Three-component turbulence measurements using a four-wire probe

A probe, consisting of two orthogonal X-wire probes, allows all three velocity fluctuation components to be measured simultaneously. Attractive features of the probe include its ease of construction, the use of a standard yaw–pitch calibration and the potential to correct for spatial resolution. The reliability of this probe was assessed using measurements in the near-field of a plane jet and in the self-preserving region of a cylinder wake. Statistics of all three components compare favourably with those obtained, though not simultaneously, using standard X-wires.     

Statistical Nonparametric Model for Natural Salt Estimation

Many rivers in the Western U.S. suffer from high salinity content due to both natural and human-induced causes. Computer simulation models are often used to estimate future salinity levels and identify mitigation needs. To date, estimation of future natural salt loading has utilized linear relationships between natural flow and natural salt. We develop a nonparametric regression technique to fit a functional relationship between natural flow and natural salt. The main advantages of the nonparametric technique are: (1) No prior assumptions have to be made as to the underlying form of the relationship and (2) any arbitrary relationship (linear or nonlinear) can be modeled. In addition, we develop a resampling scheme to provide confidence intervals of the natural salt estimates from the nonparametric model. We apply this model to data from a stream gauge at Glenwood Springs, Colo., on the Colorado River. We show that the new natural salt model reduces the average overprediction of salt mass shown in the existing natural salt model for the period 1941–1995 by approximately 15% (78,000?metric?tons).     

Importance Sampling-Based Unscented Kalman Filter for Film-Grain Noise Removal

Photographic film contains film-grain noise that translates to multiplicative, non-Gaussian noise in the exposure domain. A method based on the unscented Kalman filter can suppress this noise while simultaneously preserving edge information.     

Capacity performance of dynamic provisioning in optical networks

This paper describes an architecture and analyzes the performance of dynamic provisioning of lightpaths in an optical network. In dynamic provisioning, a lightpath is set up in real-time without rearranging the working and protection routes of existing lightpaths, and without the knowledge of future lightpath provisioning events. This paper develops a general model of the physical topology of the optical network, and outlines routing approaches for dynamic provisioning of lightpaths. It analyzes via simulations the performance of dynamically provisioned unprotected, 1+1 protected and mesh-restored lightpaths. The analysis of the efficiency of network utilization of dynamic provisioning focuses on the spare capacity needed for protection, and in particular focuses on the impact of sharing of wavelength channels for mesh-restored lightpaths. The main conclusion from the performance studies is that significant capacity gains are achieved with sharing of wavelength-channels for mesh-restored lightpaths with dynamic provisioning even for sparse topologies, and even at moderate loads     

Studies on the electric discharge compaction of metal powders

Consolidation and densification of metal powder are usually attained by compaction followed by prolonged high-temperature sintering or by hot pressing. However, these methods are not suitable where grain growth is to be avoided. So electric discharge compaction is being studied so as to establish a fast, cheap, and reproducible process. In this process, high current pulse for a few millisecond duration is passed through metal powder compacts held under pressure in a die. This paper gives the details of the investigation being carried out to establish the process parameters for the densification of titanium, tin and zinc powders. Remarkable improvements in the density and microstructure are noticed after subjection to the electric discharge.     

Symptom relief with amitriptyline in the irritable bowel syndrome

An assay was developed for the specific detection of Escherichia coli O157 using PCR, because O serological cross-reactivities have been reported between E. coli O157 and some E. coli, other bacterial species. PCR amplification of E. coli O157 rfbE (Ec O157:H7) gene that is necessary for the expression of the O157 antigen, was performed for the identification of E. coli O157. All Shiga toxin-producing Escherichia coli (STEC) O157:H7 and O157:H, non-STEC O157 strains were positive, and other non-O157 E. coli strains were negative by PCR. All tested strains of other bacterial species, like Salmonella O30 and Citrobacter freundii which gave positive results with O157 detection kits, were negative by PCR. It is recommended that PCR amplification of O157 rfbE gene is one of the most specific method for E. coli O157 identification.     

Novel euglycemic and hypolipidemic agents. 1

A series of [[(heterocyclyl)ethoxy]benzyl]-2,4-thiazolidinediones have been synthesized by the condensation of corresponding aldehyde 1 and 2,4-thiazolidinedione followed by hydrogenation. Both unsaturated thiazolidinedione 2 and its saturated counterpart 3 have shown antihyperglycemic activity. Many of these compounds have shown superior euglycemic and hypolipidemic activity compared to troglitazone (CS 045). The indole analogue DRF-2189 (3g) was found to be a very potent insulin sensitizer, comparable to BRL-49653 in genetically obese C57BL/6J-ob/ob and 57BL/KsJ-db/db mice. Pharmacokinetic and tissue distribution studies conducted on BRL-49653 and DRF-2189 (3g) indicate that these drugs are well-distributed in target tissues. On the basis of euglycemic activity as well as enhanced selectivity against reduction of triglycerides in plasma, DRF-2189 (3g) has been selected for further evaluation.     

A framework for creating hybrid-open source software communities

Abstract The open source software (OSS) model is a fundamentally new and revolutionary way to develop software. The success of the OSS model is also setting the stage for a structural change in the software industry; it is beginning to transform software industry from manufacturing to a service industry. Despite the success of the OSS model, for‐profit organizations are having difficulty building a business model around the open source paradigm. Whereas there are some isolated empirical studies, little rigorous research has been done on how traditional organizations can implement and benefit from OSS practices. This research explores how organizations can foster an environment similar to OSS to manage their software development efforts to reap its numerous advantages. Drawing on organizational theory, we develop a framework that guides the creation and management of a hybrid‐OSS community within an organization. We discuss the implications of this framework and suggest areas for future research.     

Pressure induced structural phase transition in SnS — An ab initio study

The structural behaviour of SnS under pressure has been investigated by first principle density functional calculations of the total energy by the TB-LMTO approach. We find that SnS undergoes a structural phase transition from orthorhombic type to monoclinic type structure around 17 GPa which is in good agreement with the recent experimental study. In addition, the ground state properties are computed and compared with the available results.