Effect of propionic acid on kinetics of acetate and oleate and on plasma and milk fatty acid composition of goats

Entry rates of acetate and oleate and their incorporation into lipids of blood plasma and fatty acids of milk were studied in lactating goats fed a concentrate-roughage ration with propionic acid infused intraruminally at 0, 5.52, and 13.74 g/h by primed constant intravenous infusion of [1-carbon-14] acetate and [9, 10-hydrogen-3] oleate. Means for infusion rates were acetate, 60, 52, and 39 micrograms/ml blood plasma; propionate 9, 12, and 22 micrograms/ml; oleate, 19, 14, and 12 micrograms/ml; acetate entry rate, 3.9, 2.7, and 1.8 mmol/h per kg bodyweight; oleate entry rate, 47, 29, and 19 mumol/h per kg bodyweight; acetate oxidation rate, 2.0, 1.7, and 1.4 mmol/h per kg, and its contribution to the total carbon dioxide production, 16, 14, and 11%. Propionic acid increased incorporation of carbon-14 and hydrogen-3 into plasma lipids, elevated proportions of 7:0, 9:0, 11:0, 13:0, 15:0, and 17:0 fatty acids in milk, and tended to lower others. Specific radioactivities of milk fatty acids during infusion of propionic acid were elevated by 1.8 to 2.8 times, and total fatty acids in milk and plasma were lowered by 22 and 38%. Data support the glucogenic theory that propionic acid either directly or through gluconeogenesis stimulates insulin secretion, which in turn inhibits release of fatty acids from adipose tissue, resulting in milk fat depression.     

Experimental investigation on the combustion behaviour of pre-dried Greek lignite

The present paper includes the results of the combustion tests with Greek dried lignite performed at a 1 MWth semi industrial scale pulverized coal combustion facility. Scope of the campaign is the investigation of the combustion behaviour of Greek lignite, i.e. temperature fields, ignition, burnout, emissions, as well as slagging and fouling tendency, while firing with varying levels of recirculated flue gas. Dry coal co-firing conditions in a large scale boiler are simulated by adjusting the volume flow of recirculated flue gas.Two test series representing different boiler operation modes are performed. During the first series the maximum flue gas temperature increase, when co-firing dry coal, is determined, while in the second test series the needed load decrease, in order to keep constant furnace outlet temperature in dry coal co-firing conditions is recorded. A detailed measurement set is carried out including temperature profiles, emissions, fuel, fly ash sampling and slagging and fouling investigations through the installation of dedicated deposition probes.The anticipated increase of the furnace temperature profiles by decreasing the inserted recirculated flue gas is confirmed by the experimental results. No clear trend of dry coal co-combustion on the emissions' behaviour is noticed, while dry coal firing appears to have a moderate effect on the deposition behaviour of Greek lignite. These preliminary investigations indicate that no significant operational problems are expected during a potential future demonstration of dry lignite co-firing in a Greek large scale boiler.     

Reynolds stress and turbulence estimates in bottom boundary layer of Fall of Warness

A broadband acoustic Doppler current profiler (ADCP) moored on the seabed at 42 m depth has been used to observe the mean and turbulent flow components in the tidally energetic Fall of Warness channel over two tidal cycles. The Reynolds stress has been estimated from the difference in variance between the along-beam velocities of opposing acoustic beams. Near bed stress at 2.63 m above seabed (mab) exceeds 7.5 Pa at the time of mean flow (speed of ~ 1.3 m s^− 1) while the ebb stresses are limited to ~ 3.31 Pa during the peak ebb, mean, flow of ~ 1.3 m s^− 1. The production of turbulent kinetic energy (TKE), P was found to be negative below 2 × 10^− 9 W m^− 3 and up to 6 × 10^− 4 W m^− 3 was estimated during flood flows and decreasing to 3 × 10^− 4 W m^− 3. The TKE dissipation rate ε was estimated by inertial dissipation method (IDM) with the greatest value of 2.43 × 10^− 2 W m^− 3 observed near the seabed around maximum ebb, falling to 5.75 × 10^− 5 W m^− 3 around slack water. The comparison between P and ε was performed by calculating individual ratios of P corresponding to ε using a bootstrap resampling technique. The study shows that the ratio ε/P averaged over whole flood and ebb were found to be ~ 0.4138 and ~ 0.4177, respectively, indicating that production exceeded dissipation. The uncertainties in Reynolds stress estimates due to instrument noise were found to be 3 × 10^− 4 Pa while 4.52 × 10^− 2 Pa can be attributed to the uncertainties due to the increase in the flow-related component.     

Disaggregate energy consumption and industrial production in South Africa

This paper tries to assess the relationship between disaggregate energy consumption and industrial output in South Africa by undertaking a cointegration analysis using annual data from 1980 to 2005. We also investigate the causal relationships between the various disaggregate forms of energy consumption and industrial production. Our results imply that industrial production and employment are long-run forcing variables for electricity consumption. Applying the [Toda, H.Y., Yamamoto, T., 1995. Statistical inference in vector autoregressions with possibly integrated processes. Journal of Econometrics 66, 225–250] technique to Granger-causality, we find bi-directional causality between oil consumption and industrial production. For the other forms of energy consumption, there is evidence in support of the energy neutrality hypothesis. There is also evidence of causality between employment and electricity consumption as well as coal consumption causing employment.     

Characterization of metal hydrides using pneumato-chemical impedance spectroscopy

Pneumato-chemical impedance spectroscopy (PIS) is a tool derived from electrochemical impedance spectroscopy (EIS). PIS can be used to analyze the kinetics of various solid-gas reactions, such as the hydriding kinetics of metals in the presence of hysteresis. Pneumato-chemical impedance diagrams are obtained from simple gas transfer experiments, using non-harmonic pressure perturbations. In single-phase domains, the global sorption mechanism consists of mainly two steps, a surface chemisorption step and a bulk hydrogen transport step, controlled by diffusion. In two-phase domains, an additional phase transformation step must be considered. Model impedances are obtained by interconnecting microscopic impedances associated with each reaction step. By fitting model impedances to the experimental ones, microscopic rate parameters such as the surface dissociation resistance, the bulk hydrogen diffusion coefficient and the phase transformation resistance can be obtained. Different results obtained on palladium, palladium–silver and LaNi₅ samples (foils and powder) are presented to illustrate the potentialities of this spectroscopy.     

Co(II)(l-proline)2(H2O)2 solid complex: Characterization,magnetic properties,and DFT computations. Preliminary studies of its use as oxygen scavenger in packaging films

A solid Co^II complex with l-proline as ligand was synthesized and fully characterized using spectroscopic studies, magnetic data, and DFT calculations. Dioxygen scavenging properties were investigated by UV/Vis spectroscopy and oxymetry techniques. The Co-proline system presented very interesting properties in matter of oxygen absorption capacity both in solution and incorporated in a polymer matrix.     

Accumulation and quality of storage protein in developing cowpea,mung bean and soya bean seeds

This study was carried out to compare the time course of laying down seed storage protein in three legumes viz: cowpea (Vigna unquiculata), mung bean (Phaseolus aureus) and soya bean (Glycine max) planted in two replications. Pods were harvested periodically during seed maturation and studied for changes in fresh and dry weights, total sulphur, total nitrogen and protein content. At early stages of development crude protein formed about one-third of dry weight in the legumes but decreased to about one-quarter at maturity. The total sulphur which formed a substantial amount of the sulphur amino-acids in mature seeds did not change much in mung bean and cowpea but increased by about 24% from 20 to 69 days after flowering (DAF) in soya bean. Storage protein accumulation was very rapid between 10 and 14 DAF (10.4% day^?1) in mung bean, 7 and 14 DAF (12.9% day^?1) in cowpea and between 20 and 30 DAF (9.4 day^?1) in soya bean. Thereafter, protein accumulation declined slightly and gradually approached zero at time of seed maturity. The sulphur-to-nitrogen ratios gradually increased with maximum values in the mature seeds. Although seed protein content and quality (on S/N ratio basis) were highest in soya bean, accumulation of storage protein seemed to be faster in cowpea than mung bean and soya bean during seed maturation.     

Neutron Reflectometry Characterization of Interface Width between Sol-Gel Titanium Dioxide and Silicon Dioxide Thin Films

Neutron reflectometry (NR) was used to directly measure the interface width between a titanium dioxide and a silicon dioxide film deposited by sol-gel processing. In a bilayer heated to 450°C, NR measurements showed that the interface width is 0.8 nm. This width is the same as the roughness of a sol-gel silicon dioxide surface after the same heat treatment, suggesting no interdiffusion or mixing at the bilayer interface.