Volume-2, Issue-3, March 2016

Abstract

The effect of losartan on systolic blood pressure (SBP), function and structure of thoracic aorta and mesenteric artery was examined. Four-week-old Wistar rats, spontaneously hypertensive rats (SHR), and SHR treated with losartan (20 mg/kg/day for 5 weeks) were used. SBP was measured by the tail-cuff method weekly. Isometric contraction of aortal rings and neurogenic contractions of mesenteric artery were studied in organ baths. For in vivo investigation after anesthesia, carotid artery was cannulated for SBP measurement and jugular vein for drug administration. Then thoracic aorta was processed according to electron microscopy procedure. In SHR (9-week-old) SBP and relative heart weight were increased, acetylcholine induced relaxation of phenylephrine-precontracted aortal rings was reduced compared to Wistar rats. In losartan treated SHR SBP and relative heart weight were lowered. Impairment of acetylcholine-induced relaxation was prevented and neurogenic responses of mesenteric artery were suppressed. In vivo administration of acetylcholine (0.1µg, 1µg, 10µg) evoked similar decrease of SBP in SHR and Wistar rats. In losartan treated SHR the decrease of SBP was larger than in SHR and Wistar rats. Wall thickness (WT) and cross-sectional area (CSA) of the aorta in SHR were decreased compared to Wistar rats; inner diameter (ID) and WT/ID ratio were not changed. In losartan treated SHR ID was increased and WT/ID decreased while WT and CSA were not changed. Conclusion: Losartan administered to SHR (i) reduced SBP, (ii) prevented impairment of endothelium-dependent relaxation, (iii) improved integrated responses to acetylcholine, and (iv) reduced structural changes in the aortic wall. 

Keywords: Hypertension, Conduit artery, Losartan, Neurogenic contraction, Structure.

References

Keywords: Hypertension, Conduit artery, Losartan, Neurogenic contraction, Structure.

Abstract

This paper proposes a dynamic model of a VSC (voltage source converter) based Back to Back HVDC system and its control technique. From the system model, the corresponding relationship between the controlling and the controlled variables of the VSC is determined. The vector control technique is used to control the working of converters. The control structure consists of outer control loop and inner control loop. The outer loop controller controls the active and reactive power separately. The inner loop controller which is a fast working controller provides the reference d- axis and q- axis voltages which are required by the PWM for generating the triggering pulse. The validity of the model and the feasibility of the control method have been proved by the simulation results. In this paper the system performance is studied under steady state condition. 

Keywords: Inner loops Controller, outer loops Controller, Vector Control, VSC HVDC.

References

Keywords: Inner loops Controller, outer loops Controller, Vector Control, VSC HVDC.

Abstract

Conducting solid phase polymer electrolyte (SPE) films were synthesized using solution casting method. The polyethylene oxide [PEO] complexed with an alkali salt sodium perchlorate [NaClO4] and nano-filler Nb2O5 with varying weight percentile [5%-15%] ratios. The complexation of NaClO4 salt with the polymer matrix PEO has been confirmed by XRD and surface morphology was understood by the SEM images and elemental composition was estimated by EDAX results. The AC conductivity measurements were done in the temperature range of 303K–343K using AC conductivity set up. The electrical conductivity shows an improvement and enhanced to fourth order. The conductivity in polymer electrolyte system is due to ions of alkaline salts and Nb2O5 nano-filler which are present in polymer matrix. Several electrical and dielectric characterizations were done for these films. 

Keywords: Activation Energy, Conductivity, Dielectric properties, Nanocomposite Polymer Electrolyte [NCPE], solution cast technique.

References

Keywords: Activation Energy, Conductivity, Dielectric properties, Nanocomposite Polymer Electrolyte [NCPE], solution cast technique.

Abstract

One way of checking on a pregnant woman is inspection using ultrasonic wave Doppler technique, this check is done by putting Doppler ultrasonic waves over the abdomen to capture the heart beat of the fetus with the addition of the gel material, there sebaga in pregnant women who are allergic to the gel material. Alternatively we can use the technique in frassonik waves. With a digital design II Chebyshev band pass filter with a frequency range of 2-3Hz, the heart rate of pregnant women with fetal heart beat can be distinguished. With the help of software MatLab and Xilink will be resolved in the manufacture of digital filter terser but. The simulation results with the software quite satisfactory. 

Keywords: heartbeat, infrasound.

References

Keywords: heartbeat, infrasound.

Abstract

We present the effect of hydrogen on surface characterization by Rf magnetron sputtered ZnO:Al thin films. ZnO:Al films are self textured and surface roughness of ZnO:Al films varies with H2 dilution ratio and ultimately affects on diffused transmittance varies from 41-27% with the variation of hydrogen (5-40%) with improved resistivity of 3.9×10-4 Ωcm. The light scattering effect of hydrogen textured thin films was evaluated by the measurement of diffused transmittance. Experimental result shows that introduction of hydrogen effect significantly improved the light trapping in terms of diffuse transmittance without affecting electrical and other optical properties of ZnO:Al thin film.  

Keywords: ZnO:Al, RF magnetron sputtering, transparent conductive oxides, Atomic force microscope, Diffused Transmittance.

References

Keywords: ZnO:Al, RF magnetron sputtering, transparent conductive oxides, Atomic force microscope, Diffused Transmittance.

Abstract

Because of biodegradability and non-toxicity biodiesel has become more attractive as alternative fuel. Biodiesel is produced mainly from vegetable oils by transesterification of triacylglycerols. From economic and social reasons, edible oils should be replaced by lower-cost and reliable feed stocks for biodiesel production such as non-edible plant oils. Biodiesel is considered an alternate and renewable substitute for petro-diesel. Pure vegetable oils and animal fats are being widely used for biodiesel production which is resulting in increased food cost and thus causing economic imbalance. In this research, inedible oils e.g. Jatropha oil is investigated for biodiesel production through transesterification process by using CaO-Al2O3 nanocatalyst, synthesized via top down technique. The synthesized nanoparticles were then characterized by XRD. The average crystallite size determined by XRD analysis was 29.9nm.It was calculated by using the Scherrer equation.  These nanoparticles were tested to be used as a nanocatalyst for the production of biodiesel from Jatropha curcas oil. The fatty acid content of the oil and the biodiesel was analyzed using Gas Chromatography-Mass Spectroscopy (GC-MS). Propanoic acid (C5H10O3) was observed to be the most abundant compound present in methyl esters. Methanol to oil molar ratio of 3:1 and 5:1 were investigated for optimization process. The optimization results for production of biodiesel from the transesterification of Jatropha curcas oil catalyzed by CaO-Al2O3 nanoparticles showed maximum yield i.e. 82.3% at 5:1 methanol to oil molar ratio. 

Keywords: Jatropha curcas oil, CaO Nanoparticles, Al2O3 Nanoparticles, biodiesel, Transesterification.

References

Keywords: Jatropha curcas oil, CaO Nanoparticles, Al2O3 Nanoparticles, biodiesel, Transesterification.

Abstract

 Keyhole welding using concentrated energy beams (electron beam and laser beam) is at the forefront of welding technology and finding ways to improve welding quality is a pressing issue. Finding optimal welding modes, monitoring weld quality and/or detecting weld defects in real-time during the welding process using nondestructive, costeffective and reliable methods is one of current challenges. Plasma generated in the keyhole and the plasma plume (space above the welding pool) provides an opportunity to study welding stability and optimal modes as well as formation of weld defects.

Generation and characteristics of plasma in the keyhole and above the welding pool are discussed in the paper. For laser keyhole welding spectral analysis data and video image techniques are widely used for control and inspection of laser induced plasma in real time. Electron beam welding is studied using plasma parameter measurements and by studying the current collected by the positively polarized ring electrode above the welding pool. In case of electron beam welding with beam oscillations the method of coherent accumulation is applicable to analyze of the plasma fluctuations process at the plasma electron current. 

Keywords: keyhole welding, electron beam welding, laser welding, plasma plume, welding quality, process monitoring, spectral analysis, plasma diagnostics, weld defects

References

Keywords: keyhole welding, electron beam welding, laser welding, plasma plume, welding quality, process monitoring, spectral analysis, plasma diagnostics, weld defects

Abstract

This paper mainly modifies and further develops the comprehensive national strength model. By modifying the basic comprehensive national strength model, it can more accurately illustrate the society phenomena with time delay. First, we research the dynamics of the modified with time delay. By employing the normal form theory and center manifold method, we obtain some testable results on these issues. The conclusion confirms that a Hopf bifurcation occurs due to the existence of stability switches when the delay varies. Finally, some numerical simulations are given to illustrate the effectiveness of our result. 

Keywords: Hopf bifurcation, Stability, Comprehensive national strength model, Center manifold, Normal form.

References

Keywords: Hopf bifurcation, Stability, Comprehensive national strength model, Center manifold, Normal form.

Abstract

In this study adherent films of polythiophene were deposited by electropolymerization of thyhiophene monomer ,onto stainless steel 316,carbon steel (C45), and aluminum (6061), the  anticorrosion  performance in artificial seawater (3.5% NaCl) solution were investigated at four temperatures, namely 20,30,40,50ᴼC using Tafel plots. The FTIR, XRD, TG, AFM, and SEM techniques, were used to evaluate the polythiophene deposited layer, they revealed nanofibers like structures with diameters around 40-50 nm , the thermal stability reach 300ᴼC. 

Keywords: polythiophene , electropolymerization , corrosion protection, nanostructure

References

Keywords: polythiophene , electropolymerization , corrosion protection, nanostructure

Abstract

Analyzing conventional cleanrooms, we have proposed and demonstrated how well Clean Unit System Platform (CUSP) works. The CUSP serves as a clean versatile environment having low power-consumption and high costperformance, and is suitable not only for processing the next generation new devices, but also for cross-disciplinary fields, including medical/hygienic applications. CUSP can provide us with dust- and microbe-free environment as good as US FED 209E class 10 in room-type CUSP, and class 1 with foldable CUSP (F-CUSP). Sleeping in F-CUSP has opened a window for Kinetosomnogram, which, based on the analysis of the peaks in the particle-count and the autocorrelation of them, would contribute to evaluation of sleep quality and/or sleep disorders. The F-CUSP as well as a capsule CUSP that operates with tiny FFU covering minimum volume can reduce the risk of MERS or other diseases mediated by air-borne microbes. With its full line-up, CUSP can outperform conventional super cleanrooms (“main frames”) and also provides us with environment suitable, especially, for those people under the risk of suffering from particulate matters (PM) 2.5, airborne microbes, or other foreign materials. The CUSP would be the clean space for all of us. 

Keywords: Clean environment, CUSP, kinetosomnogram, microbe-free environment, Tent-type CUSP (T-CUSP).

References

Keywords: Clean environment, CUSP, kinetosomnogram, microbe-free environment, Tent-type CUSP (T-CUSP).

Abstract

In VLSI design, one of the most important detailed routings is the channel routing. Given a channel with length n in 2-layer Manhattan model, Szeszler proved that the width (number of tracks required for routing) of the channel is at most 7/4 n, and this upper bound can be achieved by a linear time algorithm. In this note, we improve the upper bound 7/4 n to 3/2 n, which also can be achieved by a linear time algorithm.

Keywords: Channel routing, Graph Theory, VLSI design.

References

Keywords: Channel routing, Graph Theory, VLSI design.

Abstract

Purpose: The aim of this study was to evaluate the possible role of fused images (anatomical CT and functional FDG-PET), acquired with a combined PET-CT scanner, in delineating gross tumour volume (GTV) and clinical target volume (CTV).

Materials and Methods: Twenty-nine patients with small cell or non-small cell lung cancer were studied. CT and FDG-PET images were obtained in treatment position in a combined PET/CT scanner. FDG-PET and CT images were transferred to a workstation for contouring. Gross Tumor Volumes (GTV) and Clinical Target Volumes (CTV) were defined first using the CT data alone and then using the registered CT and FDG-PET data. For each patients two three Dimensional Conformal Radiotherapy (3DCRT) plans were made and they were compared with respect to the GTV, CTV, mean lung dose and volume of normal lung receiving ≥20 Gy (Vlung20Gy)

Results: Out of these 29 patients, PET clearly changed GTV in 17 patients. PET increased CTV in 7 patients. Additional unsuspected regional nodal disease was included in these patients. In 16 patients with atelectasis, decrease in CTV led to reduced radiation dose to the lung. Likewise, with additional PET information, CTV was enlarged and values of MLD and Vlung20Gy were increased in 5 patients.

Conclusion: The use of PET/CT images in radiotherapy is helpful in defining tumor location more precisely, possibly sparing more normal lung tissues and also helpful in differentiating tumor from atelectasis lung. The increasing availability of combined PET/CT units will facilitate the use of this technology for radiation treatment planning. 

Keywords: Lung Cancer, Image Fusion, PET/CT, Target Definition, Treatment Planning.

References

Keywords: Lung Cancer, Image Fusion, PET/CT, Target Definition, Treatment Planning.

Abstract

Sequential cellular events after highly purified β-tricalcium phosphate (β-TCP) implantation with or without rat bone marrow (BM) cells were investigated. β-TCP disks were soaked with BM cells harvested from femora of syngeneic rats and implanted into the subcutis of eight-week-old rats. Specimens were harvested at the intended stages, and histological examinations were performed.

In the BM-treated group, new bone formation was detected, and intense signals of the α1 chain of type I procollagen mRNA were expressed in osteoblasts after day 14. On day 56, the newly formed bone did not degenerate, and normal bone marrow tissue was observed. TRAP-positive multinucleated cells appeared after day 7, and cathepsin K–positive osteoclasts appeared after day 14, directly attached to β-TCP.

Conversely, in the BM non-treated group, new bone formation was not observed even on day 56, and neither TRAP- nor cathepsin K–positive osteoclasts were detected at any stage. Quantitative analysis showed that the β-TCP area decreased in a time-dependent manner in the BM-treated group, but not in the BM non-treated group.

In conclusion, these findings indicate that β-TCP loaded with BM cells has osteoinductive ability. β-TCP is resorbed mainly by osteoclasts, and this event promotes ectopic bone formation. BM cells play an important role in osteoinduction as well as in osteoclast differentiation and function.

Keywords: Bone marrow cells; Osteoinduction; Osteoclasts; β-tricalcium phosphate.

References

Keywords: Bone marrow cells; Osteoinduction; Osteoclasts; β-tricalcium phosphate.

Abstract

Metal matrix composites reinforced ceramic particles, are widely used in industry, wherever high resistance to abrasive wear, erosion and corrosion is necessary. Cermets, in which titanium carbide (TiC) is used as reinforcing phase, are particularly interesting for improving the strength, stiffness and wear resistance, especially at elevated temperatures. The paper presents the results of corrosion tests of titanium matrix composite reinforced nc-TiC particles, at different stages of surface preparation: grinding, polishing, electropolishing and oxidation in the furnance. Measurements of potentiodynamic polarization curves in 3% NaCl solution were performed. The results have showed the negative impact of the nanocrystalline TiC strengthening phase on corrosion resistance of composites. It was also found that electropolishing treatment is the most preferred way to prepare the surface for titanium as well as TiC reinforced composites. 

Keywords: Metal matrix composite, titanium, titanium carbide, corrosion resistance, SLM.

References

Keywords: Metal matrix composite, titanium, titanium carbide, corrosion resistance, SLM.

Abstract

In this work, the effect of Sr doping concentration on the morphological and luminescence properties of Ba2SiO4:Eu2+ phosphors was studied. Green-yellow emitting phosphors (Ba1-xSrx)2SiO4 activated with Eu2+ ions were fabricated by pressure-assisted combustion synthesis (PACS) at an initial pressure of 3.4 MPa. The Sr (x) atomic concentration was changed from 0.0 to 0.5 at.%. The X-ray diffraction (XRD) analysis showed that these phosphors have a single phase corresponding to the Ba2SiO4 orthorhombic phase. Different morphologies with sizes in the range of 1-12.12 µm were observed according to the Sr content, such as spheres-like (x=0.0 at.%), irregular-shaped (x=0.2 at.%) and rectangular flakes-like particles (x=0.5 at.%).The main emission bands were located in the range of 507 to 522 nm, which correspond to 4f-5d allowed electric-dipole transition of Eu²+ and the main excitation band was located at 397 nm. The phosphor with flakes-like morphology (x=0.5 at.% of Sr) exhibited the highest luminescent intensity and its CIE coordinates are (0.31, 0.60) which color is located in the green region.  The strong green-yellow emission observed in our phosphors suggests that they can be useful for the green component in RGB white LEDs. 

Keywords: (BaSr)2SiO4, combustion synthesis, luminescence, phosphors, white light-emitting diodes (WLEDs).

References

Keywords: (BaSr)2SiO4, combustion synthesis, luminescence, phosphors, white light-emitting diodes (WLEDs).

Abstract

To improve the performance of hybrid concatenated convolutional codes (HCCC); a modified Log-MAP algorithm and an enhanced HCCC are introduced and demonstrated to be efficient and practical by simulation results. The new coding scheme achieves about 1.0 dB additional coding gain, compared to the general turbo coding scheme at a BER = 10-6, with a frame length of 8192-bit. The system complexity and decoding latency of the new scheme is lower than the HCCC proposed by Divsalar and Pollara [6] within acceptable performance degradation. Since the bit-error-rate of the proposed HCCC can be dramatically reduced by slightly increasing signal-to-noise ratio, the new hybrid concatenated coding scheme is very suitable for those communication environments in which high reliability is important. 

Keywords: hybrid concatenated convolutional codes (HCCC), bit-error-rate, coding gain.

References

Keywords: hybrid concatenated convolutional codes (HCCC), bit-error-rate, coding gain.

Abstract

Natural gas is poised to occupy a more prominent place in the global energy balance, coupled with other renewable energy sources, natural gas is an energy source of choice for the development of Africa and offers a vehicle for its integration with the world economy. The Economic Sustainability and expected benefits of Nigerian gas reserves are estimated at 5 trillion cubic meters – equal to roughly ten years of consumption of the EU. The modeling approach for long distance natural gas pipeline is optimized and design for the minimum installation cost. In this research paper the minimum cost for the installation of long gas pipeline is obtained by designing the different set of pipeline networks for which the installation costs are estimated and compared with the minimum capital cost. Various available pipeline systems are designed by varying the compressor station spacing for different standard pipe diameters. Accurate installation costs for each obtained pipeline network are estimated by using an advanced cost estimating computer program which uses real and updated data for the estimation. These total costs of the various pipeline networks are compared to obtain a minimum installation cost. The 1000km pipeline is divided into a number of short sections to calculate the pressure drop along the pipeline length.  The design pressure is considered according to the 600 flange rating, 1,350 Psig and 90% of the design pressure is envisaged for the maximum operating pressure for the pipeline design. 

Keywords: Tran-Sahara, Transmission, Pipeline, Minimum cost.

References

Keywords: Tran-Sahara, Transmission, Pipeline, Minimum cost.

Abstract

 The development of design have been discussed adopted various types methods use. The Hadi and Arfiadi Method presents a formulation for the optimum rigid road pavement design by genetic algorithm, a new method. The Westergaard’s Method determines the stresses in the rigid concrete slab and also the pressure-deformation curve which depend upon the relative stiffness of the slab and the subgrade. Razouki and Al-Muhana also developed stress charts similar to Westergaard’s method. The paper reveals that the effects on the maximum bending tensile stress are quite significant due to the modulus of subgrade reaction, modulus of elasticity of concrete and slab The Maharaj and Gill method have performed axisymmetric finite element analysis by varying parameters, the thickness of pavement, pressure and elastic modulus of subgrade. The advantage of this method is that four types of design charts have been presented which other methods have note done. First type of design chart has been plotted between thickness of pavement and nodal deflections for various pressures for a particular elastic modulus of soil. Second type of design chart has been plotted between thickness of pavement and element stress for various pressures for a particular elastic modulus of soil. The third type of design chart has been plotted between thickness of pavement and nodal deflections for various elastic moduli of subgrade  for a particular pressure. Each of the design charts has three parameters. For two known parameters, the third parameter can be obtained. 

Keywords: Rigid pavement, Design Chart, Elastic Modulus of Subgrade, Finite Element Analysis, Thickness of Pavement.

References

Keywords: Rigid pavement, Design Chart, Elastic Modulus of Subgrade, Finite Element Analysis, Thickness of Pavement.

Abstract

The adder is most commonly used arithmetic block of CPU (central processing unit) and DSP (digital signal processing), therefore its power and performance optimization is very important. With the scaling of technology to deep submicron, the speed of the circuit increases rapidly. At the same time, the power consumption per chip also increases significantly due to increasing density of the chip. Therefore, in realizing modern VLSI circuits, low power and high speed are the two predominant factors which need to be considered. In this work, there is try to determine the best solution to this problem by improving the performance of adders.

In this work, we improve and compare the power consumption of the three adders. The conventional full adder is built by 28 transistors. So, the transistor count is very high. The average power consumption and delay are very high. In this work, we consider three types of 64-Bit adders and try to improve their performance by varying width and length of substrate. For this purpose, we use tanner tool. 

Keywords: CSL, CPL, DPL, Low power design

References

Keywords: CSL, CPL, DPL, Low power design