Numerical Modelling of Soft Soil Improvement Using Expanded Polystyrene Geofoam for Road Embankment

Soft soil brings abundant engineering issues due to low bearing capacity and shear strength. A comprehensive study of soft ground needs to be reviewed and identified before construction can start. Various techniques can be used to improve the soil. However, this study focuses on using material, namely expanded polystyrene. The geotextile is embedded with expanded polystyrene to strengthen the soil condition. This study adopted the soil parameters from East Coast Expressway 2. There are two models in this study, which are earth embankment and EPS embankment. The settlement of the earth embankment is compared with the EPS embankment after construction. The Mohr-Coulomb parameters are used to model soft soil and embankments, while the linear elastic parameters were adopted to model the EPS and geotextile. This study produced two embankment models, the conventional embankment models with and without surcharge. The second model is an EPS embankment with various densities (22 kg/m3, 29 kg/m3, and 39 kg/m3). The settlement is recorded for ten years after the embankment construction was completed. The difference settlement value for the conventional model is 28 mm. The settlement value for EPS 22 is 3.18 mm, EPS 29 is 2.06 mm, and EPS 39 is 1.51 mm. For the geotextile embedded with EPS settlement value, EPS 22 is 3.17 mm, EPS 29 is 2.04 mm, and EPS 39 is 1.49 mm. Since EPS uses three different densities, from the prediction of PLAXIS 2D, the higher density gives the lower value of the settlement. However, when the geotextile is embedded with EPS, there is no significant difference when using geotextile. In conclusion, the model with a surcharge gives a lower settlement than the model without a surcharge. But the expanded polystyrene block is the best model to reduce the settlement compared with the conventional model with a surcharge. Different density of EPS gives different settlement value, and EPS 39 gives the lowest settlement value. In terms of the geotextile embedded with EPS, it does not give a significant settlement

Plaxis 2D Modelling of an Anchor Sheet Pile for Soil Slope Strengthening at Segamat, Johor

In soil engineering, the soil slope is one of the important issues in geotechnical and environmental engineering that can fail due to settlement behaviour. Due to soil slope instability, roads near the Segamat River’s slopes have seen severe settlement. Therefore, this study was carried out to determine how the geometry of the soil slope and the properties of the soil affect soil stability and deformation. Because of the varying slope geometries along the river, this study used two alternative slope geometries in its modelling. A comparison was made between the existing slope and the slope stabilised with sheet piling by using Plaxis 2D. Other parameters that affect slope stability are also being investigated, such as anchor length and anchor installation angle. The anchor sheet pile's presence is intended to improve the slope's stability. As a result of this analysis using PLAXIS 2D software, the optimal anchor length depends on the passive pressure of the soil behind the sheet pile. According to the results, installing an anchor with a 60° angle is more stable because the safety factor obtained is 3.26 which is greater than that of a 45° angle which is 1.33. It shows the anchor is the best support of the sheet pile for the soil slope stability

Sintesis dan pencirian getah asli cecair terhidrogen untuk adunan polimer

Sistem hidrazin hidrat/hidrogen peroksida (HH/H2O2) digunakan untuk menjana sumber hidrogen bagi tujuan penghidrogenan getah asli cecair (LNR) melalui penghasilan diimida. Spesies diimida yang terhasil akan membekalkan sumber hidrogen kepada ikatan karbon ganda dua dalam rantai polimer LNR. Getah asli cecair terhidrogen (HLNR) yang terhasil menunjukkan ciri lebih tahan suhu berbanding LNR. Suhu degradasi HLNR didapati meningkat pada 435°C berbanding LNR iaitu pada 381°C. HLNR seterusnya dijadikan pengserasi dalam penghasilan adunan polimer polistirena/getah asli, PS/NR/HLNR (60/35/5). Kekuatan regangan dan impak PS/NR masing-masing meningkat sebanyak 70.7% dan 149.6% setelah HLNR ditambah sebagai pengserasi dalam adunan. Beberapa pemerhatian morfologi melalui mikroskop optik dan SEM turut menyokong kesan penyerasian adunan PS/NR dengan HLNR

Compact wideband frequency reconfigurable metamaterial antenna design

This paper presents the design of compact wideband frequency reconfigurable metamaterial (MTM) antenna. The design is based on the idea of obtaining single and multi-bands in wideband metamaterial antenna within the range of bandwidth. This is achieved by introducing capacitive slots which neutralize inductive properties and generate left handed capacitive parameter. The three series slots in the patch contribute for bandwidth enhancement while two PIN Diode Switches provide multi-bands operation. Computer Simulation Technology (CST) software is used to determine the operation and effectiveness of the proposed antenna. The approach has several notable merits which include improvement of spectrum utilization, minimize spectrum congestion, interference and provide bands selectivity. From the simulation results, it was found that, bandwidth was improved to 2.8 GHz which is equivalent to 82% fractional bandwidth. Also, it can switch to seven different frequency bands of operation with only two number of switches. The realized peak gain is 2.44 dBi and 3.15 dBi at 2.4 GHz and 5.0 GHz respectively with average efficiency of 95%. The antenna can be utilized for wireless communication and cognitive radio application

Pengoptimuman parameter untuk penurunan diimida getah asli cecair dalam sistem hidrazin hidrat/hidrogen peroksida menggunakan kaedah rangsangan permukaan (RSM)

Getah asli cecair (LNR) dihasilkan daripada proses penyahpolimeran getah asli yang menghasilkan rantaian polimer lebih pendek dan berat molekular kurang daripada 105. Namun, LNR masih mempamerkan tahap degradasi dan ketahanan termal yang rendah seperti getah asli, disebabkan oleh kehadiran ikatan karbon ganda dua pada rantaian polimer. Dalam kajian ini, penurunan diimida menggunakan pengoksidaan hidrazin hidrat dengan hidrogen peroksida dijalankan untuk menghidrogenkan unit tidak tepu LNR. LNR terhidrogen (HLNR) dicirikan menggunakan spektrometer infra-merah (FTIR) dan spektrometer resonans magnetik nuklear (NMR). Pengoptimuman parameter tindak balas dilakukan dengan memanipulasi parameter masa dan suhu tindak balas berdasarkan kaedah rangsangan permukaan (RSM) dengan 5-aras-2-faktor reka bentuk komposit putaran tengah (CCRD). Satu model kuadratik yang signifikan telah dihasilkan untuk menghubungkan dua parameter tersebut dengan nilai R2 adalah 0.9986, menunjukkan bahawa model yang terhasil adalah sangat sepadan dengan data uji kaji. Keputusan kajian menunjukkan bahawa peratus penghidrogenan boleh ditingkatkan sehingga 91.2%. Seterusnya, berdasarkan RSM, parameter yang optimum bagi penurunan diimida LNR ini didapati pada suhu 55.9oC selama 6.7 jam, menghasilkan 80.2% HLNR. Kajian ini telah menunjukkan reka bentuk uji kaji secara statistik yang novel bagi menghidrogenkan LNR. Pelbagai variasi peratus penghidrogenan produk HLNR dalam kajian ini menyumbang kepada lebih banyak aplikasi produk yang memerlukan peratusan ketepuan unit yang tertentu

A review on frequency synchronization in collaborative beamforming: a practical approach

Coherent signal reception from distributed beamforming nodes of virtual antenna array formation requires frequency synchronization of the participating nodes. Signals at the target receiver are out of phase due to unsynchronized local oscillator’s (LO) reference signal of all the nodes in the systems. Practical cases of this problem are considered. In this article, a brief overview is presented of the need for the frequency synchronization and the resulting effect of mitigation avoidance. A variant of the closed-loop feedback algorithm is used to provide LO drifts information to the beamforming transmitters. These feedbacks are used to estimate, correct, and predict the nonlinear LO offsets that will result in near (0) phase offset of the received signal. The algorithms are implemented in software defined radio (SDR) and transmitted through the RF front end of devices like the NI 2920/N210 USRP

Design optimization of single-phase inner-rotor and outer-rotor hybrid excitation flux switching machine for EV applications

Electric Vehicle (EV) is considered as an ultimate eco-friendly car and this is highly expected to be popularized in the future. One of the main candidates of electric machine for an EV drive is a flux switching machine (FSM). However, since the designed machine consists of three-phase complicated winding, the copper loss which contributes to efficiency of the machine is expected to be increased. Furthermore, the three-phase armature winding has a large area size of the total system. Due to the complicated three-phase armature winding that contribute to high copper losses, a single-phase inner-rotor and outer-rotor Hybrid Excitation Flux Switching Machine (HEFSM) with much simpler structure and less armature coil consumption are introduced in this research. Various characteristics of HEFSM are investigated by analytical approaching based in finite element analysis using JMAG software. The project implementation of this research is divided into three parts including design, analyze and optimize. Firstly, the impact of a rotor pole number of the proposed is investigated for inner-rotor and outer-rotor configuration in order to determine the optimal performances of the rotor poles combinations. Then 8S-4P and 8S-8P HEFSM are chosen for optimization analysis. The combination of 8S-8P inner-rotor HEFSM have best performance with 284Nm maximum torque, 62.98kW maximum power and 90% efficiency. Then 8S-8P HEFSM have been compared with three-phase 12S-14P HEFSM in term of copper loss, weight and efficiency. As conclusion, the final design machine produce 12.45% less copper loss, 8.88% less weight and with almost similar efficiency compared to three-phase configuration

Asas Keusahawanan (ETR 300) : Arnafa Circuit Enterprise)/ Nazrul Zambri Md. Yusof... [et al.]

Arnafa Circuit Enterprise menyediakan perkhidmatan penyewaan sukan Go-Kart beralamat di Lot 10, Kawasan Perumahan Mergong Fasa 3, 05150 Alor Setar, Kedah. Mereka menyediakan perkhidmatan seperti penyewaan Go-Kart untuk aktiviti sukan lumba kereta bermotor dengan bayaran yang berpatutan, penyewaan Go-Kart untuk kelab-kelab tertentu sebagai menyambut hari ulangtahun syarikat mereka. Pasaran permagaan ini tertumpu kepada anak tempatan dari seluruh utara amnya yang berumur dalam lingkungan 15 - 45 tahun serta pelancong asing yang datang melawat negeri Kedah Darul Aman. Ia juga berdasarkan keadaan ekonomi semasa negara

The effect of Piper betle on wound healing in male Sprague Dawley rats

Piper betle (PB) leaves have been traditionally used in many Asian countries for the healing of wounds and other ailments. The aim of this study was to examine the wound healing effect of PB on skin injury-inflicted Sprague-Dawley rats. Eighteen male Sprague-Dawley rats were inflicted with wounds and then divided into three groups consisting of a control (normal wound healing without dressing), saline (wound healing aided by gauze soaked in saline) and PB (gauze impregnated with PB paste) dressings. Wounds were created on the back of rats with 6-mm sterilized punch biopsy needle. Wounds were examined on days 3, 5, 7, 9, 11 and 13 for dryness, exudation, and scar formation. Rats were sacrificed on day 14 and the granulation tissue formed on the wound was then excised for histological examination using Hematoxylin and Eosin staining. The formation of granulation tissue in rats treated with PB showed higher progress to wound closure with shorter days (on day 3) compared to the control and saline group (on day 5). PB dressing minimized the formation of scar tissue significantly (p<0.05) compared to the control and saline groups. In conclusion, our results suggest that PB has good wound healing effect with less scarring and perhaps it can be used to treat wound complementary to the present method