Bibliothek

Notizen: The components of genetic variation were studied in four F2 crosses (PG3× 5064, T163× B.V., T163× Arkel and 5064 × ED) for quantitative characters such as days to flowering, plant height, pod number, seed number, test weight and yield/plant. The overall epistasis (T type) was, in general, a major contributor for genetically controlling the expression of the characters in all the- four crosses except for the character seed number in crosses 1 and JV, where the j + l component at epistasis played a significant role in determining the expression of this attribute:. Though the ‘j + l’ component of the epistasis was significant, it was relatively less important than the ‘i’ type epistasis. Both the additive and dominance components of the genetic variation were highly significant for all the trans studied in all die four sets of crosses. The expression of the dominance was directional only for a few characters in certain crosses. The degree of dominance lies in the partial range, and heritability estimates obtained were high for most of the trails. The possible application of cross prediction in the isolation of superior recombinant inbred lines in pea is discussed.

Notizen: The effects of powdery mildew (Erysiphe pisi) disease of pea (Pisum sativum) on the number and size of root nodules and on nitrogenase activity were investigated in pea plants grown in pots and in the field. There were significant reductions in nodulation and in the size of root nodules as well as in nitrogenase activity in infected plants.

Notizen: Abstract— The crack closure stress intensity factor values and fatigue crack growth rates were determined in Three Point Single Edge Bend, SE(B), specimens prepared from rails manufactured using two different grades of rail steels. The width, and correspondingly the span, of the SE(B) specimens were varied eight fold; the thickness of all the specimens being the same. It is observed that the crack closure stress intensity factor values decrease with an increase in the width of SE(B) specimens. At a given value of ΔKeff, the fatigue crack growth rate (FCGR) is independent of the width. However, at a given value of ΔKeff, the FCGR is observed to decrease with increasing width. In view of the above results, the scope of application of the FCGR laws based on an effective stress intensity factor to the life prediction of components, requires careful examination.

Notizen: Zusammenfassung Elektronenoptische Beschreibung von «Cytosomen» in den Zellen vom Typus rot im PilzTaphrina maculans Butler.

Notizen: Summary White leaf disease of Bermuda grass (Cynodon dactylon Pers.) has been reported from a few countries to be caused by a mycoplasma-like organism. We have tried to observe the causal agent in white leaf diseased plants ofC. dactylon collected near Varanasi. Both tetracycline treatment and electron microscopy have revealed the presence of mycoplasma-like bodies in phloem cells of the diseased plants.

Notizen: Die design is heavily experience based and the die design process is an iterative procedure of trial and error in order to obtain a final die design for the successful manufacture of stampings. Most automotive industries use internal guidelines and past experience for die design. Even though powerful computer-aided design systems are being used in automotive industry, the lack of adequate analysis tools at the initial die geometry design stage hinders the die manufacturing process, and also necessitates lead times of the order of 5–30 weeks [1]. At the concept design stage, and during the initial die development process, the variations in geometry and process conditions are so large that it is prohibitively expensive to use 3D finite element analysis. The complexity of die design heuristic knowledge hinders the development and application of knowledge-based systems. Hybrid intelligent systems are computer programs in which at least one of the constituent models simulates intelligent behaviour [2]. These models could be knowledge-based systems, artificial neural networks, fuzzy logic systems, etc. In this approach both artificial neural networks, knowledge-based systems and finite-element analysis (FEA) for modelling the design process are used. A simulation-based design approach [3] for the die design process is followed. Artificial neural networks (ANNs) are preliminary design tools which indicate the formability of the component geometry, for the selected process and material conditions. The ANN module is trained from FEA results for a generic set of component geometries, process conditions, and material properties. The final die design validation is carried out by FEA. The intelligent frame-work incorporates rules for material selection, process parameter selection and their modification. Component geometry is a critical parameter which affects the manufacturability of the given part. Hence, an intelligent geometry handling module, which automatically modifies and optimises the geometry of the designed die, is implemented in the present system. Knowledge-based blackboard architecture is used for the integration of various analysis models such as CAD, FEA, and ANN, as an intelligent framework for die design [4]. The hybrid intelligent system provides an integrated decision support environment for simulation and analysis of the forming process, both during the initial die design phase and during the die tryout phase. The hybrid intelligent systems approach supports the capability for automatic evaluation of prospective die design for manufacturability, and performs automatic modification of design inputs. Applications of the hybrid intelligent system for die design are described together with a comparison with shop floor data.

Notizen: Abstract Discrete chorus-type emission and whistler precursors recorded in March 1972 during day time hours at our ground based station Gulmarg are presented. It is shown that discrete chorus type emissions are generated in the equatorial region (L ∼ 1.2) during cyclotron resonance interaction between the propagating whistler wave and the gyrating electrons. The whistler precursors are explained in terms of the mechanism suggested by Dowden (1972).