V. K. Jain , S. N. Sanyal

Abstract

Microwaves are electromegnatic waves. The speed and attenuation of which depend on the medium in which they are propapted.This paper report on the attenuation of these by few indian Wood-species. The result have shown that the attenuation constant is linearly related to the specitic gravity of wood for specific gravity below 0.5 and is practically independent for specitic gravity range above 0.5. This trend offer a non-destructive method for detecting defecte like decayed portion of knot etc. inside the wood.

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N. K. Shukla , P. C. Verma , Krishan Lal , Mohan Lal , S. N. Sanyal

Abstract

Based on the tests conducted on small clear specimens of plantation grown Acacia leucophloea. A. nilolica and A. tortilis from Mohindergarh (Haryona), their physical and mechanical properties have been reported and discussed. Although all the three species are heavier than Teak, they are not superior to Teak in several mechanical properties. Based on suitability indices, these species have been grouped as very heavy and moderately steady timbers. From strength point of view, all the three species are suitable for constructional purposes, railway sleepers, tool bandies, fence posts, agricultural implements, anvil blocks, mallet heads etc. A. nilotica and A. tortilis are also suitable for the manufaCture of dunnage pallets.

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S. N. Sanyal , A. S. Gulati , A. K. Khanduri

Abstract

The basic strength properties evaluated in a systematic way by different workers from time to time are scattered in the form of individual papers and some of the important publications are not readily available. The object of this paper is to compile all the data so far available on physical and mechanical properties of bamboos in different publications in a consolidated form so that it is available for ready reference. An attempt has also been made to analyse the data so collected from different parameters.

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S. N. Sanyal , N. S. Rawat

Abstract

The physical and mechanical properties of Manglietia sp. Received from Margherita Range, Digboi Division, Assam and tested in Green and air-dry condition have been reported and the results have been compared with Manglietia
insignis and standard teak. Based on the strength figure obtained, its suitability indices for Industrial and Engineering uses and Safe working stresses have also been reported and possible end uses suggested.

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S. N. Sanyal , R. C. Millen

Abstract

In wood the influence of hygroscopic moisture is very important. Small elastic deformation imposed for a period of time may turn into plastic deformation. Hooke's Law is not very much applicable in a wide range for a complicated material like wood. Stress strain behaviour is therefore differen in wood as compared to other elastic bodies. In this paper the authors have studied, at room temperature and different R.H. the stress strain hysteresis phenomenon of Chir species. The hysteresis area reflects the work done for cycle which is lost as heat and other form of energy and is a measure of the non reversable process of stress strain in the case of wood.

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S. N. Sanyal , C. N. Pandey

Abstract

The purpose of the study described in this report was to investigate the nondestructive testing of maximum crushing strength of wood based on the relationship between its vibrational parameters and mechanical proderties. A close corvilinear relationship between maximum crushing strength and quantity ρ/V A was observed.

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S. N. Sanyal , A. S. Gulati

Abstract

Ultrasonic pulse techniques in the field of non-destructive testing of muterials are well known. In the present work an attempt has been made to determine the relationship between compressive strength and ultrasomic velocity along the grain in timber. Ultrasonic velocity in several Indian timber species were measured with the help of Ultrasonic tester and the specimens were then subjected to determine the compressive strength parallel to the grain with conventional test methods. From the data so obtained, a relationship has been established, which can be very well utilised in determining compressive strength of different timber members or the stractures io 'Situ'

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S. N. Sanyal , C. N. Pandey

Abstract

In this Paper an endeavour has been made to establish simple relationship between ultrasound attenuation and specific gravity at a particular moisture content (as for as practicable) for various timber speeimens. As such from this relation by measuring the ultrasound attenuation quality of the material can be easily estimated in situ.

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