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The particulate matter (PM) directly endangers the human health. Remotely sensed tiny atmospheric particles, aerosols, are presented in this research as atmospheric air pollutants. Globally overviewed for the first instances, and then a focus put on Africa and Asia, the selected aerosols are fine particulates (PM2.5), black carbon (BC), and Sulfate (SO4). According to the existing literature, the motivation to research on air pollutants came from the fact that the polluted air globally kills many people, by attacking cardiovascular system. The online accessible remote sensing’s data has been mostly collected from the second version of modern era retrospective analysis for research and applications (MERRA-2), a model selected for its update as well as the fact that its data are directly assimilated from the most renown remote sensors: Moderate resolution Imaging Spectroradiometer (MODIS) and the advanced very high-resolution radiometer (AVHRR). MERRA-2 also compiles data from different aerosol robotic networks (AERONETs). With a vast region of interest, and considering the big temporal resolution, reduced spatio-temporal resolutions facilitated the focused research. Goddard interactive online visualization and analysis infrastructure (GIOVANNI) bridged our research objectives with the data; Geographical Information Systems (Arc GIS) is a main software tool. Map-based as well as time series results for PM2.5 and other atmospheric air pollutants are presented; health dangers associated with the dust from erstwhile research highlighted. Finding that the annually-averaged mass concentration of the dust’s PM2.5 is significantly greater than the mean recommended concentration, 25 μg/m3, in all the seasons of the center of the research region of interest (Africa), this research recommends further research on dust aerosols mitigation strategies, during the seasons of heaviest air pollutants in particular.

Dust is associated with numerous hazards to the ecosystem; the dust aerosol affects the community health by polluting the breathable air and its effects on the balance of radiant energy are quite important for scientific research. Aerosols scatter and absorb solar radiation: some aerosols contribute to the heating of the earth and others to the cooling. With those problems, this research presents the behavior of three selected aerosols: dust, black carbon (BC) and sulfate (SO 4 ). The aerosol optical thickness (AOT) extinction behaviors were analyzed in comparison with the cloud amount and the surface skin temperature. In addition, we have quantitatively analyzed the dust’s particulate matter (PM 2.5 ), in the chosen region of interest (RoI). In all cases of this research, in the nearly recent 28 years (from Jan. 1991 to Jul. 2019), the aerosols data source is the second version of the modern-era retrospective analysis for research and applications (MERRA-2). A selection of the focal study region in south-west Asia was due to its location in the world’s dust-belt. Goddard interactive online visualization and analysis infrastructure, GIOVANNI, bridged our research objectives to the data; the Geographical Information System (GIS ArcMap) is one of the software tools that has been utilized to treat the map-based results. In results, among the three selected aerosols, the increase of the dust aerosol always associates with the decrease of the cloud amount in all the seasons of the focal region of interest. Regarding the effects of aerosols on earth’s energy balance, the upwelling longwave flux at the top of atmosphere under clear sky and no aerosol conditions was analyzed with the same longwave flux under normal conditions. On side of health effects in the focal region of interest, all seasons suffer from the heaviest dust’s fine particulate matter (PM 2.5 ). Though there might exist some examples of afforested deserts in Asia, which can be accounted for a good solution to the desert’s dust aerosols, we would recommend further studies about strategies to mitigate the dust hazards on both health and energy budgets.

Both the antenna miniaturization and bandwidth account for recent trends in designing modern antennas. This research is about the design of an ultra-wideband (UWB) planar monopole antenna, examining the specific absorption rate (SAR) induced by that antenna on a simplified human head model. The motives of the research are to miniaturize the antenna, targeting the UWB performance with minimized electromagnetic interference with the human brain fluid. An UWB small monopole antenna was designed, manufactured and tested (as a prototype); both the SAR and the electric field were simulated on a basic human head model. During the design process, as the antenna is grounded on one side, the performance is enhanced through impedance matching with the feed; electromagnetic (EM) far-field is strengthened too. Results from the grounded and ungrounded models at 3 GHz helped on the final prototype selection. A grounded monopole was selected, manufactured and the measured results proved the correctness of simulation results. The existing works in this area showed that computer simulation is a reliable method in studying electromagnetic radiation effects: sizing parameters and design properties are flexibly changed in simulation software. For main results, apart from the manufactured and tested prototype, the nearly zero SAR was achieved by simulation using the highfrequency structure simulator (HFSS) as a software tool; the brain fluid was directly placed in the main radiation near field beam of the antenna. The EM interference was studied on the modeled head and brain, in this research work; however, the same interference seriously affects the body’s organs which contain a big quantity of fluid, such as the heart, the cheeks, etc. Therefore, both the users and manufacturers of EM energy radiating devices are recommended to refer to their SAR design specifications before utilization, especially when those devices are intended to be used in closeness with the human body.

Attenuation due to rain is an important limitation in the designing of the microwave communication links operating at frequencies above 10 GHz. Video conferencing performs over high-speed link via high-speed satellite (WINDS satellite) transmission in the Ka-band which is vulnerable to attenuation due to rain. Using the ITU-R proposed models for the prediction of rain attenuation gives a good estimation for the microwave propagation loss caused by rain for the temperate regions, but it underestimates the rain attenuation prediction for the monthly variation of rain rate by averaging annual rain rate for particular region. This study was carried out at the University of Rwanda/Huye Campus. The rain rates were predicted for 0.01 percentage of time from rainfall data measured during two months of July and August using the RD-80 Joss and Waldvogel Disdrometer. From the data collected and analyzed, compared with ITU-R model, we can see that where Rwanda region is situated in region K, what is different from the obtained results because the data are collected during months that coincide with a dry season.

The dust has direct effects on people's health and climate change; so, this research studied the remotely sensed dust deposition in Africa from 1980 to 2018, and the dust's particulate matter of 2.5 μm size (or PM2.5), in particular, which pollutes the breathable air. PM2.5 is studied in comparison with multispectral carbon monoxide (CO), an abundant atmospheric air pollutant in central Africa. CO is an atmospheric gaseous pollutant for which the smoke, a gaseous aerosol from incomplete combustion processes, is the biggest source. The literature clarifies that both the particulate matter and the CO endanger human health while breathed in. The dust from the desert of Sahara is windblown all over the world. CO, in Africa, is from the anthropogenic fire and volcanic eruptions' smoke; these are two good reasons to have focused on Africa. Due to the big size of Africa, five sub-regions are set; these are the western, central, northern, eastern and southern sub-regions. The Goddard interactive online visualization and analysis infrastructure (GIOVANNI) has been a bridge to the collected remote sensing data, in this research. The data was collected online, from the measurement of pollution in the troposphere (MOPITT) as well as a second version of the modern era retrospective analysis for research and applications (MERRA-2); the analysis was done by a joint of the software tools, worth noting is the Arc GIS. As the amount of African dust dramatically increased by 2000; the heaviest in 2004, results are based on the selected dust deposition over 2000–2018: time-averaged maps, correlations, and quantitative estimations are reported in this research. The heaviest annual dust deposition reached 25.3 t/km2 over the year 2004, in Liberia, a focal point of study for the western sub-region. An important finding: the dust's PM2.5 positively correlated with multispectral CO from November to May; the positively high correlation coefficient was 0.86 in April 2018. The negative correlation between the two measurements started from June to October; the negatively high correlation was −0.68 in October 2015; this research discussed the possible reasons. This research recommends some onsite studies about the real figures and facts about the dust's effects on health, in all the seasons; thus, an alert to policymakers who would set some strategies to mitigate the dust hazards on the health of African inhabitants, neighbors, and visitors.

Recent research has been focused on development of models to enhance the resources allocated to Device to Device Communication (D2D) within LTE-A cellular network, which is considered as promising technology for improving network throughput, spectrum efficiency and transmission delay. The availability of huge number of smart phone at affordable price has increase cellular data traffic, generated by data sharing applications. Therefore, it is of critical importance to achieve efficient throughput in LTE-A networks. In this paper, we propose the possible solution to improve this throughput by analyzing and simulating a model to enable multiple concurrent D2D pairs in evolution NBs. We first evaluate mathematic model to enhance the resource allocated to D2D users. Second, we simulate D2D communication scenario in LTE-Advanced network using network simulator version 3 (NS-3) under Ubuntu environment. Throughput was measured by taking into consideration control overhead. We also investigate the throughput at high layer the Packet Data Convergence Protocol (PDCP), which is above the Radio Link Control (RLC) layer. The results show that there are benefit in channel capacity when LTE-A users are used together with multiple D2D pairs.

It is very useful to know the soil capabilities on different external impacts acting on it, especially for electromagnetic waves from Ground Penetrating Radar. In the underground detection domain actually, dealing with soil permittivity is one of the challenging research problems nowadays. In this paper, we study tropical soil constitution, taking in account the tropical climate region and we took Rwanda as a case study. Rwanda's elevation ranges from 1,000m (south and east) to 4,500m above sea level. The “thousand hills” terrain is dominated from north to south by a watershed (2.500m high) that separates the basin of the Congo River from that of the Nile and by the Ibirunga volcano chain. In spite of its proximity (2 degrees south) to the equator, the country enjoys a fine spring climate (due to its altitude), with two rainy seasons and two dry seasons. In fact, when considering the tropical climate region with his considerable rainfall period, it is better to collect information regarding the zone in consideration. Using Finite Difference Time Domain(FDTD) simulation with GPRMax simulator, and varying the permittivity, the aim of this paper is to have a benchmark of dry and rainfall season; this will help when doing measurements with the GPR instruments and others non destructive tools. In this paper, we analysed the clay soil (one of the component of Rwandan pedology) and from the variation of dry clay to wet clay associated with different fixed frequencies (300MHz, 600MHz, 900MHz, 1200MHz and 1500MHz). For each fixed frequency, we vary the clay permittivity from dry to wet clay and analysed data after simulation. From this benchmark, and in the near future work, we will use the GPR instrument and the Time Division Reflectometry(TDR) to verify the simulation results.

"Recently the road networks are more and more exposed to an increased landslide risk. It is generally caused by heavy weather conditions and a severe deficit of maintenance. Usually, it is easy to locate the damage as it becomes visible whereas it is difficult to identify the causes. In order to diagnose the damage before it becomes visible and severe, to identify the main cause and to implement the most effective rehabilitation measure, we propose the use of Ground Penetrating Radar for geotechnical inspection of pavement and sub-pavement layers. Different equipments were used and a survey protocol was tested in several situations characterized by landslide movements with different degrees of severity. For the inspection, 600, 1000 and 1600 MHz antennae were used. The 1 GHz horn antenna was used for a first survey at traffic speed in order to reduce traffic interference and to locate any possible anomaly. The other dipole antennae were used for more detailed investigations. GPR data were post-processed in the time and frequency domain, using the “Surface reflection method” and the Rayleigh scattering. This approach provides an innovative method that can be applied for accurate and non-invasive monitoring of alert conditions near to road pavements."