bluuebunny/crossref_metadata_2025 huggingface dataset:
Micromachined Devices for Use in Terahertz Applications
Authors: Wood David , Chamberlain Martyn , Baragwanath Adam , Dodd Linzi , Hill Carlo , Gallant Andrew J.
Published: September 2012

Here we present results from key aspects of our interest in using micromachined devices in the THz region. First, our early work on making filters from rods of gold-coated SU8 is described. Pass (up to 97%) and stop bands can be observed which are theoretically underpinned by both FDTD and complex band structure simulations. Second, there is a discussion of how THz radiation passes through two-dimensional periodic arrays of subwavelength apertures. In particular, the geometry of the arrays has been studied with time-domain spectroscopy. A time-of-flight model is presented which can be used to provide insight into the operation of these arrays and has implications for the optimum design of THz plasmonic sensors. Finally, we report the THz ‘super’ extraordinary transmission properties of an optimised hybrid subwavelength aperture array, surrounded by subwavelength grooves.
Rectilinear Electrothermal Actuator Using High-Aspect-Ratio Micromachined Composite of SU-8 and Silicon
Authors: Thubthimthong Borriboon , Lau Gih Keong , Vadakke Matham Murukeshan
Published: September 2012

A precisely rectilinear electrothermal actuator integrated with highly thermally expandable micromachined composites of SU-8 and silicon is presented. The actuator is capable of producing a maximum output rectilinear displacement of 42 μm with an estimated blocked force of up to 61 mN. The actuator operates at a low temperature rise of less than 266 °C and at input voltage of less than 15 V. Thermal time constant of the actuator is measured to be less than 3 ms. Such a powerful and power-efficient actuator could benefits future devices in optical MEMS.
Integrated Microsystems
Authors: Esashi Masayoshi , Tanaka Shuji
Published: September 2012

Technology called MEMS (Micro Electro Mechanical Systems) or microsystems are heterogeneous integration on silicon chips and play important roles as sensors. MEMS as switches and resonators fabricated on LSI are needed for future multi-band wireless systems. MEMS for safety systems as event driven tactile sensor network for nursing robot are developed. Wafer level packaging for MEMS and open collaboration to reduce the cost for the development are discussed.
RF-MEMS Components and Networks for High-Performance Reconfigurable Telecommunication and Wireless Systems
Authors: Iannacci Jacopo , Resta Giuseppe , Farinelli Paola , Sorrentino Roberto
Published: September 2012

MEMS (MicroElectroMechanical-Systems) technology applied to the field of Radio Frequency systems (i.e. RF-MEMS) has emerged in the last 10-15 years as a valuable and viable solution to manufacture low-cost and very high-performance passive components, like variable capacitors, inductors and micro-relays, as well as complex networks, like tunable filters, reconfigurable impedance matching networks and phase shifters, and so on. The availability of such components and their integration within RF systems (e.g. radio transceivers, radars, satellites, etc.) enables boosting the characteristics and performance of telecommunication systems, addressing for instance a significant increase of their reconfigurability. The benefits resulting from the employment of RF-MEMS technology are paramount, being some of them the reduction of hardware redundancy and power consumption, along with the operability of the same RF system according to multiple standards. After framing more in detail the whole context of RF MEMS technology, this paper will provide a brief introduction on a typical RF-MEMS technology platform. Subsequently, some relevant examples of lumped RF MEMS passive elements and complex reconfigurable networks will be reported along with their measured RF performance and characteristics.
White Light Generation in Rare-Earth-Doped Amorphous Films Produced by Ultrasonic Spray Pyrolysis
Authors: Martínez-Martínez Rafael , Yescas Edgardo , Álvarez Enrique , Falcony Ciro , Caldiño Ulises
Published: September 2012

Aluminium and hafnium oxide films doped with CeCl3/TbCl3/MnCl2 were deposited at 300 °C by ultrasonic spray pyrolysis. The films analysed by X-Ray diffraction exhibit a very broad band typical of amorphous materials. Non-radiative energy transfer from Ce3+ to Tb3+ and Mn2+ is observed upon UV excitation at 280 nm (peak emission wavelength of AlGaN-based LEDs). Such energy transfer gives place to a simultaneous emission of the donor and acceptor ions in the blue, green, yellow and red regions, resulting in cold white light emission, with chromaticity coordinates and colour temperatures: (0.30,0.32) and 7300 K (AOCTM film), and (0.32,0.37) and 6400 K (HOCTM film). Thus, this type of thin films might contribute to the development of efficient AlGaN-based LEDs pumped phosphors for cold white light generation.
Development of Field-Controlled Smart Optic Materials (ScN, AlN) with Rare Earth Dopants
Authors: Kim Hyun Jung , Park Yeon Joon , King Glen C. , Choi Sang H.
Published: September 2012

Development of the fundamental materials for field-controlled spectrally active optics is essential for new concept of optics, such as: membrane optics, filters for LIDARs, windows for sensors and probes, telescopes, spectroscopes, cameras, light valves, light switches, flat-panel displays, etc. The dopants of rare earth elements create a number of absorption and emission band structures and can easily be incorporated into many high quality crystalline and amorphous hosts. In wide band-gap semiconductors, like ScN and AlN with rare earth dopants, the existing deep levels can capture or emit the mobile charges, and can be ionized with the loss or capture of the carriers. This is a fundamental basis for smart optic materials. ScN and AlN doped with rare earth elements (Er, Ho) were tested under an applied electric field to characterize spectral and refractive index shifts by the Stark Effect. Decrease in refractive index under an applied electric field was observed as a shift in absorption coefficient using a variable angle spectroscopic ellipsometer. Under an electric field, mobile carriers are redistributed within the space charge region (SCR) to reveal this electro-refractive effect. The main research goal is to facilitate concept demonstration and testing of field-controlled spectrally smart active optics for optical multi-functional capabilities in a selected spectral range.
Multimodal, High-Resolution Imaging System Based on Stimuli-Responsive Polymers
Authors: Paschew Georgi , Körbitz Rene , Richter Andreas
Published: September 2012

Providing realistic impressions about a virtual ambient for interaction with human’s auditory, visual, and tactile perception is one of the core challenges of modern imaging systems. However, particularly tactile displays with high spatial resolution implemented as a large-scale integrated microelectromechanical system are not yet realized. Here, we report on a multimodal display with thousands of actuator pixels, which generates both visual and tactile impressions of a virtual surface. The fully polymeric, monolithically integrated device consists of an actuator array made from poly(N-isopropylacrylamide). This material is a stimuli-responsive, particularly temperature-sensitive hydrogel. Controlling the actuator temperature via an optoelectrothermic interface between an upper and lower temperature the actuator can be switched from the swollen to the shrunken state (volume change up to 90%) in several hundred milliseconds. To benefit from this highly dynamic behaviour it is necessary to use a control unit which provides the required temperature changes also in the range of milliseconds. For characterizing the time behaviour of our optoelectrothermic control unit we use the change in transparency of PNIPAAm caused by the phase transition. In this paper we preferably discuss the time behaviour of the display devices.
Whispering Gallery Mode Microresonators for Biosensing
Authors: Soria Silvia , Berneschi Simone , Lunelli Lorenzo , Nunzi Conti Gualtiero , Pasquardini Laura , Pederzolli Cecilia , Righini Giancarlo C.
Published: September 2012

In the field of sensing, WGM microresonators are receiving a growing interest as optical structures suitable for the realization of miniature sensors with high sensitivity. When properly excited, WGM microresonators are able to strongly confine light, by means of total internal reflection,along the equatorial plane near their spherical surface. The corresponding supported resonances show low losses and a high quality factor Q (107-109). These high values of the Q factor make possible the detection of any minute event that occurs on the surface of the spherical microcavity. In fact, any minimum change in the surface of the sphere or in the physical and optical properties of the surrounding environment reduces the Q factor value and modifies the position of the resonancesinside the dielectric microcavity. From a direct measurement of this resonance shift, one can infer the amount of analyte that produces this variation.
Peculiarities of Adaptive Laser Location of Debris with Rough Surface
Authors: Bogachev Vladimir , Garanin Sergey , Maslov Nikita , Starikov Fedor , Volkov Vladimir
Published: September 2012

In the interests of the problem of debris search and detection we present the results of numerical simulation of projection of an outgoing laser beam through turbulent atmosphere onto the rough surface of a debris object using an adaptive mirror. For this purpose we analyze the wavefront vortex structure of the radiation, which is backscattered from the object surface and propagates through the turbulent atmosphere into a receiving aperture. Analysis shows that perfect phase conjugation does not ensure the maximal concentration of outgoing beam power on the object if the topological charge of backscattered radiation differs from zero in the receiving aperture. It is shown that the efficiency of focusing the outgoing laser beam onto the object can be enhanced by special control of a flexible adaptive mirror.
Deployable Structures
Authors: del Grosso Andrea E. , Basso Paolo
Published: September 2012

Deployable structures have been developed for many different applications from space to mechanical and civil engineering. In the paper the general concepts of deployable structures, combining static and kinematic behaviour are presented first, also discussing their relationships with adaptive and variable geometry structures. Reported applications to civil engineering and architecture are then reviewed and categorized. The characteristics of the following systems are summarized : 1. Pneumatic Structures. 2. Tensegrity Structures. 3. Scissor-like Structures. 4. Rigid Foldable Origami. 5. Mutually Supported Structures. The problems of form finding, direct and inverse kinematics, actuation and self-deployability for some of the most interesting among the above structural types are then discussed in the paper. Some examples involving rigid foldable origami and mutually supported structures are finally presented.
SHM System for Monitoring and Prediction of Cracks Development in Concrete Structures
Authors: Knor Grzegorz , Holnicki-Szulc Jan
Published: September 2012

This paper describes the concept of monitoring the massive concrete structures based on the inverse problem solution. Properties of young concrete are changing very intensively in the early stage of hydration process, and therefore it is very important to know material constants as a function of age of concrete in order to accurately modeling the phenomena occurring in it. The main idea is to determine the time-dependent thermal properties of concrete on the basis of point temperature measurements in a small laboratory molds. Then, based on these parameters, the coupled thermo-mechanical equations are solved to describe the maturation and aging of concrete. This allows to specify (at the design stage) the potential risk of structural damage (e.g. thermal cracking) and thus prevent them e.g. through the use of intelligent cooling systems. Own, based on finite element method, software TMC (Thermal & Mechanical modeling of Concrete) gives also the possibility of predicting the formation of cracks during the aging of structure, which will be verified by means of electric sensor networks (so called ELGRID). This integration will enable to provide a complete system for monitoring and prediction of the structural stress state and damage development.
Structural Control Issues in New Generation Offshore Wind Energy Plants
Authors: Luo Ning Su
Published: September 2012

A new constructive solution for the offshore wind power generation is to use floating wind turbines. An offshore wind farm situated sufficiently far away from the coast can generate more wind power and will have a longer operation life since the wind is stronger and more consistent than that on or near the coast. One of the main challenges is to reduce the fatigue of a floating wind turbine so as to guarantee its proper functioning under the constraints imposed by the floating support platforms. This paper will discuss the structural control issues related to the mitigation of dynamic wind and wave loads on the floating wind turbines so as to enhance the offshore wind power generation.
Fatigue of NiTi for Dampers and Actuators
Authors: Isalgue Antonio , Torra Vicenç , Casciati Fabio , Casciati Sara
Published: September 2012

The application of Shape Memory Alloy (SMA) devices to practical uses need well established performance. The reliable application in some areas, as dampers in engineering, needs a known, relatively long fatigue life (some million oscillations). The thermomechanical properties of SMA, based on their martensitic transformation, made them attractive to use for damping, taking advantage of the pseudoelastic window and hysteresis on transforming-retransforming. Due to size effects and to the fact that fatigue failure in metallic NiTi usually comes from a defect inducing crack growth, fatigue has to be studied for concrete applications, with the correct samples. The present work points out the possibility to apply NiTi to dampers and actuators. Testing machine experiments indicate that the main parameter controlling fatigue life is the effective stress on the NiTi wire. Long wire life (in the million cycle regime) can be achieved under limited stresses (around or under 200 MPa). Also, experiments have been done on thermal actuation of NiTi wire under traction at constant load. The results demonstrate that long actuator life (larger than 300000 cycles) can be achieved at low stresses (around 100 MPa), coherently with the mechanical cycling. From our results, NiTi is useful to effectively damp vibrations even at relatively low stresses and strains. The experimental results from facilities (cable No. 1 in ELSA-JRC, Ispra, Italy, and IFSTTAR test cable, near Nantes, France) confirm that NiTi wire is able to damp stayed cables.
Development of a Visualized Data Management System for Life-Cycle Health Monitoring of Civil Structures
Authors: Lin Ke Chang , Ni Yi Qing , Ye Xiao Wei , Wong Kai Yuan
Published: September 2012

The data management system (DMS) is an essential part for long-term structural health monitoring (SHM) systems, which stores a pool of monitoring data for various applications. A robust database within a DMS is generally used to archive, manage and update life-cycle information of civil structures. However, many applications especially those to large-scale structures provide little support for visualizing the long-term monitoring data. This paper presents the development of an efficient visualized DMS by integrating 4-dimension (4D) model technology, nested relational database, and virtual reality (VR) technology. Spatial data of the 4D model are organized in nested tables, while real-time (temporal) monitoring data are linked to the 4D model. The model is then reconstructed by use of an OpenSceneGraph 3D engine. A user interface is developed to query the database and display the data via the 4D model. To demonstrate its efficiency, the proposed method has been applied to the Canton Tower, a supertall tower-like structure instrumented with a long-term SHM system
Ultrasonic Guided Wave Monitoring of Railroad Tracks
Authors: Nucera Claudio , Phillips Robert , Lanza di Scalea Francesco
Published: September 2012

Among structural concerns for the safety of rail transportation are internal flaws and thermal stresses, both of which can cause disruption of service and even derailments. Ultrasonic guided waves lend themselves to addressing both of these problems. This paper reports on two inspection systems for rails being developed at UCSD under the auspices of the US Federal Railroad Administration. Both systems utilize ultrasonic guided waves as the main probing mechanism, for the two different applications of flaw detection and thermal stress detection.
NDE/SHM of Underwater Structures: A Review
Authors: Rizzo P.
Published: September 2012

Subsea infrastructures and broadly speaking any structure containing or surrounded by water such as water mains represent an important element of modern civilization. An arbitrary classification could consist of five groups: offshore structures that serve to extract oil or natural gas from the sea bead; communication cables; pipelines that carry oil and natural gas; naval vessels (ships and submarines); waterfront facilities such as piers, retaining walls, and docks. The occurrence of structural failure of any of these systems can have serious consequences for the people, the environment, and the economy. In this paper we describe the most important nondestructive techniques adopted to assess the health of offshore structures, pipelines, and marine facilities.
Model Order Reduction Issues for Integrated Structural Control Design
Authors: Casciati Fabio , Faravelli Lucia
Published: September 2012

Model Order Reduction (MOR) denotes the theory by which one tries to catch a model of order lower than that of the real model, in view of the design of an efficient structural control scheme. When the nonlinear response of the reference structural system affects the nature of the reduced model making it dependent on the visited subset of the input-output space, standard MOR techniques do not apply. The mathematical theory offers some specific alternatives. One of them is applied, in this paper, to a case study focused on a multi-bay, multi-storey plane frame with assigned locations for the potential plastic hinges.
Insight and Applications in Energy Harvesting from Bullets to Birds
Authors: Garcia Ephrahim , Shafer Michael W. , Bryant Matthew , Schlichting Alexander , Kogan Boris
Published: September 2012

Power requirements for microelectronics continue a downward trend and power production from vibrational power harvesting is ever increasing. The result is a convergence of technology that will allow for previously unattainable systems, such as infinite life wireless sensor nodes, health monitoring systems, and environmental monitoring tags, among others. The Laboratory of Intelligent Machine Systems at Cornell University has made many significant contributions to this field, pioneering new applications of piezoelectric energy harvesting, as well as contributing to harvesting circuitry and mechanical design theory. In this work, we present a variety of new applications for energy harvesting technology, including infinite life avian based bio-loggers, flutter induced vibrational wind power, and in-flight energy harvesting in munitions. We also present theoretical contributions to the field including an energy harvester beam design guide and multisource energy harvesting circuitry.
Mechanics and Model Based Control
Authors: Irschik Hans , Krommer Michael , Schlacher Kurt
Published: September 2012

The present contribution gives an overview on own research that has been performed from 2008 to 2011 in Area 2, Mechanics and Model Based Control, of the COMET K2 Austrian Center of Competence in Mechatronics (ACCM), which is situated at the Science Park of the Johannes Kepler University of Linz. Area 2 is motivated by the fact that mechanics and control both are rapidly expanding scientific fields, which share demanding mathematical and/or system-theoretic formulations and methods. The goal of Area 2 has been to utilize and extend these relations, with special emphasis on solid mechanics and control methods based on physical models. Some corresponding results will be reviewed subsequently with respect to the mechanical modelling of structures, robots and machines, and with respect to the corresponding model based control as linear/non-linear lumped/distributed parameter systems. Due to limitations in space, the present review restricts itself to work of Area 2 that has been directly performed at the University of Linz. The review contains 118 references to works on mechanics and model based control.
Development of some Smart Sensors for Monitoring Civil Infrastructures
Authors: Guan Xin Chun , Li Hui , Xiao Hui Gang , Qiao Guo Fu , Ou Jin Ping
Published: September 2012

In this paper, some smart sensors or material used to make the smart sensors, such as piezoresistance composite, piezoelectric polymer, piezoelectric cement and corrosion monitoring sensor, developed by Harbin Institute of Technology were introduced. Piezoresistance composite is made with carbon nanotube and resin, one character of the work is the carbon nanotube is orientation arranged by magnetic field. Piezoelectric polymer is made with PZT particles and PVDF, in order to improve its performance a few carbon nanotube are also mixed in the composite. Piezoelectric cement is one kind of sensing material whose primary raw materials are cement and piezoelectric ceramic particles (or fiber). The sensing performance of piezoelectric cement is coming from its functional phase, the piezoelectric ceramic. The corrosion monitoring sensor is made with solid-state reference electrode, whose surface is one kind of binary alloy membrane produced with physical vapor deposition technology. The main producing technology, performance and applications of above sensors were introduced in this paper.
Vibration-Based Damage Detection under Changing Environmental and Operational Conditions
Authors: Fritzen Claus Peter , Kraemer Peter , Buethe Inka
Published: September 2012

Structural Health Monitoring (SHM) allows to perform a diagnosis on demand which assists the operator to plan his future maintenance or repair activities. Using structural vibrations to extract damage sensitive features, problems can arise due to variations of the dynamical properties with changing environmental and operational conditions (EOC). The dynamic changes due to changing EOCs like variations in temperature, rotational speed, wind speed, etc. may be of the same order of magnitude as the variations due to damage making a reliable damage detection impossible. In this paper, we show a method for the compensation of changing EOC. The well-known null space based fault detection (NSFD) is used for damage detection. In the first stage, a training is performed using data from the undamaged structure under varying EOC. For the compensation of the EOC-e ects the undamaged state is modeled by different reference data corresponding to different representative EOC conditions. Finally, in the application, the influences of one or other EOC on each incoming data is weighted separately by means of a fuzzy-classiffcation algorithm. The theory and algorithm is successfully tested with data sets from a real wind turbine and with data from a laboratory model.
Mimicking the Anisotropic Behavior of Natural Porous Structures by Controlling the Reinforcing Particles Distribution in Polymeric Foams
Authors: Sorrentino Luigi , Aurilia Marco , D'Auria Marco , Davino Daniele , Mei Pasquale , Visone Ciro , Iannace Salvatore
Published: September 2012

Natural porous materials, like wood or bone, are multiscale cellular composite structures which exhibit mechanical (such as elasticity and strength) and functional (such as the thermal or acoustic insulating properties) behaviors dependent on the measuring direction. They show the best performance/weight ratio among all materials because their response is optimized in the needed direction by removing matter where not strictly functional, giving as a result a strong structural as well as morphological anisotropy. A new approach has been developed to mimic this behavior in polymeric foams, in which the mechanical and/or functional response of the cellular structure is tailored in a specific direction through the control of the spatial distribution and configuration of reinforcing particles. In order to demonstrate the concept, polymeric foams were produced with micro- or nano-sized reinforcement distributed along specific directions by means of the magnetic field. The effects of particles content, production parameters, and magnetic field strength were investigated and related to the mechanical (both elastic and magneto-elastic) performances.
Biomimetics in Energy Systems: Light Transmission in the Window Plant Fenestraria aurantiaca as Inspiration for New Solutions in the Technical World
Authors: Schäfer Immanuel
Published: September 2012

Fenestraria aurantiaca (also known as window plant) is a succulent with specialized adaptations to deal with heat, light and aridity. Fenestraria aurantiaca (F. a.) grows with most of its body under the sand. Just the top, with a light transparent surface – the window – on it, protrudes from the surface hence giving explanation to the plants name. Experiments with light, and detailed microscopy studies show the physical, biological and chemical capabilities of F. a. It was found that the window works as a lens, light from a 90 ° angle is directed into the plant. Thereby the window filters the light. Up to 90 % of the visible light is blocked; with rising wavelength the window gets more transparent until the near infrared light (1000 nm) where the transparency declines rapidly. But the parenchyma is up 90 % transparent. Based on those results the principles of the plant were defined, which are used for abstractions. Generally F.a. has four principles: light handling, surface cleaning, heat avoidance and water storing. Improvements founded on the inspiration of the window plant seem to be possible in photovoltaic systems, which have problems with overheating and also light concentration. An example solution called “buried solar cells” is presented. Another working field is the screen of mobile devices, where the clarity and readability suffers from direct sunlight. With the help from the methods displayed by F.a., there is an energy saving solution explained.
Electronics in Textiles – Adhesive Bonding Technology for Reliably Embedding Electronic Modules into Textile Circuits
Authors: von Krshiwoblozki Malte , Linz Torsten , Neudeck Andreas , Kallmayer Christine
Published: September 2012

The interconnection of electronics and textile circuits is still a main challenge for the fabrication of reliable smart textiles. This paper investigates the thermoplastic adhesive bonding technology. Electronic modules are bonded to textile substrates with a thermoplastic non-conductive adhesive (NCA) film. The modules are placed onto textile circuits with an NCA-film in-between. By applying pressure and heat, the adhesive melts and contact partners touch. Subsequently cooling solidifies the NCA resulting in an electrical and mechanical contact of the electronic module and the textile circuit. This paper shows the suitability of this technology for knitted, woven, non-woven and embroidered fabrics with metal coated yarns as well as with litz-wires as conductors. Besides, it shows that the interconnection process works well with thermoplastically insulated conductors. In addition, the design of interposers has been improved in respect to contact formation and miniaturization compared to previous publications. The pitch of the contact pads is set to 1.27 mm. A textile display was realized with smart RGB-Pixels, which are controlled by an I²C-bus on a quadrupolic woven substrate. It demonstrates the applicability and the potential of this technology.
Implantable Measurement System for Dairy-Cattle Monitoring with Long Recording Time
Authors: Bjarnason Asgeir , Vuorela Timo , Verho Jarmo , Riistama Jarno , Vanhala Jukka , Lekkala Jukka , Hyttinen Jari
Published: September 2012

This paper describes a new implantable measurement system, further developed from an implantable measurement device implemented earlier at Tampere University of Technology (TUT), to assess the psychophysiological state of well-being of dairy-cattle. By measuring single-channel Electrocardiogram (ECG), body temperature and cattle activity we provide veterinarians and animal scientists with a tool to assess cattle stress levels and well-being. This information can, for example, be linked to cattle milk production. The new device processes the ECG signal in real-time to derive the heart rate along with a wireless radio frequency transmission of the data from the implant to a receiver device attached near or on the cattle. By collecting the data through a wireless link we are able to extend the recording period from three weeks of the earlier version of the device up to 3 months. The algorithm for the ECG peak detection is a modified version of the Pan-Tompkins algorithm optimized for cattle application with ECG recordings based on several hundred hours of data collected from previous experiments and recordings. The implantable system was tested with in vivo trials in April 2012.
Movable Polyrotaxane Surfaces for Modulating Cellular Adhesion via Specific RGD-Integrin Binding
Authors: Seo Ji Hun , Kakinoki Sachiro , Yamaoka Tetsuji , Yui Nobuhiko
Published: September 2012

Immobilizing bioactive molecules on the materials surfaces is one of the main strategies for creating functional bio-interfaces. In these kinds of bio-interfaces, the density of immobilized functional groups and the following physicochemical factors such as roughness, polarity and electrical charge have been thought important variables for regulating biological responses such as cell adhesion and differentiations. Here in this study, differences between rigidity and dynamically immobilized bioactive molecules on the biological responses will be discussed. In order to develop dynamic bio-interfaces, a polyrotaxane based block-copolymer containing clickable azide groups for conjugating various bioactive molecules was designed. Cell adhesive RGD peptide was then conjugated with the azide group by click reaction on both dynamic and rigid surfaces. As a result, cell adhesive RGD peptide immobilized on the dynamic bio-interfaces shows larger initial cell adhesion area, indicating that molecular dynamics of surface chemical groups is another important variable for the regulation of biological responses.
Application of α-TCP/HAp Functionally Graded Porous Beads for Bone Regenerative Scaffold
Authors: Tamura A. , Asaoka Teruo , Furukawa K. , Ushida T. , Tateishi T.
Published: September 2012

α-TCP/HAp functionally graded porous beads were prepared for use as a scaffold for bone regeneration. In this research, porous beads which have compositionally graded layer, from TCP of inner area to HAp of surface area, were fabricated. It is known that the dissolution rate of TCP is fast in compare with that of HAp in living body, thus the inner area would dissolve prior to the surface area. These beads to allow the penetration of cells and blood vessel into the inner area of beads following new bone regeneration. At present, conditions to fabricate the functionally graded porous beads have been established already, and experiments using cells [MC3T3-E1] are in progress.
Design of Biodegradable Injectable Polymers Exhibiting Temperature-Responsive Sol-Gel Transition
Authors: Ohya Yuichi , Suzuki Hiroyuki , Nagahama Koji , Takahashi Akihiro , Ouchi Tatsuro , Kuzuya Akinori
Published: September 2012

Starburst triblock copolymers consisting of 8-arm poly(ethylene glycol) (8-arm PEG), poly(L-lactide) (PLLA) or its enantiomer poly(D-lactide) (PDLA) and terminal PEG, 8-arm PEG-b-PLLA-b-PEG (Stri-L) and 8-arm PEG-b- PDLA-b-PEG (Stri-D), were synthesized. An aqueous solution of a 1:1 mixture (Stri-Mix) of Stri-L and Stri-D assumed a sol state at room temperature, but instantaneously formed a physically cross-linked hydrogel in response to increasing temperature. The resulting hydrogel exhibited a high storage modulus at 37 °C. The rapid temperature-triggered hydrogel formation, high mechanical strength, and degradation behavior render this polymer system suitable for use in injectable drug delivery system or a biodegradable scaffold for tissue engineering.
Characterization of Hydrogels Based on PVP/Sodium Alginate Containing Pseudoboehmites Nanoparticles Treated with Octadecylamine for Pharmaco Applications
Authors: de Miranda Leila Figueiredo , Munhoz Antonio Hortêncio , Terence Mauro Cesar , Rigolin Talita Rocha , Engel Laura
Published: September 2012

Abstract. Hydrogels based on poly (N-vinyl-2-pyrrolidone) (PVP) obtained by ionizing radiation are sterile, biocompatible can be used as topics dressings. Due to the high degree of hydration of the gel, it has a low mechanical strength, which is one of the biggest problems in its application. The objective of this work was to study the properties of the hydrogel based on PVP / sodium alginate containing pseudoboehmites nanoparticles treated with octadecylamine for pharmaco applications, order drug release when immobilized on a matrix of PVP/sodium alginate/pseudoboehmite. Pseudoboehmite nanoparticles were obtained by sol-gel route, from aluminum nitrate and ammonia as precursors, and subsequently were treated with octadecylamine. The hydrogels based on PVP/sodium alginate/pseudoboehmite treated were prepared by ionizing radiation with doses of 30 and 35kGy. The characterization of hydrogels obtained was made by means of thermomechanical (tensile tests, DTA and TG) and physicochemical (swelling, sol-gel fraction) tests. The results obtained showed that the hydrogel based only on PVP and sodium alginate showed highest tensile strength. The presence of pseudoboehmite in the hydrogels decreases the formation of crosslinks, while the presence of PEG in the agar and causes a decrease in Tg of the polymer matrix.
Intrauterine Growth Standards: A Cross-Sectional Study in A Population of Nigerian Newborns
Authors: Mokuolu Olugbenga A. , Adesiyun Omotayo O. , Suleiman Mohammed B. , Bello Mustapha
Published: September 2012

The aim of the study was to define an intrauterine growth curve for a population of Nigerian newborn babies. A cross-sectional observational study design was adopted. Weight, length and head circumference were all measured in consecutive singleton deliveries at the University of Ilorin Teaching Hospital over a 3-year period. Gestational age (GA) of the babies was estimated from the last menstrual period or first trimester ultrasound. The estimates obtained were clinically validated using the Ballard score. Mean birth weights and percentiles of the weight, length and head circumferences for the respective GA were estimated using the SPSS 15 software package. A total of 5273 babies were recruited for the study with GA ranging from 25-44 weeks. Comparison of the mean birth weights of the various GA with the data from Denver, Colorado, showed that Nigerian babes tended to weigh less at the early GA, although these differences were not statistically significant. Between 26-36 weeks, the average weights of both sexes were similar; however, beyond this time point there was a consistent increase in the average weight of the males over the female babies. Growth curves for Nigerian newborn babies were generated and showed that the mean birth weight of Nigerian preterm babies was lighter than that of babies in Colorado. The impact of these differences on the classification of newborns will require further evaluation.
Downhole geophysical data from boreholes along the Spiritwood buried valley aquifer near Cartwright, Killarney, and southeast of Brandon, Manitoba
Authors: Crow H L , Brewer K D , Pugin A J -M , Russell H A
J
Published: October 2012

Contents: Open File 7080 documents work completed by the Geological Survey of Canada in support of Natural Resources Canada's 'Groundwater Geoscience Program', as part of the aquifer assessments and mapping of 30 key Canadian aquifers. Buried Valleys are one
thematic aquifer type that are common across Canada and are of particular importance in the Prairie Provinces. The Spiritwood buried valley aquifer study in south-western Manitoba is investigating an area of approximately 1000 km2 extending northward from the USA - Manitoba border.
This Open File contains the results of the downhole geophysical logging conducted in nine boreholes along the inferred lengths of the Spiritwood and Yellowstone-Missouri buried valleys. The boreholes were independently drilled by Manitoba Water Stewardship (MWS), the Town of Killarney, and the GSC.
The objective of the surveys was to measure a range of chemical and physical properties of the subsurface materials, and compare these results to those of the surface and airborne geophysical surveys previously carried out in the region by the GSC.
Epidemiologic and Molecular Pathophysiology of Chronic Opioid Dependence and the Place of Naltrexone Extended-Release Formulations in its Clinical Management
Authors: Reece Albert Stuart
Published: September 2012

Naltrexone implants and depot injections (NI) are a novel form of treatment for opiate dependence (OD). Major questions relate to their absolute and relative efficacy and safety. Opportunely, six recent clinical trial data from several continents have uniformly provided dramatic evidence of the potent, dose-related and highly significant efficacy of NI, with minimal or manageable accompanying toxicity and safety concerns. The opiate-free lifestyle is attained significantly more often with NI adjusted O.R. = 6.00 (95% C.I. 3.86–9.50), P < 10-10. Other drug use and drug craving are also rapidly reduced. The optimum manner in which to commence NI remains to be established. Of particular relevance is the relative safety of NI compared to the chronic opiate agonists (COA) usually employed, as the long-term toxicity of COA is only just being elucidated. Large population-based studies have found elevated rates of cardiovascular disease, six cancers, liver and respiratory disease, and all-cause mortality in COA. Whilst opiates have been shown to trigger numerous molecular pathways, the most interesting is the demonstration that the opiate morphinan's nucleus binds to the endotoxin groove of the TLR4-MD2 heterodimer. This has the effect of triggering a low grade endotoxaemic-like state, which over time may account for these protean clinical findings, an effect which is reversed by opiate antagonists. This emerging evidence suggests an exciting new treatment paradigm for OD and a corresponding increase in the role of NI in treatment.
Distúrbios da Consciência Humana - Parte 1 de 3
Authors: Mendes Plínio Duarte , Maciel Marina de Souza , Brandão Marcus Vinícius Teixeira , Fernandes Paulo César Rozental , Antonio Vanderson Esperidião , Kodaira Sérgio Keidi , Batista Rodrigo Siqueira
Published: October 2012

A consciência é o perfeito estado do conhecimento de si próprio e do ambiente, bem como a responsividade específica a variados estímulos internos e externos. O presente artigo tem por objetivo apresentar os aspectos morfofuncionais, fisiopatológicos e as bases neurobiológicas das mais prevalentes condições mórbidas que envolvam alterações do nível de consciência. Para tal, foi realizada uma revisão da literatura apoiada em artigos obtidos através das bases LILACS (Literatura Lati­no-Americana e do Caribe em Ciências da Saúde), SciELO (Scientific Electronic Library Online) e PubMed (U. S. National Library of Me­dicine), além de livros-texto de neurologia e de neurociências. Neste primeiro artigo enfoca-se (1) a formação reticular – importante estru­tura nervosa relacionada à consciência –, a qual é constituída por um conjunto de fibras nervosas originadas posteriormente ao tronco ence­fálico, que formam feixes ascendentes capazes de atingir o diencéfalo e ativar o telencéfalo. Distúrbios nestas áreas, de origem traumática ou não, podem levar ao comprometimento das funções tálamo-corticais e, consequentemente, a alterações do nível de consciência.
Outcomes of Patients with Melioidosis Treated with Cotrimoxazole Alone for Eradication Therapy
Authors: Chusri Sarunyou , Hortiwakul Thanaporn , Charoenmak Boonsri , Silpapojakul Khachornsakdi
Published: October 2012

We retrospectively reviewed a 10-year experience of administration of cotrimoxazole alone in 31 patients compared with 109 patients who received conventional eradication therapy (cotrimoxazole plus doxycycline). The baseline characteristics, the clinical manifestations, the initial intravenous antibiotic treatments, and the mean duration of eradication therapy between the two groups were similar. The culture-confirmed recurrences among the patients who received cotrimoxazole alone and those who received the conventional regimen were not significantly different (1/31 [3.2%] versus 5/109 [4.5% odds ratio = 0.69 [95% confidence interval [CI] = 0.08–6.17]). Gastrointestinal side effects were more common among the conventional regimen group (28/109 [25.7%] versus 2/31 [6.5%], P = 0.02) and the proportion of patients who could complete at least 20 weeks of therapy without having switched to the other regimen was significantly lower (91/109 [83.5%] versus 31/31 [100.0%] P = 0.01). Cotrimoxazole alone is as effective as and better tolerated than cotrimoxazole plus doxycycline for the eradication treatment of melioidosis.
Calibration of column-averaged CH4 over European TCCON FTS sites with airborne in-situ measurements
Authors: Geibel M. C. , Messerschmidt J. , Gerbig C. , Blumenstock T. , Chen H. , Hase F. , Kolle O. , Lavrič J. V. , Notholt J. , Palm M. , Rettinger M. , Schmidt M. , Sussmann R. , Warneke T. , Feist D. G.
Published: September 2012

Abstract. In September/October 2009, six European ground-based Fourier Transform Spectrometers (FTS) of the Total Carbon Column Observation Network (TCCON) were calibrated for the first time using aircraft measurements. The campaign was part of the Infrastructure for Measurement of the European Carbon Cycle (IMECC) project. During this campaign, altitude profiles of several trace gases and meteorological parameters were taken close to the FTS sites (typically within 1–2 km distance for flight altitudes below 5000 m). Profiles of CO2, CH4, CO and H2O were measured continuously. N2O, H2, and SF6 were later derived from flask measurements. The aircraft data had a vertical coverage ranging from approximately 300 to 13 000 m, corresponding to ~80% of the total atmospheric column seen by the FTS. This study summarizes the calibration results for CH4. The resulting calibration factor of 0.978 ± 0.002 (±1 σ) from the IMECC campaign agreed very well with the results that Wunch et al. (2010) had derived for TCCON instruments in North America, Australia, New Zealand, and Japan using similar methods. By combining our results with the data of Wunch et al. (2010), the uncertainty of the calibration factor could be reduced by a factor of three (compared to using only IMECC or only Wunch et al. (2010) data). A careful analysis of the calibration method used by Wunch et al. (2010) revealed that the incomplete vertical coverage of the aircraft profiles can lead to a bias in the calibration factor. This bias can be compensated with a new iterative approach that we developed. Using this improved method, we derived a significantly lower calibration factor of 0.974 ± 0.002 (±1 σ). This corresponds to a correction of all TCCON CH4 measurements by roughly −7 ppb.
In-canopy gas-phase chemistry during CABINEX 2009: sensitivity of a 1-D canopy model to vertical mixing and isoprene chemistry
Authors: Bryan A. M. , Bertman S. B. , Carroll M. A. , Dusanter S. , Edwards G. D. , Forkel R. , Griffith S. , Guenther A. B. , Hansen R. F. , Helmig D. , Jobson B. T. , Keutsch F. N. , Lefer B. L. , Pressley S. N. , Shepson P. B. , Stevens P. S. , Steiner A. L.
Published: September 2012

Abstract. Vegetation emits large quantities of biogenic volatile organic compounds (BVOC). At remote sites, these compounds are the dominant precursors to ozone and secondary organic aerosol (SOA) production, yet current field studies show that atmospheric models have difficulty in capturing the observed HOx cycle and concentrations of BVOC oxidation products. In this manuscript, we simulate BVOC chemistry within a forest canopy using a one-dimensional canopy-chemistry model (Canopy Atmospheric CHemistry Emission model; CACHE) for a mixed deciduous forest in northern Michigan during the CABINEX 2009 campaign. We find that the base-case model, using fully-parameterized mixing and the simplified biogenic chemistry of the Regional Atmospheric Chemistry Model (RACM), underestimates daytime in-canopy vertical mixing by 50–70% and by an order of magnitude at night, leading to discrepancies in the diurnal evolution of HOx, BVOC, and BVOC oxidation products. Implementing observed micrometeorological data from above and within the canopy substantially improves the diurnal cycle of modeled BVOC, particularly at the end of the day, and also improves the observation-model agreement for some BVOC oxidation products and OH reactivity. We compare the RACM mechanism to a version that includes the Mainz isoprene mechanism (RACM-MIM) to test the model sensitivity to enhanced isoprene degradation. RACM-MIM simulates higher concentrations of both primary BVOC (isoprene and monoterpenes) and oxidation products (HCHO, MACR+MVK) compared with RACM simulations. Additionally, the revised mechanism alters the OH concentrations and increases HO2. These changes generally improve agreement with HOx observations yet overestimate BVOC oxidation products, indicating that this isoprene mechanism does not improve the representation of local chemistry at the site. Overall, the revised mechanism yields smaller changes in BVOC and BVOC oxidation product concentrations and gradients than improving the parameterization of vertical mixing with observations, suggesting that uncertainties in vertical mixing parameterizations are an important component in understanding observed BVOC chemistry.
Phenomenology of convection-parameterization closure
Authors: Yano J.-I. , Bister M. , Fuchs Z. , Gerard L. , Phillips V. , Barkidija S. , Piriou J.-M.
Published: September 2012

Abstract. Closure is a problem of defining the convective intensity in a given parameterization. In spite of many years of efforts and progress, it is still considered an overall unresolved problem. The present article reviews this problem from phenomenological perspectives. The variables that are expected to contribute in defining the convective intensity are listed, and their statistical significances identified by observational data analyses are reviewed. A possibility is discussed for identifying a correct closure hypothesis by performing a linear stability analysis of tropical convectively-coupled waves with various different closure hypotheses. Various individual theoretical issues are considered from various different perspectives. Finally, it is emphasized that the dominant physical factors controlling convection differ between the tropics and extra-tropics, as well as between oceanic and land areas. Both observational as well as theoretical analyses, often focused on the tropics, do not necessarily lead to conclusions consistent with our operational experiences focused on midlatitudes. Though we emphasize the importance of the interplays between these observational, theoretical and operational perspectives, we also face challenges for establishing a solid research framework that is universally applicable.