Results of investigations on a 0.010-scale model of the configuration 3 space shuttle orbiter and external tank in the NASA/Ames Research Center 3.5-foot hypersonic wind tunnel (IA15)

Experimental aerodynamic investigations were conducted in a 3.5-foot hypersonic wind tunnel. The model used for this test was a 0.010-scale of the Configuration 2 Space Shuttle Orbiter and the External Tank. Six-component aerodynamic force and moment data were recorded over an angle of attack range from -8 deg to +30 deg at 0 deg and 5 deg angles of sideslip. Data was also recorded during beta sweeps of -8 deg to +10 deg at angles of attack of -10 deg, 0 deg, and 30 deg. All testing was done at Mach 7.3. Various elevon, rudder and orbiter to external tank attaching structures and fairings were tested to determine longitudinal and lateral-directional stability characteristics. Non-metric exhaust plumes were installed during a portion of the testing to determine the effects of the main propulsion system rocket plumes

Influence of mixing on the azo-coupling of 1-naphthol and diazotized aniline

The azo-coupling reaction between 1-naphthol and diazotized aniline in alkaline media has been studied. It is shown that the product distribution is mixing-dependent. Reaction is rapid, and the kinetically controlled regime is reached only at high stirrer speeds

Biological cyanide degradation in aerobic fluidized bed reactors : treatment of almond seed wastewater

Erworben im Rahmen der Schweizer Nationallizenzen (http://www.nationallizenzen.ch)The continuous aerobic transformation of synthetic cyanide waste-water, amygdalin solutions and almond seed extract containing cyanide was investigated in several fluidized bed reactors. Various inocula consisting of activated sludge or soil slurry were used. Successful inoculation was achieved with simple soil slurry. No significant influence was found between the performance of the systems inoculated with a cyanide contaminated soil and a garden soil. The performance and stability of the reactors with respect to degradation rate were tested for a range of cyanide loading conditions, with feed containing only cyanide, and with different additional carbon sources, as well as various C∶N ratios at a hydraulic retention time of 24 h. No growth with cyanide as the sole source of carbon and nitrogen was observed. The system with lactate as the organic C-source was capable of operating at cyanide concentrations of 160 ppm cyanide with a conversion rate of 0.125 kg cyanide/m3 d. Ammonia was the end product and the effluent concentration was 0.5 ppm CN-. The systems with ethanol as the organic C-source could degrade only 0.05 kg cyanide/m3 d, whose feed concentration was 60 ppm cyanide. Amygdalin, an organic cyanide-containing compound present in stone fruit seeds, was fed as a model substrate. Degradation rates up to 1.2 kg COD/m3 d could be measured with no free or organically bound cyanide in the effluent. These rates were limited by oxygen transfer, owing to the large amount of degradable COD. The further investigations with almond seed extracts, confirmed the applicability of the aerobic process to treat food-processing waste streams having low concentrations of cyanide with high COD content

Efficient dye adsorption by highly porous nanofiber aerogels

Electrospun nanofiber membranes are frequently used in adsorption processes thanks to their high specific surface area, tailored surface functionality, and fiber uniformity. However, they are still facing challenges such as low mechanical stability and unfavorable mass transport properties. In this study, an ultra-light and robust 3D nanofiber aerogel (NFA) or nanofiber sponge with tunable porosity and flexibility was synthesized from short pullulan/polyvinyl alcohol/polyacrylic acid nanofibers using a freeze casting process followed by thermal crosslinking. We demonstrate time the application of such NFAs in batch and continuous adsorption systems and compare their performance with flat nanofiber membranes (NFM). The NFAs proved to be promising adsorbents for cationic dyes due to their high adsorption capacity (383 mg/g) and their reusability. Langmuir isotherm was a suitable model for describing the adsorption process. The endothermic system followed a pseudo second order kinetic model and intra-fiber adsorption is found to be involved in the adsorption process. Dye adsorption by 3D NFAs was four times faster than for the respective flat NFMs and when used in a continuous process as a deep-bed filter, the pressure drop through the NFA was reduced by a factor of 40 while maintaining equal adsorption performance as for the NFM

Sustainability code / load index for the semi-quantitative assessment of analytical methods in a research environment : proof of concept

The aim of this project was to develop a general concept to assess the laboratory experiments in the instrumental analysis laboratory, at the Institute of Chemistry and Biological Chemistry (ICBC) at the Zurich University of Applied Sciences (ZHAW), in terms of their sustainability and, where possible, to improve the sustainability rating of the laboratory experiments. Hence, the primary objective was to implement an empirical assessment methodology, including the “Sustainability Code” that was composed of four parts and a “Sustainability Load Index”. During the spring semester 2015, 105 different experimental projects were performed in the ICBC’s analytical chemistry practical course. These were carried out on 18 different instrumental workspaces, encompassing 12 different analytical methodologies. For the development of the first and second parts of the Sustainability Code, information concerning the chemical substances (in any state- solid, liquid or gas) used and the energy consumption of the apparatus was recorded. The third and fourth parts contain (approximate) information on the use of consumables and the sustainability of the method with reference to the apparatus used. The Load Index (LI) consists of an aggregation (summary) of the direct causality indicators ‘substances’ and ‘energy’ into a single figure. The experiments were classified on a 3-level Load Index Scale into ‘ideal’ analysis methods (LI> 20), ‘sustainable’ methods of analysis (LI 20-200), and analysis methods ‘with potential for optimization’ (LI <200). The assessment criteria described here, specifically designed for an analytical process in a university environment, may also serve as a useful guide for semi-quantitative assessment of both familiar and new methods in analytical chemistry practical courses and in laboratory practice. It may also be useful in general research laboratory environments

First assessment of age and sex structures of elephants by using dung size analysis in a West African savannah

1. An age and sex structure study of the West African savannah elephant (Loxodonta africana africana) population&nbsp;of the Nazinga Game ranch (Burkina Faso) was carried out using direct sightings of individuals near water&nbsp;points, where they group during hot periods of the day, and droppings circumference measurements of dung&nbsp;pile along line transects, during the dry seasons of 2007 and 2008. The age structure, from direct observation&nbsp;data, was estimated by classifying the individuals into 9 age-class-categories based on body size and eruption&nbsp;(length) of tusks.2. The frequency distribution of number of individuals into the age-class-categories showed high similarity&nbsp;with the distribution of circumference measurements of dung-piles that the individuals were seen depositing.&nbsp;Fifty dung-piles measured soon after they were deposited (Class A) and after they dried (to class C) showed&nbsp;a significant difference between the circumference measurements in relation to the time elapsed between the&nbsp;measurements.3. The frequency distribution of dung circumference classes of the observed elephants was similar to that of the&nbsp;dung-piles measured along the transects in 2008. Therefore, dung-piles measurements were used to estimate&nbsp;the Nazinga Game Ranch savanna elephant population’s age and sex structures at the end of dry seasons of&nbsp;2007 and 2008. We advocated that the Nazinga elephant population consisted mainly of sub-adults.4. The sex ratio was estimated to be in favour of females (1/2). The age-class-specific sex ratio was uneven&nbsp;for calves and young individuals, while being in favour of females with adults. Individuals of less than 1 year&nbsp;represented 6% of the population during the study period

Gas measurement methods for laboratory-scale anaerobic reactors

Erworben im Rahmen der Schweizer Nationallizenzen (http://www.nationallizenzen.ch)Various methods exist to measure gas production from anaerobic reactors but not all can easily be used to obtain the rate directly, and some are limited by small flow rates. A review of gas measurement methods is given. Two simple online gas monitoring systems, are described. The reactor design with respect to liquid overflow and gas take-off is shown to be important

Protection of biofilms against toxic shocks by the adsorption and desorption capacity of carriers in anaerobic fluidized bed reactors

Erworben im Rahmen der Schweizer Nationallizenzen (http://www.nationallizenzen.ch)The aim of this study was to select a support medium for an anaerobic biofilm fluidized bed reactor (AFBR) for waste water treatment. Six materials, shale, pumice, porous glass, quartz sand, activated carbon and anthracite were used as carriers for the biofilm. The reactors were operated in parallel for several months with vapour condensate from a sulfite cellulose process as feed. The criteria used for the evaluation were: a) Reproducibility of the reactor performance, b) performance of the different carriers under various loading rates, c) stability against toxic shock loadings using 2,4,6-trichlorophenol (TCP) as toxicant, d) recovery capacity after intoxication and starvation, e) adsorption/desorption behavior of the carriers. A comparison between four runs showed good reproducibility of the steady state removal rates. The performance of the reactors and the stability of the degradation rates were tested for a range of loading conditions. Unbuffered, buffered and pH controlled conditions were compared. The pumice carrier was best with respect to the degradation rate achieved per carrier mass. The response of the reactors to massive TCP step loadings was tested. Loadings less than 1.5 kg TCP/m3d resulted in initially normal gas production rates for all the systems, except the activated carbon, whose gas production was partially inhibited from the start. After increasing the load to 1.5 kg TCP/m3d the gas production rates of all the other reactors fell abruptly to zero. Restarting after 2 months, all reactors showed methanogenic activity without requiring new inoculum. Adsorption and desorption experiments with TCP showed that only the anthracite and activated carbon adsorbed appreciable amounts. The activated carbon had the greatest adsorption capacity but did not release the TCP by desorption, as did the anthracite. A bicomponent (pumice and anthracite) carrier mixture was compared in biological experiments with pumice and anthracite carrier alone, with and without TCP loading. The pumice and the carrier-mix performed equally well under non-toxic-loading conditions. With TCP toxic loading, the performance of the anthracite was superior. The anthracite carrier could be regenerated, owing mainly to its capacity for desorption

Phenol degradation in a three-phase biofilm fluidized sand bed reactor

«Erworben im Rahmen der Schweizer Nationallizenzen (http://www.nationallizenzen.ch)»A previous three phase fluidized sand bed reactor design was improved by adding a draft tube to improve fluidization and submerged effluent tubes for sand separation. The changes had little influence on the oxygen transfer coefficients(KL a), but greatly reduced the aeration rate required for sand suspension. The resulting 12.5 dm3 reactor was operated with 1 h liquid residence time, 10.2dm3/min aeration rate, and 1.7-2.3 kg sand (0.25-0.35 mm diameter) for the degradation of phenol as sole carbon source. The KLa of 0.015 s−1 gave more than adequate oxygen transfer to support rates of 180g phenol/h · m3 and 216 g oxygen/h · m3. The biomass-sand ratios of 20-35 mg volatiles/g gave estimated biomass concentrations of 3-6 g volatiles/dm3. Offline kinetic measurements showed weak inhibition kinetics with constants ofKs=0.2 mg phenol/dm3, Ko2=0.5 mg oxygen/dm3 and KinI= 122.5 mg phenol/dm3. Very small biofilm diffusion effects were observed. Dynamic experiments demonstrated rapid response of dissolved oxygen to phenol changes below the inhibition level. Experimentally simulated continuous stagewise operation required three stages, each with 1 h residence time, for complete degradation of 300 mg phenol/dm3 · h

Determining specific biomass activity in anaerobic wastewater treatment processes

«Erworben im Rahmen der Schweizer Nationallizenzen (http://www.nationallizenzen.ch)»An experimental method for the measurement of specific gas production rate was developed and tested with biomass samples taken from anaerobic fluidized bed reactors, operating with a variety of carriers with molasses, condensate from cellulose production and brewery wastewater as feeds. The method is based on reactor sampling and offline gas volume measurement during a known time interval. Important factors are biomass and liquid sampling under oxygen-free conditions, using the liquid from the reactor as substrate, providing sufficient mixing and maintaining the physical integrity of the biomass. The method was developed in such a way that small samples (20 ml) were taken under anaerobic conditions (poising agent) for short-term (2-3 min.) gas rate measurements in a small fluidized bed (25 ml) batch reactor with U-tube. Biomass content was measured by an instrumental nitrogen method (Dumas), followed by weight determination of the carrier. The gas rates measured with the test system, and their dependence on substrate concentration, were in good agreement with those directly measured from the continuous fluidized bed reactor. Additions of molasses and acetate to the sample proved that the influence of concentration on the biomass activity can be obtained only by operating the continuous reactor at the concentration levels of interest. Comparison between the reactors showed large differences in the specific activity and the total reactor activity. It was found when comparing two reactors, that the values of the specific and the total activities permitted the calculation of the relative biomass quantities. In this way the influence of the carrier-type could be evaluated