bluuebunny/crossref_metadata_2025_split huggingface dataset:
Unsteady dynamics and organized structures from DNS over an idealized building canopy
Authors: Coceal Omduth , Dobre Adrian , Thomas T. G. 
Published: July 2007

AbstractA numerical study is performed to elucidate the dominant turbulent processes that occur in urban areas. Comprehensive data from direct numerical simulations (DNS) over idealized three‐dimensional arrays of buildings are analysed to study the unsteady and organized aspects of the turbulent flow. The accuracy of the DNS is evaluated by comparing turbulence statistics with a high quality wind‐tunnel dataset. The simulation results are studied using flow visualization as well as statistical methods including quadrant analysis, space‐time two‐point correlations and conditional averaging. Three regimes of the flow are identified. First, the rough wall flow above the buildings has turbulent organized structures that resemble the ‘hairpin vortices’ and ‘low momentum regions’ that are well known to occur in the turbulent boundary layer over smooth walls. These hairpin‐like vortices contribute dominantly to vertical momentum transport. Secondly, shear layers develop over the tops of the buildings and shed structures that may sometimes impinge upon downstream buildings and drive a robust recirculation within the building canopy. These unsteady canopy‐top shear layers and their interaction with the larger eddies above provide important mechanisms for coupling with the flow within the canopy. Thirdly, the flow within the building canopy is the result of complicated interactions between the above and eddies shed off the vertical edges of the buildings, and their distortion caused by impacting buildings. Mean flow patterns around the buildings are important and lead to significant dispersive stresses. Implications for scalar transport and dispersion are briefly discussed. Copyright © 2007 Royal Meteorological Society
High resolution DNA separations using microchip electrophoresis
Authors: Sinville Rondedrick , Soper Steven A. 
Published: July 2007

AbstractPlanar microfluidic devices have emerged as effective tools for the electrophoretic separation of a variety of different DNA inputs. The advancement of this miniaturized platform was inspired initially by demands placed on electrophoretic performance metrics by the human genome project and has provided a viable alternative to slab gel and even capillary formats due to its ability to offer high resolution separations of nucleic acid materials in a fraction of the time associated with its predecessors, consumption of substantially less sample and reagents while maintaining the ability to perform many separations in parallel for realizing ultra‐high throughputs. Another compelling advantage of this separation platform is that it offers the potential for integrating front‐end sample preprocessing steps onto the separation device eliminating the need for manual sample handling. This review aims to compile a recent survey of various electrophoretic separations using either glass or polymer‐based microchips in the areas of genotyping and DNA sequencing as well as those involving the growing field of DNA‐based forensics.
Principles of palm olein fractionation: a bit of science behind the technology
Authors: Calliauw Gijs H. , Gibon Véronique , De Greyt Wim F.J. 
Published: July 2007

AbstractDry fractionation is a well‐established and versatile fat modification technology that can produce a broad spectrum of edible oils and fats. Due to its specific chemical composition, especially palm oil can be processed by this technology into fractions that serve as salad oils, frying oils, margarine fats. Whereas the first step of this multi‐stage production process is well understood, the edible oil industry all over the world is much more often confronted with problems in the second stage of the process, when the liquid palm olein is further fractionated. The process of palm olein crystallization is indeed a lot more difficult to control. This article therefore elaborately explains the main, fundamental causes for this sensitivity of palm olein during the fractional crystallization. It further discusses which and how components present in refined palm olein can be responsible for process instability and how they affect the quality of the end products on an industrial scale. The article also highlights which novelties and innovation in dry fractionation technology are currently under investigation.
Alternative fat sources to animal fat for pigs
Authors: Lauridsen Charlotte , Bruun Christensen Thomas , Halekoh Ulrich , Krogh Jensen Søren 
Published: July 2007

AbstractThe use of fats and oils in diets for pigs is of great importance due to their high energy value. As a consequence of the BSE‐crisis in the European Union, the amount of animal fat available for animal feeds has been reduced, and alternative fat sources are of increasing importance. In this paper, we review our main findings on the effects of diets with different fat sources on apparent fat digestibility in pigs. A method for quantitative measurement of fat extraction from feed and faeces has been developed, and this method has been used in a digestibility trial, in which diets added 5% of either animal fat, palm oil mix, palm oil, vegetable oil mix, coconut oil, or rapeseed oil were tested in weaned and growing pigs. It was concluded that several vegetable fat sources (palm oil mix, palm oil, coconut oil, rapeseed oil) could be used as alternatives to animal fat in pig feed, whereas fat blends should be avoided.
The electrophysiological muscle scan
Authors: Blok Joleen H. , Ruitenberg Annemieke , Maathuis Ellen M. , Visser Gerhard H. 
Published: July 2007

AbstractThis study aims to assess the potential of the electrophysiological muscle scan or stimulus–response curve as a diagnostic instrument. If stimulus intensity is gradually increased from subthreshold to supramaximal values, all motor units in a muscle are successively activated. Thus, by plotting response size versus stimulus intensity, an impression (scan) of the entire muscle can be obtained. We recorded 54 detailed scans from 34 patients and 11 healthy subjects, and analyzed them visually and quantitatively. The scan summarized much diagnostic information in a single picture. Specific patterns in or properties of the scan (steps, maximum, variability, decrements, stimulus intensities used) provide clinically relevant information regarding motor unit number, size, and stability, and neuromuscular transmission and axonal excitability. The scan can be recorded noninvasively in about 5 minutes and is fairly easy to interpret. Because it is built up from contributions of all functioning motor units, the scan shows if and how many large motor units are present. There is no sample bias. For these reasons, further exploration and exploitation of this tool in the clinical setting are warranted. Muscle Nerve, 2007
NMR spectroscopic identification of cholesterol esters, plasmalogen and phenolic glycolipids as fingerprint markers of human intracranial tuberculomas
Authors: Subramanian Arunachalam , Shankar Joshi Bhawani , Roy Abhijeet Deb , Roy Raja , Gupta Vivek , Dang Ramandeep S. 
Published: July 2007

AbstractDetailed 1H and 13C NMR spectroscopy of lipid extracts from 12 human intracranial tuberculomas and two control brain tissue samples was performed to assess the role of lipids in the disease process. One‐dimensional and two‐dimensional NMR techniques were used to resolve the mixture of lipid components and make resonance assignments. The lipid components that could be identified in tuberculoma lipid extracts and not in control samples were: cholesterol ester, plasmalogen and phenolic glycolipids. It is proposed that the combined occurrence of these lipid components can be used as ‘fingerprint markers’ for the differentiation of intracranial tuberculoma from healthy brain tissue. Furthermore, phenolic glycolipids present in intracranial tuberculomas may have diagnostic significance in differentiating them from other disease conditions of the central nervous system such as malignant tumors. Copyright © 2007 John Wiley & Sons, Ltd.
RAFT synthesis of a water‐soluble triblock copolymer of poly(styrenesulfonate)‐b‐poly(ethylene glycol)‐b‐poly(styrenesulfonate) using a macromolecular chain transfer agent in aqueous solution
Authors: Peng Zhiping , Wang Dandan , Liu Xinxing , Tong Zhen 
Published: July 2007

AbstractTriblock copolymers of poly(styrenesulfonate)‐b‐poly(ethylene glycol)‐b‐poly(styrenesulfonate) with narrow molecular weight distribution (Mw/Mn = 1.28–1.40) and well‐defined structure have been synthesized in aqueous solution at 70 °C via reversible addition‐fragmentation chain transfer polymerization. Poly(ethylene glycol) (PEG) capped with 4‐cyanopentanoic acid dithiobenzoate end groups was used as the macro chain transfer agent (PEG macro‐CTA) for sole monomer sodium 4‐styrenesulfonate. The reaction was controllable and displayed living polymerization characteristics and the triblock copolymer had designed molecular weight. The reaction rate depended strongly on the CTA and initiator concentration ratio [CTA]0/[ACPA]0: an increase in [CTA]0/[ACPA]0 from 1.0 to 5.0 slowed down the polymerization rate and improved the molecular weight distribution with a prolonged induction time. The polymerization proceeded, following first‐order kinetics when [CTA]0/[ACPA]0 = 2.5 and 5.0. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3698–3706, 2007
End group effect on the thermo‐sensitive properties of well‐defined water‐soluble polystyrenics with short pendant oligo(ethylene glycol) groups synthesized by nitroxide‐mediated radical polymerization
Authors: Jiang Xueguang , Zhao Bin 
Published: July 2007

AbstractThe effects of hydrophobic chain end groups on the cloud points of thermo‐sensitive water‐soluble polystyrenics were investigated. Well‐defined poly (4‐vinylbenzyl methoxytris(oxyethylene) ether) (PTEGSt) and poly(α‐hydro‐ω‐(4‐vinylbenzyl)tetrakis(oxyethylene)) (PHTrEGSt) were prepared by nitroxide‐mediated radical polymerization using α‐hydrido alkoxyamine initiators including two monomer‐based initiators. The polymers were reduced with (n‐Bu)3SnH to replace the alkoxyamine end group with hydrogen. In the studied molecular weight range (Mn,GPC = 3000 to 28,000 g/mol), we found that the hydrophobic end groups decreased the cloud point by 1–20 °C depending on the molecular weight and the largest depression was observed at the lowest molar mass. The cloud points of PTEGSt and PHTrEGSt with two hydrophobic end groups, phenylethyl and alkoxyamine, exhibited a monotonic increase with the increase of molecular weight. For polymers with only one hydrophobic end group, either phenylethyl or alkoxyamine, the cloud point initially increased with the increase of molecular weight but leveled off/decreased slightly with further increasing molar mass. For polymers with essentially no end groups, the cloud point decreased with the increase of chain length, which represents the “true” molecular weight dependence of the cloud point. The observed molecular weight dependences of the cloud points of polystyrenics with hydrophobic end group(s) are believed to result from the combined end group effect and “true” molecular weight effect. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3707–3721, 2007
Grafting of methacrylates and styrene on to polystyrene backbone via a “grafting from” ATRP process at ambient temperature
Authors: Vivek A. V. , Dhamodharan R. 
Published: July 2007

AbstractWell defined graft copolymers are prepared by “grafting from” atom transfer radical polymerization (ATRP) at room temperature (30 °C). The experiments were aimed at grafting methacrylates and styrene at latent initiating sites of polystyrene. For this purpose, the benzylic hydrogen in polystyrene was subjected to allylic bromination with N‐bromosuccinimide and azobisisobutrylnitirle to generate tertiary bromide ATRP initiating sites (BrCPS). The use of BrCPS with lesser mol % of bromide initiating groups results in better control and successful graft copolymerization. This was used to synthesize a series of new graft copolymers such as PS‐g‐PBnMA, PS‐g‐PBMA, PS‐g‐GMA, and PS‐g‐(PMMA‐b‐PtBA) catalyzed by CuBr/PMDETA system, in bulk, at room temperature. The polymers are characterized by GPC, NMR, FTIR, TEM, and TGA. Graft copolymerization followed by block polymerization enabled the synthesis of highly branched polymer brush, in which the grafting density can be adjusted by appropriate choice of bromide concentration in the polystyrene. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3818–3832, 2007
Synthesis, characterization, and influence of synthesis parameters on particle sizes of a new microgel family
Authors: Martínez Virginia Sáez , Álvarez Leyre Pérez , Hernáez Estíbaliz , Herrero Teresa , Katime Issa 
Published: July 2007

AbstractPoly(p‐nitrophenylacrylate‐co‐methacrylamide) and poly(p‐Nitrophenylacrylate‐co‐N,N′‐isopropylacrylamide) reactive microgels were synthesized by precipitation polymerization. The process was followed qualitatively by infrared spectroscopy (ATR‐FTIR) and microgels composition was determined by nuclear magnetic resonance (1H NMR). Scanning electron microscopy of obtained colloidal particles showed strictly spherical morphologies with a moderate polydispersity. The average hydrodynamic particle diameter and particle size distributions were measured by quasi‐elastic light scattering and the particle size distributions obtained ranged from 100 to 600 nm. Several synthetic parameters affect the particle size of these materials and thus, indirectly, their properties and future applications. In this article, we report the influence of different polymerization reaction conditions in the final microgel dimensions. For example, we observed that the different solvent‐comonomer affinity induced a significant change in swollen particle size of the copolymeric microgels. On the other hand, the crosslinking density limited the particle sizes, but an excess of crosslinker content in the reaction mixture resulted in the opposite effect. Finally, we also studied the influence of initiator content in the mean particle size. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 3833–3842, 2007
Arborescent polymers and other dendrigraft polymers: A journey into structural diversity
Authors: Gauthier Mario 
Published: July 2007

AbstractArborescent polymers are characterized by a dendritic, multilevel branched architecture derived from successive grafting reactions. In spite of their much larger size, these materials display properties analogous to dendrimers and hyperbranched polymers, the two other dendritic polymer families. The distinguishing features of arborescent polymers are their assembly from polymeric building blocks of uniform size and their very high molecular weights attained in few synthetic steps. This article offers an overview of the historical aspects of the development of dendrigraft polymers, starting from our initial efforts on the synthesis of arborescent polystyrenes. Major subsequent developments in the synthetic techniques from our and other research groups allowing the synthesis of dendrigraft copolymers, tailoring of the structural characteristics of the molecules, and further simplifications to their synthesis are also reviewed, with emphasis over the broad range of architectures attainable in these systems. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 3803–3810, 2007
Optical delineation of benthic habitat using an autonomous underwater vehicle
Authors: Moline Mark A. , Woodruff Dana L. , Evans Nathan R. 
Published: July 2007

AbstractTo better characterize and improve our understanding of coastal waters, there has been an increasing emphasis on autonomous systems that can sample the ocean on relevant scales. Autonomous underwater vehicles (AUVs) with active propulsion are especially well suited for studies of the coastal ocean because they are able to provide systematic and near‐synoptic spatial observations. With this capability, science users are beginning to integrate sensor suits for a broad range of specific and often novel applications. Here, the relatively mature Remote Environmental Monitoring Units (REMUS) AUV system is configured with multi‐spectral radiometers to delineate benthic habitat in Sequim Bay, WA. The vehicle was deployed in a grid pattern along 5 km of coastline in depths from 30 to less than 2 m. Similar to satellite and/or aerial remote sensing, the bandwidth ratios from the downward looking radiance sensor and upward looking irradiance sensor were used to identify beds of eelgrass on submeter scales. Strong correlations were found between the optical reflectance signals and the geo‐referenced in situ data collected with underwater video within the grid. Results demonstrate the ability of AUVs to map littoral habitats at high resolution and highlight the overall utility of the REMUS vehicle for near‐shore oceanography. © 2007 Wiley Periodicals, Inc.
Development of the DORADO mapping vehicle for multibeam, subbottom, and sidescan science missions
Authors: Kirkwood W. J. 
Published: July 2007

AbstractOceanographic science is frequently hindered by a lack of spatial and temporal resolution for most parameters oceanographic science desires to measure. This paper discusses our effort to advance the current state of bathymetric mapping as part of the Monterey Bay Aquarium Research Institute (MBARI) charter. MBARI scientists and engineers, in consultation with the external community, have produced a new multibeam mapping autonomous underwater vehicle (AUV) system. The system is intended to reduce some of the impediments encountered by science trying to resolve specific portions of the oceans bottom. Starting with the established and in‐house developed Dorado AUV technology, MBARI engineering refined the AUV into a full ocean depth capable and now operational multibeam mapping system (MBAUV). The MBAUV system conducts regular multibeam bathymetry, subbottom, and sidescan surveys for oceanographic science. MBAUV is a torpedo‐shaped, 6000 m rated vehicle operating the aforementioned sonars simultaneously. The endurance of the MBAUV is approximately 8 h at 3 kn and is designed to support 16 h operations at 3 kn by adding an additional battery section. This paper describes the basics of the MBAUV and our design trades and modifications to the Dorado AUV in support of multibeam mapping missions. The paper also reviews a sampling of the results from a series of missions that demonstrate the performance of various subsystems and the science quality data available from the MBAUV. © 2007 Wiley Periodicals, Inc.
An integrated diagnostic architecture for autonomous underwater vehicles
Authors: Hamilton K. , Lane D. M. , Brown K. E. , Evans J. , Taylor N. K. 
Published: July 2007

AbstractThe architecture of an advanced fault detection and diagnosis (FDD) system is described and applied with an Autonomous Underwater Vehicle (AUV). The architecture aims to provide a more capable system that does not require dedicated sensors for each fault, can diagnose previously unforeseen failures and failures with cause‐effect patterns across different subsystems. It also lays the foundations for incipient fault detection and condition‐based maintenance schemes. A model of relationships is used as an ontology to describe the connected set of electrical, mechanical, hydraulic, and computing components that make up the vehicle, down to the level of least replaceable unit in the field. The architecture uses a variety of domain dependent diagnostic tools (rulebase, model‐based methods) and domain independent tools (correlator, topology analyzer, watcher) to first detect and then diagnose the location of faults. Tools nominate components, so that a rank order of most likely candidates can be generated. This modular approach allows existing proven FDD methods (e.g., vibration analysis, FMEA) to be incorporated and to add confidence to the conclusions. Illustrative performance is provided working in real time during deployments with the RAUVER hover capable AUV as an example of the class of automated system to which this approach is applicable. © 2007 Wiley Periodicals, Inc.
Satellites and the isdn
Authors: Lewis John 
Published: July 2007

AbstractThis paper addresses the question of integrating satellites within the ISDN, concentrating on PSTN application. After a brief look at the role satellites have played to date in international telecommunications, and the new environment that ISDN will bring, an examination is made of the work done by CCITT on the transmission aspects of ISDN. This is followed by a look at the main features of digital satellite systems at the present time, including transmission performance as defined by CCIR, and a critical comparison is made with ISDN requirements including an indication of how error performance may need improving. The paper concludes with a discussion of how satellite system operators might respond to the demands of the ISDN.
An introduction to testing techniques in the intelsat tdma/dsi system part 2: satellite system operations guide (ssog) tests
Authors: Colby R. J. , Parthasarathy R. , Stimson A. L. 
Published: July 2007

AbstractThis paper is the second of a four‐part series addressing the testing and alignment techniques to be used in the INTELSAT TDMA/DSI system. In the first part,1 the salient characteristics of the overall TDMA/DSI system were presented, together with a discussion of the fundamental requirements for testing and alignment. In this second part, INTELSAT's satellite system operations guide (SSOG) for TDMA is introduced and the principles of testing embodied in the SSOG tests are discussed. In particular, the impact of the unique TDMA access discipline on testing is examined. The third part will address the design of the specialized test equipment required. The fourth part will complete the series with a report on the operational experience gained in the initial stages of the TDMA implementation within the INTELSAT system.
Satellite switch state time plan control
Authors: Campanella S. J. , Inukai T. 
Published: July 2007

AbstractThis paper describes the basic control features of a typical satellite switch system, such as INTELSAT VI. Factors are addressed pertaining to the data format that is used to express the switch plan, the timing control of the switch states comprising the satellite switch frame, the transmission of the switch plan to the satellite, storage and execution of the switch plan on board, and the coding of switch plan data for protection from radiation‐induced bit errors. Also, the implementation used to achieve precision control of the on‐board clock is discussed, and the influence of clock control variation on all the terrestrial interfaces that participate in the system is demonstrated. Finally, the method for achieving network‐wide coordinated switch state time plan/TDMA burst time plan changes, which are essential in an operational satellite‐switched (SS)‐TDMA system, is discussed.
Application of 32 and 16 kb/s speech encoding techniques to digital satellite communications
Authors: Yatsuzuka Y. , Yato F. , Kurematsu A. 
Published: July 2007

AbstractThis paper describes the performance of various voice encoding techniques at 32 and 16 kb/s for applying to digital satellite communication systems. The subjective performances of adaptive differential PCM (ADPCM), adaptive predictive coding (APC), subband coding (SBC) and adaptive delta modulation (ADM) are compared under various satellite channel environments, that is, random and burst channel errors in satellite link and an ambient noise in the ship‐to‐shore direction in a maritime satellite channel. The performance of the voiceband data at 4·8 and 2·4 kb/s is also evaluated for these coders. ADPCM encoding at 32 kb/s is very attractive for conventional fixed satellite systems, keeping the equivalent quality to 64 kb/s PCM. On the other hand, APC encoding at 16 kb/s is also most suitable for maritime satellite communication systems at the sacrifice of a small degradation of speech quality.