The EFFECT OF HYDROPHYTES ON THE PERFORMANCE OF SECONDARY CANAL

The hydrophytes in canal effect directly canal performance by reducing water velocity, enhances sedimentation and reduce canal cross section area which raise water level and reduces water flow. Indirectly the hydrophytes detaches from their origin and flow with water stuck with outlet and reduces its proportionality. In this regard a study was conducted on secondary canal known as Yar Husain Minor (YHM) of Maira Branch Canal, which is part of the Upper Swat Canal Irrigation System in Khyber Pakhtunkhwa, Pakistan. Maira Branch Canal and its secondary canal were designed for Crop Based Irrigation Operation (CBIO), which could supply irrigation water for maximum copping intensity (180%) even during peak periods of irrigation requirements. The current water allowance was 0.67 Ls-1 ha-1 (6.6 mm day-1), which was based on the maximum crop water requirements. The several challenges for operation of YHM and other secondary canals of Maira Branch came from physical barrier mostly in the form of hydrophytes on the performance of YHM canal. Further challenges came from the fact that it receives water from River Swat which is turbid in summer and River Indus (Tarbela Reservoir) which is clear with low turbidity. This caused sedimentation and growth of hydrophytes in the YHM. Furthermore Triangular Profile Crump’s weirs were in all secondary canals including YHM for proportional division to the tertiary outlets (moghas). The study objectives were to investigate the effects of hydrophytes on canal capacity and at the outlets on the performance of the YHM. Hydrophytes growth was observed in head reaches of canal and samples were collected and were identified at the Department of Weed Science & Botany, The University of Agriculture Peshawar. Five types of aquatic weeds were identified. The hydrophytes growth in canal head reaches directly reduces the cross section by more than 50%. Indirectly the detached hydrophytes were get stuck in the outlets and affected its performance. Therefore, daily discharges were measured with/without detached hydrophytes at each outlet from staff gauging. Frequency was based on days stone hydrophytes present divided by total time. It was concluded that secondary canal performance was low due to hydrophytes. The hydrophytes and users interventions influenced the outlets performance by 80%. Trifurcators type outlets were more prone to influence by hydrophytes followed by bifurcators outlet.

Modeling of the dynamics of tornado structures in a pipe with turbulators of square, semicircular and triangular profiles

Objectives. To carry out mathematical simulations of changes in time of tornado compositions in channels with projections of semicircular, triangular, square profiles for average Reynolds criteria based on multiblock computing technology with the solution of finite- volume factorized methods of the Reynolds equation and energy equations.Method. The calculations were carried out on the basis of theoretical approaches based on the solution of Reynolds equations by finite-volume factorized methods, which were closed using the simulation of Menter stresses, and the energy of a structured grid.Result. The calculations of time-dependent flow and heat transfer parameters carried out in the article showed that the excess dissipation of turbulence generation for projections of sharp profiles - square profile, triangular profile - and rounded profiles - semicircular profile, segment profile - is provided with radically different hydraulic losses: channels with protrusions of rounded profiles, for example, semicircular, have much lower hydraulic resistance coefficients than channels with protrusions with sharp profiles, for example, triangular or square, rectangular.Conclusion. In the article, mathematical simulations of time-dependent tornado compositions were performed in channels with transversal profiles in the form of a square, triangle and semicircle, which is as informative as possible in terms of studying turbulent flows and heat transfer arising under average Reynolds criteria based on computer multiblock technology when using solutions of finite-volume factorized methods (FCOM-am) Reynolds equations and energy equations. The following protrusions were considered in the article: square transversal profiles, in which tornadoes are most pronounced, and side tornadoes affect the flow in the maximum way; triangular transversal profiles, where tornadoes are not so strong, and side tornadoes affect the main flow weaker than with square protrusions; semicircular transversal profiles, in which the incoming main tornado moves along the stream with the generation of limited side tornadoes. The calculated information obtained in the article correlates to a high degree with the available experimental data, which indicates the verification of the mathematical modeling involved in the article.

Shear-Driven Mechanism of Temperature Gradient Formation in Microfluidic Nematic Devices: Theory and Numerical Studies

The purpose of this paper is to show some routes in describing the mechanism responsible for the formation of the temperature difference ΔT at the boundaries of the microfluidic hybrid aligned nematic (HAN) channel, initially equal to zero, if one sets up the stationary hydrodynamic flow vst or under the effect of an externally applied shear stress (SS) to the bounding surfaces. Calculations based on the nonlinear extension of the classical Ericksen–Leslie theory, supplemented by thermomechanical correction of the SS σzx and Rayleigh dissipation function while accounting for the entropy balance equation, show that the ΔT is proportional to the heat flux q across the HAN channel and grows by up to several degrees under the influence of the externally applied SS. The role of vst=ust(z)i^ with a sharp triangular profile ust(z) across the HAN in the production of the highest ΔT is also investigated.

Intensity of Electromagnetic Wave into Layers with Fluctuations of Dielectric Permittivity

The study is made of the intensity of a plane electromagnetic wave propagating into the layer with random discrete irregularities of the dielectric permittivity. The mean intensity of scattered field as a function of the parameters of random irregularities of rectangular and triangular forms is analyzed. It is shown that the deviation of the average intensity from the unperturbed value increases both the average amplitude and its standard of fluctuations. It is found that the amplitude of the intensity oscillations for a layer with irregularities of the rectangular shape is significantly greater than for fluctuations with the triangular profile.

A Modified Cylinder Block – Ic Engine Experimentation

In Internal combustion Engines, the adequate cooling plays vital role for proper functioning and enhanced efficiencies. In the present scenario, the demand for Air cooled Engines with higher powers is increasing and hence necessity for Augmented heat transfer through fins. The present work confined to fins mounted on the cylinder block.In the present work, Internal Combustion Engine test rig is used, which consist of 4S, single cylinder, vertical, air cooled, SI Engine with Instrumentation panel, Throttle control mechanism and Electrical Loading system.The performance test on IC engine is carried out for three various configurations of cylinder blocks i.e., 1. Actual cylinder block 2.Cylinder block with triangular profile fins 3. Cylinder block with perforated triangular profile fins. Performance parameters are evaluated, plotted and compared & eventually conclusions are made.

Дифракционные решетки с блеском, получаемые на пластинах Si --- первые результаты

Using direct laser lithography and liquid etching of polished vicinal Si(111) wafers, a technology was developed and diffraction gratings 500 /mm with a blaze angle of 4° were fabricated. The manufacturing process of a reflective Si-grating of a triangular profile (sawtooth) can be divided into four main steps: (1) obtaining a pattern of a protective mask for etching grooves; (2) anisotropic etching of grooves in KOH solution; (3) etching to smooth the grating profile and polish the surface of working facets; (4) coating to increase reflectivity. The samples obtained were characterized using scanning electron microscopy and atomic force microscopy methods to determine the shape of the groove profile and roughness: the shape turned out to be close to the ideal triangular, and the root-mean square roughness was less than 0.3 nm. With the help of the PCGrate™ code, taking into account the measured real groove profile, the diffraction efficiency of gratings operating in classical and conical mounts in soft-X-ray and extreme ultraviolet radiation has been simulated. The obtained efficiency values are close to the record ones for the corresponding spectral range and the Au-coating of the grating.

Effect of External Post-Tensioning Strengthening Technique on Flexural Capacity of Simple Supported Composite Castellated Beam

This research is carried out to study the effect of the external post-tensioning technique on the flexural capacity of simply supported composite castellated beam experimentally. In this research, seven composite castellated beams having the same dimensions and material properties were cast and tested up to failure by applied two concentrated loads at 700 mm from each end. Two external strands of 12.7 mm diameter were fixed at each side of the web of strengthening beams and located at depth 180 mm from top fiber of the section (dps) at each end of the beam. The strands have been tensioned by using a hydraulic jack with a constant stress of 100 MPa. This research aims to study the effect of the strengthening by different shapes of strand profiles of external post-tensioning techniques on the flexural capacity of the composite castellated beam. These beams were divided into three groups. Each group contained two composite castellated beams while 7th composite castellated beam kept without strengthening by external post-tensioning technique As control beam. The first group included two beams with straight strand profile of external Post-tensioning. The second group included two beams with a triangular strand profile of external post-tensioning. The third group included two beams with a trapezoidal strand profile of external post-tensioning. All composite castellated beams were simply supported, and all of them were fully shear connections between the concrete slab and steel girder. All beams included the 16 castellated openings and were stiffened by six stiffener plates welded on the web of castellated beams. Three stiffener plates are welded on each side of the web. Two of these stiffener plates welded at the middle of the beam, and four of them welded at locations under the loads. The experimental results of this research were increasing 5.43% in load capacity of an average of the straight profile of composite castellated beams, increasing 18.92% in load capacity of an average of triangular profile composite castellated beams, and increasing 20.71% in load capacity of the trapezoidal profile of composite castellated beams. All the above results were compared with control beams.

The photonic nanojets formation by two-dimensional microprisms

Using the finite difference method implemented in the COMSOL Multiphysics software package, the focusing of laser radiation by dielectric prisms with a triangular profile was numerically investigated. It was shown that two-dimensional triangular prisms make it possible to focus light in free space into spots with dimensions smaller than the scalar diffraction limit. In particular, a silica glass prism with a base width of 60 μm and a height of 28.5 μm forms a photonic nanojet with a maximum intensity of 6 times the intensity of the incident radiation and a width of FWHM=0.38λ. A prism from barium titanate with a base width of 60 μm and a height of 20 μm allows to obtain a photonic nanojet with the same width (0.38λ) and a maximum intensity 5 times the intensity of the incident radiation. The size of the focal spot can be reduced further if the height of the prism is selected so that the maximum intensity is located inside the material of the prism. For example, a barium titanate prism with a height of 21 μm and a base width of 60 μm forms a focal spot with a width of FWHM=0.25λ.

Lamb wave imaging with actuator network for damage quantificationin aluminum plate structures

Lamb waves have been widely used for damage detection on plate-like structures. However, there are still considerable interests on quantifying damage with complex profile. In this article, quantification of complex damage in plate-like structures using a network of actuators and time-space Lamb wavefield is investigated. The actuator network inspection system is implemented with multiple PZT transducers for Lamb wave actuation in round robin pattern and scanning laser Doppler vibrometer for wavefield sensing. The PZT network is arranged in a way that the target area is fully enclosed and Lamb waves come to the damage from all directions. Waves induced by the damage are subsequently obtained through frequency-wavenumber filtering, using the experimentally acquired dispersion curves presented in the paper. The filtered waves from all wave actuators are then used to generate a synthetic image of the damage being inspected. Two cases of complex damage are evaluated on aluminum plates, mass loss with triangular profile and mass addition with a three-letter cluster profile. Our results show that the damages are not only detected but also their profiles are clearly outlined in the images. We believe the subject methods provide improved evaluation of damage profile for Lamb wavefield based damage quantification.