bluuebunny/crossref_metadata_2025 huggingface dataset:
Resistencia química del hormigón. XIX. Acción de una disolución saturada de yeso: influencia de la adición de escoria a un cemento Portland. Evolución de las resistencias mecánicas a flexotracción y de los coeficientes de corrosión
Authors: Gaspar-Tebar Demetrio , Sagrera-Moreno José Luis
Published: July 2012

In the present paper, third of the new series started with and industrial portland cement, there is studied the influence exerted by the addition of different quantities of slag to an industrial portand cement (cement 3 < > P-450) in its chemical-resistant behavior when subjected, during various periods of time, to the action of a saturated dissolution of gypsum determining the evolution of the chemical resistance by the Koch-Steinegger method, as well as the mechanical resistances to flexotraction of mortar specimens (1:3) of 1 X 1 X 6 cm manufactured with the cement 3 and with the mixtures cement 3/slag = 85/15, 65/35, 40/60 and 30/70 in weight, sinking in filtered potable water a series of twelve (12) specimens and in a saturated dissolution of gypsum similar to the previous one, during 56-90-180 and 360 days, after having cured them during twenty four (24) hours in an enclosure saturated of humidity at 20 ± 2°C and, following, twenty one (21) days under filtered potable water.
In this work there has been shown the favorable action that, from a mechanical-resistant point of view, is exerted by the addition of slag, in a special manner, of high quantities, to cement 3.
Resistencia química del hormigón. XXI. Influencia de la adición de escoria a un cemento portland de alta resistencia inicial. Estudio de la concentración iónica del sistema cemento 1/escoria-agua potable filtrada
Authors: Sagrera-Moreno José Luis , Gaspar-Tebar Demetrio
Published: July 2012

In the present work, a continuation of others, there is studied the variation of the pH, and likewise the concentration of the ions Ca (II) and SO4 (II) of the means (filtered potable water) in which there have been submerged the test tube series of mortar (1:3) made with an industrial Portland cement of high initial resistance (cement 1 P-550-ARI) and with the cement mixtures 1/slag = 85/15 - 65/35 - 40/60 and 30/70, in weight, submerged during the curing period (21 days) and later during 56-90-180 and 360 days (conservation periods), in this stage. There is likewise studied the chemical composition of the new solid phases formed in said means. The structural composition of said solid phases (calcite) was determined by DRX, and account of this was given in (2).
In the different cases studied it was demonstrated that an increase of the content of Ca (II) is produced in the dissolution and in the solid phases mentioned, and likewise of the value of the pH, which depends on the mixture utilized to manufacture the different test tube series and on the time of conservation. The Ca (II) found in the dissolution (filtered potable water) is less than 0,1 X 10-2 mols (in the majority of cases it is less than 0,07 X 10-2 mols) while in the new solid phase it is greater (normally, greater than 0,3 X 10-2 mols).
On the contrary, the ion SO4 (II) has not been detected in the solid phases mentioned, being found in small quantities in the different liquid phases (filtered potable water); less than 0,08 X 10-2 mols in the majority of the cases.
Método para la formulación de hormigones de fibras metálicas
Authors: Serna Ros Pedro
Published: July 2012

In the work we are presenting, we have set ourselves the target of determining a practical method for ascertaining the dosage of fibrous concrete. To do this, as in any problem regarding dosage, we shall start from the possibilities of supply, which will be conditioned by the nature of the aggregates to be used, of certain technical restrictions imposed by the admixtures and of the carrying out requirements which will set the concrete workability.
The first part of our study amounts to determining the optimal percentages for each aggregate and the water-cement ratio, starting with the dosage of cement established initially and for each fibre content proposed.
In the second part, we shall develop the study of acceptable limits of fibre content, in order to prevent 'balls of fibre' from forming.
Retracción de pastas de cemento en estado plástico y en la primera etapa de endurecimiento
Authors: Ossa M. Mauricio , Marcantonini M. Claudio , Cofre, H. Favio
Published: July 2012

A great deal of information exists on the retraction occurring in pastes, mortars and concrete, twenty-four hours after being mixed; we have very little information, however, concerning the volumetric changes which take place in a shorter period of time, this being mainly due to the difficulties which arise in measuring these volumetric variations.
The authors of this experimental work have been concerned with measuring the short-term changes in volume which take place in cement pastes, that is to say, in periods of less than twenty-four hours, although they have taken measurements for periods of up to three days.
Experiments have been carried out on microsamples of 10 X 10 X 40 mm manufactured using the pressing method and kept throughout the measuring period in an isothermic non-aggressive atmosphere. Research has been carried out on four types of cement made up of clinkers of different composition and admixtures of pozzolana or scoria for blast furnaces.
Radioactividad natural en materiales de construcción
Authors: Baró J. , Fernández A. , Cusido J. A. , Isalgue A.
Published: July 2012

Some materials usually employed in building edification have been analyzed for their radioactive contents. The specific activities of all the gamma rays emisors present in fourteen differents samples have been determined. In all the cases, only low activities (under 2 Bq/g) have been found for these samples collected from the surroundings of Barcelona.
Metales orgánicos. Una perspectiva de nuevos materiales
Authors: Ballester Manuel
Published: July 2012

This work explains with comprehensive terms for non specialists what the Organic Metals are ("coductive plastics"). Those new materials will be in the near future a true revolution on several technology fields.
Determinación de trazas de Molibdeno (VI), Níquel (II) y Vanadio (V) en cementos por polarografía diferencial de impulsos
Authors: Cobo-Guzmán Antonio , Gallego-Andreu Rafael , Gaspar-Tebar Demetrio
Published: July 2012

In this work an account is given of the results obtained when the differential pulse polarography (differential pulse anodic stripping voltametry) is applied to the determination of the contents of the compounds by molybdenum (VI), nickel (II) and vanadium (V) in a common portland cement which are in quantities of the order of p.p.m.
Those studies show that it is not possible to determine simultaneaously the content of the three mentioned ions in the cement, but if working in acid medium (hydrochloridric and sulphuric), in ammoniacal or cyanided medium and in basic medium (produced by NaHCO3) polagrogrammes are obtained which allow to complete those mentioned determinations of Mo (VI) in the first medium, of Ni (II) in the second and of V(V) in the third. Because of the high sensibility of the polarography it is possible to determine the Ni (II) which is found in quantities from 2.9 to 3.4 p.p.m. (0.0002g to 0.00034 %, in mass).
Estudio de la aptitud de un material como adición activa al cemento
Authors: De Luxán M. Pilar , Sánchez de Rojas M. Isabel
Published: July 2012

The study of the suitability of a material for its use as an active addition to the cement and, really, the evaluation of its puzzolanic capacity is a problem which is frecuently present.
In this work, a line of behaviour to approach this problem is explained in a practical and definite way, pointing methods of possible application, while there is not a normative about the matter.
(GEHO) Grupo español del hormigón
Authors: Editorial Equipo
Published: July 2012

The European Concrete Board (CEB) was founded in 1957 for the purpose of developing at an international level the study of any scientific and technical subject which might further building in concrete. Among its six founding members was the Spanish professor Eduardo Torroja.
From then onwards, the CEB's prestige has continuously increased thanks to the accomplished works and publications. On the other hand, since 1976 when its Statutes were reformed the CEB has been named Euro-International Concrete Board, therefore admitting any country in the world. At present their member countries are more than fourty.
In Spain, the relation with the CEB has been traditionally accomplished through the "Eduardo Torroja Institute of Construction and Cement" (lETcc), belonging to the High Council of Scientific Research, through which technical and administrative relations were centralized. This Institute’s mission has proved very effective and has directly or indirectly favoured a great number of Spanish experts and professionals in the building sector. In particular the Spanish technical regulation of the concrete sector is based on the CEB's works.
The increasing development of the concrete technique in our country, in its different aspects of research, teaching, projects, calculations, construction, quality control, etc., has furthered the number of professionals who are interested in the CEB. Therefore it is advisable to create an Association, according to the law of December 24th 1964, which should channel all activities deriving from membership of the CEB, thus promoting the Spanish experts’ participation in such a prestigious organization.
The present Statutes meet this idea of participation. With respect to the Additional Provisions, they constitute an acknowledgement of the main role played in the subject by the Eduardo Torroja Institute and mark as well a path for future evolution.
The Spanish Concrete Group legalization process was completed by its inscription at the Madrid Provincial Registry of Associations, N.P. 6.771 of July 4th 1985.
Acción del agua de mar sobre un cemento portland de alta resistencia inicial y sobre un cemento portland resistente a los sulfatos: influencia de la adición de escoria. Estudio de la concentración iónica
Authors: Gaspar-Tébar Demetrio , Sagrera-Moreno José Luis
Published: July 2012

Not available
Acción del agua de mar sobre un cemento portland de alta resistencia inicial, sobre un cemento portland resistente a los sulfatos y sobre un cemento portland: influencia de la adición de escoria. Estudio por DRX
Authors: Gaspar-Tébar Demetrio , Sagrera-Moreno José Luis
Published: July 2012

Not available
Simultaneous Determination of Sitagliptin and Metformin in Pharmaceutical Preparations by Capillary Zone Electrophoresis and its Application to Human Plasma Analysis
Authors: Salim Mohamed , El-Enany Nahed , Belal Fathallah , Walash Mohamed , Patonay Gabor
Published: July 2012

A novel, quick, reliable and simple capillary zone electrophoresis CZE method was developed and validated for the simultaneous determination of sitagliptin (SG) and metformin (MF) in pharmaceutical preparations. Separation was carried out in fused silica capillary (50.0 cm total length and 43.0 cm effective length, 49 μm i.d.) by applying a potential of 15 KV (positive polarity) and a running buffer containing 60 mM phosphate buffer at pH 4.0 with UV detection at 203 nm. The samples were injected hydrodynamically for 3 s at 0.5 psi and the temperature of the capillary cartridge was kept at 25°C. Phenformin was used as internal standard (IS).

The method was suitably validated with respect to specificity, linearity, limit of detection and quantitation, accuracy, precision, and robustness. The method showed good linearity in the ranges of 10-100 μg/mL and 50-500 μg/mL with limits of detection of 0.49, 2.11 μm/mL and limits of quantification of 1.48, 6.39 μg/mL for SG and MF, respectively. The proposed method was successfully applied for the analysis of the studied drugs in their synthetic mixtures and co-formulated tablets without interfering peaks due to the excipients present in the pharmaceutical tablets. The method was further extended to the in-vitro determination of the two drugs in spiked human plasma. The estimated amounts of SG/MF were almost identical with the certified values, and their percentage relative standard deviation values (% R.S.D.) were found to be ≤1.50% (n = 3). The results were compared to a reference method reported in the literature and no significant difference was found statistically.
New particle growth and shrinkage observed in subtropical environments
Authors: Young L.-H. , Lee S.-H. , Kanawade V. , Hsiao T.-C. , Lee Y. L. , Hwang B.-F. , Liou Y.-J. , Hsu H.-T. , Tsai P.-J.
Published: July 2012

Abstract. We present the first systematic analysis for new particle formation (NPF), growth and shrinkage of new particles observed at four different sites in subtropical Central Taiwan. A total of 14 NPF events were identified during 137 days of ambient measurements during a cold and warm season. The derived nucleation rates of 1 nm particles (J1) and growth rates were in the range of 39.6–252.9 cm−3 s−1 and 6.5–14.5 nm h−1, respectively. The NPF events occurred on days either with low condensation sink (CS), increased morning traffic emissions and the breakup of nocturnal inversion layer (type A), or with high CS, minimum levels of primary traffic emissions and enhanced atmospheric dilution (type B). On non-event days, the particle number concentrations were mostly driven by traffic emissions. We have also observed shrinkage of new particles (type A-S and B-S), reversal of growth, during five out of the 14 NPF events. In intense shrinkage cases, the grown particles shrank back to the smallest measurable size of ~10 nm, thereby creating a unique "arch-like" shape in the size distribution contour plot. The particle shrinkage rates ranged from 5.1 to 7.6 nm h−1. The ratios of shrinkage-to-growth rates were mostly in the range of 0.40–0.65, suggesting that a large fraction of the condensable species that contributed to growth were likely semi-volatile. The particle shrinkage was related to air masses with low CS due to atmospheric dilution, high ambient temperature and low relative humidity and such atmospheric conditions may have facilitated the evaporation of semi-volatile species from the particles to the gas phase. Our observations show that the new particle growth may be a~reversible process and the evaporating semi-volatile species are important for the growth of new particles to cloud condensation nuclei sizes.
Little Ice Age climate and oceanic conditions of the Ross Sea, Antarctica from a coastal ice core record
Authors: Rhodes R. H. , Bertler N. A. N. , Baker J. A. , Steen-Larsen H. C. , Sneed S. B. , Morgenstern U. , Johnsen S. J.
Published: July 2012

Abstract. Increasing paleoclimatic evidence suggests that the Little Ice Age (LIA) was a global climate change event. Understanding the forcings and associated climate system feedbacks of the LIA is made difficult by the scarcity of Southern Hemisphere paleoclimate records. We use a new glaciochemical record of a coastal ice core from Mt. Erebus Saddle, Antarctica, to reconstruct atmospheric and oceanic conditions in the Ross Sea sector of Antarctica over the past five centuries. The LIA is identified in stable isotope (δD) and lithophile element records, which respectively demonstrate that the region experienced 1.6 ± 1.4 °C cooler average temperatures prior to 1850 AD than during the last 150 yr and strong (>57 m s−1) prevailing katabatic winds between 1500 and 1800 AD. Al and Ti concentration increases of an order of magnitude (>120 ppb Al) are linked to enhanced aeolian transport of complex silicate minerals and represent the strongest katabatic wind events of the LIA. These events are associated with three 12–30 yr intervals of cooler temperatures at ca. 1690 AD, 1770 AD and 1840 AD. Furthermore, ice core concentrations of the biogenic sulphur species MS− suggest that biological productivity in the Ross Sea polynya was ~80% higher prior to 1875 AD than at any subsequent time. We propose that cooler Antarctic temperatures promoted stronger katabatic winds across the Ross Ice Shelf, resulting in an enlarged Ross Sea polynya during the LIA.
The Rock Geochemical Model (RokGeM) v0.9
Authors: Colbourn G. , Ridgwell A. , Lenton T. M.
Published: July 2012

Abstract. A new model of terrestrial rock weathering – The Rock Geochemical Model (RokGeM) – is developed for incorporation into the GENIE Earth System modelling framework. In this paper we describe the model. We consider a range of previously devised parameterizations, ranging from simple dependencies on global mean temperature following (Berner et al., 1983), to spatially-explicit dependencies on runoff and temperature (GKWM; Bluth and Kump, 1994; GEM-CO2 Amiotte-Suchet et al., 2003) – fields provided by the energy-moisture balance atmosphere model component in GENIE. Using long term carbon cycle perturbation experiments, we test the effects of a wide range of model parameters, including: whether or not the atmosphere was "short-circuited" in the carbon cycle; the sensitivity and feedback strength of temperature and runoff on carbonate and silicate weathering; different river-routing schemes; 0-D (global average) vs. 2-D (spatially explicit) weathering schemes; and the lithology dependence of weathering. Included are details of how to run the model and visualize the results.
Mapping spatially-temporally continuous shortwave albedo for global land surface from MODIS data
Authors: Liu N. , Liu Q. , Wang L. , Liang S. , Wen J. , Qu Y. , Liu S.
Published: July 2012

Abstract. Land-surface albedo plays a critical role in the Earth's radiant energy budget studies. Satellite remote sensing is an effective approach to acquire regional and global albedo observations. However, owing to cloud coverage, seasonal snow and sensor malfunctions, spatially-temporally continuous albedo datasets are often inaccessible. GLASS preliminary albedo datasets (GLASS02A2x, x = 1, 2, 3 and 4) are newly developed global daily land-surface albedo products. Like other products, GLASS02A2x albedo surfers from large areas of missing data. Beside this, sharp fluctuations exist in GLASS02A2x time series due to data noise and algorithm uncertainties. In this study, a statistics-based temporal filterer (STF) is proposed to fill the data gaps and smooth the fluctuations in GLASS02A2x albedo time series. The result of STF algorithm is the GLASS final albedo product (GLASS02A06). Results show that the STF method has greatly improved the integrity and smoothness of the GLASS final albedo product. Seasonal trends in albedo are well depicted by the GLASS final albedo product. Compared with MODIS product, the final GLASS albedo product is much more competent in capturing the surface albedo variations. Although the STF algorithm is designed for GLASS albedo product, it is able to incorporate other albedo products. The STF method may also be applied to other parameters, such as the LAI and soil moisture.
Iatrogenic False Aneurysms. A Rare Complication of Hip Surgery
Authors: Garrido-Gómez Juan , Garrido-Gómez Maria N. , Arrabal-Polo Miguel A. , Garrido-Pareja Fermin , Linares-Palomino Jose P.
Published: July 2012

The purpose of this study was to determine the incidence of arterial false aneurysms following hip surgery diagnosed and treated in our hospital between January 1995 and January 2010. We conducted a retrospective analysis of all patients undergoing hip surgery (osteosynthesis, hemi-arthroplasty, total arthroplasty, or revision arthroplasty) under our care. To determine the incidence of arterial false aneurysm, we identified patients with abnormal bleeding through the surgical wound postoperatively.

Out of the 11,839 patients undergoing hip surgery during the study period, 321 had abnormal bleeding that aroused suspicion of an associated vascular lesion. Among these, the presence of a false aneurysm requiring specific treatment was confirmed in eight patients.

False aneurysms are a rare and occasionally severe complication of hip surgery that typically manifest with significant haemorrhage during the postoperative period. The management of these lesions by interventional radiology is associated with few complications and permits rapid patient stabilisation and early recovery, avoiding more aggressive and sometimes fruitless surgical exploration.
A Combination Method of Mixed Multiscale Finite-Element and Laplace Transform for Flow in a Dual-Permeability System
Authors: Liu Tang-Wei , Xu He-Hua , Qiu Xue-Lin
Published: July 2012

An efficient combination method of Laplace transform and mixed multiscale finite-element method for coupling partial differential equations of flow in a dual-permeability system is present. First, the time terms of parabolic equation with unknown pressure term are removed by the Laplace transform. Then the transformed equations are solved by mixed FEMs which can provide the numerical approximation formulas for pressure and velocity at the same time. With some assumptions, the multiscale basis functions are constructed by utilizing the effects of fine-scale heterogeneities through basis functions formulation computed from local flow problems. Without time step in discrete process, the present method is efficient when solving spatial discrete problems. At last, the associated pressure transform is inverted by the method of numerical inversion of the Laplace transform.
On Pointlike Interaction between Three Particles: Two Fermions and Another Particle
Authors: Minlos Robert Adol'fovich
Published: July 2012

The problem of construction of self-adjoint Hamiltonian for quantum system consisting of three pointlike interacting particles (two fermions with mass 1 plus a particle of another nature with mass m>0) was studied in many works. In most of these works, a family of one-parametric symmetrical operators {Hε,ε∈ℝ1} is considered as such Hamiltonians. In addition, the question about the self-adjointness of Hε is equivalent to the one concerning the self-adjointness of some auxiliary operators {𝒯l,l=0,1,…} acting in the space L2(ℝ+1,r2dr). In this work, we establish a simple general criterion of self-adjointness for operators 𝒯l and apply it to the cases l=0 and l=1. It turns out that the operator 𝒯l=0 is self-adjoint for any m, while the operator 𝒯l=1 is self-adjoint for m>m0, where the value of m0 is given explicitly in the paper.
A Review of the Ethnobotany and Pharmacological Importance ofAlstonia booneiDe Wild (Apocynaceae)
Authors: Adotey John Prosper Kwaku , Adukpo Genevieve Etornam , Opoku Boahen Yaw , Armah Frederick Ato
Published: July 2012

Alstonia booneiDe Wild is a herbal medicinal plant of West African origin, popularly known as God's tree or “Onyame dua”. Within West Africa, it is considered as sacred in some forest communities; consequently the plant parts are not eaten. The plant parts have been traditionally used for its antimalarial, aphrodisiac, antidiabetic, antimicrobial, and antipyretic activities, which have also been proved scientifically. The plant parts are rich in various bioactive compounds such as echitamidine, Nα-formylechitamidine, boonein, loganin, lupeol, ursolic acid, andβ-amyrin among which the alkaloids and triterpenoids form a major portion. The present paper aims at investigating the main research undertaken on the plant in order to provide sufficient baseline information for future work and for commercial exploitation.
Thyroid and Hepatic Haemodynamic Alterations among Egyptian Children with Liver Cirrhosis
Authors: El-Kabbany Zeinab A. , Hamza Rasha T. , Abd El Hakim Ahmed S. , Tawfik Lamis M.
Published: July 2012

Background. Alterations in thyroid hormones regulation and metabolism are frequently observed in patients with cirrhosis. Aims. To assess alterations in thyroid volume (TV), haemodynamics, and hormones in patients with cirrhosis and their relation to hepatic arterial haemodynamics, and disease severity. Methods. Forty cirrhotic patients were compared to 30 healthy subjects regarding TV, free triiodiothyronine (fT3), free tetraiodothyronine (fT4), thyroid stimulating hormone (TSH), and pulsatility and resistance indices in the inferior thyroid and hepatic arteries. Results. TV (P=0.042), thyroid volume standard deviation score (TVSDS, P=0.001), Inferior Thyroid Artery Pulsatility Index (ITAPI, P=0.001), Inferior Thyroid Artery Resistance Index (ITARI, P=0.041), Hepatic Artery Pulsatility Index (HAPI, P=0.029) and Hepatic Artery Resistance Index (HARI, P=0.035) were higher among cases being highest in Child-C patients. FT3 was lower in patients than controls (P=0.001) and correlated negatively with ITAPI (r=−0.71, P=0.021) and ITARI (r=−0.79, P=0.011). ITAPI and ITARI correlated directly with HAPI and HARI (r=0.62, P=0.03, and r=0.42, P=0.04, resp.). Conclusions. Thyroid is involved in the haemodynamic alterations of cirrhosis. Routine study of thyroid by Doppler and assessment of thyroid functions should be performed in patients with cirrhosis to offer proper treatment if needed.
Additive Main Effect and Multiplicative Interaction Analysis for Grain Yield of Chickpea (Cicer arietinum L.) in Iran
Authors: Sabaghpour Sayyed Hossain , Razavi Farhang , Fatemeh Danyali Seyyedeh , Tobe Davood , Ebadi Asghar
Published: July 2012

Selection of chickpea (Cicer arietinum L.) cultivars with wide adaptability across diverse farming environments is important before recommending them to achieve a high rate of cultivar adoption. Multienvironment trials including 3 years and 5 locations for 17 genotypes of autumn chickpea were carried out in Iran. Additive main effect and multiplicative interaction (AMMI) were used to understand the GE interaction pattern. Analysis of variance of grain yield showed that 68.36% of the total sum of squares was attributable to environmental effects, only 15.9% to genotypic effects and 13.55% to GE interaction effects. Biplot of the first principal component and mean grain yields for genotypes and environments revealed that high yielding genotypes were not stable cultivars regarding final yield. The AMMI2 mega-environment analysis identified four chickpea megaenvironments in Iran. The first megaenvironment contained locations, Ghachsaran and Lorestan, where genotype Arman was the winner; the second megaenvironment contained locations Gorgan, where genotype FLIP 98-126C was superior. The tertiary megaenvironment contained locations in Ilam, where genotype FLIP 98-82C was superior and the location of Kermanshah made up the other megaenvironment, with FLIP 98-201C as superior.
Impedimetric characterization of human blood using three-electrode based ECIS devices
Authors: Pradhan Rangadhar , Mitra Analava , Das Soumen
Published: July 2012

In this study, three-electrode based electric cell-substrate impedance sensing (ECIS) devices were used to study the electrical properties of blood and its constituents using electrochemical impedance spectroscopy. The three-electrode based ECIS devices were fabricated by using micromachining technology with varying sizes for working, reference and counter electrodes. The blood and its constituents such as serum, plasma, and red blood cells (RBCs) were prepared by conventional methods and stored for impedance measurement using fabricated microdevices. Equivalent circuits for blood, serum, plasma and RBCs were proposed using the software package ZSimpWin to validate the experimental data. The proposed equivalent circuit models of blood and its components have excellent agreement up to a frequency of 1 MHz. It is evident from the experimental results that blood and its components have specific impedance signatures that decrease with the increase of frequency. Blood shows higher impedance than the other samples in the lower frequency range (<50 kHz). It was also found that above 50 kHz, the impedance value of RBCs is nearly the same as whole blood. The impedance of serum and plasma steadily decreases with the increase of frequency up to 100 kHz and flattens out after that. The minimum impedance value achieved for serum and plasma is much less than the value obtained for whole blood.
The Empirical Quest for Normative Meaning: Introduction and Overview
Authors: Frederick William C.
Published: July 2012

MUST the empirical study of business ethics and values stand in the shadow of positivism? If so, does that constrain such studies to normatively sterile descriptions of purported facts? And would the methods thus employed fall short of yielding needed normative perspectives on business decisions that occasionally mean life or death, and even more often affect the quality of life, for those who feel their weight? Are the values and ethical principles that lie behind business actions so elusive, so inaccessible, so imprecise that they must remain forever in the shadowy realm of speculation and commonsense opinion, never to be liberated from positivism’s Gulag?
Editorial Board Thoughts: Doesn't Work
Authors: Cyzyk Mark
Published: July 2012

Editorial Board Thoughts: Doesn't Work
Public Library Computer Waiting Queues: Alternatives to the First-Come-First-Served Strategy
Authors: Williamson Stuart
Published: July 2012

This paper summarizes the results of a simulation of alternative queuing strategies for a public library computer sign-up system.  Using computer usage data gathered from a public library, the performance of these various queuing strategies is compared in terms of the distribution of user wait times.  The consequences of partitioning a pool of public computers are illustrated as are the potential benefits of prioritizing users in the waiting queue according to the amount of computer time they desire.
Mobile Technologies & Academics: Do Students Use Mobile Technologies in Their Academic Lives and are Librarians Ready to Meet this Challenge?
Authors: Dresselhaus Angela , Shrode Flora
Published: July 2012

In this paper we report on two surveys and offer an introductory plan that librarians may use to begin implementing mobile access to selected library databases and services. Results from the first survey helped us to gain insight into where students at Utah State University (USU) in Logan, Utah, stand regarding their use of mobile devices for academic activities in general and their desire for access to library services and resources in particular. A second survey, conducted with librarians, gave us an idea of the extent to which responding libraries offer mobile access, their future plans for mobile implementation, and their opinions about whether and how mobile technologies may be useful to library patrons. In the last segment of the paper, we outline steps librarians can take as they “go mobile.”
Multifunctional Mesoporous Silica Nanoparticles for Cancer‐Targeted and Controlled Drug Delivery
Authors: Zhang Quan , Liu Fang , Nguyen Kim Truc , Ma Xing , Wang Xiaojun , Xing Bengang , Zhao Yanli
Published: July 2012

Multifunctional mesoporous silica nanoparticles are developed in order to deliver anticancer drugs to specific cancer cells in a targeted and controlled manner. The nanoparticle surface is functionalized with amino‐β‐cyclodextrin rings bridged by cleavable disulfide bonds, blocking drugs inside the mesopores of the nanoparticles. Poly(ethylene glycol) polymers, functionalized with an adamantane unit at one end and a folate unit at the other end, are immobilized onto the nanoparticle surface through strong β‐cyclodextrin/adamantane complexation. The non‐cytotoxic nanoparticles containing the folate targeting units are efficiently trapped by folate‐receptor‐rich HeLa cancer cells through receptormmediated endocytosis, while folate‐receptor‐poor human embryonic kidney 293 normal cells show much lower endocytosis towards nanoparticles under the same conditions. The nanoparticles endocytosed by the cancer cells can release loaded doxorubicin into the cells triggered by acidic endosomal pH. After the nanoparticles escape from the endosome and enter into the cytoplasm of cancer cells, the high concentration of glutathione in the cytoplasm can lead to the removal of the β‐cyclodextrin capping rings by cleaving the pre‐installed disulfide bonds, further promoting the release of doxorubicin from the drug carriers. The high drug‐delivery efficacy of the multifunctional nanoparticles is attributed to the co‐operative effects of folate‐mediated targeting and stimuli‐triggered drug release. The present delivery system capable of delivering drugs in a targeted and controlled manner provides a novel platform for the next generation of therapeutics.
Solution‐Processed, Alkali Metal‐Salt‐Doped, Electron‐Transport Layers for High‐Performance Phosphorescent Organic Light‐Emitting Diodes
Authors: Earmme Taeshik , Jenekhe Samson A.
Published: July 2012

High‐performance, blue, phosphorescent organic light‐emitting diodes (PhOLEDs) are achieved by orthogonal solution‐processing of small‐molecule electron‐transport material doped with an alkali metal salt, including cesium carbonate (Cs2CO3) or lithium carbonate (Li2CO3). Blue PhOLEDs with solution‐processed 4,7‐diphenyl‐1,10‐phenanthroline (BPhen) electron‐transport layer (ETL) doped with Cs2CO3 show a luminous efficiency (LE) of 35.1 cd A−1 with an external quantum efficiency (EQE) of 17.9%, which are two‐fold higher efficiency than a BPhen ETL without a dopant. These solution‐processed blue PhOLEDs are much superior compared to devices with vacuum‐deposited BPhen ETL/alkali metal salt cathode interfacial layer. Blue PhOLEDs with solution‐processed 1,3,5‐tris(m‐pyrid‐3‐yl‐phenyl)benzene (TmPyPB) ETL doped with Cs2CO3 have a luminous efficiency of 37.7 cd A−1 with an EQE of 19.0%, which is the best performance observed to date in all‐solution‐processed blue PhOLEDs. The results show that a small‐molecule ETL doped with alkali metal salt can be realized by solution‐processing to enhance overall device performance. The solution‐processed metal salt‐doped ETLs exhibit a unique rough surface morphology that facilitates enhanced charge‐injection and transport in the devices. These results demonstrate that orthogonal solution‐processing of metal salt‐doped electron‐transport materials is a promising strategy for applications in various solution‐processed multilayered organic electronic devices.
Synthesis, Characterization, and Structural Modeling of High‐Capacity, Dual Functioning MnO2 Electrode/Electrocatalysts for Li‐O2 Cells
Authors: Trahey Lynn , Karan Naba K. , Chan Maria K. Y. , Lu Jun , Ren Yang , Greeley Jeffrey , Balasubramanian Mahalingam , Burrell Anthony K. , Curtiss Larry A. , Thackeray Michael M.
Published: July 2012

It has become clear that cycling lithium‐oxygen cells in carbonate electrolytes is impractical, as electrolyte decomposition, triggered by oxygen reduction products, dominates the cell chemistry. This research shows that employing an α‐MnO2/ramsdellite‐MnO2 electrode/electrocatalyst results in the formation of lithium‐oxide‐like discharge products in propylene carbonate, which has been reported to be extremely susceptible to decomposition. X‐ray photoelectron data have shown that what are likely lithium oxides (Li2O2 and Li2O) appear to form and decompose on the air electrode surface, particularly at the MnO2 surface, while Li2CO3 is also formed. By contrast, cells without α‐MnO2/ramsdellite‐MnO2 fail rapidly in electrochemical cycling, likely due to the differences in the discharge product. Relatively high electrode capacities, up to 5000 mAh/g (carbon + electrode/electrocatalyst), have been achieved with non‐optimized air electrodes. Insights into reversible insertion reactions of lithium, lithium peroxide (Li2O2) and lithium oxide (Li2O) in the tunnels of α‐MnO2, and the reaction of lithium with ramsdellite‐MnO2, as determined by first principles density functional theory calculations, are used to provide a possible explanation for some of the observed results. It is speculated that a Li2O‐stabilized and partially‐lithiated electrode component, 0.15Li2O·α‐LixMnO2, that has Mn4+/3+ character may facilitate the Li2O2/Li2O discharge/charge chemistries providing dual electrode/electrocatalyst functionality.
The Impact of the New York State Milk Price Gouging Law on the Price Transmission Process and Supermarket Pricing Strategies in the Fluid Whole Milk Market
Authors: Bolotova Yuliya V. , Novakovic Andrew M.
Published: July 2012

The study analyzes the effect of the New York State Milk Price Gouging Law 200% rule (June 1991–October 2008) on the nature of Class I milk price transmission and supermarket pricing strategies in the fluid whole milk market. This rule established that retail prices of fluid milk products higher than 200% of the Class I milk prices were unconscionably excessive. There is empirical evidence suggesting that supermarket whole milk pricing strategies and the nature of Class I milk price transmission tend to be different in the law period as compared to the period prior to the MPGL enforcement. During the pre‐law period, supermarkets used retail price stabilization practice characterized by an incomplete and asymmetric price transmission. During the law period, supermarkets used marketing margin stabilization practice characterized by more than a complete and a much more symmetric price transmission. The institutional environment affected by the interaction of the analyzed regulatory mechanism and the changes taking place in the economic environment (increasing Class I milk price volatility and increasing concentration in the fluid milk processing and supermarket retailing) was likely to cause the observed changes in the supermarket whole milk pricing strategy and Class I milk price transmission process. [EconLit classifications: C33, C34, D12]. © 2012 Wiley Periodicals, Inc.
Abelian dark matter models for 511 keV γ rays and direct detection
Authors: Cline J.M. , Frey A.R.
Published: July 2012

The authors construct a simple U(1) hidden sector model of metastable dark matter that could explain excess 511 keV gamma rays from the galactic center as observed by INTEGRAL, through inelastic scattering of dark matter followed by its decay. Although the model is highly constrained, it naturally accommodates dark matter with mass and cross section in the range suggested by the CoGeNT and CRESST experiments. The dark gauge boson that mediates the interactions with standard model matter has a mass of several hundred MeV, and might be discovered by heavy photon detection experiments, including APEX, MAMI and HPS.
Characterization and bioactivity evaluation of (starch/N‐vinylpyrrolidone)—hydroxyapatite nanocomposite hydrogels for bone tissue regeneration
Authors: Raafat Amany I. , Saad Eldin Aisha A. , Salama Aida A. , Ali Nashwa S.
Published: July 2012

Hydrogel series composed of starch/N‐vinylpyrrolidone (starch/NVP) have been synthesized by means of γ‐radiation‐induced graft copolymerization and crosslinking process. Optimization of the preparation conditions was achieved to ensure the highest gelation degree. The produced hydrogels were characterized using fourier transform spectroscopy, as well as by studying their swelling behavior. In situdeposition of hydroxyapatite (HAp) was achieved via alternate soaking technique. The developed nanocomposites nHAp‐(starch/NVP) were characterized using energy dispersive X‐ray spectroscopy, thermogravimetric analysis, X‐ray diffraction, scanning electron microscopy. Mechanical study revealed that the compressive strength of the composites increased initially after the first cycle of deposition, then it decreased gradually by increasing the number of the deposition cycles. In vitro bioactivity and blood compatibility evaluation of the obtained nanocomposites indicated that these nanocomposites were both bioactive and biocompatible. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Modeling the hyperviscoelastic behavior of a tire tread compound reinforced by silica and carbon black
Authors: Ghoreishy Mir Hamid Reza , Alimardani Mohammad , Mehrabian Ramin Zafar , Gangali Saeed Taghvaei
Published: July 2012

This research study was devoted to the modeling of the mechanical behavior of three carbon black/silica natural rubber/butadiene rubber (NR/BR) compounds under a tensile load. These compounds were prepared on a two‐roll mill, and the tensile testes were carried out on a dumbbell‐shaped specimen and three rubber‐strip specimens with different widths. Heat buildup tests were also performed, and the temperature rise was determined. The time‐independent behavior of the rubber was described by traditional hyperelastic models, including those of Marlow and Yeoh. The viscoelastic behavior was studied with two linear (Prony series) and nonlinear [Bergstrom–Boyce (BB)] models. A previously developed methodology by the authors, which was based on the finite element modeling of the tension of the rubber strips, was used to determine the parameters of the mentioned equations. It was shown that neglecting the viscoelasticity would have given rise to large errors in predicting the mechanical deformation in the rubbers. However, the linear viscoelastic model failed to predict the correct behavior at a large strain, particularly for wider samples. On the other hand, not only could the combination of the Yeoh hyperelastic model with the BB equation describe the mechanical behavior at low to medium strains, but also the large strains were taken into consideration. Both the linear and nonlinear hyperviscoelastic models accurately described the hysteresis in rubbers, and this could be used for the evaluation of the rolling resistance in tires. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Dual layer structural thermoplastic polyester powder coating film and its weathering resistance
Authors: Takeshita Yukitoshi , Kamisho Takuya , Sakata Seizo , Sawada Takashi , Watanuki Yoshikazu , Nishio Ryuichi , Ueda Toshinobu
Published: July 2012

Micro FTIR analysis was performed to the point with a 50–80 μm spatial resolution to verify the exact structure of a new blend thermoplastic powder coating film. Resistance to certain artificially accelerated conditions and actual outdoor exposure were examined to confirm the performance of the film as a protective coating for use in the telecommunication field. The new blend powder coating film consists of primary polyethylene terephthalate (PET) and secondary polyvinyl butyral (PVB) resins, and has a distinct dual phase structure. Specifically, it forms a continuous PVB phase in a surface layer with a thickness of approximately 100–150 μm. Good corrosion resistance was confirmed in artificially accelerated testing using salt water spray, heat cycle, and accelerated UV tests. Actual outdoor exposure in a metropolitan area (Shinkiba in Tokyo) and a coastal area (Miyake Island) revealed good weathering performance throughout the study period. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Effect of fiber surface treatment of poultry feather fibers on the properties of their polymer matrix composites
Authors: Huda M. S. , Schmidt W. F. , Misra M. , Drzal L. T.
Published: July 2012

This study develops the enabling technology needed to transform the fibers of poultry feather (FPF), a waste product left over after processing poultry in the food processing industry, as reinforcement filler material for manufacturing composite materials. We successfully fabricated composite materials from biopolymers (polylactide, PLA) and FPF that were produced by the extruder system. FPF‐reinforced polypropylene (PP) composites were also compounded and molded and compared to PLA/FPF composite. The composites were evaluated via thermal and mechanical analysis. To enhance the adhesion between the polymer matrix and the FPF, the FPF have been treated with sodium hydroxide, 10% maleinized polybutadiene rubber, and a silane‐coupling agent. X‐ray photoelectron spectroscopy was used to analyze the influence of modifications on the properties of fibers and found that the coupling agent was localized at the surface of the fibers. Thermal behavior of pretreated fibers was also studied by thermogravimetric analysis. All treatments clearly enhanced thermal performance of fibers. This enhancement of fiber properties, along with an improvement in fiber/matrix adhesion, led to improvement in the mechanical properties of the composite materials. It was found that the surface‐treated fiber‐reinforced materials offered superior mechanical properties compared to untreated fiber‐reinforced composite materials. Moreover, morphological studies by the scanning electron microscopy demonstrated that better adhesion between the fiber and the matrix was achieved especially for the surface‐treated fiber‐reinforced composite materials. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Influence of sodium bromide additive on polyethersulfone ultrafiltration membranes
Authors: Noor Nur Diana Mohd , Yusof Noordin Mohd , Ahmed Iqbal , Hesampour Mehrdad , Idris Ani
Published: July 2012

The effect of sodium bromide (NaBr) on performance and characteristics of ultrafiltration (UF) membranes was studied. Asymmetric UF membranes were prepared by phase inversion technique from a multicomponent dope polymer solution consisting of the polymer; polyethersulfone (PES), solvent; N, N‐dimethylformamide (DMF) and NaBr as micromolecular additive. The dissolution of PES‐DMF‐NaBr was carried out using microwave irradiation technique to induce rapid dissolution through minimal heating time. Various concentrations of NaBr were mixed with PES in the range of 1–5 wt % and its influence on membrane characteristics such as surface hydrophilicity was measured by contact angle and the performance in terms of water flux and rejection rates were evaluated using micromolecular test substances. The morphology and streaming potential of PES UF membranes were analyzed using scanning electron microscopy (SEM) and ζ‐potential measurement, respectively. Overall, the results suggest that the membrane consisting of 1 wt % NaBr exhibits the best performance in terms of rejection and flux rates with molecular weight cutoff (MWCO) of 45 kDa and mean pore size of 6 nm. The membrane with the 1 wt % addition of NaBr demonstrates most negative charge which indicates less fouling characteristics and displays approximately three times higher permeation. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Dynamic mechanical properties of polystyrene‐co‐styrenesulfonic acid copolymers neutralized with aliphatic diamines
Authors: Luqman Mohammad , Ko Kwang‐Hwan , Kim Joon‐Seop , Shin Kwanwoo
Published: July 2012

In this article, we reported the effects of the addition of various aliphatic diamines (ADAs) on the dynamic mechanical properties of poly(styrene‐co‐styrenesulfonic acid) copolymers. It was found that the ionic modulus decreased with increasing chain length of ADAs but increased for the ADA12‐containing ionomers. Upon the neutralization of the copolymers with ADAs, a minor change in the size and position of the matrix loss tangent peak was observed. However, the position of the cluster loss tangent peaks shifted to lower temperatures, and the shift rate depended on the chain length of ADAs. Thus, it was suggested that the ADAs acted mainly as preferential plasticizer for the cluster regions. In addition, the effect of the amount of ADA on the difference between the matrix and cluster temperatures of the ionomers was strongest than that of the type of ADA or ion content. The X‐ray peak of ADA12 suggested that the ADA12 acted both as plasticizer and as filler. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Stochastic optimization approach of car value depreciation
Authors: Alshamary Bader , Calin Ovidiu
Published: July 2012

This paper presents a stochastic model for a car's value and its depreciation under random repairs modeled by a Poisson process; the usage functional is defined, and the optimal selling time is estimated. Exact or approximative formulas are provided where possible. The car's value is evaluated as an asset with negative return and paying random normally distributed dividends at stochastic times, which are Erlang distributed. Copyright © 2012 John Wiley & Sons, Ltd.