Search results for: Increased intrauterine pressure

Authors: Frederick Anlimah, Vinod Gopaldasani, Catherine MacPhail, Brian Davies

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The construction industry, particularly tunnel construction, exposes workers to respirable crystalline silica (RCS), which can cause incurable illnesses such as silicosis and lung cancer. Despite various control measures, exposures remain inadequately controlled. This research aimed to examine what workers on a tunnelling project in Australia think should be done to reduce exposure to dust to protect them from RCS exposure. A qualitative research approach consisting of interviews and focus group discussions was employed for this research. The preliminary analysis of the data reveals a diverse array of solutions proposed to address the different sociotechnical factors that present challenges for effectively reducing dust exposure. Solutions are proposed to address challenges such as cost, time pressure, low-risk perception, inadequate awareness, inadequate enforcement and compliance with personal protective equipment. The findings highlight the need to make dust control a level playing field for all contractors during the bidding process, with more collaboration and enforcement after the signing of contracts. The research highlights that although improvements have been made in the past years regarding dust controls, many opportunities exist to reduce worker exposure to RCS.

Keywords: tunnel, respirable crystalline silica, RCS, dust exposure, personal protective equipment, worker perspectives

Procedia PDF Downloads 61

Authors: Rayhaneh Amooaghaie, Masoomeh Nabaei

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In this study, 200 µM Cd reduced relative seed germination, root elongation tolerance and seed germination tolerance index of Catharanthus roseus. The melatonin improved seed germination, germination velocity, seedling length and vigor index under Cd stress in a dose-dependent manner and the maximum biological responses obtained by 100 μM melatonin. However, 200-400 μM melatonin and 400 μM SNP had negative effects that evidenced as lower germination indices and poor establishment of seedlings. The cadmium suppressed amylase activity and contents of soluble and reducing sugars in germinating seeds, thereby reduced seed germination and subsequent seedling growth whereas increased electrolyte leakage. These Cd-induced inhibitory effects were ameliorated by melatonin.

Keywords: cadmium, Catharanthus roseus, melatonin, seed germination

Procedia PDF Downloads 164

Authors: C. Nobre, C. C. Castro, A.-L. Hantson, J. A. Teixeira, L. R. Rodrigues, G. De Weireld

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Fructo-oligosaccharides (FOS) are produced from sucrose by Aureobasidium pullulans in yields between 40-60% (w/w). To increase the amount of FOS it is necessary to remove the small, non-prebiotic sugars, present. Two methods for producing high-purity FOS have been developed: the use of microorganisms able to consume small saccharides; and the use of continuous chromatography to separate sugars: simulated moving bed (SMB). It is herein proposed the combination of both methods. The aim of this study is to optimize the composition of the fermentative broth (in terms of salts and sugars) that will be further purified by SMB. A yield of 0.63 gFOS.g Sucrose-1 was obtained with A. pullulans using low amounts of salts in the initial fermentative broth. By removing the small sugars, Saccharomyces cerevisiae and Zymomonas mobilis increased the percentage of FOS from around 56.0% to 83% (w/w) in average, losing only 10% (w/w) of FOS during the recovery process.

Keywords: fructo-oligosaccharides, microbial treatment, Saccharomyces cerevisiae, Zymomonas mobilis

Procedia PDF Downloads 294

Authors: Mohammadjavad Yaghoubi, Arul Arulrajah, Mahdi M. Disfani, Suksun Horpibulsuk, Myint W. Bo, Stephen P. Darmawan

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This paper investigates the changes in the strength development of a high water content soft soil stabilised with alkaline activation of fly ash (FA) to use in deep soil mixing (DSM) technology. The content of FA was 20% by dry mass of soil, and the alkaline activator was sodium silicate (Na2SiO3). Samples were cured for 3, 7, 14, 28 and 56 days to evaluate the effect of curing time on strength development. To study the effect of adding slag (S) to the mixture on the strength development, 5% S was replaced with FA. In addition, the effect of the initial unit weight of samples on strength development was studied by preparing specimens with two different static compaction stresses. This was to replicate the field conditions where during implementing the DSM technique, the pressure on the soil while being mixed, increases with depth. Unconfined compression strength (UCS), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) tests were conducted on the specimens. The results show that adding S to the FA based geopolymer activated by Na2SiO3 decreases the strength. Furthermore, samples prepared at a higher unit weight demonstrate greater strengths. Moreover, samples prepared at lower unit weight reached their final strength at about 14 days of curing, whereas the strength development continues to 56 days for specimens prepared at a higher unit weight.

Keywords: alkaline activation, curing time, fly ash, geopolymer, slag

Procedia PDF Downloads 330

Authors: Sulaiman B. Ali Alharbi, Bassam H. Mashat, Naif Abdullah Al-Harbi, Milton Wainwright, Abeer S. Aloufi, Sulamain Alnaimat

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Bismuth salicylate was found to inhibit the growth of a range of bacteria and yeast, Candida albican. In general the growth of bacteria did not result in the increase in bismuth solubilisation, in contrast, bismuth solubilisation increased following the growth of C. albicans. A significant increase in the biomass (dry weight) of Aspergillus niger and Aspergillus oryzae occurred in vitro when these fungi were grown in the presence of bismuth salicylate. Biomass increase occurred over a range of bismuth compound additions, which in the case of A. oryzae was associated with the increase in the solubilisation of the insoluble bismuth compounds.

Keywords: bacterial inhibition, fungal growth stimulation, medical uses of bismuth, yeast inhibition

Procedia PDF Downloads 328

Authors: M. Bidi, H. Akhbari, S. Eslami, A. Bakhtiari

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Due to the high potential of solar energy utilization in Iran, development of related technologies is of great necessity. Linear parabolic collectors are among the most common and most efficient means to harness the solar energy. The main goal of this paper is design and construction of a parabolic trough collector to produce hot water and steam in Tehran. To provide precise and practical plans, 3D models of the collector under consideration were developed using Solidworks software. This collector was designed in a way that the tilt angle can be adjusted manually. To increase concentraion ratio, a small diameter absorber tube is selected and to enhance solar absorbtion, a shape of U-tube is used. One of the outstanding properties of this collector is its simple design and use of low cost metal and plastic materials in its manufacturing procedure. The collector under consideration was installed in Shahid Beheshti University of Tehran and the values of solar irradiation, ambient temperature, wind speed and collector steam production rate were measured in different days and hours of July. Results revealed that a 1×2 m parabolic trough collector located in Tehran is able to produce steam by the rate of 300ml/s under the condition of atmospheric pressure and without using a vacuum cover over the absorber tube.

Keywords: desalination, parabolic trough collector, direct steam production, solar water heater, design and construction

Procedia PDF Downloads 301

Authors: To Que Nga

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College-bound males may experience considerable maladjustment during the crucial developmental time between high school and college. By participating in stereotypically male actions, men may feel under pressure to "prove" their masculinity, which may be harmful to their general well-being. Although adherence to multidimensional male standards has been linked to worse mental health, no research has considered the impact of these norms on college men's potential depressive symptoms. A viable theoretical framework to explain within-group variation in depression symptomatology can be provided by longitudinally examining college men's adherence to multidimensional masculine standards. An overview of recent studies on the connection between masculine norms and depression among Vietnamese men in college is given in this article. 208 males from different Hanoi colleges were included in the study. Male norms were evaluated at the start of their first semester. Six months following the initial round of data collection, depressive symptomatology was evaluated. Men who approved the male norms of Self-Reliance, Playboy, and Power Over Women showed a positive relationship between masculine norms and depression scores. The impact of multidimensional masculine norms on college men's depressive symptomatology was first examined in this study. The findings imply that professionals who interact with males should think about determining whether their clients conform to particular masculine standards and investigating how these could be affecting their present mental health.

Keywords: masculinity, conformity to masculinity, depression, psycho-social issues, men, college

Procedia PDF Downloads 55

Authors: Tejeet Singh, Virat Khanna

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Composite materials have drawn considerable attention of engineers due to their light weight and application at high thermo-mechanical loads. With regard to the prediction of the life of high temperature structural components like rotating cylinders and the evaluation of their deterioration with time, it is essential to have a full knowledge of creep characteristics of these materials. Therefore, in the present study the secondary stage creep stresses and strain rates are estimated in thick-walled composite cylinders subjected to rotary inertia at different angular speeds. The composite cylinder is composed of aluminum matrix (Al) and reinforced with silicon carbide (SiC) particles which are uniformly mixed. The creep response of the material of the cylinder is described by threshold stress based creep law. The study indicates that with the increase in angular speed, the radial, tangential, axial and effective stress increases to a significant value. However, the radial stress remains zero at inner radius and outer radius due to imposed boundary conditions of zero pressure. Further, the stresses are tensile in nature throughout the entire radius of composite cylinder. The strain rates are also influenced in the same manner as that of creep stresses. The creep rates will increase significantly with the increase of centrifugal force on account of rotation.

Keywords: composite, creep, rotating cylinder, angular speed

Procedia PDF Downloads 433

Authors: Ehsan Sakhaei, Ali Taherabadi

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In this study, an aft sweep wing with specific characteristic feature was analysis with CFD method in Fluent software. In this analysis wings aerodynamic coefficient was calculated in different rake angle and wing lift curve slope to rake angle was achieved. Wing section was selected among NACA airfoils version 6. The sweep angle of wing is 15 degree, aspect ratio 8 and taper ratios 0.4. Designing and modeling this wing was done in CATIA software. This model was meshed in Gambit software and its three dimensional analysis was done in Fluent software. CFD methods used here were based on pressure base algorithm. SIMPLE technique was used for solving Navier-Stokes equation and Spalart-Allmaras model was utilized to simulate three dimensional wing in air. Roskam method is one of the common and most used methods for determining aerodynamics parameters in the field of airplane designing. In this study besides CFD analysis, an advanced aircraft analysis was used for calculating aerodynamic coefficient using Roskam method. The results of CFD were compared with measured data acquired from Roskam method and authenticity of relation was evaluated. The results and comparison showed that in linear region of lift curve there is a minor difference between aerodynamics parameter acquired from CFD to relation present by Roskam.

Keywords: aft sweep wing, CFD method, fluent, Roskam, Spalart-Allmaras model

Procedia PDF Downloads 496

Authors: M. Ezkurra, J. A. Esnaola, M. Martinez-Agirre, U. Etxeberria, U. Lertxundi, L. Colomo, M. Begiristain, I. Zurutuza

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Butterfly valves are widely used industrial piping components as on-off and flow controlling devices. The main challenge in the design process of this type of valves is the correct dimensioning to ensure proper mechanical performance as well as to minimise flow losses that affect the efficiency of the system. Butterfly valves are typically dimensioned in a closed position based on mechanical approaches considering uniform hydrostatic pressure, whereas the flow losses are analysed by means of CFD simulations. The main limitation of these approaches is that they do not consider either the influence of the dynamics of the manoeuvring stage or coupled phenomena. Recent works have included the influence of the flow on the mechanical behaviour for different opening angles by means of one-way FSI approach. However, these works consider steady-state flow for the selected angles, not capturing the effect of the transient flow evolution during the manoeuvring stage. Two-way FSI modelling approach could allow overcoming such limitations providing more accurate results. Nevertheless, the use of this technique is limited due to the increase in the computational cost. In the present work, the applicability of FSI one-way and two-way approaches is evaluated for the analysis of butterfly valves, showing that not considering fluid-structure coupling involves not capturing the most critical situation for the valve disc.

Keywords: butterfly valves, fluid-structure interaction, one-way approach, two-way approach

Procedia PDF Downloads 154

Authors: Nagri Sateesh, Kundavarapu Vengalrao, Kopparthi Phaneendra Kumar

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Vacuum assisted resin transfer molding (VARTM) is one of the manufacturing technique that is viable for production of fiber reinforced polymer composite components suitable for aerospace, marine and commercial applications. However, the repeatable quality of the product can be achieved by critically fixing the process parameters such as Vacuum Pressure (VP) and permeability of the preform. The present investigation is aimed at studying the effect of permeability for production of Glass Fiber Reinforced Plastic (GFRP) components with consistent quality. The VARTM mould is made with an acrylic transparent top cover to observe and record the resin flow pattern. Six layers of randomly placed glass fiber under five different vacuum pressures VP1 = 0.013, VP2 = 0.026, VP3 = 0.039, VP4 = 0.053 and VP5 = 0.066 MPa were studied. The laminates produced by this process under the above mentioned conditions were characterized with ASTM D procedures so as to study the effect of these process parameters on the quality of the laminate. Moreover, as mentioned there is a considerable effect of permeability on the impact strength and the void content in the laminates under different vacuum pressures. SEM analysis of the impact tested fractured GFRP composites showed the bonding of fiber and matrix.

Keywords: permeability, vacuum assisted resin transfer molding (VARTM), ASTM D standards, SEM

Procedia PDF Downloads 143

Authors: Azzeddine Atibi, Sara Atibi, Salim Ahmed, Khadija El Kabab

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In an educational context where innovation holds a predominant position, political discourses and pedagogical practices are increasingly oriented toward this concept. Innovation has become a benchmark value, gradually replacing the notion of progress. This term is omnipresent in discussions among policymakers, administrators, and academic researchers. The pressure to innovate impacts all levels of education, influencing institutional and educational policies, training objectives, and teachers' pedagogical practices. Higher education and continuing education sectors are not exempt from this trend. These sectors are compelled to transform to attract and retain an audience whose behaviors and expectations have significantly evolved. Indeed, the employability of young graduates has become a crucial issue, prompting us to question the effectiveness of various pedagogical methods in meeting this criterion. In this article, we propose to thoroughly examine the relationship between pedagogical methods employed in different fields of higher education and the acquisition of interpersonal skills, or "soft skills". Our aim is to determine to what extent these methods contribute to better-preparing students for the professional world. We will analyze how innovative pedagogical approaches can enhance the acquisition of soft skills, which are essential for the professional success of young graduates.

Keywords: educational context, innovation, higher education, soft skills, pedagogical practices, pedagogical approaches

Procedia PDF Downloads 16

Authors: Lebea Nthunya, Arne Verliefde, Bhekie Mamba, Sabelo Mhlanga

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A study aimed at developing membrane distillation (MD) processes that can be used for brackish/saline water purification will be presented. MD is a membrane-based technology that presents a possibility to counteract challenges associated with pressure driven membranes at high separation efficiencies. Membrane distillation membranes (MDM) are affected by wettability and fouling. Wetting inside the pores of the membrane is elevated by the hydrophilic characteristic of the membrane, while fouling is mostly induced by the hydrophobic-hydrophobic interaction of pollutants and the surface of the hydrophobic membranes, hence block the pores of the membranes. These properties are not desirable. As such, a carefully designed polyvinylidene fluoride (PVDF) MDM composed of a super-hydrophobic modified backbone and a super-hydrophilic thin layer has been developed to concurrently overcome these challenges. The membranes were characterized using contact angle measurements to confirm their hydrophobicity/hydrophilicity. SEM and SAXS were used to study the morphology and pore distribution on the surface of the membrane. The contact angles of the active surface ≤ 30º and that of the backbone ≥ 140º has thus revealed that the active surface was highly hydrophilic while the backbone was highly hydrophobic. The SEM and the SAXS results have also confirmed that the membranes are highly porous. These materials demonstrated a potential to remove salts from water at high efficiencies.

Keywords: membrane distillation, modification, energy efficiency, desalination

Procedia PDF Downloads 243

Authors: Rajat Mittal, Harshal Raut, Jung Hee Seo

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Wave-assisted propulsion (WAP) systems convert wave energy into thrust using elastically mounted hydrofoils. We employ sharp-interface immersed boundary simulations to examine the effect of two key parameters on the flow physics, the fluid-structure interaction, as well as thrust performance of these systems - the stiffness of the torsional spring and the location of the rotational center. The variation in spring stiffness leads to different amplitude of pitch motion, phase difference with respect to heaving motion and thrust coefficient and we show the utility of ‘maps’ of energy exchange between the flow and the hydrofoil system, as a way to understand and predict this behavior. The Force Partitioning Method (FPM) is used to decompose the pressure forces into individual components and understand the mechanism behind increase in thrust. Next, a scaling law is presented for the thrust coefficient generated by heaving and pitching foil. The parameters within the scaling law are calculated based on direct-numerical simulations based parametric study utilized to generate the energy maps. The predictions of the proposed scaling law are then compared with those of a similar model from the literature, showing a noticeable improvement in the prediction of the thrust coefficient.

Keywords: propulsion, flapping foils, hydrodynamics, wave power

Procedia PDF Downloads 46

Authors: Muhammad Azhar, Arshad Hussain

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Vehicular emissions have increased in recent years due to rapid growth in world traffic resulting in an increase in associated problems such as air pollution and climate change, therefore it’s necessary to control vehicle emissions. This study looks at the effect of road maintenance on vehicle emissions. The Highway Development and Management Tool (HDM-4) was used to find the effect of road maintenance on vehicle emissions. Key data collected were traffic volume and composition, vehicle characteristics, pavement characteristics and climate data of the study area. Two options were analysed using the HDM-4 software; the base case or do nothing while the second is overlay maintenance. The study also showed a strong correlation between average roughness and yearly emission levels in both the alternatives. Finally, the study showed that proper maintenance reduces the roughness and emissions.

Keywords: vehicle emissions, road roughness, IRI, maintenance, HDM-4, CO2

Procedia PDF Downloads 252

Authors: M. Solairaju, Nithin J. Thomas, S. Ganesan

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Each and every rotating part of a machine element consists of bearings within its structure. In particular, the rolling element bearings such as cylindrical roller bearing and deep groove ball bearings are frequently used. Improper handling, excessive loading, improper lubrication and sealing cause bearing damage. Hence health monitoring of bearings is an important aspect for radiation pattern of bearing vibration is computed using the dipole model. Sound pressure level for defect-free and race defect the prolonged life of machinery and auto motives. This paper presents modeling and analysis of Acoustic response of deep groove ball bearing with localized race defects. Most of the ball bearings, especially in machine tool spindles and high-speed applications are pre-loaded along an axial direction. The present study is carried out with axial preload. Based on the vibration response, the orbit motion of the inner race is studied, and it was found that the oscillation takes place predominantly in the axial direction. Simplified acoustic is estimated. Acoustic response shows a better indication in identifying the defective bearing. The computed sound signal is visualized in diagrammatic representation using Symmetrised Dot Pattern (SDP). SDP gives better visual distinction between the defective and defect-free bearing

Keywords: bearing, dipole, noise, sound

Procedia PDF Downloads 284

Authors: Ojiegbe Ikenna Nathan

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Obesity is a medical condition in which excess body fat has accumulated to the extent that it leads to reduced life expectancy and or increased health problems. Obesity as a worldwide problem is seen clustered in the families and it moves from generation to generation. It causes some disabilities, mortality and morbidity if left unattended to. The predisposing factors to obesity are either genetic or environment in origin. Nevertheless, the main predisposing factor to obesity is the excessive consumption of food rich in low-density lipoprotein (LDL) such as organ meats, saturated fats etc. This low-density lipoprotein causes an increase in adipose tissue and complicates to obesity. There are varieties of obesity which one needs to take appropriate measures to avoid; such as android, gynoid and morbid obesity. Nonetheless, studies have shown that there is hope for the obese individuals, despite the cause, type and degree of their obesity. This is through the use of the different available treatment measures which increase in physical activities, caloric restrictions, drug therapy and surgical intervention.

Keywords: low-density, lipoprotein, culprit, obesity

Procedia PDF Downloads 388

Authors: Yu-Chen Chang, Yen-Ping Peng, Wei-Yu Chen, Ku-Fan Chen

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Contamination of soil and groundwater has become a serious and widespread environmental problem. In this study, sustained-release persulfate tablets were developed using persulfate powder and a modified cellulose binder for organic-contaminated groundwater remediation. Conventional cement-based persulfate-releasing materials were also synthesized for the comparison. The main objectives of this study were to: (1) evaluate the release rates of the remedial tablets; (2) obtain the optimal formulas of the tablets; and (3) evaluate the effects of the tablets on the subsurface environment. The results of batch experiments show that the optimal parameter for the preparation of the persulfate-releasing tablet was persulfate:cellulose = 1:1 (wt:wt) with a 5,000 kg F/cm2 of pressure application. The cellulose-based persulfate tablet was able to release 2,030 mg/L of persulfate per day for 10 days. Compared to cement-based persulfate-releasing materials, the persulfate release rates of the cellulose-based persulfate tablets were much more stable. Moreover, since the tablets are soluble in water, no waste will be produced in the subsurface. The results of column tests show that groundwater flow would shorten the release time of the tablets. This study successfully developed unique persulfate tablets based on green remediation perspective. The efficacy of the persulfate-releasing tablets on the removal of organic pollutants needs to be further evaluated. The persulfate tablets are expected to be applied for site remediation in the future.

Keywords: sustained-release persulfate tablet, modified cellulose, green remediation, groundwater

Procedia PDF Downloads 272

Authors: Woei-Shyan Lee, Yu-Liang Chuang

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The nano-mechanical properties of as-deposited Cu/Si thin films indented to a depth of 2000 nm are investigated using a nanoindentation technique. The nanoindented specimens are annealed at a temperature of either 160 °C or 210°C, respectively. The microstructures of the as-deposited and annealed samples are then examined via transmission electron microscopy (TEM). The results show that both the loading and the unloading regions of the load-displacement curve are smooth and continuous, which suggests that no debonding or cracking occurs during nanoindentation. In addition, the hardness and Young’s modulus of the Cu/Si thin films are found to vary with the nanoindentation depth, and have maximum values of 2.8 GPa and 143 GPa, respectively, at the maximum indentation depth of 2000 nm. The TEM observations show that the region of the Cu/Si film beneath the indenter undergoes a phase transformation during the indentation process. In the case of the as-deposited specimens, the indentation pressure induces a completely amorphous phase within the indentation zone. For the specimens annealed at a temperature of 160°C, the amorphous nature of the microstructure within the indented zone is maintained. However, for the specimens annealed at a higher temperature of 210°C, the indentation affected zone consists of a mixture of amorphous phase and nanocrystalline phase. Copper silicide (η-Cu3Si) precipitates are observed in all of the annealed specimens. The density of the η-Cu3Si precipitates is found to increase with an increasing annealing temperature.

Keywords: nanoindentation, Cu/Si thin films, microstructural evolution, annealing temperature

Procedia PDF Downloads 378

Authors: Klára Gajdošíková

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The aim of this study was to examine the quiet eye method and its components using the mobile eye tracking device. Quiet eye training was proven to be beneficial for different sports, including golf. The main idea of this method is to prolong your fixations on a specific place in order to improve your performance. The shot examined in this study is called putt. Its importance is based on its role on a golf course because, many times, it is the last putt that decides whether you win or lose. Quiet eye training helps players be more focused under pressure, control their attention and overall improve their putting success. Six highly skilled golfers with a handicap ranging from - 4 to + 4, aged 23 to 26, participated in a pilot study with the usage of an eye-tracking device. The study took place in an indoor training area at the golf club Hostivař. Crosstabs showed significant differences between individuals' laterality and their gaze into AOI - areas of interest (middle part of the ball, top of the ball, bottom of the ball, back side of the ball). Statistically significant differences were also discovered between the mean fixation duration of participants with AOI on the middle part of the ball and all other AOIs. The results of this study helped us understand the examined phenomena and showed us the next aim in future quiet eye research. Future research should focus on examining a quiet eye on the golf course. Applying a quiet eye and therefore changing the way we concentrate might be beneficial for coaches and players themselves.

Keywords: eye tracking, golf, laterality, quiet eye

Procedia PDF Downloads 97

Authors: Elaheh Ezami, Behzad Mohammadian, Elham Aznab

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Health service design will need to change due to bringing in new digital health tools. This highlights the importance of innovation in adopting Health Information Technology (HIT). It can be argued that innovation in the health sector correlates with entrepreneurship. Various reasons exist for health entrepreneurs to advocate increased investment in HIT to compensate for shortcomings in the health sector and improve the quality of healthcare. Furthermore, every innovative program presents challenges and motivations for entrepreneurs that may distract or encourage the adoption of technology. Our study used a systematic literature review to identify relevant articles that defined the frustrations and promotions of using health information technology in organizations or enterprises. A meta-analysis of the articles was conducted to identify the factors driving or pulling entrepreneurs to use HIT.

Keywords: health information technology, health entrepreneurship, health enterprise, health entrepreneurs' innovation

Procedia PDF Downloads 98

Authors: Thomas Folegot, Arnaud Levaufre, Léna Bourven, Nicolas Kermagoret, Alexis Caillard, Roger Gallou

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Concern for negative impacts of anthropogenic noise on the ocean’s ecosystems has increased over the recent decades. This concern leads to a similar increased willingness to regulate noise-generating activities, of which shipping is one of the most significant. Dealing with ship noise requires not only knowledge about the noise from individual ships, but also how the ship noise is distributed in time and space within the habitats of concern. Marine mammals, but also fish, sea turtles, larvae and invertebrates are mostly dependent on the sounds they use to hunt, feed, avoid predators, during reproduction to socialize and communicate, or to defend a territory. In the marine environment, sight is only useful up to a few tens of meters, whereas sound can propagate over hundreds or even thousands of kilometers. Directive 2008/56/EC of the European Parliament and of the Council of June 17, 2008 called the Marine Strategy Framework Directive (MSFD) require the Member States of the European Union to take the necessary measures to reduce the impacts of maritime activities to achieve and maintain a good environmental status of the marine environment. The Ocean-Planner is a web-based platform that provides to regulators, managers of protected or sensitive areas, etc. with a decision support tool that enable to anticipate and quantify the effectiveness of management measures in terms of reduction or modification the distribution of underwater noise, in response to Descriptor 11 of the MSFD and to the Marine Spatial Planning Directive. Based on the operational sound modelling tool Quonops Online Service, Ocean-Planner allows the user via an intuitive geographical interface to define management measures at local (Marine Protected Area, Natura 2000 sites, Harbors, etc.) or global (Particularly Sensitive Sea Area) scales, seasonal (regulation over a period of time) or permanent, partial (focused to some maritime activities) or complete (all maritime activities), etc. Speed limit, exclusion area, traffic separation scheme (TSS), and vessel sound level limitation are among the measures supported be the tool. Ocean Planner help to decide on the most effective measure to apply to maintain or restore the biodiversity and the functioning of the ecosystems of the coastal seabed, maintain a good state of conservation of sensitive areas and maintain or restore the populations of marine species.

Keywords: underwater noise, marine biodiversity, marine spatial planning, mitigation measures, prediction

Procedia PDF Downloads 111

Authors: R. Kanmaniraja, R. Freshipali, J. Abdullah, K. Niranjan, K. Balasubramani, V. R. Sanal Kumar

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The present environmental issues have made aircraft jet noise reduction a crucial problem in aero-acoustics research. Acoustic studies reveal that addition of chevrons to the nozzle reduces the sound pressure level reasonably with acceptable reduction in performance. In this paper comprehensive numerical studies on acoustic characteristics of different types of chevron nozzles have been carried out with non-reacting flows for the shape optimization of chevrons in supersonic nozzles for aerospace applications. The numerical studies have been carried out using a validated steady 3D density based, k-ε turbulence model. In this paper chevron with sharp edge, flat edge, round edge and U-type edge are selected for the jet acoustic characterization of supersonic nozzles. We observed that compared to the base model a case with round-shaped chevron nozzle could reduce 4.13% acoustic level with 0.6% thrust loss. We concluded that the prudent selection of the chevron shape will enable an appreciable reduction of the aircraft jet noise without compromising its overall performance. It is evident from the present numerical simulations that k-ε model can predict reasonably well the acoustic level of chevron supersonic nozzles for its shape optimization.

Keywords: supersonic nozzle, Chevron, acoustic level, shape optimization of Chevron nozzles, jet noise suppression

Procedia PDF Downloads 500

Authors: Jason Blair, Adeboye Adebayo, Mohamed Saad, Jeannette M. Byrne, Fabien A. Basset

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Running economy is a key physiological parameter of an individual’s running efficacy and a valid tool for predicting performance outcomes. Of the many factors known to influence running economy (RE), footwear certainly plays a role owing to its characteristics that vary substantially from model to model. Although minimalist footwear is believed to enhance RE and thereby endurance performance, conclusive research reports are scarce. Indeed, debates remain as to which footwear characteristics most alter RE. The purposes of this study were, therefore, two-fold: (a) to determine whether wearing minimalist shoes results in better RE compared to shod and to identify relationships with kinematic and muscle activation patterns; (b) to determine whether changes in RE with minimalist shoes are still evident following a fatiguing bout of exercise. Well-trained male distance runners (n=10; 29.0 ± 7.5 yrs; 71.0 ± 4.8 kg; 176.3 ± 6.5 cm) partook first in a maximal O₂ uptake determination test (VO₂ₘₐₓ = 61.6 ± 7.3 ml min⁻¹ kg⁻¹) 7 days prior to the experimental sessions. Second, in a fully randomized fashion, an RE test consisting of three 8-min treadmill runs in shod and minimalist footwear were performed prior to and following exercise induced fatigue (EIF). The minimalist and shod conditions were tested with a minimum of 7-day wash-out period between conditions. The RE bouts, interspaced by 2-min rest periods, were run at 2.79, 3.33, and 3.89 m s⁻¹ with a 1% grade. EIF consisted of 7 times 1000 m at 94-97% VO₂ₘₐₓ interspaced with 3-min recovery. Cardiorespiratory, electromyography (EMG), kinematics, rate of perceived exertion (RPE) and blood lactate were measured throughout the experimental sessions. A significant main speed effect on RE (p=0.001) and stride frequency (SF) (p=0.001) was observed. The pairwise comparisons showed that running at 2.79 m s⁻¹ was less economic compared to 3.33, and 3.89 m s⁻¹ (3.56 ± 0.38, 3.41 ± 0.45, 3.40 ± 0.45 ml O₂ kg⁻¹ km⁻¹; respectively) and that SF increased as a function of speed (79 ± 5, 82 ± 5, 84 ± 5 strides min⁻¹). Further, EMG analyses revealed that root mean square EMG significantly increased as a function of speed for all muscles (Biceps femoris, Gluteus maximus, Gastrocnemius, Tibialis anterior, Vastus lateralis). During EIF, the statistical analysis revealed a significant main effect of time on lactate production (from 2.7 ± 5.7 to 11.2 ± 6.2 mmol L⁻¹), RPE scores (from 7.6 ± 4.0 to 18.4 ± 2.7) and peak HR (from 171 ± 30 to 181 ± 20 bpm), expect for the recovery period. Surprisingly, a significant main footwear effect was observed on running speed during intervals (p=0.041). Participants ran faster with minimalist shoes compared to shod (3:24 ± 0:44 min [95%CI: 3:14-3:34] vs. 3:30 ± 0:47 min [95%CI: 3:19-3:41]). Although EIF altered lactate production and RPE scores, no other effect was noticeable on RE, EMG, and SF pre- and post-EIF, except for the expected speed effect. The significant footwear effect on running speed during EIF was unforeseen but could be due to shoe mass and/or heel-toe-drop differences. We also cannot discard the effect of speed on foot-strike pattern and therefore, running performance.

Keywords: exercise-induced fatigue, interval training, minimalist footwear, running economy

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Authors: Sue S. Feldman

Abstract:

As clinical and nursing informatics mature, an area that has gotten a lot of attention is the value capstone projects. Capstones are meant to address authentic and complex domain-specific problems. While capstone projects have not always been essential in graduate clinical and nursing informatics education, employers are wanting to see evidence of the prospective employee's knowledge and skills as an indication of employability. Capstones can be organized in many ways: a single course over a single semester, multiple courses over multiple semesters, as a targeted demonstration of skills, as a synthesis of prior knowledge and skills, mentored by one single person or mentored by various people, submitted as an assignment or presented in front of a panel. Because of the potential for capstones to enhance the educational experience, and as a mechanism for application of knowledge and demonstration of skills, a rigorous capstone can accelerate a graduate's potential in the workforce. In 2016, the capstone at the University of Alabama at Birmingham (UAB) could feel the external forces of a maturing Clinical and Nursing Informatics discipline. While the program had a capstone course for many years, it was lacking the depth of knowledge and demonstration of skills being asked for by those hiring in a maturing Informatics field. Since the program is online, all capstones were always in the online environment. While this modality did not change, other contributors to instruction modality changed. Pre-2016, the instruction modality was self-guided. Students checked in with a single instructor, and that instructor monitored progress across all capstones toward a PowerPoint and written paper deliverable. At the time, the enrollment was few, and the maturity had not yet pushed hard enough. By 2017, doubling enrollment and the increased demand of a more rigorously trained workforce led to restructuring the capstone so that graduates would have and retain the skills learned in the capstone process. There were three major changes: the capstone was broken up into a 3-course sequence (meaning it lasted about 10 months instead of 14 weeks), there were many chunks of deliverables, and each faculty had a cadre of about 5 students to advise through the capstone process. Literature suggests that the chunking, breaking up complex projects (i.e., the capstone in one summer) into smaller, more manageable chunks (i.e., chunks of the capstone across 3 semesters), can increase and sustain learning while allowing for increased rigor. By doing this, the teaching responsibility was shared across faculty with each semester course being taught by a different faculty member. This change facilitated delving much deeper in instruction and produced a significantly more rigorous final deliverable. Having students advised across the faculty seemed like the right thing to do. It not only shared the load, but also shared the success of students. Furthermore, it meant that students could be placed with an academic advisor who had expertise in their capstone area, further increasing the rigor of the entire capstone process and project and increasing student knowledge and skills.

Keywords: capstones, clinical informatics, health informatics, informatics

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Authors: Elisa Y. M. Ang, Teng Yong Ng, Jingjie Yeo, Rongming Lin, Zishun Liu, K. R. Geethalakshmi

Abstract:

By stacking carbon nanotubes (CNT) one on top of another, single layer CNT arrays can perform water-salt separation with ultra-high permeability and selectivity. Such outer-wall CNT slit membrane is named as the transverse flow CNT membrane. By adjusting the slit size between neighboring CNTs, the membrane can be configured to sieve out different solutes, right down to the separation of monovalent salt ions from water. Molecular dynamics (MD) simulation results show that the permeability of transverse flow CNT membrane is more than two times that of conventional axial-flow CNT membranes, and orders of magnitude higher than current reverse osmosis membrane. In addition, by carrying out MD simulations with different CNT size, it was observed that the variance in desalination performance with CNT size is small. This insensitivity of the transverse flow CNT membrane’s performance to CNT size is a distinct advantage over axial flow CNT membrane designs. Not only does the membrane operate well under constant pressure desalination operation, but MD simulations further indicate that oscillatory operation can further enhance the membrane’s desalination performance, making it suitable for operation such as electrodialysis reversal. While there are still challenges that need to be overcome, particularly on the physical fabrication of such membrane, it is hope that this versatile membrane design can bring the idea of using low dimensional structures for desalination closer to reality.

Keywords: carbon nanotubes, membrane desalination, transverse flow carbon nanotube membrane, molecular dynamics

Procedia PDF Downloads 182

Authors: Salim Al Jadidi, Shian Gao, Shivananda Moolya

Abstract:

Computational Fluid Dynamic (CFD) technique coupled with Sub-Grid-Scale (SGS) model is used to study the flow behavior of heavy oil-water-air flow in a horizontal pipe by adapting ANSYS Fluent CFD software. The technique suitable for the transport of water-lubricated heavy viscous oil in a horizontal pipe is the Core Annular flow (CAF) technique. The present study focuses on the numerical study of CAF adapting Large Eddy Simulations (LES). The basic objective of the present study is to gain a basic knowledge of the flow behavior of heavy oil using turbulent CAF through a conventional horizontal pipe. This work also focuses on the success and applicability of LES. The simulation of heavy oil-water-air three-phase flow and two-phase flow of heavy oil–water in a conventional horizontal pipe is performed using ANSYS Fluent 16.2 software. The influence of three-phase heavy oil-water air flow in a selected pipe is affected by gravity. It is also observed from the result that the air phase and the variation in the temperature impact the behavior of the annular stream and pressure drop. Some results obtained during the study are validated with the results gained from part of the literature experiments and simulations, and the results show reasonably good agreement between the studies.

Keywords: computational fluid dynamics, gravity, heavy viscous oil, three-phase flow

Procedia PDF Downloads 65

Authors: H. Booke, R. Nordmeier

Abstract:

Sudden cardiac arrest is sometimes eye-witnessed by kids. Mostly, their (grand-)parents are affected by sudden cardiac arrest, putting these kids under enormous psychological pressure: Although they are more than desperate to help, they feel insecure and helpless and are afraid of causing harm rather than realizing their chance to help. Even years later, they may blame themselves for not having helped their beloved ones. However, the absolute majority of school children - at least in Germany - is not educated to provide first aid. Teaching young kids (5th grade) in basic life support thus may help to save lives while washing away the kids' fear from causing harm during cardio-pulmonary resuscitation. A teaching of circulatory and respiratory (patho-)physiology, followed by hands-on training of basic life support for every single child, was offered to each school in our district. The teaching was performed by anesthesiologists, and the program was called 'kids can save lives'. However, before enrollment in this program, the entire class must have had lessons in biology with a special focus on heart and circulation as well as lung and gas exchange. More than 1.000 kids were taught and trained in basic life support, giving them the knowledge and skills to provide basic life support. This may help to reduce the rate of failure to provide first aid. Therefore, educating young kids in basic life support may not only help to save lives, but it also may help to prevent any feelings of guilt because of not having helped in cases of eye-witnessed sudden cardiac arrest.

Keywords: teaching, children, basic life support, cardiac arrest, CPR

Procedia PDF Downloads 122

Authors: S. M. A. Al Qawabah, A. I. O. Zaid

Abstract:

Al-4%Cu alloys are now widely used in many engineering applications especially in robotic, aerospace and vibration control area. The main problem arises from the weakness of their mechanical characteristics. Therefore, this study is directed towards enhancing the mechanical properties through severe plastic deformation. In this work, the hot direct extrusion process was chosen to provide the required hot work for this purpose. A direct extrusion die was designed and manufactured to be used in this investigation. The general microstructure, microhardness, surface roughness, and compression tests were performed on specimens from the produced Al-4%Cu alloy both in the as cast and after extrusion conditions. It was found that a pronounced enhancement in the mechanical characteristics of the produced Al-4%Cu after extrusion was achieved. The microhardness increased by 89.3%, the flow stress was decreased by 10% at 0.2 strain and finally the surface roughness was reduced by 81.6%.

Keywords: aluminum, copper, surface roughness, hot extrusion

Procedia PDF Downloads 561

Authors: Varun Mittal, Shishir Sinha

Abstract:

The present experimental study focused on the hardness behavior of bagasse fiber-epoxy composites. The relationship between bagasse fiber content and effect of chemical treatment on bagasse fiber as a function of Brinell hardness of bagasse fiber epoxy was investigated. Bagasse fiber was treated with sodium hydroxide followed by acrylic acid before they were reinforced with epoxy resin. Compared hardness properties with the untreated bagasse filled epoxy composites. It was observed that Brinell hardness increased up to 15 wt% fiber content and further decreases, however, chemical treatment also improved the hardness properties of composites.

Keywords: bagasse fiber, composite, hardness, sodium hydroxide

Procedia PDF Downloads 273