OPTIMIZATION OF CONVECTIVE LONGITUDINAL FINS OF TRAPEZOIDAL PROFILE

This paper deals with optimum design of convective longitudinal fins of a trapezoidal profile. The optimum dimensions, and the associated heat dissipation, and efficiency are obtained in terms of dimensionless parameters, h√A_p/k and h_e/h. They are presented in graphical forms in order to aid thermal designers     

Construction and performance characteristics of a metformin electrode based on the metformin phosphotungstate ion-associate

A new metformin (Mf) ion selective PVC membrane electrode based on the ion-associate of Mf with phosphotungstic acid was prepared. The electrode exhibited a mean calibration graph slope of 58 mV Mf concentration decade^?1, at 25°C, within the concentration range 2·0 × 10^?5?1·0 × 10^?2 M MfCl. The change of pH within the range 4·0–11·0 did not affect the electrode performance. The standard electrode potentials were determined at different temperatures and used to calculate the isothermal coefficient of the electrode (0.000352 V°C^?1). The electrode showed a very good selectivity for Mf with respect to a large number of inorganic and organic cations. The standard addition method and potentiometric titration were applied to determine Mf in pure solutions and in metformin-containing tablets.     

Stabilizing control for a class of uncertain interconnected systems

A linear decentralized control is constructed to stabilize a class of interconnected nonlinear uncertain systems with time-varying state-delay and in which the output measurement is noisy. The control action is based on output-feedback for matched uncertainties and takes the effect of coupling into account. With the knowledge of the uncertainty bounds, it is established that the developed stabilizing controller renders the closed-loop interconnected system “globally practically stable”     

Investigation of the filtration rate of silica in aluminum fluoride production from silicic acid

The effect of some influencing parameters such as temperature, initial concentration of flusilicic acid, rate of addition of Al(OH)₃ powder, agitation speed and aging time of slurry and their mixed effects on the filtration rate of silica precipitates have been investigated. Moreover, a suitable model is presented to describe the formation mechanism of aggregated silica precipitates which can well explain the effect of different factors on the filtration rate of the silica precipitates.     

Far infrared spectrum of CD3OH methanol from 40–220 CM−1

The Fourier transform far-infrared (FTFIR) spectrum of CD₃OH has been obtained from 40–220 cm^?1 at a resolution of 0.002 cm^?1, and partially analyzed. Numerousb-type branches have been assigned in the spectrum, ranging over torsional states fromn=0 to 3. The branches have been fitted toJ(J+1) power-series energy expansions in order to obtainJ-independent branch origins. These in turn have been fitted to the torsion-rotation Hamiltonian, and improved molecular constants have been obtained for the ground vibrational state.     

Total cavopulmonary anastomosis: selection criteria related to postoperative results

Cystitis cystica, a common urothelial pathology whose aetiology, morphology and clinical significance are poorly understood, affects the human urinary bladder and trigone in both sexes. We have studied the fine structure of urothelial cysts in 11 patients diagnosed cystoscopically as suffering from cystitis cystica. Several abnormal features were observed in the adjacent urothelium, including large intracellular vacuoles (4 patients), Brunn's nest (5), lymphocyte infiltration (10) and generally disorganised urothelial architecture (10). Squamous metaplasia was observed in one case. The wall of each cyst consisted of a 2-3 layered epithelium with either tall columnar or flattened cells lining the fluid-filled lumen. Both types of lining cell possessed short microvilli, while the columnar type also contained numerous membrane-bound, electron dense secretory granules in the apical cytoplasm. Rough endoplasmic reticulum, mitochondria and Golgi membranes were plentiful in the surface cells. Junctional complexes joined adjacent lining cells. The deeper cells contained relatively fewer organelles, while a basal lamina separated the cyst wall from the underlying connective tissue.     

Analysis of two loops for carrier recovery in CPM with index 1/2

An examination is made of the performance of a squaring loop and a fourth-power loop used for tracking the received carrier phase of binary continuous-phase modulated (CPM) signals with index 1/2. Noise-free analysis is performed first and a simple relationship between the phase error and the control voltage is obtained for each case, with the premodulation filter response as a parameter. Linearized analysis of the phase error variance is then conducted in the presence of additive white Gaussian noise. It is shown that the phase variance in both cases contains a self-noise component that sets a lower bound on the synchronizer's performance at very high signal-to-noise ratios. Numerical results are presented for a number of popular CPM signals. It is found that the squaring loop performs best with MSK (minimum shift keying), while the fourth-power loop performs best with duobinary MSK     

Isolation and characterization of a lectin with antifungal activity from Egyptian Pisum sativum seeds

A plant lectin isolated in its pure state from the Egyptian seeds of Pisum sativum (PSL) produced two bands in SDS–PAGE (5.53 and 19.3 kDa; i.e. α and β chain) but one peak by gel filtration chromatography on Sephadex G-100, corresponding to 50 kDa, i.e., a dimeric structure of two monomers, each consisting of one α and one β subunit. PSL is a glycoprotein bound with glucose (2 mol/mol of protein) and stabilized by 2 atoms of each of Ca²⁺ and Mn²⁺ per molecule of protein. It highly agglutinated human, rabbit and rat erythrocytes but weakly agglutinated chicken erythrocytes, while no agglutination occurred with sheep erythrocytes. Hemagglutination was markedly affected by acidic pH, but was heat stable below 60 °C for 30 min. Among the various tested sugars, PSL agglutination was most inhibited by mannose. PSL is rich in hydroxyl amino acids while totally lacking sulfur amino acids. PSL inhibited the growth of Aspergillus flavus, Trichoderma viride and Fusarium oxysporum.     

An "offshore-resistant" degree program

The new University of Guelph-Humber has created an innovative, combined university degree and college diploma program in computer science and communications technology. This venture between the university and the Humber Institute of Technology and advanced learning offers jointly an honors baccalaureate in computing science from Guelph and a diploma in wireless and telecommunications systems technology from Humber. The program, one of six joint programs between the two institutions, specializes in distributed and wireless computing.