2,956 research outputs found

    Thermal Conductivity and Viscosity Of Al2o3 Nanofluids for Different Based Ratio of Water and Ethylene Glycol Mixture

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    In the thermal engineering applications, suspension of nanoparticles in conventional fluid has positive potential in enhancing the convective heat transfer performance. The evaluation of thermo-physical properties is essential to investigate the forced convection heat transfer of nanofluids. Hence, the present study reports the analysis on thermal conductivity and dynamic viscosity for Al2O3 nanoparticle dispersed in a different volume ratio of water (W) and ethylene glycol (EG) mixture. The Al2O3 nanofluids are formulated using the two-step method for three different base mixtures with volume ratio of 40:60, 50:50 and 60:40 (W:EG). The measurement of thermal conductivity and viscosity were performed using KD2 Pro Thermal Properties Analyzer and Brookfield LVDV-III Rheometer; respectively for temperature from 30 to 70 °C and volume concentration of 0.2–1.0%. The average thermal conductivity enhancement of Al2O3 nanofluids in the three base ratios varied from 2.6 to 12.8%. The nanofluids have better enhancement as the percentage of ethylene glycol increases. Meanwhile, the average dynamic viscosity enhanced up to 50% for 60:40 (W:EG). The enhancement of viscosity for nanofluids decreased with the increment percentage of ethylene glycol. The properties enhancement of the Al2O3 nanofluids is significantly influenced by the concentration, temperature, and based ratio

    The use of Linear Statistical Model to Predict Tumour Size of Colorectal Cancer

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    Colorectal cancer (CRC) is a type of cancer in the large intestine (colon), the lower part of our digestive system. Most cases of colon cancer begin as small non-cancerous clumps of cells called adenomatous polyps. The aim of this quantitative study is to identify the determinants of patient who have colorectal cancer symptoms in general hospital. The sample study included 180 patients who have colorectal cancer aged above 21 years old and received treatment at general hospital in Kuala Lumpur, Malaysia. Secondary data were obtained through doctors and nurses using cluster sampling. Based on the results of multiple linear regressions (MLR), 11 predictor variables were significant to predict tumour size of colorectal cancer. The statistical measurement error used were mean square error (MSE), root mean square error values (RMSE), mean absolute error (MAE) and mean absolute percentage error (MAPE)

    Evaluation of Double Loop IC Module for Inductive Coupled Fed RFID Tag Wire Embedded Antenna

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    This paper presents an evaluation on double loop integrated circuit module for inductive couple fed RFID Tag. The inductive couple feed gives advantage especially for flexible wire embedded antenna in controlling the manufacturing varians as the chip is not directly connected to the antenna. Thus electrostatic discharged effect and manufacturing errors can be minimized. An inductor loop is directly connected to the RFID chip before it is placed to indirectly coupled the energy from a meandered dipole antenna. The coupled energy should be enough to turn on the chip to communicate with the reader. The inductive coupled energy is achieved by manipulating the near field magnetic field between the antenna body and the inductor loop. To evaluate the performance, the antenna and the inductive feeding loop is designed to operate at RFID UHF band (860 MHz – 960 MHz) and simulated using CST software. The antenna body impedance is evaluated to match the impedance of the chip and the loop. It is confirmed that the double loop inductor has higher inductance values and thus should be counted in conjugate impedance between the antenna body and the chip module. The tag with overall dimension of 60 mm x 16 mm can be read at distance at least 9 meters through out the band

    UNDERSTANDING THE EFFECTS OF INTERPERSONAL COMMUNICATION AND TASK DESIGN ON JOB PERFORMANCE AMONG EMPLOYEES IN THE MANUFACTURING COMPANY

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    on job performance among employees from the manufacturing industry. Methodology: The data is analyzed through a survey (questionnaire) from 152 employees in one of the manufacturing companies in Penang, Malaysia. Hypotheses for all direct effects between the predictors (eg. interpersonal communication and task design) and criterion (job performance) are tested using regression analysis.  Result: Results presented that employees in this company have a high level of job performance (µ = 3.70); interpersonal communication (µ =3.64) and task design (µ =3.66). Also, positive correlations are found between employees’ performance and interpersonal communication (r=.53, p=.00) and task design (r=.54, p=.00). Implications: Thus, this research provided a fruitful knowledge regarding the level of employees’ performance as well as their internal communication and task design; among employees in one of the manufacturing company in Malaysia

    Window-based channel impulse response prediction for time-varying ultra-wideband channels

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    This work proposes channel impulse response (CIR) prediction for time-varying ultra-wideband (UWB) channels by exploiting the fast movement of channel taps within delay bins. Considering the sparsity of UWB channels, we introduce a window-based CIR (WB-CIR) to approximate the high temporal resolutions of UWB channels. A recursive least square (RLS) algorithm is adopted to predict the time evolution of the WB-CIR. For predicting the future WB-CIR tap of window wk, three RLS filter coefficients are computed from the observed WB-CIRs of the left wk-1, the current wk and the right wk+1 windows. The filter coefficient with the lowest RLS error is used to predict the future WB-CIR tap. To evaluate our proposed prediction method, UWB CIRs are collected through measurement campaigns in outdoor environments considering line-of-sight (LOS) and non-line-of-sight (NLOS) scenarios. Under similar computational complexity, our proposed method provides an improvement in prediction errors of approximately 80% for LOS and 63% for NLOS scenarios compared with a conventional method

    Thermo-physical properties of TiO2-SiO2 hybrid nanofluids dispersion with water/bio-glycol mixture

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    Introducing nanoparticles in liquid-based mixtures began to gain attention in various industries. This is supported by previous studies to improve the performance and provide energy saving for the system. Among its uses is in the VCRS and automotive air conditioning (AAC) system. The lubricant used in this system has the potential to have a good effect on the performance. Before testing the nano-lubricant enhancement performance, an automotive air conditioning (AAC) system test rig based on hybrid electric vehicles (HEV) AC system has to be developed; therefore, this paper presented the development process of AAC test rig specific for the HEV. In order to analyze the performance, 11 thermocouples, digital pressure gauges with the data logger, and AC/DC power clamp were assembled and used. After that, the experiment was conducted with five different initial refrigerant charges and three different compressor speeds. This method was applied to both pure POE lubricant and SiO2/POE nano-lubricant. Then, the heat absorbs, compressor work, and coefficient of performance (COP) were evaluated. The highest average COP for SiO2/POE nano-lubricant was achieved at a 40 % duty cycle (2520 RPM) speed with a value of 2.84. The highest enhancement of the COP is 25.1% at 60% duty cycle (3180 RPM) speed with 160 grams of initial refrigerant charged an average enhancement of the COP is 13.16%

    Steering intervention strategy for side lane collision Avoidance

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    Advance Driver Assistance Systems (ADAS) have successfully been integrated in many vehicles; however, the research on its improvement is still on-going. Some of the features of ADAS include Lane Departure warning System, Blind Spot detection, Lane Change Assistance and etc. However, with such systems available, accidents still occurred due to the driver's lack of awareness and negligence towards the given indication and warning, especially situation related to side lane collision. Thus, this paper aims to propose a simple steering intervention control. If the driver still proceed for the lane change when there are other object appearing in the blind spot area, the proposed solution will automatically trigger vehicle evasion mode to avoid side lane collision. The system does not take into account comfort in order to warn the driver. The system was tested and validated using a test vehicle. The results show that the steering intervention provides good vehicle evasion results and hypothetically it may act as the final warning towards the person behind the wheel

    I-Drive: Modular system architecture and hardware configuration for an intelligent Vehicle research platform

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    There are many researches in the field of autonomous and Intelligent Vehicle in Malaysia, but most of them never have the chance to be tested in actual environment due to constraints in terms of hardware and its configuration. Thus, this paper aims to share with other researchers in the field of Autonomous and Intelligent Vehicle with our independent modular-based system and hardware configuration of an Autonomous and Intelligent Vehicle research platform at our university. Each of the research projects are represented by a module and they are linked by a communication layer. The modules utilised the communication layers to transmit and received data as a part of system communication network, and finally this configuration build up the whole system. Through this approach, it is hoped that the contribution from each research project leads to fully autonomous vehicle and intelligent vehicle. The proposed modular system and hardware configuration have been successfully verified via our platform through lane-keeping research. The proposed platform is demonstrated via I-DRIVE (Intelligent Drive Vehicle) on the standard testing track and Malaysia highway road

    I-Drive: Modular system architecture and hardware configuration for an intelligent Vehicle research platform

    Get PDF
    There are many researches in the field of autonomous and Intelligent Vehicle in Malaysia, but most of them never have the chance to be tested in actual environment due to constraints in terms of hardware and its configuration. Thus, this paper aims to share with other researchers in the field of Autonomous and Intelligent Vehicle with our independent modular-based system and hardware configuration of an Autonomous and Intelligent Vehicle research platform at our university. Each of the research projects are represented by a module and they are linked by a communication layer. The modules utilised the communication layers to transmit and received data as a part of system communication network, and finally this configuration build up the whole system. Through this approach, it is hoped that the contribution from each research project leads to fully autonomous vehicle and intelligent vehicle. The proposed modular system and hardware configuration have been successfully verified via our platform through lane-keeping research. The proposed platform is demonstrated via I-DRIVE (Intelligent Drive Vehicle) on the standard testing track and Malaysia highway road

    Thermal conductivity and viscosity of Al2O3 nanofluids for different based ratio of water and ethylene glycol mixture

    Get PDF
    In the thermal engineering applications, suspension of nanoparticles in conventional fluid has positive potential in enhancing the convective heat transfer performance. The evaluation of thermo-physical properties is essential to investigate the forced convection heat transfer of nanofluids. Hence, the present study reports the analysis on thermal conductivity and dynamic viscosity for Al2O3 nanoparticle dispersed in a different volume ratio of water (W) and ethylene glycol (EG) mixture. The Al2O3 nanofluids are formulated using the two-step method for three different base mixtures with volume ratio of 40:60, 50:50 and 60:40 (W:EG). The measurement of thermal conductivity and viscosity were performed using KD2 Pro Thermal Properties Analyzer and Brookfield LVDV-III Rheometer; respectively for temperature from 30 to 70 °C and volume concentration of 0.2–1.0%. The average thermal conductivity enhancement of Al2O3 nanofluids in the three base ratios varied from 2.6 to 12.8%. The nanofluids have better enhancement as the percentage of ethylene glycol increases. Meanwhile, the average dynamic viscosity enhanced up to 50% for 60:40 (W:EG). The enhancement of viscosity for nanofluids decreased with the increment percentage of ethylene glycol. The properties enhancement of the Al2O3 nanofluids is significantly influenced by the concentration, temperature, and based ratio
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