Blackberry leaf extract: a multifunctional anti-aging active

Matrix metalloproteinases (MMPs) play a major role in wrinkle formation. Their expression increases with aging and is further enhanced by UV irradiation. Blackberry ( Rubus fruticosus ) leaf extract has been shown to suppress MMP-1, -2 and -9 in cell-free assays. We have now further explored the activity of this extract. The effect on MMP-1 expression at the protein and the mRNA level was investigated using non-irradiated and UVA-irradiated human dermal fibroblasts. The extract showed a dose-dependent reduction of the MMP-1 protein level of both irradiated and non-irradiated cells with an almost complete inhibition at a dosage of 0.1%. MMP-1 mRNA expression of UVA-irradiated cells was decreased after pre-incubation as well as after post-incubation with the extract. Best results were obtained with combined pre- and post-treatment (0.1% extract led to 59% reduction in comparison with the respective control). Moreover, we found that blackberry leaf extract inhibits IL-1α, a cytokine known to induce MMP expression. At a dosage of 0.2% the inhibition was 40% compared with that of the stimulated control. The extract also exhibited a potent radical scavenging activity comparable to that of α-tocopherol as was shown by the ABTS assay. Taken together, these biological activities make blackberry leaf extract a highly efficient multifunctional anti-aging active.     

Design of Packaging Vents for Cooling Fresh Horticultural Produce

This review focuses on the design of vents in packages used for handling horticulture produce. The studies on vent designs that are conducted to obtain fundamental understanding of the mechanisms by which different parameters affect the rate and homogeneity of the airflow and the cooling process are presented. Ventilated packages should be designed in such a way that they can provide a uniform airflow distribution and consequently uniform produce cooling. Total opening area and opening size and position show a significant effect on pressure drop, air distribution uniformity and cooling efficiency. Recent advances in measurement and mathematical modelling techniques have provided powerful tools to develop detailed investigations of local airflow rate and heat and mass transfer processes within complex packaging structures. The complexity of the physical structure of the packed systems and the biological variability of the produce make both experimental and model-based studies of transport processes challenging. In many of the available mathematical models, the packed structure is assumed as a porous medium; the limitations of the porous media approach are evident during vented package design studies principally when the container-to-produce dimension ratio is below a certain value. The complex and chaotic structure within horticultural produce ventilated packages during a forced-air precooling process complicates the numerical study of energy and mass transfer considering each individual produce. Future research efforts should be directed to detailed models of the vented package, the complex produce stacking within the package, as well as their interaction with adjacent produce, stacks and surrounding environment. For the validation of the numerical models, the development of better experimental techniques taking into account the complex packaging system is also very important.     

中德两国大型区域供热系统的结构性差异与启示

从热源、调峰锅炉加输配站、输送管网、楼栋换热站、室内供暖系统等环节介绍了德国海德堡市的大型区域供热系统。经分析、比较中德两国的供热系统,发现德国的区域供热系统具有以下特点:1)清洁环保、高效供热;2)热用户可以自主选择高标准舒适供暖和全年使用集中生活热水;3)其高效输配系统既可节省初投资,又能降低水系统输配能耗,还巧妙地解决了管网的水力平衡问题;4)优良的调节性能使其供热系统既能适应天气的变化,又能有效地适应用户调节引起的流量变化,供热企业主要通过变流量调节实现供热系统节能;5)整体的经济技术保证措施使得热计量行为节能目标得到彻底落实;6)严格精细的保温规定为减少热输送过程中的热损失提供了可靠保证。     

Determination of iodine species in milk using ion chromatographic separation and ICP-MS detection

A combination of ion chromatography (IC) and inductively coupled plasma-mass spectrometry (ICP-MS) was used to determine iodine species in Thuringian milk samples. The developed method allows the fast and sensitive determination of iodine species with limits of determination for iodide and iodate <2 µg/L. Iodide was identified as the main iodine species in milk, but in a few samples also traces of iodate and several unidentified, presumably organoiodine compounds were observed as well. In addition, the total iodine concentration in the samples was determined by ICP-MS and gives an idea about the actual iodine state in Thuringian milk.     

Modellversuche und numerische Simulationen mit der Diskrete‐Elemente‐Methode zum räumlichen passiven Erddruck

Model tests and numerical simulations with the Distinct‐Element‐Method to spatial passive earth pressure. The growing urban development in connection with a closer approach of excavations to existing buildings requires a more careful dimensioning of the excavation walls which specially refers to the movement of retaining walls. For more realistic investigations own model experiments were planned, made and analysed. New testing and measuring methods were developed which for the first time made it possible to record stress distributions along girders. The Distinct‐Element‐Method (DEM) was extended and improved to enable the numerical simulation of load tests. This method allows to describe the experiments with an adequate accuracy. Based on this knowledge, conditions not covered by experiments could be simulated by means of the DEM. Accordingly, the test matrix could be extended.     

Erhöhung der Verschleißfestigkeit der TiAl6V4-Legierung durch Implantieren mit Stickstoff-Ionen

Increasing of wear resistance of Ti-6Al-4V alloy by nitrogen implantation Nitrogen ion implantation is used to improve the wear resistance of Ti-6Al-4V alloy. Different implantation doses up to 1 · 10¹⁸N⁺/cm² and E = 170 KeV were used. The unimplanted and the implanted specimens were tested in a wear model system with oscillation loading. The results show, that the wear performance was influenced by implantation dose and also by mean pressure. It was found, that surfaces, which are produced by a high implantation dose (1 · 10¹⁸N⁺/cm²), exhibited greater were resistance than untreated Ti-6Al-4V alloy. The best wear behaviour was achieved by a high implantation dose (1 · 10¹⁸N⁺/cm²) and a low mean pressure (p =0.22 MPa) at the wear test. The difference between the wear rate of the untreated and of the implantated specimen can obtain a factor about 10. The effective depth of the implantation action is greater than the penetration depth of the nitrogen ions.     

Microencapsulation of fish oil by freeze-drying techniques and influence of process parameters on oxidative stability during storage

Dried microencapsulated fish oils (DMFO) were obtained by freeze-drying and the influence of various process parameters on oxidative stability was evaluated. Standard emulsions were composed of sandeel oil, sodium caseinate and lactose, homogenised by three passes at 40 MPa, frozen at −40°C, kept at −30°C and freeze-dried. In selected trials, carbohydrate, homogenisation pressure, freezing rate and initial temperature for freeze-drying were varied. DMFOs were stored at 25°C in the dark and oxidation monitored through anisidine values and polymer levels. Results showed no apparent relationships between oil globule size or microencapsulation efficiency and storage stability, and the only trial with significantly longer shelf-life involved fast-freezing in liquid nitrogen. Received: 24 November 1999     

Multicrystalline Silicon for Solar Cells: Process Development by Numerical Simulation

Continuously improving crystallization conditions and solar cell processes have lead to steadily increasing efficiencies of solar cells based on multicrystalline silicon. There is, however, still an efficiency gap between mono‐ and multicrystalline silicon amounting to 1–2 % (absolute) depending on the cell process used. Topographies of the local solar cell performance clearly reveal that the main contribution to this efficiency gap is due to recombination‐active dislocations present in multicrystalline silicon. A further improvement of the efficiencies attainable with multicrystalline solar cells therefore is achievable by a reduction of the dislocation density. Dislocations originate from thermal stress that originates from temperature gradients inside a multicrystalline ingot during crystallization and cooling. In order to reduce this thermal stress and consequently the dislocation density we employ a numerical simulation routine, the so‐called virtual crystallization furnace, for perfect control of the temperature distribution during the entire ingot fabrication process.     

Imaging-sonar observations of salmonid interactions with a vertical axis instream turbine

Anthropogenic activities and their influences on aquatic systems is an important topic, especially considering the growing interest in using the earth's resources in a sustainable way. One of those anthropogenic activities is the introduction of renewable technologies into the aquatic environment such as instream turbines. Environmental studies around those technologies are often still ongoing due to their novelty. During the spring of 2018, juvenile individuals of two salmonid species, Atlantic salmon and brown trout were released upstream a vertical axis instream turbine in the river Dal (Dalälven) in eastern Sweden. The aim of this study was to investigate the swimming behavior of the salmonids around a small-scale prototype vertical axis instream turbine. The swimming pattern and the possible response of avoiding the vertical axis instream turbine were documented with a multi beam sonar. A control area, next to the turbine, was used as reference. No consistent results were shown for trout as they were passing the control area with a statistically high variation, and specimens were rarely observed in proximity of the turbine, neither if the turbine was operating nor at stand still. Salmon clearly avoided the operating turbine, but did not avoid the turbine when it was at stand still, and was often observed swimming straight through the turbine area. These findings indicate that operating this type of instream turbine in a river affects the swimming behavior of Atlantic salmon but is unlikely to affect its migration paths. For brown trout, the statistical results are inconclusive, although data indicate a response of avoiding the turbine. The species are in little risk to suffer physical harm as no fish entered the rotating turbine, despite very turbid water conditions.