Studies on length-weight relationship of Gerres filamentosus Cuvier from the estuaries of the southern Karnataka coast

Random samples of Gerres filamentosus Cuvier from the Netravathi-Gurpur, Mulky, Kallayanapura, Mabukala and Kundapura estuaries of the southern Karnataka Coast were collected in the years 2000, 2001 and 2002, and length-weight relationships for each estuary were derived using multiple linear regression technique with one dummy variable. Hence, combined or sex-wise length-weight relationships were obtained after testing for homogeneity and isometric growth condition of fishes for each estuary by t-test. The extent of closeness of length-weight relationships between sexes and among estuaries for different years is explained by a trend line graph. The whole process of multiple linear regression analysis with one dummy variable is a better substitute for the analysis of covariance technique

Primary double tooth with partial anodontia of permanent dentition: a case report

Dental anomalies of number and forms may occur in the primary and permanent dentition. Various terms have been used to describe dental twinning anomalies: gemination, fusion, concrescence, double teeth, cojoined teeth, twinned teeth, geminifusion and vicinifusion. Double tooth is a term used to describe connate tooth and includes both dental fusion and gemination. The phenomenon of gemination occurs when two teeth develop from one single bud leading to a larger tooth. Fusion is a condition in which the crowns of two separate teeth have been joined toge- ther during the crown development. Fusion occurs infrequently but could cause esthetic, spacing and periodontal problems. The present article highlights the presence of a primary double tooth in an 11 year old boy involving primary mandibular left lateral incisor and canine. Clinical examination and radiographic examination confirmed the absence of the permanent left mandibular lateral incisor. Cases with primary double tooth necessitate careful examination as they may be associated with anomalies in the succeeding permanent dentition and require proper treatment plannin

Fatigue response evaluation of stainless steel SS 304 L(N) and SS 316 L(N) through cyclic ball indentation studies

This paper presents the results of an experimental investigation of fatigue response of stainless steel SS 304 L(N) and SS 316 L(N) using cyclic ball indentation test method. A Tungsten Carbide (WC) spherical ball of 1.57 mm diameter is used for applying compression-compression fatigue cycling on the test specimen having a nominal thickness of 5 mm; the displacement response is monitored as a function of every cycle of loading. The study focused on cases where the stainless steel specimens were welded by two different welding processes – Activated flux TIG welding and conventional multi-pass TIG welding. Fatigue response was monitored at locations of weld zone, heat affected zone (HAZ) and base metal to identify the effect of microstructure variation on fatigue response. It is observed that there is a steady increase in depth of penetration of the spherical indenter due to fatigue cycling; however, after a number of cycles, there is a sudden increase in depth of penetration which indicates the failure of the material beneath the indenter. The specimens after cyclic ball indentation were examined using a scanning electron microscope and one could observe the presence of secondary cracking in the penetrated region of the specimen

Virus shapes and buckling transitions in spherical shells

We show that the icosahedral packings of protein capsomeres proposed by Caspar and Klug for spherical viruses become unstable to faceting for sufficiently large virus size, in analogy with the buckling instability of disclinations in two-dimensional crystals. Our model, based on the nonlinear physics of thin elastic shells, produces excellent one parameter fits in real space to the full three-dimensional shape of large spherical viruses. The faceted shape depends only on the dimensionless Foppl-von Karman number \gamma=YR^2/\kappa, where Y is the two-dimensional Young's modulus of the protein shell, \kappa is its bending rigidity and R is the mean virus radius. The shape can be parameterized more quantitatively in terms of a spherical harmonic expansion. We also investigate elastic shell theory for extremely large \gamma, 10^3 < \gamma < 10^8, and find results applicable to icosahedral shapes of large vesicles studied with freeze fracture and electron microscopy.Comment: 11 pages, 12 figure

Population Dynamics and Non-Hermitian Localization

We review localization with non-Hermitian time evolution as applied to simple models of population biology with spatially varying growth profiles and convection. Convection leads to a constant imaginary vector potential in the Schroedinger-like operator which appears in linearized growth models. We illustrate the basic ideas by reviewing how convection affects the evolution of a population influenced by a simple square well growth profile. Results from discrete lattice growth models in both one and two dimensions are presented. A set of similarity transformations which lead to exact results for the spectrum and winding numbers of eigenfunctions for random growth rates in one dimension is described in detail. We discuss the influence of boundary conditions, and argue that periodic boundary conditions lead to results which are in fact typical of a broad class of growth problems with convection.Comment: 19 pages, 11 figure

Reuse of Treated Wastewater: Drivers, Regulations, Technologies, Case Studies, and Greater Chicago Area Experiences

Water reuse is a practical solution to augment water supplies in areas where water resources are increasingly scarce. Water reuse technology is versatile and can be used to alleviate the different causes of water scarcity, such as groundwater depletion or increased availability of brackish water. Treatment technologies can be tailored specifically to the end use of recycled water, focusing on these drivers that are region-specific, for a more cost-effective treatment system. This is called a “Fit-for-Purpose” strategy that is commonly implemented in any water reuse project. However, implementing water reuse can be challenging due to infrastructural requirements, economic issues, and social acceptance. To help navigate these challenges, this article provides a comprehensive review of water reuse cases and presents guidelines that can act as a reference framework for future water reuse projects. This article also makes the case for implementing water reuse in the Greater Chicago area as a means of alleviating pressure on withdrawals from Lake Michigan