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.     

Theory of freezing: The inhomogeneous Ornstein-Zernike equation

We present a new freezing theory based on the inhomogeneous Ornstein-Zernike equation. The new theory is nonperturbative, in the sense that crystal and liquid are treated at the same level of approximation. This is in contrast to the popular density functional theory of freezing, which uses the liquid as a reference state for perturbation theory. Due to the demanding nature of the numerical method, preliminary calculations are presented for a model problem — which, in the strictest sense, is unphysical — namely, the freezing of hard disks in two dimensions. We also explore a generalized Percus-Yevick closure appropriate for the crystal.Paper presented at the Tenth Symposium on Thermophysical Properties, June 20–23, 1988, Gaithersburg, Maryland, U.S.A.     

Generalizing BCS for Exotic Superconductors

A new boson–fermion statistical model with two-hole (h) as well as two-electron (e) Cooper pairs (CP) exhibiting Bose–Einstein condensation (BEC)—which simultaneously reduces to BCS theory in weak coupling for perfect eh symmetry and to BEC when no hole CPs are present—yields reasonable transition temperatures for exotic superconductors, whether quasi-2D cuprate or 3D ones, for moderate departures from perfect eh symmetry.     

Representing cognitive activities and errors in HRA trees

A graphic representation method is presented herein for adapting an existing technology—human reliability analysis (HRA) event trees, used to support event sequence logic structures and calculations—to include a representation of the underlying cognitive activity and corresponding errors associated with human performance. The analyst is presented with three potential means of representing human activity: the NUREG/CR-1278 HRA event-tree approach; the skill-, rule- and knowledge-based paradigm; and the slips, lapses, and mistakes paradigm. The above approaches for representing human activity are integrated in order to produce an enriched HRA event tree—the cognitive event tree system (COGENT)—which, in turn, can be used to increase the analyst's understanding of the basic behavioral mechanisms underlying human error and the representation of that error in probabilistic risk assessment. Issues pertaining to the implementation of COGENT are also discussed.     

On the characteristics of extreme values for series systems

This paper investigates the characteristics of extreme events for series systems. A methodology is developed to determine the Gumbel Type of a series system, given that the Gumbel Types of the components are known. Determining the propagation of the Gumbel Types can be accomplished without knowing the exact probability density functions of the components and without calculating the analytic form for the distribution of the overall system. In addition, an analytical technique is developed to determine the parameters of the extreme value distribution—the characteristic largest value, and the inverse measure of dispersion—for the overall series system. Finally, these three pieces of information—the Gumbel Type, the characteristic largest value, and the inverse measure of dispersion—are combined to calculate a conditional expected value of extreme events of the overall series system.     

Automotive reliability inference based on past data and technical knowledge

The constantly increasing market requirements of high quality vehicles ask for the automotive manufacturers to carry out—before starting mass production—reliability demonstration tests on new products. However, due to cost and time limitation, a small number of copies of the new product are available for testing, so that, when the classical approach is used, a very low level of confidence in reliability estimation results in. In this paper, a Bayes procedure is proposed for making inference on the reliability of a new upgraded version of a mechanical component, by using both failure data relative to a previous version of the component and prior information on the effectiveness of design modifications introduced in the new version. The proposed procedure is then applied to a case study and its feasibility in supporting reliability estimation is illustrated.     

Stress singularity in a substrate-coating system

A problem of the theory of elasticity is solved for a substrate—coating system with the coating free edge of various configurations. A biharmonic equation of the theory of elasticity in the polar coordinates is considered, for the solution of which the Airy function is proposed to be used. The dependences of the singularity on the ratio of the elastic characteristics of the substrate—coating system and on the configuration of the coating free edge have been obtained. The order of the stress singularity has been found for plasma-sprayed coatings. In particular cases, the problem has been shown to degenerate into the fracture mechanics problem on a crack in a homogeneous material or into the problem of the theory of elasticity for homogeneous wedges and notches.Translated from Problemy Prochnosti, No. 6, pp. 119–127, November–December, 2004     

On Theory of the Phase Transitions in Solid Hydrogen under Pressure. Reentrant Behavior and Critical Points

Temperature dependences of the order parameter and the phase transition lines are calculated for the broken symmetry phase transition for a system of even—J, all—J and odd—J quantum rotors. Effect of positive and negative crystal fields is calculated and shown that these fields may turned out to be an important factor previously omitted in theory, which is responsible for a gap between theory and experiment.     

Microprocessor measurement information system for estimating parameters of motion

A microprocessor system for estimating parameters of motion — acceleration and increments of velocity and distance — by means of a KM 1813VE1 digital signal processor is investigated. Analytical expressions are derived for the admissible processing time of the system in real-time measurements.Translated from Izmeritel'naya Tekhnika, No. 12, pp. 18–20, December, 1994.     

A new digital correlation flaw detection system

A new portable digital random signal flaw detection system is described which uses a digital delay line to replace the acoustic delay line of the original random signal system. Using this new system, a comparison was made between the two types of transmit signals which have been used in previous systems—m-sequences and random signals. This comparison has not been possible with these previous correlation flaw detection systems. Results indicated that for high-speed short code operation, the m-sequences produced slightly lower range sidelobes than typical samples of a clipped random signal. For normal long code operation, results indicated that system performance is essentially equivalent in resolution and signal-to-noise ratio using either m-sequences or clipped and sampled random signals. Further results also showed that for normal long code operation, the system produces outputs equivalent in resolution to pulse-echo systems, but with the added benefit of signal-to-noise ratio enhancement.     

The hydrogen economy, fuel cells, and electric cars

Hopes have again been raised about developing a “hydrogen economy”, in which hydrogen could be expected to replace oil and natural gas for most uses, including transportation and heating. It is again being claimed that hydrogen will be a widely available, clean, safe fuel. This article argues that such expectations are almost certainly illusory. Hydrogen, like electricity, is not an energy resource but an energy carrier. It takes more energy to extract hydrogen from water than burning the hydrogen can ever provide. There are also inevitable losses in storage, transmission, and final mechanical or heating applications. The question then turns on the efficiency—and safety—of the entire chain of conversion, from the energy source (fossil, solar, or other) to the final use. Moreover, energy sources (preferably renewable, for the long term) can be used for the direct creation of electricity, which can be introduced into the existing grid without requiring a vast investment in a new hydrogen distribution system. In addition, a hydrogen-based system would be unacceptably dangerous. This report will present a detailed technical and economic analysis of the problems with the proposed hydrogen economy and the advantages of some alternatives, principally electricity-based. A hypothetical case of what would be required for a hydrogen filling station serving the general public is closely examined.     

Mincut-based fault tree analysis revisited and extended for calculating MTBF

It is shown that, with the mincuts given, the Shannon approach is strongly challenged by an approach resulting in subproduct inversions, based on a simple partitioning of the system faults. A simple heuristic is given for an almost optimal determination of i) system unavailability ii)—after a little addendum—system mean failure frequency; the latter for s-independent repairable components. In order to speed up calculations, optimal approximations with prescribed accuracy are possible, both for unavailability and mean failure frequency.     

Possible causes of differences in information impact of journals from different subfields

Differences in size, mean number of references per paper in journals, ageing of information and disciplinarity of some subfields in chemistry were studied in order to explain different average impact factors for journals. A new indicator —Standard Journal Impact — is suggested, which may be used as a standardized (i.e. comparable) impact indicator for journals in different subfields. The main reason for the lower impact factor for journals of the macromolecular chemistry subfield may be the lower extent of the application of their results by other subfields.Dedicated to the memory of Michael J. Moravcsik     

Importance of the quality management of safety analysis

Although safety analysis is now being put to increased usage, it is often criticized for the quality of the analyses and for the resources needed. Quality systems devised for other industrial purposes offer means for developing methods and criteria to support the quality management of safety analyses.This study evaluated the quality of four safety analyses from the perspective of operational experience, using a new method developed to assess the quality of safety analysis. The study identified some problems that are typical of safety analysis processes and some factors which decrease the quality of analyses. This paper discusses quality assessment, quality management, and means for improving the quality of safety analyses. A new method, called QUASA—for Quality Assessment of Safety Analysis—is described and its applicability to quality management of safety analysis is evaluated.     

The technology assessment and forecast program of the United States patent and trademark office

Often overlooked is the wealth of information in patents that makes patents useful to public policy making agencies and corporate management, among others. The source of this information is the bibliographic and classification data associated with each patent. much of which is required by law and hence is extremely accurate. These data serve to fingerprint the increment of technological activity disclosed in a patent. Possible ways of using the data include: — identification of emerging technologies — Monotoring foreign activity — identification of “actors” in the technology — tracking applications and impacts of a technologyThe objective of the technology assessment and forecast program of the United States Patent and Trademark Office is to stimulate the use of the patent file of the Office. The Office of Technology Assessment and Forecast (OTAF), which administers the program has assembled a master data base covering all U.S. patents. It periodically updates this base and adds new data items to it.     

New trends in power system planning and related effect on the reliability evaluation

ENEL, a vertically integrated utility for generation, transmission and distribution in Italy, has been a worldwide leader since the 1970s in setting up ‘home made’ computing programs for the adequacy evaluation, imbedded in the majority of studies needed in power system planning and operation, of large composite generation and transmission systems.Adequacy evaluation has a probabilistic content. Two complementary approaches have been adopted at ENEL, direct probabilistic approach and Monte Carlo simulation, implementing a number of computing programs tailored to the Italian situation. Naturally, those approaches have been complemented by deterministic evaluations, with the well-known computer programs used in power system planning and operation.The recent changes in the electric supply industry, ‘liberalized’ and privatized at different extent in the various countries, emphasized the importance of the reliability evaluation as a key issue for the establishment of revised/updated adequacy/security standards aiming to the proper allocations of the investments. In Italy the major ‘new’ issues are presently the effect/compatibility of the non-utility generators with ENEL mixed hydrothermal generation system and the increasing ‘size’ of the transmission network, evermore interconnected with other foreign systems, which ask for suitable ‘adequacy-orientated’ equivalents and ‘new’ tools for the evaluation of concept such as ‘transmission duty pricing’.The paper describes how at ENEL the new trends are faced and the work which ENEL, now a joint stock company which—in addition to the obligation to supply—has new responsibilities against the potential stockholders, has under way in the field of adequacy assessment.     

Important issues using PSA technology for design of new systems and plants

Modern engineering design of new systems or plants needs not only the specification of the function of the system during various life cycle periods, but also the consideration of additional requirements and the demonstration of the compliance with it based on a predictive model considering measurable properties and possible malfunctions of the system parts. Additional requirements can be high availability, low emissions or high safety level. PSA technology provides a framework and tools to establish design targets and to demonstrate their compliance. In this paper important issues using this technology are discussed. Issues are targeted at various levels—the basic evaluation of reliability for active and passive components and the entire system, the general process to show the compliance of the given system characteristics with the characteristics required. This paper does not deal with the details of all these issues, but provides references for further information.     

In search of design excellence

This paper is based on part of the results of an extensive survey of the role of new product design in international competitiveness. It reviews the literature on design management and highlights some weaknesses in the way in which design is managed in many UK industries, which apparently places the UK at a competitive disadvantage in manufacturing exports when compared with their major foreign competitors. The paper examines ways in which the management of design many be enhanced to improve design quality and achieve greater competitiveness. It was found that to maximize achievements in design, innovators must not only create awareness, but also create a climate in which everyone is committed to design quality throughout the organization. A wide range of functions involved in design management — managerial, marketing, technical, financial, etc. — must also be ‘happily married’ to achieve product excellence and hence market success.     

Characterization of cerium and copper species in Cu—Ce—Al oxide systems by temperature programmed reduction and electron paramagnetic resonance

The reducibility of Ce—Al—O and Cu—Ce—Al—O solids is studied by H₂-TPR and EPR in order to identify the different ceria and copper oxide species. The study of Ce—Al—O oxides shows that dispersion of ceria on alumina improves reducibility of ceria bulk and stabilizes surface ceria. Concerning quantitative results, ceria reduction extent is more important for Ce—Al—O oxides than for pure ceria. This result can be related to the dispersion of ceria on alumina which decreases ceria crystallites size and enhances the ceria bulk reduction. For ternary oxides, copper oxide and ceria interact strongly. Introduction of copper facilitated ceria reduction, and quantitatively, the presence of copper favors the total reduction of ceria contrary to Ce—Al—O oxides. When ceria loading is low, two copper species are identified, and are attributed to small clusters and highly dispersed copper oxides. During the reduction of copper species, a partial reduction of ceria is observed. Increasing of copper loading leads to the formation of CuO aggregates.     

Openness index and affinity index: Two new citation indicators

This article discusses some design issues in the self-citing rate and the self-cited rate proposed by the Social Sciences Citation Index for journals. Improvements on the above measures lead to two new citation indicators—the Openness Index and the Affinity Index. These new indices could be expressed in terms of several components (self, own-field, other-field, overall). Each of these components indicates more specific citation situations of a journal. The application of these new citation indicators is illustrated in the measurement of some journal's characteristics in the field of communication.