Simulation of the impact of people mobility, vaccination rate, and virus variants on the evolution of Covid-19 outbreak in Italy

We have further extended our compartmental model describing the spread of the infection in Italy. As in our previous work, the model assumes that the time evolution of the observable quantities (number of people still positive to the infection, hospitalized and fatalities cases, healed people, and total number of people that has contracted the infection) depends on average parameters, namely people diffusion coefficient, infection cross-section, and population density. The model provides information on the tight relationship between the variation of the reported infection cases and a well-defined observable physical quantity: the average number of people that lie within the daily displacement area of any single person. With respect to our previous paper, we have extended the analyses to several regions in Italy, characterized by different levels of restrictions and we have correlated them to the diffusion coefficient. Furthermore, the model now includes self-consistent evaluation of the reproduction index, effect of immunization due to vaccination, and potential impact of virus variants on the dynamical evolution of the outbreak. The model fits the epidemic data in Italy, and allows us to strictly relate the time evolution of the number of hospitalized cases and fatalities to the change of people mobility, vaccination rate, and appearance of an initial concentration of people positives for new variants of the virus.

Multifactorial Evaluation of Atenolol, Caffeine, Carbamazepine and Ibuprofen on Raphidocelis subcapitata and Chlorella vulgaris

Micropollutants in aquatic resources have raised global concerns regarding the conservation of ecosystems. Although they are usually found in the environment at trace concentrations to a maximum of several µg/L, it is still necessary to address the potential risks these pollutants may represent to organisms. A multifactor analysis was conducted using two algae as bioindicators. Four different pharmaceuticals were chosen based on their occurrence in domestic wastewaters and persistency after biological treatment processes ranging from 1/8th to four-fold representative environmental concentrations over 96 h exposure. The present multifactor analysis evaluated cell size, photosynthetic capacity and growth rate. These data were later combined into a simplified single entity: “the index effect”. The results obtained showed that, even at concentrations below the environmentally relevant concentrations (ERC), the pharmaceuticals’ residues (PRs), caused a cellular behavioural variation in both organisms. In addition, the algae cultures’ response to exposure to these stressors was generally dependent on the concentration over time. By examining four different PR over three different characteristics of two types of algal bioindicators, this work covers significant and specific responses on the algae exposure cycle. This is unique research since most studies do not consider multiple parameters in the assessment of the environment risk for bioindicators.

The Impact of Liquidity on Islamic Banks Profit: A Study on A Sample of Saudi Islamic Banks for the period 2013-2018: أثر السيولة في ربحية المصارف الإسلامية: دراسة عينة من المصارف الإسلامية السعودية للفترة الزمنية 2013-2018م

This research aimed to study the effect of Liquidity on Saudi Islamic banks profitability, to achieve the goals of the research, the researcher has determined a sample of Saudi Islamic banks, the sample included Al-Rajhi, Al-Inma and Al-Bilad, the research focuses on the time period 2013-2018. The research used a descriptive methodology for the theoretical part by gathering previous studies, studies and scientific journals, for the applied part, the research used an analytical methodology by collecting financial statements of the study sample to use these data for hypothesis tests using statistical analytical methods, the results show that there is a statistically index effect on the index level (0.05) of the Liquidity ratio on the return of assets index in Saudi banks, they also show that the liquidity is inversely proportional to the return. The research recommended that Islamic banks should expand their services and attract depositors to take advantage with them in investment operations, This will make positive effects on their profits, in addition to that, Islamic banks administrations have to evaluate Liquidity risks continuously to deal with surplus and deficit.

Modulation index effect on inverter based induction motor drive

Due to a substantial increase in the use of inverter for numerous electrical appliances starting from domestics to industrial drives, an inverter may be directly connected to the power grid system. The dependency on an inverter has been increased over the years. Hence, the proper and efficient design of the inverter will lead to higher efficiency. One of the major challenges is the generation of suitable gate pulses for power switching devices, which in turn depends on the modulation index. The selection of proper modulation index will help in the production of the rated voltage. If the modulation index is less, the duration of on-time pulses will be less and hence, the device's conduction time is also less, thereby the output voltage of the inverter is reduced. A reduced voltage, when applied to an induction motor will have lower speed and even its performance will be sluggish. The speed of the motor improves when it is operated in a closed-loop for the same modulation index. This research paper tries to bring out the effect of modulation index on speed control of an induction motor based on an inverter for both open as well as closed-loop operation. The simulated results indicate that the modulation index in the vicinity to unity will provide rated voltage for the smooth operation of the motor.

Multiwavelength Frequency Modulated CW Ladar: The Effect of Refractive Index

Frequency modulated continuous wave (FMCW) laser detection and ranging is a technique for absolute distance measurements with high performances in terms of resolution, non-ambiguity range, accuracy and fast detection. It is based on a simple experimental setup, thus resulting in cost restraint with potential wide spread, not only limited to research institutions. The technique has been widely studied and improved both in terms of experimental setup by absolute reference or active stabilization and in terms of data analysis. Very recently a multi-wavelength approach has been exploited, demonstrating high precision and non ambiguity range. The variability of refractive index along the path was not taken into account with consequent degradation of range accuracy. In this work we developed a simple model able to take into account refractive index effect in multi-wavelength FMCW measurement. We performed a numerical simulation in different atmospheric conditions of temperature, pressure, humidity and CO2 concentration showing a net improvement of range accuracy when refractive index modeling is used.