Perovskite Strontium Doped Rare Earth Manganites Nanocomposites and Their Photocatalytic Performances

Studying catalysts in situ is an important topic that helps us to understand their surface structure and electronic states in operation. Three types of materials are used in the degradation of organic matter, which has applications in the environmental remediation and self -cleaning surfaces. The technique is widely known but still hampered by one significant limitation. The materials generally absorb ultra violet UV light but we need to develop active materials for visible light. Utilizing the sunlight efficiently for solar energy conversion is an important demand in the present time. The research on visible-light active photocatalysts attracted a lot of interest. The perovskite-like compounds are found to be active catalysts for the oxidation of carbon monoxide. In the present chapter, we will focus on the application of the nano-sized strontium doped neodymium manganites within perovskite like structure as photocatalysis and studying their photocatalytic performance

Internal friction of ion exchanged Li₂O•Al₂O₃•2SiO₂ glasses

Li₂O•Al₂O₂•2SiO₂ glass fibers were ion-exchanged from 1 to 300 minutes in a sodium nitrate bath at 366ºC. The internal friction was measured along with the lithium and sodium concentration profiles. As sodium progressively replaced lithium, the alkali internal friction peak became smaller while a new peak (mixed alkali peak) appeared and increased in magnitude. These changes in the internal friction are similar to those that occur upon the addition of a second alkali to glasses prepared by conventional melting. The magnitude of both internal friction peaks in ion exchanged glasses was dependent on the overall glass composition. The magnitude of the alkali peak depended upon the unexchanged glass core, whereas that of the mixed alkali peak depended upon the exchanged layer on the glass surface. Dissolving the exchanged surface layer led to the restoration of the original alkali peak and the disappearance of the mixed alkali peak. Changing the alkali distribution did not affect much the mixed alkali peak, but caused the alkali peak to shift to higher temperatures and become smaller. The activation energy for both peaks remained essentially constant during ion exchange of the chilled fibers and this is attributed to the rigid network structure at 366ºC. The height of the alkali peak can be used to determine the maximum depth of penetration of the second alkali --Abstract, pages iv-v

Spectrophotometric studies on some nitrosonaphthols

1018-1021The UV and visible absorption spectra of some nitrosonaphthol derivatives have been studied in organic solvents of varying polarities. The dependence of the band shift on the nature of substituent, dielectric effect and specific solvation has been studied. The absorption spectra have also been studied in buffer solutions of varying pH values and the acid dissociation constants of the different ionisable groups have been determined using the half-height and the modified limiting absorbance methods. It is found that the nitroso substituent leads to a decrease in ionisation constants of the naphthalenic OH group

Achieving Information Security by multi-Modal Iris-Retina Biometric Approach Using Improved Mask R-CNN

The need for reliable user recognition (identification/authentication) techniques has grown in response to heightened security concerns and accelerated advances in networking, communication, and mobility. Biometrics, defined as the science of recognizing an individual based on his or her physical or behavioral characteristics, is gaining recognition as a method for determining an individual\u27s identity. Various commercial, civilian, and forensic applications now use biometric systems to establish identity. The purpose of this paper is to design an efficient multimodal biometric system based on iris and retinal features to assure accurate human recognition and improve the accuracy of recognition using deep learning techniques. Deep learning models were tested using retinographies and iris images acquired from the MESSIDOR and CASIA-IrisV1 databases for the same person. The Iris region was segmented from the image using the custom Mask R-CNN method, and the unique blood vessels were segmented from retinal images of the same person using principal curvature. Then, in order to aid precise recognition, they optimally extract significant information from the segmented images of the iris and retina. The suggested model attained 98% accuracy, 98.1% recall, and 98.1% precision. It has been discovered that using a custom Mask R-CNN approach on Iris-Retina images improves efficiency and accuracy in person recognition

The role of losartan and enalapril in the protection against stress-induced gastric mucosal ulceration in rats

Background: Angiotensin II (ANG II) is a stress hormone and its level dramatically increases in the stomach during stress. In addition, it generates reactive oxygen species (ROS) with cellular damage and inflammation. So the aim of this study is to evaluate the mechanism of losartan and enalapril in the prevention of stress-induced gastric ulcer through their action on mucosal prostaglandin (PGs) and antioxidant enzymes and compare between them.Methods: Thirty- six adult male wistar albino rats weighing 180-200 g were divided into 6 groups; n= 6. Groups 1, 2, and 3 were received saline (normal control), losartan (3 mg/kg/day) and enalapril (10 mg/kg/day) i.p respectively for 4 weeks. Groups 4, 5, and 6 were pretreated with saline (ulcer control), losartan (3 mg/kg/day) and enalapril (10 mg/kg/day) i.p respectively for 4 weeks duration. On 29th day, group 4, 5 and 6 were submitted to gastric ulcer by water immersion method, then animals of all groups were sacrificed, stomachs were excised for gross and microscopic examination and determination of the mucosal levels of prostaglandin E2 (PGE2), superoxide dismutase (SOD), nitric oxide (NO) and catalase (CAT).Results: Stress produced gastric ulcer and a significant decrease in all measured gastric parameters compared to normal control group. Pre-treatment of rats with losartan or enalapril decreased the stress-induced alterations in mucosal parameters, but only losartan caused a significant increase in CAT activity in addition.Conclusions: Antagonize the action of ANG II by losartan and enalapril have preventive advantages in stress-induced gastric ulcer and losartan has better influence as it has an additional effect on CAT activity

Exact implicit Solution of Nonlinear Heat Transfer in Rectangular Straight Fin Using Symmetry Reduction Methods

In this paper, the exact implicit solution of the second order nonlinear ordinary differential equation which governing heat transfer in rectangular fin is obtained using symmetry reduction methods. General relationship among the temperature at the fin tip, the temperature gradient at the fin base, the mode of heat transfer, and the fin parameters and ℰ is obtained. Some numerical examples are discussed and it is shown that the temperature of fin increases when approaching from the heat source. The relationship between the fin efficiency and the temperature of fin tip is obtained for any value of the mode of heat transfer . The relationship between the fin efficiency and both the parameter and ε the temperature gradient at the fin base is obtained. To our best knowledge, solutions obtained in this paper are new

Synthesis and efficiency of new pyridine, chromene and thiazole containing compounds as antimicrobial and antioxidant agents

ABSTRACT. The versatile scaffold, N'-(2-cyanoacetyl)-2-hydroxybenzohydrazide (3) was utilized in the production of new pyridine, chromene and thiazole derivatives as antimicrobial and antioxidant agents. The synthetic strategy involves the treatment of precursor 3 with various arylidene-malononitrile and 3-aryl-2-cyanoacrylate compounds to furnish substituted pyridines 5 and 7. The interaction of 3 with salicylaldehyde and/or phenyl isothiocyanate followed by cyclization with chloroacetone produced the corresponding 2-imino-2H-chromene-3-carbohydrazide and (thiazol-2-ylidene-acetyl)-salicylic acid hydrazide compounds 8 and 9, respectively. The structural features of the synthesized compounds were confirmed by using spectroscopic methods such as (IR, 1H NMR, 13C NMR and MS). The new pyridine, chromene and thiazole products showed potent antioxidants and antimicrobial activities. The thiazole derivative 9 exhibited the highest anti-bacterial and antifungal activities against S. aureus (75.0%) and B. subtilis (73.9%) and C. albicans (66.6%). The combination between salicylic acid hydrazide and thiazole moieties in the hybrid 9 indicated the best antioxidant activity (87.9%).                 KEY WORDS: Salicylic hydrazide, Arylidene-malononitrile, Pyridine, Thiazole, Antioxidant   Bull. Chem. Soc. Ethiop. 2022, 36(1), 137-148.                                                            DOI: https://dx.doi.org/10.4314/bcse.v36i1.12                                                      &nbsp

Markers of neural degeneration and regeneration in Down syndrome patients

On the trisomy Down syndrome Critical Region (DSCR1) is located the APP gene, which accelerates amyloid peptide protein (APP) expression leading to cerebral accumulation of APP-derived amyloid-beta peptides (Ab) and age-dependent cognitive sequelae. Also DSCR1 attenuates endothelial cell proliferation and angiogenesis required for tissue repair. The aim of the present work is to determine markers of neural degeneration and regeneration in the blood of young and adolescent Down syndrome (DS) patients as well as controls. Markers of regeneration were measured in terms of circulating mononuclear cells expressing Nestin and CD34, while markers of degeneration were measured in terms of plasma Ab42 and advanced glycation end products receptors (RAGES). Results showed a significant increase in plasma Ab42 (20 ± 5.1 vs. 11.9 ± 3.4) and RAGES leucocytes mRNA relative expression (1.9 ±0.2 vs. 1.1 ±0.6) in adolescentDS patients compared to young DS. Both parameters were also significantly increased in DS compared to controls: Ab42 (15.4 ± 5.9 vs. 12. 3± 4.5); RAGES (1.4 ± 0.5 vs. 0.7± 0.2). Nestin (5.2 ± 1.4 vs. 6.3± 0.6) and CD34 (52 ± 2.5 vs. 53± 4.7) were non-significantly lower in adolescent DS patients compared to young DS, but significantly lower in DS patients compared to controls: Nestin (6.3 ± 1.5 vs. 9±4.4); CD34 (54 ± 3.4 vs. 60± 4.8). The significant decrease in the number of mononuclear cells bearing Nestin and CD34 markers accompanied by a significantincrease in Ab42 and RAGES indicate that degeneration in DS is an ongoing process, which is not counterbalanced by the regenerative mechanism

Correction of anterior hypospadias without urethroplasty: glanular rotation procedure (the Hay technique)

Objectives: The aim was to present a simple technique for the correction of anterior hypospadiases without meatal advancement or urethroplasty.Background: Most of the techniques described for the correction of anterior hypospadias had the risk of complications: recession, flaying of the glans, fistula, and meatal stenosis that is not accepted when dealing with a trivial anomaly that is done only for cosmetic correction. A simple technique for correcting granular and some forms of coronal hypospadias without meatal advancement or urethroplasty is presented.Patients and methods: From June 2013 to June 2016, 183 patients presented for surgical repair of glanular or coronal hypospadias. The technique of glanular rotation procedure (GRP) was applied only for those cases that matched the criteria settled after degloving of the penis with an incision made 2mm proximal to the meatus touching the glans on both sides for 3–4 mm. Once the uppermost part of the meatus is at the same line with the upper end of the glans on both sides, the technique is applicable. The patients were followed in the OPD for 1 year after the repair for the evaluation of the results of the technique: the urinary stream, meatal size and position, presence of fistula, and the final cosmetic appearance.Results: Ninety-eight out of 183 (53.6%) boys had matched the criteria for application of the GRP technique. Their age ranged from 6 months to 3 years. All but three had an apical, slit-like meatus with good stream without stenosis and 2–3mm glans tissue encircling the ventral side of the meatus. Four cases had complications in the form of meatal stenosis in two cases, disruption of the glans in one case, and coronal fistula in one case. The overall complication rate was 4.1%.Conclusion: In properly selected cases, GRP is a simple efficient technique that has the advantage of reconstructing the glans over the urethra without the need of meatal advancement or urethroplasty.Keywords: coronal hypospadias, glanular hypospadias, without urethroplast

Stochastic Processes in Yellow and Red Pulsating Variables

Random changes in pulsation period are well established in cool pulsating stars, in particular the red giant variables: Miras, semi-regulars of types A and B, and RV Tau variables. Such effects are also observed in a handful of Cepheids, the SX Phe variable XX Cyg, and, most recently, the red supergiant variable, BC Cyg, a type C semi-regular. The nature of such fluctuations is seemingly random over a few pulsation cycles of the stars, yet the regularity of the primary pulsation mechanism dominates over the long term. The degree of stochasticity is linked to the dimensions of the stars, the randomness parameter 'e' appearing to correlate closely with mean stellar radius through the period 'P', with an average value of e/P = 0.0136+-0.0005. The physical processes responsible for such fluctuations are uncertain, but presumably originate in temporal modifications of envelope convection in such stars.Comment: Poster given at the "Stellar Pulsation: Challenges for Theory and Observation" conference in Santa Fe, New Mexico (2009