Über Diffusion von Tanninlösungen in Gelatinegele

Ohne Zusammenfassung     

The diffraction of elastic waves by an imperfect fusion bond

We consider diffraction by a semi-infinite crack located alonga fusion interface between two differing elastic media. Twotypes of crack, namely open and partially closed cracks, areinvestigated. An open crack is modelled by a stress-free contactboundary condition and a partially closed crack is modelledby a spring contact boundary condition. For the latter, thejump in the stress across the crack is assumed to be proportionalto the jump in the displacement across the crack. This situationarises in, for example, a K-weld where the fine grain of theparent material (for example, ferritic or forged austeniticsteel) is in stark contrast with the coarse-grained weld metal(for example, austenitic weld metal). In the metal weld thedirection of the grain axis varies through the metal. However,diffraction is a local phenomenon and so the austenitic steelis assumed to have a zonal axis so that it may be modelled bya transversely isotropic composite. The ferritic or forged austeniticsteel will be modelled as an isotropic material.     

A simple spectrophotometric method for the determination of zirconium in U–Zr alloy samples in presence of fluoride ions

Journal of Radioanalytical and Nuclear Chemistry - A spectrophotometric method, circumventing interference from F− ions, during estimation of Zr in U-Zr alloy fuel, has been developed....     

ON AVOIDANCE ACTIVITIES IN FISHERY ENFORCEMENT MODELS

Compliance and enforcement in fisheries are important issues from an economic point of view since management measures are useless without a certain level of enforcement. These conclusions come from the well‐established theoretical literature on compliance and enforcement problems within fisheries and a common result is that, it is efficient to set fines as high as possible and monitoring as low as possible, when fines are costless and offenders are risk neutral. However, this result is sensitive to the assumption that fishermen cannot engage in avoidance activities, e.g., activities to reduce the likelihood of being detected when noncomplying. The paper presents a model of fisheries that allows the fishermen to engage in avoidance activities. The conclusions from the model are that, under certain circumstances, fines are costly transfers to society since they not only have a direct positive effect on the level of deterrence, but also an indirect negative effect in the form of increased avoidance activities to reduce the probability of detection. The paper contributes to the literature on avoidance activities by introducing the externality from the illegal behavior as an endogenous effect on other offenders. For an externality, that has an exogenous effect on other actors, Malik shows that fines are only costly transfers for conditional deterrence (when one actor is deterred while another actor is not). For fisheries, we show that fines are also costly transfers under no deterrence (when no agents are deterred).     

Synthesis of 1-Methyl-3-pyrrolin-2-one

The synthesis of 1-methyl-3-pyrrolin-2-one from the oxidative-elimination of 1-methyl-3-phenylselenenyl-2-pyrrolidinone and from the pyrolysis of 3-phenylsulfinyl-2-pyrrolidinone is reported.     

Photocatalytic patterning of monolayers for the site-selective deposition of quantum dots onto TiO2 surfaces

A novel photochemical mechanism is reported for the site-selective deposition of quantum dots onto nanocrystalline TiO2 films. The patterning mechanism involves the combination of surfactant-mediated self-assembly and monolayer photolithography. In the self-assembly process, CdS and CdSe quantum dots were attached to TiO2 surfaces through bifunctional mercaptoalkanoic acid (MAA) linkers. MAAs were adsorbed to the TiO2 surface as the deprotonated carboxylates, primarily through monodentate coordination to Ti4+ sites. CdSe quantum dots were bound to the terminal thiol groups of surface-adsorbed MAAs, with a surface adduct formation constant, Kad, of (2.1 +/- 0.7) x 104 M-1. The color and optical density of the quantum dot-functionalized TiO2 films were tunable. Monolayer photopatterning involved the TiO2-catalyzed oxidative degradation of surface-adsorbed mercaptohexadecanoic acid (MHDA). A mechanism is proposed wherein MHDA degradation occurs through both oxidative decarboxylation and the formation of interchain disulfides. These MHDA photodegradation processes regulate the extent to which CdSe quantum dots adsorb onto the TiO2 surface. Illumination through a photomask yielded optically patterned, quantum dot-functionalized TiO2 films that were characterized by scanning electron microscopy and energy-dispersive X-ray analysis.     

Discrimination between ginseng from Korea and China by light stable isotope analysis

Ginseng is a health food and traditional medicine highly valued in Asia. Ginseng from certain origins is higher valued than from other origins, so that a reliable method for differentiation of geographical origin is important for the economics of ginseng production. To discriminate between ginseng samples from South Korea and PR China, 29 samples have been analyzed for the isotopic composition of the elements H, C and N. The results showed δ(2)H values between -94 and -79‰, for δ(13)C -27.9 to -23.7‰ and for δ(15)N 1.3-5.4‰ for Chinese ginseng. Korean ginseng gave δ(2)H ratios between -91 and -69‰, δ(13)C ratios between -31.2 and -22.4‰ and δ(15)N ratios between -2.4 and +7‰. Despite the overlap between the values for individual isotopes, a combination of the isotope systems gave a reasonable differentiation between the two geographic origins. Especially the statistically significant difference in δ(2)H ratios facilitated the differentiation between Korean and Chinese ginseng samples.