Ferromagnetism in a hard-core boson model

The problem of ferromagnetism -- associated with a ground state with maximal total spin -- is discussed in the framework of a hard-core model, which forbids the occupancy at each site with more than one particle. It is shown that the emergence of ferromagnetism on finite square lattices crucially depends on the statistics of the particles. Fermions (electrons) lead to the well-known instabilities for finite hole densities, whereas for bosons (with spin) ferromagnetism appears to be stable for all hole densities.Comment: 8 pages, 7 figures, RevTex

Recent Developments of World-Line Monte Carlo Methods

World-line quantum Monte Carlo methods are reviewed with an emphasis on breakthroughs made in recent years. In particular, three algorithms -- the loop algorithm, the worm algorithm, and the directed-loop algorithm -- for updating world-line configurations are presented in a unified perspective. Detailed descriptions of the algorithms in specific cases are also given.Comment: To appear in Journal of Physical Society of Japa

On the use of STM superconducting tips at very low temperatures

We report on high quality local tunnel spectroscopy measurements in superconductors using in-situ fabricated superconducting tips as counterelectrode. The experiments were made at very low temperatures using a dilution refrigerator and a 3He cryostat. Spectra obtained with superconducting tip and sample of Al show that the spectroscopic resolution of our set-up is of 15 microeV . Following the observation of Josephson current in tunneling regime (with tips of Pb and of Al), we discuss the feasibility of Scanning Josephson Spectroscopy with atomic size resolution. Experiments showing new applications of these superconducting tips under applied external magnetic fields are also reported.Comment: PDF file, 8 pages, accepted for publication in The European Physical Journal B, for the topical issue on Colective phenomena in Mesoscopic system

THE INFLUENCE OF INFORMAL FACULTY-STUDENT RELATIONSHIP ON STUDENTS' MOTIVATION

Informal relationships between faculty members and students are a necessary element of the educational process in higher education. Furthermore, student motivation plays a significant role in a student's success. Although several studies have explored the effect of informal relationships between students and faculty on student motivation, very few studies have been conducted on this topic in Kazakhstan. Thus, this study intends to reduce this gap. This study aims to explore the effects of informal student-faculty relationships on students' motivation at one Kazakhstani university's pedagogical institute. These are the questions the study is intended to answer: RQ1: How do students characterize their relationship with faculty members? RQ2: How do students' gender and age affect student-faculty relationships and students' motivation? RQ3: Can student social interactions predict students' motivation? In order to answer these research questions, quantitative non-experimental research designs were used. One hundred sixty-one undergraduates over 18 of one Kazakhstani university's pedagogical institute were surveyed online. This research reveals that students are optimistic about their informal relationships with faculty members. Moreover, the study found that age and gender modestly affect student-faculty relationships and students' motivation. Furthermore, the results of this study show that the informal relationship of the faculty with students significantly affects students' motivation. This study definitively answers the question regarding the effects of informal student-faculty relationships on students' motivation. The benefit of this research to faculty administrators and policymakers is to improve the relationship between faculty and students outside the classroom at Kazakhstani universities

Using cavitation effects in the ultrasonic cleaning of anilox rolls

В работе приводится анализ и изучение технологических особенностей процессов очистки анилоксовых валов, а также их влияние на качество эксплуатационных свойств. Так как доля флексографской печати в общем рынке полиграфических услуг постоянно расширяется, то это указывает на актуальность данной темы и ее значимость. Научная идея заключается в оптимизации влияния ультразвукового фактора и химического воздействия.У роботі наводиться аналіз і вивчення технологічних особливостей процесів очищення анілоксових валів, а також їх вплив на якість експлуатаційних властивостей. Через те, що частка флексографічного друку в загальному ринку поліграфічних послуг постійно розширюється, то це вказує на актуальність даної теми та її значущість. Наукова ідея полягає в оптимізації впливу утразвукового фактора і хімічного впливу.The paper analyzes and studies the technological features of anilox roll cleaning processes, as well as their impact on the quality of operational properties. Since the share of flexographic printing in the general market of printing services is constantly expanding, this indicates the relevance of this topic and its significance. The scientific idea is to optimize the influence of the nonsound factor and the chemical effect