bluuebunny/crossref_metadata_2025 huggingface dataset:
The transient distributions of nuclear weapon-generated tritium and its decay product 3He in the Mediterranean Sea, 1952–2011, and their oceanographic potential
Authors: Roether W. , Jean-Baptiste P. , Fourré E. , Sültenfuß J.
Published: April 2013

Abstract. We present a comprehensive account of tritium and 3He in the Mediterranean Sea since the appearance of the tritium generated by the atmospheric nuclear-weapon testing in the 1950's and early 1960's, based on essentially all available observations. Tritium in surface waters rose to 20–30 TU in 1964 (TU = 1018 · [3H]/[H]), a factor of about 100 above the natural level, and thereafter declined 30-fold up to 2011. The decline was largely due to radioactive tritium decay, which produced significant amounts of its stable daughter 3He. We present the scheme by which we separate the tritiugenic part of 3He and the part due to release from the sea floor (terrigenic part). We show that the tritiugenic component can be quantified throughout the Mediterranean waters, typically to a ±0.15 TU equivalent, mostly because the terrigenic part is low in 3He. This fact makes the Mediterranean unique in offering a potential for the use of tritiugenic 3He as a tracer. The transient distributions of the two tracers are illustrated by a number of sections spanning the entire sea and relevant features of their distributions are noted. By 2011, the 3He concentrations in the top few hundred meters had become low, in response to the decreasing tritium concentrations combined with a flushing out by the general westward drift of these waters. Tritium-3He ages in Levantine Intermediate Water (LIW) were obtained repeated in time at different locations, defining transit times from the LIW source region east of Rhodes. The ages show an upward trend with the time elapsed since the surface-water tritium maximum, which arises because the repeated observations represent increasingly slower moving parts of the full transit time spectrum of LIW. The transit time dispersion found by this new application of tritium-3He dating is considerable. We find mean transit times of 12 ± 2 yr up to the Strait of Sicily, 18 ± 3 yr up to the Tyrrhenian Sea, and 22 ± 4 yr up into the Western Mediterranean. We furthermore present full Eastern Mediterranean sections of terrigenic 3He and tritium-3He age in 1987, the latter one similarly showing an effect of the transit time dispersion. We conclude that the available tritium and 3He data, in particular if combined with other tracer data, are useful for constraining the subsurface circulation and mixing of the Mediterranean Sea.
Balanced conditions or slight mass gain of glaciers in the Lahaul and Spiti region (northern India, Himalaya) during the nineties preceded recent mass loss
Authors: Vincent C. , Ramanathan Al. , Wagnon P. , Dobhal D. P. , Linda A. , Berthier E. , Sharma P. , Arnaud Y. , Azam M. F. , Jose P. G. , Gardelle J.
Published: April 2013

Abstract. The volume change of the Chhota Shigri Glacier (India, 32° 20 N, 77° 30' E) between 1988 and 2010 has been determined using in situ geodetic measurements. This glacier has experienced only a slight mass loss between 1988 and 2010 (−3.8 ± 2.0 m w.e. (water equivalent) corresponding to −0.17 ± 0.09 m w.e. yr−1). Using satellite digital elevation models (DEM) differencing and field measurements, we measure a negative mass balance (MB) between 1999 and 2010 (−4.8 ± 1.8 m w.e. corresponding to −0.44 ± 0.16 m w.e. yr−1). Thus, we deduce a slightly positive or near-zero MB between 1988 and 1999 (+1.0 ± 2.7 m w.e. corresponding to +0.09 ± 0.24 m w.e. yr−1). Furthermore, satellite DEM differencing reveals that the MB of the Chhota Shigri Glacier (−0.39 ± 0.15 m w.e. yr−1) has been only slightly less negative than the MB of a 2110 km2 glaciarized area in the Lahaul and Spiti region (−0.44 ± 0.09 m w.e. yr−1) during 1999−2011. Hence, we conclude that the ice wastage is probably moderate in this region over the last 22 yr, with near equilibrium conditions during the nineties, and an ice mass loss after. The turning point from balanced to negative mass budget is not known but lies probably in the late nineties and at the latest in 1999. This positive or near-zero MB for Chhota Shigri Glacier (and probably for the surrounding glaciers of the Lahaul and Spiti region) during at least part of the 1990s contrasts with a recent compilation of MB data in the Himalayan range that indicated ice wastage since 1975. However, in agreement with this compilation, we confirm more negative balances since the beginning of the 21st century.
Speman®, A Proprietary Ayurvedic Formulation, Reverses Cyclophosphamide-Induced Oligospermia In Rats.
Authors: Mukram Mohd. Azeemuddin , Rafiq Mohamed , Anturlikar Suryakant D. , Patki Pralhad S.
Published: April 2013

Background: This investigation was aimed to evaluate the effect of Speman®, a well known ayurvedic proprietary preparation, in an experimental model of cyclophosphamide-(CP) induced oligospermia in rats.Materials and Methods: Thirty male rats were randomized in to five, equally-sized groups. Rats in group 1 served as a normal control; group 2 served as an untreated positive control; groups 3, 4, 5 received  Speman® granules  at doses of 300, 600, and 900mg/kg body weight p.o. respectively, once daily for 13 days. On day four, one hour after the respective treatment, oligospermia was induced by administering a single dose of CP (100mg/kg body weight p.o.)  to all the groups except group1. At the end of the study period the rats were euthanised and accessory reproductive organs were weighed and subjected to histopathological examination. The semen samples were subject to enumeration of sperms.  Weight of the reproductive organs, histopathological examination of the tissues, and sperm count were the parameters studied to understand the effect of Speman® on rats with CP-induced oligospermia.Results: Changes that occurred due to the administration of CP at a dose of 100 mg/kg body weight were dose dependently reversed with Speman® at a dose of 300, 600, and 900 mg/kg body weight. There was a statistically significant increase in sperm count and the weight of the seminal vesicle, epididymis, and prostate.Conclusion: Findings of this investigation indicate that Speman® dose dependently reversed the CP-induced derangement of various parameters pertaining to the reproductive system.  This could explain the total beneficial actions of Speman® reported in several other clinical trials.
Extraordinary Weapons, Heroic Ethics, and Royal Justice in Early Irish Literature
Authors: Sayers William
Published: April 2013

The synthesis of pagan and Christian cosmologies that informs medieval Irish letters incorporates prestigious and extraordinary weapons, and other such objects into an all-compassing Nature, in which they are preferentially associated with the themes of heroic ethics, legitimate and just royal rule, and the removal of errant rulers through a cosmic deployment of the “instruments of their fate.” Yet only rhetorical effects of literary depiction raise such weapons to a status approximating the preternatural.
Specific Form and Poisonous Properties:
Authors: Gibbs Frederick W.
Published: April 2013

As a result of the availability of new and exotic drugs and a diversifying medical profession to serve burgeoning towns, some late thirteenth-century physicians began to inquire more explicitly about the difference between a medicine and a poison. Were some substances simply too dangerous to be used in general medical practice? That medical authorities had never agreed on a single definition of poison complicated progress on this front. Fifteenth-century physicians brought significantly new energy to bear on this question through a rigorous examination of the properties of poison and the extent to which it was defined and thought to operate by some kind of occult virtue. Fifteenth-century writing about poison thus provides an important new and early site for examining the historical development of occult influence, because the notion of specific form had become integral to poison's definition and its ontological status as a category of substance. These discussions were instrumental to the development of modern toxicology as well, as it helped further distinguish between the classical notion of pharmaka, in which no substance was singled out as uniquely different in kind from other substances, and that of venenum, which was increasingly defined as fundamentally harmful to the human body.
Nonperformance Variables as Predictors of Marching Band Contest Results
Authors: Rickels David A.
Published: April 2013

The purpose of this study was to examine potential relationships between nonperformance variables and the scoring results of marching band contests in the United States. The term nonperformance variable refers to a characteristic of a competing marching band or its director that was not overtly evaluated by performance scoring criteria at a contest. Using an online questionnaire, data were collected from marching band directors whose bands participated in contests in six randomly selected states (n = 218). Results of a stepwise multiple regression analysis indicated five significant models predicting 50.0% of the variance in contest scores. The significant predictor variables included the size of the marching band; the number of uncertified paid assistant instructors; a scale of the director’s attitudes toward marching band and competition; the hours of weekly rehearsal; and the dollar budget of the marching band. These results carry implications for participants and administrators of band contests, and suggest the need for additional study of marching band competition assessments.
Marketing turístico: Estudo sobre o uso da tecnologia da informação e comunicação nas agências de viagens e turismo de Balneário Camboriú (SC, Brasil)
Authors: Flores Luiz Carlos da Silva , Cavalcante Leila de Sena , Raye Roberta Leal
Published: April 2013

As tecnologias de informação e comunicação (TIC) vêm interferindo significativamente no mercado em um cenário cada vez mais competitivo. No setor de serviços, por conta da sua intangibilidade, a qualidade da comunicação com todos os agentes ligados de forma direta às organizações faz toda a diferença para o sucesso empresarial. O setor de agenciamento no turismo vem se adaptando aos novos instrumentos de TIC. Esse estudo buscou investigar, a partir de uma pesquisa descritiva de abordagem quantitativa, o nível de utilização da tecnologia da informação e comunicação (TIC) de algumas agências de viagens e turismo da cidade de Balneário Camboriú (SC, Brasil) em seu relacionamento com clientes, fornecedores e parceiros, assim como na comercialização dos seus produtos e serviços e nas suas estratégias promocionais. Como procedimentos metodológicos, adotou-se a pesquisa bibliográfica e a pesquisa de campo, que consistiu na aplicação de questionários junto a agentes de viagens e turismo locais. Os resultados demonstraram que ferramentas como o e-mail ainda tem o mesmo nível de utilização que a telefonia fixa e móvel e as redes sociais aparecem com destaque apenas no relacionamento com os clientes. Acredita-se que uma pesquisa qualitativa com os consumidores possa contribuir para uma melhor compreensão acerca da utilização das ferramentas de TIC pelas agências de viagens e turismo.
Nuevos destinos / productos de turismo para la región de Valparaíso, Chile. Las nuevas rutas de turismo para la Reserva de la Biósfera La Campana - Peñuelas
Authors: Figueroa Sterquel Rodrigo , Negrete Sepulveda Jorge , Fuenzalida Díaz Manuel
Published: April 2013

Producto de la globalización y de la metropolización, la demanda por espacios naturales es cada vez más importante, tanto por su explotación económica, su urbanización y/o su valorización socio-ambiental. Por lo tanto, la gestión de los espacios naturales requiere de una mirada territorial multiescalar que favorezca una multifuncionalidad que integre los intereses de los distintos actores. Es lo que estamos desarrollando en el marco del Proyecto Innova CORFO Nº 08CTU01-08 ”Nuevos Destinos/Productos de Turismo de Naturaleza y de Intereses Especiales para la Región de Valparaíso, Chile”, ejecutado por la Pontificia Universidad Católica de Valparaíso, durante el período 2008 - 2012. La aplicación del paradigma decisional multicriterio ha abierto una interesante vía metodológica al tratamiento de la problemática del Ordenamiento Territorial, determinando los lugares más idóneos para la localización de actividades/servicios para el turismo de naturaleza y rural. El modelo de análisis territorial con SIG aplicado, ha permitido cuantificar el territorio en grados de aptitud para el Turismo, que permitiría consolidar una oferta, menos sensible a la estacionalidad y ayudar a posicionar a la Reserva de la Biósfera (MAB) La Campana – Lago Peñuelas como un destino turístico emergente. Esto orienta la caracterización del destino turístico MaB y facilita co-diseñar y co-construir nuevos productos turísticos en función de las capacidades de uso de los territorios y de las aspiraciones locales, apoyando los planes de gestión de las Reservas MaB para que aseguren a las poblaciones, un desarrollo más sostenible.
Os muitos olhares sobre o conceito de hotel boutique
Authors: Angeli Ricardo Barbosa , Torres Ricardo de Gil , Maranhão Ricardo Frota de Albuquerque
Published: April 2013

O mercado hoteleiro investe com regularidade na renovação de seus empreendimentos. Neste momento de melhoria de suas instalações se apresenta uma oportunidade de reposicionamento mercadológico. O presente artigo apresenta uma pesquisa de caráter exploratório, que teve como objetivo geral verificar como o conceito de hotel boutique é entendido por pesquisadores de diferentes países. Em função da maior agilidade para a implantação de inovações, considerou-se a possibilidade do modelo de hotel boutique ser adotado por hotéis independentes como forma de melhorar sua competitividade em relação às grandes redes hoteleiras. Verificou-se que não existe um modelo único de hotel boutique, embora instalações de pequeno porte com design diferenciado e atendimento personalizado sejam uma constante nas descrições em que também é enfatizado o valor da experiência única.
Mass Transport in Ion‐Exchange Membranes
Authors: Tanaka Yoshinobu
Published: April 2013

Irreversible thermodynamics is the fundamental principle that expresses the mass transport across ion‐exchange membranes. The overall mass transport equation is developed with electrodialysis experiments and applied to discuss the performance of an electrodialyzsis process. The computer simulation program is developed using fundamental principles of electrodialysis. Performance of saline water desalination is computed by inputting electrodialyzer specifications and operating conditions. Mechanism of concentration polarization is discussed based on the mass transport across a boundary layer formed on an ion‐exchange membrane. Mechanism of the water dissociation reaction is discussed based on electric potential generated by ion‐exchange groups in the membrane.
Pore Blocking Models
Authors: Ho Chia‐Chi
Published: April 2013

Colloids and particles accumulating on membrane surfaces and/or in the membrane pores cause fouling, which results in a reduction in flux or an increase in transmembrane pressure for constant‐pressure and constant‐flux filtration operations, respectively. Traditionally, membrane fouling is described by one of the following classical models: pore blockage, pore constriction, and cake filtration. In this article, models describing flux decline during constant‐pressure filtration are reviewed. The focus is on flux decline analysis typically used to determine fouling mechanisms and the application of the models accounting for backtransport, deposit layer properties, and membrane morphology.
Thin‐Film Ceramic Membranes
Authors: Yacou Christelle , Wang David , Motuzas Julius , Zhang Xiwang , Smart Simon , Diniz da Costa João C.
Published: April 2013

Ceramic membranes have undergone a concerted research development in the past two decades, since their initial development for uranium isotope processing for the nuclear industry in 1940s. The diversity of inorganic materials, such as ceramics, metals, and nonpolymeric carbons, has allowed researchers to build membranes by a number of processes ranging from simple sol‐gel dip coating to chemical vapor deposition and complex plasma coatings among many others. This article specifically covers all the major preparation methods currently employed in the preparation of thin‐film ceramic membranes derived from silica, zeolites, titania, hierarchical structures, and perovkites.
Photocatalytic Ceramic Membranes
Authors: Zakersalehi Abolfazl , Choi Hyeok , Andersen Joel , Dionysiou Dionysios D.
Published: April 2013

Semiconducting materials, in particular titanium dioxide (TiO2), under ultraviolet (UV) radiation are capable of producing highly reactive species, such as hydroxyl radicals, which readily and nonselectively oxidize and decompose organic pollutants in water. Such inorganic materials can be designed and fabricated in the form of water‐permeable membranes to combine the chemical decomposition of water contaminants with their concurrent physical separation, which is the conceptual basis for photocatalytic ceramic membranes (PCMs). The chemical function of PCMs can also induce water detoxification and disinfection, as well as antifouling action. The multiple actions of PCMs make them attractive for sustainable and versatile water treatment. Recently, progress in novel synthetic chemistry and fabrication routes for innovative PCMs, especially through nanotechnological approaches, has overcome some technical drawbacks of PCMs. This article provides an introduction to PCMs with emphasis on current advances in their fabrication and functionalization. Based on semiconducting TiO2materials under UV radiation, a concise description about the mechanism of photocatalytic reactions is presented, and the multiple functions of TiO2PCMs are overviewed. Some innovative fabrication approaches for PCMs, including the structural and compositional manipulation of monolith and composite TiO2membranes, are also described. Finally, the technical and economic limitations of PCMs and their prospects are briefly discussed.
Surface Modification of Membranes
Authors: Fang Yan , Xu Zhi‐Kang , Wu Jian
Published: April 2013

Surface modification of membranes has become a key issue in membrane science and technology. The major aim of surface modification is improving the performance of the membranes with a view to altering a wide range of characteristics of the surface, such as roughness, surface energy, surface charge, hydrophilicity, biocompatibility, and functionality. Based on these characteristics, the modification methods can be divided into two groups: (i) physical modification (polishing and grinding, thermal treatment, solvent post‐treatment, blending, and coating) and (ii) chemical modification (chemical procedures, plasma treatment, ultraviolet induced grafting, ozone treatment, high energy radiation, and enzymatic treatment). Although each method has its own advantages and limitations, interesting results can be obtained for the modified membranes in the form of improved properties. The modified membranes open the door to further development of membrane technology.
Dynamic Crossflow Filtration
Authors: Jaffrin Michel Y.
Published: April 2013

Dynamic crossflow filtration increases membrane performance through the use of membrane shear rates that are much higher than in conventional crossflow filtration. The production of these high shear rates requires specific modules with metal disks or rotors rotating at high speed near fixed membranes or rotating or vibrating membranes. The advantages and drawbacks of dynamic crossflow filtration will be discussed and currently available pilots and industrial dynamic filtration modules will be described. Specific methods for calculating the shear rate at membranes, which is the key factor governing permeate flux, will be presented for various types of modules. Recent applications of dynamic filtration published in the scientific literature, together with industrial case studies and comparisons with conventional crossflow will be reviewed.

These systems can be advantageous for end‐of‐pipe treatment when the goal is to maximize retentate concentration in order to reach at least 65% of solid concentration. In pharmaceutical and biotechnological applications, where a high purity is required, the higher membrane selectivity of dynamic filtration (better solute transmission in microfiltration and higher microsolute rejection in nanofiltration and reverse osmosis) is an important asset.

Industrial strategies of manufacturers of modules, New Logic Research (CA, USA), which has sold over 376 industrial vibrating modules; Bokela (Germany), which produces the rotating disk Dyno filter; and Metso Paper (Finland), which sells the Optifilter with rotors between, will be summarized.
Electro‐Membrane Processes
Authors: Singh Ajay K. , Shahi Vinod K.
Published: April 2013

Electromembrane processes are well‐established techniques for the production of potable water from brackish water. During recent years, these processes have witnessed penetration into many areas such as energy production, food processing, personal care products, healthcare, production of high quality water, biomolecules separation, sensors, organic separation, industrial effluent treatment, etc. In this article, the principle of the electromembrane process is described along with its advantages and limitations for various applications. Recent developments in ion‐exchange membranes and their utilization in various areas are also described briefly.
Polymer Membranes for Fuel Cells
Authors: Wycisk Ryszard , Ballengee Jason , Pintauro Peter N.
Published: April 2013

Polymeric membranes are a key component of hydrogen/air and direct methanol fuel cells. The desired properties of fuel cell membranes are (i) high proton conductivity, (ii) high mechanical strength, (iii) good oxidative and thermal stability, (iv) low fuel and oxidant permeability, and (v) low cost. The most important and most widely studied membrane polymers include perfluorosulfonic acids (PFSAs), poly(arylene ether)s, polyimides, polyphosphazenes, and polybenzimidazole. Membranes are fabricated via melt extrusion and, most frequently, by solution casting. Composite membranes offer improved mechanical strength and higher temperature stability. Typically, composite membranes are obtained by pore filling, layer‐by‐layer assembly, and electrospinning. The list of current fuel cell membrane manufacturers is relatively short. Most notable is E.I. DuPont de Nemours and Co., which sells PFSA membranes under the trade name Nafion®. Other manufacturers are Solvay Solexis, FuMA‐Tech, BASF, Tokuyama, and Asahi Kasei Chemical Corporation.
CO2Capture
Authors: He Xuezhong , Yu Qiang , Hägg May‐Britt
Published: April 2013

Global warming is becoming a world‐challenging issue related to the emission of greenhouse gases, mainly from CO2. A lot of effort has been put on reduction of CO2emission from large CO2point sources such as fossil fuel power plants and other industries. Membrane technology has already been used in selected gas separation processes such as air separation, natural gas sweetening, biogas upgrading, and hydrogen production during the last two decades, and can be potentially used for CO2capture due to its energy‐efficient and low cost. In this article, a brief review of membrane materials (organic and inorganic) and their properties (physical, chemical, thermal, mechanical stability, and gas separation performance) is provided, and then the main directions of industrial applications of CO2capture using membrane systems are also surveyed. The challenges of membrane systems used for CO2capture are discussed to document that process design and pretreatment are very important for membrane unit operations. Moreover, the process feasibility for CO2capture using different membranes was evaluated by process simulation, economic cost estimation and comparison with traditional amine‐based absorption method in some specific applications.
Natural Gas Purification
Authors: Lin Haiqing , White Lloyd S. , Lokhandwala Kaaeid , Baker Richard W.
Published: April 2013

Since the installation of the first membrane system for CO2removal in the early 1980s, membrane separation has become a proven technology for natural gas purification, such as the removal of carbon dioxide, hydrogen sulfide, heavy hydrocarbons, and nitrogen. Membrane systems can perform the bulk removal of impurities or produce pipeline natural gas. Today, large membrane plants can process up to 1 billion standard cubic feet of natural gas per day (scfd) for CO2removal. This article outlines the advantages of and challenges to membrane processes for natural gas purification, and provides an overview of the advancement in membrane materials, membrane structure, membrane separation performance, module configuration, and process designs for natural gas purification. Furthermore, this article reviews the current commercial membrane systems installed in natural gas processing plants, providing theory and literature references relevant to commercially practiced technology, as well as case design studies derived from actual industrial installations.
Membrane Contactors
Authors: Criscuoli Alessandra
Published: April 2013

This article gives a general outline on membrane contactors, providing basic information on how these systems work, the unit operations that they can cover, the membranes used, the main advantages and disadvantages with respect to conventional devices, as well as the most studied applications. The aspects of these membrane operations that still need to be improved for enlarging and consolidating their areas of application are also reported. The goal is to furnish a general knowledge on the subject, underlining potentialities, problems, and research trends in the field.
Application of Membranes in Biotechnology
Authors: Ghosh Raja
Published: April 2013

Membranes are widely used in biotechnology with the main applications being focused around bioproduct purification. Membranes are also used for laboratory filtration and analysis as components of membrane bioreactors, for biomedical applications such as dialysis and blood oxygenation, and for drug delivery. This article reviews the application of membranes in biological separation processes. The membranes techniques commonly used in these applications are microfiltration, ultrafiltration, and membrane chromatography. This article first reviews the common features and then discusses them individually, highlighting working principles and specific applications.
Membrane‐Based Treatment of Textile Industry Wastewaters
Authors: Koyuncu Ismail , Güney Kenan
Published: April 2013

Textile industry is distinguished from other industries by using a great variety of chemicals and large water consumption. As the cost of freshwater increases and the regulations become stringent, the need for reuse of textile effluents is growing enormously. In this article, membrane‐based treatments of textile industry wastewater is discussed. First, characteristics of textile industry wastewater are given. Then, treatment scenarios at different points of the industry are explained. Nanofiltration (NF) and reverse osmosis (RO) separation processes with/without ultrafiltration (UF) pretreatment are investigated in detail for segregated streams. It is observed that segregated water reuse concept has more advantages than the end‐of‐pipe treatment by means of water volume reused and chemicals recycled.
Individual and National Level Associations Between Economic Deprivation and Partner Violence Among College Students in 31 National Settings
Authors: Sabina Chiara
Published: April 2013

This study expands previous work by examining individual and national level effects of economic deprivation on partner violence among college students. Three main hypotheses were tested: (1) individual level economic deprivation (i.e., ability to meet daily needs and family income) is associated with partner violence, (2) gross national income is associated with the mean rates of partner violence across nations, and (3) the association between individual level economic deprivation and partner violence varies according to the economic national context as measured by gross national income. Data for 14,090 participants from 31 nations came from the International Dating Violence Study that queried university students about violence in their relationships and relevant risk factors. A series of overdispersed Poisson hierarchical linear regression models were specified to test the hypotheses. Ability to meet daily needs, but not family income, was associated with rates of partner violence. Gross national income was also associated with mean rates of partner violence across nations as well as the relationships between ability to meet daily and partner violence and between family income and partner violence. The findings show the importance of context, as indicated by national economic standing, on rates of partner violence. Not only do economically deprived individuals experience more partner violence, but those living in poorer nations experience more partner violence, regardless of individual economic deprivation. Limitations of the study include a non‐random sample and substantial variation in the study sites beyond economic standing. Nonetheless, findings indicate efforts to confront partner violence must also call for cross‐national economic development. Aggr. Behav. 39:247–256, 2013. © 2013 Wiley Periodicals, Inc.
Improvement of Ultrasonically Welded Aluminum/Carbon Fiber Reinforced Polymer‐Joints by Surface Technology and High Resolution Analysis
Authors: Balle Frank , Emrich Stefan , Wagner Guntram , Eifler Dietmar , Brodyanski Alexander , Kopnarski Michael
Published: April 2013

In order to achieve a more specific knowledge about the bonding mechanism of ultrasonically welded Al/CFRP‐joints, microscopic investigations were carried out. Transmission electron microscopy was used to investigate the interface between the aluminum and the CFRP sheet. One important result was the detection of mechanically deformed areas due to ultrasonic welding which lead to a reorientation of the crystal structure in surface near areas of mechanically pre‐treated aluminum. Furthermore it has been proven, that molten thermoplastic can penetrate into a cavernous, nanoscaled aluminum oxide layer, which was generated due to acidic etching of aluminum prior to ultrasonic welding. Because of the fact that hybrid joints with such chemically pre‐treated aluminum parts show most favorable strengths in comparative terms within single lap shear tests, there are clear indications, that in case of CF‐PA66 surface enlargement due to higher roughness is not the reason for this behavior. Instead of this, the sub‐microscopic interlocking of polymer and metal based on the generation of sub‐microscopic fine, porous, and open aluminum oxide structures is the key to improve the mechanical properties of ultrasonically welded Al/CFRP‐joints.
Preparation and characterization of surface modified silicon carbide/polystyrene nanocomposites
Authors: Cao Jian‐Ping , Zhao Jun , Zhao Xiaodong , Hu Guo‐Hua , Dang Zhi‐Min
Published: April 2013

A simple method is reported to coat silicon carbide (SiC) nanoparticles with polystyrene (PS) to improve the interfacial adhesion between polymer matrix and SiC nanoparticles. The morphology of untreated SiC nanoparticles, PS coated SiC (p‐SiC) nanoparticles, SiC/PS nanocomposites, and p‐SiC/PS nanocomposites are observed. The HRTEM image of p‐SiC shows that the thickness of PS on the surface of SiC is about 1.5–2.0 nm, which is consistent with the TGA results. With 24.7 vol % untreated SiC nanoparticles dispersed into PS matrix, the thermal conductivity (λ) of the SiC/PS composites increases by about 192%. However, when the same volume fraction of p‐SiC nanoparticles is used, the increase is about 353%. This big difference could be attributed to the promoted dispersion of the p‐SiC in the PS matrix. The measurements of glass transition (Tg), dielectric constant (ε), and tensile strength at break (σb) also support this explanation. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Influence of the mixing time on the phase structure and glass‐transition behavior of poly(ethylene terephthalate)/poly(ethylene‐2,6‐naphthalate) blends
Authors: Tao Wang , Wei Wu , Yu Chen , Ren Wu , Qiaoling Luo
Published: April 2013

Blends of poly(ethylene terephthalate) and poly(ethylene‐2,6‐naphthalate) (70 : 30 w/w) were prepared via a melt‐mixing process at 280°C with various mixing times. The melt‐mixed blends were analyzed by magnetic resonance spectroscopy, differential scanning calorimetry, dynamic mechanical measurements, transmission electron microscopy, and tensile tests. The results indicate that the blends mixed for short times had lower extents of transesterification and were miscible to a limited extent. The blends initially show two glass transitions, which approached more closely and merged gradually with increasing mixing time. A mechanical model was used to help understand the glass‐transition behavior. With increasing mixing time, the phase structure of the blends improved, and this led to an increase in the tensile strength. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Preparation of UV reactive montmorillonite and characterization of its nanocomposites with poly(vinyl alcohol)
Authors: Schauberger Jörg Guido , Riess Gisbert , Kern Wolfgang
Published: April 2013

A cation‐exchanged montmorillonite clay is prepared as filler material with high dispersibility, that should act as Fe3+‐donor for photochemical crosslinking of PVA/Fe3+‐MMT materials with filler contents of up to 50 wt % with regard to the polymer matrix. Hence, no organic photoinitiators and hazardous compounds are utilized. This material may be considered environmentally benign and could be applied in the field of food packaging or for biomedical applications. Upon UV exposure of liquid PVA/Fe3+‐MMT dispersion samples, a significant change of the refractive index is determined and the absorption at 360 nm decreased. This indicates the transition of Fe3+ to Fe2+, which initiates a radical crosslinking mechanism. A homogenous distribution and parallel orientation of the modified clay particles is revealed by SEM measurements. The solubility behavior of the PVA/Fe3+‐MMT composite materials in deionized water, changes considerably due to the high filler content and UV‐induced crosslinking, resulting in gel contents exceeding 90 wt %. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Epoxy resin composites with surface‐modified silicon dioxide nanoparticles: A review
Authors: Sprenger Stephan
Published: April 2013

Surface‐modified silica nanoparticles, 20 nm in size and with a very narrow particle size distribution, have been available as concentrates in epoxy resins in industrial quantities for the last 10 years. They can be used in epoxy resin formulations to improve many different properties, including the strength, modulus, toughness, and fatigue performance. In this review, I examine the literature published in the last decade, compare the results with a focus on the mechanical properties, and discuss the mechanisms responsible for property improvements. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1421–1428, 2013
Periconceptional paternal smoking and the risk of congenital heart defects: A case‐control study
Authors: Deng Kui , Liu Zhen , Lin Yuan , Mu Dezhi , Chen Xinlin , Li Jun , Li Nana , Deng Ying , Li Xiaohong , Wang Yanping , Li Shengli , Zhu Jun
Published: April 2013

Background

Maternal smoking during pregnancy has been consistently associated with an increased risk of congenital heart defects (CHDs). However, few studies have reported the association between paternal smoking during pregnancy and CHDs among offspring. This report presents the first case‐control study to investigate the possible association between periconceptional paternal smoking and CHDs in China.

Methods

From February 2010 through October 2011, 284 case fetuses with nonsyndromic CHDs and 422 control fetuses with no birth defects were recruited. The mothers of cases and controls were interviewed regarding whether the fathers of fetuses smoked and avoided the mothers while smoking during the periconceptional period. An unconditional logistic regression was used to calculate the adjusted odds ratios (AORs) and 95% confidence intervals (CIs) while controlling for potential confounders.

RESULTS

Light paternal smoking increased the risk of isolated conotruncal heart defects (AOR, 2.23; 95% CI, 1.05, 4.73). Medium paternal smoking seemed to be associated with septal defects (AOR, 2.04; 95% CI, 1.05, 3.98) and left ventricular outflow tract obstructions (AOR, 2.48; 95% CI, 1.04, 5.95). Heavy paternal smoking was also associated with isolated conotruncal heart defects (AOR, 8.16; 95% CI, 1.13, 58.84) and left ventricular outflow tract obstructions (AOR, 13.12; 95% CI, 2.55, 67.39). Paternal smoking with no avoidance behavior was associated with an increased risk of these CHDs subtypes.

CONCLUSIONS

Periconceptional paternal smoking increased the risk of isolated conotruncal heart defects, septal defects and left ventricular outflow tract obstructions. The avoidance behavior of paternal smokers may decrease the risk of selected CHDs.Birth Defects Research (Part A) 97:210–216, 2013. © 2013 Wiley Periodicals, Inc.
Commonality in Down and fetal alcohol syndromes
Authors: Solzak Jeffrey P. , Liang Yun , Zhou Feng C. , Roper Randall J.
Published: April 2013

BACKGROUND

Down syndrome (DS) and Fetal Alcohol Syndrome (FAS) are two leading causes of birth defects with phenotypes ranging from craniofacial abnormalities to cognitive impairment. Despite different origins, we report that in addition to sharing many phenotypes, DS and FAS may have common underlying mechanisms of development.

METHODS

Literature was surveyed for DS and FAS as well as mouse models. Gene expression and apoptosis were compared in embryonic mouse models of DS and FAS by qPCR, immunohistochemical and immunoflurorescence analyses. The craniometry was examined using MicroCT at postnatal day 21.

RESULTS

A literature survey revealed over 20 comparable craniofacial and structural deficits in both humans with DS and FAS and corresponding mouse models. Similar phenotypes were experimentally found in pre‐ and postnatal craniofacial and neurological tissues of DS and FAS mice. Dysregulation of two genes, Dyrk1a and Rcan1, key to craniofacial and neurological precursors of DS, was shared in craniofacial precursors of DS and FAS embryos. Increased cleaved caspase 3 expression was also discovered in comparable regions of the craniofacial and brain precursors of DS and FAS embryos. Further mechanistic studies suggested overexpression of trisomic Ttc3 in DS embyros may influence nuclear pAkt localization and cell survival.

CONCLUSIONS

This first and initial study indicates that DS and FAS share common dysmorphologies in humans and animal models. This work also suggests common mechanisms at cellular and molecular levels that are disrupted by trisomy or alcohol consumption during pregnancy and lead to craniofacial and neurological phenotypes associated with DS or FAS. Birth Defects Research (Part A) 97:187–197, 2013. © 2013 Wiley Periodicals, Inc.
Panel forum on multiple comparison procedures: A commentary from a complex trial design and analysis plan
Authors: Wang Sue‐Jane , Bretz Frank , Dmitrienko Alex , Hsu Jason , Hung H. M. James , Huque Mohammad , Koch Gary
Published: April 2013

Motivated by a complex study design aiming at a definitive evidential setting, a panel forum among academia, industry, and US regulatory statistical scientists was held at the 7th International Conference on Multiple Comparison Procedures (MCP) to comment on the multiplicity problem. It is well accepted that studywise or familywise, type I error rate control is the norm for confirmatory trials. But, it is an uncharted territory regarding the criteria beyond a single confirmatory trial. The case example describes a Phase III program consisting of two placebo‐controlled multiregional clinical trials identical in design intended to support registration for treatment of a chronic condition in the lung. The case presents a sophisticated multiplicity problem in several levels: four primary endpoints, two doses, two studies, two regions with different regulatory requirements, one major protocol amendment on the original statistical analysis plan, which the panelists had a chance to study before the forum took place. There were differences in professional perspectives among the panelists laid out by sections. Nonetheless, irrespective of the amendment, it may be arguable whether the two studies are poolable for the analysis of two primary endpoints prespecified. How should the study finding be reported in a scientific journal if one health authority approves while the other does not? It is tempting to address the Phase III program level multiplicity motivated by the increasing complexity of the partial hypotheses framework posed that are across studies. A novel thinking of the MCP procedures beyond individual‐study level (studywise or familywise as predefined) and across multiple‐study level (experimentwise and sometimes programwise) will become an important research problem expected to face with scientific and regulatory challenges.
Confidence intervals for confirmatory adaptive two‐stage designs with treatment selection
Authors: Bebu Ionut , Dragalin Vladimir , Luta George
Published: April 2013

The construction of adequate confidence intervals for adaptive two‐stage designs remains an area of ongoing research. We propose a conditional likelihood‐based approach to construct a Wald confidence interval and two confidence intervals based on inverting the likelihood ratio test, one of them using first‐order inference methods and the second one using higher order inference methods. The coverage probabilities of these confidence intervals, and also the average bias and mean square error of the corresponding point estimates, compare favorably with other available techniques. A small simulation study is used to evaluate the performance of the new methods. We investigate other extensions of practical interest for normal endpoints and illustrate them using real data, including the selection of more than one treatment for the second stage, selection rules based on both efficacy and safety endpoints, and the inclusion of a control/placebo arm. The new method also allows adjustment for covariates, and has been extended to deal with binomial data and other distributions from the exponential family. Although conceptually simple, the new methods have a much wider scope than the methods currently available.
Confidence intervals for the selected population in randomized trials that adapt the population enrolled
Authors: Rosenblum Michael
Published: April 2013

It is a challenge to design randomized trials when it is suspected that a treatment may benefit only certain subsets of the target population. In such situations, trial designs have been proposed that modify the population enrolled based on an interim analysis, in a preplanned manner. For example, if there is early evidence during the trial that the treatment only benefits a certain subset of the population, enrollment may then be restricted to this subset. At the end of such a trial, it is desirable to draw inferences about the selected population. We focus on constructing confidence intervals for the average treatment effect in the selected population. Confidence interval methods that fail to account for the adaptive nature of the design may fail to have the desired coverage probability. We provide a new procedure for constructing confidence intervals having at least 95% coverage probability, uniformly over a large class of possible data generating distributions. Our method involves computing the minimum factor c by which a standard confidence interval must be expanded in order to have, asymptotically, at least 95% coverage probability, uniformly over . Computing the expansion factor c is not trivial, since it is not a priori clear, for a given decision rule, for which data generating distribution leads to the worst‐case coverage probability. We give an algorithm that computes c, and then prove an optimality property for the resulting confidence interval procedure.
Smooth ROC curves and surfaces for markers subject to a limit of detection using monotone natural cubic splines
Authors: Bantis Leonidas E. , Tsimikas John V. , Georgiou Stelios D.
Published: April 2013

The use of ROC curves in evaluating a continuous or ordinal biomarker for the discrimination of two populations is commonplace. However, in many settings, marker measurements above or below a certain value cannot be obtained. In this paper, we study the construction of a smooth ROC curve (or surface in the case of three populations) when there is a lower or upper limit of detection. We propose the use of spline models that incorporate monotonicity constraints for the cumulative hazard function of the marker distribution. The proposed technique is computationally stable and simulation results showed a satisfactory performance. Other observed covariates can be also accommodated by this spline‐based approach.
Combination therapy with gefitinib and doxorubicin inhibits tumor growth in transgenic mice with adrenal neuroblastoma
Authors: Kawano Kumi , Hattori Yoshiyuki , Iwakura Hiroshi , Akamizu Takashi , Maitani Yoshie
Published: April 2013

Highly relevant mouse models of human neuroblastoma (NB) are needed to evaluate new therapeutic strategies against NB. In this study, we characterized transgenic mice with bilateral adrenal tumors. On the basis of information from the tumoral gene expression profiles, we examined the antitumor effects of unencapsulated and liposomal doxorubicin (DXR), alone and in combination with gefitinib, on adrenal NB. We showed that intravenous injection of unencapsulated or liposomal DXR alone inhibited tumor growth in a dose‐dependent manner, as assessed by magnetic resonance imaging (MRI). However, liposomal DXR did not exhibit greater antitumor effect than unencapsulated DXR. Immunohistochemical analysis revealed that the adrenal tumor vasculature with abundant pericyte coverage was a less leaky structure for liposomes. Combination therapy with unencapsulated or liposomal DXR plus gefitinib strongly suppressed tumor growth and delayed tumor regrowth than treatment with unencapsulated or liposomal DXR alone, even at a lower dose of DXR. Dynamic contrast‐enhanced MRI analysis revealed that gefitinib treatment increased blood flow in the tumor, indicating that gefitinib treatment changes the tumor vascular environment in a manner that may increase the antitumor effect of DXR. In conclusion, the combination of gefitinib and DXR induces growth inhibition of adrenal NBs in transgenic mice. These findings will provide helpful insights into new treatments for NB.
Simultaneous Production of Biodiesel and Free Lutein from Chlorella vulgaris
Authors: Prommuak C. , Pavasant P. , Quitain A. T. , Goto M. , Shotipruk A.
Published: April 2013

Biodiesel and valuable free lutein were demonstrated to be simultaneously produced from Chlorella vulgaris lipid extracts. The alkali catalyst used in the transesterification of triglycerides acted as a reactant in converting lutein fatty acid esters to free lutein. A maximum biodiesel yield of 33.6 % by weight of the algal lipids was obtained after a 4‐h reaction with MeOH at the MeOH/biomass ratio of 16:1 using 6 % alkali catalyst. The excess of alkali and MeOH employed in the production of biodiesel ensured the complete saponification of all lutein fatty acid esters to free lutein, giving a maximum yield of 2.3 % by weight of the algal lipids. In addition, a process for the separation of the biodiesel and free lutein products from the reaction mixture is proposed. Finally, a preliminary economic assessment was conducted, the results of which suggest that the process for the simultaneous production of biodiesel and lutein from C. vulgaris may be economically feasible.