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The purpose of this study was to study the spatial distribution of traces of alpha particles formed by radon and its descendants in the diffusion chambers of radon. Three cylindrical chambers equipped with CR-39 detectors were used, the radon concentration was estimated using the RAD7 device. Registration revealed an uneven distribution of traces of alpha particles on the surface of the detector, the density of traces near the camera walls was 30% lower than in the center. These results were the opposite of analytical predictions based on the same camera dimensions. The critical angle of detection relative to the particle incidence energy was determined using the Track_vision software, which showed a significant effect of camera size and critical angle on the distribution of track density. In addition, the study examined the sources of changes in track density by analyzing partial contributions of volumetric and sedimentary fractions of radon and its descendants. There was an increase in the sidewall share, and with an increase in the radial distance from the detector Center, the volume and platform share decreased. Changing the dimensions of the camera affected the relative effects of these partial contributions, resulting in different distributions of visible traces on the detector's surface. The experimental results were compared with the values obtained using previously developed software based on the Monte Carlo method. Five different expressions of the detector response function were used, two of which greatly underestimated the results of the experiment. This comprehensive study sheds light on the complex dynamics of alpha particle propagation paths in radon diffusion chambers and highlights the importance of accurate modeling for reliable estimation of radon concentrations. [ABSTRACT FROM AUTHOR]

This study shows the natural radioactivity of alpha particles that result from the decay of radium to radon-222. Thus, radon gas was identified in several powder milk varieties in this investigation utilizing a solid-state nuclear track detector (SSNTD) and CR-39 closed container technology analysis. Since milk is consumed by so many people, it is crucial to analyze it. Analysis of radon 222Rn concentrations is very essential to achieve the relative contributions of several chemicals to the total amount of radon in the human body. According to the findings, the average radon in Bq/m3 concentration was found to be 0.0129, which is less than the internationally permissible values, radon exhalation rate mBqm/ h2 with an average 1.536*10-6, also the annual effective dose in mSv/y with an average 5.374*10-5. The average number of colon cancer cases annually per million CPPP is 1.074*10-10. All values were below the ICRP-recorded globally permitted level. Pearson coefficient for the coefficients calculated in this research it was found that the relationship is direct and correlation is significant. Therefore one can conclude that all powder milk samples analyzed in this study are safe to use. [ABSTRACT FROM AUTHOR]

Tropical cyclones (TCs) seriously threaten the safety of human life and property especially when approaching a coast or making landfall. Robust, long-lead predictions are valuable for managing policy responses. However, despite decades of efforts, seasonal prediction of TCs remains a challenge. Here, we introduce a deep-learning prediction model to make skillful seasonal prediction of TC track density in the Western North Pacific (WNP) during the typhoon season, with a lead time of up to four months. To overcome the limited availability of observational data, we use TC tracks from CMIP5 and CMIP6 climate models as the training data, followed by a transfer-learning method to train a fully convolutional neural network named SeaUnet. Through the deep-learning process (i.e., heat map analysis), SeaUnet identifies physically based precursors. We show that SeaUnet has a good performance for typhoon distribution, outperforming state-of-the-art dynamic systems. The success of SeaUnet indicates its potential for operational use. [ABSTRACT FROM AUTHOR]

Compared with total account of basin wide tropical cyclones (TC) genesis, the prevailing tracks of TC activity and its potential of landfall is more important for disaster prevention. Despite its relatively lower predictability, a hybrid statistical–dynamical model was developed based on the relationship between leading empirical orthogonal function (EOF) modes of Western North Pacific (WNP) TC track patterns and large scale environmental fields. Due to the significant difference in both variability and associated mechanisms on different time scale as revealed in previous studies, the temporal variations of three leading principal components (PCs) are separated into decadal and inter-annual component and forecasted respectively. Potential predictors for Multi-Linear Regression (MLR) model was selected through stepwise regression analysis based on the correlation maps between each components of leading PCs and environmental fields in both observations and Beijing Climate Center climate system model version 1.1 (BCC_CSM1.1) hindcast. The forecast map of anomalous WNP TC track density was obtained through weighted composite of forecasted leading PCs and EOF modes according to its explained variance. One-year-out cross validation test shows that the hybrid model well captures the inter-annual variations of WNP TC track patterns. The hybrid model also shows significant improvement of prediction skill compared with ENSO reference forecast, indicates its potential of application in operational prediction. [ABSTRACT FROM AUTHOR]

A better understanding of expected future cyclonic activity, especially in winter in the Mediterranean basin, is essential in developing scientifically based adaptation and mitigation methods to study extreme precipitation and wind anomalies. The aim of this study was to analyze the changes in winter cyclonic activity in the Mediterranean–Black Sea region, as part of the North Atlantic–European sector, at three 15 year periods: the beginning, middle, and end of the 21st century. Our projections were based on an ensemble of seven Coupled Model Intercomparison Project (CMIP), phase 6, models, which showed the best agreement with NCEP/NCAR and ERA5 reanalyses under the intermediate SSP2-4.5 and highest-emission SSP5-8.5 scenarios. The results showed a consistent increase in the frequency of cyclones over Central Europe and the British Isles, which was associated with shifts in cyclone tracks: northward from the western Mediterranean region and southward from the Icelandic Low region. The latter shift led to a decrease in the frequency in the northern Atlantic–European region. At the same time, there was a reduction in the frequency of cyclones over the eastern region of the Mediterranean Sea, consistent with the decrease in cyclogenesis events. Area-averaged cyclone numbers in the western and eastern Mediterranean and Black Sea subregions reduced at the end of the century under the highest-emission scenario, but not constantly. There was a rise in the middle of the 21st century under both scenarios, which may be linked to long-term multidecadal variability or regional features. In general, our study showed that the future winter cyclonic activity in the Mediterranean–Black Sea region will respond unevenly to global climate changes, due to regional and monthly features and long-term quasiperiodic variability. [ABSTRACT FROM AUTHOR]

In this research, The uranium concentration in teeth samples was measured using a CR-39 track detector and the fission tracks registration method., for 25 samples of teeth distributed across Samawa City, each weighing (0.7) grams and (2) mm in thickness. Exposed done after preparing the samples into small spherical pellets covered with a 1x1cm2 CR-39 detector. These samples with detectors together were irradiated using an (241Am-Be) source with a neutron flux (5x103 n.cm-2.s-1) for one week. These samples were compared with standard samples to find uranium concentration. The results show that the maximum value of uranium concentration was (2.273 ppm) and value of the minimum uranium concentration was (0.626 ppm) and the concentration of uranium in females was higher than in males, the concentration of uranium was affected by several factors: the region of study, gender and age of the human.

Copyright of Journal of Kufa - Physics is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Tropical cyclones (TCs) seriously threaten the safety of human life and property especially when approaching a coast or making landfall. Robust, long-lead predictions are valuable for managing policy responses. However, despite decades of efforts, seasonal prediction of TCs remains a challenge. Here, we introduce a deep-learning prediction model to make skillful seasonal prediction of TC track density in the Western North Pacific (WNP) during the typhoon season, with a lead time of up to four months. To overcome the limited availability of observational data, we use TC tracks from CMIP5 and CMIP6 climate models as the training data, followed by a transfer-learning method to train a fully convolutional neural network named SeaUnet. Through the deep-learning process (i.e., heat map analysis), SeaUnet identifies physically based precursors. We show that SeaUnet has a good performance for typhoon distribution, outperforming state-of-the-art dynamic systems. The success of SeaUnet indicates its potential for operational use.

A better understanding of expected future cyclonic activity, especially in winter in the Mediterranean basin, is essential in developing scientifically based adaptation and mitigation methods to study extreme precipitation and wind anomalies. The aim of this study was to analyze the changes in winter cyclonic activity in the Mediterranean–Black Sea region, as part of the North Atlantic–European sector, at three 15 year periods: the beginning, middle, and end of the 21st century. Our projections were based on an ensemble of seven Coupled Model Intercomparison Project (CMIP), phase 6, models, which showed the best agreement with NCEP/NCAR and ERA5 reanalyses under the intermediate SSP2-4.5 and highest-emission SSP5-8.5 scenarios. The results showed a consistent increase in the frequency of cyclones over Central Europe and the British Isles, which was associated with shifts in cyclone tracks: northward from the western Mediterranean region and southward from the Icelandic Low region. The latter shift led to a decrease in the frequency in the northern Atlantic–European region. At the same time, there was a reduction in the frequency of cyclones over the eastern region of the Mediterranean Sea, consistent with the decrease in cyclogenesis events. Area-averaged cyclone numbers in the western and eastern Mediterranean and Black Sea subregions reduced at the end of the century under the highest-emission scenario, but not constantly. There was a rise in the middle of the 21st century under both scenarios, which may be linked to long-term multidecadal variability or regional features. In general, our study showed that the future winter cyclonic activity in the Mediterranean–Black Sea region will respond unevenly to global climate changes, due to regional and monthly features and long-term quasiperiodic variability.

Copyright of Journal of College of Education is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The long-term trend of swell-like waves invading the east coast of Korea was identified by using observations and hindcast data from 1979 to 2016. We defined a swell-like wave as a wave with a height of 2 m and a peak period of 10 s on the basis of a literature review of human casualties and property damage in the region. In total, 179 swell-like wave cases were detected from 1979 to 2016, with 132 cases caused by extratropical cyclones (ETCs). The track density analysis indicated that the ETCs were mainly generated on the east coast of China, over the East/Japan Sea, and over the Kuroshio-Oyashio extension region and then moved northeast. This reflects the prevailing wind direction, which was the most significant factor in generating the swell-like waves. The number of swell-like waves has been significantly increasing since the 2000s. This increasing trend of swell-like waves is linked with the synoptic eddy activity with a correlation of 0.53. They were associated with the reversed meridional gradient of surface air temperature and the consequent negative vertical wind shear anomaly near 40° N.

How future tropical cyclone (TC) activity could change under global warming is enormously important to society, which has been widely assessed using state‐of‐the‐art climate models. However, these models were predominantly based on projection of an El Niño‐like warming pattern. Recent studies suggested that a La Niña‐like warming pattern is also possible. Here we compare the responses of TC track density (TCTD) over the western North Pacific and North Atlantic to the two distinct global warming patterns. We find that the La Niña‐like warming pattern reduces western North Pacific TCTD except in the South China Sea and along China coast and increases NA TCTD, while the El Niño‐like warming pattern generally reduces TCTD in both basins. This is due to different responses of large‐scale dynamic/thermodynamic conditions to the distinct zonal sea surface temperature gradients associated with the two warming patterns. These results help better understand potential future change in TC tracks. Key Points: The La Niña‐like warming reduces (increases) TC track density in the main WNP (NA), while the El Niño‐like warming reduces it in two basinsThe different responses are due to the different tropical zonal SST gradients associated with the two warming patternsChina and North America would experience more landfalling TCs in La Niña‐like warming pattern than in El Niño‐like warming pattern [ABSTRACT FROM AUTHOR]

This paper describes preparation of composite thin films of 12 ± 1 µm from cellulose acetate (CA) and cellulose acetate (CA) -cellulose nitrate (CN) blend on a polyester support for solid state nuclear track detection (SSNTD) application. Films were prepared using a spin coater and their experimentally observed film thickness was compared with theoretically predicted film thickness using Damon and Meyerhofer equations. Effect of RPM of spin coater on cellulose nitrate and cellulose acetate thin films is reported for the first time. Track detection properties of CA + CN are tested and compared with indigenous CN and imported LR-115™ film. [ABSTRACT FROM AUTHOR]

A significant correlation between the track density measured by CR-39 and the affluence has been found in the current study. This correlation can be used to calculate the expected track density in solid state nuclear track detector irradiated by any alpha source of known activity without using the detectors. Nine pieces of CR-39 were irradiated with alpha particles from Am-241 (10 µCi) point source for 0 s, 10 s, 20 s, 30 s, 40 s, 50 s, 60 s, 70 s and 80 s. The absorbance in UV-visible region (before and after etching of the detector) and in the energy band gap showed an acceptable correlation at 650 nm wavelength. This result leads to two semi-empirical equations: first equation between the track density and the absorbance; and second equation between the absorbance and the affluence. These findings can give the track density or the affluence by calculating the absorbance of the detector after etching without microscopic viewing and calibration. [ABSTRACT FROM AUTHOR]

Multiple-input single-output two-dimensional magnetic recording gain in a magnetic tape system was studied under the condition where the bit aspect ratio is 22%–37% compared to current tape systems. The performance was mainly evaluated in terms of signal-to-noise ratio (SNR) cross-track profile utilizing a 2-D read-back signal synthesized from the waveform acquired with a conventional single-reader tape head. The results show that, depending on the reader pitch selected, either significant gain in tracking margin up to 215% compared to the traditional 1-D signal-processing scheme or an additional SNR gain accompanied with a moderate increase in approximately 30% in tracking margin can be achieved by utilizing the 2-D equalization. [ABSTRACT FROM AUTHOR]

In the present study the bulk etch rate, the bulk activation energy, the track density and the degree of crystallinity percentage have been examined for gamma irradiated samples with 60Co source at doses ranging from 0 to 200 kGy. After gamma irradiation the samples were exposed to zirconium sand to collect α-particle tracks. Samples were etched at 60, 65, 70, 75 and 80°C in 6.25 N NaOH solution for 4 h. Results indicated that, the bulk etch rate increases with the increase of gamma absorbed dose at different etching temperatures. The bulk activation energy and the track density decreased with the increase of the gamma absorbed dose. The degree of crystallinity percentage for un-etched and etched samples also has been studied for different gamma doses. The increase in bulk etch rate and the decrease in both of bulk activation energy and track density with increase in the gamma dose may be due to the degradation in CR-39 polymeric material. [ABSTRACT FROM AUTHOR]