bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of solid content on performance of conductive silver paste for crystalline silicon solar cells
Authors: Guo Guiquan , Gan Weiping , Liu Huan , Chen Yinglong , Xiang Feng , Luo Jian , Chen Zhibo , Li Jianqiu 
Published: March 2012

Abstract
The effect of solid content of conductive silver paste on the film thickness, microstructure of screen-printed front contact, and electrical performance of crystalline silicon solar cells was investigated. Three different solid content pastes were tested. It is found that the solid content of silver paste strongly affects the film thickness, microstructure of the thick film, and electrical performance of the cells. The paste with 84 wt.% solid content has higher viscosity and density than the ones with 82 wt.% and 83 wt.%. After sintering, the front Ag electrode thick film prepared using the paste with 84 wt.% solid content has a larger film thickness and the corresponding cell exhibits higher photoelectric conversion efficiency than the ones with 82 wt.% and 83 wt.% under the same conditions. This indicates that increasing film thickness can improve the conversion efficiency.
Microstructural and mechanical properties of dual-phase steels welded using GMAW with solid and flux-cored welding wires
Authors: Hayat Fatih , Uzun Hüseyin 
Published: March 2012

Abstract
The aim of this study is to demonstrate the transformation of grade-A steel into dual-phase steel by heat treatment, and the joint performance of dual-phase steels welded by means of the gas metal arc welding process using both solid and flux-cored welding wires. Dual-phase steels with different contents of martensite were obtained by intercritical annealing in different temperature ranges of a grade-A shipbuilding steel, followed by water quenching. The experimental results revealed that the tensile strength of the dual-phase steels joined by solid wire is higher than that of the flux-cored wire joints. The microstructure of grade-A steel consists of ferrite and pearlite, while the dual-phase steels consist of ferrite and martensite. On the other hand, while the martensitic phase is especially encountered in the weld metal of the dual-phase steels joined with the solid wire, the ferrite phase is more common in the weld metal of the flux-cored wire joints.
Combustion synthesis and characterization of bulk nanostructured Ni50Al17Fe33 alloy
Authors: Ma Jiqiang , Yang Jun , Zhang Xinghua , Bi Qinling , Fu Licai , Kang Yonghai , Liu Weimin 
Published: March 2012

Abstract
A bulk nanostructured Ni50Al17Fe33 alloy was produced by combustion synthesis associated with rapid solidification. The microstructure and mechanical properties of the as-fabricated material were investigated by means of scanning electron microscopy, X-ray diffraction, and mechanical tests. The Ni50Al17Fe33 alloy was composed of eutectic matrix and precipitated phase. The eutectic matrix consisted of 30–50 nm globular γ′-(Ni,Fe)3Al and 5–10 nm γ-Ni(Fe) boundary. The precipitate was comprised of 100–150 nm γ′-(Ni,Fe)3Al, γ-Fe, and α-Fe solid solution phases. The nanostructured Ni50Al17Fe33 alloy exhibited simultaneously high yield stress (about 900 MPa), high fracture strength (over 3860 MPa), and good ductility (over 75%) in compression.
Steady-state creep analysis of a functionally graded thick cylinder subjected to internal pressure and thermal gradient
Authors: Singh Tejeet , Gupta Vinay 
Published: March 2012

Abstract
The steady-state creep behavior in an isotropic functionally graded composite cylinder subjected to internal pressure has been analyzed in the presence of a thermal gradient. The cylinder is assumed to be made of a functionally graded composite containing silicon carbide particles in a matrix of pure aluminum. The effect of imposing a linear particle as well as a thermal gradient on the distribution of creep stresses and creep rates in the functionally graded cylinder has been investigated. The study shows that in the presence of both thermal and particle gradients, the radial stress decreases throughout the cylinder, whereas the tangential, axial, and effective stresses increase significantly near the inner radius but show a significant decrease towards the outer radius. The strain rates as well as strain-rate inhomogeneity in the composite cylinder could be reduced to a significant extent by imposing thermal and particle gradients alone or together, while keeping the same average amount of reinforcement.
Modelling of metal nano-particle condensation and growth in a reactive atmosphere
Authors: Greppi Paolo , Arato Elisabetta 
Published: March 2012

Abstract
The control of the particle size distribution of metal nano-particles produced via aerosol condensation is a technologically relevant open problem, constrained by the limits of the construction materials and by the desire to minimise carrier gas consumption.
As reactive impurities can be present in the carrier gas, we have reviewed the physical chemistry and reactivity of nano-particles and developed a quantitative, continuous model of the nucleation and particle growth processes in the presence of a reactive impurity. The model has been applied to nickel as the metal and oxygen as the impurity, but could equally well be applied to other metals and other impurities such as nitrogen, sulphur, or the halogens.
In certain conditions oxygen is only stochastically present in the nucleating nickel droplets, resulting in oxide inclusions that cannot be described by a continuous model. In other conditions the oxidation occurs simultaneously with the metal condensation and can be studied qualitatively using the developed continuous model. The model indicates that the concentration of a reactive contaminant in the gas phase could be used as an additional operating parameter to control the final particle size.
Thermodynamic properties of liquid copper–antimony–tin alloys determined from e.m.f. measurements
Authors: Jendrzejczyk-Handzlik Dominika , Gierlotka Wojciech , Fitzner Krzysztof 
Published: March 2012

Abstract
The thermodynamics properties of liquid Cu–Sn–Sb alloys were determined using solid-oxide galvanic cells with zirconia electrolyte:
(1)

Re
+
kanthal
,

Cu

x

−

Sb

y

−

Sn

(
1
−
x
−
y
)

,

SnO

2

/
/

ZrO

2

+
(

Y

2

O

3

)
/
/
NiO
,
Ni
,
Pt

in the temperature range from 998 to 1223 K.
The Gibbs free energy of formation of pure solid SnO2 from pure elements was derived. Using electromotive force values measured for the cell with x
Sn = 1.0, the following temperature dependence was obtained:

Δ

G

f
,

SnO

2

0

=
−
567903
+
200
.
33
T
(
±
1000
J
)
[
J

mol

−
1

]

Activities of tin were determined along three sections of the ternary system specified by the ratio of mole fractions x
Cu/x
Sb = 1:3, 1:1, and 3:1. Thermodynamic properties of the liquid phase were described by the Redlich–Kister–Muggianu formula. Using commercial software, phase relations in the ternary system were calculated. The results of the calculations are compared with experimental data available from literature.
Study of the structural evolution of crystalline zinc oxide films prepared by PLD
Authors: Peng Xiaoyan , Chu Jin , Muhammad Sajjad , Feng Peter 
Published: March 2012

AbstractThe structural evolution of nanocrystalline ZnO films on copper substrates synthesized via pulsed laser deposition was observed with increasing thickness controlled by deposition time. Scanning electron microscopy images indicate an increase in the average grain size. All the films are polycrystalline with the hexagonal wurtzite structure. X-ray diffraction patterns prove the orientation of the crystals to become better with an increase in film thickness. Raman measurements show three optical normal modes of crystalline ZnO indicating wurtzite structure. The line-width variation of the E2high mode reveals the structural improvement of the nanocrystalline ZnO films. The spatial correlation model was applied to analyze the structure evolution of the films. Different electron field-emission current densities are observed during the structural evolution of nanocrystalline ZnO films.
Rheology and microstructure of polymer-modified asphalt nanocomposites
Authors: Topal Ali , Sureshkumar Markanday Subramanian , Sengoz Burak , Polacco Giovanni 
Published: March 2012

AbstractAsphalt modification with polymers has utilized the advantages of nanotechnology including nanoclays as one of the components in addition to polymers. This led to the metamorphosis of polymer-modified asphalts into a new class of material called polymer-modified asphalt nanocomposites which offer the cumulative characteristic features obtained by the polymer modification of asphalt as well as the innovative properties experienced from polymer nanocomposites. Polymer-modified asphalt nanocomposites including styrene butadiene and ethylene vinyl acetate have revealed additional features which were not available in polymer-modified asphalts. The compositional complexity provides a great challenge in addressing the structure–property relations prevailing in these materials. This paper describes microstructural features as determined by Qwin Plus Software analysis and the rheological properties on compositional changes.
Numerical study of equal-channel angular pressing based on the element-free Galerkin method
Authors: Yanjin Guan , Guoqun Zhao , Ping Lu 
Published: March 2012

AbstractBased on the flow formulation for rigid–plastic/viscoplastic materials, a rigid–plastic/viscoplastic element-free Galerkin method is established to realize the simulation of massive metal-forming processes. Stiffness equations and solution formulae are derived in terms of the incomplete generalized variational principle. The transformation method is employed to exert the essential boundary condition in the local coordinate system. The arctangent frictional model is used to implement the frictional boundary conditions, and the transform matrix from the global coordinate system to local coordinate system is given. Being similar to finite-element simulations, the key techniques for metal-forming meshless analysis such as the treatment of the rigid region, dynamic adjustment of the boundary nodes, and treatment of volumetric locking are developed. The analysis software is developed. The equal-channel angular pressing process is simulated numerically using the software. The effective strains become larger and more uniform with increasing curve angle Ψ. On the other hand, the forming load increases greatly with the increase in the curve angle Ψ. The effective strains change slightly with the change of the frictional status between the die and the workpiece. However, the frictional status influences greatly the forming load.
Preparation and characterization of polyaniline/Fe3O4–polyacrylonitrile composite nanofibers
Authors: Huang Fenglin , Zhang Huidan , Shi Jinsong , Chen Fang , Cai Yibing , Wei Qufu 
Published: March 2012

AbstractPolyaniline/Fe3O4 nanocomposite was synthesized via micro-emulsion polymerization of aniline in the presence of Fe3O4 nanoparticles. The experimental results revealed that a core-shell structure composite was obtained successfully. Electrospinning of Fe3O4-polyaniline/polyacrylonitrile (Fe3O4–PANI/PAN) blended with different composition ratios were performed using N, N-Dimethylformamide as solvent. Morphology and fiber diameters were investigated by means of scanning electron microscopy. Electrospun fibers with diameters ranging from 168 to 300 nm were obtained. Scanning electron microscopy images indicated that the diameter of the composite nanofiber increases with the content of Fe3O4. It was also found that the permittivity was decreased by the addition of Fe3O4, but the permittivity was increased relevantly if the Fe3O4 mass fraction in the Fe3O4/PANI was increased. The thermal stability of the composite nanofibers is also examined in this paper.
Clinical, radiological, and genetic similarities between patients with Chiari Type I and Type 0 malformations
Authors: Markunas Christina A. , Tubbs R. Shane , Moftakhar Roham , Ashley-Koch Allison E. , Gregory Simon G. , Oakes W. Jerry , Speer Marcy C. , Iskandar Bermans J. 
Published: March 2012

Object
Although Chiari Type I (CM-I) and Type 0 (CM-0) malformations have been previously characterized clinically and radiologically, there have been no studies focusing on the possible genetic link between these disorders. The goal of this study was to identify families in whom CM-0 and CM-I co-occurred and to further assess the similarities between these disorders.

Methods
Families were ascertained through a proband with CM-I. Detailed family histories were obtained to identify first-degree relatives diagnosed with CM-0. Several criteria were used to exclude individuals with acquired forms of CM-I and/or syringomyelia. Individuals were excluded with syndromic, traumatic, infectious, or tumor-related syringomyelia, as well as CM-I due to a supratentorial mass, hydrocephalus, history of cervical or cranial surgery unrelated to CM-I, or development of symptoms following placement of a lumbar shunt. Medical records and MR images were used to characterize CM-I and CM-0 individuals clinically and radiologically.

Results
Five families were identified in which the CM-I proband had a first-degree relative with CM-0. Further assessment of affected individuals showed similar clinical and radiological features between CM-0 and CM-I individuals, although CM-I patients in general had more severe symptoms and skull base abnormalities than their CM-0 relatives. Overall, both groups showed improvement in symptoms and/or syrinx size following craniocervical decompression surgery.

Conclusions
There is accumulating evidence suggesting that CM-0 and CM-I may be caused by a common underlying developmental mechanism. The data in this study are consistent with this hypothesis, showing similar clinical and radiological features between CM-0 and CM-I individuals, as well as the occurrence of both disorders within families. Familial clustering of CM-0 and CM-I suggests that these disorders may share an underlying genetic basis, although additional epigenetic and/or environmental factors are likely to play an important role in the development of CM-0 versus CM-I.
Intraventricular lesions in tuberous sclerosis complex: a possible association with the caudate nucleus
Authors: Katz Joel S. , Milla Sarah S. , Wiggins Graham C. , Devinsky Orrin , Weiner Howard L. , Roth Jonathan 
Published: March 2012

Object
Tuberous sclerosis complex (TSC) can manifest with 3 principal intracranial pathological entities: cortical tubers, subependymal nodules (SENs), and subependymal giant cell astrocytomas (SEGAs). The authors analyzed the location and growth of intraventricular lesions in a large cohort of patients with TSC.

Methods
After institutional review board protocol approval, the authors retrospectively reviewed brain MRI scans of TSC patients for whom at least 1 electronically stored cranial MRI study was available. Collected data included location, size, and growth over time of all intraventricular lesions.

Results
The authors reviewed 560 scans in 103 patients, who harbored 496 intraventricular lesions. Of the 496 lesions, 157 lesions were located along the caudate-thalamic groove (CTG) in 88 patients. Twenty SEGAs were operated on. The remaining 339 lesions were distributed along the lateral ventricle, always in contact with the course of the caudate nucleus, and were presumed to be SENs. Twenty-two patients with more than 4 years of follow-up had 34 lesions along the CTG, of which 23 were stable in size and 11 grew. All other intraventricular lesions were stable. Seven-Tesla MRI showed the intimate association of SENs and the caudate nucleus in 1 patient.

Conclusions
Intraventricular lesions in TSC patients are located throughout the lateral ventricular wall. Their location exclusively follows the course of the caudate nucleus. Only lesions along the CTG showed the potential to grow, and these were then identified as SEGAs. The remaining lesions were SENs. Understanding why these lesions develop in relation to the caudate nucleus may offer insights into therapy.
Telemedicine-assisted treatment of patients with intracerebral hemorrhage
Authors: Angileri Filippo F. , Cardali Salvatore , Conti Alfredo , Raffa Giovanni , Tomasello Francesco 
Published: March 2012

Object
Telemedicine provides a new approach to improve stroke care in community settings, delivering acute stroke expertise to hospitals in rural areas. Given the controversies in many aspects of the treatment of intracerebral hemorrhage (ICH) and the lack of guidelines, a prompt neurosurgical second opinion may facilitate the treatment of patients with ICH. Here, the authors' 8-year experience with the use of telemedicine in the management of ICH is reported.

Methods
The medical records of patients with ICH treated through a telemedicine system in the district of Messina, Italy, between June 2003 and June 2011 were retrospectively reviewed. Neuroradiological and clinical data for patients were transmitted through a high-technology “hub-and-spoke” telemedicine network. Neurosurgical teleconsulting (at the hub) was available for 7 peripheral hospitals (spokes) serving about 700,000 people. The authors analyzed 1) the time between peripheral hospital admission and the specialized second opinion consultation, 2) primary and secondary transfers to the authors' neurosurgery department, and 3) the treatments (surgical or medical) of patients transferred to the hub.

Results
The telemedicine network was used to treat more than 2800 patients, 733 with ICH. A neurosurgical consultation was provided in 38 minutes versus 160 minutes for a consultation without telemedicine. One hundred seventy-six (24%) of 733 patients were primarily transferred to the hub. Ninety-five patients (13%) underwent surgical treatment. The remaining 81 patients (11%) underwent neurointensive care. Eight (1.4%) of 557 patients treated at the spokes needed a secondary transfer for surgical treatment because of a worsening clinical condition and/or CT findings. Considering secondary and inappropriate transfers, the interpretation of data was correct in 96.5% of cases.

Conclusions
Telemedicine allowed rapid visualization of neuroradiological and clinical data, providing neurosurgical expertise to community hospitals on demand and within minutes. It allowed the treatment of patients at peripheral hospitals and optimized resources. A small percentage of patients treated at the peripheral hospitals had secondary deterioration. Telemedicine allowed fast patient transfer when necessary and provided improved accuracy in patient care.
Neural activity generated in the neural placode and nerve roots in the neonate with spina bifida
Authors: Pugh Jeffrey A. , Aronyk Keith E. , Norton Jonathan A. 
Published: March 2012

Object
The authors conducted a study to determine the neurophysiological capacity of the neural placode in spina bifida neonates and to determine if the spinal nerve roots in these neonates had normal stimulation.

Methods
The authors present a case series of 2 neonates born with open neural tube defects who underwent neural tube closure within 24 hours of birth. Neurophysiological monitoring and electrical stimulation of the placode and nerve roots was performed before and after closure of the neural tube.

Results
Stimulation of nerve roots resulted in evoked electromyographic responses in distinct muscle groups, indicative of the myotome innervation pattern. Stimulation threshold did not change significantly after closure of the placode. Stimulation within the placode generated an alternating pattern of activity in the left and right legs.

Conclusions
Closure of the neural tube did not affect the stimulation threshold of the nerve roots, which remained easily excitable. The viability of the nerve roots suggests that they may be candidates for neural prostheses in the future. The neural placode contains basic neural elements for generating a locomotor-like pattern in response to tonic neural inputs.
Spinal arachnoid cysts in the pediatric population: report of 31 cases and a review of the literature
Authors: Bond Aaron E. , Zada Gabriel , Bowen Ira , McComb J. Gordon , Krieger Mark D. 
Published: March 2012

Object
The goal of this study was to review all cases of pediatric spinal arachnoid cysts (SACs) surgically treated at the authors' institution between 1992 and 2008 and to compare these cases to the published literature for the general population.

Methods
The charts of all pediatric patients with SACs were reviewed for demographics, medical history, presenting symptoms, imaging findings, operative procedure(s), complications, and outcomes. Following a complete literature review, the pediatric data were compared with data from the general population and unique findings associated with pediatric patients were identified.

Results
Thirty-one pediatric patients (median age 6.9 years) underwent operative intervention for SACs between 1992 and 2008 (median duration of follow-up 4.2 years). There were 17 female patients (55%) and 14 male patients (45%). Twenty-one patients (68%) presented with symptoms of radiculopathy or myelopathy. The most common presenting symptoms were pain (42%), lower-extremity weakness (39%), gait instability (32%), spasticity (19%), sensory loss (10%), and bladder dysfunction (7%). In 3 patients (10%) SACs were incidental findings. Intradural SACs were more common (18 patients, 58%) than extradural SACs (11 patients, 36%). One patient (3%) had extradural and intradural components. One patient (3%) had a purely intramedullary cyst, and 1 patient (3%) had both an intradural and intramedullary component. Of the 18 intradural SACs, 9 (50%) were located ventral to the spinal cord and 9 (50%) were dorsally situated. One dorsal intradural SAC had an intramedullary component. All extradural SACs were located dorsal to the spinal cord. Intradural SACs were primarily concentrated in the cervical and thoracic regions (67%), whereas extradural cysts were more evenly distributed between the thoracic, lumbar, and sacral regions. Of the 18 patients with intradural SACs, 13 (72%) had significant previous CNS abnormalities, compared with 3 (27%) of 11 patients with extradural SACs. There were 2 operative complications. One patient had a CSF leak treated with a lumbar drain, and the second patient had a pseudomeningocele. No patients had neurological deterioration as a result of surgical intervention. Twenty-one patients (68%) had complete remission of symptoms, 6 (19%) had improvement, 3 (10%) were stable, and 1 (3%) has worsening of symptoms with recurrence that ultimately required cystoperitoneal shunting, despite multiple failed attempts at fenestration.

Conclusions
Spinal arachnoid cysts are rare lesions in the pediatric population. Affected patients present with back pain, weakness, and/or gait instability. In children, SACs predominantly develop in the thoracic region and are more likely to occur intradurally, compared with SACs in the general population. Overall outcomes following surgical fenestration or excision of SACs are excellent, with complete remission or improvement of symptoms achieved in 87% of cases.