Study of line shape and angular variation of ESR spectra in two smectic a liquid crystals

Electron spin-resonance (ESR) measurement of the androstane nitroxide spin-probe is reported in isotropic, nematic and smectic A phases of the liquid crystals N(p-Octyloxy-benzylidine)-p-toludine [OBT] and p-nitrophenyl-p-n-octyloxy benzoate [NPOB]. Mono-domain samples in flat quartz tube were formed for the study of the angular variation of the spectra in smectic A phase. The analysis of the spectra using the theory of Polnaszek, Bruno and Freed (PBF) has resulted in the determination of the order parameter S, the rotational correlation time TR, and the anisotropic diffusion parameter N at different temperatures. The comparison between the two samples shows that the molecular geometry of the liquid crystals play important role in determining the value of the order parameter. The entire smectic A phase in OBT is characteristic of slow tumbling region (TR > 10-9 sec) and the anisotropic parameter N shows an anomalous increase in this phase. This indicates that the slowly relaxing local structure (SRLS) mechanism plays important role in the slow tumbling region. In NPOB the incipient slow tumbling region is almost at the end of smectic A phase and the SRLS mechanism does not seem to play as important role as in OBT

ESR line shape study of two nematic liquid crystals

Electron spin-resonance (ESR) measurements of the spin-probe17β-hydroxy-4,4'-dimethyl spiro[5α-androstane-3,2-oxazolidine]-3'-yloxyl in the liquid crystals 4-n-Amylacetophenon O-(4-n-heptyl benzoyl)-oxime [AAHBO] and 4-n-Butoxyphenyl hexyl benzoate [BPHB] are reported in isotropic and nematic phases. On the basis of the temperature variation of ESR line width, an extra, solid to solid, phase transition is observed in BPHB. The theory of Polnaszek, Bruno and Freed (PBF) appropriate for anisotropic viscosity diffusion is used to analyze the ESR spectra and thereby to determine the values of the order parameter, the rotational diffusion tensor and the correlation time at different temperatures for the two liquid crystals. The analysis shows that the slowly relaxing local structure mechanisms (SRLS) is active in slow tumbling region specially in AAHBO

Onset of Nucleate Boiling and Critical Heat Flux with Boiling Water in Microchannels

This paper focuses on experimental determination of onset of nucleate boiling (ONB) and critical heat flux (CHF) at the microscales, and comparison of these with available correlations. The working fluid is deionised water and microchannel of four different hydraulic diameters: 65, 70, 107 and 125 m, have been tested. Effect of hydraulic diameter (65-125 m), mass flux (60-1410 kg/m2s) and heat flux (0-910 kW/m2) on ONB and CHF has been studied in detail. The heat flux for onset of nucleate boiling increases with hydraulic diameter and mass flux. The critical heat flux tends to increase with a decrease in hydraulic diameter and with increasing mass flux. The effect of surface roughness on CHF has also been tested to a limited extent; no clear change in the CHF value was observed upon changing the surface roughness by an order of magnitude. The empirical correlations tested in this study predict the experimental data to varying extent. These results may help better determine the lower and upper limits of heat flux while designing heat sink for electronic cooling

Onset of Nucleate Boiling and Critical Heat Flux with Boiling Water in Microchannels

This paper focuses on experimental determination of onset of nucleate boiling\ud (ONB) and critical heat flux (CHF) at the microscales, and comparison of these with\ud available correlations. The working fluid is deionised water and microchannel of four\ud different hydraulic diameters: 65, 70, 107 and 125 m, have been tested. Effect of\ud hydraulic diameter (65-125 m), mass flux (60-1410 kg/m2s) and heat flux (0-910\ud kW/m2) on ONB and CHF has been studied in detail. The heat flux for onset of nucleate\ud boiling increases with hydraulic diameter and mass flux. The critical heat flux tends to\ud increase with a decrease in hydraulic diameter and with increasing mass flux. The effect\ud of surface roughness on CHF has also been tested to a limited extent; no clear change in\ud the CHF value was observed upon changing the surface roughness by an order of\ud magnitude. The empirical correlations tested in this study predict the experimental data to\ud varying extent. These results may help better determine the lower and upper limits of heat\ud flux while designing heat sink for electronic cooling

Evaluation of nephroprotective effect of Bryonia lacinosa on streptozotocin induced diabetic nephropathy in rats

Background: Ayurvedic literature indicated use of Bryonia laciniosa (BL) for metabolic abnormalities. However only one study evaluated Bryonia laciniosa seed ethanolic extract in streptozotocin-induced diabetes in rats and was found to have anti-hyperglycemic and anti-hyperlipidemic effects. The authors looked at the renal function test in addition and found that it prevents deterioration of renal function in rats. Hence it was interesting to find if Bryonia laciniosa had any protective action in streptozotocin induced diabetic nephropathy in rats.Methods: Streptozotocin induced diabetic nephropathy model in wistar rats was standardised in phase 1. In phase 2 animals were divided into 4 groups and diabetic nephropathy was induce with STZ. Vehicle Control group animals received CMC 0.5%, Positive control group received enalapril 5 mg/kg, Test group 1 received ethanolic extract of Bryonia laciniosa (EEBL) 250 mg/kg and Test group 2 received (EEBL) 500 mg/kg from 3rd day onwards till 6 weeks. Renal function, morphology and histopthological changes were evaluated.Results: There was a significant reduction (p <0.001) in the serum creatinine and BUN in both low and high dose EEBL groups. High dose of EEBL lowered raised MDA values significantly (p<0.001) and raised the GSH values (p<0.001). On histopathology, the high dose EEBL reversed nephropathic changes which were equivalent to enalapril.Conclusions: Bryonia lacinosa in high doses 500 mg/kg has potential to reverse diabetic nephropathic changes induced in wistar rats

Intense blue-emitting Ca5Al8O14 : Eu phosphor for mercury free lamp

The calcium aluminates doped with Eu ions, Ca5Al8O14 : Eu, phosphors are prepared by the combustion method. The formation of crystalline aluminates was confirmed by X-ray diffraction pattern. The prepared phosphors were characterized by SEM, TGA, DTA, particle size analyzer and Photoluminescence (PL) techniques. From the UV-excited luminescence spectra it was found that the Eu ions acts as a luminescent centre with luminescence at the blue (λmax = 470 nm) region due to 4f 65d1 → 4f 7 transition. The excitation spectra show the broad band at 355 nm wavelength (λem = 470 nm). The excitation 355 nm is a mercury free excitation and therefore Ca5Al8O14 : Eu may be useful for the solid state lighting phosphor in lamp industry.Intense blue-emitting Ca5Al8O14 : Eu phosphor for mercury free lamp Abhay D Deshmukh1*, S J Dhoble1, S V Godbole2, M K Bhide2 and D R Peshwe3 1Kamla Nehru College, Sakkardara Square, Nagpur-440 009, Maharashtra, India 2Spectroscopy Section, Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai-400 085, India 3Department of Metallurgical and Materials Engineering, VNIT, Nagpur-440 011, Maharashtra, India E-mail : [email protected] Nehru College, Sakkardara Square, Nagpur-440 009, Maharashtra, India 2Spectroscopy Section, Radiochemistry Division, Bhabha Atomic Research Centre, Mumbai-400 085, India 3Department of Metallurgical and Materials Engineering, VNIT, Nagpur-440 011, Maharashtra, Indi

Comparison of Wavelet Transform and Fourier Transform based methods of Phasor Estimation for Numerical Relaying

Abstract-Estimatio

Behavioral and neuroanatomical consequences of cell-type specific loss of dopamine D2 receptors in the mouse cerebral cortex

Developmental dysregulation of dopamine D2 receptors (D2Rs) alters neuronal migration, differentiation, and behavior and contributes to the psychopathology of neurological and psychiatric disorders. The current study is aimed at identifying how cell-specific loss of D2Rs in the cerebral cortex may impact neurobehavioral and cellular development, in order to better understand the roles of this receptor in cortical circuit formation and brain disorders. We deleted D2R from developing cortical GABAergic interneurons (Nkx2.1-Cre) or from developing telencephalic glutamatergic neurons (Emx1-Cre). Conditional knockouts (cKO) from both lines, Drd2fl/fl, Nkx2.1-Cre+ (referred to as GABA-D2R-cKO mice) or Drd2fl/fl, Emx1-Cre+ (referred to as Glu-D2R-cKO mice), exhibited no differences in simple tests of anxiety-related or depression-related behaviors, or spatial or nonspatial working memory. Both GABA-D2R-cKO and Glu-D2R-cKO mice also had normal basal locomotor activity, but GABA-D2R-cKO mice expressed blunted locomotor responses to the psychotomimetic drug MK-801. GABA-D2R-cKO mice exhibited improved motor coordination on a rotarod whereas Glu-D2R-cKO mice were normal. GABA-D2R-cKO mice also exhibited spatial learning deficits without changes in reversal learning on a Barnes maze. At the cellular level, we observed an increase in PV+ cells in the frontal cortex of GABA-D2R-cKO mice and no noticeable changes in Glu-D2R-cKO mice. These data point toward unique and distinct roles for D2Rs within excitatory and inhibitory neurons in the regulation of behavior and interneuron development, and suggest that location-biased D2R pharmacology may be clinically advantageous to achieve higher efficacy and help avoid unwanted effects.Fil: Lee, Gloria S.. Florida State University; Estados UnidosFil: Graham, Devon L.. Florida State University; Estados UnidosFil: Noble, Brenda L.. Florida State University; Estados UnidosFil: Trammell, Taylor S.. Florida State University; Estados UnidosFil: McCarthy, Deirdre M.. Florida State University; Estados UnidosFil: Anderson, Lisa R.. Florida State University; Estados UnidosFil: Rubinstein, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Bhide, Pradeep G.. Florida State University; Estados UnidosFil: Stanwood, Gregg D.. Florida State University; Estados Unido

Understanding the Benefit of Magnetic Resonance-guided Adaptive Radiotherapy in Rectal Cancer Patients: a Single-centre Study.

AIMS: Neoadjuvant chemoradiotherapy followed by surgery is the mainstay of treatment for patients with rectal cancer. Standard clinical target volume (CTV) to planning target volume (PTV) margins of 10 mm are used to accommodate inter- and intrafraction motion of target. Treating on magnetic resonance-integrated linear accelerators (MR-linacs) allows for online manual recontouring and adaptation (MRgART) enabling the reduction of PTV margins. The aim of this study was to investigate motion of the primary CTV (CTVA; gross tumour volume and macroscopic nodes with 10 mm expansion to cover microscopic disease) in order to develop a simultaneous integrated boost protocol for use on MR-linacs. MATERIALS AND METHODS: Patients suitable for neoadjuvant chemoradiotherapy were recruited for treatment on MR-linac using a two-phase technique; only the five phase 1 fractions on MR-linac were used for analysis. Intrafraction motion of CTVA was measured between pre-treatment and post-treatment MRI scans. In MRgART, isotropically expanded pre-treatment PTV margins from 1 to 10 mm were rigidly propagated to post-treatment MRI to determine overlap with 95% of CTVA. The PTV margin was considered acceptable if overlap was >95% in 90% of fractions. To understand the benefit of MRgART, the same methodology was repeated using a reference computed tomography planning scan for pre-treatment imaging. RESULTS: In total, nine patients were recruited between January 2018 and December 2020 with T3a-T4, N0-N2, M0 disease. Forty-five fractions were analysed in total. The median motion across all planes was 0 mm, demonstrating minimal intrafraction motion. A PTV margin of 3 and 5mm was found to be acceptable in 96 and 98% of fractions, respectively. When comparing to the computed tomography reference scan, the analysis found that PTV margins to 5 and 10 mm only acceptably covered 51 and 76% of fractions, respectively. CONCLUSION: PTV margins can be reduced to 3-5 mm in MRgART for rectal cancer treatment on MR-linac within an simultaneous integrated boost protocol

Carbon Nanotubes by a CVD Method. Part I: Synthesis and Characterization of the (Mg, Fe)O Catalysts

The controlled synthesis of carbon nanotubes by chemical vapor deposition requires tailored and wellcharacterized catalyst materials. We attempted to synthesize Mg1-xFexO oxide solid solutions by the combustion route, with the aim of performing a detailed investigation of the influence of the synthesis conditions (nitrate/urea ratio and the iron content) on the valency and distribution of the iron ions and phases. Notably, characterization of the catalyst materials is performed using 57Fe Mo¨ssbauer spectroscopy, X-ray diffraction, and electron microscopy. Several iron species are detected including Fe2+ ions substituting for Mg2+ in the MgO lattice, Fe3+ ions dispersed in the octahedral sites of MgO, different clusters of Fe3+ ions, and MgFe2O4-like nanoparticles. The dispersion of these species and the microstructure of the oxides are discussed. Powders markedly different from one another that may serve as model systems for further study are identified. The formation of carbon nanotubes upon reduction in a H2/CH4 gas atmosphere of the selected powders is reported in a companion paper