CAD Tool Design for NCL and MTNCL Asynchronous Circuits

This thesis presents an implementation of a method developed to readily convert Boolean designs into an ultra-low power asynchronous design methodology called MTNCL, which combines multi-threshold CMOS (MTCMOS) with NULL Convention Logic (NCL) systems. MTNCL provides the leakage power advantages of an all high-Vt implementation with a reasonable speed penalty compared to the all low-Vt implementation, and has negligible area overhead. The proposed tool utilizes industry-standard CAD tools. This research also presents an Automated Gate-Level Pipelining with Bit-Wise Completion (AGLPBW) method to maximize throughput of delay-insensitive full-word pipelined NCL circuits. These methods have been integrated into the Mentor Graphics and Synopsis CAD tools, using a C-program, which performs the majority of the computations, such that the method can be easily ported to other CAD tool suites. Both methods have been successfully tested on circuits, including a 4-bit × 4-bit multiplier, an unsigned Booth2 multiplier, and a 4-bit/8-operation arithmetic logic unit (ALU

How Fragrant are perfumes? A Micro Perspective from Middle East

Satisfaction is a consumer post-purchase evaluation of the overall service experience. As an important determinant of customer loyalty and retention, firms exhibit most care to maintain customer satisfaction intact, unless it cannot be up-scaled. Middle East is known for its fancy towards cosmetics in general and perfumes in particular. The present study, which was conducted as micro level, undertaken in the Kingdom of Bahrain, attempts to understand the customer satisfaction of perfumes. The study discusses, inter alia, brand consciousness, brand loyalty, loyalty towards vending outlets etc.Customer satisfaction, perfume market, brand consciousness, brand loyalty, shop loyalty, consumer exploitation, purchase behaviour, buying motive

Coral reef fish abundance and diversity of seagrass beds in Kavaratti atoll, Lakshadweep, India

The community organization of coral reef fishes in the seagrass sub-habitat of Kavaratti toll, Lakshadweep, India was studied during the period from January 1991 to June 1992. Twenty-seven families represented by 65 species were recorded by the visual censes method. The community diversity for families and species was 2.49 and 3.14 respectively. Juveniles and sub-adults of the most adult reef fish, which inhabit other sub-habitats, were recorded here. The high species diversity in the seagrass beds is due to their roles as nurseries, shelter and foraging grounds for many species. Labridae, Chaetodontidae, Acanthuridae and Mullidae were the most speciose families. Ocurrence of siganids was highly seasonal. The cover that seagrass canopy provides conceals many species and perhaps influenced counts. The occurrence of balistids could be related to the presence of interstitial and patches and abundant invertebrate food. Scorpaenids subsisted on abundant invertebrates and juveniles fishes. High counts and pronounced variations make seagrass beds unstable habitats. However, monsoon assemblages were relatively stable perhaps due to lack of excessive new recruits and a habitat shift by most species

Frequency Response of Fluid Transmission Lines with a Nonlinear Boundary Condition

Mechanical Engineerin

Passive Thermal Management of Launch Vehicle Systems using Phase Changing Materials

Electronic systems in expendable launch vehicles and missiles rely on their own thermal inertia to operate for the stipulated time, without overheating, owing to absence of active cooling systems and natural convection at elevated altitude. Traditionally, this inertia is built-into the electronics by increasing its chassis (support structure) mass, proportional to the associated thermal load. For power intensive systems, especially in vehicle upper stages where mass is at premium, this approach results in reduction in payload capability. In the proposed paper, a Heat Sink based on Neopentyl Glycol (NPG) with solid-to-solid phase change (crystalline transformation) is explored as a mass effective alternative due to the material’s capability to absorb a significant amount of energy during phase change. However, due to its lower thermal conductivity, a Thermal Conductivity Enhancer (TCE) to maximize heat transfer had to be employed. The resulting heat sink, utilizing TCE for heat transfer capability and NPG for heat storage capability is called as Hybrid Heat Sink. A heat sink with plate type fins as TCE is realized and a mass reduction factor of 1.4 is achieved against traditional approach. This is followed by a heat sink with pin type fins as TCE where mass reduction factor is increased to 2.6. Effect of thermal cycling and vibration on its performance is also studied

Habitat distribution and species diversity of coral reef fishes in the reefslope of the Kavaratti atoll, Lakshadweep, India

Habitat distribution and species diversity of coral reef fishes in the reef slope of Kavaratti atoll was studied by the visual census method during January 1991 to June 1992. Twenty seven families represented by 121 species, the highest for any sub-habitat of the atoll were recorded. The community diversity, also the highest both for families and species was 3.32 and 4.45 respectively. Family assemblages were not stable between censuses and pre-monsoon, mon- soon and post-monsoon seasons. Labridae, Chaetodontidae, Balistidae, Pomacentridae and Acanthuridae were the most specious families. Low abundance of coral feeders indicated unhealthy reef condition. While dominance of some surgeonfish indicated availability of al- gal food, balistids provided clues for topographic complexity

Community organization of reef fishes in the live coral sub-habitat of Kavaratti atoll, Lakshadweep, India

Data on the community organization of coral reef fishes of Kavaratti atoll, Lakshadweep, India were collected during the period January 1991 to June 1992. Species were enumerated by visual census on the live coral sub-habitat for frequency of occurrence, abundance, composition, diversity, evenness and seasonal variation in community parameters. As the live coral zone was composed of a single species of ramose coral (Acropora formosa), only 14 families and 39 species of reef fishes made use of this zone, the community diversity being 1.84 and 3.16. Chaetodontids, labrids and pomacentrids were comparatively more abundant. Varying habitats of chaetodontids explain their restricted distribution. Live coral does not seem to be a preferred habitat of labrids. The occurrence of epinephelids was influenced by readily available prey. Most species among live coral were resident, variations resulted from factors affecting new recruits rather than habitat shifts

Community organization of coral reef fishes in the rubble sub-habitat of Kavaratti Atoll, Lakshadweep, India

A visual census of the coral reef fishes, conducted during January 1991 to June 1992, indicated the occurrence of 64 species belonging to fifteen families in the rubble sub-habitat of Kavaratti A toll (Lat. 10°33'N; Long. 7Z038'E) in Lakshadweep. The community diversity for families and species was 2.68 and 3.58 respectively. Family assemblages were not stable during different seasons. Labridae and pomacentridae made use of the rubble zone efficiently. Pomacentrids were characteristically site attached but varied in relative abundance. Rhinecanthus aculeatus among balistids depended on rubble for food and nesting sites. The occurrence of chaetodontids was due to their flexible feeding habits, in the absence of coral cover. Availability of food strongly determined the distribution of the surgeonfish, Acanthurus triostegus. The abundant turf algae harbored by rubble attracted schools of sub-adult herbivores resulting in variations

Occurrence of juvenile fishes on the seagrass beds of Kavaratti Atoll, Lakshadweep, India

In the atolls of Lakshadweep, juveniles of Acanthuridae and Labridae were most abundant on seagrass beds, the former during pre-monsoon and postmonsoon periods and the latter in pre-monsoon. Schooling species showed variable recruitment. Non-schooling species were rare. Peak settlement was observed during pre-monsoon and post-monsoon seasons. Continuous occurrence of juveniles in different size ranges confirms the continuous spawning habits. Chaetodontids and holocentrids occurred consistently round the year. Seasonality in occurrence was most pronounced in Carangidae and Siganidae, but not so in Apogonidae, Lutjanidae and Mullidae. Seasonal abundance of juveniles was influenced by summer peaks, timing and magnitude of settlement, adult spawning and local migrations. Abundance of larvae increased with salinity. Juvenile abundance, independent of environmental parameters seemed to be controlled by seasons, tides and currents. Lunar phases and abundance of juveniles were found to be co-related