Rippled area formed by surface plasmon polaritons upon femtosecond laser double-pulse irradiation of silicon: the role of carrier generation and relaxation processes

The formation of laser-induced periodic surface structures (LIPSS, ripples) upon irradiation of silicon with multiple irradiation sequences consisting of femtosecond laser pulse pairs (pulse duration 150 fs, central wavelength 800 nm) is studied numerically using a rate equation system along with a two-temperature model accounting for one- and two-photon absorption and subsequent carrier diffusion and Auger recombination processes. The temporal delay between the individual equal-energy fs-laser pulses was varied between $0$ and $\sim 4$ ps for quantification of the transient carrier densities in the conduction band of the laser-excited silicon. The results of the numerical analysis reveal the importance of carrier generation and relaxation processes in fs-LIPSS formation on silicon and quantitatively explain the two time constants of the delay dependent decrease of the Low-Spatial-Frequency LIPSS (LSFL) area observed experimentally. The role of carrier generation, diffusion and recombination are quantified individually.Comment: 5 pages, 5 figures, Conference On Laser Ablation (COLA) 2013. The final publication is available at http://link.springer.com. Accepted for publication in Applied Physics

Neuromarketing - Findings for Brand Management

Ziel ist es, einen Überblick über die neurowissenschaftlichen Erkenntnisse zu liefern und wie diese in der Markenführung erfolgreich umgesetzt werden können. Die Ergebnisse können Unternehmen helfen, ihre Produkte zielgerichtet zu vermarkten und das Kaufverhalten der Konsumenten zu beeinflussen. In besonderem Maße soll dabei auf die Literatur von Dr. Hans Georg Häusel verwiesen werden, der als Vorreiter auf diesem recht neuen Wissenschaftsgebiet bezeichnet werden kan

The feasibility of wastewater recycling that includes residue from dissolved air flotation within a drinking water treatment plant: case study of Midvaal Water Company, South Africa

When purifying water for potable use, wastewater is generated, due to the class of the water treatment plant and the quality of the source water. Midvaal Water Company recycled wastewater that included residue from the dissolved air flotation (DAF), sedimentation and filtration processes in an attempt to save water and reduce costs. The aim of this study was to determine functionality and water quality of such a wastewater recycling system. Samples were collected for analysis, at the sections that contributed to the total wastewater system as well as after various treatment processes. The water quality of these samples was determined, as well as the incidences of water quality failures of the final water, to establish whether the recycle stream that enters the plant together with the source water had any impact on the water quality after the different treatment processes. Data were grouped into periods prior to, during and after recycling to enable comparisons. The water quality of the recycle stream was poorer than that of the source water from the Vaal River with regard to the mean values for total chlorophyll, suspended solids, turbidity and dissolved organic carbon, but the sedimentation process of the wastewater system improved the wastewater quality by drastically reducing total chlorophyll, suspended solids and turbidity. The risk-defined compliance for the final water was excellent (≥95%), despite aluminium, turbidity and total chlorophyll failures of the final water quality during the recycling period. Total chlorophyll was identified as the largest risk during wastewater recycling, especially after the filtration process. It is evident from the data that wastewater recycling, which included wastewater from the DAF, into the main inlet stream of the water treatment plant proved to be effective, based on compliance with national legislation, and had no detrimental impact on overall treatment processes or final water quality.Keywords: dissolved air flotation, sludge balancing dam, total chlorophyll, wastewater recycling, water treatmen

Challenges in the potable water industry due to changes in source water quality: case study of Midvaal Water Company, South Africa

Midvaal Water Company treats hypertrophic water abstracted from the Vaal River to supply bulk wholesome potable water to their consumers in compliance with the South African National Standard (SANS) 241:2015 for drinking water. The facility incorporates conventional and advanced treatment processes. The aims of the study were to identify how the water treatment processes of the plant have changed over time in response to the varying water quality of the Vaal River, and to consider both current and future obstacles as well as possible solutions regarding water quality and treatment. Oxidation steps such as pre-chlorination, potassium permanganate addition, pre-ozonation and intermediate ozonation have either been applied in the past or are still operational. The dissolved air flotation plant accounts for almost 70% of total chlorophyll removal and the significance of this process was confirmed during a brief maintenance shutdown during 2015. Total chlorophyll concentrations of the source water have increased extensively since 1984, while turbidity levels have remained fairly constant but with spikes at times. The facility suffers from severe taste and odour episodes during warm periods due to the presence of methylisoborneol (MIB), released by Cyanophyceae, in the Vaal River. Concentrations of > 300 ng/L MIB have been recorded, whereas the odour threshold concentration for MIB ranges from 4 ng/L to 20 ng/L. The additional application of activated carbon to alleviate taste and odour problems has to be weighed against the cost implications for consumers, the correct type to be purchased for the organic molecules to be adsorbed, the interference of natural organic matter, and the formation of additional sludge mass, as well as the intensity and duration of taste and odour events. Midvaal remains a bulk potable water supplier and therefore has to consider the socio-economic status of their consumers where water pricing is concerned. The study ultimately emphasized the intrinsic value of protecting water resources.Keywords: oxidation processes, dissolved air flotation, chlorophyll a, taste and odou

Gastric carcinomas with stromal b7-h3 expression have lower intratumoural cd8+ t cell density

Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.CD8+ T cells are the main effector cells of anti-cancer immune response that can be regulated by various costimulatory and coinhibitory molecules, including members of the B7 family. B7 homolog 3 (B7-H3) appears as a promising marker for immunotherapy; however, its significance in gastric cancer (GC) is unclear yet. We evaluated the spatial distribution of CD8+ T cells in relation to the expression of B7-H3 by double immunohistochemical staining. The level of B7-H3 intensity was scored manually (0-3) and dichotomized into B7-H3-low and B7-H3-high groups. The distribution and density of CD8+ T cells was analysed using whole slide digital imaging. B7-H3 was expressed mainly in the stromal compartment of GC (n = 73, 76% of all cases). Tumours with high expression of B7-H3 showed larger spatial differences of CD8+ T cells (86.4/mm2 in tumour centre vs. 414.9/mm2 in invasive front) when compared to B7-H3-low group (157.7/mm2 vs. 218.7/mm2, respectively) (p < 0.001). This study provides insight into the expression pattern of B7-H3 in GC of Western origin. In GCs with higher level of B7-H3 expression, CD8+ T cells were spatially suppressed in the tumour centre suggesting that B7-H3 might be involved in tumour escape mechanisms from the immune response.publishersversionPeer reviewe

Rippled area formed by surface plasmon polaritons upon femtosecond laser double-pulse irradiation of silicon

International audienceThe formation of near-wavelength laser-induced periodic surface structures (LIPSS) on silicon upon irradiation with sequences of Ti:sapphire femtosecond laser pulse pairs (pulse duration 150 fs, central wavelength 800 nm) is studied theoretically. For this purpose, the nonlin-ear generation of conduction band electrons in silicon and their relaxation is numerically calculated using a two-temperature model approach including intrapulse changes of optical properties, transport, diffusion and recombina-tion effects. Following the idea that surface plasmon polaritons (SPP) can be excited when the material turns from semiconducting to metallic state, the "SPP active area" is calculated as function of fluence and double-pulse de-lay up to several picoseconds and compared to the experimentally observed rippled surface areas. Evidence is presented that multi-photon absorption explains the large increase of the rippled area for temporally overlapping pulses. For longer double-pulse delays, relevant relaxation processes are identified. The results demonstrate that femtosecond LIPSS on silicon are caused by the excitation of SPP and can be controlled by temporal pulse shaping. ©2013 Optical Society of America OCIS codes: (050.6624) Subwavelength structures; (140.3390) Laser materials processing; (160.6000) Semiconductor materials; (240.5420) Polaritons

Large impact of the apoplast on somatic embryogenesis in Cyclamen persicum offers possibilities for improved developmental control in vitro

<p>Abstract</p> <p>Background</p> <p>Clonal propagation is highly desired especially for valuable horticultural crops. The method with the potentially highest multiplication rate is regeneration via somatic embryogenesis. However, this mode of propagation is often hampered by the occurrence of developmental aberrations and non-embryogenic callus. Therefore, the developmental process of somatic embryogenesis was analysed in the ornamental crop <it>Cyclamen persicum </it>by expression profiling, comparing different developmental stages of embryogenic cell cultures, zygotic vs. somatic embryos and embryogenic vs. non-embryogenic cell cultures.</p> <p>Results</p> <p>The analysis was based on a cDNA microarray representing 1,216 transcripts and was exemplarily validated by realtime PCR. For this purpose relative transcript abundances of homologues of a putative receptor kinase, two different glutathione S-transferases (GST), a xyloglucan endotransglycosylase (XET) and a peroxidase (POX) were quantitatively measured by realtime PCR for three different comparisons. In total, 417 genes were found to be differentially expressed. Gene Ontology annotation revealed that transcripts coding for enzymes that are active in the extracellular compartment (apoplast) were significantly overrepresented in several comparisons. The expression profiling results are underpinned by thorough histological analyses of somatic and zygotic embryos.</p> <p>Conclusions</p> <p>The putative underlying physiological processes are discussed and hypotheses on improvement of the protocol for <it>in vitro </it>somatic embryogenesis in <it>Cyclamen persicum </it>are deduced. A set of physiological markers is proposed for efficient molecular control of the process of somatic embryogenesis in <it>C. persicum</it>. The general suitability of expression profiling for the development and improvement of micropropagation methods is discussed.</p

Wolgograd wählt: Ergebnisse einer Beobachtermission in der russischen Provinz

Der lokale Wahlkampf in Wolgograd anläßlich der russischen Parlamentswahlen am 17. Dezember 1995 hatte mit dem Geschehen in der Hauptstadt nur vermittelt zu tun. Die örtlichen Parteiorganisationen haben teilweise eigene Programme entwickelt, die mit den Vorgaben ihrer Moskauer Zentralen häufig wenig übereinstimmen. Das soziale Klima der Region ist ganz wesentlich durch die Krise der regionalen Schwerindustrie bestimmt, und dementsprechend stark sind rechte und linke oppositionelle Strömungen. Der Wahlprozeß war gut organisiert und erfüllte die Bedingungen einer freien und fairen Wahl. Sieger in Wolgograd wurde die Kommunistische Partei der Russischen Föderation (KPRF) mit 31%. (BIOst-Mrk

Autonomous Characterization of Lithium-Ion Battery Model Parameters utilizing a Mathematical Optimization Methodology

Kalman filtering is commonly used for state-of-charge (SOC) estimation for lithium-ion (Li-ion) batteries owing to its simplicity, computational efficiency, and relatively precise results. However, kalman filters depend on the Li-ion battery model. Several laboratory tests such as incremental current and dynamic stress tests are required to determine battery model parameters in model-based SOC estimation. These tests such as incremental current test and dynamic stress test are time-consuming and can take multiple days. A mathematical optimization along with a battery test method, which does not need rest time for battery, are adopted to reduce the battery parameter identification time, drastically. A mathematical optimization stage is embedded prior to Kalman Filter based SOC estimation computing the battery open circuit voltage (OCV) and as well as an initial guess of the RC parameters of the battery equivalent circuit. Therefore, it reduces the required number of tests to one. Extensive numerical studies on a 2 Ah Lithium-ion cell verify the effectiveness of the proposed method by achieving a RMS error less than one percent