bluuebunny/crossref_metadata_2025 huggingface dataset:
Theorie über die Gitterströmung beliebig geformter Flügel‐ profile mit großen Wölbungs‐ und Dicken‐Verhältnissen
Authors: Murai H.
Published: May 2007

Es wird hier eine Theorie der Eigenschaften der Flügelprofile in der Gitterreihe mit verhältnismäßig kleinen Flügelteilungen behandelt. Durch eine numerische Berechnung der Flügelprofileigenschaften einer Gasturbinenleitschaufel ließ es sich bestätigen, daß die durch diese Theorie gewonnenen Ergebnisse mit den Versuchswerten von F. Numachi und T. Kurokawa befriedigend in übereinstimmung zu bringen sind.
Über ein ebenes Distorsionsproblem
Authors: Hieke Max
Published: May 2007

Die bisherige Behandlung von Selbstspannungsproblemen bei unstetiger Dichteänderung beschränkte sich auf einen Sonderfall, bei dem die Dichteänderung durch eine in einem Kreissektor konstante Temperatur erzeugt wird. Jetzt wird das gleiche Integrationsverfahren auf den Fall einer in einem Kreisabschnitt konstanten Temperatur angewandt. Damit wird eine Erweiterung der physikalischen Vergleichsmöglichkeiten gewährt.
Berechnung der Stabilität mehrfeldriger Stäbe mit Hilfe von Matrizen
Authors: Schnell W.
Published: May 2007

Die kritische Last für mehrfeldrige Stäbe auf elastischen Stützen wird aus einer zweireihigen Unterdeterminante eines vierreihigen Matrizenproduktes ermittelt; die einzelnen Felder und Stützen können dabei verschiedenen Abmessungen haben. Durch die Verwendung von „Determinantenmatrizen”︁ werden die Sonderfälle starrer Stützen und idealer Gelenke in das Lösungsverfahren eingeordnet.
Die Anwendung des Matrizanten bei Eigenwertaufgaben
Authors: Hellman O.
Published: May 2007

Die lineare Differentialgleichung oder eine Gruppe von linearen Differentialgleichungen einer Eigenwertaufgabe wird in bekannter Weise in eine Gruppe von erstgradigen Differentialgleichungen zurückgeführt die an Hand des sog. Matrizanten aufgelöst werden kann. Vermittels der Randbedingungen gewinnt man jetzt eine Gleichung für die Eigenwerte. In einigen praktischen wichtigen Fällen werden Methode zur Berechnung des Matrizanten hergeleitet.
Fehlerabschätzung für die zweite Randwertaufgabe der ebenen Potentialtheorie
Authors: Bertram G.
Published: May 2007

Es wird ein aus der Greenschen Lösungsdarstellung für den Kreis unter Verwendung konformer Abbildungen gewonnenes Fehlerabschätzungsverfahren für die zweite Randwertaufgabe der ebenen Potentialtheorie erläutert; dieses gestattet unter geeigneten Voraussetzungen die Abschätzung des maximalen Fehlerbetrages einer aus einem beliebigen Approximationsverfahren gewonnenen harmonischen Näherung. Es folgen Anwendungen und weitere Abschätzungssätze.
Das ungelöste Hauptproblem der endlichen Elastizitätstheorie
Authors: Truesdell C.
Published: May 2007

Die bemerkenswerten Fortschritte der letzten Jahre in der endlichen Elastizitätstheorie verdankt man der Vermeidung spezieller Ansätze. Die Lösungen, ob exakt oder numerisch, sind für beliebige Formänderungsarbeitsfunktionen Σ gültig. In der gewöhnlichen linearen Theorie ist Σ eine quadratische Form, die aber schon hier nicht völlig willkürlich sein darf, sondern positive definit sein muß. Vor drei Jahren hat der Verfasser die entsprechende Frage in der endlichen Theorie ‐ nämlich welchen Einschränkungen Σ unterworfen werden muß ‐ aufgeworfen und gleichzeitig einige Ungleichungen, die er als notwendige, aber nicht als hinreichende Bedingungen vermutete, vorgeschlagen. In diesem Bericht faßt er die späteren Untersuchungen in dieser Frage zusammen.
Approximation von Funktionen bei einer und bei mehreren unabhängigen Veränderlichen
Authors: Collatz L.
Published: May 2007

Eine Funktion g(x1,…, xn) soll durch eine Linearkombination Q aus Funktionen u1,…, up in einem Bereich B so angenähert werden, daß dort das Maximum des Betrages der Abweichung ϵ = Q – g möglichst klein ausfällt (Tschebyscheff sches Problem). ϱ sei das Minimum von |ϵ|max. Es werden einfache Methoden entwickelt, die in vielen Fällen ϱ in Schranken einzuschließen gestatten, so daß man beurteilen kann, wie gut man g mit den p gegebenen Funktionen überhaupt annähern kann und wie weit man mit einer vorliegenden Näherung noch von der optimalen entfernt ist. Die Methoden werden auf Randwertaufgaben bei partiellen Differentialgleichungen angewendet.
Elementarer Existenzbeweis für die Grenzschichtströmung an einer Klasse rotierender Körper
Authors: Geis Theo
Published: May 2007

Zur Ermittlung der Grenzschichtströmung an Drehkörpern gewisser Gestalt, die in sonst ruhender Flüssigkeit um ihre Achse rotieren, hat man das System von gewöhnlichen Differentialgleichungen F‴ + cGF″ + 2 G′ (1 − F′) = 0; G‴ + cGG″ ‐ G′2 + (1 − F′)2 = 0 unter den Randbedingungen F′(0) = G(0) = G′(0) = 0, F′ (∞) = 1, G′(∞) = 0 zu lösen. Die Existenz mindestens einer Lösung des Randwertproblems wird in der nachfolgenden Arbeit auf elementare Wege bewiesen unter Verallgemeinerung einer von R. Iglisch erstmals angewandten Methode.
Über das Differenzenverfahren bei nichtlinearen Randwertaufgaben I
Authors: Schröder Johann
Published: May 2007

Es werden Iterationsverfahren zur Lösung der Differenzengleichungen für Randwertaufgaben bei gewöhnlichen Differentialgleichungen zweiter Ordnung beschrieben.
Über die Wirbelstraßen von geringster Instabilität
Authors: Domm U.
Published: May 2007

Es wird gezeigt, daß die zuerst von Maue und Dolaptschiew angegebenen zweiparametrigen‐Wirbelstraßen in bezug auf eine Zwei‐Gruppenstörung nach Schmieden instabil sind.
Some simple problems of flexure ‐ Part I
Authors: Mohan R.
Published: May 2007

Mittels einer einfachen Methode werden zwei Biegungsprobleme gelöst. Das erste Problem betrifft einen gleichförmigen Balken mit einem hufeisenförmigen Querschnitt, der durch zwei konfakale Ellipsen und einen Teil ihrer kleineren Achse begrenzt wird. Das zweite Problem bezieht sich auf einen gleichförmigen Balken, dessen Querschnitt von einer Parabel und einer Geraden begrenzt wird. In beiden Fällen wird angenommen, daß die am Ende des Balkens angreifende Last senkrecht zur geraden Kante wirkt.
Stress in a Plate Containing Infinite Parallel Rows of Holes
Authors: Saito Hideo
Published: May 2007

This paper deals with the stress distribution that occurs in a plate perforated by infinite rows of circular holes with centres placed periodically along the horizontal and vertical lines. The plate is in a state of generalized plane stress and subjected to uniform tension in a constant direction. The values of stresses at the edge of holes are computed.
Ein Verfahren zur Bildung von Matrizanten
Authors: Hellman O.
Published: May 2007

Eine Gruppe von erstgradigen Differentialgleichungen, die man in Matrizenform geschrieben hat, löst man bekanntlich an Hand des sog. Matrizanten auf. Man teilt die Koeffizientenmatrix A des betreffenden Differentialgleichungssystems in Untermatrizen so, daß die Untermatrizen, die auf der Diagonale liegen, quadratisch werden. Mit Hilfe der Störungsrechnung bildet man jetzt den Matrizanten für A. In der hergeleiteten Form sind die Matrizanten der obenerwähnten diagonalen Untermatrizen die Hauptbauteile, die die übrigen zwei Untermatrizen miteinander „koppeln”︁. Als Anwendung wird das Problem der gekoppelten Biege‐ und Torsionsschwingungen betrachtet.
The Forces on a Thin Aerofoil in Slightly Parabolic Shear Flow
Authors: Jones E. E.
Published: May 2007

The aerodynamic characteristics of a thin cambered aerofoil are determined, when the aerofoil is set at incidence in a shear flow of incompressible inviscid fluid. First order effects are deduced assuming that the deviation from uniform flow is small, the velocity profile being parabolic in form.
Zur numerischen Auswertung mehrdimensionaler Integrale
Authors: Albrecht J. , Collatz L.
Published: May 2007

Zur Herleitung von Formeln für die numerische Auswertung mehrdimensionaler Integrale nach der Methode der Taylor Entwicklung werden als wichtige Hilfsmittel u.a. gewisse partielle Differentialoperatoren eingeführt und genauer untersucht, mit denen sich die bei den Taylor Entwicklungen auftretenden partiellen Ableitungen übersichtlich zusammen fassen lassen. Für eine Anzahl häufiger vorkommender Bereiche werden Auswertungsformeln zusammengestellt. Es wird eine Fehlerabschätzungsmethode mitgeteilt und für Quadrat und Würfel ausführlich (u. a. durch Angabe von Formeln mit optimalen Schranken) erläutert.
Zur Entstehung von Längswirbeln in Grenzschichten
Authors: Schultz‐Grunow F.
Published: May 2007

Längswirbel in Grenzschichten an ebenen Wänden stellen in erster Näherung neutrale Störungen dar. Daher ist ihre Entstehung von Interesse. Eine einzelne Rauhigkeit oder auch ein in der Grenzschicht befindlicher Körper erzeugt allein durch Verdrängungswirkung solche Wirbel, über die sich in nichtstationären Fällen als Anfahrwirbel Querwirbel überlagern. Auf das Wirbelsystem läßt sich die Tragflügeltheorie anwenden. Der Einfluß der Längswirbel auf die Turbulenzentstehung wird untersucht. Auf eine weitere Ursache für Längswirbel durch Stauwirkung wird hingewiesen.
On the Hydrodynamic Stability of Curved Laminar Flows
Authors: Lessen M.
Published: May 2007

The stability of curved laminar compressible flows is examined, and it is found that instabilities in the flow fields about bodies moving at high speed may exist under certain circumstances.

The general disturbance equations are derived and simplified cases are discussed. Whereas in the case of incompressible flows, the instability is due to the kinematics of the flow field, for the compressible case, thermodynamic factors are also of importance.
Berechnung der zu einer vorgegebenen Differenzenfunktion beliebig hoher Ordnung nach der Methode der kleinsten Quadrate gehörigen Stammfunktion
Authors: Hahn E.
Published: May 2007

Es werden die n Funktionswerte fv = f(xv) in den Punkten xv des Intervalls x1 > xv > xn als variabel und diejenigen Werte fv außerhalb des Intervalls als fest vorgegeben betrachtet. Die von den variablen fv abhängigen n + p zentralen Differenzen p‐ter Ordnung (δPf)j mit \documentclass{article}\pagestyle{empty}\begin{document}$ 1\,-\-\-\,\frac{p}{2}\, \le \,i\, \le \,n\, + \,\frac{p}{2} $\end{document} werden nun ihrerseits als Variable yj betrachtet. Es wird nach denjenigen fv‐Werten des Variabilitätsintervalls gefragt, für die der Ausdruck magnified image ein Minimum hat. Es wird eine Rekursionsformel abgeleitet, die diese fv‐Werte zu berechnen gestattet.
Experimentelle Untersuchung über harmonische Schwingungen in rotierenden Flüssigkeiten
Authors: Oser Hansjörg
Published: May 2007

Beschreibung einer Apparatur, welche die Charakteristiken nachzuweisen gestattet, die bei erzwungenen, kleinen harmonischen Schwingungen in einer gleichförmig rotierenden, reibungsfreien und inkompressiblen Flüssigkeit entstehen. Die beobachteten Erscheinungen stehen in Übereinstimmung mit den theoretischen Ergebnissen.
Ein Iterationsverfahren zur näherungsweisen Lösung von Matrizendifferentialgleichungen
Authors: Bajcsay P. , Lovass‐Nagy V.
Published: May 2007

Die Formel für die Lösung einer linearen Matrizen‐Differentialgleichung ist für die numerische Rechnung besonders bequem, wenn die kanonische Darstellung der Koeffizientenmatrix explizit bekannt ist. Diese Formel ist jedoch schwierig anzuwenden, wenn sich die Matrix nicht auf Diagonalform bringen läßt oder ihre kanonische Gestalt unbekannt ist. Aufgabe der vorliegenden Arbeit ist es, ein konvergentes Iterationsverfahren anzugeben, das bei einer beliebigen Koeffizientenmatrix anwendbar ist. Dabei wird die gegebene Matrix in eine Summe aus einer Matrix 𝔄 mit explizit bekannter kanonischer Darstellung und einer Matrix 𝔅 von möglichst kleiner Norm zerlegt. Die auf diese Weise erhaltene Lösung erscheint in einer nach den Rechtseigenvektoren von 𝔄 entwickelten Form.
Shock Wave Propagation in an Infinitely Electrically Conductive Gas with Transverse Magnetic Field and Gravitation
Authors: Pai S. I.
Published: May 2007

The behavior of a one dimensional strong shock wave propagating itself in an infinitely electrically conductive gas in the presence of a transverse magnetic field and a field of gravity has been analyzed by means of the Lagrangian method. The effect of the magnetic field as to increase the speed of the shock wave and the domain influenced by the shock wave.

A brief description of the characteristics of the same problem from the Eulerian point of view is also given.
Zur Stabilität der Couette‐Strömung
Authors: Schultz‐Grunow F.
Published: May 2007

Obwohl die Couette‐Strömung bei rotierendem Außen‐ und ruhendem Innenzylinder als Experimentum Crucis der Stabilitätstheorie der Grenzschichten gilt, ist ihre Stabilität noch nicht geklärt. Es wird gezeigt, daß sich das Stabilitätsproblem exakt behandeln läßt. Dabei wird Stabilität gefunden. Daß trotzdem die früheren Versuche Turbulenz ergaben, wird durch Nebeneffekte erklärt auf Grund eigener Versuche, mit sichtbar gemachter Strömung.
Centre of flexure of a beam of orthotropic material having a section bounded by an ellipse and its major axis
Authors: Chakravorti A.
Published: May 2007

In this paper the problem of finding the centre of flexure of a beam of orthotropic material having a section bounded by an ellipse and its major axis is discussed. Here the load is supposed to act parallel to the straight edge.
The effect of prenatal X‐irradiation on the developing cerebral cortex of rats. II: A quantitative assessment of glial cells in the somatosensory cortex
Authors: Miki Takanori , Yokoyama Toshifumi , Sumitani Kazunori , Wang Zhi‐Yu , Yang Weiwen , Kusaka Takashi , Matsumoto Yoshiki , Warita Katsuhiko , Lee Nam‐Seob , Fukui Yoshihiro , Takeuchi Yoshiki
Published: May 2007

The developing central nervous system is known to be highly vulnerable to X‐irradiation. Although glial cells are involved in various brain functions, knowledge on the effects of X‐irradiation on glial cells is limited. Therefore, the purpose of the present study was to evaluate the effects of prenatal X‐irradiation on glial cells. Pregnant Wistar rats were exposed to X‐irradiation at a dose of 1.0 Gy on day 15 of gestation. Their offspring were examined at 7 weeks of age. The forebrain weight of X‐irradiated rats was significantly lower than that of the age‐matched controls. Histological quantification with stereology of the somatosensory cortex (SC) revealed no significant difference in the numerical density of glial cells between the X‐irradiated and control rats. However, the glial cells in the X‐irradiated animals had significantly larger nuclear size. We had previously reported that a similar X‐irradiation paradigm resulted in no significant change in the numerical density of neurons in the SC. According to the results of the present study, there were no significant differences in the glial cell‐to‐neuron ratios between the X‐irradiated and control animals. Taken together, it is speculated that prenatal X‐irradiation has an equal effects on the numerical densities of glial cells and neurons.
ATP‐induced proliferation of developing retinal cells: regulation by factors released from postmitotic cells in culture
Authors: França Guilherme Rapozeiro , Freitas Rodrigo Cesar Carvalho , Ventura Ana Lucia Marques
Published: May 2007

ATP is an important mitogen in the developing retina and its proliferative response decreases as chick retinal cells differentiate in culture. Both non‐stimulated or ATP‐induced proliferative response was abolished if cycling cells were cocultured with cells from older embryos or cultured with conditioned medium (CM) from postmitotic cells. The effect of CM was dose‐dependent and reversible, as removal of CM from the cultures restored both basal and ATP‐induced incorporation of [3H]‐thymidine. The effect of CM was also dependent on the developmental stage of the retina used to prepare the medium. As tissues from older embryos were used, inhibition of the basal and ATP‐induced proliferative response of the cells increased. Similar inhibition of ATP‐induced increase in [3H]‐thymidine incorporation was observed using CM from purified glial cultures. Neither ARL 67156, an ecto‐ATPase inhibitor, prevented nor TGF‐β1 and TGF‐β2 mimicked the inhibitory effect of conditioned medium. Incubation of cells with CM or ATP for 24 h completely abolished the formation of [3H]‐phosphoinositides induced by ATP. These effects were blocked by the P2 receptor antagonist PPADS and were not observed with dialysed CM, suggesting that agonist‐dependent desensitization of P2 receptors occured in cultures incubated with CM. However, removal of small molecules such as nucleotides by dialysis did not affect the decline in the proliferative activity induced by CM, suggesting that desensitization is not responsible for the conditioned medium‐dependent cell cycle arrest of early developing retinal cells in culture. These results suggest that factors released from postmitotic cells induce the arrest of retinal cells in the mitotic state, a phenomenon that is concomitant with agonist‐dependent P2 receptor desensitization.
EMERGENCY NURSING
Authors: Kane Dolores
Published: May 2007

EMERGENCY NURSING, by C. L. Riehl, Peoria, Ill., Charles Bennett Co., Inc.
The Communication Systems of the Body
Authors: Miller Joan
Published: May 2007

David F. Horrobin, The Communication Systems of the Body, 1964, Basic Books, Inc., 214, $4.95.
Persuasion … how opinions and attitudes are changed
Authors: Simons Carol
Published: May 2007

Karlins, Marvin PhD, Abelson, I. Herbert PhD, Persuasion … how opinions and attitudes are changed, ed 2, 1970, Springer Publishing Co. Inc., New York, 179 pp $4.95
Occurrence, Diagnosis, and Sources of Hospital‐Associated Infections
Authors: MacClelland Doris C
Published: May 2007

Fahlberg Wilson J, Groschel Dieter, Occurrence, Diagnosis, and Sources of Hospital‐Associated Infections, 1978, Marcel Dekker, Inc, 270 Madison Ave, New York, NY 10016, 138, £18.50
Healers on Healing
Authors: Collins Marjorie A.
Published: May 2007

Healers on Healing Edited by Richard Carlson, Benjamin Shield 1989, 206 pp $11.95 paperback
Computers
Authors: Koch Frances A.
Published: May 2007

Computer Design Criteria for Systems that Support the Nursing Process By Rita D. Zielstorff, Mary L. McHugh, Jacqueline Clinton 1988, 40 pp $13.50 paperback
ECG Arrhythmia Interpretation: A Programmed Text for Health Personnel
Authors: Rusciani Rose
Published: May 2007

Braun Harold, Diettert Gerald, ECG Arrhythmia Interpretation: A Programmed Text for Health Personnel, 1979, Reston Publishing Co, Inc, 11480 Sunset Hills Rd, Reston Va 22090, 312, $14.95
Nursing: Patient Education
Authors: Kane Sister
Published: May 2007

Nursing: Patient Education. O'Connor, Andrea B, ed. American Journal of Nursing Co, 555 W 57th St, New York, NY 10019, 1979, 219 pp, $7.25 paperback.
Effect of Preadmission Brochures on Surgical Patients' Behavioral Outcomes
Authors: YOUNG ROBERTA , DE GUZMAN CAROLINA P. , MATIS MARY S. , MCCLURE KATE
Published: May 2007

This study tested the effects of preadmission teaching brochures on morning admission surgical patients' performance of specific postoperative exercises, teaching time, state anxiety, length of hospital stay, patient satisfaction, and return to functional status. The study participants were 38 women undergoing abdominal hysterectomies. Although the study results show no significant difference between those who received the preoperative teaching brochures and those who did not, the implications for further research are clearly defined. Preoperative nursing interventions that may help patients undergoing hysterectomies manage anxiety and return to function should be tested further. AORN J 60 (August 1994) 232–241.
Putting Patient‐Focused Care Into Practice
Authors: BICKLER BONNIE
Published: May 2007

Patient‐focused care relies on a framework supported by staff member empowerment and cross training, decentralization, patient care teams, and computerization. Decisions are made based on what is best for the patient rather than what is best for the staff members. How patient‐focused care is applied is influenced by the basic structure, beliefs, and values of the institution. Empowering staff members and physicians and creating specialty cluster teams were our first steps toward a patient‐focused care model. Cross training ancillary personnel to perform all tasks reduced nursing staff members' overtime and allowed for quicker response times during emergencies. Switching to a computerized documentation system enhanced departmental efficiency, removed much of the paperwork burden from nurses, and reduced costs. Patient‐focused care is measurable. We have reduced operating expenses, reduced staff turnover, increased productivity, and increased patient and physician satisfaction. AORN J 60 (August 1994) 242–245
A PRACTICAL GUIDE TO ECG INTERPRETATION
Authors: RICHARDSON KAREN
Published: May 2007

A PRACTICAL GUIDE TO ECG INTERPRETATION By Ken Grauer 1992, 350 pp $27.95 paperback
The Impact of Continuing Education on Patient Outcomes in the Elderly hip Fracture Population
Authors: Watson Donna S.
Published: May 2007

K.P. Gill, P. Ursic, Journal of Continuing Education in Nursing, 25, July/August 1994, 181, 185
Inside Gynecologic Surgery: An Illustrated Guide
Authors: Dreger Vicki
Published: May 2007

By Susan Garnett‐Nell, D. Alan Johns 1993, 173 pp $49.95 hardcover
The Nursing Process: A Scientific Approach to Nursing Care
Authors: Brannan Patricia
Published: May 2007

The Nursing Process: A Scientific Approach to Nursing Care, 3rd ed., 1983, C V Mosby Co, 11830 Westline Industrial Dr, St Louis, MO 63141, 412, $12.95 paperback.
Nursing Leadership in Action: Principles and Application to Staff Situations
Authors: Conerly Opal Lynn
Published: May 2007

Nursing Leadership in Action: Principles and Application to Staff Situations, 2nd ed. Douglas, Laura Mae, Em Olivia Bevis. St Louis: C V Mosby Co, 1974, 214 pp, $5.75 paperback.
The Time Trap: Managing Your Way Out
Authors: Kane Sister
Published: May 2007

The Time Trap: Managing Your Way Out. Mackenzie, R Alec. New York: AMA‐COM 1972, 192pp, $8.25.
Faith Healing: Finger of God? or Scientific Curiosity?
Authors: MacClelland Doris
Published: May 2007

Faith Healing: Finger of God? or Scientific Curiosity? Frazier, Claude Albee. New York and Nashville: Thomas Nelson Inc, 1973, 192 pp.
Hospital Chaplains: Who Needs Them?
Authors: Kane Sister
Published: May 2007

Hospital Chaplains: Who Needs Them? Carey, Raymond G. St Louis: The Catholic Hospital Assn, 1972, 105 pp.
Applying the Problem‐Oriented System
Authors: Minckley Barbara
Published: May 2007

Applying the Problem‐Oriented System. Walker, H Kenneth, J Willis Hurst, Mary K Woody, eds. New York: Medcom, Inc, 1974, 472 pp, $25 paperback.
Psychosocial Basis of Medical Practice
Authors: Reed Elizabeth A
Published: May 2007

Psychosocial Basis of Medical Practice. Bowden, Charles, Alvin G Burstein, et al. Baltimore: Williams and Wilkins, 1974, 229 pp, $7.95 paperback.
Neurological and Neurosurgical Nursing
Authors: Burke Kathleen
Published: May 2007

Neurological and Neurosurgical Nursing, 6th ed. Carini, Esta, Guy Owens. St Louis: C V Mosby Co, 1974, 415 pp, $11.25.
What determines the magnitude of carbon cycle‐climate feedbacks?
Authors: Matthews H. Damon , Eby Michael , Ewen Tracy , Friedlingstein Pierre , Hawkins Barbara J.
Published: May 2007

Positive feedbacks between climate change and the carbon cycle have the potential to amplify the growth of atmospheric carbon dioxide and accelerate future climate warming. However, both the magnitude of and the processes which drive future carbon cycle‐climate feedbacks remain highly uncertain. In this study, we use a coupled climate‐carbon model to investigate how the response of vegetation photosynthesis to climate change contributes to the overall strength of carbon cycle‐climate feedbacks. We find that the feedback strength is particularly sensitive to the model representation of the photosynthesis‐temperature response, with lesser sensitivity to the parameterization of soil moisture and nitrogen availability. In all simulations, large feedbacks are associated with a climatic suppression of terrestrial primary productivity and consequent reduction of terrestrial carbon uptake. This process is particularly evident in the tropics and can explain a large part of the range of carbon cycle‐climate feedbacks simulated by different coupled climate‐carbon models.
May the Shields theory be extended to cohesive and adhesive benthic sediments?
Authors: Righetti Maurizio , Lucarelli Corrado
Published: May 2007

A threshold criterion for incipient motion of cohesive‐adhesive sediments, based on moment balance and dimensional considerations, is here developed. The criterion discriminates between single particles and flocs critical conditions and induces a modification to the traditional Shields curve, commonly adopted for noncohesive particles. This modification is particularly effective for the smaller size particles but tending to vanish for the larger ones. The proposed approach is validated on the basis of experiments performed on sediment cores, sampled at different depths, from seven lakes with different trophic conditions and organic matter content. The incipient motion conditions are evaluated by means of an original procedure based on image analysis techniques, which enables the entrainment between single particles and flocs to be distinguished. The adhesion force, which is mainly due to the biological activity at the sediment water interface, is estimated following the proposed criterion and it is found to depend on the organic matter content. In particular the cores sampled in the littoral photic zone are characterized by a bell shaped dependence between adhesion coefficient and organic matter content, which is typical for indicators of biological activity of the littoral ecosystems.
Intra‐annual variations in atmospheric dust and tritium in the North Pacific region detected from an ice core from Mount Wrangell, Alaska
Authors: Yasunari Teppei J. , Shiraiwa Takayuki , Kanamori Syosaku , Fujii Yoshiyuki , Igarashi Makoto , Yamazaki Koji , Benson Carl S. , Hondoh Takeo
Published: May 2007

The North Pacific is subject to various seasonal climate phenomena and material circulations. Therefore intra‐annual ice core data are necessary for an assessment of the climate variations. To assess past variations, a 50‐m ice core was drilled at the summit of Mount Wrangell Volcano, Alaska. The dust number, tritium concentrations, and stable hydrogen isotope were analyzed. The period covered was from 1992 to 2002. We found that the concentrations of both fine dust (0.52–1.00 μm), an indicator of long‐range transport, and coarse dust (1.00–8.00 μm) increased together every spring. Moreover, their concentrations increased drastically after 2000, corresponding to the recent increase in Asian dust outbreaks in spring. Additionally, an increase in the spring of 2001 corresponded to the largest dust storm recorded in east Asia since 1979. Therefore our findings imply that Asian dust strongly polluted Mount Wrangell every spring. The stratospheric tracer, tritium, had late spring maxima almost every year, and we found this useful for ice core dating to identify late spring in the North Pacific region. We also found that a high positive annual correlation existed between the calculated tritium and fine dust fluxes from late spring to summer. We propose that an annual relationship between the stratosphere‐troposphere exchange and Asian dust storm are most closely connected in late spring because their activities are weak in summer. The Mount Wrangell ice core is important and useful for assessing the dust and tritium circulation in the distant past around the North Pacific with probable intra‐annual timescale information.
Modeling the relationship between 231Pa/230Th distribution in North Atlantic sediment and Atlantic meridional overturning circulation
Authors: Siddall Mark , Stocker Thomas F. , Henderson Gideon M. , Joos Fortunat , Frank Martin , Edwards Neil R. , Ritz Stefan P. , Müller Simon A.
Published: May 2007

Down‐core variations in North Atlantic 231Paxs/230Thxs have been interpreted as changes in the strength of the Atlantic meridional overturning circulation (AMOC). This modeling study confirms that hypothetical changes in the AMOC would indeed be recorded as changes in the distribution of sedimentary 231Paxs/230Thxs. At different sites in the North Atlantic the changes in sedimentary 231Pa/230Th that we simulate are diverse and do not reflect a simple tendency for 231Paxs/230Thxs to increase toward the production ratio (0.093) when the AMOC strength reduces but instead are moderated by the particle flux. In its collapsed or reduced state the AMOC does not remove 231Pa from the North Atlantic: Instead, 231Pa is scavenged to the North Atlantic sediment in areas of high particle flux. In this way the North Atlantic 231Paxs/230Thxs during AMOC shutdown follows the same pattern as 231Paxs/230Thxs in modern ocean basins with reduced rates of meridional overturning (i.e., Pacific or Indian oceans). We suggest that mapping the spatial distribution of 231Paxs/230Thxs across several key points in the North Atlantic is an achievable and practical qualitative indicator of the AMOC strength in the short term. Our results indicate that additional North Atlantic sites where down‐core observations of 231Paxs/230Thxs would be useful coincide with locations which were maxima in the vertical particle flux during these periods. Reliable estimates of the North Atlantic mean 231Paxs/230Thxs should remain a goal in the longer term. Our results hint at a possible “seesaw‐like” behavior in 231Pa/230Th in the South Atlantic.
Rain fade slope predicted from rain rate data
Authors: van de Kamp Max M. J. L.
Published: May 2007

A key parameter of the statistics of the rate of change of rain attenuation (“fade slope”) on satellite links is the variance of relative fade slope. This paper shows how this parameter can be derived from rain rate measurements without the use of satellite beacon measurements. Relating rain rate directly to attenuation would give unrealistic results. A theoretical model to estimate the variance of relative fade slope is derived, using the integrating effect of rain rate variations along the propagation path and using as inputs several meteorological parameters only. The theoretical values are compared to measured results from a link in the United Kingdom at 50 GHz. The agreement is good on average and also in their correlation with the type of rain and with the rain height. With the wind speed, the theoretical values increase more strongly than the measured results, which may be due to the limited spatial resolution of the meteorological data.
Comparison of observed and multimodeled trends in annual extremes of temperature and precipitation
Authors: Kiktev Dmitry , Caesar John , Alexander Lisa V. , Shiogama Hideo , Collier Mark
Published: May 2007

The performance of five global coupled climate models in simulating temporal trends in annual indices of extremes in surface temperature and precipitation during the second half of the 20th century is examined. The selected models are all represented in the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Linear trend patterns for individual model runs along with single‐ and multimodel ensemble mean trend patterns are objectively compared against corresponding observed trend fields. Some positive effects of the multimodel “super‐ensemble” approach were found when there was reasonable skill in contributing members.
On the theory of frequency-quadrupling gyroklystrons
Authors: Savilov A. V. , Nusinovich G. S.
Published: May 2007

In this paper, frequency-quadrupling three-cavity gyroklystrons with successive frequency-doubling in each stage are considered. First, it is shown that such device operating in the W band at the TE4,2-mode can deliver up to 30kW output power in the regime of stable amplification with the density of Ohmic losses acceptable for continuous-wave (cw) operation. The corresponding efficiency is in the range of 17%–20%. Then, the device is scaled to 0.5THz frequency and optimized for operation at the TE4,5-mode. At this frequency, the frequency-quadrupling gyroklystron driven by the 60kV electron beam with the beam current less than 1 A can deliver up to 1kW power with acceptable Ohmic losses. The corresponding efficiency is in the range of 1%–2%.
Effect of mobile ions on charge mobility measurements
Authors: Pokhrel Chandra , Shakya Naresh , Purtee Steven , Ellman Brett , Semyonov Alexander N. , Twieg Robert J.
Published: May 2007

We present hole time-of-flight (TOF) data on samples of the discotic liquid crystal hexapentyloxytriphenylene containing ionic impurities. By photogenerating holes at various times after reversing the potential across the cell, we have studied the effect of the ions on the measured TOF for various ionic spatial configurations. Comparing the results with simulations of coupled ionic/hole transport, we address the question of whether reliable charge transport data can be extracted for impure samples. Alternatively, we show how TOF experiments provide a useful probe of the spatiotemporal evolution of ionic charge densities under an applied potential.
Interface roughening and defect nucleation during solid phase epitaxy regrowth of doped and intrinsic Si0.83Ge0.17 alloys
Authors: D’Angelo D. , Piro A. M. , Terrasi A. , Grimaldi M. G. , Mirabella S. , Bongiorno C.
Published: May 2007

Metastable pseudomorphic Si0.83Ge0.17 with thickness of 135nm was deposited on (001) Si substrate by molecular beam epitaxy and amorphized to a depth of ∼360nm, using 3×1015cm−2 Ge ions at 270keV. Samples were regrown by solid phase epitaxy in the 500–600°C temperature range. The regrowth rate was measured in situ by time resolved reflectivity, while the structure of the epilayers was investigated by transmission electron microscopy. Three regions can be distinguished in SiGe after solid phase epitaxy, independent of the annealing temperature: (1) a 20nm defect-free layer close to the original crystal-amorphous interface, (2) a middle region with a high density of planar defects, and (3) a layer with dislocations and stacking faults extending up to the surface. The activation energy of the SiGe solid phase epitaxy is equal to the activation energy of Si except in the middle region. The amorphous-crystal interface evolution was studied by transmission electron microscopy of partially regrown samples. In order to study the effects of dopants, some samples were also implanted with B+ and Sb+ ions. At the ion projected range (125nm for both implants) the regrowth rate increases by a factor of 3 with respect to the unimplanted SiGe, but the defect-free layer again is found to be about 20nm in all cases. Moreover, the activation energy of the solid phase epitaxy regrowth process does not depend on dopant introduction, while the only observable effect of B or Sb incorporation is a smoothness of the amorphous-crystal interface during solid phase epitaxy.
Study on effect of microparticle’s size on cavitation erosion in solid-liquid system
Authors: Chen Haosheng , Liu Shihan , Wang Jiadao , Chen Darong
Published: May 2007

Five different solutions containing microparticles in different sizes were tested in a vibration cavitation erosion experiment. After the experiment, the number of erosion pits on sample surfaces, free radicals HO∙ in solutions, and mass loss all show that the cavitation erosion strength is strongly related to the particle size, and 500nm particles cause more severe cavitation erosion than other smaller or larger particles do. A model is presented to explain such result considering both nucleation and bubble-particle collision effects. Particle of a proper size will increase the number of heterogeneous nucleation and at the same time reduce the number of bubble-particle combinations, which results in more free bubbles in the solution to generate stronger cavitation erosion.
Electron screening in nanostructures
Authors: Achoyan A. , Petrosyan S. , Craig W. , Ruda H. E. , Shik A.
Published: May 2007

Distributions of electrical potential and carrier concentration, the contact capacity, and its voltage dependence are calculated for Schottky contacts to various types of nanostructures, including nanolayers and nanowires of different thickness, as well as their arrays. The results demonstrate a dramatic dependence on the nanostructure geometry. Single nanostructures and planar arrays of nanowires cannot provide effective screening of the contact potential, so that the total stored charge and the structure capacity depend on the separation between external contacts. On the contrary, for nanolayer and two-dimensional nanowire arrays, the mutual electrostatic interaction between different elements provides effective screening with the screening length equal to the interelement distance, which determines the contact capacity and its voltage dependence.
Scaling properties of subgrid-scale energy dissipation
Authors: Chumakov Sergei G.
Published: May 2007

We use direct numerical simulation of forced homogeneous isotropic turbulence with 2563 and 5123 grid points and Reynolds number based on Taylor microscale up to 250 to examine a priori the scaling properties of the subgrid-scale kinetic energy and its dissipation rate. It is found that the two quantities are strongly correlated and a power-law scaling assumption holds reasonably well. However, the scaling exponent, which was assumed to be weakly varying in previous studies, is found to change considerably with the filter characteristic width.
G
Br
6
NL
: A generalized Born method for accurately reproducing solvation energy of the nonlinear Poisson-Boltzmann equation
Authors: Tjong Harianto , Zhou Huan-Xiang
Published: May 2007

The nonlinear Poisson-Boltzmann (NLPB) equation can provide accurate modeling of electrostatic effects for nucleic acids and highly charged proteins. Generalized Born methods have been developed to mimic the linearized Poisson-Boltzmann (LPB) equation at substantially reduced cost. The computer time for solving the NLPB equation is ∼fivefold longer than for the LPB equation, thus presenting an even greater obstacle. Here we present the first generalized Born method, GBr6NL, for mimicking the NLPB equation. GBr6NL is adapted from GBr6, a generalized Born method recently developed to reproduce the solvation energy of the LPB equation [Tjong and Zhou, J. Phys. Chem. B 111, 3055 (2007)]. Salt effects predicted by GBr6NL on 55 proteins overall deviate from NLPB counterparts by 0.5kcal∕mol from ionic strengths from 10to1000mM, which is ∼10% of the average magnitudes of the salt effects. GBr6NL predictions for the salts effects on the electrostatic interaction energies of two protein:RNA complexes are very promising.
Probing thymine with laser ablation molecular beam Fourier transform microwave spectroscopy
Authors: López Juan C. , Isabel Peña M. , Eugenia Sanz M. , Alonso José L.
Published: May 2007

Laser ablation in combination with molecular beam Fourier transform microwave spectroscopy has been used to establish unambiguously the presence of the diketo form of thymine in the gas phase and to obtain its structure.
Neutral particle analyzer measurements on the SSPX spheromak
Authors: Mezonlin E. D. , Roberson S. , Raynor C. , Appartaim R. , Johnson J. A. , Afanasyev V. I. , Kozlovsky S. S. , Moller J. M. , Hill D. N. , Hooper E. B. , McLean H. S. , Wood R. D.
Published: May 2007

A neutral particle analyzer is used to measure the time-resolved energy spectrum of neutral hydrogen leaving a spheromak plasma. A gas cell filled with 10–50mTorr of helium is used to strip electrons from incoming neutral hydrogen, lowering the minimum detectable energy well below that obtained with thin foils. Effective neutral particle temperature is calculated by fitting a Maxwellian energy distribution to the measured energy spectrum above and below ∼300eV. A computational model with approximated profiles of plasma density and neutral density is used with the measured neutral hydrogen flux to estimate the ion temperature. Measurement of the power flux due to neutral hydrogen emitted at the measurement location is extended to the whole plasma surface to estimate the total charge exchange power loss from the plasma. The initial results indicate that the charge exchange power loss represents only 2% of the total input gun power during the sustainment phase of the discharge.
High-angular-resolution electron energy loss spectroscopy of hexagonal boron nitride
Authors: Arenal R. , Kociak M. , Zaluzec N. J.
Published: May 2007

High-angular-resolution electron energy loss spectroscopy (EELS) is used to study the anisotropic behavior of the boron and nitrogen K ionization edges in h-BN. This work makes significant progress toward improving the anisotropy measurements. The authors show experimentally by EELS the vanishment of the π* peak existing in these K edges in agreement with electronic structure calculations and previous soft x-ray absorption spectroscopy measurements.
Giant dielectric permittivity observed in CaCu3Ti4O12∕(Li,Ti)-doped NiO composites
Authors: Maensiri Santi , Thongbai Prasit , Yamwong Teerapon
Published: May 2007

The giant values of the dielectric permittivity as high as ε′∼105 at various frequencies (f=100kHz–1MHz) over a broad temperature range of −50–190°C have been observed in polycrystalline CaCu3Ti4O12 ceramics that are reinforced with small amount of Li0.3Ti0.02Ni0.68O nanoparticles of 39nm. This enormous dielectric permittivity is even higher than that of CaCu3Ti4O12 single crystals. The dielectric behavior of CaCu3Ti4O12 and CaCu3Ti4O12–Li0.3Ti0.02Ni0.68O composites exhibits Debye-like relaxation which can be interpreted based on Maxwell-Wagner model. The dielectric dispersion of the composites was discussed based on internal boundary layer capacitor effect.
Spatiotemporal temperature fluctuation measurements by means of a fast swept Langmuir probe array
Authors: Schubert M. , Endler M. , Thomsen H. ,   W7-AS Team
Published: May 2007

Stationary Langmuir probe measurements of ion saturation current and floating potential in a plasma cannot give direct information on density and plasma potential fluctuations in the presence of temperature fluctuations. This problem can be avoided if the probe bias voltage is continuously swept faster than the fluctuation time scale, recording the current-voltage characteristic. This article reports the development of a spatiotemporal highly resolving Langmuir probe array with 15 fast swept tips, operating in the strongly magnetized, collisionless edge plasma of the Wendelstein 7-AS stellarator [Plasma Phys. Controlled Fusion 31, 1579 (1989)]. The probe tips are aligned in the poloidal direction, the tip spacing is 2mm, and the sweeping frequency is 1.4MHz. Current and voltage data are sampled with 50MHz. The high bandwidth of the measurement is achieved by placing miniaturized differential amplifiers close to the probe tips in order to do an impedance transform. The surface-mounting technology and an additional inverse feedback module are utilized, allowing for an input voltage range of ±100V, and a common mode rejection rate of 55dB at 4MHz, which is sufficient to resolve the nonlinear probe characteristic. For the evaluation of the data, a fit model for stationary probes is employed and found adequate. Changes of the plasma parameters during one voltage sweep are taken into account by a linear interpolation of the fit parameters. Spatio-temporal fluctuation data gained by a fast swept Langmuir probe array, which can be relevant for the turbulent radial transport of particles and energy, are presented.
Nanolithography of a full-coverage octadecylphosphonic acid monolayer spin coated on a Si substrate
Authors: Nie H.-Y. , McIntyre N. S. , Lau W. M.
Published: May 2007

The authors describe a lithographic method based on a scanning probe technique to selectively remove octadecylphosphonic acid (OPA) molecules from their self-assembled monolayers (SAMs) spin coated on a Si substrate. This lithographic technique involves the use of a positively biased probe tip to scan an OPA SAM having a thickness of ∼2nm and provides an opportunity for developing a scanning probe based lithography that accommodates the need for ever-decreasing size of semiconductor devices.
Ti
O
2
based metal-semiconductor-metal ultraviolet photodetectors
Authors: Xue Hailin , Kong Xiangzi , Liu Ziran , Liu Caixia , Zhou Jingran , Chen Weiyou , Ruan Shengping , Xu Qian
Published: May 2007

Nanocrystalline TiO2 thin films were prepared by sol-gel method and were then used to fabricate metal-semiconductor-metal ultraviolet photodetectors with Au Schottky contact. It was found that dark current of the fabricated devices was only 1.9nA at 5V applied bias. High responsivity of 199A∕W was achieved when it was irradiated by the ultraviolet light (λ=260nm). The low dark current and high responsivity maybe attributed to the effect of Schottky barrier in company with neutral semiconductor owing to the wide finger gap of 20μm. The devices show a slow time response with a rise time of 6s and a decay time of 15s. The authors deduced that the slow time response was caused by defect traps which were widely distributed in nanocrysal.
European Cities in a Networked World during the Long 20th Century
Authors: Ewen Shane , Hebbert Michael
Published: May 2007

In this paper we argue that the contemporary revival of European municipalism should be examined within the rich context of the ‘long’ 20th century and the many and varied links forged between municipalities across national borders. In the first two sections we trace the emergence of the networked European municipality from the ad hoc individual connections made during the final decades of the 19th century, through the golden age of municipal internationalism during the interwar years, to the intensive cross-national cooperation pursued in the aftermath of the Second World War. We argue that the historical experience of these municipal connections was an essential prerequisite of the long-term move towards the multilevel networking experienced by European municipalities today. In the final section we focus on Eurocities, the main European municipal lobby group since the late 1980s, to show how municipalities have continued to utilise networking as their main tool within a supranational Europe, in effect to reinvent themselves within a globalised postindustrial economy.
Towards Glocal Leadership: Taking up the Challenge of New Local Governance in Europe?
Authors: Martins Lionel , Álvarez José Manuel Rodríguez
Published: May 2007

In recent years local leaders have become simultaneously intensely local, in fostering partnerships with local players, and intensely global, in going abroad to get resources, be they political, cognitive, or financial, to implement large urban projects; they have become ‘glocal’ leaders. At the same time, local stakeholders such as metropolitan or regional authorities, chambers of commerce, firms, or civil society organizations have pursued their own international objectives independently. Not all cities have therefore developed such a thing as a strategy. Nor have they all played the same hand in the international game. From this, two questions immediately arise: (i) why have some cities succeeded in carrying out an international strategy and others not? (ii) why have the successful ones chosen different paths? By focusing on local political leadership patterns in three European case studies, we argue that along with their institutional strengths the personal traits of the mayors are more than crucial to understanding why some cities have strategically played the international game and how they have played it. But this does not tell the whole story. One needs to make a detour via place-specific governance patterns, and more precisely the key local stakeholders to be convinced, persuaded, or cajoled, to properly assess the urban international strategies. With these major findings, we conclude that the ‘new international city era’ phenomenon tends to personalize local power.