Unconventional Environments Research Articles

Random Walker Coverage Analysis for Information Dissemination in Wireless Sensor Networks

The increasing technological progress in electronics provides network nodes with new and enhanced capabilities that allow the revisit of the traditional information dissemination (and collection) problem. The probabilistic nature of information dissemination using random walkers is exploited here to deal with challenges imposed by unconventional modern environments. In such systems, node operation is not deterministic (e.g., does not depend only on network nodes’ battery), but it rather depends on the particulars of the ambient environment (e.g., in the case of energy harvesting: sunshine, wind). The mechanism of information dissemination using one random walker is studied and analyzed in this paper under a different and novel perspective. In particular, it takes into account the stochastic nature of random walks, enabling further understanding of network coverage. A novel and original analysis is presented, which reveals the evolution network coverage by a random walker with respect to time. The derived analytical results reveal certain additional interesting aspects regarding network coverage, thus shedding more light on the random walker mechanism. Further analytical results, regarding the walker’s spatial movement and its associated neighborhood, are also confirmed through experimentation. Finally, simulation results considering random geometric graph topologies, which are suitable for modeling mobile environments, support and confirm the analytical findings.

Risk Aversion, Uncertainty, and Monetary Policy in Unconventional Environments

Using traditional monetary policy measures, Bekaert et al. (2013) show that a lax monetary policy decreases both risk aversion and uncertainty and that positive shocks to risk aversion and uncertainty induce monetary policy changes. We extend their analysis for the pre-crisis period to the post-crisis period using recently developed monetary policy measures that take unconventional environments into consideration. Empirical findings show that the results of Bekaert et al. (2013) persist for the post-crisis period only when such monetary policy measures are applied.

ACCURACY ASSESSMENT OF UNDERWATER PHOTOGRAMMETRIC THREE DIMENSIONAL MODELLING FOR CORAL REEFS

Abstract. Recent advances in automation of photogrammetric 3D modelling software packages have stimulated interest in reconstructing highly accurate 3D object geometry in unconventional environments such as underwater utilizing simple and low-cost camera systems. The accuracy of underwater 3D modelling is affected by more parameters than in single media cases. This study is part of a larger project on 3D measurements of temporal change of coral cover in tropical waters. It compares the accuracies of 3D point clouds generated by using images acquired from a system camera mounted in an underwater housing and the popular GoPro cameras respectively. A precisely measured calibration frame was placed in the target scene in order to provide accurate control information and also quantify the errors of the modelling procedure. In addition, several objects (cinder blocks) with various shapes were arranged in the air and underwater and 3D point clouds were generated by automated image matching. These were further used to examine the relative accuracy of the point cloud generation by comparing the point clouds of the individual objects with the objects measured by the system camera in air (the best possible values). Given a working distance of about 1.5 m, the GoPro camera can achieve a relative accuracy of 1.3 mm in air and 2.0 mm in water. The system camera achieved an accuracy of 1.8 mm in water, which meets our requirements for coral measurement in this system.

ACCURACY ASSESSMENT OF UNDERWATER PHOTOGRAMMETRIC THREE DIMENSIONAL MODELLING FOR CORAL REEFS

Recent advances in automation of photogrammetric 3D modelling software packages have stimulated interest in reconstructing highly accurate 3D object geometry in unconventional environments such as underwater utilizing simple and low-cost camera systems. The accuracy of underwater 3D modelling is affected by more parameters than in single media cases. This study is part of a larger project on 3D measurements of temporal change of coral cover in tropical waters. It compares the accuracies of 3D point clouds generated by using images acquired from a system camera mounted in an underwater housing and the popular GoPro cameras respectively. A precisely measured calibration frame was placed in the target scene in order to provide accurate control information and also quantify the errors of the modelling procedure. In addition, several objects (cinder blocks) with various shapes were arranged in the air and underwater and 3D point clouds were generated by automated image matching. These were further used to examine the relative accuracy of the point cloud generation by comparing the point clouds of the individual objects with the objects measured by the system camera in air (the best possible values). Given a working distance of about 1.5 m, the GoPro camera can achieve a relative accuracy of 1.3 mm in air and 2.0 mm in water. The system camera achieved an accuracy of 1.8 mm in water, which meets our requirements for coral measurement in this system.

Examination of unconventional phenomena in naturally fractured liquid-rich gas reservoirs: single-block compositional model

During the depletion of liquid-rich gas reservoirs, the gas condenses as the pressure inside the reservoir reduces below the hydrocarbon dew-point pressure, which introduces retrograde condensate. In such conditions, the productivity experiences a reduction in recovery due to the appearance of condensate near the production channels. This work is aimed to provide insight on productivity characteristics of a liquid-rich gas system in unconventional environments and extend the scrutiny on the propagation of condensate while activating capillary forces and diffusion. The impact of capillary pressure on phase behavior was explored using an in-house generated coupled phase behavior model with a capillary pressure equation. The influence of capillary pressure was examined against different sets of composition combinations in different reservoir settings. Capillary force extents were highly dependent on composition combinations and pore throat radiuses. Mixtures with higher volatile concentrations showed the highest capillary forces. The enhancement in condensate propagation, resistance to gas flow, and impact on recovery were explored at 10- and 20-nm pore throat sizes. The investigation suggested that interfacial tensions implied greater influence on the flow behavior in oil-dominated systems than in gas-dominated conditions. Evaluating the flow performance of unconventional phenomena in liquid-rich gas reservoirs was extended to include diffusion while activating capillary forces. The results showed higher domination of diffusion on reservoir performance, which provided additional fluid recovery. Subsequently, the enhanced withdrawal of fluid dismissed the impact of capillary forces on gas flow and the impact of condensate blockage.

DIFFERENCES OF ANTIBACTERIAL ACTIVITY SPECTRA AND PROPERTIES OF BACTERIOCINS, PRODUCED BY GEOBACILLUS SP. BACTERIA ISOLATED FROM DIFFERENT ENVIRONMENTS

Ability of bacteriocins to inhibit pathogenic bacteria may depend on the environment inhabited by the producing strain. However, there are just few reports on bacteriocin-producing thermophilic bacteria from unconventional environments. Therefore, in this work we investigated differences in antibacterial activity spectra of microorganisms isolated from two different environments: the oil wells (first collection) and surface soil above the oil pools (second collection). All strains were Gram-positive, rod-shaped, thermophilic and endospore forming bacteria. Using spot-on-lawn method we have demonstrated that strains from the second collection possess higher and broader antibacterial activity spectra than first collection strains. Furthermore, all strains were active against at least 1 of 19 tested pathogenic bacteria. Analysis of antibacterial compounds has shown that all of them were stable in broad temperature and pH ranges, sensitive to proteolytic enzymes, proving their proteonaceus nature. They were all secreted during the exponential growth phase and active against closely related thermophilic bacteria, which suggest that these substances are most likely bacteriocins. Most of the bacteriocins had molecular masses under 20 kDa. Plasmid isolation and elimination experiments suggest that bacteriocins are most likely chromosome-encoded. Our results confirm the differences between antibacterial spectra of bacteriocins produced by bacterial strains isolated from different environmental niches.

The Proto-Fuse project: methods to boost creativity for architects

Human civilization can be ameliorated by human creativity. Innovation and progress of human civilization result from a change in our thinking patterns, thus, potentially transforming the present into a creative future. Accentuating the role of creativity in design even more than other disciplines pushes one to underpin the understanding of creativity as a key role player in architecture. Furthermore, by identifying the basic principles of our ingenuity/creativity, researchers might be able to enhance this ability in the future. The digital era allows for a new domain of architectural experience. It is assumed that new designs in virtual environments can be created that go beyond the mere accommodation of literal functions, and affect human experiences. This paper presents the role of a method developed by the authors: ‘Proto-Fuse’, experimented with, as an artwork for the survey of cognitive perception of humans, specifically targeting enhancement of spatial creativity. The logic behind this method is based on two psychological concepts: 1 – conceptual blending, 2 – tolerance of ambiguity. Two experimental projects were conducted for exploring the Proto Fuse method: (a) “unconventional virtual environments (UVEs)” to improve conceptual blending and (b) “Extracting local distance” to enhance tolerance of ambiguity.The paper concludes with an implementation scenario of the Proto-Fuse method in the pedagogy of architecture and elaborates on the results of the projects and analysis of the feedbacks received during the project session.

A Context-aware Decision Support Tool for Assessing and Mitigating Drivers of Civil Instability

Military planners and decision-makers face a number of challenges with the shift towards operating within diverse, multi-dimensional, and unconventional environments. Leaders require a deeper understanding of the broader social and civil context in which operations occur, including the underlying factors that contribute to instability and the drivers of conflict. This understanding is often derived through the analysis of textual data. Both traditional and non-traditional sources – such as news articles, blog entries, and tweets – represent a vast amount of data that can be brought to bear on problems ranging from measuring the progress of missions to forecasting important changes in the environment. The volume and velocity of this data requires processing tools that can help users understand the concepts and events being discussed. Additionally, these data are inherently ambiguous, and the automated processing techniques necessary for aggregating and analyzing data may introduce further uncertainty. The validity and veracity of data, sources, assumptions, and conclusions must be carefully considered prior to action. Planners and decision-makers require new, data-driven tools that aid in selecting the best course of action through interactive exploration and assessment processes. In this paper, we describe an ongoing research and development effort to create a context-driven, web-based tool that aids planning and decision-making by providing a more comprehensive understanding of the civil component of operational environments. This tool allows users to rapidly find, organize, and assess complex data across multiple phases of civil information management. This includes: (1) researching and assessing civil vulnerabilities; (2) developing plans to address identified vulnerabilities; and (3) tracking ongoing trends and progress towards goals and objectives. Our tool assists the user in each phase by collecting, processing, and recommending data and analyses that are contextually relevant to their task. By offloading data collection, supporting data organization, and providing personalized recommendations, our tool allows users to focus their efforts on verifying, interpreting, and assessing the information needed to recommend the best course of action.

Measuring the Stance of Monetary Policy in Conventional and Unconventional Environments

This article introduces an idea for summarizing of the stance of monetary policy with quantities derived from a class of yield curve models that respect the zero lower bound constraint for interest rates. The stimulus measure aggregates the current and estimated expected path of interest rates relative to the neutral interest rate from the yield curve model. Unlike shadow short rates, economic stimulus measures are consistent and comparable across conventional and unconventional monetary policy environments, and are less subject to variation with modelling choices, as I demonstrate with two and three factor models estimated with different data sets. Full empirical testing of the inter-relationships between ES measures and macroeconomic data remains a topic for future work.

Implementing Unconventional Virtual Environments for Enhancing Creativity in Architecture Pedagogy

What can be extracted as a common definition amongst near 100 different definitions of creativity according to different disciplines is: Creativity is a new combination of what you have in your inventory of experiences + intuition. It can be considered that expanding the inventory of experiences can gradually help in novel combination of experiences and intuition. To support and promote such an expansion, experiencing a virtual environment (VE) with unconventional spatial characteristics offers to be an interesting case. VE’s can help in detaching one self from the real-world as regards the sense of time, matter and physical constraints, thus enabling a designer to embody and expand into a new palette of inventory.The authors thus hypothesize from a cognitive point of view that extensiveness extensiveness of experience gained by surfing in unconventional virtual environments can positively be related to both creative performance (enhance interactivity, lateral thinking, idea generation and creativity-supporting cognitive processes (retrieval of unconventional knowledge, recruitment of ideas from unconfined virtual environment for creative idea expansion). The authors also believe that creating a new perception of spatial environment as the first step of architecture pedagogy can be of vital impetus in expanding the educator’s ideas. As a practical suggestion the authors suggest conducting praxis based workshops besides the main academic curriculum in which designers can design, surf, play, manipulate unconventional virtual environment, totally free of any constrains in an immersive, interactive virtual environment.

Enzyme Microheterogeneous Hydration and Stabilization in Supercritical Carbon Dioxide

Supercritical carbon dioxide is a promising green-chemistry solvent for many enzyme-catalyzed chemical reactions, yet the striking stability of some enzymes in such unconventional environments is not well understood. Here, we investigate the stabilization of the Candida antarctica Lipase B (CALB) in supercritical carbon dioxide-water biphasic systems using molecular dynamics simulations. The preservation of the enzyme structure and optimal activity depend on the presence of small amounts of water in the supercritical dispersing medium. When the protein is at least partially hydrated, water molecules bind to specific sites on the enzyme surface and prevent carbon dioxide from penetrating its catalytic core. Strikingly, water and supercritical carbon dioxide cover the protein surface quite heterogeneously. In the first solvation layer, the hydrophilic residues at the surface of the protein are able to pin down patches of water, whereas carbon dioxide solvates preferentially hydrophobic surface residues. In the outer solvation shells, water molecules tend to cluster predominantly on top of the larger water patches of the first solvation layer instead of spreading evenly around the remainder of the protein surface. For CALB, this exposes the substrate-binding region of the enzyme to carbon dioxide, possibly facilitating diffusion of nonpolar substrates into the catalytic funnel. Therefore, by means of microheterogeneous solvation, enhanced accessibility of hydrophobic substrates to the active site can be achieved, while preserving the functional structure of the enzyme. Our results provide a molecular picture on the nature of the stability of proteins in nonaqueous media.

An Orbital Prediction Algorithm for LEO Satellites Based on Optical Observations of Short Arcs at Single Station

The forecasting technique of the target tracking based on the short arcs at single station is an important way to guarantee that high-precision photoelectric theodolites can normally track and capture the targets in unconventional environments. We construct the tracking prediction algorithm based on nonlinear filter, which can provide the guiding data for the closed loop tracking under normal circumstances. At the same time we also construct the target prediction algorithm based on the nonlinear transformation, without valid observational data, which can provide a track guidance for the theodolite and ensure that the targets will not be lost. It is demonstrated that the nonlinear filtering is more effective than the EKF (extended Kalman filter) in the tracking prediction algorithm of the short arcs at single station. The results indicate that the nonlinear filter designed in this paper can be used as the guiding algorithm for the optical tracking equipments. And its guiding accuracy is in the same order of magnitude of the theodolite's random measurement accuracy. When the systematic error of the equipments reaches 50″, the accuracy can achieve 20″ for predictions in 60 s. This still satisfies the requirement of the field of view of the tracking equipments.

Metal-to-Metal Seals Meet Downhole Hazard Demands

Technology Update As oil and gas production activities continue to shift toward more hostile and unconventional environments, such as reservoirs with high-pressure/high-temperature (HP/HT) or very acidic characteristics, the use of elastomeric sealing materials in wells and subsea piping face limits to their durability and reliability. Seal failure can have major safety and environmental consequences, as well as resulting in costly repairs and lost production. The record of failures of critical liner-hanger seals in HP/HT completions, for example, has become a large concern. Operators globally have been adopting the most rigorous quality-assurance procedures for these seals to prevent dangerous and costly incidents. As many as 18% of offshore wells worldwide are estimated to have some form of weak-ness or uncertainty in their integrity. This includes a sizable number of abandoned wells that may repressurize and leak through damaged or poor cement jobs. Rubber-based seals are used throughout the production industry. However, they begin to break down in HP/HT reservoirs, in downhole settings high in H2S or CO2, or in thermal-recovery applications where temperatures may approach 600°F. In addition, rubber-based seals on retrievable devices can be damaged and compromised by downhole debris, including during retrieval operations. In response to the shifts occurring in the producing environment, and to other downhole operating risks, metal-to-metal (MTM) sealing technology capable of withstanding extreme temperatures and pressures—and debris impact as well—has been developed by Caledyne. MTM technology provides the safe, cost-effective seals needed in packers, bridge plugs, flange seals, and other components for many of the most challenging projects to proceed (Fig. 1). Metal-To-Metal Seal Systems These MTM systems employ a flexible metal seal, rather than an elastomer, as their external sealing element to contact the surrounding tubing or pipe and form a tight, durable seal that withstands HP/HT and corrosive-fluid conditions in the well even when they are changing and volatile. To achieve the needed flexibility, the metal sealing element houses silicon-based filler that is stable at temperatures above 644°F—with higher-temperature filler currently being tested. The MTM seals are certified to ISO 14310, the international standard for oil and gas industry downhole equipment, and performance-rated to more than 15,000 psi at 572°F. Available in a wide range of sizes, MTM seals can be installed indefinitely and in most cases will last as long as the pipe. In addition to their technical benefits, MTM seals provide a commercial advantage because each seal is suitable for any downhole condition, regardless of temperature, pressure, corrosive reservoir environment, or the chemicals injected downhole. Thus stock levels of seal equipment can be minimized. Case Study: Retrievable MTM Bridge Plug Deployment A Caledyne-manufactured retrievable bridge plug (RBP), incorporating the MTM seal, was deployed successfully for Talisman recently on the Bunga Kekwa project in Malaysia to temporarily plug the BKC-20 gas well (Fig. 2).

Thermodynamics of proteins in unusual environments

Some aspects of protein thermodynamics in unconventional environments are addressed and discussed. Aqueous medium, especially dilute solution is the ‘usual’ ambient, which mediates all the interactions between protein and nearby molecules. When the water content is low, the surroundings may be considered ‘unusual’, exerting new stresses on the protein molecule and demanding different responses and property changes. The unusual systems considered in this article are low-water protein environments, including nearly dry state powders, organic solvent dispersions and reverse micelles' inclusions. The changes of hydration experienced by the protein after immobilization on solid supports are emphasized with respect to the free bulk solution state. Finally, the aqueous medium altered by water connectivity perturbing agents (polysaccharides) or in macromolecular crowding conditions (in the presence of polyols) is also considered as highly not ideal protein environments. The different responses elicited by the protein under the stress induced by drastic surrounding alterations may give insights for the controlled exploitation of the protein's biological and thermodynamic properties.

Capacity for Training in Clinical Research: Status and Opportunities

The ability to base patient care on scientific evidence depends in part on the results of translational and applied research. The shortage of trained clinical researchers identified by several sources limits the availability of clinical research studies upon which to base evidence-based therapeutics. This premise suggests that the dental profession needs to train more clinical researchers and faculty to conduct clinical research and to teach its applications to practice. Increasing opportunities for clinical research training in a variety of settings should eventually increase the numbers of clinical researchers, raise faculty involvement in clinical research, and promote science transfer. This paper reports on the current status of clinical research in dental schools, specifies the diverse groups involved in the clinical research enterprise, and identifies underutilized opportunities and partnerships for clinical research training. Data on federal and nonfederal funding of clinical research and training programs are presented. Existing and novel mechanisms for expanding clinical research training throughout and across traditional as well as unconventional environments are explored.

Span of Command and Control in US Army Organizations

An important aspect of designing any organization is the concept of span of command and control (SOCC). No where is this situation clearer than in military organizations. This paper describes research designed to examine the relationship between factors that have been identified as affecting the effectiveness of SOCC and the difficulty of command and control in Army organizations. The project team interviewed 11 Army General officers regarding issues involving SOCC during operations that occurred in unconventional environments and 44 officers from Captain to Lieutenant General regarding war fighting operations. The interviews were structured around seven factors: Task Characteristics, Organizational Structure, Complexity of the Environment, History or Unit Contiguity, Technological Innovation, Individual Differences, and External Organizations. The data collected consisted of the comments made during the interviews, the results of a content analysis of those comments, and, for war fighting operations only, ratings on the impact of each factor on the difficulty of command and control. Both sets of data were examined as a function of the respondent's position in the organizational hierarchy and the type of unit to which the respondent was assigned. The results show an interacting effect of SOCC factor, echelon, and type of unit on the difficulty of command and control. A report, in preparation, will summaries these results and present conclusions and recommendations for organizing Army units based on the results.

Multi-phase bioelectrochemical sensors

Interest in operating bioelectrochemical sensors in unconventional environments such as non-polar water-immiscible organic solvents has led to new concepts in biosensor design. This brief review considers the evolution of an approach to electrochemical measurement using thin ionically conducting films at the surface of closely spaced microelectrodes. The ability to support all the elements normally associated with the bioelectrochemistry of catalytic proteins at a semi-rigid ionic matrix leads to a robust sensor configuration capable of operating in non-polar solvents such as hexane or directly in gases. Such multi-phase sensors are expected to be of particular utility in environmental monitoring where measurements need to be made in water and air samples.

Organization and Management of Critical Care Systems in Unconventional Situations

Critical care medicine is a field of medicine using the highest concentration of expensive diagnostic and life-support technology for the benefit of a single individual. Conventional use of this resource and specialty is clearly understood, despite the fact that it is not necessarily comparable among different institutions. Some of the major issues in using critical care as a medical tool during extraordinary stress on the hospital, and the potential for using it in unconventional environments outside an established institution, have been reviewed. It is clear that the expertise and multidisciplinary approach can be of great use in disaster response, and a national effort toward integrating critical care into overall medical response is in progress.