High-field phase diagram of the Haldane-gap antiferromagnet Ni(C5H14N2)2N3(PF6)Ni (C_5 H_{14} N_2)_2 N_3 (PF_6)

We have determined the magnetic phase diagram of the quasi-one-dimensional $S=$ 1 Heisenberg antiferromagnet $Ni (C_5 H_{14} N_2)_2 N_3 (PF_6)$ 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 $H_{c2}\approx 14$ 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 $H_c$, 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 S=1S = 1 spin-dimer antiferromagnet Ba3_3Mn2_2O8_8 in high magnetic fields

We have measured the specific heat of the coupled spin-dimer antiferromagnet Ba$_3$Mn$_2$O$_8$ 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 $\leq H \leq$ 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 CeRu2_2Si2_2 near Absolute Zero Observed by Thermal Expansion and Magnetostriction

We report linear thermal expansion and magnetostriction measurements for CeRu$_2$Si$_2$ 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 elämänlaatuun masentuneella henkilöllä.

Opinnäytetyön tavoitteena on kerätä tietoa rentoutumisesta, unesta ja masennuksesta sekä selvittää rentoutumisen vaikutuksia uneen ja koettuun elämänlaatuun masentuneella henkilöllä. Opinnäytetyön tarkoitus meille tekijöille on syventää tietämystä rentoutumisen vaikutuksista masentuneella henkilöllä, hankkia kokemusta tulevaa työelämää varten sekä verkostoitua tekijöitä kiinnostavalle fysioterapian osa-alueelle. Opinnäytetyön tarkoitus toimeksiantajalle ja fysioterapia-alalle on tuottaa tietoa, jota voidaan hyödyntää masentuneen henkilön fysioterapiassa. Opinnäytetyön toimeksiantaja on Lapin sairaanhoitopiirin psykiatrian klinikka. Opinnäytetyössä vastataan kysymyksiin, millaisia vaikutuksia hengitysrentoutusharjoituksella on masentuneen henkilön uneen sekä millaisia vaikutuksia rentoutumisella on masentuneen henkilön koettuun elämänlaatuun. Tutkimus toteutettiin tapaustutkimuksena viiden viikon rentoutuskurssina keväällä 2015. Tutkimuksessa haettiin vastauksia tutkimusongelmiin määrällisin menetelmin. Mittareina aineiston kokoamisessa toimivat Firstbeat-mittari sekä Sintosen 15D-elämänlaatukysely. Firstbeat-mittarilla mitattiin stressireaktioiden osuutta sekä palautumista unen aikana ja Sintosen 15D-elämänlaatukyselyllä koettua elämänlaatua. Firstbeat-mittaus suoritettiin hengitysrentoutusharjoitusta edeltävänä ja jälkeisenä yönä rentoutuskurssin toisella ja viimeisellä viikolla. Elämänlaatukysely toteutettiin rentoutuskurssin ensimmäisellä ja viimeisellä kerralla. Tutkimus on tapaustutkimus ja tutkimuksen kohteena on yksi masentunut henkilö. Tutkimusaineisto analysoitiin Firstbeat-mittarin tulosten osalta Microsoft Word-taulukoiden avulla. Sintosen 15D-elämänlaatukyselyn tulokset on analysoitu Sintosen kehittelemän valmiin Excel-pohjan, arvotusalgoritmin, avulla. Mittaustulosten perusteella rentoutumisella on positiivisia vaikutuksia stressireaktioiden osuuteen sekä palautumiseen unen aikana ja koettuun elämänlaatuun masentuneella henkilöllä. Tutkimushenkilön stressireaktioiden ja palautumisen osuus sekä palautumisen laatu paranivat hengitysrentoutusharjoituksen jälkeisenä yönä verrattuna edeltävään yöhön. Elämänlaatukyselyn mukaan tutkimushenkilön näkö, kuulo, nukkuminen, puhuminen, henkinen toiminta, vaivat ja oireet, ahdistuneisuus ja sukupuolielämä paranivat tai helpottivat rentoutuskurssin aikana. Tutkimuksessa saatuja tuloksia ei voi yleistää kaikilla masentuneilla, mutta tuloksia voidaan hyödyntää 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 researchers’ 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: “What are the effects of breathing relaxation for sleep?” and “What 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-Sintonen’s questionnaire. Firstbeat-measurement was administrated during sleep, before and after the breathing relaxation during the second and the last week of the relaxation course. Sintonen’s 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