Polyaniline-tin(IV) molybdophosphate composite exchanger: Photocatalytic behavior and antibacterial activitiy

ABSTRACT. Polyaniline-tin(IV)molybdophosphate composite exchanger was prepared using sol–gel method by mixing polyaniline gel into the inorganic precipitates of tin(IV)molybdophosphate. The composite ion exchanger was characterized by various techniques such as XRD, UV-Vis, FTIR, SEM-EDX, and PL. Photocatalytic activities and antibacterial efficiencies of the bare polymer polyaniline (PANI), the inorganic exchanger tin(IV)molybdophosphate (TMP) and the composite polyaniline-tin(IV)molybdophosphate (PANI-TMP) were evaluated using methylene blue (MB) dye as a model organic pollutant and Gram negative and Gram positive bacteria as test microbes, respectively. Photocatalytic and antibacterial activities of polyaniline[1]tin(IV)molybdophosphate composite was found to be higher than that of organic (polyaniline) and inorganic (tin(IV)molybdophosphate) counterparts. The results obtained indicated the degradation efficiency of approximately 73% in 180 min exposure time. Effect of scavengers study evidenced the most important species in the degradation process to be (·O2 - ) and (·OH). Highest photocatalytic degradation efficiency for the composite exchanger studied was obtained at initial concentration of 10 mg/L MB, 100 mg/L of catalyst load and a pH of 8. Antibacterial efficiency of the exchanger over both Gram negative and Gram positive bacteria was found to be higher than the single counterparts. KEY WORDS: Ion exchangers, Antimicrobial activity, Composites, Photocatalysis, Polyaniline Bull. Chem. Soc. Ethiop. 2023, 37(1), 59-76.                                                                  DOI: https://dx.doi.org/10.4314/bcse.v37i1.6                                                                                                      &nbsp

Fe–Al binary oxide nanosorbent: Synthesis, characterization and phosphate sorption property

Phosphorous removal using efficient treatment approach such as adsorption is vital for the control of eutrophication. In this study, nanosized Fe-Al binary oxide sorbent was synthesized through a modified gel evaporation method and employed for adsorption of phosphate from aqueous system. The nanosorbent was characterized by x-ray diffraction (XRD), scanning electron microscope coupled with energy dispersive x-ray spectroscopy (SEM/EDX), tunneling electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and flame atomic absorption spectroscopy (FAAS). Langmuir model showed the best fit to the experimental data with a maximum adsorption efficiency of 16.4 mg/g. Having all parameters optimized, it has been found that the nanosorbent exhibited 99.86% phosphate adsorption efficiency. The effect of co-existing anions on the adsorption of phosphate was also studied and no significant effect on the efficiency of the nanosorbent was observed due to competing ions such as fluoride. Desorbabilty of phosphate was investigated and found to be increased with increasing pH. The results of thermodynamic studies indicated that the process is spontaneous and endothermic. Both macroscopic and microscopic approaches were employed to predict the mechanism of phosphate adsorption on the Fe-Al binary oxide nanosorbent. Accordingly, the phosphate adsorption is presumed to occur via the replacement of surface hydroxyl groups by the phosphate species and formation of inner-sphere surface complexes at the water/oxide interfac

Context and Considerations for the Development of Community-Informed Health Communication Messaging to Support Equitable Uptake of COVID-19 Vaccines Among Communities of Color in Washington, DC.

BACKGROUND: Communities of color have been disproportionately impacted by COVID-19. We explored barriers and facilitators to COVID-19 vaccine uptake among African American, Latinx, and African immigrant communities in Washington, DC. METHODS: A total of 76 individuals participated in qualitative interviews and focus groups, and 208 individuals from communities of color participated in an online crowdsourcing contest. RESULTS: Findings documented a lack of sufficient, accurate information about COVID-19 vaccines and questions about the science. African American and African immigrant participants spoke about the deeply rooted historical underpinnings to their community\u27s vaccine hesitancy, citing the prior and ongoing mistreatment of people of color by the medical community. Latinx and African immigrant participants highlighted how limited accessibility played an important role in the slow uptake of COVID-19 vaccines in their communities. Connectedness and solidarity found were found to be key assets that can be drawn upon through community-driven responses to address social-structural challenges to COVID-19 related vaccine uptake. CONCLUSIONS: The historic and ongoing socio-economic context and realities of communities of color must be understood and respected to inform community-based health communication messaging to support vaccine equity for COVID-19 and other infectious diseases

Integrated landscape management: Africa RISING R4D experiences in the Ethiopian highlands

United States Agency for International Developmen

Assessing and augmenting SCADA cyber security: a survey of techniques

SCADA systems monitor and control critical infrastructures of national importance such as power generation and distribution, water supply, transportation networks, and manufacturing facilities. The pervasiveness, miniaturisations and declining costs of internet connectivity have transformed these systems from strictly isolated to highly interconnected networks. The connectivity provides immense benefits such as reliability, scalability and remote connectivity, but at the same time exposes an otherwise isolated and secure system, to global cyber security threats. This inevitable transformation to highly connected systems thus necessitates effective security safeguards to be in place as any compromise or downtime of SCADA systems can have severe economic, safety and security ramifications. One way to ensure vital asset protection is to adopt a viewpoint similar to an attacker to determine weaknesses and loopholes in defences. Such mind sets help to identify and fix potential breaches before their exploitation. This paper surveys tools and techniques to uncover SCADA system vulnerabilities. A comprehensive review of the selected approaches is provided along with their applicability

AfriSenti: A Twitter Sentiment Analysis Benchmark for African Languages

Africa is home to over 2000 languages from over six language families and has the highest linguistic diversity among all continents. This includes 75 languages with at least one million speakers each. Yet, there is little NLP research conducted on African languages. Crucial in enabling such research is the availability of high-quality annotated datasets. In this paper, we introduce AfriSenti, which consists of 14 sentiment datasets of 110,000+ tweets in 14 African languages (Amharic, Algerian Arabic, Hausa, Igbo, Kinyarwanda, Moroccan Arabic, Mozambican Portuguese, Nigerian Pidgin, Oromo, Swahili, Tigrinya, Twi, Xitsonga, and Yor\`ub\'a) from four language families annotated by native speakers. The data is used in SemEval 2023 Task 12, the first Afro-centric SemEval shared task. We describe the data collection methodology, annotation process, and related challenges when curating each of the datasets. We conduct experiments with different sentiment classification baselines and discuss their usefulness. We hope AfriSenti enables new work on under-represented languages. The dataset is available at https://github.com/afrisenti-semeval/afrisent-semeval-2023 and can also be loaded as a huggingface datasets (https://huggingface.co/datasets/shmuhammad/AfriSenti).Comment: 15 pages, 6 Figures, 9 Table

Ensemble-based multi-filter feature selection method for DDoS detection in cloud computing

Widespread adoption of cloud computing has increased the attractiveness of such services to cybercriminals. Distributed denial of service (DDoS) attacks targeting the cloud’s bandwidth, services and resources to render the cloud unavailable to both cloud providers, and users are a common form of attacks. In recent times, feature selection has been identified as a pre-processing phase in cloud DDoS attack defence which can potentially increase classification accuracy and reduce computational complexity by identifying important features from the original dataset during supervised learning. In this work, we propose an ensemble-based multi-filter feature selection method that combines the output of four filter methods to achieve an optimum selection. We then perform an extensive experimental evaluation of our proposed method using intrusion detection benchmark dataset, NSL-KDD and decision tree classifier. The findings show that our proposed method can effectively reduce the number of features from 41 to 13 and has a high detection rate and classification accuracy when compared to other classification techniques

Global estimates on the number of people blind or visually impaired by cataract: a meta-analysis from 2000 to 2020

Background: To estimate global and regional trends from 2000 to 2020 of the number of persons visually impaired by cataract and their proportion of the total number of vision-impaired individuals. Methods: A systematic review and meta-analysis of published population studies and gray literature from 2000 to 2020 was carried out to estimate global and regional trends. We developed prevalence estimates based on modeled distance visual impairment and blindness due to cataract, producing location-, year-, age-, and sex-specific estimates of moderate to severe vision impairment (MSVI presenting visual acuity &lt;6/18, ≥3/60) and blindness (presenting visual acuity &lt;3/60). Estimates are age-standardized using the GBD standard population. Results: In 2020, among overall (all ages) 43.3 million blind and 295 million with MSVI, 17.0 million (39.6%) people were blind and 83.5 million (28.3%) had MSVI due to cataract blind 60% female, MSVI 59% female. From 1990 to 2020, the count of persons blind (MSVI) due to cataract increased by 29.7%(93.1%) whereas the age-standardized global prevalence of cataract-related blindness improved by −27.5% and MSVI increased by 7.2%. The contribution of cataract to the age-standardized prevalence of blindness exceeded the global figure only in South Asia (62.9%) and Southeast Asia and Oceania (47.9%). Conclusions: The number of people blind and with MSVI due to cataract has risen over the past 30 years, despite a decrease in the age-standardized prevalence of cataract. This indicates that cataract treatment programs have been beneficial, but population growth and aging have outpaced their impact. Growing numbers of cataract blind indicate that more, better-directed, resources are needed to increase global capacity for cataract surgery.</p