Comparative study on indoor fungi growth incorporated with different antifungal and wall finishings

Indoor air quality is important to the health and comfort of building occupants. There are many sources of pollutants that can be found in the building. One of the sources of pollutants is fungus. Fungi are present almost everywhere in indoor and outdoor environments. Building materials supporting fungal growth must be remediated as rapidly as possible in order to ensure a healthy environment. The goal of this study is to compare the growth of indoor fungal by using three different antifungals such as potassium sorbate, zinc salicylate and calcium benzoate. The indoor fungi were isolated from selected room at Faculty of Civil and Environmental Engineering (FKAAS). The objective is to enumerate the growth of indoor fungal after incorporate with antifungal at different types of wall finishes and evaluate its efficiency. This research was done on three main substrates which are wood, plasterboard and concrete. These main materials were each coated with four types of coating which are thin wallpaper, thick wallpaper, glycerol based paint and acrylic paint. The growth rate was monitored as all the materials was applied with the antifungal. The antifungal has reduced the growth rate of the fungus but depending on the type of material and coating that is used. Results shows that for wood substrate, the best antifungal treatment is a mix of thick wallpaper and calcium benzoate, where the growth stops at 53% (CB 53% < PS 87% < ZS 90% < CTRL 93%). As for plasterboard substrate, thin wallpaper and potassium sorbate hinders the growth at 40% (PS 40% < ZS 73% < CB 80% < CTRL 97%) whereas for concrete substrate, acrylic paint and glycerol based paint incorporated with calcium benzoate renders the growth of fungi to stop at 0% throughout the test (Acrylic Paint = CB 0% < ZS 7% < PS 7% < CTRL 33%) and (Glycerol Based Paint = CB 0% < PS 70% < ZS 73% < CTRL 87%). Thus, the best building material would be concrete with the application of calcium benzoate for paint type of wall finishing’s

Progress in Surface Theory

Over the last 30 years global surface theory has become pivotal in the understanding of low dimensional global phenomena. At the same time surface geometry became a platform on which seemingly different areas of mathematics – such as geometric and topological analysis, integrable systems, algebraic geometry of curves, and mathematical physics – coalesce to produce far reaching ideas, conjectures, methods and results. The workshop hosted talks on the resolutions of famous conjectures in surface geometry, including the Willmore conjecture, and on exciting new progress in the understanding of moduli spaces of special surface classes

Geometric rigidity of constant heat flow

Let $\Omega$ be a compact Riemannian manifold with smooth boundary and let $u_t$ be the solution of the heat equation on $\Omega$, having constant unit initial data $u_0=1$ and Dirichlet boundary conditions ($u_t=0$ on the boundary, at all times). If at every time $t$ the normal derivative of $u_t$ is a constant function on the boundary, we say that $\Omega$ has the {\it constant flow property}. This gives rise to an overdetermined parabolic problem, and our aim is to classify the manifolds having this property. In fact, if the metric is analytic, we prove that $\Omega$ has the constant flow property if and only if it is an {\it isoparametric tube}, that is, it is a solid tube of constant radius around a closed, smooth, minimal submanifold, with the additional property that all equidistants to the boundary (parallel hypersurfaces) are smooth and have constant mean curvature. Hence, the constant flow property can be viewed as an analytic counterpart to the isoparametric property. Finally, we relate the constant flow property with other overdetermined problems, in particular, the well-known Serrin problem on the mean-exit time function, and discuss a counterexample involving minimal free boundary immersions into Euclidean balls.Comment: Replaces the earlier version arXiv: 1709.03447. To appear in Calculus of Variations and PD

Progress in Surface Theory

The theory of surfaces is interpreted these days as a prototype of submanifold geometry and is characterized by the substantial application of PDE methods and methods from the theory of integrable systems, in addition to the more classical techniques from real and/or complex analysis. In addition, surfaces with singularities are studied intensively. In this workshop we brought together all the main strands of modern surface theory

Non‐linear analysis of an integral bridge

This study describes the implementation of a 2‐D finite element model of an integral abutment bridge (IAB) system which explicitly incorporates the nonlinear soil response. The superstructure members have been represented by means of three‐node isoparametric beam elements with three degrees of freedom per node. The soil mass is idealized by eight node isoperimetric quadrilateral element at near field and five node isoparametric infinite element to simulate the far field behavior of the soil media. The non‐linearity of the soil mass has been represented by using the Duncan and Chang hyperbolic model. The applicability of this model was demonstrated by analyzing a single span IAB. This study has shown that the soil nonlinearity has significant effect on the response of the structure, where the displacement that have been obtained on basis of nonlinear analysis is 1.5–2.0 times higher than that obtained from linear analysis. The stress magnitudes in the nonlinear analysis are also higher where in some point the difference reached almost 3 times. Santrauka Straipsnyje aprašoma, kaip taikomas 2‐D baigtiniu elementu metodas tilto sistemai su integraliniais ramtais analizuoti, apimant ir netiesine grunto elgsena. Antžemines tilto dalies laikantieji elementai modeliuojami taikant triju mazgu izoparametrinius strypinius elementus su trimis laisves laipsniais kiekviename mazge. Grunto masyvui modeliuoti taikomi aštuoniu mazgu izoparametriniai ketursieniai elementai arti tilto esančioje aplinkoje ir penkiu mazgu izoparametriniai begaliniai elementai, imituojantys grunto terpes elgsena nuo tilto nutolusiose srityse. Grunto masyvo elgsenos netiesiškumas ivertinamas Duncan ir Chang hiperboliniu modeliu. Jo tinkamumas aiškinamas analizuojant vieno tarpatramio integralini tilta. Atlikti tyrimai parode, kad grunto savybiu netiesiškumas turi didele itaka tilto konstrukciju elgsenai. Tilto poslinkiai, nustatyti taikant netiesine analize, yra 1,5–2,0 karto didesni už poslinkius, nustatytus taikant tiesine analize. Atlikus netiesine analize nustatyti itempiai taip pat yra didesni, o kai kuriais atvejais skirtumas siekia beveik tris kartus. Reikšminiai žodžiai: tiltas su integraliniais ramtais, grunto ir konstrukcijos saveika, netiesine analize, baigtiniu elementu analiz