Search results for: Abir Abdulrahman
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 137

Search results for: Abir Abdulrahman

107 CuFeOx-Based Nano-Rose Electrocatalysts for Oxygen Evolution Reaction

Authors: Hamad Almohamadi, Nabeel H. Alharthi, Abdulrahman Aljabri

Abstract:

In this study, two-dimensional CuFeOx is deposited on nickel foam for the fabrication of electrocatalyst for oxygen evolution reaction (OER). The in-situ hydrothermal synthesis of CuFeOx in presence of aloe vera extract was found to yield unique nano-rose-like morphology which aided to improve the electrochemical surface area of the electrode. The phytochemical assisted synthesis of CuFeOx using 75% aloe vera extract resulted in improved OER electrocatalytic performance by attaining the overpotential of 310 mV for 50 mA cm−2 and 410 mV for 100 mA cm−2. The electrode also sustained robust stability throughout the 50 h of chronopotentiometry studies under alkaline electrolyte conditions, thus proving to be prospective electrode material for efficient OER in electrochemical water splitting.

Keywords: water splitting, phytochemicals, oxygen evaluation reaction, Tafel's slope, stability

Procedia PDF Downloads 89
106 A Resource Based View: Perspective on Acquired Human Resource towards Competitive Advantage

Authors: Monia Hassan Abdulrahman

Abstract:

Resource-based view is built on many theories in addition to diverse perspectives, we extend this view placing emphasis on human resources addressing the tools required to sustain competitive advantage. Highlighting on several theories and judgments, assumptions were established to clearly reach if resource possession alone suffices for the sustainability of competitive advantage, or necessary accommodation are required for better performance. New practices were indicated in terms of resources used in firms, these practices were implemented on the human resources in particular, and results were developed in compliance to the mentioned assumptions. Such results drew attention to the significance of practices that provide enhancement of human resources that have a core responsibility of maintaining resource-based view for an organization to lead the way to gaining competitive advantage.

Keywords: competitive advantage, resource based value, human resources, strategic management

Procedia PDF Downloads 368
105 Fluid Flow in Roughened Square Tube for Internal Blade Cooling

Authors: M. H. Alhajeri, Hamad M. Alhajeri, A. H. Alenezi, Abdulrahman Almutairi, Ayedh Alajmi

Abstract:

A computational investigation has been undertaken to study fluid flow through roughened tube with turbulators. Such flows are of particular interest in cooling internally high pressure turbine blades. Turbulators are fixed in each side of the passage (tube) to promote turbulence and enhance heat transfer. The tube had an aspect ratio of 1 and the position of the ribs closest to the bend are at 0.45d from the entrance and exit of the bend. The aim of this study is to examine the tube roughened by turbulator by studying some flow parameters upstream and downstream of the turbulator. It is cleared that the eddies sizes are decreased downstream in the first two turbulators and increased after the turbulators increases the turbulence in the tube and enhanced the heat transfer in the blade.

Keywords: fluid flow, turbulator, computation, blade

Procedia PDF Downloads 395
104 Ants of the Genus Trichomyrmex Mayr, 1865 (Hymenoptera: Formicidae) in the Arabian Peninsula, with Description of Two New Species

Authors: Mostafa R. Sharaf, Shehzad Salman, Hathal M. Al Dhafer, Shahid A. Akbar, Abdulrahman S. Aldawood

Abstract:

The ant genus Trichomyrmex Mayr is revised for the Arabian Peninsula based on the worker caste. Nine species are recognized and descriptions of two new species, T. almosayari sp. n. and T. shakeri sp. n. from Riyadh Province, the Kingdom of Saudi Arabia (KSA) are given. A key to species and diagnostic characters of the treated species are presented. New country records are presented, T. abyssinicus (Forel) for the KSA and T. destructor (Jerdon) and T. mayri (Forel) for the State of Qatar. New distribution records for T. destructor (Jerdon) and T. mayri (Forel) in the KSA are provided. Regional and world distributions, and distribution maps for the treated species are included. Ecological and biological data are given where known.

Keywords: ants, Trichomyrmex, Arabian Peninsula, T. almosayari, T. shakeri

Procedia PDF Downloads 315
103 Estimation of Enantioresolution of Multiple Stereogenic Drugs Using Mobilized and/or Immobilized Polysaccharide-Based HPLC Chiral Stationary Phases

Authors: Mohamed Hefnawy, Abdulrahman Al-Majed, Aymen Al-Suwailem

Abstract:

Enantioseparation of drugs with multiple stereogenic centers is challenging. This study objectives to evaluate the efficiency of different mobilized and/or immobilized polysaccharide-based chiral stationary phases to separate enantiomers of some drugs containing multiple stereogenic centers namely indenolol, nadolol, labetalol. The critical mobile phase variables (composition of organic solvents, acid/base ratios) were carefully studied to compare the retention time and elution order of all isomers. Different chromatographic parameters such as capacity factor (k), selectivity (α) and resolution (Rs) were calculated. Experimental conditions and the possible chiral recognition mechanisms have been discussed.

Keywords: HPLC, polysaccharide columns, enantio-resolution, indenolol, nadolol, labetalol

Procedia PDF Downloads 408
102 Analysis of Potential Flow around Two-Dimensional Body by Surface Panel Method and Vortex Lattice Method

Authors: M. Abir Hossain, M. Shahjada Tarafder

Abstract:

This paper deals with the analysis of potential flow past two-dimensional body by discretizing the body into panels where the Laplace equation was applied to each panel. The Laplace equation was solved at each panel by applying the boundary conditions. The boundary condition was applied at each panel to mathematically formulate the problem and then convert the problem into a computer-solvable problem. Kutta condition was applied at both the leading and trailing edges to see whether the condition is satisfied or not. Another approach that is applied for the analysis is Vortex Lattice Method (VLM). A vortex ring is considered at each control point. Using the Biot-Savart Law the strength at each control point is calculated and hence the pressure differentials are measured. For the comparison of the analytic result with the experimental result, different NACA section hydrofoil is used. The analytic result of NACA 0012 and NACA 0015 are compared with the experimental result of Abbott and Doenhoff and found significant conformity with the achieved result.

Keywords: Kutta condition, Law of Biot-Savart, pressure differentials, potential flow, vortex lattice method

Procedia PDF Downloads 165
101 A Review of Deformation and Settlement Monitoring on the Field: Types and Applications

Authors: Hassan Ali, Abdulrahman Hamid

Abstract:

This paper discusses using of instruments to monitor deformation and settlement. Specifically, it concentrates on field instruments such as inclinometer and plate load test and their applications in the field. Inclinometer has been used effectively to monitor lateral earth movements and settlement in landslide areas, embankments and foundations. They are also used to monitor the deflection of retaining walls and piles under load. This paper is reviewing types of inclinometer systems, comparison between systems, applications, field accuracy and correction. The paper also will present a case study of using inclinometer to monitor the creep movements within the ancient landslide on The Washington Park Station. Furthermore, the application of deformation and settlement instruments in Saudi Arabia will be discussed in this manuscript.

Keywords: inclinometer, plate load test, backfills, sand, deformation and settlement

Procedia PDF Downloads 245
100 Indoor Thermal Comfort in Educational Buildings in the State of Kuwait

Authors: Sana El-Azzeh, Farraj Al-Ajmi, Abdulrahman Al-Aqqad, Mohamed Salem

Abstract:

Thermal comfort is defined according to ANSI/ASHRAE Standard 55 as a condition of mind that expresses satisfaction with the thermal environment and is assessed by subjective evaluation. Sustaining this standard of thermal comfort for occupants of buildings or other enclosures is one of the important goals of HVAC design engineers. This paper presents a study of thermal comfort and adaptive behaviors of occupants who occupies two locations at the campus of the Australian College of Kuwait. A longitudinal survey and field measurement were conducted to measure thermal comfort, adaptive behaviors, and indoor environment qualities. The study revealed that female occupants in the selected locations felt warmer than males and needed more air velocity and lower temperature.

Keywords: indoor thermal comfort, educational facility, gender analysis, dry desert climate

Procedia PDF Downloads 126
99 Olefin and Paraffin Separation Using Simulations on Extractive Distillation

Authors: Muhammad Naeem, Abdulrahman A. Al-Rabiah

Abstract:

Technical mixture of C4 containing 1-butene and n-butane are very close to each other with respect to their boiling points i.e. -6.3°C for 1-butene and -1°C for n-butane. Extractive distillation process is used for the separation of 1-butene from the existing mixture of C4. The solvent is the essential of extractive distillation, and an appropriate solvent shows an important role in the process economy of extractive distillation. Aspen Plus has been applied for the separation of these hydrocarbons as a simulator; moreover NRTL activity coefficient model was used in the simulation. This model indicated that the material balances in this separation process were accurate for several solvent flow rates. Mixture of acetonitrile and water used as a solvent and 99 % pure 1-butene was separated. This simulation proposed the ratio of the feed to solvent as 1 : 7.9 and 15 plates for the solvent recovery column, previously feed to solvent ratio was more than this and the proposed plates were 30, which can economize the separation process.

Keywords: extractive distillation, 1-butene, Aspen Plus, ACN solvent

Procedia PDF Downloads 411
98 Numerical Simulation of Two-Dimensional Porous Cylinder Flow in In-Line Arrangement

Authors: Hamad Alhajeri, Abdulrahman Almutairi, A. H. Alenezi, M. H. Alhajeri, Ayedh Alajmi

Abstract:

The flow around three porous cylinders in inline arrangement is investigated in this paper computationally using the commercial code FLUENT. The arrangement generally operates with the dirty gases passing through the porous cylinders, the particulate material being deposited on the outside of the cylinders. However, in a combined cycle power plant, filtration is required to allow the hot exhaust gases to be fed to a turbine without causing any physical damage to the turbine blades. Three cylinder elements are placed in a two-dimensional rectangle duct with fixed face velocity and varying the velocity ratio between the approach and face velocity. Particle trajectories are obtained for a number of particle diameters and different inlet (approach) velocity to face filtration velocity ratios to investigate the behavior of particles around the cylinder.

Keywords: porous cylinders, CFD, fluid flow, filtration

Procedia PDF Downloads 454
97 Effect of Atmospheric Turbulence on Hybrid FSO/RF Link Availability under Qatar's Harsh Climate

Authors: Abir Touati, Syed Jawad Hussain, Farid Touati, Ammar Bouallegue

Abstract:

Although there has been a growing interest in the hybrid free-space optical link and radio frequency FSO/RF communication system, the current literature is limited to results obtained in moderate or cold environment. In this paper, using a soft switching approach, we investigate the effect of weather inhomogeneities on the strength of turbulence hence the channel refractive index under Qatar harsh environment and their influence on the hybrid FSO/RF availability. In this approach, either FSO/RF or simultaneous or none of them can be active. Based on soft switching approach and a finite state Markov Chain (FSMC) process, we model the channel fading for the two links and derive a mathematical expression for the outage probability of the hybrid system. Then, we evaluate the behavior of the hybrid FSO/RF under hazy and harsh weather. Results show that the FSO/RF soft switching renders the system outage probability less than that of each link individually. A soft switching algorithm is being implemented on FPGAs using Raptor code interfaced to the two terminals of a 1Gbps/100 Mbps FSO/RF hybrid system, the first being implemented in the region. Experimental results are compared to the above simulation results.

Keywords: atmospheric turbulence, haze, hybrid FSO/RF, outage probability, refractive index

Procedia PDF Downloads 391
96 An Automatic Feature Extraction Technique for 2D Punch Shapes

Authors: Awais Ahmad Khan, Emad Abouel Nasr, H. M. A. Hussein, Abdulrahman Al-Ahmari

Abstract:

Sheet-metal parts have been widely applied in electronics, communication and mechanical industries in recent decades; but the advancement in sheet-metal part design and manufacturing is still behind in comparison with the increasing importance of sheet-metal parts in modern industry. This paper presents a methodology for automatic extraction of some common 2D internal sheet metal features. The features used in this study are taken from Unipunch ™ catalogue. The extraction process starts with the data extraction from STEP file using an object oriented approach and with the application of suitable algorithms and rules, all features contained in the catalogue are automatically extracted. Since the extracted features include geometry and engineering information, they will be effective for downstream application such as feature rebuilding and process planning.

Keywords: feature extraction, internal features, punch shapes, sheet metal

Procedia PDF Downloads 587
95 Process Simulation of 1-Butene Separation from C4 Mixture by Extractive Distillation

Authors: Muhammad Naeem, Abdulrahman A. Al-Rabiah, Wasif Mughees

Abstract:

Technical mixture of C4 containing 1-butene and n-butane are very close to each other with regard to their boiling points i.e. -6.3°C for 1-butene and -1°C for n-butane. Extractive distillation process is used for the separation of 1-butene from the existing mixture of C4. The solvent is the essential of extractive distillation, and an appropriate solvent plays an important role in the process economy of extractive distillation. Aspen Plus has been applied for the separation of these hydrocarbons as a simulator. Moreover, NRTL activity coefficient model was used in the simulation. This model indicated that the material balances in this separation process were accurate for several solvent flow rates. Mixture of acetonitrile and water used as a solvent and 99% pure 1-butene was separated. This simulation proposed the ratio of the feed to solvent as 1: 7.9 and 15 plates for the solvent recovery column. Previously feed to solvent ratio was more than this and the number of proposed plates were 30, which shows that the separation process can be economized.

Keywords: extractive distillation, 1-butene, aspen plus, ACN solvent

Procedia PDF Downloads 498
94 Mixed Alumina-Silicate Materials for Groundwater Remediation

Authors: Ziyad Abunada, Abir Al-tabbaa

Abstract:

The current work is investigating the effectiveness of combined mixed materials mainly modified bentonites and organoclay in treating contaminated groundwater. Sodium bentonite was manufactured with a quaternary amine surfactant, dimethyl ammonium chloride to produce organoclay (OC). Inorgano-organo bentonite (IOB) was produced by intercalating alkylbenzyd-methyl-ammonium chloride surfactant into sodium bentonite and pillared with chlorohydrol pillaring agent. The materials efficiency was tested for both TEX compounds from model-contaminated water and a mixture of organic contaminants found in groundwater samples collected from a contaminated site in the United Kingdom. The sorption data was fitted well to both Langmuir and Freundlich adsorption models reflecting the double sorption model where the correlation coefficient was greater than 0.89 for all materials. The mixed materials showed higher sorptive capacity than individual material with a preference order of X> E> T and a maximum sorptive capacity of 21.8 mg/g was reported for IOB-OC materials for o-xylene. The mixed materials showed at least two times higher affinity towards a mixture of organic contaminants in groundwater samples. Other experimental parameters such as pH and contact time were also investigated. The pseudo-second-order rate equation was able to provide the best description of adsorption kinetics.

Keywords: modified bentobite, groundwater, adsorption, contaminats

Procedia PDF Downloads 199
93 Evaluation of Fluoride Contents of Kirkuk City's Drinking Water and Its Source: Lesser Zab River and Its Effect on Human Health

Authors: Abbas R. Ali, Safa H. Abdulrahman

Abstract:

In this study, forty samples had been collected from water of Lesser Zab River and drinking water to determine fluoride concentration and show the impact of fluoride on general health of society of Kirkuk city. Estimation of fluoride concentration and determination of its proportion in water samples were performed attentively using a fluoride ion selective electrode. The fluoride concentrations in the Lesser Zab River samples were between 0.0265 ppm and 0.0863 ppm with an average of 0.0451 ppm, whereas the average fluoride concentration in drinking water samples was 0.102 ppm and ranged from 0.010 to 0.289 ppm. A comparison between results obtained with World Health Organization (WHO) show a low concentration of fluoride in the samples of the study. Thus, for health concerns we should increase the concentration of this ion in water of Kirkuk city at least to about (1.0 ppm) and this will take place after fluorination process.

Keywords: fluoride concentration, lesser zab river, drinking water, health society, Kirkuk city

Procedia PDF Downloads 344
92 Melting and Making Zn-Based Alloys and Examine Their Biodegradable and Biocompatible Properties

Authors: Abdulrahman Sumayli

Abstract:

Natural Zinc has many significant biological functions, including developments and sustainable of bones and wound healing. Metallic zinc has recently been explored as potential biomaterials that have preferable biodegradable, biocompatible, and mechanical properties. Pure metal zinc has a preferable physical and mechanical properties for biodegradable and biocompatible applications such as density and modulus of elasticity. The aim of the research is to make different Zn-based metallic alloys and test them effectively to be used as biocompatible and biodegradable materials in the field biomedical application. Microstructure study of the as-cast alloys will be examined using SEM (scanning electron microscope) followed by X-ray diffraction investigated so as to evaluate phase constitution of the designed alloys. After that, immersion test and electrochemical test will be applied to the designed alloys so as to study bio corrosion behaviour of the proposed alloys. Finally, in vitro cytocompatibility well conducted to study biocompatibility of the made alloys.

Keywords: Zn-based alloys, biodegradable and biocompatible materials, cytotoxicity test, neutron synchrotron imaging

Procedia PDF Downloads 108
91 X-Corner Detection for Camera Calibration Using Saddle Points

Authors: Abdulrahman S. Alturki, John S. Loomis

Abstract:

This paper discusses a corner detection algorithm for camera calibration. Calibration is a necessary step in many computer vision and image processing applications. Robust corner detection for an image of a checkerboard is required to determine intrinsic and extrinsic parameters. In this paper, an algorithm for fully automatic and robust X-corner detection is presented. Checkerboard corner points are automatically found in each image without user interaction or any prior information regarding the number of rows or columns. The approach represents each X-corner with a quadratic fitting function. Using the fact that the X-corners are saddle points, the coefficients in the fitting function are used to identify each corner location. The automation of this process greatly simplifies calibration. Our method is robust against noise and different camera orientations. Experimental analysis shows the accuracy of our method using actual images acquired at different camera locations and orientations.

Keywords: camera calibration, corner detector, edge detector, saddle points

Procedia PDF Downloads 375
90 Bit Error Rate Monitoring for Automatic Bias Control of Quadrature Amplitude Modulators

Authors: Naji Ali Albakay, Abdulrahman Alothaim, Isa Barshushi

Abstract:

The most common quadrature amplitude modulator (QAM) applies two Mach-Zehnder Modulators (MZM) and one phase shifter to generate high order modulation format. The bias of MZM changes over time due to temperature, vibration, and aging factors. The change in the biasing causes distortion to the generated QAM signal which leads to deterioration of bit error rate (BER) performance. Therefore, it is critical to be able to lock MZM’s Q point to the required operating point for good performance. We propose a technique for automatic bias control (ABC) of QAM transmitter using BER measurements and gradient descent optimization algorithm. The proposed technique is attractive because it uses the pertinent metric, BER, which compensates for bias drifting independently from other system variations such as laser source output power. The proposed scheme performance and its operating principles are simulated using OptiSystem simulation software for 4-QAM and 16-QAM transmitters.

Keywords: automatic bias control, optical fiber communication, optical modulation, optical devices

Procedia PDF Downloads 160
89 Effect of Elevation and Wind Direction on Silicon Solar Panel Efficiency

Authors: Abdulrahman M. Homadi

Abstract:

As a great source of renewable energy, solar energy is considered to be one of the most important in the world, since it will be one of solutions cover the energy shortage in the future. Photovoltaic (PV) is the most popular and widely used among solar energy technologies. However, PV efficiency is fairly low and remains somewhat expensive. High temperature has a negative effect on PV efficiency and cooling system for these panels is vital, especially in warm weather conditions. This paper presents the results of a simulation study carried out on silicon solar cells to assess the effects of elevation on enhancing the efficiency of solar panels. The study included four different terrains. The study also took into account the direction of the wind hitting the solar panels. To ensure the simulation mimics reality, six silicon solar panels are designed in two columns and three rows, facing to the south at an angle of 30 o. The elevations are assumed to change from 10 meters to 200 meters. The results show that maximum increase in efficiency occurs when the wind comes from the north, hitting the back of the panels.

Keywords: solar panels, elevation, wind direction, efficiency

Procedia PDF Downloads 266
88 Evaluation of Particle Settling in Flow Chamber

Authors: Abdulrahman Alenezi, B. Stefan

Abstract:

Abstract— The investigation of fluids containing particles or filaments includes a category of complex fluids and is vital in both theory and application. The forecast of particle behaviors plays a significant role in the existing technology as well as future technology. This paper focuses on the prediction of the particle behavior through the investigation of the particle disentrainment from a pipe on a horizontal air stream. This allows for examining the influence of the particle physical properties on its behavior when falling on horizontal air stream. This investigation was conducted on a device located at the University of Greenwich's Medway Campus. Two materials were selected to carry out this study: Salt and Glass Beads particles. The shape of the Slat particles is cubic where the shape of the Glass Beads is almost spherical. The outcome from the experimental work were presented in terms of distance travelled by the particles according to their diameters as After that, the particles sizes were measured using Laser Diffraction device and used to determine the drag coefficient and the settling velocity.

Keywords: flow experiment, drag coefficient, Particle Settling, Flow Chamber

Procedia PDF Downloads 100
87 Minimum Ratio of Flexural Reinforcement for High Strength Concrete Beams

Authors: Azad A. Mohammed, Dunyazad K. Assi, Alan S. Abdulrahman

Abstract:

Current ACI 318 Code provides two limits for minimum steel ratio for concrete beams. When concrete compressive strength be larger than 31 MPa the limit of √(fc')/4fy usually governs. In this paper shortcomings related to using this limit was fairly discussed and showed that the limit is based on 90% safety factor and was derived based on modulus of rupture equation suitable for concretes of compressive strength lower than 31 MPa. Accordingly, the limit is nor suitable and critical for concretes of higher compressive strength. An alternative equation was proposed for minimum steel ratio of rectangular beams and was found that the proposed limit is accurate for beams of wide range of concrete compressive strength. Shortcomings of the current ACI 318 Code equation and accuracy of the proposed equation were supported by test data obtained from testing six reinforced concrete beams.

Keywords: concrete beam, compressive strength, minimum steel ratio, modulus of rupture

Procedia PDF Downloads 513
86 Education, Technology and Geopolitics: The Arab World as an Instance

Authors: Abdulrahman Al Lily

Abstract:

This article spans the domains of education, technology and geo-politics. It uses as an instance the Arab scholarship of education and technology, viewing its scholarly community through the geographical lens of regionalism. It enquires into the power relations among scholars in the Arab region and between scholars in the Arab region and their fellows from outside the region. It addresses the research question: to what extent have region-informed factors affected the scholarly community of education and technology in the Arab region? This question was answered by both qualitative and numerical enquiry, analysing documents, interviews and a survey of native Arabic-speaking scholars. Having analysed the data using the grounded theory approach, two categories of power relations among scholars were identified: power relations within a particular region and power relations across regions. Considering these two categories, a theoretical proposition could be posited that there could be power relationships among scholars that exist on a regional basis. The recommendation is therefore that research should further shed light upon the regionalistic (and thus geographically informed political) dynamics of scholarly communities.

Keywords: education, technology, politics, geography, regionalism, Arab

Procedia PDF Downloads 476
85 Digital Design and Practice of The Problem Based Learning in College of Medicine, Qassim University, Saudi Arabia

Authors: Ahmed Elzainy, Abir El Sadik, Waleed Al Abdulmonem, Ahmad Alamro, Homaidan Al-Homaidan

Abstract:

Problem-based learning (PBL) is an educational modality which stimulates critical and creative thinking. PBL has been practiced in the college of medicine, Qassim University, Saudi Arabia, since the 2002s with offline face to face activities. Therefore, crucial technological changes in paperless work were needed. The aim of the present study was to design and implement the digitalization of the PBL activities and to evaluate its impact on students' and tutors’ performance. This approach promoted the involvement of all stakeholders after their awareness of the techniques of using online tools. IT support, learning resources facilities, and required multimedia were prepared. Students’ and staff perception surveys reflected their satisfaction with these remarkable changes. The students were interested in the new digitalized materials and educational design, which facilitated the conduction of PBL sessions and provided sufficient time for discussion and peer sharing of knowledge. It enhanced the tutors for supervision and tracking students’ activities on the Learning Management System. It could be concluded that introducing of digitalization of the PBL activities promoted the students’ performance, engagement and enabled a better evaluation of PBL materials and getting prompt students as well as staff feedback. These positive findings encouraged the college to implement the digitalization approach in other educational activities, such as Team-Based Learning, as an additional opportunity for further development.

Keywords: multimedia in PBL, online PBL, problem-based learning, PBL digitalization

Procedia PDF Downloads 91
84 Applications of Nanoparticles via Laser Ablation in Liquids: A Review

Authors: Fawaz M. Abdullah, Abdulrahman M. Al-Ahmari, Madiha Rafaqat

Abstract:

Laser ablation of any solid target in the liquid leads to fabricate nanoparticles (NPs) with metal or different compositions of materials such as metals, alloys, oxides, carbides, hydroxides. The fabrication of NPs in liquids based on laser ablation has grown up rapidly in the last decades compared to other techniques. Nowadays, laser ablation has been improved to prepare different types of NPs with special morphologies, microstructures, phases, and sizes, which can be applied in various fields. The paper reviews and highlights the different sizes, shapes and application field of nanoparticles that are produced by laser ablation under different liquids and materials. Also, the paper provides a case study for producing a titanium NPs produced by laser ablation submerged in distilled water. The size of NPs is an important parameter, especially for their usage and applications. The size and shape have been analyzed by SEM, (EDAX) was applied to evaluate the oxidation and elements of titanium NPs and the XRD was used to evaluate the phase composition and the peaks of both titanium and some element. SEM technique showed that the synthesized NPs size ranges were between 15-35 nm which can be applied in various field such as annihilator for cancerous cell etc.

Keywords: nanoparticles, laser ablation, titanium NPs, applications

Procedia PDF Downloads 113
83 Surface Modified Thermoplastic Polyurethane and Poly(Vinylidene Fluoride) Nanofiber Based Flexible Triboelectric Nanogenerator and Wearable Bio-Sensor

Authors: Sk Shamim Hasan Abir, Karen Lozano, Mohammed Jasim Uddin

Abstract:

Over the last few years, nanofiber-based triboelectric nanogenerator (TENG) has caught great attention among researchers all over the world due to its inherent capability of converting mechanical energy to usable electrical energy. In this study, poly(vinylidene fluoride) (PVDF) and thermoplastic polyurethane (TPU) nanofiber prepared by Forcespinning® (FS) technique were used to fabricate TENG for self-charging energy storage device and biomechanical body motion sensor. The surface of the TPU nanofiber was modified by uniform deposition of thin gold film to enhance the frictional properties; yielded 254 V open-circuit voltage (Voc) and 86 µA short circuit current (Isc), which were 2.12 and 1.87 times greater in contrast to bare PVDF-TPU TENG. Moreover, the as-fabricated PVDF-TPU/Au TENG was tested against variable capacitors and resistive load, and the results showed that with a 3.2 x 2.5 cm2 active contact area, it can quick charge up to 7.64 V within 30 seconds using a 1.0 µF capacitor and generate significant 2.54 mW power, enough to light 75 commercial LEDs (1.5 V each) by the hand tapping motion at 4 Hz (240 beats per minutes (bpm)) load frequency. Furthermore, the TENG was attached to different body parts to capture distinctive electrical signals for various body movements, elucidated the prospective usability of our prepared nanofiber-based TENG in wearable body motion sensor application.

Keywords: biomotion sensor, forcespinning, nanofibers, triboelectric nanogenerator

Procedia PDF Downloads 62
82 Safety Management and Occupational Injuries Assessing the Mediating Role of Safety Compliance: Downstream Oil and Gas Industry of Malaysia

Authors: Muhammad Ajmal, Ahmad Shahrul Nizam Bin Isha, Shahrina Md. Nordin, Paras Behrani, Al-Baraa Abdulrahman Al-Mekhlafi

Abstract:

This study aims to investigate the impact of safety management practices via safety compliance on occupational injuries in the context of downstream the oil and gas industry of Malaysia. However, it is still challenging for researchers and academicians to control occupational injuries in high-safety-sensitive organizations. In this study response rate was 62%, and 280 valid responses were used for analysis through SmartPLS. The study results revealed that safety management practices (management commitment, safety training, safety promotion policies, workers’ involvement) play a significant role in lowering the rate of accidents in downstream the oil and gas industry via safety compliance. Furthermore, the study results also revealed that safety management practices also reduce safety management costs of organizations, e.g., lost work days and employee absenteeism. Moreover, this study is helpful for safety leaders and managers to understand the importance of safety management practices to lower the ratio of occupational injuries.

Keywords: safety management, safety compliance, occupational injuries, oil and gas, Malaysia

Procedia PDF Downloads 117
81 Synthesis and Characterization of Biodegradable Elastomeric Polyester Amide for Tissue Engineering Applications

Authors: Abdulrahman T. Essa, Ahmed Aied, Omar Hamid, Felicity R. A. J. Rose, Kevin M. Shakesheff

Abstract:

Biodegradable poly(ester amide)s are promising polymers for biomedical applications such as drug delivery and tissue engineering because of their optimized chemical and physical properties. In this study, we developed a biodegradable polyester amide elastomer poly(serinol sebacate) (PSS) composed of crosslinked networks based on serinol and sebacic acid. The synthesized polymers were characterized to evaluate their chemical structures, mechanical properties, degradation behaviors and in vitro cytocompatibility. Analysis of proton nuclear magnetic resonance and Fourier transform infrared spectroscopy revealed the structure of the polymer. The PSS exhibit excellent solubility in a variety of solvents such as methanol, dimethyl sulfoxide and dimethylformamide. More importantly, the mechanical properties of PSS could be tuned by changing the curing conditions. In addition, the 3T3 fibroblast cells cultured on the PSS demonstrated good cell attachment and high viability.

Keywords: biodegradable, biomaterial, elastomer, mechanical properties, poly(serinol sebacate)

Procedia PDF Downloads 315
80 Fluid-Structure Interaction Study of Fluid Flow past Marine Turbine Blade Designed by Using Blade Element Theory and Momentum Theory

Authors: Abu Afree Andalib, M. Mezbah Uddin, M. Rafiur Rahman, M. Abir Hossain, Rajia Sultana Kamol

Abstract:

This paper deals with the analysis of flow past the marine turbine blade which is designed by using the blade element theory and momentum theory for the purpose of using in the field of renewable energy. The designed blade is analyzed for various parameters using FSI module of Ansys. Computational Fluid Dynamics is used for the study of fluid flow past the blade and other fluidic phenomena such as lift, drag, pressure differentials, energy dissipation in water. Finite Element Analysis (FEA) module of Ansys was used to analyze the structural parameter such as stress and stress density, localization point, deflection, force propagation. Fine mesh is considered in every case for more accuracy in the result according to computational machine power. The relevance of design, search and optimization with respect to complex fluid flow and structural modeling is considered and analyzed. The relevancy of design and optimization with respect to complex fluid for minimum drag force using Ansys Adjoint Solver module is analyzed as well. The graphical comparison of the above-mentioned parameter using CFD and FEA and subsequently FSI technique is illustrated and found the significant conformity between both the results.

Keywords: blade element theory, computational fluid dynamics, finite element analysis, fluid-structure interaction, momentum theory

Procedia PDF Downloads 268
79 Development of Computational Approach for Calculation of Hydrogen Solubility in Hydrocarbons for Treatment of Petroleum

Authors: Abdulrahman Sumayli, Saad M. AlShahrani

Abstract:

For the hydrogenation process, knowing the solubility of hydrogen (H2) in hydrocarbons is critical to improve the efficiency of the process. We investigated the H2 solubility computation in four heavy crude oil feedstocks using machine learning techniques. Temperature, pressure, and feedstock type were considered as the inputs to the models, while the hydrogen solubility was the sole response. Specifically, we employed three different models: Support Vector Regression (SVR), Gaussian process regression (GPR), and Bayesian ridge regression (BRR). To achieve the best performance, the hyper-parameters of these models are optimized using the whale optimization algorithm (WOA). We evaluated the models using a dataset of solubility measurements in various feedstocks, and we compared their performance based on several metrics. Our results show that the WOA-SVR model tuned with WOA achieves the best performance overall, with an RMSE of 1.38 × 10− 2 and an R-squared of 0.991. These findings suggest that machine learning techniques can provide accurate predictions of hydrogen solubility in different feedstocks, which could be useful in the development of hydrogen-related technologies. Besides, the solubility of hydrogen in the four heavy oil fractions is estimated in different ranges of temperatures and pressures of 150 ◦C–350 ◦C and 1.2 MPa–10.8 MPa, respectively

Keywords: temperature, pressure variations, machine learning, oil treatment

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78 EFL Learners' Attitudes towards the Proper Pronunciation of English and towards Podcasts as a Facilitator for Proper Pronunciation

Authors: Riam Almaqrn, Abdulrahman Alshabeb

Abstract:

The study aims to examine the attitudes of Saudi students of English towards proper pronunciation and towards podcasts as a facilitator for proper pronunciation. In order to fulfill the purpose of the study, twenty-three students participated in this study. The study used a questionnaire as the main data collection instrument. The questionnaire included two parts, one or proper pronunciation and the other for podcasts. Data analysis showed that the participants, in spite of the low rate of improvement in their pronunciation, had positive attitudes towards proper pronunciation of English. This outcome is compatible with previous studies` results that assert the fact that having a positive attitude towards a particular language and its speakers can improve pronunciation. As for podcasts, students received a total of five podcasts related to their listening and speaking textbook. At the end of the project, students showed high rate of acceptance for podcasts and positive attitudes towards them. The findings proved the usefulness of examining learners` attitudes towards new CALL applications before using them in a practical way. In the light of the findings, pedagogical implications and suggestions were presented for language instructors and academics.

Keywords: CALL, MALL, podcast, learning English

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