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5-(2-Aminopropyl)benzofuran (5-APB) and 6-(2-aminopropyl)benzofuran (6-APB) are benzofuran analogues of amphetamine and belong to the category of new psychoactive substances. Despite already published fatal 5- and 6-APB intoxication after consumption of both substances in most cases, no sensitive method for the simultaneous detection and quantification of these new psychoactive compounds in human blood samples has yet been developed. Therefore, an easy and fast sample preparation and specific high-performance liquid chromatography and tandem mass spectrometry methods for the determination of both substances in blood were established and validated. In a fatal intoxication in 2017 at the Institute of Forensic and Traffic Medicine in Heidelberg, Germany, concentrations of 850 (5-APB) and 300 ng/mL (6-APB) were determined in peripheral blood. Besides, other body fluids (central blood, urine and bile), hair and various tissues were examined to verify the presence of both compounds and to gain first insights into their distribution. In this publication, we show a method for the simultaneous determination of 5- and 6-APB in human samples by a chromatographic method and to investigate their distribution in the human body.

The serotonin transporter (5-HTT) is a key molecule of serotoninergic neurotransmission and target of many anxiolytics and antidepressants. In humans, 5-HTT gene variants resulting in lower expression levels are associated with behavioral traits of anxiety. Furthermore, functional magnetic resonance imaging (fMRI) studies reported increased cerebral blood flow (CBF) during resting state (RS) and amygdala hyperreactivity. 5-HTT deficient mice as an established animal model for anxiety disorders seem to be well suited for investigating amygdala (re-)activity in an fMRI study. We investigated wildtype (5-HTT+/+), heterozygous (5-HTT+/-), and homozygous 5-HTT-knockout mice (5-HTT-/-) of both sexes in an ultra-high-field 17.6 Tesla magnetic resonance scanner. CBF was measured with continuous arterial spin labeling during RS, stimulation state (SS; with odor of rats as aversive stimulus), and post-stimulation state (PS). Subsequently, post mortem c-Fos immunohistochemistry elucidated neural activation on cellular level. The results showed that in reaction to the aversive odor CBF in total brain and amygdala of all mice significantly increased. In male 5-HTT+/+ mice amygdala RS CBF levels were found to be significantly lower than in 5-HTT+/- mice. From RS to SS 5-HTT+/+ amygdala perfusion significantly increased compared to both 5-HTT+/- and 5-HTT-/- mice. Perfusion level changes of male mice correlated with the density of c-Fos-immunoreactive cells in the amygdaloid nuclei. In female mice the perfusion was not modulated by the 5-Htt-genotype, but by estrous cycle stages. We conclude that amygdala reactivity is modulated by the 5-Htt genotype in males. In females, gonadal hormones have an impact which might have obscured genotype effects. Furthermore, our results demonstrate experimental support for the tonic model of 5-HTTLPR function.

In aquatic ecosystems, anthropogenic activities disrupt nutrient fluxes, thereby promoting harmful algal blooms that could directly impact economies and human health. Within this framework, the forecasting of the proxy of chlorophyll a in coastal areas is the first step to managing these algal blooms. The primary goal was to analyze how phytoplankton bloom forecasts are impacted by different sampling frequencies, by using a machine learning model. The database used in this study was sourced from an automated system located in the English Channel. This device has a sampling frequency of 20 min. We considered 12 physicochemical parameters over a six-year period. Our forecast methodology is based on the random forest (RF) model and a sliding window strategy. The lag times for these sliding windows ranged from 12 h to 3 months with four different sampling times until 1 day. The results indicate that the optimal forecast was obtained for a 20 min time step, with an average R2 of 0.62. Moreover, the highest values of fluorescence were predicted when the water temperature was approximately 11.8 °C. Consequently, we demonstrated that the sampling frequency directly impacts the forecast performance of an RF model. Furthermore, this kind of model can recreate interactions that closely resemble biological processes. Our study suggests that the RF model can utilize the additional information contained in high-frequency datasets. The methodology presented here lays the foundation for the development of a numerical decision-making tool that could help mitigate the impact of these algal blooms.

We developed a simple transient Chinese Hamster Ovary expression platform. Titers for a random panel of 20 clinical monoclonal antibodies (mAbs) ranged from 0.6 to 2.7 g/L after 7 days. Two factors were the key in obtaining these high titers. First, we utilized an extremely high starting cell density (20 million cells/ml), and then arrested further cell growth by employing mild hypothermic conditions (32°C). Second, we performed a 6-variable Design of Experiments to find optimal concentrations of plasmid DNA (coding DNA), boost DNA (DNA encoding the XBP1S transcription factor), transfection reagent (polyethylenimine [PEI]), and nutrient feed amounts. High coding DNA concentrations (12.5 mg/L) were found to be optimal. We therefore diluted expensive coding DNA with inexpensive inert filler DNA (herring sperm DNA). Reducing the coding DNA concentration by 70% from 12.5 to 3.75 mg/L did not meaningfully reduce mAb titers. Titers for the same panel of 20 clinical mAbs ranged from 0.7 to 2.2 g/L after reducing the coding DNA concentration to 3.75 mg/L. Finally, we found that titer and product quality attributes were similar for a clinical mAb (rituximab) expressed at very different scales (volumes ranging from 3 ml to 2 L).

International audience; Automated pulse shape-recording flow cytometry was applied to address phytoplankton spatial distribution, at high frequency, in stratified and well mixed water masses in the Western and Central English Channel during the summer-fall transition. Cytometric pulse shapes derived from optical features of single cells allowed the characterization of eight phytoplankton groups. Abundance and total red fluorescence (chlorophyll a autofluorescence) per group were used to define six phytoplankton communities. Their distribution revealed high spatial heterogeneity. Abundance presented a longitudinal gradient for six over the eight groups and succession of brutal shifts along the cruise. Maximum values were often located near the Ushant front in the Western English Channel. A latitudinal gradient characterised the Central English Channel waters under the influence of the Seine estuary. Picophytoplankton (Synechococcus-like cells and picoeukaryotes) represented up to 96% of total abundance and half of the total red fluorescence of the communities near the main front and the Bay of Seine, whereas nanoeukaryotes and microphytoplankton, represented only 4% and less than 1% respectively of total abundance. Both nanoeukaryotes and microphytoplankton dominated the total red fluorescence of the communities of the Central English Channel. The study of traits within each group showed a high variability of traits between communities. The comparison between traits showed that they were independent from each other for some groups (size and red fluorescence per cell for PicoHighFLR and Coccolithophore-like cells; orange and red fluorescence for all the groups), whereas they were dependent for other groups (red fluorescence per cell was dependent of size for picophytoplankton, NanoLowFLR, NanoHighFLR, Cryptophyte-like cells and Microphytoplankton). Variance partitioning revealed that the environmental parameters (temperature, salinity and turbidity) accounted less than spatial descriptors (physical and biological processes) in shaping the communities. Hydrological structures (frontal structures, eddies and tidal streams) were responsible for patches of phytoplankton and defined the structure at the sub-mesoscale (1–10 km) in this area.

Most biopharmaceutical drugs, especially monoclonal antibodies (mAbs), bispecific antibodies (BsAbs) and Fc-fusion proteins, are expressed using Chinese Hamster Ovary (CHO) cell lines. CHO cells typically yield high product titers and high product quality. Unfortunately, CHO cell lines also generate high molecular weight (HMW) aggregates of the desired product during cell culture along with CHO host cell protein (HCP) and CHO DNA. These immunogenic species, co-purified during Protein A purification, must be removed in a multi-step purification process. Our colleagues have reported the use of a novel polymer-mediated flocculation step to simultaneously reduce HMW, HCP and DNA from stable CHO cell cultures prior to Protein A purification. The objective of this study was to evaluate this novel "smart polymer" (SmP) in a high throughput antibody discovery workflow using transiently transfected CHO cultures. SmP treatment of 19 different molecules from four distinct molecular categories (human mAbs, murine mAbs, BsAbs and Fabs) with 0.1% SmP and 25 mM stimulus resulted in minimal loss of monomeric protein. Treatment with SmP also demonstrated a variable, concentration-dependent removal of HMW aggregates after Protein A purification. SmP treatment also effectively reduced HCP levels at each step of mAb purification with final HCP levels being several fold lower than the untreated control. Interestingly, SmP treatment was able to significantly reduce high concentrations of artificially spiked levels of endotoxin in the cultures. In summary, adding a simple flocculation step to our existing transient CHO process reduced the downstream purification burden to remove impurities and improved final product quality. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1393-1400, 2017.

We evaluate the effect of chain length for a series of alkyl sulfonic acid additives on Cu electrodeposition by using a combination of electrochemical and Raman spectroscopic methods. Rotating disk linear sweep voltammetry revealed the influence of these additives on the bulk concentration of Cu+ and on the exchange current densities of the reduction of Cu2+/Cu+ and Cu+/Cu. We then used in situ shell-isolated, nanoparticle-enhanced Raman spectroscopy to correlate the additives’ effects on deposition kinetics with their chemical structures at the electrode surface. The combination of these methods suggests that effective Cu electrodeposition acceleration processes require: (1) direct tethering of mercaptoalkylsulfonate species to the electrode, (2) partial desolvation of Cu2+ by the sulfonate group to minimize its solvent reorganization energy, and (3) stabilization of Cu+ adjacent to the electrode surface by addition of halide. The model provides support for recently proposed theories for the electrodeposition of metals where charge is carried across the electrode interface by the cation, rather than the electron.

We investigate the mechanism of 3-mercapto-1-propanesulfonate (MPS) acceleration of Cu electrodeposition in the presence of Cl– through comparison with the inactive but related model compounds 1-butanesulfonate and 1-butanethiol (BuSH). In situ shell-isolated nanoparticle-enhanced Raman spectroscopy was used to evaluate these additives as a function of potential. MPS adsorbs to the Cu electrode in the presence of Cl– through the thiol functional group. Density functional theory calculations reveal that the adsorption of thiol has a depolarizing effect on the strength of the interaction between adsorbed Cl– and the electrode surface, the consequences of which are observed spectroscopically. The sulfonate moiety does not interact directly with the electrode. However, cyclic voltammetry used to assess the permeability of adsorbed MPS and BuSH adlayers indicates that the sulfonate group has a more direct role in Cu deposition beyond simple disruption of the surface layer.

Generating purified protein for GLP toxicology studies (GLP-Tox) represents an important and often rate limiting step in the biopharmaceutical drug development process. Toxicity testing requires large amounts of therapeutic protein (>100 g), typically produced in a single 500-2,500 L bioreactor, using the final CHO clonally derived cell line (CDCL). One approach currently used to save time is to manufacture GLP-Tox material using pools of high-producing CHO CDCLs instead of waiting for the final CDCL. Recently, we reported CHO pools producing mAb titers >7 g/L using piggyBac-mediated gene integration (PB CHO pools). In this study, we wanted to leverage high titer PB CHO pools to produce GLP-Tox material. A detailed product quality attribute (PQA) assessment was conducted comparing PB CHO pools to pooled Top4 CDCLs. Four mAbs were evaluated. First, we found that PB CHO pools expressed all four mAbs at high titers (2.8-4.4 g/L in shake flasks). Second, all four PB CHO pools were aged to 55 generations (Gen). All four PB CHO Pools were found to be suitable over 55 Gen. Finally, we performed bioreactor scale-up. PB CHO pool titers (3.7-4.8 g/L) were similar or higher than the pooled Top 4 CDCLs in 5 L bioreactors (2.4-4.1 g/L). The PQAs of protein derived from PB CHO pools were very similar to pooled Top 4 CHO CDCLs according to multiple orthogonal techniques including peptide mapping analysis. Taken together, these results demonstrate the technical feasibility of using PB CHO pools to manufacture protein for GLP-Tox. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 33:1436-1448, 2017.

The influence of 3,5-diamino-1,2,4-triazole (DAT) on the electrochemical reduction of carbon dioxide to carbon monoxide on a silver electrode was studied via in situ surface-enhanced Raman spectroscopy (SERS). SERS bands obtained in the absence of DAT indicate potential-dependent adsorption of the CO product to bridge and 3-fold hollow sites. With the addition of DAT, CO adsorption to less-coordinated surface sites was found, including a physisorbed or noncoordinating site that exhibited no significant Stark vibrational shift. Raman peaks associated with adsorbed DAT observed at the same potentials as this species suggest that the ligand promotes weaker CO adsorption, which may be responsible for the high efficiency of the AgDAT catalyst. The observation of potential-dependent methylene stretching vibrations indicates the presence of surface hydrocarbon species while the presence of C–D stretches in deuterated electrolyte confirm that these hydrocarbons are generated as a CO2 reduction byproduct.

International audience; Polymer Electrolyte Fuel Cells operating in alkaline media present various advantages. As an alternative to fossil origin polymer electrolytes, the synthesis of crosslinked anion exchange membranes based on cellulose is described in this paper. Using cellulose p-toluenesulfonate derivatives, a carbohydrate polymer bearing quaternary ammonium moieties is synthesized by a reaction with 1,4-diazabicyclo[2.2.2]octane. Membranes are then obtained by crosslinking this cationic polymer with diiodobutane. IR and NMR spectroscopy together with elemental analysis confirmed structures of the different intermediates. In order to complete this study, Ionic Exchange Capacity, Water Uptake and conductimetry data are also provided.

The local wall shear stress (WSS) mapping in the rotating cage (RC) has been obtained from measuring the diffusion current due to the electrochemical reduction of methyl viologen used as tracer system for both Newtonian and non-Newtonian solutions. The latter were achieved with oleyltrimethyl ammonium, a cationic surfactant, and sodium salicylate as counter-ion, forming thread-like micelles which induce drag reduction conditions. The maximum WSS values were detected in the middle of the coupon in agreement with observation of corroded coupons in erosion–corrosion tests. Maximum values of 65% for drag reduction were measured at the same locations.

We consider here, the fluctuations of turbidity, oxygen and pH time series recorded from the MAREL system (Ifremer, France), which is based on the deployment of data buoys equipped with water analysis capabilities in an automated mode. We perform a spectral analysis (from 10 min to years) of these time series, and we estimate their probability density functions. Oxygen, turbidity and pH are important quantities for ecosystem studies and physics–biology couplings, and their fluctuations reveal the possible influence of environmental factors such as tides and turbulence. Turbidity variability is highly complex and does not appear to be directly coupled to turbulence, since no clear range is visible. On the other hand, oxygen percentage of saturation and pH data show remarkably nice scaling ranges, indicating an important coupling with turbulence, but also biological or chemical activity, since the statistics differ markedly from passive scalars. Several possible sources of this variability are discussed.

International audience; The temporal variability in phytoplankton photosynthetic activity was studied in the coastal waters of the Strait of Dover and related to environmental conditions. Phytoplankton photosynthetic activity data collected from October 2008 and August 2010 at different time scales (hourly to interannual) using a nested sampling design are presented. Photosynthetic parameters including the maximum quantum yield (Fv/Fm), maximal light utilization efficiency (α), maximum electron transport rate (ETRm) and light saturation coefficient (Ek) were measured using Pulse Amplitude Modulation (PAM) fluorometry. Information on the taxonomic composition of phytoplankton assemblages and physicochemical parameters were also collected. Marked changes in photosynthetic parameters were observed at the different time scales investigated. The variability of photosynthetic parameters at sub-seasonal scale (hourly to monthly) could be of the same order of magnitude as at seasonal scale. At short time scale (hour to week), there was no consistent pattern of diel periodicity in photosynthetic parameters. There was a decline of ETRm and α during the day as often as there was a peak at the maximum of irradiance. Light conditions were the main influencing factor on photosynthetic parameters at these time scales. The optimal use of incident irradiance seemed focused on between-day rather than within-day variability. At longer time scale (seasonal to interannual), close interplays between shifts in community taxonomic composition and changes in the physicochemical characteristics of the environment controlled the variability in photosynthetic parameters. Whatever the time scale and period of year considered, variability in photosynthetic parameters was ;Ek-independent;. In well-mixed macrotidal ecosystems, such as the Strait of Dover, a nested sampling design allowing to characterize the short- (intraday and daily) as well as long-term variability (within months, monthly, seasonal, annual and interannual) in photosynthetic parameters is required to get a suitable picture of phytoplankton photosynthesis and avoid potential problems of aliasing.

The potential of single-sided Nuclear Magnetic Resonance (NMR) to monitor truly non-invasive changes in polymer materials during aging under aggressive media is for the first time evaluated. For this, the NMR method is used in combination with other condition monitoring methods including mechanical measurements, mass uptake, and differential scanning calorimetry. It is validated by studying for the first time the aging kinetics of silane cross-linked polyethylene (PEX) exposed to media used in oil and gas production and transportation, including aliphatic and aromatic hydrocarbons, sulphur solvents, and corrosion inhibitors in combination with CO2 and H2S. All investigated parameters changed, with the strongest effects detected for the NMR chain mobility and in the presence of hydrocarbons. Furthermore, a universal linear correlation curve could be established between the depression of the tensile strength and the chain mobility. This result represents a fundamental step towards establishing single-sided NMR as a new analytical tool for in situ condition monitoring of polyethylene working under sour conditions. The proposed approach can be easily extended to other polymer materials.

Hydrogenation processes leading from biomolecules to fossil biomarkers in anoxic sediments are crucial for the preservation of organic matter. However, these processes are still poorly understood. The present identification of several reduced carotenoids in recent sediments attests that these processes operate at the earliest stages of diagenesis without structural or stereochemical specificity, implying a nonbiological reduction pathway. Sulfur species (e.g., H 2 S) are the hydrogen donors involved in such reduction, as demonstrated with laboratory experiments. These reactions allow the preservation of abundant organic carbon in the rock record.

Recent in situ measurements at tropical tropopause temperatures as low as 187 K indicate supersaturations with respect to ice exceeding 100% with little or no ice present. In contrast, models used to simulate cloud formation near the tropopause assume a supersaturation threshold for ice nucleation of about 65% based on laboratory measurements of aqueous aerosol freezing. The high supersaturations reported here, along with cloud simulations assuming a plausible range of temperature histories in the sampled air mass, indicate that the vast majority of aerosols in the air sampled on this flight must have had supersaturation thresholds for ice nucleation exceeding 100% (i.e. near liquid water saturation at these temperatures). Possible explanations for this high threshold are that (1) the expressions used for calculating vapor pressure over supercooled water at low temperatures give values are at least 20% too low, (2) organic films on the aerosol surfaces reduce their accommodation coefficient for uptake of water, resulting in aerosols with more concentrated solutions when moderate-rapid cooling occurs and correspondingly inhibited homogeneous freezing, and (3) if surface freezing dominates, organic coatings may increase the surface energy of the ice embryo/vapor interface resulting in suppressed ice nucleation. Simulations of in situ cloud formation in the tropical tropopause layer (TTL) throughout the tropics indicate that if decreased accommodation coefficients and resulting high thresholds for ice nucleation prevailed throughout the tropics, then the calculated occurrence frequency and areal coverage of TTL cirrus would be significantly suppressed. However, the simulations also show that even if in situ TTL cirrus form only over a very small fraction of the tropics in the western Pacific, enough air passes through them due to rapid horizontal transport such that they can still effectively freeze-dry air entering the stratosphere. The TTL cirrus simulations show that even if very large supersaturations are required for ice nucleation, these large supersaturations should occur very rarely.

Corrosion is the reaction of a material with its environment which causes a measurable change at the material and can lead to an impairment of the function of a component or a whole system. This definition which for the first time was formulated in DIN 50900, Part 1 (1975) is valid for all materials, also for organic macromolecular materials (polymers, plastics, etc.). Here, the observable manifestations of corrosion can be structured basically in a similar way as the types of metallic corrosion if only the chemical and physical nature of the mechanisms are considered. In this paper this is proposed for the first time. Contributions to the understanding of the corrosion of organic materials can hardly be expected from the electrochemist, but rather by chemists or physicists or broadly oriented corrosionists with a good physico-chemical background. A wide field of research calls for interdisciplinary and innovative treatment.

The Ge island growth on the Si(100) and Si(111) surfaces was investigated through spectral ellipsometry in real time. It is found that both cases correspond to Stranski-Krastanov growth; i.e., a Ge wetting layer is initially formed, and only then do the islands of the new phase grow on the surface of this layer. However, the island nucleation on the (100) surface is accompanied by a substantial decrease in the wetting layer thickness, whereas, on the (111) surface, the islands nucleate and grow on the wetting layer of constant thickness. The Ge atoms on the (100) surface transfer from the wetting layer to islands, thus substantially decreasing the elastic energy of the system, but increasing the surface energy. For this reason, it is concluded that, in this case, it is the elastic energy which represents the fundamental driving force of the island nucleation. Thermodynamic and kinetic theories of island nucleation from the wetting layer under the effect of elastic energy are developed. A new notion of overstress is introduced by analogy with supersaturation and overcooling. The time evolution of the wetting layer thickness, the nucleation rate, and the island surface density of the new phase is described. The theoretical results are compared to experimental data obtained through ellipsometric simulation, and it is found that the theory and experiment are in good agreement.

The inhibition efficiency of a series of organic compounds against corrosion of magnesium alloy AZ91 in a 50 wt.-% aqueous solutions of ethylene glycol has been studied using polarisation curves and electrochemical noise (ECN) measurements. The comparative analysis of the results obtained has demonstrated unambiguously that the method of ECN is an effective tool for screening of new corrosion inhibitors which offers some advantages comparing to the common electrochemical techniques. The very fast measuring rate enables to instantaneously register and monitor the rate of the corrosion process and changes in its mechanism in presence of the organic additives. The measurements are performed at freely corroding identical electrodes without perturbation from the external signals, which could lead (as in the polarisation measurements), to changes in the surface structure, the adsorption of the inhibitor etc. The statistical analysis of the noise data (in terms of standard deviations) in the time domain shows that the noise intensity of the system correlates well with the intensity of the corrosion process. The total amount of the charges exchanged during the tests is a quantitative measure for the inhibiting effect of the substances under study, while the spectral analysis of the noise in the frequency domain can be used to characterise the type of the corrosion attack.

Low pressure chemical vapor deposition (LPCVD) of germanium crystallites on silicon surfaces from a digermane precursor has been studied in situ and in real time by spectroscopic ellipsometry (SE) in the range 1.2–4.7 eV and ex situ by scanning force microscopy (SFM). As substrates, hydrogen-terminated silicon surfaces were employed. A two-layer model consisting of a pure germanium layer and a layer of germanium islands, was used to simulate the ellipsometric data. To treat the wetting and island layer a Bruggemann effective medium approximation (EMA) of germanium and voids was used. The time evolution of the wetting layer and the island layer, could be described independently by the model, resulting in separate growth rates for each layer. The onset and end of nucleation could be determined with high-time resolution. To our knowledge, this is the first report on the evaluation of real-time ellipsometric data to model Stranski–Krastanow (SK) growth of germanium on a silicon surface. Measurements of the topography by SFM showed a smooth surface between germanium islands at the end of the deposition process. The amount of Ge contained in the islands is in good agreement with a theoretical growth model.

In order to determine the driving force of coherent island nucleation and growth, the formation of Ge islands on H-terminated Si(100) surfaces has been investigated by spectroscopic ellipsometry in real time. The process of island nucleation is found to be accompanied by a strong reduction of the wetting layer thickness. The results indicate that, in this case, islands are nucleated mainly due to the relaxation of the stress energy in the wetting layer. Thermodynamic and kinetic models have been developed for this process. It is shown that the free energy of stress-driven formation of islands contains a saddle point. The value of free energy at this point determines the nucleation process. The time evolution of the thickness of the wetting layer is described and the time dependencies of the nucleation rate and surface density of islands are calculated. Good agreement between this theory and real-time ellipsometric analysis of the growth process is found.

World-largest super floating macroalgal blooms of Ulva prolifera have lasted 7 years by now in every summer in the Yellow Sea, the outer part of a semi-enclosed coastal sea. Evaluation of the inter-annual variability in the trophic status is one of fundamental tasks for prediction and management of the blooms. We show the new findings of a progressive eutrophication in the large Yellow Sea basin behind the super floating macroalgal blooms. The inter-annual variability in human-induced nutrient pollution from 2001 to 2012 was assessed by a nutrient pollution index weighted by area (AWCPI-NP), and a significant increase in the trophic status was found in the macroalgal bloom (MAB) phase (2007–2012): the average AWCPI-NP was higher than that in the pre-MAB phase (2001–2006) by about 45%; meanwhile, in the Jiangsu Shoal, origin place of the drifting macroaglae, the annual in-situ nutrient concentrations increased rapidly from 2000 to 2011. Chlorophyll a concentration (Chl a), an indicator of eutrophication, increased by about 15% in the bloom region from the pre-MAB to MAB phase. This progressive eutrophication might lead to the non-linear outburst in the growth of macroalgae, i.e., green tides, in the Yellow Sea since 2007.

Electrochemical noise analysis was succesfully applied to study anion effects in the first 20 h starting period of copper corrosion in tap water. The influence of chloride, sulfate and bicarbonate as single anions and the interactions between them in three anion solutions were characterized in terms of standard deviation and PSD(I) data as well as interaction coefficients obtained from the evaluation of a set of experiments designed according to a statistical 23-factorial plan. The results let conclude that sulfate has an activating and chloride a passivating effect. Bicarbonate seems to act as a buffering agent. It is obviously the combination of the presence of all three anions in a narrow range of concentration ratios which finally leads to pitting corrosion. The relevance of these results from short term exposure for the long term performance of copper in tap water and the likelihood of pitting corrosion should now be investigated in long term exposure tests. Elektrochemische Rauschmessungen an Kupfer in kunstlichem Trinkwasser – Untersuchung von Anionen-Effekten Die elektrochemische Rauschanalyse wurde erfolgreich zum Studium von Anioneneffekten in den ersten 20 h der Korrosion von Kupfer in Trinkwasser eingesetzt. Der Einflus von Chlorid, Sulfat und Bikarbonat als Einzelionen und deren Wechselwirkung untereinander wurden als Standardabweichungen und PSD(I)-Steigungen und uber Wechselwirkungskoeffizienten charakterisiert, welche durch Auswertung von Experimenten aus einem 23-Faktorenplan berechnet wurden. Aus den Resultaten geht hervor, das Sulfat einen aktivierenden und Chlorid einen passivierenden Einflus besitzt. Bikarbonat scheint als Puffersubstanz wirksam zu werden. Es ist offensichtlich die Kombination aus der Anwesenheit aller drei Anionen in einem engen Bereich von Konzentrationsverhaltnissen, welche letztlich zur Lochkorrosion fuhrt. Die Relevanz dieser Resultate aus Kurzzeitversuchen fur das Langzeitverhalten von Kupfer in Trinkwasser und die Lochkorrosionswahrscheinlichkeit sollte nunmehr durch Langzeitauslagerungsversuche uberpruft werden.

Drag reduction, i.e. the influence of additives in the ppm-range on the reduction of skin friction caused by turbulent flowing liquids, results from interaction of macromolecules and higher molecular micellar aggregates of amphipathic molecules with near-wall turbulence elements. Drag reducing properties exhibited by corrosion inhibitors above critical concentrations decide on the level of critical wall shear stresses for initiation of flow induced localized corrosion (FILC). The relevance of drag reduction on FILC inhibition is explained with the newly developed probabilistic model of FILC initiation. The impinging jet method is recommended to quantify the effect of inhibitors on critical wall shear stresses by corrosion experiments and on drag reduction by electrochemically controlled mass transport measurements. Experimental evidence is given for FILC inhibition in CO2 and H2S corrosion systems. Drag reduction by corrosion inhibitors includes the interaction of shear-induced molecular aggregate structures in near-wall turbulences with adsorbates on the solid surface. Wandreibungsverminderung durch Korrosionsinhibitoren – Eine vernachlassigte Option zur Bekampfung von stromungsinduzierter Lokalkorrosion Wandreibungsverminderung, d.h. der Einfluss von Additiven im ppm-Bereich auf die Verminderung der Wandschubspannung durch turbulent stromende Flussigkeiten, resultiert aus der Wechselwirkung von Makromolekulen bzw. hohermolekularen mizellaren Aggregaten amphipathischer Molekule mit wandnahen Turbulenzelementen. Die wandschubspannungsvermindernden Eigenschaften, welche Korrosionsinhibitoren oberhalb kritischer Konzentrationen besitzen, entscheiden uber das Niveau kritischer Wandschubspannungen fur die Initiierung stromungsinduzierter Lokalkorrosion (SILK). Die Relevanz der Wandreibungsverminderung fur die SILK-Inhibition wird durch ein neues, probabilistisches Modell der SILK -Initiierung erklart. Es wird empfohlen, den Einfluss von Inhibitoren auf kritische Wandschubspannungen durch Korrosionsexperimente unter den Bedingungen der getauchten Dusenstromung und auf die Wandreibungsverminderung durch elektrochemische Messungen unter Massentransportkontrolle zu quantifizieren. Experimentelle Beispiele werden fur den Fall der SILK-Inhibierung in CO2 und H2S-Korrosionssystemen gegeben. Die Wandreibungsverminderung von Korrosionsinhibitoren schliest eine Wechselwirkung scherinduzierter molekularer Aggregate-Strukturen in wandnahen Turbulenzen mit Adsorbaten auf der Feststoffoberflache ein.

Under corrosion promoting conditions which were introduced by local heat treatment of copper tubes simulating hard soldering and 8 weeks horizontal half-filled pre-exposure of the tubes, the initial phase of copper corrosion was studied in Bocholt tap water in a once-flow-through rig under consumer relevant flow conditions. Pitting corrosion (l max : 80 μm in 32 weeks) was observed only in characteristic areas of the heat treated zone and preferentially in surfaces which had been in water contact during half-filled pre-exposure. Tubes without half-filled pre-exposure showed no localized attack. The effect of heat treatment on scale morphology and composition was studied by SEM/EDX.

We measured the concentrations of Cl^−, NO_3^−, and SO_4^(2−) in atmospheric cloudwater collected with a passive collector from a remote marine site and the concentrations of Cl^−, NO_3^−, SO_4^(2−), Na^+ and NH_4^+ in cloudwater from a continental site. At the continental site, an active rotating arm collector was employed for cloudwater collection. At both locations, we observed an inverse relationship between the measured ion concentrations and the liquid water content of the clouds. The product of the observed concentrations and the liquid water content, the cloudwater loading, was found to be nearly constant. A study of published cloudwater data showed that at the majority of the examined locations this product varied little at any given site, whereas large differences exist between sites. The finding of the small variation in cloudwater loadings could be explained by the hypothesis that nucleation scavenging is the dominant process in the acquisition of solutes into hydro-meteors during fog and cloud formation.

The field of application for electronic assemblies expands continuously. Especially in automotive and telecommunication systems the use of electronic assemblies increases. At the same time the increasing numbers of electronic functions and the decreasing of the pin distance leads to smaller and smaller dimensions under extreme environmental conditions - especially variations in temperature and humidity. By using electrochemical analysis methods such as free corrosion potential and current-density potential curves which until today have only been used sporadically as test procedures in electronics and, if at all, only in relation to the final result of individual measurements, it is in fact possible to estimate reliability already in advance. This enable us to assess new material/flux combinations in a selection procedure, and thus to further reduce development times and costs. This is of particular importance in view of the prohibition of lead-containing soldering materials, since there are hardly any findings about the proneness of substitute combinations to subsequent migration and corrosion.

T he use of holographic materials is increasing at a dramatic rate in research and consumeruse systems. A recent report estimated that the worldwide holographic market for 1998 was as high as $2.8 billion.1 While static holograms are by far the most widely used, many applications would bene® t greatly by being able to turn the holograms off and on like an optical switch. This article describes the development of holographically recorded liquid crystal/polymer composites known as holographic polymer-dispersed liquid cr ystals (HPDLCs). H-PDLCs are prepared by causing inter ference between two coherent laser beams in a photosensitive monomer/liquid crystal (LC) mixture contained between two sub

In order to improve the engine output and the efficiency of gas turbines, optimized thermal barrier coatings (TBCs) are required to protect the metallic components at high temperatures. In common TBC-systems, consisting of a Ni-base alloy substrate/MCrAlY-bond coat/ZrO 2 7 wt.% Y 2 O 3 top coat, an oxide layer grows at the interface bond coat/ceramic under high temperature service, which limits the life of these coatings. In this paper the oxidation resistance of a new triplex TBC-system, consisting of a CoNiCrAlY-bond coat/Pt-modified aluminide coating/ZrO 2 7 wt.% Y 2 O 3 top coat is compared with that of a common TBC-system. The as-coated Pt-aluminide coating consists of an outer region of PtAl 2 +(CoNiPt)Al followed by a single phase layer of (CoNiPt)Al. The results of the oxidation tests at 1000, 1050 and 1100°C in air show excellent oxidation resistance of the triplex TBC-system with the thickest investigated Pt-aluminide coating. In particular, a 28 μm thick Pt-aluminide coating allows the thickness of the oxide layers to be reduced up to 70% compared to the common TBC after 500 h at all examined temperatures. After heat treatment the coating systems were investigated by SEM, EDX and X-ray analysis. Annealing tests with Al 2 O 3 powder indicate which mechanism is probably responsible for the improved oxidation resistance of platinum additions. Platinum is evidently capable of decomposing aluminum oxide at temperatures above 900°C.

A rapid and sensitive determination procedure using liquid chromatography–electrospray ionization mass spectrometry (LC–ESI-MS) has been developed for the determination of ethyl glucuronide (EtG) in human serum. Samples were precipitated with methanol, centrifuged and the supernatant was evaporated to dryness followed by reconstitution with distilled water. As mobile phase 30 m M ammonium acetate–acetonitrile (30:70, v/v) was utilized. The base peak observed at m/z 221 was the [M−H] − ion of EtG, which was detectable in satisfactory sense. The detection limit was 0.03 μg/ml in the selected ion monitoring mode. A calibration graph constructed for EtG in serum gave good linearity over the range from 0.1 to 25 μg/ml. This paper also presents the application of this LC–ESI-MS procedure to the analysis of authentic serum samples.

The mechanical properties, microstructure morphology and failure behavior of hybrid fiber reinforced thermoplastic composites containing defects were studied for a coupled thermal and mechanical loading. The system investigated was a hybrid short-fiber composite of poly (aryl ether ketone) reinforced with 30wt% of aluminum fibers and 10wt% of carbon fibers. Fracture tests of specimens with different artificial defects, including notches and crack-like slots, subjected to thermal and mechanical loading, were carried out by using three-point short-beam bending tests. The effects of changing temperature on the mechanical strength of the composite are then discussed in detail, and the failure modes and corresponding morphology of broken samples are systematically characterized by SEM. Finally, the macroscopic and microscopic failure behavior and corresponding morphology of the composite under coupled thermal and applied loads were characterised on the basis of the experimental data. Results show that the effect of changing temperature greatly affects the macroscopic fracture mode, microscopic failure behavior, and rupture morphology of the composite along with its mechanical properties.

To develop highly efficient gas turbines, thermal barrier coating systems with a high reliability and a long lifetime under severe operating conditions are required. The failure of TBC-systems is caused by thermal cycling conditions, oxidation attack, and insufficient adhesion at the interfaced the ceramic coating and the bond coat. Coating failure occurs mostly near the interface top coat-bond coat. Two modifications of a conventional duplex TBC-system consisting of a Ni-base alloy substrate/MCrAlY-bond coat/ZrO2 7 wt.% Y2O3-top coat, which is used as the reference system, are presented as follows. (i) By contouring the MCrAlY-bond coat with a laser, the stress distribution at the ZrO2-bond coat interface can be modified by forming folds, within the laminate structure of the ceramic top coat and increasing the bonding area. TBC-systems containing a contoured bond coat show better thermal cycling behaviour. FEM-simulation of thermally induced stress shows an alternating stress distribution which is caused by the contoured bond coat interface, (ii) High-velocity oxygen fuel (HVOF)-sprayed MCrAlY layers are a new possibility to create homogeneous bond coats. Thermal barrier coatings with LPPS-(low pressure plasma sprayed) or HVOF-CoNiCrAlY bond coats are compared by investigating their porosity, roughness, and oxidation behaviour. The porosity is proportional to the roughness of the HVOF bond coats. The oxide content was examined by TEM and EDX analysis. HVOF-CoNiCrAlY bond coats show oxidation behaviour similar to coatings produced by LPPS.

Due to the electrochemical nature of MIC electrochemical methods are useful tools to study reactions at the metal/biofilm interface, investigate MIC mechanisms and monitor the onset of MIC and its propagation. The paper discusses various electrochemical methods—measurement of corrosion potential, redox potential, polarization resistance, galvanic currents, large signal polarization techniques, random potential pulse method, electrochemical impedance spectrometry, electrochemical relaxation methods (programmed pulse relaxation, sinusoidal ac relaxation), electrochemical noise analysis, scanning vibrating electrode techniques (Kelvin probe, vibrating microreference electrode, electrochemical sensors)–;with respect to their applicability and merits for MIC investigations and monitoring. Hochentwickelte elektrochemische Methoden zur Untersuchung und Uberwachung von mikrobiologisch beeinfluster Korrosion Aufgrund der elektrochemischen Natur der mikrobiologisch beeinflusten Korrosion (MIC) eignen sich elektrochemische Methoden sehr gut zum Studium der Reaktionen an der Phasengrenze Metall/Biofilm, zur Untersuchung von Reaktionsmechanismen und zur Uberwachung des Beginns und Fortschreitens von MIC. Der vorliegende Ubersichtsartikel diskutiert verschiedene elektrochemische Methoden–Messung des Korrosionspotentials, Redoxpotentials, Polarisationswiderstandes, galvanischer Elementstrome; Grossignal-Polarisationstechniken, Zufalls-Potentialpulsmethode, elektrochemische Impedanzspektrometrie, elektrochemische Relaxationsmethoden (programmierte Pulsrelaxation, sinusoidale Wechselstromrelaxation), elektrochemische Rauschanalyse, rasternde Vibrationselektrodentechniken (Kelvin Sonde, vibrierende Mikrobezugselektrode, elektrochemische Sensoren)unter Berucksichtigung ihrer Anwendungsbreite und Eignung fur Aufgaben der Untersuchung und Uberwachung, von MIC.

This paper presents a numerical study of the transient operation of a pre-pressurized (augmented) airbag inflator. Augmented inflators dilute hot gaseous products of propellant combustion with ambient temperature, high-pressure stored gas before discharging the mixture into the airbag. The solid propellant selected for this study is a non-azide propellant composed of a mixture of azodicarbonirnide, potassium perchlorate, and cupric oxide, Predicted performance of the inflator is presented in terms of pressure, temperature and mass flow rate profiles in the inflator and discharge tank which is used to simulate an airbag. This work also predicts first-order estimates of gas-phase species exit concentrations and characteristic residence times in the inflator. Carbon monoxide. produced as a product of combustion from the high flame temperature propellant, is partially converted to COz as it flows from an internal combustionchamber to the pressurized plenum before being discharged into the airbag, Spe...

The spin crossover transition curve of the compound (Fe(BPTN)(NCS)2) (BPTN=N,N'-bis(2-pyridylmethyl)-1,3-propanediamine) was measured by Mossbauer spectroscopy and susceptibility measurements. The compound was prepared by two different methods yielding a fine powder (a) and single crystals of approximately 0.5 mm in size (b). The transition temperatures T1/2 of the gradual transitions are 182 K (a) and 186 K (b). Within experimental accuracy the transition curves derived from the fractional absorption areas of the Mossbauer spectra are the same as derived from susceptibility measurements so that there is no indication for different Lamb Mossbauer factors of the high-spin (HS) and low-spin (LS) states as reported in the literature. The observation of quite different Debye temperatures Theta D at temperatures where the compounds are completely converted to the HS and LS state is discussed.

The detonation properties of several gaseous systems at elevated initial pressures were examined theoretically. The systems investigated include; hydrogen (H2), methane (CH4), ethylene (C2H4, ethan...

The characteristic “structure” of gaseous detonation waves, defined here as the spatial variation of the pressure, temperature, density, species concentrations, and velocity within the detonation wave is examined theoretically at elevated initial pressures. The approach taken in this work is to extend the Zel'dovich-von Neumann-Doering (ZND) theory of gas-phase detonation to use real-gas equations of state, Chemkin Real Gas, a computer program capable of calculating real-gas thermodynamic properties and chemical kinetic reaction rates, is used to describe the P-V-T behaviour of the gaseous mixtures in this investigation. The mathematical model for a ZND detonation wave is presented in an equation of state independent form and integrated numerically for a hydrogen-oxygen system to determine the structure of the detonation wave. The ZND model is used to characterize the thermodynamic states and reaction zone length scales present in the detonation wave. The variation of the reaction zone length par...

Time series of chlorophyll-a concentration (chl a), backscattering coefficient at 490 nm (bbp(490)) and spectral slope of bbp (γ) derived from satellite imagery of ocean color were used to study the aquatic ecosystem of the Southern Yellow Sea during the time period of 1997–2007. Our study indicated that chl a increased in offshore waters by 0.02 mg m−3 y −1 (p < 0.05), in contrast to a decline observed in the middle and low-latitude global waters. bbp(490), a proxy of total suspended particulate matter concentration did not have any significant trend, while γ, a proxy of the relative proportion of small-sized and larger particles in the surface ocean, decreased significantly. Annual spring phytoplankton blooms occurred in nearshore and offshore waters of the central Southern Yellow Sea; while autumn blooms only occurred in nearshore waters.

Ammonium Nitrate plus Fuel Oil (ANFO) is a non-ideal explosive where the mixing behavior of the mm-diameter prills with the absorbed fuel oil is of critical importance for chemical energy release. The large-scale heterogeneity of ANFO establishes conditions uniquely suited for observation using the spatially- and temporally-resolved line-imaging ORVIS (Optically Recording Velocity Interferometer System) diagnostic. The first demonstration of transmitted wave profiles in ANFO from planar impacts using a single-stage gas gun is reported. Major observations including an extended compaction precursor, post-shock particle velocity variations and between-prill jetting are reported.

The Lamb-Mossbauer factor in spin crossover compounds has been the subject of controversial discussions in the literature. For several compounds, a significantly larger Lamb-Mossbauer factor for the complex molecules in the low-spin (fls) than in the high-spin (fhs) state has been reported, while for compounds studied in our laboratory such differences could not be observed. We prepared the compound Fe(tpa)(NCS)2, thef factors of which were reported to be very different. We could not prove thef factors of this compound to be different. The implications of a different structural phase of compound prepared by us are discussed.

We have measured the energies and the Zeeman splitting of excitations of the non-ionized Li acceptor in CdTe by means of far-infrared absorption spectroscopy in order to determine the valence band parameters of the host material (0

The paper describes the experience gained in operating a membrane bioreactor (MBR) for the treatment of blackwater. Beside a complete characterization of blackwater, operational conditions and removal efficiency concerning parameters such as COD, BOD5, nitrogen and phosphorus as well as microbiological parameters were determined. Furthermore the membrane performance was investigated. The results show that in blackwater treatment nitrogen removal is limited in the biological process, because of the blackwater matrix (BOD5:TKN=1.1:1.0). Blackwater contains a high fraction of soluble, inert COD, which is not degradable by biological operation, only. Phosphorus elimination was negligible, probably induced by precipitation of cellular phosphorus. Although the released permeate was free of the fecal indicators E. coli and streptococcus and met guideline values, a direct reuse as service water is not recommended due to the yellowish coloration.

Scanning electron microscopy enables both a significantly higher magnification and an improved resolution of the various phases.The combination of SEM with energy-dispersive analysis of the induced X-rays is a powerful tool for the spacially resolved detection of specific elements. Only one metallographic cross section is necessary to perform all SEM and EDX investigations (detecting several different elements). Various sample preparations, implying different qualities of the cross section, are avoided. Utilizing the element-specific X-ray maps, the structural modifications in the solder joints due to thermal ageing can be studied in the most direct manner

A method for the simultaneous detection and quantification of cocaine and benzoylecgonine from human blood and urine has been developed. Cocaine and benzoylecgonine were extracted from blood and urine with solid-phase columns containing C18 packing material. Clean, emulsion-free extracts were obtained. The analytes were derivatized with PFPA/HFIP or iodomethane-D3. The underivatized cocaine and derivatized benzoylecgonine were determined by GC/MS with positive chemical ionization (PCI) and the selected ion monitoring mode. Benzoylecgonine was derivatized with iodomethane-D3 to cocaine-D3. Both derivatives were chromatographed on a CP-SIL 5 capillary column. The recovery of extraction was greater than 70%. The detection limit for the PFPA/HFIP derivatives (20 ng/mL) was better than that for iodomethane-D3 derivatives (40 ng/mL). The procedure is simple, rapid, and reproducible. Standard curves were linear and the procedure was suitable for routine analysis. Using fluorescence polarization immunoassay (TDx, Abbott) (cutoff 100 ng/mL), along with one of the GC/MS methods described, we found no false positive or false negative results.

MCrAlY-Haftschichten (M = Co und/oder Ni) fur keramische Warmedammschichten sind bei Betriebsbedingungen einem starken Oxidationsangriff ausgesetzt. Eine Moglichkeit, die Haftschichtoxidation zu verringern, besteht in der Verwendung von Diffusionssperrschichten. Auf die Haftschicht werden Diffusionssperrschichten aus Al2O3 mittels CVD, PVD und Plasma-Puls-Verfahren aufgebracht und einer isothermen Oxidationsbelastung (T = 1273 K, t = 250 h) bei atmospharischen Bedingungen unterworfen. Die PVD- und CVD-beschichteten Haftschichtproben weisen gegenuber unbeschichteten Proben stark reduzierte Oxidationsraten auf. Ein weiters Optimierungspotential des PVD- und CVD-Verfahrens scheint vorhanden. Das Plasma-Plus-Verfahren ist aufgrund der damit erhaltenen porosen Schicht zum Aufbringen des Oxidationsschutzes ungeeignet. Diffusion barriers of Al2O3 to reduce the bondcoat-oxidation of MCrAlY alloys Under operating conditions in gas turbines plasma sprayed MCrAlY bondcoats (M = Co and/or Ni) for thermal barrier coatings are exposed to a strong oxidation attack. One possibility to reduce bondcoat oxidation is the application of diffusion barriers. Onto the bondcoat, diffusion barriers of Al2O3 are deposited by CVD, PVD and plasma pulse process. The oxidation behaviour of these coating systems were examined at a temperature of 1273 K for times up to 250 hours. The CVD and PVD Al2O3-coated specimen show compared to the uncoated specimens smaller oxidation rates. The porous Al2O3 coatings, produced by plasma pulse process are not fit for oxidation protection of the bondcoat. There is hope for further improvement of the oxidation resistance by optimizing the CVD- and PVD- process parameters.

In einem betrieblichen Schadensfall wurde eine ungewohnlich schnell ablaufende Lochkorrosion an unlegiertem Stahl beobachtet. Nach Geschwindigkeit und Erscheinungsform der Locher hat diese Korrosionsart Ahnlichkeiten mit der Lochkorrosion nichtrostender Stahle. Abschatzungen uber die Kinetik der ortlichen Korrosion durch Beluftungselemente fuhrten zu einem Modell, das durch Stabilisierung kleiner Anodenflachen ausgezeichnet ist. Fur die Stabilisierung sind Fallungsprodukte verantwortlich, die durch Reaktion von Eisen-Ionen mit polymerem Silicat entstehen. Weiterhin weist die hohe Korrosionsgeschwindigkeit darauf hin, das erhohter Sauerstoffzutritt bei Betriebsphasen mit Auslagern an der Luft wirksam wird. Diese Vorstellungen konnten experimentell erhartet werden, wobei vor allem der Einflus der Konzentration an Neutralsalzen (NaCl) deutlich wird. Als Schutzmasnahme kommt eine anodische Passivierung durch Zugabe von Na2CO3, evtl. auch Inhibition in Frage. Fast pitting corrosion in a steel/water system as a result of unusual stabilization of anodes Corrosion damage as a result of fast pitting was observed in industrial equipment made of unalloyed steel. The rate of formation and the manifestation of the pits are similar to pitting corrosion of stainless steels. Estimation of the kinetics of the localized corrosion in terms of differential aeration cells led to a model which indicates the stabilization of small anodic regions. The stabilization was caused by precipitation of the products of reaction between ferrous ions and polymeric silicate. The high rate of pitting also suggests that the oxygen entering the system during service periods involving the exposure of the system to air has enhanced the corrosion. These ideas could be substantiated by experiments, which also revealed particularly the effect of the concentration of NaCl. Anodic passivation by the addition of Na2CO3 or perhaps inhibition may be considered as candidate protective measures.