Coordination Models Based on a Formal Model of Distributed Object Reflection

We propose a family of models of coordination of distributed object systems representing different views, with refinement relations between the different views. We start with distributed objects interacting via asynchronous message passing. The semantics of such a system is a set of event partial orders (event diagrams) giving the interactions during possible system executions. A global coordination requirement is a constraint on the allowed event diagrams. A system coordination specification consists of a meta-level coordinator that controls message delivery in the system according to a given global policy. The system-wide coordination can be refined/distributed using coordinators for disjoint subsystems that communicate with their peers to enforce the global policy. By a further transformation the meta-level can be replaced by systematically transformed base-level objects communicating via a controller object. The coordination models are formalized in rewriting logic using the Reflective Russian Dolls model of distributed object reflection. The general ideas are illustrated with several examples.     

Full-Scale Field Testing of Colloidal Silica Grouting for Mitigation of Liquefaction Risk

This paper reports results of a full-scale field test to assess the performance of dilute colloidal silica stabilizer in reducing the settlement of liquefiable soil. Slow injection methods were used to treat a 2-m-thick layer of liquefiable sand. Eight injection wells were installed around the perimeter of the 9-m-diameter test area and 8% by weight colloidal silica grout was slowly injected into the upper 2?m of a 10-m-thick layer of liquefiable sand. A central extraction well was used during grout injection to direct the flow of the colloidal silica towards the center of the test area. Details of the field injection are described. Subsequently, the injection wells were used to install explosive charges and liquefaction was induced by blasting. After blasting, approximately 0.3?m of settlement occurred versus 0.5?m of settlement in a nearby untreated area. The mechanism of improvement is thought to be bonding between the colloidal silica and the individual sand particles; the colloidal silica gel encapsulates the soil structure and maintains it during dynamic loading.     

The influence of caffeine on nicotine's discriminative stimulus, subjective, and reinforcing effects.

Caffeine may acutely alter the discriminative stimulus and subjective effects of nicotine, perhaps explaining the association of coffee intake with smoking status. In this study, smokers were initially trained to discriminate 20 μg/kg nicotine by nasal spray from placebo (0). Then, generalization of nicotine discrimination was tested, using both 2- and 3-choice ("novel" option) procedures, across a range of doses (0-20 μg/kg) following pretreatment with 0, 2.5, and 5.0 mg/kg caffeine p.o. Nicotine reinforcement was assessed after the end of generalization testing using a choice procedure. Caffeine pretreatment did not alter nicotine discrimination and self-administration. Caffeine and nicotine influenced some subjective and cardiovascular responses, but there were no interaction effects except for diastolic blood pressure. These results do not support the notion that caffeine acutely alters nicotine's discriminative stimulus, subjective, or reinforcing effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Current challenges in hydrate-based desalination: Kinetic and thermodynamic perspective

Water scarcity is becoming a severe problem worldwide due to inadequate freshwater resources and swift population growth. Seawater desalination is one of the vital approaches to meet the demand for freshwater. However, energy and associated costs with conventional seawater desalination techniques are incentivizing non-conventional water desalination processes. Water desalination using gas hydrates formation is one of the emerging non-conventional processes. In this perspective article, recent advances in hydrate-based seawater desalination (HBSD) have been critically analyzed to outline a future path towards a clean and efficient hydrate-based desalination process. It provides a detailed comparison of various processes developed over decades, and measured desalination efficiencies with their process details. Moreover, the current challenges, limitations, and future perspectives of hydrate-based desalination are also discussed. The study also recapitulates the thermodynamics and kinetics aspects of the hydrate-based desalination process. In addition, various factors controlling the desalination efficiencies, such as control of the separation of hydrate crystals, salt deposition on hydrate particles, and hydrate morphology, were thoroughly investigated with their proposed process designs. The kinetics of hydrate formation is also assessed, with the possibility of a zero-induction regime and its consequent impact on hydrate morphology. The current capabilities of the thermodynamics models (Gibbs energy minimization + electrolyte equation of state) were discussed using various commercially available software. Additionally, the role of hydrate promotors is also discussed, which can reduce the higher cost associated with the hydrate-based desalination process.     

Lessons learned from a woodstove changeout on the Nez Perce Reservation

A woodstove changeout program was conducted within 16 homes on the Nez Perce Reservation in Idaho to evaluate the effectiveness of a woodstove changeout in improving indoor air quality. PM_2.5 samples were collected within the common area (rooms where the stoves were located) of the homes both before and after the installation of cleaner burning EPA-certified stoves. During the pre- and post-changeout sampling, indoor PM_2.5 mass, Organic Carbon (OC), Elemental Carbon (EC), and chemical markers of woodsmoke (including levoglucosan) were measured.Sampling results from this study showed that indoor air quality was improved in 10 of the 16 homes following the woodstove changeout and educational training program. Five homes had increased indoor PM_2.5 concentrations following the changeout, while one home did not have final PM_2.5 results for comparison. The median pre-changeout PM_2.5 mass (as measured by TSI DustTraks) was 39.2 μg/m³, with a median post-changeout concentration of 19.0 μg/m³. This resulted in an overall 52% reduction in median indoor PM_2.5, a 36% reduction in mean indoor PM_2.5 and a 60% reduction in PM_2.5 spikes when the old stoves were replaced with EPA-certified stoves. Another significant finding of the project was that targeted education and outreach is a critical component of the overall success of the program. Effective messaging to homeowners on proper use of their new stove is a necessary task of a woodstove changeout.     

Influence of policy support on the development of organic farming in the European Union

The paper explores the influence of policy support on the development of the organic sector. Policies include the agri‐environment programme (EU Regulation 2078/92), the EU regulation 2092/91 defining organic crop‐production in statutory terms and policies to support market and regional development and the information provision of organic farming. Policy makers have been interested in organic farming for its environmental and health benefits and the potential to contribute to the goals of regional development programmes. The evaluation suggests that the variation in support policies alone cannot explain the different rates of conversion to organic farming in the EU.     

A Monte Carlo study of the impact of missing data and differential item functioning on theta estimates from two polytomous Rasch family models

This paper examines the impact of differential item functioning (DIF), missing item values, and different methods for handling missing item values on theta estimates with data simulated from the partial credit model and Andrich's rating scale model. Both Rasch family models are commonly used when obtaining an estimate of a respondent's attitude. The degree of missing data, DIF magnitude, and the percentage of DIF items were varied in MCAR data conditions in which the focal group was 10% of the total population. Four methods for handling missing data were compared: complete-case analysis, mean substitution, hot-decking, and multiple imputation. Bias, RMSE, means, and standard errors of the theta estimates for the focal group were adversely affected by the amount and magnitude of DIF items. RMSE and fidelity coefficients for both the reference and focal group were adversely impacted by the amount of missing data. While all methods of handling missing data performed fairly similarly, multiple imputation and hot-decking showed slightly better performance.     

Standardization of models and methods used to assess nanoparticles in cardiovascular applications

Nanotechnology has the potential to revolutionize the management and treatment of cardiovascular disease. Controlled drug delivery and nanoparticle-based molecular imaging agents have advanced cardiovascular disease therapy and diagnosis. However, the delivery vehicles (dendrimers, nanocrystals, nanotubes, nanoparticles, nanoshells, etc.), as well as the model systems that are used to mimic human cardiac disease, should be questioned in relation to their suitability. This review focuses on the variations of the biological assays and preclinical models that are currently being used to study the biocompatibility and suitability of nanomaterials in cardiovascular applications. There is a need to standardize appropriate models and methods that will promote the development of novel nanomaterial-based cardiovascular therapies.