Search results for: non-point source pollutants

Authors: Kakha Nadiardze, Nana Phirosmanashvili

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The goal of this paper is to present the problems of lack of information among farmers in food safety. Global food supply chains are becoming more and more diverse, making traceability systems much harder to implement across different food markets. In this abstract, we will present our work for analyzing the key developments in Georgian food market from regulatory controls to administrative procedures to traceability technologies. Food safety and quality assurance are most problematic issues in Georgia as food trade networks become more and more complex, food businesses are under more and more pressure to ensure that their products are safe and authentic. The theme follow-up principles from farm to table must be top-of-mind for all food manufacturers, farmers and retailers. Following the E. coli breakout last year, as well as more recent cases of food mislabeling, developments in food traceability systems is essential to food businesses if they are to present a credible brand image. Alongside this are the ever-developing technologies in food traceability networks, technologies that manufacturers and retailers need to be aware of if they are to keep up with food safety regulations and avoid recall. How to examine best practice in food management is the main question in order to protect company brand through safe and authenticated food. We are working with our farmers to work with our food safety experts and technology developers throughout the food supply chain. We provide time by time food analyses on heavy metals, pesticide residues and different pollutants. We are disseminating information among farmers how the latest food safety regulations will impact the methods to use to identify risks within their products.

Keywords: food safety, GMO, LMO, E. coli, quality

Procedia PDF Downloads 507

Authors: M. Umar Dahot, G. S. Mangrio

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In this study Agro-industrial waste was used as a carbon source, which is a low cost substrate. Along with this, various sugars and molasses of 2.5% and 5% were investigated as substrate/carbon source for the growth of A.niger and Pectinase production. Different nitrogen sources were also used. An overview of results obtained show that 5% sucrose, 5% molasses and 0.4% (NH4)2SO4 were found the best carbon and nitrogen sources for the production of pectinase by A. niger. The maximum production of pectinase (26.87units/ml) was observed at pH 6.0 after 72 hrs incubation. The optimum temperature for the maximum production of pectinase was achieved at 35ºC when maximum production of pectinase was obtained as 28.25Units/ml.Pectinase enzyme was purified with ammonium sulphate precipitation and dialyzed sample was finally applied on gel filtration chromatography (Sephadex G-100) and Ion Exchange DEAE A-50. The enzyme was purified 2.5 fold by gel chromatography on Sephadex G-100 and Four fractions were obtained, Fraction 1, 2, 4 showed single band while Fraction -3 showed multiple bands on SDS Page electrophoresis. Fraction -3 was pooled, dialyzed and separated on Sephdex A-50 and two fractions 3a and 3b showed single band. The molecular weights of the purified fractions were detected in the range of 33000 ± 2000 and 38000± 2000 Daltons. The purified enzyme was specifically most active with pure pectin, while pectin, Lemon pectin and orange peel given lower activity as compared to (control). The optimum pH and temperature for pectinase activity was found between pH 5.0 and 6.0 and 40°- 50°C, respectively. The enzyme was stable over the pH range 3.0-8.0. The thermostability of was determined and it was observed that the pectinase activity is heat stable and retains activity more than 40% when incubated at 90°C for 10 minutes. The pectinase activity of F3a and F3b was increased with different metal ions. The Pectinase activity was stimulated in the presence of CaCl2 up to 10-30%. ZnSO4, MnSO4 and Mg SO4 showed higher activity in fractions F3a and F3b, which indicates that the pectinase belongs to metalo-enzymes. It is concluded that A. niger is capable to produce pH stable and thermostable pectinase, which can be used for industrial purposes.

Keywords: pectinase, a. niger, production, purification, characterization

Procedia PDF Downloads 409

Authors: T. Abdelkrim, K. Ben Seddik, B. Bezza, K. Benamrane, Aeh. Benkhelifa

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This paper proposes an implementation of boost converter for a resistive load using photovoltaic energy as a source. The model of photovoltaic cell and operating principle of boost converter are presented. A PIC micro controller is used in the close loop control to generate pulses for controlling the converter circuit. To performance evaluation of boost converter, a variation of output voltage of PV panel is done by shading one and two cells.

Keywords: boost converter, microcontroller, photovoltaic power generation, shading cells

Procedia PDF Downloads 870

Authors: Misha Ali, Qayyum Husain, Nida Alam, Masood Ahmad

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Improving the activity and stability of the enzyme is an important aspect in bioremediation processes. Immobilization of enzyme is an efficient approach to amend the properties of biocatalyst required during wastewater treatment. The present study was done to immobilize partially purified ginger peroxidase on amino functionalized silica coated titanium dioxide nanocomposite. Interestingly there was an enhancement in enzyme activity after immobilization on nanosupport which was evident from effectiveness factor (η) value of 1.76. Immobilized enzyme was characterized by transmission electron microscopy, scanning electron microscopy and Fourier transform infrared spectroscopy. Immobilized peroxidase exhibited higher activity in a broad range of pH and temperature as compared to free enzyme. Also, the thermostability of peroxidase was strikingly improved upon immobilization. After six repeated uses, the immobilized peroxidase retained around 62% of its dye decolorization activity. There was a 4 fold increase in Vmax of immobilized peroxidase as compared to free enzyme. Circular dichroism spectroscopy demonstrated conformational changes in the secondary structure of enzyme, a possible reason for the enhanced enzyme activity after immobilization. Immobilized peroxidase was highly efficient in the removal of acid yellow 42 dye in a stirred batch process. Our study shows that this bio-remediating system has remarkable potential for treatment of aromatic pollutants present in wastewater.

Keywords: acid yellow 42, decolorization, ginger peroxidase, immobilization

Procedia PDF Downloads 243

Authors: Benjamin Thomas Greer, Grace Cotulla, Mandy Johnson

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Human trafficking is one of the fastest growing international crimes and human rights violations in the world. The United States Department of State (State Department) approximates some 800,000 to 900,000 people are annually trafficked across sovereign borders, with approximately 14,000 to 17,500 of these people coming into the United States. Today’s slavery is conducted by unscrupulous individuals who are often connected to organized criminal enterprises and transnational gangs, extracting huge monetary sums. According to the International Labour Organization (ILO), human traffickers collect approximately $32 billion worldwide annually. Surpassed only by narcotics dealing, trafficking of humans is tied with illegal arms sales as the second largest criminal industry in the world and is the fastest growing field in the 21st century. Perpetrators of this heinous crime abound. They are not limited to single or “sole practitioners” of human trafficking, but rather, often include Transnational Criminal Organizations (TCO), domestic street gangs, labor contractors, and otherwise seemingly ordinary citizens. Monetary gain is being elevated over territorial disputes and street gangs are increasingly operating in a collaborative effort with TCOs to further disguise their criminal activity; to utilizing their vast networks, in an attempt to avoid detection. Traffickers rely on a network of clandestine routes to sell their commodities with impunity. As law enforcement agencies seek to retard the expansion of transnational criminal organization’s entry into human trafficking, it is imperative that they develop reliable trafficking mapping of known exploitative routes. In a recent report given to the Mexican Congress, The Procuraduría General de la República (PGR) disclosed, from 2008 to 2010 they had identified at least 47 unique criminal networking routes used to traffic victims and that Mexico’s estimated domestic victims number between 800,000 adults and 20,000 children annually. Designing a reliable mapping system is a crucial step to effective law enforcement response and deploying a successful victim support system. Creating this mapping analytic is exceedingly difficult. Traffickers are constantly changing the way they traffic and exploit their victims. They swiftly adapt to local environmental factors and react remarkably well to market demands, exploiting limitations in the prevailing laws. This article will highlight how human trafficking has become one of the fastest growing and most high profile human rights violations in the world today; compile current efforts to map and illustrate trafficking routes; and will demonstrate how the proprietary analytical mapping analysis of point-source and destination-source mapping can help local law enforcement, governmental agencies and victim services providers effectively respond to the type and nature of trafficking to their specific geographical locale. Trafficking transcends state and international borders. It demands an effective and consistent cooperation between local, state, and federal authorities. Each region of the world has different impact factors which create distinct challenges for law enforcement and victim services. Our mapping system lays the groundwork for a targeted anti-trafficking response.

Keywords: human trafficking, mapping, routes, law enforcement intelligence

Procedia PDF Downloads 377

Authors: Gianvito Colucci, Valeria Di Cosmo, Matteo Nicoli, Orsola Maria Robasto, Laura Savoldi

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The hydrogen value chain deployment is likely to be boosted in the near term by the energy security measures planned by European countries to face the recent energy crisis. In this context, some countries are recognized to have a crucial role in the geopolitics of hydrogen as importers, consumers and exporters. According to the European Hydrogen Backbone Initiative, Italy would be part of one of the 5 corridors that will shape the European hydrogen market. However, the set targets are very ambitious and require large investments to rapidly develop effective hydrogen policies: in this regard, scenario analysis is becoming increasingly important to support energy planning, and energy system optimization models appear to be suitable tools to quantitively carry on that kind of analysis. The work aims to assess the competitiveness of hydrogen in contributing to the Italian energy security in the coming years, under different price and import conditions, using the energy system model TEMOA-Italy. A wide spectrum of hydrogen technologies is included in the analysis, covering the production, storage, delivery, and end-uses stages. National production from fossil fuels with and without CCS, as well as electrolysis and import of low-carbon hydrogen from North Africa, are the supply solutions that would compete with other ones, such as natural gas, biomethane and electricity value chains, to satisfy sectoral energy needs (transport, industry, buildings, agriculture). Scenario analysis is then used to study the competition under different price and import conditions. The use of TEMOA-Italy allows the work to catch the interaction between the economy and technological detail, which is much needed in the energy policies assessment, while the transparency of the analysis and of the results is ensured by the full accessibility of the TEMOA open-source modeling framework.

Keywords: energy security, energy system optimization models, hydrogen, natural gas, open-source modeling, scenario analysis, TEMOA

Procedia PDF Downloads 109

Authors: Orish E. Orisakwe, Chinna N. Orish, Anthonet N. Ezejiofor

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African mesquite has been recognized for its antimicrobial, anti-inflammatory, and potential anticarcinogenic activities. However, its neuroprotective benefits against heavy metal-induced neurotoxicity remain largely unexplored. Therefore, the objective of this study was to investigate the neuroprotective properties of African mesquite in the hippocampus and olfactory bulb against common environmental pollutants, including Cd, As, Hg, and Pb. Thirty-five albino Sprague Dawley rats were divided into five groups for the experiment. Group 1 served as the control and did not receive either the heavy metal mixture (HMM) or African mesquite. Group 2 was orally administered HMM, consisting of PbCl2 (20 mg/kg), CdCl2 (1.61 mg/kg), HgCl2 (0.40 mg/kg), and NaAsO3 (10 mg/kg), for 960 days. Meanwhile, groups 3, 4, and 5 were treated with HMM along with African mesquite at doses of 500 mg/kg, 1000 mg/kg, and 1500 mg/kg, respectively. African mesquite reduced heavy metal accumulation in the hippocampus and olfactory bulb. Additionally, Sprague Dawley rats exhibited improved performance in the Passive avoidance and Cincinnati Maze tests. Furthermore, treatment with African mesquite significantly alleviated inflammation macromolecules peroxidation. It also restored the concentrations of SOD, CAT, GSH, GPx, Hmox-1, and reduced the activity of AChE, NRF2 and NFkB and improved histopathological findings. African mesquite exhibits a multifaceted neuroprotective effect with the potential to mitigate various aspects of heavy metal-induced neurotoxicity.

Keywords: African mesquite, heavy metal mixture;, neurotoxicity;, chemoprevention

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Authors: Henry O. Udeha, Kwaku G. Duodub, Afam I. O. Jideanic

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Finger millet (FM) [Eleusine coracana] is considered as a potential ‘‘super grain’’ by the United States National Academies as one of the most nutritious among all the major cereals. The regular consumption of FM-based diets has been associated with reduced risk of diabetes, cataract and gastrointestinal tract disorder. Hyperglycaemic, hypocholesterolaemic and anticataractogenic, and other health improvement properties have been reported. This study examined the effect of fermentation time and microbial source on physicochemical properties, phenolic compounds and antioxidant activity of two finger millet (FM) malt flours. Sorghum was used as an external reference. The grains were malted, mashed and fermented using the grain microflora and Lactobacillus fermentum. The phenolic compounds of the resulting beverage were identified and quantified using ultra-performance liquid chromatography (UPLC) and mass spectrometer system (MS). A fermentation-time dependent decrease in pH and viscosities of the beverages, with a corresponding increase in sugar content were noted. The phenolic compounds found in the FM beverages were protocatechuic acid, catechin and epicatechin. Decrease in total phenolics of the beverages was observed with increased fermentation time. The beverages exhibited 2, 2-diphenyl-1-picrylhydrazyl, 2, 2՛-azinobis-3-ethylbenzthiazoline-6-sulfonic acid radical scavenging action and iron reducing activities, which were significantly (p < 0.05) reduced at 96 h fermentation for both microbial sources. The 24 h fermented beverages retained a higher amount of total phenolics and had higher antioxidant activity compared to other fermentation periods. The study demonstrates that FM could be utilised as a functional grain in the production of non-alcoholic beverage with important phenolic compounds for health promotion and wellness.

Keywords: antioxidant activity, eleusine coracana, fermentation, phenolic compounds

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Authors: Muhammed Rabiu, Moses S. Oluyomi, Joshua Olorundare

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Quarry activities are important to modern day life and the socio-economic development of local communities. Unfortunately, this industry is usually associated with air pollution. To assess the impact of quarry dust on plant biodiversity and agriculture, PM2.5, PM10 and some meteorological parameters were measured using Gas analyzer, handheld thermometer and Multifunction Anemometer (PCE-EM 888) as well as taking a social survey. High amount of particulate matters that exceeded the international standard were recorded at the study locations which include the Julius Berger Quarry and 1km away from the quarry site which serve as the base for the farmlands. The correlation coefficient between the particulate matters with the meteorological parameters of the locations all show a strong relationship with temperature recording a stronger value of 0.952 and 0.931 for PM2.5 and PM10 respectively. Similarly, the coefficient of determination 0.906 and 0.866 shows that temperature has the highest meteorological percentage variation on PM2.5 and PM10. Furthermore, a notable negative impact of quarrying on plant biodiversity and local farm crops are also revealed based on respondents’ results where wide range of local plants were affected with Maize and Azadiracta indica (Neem) been the most with respondent of 31.5% and 27.5%. According to the obtained results, it is highly recommended to develop green belt surrounding the quarrying using pollutant-tolerant trees (usually with broad leaves) in order to restrict spreading of quarrying dust via intercepting, filtering and absorbing pollutants.

Keywords: agriculture, air pollution, biodiversity, quarry

Procedia PDF Downloads 80

Authors: Staniek Halina

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The inappropriate trace elements supply such as iron(III) and chromium(III) may be risk factors of many metabolic disorders (e.g., anemia, diabetes, as well cause toxic effect). However, little is known about their mutual interactions and their impact on these disturbances. The effects of Cr(III) supplementation with a deficit or excess supply of Fe(III) in vivo conditions are not known yet. The objective of the study was to investigate the combined effect of different Fe(III) levels in the diet and simultaneous Cr(III) supplementation on the Ca distribution in organs in healthy rats. The assessment was based on a two-factor (2x3) experiment carried out on 54 female Wistar rats (Rattus norvegicus). The animals were randomly divided into 9 groups and for 6 weeks, they were fed semi-purified diets AIN-93 with three different Fe(III) levels in the diet as a factor A [control (C) 45 mg/kg (100% Recommended Daily Allowance for rodents), deficient (D) 5 mg/kg (10% RDA), and oversupply (H) 180 mg/kg (400% RDA)]. The second factor (B) was the simultaneous dietary supplementation with Cr(III) at doses of 1, 50 and 500 mg/kg of the diet. Iron(III) citrate was the source of Fe(III). The complex of Cr(III) with propionic acid, also called Cr₃ or chromium(III) propionate (CrProp), was used as a source of Cr(III) in the diet. The Ca content of analysed samples (liver, kidneys, spleen, heart, and femur) was determined with the Atomic Absorption Spectrometry (AAS) method. It was found that different dietary Fe(III) supply as well as Cr(III) supplementation independently and in combination influenced Ca metabolism in healthy rats. Regardless of the supplementation of Cr(III), the oversupply of Fe(III) (180 mg/kg) decreased the Ca content in the liver and kidneys, while it increased the Ca saturation of bone tissue. High Cr(III) doses lowered the hepatic Ca content. Moreover, it tended to decrease the Ca content in the kidneys and heart, but this effect was not statistically significant. The combined effect of the experimental factors on the Ca content in the liver and the femur was observed. With the increase in the Fe(III) content in the diet, there was a decrease in the Ca level in the liver and an increase in bone saturation, and the additional Cr(III) supplementation intensified those effects. The study proved that the different Fe(III) content in the diet, independently and in combination with Cr(III) supplementation, affected the Ca distribution in organisms of healthy rats.

Keywords: calcium, chromium(III), iron(III), rats, supplementation

Procedia PDF Downloads 194

Authors: Çiğdem Sezer, Aksem Aksoy, Leyla Vatansever

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This study has been done for the purpose of evaluation of public health and identifying of enterotoxigenic Staphyloccocus aureus in kitchen of catering. In the kitchen of catering, samples have been taken by swabs from surface of equipments which are in the salad section, meat section and bakery section. Samples have been investigated with classical cultural methods in terms of Staphyloccocus aureus. Therefore, as a 10x10 cm area was identified (salad, cutting and chopping surfaces, knives, meat grinder, meat chopping surface) samples have been taken with sterile swabs with helping FTS from this area. In total, 50 samples were obtained. In aseptic conditions, Baird-Parker agar (with egg yolk tellurite) surface was seeded with swabs. After 24-48 hours of incubation at 37°C, the black colonies with 1-1.5 mm diameter and which are surrounded by a zone indicating lecithinase activity were identified as S. aureus after applying Gram staining, catalase, coagulase, glucose and mannitol fermentation and termonuclease tests. Genotypic characterization (Staphylococcus genus and S.aureus species spesific) of isolates was performed by PCR. The ELISA test was applied to the isolates for the identification of staphylococcal enterotoxins (SET) A, B, C, D, E in bacterial cultures. Measurements were taken at 450 nm in an ELISA reader using an Ridascreen-Total set ELISA test kit (r-biopharm R4105-Enterotoxin A, B, C, D, E). The results were calculated according to the manufacturer’s instructions. A total of 50 samples of 97 S. aureus was isolated. This number has been identified as 60 with PCR analysis. According to ELISA test, only 1 of 60 isolates were found to be enterotoxigenic. Enterotoxigenic strains were identified from the surface of salad chopping and cutting. In the kitchen of catering, S. aureus identification indicates a significant source of contamination. Especially, in raw consumed salad preparation phase of contamination is very important. This food can be a potential source of food-borne poisoning their terms, and they pose a significant risk to consumers have been identified.

Keywords: Staphylococcus aureus, enterotoxin, catering, kitchen, health

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Authors: Ayesha Anjum, Arbaz Basha

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Active Galactic Nuclei (AGN) are the actively accreting centers of the galaxies that host supermassive black holes. AGN emits radiation in all wavelengths and also shows variability across all the wavelength bands. The analysis of flux variability tells us about the morphology of the site of emission radiation. Some of the major classifications of AGN are (a) Blazars, with featureless spectra. They are subclassified as BLLacertae objects, Flat Spectrum Radio Quasars (FSRQs), and others; (b) Seyferts with prominent emission line features are classified into Broad Line, Narrow Line Seyferts of Type 1 and Type 2 (c) quasars, and other types. Sloan Digital Sky Survey (SDSS) is an optical telescope based in Mexico that has observed and classified billions of objects based on automated photometric and spectroscopic methods. A sample of blazars is obtained from the third Fermi catalog. For variability analysis, we searched for light curves for these objects in Wide-Field Infrared Survey Explorer (WISE) and Near Earth Orbit WISE (NEOWISE) in two bands: W1 (3.4 microns) and W2 (4.6 microns), reducing the final sample to 256 objects. These objects are also classified into 155 BLLacs, 99 FSRQs, and 2 Narrow Line Seyferts, namely, PMNJ0948+0022 and PKS1502+036. Mid-infrared variability studies of these objects would be a contribution to the literature. With this as motivation, the present work is focused on studying a final sample of 256 objects in general and the Seyferts in particular. Owing to the fact that the classification is automated, SDSS has miclassified these objects into quasars, galaxies, and stars. Reasons for the misclassification are explained in this work. The variability analysis of these objects is done using the method of flux amplitude variability and excess variance. The sample consists of observations in both W1 and W2 bands. PMN J0948+0022 is observed between MJD from 57154.79 to 58810.57. PKS 1502+036 is observed between MJD from 57232.42 to 58517.11, which amounts to a period of over six years. The data is divided into different epochs spanning not more than 1.2 days. In all the epochs, the sources are found to be variable in both W1 and W2 bands. This confirms that the object is variable in mid-infrared wavebands in both long and short timescales. Also, the sources are observed for color variability. Objects either show a bluer when brighter trend (BWB) or a redder when brighter trend (RWB). The possible claim for the object to be BWB (present objects) is that the longer wavelength radiation emitted by the source can be suppressed by the high-energy radiation from the central source. Another result is that the smallest radius of the emission source is one day since the epoch span used in this work is one day. The mass of the black holes at the centers of these sources is found to be less than or equal to 108 solar masses, respectively.

Keywords: active galaxies, variability, Seyfert galaxies, SDSS, WISE

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Authors: Karoline Reis de Sena

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Endocrine disruptors are unregulated or not fully regulated compounds, even in the most developed countries, and which can be a danger to the environment and human health. They pass untreated through the secondary stage of conventional wastewater treatment plants, then the effluent from the wastewater treatment plants is discharged into the rivers, upstream and downstream from the drinking water treatment plants that use the same river water as the tributary. Long-term consumption of drinking water containing low concentrations of these compounds can cause health problems; these are persistent in nature and difficult to remove. In this way, research on emerging pollutants is expanding and is fueled by progress in finding the appropriate method for treating wastewater. Adsorption is the most common separation process, it is a simple and low-cost operation, but it is not eco-efficient. Concomitant to this, biosorption arises, which is a subcategory of adsorption where the biosorbent is biomass and which presents numerous advantages when compared to conventional treatment methods, such as low cost, high efficiency, minimization of the use of chemicals, absence of need for additional nutrients, biosorbent regeneration capacity and the biomass used in the production of biosorbents are found in abundance in nature. Thus, the use of alternative materials, such as sewage sludge, for the synthesis of adsorbents has proved to be an economically viable alternative, together with the importance of valuing the generated by-product flows, as well as managing the problem of their correct disposal. In this work, an alternative for the management of sewage sludge is proposed, transforming it into activated carbon and using it in the adsorption process of 17a-ethinylestradiol.

Keywords: 17α-ethinylestradiol, adsorption, activated carbon, sewage sludge, micropollutants

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Authors: Arlett A. Rosado-Torres, Ismael Marino-Tapia

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Changes in benthic cover of coral dominated systems to macroalgae dominance are widely studied worldwide. Watershed pollutants are potentially as important as overfishing causing phase shift. In certain regions of the world most of the continental inputs are through submarine groundwater discharges (SGD), which can play a significant ecological role because the concentration of its nutrients is usually greater that the one found in surface seawater. These stressors have adversely affected coral reefs, particularly in the Caribbean. Measurements of benthic cover (with video tracing, through a Go Pro camera), reef roughness (acoustic estimates with an Acoustic Doppler Current Velocity profiler and a differential GPS), thermohaline conditions (conductivity-temperature-depth (CTD) instrument) and nutrient measurements were taken in different sites in the reef lagoon of Puerto Morelos, Q. Roo, Mexico including those with influence of SGD and without it. The results suggest a link between SGD, macroalgae cover and structural complexity. Punctual water samples and data series from a CTD Diver confirm the presence of the SGD. On the site where the SGD is, the macroalgae cover is larger than in the other sites. To establish a causal link between this phase shift and SGD, the DELFT 3D hydrodynamic model (FLOW and WAVE modules) was performed under different environmental conditions and discharge magnitudes. The model was validated using measurements of oceanographic instruments anchored in the lagoon and forereef. The SGD is consistently favoring macroalgae populations and affecting structural complexity of the reef.

Keywords: hydrodynamic model, macroalgae, nutrients, phase shift

Procedia PDF Downloads 149

Authors: Chidiebere C. Agoha, Chukwuebuka N. Onwubuariri, Collins U.amasike, Tochukwu I. Mgbeojedo, Joy O. Njoku, Lawson J. Osaki, Ifeyinwa J. Ofoh, Francis B. Akiang, Dominic N. Anuforo

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In order to interpret the airborne magnetic data and evaluate the approximate location, depth, and geometry of the magnetic sources within Obudu area using the standard Euler deconvolution method, very high-resolution aeromagnetic data over the area was acquired, processed digitally and analyzed using Oasis Montaj 8.5 software. Data analysis and enhancement techniques, including reduction to the equator, horizontal derivative, first and second vertical derivatives, upward continuation and regional-residual separation, were carried out for the purpose of detailed data Interpretation. Standard Euler deconvolution for structural indices of 0, 1, 2, and 3 was also carried out and respective maps were obtained using the Euler deconvolution algorithm. Results show that the total magnetic intensity ranges from -122.9nT to 147.0nT, regional intensity varies between -106.9nT to 137.0nT, while residual intensity ranges between -51.5nT to 44.9nT clearly indicating the masking effect of deep-seated structures over surface and shallow subsurface magnetic materials. Results also indicated that the positive residual anomalies have an NE-SW orientation, which coincides with the trend of major geologic structures in the area. Euler deconvolution for all the considered structural indices has depth to magnetic sources ranging from the surface to more than 2000m. Interpretation of the various structural indices revealed the locations and depths of the source bodies and the existence of geologic models, including sills, dykes, pipes, and spherical structures. This area is characterized by intrusive and very shallow basement materials and represents an excellent prospect for solid mineral exploration and development.

Keywords: Euler deconvolution, horizontal derivative, Obudu, structural indices

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Authors: Sonja Djilas, Aleksandra Velićanski, Dragoljub Cvetković, Siniša Markov, Eva Lončar, Vesna Tumbas Šaponjac, Milica Vinčić

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Due to high content of bioactive compounds, sour cherry possesses antioxidant and antimicrobial activity. Additionally, waste material from industrial processing of sour cherry is also a good source of bioactive compounds. The aim of this study was to screen the antimicrobial activity and determine the minimal inhibitory (MIC) and minimal bactericidal concentrations (MBC) of sour cherry pomace extract. Tested strains were Gram-negative bacteria (Escherichia coli ATCC 25922, Salmonella typhimurium ATCC 14028 and wild isolates Escherichia coli and Salmonella sp.), Gram-positive bacteria (Staphylococcus aureus ATCC 11632, Bacillus cereus ATCC 10876 and wild isolates Staphylococcus saprophyticus and Bacillus sp.) and yeasts (Saccharomyces cerevisiae 112, Hefebank Weihenstephan and Candida albicans ATCC 10231). Antimicrobial activity was tested by disc-diffusion method and agar-well diffusion method. MIC and MBC were determined by microdilution method. Screening tests showed that Gram-negative bacteria were resistant to tested extract, with exception of Salmonella typhimurium and Salmonella sp. for which only zones of reduced growth appeared. However, Gram-positive bacteria were more sensitive where the highest clear zones appeared with 100 µl of extract applied. There was no activity against tested yeasts. MIC and MBC values were in the range 3.125-37.5 mg/ml and 6.25-100 mg/ml, respectively. The most susceptible strain was Staphylococcus aureus while the most resistant was Bacillus sp. where MBC was not found in tested concentration range. Sour cherry pomace possesses high antibacterial potential, which indicates that this waste material is a promising source of bioactive compounds and could be used as a functional food ingredient.

Keywords: antimicrobial activity, sour cherry, pomace, bioactive compounds

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Authors: Shima Naderi, Abbas Abbaszadeh Shahri

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Energy resources are reachable and affordable in Iran, thus surplus access to fossil fuels besides high level of economic growth leads to serious environmental critical such as pollutants and greenhouse gases in the atmosphere, increase in average degrease and lack of water sources specially in Tehran as a capital city of Iran. As building sector consumes a huge portion of energy, taking actions towards alternative sources of energy as well as conserving non-renewable energy resources and architectural energy saving methods are the fundamental basis for achieving sustainability`s goals. This study tries to explore implantation of both high technologies and traditional issues for reduction of energy demands in buildings of Tehran and introduce some factors and instructions for achieving this purpose. Green and energy efficient buildings such as ZEBs make it possible to preserve natural resources for the next generations by reducing pollution and increasing ecosystem self-recovery. However ZEB is not widely spread in Iran because of its low economic efficiency, it is not viable for a private entrepreneur without the governmental supports. Therefore executing of Architectural Energy Efficiency can be a better option. It is necessary to experience a substructure expansion with respect to traditional residential building style. Renewable energies and passive design which are the substantial part of the history of architecture in Iran can be regenerated and employed as an essential part of designing energy efficient buildings.

Keywords: architectural energy efficiency, passive design, renewable energies, zero energy buildings

Procedia PDF Downloads 355

Authors: Gordana Ćetković, Sanja Podunavac-Kuzmanović, Jasna Čanadanović-Brunet, Vesna Tumbas Šaponjac, Vanja Šeregelj, Jelena Vulić, Slađana Stajčić

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The color of food is one of the decisive factors for consumers. Potential toxicity of artificial food colorants has led to the consumers' preference for natural products over products with artificial colors. Natural pigments have many bioactive functions, such as antioxidant, provitamin and many other. Having this in mind, the acceptability of natural colorants by the consumers is much higher. Being present in all photosynthetic plant tissues carotenoids are probably most widespread pigments in nature. Carrot (Daucus carota) is a good source of functional food components. Carrot is especially rich in carotenoids, mainly α- and β-carotene and lutein. For this study, carrot was extracted using classical extraction with hexane and ethyl acetate, as well as supercritical CO₂ extraction. The extraction efficiency was evaluated by estimation of carotenoid yield determined spectrophotometrically. Classical extraction using hexane (18.27 mg β-carotene/100 g DM) was the most efficient method for isolation of carotenoids, compared to ethyl acetate classical extraction (15.73 mg β-carotene/100 g DM) and supercritical CO₂ extraction (0.19 mg β-carotene/100 g DM). Three carrot extracts were tested in terms of antioxidant activity using DPPH and reducing power assay as well. Surprisingly, ethyl acetate extract had the best antioxidant activity on DPPH radicals (AADPPH=120.07 μmol TE/100 g) while hexane extract showed the best reducing power (RP=1494.97 μmol TE/100 g). Hexane extract was chosen as the most potent source of carotenoids and was encapsulated in whey protein by freeze-drying. Carotenoid encapsulation efficiency was found to be high (89.33%). Based on our results it can be concluded that carotenoids from carrot can be efficiently extracted using hexane and classical extraction method. This extract has the potential to be applied in encapsulated form due to high encapsulation efficiency and coloring capacity. Therefore it can be used for dietary supplements development and food fortification.

Keywords: carotenoids, carrot, extraction, encapsulation

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Authors: Ateeth Shetty, K. S. Jayappa, Ratheesh Ramakrishnan, A. S. Rajawat

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Suspended Sediment Concentration (SSC) was estimated for the period of four months (November, 2013 to February 2014) using Oceansat-2 (Ocean Colour Monitor) satellite images to understand the coastal dynamics and regional sediment transport, especially distribution and budgeting in coastal waters. The coastal zone undergoes continuous changes due to natural processes and anthropogenic activities. The importance of the coastal zone, with respect to safety, ecology, economy and recreation, demands a management strategy in which each of these aspects is taken into account. Monitoring and understanding the sediment dynamics and suspended sediment transport is an important issue for coastal engineering related activities. A study of the transport mechanism of suspended sediments in the near shore environment is essential not only to safeguard marine installations or navigational channels, but also for the coastal structure design, environmental protection and disaster reduction. Such studies also help in assessment of pollutants and other biological activities in the region. An accurate description of the sediment transport, caused by waves and tidal or wave-induced currents, is of great importance in predicting coastal morphological changes. Satellite-derived SSC data have been found to be useful for Indian coasts because of their high spatial (360 m), spectral and temporal resolutions. The present paper outlines the applications of state‐of‐the‐art operational Indian Remote Sensing satellite, Oceansat-2 to study the dynamics of sediment transport.

Keywords: suspended sediment concentration, ocean colour monitor, sediment transport, case – II waters

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Authors: Trevor Malambo Simbayi, Diane Hildebrandt, Tonderayi Matambo

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The rapid growth of population in recent decades has resulted in an increased need for energy to meet human activities. As energy demands increase, the need for other sources of energy other than fossil fuels, increases in turn. Furthermore, environmental concerns such as global warming due to the use of fossil fuels, depleting fossil fuel reserves and the rising cost of oil have contributed to an increased interest in renewables sources of energy. Biogas is a renewable source of energy produced through the process of anaerobic digestion (AD) and it offers a two-fold solution; it provides an environmentally friendly source of energy and its production helps to reduce the amount of organic waste taken to landfills. This research seeks to address the waste management problem caused by an aquatic weed called water hyacinth (Eichhornia crassipes) at the Hartbeespoort (Harties) Dam in the North West Province of South Africa, through biogas production of the weed. Water hyacinth is a category 1 invasive species and it is deemed to be the most problematic aquatic weed. This weed is said to double its size in the space of five days. Eutrophication in the Hartbeespoort Dam has manifested itself through the excessive algae bloom and water hyacinth infestation. A large amount of biomass from water hyacinth and algae are generated per annum from the two hundred hectare surface area of the dam exposed to the sun. This biomass creates a waste management problem. Water hyacinth when in full bloom can cover nearly half of the surface of Hartbeespoort Dam. The presence of water hyacinth in the dam has caused economic and environmental problems. Economic activities such as fishing, boating, and recreation, are hampered by the water hyacinth’s prolific growth. This research proposes the use of water hyacinth as a feedstock or substrate for biogas production in order to find an economic and environmentally friendly means of waste management for the communities living around the Hartbeespoort Dam. In order to achieve this objective, water hyacinth will be collected from the dam and it will be mechanically pretreated before anaerobic digestion. Pretreatment is required for lignocellulosic materials like water hyacinth because such materials are called recalcitrant solid materials. Cow manure will be employed as a source of microorganisms needed for biogas production to occur. Once the water hyacinth and the cow dung are mixed, they will be placed in laboratory anaerobic reactors. Biogas production will be monitored daily through the downward displacement of water. Characterization of the substrates (cow manure and water hyacinth) to determine the nitrogen, sulfur, carbon and hydrogen, total solids (TS) and volatile solids (VS). Liquid samples from the anaerobic digesters will be collected and analyzed for volatile fatty acids (VFAs) composition by means of a liquid gas chromatography machine.

Keywords: anaerobic digestion, biogas, waste management, water hyacinth

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Authors: Bartosz Osiecki, Jane Liu

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Pollutants emitted from forest fires such as PM₂.₅ and carbon monoxide (CO) have been found to impact the air quality of distant regions through long-range transport. PM₂.₅ is of particular concern due to its transport capacity and implications for human respiratory and cardiovascular health. As such, significant increases in PM₂.₅ concentrations have been exhibited in urban areas downwind of fire sources. This study seeks to expand on this literature by evaluating the impacts of long-range forest fire emission transport on air quality in Toronto, Ontario, as a means of evaluating the vulnerability of this major urban center to distant fire events. In order to draw correlations between the fire event and air pollution episode in Toronto, MODIS fire count data and HYPLSIT trajectories are used to assess the date, location, and severity of the fire and track the trajectory of emissions (respectively). Forward and back-trajectories are run, terminating at the West Toronto air monitoring station. PM₂.₅ and CO concentrations in Toronto during September 2017 are found to be significantly elevated, which is likely attributable to the fire activity. Other sites in Ontario including Toronto (East, North, Downtown), Mississauga, Brampton, and Hamilton (Downtown) exhibit similar peaks in PM₂.₅ concentrations. This work sheds light on the non-local, natural factors influencing air quality in urban areas. This is especially important in the context of climate change which is expected to exacerbate intense forest fire events in the future.

Keywords: air quality, forest fires, PM₂.₅, Toronto

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Authors: Emile Niringiyimana, LI Ji Qing, Giovanni Dushimimana, Virginie Umwere

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The development and utilization of renewable energy (RE) can not only effectively reduce carbon dioxide (CO2) emissions, but also became a solution to electricity shortage mitigation in rural areas. Hybrid RE systems are promising ways to provide consistent and continuous power for isolated areas. This work investigated the prospect and cost effectiveness of hybrid system complementarity between a 100kW solar PV system and a small-scale 200kW hydropower station in the South of Rwanda. In order to establish the optimal size of a RE system with adequate sizing of system components, electricity demand, solar radiation, hydrology, climate data are utilized as system input. The average daily solar radiation in Rukarara is 5.6 kWh/m2 and average wind speed is 3.5 m/s. The ideal integrated RE system, according to Homer optimization, consists of 91.21kW PV, 146kW hydropower, 12 x 24V li-ion batteries with a 20kW converter. The method of enhancing such hybrid systems control, sizing and choice of components is to reduce the Net present cost (NPC) of the system, unmet load, the cost of energy and reduction of CO2. The power consumption varies according to dominant source of energy in the system by controlling the energy compensation depending on the generation capacity of each power source. The initial investment of the RE system is $977,689.25, and its operation and maintenance expenses is $142,769.39 over a 25-year period. Although the investment is very high, the targeted profits in future are huge, taking into consideration of high investment in rural electrification structure implementations, tied with an increase of electricity cost and the 5 years payback period. The study outcomes suggest that the standalone hybrid PV-Hydropower system is feasible with zero pollution in Rukara community.

Keywords: HOMER optimization, hybrid power system, renewable energy, NPC and solar pv systems

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Authors: Katarzyna Socha, Konrad Mielcarek, Grzegorz Kangowski, Renata Markiewicz-Zukowska, Anna Puscion-Jakubik, Jolanta Soroczynska, Maria H. Borawska

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Nuts have high nutritional value. They are a good source of polyunsaturated fatty acids, dietary fiber, vitamins (B₁, B₆, E, K) and minerals: magnesium, selenium, zinc (Zn). Zn is an essential element for proper functioning and development of human organism. Due to antioxidant and anti-inflammatory properties, Zn has an influence on immunological and central nervous system. It also affects proper functioning of reproductive organs and has beneficial impact on the condition of skin, hair, and nails. The objective of this study was estimation of Zn content in edible nuts. The research material consisted of 10 types of nuts, 12 samples of each type: almonds, brazil nuts, cashews, hazelnuts, macadamia nuts, peanuts, pecans, pine nuts, pistachios, and walnuts. The samples of nuts were digested in concentrated nitric acid using microwave mineralizer (Berghof, Germany). The concentration of Zn was determined by flame atomic absorption spectrometry method with Zeeman background correction (Hitachi, Japan). The accuracy of the method was verified on certified reference material: Simulated Diet D. The statistical analysis was performed using Statistica v. 13.0 software. For comparison between the groups, t-Student test was used. The highest content of Zn was shown in pine nuts and cashews: 78.57 ± 21.9, 70.02 ± 10,2 mg/kg, respectively, significantly higher than in other types of nuts. The lowest content of Zn was found in macadamia nuts: 16.25 ± 4.1 mg/kg. The consumption of a standard 42-gram portion of almonds, brazil nuts, cashews, peanuts, pecans, and pine nuts covers the daily requirement for Zn above 15% of recommended daily allowances (RDA) for women, while in the case of men consumption all of the above types of nuts, except peanuts. Selected types of nuts can be a good source of Zn in the diet.

Keywords: atomic absorption spectrometry, microelement, nuts, zinc

Procedia PDF Downloads 186

Authors: Yifan Lu, Ying Cui, Ying Zhu, Edward S. Lu, Rebecca Zeng, Rohan Bajaj, Raviv Katz, Rongrong Le, Jay C. Wang, John B. Miller

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Purpose: Retinal artery occlusion (RAO) is an ophthalmic emergency that can lead to poor visual outcome and is associated with an increased risk of cerebral stroke and cardiovascular events. Fluorescein angiography (FA) is the traditional diagnostic tool for RAO; however, wide-field swept-source optical coherence tomography angiography (WF SS-OCTA), as a nascent imaging technology, is able to provide quick and non-invasive angiographic information with a wide field of view. In this study, we looked for associations between OCT-A vascular metrics and visual acuity in patients with prior diagnosis of RAO. Methods: Patients with diagnoses of central retinal artery occlusion (CRAO) or branched retinal artery occlusion (BRAO) were included. A 6mm x 6mm Angio and a 15mm x 15mm AngioPlex Montage OCT-A image were obtained for both eyes in each patient using the Zeiss Plex Elite 9000 WF SS-OCTA device. Each 6mm x 6mm image was divided into nine Early Treatment Diabetic Retinopathy Study (ETDRS) subfields. The average measurement of the central foveal subfield, inner ring, and outer ring was calculated for each parameter. Non-perfusion area (NPA) was manually measured using 15mm x 15mm Montage images. A linear regression model was utilized to identify a correlation between the imaging metrics and visual acuity. A P-value less than 0.05 was considered to be statistically significant. Results: Twenty-five subjects were included in the study. For RAO eyes, there was a statistically significant negative correlation between vision and retinal thickness as well as superficial capillary plexus vessel density (SCP VD). A negative correlation was found between vision and deep capillary plexus vessel density (DCP VD) without statistical significance. There was a positive correlation between vision and choroidal thickness as well as choroidal volume without statistical significance. No statistically significant correlation was found between vision and the above metrics in contralateral eyes. For NPA measurements, no significant correlation was found between vision and NPA. Conclusions: This is the first study to our best knowledge to investigate the utility of WF SS-OCTA in RAO and to demonstrate correlations between various retinal vascular imaging metrics and visual outcomes. Further investigations should explore the associations between these imaging findings and cardiovascular risk as RAO patients are at elevated risk for symptomatic stroke. The results of this study provide a basis to understand the structural changes involved in visual outcomes in RAO. Furthermore, they may help guide management of RAO and prevention of cerebral stroke and cardiovascular accidents in patients with RAO.

Keywords: OCTA, swept-source OCT, retinal artery occlusion, Zeiss Plex Elite

Procedia PDF Downloads 135

Authors: Atousa Ataieyan, Salvador A. Gomez-Lopera, Gennaro Sepede

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Today, due to the growing urban population and consequently, the increasing water demand in cities, the amount of contaminants entering the water resources is increasing. This can impose harmful effects on the quality of the downstream water. Therefore, predicting the concentration of discharged pollutants at different times and distances of the interested area is of high importance in order to carry out preventative and controlling measures, as well as to avoid consuming the contaminated water. In this paper, the concentration distribution of an injected conservative pollutant in a square reservoir containing four symmetric blocks and three sources using Finite Volume Method (FVM) is simulated. For this purpose, after estimating the flow velocity, classical Advection-Diffusion Equation (ADE) has been discretized over the studying domain by Backward Time- Backward Space (BTBS) scheme. Then, the discretized equations for each node have been derived according to the initial condition, boundary conditions and point contaminant sources. Finally, taking into account the appropriate time step and space step, a computational code was set up in MATLAB. Contaminant concentration was then obtained at different times and distances. Simulation results show how using BTBS differentiating scheme and FVM as a numerical method for solving the partial differential equation of transport is an appropriate approach in the case of two-dimensional contaminant transfer in an advective-diffusive flow.

Keywords: BTBS differentiating scheme, contaminant concentration, finite volume, mass transfer, water pollution

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Authors: I. Kerti, G. Sezen, S. Daglilar

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This present work is focused on studying to improve low wetting behaviour between liquid metal and ceramic particles. Ceramic particles like SiC and B4C have attracted great attention because of their usability as reinforcement for composite materials. However, poor wettability of particles is one of the major drawbacks of metal matrix composite production. Various methods have been studied to enhance the wetting properties between ceramic materials and metal substrates during ceramic reinforced metal matrix composites. Among these methods, autocatalytic nickel deposition is a unique process for the enhancement of the surface properties of ceramic particles. In fact, it is difficult to obtain continuous and uniform metallic coating on ceramic powders. In this study deposition of nickel boron layer on ceramic particles via autocatalytic plating in borohydride baths were investigated. Firstly, powders with different particle sizes were sensitized and activated respectively in order to ensure catalytic properties. Following the pre-treatment operations, particles were transferred into the coating bath containing nickel sulphate or nickel chloride as the Ni2+ source. The results show that a better bonding and uniform coating layer were obtained for Ni-B coatings with the Ni2+ source of NiCl2.6H2O as compared to NiSO4.6H2O. With the progress of the time, both particle surfaces are completely covered by a continuous and thin nickel boron layer. The surface morphology of the coatings that were analysed using scanning electron microscopy (SEM) show that SiC and B4C particles both distributed and different thickness of Ni-B nanolayers have been successfully coated onto the particles. The particles were mounted into a polimeric resin and polished in order to observe the thickness and the continuity of the coating layer. The composition of the coating layers were also evaluated by EDS analyses. The SEM morphologies and the EDS results of the coatings at different reaction times were adopted for detailed discussion of the Ni-B electroless plating mechanism.

Keywords: boron carbide, electroless coating, nickel boron deposition, silicon carbide

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Authors: Joanna Styczen, Wojciech Franus

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Currently, cement production reaches 3-6 Gt per year. The production of one ton of cement is associated with the emission of 0.5 to 1 ton of carbon dioxide into the atmosphere, which means that this process is responsible for 5% of global CO2 emissions. Simply improving the cement manufacturing process is not enough. An effective solution is the use of pozzolanic materials, which can partly replace clinker and thus reduce energy consumption, and emission of pollutants and give mortars the desired characteristics, shaping their microstructure. Pozzolanic additives modify the phase composition of cement, reducing the amount of portlandite and changing the CaO/SiO2 ratio in the C-S-H phase. Zeolites are a pozzolanic additive that is not commonly used. Three types of zeolites were synthesized in work: Na-A, sodalite and ZSM-5 (these zeolites come from three different structural groups). Zeolites were obtained by hydrothermal synthesis of fly ash in an aqueous NaOH solution. Then, the pozzolanicity of the obtained materials was assessed. The pozzolanic activity of the zeolites synthesized for testing was tested by chemical methods in accordance with the ASTM C 379-65 standard. The method consisted in determining the percentage content of active ingredients (soluble silicon oxide and aluminum).in alkaline solutions, i.e. those that are potentially reactive towards calcium hydroxide. The highest amount of active silica was found in zeolite ZSM-5 - 88.15%. The amount of active Al2O3 was small - 1%. The smallest pozzolanic activity was found in the Na-A zeolite (active SiO2 - 4.4%, and active Al2O3 - 2.52). The tests carried out using the XRD, SEM, XRF and textural tests showed that the obtained zeolites are characterized by high porosity, which makes them a valuable addition to mortars.

Keywords: pozzolanic properties, hydration, zeolite, alite

Procedia PDF Downloads 72

Authors: Zohreh Fallah, Edward P. L. Roberts

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One of the big challenges for produced water treatment is removing oil from water in the form of emulsified droplets which are not easily separated. An attractive approach is adsorption, as it is a simple and effective process. However, adsorbents must be regenerated in order to make the process cost effective. Several sorbents have been tested for treating oily wastewater. However, some issues such as high energy consumption for activated carbon thermal regeneration have been reported. Due to their significant electrical conductivity, Graphite Intercalation Compounds (GIC) were found to be suitable to be regenerated electrochemically. They are non-porous materials with low surface area and fast adsorptive capacity which are useful for removal of low concentration of organics. An innovative adsorption/regeneration process has been developed at the University of Manchester in which adsorption of organics are done by using a patented GIC adsorbent coupled with subsequent electrochemical regeneration. The oxidation of adsorbed organics enables 100% regeneration so that the adsorbent can be reused over multiple adsorption cycles. GIC adsorbents are capable of removing a wide range of organics and pollutants; however, no comparable report is available for removal of emulsified oil in produced water using abovementioned process. In this study the performance of this technology for the removal of emulsified oil in wastewater was evaluated. Batch experiments were carried out to determine the adsorption kinetics and equilibrium isotherm for both real produced water and model emulsions. The amount of oil in wastewater was measured by using the toluene extraction/fluorescence analysis before and after adsorption and electrochemical regeneration cycles. It was found that oil in water emulsion could be successfully treated by the treatment process and More than 70% of oil was removed.

Keywords: adsorption, electrochemical regeneration, emulsified oil, produced water

Procedia PDF Downloads 577

Authors: E. A. Abdel-Hakim

Abstract:

The corn stemborer Sesamia cretica (Lederer), has been viewed in many parts of the world as a major pest of cultivated maize, graminaceous crops and sugarcane. Its life cycle is comprised of two different phases, one is the growth and developmental phase (non-diapause) and the other is diapause phase which takes place at the last larval instar. Several problems associated with the use of conventional insecticides, have strongly demonstrated the need for applying alternative safe compounds. Prominent among the prototypes of such prospective chemicals are the juvenoids; i.e. the insect (JH) mimics. In fact, the hormonal effect on metabolism has long been viewed as a secondary consequence of its direct action on specific energy-requiring biosynthetic mechanisms. Therefore, the present study was undertaken essentially in a rather systematic fashion as a contribution towards clarifying metabolic and energetic changes taking place during non-diapause wandering larvae as regulated by (JH) mimic. For this purpose, we applied two different doses of JH mimic (Ro 11-0111) in a single (standard) dose of 100µg or in a single dose of 20 µg/g bw in1µl acetone topically at the onset of nondiapause wandering larvae (WL). Energetic data were obtained by indirect calorimetry methods by conversion of respiratory gas exchange volumetric data, as measured manometrically using a Warburg constant respirometer, to caloric units (g-cal/g fw/h). The findings obtained can be given in brief; these treated larvae underwent supernumerary larval moults. However, this potential the wandering larvae proved to possess whereby restoration of larval programming for S. cretica to overcome stresses even at this critical developmental period. The results obtained, particularly with the high dose used, show that 98% wandering larvae were rescued to survive up to one month (vs. 5 days for normal controls), finally the formation of larval-adult intermediates. Also, the solvent controls had resulted in about 22% additional, but stationary moultings. The basal respiratory metabolism (O2 uptake and CO2 output) of the (WL), whether un-treated or larvae not had followed reciprocal U-shaped curves all along of their developmental duration. The lowest points stood nearly to the day of prepupal formation (571±187 µl O2/gfw/h and 553±181 µl CO2/gfw/h) during un-treated in contrast to the larvae treated with JH (210±48 µl O2/gfw/h and 335±81 µl CO2/gfw/h). Un-treated (normal) larvae proved to utilize carbohydrates as the principal source for energy supply; being fully oxidised without sparing any appreciable amount for endergonic conversion to fats. While, the juvenoid-treated larvae and compared with the acetone-treated control equivalents, there existed no distinguishable differences between them; both had been observed utilising carbohydrates as the sole source of energy demand and converting endergonically almost similar percentages to fats. The overall profile, treated and un-treated (WL) utilized carbohydrates as the principal source for energy demand during this stage.

Keywords: juvenile hormone, respiratory metabolism, Sesamia cretica, wandering phase

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Authors: G. Medkour Ishak-Boushaki, A. Taibi, M. Allab

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Quantitative environmental radioactivity measurements are needed to determine the level of exposure of a population to ionizing radiations and for the assessment of the associated risks. Gamma spectrometry remains a very powerful tool for the analysis of radionuclides present in an environmental sample but the basic problem in such measurements is the low rate of detected events. Using large environmental samples could help to get around this difficulty but, unfortunately, new issues are raised by gamma rays attenuation and self-absorption. Recently, a new method has been suggested, to detect and identify without quantification, in a short time, a gamma ray of a low count source. This method does not require, as usually adopted in gamma spectrometry measurements, a pulse height spectrum acquisition. It is based on a chronological record of each detected photon by simultaneous measurements of its energy ε and its arrival time τ on the detector, the pair parameters [ε,τ] defining an event mode sequence (EMS). The EMS serials are analyzed sequentially by a Bayesian approach to detect the presence of a given radioactive source. The main object of the present work is to test the applicability of this sequential approach in radioactive environmental materials detection. Moreover, for an appropriate health oversight of the public and of the concerned workers, the analysis has been extended to get a reliable quantification of the radionuclides present in environmental samples. For illustration, we consider as an example, the problem of detection and quantification of 238U. Monte Carlo simulated experience is carried out consisting in the detection, by a Ge(Hp) semiconductor junction, of gamma rays of 63 keV emitted by 234Th (progeny of 238U). The generated EMS serials are analyzed by a Bayesian inference. The application of the sequential Bayesian approach, in environmental radioactivity analysis, offers the possibility of reducing the measurements time without requiring large environmental samples and consequently avoids the attached inconvenient. The work is still in progress.

Keywords: Bayesian approach, event mode sequence, gamma spectrometry, Monte Carlo method

Procedia PDF Downloads 493