v.6 n.5 July

Parana Journal of Science and Education. v.6, n.5, July (2020).


Summary

Articles

Stefan Bernhard Rüster.

Parana J. Sci. Educ., v.6, n.5, (1-8), July 8, 2020.

DOI: doi.org/10.6084/m9.figshare.12645395

Abstract

The author has a new interpretation for the cosmological constant. In this context, a fundamental conservation law is found, which also solves the problem of the missing energy-momentum density of the gravitational field in the theory of General Relativity. The cosmological constant is a conserved quantity, which is proportional to the total energy-momentum density in the metric under consideration. Consequently, dark energy is nothing else than the total energy-momentum density in the Friedmann-Lemâiıtre-Robertson-Walker (FLRW) metric, which is proportional to its cosmological constant, that drives the accelerated expansion of our universe. Dark matter arises from the total energy-momentum density in any other metric under consideration than the FLRW metric for our cosmos. Consequently, dark matter is related to the cosmological constant of the respective considered metrics. The rotation curves of spiral galaxies become flat for a cosmological constant of about approximately minus thousand times its universal value. They also increase at large distances from the galactic center, which is in agreement with observations. It is shown, that dark matter is not detected by gravitational lensing.



Ritvik Jain and Yash Dhadke.

Parana J. Sci. Educ., v.6, n.5, (9-14), July 8, 2020.

Abstract

The following paper discusses various factors that affected the Indian energy sector during the nationwide lockdown caused by the Covid-19 pandemic. An assessment has been made as to how the inclement circumstances caused massive disruptions in the electricity output on either side of the lockdown. An inquest has also been made in the decreased output of the coal powered plants throughout the country and the parallel rise of non-fossil fuel sources of energy. This paper also provides adequate data showing an uptick in the percentage of RES (Renewable Energy Sources) during the post lockdown period. The final part of the paper discusses the financial repercussions on the energy sector (production and distribution) faced by the central government and the state governments of India. The low energy demands put economical strain on the energy sector. While the cost of production remains the same, the low consumption of energy leads to low billing rates, in turn reducing the profit margin and forcing the energy sector to incur losses and carry out mass layoffs. The authors conclude the paper suggesting an urgent need to gradually move from fossil fuel powered energy production to RES energy production, which would help India to keep its international goals of achieving clean energy, secure its future energy demands and essentially make India an energy independent nation.



Mehedi Hassan Masum, Foysal Ahmed and Sujit Basak.

Parana J. Sci. Educ., v.6, n.5, (15-24), July 8, 2020.

Abstract

Understanding the correlation betweenclimatic parameters and COVID-19 pandemic is important to control the COVID-19transmission. In this study, correlation between climatic parameters andconfirmed COVID-19 positive cases was done in Dhaka during COVID-19 lockdownperiods. Rainfall (mm), Temperature (ºC), Relative humidity (%), Wind speed (km/h)have been considered as climatic parameters. Trend analysis of the climaticparameter and confirmed COVID-19 positive cases were done using Mann Kendall (M-K) analysis and magnitudeof changes were determined using Sen’s Slope method. Correlation coefficientswere determined using Spearman’s rank correlation coefficient method as normaldistribution was not found among the parameters. Four timeframes have beenconsidered namely on the day of tests, 3,7,14 days before the day of tests wereconsidered to represent the incubation periods. The results found that relativehumidity shows strong correlation (rs= 0.517, p < 0.01) with confirmedCOVID-19 positive cases. Rainfall also show strong correlation (rs= 0.344, p < 0.01) withconfirmed COVID-19 positive cases. Moreover, temperature and wind speed shownegative and positive correlation with confirmed COVID-19 positive casesalthough the correlations are not strong. The findings of the results willsurely help the concern authoritiesand decision-makers on taking specific measures to control the COVID-19transmission for the cities.



Victoria Alexandrovna Kuzmichova and Valery Borisovich Morozov

Parana J. Sci. Educ., v.6, n.5, (25-28), July 8, 2020.

Abstract

In Einstein equation, there is seen an absence of a gravity field as a source of another gravity field. That is why for the Einstein equation solutions, the local law of energy-momentum conservation is not true. Lass proposed a homogeneous metric. Based on this metric, we obtained the exact metric of a homogeneous gravitational field. This metric generates a plausible field energy density and regular vacuum tensions. The exact metric of homogeneous fields does not belong to Einstein equation solutions. That is why, the problem arouses of constructing of a gravity field equation based on new principles.



Alireza Heidari.

Parana J. Sci. Educ., v.6, n.5, (29-60), July 8, 2020.

Abstract

Lopinavir is an antiretroviral of the protease inhibitor class. It is used against HIV infections as a fixed–dose combination with another protease inhibitor, ritonavir (lopinavir/ritonavir). In the current research, the stimulated ATR–FTIR biospectroscopy of liquid sample of Lopinavir was investigated. The stimulated ATR–FTIR diffractions emitted through focusing the second harmonic laser beam Nd:YAG into the sample were recorded by Echelle spectrometer and ICCD detector. Increasing the energy of laser beam from 2.6 (mJ) to 16 (mJ) was led to increase in stimulated ATR–FTIR signal but after breakdown threshold of liquid sample, more increasing of energy was led to decrease in stimulate ATR–FTIR signals and for energies higher than 20 (mJ), they were disappeared.



Mehedi Hassan Masum, Sayed Mohammad Rahat Rahman and Sudip Kumar Pal.

Parana J. Sci. Educ., v.6, n.5, (61-67), July 8, 2020.

Abstract

Air quality management (AQM) isbecoming a major concern in Bangladesh due to rapid changes associated with itsdevelopment activities that is taking place at a rapid stride. The unplanneddevelopment along with urban population growth results in augmented demands fortransportation, energy and other infrastructures that further causing highemission footprint on environment. Air quality data was collected from an airquality monitoring system operated by the Department of Environment (DoE) from2014 to 2019 for Dhaka, Gazipur, Narayanganj, Chittagong, Sylhet, Khulna,Rajshahi and Barisal. The airpollutant CO, NOx, SO2, O3 ,, . and were taken into account forassessing the ambient air quality in major cities of Bangladesh. The trendanalysis was carried out to address the changes in ambient air quality. Theoutcomes of the present study found that the ambient air environment is mostlyunhealthy on the basis of the air quality index (AQI). The threatening AQI ismostly biased by the contribution with the particulate matter (PM) among otherpollutants in air especially during winter period in Bangladesh with little orno rain. Among the cities studied, Dhaka, Chittagong and Rajshahi exhibitsubstantially increasing AQI trend that demand immediate attention towardsimproved air environment. The findings of this study may assist localpolicymakers to adopt best management practices in air quality management inBangladesh.



Vasily Konstantinovich Novikov, Victoria Alexandrovna Kuzmichova and Sergey Vasilyevich Novikov.

Parana J. Sci. Educ., v.6, n.5, (68-74), July 8, 2020.

Abstract

The problem acuity wasnoted of the air pollution by the exhaust gases (EG) of automotive and tractormachinery (A&T machinery) used at ports for transshipment operations. It isshown that for implementation of ports’ practical activities of cargosloading/unloading, various A&T machinery types are used: portal cranes,gantry and bridge cranes, crawling, pneumatic and automotive cranes, floatingcranes, crane-reloaders, forklifts, loaders with drives, wheeled tractors withbuckets and drop-ramps, crawler-tractors, lifting and transportation machines,special machines, pneumatic transport. As each of the used A&T machinerytypes runs on the traditional fuel, they pollute the atmosphere by EG to acertain extent. Notably, the main atmospheric pollutants in the EG content areas follows: carbon monoxide, hydrocarbon compounds, nitrogen oxides, sulfur dioxide,lead compounds, soot and other solid emissions. Due to their properties, all ofthem are quite toxic and dangerous to both the environment and the humans. Themain methods and ways are described that can be used for reduction of theamount of EG generated due to the operation of A&T machinery or theirtoxicity reduction. In particular, the following methods are specified: theimprovement of engine designs and quality on the stage of their manufacturing;the EG neutralization in the vehicle exhaust systems; the use of new fuels; theuse of various additives to fuel; etc.




Parana J Sci Educ. ISSN: 2447-6153