Mountain-Shaped Coupler for Ultra Wideband Applications

This paper demonstrates a novel mountain-shaped design for a compact 3-dB coupler operating at ultra-wideband (UWB) frequencies from 3.1GHz to 10.6 GHz. The proposed design was accomplished using multilayer technology in which the structure is formed by three layers of conductors interleaved by a layer of substrate between each conductor layer. Simulation was carried out using CST Microwave Studio; the result was then compared with results from rectangular and star-shaped couplers that implemented the same technique. The results obtained show that the proposed new coupler has better performance compared to both rectangular and star-shaped coupler designs in terms of return loss, isolation, and phase difference. The coupler was fabricated and measured; the measurement results satisfactorily agree with the simulation results

Compact wideband broadside-coupled microstrip-slot bandpass filter for communication applications

This paper proposes a compact size design of wideband bandpass filter (BPF). The broad-side coupling microstrip-slot technique is used to accomplish a good passband response with very low insertion loss across a wideband frequency range. The BPF that is designed using Rogers RO4003C substrate shows a good performance with the respective maximum reflection coefficient and insertion loss of -10 dB and 1.2 dB between 0.92 GHz and 5 GHz. This type of BPF filter is useful in any communication applications

Antioxidant properties of rice bran oil from different varieties extracted by solvent extraction methods

Antioxidant properties of rice bran oil from different rice bran varieties; Rice Bran-Bario (RB-Bario), Rice bran-Lowland (RB-Low) and Rice Bran- Upland rice (RB-Up), collected from different cultural plots, were assessed. Measurement of antioxidant properties was evaluated by TPC (total phenolic content), DPPH scavenging activities and reducing power of extracts.. The study shows that antioxidant efficacy of rice bran was found the highest in RB-Up, followed by RB- Low and RB-Bario. The antioxidant properties were related to the rice bran origin and water irrigation demand by particular variety. RB –Up has a unique plantation condition which takes least amount of water retention which contribute to the highest antioxidant activity. Extraction solvents used shows that Upland (16.15%) and Lowland (16.16%) yielded the highest amount in conserving the crude fat oil in rice bran extract compared to Bario

Characterization of cocoa butter equivalent from formulated hard palm oil mid-fraction and canola oil blend

A search for an alternative to cocoa butter (CB) has increased due to premium price, uncertainty in supply and variability in quality problems. The study to find cocoa butter equivalent (CBE) as an alternative to CB from available and high nutritional oils or fats was carried out using enzymatic interesterification method. The objective of this study was to characterize the CBE obtained from hard palm oil mid-fraction (PMF) and canola oil blend using immobilized lipase from Rhizomucor miehei. The experiment was performed at hard PMF concentration of 50%, lipase load of 7.2% (based on weight of substrate) and reaction time of 2 hours. The characteristics observed were fatty acid profiles, triacylglycerol (TAG) composition, slip melting point (SMP) and solid fat content (SFC). CBE obtained exhibit higher percentage of linoleic acid (omega 6, 7.98%) and linolenic acid (omega 3, 2.47%) than CB (3.40% of linoleic acid) due to the addition of canola oil. TAG composition was 28.65% of palmitic-oleic-palmitic (POP), 19.52% of palmitic-oleic-stearic (POS), and 3.57% of stearic-oleic-stearic (SOS). SMP value of CBE (46.25°C) was higher than CB (32-35°C). The SFC value of CBE was different to CB. It was due to high amount of POP TAG, free fatty acid (FFA) or saturated saturated saturated (StStSt) TAGs in CBE produced and also lack amount of TAGs which has oleic acid at sn 2 position

Effect of Interphase Region and Neighboring Particles on Electric Field Intensity within Nanocomposite Systems

Recent works show that the presence of the interphase surrounding nanoparticles can improve the dielectric properties of nanocomposites. Also, neighboring particles in the nanocomposites affect the electric field distribution. Therefore, the objective of this paper to model and analyze the effect of onedimensional (1D) nanofillers towards the electric field distribution when the interphase and neighboring are taken into account inside the nanocomposite system. By using Finite Element Method Magnetics (FEMM) 4.2 software, a model of nanocomposites system consists of polymer matrix, nanoparticle filler with interphase and neighboring particles is modeled under the electrostatic problem module. Electric field intensity is observed with different distance between adjacent nanoparticles and interphase region permittivity values. The result obtained show that the presence of the interphase with various permittivity value will result in distorted electric field intensity surrounding a nanoparticle. Furthermore, the electric field intensity also affected when adjacent nanoparticles displaced between each other within nanocomposites

Investigation of Unequal Planar Wireless Electricity Device for Efficient Wireless Power Transfer

This article focuses on the design and investigation of a pair of unequally sized wireless electricity (Witricity) devices that are equipped with integrated planar coil strips. The proposed pair of devices consists of two different square-shaped resonator sizes of 120 mm × 120 mm and 80 mm × 80 mm, acting as a transmitter and receiver, respectively. The devices are designed, simulated and optimized using the CST Microwave Studio software prior to being fabricated and verified using a vector network analyzer (VNA). The surface current results of the coupled devices indicate a good current density at 10 mm to 30 mm distance range. This good current density demonstrates that the coupled devices’ surface has more electric current per unit area, which leads to a good performance up to 30 mm range. Hence, the results also reveal good coupling efficiency between the coupled devices, which is approximately 54.5% at up to a 30 mm distance, with both devices axially aligned. In addition, a coupling efficiency of 50% is achieved when a maximum lateral misalignment (LM) of 10 mm, and a varied angular misalignment (AM) from 0° to 40° are implemented to the proposed device

Optimization of sweet potato pectin extraction using hydrochloric acid

Pectin has been used widely as thickener, stabilizer and gelling agent. However, the sources of pectin industrially are still limited. This study aims to optimize the extraction of pectin from sweet potato residue using hydrochloric acid. In this study, proximate analysis of the sweet potato residues were performed and the extraction of pectin from sweet potato residues using hydrochloric acid was optimized to maximize its yield using response surface methodology (RSM). Three parameters were manipulated and optimized which were temperature (°C), pH and extraction time (min). The extracted pectin was further analyzed for its degree of esterification (DE) using Fourier Transform Infrared Spectroscopy (FTIR). The sweet potato residue sample obtained moisture content of 79.7±1.7%, ash content of 1.08±0.09% and carbohydrate content of 34.3±2.7%. The optimum condition to extract pectin from sweet potato residues using hydrochloric acid was at extraction temperature 60 °C, pH 1 and extraction time 60 min with 23.48 % pectin yield. The pectin has 57.48% of DE which indicates high methoxyl pectin. The results show that hydrochloric acid can be used as one of the solvents to extract pectin from sweet potato

Integrated Open Loop Resonator Filter Designed with Notch Patch Antenna for Microwave Applications

This paper presented the design of integrated open loop resonator bandpass filter with notch type antenna for the use in microwave applications. Chebyshev type filter is selected as the filter characteristics and cascaded design with the antenna to produce a single module, Integrated Filter Antenna (IFA). Special feature of the antenna is the implementation of notch on the patch antenna to improve the efficiency. IFA is then simulated in electromagnetic simulation tool, Agilent Advance Design System (ADS) version 2016 and measured using R&S Vector Network Analyzer. It shows that the proposed IFA produced good measured return loss >-30dB with both vertical and horizontal gain of 9.11dBi and 8.01dBi respectively