Search results for: heavy metal toxicity
596 A Hedonic Valuation Approach to Valuing Combined Sewer Overflow Reductions
Authors: Matt S. Van Deren, Michael Papenfus
Abstract:
Seattle is one of the hundreds of cities in the United States that relies on a combined sewer system to collect and convey municipal wastewater. By design, these systems convey all wastewater, including industrial and commercial wastewater, human sewage, and stormwater runoff, through a single network of pipes. Serious problems arise for combined sewer systems during heavy precipitation events when treatment plants and storage facilities are unable to accommodate the influx of wastewater needing treatment, causing the sewer system to overflow into local waterways through sewer outfalls. CSOs (Combined Sewer Overflows) pose a serious threat to human and environmental health. Principal pollutants found in CSO discharge include microbial pathogens, comprising of bacteria, viruses, parasites, oxygen-depleting substances, suspended solids, chemicals or chemical mixtures, and excess nutrients, primarily nitrogen and phosphorus. While concentrations of these pollutants can vary between overflow events, CSOs have the potential to spread disease and waterborne illnesses, contaminate drinking water supplies, disrupt aquatic life, and effect a waterbody’s designated use. This paper estimates the economic impact of CSOs on residential property values. Using residential property sales data from Seattle, Washington, this paper employs a hedonic valuation model that controls for housing and neighborhood characteristics, as well as spatial and temporal effects, to predict a consumer’s willingness to pay for improved water quality near their homes. Initial results indicate that a 100,000-gallon decrease in the average annual overflow discharged from a sewer outfall within 300 meters of a home is associated with a 0.053% increase in the property’s sale price. For the average home in the sample, the price increase is estimated to be $18,860.23. These findings reveal some of the important economic benefits of improving water quality by reducing the frequency and severity of combined sewer overflows.Keywords: benefits, hedonic, Seattle, sewer
Procedia PDF Downloads 171595 Design of Low-Cost Water Purification System Using Activated Carbon
Authors: Nayan Kishore Giri, Ramakar Jha
Abstract:
Water is a major element for the life of all the mankind in the earth. India’s surface water flows through fourteen major streams. Indian rivers are the main source of potable water in India. In the eastern part of India many toxic hazardous metals discharged into the river from mining industries, which leads many deadly diseases to human being. So the potable water quality is very significant and vital concern at present as it is related with the present and future health perspective of the human race. Consciousness of health risks linked with unsafe water is still very low among the many rural and urban areas in India. Only about 7% of total Indian people using water purifier. This unhealthy situation of water is not only present in India but also present in many underdeveloped countries. The major reason behind this is the high cost of water purifier. This current study geared towards development of economical and efficient technology for the removal of maximum possible toxic metals and pathogen bacteria. The work involves the design of portable purification system and purifying material. In this design Coconut shell granular activated carbon(GAC) and polypropylene filter cloths were used in this system. The activated carbon is impregnated with Iron(Fe). Iron is used because it enhances the adsorption capacity of activated carbon. The thorough analysis of iron impregnated activated carbon(Fe-AC) is done by Scanning Electron Microscope (SEM), X-ray diffraction (XRD) , BET surface area test were done. Then 10 ppm of each toxic metal were infiltrated through the designed purification system and they were analysed in Atomic absorption spectrum (AAS). The results are very promising and it is low cost. This work will help many people who are in need of potable water. They can be benefited for its affordability. It could be helpful in industries and other domestic usage.Keywords: potable water, coconut shell GAC, polypropylene filter cloths, SEM, XRD, BET, AAS
Procedia PDF Downloads 376594 Antimicrobial, Antioxidant Activities, and Phytochemical Screening of Five Species from Acacia Used in Sudanese Ethnomedicine
Authors: Hajir, B. Abdllha, , Alaa, I. Mohamed, Khansa, A. Almoniem, Naga, I. Adam, Wdeea, Alhaadi, Ahmed, A. Elshikh, Ahmed, J. Ali, Ismail, G. Makuar, Anas, M. Elnazeer, Nagat, A. Elrofaei, Samir, F. Abdoelftah, Monier, N. Hemidan
Abstract:
The present study was designed to investigate antimicrobial, and antioxidant activities of five species from Acacia (Acacia albidia, Acacia mellifera, Acacia nubica, Acacia seyal var.seyal and Acacia tortilis). Phytochemical study was piloted to detect the bioactive compounds, which have been responsible from the biological activities. The ethanol, chloroform and acetone plant extracts were seasoned against standard bacteria strains of gram +ve bacteria Staphylococcus aureus (ATCC 25923) ,Gram -ve bacteria Pseudomonas aeruginosa (ATCC 27853) and standard fungi Candida albicans (ATCC 90028), using cup-plate method. The antioxidant activities were conducted via DPPH radical scavenging and metal chelating assays. Prospective activity against the five species was observed in acetone extract. Ethanol extract showed highest activities against Staphylococcus aureus, and Candida albicans. Potential antioxidant activity was presented by ethanol. Cholorophorm and acetone extracts via DPPH, the radical scavenging activities were found to be 91±0.03, 88±0.01 and 85±0.04 respectively. The results of phytochemical screening showed that all extracts of studied plant contain flavonoids, saponins, terpenoids, steroids, alkaloids, phenols and tannins. This study give rise to antioxidant, antimicrobial properties of studied plant, and showed interesting correlation with the phytochemical constituents and biological activities.Keywords: antimicrobial, Antioxidant, Acacia albidia, Acacia mellifera, acacia nubica, acacia seyal var.seyal, Acacia tortilis
Procedia PDF Downloads 549593 Coumestrol Induced Apoptosis in Breast Cancer MCF-7 Cells via Redox Cycling of Copper and ROS Generation: Implications of Copper Chelation Strategy in Cancer Treatment
Authors: Atif Zafar Khan, Swarnendra Singh, Imrana Naseem
Abstract:
Breast cancer is one of the most frequent malignancies in women worldwide and a leading cause of cancer-related deaths among women. Therefore, there is a need to identify new chemotherapeutic strategies for cancer treatment. Unlike normal cells, cancer cells contain elevated copper levels which play an integral role in angiogenesis. Copper is an important metal ion associated with the chromatin DNA, particularly with guanine. Thus, targeting copper via copper-specific chelators in cancer cells can serve as effective anticancer strategy. Keeping in view these facts, we evaluated the anticancer activity and copper-dependent cytotoxic effect of coumestrol (phytoestrogen in soybean products) in breast cancer MCF-7 cells. Coumestrol inhibited proliferation and induced apoptosis in MCF-7 cells, which was prevented by copper chelator neocuproine and ROS scavengers. Coumestrol treatment induced ROS generation coupled to DNA fragmentation, up-regulation of p53/p21, cell cycle arrest at G1/S phase, mitochondrial membrane depolarization and caspases 9/3 activation. All these effects were suppressed by ROS scavengers and neocuproine. These results suggest that coumestrol targets elevated copper for redox cycling to generate ROS leading to DNA fragmentation. DNA damage leads to p53 up-regulation which directs the cell cycle arrest at G1/S phase and promotes caspase-dependent apoptosis of MCF-7 cells. In conclusion, coumestrol induces pro-oxidant cell death by chelating cellular copper to produce copper-coumestrol complexes that engages in redox cycling in breast cancer cells. Thus, targeting elevated copper levels might be a potential therapeutic strategy for selective cytotoxic action against malignant cells.Keywords: apoptosis, breast cancer, copper chelation, coumestrol, reactive oxygens species, redox cycling
Procedia PDF Downloads 239592 The Thinking of Dynamic Formulation of Rock Aging Agent Driven by Data
Authors: Longlong Zhang, Xiaohua Zhu, Ping Zhao, Yu Wang
Abstract:
The construction of mines, railways, highways, water conservancy projects, etc., have formed a large number of high steep slope wounds in China. Under the premise of slope stability and safety, the minimum cost, green and close to natural wound space repair, has become a new problem. Nowadays, in situ element testing and analysis, monitoring, field quantitative factor classification, and assignment evaluation will produce vast amounts of data. Data processing and analysis will inevitably differentiate the morphology, mineral composition, physicochemical properties between rock wounds, by which to dynamically match the appropriate techniques and materials for restoration. In the present research, based on the grid partition of the slope surface, tested the content of the combined oxide of rock mineral (SiO₂, CaO, MgO, Al₂O₃, Fe₃O₄, etc.), and classified and assigned values to the hardness and breakage of rock texture. The data of essential factors are interpolated and normalized in GIS, which formed the differential zoning map of slope space. According to the physical and chemical properties and spatial morphology of rocks in different zones, organic acids (plant waste fruit, fruit residue, etc.), natural mineral powder (zeolite, apatite, kaolin, etc.), water-retaining agent, and plant gum (melon powder) were mixed in different proportions to form rock aging agents. To spray the aging agent with different formulas on the slopes in different sections can affectively age the fresh rock wound, providing convenience for seed implantation, and reducing the transformation of heavy metals in the rocks. Through many practical engineering practices, a dynamic data platform of rock aging agent formula system is formed, which provides materials for the restoration of different slopes. It will also provide a guideline for the mixed-use of various natural materials to solve the complex, non-uniformity ecological restoration problem.Keywords: data-driven, dynamic state, high steep slope, rock aging agent, wounds
Procedia PDF Downloads 106591 Nanowire Sensor Based on Novel Impedance Spectroscopy Approach
Authors: Valeriy M. Kondratev, Ekaterina A. Vyacheslavova, Talgat Shugabaev, Alexander S. Gudovskikh, Alexey D. Bolshakov
Abstract:
Modern sensorics imposes strict requirements on the biosensors characteristics, especially technological feasibility, and selectivity. There is a growing interest in the analysis of human health biological markers, which indirectly testifying the pathological processes in the body. Such markers are acids and alkalis produced by the human, in particular - ammonia and hydrochloric acid, which are found in human sweat, blood, and urine, as well as in gastric juice. Biosensors based on modern nanomaterials, especially low dimensional, can be used for this markers detection. Most classical adsorption sensors based on metal and silicon oxides are considered non-selective, because they identically change their electrical resistance (or impedance) under the action of adsorption of different target analytes. This work demonstrates a feasible frequency-resistive method of electrical impedance spectroscopy data analysis. The approach allows to obtain of selectivity in adsorption sensors of a resistive type. The method potential is demonstrated with analyzis of impedance spectra of silicon nanowires in the presence of NH3 and HCl vapors with concentrations of about 125 mmol/L (2 ppm) and water vapor. We demonstrate the possibility of unambiguous distinction of the sensory signal from NH3 and HCl adsorption. Moreover, the method is found applicable for analysis of the composition of ammonia and hydrochloric acid vapors mixture without water cross-sensitivity. Presented silicon sensor can be used to find diseases of the gastrointestinal tract by the qualitative and quantitative detection of ammonia and hydrochloric acid content in biological samples. The method of data analysis can be directly translated to other nanomaterials to analyze their applicability in the field of biosensory.Keywords: electrical impedance spectroscopy, spectroscopy data analysis, selective adsorption sensor, nanotechnology
Procedia PDF Downloads 109590 Evaluation of Surface Water and Groundwater Quality in Parts of Umunneochi Southeast, Nigeria
Authors: Joshua Chima Chizoba, Wisdom Izuchukwu Uzoma, Elizabeth Ifeyiwa Okoyeh
Abstract:
Water cannot be optimally used and sustained unless the quality is periodically assessed. The study area Umunneochi and environs are located in south eastern part of Nigeria. It stretches geographically from latitudes 50501N to 60000N and longitudes 70201E to 70301. The major geologic formations in the area include the Asu River group, Nkporo Shale, and Ajali Sandstone. The aim of this study is to evaluate the hydrochemical characteristics of surface and ground water sources in parts of Umunneochi and environs in order to establish portability of the water sources for drinking, domestic and irrigation purposes. A total of 15 samples were collected randomly from streams, springs and wells. The samples were analyzed for physicochemical parameters and heavy metals using handheld digital kits, photometer, titration method and Atomic Absorption Spectrophotometer (AAS) following acceptable standards. The obtained analytical data were interpreted, and results were compared with World Health Organization (WHO) standard. The concentration of pH, SO42-and Cl- range from 5.81 mg/l – 6.07 mg/l, 41.93 mg/l – 142.95 mg/l and 20.00 mg/l – 111 mg/l respectively, while Pb and Zn revealed a relative low mean concentration of 0.14 mg/l and 0.40 mg/l, which are all within (WHO) permissible limits except pH. About 27% of the samples are moderately hard. This is attributed to the mining activities in the areas. The abundance of cations and anions in the area are in the order of K+>Na+>Mg2+>Ca2+ and SO4->Cl->HCO3->NO3-, respectively. Chloride, bicarbonate, and nitrate are all within the permissible limits. 13.33% of the total samples contain Sulphate above the standard permissible limits. The values of calculated Water Quality Index (WQI) are less than 50 indicating excellent water. The predominant water-type in the study area is Na-Cl water type and mixed Ca-Mg-Cl water type based on the sample plots on the Piper diagram. The Sodium Absorption Ratio (SAR) calculations showed excellent water for consumption and also good water for irrigation purpose with low sodium and alkalinity ratio respectively. Government water projects are recommended in the area for sustainable domestic and agricultural water supply to ease the stress of water supply problems.Keywords: groundwater, hydrochemical, physichochemical, water-type, sodium adsorption ratio
Procedia PDF Downloads 129589 Infrared Photodetectors Based on Nanowire Arrays: Towards Far Infrared Region
Authors: Mohammad Karimi, Magnus Heurlin, Lars Samuelson, Magnus Borgstrom, Hakan Pettersson
Abstract:
Nanowire semiconductors are promising candidates for optoelectronic applications such as solar cells, photodetectors and lasers due to their quasi-1D geometry and large surface to volume ratio. The functional wavelength range of NW-based detectors is typically limited to the visible/near-infrared region. In this work, we present electrical and optical properties of IR photodetectors based on large square millimeter ensembles (>1million) of vertically processed semiconductor heterostructure nanowires (NWs) grown on InP substrates which operate in longer wavelengths. InP NWs comprising single or multiple (20) InAs/InAsP QDics axially embedded in an n-i-n geometry, have been grown on InP substrates using metal organic vapor phase epitaxy (MOVPE). The NWs are contacted in vertical direction by atomic layer deposition (ALD) deposition of 50 nm SiO2 as an insulating layer followed by sputtering of indium tin oxide (ITO) and evaporation of Ti and Au as top contact layer. In order to extend the sensitivity range to the mid-wavelength and long-wavelength regions, the intersubband transition within conduction band of InAsP QDisc is suggested. We present first experimental indications of intersubband photocurrent in NW geometry and discuss important design parameters for realization of intersubband detectors. Key advantages with the proposed design include large degree of freedom in choice of materials compositions, possible enhanced optical resonance effects due to periodically ordered NW arrays and the compatibility with silicon substrates. We believe that the proposed detector design offers the route towards monolithic integration of compact and sensitive III-V NW long wavelength detectors with Si technology.Keywords: intersubband photodetector, infrared, nanowire, quantum disc
Procedia PDF Downloads 375588 Discharge Estimation in a Two Flow Braided Channel Based on Energy Concept
Authors: Amiya Kumar Pati, Spandan Sahu, Kishanjit Kumar Khatua
Abstract:
River is our main source of water which is a form of open channel flow and the flow in the open channel provides with many complex phenomena of sciences that needs to be tackled such as the critical flow conditions, boundary shear stress, and depth-averaged velocity. The development of society, more or less solely depends upon the flow of rivers. The rivers are major sources of many sediments and specific ingredients which are much essential for human beings. A river flow consisting of small and shallow channels sometimes divide and recombine numerous times because of the slow water flow or the built up sediments. The pattern formed during this process resembles the strands of a braid. Braided streams form where the sediment load is so heavy that some of the sediments are deposited as shifting islands. Braided rivers often exist near the mountainous regions and typically carry coarse-grained and heterogeneous sediments down a fairly steep gradient. In this paper, the apparent shear stress formulae were suitably modified, and the Energy Concept Method (ECM) was applied for the prediction of discharges at the junction of a two-flow braided compound channel. The Energy Concept Method has not been applied for estimating the discharges in the braided channels. The energy loss in the channels is analyzed based on mechanical analysis. The cross-section of channel is divided into two sub-areas, namely the main-channel below the bank-full level and region above the bank-full level for estimating the total discharge. The experimental data are compared with a wide range of theoretical data available in the published literature to verify this model. The accuracy of this approach is also compared with Divided Channel Method (DCM). From error analysis of this method, it is observed that the relative error is less for the data-sets having smooth floodplains when compared to rough floodplains. Comparisons with other models indicate that the present method has reasonable accuracy for engineering purposes.Keywords: critical flow, energy concept, open channel flow, sediment, two-flow braided compound channel
Procedia PDF Downloads 122587 Development of an Implicit Coupled Partitioned Model for the Prediction of the Behavior of a Flexible Slender Shaped Membrane in Interaction with Free Surface Flow under the Influence of a Moving Flotsam
Authors: Mahtab Makaremi Masouleh, Günter Wozniak
Abstract:
This research is part of an interdisciplinary project, promoting the design of a light temporary installable textile defence system against flood. In case river water levels increase abruptly especially in winter time, one can expect massive extra load on a textile protective structure in term of impact as a result of floating debris and even tree trunks. Estimation of this impulsive force on such structures is of a great importance, as it can ensure the reliability of the design in critical cases. This fact provides the motivation for the numerical analysis of a fluid structure interaction application, comprising flexible slender shaped and free-surface water flow, where an accelerated heavy flotsam tends to approach the membrane. In this context, the analysis on both the behavior of the flexible membrane and its interaction with moving flotsam is conducted by finite elements based solvers of the explicit solver and implicit Abacus solver available as products of SIMULIA software. On the other hand, a study on how free surface water flow behaves in response to moving structures, has been investigated using the finite volume solver of Star CCM+ from Siemens PLM Software. An automatic communication tool (CSE, SIMULIA Co-Simulation Engine) and the implementation of an effective partitioned strategy in form of an implicit coupling algorithm makes it possible for partitioned domains to be interconnected powerfully. The applied procedure ensures stability and convergence in the solution of these complicated issues, albeit with high computational cost; however, the other complexity of this study stems from mesh criterion in the fluid domain, where the two structures approach each other. This contribution presents the approaches for the establishment of a convergent numerical solution and compares the results with experimental findings.Keywords: co-simulation, flexible thin structure, fluid-structure interaction, implicit coupling algorithm, moving flotsam
Procedia PDF Downloads 383586 Enhanced Photocatalytic H₂ Production from H₂S on Metal Modified Cds-Zns Semiconductors
Authors: Maali-Amel Mersel, Lajos Fodor, Otto Horvath
Abstract:
Photocatalytic H₂ production by H₂S decomposition is regarded to be an environmentally friendly process to produce carbon-free energy through direct solar energy conversion. For this purpose, sulphide-based materials, as photocatalysts, were widely used due to their excellent solar spectrum responses and high photocatalytic activity. The loading of proper co-catalysts that are based on cheap and earth-abundant materials on those semiconductors was shown to play an important role in the improvement of their efficiency. In this research, CdS-ZnS composite was studied because of its controllable band gap and excellent performance for H₂ evolution under visible light irradiation. The effects of the modification of this photocatalyst with different types of materials and the influence of the preparation parameters on its H₂ production activity were investigated. The CdS-ZnS composite with an enhanced photocatalytic activity for H₂ production was synthesized from ammine complexes. Two types of modification were used: compounds of Ni-group metals (NiS, PdS, and Pt) were applied as co-catalyst on the surface of CdS-ZnS semiconductor, while NiS, MnS, CoS, Ag₂S, and CuS were used as a dopant in the bulk of the catalyst. It was found that 0.1% of noble metals didn’t remarkably influence the photocatalytic activity, while the modification with 0.5% of NiS was shown to be more efficient in the bulk than on the surface. The modification with other types of metals results in a decrease of the rate of H₂ production, while the co-doping seems to be more promising. The preparation parameters (such as the amount of ammonia to form the ammine complexes, the order of the preparation steps together with the hydrothermal treatment) were also found to highly influence the rate of H₂ production. SEM, EDS and DRS analyses were made to reveal the structure of the most efficient photocatalysts. Moreover, the detection of the conduction band electron on the surface of the catalyst was also investigated. The excellent photoactivity of the CdS-ZnS catalysts with and without modification encourages further investigations to enhance the hydrogen generation by optimization of the reaction conditions.Keywords: H₂S, photoactivity, photocatalytic H₂ production, CdS-ZnS
Procedia PDF Downloads 120585 Characterization of Pectinase from Local Microorganisms to Support Industry Based Green Chemistry
Authors: Sasangka Prasetyawan, Anna Roosdiana, Diah Mardiana, Suratmo
Abstract:
Pectinase are enzymes that hydrolyze pectin compounds. The use of this enzyme is primarily to reduce the viscosity of the beverage thus simplifying the purification process. Pectinase activity influenced by microbial sources . Exploration of two types of microbes that Aspergillus spp. and Bacillus spp. pectinase give different performance, but the use of local strain is still not widely studied. The aim of this research is exploration of pectinase from A. niger and B. firmus include production conditions and characterization. Bacillus firmus incubated and shaken at a speed of 200 rpm at pH variation (5, 6, 7, 8, 9, 10), temperature (30, 35, 40, 45, 50) °C and incubation time (6, 12, 18, 24, 30, 36 ) hours. Media was centrifuged at 3000 rpm, pectinase enzyme activity determined. Enzyme production by A. niger determined to variations in temperature and pH were similar to B. firmus, but the variation of the incubation time was 24, 48, 72, 96, 120 hours. Pectinase crude extract was further purified by precipitation using ammonium sulfate saturation in fraction 0-20 %, 20-40 %, 40-60 %, 60-80 %, then dialyzed. Determination of optimum conditions pectinase activity performed by measuring the variation of enzyme activity on pH (4, 6, 7, 8, 10), temperature (30, 35, 40, 45, 50) °C, and the incubation time (10, 20, 30, 40, 50) minutes . Determination of kinetic parameters of pectinase enzyme reaction carried out by measuring the rate of enzyme reactions at the optimum conditions, but the variation of the concentration of substrate (pectin 0.1 % , 0.2 % , 0.3 % , 0.4 % , 0.5 % ). The results showed that the optimum conditions of production of pectinase from B. firmus achieved at pH 7-8.0, 40-50 ⁰C temperature and fermentation time 18 hours. Purification of pectinase showed the highest purity in the 40-80 % ammonium sulfate fraction. Character pectinase obtained : the optimum working conditions of A. niger pectinase at pH 5 , while pectinase from B. firmus at pH 7, temperature and optimum incubation time showed the same value, namely the temperature of 50 ⁰C and incubation time of 30 minutes. The presence of metal ions can affect the activity of pectinase , the concentration of Zn 2 + , Pb 2 + , Ca 2 + and K + and 2 mM Mg 2 + above 6 mM inhibit the activity of pectinase .Keywords: pectinase, Bacillus firmus, Aspergillus niger, green chemistry
Procedia PDF Downloads 363584 Mitigating Food Insecurity and Malnutrition by Promoting Carbon Farming via a Solar-Powered Enzymatic Composting Bioreactor with Arduino-Based Sensors
Authors: Molin A., De Ramos J. M., Cadion L. G., Pico R. L.
Abstract:
Malnutrition and food insecurity represent significant global challenges affecting millions of individuals, particularly in low-income and developing regions. The researchers created a solar-powered enzymatic composting bioreactor with an Arduino-based monitoring system for pH, humidity, and temperature. It manages mixed municipal solid wastes incorporating industrial enzymes and whey additives for accelerated composting and minimized carbon footprint. Within 15 days, the bioreactor yielded 54.54% compost compared to 44.85% from traditional methods, increasing yield by nearly 10%. Tests showed that the bioreactor compost had 4.84% NPK, passing metal analysis standards, while the traditional pit compost had 3.86% NPK; both are suitable for agriculture. Statistical analyses, including ANOVA and Tukey's HSD test, revealed significant differences in agricultural yield across different compost types based on leaf length, width, and number of leaves. The study compared the effects of different composts on Brassica rapa subsp. Chinesis (Petchay) and Brassica juncea (Mustasa) plant growth. For Pechay, significant effects of compost type on plant leaf length (F(5,84) = 62.33, η² = 0.79) and leaf width (F(5,84) = 12.35, η² = 0.42) were found. For Mustasa, significant effects of compost type on leaf length (F(4,70) = 20.61, η² = 0.54), leaf width (F(4,70) = 19.24, η² = 0.52), and number of leaves (F(4,70) = 13.17, η² = 0.43) were observed. This study explores the effectiveness of the enzymatic composting bioreactor and its viability in promoting carbon farming as a solution to food insecurity and malnutrition.Keywords: malnutrition, food insecurity, enzymatic composting bioreactor, arduino-based monitoring system, enzymes, carbon farming, whey additive, NPK level
Procedia PDF Downloads 50583 A Five–Year Review Study of Epidemiology of Ocular and Adnexal Injuries Requiring Surgical Intervention in a Middle Eastern Area: Al Ain, UAE
Authors: Tahra AlMahmoud, Sameeha Mohamed Al Hadhrami, Mohamed Elhanan, Hanan Naser Alshamsi, Fikri Abu-Zidan
Abstract:
Background: To the best of the author(s)’ knowledge there are no epidemiological studies for traumatic eye injuries in UAE, neither data on groups at risk or mechanisms for ocular trauma. Purpose: To report the epidemiology of eye injuries that required hospital admission and surgery at a referral center at the eastern part of Abu Dhabi. Method: Retrospective charts review of all patients who had suffered an eye injury that required surgical intervention between 2012 and 2017 at Al Ain Hospital. Demographic data, place of occurrence, the cause of injury, visual acuity (VA) before and after treatment, number of admission days and follow up were extracted. Data were tabulated and presented as number (%), mean (SD), or median (range) as appropriate. Wilcoxon signed rank test was used for VA outcome. Results: One hundred forty-one patients were identified, 96 eyes with open-globe and 48 other types of injuries. The mean age of the patients was 26±15.5 years, and 89% were male. Majority of injuries occurred at the workplace (50.4%) followed by home (31.2%). Trauma with a sharp object (24.1%), blunt object (16.3%), nail (11.3%), and hammer on metal (7.8%) were the most common etiologies of injury. Corneas injuries (48.2%) was the most frequent cause for visual acuity limitation followed by lens/cataract (23.4%). Among the traumatized eyes, 30 eyes (21.3%) retained intraocular foreign body, Mean admission days was 3.16± 2.81days (1-16) and a number of follow up visit was 3.17± 4.11times (0-26). Conclusion: Ocular trauma requiring surgical intervention is an area of concern in particular for occupations involving work with metals. This work may give insight into the value and necessity of implementing preventive measures.Keywords: epidemiology, Middle Eastern area, occupational injury, ocular traumas
Procedia PDF Downloads 126582 Understanding the Health Issues of Impoverished Child Rag Pickers in India
Authors: Burhan Khan
Abstract:
Objective: This study aims to enhance the body of knowledge about the vulnerabilities of child waste pickers in solid waste management. The primary objective of this research is to investigate the occupational menaces and their potential harm to the health of child waste pickers. Material and Methods: The present study design is descriptive in nature and involves children aged 5 through 14, who were rummaging through garbage in the roads and streets of Aligarh city, Uttar Pradesh. The researcher adopted an empirical approach to interview 65 participants (27 boys and 38 girls) across Aligarh city, Uttar Pradesh. The majority of the participants are Muslims (76.9 %), scheduled Castes (13.8 %), and Hindus (9.2 %). Out of 65 participants, 73.8% of children were migrated within the last five years. The primary data were analysed by utilising descriptive statistics, including frequencies, cross-tabs, means, and percentages. Results: The results show that the vast majority of children (87.7%) have experienced superficial injuries or open wound at their work. More than 32% were suffering from respiratory problems such as coughing, wheezing and short of breath, close to 37% reported skin problems like allergy, irritation and bruising and 4.6% had eye problems such as pain and irritation in eyes. Nearly 78% of children lift and carry a heavy load like large garbage bags. Over 83% informed that they sort through refuse in a filthy environment such as open dumpsites, effluents, and runnels. Conclusion: This research provides pieces of evidence of how children are being tormented in the rag-picking sector. It has been observed that child rag pickers are susceptible to injuries or illnesses due to work-related risks and toxic environment. In India, there is no robust policy to address the concerns of waste pickers and laws to protect their rights. Consequently, these deprived communities of rag pickers, especially children, have become more vulnerable over time in India. Hence, this research paper calls for a quick response to the exigencies of child rag picker by developing a holistic approach that deals with education, medical care, sanitation, and nutrition for child rag pickers.Keywords: child rag pickers, health impairments, occupational hazards, toxic environment
Procedia PDF Downloads 121581 Cadmium and Lead Extraction from Environmental Samples with Complexes Matrix by Nanomagnetite Solid-Phase and Determine Their Trace Amounts
Authors: Hossein Tavallali, Mohammad Ali Karimi, Gohar Deilamy-Rad
Abstract:
In this study, a new type of alumina-coated magnetite nanoparticles (Fe3O4/Al2O3 NPs) with sodium dodecyl sulfate- 1-(2-pyridylazo)-2-naphthol (SDS-PAN) as a new sorbent solid phase extraction (SPE) has been successfully synthesized and applied for preconcentration and separation of Cd and Pb in environmental samples. Compared with conventional SPE methods, the advantages of this new magnetic Mixed Hemimicelles Solid-Phase Extraction Procedure (MMHSPE) still include easy preparation and regeneration of sorbents, short times of sample pretreatment, high extraction yields, and high breakthrough volumes. It shows great analytical potential in preconcentration of Cd and Pb compounds from large volume water samples. Due to the high surface area of these new sorbents and the excellent adsorption capacity after surface modification by SDS-PAN, satisfactory concentration factor and extraction recoveries can be produced with only 0.05 g Fe3O4/Al2O3 NPs. The metals were eluted with 3mL HNO3 2 mol L-1 directly and detected with the detection system Flame Atomic Absorption Spectrometry (FAAS). Various influencing parameters on the separation and preconcentration of trace metals, such as the amount of PAN, pH value, sample volume, standing time, desorption solvent and maximal extraction volume, amount of sorbent and concentration of eluent, were studied. The detection limits of this method for Cd and Pb were 0.3 and 0.7 ng mL−1 and the R.S.D.s were 3.4 and 2.8% (C = 28.00 ng mL-1, n = 6), respectively. The preconcentration factor of the modified nanoparticles was 166.6. The proposed method has been applied to the determination of these metal ions at trace levels in soil, river, tap, mineral, spring and wastewater samples with satisfactory results.Keywords: Alumina-coated magnetite nanoparticles, Magnetic Mixed Hemimicell Solid-Phase Extraction, Cd and Pb, soil sample
Procedia PDF Downloads 311580 Synthesis, Molecular Modeling and Study of 2-Substituted-4-(Benzo[D][1,3]Dioxol-5-Yl)-6-Phenylpyridazin-3(2H)-One Derivatives as Potential Analgesic and Anti-Inflammatory Agents
Authors: Jyoti Singh, Ranju Bansal
Abstract:
Fighting pain and inflammation is a common problem faced by physicians while dealing with a wide variety of diseases. Since ancient time nonsteroidal anti-inflammatory agents (NSAIDs) and opioids have been the cornerstone of treatment therapy, however, the usefulness of both these classes is limited due to severe side effects. NSAIDs, which are mainly used to treat mild to moderate inflammatory pain, induce gastric irritation and nephrotoxicity whereas opioids show an array of adverse reactions such as respiratory depression, sedation, and constipation. Moreover, repeated administration of these drugs induces tolerance to the analgesic effects and physical dependence. Further discovery of selective COX-2 inhibitors (coxibs) suggested safety without any ulcerogenic side effects; however, long-term use of these drugs resulted in kidney and hepatic toxicity along with an increased risk of secondary cardiovascular effects. The basic approaches towards inflammation and pain treatment are constantly changing, and researchers are continuously trying to develop safer and effective anti-inflammatory drug candidates for the treatment of different inflammatory conditions such as osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, psoriasis and multiple sclerosis. Synthetic 3(2H)-pyridazinones constitute an important scaffold for drug discovery. Structure-activity relationship studies on pyridazinones have shown that attachment of a lactam at N-2 of the pyridazinone ring through a methylene spacer results in significantly increased anti-inflammatory and analgesic properties of the derivatives. Further introduction of the heterocyclic ring at lactam nitrogen results in improvement of biological activities. Keeping in mind these SAR studies, a new series of compounds were synthesized as shown in scheme 1 and investigated for anti-inflammatory, analgesic, anti-platelet activities and docking studies. The structures of newly synthesized compounds have been established by various spectroscopic techniques. All the synthesized pyridazinone derivatives exhibited potent anti-inflammatory and analgesic activity. Homoveratryl substituted derivative was found to possess highest anti-inflammatory and analgesic activity displaying 73.60 % inhibition of edema at 40 mg/kg with no ulcerogenic activity when compared to standard drugs indomethacin. Moreover, 2-substituted-4-benzo[d][1,3]dioxole-6-phenylpyridazin-3(2H)-ones derivatives did not produce significant changes in bleeding time and emerged as safe agents. Molecular docking studies also illustrated good binding interactions at the active site of the cyclooxygenase-2 (hCox-2) enzyme.Keywords: anti-inflammatory, analgesic, pyridazin-3(2H)-one, selective COX-2 inhibitors
Procedia PDF Downloads 192579 Thermo-Oxidative Degradation of Esterified Starch (with Lauric Acid) -Plastic Composite Assembled with Pro-Oxidants and Elastomers
Authors: R. M. S. Sachini Amararathne
Abstract:
This research is striving to develop a thermo degradable starch plastic compound/ masterbatch for industrial packaging applications. A native corn starch-modified with an esterification reaction of lauric acid is melt blent with an unsaturated elastomer (styrene-butadiene-rubber/styrene-butadiene-styrene). A trace amount of metal salt is added into the internal mixer to study the effect of pro-oxidants in a thermo oxidative environment. Then the granulated polymer composite which is consisted with 80-86% of polyolefin (LLDP/LDPE/PP) as the pivotal agent; is extruded with processing aids, antioxidants and some other additives in a co-rotating twin-screw extruder. The pelletized composite is subjected to compression molding/ Injection molding or blown film extrusion processes to acquire the samples/specimen for tests. The degradation process is explicated by analyzing the results of fourier transform infrared spectroscopy (FTIR) measurements, thermo oxidative aging studies (placing the dumb-bell specimen in an air oven at 70 °C for four weeks of exposure.) governed by tensile and impact strength test reports. Furthermore, the samples were elicited into manifold outdoors to inspect the degradation process. This industrial process is implemented to reduce the volume of fossil-based garbage by achieving the biodegradability and compostability in the natural cycle. Hence the research leads to manufacturing a degradable plastic packaging compound which is now available in the Sri Lankan market.Keywords: blown film extrusion, compression moulding, polyolefin, pro-oxidant, styrene-butadine-rubber, styrene-butadiene-styrene, thermo oxidative aging, unsaturated elastomer
Procedia PDF Downloads 90578 Bioremediation of Phenol in Wastewater Using Polymer-Supported Bacteria
Authors: Areej K. Al-Jwaid, Dmitiry Berllio, Andrew Cundy, Irina Savina, Jonathan L. Caplin
Abstract:
Phenol is a toxic compound that is widely distributed in the environment including the atmosphere, water and soil, due to the release of effluents from the petrochemical and pharmaceutical industries, coking plants and oil refineries. Moreover, a range of daily products, using phenol as a raw material, may find their way into the environment without prior treatment. The toxicity of phenol effects both human and environment health, and various physio-chemical methods to remediate phenol contamination have been used. While these techniques are effective, their complexity and high cost had led to search for alternative strategies to reduce and eliminate high concentrations of phenolic compounds in the environment. Biological treatments are preferable because they are environmentally friendly and cheaper than physico-chemical approaches. Some microorganisms such as Pseudomonas sp., Rhodococus sp., Acinetobacter sp. and Bacillus sp. have shown a high ability to degrade phenolic compounds to provide a sole source of energy. Immobilisation process utilising various materials have been used to protect and enhance the viability of cells, and to provide structural support for the bacterial cells. The aim of this study is to develop a new approach to the bioremediation of phenol based on an immobilisation strategy that can be used in wastewater. In this study, two bacterial species known to be phenol degrading bacteria (Pseudomonas mendocina and Rhodococus koreensis) were purchased from National Collection of Industrial, Food and Marine Bacteria (NCIMB). The two species and mixture of them were immobilised to produce macro porous crosslinked cell cryogels samples by using four types of cross-linker polymer solutions in a cryogelation process. The samples were used in a batch culture to degrade phenol at an initial concentration of 50mg/L at pH 7.5±0.3 and a temperature of 30°C. The four types of polymer solution - i. glutaraldehyde (GA), ii. Polyvinyl alcohol with glutaraldehyde (PVA+GA), iii. Polyvinyl alcohol–aldehyde (PVA-al) and iv. Polyetheleneimine–aldehyde (PEI-al), were used at different concentrations, ranging from 0.5 to 1.5% to crosslink the cells. The results of SEM and rheology analysis indicated that cell-cryogel samples crosslinked with the four cross-linker polymers formed monolithic macro porous cryogels. The samples were evaluated for their ability to degrade phenol. Macro porous cell–cryogels crosslinked with GA and PVA+GA showed an ability to degrade phenol for only one week, while the other samples crosslinked with a combination of PVA-al + PEI-al at two different concentrations have shown higher stability and viability to reuse to degrade phenol at concentration (50 mg/L) for five weeks. The initial results of using crosslinked cell cryogel samples to degrade phenol indicate that is a promising tool for bioremediation strategies especially to eliminate and remove the high concentration of phenol in wastewater.Keywords: bioremediation, crosslinked cells, immobilisation, phenol degradation
Procedia PDF Downloads 225577 Enhanced Furfural Extraction from Aqueous Media Using Neoteric Hydrophobic Solvents
Authors: Ahmad S. Darwish, Tarek Lemaoui, Hanifa Taher, Inas M. AlNashef, Fawzi Banat
Abstract:
This research reports a systematic top-down approach for designing neoteric hydrophobic solvents –particularly, deep eutectic solvents (DES) and ionic liquids (IL)– as furfural extractants from aqueous media for the application of sustainable biomass conversion. The first stage of the framework entailed screening 32 neoteric solvents to determine their efficacy against toluene as the application’s conventional benchmark for comparison. The selection criteria for the best solvents encompassed not only their efficiency in extracting furfural but also low viscosity and minimal toxicity levels. Additionally, for the DESs, their natural origins, availability, and biodegradability were also taken into account. From the screening pool, two neoteric solvents were selected: thymol:decanoic acid 1:1 (Thy:DecA) and trihexyltetradecyl phosphonium bis(trifluoromethylsulfonyl) imide [P₁₄,₆,₆,₆][NTf₂]. These solvents outperformed the toluene benchmark, achieving efficiencies of 94.1% and 97.1% respectively, compared to toluene’s 81.2%, while also possessing the desired properties. These solvents were then characterized thoroughly in terms of their physical properties, thermal properties, critical properties, and cross-contamination solubilities. The selected neoteric solvents were then extensively tested under various operating conditions, and an exceptional stable performance was exhibited, maintaining high efficiency across a broad range of temperatures (15–100 °C), pH levels (1–13), and furfural concentrations (0.1–2.0 wt%) with a remarkable equilibrium time of only 2 minutes, and most notably, demonstrated high efficiencies even at low solvent-to-feed ratios. The durability of the neoteric solvents was also validated to be stable over multiple extraction-regeneration cycles, with limited leachability to the aqueous phase (≈0.1%). Moreover, the extraction performance of the solvents was then modeled through machine learning, specifically multiple non-linear regression (MNLR) and artificial neural networks (ANN). The models demonstrated high accuracy, indicated by their low absolute average relative deviations with values of 2.74% and 2.28% for Thy:DecA and [P₁₄,₆,₆,₆][NTf₂], respectively, using MNLR, and 0.10% for Thy:DecA and 0.41% for [P₁₄,₆,₆,₆][NTf₂] using ANN, highlighting the significantly enhanced predictive accuracy of the ANN. The neoteric solvents presented herein offer noteworthy advantages over traditional organic solvents, including their high efficiency in both extraction and regeneration processes, their stability and minimal leachability, making them particularly suitable for applications involving aqueous media. Moreover, these solvents are more environmentally friendly, incorporating renewable and sustainable components like thymol and decanoic acid. This exceptional efficacy of the newly developed neoteric solvents signifies a significant advancement, providing a green and sustainable alternative for furfural production from biowaste.Keywords: sustainable biomass conversion, furfural extraction, ionic liquids, deep eutectic solvents
Procedia PDF Downloads 64576 Modeling of Bipolar Charge Transport through Nanocomposite Films for Energy Storage
Authors: Meng H. Lean, Wei-Ping L. Chu
Abstract:
The effects of ferroelectric nanofiller size, shape, loading, and polarization, on bipolar charge injection, transport, and recombination through amorphous and semicrystalline polymers are studied. A 3D particle-in-cell model extends the classical electrical double layer representation to treat ferroelectric nanoparticles. Metal-polymer charge injection assumes Schottky emission and Fowler-Nordheim tunneling, migration through field-dependent Poole-Frenkel mobility, and recombination with Monte Carlo selection based on collision probability. A boundary integral equation method is used for solution of the Poisson equation coupled with a second-order predictor-corrector scheme for robust time integration of the equations of motion. The stability criterion of the explicit algorithm conforms to the Courant-Friedrichs-Levy limit. Trajectories for charge that make it through the film are curvilinear paths that meander through the interspaces. Results indicate that charge transport behavior depends on nanoparticle polarization with anti-parallel orientation showing the highest leakage conduction and lowest level of charge trapping in the interaction zone. Simulation prediction of a size range of 80 to 100 nm to minimize attachment and maximize conduction is validated by theory. Attached charge fractions go from 2.2% to 97% as nanofiller size is decreased from 150 nm to 60 nm. Computed conductivity of 0.4 x 1014 S/cm is in agreement with published data for plastics. Charge attachment is increased with spheroids due to the increase in surface area, and especially so for oblate spheroids showing the influence of larger cross-sections. Charge attachment to nanofillers and nanocrystallites increase with vol.% loading or degree of crystallinity, and saturate at about 40 vol.%.Keywords: nanocomposites, nanofillers, electrical double layer, bipolar charge transport
Procedia PDF Downloads 345575 An Investigation of the Effects of Gripping Systems in Geosynthetic Shear Testing
Authors: Charles Sikwanda
Abstract:
The use of geosynthetic materials in geotechnical engineering projects has rapidly increased over the past several years. These materials have resulted in improved performance and cost reduction of geotechnical structures as compared to the use of conventional materials. However, working with geosynthetics requires knowledge of interface parameters for design. These parameters are typically determined by the large direct shear device in accordance with ASTM-D5321 and ASTM-D6243 standards. Although these laboratory tests are standardized, the quality of the results can be largely affected by several factors that include; the shearing rate, applied normal stress, gripping mechanism, and type of the geosynthetic specimens tested. Amongst these factors, poor surface gripping of a specimen is the major source of the discrepancy. If the specimen is inadequately secured to the shearing blocks, it experiences progressive failure and shear strength that deviates from the true field performance of the tested material. This leads to inaccurate, unsafe, and cost ineffective designs of projects. Currently, the ASTM-D5321 and ASTM-D6243 standards do not provide a standardized gripping system for geosynthetic shear strength testing. Over the years, researchers have come up with different gripping systems that can be used such as; glue, metal textured surface, sandblasting, and sandpaper. However, these gripping systems are regularly not adequate to sufficiently secure the tested specimens to the shearing device. This has led to large variability in test results and difficulties in results interpretation. Therefore, this study was aimed at determining the effects of gripping systems in geosynthetic interface shear strength testing using a 300 x 300 mm direct shear box. The results of the research will contribute to easy data interpretation and increase result accuracy and reproducibility.Keywords: geosynthetics, shear strength parameters, gripping systems, gripping
Procedia PDF Downloads 199574 Analysis of Extreme Rainfall Trends in Central Italy
Authors: Renato Morbidelli, Carla Saltalippi, Alessia Flammini, Marco Cifrodelli, Corrado Corradini
Abstract:
The trend of magnitude and frequency of extreme rainfalls seems to be different depending on the investigated area of the world. In this work, the impact of climate change on extreme rainfalls in Umbria, an inland region of central Italy, is examined using data recorded during the period 1921-2015 by 10 representative rain gauge stations. The study area is characterized by a complex orography, with altitude ranging from 200 to more than 2000 m asl. The climate is very different from zone to zone, with mean annual rainfall ranging from 650 to 1450 mm and mean annual air temperature from 3.3 to 14.2°C. Over the past 15 years, this region has been affected by four significant droughts as well as by six dangerous flood events, all with very large impact in economic terms. A least-squares linear trend analysis of annual maximums over 60 time series selected considering 6 different durations (1 h, 3 h, 6 h, 12 h, 24 h, 48 h) showed about 50% of positive and 50% of negative cases. For the same time series the non-parametrical Mann-Kendall test with a significance level 0.05 evidenced only 3% of cases characterized by a negative trend and no positive case. Further investigations have also demonstrated that the variance and covariance of each time series can be considered almost stationary. Therefore, the analysis on the magnitude of extreme rainfalls supplies the indication that an evident trend in the change of values in the Umbria region does not exist. However, also the frequency of rainfall events, with particularly high rainfall depths values, occurred during a fixed period has also to be considered. For all selected stations the 2-day rainfall events that exceed 50 mm were counted for each year, starting from the first monitored year to the end of 2015. Also, this analysis did not show predominant trends. Specifically, for all selected rain gauge stations the annual number of 2-day rainfall events that exceed the threshold value (50 mm) was slowly decreasing in time, while the annual cumulated rainfall depths corresponding to the same events evidenced trends that were not statistically significant. Overall, by using a wide available dataset and adopting simple methods, the influence of climate change on the heavy rainfalls in the Umbria region is not detected.Keywords: climate changes, rainfall extremes, rainfall magnitude and frequency, central Italy
Procedia PDF Downloads 234573 Development of Composite Materials for CO2 Reduction and Organic Compound Decomposition
Authors: H. F. Shi, C. L. Zhang
Abstract:
Visible-light-responsive g-C3N4/NaNbO3 nanowires photocatalysts were fabricated by introducing polymeric g-C3N4 on NaNbO3 nanowires. The microscopic mechanisms of interface interaction, charge transfer and separation, as well as the influence on the photocatalytic activity of g-C3N4/NaNbO3 composite were systematic investigated. The HR-TEM revealed that an intimate interface between C3N4 and NaNbO3 nanowires formed in the g-C3N4/NaNbO3 heterojunctions. The photocatalytic performance of photocatalysts was evaluated for CO2 reduction under visible-light illumination. Significantly, the activity of g-C3N4/NaNbO3 composite photocatalyst for photoreduction of CO2 was higher than that of either single-phase g-C3N4 or NaNbO3. Such a remarkable enhancement of photocatalytic activity was mainly ascribed to the improved separation and transfer of photogenerated electron-hole pairs at the intimate interface of g-C3N4/NaNbO3 heterojunctions, which originated from the well-aligned overlapping band structures of C3N4 and NaNbO3. Pt loaded NaNbO3-xNx (Pt-NNON), a visible-light-sensitive photocatalyst, was synthesized by an in situ photodeposition method from H2PtCl6•6H2O onto NaNbO3-xNx (NNON) sample. Pt-NNON exhibited a much higher photocatalytic activity for gaseous 2-propanol (IPA) degradation under visible-light irradiation in contrast to NNON. The apparent quantum efficiency (AQE) of Pt-NNON sample for IPA photodegradation achieved up to 8.6% at the wavelength of 419 nm. The notably enhanced photocatalytic performance was attributed to the promoted charge separation and transfer capability in the Pt-NNON system. This work suggests that surface nanosteps possibly play an important role as an electron transfer at high way, which facilitates to the charge carrier collection onto Pt rich zones and thus suppresses recombination between photogenerated electrons and holes. This method can thus be considered as an excellent strategy to enhance photocatalytic activity of organic decomposition in addition to the commonly applied noble metal doping method.Keywords: CO2 reduction, NaNbO3, nanowires, g-C3N4
Procedia PDF Downloads 198572 Performance of Non-Deterministic Structural Optimization Algorithms Applied to a Steel Truss Structure
Authors: Ersilio Tushaj
Abstract:
The efficient solution that satisfies the optimal condition is an important issue in the structural engineering design problem. The new codes of structural design consist in design methodology that looks after the exploitation of the total resources of the construction material. In recent years some non-deterministic or meta-heuristic structural optimization algorithms have been developed widely in the research community. These methods search the optimum condition starting from the simulation of a natural phenomenon, such as survival of the fittest, the immune system, swarm intelligence or the cooling process of molten metal through annealing. Among these techniques the most known are: the genetic algorithms, simulated annealing, evolution strategies, particle swarm optimization, tabu search, ant colony optimization, harmony search and big bang crunch optimization. In this study, five of these algorithms are applied for the optimum weight design of a steel truss structure with variable geometry but fixed topology. The design process selects optimum distances and size sections from a set of commercial steel profiles. In the formulation of the design problem are considered deflection limitations, buckling and allowable stress constraints. The approach is repeated starting from different initial populations. The design problem topology is taken from an existing steel structure. The optimization process helps the engineer to achieve good final solutions, avoiding the repetitive evaluation of alternative designs in a time consuming process. The algorithms used for the application, the results of the optimal solutions, the number of iterations and the minimal weight designs, will be reported in the paper. Based on these results, it would be estimated, the amount of the steel that could be saved by applying structural analysis combined with non-deterministic optimization methods.Keywords: structural optimization, non-deterministic methods, truss structures, steel truss
Procedia PDF Downloads 222571 Evaluation of Chitin Filled Epoxy Coating for Corrosion Protection of Q235 Steel in Saline Environment
Authors: Innocent O. Arukalam, Emeka E. Oguzie
Abstract:
Interest in the development of eco-friendly anti-corrosion coatings using bio-based renewable materials is gaining momentum recently. To this effect, chitin biopolymer, which is non-toxic, biodegradable, and inherently possesses anti-microbial property, was successfully synthesized from snail shells and used as a filler in the preparation of epoxy coating. The chitin particles were characterized with contact angle goniometer, scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectrophotometer, and X-ray diffractometer (XRD). The performance of the coatings was evaluated by immersion and electrochemical impedance spectroscopy (EIS) tests. Electronic structure properties of the coating ingredients and molecular level interaction of the corrodent and coated Q235 steel were appraised by quantum chemical computations (QCC) and molecular dynamics (MD) simulation techniques, respectively. The water contact angle (WCA) measurement of chitin particles was found to be 129.3o while that of chitin particles modified with amino trimethoxy silane (ATMS) was 149.6o, suggesting it is highly hydrophobic. Immersion and EIS analyses revealed that epoxy coating containing silane-modified chitin exhibited lowest water absorption and highest barrier as well as anti-corrosion performances. The QCC showed that quantum parameters for the coating containing silane-modified chitin are optimum and therefore corresponds to high corrosion protection. The high negative value of adsorption energies (Eads) for the coating containing silane-modified chitin indicates the coating molecules interacted and adsorbed strongly on the steel surface. The observed results have shown that silane-modified epoxy-chitin coating would perform satisfactorily for surface protection of metal structures in saline environment.Keywords: chitin, EIS, epoxy coating, hydrophobic, molecular dynamics simulation, quantum chemical computation
Procedia PDF Downloads 86570 Jurisdiction of Military Court for Military Members Who Committed General Crimes in Indonesia's Military Justice System and Comparison with Another Countries
Authors: Dini Dewi Heniarti
Abstract:
Military Court which is a judicial institution within the military institution has a heavy duty. Military court has to ensuring a fair legal process for military personnel (due process of law) and enforces military discipline. Military justice must also ensure protects the rights of military personnel. In Indonesia tren of military court changes in vision. The debate is happened on the jurisdiction of military court that allegedly has the potential existence of impunity. The Decree of People’s Consultative Assembly Number VII/MPR/2000 which states that the army general who committed the crime should not be tried in military court is one that underlies the proposed amendment limits the jurisdiction of military court. For the identify of the background in a specific format that is limited to juridical review. The goals this research is to gain knowledge, deep understanding and the concept of jurisdiction of military courts for military members who committed general crimes in adjudication procedure from the perspective of legal reform as alternative to establish independency of military judiciary. This research using Rule of Law as Grand Theory, Development Legal Theory as a Middle Theory and Criminal Justice System and concept of jurisdiction as supporting as Applied Theory. This study using a normative juridical approach, and equipped by primary data juridical approach of historical and comparative approach. The author uses descriptive analytical specifications. The main data used in this research is secondary data, which includes primary legal materials, secondary legal material and legal materials tertiary. Analysis primary data and qualitative data is done legally. Technique checking the validity of the data in this study used multiple methods with the research triangulation. This paper will demonstrate the problems concerning the jurisdiction of military courts for military personnel who committed general crimes in perspective of military justice reform Indonesia and adjudication procedures for military member who committed general crimes in the military justice system in Indonesia, as alternative to establish independency of judiciary in military justice in Indonesia. Comparative approached the military justice system from another countries is aimed to development military justice in Indonesia.Keywords: jurisdiction, military courts, military justice, independency of judiciary
Procedia PDF Downloads 564569 Carboxyfullerene-Modified Titanium Dioxide Nanoparticles in Singlet Oxygen and Hydroxyl Radicals Scavenging Activity
Authors: Kai-Cheng Yang, Yen-Ling Chen, Er-Chieh Cho, Kuen-Chan Lee
Abstract:
Titanium dioxide nanomaterials offer superior protection for human skin against the full spectrum of ultraviolet light. However, some literature reviews indicated that it might be associated with adverse effects such as cytotoxicity or reactive oxygen species (ROS) due to their nanoscale. The surface of fullerene is covered with π electrons constituting aromatic structures, which can effectively scavenge large amount of radicals. Unfortunately, fullerenes are poor solubility in water, severe aggregation, and toxicity in biological applications when dispersed in solvent have imposed the limitations to the use of fullerenes. Carboxyfullerene acts as the scavenger of radicals for several years. Some reports indicate that carboxyfullerene not only decrease the concentration of free radicals in ambience but also prevent cells from reducing the number or apoptosis under UV irradiation. The aim of this study is to decorate fullerene –C70-carboxylic acid (C70-COOH) on the surface of titanium dioxide nanoparticles (P25) for the purpose of scavenging ROS during the irradiation. The modified material is prepared through the esterification of C70-COOH with P25 (P25/C70-COOH). The binding edge and structure are studied by using Transmission electron microscope (TEM) and Fourier transform infrared (FTIR). The diameter of P25 is about 30 nm and C70-COOH is found to be conjugated on the edge of P25 in aggregation morphology with the size of ca. 100 nm. In the next step, the FTIR was used to confirm the binding structure between P25 and C70-COOH. There are two new peaks are shown at 1427 and 1720 cm-1 for P25/C70-COOH, resulting from the C–C stretch and C=O stretch formed during esterification with dilute sulfuric acid. The IR results further confirm the chemically bonded interaction between C70-COOH and P25. In order to provide the evidence of scavenging radical ability of P25/C70-COOH, we chose pyridoxine (Vit.B6) and terephthalic acid (TA) to react with singlet oxygen and hydroxyl radicals. We utilized these chemicals to observe the radicals scavenging statement via detecting the intensity of ultraviolet adsorption or fluorescence emission. The UV spectra are measured by using different concentration of C70-COOH modified P25 with 1mM pyridoxine under UV irradiation for various duration times. The results revealed that the concentration of pyridoxine was increased when cooperating with P25/C70-COOH after three hours as compared with control (only P25). It indicates fewer radicals could be reacted with pyridoxine because of the absorption via P25/C70-COOH. The fluorescence spectra are observed by measuring P25/C70-COOH with 1mM terephthalic acid under UV irradiation for various duration times. The fluorescence intensity of TAOH was decreased in ten minutes when cooperating with P25/C70-COOH. Here, it was found that the fluorescence intensity was increased after thirty minutes, which could be attributed to the saturation of C70-COOH in the absorption of radicals. However, the results showed that the modified P25/C70-COOH could reduce the radicals in the environment. Therefore, we expect that P25/C70-COOH is a potential materials in using for antioxidant.Keywords: titanium dioxide, fullerene, radical scavenging activity, antioxidant
Procedia PDF Downloads 398568 Chemical Analysis of Particulate Matter (PM₂.₅) and Volatile Organic Compound Contaminants
Authors: S. Ebadzadsahraei, H. Kazemian
Abstract:
The main objective of this research was to measure particulate matter (PM₂.₅) and Volatile Organic Compound (VOCs) as two classes of air pollutants, at Prince George (PG) neighborhood in warm and cold seasons. To fulfill this objective, analytical protocols were developed for accurate sampling and measurement of the targeted air pollutants. PM₂.₅ samples were analyzed for their chemical composition (i.e., toxic trace elements) in order to assess their potential source of emission. The City of Prince George, widely known as the capital of northern British Columbia (BC), Canada, has been dealing with air pollution challenges for a long time. The city has several local industries including pulp mills, a refinery, and a couple of asphalt plants that are the primary contributors of industrial VOCs. In this research project, which is the first study of this kind in this region it measures physical and chemical properties of particulate air pollutants (PM₂.₅) at the city neighborhood. Furthermore, this study quantifies the percentage of VOCs at the city air samples. One of the outcomes of this project is updated data about PM₂.₅ and VOCs inventory in the selected neighborhoods. For examining PM₂.₅ chemical composition, an elemental analysis methodology was developed to measure major trace elements including but not limited to mercury and lead. The toxicity of inhaled particulates depends on both their physical and chemical properties; thus, an understanding of aerosol properties is essential for the evaluation of such hazards, and the treatment of such respiratory and other related diseases. Mixed cellulose ester (MCE) filters were selected for this research as a suitable filter for PM₂.₅ air sampling. Chemical analyses were conducted using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) for elemental analysis. VOCs measurement of the air samples was performed using a Gas Chromatography-Flame Ionization Detector (GC-FID) and Gas Chromatography-Mass Spectrometry (GC-MS) allowing for quantitative measurement of VOC molecules in sub-ppb levels. In this study, sorbent tube (Anasorb CSC, Coconut Charcoal), 6 x 70-mm size, 2 sections, 50/100 mg sorbent, 20/40 mesh was used for VOCs air sampling followed by using solvent extraction and solid-phase micro extraction (SPME) techniques to prepare samples for measuring by a GC-MS/FID instrument. Air sampling for both PM₂.₅ and VOC were conducted in summer and winter seasons for comparison. Average concentrations of PM₂.₅ are very different between wildfire and daily samples. At wildfire time average of concentration is 83.0 μg/m³ and daily samples are 23.7 μg/m³. Also, higher concentrations of iron, nickel and manganese found at all samples and mercury element is found in some samples. It is able to stay too high doses negative effects.Keywords: air pollutants, chemical analysis, particulate matter (PM₂.₅), volatile organic compound, VOCs
Procedia PDF Downloads 138567 Chemical and Physical Properties and Biocompatibility of Ti–6Al–4V Produced by Electron Beam Rapid Manufacturing and Selective Laser Melting for Biomedical Applications
Authors: Bing–Jing Zhao, Chang-Kui Liu, Hong Wang, Min Hu
Abstract:
Electron beam rapid manufacturing (EBRM) or Selective laser melting is an additive manufacturing process that uses 3D CAD data as a digital information source and energy in the form of a high-power laser beam or electron beam to create three-dimensional metal parts by fusing fine metallic powders together.Object:The present study was conducted to evaluate the mechanical properties ,the phase transformation,the corrosivity and the biocompatibility of Ti-6Al-4V by EBRM,SLM and forging technique.Method: Ti-6Al-4V alloy standard test pieces were manufactured by EBRM, SLM and forging technique according to AMS4999,GB/T228 and ISO 10993.The mechanical properties were analyzed by universal test machine. The phase transformation was analyzed by X-ray diffraction and scanning electron microscopy. The corrosivity was analyzed by electrochemical method. The biocompatibility was analyzed by co-culturing with mesenchymal stem cell and analyzed by scanning electron microscopy (SEM) and alkaline phosphatase assay (ALP) to evaluate cell adhesion and differentiation, respectively. Results: The mechanical properties, the phase transformation, the corrosivity and the biocompatibility of Ti-6Al-4V by EBRM、SLM were similar to forging and meet the mechanical property requirements of AMS4999 standard. aphase microstructure for the EBM production contrast to the a’phase microstructure of the SLM product. Mesenchymal stem cell adhesion and differentiation were well. Conclusion: The property of the Ti-6Al-4V alloy manufactured by EBRM and SLM technique can meet the medical standard from this study. But some further study should be proceeded in order to applying well in clinical practice.Keywords: 3D printing, Electron Beam Rapid Manufacturing (EBRM), Selective Laser Melting (SLM), Computer Aided Design (CAD)
Procedia PDF Downloads 451