On the receptivity and non-parallel stability of travelling disturbances in rotating disk flow

The generation and evolution of small amplitude wavelength traveling disturbances in rotating disk flow is discussed. The steady rotational speed of the disk is perturbed so as to introduce high frequency oscillations in the flow field. Secondly, surface imperfections are introduced on the disk such as roughness elements. The interaction of these two disturbances will generate the instability waves whose evolution is governed by parabolic partial differential equations that are solved numerically. For the class of disturbances considered (wavelength on the order of Reynolds number), it is found that eigensolutions exist which decay or grow algebraically in the radial direction. However, these solutions grow only for frequencies larger than 4.58 times the steady rotational speed of the disk. The computed receptivity coefficient shows that there is an optimum size of roughness for which these modes are excited the most. The width of these roughness elements in the radial direction is about .1 r(sub 0) where r(sub 0) is the radial location of the roughness. It is also found that the receptivity coefficient is larger for a negative spanwise wavenumber than for a positive one. Typical wave angles found for these disturbances are about -26 degrees

Disconnected Topology Space

A more general definition of extremally µ-disconnected generalized topological space [3] is introduced and its properties are studied. We have further improved the definitions of generalized open sets [1] and upper(lower) semi-continuous functions defined for a generalized topological space in [5]. In this generalized framework we obtain the analogues of results in [1, 3, 5]. Examples of extremally µ-disconnected generalized topological spaces are given

Fuzzy Arithmetic and Extension Principle

Fuzzy arithmetic is an extensively used instrument for dealing with uncertainty in a computationally competent method, recently and much better in the upcoming years. This thesis aims to investigate the basic properties of fuzzy arithmetic as its title implies. The properties of fuzzy arithmetic definitions, examples are discussed. Here we investigates the properties of fuzzy sets, properties of fuzzy number, performing arithmetic operations on fuzzy number, properties of L-R fuzzy number, performing operations on L-R fuzzy number, properties of fuzzy interval and properties of L-R fuzzy interval. Also, the extension principle and fuzzy arithmetic operations using extension principle are investigated. The fuzzy equation is solved by using the method o

The Structure of Commutayive Banach Algebra

Let A be a Banach algebra over C with norm In this note, several characterizations of commutativity of A are given. For instance, it is shown that A is commutative if or if the spectral radius on A is a norm

Fuzzy Hypergraphs

Graph theory has found many application area in science, engineering, and mathematics. In order to expand the application base, the notion of a graph was generalized to that of a hypergraph, that is, a set X of vertices together with a collection of subsets of X. In this chapter, we fuzzify the notation of a hypergraph and state some possible applications. In this article, we apply the concept of bipolar fuzzy sets to hypergraphs and investigate some basic theorems and some properties of bipolar fuzzy hypergraphs. Some basic concepts of bipolar fuzzy set are defined. It is shown that any bipolar fuzzy graph can be expressed as the bipolar fuzzy intersection graphs of some bipolar fuzzy sets

Some recent observations on small-scale fishery In the vicinity of Madras

Madras zone is one of the important fishing centres on the east coast of India. To understand the fish landings from different gears in Madras, three landing centres, viz., Kasimedu, Triplicane and Nochikuppam were selected. Kasimedu is about 8 km north of Triplicane and Nochikuppam is about 2 km south of Triplicane. The major catch components from the demersal trawls of this area arc silver bellies, threadfin breams, sciaenids, lizardfish, prawns, squids and cuttlefish. These groups are landed in a meagre quantity by the traditional gears, thus maintaining compatability between mechanised and non-mechanised gears in the exploitation of fishery resources off Madras

Acoustic Receptivity of Mach 4.5 Boundary Layer with Leading- Edge Bluntness

Boundary layer receptivity to two-dimensional slow and fast acoustic waves is investigated by solving Navier-Stokes equations for Mach 4.5 flow over a flat plate with a finite-thickness leading edge. Higher order spatial and temporal schemes are employed to obtain the solution whereby the flat-plate leading edge region is resolved by providing a sufficiently refined grid. The results show that the instability waves are generated in the leading edge region and that the boundary-layer is much more receptive to slow acoustic waves (by almost a factor of 20) as compared to the fast waves. Hence, this leading-edge receptivity mechanism is expected to be more relevant in the transition process for high Mach number flows where second mode instability is dominant. Computations are performed to investigate the effect of leading-edge thickness and it is found that bluntness tends to stabilize the boundary layer. Furthermore, the relative significance of fast acoustic waves is enhanced in the presence of bluntness. The effect of acoustic wave incidence angle is also studied and it is found that the receptivity of the boundary layer on the windward side (with respect to the acoustic forcing) decreases by more than a factor of 4 when the incidence angle is increased from 0 to 45 deg. However, the receptivity coefficient for the leeward side is found to vary relatively weakly with the incidence angle

EFFECT OF INORGANIC FERTILIZERS AND PRESSMUD COMPOST ON SOIL PROPERTIES, YIELD AND QUALITY OF BHENDI

A field experiment was conducted at farmer`s field in Sivapuri village, Chidambaram taluk, Cuddalore district, Tamil Nadu to study the effect of inorganic fertilizers and pressmud compost on soil properties, yield and quality of bhendi cultivar Arka anamika as a test crop. The experimental soil was sandy clay loam with a pH of 7.20, EC of 0.64 dSm-1 and CEC of 19.20 c mol (p+) kg-1. The results of the experiment clearly revealed that the application of 100% recommended dose of fertilizer+15 tonnes of pressmud compost ha-1 (T4) registered the maximum fruit and stover yield of bhendi the same treatment T4 improved the quality attributes of bhendi viz., crude protein content, ascorbic acid content and crude fibre content. The available N, P, K and S content in the post harvest soil was maximum in the treatment T4. This treatment was followed by application of 75% recommended dose of fertilizer+15 tonnes of pressmud compost ha-1 (T7) regarding yield and quality attributes, as well as available nutrients status of post harvest soil. However, these two treatments were comparable to each other

Prof D. T. Mook

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Analysis of Coverage in LoRa using secured IoT Systems

Long Range (LoRa) is an unlicensed Low Power Wide Area Network for the application of the Internet of Things (IoT). This LoRa technology is mainly suitable for smart city applications since this technology consumes low power, low cost, and transfer information over a long distance. This technology proposes a new communication standard to tackle discrete IoT applications. This technology works based on Chirp Spread Spectrum (CSS) technique with a larger bandwidth. LoRa deploys the whole channel bandwidth to transmit the signal which results in, to avoid channel noise, Doppler impacts, and fading. This paper mainly focuses on the impact of three parameters namely, Code Rate (CR), Spreading Factor (SF), Bandwidth (BW). Furthermore, analysis the effect of the data rate and transmission time using Code Rate (CR), Spreading Factor (SF), and Bandwidth to extend coverage