Flexible Piezoelectric Drop-On-Demand Droplet Generation

[EN] The size of droplets generated by piezoelectric drop-on-demand (DOD) droplet generators can be varied to a certain degree within one order of magnitude. This variation means that the droplet size is not solely determined by the nozzle diameter, and the droplet generation process is not restricted to drops extruded through a nozzle in conventional operation. By varying the electronic driving pulse, different droplet sizes can be obtained. To investigate the interaction of piezoelectric pulse excitation and the finally produced droplets, different approaches are applied. A comparison of a modal analysis of a pure piezo based on mechanical admittance calculations proofs the usability of electrical impedance measurements. This kind of measurements are then compared to finite-element simulations of a coupled piezo system – one as actuator, the other as pressure sensor – to extend the usable methods with the result that the fluid is of minor influence on the modal frequencies. Last, two phase fluid flow simulations with consequent pressure wave evaluations of the fluid show different pressure wave frequency specta than the modal analysis.We would like to thank the German Research Foundation (DFG) for financial support of this project.Riefler, N.; Wriedt, T.; Fritsching, U. (2017). Flexible Piezoelectric Drop-On-Demand Droplet Generation. En Ilass Europe. 28th european conference on Liquid Atomization and Spray Systems. Editorial Universitat Politècnica de València. 621-627. https://doi.org/10.4995/ILASS2017.2017.484662162

The Arabidopsis TUMOR PRONE5 (TUP5) gene encodes an acetylornithine aminotransferase required for arginine biosynthesis and root meristem maintenance in blue light.

Arginine is an essential amino acid necessary for protein synthesis and is also a nitrogen storage compound. The genes encoding the enzymes of arginine biosynthesis in plants are not well characterized and have mainly been predicted from homologies to bacterial and fungal genes. We report the cloning and characterization of the TUMOR PRONE5 (TUP5) gene of Arabidopsis (Arabidopsis thaliana) encoding an acetylornithine aminotransferase (ACOAT), catalyzing the fourth step of arginine biosynthesis. The free arginine content was strongly reduced in the chemically induced recessive mutant tup5-1, root growth was restored by supplementation with arginine and its metabolic precursors, and a yeast (Saccharomyces cerevisiae) ACOAT mutant was complemented by TUP5. Two null alleles of TUP5 caused a reduced viability of gametes and embryo lethality, possibly caused by insufficient Arg supply from maternal tissue. TUP5 expression is positively regulated by light, and a TUP5-green fluorescent protein was localized in chloroplasts. tup5-1 has a unique light-dependent short root phenotype. Roots of light-grown tup5-1 seedlings switch from indeterminate growth to determinate growth with arresting cell production and an exhausted root apical meristem. The inhibitory activity was specific for blue light, and the inhibiting light was perceived by the root. Thus, tup5-1 reveals a novel role of amino acids and blue light in regulating root meristem function

A Constitutively Active Cytokinin Receptor Variant Increases Cambial Activity and Stem Growth in Poplar

The cambial meristem is responsible for bark and wood formation in woody plants. The activity of the cambial meristem is controlled by various factors; one of them is the plant hormone cytokinin. Here, we have explored different approaches to genetically engineering cambial activity in poplar plants by the ectopic expression of a cytokinin biosynthesis gene with enhanced activity (named ROCK4) or of a gene encoding a constitutively active cytokinin receptor variant (ROCK3). Both genes are derived from Arabidopsis thaliana and were expressed in poplar trees under the control of their own promoter or the cambium-specific pHB8 promoter. pIPT3:ROCK4- and pHB8:ROCK4-expressing plants were smaller than wild-type plants and formed more lateral branches; pHB8:ROCK4 transgenic plants additionally showed an increased stem diameter. In contrast, pAHK3:ROCK3- and pHB8:ROCK3-expressing plants grew taller than wild type without an altered branching pattern and formed more cambial cells, leading to increased radial stem growth. The effectivity of ROCK3 when expressed in either secondary phloem cells or in cambial cells is consistent with a dual, tissue-autonomous and non-autonomous activity of cytokinin in regulating cambial activity. We propose ROCK3 as a novel gene to enhance biomass formation in woody plants

EFFECTS OF HUMAN-ORANGUTAN COOPERATION AT THE INDIANAPOLIS ZOO

poster abstractThe Indianapolis Zoo is in the process of developing a new orangutan ex-hibit. The exhibit aims to help zoo guests develop an appreciation for the cognitive abilities of orangutans as well as understand how those abilities have helped the animals survive in the forest. The goals of the experience are to ultimately affect zoo guests’ attitudes and beliefs about orangutans and the importance of forest conservation. To that end, the zoo will be im-plementing interactive devices that allow orangutans living in the exhibit and zoo guests to work cooperatively on a series of discrete, individualized tasks. In the summer of 2011, IUPUI Museum Studies graduate students con-ducted visitor studies research and evaluation on a Chutes Interactive proto-type. The prototype invited research participants to cooperate with an orangutan by taking turns with the animal to rotate a series of chambers. With each rotation, a treat moved from the top of the device to a bottom chute, where the ape could retrieve it. Researchers used questionnaires, meaning mapping, and direct observa-tion methods to measure: 1) the extent of guest interaction at the device, 2) gains in general content knowledge/conceptual that occurred after the expe-rience, and 3) prototype functionality with regard to the exhibit goals and mechanics. Evaluation of the experience revealed that the cooperative expe-rience stimulated little long-term change in participant attitudes and behav-iors toward orangutans; that participants showed cognitive gain after the prototype activity, but not in knowledge areas identified as the core goals of the experience; and that design elements should be reconsidered to ensure the device would function properly more often

Lipid Extraction From Spirulina sp. and Schizochytrium sp. Using Supercritical CO2 With Methanol

Microalgae are one of the most promising feedstocks for biodiesel production due to their high lipid content and easy farming. However, the extraction of lipids from microalgae is energy intensive and costly and involves the use of toxic organic solvents. Compared with organic solvent extraction, supercritical CO2 (SCCO2) has demonstrated advantages through lower toxicity and no solvent-liquid separation. Due to the nonpolar nature of SCCO2, polar organic solvents such as methanol may need to be added as a modifier in order to increase the extraction ability of SCCO2. In this paper, pilot scale lipid extraction using SCCO2 was studied on two microalgae species: Spirulina sp. and Schizochytrium sp. For each species, SCCO2 extraction was conducted on 200 g of biomass for 6 h. Methanol was added as a cosolvent in the extraction process based on a volume ratio of 4%. The results showed that adding methanol in SCCO2 increased the lipid extraction yield significantly for both species. Under an operating pressure of 4000 psi, the lipid extraction yields for Spirulina sp. and Schizochytrium sp. were increased by 80% and 72%, respectively. It was also found that a stepwise addition of methanol was more effective than a one-time addition. In comparison with Soxhlet extraction using methylene chloride/methanol (2:1, v/v), the methanol-SCCO2 extraction demonstrated its high effectiveness for lipid extraction. In addition, the methanol-SCCO2 system showed a high lipid extraction yield after increasing biomass loading fivefold, indicating good potential for scaling up this method. Finally, a kinetic study of the SCCO2 extraction process was conducted, and the results showed that methanol concentration in SCCO2 has the strongest influence on the lipid extraction yield

Investigation of Electrolytic Flocculation for Microalga Scenedesmus sp Using Aluminum and Graphite Electrodes

Electrolytic flocculation using non-sacrificial electrodes with flocculants added was studied on harvesting Scenedesmus sp. In order to optimize the operating conditions of the electrolytic flocculation process and to quantify the amount of flocculants added, aluminum electrodes were first used in the process. It was found that under optimal conditions, the microalgae removal efficiency using aluminum electrodes could reach 98.5%, while 34.2 mg L-1 of aluminum ions were released during the process. Different metal electrodes were also studied, but high microalgae removal efficiency was witnessed only using aluminum electrodes, indicating the influence of the aluminum ion in flocculation. When non-sacrificial graphite electrodes were used in the electrolytic flocculation process, the corresponding amount of aluminum sulfate was added so that the aluminum ion concentration in water was also equal to 34.2 mg L-1. The result showed that the microalgae removal efficiency of graphite electrodes could reach above 90% after aluminum sulfate was added. In contrast, using graphite electrodes alone and using the metal salt alone only yielded 22.9% and 7.1% of microalgae removal efficiency, respectively. These results indicated that the presence of metal ions is necessary in the electrolytic flocculation process. The energy consumption of the process was found to be 0.3 kW h m-3 or 0.88 kW h kg-1, which is considered to be low energy consumption. The total cost of the process, including energy and chemicals, was found to be $ 0.21 m-3, proving a cost competitive method in microalgae harvesting

Indulge or Reduce? A cross-country investigation of consumption patterns following pandemic lockdowns

Pandemic lockdowns in early 2020 disrupted daily lifestyles worldwide and opened a window of opportunity for self-reflection and consumption paradigm shifts. However, consumption patterns might take different directions and opposing views exist about whether consumers (1) prolong consumption-oriented lifestyles post-lockdown, or (2) compensate for lockdown consumption restrictions through self-indulgence. Drawing from self-determination theory and individual-cultural values frameworks, this paper develops a conceptual model of post-lockdown consumption patterns related to three factors: consumers’ fulfilment of basic psychological needs during lockdowns, individual consumer values, and country-level cultural orientations. Consumer surveys conducted after the first lockdowns in three culturally different European countries (UK, Germany, Romania) show that both satisfaction and dissatisfaction of psychological needs during lockdown impact consumption patterns, at least at a short-term level. The direction of consumption patterns is driven by hedonism and universalism values at an individual level and differences in post-materialism and indulgence at a country-level. The results provide implications for international marketers and policymakers in post-pandemic marketplaces

The role of gender in sales behaviour: Evidence from institutional financial brokerage

We study the role of gender in sales behaviour using 336,401 daily institutional broker transactions over two years. Female brokers appear more efficient at generating revenue than males. Their more cautious sales behaviour sees them execute fewer transactions and sell lower risk financial products to more conservative clients. Directionally supportive of literature that records higher confidence levels, trading frequency and risk taking among males, we show how female brokers contribute to more diversified and successful sales behaviour. Our findings are relevant to gender unequal financial services industry and other quantitative domains that tend to overvalue male relative to female skills

Novel perspectives for the application of total internal reflection microscopy

Total Internal Reflection Microscopy (TIRM) is a sensitive non-invasive technique to measure the interaction potentials between a colloidal particle and a wall with femtonewton resolution. The equilibrium distribution of the particle-wall separation distance z is sampled monitoring the intensity I scattered by the Brownian particle under evanescent illumination. Central to the data analysis is the knowledge of the relation between I and the corresponding z, which typically must be known a priori. This poses considerable constraints to the experimental conditions where TIRM can be applied (short penetration depth of the evanescent wave, transparent surfaces). Here, we introduce a method to experimentally determine I(z) by relying only on the distance-dependent particle-wall hydrodynamic interactions. We demonstrate that this method largely extends the range of conditions accessible with TIRM, and even allows measurements on highly reflecting gold surfaces where multiple reflections lead to a complex I(z).Comment: 11 pages, 7 figure

Mind the gap: Lücke in der Masern-IgG-Antikörper-Prävalenz bei Kindern unter zwei Jahren in Niedersachsen und Bremen

Säuglinge und Kinder bis zum zweiten Lebensjahr sind eine besonders vulnerable Gruppe für Maserninfektionen. Für sie werden in Deutschland gegenüber anderen Altersgruppen zwei- bis 40-fach höhere Erkrankungsinzidenzen beobachtet und sie sind häufiger von schweren, komplikationsbehafteten Verläufen betroffen. Gegenüber Säuglingen, deren Mütter eine Masernimmunität aufgrund einer Masernwildvirusinfektion erworben haben, ist der Nestschutz bei Säuglingen von ausschließlich durch die Impfung immunisierten Müttern verkürzt. Detaillierte Seroprävalenzdaten für unter Zweijährige lagen in Deutschland jedoch bisher nicht vor. In der vorliegenden Studie wurden Masern-IgG-Antikörperbestimmungen aus den Jahren 2006 bis 2019 von 1.523 Kindern unter zwei Jahren nach Altersgruppen stratifiziert ausgewertet. Es zeigte sich, dass spätestens nach dem 9. Lebensmonat keine maternalen Masern-IgG-Antikörper mehr nachweisbar sind. Die Ergebnisse stützen somit die derzeitige Empfehlung, bei erhöhtem Exposi-tionsrisiko den Zeitpunkt der ersten MMR-Impfung auf neun Monate vorzuverlegen und unterstreichen die Notwendigkeit, Impfquoten insbesondere bei Kleinkindern, aber auch bei jungen Erwachsenen zu steigern.Peer Reviewe