Journal of physical chemistry & biophysics最新文献

{"title":"Radiological Impacts of Natural Radioactivity in Locally Produced Tobacco Products in Oyo State, Nigeria","authors":"Akinyose Fc, P. Tchokossa, Orosun Mm, Mark Ib, K. K. Ochommadu, S. Oluyide","doi":"10.4172/2161-0398.1000262","DOIUrl":"https://doi.org/10.4172/2161-0398.1000262","url":null,"abstract":"Radionuclides are found naturally in air, water and soil. They are even found in vegetation, consumer products and in human body. Everyone on the planet is exposed to some background level of ionizing radiation through external exposures that occurs as a result of irradiation, and internal exposures that occurs as a result of ingestion and inhalation. Studies have shown that tobacco contains minute quantities of radioisotopes from uranium and thorium-decay series which are radioactive and carcinogenic. Tobacco product increases both external and internal exposure due to these radioisotopes. In fact, tobacco products have been considered to be one of the most significant causes of lung cancer. Owing to the large-scale consumption of tobacco in Nigeria at the present time, locally produced tobacco products in Nigeria were collected from the market and the naturally-occurring 238U and 232Th decay series, as well as non-series decay 40K in these products were measured using γ-ray spectrometer. The radiological impacts of the radionuclides in these products were assessed from their specific activities. The average values of the absorbed dose rate were 19.72 and 17.59 nGy h-1 for snuff and cigarette products respectively. The average values of the effective doses due to daily inhalation of smoke by consumers from one (1) stick of cigarette and one (1) wrap of snuff products were 66.62 and 592.32 μSv yr-1 respectively. Similarly, the values of the radium equivalent activity index for snuff and cigarette samples were 40.95 and 38.95 Bq kg-1 respectively. Also, the external radiation hazard index was 0.12 and 0.11 for snuff and cigarette samples respectively while the internal radiation hazard index was 0.17 and 0.15 for the two samples respectively. The average excess lifetime cancer risk (× 10-3) values for daily inhalation of smoke from one (1) stick of cigarette and one (1) wrap of snuff were 0.23 and 2.07 × 10-3 respectively. The estimated values of some of these parameters were found to be lower than the recommended limit by UNSCEAR (2000). However, the effective dose poses a serious health risk to addicted consumers of the product and passive smokers in the environment when three (3) or more wraps of snuff and one (1) or more packs of cigarette products are consumed daily. The mean excess lifetime cancer risks values estimated were also much higher than the recommended limits by UNSCEAR (2000). This then makes the risk of suffering cancer and other radiation injuries to be high.","PeriodicalId":94103,"journal":{"name":"Journal of physical chemistry & biophysics","volume":"19 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75620967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"QSPR and DFT Studies on the Melting Point of Carbocyclic Nitroaromatic Compounds","authors":"B. Elidrissi, A. Ousaa, M. Ghamali, Samir CHTITA, M. A. Ajana, M. Bouachrine, T. Lakhlifi","doi":"10.4172/2161-0398.1000245","DOIUrl":"https://doi.org/10.4172/2161-0398.1000245","url":null,"abstract":"A quantitative structure-property relationship (QSPR) study was performed to predict the melting points of 60 carbocyclic nitroaromatic compounds using the electronic and topologic descriptors computed respectively, with ACD/ ChemSketch and Gaussian 03W programs. The structures of all 60 compounds were optimized using the hybrid density functional theory (DFT) at the B3LYP/6-31G(d) level of theory. In both approaches, 50 compounds were assigned as the training set and the rest as the test set. These compounds were analyzed by the principal components analysis (PCA) method, a descendant multiple linear regression (MLR) analyses and an artificial neural network (ANN). The robustness of the obtained models was assessed by leave-many-out cross-validation, and external validation through test set. This study shows that the PCA and MLR have served also to predict melting point and some other physicochemical properties, but when compared with the results given by the ANN (R=0.997), we realized that the predictions fulfilled by this latter were more effective and much better than other models.","PeriodicalId":94103,"journal":{"name":"Journal of physical chemistry & biophysics","volume":"50 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2017-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79763691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Specific Heat of Solution of HCl-NaOH Reaction by a Simple Handmade Calorimeter","authors":"M. Fazal-ur-Rahman, Hafiz Zeshan Haider","doi":"10.4172/2161-0398.1000261","DOIUrl":"https://doi.org/10.4172/2161-0398.1000261","url":null,"abstract":"A research study was performed by couple of students under the research project of bachelor in chemistry. The main goal to perform this project was to determine the changes in temperature of solution when an acid and a base were mixed together inside the cups of handmade calorimeter and their reaction was proceeded under the lab conditions and to determine either reaction would be exothermic or endothermic. Basically, from these changes in temperature of solution, the specific Heat of solution or Heat of reaction was determining. Temperature changes were observed using analytical thermometer with stop watch and all changes were noted on datasheet, while after completion of the whole experimental work, a thermodynamic equation of specific Heat was applied to calculate the Specific Heat of solution mathematically in numeric value which was 3214.72476 J or 3.21472 KJ. It was seen that as the base was mixed into acid, the temperature of solution was increased to maximum rapidly showing the exothermic reaction. After reaching to maximum range, the temperature decreased gradually to its minimum range being constant and consistent. The consistent temperature range terminated the reaction. All variations in temperature ranges were recorded very carefully and a table with a graph showing all ups and downs in temperature ranges was drawn on MS Excel Data Sheet.","PeriodicalId":94103,"journal":{"name":"Journal of physical chemistry & biophysics","volume":"7 1","pages":"1-3"},"PeriodicalIF":0.0,"publicationDate":"2017-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79106578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The System of Medical Application System Application of the Difference between the Fuzzy Logic and the Neural Networks","authors":"Kadhim Ajeel Obaid","doi":"10.4172/2161-0398.1000258","DOIUrl":"https://doi.org/10.4172/2161-0398.1000258","url":null,"abstract":"Singled out for this research study the issue of fuzzy logic and use in the medical field to set the values estimated for the data thalassemiapatients, as well as the research involved a study hybridization fuzzy logic with artificial neural networks and the application form hybrid data and note the accuracy of the results between the two systems, which proved to form hybrid superiority large in the accuracy of results compared with the system fuzzy.","PeriodicalId":94103,"journal":{"name":"Journal of physical chemistry & biophysics","volume":"46 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2017-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76384355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Threshold photoelectron and electron-ion coincidence spectroscopies: Past, present and future","authors":"R. Tuckett, T. Baer","doi":"10.4172/2161-0398-C1-025-011","DOIUrl":"https://doi.org/10.4172/2161-0398-C1-025-011","url":null,"abstract":"","PeriodicalId":94103,"journal":{"name":"Journal of physical chemistry & biophysics","volume":"71 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86167901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multidimensional solitons in dispersive complex media: Structure and stability","authors":"V. Belashov","doi":"10.4172/2161-0398-C1-021","DOIUrl":"https://doi.org/10.4172/2161-0398-C1-021","url":null,"abstract":"","PeriodicalId":94103,"journal":{"name":"Journal of physical chemistry & biophysics","volume":"98 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76552160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of Adsorption Process of Hydrogen on Fe-Ti: Theoretical Simulation and Interpretation of Isotherms with Statistical Physics Treatment","authors":"M. Manaa, M. Hachicha, B. Schmaltz, Ben Lamine Abdelmottaleb","doi":"10.4172/2161-0398.1000260","DOIUrl":"https://doi.org/10.4172/2161-0398.1000260","url":null,"abstract":"Three theoretical expressions for the adsorption isotherms of hydrogen on Fe-Ti at three temperatures 100 K, 80 K and 60 K have been established. Our objective in this modeling is to select the adequate model that presents a high correlation with the experimental curves. The establishment of these new expressions is based on statistical physics formalism. This method has allowed the estimation of physicochemical parameters in the theoretical model. The parameters intervening in the adsorption process have been deduced directly from experimental adsorption isotherms by numerical simulation. We will mainly introduce three main parameters affecting the adsorption process, namely: the density of hydrogen receptor sites Nm, the number of molecules per site n and the pressure at half saturation P1 which characterizes the binding between the hydrogen and receptor sites on Fe-Ti. Then we apply the model to calculate the internal energies in an isothermal transformation, an isobaric transformation and an isosteric transformation.","PeriodicalId":94103,"journal":{"name":"Journal of physical chemistry & biophysics","volume":"6 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2017-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74238141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chitosan Hydrogels and their Glutaraldehyde-Crosslinked Counterparts as Potential Drug Release and Tissue Engineering Systems - Synthesis, Characterization, Swelling Kinetics and Mechanism","authors":"O. Akakuru, B. Isiuku","doi":"10.4172/2161-0398.1000256","DOIUrl":"https://doi.org/10.4172/2161-0398.1000256","url":null,"abstract":"Snail shells had been utilized to prepare chitosan and hydrogels of the chitosan were also prepared and crosslinked with varying amounts of glutaraldehyde to achieve different crosslink densities between 0.75 and 1.50. The materials were characterized in terms of the dependence of their swellabilities on time and pH. FTIR analysis was also carried out on the hydrogels and the results obtained show a band at 3451 cm-1, attributed to O-H stretching of the chitosan. The crosslinked hydrogels also showed an N-H bending vibration at 1635 cm-1 which has a reduced intensity and has moved to a lower wavenumber when compared to the N-H bending vibration of the uncrosslinked chitosan hydrogels at 1652 cm-1. The swelling studies showed that the extent of swelling of the hydrogels was dependent on the crosslink density (CD), increasing as CD increased. Uncrosslinked chitosan hydrogel had maximum swelling of 162.71% while that for the crosslinked chitosan hydrogels with CD of 0.75, 1.00 and 1.50 were 119.87%, 93.21% and 87.65% respectively. In all cases, their crosslinked counterparts had decreased swellabilities suggesting that, the crosslinked chitosan hydrogels can be used for a more controlled delivery of drugs and as efficient materials for tissue engineering. The chitosan hydrogels showed maximum percent swellability in highly acidic medium (pH2) equally suggesting the potential of these hydrogels as drug release systems in this medium. The swelling of the chitosan hydrogels followed second-order kinetics and their swelling diffusion exponents ranged from 0.142 to 0.155, indicative of a Less Fickian diffusion or transport mode.","PeriodicalId":94103,"journal":{"name":"Journal of physical chemistry & biophysics","volume":"37 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2017-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91320727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Radioactivity: An Introduction to Mysterious Science","authors":"N. Khan","doi":"10.4172/2161-0398.1000254","DOIUrl":"https://doi.org/10.4172/2161-0398.1000254","url":null,"abstract":"Materials that undergo decay process to attain a stable configuration followed by the emission of particles such as alpha, beta and gamma are termed as radioactive elements. Radioactivity is measured in Curie (Ci) and Becquerel (Bq) SI units. Though radioactive elements are abundant on Earth and constantly decays to produce stable nuclei but such nuclear decay process may pose serious health threats to living beings. Therefore, must be regulated when working in vitro. Biosafety levels should be strictly observed when engaged in radioactive experiments to minimize contamination exposure.","PeriodicalId":94103,"journal":{"name":"Journal of physical chemistry & biophysics","volume":"46 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2017-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86345789","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinetics and Solvent Effect in Hydrolysis of Ethyl Cinnamate in Water- Methanol Mixture","authors":"S. Ak","doi":"10.4172/2161-0398.1000252","DOIUrl":"https://doi.org/10.4172/2161-0398.1000252","url":null,"abstract":"The solvent effect of ethanol on the alkali catalyzed solvolysis reaction was studied by carring out of the hydrolysis of ester namely ethyl cinnamate in water-methanol media of varying composition consisting of 30 to 70% of methanol (v/v) at different Temperature ranging from 20°C to 70°C. The Specific rate constant values of the reaction were found to depleted with increasing concentration of methanol in reaction media. Enhancement in ΔG* with simultaneous depletion in ΔH* and ΔS* of the reaction, it has been concluded that reaction is enthalpy stimulating and entropy inhibiting and specific salvation take place in water- methanol media. From the evaluated value of Iso kinetic temperature, which is less than 300 indicates that this reaction in water-methanol media obey Barclay-Butler rule and there is weak but considerable solvent –solute interaction taking place in reaction media.","PeriodicalId":94103,"journal":{"name":"Journal of physical chemistry & biophysics","volume":"1 1","pages":"1-4"},"PeriodicalIF":0.0,"publicationDate":"2017-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90326187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}