scholarly journals The relationship between resonant frequency band and cell size in left-handed materials

2009 ◽  
Vol 58 (6) ◽  
pp. 3844
Author(s):  
Wu Jun-Fang ◽  
Sun Ming-Zhao ◽  
Zhang Chun-Min
Keyword(s):  
Resonant Frequency ◽  
Cell Size ◽  
Frequency Band ◽  
Left Handed ◽  
The Relationship

scholarly journals Study of the Ferromagnetic Magnetite Resonance (Fe3O4) Forms of Thin Films Using Micromagnetic Simulation

2020 ◽  
Vol 3 (1) ◽  
pp. 10
Author(s):  
Syefira Salsabila ◽  
Lutfi Rohman ◽  
Endhah Purwandari
Keyword(s):  
Thin Film ◽  
Magnetic Material ◽  
Resonant Frequency ◽  
Frequency Band ◽  
Side Length ◽  
Hysteresis Curve ◽  
Absorption Frequency ◽  
Hard Magnetic Material ◽  
Thickness Variations ◽  
The Relationship

Fe3O4 is the strongest magnet among other iron oxides. Magnetite Fe3O4 is applied as a permanent magnet. The hysteresis curve of the permanent magnet Fe3O4 has a coercivity field that is not too large so that the material has a good chance to be applied as an absorbent material for RADAR waves. Micromagnetic simulations were carried out on Fe3O4 material in the form of thin film against hysteresis curves and ferromagnetic resonances at various thickness variations and side length variations, and the relationship was seen with changes in the bandwidth of the radar wave absorption frequency if the thickness variation of the simulated material had the same multiple as the experimental material. The thickness variations in this study were 60 nm, 90 nm, and 120 nm, where the variations in the experiment were 0.6 mm, 0.9 mm, and 1.2 mm. Micromagnetic simulation runs were performed to obtain the hysteresis curve and resonance frequency of the Fe3O4 material. The simulation results show that the resonant frequency increases with increasing thickness (fixed side length). Meanwhile, the relationship between the resonant frequency and the side length of the thin film is inversely related. Changes in the resonant frequency of Fe3O4 material are closely related to changes in the absorption frequency band of Fe3O4 material. The hysteresis curve obtained shows that the Fe3O4 material is a hard magnetic material. Changes in the resonant frequency of Fe3O4 material are closely related to changes in the absorption frequency band of Fe3O4 material. The hysteresis curve obtained shows that the Fe3O4 material is a hard magnetic material. Changes in the resonant frequency of Fe3O4 material are closely related to changes in the absorption frequency band of Fe3O4 material. The hysteresis curve obtained shows that the Fe3O4 material is a hard magnetic material.

scholarly journals Experimental-numerical studies of the effect of cell structure on the mechanical properties of polypropylene foams

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 713-723
Author(s):  
Wei Gong ◽  
Tuan-Hui Jiang ◽  
Xiang-Bu Zeng ◽  
Li He ◽  
Chun Zhang
Keyword(s):  
Mechanical Properties ◽  
Size Distribution ◽  
Cell Size ◽  
Cell Structure ◽  
Structure Parameters ◽  
Cell Size Distribution ◽  
Numerical Studies ◽  
Polypropylene Foam ◽  
The Impact ◽  
The Relationship

AbstractThe effects of the cell size and distribution on the mechanical properties of polypropylene foam were simulated and analyzed by finite element modeling with ANSYS and supporting experiments. The results show that the reduced cell size and narrow size distribution have beneficial influences on both the tensile and impact strengths. Decreasing the cell size or narrowing the cell size distribution was more effective for increasing the impact strength than the tensile strength in the same case. The relationship between the mechanical properties and cell structure parameters has a good correlation with the theoretical model.

scholarly journals The Relationship of Surgeon Handedness and Experience on Operative Duration and Hearing Improvement in Ipsilateral and Contralateral Otologic Surgeries

2020 ◽  
Vol 35 (2) ◽  
pp. 17
Author(s):  
Gillian Barzaga
Keyword(s):  
Hearing Improvement ◽  
Ear Surgery ◽  
Hearing Gain ◽  
Operative Duration ◽  
Left Handed ◽  
Significant Difference ◽  
Surgeon Experience ◽  
The Right ◽  
Relationship Of ◽  
The Relationship

ABSTRACT Objective: To determine the relationship of the surgeon handedness and operative site laterality on operative duration and hearing improvement in otologic surgery, and to further explore whether this relationship may be related to surgeon experience. Methods:Design: Retrospective CohortSetting: Tertiary Private Teaching HospitalParticipants: Seventy-three (73) patients aged 18 to 65 years old who underwent primary ear surgery under general anesthesia between January 2016 and December 2019 were retrospectively divided into two groups: 39 contralateral and 34 ipsilateral. The operative durations and hearing improvements were compared using independent t-tests, with consideration of surgeon experience in years further stratifying patients. Results: There was no significant difference in operative duration, t(71) = 1.14, p = .26, between the contralateral (M = 281.95 minutes, SD = 71.82) and ipsilateral (M = 261.15, SD = 79.26) groups. This same pattern was more pronounced among surgeons with 10+ years of experience although there was also no significant difference in operative time, t(33) = 1.31, p = .19 for both ipsilateral and contralateral surgeries There was no statistically significant difference, t(36) = -0.72, p = .47, in overall mean hearing gain among patients in the contralateral (M = +2.22 dB, SD = 10.54) and ipsilateral (M = +5.12 dB, SD = 14.26) groups. Although the difference was also not statistically significant, t(16) = -1.94, p = .07 for contralateral (M = 0.00, SD = 5.43) and ipsilateral (M = +7.95 dB, SD = 11.52) procedures performed by surgeons with experience of 10 years or more, a mean hearing gain of +7 dB in the ipsilateral group compared to 0 dB in the contralateral group was notable. Conclusion: This study did not prove that regardless of surgeon experience, right-handed surgeons operating on the right ear and left-handed surgeons operating on the left ear have better ear surgery outcomes of operative duration and hearing improvement compared to right- handed surgeons operating on the left ear and left-handed surgeons operating on the right ear. Future studies on larger samples with more complete data may yet demonstrate this effect.

scholarly journals A Chemical Screen Probing the Relationship between Mitochondrial Content and Cell Size

PLoS ONE ◽  
2012 ◽  
Vol 7 (3) ◽  
pp. e33755 ◽  
Author(s):  
Toshimori Kitami ◽  
David J. Logan ◽  
Joseph Negri ◽  
Thomas Hasaka ◽  
Nicola J. Tolliday ◽  
...  
Keyword(s):  
Cell Size ◽  
Mitochondrial Content ◽  
Chemical Screen ◽  
The Relationship

Improvement of Laterality Through the ABN Method in a Learning Enviroment in Early Education

2021 ◽  
pp. 33-54
Author(s):  
David Zamorano-Garcia ◽  
Paula Flores-Morcillo ◽  
María Isabel Gil-García ◽  
Miguel Ángel Aguilar-Jurado
Keyword(s):  
Early Childhood ◽  
Early Childhood Education ◽  
Physical Education ◽  
The Body ◽  
Childhood Education ◽  
Left Handed ◽  
And Mathematics ◽  
The Right ◽  
The Relationship ◽  
Shed Light

This chapter aims to shed light on the relationship between the development of laterality and the learning of mathematics in early childhood education using the ABN method. Thus, the authors present an experience developed with 24 children of 4 and 5 years old from several sessions of physical education where laterality and mathematics were worked on in the framework of a project developed in the classroom. The neuropsychological laterality test and a psychomotor table with values referred exclusively to manual and foot laterality, and indicators referred to the ABN method were used as evaluation instruments. The results obtained indicate that students with homogeneous right- or left-handed laterality obtain better results, as well as those with crossed laterality, since they have defined their manual and foot dominance. However, students with undefined laterality obtain worse results, even showing a lateral tendency towards the use of the right side of the body.

Cell structure and mechanical properties of microcellular PLA foams prepared via autoclave constrained foaming

2020 ◽  
pp. 026248932093032
Author(s):  
Jinwei Chen ◽  
Ling Yang ◽  
Dahua Chen ◽  
Qunshan Mai ◽  
Meigui Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Cell Size ◽  
Cell Structure ◽  
Saturation Pressure ◽  
Tensile Modulus ◽  
Cell Structures ◽  
Wide Range ◽  
The Mean ◽  
Constrained Foaming ◽  
The Relationship

Microcellular polylactic acid (PLA) foams with various cell size and cell morphologies were prepared using supercritical carbon dioxide (sc-CO2) solid-state foaming to investigate the relationship between the cell structure and mechanical properties. Constrained foaming was used and a wide range of cell structures with a constant porosity of ∼75% by tuning saturation pressure (8–24 MPa) was developed. Experiments varying the saturation pressure while holding other variables’ constant show that the mean cell size and the mean cell wall thickness decreased, while the cell density and the open porosity increased with increase of pressure. Tensile modulus of PLA foams decreased with increasing the saturation pressure, but the specific tensile modulus of PLA foams was still 15–80% higher than that of solid PLA. Tensile strength and elongation at break first increased with increasing saturation pressure up to 16 MPa and then decreased with further increasing saturation pressure (20 MPa and 24 MPa) at which opened-cell structure produced. Compressive modulus, compressive strength, and compressive yield stress also followed the same variation trend. The results indicated that not only cell size plays an important role in properties of PLA foams but also cell morphology can influence these properties significantly.

Relationships among changes of serum leptin concentration, leptin mRNA expression in white adipose tissue (WAT), and WAT fat-cell size in female Japanese black bears (Ursus thibetanus japonicus)

2008 ◽  
Vol 86 (9) ◽  
pp. 1042-1049 ◽  
Author(s):  
S. Nakamura ◽  
T. Okano ◽  
H. Shibata ◽  
M. Saito ◽  
T. Komatsu ◽  
...  
Keyword(s):  
Adipose Tissue ◽  
Reproductive Success ◽  
Cell Size ◽  
White Adipose Tissue ◽  
Black Bears ◽  
Fat Cell ◽  
Serum Leptin ◽  
Ursus Thibetanus ◽  
Fat Cell Size ◽  
The Relationship

As a first step to study the relationship between fat accumulation and reproductive success in Japanese black bears ( Ursus thibetanus japonicus Schlegel, 1857) with the focus on leptin, we determined leptin cDNA sequences in the bears. Next, we studied the possibility of white adipose tissue (WAT) as a leptin secretion source by observing the changes of leptin mRNA expression in WAT by semiquantitative real-time reverse transcript – polymerase chain reaction, the index of WAT fat-cell size, and serum leptin concentration in pregnant bears. Then, based on our results, we discussed roles of leptin in those bears. The amino acid sequences of leptin from the bears were highly identical to that of other carnivores. The expression of leptin mRNA in WAT was detected from September to January, with a tendency to increase in late November and January; the relationship between changes in the index of WAT fat-cell size and those in serum leptin concentration was high (r = 0.55, P < 0.01), with an increase in both in mid-November. These results suggested that leptin was mainly secreted from WAT in bears and that serum leptin concentrations might reflect their nutritional condition. Moreover, leptin might serve as an indicator of their fat mass, which would affect their survival during hibernation and their reproductive success.

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