Study of Obstacles Effect on Mobile Network and WLAN Signal Strength

In the era of continuous advancement in wireless technologies, path loss, also known as channel attenuation, is a drop in signal strength from the transmitter to the receiver. Path loss modelling is critical in designing fixed and mobile communication systems for various applications. This paper focuses on the received power (dBm) and free space path loss (FSPL) on various distances and frequencies such as 5240 MHz for wireless local area network (WLAN) and frequency such as 2100 MHz for the mobile network such as Celcom. As a result, able to analyze the correspondence between received power (dBm) and distance of each related frequency and the correspondence between FSPL (dB) and distance of each corresponding frequency and able to analyze the effect of obstacle on received power (dBm) and frequency

Investigate Bending Effect of Wearable GPS Patch Antenna with Denim and Polyester Fabric Substrate

In high technologies today, wearable devices have become popular. Wearable technology is a body sensing system that supports application of health observance and tracking through a wearable Global Positioning System (GPS). The design of the patch antennas is highly significant for the brilliance of the wearable patch antennas. This paper focuses on analyzing the bending effect on return loss and frequency between three types of GPS patch antenna. Types of GPS patch antennas that have been designed in this project are with different substrates and different designs. The wearable patch antenna has been designed and analyse using CST software. As a result, able to analysis the reflection coefficient (S11), radiation patterns, and analytical approach for patch antenna bending effect were obtaine

S-band five-port ring reflectometer-probe system for in vitro breast tumor detection

A five-port ring reflectometer-probe system was developed to measure relative permittivity of normal and tumorous breast tissues in frequency range from 1.6 to 2.75 GHz. The calibration procedures of the study reflectometer and the coaxial probe were described in detail. In this study, the synthetic breast tissues have been used, which are the Triton TX-100-water mixture at different ratios that mimic dielectric properties of normal and tumor breast tissue samples. The comparative studies of reflection coefficient and dielectric properties of the synthetic mixture samples were conducted using study reflectometer-probe system and commercial vector network analyzer with Keysight (formerly Agilent) 85070E dielectric probe. Maximum mean errors of the linear magnitude, phase, dielectric, and loss factor measurements were recorded to be 0.02, 6.1°, 2.21, and 1.60, respectively. These measurements were significantly distinguishable for normal and tumorous breast tissues

A Study of the Anechoic Performance of Rice Husk-Based, Geometrically Tapered, Hollow Absorbers

Although solid, geometrically tapered microwave absorbers are preferred due to their better performance, they are bulky and must have a thickness on the order of λ or more. The goal of this study was to design lightweight absorbers that can reduce the electromagnetic reflections to less than −10 dB. We used a very simple approach; two waste materials, that is, rice husks and tire dust in powder form, were used to fabricate two independent samples. We measured and used their dielectric properties to determine and compare the propagation constants and quarter-wave thickness. The quarter-wave thickness for the tire dust was 3 mm less than that of the rice husk material, but we preferred the rice-husk material. This preference was based on the fact that our goal was to achieve minimum backward reflections, and the rice-husk material, with its low dielectric constant, high loss factor, large attenuation per unit length, and ease of fabrication, provided a better opportunity to achieve that goal. The performance of the absorbers was found to be better (lower) than −20 dB, and comparison of the results proved that the hollow design with 58% less weight was a good alternative to the use of solid absorbers

Monitoring moisture content for various kind of tea leaves in drying processes using rf reflectometer-sensor system

This paper presents tea leaves moisture monitoring system based on RF reflectometry techniques. The system was divided into two parts which are the sensor and reflectometer parts. The large coaxial probe was used as a sensor for the system. The reflectometer part plays a role as signal generator and also data acquisition. The reflectometer-sensor system was operated with a graphical user interface at 1.529 GHz at room temperature. The system was able to measure the moisture content of tea leaves ranging 0% m.c to 50% m.c on a wet basis. In this study, up to five kinds of tea leaves bulk were tested. The mean of absolute errors in the moisture measurement for tea leaves was ±2

Single layer microwave absorber based on rice husk-mwcnts composites

In this paper, rice husk (RH) and multi-walled carbon nanotubes (MWCNTs) composite have been fabricated as single layer microwave absorber. The MWCNTs with various weight ratio composites with RH have been prepared. Three different weight ratio 3 wt% MWCNTs, 5 wt% MWCNTs, and 15 wt% MWCNTs of the RH-CNTs have been designed and fabricated. Moreover, the dielectric properties of different RH-CNTs specimens have been verified by using rectangular waveguide transmission line technique. Furthermore, the microwave absorption of these RH-CNTs has been analyzed using free space measurement and CST Microwave Studio (CST-MWS). The dielectric properties and microwave absorption of different RH-CNTs were investigated in 8.2-12.4 GHz (X-band). From the measurement, the dielectric properties parameter of RH-CNTs is analyzed. The dielectric constant and loss factor of the RH-CNTs composite increases with increasing of MWCNTs weight ratio. However, the magnetic properties of RH-CNTs remain constant, ur= 1-j0. The measurement and simulation result show that such RH-CNTs composites has excellent microwave absorption up to 33 dB in a certain frequency rang

A triangular MIMO array antenna with a double negative metamaterial superstrate to enhance bandwidth and gain

Multiple-input-multiple-output (MIMO) array antenna integrated with the double negative metamaterial superstrate is presented. The triangular metamaterial unit cell is designed by combining two triangular elements positioned in complementary on the same plane at different sizes. Such design with more gaps is used to excite rooms for more capacitance effects to shift the resonance frequency thus enlarging the bandwidth of the MIMO antenna. The unit cell is arranged in 7 × 7 periodic array created a superstrate metamaterial plane where the Cstray exists in parallel between the two consecutive cells. It is found that the existence of Cstray and gaps for each unit cells significantly influenced the bandwidth of the MIMO antenna. The higher value of the capacitance will lead to the negativity of permittivity. The superstrate plane is then located on top of the 4 × 2 MIMO with a gap of 5 mm. The integration resulted in improving the bandwidth to 12.45% (5.65-6.4GHz) compared to only 3.49% bandwidth (5.91-6.12GHz) of the MIMO antenna itself. Moreover, the negative permeability characteristic is created by a strong magnetic field between the complementary unit cells to have 14.05-dBi peak gain. Besides that, the proposed antenna managed to minimize the mutual coupling and improve the mean effective gain, envelope correlation coefficient, and multiplexing efficiency

Heterologous expression of cytotoxic sesquiterpenoids from the medicinal mushroom Lignosus rhinocerotis in yeast

Background: Genome mining facilitated by heterologous systems is an emerging approach to access the chemical diversity encoded in basidiomycete genomes. In this study, three sesquiterpene synthase genes, GME3634, GME3638, and GME9210, which were highly expressed in the sclerotium of the medicinal mushroom Lignosus rhinocerotis, were cloned and heterologously expressed in a yeast system. Results: Metabolite profile analysis of the yeast culture extracts by GC-MS showed the production of several sesquiterpene alcohols (C 15 H 26 O), including cadinols and germacrene D-4-ol as major products. Other detected sesquiterpenes include selina-6-en-4-ol, ß-elemene, ß-cubebene, and cedrene. Two purified major compounds namely (+)-torreyol and a-cadinol synthesised by GME3638 and GME3634 respectively, are stereoisomers and their chemical structures were confirmed by 1 H and 13 C NMR. Phylogenetic analysis revealed that GME3638 and GME3634 are a pair of orthologues, and are grouped together with terpene synthases that synthesise cadinenes and related sesquiterpenes. (+)-Torreyol and a-cadinol were tested against a panel of human cancer cell lines and the latter was found to exhibit selective potent cytotoxicity in breast adenocarcinoma cells (MCF7) with IC 50 value of 3.5 ± 0.58 µg/ml while a-cadinol is less active (IC 50 = 18.0 ± 3.27 µg/ml). Conclusions: This demonstrates that yeast-based genome mining, guided by transcriptomics, is a promising approach for uncovering bioactive compounds from medicinal mushrooms

Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples

Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts

From classical to deep learning: review on cartilage and bone segmentation techniques in knee osteoarthritis research

Knee osteoarthritis is a major diarthrodial joint disorder with profound global socioeconomic impact. Diagnostic imaging using magnetic resonance image can produce morphometric biomarkers to investigate the epidemiology of knee osteoarthritis in clinical trials, which is critical to attain early detection and develop effective regenerative treatment/therapy. With tremendous increase in image data size, manual segmentation as the standard practice becomes largely unsuitable. This review aims to provide an in-depth insight about a broad collection of classical and deep learning segmentation techniques used in knee osteoarthritis research. Specifically, this is the first review that covers both bone and cartilage segmentation models in recognition that knee osteoarthritis is a “whole joint” disease, as well as highlights on diagnostic values of deep learning in emerging knee osteoarthritis research. Besides, we have collected useful deep learning reviews to serve as source of reference to ease future development of deep learning models in this field. Lastly, we highlight on the diagnostic value of deep learning as key future computer-aided diagnosis applications to conclude this review