Segmented phase of ultraviolet (UV) curable thermoset polyurethanes-graphite (TPU-G) composites

Segmented thermoset polymeric materials properties mainly classified through its carbonyl hydrogen bonding. The addition of graphite particle loading in polymeric materials tailored the functional characteristic of the composites. Therefore, the carbonyl hydrogen bonding in the hard segments of the synthesized segmented ultraviolet (UV) curable thermoset polyurethanes-graphite (TPU-G) composites was identified. This composites based green polymer incorporated with varying graphite particles loading were prepared through slip casting method which cure upon UV light. These result in an enhancement of the carbonyl hydrogen bonding which tribute to degree of phase separation (DPS %) in the TPU-G composites ranged from 10-20%, as compared to that in the pure TPU. In addition, the spectroscopy detects the formation of carbonyl hydrogen groups within the TPU-G composites although they are prone to chain scission and undergo photo oxidation subjected to ultraviolet (UV) curing. Upon UV curing, higher graphite weight loading (TPU-G20, TPU-G25 and TPU-G30 composites), shows higher and stable DPS% value, attribute to soft segment- soft segment and hard segment- hard segment establishment. Therefore, the graphite particles dominantly absorb the incident radiation instead of thermoset polyurethane without changing its based

Availability analysis of terrestrial free space optical (FSO) link using visibility data measured in tropical region

Haze and rain are the most impairments factors to free space optical (FSO) links. These weather conditions limit the visibility, and thereby causes high attenuation of the optical signal. This high attenuation reduces the availability performance of the FSO link. This study evaluates the performance of a terrestrial FSO link under tropical climate conditions. The performance analysis is evaluate over 5 km link distance. The cumulative distribution function (CDF) of the received signal to noise ratio (SNR) is used to study the outage performance of the FSO link under haze conditions. The performance analysis is based on three years measured visibility data in Malaysia. Based on the statistical analysis, link availability of 99.99% can be achieved for 37.44 dB SNR over 1 km link distance. Carrier class availability “five nine” can be achieved for 20 dBm transmission power using 1550 nm wavelength

A Carrierless Amplitude Phase (CAP) Modulation Format: Perspective and Prospect in Optical Transmission System

The explosive demand of broadband services nowadays requires data communication systems to have intensive capacity which subsequently increases the need for higher data rate as well. Although implementation of multiple wavelengths channels can be used (e.g. 4 × 25.8 Gb/s for 100 Gb/s connection) for such desired system, it usually leads to cost increment issue which is caused by employment of multiple optical components. Therefore, implementation of advanced modulation format using a single wavelength channel has become a preference to increase spectral efficiency by increasing the data rate for a given transmission system bandwidth. Conventional advanced modulation format however, involves a degree of complexity and costly transmission system. Hence, carrierless amplitude phase (CAP) modulation format has emerged as a promising advanced modulation format candidate due to spectral efficiency improvement ability with reduction of optical transceiver complexity and cost. The intriguing properties of CAP modulation format are reviewed as an attractive prospect in optical transmission system applications

Management of Constipation

Constipation is the most ignored complaint by doctors and unfortunately, it requires urgent management due to the decreased quality of life. Most cases are functional constipation but there is also a great number of constipation due to organic abnormalities. In an attempt to manage the patient properly, we should put our emphasis on excellent knowledge of pathophysiology of constipation.By using the colonic transit time test, we could determine the type of constipation, which would have an effect on therapy. In most cases, constipation has a good response to high fiber diet and additional laxative medication and surgical therapy is seldom required unless complications have occurred. There is also a suggestion for preventing constipation may be caused by opioid USAge

Botanical Composition and Carrying Capacity in Various Agroecosystems on The Timor Island

This research aims to know the type of vegetation, nutrient components of feed and carrying capacity based on agroecosystems on Timor Island conducted from January-March 2018 (transition from the rainy season to the dry season). The research location was chosen purposively so that those it represented the pasture were in the District of Belu, Malaka, and TTU; agriculture in the District of Kupang and Kota Kupang; plantation in Kupang District; and forests in TTS District. Forage samples were taken using the 1x1m2 quadrant method. The quadrant is thrown at random. All vegetation in the quadrant is cut and analyzed in the laboratory. Descriptive data analysis. The result is that the main vegetation types of Bali cattle consumption in pasture agroecosystems is natural grass with a nutrient composition of ash (9.9%), CP (5.7%), CF (38.5%), EE (2.2%), NFE (36.4%) and TDN (42.1%). Agriculture agroecosystem is ricestraw with a nutrient composition of ash (9.6%), CP (5.8%), CF (27.6%), EE (2.1%), NFE (48.8% ) and TDN (52.8%). Plantation agroecosystems is lamtoro with a nutrient composition of ash (13.6%), CP (12.0%), CF (20.4%), EE (3.3%), NFE (42.8%) and TDN (54.9%). Forest agroecosystems is kabesak with a nutrient composition of ash (8.6%), CP (11.5%), CF (26.9%), EE (1.2%), NFE (44.2%) and TDN (53.1%). The carrying capacity of pasture, agriculture, plantation and forest in sequence are very high, namely 4.8 UT and CCI 0.4 with an average body weight of 229.3 kg; 5.6 UT and CCI 0.6 with an average BB of 188 kg; 6.8 UT and CCI 0.7 with an average BB of 227.5 kg; and 5.8 UT and CCI 0.7 with an average BB of 194.9 kg. The entire agroecosystem area on Timor Island is classified as a very critical area

Visible light communication using new Flip-FBMC modulation system technique

Filter bank multi-carrier (FBMC) modulation in the visible light communication (VLC) system is one of the most promising modulation systems in optical wireless communications (OWC), especially in 5G and 6G future applications. FBMC has a wide bandwidth compared to other modulation systems. One of the highest degree essential conditions for utilising the signal in VLC is that the signal is real positive, the signal is agreeable with intensity modulation/direct detection (IM/DD), where Hermitian symmetry (H.S) is utilised to get a real signal (RE) and to be unipolar direct current (DC)-bias is used. Here the challenge arises as this method increases complicating, due to the modulation of the N number of frequency symbols, these symbols need 2N inverse fast fourier transform (IFFT) and fast fourier transform (FFT), in addition to energy consumption. This research focused on the time domain and not the frequency domain by using the traditional complex FBMC generation signal, and to obtain the RE signal by placing the RE signal side by side with the imaginary signal (IMs) in a row, and then using new Flip-FBMC technology, which saves more energy. The proposed technologies provide approximately 57% of the number of IFFT/FFT. The use of Flip-FBMC technology consumes less energy than traditional technologies with better bit error rate (BER) performance

Low complexity DCO-FBMC visible light communication system

Filter Bank Multicarrier (FBMC) is a new waveform candidate in the visible light communication system (VLC). FBMC is a distinctive kind of multi-carrier modulation that can be regarded as an alternative to orthogonal frequency Division Multicarrier (OFDM) with CP (cyclic prefix). DCO-FBMC (DC-bias optical FBMC) has recently been used in VLC, because it overcomes all defects in the optical-OFDM system and has high spectral efficiency. but at the same time the traditional DCO-FBMC suffers from high complexity due to the use of Hermitian Symmetry for real signal, by using 2N-point subcarrier IFFT (Inverse Fast Fourier Transformer) in the modulator, and the output is N-point subcarrier FFT (Fast Fourier Transform) in the demodulator. In this paper, for the first time, the possibility of minimizing complexity and generating a real signal without the use of Hermitian Symmetry or any other technique has been verified. The proposed technology provides 50% of the size of the IFFT / FFT and this results in a significant reduction in power consumption and occupied chip area

Effect of Polystyrene Latex Addition on Size and Pore Volume of Porous Calcium Oxide Particles Prepared by Spray-Pyrolysis Method and Its Ability for SO2 Retention

In this study, the effects of polystyrene (PS) latex addition on the particle morphology and the pore content of calcium oxide (CaO) were investigated. The CaO particles were prepared using an ultrasonic nebulizer-assisted spray-pyrolysis method with variation of the PS/Ca(NO3)2·4H2O mass ratio in the precursor. Good crystallinity of CaO was obtained at 825°C of synthesis temperature under 2 l/min of nitrogen gas flow, which was confirmed by Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). According to scanning electron microscope (SEM) characterization, the CaO particles synthesized with 0 and 25 wt% PS addition had an almost spherical shape with an average size of 1.58 and 1.48 µm, respectively. In addition, macropores were formed in the CaO particles prepared with 25 wt% PS addition that had an average pore diameter of 583.26 nm. Meanwhile, the CaO particles prepared with 75 wt% PS addition had a random shape and an average size of 1.41 µm. The mesopore content was investigated by Barret-Joyner-Halenda (BJH) analysis, which showed improvement of the pore size from 3.45 nm to 5.42 nm for 0 and 25 wt% PS addition, respectively, which is proportional to the pore volume, pore surface area, and the capacity of SO2 retention