ghanaopendata/ghanaian-research-english huggingface dataset:
Synthesis of Nickel Sulfide Thin Films and Nanocrystals from the Nickel Ethyl Xanthate Complex

Nickel sul des have unique and diverse structural features, making them ideal for energy conversion and storage. is research focuses on the synthesis and characterization of nickel sul de thin lms and nanocrystals from nickel ethyl xanthate complex using spin-coating and solventless methods. e nickel ethyl xanthate complex (C6H10S4NiO2) was characterized using Fourier transformed infrared (FT-IR), ultraviolet-visible (UV-Vis), and nuclear magnetic resonance (NMR) spectroscopies as well as thermogravimetric analysis (TGA). e NiS thin lms and nanoparticles were analyzed with energy dispersive X-ray (EDX) spectroscopy and X-ray di raction (XRD). Nickel ethyl xanthate was synthesized in an 81.2% yield. e bandgaps of the nickel sul de obtained from the spin-coating method ranged from 4.35–4.88 eV. For the solventless method, the bandgap of the nickel sul de ranged from 3.93–3.96 eV. e crystal phase observed from the spin-coating and solventless methods was α-NiS (hexagonal). A direct correlation was observed between annealing temperature, bandgap, and particle size

Source: KNUST
Synthesis of Lead Chalcogenide Nanoparticles and thin Films from Single-Source Precursors

The work described herein deals with the synthesis and characterisation of lead chalcogenide thin films and nanocrystals from Single-source precursors. Single-source precursors of type imidodiisopropyl –dithio, -diseleno and -thioselenophosphinato complexes of lead have been synthesised and characterised. The as-synthesised compounds have been used for the fabrication of lead sulphide and lead selenide thin films by aerosol-assisted chemical vapour deposition and for the synthesis of nanocrystals by colloidal hot injection method. The as- grown thin films and nanoparticles of lead sulphide and lead selenide have been characterised by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray (EDAX) analyses. Optical band gaps of the nanoparticles produced have been evaluated using the absorption spectrum fitting procedure. The band gaps of the nanoparticles were wider than those of their respective bulk particles, indicating a significant tuning. PbSxSe1-x thin films have also been prepared by aerosol assisted chemical vapour deposition (AACVD) using novel Single-source precursors synthesised, characterised and their structures elucidated in this project. The complexes are [Pb((SePiPr2)(SPiPr2)N)2], [Pb((SePiPr2)2N)(S2CNEt2)] and [Pb((SePiPr2)2N)(S2CNHexMe)]. The thin films deposited from all three complexes showed the formation of PbSxSe1-x at temperatures ranging from 300 °C to 400 °C and PbSe at 450 °C. Distribution of sulphur and selenium within alloyed thin films is confirmed by scanning electron microscope studies and EDAX analysis.

Source: KNUST
SYNTHESIS OF PURE AND MANGANESE DOPED ZINC OXIDE NANOPARTICLES BY A SOLUTION GROWTH TECHNIQUE: STRUCTURAL AND OPTICAL INVESTIGATION†

Pure and manganese doped zinc oxide nanoparticles have been successfully synthesized over the composition range, Zn1-xMnxO (0<x<0.5), by a solution growth process. The effect of Mn doping on the structure, morphology and optical properties were investigated by several techniques. X-Ray diffraction studies confirmed the formation of a single-phase polycrystalline hexagonal wurtzite structure of ZnO within the range, 0 < x < 0.3. No Mn related secondary phases were detected, within this range, which could be attributed to the fact that the dopant atoms had been well incorporated into the ZnO crystal lattice. For Zn1-xMnxO (x = 0.5), several low intensity peaks belonging to remnants of Manganese acetate were observed in the diffractogram, establishing a solubility limit for the synthesis technique used. The variation of d-spacing with Mn percent doping showed a very good agreement with Vergard’s law within the range (0<x<0.25). EDAX analysis of the nanoparticles was consistent with the formation of Mn doped ZnO. The optical band gap of the ZnO nanoparticles decreased linearly with increasing Mn percent doping, suggesting the possibility of tuning the band gap of ZnO by doping with Mn.

Source: KNUST
Synthesis of Pure and Manganese Doped Zinc Oxide Nanoparticles by a Solution Growth Technique: Structural and Optical Investigation

Pure and manganese doped zinc oxide nanoparticles have been successfully synthesized over the composition range, Zn1-xMnxO (0<x<0.5), by a solution growth process. The effect of Mn doping on the structure, morphology and optical properties were investigated by several techniques. X-Ray diffraction studies confirmed the formation of a single-phase polycrystalline hexagonal wurtzite structure of ZnO within the range, 0 < x < 0.3. No Mn related secondary phases were detected, within this range, which could be attributed to the fact that the dopant atoms had been well incorporated into the ZnO crystal lattice. For Zn1-xMnxO (x = 0.5), several low intensity peaks belonging to remnants of Manganese acetate were observed in the diffractogram, establishing a solubility limit for the synthesis technique used. The variation of d-spacing with Mn percent doping showed a very good agreement with Vergard’s law within the range (0<x<0.25). EDAX analysis of the nanoparticles was consistent with the formation of Mn doped ZnO. The optical band gap of the ZnO nanoparticles decreased linearly with increasing Mn percent doping, suggesting the possibility of tuning the band gap of ZnO by doping with Mn.

Source: KNUST
Synthesis and Interventive Performances of Alumina, Silica and their Complexes in Aflatoxin Adsorption In-Vitro

Aflatoxin contamination of foods is a major concern in the world especially in developing countries. Various binding agents have been used to deactivate aflatoxins in food. In this study, an experimental design using response surface methodology (RSM) was applied to develop a model in order to predict aflatoxin adsorption potential of alumina and silica complexes (ASC) in- vitro. The independent variables were amount of alumina (A: 20 to 60 %), silica (B: 40 to 80 %), heating time (0 to 4 h) and heating temperature (0 to 1400 oC) and the dependent variable was reduction in total aflatoxin. Design Expert was used in a combined D-optimal, quadratic x quadratic mixed process design to generate 28 runs for the experiment. The various complexes were screened against a stock solution of naturally contaminated peanuts with aflatoxin content of 456.3ppb in order to ascertain the adsorption capacity of the different alumina-silica complexes. The ANOVA and model fit test showed that aflatoxin adsorption by ASC is significant. All the non-heated samples of ASC showed percentage reduction of aflatoxin above 70 %. The micro graphical analysis of the samples of ASC also revealed the grains as having different size ranging from 154 μm to 490 μm. The predicted optimum conditions for the aflatoxin adsorption of ASC are combination of alumina and silica at a ratio of 32Al:68Si, heated at a temperature of 350 oC for 3 h.

Source: KNUST
Synthesis of magnesium oxide from waste magnesium-rich Cucurbita pepo (pumpkin) seeds

Recent studies have focused on the processing of biowaste to obtain added value and to reduce organic waste in the general stream. This study investigated the synthesis of magnesium oxide (MgO) from magnesium-rich Cucurbita pepo (pumpkin) seeds for a precursor solution as a reducing agent via an eco-friendly method for the first time. The pumpkin seeds were ashed at 550°C for 6 h and subjected to acid-leaching. Mg(OH) 2 M NaOH. The Mg(OH) 2 was then precipitated using an aqueous solution of 2.0 was then calcined at 550°C for 4 h to obtain MgO. Physicochemical properties (i.e. proximate analysis, elemental composition, electrical conductivity (EC), pH) and selected heavy metals (i.e. Pb, Fe, As, Cd, Cr, Hg, Cu, and Ni) analyses were conducted on the seed samples and as-synthesized MgO. X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier- transform infrared (FTIR), citric acid test (CAT), and acid neutralization capacity (ANC) tests were techniques used to characterize the synthesized MgO. The results revealed the percentage yield of the MgO to be 23%. The pH of the as-synthesized MgO was recorded as 10.63. XRF studies showed that MgO made up 75.1% of the total weight synthesized. XRD results showed the presence of crystalline cubic structures of MgO. FTIR results showed a peak at 584 cm −1 which confirmed the formation of MgO. The produced MgO was highly reactive, with a CAT time of 2 s. The ANC of the MgO was high at 22.77 mol + /kg. Also, metal concentrations such as Fe, Cu, Cd, Ni, Pb, Hg, As, and Cr in MgO were below the WHO stipulated limits of 350, 36, 0.8, 35, 85, 0.03, 40, and 100, respectively. This implies its suitability for soil remediation purposes. Results indicate that the as-synthesized MgO from Cucurbita pepo (C. pepo) seeds could be used for several applications due to its high alkalinity, reactivity, and fast CAT time.

Source: KNUST
Synthesis of zeolite from kaolin and the subsequent production of ceramic – zeolite water filter

The synthesis of zeolite from kaolin was performed and a low–cost, easy access ceramic water filter was produced. The zeolite used for the production of the filter was synthesized from kaolin. Two steps were used for the synthesis; thermal activation of the kaolin at 600 O C to get a dehydroxylated product called metakaolin (metakaolinization) and hydrothermal reaction of metakaolin in alkaline medium for crystallization of the zeolite (zeolitisation). For the hydrothermal transformation of the metakaolinite, NaOH solutions at 3, 4, 5 and 6 M concentrations were used at crystallization tempereature of 105 O C, over the reaction times; 3, 4, 5 and 6 hours. The transformed products were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and X-ray fluorescence (XRF). XRD spectra of the transformed metakaolinites showed a phase of zeolite LTA with a face-centered cubic crystal structure. SEM confirmed the cubic crystal structure of the zeolite and FTIR used the absorption band to confirm the sample as zeolite LTA. XRF data showed that the major elements present in the kaolin and zeolite were Al, Si, K and Fe. The minor elements were Mg, Ti, and Ca. The best synthesis condition for the transformation of the kaolin was optimized to obtain zeolite in bulk quantity which was then used to mold the candle filter, with addition of other clay. Some properties of the candle such surface area, thickness, turbidity removal, flow rate and coliform removal were tested and gave favourable results.

Source: KNUST
Synthesis of zeolites and their applications to removal of arsenic and ammonia–nitrogen from samples of contaminated water

The removal performance of arsenic and ammonia were investigated by adsorption process on Linde Type X (LTX), Low–Silica Type X and Linde Type A (LTA) zeolites. The zeolites were hydrothermally synthesized in the laboratory at 100oC 1oC. The synthesized zeolites were characterized by X-ray di raction (XRD), Scanning electron microscopy (SEM), Fourier-Transformed Infra-red spectroscopy and Thermogravimetric analysis (TGA). The removal capacity of arsenic, known to be a hazardous contaminant in drinking water that causes arsenical dermatitis and skin cancer, and ammonia, which can have deletrious e ects in water sources, were evaluated by adding 1.5 g and 0.8 g of zeolites to 100 ml and 50 ml of wastewater respectively for arsenic and ammonia removal. Removal e ciencies for Arsenic removal after treating for 30 minutes with adsorbents ranged between 67.86–81.35 % for LTX, 67.86–86.31 % for LSX and 71.87–96.00 % for LTA while removal e ciency of LTA for ammonia removal also ranged between 76.67–93.33 % and 86.15–90.77 % for treatment for 30 minutes (sample 1) and 60 minutes (sample 2) respectively. Langmuir and Freundlich isotherms were used in analysing results obtained from experimental studies. It was concluded that zeolites were e cient in removing arsenic and ammonia from contaminated water samples. The concentrations of arsenic and ammonia obtained after treatment were below the minimum contaminant levels as stipulated by the Ghana EPA. It is suggested that alternate methods like column and bed methods should be utilized to increase removal e ciencies and the use of local raw materials to synthesise the zeolites.

Source: KNUST
Synthesis, derivatization, characterization and anti-microbial screening of Azo compounds.

In our research group, two azo dyes were recently demonstrated to have antimicrobial activity. Structural modification of these compounds resulted in seven novel dyes. Five compounds were synthesised by the two-step diazotization-coupling reaction sequence. Employing the Williamson’s synthesis and acetylation with acetic anhydride, the ether and acetyl derivatives were synthesised respectively. The synthesised dyes, with good yields, have been characterised with IR, Mass Spec. and 1H NMR, and the melting point as well as retardation factor determined. The Broth Dilution method was used in determining the antimicrobial activity against the organisms, Staphylococcus aureus, Streptococcus pyrogenes, Salmonella typhi, Pseudomonas aeruginosa and Candida albicans. The synthesised compounds showed a broad spectrum of activity, with greater gram-negative and antifungal activity. The alkylated products, (E)-1-(4-ethoxynaphthalen-1-yl)-2-(4-nitrophenyl)diazene (KA 008), (E)-4-((4-ethoxynaphthalen-1-yl)diazenyl benzoic acid (KA 009) were the most active of all the compounds synthesised, with an MIC of 35.16µg/ml against P. aeruginosa and S. pyrogenes for KA 008 and 70.32 µg/ml against S. typhi and P. aeruginosa for KA 009. The acetylated derivatives showed the least activity against the test organisms. KA 008 also showed comparable activity against the standard Cefuroxime axetil used as the positive control.

Source: KNUST
Synthesis, molecular docking studies and ADME prediction of some new triazoles as potential antimalarial agents

The challenges concerning the control of malaria remain due to the continuous emergence of drug resistant strains. Over the years, the use, misuse, and abuse of antimalarials have created a conducive environment for the development of resistant Plasmodium falciparum strains. We herein report on the synthesis, characterization and antimalarial activity of a library of seven novel 1,2,3-triazoles as part of the drug discovery campaign against drug-resistant Plasmodium falciparum. The interactions of the triazoles with plasmepsin II, plasmepsin IV, falcipain-2 and the heme detoxifying protein-all key proteins of Plasmodium falciparum degradosequesterome (Dsq) were also investigated by molecular docking. The compounds 3a-d, 4–6 were synthesized by CuAAC click reaction in good to excellent yields of 73–98% and characterized by melting point, UVvisible, infrared and nuclear magnetic resonance (1H and 13C) and MS techniques. Compounds 3a-d displayed high in vitro potency (IC50s: 0.62–22.11 ug/ml) against the chloroquine-resistant Dd2 lab strain of Plasmodium falciparum and low toxicity (SI > 1 except compound 4) to human erythrocytes. Computational studies indicated that the compounds 3a-3d had an absorption of 76–91%, and they were category III acute oral toxins (LD50 from 500 to 5000 mg/kg). The molecular docking study suggests that compounds 3a-d interacted with plasmepsin IV and the heme detoxifying protein with high affinity and a moderate affinity for falcipain-2. Keywords: Antimalarial; Click reaction; Docking; Plasmodium falciparum; Triazoles

Source: KNUST
Synthesis: (a Project in Painting and Sculpture)

The artist sees the division of fine art into various disciplines as painting and sculpture often inhibiting fuller creative expressions. The project seeks to put painting and sculpture into one creative process. The artist advocates for a critical study of life and nature. He calls for the creation of an environmentally friendly atmosphere, by reviving and recreating what otherwise might have been thought of as decayed. The project also seeks to involve the spectator in the creative process. The works provoke the spectator to have new frontiers for the redefinition of painting and sculpture. The project was carried out against the background of what is known to exist in a contemporary art practice. Painting and Sculpture techniques are freely combined in the works. The report is presented in the following order: Introduction, which sets out purpose, scope and the experimental survey for the project. Chapter One recounts what other artists have accomplished in the area of combining painting and sculpture; construction, collage, and assemblage. Under Chapter two, one reads about the works and their relationship to life. Photographs of the works are shown after this chapter. The conclusion gives the spectators the freedom to interact with the works in relationship to their experiences in life.

Source: KNUST
Synthesis of Zeolites and their Application to the Desalination of Seawater

In this study, zeolite X and Y were synthesized hydrothermally in the laboratory at 90˚C and 100˚C respectively. The synthesized zeolites were characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), fourier transform infra-red spectroscopy (FTIR), EDX and thermogravimetric analysis. Exchange of Ca, Mg and K for Na ions in seawater were evaluated in Linde type X and Y. The desalination capacity of both zeolite X and Y were evaluated by adding 0.5 g and 1.0 g of each zeolite to 100 ml of seawater on a rotary shaker. The kinetics of desalination was carried by taking analyte samples at 10, 15, 30, 60, 90 and 120 minutes. The results obtained showed that zeolite mass to seawater ratio of 0.5:100 yielded higher removal efficiencies. Ion exchange was carried out at room temperature. Replacement of Na cations by Ca, K and Mg in the zeolite framework was noted. The overall ion exchange selectivity of both X and Y showed preference in the order of Ca > Mg> K > Na. Removal efficiencies obtained when zeolite X was used was Ca 81.5%, Mg 75%, K 59.9% and Na 11.5%. Efficiencies obtained in the case of zeolite Y was Ca 53.9%, Mg 38.5%, K 35.5% and Na 34.5%. Silver nitrate was used to reduce chloride ions and reduce electrical conductivity. It was concluded that zeolites are efficient in the desalination of seawater. The quality of water produced was not suitable for drinking. However, it can be used for irrigation and other industrial purposes. It is suggested that, to effectively desalinate seawater, zeolites without sodium will be appropriate. Also alternate methods like the Column method could be utilized.

Source: KNUST
Tabernacle of Witness Church International Complex, Kumasi

The Charismatic movement or churches can be said to be an epoch in the history of Christian church. It expresses that the church institution is as dynamic as human institution which are subject to changes. Current statistic on church attendance in Ghana reveals that the charismatic congregation apparently outnumbered the traditional churches despite their recent introduction in the religious scene. Further survey reveals that charismatic churches apart from some prominent ones have their congregation of the individual churches not exceeding 1,000 this is due to the proliferation of new charismatic church all over the country. These charismatic churches lay emphasis on the congregation’s participation and less emphasis on the minister. Praise and worship is expressive involving gesticulation and exuberant form. Tabernacle of witness church international is one of the fast growing charismatic churches in Ghana and has all the characteristics of a Charismatic church in terms of their history. Like all other Charismatic church TWCI is faced with constant mockery due in part to their inconvenient meeting place. The T.W.C.I is at the moment house in one of UAC’s building in Adum on the top floor of the structure.

Source: KNUST
The Sɩsaala Dirge: a Critical Analysis

This dissertation is a modest attempt at examining the literary and cultural backgrounds pertaining to the performance of the Sɩsaala dirge. The principal objective of the study is to pursue the aesthetic, cultural, moral, and socio-political evidence that the Sɩsaala dirge, like many Ghanaian dirges, does not only provide the appropriate platform for mourning the dead, but that it also poetically reiterates cultural, moral, social, artistic, and historical values. While the Sɩsaala dirge may be distinct from other local dirges in terms of how it is executed and who participates in its performance; and though its continuous rendition is faced with problems in the form of some negative influences from the Christian and Moslem religions, Western lifestyle, ignorance on the part of the Sɩsaala youth about the positive values of their dirges, lack of unity among poet-cantors, and the systematic disintegration of extended family values; it nonetheless celebrates national values such as respect for the aged, motherhood, motherliness, industriousness, moral correctness, and verbal creativity. These are values that transcend ethnic cultures and can therefore be used to further promote national unity and identity. Of equal importance is the ability of the dirge to serve as a medium for poet-cantors to pay homage to the “word”, and to further prove that “orality” is not the mere absence of writing but it is a system that is suis generis through which part of the trajectory of human development can always be traced.

Source: KNUST
TABOOS AND ENVIRONMENTAL CONSERVATION: A STUDY OF SOME AKAN COMMUNITIES.

According to the creation narrative, God created the world (environment) and then created man with a mandate to care for the environment and in turn benefit from it. Our ancestors were able to keep to this mandate and the environment together with mankind flourished. They established taboos that guided the use of natural resources to prevent its degradation. However, the same cannot be said of contemporary times where taboos are generally regarded as mere superstition and various human activities have led to the exploitation of the environment and the depletion of various natural reserves. Some schools of thought have argued that the reverence given to the concept of taboos in the past preserved the environment to a large extent. Hence, this research was conducted to investigate the nature and purpose of Akan taboos and how they have helped in the conservation of the environment over time. It also sought to ascertain the challenges that have impeded the relevance of the Akan taboos to environmental conservation in these modern times. The field study used a qualitative analysis that employed a phenomenological approach. It focused specifically on Amoakokrom in the Ahafo Ano South-East District and Akegyesu in the Amansie West District of the Ashanti Region of Ghana. Various interviews were conducted with key stakeholders of tradition in the selected areas. The study found out that, the Akan consider the environment as a support system for their lives and needs to be safeguarded. Also from the field findings, it was deduced that any order that needs total compliance from the community was made in the form of taboos. This is because the taboos often put fear in the people because of their related punishment hence most people complied. The research concluded that the Akan taboos have been an asset in environmental conservation and need to be promoted and emulated by other traditional societies to help ensure sustainable growth for national development.

Source: KNUST