Which emission sources are responsible for the volatile organic compounds in the atmosphere of Pearl River Delta?

A field measurement study of volatile organic compounds (VOCs) was simultaneously carried out in October-December 2007 at an inland Pearl River Delta (PRD) site and a Hong Kong urban site. A receptor model i.e. positive matrix factorization (PMF) was applied to the data for the apportionment of pollution sources in the region. Five and six sources were identified in Hong Kong and the inland PRD region, respectively. The major sources identified in the region were vehicular emissions, solvent use and biomass burning, whereas extra sources found in inland PRD included liquefied petroleum gas and gasoline evaporation. In Hong Kong, the vehicular emissions made the most significant contribution to ambient VOCs (48 ± 4%), followed by solvent use (43 ± 2%) and biomass burning (9 ± 2%). In inland PRD, the largest contributor to ambient VOCs was solvent use (46 ± 1%), and vehicular emissions contributed 26 ± 1% to ambient VOCs. The percentage contribution of vehicular emission in Hong Kong in 2007 is close to that obtained in 2001-2003, whereas in inland PRD the contribution of solvent use to ambient VOCs in 2007 was at the upper range of the results obtained in previous studies and twice the 2006 PRD emission inventory. The findings advance our knowledge of ozone precursors in the PRD region.     

Which role do non-source items play in the social sciences? A case study in political science in Germany

Publications that are not indexed by citation indices such as Web of Science (WoS) or Scopus are called “non-source items”. These have so far been neglected by most bibliometric analyses. The central issue of this study is to investigate the characteristics of non-source items and the effect of their inclusion in bibliometric evaluations in the social sciences, specifically German political science publications. The results of this study show that non-source items significantly increase the number of publications (+1,350 %) and to a lesser extent the number of citations from SCIE, SSCI, and A&HCI (+150 %) for evaluated political scientists. 42 % of non-source items are published as book chapters. Edited books and books are cited the most among non-source items. About 40 % of non-source items are in English, while 80 % of source items are in English. The citation rates of researchers taking non-source items into account are lower than those from source items, partially as a result of the limited coverage of WoS. In contrast, the H-indices of researchers taking only non-source items into account are higher than those from source items. In short, the results of this study show that non-source items should be included in bibliometric evaluations, regardless of their impact or the citations from them. The demand for a more comprehensive coverage of bibliometric database in the social sciences for a higher quality of evaluations is shown.     

Experimental proof of a chromatographic paradox: are the injected molecules in the peak?

Forty years ago Helfferich and Peterson published an article in Science regarding a "paradoxical" behavior in nonlinear chromatography (Helfferich, F.; Peterson, D. L. Science 1963, 142, 661-662). They theoretically predicted that when an excess of sample molecules is injected into a chromatographic column that is equilibrated with a constant stream of identical molecules, the observed peak will not contain the injected molecules. Instead the observed peak will only contain molecules from the stream whereas the injected molecules will exit the column in a slower moving, "invisible" peak. They considered it paradoxical that a single injection in a single-component system could cause the successive elution of two peaks (Helfferich, F. J. Chem. Educ. 1964, 41, 410-413). In this study, the paradox is experimentally proven for the first time. Two different strategies were employed: (i) a radiochemical approach and (ii) a method based on the use of two enantiomers in a nonchiral separation system. The experiments were compared with computer simulations.     

The protective efficacy of surgical latex gloves against the risk of skin contamination: how well are the operators protected?

Latex gloves are used by surgical staff to avoid exposure to patient body fluids, thus reducing the risk of contracting bloodborne viral diseases, such as hepatitis C and HIV. We studied the efficacy of the surgical barrier provided by latex gloves, before and after use in the operating theater. The electrical conductivity, insulation and mechanical resistance of glove latex were investigated, using routine supplies of surgical gloves. Latex structure was assessed by scanning electron microscopy and by mercury intrusion porosimetry. Latex is subject to hydration, a phenomenon associated in the laboratory with the loss of its electrical insulation properties. Such glove latex properties were found to be highly variable, with latex hydration times varying between 2 and more than 30 min. Rapidly hydrating gloves showed increased permeability to methylene blue, associated with higher levels of porosity. Thirty min of surgical use was associated with measurable hydration of glove latex and a statistically significant loss of electrical and mechanical resistance, with rupture load decreasing by 24%. Electronic control of the insulation properties of gloves during surgery permits early detection of hydration, and allows prompt correction by glove change, before the gloves lose their electrical and mechanical competence.     

Does faculty disciplinary background play a role in the publication pattern of an interdisciplinary research area? The case of science education in Brazil

Scientometrics - Research in the Social Sciences and Humanities is published in a variety of formats and types of documents. Local journals are relevant for these fields, particularly in...     

Localization and Registration of Three-Dimensional Objects in Space-Where are the Limits?

We discuss the accuracy limits for the localization of surfaces in three-dimensional (3-D) space. Such a localization is necessary for the registration of different views of an object, taken by 3-D sensors from several directions. A quantitative analysis shows that the lateral localization accuracy of a small surface area is proportional to the local curvature of the surface. This confirms the intuitive conjecture that our visual system performs localization of 3-D objects via sharp features. The longitudinal localization accuracy depends only on the noise of the data and is usually much better than the lateral localization accuracy, suggesting that surfaces are to be registered only along the longitudinal directions.     

Is the United States losing ground in science? A global perspective on the world science system

Based on the Science Citation Index-Expanded web-version, the USA is still by far the strongest nation in terms of scientific performance. Its relative decline in percentage share of publications is largely due to the emergence of China and other Asian nations. In 2006, China has become the second largest nation in terms of the number of publications within this database. In terms of citations, the competitive advantage of the American “domestic market” is diminished, while the European Union (EU) is profiting more from the enlargement of the database over time than the USA. However, the USA is still outperforming all other countries in terms of highly cited papers and citation/publication ratios, and it is more successful than the EU in coordinating its research efforts in strategic priority areas like nanotechnology. In this field, the People’s Republic of China (PRC) has become second largest nation in both numbers of papers published and citations behind the USA.     

Patent research in the field of library and information science: Less useful or difficult to explore?

Patents and relevant topics are gaining momentum in economic analysis and scientific research with the rapid global intellectual property filings growth. However, a corresponding increase seems to be unspectacular in patent research publications, especially under the category of information science and library science. This paper provided a retrospect to the existing studies on patents collected from web of science and emphatically characterized the current situation through performing a series of bibliometric analysis. Prominent authors and institutions from mainland China, Taiwan and Belgium have carried out various studies on patent separately or jointly. Topics involved in 884 journal papers are reclassified from perspectives of the development, application and analysis of patents based on the results of keyword co-occurrence and typical publications in each stage. The final, but the novel part of this study was a sentence-by-sentence analysis of conclusive and citing ideas of recent publications, for tracing problems and potential researchable topics and indicating that patent research still has more spaces to move up.     

Which are the relevant costs and benefits of road safety measures designed for pedestrians and cyclists?

This paper discusses the current state-of-the-art with respect to impact assessment and cost-benefit analysis of measures designed to improve safety or mobility for pedestrians and cyclists. The study concludes that a number of impacts that are likely to regarded as important for pedestrians and cyclists are not included in current impact assessments and cost-benefit analyses as these are made in Norway. Impacts that are not currently included in impact assessments and cost-benefit analyses are: (a) changes in the amount of walking and cycling; (b) changes in travel time for pedestrians and cyclists; (c) changes in road user insecurity (feeling of safety); and (d) changes in road user health state. In order to include these effects in impact assessments and cost-benefit analyses, more needs to be known about their occurrence and monetary value. Hypothetical examples of ideally designed cost-benefit analyses are given, based on highly preliminary monetary values for travel time, insecurity and generalised costs of travel for pedestrians and cyclists. These analyses indicate that inclusion of these effects in cost-benefit analyses could make a major difference for the results of those analyses.     

Uncertainty in macroeconomic policy-making: art or science?

Uncertainty is pervasive in economic policy-making. Modern economies share similarities with other complex systems in their unpredictability. But economic systems also differ from those in the natural sciences because outcomes are affected by the state of beliefs of the systems' participants. The dynamics of beliefs and how they interact with economic outcomes can be rich and unpredictable. This paper relates these ideas to the recent crisis, which has reminded us that we need a financial system that is resilient in the face of the unpredictable and extreme. It also highlights how such uncertainty puts a premium on sound communication strategies by policy-makers. This creates challenges in informing others about the uncertainties in the economy, and how policy is set in the face of those uncertainties. We show how the Bank of England tries to deal with some of these challenges in its communications about monetary policy.     

Making the most of world talent for science? The Nobel Prize and Fields Medal experience

Scientometrics - Opportunities in science largely affect the accumulation of scientific knowledge and, therefore, technological change. However, there is little evidence of how much of...     

The peak in the thermal conductivity of Cu-O superconductors: Electronic or phononic origin?

The thermal conductivity of hole-doped Cu-O plane high-T _c perovskites exhibits a dramatic increase belowT _c which results in a pronounced peak nearT _c /2. The origin of this peak was initially thought to arise from an enhancement in the mean-free path of phonons as the charge carriers undergo condensation. Indeed, excellent fits to the data can be obtained with physically reasonable parameters using the conventional theory of lattice conduction in superconductors. In contrast, a recently observed sharp decrease in the quasiparticle scattering rate of YBCO single crystals belowT _c has motivated proposals for an electronic origin of the thermal conductivity peak. We shall critically examine experimental evidence and highlight relative advantages and shortcomings of the two contrasting interpretations. Furthermore, we shall draw attention to recently available data on the relaxation time of out-of-equilibrium carriers in Cu-O superconductors obtained using pump-probe femtosecond laser studies and what new light they shed on the controversy.     

Which h-index? An exploration within the Web of Science

Scientometrics - The h-index has attracted wide attention from both scientometricians and science policy makers since it was proposed in 2005. Advocates champion h-index for its simplicity...     

Influence of the international collaboration in the field of metric studies of science and technology: the case of Mexico (1971–2018)

Scientometrics - We perform a bibliometric analysis of the research production and impact of Mexican scholars involved in the area of metric studies of science and technology in the period...