Search results for: rock and water combination

Authors: James Jin, Weisi Xia, Runzhe Gao, Alain Vandal, Darren Svirkis, Andrew Hill

Abstract:

Background: Post-haemorrhoidectomy pain is concerned by patients/clinicians. Minimizing the postoperation pain is highly interested clinically. Combinations of topical cream targeting three hypothesised post-haemorrhoidectomy pain mechanisms were developed and their effectiveness were evaluated. Specifically, a multi-centred double-blinded randomized clinical trial (RCT) was conducted in adults undergoing excisional haemorrhoidectomy. The primary analysis was conveyed on the data collected to evaluate the effectiveness of the combinations of topical cream targeting three hypothesized pain mechanisms after the operations. Methods: 192 patients were randomly allocated to 4 arms (each arm has 48 patients), and each arm was provided with pain cream 10% metronidazole (M), M and 2% diltiazem (MD), M with 4% lidocaine (ML), or MDL, respectively. Patients were instructed to apply topical treatments three times a day for 7 days, and record outcomes for 14 days after the operations. The primary outcome was VAS pain on day 4. Covariates and models were selected in the blind review stage. Multiple imputations were applied for the missingness. LMER, GLMER models together with natural splines were applied. Sandwich estimators and Wald statistics were used. P-values < 0.05 were considered as significant. Conclusions: The addition of topical lidocaine or diltiazem to metronidazole does not add any benefit. ML had significantly better pain and recovery scores than combination MDL. Multimodal topical analgesia with ML after haemorrhoidectomy could be considered for further evaluation. Further trials considering only 3 arms (M, ML, MD) might be worth exploring.

Keywords: RCT, primary analysis, multiple imputation, pain scores, haemorrhoidectomy, analgesia, lmer

Procedia PDF Downloads 93

Authors: Meenu Kaushik, Ayon K. Bandhoyadhayay, Lalit M. Joshi

Abstract:

Inductive output tubes (IOTs) are widely used as microwave power amplifiers for broadcast and scientific applications. It is capable of amplifying radio frequency (RF) power with very good efficiency. Its compactness, reliability, high efficiency, high linearity and low operating cost make this device suitable for various applications. The device consists of an integrated structure of electron gun and RF cavity, collector and focusing structure. The working principle of IOT is a combination of triode and klystron. The cathode lies in the electron gun produces a stream of electrons. A control grid is placed in close proximity to the cathode. Basically, the input part of IOT is the integrated structure of gridded electron gun which acts as an input cavity thereby providing the interaction gap where the input RF signal is applied to make it interact with the produced electron beam for supporting the amplification phenomena. The paper presents the design, fabrication and testing of a radial re-entrant cavity for implementing in the input structure of IOT at 350 MHz operating frequency. The model’s suitability has been discussed and a generalized mathematical relation has been introduced for getting the proper transverse magnetic (TM) resonating mode in the radial narrow gap RF cavities. The structural modeling has been carried out in CST and SUPERFISH codes. The cavity is fabricated with the Aluminum material and the RF characterization is done using vector network analyzer (VNA) and the results are presented for the resonant frequency peaks obtained in VNA.

Keywords: inductive output tubes, IOT, radial cavity, coaxial cavity, particle accelerators

Procedia PDF Downloads 107

Authors: Preeti Panthari, Harsha Kharkwal

Abstract:

Myrica nagi belongs to Myricaceae family. It is known for its therapeutic use since ancient times. The leaves were extracted with methanol and further fractioned with different solvents with increasing polarity. The n-butanol fraction of methanol extract was passed through celite, on separation through silica gel column chromatography yielded ten fractions. For the first time we report isolation of Caffeic acid from n-butanol fraction of Myrica nagi leaves in Chloroform: methanol (70:30) fraction. The mobile phase used for analysis in HPLC was Methanol: water (60:40) at the flow rate of 1 ml/min at wavelength of 280 nm. The retention time was 2.66 mins.

Keywords: Myrica nagi, column chromatography, retention time, caffeic acid

Procedia PDF Downloads 530

Authors: Radoslaw Lukasz Staniszewski

Abstract:

The aim of the research was to verify lateral extent and thickness variability of individual limestone layers within early-Jurassic medium- and thick-bedded limestone interbedded with marlstones. Location: The main research area is located in the south-central part of Poland in the south-western part of Permo-Mesozoic margin of the Holy Cross Mountains. It includes outcroppings located on the line between Mieczyn and Wola Morawicka. The analyses were carried out on six profiles (Mieczyn, Gniezdziska, Tokarnia, Wola Morawicka, Morawica and Wolica) representing three early-Jurassic links: Jasna Gora layers, grey limestone, Morawica limestone. Additionally, an attempt was made to correlate the thickness sequence from the Holy Cross Mountains to the profile from the quarry in Zawodzie located 3 km east of Czestochowa. The distance between the outermost profiles is 122 km in a straight line. Methodology of research: The Callovian-Oxfordian border was taken as the reference point during the correlation. At the same time, ammonite-based stratigraphic studies were carried out, which allowed to identify individual packages in the remote outcroppings. The analysis of data collected during fieldwork was mainly devoted to the correlation of thickness sequences of limestone layers in subsequent profiles. In order to check the objectivity of the subsequent outcroppings, the profiles have been presented in the form of the thickness functions of the subsequent layers. The generated functions were auto-correlated, and the Pearson correlation coefficient was calculated. The next step in the research was to statistically determine the percentage increment of the individual layers thickness in the subsequent profiles, and on this basis to plot the function of relative carbonate productivity. Results: The result of the above-mentioned procedures consists in illustrating the extent of 34 rock layers across the examined area in demonstrating the repeatability of their success in subsequent outcroppings. It can also be observed that the thickness of individual layers in the Holy Cross Mountains is increasing from north-west towards south-east. Despite changes in the thickness of the layers in the profiles, their relations within the sequence remain constant. The lowest matching ratio of thickness sequence calculated using the Pearson correlation coefficient formula is 0.67, while the highest is 0.84. The thickness of individual layers changes between 4% and 230% over the examined area. Interpretation: Layers in the outcroppings covered by the research show continuity throughout the examined area and it is possible to precisely correlate them, which means that the process determining the formation of the layers was regional and probably included both the fringe of the Holy Cross Mountains and the north-eastern part of the Krakow-Czestochowa Jura Upland. Local changes in the sedimentation environment affecting the productivity of the subtidal carbonate factory only cause the thickness of the layers to change without altering the thickness proportions of the profiles. Based on the percentage of changes in the thickness of individual layers in the subsequent profiles, it can be concluded that the local productivity of the subtidal carbonate factory is increasing logarithmically.

Keywords: Oxfordian, Holy Cross Mountains, carbonate factory, Limestone

Procedia PDF Downloads 105

Authors: Rafat Alshorman, Fadi Awawdeh

Abstract:

By employing a simplified bilinear method, a class of generalized fifth-order KdV (gfKdV) equations which arise in nonlinear lattice, plasma physics and ocean dynamics are investigated. With the aid of symbolic computation, both solitary wave solutions and multiple-soliton solutions are obtained. These new exact solutions will extend previous results and help us explain the properties of nonlinear solitary waves in many physical models in shallow water. Parametric analysis is carried out in order to illustrate that the soliton amplitude, width and velocity are affected by the coefficient parameters in the equation.

Keywords: multiple soliton solutions, fifth-order evolution equations, Cole-Hopf transformation, Hirota bilinear method

Procedia PDF Downloads 306

Authors: Markus Nordlund, Arkadiusz K. Kuczaj

Abstract:

Philip Morris International (PMI) is developing a range of novel tobacco products with the potential to reduce individual risk and population harm in comparison to smoking cigarettes. One of these products is the Tobacco Heating System 2.2 (THS 2.2), (named as the Electrically Heated Tobacco System (EHTS) in this paper), already commercialized in a number of countries (e.g., Japan, Italy, Switzerland, Russia, Portugal and Romania). During use, the patented EHTS heats a specifically designed tobacco product (Electrically Heated Tobacco Product (EHTP)) when inserted into a Holder (heating device). The EHTP contains tobacco material in the form of a porous plug that undergoes a controlled heating process to release chemical compounds into vapors, from which an aerosol is formed during cooling. The aim of this work was to investigate the aerosol formation characteristics for realistic operating conditions of the EHTS as well as for relevant gas mixture compositions measured in the EHTP aerosol consisting mostly of water, glycerol and nicotine, but also other compounds at much lower concentrations. The nucleation process taking place in the EHTP during use when operated in the Holder has therefore been modeled numerically using an extended Classical Nucleation Theory (CNT) for multicomponent gas mixtures. Results from the performed simulations demonstrate that aerosol droplets are formed only in the presence of an aerosol former being mainly glycerol. Minor compounds in the gas mixture were not able to reach a supersaturated state alone and therefore could not generate aerosol droplets from the multicomponent gas mixture at the operating conditions simulated. For the analytically characterized aerosol composition and estimated operating conditions of the EHTS and EHTP, glycerol was shown to be the main aerosol former triggering the nucleation process in the EHTP. This implies that according to the CNT, an aerosol former, such as glycerol needs to be present in the gas mixture for an aerosol to form under the tested operating conditions. To assess if these conclusions are sensitive to the initial amount of the minor compounds and to include and represent the total mass of the aerosol collected during the analytical aerosol characterization, simulations were carried out with initial masses of the minor compounds increased by as much as a factor of 500. Despite this extreme condition, no aerosol droplets were generated when glycerol, nicotine and water were treated as inert species and therefore not actively contributing to the nucleation process. This implies that according to the CNT, an aerosol cannot be generated without the help of an aerosol former, from the multicomponent gas mixtures at the compositions and operating conditions estimated for the EHTP, even if all minor compounds are released or generated in a single puff.

Keywords: aerosol, classical nucleation theory (CNT), electrically heated tobacco product (EHTP), electrically heated tobacco system (EHTS), modeling, multicomponent, nucleation

Procedia PDF Downloads 256

Authors: T. Nozu, K. Hibi, T. Nishiie

Abstract:

This paper discusses the applicability of the numerical model for a damage prediction method of the accidental hydrogen explosion occurring in a hydrogen facility. The numerical model was based on an unstructured finite volume method (FVM) code “NuFD/FrontFlowRed”. For simulating unsteady turbulent combustion of leaked hydrogen gas, a combination of Large Eddy Simulation (LES) and a combustion model were used. The combustion model was based on a two scalar flamelet approach, where a G-equation model and a conserved scalar model expressed a propagation of premixed flame surface and a diffusion combustion process, respectively. For validation of this numerical model, we have simulated the previous two types of hydrogen explosion tests. One is open-space explosion test, and the source was a prismatic 5.27 m3 volume with 30% of hydrogen-air mixture. A reinforced concrete wall was set 4 m away from the front surface of the source. The source was ignited at the bottom center by a spark. The other is vented enclosure explosion test, and the chamber was 4.6 m × 4.6 m × 3.0 m with a vent opening on one side. Vent area of 5.4 m2 was used. Test was performed with ignition at the center of the wall opposite the vent. Hydrogen-air mixtures with hydrogen concentrations close to 18% vol. were used in the tests. The results from the numerical simulations are compared with the previous experimental data for the accuracy of the numerical model, and we have verified that the simulated overpressures and flame time-of-arrival data were in good agreement with the results of the previous two explosion tests.

Keywords: deflagration, large eddy simulation, turbulent combustion, vented enclosure

Procedia PDF Downloads 230

Authors: Laura Dembovska, Diana Bajare, Ina Pundiene, Daira Erdmane

Abstract:

The aim of this research is to estimate effect of pozzolanic substitutes and their combination on the hydration heat and final strength of high performance concrete. Ternary cementitious systems with different ratios of ordinary Portland cement, silica fume and calcined clay were investigated. Local illite clay was calcined at temperature 700oC in rotary furnace for 20 min. It has been well recognized that the use of pozzolanic materials such as silica fume or calcined clay are recommended for high performance concrete for reduction of porosity, increasing density and as a consequence raising the chemical durability of the concrete. It has been found, that silica fume has a superior influence on the strength development of concrete, but calcined clay increase density and decrease size of dominating pores. Additionally it was found that the rates of pozzolanic reaction and calcium hydroxide consumption in the silica fume-blended cement pastes are higher than in the illite clay-blended cement pastes, it strongly depends from the amount of pozzolanic substitutes which are used. If the pozzolanic reaction is dominating then amount of Ca(OH)2 is decreasing. The identity and the amount of the phases present were determined from the thermal analysis (DTA) data. The hydration temperature of blended cement pastes was measured during the first 24 hours. Fresh and hardened concrete properties were tested. Compressive strength was determined and differential thermal analysis (DTA) was conducted of specimens at the age of 3, 14, 28 and 56 days.

Keywords: high performance concrete, pozzolanic additives, silica fume, ternary systems

Procedia PDF Downloads 364

Authors: R. Islam, Rafiqul A. Tarefder

Abstract:

This study investigates the effect of moisture conditioning on the Indirect Tensile Strength (ITS) of asphalt concrete. As a first step, cylindrical samples of 100 mm diameter and 50 mm thick were prepared using a Superpave gyratory compactor. Next, the samples were conditioned using Moisture Induced Susceptibility Test (MIST) device at different numbers of moisture conditioning cycles. In the MIST device, samples are subjected water pressure through the sample pores cyclically. The MIST conditioned samples were tested for ITS. Results show that the ITS does not change significantly with MIST conditioning at the specific pressure and cycles adopted in this study.

Keywords: asphalt concrete, tensile strength, moisture, laboratory test

Procedia PDF Downloads 367

Authors: Yanné Etienne

Abstract:

The current climatic conditions necessarily impose the development and use of construction materials with low or no carbon footprint. The Far North Region of Cameroon has huge deposits of termite mounds. Various tests in this work have been carried out on these soils with the aim of using them as construction materials. They are mainly geotechnical tests, physical and mechanical tests. The different tests gave the following values: uniformity coefficient (4.95), curvature coefficient (1.80), plasticity index (12.85%), optimum moisture content (6.70%), maximum dry density (2.05 g.cm-³), friction angles (14.07°), and cohesion of 100.29 kN.m2. The results obtained show that termite mound soils, which are ecological materials, are plastic and water-stable can be used for the production of load-bearing elements in construction.

Keywords: termite mound soil, ecological materials, building materials, geotechnical tests, physical and mechanical tests

Procedia PDF Downloads 173

Authors: Irma Gabriela Lopez-Moreno, Elva Perez-Luque, Herlinda Aguilar-Zavala

Abstract:

Introduction: Type 2 Diabetes Mellitus (T2DM) is characterized by combination of insulin resistance and deterioration of insulin secretion. Sfrp5 is a protein that antagonizes Wnt5a proteins by preventing it from reaching its receptor and activating the Wnt/β-catenin signaling pathway, this pathway is one of the most important regulators of adipogenesis. Although metformin decreases glucose levels its mechanisms of action are not fully known but it has been implicated in the inhibition of the Wnt/β-catenin signaling pathway. Objective: The objective was evaluating the effects of metformin on serum levels of Sfrp5 in patients with T2DM treated and not treated with metformin. Methods: Two groups of patients were selected: one group of T2DM patients treated with metformin (n = 35) and another group of subjects with recent diagnosis of T2DM untreated (n = 35) with a mean age of 48 ± 9 years. In these subjects anthropometric measures were taken as weight, height, waist and hip circumference, were calculated the percentage of body fat, visceral fat and muscle mass. In addition, were measured glucose levels, lipid profile, adiponectin and Sfrp5. Results: Sfrp5 were higher in metformin-treated patients compared to the untreated group (19.9 vs 13.6 ng/mL p < 0.001), a negative correlation was found between Sfrp5 levels and total cholesterol levels (r= -0.25, p = 0.03) and percentage of visceral fat (r = -0.26, p = 0.03) and a positive correlation with HDL cholesterol levels (r = 0.31, p = 0.01) and adiponectin (r=0.65, p = < 0.001). Conclusions: The findings show that metformin consumption increased levels of Sfrp5, which may lead to a decrease in the activation of the WNT/β-catenin pathway impacting on adipogenesis.

Keywords: adiponectin, diabetes, metformin, Sfrp5

Procedia PDF Downloads 164

Authors: Chetan Apurav

Abstract:

In this journal the behavioural analysis of pressure and velocity has been done over the blade profile of Well’s turbine. The blade profile that has been taken into consideration is NACA 0006. The analysis has been done in Ansys Workbench under CFX module. The CAD model of the blade profile with certain dimensions has been made in CREO, and then is imported to Ansys for further analysis. The turbine model has been enclosed under a cylindrical body and has been analysed under a constant velocity of air at 5 m/s and zero relative pressure in static condition of the turbine. Further the results are represented in tabular as well as graphical form. It has been observed that the relative pressure of the blade profile has been stable throughout the radial length and hence will be suitable for practical usage.

Keywords: Well's turbine, oscillating water column, ocean engineering, wave energy, NACA 0006

Procedia PDF Downloads 189

Authors: Boris Ershov

Abstract:

Depression is the most common mood disorder experienced by patients who have sustained a traumatic brain injury (TBI) and is associated with poorer cognitive functional outcomes. However, in some cases, similar cognitive impairments can also be observed in depression. There is not enough information about the features of the cognitive deficit in patients with TBI in relation to patients with depression. TBI patients without depressive symptoms (TBInD, n25), TBI patients with depressive symptoms (TBID, n31), and 28 patients with bipolar II disorder (BP) were included in the study. There were no significant differences in participants in respect to age, handedness and educational level. The patients clinical status was determined by using Montgomery–Asberg Depression Rating Scale (MADRS). All participants completed a cognitive battery (The Brief Assessment of Cognition in Affective Disorders (BAC-A)). Additionally, the Rey–Osterrieth Complex Figure (ROCF) was used to assess visuospatial construction abilities and visual memory, as well as planning and organizational skills. Compared to BP, TBInD and TBID showed a significant impairments in visuomotor abilities, verbal and visual memory. There were no significant differences between BP and TBID groups in working memory, speed of information processing, problem solving. Interference effect (cognitive inhibition) was significantly greater in TBInD and TBID compared to BP. Memory bias towards mood-related information in BP and TBID was greater in comparison with TBInD. These results suggest that depressive symptoms are associated with impairments some executive functions in combination at decrease of speed of information processing.

Keywords: bipolar II disorder, depression, neurocognitive deficits, traumatic brain injury

Procedia PDF Downloads 336

Authors: Qasim Munye, Juned Islam, Haseeb Qureshi, Syed Jung

Abstract:

Lung nodules are commonly identified in computed tomography (CT) scans by experienced radiologists at a relatively late stage. Early diagnosis can greatly increase survival. We propose using a pix2pix conditional generative adversarial network to generate realistic images simulating early-stage lung nodule growth. We have applied deep images prior to 2341 slices from 895 computed tomography (CT) scans from the Lung Image Database Consortium (LIDC) dataset to generate pseudo-healthy medical images. From these images, 819 were chosen to train a pix2pix network. We observed that for most of the images, the pix2pix network was able to generate images where the nodule increased in size and intensity across epochs. To evaluate the images, 400 generated images were chosen at random and shown to a medical student beside their corresponding original image. Of these 400 generated images, 384 were defined as satisfactory - meaning they resembled a nodule and were visually similar to the corresponding image. We believe that this generated dataset could be used as training data for neural networks to detect lung nodules at an early stage or to improve the accuracy of such networks. This is particularly significant as datasets containing the growth of early-stage nodules are scarce. This project shows that the combination of deep image prior and generative models could potentially open the door to creating larger datasets than currently possible and has the potential to increase the accuracy of medical classification tasks.

Keywords: medical technology, artificial intelligence, radiology, lung cancer

Procedia PDF Downloads 53

Authors: Amadou Darboe, Kuo Hsien-Wen

Abstract:

Background/Objective: The Effort-Reward Imbalance (ERI) model by Siegrist et al (1986) have been widely used to examine the relationship between psychosocial factors at work and health. It claimed that failed reciprocity in terms of high efforts and low rewards elicits strong negative emotions in combination with sustained autonomic activation and is hazardous to health. The aim of this study is to identify the association between Self-rated Health and Effort-reward Imbalance (ERI) among Nurses and Environmental Health officers in the Gambia. Method: a cross-sectional study was conducted using a multi-stage random sampling of 296 healthcare professionals (206 nurses and 90 environmental health officers) working in public health facilities. The 22 items Effort-reward imbalance questionnaire (ERI-L version 22.11.2012) will be used to collect data on the psychosocial factors defined by the model. In addition, self-rated health will be assessed by using structured questionnaires containing Likert scale items. Results: We found that self-rated health among environmental health officers has a significant negative correlation with extrinsic effort and a positive significant correlations with occupational reward and job satisfaction. However, among the nurses only job satisfaction was significantly correlated with self-rated health and was positive. Overall, Extrinsic effort has a significant negative correlation with reward and job satisfaction but a positive correlation with over-commitment. Conclusion: Because low reward and high over-commitment among the nursing group, It is necessary to modify working conditions through improving psychosocial factors, such as reasonable allocation of resources to increase pay or rewards from government.

Keywords: effort-reward imbalance model, healthcare professionals, self-rated health

Procedia PDF Downloads 395

Authors: Marie Davin, Marie-Laure Fauconnier, Gilles Colinet

Abstract:

In Wallonia, there are 6,000 estimated brownfields (rising to over 3.5 million in Europe) that require remediation. Polycyclic Aromatic Hydrocarbons (PAHs) are a class of recalcitrant carcinogenic/mutagenic organic compounds of major concern as they accumulate in the environment and represent 17% of all encountered pollutants. As an alternative to environmentally aggressive, expensive and often disruptive soil remediation strategies, a lot of research has been directed to developing techniques targeting organic pollutants. The following experiment, based on the observation that PAHs soil content decreases in the presence of plants, aimed at improving our understanding of the underlying mechanisms involved in phytoremediation. It focusses on plant root exudates and whether they improve PAHs solubilization, which would make them more available for bioremediation by soil microorganisms. The effect of saponin, a natural surfactant found in some plant roots such as members of the Fabaceae family, on PAHs solubilization was also investigated as part of the implementation of the experimental protocol. The experiments were conducted on soil collected from a brownfield in Saint-Ghislain (Belgium) and presenting weathered PAHs contamination. Samples of soil were extracted with different solutions containing either plant root exudates or commercial saponin. Extracted PAHs were determined in the different aqueous solutions using High-Performance Liquid Chromatography and Fluorimetric Detection (HPLC-FLD). Both root exudates of alfalfa (Medicago sativa L.) or red clover (Trifolium pratense L.) and commercial saponin were tested in different concentrations. Distilled water was used as a control. First of all, results show that PAHs are more extracted using saponin solutions than distilled water and that the amounts generally rise with the saponin concentration. However, the amount of each extracted compound diminishes as its molecular weight rises. Also, it appears that passed a certain surfactant concentration, PAHs are less extracted. This suggests that saponin might be investigated as a washing agent in polluted soil remediation techniques, either for ex-situ or in-situ treatments, as an alternative to synthetic surfactants. On the other hand, preliminary results on experiments using plant root exudates also show differences in PAHs solubilization compared to the control solution. Further results will allow discussion as to whether or not there are differences according to the exudates provenance and concentrations.

Keywords: brownfield, Medicago sativa, phytoremediation, polycyclic aromatic hydrocarbons, root exudates, saponin, solubilization, Trifolium pratense

Procedia PDF Downloads 237

Authors: Alaa Sheta

Abstract:

Economic Load Dispatch (ELD) is one of the vital optimization problems in power system planning. Solving the ELD problems mean finding the best mixture of power unit outputs of all members of the power system network such that the total fuel cost is minimized while sustaining operation requirements limits satisfied across the entire dispatch phases. Many optimization techniques were proposed to solve this problem. A famous one is the Quadratic Programming (QP). QP is a very simple and fast method but it still suffer many problem as gradient methods that might trapped at local minimum solutions and cannot handle complex nonlinear functions. Numbers of metaheuristic algorithms were used to solve this problem such as Genetic Algorithms (GAs) and Particle Swarm Optimization (PSO). In this paper, another meta-heuristic search algorithm named Differential Evolution (DE) is used to solve the ELD problem in power systems planning. The practicality of the proposed DE based algorithm is verified for three and six power generator system test cases. The gained results are compared to existing results based on QP, GAs and PSO. The developed results show that differential evolution is superior in obtaining a combination of power loads that fulfill the problem constraints and minimize the total fuel cost. DE found to be fast in converging to the optimal power generation loads and capable of handling the non-linearity of ELD problem. The proposed DE solution is able to minimize the cost of generated power, minimize the total power loss in the transmission and maximize the reliability of the power provided to the customers.

Keywords: economic load dispatch, power systems, optimization, differential evolution

Procedia PDF Downloads 267

Authors: Ami Okabe, Daisuke Gondo, Akira Ogawa, Yasuhisa Hasegawa, Koichi Sato, Sadao Araki, Hideki Yamamoto

Abstract:

Membrane separation draws attention as the energy-saving technology. Pervaporation (PV) uses hydrophobic ceramic membranes to separate organic compounds from industrial wastewaters. PV makes it possible to separate organic compounds from azeotropic mixtures and from aqueous solutions. For the PV separation of low concentrations of organics from aqueous solutions, hydrophobic ceramic membranes are expected to have high separation performance compared with that of conventional hydrophilic membranes. Membrane separation performance is evaluated based on the pervaporation separation index (PSI), which depends on both the separation factor and the permeate flux. Ingenuity is required to increase the PSI such that the permeate flux increases without reducing the separation factor or to increase the separation factor without reducing the flux. A thin separation layer without defects and pinholes is required. In addition, it is known that the flux can be increased without reducing the separation factor by reducing the diffusion resistance of the membrane support. In a previous study, we prepared hydrophobic silica membranes by a molecular templating sol−gel method using cetyltrimethylammonium bromide (CTAB) to form pores suitable for permitting the passage of organic compounds through the membrane. We separated low-concentration organics from aqueous solutions by PV using these membranes. In the present study, hydrophobic silica membranes were prepared on a porous alumina hollow fiber support that is thinner than the previously used alumina support. Ethyl acetate (EA) is used in large industrial quantities, so it was selected as the organic substance to be separated. Hydrophobic silica membranes were prepared by dip-coating porous alumina supports with a -alumina interlayer into a silica sol containing CTAB and vinyltrimethoxysilane (VTMS) as the silica precursor. Membrane thickness increases with the lifting speed of the sol in the dip-coating process. Different thicknesses of the γ-alumina layer were prepared by dip-coating the support into a boehmite sol at different lifting speeds (0.5, 1, 3, and 5 mm s-1). Silica layers were subsequently formed by dip-coating using an immersion time of 60 s and lifting speed of 1 mm s-1. PV measurements of the EA (5 wt.%)/water system were carried out using VTMS hydrophobic silica membranes prepared on -alumina layers of different thicknesses. Water and EA flux showed substantially constant value despite of the change of the lifting speed to form the γ-alumina interlayer. All prepared hydrophobic silica membranes showed the higher PSI compared with the hydrophobic membranes using the previous alumina support of hollow fiber.

Keywords: membrane separation, pervaporation, hydrophobic, silica

Procedia PDF Downloads 390

Authors: G. E. Sharaf El-Deen, S. E. A. Sharaf El-Deen

Abstract:

Activated carbon was prepared from coconut shell (ACS); a discarded agricultural waste was used to produce bioadsorbent through easy and environmental friendly processes. This activated carbon based biosorbent was evaluated for adsorptive removal of lead from water. The characterisation results showed this biosorbent had very high specific surface area and functional groups. The adsorption equilibrium data was well described by Langmuir, whilst kinetics data by pseudo-first order, pseudo-second order and Intraparticle diffusion models. The adsorption process could be described by the pseudo-second order kinetic.

Keywords: coconut shell, activated carbon, adsorption isotherm and kinetics, lead removal

Procedia PDF Downloads 290

Authors: M. Lebrini, L. Salhi, C. Deyrat, C. Roos, O. Nait-Rabah

Abstract:

The paper presents a large experimental study on the corrosion of zinc in tropical soil and in the ground water at the various depths. Through this study, the corrosion rate prediction was done on the basis of two methods the electrochemical method and the gravimetric. The electrochemical results showed that the corrosion rate is more important at the depth levels 0 m to 0.5 m and 0.5 m to 1 m and beyond these depth levels, the corrosion rate is less important. The electrochemical results indicated also that a passive layer is formed on the zinc surface. The found SEM and EDX micrographs displayed that the surface is extremely attacked and confirmed that a zinc oxide layer is present on the surface whose thickness and relief increase as the contact with soil increases.

Keywords: soil corrosion, galvanized steel, electrochemical technique, SEM and EDX

Procedia PDF Downloads 110

Authors: Marianne Miguet, Gaël Plantard, Yves Jaeger, Vincent Goetz

Abstract:

The contamination of groundwater is a major concern. A common pollutant, the perchloroethylene, is the target contaminant. Water treatment process as Granular Activated Carbons are very efficient but requires pilot-scale testing to determine the full-scale GAC performance. First, the batch mode was used to get a reliable experimental method to estimate the adsorption capacity of a common volatile compound is settled. The Langmuir model is acceptable to fit the isotherms. Dynamic tests were performed with three columns and different operating conditions. A database of concentration profiles and breakthroughs were obtained. The resolution of the set of differential equations is acceptable to fit the dynamics tests and could be used for a full-scale adsorber.

Keywords: activated carbon, groundwater, perchloroethylene, full-scale

Procedia PDF Downloads 413

Authors: Nada Al-Qallaf, Aisha Al-Barood, Djamel Lekmine, Srinivasan Vedhapuri

Abstract:

Kuwait Oil Company (KOC) under the supervision of Kuwait National Focal Point (KNFP) is planning to remediate 26 million (M) m3 of oil-contaminated soil in oil fields of Kuwait as a direct and indirect fallout of the Gulf War during 1990-1991. This project is funded by the United Nations Compensation Commission (UNCC) under the Kuwait Environmental Remediation Program (KERP). Oil-contamination of the soil occurred due to the destruction of the oil wells and spilled crude oil across the land surface and created ‘oil lakes’ in low lying land. Aerial fall-out from oil spray and combustion products from oil fires combined with the sand and gravel on the ground surface to form a layer of hardened ‘Tarcrete’. The unique fresh groundwater lenses present in the Raudhatain and Sabriya subsurface areas had been impacted by the discharge and/or spills of dissolved petroleum constituents. These fresh groundwater aquifers were used for drinking water purposes until 1990, prior to invasion. This has significantly damages altered the landscape, ecology and habitat of the flora and fauna and in Kuwait Desert. Under KERP, KOC is fully responsible for the planning and execution of the remediation and restoration projects in KOC oil fields. After the initial recommendation of UNCC to construct engineered landfills for containment and disposal of heavily contaminated soils, two landfills were constructed, one in North Kuwait and another in South East Kuwait of capacity 1.7 million m3 and 0.5 million m3 respectively. KOC further developed the Total Remediation Strategy in conjunction with KNFP and has obtained UNCC approval. The TRS comprises of elements such as Risk Based Approach (RBA), Bioremediation of low Contaminated Soil levels, Remediation Treatment Technologies, Sludge Disposal via Beneficial Recycling or Re-use and Engineered landfills for Containment of untreatable materials. Risk Based Assessment as a key component to avoid any unnecessary remedial works, where it can be demonstrated that human health and the environment are sufficiently protected in the absence of active remediation. This study demonstrates on the risks of tarcrete materials spread over areas 20 Km2 on the fresh Ground water lenses/catchment located beneath the Sabriyah and Raudhatain oil fields in North Kuwait. KOC’s primary objective is to provide justification of using RBA, to support a case with the Kuwait regulators to leave the tarcrete material in place, rather than seek to undertake large-scale removal and remediation. The large-scale coverage of the tarcrete in the oil fields and perception that the residual contamination associated with this source is present in an environmentally sensitive area essentially in ground water resource. As part of this assessment, conceptual site model (CSM) and complete risk-based and fate and transport modelling was carried out which includes derivation of site-specific assessment criteria (SSAC) and quantification of risk to identified waters resource receptors posed by tarcrete impacted areas. The outcome of this assessment was determined that the residual tarcrete deposits across the site area shall not create risks to fresh groundwater resources and the remedial action to remove and remediate the surficial tarcrete deposits is not warranted.

Keywords: conceptual site model, fresh groundwater, oil-contaminated soil, tarcrete, risk based assessment

Procedia PDF Downloads 168

Authors: Dipranjan Laha, Parimal Karmakar

Abstract:

Metal oxide nanoparticles are well known to generate oxidative stress and deregulate normal cellular activities. Among these, transition metals copper oxide nanoparticles (CuO NPs) are more compelling than others and able to modulate different cellular responses. In this work, we have synthesized and characterized CuO NPs by various biophysical methods. These CuO NPs (~30 nm) induce autophagy in human breast cancer cell line, MCF7 in a time and dose-dependent manner. Cellular autophagy was tested by MDC staining, induction of green fluorescent protein light chain 3 (GFP-LC3B) foci by confocal microscopy, transfection of pBABE-puro mCherry-EGFP-LC3B plasmid and western blotting of autophagy marker proteins LC3B, beclin1, and ATG5. Further, inhibition of autophagy by 3-Methyladenine (3-MA) decreased LD50 doses of CuO NPs. Such cell death was associated with the induction of apoptosis as revealed by FACS analysis, cleavage of PARP, dephosphorylation of Bad and increased cleavage product of caspase3. siRNA-mediated inhibition of autophagy-related gene beclin1 also demonstrated similar results. Finally, induction of apoptosis by 3-MA in CuO NPs treated cells were observed by TEM. This study indicates that CuO NPs are a potent inducer of autophagy which may be a cellular defense against the CuO NPs mediated toxicity and inhibition of autophagy switches the cellular response into apoptosis. A combination of CuO NPs with the autophagy inhibitor is essential to induce apoptosis in breast cancer cells. Acknowledgments: The authors would like to acknowledge for financial support for this research work to the Department of Biotechnology (No. BT/PR14661/NNT/28/494/2010), Government of India.

Keywords: nanoparticle, autophagy, apoptosis, siRNA-mediated inhibition

Procedia PDF Downloads 429

Authors: Evangelos Tsakalos, Maria Kazantzaki, Eleni Filippaki, Yannis Bassiakos

Abstract:

The coastal areas of the Mediterranean have been extensively affected by the transgressive event that followed the Last Glacial Maximum, with many studies conducted regarding the stratigraphic configuration of coastal sediments around the Mediterranean. The coastal zone of the Messologi area, western Greece, consists of low relief beaches containing low cliffs and eroded dunes, a fact which, in combination with the rising sea level and tectonic subsidence of the area, has led to substantial coastal. Coastal vulnerability assessment is a useful means of identifying areas of coastline that are vulnerable to impacts of climate change and coastal processes, highlighting potential problem areas. Commonly, coastal vulnerability assessment takes the form of an ‘index’ that quantifies the relative vulnerability along a coastline. Here we make use of the coastal vulnerability index (CVI) methodology by Thieler and Hammar-Klose, by considering geological features, coastal slope, relative sea-level change, shoreline erosion/accretion rates, and mean significant wave height as well as mean tide range to assess the present-day vulnerability of the coastal zone of Messologi area. In light of this, an impact assessment is performed under three different sea level rise scenarios, and adaptation measures to control climate change events are proposed. This study contributes toward coastal zone management practices in low-lying areas that have little data information, assisting decision-makers in adopting best adaptations options to overcome sea level rise impact on vulnerable areas similar to the coastal zone of Messologi.

Keywords: coastal vulnerability index, coastal erosion, sea level rise, GIS

Procedia PDF Downloads 164

Authors: Sulhee Lee, Geon Kim, Young-Seo Park

Abstract:

Unlike the traditional milk sterilization methods (LTLT, HTST, or UHT), pulsed electric field (PEF) technology is a non-thermal pasteurization process. This technology minimizes energy required for heat treatment in food processing, changes in sensory properties, and physical losses. In this study, structural changes of bovine milk proteins, the amount of immunoproteins such as IgG, and their storability by PEF treatment were examined. When the changes of protein content in PEF-treated milk were examined using HPLC, the amounts of α-casein and β-lactoglobulin were reduced over 40% each, whereas those of κ-casein and β-casein did not change. The amount of α-casein in HTST milk was reduced to 50%. When PEF was applied to milk at the energy level of 250 kJ, the amounts of IgG, IgA, β-lactoglobulin (β-LG), lactoferrin, and α-lactalbumin (α-LA) decreased by 43, 41, 35, 63, and 45%, respectively. When milk was sterilized by LTLT process followed by PEF process at the level of 150 kJ, the concentrations of IgG, IgA, β-LG, lactoferrin, and α-LA were 56.6, 10.6, 554, 2.8 and 660.1 μg/mL, respectively. When the bovine milk was sterilized by LTLT process followed by PEF process at the energy level of 180 kJ, storability of immunoproteins of milk was the highest and the concentrations of IgG, IgA, and β-LG decreased by 79.5, 6.5, and 134.5 μg/mL, respectively, when compared with the initial concentrations of those proteins. When bovine milk was stored at 4℃ after sterilization through HTST sterilizer followed by PEF process at the energy level of 200 kJ, the amount of lactoferrin decreased 7.3% after 36 days of storage, whereas that of lactoferrin of raw milk decreased 16.4%. Our results showed that PEF treatment did not change the protein structure nor induce protein denaturation in milk significantly when compared with LTLT or HTST sterilization. Also, LTLT or HTST process in combination with PEF were more effective than LTLT only or HTST only process in the conservation of immunoproteins in bovine milk.

Keywords: pulsed electric field, bovine milk, immunoproteins, sterilization

Procedia PDF Downloads 426

Authors: P. Chaijak, M. Lertworapreecha, C. Sukkasem

Abstract:

A huge of dark color palm oil mill effluent (POME) cannot pass the discharge standard. It has been identified as the major contributor to the pollution load into ground water. Here, lignin-degrading yeast isolated from a termite nest was tested to treat the POME. Its lignin-degrading and decolorizing ability was determined. The result illustrated that Galactomyces sp. was successfully grown in POME. The decolorizing test demonstrated that 40% of Galactomyces sp. could reduce the color of POME (50% v/v) about 74-75% in 5 days without nutrient supplement. The result suggested that G. reessii has a potential to apply for decolorizing the dark wastewater like POME and other industrial wastewaters.

Keywords: decolorization, palm oil mill effluent, termite, yeast

Procedia PDF Downloads 193

Authors: Ioannis Boutas, Vasilios Pergialiotis, Nicolaos Salakos, George Agrogiannis, Panagiotis Konstantopoulos, Laskarina-Maria Korou, Theodoros Kalampokas, Odysseas Gregoriou, George Creatsas, Despina Perrea

Abstract:

Introduction: The effect of third generation aromatase inhibitors in the lipid profile among women with breast cancer, present diversities. It has been also shown that low levels of estrogens affect liver metabolism in mice in numerous ways, such as lipid accumulation and hepatic steatosis. Materials and Methods: Forty-five female Wistar rats underwent surgical ovariectomy. The animals were anesthetized with a combination of ketamine (75 mg/kg) and xylazine (10 mg/kg) which were administered intraperitoneally. After the ovariectomy, the operated animals were randomized in three groups. The first group did not receive any drug regimen (ovariectomized control group). The second group received Anastrazole and the third group received Letrozole. Four months after the initiation of the study, the animals were euthanized and livers were dissected immediately for further histopathological analysis. The histological features were grouped into 4 broad categories: steatosis, ballooning, portal inflammation and lobular activity. A score from 0 (absence) to 3 (severe) was assigned to each parameter. Results: The liver pathology analysis revealed significant differences among groups with favored mild steatosis and ballooning among animals that received Anastrazole or Letrozole. Conclusion: The effect of Anastrazole and Letrozole on liver function have not yet been clarified. In our study mild histological liver alterations seem also to occur and these alterations should be taken in mind in future clinical studies

Keywords: anastrazole, letrozole, liver, rats

Procedia PDF Downloads 332

Authors: Mohamad Saberi, Arash Sohrabi

Abstract:

Tuned liquid damper is one the passive structural control ways which has been used since mid-1980 decade for seismic control in civil engineering. This system is made of one or many tanks filled with fluid, mostly water that installed on top of the high raised structure and used to prevent structure vibration. In this article we will show how to make seismic table contain TLD system and analysis the result of using this system in our structure. Results imply that when frequency ratio approaches 1 this system can perform its best in both dissipate energy and increasing structural damping. And also results of these serial experiments are proved compatible with Hunzer linear theory behaviour.

Keywords: TLD, seismic table, structural system, Hunzer linear behaviour

Procedia PDF Downloads 364

Authors: Mariusz Hofman

Abstract:

The paper ‘Theoretical framework for value creation in Project-Oriented Companies’ is designed to determine, how organisations create value and whether this allows them to achieve market success. An assumption has been made that there are two routes to achieving this value. The first one is to create intangible assets (i.e. the resources of human, structural and relational capital), while the other one is to create added value (understood as the surplus of revenue over costs). It has also been assumed that the combination of the achieved added value and unique intangible assets translates to the success of a project-oriented company. The purpose of the paper is to present hypothetical and deductive model which describing the modus operandi of such companies and approach to model operationalisation. All the latent variables included in the model are theoretical constructs with observational indicators (measures). The existence of a latent variable (construct) and also submodels will be confirmed based on a covariance matrix which in turn is based on empirical data, being a set of observational indicators (measures). This will be achieved with a confirmatory factor analysis (CFA). Due to this statistical procedure, it will be verified whether the matrix arising from the adopted theoretical model differs statistically from the empirical matrix of covariance arising from the system of equations. The fit of the model with the empirical data will be evaluated using χ2, RMSEA and CFI (Comparative Fit Index). How well the theoretical model fits the empirical data is assessed through a number of indicators. If the theoretical conjectures are confirmed, an interesting development path can be defined for project-oriented companies. This will let such organisations perform efficiently in the face of the growing competition and pressure on innovation.

Keywords: value creation, project-oriented company, structural equation modelling

Procedia PDF Downloads 269

Authors: Emmanuel Kamal Aziz Saba

Abstract:

Aim of the work: This study proposed to assess the role of the median versus ulnar medial thenar motor (MTM) recording in supporting the diagnosis of carpal tunnel syndrome (CTS). Patients and methods: The present study included 130 hands (70 CTS and 60 controls). Clinical examination was done for all patients. The following tests were done (using surface electrodes recording) for patients and control: (1) sensory nerve conduction studies: median nerve, ulnar nerve and median versus ulnar digit four sensory study; (2) motor nerve conduction studies: median nerve, ulnar nerve, median (second lumbrical) versus ulnar (interosseous) (2-LINT) motor study and median versus ulnar (MTM) study. Results: The tests with higher sensitivity in diagnosing CTS were median versus ulnar (2-LINT) motor latency difference (87.1%), median versus ulnar (MTM) motor latency difference (80%) and median versus ulnar digit four sensory latency differences (91.4%). There was no statistically significant difference between median versus ulnar (MTM) motor latency difference with both median versus ulnar (2-LINT) motor latency difference and median versus ulnar digit four sensory latency difference (P > 0.05) as regards the confirmation of CTS. Conclusions: Median versus ulnar (MTM) motor latency difference has high sensitivity and specificity for the diagnosis of CTS as for both median versus ulnar (2-LINT) motor latency difference and median versus ulnar digit four sensory latency differences. It can be considered a useful neurophysiological test to be used in combination with another median versus ulnar comparative tests for confirming the diagnosis of CTS beside other well-known electrophysiological tests.

Keywords: carpal tunnel syndrome, medial thenar motor, median nerve, ulnar nerve

Procedia PDF Downloads 430