preservation important. Drying is a common preservation method that is applied to foods and agricultural products. Hot air has been traditionally used for drying peppermint leaves; however, infrared radiation has been employed for this purpose recently. However, there is very little knowledge, if none, on the use of combination of hot air and infrared drying method on the drying performance as well as the quality of final dried leaves. We treated fresh peppermint leaves by hot air drying, infrared drying and combined hot air-infrared drying, and compared the quality of final products and energy consumption during drying, aiming to find out the optimum drying method and drying parameters; while are beneficial to related industry in drying this valuable product. Our research work confirmed that combined hot air-infrared drying is a good alternative instead of the use of hot air drying or infrared drying separately.

Characterization of hot-air drying and infrared drying of spearmint (Mentha spicata L.) leaves

In this study, spearmint leaves were dried using hot-air (HA) and infrared (IR) techniques. Dried products were comprehensively analyzed for their drying time, specific energy consumption (SEC), rehydration, essential oil content and color changes. The IR drying process was carried out at radiation intensity levels of 1562, 3125 and 4688 W/m2, emitter to sample distances of 10, 15 and 20 cm and air temperatures of 30, 40 and 50 °C. For HA drying, three levels of air temperature (30, 40 and 50 °C) and air velocity (0.5, 1 and 1.5 m/s) were applied. The results indicated that drying time, SEC and color changes were lower in IR drying of spearmint than in HA drying. IR drying gave the highest essential oil content (0.95 %) and rehydration ratio (0.788 kg water/kg dry matter (DM)). Totally, it was observed that IR drying of spearmint resulted in better quality preservation and had lower energy costs in comparison to HA drying.

An integrated energy and quality approach to optimization of green peas drying in a hot air infrared-assisted vibratory bed dryer

In this study, the drying behavior of a small spherical product, green peas, from moisture content of 75.34±0.53 (%w.b.) to 20.02±0.14 (%w.b.), was investigated in a hot air infrared-assisted vibratory bed dryer. The quality of dried product, including roundness, shrinkage and color, was assessed using machine vision techniques. The experiments were conducted using drying air temperatures of 30, 40, and 50°C, infrared radiation intensity levels of 2000, 4000, and 9000Wm−2 as well as no radiation (control), green pea depths of 1, 2, and 3 layers, and two modes: vibratory and fixed bed. The specific energy consumption (SEC) of drying was also measured. The results showed that drying time and SEC decreased significantly in the vibratory bed (p<0.01). In addition, the original quality of dried green peas was better maintained in the infrared-assisted vibratory bed dryer. Finally, drying time, shrinkage, roundness, color and moisture content of green peas were simulated for vibratory bed mode using Artificial Neural Network.

Heat and Mass Transfer and Energy Aspects in Combined Infrared-Convective Drying of Bee-Pollen

A hybrid drying process based on the application of infrared (IR) radiation combined to non-heated air flow was proposed for bee-pollen drying. The IR source was located at a distance of 32 cm from the samples. Experiments in the hybrid dryer were conducted with pollen grains arranged in a single layer and exposed to three radiation intensity levels (150, 300 and 450 W/m2) and three air velocity levels (1.0, 2.0 and 3.0 m/s) at 25°C. The surface temperature of the material was measured during drying through an optical pyrometer. The effects of the process parameters on the drying kinetics and specific energy consumption were evaluated. Experimental results showed that for any particular air velocity increasing IR heat flux led to an intensification of mass transfer rate, decreasing drying time and thus reducing energy consumption. Minimum energy consumption in hybrid frying of pollen was associated with the application of the highest radiation intensity and lowest air velocity. It was also found that cooling effect increased with air velocity, which resulted in a decreased driving force for mass transfer and increased drying time and energy consumption.

Computational derivation of irradiance on building surfaces: An empirically-based model comparison

Performance simulation applications require reliable information regarding the intensity of solar irradiance on arbitrarily oriented building surfaces in order to properly predict buildings' energy use or to configure building-integrated solar energy systems. Since measured irradiance databases typically include only horizontal irradiance values, solar radiation intensity on inclined surfaces must be computationally derived. In this context, the present paper compares six options to derive, from horizontal irradiance data, solar radiation intensity levels on inclined surfaces. To evaluate these options, simulated downward vertical irradiance on four orientations were compared with measurements obtained in Austria. Two options that use both global and diffuse horizontal irradiance values for sky radiance generation delivered slightly better results than the others, which require only global horizontal irradiance. However, the range of errors was rather high for all options. Even for the best-ranked option, no more than 64% of the results had a relative error of less than ±20%.

INFRARED DRYING OF LEMON SLICES

A study was carried out to test and evaluate the use of infra-red radiation as heat energy source for drying lemon slices. A laboratory scale dryer was developed and tested at the laboratory of Agric. Eng. Dept. Fac. of Agric. Mansoura Univ. The experimental treatments included three different levels of radiation intensity (0.973, 1.093, and1.161 kW/m2), three different air temperatures (40, 50 and 60°C) and constant air velocity of 1 m/sec. The drying behavior was simulated using two different thin layer models (Lewis's and Henderson, and Pabis's). The studied models were compared with the obtained drying data, and the most suitable model for predicting the change in lemon moisture content during drying process was then assessed. Final quality of the dried lemons was also determined. The results show that, both studied models could describe the drying behavior of lemons satisfactorily. However, Lewis's model considered more proper for describing the drying behavior and predicting the changes in moisture content in terms of precision and application simplicity. The quality tests of the dried lemons showed that, radiation intensity of 0.973 kW/m2 with air temperature of 50°C recorded the best dried lemon quality in terms of higher retention of ascorbic acid (Vitamin C), citric acid and total soluble sugars.

Effect of Short-Term GSM Radiation at Representative Levels in Society on a Biological Model: The Ant Myrmica sabuleti

Well-controlled electromagnetic exposure conditions were set up at a representative societal GSM radiation intensity level, 1.5 V/m, which is the legally allowed level in Brussels. Two nests of the ant species Myrmica sabuleti were repeatedly irradiated during 10 min. before their behavior was observed, based on the analysis of the ant trajectories. Under these exposure conditions, behavioral effects were detected. The ants’ locomotion slightly changed. The ants’ orientation towards their attractive alarm pheromone statistically became of lower quality. The ants still presented their trail following behavior but less efficiently. In this controversial issue, ants could be considered as possible bioindicators.

ESTIMATING CELLPHONE SIGNAL INTENSITY &amp; IDENTIFYING RADIATION HOTSPOT AREA FOR TIRUNELVELI TALUK USING RS AND GIS

The increased uses of mobile phones have raised pub lic interest in possible health issues associated w ith exposure to electromagnetic energy. For the speedy transmission and avoiding th e construction of more towers, the single tower can be shared by multiple network operators. The simultaneous exposure to multiple fr equency fields, the sum of all the radiation must b e taken into consideration so the radiation intensity level exceeds by several times than the prescribed guideline. Hence, the public is being exposed to continuous, low intensity radiations from these towers. Present Sur vey has been designed to identify signal strength a mong the people dwelling near the base station. Signal Strength predicted by inte gration of NDVI methodology is taken into account f or factors like trees, trunks, leaves, branches, their density and their heights r elative to the antenna heights and also it has been calculated by both theoretical and practical. In this regard the present study, practi cal field investigations of existing towers have be en done by using SCEPTOR (Mobile GIS/GPS receiver). These GPS data fed to GIS for cr eating a new layer along with DEM file and satellit e image for creating virtual model.3D city model has been performed for the stud y area. Finally the radiation hotspot area has been identified by using viewshed analysis.