Physico-chemical parameters of soil in some selected dumpsites in Zaria and its environs

Physico-chemical parameters of soil were found to have influence on the availability of heavy metals in plants. pH values recorded in the control site ranges from 7.8 to 9.2 indicating that all the soils studied were alkaline. The control site has a value of 7.16. The conductivity values range from 4.2 x 10-2 to 4.0x105μScm-1 . The highest conductivity value was recorded in site B, while site D had the least value. Moisture content in the 10 dumpsites studied ranged from 17.87 to 82.49%. Organic matter contents in the dumpsites ranged from 3.20 to 5.30% and are higher than values obtained for uncontaminated/control site. These higher values may be due to the aging of the dumpsites. The cation exchange capacity values ranged from 132.83(R) to 469.5(G)CmolKg-1. These values are reasonably high due to the relatively higher conductivity values obtained in the dumpsites and this may also affect the bioavailability of the heavy metals in plants. Correlation analysis revealed that pH, electrical conductivity and moisture content were negatively correlated.Keywords: Bioavailability, dumpsite, heavy metal, physico-chemical parameter, Zari

Preparation and Application of Polyvinyl Alcohol Based UV Curable Flexographic Printing Ink

Polyvinyl alcohol was utilized as a single sole binder in the formulation of water based UV curable flexographic printing inks. Six different formulation composition containing 2%, 3%, 4%, 5%, 8% and 10% polyvinyl alcohol were prepared using 1-(4-nitrophenyl)azo-2-naphthol as pigment and potassium dichromate as a cross linking agent. The formulations prepared were characterized for viscosity and FT-IR before being printed on different substrates. The integrity and pigment particle distribution of the ink film formed were assessed by optical microscopy, the print quality and fastness properties were found to meet most requirements in colour printing chemistry and technology applications

Vulnerability prediction for secure healthcare supply chain service delivery

Healthcare organisations are constantly facing sophisticated cyberattacks due to the sensitivity and criticality of patient health care information and wide connectivity of medical devices. Such attacks can pose potential disruptions to critical services delivery. There are number of existing works that focus on using Machine Learning(ML) models for pre-dicting vulnerability and exploitation but most of these works focused on parameterized values to predict severity and exploitability. This paper proposes a novel method that uses ontology axioms to define essential concepts related to the overall healthcare ecosystem and to ensure semantic consistency checking among such concepts. The application of on-tology enables the formal specification and description of healthcare ecosystem and the key elements used in vulnerabil-ity assessment as a set of concepts. Such specification also strengthens the relationships that exist between healthcare-based and vulnerability assessment concepts, in addition to semantic definition and reasoning of the concepts. Our work also makes use of Machine Learning techniques to predict possible security vulnerabilities in health care supply chain services. The paper demonstrates the applicability of our work by using vulnerability datasets to predict the exploitation. The results show that the conceptualization of healthcare sector cybersecurity using an ontological approach provides mechanisms to better understand the correlation between the healthcare sector and the security domain, while the ML algorithms increase the accuracy of the vulnerability exploitability prediction. Our result shows that using Linear Regres-sion, Decision Tree and Random Forest provided a reasonable result for predicting vulnerability exploitability

Theoretical study of aspartic and glutamic acids as corrosion inhibitors on aluminium metal surface

The present study describes the inhibition of aluminium corrosion using amino acids including aspartic and glutamic acids through computational studies. Quantum chemical approach was used to calculate some electronic properties of the molecules to ascertain the correlation between inhibitive effect and molecular structure of the inhibitors. The corrosion inhibition efficiencies of these molecules and the global chemical reactivity was established through some parameters, such as EHOMO, ELUMO, energy gap (∆E), electronegativity (χ), global hardness (η), and the fraction of electrons transferred from the inhibitor molecule to the aluminium metallic atom (∆N). In addition, the local reactivity has been analyzed through the Fukui function and condensed softness indices. The molecular dynamic method results showed that the more negative the binding energy of the inhibitor-metal surface is, the better the adsorption of the inhibitor onto the metal surface and subsequently the higher the inhibition. The trend could be inferred in terms of inhibition efficiencies of the inhibitors in respect of their binding energies as glutamic acid greater than aspartic acid

Volumineux Mélanome Malin De La Conjonctive Multi Récidivant À Propos d’un Cas

Melanoma of the conjunctiva is a tumor that develops from the conjunctival melenocytes. It often reoccurs even after several surgical removals. The authors present the case of a 45 years old woman who was at first seen in our outpatient clinic with a spitz naevus of the conjunctiva of the right eye since more than 20 years ago. This naevus which was excised twice and then the eye enucleated underwent malignant transformation into a voluminous multi-recidivant malignant melanoma weighing after surgical removal 350g and measures 6x12x5cm

DFT and PM3 Computational Studies of the Reaction Mechanism of the Oxidation of L-Tyrosine by Iodine in the Gas Phase

- The oxidation of L-Tyrosine by molecular iodine was studied using semi-empirical and density functional theory methods. Molecular information such as net charges, values of frontier orbital energies, composition, proportions and bonding contribution were obtained and analyzed. Thus, possible reactive sites were proposed and the reaction mechanism was postulated. The postulated transition states, intermediates and products were also computed using the PM3 and DFT methods. Computed enthalpies of the oxidation reaction at standard conditions for the PM3 and DFT calculation were 216.97 kJ/mol and -36327404.72 kJ/mol respectively. The calculated ΔGo andΔSo, for the transition states according to the DFT model were both large and negative indicating that the processes were exergonic associative substitution reactions

Phytoremediation of Contaminated Soil Using Maize (Zea mays) and Mycorrhiza Inoculation

The phytoextracting capacity of maize (Zea mays) on soil contaminated with brewery waste was determined. The method used was based on the responses of the maize plants grown on four different soils (inoculated and uninoculated, with and without brewery waste) tagged M+B+, M-B+, M+B- and M-B-. These were analysed for mid-rib growth, neurosis, and heavy metals uptake in the plant in addition to soil and pH analysis. Results showed that maize (Zea mays) planted on soil of type M+B+ had a rapid increase in mid-rib size (55.3cm) while the plant grown on the control sample had the lowest size (47.0cm). There were initial increases in plant with neurosis in the inoculated samples which either stabilised or increased while the number in the uninoculated samples reduced with time. The plants grown on inoculated soil had greater heavy metal uptakes of 54–83% except for Cd where the uptake was 33–40% while those grown on uninoculated soil had metal uptakes of 19–52% except for Zn where the uptake was 80–81%. The investigation concluded that maize has the capacity of removing heavy metals from brewery waste and suggested revegetation of the soil to reduce wind and water erosions. &nbsp

ABSORBENT MIXTURES OPTIMIZATION FOR COD AND AMMONIA NITROGEN REDUCTION IN STABILIZED LEACHATE

This paper describes the optimisation of mixed media for Chemical Oxygen Demand (COD) and Ammonia Nitrogen (NH3-N) removal from stabilised leachate by feldspar (FE), zeolite (ZE), activated carbon (AC), and cockle shells (CS) mixtures using D-optimal mixture design. Linear equations characterised the optimal mixture. The optimum mitigation of COD and NH3-N in landfill leachate was favourable at 12.5 mg/L, 9.72 mg/L, 6 mg/L, and 11.79 mg/L of adsorbent mixed dosage for FE, ZE, AC, and CS, respectively, with the desirability value of 0.886. The predicted R-squared values for NH3-N (0.9839) and COD (0.8972) were in close agreement with the adjusted R-squared values of 0.9940 and 0.9900 for COD and NH3-N, respectively, which validates the obtained regression models. The Lack of Fit F-values of 0.6015 (COD) and 0.4565 (NH3-N) are insignificant, indicating that the models accurately predict the removal. The Fourier transform infrared spectroscopy (FTIR) revealed that the predominant hydroxyl group consisted of –OH at spectra 3306.18 and 3338.74. The study also revealed that the D-optimal mixture design has extremely high application potential as it produces a good mixture design based on the remediation of contaminants from stabilised leachate

Thermodynamics and Kinetics of Spiro-Heterocycle Formation Mechanism: Computational Study

Reaction mechanism among indoline-2,3-dione, pyrrolidine-2-carboxylic acid and (Z)-2-(1-(2-hydroxynaphthalen-1-yl)ethylidene) hydroxy-carboxamide to form 1'-((((aminooxy)carbonyl)amino)methyl)-2'-(1-hydroxynaphthalen-2-yl)-2'-methyl-1',2',5 ',6',7',7a'-hexahydrospiro[indoline-3,3'-pyrrolo[1,2-a]imidazole-2-one was investigated using density functional theory (DFT) at B3LYP level of theory. The three-step reaction occurred via five stationary points, including two van der Waals complexes (1 and 2), two intermediates and one transition state. The entropy change across the various steps indicated an appreciable interaction or overlap within the reacting molecules. This was also evident in variations in the geometries of the optimized species as the reaction progressed from the intermediates through the transition state to the final product. The steps leading to the formation of van der Waals complexes (1 and 2) were thermodynamically feasible in contrast to the bimolecular transition step. From the equilibrium constant value, the transition step was found to be the ratedetermining step. The study is able to provide information on the energetics of the individual step of the reaction and the overall process in addition to change in geometries as the initial reacting molecules transformed through the saddle points to the final product

PROJECTION OF CRITERIA AIR POLLUTANTS EMISSION FROM ON-ROAD VEHICLES IN THE MEGACITY OF LAGOS, NIGERIA

The increase in the mode of transportation has become a serious environmental threat that has resulted in the emission of criteria air pollutants (CAPs) into the atmosphere. These CAPs are sulphur oxides (SOx), particulate matter (PM), lead (Pb), carbon monoxide (CO), and nitrogen oxides (NOx). This study examined the emission of CAPs from road traffic use in Lagos State. Data for the inventories of the production of these five sources were taken from 1997–2011 and were used to forecast CAPs emissions from 2012–2030. The petroleum products consumption data were sourced from the Nigerian National Petroleum Corporation (NNPC). Five categories of CAPs were studied and their corresponding emissions from 1997–2011 were computed as follows: SOx: 209–15,358t, NOx: 2,038–25,692t, CO: 24,996–186,202t, PM: 155–995t, Pb: 0.8 4.5t. Projection and forecasting of CAPs emissions from 2012 to 2030 were carried out using the Box Jenkins ARIMA method. There were close similarities between the observed and forecast values. The predicted CAPs emissions between 2012 to 2030 will be 309t for SOx, 22,600 – 41,300t for NOx, 100,000 – 300,000t for CO, 414t for PM, and 0.7t for Pb. The study concluded that there is tendency for these CAPs emissions to increase if the authorities and stakeholders do nothing. Several mitigation measures aimed towards reducing future CAPs emissions in Lagos State were recommended for the various sources