3,406 research outputs found
Bias dependent specic contact resistance of phase change material to metal contacts
Knowledge of contact resistance of phase change materials (PCM) to metal electrodes is important for scaling, device modeling and optimization of phase change random access memory (PCRAM) cells. In this article, we report the systematic determination of the speci_c contact resistance (_c) with voltage bias for doped Sb2Te to TiW metal electrodes. These data are reported for both the amorphous and the crystalline state of the PCM
Impact of sidewalls on electrical characterization
In this article the impact of sidewalls, formed during reactive ion etching, on the electrical behavior of thin film structures is presented. The presence of sidewalls was experimentally characterized by sheet resistance measurements on Van der Pauw structures. The effect of these sidewalls on the extraction of specific contact resistance from Cross Bridge Kelvin Resistance (CBKR) structures is discussed
Special Education in the Twenty First Century : Challenges and Opportunities or a New Graveyard?
1999 Brown, reprinted 2016Peer reviewedPublisher PD
A note on accelerating cosmologies from compactifications and S-branes
We give a simple interpretation of the recent solutions for cosmologies with
a transient accelerating phase obtained from compactification in hyperbolic
manifolds, or from S-brane solutions of string/M-theory. In the
four-dimensional picture, these solutions correspond to bouncing the radion
field off its exponential potential. Acceleration occurs at the turning point,
when the radion stops and the potential energy momentarily dominates. The
virtues and limitations of these approaches become quite transparent in this
interpretation.Comment: 9 pages, 1 figure. References adde
Electrical characterization of Thin-Film structures with redeposited sidewall
Accurate electrical characterization of test structures and devices requires identification and correction for parasitic current paths in the measurement network. The sidewalls formed during reactive ion etching of thin-film phase-change material layers in argon plasma can result in parasitic current paths in the structures. In this paper, thin-film structures with redeposited sidewalls are realized, and they are experimentally characterized by electrical resistance measurements on van der Pauw test structures. The impact of conducting sidewalls on contact resistance measurements and data extraction from cross-bridge Kelvin resistor structures is discussed. The error introduced in the electrical resistance measurements from these test structures is analytically modeled. The impact on the electrical performance of devices due to the formation of sidewalls is also discussed
Perceptions of Agribusiness Leaders toward Agricultural Education in Nebraska
The purpose of the study was to determine the perceptions of agribusiness leaders with regard to Agricultural Education in the State of Nebraska. More specifically, the objectives were to: 1. Determine perceptions of the skills, attitudes and knowledge that should be taught in Nebraska\u27s elementary and secondary schools to prepare students for their future in agriculture Determine perceptions of funding levels for agricultural education in Nebraska. Determine perceptions of the need for a name change for vocational agriculture in Nebraska\u27s secondary schools. Determine perceptions of where various agricultural knowledge, skills, and attitudes should be taught at the elementary, junior high, and high school levels. Determine perceptions with respect to the effectiveness of leadership from the teacher education program in agriculture at the University of Nebraska-Lincoln and the Agriculture Division of The Nebraska Department of Education
The Mechanical Behavior of a 25Cr Super Duplex Stainless Steel at Elevated Temperature
Peer reviewedPostprin
Prospective, single UK centre, comparative study of the predictive values of contrast-enhanced ultrasound compared to time-resolved CT angiography in the detection and characterisation of endoleaks in high-risk patients undergoing endovascular aneurysm repair surveillance: a protocol.
INTRODUCTION: Diagnosis of endoleaks is imperative to prevent failure of endovascular aneurysm repairs (EVARs). The gold standard for diagnosis of endoleaks is catheter-directed subtraction angiography, which is not a practicable choice for surveillance. CT angiography (CTA) is the historical surveillance modality of choice. Concerns over cost, potential nephrotoxicity of contrast agents and repeated radiation exposure led to colour duplex ultrasound scan (CDUS) becoming an established alternative. CDUS has a lower sensitivity and specificity for endoleaks detection compared to CTA. Contrast-enhanced ultrasound scan (CEUS) represents an improvement of ultrasound imaging but comparisons against CTA report widely varying results, likely due to technical factors of CEUS and limitations of single-phase CTA.The development of time-resolved CTA (tCTA) offers timing information that much more closely mirrors the dynamic information available from CEUS. Theoretically, these two imaging modalities have the best potential for diagnostic accuracy. The aim of this study will be to compare CEUS to tCTA and investigate the utility of other measurements available from tCTA. METHODS AND ANALYSIS: This is a prospective, single UK centre, comparative study of paired binary diagnostic imaging modalities. Patients identified in routine post-EVAR surveillance as at risk of having a graft-related endoleak will undergo a CEUS and tCTA on the same day. This will allow the first comparison of CEUS to a semidynamic form of CTA. CEUS sensitivity and specificity to endoleak detection will be calculated. ETHICS AND DISSEMINATION: The study has achieved ethical approval. We hope the results will define the diagnostic accuracy of CEUS in comparison to a semidynamic form of CTA, representing a methodological improvement from previous studies. Results will be submitted for presentation at national and international vascular surgeryandradiology meetings. The full results are planned to be published in a medical journal. TRIAL REGISTRATION NUMBER: NCT02688751
Growth, structural and plasma illumination properties of nanocrystalline diamond-decoratedgraphene nanoflakes
Decorating graphene nanoflakes with nanocrystalline diamond gives superior functioning for microplasma devices with long lifetime stability plasma illumination performances.</p
Translation, Validity, and Reliability of the Dutch Anterior Cruciate Ligament–Quality of Life Questionnaire
Background: The Anterior Cruciate Ligament–Quality of Life (ACL-QoL) questionnaire is a valid and reliable injury-specific instrument to assess the impact of an ACL rupture on the daily life of a patient. Purpose: To translate the ACL-QoL into Dutch (ACL-QoL-NL) and to study its psychometric properties in patients with an ACL rupture. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: The original ACL-QoL questionnaire was translated from English to Dutch according to international guidelines. The study population consisted of 122 patients with a confirmed ACL rupture who completed the ACL-QoL-NL as well as 4 questionnaires: the International Knee Documentation Committee subjective score, Knee injury and Osteoarthritis Outcome Score, 36-item Short Form Health Survey, and Lysholm Knee Score. We determined the internal consistency, construct validity, and prevalence of floor and ceiling effects of the ACL-QoL-NL total score as well as its 5 subscales. To determine test-retest reliability, we analyzed the data of 68 patients who had a stable knee condition and who completed the ACL-QoL-NL a second time after a 2-week interval. Results: The confirmatory factor analysis showed that the original structure of the ACL-QoL-NL was confirmed, except for 4 of 31 items. Internal consistency of the total scale and all 5 subscales was good. More than 75% of the predefined hypotheses on the correlations between the ACL-QoL-NL and the 4 questionnaires were met, indicating good construct validity. No significant floor or ceiling effects were observed. Test-retest reliability was good, and no systematic bias between test and retest was found. Standard error of measurement for the total score was 4.8 points out of 100, and the smallest detectable changes at the group and individual levels were 1.6 and 13.2 points, respectively. Conclusion: The ACL-QoL-NL questionnaire was successfully translated from English to Dutch and demonstrated good internal consistency, validity, and reliability, with no presence of floor or ceiling effects
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