2,595 research outputs found
Complexes of Some Group(IV) Metal Halides with 5-Aminoindazole
The synthesis and characterisation of Sn(IV) halides, Ge(IV),
Ti(IV) and Zr(IV) chloride complexes of the type MX4 : Li_ 2 with
5-aminoindazole has been made. The possible structure of these
complexes has been proposed on the basis of elemental analysis
and infrared spectroscopy. The IR spectra suggest unidentate
behaviour of the ligand involving pyrrole nitrogen in all the cases
except the tin(IV) bromide complex, where the ligand exhibits its
bidentate nature, involving the pyridyl nitrogen. An octahedral
geometry has been proposed for all the complexes. In the case
of MX4 :\u27L type complexes, except for SnBr4 : L, an octahedral
halogen bridged structure has been proposed
Complexes of Some Group(IV) Metal Halides with 5-Aminoindazole
The synthesis and characterisation of Sn(IV) halides, Ge(IV),
Ti(IV) and Zr(IV) chloride complexes of the type MX4 : Li_ 2 with
5-aminoindazole has been made. The possible structure of these
complexes has been proposed on the basis of elemental analysis
and infrared spectroscopy. The IR spectra suggest unidentate
behaviour of the ligand involving pyrrole nitrogen in all the cases
except the tin(IV) bromide complex, where the ligand exhibits its
bidentate nature, involving the pyridyl nitrogen. An octahedral
geometry has been proposed for all the complexes. In the case
of MX4 :\u27L type complexes, except for SnBr4 : L, an octahedral
halogen bridged structure has been proposed
Numerical Simulation of Thermal Stresses in Prismatic Concrete Beams Reinforced with FRP Bars under Low Temperatures
The thermal properties of fiber reinforced polymer (FRP) bars particularly in the transverse direction are higher than those of hardened concrete and steel bars. The difference in transverse thermal characteristics between FRP bar and concrete generates radial tensile stresses within concrete at the interface of FRP bars/concrete under low temperatures. These thermal stresses may cause circumferential cracks in concrete at the interface and eventually the reduction of the bond that can affect significantly the serviceability of reinforced concrete structures. This paper presents a nonlinear numerical simulation of thermal stresses in prismatic concrete beams reinforced with glass FRP (GFRP) bars submitted to low temperatures when the confining action of concrete is asymmetric. The non linear numerical analysis shows that the first circumferential cracks start to develop within concrete at FRP bar/concrete interface at a temperature decrease DTcr varied between -30°C and -25°C for prismatic concrete beams reinforced with GFRP bars having a ratio of concrete cover thickness to FRP bar diameter (c/db) varied from 1.0 to 3.2. Furthermore, the depths of circumferential cracks propagated from the interface through the concrete cover increase with the decrease of the thermal load DT (from -25 °C to -50 °C). These depths did not reach the outer surface of the concrete cover under low temperatures up to -50 °C. Also, the radial tensile stress at FRP bar/concrete interface increases with the increase in the ratio c/db. The cracking thermal loads and thermal stresses predicted from nonlinear finite element model are compared to those evaluated with analytical models. Comparisons between numerical and analytical results in terms of cracking thermal loads and thermal stresses are presented
Transition Metal Complexes of a-Naphthylamine Dithiocarbamate
a-Naphthylamine dithiocarbamate and its complexes with
Co(II), Ni(U), Cu(II), Ru(III) , Rh(III), Pd(II), Pt(IV), Zn(II), Cd(II)
and Hg(II) have been prepared and characterized by chemical
analysis, IR - and reflectance spectral studies and magnetic
susceptibili ty measurements. In all these complexes the dithiocarbamato
moiety acts as a chelate. The Ni(II), Cu(II) and Pd(Il)
complexes have been found to be square planar while those of
Ru(III), Rh(III) and Pt(IV) were proposed to be octahedral in
nature. The Co(II) ion seems to have a tetrahedral geometry, unlike
the other known square planar dithiocarbamato complexes of
Co(II). No definite structure, however, could be proposed for Zn(II),
Cd(II) and Hg(II) on the basis of limited studies
NOMA Enhanced Backscatter Communication for Green IoT Networks
Backscatter communication has recently emerged as a promising technology to enable the passive sensing-based Internet-of-things (IoT) applications. In a backscatter communication network, uplink transmissions of multiple nodes are usually multiplexed in time- or frequency-domain to avoid collisions, yet it is desirable to improve the uplink capacity further. In this paper, we study a wireless-powered backscatter communication system, where the sensors use a hybrid channel access scheme by combining time division multiplexing access (TDMA) with power-domain non-orthogonal multiple access (PD-NOMA) to enhance the system performance in terms of outage probability and throughput. Our analysis shows that the proposed PD-NOMA increases both the spectrum efficiency and the throughput of the system
Electro-coagulation coupled Electro-floatation process: Feasible choice in Doxycycline removal from Pharmaceutical effluents
Article CC-BYInternational audienceElectrochemical treatment involving a coupled coagulation and floatation was performed in the removal of Doxycycline Hyclate (DCH) from aqueous solutions. All the experiments were carried out in an electrochemical reactor of 1.5 L which contained aluminium electrodes as cathode and anode. The removal of doxycycline hyclate (DCH) species by EC/EF was determined as a function of electrolysis time, pH, current intensity, flow rate and DCH concentration. From the observed results, it was corroborated that the DCH removal through the EC/EF process was excellent. The effective contribution from initial pH (7.03) and current intensity (5.39 mA cm-2) was very much remarkable and well apparent from flocs of good buoyancy. The removal of DCH was inversely proportional to spacing between electrodes (SBE) and circulating flow rate in the presence of the supporting NaCl electrolyte of 1 g L-1. It was also highly promoted by the addition of NaCl in comparison to NaNO3 and KCl to the electrolytic system. The compliance of four kinetic models was verified with DCH removal system. The free energy values from DKR model suggested the nature of bonding by chemical forces. Characterization by FTIR, SEM and XRD interpreted the assignments of various functional groups, surface morphology and crystalline incorporated amorphous nature, respectively of electro – generated flocs. The current efficiency and specific electrical energy consumption at optimized conditions of the EC/EF system were calculate
A rapid method for preparation of sarcolemma from frog skeletal muscle
A rapid method for the preparation of sarcolema from frog skeletal muscle has been described. The purified cell segments were transparent and devoid of contractile material. The Na+, K+ -ATPase and 5'-nucleotidase activities in sarcolemma purified by this method were comparable to those reported for sarcolemmal preparations purified by density gradient centrifugation. The preparation also possessed acid phosphatase, alkaline phosphatase and K+ -activated, ouabain-sensitive p-nitrophenyl phosphatase activities. The cholesterol to phospholipid ratio of the sarcolemma was 0.33, indicating its high purity; further, the preparation was free from mitochondria and contractile proteins
A study of frequency and pulses for stepper motor controller system by using programmable logic controller
The stepper motor movement process produced different frequency and pulses. This research explained about the frequency and pulses for the stepper motor movement by using Programmable Logic Controller (PLC) as research method. The study was done to find the suitable frequency and pulses for stepper motor movement by developing a prototype stepper motor controller system. The pulse frequency used did not affected the distance of moving load in the stepper motor operations. The increasing number of pulse frequency only will affect the time taken for the stepper motor to complete its operations. The result showed that number of pulse frequency at high operation was 5000 Hz. Pulse number reacted as a manipulated variable that affected both factor which is time taken of stepper motor operation and the distance of moving load
Why do families of sick newborns accept hospital care? a community-based cohort study in Karachi, Pakistan
Objective: Sick young infants are at high risk of mortality in developing countries, but families often decline hospital referral. Our objective was to identify the predictors of acceptance of referral for hospital care among families of severely ill newborns and infants Karachi, Pakistan. Study Design: A cohort of 541 newborns and infants referred from home by community health workers conducting household surveillance, and diagnosed with a serious illness at local community clinics between 1 January and 31 December 2007, was followed-up within 1 month of referral to the public hospital. Result: Only 24% of families accepted hospital referral. Major reasons for refusal were financial difficulties (67%) and father/elder denying permission (65%). Religious/cultural beliefs were cited by 20% of families. Referral acceptance was higher with recognition of severity of the illness by mother (odds ratio = 12.7, 95% confidence interval = 4.6 to 35.2), family\u27s ability to speak the dominant language at hospital (odds ratio = 2.0, 95% confidence interval = 1.3-3.1), presence of grunting in the infant (odds ratio = 3.3, 95% confidence interval = 1.2-9.0) and infant temperature Conclusion: Refusal of hospital referral for sick young infants is very common. Interventions that encourage appropriate care seeking, as well as community-based management of young infant illnesses when referral is not feasible are needed to improve neonatal survival in low-income countries
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