Analysis of Concentric Split Ring Square Element for Broadband Reflectarray Antenna

An investigation of phase variation and phase range of concentric split ring square element for broadband reflectarray antenna is presented in this paper. This is realized by exploiting the physical geometry of three element shapes namely square element, concentric ring square element and concentric split ring square element. Modifying the current distribution of basic concentric ring square element, leads to a less steep phase variation and also the bandwidth performance. An analysis of frequency response is described and analysed. The physical interpretation of the elements is also discussed. The proposed antenna element effectively covers two frequency operations (13.44 GHz and 18.36 GHz) in Ku-band range. Bandwidth broadening is achieved by introducing the ring square combination of element and the practical phase range is achieved through the use of RF 35 (thickness = 1.524 mm) as the substrate. The new concept of split initiates to a wider bandwidth (up to 67.6 %) for the antenna and can applied to any two frequency operations of Ku-band applications

A Comparative Study of Enhanced Nonlinear PI to Multivariable Nonlinear Plant

The static gains of PI controller have limitation to handle the process nonlinearities of the system. This suggests the development of enhanced nonlinear PI controller where a nonlinear gain function is cascaded to PI parameters. Two nonlinear gain functions are developed and the effectiveness of the control performance is investigated for two different control structures for a multivariable nonlinear wastewater treatment plant (WWTP). It was proved that superior output with the lower mean error was obtained by developed nonlinear PI specifically in the multivariable control structure. The developed nonlinear PI offers simpler control structure and easy implementation hence offering alternative control strategy for the multivariable system

Does Inhalation of Virgin Coconut Oil Accelerate Reversal of Airway Remodelling in an Allergic Model of Asthma?

Many studies have been done to evaluate the effect of various natural products in controlling asthma symptoms. Virgin coconut oil (VCO) is known to contain active compounds that have beneficial effects on human health and diseases.The objective of this study was to evaluate the effect of VCO inhalation on airway remodelling in a rabbit model of allergic asthma.The effects of VCO inhalation on infiltration of airway inflammatory cells, airway structures, goblet cell hyperplasia, and cell proliferation following ovalbumin induction were evaluated. Allergic asthma was induced by a combination of ovalbumin and alum injection and/or followed by ovalbumin inhalation.The effect ofVCOinhalationwas then evaluated via the rescue or the preventive route. Percentage of inflammatory cells infiltration, thickness of epithelium and mucosa regions, and the numbers of goblet and proliferative cells were reduced in the rescue group but not in preventive group. Analysis using a gas chromatography-mass spectrometry found that lauric acid and capric acid were among themost abundant fatty acids present in the sample. Significant improvement was observed in rescue route in alleviating the asthma symptoms, which indicates the VCO was able to relieve asthma-related symptoms more than preventing the onset of asthma

The design of IPT system for multiple kitchen appliances using class E LCCL circuit

Since many years ago, kitchen appliances are powered up by cable connected. This create a troublesome case as wire might tangle together and cause kitchen table messy. Due to this, wireless power technology (WPT) is introduced as its ability is to transmit power to load without physical contact. This leads to cordless solution better in safety as the product can be completely seal, highly expandable power range. This work focuses on the design of WPT based on inductive approach to power up multiple kitchen appliances. The selection of inductive approach over its partners capacitive and acoustic is mainly due to high power efficiency. Class E inverter is proposed here to convert the DC to AC current to drive the inductive link. A 1 MHz operating frequency is used. To ensure the circuit is robust with load variations, an LCCL impedance matching is proposed. This solution is table to maintain the output power if there is a slight change in load impedance. Finally, the developed prototype is able to supply 50V utput which can achieve power transmission up to 81.76%

A parametric study of textile artificial magnetic conductor with wire dipole at 2.45GHZ and 5.8GHZ

Textile Artificial Magnetic Conductor (AMC) with wire dipole is presented. The AMCs are made of fleece and Shieldit fabrics and were designed to have in-phase reflections at 2.45GHz and 5.8GHz. Thorough parametric studies based on AMC unit cell have been performed to obtain the optimized design. Performance comparison between different types of environments, fabrics and arrays size were also conducted. The proposed AMC and wire dipole are designed, simulated, fabricated and tested. Results of return loss, radiation pattern and gain are presented. Results show that forward directive radiation pattern with improved gain are achieved with the introduction of the AMC at both 2.45GHz and 5.8GHz. The proposed textile AMC is suitable for body centric communication systems

Study of genetic variation of some eggplant cultivars through RAPD-PCR molecular markers and its relatedness to phomopsis blight disease reaction

Disease susceptibility and genetic variability in 10 eggplant genotypes were studied after inoculating Phomopsis vexans under confined field conditions. Random amplified polymorphic DNA (RAPD) markers were used to assess genetic variation and relationships among eggplant genotypes. The disease index of leaves ranged 0.208-13.79%, while fruit infection ranged 2.15-42.76%. Two varieties, Dohazari G and Laffa S, were found to be susceptible, 6 were moderately resistant, 1 was moderately susceptible, and BAU Begun-1 was resistant to P. vexans. Amplification of genomic DNA by using 3 RAPD primers produced 20 bands: 14 (70%) were polymorphic and 6 (30%) were monomorphic. The highest intra-variety similarity indices values were found in ISD 006, Ishurdi L, Jessore L, and BAU Begun-1 (100%), while the lowest was in Dohazari G (90%). The lowest genetic distance (0.0513) and the highest genetic identity (0.9500) were observed between the ISD 006 and Ishurdi L combinations. A comparatively higher genetic distance (0.3724) and the lowest genetic identity (0.6891) were observed between the ISD 006 and Dohazari G combinations. A dendogram was constructed based on Nei’s genetic distance, which produced 2 main clusters of the genotypes - Cluster I: ISD 006, Ishurdi L, Marich begun L, BAU Begun-1, Marich begun S, and Chega and Cluster 2: Laffa S, Dohazari G, Jessore L, and Singhnath. Genetic variation and its relationship with disease susceptibility were assessed using RAPD markers, to develop disease-resistant varieties and improve eggplant crops

Flood risk assessment: a review of flood damage estimation model for Malaysia

Flood damage assessment is important in flood risk management for the assessment of flood vulnerability, development of flood risk map and flood management financial appraisal. In Malaysia, there is a lack of studies on flood damages estimation. In addition, the needed data for the assessment of flood damages is scarce. This review identified the approaches and problems in flood damage assessment. For Malaysia, the combination of four elements namely; flood characteristics (flood depth and flood duration), characteristic of exposed elements, value of exposed element and flood damage function curve are recommended. The scarcity of data for developing flood damage curve could partly be overcome by applying synthetic method to generate additional data from the existing flood damage data

A combination of waste biomass activated carbon and nylon nanofiber for removal of triclosan from aqueous solutions

Triclosan (TCS) is one of the biocide used as antibacterial and antifungal agent to kill and hinder the growth of bacteria and also it is used in many personal care and health care products. However, TCS can cause health and environmental problems such as environmental pollutions, acute toxicity, etc. The aim of this study is to investigate the removal of TCS from aqueous solution by combining the coconut pulp waste (Cocos nuciefera) activated carbon (AC) with nylon 6,6 membrane. To this end, first, the effects of physico-chemical characteristics of the membrane were studied. The nylon 6,6 membrane (14 wt.%] was prepared using electrospinning machine with injection rate at 0.4 mL/h, tip-to-collector distance at 15 cm, rotation speed at 1000 rpm, and applied voltage at 26 kV. The parameters studied for the membrane during the adsorption test were contact time, adsorbent dosage, agitation speed, initial TCS concentration, pH, and temperature of the TCS solution. The filtration test was done using flat sheet membrane test machine at pressure 1.0 bar. The characteristics of the membrane were analysed using the FESEM and FTIR tests. Based on the obtained results, the nylon 6,6 membrane can remove 90.2% of TCS within 5 minutes; the removal rate increased to 100% in less than 5 minutes after the membrane was combined with AC. This study proved that the combination of AC and nylon 6,6 membrane is able to maximize the TCS removal from water

Alternative railway tools and sustainability in RAMS: A review

RAMS is a tool and methodology that combines reliability engineering, availability, maintainability, and safety in a way that is tailored to the system’s goals. A comprehensive view on RAMS’s components and theory behind the underlying mathematical model is not to be found in journal publication. This paper would also discuss several benefits and sustainability of RAMS. Life Cycle Cost (LCC) would also being introduce as a complementary discipline in term of costing that normally regarded parallel to RAMS. There are a series of methods that being utilized at every discipline of the RAMS component such as Fault Tree Analysis (FTA), Failure Mode Effect Critical Analysis (FMECA), Reliability Block Diagram and many more. Some commonly used methods would be highlighted in this paper. RAMS application and implementation will aid asset owners, contractors, and operators in efficiently procuring, developing, and operating their assets. However, further research and analysis is needed in the railway industry to build a viable framework for project and operation implementation using both tools

The challenges of extract, transform and load (ETL) for data integration in near real-time environment

Organization with considerable investment into data warehousing, the influx of various data types and forms require certain ways of prepping data and staging platform that support fast, efficient and volatile data to reach its targeted audiences or users of different business needs. Extract, Transform and Load (ETL) system proved to be a choice standard for managing and sustaining the movement and transactional process of the valued big data assets. However, traditional ETL system can no longer accommodate and effectively handle streaming or near real-time data and stimulating environment which demands high availability, low latency and horizontal scalability features for functionality. This paper identifies the challenges of implementing ETL system for streaming or near real-time data which needs to evolve and streamline itself with the different requirements. Current efforts and solution approaches to address the challenges are presented. The classification of ETL system challenges are prepared based on near real-time environment features and ETL stages to encourage different perspectives for future research