The impact of work input to sorption cyclesImpact de l'apport en énergie sur les cycles à sorption

In recent years the interest in cooling machines or heat pumps combining the principles of compression and sorption technology is increasing. The reason is that both technologies have specific drawbacks which can be overcome by the combination. Our discussion is centred around absorption cycles which use a compressor, and, consequently, an input of a significant amount of mechanical work in addition to heat. In most publications cycles of this kind are discussed in terms of one single COP as usual in the refrigeration industry. This, however, is wrong from a thermodynamic, and misleading from a technical and economical point of view. In order to highlight the need for a strict thermodynamic approach, a fundamental difference between distinct kinds of work input, namely “recoverable work”, “dissipative work” and “heat transformation work” is discussed in the first part of the paper. In the second part it is shown how the input of both work and heat into a energy conversion system has to be handled with both mechanical and thermal COP. The method is thermodynamically sound and straightforward, technically feasible and easy to apply, and most quickly transferred into economical terms. In the third part, a practical example of a compression–absorption hybrid is investigated.     

Isolation of an RNA-directed RNA polymerase-specific cDNA clone from tomato

A 3600-bp RNA-directed RNA polymerase (RdRP)-specific cDNA comprising an open reading frame (ORF) of 1114 amino acids was isolated from tomato. The putative protein encoded by this ORF does not share homology with any characterized proteins. Antibodies that were raised against synthetic peptides whose sequences have been deduced from the ORF were shown to specifically detect the 127-kD tomato RdRP protein. The immunoresponse to the antibodies correlated with the enzymatic activity profile of the RdRP after chromatography on Q-, poly(A)-, and poly(U)-Sepharose, hydroxyapatite, and Sephadex G-200 columns. DNA gel blot analysis revealed a single copy of the RdRP gene in tomato. RdRP homologs from petunia, Arabidopsis, tobacco, and wheat were identified by using polymerase chain reaction. A sequence comparison indicated that sequences homologous to RdRP are also present in the yeast Schizosaccharomyces pombe and in the nematode Caenorhabditis elegans. The previously described induction of RdRP activity upon viroid infection is shown to be correlated with an increased steady state level of the corresponding mRNA. The possible involvement of this heretofore functionally elusive plant RNA polymerase in homology-dependent gene silencing is discussed.     

Multiperiod forecasting in stock markets: a paradox solved

One of the most striking results on asset pricing in the last 20 years is the better forecastability of long-horizon returns over one-step return forecasts. This could seem a paradox, given that the further our forecast horizon the greater the uncertainty we are bound to face. This point can be found in Campbell and Shiller [Journal of Finance 43 (1988) 661; Journal of Finance 40 (1985) 793; American Economic Review 76 (1986) 1142] among others. In this paper, we offer an alternative explanation to this “forecast paradox ” that is in agreement with Kim et al. [Review of Economic Studies 30 (1992) 25], who found that the negative serial correlation in long-horizon returns depends very much on the sample choice. Our explanation is based on the existence of simultaneous shifts in the time series of the equilibrium stock price and dividends. This explanation relies on the concept of co-breaking [D.F. Hendry, A theory of co-breaking, Mimeo, Nuffield College, Oxford, 1995.]. We put forward a stochastic present value model, in which we are able to show how shifts in the process for dividends lead to shifts in the equilibrium stock price.This has important implications for multiperiod forecasting, as we demonstrate in this paper. An empirical application supports our results. In our empirical application, we model earning, dividends, stock prices, and the risk-free interest in the United States from 1926 to 1985. We can distinguish three different historical periods where the process for dividends and the equilibrium stock prices are characterized by different properties in terms of their means and variances. Our empirical model is extended to a forecasting exercise where the “forecast paradox” is solved.     

Personality test correlates of psychiatric outpatient status.

Frequencies of stanine scores for 10 Comrey Personality Scales (CPS) were compared separately by sex for 394 psychiatric outpatients (mean age 31 yrs) and 748 normals from the original CPS normative group (A. L. Comrey, 1970). In both sexes, outpatients had significantly more high scores on Response Bias, Orderliness vs Lack of Compulsion, and Social Conformity vs Rebelliousness and more low scores on Activity vs Lack of Energy, Emotional Stability vs Neuroticism, and Extraversion vs Introversion. Female outpatients also had more low scores on Trust vs Defensiveness and male outpatients had more low scores on Masculinity vs Femininity. Outpatients had more extreme scores over all CPS scales than normals. It is concluded that tests of normal personality traits have considerable potential utility for screening, diagnosis, and design of clinical interventions. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Estimation of the virtual workpiece quality by the use of a spindle-integrated process force measurement

Existing workpiece quality estimations utilize material removal simulations in combination with dynamic force measurements. The common force measurement method, using plate dynamometer, is not practicable due to space-constrains, high costs and inertial forces in case of 5-axis machining that falsify the measurement considerably. This paper examines the potential of workpiece quality monitoring by the use of a spindle-integrated high-resolution force measurement that uses displacement sensors. Considering the experimentally determined transfer-function between the force at the TCP and the displacement sensor, it is possible to calculate cutting forces during machining. The virtual quality is compared with CMM measurements.     

Thermodynamics of desulphurization reactions during the treatment of hot metal with calcium and calcium compounds

Basic discussions on the desulphurization reactions when treating hot metal with calcium and calcium compounds shall contribute to a better understanding of the results of this process where mixtures of lime and calcium carbide are added by means of the submerged lance process. From the thermodynamic equilibrium of sulphur and oxygen with calcium carbide it can be concluded that in commercial-scale operation with a submerged lance the use of pulverized calcium carbide leads to a considerable conversion of calcium carbide into calcium oxide due to the dissolution of the oxygen contained in the hot metal. The desulphurization reaction is predominantly a secondary reaction with the calcium oxide which is turned into calcium sulfide. Additions of aluminium into the hot metal rush the lime desulphurization reaction by decreasing the oxygen activity in the hot metal and by suppressing the passive dicalciumsilicate formation on the lime surface by formation of calcium aluminate during the desulphurization reaction.     

An advanced diffusion model to identify emergent research issues: the case of optoelectronic devices

Scientific progress in technology oriented research fields is made by incremental or fundamental inventions concerning natural science effects, materials, methods, tools and applications. Therefore our approach focuses on research activities of such technological elements on the basis of keywords in published articles. In this paper we show how emerging topics in the field of optoelectronic devices based on scientific literature data from the PASCAL-database can be identified. We use Results from PROMTECH project, whose principal objective was to produce a methodology allowing the identification of promising emerging technologies. In this project, the study of the intersection of Applied Sciences as well as Life (Biological &; Medical) Sciences domains and Physics with bibliometric methods produced 45 candidate technological fields and the validation by expert panels led to a final selection of 10 most promising ones. These 45 technologies were used as reference fields. In order to detect the emerging research, we combine two methodological approaches. The first one introduces a new modelling of field terminology evolution based on bibliometric indicators: the diffusion model and the second one is a diachronic cluster analysis. With the diffusion model we identified single keywords that represent a high dynamic of the mentioned technology elements. The cluster analysis was used to recombine articles, where the identified keywords were used to technological topics in the field of optoelectronic devices. This methodology allows us to answer the following questions: Which technological aspects within our considered field can be detected? Which of them are already established and which of them are new? How are the topics linked to each other?