37 research outputs found
Rotating sample magnetometer for cryogenic temperatures and high magnetic fields
We report on the design and implementation of a rotating sample magnetometer
(RSM) operating in the variable temperature insert of a cryostat equipped with
a high-field magnet. The limited space and the cryogenic temperatures impose
the most critical design parameters: the small bore size of the magnet requires
a very compact pick-up coil system and the low temperatures demand a very
careful design of the bearings. Despite these difficulties the RSM achieves
excellent resolution at high magnetic field sweep rates, exceeding that of a
typical vibrating sample magnetometer by about a factor of ten. In addition the
gas-flow cryostat and the high-field superconducting magnet provide a
temperature and magnetic field range unprecedented for this type of
magnetometer.Comment: 10 pages, 5 figure
Anisotropic critical currents in FeSe0.5Te0.5 films and the influence of neutron irradiation
We report on measurements of the superconducting properties of FeSe05Te05
thin films grown on lanthanum aluminate. The films have high transition
temperatures (above 19 K) and sharp resistive transitions in fields up to 15 T.
The temperature dependence of the upper critical field and the irreversibility
lines are steep and anisotropic, as recently reported for single crystals. The
critical current densities, assessed by magnetization measurements in a vector
VSM, were found to be well above 10^9 Am-2 at low temperatures. In all samples,
the critical current as a function of field orientation has a maximum, when the
field is oriented parallel to the film surface. The maximum indicates the
presence of correlated pinning centers. A minimum occurs in three films, when
the field is applied perpendicular to the film plane. In the forth film,
instead, a local maximum caused by c-axis correlated pinning centers was found
at this orientation. The irradiation of two films with fast neutrons did not
change the properties drastically, where a maximum enhancement of the critical
current by a factor of two was found
A Novel Magnetoscan Setup
Due to a modification in the original magnetoscan setup, a significant
improvement in resolution was obtained. The paper focuses on experimental
results which should support the idea of the new setup using two magnets with
opposite direction of magnetization. This contribution to the characterization
techniques of melt-grown bulk superconductors should promote the easy
installation of this technique in industry. The improved magnetoscan technique
may further help to investigate growth-induced inhomogeneities of the
top-seeded-melt-growth process in the submillimeter range, and it offers new
possibilities to the characterization of smaller structures such as
superconducting films or coated conductors.Comment: 7 pages, 7 figure
New graduate nurse self-concept and retention : a longitudinal survey
Graduate nurse attrition is an increasing phenomenon within a world of decreasing nursing numbers. The newly developed nursing self-concept of the graduate nurse may provide a key indicator for predicting graduate retention. This study explores the development of multiple dimensions of nursing self-concept and examines their relationship to graduate nurse retention plans. A descriptive survey design with repeated measures was utilised to assess nurse self-concept and retention plans. The key findings suggest that multiple dimensions of graduate nurse self-concepts rise significantly in the second half of their graduate year and that nurse general self-concept is a strong predictor of graduate nurse retention. The implications of this study are that monitoring of self-concept throughout the transitional period for new nurses can lead to early detection and appropriate intervention strategies thereby improving retention rates for new nurses
Evaluation of tetracycline, erythromycin, penicillin and streptomycin for decontaminating koala semen contaminated in vitro with chlamydiae
Semen from seven koalas was extended in a tris-citrate glucose diluent containing one of four antibiotics at different concentrations and then contaminated with a standard concentration of chlamydiae. These semen preparations were then tested for residual chlamydial viability by an in vitro cell culture assay, and any detrimental effect of the antibiotics on the motility and viability of the sperm was assessed. Penicillin at 25 iu/ml or more, erythromycin at 1000 mug/ml or more and tetracycline at 200 mug/ml or more were highly effective at rendering the chlamydiae non-viable, but streptomycin showed no antichlamydial activity. There was a significant reduction of the motility of spermatozoa extended in diluents containing erythromycin (P < 0.05), but spermatozoa incubated with tetracycline up to concentrations of 200 mug/ml were not affected
Evaluation of tetracycline, erythromycin, penicillin and streptomycin for decontaminating koala semen contaminated in vitro with chlamydiae
Semen from seven koalas was extended in a tris-citrate glucose diluent containing one of four antibiotics at different concentrations and then contaminated with a standard concentration of chlamydiae. These semen preparations were then tested for residual chlamydial viability by an in vitro cell culture assay, and any detrimental effect of the antibiotics on the motility and viability of the sperm was assessed. Penicillin at 25 iu/ml or more, erythromycin at 1000 mug/ml or more and tetracycline at 200 mug/ml or more were highly effective at rendering the chlamydiae non-viable, but streptomycin showed no antichlamydial activity. There was a significant reduction of the motility of spermatozoa extended in diluents containing erythromycin (P < 0.05), but spermatozoa incubated with tetracycline up to concentrations of 200 mug/ml were not affected