Effects of tides on the hydrology and geometry of a freshwater channel

The situation of Sungai Sengkuang becomes worse because it is under tidal influence. Flood was reduced after removing the temporary culvert. Analysis is carried out for the existing system to investigate whether it is still able to accommodate the volume of water comprises the discharge from upstream and high tide from downstream. The computer program such as HEC-HMS 2.2.2 will be used to carry out the Hydrologic Model Calibration. By using HEC-RAS, Hydraulic Model Calibration will be carried out for the channel. The discharge with different ARI will be used as the upstream boundary condition during the flow analysis. Frequency analysis for the tide level which is collected from JUPEM. The tide level with different ARI is used as the downstream boundary condition. From the Energy Grade Line of the channel, which energy is dominant, the energy from downstream or the energy from upstream.Keywords: tidal influence; dominant energy; flow analysis; hydraulic and hydrology model analysi

The comparison of dual wavelength fiber laser spectrum in SMF and HNLF by utilizing laser diode

A dual-wavelength erbium-doped fiber (EDF) fiber ring laser in single mode fiber and highly nonlinear fiber is demonstrated and both optical spectrums are compared at 400 mA of Laser Diode (LD) output. The fiber ring laser cavity incorporated sagnac loop had been applied for the laser to lase two wavelengths simultaneously due to high birefringent in polarizaton-maintaining fiber (PMF). Experimental results show that, owing to the contributions of two degenerate fourwave mixings (FWM) in the HNLF and the dual-wavelength proposed fiber laser is quite stable with small fluctuation power in 1.93 dB within 24 minutes in HNLF

Short term durability of steel-strap confined concrete

Steel strapping tensioning technique (SSTT) confinement has been proven as a type of external confinement to retrofit and upgrade concrete structures. Their remarkable enhancement to concrete mechanical properties, practicing active lateral confinement, low cost, easy to operate, time saving and no structure interruption during application have brought this technique as of the most affordable technique for column confinement, especially for high strength concrete (HSC) which naturally behaves insufficient in ductility. Although a great number of previous studies have demonstrated the performance of SSTT confinement, there are several anxieties related to the long term behaviour of SSTT confined columns which have yet been implemented especially in real hostile condition. Environmental effects, such as ultraviolet radiation exposure and saline solution (sea water) may affect the confining material properties, and therefore decrease the performance of the confined columns. In this study a total of twenty HSC specimens with dimension of 100 mm and 200 mm in diameter and height respectively were prepared, volumetric-identically pre-tensioned with steel strap and exposed to three conditions: indoor, outdoor and saline water for three months. The exposed specimens were monotonically tested and their performance was studied through the stress-strain relationship, mode of failure and degree of corrosion. The results show that none of the forenamed environmental conditions have exaggerating influence on the performance of the SSTT confined concrete specimens even some material has been severely corroded. It is then parallel compared with existing FRP confinement studies and the result proves that SSTT confinement able to possess the highest strength performance under similar environmental exposure

Passively mode-locked laser using an entirely centred erbium-doped fiber

This paper describes the setup and experimental results for an entirely centred erbium-doped fiber laser with passively mode-locked output. The gain medium of the ring laser cavity configuration comprises a 3 m length of two-core optical fiber, wherein an undoped outer core region of 9.38 μm diameter surrounds a 4.00 μm diameter central core region doped with erbium ions at 400 ppm concentration. The generated stable soliton mode-locking output has a central wavelength of 1533 nm and pulses that yield an average output power of 0.33 mW with a pulse energy of 31.8 pJ. The pulse duration is 0.7 ps and the measured output repetition rate of 10.37 MHz corresponds to a 96.4 ns pulse spacing in the pulse train

Prediksi Kedatangan Turis Asing Ke Indonesia Menggunakan Backpropagation Neural Networks

In this paper, a backpropagation neural network (BPNN) method with time series data have been explored. The BPNN method to predict the foreign tourist's arrival to Indonesia datasets have been implemented. The foreign tourist's arrival datasets were taken from the center agency on statistics (BPS) Indonesia. The experimental results showed that the BPNN method with two hidden layers were able to forecast foreign tourist's arrival to Indonesia. Where, the mean square error (MSE) as forecasting accuracy has been indicated. In this study, the BPNN method is able and recommended to be alternative methods for predicting time series datasets. Also, the BPNN method showed that effective and easy to use. In other words, BPNN method is capable to producing good value of forecasting.Keywords - BPNN; foreign tourists; BPS; MSEPemanfaatan backpropagation neural network (BPNN) dengan data deret waktu telah digunakan dalam paper ini. Metode BPNN telah digunakan untuk memprediksi data kedatangan turis asing ke Indonesia, dimana data turis tersebut diambil dari badan pusat statistik Indonesia (BPS). Hasil pengujian menunjukkan bahwa metode BPNN dengan dua lapisan tersembunyi mampu memodelkan dan meramalkan data kedatangan turis asing ke Indonesia yang diindikasikan dengan nilai mean square error (MSE). Penelitian ini merekomendasikan bahwa metode BPNN mampu menjadi alternative metode dalam memprediksi data yang berjenis deret waktu karena metode BPNN efektif dan lebih mudah digunakan serta mampu menghasilkan akurasi nilai peramalan yang baik

Characteristics of Mineral Oil-based Nanofluids for Power Transformer Application

Trends in the field of nanomaterial-based transformer oil show most of the conducted works have focused only on the transformer oil-based nanofluids but limited studies on the stability of transformer oil-based nanofluids. Since mineral oil-based nanofluids still can produce the sedimentation, thus the cold-atmospheric pressure plasma method is proposed to functionally modify the Silicon Dioxide (SiO2) nanofiller in order to enhance the electrical properties of the mineral oil-based nanofluids. The AC breakdown strength oil samples before and after modification were measured. It was found that the plasma treated nanofluids have higher AC breakdown voltage compared to pure oil and untreated nanofluids. Also, Fourier Transform Infrared (FTIR) Spectroscopy has been used in this study to analyse the physical changes of oil samples. It is envisaged that the added silica nanofiller has significant effect on electrical properties of the transformer oil-based nanofluids which would enable to the development of an improved class of liquid dielectric for the application of power transformer

A sensitive acoustic sensor using fiber bragg grating based on strain compensation

An acoustic sensitivity single ring fiber sensor with enhanced pressure sensitivity is designed by using Fiber Bragg Grating (FBG). Measurement sensitivity of the this fiber sensor is 0.3714 με/Hz. This sensor exhibited a good acoustic sensitivity, showing that the sensor has good sensing properties for the detection of the acoustic signals