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51.
52.
Øyvind Borg Sølvi Storsæter Sigrid Eri Hanne Wigum Erling Rytter Anders Holmen 《Catalysis Letters》2006,107(1-2):95-102
The effect of water on the activity and selectivity for a series of γ-Al2O3 supported cobalt Fischer–Tropsch catalysts has been studied in an isothermal fixed-bed reactor at T = 483 K, P = 20 bar, and H2/CO = 2.1. The catalysts were produced applying incipient wetness impregnation and consisted of 20 wt.% cobalt and 0.5 wt.%
rhenium deposited on γ-Al2O3 supports with different pore characteristics. For the narrow-pore catalysts, addition of water corresponding to an inlet
partial pressure ratio of PH2O/PH2 = 0.4 reduced the reaction rates. In contrast, for a catalyst with larger pores the same water pressure increased the reaction
rates. For all catalysts, water amounts equal to PH2O/PH2 = 0.7 at the reactor inlet suppressed the reaction rates and led to permanent deactivation. The addition of water increased
the C5+ selectivity and decreased the CH4 selectivity for all catalysts. The pore characteristics seem to determine the effect of water on the rates. 相似文献
53.
Dr. Marta Robotta Hanne R. Gerding Antonia Vogel Prof. Dr. Karin Hauser Dr. Stefan Schildknecht Dr. Christiaan Karreman Dr. Marcel Leist Prof. Dr. Vinod Subramaniam Dr. Malte Drescher 《Chembiochem : a European journal of chemical biology》2014,15(17):2499-2502
The human alpha‐Synuclein (αS) protein is of significant interest because of its association with Parkinson's disease and related neurodegenerative disorders. The intrinsically disordered protein (140 amino acids) is characterized by the absence of a well‐defined structure in solution. It displays remarkable conformational flexibility upon macromolecular interactions, and can associate with mitochondrial membranes. Site‐directed spin‐labeling in combination with electron paramagnetic resonance spectroscopy enabled us to study the local binding properties of αS on artificial membranes (mimicking the inner and outer mitochondrial membranes), and to evaluate the importance of cardiolipin in this interaction. With pulsed, twofrequency, double‐electron electron paramagnetic resonance (DEER) approaches, we examined, to the best of our knowledge for the first time, the conformation of αS bound to isolated mitochondria. 相似文献
54.
We have compared the effects of three different margarines, one based on palm oil (PALM-margarine), one based on partially
hydrogenated soybean oil (TRANS-margarine) and one with a high content of polyunsaturated fatty acids (PUFA-margarine), on serum lipids in 27 young women.
The main purpose of the study was to test if replacement of trans fatty acids in margarine by palmitic acid results in unfavorable effects on serum lipids. The sum of saturated fatty acids
(12∶0, 14∶0, 16∶0) was 36.3% of total fatty acids in the PALM-diet, the same as the sum of saturated (12∶0, 14∶0, 16∶0) (12.5%)
and trans (23.1%) fatty acids in the TRANS-diet. This sum was 20.7% in the PUFA-diet. The content of oleic acid was 37.9, 35.2, and 38.6%, respectively, in the three
diets, whereas linoleic acid amounted to 16, 13.5, and 27.3%, respectively. Total fat provided 30–31% and the test margarines
26% of total energy in all three diets. The subjects consumed each of the diets for 17 d in a Latin-square crossover design.
There were no significant differences in total cholesterol, low density lipoprotein (LDL)-cholesterol and apolipoprotein B
(apoB) between the TRANS-and the PALM-diets. High density lipoprotein (HDL)-cholesterol and apoA-I were significantly higher on the PALM-diet compared
to the TRANS-diet whereas the ratio of LDL-cholesterol to HDL-cholesterol was lower, although not significantly (P=0.077) on the PALM-diet. Total cholesterol, LDL-cholesterol, and apoB were significantly lower on the PUFA-diet compared
to the two other diets. HDL-cholesterol was not different on the PALM-and the PUFA-diets but it was significantly lower on
the TRANS-diet compared to the PUFA diet. Compared to the PUFA-diet the ratio of LDL-to HDL-cholesterol was higher on both the PALM-
and the TRANS-diets whereas apoA-I was not different. Triglycerides and lipoprotein (a) were not significantly different among the three
diets. We concluded that nutritionally, palmitic acid from palm oil may be a reasonable alternative to trans fatty acids from partially hydrogenated soybean oil in margarine if the aim is to avoid trans fatty acids. A palm oil-based margarine is, however, less favorable than one based on a more polyunsaturated vegetable oil. 相似文献
55.
Hanne Van den Berghe W. Gheyle B. Stichelbaut T. Saey N. Note M. Van Meirvenne 《Landscape Research》2019,44(4):351-373
The First World War (WWI) had a notable influence on the landscape at the former Western Front in Belgium. Research on a landscape scale is necessary to understand the destructive and constructive impact of the war and its consequences for the post-war landscape in a holistic manner. This paper focuses on the trajectory and impact analysis of three study areas with contrasting landscape types and aims to indicate possible preserved military relics today. Therefore, landscape changes are studied using historical aerial photographs (WWI and WWII) and contemporary orthophotos. A military landscape characterisation is made based on land use/land cover and linear structures that were mapped throughout time. Specific landscape trajectories could be designated as areas with a possible preservation of WWI heritage, with a related impact degree. The results are useful for sustainable heritage management and for further interdisciplinary research on WWI-heritage, by providing a broad knowledge of the area. 相似文献
56.
Viscosity reduction of isotonic solutions of the photosensitizer TPCS2a by cyclodextrin complexation
Marianne Lilletvedt Tovsen Ingunn Tho Hanne Hjorth Tønnesen 《Drug development and industrial pharmacy》2018,44(2):261-265
Meso-tetraphenyl chlorin disulphonate (TPCS2a) is a photosensitizer (PS) particularly developed and patented for use in the technology of photochemical internalization (PCI) against cancer. TPCS2a is known to aggregate in aqueous media even at low concentrations (≥0.1?µM) and to form a high-viscosity network at clinically relevant concentrations (mM). The aim of this work was to evaluate the effect of two hydroxypropylated cyclodextrin derivatives of beta and gamma type, respectively i.e. HPβCD and HPγCD, on the aggregation and solubilization of TPCS2a in isotonic solutions. Samples containing micromolar concentrations of TPCS2a were studied spectrophotometrically, while samples containing a clinical relevant concentration (10?mM?=?9?mg/ml) of TPCS2a were evaluated by dynamic viscosity measurements. HPβCD was determined to be a more suitable solubilizer of TPCS2a than HPγCD in aqueous media both in the absence and presence of salt. The complexation stoichiometry between TPCS2a/HPβCD at micromolar to millimolar concentrations of TPCS2a was determined to be 1:3 and 1:2 in the absence and presence of isotonic NaCl, respectively. The network of TPCS2a (10?mM) was broken down in the presence of 3% w/v (=?20?mM) HPβCD, i.e. a 1:2 molar ratio between TPCS2a and the cyclodextrin. Formation of the inclusion complex resulted in low viscosity samples both in water and in the presence of isotonic NaCl or phosphate buffered saline (PBS) at 25?°C and 37?°C. 相似文献
57.
Hanne Larsen 《Packaging Technology and Science》2004,17(4):187-192
The ambient oxygen ingress rate (AOIR) method is an alternative or supplementary method to Ox‐Tran for measuring the oxygen transmission rate (OTR) of packages. The method has high capacity, requires relatively inexpensive equipment and measures OTR at different temperatures and humidity conditions. The aim of this study was, on the one hand, to study the effect of temperature on the OTR for packages produced from different polymer materials and laminates, and on the other hand to evaluate the suitability of the AOIR method at freezing temperature conditions. The OTR for 10 packages with different polymer compositions was measured at 23°C, 6°C and ?25°C. The AOIR method was shown to be a reliable test method for measuring OTR of packages at all the applied test conditions, also at frozen storage temperature. The OTR for the packages decreased with lower temperatures, especially for the packages with the highest OTR values at 23°C. In order to avoid higher packaging expenses than necessary to obtain the required shelf‐life for different food products, the OTR for alternative packages should be measured at the temperature and humidity conditions of intended use. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
58.
59.
B. J. Wigum W. J. French R. J. Howarth C. Hills 《Cement and Concrete Composites》1997,19(5-6):451-476
A number of tests are available for assessing the potential of aggregates for alkali-aggregate reaction. These are listed, for example, in ASTM C33-93. The majority of these test procedures have been widely used in researching aggregates, but there are serious reservations concerning the application of some of these tests to the selection of materials for structures. In recent years, many papers have been published detailing investigations of the tests. An examination of the literature shows that most of the tests are of little value for making engineering decisions. This paper reviews the literature relating to three commonly used tests, the ASTM C-289 Rapid Chemical Test, the ASTM C-227 Mortar Bar Test and what has become ASTM C-1260-94 Accelerated Mortar Bar Expansion Test. Attention has been given to a detailed practical study of the accelerated mortar bar tests since these are becoming very widely used. The experimental work, in essence, represents a determination of the errors to be expected from application of the test to a single aggregate and the factors that influence these errors. The repeatability of the tests suggests an upper bound standard deviation of 0.0365% expansion. This figure is used to establish discriminant criteria for the recognition of potentially damaging materials. It is evident that diagnosis of potentially highly reactive materials can be made with confidence, but that a large number of tests are required to assess marginal types. Petrographic evaluation of the mortar following the test is essential, particularly where the results are borderline, though the presence of traces of gel has to be interpreted with caution. Much of the uncertainty in the test results derives from inherent aggregate variability. A test schedule can be designed that has small contributions to the error from the experimental steps, but the error due to aggregate variability remains. This can lead to the requirement for the manufacture of multiple batches of mortar for establishing acceptance criteria for even a single aggregate batch, and further consideration is needed as to the procedures necessary for the assessment of aggregate sources. 相似文献
60.
Erik Svanes Mie Vold Hanne Møller Marit Kvalvåg Pettersen Hanne Larsen Ole Jørgen Hanssen 《Packaging Technology and Science》2010,23(3):161-175
This study describes a holistic methodology for sustainable packaging design. This methodology studies the combined systems of packaging and the packaged products across the whole distribution chain from manufacturer to end consumer and the life cycle from raw material extraction to the waste phase. It contains a number of indicators that are grouped into the following main categories: environmental sustainability, distribution costs, product protection, market acceptance and user friendliness. The methodology integrates a number of different analytical methods. It is intended to be used in packaging design and optimisation, for idea generation, decision support and as documentation of properties of existing packaging systems. The study describes experiences with the methodology from one case study in the Norwegian Food Industry. The experiences show that the methodology is very comprehensive, and gives a good overview of the properties of a packaging solution. It enables quantitative comparisons between different packaging solutions throughout the design process. The methodology reduces the risk of implementing sub‐optimal packaging solutions. An additional benefit of the methodology is gained by working in cross‐functional teams. One potential drawback is that the methodology can be resource and data intensive. The methodology can be used as a tool box in packaging design, i.e. it is not necessary to use all methods and quantify all indicators to gain benefit. However, all indicators and requirements should be evaluated and considered. In all cases, it should be considered to include additional indicators if important sustainability issues have not been addressed. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献