Testing for cycles in multiple time series

In practice, it is often impossible to assess the validity of the smoothness assumptions crucial to standard tests for singularities in the spectrum. We therefore propose new tests which are completely insensitive to sharp peaks in the absolutely continuous part of the spectrum. Using Neyman Pearson tests of Bayesian mixtures we first derive admissible tests under simplifying assumptions and then show that under realistic assumptions our test statistics remain the same. The tests are designed to have high power especially against alternatives containing oscillations which are positively correlated with each other. Motivated by a biological dataset with non‐sinusoidal oscillations, we finally extend our approach by including higher harmonics.     

Charge storage performance of polyetherimide Ultem®1000—Influence of secondary antioxidants and purification

The performance of a polymeric electret material depends on many parameters, and besides chemical structure, charging conditions, and application temperature, other factors, such as grade, manufacturer, processing history, and additive package, are critical. Commercial polyetherimide (PEI) Ultem®1000 films exhibited satisfying electret properties as revealed by an isothermal potential decay (ITPD) to 75% of the initial surface charge after 24 h at 90°C. It was found that after purification by reprecipitation this value drops to 34% and that the same PEI synthesized by two different methods revealed to be a very poor electret with charge retention of almost zero. Assuming that an additive in the commercial material might be responsible for this behavior, we identified an organophosphonite which is commonly used as antioxidant in high‐temperature polymers. We incorporated this additive by melt compounding into purified PEI and found a dramatic increase in charge retention to 79% of the initial charge at an additive load level of 0.5 wt %. By immersing Ultem®1000 films in water, the electret behavior was further improved and almost 100% charge retention was achieved. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Analysis of purine compounds and creatinine by ion-pair high-performance liquid chromatography (HPLC) as a method for the detection of yeast extracts in commercial meat flavourings

The purine patterns of five industrially produced yeast extracts and nine yeast-extract-based commercial meat flavourings were analysed by ion-pair HPLC after acid hydrolysis of the purine-containing compounds and a clean-up step via cation exchange. The results indicate that there is a good correlation between the adenine contents of the flavourings and the yeast extract percentages used for their manufacture. The possible addition of authentic meat constituents (e.g. meat extract) would contribute likewise to the adenine contents of commercial meat flavourings. To recognize those products the characteristic meat constituent creatinine was analysed simultanously.

---

Nachweis von Hefeextrakt in handelsüblichen Fleischessenzen durch Bestimmung der Purinverbindungen und des Kreatininsmittels der Ionenpaar-Hochleistungsflüssigchromatographie (HPLC)

Zusammenfassung Mittels Ionenpaar-HPLC wurden die Purinmuster von 5 industriell hergestellten Hefeextrakten sowie von 9 handelsüblichen, auf Basis von Hefeextrakt hergestellten Fleischessenzen untersucht. Die Probenaufarbeitung umfaßte eine Hydrolyse der purinhaltigen Verbindungen und einen Aufreinigungsschritt mittels Kationenaustausch. Die Ergebnisse zeigen, daß eine gute Korrelation zwischen den Adeningehalten handelsüblicher Fleischessenzen und den zu deren Herstellung verwendeten Hefeextraktanteilen besteht. Der mögliche Zusatz von authentischen Fleischauszügen (z.B. Fleischextrakt) würde ebenfalls zum Adeningehalt handelsüblicher Fleischessenzen beitragen. Um derartige Produkte zu erkennen, wurde die vorgestellte Methode so konzipiert, daß der charakteristische Fleischinhaltsstoff Kreatinin simultan miterfaßt wird.

     

模块化机器的安全白皮书

SmartFactory~(KL)工作组1 智能基础设施专门处理模块化工业4.0生产设施的安全问题。其旨在提供一种工厂结构,通过模块化等手段确保其灵活性和可变性。本安型模块具有常规的功能安全性。但是,模块间依然存在依赖关系。在支持未知模块的模块化系统中,还需要一个新的安全体系结构。去年,该概念被整合到了工业4.0生产设施中,以实例证明该概念可在当今技术的基础上得以实施。在安全和机器通信的实施中,仅采用了一条单线共存。机器和机器模块可以在运行期间插入生产线或从生产线移除,而不会影响工厂的其它部分。必要的安全相关参数将根据此处导入的安全配置文件自动进行协商、配置和发布。要求如下文所述。     

Effects of chromium poisoning on the long-term oxygen exchange kinetics of the solid oxide fuel cell cathode materials La0.6Sr0.4CoO3 and Nd2NiO4

The influence of chromium poisoning on the long-term stability of the oxygen exchange kinetics of the promising IT-SOFC cathode materials La_0.6Sr_0.4CoO_3−δ (LSC) and Nd₂NiO_4+δ (NDN) is investigated in-situ by dc-conductivity relaxation experiments. The as-prepared LSC and NDN samples show high chemical oxygen surface exchange coefficients k_chem. After the deposition of a 10 nm thick Cr-layer onto the surface, k_chem of LSC decreases to 50% of the initial value. Additional chromium deposition of 20 nm on LSC leads to a further decrease of k_chem to 27% of the initial value. In contrast, the effect of a 10 nm thick Cr-layer on k_chem of NDN is negligible. Even with additional 20 nm of chromium and a total testing time of 1750 h, the nickelate retains a k_chem of 60% of the initial value. X-ray photoelectron spectroscopy (XPS) of the degraded. LSC shows a significantly altered surface cation composition with Sr-enrichment down to 30 nm depth while XPS analysis of the degraded NDN reveals a thin surface zone of approximately 30 nm containing nickel and chromium. In contrast to LSC, the changes in the surface composition of NDN due to Cr-poisoning ultimately had only a minor influence on the surface exchange properties.     

The effect of dual atmosphere conditions on the corrosion of Sandvik Sanergy HT

Sandvik Sanergy HT is considered as an interconnect material for PCFC and SOFC. In this work corrosion of Sandvik Sanergy HT was studied under simulated fuel cell conditions in a dual atmosphere setup, with air on one side and hydrogen on the other. Both the microstructure and the composition of the oxide scales grown in air were significantly altered by dual atmosphere. The Fe concentration in the oxides increased; the highest Fe concentration was found in oxides formed in air with dry 5% H₂ + Ar on the other side of the sample. The effects of dual atmosphere conditions became more pronounced by increasing the duration and the reaction temperature. Variations in the oxidation behavior are discussed in the view of hydrogen transport through the interconnect material, and its influence on the outward metal transport and oxide scale growth.     

Towards tough, yet stiff, composites by filling an elastomer with single-walled nanotubes at very high loading levels

We have used recent advances in nanotube dispersion technology to prepare composites based on polyurethane, with mass fractions of up to 80% polyethylene glycol functionalized nanotubes. Mechanical testing shows increases in Young's modulus compared to polyurethane films by up to 800 ×. While the composite strength did not vary significantly with nanotube content, the ductility and so the toughness fell by a factor of 240 × on addition of ～40?wt% nanotubes. Depending on the nanotube content we can produce films ranging from the stiff and brittle at high nanotube loading to the compliant and ductile at low nanotube volume fraction.     

Bioaccumulation of pharmaceuticals and other anthropogenic waste indicators in earthworms from agricultural soil amended with biosolid or swine manure

Analysis of earthworms offers potential for assessing the transfer of organic anthropogenic waste indicators (AWIs) derived from land-applied biosolid or manure to biota. Earthworms and soil samples were collected from three Midwest agricultural fields to measure the presence and potential for transfer of 77 AWIs from land-applied biosolids and livestock manure to earthworms. The sites consisted of a soybean field with no amendments of human or livestock waste (Site 1), a soybean field amended with biosolids from a municipal wastewater treatment plant (Site 2), and a cornfield amended with swine manure (Site 3). The biosolid applied to Site 2 contained a diverse composition of 28 AWls, reflecting the presence of human-use compounds. The swine manure contained 12 AWls, and was dominated by biogenic sterols. Soil and earthworm samples were collected in the spring (about30 days after soil amendment) and fall (140-155 days after soil amendment) at all field sites. Soils from Site 1 contained 21 AWIs and soil from Sites 2 and 3 contained 19 AWls. The AWI profiles at Sites 2 and 3 generally reflected the relative composition of AWls present in waste material applied. There were 20 AWls detected in earthworms from Site 1 (three compounds exceeding concentrations of 1000 microg/kg), 25 AWls in earthworms from Site 2 (seven compounds exceeding concentrations of 1000 microg/ kg), and 21 AWls in earthworms from Site 3 (five compounds exceeding concentrations of 1000 microg/kg). A number of compounds thatwere present in the earthworm tissue were at concentrations less than reporting levels in the corresponding soil samples. The AWIs detected in earthworm tissue from the three field sites included pharmaceuticals, synthetic fragrances, detergent metabolites, polycyclic aromatic hydrocarbons (PAHs), biogenic sterols, disinfectants, and pesticides, reflecting a wide range of physicochemical properties. For those contaminants detected in earthworm tissue and soil, bioaccumulation factors (BAF) ranged from 0.05 (galaxolide) to 27 (triclosan). This study documents that when AWls are present in source materials that are land applied, such as biosolids and swine manure, AWls can be transferred to earthworms.