Contribution for the derivation of a soil screening value (SSV) for uranium, using a natural reference soil

In order to regulate the management of contaminated land, many countries have been deriving soil screening values (SSV). However, the ecotoxicological data available for uranium is still insufficient and incapable to generate SSVs for European soils. In this sense, and so as to make up for this shortcoming, a battery of ecotoxicological assays focusing on soil functions and organisms, and a wide range of endpoints was carried out, using a natural soil artificially spiked with uranium. In terrestrial ecotoxicology, it is widely recognized that soils have different properties that can influence the bioavailability and the toxicity of chemicals. In this context, SSVs derived for artificial soils or for other types of natural soils, may lead to unfeasible environmental risk assessment. Hence, the use of natural regional representative soils is of great importance in the derivation of SSVs. A Portuguese natural reference soil PTRS1, from a granitic region, was thereby applied as test substrate. This study allowed the determination of NOEC, LOEC, EC20 and EC50 values for uranium. Dehydrogenase and urease enzymes displayed the lowest values (34.9 and ,134.5 mg U Kg, respectively). Eisenia andrei and Enchytraeus crypticus revealed to be more sensitive to uranium than Folsomia candida. EC50 values of 631.00, 518.65 and 851.64 mg U Kg were recorded for the three species, respectively. Concerning plants, only Lactuca sativa was affected by U at concentrations up to 1000 mg U kg1. The outcomes of the study may in part be constrained by physical and chemical characteristics of soils, hence contributing to the discrepancy between the toxicity data generated in this study and that available in the literature. Following the assessment factor method, a predicted no effect concentration (PNEC) value of 15.5 mg kg21dw was obtained for U. This PNEC value is proposed as a SSV for soils similar to the PTRS1

Natural Radionuclides Content of some Local Cereals in Akura, South Western Nigeria

The natural radionuclides contents of cowpea (Vigna unguiculata L walp), guinea corn (Sorghum bicolor L), rice (Oryza sativa L) and soyabean (Glycin max L) have been investigated. The specific activities ranged from 36.4 ± 13.5 Bqkg-1 to 186.9 ± 23.1 Bqkg-1 for 40K, 0.2 ± 0.1 Bqkg-1 to 1.4 ± 0.5 Bqkg-1 for 238U, and 0.3 ± 0.1 Bqkg-1 to 1.8 ± 0.7 Bqkg-1 for 232Th. Cesium - 137 was not detected in any of the cereals investigated. (Nigeria Journal of Pure and Applied Physics: 2003 2 (1): 34-35

Design and Construction of an Infrared Activated Entrance and Exit Counting Device

This paper presents the design procedure and construction of a low powered entrance and exit counting device. It uses infrared activated transmitter and receiver. The particular circuits that have been employed have been constructed using available components. The counter is capable of counting solid objects to a maximum value of nine thousand nine hundred and ninety nine. (Nigeria Journal of Pure and Applied Physics: 2003 2 (1): 54-58

Health Detriment Associated with Exposure to Natural Radioactivity from the Soil of Ondo and Ekiti States South Western, Nigeria

The health detriment associated with human exposure to primordial radionuclides from the earth crust has been a major source of concern to public health observers across the globe. The level of such detriment can be mitigated by continuous monitoring in order to ascertain that the safe threshold is maintained from time to time. In the light of the above, the activity concentrations of naturally occurring radioactivity (i.e 232Th, 226Ra and 40K) were determined in seventeen soil samples collected from selected cities across Ondo and Ekiti States using gamma ray spectrometry. The measured activity concentrations ranged from 31.93±1.77 to 227.50±4.43 Bq Kg-1 for 232Th, 45.60±2.99 to 210.36±8.76 Bq Kg-1 for 226Ra, 364.89±6.40 to 1274.57±12.48 Bq Kg-1 for 40K, and 48.64±2.04 to 207.22±5.50 Bq Kg-1 for 232Th, 73.52±3.81 to 209.15±7.45 Bq Kg-1 for 226Ra, 542.26±10.41 to 2348.86±21.83 Bq Kg-1 for 40K for Ondo and Ekiti States, respectively. Absorbed dose was calculated using the measured activity concentrations. The mean absorbed dose rate and standard deviation in nGy h-1 were 140.89±65.27 and 173.27±85.40 for Ondo and Ekiti States, respectively. These results are beyond the limits (30 nGy h-1-70 nGy h-1) recommended by UNSCEAR, 1988 for area of normal background radiation. Health detriment to various organs of the body resulting from the exposure scenario was evaluated

Fermentation and Exrusion Effects on the In Vitro Proteinand Starch Digestibility of Unripe Plantain and Pigeon Pea Blends

This study investigated effects of fermentation and extrusion on the in vitro protein andstarch digestibility of unripe plantain and pigeon pea blends. The blended samples were set-up in three arrangements (A=100g unripe plantain; B= 70g unripe plantain: 30g pigeon pea; C= 50g unripe plantain: 50g pigeon pea) and divided into four batches (i.e. first batch = preconditioned and fermented; second batch = extruded; third batch = fermented and extruded; and fourth batch = unfermented/unextruded). Semi-solid state method of fermentation was deployed to ferment blended samples for 96 hours. The pH, temperature and total titratable acidity (TTA) of these samples were evaluated. Fifteen microorganisms comprising 9 bacteria, 2 yeasts and 4 molds were isolated and identified as; Bacillus subtilis, Bacillus cereus, Micrococcus luteus, Staphylococcus aureus, Lactobacillus plantarum, Lactobacillus fermentum, Leuconostocmesenteroides, Lactobacillus mali, Streptococcus lactis, Saccharomyces cerevisiae, Candida utilis, Aspergillusniger, Aspergillusfumigatus, Aspergilluscandidus, and Mucorhiemalis. There were notable variation in the values of pH and total titratable acidity (TTA) during fermentation. The processes of fermentation and extrusion significantly amplified the in vitro starch digestibility of the flour blends with fermented extruded samples (51.03±0.02 to 55.19±0.02mg/ml) unlike theraw flour blends (36.77±0.20 to 41.26±0.003mg/ml).The in vitro protein digestibility significantly increased with the extruded fermented samples (12.73±0.17 to 15.45±0.06mg/ml) and lowest forraw flour blends (4.57±0.29 to 5.98±0.37mg/ml). Hence, it can be concluded based from the available information from this study that fermentation and extrusion increase the in vitro starch digestibility and protein digestibility of unripe plantain and pigeon pea blends

Inherent Microorganisms Affects the Quality of a Nigerian Fermented Beverage “Agadagidi” During Production

This research produced wine from unripe plantain fruits using spontaneous fermentation method. The period of production was five days. The purpose of this study was to isolate and identify microorganisms associated with unripe plantain fruits, determine the physicochemical parameters of the fermenting medium. Microbial count, foaming density, alcohol content, enzymes assay, sensory analysis, physicochemical properties, mineral content, antioxidants properties, and antinutrient content of the sample were investigated every 24 h for 5 days. A total of seven bacteria and four fungi consisting of yeasts and moulds were isolated during the study. The microbial loads of bacteria and fungi of the unfermented plantain fruits were 8.0 × 106 ± 0.01 cfu/mL and 14.2 × 104 ± 0.01 sfu/mL respectively. The temperature (ºC), pH and titratable acidity (%) ranged from 25.55-32.50, 4.51-5.50 and 0.99-3.50 respectively. The sample was observed to be colourless all through the fermentation periods. Turbidity of the samples increased during fermentation from 43.50 to 111.00. The data obtained from this work has shown the importance of unripe plantain micro-flora in the production of “Agadagidi”. It is also concluded that consortium of microorganisms inherent within the plantain fruits are involved in plantain fruits fermentation. This information can contribute to a better understanding of the “Agadagidi” production process for a consistent quality beverage

Evolution from quasivibrational to quasirotational structure in 155Tm and yrast 27/2− to 25/2− energy anomaly in the A ≈ 150 mass region

CITATION: Liu, L., et al. 2018. Evolution from quasivibrational to quasirotational structure in 155Tm and yrast 27/2− to 25/2− energy anomaly in the A ≈ 150 mass region. Physical Review C, 97(4):044306, doi:10.1103/PhysRevC.97.044306.The original publication is available at https://journals.aps.org/prcExcited states in 155Tm have been populated via the reaction 144Sm(16O, p4n)155Tm at a beam energy of 118 MeV. The ground-state band has been extended and a new side band of the ground-state band is identified. E-GOS curves and potential energy surface calculations are employed to discuss the structure evolution of the ground-state band. The newly observed side band in 155Tm is discussed based on the spin/energy systematics. In particular, the phenomenon of seniority inversion is proposed in 155Tm, and a systematic study of this phenomenon in the A ≈ 150 mass region is performed.https://journals.aps.org/prc/abstract/10.1103/PhysRevC.97.044306Publisher's versio