Non-linear Effect of Socio-spatial features on academic performances of HND Statistics students of the Federal Polytechnic Ado-Ekiti

Students’ performances worldwide is a phenomenon that attracts researches since education is considered to be a tool to social and economic advancement of a nation as well as its citizenry. Nigeria situation in the recent time has been considered critical. Many earlier works have shown a general agreed decline in education while that decline has equally been attributed to ranging factors; primary and secondary schools were said to be shambles, while these underperforming schools are mainly considered as public or government school in Nigeria due to many social and economic downturns that are not the subject of this research. An attempt is made in this research work to delve into the general performances of students in higher institution using the the higher national diploma (HND) results of Statistics students of the Federal Polytechnic Ado-Ekiti to examine the context of spatial study, the contribution of factors such as sex (peer effect), state, primary and secondary school type attended as well as the ages of students. Tests show significant effect of the variables and further investigation reveal higher influence between performance and type of primary school attended, however positive relationship declined for secondary school attended. The graphical illustration shows that age is found to have a non-linear influence on the academic performances. Keywords: Students, school attended, age, significant effect, performance

Phase and microstructural evolution during sintering of mixture of 75:25 Nigerian kaolin and calcined alumina powder compacts

The microstructure progression of a uniformly mixed 75 wt% of Nigerian sources of kaolinite clay powder and 25 wt% finer grade of calcined alumina powder (d50) of 6 - 8 mμ was investigated in this present work. The hydraulically compact samples of the mixture were heated in the temperature range of 1400 – 1600 oC and their physical mechanical properties were evaluated. It was observed that 1400 and 1500 oC heated samples did not show any major densification and resulted in higher apparent porosity in the range of 26 - 28%. The samples heated at 1600 oC shows improved densification with significant reduction in apparent porosity (< 5.0%). The phase and microstructural evolution during heating of the samples were studied using XRD and SEM/EDAX technique. The results revealed the presence of quartz (SiO2) and mullite (3Al2O3.2SiO2) as major phases and corundum (Al2O3) as minor phase in the 1400 oC heated samples while mullite, corundum as major and quartz as minor phases were identified in the 1600 oC heated samples. The Fe2O3 present in the clay promoted the growth of the size of mullite needles. Due to the development of a largely dense compact microstructure at 1600 oC, the flexural strength improved significantly to 45 MPa from 15 MPa obtained at 1400 – 1500 oC. The aspect ratio of mullite crystals is higher in 1600 oC heated samples compared to 1500 oC heated speci

Evaluation of Nigerian Source of Kaolin as a Raw Material for Mullite Synthesis

In the present study, a new source of kaolinitic clay (Al2O3.2SiO2.2H2O) collected from Abule Onikosin Road in Abeokuta area of Ogun State, Nigeria was first processed to remove the stony materials adhered to its surface and subsequently characterized with respect to its chemical analysis, TG-DTA, particle size spectrum and identification of mineralogical phases by XRD technique. The identified endothermic peak at 516.39oC for dehydroxylation in the DTA curve and observed deformed XRD profile confirm that the clay belongs to disordered kaolinitic clay. The high SiO2 content (59.26 wt%) compared to theoretical value (46.54 wt%) of well-ordered kaolinite is due to excess silica and this has been revealed in XRD pattern as quartz peak. The compact samples of this processed clay powder on heating in the temperature range of 1400-1600oC resulted almost densified and impervious sample at 1600oC. The densification occurred by viscous flow mechanism. Silica together with impurity oxides (Fe2O3, TiO2) in the clay forms glassy phase in the above temperature range and that accompany the formation of mullite (3Al2O3.2SiO2) crystals. The XRD and FESEM studies conducted on heated samples revealed the formation of mullite needle, the amount and aspect ratio of which increases with increase in heating temperature. The EDAX studies confirm the presence of Al, Si, O as major elements which also support mullite formation in the heated compact samples. This new sources of kaolinitic clay identified in Nigeria is found to be suitable for mullite synthesis and it is advantageous due to its low temperature mullitization unique microstructure

Synthesis strategies and application of ternary quantum dots— in cancer therapy

Semiconductor nanoparticles also known as quantum dots (QDs) have continued to receive more attention from researchers due to their unique optical, magnetic and photo physical properties which made them useful as biomedical materials, solar cells, catalyst etc. However, ternary I-III-VI QDs have shown to be a safer alternative to the binary II-VI or IV-VI QDs due to the absent of heavy toxic elements such as Cd and Pb. Cancer management and therapy in Africa has been bedeviled by a lot of challenges such as inaccurate diagnosis and ineffective therapeutic methods. Therefore, the need to develop an appropriate approach for cancer detection and treatment is of paramount importance. Tunable optical properties and absorption in the near infra-red region of the ternary QDs makes them useful as fluorescent probes in cancer detection and treatment. They have the ability to detect specific cancer cells including those that are not easily detected by modern imaging technique. Also, properties such as non-bleaching, stability, water solubility etc. made them a desirable fluorophore when compared to conventional dyes. Most cancer drugs suffer from inherent shortcomings such as limited absorption, insolubility and aggregation. However, these shortcomings can be overcome when these drugs are applied in form of conjugated systems. The use of QDs as conjugates has revolutionize the treatment of cancer in the 21st century. This review provides information about the synthesis strategies, optical properties, hydrophilization and bioconjugation of ternary I-III-VI QDs. Furthermore, we described the various biomedical applications in biosensors, bioimaging, drug delivery and phototherapeutic techniques. Finally, we looked at the challenges and future perspective of these QDs in cancer management. Keywords: Ternary QDs, drug delivery, biosensors, hydrophilization, bioimaging, bioconjugat

Assessment Of Polycyclic Aromatic Hydrocarbons In Locally Smoked Fish Sold In Lagos Markets

Polycyclic aromatic hydrocarbons (PAHs) are known widespread contaminants which represent an important group of carcinogens. This study reports the concentrations of PAHs in smoked fishes locally sold in two markets in Lagos state, Nigeria. The amounts of PAHs present in the samples were quantified using gas chromatography coupled with flame ionization detector (GC-FID). The total concentration of PAHs detected in each sample are 127.5, 86.06, 58.39 and 101.58 μg/kg dry weight for the following fish species respectively; Scomberomorus tritor, Tilapia guinensis, Ilisha africana and Clarias gariepinnus. Benzo[a]pyrene was present in all the samples and the concentration exceeds the permissible limit of 5.0 μg/kg except in one of the fish species. The abundance of high molecular weight PAHs in three of the fish species suggests that pyrolysis was the method used in the smoking process. From the maximum limit set by the European Commission for the sum of PAH, only S. tritor exceeded the 30 μg/kg limit with 54.68 μg/kg present

Influence of transition metal ion (mn4+) on mullite formation in a mixture of 50:50 Nigerian kaolin and calcined alumina

In the present investigation, 5 wt% chemical grade MnO2 was added in a mixture of 50:50 Nigerian sources of kaolin and superfine calcined alumina powder and effect of this transition metal ion on their physico-mechanical properties, phase and microstructural evolution were studied during heating in the temperature range of 1,400–1,650°C. The heated samples were found to be highly porous (>30%) in this entire temperature range. The doping of 5 wt% MnO2 in this mixture did not improved the densification, but resulted into higher flexural strength (26 MPa) at 1,400°C compared to 7 MPa in the undoped sample. At 1,650°C, the reverse trend was observed, the flexural strength of undoped sample was found to be higher (38 MPa) than doped sample (27 MPa). The XRD study revealed the formation of mullite as major and corundum as minor phases in both the samples. The microstructural study shown the presence of needle shaped mullite crystals and corundum grains. The presence of inter-granular and intra-granular pores in MnO2 doped samples might have reduced the strength at 1,650°C. The aspect ratio of mullite needle at 1,650°C was found to be higher in doped sample. The theoretical and experimental value of >4 for MnO2 ion has been validated

The effect of MgO and Cr2O3 on mullite formation from Nigeria sourced kaolin-calcined alumina sintered compacts

Mullite being one of the most important aluminosilicate materials has a lot of unique properties and industrial applications. Hence the need to produce via cheap and available starting materials is paramount. In this present study, mullite was synthesized from sintering of Nigerian sourced kaolin–alumina (high purity from Almatis) after reacting samples have been mixed in a high speed ball milling machine in the presence of MgO and Cr2O3 additives. The samples were uniaxially pressed in a mould to form compact and sintered at temperature of 1400-1600°C. Bulk density, apparent porosity, and modulus of rupture were investigated as a function of sintering temperature and presence of dopant. Microstructural studies using scanning electron microscope (SEM) and X-ray diffraction (XRD) studies were carried out on the kaolin-alumina sintered compacts. Results from the study indicate that mullite was successfully synthesized, as XRD pattern showed the presence of mullite as major phases at 1600°C without any trace of cristobalite (unreacted silica) or quartz. SEM studies showed the presence of needle-shaped mullite. The doped samples showed little improvement in the physico-mechanical properties of the aggregate. However, the degree of mullitisation for the doped samples at 1600°C far exceeds that of the undoped samples. Cr2O3 doped has 94.48% mullitisation while MgO has 79.96% mullitisation. The undoped sample has 59.19% degree of mullitisation. MgO doped was better densified

Adsorption properties of Azadirachta indica extract on corrosion of Aluminium in 1.85 M Hydrochloric acid

The crude extract of Azadirachta indica was used in the corrosion inhibition study of aluminium metal coupons in 1.85 M hydrochloric acid environment by gasometric technique. The coupons were immersed in test solutions of uninhibited 1.85 M HCl and those containing extract concentrations of 10%, 20%, 30%, 40% and 50% (v/v) at room temperature. The rate of the reaction was captured by monitoring the volume of hydrogen gas evolved as a result of the interaction. The inhibition efficiency of the extracts and the adsorption isotherm of the process were calculated using Frumkin, Freundlich, Langmuir and Temkin adsorption theories and the surface morphology studied using Scanning Electron Microscopy (SEM). It was observed that the plant extract retarded the acid induced corrosion of aluminium and the volume of hydrogen gas evolved reduced with increasing extract concentration. The adsorption studies revealed that Langmuir isotherm is the best model for the adsorption of Azadirachta indica (R2 = 0.999) on aluminium surface. This implied that the Azadirachta indica extracts with aluminium metal undergoes chemisorption

Synthesis strategies and application of ternary quantum dots—in cancer therapy

Semiconductor nanoparticles also known as quantum dots (QDs) have continued to receive more attention from researchers due to their unique optical, magnetic and photo physical properties which made them useful as biomedical materials, solar cells, catalyst etc. However, ternary I–III–VI QDs have shown to be a safer alternative to the binary II–VI or IV–VI QDs due to the absent of heavy toxic elements such as Cd and Pb. Cancer management and therapy in Africa has been bedevilled by a lot of challenges such as inaccurate diagnosis and ineffective therapeutic methods. Therefore, the need to develop an appropriate approach for cancer detection and treatment is of paramount importance. Tunable optical properties and absorption in the near infra-red region of the ternary QDs makes them useful as fluorescent probes in cancer detection and treatment. They have the ability to detect specific cancer cells including those that are not easily detected by modern imaging technique. Also, properties such as non-bleaching, stability, water solubility etc. made them a desirable fluorophore when compared to conventional dyes. Most cancer drugs suffer from inherent shortcomings such as limited absorption, insolubility and aggregation. However, these shortcomings can be overcome when these drugs are applied in form of conjugated systems. The use of QDs as conjugates has revolutionise the treatment of cancer in the 21st century. This review provides information about the synthesis strategies, optical properties, hydrophilization and bioconjugation of ternary I–III–VI QDs. Furthermore, we described the various biomedical applications in biosensors, bioimaging, drug delivery and phototherapeutic techniques. Finally, we looked at the challenges and future perspective of these QDs in cancer management

Equilibrium Studies of the Reaction of Turkey (Meleagris gallopavo) Haemoglobin Sulphydryl Groups with 5,5′-dithiobis(2-nitrobenzoate): Tertiary Conformational Change in Turkey Haemoglobin Induced by Inositol hexakisphosphate

The red blood cell of turkey contains two haemoglobin types, major and mi-nor components. In the present study, the equilibrium constant, Kequ, for the reaction of 5,5′-dithiobis(2-nitrobenzoate), DTNB, with the sulphydryl group of the major turkey aquomethaemoglobin was determined at 25°C as a function of pH. Kequ varies by about 2 to 3 orders of magnitude between pH 5.6 and 9.0 for both haemoglobin [stripped and in the presence of inositol hexakisphosphate (inositol-P6)]. Calculations from the pH dependence of Kequ showed that in the r ⇌ t tertiary conformational transition of aquomethae-moglobin, the t isomer population was 0.26 %. In the presence of inositol-P6, the t isomer population increased to 9.08 %. The results showed that while inositol-P6 increased the relative population of the t tertiary conformation by changing the relative distribution of two protein conformations, it had no effect on Kequ. The effect of Inositol-P6 on the nature and number of groups linked to the DTNB reaction was also determined