The possibility of attenuation of microseismic waves due to the presence of an upward folding of the ocean bottom into the liquid is discussed in this paper. The upward folding of the ocean bottom has been idealized by means of an irregularity in the form of a rectangle intruding into the liquid and the evaluation of the displacement component at any point of the solid medium has been carried out in two stages. First, the change in the incident mode of the surface wave due to the presence of the rectangular irregularity has been determined, and second, the subsequent change of the resulting displacement components due to the termination of the liquid layer and the step change in elevation of the solid medium at the continental margin has been discovered. Finally, numerical calculation has been made to determine the attenuation of the microseismic waves of different periods due to the presence of the rectangular irregularity at the ocean bottom.

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We observed transients during the isotopic analysis of carbon dioxide, which could not be attributed to mixing processes because of their asymmetry, and to explain these we were led to consider the effects of diffusion on gas flow in the sample line. In particular, we investigated the propagation by diffusion of a concentration anomaly against a steady gas flow. If fractionation of isotopic(or chemical)species at the leak is to cause a change with time of the composition of the gas in the sample reservoir, then the effects of the fractionation must diffuse backwards as far as the gas reservoir.Using a one-dimensional Green's function, we obtained explicit analytical functions for the steady state concentration variation along a connecting tube between the leak and the reservoir, and for the composition variations with time at the leak. It is shown that the isotopic composition in the sample reservoir need not vary with time, even with a fractionating leak, provided that bulk gas velocity in the connecting tube is large enough. It is also shown that the diffusion process in combination with a fractionating leak can lead to the type of transients we observed.

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The ability of Climacodon septentrionalis to immobilize and kill a mycophagous nematode (Aphelenchoides sp.) in vitro is described for the first time. Two isolates produced droplets (20–45 μm in diameter) that formed at the apices of tall, stalked, and branching secretory cells (700–1,500 μm tall). On 2% modified malt extract agar, nematodes became enveloped in the droplets, which restricted their ability to move and resulted in complete immobilization and death within several hours of contact. The rate of decomposition of the nematodes varied considerably, with most individuals persisting for weeks whereas others were degraded within several days and appeared to be colonized by dense hyphal growth. This study provides the first documentation of a non-agaricoid fungus producing secretory cells that are able to immobilize nematodes.

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The effect of composition and controlled thermomechanical process parameters on the mechanical properties of HSLA steels is modelled using the Widrow-Hoff's concept of training a neural net with feed-forward topology by applying Rumelhart's back propagation type algorithm for supervised learning, using a Petri like net structure. The data used are from laboratory experiments as well as from the published literature. The results from the neural network are found to be consistent and in good agreement with the experimented results.

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Horizontal plate anchors are widely used in civil engineering constructions to resist vertical pulling loads. The available theoretical model suggested by Vesic to estimate the breakout resistance of plate anchors is in significant error, particularly for dense sandy soils. A theoretical model assuming a curved surface of failure through the surrounding soil, to evaluate the ultimate breakout resistance of horizontal plate anchors, has been proposed. It successfully brings out the concept of characteristics relative depth beyond which the breakout factor reaches a constant final value. It is capable of predicting breakout factors for wide range of values of angle of shearing resistance of sand.

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An unsupervised learning technique and an associative memory have been used for encoding weights by a special type of Petri network named Petri neural net for modelling the influence of alloying elements on the final property of the high strength low alloy steel. The combined effects of alloying elements for different strengthening mechanisms is predicted when weights and threshold values are chosen on the basis of metallurgical understanding. The technique is found to be effective to create an associative memory of input-output relations in unknown data sets so that the same can be subsequently be used as a predictive tool.

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Primarily from the point of view of improvement of yield strength due to additions of niobium, titanium and boron in HSLA steels, the experimental steels are divided into five classes. The data are then supplied for learning a Self Organising Map (Kohonen network). It is found that the network with six neurons possesses better capacity of prediction with unknown data. Another effort of clustering the steels according to its major strength contributing mechanisms is also made. But the capacity of the network to cluster unknown data is found to be rather poor and has failed to follow from the metallurgical principles. To avoid this limitation, Learning Vector Quantisation method is adopted to impart a certain amount of supervision in the learning process and it is found that the training pattern of the network attains a good convergence thereby leading to a good predictive ability.

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A boron treated copper bearing HSLA steel containing austenite formers like manganese and nickel, somewhat lower in amount than that in HSLA 100 variety of steel is chosen for the study. The role of thermomechanical processing on the microstructure and mechanical properties of the above steel has been investigated. Differential scanning calorimetric study is carried out for understanding the precipitation behaviour of copper in HSLA steel under the influence of boron. The microstructure of the experimental steel is found to consist of laths of martensites and bainite. MA constituents of ribbon like morphology are observed at the lath boundaries. Higher strength properties of the steel are attributed to the presence of finely distributed precipitates of copper and microalloy carbides.

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Zebra mussels have profound environmental impact on any area they infest. They also foul all exposed marine structures and cause a number of problems to industrial raw water users. The reason for this is rooted in their biology. One of the primary biological factors of concern is the presence of a vast number of free living larvae (the veligers) . The free living larvae aid dispersal and allow penetration and infestation of industrial systems. All raw water systems are vulnerable to infestation to greater or lesser degree. Of particular concern are safety systems such as fire protection.
The ability of the mussel to firmly attach to a wide range of substrates results in fouling of all available surface and difficulty in removal.
Further, the hard shell of the adult allows it to isolate itself from the environment and survive short periods of unfavourable conditions.
Monitoring for their arrival and their seasonal abundance provides early warning and triggers mitigation.
This paper deals briefly with the biology of zebra mussels, how to monitor for them and how to decide on proactive vs reactive treatment strategy for industrial systems. To-date, many different chemical and non-chemical techniques for zebra mussel control have been investigated. However, the treatment of choice for most facilities is still based on some form of chemical control.

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First we introduce the upper triangular lattice form method that permits one to derive easily the complete set of finite lattices of any given number, N, of vertices for any regular infinite lattice in any number of dimensions, and we use it to obtain all finite fcc lattices of N<28. We compute the ground state energy, magnetization and spin-spin correlations of the spin one-half XY ferromagnet on each of these lattices. Extrapolation of these data to infinite N yields T=0 estimates of the properties mentioned. Our estimates agree to a few tenths of a percent with spin wave, series expansion and variational estimates.

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Simultaneous measurements of the total geomagnetic field intensity by the same type of the proton precession magnetometers at two stations in NW Turkey have been taken cooperatively by a research group since December 1970. Up to the end of July 1971 mainly three probable local magnetic changes were observed. It was seen that after a decrease in the local field at a magnetic station (Erdek) a few earthquakes occured at either nearly N or S of that station, and after an increase in the local field an earthquake took place nearly W of the same station. In this paper the data and some results of the first part of observations are given.

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Nine isoquinoline alkaloids belonging to the protoberberine, proaporphine and bisbenzyl-isoquinoline series were isolated from Caryomene olivascens (Menispermaceae). Four compounds are new : (-)-2-norlimacine (), (-)-caryolivine (), (+)-1, 2-dehydro-2-norlimacusine (9) and N-formylstepharine (). The last one is the first N-formyl derivative to be reported in the proaporphine group. Its biogenetic origin is discussed. Structures were established on the basis of 360 MHz (FT) nuclear magnetic resonance measurements and also by chemical correlation in the case of .

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