A theoretical work has been made on the nonlinear propagation of dust ion acoustic (DIA) solitary waves (SWs) and double Layers (DL’s) in a multi-ion dusty plasma system (MIDP), consisting of inertial positive and negative ions, Maxwell’s electrons, and arbitrary charged stationary dust. The dust particles have been considered as arbitrarily (either positively or negatively) charged in order to observe the effects of dust polarity on the DIA SWs and DL’s. The basic properties and dynamics of planar solitary waves (SWs) and double layers (DLs) have been observed. Through this work the changing of basic properties of these waves with thermal states have also been observed. First, a detail mathematical derivation and numerical analysis on the linear properties as well as the dispersion relation in the dusty multi-ion system at isothermal system has done. Then in order to observe the nonlinear properties through the entire regime, three different approaches (K-dV (Korteweg-de Vries), mK-dV (mixed K-dV), and Gardner) have been employed for both the isothermal and adiabatic systems. The reductive perturbation method has been employed in all these three approaches. Using reductive perturbation method, we ﬁrst derive K-dV equation which let to analyze both bright and dark solitons in a very limited region. After that mK-dV equation has been derived which let analyze bright soliton for a large region, but cannot show the dark soliton and DL’s. Finally, Gardner equation has been derived employing the same method, through which we were able to analyze both the bright and dark solitons for a large region. .
A composite material is one in which two or more materials that are different are combined to form a single structure with identifiable interfaces at multi-scales to achieve properties that are superior to those of its constituents. Composites are designed to achieve unique mechanical properties and superior performance characteristics not possible with any of the component material alone. An experimental work was done at Textile Physics Division of BJRI in 2015 for the manufacture of jute, cotton and glass fire reinforced composite corrugated sheet suitable for roofing in poultry and rural housing. .For the investigation jute, cotton and glass fibre were used as reinforcing material and polyester resin were used as matrix material. This paper reports the findings of an experimental investigation conducted on the engineering properties of jute, cotton and glass fibre reinforced composite corrugated sheet. Different fabric design and volume fractions were used as reinforcement for corrugated sheet to determine the physical, mechanical and thermal properties of the composite. The results of this investigation have shown the feasibility of using jute fibres for producing low cost housing materials..
We have deﬁned slowness (or reciprocal velocity) corresponding to velocity (v) as cc/v, where c is the speed of light and v is the corresponding velocity. Velocity and slowness are images of each other. Reciprocal symmetric law of addition of velocities fulﬁls the requirement that the sum (or the difference) of velocities remains unchanged if velocities are replaced by the corresponding slownesses. We have postulated reciprocal symmetry, which states that every valid statement has an equally valid (reciprocal) image statement. The postulate has allowed us to derive.