Search results for: chemical profile

Authors: M. Shaheed Hartley

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There has been increasing pressure on education researchers and practitioners at higher education institutions to focus on the development of South Africa’s rural and peri-urban communities and improving their quality of life. Many tertiary institutions are obliged to review their outreach interventions in schools. To ensure that the support provided to schools is still relevant, a systemic evaluation of science educator needs is central to this process. These prioritised needs will serve as guide not only for the outreach projects of tertiary institutions, but also to service providers in general so that the process of addressing educators needs become coordinated, organised and delivered in a systemic manner. This paper describes one area of a broader needs assessment exercise to collect data regarding the needs of educators in a district of 45 secondary schools in the Western Cape Province of South Africa. This research focuses on the needs and challenges faced by science educators at these schools as articulated by the relevant stakeholders. The objectives of this investigation are two-fold: (1) to create a data base that will capture the needs and challenges identified by science educators of the selected secondary schools; and (2) to develop a needs profile for each of the participating secondary schools that will serve as a strategic asset to be shared with the various service providers as part of a community of practice whose core business is to support science educators and science education at large. The data was collected by a means of a needs assessment questionnaire (NAQ) which was developed in both actual and preferred versions. An open-ended questionnaire was also administered which allowed teachers to express their views. The categories of the questionnaire were predetermined by participating researchers, educators and education department officials. Group interviews were also held with the science teachers at each of the schools. An analysis of the data revealed important trends in terms of science educator needs and identified schools that can be clustered around priority needs, logistic reasoning and educator profiles. The needs database also provides opportunity for the community of practice to strategise and coordinate their interventions.

Keywords: needs assessment, science and mathematics education, evaluation, teaching and learning, South Africa

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Authors: Fatima Arrutia, Francisco Amador Riera

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The meat industry generates large volumes of blood as a result of meat processing. Several industrial procedures have been implemented in order to treat this by-product, but are focused on the production of low-value products, and in many cases, blood is simply discarded as waste. Besides, in addition to economic interests, there is an environmental concern due to bloodborne pathogens and other chemical contaminants found in blood. Consequently, there is a dire need to find extensive uses for blood that can be both applicable to industrial scale and able to yield high value-added products. Blood has been recognized as an important source of protein. The main blood serum protein in mammals is serum albumin. One of the top trends in food market is functional foods. Among them, bioactive peptides can be obtained from protein sources by microbiological fermentation or enzymatic and chemical hydrolysis. Bioactive peptides are short amino acid sequences that can have a positive impact on health when administered. The main drawback for bioactive peptide production is the high cost of the isolation, purification and characterization techniques (such as chromatography and mass spectrometry) that make unaffordable the scale-up. On the other hand, membrane technologies are very suitable to apply to the industry because they offer a very easy scale-up and are low-cost technologies, compared to other traditional separation methods. In this work, the possibility of obtaining bioactive peptide fractions from serum albumin by means of a simple procedure of only 2 steps (hydrolysis and membrane filtration) was evaluated, as an exploratory study for possible industrial application. The methodology used in this work was, firstly, a tryptic hydrolysis of serum albumin in order to release the peptides from the protein. The protein was previously subjected to a thermal treatment in order to enhance the enzyme cleavage and thus the peptide yield. Then, the obtained hydrolysate was filtered through a nanofiltration/ultrafiltration flat rig at three different pH values with two different membrane materials, so as to compare membrane performance. The corresponding permeates were analyzed by liquid chromatography-tandem mass spectrometry technology in order to obtain the peptide sequences present in each permeate. Finally, different concentrations of every permeate were evaluated for their in vitro antihypertensive and antioxidant activities though ACE-inhibition and DPPH radical scavenging tests. The hydrolysis process with the previous thermal treatment allowed achieving a degree of hydrolysis of the 49.66% of the maximum possible. It was found that peptides were best transmitted to the permeate stream at pH values that corresponded to their isoelectric points. Best selectivity between peptide groups was achieved at basic pH values. Differences in peptide content were found between membranes and also between pH values for the same membrane. The antioxidant activity of all permeates was high compared with the control only for the highest dose. However, antihypertensive activity was best for intermediate concentrations, rather than higher or lower doses. Therefore, although differences between them, all permeates were promising regarding antihypertensive and antioxidant properties.

Keywords: bioactive peptides, bovine serum albumin, hydrolysis, membrane filtration

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Authors: Nasrin Amirrajab, Yasaman Razavi Ghahfarokhi, Zahra Tootak, Maryam Hadian, Fatemeh Abooali Shamshiri

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Urinary tract infections (UTIs) have been reported in children with nephrotic syndrome. However, the only causes for the infection reported to date are bacteria, but not many prior reported occurrences of fungi or yeast as causative organisms. Hence, the present study aimed to describe the epidemiology of urinary tract fungal infections in a tertiary care pediatric. A single-center cross-sectional study was conducted at the nephrology ward of Aboozar Pediatric Hospital between March 21, 2021, and April 28, 2022. Urine was collected aseptically from children, inoculated onto culture media, and incubated at 37 °C for 18–48 hours. Yeast was identified following standard procedures. Antifungal susceptibility testing was determined by the disk diffusion method according to the CLSI guideline. Descriptive statistics and logistical regressions were used to estimate the crude ratio with a 95% confidence interval. P-value < 0.05 was considered significant. Among 68 individuals referred to the mycology lab, the result of direct examination and culture of all patients approved for C.albicans. Of these, 38 individuals (55.8%) were male, and 30 (44.2%) were female. The patients' age ranges were between one month and an 18-year-old. In the study of infection intensity, the patients were classified into three levels such as few (73.5%), moderate (20.6%), and many (5.9%). In the present study, all the patients were sensitive to Posaconazole. Also, the eagle effect was found in Amphotericin B, Voriconazole, and Fluconazole with frequencies of 91.7%, 91.7%, and 83%, respectively. In addition, just 8.3% of isolates were resistant to Itraconazole. It has not shown resistance in other mentioned medicine. The patients showed an intermediate response to Itraconazole (91.7%), Fluconazole (17%), Voriconazole (8.3%), and Amphotericin B (8.3%). There is a high prevalence of yeast infections in children with suspected UTIs. Also, boys are more likely to get yeast infections, and the severity of the infection is higher than girls. The present study demonstrated the importance of diagnosing and selecting the appropriate drug for urinary tract fungal infections in hospitalized children.

Keywords: urinary tract infections, children, fungal infections, yeast, antifungal susceptibility

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Authors: A. M. Khourshid, I. Sabry

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Friction Stir Welding (FSW), a solid state joining technique, is widely being used for joining Al alloys for aerospace, marine automotive and many other applications of commercial importance. FSW were carried out using a vertical milling machine on Al 5083 alloy pipe. These pipe sections are relatively small in diameter, 5mm, and relatively thin walled, 2 mm. In this study, 5083 aluminum alloy pipe were welded as similar alloy joints using (FSW) process in order to investigate mechanical and microstructural properties .rotation speed 1400 r.p.m and weld speed 10,40,70 mm/min. In order to investigate the effect of welding speeds on mechanical properties, metallographic and mechanical tests were carried out on the welded areas. Vickers hardness profile and tensile tests of the joints as a metallurgical feasibility of friction stir welding for joining Al 6061 aluminum alloy welding was performed on pipe with different thickness 2, 3 and 4 mm,five rotational speeds (485,710,910,1120 and 1400) rpm and a traverse speed (4, 8 and 10)mm/min was applied. This work focuses on two methods such as artificial neural networks using software (pythia) and response surface methodology (RSM) to predict the tensile strength, the percentage of elongation and hardness of friction stir welded 6061 aluminum alloy. An artificial neural network (ANN) model was developed for the analysis of the friction stir welding parameters of 6061 pipe. The tensile strength, the percentage of elongation and hardness of weld joints were predicted by taking the parameters Tool rotation speed, material thickness and travel speed as a function. A comparison was made between measured and predicted data. Response surface methodology (RSM) also developed and the values obtained for the response Tensile strengths, the percentage of elongation and hardness are compared with measured values. The effect of FSW process parameter on mechanical properties of 6061 aluminum alloy has been analyzed in detail.

Keywords: friction stir welding (FSW), al alloys, mechanical properties, microstructure

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Authors: L. Steponavičiūtė, L. Steponavičienė

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Despite the rapid nanotechnology progress and recognition, its potential impact in ecosystems and health of humans is still not fully known. In this paper, the study of ecotoxicological dangers of nanomaterials is presented. By chemical reduction method, silver (AgNPs) and gold (AuNPs) nanoparticles were synthesized, characterized and used in experiments to examine their impact on microorganisms (Escherichia coli, Staphylococcus aureus and Candida albicans) and terrestrial flora (Phaseolus vulgaris and Lepidium sativum). The results collected during experiments with terrestrial flora show tendentious growth stimulations caused by gold nanoparticles. In contrast to these results, silver nanoparticle solutions inhibited growth of beans and garden cress, compared to control samples. The results obtained from experiments with microorganisms show similarities with ones collected from experiments with terrestrial plants. Samples treated with AuNPs of size 13 nm showed stimulation in the growth of the colonies compared with 3,5 nm size nanoparticles.

Keywords: nanomaterials, ecotoxicology, nanoparticles, ecosystems

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Authors: Desta Gebretekle Shiferaw, Balakrishna Kalluraya

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Pyrazole is an aromatic five-membered heterocycle with two nitrogen and three carbon atoms in its ring structure. According to the literature, pyrazoline, pyrazole, and thiazole-containing moieties are found in various drug structures and are responsible for nearly all pharmacological effects. The pyrazoline linked to pyrazole moiety carbothioamides was synthesized via the reaction of pyrazole-bearing chalcones (3-(5-chloro-3-methyl-¹-phenyl-1H-pyrazol-4-yl)-¹-(substituted aryl) prop-2-ene-¹-one derivatives) with a nucleophile thiosemicarbohyrazide by heating in ethanol using fused sodium acetate as a catalyst. Then the carbothioamide derivatives were converted into the pyrazoline hybrid to pyrazole and thiazole derivatives by condensing with substituted phenacyl bromide in alcohol in a basic medium. Next, the chemical structure of the newly synthesized molecules was confirmed by IR, 1H-NMR, and mass spectral data. Further, they were screened for their in vitro antioxidant activity. Compared to butylated hydroxy anisole (BHA)., the antioxidant data showed that the synthesized compounds had good to moderate activity.

Keywords: pyrazoline-pyrazole carbothioamide derivatives, pyrazoline-pyrazole-thiazole derivatives, spectral studies, antioxidant activity

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Authors: Shah Rucksana Akhter Urme

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Agriculture is the main source of food for human consumption and feeding the world huge population, the pressure of food supply is increasing day by day. Undoubtedly, quality strain, improved plantation, farming technology, synthetic fertilizer, readily available irrigation, insecticides and harvesting technology are the main factors those to meet up the huge demand of food consumption all over the world. However, depended on this limited resources and excess amount of consuming lands, water, fertilizers leads to the end of the resources and severe climate effects has been left for our future generation. Agriculture is the most responsible to global warming, emitting more greenhouse gases than all other vehicles largely from nitrous oxide released by from fertilized fields, and carbon dioxide from the cutting of rain forests to grow crops . Farming is the thirstiest user of our precious water supplies and a major polluter, as runoff from fertilizers disrupts fragile lakes, rivers, and coastal ecosystems across the globe which accelerates the loss of biodiversity, crucial habitat and a major driver of wildlife extinction. It is needless to say that we have to more concern on how we can save the nutrients of the soil, storage of the water and avoid excessive depends on synthetic fertilizer and insecticides. In this case, eco- friendly cultivation could be a potential alternative solution to minimize effects of agriculture in our environment. The objective of this review paper is about organic cultivation following in particular biotechnological process focused on bio-fertilizer and bio-pesticides. Intense practice of chemical pesticides, insecticides has severe effect on both in human life and biodiversity. This cultivation process introduces farmer an alternative way which is nonhazardous, cost effective and ecofriendly. Organic fertilizer such as tea residue, ashes might be the best alternative to synthetic fertilizer those play important role in increasing soil nutrient and fertility. Ashes contain different essential and non-essential mineral contents that are required for plant growth. Organic pesticide such as neem spray is beneficial for crop as it is toxic for pest and insects. Recycled and composted crop wastes and animal manures, crop rotation, green manures and legumes etc. are suitable for soil fertility which is free from hazardous chemicals practice. Finally water hyacinth and algae are potential source of nutrients even alternative to soil for cultivation along with storage of water for continuous supply. Inorganic practice of agriculture, consuming fruits and vegetables becomes a threat for both human life and eco-system and synthetic fertilizer and pesticides are responsible for it. Farmers that practice eco-friendly farming have to implement steps to protect the environment, particularly by severely limiting the use of pesticides and avoiding the use of synthetic chemical fertilizers, which are necessary for organic systems to experience reduced environmental harm and health risk.

Keywords: organic farming, biopesticides, organic nutrients, water storage, global warming

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Authors: Aurica P. Chiriac, Vera Balan, Mihai Asandulesa, Elena Butnaru, Nita Tudorachi, Elena Stoleru, Loredana E. Nita, Iordana Neamtu, Alina Diaconu, Liliana Mititelu-Tartau

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The interest for studying ‘smart’ materials is entirely justified and in this context were realized investigations on poly(2-hydroxyethylmethacrylate-co-3, 9-divinyl-2, 4, 8, 10-tetraoxaspiro (5.5) undecane), which is a macromolecular compound with sensibility at pH and temperature, gel formation capacity, binding properties, amphilicity, good oxidative and thermal stability. Physico-chemical characteristics in terms of the molecular weight, temperature-sensitive abilities and thermal stability, as well rheological, dielectric and spectroscopic properties were evaluated in correlation with further coupling capabilities. Differential scanning calorimetry investigation indicated Tg at 36.6 °C and a melting point at Tm=72.8°C, for the studied copolymer, and up to 200oC two exothermic processes (at 99.7°C and 148.8°C) were registered with losing weight of about 4 %, respective 19.27%, which indicate just processes of thermal decomposition (and not phenomena of thermal transition) owing to scission of the functional groups and breakage of the macromolecular chains. At the same time, the rheological studies (rotational tests) confirmed the non-Newtonian shear-thinning fluid behavior of the copolymer solution. The dielectric properties of the copolymer have been evaluated in order to investigate the relaxation processes and two relaxation processes under Tg value were registered and attributed to localized motions of polar groups from side chain macromolecules, or parts of them, without disturbing the main chains. According to literature and confirmed as well by our investigations, β-relaxation is assigned with the rotation of the ester side group and the γ-relaxation corresponds to the rotation of hydroxy- methyl side groups. The fluorescence spectroscopy confirmed the copolymer structure, the spiroacetal moiety getting an axial conformation, more stable, with lower energy, able for specific interactions with molecules from environment, phenomena underlined by different shapes of the emission spectra of the copolymer. Also, the copolymer was used as template for indomethacin incorporation as model drug, and the biocompatible character of the complex was confirmed. The release behavior of the bioactive compound was dependent by the copolymer matrix composition, the increasing of 3, 9-divinyl-2, 4, 8, 10-tetraoxaspiro (5.5) undecane comonomer amount attenuating the drug release. At the same time, the in vivo studies did not show significant differences of leucocyte formula elements, GOT, GPT and LDH levels, nor immune parameters (OC, PC, and BC) between control mice group and groups treated just with copolymer samples, with or without drug, data attesting the biocompatibility of the polymer samples. The investigation of the physico-chemical characteristics of poly(2-hydrxyethyl methacrylate-co-3, 9-divinyl-2, 4, 8, 10-tetraoxaspiro (5.5) undecane) in terms of temperature-sensitive abilities, rheological and dielectrical properties, are bringing useful information for further specific use of this polymeric compound.

Keywords: bioapplications, dielectric and spectroscopic properties, dual sensitivity at pH and temperature, smart materials

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Authors: T. Meftah, M. M. Zerafat, S. Sabbaghi

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Nitrate compounds are considered as groundwater contaminants, the concentration of which has been growing in these resources during recent years. As a result, it seems necessary to use effective methods to remove nitrate from water and wastewater. Adsorption process is generally considered more economical in water treatment. Natural clinoptilolite zeolite is one of the best absorbents because of its high capacity and low cost.In this research, we are going to modify zeolite nanoparticles as a chemical modification. Zeolite nanoparticles have been modified with a kind of organosilane, like 3-aminopropyltriethoxysilane. The advantage of this modification method, in comparison with physical modification, is the good stability in various environmental conditions. In this research, absorbent properties have been analyzed by PSA, FTIR and CHN elemental analysis. Also, nitrate adsorption by modified nanoparticles was examined by UV-Vis spectroscopy. There would be 〖NH〗_2 groups on the zeolite surface as a result of organosilane modification. In order to adsorption of nitrate, we need to convert 〖NH〗_2 groups to〖NH〗_4^+, that it is possible in acidic condition. As a result, the best nitrate removal is possible in the lowest concentration and pH. We obtained 80.12% nitrate removal in pH=3 and 50 mg⁄l nitrate concentration and 4 g⁄l absorbent optimum concentration.

Keywords: nitrate removal, zeolite, surface modification, organosilane

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Authors: Irsha Dhotre

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Cymbopogon citratus is generally known as Indian Lemongrass and is widely applicable in the cosmetic, pharmaceutical, dairy puddings, and food industries. To enhance the quality of extraction, microwave-oven-aided hydro distillation processes were implemented. The basic parameter which influences the rate of extraction is considered, such as the temperature of extraction, the time required for extraction, and microwave-oven power applied. Locally available CKP 25 Cymbopogon citratus was used for the extraction of essential oil. Optimization of Extractions Parameters and full factorial Box–Behnken design (BBD) evaluated by using Design expert 13 software. The regression model revealed that the optimum parameters required for extractions are a temperature of 35℃, a time of extraction of 130 minutes, and microwave-oven power of 700 W. The extraction efficiency of yield is 4.76%. Gas Chromatography-Mass Spectroscopy (GC-MS) analysis confirmed the significant components present in the extraction of lemongrass oil.

Keywords: Box–Behnken design, Cymbopogon citratus, hydro distillation, microwave-oven, response surface methodology

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Authors: Mohamrd Ali Alrabib

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Sandstones samples were selected from cores of seven wells ranging in depth from 5040 to 7181.4 ft. The dominant authigenic cement phase is quartz overgrowth cement (up to 13% by volume) and this is the major mechanism for porosity reduction. Late stage carbonate cements (siderite and dolomite/ferroan dolomite) are present and these minerals infill intergranular porosity and, therefore, further reduce porosity and probably permeability. Authigenic clay minerals are represented by kaolinite, illite, and grain coating clay minerals. Kaolinite occurs as booklet and vermicular forms. Minor amounts of illite were noted in the studied samples, which commonly block pore throats, thereby reducing permeability. Primary porosity of up to 26.5% is present. Secondary porosity (up to 17%) is also present as a result of feldspar dissolution. The high intergranular volume (IGV) of the sandstones indicates that mechanical and chemical compaction played a more important role than cementation of porosity loss.

Keywords: authigenic minerals, porosity types, porosity reduction, mamuniyat sandstone reservoir

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Authors: S. A. Krutovertsev, A. E. Tarasova, L. S. Krutovertseva, O. M. Ivanova

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The aim of the work was to get stable sensitive films with good sensitivity to ethanolamine (C2H7NO) in air. Ethanolamine is used as adsorbent in different processes of gas purification and separation. Besides it has wide industrial application. Chemical sensors of sorption type are widely used for gas analysis. Their behavior is determined by sensor characteristics of sensitive sorption layer. Forming conditions and characteristics of chemical gas sensors based on nanostructured modified silica films activated by different admixtures have been studied. As additives molybdenum containing polyoxometalates of the eighteen series were incorporated in silica films. The method of hydrolythic polycondensation from tetraethyl orthosilicate solutions was used for forming such films in this work. The method’s advantage is a possibility to introduce active additives directly into an initial solution. This method enables to obtain sensitive thin films with high specific surface at room temperature. Particular properties make polyoxometalates attractive as active additives for forming of gas-sensitive films. As catalyst of different redox processes, they can either accelerate the reaction of the matrix with analyzed gas or interact with it, and it results in changes of matrix’s electrical properties Polyoxometalates based films were deposited on the test structures manufactured by microelectronic planar technology with interdigitated electrodes. Modified silica films were deposited by a casting method from solutions based on tetraethyl orthosilicate and polyoxometalates. Polyoxometalates were directly incorporated into initial solutions. Composite nanostructured films were deposited by drop casting method on test structures with a pair of interdigital metal electrodes formed at their surface. The sensor’s active area was 4.0 x 4.0 mm, and electrode gap was egual 0.08 mm. Morphology of the layers surface were studied with Solver-P47 scanning probe microscope (NT-MDT, Russia), the infrared spectra were investigated by a Bruker EQUINOX 55 (Germany). The conditions of film formation varied during the tests. Electrical parameters of the sensors were measured electronically in real-time mode. Films had highly developed surface with value of 450 m2/g and nanoscale pores. Thickness of them was 0,2-0,3 µm. The study shows that the conditions of the environment affect markedly the sensors characteristics, which can be improved by choosing of the right procedure of forming and processing. Addition of polyoxometalate into silica film resulted in stabilization of film mass and changed markedly of electrophysical characteristics. Availability of Mn3P2Mo18O62 into silica film resulted in good sensitivity and selectivity to ethanolamine. Sensitivity maximum was observed at weight content of doping additive in range of 30–50% in matrix. With ethanolamine concentration changing from 0 to 100 ppm films’ conductivity increased by 10-12 times. The increase of sensor’s sensitivity was received owing to complexing reaction of tested substance with cationic part of polyoxometalate. This fact results in intramolecular redox reaction which sharply change electrophysical properties of polyoxometalate. This process is reversible and takes place at room temperature.

Keywords: ethanolamine, gas analysis, polyoxometalate, silica film

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Authors: Lovis Ingrid Hakala

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This paper provides an example of how the dating app Tinder can be used as a tool in queer research and what the use of the app among lesbians can tell us about the production of particular kinds of lesbian identities paired with technology. This study seeks to understand the ways in which the app is understood by lesbian women and how it is brought into their understandings of what being a lesbian means. Dating apps are becoming increasingly common as tools for meeting a potential partner and research has shown how these apps gain new meaning depending on the context. This paper will show both how Tinder has gained a particular meaning in a lesbian context in Bologna, and also how the use of Tinder produces specific ideas of what lesbians are and how they act. While doing ethnographic fieldwork among young lesbians (20-30 years old) in Bologna in the autumn of 2017, as a part of the research methodology, Tinder was used together with interviews and participant observation. By signing up on Tinder and contacting potential informants on the app the aim was to reach women who were not necessarily involved in the queer activist spaces in the city and who might thus provide a different perspective than their activist counterparts. Using Tinder as a tool in research proved to be a useful methodology both when it came to contacting potential informants as well as in gaining a better understanding for queer identity building, and the role Tinder played in defining lesbianism in Bologna. The app itself was often deemed useless, and informants often complained about the lack of women on the app who had their profile showing an interest in women. Apart from being away for the interlocutors to get in touch with potential romantic or sexual partners, the app did provide a concrete object around which to define particular lesbian behavior. Lesbians were described to be slow at answering and not being very eager to meet. This placed lesbian women, in contrast to gay men who were seen as doing the opposite, using dating apps a lot and be quick to propose meetings. Tinder among lesbians in Bologna thus proved to have a dual function as both a way of creating connections between queer women but also as a tool to define what a lesbian is. This paper provides insight into the ways in which dating apps provides a community and identity building function and how a certain behavior on said apps can be a part of defining identity. This work stands out among other literature on dating apps since it does not only focus on the methodological aspects of using Tinder as a tool in research but also provides an insight in how the way in which individuals use the app comes to add to an understanding of what a lesbian is.

Keywords: dating apps, identity, Italy, lesbian, queer

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Authors: Somayyeh Kalami, Mojgan Nejad

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Based on the source (softwood, hardwood or annual crop) and isolation method (kraft, organosolv, sulfite or pre-enzymatic treatment), there are significant variations in lignin structure and properties. The first step in using lignin as biobased feedstock is to make sure that specific lignin is suitable for intended application. Complete characterization of lignin and measuring its chemical, physical and thermal properties can help to predict its suitability. To replace 100% phenol portion of phenolic adhesive, lignin should have high reactivity toward formaldehyde. Theoretically, lignins with closer backbone structure to phenol should be better candidate for this application. In this study, a number of different lignins were characterized and used to formulate phenolic adhesive. One of the main findings was that lignin sample with higher percentage of hydroxyl-phenyl units was better candidate than lignin with more syringyl units. This could be explained by the fact that hydroxyl-phenyl lignin units have two available ortho positions for reaction with formaldehyde while in syringyl units all ortho and para positions are occupied, and there is no available site in lignin structure to react with formaldehyde.

Keywords: lignin, phenolic adhesive, biobased, sustainable

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Authors: Suneeta Kumari, Abanti Sahoo

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Industrial effluents treatment is a major problem in the world. All wastewater treatment methods have some problems in the environment. Due to this reason, today many natural biopolymers are being used in the waste water treatment because those are safe for our environment. In this study, synthesis and characterization of polyethersulfone/chitosan membranes (Thin film composite membrane) are carried out. Fish scales are used as raw materials. Different characterization techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), scanning electron microscope (SEM) and Thermal gravimetric analysis (TGA) are analysed for the synthesized membrane. The performance of membranes such as flux, rejection, and pore size are also checked. The synthesized membrane is used for the treatment of steel industry waste water where Biochemical oxygen demand (BOD), Chemical Oxygen Demand (COD), pH, colour, Total dissolved solids (TDS), Total suspended solids (TSS), Electrical conductivity (EC) and Turbidity aspects are analysed.

Keywords: fish scale, membrane synthesis, treatment of industrial effluents, chitosan

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Authors: A. Benhadji, R. Maachi

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Environmental protection has become a major economic development issues. Indeed, the environment has become both market growth factor and element of competition. It is now an integral part of all industrial strategies. Ecosystem protection is based on the reduction of the pollution load in the treatment of liquid waste. The physicochemical techniques are commonly used which a transfer of pollution is generally found. Alternative to physicochemical methods is the use of microorganisms for cleaning up the waste waters. The objective of this research is the evaluation of the effects of exogenous added Pseudomonas strains on pollutants biodegradation. The influence of the critical parameters such as inoculums concentration and duration treatment are studied. The results show that Pseudomonas putida is found to give a maximum reduction in chemical organic demand (COD) in 4 days of incubation. However, toward to protect biological pollution of environment, the treatment is achieved by electro coagulation process using aluminium electrodes. The results indicate that this process allows disinfecting the water and improving the electro coagulated sludge quality.

Keywords: tannery, pseudomonas, biological treatment, electrocoagulation process, sludge quality

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Authors: Jing Zhao, Yongqing Bai, Qiaofang Shi, Huaihao Zhang

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Advances in software technology enable computational chemistry to be commonly applied in various research fields, especially in pedagogy. Thus, in order to expand and improve experimental instructions of computational chemistry for undergraduates, we designed an introductory experiment—research on acrylamide molecular structure and physicochemical properties. Initially, students construct molecular models of acrylamide and polyacrylamide in Gaussian and Materials Studio software respectively. Then, the infrared spectral data, atomic charge and molecular orbitals of acrylamide as well as solvation effect of polyacrylamide are calculated to predict their physicochemical performance. At last, rheological experiments are used to validate these predictions. Through the combination of molecular simulation (performed on Gaussian, Materials Studio) with experimental verification (rheology experiment), learners have deeply comprehended the chemical nature of acrylamide and polyacrylamide, achieving good learning outcomes.

Keywords: upper-division undergraduate, computer-based learning, laboratory instruction, molecular modeling

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Authors: Moncer Malika, Ben Brahim Mounir, Bel Hassen Malika, Hamza Asma

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During the last decades, microalgae communities have presented significant changes in their structure and taxa composition along the Mediterranean littoral shallow waters. The main purpose of this work was to evaluate possible changes, over a 17-year scale (1997–2013), in the diversity and abundance of three toxic and potentially toxic microalgae related to changes in environmental parameters on Sfax coasts, a pole of shellfish production in Tunisia. In this 17-year span, a chronological series of data showed that a clear disparity from one year to another was observed in the abundance of studied species. The distribution of these species has been subjected to a seasonal cycle. The studied microalgae, especially Prorocentrum lima, seem to have significant relationships with many physicochemicaland meteorological parameters.

Keywords: long-term monitoring HABs, physico-chemical parameters, meteorological parameters, Prorocentrum lima, Ostreopsis cf. ovata, Coolia monotis

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Authors: Perminder JitKaur, Santosh Satya, K. K. Pant, S. N. Naik

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Bamboo is extensively used in construction industry. Low durability of bamboo due to fungus infestation and termites attack under storage puts certain constrains for it usage as modern structural material. Looking at many chemical formulations for bamboo treatment leading to severe harmful environment effects, research on eco-friendly preservatives for bamboo treatment has been initiated world-over. In the present studies, eco-friendly preservative for bamboo treatment has been developed. To validate its application for structural purposes, investigation of effect of treatment on compressive strength has been investigated. Neem oil(25%) integrated with copper naphthenate (0.3%) on dilution with kerosene oil impregnated into bamboo culm at 2 bar pressure, has shown weight loss of only 3.15% in soil block analysis method. The results of compressive strength analysis using The results from compressive strength analysis using HEICO Automatic Compression Testing Machine, reveal that preservative treatment has not altered the structural properties of bamboo culms. Compressive strength of control (11.72 N/mm2) and above treated samples (11.71 N/mm2) was found to be comparable.

Keywords: D. strictus, bamboo, neem oil, presure treatment, compressive strength

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Authors: Ahmed Makhoukh

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Quality assurance (QA) has recently become a common practice, which is endorsed by most Higher Education (HE) institutions worldwide, due to the pressure of internal and external forces. One of the aims of this quality movement is to make the contribution of university education to socio-economic development highly significant. This entails that graduates are currently required have a high-quality profile, i.e., to be competent and master the 21st-century skills needed in the labor market. This wave of change, mostly imposed by globalization, has the effect that university education should be learner-centered in order to satisfy the different needs of students and meet the expectations of other stakeholders. Such a shift of focus on the student learning outcomes has led HE institutions to reconsider their strategic planning, their mission, the curriculum, the pedagogical competence of the academic staff, among other elements. To ensure that the overall institutional performance is on the right way, a QA system should be established to assume this task of checking regularly the extent to which the set of standards of evaluation are strictly respected as expected. This operation of QA has the advantage of proving the accountability of the institution, gaining the trust of the public with transparency and enjoying an international recognition. This is the case of Doha Institute (DI) for Graduate Studies, in Qatar, the object of the present study. The significance of this contribution is to show that the conception of quality has changed in this digital age, and the need to integrate a department responsible for QA in every HE institution to ensure educational quality, enhance learners and achieve academic leadership. Thus, to undertake the issue of QA in DI for Graduate Studies, an elite university (in the academic sense) that focuses on a small and selected number of students, a qualitative method will be adopted in the description and analysis of the data (document analysis). In an attempt to investigate the extent to which QA is achieved in Doha Institute for Graduate Studies, three broad indicators will be evaluated (input, process and learning outcomes). This investigation will be carried out in line with the UK Quality Code for Higher Education represented by Quality Assurance Agency (QAA).

Keywords: accreditation, higher education, quality, quality assurance, standards

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Authors: Vinod Kumar

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Background: Tissue Plasminogen Activator (tPA) showed a level 1 benefit in acute stroke (within 3-6 hrs). Intracarotid sodium nitroprusside (ICSNP) has been studied in this context with a wide treatment window, fast recovery and affordability. This work proposes two mechanisms for acute cases and one mechanism for chronic cases, which are interrelated, for physiological recovery. a)Retrograde Neurotransmission (acute cases): 1)Normal excitatory impulse: at the synaptic level, glutamate activates NMDA receptors, with nitric oxide synthetase (NOS) on the postsynaptic membrane, for further propagation by the calcium-calmodulin complex. Nitric oxide (NO, produced by NOS) travels backward across the chemical synapse and binds the axon-terminal NO receptor/sGC of a presynaptic neuron, regulating anterograde neurotransmission (ANT) via retrograde neurotransmission (RNT). Heme is the ligand-binding site of the NO receptor/sGC. Heme exhibits > 10,000-fold higher affinity for NO than for oxygen (the 10,000-fold effect) and is completed in 20 msec. 2)Pathological conditions: normal synaptic activity, including both ANT and RNT, is absent. A NO donor (SNP) releases NO from NOS in the postsynaptic region. NO travels backward across a chemical synapse to bind to the heme of a NO receptor in the axon terminal of a presynaptic neuron, generating an impulse, as under normal conditions. b)Vasospasm: (acute cases) Perforators show vasospastic activity. NO vasodilates the perforators via the NO-cAMP pathway. c)Long-Term Potentıatıon (LTP): (chronic cases) The NO–cGMP-pathway plays a role in LTP at many synapses throughout the CNS and at the neuromuscular junction. LTP has been reviewed both generally and with respect to brain regions specific for memory/learning. Aims/Study Des’gn: The principles of “generation of impulses from the presynaptic region to the postsynaptic region by very potent RNT (10,000-fold effect)” and “vasodilation of arteriolar perforators” are the basis of the authors’ hypothesis to treat stroke cases. Case-control prospective study. Mater’als And Methods: The experimental population included 82 stroke patients (10 patients were given control treatments without superfusion or with 5% dextrose superfusion, and 72 patients comprised the ICSNP group). The mean time for superfusion was 9.5 days post-stroke. Pre- and post-ICSNP status was monitored by NIHSS, MRI and TCD. Results: After 90 seconds in the ICSNP group, the mean change in the NIHSS score was a decrease of 1.44 points, or 6.55%; after 2 h, there was a decrease of 1.16 points; after 24 h, there was an increase of 0.66 points, 2.25%, compared to the control-group increase of 0.7 points, or 3.53%; at 7 days, there was an 8.61-point decrease, 44.58%, compared to the control-group increase of 2.55 points, or 22.37%; at 2 months in ICSNP, there was a 6.94-points decrease, 62.80%, compared to the control-group decrease of 2.77 points, or 8.78%. TCD was documented and improvements were noted. Conclusions: ICSNP is a swift-acting drug in the treatment of stroke, acting within 90 seconds on day 9.5 post-stroke with a small decrease after 24 hours. The drug recovers from this decrease quickly.

Keywords: brain infarcts, intracarotid sodium nitroprusside, perforators, vasodilatıons, retrograde transmission, the 10, 000-fold effect

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Authors: Kübra Aktaş, Nihat Akin

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Tarhana is a traditional Turkish fermented food. It is widely consumed as soup and includes many different ingredients such as wheat flour, various vegetables, and spices, yoghurt, bakery yeast. It can also be enriched by adding other ingredients. Thus, its nutritional properties can be enhanced. In this study, tarhana was supplemented with two different types of brans (rice bran and corn bran) and WPC (whey protein concentrate powder) to improve its nutritional and functional properties. Some chemical properties of tarhana containing two different brans and their levels (0, 5, 10 and 15%) and WPC (0, 5, 10%) were investigated. The results indicated that addition of WPC increased ash content in tarhanas which were fortified with rice and corn bran. The highest antioxidant and phenolic content values were obtained with addition of rice bran in tarhana formulation. Compared to tarhana with corn bran, rice bran addition gave higher oil content values. The cellulose content of tarhana samples was determined between 0.75% and 2.74% and corn bran showed an improving effect on cellulose contents of samples. In terms of protein content, addition of WPC into the tarhana raised protein content for the samples.

Keywords: corn, rice, tarhana, whey

Procedia PDF Downloads 341

Authors: Peder O. Laugen Heggdal, Oyvind Nordvik, Jonas Brannstrom, Flemming Vassbotn, Anne Kari Aarstad, Hans Jorgen Aarstad

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Background: Hearing loss (HL) affect people of all ages and stages in life. To author's best knowledge, if patients with an HL have reduced Generic Quality of life (QoL), has yet not been answered. Aim: The aim of the present study was to investigate the relationship between HL and generic and disease-specific Health Related Quality of Life (HRQoL) in adult patients (aged 18–78 years) with an HL, seeking Hearing Aid (HA). Material and Methods: 158 adult (aged 18-78 years) patients with HL, referred for HA fitting at Haukeland University Hospital in western Norway, participated in the study. Both first-time users, as well as patients referred for HA renewals, were included. First-time users had been pre-examined by an Ear Nose and Throat specialist. The questionnaires were answered before the actual HA fitting procedure. The pure-tone average (PTA; frequencies 0.5, 1, 2 and 4 kHz) was determined for each ear. The generic European Organization for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire general part and a shortened version of the Abbreviated Profile of Hearing Aid Benefit (APHAB) were answered. In addition, EORTC HRQoL answers from a general population and patients with former head and neck cancer served as comparison. Results: In general, no lowered HRQoL scores were determined among HL patients compared to the general population. Patients with unilateral HL to some extent showed lower HRQoL than those with bilateral HL (social function and fatigue). The APHAB scores correlated significantly with the EORTC HRQoL scores. By stepwise linear regression analysis, the APHAB scores were scored secondary to PTA (best ear), cognitive and physical function. Conclusion: HRQoL scores in HL patients, in general, seems to be at the population level, but the unilateral HL patients scored to some extent lower than the bilateral HI patients. APHAB and generic QoL scores levels are associated. Both HRQoL and APHAB scores are generated more complexly than anticipated.

Keywords: quality of life, hearing loss, hearing impairment, distress, depression, anxiety, hearing aid

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Authors: Susmita Sharma, Pankaj Pathak

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Biosolids are by-products of municipal and industrial wastewater treatment process. The generation of the biosolids is increasing at an alarming rate due to the implementation of strict environmental legislation to improve the quality of discharges from wastewater treatment plant. As such, proper management and safe disposal of sewage sludge have become a worldwide topic of research. Biosolids, rich in organic matter and essential micro and macronutrients; can be used as a soil conditioner, to cut fertilizer costs and create favorable conditions for vegetation. However, it also contains pathogens and heavy metals which are undesirable as they are harmful to both humans and the environment. Therefore, for safe utilization of biosolids for land application purposes, categorization of the contaminant and pathogen is mandatory. In this context, biosolids collected from a wastewater treatment plant in Maharashtra are utilized to determine its physical, chemical and microbiological attributes. This study would ascertain, if the use of these materials from the specific site, are suitable for agriculture. Further, efforts have also been made to present the internationally acceptable legal standards and guidelines for biosolids management or application.

Keywords: biosolids, sewage, heavy metal, sustainable agriculture

Procedia PDF Downloads 332

Authors: T. Büyüksırıt, H. Kuleaşan

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Natural antimicrobials are used to preserve foods that can be found in plants, animals, and microorganisms. Antimicrobial substances are natural or artificial agents that produced by microorganisms or obtained semi/total chemical synthesis are used at low concentrations to inhibit the growth of other microorganisms. Food borne pathogens and spoilage microorganisms are inactivated by the use of antagonistic microorganisms and their metabolites. Yeasts can produce toxic proteins or glycoproteins (toxins) that cause inhibition of sensitive bacteria and yeast species. Antimicrobial substance producing phenotypes belonging different yeast genus were isolated from different sources. Toxins secreted by many yeast strains inhibiting the growth of other yeast strains. These strains show antimicrobial activity, inhibiting the growth of mold and bacteria. The effect of antimicrobial agents produced by yeasts can be extremely fast, and therefore may be used in various treatment procedures. Rapid inhibition of microorganisms is possibly caused by microbial cell membrane lipopolysaccharide binding and in activation (neutralization) effect. Antimicrobial agents inhibit the target cells via different mechanisms of action.

Keywords: antimicrobial agents, yeast, toxic protein, glycoprotein

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Authors: Lawan Muhammad Adam, Abduljabar Hilal Alsayoud

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One of the most promising techniques to produce pure hydrogen is through a palladium-based membrane (Pd-membrane). Density functional theory (DFT) is employed in this work to examine how the physical and chemical adsorption properties of hydrogen on the surface of Pd-Pt can be mutated in the presence of contaminating gases, CH₄, CO, and CO₂. The main target is to survey the energy topology related to hydrogen adsorption while adjusting the stages of freedom in both the structure and composition. The adsorption sites, crystal plane of the slab, and relative orientation of the adsorbed molecules on its surface, as well as various arrangements of adsorbed species, have been considered in this study. The dependency of hydrogen adsorption on surface coverage is studied. The study demonstrated the physical adsorption energies of the molecules on the surface concerning the different coverages of hydrogen atoms. The most stable combinations of the adsorption sites (Top, Hollow, and Bridge) with various orientations of gaseous molecules on the Pd-Pt surface were identified according to their calculated energies. When the binding of contaminating gaseous species to the Pd-Pt surface and their impact on the physical adsorption energies of the H₂ are examined, it is observed that the most poisonous gas relative to all other gases modifies the energetics of the adsorption process of hydrogen on the surface.

Keywords: DFT, Pd-Pt-membrane, H₂, CO, CO₂

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Authors: Saikat Datta

Abstract:

Incompressible laminar time-varying flow is investigated over a rounded backward-facing step for a triangular piston motion at the inlet of a straight channel with very high acceleration, followed by a slow deceleration experimentally and through numerical simulation. The backward-facing step is an important test-case as it embodies important flow characteristics such as separation point, reattachment length, and recirculation of flow. A sliding piston imparts two successive triangular velocities at the inlet, constant acceleration from rest, 0≤t≤t0, and constant deceleration to rest, t0≤tKeywords: laminar boundary layer separation, rounded backward facing step, separation bubble, unsteady separation, unsteady vortex flows

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Authors: Semra Çoruh, Yusuf Tibet

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Dyes are widely used in industries such as textiles, paper, paints, leather, rubber, plastics, cosmetics, food, and drug etc, to color their products. Due to their chemical structures, dyes are resistant to fading on exposure to light, water and many chemicals and, therefore, are difficult to be decolorized once released into the aquatic environment. Many of the organic dyes are hazardous and may affect aquatic life and even the food chain. This study deals with the adsorption of malachite green dye onto fly ash and red mud. The effects of experimental factors (adsorbent dosage, initial concentration, pH and temperature) on the adsorption process were examined by using 24 full factorial design. The results were statistically analyzed by using the student’s t-test, analysis of variance (ANOVA) and an F-test to define important experimental factors and their levels. A regression model that considers the significant main and interaction effects was suggested. The results showed that initial dye concentration an pH is the most significant factor that affects the removal of malachite green.

Keywords: malachite green, adsorption, red mud, fly ash, full factorial design

Procedia PDF Downloads 478

Authors: Ratchanon Boonachathong, Bordin Kaewnok, Suksun Amornraksa

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Rigid polyurethane foam (RPUF) used for imitation wood is typically prepared by using 1-Dichloro-1-fluoroethane (HCFC-141b) as a blowing agent. However, this chemical is a hydrofluorocarbon which severely causes ozone depletion to the atmosphere. In this work, a more environmental-friendly RPUF was prepared by using distilled water and cyclopentane (CP) as alternative blowing agent. Several properties of the prepared RPUF were investigated and measured such as density (kg/m³), surface hardness (shore D), and glass transition temperature (°C). It was found that when the amount of the blowing agents decreased, the foam density is increased as well as the surface hardness and glass transition temperature. The results showed that the proper amount of water and cylopentane blowing agent is around 0.3–1.2% and 0.5-1.3% respectively. And the new RPUF produced has a good potential to substitute for a conventional RPUF.

Keywords: blowing agent, cyclopentane co-blown, imitation wood, rigid polyurethane foam, surface hardness

Procedia PDF Downloads 173

Authors: M. Mahdavi, M. Mohseni, R. Rafiei, H. Yari

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Environmental factors can deteriorate the automotive coatings significantly. Such as UV radiations, humidity, hot-cold shock and destructive chemical compounds. Furthermore, some natural materials such as bird droppings and tree gums have the potential to degrade the coatings as well. The present work aims to study the mechanism of degradation for two automotive refinish coating (PU based) systems exposed to two types of biological materials, i.e. Arabic gum and the simulated bird dropping, pancreatin. To reach this goal, effects of these biological materials on surface properties and appearance were studied using different techniques including digital camera, FT-IR spectroscopy, optical microscopy, and gloss measurements. In addition, the thermo-mechanical behavior of coatings was examined by DMTA. It was found that cross-linking had a crucial role on the biological resistance of clear coat. The higher cross-linking enhanced biological resistance.

Keywords: refinish clear coat, pancreatin, Arabic gum, cross-linking, biological degradation

Procedia PDF Downloads 369