Search results for: chemical solution

Authors: M. Rutkowski, J. Cwiklak, M. Grzegorzewski, M. Adamski

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All class A Airplanes have to be equipped with Mod. S transponder for ATC surveillance purposes. This technology was designed to provide a robust and dependable solution to localize, identify and exchange data with the airplane. The purpose of this paper is to analyze potential hazards that are a result of lack of any security or encryption on a design level. Secondary Surveillance Radars rely on an active response from an airplane. SSR radar installation is broadcasting a directional interrogation signal to the planes in range on 1030MHz frequency with DPSK modulation. If the interrogation is correctly received by the transponder located on the plane, a proper answer is sent on 1090MHz with PPM modulation containing plane’s SQUAWK, barometric altitude, GPS coordinates and 24bit unique address code. This technology does not use any kind of encryption. All of the specifications from the previous chapter can be found easily on the internet. Since there is no encryption or security measure to ensure the credibility of the sender and message, it is highly hazardous to use such technology to ensure the safety of the air traffic. The only thing that identifies the airplane is the 24-bit unique address. Most of the planes have been sniffed by aviation enthusiasts and cataloged in web databases. In the moment of writing this article, The PoFung Technologies has announced that they are planning to release all band SDR transceiver – this device would be more than enough to build your own Mod. S Transponder. With fake transponder, a potential terrorist can identify as a different airplane. By replacing the transponder in a poorly controlled airspace, hijackers can enter another airspace identifying themselves as another plane and land in the desired area.

Keywords: flight safety, hijack, mod S transponder, security analysis

Procedia PDF Downloads 282

Authors: Benjamin M Dauda, Esther Ibrahim, Sylvester Gadimoh, Asabe Mustapha, Jiyah Mohammed

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Despite diverse optimization techniques on natural hydrophilic fibers, hydrophobic synthetic fibers are still the best oil sorption materials. However, these hydrophobic fibers are not biodegradable, making their disposal problematic. To this end, this work sets out to develop Nonwoven sorbents from epoxy-coated Cotton fibers. As a way of improving the compatibility of the crude oil and reduction of moisture absorption, cotton fibers were coated with epoxy resin by immersion in acetone-thinned epoxy solution. A needle-punching machine was used to convert the fibers into coherent nonwoven sheets. An oil sorption experiment was then carried out. The result indicates that the developed epoxy-modified sorbent has a higher crude oil-sorption capacity compared with those of untreated cotton and commercial polypropylene sorbents. Absorption Curves show that the coated fiber and polypropylene sorbent saturated faster than the uncoated cotton fiber pad. The result also shows that the coated cotton sorbent adsorbed crude faster than the polypropylene sorbent, and the equilibrium exhaustion was also higher. After a simple mechanical squeezing process, the Nonwoven pads could be restored to their original form and repeatedly recycled for oil/water separation. The results indicate that the cotton-coated non-woven pads hold promise for the cleanup of oil spills. Our data suggests that the sorption behaviors of the epoxy-coated Nonwoven pads and their crude oil sorption capacity are relatively stable under various environmental conditions compared to the commercial sheet.

Keywords: oil spill, adsorption, cotton, epoxy, nonwoven

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Authors: Ying-Pin Chang

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This paper presents a method for combining a particle swarm optimization with nonlinear time-varying evolution and orthogonal arrays (PSO-NTVEOA) in the planning of harmonic filters for the high speed railway traction system with specially connected transformers in unbalanced three-phase power systems. The objective is to minimize the cost of the filter, the filters loss, the total harmonic distortion of currents and voltages at each bus simultaneously. An orthogonal array is first conducted to obtain the initial solution set. The set is then treated as the initial training sample. Next, the PSO-NTVEOA method parameters are determined by using matrix experiments with an orthogonal array, in which a minimal number of experiments would have an effect that approximates the full factorial experiments. This PSO-NTVEOA method is then applied to design optimal harmonic filters in Taiwan High Speed Rail (THSR) traction system, where both rectifiers and inverters with IGBT are used. From the results of the illustrative examples, the feasibility of the PSO-NTVEOA to design an optimal passive harmonic filter of THSR system is verified and the design approach can greatly reduce the harmonic distortion. Three design schemes are compared that V-V connection suppressing the 3rd order harmonic, and Scott and Le Blanc connection for the harmonic improvement is better than the V-V connection.

Keywords: harmonic filters, particle swarm optimization, nonlinear time-varying evolution, orthogonal arrays, specially connected transformers

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Authors: Ramesh Subramani, Mathivanan Narayanasamy, William Aalbersberg

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It is well accepted by last 35 years of research and on-going programmes that marine environment harbours abundant and unique biodiversity, which is currently playing as an important source in bioprospecting. It has become apparent that marine microorganisms are lead in the biodiscovery. Among marine organisms, actinobacteria are a target phylum for discovering novel antibiotics against increasing the multi-drug resistant human pathogens because of these taxa representing for novel genera and species. Marine actinomycetes are a proven source of new antibiotic leads and novel enzymes with important industrial applications. A total of 183 streptomycete and 25 non-streptomycete strains were isolated from different marine samples collected from north-eastern part of the Indian Ocean. Among them, 111 isolates displayed antibacterial activity against human pathogens and 151 exhibited antifungal activity against phytopathogens. Importantly, most of them produced various extracellular enzymes and 58 of them produced exopolysaccharides. Totally eight small bioactive compounds and a thermostable alkaline protease have been purified from a selected strain, Streptomyces fungicidicus. Besides, our on-going studies on non-streptomycete strains (rare actinomycetes) are most likely promising resource for new and unique compounds against current emerging drug-resistant pathogens. We have just recognised the chemical diversity in marine microorganisms. Therefore it is worthwhile to continue the exploration of marine microorganisms for new drug leads, novel enzymes and other bioprospecting research.

Keywords: bioactive compounds, industrial enzymes, marine actinobacteria, microbial metabolites, marine natural products

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Authors: Stephen O. Amiandamhen, Martina Meinken, Luvuyo Tyhoda

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The properties of Hemp (Cannabis sativa) in phosphate bonded composites were investigated in this research. Hemp hurds were collected from the Hemporium institute for research, South Africa. The hurds were air-dried and shredded using a hammer mill. The shives were screened into different particle sizes and were treated separately with 5% solution of acetic anhydride and sodium hydroxide. The binding matrix was prepared using a reactive magnesia, phosphoric acid, class S fly ash and unslaked lime. The treated and untreated hemp fibers were mixed thoroughly in different ratios with the inorganic matrix. Boric acid and excess water were used to retard and control the rate of the reaction and the setting of the binder. The Hemp composite was formed in a rectangular mold and compressed at room temperature at a pressure of 100KPa. After de-molding the composites, they were cured in a conditioning room for 96 h. Physical and mechanical tests were conducted to evaluate the properties of the composites. A central composite design (CCD) was used to determine the best conditions to optimize the performance of the composites. Thereafter, these combinations were applied in the production of the composites, and the properties were evaluated. Scanning electron microscopy (SEM) was used to carry out the advance examination of the behavior of the composites while X-ray diffractometry (XRD) was used to analyze the reaction pathway in the composites. The results revealed that all properties of phosphate bonded Hemp composites exceeded the LD-1 grade classification of particle boards. The proposed product can be used for ceiling, partitioning, wall claddings and underlayment.

Keywords: CCD, fly ash, magnesia, phosphate bonded hemp composites, phosphoric acid, unslaked lime

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Authors: Najafi S., Heidai R., Jamei R., Tofigh F.

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In order to study the effects of magnetic field on the root system and growth of Phaseolus vulgaris, an experiment was conducted in 2012. The possible involvement of magnetic field (MF) pretreatment in physiological factors of Phaseolus vulgaris was investigated. Seeds were subjected to 10 days with 1.8 mT of magnetic field for 1h per day. MF pretreatment decreased the plant height, fresh and dry weight, length of root and length of shoot, Chlorophyll a, Chlorophyll b and carotenoid in 10 days old seedling. In addition, activity of enzymes such as Catalase and Guaiacol peroxidase was decreased due to MF exposure. Also, the total Protein and DPPH content of the treated by magnetic field was not significantly changed in compare to control groups, while the flavonoid, Phenol and prolin content of the treated of the treated by magnetic field was significantly changed in compare to control groups. Lateral branches of roots and secondary roots increased with MF. The results suggest that pretreatment of this MF plays important roles in changes in crop productivity. In all cases there was observed a slight stimulating effect of the factors examined. The growth dynamics were weakened. The plants were shorter. Moreover, the effect of a magnetic field on the crop of Phaseolus vulgaris and its structure was small.

Keywords: carotenoid, Chlorophyll a, Chlorophyll b, DPPH, enzymes, flavonoid, germination, growth, phenol, proline, protein, magnetic field, phaseolus vulgaris

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Authors: Pedro A. S. Bergamo, Emilia S. Streng, Jan Rosenkranz, Yousef Ghorbani

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Within the often-hazardous mineral industry, simulation training has speedily gained appreciation as an important method of increasing site safety and productivity through enhanced operator skill and knowledge. Performance calculations related to froth flotation, one of the most important concentration methods, is probably the hardest topic taught during the training of plant operators. Currently, most training teach those skills by traditional methods like slide presentations and hand-written exercises with a heavy focus on memorization. To optimize certain aspects of these pieces of training, we developed “MinFloat”, which teaches the operation formulas of the froth flotation process with the help of gamification. The simulation core based on a first-principles flotation model was implemented in Unity3D and an instructor tutoring system was developed, which presents didactic content and reviews the selected answers. The game was tested by 25 professionals with extensive experience in the mining industry based on a questionnaire formulated for training evaluations. According to their feedback, the game scored well in terms of quality, didactic efficacy and inspiring character. The feedback of the testers on the main target audience and the outlook of the mentioned solution is presented. This paper aims to provide technical background on the construction of educational games for the mining industry besides showing how feedback from experts can more efficiently be gathered thanks to new technologies such as online forms.

Keywords: training evaluation, simulation based training, modelling, and simulation, froth flotation

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Authors: Eugenia P. Ramirez, Kevin Matthe Caramancion, Mia Eleazar

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Getting the attention of students is a constant challenge to the instructors/lecturers. Although in the computer laboratories some networking and entertainment websites are blocked, yet, these websites have unlimited ways of attracting students to get into it. Thus, when an instructor gives a specific set of instructions, some students may not be able to follow sequentially the steps that are given. The instructor has to physically go to the specific remote terminal and show the student the details. Sometimes, during an examination in laboratory set-up, a proctor may prefer to give detailed and text-written instructions rather than verbal instructions. Even the mere calling of a specific student at any time will distract the whole class especially when activities are being performed. What is needed is : An application software that is able to lock the student's monitor and at the same time display the instructor’s screen; a software that is powerful enough to process in its side alone and manipulate a specific user’s terminal in terms of free configuration that is, without restrictions at the server level is a required functionality for a modern and optimal server structure; a software that is able to send text messages to students, per terminal or in group will be a solution. These features are found in LabSupport. This paper outlines the LabSupport application software framework to efficiently manage computer laboratory sessions and will include different modules: screen viewer, demonstration mode, monitor locking system, text messaging, and class management. This paper's ultimate aim is to provide a system that increases instructor productivity.

Keywords: application software, broadcast messaging, class management, locking system

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Authors: Eslam Dabbish, Fortuna Ponte, Stefano Scoditti, Emilia Sicilia, Gloria Mazzone

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The medical techniques based on the use of light for activating the drug are occupying a prominent place in the cancer treatment due to their selectivity that contributes to reduce undesirable side effects of conventional chemotherapy. Among these therapeutic treatments, photodynamic therapy (PDT) and photoactivated chemotherapy (PACT) are emerging as complementary approaches for selective destruction of neoplastic tissue through direct cellular damage. Both techniques rely on the employment of a molecule, photosensitizer (PS), able to absorb within the so-called therapeutic window. Thus, the exposure to light of otherwise inert molecules promotes the population of excited states of the drug, that in PDT are able to produce the cytotoxic species, such as 1O2 and other ROS, in PACT can be responsible of the active species release or formation. Following the success of cisplatin in conventional treatments, many other transition metal complexes were explored as anticancer agents for applications in different medical approaches, including PDT and PACT, in order to improve their chemical, biological and photophysical properties. In this field, several crucial characteristics of candidate PSs can be accurately predicted from first principle calculations, especially in the framework of density functional theory and its time-dependent formulation, contributing to the understanding of the entire photochemical pathways involved which can ultimately help in improving the efficiency of a drug. A brief overview of the outcomes on some platinum and ruthenium-based PSs proposed for the application in the two phototherapies will be provided.

Keywords: TDDFT, metal complexes, PACT, PDT

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Authors: Srinivasapriyan Vijayan

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Phenol is one of the most vital chemical in industry. Nowadays, phenol production is based upon the three-step cumene process, which involves a hazardous cumene hydroperoxide intermediate and produces nearly equimolar amounts of acetone as a coproduct. An attractive route in phenol production is the direct one-step selective hydroxylation of benzene using eco-friendly oxidants such as O2, N2O, and H2O2. In particular, the direct hydroxylation of benzene to form phenol with O2 has recently attracted extensive research attention because this process is green clean and eco-friendly. However, most of the catalytic systems involving O2 have a low rate of hydroxylation because the direct introduction of hydroxyl functionality into benzene is challenging. Almost all the developed catalytic systems require an elevated temperature and suffer from low conversion because of the notoriously low reactivity of aromatic C–H bonds. Moreover, increased reactivity of phenol relative to benzene makes the selective oxidation of benzene to phenol very difficult, especially under heating conditions. Hollow spheres, a very fascinating class of materials with good permeation and low density, highly monodisperse MOF hollow sandwich spheres have been rationally synthesized using monodisperse polystyrene (PS) nanoparticles as templates through a versatile step-by-step self-assembly strategy. So, our findings could pave the way toward highly efficient nonprecious catalysts for low-temperature oxidation reactions in heterogeneous catalysis. Because it is easy post-reaction separation, its cheap, green and recyclable.

Keywords: benzene hydroxylation, Fe-based metal organic frameworks, molecular oxygen, phenol

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Authors: Alexander Rodríguez-Hernández, Arnulfo Rojas-Perez, Liz Diaz-Vazquez

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The rise in consumerism over the past century has resulted in the creation of higher amounts of plasticizers, personal care products and other chemical substances, which enter and accumulate in water systems. Other sources of pollutants in Neotropical regions experience large inputs of nutrients with these pollutants resulting in eutrophication of water which consume large quantities of oxygen, resulting in high fish mortality. This dilemma has created a need for the development of targeted detection in complex matrices and remediation of emerging contaminants. We have synthesized carbon nanoparticles from macro algae (Ulva fasciata) by oxidizing the graphitic carbon network under extreme acidic conditions. The resulting material was characterized by STEM, yielding a spherical 12 nm average diameter nanoparticles, which can be fixed into a polysaccharide aerogel synthesized from the same macro algae. Spectrophotometer analyses show a pH dependent fluorescent behavior varying from 450-620 nm in aqueous media. Heavily oxidized edges provide for easy functionalization with enzymes for a more targeted analysis and remediation technique. Given the optical properties of the carbon base nanoparticles and the numerous possibilities of functionalization, we have developed a selective and robust targeted bio-detection and bioremediation technique for the treatment of emerging contaminants in complex matrices like estuarine embayment.

Keywords: aerogels, carbon nanoparticles, fluorescent, targeted analysis

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Authors: K. S. Hemant Yadav, H. G. Shivakumar

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The present study investigation was to prepare and evaluate the mucoadhesive multi-particulate system for nasal drug delivery of anti-histaminic drug. Ebastine was chosen as the model drug. Drug loaded nanoparticles of Ebastine were prepared by ionic gelation method using chitosan as polymer using the drug-polymer weight ratios 1:1, 1:2, 1:3. Sodium tripolyphosphate (STPP) was used as the cross-linking agent in the range of 0.5 and 0.7% w/v. FTIR and DSC studies indicated that no chemical interaction occurred between the drug and polymers. Particle size ranged from 169 to 500 nm. The drug loading and entrapment efficiency was found to increase with increase in chitosan concentration and decreased with increase in poloxamer 407 concentration. The results of in vitro mucoadhesion carried out showed that all the prepared formulation had good mucoadhesive property and mucoadhesion increases with increase in the concentration of chitosan. The in vitro release pattern of all the formulations was observed to be in a biphasic manner characterized by slight burst effect followed by a slow release. By the end of 8 hrs, formulation F6 showed a release of only 86.9% which explains its sustained behaviour. The ex-vivo permeation of the pure drug ebastine was rapid than the optimized formulation(F6) indicating the capability of the chitosan polymer to control drug permeation rate through the sheep nasal mucosa. The results indicated that the mucoadhesive nanoparticulate system can be used for the nasal delivery of antihistaminic drugs in an effective manner.

Keywords: nasal, nanoparticles, ebastine, anti-histaminic drug, mucoadhesive multi-particulate system

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Authors: Sajad Haghanifar, Seyed-Farshid Kashani Bozorg

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Nano-crystalline Mg2Ni-based powder was produced by mechanical alloying technique using binary and ternary powder mixtures with stoichiometric compositions of Mg2Ni, Mg1.9C0.1Ni and Mg2C0.1Ni0.9. The structures and morphologies of the milled products were studied by XRD, SEM and HRTEM. Their electrochemical hydrogen storage characteristics were investigated in 6 M KOH solution. X-Ray diffraction, scanning and transmission electron microscopy of the milled products showed the formation of Mg2Ni-based nano-crystallites after 5, 15 and 30 h of milling using the initial powder mixtures of Mg1.9C0.1Ni, Mg2Ni and Mg2C0.1Ni0.9, respectively. It was found that partial substitution of C for Mg has beneficial effect on the formation kinetic of nano-crystalline Mg2Ni. Contrary to this, partial substitution of C for Ni was resulted in retardation of formation kinetic of nano-crystalline Mg2Ni. In addition, the negative electrode made from Mg1.9C0.1Ni ternary milled product after 30 hour of milling exhibited the highest initial discharge capacity and longest discharge life. Thus, partial substitution of C for Mg is beneficial to electrode properties of the Mg2Ni-based crystallites. The relation between the discharge capacity and cycling number of mechanically alloyed products was proposed on the basis of the fact that the degradation of discharge capacity was mainly caused by the oxidation of magnesium and nickel. The experimental data fitted the deduced equation well.

Keywords: Mg2Ni, hydrogen absorbing materials, electrochemical properties, nano-crystalline, amorphous, mechanical alloying, carbon

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Authors: Sudha Shukla, Bablu Kumar, Gyan Prakash Gupta, U. C. Kulshrestha

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Air pollutants emitted from solid biofuels during cooking are the major contributors to poor air quality, respiratory problems, and radiative forcing, etc. in rural areas of most of developing countries. The present study reports the chemical characteristics and sources of ambient aerosols and traces gases during cooking and non-cooking hours emitted during biofuel combustion in a village in North-Central India. Fine aerosol samples along with gaseous species (Sox, NOx, and NH₃) were collected during September 2010-March 2011 at Khairatpur village (KPV) which is located in the Uttar Pradesh state in North-Central India. Results indicated that most of the major ions in aerosols and Sox, NOx, and NH₃ gases were found to be higher during cooking hours as compared to non-cooking hours suggesting that solid biofuel combustion is an important source of air pollution. Results of Principal Component Analysis (PCA) revealed that combustion of solid biofuel, vehicular emissions, and brick kilns were the major sources of fine aerosols and trace gases in the village. A health survey was conducted to find out the relation between users of biofuels and their health effects and the results revealed that most of the women in the village were suffering from diseases associated with biofuel combustion during cooking.

Keywords: ambient aerosols, biofuel combustion, cooking, health survey, rural area

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Authors: Mazyar Ahrari, Ramin Khajavi, Mehdi Kamali Dolatabadi, Tayebeh Toliyat, Abosaeed Rashidi

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Fabric as the first and most common layer that is in permanent contact with human skin is a very good interface to provide coverage, as well as heat and cold insulation. Phase change materials (PCMs) are organic and inorganic compounds which have the capability of absorbing and releasing noticeable amounts of latent heat during phase transitions between solid and liquid phases at a low temperature range. PCMs come across phase changes (liquid-solid and solid-liquid transitions) during absorbing and releasing thermal heat; so, in order to use them for a long time, they should have been encapsulated in polymeric shells, so-called microcapsules. Microencapsulation and nanoencapsulation methods have been developed in order to reduce the reactivity of a PCM with outside environment, promoting the ease of handling, decreasing the diffusion and evaporation rates. Methods of incorporation of PCMs in textiles such as electrospinning and determining thermal properties had been summarized. Paraffin waxes catch a lot of attention due to their high thermal storage density, repeatability of phase change, thermal stability, small volume change during phase transition, chemical stability, non-toxicity, non-flammability, non-corrosive and low cost and they seem to play a key role in confronting with climate change and global warming. In this article, we aimed to review the researches concentrating on the characteristics of PCMs and new materials and methods of microencapsulation.

Keywords: thermoregulation, microencapsulation, phase change materials, thermal energy storage, nanoencapsulation

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Authors: Zainab Abbas Soharwardi, Chunli Su, Fazeelat Tahira, Syed Zahid Aziz

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The study monitors the quality of drinking water consumed by urban population of Lahore. A total of 50 drinking water samples (16 from source and 34 from distribution system) were examined for physical, chemical and bacteriological parameters. The parameters including pH, turbidity, electrical conductivity, total dissolved solids, total hardness, calcium, magnesium, total alkalinity, carbonate, sulphate, chloride, nitrite, fluoride, sodium and potassium were analyzed. Sixteen out of fifty samples showed high values of alkalinity compared to EPA standards and WHO guidelines. Twenty-eight samples were analyzed for heavy metals, chromium, iron, copper, zinc, cadmium and lead. Trace amounts of heavy metals were detected in some samples, however for most of the samples values were within the permissible limits although high concentration of zinc was detected in one sample collected from Mughal Pura area. Fifteen samples were analyzed for arsenic. The results were unsatisfactory; around 73% samples showed exceeding values of As. WHO has suggested permissible limits of arsenic < 0.01 ppm, whereas 27 % of samples have shown 0.05 ppm arsenic, which is five times greater than WHO highest permissible limits. All the samples were examined for E. coli bacteria. On the basis of bacteriological analysis, 42 % samples did not meet WHO guidelines and were unsafe for drinking.

Keywords: arsenic, heavy metals, ground water, Lahore

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Authors: Eleni Tsalaporta, Sebastien Vaesen, James M. D. MacElroy, Wolfgang Schmitt

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Carbon dioxide capture has attracted the attention of many governments, industries and scientists over the last few decades, due to the rapid increase in atmospheric CO2 composition, with several studies being conducted in this area over the last few years. In many of these studies, CO2 capture in complex Pressure Swing Adsorption (PSA) cycles has been associated with high energy consumption despite the promising capture performance of such processes. The purpose of this study is the economic capture of atmospheric carbon dioxide for its transformation into a clean type of energy. A single column Temperature /Vacuum Swing Adsorption (TSA/VSA) process is proposed as an alternative option to multi column Pressure Swing Adsorption (PSA) processes. The proposed adsorbent is SIFSIX-3-Ni, a newly developed MOF (Metal Organic Framework), with extended CO2 selectivity and capacity. There are three stages involved in this paper: (i) SIFSIX-3-Ni is synthesized and pelletized and its physical and chemical properties are examined before and after the pelletization process, (ii) experiments are designed and undertaken for the estimation of the diffusion and adsorption parameters and limitations for CO2 undergoing capture from the air; and (iii) the CO2 adsorption capacity and dynamical characteristics of SIFSIX-3-Ni are investigated both experimentally and mathematically by employing a single column TSA/VSA, for the capture of atmospheric CO2. This work is further supported by a technical-economical study for the estimation of the investment cost and the energy consumption of the single column TSA/VSA process. The simulations are performed using gProms.

Keywords: carbon dioxide capture, temperature/vacuum swing adsorption, metal organic frameworks, SIFSIX-3-Ni

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Authors: Abdallah Bouguettoucha, Derradji Chebli, Tariq Yahyaoui, Hichem Attout

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The effect of acid -basic treatment of lingocellulosic material (forest wastes wild carob) on Ethyl violet adsorption was investigated. It was found that surface chemistry plays an important role in Ethyl violet (EV) adsorption. HCl treatment produces more active acidic surface groups such as carboxylic and lactone, resulting in an increase in the adsorption of EV dye. The adsorption efficiency was higher for treated of lingocellulosic material with HCl than for treated with KOH. Maximum biosorption capacity was 170 and 130 mg/g, for treated of lingocellulosic material with HCl than for treated with KOH at pH 6 respectively. It was also found that the time to reach equilibrium takes less than 25 min for both treated materials. The adsorption of basic dye (i.e., ethyl violet or basic violet 4) was carried out by varying some process parameters, such as initial concentration, pH and temperature. The adsorption process can be well described by means of a pseudo-second-order reaction model showing that boundary layer resistance was not the rate-limiting step, as confirmed by intraparticle diffusion since the linear plot of Qt versus t^0.5 did not pass through the origin. In addition, experimental data were accurately expressed by the Sips equation if compared with the Langmuir and Freundlich isotherms. The values of ΔG° and ΔH° confirmed that the adsorption of EV on acid-basic treated forest wast wild carob was spontaneous and endothermic in nature. The positive values of ΔS° suggested an irregular increase of the randomness at the treated lingocellulosic material -solution interface during the adsorption process.

Keywords: adsorption, isotherm models, thermodynamic parameters, wild carob

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Authors: Kimmo J. Kurppa

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This paper describes the development of the buyer-supplier dyad concept over the years and proposes improvements, clarifications and extensions to the prevailing definitions published in 1970’s and 1980’s. This paper suggests a partition of the buyer-supplier dyad to concepts of Commercial Dyad (dyadic interaction in vertical relationships) and Innovative Dyad (dyadic interaction in horizontal relationship) since dyadic interaction takes place in two major types of contexts between industrial firms. Especially the context of joint product development in a dyadic relationship has not been adequately recognized being totally different from the interaction taking place in commercial buyer-supplier interaction. This paper provides therefore a solution to the existing gap in research by clarifying the descriptions and the context where dyadic interaction takes place between industrial firms. This paper also illustrates and explains how the firm’s organization and the interaction taking place inside it, is connected to the dyadic interaction structure between the firm and its partner firm. This theme has been discussed earlier but the phenomenon has not been adequately described and has not been illustrated in earlier research. This conceptual study has been interested in how the dyad concept of Industrial Marketing has been defined in the earlier research and how the definition could be improved. This conceptual paper has been constructed by using the systematic review methodology and proposes avenues for future research. The concept and existence of relationship and interaction between firm’s internal interaction network and external interaction between firm’s dyadic counterparts, need to be verified through empirical research.

Keywords: dyadic interaction, industrial dyad, buyer-supplier relationship, strategic reciprocity, experience, socially adjusted opportunism

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Authors: Funmilayo L. Amao, Amos O. Amao

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It has been observed that majority of the people are living in poor housing quality or totally homeless in urban center despite all governmental policies to provide housing to the public. On the supply side, various government policies in the past have been formulated towards overcoming the huge shortage through several Housing Reform Programmes. Despite these past efforts, housing continues to be a mirage to ordinary Nigerian. Currently, there are various mass housing delivery programmes such as the affordable housing scheme that utilize the Public Private Partnership effort and several Private Finance Initiative models could only provide for about 3% of the required stock. This suggests the need for a holistic solution in approaching the problem. The aim of this research is to find out the problems hindering the delivery of housing in Nigeria and its effects on housing affordability. The specific objectives are to identify the causes of housing delivery problems, to examine different housing policies over years and to suggest a way out for sustainable housing delivery. This paper also reviews the past and current housing delivery programmes in Nigeria and analyses the demand and supply side issues. It identifies the various housing delivery mechanisms in current practice. The objective of this paper, therefore, is to give you an insight into the delivery option for the sustainability of housing in Nigeria, given the existing delivery structures and the framework specified in the New National Housing Policy. The secondary data were obtained from books, journals and seminar papers. The conclusion is that we cannot copy models from other nations, but should rather evolve workable models based on our socio-cultural background to address the huge housing shortage in Nigeria. Recommendations are made in this regard.

Keywords: housing, sustainability, housing delivery, housing policy, housing affordability

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Authors: Li Ji, Kaiwei Chu, Shibo Kuang, Aibing Yu

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Hydrocyclones are widely used to classify particles by size in industries such as mineral processing and chemical processing. The particles to be handled usually have a broad range of size distributions and sometimes density distributions, which has to be properly considered, causing challenges in the modelling of hydrocyclone. The combined approach of Computational Fluid Dynamics (CFD) and Discrete Element Method (DEM) offers convenience to model particle size/density distribution. However, its direct application to hydrocyclones is computationally prohibitive because there are billions of particles involved. In this work, a CFD-DEM model with the concept of the coarse-grained (CG) model is developed to model the solid-fluid flow in a hydrocyclone. The DEM is used to model the motion of discrete particles by applying Newton’s laws of motion. Here, a particle assembly containing a certain number of particles with same properties is treated as one CG particle. The CFD is used to model the liquid flow by numerically solving the local-averaged Navier-Stokes equations facilitated with the Volume of Fluid (VOF) model to capture air-core. The results are analyzed in terms of fluid and solid flow structures, and particle-fluid, particle-particle and particle-wall interaction forces. Furthermore, the calculated separation performance is compared with the measurements. The results obtained from the present study indicate that this approach can offer an alternative way to examine the flow and performance of hydrocyclones

Keywords: computational fluid dynamics, discrete element method, hydrocyclone, multiphase flow

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Authors: Nastaran Rezaei, Mohammad Saeed Mossadegh, Farhan Kocheyli, Khalil Talebi Jahromi, Aurang Kavousi

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Integrated Pest Management (IPM) aims to combine biological and chemical strategies and measures, hence highlighting the study of acute toxicity and sub-lethal effects of pesticides comprehensively. The present research focused on the side effects of thiamethoxam and pirimicarb sub-lethal concentrations on demographic parameters of Diaeretiella rapae (McIntosh Laboratory) (Hymenoptera: Braconidae). Adult parasitoids were exposed to LC₂₅ of insecticides as well as distilled water as the control. The results showed that thiamethoxam adversely affected population parameters (r, λ, R₀, T), adults' longevity, females' oviposition period and mean fecundity, and a similar trend was obtained for pirimicarb with the exception of generation time (T), the latter did not significantly change compared to the control. The intrinsic rate of increase (r) in the control and those treated with pirimicarb and thiamethoxam were 0.2801, 0.2064, 0.1525 days^-1, respectively, and the sex ratio was biased toward females in all treatments. Furthermore, none of the insecticides influenced total pre-oviposition period (TPOP) and offspring emergence rate. In general, these results indicated that both insecticides potentially distort the demographic parameters of the parasitoid even at sub-lethal concentrations, and then they should not be considered for IPM program in the presence of D. rapae.

Keywords: Diaeretiella rapae, Lipaphis erysimi, life-table study, pirimicarb, thiamethoxam

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Authors: D. J. Kalita

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Cancer is one of the prime causes of early death worldwide. Mutation of the gene involve in DNA repair and damage, like BRCA2 (Breast cancer gene two) genes, can be detected efficiently by PCR-RFLP to early breast cancer diagnosis and adopt the suitable method of treatment. Host Defense Peptide can be used as blueprint for the design and synthesis of novel anticancer drugs to avoid the side effect of conventional chemotherapy and chemo resistance. The change at nucleotide position 392 of a -› c in the cancer sample of dog mammary tumour at BRCA2 (exon 7) gene lead the creation of a new restriction site for SsiI restriction enzyme. This SNP may be a marker for detection of canine mammary tumour. Support vector machine (SVM) algorithm was used to design and predict the anticancer peptide from the mature functional peptide. MTT assay of MCF-7 cell line after 48 hours of post treatment showed an increase in the number of rounded cells when compared with untreated control cells. The ability of the synthesized peptide to induce apoptosis in MCF-7 cells was further investigated by staining the cells with the fluorescent dye Hoechst stain solution, which allows the evaluation of the nuclear morphology. Numerous cells with dense, pyknotic nuclei (the brighter fluorescence) were observed in treated but not in control MCF-7 cells when viewed using an inverted phase-contrast microscope. Thus, PCR-RFLP is one of the attractive approach for early diagnosis, and synthetic cationic peptide can be used for the treatment of canine mammary tumour.

Keywords: cancer, cationic peptide, host defense peptides, Breast cancer genes

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Authors: Zelin Zhou, Timothy Langrish

Abstract:

Spray drying is the final stage of milk powder production. Traditionally, the quality of spray-dried milk powders has mainly been assessed using their physical properties, such as their moisture contents, while chemical changes occurring during the spray drying process have often been ignored. With growing concerns about food quality, it is necessary to establish a better understanding of heat-induced degradation due to the spray-drying process of skim milk. In this study, the extent of thermal degradation for skim milk in a pilot-scale spray dryer has been investigated using different inlet gas temperatures. The extent of heat-induced damage has been measured by the formation of advanced Maillard reaction products and the loss of soluble proteins at pH 4.6 as assessed by a fluorometric method. A significant increase in the extent of thermal degradation has been found when the inlet gas temperature increased from 170°C to 190°C, suggesting protein unfolding may play an important role in the kinetics of heat-induced degradation for milk in spray dryers. Colour changes of the spray-dried skim milk powders have also been analysed using a standard lighting box. Colourimetric analysis results were expressed in CIELAB colour space with the use of the E index (E) and the Chroma (C) for measuring the difference between colours and the intensity of the colours. A strong linear correlation between the colour intensity of the spray-dried skim milk powders and the formation of advanced Maillard reaction products has been observed.

Keywords: colour formation, Maillard reactions, spray drying, skim milk powder

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Authors: Asli Beyler Çi̇ği̇l, Memet Vezi̇r Kahraman

Abstract:

Organic–inorganic hybrids have become an effective source of advanced materials because they combine the advantages of both the organic moiety such as flexibility, low dielectric constant, and processability, and inorganic moiety as rigidity, strength, durability, and thermal stability. By incorporating cross-linkable side chains, the hybrid materials can be made photosensitive and UV curable, which offers many advantages including low processing temperature, low equipment cost and compatibility. In this study, uv-curable organic-inorganic hybrid material, which was contained surface modified polyaniline particles (PANI), was prepared. PANI surface photografted with hydroxy ethyl methacrylate (HEMA) to produce hydroxyl groups. Hydroxyl functionalized PANI/HEMA was acrylated using isocyanato ethyl methacrylate (IEM) in order to improve the dispersion and interfacial interaction in composites. UV-curable formulation was prepared by mixing the surface modified PANI, polyethylene glycol diacrylate (PEGDA), trimethylolpropane triacrylate (TMPTA), hydrolized 3- methacryloxypropyltrimethoxysilane (hyd. MEMO) and photoinitiator. Chemical structure of nano-hybrid material was characterized by FTIR. FTIR spectra showed that the photografting of PANI was prepared successfully. Thermal properties of the nano-hybrid material were determined by thermogravimetric analysis (TGA). The morphology of the nano-hybrid material was performed by scanning electron microscopy (SEM).

Keywords: polyaniline, photograft, sol-gel, uv-curable polymer

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Authors: Mohamed Eltarabily, Abdelazim Negm, Chihiro Yoshimura

Abstract:

Recently, the pollution of groundwater from the use of nitrogenous fertilizer is at the increase. Also, due to the increase in area under cultivation and regular use of fertilizer in irrigated agriculture, groundwater pollution from agricultural activities is becoming a major concern. Because of the high mobility of Nitrate (NO3-) in soil which is governed by electrostatic processes, particularly anion exclusion, nitrate can be intercepted by shallow subsurface drainage pipe systems and then discharged offsite into streams, rivers, and lakes causing many hazards. In order to solve these environmental problems associated with nitrate, a better understanding of how NO3- moves through the soil profile under flow conditions is required. In the present paper, the results of a comparative study between experimental and numerical modeling of Nitrate transport through a saturated soil column are presented and analyzed. In order to achieve that, three water fluxes densities; 0.008, 0.007, and 0.006 m sec-1 and N concentration rates 10 mol cm-3 were used. The same concentrations were used in the simulation using HYDRUS-2D. The physical and chemical properties of the collected soil samples were calculated. Besides, the soil texture was determined which was silty sand. Results showed that HYDRUS-2D can successfully predict the relative behavior of N transport in the present experiment. Nitrate concentrations will reach deeper depth with the increase in the water flux. Overall, it was overestimated in the final concentration of (NO3-) in the soil by numerical simulation than by experimental column test. The column experiment is a useful tool for assessing the nitrate concentrations in the soil profile.

Keywords: groundwater, nitrate leaching, HYDRUS-2D, soil column

Procedia PDF Downloads 221

Authors: Sarre Nzaba, Bulelwa Ntsendwana, Bekkie Mamba, Alex Kuvarega

Abstract:

Elimination of toxic organic compounds from wastewater is currently one of the most important subjects in water pollution control. The discharge of azo dyes such as Brilliant black (BB) into the water bodies has carcinogenic and mutagenic effects on humankind and the ecosystem. Conventional water treatment techniques fail to degrade these dyes completely thereby posing more problems. Advanced oxidation processes (AOPs) are promising technologies in solving the problem. Anatase type nitrogen-platinum (N,Pt) co-doped TiO₂ photocatalyts were prepared by a modified sol-gel method using amine terminated polyamidoamine generation 1 (PG1) as a template and source of nitrogen. SEM/ EDX, TEM, XRD, XPS, TGA, FTIR, RS, PL and UV-Vis were used to characterize the prepared nanomaterials. The synthesized photocatalysts exhibited lower band gap energies as compared to the commercial TiO₂ revealing a shift in band gap towards the visible light absorption region. Photocatalytic activity of N,Pt co-doped TiO₂ was measured by the reaction of photocatalytic degradation of BB dye. Enhanced photodegradation efficiency of BB was achieved after 180 min reaction time with initial concentration of 50 ppm BB solution. This was attributed to the rod-like shape of the materials, larger surface area, and enhanced absorption of visible light induced by N,Pt co-doping. The co-doped N,Pt also exhibited pseudo-first order kinetic behaviour with half-life and rate constant of 0.37 min 0.1984 min⁻¹ and respectively. N doped TiO₂ and N,Pt co-doped TiO₂ exhibited enhanced photocatalytic performances for the removal of BB from water.

Keywords: N, Pt co-doped TiO₂, dendrimer, photodegradation, visible-light

Procedia PDF Downloads 156

Authors: Mohamed Loutou, Mohamed Hajjaji, Mohamed Ait Babram, Mohammed Mansori, Rachid Hakkou, Claude Favotto

Abstract:

More than 26,4 million tons of phosphates are produced by the phosphates industries in Morocco (2010), generating huge amounts of sludge by flocculation during the ore beneficiation. They way are stored at the end of the process in open air ponds. Its accumulation and storage may have an impact on several scales such as ground water and human being. For this purpose, an efficient way to use it the field of the ceramic is proposed. The as received sludge and a clay-rich sediment have been studied in terms of chemical, mineralogical and micro-structural side using various analytical methods. Several formulations have been performed by mixing the sludge with the binder shaped in the form of granules. After being dried at 105 °C, the samples were heated in the range of 900-1200 °C. As well as the ceramic properties (firing shrinkage, water absorption, total porosity and compressive strength) the micro structure has been investigated using X-ray diffraction, scanning electron microscopy and Fourier transform infrared spectroscopy. The relations between properties and the operating factors were formulated using the design of experiments (DOE). Gehlenite was the only phase neo-formed in the sintering samples. SEM micrographs revealed the presence of nano metric stains. Based on RSM results, all factors had positive effects on Firing shrinkage, compressive strength and total porosity. However, they manifested opposite effects on density and water absorption.

Keywords: phosphate sludge, clay, ceramic properties, granule

Procedia PDF Downloads 494

Authors: Aloysius Colman Chukwuemeka Ezeabasili, Chibuike Patrick Ezeabasili

Abstract:

Medium Sized Construction Companies in Nigeria are those employing 50-250 workers that are mostly involved in roads, Commercial and domestic building Construction, among others. These companies are in the majority and contribute immensely to infrastructural development in Nigeria. Despite the last eight years of economic downturn and the past years of COVID-19 pandemic, signs of these Companies recovering from the economic recession and pandemic seem bright. Nigeria has recorded 213,000 confirmed cases 3968 deaths from COVID-19 as at now. These medium sized companies are currently trying to explore various opportunities to grow their businesses to achieve competitive advantages over others by studying and improving on their bidding efficiency, Strategies for selecting businesses, bidding markup Strategies, and cash flow. These strategies were studied through the recruitment of construction experts and professionals. Many of them have acquired new technologies that have impacted positively on their strategies. The impact of these technologies like the BIM, e-tendering, conditions of contract, and claim management strategies are advantages to them and has given them good advantages over their peers. Monte Carlo solution, Swot analysis, and average bid methods have also clearly added advantages to bidding practices. New and existing strategies are Scrutinized, and training of young Nigerians in advanced countries to acquire knowledge in best practices have elevated some of these companies. The Covid-19 has not been very harsh to Nigeria, and the country is surely not as devastated as the advanced countries. Nigeria has therefore been able to cope with the combination of the downturn and the pandemic.

Keywords: medium sized construction companies, competitive advantage, new bidding technologies, Nigeria

Procedia PDF Downloads 122

Authors: R. Ziaie Moayed, S. P. Emadoleslami Oskoei, S. D. Beladi Mousavi, A. Taleb Beydokhti

Abstract:

There have been many reports of the destructive effects of cement on the environment in recent years. In the present research, it has been attempted to reduce the destructive effects of cement by replacing silica fume as adhesive materials instead of cement. The present study has attempted to improve the mechanical properties of cement slurry by using waste material from a glass production factory, located in Qazvin city of Iran, in which accumulation volume has become an environmental threat. The chemical analysis of the waste material indicates that this material contains about 94% of SiO₂ and AL₂O₃ and has a close structure to silica fume. Also, the particle grain size test was performed on the mentioned waste. Then, the unconfined compressive strength test of the slurry was performed by preparing a mixture of water and adhesives with different percentages of cement and silica fume. The water to an adhesive ratio of this mixture is 1:3, and the curing process last 28 days. It was found that the sample had an unconfined compressive strength of about 300 kg/cm² in a mixture with equal proportions of cement and silica fume. Besides, the sample had a brittle fracture in the slurry sample made of pure cement, however, the fracture in cement-silica fume slurry mixture is flexible and the structure of the specimen remains coherent after fracture. Therefore, considering the flexibility that is achieved by replacing this waste, it can be used to stabilize soils with cracking potential.

Keywords: cement replacement, cement slurry, environmental threat, natural pozzolan, silica fume, waste material

Procedia PDF Downloads 118