Hydrodynamic characteristics of lateral withdrawal with effects of the slope ratio

Lateral withdrawal is widely performed in water transfer and water supply projects. Hydrodynamic characteristics of intake are crucial to safe and stable operation. In this study, a 3-D numerical volume of fluid model was established and validated through experimental tests. Hydrodynamic characteristics and secondary flow were investigated under scenarios with the vertical slope and different slope ratios. The helix-shaped recirculation and surface vortex are generated, and the secondary flow near the surface layer is more serious. Adding a slope ratio is beneficial to improve the flow patterns and recirculation, while the surface vortex width increases. Additionally, with the decrease in the slope ratio, recirculation width and the ratio of recirculation to the width of the layer decrease, and the minimum values are 9.19 cm and 22.97%, respectively. However, the lower the slope ratio is, the greater recirculation inhibition affects are, and the more serious the surface vortex is. With the decrease in the slope ratio, the widest surface vortex width and the ratio of the widest surface vortex to the width of the layer increase from 6.1 to 12 cm and from 7.82 to 17.14%, respectively. This research represents an advance in lateral withdrawal and provides support for further designs.

Empirical Correlations between the Hydraulic Properties Obtained from the Geoelectrical Methods and Water Well Data of Arak Aquifer

A number of empirical correlations have been achieved between the hydraulic properties measured through geoelectrical methods and water well data of Arak Aquifer located in Markazi province, Iran. The geoelectrical method of Vertical Electrical Sounding (VES) technique was used to calculate the hydraulic properties of the aquifer. Through the VES technique, the pivotal hydraulic properties such as porosity, hydraulic conductivity, and specific yield of the layers were calculated. The results of VES technique were compared with the data obtained from seven observation water wells that were already drilled as exploratory coring boreholes in the region. The results demonstrate that as the porosity and hydraulic conductivity of the water-bearing layer increase, the results of VES technique appear much identical to the water well records. Furthermore, the specific yield was calculated as 4.6% that was very close to the value of 3.5% measured through the previous pumping tests. Moreover, VES technique predicted the water table of the aquifer very close to the water level monitored in the observation water wells. The obtained correlations can be used as an alternative for drilling of new observation wells that are inefficient in time and expense, and may encounter environmental limitations of drilling and site construction.

Elasticity Modulus and Hardness of Bearing Steel after Laser Treatment

The article considers the effect of laser treatment of bearing steel on the change in the elasticity modulus and hardness of the steel SHH15SG. Multi-factor models were obtained that relate the output parameters to the power W of laser radiation, the longitudinal feed Spr of the laser beam and the distance L from the protective glass of the focusing head to the workpiece surface. According to the degree of reduction of the influence on the elastic modulus of steel SHH15SG subjected to laser treatment, these factors are arranged in a sequence: W, Spr, and L. With increasing W and L the modulus of elasticity and hardness of the treated surface layer increase. 3M-XYZ surface-graphs, 3M-XYZ contour-graphs of interactive influence of independent factors on the elastic modulus and hardness of the surface layer are constructed, which simplifies the procedure for assigning the processing mode. The research results are useful for manufacturing and design companies that implement laser technologies and create laser equipment.

Corporate Citizenship

The last few decades have witnessed serious sustainability challenges such as economic uncertainty, depletion ozone layer, increase in pollution, urban decay, overpopulation, degradation, and shortage of natural resources, etc. The increasing pace of change and rising competition has posed unknown challenges and unparalleled pressure on the corporates not only to prosper, but also to sustain in future. With customers, investors, and other stakeholders becoming increasing aware and critical about sustainable practices, the companies are forced to think past short term monetary gains. As there exists an interdependence, integration, and co-creation among the three basic tenets of sustainability-people, planet, and profits. There is a global call on companies to pursue socially responsible conduct and adopt innovative practices which create value for people, planet, as well as economy.

Simulation Calculation on the Failure Mode of the Big-size Sandbag Cofferdam on Soft Foundation

The offshore engineering develop fast in recent years, a new method named “big-size sandbag cofferdam” is applied to many practical projects in China. The sandbag is made of geotextile with large sizes in length and width. Sandbags are filled with pumped sea sand and stacked together layer by layer. Many theoretical obstacles remain unsolved, which has restricted the application of this advanced technology. Based on an instability project located in Bohai Bay, the failure mode of the big-size sandbag cofferdam on soft foundation was studied. The results show that the deformation of cofferdam was concentrated on the bottom sandbag, under the action of insufficient foundation bearing capacity and overburden load, the stress of the geotextile at the bottom layer increase sharply during the fast filling, then exceed its ultimate tensile strength, and the cofferdam would be pulled apart from the bottom to top, lead to a continuous penetrating sliding surface failure of big-size sandbag cofferdam.

INVESTIGATION METHOD OF THERMAL FRICTION PROCESSING OF THE ECCENTRIC CONE CRUSHER PART

The article presents the results of the study performance of cone crushers and the existing technology restoration of their parts. The main reasons for the failure of cone crushers are the following: failure armor of the cone and the middle part, the protective cap, parts of the upper suspension, dust seal rings, bearing rings, the eccentric of the crusher. The most time-consuming is to restore the details of the eccentric crusher. A new technology restoration worn surfaces of the eccentric part and the results of an experimental study of thermal friction treatment (TFТ) after surfacing are proposed. It is revealed that despite the high level of temperature corresponding to intensive treatment modes it is possible to achieve effective hardening. Implementation of the proposed technology allows: eliminate the undesirable effects of softening due to re-riveting and reduce the oxidized layer; increase productivity relative to mechanical cutting methods in 23 times and tool life of more than 10 times; the use of affordable cheap material steel 45, 50, 60G for the manufacture of tools and perform processing at more intensive modes S =0,2-1mm / Rev; n=2000-3000 rpm. It is established that the TFO of the deposited surface part eccentric, provides wear resistance of the treated surfaces parts in 2….8 times more than the factory processing technology, while the depth of the hardened layer can be 1.5…. 2 mm.

MOLECULAR DYNAMICS STUDY ON LIQUID FILM EVAPORATION ON THE FRACTAL ROUGH SURFACES

A molecular dynamics simulation is performed to study the liquid film evaporation on rough surfaces constructed by the Cantor set fractal. The liquid film evaporation on the rough surfaces with different roughness and fractal dimensions is presented and is compared with that on smooth surface. The results indicate that the response speed for evaporation on the rough surface is faster than that on the smooth surface and is accelerated with the increase of the roughness height and the fractal dimensions. Protrusions on the rough surface are conducive to heat transfer enhancement, and thus, the evaporation on a rough surface can reach equilibrium earlier than that on a smooth surface. With increasing roughness and fractal dimension, the evaporation rate and the thickness of the non-evaporating liquid layer increase.

Fabrication and characterization of porous silicon for humidity sensor application

Porous Silicon (PS) layer has been prepared from p-type silicon by electrochemical etching method. The morphology properties of PS samples that prepared with different current density has been study using atom force measurement (AFM) and it show that the Layer of pore has sponge like stricture and the average pore diameter of PS layer increase with etching current density increase .The x-ray diffraction (XRD) pattern indicated the nanocrystaline of the sample. Reflectivity of the sample surface is decrease when etching current density increases because of porosity increase on surface of sample. The photolumenses (PL) intensity increase with increase etching current density. The PL is affected by relative humidity (RH) level so we can use as humidity sensor. The electrical resistivity has been increased after PS layer formed due to the variation of the pore size and it was much higher after increase etching current.