Search results for: fine suspended sediments

Authors: Fatima S. Mohammed, Derrick Crump

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Harmattan, a dusty weather condition characterized by thick smog-like suspended particles and dust storm are the peculiar events that happen during ¾ of the year in the Sahelian regions including Damaturu Town, Nigeria), resulting in heavy dust deposits especially indoors. The inhabitants of the Damaturu community are always inflicted with different ailments; respiratory tract infections, asthma, gastrointestinal infections and different ailments associated with the dusty nature of the immediate environment. This brought the need to investigate the nature of the settled indoor dust. Vacuum cleaner bag dust was collected from indoor of some Nigerian and UK homes, as well as outdoors including during seasonal dusty weather event (Harmattan and Storm dust). The dust was sieved, and the (150 µm size) particles were examined using scanning electron microscope (SEM). The physical characterization of the settled dust samples has revealed the various shapes and sizes, and elemental composition of the dust samples is indicating that some of the dust fractions were the respirable fractions and also the dust contained PM10 to PM 2.5 fractions with possible health effects. The elemental compositions were indicative of the diverse nature of the dust particle sources, which showed dust as a complex matrix.

Keywords: indoor dust, Harmattan dust, SEM, health effects

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Authors: Majid Eslami

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Functionally graded materials (FGMs) exhibit heterogeneous microstructures in which the composition and properties gently change in specified directions. The common type of FGMs consist of a metal in which ceramic particles are distributed with a graded concentration. There are many processing routes for FGMs. An important group of these methods is casting techniques (gravity or centrifugal). However, the main problem of casting molten metal slurry with dispersed ceramic particles is a destructive chemical reaction between these two phases which deteriorates the properties of the materials. In order to overcome this problem, in the present investigation a suspension of 6061 aluminum and alumina powders in a liquid polymer was used as the starting material and subjected to centrifugal force for making FGMs. The size rang of these powders was 45-63 and 106-125 μm. The volume percent of alumina in the Al/Al2O3 powder mixture was in the range of 5 to 20%. PMMA (Plexiglas) in different concentrations (20-50 g/lit) was dissolved in toluene and used as the suspension liquid. The glass mold contaning the suspension of Al/Al2O3 powders in the mentioned liquid was rotated at 1700 rpm for different times (4-40 min) while the arm length was kept constant (10 cm) for all the experiments. After curing the polymer, burning out the binder, cold pressing and sintering , cylindrical samples (φ=22 mm h=20 mm) were produced. The density of samples before and after sintering was quantified by Archimedes method. The results indicated that by using the same sized alumina and aluminum powders particles, FGM sample can be produced by rotation times exceeding 7 min. However, by using coarse alumina and fine alumina powders the sample exhibits step concentration. On the other hand, using fine alumina and coarse alumina results in a relatively uniform concentration of Al2O3 along the sample height. These results are attributed to the effects of size and density of different powders on the centrifugal force induced on the powders during rotation. The PMMA concentration and the vol.% of alumina in the suspension did not have any considerable effect on the distribution of alumina particles in the samples. The hardness profiles along the height of samples were affected by both the alumina vol.% and porosity content. The presence of alumina particles increased the hardness while increased porosity reduced the hardness. Therefore, the hardness values did not show the expected gradient in same sample. The sintering resulted in decreased porosity for all the samples investigated.

Keywords: FGM, powder metallurgy, centrifugal method, polymeric suspension

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Authors: Guohua Tu, Zhi Fu, Zhiwei Hu, Neil D Sandham, Jianqiang Chen

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Tripping of boundary-layers from laminar to turbulent flow, which may be necessary in specific practical applications, requires high amplitude disturbances to be introduced into the boundary layers without large drag penalties. As a possible improvement on fixed trip devices, a technique based on vortex shedding for enhancing supersonic flow transition is demonstrated in the present paper for a Mach 1.5 boundary layer. The compressible Navier-Stokes equations are solved directly using a high-order (fifth-order in space and third-order in time) finite difference method for small-scale cylinders suspended transversely near the wall. For cylinders with proper diameter and mount location, asymmetry vortices shed within the boundary layer are capable of tripping laminar-turbulent transition. Full three-dimensional simulations showed that transition was enhanced. A parametric study of the size and mounting location of the cylinder is carried out to identify the most effective setup. It is also found that the vortex shedding can be suppressed by some factors such as wall effect.

Keywords: boundary layer instability, boundary layer transition, vortex shedding, supersonic flows, flow control

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Authors: D. Naresh Yadav, K. Anand Kishore, Bhaskar Bethi, Shirish H. Sonawane, D. Bhagawan

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The untreated industrial wastewater discharged into the environment causes the contamination of soil, water and air. Advanced treatment methods for enhanced wastewater treatment are attracting substantial interest among the currently employed unit processes in wastewater treatment. The textile industry is one of the predominant in wastewater production at current industrialized situation. The refused dyes at textile industry need to be treated in proper manner before its discharge into water bodies. In the present investigation, hybrid treatment process has been developed for the treatment of synthetic mixed dye wastewater. Photocatalysis and ceramic nanoporous membrane are mainly used for process integration to minimize the fouling and increase the flux. Commercial semiconducting powders (TiO2 and ZnO) has used as a nano photocatalyst for the degradation of mixed dye in the hybrid system. Commercial ceramic nanoporous tubular membranes have been used for the rejection of dye and suspended catalysts. Photocatalysis with catalyst has shown the average of 34% of decolorization (RB-32%, BG-34% and CR-36%), whereas ceramic nanofiltration has shown the 56% (RB-54%, BG-56% and CR-58%) of decolorization. Integration of photocatalysis and ceramic nanofiltration has shown 96% (RB-94%, BG-96% and CR-98%) of dye decolorization over 90 min of operation.

Keywords: photocatalysis, ceramic nanoporous membrane, wastewater treatment, advanced oxidation process, process integration

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Authors: Shinji Kajiwara, Tadamasa Fukuoka

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The formula project of Kinki University has been involved in the student Formula SAE of Japan (JSAE) since the second year the competition was held. The vehicle developed in the project uses a ZX-6R engine, which has been manufactured by Kawasaki Heavy Industries for the JSAE competition for the eighth time. The limited performance of the concept vehicle was improved through the development of a power train. The supercharger loading, engine dry sump, and engine cooling management of the vehicle were also enhanced. The supercharger loading enabled the vehicle to achieve a maximum output of 59.6 kW (80.6 PS)/9000 rpm and a maximum torque of 70.6 Nm (7.2 kgf m)/8000 rpm. We successfully achieved 90% of the engine’s torque band (4000–10000 rpm) with 50% of the revolutions in regular engine use (2000–12000 rpm). Using a dry sump system, we periodically managed hydraulic pressure during engine operation. A system that controls engine stoppage when hydraulic pressure falls was also constructed. Using the dry sump system at 80 mm reduced the required engine load and the vehicle’s center of gravity. Even when engine motion was suspended by the electromotive force exerted by the water pump, the circulation of cooling water was still possible. These findings enabled us to create a cooling system in accordance with the requirements of the competition.

Keywords: engine, combustion, cooling system, numerical simulation, power, torque, mechanical super charger

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Authors: Miladi Yasmine, Bouhlel Salah, Garnit Hechmi, David Banks

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The Jebel Mecella F (Ba-Pb-Zn) ore deposits of the Zaghouan district are located in northeastern Tunisia, 60 km south of Tunis. The host rocks belong to the Ressas Formation of Kimmeridgian-Tithonian age and lower Cretaceous layers. Mineralisations occur as stratiform lenses and fracture fillings. The ore mineral assemblage is composed of fluorite, barite, sphalerite galena, and quartz. Primary fluid inclusions in sphalerite have homogenization temperatures ranging from 129 to 145°C final melting temperature range from -14.9 to -10.0, corresponding to salinities of 14.0 to 17.7 wt% NaCl equivalent. Fluid inclusions in fluorite homogenize to the liquid phase between 116 and 160°C. The final ice melting temperature ranges from -23 to -15 °C, corresponding to salinities between 17 and 24 wt% NaCl equivalent. The LAICP-MS analyses of the fluid inclusions in fluorite show that these fluids are dominated by Na>K>Mg. Furthermore, the high K/Na values from fluid inclusions suggest the brine interacted with K-rich rocks in the basement or in siliciclastic sediments in the basins. The ore fluids in Jebel Mecella are highly saline and Na-K dominated with lower Mg concentrations, and come from the leaching of the dolomitic host rocks. These results are compatible with Mississippi-Valley-type mineralizing fluids.

Keywords: Jebel Mecella, fluid inclusions, micro thermometry, LA-ICP-MS

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Authors: Otana A. Jakpor

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Air pollution is without a doubt one of the gravest environmental threats the world is facing today in terms of its sheer toll on human lives. Each year an estimated 70,000 Americans lose their lives to air pollution -- a number equal to deaths from both breast and prostate cancer combined. Since Americans spend nearly 90% of their time indoors, more research is needed on indoor air pollution and common exposures such as candles. Paraffin wax is a by-product of petroleum, and similarities have been observed between fine particulate emissions from paraffin candles and diesel exhaust. The purpose of this study is to determine whether or not paraffin candles are a major potential source of indoor air pollution. Furthermore, this study aims to determine whether or not soy candles are a safer, cleaner alternative to paraffin candles.

Keywords: soy candle, soy, paraffin candle, paraffin

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Authors: Dharminer Singh, Sanjeev Yadav, Pravakar Mohanty

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In this work, gasification of groundnut shell was carried out in an air bubbling fluidized bed gasifier. Atmospheric air used as gasification agent in the gasifier. The groundnut shell used for gasification was in powder form and the locally available river sand was used as bed material. Conventional charcoal was used for heating sand bed. Two cyclones were used for proper segregation of char particles and for proper cleaning and cooling the product gas. Experiments were performed on different equivalence ratio (ER) 0.3 - 0.33 by varying feeding rate 36 - 32.8 kg/h of biomass and by keeping the air flow rate constant at bed temperature between 700 °C – 800 °C. Performance of gasifier was evaluated on the basis of different parameters such as cold gas efficiency, carbon conversion efficiency (CCE), Tar and Suspended particles matter (SPM) generation, gas yield, and Higher heating value (HHV) of gas. The optimal ER value for gasification of groundnut shell (GNS) powder in an air bubbling fluidized bed gasifier was found to be 0.31. Cold gas efficiency and CCE value at optimal ER was found to be 63.7 %, and 91 %, respectively. Concentration of Tar and SPM, HHV of gas, and gas yield at optimal ER was found to be 11.88 g/Nm3, 2.38 MJ/Nm3, and 2.01m3/kg, respectively. In the product gas, concentrations of CO, CO2, CH4 and H2 were found to be 12.94%, 13.5%, 5.74% and 13.77%, respectively. At ER 0.31, it was observed that bed temperature of gasifier was in steady state for long time at 714 °C with 5 – 10 °C fluctuation.

Keywords: air bubbling fluidized bed gasifier, groundnut shell powder, equivalence ratio (ER), cold gas efficiency, carbon conversion efficiency (CCE), high heating value (HHV)

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Authors: Ali Mashinchian Moradi, Mahmood Sinaei

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Study on the biomarkers to assess health status of marine ecosystems has an important value in biomonitoring of marine environment. Accordingly, accumulation of polycyclic aromatic hydrocarbons in sediment, water and tissues (liver and gill) of mudskipper (Boleophthalmus dussmieri) and some physiological responses like lysosomal membrane change in haemocytes and the Glutathione-S Transferase (GST) activity in the liver were measured in mudskippers. Samples were collected from five sites along the noth western cost of the Persian Gulf. PAHs concentration was measured by HPLC method. The activity of GST enzyme was analysed by spectrophotometric method. Total PAH concentration in coastal seawater, sediments, liver and gill tissues ranged between 0.80-18.34 ug/L, 113.550-3384.34 ng/g dw, 3.99-46.64 ng/g dw and 3.11-17.This study showed that PAH concentrations in this region are not higher than available standards. The findings revile that lysosomal membrane destabilization and liver GST activities are highly sensitive to PAHs in mudskipper, B. dussumieri. Sediment PAH concentrations were strongly correlated with biomarkers, indicating PAHs were biologically available to fish. Thus, mudskipper perceived to be good sentinel organism for PAH pollution biomonitoring.

Keywords: PAHs, biomarker, mudskipper, Persian Gulf

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Authors: Li Long, Thomas Ortlepp

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A theoretical model for the optimization of thermopile sensor performance is developed for thermoelectric-based infrared radiation detection. It is shown that the performance of polycrystalline silicon film thermopile sensor can be optimized according to the thermoelectric quality factor, sensor layer structure factor, and sensor layout geometrical form factor. Based on the properties of electrons, phonons, grain boundaries, and their interactions, the thermoelectric quality factor of polycrystalline silicon is analyzed with the relaxation time approximation of the Boltzmann transport equation. The model includes the effect of grain structure, grain boundary trap properties, and doping concentration. The layer structure factor is analyzed with respect to the infrared absorption coefficient. The optimization of layout design is characterized by the form factor, which is calculated for different sensor designs. A double-layer polycrystalline silicon thermopile infrared sensor on a suspended membrane has been designed and fabricated with a CMOS-compatible process. The theoretical approach is confirmed by measurement results.

Keywords: polycrystalline silicon, relaxation time approximation, specific detectivity, thermal conductivity, thermopile infrared sensor

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Authors: Sangram Shamrao Patil, Hara Mohan Jena

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Phthalates are among the most common organic pollutant since they have become widespread in the environment and found in sediments, natural waters, soils, plants, landfill leachates, biota including human tissue and aquatic organisms. Diethyl phthalate (DEP) is a low molecular weight phthalate which has wide applications as plasticizer and become a major cause of environmental pollution. Environmental protection agency (EPA) listed DEP as priority pollutant because of its toxicity and they recommended human health ambient water quality criterion for diethyl phthalate (DEP) as 4 mg/l. Therefore, wastes containing phthalates require proper treatment before being discharged into the environment. Biodegradation is attractive and efficient treatment method as it is cost effective and produces non-toxic end products. In the present study, a DEP degrading aerobic bacterium was isolated from soil contaminated with plastic industry wastewater. Morphological and biochemical characteristics of isolate were performed. 16S rRNA sequencing and phylogenetic analysis of isolate was carried out and it was identified as Empedobacter brevis. Isolate has been found to tolerate up to 1650 mg/l of DEP. This study will be significant for exploring an application of microbes for remediation of phthalates and development of a suitable bioreactor.

Keywords: diethyl phthalate, plasticizer, pollutant, biodegradation

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Authors: Andrzej Mitura, Krzysztof Kecik, Michal Augustyniak

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This paper presents a numerical and experimental research of a nonlinear two degrees of freedom system. The tested system consists of a mechanical oscillator (the primary subsystem) with the attached pendulum (the secondary subsystem). The oscillator is suspended on a linear (or nonlinear) coil spring and a nonlinear magnetorheorogical damper and it is excited kinematically. Added pendulum can be used to reduce vibration of a primary subsystem or to energy harvesting. The numerical and experimental investigations showed that the pendulum can perform several types of motion, for example: chaotic motion, constant position in lower or upper (stable inverted pendulum), rotation, symmetrical or asymmetrical swinging vibrations. The main objective of this study is to determine an influence of system parameters for increasing the zone when the pendulum rotates. As a final effect a semi-active control method to change the pendulum solution on the rotation is proposed. To the implementation of this method the magnetorheorogical damper is applied. Continuous rotation of the pendulum is desirable for recovery of energy. The work is financed by Grant no. 0234/IP2/2011/71 from the Polish Ministry of Science and Higher Education in years 2012-2014.

Keywords: autoparametric vibrations, chaos and rotation control, magnetorheological damper

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Authors: Aicha Assal, El Mostapha Lotfi

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According to data from the Directorate General of Meteorology (DGM), the average amount of precipitation recorded nationwide between September 1, 2021, and January 31, 2022, is 38.8 millimeters. This is well below the climatological normal of 106.8 millimeters for the same period between 1981 and 2010. This situation is becoming increasingly worrying, particularly for farmers who are finding it difficult to irrigate their land and feed their livestock. Drought is greatly influenced by the effects of climate change, mainly caused by pollution and greenhouse gases (GHGs). The aim of this work is to contribute to the purification of wastewater (considered as polluting) in order to reuse it for irrigation in agricultural areas or for livestock watering. This will be achieved once physico-chemical treatment tests on these waters have been carried out and validated. The main parameters analyzed in this study, after carrying out discoloration tests on domestic wastewater, include COD (chemical oxygen demand), BOD5 (biochemical oxygen demand), pH, conductivity, dissolved oxygen, suspended solids (SS), phosphate, nitrate, nitrite and ammonium ions, faecal and total coliforms, as well as monitoring heavy metal concentrations. This work is also aimed at reclaiming the sludge produced by the decantation process, which will enable the waste to be transformed and reused as compost in agriculture and gardening.

Keywords: wastewater, irrigation, COD, COB, SS

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Authors: Sílvia tuyà Viñas, Bruno Fernández-Valdés, Carla Pérez-Chirinos, Monica Morral-Yepes, Lucas del Campo Montoliu, Gerard Moras Feliu

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Some researchers stated that whole body vibration (WBV) generates postural destabilization, although there is no extensive research. Therefore, the aim of this study was to analyze movement variability when performing a half-squat with a different type of ballasts and rhythms with (V) and without (NV) WBV in male athletes using entropy. Twelve experienced in strength training males (age: 21.24  2.35 years, height: 176.83  5.80 cm, body mass: 70.63  8.58 kg) performed a half-squat with weighted vest (WV), dumbbells (D), and a bar with the weights suspended with elastic bands (B), in V and NV at 40 bpm and 60 bpm. Subjects performed one set of twelve repetitions of each situation, composed by the combination of the three factors. The movement variability was analyzed by calculating the Sample Entropy (SampEn) of the total acceleration signal recorded at the waist. In V, significant differences were found between D and WV (p<0.001; ES: 2.87 at 40 bpm; p<0.001; ES: 3.17 at 60 bpm) and between the B and WV at both rhythms (p<0.001; ES: 3.12 at 40 bpm; p<0.001; ES: 2.93 at 60 bpm) and a higher SampEn was obtained at 40 bpm with all ballasts (p<0.001; ES of WV: 1.22; ES of D: 4.49; ES of B: 4.03). No significant differences were found in NV. WBV is a disturbing and destabilizing stimulus. Strength and conditioning coaches should choose the combination of ballast and rhythm of execution according to the level and objectives of each athlete.

Keywords: accelerometry, destabilization, entropy, movement variability, resistance training

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Authors: Chih-Jer Lin, Chun-Ying Lee, Ying Liu, Chiang-Ho Cheng

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The main objective of this article is to present the semi-active vibration control using an electro-rheological fluid embedded sandwich structure for a cantilever beam. ER fluid is a smart material, which cause the suspended particles polarize and connect each other to form chain. The stiffness and damping coefficients of the ER fluid can be changed in 10 micro seconds; therefore, ERF is suitable to become the material embedded in the tunable vibration absorber to become a smart absorber. For the ERF smart material embedded structure, the fuzzy control law depends on the experimental expert database and the proposed self-tuning strategy. The electric field is controlled by a CRIO embedded system to implement the real application. This study investigates the different performances using the Type-1 fuzzy and interval Type-2 fuzzy controllers. The Interval type-2 fuzzy control is used to improve the modeling uncertainties for this ERF embedded shock absorber. The self-tuning vibration controllers using Type-1 and Interval Type-2 fuzzy law are implemented to the shock absorber system. Based on the resulting performance, Internal Type-2 fuzzy is better than the traditional Type-1 fuzzy control for this vibration control system.

Keywords: electro-rheological fluid, semi-active vibration control, shock absorber, type 2 fuzzy control

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Authors: Faraj M. Elkhatri, Hana Ali Allafi

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The spatial and temporal distribution of diagenetic alterations related impact on the reservoir quality of the Sarir Formation. (present day burial depth of about 9000 feet) Depositional facies and diagenetic alterations are the main controls on reservoir quality of Sarir Formation Sirt Ba-sin Libya; these based on lithology and grain size as well as authigenic clay mineral types and their distributions. However, petrology investigation obtained on study area with five sandstone wells concentrated on main rock components and the parameters that may have impacts on reservoirs. the main authigenic clay minerals are kaolinite and dickite, these investigations have confirmed by X.R.D analysis and clay fraction. mainly Kaolinite and Dickite were extensively presented on all of wells with high amounts. As well as trace of detrital smectite and less amounts of illitized mud-matrix are possibly find by SEM image. Thin layers of clay presented as clay-grain coatings in local depth interpreted as remains of dissolved clay matrix is partly transformed into kaolinite adjacent and towards pore throat. This also may have impacts on most of the pore throats of this sandstone which are open and relatively clean with some of fine martial have been formed on occluded pores. This material is identified by EDS analysis to be collections of not only kaolinite booklets, but also small, disaggregated kaolinite platelets derived from the dis-aggregation of larger kaolinite booklets. These patches of kaolinite not only fill this pore, but also coat some of the sur-rounding framework grains. Quartz grains often enlarged by authigenic quartz overgrowths partially occlude and re-duce porosity. Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM) was conducted on the post-test samples to examine any mud filtrate particles that may be in the pore throats. Semi-qualitative elemental data on select-ed minerals observed during the SEM study were obtained using an Energy Dispersive Spectroscopy (EDS) unit. The samples showed mostly clean open pore throats, with limited occlusion by kaolinite.

Keywords: por throat, formation damage, porosity lose, solids plugging

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Authors: Zhijun Ren, Zhang Lin, Zhao Ye, Zuo Xiangyu, Mei Dongxing

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As a pretreatment process of ballast water treatment, the performance of high gradient magnetic separation (HGMS) technology for the removal of particulates and microorganisms was studied. The results showed that HGMS process could effectively remove suspended particles larger than 5 µm and had ability to resist impact load. Microorganism could also be effectively removed by HGMS process, and the removal effect increased with increasing magnetic field strength. The maximum removal rates for Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were 4016.1% and 9675.3% higher, respectively, than without the magnetic field. In addition, the superoxide dismutase (SOD) activity of the microbes decreased by 32.2% when the magnetic field strength was 15.4 mT for 72 min. The microstructure of the stainless steel wool was investigated, and the results showed that particle removal by HGMS has common function by the magnetic force of the high-strength, high-gradient magnetic field on weakly magnetic particles in the water, and on the stainless steel wool.

Keywords: HGMS, particulates, superoxide dismutase (SOD) activity, steel wool magnetic medium

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Authors: Prudhvinath Reddy Ankireddy, Narasimha Mangadoddy

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Spiral concentrators are commonly used in various industries, including mineral and coal processing, to efficiently separate materials based on their density and size. In these concentrators, a mixture of solid particles and fluid (usually water) is introduced as feed at the top of a spiral channel. As the mixture flows down the spiral, centrifugal and gravitational forces act on the particles, causing them to stratify based on their density and size. Spiral flows exhibit complex fluid dynamics, and interactions involve multiple phases and components in the process. Understanding the behavior of these phases within the spiral concentrator is crucial for achieving efficient separation. An experimental bi-component particle interaction study is conducted in this work utilizing magnetite (heavier density) and silica (lighter density) with different proportions processed in the spiral concentrator. The observation separation reveals that denser particles accumulate towards the inner region of the spiral trough, while a significant concentration of lighter particles are found close to the outer edge. The 5th turn of the spiral trough is partitioned into five zones to achieve a comprehensive distribution analysis of bicomponent particle segregation. Samples are then gathered from these individual streams using an in-house sample collector, and subsequent analysis is conducted to assess component segregation. Along the trough, there was a decline in the concentration of coarser particles, accompanied by an increase in the concentration of lighter particles. The segregation pattern indicates that the heavier coarse component accumulates in the inner zone, whereas the lighter fine component collects in the outer zone. The middle zone primarily consists of heavier fine particles and lighter coarse particles. The zone-wise results reveal that there is a significant fraction of segregation occurs in inner and middle zones. Finer magnetite and silica particles predominantly accumulate in outer zones with the smallest fraction of segregation. Additionally, numerical simulations are also carried out using the computational fluid dynamics (CFD) model based on the volume of fluid (VOF) approach incorporating the RSM turbulence model. The discrete phase model (DPM) is employed for particle tracking, thereby understanding the particle segregation of magnetite and silica along the spiral trough.

Keywords: spiral concentrator, bi-component particle segregation, computational fluid dynamics, discrete phase model

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Authors: Reza Salehi, Peter L. Dold, Yves Comeau

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The aim of the present study was to investigate the effect of a total of 6 operating parameters including pH (X1), temperature (X2), stirring speed (X3), chemical oxygen demand (COD) (X4), volatile suspended solids (VSS) (X5) and time (X6) on anaerobic orthophosphate release from enhanced biological phosphorus removal (EBPR) sludge. An 8-run Plackett Burman design was applied and the statistical analysis of the experimental data was performed using Minitab16.2.4 software package. The Analysis of variance (ANOVA) results revealed that temperature, COD, VSS and time had a significant effect with p-values of less than 0.05 whereas pH and stirring speed were identified as non-significant parameters, but influenced orthophosphate release from the EBPR sludge. The mathematic expression obtained by the first-order multiple linear regression model between orthophosphate release from the EBPR sludge (Y) and the operating parameters (X1-X6) was Y=18.59+1.16X1-3.11X2-0.81X3+3.79X4+9.89X5+4.01X6. The model p-value and coefficient of determination (R2) value were 0.026 and of 99.87%, respectively, which indicates the model is significant and the predicted values of orthophosphate release from the EBPR sludge have been excellently correlated with the observed values.

Keywords: anaerobic, operating parameters, orthophosphate release, Plackett-Burman design

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Authors: Motonori Tamura

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Ceramics coatings consisting of fine crystal grains, with diameters of about 100 nm or less, provided superior hydrogen-permeation barriers. Applying TiN, TiC or Al₂O₃ coatings on a stainless steel substrate reduced the hydrogen permeation by a factor of about 100 to 5,000 compared with uncoated substrates. Effect of the microstructure of coatings on hydrogen-permeation behavior is studied. The test specimens coated with coatings, with columnar crystals grown vertically on the substrate, tended to exhibit higher hydrogen permeability. The grain boundaries of the coatings became trap sites for hydrogen, and microcrystalline structures with many grain boundaries are expected to provide effective hydrogen-barrier performance.

Keywords: hydrogen permeation, tin coating, microstructure, crystal grain, stainless steel

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Authors: Vasilii V. Ananev

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Oil-and-gas potential of Cuba is found through the discoveries among which there are the most large-scale deposits, such as the Boca de Jaruco and Varadero fields of heavy oils. Currently, the petroleum and petroleum products needs of the island state are satisfied by own sources by less than a half. The prospects of the hydrocarbon resource base development are connected with the adjacent water area of the Gulf of Mexico where foreign companies had been granted license blocks for geological study and further development since 2001. Two Russian companies - JSC Gazprom Neft and OJSC Zarubezhneft, among others, took part in the development of the Cuban part of the Gulf of Mexico. Since 2004, five oil wells have been drilled by various companies in the deep waters of the exclusive economic zone of Cuba. Commercial oil-and-gas bearing prospects have been established in neither of them for both geological and technological reasons. However, only a small part of the water area has been covered by drilling and the productivity of the drill core has been tested at the depth of Cretaceous sediments only. In our opinion, oil-and-gas bearing prospects of the exclusive economic zone of the Republic of Cuba in the Gulf of Mexico remain undervalued and the mentioned water area needs additional geological exploration. The planning of exploration work in this poorly explored region shall be carried out systematically and it shall be based on the results of the regional scientific research.

Keywords: Cuba, catoche, geology, exploration

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Authors: Fiasal Assiri, Joanna Wincenciak, David Morrison-Love

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With the rapid spread of the COVID-19 pandemic, the Saudi government suspended students from going to school to combat the outbreak. As e-learning was not applied at all in schools, online teaching and learning have been revived in Saudi Arabia by providing a new platform called ‘Madrasati.’ Several studies have used the Decomposed Theory of Planned Behaviour (DTPB)to examineindividuals’ intention behavior in many fields. However, there is a lack of studies investigating the determinants of teachers’ continued intention touseMadrasati platform. The purpose of this paper is to present a conceptual model in light of DTPB. To enhance the predictability of the model, the study incorporates other variables, including learning content quality and interactivity as sub-factors under the perceived usefulness, students and government influences under the subjective norms, and technical support and prior e-learning experience under the perceived behavioral control. The model will be further validated using a mixed methods approach. Such findings would help administrators and stakeholders to understand teachers’ needs and develop new methods that might encourage teachers to continue using Madrasati effectively in their teaching.

Keywords: madrasati, decomposed theory of planned behaviour, continuance intention, attitude, subjective norms, perceived behavioural control

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Authors: Monika Gałwa-Widera, Anna Kwarciak–Kozłowska, Lucyna Sławik-Dembiczak

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Issues relating to management of sewage sludge from small and medium-sized wastewater treatment plants is a vital issue, which deal with such scholars as well as those directly involved in the issue of wastewater treatment and management of sedimentary. According to the Law on Waste generating waste is responsible for such processing to the product obtained impacted on the environment minimally. In small and medium-sized wastewater treatment plants have to deal with the technology of sludge management technology is far from drying and incineration of sewage sludge. So here you can use other technologies. One of them is the composting of sewage sludge. It is a process of processing and disposal of sewage sludge that effectively their disposal. By composting, we can obtain a product that contains significant amounts of organic matter to assess the fertilizing qualities. Modifications to the ongoing process in biological reactors allow for more rapid receipt of a wholesome product. The research presented and discussed in this publication relate to assist the composting process of sewage sludge and biomass structural material in the shares of rates: 35% biomass, 55% sludge, 10% structural material using a method which involves the re-spawning batch composting physical methods leachate from the composting process.

Keywords: biomass, composting, industry, sewage sludge

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Authors: M. O. Eyankware, D. O. Ufomata

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Groundwater samples were collected from Otovwodo-Ughelli and Environ with the aim of assessing groundwater quality of the area. Twenty (20) water samples from Boreholes (BH) (six) and Hand Dug Wells (HDW) (fourteen) were randomly sampled and were analysed for different physiochemical and bacteriological parameters. The following 16 parameters have been considered viz: pH, electrical conductivity, temperature, total hardness, total dissolved solids, dissolved oxygen, biological oxygen demand, phosphate, sulphate, chloride, nitrate, calcium, sodium, chloride, magnesium, and total suspended solids. On comparing the results against drinking quality standards laid by World Health Organization and Nigeria industrial standard, it was found that the water quality parameters were not above the (WHO, 2011 and NIS, 2007) permissible limit. Microbial analysis reveals the presence of coliform and E.coli in two hand-dug well (HDW7 and 13) and one borehole well (BH20). These contaminations are perhaps traceable to have originated from human activities (septic tanks, latrines, dumpsites) and have affected the quality of groundwater in Otovwodo-Ughelli. From the piper trilinear diagram, the dominant ionic species is alkali bicarbonate water type, with bicarbonate as the predominant ion (Na+ + K+)-HCO3.

Keywords: groundwater, surface water, Ughelli, Nigeria industrial standard, who standard

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Authors: Olayinka Oduwole, Steve Sheard

Abstract:

The magnetic separation of biological cells using super-magnetic beads has been used widely for various bioassays. These bioassays can further be integrated with other laboratory components to form a biosensor which can be used for cell sorting, mixing, purification, transport, manipulation etc. These bio-sensing applications have also been facilitated by the wide availability of magnetic beads which range in size and magnetic properties produced by different manufacturers. In order to improve the efficiency and separation capabilities of these biosensors, it is important to determine the magnetic force induced velocities and interaction of beads within the magnetic field; this will help biosensor users choose the desired magnetic bead for their specific application. This study presents for the first time the interaction between a pair of different sized super-paramagnetic beads suspended in a static fluid moving within a uniform magnetic field using a modified finite-time-finite-difference scheme. A captured video was used to record the trajectory pattern and a good agreement was obtained between the simulated trajectories and the video data. The model is, therefore, a good approximation for predicting the velocities as well as the interaction between various magnetic particles which differ in size and magnetic properties for bio-sensing applications requiring a low concentration of magnetic beads.

Keywords: biosensor, magnetic field, magnetic separation, super-paramagnetic bead

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Authors: E. Moroydor Derun, N. Tugrul, N. Baran Acarali, A. S. Kipcak, S. Piskin

Abstract:

Fly ash is a waste material of coal firing thermal plants that is released from thermal power plants. It was defined as very fine particles that are drifted upward which are taken up by the flue gases. The emerging amount of fly ash in the world is approximately 600 million tons per year. In our country, it is expected that will be occurred 50 million tons of waste ash per year until 2020. The fly ashes can be evaluated by using as adsorbent material. The purpose of this study is to investigate the possibility of use of various fly ashes (Tuncbilek, Catalagzi, Orhaneli) like low-cost adsorbents for heavy metal adsorption. First of all, fly ashes were characterized. For this purpose; analyses such as XRD, XRF, SEM and FT-IR were performed.

Keywords: adsorbent, fly ash, heavy metal, waste

Procedia PDF Downloads 244

Authors: Pello Alfonso-Muniozguren, Madeleine Bussemaker, Devendra Saroj, Judy Lee

Abstract:

Wastewater treatment is becoming a worldwide concern due to new and tighter environmental regulations, and the increasing need for fresh water for the exponentially growing population. The meat industry has one of the highest consumption of water producing up to 10 times more polluted (BOD) wastewaters in comparison to domestic sewage. Therefore, suitable wastewater treatment methods are required to ensure the wastewater quality meet regulations before discharge. In the present study, a combined lab scale activated sludge-sonication system was used to treat pre-treated abattoir wastewater. A hydraulic retention time of 24 hours and a solid retention time of 13 days were used for the activated sludge process and using ultrasound as tertiary treatment. Different ultrasonic frequencies, powers and sonication times were applied to the samples and results were analysed for chemical oxygen demand (COD), biological oxygen demand (BOD), total suspended solids, pH, total coliforms and total viable counts. Additionally, both mechanical and chemical effects of ultrasound were quantified for organic matter removal (COD and BOD) and disinfection (microorganism inactivation) using different techniques such as aluminum foil pitting, flow cytometry, and KI dosimetry.

Keywords: abattoir wastewater, ultrasound, wastewater treatment, water disinfection

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Authors: Yalçın Kılıç, İbrahim Kani

Abstract:

The conversion of hydrocarbons to carbonyl compounds by oxidation reaction is one of the most important reactions in the synthesis of fine chemicals. As a result of the oxidation of hydrocarbons containing aliphatic sp3-CH groups in their structures, aldehydes, ketones or carboxylic acids can be obtained. In this study, OSSO-type 2,2'-[1,4-butanedylbis(thio)]bis-benzoic acid (tsabutH2) ligand and [Zn(µ-tsabut)(phen)]n complex (where phen = 1,10-phenantroline) were synthesized and their structures were characterized by single crystal x-ray diffraction method. The catalytic efficiency of the complex in the catalytic oxidation studies of organic compounds such as cyclohexane, ethylbenzene, diphenylmethane, and p-xylene containing sp3-C-H in its structure was investigated.

Keywords: metal complex, OSSO-type ligand, catalysis, oxidation

Procedia PDF Downloads 82

Authors: Mengying Wang, Xiaohui Wang, Chun Deng, Bei Liu, Changyu Sun, Guangjin Chen, Mahmoud El-Halwagi

Abstract:

Significant amounts of natural gas hydrates (NGHs) are considered potential new sustainable energy resources in the future. However, common used methods for methane gas recovery from hydrate sediments require high investment but with low gas production efficiency, and may cause potential environment and security problems. Therefore, there is a need for effective gas production from hydrates. The natural gas hydrate production method by CO₂/H₂ replacement coupling steam methane reforming can improve the replacement effect and reduce the cost of gas separation. This paper develops a simulation model of the gas production process integrated with steam reforming and membrane separation. The process parameters (i.e., reactor temperature, pressure, H₂O/CH₄ ratio) and the composition of CO₂ and H₂ in the feed gas are analyzed. Energy analysis is also conducted. Two design scenarios with different composition of CO₂ and H₂ in the feed gas are proposed and evaluated to assess the energy efficiency of the novel system. Results show that when the composition of CO₂ in the feed gas is between 43 % and 72 %, there is a certain composition that can meet the requirement that the flow rate of recycled gas is equal to that of feed gas, so as to ensure that the subsequent production process does not need to add feed gas or discharge recycled gas. The energy efficiency of the CO₂ in feed gas at 43 % and 72 % is greater than 1, and the energy efficiency is relatively higher when the CO₂ mole fraction in feed gas is 72 %.

Keywords: Gas production, hydrate, process integration, steam reforming

Procedia PDF Downloads 165

Authors: Han-Seul Lee, Min-Koo Kang, Sang-Ill Lee

Abstract:

This study was conducted to reduce runoff by rainwater infiltration facility using attached growth with Bacillus sp., which are reported to remove nitrogen and phosphorus, as well as organic matter effectively. This study was investigated non-point pollutants removal efficiency of organic, nitrogen, and phosphorus in column using the media attached growth with Bacillus sp. To compare attached growth with bacillus sp. and detached media, two columns filled with perlite, zeolite, vermiculite, pumice, peat-moss was installed. In A column (attached growth with bacillus sp.), in case of infiltration velocity 30 mm/hr in high concentration of influent, it showed the removal efficiency (after aging term) is SS (suspended solid) 85.8±1.2 %, T-P (total phosphorus) 67.0±8.1 %, T-N (total nitrogen) 66.0±4.9 %, COD (chemical oxygen demand) 73.6±2.9 %, NH4+-N 72.7±3.0 %. In B column (detached media), in case of infiltration velocity 30 mm/hr in high concentration of influent, it showed the removal efficiency (after aging term) is SS 86.0±2.2 %, T-P 62.5±11.3 %, T-N 53.3±3.9 %, COD 34.6±3.7 %, NH4+-N 61.5±2.8 %. Removal efficiency of A column is better than B column. As the result from this study, using media with Bacillus sp. can improve an effective removal of non-point source pollutants.

Keywords: non-point source pollutants, Bacillus sp., rainwater, infiltration facility

Procedia PDF Downloads 310