Papers by Keyword: Operating Parameters

Abstract: The iron waste collected from steel workshop was evaluated as a catalyst in heterogenous photo-Fenton like process. The analyses such as X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were carried out to assess the morphology, chemical structure and chemical composition of the iron waste. The degradation efficiency of methylene blue (MB) went up from 81.4% in dark to 90.4% in light in the case of iron loading of 0.5 g/100 mL, persulfate (PS) concentration of 0.1 mM, MB concentration of 10 mg/L and pH 7. The uppermost degradation efficiency of MB was accomplished at pH 3 and the raising of PS concentration above 0.25 mM reduced the removal efficacy of MB. The degradation percentage of MB declined in the case of iron loading higher than 1.0 g/100 mL. The degradation rates of MB decreased with the rise of initial MB concentration. The degradation efficiencies of MB were 68.8%, 67.3%, 64.3%, 63% and 60% in five consecutive runs and the degradation efficiencies of pharmaceutical wastewater were 36.55%, 35.69%, 34.24%, 33.4% and 32% using the iron coated plates. The degradation ratios of agrochemical wastewater were 40.76%, 38.6%, 37.5%, 36.1% and 34.98%, whereas they were 23.7%, 22.35%, 22.03%, 21.23% and 20.03% in the case of petrochemical wastewater in five successive runs using the immobilized plates.

Abstract: The paper considers the implementation of magnetic-abrasive finishing in the conditions of digital technologies, in particular within CNC systems. The process was implemented through the development of a special device for MAF based on vertical processing center with CNC – Emco Concept Mill 250 and the definition of the combination of working motions of a billet in the interpole space of a magnetic system and their speeds. The result of the study are optimal combinations of working motions and their speeds taking into account formed surface roughness and processing efficiency.

Abstract: In the current era where pesticides play a vital role in one’s everyday life, large quantities of various pesticides some of which are highly toxic are being used routinely by industries and consumers. Extensive use of these chemicals provides greater risk to plants, animals and human population which has been reviewed from time to time. Apart from the biological degradation, photochemical removal holds considerable promise for the abatement of these pesticides in wastewaters. This paper reviews the photochemical degradation of pesticides. It is evident from the review that removal depends on several factors such as pH of the solution, catalysts loading, initial concentration of the pesticides, support based catalysts or suspended catalysts, light intensity and so on and so forth. Since the pesticides are ubiquitously present in the wastewaters, photochemical technology seems imperative to alleviate the pollution problems associated with the pesticides. However, commercial application of this technology has to be clearly assessed.

Abstract: The Friction Stir Welding FSW is a welding process in the solid state to join metallic alloys that is used in many industrial applications such as aerospace, automotive and shipbuilding. The process parameters such as the geometry of the tool, the speed of rotation and the speed of advance play a major role in determining the weld quality. In this work, an attempt was made to establish a relationship between the properties of the base material and FSW process parameters. Welds were made using AA1050 Aluminum alloy with different combination of parameters. Metallographic analysis was performed to verify the (faulty or fault-free) weld quality. Tests microhardness, tensile and bending were carried out to study the changes in the mechanical properties in the weld zone.

Abstract: The Proton Exchange Membrane (PEM) Fuel Cell performance not only depends on the operating parameters like temperature, pressure, the stoichiometric ratio of reactants, relative humidity and back pressure on anode and cathode flow channels, but it also depends on design parameters like channel width to rib width, channel depth and number of passes on the flow channel. In this paper numerical analysis were carried out with six different cross-sections of the channel, namely square, triangle, parallelogram 14^o, parallelogram 26^o, trapezium and inverted trapezium of 1.25 cm² active area with a constant cross sectional area of 0.01 cm² of single pass PEM fuel cell. The model was created and simulated under various pressures and temperature with a constant mass flow rate by using fluent CFD and the influence of the single pass flow channel on the performance of PEM fuel cell has been investigated.

Abstract: The paper uses computational fluid dynamics software FLUENT to build a single-channel numerical simulation model of the mine ventilation gas Thermal Flow-Reversal Reactor (TFRR). Combining with the analysis of orthogonal test, the influences that four factors (Initial temperature distribution, Ventilation gas flow velocity, Volume fraction of methane, Exchange period) act on reactor performance is investigated. An optimal operation condition is proposed by the establishment of the priority sequence of these four factors.

Abstract: In the current study, wear and frictional performances of different metals are investigated under different operating parameters against stainless steel counterface under dry contact conditions. The experiments performed using block on ring machine. Microscopy was used to examine the damage features on the worn surface and categorize the wear mechanism. Thermal imager was used to understand the thermal loading in the interface during the rubbing process. The results revealed that the operating parameters influence the wear and frictional behaviour of all the metals. Brass metal exhibited better wear and frictional behaviour compared to others. Three different wear mechanisms were observed, i.e. two body abrasion (Brass), three body abrasion (Aluminium) and adhesive (Mild Steel).

Abstract: Frequency and severity of some extreme weather events are increasing, and weather can impact the power system and its components in a number of ways. This paper identifies key technical issues facing the electric power industry, related to global climate change. The technical challenges arise from: 1) impacts on supply and demand balance; 2) impacts on system operating strategies, and power generation scheduling; 3) impacts on power grid structure, and power infrastructure response to extreme weather events; and 4) impacts on operation parameters of power system. The objective of this paper is to facilitate continued discussion of power systemclimate change interactions. To this end, this paper identifies key issues relating to the interactions between the electric power industry and global climate change. These issues will not be resolved quickly, and it requires sustained attention if they are to be resolved successfully.

Abstract: Experimental works carried out in recent years have demonstrated the feasibility of detecting a bearing fault through the spectral analysis of the Instantaneous Angular Speed (IAS) in the angular domain. Since these works have been carried out on complex mechanical systems (automotive gearboxes, vehicle wheels, wind turbines), neither the influence of operating parameters, nor the influence of structural parameters over the observed angular speed variations have been clearly identified. However, the implementation of effective tools for condition monitoring prospects requires a deep understanding of these interactions. In this regard, a test bench has been designed to allow defective bearing monitoring through IAS observation of a simple shaft running under varying loads and speeds, the system being simple enough to be easily described in various kind of mechanical or phenomenological models. The aim of this paper is to present a better understanding of the relationships between the speed variation induced by the monitored fault, the structural response and the observed phenomena. In the first part results obtained for a healthy bearing will be analyzed. These initial results serve as a reference for analysis of the results obtained with bearing defects. Coupled with dynamic modeling, they will also highlight the existence of a low frequency torsion mode. The results of this first part also highlight the wider interest of the IAS analysis for the study of rotating systems. In a second part, the measurements are performed with bearings having spalling type defects on their outer ring. The aim of this section is to estimate the influence of operating conditions on IAS monitored indicators. All these results will provide further phenomenological explanations of coupling between bearing fault and rotating speed.

Abstract: As the background of hydrological and geological conditions in Lu Xin Mine of Xinwen Mining Group, the transient electromagnetic instrument was used to detect the distribution law of aquifer around the first district. The detection results show that the roof and floor of 13# coal seam and the top of Jurassic are relatively rich in water, but the hydraulic connection between the upper and lower is relatively weak. The roof and floor of 6# and 9# coal seam and the bottom of Neogene are rich in water and the hydraulic connection is strength, and this place is located in the edge of basin which is easy for groundwater to supply.