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Problems with the pulse‐jet bag filter operation have a direct influence on process plant operation and may result in loss of production time. Therefore, long‐term stable operation of the plant is desirable for both the manufacturers and operators. The effects of operating parameters are studied experimentally on filter operation with regeneration between the upper and lower pressure drop limits. Many combinations were identified when the filter operation derailed from stable to unstable operation on changing one of the operating parameters. Filtration velocity, pulse pressure, and the upper limit of pressure drop had the potential of creating instability. A threshold detachment overpressure existed below which the operation led to unstable conditions at a certain filtration velocity and which increased with increasing velocity.

The article discusses the structured approach for standardized specifications for the flavor industry. It presents the standardization of analytical, microbiological and sensorial test scopes on a global basis. A decision tree-based approach to globally standardized specifications for the flavor industry is also described. The approach for the specifications is based on the differentiation between flavoring raw materials and flavorings.

Der Abbau flüchtiger organischer Kohlenwasserstoffe aus Abgasen gelingt mittels heterogener Photokatalyse. Die Verwendung eines körnigen, transparenten, mit photokatalytisch aktiven Nanoteilchen aus TiO2beschichteten Materials erlaubt eine kompakte reaktionstechnische Umsetzung. Die transiente Simulation des Reaktors zeigt, dass eine optimale Konfiguration hinsichtlich geometrischer Abmessung und Bestrahlungsrichtung gegeben ist. Dabei spielen die Quervermischung des Gases und die Einstrahltiefe eine entscheidende Rolle.

Industrial precipitation processes often use chemical agents to influence crystal morphology and size distribution. This experimental study deals with the investigation of physical parameters including an alternative method to affect crystal growth, thus, avoiding the presence of additives as intrinsic impurities. The influence of shear stress acting on growing crystals within a droplet is investigated in an ultrasound levitator. An ultrasound levitator enables the suspension of a single droplet against gravity and the study of containerless precipitation with specific mechanical forces acting on crystals. The levitator is used as a three‐phase reactor with precipitation from the gas and liquid, and as a reactor for precipitation from two different solutions. Calcium carbonate is used as a model system. The variation of temperature and the amount of applied shear stress leads to different amounts of calcium carbonate morphologies. An increase in the shear stress results in more rounded or spherical crystals. The intensity of the shear stress also influences the particle size distributions of the precipitated crystals, i.e., with increasing shear stress, particle size distributions are shifted to smaller sizes.

No abstracts.

Lumiracoxib is a cyclooxygenase-2 selective inhibitor in development for the treatment of osteoarthritis (OA), rheumatoid arthritis and acute pain. We reviewed nine clinical studies of 1 − 52 weeks' duration demonstrating the efficacy of lumiracoxib in OA. Male and female patients aged ≥ 18 years with primary OA of the hand, hip or knee received lumiracoxib, placebo or active comparators (diclofenac, celecoxib or rofecoxib). Lumiracoxib provided consistent reductions in OA pain intensity and improvements in the patient's global assessment of disease activity and functional status (assessed using the Western Ontario and McMaster Universities Osteoarthritis Index questionnaire or the Australian/Canadian OA Hand Index). These results were superior to placebo and similar to the active comparators tested. In addition, lumiracoxib was consistently superior to placebo and generally similar to active comparators in terms of the new Outcome Measures in Clinical Trials and Osteoarthritis Research Society International criteria. These were used to provide a single measure of response to treatment, taking into account pain, the patient's global assessment of disease activity and functional status.

No abstract.

Studies high-power liquid chromatography-nuclear magnetic resonance as a tool for the identification of non-volatiles in lemon peel oils. Use of the technique for the analysis of pharmaceuticals, drug metabolites and polymers; Modes of operation; Chromatographic analysis of the residue carried out under reversed phase conditions.

This article reports on the interfacial behavior of large liquid-phase polycyclic aromatic hydrocarbons in pitches that are common precursors to carbon materials. Experiments were conducted to identify preferred angles of molecular orientation (“surface anchoring” states) and to measure contact angles on a variety of well-characterized substrates. The results show that the large disklike polyaromatic molecules exhibit anomalously weak noncovalent interactions with a variety of surfaces, a fact that we attribute to inhibition of dispersion forces due to geometric mismatch at the interface. It is further found that large polyaromatics prefer edge-on molecular orientation at most interfaces, a configuration that preserves internal aromatic π−π bonds at the expense of inhibited π−surface bonds. A theory of π−π bond preservation is proposed to explain many aspects of wetting, adsorption, anchoring, and supramolecular assembly in this important class of compounds, including the formation mechanism for the classic bipolar Brooks−Taylor mesocarbon spheres. The results are used to discuss the mechanisms of structure selection in carbon materials prepared at high and low temperatures. The results are also used to demonstrate a new approach for molecular engineering of carbon that employs anchoring templates to synthesize new materials with preprogrammed patterns of graphene layer orientation.

Jet-pulsed filters are frequently used to separate fine solid particles from gas streams. An example for the application of the filter as both a solid separator and a fixed-bed reactor is a dry flue gas cleaning process, where the dry solid sorbent Ca(OH)2 forms a filter cake that captures a major part of the SO2 and HCl out of the flue gas. One important phenomenon concerning the formation of the filter cake on jet-pulsed filters is imperfect cake removal. Here a jet pulse tears off the entire filter cake from only a fraction of the exposed filter area, and only part of the total filter area is subjected to the jet-pulse cleaning. This property of jet-pulsed filters has a great influence on the chemical reaction simulation between gas and solid in the filter cake because the gas velocity through the cake, the cake thickness, and the residence time distribution of the solid forming the cake differ widely over the entire filter area. A recently developed filter model, in which different classes of cake thicknesses are understood to result from different cake generations, is used to determine the distributions of cake thickness, gas velocity, and residence time of the solid over the filter area. With the combination of the filter model and a fixed-bed reaction model using an empirical kinetic equation, the SO2 removal in the fixed bed of the filter cake can be simulated. The combined filter and reaction model was successfully validated with an experiment from a pilot plant for dry flue gas cleaning, where solid Ca(OH)2 was used as a sorbent. A sample of the partially reacted sorbent from the pilot plant had been used to derive the empirical kinetic equation for SO2 sorption in fixed-bed laboratory experiments.

No abstracts.

There are different non‐idealities related to cloth filters, which are cleaned by jet pulses. The well‐known phenomenon of cake compaction causes progressive curves of the pressure drop versus time. Some experiments show degressive shapes of the pressure drop, though. It will be shown, that this behavior can be explained by dividing the filter in segments. Each model segment can have a different cake thickness, whereas the pressure drop of every single segment is the same at any time during filtration. The capacity of this model is pointed out to determine the cake load on existing filters and to simulate unknown operating points.

Lime is widely utilized as a sorbent in dry and semidry sulfur removal processes. In this study limestone was calcined at high temperature and lime was produced by water vapor steam treatment at low temperature. Experiments were performed at conditions that also cover those usually present in coal-fired power plants. The investigation of the reaction of lime with synthetic flue gas showed that the relative humidity of the gas has a major impact on the reactivity. Also the presence of oxygen and/or carbon dioxide does not show a significant influence on the sulfur dioxide removal reaction though some intermediate formation of calcium carbonate cannot be excluded. Mainly calcium sulfite hemihydrate was found to be the reaction product, but some calcium sulfate hemihydrate was also formed when oxygen was present. Four regions with different prevailing reaction mechanisms can be defined:  In the beginning the formation of a monolayer is mainly determined by the SO2 concentration and to some smaller extent also by the relative humidity. This period is followed by the formation of the consecutive product layers which can initially be determined by a dissolving process of SO2. Afterward this formation is only determined by the relative humidity and most likely by product layer diffusion. Above a conversion of around 9% reaction rate drops significantly which can be due to pore closure.

No abstract.