Search results for: serial position curves

Authors: Sasibhushan Yengala, Nelson Muthu, Subramani Kanagaraj

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The abstract reports on the design related to a modular and affordable standing cum sitting device to meet the requirements of paraplegic patients of the different physiques. Paraplegic patients need the assistance of an external arrangement to the lower limbs and trunk to help patients adopt the correct posture while standing abreast gravity. This support can be from a tilt table or a standing frame which the patient can use to stay in a vertical posture. Standing frames are devices fitting to support a person in a weight-bearing posture. Commonly, these devices support and lift the end-user in shifting from a sitting position to a standing position. The merits of standing for a paraplegic patient with a spinal injury are numerous. Even when there is limited control on muscles that ordinarily support the user using the standing frame in a vertical position, the standing stance improves the blood pressure, increases bone density, improves resilience and scope of motion, and improves the user's feelings of well-being by letting the patient stand. One limitation with standing frames is that these devices are typically function definitely; cannot be used for different purposes. Therefore, users are often compelled to purchase more than one of these devices, each being purposefully built for definite activities. Another concern frequent in standing frames is manoeuvrability; it is crucial to provide a convenient adjustment scope for all users. Thus, there is a need to provide a standing frame with multiple uses that can be economical for a larger population. There is also a need to equip added readjustment means in a standing frame to lessen the shear and to accommodate a broad range of users. The proposed Versatile Standing cum Sitting Device (VSD) is designed to change from standing to a comfortable sitting position using a series of mechanisms. First, a locking mechanism is provided to lock the VSD in a standing stance. Second, a dampening mechanism is provided to make sure that the VSD shifts from a standing to a sitting position gradually when the lock mechanism gets disengaged. An adjustment option is offered for the height of the headrest via the use of lock knobs. This device can be used in clinics for rehabilitation purposes irrespective of patient's anthropometric data due to its modular adjustments. It can facilitate the patient's daily life routine while in therapy and giving the patient the comfort to sit when tired. The device also provides the availability of rehabilitation to a common person.

Keywords: paraplegic, rehabilitation, spinal cord injury, standing frame

Procedia PDF Downloads 182

Authors: Mohhamed El Habib Labdouni

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Introduction: Co-infection with VIH and tuberculosis poses one of the major ongoing challenges for global TB and AIDS prevention and control. The objective of this study is to raise the issue of the resurgence of TB, in People living with VIH supported in a referent center in western Algeria. Its epidemiological, clinical, biological and radiological new trends, and to compare the mortality rate between early and delayed ART. Methods: It was a prospective study, during 36 months from the 01st/01/2012 to 31st/12/2014, by identifying and analyzing cases of TB-VIH co-infection. Our population was devised in two groups/ early ART and delayed ART. The primary and secondary endpoints were analyzed with Kaplan-Meier curves and log-rank test the period of follow up, which was fixed at 300 weeks. Results: Sixty cases of co-infection TB -VIH were enrolled in our study: 78.3% had pulmonary tuberculosis associated with extra-pulmonary, 13.3% had only pulmonary tuberculosis and 08.3% presented strictly extra-pulmonary TB. The clinical particularity of this co-infection is the frequency of serious localization such us: pleural 23.3%, peritoneal 31.7%, and meningeal suffusion 13.3%.y-.biologicaly we notice the predominance both of pancytopenia and leucoanemia, hyponatremia in 38,6% and hypokalemia in 19,3%. By analyzing Kaplan-Meier survival curves, we notice that early ART initiation is associated with a significant reduction of all-cause mortality (p = 0,000), and we have identified several prognostic factors such as hypokalemia hyponatremia, leukocytosis thrombopenemia leucothrombopenia (p = 0,005). Conclusion: Our study confirms most of the results reported in the literature. Early ART initiation reduces the rate of all-cause mortality, despite the probability of the occurrence of TB-IRIS.

Keywords: TB-HIV co-infection, early ART, hyponatremia, extrapulmonary tuberculosis

Procedia PDF Downloads 164

Authors: Hesam Khajehsaeid, Naeimeh Alagheband

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Magnetorheological fluids (MRF) are a category of smart materials. They exhibit a reversible change from a Newtonian-like fluid to a semi-solid state upon application of an external magnetic field. In contrast to ordinary fluids, MRFs can tolerate shear stresses up to a threshold value called yield stress which strongly depends on the strength of the magnetic field, magnetic particles volume fraction and temperature. Even beyond the yield, a magnetic field can increase MR fluid viscosity up to several orders. As yield stress is an important parameter in the design of MR devices, in this work, the effects of magnetic field intensity and magnetic particle concentration on the yield stress of MRFs are investigated. Four MRF samples with different particle concentrations are developed and tested through flow-ramp analysis to obtain the flow curves at a range of magnetic field intensity as well as shear rate. The viscosity of the fluids is determined by means of the flow curves. The results are then used to determine the yield stresses by means of the steady stress sweep method. The yield stresses are then determined by means of a modified form of the dipole model as well as empirical models. The exponential distribution function is used to describe the orientation of particle chains in the dipole model under the action of the external magnetic field. Moreover, the modified dipole model results in a reasonable distribution of chains compared to previous similar models.

Keywords: magnetorheological fluids, yield stress, particles concentration, dipole model

Procedia PDF Downloads 154

Authors: Milagros Jaén-Vargas, Javier García Martínez, Karla Miriam Reyes Leiva, María Fernanda Trujillo-Guerrero, Francisco Fernandes, Sérgio Barroso Gonçalves, Miguel Tavares Silva, Daniel Simões Lopes, José Javier Serrano Olmedo

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Human Activity Recognition (HAR) is having a growing impact in creating new applications and is responsible for emerging new technologies. Also, the use of wearable sensors is an important key to exploring the human body's behavior when performing activities. Hence, the use of these dispositive is less invasive and the person is more comfortable. In this study, a database that includes three activities is used. The activities were acquired from inertial measurement unit sensors (IMU) and motion capture systems (MOCAP). The main objective is differentiating the performance from four Deep Learning (DL) models: Deep Neural Network (DNN), Convolutional Neural Network (CNN), Recurrent Neural Network (RNN) and hybrid model Convolutional Neural Network-Long Short-Term Memory (CNN-LSTM), when considering acceleration, velocity and position and evaluate if integrating the IMU acceleration to obtain velocity and position represent an increment in performance when it works as input to the DL models. Moreover, compared with the same type of data provided by the MOCAP system. Despite the acceleration data is cleaned when integrating, results show a minimal increase in accuracy for the integrated signals.

Keywords: HAR, IMU, MOCAP, acceleration, velocity, position, feature maps

Procedia PDF Downloads 74

Authors: Guanqiao Wang, Hongyang Yu

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There is a lot of repetitive work in the traditional construction industry. These repetitive tasks can significantly improve production efficiency by replacing manual tasks with robots. There- fore, robots appear more and more frequently in the construction industry. Navigation and positioning are very important tasks for construction robots, and the requirements for accuracy of positioning are very high. Traditional indoor robots mainly use radiofrequency or vision methods for positioning. Compared with ordinary robots, the indoor plastering robot needs to be positioned closer to the wall for wall plastering, so the requirements for construction positioning accuracy are higher, and the traditional navigation positioning method has a large error, which will cause the robot to move. Without the exact position, the wall cannot be plastered, or the error of plastering the wall is large. A new positioning method is proposed, which is assisted by line lasers and uses image processing-based positioning to perform more accurate positioning on the traditional positioning work. In actual work, filter, edge detection, Hough transform and other operations are performed on the images captured by the camera. Each time the position of the laser line is found, it is compared with the standard value, and the position of the robot is moved or rotated to complete the positioning work. The experimental results show that the actual positioning error is reduced to less than 0.5 mm by this accurate positioning method.

Keywords: indoor plastering robot, navigation, precise positioning, line laser, image processing

Procedia PDF Downloads 125

Authors: Hasliza A. Rahim, Fareq Malek, Nur A. M. Affendi, Azuwa Ali, Norshafinash Saudin, Latifah Mohamed

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This paper presents the experimental investigation of on-body channel fading at 2.45 GHz considering two effects of the user body movement; stationary and mobile. A pair of body-worn antennas was utilized in this measurement campaign. A statistical analysis was performed by comparing the measured on-body path loss to five well-known distributions; lognormal, normal, Nakagami, Weibull and Rayleigh. The results showed that the average path loss of moving arm varied higher than the path loss in sitting position for upper-arm-to-left-chest link, up to 3.5 dB. The analysis also concluded that the Nakagami distribution provided the best fit for most of on-body static link path loss in standing still and sitting position, while the arm movement can be best described by log-normal distribution.

Keywords: on-body channel communications, fading characteristics, statistical model, body movement

Procedia PDF Downloads 328

Authors: H. Ben Khlifa, W. Cheikhrouhou-Koubaa, A. Cheikhrouhou

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The orthorhombic Pr₀.₈Na₀.₂−ₓKₓMnO₃ (x = 0.10 and 0.15) manganites are prepared by using the solid-state reaction at high temperatures. The critical exponents (β, γ, δ) are investigated through various techniques such as modified Arrott plot, Kouvel-Fisher method, and critical isotherm analysis based on the data of the magnetic measurements recorded around the Curie temperature. The critical exponents are derived from the magnetization data using the Kouvel-Fisher method, are found to be β = 0.32(4) and γ = 1.29(2) at TC ~ 123 K for x = 0.10 and β = 0.31(1) and γ = 1.25(2) at TC ~ 133 K for x = 0.15. The critical exponent values obtained for both samples are comparable to the values predicted by the 3D-Ising model and have also been verified by the scaling equation of state. Such results demonstrate the existence of ferromagnetic short-range order in our materials. The magnetic entropy changes of polycrystalline samples with a second-order phase transition are investigated. A large magnetic entropy change deduced from isothermal magnetization curves, is observed in our samples with a peak centered on their respective Curie temperatures (TC). The field dependence of the magnetic entropy changes are analyzed, which shows power-law dependence ΔSmax ≈ a(μ0 H)n at the transition temperature. The values of n obey the Curie Weiss law above the transition temperature. It is shown that for the investigated materials, the magnetic entropy change follows a master curve behavior. The rescaled magnetic entropy change curves for different applied fields collapse onto a single curve for both samples.

Keywords: manganites, critical exponents, magnetization, magnetocaloric, master curve

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Authors: Lise P. Labéjof, Ivna Mororó, Raquel G. Bastos, Maria Isabel G. Severo, Arno H. de Oliveira

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This work presents an alternative mode of intestine mucosa renewal that may allow to better understand the total loss of villi after irradiation. It was tested a morphological method of 3d reconstruction using micrographs of serial sections of rat duodenum. We used hundreds of sections of each specimen of duodenum placed on glass slides and examined under a light microscope. Those containing the detachment, approximately a dozen, were chosen for observation under a transmission electron microscope (TEM). Each of these sections was glued on a block of epon resin and recut into a hundred of 60 nm-thick sections. Ribbons of these ultrathin sections were distributed on a series of copper grids in the same order of appearance than during the process of microstomia. They were then stained by solutions of uranyl and lead salts and observed under a TEM. The sections were pictured and the electron micrographs showing signs of cells detachment were transferred into two softwares, ImageJ to align the cellular structures and Reconstruct to realize the 3d reconstruction. It has been detected epithelial cells that exhibited all signs of programmed cell death and localized at the villus-crypt junction. Their nucleus was irregular in shape with a condensed chromatin in clumps. Their cytoplasm was darker than that of neighboring cells, containing many swollen mitochondria. In some places of the sections, we could see intercellular spaces enlarged by the presence of shrunk cells which displayed a plasma membrane with an irregular shape in thermowell as if the cell interdigitations would distant from each other. The three-dimensional reconstruction of the crypts has allowed observe gradual loss of intercellular contacts of crypt cells in the longitudinal plan of the duodenal mucosa. In the transverse direction, there was a gradual increase of the intercellular space as if these cells moved away from one another. This observation allows assume that the gradual remoteness of the cells at the villus-crypt junction is the beginning of the mucosa detachment. Thus, the shrinking of cells due to apoptosis is the way that they detach from the mucosa and progressively the villi also. These results are in agreement with our initial hypothesis and thus have demonstrated that the villi become detached from the mucosa at the villus-crypt junction by the programmed cell death process. This type of loss of entire villus helps explain the rapid denudation of the intestinal mucosa in case of irradiation.

Keywords: 3dr, transmission electron microscopy, ionizing radiations, rat small intestine, apoptosis

Procedia PDF Downloads 362

Authors: Gizem Kayar, Ramazan Bakir, M. Ilkay Koşar, Ceren U. Gencer, Alperen Ayyildiz

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Anatomy classes are crucial for general education of medical students, whereas learning anatomy is quite challenging and requires memorization of thousands of structures. In traditional teaching methods, learning materials are still based on books, anatomy mannequins, or videos. This results in forgetting many important structures after several years. However, more interactive teaching methods like virtual reality, augmented reality, gamification, and motion sensors are becoming more popular since such methods ease the way we learn and keep the data in mind for longer terms. During our study, we designed a virtual reality based digital head anatomy platform to investigate whether a fully interactive anatomy platform is effective to learn anatomy and to understand the level of teaching and learning optimization. The Head is one of the most complicated human anatomy structures, with thousands of tiny, unique structures. This makes the head anatomy one of the most difficult parts to understand during class sessions. Therefore, we developed a fully interactive digital tool with 3D model marking, quiz structures, 2D/3D puzzle structures, and VR support so as to integrate the power of VR and gamification. The project has been developed in Unity game engine with HTC Vive Cosmos VR headset. The head anatomy 3D model has been selected with full skeletal, muscular, integumentary, head, teeth, lymph, and vein system. The biggest issue during the development was the complexity of our model and the marking of it in the 3D world system. 3D model marking requires to access to each unique structure in the counted subsystems which means hundreds of marking needs to be done. Some parts of our 3D head model were monolithic. This is why we worked on dividing such parts to subparts which is very time-consuming. In order to subdivide monolithic parts, one must use an external modeling tool. However, such tools generally come with high learning curves, and seamless division is not ensured. Second option was to integrate tiny colliders to all unique items for mouse interaction. However, outside colliders which cover inner trigger colliders cause overlapping, and these colliders repel each other. Third option is using raycasting. However, due to its own view-based nature, raycasting has some inherent problems. As the model rotate, view direction changes very frequently, and directional computations become even harder. This is why, finally, we studied on the local coordinate system. By taking the pivot point of the model into consideration (back of the nose), each sub-structure is marked with its own local coordinate with respect to the pivot. After converting the mouse position to the world position and checking its relation with the corresponding structure’s local coordinate, we were able to mark all points correctly. The advantage of this method is its applicability and accuracy for all types of monolithic anatomical structures.

Keywords: anatomy, e-learning, virtual reality, 3D model marking

Procedia PDF Downloads 70

Authors: K. A.Veselova, N. V.Gromova, I. N.Antonova, I. N. Kalakutskii

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There are many diseases and incidents that may result facial defects and deformities: cancer, trauma, burns, congenital anomalies, and autoimmune diseases. In some cases, patient may acquire atypically extensive facial defect, including more than one anatomical region or, by contrast, atypically small defect (e.g. partial auricular defect). The anaplastology gives us opportunity to help patient with facial disfigurement in cases when plastic surgery is contraindicated. Using of implant retention for facial prosthesis is strongly recommended because improves both aesthetic and functional results and makes using of the prosthesis more comfortable. Prostheticly oriented fixture position is extremely important for aesthetic and functional long-term result; however, the optimal site for fixture placement is not clear in cases with atypical configuration of facial defect. The objective of this report is to demonstrate challenges in fixture position determination we have faced with and offer the solution. In this report, four cases of implant-supported facial prosthesis are described. Extra-oral implants with four millimeter length were used in all cases. The decision regarding the quantity of surgical stages was based on anamnesis of disease. Facial prostheses were manufactured according to conventional technique. Clinical and technological difficulties and mistakes are described, and prostheticly oriented approach for determination of fixture position is demonstrated. The case with atypically large combined orbital and nasal defect resulting after arteriovenous malformation is described: the correct positioning of artificial eye was impossible due to wrong position of the fixture (with suprastructure) located in medial aspect of supraorbital rim. The suprastructure was unfixed and this fixture wasn`t used for retention in order to achieve appropriate artificial eye placement and better aesthetic result. In other case with small partial auricular defect (only helix and antihelix were absent) caused by squamoized cell carcinoma T1N0M0 surgical template was used to avoid the difficulties. To achieve the prostheticly oriented fixture position in case of extremely small defect the template was made on preliminary cast using vacuum thermoforming method. Two radiopaque markers were incorporated into template in preferable for fixture placement positions taking into account future prosthesis configuration. The template was put on remaining ear and cone-beam CT was performed to insure, that the amount of bone is enough for implant insertion in preferable position. Before the surgery radiopaque markers were extracted and template was holed for guide drill. Fabrication of implant-retained facial prostheses gives us opportunity to improve aesthetics, retention and patients’ quality of life. But every inaccuracy in planning leads to challenges on surgery and prosthetic stages. Moreover, in cases with atypically small or extended facial defects prostheticly oriented approach for determination of fixture position is strongly required. The approach including surgical template fabrication is effective, easy and cheap way to avoid mistakes and unpredictable result.

Keywords: anaplastology, facial prosthesis, implant-retained facial prosthesis., maxillofacil prosthese

Procedia PDF Downloads 79

Authors: Mohamad Saberi, Arash Sohrabi

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Tuned liquid damper is one the passive structural control ways which has been used since mid-1980 decade for seismic control in civil engineering. This system is made of one or many tanks filled with fluid, mostly water that installed on top of the high raised structure and used to prevent structure vibration. In this article we will show how to make seismic table contain TLD system and analysis the result of using this system in our structure. Results imply that when frequency ratio approaches 1 this system can perform its best in both dissipate energy and increasing structural damping. And also results of these serial experiments are proved compatible with Hunzer linear theory behaviour.

Keywords: TLD, seismic table, structural system, Hunzer linear behaviour

Procedia PDF Downloads 357

Authors: Abhishek Jha, Manoj Kumar

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This paper proposes a new type of two wheels differential type odometry to estimate the next position and orientation of mobile robots. The proposed odometry is composed for two independent wheels with respective encoders. The two wheels rotate independently, and the change is determined by the difference in the velocity of the two wheels. Angular velocities of the two wheels are measured by rotary encoders. A mathematical model is proposed for the mobile robots to precisely move towards the goal. Using measured values of the two encoders, the current displacement vector of a mobile robot is calculated by kinematics of the mathematical model. Using the displacement vector, the next position and orientation of the mobile robot are estimated by proposed odometry. Result of simulator experiment by the developed odometry is shown.

Keywords: mobile robot, odometry, unicycle, differential type, encoders, infrared range sensors, kinematic model

Procedia PDF Downloads 422

Authors: Hashim Ali, Sheheryar Khan

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Security for applications is always been a keen issue of concern. In general, security is to allow access of grant to legal user or to deny non-authorized access to the system. Shoulder surfing is an observation technique to hack an account or to enter into a system. When a malicious observer is capturing or recording the fingers of a user while he is entering sensitive inputs (PIN, Passwords etc.) and may be able to observe user’s password credential. It is very rigorous for a novice user to prevent himself from shoulder surfing or unaided observer in a public place while accessing his account. In order to secure the user account, there are five factors of authentication; they are: “(i) something you have, (ii) something you are, (iii) something you know, (iv) somebody you know, (v) something you process”. A technique has been developed of fifth-factor authentication “something you process” to provide novel approach to the user. In this paper, we have applied position based operational code authentication in such a way to more easy and user friendly to the user.

Keywords: shoulder surfing, malicious observer, sensitive inputs, authentication

Procedia PDF Downloads 246

Authors: Norazharuddin Shah Abdullah, Harshita Aini Haroon, Norazian Mohmad Azman, Erlane K. Ghani, Ismie Roha Mohamed Jais, Kamaruzzaman Muhammad, Azleen Ilias

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This study examines the factors that influence academics' decisions to accept or decline leadership roles in Malaysian universities. A questionnaire survey was distributed to a total of 1771 academics from public and private institutions in Malaysia. This study shows that the majority of academics in universities, regardless of whether they are public or private, have a reluctance to take on administrative roles. In particular, this study shows that female academics in public universities have no ambition for administrative roles, while female academics in private universities show a strong enthusiasm for taking up administrative positions. In terms of age, academics of all age groups made comparable choices, but academics who are under 30 years old have a greater propensity to aspire to an administrative position. Associate professors at private universities also opt for an administrative position. The factors that influence academics' decisions to accept or decline an administrative position are categorised into five categories: career development, skills and experience, preferences, perceptions, and organization. The findings of this study suggest that the increasing number of academics not seeking institutional leadership positions is a concern, as universities need a sufficient pool of potential successors to effectively fulfil the purpose and vision of the university. This study suggests the implementation of awareness and training initiatives to inspire academics, especially young academics, to take up leadership roles within the institutions.

Keywords: academics, institutional leadership, leadership, universities, Malaysia

Procedia PDF Downloads 28

Authors: Mohamad Saberi, Arash Sohrabi

Abstract:

Tuned liquid damper is one the passive structural control ways which has been used since mid-1980 decade for seismic control in civil engineering. This system is made of one or many tanks filled with fluid, mostly water that installed on top of the high raised structure and used to prevent structure vibration. In this article, we will show how to make seismic table contain TLD system and analysis the result of using this system in our structure. Results imply that when frequency ratio approaches 1 this system can perform its best in both dissipate energy and increasing structural damping. And also results of these serial experiments are proved compatible with Hunzer linear theory behaviour.

Keywords: TLD, seismic table, structural system, Hunzer linear behaviour

Procedia PDF Downloads 310

Authors: Rasaq Bello, Grace Akintola Sunday, Yemi Sikiru Onifade

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Groundwater is required for the continuity of life and sustainability of the ecosystem. Hence, this research was purposed to assess groundwater quality for domestic use in Kaltungo Local Government Area, Gombe State. The work was also aimed at determining the thickness and resistivity of the topsoil, areas suitable for borehole construction, quality and potentials of groundwater in the study area. The study area extends from latitude N10015’38” - E11008’01” and longitude N10019’29” - E11013’05”. The data was acquired using the Vertical Electrical Sounding (VES) method and processed using IP12win software. Twenty (20) Vertical Electrical Soundings were carried out with a maximum current electrode separation (AB) of 150m. The VES curves generated from the data reveal that all the VES points have five to six subsurface layers. The first layer has a resistivity value of 7.5 to 364.1 Ωm and a thickness ranging from 0.8 to 7.4m, and the second layer has a resistivity value of 1.8 to 600.3 Ωm thickness ranging from 2.6 to 31.4m, the third layer has resistivity value of 23.3 to 564.4 Ωm thickness ranging from 10.3 to 77.8m, the fourth layer has resistivity value of 19.7 to 640.2 Ωm thickness ranging from 8.2m to 120.0m, the fifth layer has resistivity value of 27 to 234 Ωm thickness ranging from 8.2 to 53.7m and the six-layer is the layer that extended beyond the probing depth. The VES curves generated from the data revealed KQHA curve type for VES 1, HKQQ curve for VES 4, HKQ curve for VES 5, KHA curve for VES 11, QQHK curve for VES 12, HAA curve for VES 6 and VES 19, HAKH curve for VES 7, VES 8, VES 10 and VES 18, HKH curve for VES 2, VES 3, VES 9, VES 13, VES 14, VES 15, VES 16, VES 17 and VES 20. Values of the Coefficient of Anisotropy, Reflection Coefficient, and Resistivity Contrast obtained from the Dar-Zarrouk parameters indicated good water prospects for all the VES points in this study, with VES points 4, 9 and 18 having the highest prospects for groundwater exploration.

Keywords: formation parameters, groundwater, resistivity, resistivity contrast, vertical electrical sounding

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Authors: A. Majczak, G. Baranski, K. Pietrykowski

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Due to the growing popularity of light aircraft, it has become necessary to develop aircraft engines for this type of construction. One of engine system, designed to increase efficiency and reduce weight, is the engine with opposed pistons. In such an engine, the combustion chamber is formed by two pistons moving in one cylinder. Therefore, this type of engines run in a two-stroke cycle, so they have many advantages such as high power and torque, high efficiency, or a favorable power-to-weight ratio. Tests of one of the available aircraft engines with opposing piston system fueled with diesel oil were carried out on an engine dynamometer equipped with an eddy current brake and the necessary measuring and testing equipment. In order to get to know the basic parameters of the engine, the tests were carried out under partial load conditions for the following torque values: 40, 60, 80, 100 Nm. The rotational speed was changed from 1600 to 2500 rpm. Measurements were also taken for designated points of propeller characteristics. During the tests, the engine torque, engine power, fuel consumption, intake manifold pressure, and oil pressure were recorded. On the basis of the measurements carried out for particular loads, the power curve, hourly and specific fuel consumption curves were determined. Characteristics of charge pressure as a function of rotational speed as well as power, torque, hourly and specific fuel consumption curves for propeller characteristics were also prepared. The obtained characteristics make it possible to select the optimal points of engine operation.

Keywords: aircraft, diesel, engine testing, opposed piston

Procedia PDF Downloads 132

Authors: Nafiseh Ebrahimi, Amir Jafari

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The study of humanoid character is of great interest to researchers in the field of robotics and biomechanics. One might want to know the forces and torques required to move a limb from an initial position to the desired destination position. Inverse dynamics is a helpful method to compute the force and torques for an articulated body limb. It enables us to know the joint torques required to rotate a link between two positions. Our goal in this study was to control a human-like articulated manipulator for a specific task of path tracking. For this purpose, the human arm was modeled with a three-link planar manipulator activated by Hill muscle model. Applying a proportional controller, values of force and torques applied to the joints were calculated by inverse dynamics, and then joints and muscle forces trajectories were computed and presented. To be more accurate to say, the kinematics of the muscle-joint space was formulated by which we defined the relationship between the muscle lengths and the geometry of the links and joints. Secondary, the kinematic of the links was introduced to calculate the position of the end-effector in terms of geometry. Then, we considered the modeling of Hill muscle dynamics, and after calculation of joint torques, finally, we applied them to the dynamics of the three-link manipulator obtained from the inverse dynamics to calculate the joint states, find and control the location of manipulator’s end-effector. The results show that the human arm model was successfully controlled to take the designated path of an ellipse precisely.

Keywords: arm manipulator, hill muscle model, six-muscle model, three-link lodel

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Authors: Nisha Deopa, A. S. Rao

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Lithium Lead Alumino Borate (LiPbAlB) glasses doped with different Dy3+ ions concentration were synthesized to investigate their viability in solid state lighting (SSL) technology by melt quenching techniques. From the absorption spectra, bonding parameters (ð) were investigated to study the nature of bonding between Dy3+ ions and its surrounding ligands. Judd-Ofelt (J-O) intensity parameters (Ω = 2, 4, 6), estimated from the experimental oscillator strengths (fex) of the absorption spectral features were used to evaluate the radiative parameters of different transition levels. From the decay curves, experimental lifetime (τex) were measured and coupled with the radiative lifetime to evaluate the quantum efficiency of the as-prepared glasses. As Dy3+ ions concentration increases, decay profile changes from exponential to non-exponential through energy transfer mechanism (ETM) in turn decreasing experimental lifetime. In order to investigate the nature of ETM, non-exponential decay curves were fitted to Inkuti–Hirayama (I-H) model which further confirms dipole-dipole interaction. Among all the emission transition, 4F9/2  6H15/2 transition (483 nm) is best suitable for lasing potentialities. By exciting titled glasses in n-UV to blue regions, CIE chromaticity coordinates and Correlated Color Temperature (CCT) were calculated to understand their capability in cool white light generation. From the evaluated radiative parameters, CIE co-ordinates, quantum efficiency and confocal images it was observed that glass B (0.5 mol%) is a potential candidate for developing w-LEDs and lasers.

Keywords: energy transfer, glasses, J-O parameters, photoluminescence

Procedia PDF Downloads 190

Authors: Sumi Manjipparambil Surendran, Subrata Majumdar

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Aim: The aim of the study is to find out if low PAPP-A (Pregnancy-Associated Plasma Protein A) levels in the first trimester are associated with adverse obstetric outcome. Methods: A retrospective study was carried out on 114 singleton pregnancies having undergone combined test screening. Results: There is statistically significant increased incidence of low birth weight infants in the low PAPP-A group. However, significant association was not found in the incidence of pre-eclampsia, miscarriage, and placental abruption. Conclusion: Low PAPP-A in the first trimester is associated with fetal growth restriction. Recommendation: Women with low PAPP-A levels in first trimester pregnancy screening require consultant-led care and serial growth scans.

Keywords: pregnancy, pregnancy-associated plasma protein A, PAPP-A, fetal growth restriction, trimester

Procedia PDF Downloads 119

Authors: Ameer A. Jebur, William Atherton, Rafid M. Alkhaddar, Edward Loffill

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Understanding the behaviour of the piles under the action of the independent lateral loads and the precise prediction of the capacity of piles subjected to different lateral loads are vital topics in foundation design and analysis. Moreover, the laterally loaded behaviour of deep foundations penetrated in cohesive and non-cohesive soils is basically analysed by the Winkler Model (beam on elastic foundation), in which the interaction between the pile embedded depth and contacted soil is simulated by nonlinear p–y curves. The presence of many approaches to interpret the behaviour of soil-pile interaction has resulted in numerous outputs and indicates that no general approach has yet been adopted. The current study presents the result of numerical modelling of the behaviour of steel tubular piles (25.4mm) outside diameter with various embedment depth-to-diameter ratios (L/d) embedded in a sand calibrated chamber of known relative density. The study revealed that the shear strength parameters of the sand specimens and the (L/d) ratios are the most significant factor influencing the response of the pile and its capacity while taking into consideration the complex interaction between the pile and soil. Good agreement has been achieved when comparing the application of this modelling approach with experimental physical modelling carried out by another researcher.

Keywords: deep foundations, slenderness ratio, soil-pile interaction, winkler model (beam on elastic foundation), non-cohesive soil

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Authors: Magdalena Kowalska, Weronika Rupik

Abstract:

The pancreas is an important organ present in all vertebrate species. It contains two different tissues, exocrine and endocrine, that act as two glands in one. The development and differentiation of the pancreas in reptiles is poorly known in comparison to other vertebrates. Therefore, the aim of this study was to investigate the particular steps concerning the differentiation of the pancreas in the grass snake (Natrix natrix) embryos. For this, histological methods (including hematoxylin and eosin, and Heidenhain's AZAN staining), transmission electron microscopy and three-dimensional (3D) reconstructions from serial paraffin sections were used. The results of this study indicated that the first step of pancreas development in Natrix was the connection of the two pancreatic buds: dorsal and ventral one. Then, duct walls in both buds started to be remodeled from the multilayered to single-layered epithelium. This remodeling started in the dorsal bud and was simultaneously with the differentiation of the duct lumens which occurred by the cavition. During this process, the cells that had no contact with the mesenchyme underwent cell death named anoikis. These findings indicated that the walls of ducts in the embryonic pancreas of the grass snake were initially formed by the abundant principal and single endocrine cells. Later the basal and goblet cells differentiated. Among the endocrine cells, as the first the B and A cells differentiated, then the D and PP cells. The next step of the pancreatic development was the withdrawing of the endocrine cells from the duct walls to form the pancreatic islets. The endocrine cells and islets were found only in the dorsal part of the pancreas in Natrix embryos what is different than in other vertebrate species. The islets were formed mainly by the A cells. Simultaneously, with the differentiation of the endocrine pancreas, the acinar tissue started to differentiate. The source of the acinar cells were pancreatic ducts similar as in other vertebrates. The acini formation began at the proximal part of the pancreas and went towards the caudal direction. Differentiating pancreatic ducts developed into the branched system that can be divided into extralobular, intralobular, and intercalated ducts, similarly as in other vertebrate species. However, the pattern of branching was different. In conclusions, particular steps of the pancreas differentiation in the grass snake were different than in other vertebrates. It can be supposed that these differences are related to the specific topography of the snake’s internal organs and their taxonomy position. All specimens used in the study were captured according to the Polish regulations concerning the protection of wild species. Permission was granted by the Local Ethics Commission in Katowice (41/2010; 87/2015) and the Regional Directorate for Environmental Protection in Katowice (WPN.6401.257.2015.DC).

Keywords: embryogenesis, organogenesis, pancreas, Squamata

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Authors: Houxiang Zhu, Chun Liang

Abstract:

The CRISPR-Cpf1 system has been successfully applied in genome editing. However, target efficiency of the CRISPR-Cpf1 system varies among different gRNA sequences. The published CRISPR-Cpf1 gRNA data was reanalyzed. Many sequences and structural features of gRNAs (e.g., the position-specific nucleotide composition, position-nonspecific nucleotide composition, GC content, minimum free energy, and melting temperature) correlated with target efficiency were found. Using machine learning technology, a support vector machine (SVM) model was created to predict target efficiency for any given gRNAs. The first web service application, CRISPR-DT (CRISPR DNA Targeting), has been developed to help users design optimal gRNAs for the CRISPR-Cpf1 system by considering both target efficiency and specificity. CRISPR-DT will empower researchers in genome editing.

Keywords: CRISPR-Cpf1, genome editing, target efficiency, target specificity

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Authors: Fouad Inel, Lakhdar Khochemane

Abstract:

This article presents a comparative response specification performance between two controllers of three and four cable based robots for various applications. The main objective of this work is: the first is to use the direct and inverse geometric model to study and simulate the end effector position of the robot with three and four cables. A graphical user interface has been implemented in order to visualizing the position of the robot. Secondly, we present the determination of static and dynamic tensions and lengths of cables required to flow different trajectories. At the end, we study the response of our systems in closed loop with a Proportional-IntegratedDerivative (PID) and Proportional-Integrated (PD) controllers then this last are compared the results of the same examples using MATLAB/Simulink; we found that the PID method gives the better performance, such as rapidly speed response, settling time, compared to PD controller.

Keywords: dynamic modeling, geometric modeling, graphical user interface, open loop, parallel cable-based robots, PID/PD controllers

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Authors: Elly Usman, S. Dante, Diah Purnamasari

Abstract:

Type 2 diabetes mellitus ( T2DM ) is a syndrome characterized by a state of increased blood sugar levels due to chronic disorders of insulin secretion by pancreatic beta cells and insulin action or a combination of both. The organic cation transporter 1, encoded by the SLC22A1 gene, responsible for the uptake of the antihyperglycemic drug, metformin, in the hepatocyte. We assessed whether a genetic variation in the SLC22A1 gene was associated with the glucose - lowering effect of metformin. Method case study research design. Samples are children with type 2 diabetes mellitus who meet the inclusion criteria. The results proportions SLC22A1 gene polymorphisms in children with diabetes mellitus type 2 amounted to 52.04 % at position 400T/C, there is one heterozygous and one at position 595T/C Conclusion The presence of SLC22A1 gene polymorphisms in children with diabetes mellitus type 2.

Keywords: diabetes Mellitus type 2, metformin, organic cation transporter 1, pharmacogenomics

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Authors: Felix Eyben, Simon Schaffrath, Markus Feldmann

Abstract:

A building should maximize the potential for use through its design. Therefore, flexible use is always important when designing a steel structure. To create flexibility, steel beams with web openings are increasingly used, because these offer the advantage that cables, pipes and other technical equipment can easily be routed through without detours, allowing for more space-saving and aesthetically pleasing construction. This can also significantly reduce the height of ceiling systems. Until now, beams with web openings were not explicitly considered in the European standard. However, this is to be done with the new EN 1993-1-13, in which design rules for different opening forms are defined. In order to further develop the design concepts, beams with web openings under bending are therefore to be investigated in terms of damage mechanics as part of a German national research project aiming to optimize the verifications for steel structures based on a wider database and a validated damage prediction. For this purpose, first, fundamental factors influencing the load-bearing behavior of girders with web openings under bending load were investigated numerically without taking material damage into account. Various parameter studies were carried out for this purpose. For example, the factors under study were the opening shape, size and position as well as structural aspects as the span length, arrangement of stiffeners and loading situation. The load-bearing behavior is evaluated using resulting load-deformation curves. These results are compared with the design rules and critically analyzed. Experimental tests are also planned based on these results. Moreover, the implementation of damage mechanics in the form of the modified Bai-Wierzbicki model was examined. After the experimental tests will have been carried out, the numerical models are validated and further influencing factors will be investigated on the basis of parametric studies.

Keywords: damage mechanics, finite element, steel structures, web openings

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Authors: Sophia Fry, Mahir Irtiza, Alexa Hoffman, Yousef Sardahi

Abstract:

This study presents an intelligent control algorithm for a flexible robotic arm. Fuzzy control is used to control the motion of the arm to maintain the arm tip at the desired position while reducing vibration and increasing the system speed of response. The Fuzzy controller (FC) is based on adding the tip angular position to the arm deflection angle and using their sum as a feedback signal to the control algorithm. This reduces the complexity of the FC in terms of the input variables, number of membership functions, fuzzy rules, and control structure. Also, the design of the fuzzy controller is model-free and uses only our knowledge about the system. To show the efficacy of the FC, the control algorithm is implemented on the flexible joint manipulator (FJM) developed by Quanser. The results show that the proposed control method is effective in terms of response time, overshoot, and vibration amplitude.

Keywords: fuzzy logic control, model-free control, flexible joint manipulators, nonlinear control

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Authors: Tawanda Mushiri, Charles Mbohwa

Abstract:

When an external load is applied to one of its ends, a pipe’s bends cross section tends to deform significantly both in and out of its end plane. This shell type behaviour characteristic of pipe bends and mainly due to their curves geometry accounts for their greater flexibility. This added flexibility is also accompanied by stressed and strains that are much higher than those present in a straight pipe. The primary goal of this research is to study the elastic-plastic behaviour of pipe bends under out of plane moment loading. It is also required to study the effects of changing the value of the pipe bend factor and the value of the internal pressure on that behaviour and to determine the value of the limit moments in each case. The results of these analyses are presented in the form of load deflection plots for each load case belonging to each model. From the load deflection curves, the limit moments of each case are obtained. The limit loads are then compared to those computed using some of the analytical and empirical equation available in the literature. The effects of modelling parameters are also studied. The results obtained from small displacement and large displacement analyses are compared and the effects of using a strain hardened material model are also investigated. To better understand the behaviour of pipe elbows under out of plane bending and internal pressure, it was deemed important to know how the cross section deforms and to study the distribution of stresses that cause it to deform in a particular manner. An elbow with pipe bend factor h=0.1 to h=1 is considered and the results of the detailed analysis are thereof examined.

Keywords: elasto-plastic, finite element analysis, pipe bends, simulation

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Authors: Xuan Sun, Mingbo Tong

Abstract:

To understand the factors which affect impact damage on composite structures, particularly the effects of impact position and ribs. In this paper, a finite element model (FEM) of low-velocity impact damage on the composite structure was established via the nonlinear finite element method, combined with the user-defined materials subroutine (VUMAT) of the ABAQUS software. The structural elements chosen for the investigation comprised a series of stiffened composite panels, representative of real aircraft structure. By impacting the panels at different positions relative to the ribs, the effect of relative position of ribs was found out. Then the simulation results and the experiments data were compared. Finally, the factors which affect impact damage on the structures were discussed. The paper was helpful for the design of stiffened composite structures.

Keywords: stiffened, low-velocity impact, Abaqus, impact energy

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Authors: Hao-Yuan Tseng, Chuan-Yang Chang, Ying-Hui Chen, Sheng-Che Chen, Chih-Han Chang

Abstract:

Orthodontic tooth treatment has demonstrated a high success rate in clinical studies. It has been agreed upon that orthodontic tooth movement is based on the ability of surrounding bone and periodontal ligament (PDL) to react to a mechanical stimulus with remodeling processes. However, the mechanism of the tooth movement is still unclear. Recent studies focus on the simple principle compression-tension theory while rare studies directly measure tooth movement. Therefore, tracking tooth movement information during orthodontic treatment is very important in clinical practice. The aim of this study is to investigate the mechanism responses of the tooth movement during the orthodontic treatments. A stereovision system applied to track the tooth movement of the patient with the stamp brackets. The system was established by two cameras with their relative position calibrate. And the orthodontic force measured by 3D printing model with the six-axis load cell to determine the initial force application. The result shows that the stereovision system accuracy revealed the measurement presents a maximum error less than 2%. For the study on patient tracking, the incisor moved about 0.9 mm during 60 days tracking, and half of movement occurred in the first few hours. After removing the orthodontic force in 100 hours, the distance between before and after position incisor tooth decrease 0.5 mm consisted with the release of the phenomenon. Using the stereovision system can accurately locate the three-dimensional position of the teeth and superposition of 3D coordinate system for all the data to integrate the complex tooth movement.

Keywords: orthodontic treatment, tooth movement, stereovision system, long-term tracking

Procedia PDF Downloads 398