bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of low insolation conditions and inverter oversizing on the long‐term performance of a grid‐connected photovoltaic system
Authors: Mondol Jayanta Deb , Yohanis Yigzaw G. , Norton Brian 
Published: January 2007

AbstractThe performance of a roof mounted grid‐connected photovoltaic (PV) system in Northern Ireland was monitored over 3 years on annual, seasonal and monthly bases. The overall system performance was adversely affected by low insolation conditions; 19% of total incident insolation was absorbed at irradiance level below 200 W/m2and 67% below 600 W/m2, only 6·2% above 900 W/m2. In summer and winter, the PV and system efficiencies were 9·0 and 8·5%, and 7·8 and 7·5%, respectively and inverter efficiencies were 86·8 and 85·8%, respectively. The inverter for this particular system was oversized; 77% of the total DC energy produced when inverter's operating load was 50% of its rated capacity. The annual average monthly system performance ratio (PR) was 0·61 with seasonal variation 0·59 to 0·63. The average monthly PV, system and inverter efficiencies over the whole monitored period were 8·8, 7·6 and 86·8%, respectively. The main losses of the system were inverter DC/AC conversion loss, inverter threshold loss and low insolation loss. Copyright © 2007 John Wiley & Sons, Ltd.
Simple synthesis, photophysics, and electroluminescent properties of poly[2,7‐bis(4‐tert‐butylstyryl)fluorene‐9, 9‐diyl‐alt‐alkane‐α,ω‐diyl]
Authors: Mikroyannidis John A. , Barberis Vasilis P. , Výprachtický Drahomír , Cimrová Věra 
Published: January 2007

AbstractA simple synthetic route was used for the synthesis of a novel series of alternating copolymers based on substituted 2,7‐distyrylfluorene bridged through alkylene chains. First, 2,7‐dibromofluorene was reacted with 2 equiv of butyllithium, and this was followed by a treatment with 1 equiv of α,ω‐dibromoalkane to yield the intermediate, poly(2,7‐dibromofluorene‐9,9‐diyl‐alt‐alkane‐α,ω‐diyl). (1) Heck coupling of the latter with 1‐tert‐butyl‐4‐vinylbenzene afforded the target, poly[2,7‐bis(4‐tert‐butylstyryl)fluorene‐9,9‐diyl‐alt‐alkane‐α,ω‐diyl] (2). The two versions of 2 (2a and 2b which have hexane and decane, respectively, as alkane groups) were readily soluble in common organic solvents. Their glass‐transition temperature was relatively low (52 and 87 °C). An intense blue photoluminescence emission with maxima at about 408 and 409 nm was observed in tetrahydrofuran solutions, whereas thin films exhibited an orange emission with maxima at 569 and 588 nm. Very large redshifts of the photoluminescence maxima and Stokes shifts in thin films indicated strong aggregation in the solid state. Both polymers oxidized and reduced irreversibly. Single‐layer light‐emitting diodes with hole‐injecting indium tin oxide and electron‐injecting aluminum electrodes were fabricated. They emitted orange light with external electroluminescence efficiencies of 0.52 and 0.36% photon/electron, as determined in light‐emitting diodes made of 2a and 2b, with alkylenes of (CH2)6 and (CH2)10, respectively. An increase in the external electroluminescence efficiency up to 1.5% was reached in light‐emitting diodes made of polymer blends consisting of 2a and poly(9,9‐dihexadecylfluorene‐2,7‐diyl), which emitted blue‐white light. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 809–821, 2007.
Temperature‐modulated differential scanning calorimetry studies on the origin of double melting peaks in isothermally melt‐crystallized poly(L‐lactic acid)
Authors: Shieh Yeong‐Tarng , Liu Gin‐Lung 
Published: January 2007

AbstractIn this work, the melting behaviors of nonisothermally and isothermally melt‐crystallized poly(L‐lactic acid) (PLLA) from the melt were investigated with differential scanning calorimetry (DSC) and temperature‐modulated differential scanning calorimetry (TMDSC). The isothermal melt crystallizations of PLLA at a temperature in the range of 100–110 °C for 120 min or at 110 °C for a time in the range of 10–180 min appeared to exhibit double melting peaks in the DSC heating curves of 10 °C/min. TMDSC analysis revealed that the melting–recrystallization mechanism dominated the formation of the double melting peaks in PLLA samples following melt crystallizations at 110 °C for a shorter time (≤30 min) or at a lower temperature (100, 103, or 105 °C) for 120 min, whereas the double lamellar thickness model dominated the formation of the double melting peaks in those PLLA samples crystallized at a higher temperature (108 or 110 °C) for 120 min or at 110 °C for a longer time (≥45 min). © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 466–474, 2007
Effect of nanotube functionalization on the properties of single‐walled carbon nanotube/polyurethane composites
Authors: Buffa Fabian , Abraham Gustavo A. , Grady Brian P. , Resasco Daniel 
Published: January 2007

AbstractA commercially available aliphatic thermoplastic polyurethane formulated with a methylene bis(cyclohexyl) diisocyanate hard segment and a poly(tetramethylene oxide) soft segment and chain‐extended with 1,4‐butanediol was dissolved in dimethylformamide and mixed with dispersed single‐walled carbon nanotubes. The properties of composites made with unfunctionalized nanotubes were compared with the properties of composites made with nanotubes functionalized to contain hydroxyl groups. Functionalization almost eliminated the conductivity of the tubes according to the conductivity of the composites above the percolation threshold. In most cases, functionalized and unfunctionalized tubes yielded composites with statistically identical mechanical properties. However, composites made with functionalized tubes did have a slightly higher modulus in the rubbery plateau region at higher nanotube fractions. Small‐angle X‐ray scattering patterns indicated that the dispersion reached a plateau in the unfunctionalized composites that was consistent with the plateau in the rubbery plateau region. The room‐temperature modulus and tensile strength increase was proportionally higher than almost all increases seen previously in thermoplastic polyurethanes; however, the increase was still an order of magnitude below what has been reported for the best nanotube–polymer systems. Nanotube addition increased the hard‐segment glass transition temperature slightly, whereas the soft‐segment glass transition was so diffuse that no conclusions could be drawn. Unfunctionalized tubes suppressed the crystallization of the hard segment; whereas functionalized tubes had no effect. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 490–501, 2007
Practical mathematical model to predict the performance of insulating packages
Authors: Choi Seung‐Jin , Burgess Gary 
Published: January 2007

AbstractThermal insulation is used in a variety of applications to protect temperature‐sensitive products from thermal damage. Several factors affect the performance of insulating packages. These factors include the packaging material, the geometry of the package, the geometry of the product, and the degree of contact between the product and the package. In this study, a comprehensive model which includes all of these factors was developed to predict the performance of the insulating package. First, an equation was derived for the calculation of the thermal resistance of a multilayered wall. The wall resistance was then used in a mathematical model which included the aforementioned factors. Basic heat transfer principles covering conduction, convection and radiation were applied to the model and the package heat penetration rate was calculated. Based on this model, several factors affecting the performance of the insulating package were discussed. Examples of the use of this model for ice requirement calculations were also included. Copyright © 2007 John Wiley & Sons, Ltd.
The interobserver reliability of off‐line antral follicle counts made from stored three‐dimensional ultrasound data: a comparative study of different measurement techniques
Authors: Jayaprakasan K. , Walker K. F. , Clewes J. S. , Johnson I. R. , Raine‐Fenning N. J. 
Published: January 2007

AbstractObjectiveTo assess the interobserver reliability of antral follicle counts (AFCs) made from stored three‐dimensional (3D) ultrasound data using conventional two‐dimensional (2D) images, 3D multiplanar view and 3D‐rendered ‘inversion mode’.Methods3D transvaginal ultrasound was performed in the early follicular phase (days 2–5) of the menstrual cycle in 41 subjects aged < 40 years, undergoing investigation for subfertility. From the stored 3D ultrasound datasets, the number of antral follicles of 2–10 mm in diameter in each ovary was independently measured, using all three methods by three investigators, each with a different level of experience. The image quality of each dataset was subjectively categorized into one of three groups, based on the proportion of the ovarian contour that could be seen clearly.ResultsThere was no significant difference in the mean AFC between the observers for any of the three different techniques. The intraclass correlation coefficient (ICC) for the 2D‐equivalent mode, the 3D multiplanar mode, and the 3D‐rendered inversion mode were indicative of good interobserver reliability for each method. The interobserver reliability for the 3D‐rendered inversion mode was better with Grade 1 image quality than with Grade 3 image quality. There were no equivalent differences, however, between the three different grades of image quality with the 2D‐equivalent and 3D multiplanar modes. The time taken for AFC measurement using 3D‐rendered inversion mode was significantly longer than with the 2D equivalent and 3D multiplanar methods.Conclusions3D image displays and rendering techniques do not appear to offer any advantage over a conventional 2D display in terms of AFC measurement reliability. AFC measurement using the 3D‐rendered inversion mode has an adequate interobserver reproducibility but is dependent on image quality. Copyright © 2007 ISUOG. Published by John Wiley & Sons, Ltd.
An approximate analysis of buffered CSMA in fading channels using tagged user analysis
Authors: Rasool Shahzada Basharat , Sheikh Asrar U. H. 
Published: January 2007

AbstractIn this paper, we analyze a homogeneous finite‐users finite‐buffer (FUFB) CSMA system operating in a Rayleigh fading channel using tagged user analysis. Assuming that the system has reached a steady‐state condition in a symmetric channel, we select arbitrarily one representative user, called tagged user, and analyze its behavior in the presence of interference from other contending users. The packet service time distribution of this user is found using a state flow graph. This information is then used for the queueing analysis of the tagged user and thus different performance measures, like throughput and packet transmission delay are easily obtained. This approach decouples the channel contention from queueing behavior and greatly simplifies the problem. As shown in the paper, the approach is also transparent to channel model and spatial distribution of users. The analytical results are also verified by comparing with simulation values using a number of examples. Copyright © 2006 John Wiley & Sons, Ltd.
Struggling against selfishness and black hole attacks in MANETs
Authors: Djenouri Djamel , Badache Nadjib 
Published: January 2007

AbstractSince mobile ad hoc networks (MANETs) are infrastructureless and multi‐hop by nature, transmitting packets from any node to another usually relies on services provided by intermediate nodes. This reliance introduces a new vulnerability; one node could launch aBlack Hole DoS attackby participating in the routing protocol and including itself in routes, then simply dropping packets it receives to forward. Another motivation for dropping packets in self‐organized MANETs is resource preservation. Some solutions for detecting and isolating packet droppers have been recently proposed, but almost all of them employ the promiscuous mode monitoring approach (watchdog (WD)) which suffers from many problems, especially when employing the power control technique. In this paper we propose a novel monitoring approach that overcomes some WD's shortcomings, and improves the efficiency in detection. To overcome false detections due to nodes mobility and channel conditions we propose a Bayesian technique for the judgment, allowing node redemption before judgment. Finally, we suggest a social‐based approach for the detection approval and isolation of guilty nodes. We analyze our solution and asses its performance by simulation. The results illustrate a large improvement of our monitoring solution in detection versus the WD, and an efficiency through our judgment and isolation techniques as well. Copyright © 2007 John Wiley & Sons, Ltd.
Asymptotic solutions for large time of Hamilton–Jacobi equations in Euclidean n space
Authors: Ishii Hitoshi 
Published: January 2007

We study the large time behavior of solutions of the Cauchy problem for the Hamilton–Jacobi equation

u_{t} + H(x,Du) = 0

in

\mathbf{R}^{n} \times (0,\infty )

, where

H(x,p)

is continuous on

\mathbf{R}^{n} \times \mathbf{R}^{n}

and convex in

p

. We establish a general convergence result for viscosity solutions

u(x,t)

of the Cauchy problem as

t\rightarrow \infty

.

Résumé

Nous étudions le comportement en temps grand des solutions du problème de Cauchy pour l'équation de Hamilton–Jacobi

u_{t} + H(x,Du) = 0

dans

\mathbf{R}^{n} \times (0,\infty )

, où

H(x,p)

est continu dans

\mathbf{R}^{n} \times \mathbf{R}^{n}

et convexe en

p

. Nous établissons un résultat de convergence général pour les solutions de viscosité

u(x,t)

du problème de Cauchy quand

t\rightarrow \infty

.
The Neumann problem for the Hénon equation, trace inequalities and Steklov eigenvalues
Authors: Gazzini Marita , Serra Enrico 
Published: January 2007

We consider the Neumann problem for the Hénon equation. We obtain existence results and we analyze the symmetry properties of the ground state solutions. We prove that some symmetry and variational properties can be expressed in terms of eigenvalues of a Steklov problem. Applications are also given to extremals of certain trace inequalities.

Résumé
On considère le problème de Neumann pour l'équation de Hénon. On obtient des résultats d'existence et on analyse les propriétés de symétrie des solutions à énergie minimale. Nous démontrons que certaines propriétés variationnelles et de symétrie peuvent être exprimées à l'aide des valeurs propres d'un problème de Steklov. En outre, nous appliquons ces résultats aux fonctions réalisant la meilleure constante de certaines inégalités de trace.
Solutions of an elliptic system with a nearly critical exponent
Authors: Guerra I.A. 
Published: January 2007

Consider the problem

−\mathrm{\Delta }u_{ɛ} = v_{ɛ}^{p},\:v_{ɛ} > 0\:\text{in}\:\Omega ,

−\mathrm{\Delta }v_{ɛ} = u_{ɛ}^{q_{ɛ}},\:u_{ɛ} > 0\:\text{in}\:\Omega ,

u_{ɛ} = v_{ɛ} = 0\:\text{on}\:\partial \Omega ,

where

Ω

is a bounded convex domain in

\mathbb{R}^{N}

,

N > 2

, with smooth boundary

∂Ω

. Here

p,q_{ɛ} > 0

, and

ɛ: = \frac{N}{p + 1} + \frac{N}{q_{ɛ} + 1}−(N−2).

This problem has positive solutions for

ɛ > 0

(with

pq_{ɛ} > 1

) and no non-trivial solution for

ɛ⩽0

. We study the asymptotic behavior of
least energy
solutions as

ɛ\rightarrow 0^{ + }

. These solutions are shown to blow-up at exactly one point, and the location of this point is characterized. In addition, the shape and exact rates for blowing up are given.

Résumé
Considérons le problème

−\mathrm{\Delta }u_{ɛ} = v_{ɛ}^{p},\:v_{ɛ} > 0\:\text{en}\:\Omega ,

−\mathrm{\Delta }v_{ɛ} = u_{ɛ}^{q_{ɛ}},\:u_{ɛ} > 0\:\text{en}\:\Omega ,

u_{ɛ} = v_{ɛ} = 0\:\text{sur}\:\partial \Omega ,

où

Ω

est un domaine convexe et borné de

\mathbb{R}^{N}

,

N > 2

, avec la frontière régulière

∂Ω

. Ici

p,q_{ɛ} > 0

, et

ɛ: = \frac{N}{p + 1} + \frac{N}{q_{ɛ} + 1}−(N−2).

Ce problème a des solutions positives pour

ɛ > 0

(avec

pq_{ɛ} > 1

) et aucune solution non-triviale pour

ɛ⩽0

. Nous étudions le comportement asymptotique de solutions d'
énergie minimale
quand

ɛ\rightarrow 0^{ + }

. Ces solutions explosent en un seul point, et la position de ce point est caracterisée. De plus, le profil et les vitesses exactes d'explosion sont donnés.
Local exact Lagrangian controllability of the Burgers viscous equation
Authors: Horsin Thierry 
Published: January 2007

We study and give the definition of the exact Lagrangian controllability of the viscous Burgers equation and prove a local result. We give similar results for the heat equation in dimension 1.

Résumé
On définit et étudie la contrôlabilité exacte lagrangienne de l'équation de Burgers dissipative, et prouve un résultat local. On donne des résultats similaires en dimension 1 pour l'équation de la chaleur.
Blow-up of a non-local semilinear parabolic equation with Neumann boundary conditions
Authors: Kiwan R. , Jazar M. 
Published: January 2007

In this paper we give a positive answer to the conjecture proposed in [A. El Soufi, M. Jazar, R. Monneau, A Gamma-convergence argument for the blow-up of a non-local semilinear parabolic equation with Neumann boundary conditions, Ann. Inst. H. Poincaré Anal. Non Linéaire 24 (1) (2007) 17–39] by El Soufi et al. concerning the finite time blow-up for solutions of the problem (1), (2) below. More precisely, we give a direct proof of [A. El Soufi, M. Jazar, R. Monneau, A Gamma-convergence argument for the blow-up of a non-local semilinear parabolic equation with Neumann boundary conditions, Ann. Inst. H. Poincaré Anal. Non Linéaire 24 (1) (2007) 17–39, Theorem 1.1] and the conjecture given for the case

p > 2

.

Résumé

Dans cet article on donne une réponse positive à la conjecture proposeé dans [A. El Soufi, M. Jazar, R. Monneau, A Gamma-convergence argument for the blow-up of a non-local semilinear parabolic equation with Neumann boundary conditions, Ann. Inst. H. Poincaré Anal. Non Linéaire 24 (1) (2007) 17–39] par El Soufi et al. concernant l'explosion en temps fini des solutions du problème (1), (2) ci-dessous. Plus précisément, on donne une preuve directe du [A. El Soufi, M. Jazar, R. Monneau, A Gamma-convergence argument for the blow-up of a non-local semilinear parabolic equation with Neumann boundary conditions, Ann. Inst. H. Poincaré Anal. Non Linéaire 24 (1) (2007) 17–39, Theorem 1.1] ainsi que la conjecture énoncée pour le cas

p > 2

.
Bilateral versus unilateral sudden sensorineural hearing loss
Authors: Oh Jeong‐Hoon , Park Keehyun , Lee Seung Joo , Shin You Ree , Choung Yun‐Hoon 
Published: January 2007

OBJECTIVESTo analyze the clinical characteristics and treatment results between bilateral (bi‐) and unilateral (uni‐) sudden sensorineural hearing loss (SSNHL).STUDY DESIGN AND SETTINGA retrospective study.METHODSThree hundred twenty‐four patients with SSNHL were classified into two groups; simultaneous bi‐SSNHL (n = 16) and uni‐SSNHL (n = 308). We compared clinical characteristics, medical history, hearing level, and treatment results between the 2 groups.RESULTSThe incidence of bi‐SSNHL was 4.9 percent of overall patients with SSNHL. Bi‐SSNHL occurs more commonly in patients of older age, with preexisting diabetes mellitus, and lipid panel abnormalities compared with uni‐SSNHL. Ten patients (62.5%) in the bi‐SSNHL group showed hearing recovery in 1 or both ears compared with 56.5 percent of patients with uni‐SSNHL. Only 12 (37.5%) of all 32 ears recovered in bi‐SSNHL, which was significantly lower than in uni‐SSNHL.CONCLUSIONBi‐SSNHL has a very low incidence and lower recovery rate than uni‐SSNHL. Recognition of similarities and differences between bilateral and unilateral SSNHL can help in counseling and managing the patients.© 2007 American Academy of Otolaryngology–Head and Neck Surgery Foundation. All rights reserved.
Audiovestibular disturbance in patients with systemic lupus erythematosus
Authors: Karatas Erkan , Onat Ahmet Mesut , Durucu Cengiz , Baglam Tekin , Kanlikama Muzaffer , Altunoren Orcun , Buyukhatipoglu Hakan 
Published: January 2007

OBJECTIVEThe aim of this study was to evaluate the audiovestibular disturbance in patients with systemic lupus erythematosus (SLE).STUDY DESIGN AND SETTINGTwenty‐eight patients with SLE and 28 healthy control subjects were included. Pure‐tone audiometry, impedance audiometry, and electronystagmography (ENG) were used for baseline evaluation. Laboratory tests were carried out. Cranial and brain stem magnetic resonance imagings (MRI) were undertaken.RESULTSNineteen (67%) patients reported audiovestibular symptoms. Sensorineural hearing loss was found in 6 (21%) patients. Abnormal results on ENG were significantly higher (50%) (P < 0.01). Abnormal laboratory data were available from 26 patients (P < 0.05). MRI did not show any pathosis.CONCLUSIONThe audiovestibular disturbances in SLE are more prevalent than previously recognized. Although no cause and effect relationship can be established by this type of study, it appears that a relationship exists.SIGNIFICANCEAudiologic research should be directed toward routine, pure tone audiometry, and ENG assessment for patients with SLE to enable crucial treatment.© 2007 American Academy of Otolaryngology‐Head and Neck Surgery Foundation. All rights reserved.
Deterioration in quality of life and depressive symptoms during radiation therapy for head and neck cancer
Authors: Kelly Charles , Paleri Vinidh , Downs Carole , Shah Raina 
Published: January 2007

OBJECTIVEThe aim of this study was to assess the quality of life and psychologic profile during radiation therapy for head and neck cancer.STUDY DESIGN AND SETTINGThe University of Washington QoL instrument and the Hospital Anxiety and Depression Scale were administered to 202 patients at two or three time points during radiation therapy.RESULTSA total of 118 (54.6%) patients completed the questionnaires at the beginning and at the end of the study. A mid‐treatment dataset was also available for 67 (31.0%) patients. There was a statistically significant deterioration in composite QoL scores (P < 0.000) and a statistically significant increase in depression (P < 0.000). There was no difference in anxiety levels (P = 0.276).CONCLUSIONPatients undergoing radiation are increasingly depressed as treatment progresses, with worsening QoL during the treatment.SIGNIFICANCEThis study underlines the need for good psychologic support during radiation therapy in head and neck cancer.© 2007 American Academy of Otolaryngology‐Head and Neck Surgery Foundation. All rights reserved.
Hearing threshold shift measured by otoacoustic emissions after shooting noise exposure in soldiers using hearing protectors
Authors: Olszewski Jurek , Miłoński Jarosław , Olszewski Sławomir , Majak Joanna 
Published: January 2007

OBJECTIVEThe aim of the study was to assess the influence of short‐term impulse noise to temporary threshold shift in soldiers using hearing protectors.STUDY DESIGN AND SETTINGThe study included 80 subjects with correct tympanic membrane and thresholds measured by pure‐tone audiometry less than 20 dB. There were two groups: 40 soldiers protected during shooting and 40 young males who didn't shoot. TEOAE were performed by ILO 292 Echoport Otodynamics device 3 to 5 minutes before shooting and 2 minutes and 1, 2, and 3 hours after shooting.RESULTSShort‐term exposure to impulse noise generated by five gunshots from the rifle kbk AKMS hasn't induced temporary threshold shift of hearing for chosen frequencies in soldiers using hearing protectors. Spectral analysis for chosen frequencies revealed that measurement reproducibility, stimuli level, and probe stability appeared to be comparable and repeatable.CONCLUSIONOur results show that the use of hearing protectors safeguarded against impulse noise.SIGNIFICANCEThe use of earmuffs is strongly recommended because they seem to sufficiently attenuate shooting noise.© 2007 American Academy of Otolaryngology‐Head and Neck Surgery Foundation. All rights reserved.