Search results for: exposed

Authors: Annie Ramanbhai Mecwan

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Cleaning validation in a pharmaceutical manufacturing facility is documented evidence that a cleaning process has effectively removed contaminants, residues from previous drug products and cleaning agents below a pre-defined threshold from the reusable tools and parts of equipment. In shared manufacturing facilities more than one drug product is prepared. After cleaning of reusable tools and parts of equipment after one drug product manufacturing, there are chances that some residues of drug substance from previously manufactured drug products may be retained on the equipment and can carried forward to the next drug product and thus cause cross-contamination. Health-based limits through the derivation of a safe threshold value called permitted daily exposure (PDE) for the residues of drug substances should be employed to identify the risks posed at these manufacturing facilities. The PDE represents a substance-specific dose that is unlikely to cause an adverse effect if an individual is exposed to or below this dose every day for a lifetime. There are different practices to calculate PDE. Data for all APIs in the public domain are considered to calculate PDE value though, company to company may vary the final PDE value based on different toxicologist’s perspective or their subjective evaluation. Hence, Regulatory agencies should take responsibility for publishing PDE values for all APIs as it is done for elemental PDEs. This will harmonize the PDE values all over the world and prevent the unnecessary load on manufacturers for cleaning validation

Keywords: active pharmaceutical ingredient, good manufacturing practice, NOAEL, no observed adverse effect level, permitted daily exposure

Procedia PDF Downloads 90

Authors: Thomas Yeboah

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In contemporary times, the incessant movement of northern children especially girls to southern Ghana at the detriment of their education is worrisome. Due to the misplaced mindset of the migrants concerning southern Ghana, majority of them move without an idea of where to stay and what to do exposing them to hash conditions of living. Majority find menial work in cocoa farms, illegal mining and head porterage business. This study was conducted in the Kumasi Metropolis to ascertain the major causes of child migration from the northern part of Ghana to the south and their living conditions. Both qualitative and quantitative tools of data collection and analysis were employed. The purposive sampling technique was used to select 90 migrants below 18 years. Specifically, interviews, focus group discussions and questionnaires were used to elicit responses from the units of analysis. The study revealed that the major cause of child migration from northern Ghana to the south is poverty. It was evident that respondents were vulnerable to the new environment in which they lived. They are exposed to harsh environmental conditions; sexual, verbal and physical assault; and harassment from arm robbers. The paper recommends that policy decisions should be able to create an enabling environment for the labour force in the north to ameliorate the compelling effects poverty has on child migration. Efforts should also be made to create a proper psychological climate in the minds of the children regarding their destination areas through sensitization and education.

Keywords: child migration, vulnerability, social exclusion, child labour, Ghana

Procedia PDF Downloads 443

Authors: Menouni Aziza, Chbihi Kaoutar, Duca Radu Corneliu, Gilissen Liesbeth, Bounou Salim, Godderis Lode, El Jaafari Samir

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In Africa, environmental and occupational health risks are mostly underreported. The aim of this research is to develop and implement a sentinel surveillance system comprising training and guidance of occupational physicians (OC) who will report new work-related diseases in African countries. A group of 30 OC are recruited and trained in each of the partner countries (Morocco, Benin and Ethiopia). Each committed OC is asked to recruit 50 workers during a consultation in a time-frame of 6 months (1500 workers per country). Workers are asked to fill out an online questionnaire about their health status and work conditions, including exposure to 20 chemicals. Urine and blood samples are then collected for human biomonitoring of common exposures. Some preliminary results showed that 92% of the employees surveyed are exposed to physical constraints, 44% to chemical agents, and 24% to biological agents. The most common physical constraints are manual handling of loads, noise pollution and thermal pollution. The most frequent chemical risks are exposure to pesticides and fuels. This project will allow a better understanding of effective sentinel systems as a promising method to gather high quality data, which can support policy-making in terms of preventing emerging work-related diseases.

Keywords: sentinel system, occupational diseases, human biomonitoring, Africa

Procedia PDF Downloads 82

Authors: L. Yu, W. K. Li, S. K. Ong, A. Y. C. Nee

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In this paper, a scalable augmented reality framework for handheld devices is presented. The presented framework is enabled by using a server-client data communication structure, in which the search for tracking targets among a database of images is performed on the server-side while pixel-wise 3D tracking is performed on the client-side, which, in this case, is a handheld mobile device. Image search on the server-side adopts a residual-enhanced image descriptors representation that gives the framework a scalability property. The tracking algorithm on the client-side is based on a gravity-aligned feature descriptor which takes the advantage of a sensor-equipped mobile device and an optimized intensity-based image alignment approach that ensures the accuracy of 3D tracking. Automatic content streaming is achieved by using a key-frame selection algorithm, client working phase monitoring and standardized rules for content communication between the server and client. The recognition accuracy test performed on a standard dataset shows that the method adopted in the presented framework outperforms the Bag-of-Words (BoW) method that has been used in some of the previous systems. Experimental test conducted on a set of video sequences indicated the real-time performance of the tracking system with a frame rate at 15-30 frames per second. The presented framework is exposed to be functional in practical situations with a demonstration application on a campus walk-around.

Keywords: augmented reality framework, server-client model, vision-based tracking, image search

Procedia PDF Downloads 275

Authors: Laura X. Martinez, Andrés F. Rodríguez, Ruth A. Catacoli

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One of the most important factors for air pollution is that the concentrations of PM₁₀ maintain a constant trend, with the exception of some places where that frequently surpasses the allowed ranges established by Colombian legislation. The community that surrounds the Universidad Libre Bogotá is inhabited by a considerable number of students and workers, all of whom are possibly being exposed to PM₁₀ for long periods of time while on campus. Thus, the chemical characterization of PM₁₀ found in the ambient air at the Universidad Libre Bogotá was identified as a problem. A Hi-Vol sampler and EPA Test Method 5 were used to determine if the quality of air is adequate for the human respiratory system. Additionally, quartz fiber filters were utilized during sampling. Samples were taken three days a week during a dry period throughout the months of November and December 2015. The gravimetric analysis method was used to determine PM₁₀ concentrations. The chemical characterization includes non-conventional carcinogenic pollutants. Atomic absorption spectrophotometry (AAS) was used for the determination of metals and VOCs were analyzed using the FTIR (Fourier transform infrared spectroscopy) method. In this way, concentrations of PM₁₀, ranging from values of 13 µg/m³ to 66 µg/m³, were obtained; these values were below standard conditions. This evidence concludes that the PM₁₀ concentrations during an exposure period of 24 hours are lower than the values established by Colombian law, Resolution 610 of 2010; however, when comparing these with the limits set by the World Health Organization (WHO), these concentrations could possibly exceed permissible levels.

Keywords: air quality, atomic absorption spectrophotometry, gas chromatography, particulate matter

Procedia PDF Downloads 256

Authors: Abdoon A.S., El Ashkar E.A., Kandil O.M., Wael H. Eisa, Shaban A.M., Khaled H.M., El Ashkar M.R., El Shaer M., Hussein H., Shaalan A.H., El Sayed M.

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Cancer is a major obstacle to human health and development worldwide. Conventional strategies for cancer intervention include surgery, chemotherapy, and radiation therapy. Recently, plasmon photothermal therapy (PPTT) was introduced as a promising treatment for the management of cancer and several non-cancerous diseases that are generally characterized by overgrowth of abnormal cells. The present work was conducted to evaluate the cytotoxic efficacy and toxicity of gold nanorods (AuNRs) in dogs and cats suffering from spontaneous mammary gland. AuNRs was injected intratumoral (IT, n=10, dose of 75 p.p.m/kg body weight) or by using spray method after surgical removal of cancer tissue (n=2) in dogs and cats. Then exposed to laser light after 60 min. Treated animals were observed every 2 days and the morphological changes in tumor size and shape were recorded. Blood samples were collected before and after treatment for checking CBC, liver and kidney functions. Results revealed that AuNRs successfully treat mammary gland tumor in dogs and cats (adenocarcinoma type 1 to IV). AuNRs induced sloughing of carcinogenic tissue within 5 to 15 days. AuNRs have no toxic effect on blood profile and the toxicity studies still under evaluation. Conclusion, AuNRs can be used for treatment of mammary gland carcinoma in dogs and cats.

Keywords: pet animals, mammary gland tumor, AuNRs, photothermal therapy, toxicity studies

Procedia PDF Downloads 384

Authors: D. Sun, T. F. Lu, A. Zander, M. Trinkle

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This paper investigates the potential use of airborne ultrasonic phased arrays for imaging in outdoor environments as a means of overcoming the limitations experienced by kinect sensors, which may fail to work in the outdoor environments due to the oversaturation of the infrared photo diodes. Ultrasonic phased arrays have been well studied for static media, yet there appears to be no comparable examination in the literature of the impact of a flowing medium on the focusing behaviour of near field focused ultrasonic arrays. This paper presents a method for predicting the sound pressure fields produced by a single ultrasound element or an ultrasonic phased array influenced by airflows. The approach can be used to determine the actual focal point location of an array exposed in a known flow field. From the presented simulation results based upon this model, it can be concluded that uniform flows in the direction orthogonal to the acoustic propagation have a noticeable influence on the sound pressure field, which is reflected in the twisting of the steering angle of the array. Uniform flows in the same direction as the acoustic propagation have negligible influence on the array. For an array impacted by a turbulent flow, determining the location of the focused sound field becomes difficult due to the irregularity and continuously changing direction and the speed of the turbulent flow. In some circumstances, ultrasonic phased arrays impacted by turbulent flows may not be capable of producing a focused sound field.

Keywords: airborne, airflow, focused sound field, ultrasonic phased array

Procedia PDF Downloads 344

Authors: Dheyaa Wajid Abbood, Mohanad Salih Farhan, Awadh E. Ajeel

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The basic goal of this study is the production of cheap building elements from plastic waste. environmentally friendly and of good thermal insulation. The study depends on the addition of plastic waste as aggregates to the mixes of concrete at different percentages by weight (12 percentages) to produce lightweight aggregate concrete the density (1095 - 1892) kg/m3.The experimental work includes 120 specimens of concrete 72 cubes (150*150*150)mm, 48 cylinder (150*300) mm. The results obtained for concrete were for local raw materials without any additional materials or treatment. The mechanical and thermal properties determined were (compressive strength, static modulus of elasticity, density, thermal conductivity (k), specific heat capacity (Cp), thermal expansion (α) after (7) days of curing at 20 0C. The increase in amount of plastic waste decreases the density of concrete which leads to decrease in the mechanical and to improvement in thermal properties. The average measured static modulus of elasticity are found less than the predicted static modulus of elasticity and splitting tensile strength (ACI 318-2008 and ACI 213R-2003). All cubes specimens when exposed to heat at (200, 400, 600 0C), the compressive strength of all mixes decreases gradually at 600 0C, the strength of lightweight aggregate concrete were disintegrated. Lightweight aggregate concrete is about 25% lighter than normal concrete in dead load, and to the improve the properties of thermal insulation of building blocks.

Keywords: LWAC, plastic waste, thermal property, thermal insulation

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Authors: Abd-Alrahman Embaby, Ayman Abu Halawa, Medhat Ramadan

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The infiltrated water into the subsurface activates expansive soil in localized manner, leading to the differential heaving and destructive of the construction. The Watershed Modeling System (WMS) and Hydrologic Engineering Center (HEC-1) are used to delineate and identify the drainage system and basin morphometry in Tabuk area, where flash floods and accumulation of water may take place. Eight drainage basins effect on Tabuk city. Three of them are expected to be high. The flash floods and surface runoff behavior in these basins are important for any protection projects. It was found that the risky areas that contain Tabuk shale could be expanded when exposed to flash floods and/or surface runoff. The resident neighborhoods in the middle of Tabuk city and affected by surface runoff of the tributaries of the basin of Wadi Abu Nishayfah, Na'am and Atanah outlet, represent high-risk zones. These high-risk neighborhoods are Al Qadsiyah, Al Maseif, Arrwdah, Al Nakhil and Al Rajhi. It can be avoided new constructions on these districts. The low or very low-risk zones include the western and the eastern districts. The western side of the city is lying in the upstream of the small basin. It is suitable for a future urban extension. The direction of surface runoff flow or storm water drain discharge should be away from Tabuk city. The quicker the water can flow out, the better it is.

Keywords: digital elevation model (DEM), flash floods, Saudi Arabia, Tabuk City, watershed modeling system (WMS)

Procedia PDF Downloads 264

Authors: Shymaa S. Zaher, Hesham M. Abd El-Fatah, Dina M. Ali

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Burullus Lagoon is the second largest lake, along the Mediterranean seashore. It exposed to over nutrient enrichment from fish farming and agricultural drainage wastes. This study assesses the present status phytoplankton response to different flow events, including domestic, agricultural, industrial, and fish farms discharge in the three main sectors of Burullus Lagoon, to focus on the influence of environmental variables on phytoplankton species composition inhabiting the Lagoon. Twelve sites representing the eastern, central, and western basin were selected during winter and summer 2018. Among the most abundant group, Chlorophyceae came in the first rank by 37.9% of the total phytoplankton densities, Bacillariophyceae (29.31%), Cyanophyceae (20.7%), Euglenophyceae (8.63%) and Dinophyceae (3.4%). Cyclotella menenghiana was the most abundant diatoms, while Scenedesmus quadricauda, S. acuminatus, and S. bijuga were highly recorded nearby the drains (in the middle sector). Phytoplankton in Burullus Lagoon attained the lowest values during the winter season and the highest ones during the summer season. The total count of phytoplankton in the middle and western basin of the lake was higher than that of the eastern part. Excessive use of chemical fertilizers, pesticides, and washing out of nutrients loaded to the drainage water, leading to a significant pronounced decrease in community composition and standing crop of phytoplankton in Burullus Lake from year to year, hold the danger of shifting the lagoon ecosystem.

Keywords: Burullus Lagoon, environmental variables, phytoplankton, water pollution

Procedia PDF Downloads 124

Authors: Neha Singh, Anshuman Rana

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Gender-Based Violence (GBV) is a violation of human rights and a form of discrimination which reinforces inequalities between men and women. It is defined as violence that is directed against a person on the basis of gender. There has been increased attention to human trafficking that has exposed to illegal migration. Trafficking is complex, but it generally takes place due to “push and pull factors”. India is both a source as well as a transit country for trafficking. Women are bought and sold with impunity and trafficked to other countries. They are forced to work as sex worker, forced labour and other practices of slavery. Trafficked victims often suffer from serious abuse and physical exhaustion. The effects of violence on women vary widely. GBV typically has physical, psychological and social effects. They face unwanted pregnancies, miscarriages, high rate of infertility and sexually transmitted disease. The social exclusion of women is so great that it constitutes a new form of apartheid. Women are considered as lesser value and deprived of their fundamental rights. Violation of human rights and fundamental freedom such as- trafficking of women, girls for sex trade, forced prostitution and sex tourism have become the focus of internationally organized crimes. My paper will analyse the impact of violence on society as well. Law alone cannot change the scenario and problem of gender-biasness. The whole issue of gender violence needs social awakening and change in attitude of masses, so that due respect and equal status is given to women.

Keywords: gender-based violence, trafficking, migration, violence impact, social exclusion, law enforcement

Procedia PDF Downloads 283

Authors: Can Otuzbir

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It is one of the most difficult areas of civil engineering to provide long-lasting structures with the rapid development of concrete and reinforced concrete structures. Concrete is a living material, and the structure where the concrete is located is constantly exposed to external influences. One of these effects is reinforcement corrosion. Reinforcement corrosion of reinforced concrete structures leads to a significant decrease in the carrying capacity of the structural elements, as well as reduced service life. It is undesirable that the service life should be completed sooner than expected. In recent years, advances in glass fiber technology and its use with concrete have developed rapidly. As a result of inability to protect steel reinforcements against corrosion, fiberglass reinforcements have started to be investigated as an alternative material to steel reinforcements, and researches and experimental studies are still continuing. Glass fiber reinforcements have become an alternative material to steel reinforcement because they are resistant to corrosion, lightweight and simple to install compared to steel reinforcement. Glass fiber reinforcements are not corroded and have higher tensile strength, longer life, lighter and insulating properties compared to steel reinforcement. In experimental studies, glass fiber reinforcements have been shown to show superior mechanical properties similar to beams produced with steel reinforcement. The performance of long-term use of glass fiber fibers continues with accelerated experimental studies.

Keywords: glass fiber polymer reinforcement, steel fiber concrete, ultra high performance concrete, bending, GFRP

Procedia PDF Downloads 128

Authors: Vahid Changizi, Aram Rostami, Akbar Mosavi

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Purpose of study: Critical macromolecules of cells such as DNA are in exposure to damage of free radicals that induced from interaction of ionizing radiation with biological systems. Selenium and vitamin-E are natural compound that has been shown to be a direct free radical scavenger. The aim of this study was to investigate the in vivo/in vitro radioprotective effect of selenium and vitamin-E separately and synergistically against genotoxicity induced by 6MV x-rays irradiation in cultured blood lymphocytes from 15 human volunteers. Methods: Fifteen volunteers were divided in three groups include A, B and C. These groups were given slenium(800 IU), vitamin-E(100 mg) and selenium(400 IU) + vitamin-E(50 mg), respectively. Peripheral blood samples were collected from each group before(0 hr) and 1, 2 and 3 hr after selenium and vitamin-E administration (separately and synergistically). Then the blood samples were irradiated to 200 cGy of 6 Mv x-rays. After that, lymphocyte samples were cultured with mitogenic stimulation to determine the chromosomal aberrations wih micronucleus assay in cytokinesis-blocked binucleated cells. Results: The lymphocytes in the blood samples collected at 1 hr after ingestion selenium and vitamin-E, exposed in vitro to x-rays exhibited a significant decrease in the incidence of micronuclei, compared with control group at 0 hr. The maximum protection and decrease in frequency of micronuclei(50%) was observed at 1 hr after administration of selenium and vitamin-E synergistically. Conclusion: The data suggest that ingestion of selenium and vitamin-E as a radioprotector substances before exposures may reduce genetic damage caused by x-rays irradiation.

Keywords: x-rays, selenium, vitamin-e, lymphocyte, micronuclei

Procedia PDF Downloads 267

Authors: A. Bouriche, D. Merah, T. Bouchaour, L. Alachaher-Bedjaoui, U. Maschke

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Intensive research continues in the field of liquid crystals (LCs) for their potential use in modern display applications. Nematic LCs has been most commonly used due to the large birefringence and their sensitivity to even weak perturbation forces induced by electric, magnetic and optical fields. Polymer dispersed liquid crystals (PDLCs), composed of micron-sized nematic LC droplets dispersed in a polymer matrix is an important class of materials for applications in different domains of technology involving large area display devices, optical switches, phase modulators, variable attenuators, polarisers, flexible displays and smart windows. In this study the composites are prepared from mixtures of mono functional acrylic monomers, (Butylacrylate (ABu), 2-Ethylhexylacrylate (2-EHA), 2-Hydroxyethyl methacrylate (HEMA) and hydroxybutylmethacrylate (HBMA)) and two liquid crystals: (4-cyano-4'-n-pentyl-biphenyl) (5CB) and E7 which is an eutectic mixtures of four cyanoparaphenylenes. These mixtures are prepared adding the Darocur 1173 as photoinitiator, the 1.6-hexanediol diacrylate (HDDA) as cross-linker agent, and finally they are exposed to UV irradiation. The kinetic polymerization of monomer/LC mixture were investigated with the Fourier Transform Infra Red spectroscopy (FTIR). The electro-optical properties of the PDLC films were determined by measuring the voltage dependence on the transmitted light.

Keywords: acrylic monomers, films PDLC, liquid crystal, polymerisation

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Authors: Ravi Patel, Ravisinh Solanki, Dignesh Khunt

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A stability-indicating reverse phase high performance liquid chromatography (RP-HPLC) method was developed and validated for estimating Nirmatrelvir in its self-emulsifying drug delivery system (SEDDS). The separation of Nirmatrelvir and its degradation products was accomplished by employing an Agilent Zorbax Eclipse plus C18 (250 mm x 4.6 mm, 5 µm) column, through which the mobile phase 5 mM phosphate buffer (pH 4.0) as mobile phase A and Acetonitrile as mobile phase B in a ratio of (40:60 % v/v) was pumped at a flow rate of 1.0 mL/min, through the HPLC system. Chromatographic separation and elution were monitored by a photo-diode array detector at 210 nm. Stress studies have been employed to evaluate this method's ability to indicate stability. Nirmatrelvir was exposed to several stress conditions, such as acid, alkali, oxidative, photolytic, and thermal degradations. Significant degradation was observed during acid and alkali hydrolysis, and the resulting degradation product was successfully separated from the Nirmatrelvir peak, preventing any interference. Furthermore, the primary degradant produced under alkali degradation conditions was identified using UPLC-ESI-TQ-MS/MS. The method was validated in accordance with the International Council on Harmonization (ICH) and found to be selective, precise, accurate, linear, and robust. The apparent permeability of Nirmatrelvir SEDDS was 4.20 ± 0.21×10-6 cm/sec, and the average proportion of free drug recovered was 0.5%. The method developed in this study was feasible and accurate for routine quality control evaluation of Nirmatrelvir SEDDS.

Keywords: Nirmatrelvir, SEDDS, degradation study, HPLC, LC-MS/MS

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Authors: Arshad Alfoqaha, Seth Bard, Dustin Demetriou

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A new multi-physics acoustic modeling approach using ANSYS Mechanical FEA and FLUENT CFD methods is developed for modeling servers mounted to racks, such as IBM Z and IBM Power Systems, in data centers. This new approach allows users to determine the thermal and acoustic conditions that people are exposed to within the data center. The sound pressure level (SPL) exposure for a human working inside a hot aisle containment system inside the data center is studied. The SPL is analyzed at the noise source, at the human body, on the rack walls, on the containment walls, and on the ceiling and flooring plenum walls. In the acoustic CFD simulation, it is assumed that a four-inch diameter sphere with monopole acoustic radiation, placed in the middle of each rack, provides a single-source representation of all noise sources within the rack. Ffowcs Williams & Hawkings (FWH) acoustic model is employed. The target frequency is 1000 Hz, and the total simulation time for the transient analysis is 1.4 seconds, with a very small time step of 3e-5 seconds and 10 iterations to ensure convergence and accuracy. A User Defined Function (UDF) is developed to accurately simulate the acoustic noise source, and a Dynamic Mesh is applied to ensure acoustic wave propagation. Initial validation of the acoustic CFD simulation using a closed-form solution for the spherical propagation of an acoustic point source is performed.

Keywords: data centers, FLUENT, acoustics, sound pressure level, SPL, hot aisle containment, IBM

Procedia PDF Downloads 176

Authors: Viktoriia Malinovska, Iryna Kuklina, Katerina Grabicova, Milos Buric, Pavel Kozak

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Personal care products, including organic UV filters, are considered emerging contaminants and their toxic effects have been a concern for the last decades. Sunscreen compounds continually enter the surface waters via sewage water treatment due to incomplete removal and during human recreational and laundry activities. Despite the environmental occurrence of organic UV filters in the freshwater environment, little is known about their impacts on aquatic biota. In this study, environmentally relevant concentrations of 5-Benzoyl-4-hydroxy-2-methoxybenzenesulfonic acid (BP-4, 2.5 µg/L) and 2-Phenylbenzimidazole-5-sulfonic acid (PBSA, 3 µg/L) were used to evaluate the cardiac and locomotor responses of signal crayfish Pacifastacus leniusculus during a short time period. The effects of these compounds were evident in experimental animals. Specimens exposed to both tested compounds exhibited significantly bigger changes in distance moved and time movement than controls. Significant differences in changes in mean heart rate were detected in both PBSA and BP-4 experimental groups compared to control groups. Such behavioral and physiological alterations demonstrate the ecological effects of selected sunscreen compounds during a short time period. Since the evidence of the impacts of sunscreen compounds is scarce, the knowledge of how organic UV filters influence aquatic organisms is of key importance for future research.

Keywords: aquatic pollutants, behavior, freshwaters, heart rate, invertebrate

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Authors: Ting Wang, Pierre Marle, Vera I. Slaveykova, Kristin Schirmer, Wei Liu

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Metal-based nanoparticles (NPs) are considered detrimental to aquatic organisms due to their potential accumulation. However, little is known about the mechanisms underlying these effects and their species-specificity. Here, we used stable silver (Ag) NPs (20 nm, from 10 to 500 μg/L) with a low dissolution rate (≤2.4%) to study the bioaccumulation and biological impacts in two freshwater gastropods: Lymnaea stagnalis and Planorbarius corneus. No mortality was detected during the experiments. Ag bioaccumulation showed a dose-related increase with an enhanced concentration in both species after 7d exposure. L. stagnalis displayed a higher accumulation for AgNPs than P. corneus (e.g., up to 18- and 15-fold in hepatopancreas and hemolymph, respectively), which could be due to the more active L. stagnalis having greater contact with suspended AgNPs. Furthermore, the hepatopancreas and stomach were preferred organs for bioaccumulation compared to the kidney, mantle and foot. Regarding biological responses, the hemolymph rather than hepatopancreas appeared more susceptible to oxidative stress elicited by AgNPs, as shown by significantly increasing lipid peroxidation (i.e., formation of malondialdehyde). Neurotoxicity was detected in L. stagnalis when exposed to high concentrations (500 μg/L). Comparison with impacts elicited by dissolved Ag revealed that the effects observed on AgNPs exposure were mainly attributable to NPs. These results highlighted the relationship between the physiological traits, bioaccumulation, and toxicity responses of these two species to AgNPs and demonstrated the necessity of species-specificity considerations when assessing the toxicity of NPs.

Keywords: nanotoxicity, freshwater gastropods, species-specificity, metals, physiological traits

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Authors: M. J. Kim, D. B. Lee

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Centrifugal casting is a metal casting method that uses forces make by centripetal acceleration to distribute molten material in mold. Centrifugal cast parts manufactured in industry contain gas pipes and water supply lines, moreover rings, turbocharger, bushings, brake drums. Turbochargers were exposed to exhaust temperatures of 900-1050°C require a material for the corrosion resistance that will withstand such high component temperatures during the entire service life of the vehicle. Hence, the study of corrosion resistance for turbocharger is important for practical application. DIN1.4091 steels were used widely. The DIN1.4091 steels whose compositions were Fe-34.4Cr-14.5Ni-2.5Mo-0.4W-0.4Mn-0.5Si-(0.009 or 0.35)S (wt.%) were centrifugally cast, and oxidized at 900°C for 50-200 h in order to find the effect of sulfur on the high-temperature oxidation of Fe-34.4Cr-14.5Ni-2.5Mo-0.4W-0.4Mn-0.5Si-(0.009 or 0.35)S (wt.%) alloys. These alloys formed oxide scales that consisted primarily of Cr₂O₃ as the major oxide and Cr₂MnO₄ as the minor one through preferential oxidation of Cr and Mn. Cr formed a thin CrOx oxide film on the surface to prevent further oxidation, and when it is added more than 20%, the sulphide decreased corrosion rate. The high affinity of Mn with S, led to the formation of scattered MnS inclusions, particularly in the 0.35S-containing cast alloy. Sulfur was harmful to the oxidation resistance because it deteriorated the scale/alloy adherence so as to accelerate the adherence and compactness of the formed scales. Acknowledgement: This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2016R1A2B1013169).

Keywords: centrifugal casting, turbocharger, sulfur, oxidation, Fe-34.4Cr-14.5Ni alloy

Procedia PDF Downloads 199

Authors: Xinyuan Zou, Qihui Tang, Shujian Wang, Yulin Huang, Jie Gui, Xiangping Liu, Gang Liu, Yanqiang Tao

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Childhood trauma can have a long-lasting influence on individuals and contribute to mental disorders, including depression and anxiety. The current study aimed to explore the symptomatic and developmental patterns of depression, anxiety, and stress among adolescents who have suffered from childhood trauma. A total of 3,598 college students (female = 1,617 (44.94%), Mean Age = 19.68, SD Age = 1.35) in China completed the Childhood Trauma Questionnaire (CTQ) and the Depression, Anxiety, and Stress Scales (DASS-21), and 2,337 participants met the selection standard based on the cut-off scores of the CTQ. The symptomatic network and directed acyclic graph (DAG) network approaches were used. The results revealed that males reported experiencing significantly more physical abuse, physical neglect, emotional neglect, and sexual abuse compared to females. However, females scored significantly higher than males on all items of DASS-21, except for “Worthless”. No significant difference between the two genders was observed in the network structure and global strength. Meanwhile, among all participants, “Down-hearted” and “Agitated” appeared to be the most interconnected symptoms, the bridge symptoms in the symptom network, as well as the most vital symptoms in the DAG network. Apart from that, “No-relax” also served as the most prominent symptom in the DAG network. The results suggested that intervention targeted at assisting adolescents in developing more adaptive coping strategies with stress and regulating emotion could benefit the alleviation of comorbid depression, anxiety, and stress.

Keywords: symptom network, childhood trauma, depression, anxiety, stress

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Authors: Mohammad Bagher Heidari, Hefzollah Mohammadian

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TETRA (Terrestrial Trunked Radio) is a digital radio communication standard, which has been implemented in several different parts of the gas refinery ninth (phase 12th) by South Pars Gas Complex. Studies on possible impacts on the users' health considering different exposure conditions are missing. Objectives: To investigate possible acute effects of electromagnetic fields (EMF) of two different levels of TETRA hand-held transmitter signals on cognitive function and well-being in healthy young males. Methods: In the present double-blind cross-over study possible effects of short-term (2.5 h) EMF exposure of handset-like signals of TETRA (450 - 470 MHz) were studied in 30 healthy male participants (mean ± SD: 25.4 ±2.6 years). Individuals were tested on nine study days, on which they were exposed to three different exposure conditions (Sham, TETRA 1.5 W/kg and TETRA 10.0 W/kg) in a randomly assigned and balanced order. Participants were tested in the afternoon at a fixed timeframe. Results: Attention remained unchanged in two out of three tasks. In the working memory, significant changes were observed in two out of four subtasks. Significant results were found in 5 out of 35 tested parameters, four of them led to an improvement in performance. Mood, well-being and subjective somatic complaints were not affected by TETRA exposure. Conclusions: The results of the present study do not indicate a negative impact of a short-term EMF- effect of TETRA on cognitive function and well-being in healthy young men.

Keywords: TETRA (terrestrial trunked radio), electromagnetic fields (EMF), mobile telecommunication health research (MTHR), antenna

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Authors: Alba Luna Jimenez, Maria Dolores Hernando

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The administration of veterinary treatments at higher doses than the recommended Varroa mite control in beehive matrices has the potential to generate residues in the honeybee colony and in the derived products for consumption. Honeybee colonies can also be indirectly exposed to residues of plant protection products when foraging in crops, wildflowers near the crops, or in urban gardens just after spraying. The study evaluates the presence of both types of residues, veterinary treatments, and pesticides in beeswax, bee bread, and honey. The study was carried out in apiaries located in agricultural zones and forest areas in Andalusia, Spain. Up to nineteen residues were identified above LOQ using gas chromatography-triple quadrupole-mass spectrometry analysis (GC-MS/MS). Samples were extracted by a modified QuEChERs method. Chlorfenvinphos was detected in beeswax and bee bread despite its use is not authorized for Varroa mite control. Residues of fluvalinate-tau, authorized as veterinary treatment, were detected in most of the samples of beeswax and bee bread, presumably due to overdose or also to its potential for accumulation associated with its marked liposolubility. Residues of plant protection products were also detected in samples of beeswax and bee bread. Pesticide residues were detected above the LOQ that was established at 5 µg.kg⁻¹, which is the minimum concentration that can be quantified with acceptable accuracy and precision, as described in the European guidelines for pesticide residue analysis SANTE/11945/2015. No residues of phytosanitary treatments used in agriculture were detected in honey.

Keywords: honeybee colony, mass spectrometry analysis, pesticide residues, Varroa destructor, veterinary treatment

Procedia PDF Downloads 161

Authors: Tzyy-Rong Jinn, Sheng-Kuo Hsieh, Yi-Ching Chung, Feng-Chia Hsieh

Abstract:

In this study, we attempted to develop a recombinant oleosin-based fusion expression strategy in Escherichia coli (E. coli) and coupled with the artificial oil bodies (AOB)-cyanogen bromide technology platform to produce bioactive mastoparan B (MP-B). As reported, the oleosin in AOB system plays a carrier (fusion with target protein), since oleosin possess two amphipathic regions (at the N-terminus and C-terminus), which result in the N-terminus and C-terminus of oleosin could be arranged on the surface of AOB. Thus, the target protein fused to the N-terminus or C-terminus of oleosin which also is exposed on the surface of AOB, and this process will greatly facilitate the subsequent separation and purification of target protein from AOB. In addition, oleosin, a unique structural protein of seed oil bodies, has the added advantage of helping the fused MP-B expressed in inclusion bodies, which can protect from proteolytic degradation. In this work, MP-B was fused to the C-terminus of oleosin and then was expressed in E. coli as an insoluble recombinant protein. As a consequence, we successfully developed a reliable recombinant oleosin-based fusion expression strategy in Escherichia coli and coupled with the artificial oil bodies (AOB)-cyanogen bromide technology platform to produce the small peptide, MP-B. Take together, this platform provides an insight into the production of active MP-B, which will facilitate studies and applications of this peptide in the future.

Keywords: artificial oil bodies, Escherichia coli, Oleosin-fusion protein, Mastoparan-B

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Authors: Asim Abbasi, Muhammad Sufyan

Abstract:

The present experiment was carried out to examine the effects of silicon dioxide on tritrophic interaction of cotton, whitefly, and the predator Chrysoperla carnea. Population of whitefly was maintained on silicon treated and non-treated cotton for two generations in greenhouse net cages exposed to outside temperature and luminosity. The cotton was treated with silicon dioxide twice after 15 days intervals with 200 ppm concentration. A stock rearing of the natural predator was developed in the laboratory conditions. In the bioassay eggs of the predator all at the same age were individualized in glass petri plates that will be pierced with a pin to allow aeration and maintained in an incubator at 28 ± 2°C, 70 ± 10% relative humidity and 12h photo phase. Population of whitefly stayed on silicon treated, and non-treated cotton were offered to newly hatched chrysopid larvae until the end of the larval stage, assuring a permanent supply. Feeding preference of C. carnea along with longevity, survival of each instar larvae, pupation, adult emergence, and fecundity was checked. The results revealed that there was no significant difference in the feeding preference of C. carnea among both treatments. Durations of 1st and 2nd larval instar were also at par in both treatments. However overall longevity and adult emergence were a bit lower in silicon treated whitefly treatment. This may be due to the fact that silicon reduces the nutritional quality of host because of reduced whitefly feeding on silicon treated cotton. No significant difference in 1st and 2nd larval instars and then increased larval duration in later instars suggested that the effect of silicon treated host should be checked on more than 1 generation of C. carnea to get better findings.

Keywords: Chrysoperla carnea, silicon, tritrophic, whitefly

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Authors: Fadlan Atmaja Nursiwan, Ugi Kurnia Gusti

Abstract:

Garba Hill, located in Tekana Village, South Sumatera Province is comprised to South Sumatra Basin and classified as back arc basin. This area is entered as an active margin of Sundaland which experiences subduction several times since Mesozoic to recent time. The traces of Mesozoic subduction in the southern part of Sumatra island are exposed in Garba Hill area. The aim of this investigation is to study the tectonic changes in the first phase in Mesozoic era at the active margin of Sundaland which causes the rocks assemblage in Garba hill consist of continental and oceanic plate rocks which the correlation between those rocks show indistinct relation. This investigation is conducted by field observation in Tekana village and Lubar Village, Muara Dua, South Sumatra along with laboratory analysis included fossil and geochemistry analysis of radiolarian chert, petrography analysis of granite and basalt, and structural modelling. Fossil and geochemistry analysis of radiolarian chert and geochemistry of granite rocks shown the relation between the two rocks and Mesozoic subduction of Woyla terrane on western margin of Sundaland. Petrography analysis from granite and basalt depict the tectonic affinity of rocks. Moreover, structural analysis showed the changes of lineation direction from N-S to WNW-ESE.

Keywords: granite, mesozoic, radiolarian, subduction traces

Procedia PDF Downloads 338

Authors: Suk Woo Hong, Chang Sung Seok, Jae Mean Koo

Abstract:

Recently, the welding is widely used in modern industry for joining the structures. However, the waterworks pipes are exposed to the fatigue load by cars, earthquake and etc because of being buried underground. Moreover, the residual stress exists in weld zone by welding process and it is well known that the fatigue life of welded structures is degraded by residual stress. Due to such reasons, the crack can occur in the weld zone of pipeline. In this case, The ground subsidence or sinkhole can occur, if the soil and sand are washed down by fluid leaked from the crack of water pipe. These problems can lead to property damage and endangering lives. For these reasons, the estimation of fatigue characteristics for water pipeline weld zone is needed. Therefore, in this study, for fatigue characteristics estimation of spiral welded waterworks pipe, ASTM standard specimens and Curved Plate specimens were collected from the spiral welded waterworks pipe and the fatigue tests were performed. The S-N curves of each specimen were estimated, and then the fatigue life of weldment Curved Plate specimen was predicted by theoretical and analytical methods. After that, the weldment Curved Plate specimens were collected from the pipe and verification fatigue tests were performed. Finally, it was verified that the predicted S-N curve of weldment Curved Plate specimen was good agreement with fatigue test data.

Keywords: spiral welded pipe, prediction fatigue life, endurance limit modifying factors, residual stress

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Authors: Inemesit Akpan Umoren, Aniekan James Akpan

Abstract:

Media practitioners and information managers have often erroneously operated on the premise that media messages are received as disseminated to the extent that audiences of whatever background assimilate the content uniformly. This does not subsist since media audiences are often segmented in terms of educational level, social category, place of residence, gender, among others. While those who are highly educated, live in urban areas and are of highest standing are more likely to have direct access to the media, those in the rural areas and of low education and standing, may not have direct or easy access. These, therefore, informed the study to establish the consumption patterns of mass media products by residents of rural communities in south-south, Nigeria. The study, which was anchored on the multi-step flow and social categories theories, adopted a survey research design and a sample of 383 using Mayer’s 1979 guide drawn from nine rural communities in the south-south, Nigeria states of Akwa Ibom, Rivers and Edo. Findings among others showed that while a negligible percentage is highly exposed to media messages of all types, a greater member depend on opinion leaders, social groups, drinking joints, among other such for filtered content. It was concluded that since rural or community media organizations are very vital in ensuring media content get to all audience without necessarily being passing through intermediaries. Among the recommendations was that information managers and media organizations should always have in mind the ruralites while packaging their contents even in the mainstream media.

Keywords: consumption, media, media product, pattern

Procedia PDF Downloads 144

Authors: Hatice Özbek, Caner Çil, Ahmet Rodoplu

Abstract:

Automotive lighting is the leading function in the configuration of vehicle architecture. Especially headlights and taillights from external lighting functions are among the structures that determine the stylistic character of the vehicle. At the same time, the fact that lighting functions are related to many other functions brings along difficulties in design. Customers expect maximum quality from the vehicle. In these circumstances, it is necessary to make designs that aim to keep the performance of bulbs with limited working lives at the highest level. With this study, the factors that influence the working lives of filament lamps were examined and bulb explosions that can occur sooner than anticipated in the future were prevented while the vehicle was still in the design phase by determining the relations with electrical, dynamical and static variables. Especially the filaments of the bulbs used in the front lighting of the vehicle are deformed in a shorter time due to the high voltage requirement. In addition to this, rear lighting lamps vibrate as a result of the tailgate opening and closing and cause the filaments to be exposed to high stress. With this study, the findings that cause bulb explosions were evaluated. Among the most important findings: 1. The structure of the cables to the lighting functions of the vehicle and the effect of the voltage values are drawn; 2. The effect of the vibration to bulb throughout the life of the vehicle; 3 The effect of the loads carried to bulb while the vehicle doors are opened and closed. At the end of the study, the maximum performance was established in the bulb lifetimes with the optimum changes made in the vehicle architecture based on the findings obtained.

Keywords: vehicle architecture, automotive lighting functions, filament lamps, bulb lifetime

Procedia PDF Downloads 153

Authors: Assel Thami Lahlou, Soufiane Stouti, Ismail Lagrat, Hamid Mounir, Oussama Bouazaoui

Abstract:

The purpose of this research work is to predict the helicopter from stalling by finding the minimum and maximum values that the pitch angle can take in order to fly in a hover state condition. The stall of a helicopter in hover occurs when the pitch angle is too small to generate the thrust required to support its weight or when the critical angle of attack that gives maximum lift is reached or exceeded. In order to find the minimum pitch angle, a 3D CFD simulation was done in this work using ANSYS FLUENT as the CFD solver. We started with a small value of the pitch angle θ, and we kept increasing its value until we found the thrust coefficient required to fly in a hover state and support the weight of the helicopter. For the CFD analysis, the Multiple Reference Frame (MRF) method with k-ε turbulent model was used to study the 3D flow around the rotor for θmin. On the other hand, a 2D simulation of the airfoil NACA 0012 was executed with a velocity inlet Vin=ΩR/2 to visualize the flow at the location span R/2 of the disk rotor using the Spallart-Allmaras turbulent model. Finding the critical angle of attack at this position will give us the ability to predict the stall in hover flight. The results obtained will be exposed later in the article. This study was so useful in analyzing the limitations of the helicopter’s main rotor and thus, in predicting accidents that can lead to a lot of damage.

Keywords: aerodynamic, CFD, helicopter, stall, blades, main rotor, minimum pitch angle, maximum pitch angle

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Authors: Mohammad A. Khasawneh

Abstract:

Asphalt concrete pavements gradually lose their skid resistance causing safety problems especially under wet conditions and high driving speeds. In order to enact the actual field polishing and wearing process of asphalt pavement surfaces in a laboratory setting, several laboratory-scale accelerated polishing devices were developed by different agencies. To mimic the actual process, friction and texture measuring devices are needed to quantify surface deterioration at different polishing intervals that reflect different stages of the pavement life. The test could still be considered lengthy and to some extent labor-intensive. Therefore, there is a need to come up with another method that can assist in investigating the bituminous pavement surface characteristics in a practical and time-efficient test procedure. The purpose of this paper is to utilize a well-developed image analysis technique to characterize asphalt pavement surfaces without the need to use conventional friction and texture measuring devices in an attempt to shorten and simplify the polishing procedure in the lab. Promising findings showed the possibility of using image analysis in lieu of the labor-sensitive-variable-in-nature friction and texture measurements. It was found that the exposed aggregate surface area of asphalt specimens made from limestone and gravel aggregates produced solid evidence of the validity of this method in describing asphalt pavement surfaces. Image analysis results correlated well with the British Pendulum Numbers (BPN), Polish Values (PV) and Mean Texture Depth (MTD) values.

Keywords: friction, image analysis, polishing, statistical analysis, texture

Procedia PDF Downloads 306