Field sweep rate dependence of magnetic domain patterns: Numerical simulations for a simple Ising-like model

We study magnetic domain patterns in ferromagnetic thin films by numerical simulations for a simple Ising-like model. Magnetic domain patterns after quench demonstrate various types of patterns depending on the field sweep rate and parameters of the model. How the domain patterns are formed is shown with use of the number of domains, the domain area, and domain area distributions as well as snapshots of domain patterns. Considering the proper time scale of the system, we propose a criterion for the structure of domain patterns.Comment: 11 pages, 7 figure

Effects of an oscillating field on pattern formation in a ferromagnetic thin film: Analysis of patterns traveling at a low velocity

Magnetic domain patterns under an oscillating field is studied theoretically by using a simple Ising-like model. We propose two ways to investigate the effects of the oscillating field. The first one leads to a model in which rapidly oscillating terms are averaged out, and the model can explain the existence of the maximum amplitude of the field for the appearance of patterns. The second one leads to a model that includes the delay of the response to the field, and the model suggests the existence of a traveling pattern which moves very slowly compared with the time scale of the driving field.Comment: 9 pages, 3 figure

Energy diffusion in frustrated quantum spin chains exhibiting Gaussian orthogonal ensemble level statistics

Frustrated quantum $XXZ$ spin chains with the next-nearest-neighbor (NNN) couplings are typically deterministic many-body systems exhibiting Gaussian orthogonal ensemble (GOE) spectral statistics. We investigate energy diffusion for these spin chains in the presence of a periodically oscillating magnetic field. Diffusion coefficients are found to obey the power law with respect to both the field strength and driving frequency with its power varying depending on the linear response and non-perturbative regimes. The widths of the linear response and the non-perturbative regimes depend on the strength of frustrations. We have also elucidated a mechanism for oscillation of energy diffusion in the case of weakened frustrations.Comment: 6 pages, 6 figure

Novel erythrocyte pits in small tropical ruminant, lesser mouse deer.

We examined unique erythrocyte pits of the peripheral blood and bone marrow in the lesser mouse deer, Tragulus javanicus, using scanning electron microscope (SEM) and transmission electron microscope (TEM). Under the SEM observation, the pit was observed as a hole on both mature erythrocytes of the peripheral blood and immature erythrocytes of the bone marrow. By the TEM, the mature erythrocytes had a vacuole, which showed complicated shape and occupied considerable space within the cytoplasm. The vacuole was communicated extracellularly by perforation, which corresponded to the hole on the cell surface. In the bone marrow, erythroblast and reticulocytes have a cytoplasmic vacuole. This abnormal feature of the erythrocytes is peculiar to the mouse deer, and not found in other tropical ruminants. Despite the disadvantage of volume loss from the small erythrocytes, the mouse deer were healthy and showed no signs of anaemia

Two Cases of Chronic Gastritis with non-Helicobacter pylori Helicobacter Infection

Two men, 48 and 54 years of age, were referred for medical checkups without any particular symptoms. Upper gastrointestinal endoscopy showed a normal gastric body, but white marbled appearance in the lesser curvature of the gastric angle and antrum. Biopsy specimens revealed relatively long and tightly coiled organisms. The two patients were diagnosed as having non-Helicobacter pylori helicobacter (NHPH) infection according to the findings of pathological and quantitative reverse transcription-polymerase chain reaction (qRTPCR) analyses. After triple therapy (amoxicillin, clarithromycin, and rabeprazole), endoscopy showed an improvement of the white marbled lesions and biopsy specimens showed no NHPH. The white marbled appearance limited to the gastric angle and antrum may be a potential characteristic finding of NHPH-infected gastritis