921 research outputs found
Gas chromatograph injection port protective device
To prevent samples containing foreign matter from poisoning the gas chromatographic columns, a pre-filter insertion is placed in the injection port. The packing becomes a variable reactant, for example, acids are removed by using an alkaline liquid
Cash use of the Taiwan dollar: Is it efficient?
Two banknotes and two coins of the New Taiwan Dollar are infrequently (if at all) used
in Taiwan when people make cash payments. This note examines the effect of this behavior on the
efficiency of cash payments. The results are compared with the Euro, where the two highest and two
lowest tokens are also rarely used. We find for Taiwan that inefficiency increases with 60.7%, while
for the Euro it is only 25.3%. The main reason is that two of the rarely used coins and notes in Taiwan
are in the middle of the denominational range, whereas for the Euro, these tokens concern the ends
of that range
Cash use of the Taiwan dollar: Is it efficient?
Two banknotes and two coins of the New Taiwan Dollar are infrequently (if at all) used
in Taiwan when people make cash payments. This note examines the effect of this behavior on the
efficiency of cash payments. The results are compared with the Euro, where the two highest and two
lowest tokens are also rarely used. We find for Taiwan that inefficiency increases with 60.7%, while
for the Euro it is only 25.3%. The main reason is that two of the rarely used coins and notes in Taiwan
are in the middle of the denominational range, whereas for the Euro, these tokens concern the ends
of that range
Cash use of the Taiwan dollar: Is it efficient?
Two banknotes and two coins of the New Taiwan Dollar are infrequently (if at all) used
in Taiwan when people make cash payments. This note examines the effect of this behavior on the
efficiency of cash payments. The results are compared with the Euro, where the two highest and two
lowest tokens are also rarely used. We find for Taiwan that inefficiency increases with 60.7%, while
for the Euro it is only 25.3%. The main reason is that two of the rarely used coins and notes in Taiwan
are in the middle of the denominational range, whereas for the Euro, these tokens concern the ends
of that range
Does More Expert Adjustment Associate with Less Accurate Professional Forecasts?
Professional forecasters can rely on an econometric model to create their forecasts. It is
usually unknown to what extent they adjust an econometric modelâbased forecast. In this paper we
show, while making just two simple assumptions, that it is possible to estimate the persistence and
variance of the deviation of their forecasts from forecasts from an econometric model. A key feature
of the data that facilitates our estimates is that we have forecast updates for the same forecast target.
An illustration to consensus forecasters who give forecasts for GDP growth, inflation and
unemployment for a range of countries and years suggests that the more a forecaster deviates from
a prediction from an econometric model, the less accurate are the forecasts
Does More Expert Adjustment Associate with Less Accurate Professional Forecasts?
Professional forecasters can rely on an econometric model to create their forecasts. It is
usually unknown to what extent they adjust an econometric modelâbased forecast. In this paper we
show, while making just two simple assumptions, that it is possible to estimate the persistence and
variance of the deviation of their forecasts from forecasts from an econometric model. A key feature
of the data that facilitates our estimates is that we have forecast updates for the same forecast target.
An illustration to consensus forecasters who give forecasts for GDP growth, inflation and
unemployment for a range of countries and years suggests that the more a forecaster deviates from
a prediction from an econometric model, the less accurate are the forecasts
Filament identification and dominance of Eikelboom Type 0092 in activated sludge from wastewater treatment facilities in Cape Town, South Africa
Routine characterisation of activated sludge and identification of the filamentous population by microscopic and/or other non-culture dependent techniques can assist in diagnosing the aetiology of poor performance of wastewater treatment works (WWTWs). In South Africa, most facilities rely solely on physicochemical indicators, treating reactors as âblack-boxesâ, with the result that process adjustments are often delayed, to the detriment of the environment. This study was performed in order to gain insight into the filamentous population found in activated sludge in Cape Town WWTWs, to compare these with other global and local literature findings, and to build capacity in this science. Physicochemical and plant performance parameters, in terms of nutrient removal and settling, were obtained from routine operational data and assessed in conjunction with the microscopic analyses of activated sludge samples taken over a 6-month period. Hypotheses on the links between filament types and/or plant configurations and/or operational parameters were formulated using existing literature. In order of prevalence, the five most common dominant filament species in 96 activated sludge samples were: Eikelboom Type 0092, Eikelboom Type 1851, nocardioforms, Microthrix parvicella and Eikelboom Type 021N. In order to compile a statistically significant database, it is recommended that an extensive nationwide study is conducted to link filament types with plant configurations, operational parameters and geographical locations.Keywords: activated sludge, bulking, identification, filament, Type 009
Structure determination of the clean Co(110) surface by LEED
The atomic structure of the (11 0) surface of cobalt has been determined by LEED using six intensity spectra at normal incidence. The surface exhibits the truncated bulk structure with a contraction of the first interlayer spacing by about 8.5% with respect to the bulk value. Quantitative evaluation of the LEED spectra was done using Zanazzi and Jona's and Pendry's r-factors. The minimum averaged r-factors are and . No change of the interatomic distances within the plane could be detected and no rearrangement of the surface structure takes place up to temperatures shortly below the transition temperature
Description of an ancient social bee trapped in amber using diagnostic radioentomology
The application of non-invasive imaging technologies using X-radiation (diagnostic radioentomology, âDR') is demonstrated for the study of amber-entombed social bees. Here, we examine the external and internal morphology of an Early Miocene (Burdigalian) stingless bee (Apinae: Meliponini) from the Dominican Republic using non-destructive X-ray microtomography analysis. The study permits the accurate reconstruction of features otherwise obscured or impossible to visualize without destroying the sample and allows diagnosis of the specimen as a new species, Proplebeia adbita Greco and Enge
Two-photon interference with true thermal light
Two-photon interference and "ghost" imaging with entangled light have
attracted much attention since the last century because of the novel features
such as non-locality and sub-wavelength effect. Recently, it has been found
that pseudo-thermal light can mimic certain effects of entangled light. We
report here the first observation of two-photon interference with true thermal
light.Comment: 4 pages, 5 figures, PRA72, 043805 (2005
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