bluuebunny/crossref_metadata_2025 huggingface dataset:
An analytical comparison of two commercial consolidating products applied to eocene sandstones from 16th and 19th century monuments in San Sehastián, northern Spain
Authors: García-Garmilla F. , Rodríguez Maribona I. , Cano M. , Zalbide M. , Ibáñez-Gómez J. A. , Osa-Chans E. , Garín S.
Published: July 2010

The conservation of buildings in the Basque Country made of Eocene sandstone is somewhat problematical, because this type of rock is relatively unstable. This instability is due to the variable content of carbonate cement (0-28%) and the presence of K-feldspar grains (1-13%) which appear to have been dissolved by both diagenetic and environmental processes. We have compared the results of the application of two commercial consolidating products: Sicof SM 296 (product A) and Consistone FS-hA (product B), both ethylsilicates, on Eocene sandstones of the Oquendo Admiral House (16th century) and the Gipuzkoa Provincial Government Palace (19th century), which are both located in the city of San Sebastián (Province of Gipuzkoa, Basque Country, Northern Spain). On the basis of different chemical and physical laboratory tests, together with Scanning Electron Microscopy (SEM) analysis, product A seems to be more efficient in consolidating such Eocene sandstone materials, since it penetrates into the first 8 mm of the rock, occupies very homogeneously even the smallest pore spaces and leaves a certain degree of remaining porosity which allows ventilation of the rock. In contrast, product B seems to be more appropriate for larger pore-sized rocks, because it only penetrates into the first 3 mm of the Eocene sandstone samples due to the thin pores of the matter. Our results demonstrate that the suitability of a commercial product depends not only on its own chemical composition, but also on the textural and lithological features of the rock material upon which it is to be applied.
Ornamental sandstones used in Ciudad Rodrigo, Salamanca: petrographic and chemical characterization of the quarry materials
Authors: Varas M. J. , Molina E. , Vicente M. A.
Published: July 2010

Petrographic and chemical study of the Ciudad Rodrigo (province of Salamanca, Spain) sandstones reveals the existence of several types of stone (Red, Brown, Striped, Nodular and White). To some extent all of them have been used in the construction of the historical part of this city. The proximity of the quarries to the city has meant that they have been used for such purposes since remote times.
The types of stone display important chemical and mineralogical variations as a result of the many diagenetic processes they have been subjected to over time. These alterations are reflected in the different varieties, whose splendor can be fully appreciated in the masonry of the historical buildings comprising the architectural ensemble of the city.
Causes and effects of the corrosion of a plumbing galvanised steel
Authors: Alejandre Sánchez F. J. , Lucas Ruiz R
Published: July 2010

Hot dip galvanising life as a corrosion protective coatings on steel depends basically on three factors: coatings quality (thickness), correct installation of the galvanised article, and weathering effects.
The aim of this research it is to study the decaying causes and effects of a plumbing installation made with hot dip galvanised steel tubes. The mentioned installation was of use during 30 years in the water supply system of the Parque Alcosa market (Sevilla, Spain). The research was divided in three parts: in the first one, shape analysis and XDR of internal decayed products was carried out: in the second one, physical properties were determined according to UNE 37- 505-89, corrosion morphology was conducted by metalographic microscopy, and it was evaluated also water quality: and finally, in the third one, diameter, section, and internal volume decrease was calculated in order to evaluate friction increase and pressure decrease in the installation.
The results obtained show the correct plumbing installation according to quality requirements (UNE 37-509-89), so corrosion causes are mainly attributed to an aggressive environment for the hot dip galvanising.
Kinetic study of a grinding system in a cuban cement factory
Authors: Salas Vinent M. E. , Rabilero Bouza A. C. , Córdoba Rodríguez V.
Published: July 2010

A kinetic study realized in a moulding system in a cement factory ("Palmarito de Cauto" Santiago de Cuba) is presented. This objective of this study is the production of a pozzolonic cement PZ-250 with an addition until 40% of pozzolan.
The present paper confirms the satisfactory predictions and permits to recommend the utilization it as a available way of economical efficiency.
Alkaline cement mortars. Chemical resistance to sulfate and seawater attack
Authors: Puertas F. , Gutiérrez R. , Fernández-Jiménez A. , Delvasto S. , Maldonado J.
Published: July 2010

The durability and chemical resistance of alkali activated slag and fly ash/slag mortars in contact with sulfates and seawater media have been studied. Two methods were used in the evaluation of such durability: Kock-Steinegger and ASTM C1012. A mineralogical and a microstructural characterization of mortars were done at different ages of their conservation in aggressive media through XRD, SEM/ EDX and mercury porosimetry.
Results showed a high durability of activated cement mortars in sulfates and seawater media. NaOH activated mortars are the most sensitive to environment attack with formation of expansive products as gypsum and ettringite, although in very low proportion.
Evolution of the hydration in cements with additions
Authors: Bonavetti V. L. , Rahhal V. F. , Irassar E. F.
Published: July 2010

In this paper, the hydration mechanism of portland cement pastes with limestone, quartz and natural pozzolan (80/20 weight) was analized. The techniques used were nonevaporable water content, pozzolanic activity and X-ray diffraction. Results show that filler effect increases initially the amount of hydration products in all pastes. For limestone pastes, the dilution effect is significant at long time, for quartz and pozzolan pastes the dilution effect was lower due to the contribution of the pozzolanic reaction.
Preparation of Cathode Materials for a Lithium-Ion Battery Using an Industrial Microwave Furnace
Authors: Higuchi Masashi , Suzuki Kota , Katayama Keiichi , Nakamura Toshiki , Kagohashi Akira , Kinoshita Akihiro , Suzuki Hiromitsu
Published: July 2010

Cathode materials for a lithium-ion battery were prepared using an industrial microwave furnace. The prepared materials were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and electrochemical properties. Single-phase LiMn2O4 powders could be prepared in a few minutes using an industrial microwave furnace. The obtained results showed that this microwave heating method is a promising industrial technique for efficient preparation of cathode materials.
Evaluation of the Structures and Oxidation Resistances of MoSi2-Si Composite Thin Films
Authors: Hayashi Teppei , Sato Yuuki , Yoshikado Shinzo
Published: July 2010

Thin films of mixtures of molybdenum silicate (MoSi2) and silicon (Si) (MoSiX, where the Mo to Si molar ratio = 1:X) were deposited on silicon nitride (Si3N4) polycrystalline substrates by radio-frequency magnetron sputtering using a target made of a mixture of MoSi2 and Si powders. The crystal structure of MoSiX thin films deposited on the Si3N4 substrate consisted of a mixture of a hexagonal phase and an unknown phase when X > 2.05. A thin film consisting almost entirely of the unknown phase could be deposited when X = 2.1−2.15. Molybdenum silicate can exist in the forms Mo3Si, Mo5Si3, or MoSi2, but to date there has been no report of molybdenum silicate having a Si to Mo molar composition ratio of larger than 2. It was found that the surfaces of thin films of the hexagonal phase or the unknown phase were readily oxidized, whereas the surfaces of thin films of a mixture of the hexagonal phase and the unknown phase exhibit excellent oxidation resistance in air at temperatures up to 700 °C.
Comparison of Thermal Stability of Epitaxially Grown (La0.5Sr0.5)CoO3 and (La0.6Sr0.4)MnO3 Thin Films Deposited on Si Substrate
Authors: Sawamura Shigeki , Sakamoto Naonori , Fu De Sheng , Shinozaki Kazuo , Suzuki Hisao , Wakiya Naoki
Published: July 2010

Thermal stability of bottom electrode thin films (La0.5Sr0.5)CoO3 (LSCO) and (La0.6Sr0.4)MnO3 (LSMO) were investigated. The crystallization and surface morphology of the heterostructure were characterized using x-ray diffraction and atomic force microscopy. Resistivity of the LSCO thin film was 25 cm. However, the resistivity of LSCO thin film increases sharply with annealing temperature. The LSMO thin film has high resistivity (100 mcm). The film does not decompose after thermal processing at 900 °C. To confirm thermal stability, we examined the effect of post annealing at various temperatures on the morphology and resistivity. Results showed that LSMO has higher thermal stability than that of LSCO.
Dielectric and Piezoelectric Properties of (Na,Ba)(Nb,Ti)O3 Lead-Free Piezoelectric Ceramics
Authors: Aoyagi Rintaro , Iwata Makoto , Maeda Masaki
Published: July 2010

(Na1-xBax)(Nb1-xTix)O3 (NNBTx; x=0.0-0.21) solid-solution ceramics were synthesized and their crystal structure, dielectric properties and piezoelectric properties were investigated. The crystal structure at room temperature of NNBTx varied from orthorhombic to tetragonal with increasing BaTiO3 content x. The phase boundary between orthorhombic and tetragonal at room temperature was confirmed BT content between x=0.08 and 0.09. For x>0.05, it was found that the Curie temperature was decreased with increasing x. The highest electromechanical coupling factor, kp, and the largest piezoelectric constant, d33, were obtained at x=0.09-0.10.
Experimental and Numerical Modelling of LRI Process
Authors: Brault Romain , Niquet Michel , Mistou Sébastien
Published: July 2010

The aim of this study is to gain knowledge concerning the process and its physics, as well as to
become able to optimize the fabrication of large and complex composite parts in aeronautics appli-
cations. Composite materials have many advantages and the use of this technology is increasing in
the aeronautic industry. In the L.R.I. process, dry textile preforms are impregnated by a thermoset
liquid resin. All the elements are enclosed in a vacuum bag of known pressure. Once preforms
are totally impregnated, the resin system begins the curing reaction to obtain the composite part.
This study contains two major sections. Firstly, numerical modeling was done with the Pam- Rtm
nite element code to determine the evolution of the ow front during the infusion. Simulations
were performed to analyse the infusion of sandwich composite parts with a perforate foam, which
allows the inferior skin to be impregnated in the same operation. Secondly, experimental work was
conducted to conrm the numerical results.
An Enhanced Algorithm for Detecting Blisters of Glass by Machine Vision
Authors: Han Chang Ho , Ryu Young Kee , Oh Choon Suk , Choi Byoung Wook
Published: July 2010

In this paper, we proposed image processing algorithms and developed the vision system for measuring blisters of flat glasses. The images captured by changing focus of camera because the depth of field of CCD camera is smaller than the depth of glasses and classified two types in blister as circle and ellipse types by the proposed criteria of measurement. We applied different methods to each type to improve the accuracy. In the pre-processing, it obtained binarized images to find blister. The information such as area, boundary, length, and position of blister has extracted from the binarized images by using chain code algorithm. For an illumination, the bright field illumination as back-light was applied. We tested the automatic measurement system, which we developed by using vision system, It successes 100% for detecting the blister at all glasses, and the error accuracy of information is about +/-10%.
In-Flight Behaviors and Properties of Plasma-Sprayed Tungsten Coatings
Authors: Niu Ya Ran , Hu De Yang , Ji Heng , Zheng Xue Bin
Published: July 2010

Tungsten is one of the most promising candidates for the plasma facing materials (PFM) in fusion experiment devices. In this study, tungsten coatings were fabricated on copper alloy substrates via air plasma spraying technology. The in-flight behaviors of tungsten particles in the spraying process were investigated. The microstructure and some properties of the as-sprayed coatings, including surface roughness, bonding strength, microhardness and thermal property, were evaluated. The results showed that the temperature and velocity of the in-flight tungsten particles increased by enhancing the spraying power. Un-melted particles and microcracks were found for the coatings prepared under the low (32.7kW) and high (47.6kW) spraying powers, respectively. The highest bonding strength and microhardness were obtained for the coating prepared under a medium spraying power (42.5kW) by reason of its good in-flight behaviors. The thermal conductivity of tungsten coatings was 32.2 W٠K-1٠m-1 at room temperature, which was much lower than that of bulk tungsten.
Evaluation on Application of Artificial Soil Made by Organic Wastes
Authors: Yoo Yeong Seok , Chae Ho Jun , Ban Hyo Jin , Park Eun Zoo
Published: July 2010

Natural soil would be used for planting on paved area ground, but it had been replaced by the light weighted artificial soil to minimize burden of the structure. But, the existing light weighted soil had nearly capacity of fertilizer adsorption due to its glassy surface. In this study, the artificial soil prepared by sewage sludge was manufactured, tested characteristics as soil and examined on planting. The developed soil was analyzed through specific gravity, pH, water content, volatile matter and was tested on adsorption capacity of Cu. In addition, planting examination analyzed the leaf growth of planting and mouseear cress plant's pollen. As the result, the developed artificial soil showed to be color yellowish brown, bulk density 0.6g/cm3, pH 8~9, volatile matter 0.3, CEC 10, pressure strength 25 ton/m2, hydrophilic and non-toxic, which was suitable for rooftop gardening. Also, periodic growth rate and development of leaves was satisfactory as natural soil and growth and numbers of pollens were good. Consequently, the developed artificial soil with porosity and capacity of fertilizer adsorption could be usefully applicable to planting on the paved area.
Eco-Friendly Fabrication Process of AlTiC Grain Refiner
Authors: Cho Hoon
Published: July 2010

In order to fabricate an aluminum grain refiners such as AlTiB and AlTiC, environmentally damaging fluoride-containing fumes induces an expensive emission control system. Furthermore, the problems associated with boride agglomeration in AlTiB refiner and expensive fabrication cost of AlTiC refiner have created a demand for boron-free and cheaper grain refiners. In the present study, Eco-friendly (K2TiF6-less) fabrication process of fading-less AlTiC refiner was investigated by an in-situ TiC formation through an melting of cheap Al-Ti master alloy in Graphite crucible and atomization of AlTiC melts producing AlTiC powders containing carbon with 250ppm. We aimed at evaluation of fading mechanism, then prevention of the fading at relative long holding time as well as substitution of AlTiB grain refiner for eco-friendly and cheaper cost.
Corrosion Control of Drinking Water Copper Pipes by Corrosion Inhibitor
Authors: Ahn Jae Hwan , Lee Hyun Dong , Kim Seog Ku , Kwak Pill Jae , Lee Joo Yeon
Published: July 2010

In case of cleaning the tap water in Korea, focus has been concentrated on how to improve water quality during the process of purification after taking in original water. However, the interest in human health has been increased, so 'secondary contamination' ,polluted in the process of crossing water reservoir, distributing pipes, indoor water tanks and water pipes after water left a filtration plant, is soared up as an important object of water quality control. Especially the copper pipe for the tap water, its characteristic was acknowledged as a pipe with many merits such as excellent corrosion resistance and easy assembly at the time to lay, is being frequently used in the advanced countries like East Europe, North America, Australia, etc, and is also being used as the material of pipe laying among the pipes for distributing water in Germany and Netherlands. But in case of Korea, the blue or green water problem is found even in the less than 6 year old copper pipes after being installed newly in indoor pipe laying for water distributing that causes to bring about aesthetic distrust to citizens, so the necessity of study is raised to control this situation.
In this study tried to control the corrosion and the blue and green water problem happening in the copper pipe using corrosion inhibitors to settle down the various problems available to happen by this problem and suggested an optimized method to manage this situation.
Microstructure and Wear Performance of Cu-Mo-Si Alloys Fabricated by Self-Propagation High-Temperature Synthesis
Authors: Xie Hui , Jia Lei , Wang Si Ming , Zhu Ji Ling , Lu Zhen Lin
Published: July 2010

Cu-Mo-Si alloys with different Cu contents were prepared by self-propagation high-temperature synthesis (SHS). The microstructure and the worn surface morphology were observed using scanning electron microscopy (SEM) together with energy dispersive X-ray spectroscopy (EDS) analysis. Phase composition was determined by X-ray diffraction (XRD). The wear behavior of the Cu-Mo-Si alloys was characterized by pin-on-disc wear tester. The results showed that most of Si atoms dissolved in Cu matrix or resulted in formation of compound with Cu, while only small amount of Si atoms reacted with Mo atoms to form Mo5Si3 particles in the Cu-Ni-Si alloys with 80% Cu content. The wear rate of Cu-Mo-Si alloys descended with a decrease of Cu content, and the predominant wear mechanism could be identified as abrasive wear for Cu content less than 90% and plastic deformation for Cu content higher than 90%.
Electrodeposition of Ni-SiC Nano Composite in Presence of Ultrasound
Authors: Gyawali Gobinda , Cho Sung Hun , Woo Dong Jin , Lee Soo Wohn
Published: July 2010

Ni-SiC nano composite coatings were fabricated using electrodeposition technique with the aid of ultrasound. The properties of the nano composite were investigated using SEM and Vicker’s microhardness tester. The results demonstrated that the microhardness of composite coatings under ultrasonic vibrations was improved significantly as compared to conventional electrodeposition techniques without ultrasound. The nano particles were found to be distributed homogeneously with reduced agglomeration due to the ultrasonic vibration.
Synthesis and Characterization of Dumbbell Shaped Calcium Carbonate Induced by Lignin
Authors: Zhu Wen Kun , Luo Xue Gang , Luo An Kai , Liang Xuan
Published: July 2010

Calcium carbonate with various structures and morphologies were prepared under double injection of the CaCl2 and Na2CO3 solutions with molar ratio of 1:1 at 30 °C, taking lignin as the induction agents. They were characterized by scanning electron microscopy, infrared spectroscopy thermal analysis and X-ray diffraction. The synthesis mechanism was also discussed. The results showed that calcium carbonate of different shape were obtained with the concentration of lignin at 10g/L, 20g/L and 30g/L, respectively, under 30°C while CaCl2 and Na2CO3 were kept at the same concentration of 0.5mol/L. The size of the particles was in a range between 3 and 5μm and the particles were calcites. Compared with the normal calcium carbonate, the compound has advanced thermal decomposition behavior. Fourier transform infrared spectroscopy (FT-IR) analysis revealed the presence of lignin and calcite. The electrostatic interaction of Ca2+ with lignin and the complementary of stereo-structure play important roles in the formation of Dumbbell Shaped Calcium Carbonate.
ROLE AND TIMING OF HEMATOPOIETIC CELL TRANSPLANTATION FOR MYELODYSPLASTIC SYNDROME
Authors: Field Teresa L , Anasetti Claudio
Published: July 2010

Allogeneic hematopoietic cell transplantation (HCT) is the only curative treatment for patients with myelodysplastic syndromes (MDS).  Most patients with MDS are older than 60 years and age-associated morbidities limit the patients’ options for curative transplant therapy.  Since the development of conditioning regimens with reduced toxicity, the age limitations for HCT have waned for those patients with good performance status. This review will discuss the role of HCT for MDS based on prognostic features, the optimal timing of HCT, and outcomes based on patient age.
Regularity and dimension spectrum of the equivariant spectral triple for the odd-dimensional quantum spheres
Authors: Pal Arupkumar , Sundar S.
Published: July 2010

The odd-dimensional quantum sphere

S_q^{2ℓ + 1}

is a homogeneous space for the quantum group

\mathrm{SU}_q(ℓ + 1)

. A generic equivariant spectral triple for

S_q^{2ℓ + 1}

on its

L_2

-space was constructed by Chakraborty and Pal in [4]. We prove regularity for that spectral triple here. We also compute its dimension spectrum and show that it is simple. We give a detailed construction of its smooth function algebra and some related algebras that help proving regularity and in the computation of the dimension spectrum. Following the idea of Connes for

\mathrm{SU}_q(2)

, we first study another spectral triple for

S_q^{2ℓ + 1}

equivariant under torus group action and constructed by Chakraborty and Pal in [3]. We then derive the results for the

\mathrm{SU}_q(ℓ + 1)

-equivariant triple in the case

q = 0

from those for the torus equivariant triple. For the case

q ≠ 0

, we deduce regularity and dimension spectrum from the case

q = 0

.
Potential for the use of reconstructed IASI radiances in the detection of atmospheric trace gases
Authors: Atkinson N. C. , Hilton F. I. , Illingworth S. M. , Eyre J. R. , Hultberg T.
Published: July 2010

Abstract. Principal component (PC) analysis has received considerable attention as a technique for the extraction of meteorological signals from hyperspectral infra-red sounders such as the Infrared Atmospheric Sounding Interferometer (IASI) and the Atmospheric Infrared Sounder (AIRS). In addition to achieving substantial bit-volume reductions for dissemination purposes, the technique can also be used to generate reconstructed radiances in which random instrument noise has been reduced. Studies on PC analysis of hyperspectral infrared sounder data have been undertaken in the context of numerical weather prediction, instrument monitoring and geophysical variable retrieval, as well as data compression. This study examines the potential of PC analysis for chemistry applications. A major concern in the use of PC analysis for chemistry is that the spectral features associated with trace gases may not be well represented in the reconstructed spectra, either due to deficiencies in the training set or due to the limited number of PC scores used in the radiance reconstruction. In this paper we show examples of reconstructed IASI radiances for several trace gases: ammonia, sulphur dioxide, methane and carbon monoxide. It is shown that care must be taken in the selection of spectra for the initial training set: an iterative technique, in which outlier spectra are added to a base training set, gives the best results. For the four trace gases examined, key features of the chemical signatures are retained in the reconstructed radiances, whilst achieving a substantial reduction in instrument noise. A new regional re-transmission service for IASI is scheduled to start in 2010, as part of the EUMETSAT Advanced Retransmission Service (EARS). For this EARS-IASI service it is intended to include PC scores as part of the data stream. The paper describes the generation of the reference eigenvectors for this new service.
On the importance of sublimation to an alpine snow mass balance in the Canadian Rocky Mountains
Authors: MacDonald M. K. , Pomeroy J. W. , Pietroniro A.
Published: July 2010

Abstract. A modelling study was undertaken to evaluate the contribution of sublimation to an alpine snow mass balance in the Canadian Rocky Mountains. Snow redistribution and sublimation by wind, snowpack sublimation and snowmelt were simulated for two winters over an alpine ridge transect located in the Canada Rocky Mountains. The resulting snowcover regimes were compared to those from manual snow surveys. Simulations were performed using physically based blowing snow (PBSM) and snowpack ablation (SNOBAL) models. A hydrological response unit (HRU)-based spatial discretization was used rather than a more computationally expensive fully-distributed one. The HRUs were set up to follow an aerodynamic sequence, whereby eroded snow was transported from windswept, upwind HRUs to drift accumulating, downwind HRUs. That snow redistribution by wind can be adequately simulated in computationally efficient HRUs over this ridge has important implications for representing snow transport in large-scale hydrology models and land surface schemes. Alpine snow sublimation losses, in particular blowing snow sublimation losses, were significant. Snow mass losses to sublimation as a percentage of cumulative snowfall were estimated to be 20–32% with the blowing snow sublimation loss amounting to 17–19% of cumulative snowfall. This estimate is considered to be a conservative estimate of the blowing snow sublimation loss in the Canadian Rocky Mountains because the study transect is located in the low alpine zone where the topography is more moderate than the high alpine zone and windflow separation was not observed. An examination of the suitability of PBSM's sublimation estimates in this environment and of the importance of estimating blowing snow sublimation on the simulated snow accumulation regime was conducted by omitting sublimation calculations. Snow accumulation in HRUs was overestimated by 30% when neglecting blowing snow sublimation calculations.
A longitudinal study to explain the pain‐depression link in older adults with osteoarthritis
Authors: Hawker Gillian A. , Gignac Monique A. M. , Badley Elizabeth , Davis Aileen M. , French Melissa R. , Li Ye , Perruccio Anthony V. , Power J. Denise , Sale Joanna , Lou Wendy
Published: July 2010

Objective

To evaluate whether osteoarthritis (OA) pain determines depressed mood, taking into consideration fatigue and disability and controlling for other factors.

Methods

In a community cohort with hip/knee OA, telephone interviews assessed OA pain and disability (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]), fatigue (Multidimensional Fatigue Symptom Inventory), depressed mood (Center for Epidemiologic Studies Depression Scale), and covariates (demographics, self‐rated health, comorbidity, pain coping, pain catastrophizing, and social support) at 3 time points over 2 years. Drawing on previous research, a path model was developed to test the interrelationships among the key concepts (pain, depression, fatigue, disability) over time, controlling for covariates.

Results

The baseline mean age was 75.4 years; 78.5% of the subjects were women, 37.2% were living alone, and 15.5% had ≥3 comorbid conditions. WOMAC scores indicated moderate OA symptoms and disability. From the final model with 529 subjects, adjusting for covariates, we found that current OA pain strongly predicted future fatigue and disability (both short and long term), that fatigue and disability in turn predicted future depressed mood, that depressed mood and fatigue were interrelated such that depressed mood exacerbated fatigue and vice versa, and that fatigue and disability, but not depressed mood, led to worsening of OA pain.

Conclusion

Controlling for other factors, OA pain determined subsequent depressed mood through its effect on fatigue and disability. These effects led to worsening of pain and disability over time. These results support the need for improved pain management in OA to prevent or attenuate the downstream effects of pain on disability and mood.
Tuning the Composition and Nanostructure of Pt/Ir Films via Anodized Aluminum Oxide Templated Atomic Layer Deposition
Authors: Comstock David J. , Christensen Steven T. , Elam Jeffrey W. , Pellin Michael J. , Hersam Mark C.
Published: July 2010

Nanostructured metal films have been widely studied for their roles in sensing, catalysis, and energy storage. In this work, the synthesis of compositionally controlled and nanostructured Pt/Ir films by atomic layer deposition (ALD) into porous anodized aluminum oxide templates is demonstrated. Templated ALD provides advantages over alternative synthesis techniques, including improved film uniformity and conformality as well as atomic‐scale control over morphology and composition. Nanostructured Pt ALD films are demonstrated with morphological control provided by the Pt precursor exposure time and the number of ALD cycles. With these approaches, Pt films with enhanced surface areas, as characterized by roughness factors as large as 310, are reproducibly synthesized. Additionally, nanostructured PtIr alloy films of controlled composition and morphology are demonstrated by templated ALD, with compositions varying systematically from pure Pt to pure Ir. Lastly, the application of nanostructured Pt films to electrochemical sensing applications is demonstrated by the non‐enzymatic sensing of glucose.
Piecewise linear relaxation of bilinear programs using bivariate partitioning
Authors: Hasan M. M. Faruque , Karimi I.A.
Published: July 2010

Several operational and synthesis problems of practical interest involve bilinear terms. Commercial global solvers such as BARON appear ineffective at solving some of these problems. Although recent literature has shown the potential of piecewise linear relaxation via ab initio partitioning of variables for such problems, several issues such as how many and which variables to partition, which partitioning scheme(s) and relaxation model(s) to use, placement of grid points, etc., need detailed investigation. To this end, we present a detailed numerical comparison of univariate and bivariate partitioning schemes. We compare several models for the two schemes based on different formulations such as incremental cost (IC), convex combination (CC), and special ordered sets (SOS). Our evaluation using four process synthesis problems shows a formulation using SOS1 variables to perform the best for both partitioning schemes. It also points to the potential usefulness of a 2‐segment bivariate partitioning scheme for the global optimization of bilinear programs. We also prove some simple results on the number and selection of partitioned variables and the advantage of uniform placement of grid points (identical segment lengths for partitioning). © 2009 American Institute of Chemical Engineers AIChE J, 2010
Classifying the fluidization and segregation behavior of binary mixtures using particle size and density ratios
Authors: Rao Akhil , Curtis Jennifer S. , Hancock Bruno C. , Wassgren Carl
Published: July 2010

Experimental investigations show that fluidized binary mixtures exhibit varied pressure drop profiles and segregation patterns, depending on the level of disparity due to size and/or density differences. In this study, different mixture types are mapped on a graph of density versus size ratios. It is found that the ratio of the minimum fluidization velocities of individual components can be used to categorize these mixtures. A simple correlation is developed to compute the ratio of the minimum fluidization velocities based on the density and size ratios. Categorizing the binary mixtures in this manner gives a qualitative understanding of how the different mixtures behave on fluidization. © 2010 American Institute of Chemical Engineers AIChE J, 2011
Conceptual design of distillation processes for mixtures with distillation boundaries: I. Computational assessment of split feasibility
Authors: Brüggemann Stefan , Marquardt Wolfgang
Published: July 2010

Geometric design methods for the conceptual design of azeotropic distillation processes are fast and efficient tools for the economic screening of different process alternatives. This two‐part series presents a fully automated conceptual design method for finding an optimal recycle policy for the separation of mixtures with distillation boundaries. It does not require visualization and graphical inspection of residue curve or pinch maps and is, hence, not limited to ternary mixtures. The first part introduces a fully computational geometric split feasibility test based on bifurcation analysis. This bifurcation‐based feasibility test can be used as a valuable stand‐alone tool for the assessment of different separation options. It is also one of the core elements of the recycle optimization discussed in the second part of this series. © 2010 American Institute of Chemical Engineers AIChE J, 2011
Nanostrukturierte Kohlenstoffmaterialien aus molekularen Vorstufen
Authors: Hoheisel Tobias N. , Schrettl Stephen , Szilluweit Ruth , Frauenrath Holger
Published: July 2010

Nanostrukturierte Kohlenstoffmaterialien, also Kohlenstoffe, die eine charakteristische Größe im Nanometerbereich sowie eine eventuell funktionalisierte Oberfläche aufweisen, spielen eine zentrale Rolle in vielen wissenschaftlichen Disziplinen. Erste Anwendungen finden derartige Materialien dabei unter anderem in Bereichen wie der Erforschung alternativer Energiequellen, leistungsfähiger Energiespeichermaterialien, nachhaltiger chemischer Technologien oder auch im Gebiet der organisch‐elektronischen Materialien. Des Weiteren könnten diese Materialien mögliche Ansätze und Lösungen bieten, um dem voranschreitenden Verbrauch fossiler Brennstoffe und somit dem Klimawandel entgegenzusteuern. Ferner könnten nanostrukturierte Kohlenstoffmaterialien auch auf dem Gebiet der Mikroelektronik einen Durchbruch herbeiführen. Allerdings ist die Entwicklung neuer Herstellungsverfahren für kohlenstoffreiche Materialien unabdingbar, die unter anderem Kontrolle über die Oberflächenchemie, die mesoskopische Struktur und die Mikrostruktur ermöglichen. Ein vielversprechender Ansatz ist dabei die Synthese dieser Materialien aus wohldefinierten molekularen Vorstufen.
Zum Wirkungsbereich der chemischen Synthese: Aufbau einer Minipipeline in einem akademischen Labor
Authors: Wilson Rebecca M. , Danishefsky Samuel J.
Published: July 2010

In dieser Retrospektive erinnern wir an einige ausgewählte Beispiele für die Synergie zwischen der sehr anspruchsvollen chemischen Synthese und der Identifizierung von neuen vielversprechenden Wirkstoff‐Kandidaten als potenzielle Pharmazeutika. Die Weiterentwicklung von oft niedermolekularen Zielverbindungen zu solchen, deren Größe normalerweise mit biologischen Wirkstoffen assoziiert ist, wird ebenfalls dargelegt.
Preclinical and clinical investigation of a CCR5 antagonist, AZD5672, in patients with rheumatoid arthritis receiving methotrexate
Authors: Gerlag Daniëlle M. , Hollis Sally , Layton Mark , Vencovský Jiří , Szekanecz Zoltán , Braddock Martin , Tak Paul P. ,   ESCAPE Study Group
Published: July 2010

Objective

To investigate both the preclinical effects of blocking the chemokine receptor CCR5 and the clinical effects of this approach on the signs and symptoms of rheumatoid arthritis (RA) in patients with active disease.

Methods

Preclinical evaluations of AZD5672, a small‐molecule antagonist of CCR5, were performed, including studies of ligand binding and chemotaxis. The pharmacokinetics of AZD5672 were assessed in both single‐ and multiple‐dose studies in healthy volunteers. A randomized, placebo‐controlled, phase IIb study was conducted in patients with active RA receiving methotrexate. Treatment arms were AZD5672 (20, 50, 100, or 150 mg orally, once daily), matched placebo, or open‐label etanercept (50 mg subcutaneously, once weekly). The primary end point was the proportion of patients achieving a 20% improvement response on the American College of Rheumatology improvement criteria (ACR20) at week 12. Secondary end points included the ACR20 over time, as well as 50% (ACR50) and 70% (ACR70) improvement responses, changes in individual components of the ACR improvement criteria, and disease activity measured with the Disease Activity Score based on the 28‐joint count.

Results

AZD5672 was a highly potent and selective antagonist of CCR5, displaying nonproportional steady‐state pharmacokinetics while inhibiting internalization of CCR5 in an ex vivo macrophage inflammatory protein 1β stimulation assay in which AZD5672 was evaluated over the 20–150‐mg dose range. In the phase IIb study testing this dose range in patients with RA (n = 371 patients randomized to received treatment), AZD5672 was generally well tolerated, with no unexpected adverse events. There was no statistically significant difference in the proportion of patients achieving an ACR20 response at week 12 between those receiving any dose of AZD5672 and those receiving placebo; etanercept was significantly more efficacious than AZD5672 and placebo.

Conclusion

Despite a clear rationale for targeting CCR5, this clinical study showed that AZD5672, administered orally, did not have any clinical benefit, suggesting that CCR5 antagonism alone is unlikely to be a viable therapeutic strategy in RA.
S100A8 causes a shift toward expression of activatory Fcγ receptors on macrophages via toll‐like receptor 4 and regulates Fcγ receptor expression in synovium during chronic experimental arthritis
Authors: van Lent Peter L. , Grevers Lilyanne C. , Schelbergen Rik , Blom Arjen , Geurts Jeroen , Sloetjes Annet , Vogl Thomas , Roth Johannes , van den Berg Wim B.
Published: July 2010

Objective

The levels of both Fcγ receptor (FcγR) and the alarmins S100A8 and S100A9 are correlated with the development and progression of cartilage destruction during antigen‐induced arthritis (AIA). This study was undertaken to study the active involvement of S100A8, S100A9, and S100A8/S100A9 in FcγR regulation in murine macrophages and synovium during AIA.

Methods

Recombinant murine S100A8 (rS100A8) was injected into normal mouse knee joints, and the synovium was isolated for analysis of FcγR messenger RNA (mRNA) expression by reverse transcription–polymerase chain reaction (RT‐PCR). Macrophages, including bone marrow macrophages derived from Toll‐like receptor 4–deficient (TLR‐4−/−) mice, and polymorphonuclear cells (PMNs) were stimulated with S100 proteins, and levels of FcγR mRNA and protein were measured using RT‐PCR and fluorescence‐activated cell sorting analyses. AIA was induced in the knee joints of S100A9‐deficient (S100A9−/−) mice, compared with wild‐type (WT) controls, and the extent of cartilage destruction was determined using immunohistochemical analysis.

Results

Intraarticular injection of rS100A8 into the knee joints of normal mice caused a strong up‐regulation of mRNA levels of activating FcγRI (64‐fold increase) and FcγRIV (256‐fold increase) in the synovium. Stimulation of macrophages with rS100A8 led to significant up‐regulation of mRNA and protein levels of FcγRI and FcγRIV, but not FcγRIII, while the effects of S100A9 or S100A8/S100A9 complexes were less potent. Stimulation of PMNs (32Dcl3 cell line) with S100 proteins had no effect on FcγR expression. Up‐regulation of FcγRI and FcγRIV was abrogated in rS100A8‐stimulated macrophages from TLR‐4−/− mice, indicating that the induction of FcγR expression by S100A8 is mediated by TLR‐4. FcγR expression in the inflamed synovium of S100A9−/− mice was significantly lower on day 14 after arthritis induction when compared with WT controls, and these findings correlated with reduced severity of matrix metalloproteinase–mediated cartilage destruction.

Conclusion

S100A8 is a strong promoter of activating FcγRI and FcγRIV in macrophages through the activation of TLR‐4, and acts as a regulator of FcγR expression in inflamed synovium in chronic experimental arthritis.
Sustained T cell Rap1 signaling is protective in the collagen‐induced arthritis model of rheumatoid arthritis
Authors: Abreu Joana R. F. , Krausz Sarah , Dontje Wendy , Grabiec Aleksander M. , de Launay Daphne , Nolte Martijn A. , Tak Paul P. , Reedquist Kris A.
Published: July 2010

Objective

Defective activation of T cell receptor–proximal signaling proteins, such as the small GTPase Rap1, is thought to contribute to the pathologic behavior of rheumatoid arthritis (RA) synovial T cells. This study was undertaken to determine whether maintaining Rap1 signaling in murine T cells modifies disease onset or severity in collagen‐induced arthritis (CIA).

Methods

CIA experiments were conducted using wild‐type and RapV12‐transgenic mice, which express an active mutant of Rap1 in the T cell compartment. Mice were assessed using macroscopic, microscopic, and radiologic measures, and serum levels of anticollagen antibodies were measured by enzyme‐linked immunosorbent assay. Phenotypic and functional characterization of wild‐type and RapV12‐transgenic T cells under homeostatic conditions and during disease onset was performed by flow cytometry.

Results

Disease incidence and severity, synovial infiltration, joint destruction, and anticollagen antibody production were significantly reduced in RapV12‐transgenic mice. Although the numbers and percentages of CD3+, CD4+, and CD8+ (naive, effector, and memory) T cells, Treg cells, and Th17 cells were equivalent in wild‐type and RapV12‐transgenic mice, a significant decrease in the percentage of tumor necrosis factor α–secreting CD8+ T cells was observed in RapV12‐transgenic mice during CIA. RapV12‐transgenic T cells also inefficiently expressed inducible costimulator and CD40L costimulatory proteins involved in B cell immunoglobulin class switching.

Conclusion

Our findings indicate that maintenance of T cell Rap1 signaling in murine T cells reduces disease incidence and severity in CIA, which are associated with specific defects in T cell effector function. Therefore, the restoration of Rap1 function in RA synovial T cells may have therapeutic benefit in RA.
Biologic similarities based on age at onset in oligoarticular and polyarticular subtypes of juvenile idiopathic arthritis
Authors: Barnes Michael G. , Grom Alexei A. , Thompson Susan D. , Griffin Thomas A. , Luyrink Lorie K. , Colbert Robert A. , Glass David N.
Published: July 2010

Objective

To explore biologic correlates to age at onset in patients with juvenile idiopathic arthritis (JIA) using peripheral blood mononuclear cell (PBMC) gene expression analysis.

Methods

PBMCs were isolated from 56 healthy controls and 104 patients with recent‐onset JIA (39 with persistent oligoarticular JIA, 45 with rheumatoid factor–negative polyarticular JIA, and 20 with systemic JIA). RNA was amplified and labeled using NuGEN Ovation, and gene expression was assessed with Affymetrix HG‐U133 Plus 2.0 GeneChips.

Results

A total of 832 probe sets revealed gene expression differences (false discovery rate 5%) in PBMCs from children with oligoarticular JIA whose disease began before age 6 years (early‐onset disease) compared with those whose disease began at or after age 6 years (late‐onset disease). In patients with early‐onset disease, there was greater expression of genes related to B cells and less expression of genes related to cells of the myeloid lineage. Support vector machine analyses identified samples from patients with early‐ or late‐onset oligoarticular JIA (with 97% accuracy) or from patients with early‐ or late‐onset polyarticular JIA (with 89% accuracy), but not from patients with systemic JIA or healthy controls. Principal components analysis showed that age at onset was the major classifier of samples from patients with oligoarticular JIA and patients with polyarticular JIA.

Conclusion

PBMC gene expression analysis reveals biologic differences between patients with early‐and late‐onset JIA, independent of classification based on the number of joints involved. These data suggest that age at onset may be an important parameter to consider in JIA classification. Furthermore, pathologic mechanisms may vary with age at onset, and understanding these processes may lead to improved treatment of JIA.
No evidence of association between anti–tumor necrosis factor treatment and mortality in patients with rheumatoid arthritis: Results from the British Society for Rheumatology Biologics Register
Authors: Lunt Mark , Watson Kath D. , Dixon William G. ,   British Society for Rheumatology Biologics Register Control Centre Consortium, Symmons Deborah P. M. , Hyrich Kimme L. ,   British Society for Rheumatology Biologics Register
Published: July 2010

Objective

To study the association between anti–tumor necrosis factor (anti‐TNF) therapy and mortality in a national cohort of patients with rheumatoid arthritis.

Methods

We prospectively followed up 12,672 patients who were beginning anti‐TNF therapy and 3,522 biologic‐naive patients receiving disease‐modifying antirheumatic drugs (DMARDs) until either July 31, 2008, or death, whichever occurred first. Notification of death and cause of death was received from the UK National Death Register. Mortality was compared using Cox proportional hazards models. Inverse probability of treatment weighting was used to adjust for the confounding effects of baseline differences between groups, including age, sex, disease severity, disability, and comorbidity. Missing baseline data were accounted for using multiple imputation.

Results

When compared with the DMARD cohort, the anti‐TNF cohort was younger (median age 57 years versus 61 years), had greater disease activity (median Disease Activity Score in 28 joints 6.6 versus 5.1), and had greater disability (median Health Assessment Questionnaire score 2.1 versus 1.6). Patients in the DMARD cohort were more likely to have a history of myocardial infarction (4.8% versus 3.1%) and chronic obstructive pulmonary disease (8.1% versus 4.8%) but were less likely to have had depression (16.5% versus 18.9%). There were 9,445 and 50,803 person‐years of followup in the DMARD and anti‐TNF cohorts, respectively, during which time 204 DMARD‐treated and 856 anti‐TNF–treated patients died. The weighted mortality hazard ratios in the anti‐TNF cohort were as follows: all‐cause 0.86 (95% confidence interval [95% CI] 0.64–1.16), circulatory disease 0.73 (95% CI 0.44–1.23), neoplasm 0.65 (95% CI 0.39–1.09), and respiratory disease 0.81 (95% CI 0.36–1.83).

Conclusion

Our results indicate that, compared with standard DMARD therapy, treatment with anti‐TNF therapies was not associated with an increase in mortality.