290 research outputs found

    Influence of Incomplete Fusion Reaction on Complete Fusion Below 10 Mev/ Nucleon Energies

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    An attempt has been made in the present work to provide an ample opportunity to explore the information about the influence of incomplete fusion (ICF) reaction dynamics on complete fusion in heavy ion induced nuclear reactions. excitation functions for several evaporation residues produced in the interaction of projectile 16O with target 175lu have been measured over the wide projectile energy range ≈ 70-100 MeV. the recoil-catcher activation technique followed by the offline γ-ray spectroscopy has been used for the present measurements. In case of precursor decay, we have made use of Cavinato et al. formulation to calculate the independent cross-section of the identified residues. the measured efs are compared with theoretical predictions of statistical model code PACE-2 and any enhancement in the measured cross-section from theoretical prediction may be due to ICF reaction process. An attempt has been made to estimate the ICf contribution of the cross-section from the measured excitation function data and the dependence of ICf cross-section on projectile energy

    Disentangling of incomplete fusion dynamics at low energies ≈ 4-6 MeV/A

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    An experiment has been performed for the measurements of forward recoil range distributions (FRRDs) of evaporation residues (ERs) using 16O beam on the target 148Nd to explore the incomplete fusion (ICF) dynamics at low projectile energy ≈ 4-6 MeV/A. In the present work, FRRDs of ERs 159,158Er(xn), 160g,159Ho(pxn), 157,155Dy(αxn) and 155Tb(αpxn) have been measured. The measured FRRDs of ERs have been compared with their theoretical mean ranges, calculated using code SRIM. These present results obtained from FRRDs measurements show that full and partial linear momentum transfer components are involved. This indicates that the ERs populated through α-emission channels are not only produced via complete fusion, but also through incomplete fusion dynamics. The present analysis indicates that the incomplete fusion contribution increases with projectile energy. This increment in incomplete fusion contribution is due to the increase in breakup probability of projectile 16O into 12C + 4He/ α with projectile energy

    Disentangling of incomplete fusion dynamics at low energies ≈ 4-6 MeV/A

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    371-375An experiment has been performed for the measurements of forward recoil range distributions (FRRDs) of evaporation residues (ERs) using 16O beam on the target 148Nd to explore the incomplete fusion (ICF) dynamics at low projectile energy ≈ 4-6 MeV/A. In the present work, FRRDs of ERs 159,158Er(xn), 160g,159Ho(pxn), 157,155Dy(αxn) and 155Tb(αpxn) have been measured. The measured FRRDs of ERs have been compared with their theoretical mean ranges, calculated using code SRIM. These present results obtained from FRRDs measurements show that full and partial linear momentum transfer components are involved. This indicates that the ERs populated through α-emission channels are not only produced via complete fusion, but also through incomplete fusion dynamics. The present analysis indicates that the incomplete fusion contribution increases with projectile energy. This increment in incomplete fusion contribution is due to the increase in breakup probability of projectile 16O into 12C + 4He/ α with projectile energy

    Preparation and Evaluation of Nano-vesicles of Brimonidine Tartrate as an Ocular Drug Delivery System

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    The objective of the present investigation was to design a vesicular formulation of brimonidine tartrate and evaluate its ability to reduce the dosing frequency and improve the therapeutic efficacy of the drug. Nano-vesicles of brimonidine tartrate were prepared by film hydration method. The prepared vesicles were evaluated for photomicroscopic characteristics, entrapment efficiency, in vitro, and ex-in vitro drug release and in vivo intraocular pressure (IOP) lowering activity. The methods employed for preparation of vesicles produced nano vesicles of acceptable shape and size. The in vitro, and ex-in vitro drug release studies showed that there was slow and prolonged release of the drug, which followed zero-order kinetics. The IOP-lowering activity of nano vesicles was determined and compared with that of pure drug solution and showed that the IOP-lowering action of nano-vesicles sustained for a longer period of time. Stability studies revealed that the vesicle formulations were stable at the temperature range of 2-8°C, with no change in shape and drug content. The results of the study indicate that it is possible to develop a safe and physiologically effective topical formulation that is also convenient for patients

    Effect of projectile breakup in the system 19F + 154Sm

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    386-391An attempt was made to understand the role of various entrance channel parameters on incomplete fusion dynamics by the measurements of excitation functions of evaporation residues populated via complete and incomplete fusion dynamics in the system 19F + 154Sm at projectile energy ≈ 4-6 MeV/A. The stacked foil activation technique followed by offline gamma ray spectrometry was employed in these measurements. The measured excitation functions of various evaporation residues populated have been analyzed within the framework of statistical model code PACE-4. It has been observed that the measured excitation functions of xn and pxn emission channels agree well with the theoretical predictions of PACE-4. On the other hand, the measured excitation functions of α-emission channels have been found significantly enhanced over their theoretical predictions. This enhancement may be attributed to the incomplete fusion of the projectile 19F as the calculations for incomplete fusion are not included in statistical model calculations. The incomplete fusion fraction has been deduced from the present measurements. Further, a systematic study has also been performed, which shows that the incomplete fusion increases significantly with entrance channel mass asymmetry at low projectile energy, differently for different projectiles

    Effect of projectile breakup in the system 19F + 154Sm

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    An attempt was made to understand the role of various entrance channel parameters on incomplete fusion dynamics by the measurements of excitation functions of evaporation residues populated via complete and incomplete fusion dynamics in the system 19F + 154Sm at projectile energy ≈ 4-6 MeV/A. The stacked foil activation technique followed by offline gamma ray spectrometry was employed in these measurements. The measured excitation functions of various evaporation residues populated have been analyzed within the framework of statistical model code PACE-4. It has been observed that the measured excitation functions of xn and pxn emission channels agree well with the theoretical predictions of PACE-4. On the other hand, the measured excitation functions of α-emission channels have been found significantly enhanced over their theoretical predictions. This enhancement may be attributed to the incomplete fusion of the projectile 19F as the calculations for incomplete fusion are not included in statistical model calculations. The incomplete fusion fraction has been deduced from the present measurements. Further, a systematic study has also been performed, which shows that the incomplete fusion increases significantly with entrance channel mass asymmetry at low projectile energy, differently for different projectiles

    Determination of putative virulence factors among clinical isolates of enterococci isolated from a military hospital in the eastern province of Saudi Arabia

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    Background: The pathogenic potential of enterococci to produce life-threatening infections is well-documented. The scientific community has, of late, evinced a renewed interest in the putative virulence factors of enterococci. Objective of the study was to determine the putative virulence factors of clinically isolated Enterococcus species from a military hospital and to describe the association between virulence factors and vancomycin susceptibility.Methods: A total of 245 enterococci were isolated from clinical samples collected from KFMMC, a leading military hospital in the eastern province of Saudi Arabia. Following species identification and antimicrobial susceptibility testing using the Vitek 2 system; the isolates were tested for the production of caseinase, gelatinase, biofilm, and presence of haemolysin.Results: Among the enterococcal isolates, 36.7% produced caseinase, 38% produced gelatinase, 24.1% exhibited biofilm formation, and 30.6% were positive for haemolytic activity. A significant association between vancomycin susceptibility patterns and the virulence factors, gelatinase and haemolytic activity, were noted. No significant associations were observed between vancomycin susceptibility patterns and the presence of caseinase or the formation of biofilms.Conclusions: Virulence factors are invariably produced by several clinical isolates of enterococci in our hospital, and some virulence factors are associated with vancomycin susceptibility

    Smart cities, social media platforms and security: online content regulation as a site of controversy and conflict

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    Abstract Smart, technologically managed city-regions are one of the main characteristics of the contemporary world. Since the attack to the Charlie Hebdo offices, city-regions and social media digital technologies have increasingly been changing the definition of 'territory of security' and 'security governance'. What are the characteristics of the security architecture created by the interaction of smart city-regions and digital technologies? Drawing from Actor-Network theory and Science and Technology Studies, we provide an empirical account of the shape of this new territory, by presenting a study of the controversy concerning security and social media in UK, the role of cities in this changed security space, and how social sciences can help better understand and respond to the opportunities and threats of smart cities

    Validacija topokemijskih modela za predviđanje permeabilnosti kroz krvno-moždanu barijeru

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    Recently published topochemical models for permeability through the blood-brain barrier were validated and cross-validated in the present study. Five models based on three topochemical indices, Wiener’s topochemical index - a distance-based topochemical descriptor, molecular connectivity topochemical index - an adjacency-based topochemical descriptor and eccentric connectivity topochemical index - an adjacency-cum-distance based topochemical descriptor, for permeability of structurally and chemically diverse molecules through blood-brain barrier were used in the present investigation. A data set comprising 62 structurally and chemically diverse compounds was selected. This data set was divided into two sets of 31 compounds each - one to serve as the validation set and other as the cross-validation set. The values of all the three-topochemical indices in the original as well as in the normalized form for each of the 31 compounds of the validation set were computed using an in house computer program. Resultant data was analyzed and each compound was assigned a permeability characteristic using topochemical models, which was then compared with the reported permeability through the blood-brain barrier. Accuracy of prediction of these models was calculated. The same procedure was similarly followed for the cross-validation set. Studies revealed accuracy of prediction of the order of 7080% during validation. Surprisingly, very high predictability of the order of 7791% was observed during cross-validation. High predictability observed during validation as well as cross-validation authenticates topochemical models for prediction of permeability through the blood-brain barrier.U ovom radu su validirani i unakrsno validirani nedavno objavljeni topokemijski modeli za permeabilnost kroz krvno-moždanu barijeru. Predviđanje prolaska kroz krvno-moždanu barijeru strukturno i kemijski različitih molekula provedeno je na pet modela koji se temelje na tri topološka indeksa, Wienerovom topološkom indeksu, topološkom indeksu molekularne povezanosti i topološkom indeksu ekscentrične povezanosti. Ukupno 62 spoja podijeljena su u dva seta koji su sadržavali 31 spoj. Jedan set upotrebljen je za validaciju, a drugi za unakrsnu validaciju. Vrijednosti svih triju topoloških indeksa u početnom setu i u normaliziranom setu su računate pomoću kompjutorskog programa. Rezultati su analizirani i svakom spoju je pridružena teorijska vrijednost permeabilnosti, koja je zatim uspoređivana s objavljenim eksperimentalnim podacima za permeabilnost kroz krvno-moždanu barijeru. Točnost predviđanja bila je između 70 i 80%. Isti postupak je proveden za unakrsno validacijski set, a točnost je bila iznenađujeće velika (7791%), što ukazuje da se upotrebljeni topokemijski modeli mogu upotrijebiti za predviđanje permeabilnsot kroz krvno-moždanu barijeru
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