Evaluation of the Efficacy of Dexamethasone Versus Magnesium Sulfate in Prevention of Postspinal Shivering: A Prospective, Randomized, Double-Blind Study

Background: Postspinal shivering represents one of the distressing complications of regional anesthesia. This study evaluated the efficacy of dexamethasone and magnesium sulfate to prevent postspinal shivering (PSAS) in lower abdominal and lower limb surgeries. Materials and Methods: Hundred forty-seven patients undergoing elective abdominal and lower limb surgery under spinal anesthesia received either 100 mL isotonic saline (group C), 8 mg in 100 mL isotonic saline (group D), or magnesium sulfate 30 mg/kg in 100 mL isotonic saline (Group M). Results: The incidence of clinically significant shivering was highly significantly less in group D and group M compared to group C (p=0.001), however, there was no statistically significant difference between group D and group M (p=0.052). The onset of shivering was significantly lower in the C group compared to the D and M groups with statistically significant differences between the D and M groups (p=0.001). Conclusion: Dexamethasone and magnesium sulfate were effective in the prevention of PSAS in patients undergoing lower abdominal and lower limb surgeries under spinal anesthesia. However, magnesium sulfate is better than dexamethasone as it is accompanied by less incidence of shivering, and its sedative effect decreases the stress of the surgery

Lie group analysis for the effects of chemical reaction on MHD stagnation-point flow of heat and mass transfer towards a heated porous stretching sheet with suction or injection

An analysis is carried out to study two dimensional stagnation-point flow of heat and mass transfer of an incompressible, electrically conducting fluid towards a heated porous stretching sheet embedded in a porous medium in the presence of chemical reaction, heat generation/absorption and suction or injection effects. A scaling group of transformations is applied to the governing equations. After finding three absolute invariants a third order ordinary differential equation corresponding to the momentum equation and two second order ordinary differential equation corresponding to energy and diffusion equations are derived. Furthermore the similarity equations are solved numerically by using shooting technique with fourth-order Runge–Kutta integration scheme. A comparison with known results is excellent. The phenomenon of stagnation-point flow towards a heated porous stretching sheet in the presence of chemical reaction, suction or injection with heat generation/absorption effects play an important role on MHD heat and mass transfer boundary layer. The results thus obtained are presented graphically and discussed

Similarity Solutions for a Steady MHD Falkner-Skan Flow and Heat Transfer over a Wedge Considering the Effects of Variable Viscosity and Thermal Conductivity

An analysis is carried out to study the Falkner–Skan flow and heat transfer of an incompressible, electrically conducting fluid over a wedge in the presence of variable viscosity and thermal conductivity effects. The similarity solutions are obtained using scaling group of transformations. Furthermore the similarity equations are solved numerically by employing Kellr-Box method. Numerical results of the local skin friction coefficient and the local Nusselt number as well as the velocity and the temperature profiles are presented for different physical parameters

Data mining: a tool for detecting cyclical disturbances in supply networks.

Disturbances in supply chains may be either exogenous or endogenous. The ability automatically to detect, diagnose, and distinguish between the causes of disturbances is of prime importance to decision makers in order to avoid uncertainty. The spectral principal component analysis (SPCA) technique has been utilized to distinguish between real and rogue disturbances in a steel supply network. The data set used was collected from four different business units in the network and consists of 43 variables; each is described by 72 data points. The present paper will utilize the same data set to test an alternative approach to SPCA in detecting the disturbances. The new approach employs statistical data pre-processing, clustering, and classification learning techniques to analyse the supply network data. In particular, the incremental k-means clustering and the RULES-6 classification rule-learning algorithms, developed by the present authors’ team, have been applied to identify important patterns in the data set. Results show that the proposed approach has the capability automatically to detect and characterize network-wide cyclical disturbances and generate hypotheses about their root cause

Sol–Gel Synthesis of Iron-Doped Sepiolite as a Novel Humidity-Sensing Material

Nowadays, humidity sensors are attracting a great deal of attention, and there are many studies focusing on enhancing their performances. Nevertheless, their fabrication through facile methods at reasonable cost is a significant factor. In this article, a new magnesium silicate nanopowder was successfully synthesized using a simple and low-cost sol–gel method. Subsequently, modified sepiolite was achieved by the substitution of iron ions in the synthesized nanopowders. The specimens were then characterized by X-ray diffraction, field emission–scanning electron microscopy, X-ray photoelectron spectroscopy, thermogravimetric–differential thermal analysis, infrared spectroscopy, and nitrogen adsorption. Furthermore, humidity sensors were manufactured by screen printing the prepared powders on alumina substrates with interdigitated Pt electrodes. The results showed that the fabricated sensors with modified sepiolite exhibited interesting characteristics for humidity detection

A New Generalized Family of Distributions for Lifetime Data

A new class of continuous distributions called the generalized Burr X-G family is introduced. Some special models of the new family are provided. Some of its mathematical properties including explicit expressions for the quantile and generating functions, ordinary and incomplete moments, order statistics and Rényi entropy are derived. The maximum likelihood is used for estimating the model parameters. The flexibility of the generated family is illustrated by means of two applications to real data sets

Effect of Hydrogen on Pristine Amorphous V2O5 Thin Film

Sequentially deposited layer by layer up to five vanadium oxide film is deposited on glass and silica substrates at 300 k by vacuum thermal evaporation technique. The deposited samples subjected to reduction process in the preparation situe by hydrogen gas at 473k for 10 minutes and 573 k for 10, 20 minutes. The XRD investigation of the samples demonstrates that the pristine sample is amorphous while those reduced are crystalline. The existed phases in virgin samples are educated by Raman spectroscopy which indicates the single V2O5 phase. The different phases in the reduced sample are identified by analyzing their XRD patterns. The electrical resistance of the reduced samples is measured as a function of temperature during heating and cooling cycles. The transition temperature from semiconducting to metal state is defined by the derivative of dR/d

Kinetic Simulation of He radio frequency capacitive coupled plasma

Radiofrequency capacitively coupled plasma is studied theoretically using a Particle-in-Cell code. For He discharge, the time-averaged sheaths are in the range of few centimeters. The sheath potential, ion, and electron energy and angular distributions, discharge current, and dissipated power depend on the driven potentials and frequencies. Increasing the amplitude of the high radio frequencies increases the bulk density and the sheath potential and, consequently, increases the plasma processing rate. Increasing the intermediate radio frequency amplitude allows a wider sheath with a broad ion energy distribution and a narrower ion angular distribution. Changing the amplitude and the phase shift between driven frequencies provide different energies and angular distribution allowing performing various processes. The interplay between the sheath and bulk dynamics in the intermediate radiofrequency regime and the high-frequency regime may excite harmonics in the discharge current