Hybrid Plasmonic Waveguide Fed Broadband Nano-antenna for Nanophotonic Applications

In this paper, we propose a novel hybrid plasmonic waveguide fed broadband optical patch nano-antenna for nanophotonic applications. Through full wave electromagnetic simulation, we demonstrated our proposed antenna to radiate and receive signal at all optical communication windows (e.g. $\lambda$ = 850nm, 1310nm & 1550nm) with around 86% bandwidth within the operational domain. Moreover numerical results demonstrate that the proposed nano-antenna has directional radiation pattern with satisfactory gain over all three communication bands. Additionally, we evaluated the antenna performances with two different array arrangements (e.g. one dimensional and square array). The proposed broadband antenna can be used for prominent nanophotonic applications such as optical wireless communication in inter and intra-chip devices, optical sensing and optical energy harvesting etc.Comment: 4 Page, 7 figure

Planar electromagnetic sensor based estimation of nitrate contamination in water sources using independent component analysis

The main advantages of electromagnetic sensors can be listed as low-cost, convenient, suitable for in-situ measurement system, rapid response, and high durability. In this paper, the output parameters of the planar electromagnetic sensor have been observed with different kind of water samples at different concentrations. The output parameters have been derived and tested to be incorporated with independent component analysis (ICA) and used as inputs for an analysis model. The analysis model targeted to estimate the amount of nitrate contamination in water samples with the assistance of ICA based on FastICA fixed point algorithm under the contrast functions of pow3, tanh, gauss, and skew. Nitrates sample in the form of ammonium nitrates (NH 4NO 3), each of different concentration between 5 mg and 20 mg dissolved in 1 litre of deionized water (Milli-Q) was used as one of the main references. The analysis model was tested with eight sets of mixed NH 4NO 3 and (NH 4) 2HPO 4 water samples. It is seen from the results that the model can acceptably detect the presence of nitrate added in Milli-Q water and capable of distinguishing the concentration level in the presence of other type of contamination. The system and approach presented in this paper has the potential to be used as a useful low-cost tool for water sources monitoring

Sea surface temperature retrieval using TRMM microwave imager satellite data in the South China Sea

The passive microwave TRMM Microwave Imager (TMI) sensor which is one of the payloads of the Tropical Rainfall Measurement Mission (TRMM) satellite was launched in 1997 by the National Aeronautics and Space Administration (NASA) and National Space Development Agency of Japan (NASDA). The TMI provides daily maps, 3 day average, weekly and monthly binary data via internet that can be used to retrieve geophysical parameters such as sea surface temperature (SST), 10 meter surface wind speed using 11 GHz channel, 10 meter surface wind speed using 37 GHz channel, atmospheric water vapour, liquid cloud water and precipitation rates. The SST study over the South China Sea was carried out using the 10.7 GHz channel of the TMI. The advantage of using this data is that the SST can be measured through clouds that are nearly transparent on this channel. This is a distinct advantage over the traditional infrared SST observations that require a cloud-free field of view. In this study, multitemporal TMI binary data were processed using FORTRAN Programming Language to evaluate the SST variations with time over the study area. The 3-day, weekly and monthly binary files are similar to the daily TMI binary files. All data consists of six maps with grid size of 0.25o by 0.25o and each file can be read as a 1440, 320, 6 array. For the data processing, the data values fall between 0 and 250 that need to be scaled to obtain meaningful geophysical data. The TMI scanning system causes striping that contains 0 or invalid data. In-situ temperature values were taken at locations where useful satellite data are available i.e. no striping. Regression analysis was carried out using the SST from TMI data and in-situ data obtained from the Meteorological Department of Malaysia. The two-dimensional scatter plot between TMI data and in-situ data gives a R2 value of 0.92 and RMSE of 0.3oC. The SST during the north east monsoon period was slightly lower than the SST during the south west monsoon. The study shows that TMI satellite data can be used to derive SST over large areas of the sea

Security comparison of ownCloud, Nextcloud, and Seafile in open source cloud storage solutions

Cloud storage has become one of the most efficient and economical ways to store data over the web. Although most organizations have adopted cloud storage, there are numerous privacy and security concerns about cloud storage and collaboration. Furthermore, adopting public cloud storage may be costly for many enterprises. An open-source cloud storage solution for cloud file sharing is a possible alternative in this instance. There is limited information on system architecture, security measures, and overall throughput consequences when selecting open-source cloud storage solutions despite widespread awareness. There are no comprehensive comparisons available to evaluate open-source cloud storage solutions (specifically owncloud, nextcloud, and seafile) and analyze the impact of platform selections. This thesis will present the concept of cloud storage, a comprehensive understanding of three popular open-source features, architecture, security features, vulnerabilities, and other angles in detail. The goal of the study is to conduct a comparison of these cloud solutions so that users may better understand the various open-source cloud storage solutions and make more knowledgeable selections. The author has focused on four attributes: features, architecture, security, and vulnerabilities of three cloud storage solutions ("ownCloud," "Nextcloud," and "Seafile") since most of the critical issues fall into one of these classifications. The findings show that, while the three services take slightly different approaches to confidentiality, integrity, and availability, they all achieve the same purpose. As a result of this research, the user will have a better understanding of the factors and will be able to make a more informed decision on cloud storage options