DEVELOPMENT OF A SOFT PNEUMATIC ACTUATOR FOR MODULAR ROBOTIC MECHANISMS

Soft robotics is a widely and rapidly growing field of research today. Soft pneumatic actuators, as a fundamental element in soft robotics, have gained huge popularity and are being employed for the development of soft robots. During the last decade, a variety of hyper-elastic robotic systems have been realized. As the name suggests, such robots are made up of soft materials, and do not have any underlying rigid mechanical structure. These robots are actuated employing various methods like pneumatic, electroactive, jamming etc. Generally, in order to achieve a desired mechanical response to produce required actuation or manipulation, two or more materials having different stiffness are utilized to develop a soft robot. However, this method introduces complications in the fabrication process as well as in further design flexibility and modifications. The current work presents a design scheme of a soft robotic actuator adapting an easier fabrication approach, which is economical and environment friendly as well. The purpose is the realization of a soft pneumatic actuator having functional ability to produce effective actuation, and which is further employable to develop modular and scalable mechanisms. That infers to scrutinize the profile and orientation of the internal actuation cavity and the outer shape of viii the actuator. Utilization of a single material for this actuator has been considered to make this design scheme convenient. A commercial silicone rubber was selected which served for an economical process both in terms of the cost as well as its accommodating fabrication process through molding. In order to obtain the material behavior, \u2018Ansys Workbench 17.1 R \u2019 has been used. Cubic outline for the actuator aided towards the realization of a body shape which can easily be engaged for the development of modular mechanisms employing multiple units. This outer body shape further facilitates to achieve the stability and portability of the actuator. The soft actuator has been named \u2018Soft Cubic Module\u2019 based on its external cubic shape. For the internal actuation cavity design, various shapes, such as spherical, elliptical and cylindrical, were examined considering their different sizes and orientations within the cubic module. These internal cavities were simulated in order to achieve single degree of freedom actuation. That means, only one face of the cube is principally required to produce effective deformation. \u2018Creo Perametric 3.0 M 130\u2019 has been used to design the model and to evaluate the performance of actuation cavities in terms of effective deformation and the resulting von-mises stress. Out of the simulated profiles, cylindrical cavity with desired outcomes has been further considered to design the soft actuator. \u2018Ansys Workbench 17.1 R \u2019 environment was further used to assess the performance of cylindrical actuation cavity. Evaluation in two different simulation environments helped to validate the initially achieved results. The developed soft cubic actuator was then employed to develop different mechanisms in a single unit configuration as well as multi-unit robotic system developments. This design scheme is considered as the first tool to investigate its capacity to perform certain given tasks in various configurations. Alongside its application as a single unit gripper and a two unit bio-mimetic crawling mechanism, this soft actuator has been employed to realize a four degree ix of freedom robotic mechanism. The formation of this primitive soft robotic four axis mechanism is being further considered to develop an equivalent mechanism similar to the well known Stewart platform, with advantages of compactness, simpler kinematics design, easier control, and lesser cost. Overall, the accomplished results indicate that the design scheme of Soft Cubic Module is helpful in realizing a simple and cost-effective soft pneumatic actuator which is modular and scalable. Another favourable point of this scheme is the use of a single material with convenient fabrication and handling

Outcome of shaft fractures among children treated with elastic stable intramedullary nailing

Background: Long bone fractures are frequent occurrence among children and considered a frequent pediatric orthopedic injury requiring hospitalization. Authors aimed to retrospectively analyze the outcome of fixation of long bone fractures with elastic stable intramedullary nailing (ESIN) among children and adolescents.Methods: From 2010 to 2018, ESIN was performed on 128 children aged 2 to 17 years having single shaft fractures of long bones. The data related to associated injuries, postoperative complications, postoperative treatment, till bony union or removal of rods, mal-union, functional deficit, need for secondary surgical intervention and subjective complaints at follow-up originated from postoperative clinical and radiological consultations carried out regularly. The primary end points were time of complete radiological union or removal of rods.Results: The mean age at the time of accident was 9.5 years. There were 37 (28.9%) femoral fractures, 16 (12.5%) of the lower leg, 51 (39.8%) fractures of radius/ulna and 24 (18.8%) of the humerus. In 2 (2.3%) children, reoperation was necessary due to prominent ends of elastic rods and 6 (4.7%) had early removal of rods due to same reasons. End point of the study, removal of rods noted in 126 (82.8%), radiological evidence of union in 7 (5.5%) and 15 (11.7%) cases were lost at follow-up.Conclusions: ESIN fixation of diaphyseal fractures in children and adolescents is safe. ESIN was found to be minimally invasive method, noted to produce excellent functional as well as cosmetic outcomes

Attitudes Towards Women’s Rights to Inheritance in District Lakki Marwat, Pakistan

This paper analyses the effects of various economic, demographic and social factors like marriage practices, education and awareness on the beliefs and attitudes regarding women’s rights to inheritance, ownership and management of property in Pakistan. Based on a random sample of 507 families from district Lakki Marwat, a backward northern district of Pakistan, the study finds that education level of respondents, including religious education, awareness of law and formal sources of information regarding women’s rights are the main factors shaping respondents’ perceptions about women’s right to inheritance, ownership and management of property. The other factors like economic status, family demography and marriage practices appear relatively less important

State estimation technique for a planetary robotic rover

Given the long traverse times and severe environmental constraints on a planet like Mars, the only option feasible now is to observe and explore the planet through more sophisticated planetary rovers. To achieve increasingly ambitious mission objectives under such extreme conditions, the rovers must have autonomy. Increased autonomy, obviously, relies on the quality of estimates of rover's state i.e. its position and orientation relative to some starting frame of reference. This research presents a state estimation approach based on Extended Kalman Filter (EKF) to fuse distance from odometry and attitude from an Inertial Measurement Unit (IMU), thus mitigating the errors generated by the use of either system alone. To simulate a Sun-sensor based approach for absolute corrections, a magnetic compass was used to give absolute heading updates. The technique was implemented on MotherBot, a custom-designed skid steered rover. Experimental results validate the application of the presented estimation strategy. It showed an error range within 3% of the distance travelled as compared to about 8% error obtained from direct fusion

2-(2-Methyl­anilino)-N′-(propan-2-yl­idene)acetohydrazide

The conformation of the title compound, C12H17N3O, is consolidated by an intra­molecular N—H⋯O hydrogen bond, generating an S(5) ring. In the crystal, inversion dimers linked by pairs of N—H⋯O inter­actions occur, resulting in R 2 2(8) ring motifs

Parametric Study of Fire Performance of Concrete Filled Hollow Steel Section Columns with Circular and Square Cross-Section

Concrete filled hollow steel section column have been widely accepted by structural engineers and designers for high rise construction due to the benefits of combining steel and concrete. The advantages of concrete filled hollow steel section column include higher strength, ductility, energy absorption capacity, and good structural fire resistance. In this paper, comparison on the fire performance between circular and square concrete filled hollow steel section column is established. A threedimensional finite element package, ABAQUS, was used to develop the numerical model to study the temperature development, critical temperature, and fire resistance time of the selected composite columns. Based on the analysis and comparison of typical parameters, the effect of equal cross-sectional size for both steel and concrete, concrete types, and thickness of external protection on temperature distribution and structural fire behaviour of the columns are discussed. The result showed that concrete filled hollow steel section column with circular cross-section generally has higher fire resistance than the square section

Robotics for nuclear power plants - Challenges and future perspectives

Use of robotics and computerized tools in Nuclear Power Plants (NPPs) has been identified as a highly recommended practice by IAEA. The key rationale of robotics application has always been to avoid human exposure to hazardous environments and tasks ranging from scrutiny and general maintenance to decontamination and post accidental activities. To execute these activities, robots need to incorporate artificial intelligence, improved sensors capability, enhanced data fusion and compliant human like leg and hand structures for efficient motions. Next generation robotic systems in NPPs are expected to work in full autonomous mode in contrast to the current semi-autonomous scenarios. Far future systems could deploy humanoid robots as well. This paper presents state-of-theart of robotics developed for NPPs, associated challenges and finally comments on future directions

Experimental investigation of end-plate connection with cruciform column section

This paper presents an experimental investigation on typical end-plate connection with reduced beam-to-end plate welding, connected to cruciform column (CCUB) section. The study aims to reduce the cost of fabrication and materials. Two tests were conducted to study the behavior of the proposed connections and evaluate the failure modes, moment resistance, initial stiffness and rotational capacity of the connections. The experimental results indicated that the failure mechanisms for the tested specimens begin with the end-plate yielding followed by bolt slippage that was limited to the tension region of the joint due to the tension forces exerted through the top bolt rows. The experimental results will then be used to validate the theoretical model for the T-stub idealization of the tension zone

Time-dependent physicochemical characteristics of Malaysian residual soil stabilized with magnesium chloride solution

The effects of non-traditional additives on the geotechnical properties of tropical soils have been the subject of investigation in recent years. This study investigates the strength development and micro-structural characteristics of tropical residual soil stabilized with magnesium chloride (MgCl2) solution. Unconfined compression strength (UCS) and standard direct shear tests were used to assess the strength and shear properties of the stabilized soil. In addition, the micro-structural characteristics of untreated and stabilized soil were discussed using various spectroscopic and microscopic techniques such as X-ray diffractometry (XRD), energy-dispersive X-ray spectrometry (EDAX), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR) and Brunauer, Emmett and Teller (BET) surface area analysis. From the engineering point of view, the results indicated that the strength of MgCl2-stabilized soil improved noticeably. The degree of improvement was approximately two times stronger than natural soil after a 7-day curing period. The results also concluded the use of 5 % of MgCl2 by dry weight of soil as the optimum amount for stabilization of the selected soil. In addition, the micro-structural study revealed that the stabilization process modified the porous network of the soil. The pores of the soils had been filled by the newly formed crystalline compounds known as magnesium aluminate hydrate (M-A-H).Ministry of Education Malaysia under the Fundamental Research Grant (FRGS) (R.J130000.7822.4F658); Universiti Teknologi Malaysia (UTM); Construction Research Centre UT

Diagnostic Measures in Childhood Tuberculosis: A Short Review

The trends of incidence, morbidity and mortality of tuberculosis in children have always remained unclear because of lack of a definitive diagnostic tool in mostly cases. The diagnosis of tuberculosis in children remains a major challenge as it is seldom confirmed and is mostly based on clinical signs, symptoms and special investigations e. g. TST, chest X-ray and sputum smear microscopy. Sputum smear microscopy is positive in less than 10-15% of children with TB and culture yields are nearly about 30-40%. In low burden countries, the triad of (a) known contact with an infectious source case, (b) a positive tuberculin skin test and (c) a suggestive CXR is usually used to establish a diagnosis of childhood TB. The research on childhood tuberculosis is often neglected due to technical difficulties like slow growth in culture, the difficulty of obtaining specimens and the diverse and relatively nonspecific clinical presentation of tuberculosis in this age group. The complexity in making an exact diagnosis of tuberculosis in children have led to the development of several diagnostic approaches like point scoring systems, diagnostic classifications and diagnostic algorithms. The aim of this study was to review and analyse the different diagnostic approaches to childhood tuberculosis. In this paper, the mostly used techniques like culture methods as well as the non-culture methods including serology, biochemistry and polymerase chain reaction and DNA fingerprinting for the diagnosis of tuberculosis will be discussed. Keywords: Diagnostic measures, Childhood, Tuberculosi