The interaction of 10.6 μm laser radiation with liquids

The interaction of a pulse from a TEA laser with the free liquid surface of water and chloroform, is recorded by high-speed photography. The phenomena is similar to the high velocity impact of a projectile with a liquid or solid surface.\ud \ud A vapour cloud, above the liquid, expands with an initial velocity of 1500 m s−1 and a violent disturbance below the liquid surface is observed. In the case of chloroform, a cloud of small bubbles is produced. A shock wave model is proposed to account for the disturbance below the surface of the liquid

The cytodisk: A cytometer based upon a new principle of cell alignment

A new method is described for one-dimensional alignment of small particles such as biological cells. A drop of the particle suspension is spread out on a flat disk or plate equipped with V-shaped grooves such as are present on a gramophone disk. After drying, the particles are located on the bottom of the grooves and are thus aligned in a one-dimensional array. The new alignment procedure is demonstrated with a suspension of fluorescent polystyrene micropheres (diameter 3.8 µm) and a suspension of the unicellular algae chlorella vulgaris (diameter about 3 µm). It appears that the alignment of cells and spheres is very good. \ud When using microspheres, more than 95% of the particles in the grooves are located within ±2 µm of the centre line of the groove. Based upon this cell-alignment principle, a new cytometer, named the cytodisk, is proposed. The proposed system has a number of advantages over the flow cytometer, among which is the unique ability of relocating a previously measured cell for further measurement or visual examination. \ud A prototype of a cytodisk, developed for initial test measurements, was built in our laboratory. The apparatus, constructed from a record player and ordinary long-playing records, uses a simple mechanical tracking system and a single optical fiber for fluorescence excitation and detection. With this apparatus it is demonstrated that a cytodisk can indeed perform quite well: A histogram of fluorescing microspheres could be measured with a coefficient of variation of 4.1%. The performance of this prototype is limited by the quality of the mechanical tracking system and the optical system used. It is expected that considerable improvements may be obtained by using a more sophisticated optical detection system such as the tracking system in use in optical disk players

Emulsification with micro-engineered devices

This thesis deals with the formation of emulsions using micro-engineered devices. It covers devices made from silicon nitride, metals and polymers using different types of micro-processing tools for their fabrication. In order to produce water-in-oil emulsions, surface modifications were applied to render the surface of the metal and silicon nitride devices hydrophobic

‘Die Vorliebe der Niederländer für helle, freundliche Zimmer’. Oldenburgs stucwerk in Nederland tussen 1775 en 1925

‘Dutchmen like light, representative interiors’, according to several Germans in the nineteenth century. They referred to the taste in living of above-average citizens. Evidently, there was a preference for white, sometimes also for bright colours. In the period 1775-1925 more than a thousand Oldenburg plasterers earned a living from the taste of Dutch citizens. The farmer’s son J.B. Logeman (1748-1814) from Oldenburg was the first. In Amsterdam he learned the plasterer’s craft and was quite successful in the Northern Netherlands and Germany. This inspired people from the same regions. What they made, who commissioned them, how they worked and where, varies during three sub-periods between 1775 and 1925. High-quality craftsmanship characterizes Oldenburg stuccowork in the pioneering phase from 1775 to 1825. For instance, Logeman contributed to the spread of neo-classicism in the Northern Netherlands. He obtained his exclusive position because of the demand for stuccowork among the private and public elite, and through exceptional instruments such as exclusive rights and building fraud. The artistic craft was a steppingstone for the niches in the free regional markets during the subsequent period. Between 1825 and 1875 the Oldenburg craftsmen supplied good-quality interiors as well as exterior walls at a good price, chiefly designed according to the current taste. The formula for success in a time of small economic margins – here industrialization had not broken through yet – was the smoothly running cooperation between emigrant and seasonal worker. The emigrant, who often married a Dutch woman, obtained commissions through the local network and organized the stream of seasonal workers from his native region in such a way that the demand for custom-made stuccowork, varying per season, was provided for. In the course of the nineteenth century a lot of ornamental cast stuccowork was applied in the houses of above-average citizens. This had to be cleaned and whitewashed regularly because of the build-up of soot caused by stoves. When industrialization broke through in the Netherlands, migration from Oldenburg declined with ups and downs. The market for stuccowork grew during the period 1875-1925, wages increased and more Dutchmen became plasterers, but the Oldenburg entrepreneurs were scarcely active in revolutiebouw (jerry building) and lost position due to the tenders, which were practised on a larger scale. At that time Oldenburg stucco workers already found well-paid work in Germany more frequently. In the Netherlands the demand also changed. Washable wallpaper, which was produced in a mechanized process from 1875 onwards, was cheaper to purchase and maintain than stuccowork. Moreover, oil paint obtained a larger share in the finishing. The emigrants and their descendants remained active as established plasterers’ companies, but they integrated fully in the Netherlands trade organizations. The Oldenburg tradition started in Amsterdam and Groningen and spread in many regions north of the large rivers. In the period 1775-1925 these Lutheran craftsmen did not go to the South, where the Roman-Catholic tradition was dominant. Since 2010 the author has registered personal data and works of Oldenburg plasterers in the Netherlands. For his research he requests readers to report plasterers with German names who worked in the Netherlands between 1775 and 1925. It is quite likely that they were of Oldenburg origin

Impact of salinity on element incorporation in two benthic foraminiferal species with contrasting magnesium contents

Accurate reconstructions of seawater salinity could provide valuable constraints for studying past ocean circulation, the hydrological cycle and sea level change. Controlled growth experiments and field studies have shown the potential of foraminiferal Na ∕ Ca as a direct salinity proxy. Incorporation of minor and trace elements in foraminiferal shell carbonate varies, however, greatly between species and hence extrapolating calibrations to other species needs validation by additional (culturing) studies. Salinity is also known to impact other foraminiferal carbonate-based proxies, such as Mg ∕ Ca for temperature and Sr ∕ Ca for sea water carbonate chemistry. Better constraints on the role of salinity on these proxies will therefore improve their reliability. Using a controlled growth experiment spanning a salinity range of 20 units and analysis of element composition on single chambers using laser ablation-Q-ICP-MS, we show here that Na ∕ Ca correlates positively with salinity in two benthic foraminiferal species (<i>Ammonia tepida</i> and <i>Amphistegina lessonii</i>). The Na ∕ Ca values differ between the two species, with an approximately 2-fold higher Na ∕ Ca in <i>A. lessonii</i> than in <i>A. tepida</i>, coinciding with an offset in their Mg content ( ∼  35 mmol molM<super>−2</super> versus  ∼  2.5 mmol mol−<super>1</super> for <i>A. lessonii</i> and <i>A. tepida</i>, respectively). Despite the offset in average Na ∕ Ca values, the slopes of the Na ∕ Ca–salinity regressions are similar between these two species (0.077 versus 0.064 mmol mol<super>−1</super> change per salinity unit). In addition, Mg ∕ Ca and Sr ∕ Ca are positively correlated with salinity in cultured <i>A. tepida</i> but show no correlation with salinity for <i>A. lessonii</i>. Electron microprobe mapping of incorporated Na and Mg of the cultured specimens shows that within chamber walls of <i>A. lessonii</i>, Na ∕ Ca and Mg ∕ Ca occur in elevated bands in close proximity to the primary organic lining. Between species, Mg banding is relatively similar, even though Mg content is 10 times lower and that variation within the chamber wall is much less pronounced in <i>A. tepida</i>. In addition, Na banding is much less prominent in this species than it is in <i>A. lessonii</i>. Inter-species differences in element banding reported here are hypothesized to be caused by differences in biomineralization controls responsible for element uptake

Systemic Inflammatory Effects of Traumatic Brain Injury, Femur Fracture, and Shock: An Experimental Murine Polytrauma Model

Objective. Despite broad research in neurotrauma and shock, little is known on systemic inflammatory effects of the clinically most relevant combined polytrauma. Experimental investigation in an animal model may provide relevant insight for therapeutic strategies. We describe the effects of a combined injury with respect to lymphocyte population and cytokine activation. Methods. 45 male C57BL/6J mice (mean weight 27 g) were anesthetized with ketamine/xylazine. Animals were subjected to a weight drop closed traumatic brain injury (WD-TBI), a femoral fracture and hemorrhagic shock (FX-SH). Animals were subdivided into WD-TBI, FX-SH and combined trauma (CO-TX) groups. Subjects were sacrificed at 96 h. Blood was analysed for cytokines and by flow cytometry for lymphocyte populations. Results. Mortality was 8%, 13% and 47% for FX-SH, WD-TBI and CO-TX groups (P < 0.05). TNFα (11/13/139 for FX-SH/WD-TBI/CO-TX; P < 0.05), CCL2 (78/96/227; P < 0.05) and IL-6 (16/48/281; P = 0.05) showed significant increases in the CO-TX group. Lymphocyte populations results for FX-SH, WD-TBI and CO-TX were: CD-4 (31/21/22; P = n.s.), CD-8 (7/28/34, P < 0.05), CD-4-CD-8 (11/12/18; P = n.s.), CD-56 (36/7/8; P < 0.05). Conclusion. This study shows that a combination of closed TBI and femur-fracture/ shock results in an increase of the humoral inflammation. More attention to combined injury models in inflammation research is indicated

Reliability and validity of neurobehavioral function on the Psychology Experimental Building Language test battery in young adults

Background. The Psychology Experiment Building Language (PEBL) software consists of over one-hundred computerized tests based on classic and novel cognitive neuropsychology and behavioral neurology measures. Although the PEBL tests are becoming more widely utilized, there is currently very limited information about the psychometric properties of these measures. Methods. Study I examined inter-relationships among nine PEBL tests including indices of motor-function (Pursuit Rotor and Dexterity), attention (Test of Attentional Vigilance and Time-Wall), working memory (Digit Span Forward), and executive-function (PEBL Trail Making Test, Berg/Wisconsin Card Sorting Test, Iowa Gambling Test, and Mental Rotation) in a normative sample (N = 189, ages 18–22). Study II evaluated test–retest reliability with a two-week interest interval between administrations in a separate sample (N = 79, ages 18–22). Results. Moderate intra-test, but low inter-test, correlations were observed and ceiling/floor effects were uncommon. Sex differences were identified on the Pursuit Rotor (Cohen’s d = 0.89) and Mental Rotation (d = 0.31) tests. The correlation between the test and retest was high for tests of motor learning (Pursuit Rotor time on target r = .86) and attention (Test of Attentional Vigilance response time r = .79), intermediate for memory (digit span r = .63) but lower for the executive function indices (Wisconsin/Berg Card Sorting Test perseverative errors = .45, Tower of London moves = .15). Significant practice effects were identified on several indices of executive function. Conclusions. These results are broadly supportive of the reliability and validity of individual PEBL tests in this sample. These findings indicate that the freely downloadable, open-source PEBL battery (http://pebl.sourceforge.net) is a versatile research tool to study individual differences in neurocognitive performance

Revision of the EU Green Public Procurement Criteria for Street Lighting and Traffic Signals - Preliminary Report

Lighting is used on more than 1.6 million km of roads in EU28 countries, accounting for some 35 TWh of electricity consumption (1.3% of total electricity consumption) and costing public authorities almost €4000 million each year. A broad review of relevant technical, policy, academic and legislative literature has been conducted. This report examines the current market situation and the potential for reducing environmental impacts and electricity costs by assessing the recent developments in road lighting technology, particularly LEDs. Particularly important areas identified relate to energy efficiency, light pollution, product durability and, specifically for longer lasting and rapidly evolving new LED technologies, reparability and upgradeability. The information in this report shall serve as a basis for discussion with stakeholders about the further development and revision of EU GPP criteria for street lighting and traffic signals.JRC.B.5-Circular Economy and Industrial Leadershi