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Volume 8 Number 1 January 2022

Gamma Irradiation to Sterilize Active Ingredients, Consumer Foodstuffs and Beverages in Bangladesh


Authors: Hasan M. Zahid ; Mohammad Zahirul Islam Mollah ; Ruhul A Khan
Pages: 33-37
DOI: doi.org/10.32861/sr.81.33.37
Abstract
Nowadays, the utilization of gamma irradiation (e.g., Cobalt-60 source) to sterilize different materials have been increasing enormously. As terminal sterilization, gamma irradiation is being used popularly to sterilize different materials throughout Bangladesh. Compare to other conventional methods of sterilization (e.g., alpha, beta, other chemicals), this method is highly applicable for its well acceptance in the world. It has high penetration power with the short wave lengths, isothermal characteristics for its negligible rise in the temperature, no contact with any toxic chemicals without having any unirradiated portion. In this process, the assurance level of the sterility of product is far better than other aseptic processing. The chemical bonds in the microbes are broken to produce reactive oxygen species (ROS) by gamma irradiation, and attack DNA/RNA of microbes for killing. The mutations in the genetic materials (DNA/RNA) of microbes are usually happened through gamma irradiation and consequently restrict the cellular division of microbes. This characteristic of gamma ray is mostly applicable in the commercial purposes. This review discusses the general applications of gamma irradiation to the broaden arena of different materials (active pharmaceutical ingredients, consumer products, beverages etc.). A summarized description of materials those are irradiated using Cobalt-60 source in Bangladesh, in particular, at the Institute of Radiation & Polymer Technology (IRPT), Bangladesh Atomic Energy Commission, is described here. The information may further assist to enhance the dissemination of the applicability of gamma irradiation throughout Bangladesh.

Geospatial Analysis of Soil Erosion Susceptibility and Causative Factors in Anambra State, South East, Nigeria


Authors: Romanus Udegbunam Ayadiuno ; Dominic Chukwuka Ndulue ; Chinemelu Cosmas Ndichie ; Arinze Tagbo Mozie ; Philip O. Phil-Eze ; Anthony Chukwuemeka Onyekwelu
Pages: 5-32
DOI: doi.org/10.32861/sr.81.5.32
Abstract
Land degradation is a function of soil erosion leading to soil loss and reduction in crop productivity as well as other socio-economic activities. The menace of soil erosion is challenging due to diverse factors including advertent and inadvertent anthropogenic activities. This study looks at soil erosion susceptibility and causative factors in Anambra State, both static and dynamic with the intent of identifying them, investigating spatial variability of soil loss, relate erodibility to soil properties and causative factors to soil erosion. Eight (8) prominent causative factors (CFs), were identified. These causative factors (CFs) were analyzed using ArcGIS 10.2. Sixty (60) soil samples were extracted randomly, analyzed, and tested. The study identified CFs such as Drainage Density, Erosion Density, Lineament Density, Slope Length, Land Surface Temperature, and Rainfall Erosivity, which contribute to Soil Erodibility (K - Factor). Land Surface Temperature, Soil Moisture Index, Rainfall Erosivity, and Normalized Difference Vegetation Index contributed to the loss of 8.97 ton/ha/yr, 9.1288 ton/ha/yr, 1,1134.7 ton/ha/yr, and 0.245 ton/ha/yr respectively to erosion in Anambra State. Conclusively, the dynamic causative factors influence soil susceptibility and trigger erosion in the State.

Lack of the Lower Bound for the Shannon Entropy


Authors: J. Ladvánszky
Pages: 1-4
DOI: doi.org/10.32861/sr.81.1.4
Abstract
Shannon entropy is a basic characteristic of communications from the energetic point of view. Despite this fact, an expression for entropy as a function of the signal-to-noise ratio is still missing. In this paper, that shortage has been corrected first. Using that expression, lower bound for entropy has been investigated. We prove that such finite nonzero bound does not exist, therefore there is no theoretical limit for reduction of the effect of noise. The proof is valid for QAM modulation of arbitrary order.