scholarly journals Revealing the mystery of the cases where Nd–Fe–B magnetic like poles attract each other

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hui Meng ◽  
Guiping Tang ◽  
Abby Shen ◽  
Michelle Qian ◽  
Qifeng Wei ◽  
...  

AbstractThis investigation reveals the mystery of the cases where magnetic like poles attract each other, and unlike poles repel one another. It is identified that for two unequally sized like poles, the pole with a higher Pc (permeance coefficient) causes a localized demagnetization (LD) to the pole with a lower Pc. If the LD is large enough, the polarity of a localized area can be reversed, resulting in an attraction between these two like poles in the LD area in a small gap. Two unusual behaviors are observed: (1) an inflection point IP appears on the force vs gap curves of all the unequally sized like poles since they have different Pc. Normally, the like poles’ repelling force increases when the gap decreases, but this IP results in nonmonotonic curves, even an attractive force in a small gap; (2) for some NdFeB magnets with a low coercivity and nonlinear B–H curve in the 2nd quadrant, a repulsion can occur for these unequal sized unlike poles, after previously pairing with their like poles that left an unrecoverable LD and reversed polarity area. The relationship of the LD, the Pc ratio, and the B–H curve are also explored in this paper.

2015 ◽  
Vol 731 ◽  
pp. 295-299
Author(s):  
Ye Chi Pang ◽  
Zhi Jie Li ◽  
Li Lin Shi

In the offset printing process, the amount of ink supplying of fountain directly affects plate ink thickness, thereby affecting the color quality on the printed sheet. Ink layer thickness is difficult to judge by human eye, but we can regulate the ink thickness by detecting the color saturation. This paper describes using complex spectrum spectrometer measured data ink layer thickness and color saturation, draw two graphs of complex spectrum saturation and CIE saturation. Due to the different definitions of saturation, Cause their sensitivity of layer thickness changes response different. Two sets of data shows that the complex spectrum saturation contrast ΔS1 significantly higher than CIE saturation contrast. The data also showed that the ink color performance in terms of the relationship between layer thickness and saturation has an inflection point, the inflection point in the ink film thickness about 4μm, after reaching inflection point, even if the ink layer thickness continues to increase, there will be no significant changes in the saturation.


Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.


Author(s):  
D. F. Blake ◽  
L. F. Allard ◽  
D. R. Peacor

Echinodermata is a phylum of marine invertebrates which has been extant since Cambrian time (c.a. 500 m.y. before the present). Modern examples of echinoderms include sea urchins, sea stars, and sea lilies (crinoids). The endoskeletons of echinoderms are composed of plates or ossicles (Fig. 1) which are with few exceptions, porous, single crystals of high-magnesian calcite. Despite their single crystal nature, fracture surfaces do not exhibit the near-perfect {10.4} cleavage characteristic of inorganic calcite. This paradoxical mix of biogenic and inorganic features has prompted much recent work on echinoderm skeletal crystallography. Furthermore, fossil echinoderm hard parts comprise a volumetrically significant portion of some marine limestones sequences. The ultrastructural and microchemical characterization of modern skeletal material should lend insight into: 1). The nature of the biogenic processes involved, for example, the relationship of Mg heterogeneity to morphological and structural features in modern echinoderm material, and 2). The nature of the diagenetic changes undergone by their ancient, fossilized counterparts. In this study, high resolution TEM (HRTEM), high voltage TEM (HVTEM), and STEM microanalysis are used to characterize tha ultrastructural and microchemical composition of skeletal elements of the modern crinoid Neocrinus blakei.


Author(s):  
Leon Dmochowski

Electron microscopy has proved to be an invaluable discipline in studies on the relationship of viruses to the origin of leukemia, sarcoma, and other types of tumors in animals and man. The successful cell-free transmission of leukemia and sarcoma in mice, rats, hamsters, and cats, interpreted as due to a virus or viruses, was proved to be due to a virus on the basis of electron microscope studies. These studies demonstrated that all the types of neoplasia in animals of the species examined are produced by a virus of certain characteristic morphological properties similar, if not identical, in the mode of development in all types of neoplasia in animals, as shown in Fig. 1.


Author(s):  
J.R. Pfeiffer ◽  
J.C. Seagrave ◽  
C. Wofsy ◽  
J.M. Oliver

In RBL-2H3 rat leukemic mast cells, crosslinking IgE-receptor complexes with anti-IgE antibody leads to degranulation. Receptor crosslinking also stimulates the redistribution of receptors on the cell surface, a process that can be observed by labeling the anti-IgE with 15 nm protein A-gold particles as described in Stump et al. (1989), followed by back-scattered electron imaging (BEI) in the scanning electron microscope. We report that anti-IgE binding stimulates the redistribution of IgE-receptor complexes at 37“C from a dispersed topography (singlets and doublets; S/D) to distributions dominated sequentially by short chains, small clusters and large aggregates of crosslinked receptors. These patterns can be observed (Figure 1), quantified (Figure 2) and analyzed statistically. Cells incubated with 1 μg/ml anti-IgE, a concentration that stimulates maximum net secretion, redistribute receptors as far as chains and small clusters during a 15 min incubation period. At 3 and 10 μg/ml anti-IgE, net secretion is reduced and the majority of receptors redistribute rapidly into clusters and large aggregates.


1993 ◽  
Vol 2 (3) ◽  
pp. 52-55 ◽  
Author(s):  
Michael Collins ◽  
Robert McDonald ◽  
Robert Stanley ◽  
Timothy Donovan ◽  
C. Frank Bonebrake

This report describes an unusual and persistent dysphonia in two young women who had taken a therapeutic regimen of isotretinoin for intractable acne. We report perceptual and instrumental data for their dysphonia, and pose a theoretical basis for the relationship of dysphonia to this drug. We also provide recommendations for reducing the risk of acquiring a dysphonia during the course of treatment with isotretinoin.


2019 ◽  
Vol 28 (2) ◽  
pp. 245-250
Author(s):  
Ann E. Perreau ◽  
Richard S. Tyler ◽  
Patricia C. Mancini ◽  
Shelley Witt ◽  
Mohamed Salah Elgandy

Purpose Audiologists should be treating hyperacusis patients. However, it can be difficult to know where to begin because treatment protocols and evidence-based treatment studies are lacking. A good place to start in any tinnitus and hyperacusis clinic is to incorporate a group educational session. Method Here, we outline our approach to establishing a hyperacusis group educational session that includes specific aspects of getting to know each patient to best meet their needs, understanding the problems associated with hyperacusis, explaining the auditory system and the relationship of hyperacusis to hearing loss and tinnitus, describing the influence of hyperacusis on daily life, and introducing treatment options. Subjective responses from 11 adults with hyperacusis, who participated in a recent clinical group education session, were discussed to illustrate examples from actual patients. Conclusions Due to the devastating nature of hyperacusis, patients need to be reassured that they are not alone and that they can rely on audiologists to provide support and guidance. A group approach can facilitate the therapeutic process by connecting patients with others who are also affected by hyperacusis, and by educating patients and significant others on hyperacusis and its treatment options. Supplemental Material https://doi.org/10.23641/asha.8121197


2010 ◽  
Vol 20 (1) ◽  
pp. 3-8
Author(s):  
Dee Adams Nikjeh

Abstract Administrators and supervisors face daily challenges over issues such as program funding, service fees, correct coding procedures, and the ever-changing healthcare regulations. Receiving equitable reimbursement for speech-language pathology and audiology services necessitates an understanding of federal coding and reimbursement systems. This tutorial provides information pertaining to two major healthcare coding systems and explains the relationship of these systems to clinical documentation, the Medicare Physician Fee Schedule and equitable reimbursement. An explanation of coding edits and coding modifiers is provided for use in those occasional atypical situations when the standard use of procedural coding may not be appropriate. Also included in this tutorial is a brief discussion of the impact that the Medicare Improvements for Patients and Providers Act of 2008 (HR 6331 Medicare Improvements for Patients and Providers Act [MIPPA], 2008) has had on the valuation of speech-language pathology procedure codes.


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