Tele-maintenance “intelligent” system for technical plants result management

The management of technical plant for productivity and safety is generally a complex activity, particularly when many plants distributed in the territory are considered (i.e. the more and more frequent case of outsourced plants maintenance by specialized companies), granted quality and cost results are required (i.e. the case of some rather innovative contract solutions) and the technology involved is heterogeneous and innovative (i.e. electro-mechanical plants).In order to efficiently achieve the above aims an “intelligent” maintenance-management system for the distant monitoring and controlling by a remote control center has been developed. The so-called GrAMS (granted availability management system) system is conceived to give to organizations involved in technical-industrial plants management the possibility to tend to a “well-known availability” and “zero-failures” management.In particular, this study deals with the diagnostic aspects and safety level of technical plants (such as elevators, thermo-technical plants, etc.), and with the involvement of ad hoc designed software analysis tools based on neural networks and reliability indicators.Part of the research dealing with the tele-maintenance intelligent system has been financed by the Italian High Institute for Safety (ISPESL) and led to the development of a pre-industrial prototype whose realization and testing is here described.     

区域性能源管理中心平台建设(英文)

Based on the analysis of different requirements of energy management center construction and the data acquisition of various industries in wide area network, as well as the practices of real-time online system, the paper puts forward the construction scheme of regional energy management center(REMC) which can achieve real time online monitoring of organizations' energy consumption via data collection, and also proposes the design idea of energy data acquisition based on national standards.     

Analysis of stress concentration during tension of round pultruded composite rods: Errata

“Analysis of stress concentration during tension of round pultruded composite rods (Composite Structures 2008;83:100–109)” had several errors without negative impact on the main results except for one. A sign error in Eq. (11) results in a tensile radial stress rather than compression in Fig. 6 according to the parameters provided in the article.     

Knowledge sharing over the network

This paper addresses an overview of “knowledge management” from business management/social science perspectives and information technology perspectives, including ongoing research of “knowledge sharing approach towards information retrieval”. We usually use various knowledge when facing practical problems, and transfer it to others for re-use. Such features are investigated for long-time period, and some are characterized and understood by terms such as “SECI model”, “the wisdom of crowds”, “knowledge-centric” and so forth. Information technology provides several functionalities to enhance knowledge management methodology from usable computer system points of views. Through research on knowledge sharing, some hints are provided this research area.     

Statistical evaluation of local to regional snowpack stability using simulated snow-cover data

Snow stability, or the probability of avalanche release, is one of the key factors defining avalanche danger. Most snow stability evaluations are based on field observations, which are time-consuming and sometimes dangerous. Through numerical modelling of the snow cover stratigraphy, the problem of having sparsely measured regional stability information can be overcome. In this study we compared numerical model output with observed stability. Overall, 775 snow profiles combined with Rutschblock scores and release types for the area surrounding five weather stations were rated into three stability classes. Snow stratigraphy data were then produced for the locations of these five weather stations using the snow cover model SNOWPACK. We observed that (i) an existing physically based stability interpretation implemented in SNOWPACK was applicable for regional stability evaluation; (ii) modelled variables equivalent to those manually observed variables found to be significantly discriminatory with regard to stability, did not demonstrated equal strength of classification; (iii) additional modelled variables that cannot be measured in the field discriminated well between stability categories. Finally, with objective feature selection, a set of variables was chosen to establish an optimal link between the modelled snow stratigraphy data and the stability rating through the use of classification trees. Cross-validation was then used to assess the quality of the classification trees. A true skill statistic of 0.5 and 0.4 was achieved by two models that detected “rather stable” or “rather unstable” conditions, respectively. The interpretation derived could be further developed into a support tool for avalanche warning services for the prediction of regional avalanche danger.     

From mono- to polytopic interactions via hydrogen bonds — Capacitive sensor studies

Supra molecular materials can be generated via hydrogen bonding between monomers. This leads either to “monotopic” molecules as well as self-assemblies of a restricted number of complementary components as “di-” or “polytopic” molecules with more than one functional unit. The latter structures grow spontaneously by self organization and in principle consist of repeatedly branched chain molecules analogous to dendrimers. When disturbing these aggregates by analyte molecules (e.g. volatile organic compounds), the supra molecular structures break down leading to a pronounced change in dielectric behavior that is detectable with inter digital capacitors. “Monotopic”-materials show linear behavior with increasing analyte concentration whereas “polytopic” molecules lead to properties resembling a threshold sensor.     

Crack kinking from an initially closed, ordinary or interface crack, in the presence of friction

One theoretically studies crack kinking from an ordinary crack (in some homogeneous solid) or an interface crack (between two dissimilar materials), in the situation where this crack is closed prior to kinking but open after it. This problem was recently considered by the authors with the simplifying, but physically quite unrealistic hypothesis of absence of friction between the crack lips. Their work is extended here to account for possible friction governed by Coulomb’s law. Problems of elastic fracture mechanics with unilateral contact and friction between the crack lips being not only non-linear, but incremental in nature, the theoretical treatment becomes notably more involved than without friction. It is still based, however, on the same basic ingredients, namely “homogeneity” properties of the type of problems considered, changes of scale and some reasonable hypotheses. It is shown that whatever the geometry of the body and the crack and whatever the loading, the asymptotic expression of the stress intensity factors (SIF) at the tip of a vanishingly small kinked crack extension depends solely upon the initial (mode II) SIF prior to kinking, the kink angle, Dundurs’s famous parameters α and β and the friction coefficient. The (history-independent) functions involved in the general formulae established are determined numerically through finite element computations. From there, using Goldstein and Salganik’s famous principle of local symmetry to predict the crack path, one derives a theoretical value for the kink angle. This value depends upon the loading only through the sign of the initial stress intensity factor; it also depends on the mismatch of elastic properties and the friction coefficient. However, its range of variation is numerically found to be rather narrow. Experiments conducted by various authors seem to confirm these theoretical predictions.     

The citing practices of the authors to the national journals in mathematics,physics, and chemistry

In this essentially empirical study a comparative analysis of the age of references in scientific papers in three subject fields is performed. Comparisons are made: 1. among national and leading journals in the same scientific field, 2. for a number of high quality journals in physics and chemistry, and 3. between several groups of authors (according to the countries of origin), contributing to the same journals in chemistry. Variations found in the journals citing half-life values suggest that, if properly interpreted, the citing half-life might reflect the journal's quality and might serve as a certain indicator for the citing practices of specific groups of authors.     

Influence of substrate doping on the surface chemistry and morphology of Copper Phthalocyanine ultra thin films on Si (111) substrates

16 nm thick Copper Phthalocyanine (CuPc) films were deposited at room temperature in Ultra High Vacuum onto “n” and “p” type doped Si(111) substrates covered with a native SiO₂ overlayer. Atomic Force Microscopy indicates that the two substrates are both atomically flat (0.15 nm root mean square roughness). Angle dependent X-ray photoemission spectroscopy shows that the thickness of the native SiO₂ over-layer is 0.8 nm (both for the “n” and “p” type Si substrate). Despite the identity of the substrate roughness, of the SiO₂ thickness, and of the CuPc film growth conditions, the organic films (made out of crystallites in the α-phase, as checked with X-ray Diffraction) grown on the “p” and “n” type substrate show clearly different morphological features (determined with Atomic Force Microscopy and Scanning Electron Microscopy measurements). While the CuPc film on “p” Si(111) shows a compact network of densely packed crystallites with sizes (along the substrate plane) ranging from 50 to 100 nm, the CuPc film on “n” Si(111) shows a slightly more open network of larger crystallites (with 75-150 nm size range). Accordingly, the CuPc film roughness is 0.67 nm and 1.15 nm for the “p” and “n” type substrate respectively. Due to the increased surface to volume effects (lower crystallite size) affecting the CuPc film on “p” Si(111), this film exhibits stronger interaction with oxygen and water vapor of the ambient air, as determined by photoemission spectroscopy experiments performed on samples as grown “in situ” and after prolonged (1 year) exposure to air.     

Traffic conflicts and exposure

The concepts “unit of exposure” and “conflict” have proven difficult to tell apart. This paper shows that when conflicts are used to measure safety and exposure is used to estimate risk, the two concepts are diametrically opposed. Conflicts can not be used to measure exposure and vice versa. The last part of the paper is devoted to the elucidation of the concept “exposure”.     

Some observations on thin β-tin films by electron diffraction

Forbidden “110-type” reflections are present on some patterns of tin single-crystal films. Their intensities may vary in a large range and these reflections do not appear with polycrystalline samples. The other forbidden “002-type” reflections which were observed by other authors and ourselves are probably due to secondary elastic scattering, but the kind of “forbidden” spots studied here can be explained by dynamic interactions.     

What you find is not always what you fix—How other aspects than causes of accidents decide recommendations for remedial actions

In accident investigation, the ideal is often to follow the principle “what-you-find-is-what-you-fix”, an ideal reflecting that the investigation should be a rational process of first identifying causes, and then implement remedial actions to fix them. Previous research has however identified cognitive and political biases leading away from this ideal. Somewhat surprisingly, however, the same factors that often are highlighted in modern accident models are not perceived in a recursive manner to reflect how they influence the process of accident investigation in itself. Those factors are more extensive than the cognitive and political biases that are often highlighted in theory. Our purpose in this study was to reveal constraints affecting accident investigation practices that lead the investigation towards or away from the ideal of “what-you-find-is-what-you-fix”. We conducted a qualitative interview study with 22 accident investigators from different domains in Sweden. We found a wide range of factors that led investigations away from the ideal, most which more resembled factors involved in organizational accidents, rather than reflecting flawed thinking. One particular limitation of investigation was that many investigations stop the analysis at the level of “preventable causes”, the level where remedies that were currently practical to implement could be found. This could potentially limit the usefulness of using investigations to get a view on the “big picture” of causes of accidents as a basis for further remedial actions.     

Modeling injury rates as a function of industrialized versus on-site construction techniques

It is often predicted that the industrialization of building activities will lead to a reduction of accident rates in the construction sector, particularly as a result of switching activities from building sites to factories. However, to date no scientific research has provided objective quantitative results to back up this claim. The aim of this paper is to evaluate how industrialization affects the accident rate in different industrialized building systems in Spain. Our results revealed that the industrialized steel modular system presents the lowest accident rate, while the highest accident rate was recorded in the construction method with cast-in-place concrete. The lightweight construction system also presents a high accident rate. Accordingly, industrialized building systems cannot claim to be safer than traditional ones. The different types of “on-site work” seem to be the main variable which would explain the accident rates recorded in industrialized construction systems.     

Induced exposure

Induced exposure “in the narrow sense” refers to exposure to vehicular collision only, and is modelled by a scheme which equates the proportion of single vehicle collisions experienced by a category of driver/vehicles to the proportion of double vehicle collisions in which that driver/vehicle combination was guilty, and which equates the exposure for the category to the proportion not guilty in double vehicle collisions. Induced exposure “in the wide sense” refers to all types of hazard, and separates the data into four categories by a hypothesis that factors relating to an accident are either internal or external for each of the two driver/vehicle combinations involved, where, for single car collisions, one of the “driver/ vehicle” categories is the type of accident, with the restriction that internal factors do not exist in the case where driver/vehicle represents type of single vehicle accident.     

Critical Incident Stress Management (CISM) in complex systems: Cultural adaptation and safety impacts in healthcare

In complex systems, such as hospitals or air traffic control operations, critical incidents (CIs) are unavoidable. These incidents can not only become critical for victims but also for professionals working at the “sharp end” who may have to deal with critical incident stress (CIS) reactions that may be severe and impede emotional, physical, cognitive and social functioning. These CIS reactions may occur not only under exceptional conditions but also during every-day work and become an important safety issue. In contrast to air traffic management (ATM) operations in Europe, which have readily adopted critical incident stress management (CISM), most hospitals have not yet implemented comprehensive peer support programs. This survey was conducted in 2010 at the only European general hospital setting which implemented CISM program since 2004. The aim of the article is to describe possible contribution of CISM in hospital settings framed from the perspective of organizational safety and individual health for healthcare professionals. Findings affirm that daily work related incidents also can become critical for healthcare professionals. Program efficiency appears to be influenced by the professional culture, as well as organizational structure and policies. Overall, findings demonstrate that the adaptation of the CISM program in general hospitals takes time but, once established, it may serve as a mechanism for changing professional culture, thereby permitting the framing of even small incidents or near misses as an opportunity to provide valuable feedback to the system.     

The CNPM thermal heat pump. Part 1 — general description and thermodynamic analysis

A research programme, funded by CNR (National Research Council), has been undertaken by CNPM since 1973. The aim of the programme is the construction and testing of a prototype thermal heat pump. The most significant component is an organic Rankine cycle engine, driving the compressor of a heat pump. Since the heat rejected by the engine is supplied to the user — water for domestic heating — the whole system performs as a ‘heat multiplier’, converting the high temperature heat given to the engine into a larger amount of low temperature heat, to be used for domestic heating.In this paper, the selection criteria for the working fluid — a completely fluoro-substituted hydrocarbon — and the main thermodynamic data of both power and heat pump cycles, are discussed; the finally adopted plant configuration is described, with particular emphasis on the influence exterted by the working fluid nature on the heat exchangers and turbo-machinery dimensions and performance. A discussion on the merits of the single fluid solution (ie the same working fluid in the power and the heat pump cycle) and dual fluid solution is also carried out. The feasibility of a low-temperature heat distribution, based on compact-surface, natural-draft convectors, with the relevant advantages on the Rankine and heat-pump cycles, is also investigated.Finally, the expected overal; system performance is given, both at design and part-load conditions. As a premium for the rather complex but efficient thermodynamicscv of the system, significant energy savings are obtained in all situations.     

The effect of impurities on the melting temperature and the heat of fusion of latent heat storage materials

Thermophysical properties of four normal paraffins (tetradecane, hexadecane, octadecane, eicosane) and three fatty acids (lauric acid, palmitic acid, stearic acid) were determined experimentally using a modified differential-thermoanalysis technique. For calibration of the measuring device, literature data in the temperature range from 5 to 70°C of six of these substances of at least 99% purity were used. Melting temperature, heat of fusion, and specific heat of a number of these pure and technically pure organic compounds were measured and compared to determine the effect of impurities and to give values of the application range of the properties required for the construction of thermal storage equipment.     

A safety assessment methodology applied to CNS/ATM-based air traffic control system

In the last decades, the air traffic system has been changing to adapt itself to new social demands, mainly the safe growth of worldwide traffic capacity. Those changes are ruled by the Communication, Navigation, Surveillance/Air Traffic Management (CNS/ATM) paradigm , based on digital communication technologies (mainly satellites) as a way of improving communication, surveillance, navigation and air traffic management services. However, CNS/ATM poses new challenges and needs, mainly related to the safety assessment process. In face of these new challenges, and considering the main characteristics of the CNS/ATM, a methodology is proposed at this work by combining “absolute” and “relative” safety assessment methods adopted by the International Civil Aviation Organization (ICAO) in ICAO Doc.9689 [14], using Fluid Stochastic Petri Nets (FSPN) as the modeling formalism, and compares the safety metrics estimated from the simulation of both the proposed (in analysis) and the legacy system models. To demonstrate its usefulness, the proposed methodology was applied to the “Automatic Dependent Surveillance-Broadcasting” (ADS-B) based air traffic control system. As conclusions, the proposed methodology assured to assess CNS/ATM system safety properties, in which FSPN formalism provides important modeling capabilities, and discrete event simulation allowing the estimation of the desired safety metric.     

Factors influencing worker use of personal protective eyewear

Objective

To identify and describe the array of factors that influence a workers’ decision to wear personal protective eyewear (PPE) and the barriers that exist in preventing their use.

Design, setting and participants

A series of focus groups enrolled workers and supervisors primarily from manufacturing, construction, or service/retail industries that had potential exposure to eye injury hazards in their job tasks. Focus group sessions were facilitated to collect qualitative and quantitative data in two categories, “sought information” and “emergent themes”, related to the factors influencing use of PPE.

Results

We conducted a series of 7 groups with 51 participants, 36 (71%) males and 15 (29%) females ranging in age from 19 to 64 years old, from a variety of occupations including construction (24%), production (22%), installation, repair and maintenance (14%), and healthcare (10%). Most were highly experienced in their occupation (>10 years); males (86%) and females (53%), and had received some safety training in the past (82%). The majority of workers in this study were required to wear PPE on their worksite (78%), however only 55% had a dedicated safety officer. A conceptual model that summarizes the “sought information” and “emergent themes” is presented that depicts the decision making process for the factors influencing use of PPE and consists of three primary branches; perceptions of hazards and risks, “barriers” to PPE usage, and enforcement and reinforcement. Lack of comfort/fit, and fogging and scratching of the eyewear were suggested as the most important barriers to PPE usage. Younger age and lack of safety training were other important factors affecting use of PPE.

Conclusions

Several potentially modifiable factors identified would lead to an increase in workers’ PPE use and encourage supervisors to provide ongoing positive feedback on the continuous use of PPE by workers at risk for an eye injury.