Enzymatic pretreatment of grey cotion fabric for improving dye uptake, lustur and hand feel using fungal cellulase

Cellulase enzyme was extracted from pineapple peel substrate using Aspergiluss niger.  Because enzymes are sustainable alternatives to harsh toxic chemicals used in the Textile Industries. Cotton fabrics were treated with cellulase at variable concentrations at a pH of 5.5 and 55°C. Changes in various properties of the treated fabrics like weight loss, lusture, soft touch and overall dyeing properties were investigated. The results obtained show that cellulase have successfully removed staple fibres from the fabrics and thus, yield a glabrous appearance and soft touch of the treated fabrics; furthermore, it was established that percentage dye uptake and fastness properties of the fabrics were greatly improved as confirmed by the FTIR spectral analysis and UV- visible spectrophotometric analysis of the absorbance maximum of the dye liquor before and after dying.Key Words: Cellulase, Aspergillus niger, pre- treatment, cotton fabric and dye uptake

Comparative study of performance of shoe polishes formulated from polyethylene and carbon black (C. I. Black pigment 7)

Polyethylene pigment was generated from “pure water sachets” (one of the major environmental nuisance today) and used in the formulation of shoe polish using paraffin wax, white spirit, turpentine oil, and nitrocellulose. The polish was found to exhibit similar wrinkle resistance, inferior gloss, rub resistance; resistance to fading and dust absorption resistance comparable to the one formulated from carbon black pigment. Polyethylene polish like the one formulated using carbon black pigment was found to be fairly well comparable with some commercial shoe polishes in most of the parameters evaluated.Keywords: Polish, Carbon, Resistance, Paraffi

Numerical Analysis of Defects Caused by Thermolysis in an Infinite Cylindrical Ceramic Moulding

The second-order parabolic (diffusion) equation, which governs the concentration of monomer during pyrolysis of a cylindrical ceramic moulding containing a polymer which degrades to monomer only, is solved: an infinite cylinder is considered. The method of lines is used to transform the partial differential equation into a system of first-order linear ordinary differential equations, the solution of which is seen to satisfy a recurrence relation. The concentration profile at a given time is computed by replacing the matrix exponential terms in this recurrence relation by a high-order Pade approximate. A parallel algorithm using two processors is developed by taking the partial fraction decomposition of the Pade approximate and a (matrix) rational expression in the recurrence relation

Incremental role of male circumcision on a generalised HIV epidemic through its protective effect against other sexually transmitted infections: from efficacy to effectiveness to population-level impact.

The protection of MC against STI contributes little to the overall effect of MC on HIV. Additional work is needed to determine whether, and under what conditions, the protective effect of MC efficacy against STIs can have a significant incremental benefit on the HIV epidemic

Numerical Methods for a Non-linear System Arising in Chemical Kinetics

Two numerical methods are proposed for the solution of a system of two dimensional reaction-diffusion equations with cubic non-linearity, known as the "Brusselator" system. The first method is derived using finite difference techniques and the solution is obtained in paralled using two processors running concurrently. The second method is based on a predictor-eorrector technique. This system of equations has important applications in chemical kinetics

Time-Series Satellite Imagery Demonstrates the Progressive Failure of a City Master Plan to Control Urbanization in Abuja, Nigeria

Urbanization is a global phenomenon, but its negative effects are most pronounced in developing countries. While much urbanization in the global South is unplanned, there have been occasional attempts at strategic, large-scale urban planning. One example is Abuja, Nigeria, a new city with origins in a 1970s Master Plan. Here, we use multi-temporal remote sensing to investigate four decades of urbanization in Abuja, showing the extent to which urban development has matched original intentions. Seven Landsat images from 1975 to 2014 were selected to correspond with Master Plan milestones and turning points in Nigeria’s socio-political development. Land cover classification and change detection results show built-up land increasing rapidly, from 1,167 ha in 1975 to 18,623 ha in 2014, mostly converted from grassland, often via a pioneer bare soil class. Comparing image analysis against the Master Plan shows that, in the early years, Abuja’s development matched broad planning intentions fairly closely. Later, though, unplanned development proliferated, and the city’s resemblance to the Master Plan diminished progressively. Level of adherence to the Master Plan varied widely according to the system of government. Notably, after long-term military rule was replaced by a democratic government around the turn of the millennium, unplanned development increased sharply

RISK-INDUCED BACKWARD BIFURCATION IN HSV-2 TRANSMISSION DYNAMICS

Abstract. A risk-structured, two-sex, model for the transmission dynamics of herpes simplex virus type 2 (HSV-2) in a population is designed and qualitatively analysed. It is shown that adding risk structure (i.e., the risk of transmitting or acquiring HSV-2 infection) to an HSV-2 transmission model causes the phenomenon of backward bifurcation when the associated reproduction threshold is less than unity. This dynamical feature, which has non-trivial consequence on the persistence or elimination of the disease (when the reproduction threshold is less than unity), can be removed if the susceptible male and female sub populations are not stratified according to the risk of acquiring HSV-2 infection

Cross-immunity-induced backward bifurcation for a model of transmission dynamics of two strains of influenza

A new deterministic model for the transmission dynamics of two strains of in- uenza is designed and used to qualitatively assess the role of cross-immunity on the transmission process. It is shown that incomplete cross-immunity could in- duce the phenomenon of backward bifurcation when the associated reproduction number is less than unity. The model undergoes competitive exclusion (where Strain i drives out Strain j to extinction whenever R0i > 1 > R0j ; i; j = 1; 2; i ̸= j). For the case where infection with one strain confers complete im- munity against infection with the other strain, it is shown that the disease-free equilibrium of the model is globally-asymptotically stable whenever the repro- duction number is less than unity. In the absence of cross-immunity, the model can have a continuum of co-existence endemic equilibria (which is shown to be globally-asymptotically stable for a special case). When infection with one strain confers incomplete immunity against the other. Numerical simulations of the model show that the two strains co-exist, with Strain i dominating (but not driving out Strain j), whenever R0i > R0j > 1.http://www.elsevier.com/locate/nonrwaam201

A primer on using mathematics to understand COVID-19 dynamics : modeling, analysis and simulations

The novel coronavirus (COVID-19) pandemic that emerged from Wuhan city in December 2019 overwhelmed health systems and paralyzed economies around the world. It became the most important public health challenge facing mankind since the 1918 Spanish flu pandemic. Various theoretical and empirical approaches have been designed and used to gain insight into the transmission dynamics and control of the pandemic. This study presents a primer for formulating, analysing and simulating mathematical models for understanding the dynamics of COVID-19. Specifically, we introduce simple compartmental, Kermack-McKendrick-type epidemic models with homogeneously- and heterogeneously-mixed populations, an endemic model for assessing the potential population-level impact of a hypothetical COVID-19 vaccine. We illustrate how some basic non-pharmaceutical interventions against COVID-19 can be incorporated into the epidemic model. A brief overview of other kinds of models that have been used to study the dynamics of COVID-19, such as agent-based, network and statistical models, is also presented. Possible extensions of the basic model, as well as open challenges associated with the formulation and theoretical analysis of models for COVID-19 dynamics, are suggested.The Simons Foundation and the National Science Foundation.http://www.keaipublishing.com/idmam2022Mathematics and Applied Mathematic

Sophorolipid biosurfactants: Possible uses as antibacterial and antibiofilm agent.

Biosurfactants are amphipathic, surface-active molecules of microbial origin which accumulate at interfaces reducing interfacial tension and leading to the formation of aggregated micellular structures in solution. Some biosurfactants have been reported to have antimicrobial properties, the ability to prevent adhesion and to disrupt biofilm formation. We investigated antimicrobial properties and biofilm disruption using sophorolipids at different concentrations. Growth of Gram negative Cupriavidus necator ATCC 17699 and Gram positive Bacillus subtilis BBK006 were inhibited by sophorolipids at concentrations of 5% v/v with a bactericidal effect. Sophorolipids (5% v/v) were also able to disrupt biofilms formed by single and mixed cultures of B. subtilis BBK006 and Staphylococcus aureus ATCC 9144 under static and flow conditions, as was observed by scanning electron microscopy. The results indicated that sophorolipids may be promising compounds for use in biomedical application as adjuvants to other antimicrobial against some pathogens through inhibition of growth and/or biofilm disruption