Some considerations on methods for spatially aggregating and disaggregating soil information

Some possible approaches to the aggregation and disaggregation of soil data and information are presented as an opener to the more detailed discussion. The concepts of hierarchy, grain, extent, scale and variability are discussed. Slight modifications to the Hoosbeek-Bryant scheme to deal with spatial and temporal scales and various types of quantitative models are suggested. Approaches to aggregation or upscaling are reviewed. The contributions of representative elementary volume (REV), variograms, fractal theory, multi-resolution analysis using wavelets, critical point phenomena, renormalisation groups and transfer functions are discussed followed by a brief presentation of some ecological approaches including extrapolation by lumping, extrapolation by increasing model extent and extrapolation by explicit integration. A clear distinction must be made between additive and non-additive variables. The scaling of the former is much less problematic than the latter. Corroboration of any approach by testing against the aggregated values seems problematic. Methods of disaggregation or downscaling including transfer functions, mass-preserving or pycnophylactic methods are also discussed. In order to make quantitative advances, nested sampling or reanalysis of data in land information systems to obtain variance information over a complete range of scales is required. Finally an appeal is made for work to begin on a quantitative scale-explicit theory of soil variation.     

Standard-relevant publications: evidence,processes and influencing factors

Scientometrics - This paper introduces the concept of standard-relevant publications, complementary to standard-essential patents and framed by the concept of knowledge utilization. By analyzing...     

Clad-modified fiber optic sensor utilizing CdS nanoflower as cladding for the detection of ethanol

Nowadays, sensing and detection of ethanol is paramount one for numerous applications including production of ethanol, fuel processing, chemical processing in industry, traffic management, food package testing for safety and medical applications. On the other hand, the rapid growth of nanotechnology paves the way to develop highly sensitive, portable and low-cost sensors with less power consumption. In line with this fact, a cladding modified fiber optic ethanol sensor using CdS nanoflower has been reported in the present study. CdS nanoflower was prepared by one step hydrothermal synthesis and subjected for various characterization techniques to investigate the material properties. The sensor probe was developed viz cladding modification technology followed by dip coating of CdS nanoflower over an unclad section of an optical fiber. The potency of CdS nanoflower has been probed for 0–300 ppm of acetone, ethanol, methanol and isopropanol at ambient environment. The sensing results demonstrates that the sensor coated with CdS nanoflower manifested better sensing performances towards ethanol (~?4.6% at 300 ppm) with response/recovery of 90 s and 100 s than other gases. The unique sensing feature complied that CdS nanoflower is desirable candidate in effective quantification of ethanol.

     

PEDOT:PSS nano-gels for highly electrically conductive silver/epoxy composite adhesives

In this work, we report a methanol-facilitated approach to directly use aqueous Poly(3,4-ethylenedioxythiophene):Poly(styrene sulfonate) (PEDOT:PSS) in the silver/epoxy composites for preparation of highly electrically conductive adhesives (ECAs) and an investigation of the interaction between PEDOT:PSS nano-gels and silver microflakes. PEDOT:PSS nano-gel (18?<?d?<?30 nm) aqueous dispersion is immiscible with epoxy resin and difficult to incorporate into the conventional silver-filled ECAs. To overcome this challenge, we used methanol to facilitate the dispersion of PEDOT:PSS and silver microflake in epoxy resin. The synergetic interactions between PEDOT:PSS and silver and the effect of methanol were investigated using dynamic light scattering (DLS), atomic force microscopy, Kelvin probe force microscopy, and scanning electron microscope. When PEDOT:PSS was exposed to methanol, its morphology changed from coil to coil/linear structure; the contact potential difference between silver microflake and PEDOT:PSS increased from 9.47 to 22.56 mV, showing an increased conductivity between PEDOT:PSS and silver microflake. It was found that the introduction of a small amount of PEDOT:PSS (0.1 wt%) to the conventional ECA with 60 wt% silver microflake remarkably improved the electrical conductivity from 104 to 386 S/cm. A significantly high conductivity of 2526 S/cm was achieved by further increasing the PEDOT:PSS concentration to 1 wt%. The impact of PEDOT:PSS on the adhesive bonding strength towards copper substrate was also examined; the bonding strength slightly decreased when <?1 wt% PEDOT:PSS was used, but abruptly dropped when PEDOT:PSS content was further increased beyond 1 wt%. The incorporation of the optimal 1 wt% PEDOT:PSS into conventional ECAs with 60% silver microflake greatly increased the electrical conductivities by 25 times with limited impact on the shear strength. The results provide insights to the synergetic interplay of conductive polymer and metallic fillers, and might have profound technical implications on the development of advanced conductive composites.     

Influence of the starting condition on the kinetics of sensitization and loss of toughness in an AISI 304 steel

This work describes the investigation of the embrittlement of AISI 304 steel sensitized at 650°C by Charpy impact test, comparing two starting conditions: (1) mill annealed and machined (MA-M); and (2) solution treated at 1050°C by 1 h followed by oil quenching (ST). The degree of sensitization for both samples was assessed by Optical Microscopy (OM), Scanning Electron Microscopy (SEM) and by Double Loop Electrochemical Potentiodynamic Reactivation test. The results showed that MA-M samples undergo more severe and rapid embrittlement than ST ones and a higher kinetics of sensitization due to small strains concentrated in grain boundaries and martensite phase produced during the machining operations. The martensite phase is found to be quite stable at the sensitization treatment at 650°C. The increase of microvoids nucleation at the grain boundaries seems to be the mechanism of embrittlement in the sensitized 304 steel.     

Displacement estimation with co-registered ultrasound for image guided neurosurgery: a quantitative in vivo porcine study

Brain shift during open cranial surgery presents a challenge for maintaining registration with image-guidance systems. Ultrasound (US) is a convenient intraoperative imaging modality that may be a useful tool in detecting tissue shift and updating preoperative images based on intraoperative measurements of brain deformation. We have quantitatively evaluated the ability of spatially tracked freehand US to detect displacement of implanted markers in a series of three in vivo porcine experiments, where both US and computed tomography (CT) image acquisitions were obtained before and after deforming the brain. Marker displacements ranged from 0.5 to 8.5 mm. Comparisons between CT and US measurements showed a mean target localization error of 1.5 mm, and a mean vector error for displacement of 1.1 mm. Mean error in the magnitude of displacement was 0.6 mm. For one of the animals studied, the US data was used in conjunction with a biomechanical model to nonrigidly re-register a baseline CT to the deformed brain. The mean error between the actual and deformed CT's was found to be on average 1.2 and 1.9 mm at the marker locations depending on the extent of the deformation induced. These findings indicate the potential accuracy in coregistered freehand US displacement tracking in brain tissue and suggest that the resulting information can be used to drive a modeling re-registration strategy to comparable levels of agreement.     

Invariants of electromechanical coupling coefficients in piezoceramics

The relationships between coefficients of electromechanical coupling (CEMC) of various types of piezoceramic resonator (PR) vibrations are considered. Being constant for a given piezoceramic state, the range of variation of piezoceramics dielectric permittivity from a mechanically "free" condition at relatively low frequencies up to an "overall clamped" condition at high frequencies is determined by a consecutive "clamping", caused by a complex of CEMCs of various particular vibrational modes peculiar to the resonator. As the difference between "free" and "overall clamped" permittivities is always determined by the maximal piezomaterial /spl kappa//sub i3/ coupling coefficient, the difference does not depend on the path that was gone through the low-high frequency range, which includes all the vibrational modes possible for a particular PR. The influence of the piezoelectric and elastic anisotropy of lead-zirconate-titanate (PZT) piezoceramic materials on relative CEMC variations was experimentally investigated.     

Cognitive demands of collision avoidance in simulated ship control

The study examines the cognitive demands of collision avoidance under a range of maritime scenarios. Operators used a PC-based radar simulator to navigate set courses over 100 6-min trials varying in collision threat and traffic density. Corrective maneuvers were made through the application of standard navigation rules and by using two decision aids (target acquisition and test maneuver). Results showed widespread effects of collision threat in terms of decision aid use, subjective workload, and secondary task performance. Most notably, demand increased markedly over the course of emergency trials, in which collision threat resulted from rule violation by target vessels. The findings are discussed in terms of the comparison between predictable demands (requiring standard course changes) and those involving uncertainty about the others' intentions (involving more intensive monitoring and forced delays in corrective action). The study has relevance for the design of collision avoidance systems, specifically for the use of ecological displays.     

Achieving Dependability in the Configuration, Integration and Testing of Healthcare Technologies

This paper presents two case studies, which highlight the practical work involved in developing and deploying dependable healthcare systems. It shows how dependability is a thoroughgoingly practical, contexted achievement. We show how dependability is an outcome of the reasoning and argumentation processes that stakeholders engage in, in situations such as design and testing. What becomes relevant during these interactions stands as the dependability criteria that must be achieved. Furthermore, we examine the way in which different dependability criteria need to be managed, and even relatively prioritised, before finally discussing the types of work this provokes at the boundaries of organisations, particularly when integrating work and technologies.     

DOLAR: virtualizing heterogeneous information spaces to support their expansion

Users expect applications to successfully cope with the expansion of information as necessitated by the continuous inclusion of novel types of content. Given that such content may originate from ‘not‐seen thus far’ data collections and/or data sources, the challenging issue is to achieve the return of investment on existing services, adapting to new information without changing existing business‐logic implementation. To address this need, we introduce DOLAR (Data Object Language And Runtime), a service‐neutral framework which virtualizes the information space to avoid invasive, time‐consuming, and expensive source‐code extensions that frequently break applications. Specifically, DOLAR automates the introduction of new business‐logic objects in terms of the proposed virtual ‘content objects’. Such user‐specified virtual objects align to storage artifacts and help realize uniform ‘store‐to‐user’ data flows atop heterogeneous sources, while offering the reverse ‘user‐to‐store’ flows with identical effectiveness and ease of use. In addition, the suggested virtual object composition schemes help decouple business logic from any content origin, storage and/or structural details, allowing applications to support novel types of items without modifying their service provisions. We expect that content‐rich applications will benefit from our approach and demonstrate how DOLAR has assisted in the cost‐effective development and gradual expansion of a production‐quality digital library. Experimentation shows that our approach imposes minimal overheads and DOLAR‐based applications scale as well as any underlying datastore(s). Copyright © 2011 John Wiley & Sons, Ltd.