Search results for: spiral surface

Authors: Himanshu Chandrakar, Krishnapriya S., Rama Komaragiri, Suja K. J.

Abstract:

Micro coils are significant components for micro magnetic sensors and actuators especially in biomedical devices. Non-spiral planar microcoils of square, hexagonal and octagonal shapes are introduced for the first time in this paper. Comparison between different planar spiral and non-spiral coils are also discussed. The fabrication advantages and low power dissipation of non-spiral structures make them a strong alternative for conventional spiral planar coils. Series resistance of non-spiral coil is lesser than that of spiral coils though magnetic field is slightly lesser for non-spiral coils. Comparison of different planar microcoils shows that the proposed square non-spiral coil gives better performance than other structures.

Keywords: non-spiral planar microcoil, power dissipation, series resistance, spiral

Procedia PDF Downloads 168

Authors: Chris Suma, Yingcai Xiao

Abstract:

This paper presents Parallel Coordinates on a Spiral Surface (PCoSS), a parallel coordinate based interactive visualization method for high-dimensional data, and a test implementation of the method. Plots generated by the test system are compared with those generated by XDAT, a software implementing traditional parallel coordinates. Traditional parallel coordinate plots can be cluttered when the number of data points is large or when the dimensionality of the data is high. PCoSS plots display multivariate data on a 3D spiral surface and allow users to see the whole picture of high-dimensional data with less cluttering. Taking advantage of the 3D display environment in PCoSS, users can further reduce cluttering by zooming into an axis of interest for a closer view or by moving vantage points and by reorienting the viewing angle to obtain a desired view of the plots.

Keywords: human computer interaction, parallel coordinates, spiral surface, visualization

Procedia PDF Downloads 13

Authors: Parthiban S. R.

Abstract:

Spiral heat exchangers are known as excellent heat exchanger because of far compact and high heat transfer efficiency. An innovative spiral heat exchanger based on polymer materials is designed for waste heat recovery process. Such a design based on polymer film technology provides better corrosion and chemical resistance compared to conventional metal heat exchangers. Due to the smooth surface of polymer film fouling is reduced. A new arrangement for flow of hot flue gas and cold fluid is employed for design, flue gas flows in axial path while the cold fluid flows in a spiral path. Heat load recovery achieved with the presented heat exchanger is in the range of 1.5 kW thermic but potential heat recovery about 3.5 kW might be achievable. To measure the performance of the spiral tube heat exchanger, its model is suitably designed and fabricated so as to perform experimental tests. The paper gives analysis of spiral tube heat exchanger.

Keywords: spiral heat exchanger, polymer based materials, fouling factor, heat load

Procedia PDF Downloads 392

Authors: S. R. Parthiban, C. Elajchet Senni

Abstract:

Spiral heat exchangers are known as excellent heat exchanger because of far compact and high heat transfer efficiency. An innovative spiral heat exchanger based on polymer materials is designed for waste heat recovery process. Such a design based on polymer film technology provides better corrosion and chemical resistance compared to conventional metal heat exchangers. Due to the smooth surface of polymer film fouling is reduced. A new arrangement for flow of hot flue gas and cold fluid is employed for design, flue gas flows in axial path while the cold fluid flows in a spiral path. Heat load recovery achieved with the presented heat exchanger is in the range of 1.5 kW thermic but potential heat recovery about 3.5kW might be achievable. To measure the performance of the spiral tube heat exchanger, its model is suitably designed and fabricated so as to perform experimental tests. The paper gives analysis of spiral tube heat exchanger.

Keywords: spiral heat exchanger, polymer based materials, fouling factor, heat load

Procedia PDF Downloads 371

Authors: Kuo-Teng Tsai, You-Min Huang

Abstract:

In this study, the problem of a spiral fin with a period base temperature is analyzed by using the Adomian decomposition method. The Adomian decomposition method is a useful and practice method to solve the nonlinear energy equation which are associated with the heat radiation. The period base temperature is around a mean value. The results including the temperature distribution and the heat flux from the spiral fin base can be calculated directly. The results also discussed the effects of the dimensionless variables for the temperature variations and the total energy transferred from the spiral fin base.

Keywords: spiral fin, period, adomian decomposition method, nonlinear

Procedia PDF Downloads 528

Authors: Surjit Angra, Pooja Rani, Vinod Kumar

Abstract:

In hydro power plant spiral casing and Stay ring is meant to guide the water flow to guide vane and runner. Spiral casing and Stay ring is subjected to static i.e. pressure load as well as fluctuating load acting on the structure due to water hammer effect in water conductor system. Finite element method has been used to calculate stresses on spiral casing and stay ring. These calculations were done for the maximum possible loading under operating condition "LC1 Quick Shut Down”. The design load is reached for the spiral casing and stay ring during the emergency closure of the guide apparatus "LC1 Quick Shut Down”. During this operation the forces from the head cover to the stay ring also reach their maximum.

Keywords: hydro-turbine, spiral casing, stay ring, structural analysis

Procedia PDF Downloads 518

Authors: Hadi Barghlame, M. A. Lotfollahi-Yaghin, Mehdi Mohammad Rezaei, Saeed Eskanderzadeh

Abstract:

In this paper, the capacity of cracking torsion on rectangular and cylindrical beams with spiral and normal stirrups in similar properties are investigated. Also, in the beams with spiral stirrups, stirrups are not wrapping and spiral stirrups similar to normal stirrups in ACI code. Therefore, models of above-mentioned beams have been numerically analyzed under various loads using ANSYS software. In this research, the behavior of rectangular reinforced concrete beams is compared with the cylindrical reinforced concrete beams. The capacity of cracking torsion of rectangular and cylindrical RC beams with spiral and normal stirrups are same. In the other words, the behavior of rectangular RC beams is similar to cylindrical beams.

Keywords: cracking torsion, RC beams, spiral stirrups, normal stirrups

Procedia PDF Downloads 292

Authors: Nima Farshidfar, Navid Daryasafar

Abstract:

In this paper, the seismic stability of reinforced soil slopes is studied using pseudo-dynamic analysis. Equilibrium equations that are applicable to the every kind of failure surface are written using Horizontal Slices Method. In written equations, the balance of the vertical and horizontal forces and moment equilibrium is fully satisfied. Failure surface is assumed to be log-spiral, and non-linear equilibrium equations obtained for the system are solved using Newton-Raphson Method. Earthquake effects are applied as horizontal and vertical pseudo-static coefficients to the problem. To solve this problem, a code was developed in MATLAB, and the critical failure surface is calculated using genetic algorithm. At the end, comparing the results obtained in this paper, effects of various parameters and the effect of using pseudo - dynamic analysis in seismic forces modeling is presented.

Keywords: soil slopes, pseudo-dynamic, genetic algorithm, optimization, limit equilibrium method, log-spiral failure surface

Procedia PDF Downloads 339

Authors: H. G. Noh, H. G. Park, B. S. Kang, J. Kim

Abstract:

Electromagnetic forming process (EMF) is one of high-velocity forming processes using Lorentz force. Advantages of EMF are summarized as improvement of formability, reduction in wrinkling, non-contact forming. In this study, numerical simulations were conducted to determine the practical parameters for EMF process. A 2-D axis-symmetric electromagnetic model was considered based on the spiral type forming coil. In the numerical simulation, RLC circuit coupled with spiral coil was made to consider the design parameters such as system input current and electromagnetic force. In order to deform the sheet in the patter shape die, two types of spiral shape coil were considered to deform the pattern shape sheet. One is a spiral coil that has 6turns with dead zone at centre point. Another is a normal spiral coil without dead zone that has 8 turns. In the electric analysis, input current and magnetic force were compared and then plastic deformation was treated in the mechanical analysis for two coil cases. Deformation behaviour of dead zone coil case has good agreement with pattern shape die. As a result, deformation behaviour could be controlled by giving dead zone at centre of the coil in spiral shape coil case.

Keywords: electromagnetic forming, spiral coil, Lorentz force, manufacturing

Procedia PDF Downloads 307

Authors: T. S. Yang, J. H. Liang

Abstract:

This study applies the finite element method (FEM) to predict maximum forging load, effective stress distribution, effective strain distribution, workpiece temperature temperature in spiral bevel gear forging of AISI 1015. Maximum forging load, effective stress, effective strain, workpiece temperature are determined for different process parameters, such as modules, number of teeth, helical angle and workpiece temperature of the spiral bevel gear hot forging, using the FEM. Finally, the prediction of the power requirement for the spiral bevel gear hot forging of AISI 1015 is determined.

Keywords: spiral bevel gear, hot forging, finite element method

Procedia PDF Downloads 478

Authors: Sen-Yung Lee, Li-Kuo Chou, Chao-Kuang Chen

Abstract:

In this study, the problem of temperature transient response of a spiral fin, with its end insulated, is analyzed with base end subjected to a variation of fluid temperature. The hybrid method of Laplace transforms/Adomian decomposed method-Padé, is applied to the temperature transient response of the fin, the result of the temperature distribution and the heat flux at the base of the spiral fin are obtained, show a good agreement in the physical phenomenon.

Keywords: Laplace transforms, Adomian decomposed method- Padé, transient response, heat transfer

Procedia PDF Downloads 426

Authors: A. Razavykia, A. Esmaeilzadeh, S. Iranmanesh

Abstract:

Many orthopedic implants like proximal humerus cases require lower surface roughness and almost immediate/short lead time surgery. Thus, rapid response from the manufacturer is very crucial. Tool path strategy of milling process has a direct influence on the surface roughness and lead time of medical implant. High-speed milling as promised process would improve the machined surface quality, but conventional or super-abrasive grinding still required which imposes some drawbacks such as additional costs and time. Currently, many CAD/CAM software offers some different tool path strategies to milling free form surfaces. Nevertheless, the users must identify how to choose the strategies according to cutting tool geometry, geometry complexity, and their effects on the machined surface. This study investigates the effect of different tool path strategies for milling a proximal humerus head during finishing operation on stainless steel 316L. Experiments have been performed using MAHO MH700 S vertical milling machine and four machining strategies, namely, spiral outward, spiral inward, and radial as well as zig-zag. In all cases, the obtained surfaces were analyzed in terms of roughness and dimension accuracy compared with those obtained by simulation. The findings provide evidence that surface roughness, dimensional accuracy, and machining time have been affected by the considered tool path strategy.

Keywords: CAD/CAM software, milling, orthopedic implants, tool path strategy

Procedia PDF Downloads 213

Authors: Abdullah M. Almeshal, Mohammad R. Alenezi, Talal H. Alzanki

Abstract:

This paper presents a hybrid fuzzy logic control strategy for a unicycle trajectory following robot on irregular terrains. In literature, researchers have presented the design of path tracking controllers of mobile robots on non-frictional surface. In this work, the robot is simulated to drive on irregular terrains with contrasting frictional profiles of peat and rough gravel. A hybrid fuzzy logic controller is utilised to stabilise and drive the robot precisely with the predefined trajectory and overcome the frictional impact. The controller gains and scaling factors were optimised using spiral dynamics optimisation algorithm to minimise the mean square error of the linear and angular velocities of the unicycle robot. The robot was simulated on various frictional surfaces and terrains and the controller was able to stabilise the robot with a superior performance that is shown via simulation results.

Keywords: fuzzy logic control, mobile robot, trajectory tracking, spiral dynamic algorithm

Procedia PDF Downloads 496

Authors: Zhang Kehan, Du Luona

Abstract:

Wireless power transfer (WPT) systems have been widely investigated for advantages of convenience and safety compared to traditional plug-in charging systems. The research contents include impedance matching, circuit topology, transfer distance et al. for improving the efficiency of WPT system, which is a decisive factor in the practical application. What is more, coil structures such as spiral circular coil and helical coil with variable distance between two turns also have indispensable effects on the efficiency of WPT systems. This paper compares the efficiency of WPT systems utilizing spiral or helical coil with variable distance between two turns, and experimental results show that efficiency of spiral circular coil with an optimum distance between two turns is the highest. According to efficiency formula of resonant WPT system with series-series topology, we introduce M²/R₋₁ to measure the efficiency of spiral circular coil and helical coil WPT system. If the distance between two turns s is too close, proximity effect theory shows that the induced current in the conductor, caused by a variable flux created by the current flows in the skin of vicinity conductor, is the opposite direction of source current and has assignable impart on coil resistance. Thus in two coil structures, s affects coil resistance. At the same time, when the distance between primary and secondary coils is not variable, s can also make the influence on M to some degrees. The aforementioned study proves that s plays an indispensable role in changing M²/R₋₁ and then can be adjusted to find the optimum value with which WPT system achieves the highest efficiency. In actual application situations of WPT systems especially in underwater vehicles, miniaturization is one vital issue in designing WPT system structures. Limited by system size, the largest external radius of spiral circular coil is 100 mm, and the largest height of helical coil is 40 mm. In other words, the turn of coil N changes with s. In spiral circular and helical structures, the distance between each two turns in secondary coil is set as a constant value 1 mm to guarantee that the R2 is not variable. Based on the analysis above, we set up spiral circular coil and helical coil model using COMSOL to analyze the value of M²/R₋₁ when the distance between each two turns in primary coil sp varies from 0 mm to 10 mm. In the two structure models, the distance between primary and secondary coils is 50 mm and wire diameter is chosen as 1.5 mm. The turn of coil in secondary coil are 27 in helical coil model and 20 in spiral circular coil model. The best value of s in helical coil structure and spiral circular coil structure are 1 mm and 2 mm respectively, in which the value of M²/R₋₁ is the largest. It is obviously to select spiral circular coil as the first choice to design the WPT system for that the value of M²/R₋₁ in spiral circular coil is larger than that in helical coil under the same condition.

Keywords: distance between two turns, helical coil, spiral circular coil, wireless power transfer

Procedia PDF Downloads 348

Authors: Getachew Demeissie Ayalew, Yongtao Sun, Yang Yang

Abstract:

The spiral welded pipe manufacturing industry requires strict production standards for automated grinders for welding seams. However, traditional grinding machines in this sector are insufficient due to a lack of quality control protocols and inconsistent performance. This research aims to improve the quality of spiral welded pipes by developing intelligent automated abrasive belt grinding equipment. The system has equipped with six degrees of freedom (6 DOF) KUKA KR360 industrial robots, enabling concurrent grinding operations on both internal and external welds. The grinding robot control system is designed with a PLC, and a human-machine interface (HMI) system is employed for operations. The system includes an electric speed controller, data connection card, DC driver, analog amplifier, and HMI for input data. This control system enables the grinding of spiral welded pipe. It ensures consistent production quality and cost-effectiveness by reducing the product life cycle and minimizing risks in the working environment.

Keywords: Intelligent Systems, Spiral Welded Pipe, Grinding, Industrial Robot, End-Effector, PLC Controller System, 3D Laser Sensor, HMI.

Procedia PDF Downloads 297

Authors: Ki-Seok Kwon, Heung-Youl Kim

Abstract:

This research evaluated fire resistances of high-strengthened reinforced concrete (RC) column, spiral wire rope which applied with 60, and 100MPa. The fire resistance test of RC column with loading condition was conducted following the ISO 834 (3 hours). This experiment set mixing of fiber (PP fiber, Steel fiber) and types of horizontal reinforcement as a variable of reinforcement method. The fire resistance test measured the main steel bar’s max and mean temperatures also the shrinkage and shrinking ratio of columns(500 X 500 X 3,000mm) with loadings. As a result, the specimen of 60MPa attained three hours fire resistance with only spiral wire rope. Also, the specimen of 100MPa must be reinforced with fibers and spiral wire rope to attain three hours fire resistance.

Keywords: reinforced concrete column, high strength concrete, wire rope, fire resistance test

Procedia PDF Downloads 328

Authors: M. Javahar, H. B. Dong

Abstract:

Single crystal components manufactured using Ni-base Superalloys are routinely used in the hot sections of aero engines and industrial gas turbines due to their outstanding high temperature strength, toughness and resistance to degradation in corrosive and oxidative environments. To control the quality of the single crystal turbine blades, particular attention has been paid to grain selection, which is used to obtain the single crystal morphology from a plethora of columnar grains. For this purpose, different designs of grain selectors are employed and the most common type is the spiral grain selector. A typical spiral grain selector includes a starter block and a spiral (helix) located above. It has been found that the grains with orientation well aligned to the thermal gradient survive in the starter block by competitive grain growth while the selection of the single crystal grain occurs in the spiral part. In the present study, 2D spiral selectors with different geometries were designed and produced using a state-of-the-art Bridgeman Directional Solidification casting furnace to investigate the competitive growth during grain selection in 2d grain selectors. The principal advantage of using a 2-D selector is to facilitate the wax injection process in investment casting by enabling significant degree of automation. The automation within the process can be derived by producing 2D grain selector wax patterns parts using a split die (metal mold model) coupled with wax injection stage. This will not only produce the part with high accuracy but also at an acceptable production rate.

Keywords: grain selector, single crystal, directional solidification, CMSX-4 superalloys, investment casting

Procedia PDF Downloads 589

Authors: Prudhvinath Reddy Ankireddy, Narasimha Mangadoddy

Abstract:

Spiral concentrators are commonly used in various industries, including mineral and coal processing, to efficiently separate materials based on their density and size. In these concentrators, a mixture of solid particles and fluid (usually water) is introduced as feed at the top of a spiral channel. As the mixture flows down the spiral, centrifugal and gravitational forces act on the particles, causing them to stratify based on their density and size. Spiral flows exhibit complex fluid dynamics, and interactions involve multiple phases and components in the process. Understanding the behavior of these phases within the spiral concentrator is crucial for achieving efficient separation. An experimental bi-component particle interaction study is conducted in this work utilizing magnetite (heavier density) and silica (lighter density) with different proportions processed in the spiral concentrator. The observation separation reveals that denser particles accumulate towards the inner region of the spiral trough, while a significant concentration of lighter particles are found close to the outer edge. The 5th turn of the spiral trough is partitioned into five zones to achieve a comprehensive distribution analysis of bicomponent particle segregation. Samples are then gathered from these individual streams using an in-house sample collector, and subsequent analysis is conducted to assess component segregation. Along the trough, there was a decline in the concentration of coarser particles, accompanied by an increase in the concentration of lighter particles. The segregation pattern indicates that the heavier coarse component accumulates in the inner zone, whereas the lighter fine component collects in the outer zone. The middle zone primarily consists of heavier fine particles and lighter coarse particles. The zone-wise results reveal that there is a significant fraction of segregation occurs in inner and middle zones. Finer magnetite and silica particles predominantly accumulate in outer zones with the smallest fraction of segregation. Additionally, numerical simulations are also carried out using the computational fluid dynamics (CFD) model based on the volume of fluid (VOF) approach incorporating the RSM turbulence model. The discrete phase model (DPM) is employed for particle tracking, thereby understanding the particle segregation of magnetite and silica along the spiral trough.

Keywords: spiral concentrator, bi-component particle segregation, computational fluid dynamics, discrete phase model

Procedia PDF Downloads 67

Authors: Saman R. Khan, Najma Sadiq

Abstract:

Silencing of opinions is an important aspect of Spiral of Silence theory however its applicability in rape-themed dramas requires investigation. This study focuses on the portrayal of female rape victim protagonists in Pakistani dramas and the factors influencing their behavior after rape. A quantitative content analysis was conducted on two prime-time dramas which directly dealt with female rape victims. Results indicate that the female protagonists who faced rape are shown as silent and submissive characters who are unable to communicate about their ordeal due to fear of social isolation. These findings lend support to the Spiral of Silence theory and indicate that the theory’s basic elements (inability to express opinions and fear of social isolation) exist in these TV dramas.

Keywords: gender stereotyping, rape victims, the spiral of silence, TV dramas

Procedia PDF Downloads 170

Authors: Delara Soltani, Sajad Alimohammadi, Tim Persoons

Abstract:

Microfluidic technology reveals a new area of research in drug delivery, biomedical diagnostics, and the food and chemical industries. Mixing is an essential part of microfluidic devices. There is a need for fast and homogeneous mixing in microfluidic devices. On the other hand, mixing is difficult to achieve in microfluidic devices because of the size and laminar flow in these devices. In this study, a hybrid passive micromixer of a curved channel with obstacles inside the channel is designed. The computational fluid dynamic method is employed to solve governing equations. The results show that using obstacles can improve mixing efficiency in spiral micromixers. the effects of Reynolds number, number, and position of baffles are investigated. In addition, the effect of baffles on pressure drop is presented. this novel micromixer has the potential to utilize in microfluidic devices.

Keywords: CFD, micromixer, microfluidics, spiral, reynolds number

Procedia PDF Downloads 91

Authors: M. A. Aleem, M. S. Awan

Abstract:

Flat spiral coil for electromagnetic forming system has been modelled in FEMM 4.2 software. Copper strip was chosen as the material for designing the actuator coil. Relationship between height to width ratio (S-factor) of the copper strip and coil’s performance has been studied. Magnetic field intensities, eddy currents, and Lorentz force were calculated for the coils that were designed using six different 'S-factor' values (0.65, 0.75, 1.05, 1.25, 1.54 and 1.75), keeping the cross-sectional area of strip the same. Results obtained through simulation suggest that actuator coil with S-factor ~ 1 shows optimum forming performance as it exerts maximum Lorentz force (84 kN) on work piece. The same coils were fabricated and used for electromagnetic sheet forming experiments. Aluminum 6061 sheets of thickness 1.5 mm have been formed using different voltage levels of capacitor bank. Smooth forming profiles were obtained with dome heights 28, 35 and 40 mm in work piece at 800, 1150 and 1250 V respectively.

Keywords: FEM modelling, electromagnetic forming, spiral coil, Lorentz force

Procedia PDF Downloads 286

Authors: Gi-Hoon Yang, JongHan Ha, MyungGu Yeo, JaeYoon Lee, SeungHyun Ahn, Hyeongjin Lee, HoJun Jeon, YongBok Kim, Minseong Kim, GeunHyung Kim

Abstract:

Tissue engineering scaffolds must be biocompatible and biodegradable, provide adequate mechanical strength and cell attachment site for proliferation and differentiation. Furthermore, the scaffold morphology (such as pore size, porosity and pore interconnectivity) plays an important role. The electrospinning process has been widely used to fabricate micro/nano-sized fibres. Electrospinning allows for the fabrication of non-woven meshes containing micro- to nano-sized fibers providing high surface-to-volume area for cell attachment. Due to its advantageous characteristics, electrospinning is a useful method for skin, cartilage, bone, and nerve regeneration. In this study, we fabricated PCL scaffolds (SP) consisting of spiral-like struts using 3D melt-plotting system and micro/nanofibers using direct electrospinning writing. By altering the conditions of the conventional melt-plotting method, spiral-like struts were generated. Then, micro/nanofibers were deposited selectively. The control scaffold composed of perpendicular PCL struts was fabricated using the conventional melt-plotting method to compare the cellular activities. The effect on the attached cells (osteoblast-like cells (MG63)) was evaluated depending on the bending instability of the struts. The SP scaffolds showed enhanced biological properties such as initial cell attachment, proliferation and osteogenic differentiation. These results suggest that the SP scaffolds has potential as a bioengineered substitute for soft and hard tissue regeneration.

Keywords: cell attachment, electrospinning, mechanical strength, melt-plotting

Procedia PDF Downloads 318

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

Abstract:

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

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

Procedia PDF Downloads 299

Authors: Rahul Singha, D. Vakula

Abstract:

This paper presents a corrugated antipodal vivaldi antenna with improved performance by using negative index metamaterial (NIM) of the Archimedean spiral design. A single layer NIM piece is placed perpendicular middle of the two arm of the proposed antenna. The antenna size is 30×60×0.787 mm3 operating at 8GHz. The simulated results of NIM corrugated antipodal vivaldi antenna show that the gain and directivity has increased up to 1.2dB and 1dB respectively. The HPBW is increased by 90 with the reflection coefficient less than ‒10 dB from 4.7 GHz to 11 GHz for UWB application.

Keywords: Negative Index Metamaterial (NIM), Ultra Wide Band (UWB), Half Power Beam Width (HPBW), vivaldi antenna

Procedia PDF Downloads 624

Authors: Subhash Chander, Tejinder Kumar Jindal

Abstract:

Due to its simplicity, Pulse detonation engine technology has recently emerged as a future aerospace propulsion technology. In this paper, we studied various parameters affecting the performance of Pulse detonation engine (PDE) like tube length for proper deflagration to detonation transition (DDT), tube diameter (combustion tube), tube length, Shelkin spiral, Cell size, Equivalence ratio of fuel used etc. We have discussed various techniques for reducing the length of pulse tube by using various DDT enhancing devices. The effect of length of the tube from 40 mm to 3000 mm and diameter from 10 mm to 100 mm has been analyzed. The fuel used is C2H2 and oxidizer is O2. The results are processed in MATLAB for drawing valid conclusions.

Keywords: pulse detonation engine (PDE), deflagration to detonation (DDT), Schelkin spiral, cell size (λ)

Procedia PDF Downloads 573

Authors: Shahinaz El-Shourbagy El-Shourbagy, Ahmed M. E Ossman Ossman, Ashraf El-Mohamady El-Mohamady

Abstract:

Objective: To investigate if there is a role of sildenafil citrate (Viagra) in the treatment of infertile couples for idiopathic cause. Design: An observational study. Setting: Infertility outpatient clinic of Tanta University Hospital Egypt. Patient(s): 50 unexplained infertility women {endometrial thickness (EM) and the mean resistance index (RI)} compared to 50 fertile control group attended for check-up in the same period and receiving no treatment. Intervention(s): unexplained infertility women were given 25 mg of sildenafil citrate suppositories four times per day for seven days starting from the 5th day of the menstrual cycle for three cycles. Main Outcome Measures: EM and RI of endometrial spiral artery were assessed by transvaginal color-pulsed Doppler ultrasound in unexplained infertility women before and after sildenafil citrate treatment and compared with control. The conception rate and pregnancy outcome were recorded in the two groups. Result(s): Women with unexplained infertility had significantly thinner endometrium and a higher spiral artery resistance index, meaning lower peri-implantation blood flow than the fertile controls. Sildenafil citrate treated women showed a statistically significant increase in endometrial thickness (p < 0.001) and a significant decrease in the mean spiral artery resistance index (p < 0.001) giving a better conception rate. Conclusion: Sildenafil citrate suppositories treatment enhance the endometrial blood flow through decreasing spiral artery resistance index 'RI' and consequently improve endometrial growth and receptivity in cases of unexplained infertility thus giving a better conception rate.

Keywords: Unexplained infertility, endometrial blood flow, endome¬trial receptivity, color-pulsed Doppler ultrasound; RI (resis¬tance index, Sildenafil citrate (Viagra)

Procedia PDF Downloads 217

Authors: PR

Abstract:

Renewable energy is a sustainable substitute to fossil fuels, which are depleting and attributing to global warming as well as greenhouse gas emissions. Renewable energy innovations including solar, wind, and geothermal have grown significantly and play a critical role in meeting energy demands recently. Consequently, Artificial Intelligence (AI) could further enhance the benefits of renewable energy systems. The combination of renewable technologies and AI could facilitate the development of smart grids that can better manage energy distribution and storage. AI thus has the potential to optimize the efficiency and reliability of renewable energy systems, reduce costs, and improve their overall performance. The conventional methods of using smart micro-grids are to connect these micro-grids in series or parallel or a combination of series and parallel. Each of these methods has its advantages and disadvantages. In this study, the proposal of using the method of connecting microgrids in a spiral manner is investigated. One of the important reasons for choosing this type of structure is the two-way reinforcement and exchange of each inner layer with the outer and upstream layer. With this model, we have the ability to increase energy from a small amount to a significant amount based on exponential functions. The geometry used to close the smart microgrids is based on nature.This study provides an overview of the applications of algorithms and models of AI as well as its advantages and challenges in renewable energy systems.

Keywords: artificial intelligence, renewable energy sources, spiral model, optimize

Procedia PDF Downloads 13

Authors: Daniela Brioschi, Rovilson Mafalda, Silvia Titotto

Abstract:

In the present days, packages are considered a fundamental element in the commercialization of products and services. A good package is capable of helping to attract new customers and also increasing a product’s purchase intent. In this scenario, packaging design emerges as an important tool, since products and design of their packaging are so interconnected that they are no longer seen as separate elements. Packaging design is, in fact, capable of generating desire for a product. The packaging market for cosmetics, especially makeup market, has also been experiencing an increasing level of sophistication and requirements. Considering packaging represents an important link of communication with the final user and plays a significant role on the sales process, it is of great importance that packages accomplish not only with functional requirements but also with the visual appeal. One of the possibilities for the design of packages and, in this context, packages for make-up, is the bioinspired design – or biomimicry. The bio-inspired design presents a promising paradigm for innovation in both design and sustainable design, by using biological system analogies to develop solutions. It has gained importance as a widely diffused movement in design for environmentally conscious development and is also responsible for several useful and innovative designs. As eye mascara packages are also part of the constant evolution on the design for cosmetics area and the traditional packages present the disadvantage of product drying along time, this project aims to develop a new and innovative package for this product, by using a selected bioinspired design methodology during the development process and also suitable computational tools. In order to guide the development process of the package, it was chosen the spiral methodology, conceived by The Biomimicry Institut, which consists of a reliable tool, since it was based on traditional design methodologies. The spiral design comprises identification, translation, discovery, abstraction, emulation and evaluation steps, that can work iteratively as the process develops as a spiral. As support tool for packaging, 3D modelling is being used by the software Inventor Autodesk Inventor 2018. Although this is an ongoing research, first results showed that spiral methodology design, together with Autodesk Inventor, consist of suitable instruments for the bio-inspired design process, and also nature proved itself to be an amazing and inexhaustible source of inspiration.

Keywords: bio-inspired design, design methodology, packaging, cosmetics

Procedia PDF Downloads 188

Authors: Seyedeh Sepideh Amini, Navideh Aghaei Amirkhizi, Seyedeh Paniz Amini, Seyed Soheil Sayyahi, Mohammad Reza Davar Panah

Abstract:

CT-Scan is one of the lateral and sectional imaging methods that produce 3D-images with use of rotational x-ray tube around central axis. This study is about evaluation and calculation of effective doses around heart organs such as breast, lung and liver with CT-Scan 128 dual sources with TLD_100 and RANDO Phantom by spiral, flash and conventional protocols. In results, it is showed that in spiral protocol organs have maximum effective dose and minimum in flash protocol. Thus flash protocol advised for children and risk persons.

Keywords: X-ray computed tomography, dosimetry, TLD-100, RANDO, phantom

Procedia PDF Downloads 476

Authors: L. Tonia, I. Daglis, W. Kurth

Abstract:

The sound of the universe creates an affinity with the sounds of music. The analysis of the sound of space focuses on the existence of a tone material, the microstructure and macrostructure, and the form of the sound through the signals recorded during the flight of the spacecraft Van Allen Probes and Cassini’s mission. The sound becomes from the frequencies that belong to electromagnetic waves. Plasma Wave Science Instrument and Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) recorded the signals from space. A transformation of that signals to audio gave the opportunity to study and analyze the sound. Due to the fact that the musical tone pitch has a frequency and every electromagnetic wave produces a frequency too, the creation of a musical score, which appears as the sound of space, can give information about the form, the symmetry, and the harmony of the sound. The conversion of space radio emissions to audio provides a number of tone pitches corresponding to the original frequencies. Through the process of these sounds, we have the opportunity to present a music score that “composed” from space. In this score, we can see some basic features associated with the music form, the structure, the tone center of music material, the construction and deconstruction of the sound. The structure, which was built through a harmonic world, includes tone centers, major and minor scales, sequences of chords, and types of cadences. The form of the sound represents the symmetry of a spiral movement not only in micro-structural but also to macro-structural shape. Multiple glissando sounds in linear and polyphonic process of the sound, founded in magnetic fields around Earth, Saturn, and Jupiter, but also a spiral movement appeared on the spectrogram of the sound. Whistles, Auroral Kilometric Radiations, and Chorus emissions reveal movements similar to musical excerpts of works by contemporary composers like Sofia Gubaidulina, Iannis Xenakis, EinojuhamiRautavara.

Keywords: space sound analysis, spiral, space music, analysis

Procedia PDF Downloads 178