bluuebunny/crossref_metadata_2025_split huggingface dataset:
The role of evaporation in the energy balance of an open‐air scaled urban surface
Authors: Pearlmutter D. , Krüger E. L. , Berliner P. 
Published: August 2008

AbstractSurface evaporation is an important component of the urban energy balance, and its role in arid‐zone cities may significantly differ from that observed in more temperate regions. However, the quantification of evapotranspiration is difficult in a complex urban setting, given the heterogeneity of the terrain and its various dry and wet elements. Here an open‐air scaled urban surface (OASUS) is employed to quantify latent heat flux as a function of the surface area available for evaporation and the three‐dimensional (3‐D) urban geometry. The OASUS model consists of an extensive urban‐like building/street array located in an arid Negev region of southern Israel (30.8°N, 480 m above sea level). Measurements were carried out during the summer month of August, and flux partitioning was analysed using evaporation pans of varying surface areas embedded in arrays of varying height. Results indicated that the increase in latent heat removal with respect to equivalent ‘vegetative’ surface area was nearly linear. Increasing latent heat flux with ‘vegetated fraction’ was offset in approximately equal measure by decreases in storage and turbulent sensible heat flux. The proportion of the radiant energy budget represented by evaporative heat loss was also linked to the 3‐D geometry of the array, increasing linearly with the ratio between vegetative cover and the ‘complete’ urban surface area. Copyright © 2008 Royal Meteorological Society
Timing of the late Quaternary glaciation in the Andes from ∼15 to 40° S
Authors: Zech Roland , May Jan‐Hendrik , Kull Christoph , Ilgner Jana , Kubik Peter W. , Veit Heinz 
Published: August 2008

AbstractThe Central Andes play a pivotal role for glacier and climate reconstruction along the American Pole–Equator–Pole transect. Nevertheless, knowledge about late Quaternary palaeoenvironmental changes in this region is extremely limited. With the advent and application of surface exposure dating during the last few years, the establishment of more detailed glacial chronologies could provide important insights into forcings and mechanisms of glaciation and climate change. This paper reviews previously published exposure ages and compares them with independent age control on glacial chronologies and with information about the palaeohydrological conditions. Although available data are still very limited and there are remaining systematic uncertainties related to surface exposure dating, the following simplified palaeoglacial/palaeoclimate model is presented to serve as a testable hypothesis for future studies. (i) Glaciers in the humid tropical Andes were mainly temperature sensitive and therefore advanced during temperature minima. Advances are dated to 20–25 ka, ∼15 ka and 11–13 ka, i.e. synchronous to the global Last Glacial Maximum (LGM), the Heinrich event 1 and the Younger Dryas/Antarctic Cold Reversal. (ii) Further south and west, precipitation decreases and glaciers therefore become more precipitation sensitive. Maximum or at least prominent glacial advances as far south as 30° S are dated into the Lateglacial, i.e. synchronous with lake transgression phases (Tauca: 14–18 ka, and Coipasa: 11–13 ka). (iii) Between ∼30 and 40° S, glaciers reached their maximum extent much earlier during the pre‐LGM (∼35–40 ka). This is attributed to a northward shift and/or intensification of the westerlies, whereas conditions during the global LGM were too dry to allow for significant glacial advances. (iv) South of 40°, glaciers become temperature sensitive again and reached their maximum accordingly synchronous to the global LGM. Copyright © 2008 John Wiley & Sons, Ltd.
Glacial dynamics in southernmost South America during Marine Isotope Stage 5e to the Younger Dryas chron: a brief review with a focus on cosmogenic nuclide measurements
Authors: Kaplan Michael R. , Moreno Patricio I. , Rojas Maisa 
Published: August 2008

AbstractThe timing of major glacial changes between Marine Isotope Stage (MIS) 5e and the Younger Dryas chron (YD) in southern South America is reviewed. Focus is placed on studies that use cosmogenic nuclide measurements. However, other dated records and modelling results are also discussed to provide the broader glacial geological context. Limits on the state of glacial geologic knowledge are examined and suggestions are made as to how some of these can be addressed in future studies. Studies show that on the east side of the Andes at Lago Buenos Aires (45° S) there is evidence indicating that following a MIS 6 glaciation ice was less extensive during MIS 4 than MIS 2. In contrast, on the west side of the Andes in the Chilean Lake District area, MIS 4 ice may have been more extensive than during MIS 2. Although Patagonia experienced an MIS 2 glaciation broadly in phase with that in other areas around the globe, there are differences in glacial histories between areas on millennial timescales. Climate reversals are evident in many records between ca. 17 and 10 ka. The timing of such Lateglacial activity, which included less extensive advances than during the local Last Glacial Maximum (LGM), varies somewhat between areas. This could be due to the relative influence of middle‐ to high‐latitude climatic regimes. At present, chronological uncertainties prevent confident assignment of cosmogenic ages for glacial events at the millennial timescale and defining associated climate variability between different study areas. Copyright © 2008 John Wiley & Sons, Ltd.
Raman spectroscopic study of the selenite mineral: ahlfeldite, NiSeO3·2H2O
Authors: Frost Ray L. , Keeffe Eloise C. 
Published: August 2008

AbstractRaman spectroscopy has been used to study the selenite mineral ahlfeldite. A comparison is made with the Raman spectra of chalcomenite, cobaltomenite and clinochalcomenite. Selenite minerals are characterised by the position of the symmetric stretching mode which is observed at higher wavenumbers than the anti‐symmetric stretching mode. The selenite ion has C3v symmetry and four modes, 2A1 and 2E. These modes are observed at 813, 472 cm−1 (A1) and 685, 710, 727 and 367 and 396 cm−1 (E). Bands assigned to the water stretching vibrations are observed for ahlfeldite at 3385 cm−1, for chalcomenite at 2953, 3184 and 3506 cm−1 and for clinochalcomenite at 2909, 3193 and 3507 cm−1. A comparison of the Raman spectra of chalcomenite, clinochalcomenite and cobaltomenite is made. The position of these bands enabled hydrogen bond distances in the selenite structure to be estimated. Hydrogen bond distances for ahlfeldite, chalcomenite and clinochalcomenite were determined to be similar. Copyright © 2008 John Wiley & Sons, Ltd.
Preparation and SERS study of triangular silver nanoparticle self‐assembled films
Authors: Zeng Jianbo , Jia Huiying , An Jing , Han Xiaoxia , Xu Weiqing , Zhao Bing , Ozaki Yukihiro 
Published: August 2008

AbstractWe report a novel type of self‐assembly of triangular silver nanoparticles onto a quartzose substrate with a monolayer of poly(diallyldimethylammonium chloride). Attractive electrostatic interactions between the negatively charged nanoparticles and the positively charged polyelectrolyte are responsible for the self‐assembly. Surface morphology and optical properties of the triangular, silver nanoparticle self‐assembly film were studied by atomic force microscopy (AFM) and ultraviolet–visible (UV–vis) spectroscopy, and then compared with those of the spherical silver nanoparticle self‐assembly film. It was found from the AFM measurement that most of the spherical and triangular silver nanoparticles were assembled directly onto the substrate rather than aggregated to each other. The UV–vis spectrum of the triangular, silver nanoparticle self‐assembled film is quite different from that of the colloid of silver nanoparticles. A peak at 697 nm assigned to the in‐plane dipole plasmon resonance shows a blue shift by 55 nm after the triangular silver nanoparticles are immobilized onto the substrate. The triangular, silver nanoparticle self‐assembly film can be used as a surface‐enhanced Raman scattering (SERS) substrate, and Rhodamine 6G as a Raman probe to evaluate its enhancement ability. It was found that the enhancement ability of the triangular, silver nanoparticle film is remarkable but somewhat lower than that of the spherical silver nanoparticle film. The reason for this is discussed from the point of electromagnetic mechanism and chemical mechanism. Copyright © 2008 John Wiley & Sons, Ltd.
Kunststoffschweißen mit dem Laser
Authors: Hänsch Dirk , Salein Caroline 
Published: August 2008

AbstractImmer noch wird das Kunststoffschweißen mit dem Laserstrahl als neues, innovatives Fügekonzept deklariert. Doch so jung ist diese Technologie nicht mehr. Seit nunmehr zehn Jahren findet der Laserstrahl Anwendung in der industriellen Serienproduktion, hat sich sowohl in Klein‐ als auch in Großserien bewährt und etabliert. Aufgrund seiner technologischen und wirtschaftlichen Vorteile läst das Verfahren nach und nach die herkömmlichen Verbindungsmethoden für Kunststoffe ab und erobert neue Anwendungsbereiche.
Laserdurchstrahlschweißen von Thermoplasten
Authors: Roesner Andreas , Boglea Andrei , Olowinsky Alexander 
Published: August 2008

AbstractDank seiner Vorteile hat sich das Laserschweißen von Kunststoffen zu einem etablierten Fügeverfahren entwickelt und es ersetzt mehr und mehr die bisher üblichen Fügeverfahren. Neue Entwicklungen beim Laserdurchstrahlschweißen ermöglichen nun das Überschreiten bisheriger Grenzen und eröffnen diesem Schweißverfahren weitere Anwendungsfelder.
Neue Halbleiterlaser‐Wellenlängen für das Kunststoffschweißen
Authors: Neukum Jörg 
Published: August 2008

AbstractMittlerweile finden sich viele Hochleistungs‐Diodenlaser‐Systeme im industriellen Einsatz, meist jedoch bei Standardwellenlängen zwischen 808 und 980nm. Im Leistungsbereich bis einige hundert Watt sind dies meist thermische Anwendungen im Bereich des Lötens und des Kunststoffschweißens. In Kombination mit Galvo‐Scannern und Pyrometern sind hierbei sowohl geregelte, als auch selektive Prozesse mit Qualitätsdokumentation möglich. Halbleiter‐Laserdioden mit Wellenlängen im Bereich von 1,4 bis 2 μm eröffnen neue Anwendungen in der Materialbearbeitung – insbesondere beim Kunststoffschweißen.
Maskenschweißen von Thermoplasten mittels Laserstrahlung
Authors: Thielen Carsten 
Published: August 2008

AbstractViele Innovationen entstehen durch Kundenanforderungen. Oft werden diese Anforderungen durch den Stand der Technik limitiert. Beim Maskenschweißen von Thermoplasten behinderte viele Jahre die optische Leistung der Diodenlaser die Entwicklung des schnellen Verschweißens von kleinen Nähten und großen Strukturen für die Mikrotechnik und Fluidik. Die jetzt erreichten Leistungsklassen haben diese Limitierung für das Maskenschweißen aufgehoben, finden verstärkt Anwendung in der Industrie und treiben weitere Innovationen wie das High Speed Welding in den Markt.
Picosecond Micromachining Update
Authors: Dorman Chris , Schulze Matthias 
Published: August 2008

AbstractMany industries currently use lasers for drilling, cutting, scribing and contouring materials as diverse as silicon, metals and plastics, with features as small as a few tens of microns. Traditionally, this precision micromachining has been powered by DPSS (diode pumped solid state) or excimer lasers with nanosecond pulse durations, but there is a growing need for even higher precision and resolution. While shorter pulsewidths can yield higher resolution, superior edge quality, and eliminate peripheral thermal effects, drawbacks in existing ultrafast laser technology have limited its use to a few specialty applications. In this article we describe a new type of laser that delivers picosecond output, and combines the simplicity of a fiber laser with the high pulse energy characteristics of a freespace laser. We then discuss applications that can benefit from the unique output, including microelectronics and photovoltaic manufacturing.
Grundlagen der Faserkopplung von Diodenlasern
Authors: Wolf Jürgen , Werner Ekkehard 
Published: August 2008

AbstractHochleistungsdiodenlaser werden als Einzelemitter, Laserbarren und Stacks hergestellt. Die Anwendungen, wie zum Beispiel das Pumpen von Faserlasern, erfordern oft eine hohe Strahlqualität, die sich durch Einkopplung des Laserlichts in eine Faser erreichen lässt. In diesem Beitrag werden unterschiedliche Konzepte für Faserkopplungen dieser Lasertypen vorgestellt. Die Palette der darauf basierenden Produkte umfasst Faserdurchmesser von 50 bis 600 μm und Ausgangsleistungen bis zu 600 Watt.
Selective Laser Melting
Authors: Wiesner Andreas 
Published: August 2008

AbstractMithilfe der Strahlschmelztechnologie lassen sich räumliche Strukturen Schicht für Schicht aus einem pulverförmigen metallischen Ausgangsstoff herstellen. Dabei wird die Energie eines Strahls vom Pulver absorbiert und führt zu einem lokal begrenztem Verschmelzen von Partikeln. Nahezu jede dreidimensionale Form lässt sich auf diese Weise direkt aus Konstruktionsdaten herstellen. Eine Verfahrensvariante, die im Folgenden näher betrachtet wird, ist das Selektive Laser Melting (SLM).
Minimizing superficial thermal injury using bilateral cryogen spray cooling during laser reshaping of composite cartilage grafts
Authors: Chang Cheng‐Jen , Cheng Sally M.H. , Chiu Lynn L. , Wong Brian J.F. , Ting Keen 
Published: August 2008

AbstractComposite cartilage grafts were excised from New Zealand rabbit ears. Flat composite grafts (of cartilage and overlying skin graft on both surfaces) were obtained from each ear and cut into a rectangle measuring 50 mm by 25 mm (x by y) with an average thickness of approximately 1.3 mm (z), skin included. Specimens were manually deformed with a jig and maintained in this new position during laser illumination. The composite cartilage grafts were illuminated on the concave surface with an Nd:YAG laser (1,064 nm, 3 mm spot) at 10 W, 20 W, 30 W, 40 W, 50 W. Cryogen spray cooling (CSC) was applied to both exterior (convex) and interior (concave) surfaces of the tissue to reduce thermal injury to the grafts. CSC was delivered: (1) in controlled applications (cryogen released when surface reached 40°C, and (2) receiving only laser at above wattage, no CSC [representing the control group]. The specimens were maintained in a deformation for 15 minutes after illumination and serially examined for 14 days. The control group with no CSC caused injury to all specimens, ranging from minor to full thickness epidermal thermal injury. Although most levels of laser and CSC yielded a high degree of reshaping over an acute time period, after 14 days specimens exposed to 30 W, 40 W, 50 W retained shape better than those treated at 10 W and 20 W. The specimens exposed to 50 W with controlled CSC retained its new shape to the highest degree over all others, and thermal injury was minimal. In conclusion, combinations of laser and CSC parameters were effective and practical for the reshaping of composite cartilage grafts. Lesers Surg. Med. 40:477–482, 2008. © 2008 Wiley‐Liss, Inc.
In vivo nonmelanoma skin cancer diagnosis using Raman microspectroscopy
Authors: Lieber Chad A. , Majumder Shovan K. , Ellis Darrel L. , Billheimer D. Dean , Mahadevan‐Jansen Anita 
Published: August 2008

AbstractBackground and ObjectivesNonmelanoma skin cancers, including basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), are the most common skin cancers, presenting nearly as many cases as all other cancers combined. The current gold‐standard for clinical diagnosis of these lesions is histopathologic examination, an invasive, time‐consuming procedure. There is thus considerable interest in developing a real‐time, automated, noninvasive tool for nonmelanoma skin cancer diagnosis. In this study, we explored the capability of Raman microspectroscopy to provide differential diagnosis of BCC, SCC, inflamed scar tissue, and normal tissue in vivo.Study DesignBased on the results of previous in vitro studies, we developed a portable confocal Raman system with a handheld probe for clinical study. Using this portable system, we measured Raman spectra of 21 suspected nonmelanoma skin cancers in 19 patients with matched normal skin spectra. These spectra were input into nonlinear diagnostic algorithms to predict pathological designation.ResultsAll of the BCC (9/9), SCC (4/4), and inflamed scar tissues (8/8) were correctly predicted by the diagnostic algorithm, and 19 out of 21 normal tissues were correctly classified. This translates into a 100% (21/21) sensitivity and 91% (19/21) specificity for abnormality, with a 95% (40/42) overall classification accuracy.ConclusionsThese findings reveal Raman microspectroscopy to be a viable tool for real‐time diagnosis and guidance of nonmelanoma skin cancer resection. Lesers Surg. Med. 40:461–467, 2008. © 2008 Wiley‐Liss, Inc.
Anti‐Inflammatory effects of low‐level laser therapy (660 nm) in the early phase in carrageenan‐induced pleurisy in rat
Authors: Boschi Emerson S. , Leite Carlos E. , Saciura Vasyl C. , Caberlon Eduardo , Lunardelli Adroaldo , Bitencourt Shanna , Melo Denizar A.S. , Oliveira Jarbas R. 
Published: August 2008

AbstractBackground and ObjectiveIn the classic model of pleurisy there is little evidence about the anti‐inflammatory effects of low‐level laser therapy (LLLT) as well the dosage characteristics, such as wavelength, total energy, number and pattern of treatment. In this study we investigated the potential effects of LLLT on modulating the pro‐inflammatory and anti‐inflammatory mediators of acute inflammation in a rat pleurisy model.Study Design/Materials and MethodsA sample of 48 female Wistar rats were divided into control and experiential groups. An inflammation was induced by carrageenan (0.2 ml) injected into the pleural cavity. At 1, 2, and 3 hours after induction a continuous wave (20 mW) diode laser of the InGaAlP (660 nm) type was used in the four laser groups with different doses and treatment patterns. One group received a single dose of 2.1 J and the other three groups received a total energy of 0.9, 2.1, and 4.2 J. Four hours later the exudate volume, total and differential leukocytes, protein concentration, NO, IL‐6, IL‐10, TNF‐α, and MCP‐1 were measured from the aspirated liquid.ResultsAll the treatment patterns and quantity of energy studied show significant reduction of the exudate volume (P<0.05). Using energy of 0.9 J only NO, IL‐6, MCP‐1 and IL‐10 are significantly reduced (P<0.05). On the other hand, higher energies (2.1 and 4.2 J) significantly reduce all variables independently of the treatment pattern. The neutrophil migration has a straight correlation with the TNF‐α (r = 0.551) and NO (r = 0.549) concentration.ConclusionsLLLT—660 nm induced an anti‐inflammatory effect characterized by inhibition of either total or differential leukocyte influx, exudation, total protein, NO, IL‐6, MCP‐1, IL‐10, and TNF‐α, in a dose‐dependent manner. Under these conditions, laser treatment with 2.1 J was more effective than 0.9 and 4.2 J. Lesers Surg. Med. 40:500–508, 2008. © 2008 Wiley‐Liss, Inc.
Unipolar versus bipolar radiofrequency treatment of rhytides and laxity using a mobile painless delivery method
Authors: Alexiades‐Armenakas Macrene , Dover Jeffrey S. , Arndt Kenneth A. 
Published: August 2008

AbstractBackgroundPrevious studies have shown that radiofrequency (RF) energy is a safe and effective treatment for rhytide‐reduction.ObjectiveThis randomized, blinded, split‐face study assesses the safety and efficacy of the unipolar versus bipolar handpieces on an RF device with a mobile delivery method for the treatment of rhytides and laxity using quantitative grading.MethodsIn this randomized, blinded, split‐face design study, 10 subjects (aged 18–75 years) with a clinically observable excess of rhytides and laxity (minimum grade 2 out of 4) on the face received four treatments at 1‐week intervals with random assignment of unipolar RF to one side and bipolar RF to the contralateral side. Each side received approximately four passes per treatment delivered in a mobile continuous manner. Results were evaluated by two blinded investigators of photographs employing a comprehensive 4‐point grading scale at baseline, and 1‐ and 3‐month follow‐up visits after the final treatment.ResultsAll subjects completed and responded to treatment. The blinded evaluations demonstrated the following mean percent improvements in grading scores of rhytides and laxity: for the unipolar side 6.0±4.6% and 4.6±4.8% versus the bipolar side 4.4±2.5 and 7.3±3.5%. The degree of improvement approached but did not achieve statistical significance for either handpiece, but demonstrated a trend toward improvement (P = 0.5599 unipolar vs. 0.1108 bipolar). The treatment was painless (rated 0 out of 10 by all subjects) and side effects included minimal erythema which resolved within 1–3 hours. No crusting, dyspigmentation or scarring was observed.ConclusionThis randomized, split‐face study with blinded evaluations employing a quantitative grading scale demonstrated that minimal pass, mobile energy delivery serial treatments with either the unipolar or bipolar handpieces of a novel RF device appears to safe and painless. Each handpiece demonstrated minimal clinical efficacy which was not statistically significant, but with a trend toward improvement in rhytides and laxity of facial skin. Lesers Surg. Med. 40:446–453, 2008. © 2008 Wiley‐Liss, Inc.
Highly Conductive Core–Shell Nanocomposite of Poly(N‐vinylcarbazole)–Polypyrrole with Multiwalled Carbon Nanotubes
Authors: Maity Arjun , Sinha Ray Suprakas 
Published: August 2008

AbstractIn this communication, the synthesis, characterization, and properties of highly conductive core–shell nanocomposites of poly(N‐vinylcarbazole) (PNVC)–polypyrrole (PPY) copolymers with multi‐walled carbon nanotubes (MWCNTs) are described. A unique free‐radical coupling reaction between PNVC and PPY cation radicals in chloroform solvent, using feric chloride as an oxidant, in the presence of suspended MWCNTs in the reaction medium, was used for the synthesis of nanocomposite. Field‐emission scanning and transmission electron microscopy studies showed the formation of the core–shell nanocomposite. Raman spectrocopy results as well as thermogravimetric analysis supported the electron microscopic observations. The resulting PNVC–PPY copolymer‐coated MWCNTs showed an unprecedentedly increased value of direct electrical conductivity (bulk) compared to the conductivity of all samples even with pure MWCNTs.magnified image