Study of dielectric properties of RbNO3 single crystals

Dielectric properties, dielectric constant (k), dielectric loss (tan δ) and a.c. conductivity (σ) in the solution-grown single crystals of RbNO₃ are presented from room temperature to about 200°C covering the frequency range 10² to 10⁵ Hz. A broad peak observed in tan δ-frequency data between 10³ and 10⁵Hz is thought to be due to impurity-vacancy dipoles. The sudden rise of three parameters near 160°C is attributed to the known phase transition from trigonal to CsCl structure.     

Integration of product design,process planning,scheduling, and FMS control using XML data representation

An efficient model for communications between CAD, CAPP, and CAM applications in distributed manufacturing planning environment has been seen as key ingredient for CIM. Integration of design model with process and scheduling information in real-time is necessary in order to increase product quality, reduce the cost, and shorten the product manufacturing cycle. This paper describes an approach to integrate key product realization activities using neutral data representation. The representation is based on established standards for product data exchange and serves as a prototype implementation of these standards. The product and process models are based on object-oriented representation of geometry, features, and resulting manufacturing processes. Relationships between objects are explicitly represented in the model (for example, feature precedence relations, process sequences, etc.). The product model is developed using XML-based representation for product data required for process planning and the process model also uses XML representation of data required for scheduling and FMS control. The procedures for writing and parsing XML representations have been developed in object-oriented approach, in such a way that each object from object-oriented model is responsible for storing its own data into XML format. Similar approach is adopted for reading and parsing of the XML model. Parsing is performed by a stack of XML handlers, each corresponding to a particular object in XML hierarchical model. This approach allows for very flexible representation, in such a way that only a portion of the model (for example, only feature data, or only the part of process plan for a single machine) may be stored and successfully parsed into another application. This is very useful approach for direct distributed applications, in which data are passed in the form of XML streams to allow real-time on-line communication. The feasibility of the proposed model is verified in a couple of scenarios for distributed manufacturing planning that involves feature mapping from CAD file, process selection for several part designs integrated with scheduling and simulation of the FMS model using alternative routings.     

Identification of Natural Products as Potential Pharmacological Chaperones for Protein Misfolding Diseases

Defective protein folding and accumulation of misfolded proteins is associated with neurodegenerative, cardiovascular, secretory, and metabolic disorders. Efforts are being made to identify small-molecule modulators or structural-correctors for conformationally destabilized proteins implicated in various protein aggregation diseases. Using a metastable-reporter-based primary screen, we evaluated pharmacological chaperone activity of a diverse class of natural products. We found that a flavonoid glycoside ( C-10 , chrysoeriol-7-O-β-D-glucopyranoside) stabilizes metastable proteins, prevents its aggregation, and remodels the oligomers into protease-sensitive species. Data was corroborated with additional secondary screen with disease-specific pathogenic protein. In vitro and cell-based experiments showed that C-10 inhibits α-synuclein aggregation which is implicated in synucleinopathies-related neurodegeneration. C-10 interferes in its structural transition into β-sheeted fibrils and mitigates α-synuclein aggregation-associated cytotoxic effects. Computational modeling suggests that C-10 binds to unique sites in α-synuclein which may interfere in its aggregation amplification. These findings open an avenue for comprehensive SAR development for flavonoid glycosides as pharmacological chaperones for metastable and aggregation-prone proteins implicated in protein conformational diseases.     

Experimental Measurement of Impact Pressures Delivered by Oral Water Irrigation Devices

Water irrigation devices (WID's) are widely used in homes and dental clinics across the country for oral hygiene. There have been several reported cases of tissue damage with the use of these devices. In the present investigation, two commercially available oral water irrigation devices were evaluated using engineering techniques. The impact thrusts delivered by these devices were measured at different control settings. Both of the tested commercial oral water irrigation devices were found to exert abnormally high thrust which could cause serious damage to the sulcular epithelium and the underlying tissues. These pressures are far in excess of the pressure intensity necessary to perform the cleaning action. Moreover, the existing designs using reciprocating pumps are unsafe and are potentially dangerous, particularly with small diameter tips.     

Molecular Modeling and Molecular Dynamics Studies of Hydralazine with Human DNA Methyltransferase 1

A series of DNA methyltransferase 1 (DNMT1) inhibitors were modeled by docking and molecular dynamics studies to rationalize their activity. Our findings will be valuable in guiding research efforts toward the rational design and virtual screening of novel DNMT inhibitors.

     

Thermal Behavior in Rectangular Channel Duct Fitted With V-Shaped Perforated Baffles

An experimental investigation has been carried out to study the heat transfer and friction factor characteristics of a V-down-perforated baffled roughened solar air heater duct. The roughened wall was uniformly heated and the rest three walls of the duct were kept insulated. Measurements have been carried out for the duct aspect ratio of 10, Reynolds number range of 3800–19,000, relative hole position range of 0.429–0.571, relative roughness pitch range of 2–4, and open area ratio range of 12–44%. The relative roughness height of 0.4 and angle of attack of 60° are kept constant during the entire experimentation. The heat transfer and friction factor data obtained were compared with the data obtained from a smooth duct under similar operating conditions. In comparison to the smooth duct the V-shaped perforated baffle roughened duct enhanced the Nusselt number and friction factor by 2.57 and 5.96 times, respectively. The thermohydraulic performance parameter is found superior for the open area ratio of 24% and relative roughness pitch of 2.5.     

Issues in Foreign Outsourcing

The decision to outsource applications development and support to a foreign vendor involves not only the myriad issues pertinent to outsourcing in general, but a host of additional risks and challenges unique to firms operating in different legal and cultural environments. Careful assessment of these issues helps determine whether offshore outsourcing will realize its potential to reduce costs, improve software quality, and achieve economies of scale in skills acquisition.