Search results for: thin section study
50307 Single Phase Fluid Flow in Series of Microchannel Connected via Converging-Diverging Section with or without Throat
Authors: Abhishek Kumar Chandra, Kaushal Kishor, Wasim Khan, Dhananjay Singh, M. S. Alam
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Single phase fluid flow through series of uniform microchannels connected via transition section (converging-diverging section with or without throat) was analytically and numerically studied to characterize the flow within the channel and in the transition sections. Three sets of microchannels of diameters 100, 184, and 249 μm were considered for investigation. Each set contains 10 numbers of microchannels of length 20 mm, connected to each other in series via transition sections. Transition section consists of either converging-diverging section with throat or without throat. The effect of non-uniformity in microchannels on pressure drop was determined by passing water/air through the set of channels for Reynolds number 50 to 1000. Compressibility and rarefaction effects in transition sections were also tested analytically and numerically for air flow. The analytical and numerical results show that these configurations can be used in enhancement of transport processes. However, converging-diverging section without throat shows superior performance over with throat configuration.Keywords: contraction-expansion flow, integrated microchannel, microchannel network, single phase flow
Procedia PDF Downloads 27750306 Superhydrophobic Behavior of SnO₂-TiO₂ Composite Thin Films
Authors: Debarun Dhar Purkayastha, Talinungsang
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SnO₂-TiO₂ nanocomposite thin films were prepared by the sol-gel method on borosilicate glass substrate. The films were annealed at a temperature of 300ᵒC, 400ᵒC, and 500ᵒC respectively for 2h in the air. The films obtained were further modified with stearic acid in order to decrease the surface energy. The X-ray diffraction patterns for the SnO₂-TiO₂ thin films after annealing at different temperatures can be indexed to the mixture of TiO₂ (rutile and anatase) and SnO₂ (tetragonal) phases. The average crystallite size calculated from Scherrer’s formula is found to be 6 nm. The SnO₂-TiO₂ thin films were hydrophilic which on modification with stearic acid exhibit superhydrophobic behavior. The increase in hydrophobicity of SnO₂ film with stearic acid modification is attributed to the change in surface energy of the film. The films exhibit superhydrophilic behavior under UV irradiation for 1h. Thus, it is observed that stearic acid modified surfaces are superhydrophobic but convert into superhydrophilic on being subjected to UV irradiation. SnO₂-TiO₂ thin films have potential for self-cleaning applications because of photoinduced hydrophilicity under UV irradiation.Keywords: nanocomposite, self-cleaning, superhydrophobic, surface energy
Procedia PDF Downloads 17650305 TiN/TiO2 Nanostructure Coating on Glass Substrate
Authors: F. Dabir, R. Sarraf-Mamoory, N. Riahi-Noori
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In this work, a nanostructured TiO2 layer was coated onto a FTO-less glass substrate using screen printing technique for back contact DSSC application. Then, titanium nitride thin film was applied on TiO2 layer by plasma assisted chemical vapor deposition (PACVD) as charge collector layer. The microstructure of prepared TiO2 layer was characterized by SEM. The sheet resistance, microstructure and elemental composition of titanium nitride thin films were analysed by four point probe, SEM, and EDS, respectively. TiO2 layer had porous nanostructure. The EDS analysis of TiN thin film showed presence of chlorine impurity. Sheet resistance of TiN thin film was 30 Ω/sq. With respect to the results, PACVD TiN can be a good candidate as a charge collector layer in back contacts DSSC.Keywords: TiO2, TiN, charge collector, DSSC
Procedia PDF Downloads 46050304 Effect of Substrate Temperature on Some Physical Properties of Doubly doped Tin Oxide Thin Films
Authors: Ahmet Battal, Demet Tatar, Bahattin Düzgün
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Various transparent conducting oxides (TCOs) are mostly used much applications due to many properties such as cheap, high transmittance/electrical conductivity etc. One of the clearest among TCOs, indium tin oxide (ITO), is the most widely used in many areas. However, as ITO is expensive and very low regarding reserve, other materials with suitable properties (especially SnO2 thin films) are be using instead of it. In this report, tin oxide thin films doubly doped with antimony and fluorine (AFTO) were deposited by spray at different substrate temperatures on glass substrate. It was investigated their structural, optical, electrical and luminescence properties. The substrate temperature was varied from 320 to 480 ˚C at the interval of 40 (±5) ºC. X-ray results were shown that the films are polycrystalline with tetragonal structure and oriented preferentially along (101), (200) and (210) directions. It was observed that the preferential orientations of crystal growth are not dependent on substrate temperature, but the intensity of preferential orientation was increased with increasing substrate temperature until 400 ºC. After this substrate temperature, they decreased. So, substrate temperature impact structure of these thin films. It was known from SEM analysis, the thin films have rough and homogenous and the surface of the films was affected by the substrate temperature i.e. grain size are increasing with increasing substrate temperature until 400 ºC. Also, SEM and AFM studies revealed the surface of AFTO thin films to be made of nanocrystalline particles. The average transmittance of the films in the visible range is 70-85%. Eg values of the films were investigated using the absorption spectra and found to be in the range 3,20-3,93 eV. The electrical resistivity decreases with increasing substrate temperature, then the electrical resistivity increases. PL spectra were found as a function of substrate temperature. With increasing substrate temperature, emission spectra shift a little bit to a UV region. Finally, tin oxide thin films were successfully prepared by this method and a spectroscopic characterization of the obtained films was performed. It was found that the films have very good physical properties. It was concluded that substrate temperature impacts thin film structure.Keywords: thin films, spray pyrolysis, SnO2, doubly doped
Procedia PDF Downloads 46850303 Nonlinear Modelling and Analysis of Piezoelectric Smart Thin-Walled Structures in Supersonic Flow
Authors: Shu-Yang Zhang, Shun-Qi Zhang, Zhan-Xi Wang, Xian-Sheng Qin
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Thin-walled structures are used more and more widely in modern aircrafts and some other structures in aerospace field nowadays. Accompanied by the wider applications, the vibration of the structures has been a bigger problem. Because of the direct and converse piezoelectric effect, piezoelectric materials combined to host thin-walled structures, named as piezoelectric smart structures, can be an effective way to suppress the vibration. So, an accurate model for piezoelectric thin-walled structures in air flow is necessary and important. In our recent work, an electromechanical coupling nonlinear aerodynamic finite element model of piezoelectric smart thin-walled structures is built based on the Reissner-Mindlin plate theory and first-order piston theory for aerodynamic pressure of supersonic flow. Von Kármán type nonlinearity is considered in the present model. Finally, the model is validated by experimental and numerical results from the literature, which can describe the vibration of the structures in supersonic flow precisely.Keywords: piezoelectric smart structures, aerodynamic, geometric nonlinearity, finite element analysis
Procedia PDF Downloads 38450302 An Inverse Approach for Determining Creep Properties from a Miniature Thin Plate Specimen under Bending
Authors: Yang Zheng, Wei Sun
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This paper describes a new approach which can be used to interpret the experimental creep deformation data obtained from miniaturized thin plate bending specimen test to the corresponding uniaxial data based on an inversed application of the reference stress method. The geometry of the thin plate is fully defined by the span of the support, l, the width, b, and the thickness, d. Firstly, analytical solutions for the steady-state, load-line creep deformation rate of the thin plates for a Norton’s power law under plane stress (b → 0) and plane strain (b → ∞) conditions were obtained, from which it can be seen that the load-line deformation rate of the thin plate under plane-stress conditions is much higher than that under the plane-strain conditions. Since analytical solution is not available for the plates with random b-values, finite element (FE) analyses are used to obtain the solutions. Based on the FE results obtained for various b/l ratios and creep exponent, n, as well as the analytical solutions under plane stress and plane strain conditions, an approximate, numerical solutions for the deformation rate are obtained by curve fitting. Using these solutions, a reference stress method is utilised to establish the conversion relationships between the applied load and the equivalent uniaxial stress and between the creep deformations of thin plate and the equivalent uniaxial creep strains. Finally, the accuracy of the empirical solution was assessed by using a set of “theoretical” experimental data.Keywords: bending, creep, thin plate, materials engineering
Procedia PDF Downloads 46650301 Pipeline Construction in Oil and Gas Fields as per Kuwait Oil Company Procedures
Authors: Jasem Al-Safran
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Nowadays Oil and Gas industry considered as one of the biggest industries around the world although it caused a lot of pollution to the world and it caused many damages to the mankind and the other creatures around the globe it still one of the biggest industries, it create millions of careers around the globe which reduced the poorness level and make the mankind life’s much more comfortable you may compare the humans life before the exploration of the oil and after the oil industries development. Construction project’s consist of 3 major sections also we call them EPC projects the first section is the detailed engineering, the second section is the procurements section and finally is the Construction section, each section required a specialized work force with a different skills in order to handle the work load for example in the oil sector and depending on the nature of the project and the project size the Construction team required mechanical engineer, civil engineer, electrical engineer and instrumentation engineer, also a work site supervisor for each disciplines also a huge number of labors, technicians and many equipment’s.Keywords: Construction, EPC, Project, Work force
Procedia PDF Downloads 10450300 Advanced Approach to Analysis the Thin Strip Profile in Cold Rolling of Pair Roll Crossing and Shifting Mill Using an Arbitrary Lagrangian-Eulerian Technique
Authors: Abdulrahman Aljabri, Essam R. I. Mahmoud, Hamad Almohamedi, Zhengyi Jiang
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Cold rolled thin strip has received intensive attention through technological and theoretical progress in the rolling process, as well as researchers have focused on its control during rolling as an essential parameter for producing thinner strip with good shape and profile. An advanced approach has been proposed to analysis the thin strip profile in cold rolling of pair roll crossing and shifting mill using Finite Element Analysis (FEA) with an ALE technique. The ALE (Arbitrary Lagrangian-Eulerian) techniques to enable more flexibility of the ALE technique in the adjustment of the finite element mesh, which provides a significant tool for simulating the thin strip under realistic rolling process constraint and provide accurate model results. The FEA can provide theoretical basis for the 3D model of controlling the strip shape and profile in thin strip rolling, and deliver an optimal rolling process parameter, and suggest corrective changes during cold rolling of thin strip.Keywords: pair roll crossing, work roll shifting, strip shape and profile, finite element modeling
Procedia PDF Downloads 9050299 Cold Formed Steel Sections: Analysis, Design and Applications
Authors: A. Saha Chaudhuri, D. Sarkar
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In steel construction, there are two families of structural members. One is hot rolled steel and another is cold formed steel. Cold formed steel section includes steel sheet, strip, plate or flat bar. Cold formed steel section is manufactured in roll forming machine by press brake or bending operation. Cold formed steel (CFS), also known as Light Gauge Steel (LGS). As cold formed steel is a sustainable material, it is widely used in green building. Cold formed steel can be recycled and reused with no degradation in structural properties. Cold formed steel structures can earn credits for green building ratings such as LEED and similar programs. Cold formed steel construction satisfies international demand for better, more efficient and affordable buildings. Cold formed steel sections are used in building, car body, railway coach, various types of equipment, storage rack, grain bin, highway product, transmission tower, transmission pole, drainage facility, bridge construction etc. Various shapes of cold formed steel sections are available, such as C section, Z section, I section, T section, angle section, hat section, box section, square hollow section (SHS), rectangular hollow section (RHS), circular hollow section (CHS) etc. In building construction cold formed steel is used as eave strut, purlin, girt, stud, header, floor joist, brace, diaphragm and covering for roof, wall and floor. Cold formed steel has high strength to weight ratio and high stiffness. Cold formed steel is non shrinking and non creeping at ambient temperature, it is termite proof and rot proof. CFS is durable, dimensionally stable and non combustible material. CFS is economical in transportation and handling. At present days cold formed steel becomes a competitive building material. In this paper all these applications related present research work are described and how the CFS can be used as blast resistant structural system that is examined.Keywords: cold form steel sections, applications, present research review, blast resistant design
Procedia PDF Downloads 14050298 Interpretation as Ontological Determination and Negotiation
Authors: Nicolas Cuevas-Alvear
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The subject of this paper is the concept of interpretation. Its purpose is to expose the need for a new concept of interpretation and to trace the construction route of interpretation as determination and negotiation. The thesis it defends is that interpretation is the determination of events and the negotiation of those determinations in communication. To meet its objective, this manuscript is divided into five sections. The first section introduces the subject and the need for a new concept of interpretation. The second section explicitly formulates the research questions and the objectives of the project for the construction of a new concept of interpretation. The third section presents the state of the art, specifically, the theory of Radical interpretation proposed by Donald Davidson and the theory of the Hermeneutic Circle proposed by Hans Georg Gadamer. In addition, in this section, there is a reconstruction of Ernst Cassirer's explanation of language as a symbolic form. The fourth section is an explanation of the proposal based on the theories presented. Specifically: language as a symbolic form explains interpretation as a determination of events using objective, subjective and intersubjective elements, and these three elements are negotiated in interpretation as communication. The last section is the bibliography proposed to carry out the project.Keywords: interpretation, metaphysics, semantics, Donald Davidson, ERNST Cassirer
Procedia PDF Downloads 18750297 Technology Computer Aided Design Simulation of Space Charge Limited Conduction in Polycrystalline Thin Films
Authors: Kunj Parikh, S. Bhattacharya, V. Natarajan
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TCAD numerical simulation is one of the most tried and tested powerful tools for designing devices in semiconductor foundries worldwide. It has also been used to explain conduction in organic thin films where the processing temperature is often enough to make homogeneous samples (often imperfect, but homogeneously imperfect). In this report, we have presented the results of TCAD simulation in multi-grain thin films. The work has addressed the inhomogeneity in one dimension, but can easily be extended to two and three dimensions. The effect of grain boundaries has mainly been approximated as barriers located at the junction between two adjacent grains. The effect of the value of grain boundary barrier, the bulk traps, and the measurement temperature have been investigated.Keywords: polycrystalline thin films, space charge limited conduction, Technology Computer-Aided Design (TCAD) simulation, traps
Procedia PDF Downloads 20950296 Dielectric Properties of Thalium Selenide Thin Films at Radio Wave Frequencies
Authors: Onur Potok, Deniz Deger, Kemal Ulutas, Sahin Yakut, Deniz Bozoglu
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Thalium Selenide (TlSe) is used for optoelectronic devices, pressure sensitive detectors, and gamma-ray detectors. The TlSe samples were grown as large single crystals using the Stockbarger-Bridgman method. The thin films, in the form of Al/TlSe/Al, were deposited on the microscope slide in different thicknesses (300-3000 Å) using thermal evaporation technique at 10-5 Torr. The dielectric properties of (TlSe) thin films, capacitance (C) and dielectric loss factor (tanδ), were measured in a frequency range of 10-105 Hz, and temperatures between 213K and 393K via Broadband Dielectric Spectroscopy analyzer. The dielectric constant (ε’) and the dielectric loss (ε’’) of the thin films were derived from measured parameters (C and tanδ). These results showed that the dielectric properties of TlSe thin films are frequency and temperature dependent. The capacitance and the dielectric constant decrease with increasing frequency and decreasing temperature. The dielectric loss of TlSe thin films decreases with increasing frequency, on the other hand, they increase with increasing temperature and increasing thicknesses. There is two relaxation region in the investigated frequency and temperature interval. These regions can be called as low and high-frequency dispersion regions. Low-frequency dispersion region can be attributed to the polarization of the main part of the chain structure of TlSe while high-frequency dispersion region can be attributed to the polarization of side parts of the structure.Keywords: thin films, thallium selenide, dielectric spectroscopy, binary compounds
Procedia PDF Downloads 14850295 RBS Characteristic of Cd1−xZnxS Thin Film Fabricated by Vacuum Deposition Method
Authors: N. Dahbi, D. E. Arafah
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Cd1−xZnxS thins films have been fabricated from ZnS/CdS/ZnS multilayer thin film systems, by using the vacuum deposition method; the Rutherford back-scattering (RBS) technique have been applied in order to determine the: structure, composition, depth profile, and stoichiometric of these films. The influence of the chemical and heat treatments on the produced films also have been investigated; the RBS spectra of the films showed that homogenous Cd1−xZnxS can be synthesized with x=0.45.Keywords: Cd1−xZnxS, chemical treatment, depth profile, heat treatment, RBS, RUMP simulation, thin film, vacuum deposition, ZnS/CdS/ZnS
Procedia PDF Downloads 21550294 Flexural Behavior of Composite Hybrid Beam Models Combining Steel Inverted T-Section and RC Flange
Authors: Abdul Qader Melhem, Hacene Badache
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This paper deals with the theoretical and experimental study of shear connection via simple steel reinforcement shear connectors, which are steel reinforcing bars bent into L-shapes, instead of commonly used headed studs. This suggested L-shape connectors are readily available construction material in steel reinforcement. The composite section, therefore, consists of steel inverted T-section being embedded within a lightly reinforced concrete flange at the top slab as a unit. It should be noted that the cross section of these composite models involves steel inverted T-beam, replacing the steel top flange of a standard commonly employed I-beam section. The paper concentrates on the elastic and elastic-plastic behavior of these composite models. Failure modes either by cracking of concrete or shear connection be investigated in details. Elastic and elastoplastic formulas of the composite model have been computed for different locations of NA. Deflection formula has been derived, its value was close to the test value. With a supportive designing curve, this curve is valuable for both designing engineers and researchers. Finally, suggested designing curves and valuable equations will be presented. A check is made between theoretical and experimental outcomes.Keywords: composite, elastic-plastic, failure, inverted T-section, L-Shape connectors
Procedia PDF Downloads 21950293 Structural Analysis of Phase Transformation and Particle Formation in Metastable Metallic Thin Films Grown by Plasma-Enhanced Atomic Layer Deposition
Authors: Pouyan Motamedi, Ken Bosnick, Ken Cadien, James Hogan
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Growth of conformal ultrathin metal films has attracted a considerable amount of attention recently. Plasma-enhanced atomic layer deposition (PEALD) is a method capable of growing conformal thin films at low temperatures, with an exemplary control over thickness. The authors have recently reported on growth of metastable epitaxial nickel thin films via PEALD, along with a comprehensive characterization of the films and a study on the relationship between the growth parameters and the film characteristics. The goal of the current study is to use the mentioned films as a case study to investigate the temperature-activated phase transformation and agglomeration in ultrathin metallic films. For this purpose, metastable hexagonal nickel thin films were annealed using a controlled heating/cooling apparatus. The transformations in the crystal structure were observed via in-situ synchrotron x-ray diffraction. The samples were annealed to various temperatures in the range of 400-1100° C. The onset and progression of particle formation were studied in-situ via laser measurements. In addition, a four-point probe measurement tool was used to record the changes in the resistivity of the films, which is affected by phase transformation, as well as roughening and agglomeration. Thin films annealed at various temperature steps were then studied via atomic force microscopy, scanning electron microscopy and high-resolution transmission electron microscopy, in order to get a better understanding of the correlated mechanisms, through which phase transformation and particle formation occur. The results indicate that the onset of hcp-to-bcc transformation is at 400°C, while particle formations commences at 590° C. If the annealed films are quenched after transformation, but prior to agglomeration, they show a noticeable drop in resistivity. This can be attributed to the fact that the hcp films are grown epitaxially, and are under severe tensile strain, and annealing leads to relaxation of the mismatch strain. In general, the results shed light on the nature of structural transformation in nickel thin films, as well as metallic thin films, in general.Keywords: atomic layer deposition, metastable, nickel, phase transformation, thin film
Procedia PDF Downloads 32250292 Effect of Addition of Surfactant to the Surface Hydrophilicity and Photocatalytic Activity of Immobilized Nano TiO2 Thin Films
Authors: Eden G. Mariquit, Winarto Kurniawan, Masahiro Miyauchi, Hirofumi Hinode
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This research studied the effect of adding surfactant to the titanium dioxide (TiO2) sol-gel solution that was used to immobilize TiO2 on glass substrates by dip coating technique using TiO2 sol-gel solution mixed with different types of surfactants. After dipping into the TiO2 sol, the films were calcined and produced pure anatase crystal phase. The thickness of the thin film was varied by repeating the dip and calcine cycle. The prepared films were characterized using FE-SEM, TG-DTA, and XRD, and its photocatalytic performances were tested on degradation of an organic dye, methylene blue. Aside from its phocatalytic performance, the photo-induced hydrophilicity of thin TiO2 films surface was also studied. Characterization results showed that the addition of surfactant gave rise to characteristic patterns on the surface of the TiO2 thin film which also affects the photocatalytic activity. The addition of CTAB to the TiO2 dipping solution had a negative effect because the calcination temperature was not high enough to burn all the surfactants off. As for the surface wettability, the addition of surfactant also affected the induced surface hydrophilicity of the TiO2 films when irradiated under UV light.Keywords: photocatalysis, surface hydrophilicity, TiO2 thin films, surfactant
Procedia PDF Downloads 41250291 Electronic Structure Studies of Mn Doped La₀.₈Bi₀.₂FeO₃ Multiferroic Thin Film Using Near-Edge X-Ray Absorption Fine Structure
Authors: Ghazala Anjum, Farooq Hussain Bhat, Ravi Kumar
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Multiferroic materials are vital for new application and memory devices, not only because of the presence of multiple types of domains but also as a result of cross correlation between coexisting forms of magnetic and electrical orders. In spite of wide studies done on multiferroic bulk ceramic materials their realization in thin film form is yet limited due to some crucial problems. During the last few years, special attention has been devoted to synthesis of thin films like of BiFeO₃. As they allow direct integration of the material into the device technology. Therefore owing to the process of exploration of new multiferroic thin films, preparation, and characterization of La₀.₈Bi₀.₂Fe₀.₇Mn₀.₃O₃ (LBFMO3) thin film on LaAlO₃ (LAO) substrate with LaNiO₃ (LNO) being the buffer layer has been done. The fact that all the electrical and magnetic properties are closely related to the electronic structure makes it inevitable to study the electronic structure of system under study. Without the knowledge of this, one may never be sure about the mechanism responsible for different properties exhibited by the thin film. Literature review reveals that studies on change in atomic and the hybridization state in multiferroic samples are still insufficient except few. The technique of x-ray absorption (XAS) has made great strides towards the goal of providing such information. It turns out to be a unique signature to a given material. In this milieu, it is time honoured to have the electronic structure study of the elements present in the LBFMO₃ multiferroic thin film on LAO substrate with buffer layer of LNO synthesized by RF sputtering technique. We report the electronic structure studies of well characterized LBFMO3 multiferroic thin film on LAO substrate with LNO as buffer layer using near-edge X-ray absorption fine structure (NEXAFS). Present exploration has been performed to find out the valence state and crystal field symmetry of ions present in the system. NEXAFS data of O K- edge spectra reveals a slight shift in peak position along with growth in intensities of low energy feature. Studies of Mn L₃,₂- edge spectra indicates the presence of Mn³⁺/Mn⁴⁺ network apart from very small contribution from Mn²⁺ ions in the system that substantiates the magnetic properties exhibited by the thin film. Fe L₃,₂- edge spectra along with spectra of reference compound reveals that Fe ions are present in +3 state. Electronic structure and valence state are found to be in accordance with the magnetic properties exhibited by LBFMO/LNO/LAO thin film.Keywords: magnetic, multiferroic, NEXAFS, x-ray absorption fine structure, XMCD, x-ray magnetic circular dichroism
Procedia PDF Downloads 14950290 Behavior of Composite Reinforced Concrete Circular Columns with Glass Fiber Reinforced Polymer I-Section
Authors: Hiba S. Ahmed, Abbas A. Allawi, Riyadh A. Hindi
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Pultruded materials made of fiber-reinforced polymer (FRP) come in a broad range of shapes, such as bars, I-sections, C-sections, and other structural sections. These FRP materials are starting to compete with steel as structural materials because of their great resistance, low self-weight, and cheap maintenance costs-especially in corrosive conditions. This study aimed to evaluate the effectiveness of Glass Fiber Reinforced Polymer (GFRP) of the hybrid columns built by combining (GFRP) profiles with concrete columns because of their low cost and high structural efficiency. To achieve the aims of this study, nine circular columns with a diameter of (150 mm) and a height of (1000mm) were cast using normal concrete with compression strength equal to (35 MPa). The research involved three different types of reinforcement: hybrid circular columns type (IG) with GFRP I-section and 1% of the reinforcement ratio of steel bars, hybrid circular columns type (IS) with steel I-section and 1% of the reinforcement ratio of steel bars, (where the cross-section area of I-section for GFRP and steel was the same), compared with reference column (R) without I-section. To investigate the ultimate capacity, axial and lateral deformation, strain in longitudinal and transverse reinforcement, and failure mode of the circular column under different loading conditions (concentric and eccentric) with eccentricities of 25 mm and 50 mm, respectively. In the second part, an analytical finite element model will be performed using ABAQUS software to validate the experimental results.Keywords: composite, columns, reinforced concrete, GFRP, axial load
Procedia PDF Downloads 4750289 Medical Aspects, Professionalism, and Bioethics of Anesthesia in Caesarean Section on Self-Request
Authors: Nasrudin Andi Mappaware, Muh. Wirawan Harahap, Erlin Syahril, Farah Ekawati Mulyadi
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The increasing trend of cesarean sections, especially those performed on self-request without medical indications, presents complex dilemmas related to medical aspects, professionalism, and bioethics. This study aims to investigate the medical, professional, and bioethical considerations surrounding anesthesia in cesarean sections performed on self-request without medical indications. We report the case of a 27-year-old woman, G1P0A0 gravid 38 weeks, admitted to the hospital for a planned cesarean section on request for the reason that she could not tolerate pain and requested on a date that corresponded to the date and month of her mother's birth. Cesarean section on patient request fulfills the principle of autonomy, which states that patients have the right to themselves. However, this medical procedure is still considered no safer and riskier even though medical technology has developed rapidly. Furthermore, anesthesia during cesarean section at self-request without medical indications is a dilemma for anesthesiologists considering the risks and complications of anesthesia for both the fetus and the mother. The trend in increasing the number of cesarean sections is influenced by patient reasons such as not being able to tolerate pain, trust factors, and worry about damage to the birth canal.Keywords: anesthesia, bioethics, cesarean section, self-request, professionalism
Procedia PDF Downloads 3650288 A Study on Traction Motor Design for Obtaining the Maximum Traction Force of Tram-Train
Authors: Geochul Jeong, In-Gun Kim, Hyun-Seok Hong, Dong-Woo Kang, Ju Lee
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This study is about IPMSM design for obtaining the maximum traction force of Tram-Train. Tram-Train is a Tram and Train-combined railway vehicles, which operates at a maximum speed of 70km/h in the city section (Tram section) and at a maximum speed of 150km/h in the out-of-city section (Train section). For this reason, tram-train was designed to be an IPMSM (Interior Permanent Synchronous Motor) with a wide range of speed variation. IPMSM’s magnetic path varies depending on the shape of rotor and in this case, the power characteristics are different in the constant torque area and the flux weakening area. Therefore, this study suggests a method to improve Tram-Train’s traction force, based on the relationship between magnetic torque and reluctance torque. The suggested method was applied through IPMSM rotor shape design and electromagnetic field finite element method was conducted to verify the validity of the suggested method.Keywords: tram-train, traction motor, IPMSM, synchronous motor, railway vehicles
Procedia PDF Downloads 46650287 Enhanced Optical and Electrical Properties of P-Type AgBiS₂ Energy Harvesting Materials as an Absorber of Solar Cell by Copper Doping
Authors: Yasaman Tabari-Saadi, Kaiwen Sun, Jialiang Huang, Martin Green, Xiaojing Hao
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Optical and electrical properties of p-type AgBiS₂ absorber material have been improved by copper doping on silver sites. X-Ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis suggest that complete solid solutions of Ag₁₋ₓCuₓBiS₂ thin film have been formed. The carrier concentration of pure AgBiS₂ thin film deposited by the chemical process is 4.5*E+14 cm⁻³, and copper doping leads to the improved carrier concentration despite the semiconductor AgBiS₂ remains p-type semiconductor. Copper doping directly changed the absorption coefficient and increased the optical band gap (~1.5eV), which makes it a promising absorber for thin-film solar cell applications.Keywords: copper doped, AgBiS₂, thin-film solar cell, carrier concentration, p-type semiconductor
Procedia PDF Downloads 11650286 Numerical Crashworthiness Investigations of a Full-Scale Composite Fuselage Section
Authors: Redouane Lombarkia
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To apply a new material model developed and validated for plain weave fabric CFRP composites usually used in stanchions in sub-cargo section in aircrafts. This work deals with the development of a numerical model of the fuselage section of commercial aircraft based on the pure explicit finite element method FEM within Abaqus/Explicit commercial code. The aim of this work is the evaluation of the energy absorption capabilities of a full-scale composite fuselage section, including sub-cargo stanchions, Drop tests were carried out from a free fall height of about 5 m and impact velocity of about 6 m∕s. To asses, the prediction efficiency of the proposed numerical modeling procedure, a comparison with literature existed experimental results was performed. We demonstrate the efficiency of the proposed methodology to well capture crash damage mechanisms compared to experimental resultsKeywords: crashworthiness, fuselage section, finite elements method (FEM), stanchions, specific energy absorption SEA
Procedia PDF Downloads 8750285 Purity Monitor Studies in Medium Liquid Argon TPC
Authors: I. Badhrees
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This paper is an attempt to describe some of the results that had been found through a journey of study in the field of particle physics. This study consists of two parts, one about the measurement of the cross section of the decay of the Z particle in two electrons, and the other deals with the measurement of the cross section of the multi-photon absorption process using a beam of laser in the Liquid Argon Time Projection Chamber. The first part of the paper concerns the results based on the analysis of a data sample containing 8120 ee candidates to reconstruct the mass of the Z particle for each event where each event has an ee pair with PT(e) > 20GeV, and η(e) < 2.5. Monte Carlo templates of the reconstructed Z particle were produced as a function of the Z mass scale. The distribution of the reconstructed Z mass in the data was compared to the Monte Carlo templates, where the total cross section is calculated to be equal to 1432 pb. The second part concerns the Liquid Argon Time Projection Chamber, LAr TPC, the results of the interaction of the UV Laser, Nd-YAG with λ= 266mm, with LAr and through the study of the multi-photon ionization process as a part of the R&D at Bern University. The main result of this study was the cross section of the process of the multi-photon ionization process of the LAr, σe = 1.24±0.10stat±0.30sys.10 -56cm4.Keywords: ATLAS, CERN, KACST, LArTPC, particle physics
Procedia PDF Downloads 34150284 Comparison of ANN and Finite Element Model for the Prediction of Ultimate Load of Thin-Walled Steel Perforated Sections in Compression
Authors: Zhi-Jun Lu, Qi Lu, Meng Wu, Qian Xiang, Jun Gu
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The analysis of perforated steel members is a 3D problem in nature, therefore the traditional analytical expressions for the ultimate load of thin-walled steel sections cannot be used for the perforated steel member design. In this study, finite element method (FEM) and artificial neural network (ANN) were used to simulate the process of stub column tests based on specific codes. Results show that compared with those of the FEM model, the ultimate load predictions obtained from ANN technique were much closer to those obtained from the physical experiments. The ANN model for the solving the hard problem of complex steel perforated sections is very promising.Keywords: artificial neural network (ANN), finite element method (FEM), perforated sections, thin-walled Steel, ultimate load
Procedia PDF Downloads 34450283 On the Lithology of Paleocene-Lower Eocene Deposits of the Achara-Trialeti Fold Zone: The Lesser Caucasus
Authors: Nino Kobakhidze, Endi Varsimashvili, Davit Makadze
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The Caucasus is a link of the Alpine-Himalayan fold belt and involves the Greater Caucasus and the Lesser Caucasus fold systems and the Intermountain area. The study object is located within the northernmost part of the Lesser Caucasus orogen, in the eastern part of Achara-Trialeti fold -thrust belt. This area was rather well surveyed in 70th of the twentieth century in terms of oil-and-gas potential, but to our best knowledge, detailed sedimentological studies have not been conducted so far. In order to fill this gap, the authors of the present thesis started research in this direction. One of the objects selected for the research was the deposits of the Kavtura river valley situated on the northern slope of the Trialeti ridge. Paleocene-Lower Eocene deposits known in scientific literature as ‘Borjomi Flysch’ (Turbidites) are exposed in the mentioned area. During the research, the following methodologies were applied: selection of key cross sections, a collection of rock samples, microscopic description of thin sections, mineralogical and petrological analysis of material and identification of trace fossils. The study of Paleocene-Lower Eocene deposits starts with Kavtura river valley in the east, where they are well characterized by microfauna. The cross-section of the deposits starts with Danian variegated marlstone conformably overlain by the alternation of thick and thin-bedded sandstones (thickness 40-50 cm). They are continued with interbedded of thin-bedded sandstones and shales(thickness 4-5 m). On the sole surface of sandstones ichnogenera ‘Helmintopsis’ and ‘Scolicia’ are recorded and within the bed –‘Chondrites’ is found. Towards the Riverhead, there is a 1-2 m gap in sedimentation; then again the Paleocene-Lower Eocene sediments crop out. They starting with alternation of grey-green medium-grained sandstones and shales enclosing dark color plant detritus. They are overlain by the interbedded of calcareous sandstones and marls, where the thickness of sandstones is variable (20-70 cm). Ichnogenus – ‘Scolicia’ is found here. Upwards the above-mentioned deposits pass into Middle Eocenian volcanogenic-sedimentary suits. In the Kavtura river valley, the thickness of the Paleocene-Lower Eocene deposits is 300-400 m. In the process of research, the following activities are conducted: the facial analysis of host rocks, correlation of the study section with other cross sections and interpretation of depositional environment of the area. In the area the authors have found and described ichnogenera; their preliminary determination have shown that they belong to pre-depositional (‘Helmintopsis’) and post-depositional (‘Chondrites’) forms. As known, during the Cretaceous-Paleogene time, the Achara-Trialeti fold-thrust belt extensional basin was the accumulation area with great thicknesses (from shallow to deep marine sediments). It is confirmed once more by the authors investigations preliminary results of paleoichnological studies inclusive.Keywords: flysh deposits, lithology, The Lesser Caucasus, trace fossils
Procedia PDF Downloads 15950282 Transparent and Solution Processable Low Contact Resistance SWCNT/AZONP Bilayer Electrodes for Sol-Gel Metal Oxide Thin Film Transistor
Authors: Su Jeong Lee, Tae Il Lee, Jung Han Kim, Chul-Hong Kim, Gee Sung Chae, Jae-Min Myoung
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The contact resistance between source/drain electrodes and semiconductor layer is an important parameter affecting electron transporting performance in the thin film transistor (TFT). In this work, we introduced a transparent and the solution prossable single-walled carbon nanotube (SWCNT)/Al-doped ZnO nano particle (AZO NP) bilayer electrodes showing low contact resistance with indium-oxide (In2O3) sol gel thin film. By inserting low work function AZO NPs into the interface between the SWCNTs and the In2O3 which has a high energy barrier, we could obtain an electrical Ohmic contact between them. Finally, with the SWCNT-AZO NP bilayer electrodes, we successfully fabricated a TFT showing a field effect mobility of 5.38 cm2/V∙s at 250 °C.Keywords: single-walled carbon nanotube (SWCNT), Al-doped ZnO (AZO) nanoparticle, contact resistance, thin-film transistor (TFT)
Procedia PDF Downloads 52250281 Sensing Characteristics of Gold Nanoparticles Decorated Sputtered Tin Oxide Thin Films as Nitrogen Oxide Sensor
Authors: Qasem Drmosh, Zain Yamai, Amar Mohamedkhair, Abdulmajid Hendi
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In recent years, there has been a growing interest in the reduction of the nitrogen oxides NOx (NO2, NO) gases resulting from automotive or combustion emissions. Recently, metal additives in nanometer dimension onto the surface of SnO2 nanorods, nanowires and nanotubes sensitizer to further increase the sensor response have been used. In contrast, there is a lack study focused on modifying the surface of SnO2 thin films by nanoparticles. The challenge in case of thin films is how to fabricate these nanoparticles on the surfaces in cost-effective method, high purity as well as without hampering electrical and topographical properties. Here in this report, a simple and facile strategy has been demonstrated to acquire high sensitive and fast response NO2 gas sensor. Structural, electrical, morphological, optical, and compositional properties of the fabricated sensors were investigated through different analytical technique including X-ray diffraction (XRD), Field emission scanning emission microscope (FESEM) and X-ray photoelectron spectroscopy (XPS). The sensing performance of the prepared sensors are studied at different temperatures for various concentrations of NO2 and compared with pristine SnO2 film.Keywords: NO2 sensor, SnO2, sputtering, thin films
Procedia PDF Downloads 20750280 Water Equivalent from the Point of View of Fast Neutron Removal Cross-Section
Authors: Mohammed Alrajhi
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Radiological properties of gel dosimeters and phantom materials are often evaluated in terms of effective atomic number, electron density, photon mass attenuation coefficient, photon mass energy absorption coefficient and total stopping power of electrons. To evaluate the water equivalence of such materials for fast neutron attenuation 19 different types of gel dosimeters and phantom materials were considered. Macroscopic removal cross-sections for fast neutrons (ΣR cm-1) have been calculated for a range of ferrous-sulphate and polymeric gel dosimeters using Nxcom Program. The study showed that the value of ΣR/ρ (cm2.g-1) for all polymer gels were in close agreement (1.5- 2.8%) with that of water. As such, the slight differences in ΣR/ρ between water and gels are small and may be considered negligible. Also, the removal cross-section of the studied phantom materials were very close (~ ±1.5%) to that of water except bone (cortical) which had about 38% variation. Finally, the variation of removal cross-section with hydrogen content was studied.Keywords: cross-section, neutron, photon, coefficient, mathematics
Procedia PDF Downloads 36750279 Structural and Optoelectronic Properties of Monovalent Cation Doping PbS Thin Films
Authors: Melissa Chavez Portillo, Hector Juarez Santiesteban, Mauricio Pacio Castillo, Oscar Portillo Moreno
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Nanocrystalline Li-doped PbS thin films have been deposited by chemical bath deposition technique. The goal of this work is to study the modification of the optoelectronic and structural properties of Lithium incorporation. The increase of Li doping in PbS thin films leads to an increase of band gap in the range of 1.4-2.3, consequently, quantum size effect becomes pronounced in the Li-doped PbS films, which lead to a significant enhancement in the optical band gap. Doping shows influence in the film growth and results in a reduction of crystallite size from 30 to 14 nm. The refractive index was calculated and a relationship with dielectric constant was investigated. The dc conductivities of Li-doped and undoped samples were measured in the temperature range 290-340K, the conductivity increase with increase of Lithium content in the PbS films.Keywords: doping, quantum confinement, optical band gap, PbS
Procedia PDF Downloads 37650278 Relaxation Behavior of Biorenewable Waterborne Castor Oil-Based Polyurethane-Lignin Thin Films
Authors: Samy Madbouly
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The relaxation behavior of biorenewable castor oil-based polyurethane-lignin thin films synthesized in homogenous waterborne dispersions was investigated as a function of concentration at different temperatures and frequencies using broadband dielectric relaxation spectroscopy (BDRS). The molecular dynamics of the glass relaxation process and the local relaxation process of the PU-LS thin films were studied over a wide range of temperatures (-70 to 30 ℃) and frequencies (5 × 10−2 to 0.5 × 107 Hz) for different lignin concentration. Four relaxation processes have been observed namely; ?-, β-, γ-relaxations and ionic conductivity for pure castor oil-based PU and castor oil-lignin-based PU thin films at different temperatures and frequencies ranges. The Vogel-Fulcher-Tammann equation was found to be well described the temperature dependence of the characteristic relaxation times of the ?-relaxation process. However, on the other hand, the molecular dynamics of both β- and γ-relaxation processes were given by the Arrhenius equation. The incorporation of lignin into the castor oil-based PU significantly increased the glass transition temperature and primitivity of the thin films. In addition, the broadness, intensity, and molecular dynamics of the only observed ?-relaxation process were found to be strongly dependent on lignin concentration.Keywords: castor oil, lignin, polyurethane, dielectric, dispersions
Procedia PDF Downloads 197