Faculty of Science & Technology (FST)

Developing A Satellite Based Automatic System For Crop Monitoring: Kenya's Great Rift Valley A Case Study

2019-10-07T08:50:19Z

Developing A Satellite Based Automatic System For Crop Monitoring: Kenya's Great Rift Valley A Case Study Luciani, Roberto; Giovanni, Laneve; Munzer, Jahjah; Collins, Mito The crop growth stage represents essential information for agricultural areas management. In this study we investigate the feasibility of a tool based on remotely sensed satellite (Landsat 8) imagery, capable of automatically classify crop fields and how much resolution enhancement based on pan-sharpening techniques and phenological information extraction, useful to create decision rules that allow to identify semantic class to assign to an object, can effectively support the classification process. Moreover we investigate the opportunity to extract vegetation health status information from remotely sensed assessment of the equivalent water thickness (EWT). Our case study LVWKH.HQ\D¶V*UHDW5LIWYDOOH\ in this area a ground truth campaign was conducted during August 2015 in order to collect crop fields GPS measurements, leaf area index (LAI) and chlorophyll samples.

Doctoral Training in Inorganic Chemistry for Technological Innovations and Socio-Economic Development

2018-06-13T06:42:56Z

Doctoral Training in Inorganic Chemistry for Technological Innovations and Socio-Economic Development Kariuki, David K. In the current knowledge based world, doctoral training needs to be responsive to not only the advancement of knowledge through original research, but also meeting societal needs that are wider than academia. The knowledge society requires a creativity and flexibility of the researchers’ mindset for a number of different functions and careers that go beyond those directly related to research. Doctoral studying is at the epitome of academic practices and has increasingly achieved recognition as a key part of this process worldwide. There are select few doctorate holders and even fewer doctorate scientists leave alone inorganic chemistry doctorates holders. Previous studies, on the doctoral studying experience in Europe suggest that students face a variety of difficulties during their studies. Attrition rates among doctoral candidates have been reported to range from 30% to 50%, depending on the discipline and country. In Africa the statistics are more depressed as they are coupled with very low enrolment, lack of funding and very high average age of candidates. In addition, there is a high migration rate out of mother country. Doctoral training in inorganic chemistry across the globe is relatively low while its knowledge and skill is in high demand for cutting edge innovations and technologies. Inorganic chemists address issues in medicine and biology, energy storage and consumption, synthesis of materials, photo- and electrochemical homogeneous and heterogeneous catalysis, transition metal and main group organometallic chemistry, solid state and surface chemistry.

Characterization of Experimental Dental Cements Derived from Locally Available Aluminosilicate Materials in Kenya

2018-06-13T05:59:26Z

Characterization of Experimental Dental Cements Derived from Locally Available Aluminosilicate Materials in Kenya Osiro, Olivia; Kariuki, David; Gathece, Loice An evaluation of locally available alkali-activated aluminosilicates (geopolymers) and clinker was carried out for the purpose of establishing a substitute material for development of atraumatic restorative treatment (ART) cements. Materials were obtained from local Portland cement manufacturers. Compositional analysis was carried out by Graphite Furnace Atomic Absorption Spectroscopy (GFAAS), X-ray Fluorescence (XRF), X-ray diffraction (XRD) and Fluoride Selective Electrode meter while Laser diffraction was used for particle size analysis (LDPSA) after sieving through a 53µm sieve. Geopolymers and clinker (0.5-1g) were mixed with freeze-dried poly(acrylic-acid) (0.1-0.2g) and aqueous tartaric acid (0.15-0.25mL) to produce cements whose setting time and compressive strength in 100% humidity was assessed after 1, 3 and 7d. Mineral trioxide aggregate (MTA) and glass ionomer cements (GIC) were used as controls. Geopolymers, clinker and MTA were found to contain varying ratios of SiO2 (18-74wt%), CaO (1-65wt%), Al2O3 (2-27wt%) and similar diffraction peaks of CaCO3, 2CaO.SiO2 and 3CaO.SiO2. MTA was found to contain Bi2O3 (16-33wt%) and Pb (1-2wt%), while geopolymers and clinker contained <0.001wt% Pb. Two geopolymers contained F- (5.99- 43.33µg/g). LDPSA reported an average particle size of 45 µm or less. The average mixing time was 1min while setting time ranged from 1.5-8min. All cements except those based on kaolin softened in distilled water at earlier time points but seemed to harden again after 28d. However, the kaolin cements exhibited the lowest CS (<5MPa) while one of the clinkers had CS of 14MPa after 28d.

Nontargeted nuclear magnetic resonance (NMR) analysis to detect hazardous substances including methanol in unrecorded alcohol from Novosibirsk, Russia

2019-07-21T11:34:47Z

Nontargeted nuclear magnetic resonance (NMR) analysis to detect hazardous substances including methanol in unrecorded alcohol from Novosibirsk, Russia Hausler, Thomas; Okaru, Alex O.; Neufeld, Maria; Rehmd, Jürgen; Kuballa, Thomas; Luy, Burkhard; Lachenmeier, Dirk W. Nuclear magnetic resonance (NMR) spectroscopy was applied to the analysis of alcoholic products in the context of health and safety control. A total of 86 samples of unrecorded alcohol were collected in Novosibirsk and nearby cities in Russia. Sampling was based on interviews with alcohol dependent patients, and unrecorded alcohol thus deﬁned included illegally or informally produced alcoholic products (e.g., counterfeit or home-made alcoholic beverages) or surrogate alcohol in the form of cosmetic or medicinal products and industrial non-beverage alcohol such as antifreeze (antifreeze windshield washer ﬂuid). For sample preparation, addition of buffer and of a water/ethanol mixture was required as single step. To detect potentially harmful samples, a nontargeted approach based on principal component analysis (PCA) was applied. The PCA scores plot shows six conspicuous samples with highly divergent scores from the rest. These samples are antifreeze windshield washer ﬂuids containing high amounts of methanol, with concentrations in a range between 7% and 48% vol. The antifreeze products were bought in regular retail sale and were claimed as “not containing methanol” on ﬁve out of six labels. Additionally, formic acid (1.1%) was observed in four of the alcohol-containing medicinal products. The major advantage of NMR over conventional methods is the fact that it not only provides the same quantitative data for speciﬁc compounds, but also allows rapid nontargeted screening for unknown contaminants.