886 research outputs found
High-field phase diagram of the Haldane-gap antiferromagnet
We have determined the magnetic phase diagram of the quasi-one-dimensional
1 Heisenberg antiferromagnet by
specific heat measurements to 150 mK in temperature and 32 T in magnetic field.
When field is applied along the spin-chain direction, a new phase appears at
T. For the previously known phases of field-induced order,
accurate determination is made of the power-law exponents of the ordering
temperature near the zero-temperature critical field , owing to the
four-fold improvement of the minimum temperature over the previous work. The
results are compared with the predictions based on the Bose-Einstein
condensation of triplet excitations. Substituting deuterium for hydrogen is
found to slightly reduce the interchain exchange.Comment: 6 pages, 6 figure
Specific heat of the spin-dimer antiferromagnet BaMnO in high magnetic fields
We have measured the specific heat of the coupled spin-dimer antiferromagnet
BaMnO to 50 mK in temperature and to 29 T in the magnetic field.
The experiment extends to the midpoint of the field region (25.9 T 32.3 T) of the magnetization plateau at 1/2 of the saturation
magnetization, and reveals the presence of three ordered phases in the field
region between that of the magnetization plateau and the low-field spin-liquid
region. The exponent of the phase boundary with the thermally disordered region
is smaller than the theoretical value based on the Bose-Einstein condensation
of spin triplets. At zero field and 29 T, the specific-heat data show gapped
behaviors characteristic of spin liquids. The zero-field data indicate that the
gapped triplet excitations form two levels whose energies differ by nearly a
factor of two. At least the lower level is well localized. The data at 29 T
reveal that the low-lying excitations at the magnetization plateau are weakly
delocalized.Comment: 6 pages, 5 figures, revised versio
Novel Quantum Criticality in CeRuSi near Absolute Zero Observed by Thermal Expansion and Magnetostriction
We report linear thermal expansion and magnetostriction measurements for
CeRuSi in magnetic fields up to 52.6 mT and at temperatures down to 1
mK. At high temperatures, this compound showed Landau-Fermi-liquid behavior:
The linear thermal expansion coefficient and the magnetostriction coefficient
were proportional to the temperature and magnetic field, respectively. In
contrast, a pronounced non-Fermi-liquid effect was found below 50 mK. The
negative contribution of thermal expansion and magnetostriction suggests the
existence of an additional quantum critical point
Rentoutumisen vaikutuksia uneen ja koettuun elÀmÀnlaatuun masentuneella henkilöllÀ.
OpinnÀytetyön tavoitteena on kerÀtÀ tietoa rentoutumisesta, unesta ja masennuksesta sekÀ selvittÀÀ rentoutumisen vaikutuksia uneen ja koettuun elÀmÀnlaatuun masentuneella henkilöllÀ. OpinnÀytetyön tarkoitus meille tekijöille on syventÀÀ tietÀmystÀ rentoutumisen vaikutuksista masentuneella henkilöllÀ, hankkia kokemusta tulevaa työelÀmÀÀ varten sekÀ verkostoitua tekijöitÀ kiinnostavalle fysioterapian osa-alueelle. OpinnÀytetyön tarkoitus toimeksiantajalle ja fysioterapia-alalle on tuottaa tietoa, jota voidaan hyödyntÀÀ masentuneen henkilön fysioterapiassa. OpinnÀytetyön toimeksiantaja on Lapin sairaanhoitopiirin psykiatrian klinikka. OpinnÀytetyössÀ vastataan kysymyksiin, millaisia vaikutuksia hengitysrentoutusharjoituksella on masentuneen henkilön uneen sekÀ millaisia vaikutuksia rentoutumisella on masentuneen henkilön koettuun elÀmÀnlaatuun.
Tutkimus toteutettiin tapaustutkimuksena viiden viikon rentoutuskurssina kevÀÀllÀ 2015. Tutkimuksessa haettiin vastauksia tutkimusongelmiin mÀÀrÀllisin menetelmin. Mittareina aineiston kokoamisessa toimivat Firstbeat-mittari sekÀ Sintosen 15D-elÀmÀnlaatukysely. Firstbeat-mittarilla mitattiin stressireaktioiden osuutta sekÀ palautumista unen aikana ja Sintosen 15D-elÀmÀnlaatukyselyllÀ koettua elÀmÀnlaatua. Firstbeat-mittaus suoritettiin hengitysrentoutusharjoitusta edeltÀvÀnÀ ja jÀlkeisenÀ yönÀ rentoutuskurssin toisella ja viimeisellÀ viikolla. ElÀmÀnlaatukysely toteutettiin rentoutuskurssin ensimmÀisellÀ ja viimeisellÀ kerralla. Tutkimus on tapaustutkimus ja tutkimuksen kohteena on yksi masentunut henkilö. Tutkimusaineisto analysoitiin Firstbeat-mittarin tulosten osalta Microsoft Word-taulukoiden avulla. Sintosen 15D-elÀmÀnlaatukyselyn tulokset on analysoitu Sintosen kehittelemÀn valmiin Excel-pohjan, arvotusalgoritmin, avulla.
Mittaustulosten perusteella rentoutumisella on positiivisia vaikutuksia stressireaktioiden osuuteen sekĂ€ palautumiseen unen aikana ja koettuun elĂ€mĂ€nlaatuun masentuneella henkilöllĂ€. Tutkimushenkilön stressireaktioiden ja palautumisen osuus sekĂ€ palautumisen laatu paranivat hengitysrentoutusharjoituksen jĂ€lkeisenĂ€ yönĂ€ verrattuna edeltĂ€vÀÀn yöhön. ElĂ€mĂ€nlaatukyselyn mukaan tutkimushenkilön nĂ€kö, kuulo, nukkuminen, puhuminen, henkinen toiminta, vaivat ja oireet, ahdistuneisuus ja sukupuolielĂ€mĂ€ paranivat tai helpottivat rentoutuskurssin aikana. Tutkimuksessa saatuja tuloksia ei voi yleistÀÀ kaikilla masentuneilla, mutta tuloksia voidaan hyödyntÀÀ suunniteltaessa masentuneiden fysioterapiaa. Tutkimuksen tulokset houkuttelevat myös suorittamaan erilaisia jatkotutkimuksia.The aim of this thesis is to gather information on relaxation, sleep and depression and to assess how relaxation may affect sleep and quality of life of a person affected by depression. The purpose of this study is to enhance the researchersâ knowledge on the effects of relaxation of a person affected by depression and achieve experience for the future, also creating relations in physiotherapy sector. The purpose of this study, commissioned by The Lapland Hospital District and the Psychiatric clinic, is to produce knowledge useful for planning physiotherapy meant to a person affected by depression. This thesis responds to the research questions: âWhat are the effects of breathing relaxation for sleep?â and âWhat are the effects for quality of life of person with depression?"
This is a case-study was developed during a five-week relaxation course in the spring of 2015. In this case-study quantitative research methods were used. The indicators are Firstbeat-meter and Sintonen 15D-quality of life-questionnaire. Stress reactions and recovery during sleep were measured by using Firstbeat-meter, and quality of life is measured by using Sintonen 15D-quality of life-Sintonenâs questionnaire. Firstbeat-measurement was administrated during sleep, before and after the breathing relaxation during the second and the last week of the relaxation course. Sintonenâs 15D-quality of life questionnaire was administrated during the first and the last session of the relaxation course. This case-study analyses one person affected by depression. The data was analyzed by using the Microsoft Word-sheet program and the Excel-sheet algorithm made by Sintonen.
Based on the results, relaxation has positive effects on stress reactions and recovery during sleep, as well as on the quality of life of a person affected by depression. In comparison to the previous night, stress reactions, part of the recovery, and the quality of the recovery of the person improved after breathing relaxation.
Sintonen 15D-life questionnaire shows that vision, hearing, sleeping, speaking, mental functions, discomfort and symptoms anxiety and sexual life improved during the relaxation course. The results of this study cannot be generalized; nevertheless, they can be useful for planning physiotherapy for people affected by depression. The results of the study may also suggest to perform further research on this specific topic
Single crystal MgB2 with anisotropic superconducting properties
The discovery of superconductor in magnesium diboride MgB2 with high Tc (39
K) has raised some challenging issues; whether this new superconductor
resembles a high temperature cuprate superconductor(HTS) or a low temperature
metallic superconductor; which superconducting mechanism, a phonon- mediated
BCS or a hole superconducting mechanism or other new exotic mechanism may
account for this superconductivity; and how about its future for applications.
In order to clarify the above questions, experiments using the single crystal
sample are urgently required. Here we have first succeeded in obtaining the
single crystal of this new MgB2 superconductivity, and performed its electrical
resistance and magnetization measurements. Their experiments show that the
electronic and magnetic properties depend on the crystallographic direction.
Our results indicate that the single crystal MgB2 superconductor shows
anisotropic superconducting properties and thus can provide scientific basis
for the research of its superconducting mechanism and its applications.Comment: 7 pages pdf fil
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