Search results for: salt concentration

Authors: Ahmad Shah Farhat, Anahita Alizadeh Qamsari, Ashraf Mohammadzadeh, Hamid Reza Goldouzian, Ezat Khodashenas

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Introduction: Newborns may be treated with phenobarbital for many reasons. Because in each region, depending on different races and genetic factors, different pharmacokinetic conditions govern the drug. It is essential to control blood levels of certain drugs, especially phenobarbital, and maintain these levels during treatment. Methods: In this study, venous blood was collected from 50 neonates who received intravenous phenobarbital at a loading dose of 20 mg/kg weight and at least three days had passed since the maintenance dose of 5 mg/kg body weight. in 24 hours. and sent to the laboratory. Phenobarbital blood levels were measured, then the results were analyzed descriptively. Results: In this study, the average weight of newborns was 9.93 ± 2.58. The mean blood concentration of phenobarbital, three days after starting the maintenance dose in the group of infants weighing more than 2.5 kg, was 3.33 ± 9.1 micrograms/liter in the group of infants weighing less than 2 kg. and half a kilogram or LBW was 5.9 ± 9.5 micrograms/liter and in the group weighing less than 1.5 kg VLBW was 14.4 ± 15.46 micrograms/liter. There was no significant difference between groups (p>0.05). Three days after starting the maintenance dose in all three groups, the mean blood phenobarbital concentration was 9.86 ± 0.86 micrograms/liter. Conclusion: Blood phenobarbital levels in our newborns are below therapeutic levels, so phenobarbital levels should be evaluated.

Keywords: poisining, neonats, phenobarbital, drug

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Authors: Mohammed Alasel, Michael Keusgen

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Gold is a noble metal; in its nano-scale level (e.g. spherical nanoparticles), the conduction electrons are triggered to collectively oscillate with a resonant frequency when certain wavelengths of electromagnetic radiation interact with its surface; this phenomenon is known as surface plasmon resonance (SPR). SPR is responsible for giving the gold nanoparticles its intense red color depending mainly on its size, shape and distance between nanoparticles. A decreased distance between gold nanoparticles results in aggregation of them causing a change in color from red to blue. This aggregation enables gold nanoparticles to serve as a sensitive biosensoric indicator. In the proposed work, gold nanoparticles were modified with two proteins: i) Borrelia antigen, variable lipoprotein surface-exposed protein (VlsE), and ii) protein A. VlsE antigen induces a strong antibody response against Lyme disease and can be detected from early to late phase during the disease in humans infected with Borrelia. In addition, it shows low cross-reaction with the other non-pathogenic Borrelia strains. The high specificity of VlsE antigen to anti-Borrelia antibodies, combined simultaneously with the high specificity of protein A to the Fc region of all IgG human antibodies, was utilized to develop a rapid test for serological point of care diagnosis of borreliosis in human serum. Only in the presence of anti-Borrelia antibodies in the serum probe, an aggregation of gold nanoparticles can be observed, which is visible by a concentration-dependent colour shift from red (low IgG) to blue (high IgG). Experiments showed it is clearly possible to distinguish between positive and negative sera samples using a simple suspension of the two-protein modified gold nanoparticles in a very short time (30 minutes). The proposed work showed the potential of using such modified gold nanoparticles generally for serological diagnosis. Improved specificity and reduced assay time can be archived in applying increased salt concentrations combined with decreased pH values (pH 5).

Keywords: gold nanoparticles, gold aggregation, serological diagnosis, protein A, lyme borreliosis

Procedia PDF Downloads 374

Authors: A. Bayat, R. Bello-Mendoza, D. G. Wareham

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Two major categories of green waste are fruit and vegetable (FV) waste and garden and yard (GY) waste. Although, anaerobic digestions (AD) is able to manage FV waste; there is less confidence in the conditions for AD to handle GY wastes (grass, leaves, trees and bush trimmings); mainly because GY contains lignin and other recalcitrant organics. GY in the dry state (TS ≥ 15 %) can be digested at mesophilic temperatures; however, little methane data has been reported under thermophilic conditions, where conceivably better methane yields could be achieved. In addition, it is suspected that at lower solids concentrations, the methane yield could be increased. As such, the aim of this research is to find the temperature and solids concentration conditions that produce the most methane; under two different temperature regimes (mesophilic, thermophilic) and three solids states (i.e. 'dry', 'semi-dry' and 'wet'). Twenty liters of GY waste was collected from a public park located in the northern district in Tehran. The clippings consisted of freshly cut grass as well as dry branches and leaves. The GY waste was chopped before being fed into a mechanical blender that reduced it to a paste-like consistency. An initial TS concentration of approximately 38 % was achieved. Four hundred mL of anaerobic inoculum (average total solids (TS) concentration of 2.03 ± 0.131 % of which 73.4% were volatile solid (VS), soluble chemical oxygen demand (sCOD) of 4.59 ± 0.3 g/L) was mixed with the GY waste substrate paste (along with distilled water) to achieve a TS content of approximately 20 %. For comparative purposes, approximately 20 liters of FV waste was ground in the same manner as the GY waste. Since FV waste has a much higher natural water content than GY, it was dewatered to obtain a starting TS concentration in the dry solid-state range (TS ≥ 15 %). Three samples were dewatered to an average starting TS concentration of 32.71 %. The inoculum was added (along with distilled water) to dilute the initial FV TS concentrations down to semi-dry conditions (10-15 %) and wet conditions (below 10 %). Twelve 1-L batch bioreactors were loaded simultaneously with either GY or FV waste at TS solid concentrations ranging from 3.85 ± 1.22 % to 20.11 ± 1.23 %. The reactors were sealed and were operated for 30 days while being immersed in water baths to maintain a constant temperature of 37 ± 0.5 °C (mesophilic) or 55 ± 0.5 °C (thermophilic). A maximum methane yield of 115.42 (L methane/ kg VS added) was obtained for the GY thermophilic-wet AD combination. Methane yield was enhanced by 240 % compared to the GY waste mesophilic-dry condition. The results confirm that high temperature regimes and small solids concentrations are conditions that enhance methane yield from GY waste. A similar trend was observed for the anaerobic digestion of FV waste. Furthermore, a maximum value of VS (53 %) and sCOD (84 %) reduction was achieved during the AD of GY waste under the thermophilic-wet condition.

Keywords: anaerobic digestion, thermophilic, mesophilic, total solids concentration

Procedia PDF Downloads 117

Authors: Irnie Zakaria, W. A. N. W. Mohamed, W. H. Azmi

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Thermal enhancement of a single mini channel in Proton Exchange Membrane Fuel Cell (PEMFC) cooling plate is numerically investigated. In this study, low concentration of Al2O3 in Water - Ethylene Glycol mixtures is used as coolant in mini channel of carbon graphite plate to mimic the PEMFC cooling plate. A steady and incompressible flow with constant heat flux is assumed in the channel of 1mm x 5mm x 100mm. Nano particle of Al2O3 used ranges from 0.1, 0.3 and 0.5 vol % concentration and then dispersed in 60:40 (water: Ethylene Glycol) mixture. The effect of different flow rates to fluid flow and heat transfer enhancement in Re number range of 20 to 140 was observed. The result showed that heat transfer coefficient was improved by 18.11%, 9.86% and 5.37% for 0.5, 0.3 and 0.1 vol % Al2O3 in 60:40 (water: EG) as compared to base fluid of 60:40 (water: EG). It is also showed that the higher vol % concentration of Al2O3 performed better in term of thermal enhancement but at the expense of higher pumping power required due to increase in pressure drop experienced. Maximum additional pumping power of 0.0012W was required for 0.5 vol % Al2O3 in 60:40 (water: EG) at Re number 140.

Keywords: heat transfer, mini channel, nanofluid, PEMFC

Procedia PDF Downloads 323

Authors: P. M. G. Pathiraja, P. Egodawatta, A. Goonetilleke, V. S. J. Te'o

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The production and use of Polychlorinated biphenyls (PCBs), a group of synthetic halogenated hydrocarbons have been restricted worldwide due to its toxicity and categorized as one of the twelve priority persistent organic pollutants (POP) by the Stockholm Convention. Low reactivity and high chemical stability of PCBs have made them highly persistent in the environment and bio-concentration and bio-magnification along the food chain contribute to multiple health impacts in humans and animals. Remediating environments contaminated with PCBs is a challenging task for decades. Use of microorganisms for remediation of PCB contaminated soils and sediments have been widely investigated due to the potential of breakdown these complex contaminants with minimum environmental impacts. To achieve an effective bioremediation of polychlorinated biphenyls (PCBs) contaminated environments, microbes were sourced from environmental samples and tested for their ability to hydrolyze PCBs under different conditions. Comparison of PCB degradation efficiencies of four naturally occurring facultative bacterial cultures isolated through selective enrichment under aerobic and anaerobic conditions were simultaneously investigated in minimal salt medium using 50 mg/L Aroclor 1260, a commonly used commercial PCB mixture as the sole source of carbon. The results of a six-week study demonstrated that all the tested facultative Achromobacter, Ochrobactrum, Lysinibacillus and Pseudomonas strains are capable of degrading PCBs under both anaerobic and aerobic conditions while assisting hydrophobic PCBs to make solubilize in the aqueous minimal medium. Overall, the results suggest that some facultative bacteria are capable of effective in degrading PCBs under anaerobic conditions through reductive dechlorination and under aerobic conditions through oxidation. Therefore, use of suitable facultative microorganisms under combined anaerobic-aerobic conditions and combination of such strains capable of solubilization and breakdown of PCBs has high potential in achieving higher PCB removal rates.

Keywords: bioremediation, combined anaerobic-aerobic degradation, facultative microorganisms, polychlorinated biphenyls

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Authors: Oluwole Opeyemi Dina, Saheed E. Elugoke, Peter Olutope Fayemi, Omolola E. Fayemi

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This study presents the detection of epinephrine (EP) at Fe₃O₄ modified screen printed silver electrode (SPSE). The iron oxide (Fe₃O₄) nanoparticles were characterized with UV-visible spectroscopy, Fourier-Transform infrared spectroscopy (FT-IR) and Scanning electron microscopy (SEM) prior to the modification of the SPSE. The EP oxidation peak current (Iap) increased with an increase in the concentration of EP as well as the scan rate (from 25 - 400 mVs⁻¹). Using cyclic voltammetry (CV), the relationship between Iap and EP concentration was linear over a range of 3.8 -118.9 µM and 118.9-175 µM with a detection limit of 41.99 µM and 83.16 µM, respectively. Selective detection of EP in the presence of ascorbic acid was also achieved at this electrode.

Keywords: screenprint electrode, iron oxide nanoparticle, epinephrine, serum, cyclic voltametry

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Authors: L. Mouzai, M. Bouhadef

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Raindrops and overland flow both are erosive parameters but they do not act by the same way. The overland flow alone tends to shear the soil horizontally and concentrates into rills. In the presence of rain, the soil particles are removed from the soil surface in the form of a uniform sheet layer. In addition to this, raindrops falling on the flow roughen the water and soil surface depending on the flow depth, and retard the velocity, therefore influence shear velocity and Manning’s factor. To investigate this part, agricultural sandy soil, rainfall simulator and a laboratory soil tray of 0.2x1x3 m were the base of this work. Five overland flow depths of 0; 3.28; 4.28; 5.16; 5.60; 5.80 mm were generated under a rainfall intensity of 217.2 mm/h. Sediment concentration control is based on the proportionality of depth/microtopography. The soil loose is directly related to the presence of rain splash on thin sheet flow. The effect of shear velocity on sediment concentration is limited by the value of 5.28 cm/s. In addition to this, the rain splash reduces the soil roughness by breaking the soil crests. The rainfall intensity is the major factor influencing depth and soil erosion. In the presence of rainfall, the shear velocity of the flow is due to two simultaneous effects. The first, which is horizontal, comes from the flow and the second, vertical, is due to the raindrops.

Keywords: flow resistance, laboratory experiments, rainfall simulator, sediment concentration, shear velocity, soil erosion

Procedia PDF Downloads 179

Authors: A.D. Susanti, W. B. Sediawan, S.K. Wirawan, Budhijanto, Ritmaleni

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Oryzanol content in rice bran oil (RBO) naturally has high antioxidant activity. Its reviewed has several health properties and high interested in pharmacy, cosmetics, and nutrition’s. Because of the low concentration of oryzanol in crude RBO (0.9-2.9%) then its need to be further processed for practical usage, such as via adsorption process. In this study, investigation and adjustment of adsorption equilibrium models were conducted through the kinetic data approachments. Mathematical modeling on kinetics of batch adsorption of oryzanol separation from RBO has been set-up and then applied for equilibrium results. The size of adsorbent particles used in this case are usually relatively small then the concentration in the adsorbent is assumed to be not different. Hence, the adsorption rate is controlled by the rate of oryzanol mass transfer from the bulk fluid of RBO to the surface of silica gel. In this approachments, the rate of mass transfer is assumed to be proportional to the concentration deviation from the equilibrium state. The equilibrium models applied were Langmuir, coefficient distribution, and Freundlich with the values of the parameters obtained from equilibrium results. It turned out that the models set-up can quantitatively describe the experimental kinetics data and the adjustment of the values of equilibrium isotherm parameters significantly improves the accuracy of the model. And then the value of mass transfer coefficient per unit adsorbent mass (kca) is obtained by curve fitting.

Keywords: adsorption equilibrium, adsorption kinetics, oryzanol, rice bran oil

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Authors: Bin Wang, Yong Xu, Honggang Qu, Rongmei Liu, Zhenji Gao

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Based on the geodynamic environment, basic geological characteristics of minerals and so on, gold deposits in China are divided into 11 categories, of which tectonic fracture altered rock, mid-intrudes and contact zone, micro-fine disseminated and continental volcanic types are the main prospecting kinds. The metallogenic age of gold deposits in China is dominated by the Mesozoic and Cenozoic. According to the geotectonic units, geological evolution, geological conditions, spatial distribution, gold deposits types, metallogenic factors etc., 42 gold concentration areas are initially determined and have a concentrated distribution feature. On the basis of the gold exploration density, gold concentration areas are divided into high, medium and low level areas. High ones are mainly distributed in the central and eastern regions. 93.04% of the gold exploration drillings are within 500 meters, but there are some problems, such as less and shallower of drilling verification etc.. The paper discusses the resource potentials of gold deposits and proposes the future prospecting directions and suggestions. The deep and periphery of old mines in the central and eastern regions and western area, especially in Xinjiang and Qinghai, will be the future key prospecting one and have huge potential gold reserves. If the exploration depth is extended to 2,000 meters shallow, the gold resources will double.

Keywords: gold deposits, gold deposits types, gold concentration areas, prospecting, resource potentiality

Procedia PDF Downloads 57

Authors: M. Muneer, Waseem Raza

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Nano-crystalline materials of pure and metal-doped semiconducting materials have been successfully synthesized using sol gel and hydrothermal methods. The prepared materials were characterized by standard analytical techniques, i.e., XRD, SEM, EDX, UV–vis Spectroscopy and FTIR. The (XRD) analysis showed that the obtained particles are present in partial crystalline nature and exhibit no other impurity phase. The EDX and (SEM) images depicted that metals have been successfully loaded on the surface of the semiconductor. FTIR showed an additional absorption band at 910 cm−1, characteristic of absorption band indicating the incorporation of dopant into the lattice in addition to a broad and strong absorption band in the region of 410–580 cm−1 due to metal–O stretching. The UV–vis absorption spectra of synthesized particles indicate that the doping of metals into the lattice shift the absorption band towards the visible region. Thermal analysis, measurement of the synthesized sample showed that the thermal stability of pure semiconducting material is decreased due to increase in dopant concentration. The photocatalytic activity of the synthesized particles was studied by measuring the change in concentration of three different chromophoric dyes as a function of irradiation time. The photocatalytic activity of doped materials were found to increase with increase in dopant concentration.

Keywords: photocatalysis, metal doped semicondcutors, dye degradation, visible light active materials

Procedia PDF Downloads 421

Authors: Pranitha Janapatla, Venkata Suman Gontla

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The present paper investigates the effects of MHD, double dispersion and variable properties on mixed convection flow from a vertical surface in a power-law fluid saturated non-Darcy porous medium. The governing non-linear partial differential equations are reduced to a system of ordinary differential equations by using a special form of Lie group transformations viz. scaling group of transformations. These ordinary differential equations are solved numerically by using Shooting technique. The influence of relevant parameters on the non-dimensional velocity, temperature, concentration for pseudo-plastic fluid, Newtonian and dilatant fluid are discussed and displayed graphically. The behavior of heat and mass transfer coefficients are shown in tabular form. Comparisons with the published works are performed and are found to be in very good agreement. From this analysis, it is observed that an increase in variable viscosity causes to decrease in velocity profile and increase the temperature and concentration distributions. It is also concluded that increase in the solutal dispersion decreases the velocity and concentration but raises the temperature profile.

Keywords: power-law fluid, thermal conductivity, thermal dispersion, solutal dispersion, variable viscosity

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Authors: S. Mowafi, A. Abou El-Kheir, M. Abou Taleb, H. El-Sayed

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Two proteinic biopolymers; namely keratin and sericin, were extracted from their respective natural resources by simple appropriate methods. The said proteins were dissolved in the appropriate solvents followed by regeneration in a form of film polyvinyl alcohol. Protein-starch-potassium iodide (PSPI) composite was prepared by anchoring starch and potassium iodide mixture onto the film surface using appropriate polymeric material. The possibility of using PSPI composite for determination of the concentration of chlorine ions in domestic as well as industrial water was examined. The concentration of chlorine in water was determined spectrophotometrically by measuring the intensity of blue colour of formed between starch and the released iodine obtained by interaction of potassium iodide chlorine in the tested water sample.

Keywords: chlorine, protein, potassium iodide, water

Procedia PDF Downloads 356

Authors: Muhammad Waleed Asfandyar, Akhtar Ahmed, Syed Adib-ul-Hasan Rizvi

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Objective: To evaluate the ability of serum concentration of prostate specific antigen between two cutting points considering it as a predictor of skeletal metastasis on bone scintigraphy in men with prostate cancer. Settings: This study was carried out in department of Nuclear Medicine at Sindh Institute of Urology and Transplantation (SIUT) Karachi, Pakistan. Materials and Method: From August 2013 to November 2013, forty two (42) consecutive patients with prostate cancer who underwent technetium-99m methylene diphosphonate (Tc-99mMDP) whole body bone scintigraphy were prospectively analyzed. The information was collected from the scintigraphic database at a Nuclear medicine department Sindh institute of urology and transplantation Karachi Pakistan. Patients who did not have a serum PSA concentration available within 1 month before or after the time of performing the Tc-99m MDP whole body bone scintigraphy were excluded from this study. A whole body bone scintigraphy scan (from the toes to top of the head) was performed using a whole-body Moving gamma camera technique (anterior and posterior) 2–4 hours after intravenous injection of 20 mCi of Tc-99m MDP. In addition, all patients necessarily have a pathological report available. Bony metastases were determined from the bone scan studies and no further correlation with histopathology or other imaging modalities were performed. To preserve patient confidentiality, direct patient identifiers were not collected. In all the patients, Prostate specific antigen values and skeletal scintigraphy were evaluated. Results: The mean age, mean PSA, and incidence of bone metastasis on bone scintigraphy were 68.35 years, 370.51 ng/mL and 19/42 (45.23%) respectively. According to PSA levels, patients were divided into 5 groups < 10ng/mL (10/42), 10-20 ng/mL (5/42), 20-50 ng/mL (2/42), 50-100 (3/42), 100- 500ng/mL (3/42) and more than 500ng/mL (0/42) presenting negative bone scan. The incidence of positive bone scan (%) for bone metastasis for each group were O1 patient (5.26%), 0%, 03 patients (15.78%), 01 patient (5.26%), 04 patients (21.05%), and 10 patients (52.63%) respectively. From the 42 patients 19 (45.23%) presented positive scintigraphic examination for the presence of bone metastasis. 1 patient presented bone metastasis on bone scintigraphy having PSA level less than 10ng/mL, and in only 1 patient (5.26%) with bone metastasis PSA concentration was less than 20 ng/mL. therefore, when the cutting point adopted for PSA serum concentration was 10ng/mL, a negative predictive value for bone metastasis was 95% with sensitivity rates 94.74% and the positive predictive value and specificities of the method were 56.53% and 43.48% respectively. When the cutting point of PSA serum concentration was 20ng/mL the observed results for Positive predictive value and specificity were (78.27% and 65.22% respectively) whereas negative predictive value and sensitivity stood (100% and 95%) respectively. Conclusion: Results of our study allow us to conclude that serum PSA concentration of higher than 20ng/mL was the most accurate cutting point than a serum concentration of PSA higher than 10ng/mL to predict metastasis in radionuclide bone scintigraphy. In this way, unnecessary cost can be avoided, since a considerable part of prostate adenocarcinomas present low serum PSA levels less than 20 ng/mL and for these cases radionuclide bone scintigraphy could be unnecessary.

Keywords: bone scan, cut off value, prostate specific antigen value, scintigraphy

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Authors: Mohamed Gar Alalm, Shinichi Ookawara, Ahmed Tawfik

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In the present work, photocatalytic oxidation of phenol by iron (Fe+2) doped titanium dioxide (TiO2) was studied. The source of irradiation was solar simulated light under measured UV flux. The effect of light intensity, pH, catalyst loading, and initial concentration of phenol were investigated. The maximum removal of phenol at optimum conditions was 78%. The optimum pH was 5.3. The most effective degradation occurred when the catalyst dosage was 600 mg/L. increasing the initial concentration of phenol decreased the degradation efficiency due to the deactivation of active sites by additional intermediates. Phenol photocatalytic degradation moderately fitted to the pseudo-first order kinetic equation approximated from Langmuir–Hinshelwood model.

Keywords: phenol, photocatalytic, solar, titanium dioxide

Procedia PDF Downloads 383

Authors: Mustapha Bouhoun Ali, Ahmed Yacine Badjah Hadj Ahmed, Mouloud Attou, Abdel Hamid Elias, Mohamed Amine Didi

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The extraction of uranium(VI) from aqueous solutions has been investigated using 1-hydroxyhexadecylidene-1,1-diphosphonic acid (HHDPA) and 1-hydroxydodecylidene-1,1-diphosphonic acid (HDDPA), which were synthesized and characterized by elemental analysis and by FT-IR, 1H NMR, 31P NMR spectroscopy. In this paper, we propose a tentative assignment for the shifts of those two ligands and their specific complexes with uranium(VI). We carried out the extraction of uranium(VI) by HHDPA and HDDPA from [carbon tetrachloride + 2-octanol (v/v: 90%/10%)] solutions. Various factors such as contact time, pH, organic/aqueous phase ratio and extractant concentration were considered. The optimum conditions obtained were: contact time = 20 min, organic/aqueous phase ratio = 1, pH value = 3.0 and extractant concentration = 0.3M. The extraction yields are more significant in the case of the HHDPA which is equipped with a hydrocarbon chain, longer than that of the HDDPA. Logarithmic plots of the uranium(VI) distribution ratio vs. pHeq and the extractant concentration showed that the ratio of extractant to extracted uranium(VI) (ligand/metal) is 2:1. The formula of the complex of uranium(VI) with the HHDPA and the DHDPA is UO2(H3L)2 (HHDPA and DHDPA are denoted as H4L). A spectroscopic analysis has showed that coordination of uranium(VI) takes place via oxygen atoms.

Keywords: liquid-liquid extraction, uranium(VI), 1-hydroxyalkylidene-1, 1-diphosphonic acids, HHDPA, HDDPA, aqueous solution

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Authors: H. Salonen, E. Castagnoli, C. Vornanen-Winqvist, R. Mikkola, C. Duchaine, L. Morawska, J. Kurnitski

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A wide range of health effects among occupants are associated with the exposure to bioaerosols from fungal sources. Although the accurate role of these aerosols in causing the symptoms and diseases is poorly understood, the important effect of bioaerosol exposure on human health is well recognized. Thus, there is a need to determine all of the contributing factors related to the concentration of fungi in indoor air. In this study, we reviewed and summarized the different factors affecting the concentrations of viable fungi in school buildings. The literature research was conducted using Pubmed and Google Scholar. In addition, we searched the lists of references of selected articles. According to the literature, the main factors influencing the concentration of viable fungi in the school buildings are moisture damage in building structures, the season (temperature and humidity conditions), the type and rate of ventilation, the number and activities of occupants and diurnal variations. This study offers valuable information that can be used in the interpretation of the fungal analysis and to decrease microbial exposure by reducing known sources and/or contributing factors. However, more studies of different local factors contributing to the human microbial exposure in school buildings—as well as other type of buildings and different indoor environments—are needed.

Keywords: fungi, concentration, indoor, school, contributing factor

Procedia PDF Downloads 242

Authors: Supat Chaiyakul, Direk Sukkasem, Patnachapa Natthapanpaisith

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Sinlek rice flour beverage or instant product is a dietary supplement for dysphagia, or difficulty swallowing. It is also consumed by individuals who need to consume supplements to maintain their calorific needs. This product provides protein, fat, iron, and a high concentration of carbohydrate from rice flour. However, the application of native flour is limited due to its high viscosity. Starch modification by controlling starch retrogradation was used in this study. The research studies the effects of rice flour concentration and retrogradation treatment on the physical properties of instant Sinlek brown rice. The native rice flour, gelatinized rice flour, and flour gels retrograded under 4 °C for 3 and 7 days were investigated. From the statistical results, significant differences between native and retrograded flour were observed. The concentration of rice flour was the main factor influencing the swelling power, solubility, and pasting properties. With the increase in rice flour content from 10 to 15%, swelling power, peak viscosity, trough, and final viscosity decreased; but, solubility, pasting temperature, peak time, breakdown, and setback increased. The peak time, pasting temperature, peak viscosity, trough, and final viscosity decreased as the storage period increased from 3 to 7 days. The retrograded rice flour powders had lower pasting temperature, peak viscosity, breakdown, and final viscosity than the gelatinized and native flour powders. Reduction of starch viscosity by gelatinization and controlling starch retrogradation could allow for increased quantities of rice flour in instant rice beverages. Also, the treatment could increase the energy and nutrient densities of rice beverages without affecting the viscosity of this product.

Keywords: instant rice, pasting properties, pregelatinization, retrogradation

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Authors: B. Afsari, M. Hassanpour, M. Shabani

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This study aimed to investigate the phase morphology of ternary blends comprising PP, PA6, and a blend of EPDM and EPDM-g-MA in a 70/15/15 ratio. Varying ratios of EPDM to EPDM-g-MA were examined. As the proportion of EPDM-g-MA increased, an interlayer phase formed between the dispersed PA6 domains and the PP matrix. This resulted in the development of a core-shell encapsulation morphology within the blends. The concentration of the EPDM-g-MA component is inversely correlated with the average size of PA6 particles. Additionally, blends containing higher proportions of the EPDM-g-MA rubbery phase exhibited an aggregated structure of the modifier particles. Notably, as the concentration of EPDM-g-MA increased from 0% to 15% in the blend, there was a consistent monotonic reduction in the size of PA6 particles.

Keywords: phase morphology, rubbery phase, rubber functionality, ternary blends

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Authors: Anna Romanova, Mojtaba Mahmoodian, Morteza A. Alani

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Concrete sewer pipes are known to suffer from a process of hydrogen sulfide gas induced sulfuric acid corrosion. This leads to premature pipe degradation, performance failure and collapses which in turn may lead to property and health damage. The above work reports on a field study undertaken in working sewer manholes where the parameters of effluent temperature and pH as well as ambient temperature and concentration of hydrogen sulfide were continuously measured over a period of two months. Early results suggest that effluent pH has no direct effect on hydrogen sulfide build up; on average the effluent temperature is 3.5°C greater than the ambient temperature inside the manhole and also it was observed that hydrogen sulfate concentration increases with increasing temperature.

Keywords: concrete corrosion, hydrogen sulfide gas, temperature, sewer pipe

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Authors: Amir Shafiee Kisomi, Mehrdad Mofidi

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Nowadays, fuel cells as a promising alternative for power source have been widely studied owing to their security, high energy density, low operation temperatures, renewable capability and low environmental pollutant emission. The nanoparticles of core-shell type could be widely described in a combination of a shell (outer layer material) and a core (inner material), and their characteristics are greatly conditional on dimensions and composition of the core and shell. In addition, the change in the constituting materials or the ratio of core to the shell can create their special noble characteristics. In this study, a fast technique for the fabrication of a Pd-Co/G/GCE modified electrode is offered. Thermal decomposition reaction of cobalt (II) formate salt over the surface of graphene/glassy carbon electrode (G/GCE) is utilized for the synthesis of Co nanoparticles. The nanoparticles of Pd-Co decorated on the graphene are created based on the following method: (1) Thermal decomposition reaction of cobalt (II) formate salt and (2) the galvanic replacement process Co by Pd2+. The physical and electrochemical performances of the as-prepared Pd-Co/G electrocatalyst are studied by Field Emission Scanning Electron Microscopy (FESEM), Energy Dispersive X-ray Spectroscopy (EDS), Cyclic Voltammetry (CV), and Chronoamperometry (CHA). Galvanic replacement method is utilized as a facile and spontaneous approach for growth of Pd nanostructures. The Pd-Co/G is used as an anode catalyst for ethanol oxidation in alkaline media. The Pd-Co/G not only delivered much higher current density (262.3 mAcm-2) compared to the Pd/C (32.1 mAcm-2) catalyst, but also demonstrated a negative shift of the onset oxidation potential (-0.480 vs -0.460 mV) in the forward sweep. Moreover, the novel Pd-Co/G electrocatalyst represents large electrochemically active surface area (ECSA), lower apparent activation energy (Ea), higher levels of durability and poisoning tolerance compared to the Pd/C catalyst. The paper demonstrates that the catalytic activity and stability of Pd-Co/G electrocatalyst are higher than those of the Pd/C electrocatalyst toward ethanol oxidation in alkaline media.

Keywords: thermal decomposition, nanostructures, galvanic replacement, electrocatalyst, ethanol oxidation, alkaline media

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Authors: Layan Moussa, Darine Salam, Samir Mustapha

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Heavy metal contamination in agricultural soils in Lebanon poses serious environmental and health problems. Intensive efforts are employed to improve existing quantification methods of heavy metals in contaminated environments since conventional detection techniques have shown to be time-consuming, tedious, and costly. The implication of hyperspectral remote sensing in this field is possible and promising. However, factors impacting the efficiency of hyperspectral imaging in detecting and quantifying heavy metals in agricultural soils were not thoroughly studied. This study proposes to assess the use of hyperspectral imaging for the detection of Ni in agricultural clay soil collected from the Bekaa Valley, a major agricultural area in Lebanon, under different contamination levels and soil moisture content. Soil samples were contaminated with Ni, with concentrations ranging from 150 mg/kg to 4000 mg/kg. On the other hand, soil with background contamination was subjected to increased moisture levels varying from 5 to 75%. Hyperspectral imaging was used to detect and quantify Ni contamination in the soil at different contamination levels and moisture content. IBM SPSS statistical software was used to develop models that predict the concentration of Ni and moisture content in agricultural soil. The models were constructed using linear regression algorithms. The spectral curves obtained reflected an inverse correlation between both Ni concentration and moisture content with respect to reflectance. On the other hand, the models developed resulted in high values of predicted R2 of 0.763 for Ni concentration and 0.854 for moisture content. Those predictions stated that Ni presence was well expressed near 2200 nm and that of moisture was at 1900 nm. The results from this study would allow us to define the potential of using the hyperspectral imaging (HSI) technique as a reliable and cost-effective alternative for heavy metal pollution detection in contaminated soils and soil moisture prediction.

Keywords: heavy metals, hyperspectral imaging, moisture content, soil contamination

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Authors: Faycal Benyahia, Abdelmohsen Albedah, Bel Abbes Bachir Bouiadjra

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In this paper, the finite element analysis is applied to study the performance of the bonded composite reinforcement or repair for reducing stress concentration at a semi-circular lateral notch and repairing cracks emanating from this kind of notch. The effects of the adhesive properties on the variation of the stress intensity factor at the crack tip were highlighted. The obtained results show that the stress concentration factor at the notch tip is reduced about 30% and the maximal reduction of the stress intensity factor is about 80%. The adhesive properties must be optimized in order to increase the performance of the patch repair or reinforcement.

Keywords: bonded repair, notch, crack, adhesive, composite

Procedia PDF Downloads 375

Authors: J. I. Santos, A. E. Cesarin, C. A. R. Sales, M. B. B. Triano, P. F. R. B. Martins, A. F. Braga, N. J. Neto, A., A. M. Barroso, P. L. C. A. Alves, C. A. M. Huaman

Abstract:

Climate change projections based on the emission of greenhouse effect gases suggest an increase in the concentration of atmospheric carbon dioxide, in up to 750 ppm. In this scenario, we have significant changes in plant development, and consequently, in agricultural systems. This study aims to evaluate the interaction between culture (Glycine max) and weed (Amaranthus viridis and Euphorbia heterophylla) in two conditions of CO₂, 400 and 800 ppm. The results showed that the coexistence of culture with both weed species resulted in a mutual loss, with decrease in dry mass productivity of culture + weeds, in both conditions of CO₂. However, when the culture is grown in association with E. heterophylla, total dry mass of culture + weed was smaller at 800 ppm. Soybean was more aggressive in comparison to the A. viridis in both the concentrations of CO₂, but not in relation to the E. heterophylla.

Keywords: plants interaction, increase of [CO₂], plants of metabolismo C3, glycine max

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Authors: Girmaye Abebe, Brook Lemma

Abstract:

Adsorption of phosphorus (P as PO43-) in filter cake was studied to assess the media's capability in removing phosphorous from wastewaters. The composition of the filter cake that was generated from alum manufacturing process as waste residue has high amount of silicate from the complete silicate analysis of the experiment. Series of batches adsorption experiments were carried out to evaluate parameters that influence the adsorption capacity of PO43-. The factors studied include the effect of contact time, adsorbent dose, thermal pretreatment of the adsorbent, neutralization of the adsorbent, initial PO43- concentration, pH of the solution and effect of co-existing anions. Results showed that adsorption of PO43- is fairly rapid in first 5 min and after that it increases slowly to reach the equilibrium in about 1 h. The treatment efficiency of PO43- was increased with adsorbent extent. About 90% removal efficiency was increased within 1 h at an optimum adsorbent dose of 10 g/L for initial PO43- concentration of 10 mg/L. The amount of PO43- adsorbed increased with increasing initial PO43- concentration. Heat treatment and surface neutralization of the adsorbent did not improve the PO43- removal capacity and efficiency. The percentage of PO43- removal remains nearly constant within the pH range of 3-8. The adsorption data at ambient pH were well fitted to the Langmuir Isotherm and Dubinin–Radushkevick (D–R) isotherm model with a capacity of 25.84 and 157.55 mg/g of the adsorbent respectively. The adsorption kinetic was found to follow a pseudo-second-order rate equation with an average rate constant of 3.76 g.min−1.mg−1. The presence of bicarbonate or carbonate at higher concentrations (10–1000 mg/L) decreased the PO43- removal efficiency slightly while other anions (Cl-, SO42-, and NO3-) have no significant effect within the concentration range tested. The overall result shows that the filter cake is an efficient PO43- removing adsorbent against many parameters.

Keywords: wastewater, filter cake, adsorption capacity, phosphate (PO43-)

Procedia PDF Downloads 216

Authors: Stella Sten, Peter Hedström, Joakim Odqvist, Susanne Norgren

Abstract:

Two functionally graded cemented carbide samples have been produced by local addition of Titanium carbide (TiC) to a pressed Tungsten carbide and Cobalt, WC-10 wt% Co, green body prior to sintering, with the aim of creating a gradient in both composition and grain size in the as-sintered component. The two samples differ only by the in-going WC particle size, where one sub-micron and one coarse WC particle size have been chosen for comparison. The produced sintered samples had a gradient, thus a non-homogenous structure. The Titanium (Ti), Cobalt (Co), and Carbon (C) concentration profiles have been investigated using SEM-EDS and WDS; in addition, the Vickers hardness profile has been measured. Moreover, the Ti concentration profile has been simulated using DICTRA software and compared with experimental results. The concentration and hardness profiles show a similar trend for both samples. Ti and C levels decrease, as expected from the area of TiC application, whereas Co increases towards the edge of the samples. The non-homogenous composition affects the number of stable phases and WC grain size evolution. The sample with finer in-going WC grain size shows a shorter gamma (γ) phase zone and a larger difference in WC grain size compared to the coarse-grained sample. Both samples show, independent of the composition, the presence of abnormally large grains.

Keywords: cemented carbide, functional gradient material, grain growth, sintering

Procedia PDF Downloads 76

Authors: R. O. Anyasi, H. I. Atagana

Abstract:

In this study, phytoextraction ability of a weed on Aroclor 1254 was studied under greenhouse conditions. Chromolaena odorata plants were transplanted into soil containing 100, 200, and 500 ppm of Aroclor in 1L pots. The experiments were watered daily at 70 % moisture field capacity. Parameters such as fully expanded leaves per plant, shoot length, leaf chlorophyll content as well as root length at harvest were measured. PCB was not phytotoxic to C. odorata growth but plants in the 500 ppm treatment only showed diminished growth at the sixth week. Percentage increases in height of plant were 45.9, 39.4 and 40.0 for 100, 200 and 500 ppm treatments respectively. Such decreases were observed in the leaf numbers, root length and leaf chlorophyll concentration. The control sample showed 48.3 % increase in plant height which was not significant from the treated samples, an indication that C. odorata could survive such PCB concentration and could be used to remediate contaminated soil. Mean total PCB absorbed by C. odorata plant was between 6.40 and 64.60 ppm per kilogram of soil, leading to percentage PCB absorption of 0.03 and 17.03 % per kilogram of contaminated soil. PCBs were found mostly in the root tissues of the plants, and the Bioaccumulation factor were between 0.006-0.38. Total PCB absorbed by the plant increases as the concentration of the compound is increased. With these high BAF ensured, C. odorata could serve as a promising candidate plant in phytoextraction of PCB from a PCB-contaminated soil.

Keywords: phytoremediation, bioremediation, soil restoration, polychlorinated biphenyls (PCB), biological treatment, aroclor

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Authors: Anurakti Shukla, Sudhakar Srivastava

Abstract:

Cyanobacteria are known for rapid growth rates, high biomass, and the ability to accumulate potentially toxic elements and contaminants. The present work was planned to develop a low-cost, feasible prototype, CyanoClean, for the growth of a cyanobacterial consortium for the removal of arsenic (As) from water. The cyanobacterial consortium consisting of Oscillatoria, Phormidiumand Gloeotrichiawas used, and the conditions for optimal growth of the consortium were standardized. A pH of 7.6, initial cyanobacterial biomass of 10 g/L, and arsenite [As(III)] and arsenate [As(V)] concentration of 400 μΜand 600 μM, respectively, were found to be suitable. The CyanoClean prototype was designed with acrylic sheet and had arrangements for optimal cyanobacterial growth in natural sunlight and also in artificial light. The As removal experiments in concentration- and duration-dependent manner demonstrated removal of up to 39-69% and 9-33% As respectively from As(III) and As(V)-contaminated water. In field testing of CyanoClean, natural As-contaminated groundwater was used, and As reduction was monitored when a flow rate of 3 L/h was maintained. In a field experiment, As concentration in groundwater was found to reduce from 102.43 μg L⁻¹ to <10 μg L⁻¹ after 6 h in natural sunlight. However, in shaded conditions under artificial light, the same result was achieved after 9 h. The CyanoClean prototype is of simple design and can be easily up-scaled for application at a small- to medium-size land and shall be affordable even for a low- to middle-income group farmer.

Keywords: cyanoclean, gloeotrichia, oscillatoria, phormidium, phycoremediation

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Authors: Rachmat Mauludin, Novita R. Kusuma, Diky Mudhakir

Abstract:

Famotidine (FMT) is one of used substances in the treatment of hiperacidity and peptic ulcer, administered orally and parenterally via intravenous injection. Oral administration, which is more favorable, has been reported to have many obstacles in the process of the treatment, includes decreasing the bioavailability of FMT. This research was aimed to prepare FMT in form of solid lipid nanoparticles (SLN) with size ranging between 100-200 nm. The research was carried out also by optimizing factors that may affect physical stability of SLN. Formulation of Famotidine SLN was carried out by optimizing factors, such as duration of homogenization and sonication, lipid concentration, stabilizer composition and stabilizer concentration. SLN physical stability was evaluated (particle size distribution) for 42 days in 3 diferent temperatures. Entrapment efficiency and drug loading was determined indirectly and directly. The morphology of SLN was visualized by transmission electron microscope (TEM). In vitro release study of FMT was conducted in 2 mediums, at pH of 1.2 and 7.4. Chemical stability of FMT was determined by quantifying the concentration of FMT within 42 days. Famotidin SLN consisted of GMS as lipid and poloxamer 188, lecithin, and polysorbate 80 as stabilizers. Homogenization and sonication was performed for 5 minutes and 10 minutes. Physyical stability of nanoparticles at 3 different temperatures was no significant difference. The best formula was physically stable until 42 days with mean particle size below 200 nm. Nanoparticles produced was able to entrap FMT until 86.6%. Evaluation by TEM showed that nanoparticles was spherical and solid. In medium pH of 1.2, FMT was released only 30% during 4 hour. On the other hand, within 4 hours SLN could release FMT completely in medium pH of 7.4. The FMT concentration in nanoparticles dispersion was maintained until 95% in 42 days (40oC, RH 75%). Famotidine SLN was able to be produced with mean particle size ranging between 100-200 nm and physically stable for 42 days. SLN could be loaded by 86,6% of FMT. Morphologically, obtained SLN was spheric and solid. During 4 hours in medium pH of 1.2 and 7.4, FMT was released until 30% and 100%, respectively.

Keywords: solid lipid nanoparticle (SLN), famotidine (FMT), physicochemical properties, release study

Procedia PDF Downloads 340

Authors: Helder Shelton Abel Manguene, Giovanna Buonocore, Herminio Francisco Muiambo

Abstract:

Paved roads are designed for 10-15 years of life. However, many asphalted roads suffer degradation before reaching their lifetime due to aging caused by load conditions and climatic factors. Oxidation is the main asphalt aging mechanism, which leads to a reduced bond between aggregate particles, increasing the potential for stripping and moisture damage, decreasing fatigue lifetime and reducing resistance to thermal cracking. To improve the performance of asphalt and mitigate these problems, modifiers such as polymers, oils and certain residues have been used. This work aims to study the influence of the addition of high-density polyethylene (HDPE) and engine oil on the thermal stability of asphalt in an oxidizing atmosphere. For the study, compositions containing asphalt, motor oil and HDPE were prepared, varying the concentration of the motor oil by 2.5%, 5%, 7.5% and 10% and keeping the HDPE concentration fixed at 5%. The results show that the pure asphalt sample is degraded in a single step that starts at approximately 311 ºC; All samples of modified asphalt except the one that contains 5% of motor oil have three degradation steps that start below the starting temperature of degradation of pure asphalt (about 250-300 ºC); The temperature of onset of degradation of the modified asphalt is shown to decrease as the concentration of the motor oil increases, suggesting a slight loss of thermal stability of the asphalt as the quantity of the motor oil increases.

Keywords: Asphalt, DTG, engine oil, HDPE, TGA

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Authors: Antoifi Abdoulhalik, Ashraf Ahmed

Abstract:

Saltwater intrusion (SWI) in coastal aquifers has become a growing threat for many countries around the world. While various control measures have been suggested to mitigate SWI, the construction of subsurface physical barriers remains one of the most effective solutions for this problem. In this work, we used laboratory experiments and numerical simulations to investigate the effectiveness of subsurface dams in heterogeneous layered coastal aquifer with different layering patterns. Four different cases were investigated, including a homogeneous (case H), and three heterogeneous cases in which a low permeability (K) layer was set in the top part of the system (case LH), in the middle part of the system (case HLH) and the bottom part of the system (case HL). Automated image analysis technique was implemented to quantify the main SWI parameters under high spatial and temporal resolution. The method also provides transient salt concentration maps, allowing for the first time clear visualization of the spillage of saline water over the dam (advancing wedge condition) as well as the flushing of residual saline water from the freshwater area (receding wedge condition). The SEAWAT code was adopted for the numerical simulations. The results show that the presence of an overlying layer of low permeability enhanced the ability of the dam to retain the saline water. In such conditions, the rate of saline water spillage and inland extension may considerably be reduced. Conversely, the presence of an underlying low K layer led to a faster increase of saltwater volume on the seaward side of the wall, therefore considerably facilitating the spillage. The results showed that a complete removal of the residual saline water eventually occurred in all the investigated scenarios, with a rate of removal strongly affected by the hydraulic conductivity of the lower part of the aquifer. The data showed that the addition of the underlying low K layer in case HL caused the complete flushing to be almost twice longer than in the homogeneous scenario.

Keywords: heterogeneous coastal aquifers, laboratory experiments, physical barriers, seawater intrusion control

Procedia PDF Downloads 233