Some effects of earthquakes at North Sumatra to the total electron content in the Ionosphere

Total Electron Content (TEC) is an important ionospheric and space weather param- eter used for characterizing the state and dynamics of plasma in the ionosphere. As a result, this study was carried out to examine the possible relationship between the variations of the TEC in the ionosphere and the earthquakes and to identify the ef- fects of earthquakes to the TEC in the ionosphere. The analysis of ionospheric TEC variations were made using the Global Positioning System (GPS) station installed at Wireless and Radio Science Centre (WARAS), Kolej Universiti Teknologi Tun Hus- sein Onn (KUiTTHO), Johor (Latitude 1 ̊52 ́ N, longitude 103 ̊48 ́ E). Five cases of strong earthquakes at Indonesia in 2005 with M > 6.0 were selected as case studies. The TEC variations analysis of the GPS TEC collected by the GPS receiver in the year of 2005 were made to identify any TEC variations associated with earthquakes. Pronounced TEC variations around the time of earthquakes were analyzed with re- spect to the TEC variations during non-earthquake period. From the analysis, it was found that there appears to be rapid changes in TEC within 0 to 6 days before the earthquakes. Besides that, the TEC variations for all the cases show that the TEC gradually recovered to normal within 1 to 3 days after earthquakes. As a conclusion, strong earthquakes are reported to have caused disturbances in the ionosphere that can be measured with GPS as short-period changes in the TEC. The ionospheric TEC variations with average ∆ TEC = 10 TECU can be considered as a possible earthquake precursory

Development of Wireless Electronic Nose Using NRF24L01 RF Transceiver for Toxic Gases Monitoring

Exposure to toxic gases will affect the well-being of people in the nearby area if it is not carefully monitored. This study proposes a Wireless Electronic Nose (e-nose) System to monitor some toxic gases, temperature and humidity in the environment. The environment is monitored by using four units of wireless e-nose known as node, positioned at pre-determined locations. The node consists of toxic gases sensors as well as temperature and humidity sensor that acquired data from the environment in 30 minutes interval. The acquired data is sent wirelessly to the main node through NRF24L01 Radio Frequency (RF) transceiver. The main node transmits the data to a web of things system via Mobile Communication/General Radio Packet Service (GSM/GPRS) module. The acquired data is analysed using Principal Component Analysis (PCA), Hierarchical Cluster Analysis (HCA) and Radial Basis Function (RBF) of the Artificial Neural Network (ANN). Initial result shows that the system is able to monitor the toxic gases in the testing area

Stress intensity factors for surface cracks in round bar under single and combined loadings

This paper numerically discusses stress in-tensity factor (SIF) calculations for surface cracks in round bars subjected to single and combined loadings. Different crack aspect ratios, a/b, ranging from 0.0 to 1.2 and the relative crack depth, a/D, in the range of 0.1 to 0.6 are considered. Since the torsion loading is non-symmetrical, the whole finite element model has been constructed, and the loadings have been remotely applied to the model. The equivalent SIF, F∗EQ is then used to combine the individual SIF from the bending or tension with torsion loadings. Then, it is compared with the combined SIF, F∗FE obtained numerically using the finite element analysis under similar loadings. It is found that the equivalent SIF method successfully predicts the combined SIF, F∗EQ for Mode I when compared with F∗FE . However, some discrepancies between the results, determined from the two different approaches, occur when FIII is involved. Meanwhile, it is also noted that the F∗FE is higher than the F∗EQ due to the difference in crack face interactions and de-formations

Characterisation of Thermal Barrier Coating on Piston Crown for Compressed Natural Gas Direct Injection (CNGDI) Engines

The high temperature and pressure produced in an engine that uses compressed natural gas with direct injection system (CNGDI) may lead to high thermal stresses. The piston crown fails to operate effectively with insufficient heat transfer. In this study, partially stabilized zirconia (PSZ) ceramic thermal barrier coatings were plasma sprayed on CNGDI piston crowns (AC8A aluminium alloys) to reduce thermal stresses. Several samples were deposited with NiCrAl bonding layers prior to the coating of PSZ for comparison purposes. Detailed analyses of microstructure, hardness, surface roughness, and interface bonding on the deposited coating were conducted to ensure its quality. High stresses were mainly concentrated above the pinhole and edge areas of the piston. In short, the PSZ/ NiCrAl coated alloys demonstrated lesser thermal stresses than the uncoated piston crowns despite a rough surface. Extra protection is thus given during combustion operation

Rice Leaf Blast Disease Detection Using Multi-Level Colour Image Thresholding

Rice diseases have caused a major production and economic losses in the agricultural industry. To control and minimise the impacts of the attacks, the diseases need to be identified in the early stage. Early detection for estimation of severity effect or incidence of diseases can save the production from quantitative and qualitative losses, reduce the use of pesticide, and increase country’s economic growth. This paper describes an integrated method for detection of diseases on leaves called Rice Leaf Blast (RLB) using image processing technique. It includes the image pre-processing, image segmentation and image analysis where Hue Saturation Value (HSV) colour space is used. To extract the region of interest, image segmentation (the most critical task in image processing) is applied, and pattern recognition based on Multi-Level Thresholding approach is proposed. As a result, the severity of RLB disease is classified into three categories such as infection stage, spreading stage and worst stage

Finite element analysis of j-integral for surface cracks in round bars under combined mode i loading

This paper numerically discusses the role of J-integral along the surface crack front in cylindrical bar under combined mode I loading. It is also verified the analytical model derived from the first part of this paper by comparing the results obtained numerically using ANSYS finite element program. It is found that the proposed model capable to predict the J-integral successfully along the crack front but not for the area away from the deepest crack depth. This is probably due to the fact that the problem of singularity

Genetic Diversity Of Duabanga Moluccana Using Dominant Dna Markers Based On Inter-Simple Sequence Repeats In Sarawak

Duabanga moluccana or locally known as Sawih is a widely known forest tree species for its multipurpose timber and other natural products such as fibers. Genetic diversity investigation of this species can provide baseline information for indirect selection in tree improvement programme. This study has employed Inter Simple Sequence Repeat (ISSR) technique to assess the genetic diversity and relatedness within and between three populations of D. moluccana located in Sarawak, namely, Mukah, Tatau (Bintulu) and Niah. A total of 151 loci from 90 individuals were successfully amplified with 6 selected ISSR primers and the percentage of polymorphic loci was 90.1%. The Shannon’s diversity index showed that D. moluccana in Mukah natural forest (0.429) was the most diverse compared to Tatau (Bintulu) (0.362) and Niah natural forest (0.387). Neighbour joining tree were constructed to show relationship among the selected populations. The overall populations were completely clustered into three main groups, according to their corresponding population. Based on these results, it implies that D. moluccana trees are genetically diverse among populations

Parity-Violating Excitation of the \Delta(1232): Hadron Structure and New Physics

We consider prospects for studying the parity-violating (PV) electroweak excitation of the \Delta(1232) resonance with polarized electron scattering. Given present knowledge of Standard Model parameters, such PV experiments could allow a determination of the N -> \Delta electroweak helicity amplitudes. We discuss the experimental feasibility and theoretical interpretability of such a determination as well as the prospective implications for hadron structure theory. We also analyze the extent to which a PV N -> \Delta measurement could constrain various extensions of the Standard Model.Comment: 43 pages, RevTex, 8 PS figures, uses epsf.sty, rotate.sty, version to appear in Nucl. Phys. A, main points emphasized, some typos correcte

Detection of Colletotrichum Gloeosporioides Fungus Isolates Development/Spread for Mango (Mangifera Indica L.) Cultivar from Electronic Nose Using Multivariate-Statistical Analysis

Agriculture plays a very important role in Asia economic sectors. For Malaysia, it plays a big contribution towards the country’s development. Mangifera Indica L., commonly known as Mango, is one of the fruit that has high economic demand and potential in Malaysia export business. However, due to radical climate changes from hot to humid, Mango is exposed towards a number of disease and this will affect its production. Colletotrichum gloeosporioides is one of the major diseases that could occur on any types of Mango. This fungus can attack on fruit skin and leaf, therefore a method that able to detect and control it would be much appreciated. Hence, this paper shows that the presence of Colletotrichum gloeosporioides type of pathogen can be detected by using Electronic Nose (E-Nose). The E-Nose will detect the Volatile Organic Compound (VOC) that produced from this fungus. Further analysis and justification on its existence are completed by using one of Multivariate-Statistical Analysis method which is Principal Component Analysis (PCA).The analysis results effectively show that the PCA is able to classify the number of isolating days of this type of fungus after cultured. Furthermore the potential of pre-symptomatic detection of the plant diseases was demonstrated