Problem of bracken (Pteris aquilina) in relation to animal health

The problem of bracken in relation to animal health is ill understood not only in this part of the world but also on the Continent, in the United States of America and in Australia. Time and again, attempts to solve the mystery were baffled in the face of inadequate data. It is also possible that the harmful effects of bracken or plants of the same species and genus, have escaped detection in many other parts of the world, when the cause of death in many cattle remained obscure. The importance of the problem will perhaps be sufficiently apparent from the vast acreage (more than 3 - 4 millions of hill-grazings in Scotland) being infested by bracken which is invading on fresh fronts, all over the country, every day. For many years past, beginning from 1893, large numbers of cattle died from so-called "Bracken Poisoning", In certain years, specially in drought years, the mortality in cattle population caused considerable anxiety to farmers. "Bracken" was therefore considered generally by local farmers as a menace to stock. Yet, the controversial nature of the many aspects of the problem, will be evident from the brief review of the existing literature, an attempt to present which is made in the first part of this thesis. The disease first noticed by its mysterious appearance in this country in 1897 by Penberthy has remained a mystery till the present day in view of the highly controversial nature of the problem and the lack of sufficient data. It was therefore thought essential to carry out systematic investigations into the cause of the disease mainly from nutritional and biochemical aspects

Dietary Phytase: an ideal approach for a cost effective and low-polluting aquafeed

Global fishmeal production from wild-catch sources cannot continue to increase indefinitely; suitable alternatives have to be found for sustainable aquaculture. Plant-based aquafeed seems to be the ideal alternative to this, but has its own limitations. Plant ingredients are rich in phytic acid, which reduces the bioavailability of nutrients like minerals and protein to the fish, thereby causing aquaculture pollution. Dietary phytase treatment reduces the aquaculture pollution by improving the bioavailability of nutrients, and reduces the feed cost as evident from poultry and piggery. Phytase activity is highly dependent upon the pH of the gut. Unlike mammals, fish are either gastric or agastric, and hence, the action of dietary phytase varies from species to species. In this article, the authors attempt to summarise various effects of phytase on nutrient utilization, growth of fish and aquatic pollution

Arsenic level in the surface wastewaters of Kolkata and its implication on sewage-fed fisheries

Arsenic pollution is a major threat in eastern India and Bangladesh. In Kolkata, sewage-fed fishery is a very popular culture. Wastewater of Kolkata city is diluted with freshwater and used in sewage-fed fish ponds. In the present study the arsenic concentration in the surface wastewater from forty-four different places of southern, eastern, western and norther parts of Kolkata was estimated. In fifteen places, the arsenic level was higher than the allowed limit (0.20 mg/l). But the arsenic level in the waters, sediment of fish culture ponds and in fish flesh of sewage-fed fisheries of Kolkata was below the maximum limit. So, till date there is no threat from arsenic pollution to the sewage-fed fisheries of Kolkata

A psychometric study of engineering and architectural drawings, with emphasis on the selection of pupils and students for technical education

An educational psychology thesis analysing technical and artistic abilities of pupils selected for technical education. Attempting to bridge the gap between the designer and the psychologist, the author makes a psychometric study of architectural and engineering drawing. Draftsmanship calls for practical intelligence. The draftsman needs, above all, the ability to think in-terms of space. He must be able to think in solid and to transfer an object from three to two dimensions and vice versa. Artistic ability does not play an important part in draftsmanship at the early stage of training

Period dependent temperature and ambient index effects on long period fibre gratings

The ambient index and temperature effects on the spectral profiles of two sets of long period gratings (LPGs) of different periods were investigated. The shorter period LPGs were found to be more sensitive than the longer period LPGs over identical ambient index ranges but less sensitive over identical temperature ranges. The coupling wavelength shifts due to temperature are also seen to be linear and in opposite directions in each set of LPGs and unlike the ambient index shifts there seems to be no obvious modal dependency with respect to sensitivity in any individual LPG. The conclusion to this investigation is that it may be possible to design an LPG of such a period that parts of the spectral profile are unaffected by temperature whilst maintaining a reasonable ambient index sensitivity

A novel multi-criteria group decision-making approach using aggregation operators and weight determination method for supplier selection problem in hesitant Pythagorean fuzzy environment

Uncertainty is an important factor in the decision-making process. Hesitant Pythagorean fuzzy sets (HPFS), a combination of Pythagorean and hesitant fuzzy sets, proved as a significant tool to handle uncertainty. Well-defined operational laws and attribute weights play an important role in decision-making. Thus, the paper aims to develop new Trigonometric Operational Laws, a weight determination method, and a novel score function for group decision-making (GDM) problems in the HPF environment. The approach is presented in three phases. The first phase defines new operational laws with sine trigonometric function incorporating its special properties like periodicity, symmetricity, and restricted range hence compared with previously defined aggregation operators they are more likely to satisfy the decision maker preferences. Properties of trigonometric operational laws (TOL) are studied and various aggregation operators are defined. To measure the relationship between arguments, the operators are combined with the Generalized Heronian Mean operator. The flexibility of operators is increased by the use of a real parameter λ to express the risk preference of experts. The second phase defines a novel weight determination method, which separately considers the membership and non-membership degrees hence reducing the information loss and the third phase conquers the shortcomings of previously defined score functions by defining a novel score function in HPFS. To further increase the flexibility of defined operators they are extended in the environment with unknown or incomplete attribute weights. The effectiveness of the GDM model is verified with the help of a supplier selection problem. A detailed comparative analysis demonstrates the superiority, and sensitivity analysis verifies the stability of the proposed approach

Design and Simulation of Extended Interaction Cavities for a Ka band Multi beam Klystron

This article reports about the design approach, electromagnetic simulation and analysis results of high-frequency ladder-type input, output, and intermediate RF cavaties for Ka-band multi-beam extended interaction klystron. Several parameters of the cavity, such as quality factor, shunt impedance, etc., have been investigated by the assistance of electromagnetic software CST microwave studio