Search results for: zinc dioxide

Authors: E. Riani, T. T. Irawadi, S. Nurjanah, K. Syamsu, E. G. Said, Suprihatin, M. R. Cordova

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Especially coastal, Indonesian and Chinese communities have utilized sandfish to improve reproduction quality of men. This study aimed to examine the nutrition on sandfish flesh that has the potency to improve reproduction quality of men. The materials used were sandfish with weight of 200-500 g, and then analysis of proximate, analysis of amino acid, analysis of fatty acid and analysis of mineral contained in the sandfish were performed. The results showed that protein content (39.96%) was the main component of the flesh; the carbohydrate and fat were 25.43% and 4.18%, respectively. Sandfish powder contains several essential amino acids and nonessential amino acids. Nine of ten amino acids needed by human body are contained in sandfish powder, i.e. arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, tryptophan, threonine and valine; only tryptophan that are not contained in sandfish powder. Sandfish powder contains saturated fatty acid kaproat, kaprilat, kaprat, laurat, miristat, stearat, arakhidat and behenat; monosaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA). MUFA is composed of fatty acid oleat, while PUFA is composed fatty acid omega 3 (linonenat, eicosapentaenoic acid and docosahexaenoic acid) and omega 6 (linoleat and arakhidonat). The minerals contained in sandfish powder are macrominerals and microminerals. Based on the findings, the nutrition in sandfish powder has a good potency to improve reproduction of men, especially PUFA for the maturation of spermatozoa, zinc for production function and spermatogenesis, motility of spermatozoa, acromoson reaction; Mg for transformation of genetic information and motility of spermatozoa; calcium for spermatogenesis, capacity and fertilization of spermatozoa. Thus, sandfish flesh powder has the potency to improve reproduction quality of men.

Keywords: sandfish flesh powder, nutrition, reproduction quality, men

Procedia PDF Downloads 427

Authors: Anoff Anim, Lila A. M. Mahmoud, Maria Katsikogianni, Sanjit Nayak

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Sustained and controlled delivery of antimicrobial drugs have been largely studied recently using metal organic frameworks (MOFs)and different polymers. However, much attention has not been given to combining both MOFs and biodegradable polymers, which would be a good strategy in providing a sustained gradual release of the drugs. Herein, we report a comparative study of the sustained and controlled release of widely used antibacterial drugs, cephalexin and metronidazole, from zinc-based MOF-5 incorporated in biodegradable polycaprolactone (PCL) and poly-lactic glycolic acid (PLGA) membranes. Cephalexin and metronidazole were separately incorporated in MOF-5 post-synthetically, followed by their integration into biodegradable PLGA and PCL membranes. The pristine MOF-5 and the loaded MOFs were thoroughly characterized by FT-IR, SEM, TGA and PXRD. Drug release studies were carried out to assess the release rate of the drugs in PBS and distilled water for up to 48 hours using UV-Vis Spectroscopy. Four bacterial strains from both the Gram-positive and Gram-negative types, Staphylococus aureus, Staphylococuss epidermidis, Escherichia coli, Acinetobacter baumanii, were tested against the pristine MOF, pure drugs, loaded MOFs and the drug-loaded MOF-polymer composites. Metronidazole-loaded MOF-5 composite of PLGA (PLGA-Met@MOF-5) was found to show highest efficiency to inhibit the growth of S. epidermidis compared to the other bacteria strains while maintaining a sustained minimum inhibitory concentration (MIC). This study demonstrates that the combination of biodegradable MOF-polymer composites can provide an efficient platform for sustained and controlled release of antimicrobial drugs and can be a potential strategy to integrate them in biomedical devices.

Keywords: antimicrobial resistance, biodegradable polymers, cephalexin, drug release metronidazole, MOF-5, PCL, PLGA

Procedia PDF Downloads 105

Authors: Houria Rezala, Jose Luis Valverde, Amaya Romero, Alessandra Molinari, Andrea Maldotti

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A pillared montmorillonite containing iron doped titania (Fe/Ti-PILC) has been prepared from a natural clay. This material has been characterized by X-ray diffraction, nitrogen adsorption, temperature programmed desorption of ammonia, inductively coupled plasma atomic emission spectroscopy, atomic absorption, and diffuse reflectance UV-VIS spectroscopy. The layer structure of Fe/Ti-PILC resulted to be ordered with an insertion of pillars, which caused a slight increase in the basal spacing of the clay. Its specific surface area was about three times larger than that of the parent Na-montmorillonite due principally to the creation of a remarkable microporous network. The doped material was a robust photocatalyst able to oxidize liquid alkyl aromatics to the corresponding carbonylic derivatives, using O2 as the oxidizing species, at mild pressure and temperature conditions. Accumulation of valuable carbonylic derivatives was possible since their over-oxidation to carbon dioxide was negligible. Fe/Ti-PILC was able to discriminate between toluene and cyclohexane in favor of the aromatic compound with an efficiency that is about three times higher than that of titanium pillared clays (Ti-PILC). It is likely that the addition of iron favored the formation of new acid sites able to interact with the aromatic substrate. Iron doping caused a significant TiO2 visible light-induced activity (wavelength > 400 nm) with only minor negative effects on its performance under UV-light irradiation (wavelength > 290 nm).

Keywords: alkyl aromatics oxidation, heterogeneous photocatalysis, iron doping, pillared clays

Procedia PDF Downloads 424

Authors: Alaa A. H. Shehada, Eman Abdelnasser Abouhassanein, Reem Mohsen Ali, Joyce J. Moawad, Hiba Bawadi, Abdelhamid Kerkadi

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Background: The association between obesity and micronutrient deficiencies is well documented. Among minerals that have been widely studied: zinc, iron and magnesium. Objectives: This study aims to determine the association between obesity indices and mineral status among Qatari adults. Methods: Secondary data was obtained from Qatar Biobank. 414 healthy Qatari aged 20-50 years old were randomly selected from the database. Anthropometric measurements (WC, Weight, and height), body fat, and mineral status (Fe, Mg, Ca, K, Na) were obtained for all selected participants. Differences in anthropometric measurements and mineral status were analyzed by t-test or ANOVA. Spearman correlation coefficients were determined to assess the association between minerals and anthropometric variables. Statistical significance for the hypothesis tests was set at p <0.05. All statistical analysis was preformed using SPSS software version 23.0. Results: Iron, calcium, and sodium levels decreased with an increase in body mass index. Moreover, only iron showed a significant correlation with waist circumference, and waist to height ratio increased. Additionally, calcium, iron, magnesium, and sodium had a statistically significant negative correlation with total body fat percentage and trunk fat percentage. There were statistically significant negative correlations of anthropometrics with minerals. Conclusion: Body fat and trunk fat percentage had a significant inverse relationship with iron, calcium, sodium, and magnesium, while there was no correlation between body fat or trunk fat percentage with potassium.

Keywords: Qatar biobank, body fat distribution, mineral status, Qatari adults

Procedia PDF Downloads 121

Authors: Jean-Philippe Gagnon, Benjamin Saute, Stéphane Boubanga-Tombet

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Infrared thermal imaging is used for a wide range of applications, especially in the combustion domain. However, it is well known that most combustion gases such as carbon dioxide (CO₂), water vapor (H₂O), and carbon monoxide (CO) selectively absorb/emit infrared radiation at discrete energies, i.e., over a very narrow spectral range. Therefore, temperature profiles of most combustion processes derived from conventional broadband imaging are inaccurate without prior knowledge or assumptions about the spectral emissivity properties of the combustion gases. Using spectral filters allows estimating these critical emissivity parameters in addition to providing selectivity regarding the chemical nature of the combustion gases. However, due to the turbulent nature of most flames, it is crucial that such information be obtained without sacrificing temporal resolution. For this reason, Telops has developed a time-resolved multispectral imaging system which combines a high-performance broadband camera synchronized with a rotating spectral filter wheel. In order to illustrate the benefits of using this system to characterize combustion experiments, measurements were carried out using a Telops MS-IR MW on a very simple combustion system: a wood fire. The temperature profiles calculated using the spectral information from the different channels were compared with corresponding temperature profiles obtained with conventional broadband imaging. The results illustrate the benefits of the Telops MS-IR cameras for the characterization of laminar and turbulent combustion systems at a high temporal resolution.

Keywords: infrared, multispectral, fire, broadband, gas temperature, IR camera

Procedia PDF Downloads 104

Authors: Srikanth Korla, Mahesh Sharnangat

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Composite materials are being widely used in Aerospace, Naval, Defence and other branches of engineering applications. Studies on natural fibers is another emerging research area as they are available in abundance, and also due to their eco-friendly in nature. India being one of the major producer of coir, there is always a scope to study the possibilities of exploring coir as reinforment, and with different combinations of other elements of the composite. In present investigation effort is made to utilize properties possessed by natural fiber and make them enable with polymer/epoxy resin. In natural fiber coconut coir is used as reinforcement fiber in epoxy resin with varying weight percentages of fiber and filler material. Titanium dioxide powder (TiO2) is used as filler material with varying weight percentage including 0%, 2% and 4% are considered for experimentation. Environmental effects on the performance of the composite plate are also studied and presented in this project work; Moisture absorption test for composite specimens is conducted using different solvents including Kerosene, Mineral Water and Saline Water, and its absorption capacity is evaluated. Analysis is carried out in different combinations of Coir as fiber and TiO2 as filler material, and the best suitable composite material considering the strength and environmental effects is identified in this work. Therefore, the significant combination of the composite material is with following composition: 2% TiO2 powder 15% of coir fibre and 83% epoxy, under unique mechanical and environmental conditions considered in the work.

Keywords: composite materials, moisture test, filler material, natural fibre composites

Procedia PDF Downloads 181

Authors: M. A. Mamun, M. I. Khan, M. H. Sarker, K. A. Khan, M. Shajahan

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The study was carried out to investigate on an innovative invention, Pathor Kuchi Leaf (PKL) cell, which is fueled with PKL sap of widely available plant called Bryophyllum pinnatum as an energy source for use in PKL battery to generate electricity. This battery, a primary source of electricity, has several order of magnitude longer shelf-lives than the traditional Galvanic cell battery, is still under investigation. In this regard, we have conducted some experiments using various instruments including Atomic Absorption Spectrophotometer (AAS), Ultra-Violet Visible spectrophotometer (UV-Vis), pH meter, Ampere-Volt-Ohm Meter (AVO Meter), etc. The AAS, UV-Vis, and pH-metric analysis data provided that the potential and current were produced as the Zn electrode itself acts as reductant while Cu2+ and H+ ions are behaving as the oxidant. The significant influence of secondary salt on current and potential leads to the dissociation of weak organic acids in PKL juice, and subsequent enrichment to the reactant ions by the secondary salt effects. However, the liquid junction potential was not as great as minimized with the opposite transference of organic acid anions and H+ ions as their dissimilar ionic mobilities. Moreover, the large value of the equilibrium constant (K) implies the big change in Gibbs free energy (∆G), the more electromotive force works in electron transfer during the forward electrochemical reaction which coincides with the fast reduction of the weight of zinc plate, revealed the additional electrical work in the presence of PKL sap. This easily fabricated high-performance PKL battery can show an excellent promise during the off-peak across the countryside.

Keywords: Atomic Absorption Spectrophotometer (AAS), Bryophylum Pinnatum Leaf (BPL), electricity, electrochemistry, organic acids

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Authors: Cheng Shen, LaiHong Shen

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Ammonia is an important carrier of hydrogen energy, with the characteristics of high hydrogen content density and no carbon dioxide emission. Ammonia synthesis by the Haber process is the main method for industrial ammonia synthesis, but the conversion rate of ammonia per pass is only about 12%, while the conversion rate of biomass synthesis ammonia is as high as 56%. Therefore, safe and efficient ammonia capture for ammonia synthesis from biomass is an important way to alleviate the energy crisis and solve the energy problem. Metal chloride has a chemical adsorption effect on ammonia, and can be desorbed at high temperature to obtain high-concentration ammonia after combining with ammonia, which has a good development prospect in ammonia capture and separation technology. In this paper, the ammonia adsorption properties of CuCl₂ were measured, and the composite adsorbents were prepared by using silicon and multi-walled carbon nanotubes respectively to support CuCl₂, and the ammonia adsorption properties of the composite adsorbents were studied. The study found that the ammonia adsorption capacity of the three adsorbents decreased with the increase in temperature, so metal chlorides were more suitable for the low-temperature adsorption of ammonia. Silicon and multi-walled carbon nanotubes have an enhanced effect on the ammonia adsorption of CuCl₂. The reason is that the porous material itself has a physical adsorption effect on ammonia, and silicon can play the role of skeleton support in cupric chloride particles, which enhances the pore structure of the adsorbent, thereby alleviating sintering.

Keywords: ammonia, adsorption properties, metal chloride, silicon, MWCNTs

Procedia PDF Downloads 74

Authors: Dararat Tongdee, Surapong Chirarattananon, Somchai Maneewan, Chantana Punlek

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Recently, the Internet of Things (IoT) is the important technology that connects devices to the network and people can access real-time communication. This technology is used to report, collect, and analyze the big data for achieving a purpose. For a smart building, there are many IoT technologies that enable management and building operators to improve occupant thermal comfort, indoor air quality, and building energy efficiency. In this research, we propose monitoring and controlling performance of a smart dedicated outdoor air system (SDOAS) based on IoT platform. The SDOAS was specifically designed with the desiccant unit and thermoelectric module. The designed system was intended to monitor, notify, and control indoor environmental factors such as temperature, humidity, and carbon dioxide (CO₂) level. The SDOAS was tested under the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE 62.2) and indoor air quality standard. The system will notify the user by Blynk notification when the status of the building is uncomfortable or tolerable limits are reached according to the conditions that were set. The user can then control the system via a Blynk application on a smartphone. The experimental result indicates that the temperature and humidity of indoor fresh air in the comfort zone are approximately 26 degree Celsius and 58% respectively. Furthermore, the CO₂ level was controlled lower than 1000 ppm by indoor air quality standard condition. Therefore, the proposed system can efficiently work and be easy to use for buildings.

Keywords: internet of things, indoor air quality, smart dedicated outdoor air system, thermal comfort

Procedia PDF Downloads 173

Authors: Zong-Xian Qiu, Ta-Wui Cheng, Wei-Hao Lee, Yung-Chin Ding

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The greenhouse effect is an important issue since it has been responsible for global warming. Carbon dioxide plays an important part of role in the greenhouse effect. Therefore, human has the responsibility for reducing CO₂ emissions in their daily operations. Except iron making and power plants, another major CO₂ production industry is cement industry. According to the statistics by EPA of Taiwan, production 1 ton of Portland cement will produce 520.29 kg of CO₂. There are over 7.8 million tons of CO₂ produced annually. Thus, trying to development low CO₂ emission green concrete is an important issue, and it can reduce CO₂ emission problems in Taiwan. The purpose of this study is trying to use marble wastes and slag as the raw materials to fabricate geopolymer green concrete. The result shows the marble based geopolymer green concrete have good workability and the compressive strength after curing for 28 days and 365 days can be reached 44MPa and 53MPa in indoor environment, 28MPa and 40.43MPa in outdoor environment. The acid resistance test shows the geopolymer green concrete have good resistance for chemical attack. The coefficient of permeability of geopolymer green concrete is better than Portland concrete. By comparing with Portland cement products, the marble based geopolymer not only reduce CO₂ emission problems but also provides great performance in practices. According to the experiment results shown that geopolymer concrete has great potential for further engineering development in the future, the new material could be expected to replace the Portland cement products in the future days.

Keywords: marble, slag, geopolymer, green concrete, CO₂ emission

Procedia PDF Downloads 112

Authors: Amit Keshav, Alok Sharma, Bidyut Mazumdar

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Colocasia esculenta leaves and roots are widely used in Asian countries, such as, India, Srilanka and Pakistan, as food and feed material. The root is high in carbohydrates and rich in zinc. The leaves and stalks are often traditionally preserved to be eaten in dry season. Leaf juice is stimulant, expectorant, astringent, appetizer, and otalgia. Looking at the medicinal uses of the plant leaves; phytochemicals were extracted from the plant leaves and were characterized using Fourier-transform infrared spectroscopy (FTIR) to find the functional groups. Phytochemical analysis of Colocasia esculenta (L.) leaf was studied using three solvents (methanol, chloroform, and ethanol) with soxhlet apparatus. Powder of the leaves was employed to obtain the extracts, which was qualitatively and quantitatively analyzed for phytochemical content using standard methods. Phytochemical constituents were abundant in the leave extract. Leaf was found to have various phytochemicals such as alkaloids, glycosides, flavonoids, terpenoids, saponins, oxalates and phenols etc., which could have lot of medicinal benefits such as reducing headache, treatment of congestive heart failure, prevent oxidative cell damage etc. These phytochemicals were identified using UV spectrophotometer and results were presented. In order to find the antioxidant activity of the extract, DPPH (2,2-diphenyl-1-picrylhydrazyl) method was employed using ascorbic acid as standard. DPPH scavenging activity of ascorbic acid was found to be 84%, whereas for ethanol it was observed to be 78.92%, for methanol: 76.46% and for chloroform: 72.46%. Looking at the high antioxidant activity, Colocasia esculenta may be recommended for medicinal applications. The characterizations of functional groups were analyzed using FTIR spectroscopy.

Keywords: antioxidant activity, Colocasia esculenta, leaves, characterization, FTIR

Procedia PDF Downloads 201

Authors: Dernie Taganna Olguera

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Marginal uplands are fragile ecosystems in the tropics that need to be evaluated for sustainable utilization and land degradation mitigation. Thus, this study evaluated the dominant soil degradation processes in selected marginal uplands of Samar Island, Philippines; evaluated the important factors influencing soil degradation in the selected sites and identified the indicators of soil degradation in marginal uplands of the tropical landscape of Samar Island, Philippines. Two (2) sites were selected (Sta. Rita, Samar and Salcedo, Eastern, Samar) representing the western and eastern sides of Samar Island respectively. These marginal uplands represent different agro-climatic zones suitable for the study. Soil erosion is the major soil degradation process in the marginal uplands studied. It resulted in not only considerable soil losses but nutrient losses as well. Soil erosion varied with vegetation cover and site. It was much higher in the sweetpotato, cassava, and gabi crops than under natural vegetation. In addition, soil erosion was higher in Salcedo than in Sta. Rita, which is related to climatic and soil characteristics. Bulk density, porosity, aggregate stability, soil pH, organic matter, and carbon dioxide evolution are good indicators of soil degradation. The dominance of Saccharum spontaneum Linn., Imperata cylindrica Linn, Melastoma malabathricum Linn. and Psidium guajava Linn indicated degraded soil condition. Farmer’s practices particularly clean culture and organic fertilizer application influenced the degree of soil degradation in the marginal uplands of Samar Island, Philippines.

Keywords: soil degradation, soil erosion, marginal uplands, Samar island, Philippines

Procedia PDF Downloads 382

Authors: Özlem Ateş Sönmezoğlu, Begüm Terzi, Ahmet Yıldırım, Leyla Gündüz

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Durum wheat quality is defined as its suitability for pasta processing, that is pasta making quality. Another factor that determines the quality of durum wheat is the nutritional value of wheat or its final products. Wheat is a basic source of calories, proteins and minerals for humans in many countries of the world. For this reason, improvement of wheat nutritional value is of great importance. In recent years, deficiencies in protein and micronutrients, particularly in iron and zinc, have seriously increased. Therefore, basic foods such as wheat must be improved for micronutrient content. The effects of some major genes for grain quality established. Gpc-B1 locus is one of the genes increased protein and micronutrients content, and used in improvement studies of durum wheat nutritional value. The aim of this study was to increase the protein content and the micronutrient (Fe, Zn ve Mn) contents of an advanced durum wheat line (TMB 1) that was previously improved for its protein quality. For this purpose, TMB1 advanced durum wheat line were used as the recurrent parent and also, UC1113-Gpc-B1 line containing the Gpc-B1 gene was used as the gene source. In all of the generations, backcrossed plants carrying the targeted gene region were selected by marker assisted selection (MAS). BC4F1 plants MAS method was employed in combination with embryo culture and rapid plant growth in a controlled greenhouse conditions in order to shorten the duration of the transition between generations in backcross breeding. The Gpc-B1 gene was selected specific molecular markers. Since Yr-36 gene associated with Gpc-B1 allele, it was also transferred to the Gpc-B1 transferred lines. Thus, the backcrossed plants selected by MAS are resistance to yellow rust disease. This research has been financially supported by TÜBİTAK (112T910).

Keywords: Durum wheat, Gpc-B1, MAS, Triticum durum, Yr-36

Procedia PDF Downloads 253

Authors: Alieh Farshbaf

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Introduction: Current anti-retroviral drugs have some restrictions for treatment of HIV-1 infection. The efficacy of retroviral drugs is not same in different infected patients and the virus rebound from latent reservoirs after stopping them. Recently, the engineering of stem cells and gene therapy provide new approaches to eliminate some drug problems by induction of resistance to HIV-1. Literature review: Up to now, AIDS-restriction genes (ARGs) were suitable candidate for gene and cell therapies, such as cc-chemokine receptor-5 (CCR5). In this manner, CCR5 provide effective cure in Berlin and Boston patients by inducing of HIV-1 resistance with allogeneic stem cell transplantation. It is showed that Zinc Finger Nuclease (ZFN) could induce HIV-1 resistance in stem cells of infected patients by homologous recombination or non-end joining mechanism and eliminate virus loading after returning the modified cells. Then, gene modification by HIV restriction factors, as TRIM5, introduced another gene candidate for HIV by interfering in infection process. These gene modifications/editing provided by stem cell futures that improve treatment in refractory disease such as HIV-1. Conclusion: Although stem cell transplantation has some complications, but in compare to retro-viral drugs demonstrated effective cure by elimination of virus loading. On the other hand, gene therapy is cost-effective for an infected patient than retroviral drugs payment in a person life-long. The results of umbilical cord blood stem cell transplantation showed that gene and cell therapy will be applied easier than previous treatment of AIDS with high efficacy.

Keywords: stem cell, AIDS, gene modification, cell engineering

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Authors: Abbas Ahmed Albu Shaqraa

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The concept of a safe environment and low greenhouse gas emissions is a common concern especially in the construction industry. The produced carbon dioxide (CO2) emissions are nearly a ton in producing only one ton of Portland cement, which is the primary ingredient of concrete. Current studies had investigated the utilization of several waste materials in producing a cement free concrete. The geopolymer concrete is a green material that results from the reaction of aluminosilicate material with an alkaline liquid. A summary of several recent researches in geopolymer concrete will be presented in this manuscript. In addition, the offered presented review considers the use of several waste materials including fly ash, granulated blast furnace slag, cement kiln dust, kaolin, metakaolin, and limestone powder as binding materials in making geopolymer concrete. Moreover, the mechanical, chemical and thermal properties of geopolymer concrete will be reviewed. In addition, the geopolymer concrete applications and limitations will be discussed as well. The results showed a high early compressive strength gain in geopolymer concrete when dry- heating or steam curing was performed. Also, it was stated that the outstanding acidic resistance of the geopolymer concrete made it possible to be used where the ordinary Portland cement concrete was doubtable. Thus, the commercial geopolymer concrete pipes were favored for sewer system in case of high acidic conditions. Furthermore, it was reported that the geopolymer concrete could stand up to 1200 °C in fire without losing its strength integrity whereas the Portland cement concrete was losing its function upon heating to some 100s °C only. However, the geopolymer concrete still considered as an emerging field and occupied mainly by the precast industries.

Keywords: geopolymer concrete, Portland cement concrete, alkaline liquid, compressive strength

Procedia PDF Downloads 196

Authors: Nouf Alharbi, James O'shea

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For decades, renewable energy sources have received considerable global interest due to the increase in fossil fuel consumption. The abundant energy produced by sunlight makes dye-sensitised solar cells (DSSCs) a promising alternative compared to conventional silicon and thin film solar cells due to their transparency and tunable colours, which make them suitable for applications such as windows and glass facades. The transfer of an excited electron onto the surface is an important procedure in the DSSC system, so different groups of dye molecules were studied on the rutile TiO2 (110) surface. Currently, the study of organic dyes has become an interest of researchers due to ruthenium being a rare and expensive metal, and metal-free organic dyes have many features, such as high molar extinction coefficients, low manufacturing costs, and ease of structural modification and synthesis. There are, of course, some groups that have developed organic dyes and exhibited lower light-harvesting efficiency ranging between 4% and 8%. Since most dye molecules are complicated or fragile to be deposited by thermal evaporation or sublimation in the ultra-high vacuum (UHV), all dyes (i.e, D5, SC4, and R6) in this study were deposited in situ using the electrospray deposition technique combined with X-ray photoelectron spectroscopy (XPS) as an alternative method to obtain high-quality monolayers of titanium dioxide. These organic molecules adsorbed onto rutile TiO2 (110) are explored by XPS, which can be used to obtain element-specific information on the chemical structure and study bonding and interaction sites on the surface.

Keywords: dyes, deposition, electrospray, molecules, organic, rutile, sensitised, XPS

Procedia PDF Downloads 49

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 52

Authors: Anoff Anim, Lila Mahmound, Maria Katsikogianni, Sanjit Nayak

Abstract:

Sustained and controlled delivery of antimicrobial drugs have been largely studied recently using metal organic frameworks (MOFs)and different polymers. However, much attention has not been given to combining both MOFs and biodegradable polymers which would be a good strategy in providing a sustained gradual release of the drugs. Herein, we report a comparative study of the sustained and controlled release of widely used antibacterial drugs, cephalexin and metronidazole, from zinc-based MOF-5 incorporated in biodegradable polycaprolactone (PCL) and poly-lactic glycolic acid (PLGA) membranes. Cephalexin and metronidazole were separately incorporated in MOF-5 post-synthetically, followed by their integration into biodegradable PLGA and PCL membranes. The pristine MOF-5 and the loaded MOFs were thoroughly characterized by FT-IR, SEM, TGA and PXRD. Drug release studies were carried out to assess the release rate of the drugs in PBS and distilled water for up to 48 hours using UV-Vis Spectroscopy. Four bacterial strains from both the Gram-positive and Gram-negative types, Staphylococus aureus, Staphylococuss epidermidis, Escherichia coli, Acinetobacter baumanii, were tested against the pristine MOF, pure drugs, loaded MOFs and the drug-loaded MOF-polymer composites. Metronidazole-loaded MOF-5 composite of PLGA (PLGA-Met@MOF-5) was found to show highest efficiency to inhibit the growth of S. epidermidis compared to the other bacteria strains while maintaining a sustained minimum inhibitory concentration (MIC). This study demonstrates that the combination of biodegradable MOF-polymer composites can provide an efficient platform for sustained and controlled release of antimicrobial drugs, and can be a potential strategy to integrate them in biomedical devices.

Keywords: antimicrobial resistance, biodegradable polymers, cephalexin, drug release metronidazole, MOF-5, PCL, PLGA

Procedia PDF Downloads 55

Authors: Ngonidzashe Moyo, Mmaditshaba Rapatsa

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The primary objective of this study was to determine heavy metal contamination in the water, sediment, grass and fish in Sand River, South Africa. This river passes through an urban area and sewage effluent is discharged into it. Water from the Sand river is subsequently used for irrigation downstream of the sewage treatment works. The suitability of this water and the surrounding boreholes for irrigation was determined. This study was undertaken between January, 2014 and January, 2015. Monthly samples were taken from four sites. Sites 1 was upstream of the Polokwane Wastewater Treatment Plant, sites 2, 3 and 4 were downstream. Ten boreholes in the vicinity of the Sand River were randomly selected and the water was tested for heavy metal contamination. The concentration of heavy metals in Sand River water followed the order Mn>Fe>Pb>Cu≥Zn≥Cd. Manganese concentration averaged 0.34 mg/L. Heavy metal concentration in the sediment, grass and fish followed the order Fe>Mn>Zn>Cu>Pb>Cd. The bioaccumulation factor from grass to fish was highest in manganese (19.25), followed by zinc (16.39) and iron (14.14). Soil permeability index (PI) and sodium adsorption ratio (SAR) were used to determine the suitability of Sand River and borehole water for irrigation. The PI index for Sand River water was 75.1% and this indicates that Sand River water is suitable for irrigation of crops. The PI index for the borehole water ranged from 65.8-72.8% and again this indicates suitability of borehole water for crop irrigation. The sodium adsorption ratio also indicated that both Sand River and borehole water were suitable for irrigation. A risk assessment study is recommended to determine the suitability of the fish for human consumption.

Keywords: bioaccumulation, bioavailability, heavy metals, sodium adsorption ratio

Procedia PDF Downloads 192

Authors: Kusum Kumari, Ramesh Banoth, V. S. Reddy Channu

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Organic-inorganic perovskite solar cells (PrSCs) have emerged as a promising solar photovoltaic technology in terms of realizing high power conversion efficiency (PCE). However, their limited lifetime and poor device stability limits their commercialization in future. In this regard, interface engineering of the electron transport layer (ETL) using 2D materials have been currently used owing to their high carrier mobility, high thermal stability and tunable work function, which in turn enormously impact the charge carrier dynamics. In this work, we report an easy and effective way of simultaneously enhancing the efficiency of PrSCs along with the long-term stability through interface engineering via the incorporation of 2D-Molybdenum disulfide (2D-MoS₂, few layered nanoflakes) in mesoporous-Titanium dioxide (mp-TiO₂)scaffold electron transport buffer layer, and using poly 3-hexytheophene (P3HT) as hole transport layers. The PSCs were fabricated in ambient air conditions in device configuration, FTO/c-TiO₂/mp-TiO₂:2D-MoS₂/CH3NH3PbI3/P3HT/Au, with an active area of 0.16 cm². The best device using c-TiO₂/mp-TiO₂:2D-MoS₂ (0.5wt.%) ETL exhibited a substantial increase in PCE ~13.04% as compared to PCE ~8.75% realized in reference device fabricated without incorporating MoS₂ in mp-TiO₂ buffer layer. The incorporation of MoS₂ nanoflakes in mp-TiO₂ ETL not only enhances the PCE to ~49% but also leads to better device stability in ambient air conditions without encapsulation (retaining PCE ~86% of its initial value up to 500 hrs), as compared to ETLs without MoS₂.

Keywords: perovskite solar cells, MoS₂, nanoflakes, electron transport layer

Procedia PDF Downloads 46

Authors: E. Soboleva, E. Sergachyova, S. G. Davydenko, T. V. Meledina

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Problem of food preservation is extremely important for mankind. Viscous damage ("illness") of bread results from development of Bacillus spp. bacteria. High temperature resistant spores of this microorganism are steady against 120°C) and remain in bread during pastries, potentially causing spoilage of the final product. Scientists are interested in further characterization of bread spoiling Bacillus spp. species. Our aim was to find weather yeast Saccharomyces cerevisiae strains that are able to produce natural antimicrobial killer factor can preserve bread illness. By diffusion method, we showed yeast antagonistic activity against spore-forming bacteria. Experimental technological parameters were the same as for bakers' yeasts production on the industrial scale. Risograph test during dough fermentation demonstrated gas production. The major finding of the study was a clear indication of the presence of killer yeast strain antagonistic activity against rope in bread causing bacteria. After demonstrating antagonistic effect of S. cerevisiae on bacteria using solid nutrient medium, we tested baked bread under provocative conditions. We also measured formation of carbon dioxide in the dough, dough-making duration and quality of the final products, when using different strains of S. cerevisiae. It is determined that the use of yeast S. cerevisiae RCAM 01730 killer strain inhibits appearance of rope in bread. Thus, natural yeast antimicrobial killer toxin, produced by some S. cerevisiae strains is an anti-rope in bread protector.

Keywords: bakers' yeasts, killer toxin, rope in bread, Saccharomyces cerevisiæ

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Authors: Frantisek Odvarka

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Based on the data from the Moravian Karst, the influence of the calcite speleothem growth by selected meteorological factors was evaluated. External temperature was determined as one of the main factors influencing speleothem growth in Moravian Karst. This factor significantly influences the CO₂ concentration in soil/epikarst, and cave atmosphere in the Moravian Karst and significantly contributes to the changes in the CO₂ partial pressure differences between soil/epikarst and cave atmosphere in Moravian Karst, which determines the drip water supersaturation with respect to the calcite and quantity of precipitated calcite in the Moravian Karst cave environment. External air temperatures and cave air temperatures were measured using a COMET S3120 data logger, which can measure temperatures in the range from -30 to +80 °C with an accuracy of ± 0.4 °C. CO₂ concentrations in the cave and soils were measured with a FT A600 CO₂H Ahlborn probe (value range 0 ppmv to 10,000 ppmv, accuracy 1 ppmv), which was connected to the data logger ALMEMO 2290-4, V5 Ahlborn. The soil temperature was measured with a FHA646E1 Ahlborn probe (temperature range -20 to 70 °C, accuracy ± 0.4 °C) connected to an ALMEMO 2290-4 V5 Ahlborn data logger. The airflow velocities into and out of the cave were monitored by a FVA395 TH4 Thermo anemometer (speed range from 0.05 to 2 m s⁻¹, accuracy ± 0.04 m s⁻¹), which was connected to the ALMEMO 2590-4 V5 Ahlborn data logger for recording. The flow was measured in the lower and upper entrance of the Imperial Cave. The data were analyzed in MS Office Excel 2019 and PHREEQC.

Keywords: speleothem growth, carbon dioxide partial pressure, Moravian Karst, external temperature

Procedia PDF Downloads 119

Authors: Rujira Jitrwung, Kuntima Krekkeitsakul, Weerawat Patthaveekongka, Chiraphat Kumpidet, Jarukit Tepkeaw, Krissana Jaikengdee, Anantachai Wannajampa

Abstract:

Flue gas discharging from coal fired or gas combustion power plant contains around 12% Carbon dioxide (CO₂), 6% Oxygen (O₂), and 82% Nitrogen (N₂).CO₂ is a greenhouse gas which has been concerned to the global warming. Carbon Capture, Utilization, and Storage (CCUS) is a topic which is a tool to deal with this CO₂ realization. Flue gas is drawn down from the chimney and filtered, then it is compressed to build up the pressure until 8 bar. This compressed flue gas is sent to three stages Pressure Swing Adsorption (PSA), which is filled with activated carbon. Experiments were showed the optimum adsorption pressure at 7bar, which CO₂ can be adsorbed step by step in 1st, 2nd, and 3rd stage, obtaining CO₂ concentration 29.8, 66.4, and 96.7 %, respectively. The mixed gas concentration from the last step is composed of 96.7% CO₂,2.7% N₂, and 0.6%O₂. This mixed CO₂product gas obtained from 3 stages PSA contained high concentration CO₂, which is ready to use for methanol synthesis. The mixed CO₂ was experimented in 5 Liter/Day of methanol synthesis reactor skid by 3 step processes as followed steam reforming, reverse water gas shift, and then hydrogenation. The result showed that proportional of mixed CO₂ and CH₄ 70/30, 50/50, 30/70 % (v/v), and 10/90 yielded methanol 2.4, 4.3, 5.6, and 6.0 Liter/day and save CO₂ 40, 30, 20, and 5 % respectively. The optimum condition resulted both methanol yield and CO₂ consumption using CO₂/CH₄ ratio 43/57 % (v/v), which yielded 4.8 Liter/day methanol and save CO₂ 27% comparing with traditional methanol production from methane steam reforming (5 Liter/day)and absent CO₂ consumption.

Keywords: carbon capture utilization and storage, pressure swing adsorption, reforming, reverse water gas shift, methanol

Procedia PDF Downloads 157

Authors: S. Ghanaraja, Subrata Ray, S. K. Nath

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Particle reinforced Metal Matrix Composite (MMC) succeeds in synergizing the metallic matrix with ceramic particle reinforcements to result in improved strength, particularly at elevated temperatures, but adversely it affects the ductility of the matrix because of agglomeration and porosity. The present study investigates the outcome of tensile properties in a cast and hot forged composite reinforced simultaneously with coarse and fine particles. Nano-sized alumina particles have been generated by milling mixture of aluminum and manganese dioxide powders. Milled particles after drying are added to molten metal and the resulting slurry is cast. The microstructure of the composites shows good distribution of both the size categories of particles without significant clustering. The presence of nanoparticles along with coarser particles in a composite improves both strength and ductility considerably. Delay in debonding of coarser particles to higher stress is due to reduced mismatch in extension caused by increased strain hardening in presence of the nanoparticles. However, higher addition of powder mix beyond a limit results in deterioration of mechanical properties, possibly due to clustering of nanoparticles. The porosity in cast composite generally increases with the increasing addition of powder mix as observed during process and on forging it has got reduced. The base alloy and nanocomposites show improvement in flow stress which could be attributed to lowering of porosity and grain refinement as a consequence of forging.

Keywords: aluminium, alumina, nano-particle reinforced composites, porosity

Procedia PDF Downloads 223

Authors: M. A. Fouad, M. A. Badr, Z. S. Abd El-Rehim, Taher Halawa, Mahmoud Bayoumi, M. M. Ibrahim

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Renewable energy-based micro-grids are presently attracting significant consideration. The smart grid system is presently considered a reliable solution for the expected deficiency in the power required from future power systems. The purpose of this study is to determine the optimal components sizes of a micro-grid, investigating technical and economic performance with the environmental impacts. The micro grid load is divided into two small factories with electricity, both on-grid and off-grid modes are considered. The micro-grid includes photovoltaic cells, back-up diesel generator wind turbines, and battery bank. The estimated load pattern is 76 kW peak. The system is modeled and simulated by MATLAB/Simulink tool to identify the technical issues based on renewable power generation units. To evaluate system economy, two criteria are used: the net present cost and the cost of generated electricity. The most feasible system components for the selected application are obtained, based on required parameters, using HOMER simulation package. The results showed that a Wind/Photovoltaic (W/PV) on-grid system is more economical than a Wind/Photovoltaic/Diesel/Battery (W/PV/D/B) off-grid system as the cost of generated electricity (COE) is 0.266 $/kWh and 0.316 $/kWh, respectively. Considering the cost of carbon dioxide emissions, the off-grid will be competitive to the on-grid system as COE is found to be (0.256 $/kWh, 0.266 $/kWh), for on and off grid systems.

Keywords: renewable energy sources, micro-grid system, modeling and simulation, on/off grid system, environmental impacts

Procedia PDF Downloads 242

Authors: Muhammad Rafiullah Khan, Vanee Chonhenchob

Abstract:

The effect of sodium alginate (1%) based edible coating incorporated natural essential oils; thymol, carvone and carvacrol as antimicrobial agents at different concentrations (0.1, 0.5 and 1.0 %) on the quality changes of fresh-cut pineapple were investigated. Pineapple dipped in distilled water was served as control. After coating, fruit were sealed in a modified atmosphere package (MAP) using high permeable film; and stored at 5 °C. Gas composition in package headspace, color values (L*, a*, b*, C*), TSS, pH, ethanol, browning, and microbial decay were monitored during storage. Oxygen concentration continuously decreased while carbon dioxide concentration inside all packages continuously increased over time. Color parameters (L*, b*, c*) decreased and a* values increased during storage. All essential oils significantly (p ≤ 0.05) prevented microbial growth than control. A significantly higher (p ≤ 0.05) ethanol content was found in the control than in all other treatments. Visible microbial growth, high ethanol, and low color values limited the shelf life to 6 days in control as compared to 9 days in all other treatments. Among all essential oils, thymol at all concentrations maintained the overall quality of the pineapple and could potentially be used commercially in fresh fruit industries for longer storage.

Keywords: essential oils, antibrowning agents, antimicrobial agents, modified atmosphere packaging, pineapple, microbial decay

Procedia PDF Downloads 33

Authors: Muhammad Rafiullah Khan, Vanee Chonhenchob

Abstract:

The effect of sodium alginate (1%) based edible coating incorporated natural essential oils, thymol, carvone, and carvacrol as antimicrobial agents at different concentrations (0.1, 0.5, and 1.0%) on the quality changes of fresh-cut pineapple was investigated. Pineapple dipped in distilled water was served as control. After coating, the fruit was sealed in a modified atmosphere package (MAP) using high permeable film and stored at 5°C. Gas composition in package headspace, color values (L*, a*, b*, C*), TSS, pH, ethanol, browning, and microbial decay were monitored during storage. Oxygen concentration continuously decreased while carbon dioxide concentration inside all packages continuously increased over time. Color parameters (L*, b*, c*) decreased, and a* values increased during storage. All essential oils significantly (p ≤ 0.05) prevented microbial growth than control. A significantly higher (p ≤ 0.05) ethanol content was found in the control than in all other treatments. Visible microbial growth, high ethanol, and low color values limited the shelf life to 6 days in control as compared to 9 days in all other treatments. Among all essential oils, thymol at all concentrations maintained the overall quality of the pineapple and could potentially be used commercially in fresh fruit industries for longer storage.

Keywords: essential oils, antibrowning agents, antimicrobial agents, modified atmosphere packaging, microbial decay, pineapple

Procedia PDF Downloads 30

Authors: Abraham Addo-Bediako, Sophy Nukeri, Tebatso Mmako

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Many freshwater ecosystems have been subjected to prolonged and cumulative pollution as a result of human activities such as mining, agricultural, industrial and human settlements in their catchments. The objective of this study was to investigate spatial variability of heavy metal pollution of sediments and possible sources of pollutants in two streams of the Olifants River System, South Africa. Stream sediments were collected and analysed for Arsenic (As), Cadmium (Cd), Chromium (Cr), Copper (Cu), Lead (Pb), Nickel (Ni) and Zinc (Zn) concentrations using inductively coupled plasma-mass mass spectrometry (ICP-MS). In both rivers, As, Cd, Cu, Pb and Zn fell within the concentration ranges recommended by CCME and ANZECC, while the concentrations of Cr and Ni exceeded the standards; the results indicated that Cr and Ni in the sediments originated from human activities and not from natural geological background. The index of geo-accumulation (Igeo) was used to assess the degree of pollution. The results of the geo-accumulation index evaluation showed that Cr and Ni were present in the sediments of the rivers at moderately to extremely polluted levels, while As, Cd, Cu, Pb and Zn existed at unpolluted to moderately polluted levels. Generally, heavy metal concentrations increased along the gradient in the rivers. The high concentrations of Cr and Ni in both rivers are of great concern, as previously these two rivers were classified to be supplying the Olifants River with water of good quality. There is a critical need, therefore to monitor heavy metal concentrations and distributions, as well as a comprehensive plan to prevent health risks, especially those communities still reliant on untreated water from the rivers, as sediment pollution may pose a risk of secondary water pollution under sediment disturbance and/or changes in the geo-chemistry of sediments.

Keywords: geo-accumulation index, heavy metals, sediment pollution, water quality

Procedia PDF Downloads 133

Authors: Patricia Mikchaela D. L. Feliciano, Ciela Kadeshka A. Fuentes, Bea Trixia B. Gales, Ethel Princess A. Gepulango, Martin R. Hernandez, Elina Andrea S. Lantion, Jhoe Cynder P. Legaspi, Peter F. Quilala, Gina C. Castro

Abstract:

Propolis is a resin-like material used by bees to fill large gap holes in the beehive. It has been found to possess anti-inflammatory property, which stimulates hair growth in rats by inducing hair keratinocytes proliferation, causing water retention and preventing damage caused by heat, ultraviolet rays, and other microorganisms without abnormalities in hair follicles. The present study aimed to formulate 10% and 30% Propolis Hair Cream for use in enhancing hair properties. Raw propolis sample was tested for heavy metals using Atomic Absorption Spectroscopy; zinc and chromium were found to be present. Likewise, propolis was extracted in a percolator using 70% ethanol and concentrated under vacuum using a rotary evaporator. The propolis extract was analyzed for total flavonoid content. Compatibility of the propolis extract with excipients was evaluated using Differential Scanning Calorimetry (DSC). No significant changes in organoleptic properties, pH and viscosity of the formulated creams were noted after four weeks of storage at 2-8°C, 30°C, and 40°C. The formulated creams were found to be non-irritating based on the Modified Draize Rabbit Test. In vivo efficacy was evaluated based on thickness and tensile strength of hair grown on previously shaved rat skin. Results show that the formulated 30% propolis-based cream had greater hair enhancing properties than the 10% propolis cream, which had a comparable effect with minoxidil.

Keywords: atomic absorption spectroscopy, differential scanning calorimetry (DSC), modified draize rabbit test, propolis

Procedia PDF Downloads 312

Authors: Muhammad Saeed, Sheeba Khalid

Abstract:

Aqueous pollution due to the textile industry is an important issue. Photocatalysis using metal oxides as catalysts is one of the methods used for eradication of dyes from textile industrial effluents. In this study, the synthesis, characterization, and evaluation of photocatalytic activity of Ag-TiO₂ are reported. TiO₂ catalysts with 2, 4, 6 and 8% loading of Ag were prepared by green methods using Azadrachea indica leaves' extract as reducing agent and titanium dioxide and silver nitrate as precursor materials. The 4% Ag-TiO₂ exhibited the best catalytic activity for degradation of dyes. Prepared catalyst was characterized by advanced techniques. Catalytic degradation of methylene blue and rhodamine B were carried out in Pyrex glass batch reactor. Deposition of Ag greatly enhanced the catalytic efficiency of TiO₂ towards degradation of dyes. Irradiation of catalyst excites electrons from conduction band of catalyst to valence band yielding an electron-hole pair. These photoexcited electrons and positive hole undergo secondary reaction and produce OH radicals. These active radicals take part in the degradation of dyes. More than 90% of dyes were degraded in 120 minutes. It was found that there was no loss catalytic efficiency of prepared Ag-TiO₂ after recycling it for two times. Photocatalytic degradation of methylene blue and rhodamine B followed Eley-Rideal mechanism which states that dye reacts in fluid phase with adsorbed oxygen. 27 kJ/mol and 20 kJ/mol were found as activation energy for photodegradation of methylene blue and rhodamine B dye respectively.

Keywords: TiO₂, Ag-TiO₂, methylene blue, Rhodamine B., photo degradation

Procedia PDF Downloads 133