Investigation of cosmic-ray induced background of Germanium gamma spectrometer using GEANT4 simulation.

In this article, a GEANT4 Monte Carlo simulation toolkit was used to study the response of the cosmic-ray induced background on a High-Purity Germanium (HPGe) gamma spectrometer in the wide energy range, up to 100MeV. The natural radiation background measurements of the spectrometer were carried out in the energy region from 0.04 to 50MeV.

Gross alpha and beta activity and annual committed effective dose due to natural radionuclides in some water spinach (ipomoea aquatica Forssk) samples in Ho Chi Minh City, Vietnam.

The results of gross alpha and beta radioactivity measurement in water spinach samples from some districts in Ho Chi Minh City, Vietnam are presented in this paper. The measurements were performed using a low-background proportional counters LB4200 manufactured by Canberra Company, Inc. Mean concentrations of gross alpha and beta activity were found to be 1.

Estimating the Internal Dose for 131I Production Workers From Air Sampling Method.

Besides the most common methods of internal dose assessment from inhaled 131I, that are thyroid monitoring and urine analysis, air sampling is a possible way but rarely used for dose estimate. This study aimed to focus on the utilisation of portable air sampler to estimate the internal dose for workers working at 131I production facility. In addition, internal dose estimated from urine analysis at the same time was carried out for comparison.

Estimating thickness of the inner dead-layer of n-type HPGe detector.

In this study, a procedure to estimate thickness of the inner dead-layer of an n-type coaxial HPGe detector is described. Experimental measurements are carried out with standard point sources: (54)Mn, (57)Co, (60)Co, (88)Y, (109)Cd, (134)Cs, (137)Cs, and (152)Eu at distances of 5 and 10cm from source to detector. Shape and dimensions of a high-purity germanium (HPGe) detector are determined by radiography to characterize the geometry accurately for Monte Carlo simulation.

Intercomparison NaI(Tl) and HPGe spectrometry to studies of natural radioactivity on geological samples.

In this study, in situ gamma spectra using NaI(Tl) detector have been compared with the laboratory measurements by using HPGe detector on geological samples. The results for measuring naturally occurring terrestrial gamma radiation of K and the decay series of Th and, U respectively of both detectors show a maximum deviation about 5%. The mass activities series from both detectors were checked for coherence using proficiency test procedure from the International Atomic Energy Agency.

Using smartphone as a motion detector to collect time-microenvironment data for estimating the inhalation dose.

During the production of iodine-131 from neutron irradiated tellurium dioxide by the dry distillation, a considerable amount of (131)I vapor is dispersed to the indoor air. People who routinely work at the production area may result in a significant risk of exposure to chronic intake by inhaled (131)I. This study aims to estimate the inhalation dose for individuals manipulating the (131)I at a radioisotope production.

Estimation and Preparation of the Hypervariable Regions I/II Templates for Mitochondrial DNA Typing From Human Bones and Teeth Remains Using Singleplex Quantitative Polymerase Chain Reaction.

A method was designed for estimating and sequencing of mitochondrial DNA (mtDNA) that effectively and more quickly provides a complete mtDNA profile. In this context, we have developed this novel strategy for typing mtDNA from 10 bones and teeth remains (3 months to 44 years). The quantification of mtDNA was achieved by singleplex real-time polymerase chain reaction of the hypervariable region I fragment (445 bp) and hypervariable region II fragment (617 bp).

A prototype of radioactive waste drum monitor by non-destructive assays using gamma spectrometry.

In this work, segmented gamma scanning and the gamma emission tomography were used to locate unknown sources in a radioactive waste drum. The simulated detector response function and full energy peak efficiency are compared to corresponding experimental data and show about 5.3% difference for an energy ranging from 81keV to 1332.

A Novel Method to Predict Highly Expressed Genes Based on Radius Clustering and Relative Synonymous Codon Usage.

Recombinant proteins play an important role in many aspects of life and have generated a huge income, notably in the industrial enzyme business. A gene is introduced into a vector and expressed in a host organism-for example, E. coli-to obtain a high productivity of target protein.

Verification of Compton scattering spectrum of a 662keV photon beam scattered on a cylindrical steel target using MCNP5 code.

This article focuses on the possible application of a (137)Cs low-radioactive source (5mCi) and a NaI(Tl) detector for measuring the saturation thickness of solid cylindrical steel targets. In order to increase the reliability of the obtained experimental results and to verify the detector response function of Compton scattering spectrum, simulation using Monte Carlo N-particle (MCNP5) code is performed. The obtained results are in good agreement with the response functions of the simulation scattering and experimental scattering spectra.

Revision of the fern genus Orthiopteris (Saccolomataceae) in Malesia and adjacent regions.

A taxonomic revision of the Old-World representatives of the fern genus Orthiopteris is presented. We recognize eight species, one of which is newly described (Orthiopterissamoensis), and five varieties, of which two are newly described (Orthiopteriscampyluravar.insularis and Orthiopteriscampyluravar.

Evaluation of Titanium Dioxide as a Binding Phase for the Passive Sampling of Glyphosate and Aminomethyl Phosphonic Acid in an Aquatic Environment.

Glyphosate is the most widely used herbicide on a world scale for the last 40 years, for both urban and agricultural uses. Here we describe the first passive sampling method for estimating the concentration of glyphosate and AMPA (aminomethyl phosphonic acid, one of its major degradation products) in surface water. The sampling method is based on a newly developed configuration of the diffusive gradient in thin-film (DGT) technique, which includes a TiO2 binding phase, already in use for a wide range of anions.

Chemical constituents from Sonneratia ovata Backer and their in vitro cytotoxicity and acetylcholinesterase inhibitory activities.

Sonneratia ovata Backer, Sonneratiaceae, is a widespread plant in mangrove forests in Vietnam, Cambodia, Thailand, Indonesia. Sonneratia ovata's chemical composition remains mostly unknown. Therefore, we now report on the structural elucidation of three new phenolics, sonnerphenolic A (1), sonnerphenolic B (2), and sonnerphenolic C (23), a new cerebroside, sonnercerebroside (3) together with nineteen known compounds, including nine lignans (5-13), two steroids (14, 15), two triterpenoids (16, 17), three gallic acid derivatives (18-20), two phenolic derivatives (4, 22) and a 1-O-benzyl-β-d-glucopyranose (21) isolated from the leaves of Sonneratia ovata.