3,893 research outputs found
Fabrication of Microfiber Patterns with Ivy Shoot-Like Geometries Using Improved Electrospinning
Fibers and fibrous structures are used extensively in various fields due to their many advantages. Microfibers, as well as nanofibers, are considered to be some of the most valuable forms of advanced materials. Accordingly, various methods for fabricating microfibers have been developed. Electrospinning is a useful fabrication method for continuous polymeric nano- and microfibers with attractive merits. However, this technique has limitations in its ability to control the geometry of fibrous structures. Herein, advanced electrospinning with direct-writing functionality was used to fabricate microfiber patterns with ivy shoot-like geometries after experimentally investigating the effects of the process conditions on the fiber formation. The surface properties of the fibers were also modified by introducing nanoscale pores through the use of higher levels of humidity during the fabrication process.ope
Accelerating Aquatic Soft Robots with Elastic Instability Effects
Sinusoidal undulation has long been considered the most successful swimming
pattern for fish and bionic aquatic robots [1]. However, a swimming pattern
generated by the hair clip mechanism (HCM, part iii, Figure 1A) [2]~[5] may
challenge this knowledge. HCM is an in-plane prestressed bi-stable mechanism
that stores elastic energy and releases the stored energy quickly via its
snap-through buckling. When used for fish robots, the HCM functions as the fish
body and creates unique swimming patterns that we term HCM undulation. With the
same energy consumption [3], HCM fish outperforms the traditionally designed
soft fish with a two-fold increase in cruising speed. We reproduce this
phenomenon in a single-link simulation with Aquarium [6]. HCM undulation
generates an average propulsion of 16.7 N/m, 2-3 times larger than the
reference undulation (6.78 N/m), sine pattern (5.34 N/m/s), and cambering sine
pattern (6.36 N/m), and achieves an efficiency close to the sine pattern. These
results can aid in developing fish robots and faster swimming patterns
Validation of the South Korean Version of the Beliefs about Emotions Scale
Background
Beliefs about the unacceptability of experiencing or expressing negative emotions can contribute to diverse psychological symptoms and associated with poor treatment outcomes and low treatment attempts. The Beliefs about Emotions Scale (BES) was developed to assess such beliefs based on the cognitive-behavioral models; however, no study has reported on the psychometric properties of the BES in Korea. The present study aimed to cross-culturally adapt and validate the BES for the Korean population (BES-K). Methods
The BES-K was administered to 592 Korean adults (323 men and 269 women) aged 20–59 years. Exploratory and confirmatory factor analysis were used to assess the factor model of the scale. Pearson correlation coefficients were used to evaluate the relationships between the BES-K and other psychological measures. Results
The result showed a two-factor model of the BES-K, with Factor 1 relating to Interpersonal and Factor 2 representing Intrapersonal aspects. The scale had significant yet moderately low correlations with measures of depression, anxiety, and difficulties in emotion regulation. Conclusion
The BES-K is a useful instrument in evaluating the beliefs about emotions in the Korean population
Aerobic Copper-Promoted Oxidative Dehydrosulfurative Carbon-Oxygen Cross-Coupling of 3,4-Dihydropyrimidine-1: H -2-Thiones With Alcohols
An aerobic Cu-promoted oxidative dehydrosulfurative carbon-oxygen cross-coupling of 3,4-dihydropyrimidin-1H-2-thiones (DHPMs) with both aliphatic and aromatic alcohols is described. Together with the ready availability of DHPMs and both alcohols, the method furnishes facile access to biologically valuable 2-alkoxypyrimidines with rapid diversification
DECAY FACTOR WITH EXPERIMENTAL VARIABLES IN TWO CIRCULATING FLUIDIZED BED (CFB) RISERS
The effects of the riser inlet velocity, solid mass flux and particle size on the axial solid holdup profile and decay factor were investigated using two circulating fluidized beds (CFBs) with FCC (Geldart A) particles as the bed materials. Based on the experimental results from the two-CFBs, the axial solid holdup in the two CFBs were compared with the correlations of previous studies. Also, an empirical correlation was proposed for decay factor that exhibited a good agreement with experimental data
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