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A new technique to determine rate constants for growth and agglomeration with size- and time-dependent nuclei formation

Fluidized bed spray agglomeration is a particle size enlargement process where particles stick together with the help of spraying binder. High impact forces between particles lead to attrition. Attrition may be modeled as poly-disperse nucleation. Furthermore, particulate event like over-spray leads to the formation of particles in a wide range of volume. A new technique for the determination of agglomeration, growth and nucleation parameters is presented in this work. The model is based on a previous approach which takes mono disperse nuclei formation in the smallest class into account. Frequently in crystallization processes, nucleation is assumed to be mono-disperse. The technique presented here incorporates nuclei formation in a certain range of volume. It is quite general and applicable to consider size- and time-dependent nuclei formation. For two particular cases of growth and agglomeration including size-dependent nuclei formation, simulation data was generated by continuous feeding of nuclei in a certain range to demonstrate the capability of parameter extraction of the model. Further, the new technique is applied to extract rate constants from experimental data measured during fluidized bed spray agglomeration. This technique is also useful for the prediction of bimodal behavior of particle size distributions (PSD).     

Immune Cells Invade the Collateral Circulation during Human Stroke: Prospective Replication and Extension

It remains unclear if principal components of the local cerebral stroke immune response can be reliably and reproducibly observed in patients with acute large-vessel-occlusion (LVO) stroke. We prospectively studied a large independent cohort of n = 318 consecutive LVO stroke patients undergoing mechanical thrombectomy during which cerebral blood samples from within the occluded anterior circulation and systemic control samples from the ipsilateral cervical internal carotid artery were obtained. An extensive protocol was applied to homogenize the patient cohort and to standardize the procedural steps of endovascular sample collection, sample processing, and laboratory analyses. N = 58 patients met all inclusion criteria. (1) Mean total leukocyte counts were significantly higher within the occluded ischemic cerebral vasculature (I) vs. intraindividual systemic controls (S): +9.6%, I: 8114/µL ± 529 vs. S: 7406/µL ± 468, p = 0.0125. (2) This increase was driven by neutrophils: +12.1%, I: 7197/µL ± 510 vs. S: 6420/µL ± 438, p = 0.0022. Leukocyte influx was associated with (3) reduced retrograde collateral flow (R² = 0.09696, p = 0.0373) and (4) greater infarct extent (R² = 0.08382, p = 0.032). Despite LVO, leukocytes invade the occluded territory via retrograde collateral pathways early during ischemia, likely compromising cerebral hemodynamics and tissue integrity. This inflammatory response can be reliably observed in human stroke by harvesting immune cells from the occluded cerebral vascular compartment.     

Mechanical reliability of Ce0.8Gd0.2O2−δ-FeCo2O4 dual phase membranes synthesized by one-step solid-state reaction

Ce_0.8Gd_0.2O_2−δ-FeCo₂O₄ composites are attractive candidate materials for high-purity oxygen generation providing robust chemical stability. Aiming for future industrial applications, a feasible solid-state reaction process with one thermal processing step was used to synthesize 50 wt% Ce_0.8Gd_0.2O_2−δ:50 wt% FeCo₂O₄ and 85 wt% Ce_0.8Gd_0.2O_2−δ:15 wt% FeCo₂O₄ composites. Mechanical reliabilities of the sintered membranes were assessed based on the characterized mechanical properties and subcritical crack growth behavior. In general, the fracture strengths of as-sintered membranes were reduced by tensile residual stresses and microcracks. In particular, the enhanced subcritical crack growth behavior, which leads to limited stress tolerance and high failure probability after a 10-year operation, was evaluated in more detail. Further materials and processing improvements are needed to eliminate the tensile stress and microcracks to warrant a long-term reliable operation of the composites.     

An analytical solution of population balance equations for continuous fluidized bed drying

Continuous fluidized bed drying is widely used to remove moisture or solvents from granular materials. It is known that different residence times of the wet particles may lead to a distribution of product properties, e.g. different moistures. The prediction of such moisture distributions in fluidized bed dryers is of particular interest in industrial practice. In the present study, a simple analytical approach is introduced to calculate moisture distributions at the outlet of a continuous fluidized bed dryer. The model provides an analytical solution of the simple one-dimensional population balances. It will be contrasted with a traditional model approach based on averages and with experimental investigations conducted in a lab scale fluidized bed dryer under variation of the particle and the gas flow rate. Furthermore, the moisture distributions of the dried product were estimated by single particle measurements using nuclear magnetic resonance spectroscopy. It will be demonstrated that the developed analytical approach is capable to predict such moisture distributions for continuous drying processes.     

Caterpillar Footprints as Host Location Kairomones for <Emphasis Type="Italic">Cotesia marginiventris</Emphasis>: Persistence and Chemical Nature

Herbivores walking over the epicuticular wax layer of a plant may leave tracks that disclose their presence to hunting predators or parasitoids. The braconid wasp Cotesia marginiventris is a solitary parasitoid of young noctuid caterpillars. It can locate potential hosts from a distance by orienting toward the scent of herbivore-damaged plants. Upon landing on the caterpillars’ food plant, the female parasitoid searches for further cues (kairomones) that confirm the presence of a suitable host. In a previous study, we showed that C. marginiventris recognizes the chemical footprints of absent Spodoptera frugiperda caterpillars on a leaf. Here, we report on the persistence and chemical nature of this host location kairomone. In a series of behavioral assays, we confirmed that caterpillars of S. frugiperda leave chemical tracks that elicit characteristic antennation behavior in C. marginiventris for up to 2 days. Both hexane extracts of caterpillar footprints and of the larvae’s ventral cuticle induced antennation and contained almost identical long-chain hydrocarbons, thus suggesting the prolegs and claspers as the kairomones’ main source. A series of linear C₂₁ to C₃₂ alkanes accounted for ca 90% of all identified compounds. Female wasps showed significant antennation responses on leaves treated with a reconstructed blend of these n-alkanes. However, wasp responses were relatively weak. Therefore, we presume that minor compounds, such as monomethyl-branched alkanes, which were also found, may contribute additionally to host recognition.     

Structure‐Based Optimization of Aldose Reductase Inhibitors Originating from Virtual Screening

Virtual screening discovered two prospective hits as potential leads for aldose reductase inhibition. Based on their crystal structures with the enzyme, a systematic optimization has been performed to reveal a first structure–activity relationship. A central thiophen moiety and a terminal nitro group exhibit the best binding properties.

     

Investigation of rhombohedral-cubic phase transition of La0.58Sr0.4Co0.2Fe0.8O3-δ using high temperature XRD

The phase transition of the La_0.58Sr_0.4Co_0.2Fe_0.8O_3-δ oxygen transport membrane material has been investigated by X-ray diffraction at elevated temperatures. It has a rhombohedral symmetry at room temperature that transforms to a cubic symmetry at operation relevant higher temperatures, which was investigated in detail in the current work on the basis of bar type and powder specimens and discussed in terms of correlations with mechanical behavior.     

WoLMIS: a labor market intelligence system for classifying web job vacancies

In the last decades, an increasing number of employers and job seekers have been relying on Web resources to get in touch and to find a job. If appropriately retrieved and analyzed, the huge number of job vacancies available today on on-line job portals can provide detailed and valuable information about the Web Labor Market dynamics and trends. In particular, this information can be useful to all actors, public and private, who play a role in the European Labor Market. This paper presents WoLMIS, a system aimed at collecting and automatically classifying multilingual Web job vacancies with respect to a standard taxonomy of occupations. The proposed system has been developed for the Cedefop European agency, which supports the development of European Vocational Education and Training (VET) policies and contributes to their implementation. In particular, WoLMIS allows analysts and Labor Market specialists to make sense of Labor Market dynamics and trends of several countries in Europe, by overcoming linguistic boundaries across national borders. A detailed experimental evaluation analysis is also provided for a set of about 2 million job vacancies, collected from a set of UK and Irish Web job sites from June to September 2015.     

simpA: An agent-oriented approach for programming concurrent applications on top of Java

More and more aspects of concurrency and concurrent programming are becoming part of mainstream programming and software engineering, due to several factors such as the widespread availability of multi-core/parallel architectures and Internet-based systems. This leads to the extension of mainstream object-oriented programming languages and platforms-Java is a main example-with libraries providing fine-grained mechanisms and idioms to support concurrent programming, in particular for building efficient programs. Besides this fine-grained support, a main research goal in this context is to devise higher-level, coarse-grained abstractions that would help building concurrent programs, as pure object-oriented abstractions help building large component-based programs. To this end, in this paper we present simpA, a Java-based framework that provides programmers with agent-oriented abstractions on top of the basic OO layer, as a means to organize and structure concurrent applications. We first describe the application programming interface (API) and annotation framework provided to Java programmers for building simpA applications, and then we discuss the main features of the approach from a software engineering point of view, by showing some programming examples. Finally, we define an operational semantics formalizing the main aspects of this programming model.