8,215 research outputs found
Electrospun nanofibers of manganese oxides with mixed phase for supercapacitor
Energy EngineeringElectrospinning technique produces continuous fibers of various structures and composition with diameters ranging from a few micrometers to nanometers. Particularly, the three-dimensional (3D) non-woven fiber matrix contains a large porous network structure which is highly suitable for electrode applications that can facilitate the access of electrolytes into the active species. For that, we have fabricated the inorganic manganese oxide (MnOx) nanofibers (NFs) of varying composition by electrospinning technique for supercapacitor applications. MnOx is promising for pseudocapacitor due to their fine specific capacitance, low cost, and environmental benignity. In this study, we prepared the electrospun NFs of Mn(OAc)2/poly(vinyl pyrrolidone) (PVP) composite by using electrospinning technique. The as-prepared inorganic NFs were annealed at different temperatures to remove the polymer matrix and resulted in the MnOx NFs of varying composition. Interestingly, we found that the capacitance of MnOx NFs annealed at 500 oC is highest among all samples with contained a mixed phase of Mn2O3 and Mn3O4.ope
Static and dynamic synthesis of partitioned substructures
Substructuring is to subdivide an overall structure into two or more substructures to reduce the model-order of the huge structural system. The problem to synthesize the substructures is established by a mathematical system consisting of equilibrium equations and prescribed compatibility conditions. Considering that the compatibility conditions are constraints, this study derives the analytical methods for describing the responses of constrained static and dynamic systems and provides a structural synthesis method based on the Guyan condensation method and the derived equations. The analysis process is carried out by partitioning into two regions of interior and boundary regions, and giving the compatibility conditions. And the dynamic analysis reduces model-order based on the constraint conditions between modal coordinates by the first several mode shape matrix. The validity of the proposed method is illustrated through the structural synthesis of stable and unstable substructures, and the structural reanalysis to evaluate the structural response for changes in the design without solving the complete set of modified simultaneous equation
FRF based substructuring and decoupling of substructures
This study considers FRF (frequency response function) based substructuring and decoupling of substructures for the dynamic analysis of complicated huge structures utilizing compatibility conditions between adjacent substructures. This work includes: 1) the derivation of updated FRF matrix for dynamic system subjected to frequency or time dependent constraints in the frequency-domain, 2) the synthesis and decoupling of subsystems based on the dual domain approach using compatibility conditions between adjacent subsystems, 3) the evaluation of the validity of the proposed methods through numerical applications. It is expected that the proposed methods will be utilized as the basic formulation in investigating the dynamic characteristics of partitioned or synthesized system
Providing culturally appropriate environments in nursing homes for frail ethnic minority elders in the U.S. : three case studies of Korean-American nursing homes
Title from PDF of title page (University of Missouri--Columbia, viewed on August 23, 2010).Dissertation advisor: Dr. Benyamin Schwarz.Vita.Apprendices in English and Korean.Ph. D. University of Missouri--Columbia 2010.Korean American elders are one of the fastest growing Asian ethnic subgroups in the United States, adding to the growing cultural and linguistic diversity of the older population. Yet no published study was found on Korean American nursing home environments and the needs, preferences, and levels of satisfaction of Korean American residents in ethnic nursing homes in the United States. The main purpose of this study is to describe the physical, social, and organizational environments of nursing homes in order to increase their cultural appropriateness and thus improve the quality of life for frail Korean American elders. There were multiple data collection methods, but three case studies of Korean American nursing homes on the East Coast included interviews with 26 Korean American elders, 6 relatives, and 5 staff members. All facilities emphasized organizational environments (e.g., special services and activity programs) over physical and social environments. All had some Korean staff and provided Korean foods at meals, church services in Korean, cultural activities, and Korean cable-TV channels. Through qualitative data analysis, 2 main themes and 9 subthemes emerged. Korean American elders were less likely to be assimilated into American culture and wanted to maintain the Korean way of life in a U.S. nursing home. Although residents were satisfied with the facilities overall, they expressed two major dissatisfactions: no freedom and nobody to talk with them. The findings of this study will contribute to the knowledge of nursing home care providers and designers of nursing homes where many Korean American residents live.Includes bibliographical reference
Damage detection of beam structure using response data measured by strain gages
The health state of a structural beam as a flexural member can be evaluated by the curvature or flexural strain. Measured strain data provide more accurate flexural characteristics than the curvature approximation by the central difference method from the displacement mode shape and DFRFs (displacement frequency response functions). The strain sensor may be sensitive to local damage when analyzing the flexural response. This work presents a method to detect damage utilizing only the measured strain data collected from a damage-expected beam structure without intact baseline data. The static method from the measurement strain data and the dynamic method from measured SFRFs (strain frequency response functions) are introduced. It can be observed that damage exists in the region, which represents an abrupt change in the strain response. The validity of the method is illustrated by numerical and experimental applications
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The influence of social power on weight perception.
Lee, E. H., & Schnall, S. (in press). The influence of social power on weight perception. Journal of Experimental Psychology: General
Understanding User Perception and Intention to Use Smart Homes for Energy Efficiency: A Survey
The positive impact of Smart Homes on energy efficiency is heavily dependent
on how consumers use the system after adoption. While the technical aspects of
Smart Home systems and their potential to reduce energy usage is a focus of
various studies, there is a limited consideration of behavioral psychology
while designing systems for energy management. To investigate users' perception
and intention to use Smart Homes to support energy efficiency, we design a
research model by combining a theory of planned behavior and the norm
activation model. We design a questionnaire and conduct a survey targeting
current smart home users (over 350 responses). To analyze the survey results,
we extend the partial least squares structural equation modeling (PLS-SEM) by a
random forest algorithm. The findings suggest that personal norms have the
strongest influence on behavioral intention to use Smart Homes for energy
efficiency, followed by the ascription of responsibility. Furthermore, the
results support the effects of attitudes, subjective norms, awareness of
consequences, as well as the moderating effect of past behavior on the
relationship between personal norms and behavioral intentions
Update of FRF matrix and physical parameters of finite element model
Numerically simulated results by finite element model of a dynamic system do rarely coincide with the actual responses of the structure due to the modeling, manufacturing errors or other causes. The parameters of the finite element model should be corrected for subsequent proper analysis. Minimizing a cost function by the difference between the analytical and actual dynamic stiffness matrices along with constrained conditions of measured FRFs (Frequency Response Functions), this work provides the mathematical form on the updated FRF. The updated parameter matrices of the structure are derived from the FRF variation within the prescribed frequency range. It is shown that the exactness of the proposed method depends on the number of the measured data. The validity of the proposed method is illustrated in updating the parameter matrices of a planar truss structure
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