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61.
As the climate changes, farmers in developing countries seek to employ strategies to help them sustain food production. The objectives of this paper were to identify adaptation strategies in response to climate change and the determinants for their adoption, and to explore the impact of these strategies on food security. The analysis was based on a survey of 900 small-scale farmers in a semi-arid (Dodoma) and a semi-humid (Morogoro) region in Tanzania. Farmers in the semi-humid region tended to diversify their crops, i.e. added additional crop types. Given the more challenging environment in the semi-arid region, farmers there changed their portfolio of crops, i.e. substituted some crops or cultivars with others. Logistic regressions highlighted higher tolerance to risk, land ownership, education and experiences of farmers as drivers of adoption, while income diversification had a negative effect. The propensity score matching approach showed that adopters of climate-smart strategies are on-average more food-secure. These users showed a more diverse pattern of food consumption, greater protein intake and better economic access to food. Changing crop portfolios can help households to cope with climate-related shocks such as droughts and thus appears to be the best performing strategy, especially in terms of more stable food provisioning throughout the year. 相似文献
62.
Andreas Haider Michael Reitberger Jürgen Leßlhumer Bernhard Plank Ulrich Müller 《Holz als Roh- und Werkstoff》2014,72(6):815-823
This article deals with the differences in the long-term durability and thermal stability under load of terrace deckings from various materials. The tested materials were deckings made of wood, thermally modified timber (TMT), and wood–polymer–composites (WPC). For the determination of the test temperatures for component testing according to EN 310, the surface temperatures of the decks during a normal hot summer day were measured. A cyclic test according to EN 321 was applied to all decking materials. Afterwards the component testing was repeated. All wooden samples reveal considerable cracks, some were twisted, and few were even broken. In particular regarding the optical appearance, wood decks show advantages against the TMT decks. Some WPC decks show very fine cracks on the face, which were additionally analyzed by means of X-ray computed tomography (CT). Except for the WPC deck with higher wood content, no WPC deck revealed significant changes after the cyclic test. The CT analysis was also suitable to find cracks inside the materials and illustrate them. Thus, the whole damage inside a sample could be characterized by calculating a kind of error pattern. No considerable cracks or failures could be observed on the WPC decks. 相似文献
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After it had been shown in a previous study that cements poor in alkali should be preferred when manufacturing wood-cement materials, this article outlines the investigations on the influence of wood (felling period, wood species, storage period) on the setting of cement. Detrimental impacts of the wood on the cement settings could be largely compensated by adding magnesium chloride or amorphous silicic acid (SiO2-fume). 相似文献
66.
Jewe Schröder Stefan KrausBruna Bertolla Rocha Volker GaukelHeike P. Schuchmann 《Journal of food engineering》2011,105(4):656-662
Effervescent atomization is a promising method for economical atomization of high viscous liquids like gelatinized corn starch suspensions. The gelatinization of starch has strong influence on the viscosity of starch suspensions. It was characterized adapting a method for determination of the gelatinization degree. Rheological properties of gelatinized corn starch suspensions with concentrations ranging from 5 to 7 wt.-% were investigated. Effervescent atomization proved to be largely invariant to variations of liquid viscosity in this range. Relative gas injection pressure proved to be of highest influence on the resulting drop size distribution when varying only atomizer geometry. Applying Abel inversion to drop size measurement results depicted the opposite trend of drop sizes depending on radial position in the spray than observed by other researchers working with aqueous glass bead suspensions. Compared to conventional external mixing pneumatic atomization a reduction of atomization gas quantity of up to four times could be achieved. 相似文献
67.
On-road measurement of particle emission in the exhaust plume of a diesel passenger car 总被引:1,自引:0,他引:1
Particle size distributions were measured under real world dilution conditions in the exhaust plume of a diesel passenger car closely followed by a mobile laboratory on a high speed test track. Under carefully controlled conditions the exhaust plume was continuously sampled and analyzed inside the mobile laboratory. Exhaust particle size distribution data were recorded together with exhaust gas concentrations, i.e., CO, CO2, and NO(x), and compared to data obtained from the same vehicle tested on a chassis dynamometer. Good agreement was found for the soot mode particles which occurred at a geometric mean diameter of approximately 50 nm and a total particle emission rate of 10(14) particles km(-1). Using 350 ppm high sulfur fuel and the standard oxidation catalyst a bimodal size distribution with a nucleation mode at 10 nm was observed at car velocities of 100 km h(-1) and 120 km h(-1), respectively. Nucleation mode particles were only present if high sulfur fuel was used with the oxidation catalyst installed. This is in agreement with prior work that these particles are of semivolatile nature and originate from the nucleation of sulfates formed inside the catalyst. Temporal effects of the occurrence of nucleation mode particles during steady-state cruising and the dynamical behavior during acceleration and deceleration were investigated. 相似文献
68.
Andreas Miller Eva Lassek Julia Pfister Richard Klinger Werner Höbel Holger Knapp Franziska Gaßmann Uwe Wollein Nicholas Schramek 《Journal für Verbraucherschutz und Lebensmittelsicherheit》2016,11(2):127-135
In the European Union, carminic acid and its ammonium, calcium, potassium or sodium salts and its aluminium lakes are approved as food additive E120. In beverages obtained from the German market 4-aminocarminic acid (“acid-stable carmine”) was detected by HPLC–PDA and LC–MS/MS. Isolation of the colorant from a liquid dye preparation used for the production of a beverage sample and subsequent NMR analysis confirmed the presence of 4-aminocarminic acid. Synthesis of 15N-4-aminocarminic acid clearly demonstrated that “acid-stable carmine” is not the ammonium salt of carminic acid, which is approved as food additive in the European Union. In fact, nitrogen in “acid-stable carmine” is covalently bound. The molecular structure of carminic acid is chemically modified and 4-aminocarminic acid does not comply with the specifications laid down for E120 in Commission Regulation (EU) No 231/2012. 4-Aminocarminic acid was also detected in the red-colored glaze of a raspberry cake and in the liquid dye preparation used for coloring this glaze. 相似文献
69.
The Reaction Product of Phenylalanin and Ninhydrin: Revision of Its Structure. Proton Transfer in an N-Unsubstituted, Highly Stabilized Azomethinylide The formerly proposed structures 6 and 7 for the intense colored reaction product of ninhydrin and phenylalanin are revised in favour of 5a , for which four other tautomeric forms 5b–5e have to be taken into account. Representing a highly stabilized N-unsubstituted azomethinylide 5a can be trapped with N-phenylmaleimide as dipolarophile; 1,3-dipolar cycloaddition and subsequent double bond shift leads to two diastereomeric products 15a and 15b . UV spectrometric data and dynamic 1H NMR measurements reveal an intramolecular proton transfer by hydrogen bonding between 5a and 5b dominating the tautomeric equilibrium. 相似文献
70.