Search results for: bacterial composition
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 3586

Search results for: bacterial composition

1186 Effect of Heat Treatment on Columnar Grain Growth and Goss Texture on Surface in Grain-Oriented Electrical Steels

Authors: Jungkyun Na, Jaesang Lee, Yang Mo Koo

Abstract:

In this study to find a replacement for expensive secondary recrystallization in GO electrical steel production, effect of heat treatment on the formation of columnar grain and Goss texture is investigated. The composition of the sample is Fe-2.0Si-0.2C. This process involves repeating of cold rolling and decarburization as a replacement for secondary recrystallization. By cold-rolling shear band is made and Goss grain grows from shear band by decarburization. By doing another cold rolling, some Goss texture is newly formed from the shear band, and some Goss texture is retained in microbands. To determine whether additional heat treatment with H2 atmosphere is needed on decarburization process for growth of Goss texture, comparing between decarburization and heat treatment with H2 atmosphere is performed. Also, to find optimum condition for heat treatment, heat treatment with various time and temperature is performed. It was found that increase in the number of cold rolling and heat treatment increases Goss texture. Both high Goss texture and good columnar structure is achieved at 900℃, and this temperature is within a+r phase region. Heat treatment at a temperature higher than a+r phase region caused carbon diffusion and this made layer with Goss grain decrease.

Keywords: electrical steel, Goss texture, columnar structure, normal grain growth

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1185 The Mechanical Characteristics of Rammed Earth with Plastic Fibers

Authors: Majdi Al Shdifat, Juan Chiachio, Esther Puertas, María L. Jalón, Álvaro Blanca-Hoyos

Abstract:

In recent years, the world has begun to adopt more sustainable practices in response to today's environmental and climate challenges. The construction sector is one of the most resource-intensive among others, so researchers are testing different types of materials with different processes and methodologies to achieve more environmentally and sustainably friendly buildings. Plastic is one of the most harmful materials for the environment. The global production of plastics has increased dramatically in recent decades, and it is one of the most widely used materials. However, plastic waste is not biodegradable and has a chemical composition that is stable for many years in the environment, both on land and in water bodies. Recycled plastics have been tested to be used in construction in many ways to reduce the amount of plastic in the environment and the use of raw materials in construction. In this context, the main objective of this research is to test the use of plastic fibers with one of the most promising materials to replace cement, which is rammed earth. In fact, rammed earth is considered one of the most environmentally friendly materials due to its use of local raw materials, recyclability, and low embodied energy. In this research, three different types of plastic fibers were used. Then, the blends were evaluated by considering their mechanical properties, including compressive strength and tensile strength. In addition, the non-destructive ultrasonic wave velocity was measured. The result shows excellent potential for the use of plastic fibers in rammed earth, especially in terms of compressive strength.

Keywords: mechanical characterization, plastic fibers reinforcement, rammed earth, sustainable material

Procedia PDF Downloads 53
1184 Optical and Luminescence Studies on Dy³+ Singly Doped and Dy³+/Ce³+ Co-doped Alumina Borosilicate Glasses for Photonics Device Application

Authors: M. Monisha, Sudha D. Kamath

Abstract:

We investigate the optical and photoluminescence properties from Dy³+ singly doped and Dy³+ co-doped with Ce³+alumino borosilicate glasses prepared using high temperature melt-quenching technique. The glass composition formula is 25SiO₂-(40-x-y)B2O₃-10Al₂O₃-15NaF-10ZnO-xDy₂O₃ yCe₂O₃ where, x = 0.5 mol% and y = 0, 0.1, and 0.5 mol%. The XRD study reveals the amorphous nature of both singly doped and co-doped glasses. Absorption study on Dy3+ singly doped glass shows nearly twelve absorption peaks arising from the ground level of Dy³+ ions (⁶H₁₅/₂) to various upper levels, and for Dy³+/Ce³+ co-doped glasses, few of the transitions in the visible region are suppressed. The absorption band edge is shifted towards the higher wavelength region on increasing Ce3+concentration. The decrease in indirect energy bandgap and increase in Urbach energy of the prepared glasses is observed due to codoping with Ce3+ ions. The photoluminescence studies on singly doped glass under 350 nm excitation showed three peaks at the blue (482 nm), yellow (575 nm), and red (663 nm) region. For codoped glasses, the emission peak at 403 nm is raised due to the 4d to 5f transition of Ce3+ ions. Lifetime values (ms) of co-doped glass is found to be higher than singly doped glass. Under 350 nm excitation, CIE coordinates of the co-doped glasses moved towards the bright white light region. The correlated color temperature (CCT) values were obtained in the range 4500 – 4700 K. Thus, the prepared glasses can be used for photonics device applications.

Keywords: absorption spectra, borosilicate glasses, Ce³+, Dy³+, photoluminescence

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1183 Ecotourism Sites in Central Visayas, Philippines: A Green Business Profile

Authors: Ivy Jumao-As, Randy Lupango, Clifford Villaflores, Marites Khanser

Abstract:

Alongside inadequate implementation of ecotourism standards and other pressing issues on sustainable development is the lack of business plans and formal business structures of various ecotourism sites in the Central Visayas, Philippines, and other parts of the country. Addressing these issues plays a key role to boost ecotourism which is a sustainability tool to the country’s economic development. A three-phase research is designed to investigate the green business practices of selected ecotourism sites in the region in order to propose a business model for ecotourism destinations in the region and outside. This paper reports the initial phase of the study which described the sites’ profile as well as operators of the following selected destinations: Cebu City Protected Landscape and Olango Island Wildlife Bird Sanctuary in Cebu, Rajah Sikatuna Protected Landscape in Bohol. Interview, Self-Administered Questionnaire with key informants and Data Mining were employed in the data collection. Findings highlighted similarities and differences in terms of eco-tourism products, type and number of visitors, manpower composition, cultural and natural resources, complementary services and products, awards and accreditation, peak and off peak seasons, among others. Recommendations based from common issues initially identified in this study are also highlighted.

Keywords: ecotourism, ecotourism sites, green business, sustainability

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1182 Occurrence and Geological Setting of the Black Shales Outcrops in Malaysia

Authors: Hassan M. Baioumy, Yuniarti Ulfa

Abstract:

Paleozoic, Mesozoic and Cenozoic black shales that can be a potential source of energy and precious metals are widely distributed in Malaysia Peninsula, Sarawak and Sabah. Two Paleozoic black shales outcrops were reported in the Langkawi Island belonging to the Cambrian fluvial Machinchang Formation and the Silurian glaciomarine Singa Formation. More the seventeen occurrences of Paleozoic black shales outcrops have been found in the Peninsular Malaysia that range in age from Devonian, Carboniferous, and Permian in the Terengganu, Perlis, Pahang, and Perak States. Mesozoic black shales outcrops occur in several places in both the Peninsular Malaysia and Sarawak. In the Peninsular Malaysia, Triassic black shales occur in the Nami area, Northern Kedah and in the Pahang area. In Sarawak, Triassic black shales have been reported in the Bau area. Cenozoic black shales outcrops were reported in both Sarawak at Miri area and Sabah at the Ranau and Tenom areas. Preliminary mineralogical and geochemical investigations on some of these black shales outcrops showed distinct compositional variations among these black shales outcrops probably due to variations in their source area composition and/or depositional and diagenetic settings of these shales. Some of these shalese also subjected to post-depositional hydrothermal mineralization that enriched these shales with Au-bearing minerals such as pyrite, calchopyrite, and arsenopyrite. Many of the studied black shales outcrops look rich in organic matter, which increase the possibility of using these black shales as an unconventional energy resource.

Keywords: black shales, energy, mineralization, Malaysia

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1181 Turmeric Mediated Synthesis and Characterization of Cerium Oxide Nanoparticles

Authors: Nithin Krisshna Gunasekaran, Prathima Prabhu Tumkur, Nicole Nazario Bayon, Krishnan Prabhakaran, Joseph C. Hall, Govindarajan T. Ramesh

Abstract:

Cerium oxide and turmeric have antioxidant properties, which have gained interest among researchers to study their applications in the field of biomedicine, such asanti-inflammatory, anticancer, and antimicrobial applications. In this study, the turmeric extract was prepared and mixed with cerium nitrate hexahydrate, stirred continuously to obtain a homogeneous solution and then heated on a hot plate to get the supernatant evaporated, then calcinated at 600°C to obtain the cerium oxide nanoparticles. Characterization of synthesized cerium oxide nanoparticles through Scanning Electron Microscopy determined the particle size to be in the range of 70 nm to 250 nm. Energy Dispersive X-Ray Spectroscopy determined the elemental composition of cerium and oxygen. Individual particles were identified through the characterization of cerium oxide nanoparticles using Field Emission Scanning Electron Microscopy, in which the particles were determined to be spherical and in the size of around 70 nm. The presence of cerium oxide was assured by analyzing the spectrum obtained through the characterization of cerium oxide nanoparticles by Fourier Transform Infrared Spectroscopy. The crystal structure of cerium oxide nanoparticles was determined to be face-centered cubic by analyzing the peaks obtained through theX-Ray Diffraction method. The crystal size of cerium oxide nanoparticles was determined to be around 13 nm by using the Debye Scherer equation. This study confirmed the synthesis of cerium oxide nanoparticles using turmeric extract.

Keywords: antioxidant, characterization, cerium oxide, synthesis, turmeric

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1180 Biomass and Biogas Yield of Maize as Affected by Nitrogen Rates with Varying Harvesting under Semi-Arid Condition of Pakistan

Authors: Athar Mahmood, Asad Ali

Abstract:

Management considerations including harvesting time and nitrogen application considerably influence the biomass yield, quality and biogas production. Therefore, a field study was conducted to determine the effect of various harvesting times and nitrogen rates on the biomass yield, quality and biogas yield of maize crop. This experiment was consisted of various harvesting times i.e., harvesting after 45, 55 and 65 days of sowing (DAS) and nitrogen rates i.e., 0, 100, 150 and 200 kg ha-1 respectively. The data indicated that maximum plant height, leaf area, dry matter (DM) yield, protein, acid detergent fiber, neutral detergent fiber, crude fiber contents and biogas yield were recorded 65 days after sowing while lowest was recorded 45 days after sowing. In contrary to that significantly higher chlorophyll contents were observed at 45 DAS. In case of nitrogen rates maximum plant height, leaf area, and DM yield, protein contents, ash contents, acid detergent fiber, neutral detergent fiber, crude fiber contents and chlorophyll contents were determined with nitrogen at the rate of 200 kg ha-1, while minimum was observed when no N was applied. Therefore, harvesting 65 DAS and N application @ 200 kg ha-1 can be suitable for getting the higher biomass and biogas production.

Keywords: chemical composition, fiber contents, biogas, nitrogen, harvesting time

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1179 Control System Design for a Simulated Microbial Electrolysis Cell

Authors: Pujari Muruga, T. K. Radhakrishnan, N. Samsudeen

Abstract:

Hydrogen is considered as the most important energy carrier and fuel of the future because of its high energy density and zero emission properties. Microbial Electrolysis Cell (MEC) is a new and promising approach for hydrogen production from organic matter, including wastewater and other renewable resources. By utilizing anode microorganism activity, MEC can produce hydrogen gas with smaller voltages (as low as 0.2 V) than those required for electrolytic hydrogen production ( ≥ 1.23 V). The hydrogen production processes of the MEC reactor are very nonlinear and highly complex because of the presence of microbial interactions and highly complex phenomena in the system. Increasing the hydrogen production rate and lowering the energy input are two important challenges of MEC technology. The mathematical model of the MEC is based on material balance with the integration of bioelectrochemical reactions. The main objective of the research is to produce biohydrogen by selecting the optimum current and controlling applied voltage to the MEC. Precise control is required for the MEC reactor, so that the amount of current required to produce hydrogen gas can be controlled according to the composition of the substrate in the reactor. Various simulation tests involving multiple set-point changes disturbance and noise rejection were performed to evaluate the performance using PID controller tuned with Ziegler Nichols settings. Simulation results shows that other good controller can provide better control effect on the MEC system, so that higher hydrogen production can be obtained.

Keywords: microbial electrolysis cell, hydrogen production, applied voltage, PID controller

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1178 Lipidomic Profiling of Chlorella sp. and Scenedesmus abundans towards Deciphering Phospholipids and Glycolipids under Nitrogen Limited Condition

Authors: J. Singh, Swati Dubey, R. P. Singh

Abstract:

Microalgal strains can accumulate greatly enhanced levels of lipids under nitrogen-deficient condition, making these as one of the most promising sustainable sources for biofuel production. High-grade biofuel production from microalgal biomass could be facilitated by analysing the lipid content of the microalgae and enumerating its dynamics under varying nutrient conditions. In the present study, a detailed investigation of changes in lipid composition in Chlorella species and Scenedesmus abundans in response to nitrogen limited condition was performed to provide novel mechanistic insights into the lipidome during stress conditions. The mass spectroscopic approaches mainly LC-MS and GC-MS were employed for lipidomic profiling in both the microalgal strains. The analyses of lipid profiling using LC-MS revealed distinct forms of lipids mainly phospho- and glycolipids, including betaine lipids, and various other forms of lipids in both the microalgal strains. As detected, an overall decrease in polar lipids was observed. However, GC-MS analyses had revealed that the synthesis of the storage lipid i.e. triacylglycerol (TAG) was substantially stimulated in both the strains under nitrogen limited conditions. The changes observed in the overall fatty acid profile were primarily due to the decrease in proportion of polar lipids to TAGs. This study had enabled in analysing a detailed and orchestrated form of lipidomes in two different microalgal strains having potential for biodiesel production.

Keywords: biofuel, GC-MS, LC-MS, lipid, microalgae

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1177 Evaluation of Different Fertilization Practices and Their Impacts on Soil Chemical and Microbial Properties in Two Agroecological Zones of Ghana

Authors: Ansong Richard Omari, Yosei Oikawa, Yoshiharu Fujii, Dorothea Sonoko Bellingrath-Kimura

Abstract:

Renewed interest in soil management aimed at improving the productive capacity of Sub Saharan Africa (SSA) soils has called for the need to analyse the long term effect of different fertilization systems on soil. This study was conducted in two agroecological zones (i.e., Guinea Savannah (GS) and Deciduous forest (DF)) of Ghana to evaluate the impacts of long term (> 5 years) fertilization schemes on soil chemical and microbial properties. Soil samples under four different fertilization schemes (inorganic, inorganic and organic, organic, and no fertilization) were collected from 20 farmers` field in both agroecological zones. Soil analyses were conducted using standard procedures. All average soil quality parameters except extractable C, potential mineralizable nitrogen and CEC were significantly higher in DF sites compared to GS. Inorganic fertilization proved superior in soil chemical and microbial biomass especially in GS zone. In GS, soil deterioration index (DI) revealed that soil quality deteriorated significantly (−26%) under only organic fertilization system whereas soil improvement was observed under inorganic and no fertilization sites. In DF, either inorganic or organic and inorganic fertilization showed significant positive effects on soil quality. The high soil chemical composition and enhanced microbial biomass in DF were associated with the high rate of inorganic fertilization.

Keywords: deterioration index, fertilization scheme, microbial biomass, tropical agroecological zone

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1176 Microbial Inoculants to Increase the Biomass and Nutrient Uptake of Tithonia Cultivated as Hedgerow Plants to Control Erosion in Ultisols

Authors: Nurhajati Hakim, Kiki Amalia, A. Agustian, H. Hermansah, Y. Yulnafatmawita

Abstract:

Ultisols require greater amounts of fertilizer application compared to other soils and susceptible to erosion. Unfortunately, the price of synthetic fertilizers has increased over time during the years, making them unaffordable for most Indonesian farmers. While terrace technique to control erosion very costly.Over the last century, efforts to reduce reliance on synthetic agro-chemicals fertilizers and erosion control have recently focused on Tithonia diversifolia as a fertilizer alternative, and as hedgerow plant to control erosion. Generally known by its common name of tree marigold or Mexican sunflower, this plant has attracted considerable attention for its prolific production of green biomass, rich in nitrogen, phosphorous and potassium (NPK). In pot experiments has founded some microbial such as Mycorrhizal, Azotobacter, Azospirillum, phosphate solubilizing bacterial (PSB) and fungi (PSF) are expected to play an important role in biomass production and high nutrient uptake of this plant. This issue of importance was pursued further in the following investigation in field condition. The aim of this study was to determine the type of microbial combination suitable for Tithonia cultivation as hedgerow plants in Ultisols which have higher biomass production and nutrient content, and decline soil erosion. The field experiment was conducted with 6 treatments in a randomized block design (RBD) using 3 replications. The treatments were: Tithonia rhizosphere without microbial inoculated (A); Inokulanted by Mycorrhizal + Azotobacter + Azospirillium (B); Mycorrhizal + PSF (C); Mycorrhizal + PSB(D); Mycorrhizal + PSB + PSF(E);and without hedgerow Tithonia (F).The microbial substrates were inoculated into the Tithonia rhizosphere in the nursery. The young Tithonia plants were then planted as hedgerow on Ultisols in the experimental field for 8 months, and pruned once every 2 months. Soil erosion were collected every rainy time. The differences between treatments were statistically significant by HSD test at the 95% level of probability. The result showed that treatment C (mycorrhizal + PSB) was the most effective, and followed by treatment D (mycorrhizal + PSF) in producing higher Tithonia biomass about 8 t dry matter 2000 m-2 ha-1 y-1 and declined soil erosion 71-75%.

Keywords: hedgerow tithonia, microbial inoculants, organic fertilizer, soil erosion control

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1175 The Mechanical Properties of Rammed Earth with Plastic Fibers

Authors: Majdi Al Shdifat, Juan Chiachio, Esther Puertas, María L. Jalón, Álvaro Blanca-Hoyos

Abstract:

In recent years, the world has begun to adopt more sustainable practices in response to today's environmental and climate challenges. The construction sector is one of the most resource-intensive among others, so researchers are testing different types of materials with different processes and methodologies to achieve more environmentally and sustainably friendly buildings.Plastic is one of the most harmful materials for the environment. The global production of plastics has increased dramatically in recent decades, and it is one of the most widely used materials. However, plastic waste is not biodegradable and has a chemical composition that is stable for many years in the environment, both on land and in water bodies. Recycled plastics have been tested to be used in construction in many ways to reduce the amount of plastic in the environment and the use of raw materials in construction. In this context, the main objective of this research is to test the use of plastic fibers with one of the most promising materials to replace cement, which is rammed earth. In fact, rammed earth is considered one of the most environmentally friendly materials due to its use of local raw materials, recyclability, and low embodied energy. In this research, three different types of plastic fibers were used. Then, the blends were evaluated by considering their mechanical properties, including compressive strength and tensile strength. In addition, the non-destructive ultrasonic wave velocity was measured. The result shows excellent potential for the use of plastic fibers in rammed earth, especially in terms of compressive strength.

Keywords: mechanical characterization, plastic fibers reinforcement, rammed earth, sustainable material

Procedia PDF Downloads 47
1174 Adsorptive Performance of Surface Modified Montmorillonite in Vanadium Removal from Real Mine Water

Authors: Opeyemi Atiba-Oyewo, Taile Y. Leswfi, Maurice S. Onyango, Christian Wolkersdorfer

Abstract:

This paper describes the preparation of surface modified montmorillonite using hexadecyltrimethylammonium bromide (HDTMA-Br) for the removal of vanadium from mine water. The adsorbent before and after adsorption was characterised by Fourier transform infra-red (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM), while the amount of vanadium adsorbed was determined by ICP-OES. The batch adsorption method was employed using vanadium concentrations in solution ranging from 50 to 320 mg/L and vanadium tailings seepage water from a South African mine. Also, solution pH, temperature and sorbent mass were varied. Results show that the adsorption capacity was affected by solution pH, temperature, sorbent mass and the initial concentration. Electrical conductivity of the mine water before and after adsorption was measured to estimate the total dissolved solids in the mine water. Equilibrium isotherm results revealed that vanadium sorption follows the Freundlich isotherm, indicating that the surface of the sorbent was heterogeneous. The pseudo-second order kinetic model gave the best fit to the kinetic experimental data compared to the first order and Elovich models. The results of this study may be used to predict the uptake efficiency of South Africa montmorillonite in view of its application for the removal of vanadium from mine water. However, the choice of this adsorbent for the uptake of vanadium or other contaminants will depend on the composition of the effluent to be treated.

Keywords: adsorption, vanadium, modified montmorillonite, equilibrium, kinetics, mine water

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1173 Concanavaline a Conjugated Bacterial Polyester Based PHBHHx Nanoparticles Loaded with Curcumin for the Ovarian Cancer Therapy

Authors: E. Kilicay, Z. Karahaliloglu, B. Hazer, E. B. Denkbas

Abstract:

In this study, we have prepared concanavaline A (ConA) functionalized curcumin (CUR) loaded PHBHHx (poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)) nanoparticles as a novel and efficient drug delivery system. CUR is a promising anticancer agent for various cancer types. The aim of this study was to evaluate therapeutic potential of curcumin loaded PHBHHx nanoparticles (CUR-NPs) and concanavaline A conjugated curcumin loaded NPs (ConA-CUR NPs) for ovarian cancer treatment. ConA was covalently connected to the carboxylic group of nanoparticles by EDC/NHS activation method. In the ligand attachment experiment, the binding capacity of ConA on the surface of NPs was found about 90%. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) analysis showed that the prepared nanoparticles were smooth and spherical in shape. The size and zeta potential of prepared NPs were about 228±5 nm and −21.3 mV respectively. ConA-CUR NPs were characterized by FT-IR spectroscopy which confirmed the existence of CUR and ConA in the nanoparticles. The entrapment and loading efficiencies of different polymer/drug weight ratios, 1/0.125 PHBHHx/CUR= 1.25CUR-NPs; 1/0.25 PHBHHx/CUR= 2.5CUR-NPs; 1/0.5 PHBHHx/CUR= 5CUR-NPs, ConA-1.25CUR NPs, ConA-2.5CUR NPs and ConA-5CUR NPs were found to be ≈ 68%-16.8%; 55%-17.7 %; 45%-33.6%; 70%-15.7%; 60%-17%; 51%-30.2% respectively. In vitro drug release showed that the sustained release of curcumin was observed from CUR-NPs and ConA-CUR NPs over a period of 19 days. After binding of ConA, the release rate was slightly increased due to the migration of curcumin to the surface of the nanoparticles and the matrix integrities was decreased because of the conjugation reaction. This functionalized nanoparticles demonstrated high drug loading capacity, sustained drug release profile, and high and long term anticancer efficacy in human cancer cell lines. Anticancer activity of ConA-CUR NPs was proved by MTT assay and reconfirmed by apoptosis and necrosis assay. The anticancer activity of ConA-CUR NPs was measured in ovarian cancer cells (SKOV-3) and the results revealed that the ConA-CUR NPs had better tumor cells decline activity than free curcumin. The nacked nanoparticles have no cytotoxicity against human ovarian carcinoma cells. Thus the developed functionalized nanoformulation could be a promising candidate in cancer therapy.

Keywords: curcumin, curcumin-PHBHHx nanoparticles, concanavalin A, concanavalin A-curcumin PHBHHx nanoparticles, PHBHHx nanoparticles, ovarian cancer cell

Procedia PDF Downloads 380
1172 Changes to Populations Might Aid the Spread Antibiotic Resistance in the Environment

Authors: Yasir Bashawri, Vincent N. Chigor James McDonald, Merfyn Williams, Davey Jones, A. Prysor Williams

Abstract:

Resistance to antibiotics has become a threat to public health. As a result of their misuse and overuse, bacteria have become resistant to many common antibiotics. Βeta lactam (β-lactam) antibiotics are one of the most significant classes of antimicrobials in providing therapeutic benefits for the treatment of bacterial infections in both human and veterinary medicine, for approximately 60% of all antibiotics are used. In particular, some Enterobacteriaceae produce Extend Spectrum Beta Lactamases (ESBLs) that enable them to some break down multi-groups of antibiotics. CTX-M enzymes have rapidly become the most important ESBLs, with increases in mainly CTX-M 15 in many countries during the last decade. Global travel by intercontinental medical ‘tourists’, migrant employees and overseas students could theoretically be a risk factor for spreading antibiotic resistance genes in different parts of the world. Bangor city, North Wales, is subject to sudden demographic changes due to a large proportion (>25%) of the population being students, most of which arrive over a space of days. This makes it a suitable location to study the impacts of large demographic change on the presence of ESBLs. The aim of this study is to monitor the presence of ESBLs in Escherichia coli and faecal coliform bacteria isolated from Bangor wastewater treatment plant, before, during and after the arrival week of students to Bangor University. Over a five-week period, water samples were collected twice a week, from the influent, primary sedimentation tank, aeration tank and the final effluent. Isolation and counts for Escherichia coli and other faecal coliforms were done on selective agar (primary UTI agar). ESBL presence will be confirmed by phenotypic and genotypic methods. Sampling at all points of the tertiary treatment stages will indicate the effectiveness of wastewater treatment in reducing the spread of ESBLs genes. The study will yield valuable information to help tackle a problem which many regard to be the one of the biggest threats to modern-day society.

Keywords: extended spectrum β-lactamase, enterobacteriaceae, international travel, wastewater treatment plant

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1171 Characterization of a Broad Range Antimicrobial Substance from Pseudozyma aphidis

Authors: Raviv Harris, Maggie Levy

Abstract:

Natural product-based pesticides may serve as an alternative to the traditional synthetic pesticides, which have a potentially damaging effect, both to human health and for the environment. Along with plants, microorganisms are a prospective source of such biological pesticides. A unique and active strain of P. aphidis (designated isolate L12, Israel 2004), an epiphytic and non-pathogenic basidiomycete yeast, was isolated in our lab from strawberry leaves. P. aphidis L12 secretions were found to inhibit broad range of plant pathogens. This work demonstrates that metabolites isolated from the biocontrol agent P. aphidis (isolate L12) can inhibit varied fungal and bacterial phytopathogens. Biologically active metabolites were extracted from P. aphidis biomass, using the organic solvent ethyl acetate. The antimicrobial activity of the extract was demonstrated, both in vitro and in planta. Using disk diffusion assays, the following inhibition zones were obtained: 43cm² for Pseudomonas syringae pv. tomato, 28.5cm² for Xanthomonas campestris pv. vesicatoria, 59cm² for Clavibacter michiganensis subsp. michiganensis, 34cm² for Erwinia amylovora and 34cm² for Agrobacterium tumefaciens. Additionally, strong inhibitory activity of the extract against fungi mycelial growth was established, with IC₅₀ values of 606µg ml⁻¹ for Botrytis cinerea, 221µg ml⁻¹ for Pythium spp., 519µg ml⁻¹ for Rhizoctonia solani, 455µg ml⁻¹ for Sclerotinia sclerotiorum, 2270µg ml⁻¹ for Fusarium oxysporum f. sp. lycopersici, and 2038µg ml⁻¹ for Alternaria alternata. The results of the in planta experiments demonstrated a dose-dependent reduction in disease infection. Significant inhibition of B. cinerea lesions on tomato plants was obtained when a spore suspension of this pathogen was treated with extract concentrations higher than 4.2mg ml⁻¹. Concentration of 7mg ml⁻¹ caused a reduction of over 95% in the lesion size of B. cinerea on tomato plants. The strong antimicrobial activity demonstrated both in vitro and in planta against varied phytopathogens, may indicate that the extracted antimicrobial metabolites have potential to serve as natural pesticides in the field.

Keywords: antimicrobial, B. cinerea, metabolites, natural pesticides, P. aphidis

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1170 Effect of BaO-Bi₂O₃-P₂O₅ Glass Additive on Structural and Dielectric Properties of BaTiO₃ Ceramics

Authors: El Mehdi Haily, Lahcen Bih, Mohammed Azrour, Bouchaib Manoun

Abstract:

The effects of xBi₂O₃-yBaO-zP₂O₅ (BBP) glass addition on the sintering, structural, and dielectric properties of BaTiO₃ ceramic (BT) are studied. The BT ceramic was synthesized by the conventional solid-state reaction method while the glasses BaO-Bi₂O₃-P₂O₅ (BBP) were elaborated by melting and quenching process. Different composites BT-xBBP were formed by mixing the BBP glasses with BT ceramic. For each glass composition, where the ratio (x:y:z) is maintained constant, we have developed three composites with different glass weight percentage (x = 2.5, 5, and 7.5 wt %). Addition of the glass helps in better sintering at lower temperatures with the presence of liquid phase at the respective sintering temperatures. The results showed that the sintering temperature decreased from more than 1300°C to 900°C. Density measurements of the composites are performed using the standard Archimedean method with water as medium liquid. It is found that their density and molar volume decrease and increase with glass content, respectively. Raman spectroscopy is used to characterize their structural approach. This technique has allowed the identification of different structural units of phosphate and the characteristic vibration modes of the BT. The electrical properties of the composite samples are carried out by impedance spectroscopy in the frequency range of 10 Hz to 1 MHz under various temperatures from 300 to 473 K. The obtained results show that their dielectric properties depend both on the content of the glass in the composite and the Bi/P ratio in the glasses.

Keywords: phosphate, glasses, composite, Raman spectroscopy, dielectric properties

Procedia PDF Downloads 142
1169 Micro-Arc Oxidation Titanium and Post Treatment by Cold Plasma and Graft Polymerization of Acrylic Acid for Biomedical Application

Authors: Shu-Chuan Liao, Chia-Ti Chang, Ko-Shao Chen

Abstract:

Titanium and its alloy are widely used in many fields such as dentistry or orthopaedics. Due to their high strength low elastic modulus that chemical inertness and bio inert. The micro-arc oxidation used to formation a micro porous ceramic oxide layer film on Titanium surface and also to improve the resistance corrosion. For improving the biocompatibility, micro-arc oxidation surfaces bio-inert need to introduce reactive group. We introduced boundary layer by used plasma enhanced chemical vapor deposition of hexamethyldisilazane (HMDS) and organic active layer by UV light graft reactive monomer acrylic acid (AAc) therefore we can immobilize Chondroitin sulphate on surface easily by crosslinking EDC/NHS. The surface properties and composition of the modified layer were measured by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) and water contact angle. Water contact angle of the plasma-treated Ti surface decreases from 60° to 38°, which is an indication of hydrophilicity. The results of electrochemical polarization analysis showed that the sample plasma treated at micro-arc oxidation after plasma treatment has the best corrosion resistance. The result showed that we can immobilize chondroitin sulfate successful by a series of modification and MTT assay indicated the biocompatibility has been improved in this study.

Keywords: MAO, plasma, graft polymerization, biomedical application

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1168 Effect of Reynolds Number on Wall-normal Turbulence Intensity in a Smooth and Rough Open Channel Using both Outer and Inner Scaling

Authors: Md Abdullah Al Faruque, Ram Balachandar

Abstract:

Sudden change of bed condition is frequent in open channel flow. Change of bed condition affects the turbulence characteristics in both streamwise and wall-normal direction. Understanding the turbulence intensity in open channel flow is of vital importance to the modeling of sediment transport and resuspension, bed formation, entrainment, and the exchange of energy and momentum. A comprehensive study was carried out to understand the extent of the effect of Reynolds number and bed roughness on different turbulence characteristics in an open channel flow. Four different bed conditions (impervious smooth bed, impervious continuous rough bed, pervious rough sand bed, and impervious distributed roughness) and two different Reynolds numbers were adopted for this cause. The effect of bed roughness on different turbulence characteristics is seen to be prevalent for most of the flow depth. Effect of Reynolds number on different turbulence characteristics is also evident for flow over different bed, but the extent varies on bed condition. Although the same sand grain is used to create the different rough bed conditions, the difference in turbulence characteristics is an indication that specific geometry of the roughness has an influence on turbulence characteristics. Roughness increases the contribution of the extreme turbulent events which produces very large instantaneous Reynolds shear stress and can potentially influence the sediment transport, resuspension of pollutant from bed and alter the nutrient composition, which eventually affect the sustainability of benthic organisms.

Keywords: open channel flow, Reynolds Number, roughness, turbulence

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1167 Survival of Micro-Encapsulated Probiotic Lactic Acid Bacteria in Mutton Nuggets and Their Assessments in Simulated Gastro-Intestinal Conditions

Authors: Rehana Akhter, Sajad A. Rather, F. A. Masoodi, Adil Gani, S. M. Wani

Abstract:

During recent years probiotic food products receive market interest as health-promoting, functional foods, which are believed to contribute health benefits. In order to deliver the health benefits by probiotic bacteria, it has been recommended that they must be present at a minimum level of 106 CFU/g to 107 CFU/g at point of delivery or be eaten in sufficient amounts to yield a daily intake of 108 CFU. However a major challenge in relation to the application of probiotic cultures in food matrix is the maintenance of viability during processing which might lead to important losses in viability as probiotic cultures are very often thermally labile and sensitive to acidity, oxygen or other food constituents for example, salts. In this study Lactobacillus plantarum and Lactobacillus casei were encapsulated in calcium alginate beads with the objective of enhancing their survivability and preventing exposure to the adverse conditions of the gastrointestinal tract and where then inoculated in mutton nuggets. Micro encapsulated Lactobacillus plantarum and Lactobacillus casei were resistant to simulated gastric conditions (pH 2, 2h) and bile solution (3%, 2 h) resulting in significantly (p ≤ 0.05) improved survivability when compared with free cell counterparts. A high encapsulation yield was found due to the encapsulation procedure. After incubation at low pH-values, micro encapsulation yielded higher survival rates compared to non-encapsulated probiotic cells. The viable cell numbers of encapsulated Lactobacillus plantarum and Lactobacillus casei were 107-108 CFU/g higher compared to free cells after 90 min incubation at pH 2.5. The viable encapsulated cells were inoculated into mutton nuggets at the rate of 108 to 1010 CFU/g. The micro encapsulated Lactobacillus plantarum and Lactobacillus casei achieved higher survival counts (105-107 CFU/g) than the free cell counterparts (102-104 CFU/g). Thus micro encapsulation offers an effective means of delivery of viable probiotic bacterial cells to the colon and maintaining their survival during simulated gastric, intestinal juice and processing conditions during nugget preparation.

Keywords: survival, Lactobacillus plantarum, Lactobacillus casei, micro-encapsulation, nugget

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1166 Design and Fabrication of ZSO Nanocomposite Thin Film Based NO2 Gas Sensor

Authors: Bal Chandra Yadav, Rakesh K. Sonker, Anjali Sharma, Punit Tyagi, Vinay Gupta, Monika Tomar

Abstract:

In the present study, ZnO doped SnO2 thin films of various compositions were deposited on the surface of a corning substrate by dropping the two sols containing the precursors for composite (ZSO) with subsequent heat treatment. The sensor materials used for selective detection of nitrogen dioxide (NO2) were designed from the correlation between the sensor composition and gas response. The available NO2 sensors are operative at very high temperature (150-800 °C) with low sensing response (2-100) even in higher concentrations. Efforts are continuing towards the development of NO2 gas sensor aiming with an enhanced response along with a reduction in operating temperature by incorporating some catalysts or dopants. Thus in this work, a novel sensor structure based on ZSO nanocomposite has been fabricated using chemical route for the detection of NO2 gas. The structural, surface morphological and optical properties of prepared films have been studied by using X-ray diffraction (XRD), Atomic force microscopy (AFM), Transmission electron microscope (TEM) and UV-visible spectroscopy respectively. The effect of thickness variation from 230 nm to 644 nm of ZSO composite thin film has been studied and the ZSO thin film of thickness ~ 460 nm was found to exhibit the maximum gas sensing response ~ 2.1×103 towards 20 ppm NO2 gas at an operating temperature of 90 °C. The average response and recovery times of the sensor were observed to be 3.51 and 6.91 min respectively. Selectivity of the sensor was checked with the cross-exposure of vapour CO, acetone, IPA, CH4, NH3 and CO2 gases. It was found that besides the higher sensing response towards NO2 gas, the prepared ZSO thin film was also highly selective towards NO2 gas.

Keywords: ZSO nanocomposite thin film, ZnO tetrapod structure, NO2 gas sensor, sol-gel method

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1165 Malachite Ore Treatment with Typical Ammonium Salts and Its Mechanism to Promote the Flotation Performance

Authors: Ayman M. Ibrahim, Jinpeng Cai, Peilun Shen, Dianwen Liu

Abstract:

The difference in promoting sulfurization between different ammonium salts and its anion's effect on the sulfurization of the malachite surface was systematically studied. Therefore, this study takes malachite, a typical copper oxide mineral, as the research object, field emission scanning electron microscopy and energy-dispersive X-ray analysis (FESEM‒EDS), X-ray photoelectron spectroscopy (XPS), and other analytical and testing methods, as well as pure mineral flotation experiments, were carried out to examine the superiority of the ammonium salts as the sulfurizing reagent of malachite at the microscopic level. Additionally, the promoting effects of ammonium sulfate and ammonium phosphate on the malachite sulfurization of xanthate-flotation were compared systematically from the microstructure of sulfurized products, elemental composition, chemical state of characteristic elements, and hydrophobicity surface evolution. The FESEM and AFM results presented that after being pre-treated with ammonium salts, the adhesion of sulfurized products formed on the mineral surface was denser; thus, the flake radial dimension product was significantly greater. For malachite sulfurization flotation, the impact of ammonium phosphate in promoting sulfurization is weaker than ammonium sulfate. The reason may be that hydrolyzing phosphate consumes a substantial quantity of H+ in the solution, which hastens the formation of the copper-sulfur products, decreasing the adhesion stability of copper-sulfur species on the malachite surface.

Keywords: sulfurization flotation, adsorption characteristics, malachite, hydrophobicity

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1164 Identification and Characterization of Polysaccharide Biosynthesis Protein (CAPD) of Enterococcus faecium

Authors: Liaqat Ali, Hubert E. Blum, Türkân Sakinc

Abstract:

Enterococcus faecium is an emerging multidrug-resistant nosocomial pathogen increased dramatically worldwide and causing bacteremia, endocarditis, urinary tract and surgical site infections in immunocomprised patients. The capsular polysaccharides that contribute to pathogenesis through evasion of the host innate immune system are also involved in hindering leukocyte killing of enterococci. The gene cluster (enterococcal polysaccharide antigen) of E. faecalis encoding homologues of many genes involved in polysaccharide biosynthesis. We identified two putative loci with 22 kb and 19 kb which contained 11 genes encoding for glycosyltransferases (GTFs); this was confirmed by using genome comparison of already sequenced strains that has no homology to known capsule genes and the epa-locus. The polysaccharide-conjugate vaccines have rapidly emerged as a suitable strategy to combat different pathogenic bacteria, therefore, we investigated a polysaccharide biosynthesis CapD protein in E. faecium contains 336 amino acids and had putative function for N-linked glycosylation. The deletion/knock-out capD mutant was constructed and complemented by homologues recombination method and confirmed by using PCR and sequencing. For further characterization and functional analysis, in-vitro cell culture and in-vivo a mouse infection models were used. Our ΔcapD mutant shows a strong hydrophobicity and all strains exhibited biofilm production. Subsequently, the opsonic activity was tested in an opsonophagocytic assay which shows increased in mutant compared complemented and wild type strains but more than two fold decreased in colonization and adherence was seen on surface of uroepithelial cells. However, a significant higher bacterial colonialization was observed in capD mutant during animal bacteremia infection. Unlike other polysaccharides biosynthesis proteins, CapD does not seems to be a major virulence factor in enterococci but further experiments and attention is needed to clarify its function, exact mechanism and involvement in pathogenesis of enteroccocal nosocomial infections eventually to develop a vaccine/ or targeted therapy.

Keywords: E. faecium, pathogenesis, polysaccharides, biofilm formation

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1163 Evaluation of Antimicrobial Susceptibility Profile of Urinary Tract Infections in Massoud Medical Laboratory: 2018-2021

Authors: Ali Ghorbanipour

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The aim of this study is to investigate the drug resistance pattern and the value of the MIC (minimum inhibitory concentration)method to reduce the impact of infectious diseases and the slow development of resistance. Method: The study was conducted on clinical specimens collected between 2018 to 2021. identification of isolates and antibiotic susceptibility testing were performed using conventional biochemical tests. Antibiotic resistance was determined using kibry-Bauer disk diffusion and MIC by E-test methods comparative with microdilution plate elisa method. Results were interpreted according to CLSI. Results: Out of 249600 different clinical specimens, 18720 different pathogenic bacteria by overall detection ratio 7.7% were detected. Among pathogen bacterial were Gram negative bacteria (70%,n=13000) and Gram positive bacteria(30%,n=5720).Medically relevant gram-negative bacteria include a multitude of species such as E.coli , Klebsiella .spp , Pseudomonas .aeroginosa , Acinetobacter .spp , Enterobacterspp ,and gram positive bacteria Staphylococcus.spp , Enterococcus .spp , Streptococcus .spp was isolated . Conclusion: Our results highlighted that the resistance ratio among Gram Negative bacteria and Gram positive bacteria with different infection is high it suggest constant screening and follow-up programs for the detection of antibiotic resistance and the value of MIC drug susceptibility reporting that provide a new way to the usage of resistant antibiotic in combination with other antibiotics or accurate weight of antibiotics that inhibit or kill bacteria. Evaluation of wrong medication in the expansion of resistance and side effects of over usage antibiotics are goals. Ali ghorbanipour presently working as a supervision at the microbiology department of Massoud medical laboratory. Iran. Earlier, he worked as head department of pulmonary infection in firoozgarhospital, Iran. He received master degree in 2012 from Fergusson College. His research prime objective is a biologic wound dressing .to his credit, he has Published10 articles in various international congresses by presenting posters.

Keywords: antimicrobial profile, MIC & MBC Method, microplate antimicrobial assay, E-test

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1162 Analyzing of the Urban Landscape Configurations and Expansion of Dire Dawa City, Ethiopia Using Satellite Data and Landscape Metrics Approaches

Authors: Berhanu Keno Terfa

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To realize the consequences of urbanization, accurate, and up-to-date representation of the urban landscape patterns is critical for urban planners and policymakers. Thus, the study quantitatively characterized the spatiotemporal composition and configuration of the urban landscape and urban expansion process in Dire Dawa City, Ethiopia, form the year 2006 to 2018. The integrated approaches of various sensors satellite data, Spot (2006) and Sentinel 2 (2018) combined with landscape metrics analysis was employed to explore the pattern, process, and overall growth status in the city. The result showed that the built-up area had increased by 62% between 2006 and 2018, at an average annual increment of 3.6%, while the other land covers were lost significantly due to urban expansion. The highest urban expansion has occurred in the northwest direction, whereas the most fragmented landscape pattern was recorded in the west direction. Overall, the analysis showed that Dire Dawa City experienced accelerated urban expansion with a fragmented and complicated spatiotemporal urban landscape patterns, suggesting a strong tendency towards sprawl over the past 12 years. The findings in the study could help planners and policy developers to insight the historical dynamics of the urban region for sustainable development.

Keywords: zonal metrics, multi-temporal, multi-resolution, urban growth, remote sensing data

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1161 Evaluation of Video Development about Exclusive Breastfeeding as a Nutrition Education Media for Posyandu Cadre

Authors: Ari Istiany, Guspri Devi Artanti, M. Si

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Based on the results Riskesdas, it is known that breastfeeding awareness about the importance of exclusive breastfeeding is still low at only 15.3 %. These conditions resulted in a very infant at risk for infectious diseases, such as diarrhea and acute respiratory infection. Therefore, the aim of this study to evaluate the video development about exclusive breastfeeding as a nutrition education media for posyandu cadre. This research used development methods for making the video about exclusive breastfeeding. The study was conducted in urban areas Rawamangun, East Jakarta. Respondents of this study were 1 media experts from the Department of Educational Technology - UNJ, 2 subject matter experts from Department of Home Economics - UNJ and 20 posyandu cadres to assess the quality of the video. Aspects assessed include the legibility of text, image display quality, color composition, clarity of sound, music appropriateness, duration, suitability of the material and language. Data were analyzed descriptively likes frequency distribution table, the average value, and deviation standard. The result of this study showed that the average score assessment according to media experts, subject matter experts, and posyandu cadres respectively was 3.43 ± 0.51 (good), 4.37 ± 0.52 (very good) and 3.6 ± 0.73 (good). The conclusion is on exclusive breastfeeding video as feasible as a media for nutrition education. While suggestions for the improvement of visual media is multiply illustrations, add material about the correct way of breastfeeding and healthy baby pictures.

Keywords: exclusive breastfeeding, posyandu cadre, video, nutrition education

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1160 Ethnopharmacological Analysis of Fermented Herbal Concoctions

Authors: Ishmael Ntlhamu

Abstract:

In Limpopo Province, the use of herbal concoctions is becoming very popular. These concoctions are claimed to be capable of treating ulcers, diabetes, certain STDs, blood cleansing, and many more types of diseases. The aim of this study was to evaluate the phytochemical composition, evaluate the pharmacological effects and consumption safety in herbal concoctions to treat various kinds of ailments in Limpopo. The concoctions were extracted with 80% acetone. Microorganisms in the concoctions were identified using the Vitek 2 compact system. Qualitative phytochemical analysis was determined using standard chemical tests and thin layer chromatography (TLC). Total polyphenol content was quantified. Antioxidant activity was quantified using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay and ferric reducing power. Antimicrobial activities were determined using a broth micro-dilution assay and bioautography. Cell viability assay was used to determine the cytotoxicity. Results showed that concoctions had antioxidant activity. Presence of different phytoconstituents was observed. Isolated microorganisms were identified as Burkholderia pseudomallei, Staphylococcus vitulimus, Enterococcus columbae, Kocuria kristanae, Staphylococcus intermedius, Cryptococcus laurenti. and Burkholderia pseudomallei (highly pathogenic). Therefore, phytochemicals prove that the concoctions can heal as the antimicrobial tests also displayed activity. Moreover, the concoctions did not exhibit cytotoxic effects. However, contaminants raise concerns, not only for consumer safety but also the quality of herbal concoctions available as part of the traditional medicinal practice in Limpopo.

Keywords: antimicrobials, concoctions, cytotoxicity, phytochemicals

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1159 Use of Polymeric Materials in the Architectural Preservation

Authors: F. Z. Benabid, F. Zouai, A. Douibi, D. Benachour

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These Fluorinated polymers and polyacrylics have known a wide use in the field of historical monuments. PVDF provides a great easiness to processing, a good UV resistance and good chemical inertia. Although the quality of physical characteristics of the PMMA and its low price with a respect to PVDF, its deterioration against UV radiations limits its use as protector agent for the stones. On the other hand, PVDF/PMMA blend is a compromise of a great development in the field of architectural restoration, since it is the best method in term of quality and price to make new polymeric materials having enhanced properties. Films of different compositions based on the two polymers within an adequate solvent (DMF) were obtained to perform an exposition to artificial ageing and to the salted fog, a spectroscopic analysis (FTIR and UV) and optical analysis (refractive index). Based on its great interest in the field of building, a variety of standard tests has been elaborated for the first time at the central laboratory of ENAP (Souk-Ahras) in order to evaluate our blend performance. The obtained results have allowed observing the behavior of the different compositions of the blend under various tests. The addition of PVDF to PMMA enhances the properties of this last to know the exhibition to the natural and artificial ageing and to the saline fog. On the other hand, PMMA enhances the optical properties of the blend. Finally, 70/30 composition of the blend is in concordance with results of previous works and it is the adequate proportion for an eventual application.

Keywords: blend, PVDF, PMMA, preservation, historic monuments

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1158 Sialic Acid Profile and Sialidase Activity in HIV-Infected Individuals

Authors: Hadiza Abdullahi

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Sialic Acids and sialidases have been implicated in many disease states particularly bacterial and viral infections which are common opportunist infections of HIV disease. Their role in HIV/AIDS is contemplated. A study was carried out to determine Sialic Acid profile and Sialidase Activity in HIV infected and Apparently Healthy individuals, and also determine the relationship between the sialic acid levels and sialidase activity. Blood samples were collected from 200 subjects (150 HIV infected individuals and 50 apparently healthy individuals divided into four groups- HIV ART Naïve, HIV Stable (on ART but have been stable with no clinical episodes), HIV-OI (on ART with opportunistic infections), and Apparently Healthy). Complete Blood Count, Erythrocyte Surface Sialic Acid (ESSA), Free Serum Sialic Acid (FSSA) concentrations and Sialidase activity were determined for all 200 subjects. Analysis of variance (ANOVA) was used to compare the results of the different groups of HIV infected individuals as well as controls. The mean haemoglobin (HGB), Packed Cell Volume (PCV) and Red Blood Cells (RBC) concentrations were significantly lower (P ≤ 0.05) in the HIV groups compared with the apparently healthy groups. Anaemia and neutropaenia were the most common heamatological abnormalities observed in this study with highest prevalence of anaemia found in the ART naive group. The mean FSSA was 0.4±0.4mg/ml. There was a significant difference (p ≤ 0.05) between some groups. The highest levels of FSSA was observed in the HIV ART naïve (0.65±0.5mg/ml). The mean ESSA value for the study population was 0.54±0.35mg/ml with no significant difference (p ≤ 0.05) between groups. The mean sialidase activity values were 0.52±0.1 µmol/min/µl, 0.40±0.1 µmol/min/µl, 0.45±0.1 µmol/min/µl and 0.41±0.1 µmol/min/µl for the HIV ART naïve, HIV stable, HIV/OIs and apparently healthy groups respectively. No significant difference (p ≤ 0.05) was found between groups and also in gender and age. The finding in this study of higher mean sialidase activity and FSSA levels in the ART naïve HIV group compared with other groups indicate that the virus and other opportunistic pathogens may be sialidase producers in vivo which cleave off sialic acids from erythrocytes surface, leading to high levels of FSSA, anaemia and neutropaenia seen in this group. The higher ESSA concentration found in the HIV stable group along with lowest FSSA concentration in the group suggests the presence of sialyltransferases.

Keywords: erythrocyte surface sialic acid, free serum sialic acid, HIV, sialidase

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1157 Mineralogical and Geochemical Constraints on the Origin and Environment of Numidian Siliceous Sedimentary Rocks of the Extreme Northwest Tunisia

Authors: Ben Yahia Nouha, Harris Chris, Sebei Abdelaziz, Boussen Slim, Chaabani Fredj

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The present work has set itself the objective of studying non-detritic siliceous rocks of the extreme northwest Tunisia. It aims to examine the origin and their sedimentary depositional environment based on mineralogical and geochemical characteristics. The different sections were located in the area of Babouch and the area of Tabarka. The collected samples were subjected to mineralogical and geochemical characterization using different analytical methods: X-ray diffraction (XRD), geochemical analysis (ICP- AES), isotopic geochemistry (δ18O), to assess their suitability for industrial use. X-ray powder diffraction of the pure siliceous rock indicates quartz as the major mineral, with the total lack of amorphous silica. Trace impurities, such as carbonate and clay minerals, are concealed in the analytical results. The petrographic examination revealed allowed us to deduce that this rock was deriving from tests of siliceous organisms (the radiolarians). The chemical composition shows that SiO2, Al2O3, and Fe2O3 represent the most abundant oxides. The other oxides are present in negligible quantities. Geochemical data support a biogenic and non-hydrothermal origin of babouchite silica. Oxygen isotopic has shown that babouchites were formed in an environment with a high temperature ranging from 56 °C to 73 °C.

Keywords: biogenic silica, babouchite formation, XRD, chemical analysis, oxygen isotopic, northwest tunisia

Procedia PDF Downloads 134