bluuebunny/crossref_metadata_2025 huggingface dataset:
Towards the carbon fibers in the building industry
Authors: Miravete A.
Published: July 2010

There are two mainstreams in the building industry in the area of carbon fibers: rehabilitation and use as building material. The using of carbon fiber as a building material is taking place slower than as rehab system due to the very low cost of traditional building materials, the limitations of composite structure manufacturing processes and the conservative building regulations concerning materials in all the industrialized countries. However, these three issues are being solved in a very efficient way, as we will see along the coming paragraphs of this paper.
This paper is split in two parts, first the carbon fiber as a material system, its typologies, manufacturing processes and industrial presentations will be described. Second, rehab and building applications will be analyzed.
Viability of utilization of waste materials from ceramic products in precast concretes
Authors: Sánchez de Rojas M. I. , Marín F. P. , Frías M. , Rivera J.
Published: July 2010

The recycled and re-valuation process of waste materials involves studies lead to a deep acknowledges of them, finding applications for their intended use.
The waste materials from ceramic products can be recycled into the construction sector, as arid or pozzolanic materials.
The current work deals with the incorporation of ceramic materials in these two different ways, checking the behaviour of the elaborated mortar by mean of laboratory tests. Also, tests are developed in factory, using these as components for precast concrete tiles.
Evaluation of hexahydrated magnesium chloride (Bischofite) performance as a chemical stabilizer of granular road surfaces
Authors: Thenoux G. , Vera S.
Published: July 2010

Hexahydrated Magnesium Chloride or Bischofite is a salt.
It has different properties that enable it to be useful as a chemical stabilizer of granular road surfaces: its capacity of absorbing and retaining humidity from its surrounding environment, increases water surface tension and decreases its vapor pressure. The objective of this research was to evaluate Bischofite performance as a chemical stabilizer of granular road surfaces. Research was based on laboratory tests and the evaluation of test road sections of granular road surfaces stabilized with Bischofite in arid and semi-arid zones of Chile. In general, the field trial results have been more conclusive than the laboratory tests. The use of Bischofite creates a stable granular road surface, reduces potholes, corrugations, erosion and dust emissions, and improves the riding quality.
Effect of lightweight aggregate intrinsic Strength on lightweight concrete compressive strength and modulus of elasticity
Authors: Videla C. , López M.
Published: July 2010

The study of Structural Lightweight Concrete (SLC), which is a material generally composed of cement, water and lightweight aggregate, has been mainly focused on developing particular cases. Then, the main objective of this research was to generalise the knowledge of this type of material. Particularly, the effect of replacing conventional coarse aggregate by lightweight aggregate on mechanical properties of concrete was studied. SLC may be conceived as a two -phase material. The first phase, composed of cement, water and siliceous natural sand, is called the "resistant phase", and contributes to the structural strength. The second phase is the lightweight phase, comprised of coarse lightweight aggregate, and it is meant to decrease the concrete density. In this way it would be possible to describe the mechanical behaviour of concrete, based on lightweight aggregate and the cement mortar parameters. The obtained results allow for the proposition of relationships between mechanical properties of SLC (such as compressive strength and modulus of elasticity) and the constituent materials properties and amount. At the same time, an easily measured index representing the structural capability of lightweight aggregate is also proposed, this index allows to estimate the potential mechanical properties of concrete which could be obtained by using a particular aggregate.
Evolution and quantification of the main Sensitisers in commercial portland cements
Authors: Frías M. , Sánchez Rojas M. I.
Published: July 2010

The commercial Portland cements contain minor elements in their chemical compositions. The presence of these elements has a direct incidence in different aspects: rheological behaviour, reaction kinetics, environmental, etc. Some of them also have a negative effect on the human health; so, chromium (Cr), nickel (Ni) and cobalt (Co) are the main allergens present in Portland cements, causing of Professional Dermatitis in construction workers.
The current study is focussed on the quantification of total and soluble chromium, nickel and cobalt in a wide range of Spanish commercial cements. These values can represent a contribution to the establishing of possible limitations or reductions of these elements in forthcoming standards.
Analytical data show that clinkers are the main responsibles of the presence of soluble chromium in commercial cements. This fact could be indicating that chromium solubility (from inert Cr III to soluble Cr VI) would be closely related to the clinkerisation conditions. On the other hand, there is not a direct ratio between total chromium and soluble chromium; it means that analytical results are punctual and not any case can be extrapolating ones. Ni and Co solubility in water is practically negligible either raw as clinkers.
Conservation of the stone in Cibeles Fountain, Madrid , Spain
Authors: López de Azcona M. C. , Fort González R. , Mingarro Martín F.
Published: July 2010

The water in Cibeles Fountain flows in a closed circuit and is replaced every 6 months. After this period of time, an increase in bicarbonate, sulfate, calcium and magnesium contents is registered in the water, as well as a slight increase in its acidity. This acidity, favored by atmospheric pollution, is the main cause for the process of dissolution that marble used in the ornamental sections of the fountain undergoes. Calcite-based marble, from the Carrara quarries in Italy, of the cherubs suffers the most acute dissolution processes, while dolomite-based marble, used for the main sculpture body is less affected by these processes. Dissolved materials fall on certain sections of the sculpture and of the fountain forming dirt crusts and inlaid soiling.
In order to prevent decay of the fountain building materials, periodical control of water composition is necessary, with a view to stabilizing water pH level at around 7.8. It is likewise necessary to add chemicals that prevent bacteria and algae proliferation, thus improving water quality.
Novelda Stone: widely used within the Spanish architectural heritage
Authors: Fort R. , Bernabeu A. , García del Cura M. A. , López de Azcona M. C. , Ordóñez S. , Mingarro F.
Published: July 2010

Novelda Stone is a calcareous rock, of the biocalcarenite type. It is extracted from the «Vinalopó Medio» area (Alicante, eastern Spain). Novelda stone is known as construction material from the 13th century. From final of the 19th century until the present time, it has been used in Madrid, Valencia and Alicante. In the past, the main quarries from which this type of rock was extracted were located in the municipal districts of Monóvar (Almorquí Stone), Sax (Portazgo Stone) and Elda (Bateig Stone). Nowadays, the main active extraction site is situated in the Bateig Hill quarries. The rock extracted is known commercially as Bateig Stone. The main varieties of this Bateig Stone are: White, Blue, Layer and Fantasy.
Each variety of Novelda stone has different durability rate and different pathology depending on their characteristics, particularly on their hydric behaviour patterns. Layer Bateig and Portazgo stone undergo granular disintegration and alveolization and are less durable than the rest. White and Blue Bateig, as well as Almorquí stone, only develop fissures or scaling under extreme conditions.
Aired-time and chamotte hydraulic mortars
Authors: González Cortina M. , De Villanueva Domínguez L.
Published: July 2010

The aim of this research project has been to obtain aired-li me based hydraulic mortars with the addition of chamotte or burnt clay powder obtained from the ceramic industry waste. By doing this, hydraulic properties have been included into lime and hydraulic mortars with a great improvement in mechanical properties.
In order to achieve this, different types of chamotte obtained from clay burnt at different temperatures have been tested, changing, at the same time, the proportions of lime, sand, chamotte and water.
All the tests have been performed preparing a double set of test pieces to be kept at room temperature or to be immersed in water, determining the Shore C hardness and the mechanical compressive and tensile strengths. Further on, X-ray diffraction analysis have been developed to determine the qualitative composition of the crystalline structure, as well as micro structural analysis, using stereomicroscope and electric microscope scanning, with X-ray microanalysis have been used.
As a conclusion, several types of mortars have been created with different proportions, which can be used, due to its characteristics, as keying mortars in brickwork, for restoration works as well as for new constructions.
The use of a non-standard high calcium fly ash in concrete and its response to accelerated curing
Authors: Atis C. D. , Bilim C. , Ozcan F. , Akcaozoglu K. , Sevim U. K.
Published: July 2010

An experimental work was carried out to investigate the use of a non-standard high calcium fly ash in concrete. The response of the same fly ash to the accelerated curing was also explored. With three different cementitious material contents, a total of 48 concretes were produced. The water/ cement ratios were varied from 0.40 to 0.87. Compressive strengths of the moist cured cube specimens cast from the concrete mixtures made with 0%, 15%, 30% and 45% replacement of normal Portland cement with fly ash were measured at 28 days and 3 months. Accelerated compressive strengths were also measured using warmwater method and boiling-water method in accordance with the relevant ASTM and Turkish Standards.
Despite the fact that the fly ash used was a non-standard, the laboratory test results showed that it could be utilized in concrete production at a replacement level between 15% and 30% by weight basis because fly ash concrete developed comparable or higher compressive strength than that of corresponding normal Portland cement concrete. The laboratory test results also indicated that the accelerated curing could be used to predict the compressive strength of fly ash concrete with 85% correlation coefficient. The amount of fly ash was found to be immaterial in the strength prediction. The relation between warm-water method and boiling-water method was of linear form with 93% correlation coefficient.
The lime renderings from plaza de la Corredera, Córdoba
Authors: González Limón T. , Álvarez de Buergo Ballester M.
Published: July 2010

The causes of the pathologies found on the lime renderings from Plaza de la Corredera façades are analysed in this study. For this purpose, the mineralogical and chemical analyses of the building materials -brickwork and rendering mortar- has been carried out, as well as their physical, hydric and mechanical properties have been determined. The obtained results from both unaltered and altered materials, and the analysis of the rendering's raw materials, have allowed us to establish that rendering deterioration is connected to the presence of saline compounds (gypsum, halite), which existing in the brickwork substratum, have been removed due to the water saturation of such brickwork.
The main cause responsible of the alteration forms - efflorescence, crusts, grain-disintegration, bulging, flaking found on the renderings, has been the salts precipitation (halite, hexahydrite, epsomite) in their way towards the external surface.
Tests to characterize the behaviour of natural stone in contact with water
Authors: Vielba Cuerpo C. , Hernández Olivares F.
Published: July 2010

This paper presents an experimental analysis of the stone behaviour in contact with water in the different construction uses. In any of these cases is analyse how the water penetrates into the material. As a result of the study the need of modification of the UNE test standards is concluded. It is proposed a procedure to determinate the material's properties and a method to compare and analyse the result obtained that keep into consideration the climate factors. The method have been applied to sandstone of Villamayor (Spain) showing its utility in the analysis of the stone properties.
The influence of natural pozzolana mineralogical composition in the properties of blended cement
Authors: Gener Rizo M. , Alonso Lavernia J. M.
Published: July 2010

The pozzolana activity is the main property of the active additions but, in order to select them, we have to consider - between other factors- its mineralogical composition with a great influence, not only in the active component, but also in other cement properties.
In the present work we have studied 4 different Cuban natural pozzolanes, characterized with the help of X ray diffraction and with thermic and chemical analysis. The pozzolanic activity was also evaluated through a chemical and physicomechanic method. Some cements were prepared with different contents of each one of the pozzolanics, and analysed their physicomechanic and chemical properties.
Finally, we found that the pozzolanics mineralogical composition has a great influence in the pozzolanic activity and in the properties of mixed cements. Also we found that it 5 possible to obtain the best resistances in the time and the smaller needs of water when the vitreous phase prevail in the additions.
Analysis of the strengthenings of mixed glass fibers E and fibers AR in plaster, as an alternative to monofiber (homogeneous) strengthenings
Authors: Del Río Merino M. , Comino P.
Published: July 2010

The company Vetrotex in collaboration with the Department of Architectural Constructions and their control (E.U.A.T) of the Polytechnic University of Madrid, have deeply researched on plaster strengthened with glass fiber E.
The conclusions of the influence of the dispersibility of glass fiber in the compound mechanical behavior and in its workability have been published in an earlier article.
Here now are the results and conclusions of a study on mixed strengthenings of glass fibers E and AR combined at a 50%, as an alternative to the homogenous strengthening.
Characterization of material composite marble-polyester
Authors: Corpas Iglesias F. A. , Iglesias Godino F. J. , Codina Sánchez S. , Ruiz Román J. M. , Ruiz Prieto J. M. , Alonso Santos C.
Published: July 2010

In this work we characterize a new material composite, formed with a polyester and crushed white marble mixture.
The final purpose is double: to obtain a material for applications sufficiently competitive after an economic viability study, increasing the yield of the main commodity, using waste marble and improving the jobs in the quarries area.
From the results obtained, we deduce then that this material could be used to inside and outside adornment.
Historical notes about the development of cement normalization In European Union
Authors: Calleja J.
Published: July 2010

The European Standard EN 197-1:2000 for Cement, prepared by CEN/TC 51, is from now (2002-04-01) onwards, compulsory in all the countries of the European Union. It has been considered suitable to expose some details on the historical development of the steps and difficulties during the elaboration of the standard ENV 197-1:92 first, and of the present and final standard EN 197-1:2000 already in force, and now in Spain as Spanish Standard AENOR/UNE-EN 197-1:2000 (1).
Age and growth of the black scorpionfish, Scorpaena porcus (Pisces: Scorpaenidae) from artificial structures and natural reefs in the Adriatic Sea
Authors: La Mesa Mario , Scarcella Giuseppe , Grati Fabio , Fabi Gianna
Published: July 2010

Age and growth of the black scorpionfish, Scorpaena porcus, were estimated for different populations inhabiting natural reefs and artificial structures (artificial reefs and offshore gas platforms) in the northwestern Adriatic Sea. Annual growth increment counts were carried out on sagittal otoliths of 415 specimens ranging from 80 to 280 mm TL. The accuracy of age estimates was assessed by testing the annual deposition of annuli and the location of the first annulus by marginal increment analysis and daily growth increment counts, respectively. As commonly observed in other scorpaenids, annuli consisted of an alternating pattern of opaque and translucent zones. Marginal increment analysis confirmed that annuli are formed once a year, with opaque zones laid down in spring-summer and translucent zones laid down in autumn-winter. The precision of age estimates was tested by applying both the average percent error (APE) and the mean coefficient of variation (CV). The maximum age estimated for the whole sampled populations was 8 years. The von Bertalanffy growth curves were separately fitted for natural and artificial reef populations of S. porcus. The likelihood ratio test indicated that the overall von Bertalanffy growth curves differed significantly between the two populations. The instantaneous growth rate (k, year-1) and asymptotic length (L∞, cm) were 0.23 and 22.30 and 0.53 and 20.13 for natural and artificial reef populations, respectively. Compared with natural reef population, populations of S. porcus inhabiting artificial reefs and, particularly, offshore platforms, were characterized by larger and older fish. However, young-of-the-year were completely absent from the platform habitats. The effects of artificial structures on S. porcus populations in the study area are discussed in the light of previous results on scorpionfish living in other areas.
Fishery biology of the jumbo flying squid Dosidicus gigas off the Exclusive Economic Zone of Chilean waters
Authors: Liu Bilin , Chen Xinjun , Lu Huajie , Chen Yong , Qian Weiguo
Published: July 2010

The jumbo flying squid Dosidicus gigas is widely distributed in the eastern Pacific Ocean and supports an important fishery. Although many studies have been carried out on the biology of this species, limited biological information is available in the waters outside the Exclusive Economic Zone of Chile (EEZ) (20°S-41°S and 74°30’W-84°W). Three surveys were conducted in this area by the Chinese squid jigging vessels during the period from April 2006 to May 2008. The majority of the catch in the survey was from the two areas defined by 37°30’-41°S and 78°30’-80°W and by 25°-30°S and 76°-77°30’W. The sex ratio (M: F) of the catch was 1: 2.48. The mean mantle length (ML) was 376 mm for males with a range of 257-721 mm and 388.7 mm for females with a range of 236-837 mm. Two distinguished size classes, medium- and large-sized groups, were identified in this study with the medium-sized group (350-450 mm ML) consisting of 89% of the total catch. The sizes at first sexual maturity were 638 mm ML for females and 565 mm ML for males. This study suggests that all the individuals examined were hatched from March 2007 to February 2008, indicating that D. gigas might spawn all year around with a peak spawning time from November 2007 to January 2008. Most of the stomachs analyzed had food remains. The preys included three major groups: fish (mainly lanternfish), cephalopods and crustaceans, but D. gigas was the dominant species in the stomach contents, showing strong evidence of cannibalism. The information obtained from this study improves our understanding of the fishery biology of D. gigas off Chile.
Impacts of transported background ozone on California air quality during the ARCTAS-CARB period – a multi-scale modeling study
Authors: Huang M. , Carmichael G. R. , Adhikary B. , Spak S. N. , Kulkarni S. , Cheng Y. F. , Wei C. , Tang Y. , Parrish D. D. , Oltmans S. J. , D'Allura A. , Kaduwela A. , Cai C. , Weinheimer A. J. , Wong M. , Pierce R. B. , Al-Saadi J. A. , Streets D. G. , Zhang Q.
Published: July 2010

Abstract. Multi-scale tracer and full-chemistry simulations with the STEM atmospheric chemistry model are used to analyze the effects of transported background ozone (O3) from the eastern Pacific on California air quality during the ARCTAS-CARB experiment conducted in June, 2008. Previous work has focused on the importance of long-range transport of O3 to North America air quality in springtime. However during this summer experiment the long-range transport of O3 is also shown to be important. Simulated and observed O3 transport patterns from the coast to inland northern California are shown to vary based on meteorological conditions and the O3 profiles over the oceans, which are strongly episodically affected by Asian inflows. Analysis of the correlations of O3 at various altitudes above the coastal site at Trinidad Head and at a downwind surface site in northern California, show that under long-range transport events, high O3 air-masses (O3>60 ppb) at altitudes between about 2 and 4 km can be transported inland and can significantly influence surface O3 20–30 h later. These results show the importance of characterizing the vertical structure of the lateral boundary conditions (LBC) needed in air quality simulations. The importance of the LBC on O3 prediction during this period is further studied through a series of sensitivity studies using different forms of LBC. It is shown that the use of the LBC downscaled from RAQMS global model that assimilated MLS and OMI data improves the model performance. We also show that the predictions can be further improved through the use of LBC based on NASA DC-8 airborne observations during the ARCTAS-CARB experiment. These results indicate the need to develop observational strategies to provide information on the three-dimensional nature of pollutant distributions, in order to improve our capability to predict pollution levels and to better quantify the influence of these Asian inflows on the US west coast air quality.
Oxidative capacity of the Mexico City atmosphere – Part 2: A ROx radical cycling perspective
Authors: Sheehy P. M. , Volkamer R. , Molina L. T. , Molina M. J.
Published: July 2010

Abstract. A box model using measurements from the Mexico City Metropolitan Area study in the spring of 2003 (MCMA-2003) is presented to study oxidative capacity (our ability to predict OH radicals) and ROx (ROx=OH+HO2+RO2+RO) radical cycling in a polluted (i.e., very high NOx=NO+NO2) atmosphere. Model simulations were performed using the Master Chemical Mechanism (MCMv3.1) constrained with 10 min averaged measurements of major radical sources (i.e., HCHO, HONO, O3, CHOCHO, etc.), radical sink precursors (i.e., NO, NO2, SO2, CO, and 102 volatile organic compounds (VOC)), meteorological parameters (temperature, pressure, water vapor concentration, dilution), and photolysis frequencies. Modeled HOx (=OH+HO2) concentrations compare favorably with measured concentrations for most of the day; however, the model under-predicts the concentrations of radicals in the early morning. This "missing reactivity" is highest during peak photochemical activity, and is least visible in a direct comparison of HOx radical concentrations. We conclude that the most likely scenario to reconcile model predictions with observations is the existence of a currently unidentified additional source for RO2 radicals, in combination with an additional sink for HO2 radicals that does not form OH. The true uncertainty due to "missing reactivity" is apparent in parameters like chain length. We present a first attempt to calculate chain length rigorously i.e., we define two parameters that account for atmospheric complexity, and are based on (1) radical initiation, n(OH), and (2) radical termination, ω. We find very high values of n(OH) in the early morning are incompatible with our current understanding of ROx termination routes. We also observe missing reactivity in the rate of ozone production (P(O3)). For example, the integral amount of ozone produced could be under-predicted by a factor of two. We argue that this uncertainty is partly accounted for in lumped chemical codes that are optimized to predict ozone concentrations; however, these codes do not reflect the true uncertainty in oxidative capacity that is relevant to other aspects of air quality management, such as the formation of secondary organic aerosol (SOA). Our analysis highlights that apart from uncertainties in emissions, and meteorology, there is an additional major uncertainty in chemical mechanisms that affects our ability to predict ozone and SOA formation with confidence.
European summer climate modulated by NAO-related precipitation
Authors: Wang G. , Dolman A. J. , Alessandri A.
Published: July 2010

Abstract. Recent summer heat waves in Europe were preceded by precipitation deficits in winter. Numerical studies suggest that these phenomena are dynamically linked by land-atmosphere interactions. However, there is still no clear evidence that connects summer climate variability to winter precipitation and the relevant circulation pattern so far. Using a technique specially designed for detecting directional influences between climatic fields, we investigate the statistical responses of summer mean as well as maximum temperature variability (June–August, Tmean and Tmax) to preceding winter precipitation (January–March, PJFM) for the period 1901–2005. There appear distinctive Tmean and Tmax responses to PJFM over the Mediterranean, where it is most sensitive to land-atmosphere interactions. An analysis of soil moisture proxy (self-calibrating Palmer drought severity index, scPDSI) shows that the PJFM seems to influence summer temperature via soil moisture, and therefore the Tmean and Tmax responses we present here are very likely to be physical hints of water cycle interactions with temperature. We estimate that roughly 10~20% of the interannual variability of Tmax and Tmean over the Mediterranean is forced by PJFM; for the scPDSI, these values amount to 20~25%. Further analysis shows that these responses are highly correlated to the North Atlantic Oscillation (NAO) regime over the Mediterranean. Therefore we suggest that NAO modulates European summer temperature via controlling precipitation that initializes the moisture states of water cycle interactions with temperature. This clear picture of relations between European summer climate and NAO-related precipitation suggests potential for improved seasonal prediction of summer climate in particular extreme events.
Examination of homogeneity of selected Irish pooling groups
Authors: Das S. , Cunnane C.
Published: July 2010

Abstract. In regional flood frequency estimation, a homogeneous pooling group of sites leads to a reduction in the error of quantile estimators which is the main aim of a regional flood frequency analysis. Examination of the homogeneity of regions/pooling groups is usually based on a statistic that relates to the formulation of a frequency distribution model, e.g. the coefficient of variation (Wiltshire, 1986; Fill and Stedinger, 1995) and/or skew coefficient, their L-moment equivalents (Chowdhury et al., 1991; Hosking and Wallis, 1997) or of dimensionless quantiles such as the 10-yr event (Dalrymple, 1960; Lu and Stedinger, 1992). Hosking andWallis (1993, 1997) proposed homogeneity tests based on L-moment ratios such as L-CV alone (H1) and L-CV & L-skewness jointly (H2) which were also recently investigated by Viglione et al. (2007). In this paper a study, based on annual maximum series obtained from 85 Irish gauging stations, examines how successful a common method of identifying pooling group membership is in selecting groups that actually are homogeneous. Each station has its own unique pooling group selected by use of a Euclidean distance measure in catchment descriptor space, commonly denoted dij and with a minimum of 500 station years of data in the pooling group, which satisfies the 5T rule (FEH, 1999, 3, p. 169) for the 100 yr quantile. It was found that dij could be effectively defined in terms of catchment area, mean rainfall and baseflow index. The sampling distribution of L-CV (t2) in each pooling group and the 95% confidence limits about the pooled estimate of t2 are obtained by simulation. The t2 values of the selected group members are compared with these confidence limits both graphically and numerically. Of the 85 stations, only 1 station's pooling group members have all their t2 values within the confidence limits, while 7, 33 and 44 of them have 1, 2 or 3 or more, t2 values outside the confidence limits. The outcomes are also compared with the heterogeneity measures H1 and H2. The H1 values show an upward trend with the ranges of t2 values in the pooling group whereas the H2 values do not show any such dependency. A selection of 27 pooling groups, found to be heterogeneous, were further examined with the help of box-plots of catchment descriptor values and one particular case is considered in detail. Overall the results show that even with a carefully considered selection procedure, it is not certain that perfectly homogeneous pooling groups are identified. As a compromise it is recommended that a group containing more than 2 values of t2 outside the confidence limits should not be considered homogeneous.
Comparison between radar and rain gauges data at different distances from radar and correlation existing between the rainfall values in the adjacent pixels
Authors: Sebastianelli S. , Russo F. , Napolitano F. , Baldini L.
Published: July 2010

Abstract. Rainfall intensity data in pixels very far from radar are less correlated than values in pixels near the radar, because at far distances the width of a range-bin is comparable or bigger than the pixel width, so in a pixel there are one or just a few rainfall intensity values. Vice versa, near the radar, there are many radar resolution bins which belong to a single pixel, so great correlation between rainfall intensity values for contiguous pixels is expected. Moreover, the signal returned from precipitation at far distance from radar antenna can be due to a radar sample volume partially or completely filled with mixed phase or ice particles, or can be quite close to the minimum detectable signal. All these phenomena can influence the goodness of rainfall estimates, introducing errors which increase as the distance from radar increases. The objective of this work is to characterize these errors as a function of the distance. For this aim is possible to compare the rainfall data obtained by rain gauges at different distances from radar with rainfall radar data at the same distances, verifying the correlation existing between the rainfall values in the adjacent pixels and how the difference between radar and rain gauges data changes. The radar data utilized in this work have been collected from the CNR–ISAC (Institute of Atmospheric Sciences and Climate of the National Research Council) Polar 55C radar in Rome Tor Vergata during 2008.
Microstructural Characteristics of an AZ91 Matrix‐Glassy Carbon Particle Composite
Authors: Olszówka‐Myalska Anita , Myalski Jerzy , Botor‐Probierz Agnieszka
Published: July 2010

This paper presents the results of a microstructural investigation of a new type of ultralight glassy carbon particles (Cp)‐AZ91 magnesium alloy matrix composite manufactured by the powder metallurgy method. Glassy Cp with unmodified surfaces and surfaces modified with SiO2 amorphous nanocoating were used in the experiment. The composite microstructure, with an emphasis given on the interface, was characterized by scanning electron microscope (SEM), TEM, and HRTEM microscopy. Uniform distribution of the particles in the matrix and their good bonding with the metal matrix were observed. A continuous very thin MgO oxide layer containing needle‐like Al2MgO4 phase was detected at the glassy carbon–AZ91 interface. An increase of aluminum concentration at the interface as a result of Mg and Al diffusion into the SiO2 nanolayer was observed in the case of particles modified with SiO2. Crystalline phases containing carbon were not detected at the interface.
High Antibacterial and Antifungal Activity of Silver Monodispersed Nanoparticles Embedded in a Glassy Matrix
Authors: Esteban‐Tejeda Leticia , Malpartida Francisco , Pecharromán Carlos , Moya Jose Serafin
Published: July 2010

Silver doped glass powders have been obtained starting from vitellinate/nAg and montmorillonite/nAg. These powders have shown a high biocide activity against the three different types of microorganisms studied: Escherichia coli (gram‐negative bacteria), Micrococcus luteus (gram‐positive‐bacteria), and Issatchenkia orientalis (yeast). It was found that these glasses keep constant the silver concentration even below the cytotoxic limit. Therefore we interpret that silver doped glasses play the role of dosing devices.
Quantitative Chemical Mapping of Relevant Trace Elements at Biomaterials/Biological Media Interfaces by Ion Beam Methods
Authors: Jallot Edouard , Raissle Olivier , Soulie Jeremy , Lao Jonathan , Guibert Geoffroy , Nedelec Jean‐Marie
Published: July 2010

The definition of biomaterial as proposed by the European Society for Biomaterials in 1986 puts forward the overall importance of the notion of contact between the biomaterial and biological medium (cell, tissue, fluid,…). The underlying concept of biocompatibility makes the interface between biomaterial and biological medium a privileged zone of interest. In this paper, we would like to give an exhaustive view of how ion beams techniques can contribute to a better understanding of such interface taking several examples dealing with bone tissue substitution. After a short presentation of ion beams techniques the paper will focus on PIXE/RBS spectroscopies and will give the basics of these coupled technique. Three examples will then be presented to illustrate the interest of these techniques to study biomaterials/biological interactions. The first example deals with metallic alloys based joint prostheses. The ionic release from the prosthesis and the wear behavior of total knee prostheses will be presented. In the last two examples, bioactive materials will be studied. The common characteristic of bioactive ceramics is the kinetic modification of their surface upon interaction which is ideally monitored by PIXE chemical mapping. The second example will review the benefit of using PIXE/RBS technique to study the effect of doping of bioactive glasses on the very first steps involved in the bioactivity mechanisms like dissolution, ionic release, and biomineralization onto the surface of the glasses. Finally, protein delivery systems based upon mesoporous hydroxyapatites will be studied. Chemical mapping allowing the quantitative determination of protein distribution inside the HAp grains will be presented for the first time.
Co‐Cultures of Primary Cells on Self‐Supporting Nanoporous Alumina Membranes
Authors: Hoess Andreas , Thormann Annika , Friedmann Andrea , Aurich Hendryk , Heilmann Andreas
Published: July 2010

Due to their unique properties, self‐supporting nanoporous aluminum oxide (alumina) membranes are useful substrates for the indirect co‐cultivation of cells. The membrane can act as a physical barrier between different cell types, whereas the cell‐to‐cell communication is guaranteed by the diffusion of soluble molecules or factors through the pores. With the help of such membranes the mRNA expression of hepatic genes can be induced in human adipose‐derived mesenchymal stem cells (hASCs) during an indirect co‐cultivation with primary mouse hepatocytes under different culture conditions. This proof of concept shows that such a cultivation approach is beneficial for different issues in the field tissue engineering or cell therapy.
Inkjet‐Printed Single‐Droplet Organic Transistors Based on Semiconductor Nanowires Embedded in Insulating Polymers
Authors: Lim Jung Ah , Kim Joo‐Hyun , Qiu Longzhen , Lee Wi Hyoung , Lee Hwa Sung , Kwak Donghoon , Cho Kilwon
Published: July 2010

Fabrication of organic field‐effect transistors (OFETs) using a high‐throughput printing process has garnered tremendous interest for realizing low‐cost and large‐area flexible electronic devices. Printing of organic semiconductors for active layer of transistor is one of the most critical steps for achieving this goal. The charge carrier transport behavior in this layer, dictated by the crystalline microstructure and molecular orientations of the organic semiconductor, determines the transistor performance. Here, it is demonstrated that an inkjet‐printed single‐droplet of a semiconducting/insulating polymer blend holds substantial promise as a means for implementing direct‐write fabrication of organic transistors. Control of the solubility of the semiconducting component in a blend solution can yield an inkjet‐printed single‐droplet blend film characterized by a semiconductor nanowire network embedded in an insulating polymer matrix. The inkjet‐printed blend films having this unique structure provide effective pathways for charge carrier transport through semiconductor nanowires, as well as significantly improve the on‐off current ratio and the environmental stability of the printed transistors.
Speed of sound in an optical lattice
Authors: Koinov Z.
Published: July 2010

A system of equal mixture of 6Li atomic Fermi gas of two hyperfine states loaded into a cubic three‐dimensional optical lattice is studied assuming a negative scattering length (BCS side of the Feshbach resonance). When the interaction is attractive, fermionic atoms can pair and form a superfluid. The dispersion of the phonon‐like mode and the speed of sound in the long‐wavelength limit are obtained by solving the Bethe‐Salpeter equations for the collective modes of the attractive Hubbard Hamiltonian.
Sortase transpeptidases: Insights into mechanism, substrate specificity, and inhibition
Authors: Clancy Kathleen W. , Melvin Jeffrey A. , McCafferty Dewey G.
Published: July 2010

Gram‐positive bacteria pose a serious healthcare threat. The growing antibiotic resistance epidemic creates a dire need for new antibiotic targets. The sortase family of enzymes is a promising target for antimicrobial therapy. This review covers the current knowledge of the mechanism, substrate specificity, and inhibitory studies of the Gram‐positive bacter a enzyme sortase. © 2010 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 94: 385–396, 2010.
Ultra scale‐down stress analysis of the bioprocessing of whole human cells as a basis for cancer vaccines
Authors: Acosta‐Martinez J.P. , Papantoniou I. , Lawrence K. , Ward S. , Hoare M.
Published: July 2010

This study examines the use of a capillary shear device for the rapid characterization of human cell lines in terms of their resistance to hydrodynamic stress. An ultra scale‐down (USD) approach is presented to allow the use of small quantities of cells available at the early discovery stage and to expose them to a wide range of hydrodynamic stresses. In this way an indication is gained of the relative properties of different cell lines and the challenge which may be faced during full‐scale processing. A design of experiments approach allowed the interaction between a number of key processing factors such as capillary length, flow rate, and number of passes to be studied in a limited number of experiments. Out of this an USD test based on flow rate in a device of fixed geometry was proposed. Based on observations made elsewhere (Ma et al., 2002, Biotechnol Bioeng 80(4): 428–437) a detailed analysis of possible geometries was performed using a combination of USD experiments and computational fluid dynamics analysis of the capillary entry region. This allowed the properties of the cells to be characterized in terms of a critical stress below which there is no significant loss of cell integrity. The results suggested that the OnyCap23 and P4E6 cell lines, used as components of a whole cell prostate cancer vaccine, are resistant to damage below critical elongational shear stress values of 235 and 275 N/m2, respectively. Above these stress values the loss of intact cells is predicted to be significant; such loss being due to a combination of whole cells becoming permeable to trypan blue and complete breakage of cells into debris at extreme stresses. The sensitivity of cell surface markers CD9, CD44, CD59, CD81, CD147, and MHC‐1 to exposure to shear stress was considerably less than for cell membrane integrity. The surface marker levels for recovered whole cells (i.e., both with and without intact cell membranes) were either independent of shear stress or showed a slight decrease with increased shear stress, for example, as for CD9. The results were used to predict successfully a capillary design where no damage would occur at a specified high flow rate; for example, as required for cell dispensing or vialling operations. Equally, the extent of loss of cell integrity was also successfully predicted in a capillary flow system designed to yield high levels of break up as may be required in intracellular analysis without the use of chemical lysing reagents or relying on autolytic damage. Biotechnol. Bioeng. 2010;107: 953–963. © 2010 Wiley Periodicals, Inc.
Computational Comparison of the Reactions of Substituted Amines with CO2
Authors: Mindrup Elaine M. , Schneider William F.
Published: July 2010

Substituted amines are a popular choice as molecules to selectively react with and separate CO2 from gas mixtures. Such separations are of particular interest, for example, for CO2 separations for carbon capture and sequestration. It is desirable to tune amine–CO2 reaction energies to suit a particular separation. Herein, we use DFT‐B3LYP simulations to characterize the products and energetics of reactions of CO2 with a range of substituted amines, considering both 1:1 and 2:1 amine/CO2 reaction stoichiometries. The results show that by adjusting both the nature and the placement of functional groups, it is possible to tune reaction energies over a substantial range. Decomposition of the 2:1 reaction into separate carbamate and ammonium formation steps shows that the Brønsted basicity and Lewis basicity towards CO2 are largely uncorrelated and provide an independent means of tuning the overall reaction energies.
Targeting of LcrV virulence protein from Yersinia pestis to dendritic cells protects mice against pneumonic plague
Authors: Do Yoonkyung , Koh Hyein , Park Chae Gyu , Dudziak Diana , Seo Patrick , Mehandru S. , Choi Jae‐Hoon , Cheong Cheolho , Park Steven , Perlin David S. , Powell Bradford S. , Steinman Ralph M.
Published: July 2010

To help design needed new vaccines for pneumonic plague, we targeted the Yersinia pestis LcrV protein directly to CD8α+ DEC‐205+ or CD8α− DCIR2+ DC along with a clinically feasible adjuvant, poly IC. By studying Y. pestis in mice, we could evaluate the capacity of this targeting approach to protect against a human pathogen. The DEC‐targeted LcrV induced polarized Th1 immunity, whereas DCIR2‐targeted LcrV induced fewer CD4+ T cells secreting IFN‐γ, but higher IL‐4, IL‐5, IL‐10, and IL‐13 production. DCIR‐2 targeting elicited higher anti‐LcrV Ab titers than DEC targeting, which were comparable to a protein vaccine given in alhydrogel adjuvant, but the latter did not induce detectable T‐cell immunity. When DEC‐ and DCIR2‐targeted and F1‐V+ alhydrogel‐vaccinated mice were challenged 6 wk after vaccination with the virulent CO92 Y. pestis, the protection level and Ab titers induced by DCIR2 targeting were similar to those induced by F1‐V protein with alhydrogel vaccination. Therefore, LcrV targeting to DC elicits combined humoral and cellular immunity, and for the first time with this approach, also induces protection in a mouse model for a human pathogen.
Particle filters and Bayesian inference in financial econometrics
Authors: Lopes Hedibert F. , Tsay Ruey S.
Published: July 2010

In this paper we reviewsequential Monte Carlo(SMC) methods, or particle filters (PF), with special emphasis on its potential applications in financial time series analysis and econometrics. We start with the well‐known normal dynamic linear model, also known as the normal linear state space model, for which sequential state learning is available in closed form via standard Kalman filter and Kalman smoother recursions. Particle filters are then introduced as a set of Monte Carlo schemes that enable Kalman‐type recursions when normality or linearity or both are abandoned. The seminalbootstrap filter(BF) of Gordon, Salmond and Smith (1993) is used to introduce the SMC jargon, potentials and limitations. We also review the literature on parameter learning, an area that started to attract much attention from the particle filter community in recent years. We give particular attention to the Liu–West filter (2001), Storvik filter (2002) andparticle learning(PL) of Carvalho, Johannes, Lopes and Polson (2010). We argue that the BF and theauxiliary particle filter(APF) of Pitt and Shephard (1999) define two fundamentally distinct directions within the particle filter literature. We also show that the distinction is more pronounced with parameter learning and argue that PL, which follows the APF direction, is an attractive extension. One of our contributions is to sort out the research from BF to APF (during the 1990s), from APF to now (the 2000s) and from Liu–West filter to Storvik filter to PL. To this end, we provide code in R for all the examples of the paper. Readers are invited to find their own way into this dynamic and active research arena. Copyright © 2010 John Wiley & Sons, Ltd.
Deuterium exchange promoted by iridium complexes formed in situ
Authors: Herbert John M.
Published: July 2010

For many exchange processes using iridium catalysts, the use of isolated pre‐catalysts may be preferred. However, the generation and use of iridium complexes in situ provides a useful option where the intention is to examine a range of ligand systems or where the pre‐catalyst is not readily isolated. Copyright © 2010 John Wiley & Sons, Ltd.
Corrosion behaviour of electrodeposited Ni/Al2O3 composite coating covered with a NaCl salt film at 800 °C
Authors: Chang L. M. , Liu J. H. , Zhang R. J.
Published: July 2010

The electrodeposited Ni/Al2O3 composite coatings were prepared by direct current (DC), pulse current (PC) and pulse reversal current (PRC) deposition, respectively. The corrosion behaviour of electrodeposited Ni/Al2O3 composite coatings covered with NaCl salt films at 800 °C in air was investigated by SEM/EDX, XRD and thermogravimetric analysis. It is found that corrosion of the three types of coatings is seriously aggravated with a present NaCl salt film, and a corrosion layer with a poor adherence to the matrix has been formed. Furthermore, chlorine enrichment at the interface between the matrix and the corrosion product has been observed. The corrosion resistance of the three types of coatings has improved with the increase of Al2O3 content. The corrosion resistance of the Ni/Al2O3 composite coatings prepared by PRC deposition is the best, and that by DC deposition is the worst. The corrosion mechanism of Ni/Al2O3 composite coatings will also be discussed.