Maximum Torque Estimation Technique Of Three Link System For Sit To Stand Motion

In Humanoid robotics field,capability to perform any task that imitates human movement has been the major research focus.Sit to stand (STS) is a very challenging motion for any humanoid robotic system.In the field of rehabilitation,it is difficult for the physiotherapist technician to readjust prosthetic leg to fit all the patient without proper knowledge and not all of them has the basic knowledge involving robotic system.Thus from several model of STS including telescopic inverted pendulum,single-link,two-link and three-link (3L),we choose to emphasize more on 3L since it is having a similar segment with human body and it fit most of the current prosthetic leg in rehabilitation centre.Current studies involving torque analysis was using a dynamic model,which is complicated and requires high computational resource to compute.Hence,the purpose of this thesis is to study the effect of mass and length’s link changes to each joint torque and much simpler equation to estimate the torque needed in short time is proposed.Simulation model were run and torque information were collected.In order to validate the equation, experiments were carried out with three-link model.Having an error with ± 0.1% proof that the results shows that there is a possibility to estimate maximum torque needed by each link with equation derive from both simulation and experiment

Antibacterial Activity of Methanol Extract of Sargassum polycystum on Escherichia coli and Staphylococcus aureus

Macroalgae is a commodity that is used as food, medicine, fertilizer and other materials in industries. Macroalgae in the medical world have the potential to be anticancer, antiviral, antifungal and antibacterial. One type of macroalgae that has the potential as an antibacterial source is Sargassum polycystum. This study aims to analyze the ability of the methanol extract of S. polycystum to inhibit the growth of bacteria (Escherichia coli and Staphylococcus aureus) and analyze the potential compounds contained in the methanol extract of S. polycystum. This research is an experimental study using a completely randomized design. Extraction method by maceration. The test concentrations used were 20%, 40%, 60%, 80%, positive and negative control. While the test method uses a good diffusion method. Data were analyzed using description and SPSS application. The results showed that the methanol extract of S. polycystum had better inhibition against S. aureus growth than E. coli. The methanol extract concentration of S. polycystum, which had the best inhibition against S. aureus and E. coli was 80%. Metabolites content on S. polycystum extract is Tetradecanoic Acid, Loliolide; Hexadecanoid Acid, Methyl Ester, 9-Hexadecanoid Acid, Hexadecenoic Acid, 8-Octadecanoic, Methyl Ester, 5,8,11,14-Eicosatetraenoic Acid and Ethyl Ester

Cone Penetration Testing For Field Density Prediction

This paper summarizes an experimental program for developing a pilot procedure to check and predict field densities of compacted soils using static cone penetration tests. Three sandy soils were tested. The testing program included both laboratory and field tests. On the basis of laboratory tests, density prediction curves were developed while field results were used to find a correlation to predict densities on the basis of measured penetration resistances. The results are rather encouraging and promising. It is anticipated that the presented methodology would be very effective for compaction quality control in large areas of sandy soils because it is fast, simple and causes minimum disturbance to the compacted soil

The effect of voiding position on uroflowmetry findings of patientswith Benign Prostatic Obstruction(BPO) in urology clinic HTAA

Introduction: Changes in voiding positionmay have signi ficant impact on micturitiondue to factors such as changes in pressureof abdominal muscles and viscera, andrelaxation of pelvic floor muscles in differ-ent voiding positions. Few studies in the lit-erature have addressed the impact ofvoiding position on uroflowmetric results,however, the results were inconclusive.Objectives: To investigate the uroflowme-try findings of three different voiding posi-tions in BPO patients attending theUrology Clinic, HTAA.Materials and Methods: Cross-sectionalobservational study of BPO patientsattending the Urology Clinic HTAA fromMarch 2015 to December 2015.Uroflowmetry in standing, sitting andsquatting positions were done in those ful-filling the study criteria. The maximumflow rate, average flow rate, voiding vol-ume, total voiding time and post-voidingresidual volume were measured andrecorded. The results were then comparedand analysed. Other factors such as nor-mal voiding habit, number of medication,size of prostate, severity of BPO andintravesical prostatic protrusion (IPP) werealso studied for any significance.Results: A total of 123 patients were stud-ied. Majority of patients were more than60 years old (87%) and more than halfwere Chinese (58.5%) followed by Malays(35%) and Indians (5.7%). The commonestvoiding positions among these patientswere standing (78%), sitting, 15 patients(12.2%) and squatting, 12 patients (9.8%).Average IPSS was 12 and majority of themwere in the moderate group (63.4%). Themean size of prostate in this study was42.95 grams. 33 patients had IPP (27.27%)while the rest (72.72%) did not have IP

Internal works quality assessment for wall evenness using vision-based sensor on a mecanum-wheeled mobile robot

Robotics in the construction industry has been used for a few decades up to this present time. There are various advanced robotics mechanisms or technologies developed for specific construction task to assist construction. However, not many researches have been found on the quality assessment of the finished structures. This research proposes a quality assessment robot that will assist in performing the assessment of the internal works of a building by assessing a quality assessment criterion in the Malaysian Construction Industry Standards. There are various assessment criteria such as hollowness, cracks and damages, finishing and jointing. This paper will focus on the wall evenness using a camera mounted on a mobile robot with a Mecanum wheel design. The wall evenness assessment was done via projecting a laser leveler on the wall and capturing the images by using a camera, which is later processed by a central controller. Results show that the deviation calculation method can be used to differentiate between even and uneven walls. Pixel deviations for even walls show values of less than 15 while uneven walls show values of more than 20 pixels

Stability and thermal conductivity of mono and hybrid nanoparticles dispersion in double-end capped pag lubricant

Stable nanolubricant mixtures are interrelated with thermal conductivity enhancement, thus improving heat transfer performance in automotive air conditioning (AAC) systems. This paper studies the stability and thermal conductivity of double-end capped polyalkylene glycol (PAG)-based nanolubricants specially designed for R1234yf refrigerant. Mono nanolubricants (Al2O3/PAG and SiO2/PAG) and hybrid nanolubricants (Al2O3–SiO2/PAG) were prepared using a two-step preparation method at different volume concentrations of 0.01 to 0.05%. The stability of these nanolubricants was observed by visual, UV-Vis spectrophotometer, and zeta potential. Thermal conductivity (k) was measured from 30 to 70 °C using a C-Therm thermal properties analyser. The results from the stability analysis show that all nanolubricants were confirmed in excellent stability conditions for more than six months with minimum visual sedimentation, more than 70% concentration ratio, and zeta potentials greater than 60 mV. The Al2O3–SiO2/PAG samples recorded the highest values of thermal conductivity increment, followed by the Al2O3/PAG and SiO2/PAG samples with 2.0%, 1.7%, and 1.5% enhancement. Hybrid nanolubricants have been shown to have greater potential in the AAC system because of their excellent stability and better property enhancement in thermal conductivity

Viscosity and friction reduction of double end capped polyalkylene glycol nanolubricants for eco friendly refrigerant

In sustainable tribology, researchers are investigating methods to enhance tribological performance by incorporating nanoparticles into lubricants. However, one potential drawback of this strategy is increased lubricant viscosity. The current study aimed to assess the impact of these nanoparticles on the viscosity and coefficient of friction (COF) of the nanolubricants. Three different nanolubricants were synthesized through a two-step process, including mono-nanolubricants (Al2O3/DEC PAG and SiO2/DEC PAG) and hybrid nanolubricants (Al2O3-SiO2/DEC PAG), at volume concentrations between 0.01% and 0.05%. The viscosity and shear flow behavior of these nanolubricants were evaluated using a digital rheometer, while the COF was measured using a Koehler four-ball tribometer. All the nanolubricants showed Newtonian behavior during the experiments. The dynamic viscosity velocity increment of SiO2/DEC PAG was found to be the lowest (1.88%), followed by Al2O3-SiO2/DEC PAG (2.74%) and Al2O3/DEC PAG (3.56%). The viscosity indices of all the nanolubricants were improved only at higher concentrations. At a volume concentration of 0.03%, the Al2O3-SiO2/DEC PAG nanolubricant reduced the COF by up to 8.1%. The results showed that the combination of nanoparticles, temperature, and volume concentration significantly influenced the viscosity and COF of nanolubricants. This study provides essential information for developing high-performance nanolubricants with improved viscosity and COF and advancing environmentally friendly tribology solutions