807 research outputs found

    N,N′-(1,4-Phenyl­ene)bis­(2-bromo-2-methyl­propanamide)

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    The mol­ecular structure of the title compound, C14H18Br2N2O2, has one half-mol­ecule in the asymmetric unit. The mol­ecule has a crystallographic inversion centre in the middle of the benzene ring. The C—C—N—C torsion angle between the benzene ring and the bromo­amide group is 149.2 (7)°. The crystal is stabilized by a strong inter­molecular N—H⋯O bond and weak C—H⋯O inter­actions. These contacts give rise to a three-dimensional network

    Hot Corrosion of Weldments

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    Hot corrosion of the weldment is the result of the reaction between oxidation and sulfidation, which affects welded joints exposed to combustion gases containing sulfate coal ash at high temperature. It is also demonstrated that welding processes, weld consumables, temperature of exposure, and mixture of salt environment are important factors in hot corrosion of the weldment

    Early Cenozoic rapid flight enigma of the Indian subcontinent resolved: roles of topographic top loading and subcrustal erosion

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    Intrinsic magmatic processes are considered as critical operators of plate movements. Here we demonstrate the role of extrinsic processes consequent to intrinsic processes as a catalyst for anomalous rapid plate movement. The rapid and accelerated flight of the Indian subcontinent since Deccan volcanism until its collision with Eurasia remains as one of the geological conundrums. Data on seismic tomography, peninsular geomorphology and inferences on continuum of subcrustal structures are utilized to address this enigma. We propose geomorphic isostasy as the mechanism that has driven this fastest drift ever recorded in geological history. It was initiated by sudden instability after the Deccan volcanism and resultant extensive accumulation of lava pile over continental lithosphere of northern India, northern-eastern tilt due to crustal thickness heterogeneity and subcrustal thermal stratification. The drift was sustained by Carlsberg and Central Indian ridge-push until collision and sediment top loading at northeast thenceforth. These inferences and geomorphic isostasy as a catalytic mechanism necessitate variability of drift rates as integral inputs for any continental scale modeling.Muthuvairavasamy Ramkumar, David Menier, Manoj Mathew, M. Santosh, Numair A. Siddiqu

    First simultaneous lidar observations of sodium layers and VHF radar observations of E-region field-aligned irregularities at the low-latitude station Gadanki

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    Simultaneous observations of atmospheric sodium (Na) made by a resonance lidar and E-region field-alignedirregularities (FAI) made by the Indian MST radar, both located at Gadanki (13.5°N, 79.2°E) and horizontal winds acquired by a SKiYMET meteor radar at Trivandrum (8.5°N, 77°E) are used to investigate the relationship among sodium layer, FAI and neutral winds in the mesosphere and lower thermosphere region. The altitudes and descent rates of higher altitude (~ 95 km) Na layer and FAI agree quite well. The descending structures of the higher altitude Na layer and FAI are found to be closely related to the diurnal tidal phase structure in zonal winds observed over Trivandrum. At lower altitudes, the descent rate of FAI is larger than that of Na layer and zonal tidal phase. These observations support the hypothesis that the metallic ion layers are formed by the zonal wind shear associated with tidal winds and subsequently get neutralized to manifest in the form of descending Na layers. The descending FAI echoing layers are manifestation of the instabilities setting in on the ionization layer. In the present observations, the altitudes of occurrence of Na layer and FAI echoes being low, we surmise that it is quite possible that the FAI echoes are due to the descent of already formed irregularities at higher altitudes

    Vertical propagation characteristics and seasonal variability of tidal wind oscillations in the MLT region over Trivandrum (8.5° N, 77° E): first results from SKiYMET Meteor Radar

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    Tidal activity in the Mesospheric Lower Thermosphere (MLT) region over Trivandrum (8.5° N, 77° E) is investigated using the observations from newly installed SKiYMET Meteor Radar. The seasonal variability and vertical propagation characteristics of atmospheric tides in the MLT region are addressed in the present communication. The observations revealed that the diurnal tide is more prominent than the semi/terdiurnal components over this latitude. It is also observed that the amplitudes of meridional components are stronger than that of zonal ones. The amplitude and phase structure shows the vertical propagation of diurnal tides with vertical wavelength of ~25 km. However, the vertical wavelength of the semidiurnal tide showed considerable variations. The vertical propagation characteristics of the terdiurnal tide showed some indications of their generating mechanisms. The observed features of tidal components are compared with Global Scale Wave Model (GSWM02) values and they showed a similar amplitude and phase structure for diurnal tides. Month-to-month variations in the tidal amplitudes have shown significant seasonal variation. The observed seasonal variation is discussed in light of the variation in tidal forcing and dissipation

    2-Oxo-4-trifluoro­meth­yl-2H-chromen-7-yl 2-bromo-2-methyl­propano­ate

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    In the title compound, C14H10BrF3O4, the coumarin ring system is almost plannar (r.m.s. deviation = 0.025 Å) and a short C—H⋯F contact occurs. The propano­ate fragment is orientated almost perpendicular to the ring [dihedral angle = 71.80 (12)°]. In the crystal, mol­ecules are linked by C—H⋯O hydrogen bonds, generating [100] chains

    Gamma Radiation influence on Growth, Biochemical and Yield Characters of Cajanus cajan (L.) Millsp.

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    The present investigation deals with the effect of gamma radiation on growth, Biochemical and yield traits of Pigeon pea. The seeds of Pigeon pea Var.CO-7 were treated with different doses of gamma rays like 15, 20 and 25KR. The treated seeds were sown in field along with control to raise M1 generation and the radiation effects was noted from seed germination percentage, seedling survival (%), seedling height on 30th days, Days to first flower, plant height, (at maturity), number of branches, number  of leaves, number of cluster, pollen viability (%), number of pods, seed yield, hundred seed weight (g), fresh and dry weight (g), Seed viability (%) and seed protein content (%). The results indicates that the growth, biochemical and yield parameters were gradually decreased when compare to control and the highest reduction was noted at higher doses of gamma radiation treatments. The pollen and seed viability (%) analysis were also reveled that gradually reduction in lower to higher doses of gamma rays treatments

    Maternal Vitamin D, Folate, and Polyunsaturated Fatty Acid Status and Bacterial Vaginosis during Pregnancy

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    Objective. To investigate associations among serum 25-hydroxy-vitamin D (25-OH-D), folate, omega-6/omega-3 fatty acid ratio and bacterial vaginosis (BV) during pregnancy. Methods. Biospecimens and data were derived from a random sample (N = 160) of women from the Nashville Birth Cohort. We compared mean plasma nutrient concentrations for women with and without BV during pregnancy (based on Nugent score ≥7) and assessed the odds of BV for those with 25-OH-D <12 ng/mL, folate <5 ug/L, and omega-6/omega-3 ratio >15. Results. The mean plasma 25-OH-D was significantly lower among women with BV during pregnancy (18.00±8.14 ng/mL versus 24.34±11.97 ng/mL, P = 0.044). The adjusted odds of BV were significantly increased among pregnant women with 25-OH-D <12 ng/mL (aOR 5.11, 95% CI: 1.19–21.97) and folate <5 ug/L (aOR 7.06, 95% CI: 1.07–54.05). Conclusion. Vitamin D and folate deficiencies were strongly associated with BV (Nugent score ≥7) during pregnancy

    Network Management System for (FUTON-like) Radio-over- Fiber Infrastructure

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    EU-Project FUTON Radio-over-Fiber (RoF) infrastructure proposes high transmission rates at small antenna costs, implying competitive CAPEX for next generation networks. But to be cost-efficient, it needs to employ new network architectures and intelligent technology solutions for decreasing network operational costs. The RoF Network Manager manages the network equipment on the optical front haul between the Central Unit (CU) and all Remote Antenna Units (RAU)s connected by it, as well as the communication links, while enabling end-to-end service problem resolution and service quality management by the FUTON Middleware. Although a significant amount of prior research work can be found in the literature related to RoF, there is still significant lack of technologies concerning RoF networks management. RoF Manager and its sub-systems target to fill such gap, proposing a novel concept in the form of Channel Forwarding Table (CFT). RoF Manager follows an autonomous and generic network management framework, designed to be scalable in terms of adding new network elements (NEs). It targets multitechnology, multi-service and multi-vendor NEs in the network using Simple Network Management Protocol (SNMP). It can also provide alternative paths in case of failure. This work puts forward a new paradigm towards RoF management solution managing network performance, network faults, network security and configurations for convergent networks

    2-Bromo-2-methyl-N-(4-methyl-2-oxo-2H-chromen-7-yl)propanamide

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    In the title compound C14H14BrNO3, the coumarin ring system is almost planar (r.m.s. deviation = 0.008 Å) and an intra­molecular C—H⋯O inter­action generates an S(6) ring. In the crystal, mol­ecules are linked by N—H⋯O hydrogen bonds, with the C=O unit of the coumarin ring system acting as the acceptor group, generating [010] C(8) chains. The chain connectivity is reinforced by two C—H⋯O inter­actions
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