Search results for: lower abdominal surgery
3678 Modification of Titanium Surfaces with Micro/Nanospheres for Local Antibiotic Release
Authors: Burcu Doymus, Fatma N. Kok, Sakip Onder
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Titanium and titanium-based materials are commonly used to replace or regenerate the injured or lost tissues because of accidents or illnesses. Hospital infections and strong bond formation at the implant-tissue interface are directly affecting the success of the implantation as weak bonding with the native tissue and hospital infections lead to revision surgery. The purpose of the presented study is to modify the surface of the titanium substrates with nano/microspheres for local drug delivery and to prevent hospital infections. Firstly, titanium surfaces were silanized with APTES (3-Triethoxysilylpropylamine) following the negatively charged oxide layer formation. Then characterization studies using Scanning Electron Microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were done on the modified surfaces. Secondly, microspheres/nanospheres were prepared with chitosan that is a natural polymer and having valuable properties such as non-toxicity, high biocompatibility, low allergen city and biodegradability for biomedical applications. Antibiotic (ciprofloxacin) loaded micro/nanospheres have been fabricated using emulsion cross-linking method and have been immobilized onto the titanium surfaces with different immobilization techniques such as covalent bond and entrapment. Optimization studies on size and drug loading capacities of micro/nanospheres were conducted before the immobilization process. Light microscopy and SEM were used to visualize and measure the size of the produced micro/nanospheres. Loaded and released drug amounts were determined by using UV- spectrophotometer at 278 nm. Finally, SEM analysis and drug release studies on the micro/nanospheres coated Ti surfaces were done. As a conclusion, it was shown that micro/nanospheres were immobilized onto the surfaces successfully and drug release from these surfaces was in a controlled manner. Moreover, the density of the micro/nanospheres after the drug release studies was higher on the surfaces where the entrapment technique was used for immobilization. Acknowledgement: This work is financially supported by The Scientific and Technological Research Council Of Turkey (Project # 217M220)Keywords: chitosan, controlled drug release, nanosphere, nosocomial infections, titanium
Procedia PDF Downloads 1223677 Imports of Intermediate Inputs: A Study of the Main Research Streams
Authors: Marta Fernández Olmos, Jorge Fleta, Talia Gómez
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This article shares the results of a temporal analysis of the literature on imports of intermediate inputs based on review techniques. The aim of this paper is to identify the main lines of research, their trends, topics, and the research agenda. The internationalization field has attracted considerable scholars and practitioners’ attention in recent years and has grown, rapidly, resulting in a large body of knowledge scattered in different areas of specialization. However, there are no studies that are entirely restricted to imports, intermediate inputs and innovation performance. The performance analysis provided an updated overview of the evolution of the importing literature from 1970 to 2022 and quantitatively identified the most productive and influential journals, articles, authors, and countries. The results show that the current topics are mainly based on modes of importing, innovation performance of importing intermediate imports and collaborations. Future lines of research are identified from topics with lower co-occurrence, such as artificial intelligence, entrepreneurship, and alternative business models such as multinational enterprises (MNEs) versus non-MNEs.Keywords: imports, intermediate inputs, innovation performance, review
Procedia PDF Downloads 633676 Rising of Single and Double Bubbles during Boiling and Effect of Electric Field in This Process
Authors: Masoud Gholam Ale Mohammad, Mojtaba Hafezi Birgani
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An experimental study of saturated pool boiling on a single artificial nucleation site without and with the application of an electric field on the boiling surface has been conducted. N-pentane is boiling on a copper surface and is recorded with a high speed camera providing high quality pictures and movies. The accuracy of the visualization allowed establishing an experimental bubble growth law from a large number of experiments. This law shows that the evaporation rate is decreasing during the bubble growth, and underlines the importance of liquid motion induced by the preceding bubble. Bubble rise is therefore studied: once detached, bubbles accelerate vertically until reaching a maximum velocity in good agreement with a correlation from literature. The bubbles then turn to another direction. The effect of applying an electric field on the boiling surface in finally studied. In addition to changes in the bubble shape, changes are also shown in the liquid plume and the convective structures above the surface. Lower maximum rising velocities were measured in the presence of electric fields, especially with a negative polarity.Keywords: single and double bubbles, electric field, boiling, rising
Procedia PDF Downloads 2223675 Numerical Study of Effects of Air Dam on the Flow Field and Pressure Distribution of a Passenger Car
Authors: Min Ye Koo, Ji Ho Ahn, Byung Il You, Gyo Woo Lee
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Everything that is attached to the outside of the vehicle to improve the driving performance of the vehicle by changing the flow characteristics of the surrounding air or to pursue the external personality is called a tuning part. Typical tuning components include front or rear air dam, also known as spoilers, splitter, and side air dam. Particularly, the front air dam prevents the airflow flowing into the lower portion of the vehicle and increases the amount of air flow to the side and front of the vehicle body, thereby reducing lift force generation that lifts the vehicle body, and thus, improving the steering and driving performance of the vehicle. The purpose of this study was to investigate the role of anterior air dam in the flow around a sedan passenger car using computational fluid dynamics. The effects of flow velocity, trajectory of fluid particles on static pressure distribution and pressure distribution on body surface were investigated by varying flow velocity and size of air dam. As a result, it has been confirmed that the front air dam improves the flow characteristics, thereby reducing the generation of lift force of the vehicle, so it helps in steering and driving characteristics.Keywords: numerical study, air dam, flow field, pressure distribution
Procedia PDF Downloads 1993674 Potential Enhancement of Arsenic Removal Filter Commonly Used in South Asia: A Review
Authors: Sarthak Karki, Haribansha Timalsina
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Kanchan Arsenic Filter is an economical low cost and termed the most efficient arsenic removal filter system in South Asian countries such as Nepal. But when the effluent quality was evaluated, it was seen to possess a lower removal rate of arsenite species. In addition to that, greater pathogenic growth and loss in overall efficacy with time due to precipitation of iron sulphates were the further complications. This brings the health issue on the front line as millions of people rely on groundwater sources for general water necessities. With this paper, we analyzed the mechanisms and changes in the efficiency of the extant filter system when integrated with activated laterite and hair column beds, plus an additional charcoal layer for inhibiting pathogen colonies. Hair column have rich keratin protein that binds with arsenic species, and similarly, raw laterite has huge deposits of iron and aluminum, all of these factors helping to remove heavy metal contaminants from water sources. Further study on the commercialized mass production of the new proposed filter and versatility analysis is required.Keywords: laterite, charcoal, arsenic removal, hair column
Procedia PDF Downloads 823673 Study of the Transport of Multivalent Metal Cations Through Cation-Exchange Membranes by Electrochemical Impedance Spectroscopy
Authors: V. Pérez-Herranz, M. Pinel, E. M. Ortega, M. García-Gabaldón
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In the present work, Electrochemical Impedance Spectrocopy (EIS) is applied to study the transport of different metal cations through a cation-exchange membrane. This technique enables the identification of the ionic-transport characteristics and to distinguish between different transport mechanisms occurring at different current density ranges. The impedance spectra are dependent on the applied dc current density, on the type of cation and on the concentration. When the applied dc current density increases, the diameter of the impedance spectra loops increases because all the components of membrane system resistance increase. The diameter of the impedance plots decreases in the order of Na(I), Ni(II) and Cr(III) due to the increased interactions between the negatively charged sulfonic groups of the membrane and the cations with greater charge. Nyquist plots are shifted towards lower values of the real impedance, and its diameter decreases with the increase of concentration due to the decrease of the solution resistance.Keywords: ion-exchange membranes, Electrochemical Impedance Spectrocopy, multivalent metal cations, membrane system
Procedia PDF Downloads 5233672 Computer-Based Model for Design Selection of Lightning Arrester for 132/33kV Substation
Authors: Uma U. Uma, Uzoechi Laz
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Protection of equipment insulation against lightning over voltages and selection of lightning arrester that will discharge at lower voltage level than the voltage required to breakdown the electrical equipment insulation is examined. The objectives of this paper are to design a computer based model using standard equations for the selection of appropriate lightning arrester with the lowest rated surge arrester that will provide adequate protection of equipment insulation and equally have a satisfactory service life when connected to a specified line voltage in power system network. The effectiveness and non-effectiveness of the earthing system of substation determine arrester properties. MATLAB program with GUI (graphic user interphase) its subprogram is used in the development of the model for the determination of required parameters like voltage rating, impulse spark over voltage, power frequency spark over voltage, discharge current, current rating and protection level of lightning arrester of a specified voltage level of a particular line.Keywords: lightning arrester, GUIs, MatLab program, computer based model
Procedia PDF Downloads 4103671 Rheological Characteristics of Ice Slurries Based on Propylene- and Ethylene-Glycol at High Ice Fractions
Authors: Senda Trabelsi, Sébastien Poncet, Michel Poirier
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Ice slurries are considered as a promising phase-changing secondary fluids for air-conditioning, packaging or cooling industrial processes. An experimental study has been here carried out to measure the rheological characteristics of ice slurries. Ice slurries consist in a solid phase (flake ice crystals) and a liquid phase. The later is composed of a mixture of liquid water and an additive being here either (1) Propylene-Glycol (PG) or (2) Ethylene-Glycol (EG) used to lower the freezing point of water. Concentrations of 5%, 14% and 24% of both additives are investigated with ice mass fractions ranging from 5% to 85%. The rheological measurements are carried out using a Discovery HR-2 vane-concentric cylinder with four full-length blades. The experimental results show that the behavior of ice slurries is generally non-Newtonian with shear-thinning or shear-thickening behaviors depending on the experimental conditions. In order to determine the consistency and the flow index, the Herschel-Bulkley model is used to describe the behavior of ice slurries. The present results are finally validated against an experimental database found in the literature and the predictions of an Artificial Neural Network model.Keywords: ice slurry, propylene-glycol, ethylene-glycol, rheology
Procedia PDF Downloads 2543670 Stress Recovery and Durability Prediction of a Vehicular Structure with Random Road Dynamic Simulation
Authors: Jia-Shiun Chen, Quoc-Viet Huynh
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This work develops a flexible-body dynamic model of an all-terrain vehicle (ATV), capable of recovering dynamic stresses while the ATV travels on random bumpy roads. The fatigue life of components is forecasted as well. While considering the interaction between dynamic forces and structure deformation, the proposed model achieves a highly accurate structure stress prediction and fatigue life prediction. During the simulation, stress time history of the ATV structure is retrieved for life prediction. Finally, the hot sports of the ATV frame are located, and the frame life for combined road conditions is forecasted, i.e. 25833.6 hr. If the usage of vehicle is eight hours daily, the total vehicle frame life is 8.847 years. Moreover, the reaction force and deformation due to the dynamic motion can be described more accurately by using flexible body dynamics than by using rigid-body dynamics. Based on recommendations made in the product design stage before mass production, the proposed model can significantly lower development and testing costs.Keywords: flexible-body dynamics, veicle, dynamics, fatigue, durability
Procedia PDF Downloads 3853669 Influence of Surfactant on Supercooling Degree of Aqueous Titania Nanofluids in Energy Storage Systems
Authors: Hoda Aslani, Mohammad Moghiman, Mohammad Aslani
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Considering the demand to reduce global warming potential and importance of solidification in various applications, there is an increasing interest in energy storage systems to find the efficient phase change materials. Therefore, this paper presents an experimental study and comparison on the potential of titania nanofluids with and without surfactant for cooling energy storage systems. A designed cooling generation device based on compression refrigeration cycle is used to explore nanofluids solidification characteristics. In this work, titania nanoparticles of 0.01, 0.02 and 0.04 wt.% are dispersed in deionized water as base fluid. Measurement of phase change parameters of nanofluids illustrates that the addition of polyvinylpyrrolidone (PVP) as surfactant to titania nanofluids advances the onset nucleation time and leads to lower solidification time. Also, the experimental results show that only adding 0.02 wt.% titania nanoparticles, especially in the case of nanofluids with a surfactant, can evidently reduce the supercooling degree by nearly 70%. Hence, it is concluded that there is a great energy saving potential in the energy storage systems using titania nanofluid with PVP.Keywords: cooling energy storage, nanofluid, PVP, solidification, titania
Procedia PDF Downloads 1863668 Shell Lime: An Eco-Friendly and Cost-Efficient Alternative for Agricultural Lime
Authors: Hene L. Hapinat, Mae D. Dumapig
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This study aimed to determine the lime potential of 3 mollusks, namely: Crassostrea iredalei (Oyster shell), Turritella terebra (Turret shell), and Anodontia edentula (Mangrove clam shell) as alternative for commercially produced agricultural lime. The hydrogen ion concentration (pH) and the lime concentration using Calcium Carbonate Equivalent (CCE) of each shellfish species were measured and tested for the enhancement of an acidic soil. The experiment was laid out in a Completely Randomized Design (CRD) with 4 treatments replicated 3 times. The treatments were as follows: Treatment A- 100 g agricultural lime; B- 100 g oyster shell lime; C- 100 g turret shell lime; and D- 100 g mangrove clam shell lime. Each treatment was combined to the acidic soil sample. The results were statistically analyzed using One-way Analysis of Variance (ANOVA) and Least Square Difference (LSD) at 0.01 and 0.05 levels of significance. Results revealed that lime produced from the 3 selected mollusks can be a potential source of alternative and/or supplement materials for agricultural lime in dealing with soil acidity, entailing lower cost of farm production.Keywords: shell lime, pH, calcium carbonate concentrations, mollusks, agricultural lime, lime potential concentration, acidic soil
Procedia PDF Downloads 3023667 Global Gender Differences in Job Satisfaction in the Hospitality Industry
Authors: Jonathan Hinton Westover, Maureen S. Andrade, Doug Miller
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Research has been inconclusive in determining if men or women experience more job satisfaction. A global comparison examining extrinsic and intrinsic factors, work relations, and work-life balance determinants found few differences; however, work relations and work-life balance factors were more significant for male than female workers across occupations. The current study uses International Social Survey Program data representing 37 countries to explore gender differences in job satisfaction in the hospitality industry. Findings demonstrate that mean job satisfaction scores for females are lower across hospitality occupations except for hotel receptionists, housekeeping supervisors, and hotel cleaners. Regression results revealed additional differences such as the significance of co-worker relations, the negative impact of being discriminated against and harassed at work, working weekends, marital status, and supervisory status for women with autonomy, work stress, education, and employment relationship being more salient for men. Interesting work, work being useful to society, job security, pay, relations with management, and work interfering with family were significant for both males and females.Keywords: job satisfaction, gender, hospitality, global comparisons
Procedia PDF Downloads 1303666 Modeling, Analysis and Control of a Smart Composite Structure
Authors: Nader H. Ghareeb, Mohamed S. Gaith, Sayed M. Soleimani
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In modern engineering, weight optimization has a priority during the design of structures. However, optimizing the weight can result in lower stiffness and less internal damping, causing the structure to become excessively prone to vibration. To overcome this problem, active or smart materials are implemented. The coupled electromechanical properties of smart materials, used in the form of piezoelectric ceramics in this work, make these materials well-suited for being implemented as distributed sensors and actuators to control the structural response. The smart structure proposed in this paper is composed of a cantilevered steel beam, an adhesive or bonding layer, and a piezoelectric actuator. The static deflection of the structure is derived as function of the piezoelectric voltage, and the outcome is compared to theoretical and experimental results from literature. The relation between the voltage and the piezoelectric moment at both ends of the actuator is also investigated and a reduced finite element model of the smart structure is created and verified. Finally, a linear controller is implemented and its ability to attenuate the vibration due to the first natural frequency is demonstrated.Keywords: active linear control, lyapunov stability theorem, piezoelectricity, smart structure, static deflection
Procedia PDF Downloads 3823665 Establishing Reference Intervals for Routine Coagulation Tests
Authors: Santina Sahibon, Sivasooriar Sivaneson, Martin Giddy, Nelson Nheu, Siti Sazeelah, Choo Kok Ming, Thuhairah Abdul Rahman, Fatmawati Binti Kamal
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Introduction: Establishing population-based reference intervals (RI) are essential when evaluating laboratory test results and for method verification. Our laboratory initiated an exercise to establish RI for routine coagulation profile as part of the method verification procedure and to determine any differences in RI between three analyzers planned to be used in the laboratory. Methodology: 145 blood samples were collected and analysed for activated partial thromboplastin time (aPTT), prothrombin time (PT), international normalized ratio (INR), and fibrinogen] using three coagulation analysers which were CA104, CA660, and CS-2500 (Sysmex, USA). RI was established at 2.5th and 97.5th percentiles. Results: The RI for aPTT between C104, C660 and CS-2500 are (RI: 20.5-30.2 sec), (RI: 21.5-29.2 sec) and (RI: 22.7-30.3 sec) respectively. The RI for PT were (RI: 7.5-10.3 sec), (RI: 9.2- 11.1 sec) and (RI: 9.8-11.9 sec) for C104, CA660 and CS-2500 respectively. INR had an RI of (RI: 0.87- 1.16), (RI: 0.89-1.10) and (0.90-1.11) respectively on CA104, C660 and CS-2500. Fibrinogen RI was (RI: 2.04-4.62 g/L) and (2.05-4.76 g/L) on the CA660 and CS-2500, respectively. Conclusion: The RI was similar across the analytical platforms for aPTT, INR, and fibrinogen. However, CA104 showed lower RI compared to the other two analysers for PT. This highlights the potential variability in results between instruments that need to be addressed when verifying RI.Keywords: coagulation, reference interval, APTT, PT, INR, fibrinogen
Procedia PDF Downloads 1753664 Prediction of Extreme Precipitation in East Asia Using Complex Network
Authors: Feng Guolin, Gong Zhiqiang
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In order to study the spatial structure and dynamical mechanism of extreme precipitation in East Asia, a corresponding climate network is constructed by employing the method of event synchronization. It is found that the area of East Asian summer extreme precipitation can be separated into two regions: one with high area weighted connectivity receiving heavy precipitation mostly during the active phase of the East Asian Summer Monsoon (EASM), and another one with low area weighted connectivity receiving heavy precipitation during both the active and the retreat phase of the EASM. Besides,a way for the prediction of extreme precipitation is also developed by constructing a directed climate networks. The simulation accuracy in East Asia is 58% with a 0-day lead, and the prediction accuracy is 21% and average 12% with a 1-day and an n-day (2≤n≤10) lead, respectively. Compare to the normal EASM year, the prediction accuracy is lower in a weak year and higher in a strong year, which is relevant to the differences in correlations and extreme precipitation rates in different EASM situations. Recognizing and identifying these effects is good for understanding and predicting extreme precipitation in East Asia.Keywords: synchronization, climate network, prediction, rainfall
Procedia PDF Downloads 4353663 A Digital Pulse-Width Modulation Controller for High-Temperature DC-DC Power Conversion Application
Authors: Jingjing Lan, Jun Yu, Muthukumaraswamy Annamalai Arasu
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This paper presents a digital non-linear pulse-width modulation (PWM) controller in a high-voltage (HV) buck-boost DC-DC converter for the piezoelectric transducer of the down-hole acoustic telemetry system. The proposed design controls the generation of output signal with voltage higher than the supply voltage and is targeted to work under high temperature. To minimize the power consumption and silicon area, a simple and efficient design scheme is employed to develop the PWM controller. The proposed PWM controller consists of serial to parallel (S2P) converter, data assign block, a mode and duty cycle controller (MDC), linearly PWM (LPWM) and noise shaper, pulse generator and clock generator. To improve the reliability of circuit operation at higher temperature, this design is fabricated with the 1.0-μm silicon-on-insulator (SOI) CMOS process. The implementation results validated that the proposed design has the advantages of smaller size, lower power consumption and robust thermal stability.Keywords: DC-DC power conversion, digital control, high temperatures, pulse-width modulation
Procedia PDF Downloads 3903662 Parental Expectations and Student Performance in Secondary School Mathematics Education
Authors: Daya Weerasinghe
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Parental expectations often differ to that of their children and the influence and involvement of parents, at home, may affect the student performance in the classroom. This paper presents results from a survey of Asian and European background secondary school mathematics students (N=128) in Melbourne, Australia. Student responses to survey questions were analysed using confirmatory factor analysis, followed by t-tests and ANOVA. The aim of the analysis was to identify similarities and differences in parental expectations in relation to ethnicity, gender, and the year level of the students. The notable findings from the analysis showed no significant difference (at 0.05 level) in parental expectations and student performance, in relation to ethnicity or gender. Conversely, there was a significant difference in both parental expectations and student performance between year 7 and year 12 students. Further, whilst there was a significant difference in parental expectations between year 7 and year 11 students, the students’ performances were not significantly different. The results suggest further research may be needed to understand the parental expectations and student performance between the lower and upper secondary school mathematics students.Keywords: ethnic background, gender, parental expectations, student performance, year level
Procedia PDF Downloads 3083661 Investigating the Antimicrobial Activity of Essential Oil Derived from Pistacia atlantica Gum against Extensively Drug-Resistant Gram-Negative Acinetobacter baumannii
Authors: Zhala Ahmad, Zainab Lazim, Haider Hamzah
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Bacterial resistance is a pressing global health issue, with multidrug-resistant (MDR), extensively drug-resistant (XDR), and pandrug-resistant (PDR) strains to pose a serious threat. In this context, researchers are investigating effective, safe, and affordable metabolites to combat these pathogens. This study focuses on gum essential oil (GEO) extracted from Pistacia atlantica and its activity and the mechanism of action against XDR Gram-negative Acinetobacter baumannii. GEO was extracted by hydrodistillation and analyzed using GC-MS. Eleven A. baumannii isolates were collected from the ward environment of Burn and Plastic Surgery Hospital in Al Sulaymaniyah City, Iraq. They were identified using the VITEK 2 system, 16S rRNA gene, and confirmed with the blaₒₓₐ₋₅₁ gene; A. baumannii ATCC 19606 was used as a reference strain. The isolates were identified as resistant to twelve different antibiotics spanning six distinct antibiotic classes while showing susceptibility to tetracycline and trimethoprim. Over 40 chemical constituents were detected in the gum's essential oils, with α-pinene being the most abundant. GEO was found to inhibit the growth of A. baumannii isolates; the minimum inhibitory concentration (MIC) of GEO was 2.5 µl/ml. GEO induced protein leakage, phosphate, and potassium ion efflux, distorted cell morphology, and cell death in the tested bacteria. GEO exhibited bacterial clearance and anti-adhesion activity using Band-Aids. This study's findings suggest that GEO could be used as a potential alternative treatment for infectious diseases caused by XRD pathogens, shedding further light on the importance of GEO in biomedical applications. Future studies must focus on generating clinically feasible sources of GEO for testing in small animal models before proceeding to human trials, ensuring safe and effective translation from the laboratory to the clinic.Keywords: antibiotic resistance, Acinetobacter baumannii, essential oils, Pistacia atlantica, alpha-pinene
Procedia PDF Downloads 653660 Being ‘Sciencey’: Scottish, South-Asian and Muslim Young People
Authors: Saima Salehjee, Mike Watts
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In our school-based world, we are commonly confronted by young people for whom the study of science is an unpalatable ‘other world’: they simply do not see themselves as science (sciencey) people. To be clear, we are not interested in all young people becoming career scientists – although some small modicum of that would be quite agreeable. We are, though, keen to form or transform (trans(form)) their appreciations of science and retain open minds on matters scientific to develop the feeling of being ‘sciencey’ with or without the aspiration of becoming scientists. Our discussion in this paper draws upon research undertaken in a co-education primary- and lower-secondary school in Scotland, and our arguments chart the trans(formations) of thirty under-representative and under-researched Scottish South-Asian Muslim students (aged 11-13) over a school term. We use science identity theory as the basis for our analysis: what it means to be ‘sciencey’ and whether (or not) structural forces have impacted their decision of being ‘sciencey’. This work offers new insights into how Scottish, South-Asian, and Muslim students perceive and engage with in and out of school science and highlight some science nudges aimed to support their development of being ‘sciencey’.Keywords: science identity, science nudges, transformative moments, south-Asian, Muslim, scottish, sciencey
Procedia PDF Downloads 1063659 Feasibility of a Biopolymer as Lightweight Aggregate in Perlite Concrete
Authors: Ali A. Sayadi, Thomas R. Neitzert, G. Charles Clifton
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Lightweight concrete is being used in the construction industry as a building material in its own right. Ultra-lightweight concrete can be applied as a filler and support material for the manufacturing of composite building materials. This paper is about the development of a stable and reproducible ultra-lightweight concrete with the inclusion of poly-lactic acid (PLA) beads and assessing the feasibility of PLA as a lightweight aggregate that will deliver advantages such as a more eco-friendly concrete and a non-petroleum polymer aggregate. In total, sixty-three samples were prepared and the effectiveness of mineral admixture, curing conditions, water-cement ratio, PLA ratio, EPS ratio and perlite ratio on compressive strength of perlite concrete are studied. The results show that PLA particles are sensitive to alkali environment of cement paste and considerably shrank and lost their strength. A higher compressive strength and a lower density was observed when expanded polystyrene (EPS) particles replaced PLA beads. In addition, a set of equations is proposed to estimate the water-cement ratio, cement content and compressive strength of perlite concrete.Keywords: perlite concrete, poly-lactic acid (pla), expanded polystyrene (eps), concrete
Procedia PDF Downloads 3063658 Microbial Corrosion on Oil and Gas Facilities: A Case Study of Oil and Gas Facilities in the Niger-Delta
Authors: Frederick Otite Ighovojah
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Corrosion in the oil and gas industries is one of the most common causes of failure. Such failure includes leaks in above-ground storage tanks (AGST). The involvement of microorganisms in the corrosion process in AGST systems is often ignored, and this outlines the need to investigate the effect of microbial corrosion in oil and gas facilities. This study's methodology comprised gathering generated water samples from a nearby AGST oil facility that was operating, which were then equally divided into two batch reactors, 1 and 2. Each batch reactor was filled with five prepared X60 coupons using sterilized forceps. To provide nutrients for the microorganisms in batch reactor 1 during the test period, 2g of NPK 15- 15-15 fertilizer was added on a weekly basis. To kill the microorganisms and significantly lower their concentration in the generated water, 5ml of dissolved ozone (a biocide) with a 0.5ppm concentration was added to batch reactor 2. The weight loss measurement (WLM) was used to evaluate for corrosion. Coupons were removed from each batch reactor, and weight loss was measured at every interval of 336 hrs for 2016 hrs. The overall results obtained indicated that coupons from the batch 1 reactor showed a higher corrosion rate and higher mass loss, and this was due to the metabolic production of an aggressive compound in the medium.Keywords: AGST, microbial corrosion, reactor, X60 steel
Procedia PDF Downloads 743657 Spectroscopic Study of Eu³⁺ Ions Doped Potassium Lead Alumino Borate Glasses for Photonic Device Application
Authors: Nisha Deopa, Allam Srinivasa Rao
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Quaternary potassium lead alumino borate (KPbAlB) glasses doped with different concentration of Eu³⁺ ions have been synthesized by melt quench technique and characterized by X-ray diffraction (XRD), Scanning electron microscope (SEM), Photoluminescence (PL), Time-resolved photoluminescence (TRPL) and CIE-chromaticity co-ordinates to study their luminescence behavior. A broad hump was observed in XRD spectrum confirms glassy nature of as-prepared glasses. By using Judd-Ofelt (J-O) theory, various radiative parameters for the prominent fluorescent levels of Eu³⁺ have been investigated. The intense emission peak was observed at 613 nm (⁵D₀→⁷F₂) under 393 nm excitation, matches well with the excitation of n-UV LED chips. The decay profiles observed for ⁵D₀ level were exponential for lower Eu³⁺ ion concentration while non-exponential for higher concentration, which may be due to efficient energy transfer between Eu³⁺-Eu³⁺ through cross relaxation and subsequent quenching observed. From the emission cross-sections, branching ratios, quantum efficiency and CIE coordinates, it was concluded that 7 mol % of Eu³⁺ ion concentration (glass B) is optimum in KPbAlB glasses for photonic device application.Keywords: energy transfer, glasses, J-O parameters, photoluminescence
Procedia PDF Downloads 1573656 Phenolic Compounds, Antiradical Activity, and Antioxidant Efficacy of Satureja hortensisl - Extracts in Vegetable Oil Protection
Authors: Abolfazl Kamkar
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Vegetable oils and fats are recognized as important components of our diet. They provide essential fatty acids, which are precursors of important hormones and control many physiological factors such as blood pressure, cholesterol level, and the reproductive system.Vegetable oils with higher contents of unsaturated fatty acids, especially polyunsaturated fatty acids (PUFAs) are more susceptible to oxidation.Protective effects of Sature jahortensis(SE) extracts in stabilizing soybean oil at different concentrations (200 and 400 ppm) were tested. Results showed that plant extracts could significantly (P< 0.05) lower the peroxide value and thiobarbituric acid value of oil during storage at 60 oC. The IC50 values for methanol and ethanol extracts were 31.5 ± 0.7 and 37.00 ± 0 µg/ml, respectively. In the β- carotene/linoleic acid system, methanol and ethanol extracts exhibited 87.5 ± 1.41% and 74.0 ±2.25 % inhibition against linoleic acid oxidation. The total phenolic and flavonoid contents of methanol and ethanol extracts were (101.58 ± 0. 26m g/ g) and (96.00 ± 0.027 mg/ g), (44.91 ± 0.14 m g/ g) and (14.30 ± 0.12 mg/ g) expressed in Gallic acid and Quercetin equivalents, respectively.These findings suggest that Satureja extracts may have potential application as natural antioxidants in the edible oil and food industry.Keywords: satureja hortensis, antioxidant activity, oxidative stability, vegetable oil, extract
Procedia PDF Downloads 3613655 Process Optimization of Mechanochemical Synthesis for the Production of 4,4 Bipyridine Based MOFS using Twin Screw Extrusion and Multivariate Analysis
Authors: Ahmed Metawea, Rodrigo Soto, Majeida Kharejesh, Gavin Walker, Ahmad B. Albadarin
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In this study, towards a green approach, we have investigated the effect of operating conditions of solvent assessed twin-screw extruder (TSE) for the production of 4, 4-bipyridine (1-dimensional coordinated polymer (1D)) based coordinated polymer using cobalt nitrate as a metal precursor with molar ratio 1:1. Different operating parameters such as solvent percentage, screw speed and feeding rate are considered. The resultant product is characterized using offline characterization methods, namely Powder X-ray diffraction (PXRD), Raman spectroscopy and scanning electron microscope (SEM) in order to investigate the product purity and surface morphology. A lower feeding rate increased the product’s quality as more resident time was provided for the reaction to take place. The most important influencing factor was the amount of liquid added. The addition of water helped in facilitating the reaction inside the TSE by increasing the surface area of the reaction for particlesKeywords: MOFS, multivariate analysis, process optimization, chemometric
Procedia PDF Downloads 1513654 The Effect of Soil Binder and Gypsum to the Changes of the Expansive Soil Shear Strength Parameters
Authors: Yulia Hastuti, Ratna Dewi, Muhammad Sandi
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Many methods of soil stabilization that can be done such as by mixing chemicals. In this research, stabilization by mixing the soil using two types of chemical admixture, those are gypsum with a variation of 5%, 10%, and 15% and Soil binder with a concentration of 20 gr / lot of water, 25 gr / lot of water, and 30 gr / lot of water aimed to determine the effect on the soil plasticity index values and comparing the value of shear strength parameters of the mixture with the original soil conditions using a Triaxial UU test. Based on research done shows that with increasing variations in the mix, then the value of plasticity index decreased, which was originally 42% (very high degree of swelling) becomes worth 11.24% (lower Swelling degree) when a mixture of gypsum 15% and 30 gr / Lt water soil binder. As for the value shear, strength parameters increased in all variations of mixture. Admixture with the highest shear strength parameter's value is at 15% the mixture of gypsum and 20 gr / litre of water of soil binder with the 14 day treatment period, which has enhanced the cohesion value of 559.01%, the friction angle by 1157.14%. And a shear strength value of 568.49%. It can be concluded that the admixture of gypsum and soil binder correctly, can increase the value of shear strength parameters significantly and decrease the value of plasticity index of the soil.Keywords: expansive soil, gypsum, soil binder, shear strength
Procedia PDF Downloads 4633653 Unravelling Domestic Electricity Demand by Domestic Renewable Energy Supply: A Case Study in Yogyakarta and Central Java, Indonesia
Authors: Diyono Harun
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Indonesia aims to reduce carbon emissions from energy generation by reaching 23% and 31% of the national energy supply from renewable energy sources (RES) in 2025 and 2030. The potential for RES in Indonesia is enormous, but not all province has the same potential for RES. Yogyakarta, one of the most travel-destinated provinces in Indonesia, has less potential than its neighbour, Central Java. Consequently, Yogyakarta must meet its electricity demand by importing electricity from Central Java if this province only wants to use electricity from RES. Thus, achieving the objective is balancing the electricity supply between an importer (Yogyakarta) and an exporter province (Central Java). This research aims to explore the RES potential and the current capacity of RES for electricity generation in both provinces. The results show that the present capacity of RES meets the annual domestic electricity demand in both provinces only with an extension of the RES potential. The renewable energy mixes in this research also can lower CO2 emissions compared to gas-fired power plants. This research eventually provides insights into exploring and using the domestic RES potentials between two areas with different RES capacities.Keywords: energy mix, renewable energy sources, domestic electricity, electricity generation
Procedia PDF Downloads 813652 Effect of 16 Weeks Walking with Different Dosages on Psychosocial Function Related Quality of Life among 60 to 75 Years Old Men
Authors: Mohammad Ehsani, Elham Karimi, Hashem Koozechian
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Aim: The purpose of current semi-experimental study was a survey on effect of 16 week walking on psychosocial function related quality of life among 60 to 75 years old men. Methodology: For this reason, short from of health – related quality of life questionnaire (SF – 36) and Geriatric Depression Scale (GDS) had been distributed to the subjects at 2 times of pre – test and posttest. Statistical sample of current study was 60 to 75 years old men who placed at Kahrizak house and assessed by considering physically and medical background. Also factors of entrance to the intervention like age range, have satisfaction and have intent to participating in walking program, lack of having diabetic, cardiovascular, Parkinsonism diseases and postural, neurological, musculoskeletal disorders, lack of having clinical background like visual disorders or disordering on equilibrium system, lack of motor limitation, foot print disorders, having surgery and mental health had been determined and assessed. Finally after primary studies, 80 persons selected and categorized accidentally to the 3 experimental group (1, 2, 3 sessions per week, 30 min walking with moderate intension at every sessions) and one control group (without physical activity in period of 16 weeks). Data analysed by employing ANOVA, Pearson coefficient and Scheffe Post – Hoc tests at the significance level of p < 0.05. Results: Results showed that psychosocial function of men with 60 to 75 years old increase by influence of 16 week walking and increase of exercise sessions lead to more effectiveness of walking. Also there was no significant difference between psychosocial function of subjects within 1 session and 3 sessions experimental groups (p > 0.05). Conclusion: On the basis of results, we can say that doing regular walking with efficient and standard dosage for elderly people, can increase their quality of life. Furthermore, designing and action operation regular walking program for elderly men on the basis of special, logical and systematic pattern under the supervision of aware coaches have been recommended on the basis of results.Keywords: walking, quality of life, psychosocial function, elders
Procedia PDF Downloads 5833651 Particle Size Characteristics of Aerosol Jets Produced by a Low Powered E-Cigarette
Authors: Mohammad Shajid Rahman, Tarik Kaya, Edgar Matida
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Electronic cigarettes, also known as e-cigarettes, may have become a tool to improve smoking cessation due to their ability to provide nicotine at a selected rate. Unlike traditional cigarettes, which produce toxic elements from tobacco combustion, e-cigarettes generate aerosols by heating a liquid solution (commonly a mixture of propylene glycol, vegetable glycerin, nicotine and some flavoring agents). However, caution still needs to be taken when using e-cigarettes due to the presence of addictive nicotine and some harmful substances produced from the heating process. Particle size distribution (PSD) and associated velocities generated by e-cigarettes have significant influence on aerosol deposition in different regions of human respiratory tracts. On another note, low actuation power is beneficial in aerosol generating devices since it exhibits a reduced emission of toxic chemicals. In case of e-cigarettes, lower heating powers can be considered as powers lower than 10 W compared to a wide range of powers (0.6 to 70.0 W) studied in literature. Due to the importance regarding inhalation risk reduction, deeper understanding of particle size characteristics of e-cigarettes demands thorough investigation. However, comprehensive study on PSD and velocities of e-cigarettes with a standard testing condition at relatively low heating powers is still lacking. The present study aims to measure particle number count and size distribution of undiluted aerosols of a latest fourth-generation e-cigarette at low powers, within 6.5 W using real-time particle counter (time-of-flight method). Also, temporal and spatial evolution of particle size and velocity distribution of aerosol jets are examined using phase Doppler anemometry (PDA) technique. To the authors’ best knowledge, application of PDA in e-cigarette aerosol measurement is rarely reported. In the present study, preliminary results about particle number count of undiluted aerosols measured by time-of-flight method depicted that an increase of heating power from 3.5 W to 6.5 W resulted in an enhanced asymmetricity in PSD, deviating from log-normal distribution. This can be considered as an artifact of rapid vaporization, condensation and coagulation processes on aerosols caused by higher heating power. A novel mathematical expression, combining exponential, Gaussian and polynomial (EGP) distributions, was proposed to describe asymmetric PSD successfully. The value of count median aerodynamic diameter and geometric standard deviation laid within a range of about 0.67 μm to 0.73 μm, and 1.32 to 1.43, respectively while the power varied from 3.5 W to 6.5 W. Laser Doppler velocimetry (LDV) and PDA measurement suggested a typical centerline streamwise mean velocity decay of aerosol jet along with a reduction of particle sizes. In the final submission, a thorough literature review, detailed description of experimental procedure and discussion of the results will be provided. Particle size and turbulent characteristics of aerosol jets will be further examined, analyzing arithmetic mean diameter, volumetric mean diameter, volume-based mean diameter, streamwise mean velocity and turbulence intensity. The present study has potential implications in PSD simulation and validation of aerosol dosimetry model, leading to improving related aerosol generating devices.Keywords: E-cigarette aerosol, laser doppler velocimetry, particle size distribution, particle velocity, phase Doppler anemometry
Procedia PDF Downloads 383650 Investigation of the Influencing Factors of Functional Communication Assessment for Adults with Aphasia
Authors: Yun-Ching Tu, Yu-Chun Chih
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People with aphasia (PWA) may have communicative difficulties in their daily lives, but research on functional communication in aphasia is still limited in Taiwan. The aim of the study was to investigate the impact of aphasia-related factors on functional communication assessment. This study adopted a convenience sampling method. Thirty aphasic participants participated in the study. During the test, the examiner would ask questions that are encountered in daily life and record the participant‘s responses. Some questions would provide pictures to simulate situations in daily life. The results showed that the non-fluent aphasia group performed significantly worse than the fluent aphasia group. In addition, patients with severe aphasia performed significantly lower scores than patients with moderate aphasia and mild aphasia. However, group differences in the chronic stage and acute stage were not significant. In sum, since communication in daily life is diverse and language is still needed in the communication process, patients with aphasia who have better language ability may have relatively better functional communication. In contrast, the more severely impaired the language ability of a patient with aphasia is, the more functional communication will be affected, resulting in poor communication performance in daily life.Keywords: adult, aphasia, assessment, functional communication
Procedia PDF Downloads 693649 Parallelizing the Hybrid Pseudo-Spectral Time Domain/Finite Difference Time Domain Algorithms for the Large-Scale Electromagnetic Simulations Using Massage Passing Interface Library
Authors: Donggun Lee, Q-Han Park
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Due to its coarse grid, the Pseudo-Spectral Time Domain (PSTD) method has advantages against the Finite Difference Time Domain (FDTD) method in terms of memory requirement and operation time. However, since the efficiency of parallelization is much lower than that of FDTD, PSTD is not a useful method for a large-scale electromagnetic simulation in a parallel platform. In this paper, we propose the parallelization technique of the hybrid PSTD-FDTD (HPF) method which simultaneously possesses the efficient parallelizability of FDTD and the quick speed and low memory requirement of PSTD. Parallelization cost of the HPF method is exactly the same as the parallel FDTD, but still, it occupies much less memory space and has faster operation speed than the parallel FDTD. Experiments in distributed memory systems have shown that the parallel HPF method saves up to 96% of the operation time and reduces 84% of the memory requirement. Also, by combining the OpenMP library to the MPI library, we further reduced the operation time of the parallel HPF method by 50%.Keywords: FDTD, hybrid, MPI, OpenMP, PSTD, parallelization
Procedia PDF Downloads 140