Effects of castration on adrenergic, cholinergic and nonadrenergic, noncholinergic responses of isolated corpus cavernosum from rabbit

OBJECTIVE: To investigate the effects of castration and testosterone on the constricting effect of phenylephrine and endothelium-dependent and -independent relaxing effects of different agonists in the corpus cavernosum of male rabbits. MATERIALS AND METHODS: Twenty rabbits were castrated and 10 received testosterone replacement for 1 month after castration; 10 further rabbits underwent a sham operation and acted as controls. One month after operation the rabbits were killed and their penises excised. Strips of corpus cavernosum were used for isometric tension measurements in organ chambers; concentration-response relationships for phenylephrine, carbachol, adenosine and sodium nitroprusside were obtained by adding the reagent cumulatively to the bath. RESULTS: The phenylephrine-induced contractions were markedly lower, with no change in the pD2 values (i.e. the negative logarithm of the concentration for half-maximal response), in cavernosal strips obtained from castrated rabbits than in those from controls. Endothelium-dependent relaxation elicited by carbachol increased in the castrated group but the relaxation induced by sodium nitroprusside did not change and those elicited by adenosine were strongly depressed when compared with controls. There were no significant changes in the pD2 values of agonist-induced relaxation responses in all groups. The relaxation elicited by electrical-field stimulation at lower frequencies increased in strips from castrated rabbits but at higher frequencies were unchanged when compared with controls. Castration-induced changes in the relaxation response of cavernosal strips were significantly restored by in vivo testosterone replacement but those induced by phenylephrine were not. CONCLUSION: The lack of testosterone has an effect on the reactivity of the corpus cavernosum, indicating that testosterone has an important role in erectile function by a pre- or post-synaptic action on the corpus cavernosum.     

State-space formulation for the chain parameters of nonuniform transmission lines

It is shown that the analysis of nonuniform transmission lines (n.u.t.l.s) is identical to that of linear time-varying systems when the time variable is replaced by the distance variable. Consequently, a systematic method for analytical and numerical solution of the chain parameters of n.u.t.l.s based on state equations is presented.     

Estimation of thermally stimulated current in as grown TlGaSeS layered single crystals by multilayered perceptron neural network

This paper presents an artificial neural network approach to compute thermally stimulated current (TSC) in as-grown TlGaSeS layered single crystals. The experimental data have been obtained from TSC measurements. The network has been trained by a genetic algorithm (GA). The results confirmed that the proposed model could provide an accurate computation of the TSC.     

Effect of cement type on the resistance of concrete against chloride penetration

In chloride containing environment, chloride permeability of concrete is an important parameter affecting the service life of concrete structures. The primary objective of this experimental study was to study the effect of cement types on the resistance of concrete against chloride penetration for given compressive strength classes. These cements included two different types of granulated blast-furnace slag cement (CEM III/A 32.5N and CEM III/A 42.5N), a sulfate resisting cement (SRC 32.5), and a Portland cement blended with fly ash; all of which compared to an ordinary Portland cement (CEM I 42.5R). For each binder type, four concretes at different strength classes were produced and as a result 20 mixtures were obtained. Rapid chloride ion penetration tests according to ASTM C 1202 were conducted. In addition, electrical resistivity and capillary water absorption tests were carried out. In order to characterize the concrete quality, compressive strength of the specimens were also obtained. The test results clearly demonstrated that the blast-furnace slag cements have the highest resistance against chloride penetration, while the pure Portland cement and sulfate resisting cement have the lowest resistance. Concretes produced with the sulfate resisting cement had substantially higher capillary sorption compared to other mixtures. Test results confirmed the strong relationship between the chloride permeability and electrical resistivity.     

Effect of Annealing Time and Temperature on Microstructural and Superconducting Properties of (Bi,Pb)-2212 Thin Films Produced by Magnetron Reactive Sputtering

This study deals with the role of various annealing time (1?h, 2?h, 4?h, 6?h and 8?h) and temperature (840 and 850?°C) on the microstructural and superconducting properties of thin films with the aid of scanning electron microscopy (SEM), X-Ray analysis (XRD), electron dispersive X-Ray (EDX), resistivity and transport critical current density (J _c ) measurements. The T _c , J _c , variation of transition temperatures, hole-carrier concentration, grain size, phase purity, lattice parameter, surface morphology, element distribution, crystallinity and resistivity (at room temperature) values of the films prepared are compared with each other. Critical transition temperatures (T _c ) of the samples are deduced from the dc resistivity measurement while critical current density values are estimated from the critical current and total cross-sectional area values. It is found that maximum T _c of 79.7?K and J _c of 1520?A/cm² are observed for the film annealed at 840?°C for 6?h as against 54.9?K and 30?A/cm² (minimum values), respectively, for the film annealed at 840?°C for 4?h. Moreover, SEM images indicate that the former has the best crystallinity, grain connectivity and largest grain size. Based on these results, T _c and J _c values of the samples studied are found to depend strongly on the microstructure. Additionally, EDX results show that the elements used for the preparation of all the samples are observed to distribute homogeneously. As for the XRD results, all the samples exhibit the polycrystalline superconducting phase with the changing intensity of diffraction lines. According to the refinement of cell parameters done by considering the structural modulation, the largest lattice parameter a and c are obtained for the film annealed at 840?°C for 8?h. To sum up, the aim of the present study is not only to investigate the changes of microstructural and superconducting properties of the samples fabricated in the varied time and temperature but to determine the best ambient for the film fabrication and show the feasibility of obtaining Bi-2212 film with tailored structure, as well.     

Effect of Mn Addition on Structural and Superconducting Properties of (Bi, Pb)-2223 Superconducting Ceramics

This study deals with the effect of Mn addition on the structural and superconducting properties of Bi_1.8Pb_0.4Sr₂Mn _x Ca_2.2Cu_3.0O _y ceramics with x=0,0.03,0.06,0.15,0.3 and 0.6 by means of X-ray analysis (XRD), scanning electron microscopy (SEM), electron dispersive X-ray (EDX), resistivity, and transport critical current density (J _c) measurements. Zero-resistivity transition temperatures (T _c) of the samples produced via the standard solid-state reaction method are estimated from the dc resistivity measurements. Moreover, the phase fraction and lattice parameters are determined from XRD measurements while the microstructure, surface morphology and element composition analyses of the samples are investigated by SEM and EDX measurements, respectively. It is found that T _c values are obtained to decrease from 109 K to 85 K; likewise, J _c values are observed to reduce from 3200 A/cm² to 125 A/cm² with increasing Mn addition. According to the refinement of cell parameters done by considering the structural modulation, the Mn addition is confirmed by both an increase of the lattice parameter a and a decrease of the cell parameter c of the samples in comparison with that of the pure sample (Mn0). SEM measurements show that not only the surface morphology and grain connectivity are seen to degrade but the grain sizes of the samples are found to decrease with the increase of the Mn addition as well. The EDX results reveal that the elements used for the preparation of samples distribute homogeneously and the Mn atoms enter into the crystal structure by replacing Sr and Cu atoms. The possible reasons for the obtained degradation in microstructural and superconducting properties are also interpreted.     

The effect of Pr addition on superconducting and mechanical properties of Bi-2212 superconductors

In this work, the effects of Pr doping on the superconducting, structural and mechanical properties of the samples are analyzed. Pr doped Bi-2212 superconductors are obtained using solid state reaction method. Dc resistivity measurements are made to investigate the superconducting properties, microhardness measurements are made to analyze the mechanical properties, XRD and SEM measurements are done for crystal structure determination and calculation of the lattice parameters. Using EDS measurements, the change in the elemental composition with doping is analyzed. The Vickers microhardness is calculated for undoped and doped samples. The experimental results of the microhardness measurements are analyzed using Kick’s Law, PSR (proportional specimen resistance), modified PRS (MPSR) and Hays–Kendall (HK) approach. The microhardness values of the samples decrease with Pr addition. The results can be successfully explained by HK approach.     

Decolorization of malachite green, decolorization kinetics and stoichiometry of ozone-malachite green and removal of antibacterial activity with ozonation processes

This study aimed to identify degradation intermediates and to investigate the stoichiometry of decolorization and degradation, decolorization kinetics, and removal of antibacterial activity of malachite green (MG) using ozonization processes. The decolorization of MG was optimal at an acidic pH value of 3 based on molecular ozone attack on MG molecules. The stoichiometric ratio of decolorization between ozone and MG was calculated to be 7.0 with a regression coefficient of 0.995, whereas the ratio for degradation was calculated as 13.1 with a regression coefficient of 0.998. With MG concentrations in the range of 0.30-1.82 mM, the concentration of decolorized MG increased with higher initial concentrations of MG, whereas the ozonolytic decolorization rates of MG, decreased with increasing initial concentration. The pseudo-first-order degradation rate constants (k') decreased with the initial concentration and ranged from 0.769 to 0.223 min(-1). Twelve different intermediates were produced during the ozonation of MG with ozonation times between 5 min and 30 min and were identified by GC-MS. Although 86% of MG in the reaction mixture was removed by ozonation after 10 min, the decrease of antibacterial activity was very low (10%) for Bacillus subtilis and Staphylococcus epidermidis because the degradation intermediates, phenol and benzoic acid, also have antibacterial activity. The antibacterial activity of both MG and its intermediates were removed successfully with ozonation times above 26 min.     

Highly transparent, flexible, and thermally stable superhydrophobic ORMOSIL aerogel thin films

We report preparation of highly transparent, flexible, and thermally stable superhydrophobic organically modified silica (ORMOSIL) aerogel thin films from colloidal dispersions at ambient conditions. The prepared dispersions are suitable for large area processing with ease of coating and being directly applicable without requiring any pre- or post-treatment on a variety of surfaces including glass, wood, and plastics. ORMOSIL films exhibit and retain superhydrophobic behavior up to 500 °C and even on bent flexible substrates. The surface of the films can be converted from superhydrophobic (contact angle of 179.9°) to superhydrophilic (contact angle of <5°) by calcination at high temperatures. The wettability of the coatings can be changed by tuning the calcination temperature and duration. The prepared films also exhibit low refractive index and high porosity making them suitable as multifunctional coatings for many application fields including solar cells, flexible electronics, and lab on papers.     

Multi-resolution Wavelet Analysis for Ferroresonance Phenomena in Power Systems

Power systems struggle from many effects, causing over-voltages and over-currents. One of these effects is ferroresonance, which is a non-linear phenomenon that occurs when the system is unbalanced. This article focuses on a 380-kV transmission line from Turkey's electrical power network where ferroresonance occurs during a switching operation. The system is first simulated on MATLAB (The MathWorks, Natick, Massachusetts, USA) model, and voltage variations are obtained. Spectral analysis methods are applied to the signal, and the frequency components of the system are examined for ferroresonant conditions. According to the obtained frequency components, the steady-state behavior of the system is explained.