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Applications of Drones and Image Analytics in Field Phenotyping: A Potential Breakthrough in Uganda’s Agricultural Research
(SSRN, 2022) Bongomin, Ocident; Lamo, Jimmy; Guina, Joshua Mugeziaubwa; Okello, Collins; Ocen, Gilbert Gilibrays; Obura, Morish; Alibu, Simon; Owino, Cynthia Awuor; Akwero, Agnes; Ojok, Samson
We are in the race against time to find new solutions amidst the threat of climate change, to increase food production by 70% to feed the ever-growing world population which is expected to double by 2050. Agricultural research plays astonishing roles in crop and livestock improvement through breeding programs and good agronomic practices to enable sustainable agriculture and food systems. The advanced molecular breeding or modern breeding technologies in genotyping have been well-embraced by most research institutions worldwide. However, phenotyping which plays great role in agricultural research and breeding programs has achieved little development or still a traditional method in most institutions across African countries. Noteworthy, the advancement of phenotyping has been gaining momentum and attracted a number of researchers in the recent past, this led to the coining of high-throughput phenotyping concept. Nevertheless, the comprehensive understanding of this concept remains limited in most research institutions in developing countries, especially Uganda. Therefore, the present review aimed to provide a summary of drone-based high throughput phenotyping used across different crops. The electronic literature search was conducted from non-academic and academic databases. The literature sources in the form of peer-reviewed journal articles, books, book sections, conference papers, thesis and dissertations, policy papers, organisation or company manuals, working papers, and reports were considered. In this review, the concepts of field phenotyping are discussed, drone classification and specifications are elaborated, the use cases of the drone-based high-throughput phenotyping are presented, drone imaging systems for phenotyping are discussed, and high-throughput image analytics method is explained. In this paper, it was found that cereals have been the most studied crop for drone based phenotyping application in academic literature. However, root crops were the list studied, hence, extensive research is needed for drone-based phenotyping adoption in root crops. Moreover, limited studies have been focused on the effect of drones’ operation parameters. Therefore, research focusing on the optimization of the drones’ performance is required.
Appraising Bioenergy Alternatives in Uganda Using Strengths, Weaknesses, Opportunities and Threats (SWOT)-Analytical Hierarchy Process (AHP) and a Desirability Functions Approach
(Energies, 2014-02-26) Okello, Collins; Pindozzi, Stefania; Faugno, Salvatore; Boccia, Lorenzo
Poor access to clean and reliable energy technologies is a major challenge to most developing countries. The decision to introduce new technologies is often faced by low adoption rates or even public opposition. In addition, the data required for effective decision making is often inadequate or even lacking, thus constraining the planning process. In this study, a methodology for participatory appraisal of technologies, integrating desirability functions to the strengths, weaknesses, opportunities and threats (SWOT)-analytical hierarchy process (AHP) methodology was developed. Application of the methodology was illustrated with an example for participatory appraisal of four bioenergy technologies in Uganda. Results showed that the methodology is effective in evaluating stakeholder preferences for bioenergy technologies. It showed a high potential to be used to identify and rate factors that stakeholders take into consideration when selecting bioenergy systems. The method could be used as a tool for technology screening, or reaching consensus in a participatory setup in a transparent manner.
Appraising Bioenergy Alternatives in Uganda Using Strengths, Weaknesses, Opportunities and Threats (SWOT)-Analytical Hierarchy Process (AHP) and a Desirability Functions Approach
(MDPI, 2014-02-26) Okello, Collins; Pindozzi, Stefania; Faugno, Salvatore; Boccia, Lorenzo
Poor access to clean and reliable energy technologies is a major challenge to most developing countries. The decision to introduce new technologies is often faced by low adoption rates or even public opposition. In addition, the data required for effective decision making is often inadequate or even lacking, thus constraining the planning process. In this study, a methodology for participatory appraisal of technologies, integrating desirability functions to the strengths, weaknesses, opportunities and threats (SWOT)-analytical hierarchy process (AHP) methodology was developed. Application of the methodology was illustrated with an example for participatory appraisal of four bioenergy technologies in Uganda. Results showed that the methodology is effective in evaluating stakeholder preferences for bioenergy technologies. It showed a high potential to be used to identify and rate factors that stakeholders take into consideration when selecting bioenergy systems. The method could be used as a tool for technology screening, or reaching consensus in a participatory setup in a transparent manner.
Assessment of nitrogen content in buffalo manure and land application costs
(Page Press, 2012-08-29) Faugno, Salvatore; Pindozzi, Stefania; Infascelli, Roberta; Okello, Collins; Ripa, Maria Nicolina; Boccia, Lorenzo
Buffalo (Bubalus bubalis) livestock for mozzarella cheese production plays a fundamental role in the economy of southern Italy. European and Italian regulations consider nitrogen content in buffalo manure to be the same as that of cattle manure. This study aimed to assess whether this assumption is true. The first aim of the study was to assess nitrogen con tent in buffalo manure. Samples were taken from 35 farms to analyse nitro gen and phosphorous concentration in the manure. Analysis confirmed a lower nitrogen concentration (2%) in buffalo manure. A secondary aim of the study was to evaluate whether manure application techniques that are apparently less suitable, e.g. splash plate spreader, could be feasible. The cost of different methods of land application of manure and their charac teristics were evaluated on the basis of one operational cycle. Considering losses for volatilisation, and taking into account cost assessment, the immediate incorporation of buffalo manure (nitrogen content 2%) is a suitable method of ammonia volatilisation. However, it is expensive and involves high fuel consumption in relation to the environmental benefit.
Banana plant wastes for biofuels: indicators from characterization for thermochemical conversion
(Taylor & Francis, 2026-03-19) Menya, Emmanuel; Wakatuntu, Joel; Turyasingura, Medard; Okot, Christopher; Storz, Henning; Kabenge, Isa; Kizito, Simon Savio; Komakech, Allan John; Olupot, Peter Wilberforce; Okello, Collins
The banana value chain in Uganda generates a wide range of waste biomass, yet its suitability for thermochemical conversion remains largely unstudied. This study aimed to characterise banana rhizome, pseudostem, peduncle and inflorescences from Mbwazirume and Mpologoma cultivars in Uganda for potential use in thermochemical conversion processes. These wastes were characterised for lignocellulosic, proximate, elemental, and mineral composition, and higher heating value (HHV). Moisture content ranged from 9 to 14wt%, volatile matter 74-82%db, fixed carbon 12–17%db, and ash content 3-13%db. Inflorescences exhibited the highest lignin content (15.23–17.23%daf) and HHV (14.55–15.85 MJkg−1) across cultivars, suggesting higher suitability for biochar production compared to its counterparts. However, inflorescencesexhibited the highest nitrogen content (2.47–2.56%daf), suggesting higher NOx emissions potential. Inflorescences, rhizomes and peduncle exhibited higher ash content (6–13%db) than pseudostem (3.35–3.85%db), suggesting increased risk of slagging and fouling of heat transfer surfaces. Predominant mineral elements were found to be K (15888–28363 ppm), Ca (2000–9000 ppm), Si (2000–9000 ppm), and Mg (1120–4928 ppm), which can have catalytic functions during thermal decomposition. The low fuel ratio (0.16–0.22) of the wastes suggested poor fuel properties. These properties could be enhanced through torrefaction, making the wastes more suitable as sustainable feedstocks for biofuel production.
Biogas as an alternative to fuelwood for a household in Uleppi sub-county in Uganda
(Agric Eng Int: CIGR Journal, 2013-01-24) Menya, E.; Alokore, Y.; Ebangu, B. O.
Over 93% of Uganda’s population relys on wood fuel in form of either charcoal or fuelwood for cooking. Uleppi sub-county in Arua district is a typical example of such areas in Uganda where households entirely use fuelwood to meet their energy demand for cooking. The use of fuelwood is however associated with the use of inefficient stoves that accelerate deforestation thus increasing carbon dioxide (CO2) emissions. The use of fuelwood is also associated with a smoky environment that has adverse health impacts on women and children who spend long hours in the kitchen. In addition, women and children spend long hours gathering fuelwood which significantly reduces farm productivity. This project was therefore aimed at design and construction of a biogas plant ideal for a household in Uleppi sub-county as an alternative to fuel wood. The research involved sizing of the floating drum biogas digester and gasholder, economic analysis as well as estimating CO2 emission reduction. For a household with an average of three heads of cattle managed in a free range system, the biogas digester and gasholder were sized as 1.4 m3 and 0.29 m3 respectively with 0.48 m3 of biogas produced per day. At this capacity, it was found that biogas utilization can reduce individual household consumption of wood fuel by 66.32% for a household size of five persons. The carbon emission reduction for all households was estimated at 432 tons of CO2 per year. The benefit-cost ratio was found to be 3.26, hence worthy to invest in the biogas technology. The capital recovery period for 459 USD of the biogas plant installation with an economic life of 15 years at 23 % interest rate was found to be two years.
Characterization and alkaline pretreatment of rice husk varieties in Uganda for potential utilization as precursors in the production of activated carbon and other value-added products
(Elsevier, 2018-10-06) Menya, E.; Olupot, P.W.; Storzc, H.; Lubwama, M.; Kirosd, Y.
In this study, 13 rice husk (RH) varieties from 4 agro-ecological zones in Uganda were characterized, NaOH-pretreated, and evaluated for their potential utilization as precursors for production of bio-oil, ash, char, and activated carbon for selected applications. RH varieties were characterized through particle size analysis, bulk density, proximate and ultimate analyses, specific surface area, pore volume, as well as lignocellulosic and inorganic compositions. Selected RH varieties were subsequently pretreated at NaOH concentrations of 1–4%w/v, using pretreatment ratios of 5 g RH: 40 mL NaOH. Properties varied among RH varieties, suiting them as feedstocks for different applications. Upland rice husk varieties are more suited precursors for production of bio-oil, and activated carbon due to their relatively lower ash content, higher specific surface area, as well as higher volatile matter and fixed carbon contents. Upland rice husks could as well be employed in the preparation of electrodes for electrochemical devices, due to their relatively higher specific surface area. A high ash content (21–32% dry basis) of lowland rice husks presents good prospects for their calcination, since larger amounts of rice husk ash could be obtained, and employed in different applications. Lowland rice husk varieties could also be more suited precursors for production of char for soil amendment, due to their relatively higher ash content, which subsequently increases their char yields. However, alkaline pretreatment of rice husks using 2–4%w/v NaOH can reduce the ash content by as much as 74–93%, depending on the rice husk variety, which paves way for utilizing rice husks with a high ash content in different applications. Aside from ash reduction, the enhanced specific surface area (1.2–1.7 m2 g−1), volatile matter (68–79%db) and fixed carbon (19–24%db) contents of NaOH-pretreated rice husks suggests they are more suited feedstocks than when employed in their raw form, for production of bio-oil, as well as activated carbon.
Comparative analysis of energy recovery and digestate quality from anaerobic co-digestion of fruit and vegetable wastes under ambient and mesophilic conditions
(Scientific reports, 2026-05-14) Kabenge, Isa; Komakech, Allan. J.; Rubagumya, Isaac; Kizito, Simon Savio; Ahmadisedigh, Hossein; Menya, Emmanuel; Lépine, Julien; Zziwa, Ahamada
Large quantities of fruits and vegetables are lost along the supply chain due to their perishable nature, with factors such as inadequate refrigerated transport, poor road conditions, and limited cold storage facilities contributing to this loss. Anaerobic digestion offers a promising solution for mitigating the negative impacts of fruits and vegetable wastes (FVW). This study investigated the anaerobic co-digestion of FVW under ambient and mesophilic conditions, focusing on biogas yield, digestate quality, and energy efficiency. A 50:50 mixture of FVW and cow dung at mesophilic temperatures resulted in the highest biogas yield of 1,328.4 mLg-1VS, with a specific methane yield of 258.4 mL CH4 g-1 VS. The digestate from this mixture contained 64.56, 15.34, and 20.32 gkg-1 of nitrogen (N), phosphorus (P), and potassium (K), respectively. The heavy metal concentrations of copper (Cu), zinc (Zn), lead (Pb), iron (Fe), and manganese (Mn) were 0.02, 0.51, non-detectable, 88.60, and 3.67 mgkg-1, respectively, all falling within the acceptable limits for digestate/compost quality according to national and international standards. However, additional regulated metals such as As, Cr, Hg, Se, and Cd were not analyzed in this study. Therefore, compliance with international biofertilizer standards should be limited to the analyzed heavy metals. Although the average H2S levels remained below 22 ppm, routine monitoring is advisable, as elevated levels can compromise biogas quality, necessitating additional costs for biogas purification. From an energy recovery perspective, integrating insulation and correctly sizing the tank was found to improve both energy yield and operational efficiency, thereby enhancing the overall sustainability of the anaerobic digestion system. Further research should focus on temperature adaptability experiments in different climate zones, co-digestion with other organic wastes, long-term operational stability testing at the pilot scale, heavy metals and microbial analysis of the solid digestate.
Development and appraisal of hand wash-wastewater treatment system for water recycling as a resilient response to COVID-19
(Elsevier, 2021-07-28) Olupot, Peter Wilberforce; Menya, Emmanuel; Jjagwe, Joseph; Wakatuntu, Joel; Kavuma, Tonny; Wabwire, Andrew; Kavuma, Steven; Okodi Mcmondo, Samuel; Nabuuma, Betty; Mpagi Kalibbala, Herbert
In this work, results from characterization of handwashing wastewater from selected stations in Kampala City, Uganda, revealed that handwashing wastewater did not meet permissible international standards for wastewater discharge to the environment. The ratio of BOD5 to COD of ˂ 0.5 implied that handwashing wastewater was not amenable to biological treatment processes. Turbidity of ˃ 50 NTU pointed to the need for a roughing filter prior to slow sand filtration. Subsequently, a handwashing wastewater treatment system consisting of selected particle sizes of silica sand, zeolite, and granular activated carbon as filtration and/or adsorption media was developed and assessed for performance towards amelioration of the physicochemical and biological parameters of the handwashing wastewater. Treated water from the developed wastewater treatment system exhibited turbidity of 5 NTU, true color of 10 Pt-Co, apparent color of 6 Pt-Co, and TSS of 9 mgL-1, translating to removal efficiencies of up to 98.5%, 98.1%, 99.7%, and 96.9%, respectively. The residual total coliforms and E. coli of 1395 and 1180 CFU(100 mL)-1 respectively, were totally eliminated upon disinfection with 0.5 mL NaOCl (3.5% wt/ vol) per liter of treated wastewater. The treated water was thus suitable for recycling for handwashing purposes as opposed to letting handwashing wastewater merely go down the drain. This approach provides a resilient response to COVID-19, where communities faced with water scarcity can treat and recycle handwashing wastewater at the point of washing. It thus enables more people to have the opportunity to practice handwashing, abating the high risks of infection, which could otherwise arise.
Effect of alkaline pretreatment on the thermal behavior and chemical properties of rice husk varieties in relation to activated carbon production
(Springer, 2019-07-19) . Menya, E; Olupot, P. W.; Storz, H.; Lubwama, M.; Kiros, Y.; John, M. J.
Thermal behavior and chemical properties of selected raw and NaOH-pretreated rice husk varieties were investigated. NaOH- pre treatment process involved soaking 5 g rice husk samples in 40 mL of 2%w/v NaOH, shaking (400 rpm) and heating (50 C) for 3 h. NaOH- pretreated samples were water-washed, oven-dried, and milled for use in the determination of their thermal behavior and surface functional groups. Alkaline wash water was also analyzed for sugar components. Thermal decomposition temperatures, degradation rates, and the subsequent mass losses varied from one rice husk variety to another. These thermal properties increased after NaOH pretreatment of the rice husk varieties, reducing their char yields (17.1–20.4% db). These changes mainly had to do with the lignin, hemicellulose, and ash removal from the rice husk varieties, as confirmed by their FTIR analysis, as well as by the sugar composition analysis of their alkaline wash-water. Consequently, the FTIR spectra differed between the raw and NaOH-pretreated rice husk varieties
Effects of Mulching on Soil Hydro-Physical Properties in Kibaale Sub-catchment, South Central Uganda
(Science and Education Publishing, 2015-10-11) Kakaire, Joel; Makokha, George L.; Mwanjalolo, Majaliwa; Mensah, Albert K; Menya, Emmanuel
Mulching is one of the major soil and water conservation measures applied for conserving soil moisture and modifying soil physical and chemical environment. The study aimed at assessing the effect of mulching on soil hydro-physical properties in Kibaale sub-catchment in South Central Uganda. Samples were obtained between 0-20 cm depths and under 0, 5, 10 and 15 cm mulch thickness levels. The experiment involved 3 farmers and 4 treatments of corn residue mulch thicknesses each replicated thrice on each of the farmer sites. The main parameters of study were; bulk density, saturated hydraulic conductivity (Ksat) and water retention. The parameters were determined using core method, constant head method and pressure plates’ method respectively. Laboratory data was statistically analyzed using Analysis of Variance (ANOVA) from Genstat software Edition 4 and the means differentiated using 5 % least significant difference (LSD). The application of mulch significantly improved all the soil hydro-physical properties that were studied (bulk density, Ksat, field capacity, wilting point, porosity, soil organic matter (SOM), mean weight diameter (MWD) after two seasons. The level of improvement was highest with 10 cm mulch thickness while Ksat, porosity and SOM varied significantly (P< 0.05) with mulch thickness. The study recommends the use of 10 cm mulch thickness. This study provides information to stakeholders such as agricultural experts, watershed managers, farmers and policy makers which will help in formulating guidelines on how to incorporate mulching as an effective method for soil and water conservation in the Sub-catchment
Effects of sawdust and adhesive type on the properties of rice husk particleboards
(Elsevier, 2022-11-17) Olupot, Peter Wilberforce; Menya, Emmanuel; Lubwama, Festo; Ssekaluvu, Lawrence; Nabuuma, Betty; Wakatuntu, Joel
This study set out to investigate the effects of adhesive type, rice husk and sawdust proportions on the properties of composite particleboards. Specimens of 200 × 200 × 24 mm were made by blending 500 g of rice husks with each adhesive type at a mass ratio of 1:1. The rest of the specimens of similar dimensions were prepared with addition of sawdust in the range of 10–40 wt%, while maintaining the ratio of biomass particles to adhesive at 1:1. Three commercial synthetic adhesives Fevicol (FV), Ponal (PA) and woodfix (WF) were used. The particle adhesive mixtures were molded into a mat which was subsequently cold pressed at 10 MPa and left to dry in air. Density, water absorption (WA), linear expansion (LE), thickness swelling (TS), modulus of elasticity (MOE), modulus of rupture (MOR) and screw holding capacity of the specimens were evaluated. Adhesives were found to have over 42% solid content, with similar liquid constituents but in varying proportions. FTIR library search for the spectra of FV, PA, and WF revealed correlations of 82.5%, 78.6%, and 50.2%, respectively with polyvinyl acetate. The developed boards had a density of 510–610 kg/m3, MOE 13–26 MPa, TS 9–31%, and LE 3–7%. These properties suit them for furniture boards and soundproofing. The properties improved with the increasing proportion of sawdust. FV and PA-bonded particleboards exhibited higher stability and strengths than WF-bonded particleboards due to higher concentrations of polyvinyl-acetate in the latter. Blending 40 wt% sawdust, 10 wt% rice husk with 50 wt% of either FV or PA showed better prospects.
Experimental evaluation of rice husk ash for applications in geopolymer mortars
(Keai publishing, 2021-02-26) Ogwanga, G.; Olupot, P.W.; Kasedde, H.; Menya, E.; Storz, H.; Kiros, Y.
Rice husks obtained from upland and lowland rice varieties were characterized by the composition and content of ash. Each of the rice husk varieties was fired at temperatures of 600, 800, and 900 °C for a soaking period of 3 h. The resultant rice husk ash was analyzed for oxide composition and crystallinity using X-ray fluorescence and diffraction techniques, respectively. The generated amorphous ash with the highest silica content, together with metakaolin, aggregate, water, and an alkaline activator was employed to formulate geo-polymer mortar prisms according to the standard EN 196–1. Results showed that the content of ash in the varieties ranged from 18.3% to 28.6% dry basis. Out of this, 89 wt%–96 wt% was silica, with amorphous and crystalline forms of silica obtained at 600 °C and 900 °C, respectively, regardless of the rice variety. However, at 800 °C, the silica in the generated ash exhibited both amorphous and crystalline forms. The amorphous ash generated at 600 °C was used in the formulation of geopolymer mortars. The compressive and flexural strength of the formulated mortar after 7 days of curing was 1.5 and 1.3 MPa, respectively. These results reveal the firing protocol to form pozzolanic ash, with potential applications in mortar production.
Experimental tests on a new harvesting system for Burley tobacco
(Page Press, 2013-09-12) Faugno, Salvatore; Okello, Collins; Infascelli, Roberta; Audino, Francesca; Ardito, Luca; Pindozzi, Stefania
The globalization of the tobacco production has led to a drop in com petitiveness of the Italian tobacco on the world market. Burley is the main variety of tobacco cropped in Campania region of Southern Italy. Its leaves have to be sewn, in the curing phase. Aim of this work is to show the results of the implementation of a new harvest machine pro totype. Basically, the machine used for Bright tobacco, totally mechan ical harvested, which doesn’t need to be sewn because it requires an indirect-fire treatment into the curing furnaces. The machine was modified in order to mechanize harvesting of Burley tobacco, and test ed on four cultivars of Burley tobacco under three different planting layouts. The Burley tobacco leaves can be harvested mechanically by pulling individual leaves off the stalk; leaves are then sorted and tied in bundles prior to sewing. A mechanical burley tobacco harvesting system was evaluated. This machine consists in realizing a leaves ori entation system based on the different weight between the leaf blade and the stalk enhanced by an air flow. The measurements taken were harvest timing, work capacity, and quality standards of the work car ried out. The results, in terms of user time, range from 6.67 h/ha to 7.80 h/ha while in terms of operational efficiency are between 88% and 89%. The average user capacity recorded for the four cultivars is equal to 0.14 ha/h, a value far from the one recorded for the same harvesting machine used for Bright tobacco (0.25 ha/h). The harvest timing capacity, range from 0.51 t/h to 0.99 t/h. The work productivity goes from 0.17 t to 0.33 t per hour of human unit respectively. The average number of detached leaves, depending on the cultivar, has been between 523 and 744. Concerning the leaf orientation, a general per centage of 73% was achieved.
Factors affecting adoption of mulching in Kibaale sub-catchment, South Central Uganda
(International Journal of Sustainable Agricultural Management and Informatics, 2016) Kakaire, Joel; Mensah, Albert Kobinah; Menya, Emmanuel
Mulching is one of the major soil and water conservation measures applied for conserving soil moisture and modifying soil's physical environment. The study aimed at determining the factors which influence the adoption of mulching in the Kibaale sub-catchment, Uganda. 100 structured questionnaires; key informant interviews and observation were used to obtain the socio-economic and institutional data. To determine the factors affecting the adoption of mulching, descriptive statistics, and factor analysis were used. Chi-square (P ≤ 05) was used to establish the relationship between the identified factors and adoption. Using the chi-square test, the study also identified the Education level of household head, household size, accessibility to farmland, and marital status as the major factors that significantly affected adoption of mulching. The community leaders should ensure that the members attain some level of education and ensure that the land owned by individuals is within their periphery of management and control.
Fast-growing exotic tree species as fuelwood alternative for refugees and host communities in Northern Uganda
(Research Square, 2022-06-15) Anywar, Decimon; Shaban, Kato Stonewall; Labeja, Richard Louis; Loki, Robert Okongo; Okello, Collins
The high demand for firewood and charcoal has exerted high pressure on the indigenous trees in Uganda. 10 Communities believe that the indigenous trees are better fuel sources despite limited evidence to support this claim. 11 This study was carried out in 2021 to evaluate the fuelwood properties of selected indigenous tree species in 12 comparison to three exotic tree species that have been promoted for use by refugees and host communities in 13 Lamwo District of Northern Uganda. Wood samples were collected from three different locations from the study 14 area in Lamwo District and transported to Gulu University for laboratory analysis of their physical and chemical 15 properties. Data were analysed using one way analysis of variance (ANOVA) at 5% level of confidence and the 16 means were separated using Tukey HSD test. Results showed that moisture content, fixed carbon, volatile matter, 17 and Fuel Value Index (FVI) did not significantly vary among the indigenous and exotic tree species. Fuel value 18 index was observed to be negatively correlated with moisture content of the wood, implying both species’ categories 19 retard in fuel quality when their moisture contents increases. Overall, the results show that there were no significant 20 differences in the FVI of all the indegeneous and exotic tree species investigated in this study. It is recommended 21 that fast-growing exotic species such as Eucalyptus grandis, Caliandra calothyrsus, and Senna siamea that are 22 grown in the region be promoted to ensure regeneration and reduction of pressure on the use of natural forest.
Indirect field technology for detecting areas object of illegal spills harmful to human health: application of drones, photogrammetry and hydrological models
(PAGEPress Publications, 2014) Capolupo, Alessandra; Pindozzi, Stefania; Okello, Collins; Boccia, Lorenzo
The accumulation of heavy metals in agricultural soils is a serious environmental problem. The Campania region in southern Italy has higher levels of cancer risk, presumably due to the accumulation of geogenic and anthropogenic soil pollutants, some of which have been incorporated into organic matter. The aim of this study was to introduce and test an innovative, field-applicable methodology to detect heavy metal accumulation using drone-based photogrammetry and micro rill network modelling, specifically to generate wetlands wetlands prediction indices normally applied at large catchment scales, such as a large geographic basin. The processing of aerial photos taken using a hexacopter equipped with fifth-gen eration software for photogrammetry allowed the generation of a digital elevation model (DEM) with a resolution as high as 30 mm. Not only this provided a high potential for the study of micro-rill processes, but it was also useful for testing and comparing the capability of the topographic index (TI) and the clima-topographic index (CTI) to predict heavy metal sedi mentation points at scales from 0.1 to 10 ha. Our results indicate that the TI and CTI indices can be used to predict points of heavy metal accumulation for small field catchments.
Investigating the effect of different loading densities on selected properties of dried coffee using a GHE dryer
(CIGR Journal, 2023-09) Menya, E.; Komakech, A. J.
Despite coffee being one of the leading cash crops in Uganda contributing 20%-30% of the total export earnings, it is mainly dried on bare earth surfaces hence its drastic decline in quality. A possible alternative solution is the utilization of the greenhouse effect (GHE) solar dryer. This research was aimed at investigating the effect of different loading densities on selected properties of dried coffee using a GHE dryer that was designed and constructed at Makerere University Agricultural Research Institute Kabanyolo (MUARIK). The research involved determining the drying time for the loading densities of 5, 10 and 20 kg m-2 as well as analyzing the coffee quality at the end of the drying period. Three experimental runs were set up in the months of June and July which experienced an average ambient temperature of 23.28 (±2.33)oC and an average dryer temperature of 35.68 (±13.85)oC. The average drying time for the freshly harvested Robusta coffee at 61.3 (±1.36)% wb was 10 days for 5 kg m-2, 11 days for 10 kg m-2 and 12 days for 20 kg m-2. The loading of 20 kg m-2 resulted in an even roast with fair+ for body and flavour, while 5 and 10 kg m-2 loadings resulted in a silver skin roast with fair body and flavour. For this particular research, the loading density of 20 kg m-2 yielded the best results from the coffee quality analysis. The loading densities of 5 kg m-2 and 10 kg m-2 could not yield the best results due to case hardening of the outer surfaces of the coffee beans which compromised the body and flavour of the coffee.
Optimization of pyrolysis conditions for char production from rice husks and its characterization as a precursor for production of activated carbon
(Springer, 2019-03-13) Menya, E.; Olupot, P. W.; Storz, H.; Lubwama, M.; Kiros, Y.; John, M. J.
Response surface methodology was employed to optimize pyrolysis conditions for production of char with maximum yield, fixed carbon content, and with minimum ash content from Uganda’s New Rice for Africa (NERICA) 1 rice husk variety. The aim was to obtain rice husk char with more suitable properties as an activated carbon precursor. Mathematical models were developed to explain the relationships between the experimental responses and the pyrolysis parameters of temperature (400–600 °C), heating rate (10–25 °C min−1), and heating period (60–120 min). The optimized rice husk char was further characterized for elemental and proximate compositions, thermal behavior, specific surface area, as well as surface functional groups. Results from the analysis of variance (ANOVA) revealed that the quadratic model best fits each of the responses. Pyrolysis temperature had the greatest influence on each of the responses, followed by heating period, and lastly heating rate. Optimum pyrolysis conditions were found to be temperature (406 °C), heating rate (10 °C min−1), and heating period (60 min), resulting in char yield, fixed carbon, and ash contents of 35.26, 55.39, and 35.01% dry basis, respectively. Compared to raw rice husk, the resulting rice husk char was found more suited as activated carbon precursor, due to its enriched carbon content (60.35%) and specific surface area (123.9 m2 g−1). Thermogravimetric analysis of the rice husk char revealed that thermal activation temperatures higher than 400 °C may be required to considerably devolatilize the char, forming a more porous activated carbon.
Optimization of pyrolysis conditions for char production from rice husks and its characterization as a precursor for production of activated carbon
(Springer, 2019-03-13) Menya, E.; Olupot, P. W.; Storz, H.; Lubwama, M.; Kiros, Y.; John, M. J.
Response surface methodology was employed to optimize pyrolysis conditions for the production of char with maximum yield, fixed carbon content, and minimum ash content from Uganda’s New Rice for Africa (NERICA) 1 rice husk variety. The aim was to obtain rice husk char with more suitable properties as an activated carbon precursor. Mathematical models were developed to explain the relationships between the experimental responses and the pyrolysis parameters of temperature (400–600 °C), heating rate (10–25 °C min−1), and heating period (60–120 min). The optimized rice husk char was further characterized for elemental and proximate compositions, thermal behaviour, specific surface area, as well as surface functional groups. Results from the analysis of variance (ANOVA) revealed that the quadratic model best fits each of the responses. Pyrolysis temperature had the greatest influence on each of the responses, followed by heating period, and lastly heating rate. Optimum pyrolysis conditions were found to be temperature (406 °C), heating rate (10 °C min−1), and heating period (60 min), resulting in char yield, fixed carbon, and ash contents of 35.26, 55.39, and 35.01% dry basis, respectively. Compared to raw rice husk, the resulting rice husk char was found more suited as activated carbon precursor, due to its enriched carbon content (60.35%) and specific surface area (123.9 m2g−1). Thermogravimetric analysis of the rice husk char revealed that thermal activation temperatures were higher than 400 °C may be required to considerably devolatilize the char, forming a more porous activated carbon.

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