On the shock transition, the hydraulic jump, and vortex breakdown

The normal shock, hydraulic jump, and vortex breakdown have a common feature: they are all marked by a transition from a supercritical to a subcritical flow state. These phenomena are due to the nonlinearity of the flow, and it will be shown that viscosity also plays an essential role. This paper demonstrates explicitly how viscosity enters into these flows, The treatment of normal shock served a starting illustration. Then an equation governing the phenomenon of hydraulic jump is derived with the inclusion of the effect of viscosity. It is explicitly shown that supercritical flow is not stable and has to go through a transition to a conjugate subcritical flow state downstream. Similar treatment is also applied to vortex breakdown with largely similar results

Understanding and mapping water resources by multidimensional statistics and fuzzy logic: Missouri River basin case

Time series from 46 gauging station with drainage areas from 113 to 398 sq mi in the Upper Missouri River basin with mutual period of observation from 1963 to 1991 were used for analysis. Factor analysis of average annual flow revealed five patterns of river runoff within four distinct subregions of the territory (east, two carbonate karsts areas, uplands). This factor model reflected 62% variance of initial matrix. Each of four groups of watersheds obtained as a factor was presented by one gauging station with time series of annual and monthly discharges (I- 06218500, II- 06478690, III- 06412500, and IV- 06323000). Streams represented by patterns I, II and IV have increase of values and those represented by III have a decrease. The positive trend for pattern II is statistically significant. For four typical flow records, monthly average values were obtained from three to four seasons composed of different ensembles of months. The trends for seasonal components were analyzed for four typical watersheds and a significant increase was obtained for fall-winter season for type IV. Stream runoff is the most appropriate regional indicator for hydroclimatological processes. With multidimensional statistics this process can be considered as spatiotemporal structure of different scale of landscape properties and dynamics. Uncertainties of process originating stream runoff based on dynamic of regional meteorological system and diversity of local landscapes. Boundaries for domains with different annul and seasonal regimes of stream runoff were defined with factor loadings and fuzzy logic rules. With case of Missouri River basin presented that more complete decryption of real events in nature requires use probability and fuzzy logic together

The effect of heat compression on mechanical behaviour and moisture content of pineapple leaf fibre and sugarcane bagasse waste for plate disposal

The waste from farming and industry could be reduced and used as raw materials in construction to achieve sustainable technologies. This study focuses on the use of waste products from the pineapple leaf and sugarcane bagasse as compounds in replacing polystyrenes and others plastics glass in the manufacture of plate disposal. This platter is made from pineapple leaf and sugarcane bagasse by six (6) series of mixtures with different percentages namely series 1 (20% of pineapple leaf), series 2 (30% of pineapple leaf) series 3 (40% of pineapple leaf), series 4 (60 % of pineapple leaf), series 5 (70% of pineapple leaf) and series of 6 (80% of pineapple leaf). Two (2) series is N8T2 (80% of pineapple leaf and 20 % sugarcane bagasse waste) and N2T8 (20% of pineapple leaf and 80% sugarcane bagasse waste) focusing on this study for furthermore understanding the effect of replacing plate disposal from pineapple laef fiber and sugarcane bagasse waste material. A platter hot press machine is built with variable adjustment temperature on the surface of the mold according parameters required are 50°C, 100°C and 150°C. The effect of heat compression on physical and mechanical behavior of the pineapple leave and sugarcane bagasse waste plate disposal was evaluated. From observation and results showed the best roughness surface appearance on N2T8.The Optimum percentage pineapple leaf and sugarcane bagasse waste is good present at heat parameter 50°C for specimen N2T8. The best water absorption on specimen series N8T2 because pineapple leaf potential to hydroscopic and water resistance. It can be concluded that pineapple leaf and sugarcane bagasse waste have potential raw material for strength and lightweight of paper disposal composition applications

Adapting ACME to the database caching environment : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Information Systems at Massey University

The field of database cache replacement has seen a great many replacement policies presented in the past few years. As the challenge to find the optimal replacement policy continues, new methods and techniques of determining cache victims have been proposed, with some methods having a greater effect on results than others. Adaptive algorithms attempt to adapt to changing patterns of data access by combining the benefits of other existing algorithms. Such adaptive algorithms have recently been proposed in the web-caching environment. However, there is a lack of such research in the area of database caching. This thesis investigates an attempt to adapt a recently proposed adaptive caching algorithm in the area of web-caching, known as Adaptive Caching with Multiple Experts (ACME), to the database environment. Recently proposed replacement policies are integrated into ACME'S existing policy pool, in an attempt to gauge its ability and robustness to readily incorporate new algorithms. The results suggest that ACME is indeed well-suited to the database environment, and performs as well as the best currently caching policy within its policy pool at any particular point in time in its request stream. Although execution time increases by integrating more policies into ACME, the overall time saved increases by avoiding disk reads due to higher hit rates and fewer misses on the cache

Building a truster environment for e-business : a Malaysian perspective

Internet identify ‘security’ as a major concern for businesses. In general, the level of security in any network environment is closely linked to the level of trust assigned to a particular individual or organization within that environment. It is the trust element that is crucial in ensuring a secure environment. Besides physical security, security technology needs to be utilised to provide a trusted environment for e-business. Network security components for perimeter defense, i.e., Virtual Private Networks, firewalls and Intrusion Detection Systems, need to be complemented by security components at the applications and user level, e.g., authentication of user. ID or password security solution may be an option but now with the availability of legally binding digital certificates, security in e-business transactions can be further improved. Time and date stamping of e-business transactions are also of concern to prove at a later date that the transactions took place at the stipulated date and time. Digital certificates are part of a Public Key Infrastructure (PKI) scheme, which is an enabling technology for building a trusted epvironment. PIU comprise policies and procedures for establishing a secure method for exchanging information over a network environment. The Digital Signature Act 1997 (DSA 1997) facilitates the PKI implementation in Malaysia. Following the DSA 1997, Certification Authorities (CAs) were set up in Malaysia. This paper describes a trusted platform for spurring ebusiness and provides a Malaysian perspective of it