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Anand V. Kulkarni and Venkatesh K. Havanur Laxmi Publications PDF
Medium 9789381159101


Anand V. Kulkarni and Venkatesh K. Havanur Laxmi Publications PDF

Chapt er







Two dimensional problems in structural analysis are dealt in this chapter. Hand calculations, even with two elements, become too long and hence are not given for these problems; only analytical method solutions and software solutions have been provided.

Two dimensional problems can either be plane stress or plain strain problems. Method of analysis is same for both, except that stress strain matrix is different in two cases.

Plane bodies that are flat and of constant thickness subjected to in-plane loading fall under the category of plane stress problems. Stress components z, xz and yz assume zero values in these problems.

Some of the elements used in the analysis of two dimensional problems are constant strain triangle(CST), linear strain triangle(LST), linear quadrilateral, isoparametric quadrilateral, etc. each of these elements has two degrees of freedom per node namely translation in x and y directions.

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20: Biological Control

van Emden, H.F. CABI PDF


Biological Control1

Thierry Hance,1* Fatemeh Kohandani-Tafresh1 and Françoise Munaut2


Biodiversity, Earth and Life Institute, Université catholique de Louvain,

Louvain-la-Neuve, Belgium; 2Applied Microbiology, Earth and Life Institute,

Université catholique de Louvain, Louvain-la-Neuve, Belgium


In recent decades, the development of new concepts in ecology, such as ecosystem services (Losey and

Vaughan, 2006), landscape ecology, food web complexity (Gagic et  al., 2011), apparent competition and mutualism, has changed our concepts of pest control. Consequently, the theoretical bases underlying the biological control of aphids have evolved towards a more integrated approach. The intensification of agriculture has led to an oversimplification of agricultural systems, and therefore also of the associated trophic systems. The extreme case is that of glasshouses, in which crops are increasingly grown hydroponically, without soil and fed with nutrient solutions. These simplified environments are particularly poor in natural enemies and are susceptible to pests.

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Dr. Priyanka Siwach ; Dr. Namita Singh Laxmi Publications PDF






Sanger’s Di-deoxy Sequencing Method

Dry-lab Demonstration of Di-deoxy Method

Maxam and Gilbert Sequencing Method

Dry-lab Demonstration of Maxam-Gilbert’s Method

Automated DNA Sequencing


DNA Sequencing is the technique by which correct and precise order of nucleotides in a piece of DNA can be determined. Acquiring knowledge of nucleic acid sequences is at the heart of molecular biology. DNA sequencing today is chiefly used to characterize newly cloned DNA, to confirm the identity of a clone or mutation, to check the fidelity of a newly created mutation, ligation, junction or product of a polymerase chain reaction (PCR) and in some cases as a screening tool to identify polymorphisms and mutations in genes of particular interest.

The history of sequencing goes back to 1964 when attempt was made by Robert Holly and group to sequence tRNA and they were quite successful in doing so for 77 nucleotide long yeast alanine tRNA. Several attempts were made to apply this method to DNA but with limited success. Within 10 years, as a consequence of repeated and focused efforts, one American group led by Maxam and Gilbert at Harvard University and one English group led by Sanger at Cambridge, independently developed two methods for the large scale sequencing of DNA.

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Dr. R.K. Bansal Laxmi Publications PDF






Compressible flow is defined as that flow in which the density of the fluid does not remain constant during flow. This means that the density changes from point to point in compressible flow. But in case of incompressible flow, the density of the fluid is assumed to be constant. In the previous chapters, the fluid was assumed incompressible, and the basic equations such as equation of continuity, Bernoulli’s equation and impulse momentum equations were derived on the assumption that fluid is incompressible. This assumption is true for flow of liquids, which are incompressible fluids. But in case of flow of fluids, such as

(i) flow of gases through orifices and nozzles,

(ii) flow of gases in machines such as compressors, and

(iii) projectiles and airplanes flying at high altitude with high velocities, the density of the fluid changes during the flow. The change in density of a fluid is accompanied by the changes in pressure and temperature and hence the thermodynamic behaviour of the fluids will have to be taken into account.

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