Physics of shock waves and high-temperature hydrodynamic phenomena - Ya.B. Zeldovich and Yu.P. Raizer (translated from the Russian and then edited by Wallace D. Hayes and Ronald F. Probstein); Dover Publications, New York, 2002, 944 pp., $34.

By L I Sedov London: Cleaver-Hume Press Ltd Pp xvi + 363 Price 105s This is really two separate books within the same pair of covers First of all Chapters 1-3, some 145 pages, are devoted to the discussion of similarity and dimensional, methods and their application to a variety of problems in mechanics and fluid mechanics

http://iopscience.iop.org/article/10.1088/0031-9112/11/6/008/pdf

Similarity and Dimensional Methods in Mechanics

Preface. 1. Plasmas and Dust. 2. Charging Mechanisms and Experiments. 3. Space Observations. 4. Multispecies Formalism and Waves. 5. Electrostatic Modes. 6. Electromagnetic Modes. 7. Fluctuating Dust Charges. 8. Self-Gravitation. 9. Mass and Size Distributions. 10. Other Modes. 11. Conclusions and Outlook. Bibliography. Index.

https://physicstoday.scitation.org/doi/pdf/10.1063/1.1404853

Waves in Dusty Space Plasmas

Vermicomposting is a process in which earthworms are used to convert organic materials into humus-like material known as vermicompost. A number of researchers throughout the world have found that the nutrient profile in vermicompost is generally higher than traditional compost. In fact, vermicompost can enhance soil fertility physically, chemically and biologically. Physically, vermicompost-treated soil has better aeration, porosity, bulk density and water retention. Chemical properties such as pH, electrical conductivity and organic matter content are also improved for better crop yield. Nevertheless, enhanced plant growth could not be satisfactorily explained by improvements in the nutrient content of the soil, which means that other plant growth-influencing materials are available in vermicomposts. Although vermicomposts have been shown to improve plant growth significantly, the application of vermicomposts at high concentrations could impede growth due to the high concentrations of soluble salts available in vermicomposts. Therefore, vermicomposts should be applied at moderate concentrations in order to obtain maximum plant yield. This review paper discusses in detail the effects of vermicompost on soil fertility physically, chemically and biologically. Future prospects and economy on the use of organic fertilizers in the agricultural sector are also examined.

The use of vermicompost in organic farming: overview, effects on soil and economics

In the present review, vermicompost is described as an excellent soil amendment and a biocontrol agent which make it the best organic fertilizer and more eco-friendly as compared to chemical fertilizers. Vermicompost is an ideal organic manure for better growth and yield of many plants. It can increase the production of crops and prevent them from harmful pests without polluting the environment. Application of vermicompost increased seed germination, stem height, number of leaves, leaf area, leaf dry weight, root length, root number, total yield, number of fruits/plant, chlorophyll content, pH of juice, TSS of juice, micro and macro nutrients, carbohydrate (%) and protein (%) content and improved the quality of the fruits and seeds. Studies suggested that treatments of humic acids, plant growth promoting bacteria and vermicomposts can be used for a sustainable agriculture discouraging the use of chemical fertilizers.

Vermicompost as an effective organic fertilizer and biocontrol agent: effect on growth, yield and quality of plants

Similarity solutions are obtained for unsteady, one-dimensional self-similar flow behind a strong shock wave, driven by a moving piston, in a dusty gas. The dusty gas is assumed to consist of a mixture of small solid particles and a non-ideal gas, in which solid particles are continuously distributed. It is assumed that the equilibrium flow-condition is maintained and variable energy input is continuously supplied by the piston. Solutions are obtained under both the isothermal and adiabatic conditions of the flow-field. The spherical case is worked out in detail to investigate to what extent the flow-field behind the shock is influenced by the non-idealness of the gas in the mixture as well as by the mass concentration of the solid particles, by the ratio of density of the solid particles to the initial density of the mixture and by the energy input due to moving piston. A comparison is also made between isothermal and adiabatic cases.

A self- similar solution of a shock propagation in a mixture of a non-ideal gas and small solid particles

Similarity solutions for the flow of a non-ideal gas behind a strong exponential shock driven out by a piston (cylindrical or spherical) moving with time according to an exponential law are obtained. Similarity solutions exist only when the surrounding medium is of constant density. Solutions are obtained, in both the cases, when the flow between the shock and the piston is isothermal or adiabatic. It is found that the assumption of zero temperature gradient brings a profound change in the density distribution as compare to that of the adiabatic case. Effects of the non-idealness of the gas on the flow-field between the shock and the piston are investigated. The variations of density-ratio across the shock and the location of the piston with the parameter of non-idealness of the gas $${\overline{b}}$$
 are also obtained.

Similarity solutions for the flow behind an exponential shock in a non-ideal gas

Magnetogasdynamic shock wave generated by a moving piston in a rotational axisymmetric isothermal flow of perfect gas with variable density

2 Abstract: In India million tons of livestock excreta, agro and kitchen wastes are produced every year which are serious problems for society. This work to evaluate the potential of an epigeic earthworm Eisenia foetida to convert the different combination of variety of wastes in to rich nutrient vermicomposts/vermiwash and pre and post chemical analysis of feed mixtures. Vermicomposting results in significant decreased in pH, Total organic carbon (TOC), electrical conductivity (EC) and C:N ratio while significant increase in total Kjeldohl nitrogen (TKN) available phosphorus, exchangeable potassium and calcium in vermicomposts/vermiwash. The increased level of plant nutrients in final products in different organic resources demonstrated that the vermicompost/vermiwash of these wastes will be a valuable biofertilizer for sustainable land restoration practices. This study clearly indicates that vermicomposting of animal, agro/kitchen wastes not only produced a valuable vermicompost/vermiwash but also increased level of plant growth supplements in final vermicompost.

Chemical analysis of vermicomposts/vermiwash of different combinations of animal, agro and kitchen wastes.

One-dimensional self-similar unsteady flow behind a strong exponential shock driven out by a piston moving with time according to an exponential law is investigated. The medium is assumed to be a mixture of small solid particles and a perfect gas. In order to get some essential features of the shock propagation, small solid particles are considered as pseudo-fluid and it is assumed that the equilibrium flow condition is maintained in the flow-field, and that the viscous-stress and heat conduction of the mixture are negligible. Solutions are obtained, in both cases, when the flow between the shock and the piston is isothermal or adiabatic. It is found that the assumption of zero temperature gradient brings a profound change in the density distribution as compared to that of the adiabatic case. Effects of a change in the mass concentration of the solid particles in the mixture Kp and the ratio of the density of solid particles to that of initial density of the gas G1 are also obtained.

https://iopscience.iop.org/article/10.1088/0031-8949/74/4/015/pdf

G. Nath

Papers

A self- similar solution of a shock propagation in a mixture of a non-ideal gas and small solid particles

Similarity solutions for the flow behind an exponential shock in a non-ideal gas

Magnetogasdynamic shock wave generated by a moving piston in a rotational axisymmetric isothermal flow of perfect gas with variable density

Chemical analysis of vermicomposts/vermiwash of different combinations of animal, agro and kitchen wastes.

Similarity solutions for unsteady flow behind an exponential shock in a dusty gas