Sökresultat

An experimental and theoretical study of the effect of flow maldistribution from port to channel on the thermal performance of single and multipass plate heat exchangers is presented. In general, flow maldistribution brings about an increase in pressure drop and decrease of the thermal performance in heat exchangers. This deterioration is found to depend on flow rate, number of channels, and port

The high-resolution infrared absorption spectrum for (HCN)(2) in the spectral region 3100-3300 cm(-1) is recorded in a static multipass cell at 240 K under equilibrium conditions. The spectrum shows extensive rovibrational structures which are due to the bound C-H stretching vibration band nu(2) of (HCN)(2) and several hot bands associated to nu(2). We manage to assign 63 new rovibrational transit

Hydrolysis of the straw material Paja Brava, a sturdy grass characteristic for the high plains of Bolivia, was studied in order to find suitable conditions for hydrolysis of the hemicellulose and cellulose parts. Dried Paja Brava material was pre-steamed, impregnated with dilute sulfuric acid (0.5% or 1.0% by wt), and subsequently hydrolyzed in a reactor at temperatures between 170 and 230 degrees

District heating is well expanded in the residential areas in Sweden, although not in detached house areas, where it is often impaired with problems of low heat density, large heat losses and high construction costs. However, due to the changes on the electricity market, increased environmental concerns and technological improvements, the detached houses’ sector is a potential market for district

The effects of continuous glial cell line-derived neurotrophic factor (GDNF) overexpression in the intact nigrostriatal dopamine (DA) system was studied using recombinant lentiviral (rLV) vector delivery of GDNF to the striatum or substantia nigra (SN) in the rat. Intrastriatal delivery of rLV-GDNF resulted in significant overexpression of GDNF in the striatum (2-4 ng/mg tissue) and anterograde tr

The electronic structure and the highest occupied molecular orbitals (HOMO)/the lowest unoccupied molecular orbitals (LUMO) alignment at the molecular semiconductor heterointerface of nanostructured TiO2/ZnPcGly dye sensitizer were characterized by X-ray and ultraviolet photoemission spectroscopy (XPS and UPS). The HOMO level of the dye ZnPcGly was determined to be located at 1.62 eV below the Fer

The present study was designed to evaluate the relative contribution of the different contractile P2 receptors in endothelium-denuded human coronary arteries by use of extracellular nucleotides, including the stable pyrimidines uridine 5'-O-3-thiotriphosphate (UTPgammaS) and uridine 5'-O-thiodiphosphate (UDPbetaS). The isometric tension of isolated vessel segments was recorded in vitro, and P2 rec

The atmospheric deposition of PCBs, DDT, and lindane, governed uptake in terrestrial biota in the Scandinavian penninsula. Mammalian herbivores and predators as well as predatory insects contained higher levels of pollutants at locations where the fallout load was high than at stations where atmospheric deposition was lower, and the two variables were significantly correlated.

The formation of triblock copolymer/surfactant complexes upon mixing a nonionic Pluronic polymer (PEO-PPO-PEO) with a cationic surfactant, hexadecyltrimethylammonium chloride (CTAC), has been studied in dilute aqueous solutions using small-angle X-ray scattering, static and dynamic light scattering, and self-diffusion NMR. The studied copolymer (denoted P123, EO20PO68EO20) forms micelles with a ra

A liquid-crystalline nanoparticles with internal reversed hexagonal structure has been prepared by use of a single lipid system. The obtained particles are essentially monocrystalline nanoporous hexagonal prisms with the size of about 200 nm.

The catalytic module of Hypocrea jecorina (previously Trichoderma reesei) Cel7B was homologously expressed by transformation of strain QM9414. Post-translational modifications in purified Cel7B preparations were analysed by enzymatic digestions, high performance chromatography, mass spectrometry and site-directed mutagenesis. Of the five potential sites found in the wild-type enzyme, only Asn56 an

We investigate the existence of positive solutions vanishing as x ->+infinity to the semilinear elliptic equation Delta u + f (x, u) + g(x)x . del u = 0, x > A > 0, in R-n, n >= 3, under mild assumptions on the functions f, g. Conditions for these solutions to be radial are also given.

Cells infected with herpes simplex virus type 1 (HSV-1) express a cell surface receptor able to bind the Fc portion of immunoglobulin G (IgG). Of the four human IgG subclasses, the HSV-1 Fc receptor, like staphylococcal protein A, binds to all except IgG3. In this paper, we describe the binding of a number of animal IgG and IgG subclass molecules to HSV-1-infected cells and compare this binding to

Observations of mercury lines in the HgMn stars chi Lupi and HR 7775 made with the Hubble Space Telescope Goddard High Resolution Spectrograph are presented and analyzed. In chi Lupi we find that all observed lines are consistent with the same isotopic mixture (essentially pure (204)Hg). Strong ionization anomalies are present, with UV Hg I lines being too weak and Hg III lines too strong for the

The aim of this study was to investigate why some people will and can work until they are 65 year or more, and some people not either can or will. The study was built at answers from 2 000 employees within the health and medical care services. The data material was divided into three groups from the answers. Group 1 who cannot and will not work until 65 years. Group 2 who can and will work until 6