Advances in Nanomaterials Sciences and Nanotechnology for Sustainable Development: A Review

The fields of materials sciences have great opportunities to address the challenges of sustainable development of modern societies. The sub-disciplines of materials sciences of interest in this review are nanomaterials sciences and nanotechnology. Nanomaterials possess one external dimension measuring 1-100 nm. They have larger surface area for the same mass than their bulk materials. They are more reactive with effects on their electrical, optical and magnetic properties. Thus, nanomaterials are promising for sustainable development in the areas of energy, water, chemicals, electronics, medical and pharmaceutical industries, CO2 mitigation and agriculture. To this end, this review explores the advances in nanomaterials sciences, nanotechnology and the potential applications of nanomaterials for sustainable development. In this review, 73 peer reviewed articles and abstracts were retrieved. The review considered nanomaterials of carbon, inorganic materials, semiconductors, polymeric and lipid based materials. It has been found that nanomaterials sciences and nanotechnology is promising for potential applications in the areas of environmental remediation, energy, food, agriculture, industry, molecular biology, medicine and in pharmaceutical industries for sustainable development. Keywords: nanomaterials sciences, nanotechnology, sustainable development

Inversion free Iterative Method for Finding Symmetric Solution of the Nonlinear Matrix Equation 𝑿 − 𝑨∗𝑿𝒒𝑨 = 𝑰 (𝒒 ≥ 𝟐)

In this paper, we propose the inversion free iterative method to find symmetric solution of thenonlinear matrix equation 𝑿 − 𝑨∗𝑿𝒒𝑨 = 𝑰 (𝒒 ≥ 𝟐), where 𝑋 is an unknown symmetricsolution, 𝐴 is a given Hermitian matrix and 𝑞 is a positive integer. The convergence of theproposed method is derived. Numerical examples demonstrate that the proposed iterative methodis quite efficient and converges well when the initial guess is sufficiently close to the approximatesolution. Keywords: Symmetric solution, nonlinear matrix equation, inversion free, iterative method

A Mathematical Analysis of an In-vivo Ebola Virus Transmission Dynamics Model

Ebola virus (EBOV) infection is a hemorrhagic and hazardous disease, which is among the most shocking threats to human health causing a large number of deaths. Currently, there are no approved curative therapies for the disease. In this study, a mathematical model for in-vivo Ebola virus transmission dynamics was analyzed. The analysis of the model mainly focused on the sensitivity of basic reproductive number, pertaining to the model parameters. Particularly, the sensitivity indices of all parameters of were computed by using the forward normalized sensitivity index method. The results showed that a slight change in the infection rate immensely influences while the same change in the production rate of the virus has the least impact on . Thus, , being a determining factor of the disease progression, deliberate control measures targeting the infection rate, the most positively sensitive parameter, are required. This implies that reducing infection rate will redirect the disease to extinction. Keywords: Ebola virus infection, immune response, sensitivity index, mathematical model.

Impacts of Wood Fuel Uses on Forest Cover: The Case of Semiarid Areas in Northern Tanzania

Satellite images for the years 1987, 1997, 2002 and 2017, and questionnaire surveys were used to assess energy sources and demands as well as the impacts of wood fuel use to forest cover changes in Meru and Mwanga Districts. The major energy sources identified in the study areas include cow dung cake, firewood, charcoal, biogas, and liquefied petroleum gas. The total energy demands from these sources were 1400, 6289, 724 and 21 kg per day, respectively. Analysis from Landsat images showed variations in forest cover. The areas covered with forests in Meru District were found to be 1510, 1723, 1612 and 1327 ha for 1987, 1997, 2002 and 2017, respectively. The changes observed in Mwanga District were 31705, 31988, 17939 and 30960 ha for 1987, 1997, 2002 and 2017, respectively. From the findings it was observed that, the ongoing use of wood fuel in semi-arid areas of Meru and Mwanga Districts could deplete forests completely. The study concludes that charcoal and firewood consumptions are real threats to the long-term persistence of forests in Tanzania and proposes the use of renewable energy such as biogas for alleviating forest losses. Keywords: Biogas, energy sources, Satellite images

Automated Detection of Bilingual Obfuscated Abusive Words on Social Media Forums: A Case of Swahili and English Texts

The usage of social media has exponentially grown in recent years leaving the users with no limitations on misusing the platforms through abusive contents as deemed fit to them. This exacerbates abusive words exposure to innocent users, especially in social media forums, including children. In an attempt to alleviate the problem of abusive words proliferation on social media, researchers have proposed different methods to help deal with variants of the abusive words; however, obfuscated abusive words detection still poses challenges. A method that utilizes a combination of rule based approach and character percentage matching techniques is proposed to improve the detection rate for obfuscated abusive words. The evaluation results achieved F1 score percentage ratio of 0.97 and accuracy percentage ratio of 0.96 which were above the significance ratio of 0.5. Hence, the proposed approach is highly effective for obfuscated abusive words detection and prevention. Keywords: Rule based approach, Character percentage matching techniques, Obfuscated abuse, Abuse detection, Abusive words, Social media

Analysing Climate Change Mitigation Policy Options in the Renewable Energy Sub-Sector in Tanzania

Public policies influence reduction of greenhouse gas emissions. Also the extent to which policies are developed and implemented can influence the achievement of the national, regional and international climate change mitigation policy framework in the renewable energy sub-sector. This paper provides a critical overview of key policy options influencing the development of renewable energy sub-sector through climate change mitigation policy options in Tanzania. Questionnaire surveys were used to collect primary data from 100 relevant experts who represented 64 organizations in Tanzania. Secondary data were collected by literature review. The state of climate change mitigation policy options in the renewable energy sub-sector was assessed by using Statistical Product and Service Solutions (SPSS) version 26.0 and content analysis. The results showed Tanzania lacks adequate climate change mitigation policy and renewable energy policy frameworks. A specific national climate change policy and national renewable energy policy are needed to guide stakeholders to undertake climate change mitigation actions in the renewable energy sub-sector in Tanzania. Perceptions gained and recommendations made are essential for undertaking climate change mitigation actions in Tanzania, and can be relevant for other developing countries because of similar climate change mitigation contexts. Keywords: climate change, renewable energy, greenhouse gases, policies, Tanzania

Comparison of Nutritional and Anti-Nutritional Qualities of Grewia forbesii Hav. Ex Mast and Grewia bicolor Juss Fruits from Kitapilimwa Forest Reserve in Iringa District

The Grewia forbesii and Grewia bicolor fruits were collected from Kitapilimwa Forest Reserve and were analysed for proximate, nutrients and anti-nutrients compositions. Results showed low moisture contents in G. forbesii and G. bicolor amounting to 14.14 and 13.98 percent, respectively. Crude fibre percent was slightly higher in G. bicolor (33.15%) than G. forbesii (31.95%). Lipid content was slightly higher in G. bicolor (1.37%) compared to G. forbesii (1.28%). The crude protein content of G. forbesii (7.44%) was slightly higher than G. bicolor (7.00%). Total carbohydrate content of G. forbesii (68.9%) was higher than that of G. bicolor (70%). Mineral analysis indicated substantial amounts of potassium 898 mg/100 g in G. forbesii and 879 mg/100 g in G. bicolor. Calcium content was high in G. forbesii and G. bicolor amounting to 453 mg/100 g and 582 mg/100 g, respectively. Iron was high in both species (20.73–24.45 mg/100 g). Manganese, copper and zinc were substantially low. The results revealed low levels of tannin (< 1.7%) and phylates (< 0.3%). The presence of substantial amounts of nutrients and low anti-nutrients revealed that the studied species may be potential sources of nutritional food. Keywords: Proximate analysis, mineral nutrients, anti-nutritional qualities, Grewia species, Kitapilimwa Forest Reserve

Pair Distribution Function Analysis and Electrochemical Performance of Mesoporous Carbon Nanomaterials Synthesized Through KOH and ZnCl2 Activation

Mesoporous carbon has been synthesized by activating carbonized biogas slurry residues with ZnCl2 and KOH simultaneously. The carbon to activating agent mass ratios were kept at 1:4, while the ZnCl2 to KOH mass ratio varied from 4:0, 3:1, 2:2, 1:3, to 0:4. The highest BET specific surface area of 361 m2 g-1, micropore surface area of 231 m2 g‒1, mesopore surface area of 125 m2 g‒1, and total pore volume of 0.23 cm3 g‒1 which amounted to 78% mesopore content, were obtained for the sample with 3:1 ZnCl2 to KOH mass ratio. Scanning electron microscope (SEM) images were acquired to determine the surface morphology and energy dispersive X-ray (EDX) was used to determine surface composition of the samples. The short, medium, and long-range orders of the synthesized materials were studied using pair distribution function (PDF) analysis. PDF showed that in addition to the locally ordered carbon and silica phase components, samples activated using combined ZnCl2 and KOH also contained crystalline Zn2SiO4 phase with the willemite structure. Electrochemical studies in three-electrode cell system revealed maximum specific capacitance of 216 F g‒1 exhibited by sample with a ZnCl2: KOH mass ratio of 3:1 at a scan rate of 5 mV s‒1. Keywords: Mesoporous carbon; Pair distribution function, Specific capacitance, supercapacitor

Biological Characterization of Plasmodium falciparum Mitochondrial Heat Shock Protein PfHsp70-3: Possible Involvement in Malaria Pathogenesis

Malaria remains a global health burden accounting for many deaths and illnesses in sub-Saharan Africa notwithstanding many decades of research on the disease. P. falciparum, the causative agent of the most fatal form of malaria, expresses a repertoire of heat shock proteins (Hsp) that cushion the parasite against heat shocks as it shuttles between extreme temperatures in human and mosquito vector hosts. By so doing, such proteins promote parasite’s cytoprotection, survival and pathogenesis. Heat shock proteins are named according to their molecular weights and there are six P. falciparum Hsp70 (PfHsp70) found in various cell compartments with mitochondrial putative PfHsp70-3. Using indirect immunofluorescence, this study established mitochondrial localization of PfHsp70-3 though some more confirmatory studies would be needed in the future. PfHsp70-3 was found to be heat inducible and expressed during all stages of the intra-erythrocytic cycle of parasite development. This could be an indication of PfHsp70-3’s involvement in the infectivity process of P. falciparum by helping the parasite to resist heat shocks during malaria febrile episodes. Generally, the data obtained in this study will enhance the existing knowledge on the biology of P. falciparum mitochondrial heat shock protein functions and open possible avenues for targeting the specificity between PfHsp70-3 and its co-chaperones for drug development. Keywords: Malaria, P. falciparum, Heat shock proteins, PfHsp70-3, pathogenesis

Vulnerability and Responses of Smallholder Farmers to Climate Change Effects in Semiarid Areas of Bahi and Kongwa Districts, Tanzania

This study examined the vulnerability and responses of smallholder farmers to climate change effects in Semiarid Areas of Bahi and Kongwa Districts. A total of 366 household heads were involved in this study. The study employed questionnaire, interviews and documentary review as data collection techniques. Archival data for temperature, rainfall and crop yields were collected for trend analysis. Descriptive and inferential statistics were used to analyse quantitative data, content analysis was employed to analyse qualitative data. Simple linear trend analysis and Mann Kendall were used to establish trends. The findings indicate that smallholder farmers in the study area have noted reduced rainfall, increased temperature and reduced production as indicators of climate change. Results from archival data indicate insignificant decline of rainfall, significant increase of temperature and insignificant decline of crop yields at 5% significance level. As a response to these changes, smallholder farmers reported to use improved crop varieties, change planting dates, use intercropping, out-migrating and change land use practices. Several challenges were reported to hinder effective adaptation including inadequate capital, limited soft loans, limited weather information and deficient extension services. It is concluded that the climate is changing in the study area calling for strengthening farmers’ adaptive capacity. Keywords: Adaptive strategies, climate change effects, challenges, semiarid area, Tanzania.