5,676 research outputs found
Quantum Phase Transition from a Spin-liquid State to a Spin-glass State in the Quasi-1D Spin-1 System Sr1-xCaxNi2V2O8
We report a quantum phase transition from a spin-liquid state to a spin-glass
state in the quasi-one dimensional (1D) spin-1 system Sr1-xCaxNi2V2O8, induced
by a small amount of Ca-substitution at Sr site. The ground state of the parent
compound (x = 0) is found to be a spin-liquid type with a finite energy gap of
26.6 K between singlet ground state and triplet excited state. Both
dc-magnetization and ac-susceptibility studies on the highest Ca-substituted
compound (x = 0.05) indicate a spin-glass type magnetic ground state. With
increasing Ca-concentration, the spin-glass ordering temperature increases from
4.5 K (for the x = 0.015 compound) to 6.25 K (for the x = 0.05 compound). The
observed results are discussed in the light of the earlier experimental reports
and the theoretical predictions for a quasi-1D spin-1 system.Comment: 26 pages, 8 figures, 3 table
A Symbolic Interaction Analysis of Waria (Transgender Women) in Makassar - Eastern Indonesia
Transgender women (in Indonesia known as Waria) still experience social stigma and exclusion in society. This phenomenon is interesting to study because it is related to the existence of transgender women in dealing with stigma and social exclusion. This study aims to describe the way transgender women perceive social exclusion and to describe the construction of their knowledge which, despite facing social exclusion, still maintains their existence. This study used a qualitative-phenomenological study method, using a purposive sampling technique. Data collection was done by conducting observations, in-depth interviews, and documentation. Data were analyzed using qualitative descriptive using symbolic interaction theory. The results showed that transgender women perceive the stigma and social exclusion they faced was manifested by planned actions in the form of conditional neglect and delay in introducing their existence. They respond to social situations they face with adaptive and not frontal. Transgender women\u27s knowledge construction to maintain their existence is passed through four stages, namely impulse, perception, manipulation, and completion
Two-dimensional Induced Ferromagnetism
Magnetic properties of materials confined to nanometer length scales are
providing important information regarding low dimensional physics. Using
gadolinium based Langmuir-Blodgett films, we demonstrate that two-dimensional
ferromagnetic order can be induced by applying magnetic field along the
in-plane (perpendicular to growth) direction. Field dependent exchange coupling
is evident in the in-plane magnetization data that exhibit absence of
hysteresis loop and show reduction in field required to obtain saturation in
measured moment with decreasing temperature.Comment: 4 pages, 3 postscript figures, corrected paper forma
Magnetocaloric effect and critical behavior near the paramagnetic to ferrimagnetic phase transition temperature in TbCo2-xFex
Magnetocaloric effect (MCE) in TbCo2-xFex has been studied by dc
magnetization measurements.On substituting Fe in TbCo2, not only the magnetic
transition temperature is tuned to room temperature, but also the operating
temperature range for MCE is increased from 50 K for TbCo2 to 95 K for
TbCo1.9Fe0.1. The maximum magnetic entropy change (-{\Delta}SM) for
TbCo1.9Fe0.1 is found to be 3.7 J kg-1 K-1 for a 5 T field change, making it a
promising candidate for magnetic refrigeration near room temperature. The
temperature dependent neutron diffraction study shows a structural phase
transition (from cubic to rhombohedral phase with lowering of temperature)
which is associated with the magnetic phase transition and these transitions
broaden on Fe substitution. To investigate the nature of the paramagnetic to
ferrimagnetic phase transition, we performed a critical exponent study. From
the derived values of critical exponents, we conclude that TbCo2 belongs to the
3D Heisenberg class with short-range interaction, while on Fe substitution it
tends towards mean-field with long-range interaction. The derived values of
critical exponents represent the phenomenological universal curve for the field
dependence of {\Delta}SM, indicating that TbCo2 and TbCo1.9Fe0.1 belong to two
different universality classes.Comment: 12 figure
Long-range and short-range magnetic correlations, and microscopic origin of net magnetization in the spin-1 trimer chain compound CaNi3P4O14
Spin-spin correlations and microscopic origin of net magnetization in the
spin-1 trimer chain compound CaNi3P4O14 have been investigated by powder
neutron diffraction. The present study reveals a 3D long-range magnetic
ordering below 16 K where the magnetic structure consists of ferromagnetic
trimers that are coupled ferromagnetically along the spin-chain. The moment
components along the a and c axes arrange antiferromagnetically. Our study
establishes that the uncompensated moment components along the b axis result in
a net magnetization per unit cell. The magnetic structure, determined in the
present study, is in agreement with the results of recent first principles
calculation; however, it is in contrast to a fascinating experimental
prediction of ferrimagnetic ordering based on the periodicity of the exchange
interactions in CaNi3P4O14. Our study also confirms the presence of broad
diffuse magnetic scattering, due to 1D short-range spin-spin correlations, over
a wide temperature range below ~50 K down to a temperature well below the Tc.
Total neutron scattering analysis by the RMC method reveals that the dominating
spin-spin correlation above Tc is ferromagnetic and along the b axis. The
nearest neighbour spin-spin correlations along the a and c axes are found to be
weakly antiferromagnetic. The nature of the trimer spin structure of the
short-range state is similar to that of the 3D long-range ordered state. The
present investigation of microscopic nature of the magnetic ground state also
explains the condition required for the 1/3 magnetization plateau to be
observed in the trimer spin-chains. In spite of the S=1 trimer chain system,
the present compound CaNi3P4O14 is found to be a good realization of 3D magnet
below the Tc=16 K with full ordered moment values of ~2 mu_B/Ni2+ (1.98 and
1.96 mu_B/Ni2+ for two Ni sites, respectively) at 1.5 K.Comment: 10 pages, 8 figure
Enhanced grain surface effect on magnetic properties of nanometric La0.7Ca0.3MnO3 manganite : Evidence of surface spin freezing of manganite nanoparticles
We have investigated the effect of nanometric grain size on magnetic
properties of single phase, nanocrystalline, granular La0.7Ca0.3MnO3 (LCMO)
sample. We have considered core-shell structure of our LCMO nanoparticles,
which can explain its magnetic properties. From the temperature dependence of
field cooled (FC) and zero-field cooled (ZFC) dc magnetization (DCM), the
magnetic properties could be distinguished into two regimes: a relatively high
temperature regime T > 40 K where the broad maximum of ZFC curve (at T = Tmax)
is associated with the blocking of core particle moments, whereas the sharp
maximum (at T = TS) is related to the freezing of surface (shell) spins. The
unusual shape of M (H) loop at T = 1.5 K, temperature dependent feature of
coercive field and remanent magnetization give a strong support of surface spin
freezing that are occurring at lower temperature regime (T < 40 K) in this LCMO
nanoparticles. Additionally, waiting time (tw) dependence of ZFC relaxation
measurements at T = 50 K show weak dependence of relaxation rate [S(t)] on tw
and dM/dln(t) following a logarithmic variation on time. Both of these features
strongly support the high temperature regime to be associated with the blocking
of core moments. At T = 20 K, ZFC relaxation measurements indicates the
existence of two different types of relaxation processes in the sample with
S(t) attaining a maximum at the elapsed time very close to the wait time tw =
1000 sec, which is an unequivocal sign of glassy behavior. This age-dependent
effect convincingly establish the surface spin freezing of our LCMO
nanoparticles associated with a background of superparamagnetic (SPM) phase of
core moments.Comment: 41 pages, 10 figure
Analisis RAPD ( Random Amplified Polymorphic DNA)untuk Diferensiasi Mycobacteriun tuberculosis isolat klinik sensitif INH dan Rifampisin di Makassar
This study aims to find out: (1) whether there is a genetic diversity on M.tuberculosis isolat clinic that is sensitif to INH dan rifampisin with RAPD method, and (2) the description of its
polimorfism diferentiation. The research samples include 5 Mycobacteriun tuberculosis isolate that is sensitive to INH and rifampisin. The study includes DNA extraction using Wizard Genom DNA
purification method, amplification using 5 primer: A-2 (5 TGCCGAGTCG 3 , 70% G+C ), OPN-09 ( 5TGCCGGCTTG 3, 70% G+C), N-9 (5 TGCCGGCTTG 3, 70% G+C), BG-66 (5CGACGCTGCG 3, 80% G+C) , 80% G+C), U-19 ( 5 GTCAGTGCGG 3, 70% G+C), and
electroforesis. The isolat genetic diversity was analysed by using Dendro Unweighted Pair Group Method of Aritmethic (UPGMA) : A Dendogram Construction Utility method from Dr. Santi GarciaValive/2009. The results show that there is a genetic diversity on the 5 isolate Mycobacterium
tuberculosis that are sensitive to INH and rifampisin, amplified with 5 primer. The size of amplified DNA bands is between 200-1100bp. The genetic variation can be seen in the number of fragments, the
size of fragments and the number of polimorfik bands. The polimorfik percentage of the isolate is between 66.67% - 100%, or 80.28 in average. The UPGMA analysis results in a dendogram with a
group cooficient of 0 40% or a diversity of 60 100%.
Keywords: RAPD, Mycobacterium tuberculosis, sensitive to INH and rifampisin
The Role of Education in Preventing Honour-Based Abuse in England
Honour-based abuse (HBA) is a form of abuse that frequently remains undetected despite its pervasive nature and catastrophic effects. As an act of violence perpetrated predominantly against women and girls, HBA is the overarching term used for abuse inflicted upon victims because they have supposedly dishonoured their family and brought shame to their community. To date, there is a paucity of research that specifically explores the role of education in preventing HBA in England. In seeking to strengthen and advance knowledge in this area, this research aims to gain insights into the perspectives of key participants about the cross-cultural and contested nature of HBA, including the factors contributing to it, the ramifications for local and national policy, and the role of education in preventing HBA in the context of England. This thesis also illustrates how the insidious and invidious practices of HBA continue to be perpetuated toward the most vulnerable within society. Underpinned by a feminist theoretical framework, qualitative analysis was employed to explore how participants perceive how education may contribute to prevention of HBA. The research participants interviewed for this study, over a period of eight months, included four activists, three politicians, one Home Office senior civil servant, four academics, two Crown Prosecution Service (CPS) staff, and one senior police officer. The semi-structured interviews provided a comprehensive understanding of the significance and meaning that the research participants placed on the role of education in HBA, and HBA prevention. Thematic analysis was undertaken after the data was transcribed and input into NVivo to detect themes, identify codes, and define key themes and underlying subthemes. This analysis uncovered five key themes within this research inquiry. The first theme related to the definitions and practices of HBA and exploring participant perceptions of the elements that contribute to and influence HBA. The second theme identified the origins and perpetuations of HBA. In broad terms, this theme focused on the origins of the cultural practice, identified the trigger factors, and examined the impact of gender and patriarchy in relation to HBA. The third theme was in relation to identification and definition of perpetrators and victims. The fourth theme provided an overview of the positionality of the research participants including their backgrounds, roles, and responsibilities. The fifth theme explored solutions to HBA, including methods of eradication, taking into account interviewees’ views on how to address HBA, and the role of education and government organisations in preventing HBA.
Whilst it was clear that steps have been taken by the State to address the phenomenon of HBA through community initiatives and statutory education, the impact of these initiatives on HBA was limited due to several factors, such as lack of effective training for teachers, community literacy in HBA, race relations within the migrant community, funding constraints, and the multiple viewpoints and experiences due to the intersectional nature of HBA. Weaving through the tapestry of migration, culture, discrimination, gender norms, and societal roles, this research generates new understandings on the role of education in preventing HBA in England by drawing on the views of key participants on policies and initiatives related to HBA
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