Search results for: limit pressure of soil

Authors: S. Lertsakulpasuk, S. Athichanagorn

Abstract:

As depletion-drive gas reservoirs are abandoned when there is insufficient production rate due to pressure depletion, waterflooding has been proposed to increase the reservoir pressure in order to prolong gas production. Due to high cost, water injection may not be economically feasible. Water dumpflood into gas reservoirs is a new promising approach to increase gas recovery by maintaining reservoir pressure with much cheaper costs than conventional waterflooding. Thus, a simulation study of water dumpflood into multiple nearly abandoned or already abandoned thin-bedded gas reservoirs commonly found in the Gulf of Thailand was conducted to demonstrate the advantage of the proposed method and to determine the most suitable operational parameters for reservoirs having different system parameters. A reservoir simulation model consisting of several thin-layered depletion-drive gas reservoirs and an overlying aquifer was constructed in order to investigate the performance of the proposed method. Two producers were initially used to produce gas from the reservoirs. One of them was later converted to a dumpflood well after gas production rate started to decline due to continuous reduction in reservoir pressure. The dumpflood well was used to flow water from the aquifer to increase pressure of the gas reservoir in order to drive gas towards producer. Two main operational parameters which are wellhead pressure of producer and the time to start water dumpflood were investigated to optimize gas recovery for various systems having different gas reservoir dip angles, well spacings, aquifer sizes, and aquifer depths. This simulation study found that water dumpflood can increase gas recovery up to 12% of OGIP depending on operational conditions and system parameters. For the systems having a large aquifer and large distance between wells, it is best to start water dumpflood when the gas rate is still high since the long distance between the gas producer and dumpflood well helps delay water breakthrough at producer. As long as there is no early water breakthrough, the earlier the energy is supplied to the gas reservoirs, the better the gas recovery. On the other hand, for the systems having a small or moderate aquifer size and short distance between the two wells, performing water dumpflood when the rate is close to the economic rate is better because water is more likely to cause an early breakthrough when the distance is short. Water dumpflood into multiple nearly-depleted or depleted gas reservoirs is a novel study. The idea of using water dumpflood to increase gas recovery has been mentioned in the literature but has never been investigated. This detailed study will help a practicing engineer to understand the benefits of such method and can implement it with minimum cost and risk.

Keywords: dumpflood, increase gas recovery, low-pressure gas reservoir, multiple gas reservoirs

Procedia PDF Downloads 446

Authors: Rajesha Kumar Alambi, Mansour Ahmed, Garudachari Bhadrachari, Safiyah Al-Muqahwi, Mansour Al-Rughaib, Jibu P. Thomas

Abstract:

Membrane-based pressure assisted osmosis (PAO) for seawater desalination has the potential to overcome the challenges of forward osmosis technology. PAO technology is gaining interest among the research community to ensure the sustainability of freshwater with a significant reduction in energy. The requirements of PAO membranes differ from the FO membrane; as it needs a slightly higher porous with sufficient mechanical strength to overcome the applied hydraulic pressure. The porous metal-organic framework (MOF) as a filler for the membrane synthesis has demonstrated a great potential to generate new channels for water transport, high selectivity, and reduced fouling propensity. Accordingly, this study is aimed at fabricating the UiO-66 MOF-based thin film nanocomposite membranes with specific characteristics for water desalination by PAO. A PAO test unit manufactured by Trevi System, USA, was used to determine the performance of the synthesized membranes. Further, the synthesized membranes were characterized in terms of morphological features, hydrophilicity, surface roughness, and mechanical properties. The 0.05 UiO-66 loaded membrane produced highest flux of 38L/m2h and with low reverse salt leakage of 2.1g/m²h for the DI water as feed solution and 2.0 M NaCl as draw solutions at the inlet feed pressure of 0.6 MPa. The new membranes showed a good tolerance toward the applied hydraulic pressure attributed to the fabric support used during the membrane synthesis.

Keywords: metal organic framework, composite membrane, desalination, salt rejection, flux

Procedia PDF Downloads 137

Authors: C. C. Egwuonwu, N. A. A. Okereke, K. O. Chilakpu, S. O. Ohanyere

Abstract:

In this study, initial soil strength indices (qu) and stress-strain characteristics, namely failure strain (ϵf), area under the stress-strain curve up to failure (Is) and stress-strain modulus between no load and failure (Es) were investigated as potential indicators for characterizing the erosion resistance of two compacted soils, namely sandy clay loam (SCL) and clay loam (CL) in some selected sites in Enugu State, Nigeria. The unconfined compressive strength (used in obtaining strength indices) and stress-strain measurements were obtained as a function of moisture content in percentage (mc %) and dry density (γd). Test were conducted over a range of 8% to 30% moisture content and 1.0 g/cm3 to 2.0 g/cm3 dry density at applied loads of 20, 40, 80, 160 and 320 kPa. Based on the results, it was found out that initial soil strength alone was not a good indicator of erosion resistance. For instance, in the comparison of exponents of mc% and γd for jet index or erosion resistance index (Ji) and the strength measurements, qu and Es agree in signs for mc%, but are opposite in signs for γd. Therefore, there is an inconsistency in exponents making it difficult to develop a relationship between the strength parameters and Ji for this data set. In contrast, the exponents of mc% and γd for Ji and ϵf and Is are opposite in signs, there is potential for an inverse relationship. The measured stress-strain characteristics, however, appeared to have potential in providing useful information on erosion resistance. The models developed for the prediction of the extent or the susceptibility of soils to erosion and subjected to sensitivity test on some selected sites achieved over 90% efficiency in their functions.

Keywords: characterization of erodibility, selected sites in Enugu state, soil strength, stress-strain indices

Procedia PDF Downloads 416

Authors: Sonia Machraoui, Salam Labidi, Karunakara Naregundi

Abstract:

Environmental radiation measurements are useful to identify areas of potential natural radiation hazard particularly in areas of phosphate industries where enhanced radiation levels are expected to be present. Measurements of primordial radionuclides concentrations have been carried out in samples collected from Sfax City around the SIAPE phosphate industry of Tunis. The samples analysed include fish, beef meat, egg, and vegetables as well as in soil and grass. Measurements were performed by gamma spectrometry method using a 42% relative efficiency N-type HPGe detector. The activity concentrations of radionuclides were measured by gamma ray spectrometry. As expected, the concentrations of radionuclides belonging to uranium and thorium series were low in food materials. In all the samples analysed, the 137Cs concentration was below detection level, except meat samples which showed the activity concentration of 2.4 Bq kg-1 (dry wt.) The soil to grass transfer factor was found to be similar to those reported in literature. The effective dose to the population due to intake of food products were also estimated and are presented in this paper.

Keywords: effective doses, phosphate industry, transfer coefficients, Tunisia

Procedia PDF Downloads 221

Authors: Kaige Shi, Chao Jiang, Xin Li

Abstract:

The swirl gripper is an electrically activated noncontact handling device that uses swirling airflow to generate a lifting force. This force can be used to pick up a workpiece placed underneath the swirl gripper without any contact. It is applicable, for example, in the semiconductor wafer production line, where contact must be avoided during the handling and moving of a workpiece to minimize damage. When a workpiece levitates underneath a swirl gripper, the gap height between them is crucial for safe handling. Therefore, in this paper, we propose a method to estimate the levitation gap height by detecting pressure at two points. The method is based on theoretical model of the swirl gripper, and has been experimentally verified. Furthermore, the force between the gripper and the workpiece can also be estimated using the detected pressure. As a result, the nonlinear relationship between the force and gap height can be linearized by adjusting the rotating speed of the fan in the swirl gripper according to the estimated force and gap height. The linearized relationship is expected to enhance handling stability of the workpiece.

Keywords: swirl gripper, noncontact handling, levitation, gap height estimation

Procedia PDF Downloads 135

Authors: P. Meethum, C. Suvanjumrat

Abstract:

Many aluminum motorcycle parts produced by a high pressure die casting. Some parts such as fuel caps were a thin and complex shape. This part risked for porosities and blisters on surface if it only depended on an experience of mold makers for mold design. This research attempted to use CAST-DESIGNER software simulated the high pressure die casting process with the same process parameters of a motorcycle fuel cap production. The simulated results were compared with fuel cap products and expressed the same porosity and blister locations on cap surface. An average of absolute difference of simulated results was obtained 0.094 mm when compared the simulated porosity and blister defect sizes on the fuel cap surfaces with the experimental micro photography. This comparison confirmed an accuracy of software and will use the setting parameters to improve fuel cap molds in the further work.

Keywords: aluminum, die casting, fuel cap, motorcycle

Procedia PDF Downloads 368

Authors: Taweesak Janyacharoen, Lalita Pradubgool, Lalita Wongsorn, Pitchayapa Janyacharoen

Abstract:

Street dance is a form of exercise that is classified as aerobic and is very suitable for teenagers. Street dance is a dance that can create new dance moves all the time. It often incorporates elements from gymnastics and is accompanied by fast-paced music that emphasizes excitement and energy. It is a combination of high-intensity and low-intensity activities. Few studies have looked at the effects of street dance on cardiovascular endurance, and previous studies have long-term effects. However, no research study in Thailand has studied acute effects before. This study was to investigate the acute effect of street dance exercise on blood pressure, heart rate, oxygen saturation and physical fitness in sedentary subjects. Subjects were divided into 2 groups: the control group (n=15) received health education and rest, and the experimental group (n=15) received street dance exercise. Both groups will measure their blood pressure (BP), mean arterial pressure (MAP), heart rate (HR), oxygen saturation (SpO₂) and six-minute walk test (6MWT) before and after completing the program. The results found that both groups had significantly different HR when comparing before and after the program (p<0.05). MAP, HR and SpO₂ had significantly different (p<0.05) when compared between groups. This study concluded that the acute effect of street dance exercise could be increased in HR while the SpO₂ decreased. In clinical, it was seen that the values that were changed are still within the range that is considered normal. Therefore, street dance exercises can be used as one choice of alternative exercise.

Keywords: street dance, exercise, blood pressure, heart rate, oxygen saturation

Procedia PDF Downloads 44

Authors: Ayorinde B. Ogunremi, Kehinde A. Adewoyin, Adebamwo Adebayo

Abstract:

Record of radionuclide concentration in an environment is essential to ensure human safety due to exposure to ionizing radiation. This study aimed at assessing the radionuclide concentration and doses from soil samples in the study area. Twenty soil samples were collected and dried in the oven at 110°C to remove the moisture, pulverized, and sieved. 200 g of each of the samples were sealed in cylindrical sample holders; they were left for four weeks to attain secular equilibrium between ²²⁶Ra and its decay daughters, after which the sample was analyzed using gamma-ray spectrometry. After the well-guided procedure for the calibrations, the analysis of the samples was carried out using a well-calibrated NaI (TI) and well-shielded detector coupled to a computer resident quantum MCA2100 R Multichannel analyzer for 36,000 s. The mean activity concentrations of ⁴⁰K, ²²⁶Ra, and ²³²Th obtained were calculated to be 272.37 ± 33.58, 10.97 ± 3.24, 9.39 ± 2.27 Bqkg-1 respectively. The average absorbed dose obtained was 22.10 nGy/h. The radium equivalent activity (Raeq) was estimated to be 43.27 Bq/kg. The activity concentrations (Bq/kg) were below the recommended values, which are 420, 33, and 45 for ⁴⁰K, ²²⁶Ra, and ²³²Th, respectively. Considering the results, we conclude thus, the radiation level within the estate poses no significant health risk on dwellers and workers.

Keywords: absorbed, effective, multichannel, radionuclide

Procedia PDF Downloads 218

Authors: Marcin Dębowski, Mirosław Krzemieniewski, Marcin Zieliński

Abstract:

This publication presents a device designed to depolymerise and structurally change organic substrate, for use in agricultural biogas plants or sewage treatment plants. The presented device consists of a heated tank equipped with an inlet valve for the crude substrate and an outlet valve for the treated substrate. The system also includes a gas conduit, which is at its tip equipped with a high-pressure solenoid valve and a vacuum relief solenoid valve. A conduit behind the high-pressure solenoid valve connects to the vacuum tank equipped with the outlet valve. The substrate introduced into the device is exposed to agents such as high temperature and cavitation produced by abrupt, short-term reduction of pressure within the heated tank. The combined effect of these processes is substrate destruction rate increase of about 20% when compared to using high temperature alone, and about 30% when compared to utilizing only cavitation. Energy consumption is greatly reduced, as the pressure increase is generated by heating the substrate. Thus, there is a 18% reduction of energy consumption when compared to a device designed to destroy substrate through high temperature alone, and a 35% reduction if compared to using cavitation as the only means of destruction.

Keywords: thermal depolymerisation, organic substrate, biogas, pre-treatment

Procedia PDF Downloads 568

Authors: Zahra Zamanian, Alireza Zamanian, Jafar Hasanzadeh

Abstract:

Background: Unwanted sound, as one of the most important physical factors in the majority of production units, imposes a great number of problems on the industrial workers. Sound is one of the environmental factors which can cause physical as well as psychological damages and also affects the individuals’ performance and productivity. Therefore, the present study aimed to determine the effect of noise exposure on human performance. Methods: The present study assessed the effect of noise on the performance of 50 students of Shiraz University of Medical Sciences (25 males and 25 females) at the sound pressures of 70, 90, and 110 dB by using two factors of physical features and the creation of different conditions of sound pressure source as well as applying Two-Arm coordination Test. Results: The results of the present study revealed no significant difference between male and female subjects as well as different conditions of creating sound pressure regarding the length of performance (p> 0.05). In addition, as the sound pressure increased, the length of performance increased, as well. According to the results, no significant difference was found between the performance at 70 and 90 dB. On the other hand, the performance at 110 dB was significantly different from the performance at 70 and 90 dB (p<0.05 and p<0.001). Conclusion: In general, as the sound pressure increases, the performance decreases which results in a considerable increase in the individuals’ rate of error.

Keywords: physical factors, two-arm coordination test, Shiraz University of Medical Sciences, noise

Procedia PDF Downloads 306

Authors: A. Ritcey, J. R. Mcdermid, S. Ziada

Abstract:

Wall shear stress was experimentally measured under a planar impinging air jet as a function of jet Reynolds number (Rejet = 5000, 8000, 11000) and different normalized impingement distances (H/D = 4, 6, 8, 10, 12) using the razor blade technique to complete a parametric study. The wall pressure, wall pressure gradient, and wall shear stress information were obtained.

Keywords: experimental fluid mechanics, impinging planar jets, skin friction factor, wall shear stress

Procedia PDF Downloads 324

Authors: A. Bayoumi, M. Abdallah, F. Hage Chehade

Abstract:

Structures on the ground surface bear impact from the tunneling-induced settlement, especially when twin tunnels are constructed. The tunneling influence on the structure is considered as a critical issue based on the construction procedure and relative position of tunnels. Lebanon is suffering from a traffic phenomenon caused by the lack of transportation systems. After several traffic counts and geotechnical investigations in Beirut city, efforts aim for the construction of tunneling systems. In this paper, we present a non-linear numerical modeling of the effect of the twin tunnels constructions on the structures located at soil surface for a particular site in Beirut. A parametric study, which concerns the geometric configuration of tunnels, the distance between their centers, the construction order, and the position of the structure, is performed. The tunnel-soil-structure interaction is analyzed by using the non-linear finite element modeling software PLAXIS 2D. The results of the surface settlement and the bending moment of the structure reveal significant influence when the structure is moved away, especially in vertical aligned tunnels.

Keywords: bending moment, elastic modulus, horizontal twin tunnels, soil, structure location, surface settlement, vertical twin tunnels

Procedia PDF Downloads 300

Authors: F. Q. Shao, W. Q. Wang, Y. Yin, T. P. Yu, D. B. Zou, J. M. Ouyang

Abstract:

The Radiation Pressure Acceleration (RPA) mechanism is very promising in laser-driven ion acceleration because of high laser-ion energy conversion efficiency. Although some experiments have shown the characteristics of RPA, the energy of ions is quite limited. The ion energy obtained in experiments is only several MeV/u, which is much lower than theoretical prediction. One possible limiting factor is the transverse instability incited in the RPA process. The transverse instability is basically considered as the Rayleigh-Taylor (RT) instability, which is a kind of interfacial instability and occurs when a light fluid pushes against a heavy fluid. Multi-dimensional particle-in-cell (PIC) simulations show that the onset of transverse instability will destroy the acceleration process and broaden the energy spectrum of fast ions during the RPA dominant ion acceleration processes. The evidence of the RT instability driven by radiation pressure has been observed in a laser-foil interaction experiment in a typical RPA regime, and the dominant scale of RT instability is close to the laser wavelength. The development of transverse instability in the radiation-pressure-acceleration dominant laser-foil interaction is numerically examined by two-dimensional particle-in-cell simulations. When a laser interacts with a foil with modulated surface, the internal instability is quickly incited and it develops. The linear growth and saturation of the transverse instability are observed, and the growth rate is numerically diagnosed. In order to optimize interaction parameters, a method of information entropy is put forward to describe the chaotic degree of the transverse instability. With moderate modulation, the transverse instability shows a low chaotic degree and a quasi-monoenergetic proton beam is produced.

Keywords: information entropy, radiation pressure acceleration, Rayleigh-Taylor instability, transverse instability

Procedia PDF Downloads 347

Authors: Bartosz Olszanski, Zbigniew Nosal, Jacek Rokicki

Abstract:

An experimental study of cold-jet (nitrogen) reaction control jet system has been carried out to investigate the flow control efficiency for low to moderate jet pressure ratios (total jet pressure p0jet over free stream static pressure in the wind tunnel p∞) and different angles of attack for infinite Mach number equal to 2. An investigation of jet influence was conducted on a flat plate geometry placed in the test section of intermittent supersonic wind tunnel of Department of Aerodynamics, WUT. Various convergent jet nozzle geometries to obtain different jet momentum ratios were tested on the same test model geometry. Surface static pressure measurements, Schlieren flow visualizations (using continuous and photoflash light source), load cell measurements gave insight into the supersonic crossflow interaction for different jet pressure and jet momentum ratios and their influence on the efficiency of side jet control as described by the amplification factor (actual to theoretical net force generated by the control nozzle). Moreover, the quasi-steady numerical simulations of flow through the same wind tunnel geometry (convergent-divergent nozzle plus test section) were performed using ANSYS Fluent basing on Reynolds-Averaged Navier-Stokes (RANS) solver incorporated with k-ω Shear Stress Transport (SST) turbulence model to assess the possible spurious influence of test section walls over the jet exit near field area of interest. The strong bow shock, barrel shock, and Mach disk as well as lambda separation region in front of nozzle were observed as images taken by high-speed camera examine the interaction of the jet and the free stream. In addition, the development of large-scale vortex structures (counter-rotating vortex pair) was detected. The history of complex static pressure pattern on the plate was recorded and compared to the force measurement data as well as numerical simulation data. The analysis of the obtained results, especially in the wake of the jet showed important features of the interaction mechanisms between the lateral jet and the flow field.

Keywords: flow visualization techniques, pressure measurements, reaction control jet, supersonic cross flow

Procedia PDF Downloads 301

Authors: B. Medjadji, L. Aminallah, B. Serier, M. Benlebna

Abstract:

In this study, the finite element method in 3-D is used to calculate the integral J in the semi-elliptical crack in a pipe subjected to internal pressure. The stress-strain curve of the pipe has been determined experimentally. The J-integral was calculated in two fronts crack (Ф = 0 and Ф = π/2). The effect of the configuration of the crack on the J integral is analysed. The results show that an external longitudinal crack in a pipe is the most dangerous. It also shows that the increase in the applied pressure causes a remarkable increase of the integral J. The effect of the depth of the crack becomes important when the ratio between the depth of the crack and the thickness of the pipe (a / t) tends to 1.

Keywords: J integral, pipeline, crack, MEF

Procedia PDF Downloads 413

Authors: Mario Perez-Won, Roberto Lemus-Mondaca, Constanza Olivares-Rivera, Fernanda Marin-Monardez

Abstract:

This research presents the simultaneous application of high hydrostatic pressure (HHP) and osmotic dehydration (DO) as a pretreatment to hot –air drying of jumbo squid (Dosidicus gigas) cubes. The drying time was reduced to 2 hours at 60ºC and 5 hours at 40°C as compared to the jumbo squid samples untreated. This one was due to osmotic pressure under high-pressure treatment where increased salt saturation what caused an increasing water loss. Thus, a more reduced time during convective drying was reached, and so water effective diffusion in drying would play an important role in this research. Different working conditions such as pressure (350-550 MPa), pressure time (5-10 min), salt concentration, NaCl (10 y 15%) and drying temperature (40-60ºC) were optimized according to kinetic parameters of each mathematical model. The models used for drying experimental curves were those corresponding to Weibull, Page and Logarithmic models, however, the latest one was the best fitted to the experimental data. The values for water effective diffusivity varied from 4.82 to 6.59x10-9 m2/s for the 16 curves (DO+HHP) whereas the control samples obtained a value of 1.76 and 5.16×10-9 m2/s, for 40 and 60°C, respectively. On the other hand, quality characteristics such as color, texture, non-enzymatic browning, water holding capacity (WHC) and rehydration capacity (RC) were assessed. The L* (lightness) color parameter increased, however, b * (yellowish) and a* (reddish) parameters decreased for the DO+HHP treated samples, indicating treatment prevents sample browning. The texture parameters such as hardness and elasticity decreased, but chewiness increased with treatment, which resulted in a product with a higher tenderness and less firmness compared to the untreated sample. Finally, WHC and RC values of the most treatments increased owing to a minor damage in tissue cellular compared to untreated samples. Therefore, a knowledge regarding to the drying kinetic as well as quality characteristics of dried jumbo squid samples subjected to a pretreatment of osmotic dehydration under high hydrostatic pressure is extremely important to an industrial level so that the drying process can be successful at different pretreatment conditions and/or variable processes.

Keywords: diffusion coefficient, drying process, high pressure, jumbo squid, modelling, quality aspects

Procedia PDF Downloads 248

Authors: N. Lebga, Kh. Bouamama, K. Kassali

Abstract:

We report first-principles calculation results on the structural and elastic properties of ZnS x Se1−x alloy for which we employed the virtual crystal approximation provided with the ABINIT program. The calculations done using density functional theory within the local density approximation and employing the virtual-crystal approximation, we made a comparative study between the numerical results obtained from ab-initio calculation using ABINIT or Wien2k within the Density Functional Theory framework with either Local Density Approximation or Generalized Gradient approximation and the pseudo-potential plane-wave method with the Hartwigzen Goedecker Hutter scheme potentials. It is found that the lattice parameter, the phase transition pressure, and the elastic constants (and their derivative with respect to the pressure) follow a quadratic law in x. The variation of the elastic constants is also numerically studied and the phase transformations are discussed in relation to the mechanical stability criteria.

Keywords: density functional theory, elastic properties, ZnS, ZnSe,

Procedia PDF Downloads 575

Authors: Baba Hassane Ahmed Hisseini, Abdelkrim Bennabi, Rabah Hamzaoui, Lamis Makki, Gaetan Blanck

Abstract:

Most of the clay soils are known as problematic soils due to their water content, which varies greatly over time. It is observed that they are used to be subject to shrinkage and swelling, thus causing a problem of stability on the structures of civil engineering construction work. They are often excavated and placed in a storage area giving rise to the opening of new quarries. This method has become obsolete today because to protect the environment, we are leading to think differently and opening the way to new research for the improvement of the performance of this type of clay soils to reuse them in the construction field. The solidification and stabilization technique is used to improve the properties of poor quality soils to transform them into materials with a suitable performance for a new use in the civil engineering field rather than to excavate them and store them in the discharge area. In our case, the polymerization method is used for bad clay soils classified as high plasticity soil class A4 according to the French standard NF P11-300, where classical treatment methods with cement or lime are not efficient. Our work concerns clay soil treatment study using raw materials as additives for solidification and stabilization. The geopolymers are synthesized by aluminosilicates materials like fly ash, metakaolin, or blast furnace slag and activated by alkaline solution based on sodium hydroxide (NaOH), sodium silicate (Na2SiO3) or a mixture of both of them. In this study, we present the mechanical properties of the soil clay (A4 type) evolution with geopolymerisation methods treatment. Various mix design of aluminosilicates materials and alkaline solutions were carried at different percentages and different curing times of 1, 7, and 28 days. The compressive strength of the untreated clayey soil could be increased from simple to triple. It is observed that the improvement of compressive strength is associated with a geopolymerization mechanism. The highest compressive strength was found with metakaolin at 28 days.

Keywords: treatment and valorization of clay-soil, solidification and stabilization, alkali-activation of co-product, geopolymerization

Procedia PDF Downloads 162

Authors: P. Lestinsky, D. Jecha, V. Brummer, P. Stehlik

Abstract:

Scrubbing by a liquid spraying is one of the most effective processes used for removal of fine particles and soluble gas pollutants (such as SO2, HCl, HF) from the flue gas. There are many configurations of scrubbers designed to provide contact between the liquid and gas stream for effectively capturing particles or soluble gas pollutants, such as spray plates, packed bed towers, jet scrubbers, cyclones, vortex and venturi scrubbers. The primary function of venturi scrubber is the capture of fine particles as well as HCl, HF or SO2 removal with effect of the flue gas temperature decrease before input to the absorption column. In this paper, sulfur dioxide (SO2) from flue gas was captured using new design replacing venturi scrubber (1st degree of wet scrubbing). The flue gas was prepared by the combustion of the carbon disulfide solution in toluene (1:1 vol.) in the flame in the reactor. Such prepared flue gas with temperature around 150 °C was processed in designed laboratory O-element scrubber. Water was used as absorbent liquid. The efficiency of SO2 removal, pressure drop and temperature drop were measured on our experimental device. The dependence of these variables on liquid-gas ratio was observed. The average temperature drop was in the range from 150 °C to 40 °C. The pressure drop was increased with increasing of a liquid-gas ratio, but not as much as for the common venturi scrubber designs. The efficiency of SO2 removal was up to 70 %. The pressure drop of our new designed wet scrubber is similar to commonly used venturi scrubbers; nevertheless the influence of amount of the liquid on pressure drop is not so significant.

Keywords: desulphurization, absorption, flue gas, modeling

Procedia PDF Downloads 402

Authors: Sean T. S. Wei, Joy D. Van Nostrand, Annapoorna Maitrayee Ganeshram, Stephen B. Pointing

Abstract:

McMurdo Dry Valleys are a largely ice-free polar desert protected by international treaty as an Antarctic special managed area. The terrestrial landscape is dominated by oligotrophic mineral soil with extensive rocky outcrops. Several environmental stresses: low temperature, lack of liquid water, UV exposure and oligotrophic substrates, restrict the major biotic component to microorganisms. The bacterial diversity and the putative physiological capacity of microbial communities of quartz rocks (hypoliths) and soil of a maritime-influenced Dry Valleys were interrogated by two metagenomic approaches: 454 pyro-sequencing and Geochp DNA microarray. The most abundant phylum in hypoliths was Cyanobacteria (46%), whereas in solils Actinobacteria (31%) were most abundant. The Proteobacteria and Bacteriodetes were the only other phyla to comprise >10% of both communities. Carbon fixation was indicated by photoautotrophic and chemoautotrophic pathways for both hypolith and soil communities. The fungi accounted for polymer carbon transformations, particularly for aromatic compounds. The complete nitrogen cycling was observed in both communities. The fungi in particular displayed pathways related to ammonification. Environmental stress response pathways were common among bacteria, whereas the nutrient stress response pathways were more widely present in bacteria, archaea and fungi. The diversity of bacterialphage was also surveyed by Geochip. Data suggested that different substrates supported different viral families: Leviviridae, Myoviridae, Podoviridae and Siphoviridiae were ubiquitous. However, Corticoviridae and Microviridae only occurred in wetter soils.

Keywords: Antarctica, hypolith, soil, dry valleys, geochip, functional diversity, stress response

Procedia PDF Downloads 453

Authors: Barkaoui Asma

Abstract:

In our article, we use the economic approach of measuring advertising effectiveness to show the margin of advertising spread gained through digital communication. For economists, profit maximization depends on determining the optimal advertising budget. For this, they use the theories of the marginalist current to determine when the maximum level of benefits is reached. Using the economic approach we show the significant return on investment for advertisers. We then discuss the risks of perception of advertising pressure by consumers.

Keywords: digital advertising, economic approach, effectiveness, pressure

Procedia PDF Downloads 305

Authors: M. Shivakumar, S. R. Somashekhar, C. V. Raju

Abstract:

Secondary salinization of agricultural lands in any command areas of the world is the major issue in the recent past. Currently, it is estimated that the 954 mh of saline and alkaline soil is present in the world. Thousands of hectares of land, getting added every year. Argentina, Bangladesh and Australia are most affected countries. In India, out of 142.80 million hectare (mh) cropped area, 56 mh is irrigated area. Of which, more than 9 mh (about 16.%) of land is found to be alkaline/saline. Due to continuous utilization of same land for same agricultural activities, excessive usage of fertilizers and water, most of the soils have become alkaline, saline or water logged. These lands are low productive and at times totally unfit for agricultural activities. These soils may or may not posses good physical condition, but plants may suffer from its inability to absorb water from salty solution. Plants suffer from dehydration and loose water to the soil, shrink, resulting death of plant. This process is called plasmolysis. It is the fact that soil is an independent, organic body of nature that acquires properties in accordance with forces which act upon it. Aquaculture is one of the solutions to utilize such problematic soils for food production. When the impoundments are constructed in an area 10-15% of the affected areas, the excess water along with the salts gets into impoundments and management of salt is easier in water than in the soil. Due to high organic input in aquaculture such as feed, manure and continuous deposition of fecal matter, pH of the soil gets reduced and over the period of time such soils can be put back into the original activity. Under National Agricultural Development Program (NADP), the project was implemented in 258 villages of Mandya District, Karnataka State, India and found that these lands can be effectively utilized for fish culture and increase the proteinacious food production by many folds while conserving the soils. The findings of the research can be adopted and up scaled in any country.

Keywords: saline and alkaline soils, Aquaculture, Problematic soils, Reclamation

Procedia PDF Downloads 142

Authors: George D. Ranis, Valasia Iakovoglou, George N. Zaimes

Abstract:

Fires are one of the main types of disturbances that shape ecosystems in the Mediterranean region. However nowadays, climate alterations towards higher temperature regimes results on the increased levels of the intensity, frequency and the spread of fires inducing obstacles for the natural regeneration. Thasos Island is one of the Greek islands that have experienced those problems. Since 1984, a series of wildfires led to the reduction of forest cover from 61.6% to almost 20%. The negative impacts were devastating in many different aspects for the island. The absence of plant cover, post-wildfire precipitation and steep slopes were the major factors that induced severe soil erosion and intense flooding events. That also resulted to serious economic problems to the local communities and the ability of the burnt areas to regenerate naturally. Despite the substantial amount of published work regarding Thasos wildfires, there is no information related to post-wildfire effects on the hydrology and soil erosion. More research related to post-fire effects should help to an overall assessment of the negative impacts of wildfires on land degradation through processes such as soil erosion and flooding.

Keywords: erosion, land degradation, Mediterranean islands, regeneration, Thasos, wildfires

Procedia PDF Downloads 328

Authors: A. Karadeniz, Belgin Kucukomeroglu

Abstract:

In this study natural gamma radioactivity levels are determined on sands along the coastal regions of Giresun/Turkey. The coast of Giresun about 290 km long in investigated to collect 101 sand samples. Natural and artificial radioactivity concentrations of sand samples were measured by using HPGe gamma spectrometry. The average activity concentrations of 238U, 232Th, 40K and 137Cs on sand samples of Giresun were found to be 10.83±2.92 Bq/kg, 21.28±3.22 Bq/kg, 6.42±1.06 Bq/kg, 230.94±10.67 Bq/kg respectively. The average activity concentrations for these radionuclides were compared with the reported data of other parts of Turkey and other countries. The average absorbed dose rate for Giresun was calculated to be 38.68 nGy/h respectively. This value is significantly lower than the World averaged value of 60 nGy/h. The external annual effective dose rate concentration in Giresun was found to be 0.047 mSv/y respectively. This result is much lower than the recommeded limit of 5 mSv/y. The external hazard dose rate for Giresun weas calculated to be 0.21 respectively. This result is much lower than the recommended limit of 1.0.

Keywords: concentration, radioactivity, Giresun, natural gamma radioactivity

Procedia PDF Downloads 394

Authors: Pradip Choudhury, Tapobrata Sanyal

Abstract:

Effectiveness of Jute Geotextiles (JGT) in hill slope management now stands substantiated. The reasons of its efficacy are attributed to its bio-degradability, hygroscopic property and its thickness. Usually open weave JGT is used for slope management. Thickness of JGT helps in reducing the velocity of surface run-off, thus curbing the extent of migration of soil particles detached as a result of kinetic energy of rain-drops and also of wind effects. Initially JGT acts as cover of the surface of slope thus protect movement of loose soil particles. Hygroscopic property of jute effects overland storage of the flow. JGT acts as mulch and creates a congenial micro-climate that fosters quick growth of vegetation on bio-degradation. In fact JGT plays an important role in bio-remediation of slope-erosion problems. Considering the environmental aftermath, JGT is the preferred option in developed countries for surface soil conservation against erosion. In India JGT has not been tried in low temperature zones at high altitudes where temperature goes below the freezing point (even below - 25° Celsius). The behavior of JGT in such low-temperature zones is not precisely known. The 16th BRTF of Project Himank of Border Roads Organization (BRO) has recently taken the initiative to try two varieties of JGT , ie, 292 gsm and 500 gsm at two different places for hill slope management in Leh, a high altitude place of about 2,660 mtrs and 4900 mtrs above MSL respectively in Jammu & Kashmir where erosion is caused more as a result of rapid movement of sand particles due to high wind (wind erosion. Soil particles of the region formed naturally by weathering of fragile rocks are usually loosely bonded (non-cohesive), undergo dissociation with the rise in wind force and kinetic energy of rain drops and are blown away by wind. Open weave JGT interestingly was observed to contain the dissociated soil particles within its pores and lend stability the affected soil mass to a great extent thus preventing its movement by extraneous agents such as wind. The paper delineates about climatic factors, type of JGT used and the prevailing site conditions with an attempt to analyze the mechanism of functioning of JGT in low temperature zones.

Keywords: climate, erosion, jutegeotextile, stabilize

Procedia PDF Downloads 432

Authors: Yusuf Ersoy Yildirim, Ismail Tas, Ceren Gorgusen, Tugba Yeter, Aysegul Boyacioglu, K. Mehmet Tugrul, Murat Tugrul, Ayten Namli, H. Sabri Ozturk, M. Onur Akca

Abstract:

In recent years, a lot of research has been done for the sustainable use of scarce resources in the world. Especially, effective and sustainable use of water resources has been researched for many years. Sub-surface drip irrigation (SDI) is one of the most effective irrigation methods in which efficient and sustainable use of irrigation water can be achieved. When the literature is taken into consideration, it is often emphasized that, besides its numerous advantages, it also allows the application of irrigation water to the plant root zone along with air. It is stated in different studies that the air applied to the plant root zone with irrigation water has a positive effect on the root zone. Plants need sufficient oxygen for root respiration as well as for the metabolic functions of the roots. Decreased root respiration due to low oxygen content reduces transpiration, disrupts the flow of ions, and increases the ingress of salt reaching toxic levels, seriously affecting plant growth. Lack of oxygen (Hypoxia) can affect the survival of plants. The lack of oxygen in the soil is related to the exchange of gases in the soil with the gases in the atmosphere. Soil aeration is an important physical parameter of a soil. It is highly dynamic and is closely related to the amount of water in the soil and its bulk weight. Subsurface drip irrigation; It has higher water use efficiency compared to irrigation methods such as furrow irrigation and sprinkler irrigation. However, in heavy clay soils, subsurface drip irrigation creates continuous wetting fronts that predispose the rhizosphere region to hypoxia or anoxia. With subsurface drip irrigation, the oxygen is limited for root microbial respiration and root development, with the continuous spreading of water to a certain region of the root zone. In this study, the change in sugar beet yield caused by air application in the SDI system will be explained.

Keywords: sugar beet, subsurface drip irrigation, air application, irrigation efficiency

Procedia PDF Downloads 83

Authors: Ahmed O. Apampa, Yinusa A. Jimoh

Abstract:

The potential economic viability and environmental benefits of using a biomass waste, such as corn cob ash (CCA) as pozzolan in stabilizing soils for road pavement construction in a sub-tropical region was investigated. Corn cob was obtained from Maya in South West Nigeria and processed to ash of characteristics similar to Class C Fly Ash pozzolan as specified in ASTM C618-12. This was then blended with ordinary Portland cement in the CCA:OPC ratios of 1:1, 1:2 and 2:1. Each of these blends was then mixed with lateritic soil of ASHTO classification A-2-6(3) in varying percentages from 0 – 7.5% at 1.5% intervals. The soil-CCA-Cement mixtures were thereafter tested for geotechnical index properties including the BS Proctor Compaction, California Bearing Ratio (CBR) and the Unconfined Compression Strength Test. The tests were repeated for soil-cement mix without any CCA blending. The cost of the binder inputs and optimal blends of CCA:OPC in the stabilized soil were thereafter analyzed by developing algorithms that relate the experimental data on strength parameters (Unconfined Compression Strength, UCS and California Bearing Ratio, CBR) with the bivariate independent variables CCA and OPC content, using Matlab R2011b. An optimization problem was then set up minimizing the cost of chemical stabilization of laterite with CCA and OPC, subject to the constraints of minimum strength specifications. The Evolutionary Engine as well as the Generalized Reduced Gradient option of the Solver of MS Excel 2010 were used separately on the cells to obtain the optimal blend of CCA:OPC. The optimal blend attaining the required strength of 1800 kN/m2 was determined for the 1:2 CCA:OPC as 5.4% mix (OPC content 3.6%) compared with 4.2% for the OPC only option; and as 6.2% mix for the 1:1 blend (OPC content 3%). The 2:1 blend did not attain the required strength, though over a 100% gain in UCS value was obtained over the control sample with 0% binder. Upon the fact that 0.97 tonne of CO2 is released for every tonne of cement used (OEE, 2001), the reduced OPC requirement to attain the same result indicates the possibility of reducing the net CO2 contribution of the construction industry to the environment ranging from 14 – 28.5% if CCA:OPC blends are widely used in soil stabilization, going by the results of this study. The paper concludes by recommending that Nigeria and other developing countries in the sub-tropics with abundant stock of biomass waste should look in the direction of intensifying the use of biomass waste as fuel and the derived ash for the production of pozzolans for road-works, thereby reducing overall green house gas emissions and in compliance with the objectives of the United Nations Framework on Climate Change.

Keywords: corn cob ash, biomass waste, lateritic soil, unconfined compression strength, CO2 emission

Procedia PDF Downloads 375

Authors: W. G. Kim, C. H. Jo

Abstract:

We analyzed the effects of variations in the diameter of silicone rubber and polyvinyl chloride (PVC) tubings on the likelihood of tubing rupture during modeling of accidental arterial line clamping in cardiopulmonary bypass with a roller pump. A closed CPB circuit constructed with a roller pump was tested with both PVC and silicone rubber tubings of 1/2, 3/8, and 1/4 inch internal diameter. Arterial line pressure was monitored, and an occlusive clamp was placed across the tubing distal to the pressure monitor site to model an accidental arterial line occlusion. A CCD camera with 512(H) x 492(V) pixels was installed above the roller pump to measure tubing diameters at pump outlet, where the maximum deformations (distension) of the tubings occurred. Quantitative measurement of the changes of tubing diameters with the change of arterial line pressure was performed using computerized image processing techniques. A visible change of tubing diameter was generally noticeable by around 250 psi of arterial line pressure, which was already very high. By 1500 psi, the PVC tubings showed an increase of diameter of between 5-10 %, while the silicone rubber tubings showed an increase between 20-25 %. Silicone rubber tubings of all sizes showed greater distensibility than PVC tubings of equivalent size. In conclusion, although roller-pump induced tubing rupture remains a theoretical problem during cardiopulmonary bypass in terms of the inherent mechanism of the pump, in reality such an occurrence is impossible in real clinical conditions.

Keywords: roller pump, tubing rupture, cardiopulmonary bypass, arterial line

Procedia PDF Downloads 295

Authors: Y. H. Hwang, J. Won, Y. S. Kang

Abstract:

Supported ionic liquid membranes (SILMs) have attracted due to the negligible vapor pressure of ionic liquids (ILs) as well as the high gas selectivity for specific gases such as CO2 or olefin. 1-ethyl-3-methylimidazolium tricyanomethanide ([EMIM][TCM]), 1-butyl-3-methylimidazolium tricyanomethanide ([BMIM][TCM]), show high CO2 solubility, CO2 absorption, rapid CO2 absorption rate and negligible vapor pressure, SILMs using these ILs have been good candidates as CO2 separation membranes. However, SILM has to be operated at a low differential pressure to prevent the solvent from being expelled from the pores of supported membranes. In this paper, we improve the mechanical strength by forming ion gels which provide the stability while it retains the diffusion properties of the liquid stage which affects the gas separation properties. The ion gel was created by the addition of tri-block copolymer, poly(styrene-ethylene oxide-b-styrene) in RTIL. SILM using five different RTILs, are investigated with and without ion gels. The gas permeance were measured and the gas performance with and without the SEOS were investigated.

Keywords: ion gel, ionic liquid, membrane, nanostructure

Procedia PDF Downloads 314

Authors: Jadon Matthiasa, Cindy Donga, Ali Al Jibouria, Hsin Kuo

Abstract:

The environmental impact of emissions from the Covanta Waste-to-Energy facility in Burnaby, BC, was comprehensively evaluated, focusing on the dispersion of air pollutants and the subsequent assessment of heavy metal contamination in surrounding soils. A Gaussian Plume Model, implemented in MATLAB, was utilized to simulate the dispersion of key pollutants to understand their atmospheric behaviour and potential deposition patterns. The MATLAB code developed for this study enhanced the accuracy of pollutant concentration predictions and provided capabilities for visualizing pollutant dispersion in 3D plots. Furthermore, the code could predict the maximum concentration of pollutants at ground level, eliminating the need to use the Ranchoux model for predictions. Complementing the modelling approach, empirical soil sampling and analysis were conducted to evaluate heavy metal concentrations in the vicinity of the facility. This integrated methodology underscored the importance of computational modelling in air pollution assessment and highlighted the necessity of soil analysis to obtain a holistic understanding of environmental impacts. The findings emphasized the effectiveness of current emissions controls while advocating for ongoing monitoring to safeguard public health and environmental integrity.

Keywords: air emissions, Gaussian Plume Model, MATLAB, soil contamination, air pollution monitoring, waste-to-energy, pollutant dispersion visualization, heavy metal analysis, environmental impact assessment, emission control effectiveness

Procedia PDF Downloads 21