The Drying of Pyridine Hydrobromide

1 INTRODUCTIONThe drying of fine chemicals and pharmaceuticals is dominated by a number of special factorscompared to the drying of bulk chemicals.These include:very high value of product;lowthroughputs(typically,100 kg·h~(-1));materials that frequently possess toxic properties andare often sticky,pasty and difficult to handle when wet;the moisture to be evaporated ofteninvolves solvents;and multipurpose processing plants.     

Design methodology for fully dynamic-controlled polynomial profiles and reduced tracking error in CNC machines

High speed and high precision on computer numerically controlled (CNC) machines are major issues for most industrial automation processes. Among the most important factors for precise motion control are the control law, the controller implementation, and the profile reference. The effects of the control law and controller implementation on the tracking error in CNC machines have been widely studied, while the issue of profile reference has not received the required attention. To improve the dynamics provided by the conventional profile reference, several techniques have been proposed, focusing on peak jerk limitation. The novelty of this work is to develop a generalized methodology designed for producing dynamically constrained higher degree piecewise polynomial profiles, without limits in maximum polynomial degrees. They lead to define in an arbitrary way the dynamics shape, while the peak dynamics values constrained are maintained in order to improve the tracking error on CNC systems and giving the possibility to design fully dynamic-controlled trajectories. For experimentation purposes, a two-axis proportional–integral–derivative controller and profile reference generator are implemented in a low-cost field programmable gate array. The experimentation demonstrates the efficiency of the proposed methodology, showing the peak jerk and tracking error reduction, compared against recent reports from literature.     

Rising sludge in secondary settlers due to denitrification

High suspended solids concentrations in settler effluents can be caused by rising sludge, which is the effect of flotation of solids by nitrogen gas resulting from biological denitrification. Many factors influence the nitrogen gas bubble evolution. The most important factor is the rate of biological denitrification. Factors like nitrogen gas solubility and oxygen concentration in settler influent only play a minor role. The hydraulic retention time in the bottom part of the settler is, for all practical purposes, so high that sufficient nitrogen gas will be generated at temperatures above 20°C, if the nitrate content in the influent to the settler is above the critical one. For temperatures around 20°C the critical nitrate-nitrogen concentration is 6–8 g NO₃⁻-N/m³. The best measure in order to avoid rising sludge is to denitrify the wastewater in the treatment process ahead of the settler.     

State-Model Based Time-Domain Diagnosis of Internal Faults for Permanent Magnet Synchronous Machine Wind Application

Upon occurrence of an internal fault on the PMSM （permanent magnet synchronous machine）, the topology of the stator is amended causing structural imbalances due to the change of the connection within the windings. In this work, a state model of internal faults of the PMSM is developed. This model is in the （abc） reference frame. The modeling approach is based on the assumption that each stator phase is replaced by two major and minor sub-windings. This model is used subsequently in the residual generation for diagnosis. The fault indicators are obtained by the projection in parity space and estimated using the Luenberger observer. A scenario of fault inter-turn by the short-circuit occurring between phase （a and b） is validated by simulation.     

Biodegradation and product identification of [14C]hexabromocyclododecane in wastewater sludge and freshwater aquatic sediment

In a previous study the biodegradation of hexabromocyclododecane (HBCD) was reported to occur under realistic environmental concentrations in soils and freshwater aquatic sediments with biotransformation half-lives ranging from approximately 2 days to 2 months. In this study we extend our knowledge as to the environmental behavior of HBCD with respect to the fate of the three major diastereomers of HBCD (alpha, beta, and gamma) as well as to the identification of major intermediate metabolites formed during degradation. Substantial biological transformation of the alpha-, beta-, and gamma-[14C]HBCD diastereomers was observed in wastewater (i.e., digester) sludge and in freshwater aquatic sediment microcosms prepared under aerobic and anaerobic conditions. Concomitant with the loss of [14C]HBCD in these matrixes there was a concurrent production of three [14C]products. Using a combination of high performance liquid chromatography atmospheric pressure photoionization mass spectrometry and gas chromatography electron impact ionization mass spectrometry these metabolites were identified as tetrabromocyclododecene, dibromocyclododecadiene, and cyclododecatriene. We propose that HBCD is sequentially debrominated via dihaloelimination where at each step there is the loss of two bromines from vicinal carbons with the subsequent formation of a double bond between the adjacent carbon atoms. These results demonstrate that microorganisms naturally occurring in aquatic sediments and anaerobic digester sludge mediate complete debromination of HBCD.     

Potassium Lactate and Fresh-Pork-Sausage Formulation Effects on Shelf Life in Lighted and Unlighted Display

ABSTRACT:  The objective was to examine the effects of potassium lactate (KL) and raw-meat blend on the shelf-life of fresh-pork-sausage patties in lighted and unlighted display. Four fresh-pork-sausage blends (70% prerigor meat, 30% fresh-pork trim; 80%/20%; 90%/10%; and 100%/0%) were formulated ( n = 3) with 0% and 3% KL, and patties were displayed for 10 d at 4 °C in lighted display or for 7 d in unlighted display followed by 3 d in lighted display. Patties with KL had lower aerobic plate counts (APC), more stable color (greater a* and chroma, less visual discoloration), and less lipid oxidation ( P < 0.05) during display than did patties without KL. Patties in the light for 10 d were more discolored and had more lipid oxidation ( P < 0.05) than those in the dark for 7 d followed by the light for 3 d. Patties with KL in the light for 10 d had similar color ( P > 0.05) to patties without KL that were in the dark for the first 7 d. Adding KL resulted in similar color stability ( P > 0.05) among patties made from 80, 90, and 100% prerigor meat and greater color stability ( P < 0.05) than similarly formulated patties without KL. By using 3% KL, fresh-pork-sausage patty color stability was maximized, APC and lipid oxidation were minimized, and formulation costs can be decreased by using less-expensive fresh-pork trim for up to 20% of the blend. Adding KL also minimized the effects of display lighting on myoglobin and lipid oxidation.     

Mg-doped LiNi0.5Mn1.5O4 spinel for cathode materials

Lithium-ion batteries are becoming more and more important not only for portable electronic devices, but also in prevision of high power electric vehicles. In such an optic, deep studies regarding all the components of a secondary battery are in development. In this study, high voltage cathode materials have been selected. Crystals with spinel structure have a 3D vacancy pathway suitable for Li-ions transport. The material under study was LiNi_0.5Mn_1.5O₄ doped with magnesium replacing the nickel. Various samples were synthesized via three different routes: a solid-state method, a modified sol–gel method and a xerogel method. The structure and morphology of the powders were analyzed with HRTEM and XRD. Electrochemical tests were also performed. A wide range of particle sizes (from micro to nanosize) was the result of the different synthesis routes. Unfortunately pure materials were not always obtained. The electrochemical tests showed improvement of the material's cyclability, by reducing the particle size. The electrochemical tests further confirmed the existence of a Li_1+dMn_2−dO₄ impurity. The results are quite promising, however, further improvement of the purity of the electrode composition are needed.     

Hydrolysis of intralipid by pancreatic lipase and phospholipase A2-gel filtration studies

Intralipid was incubated with pancreatic lipase (EC 3.1.1.3) and/or phospholipase A₂ (EC 3.1.1.4) at two bile salts/phosphatidylcholine molar ratios and at two different triglyceride hydrolysis rates using various amounts of lipase. Incubations were studied by gel filtration. Results show: (i) During lipase action, three phases of lipids coexist: an emulsified phase, a micellar phase and an intermediate heavy phase sized between the two others. The equilibrium between each phase is dependent upon the bile salts concentration. (ii) Under these conditions, pancreatic lipase was at 60% bound to the emulsified phase, whereas pancreatic phospholipase A₂ was bound at 94% to the micellar phase.