IBMM of OH adsorbates and interphases on Si-based materials
N. Herbots , Qian Xing, M. Hart, J.D. Bradley, D.A. Sell, R.J. Culbertson, Barry J. Wilkens
Department of Physics, Arizona State University, Tempe, AZ 85287-1504, USA
FINAL REFERENCE:
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms
Volume 272, 1 February 2012, Pages 330-333
Proceedings of the 17th International Conference on Ion Beam Modification of Materials (IBMM 2010)
Please cite this article as
N. Herbots. Q. Xing et al., IBMM of OH adsorbates and interphases on Si-based materials, Nucl. Instr. and Meth. , Vol 272, pp 330-333 (2012),
doi:10.1016/j.nimb.2011.01.094
Using ion beam modification, films composed of synthesized
‘‘interphases’’ of ordered silica on OH-passivated (1... more
Using ion beam modification, films composed of synthesized
‘‘interphases’’ of ordered silica on OH-passivated (1 X 1) Si(100) underwent surface electro-chemical changes quantified by surface free energy via Sessile drop method and contact angle analysis using Young’s equation and Van Oss theory. IBMM caused the surface free energies initially ranging from 26.0 mJ/m2 to 57.3 mJ/m2 to converge to 43.1–45.4 mJ/m2 for various passivated and as-received wafer samples alike. Although TMAFM also identified topographic changes, these changes did not correlate to the change of surface free energies. Ion beam modification of the ordered silica film on Si(100) surface is analyzed using 3.045 MeV 16O(a, a)16O nuclear resonance scattering (NRS) in conjunction with channeling in (1 1 1) direction, which demonstrated the convergence of the partially ordered oxygen to amorphous at about 55 microCoulombs/mm2 He++ flux. Additionally, Si surface peak channeling in (1 0 0) and (1 1 1) directions also experienced an uptrend in areal density as incident ion flux increased, while the rotating random Si signal height remains stable, showing a disruption in the surface order during IBMM.
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Seen by: and 3 moreImplementing, Embedding, And Integrating Practices:
by Carl May
Carl May & Tracy Finch. Sociology 2009; 43(3): 535-554
ABSTRACT
Understanding the processes by which practices become routinely embedded in everyday... more
ABSTRACT
Understanding the processes by which practices become routinely embedded in everyday life is a longstanding concern of sociology and the other social sciences. It has important applied relevance in understanding and evaluating the implementation of material practices across a range of settings. This paper sets out a theory of normalization processes that proposes a working model of implementation, embedding and integration in conditions marked by complexity and emergence. The theory focuses on the work of embedding and of sustaining practices within interaction chains, and helps in understanding why some processes seem to lead to a practice becoming normalized while others do not.
My agreement with Sage is that this paper is available on an open access basis. It can be found at: http://soc.sagepub.com/cgi/content/abstract/43/3/535
Let me know if you can't access it and I'll send you a copy.
A review on biodegradable polymeric materials for bone tissue
Journal of Materials Science
Volume 44, Number 21, 5713-5724, DOI: 10.1007/s10853-009-3770-7
Biodegradable polymer scaffolds have played a
significant role in wide range of tissue engineering application... more
Biodegradable polymer scaffolds have played a
significant role in wide range of tissue engineering application
such as bone scaffolds since the last decade. The aim
of this article is to provide the comprehensive overview of
biocompatible and biodegradable polymer materials and
composite materials with their advantages and drawbacks
in the application of biomaterial scaffolds, furthermore the
properties and degradation criteria of the biomaterials are
discussed in this review.
The effects of prosthetic ankle dorsiflexion and energy return on below-knee amputee leg loading.
Ventura, J.D., Klute, G.K. and Neptune, R.R.
Background: Prosthetic devices are intended to return lower limb amputees to their pre-amputation functional status.... more
Background: Prosthetic devices are intended to return lower limb amputees to their pre-amputation functional status. However, prosthetic devices designed for unilateral below-knee amputees have yet to completely restore the biomechanical functions normally provided by the ankle muscles leading to gait asymmetries and increased reliance on their intact leg. In an effort to improve amputee gait, energy storage and return feet have been developed that store mechanical energy in elastic structures in early to mid-stance and return it in late stance. However, little is known regarding how ankle compliance and the level of energy return influences walking mechanics. The purpose of this study was to identify the influence of prosthetic ankle dorsiflexion and energy storage and return on leg loading during steady-state walking.
Methods: Compliant ankles with different stiffness levels were attached to a Seattle Lightfoot2 in different orientations (forward- and reverse-facing).
Findings: The ankles decreased residual leg vertical ground reaction forces in late stance, increased residual leg propulsive ground reaction force impulses, and increased residual leg knee joint extensor moments. The reverse-facing ankles increased residual leg vertical ground reaction forces in early stance, and the compliant forward-facing ankle increased residual leg braking impulses. In contrast to previous studies, increased energy storage and return from compliant ankles did not decrease hip joint powers or the intact leg vertical ground reaction forces.
Interpretation: These results provide insight into the relationships between ankle dorsiflexion, energy storage and return, and leg loading, which may lead to more effective prosthetic devices to improve amputee gait.
The effect of prosthetic ankle energy storage and return properties on muscle activity in below-knee amputee walking
Ventura, J.D., Klute, G.K. and Neptune, R.R.
In an effort to improve amputee gait, energy storage and return (ESAR) prosthetic feet have been developed to provide... more
In an effort to improve amputee gait, energy storage and return (ESAR) prosthetic feet have been developed to provide enhanced function by storing and returning mechanical energy through elastic structures. However, the effect of ESAR feet on muscle activity in amputee walking is not well understood. Previous studies have analyzed commercial prosthetic feet with a wide range of material properties and geometries, making it difficult to associate specific ESAR properties with changes in muscle activity. In contrast, prosthetic ankles offer a systematic way to manipulate ESAR properties while keeping the prosthetic heel and keel geometry intact. In the present study, ESAR ankles were added to a Seattle Lightfoot to carefully control the energy storage and return by altering the ankle stiffness and orientation in order to identify its effect on lower extremity muscle activity during below-knee amputee walking. A total of five foot conditions were analyzed: solid ankle (SA), stiff forward-facing ankle (FA), compliant FA, stiff reverse-facing ankle (RA), and compliant RA. The ESAR ankles decreased the activity of muscles that contribute to body forward propulsion and increased the activity of muscles that provide body support. The compliant ankles generally caused a greater change in muscle activity than the stiff ankles, but without a corresponding increase in energy return. Ankle
orientation also had an effect, with RA generally causing a lower change in muscle activity than FA. These results highlight the influence of ESAR stiffness on muscle activity and the importance of prescribing appropriate prosthetic foot stiffness to improve rehabilitation outcomes.

