Open Access Original Research Article

Design and Construction of a Smart-home Automation System (SHAS) using Nodemcu and Google Assistant

G. I. Efenji, J. T. Zhimwang, M. M. Gwani, J. M. Uzer, S. A. Kazeem

Asian Journal of Research and Reviews in Physics, Page 1-10
DOI: 10.9734/ajr2p/2021/v5i430168

This paper presents the design and construction of a smart-home automation system using nodeMCU and Google assistant. The device consist of Enhanced Universal Synchronous Asynchronous Receiver Transmitter (EUSART) module that contains all clock generators, shift registers and data buffers necessary to perform an input or output serial data transfer independently of the device program execution. The NodeMCU (ESP8266) Wi-fi Shield connected the microcontroller to the provided Wi-fi network. The Arduino and MPLAB Programming Interface with the help of PICKit3 were used to run the code on PIC16F877A. Home appliances were controlled via a web page created using IFTTT for the voice command and the Blynk app for controlling hardware remotely and also display sensor data. IFTTT is a simple to use internet service that easily enables IoT devices to GET and POST data. The device was constructed based on low cost and reliable home controlled monitoring system for accessing and controlling electronics appliances remotely using any Smart phone with access to Google assistance or Computer web application. The device was test under different electronics appliances with different voltage capacities and was found efficient. Therefore, this device when used is capable of improving the living standard at home, reduces human effort, save energy and time thus make homes have sufficient automation.

Open Access Original Research Article

Important Atmospheric Parameters over a Indian Tropical Station Using Various Remote Sensing Instruments and a Model

S. Sreedevi, P. S. Brahmanandam, K. Tarakeswara Rao, V. Naveen Kumar, G. Anil Kumar, K. Samatha, M. P. Rao

Asian Journal of Research and Reviews in Physics, Page 11-20
DOI: 10.9734/ajr2p/2021/v5i430169

For the periods 01 July, 02 July, and 03 July 2018, important atmospheric parameters such as temperature, relative humidity, pressure, wind direction, and wind speed have been calculated over a tropical Indian station Gadanki (13.5°N, 79.2°E). Atmospheric Boundary Layer height (ABLH) was estimated using various analytical methods such as, vertical gradient, double gradient, and logarithmic gradient, and the results are compared with the European Centre for Medium-Range Weather Forecasts (ECMWF) ABLH data. With the COSMIC Radio Occultation (RO) technique and a regular balloon-borne radiosonde, tropopause heights and their corresponding temperatures were determined using minimum temperature criteria. Gradient and double gradient methods were more successful at capturing ABLHs than the logarithmic gradient method.

Open Access Original Research Article

Statistical Analysis on the Impact of Tropospheric Temperature and Relative Humidity on Downlink Satellite Communication System over Warri, Delta State

Opara C. Ezekwesili, J. T. Zhimwang, E. P Ogherohwo, O. S. Shaka

Asian Journal of Research and Reviews in Physics, Page 21-31
DOI: 10.9734/ajr2p/2021/v5i430170

This study was aimed at analyzing the effect of temperature and relative humidity on downlink satellite communication systems over Warri, in Delta State, Nigeria. The data used in this study were temperature, relative humidity and radio signal strength (RSS) obtained from the Nigeria Meteorological Agency (NIMET) for the years 2018 and 2019 respectively, both from January to December. Davis Vantage Vue weather station was used to measure the temperature and relative humidity while Spectrum analyzer was used to measure RSS. Both instruments were set to function simultaneously. Results obtained for all the months shows that the level of radio signal strength under the influence of temperature is higher either RSS ≥ 65% compare to that of relative humidity either RSS ≤ 64% which also fluctuate the level of RSS on daily basis, throughout the years under review. It was realized that there is a variation in the refractive index of the medium through which the radiowaves are propagated, due to the variations in the temperature and relative humidity, these adversely affect the received signals strength over the downlink satellite communication systems. The results obtained from this study will serve as guide for link budget design for satellite communication operators within the study. Therefore, similar study of this kind is recommended in other locations experiencing severe weather conditions.

Open Access Original Research Article

Development of Comfortable Umbrella with Fan by Using Solar Energy

. Hakiki, Hakim Khaula Nurul, Nugroho Yuniarto Wimbo, Hao Liu

Asian Journal of Research and Reviews in Physics, Page 32-37
DOI: 10.9734/ajr2p/2021/v5i430171

Heat waves often occur during sunny days in tropical regions during summer season, with temperatures sometimes reaching over 42 degrees Celsius. Because overheat waves can cause heatstroke for human beings who work outside, umbrellas are usually used to cut off sunshine to protect them. In the paper, an umbrella prototype is designed, which can drive a fan to provide cooling effect for persons who work outside in tropical regions. The designed umbrella uses solar cell attached on the above surface of the umbrella to convert solar energy into electricity, which is used to drive a fan or charge a battery. Moreover, the battery can also drive the fan when sunshine intensity is weak, or provide a charging port with 5 voltages for portable devices, such as mobile phones. The key component to realize these functions is an electronic control module, which includes charging circuit and discharging circuit. The former increases output voltage from the solar cell to the desired voltage to charge the battery; the latter can control electricity from the battery to drive the DC motor fan, LED indicator, and charging port.

Open Access Original Research Article

Extragalactic Radio Quasars: Consequences of the Luminosity/ Redshift Relationship

Ezeugo Jeremiah Chukwuemerie

Asian Journal of Research and Reviews in Physics, Page 38-44
DOI: 10.9734/ajr2p/2021/v5i430172

We have used both analytical and statistical methods to show some plausible consequences of the luminosity/redshift relationships for compact steep spectrum (CSS) quasars and the more extended extragalactic radio (EGR) quasars. From the analytical methods (or theory), we find that luminosity shows an inverse dependence on the redshift; while from the statistical (empirical) the converse is the case for both CSS quasars and their extended counterparts. We know that luminosity selection effects may play some role in the empirical results. However, we find that the magnitudes of departure of the two empirical results from the theoretical result are staggering – the difference for the extended EGR quasars far outweighs that of the CSS quasars. We may state categorically that this discrepancy may simply be a sign of a factor in the intergalactic medium (IGM) that appears to cause the anomaly in the extended EGR quasars. This is because sources with similar powers are expected to produce similar luminosities; and besides, central engines of the more extended EGR quasars have roughly similar powers with the CSS central engines. However, our results show great difference between their radiated powers (luminosities). A likely explanation of this is that the irregularity may be a signature of dark/vacuum energy. It simply indicates that among other factors, dark energy may constitute a factor which influences luminosities of the more extended EGR quasars. The components (jets and lobes) of the more extended EGR quasars lie in the intergalactic medium (IGM). This medium is more of a vacuum than the interstellar medium (ISM) in which the components of the CSS sources are located. Therefore, dark energy is expected to show more effect in the IGM than in the ISM. Besides, we estimate percentage influence caused by luminosity selection effect and that caused by the presumed dark/vacuum energy. The estimates are respectively,  and . These results show that intrinsically, dark/vacuum energy influences extended EGR quasars’ luminosities by about  times more than the observational bias caused by luminosity selection effects.