Electrodeposition of copper on copper single crystal (100) face in presence of chloride ions

Observations of copper electrodeposits on to the (100) plane of copper was made from highly purified solutions of copper sulphate containing known concentration of hydrochloric acid from 10−10 to 10−1 m/L. In pure solutions at current densities of 5 and 10 mA/cm.2 layers and pyramids were noticed. In the presence of hydrochloric acid of concentration 10−9 to 10−5 m/L there is a gradual decrease of distance between successive steps. At 10−4 m/L of HCl there was the breaking of layers giving rise to ridge type of growth. With the increase of concentration to 3·5×10−3 m/L pyramids appear again. On increasing the concentration of HCl to 10−2 m/L there was the formation of triangular pyramids of cuprous chloride and on still increasing the concentration, polycrystalline type of deposit was noticed. The transition from layer to ridge, ridge to pyramids and to polycrystalline deposit occurs at all c.d. studied but the critical concentration of HCl needed for the transition depends upon the current density. Communicated by Prof. M. Santappa,f.a.sc

Growth of Cu2Cl2 and Cu2Br2 on single crystal faces and polycrystalline copper during dissolution in CuSO4 + H2SO4

Cu2Cl2 and Cu2Br2 precipitate and crystallise in the form of triangular pyramids and dendrites when Cu is immersed in aerated, acid CuSO4 solution containing HC1 or HBr. The critical concentration of HC1 or HBr for this precipitation depends on the surface of the copper: Poly-crystalline < (110) < (100) < (111). In the deaerated solution there is no precipitation of Cu2Cl or Cu2Br2 even at a high concentration of HC1 or HBr when only preferential etching occurs

The Radiation Transfer at a Layer of Magnetized Plasma With Random Irregularities

The problem of radio wave reflection from an optically thick plane monotonous layer of magnetized plasma is considered at present work. The plasma electron density irregularities are described by spatial spectrum of an arbitrary form. The small-angle scattering approximation in the invariant ray coordinates is suggested for analytical investigation of the radiation transfer equation. The approximated solution describing spatial-and-angular distribution of radiation reflected from a plasma layer has been obtained. The obtained solution has been investigated numerically for the case of the ionospheric radio wave propagation. Two effects are the consequence of multiple scattering: change of the reflected signal intensity and anomalous refraction.Comment: 22 pages, 4 figure

Quantitative sensory testing in children with sickle cell disease: additional insights and future possibilities.

Quantitative sensory testing (QST) is used in a variety of pain disorders to characterize pain and predict prognosis and response to specific therapies. In this study, we aimed to confirm results in the literature documenting altered QST thresholds in sickle cell disease (SCD) and assess the test-retest reliability of results over time. Fifty-seven SCD and 60 control subjects aged 8-20 years underwent heat and cold detection and pain threshold testing using a Medoc TSAII. Participants were tested at baseline and 3 months; SCD subjects were additionally tested at 6 months. An important facet of our study was the development and use of a novel QST modelling approach, allowing us to model all data together across modalities. We have not demonstrated significant differences in thermal thresholds between subjects with SCD and controls. Thermal thresholds were consistent over a 3- to 6-month period. Subjects on whom hydroxycarbamide (HC) was initiated shortly before or after baseline testing (new HC users) exhibited progressive decreases in thermal sensitivity from baseline to 6 months, suggesting that thermal testing may be sensitive to effective therapy to prevent vasoocclusive pain. These findings inform the use of QST as an endpoint in the evaluation of preventative pain therapies

Complex Dynamics and Synchronization of Delayed-Feedback Nonlinear Oscillators

We describe a flexible and modular delayed-feedback nonlinear oscillator that is capable of generating a wide range of dynamical behaviours, from periodic oscillations to high-dimensional chaos. The oscillator uses electrooptic modulation and fibre-optic transmission, with feedback and filtering implemented through real-time digital-signal processing. We consider two such oscillators that are coupled to one another, and we identify the conditions under which they will synchronize. By examining the rates of divergence or convergence between two coupled oscillators, we quantify the maximum Lyapunov exponents or transverse Lyapunov exponents of the system, and we present an experimental method to determine these rates that does not require a mathematical model of the system. Finally, we demonstrate a new adaptive control method that keeps two oscillators synchronized even when the coupling between them is changing unpredictably.Comment: 24 pages, 13 figures. To appear in Phil. Trans. R. Soc. A (special theme issue to accompany 2009 International Workshop on Delayed Complex Systems

Levels and Correlates of Non-Adherence to WHO Recommended Inter-Birth Intervals in Rufiji, Tanzania.

Poorly spaced pregnancies have been documented worldwide to result in adverse maternal and child health outcomes. The World Health Organization (WHO) recommends a minimum inter-birth interval of 33 months between two consecutive live births in order to reduce the risk of adverse maternal and child health outcomes. However, birth spacing practices in many developing countries, including Tanzania, remain scantly addressed. METHODS: Longitudinal data collected in the Rufiji Health and Demographic Surveillance System (HDSS) from January 1999 to December 2010 were analyzed to investigate birth spacing practices among women of childbearing age. The outcome variable, non-adherence to the minimum inter-birth interval, constituted all inter-birth intervals <33 months long. Inter-birth intervals >=33 months long were considered to be adherent to the recommendation. Chi-Square was used as a test of association between non-adherence and each of the explanatory variables. Factors affecting non-adherence were identified using a multilevel logistic model. Data analysis was conducted using STATA (11) statistical software. RESULTS: A total of 15,373 inter-birth intervals were recorded from 8,980 women aged 15--49 years in Rufiji district over the follow-up period of 11 years. The median inter-birth interval was 33.4 months. Of the 15,373 inter-birth intervals, 48.4% were below the WHO recommended minimum length of 33 months between two live births. Non-adherence was associated with younger maternal age, low maternal education, multiple births of the preceding pregnancy, non-health facility delivery of the preceding birth, being an in-migrant resident, multi-parity and being married. CONCLUSION: Generally, one in every two inter-birth intervals among 15--49 year-old women in Rufiji district is poorly spaced, with significant variations by socio-demographic and behavioral characteristics of mothers and newborns. Maternal, newborn and child health services should be improved with a special emphasis on community- and health facility-based optimum birth spacing education in order to enhance health outcomes of mothers and their babies, especially in rural settings

Seat of the Joshi Effect in A.C. Silent Discharges

Some experiments on the positive and negative Joshi effects in 'sleeve' discharge tubes containing iodine vapour and hydrogen gas have been performed to Study the effect of illuminating the different parts of each discharge tube successively by a narrow beam of strong light. The results of these experiments are given in the piper with an account of the experimental arrangements. The results have shown that the Joshi effect (positive and negative) is associated predominantly with the regions of the electrodes. The role of the discharge column of the lube in the production of the Joshi effect, if any, is, however, regarded as uncertain. The effect of stray light affecting the electrodes after being scattered from the illuminated part of the discharge tube is considered in discussing the experimental results of Agashe

Performance Analysis of Reactive Routing Protocols AODV, DYMO, DSR, LAR in MANETs

MANETs are one the cutting-edgeevolving wireless technologies. The routing in mobile ad hoc networksplays a vital role and has been researchedwide-range in last decade. The routing protocols are classified as proactive,reactive and hybrid. Reactive routing protocols are considered for its advantages compared to others. In this paper, reactive routing protocols, Ad Hoc On-demand Distance Vector (AODV), Dynamic MANET On-demand (DYMO) protocol, Dynamic Source Routing protocol (DSR), Location Aided Routing protocol have been selected to analyze the performance and compare the routing protocols by varying Network size and Mobility speed to various levels. The performance metrics analyzed were Average Throughput, Average End-to-End Delay, Average Jitter, Energy Consumed in Transmit Mode, Energy Consumed in Receive Mode. The simulations were carried on Exata 5.4 simulator. The analysis of the routing protocols for the configuration setting is presented at the conclusion