In an earlier study, a three-fingered robot hand was developed for assembly work. Proportional Integral Derivative (PID) control was used to control the position of a DC micromotor measured by an encoder. However, PID control alone could not cater the nonlinearities due to friction of gears and varying loads applied to the finger. Therefore, in order to develop an intelligent control algorithm in future, the effects of varying PID gains need to be investigated to distinguish the optimal value that could produce the best transient response performance. This paper discusses the effect of varying PID gains on position transient response of the joint motor of robot hand through real-time experiments. Several ranges of KP, KI and KD were identified based on the required transient response parameters such as percentage overshoot (%OS), settling time (TS) of within 2%, steady state error (SSE) and rise time (TR). The gains are tuned across the range by a fixed interval with the tuning order starting from KP, KI and KD. It can be observed that the suitable ranges of PID are 0.3 to 0.5 for KP, 1.15 to 1.45 for KI and 0.10 to 0.14 for KD. Meanwhile, the optimum value of 0.4, 1.45 and 0.10 for KP, KI and KD respectively is found to produce 0 of % OS, 5.09 sec of TS and 2.48 sec of TR. Hence, the gains can be applied to the development of an improved position control using intelligent method for the robot hand in future works.
The effect of polypropylene maleic anhydride (PPMAH) on tensile properties and morphology of polypropylene (PP)/recycled acrylonitrile butadiene rubber (NBRr)/ rice husk powder (RHP) composites has been studied. The composites were prepared through melt mixing at 180ºC for 9 minutes using 50 rpm rotor speed. The specimens were analyzed using different techniques, namely tensile test and Scanning Electron Microscopy (SEM). The results obtained showed that the tensile strength and Young’s modulus of the modified composites were increased, while the elongation at break showed the opposite trend as compared with the unmodified composites. The morphology results support the tensile properties and these indicated a better interaction between the filler and matrix with the presence of PPMAH as a compatibilizer.
Compartmented Fluidized Bed Gasifier (CFBG), consisting of two compartments - the combustorand gasifier, uses air blown instead of pure oxygen for syngas production in bubbling fluidization mode, eliminating the need of air separation unit, and reducing the capital cost, thus distinguishes it from other traditional ones. Fluidization quality is a determining factor in the CFBG to guarantee its well-lifted behaviour. Previous study, without solid circulation at ambient conditions, brought to the fore the necessity of considering the effect of the minimum allowable effective diameter. The study was then performed in the CFBG cold physical model of 0.66m overall diameter (effective diameter for combustor and gasifier is 0.413m and 0.257m) to investigate the fluidization quality and compare it with the results obtained from the previous cold model of about 1.36 times smaller, but with the same compartmented ratio of 65:35. Different inert particles (river sand, quartz sand and alumina) were used, over a range of aspect ratios, for the aforementioned objective. The results showed that the fluidization quality in the gasifier has not been achieved and the degradation of fluidization quality in the combustor is still observed, notwithstanding the fact that the condition of the minimum allowable effective diameter has been met. The reduction of distributor free area, to increase the distributor pressure drop, showed a marginal effect on the quality. The effect of the minimum allowable effective diameter on fluidization quality in CFBG as well as the interplay of geometric and operational parameters require further studies be carried out. The fluidization quality of the binary mixture is also currently under investigation.
Sound is a form of wave vibrations that contributes significantly in our daily life. Plants may interact with sound around us but we cannot certainly sure their reaction because of their immobility. Thus, this study intends to find the significant effect between different types of acoustic patterns on the growth of plants. Mung bean or its scientific name, Vigna radiata was chosen as seed material in this experiment due to their short growth cycle. The plants were grown in six environmental chambers with proper ventilations. The chambers were placed on open field with ambient conditions. Mung beans were exposed to five different types of acoustic patterns (soprano, classical, nature, rock, Quranic recitation) with sound pressure level of 60 dB ± 10 dB and one chamber was kept without any acoustic exposure. The length of stem, number of leaves and length of roots were recorded on the 15th day of mung beans’ growth. Experimental results indicate that different types of acoustic patterns promoted the growth of different part of mung beans. Soprano had significant effect on the length of stem while Quranic recitation promoted the production of leaves. However, there is no significant evidence that acoustic exposure stimulates the length of roots.
In the electrodeposition system, adding saccharin alters the properties of the metal deposits by changing the electrode kinetics of the deposited surface. In this study, nanocrystalline cobalt-iron (CoFe) coating was synthesised using the electrodeposition technique with different saccharin concentrations. The results obtained showed that the coating thickness increased while the grain size decreased from 51 nm to 40 nm when the saccharin concentration increased from 0 to 2 g/L. The nanocrystalline CoFe coating produced with 2 g/L of saccharin concentration resulted in the smallest particle size of 71.22 nm and the highest microhardness of 251.86 HV. From the salt spray test (24 and 48 hours) it was found that the use of saccharin at higher concentration of 2 g/L improves the corrosion resistance of the nanocrystalline CoFe coating significantly due to the change of surface morphology as well as the decrease in grain size.
In IEEE 802.11 standard, Mobile Station (MS) such as laptop and smartphone are connected to Access
Point (AP) to have a wireless connection. However, setting up AP to cover the whole area is costly and
complicated. Limitation in signal capacity causes out-of-coverage area, where the MS cannot connect to
the AP. In this paper, a portable wireless range extender (PWRE) is developed to assist MS that is located
out of coverage area, or at the cell edge area connected to the internet. Development of PWRE involves
two processes, which are connecting to existing wireless LAN (WLAN) network, and broadcasting a new
WLAN network. The paper discusses development process of PWRE and analysis of its performance.
PWRE was developed using a low power consumption microprocessor, known as Raspberry Pi.
Performance of the developed PWRE is evaluated by comparing signal strength received by an MS
located in the cell edge from an AP using two scenarios; with and without the PWRE. Results showed
that the MS signal strength improved significantly with the deployment of PWRE. Other advantages
offered by PWRE include being portable and energy efficient as it uses only 5V of power to operate.
Ocean sediments give information on the paleoclimatic evolution in the geological past which gives detailed information on both the age of the sediments and both paleoceanographic and paleoclimatic conditions during sedimentation. One possible way to date sediments is with 210Pb method which can be used to date sediments up to 100 years. In this study, two core samples labelled as JB15 and JB17 were collected using pledging corer, analysed and measured for the activity of 209Po and 210Po using the alpha spectrometer. Applying the methods, average sedimentation rates for JB15 and JB17 were calculated as 0.38 cmyr-1 and 0.43 cmyr-1, respectively. Assuming that the sedimentation rate values are accurate, this might imply that the sediments at the depth of 30 cm were deposited 70 years ago.
State estimation plays a vital role in the security analysis of a power system. The weighted least squares method is one of the conventional techniques used to estimate the unknown state vector of the power system. The existence of bad data can distort the reliability of the estimated state vector. A new algorithm based on the technique of quality control charts is developed in this paper for detection of bad data. The IEEE 6-bus power system data are utilised for the implementation of the proposed algorithm. The output of the study shows that this method is practically applicable for the separation of bad data in the problem of power system state estimation.
Chronic inflammation is associated with processes that contribute to the onset or progression of cancer. This study examined the correlation between dichotomised patients with malignant tumours and inflammatory markers based on the altered glucose metabolism measured by the FDG SUVmax that underpins the degree of tumour aggressiveness. Thirty-one patients underwent 18F-FDG PET/CT for various carcinoma along with blood inflammatory markers such as C-reactive protein (CRP), interleukin-6 (IL6), lipid profile and fasting blood glucose (FBG) levels were obtained in retrospective study. Patients were dichotomised by the cut-off SUVmax value of 6.0 dl/ml derived from curve analysis (P=-0.025). The mean age of the subjects were 53.16 ± 12.06 years and mean SUVmax of 8.80±6.27 g/ml. Significant correlation was noted between the SUVmax and CRP and IL6 (r=0.361; P
The crab carapace is a waste which cannot be decomposed. This waste was used to
remove the Reactive Orange 16 (RO16) and Basic Blue 3 (BB3) from aqueous solution
at different operational parameters such as pH, mass load, the concentrations of dye and
the temperature. The crab collected was modified to obtain quaternized crab (QC) using
(3-chloro-2-hydroxypropyl) trimethylammonium chloride solution (C6H15Cl2NO, 65% w/w
in water). The pH of the dyes solution was varied from pH 4 to 10. The highest adsorption
percentage was achieved at pH 7 for both dyes. Increasing the QC mass for the adsorption
process had granted an increase of dyes removal percentage. The highest adsorption
percentage was achieved at 91.00% for RO16 and 29.40% for BB3 dyes with 7.5 g/L QC
used. However, the adsorption capacity of QC decreased with higher QC mass because the
dye molecules occupied on the surface and prevented other molecules to diffuse into the
QC. At higher concentration beyond 20 mg/L and 10 mg/L of RO16 and BB3, respectively,
the maximum adsorption was achieved at 2.5362 mg/g and 0.6812 mg/g. The adsorption of
both dyes by QC was best fitted using Langmuir isotherm model, explaining the adsorption
mainly occurred as a single layer on the surface of QC. Comparison to the results obtained
from the kinetic models, the adsorption was
chemisorption in nature. According to the
thermodynamic studies, the adsorption of
RO16 was an exothermic, while BB3 was
an endorthermic process.
Execution of the green building project specifically among the housing developers in Malaysia is still at its infancy. As of August 2016, there are only 16 housing projects certified by the Green Building Index (GBI) under the category of Residential New Construction (RNC) since the assessment systems established in 2010. The authors address this issue in the context of the factors affecting the execution of the green building project among the housing developers in Klang Valley. A pilot study by using questionnaire survey was conducted among 30 housing developers from 10 different zones divided by the Ministry of Housing and Local Government, Malaysia. This paper aimed to report the results of the reliability test of the designed questionnaire. The results based on the Cronbach’s Alpha analysis showed that the items used in the questionnaire were reliable and obtained an acceptable level of internal consistency, which were relevant for the main study. The pilot study revealed that only 9 out of 30 respondents had the completed or ongoing green building projects. The findings exposed the level of knowledge, emotion, value, attitude, behavior and the potential factors affecting the execution of the green building projects among the housing developers in Klang Valley.
This research focuses on the ASTER DEM generation for visual and mathematical analysis of topography, landscapes and landforms, as well as modeling of surface processes of Central Alborz, Iran. ASTER DEM 15 m generated using tie points over the Central Alborz and Damavand volcano with 5671 m height from ASTER (Advanced Space borne Thermal Emission and Reflection Radiometer) satellite data using PCI Geomatica 9.1. Geomorphic parameters are useful to identify and describe geomorphologic forms and processes, which were extracted from ASTER DEM in GIS environment such as elevation, aspect, slope angle, vertical curvature, and tangential curvature. Although the elevation values are slightly low in altitudes above 5500 m asl., the ASTER DEM is useful in interpretation of the macro- and meso-relief, and provides the opportunity for mapping especially at medium scales (1:100,000 and 1:50,000). ASTER DEM has potential to be a best tool to study 3D model for to geomorphologic mapping and processes of glacial and per glacial forms above 4300 m asl.
Reliance on modern sophisticated equipment for making ‘discoveries’ has limited the human power of observing subtle clues in the environment that are capable of saving cost and labour that come with researching new resources and methods to improve life for all. Due to the growing scarcity of potable water, especially in African and Asian countries, newer, cheaper and reliable methods of investigating groundwater resources are becoming critical. One such potentially promising method is mapping the distribution of termite mounds in the environment. Termite mounds are conspicuous landscape features in tropical and sub-tropical regions of the world. Built from surrounding soils by several species of termite, the properties of mound soil are relatively different from the surrounding soil in most cases, indicating improved hydraulic properties. In this paper, the aim is to review the possibility of employing termite mounds as prospecting tools for groundwater search from three spatial scales of observation. From assessing the smallest to the highest scale of observation, it can be concluded that termite mounds’ prospect as surface indicators of groundwater is apparent. Review findings indicate increased surface water infiltration, presence of riparian tree vegetation and other trees with tap-root system around termite mounds, linear assemblage of termite mounds along aquiferous dykes and seep-lines as well as the dependence of termites on water but avoidance of places with risk of inundation. Whether they indicate permanent groundwater reserves in all cases or whether all species depend largely on water for their metabolism is a subject for further research.
This paper presents a study on the effect of Arenga Pinnata fibre volume fraction on the tensile and compressive properties of Arenga Pinnata fibre reinforced epoxy composite (APREC). The composites were produced using four different Arenga Pinnata fibre volume contents, which were 10vol%, 15vol%, 20vol%, and 25vol%, in unidirectional (UD) fibre alignment. Tensile and compression tests were performed on all APREC specimens in order to investigate the effect of fibre volume fraction on modulus of elasticity, strength and strain to failure. The morphological structure of fractured specimens was observed using scanning electron microscopy (SEM) in order to evaluate the fracture mechanisms involved when the specimens were subjected to tensile or compressive loading. The results indicated that the higher the amount of Arenga Pinnata fibres, the higher the stiffness of the composites. This is shown by the increment of tensile and compressive modulus of the specimens when the fibre volume content was increased. Tensile modulus increased up to 180% when 25vol% Arenga Pinnata fibre was used in APREC compared to Pure Epoxy specimen. It can also be observed that the tensile strength of the specimens increased 28% from 53.820 MPa (for Pure Epoxy) to 68.692 MPa (for Epoxy with 25vol% APREC addition). Meanwhile, compressive modulus and strength increased up to 3.24% and 9.17%, respectively. These results suggest that the addition of Arenga Pinnata fibres significantly improved the tensile and compressive properties of APREC.
This paper focuses on examining the ‘cutting zone temperature’ while performing turning operation
on AZ91Mg alloy using cemented carbide tools. The regression model is developed by using the RSM
techniques based on experimental results. It is revealed that the cutting speed (v) is the most dominant
factor affecting cutting zone temperature. The developed models of cutting zone temperature sufficiently
map within the range of the turning conditions considered. The adequacy and accuracy of the regression
equation is justified through ANOVA. It is found that the optimal combinations of machining parameters
minimize the cutting temperature.
Dispersibility of nanoparticles is the key problem in nanotechnology industries, and thus warrants
attention on the techniques of dispersion. This review paper presents dispersibility of treated nanoparticles
in polymer resin. Dispersibility of nanoparticles in polymer media is crucial in order to enhance the
mechanical and thermal properties of nanocomposite. This paper concentrates on several preparations
on how to incorporate nanoparticles in polymer to overcome the problem described in this review. A
few techniques are discussed in this paper such as by using ultra sonication or even directly mixing
nanoparticles into polymer matrix.
This paper analyses electromagnetic signal scattered from the target crossing the Forward Scattering
Radar (FSR) system baseline. The aim of the analysis was to extract the Doppler signal of a target under the influence of high ground clutter and noise interference. The extraction was used for the
automatic target detection (ATD) in the FSR system. Two extraction methods, namely Hilbert Transform and Wavelet Technique, were analyzed. The detection using the Hilbert Transform is only applicable for some conditions; however, the detection using the Wavelet Technique is more robust to any clutter and noise level. From 55 sets of signal, only 4% of false alarm was detected or occurred when the Wavelet Technique was applied as a detection scheme. Two sets of field experimentation were carried out and the target’s signal under the influence of high clutter had successfully been detected using the proposed method.
Quality Function Deployment (QFD) is a structured methodology that uses customer and technical
requirements for designers and manufacturers to provide better products. Many researchers combine or
integrate the technique of QFD with other methodologies such as Theory Inventive of Problem Solving
(TRIZ) or Design for Manufacture and Assembly (DFMA) to optimise product design innovation and
improvement. The combined methodologies are even used to solve process problems. Initial literature
review of the application of stand-alone QFD poised several problems. Combining QFD with other
techniques, such as TRIZ and DFMA, has helped to address these issues and forms the basis of future
research. The integrated methods can solve main contradictory problems more precisely from product
demand analysis to product design, production and application. Review work of the literature, specifically
that on research and development of QFD, TRIZ and DFMA, showed that the said methodologies have
been widely and successfully implemented in several practical applications such as resolving conflicts
between customer and technical/engineering requirements and reducing production cost. This review work
provides an in-depth analysis of identifying and finding issues of strengths, weaknesses and outcomes
of the QFD when combined with TRIZ and also of QFD integrated with DFMA.
In this paper, we introduce T-DepExp system to simulate the transitive dependence based coalition formation (CF). It is a multi-agent based simulation (MABS) tool that aims to enhance cooperation between agents through transitive dependence. Previously, the transitive dependence was introduced by An and his colleagues for expressing the indirect dependence between agents in their cooperation. However, it did not receive much attention. Although it has a few problems need to be addressed, we try to propose our own mechanism to increase the efficiency of the transitive dependence based CF. To simulate MAS dependence relationship, we have included two fundamental dependence relationships in this MABS tool, which are AND-Dependence and OR-Dependence. In addition, the architecture of the T-DepExp system is presented and discussed. It allows possible integration of other features such as budget mechanism and trust model. Subsequently, hypothesis for the experiments and experimental setup are explained. The overall system will be demonstrated for its functionality and the experimental results will also be discussed.
Previous studies have indicated that the pipe-surface-mounted helical strakes effectively reduce vortex-induced vibration (VIV) under a uniform flow application, particularly during the lock-in region. Since VIV experiments are time-consuming, observation is generated with an interval helical strakes parameter in pitch and height to lessen tedious procedures and repetitive post-processing analyses. The aforementioned result subset is insufficient for helical strakes design optimisation because the trade-off between the helical strakes dimension, lock-in region and flow velocity are non-trivial. Thus, a parametric model based on an improved recursive least squares (RLS) parameter estimation technique is proposed to define the statistical relationship between input, or strakes and pipe dimension, and output, or VIV amplitude ratio. As results suggested, revised RLS estimated VIV model demonstrated an optimal prediction with the highest coefficient of determination and lowest Integral Absolute Error. The feasibility of VIV parametric model was validated by embed into Genetic Algorithm (GA) as the fitness function to acquire a desirable helical strakes dimension with minimum VIV amplitude. The rapid generation of optimal helical strakes dimension which returned the highest VIV suppression implied a superior simulation method compared to the experimental outcome.