A quarter-wavelength coaxial cavity with a longitudinal radio-frequency power supply was fabricated and tested. The cavity was designed as a pre-buncher for a thermionic triode-type radio-frequency gun of a mid-infrared free electron laser facility. The triode structure was formed to ensure the reduction of the back-bombarding effect, which usually appears in thermionic radio-frequency guns. The coaxial cavity was tested using a tungsten dispenser cathode. From the results of the cold test, a cavity voltage of about 25 kV can be attained, which corresponds to designed characteristics. In contrast, the hot test showed a sudden drop in voltage, resulting in an unstable operation. The small dimensions of the cavity caused some low-field effects, which led to multipactoring. In this paper, we report the tested characteristics of the pre-bunching cavity.

The common radioactivity substances (Ra-226, Th-232 and K-40) were measured in oil ash samples collected from the Assiut Thermal Power Plant (ATPP) in Egypt by gamma spectrometry. Outcomes were contrasted with those from past investigations. The activity concentrations have declined from past investigations by around 58 %, 77 % and 95 % for 226Ra, 232Th, and 40K, respectively. The reason for this extreme decrease will be discussed. A positive with moderate correlation between 226Ra and 232Th, and between 226Ra and 40K in the examined ash samples was identified from the observed correlation R2 of 0.6 and 0.4 respectively. All estimations of radiological risk indices demonstrate a generous decrease; however, they remain more than the world reference. For instance, the radium equivalent activities (Raeq) and the hazard indices are considerably more than 370 Bq kg-1 and unity, respectively. Mean absorbed dose rate was 3250 nGy h-1, which is around fifty-five times more than the world reference estimation of 59 nGy h-1; relating annual external effective dose is assessed to be at 3.9 mSv y-1, which is around fifty-five times higher than what is found in regions of common foundation radiation 0.07 mSv y-1.

The common radioactivity substances (Ra-226, Th-232 and K-40) were measured in oil ash samples collected from the Assiut Thermal Power Plant (ATPP) in Egypt by gamma spectrometry. Outcomes were contrasted with those from past investigations. The activity concentrations have declined from past investigations by around 58 %, 77 % and 95 % for 226Ra, 232Th, and 40K, respectively. The reason for this extreme decrease will be discussed. A positive with moderate correlation between 226Ra and 232Th, and between 226Ra and 40K in the examined ash samples was identified from the observed correlation R2 of 0.6 and 0.4 respectively. All estimations of radiological risk indices demonstrate a generous decrease; however, they remain more than the world reference. For instance, the radium equivalent activities (Raeq) and the hazard indices are considerably more than 370 Bq kg-1 and unity, respectively. Mean absorbed dose rate was 3250 nGy h-1, which is around fifty-five times more than the world reference estimation of 59 nGy h-1; relating annual external effective dose is assessed to be at 3.9 mSv y-1, which is around fifty-five times higher than what is found in regions of common foundation radiation 0.07 mSv y-1.

In this study, the natural radionuclides in soil and sand have been measured by using high purity germanium (HPGe) detector. While, radon exhalation rate has been measured by Alpha GUARD. The data analysis is performed to determine 226Ra, 232Th, and 40K activity concentrations in addition to 222Rn exhalation rate. The values of radium equivalent activity (Raeq), external hazard index (Hex), internal hazard index (Hin), and absorbed dose rate were ranged from 46.46 to 124.16 Bq⋅kg−1, 0.07 to 0.33 Bq⋅kg−1, 0.09 to 0.42 Bq⋅kg−1, and 13.24 to 58.37 nGy⋅h−1 respectively in all samples. The area and mass exhalation rates were increased from 9.16 ± 2.83 to 16.18 ± 2.83 Bq⋅m−2⋅h−1 and 1.8 ± 1.34 to 11.35 ± 0.98 Bq⋅kg−1⋅h−1 respectively.

Determination of the full-energy peak efficiency of a detection system is significant in the activity calculation of the measured radioactive samples. In this work, we present an experimental method to determine the absolute efficiency calibration of a NaI(Tl) detector, considering that a standard source of interest is unavailable and by using the known specific activity of a standard sample measured using a HPGe detector. The efficiency of a gamma-ray spectrometer that consists of a coaxial HPGe detector is calculated using Canberra ISOCS/LabSOCS software and a fabricated calibration source. To validate our method, environmental samples (rock and soil samples) were analyzed on both the detectors. The obtained activity concentrations were checked by means of the IAEA proficiency test procedure. The performance criteria evaluation results were found to be ‘Acceptable’ for all the analytical determinations of all the radionuclides under study, except for the samples with low activity (15 Bq kg−1 and 10 Bq kg−1 for 226Ra and 232Th, respectively). The precision of the low-activity samples was not considered ‘Acceptable’ as the results were slightly inaccurate; in this case, the results were considered as ‘Warning’ because the relative bias (RB) was less than the maximum acceptable bias (MAB).

Determination of the full-energy peak efficiency of a detection system is significant in the activity calculation of the measured radioactive samples. In this work, we present an experimental method to determine the absolute efficiency calibration of a NaI(Tl) detector, considering that a standard source of interest is unavailable and by using the known specific activity of a standard sample measured using a HPGe detector. The efficiency of a gamma-ray spectrometer that consists of a coaxial HPGe detector is calculated using Canberra ISOCS/LabSOCS software and a fabricated calibration source. To validate our method, environmental samples (rock and soil samples) were analyzed on both the detectors. The obtained activity concentrations were checked by means of the IAEA proficiency test procedure. The performance criteria evaluation results were found to be ‘Acceptable’ for all the analytical determinations of all the radionuclides under study, except for the samples with low activity (15 Bq kg−1 and 10 Bq kg−1 for 226Ra and 232Th, respectively). The precision of the low-activity samples was not considered ‘Acceptable’ as the results were slightly inaccurate; in this case, the results were considered as ‘Warning’ because the relative bias (RB) was less than the maximum acceptable bias (MAB).

Radioactive pollution comes on the top of pollution types that affect human life directly through damaging the human genome or indirectly via his food web. The current study focused on the evaluation of radiation effects of Assiut Thermal Power Plant (ATPP) ashes on two crop plants, potato and squash, in terms of morphological and molecular levels. More particularly, the specific activity concentrations were measured in Bq/kg, of the 238U (226Ra) and 232Th series, and 40K-isotope for the untreated soil sample (control) and ATPP ash sample (represents the radioactive source with 100% concentration). Different concentrations of ATPP ash (0, 2, 4, 6 and 8%) were mixed with soil sample to study the effect of radioactively contaminated soil on potato and squash plants. The results of the present investigation revealed that the morphological characteristics of both potato and squash plants were changed, which reflected a steep regression in the values of all vegetative growth and yield traits. The alterations of the characteristic values were directly proportional to the radioactive ash concentration in the soil. In the same context, the molecular evaluation using PCR-based markers, e.g., ISSR and SCoT helps in understanding and explaining experimental observations at morphological level. ISSR/SCoT bands confirmed the toxicity and mutagenicity of radioactive ash samples at their present dose on both potato and squash plants. The present findings clearly explained the morphometric and genetic abnormalities in two of the main consumed crops by a human. Thus, the green area around the ATPP may disappear in the future due to increasing the pollution in terms of the radioactive component that directly attached to plants or indirectly by mixing with soil.

Radioactive pollution comes on the top of pollution types that affect human life directly through damaging the human genome or indirectly via his food web. The current study focused on the evaluation of radiation effects of Assiut Thermal Power Plant (ATPP) ashes on two crop plants, potato and squash, in terms of morphological and molecular levels. More particularly, the specific activity concentrations were measured in Bq/kg, of the 238U (226Ra) and 232Th series, and 40K-isotope for the untreated soil sample (control) and ATPP ash sample (represents the radioactive source with 100% concentration). Different concentrations of ATPP ash (0, 2, 4, 6 and 8%) were mixed with soil sample to study the effect of radioactively contaminated soil on potato and squash plants. The results of the present investigation revealed that the morphological characteristics of both potato and squash plants were changed, which reflected a steep regression in the values of all vegetative growth and yield traits. The alterations of the characteristic values were directly proportional to the radioactive ash concentration in the soil. In the same context, the molecular evaluation using PCR-based markers, e.g., ISSR and SCoT helps in understanding and explaining experimental observations at morphological level. ISSR/SCoT bands confirmed the toxicity and mutagenicity of radioactive ash samples at their present dose on both potato and squash plants. The present findings clearly explained the morphometric and genetic abnormalities in two of the main consumed crops by a human. Thus, the green area around the ATPP may disappear in the future due to increasing the pollution in terms of the radioactive component that directly attached to plants or indirectly by mixing with soil.

Despite the human brain being made of nearly 60% fat, the vast majority of studies on the mechanisms of neuronal communication which underpin cognition, memory and learning, primarily focus on proteins and/or (epi)genetic mechanisms. Phospholipids are the main component of all cellular membranes and function as substrates for numerous phospholipid-modifying enzymes, including phospholipases, which release free fatty acids (FFAs) and other lipid metabolites that can alter the intrinsic properties of the membranes, recruit and activate critical proteins, and act as lipid signalling molecules. Here, we will review brain specific phospholipases, their roles in membrane remodelling, neuronal function, learning and memory, as well as their disease implications. In particular, we will highlight key roles of unsaturated FFAs, particularly arachidonic acid, in neurotransmitter release, neuroinflammation and memory. In light of recent findings, we will also discuss the emerging role of phospholipase A1 and the creation of saturated FFAs in the brain.