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Bottom buoyancy layer in an ice‐covered lake

Field data on temperature and salt content structure in the vicinity of the bottom boundary in an ice‐covered lake are analyzed. A bottom boundary layer is identified, characterized by rapid increases in both temperature and salt concentration and having a thickness of ∼1 dm with respect to temperature and 2–4 cm with respect to salt content. A simple analytical model of the temperature distributi

Investigation of the spring thermal regime in Lake Ladoga using field and satellite data

We use a combination of field and satellite data to investigate the thermal regime in Lake Ladoga in spring 1992. The analysis concentrates mainly on the temperature structure in the convectively mixed region and the dynamics of a special thermo‐hydrodynamic phenomenon called “thermal bar” (a zone of descending water with the temperature of maximum density equal to ∼4°C). A theoretical model of th

Temperature distribution and current system in a convectively mixed lake

During spring and autumn, many lakes in temperate latitudes experience intensive convective mixing in the vertical, which leads to almost isothermal conditions with depth. Thus the regime of turbulence appears to be similar with that characteristic of convective boundary layers in the atmosphere. In the present paper a simple analytical approach, based on boundary-layer theory, is applied to conve

Field Investigation of the Thermal Bar in Lake Ladoga, Spring 1991

The thermal bar in Lake Ladoga was studied during one week in May 1991. Temperature and current velocity distributions were measured. The movement of the thermal bar and the horizontal heat transport were examined.The temperature off-shore the thermal bar was found to be constant within a vertical. The velocity distributions were complex and dependent on wind conditions. Calculations of changes in

Water surface temperature characteristics and thermal bar evolution during spring in Lake Ladoga

The present article is a study of the surface temperature distribution and its evolution during spring in Lake Ladoga, using NOAA-AVHRR Channel 4/Channel 5 (CH4/CH5) data, with special focus on a thermohydrodynamic phenomenon, called thermal bar. The split-window technique, where both constant and atmospheric-mass-dependent retrieval coefficients are tested, is used for calculating the atmospheric

Mapping the Pore Architecture of Structured Catalyst Monoliths from Nanometer to Centimeter Scale with Electron and X-ray Tomographies

The hierarchical pore systems of Pt/Al2O3 exhaust gas aftertreatment catalysts were analyzed with a collection of correlative imaging techniques to monitor changes induced by hydrothermal aging. Synergistic imaging with laboratory X-ray microtomography, synchrotron radiation ptychographic X-ray computed nanotomography, and electron tomography allowed quantitative observation of the catalyst pore a

Research protocol for mechanical complications after central venous catheterisation : a prospective controlled multicentre observational study to determine incidence and risk factors of mechanical complications within 24 hours after cannulation

INTRODUCTION: Central venous catheterisation is a common procedure in intensive care therapy and the use of central venous catheters is essential for treatment of many medical disorders. Although rare, central venous catheterisation is associated with mechanical complications that can be life-threatening if untreated. Real-time ultrasound guidance reduces the incidence of mechanical complications

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An update on charities in Dutch tax law.

Subcutaneous and intranasal administration of 1-deamino-8-d-arginine vasopressin in the assessment of renal concentration capacity

Maximum urine concentration capacity was studied in healthy adults using different routes and doses of administration of 1-deamino-8-d-arginine vasopressin (DDAVP) - desmopressin. Plasma levels of DDAVP showed a dose-dependent increase after the subcutaneous but not after the intranasal administration. The effect on urine osmolality was similar but more prolonged after the subcutaneous as compared