Morphology and agglomeration control of LiMnPO4_4 micro- and nanocrystals

Microwave-assisted hydrothermal synthesis was used to grow LiMnPO$_4$ micro- and nanocrystals from acetate precursors. By appropriate adjustment of the precursor concentration and the pH-value of the reactant, the product composition and purity along with the crystal size can be manipulated, resulting in particle-dimensions from around 10 mm down to a few 100 nm. Prisms and plates with hexagonal basal face as well as cuboid and rod-like particles were produced. The effects on the crystal morphology as well as on the materials texture and agglomeration tendency are discussed and a comprehensive agglomeration phase diagram is constructed

Vergleichende Eislagerung von ausgenommenen und unausgenommenen Schleien

New regulations of the German “Fisch-Hygiene-Verordnung” lay down that all fish except pelagic species have to be gutted immediately after catch or killing, especially fresh water fish from aquaculture. Only gutted fish should be sold to the consumer. At the present time, however, it is not unusual to sell ungutted fish like tropical or mediterranean species from foreign countries, even the EC area. In this investigation the influence of gutting on the fish quality during storage on ice was tested in tench (Tinca tinca) as a model. Quality changes were controlled by sensory, chemical, physical and microbiological assessment. It was shown that for tench there were no differences between gutted and ungutted fish during 12 days of storage on ice

Qualitätsvergleich zwischen maschinen- und handgeschälten Nordseegarnelen

After the evaluation of 48 samples consisting of hand and machine-peeled sand shrimps it can be stated that there was no significant difference in quality between both. The quality of the sand shrimps was evaluated by sensorially performed paired comparison as well as by estimating the microbial load and the volatile amines (MMA, DMA, TMA). Additionally, the colour characteristics were measured instrumentally. To characterise the influence of the technological regime measurements of pH and of the salt content were performed. The quality of sand shrimp is further influenced by technological steps as freezing, cooking procedure and preservatives used. From the hygienic point of view the machine-peeling was without any objections. The microbial load was small and below the limit set by EC. Measurement of volatile amines was not suited to make visible difference created be the various peeling methods

Der Einsatz von Flüssigrauch: eine neue Technologie Teil 3: Untersuchungen zur Lagerfähigkeit von mit Flüssigrauch hergestellten vakuumverpackten Räucherfischprodukten

The investigations showed that the shelf life of traditional smoked and vacuum-packed gutted mackerels, mackerel and herring fillets is similar to the corresponding vacuum-packed products smoked with liquid smoke. The storage temperature was 5 ± 0,5 °C. Under experimental conditions the storage time was 26 days for smoked gutted mackerels and more than 30 days for smoked fillets. Storage times of 20 to 25 days for these products are recommended. The microbiological and chemical results showed no differences between both technologies

Baxter`s inequality and sieve bootstrap for random fields

The concept of the autoregressive (AR) sieve bootstrap is investigated for the case of spatial processes in Z2. This procedure fits AR models of increasing order to the given data and, via resampling of the residuals, generates bootstrap replicates of the sample. The paper explores the range of validity of this resampling procedure and provides a general check criterion which allows to decide whether the AR sieve bootstrap asymptotically works for a specific statistic of interest or not. The criterion may be applied to a large class of stationary spatial processes. As another major contribution of this paper, a weighted Baxter-inequality for spatial processes is provided. This result yields a rate of convergence for the finite predictor coefficients, i.e. the coefficients of finite-order AR model fits, towards the autoregressive coefficients which are inherent to the underlying process under mild conditions. The developed check criterion is applied to some particularly interesting statistics like sample autocorrelations and standardized sample variograms. A simulation study shows that the procedure performs very well compared to normal approximations as well as block bootstrap methods in finite samples

Determination of secondary ion mass spectrometry relative sensitivity factors for polar and non-polar ZnO

Zinc oxide (ZnO) is regarded as a promising material for optoelectronic devices, due to its electronic properties. Solely, the difficulty in obtaining p-type ZnO impedes further progress. In this connection, the identification and quantification of impurities is a major demand. For quantitative information using secondary ion mass spectrometry (SIMS), so-called relative sensitivity factors (RSF) are mandatory. Such conversion factors did not yet exist for ZnO. In this work, we present the determined RSF values for ZnO using primary (ion implanted) as well as secondary (bulk doped) standards. These RSFs have been applied to commercially available ZnO substrates of different surface termination (a-plane, Zn-face, and O-face) to quantify the contained impurities. Although these ZnO substrates originate from the same single-crystal, we observe discrepancies in the impurity concentrations. These results cannot be attributed to surface termination dependent RSF values for ZnO

Small vs large dust grains in transitional disks: do different cavity sizes indicate a planet?

Transitional disks represent a short stage of the evolution of circumstellar material. Studies of dust grains in these objects can provide pivotal information on the mechanisms of planet formation. Dissimilarities in the spatial distribution of small (micron-size) and large (millimeter-size) dust grains have recently been pointed out. Constraints on the small dust grains can be obtained by imaging the distribution of scattered light at near-infrared wavelengths. We aim at resolving structures in the surface layer of transitional disks (with particular emphasis on the inner 10 - 50 AU), thus increasing the scarce sample of high resolution images of these objects. We obtained VLT/NACO near-IR high-resolution polarimetric differential imaging observations of SAO 206462 (HD135344B). This technique allows one to image the polarized scattered light from the disk without any occulting mask and to reach an inner working angle of 0.1''. A face-on disk is detected in H and Ks bands between 0.1'' and 0.9''. No significant differences are seen between the H and Ks images. In addition to the spiral arms, these new data allow us to resolve for the first time an inner cavity for small dust grains. The cavity size (about 28 AU) is much smaller than what is inferred for large dust grains from (sub)mm observations (39 to 50 AU). The interaction between the disk and potential orbiting companion(s) can explain both the spiral arm structure and the discrepant cavity sizes for small and large dust grains. One planet may be carving out the gas (and, thus, the small grains) at 28 AU, and generating a pressure bump at larger radii (39 AU), which holds back the large grains. We analytically estimate that, in this scenario, a single giant planet (with a mass between 5 and 15 Jupiter masses) at 17 to 20 AU from the star is consistent with the observed cavity sizes.Comment: 11 pages, 6 figures; accepted for publication in A&

Artificial neural network (ANN) velocity better identifies benign prostatic hyperplasia but not prostate cancer compared with PSA velocity

Abstract Background To validate an artificial neural network (ANN) based on the combination of PSA velocity (PSAV) with a %free PSA-based ANN to enhance the discrimination between prostate cancer (PCa) and benign prostate hyperplasia (BPH). Methods The study comprised 199 patients with PCa (n = 49) or BPH (n = 150) with at least three PSA estimations and a minimum of three months intervals between the measurements. Patients were classified into three categories according to PSAV and ANN velocity (ANNV) calculated with the %free based ANN "ProstataClass". Group 1 includes the increasing PSA and ANN values, Group 2 the stable values, and Group 3 the decreasing values. Results 71% of PCa patients typically have an increasing PSAV. In comparison, the ANNV only shows this in 45% of all PCa patients. However, BPH patients benefit from ANNV since the stable values are significantly more (83% vs. 65%) and increasing values are less frequently (11% vs. 21%) if the ANNV is used instead of the PSAV. Conclusion PSAV has only limited usefulness for the detection of PCa with only 71% increasing PSA values, while 29% of all PCa do not have the typical PSAV. The ANNV cannot improve the PCa detection rate but may save 11–17% of unnecessary prostate biopsies in known BPH patients.</p