Effect of Tool Shoulder-to-Pin Diameter Ratio (D/d) on the Mechanical Properties of Friction Stir Processed Mg-Micro Al2O3 Composite

The engineering industry uses magnesium as it is a low density to lightweight ratio material and able to replace the heavier material. Friction stir processing is an applicable method to modify the structural properties of the workpiece. H13 steel tools are produced into several tool parameters with different shoulder diameters to pin diameters (D/d) ratios. A fixed machining parameter of 1040 rpm for spindle speed and 17 mm/min for traverse speed was used throughout this study. Contact between the tool and workpiece produces frictional heat that softens the material. By creating magnesium alloys into metal matrix composites (MMC), microsized aluminum oxide powder (Al2O3) was reinforced during FSP to enhance the mechanical properties of the magnesium alloy AZ91A. The aim of this study is to analyze and obtain the optimal tool parameter to process Mg-Micro Al2O3. The microstructure of FSPed Mg-Micro Al2O3 was observed using a light microscope, specifically on the grain size. The hardness test was done utilizing the Rockwell Hardness Tester to validate the changes in the hardness. The shoulder diameter of 12 mm was found to be the most suitable parameter for processing Mg-Micro Al2O3 as it produced fewer defects and finer grain size

Tangential Film Verification for Lung Volume Involvement in Breast Cancer Radiation Treatment: East Coast Malaysia Experience

Post mastectomy or lumpectomy irradiation of the chest wall or breast is common practice to minimize the local recurrences. Chest wall irradiation is a complicated technical procedure as the pathological target volume involves the normal structures like lung, heart, and head of humerus, esophagus and trachea known as organ at risk. The aim of this study was to verify the cases of the conventional tangential field technique among the breast cancer patients from year 2006 to 2011. In this study, the previous data of breast cancer patients treated with radiation from 2006 to 2011 were evaluated. Conventional 2D planning was done by taking body contour of the patient. Tangential verification films were taken in patients where excess of lung volume was suspected. The data was analyzed to verify the real lung volume irradiated. From a total 112 patients underwent tangential verification films during that period, 33% of patients underwent breast conservative surgery (BCS) while the rest underwent mastectomy. The depth of the field from the skin to 90% isodose ranges from 2.0 to 8.0 cm. However, 15 (13.4%) out 112 patients needed a replanning. As a conclusion, from 112 cases, the numbers of re-plan cases for year 2006 to 2011 were only 13 (11.61%) which is less than 15%. This result can be used by the centre who no dot have the facilities for simulation to verify the depth dose in 2D planning

Surface-Mounted Tilt Sensor Using Fiber Bragg Grating Technology for Engineered Slope Monitoring With Temperature Compensation

A surface-mounted tilt sensor was designed and fabricated to measure the inclination angle of engineered structures or slopes in two directions. The device utilizes two strain-sensitive fiber Bragg gratings (FBGs) for tilt angle measurement bidirectionally and one strain-free FBG to provide temperature compensation. In this work, a tilt sensor prototype was fabricated using a 3-D printer, with a robust enclosure and a miniature actuator with dimensions of 115×65×30 mm and 45×20× 3 mm, respectively. The device was first calibrated in the laboratory for tilt and temperature parameters. For tilt calibration, the device yields a sensitivity value of 0.0135 and 0.0123 nm/° for + x- and– x -directions. On the other hand, the device delivers a sensitivity value of 0.0105 nm/°C as the response to temperature changes. The tilt sensor was also tested for suitability in a real-field deployment where it was installed on a retaining wall and was left for four weeks. The field test data indicate no vertical displacement of the wall since the device exhibits zero inclination changes during the test period. This compact, robust, and easy-to-install tilt sensor has excellent potential for various geotechnical applications, mainly in landslide detections, ground movement, and engineered slope monitoring

Optical fiber Bragg grating-based pressure sensor for soil monitoring applications

An optical-based pressure sensor for a 150 × 150 mm surface was designed and fabricated. The sensor utilizes a fiber Bragg grating (FBG) attached to a 30 × 30 × 30 mm actuator as the pressure sensing mechanism. The middle section of the actuator, which is circular, can bend into an elliptical form and, in the process, pull the FBGP via both ends when force or pressure is applied, thus converting the pressure applied to its surface into a wavelength shift. In laboratory testing, a sensitivity of 0.152 nm∕kPa was obtained. Subsequently, the pressure sensor was tested in the field by burying it 20 cm underground to measure soil pressure, while another FBG was spliced in series to the FBGP to compensate for temperature variations. Testing shows that the proposed design can realize a compact optical-based pressure sensor with enhanced soil monitoring applications such as dynamic soil pressure caused by soil movement

Tunable passively Q-switched thulium doped fluoride fibre (TDFF) laser using reduced graphene oxide-silver (rGO-Ag) as saturable absorber

A tunable, passively Q-switched thulium doped fluoride fibre (TDFF) laser using a reduced-graphene oxide-silver (rGO-Ag) thin film as a saturable absorber (SA) for S band operation is proposed and its efficacy demonstrated. Over a pump power range of 91.4 mW up to 158.6 mW, passively generated Q-switched pulses are observed with repetition rates from 20 to 34.5 kHz and pulse widths from 3.1 to 7.1 µs. The highest pulse energy observed is 101.2 nJ with a signal to noise ratio of ∼ 42 dB. The proposed laser has a tuning range ∼ 52 nm from 1458 to 1510 nm with a tunable bandpass filter (TBPF) introduced into the cavity

Experimental study on the effect of alternator speed to the car charging system

In this paper, we present our work, which is doing an energy audit on alternator’s current output and battery’s voltage based on alternator speed. Up until today, the demand for power in automobile is ever increasing. As technology advances, more and more electrical devices were produced and being installed in vehicles. To cope with the demand, alternator has been designed and modified so that it can produce enough power. This research is to study the effect of alternator speed to the charging system. The car used in this experiment is Proton Preve 1.6 Manual. In both ISO 8854 and SAE J 56, alternator testing and labelling standards indicate that the rated output an alternator is the amount of current that it is capable of producing at 6,000 RPM. Three different constant speed of engine which is 750 RPM as idle speed, 1500 RPM and 3000 RPM as cruise speed were taken as parameter. The speed of the alternator was measured using tachometer, digital multi-meter was used to measure battery’s voltage, and AC/DC Clamp was used to measure alternator current output. The result shows that the faster the alternator spin, the more power it can produce. And when there is more power, the faster the charging rate of the battery