Invited review: Systematic review of diagnostic tests for reproductive-tract infection and inflammation in dairy cows

The objective of this study was to conduct a systematic and critical appraisal of the quality of previous publications and describe diagnostic methods, diagnostic criteria and definitions, repeatability, and agreement among methods for diagnosis of vaginitis, cervicitis, endometritis, salpingitis, and oophoritis in dairy cows. Publications (n = 1,600) that included the words “dairy,” “cows,” and at least one disease of interest were located with online search engines. In total, 51 papers were selected for comprehensive review by pairs of the authors. Only 61% (n = 31) of the 51 reviewed papers provided a definition or citation for the disease or diagnostic methods studied, and only 49% (n = 25) of the papers provided the data or a citation to support the test cut point used for diagnosing disease. Furthermore, a large proportion of the papers did not provide sufficient detail to allow critical assessment of the quality of design or reporting. Of 11 described diagnostic methods, only one complete methodology, i.e., vaginoscopy, was assessed for both within- and between-operator repeatability (κ = 0.55–0.60 and 0.44, respectively). In the absence of a gold standard, comparisons between different tests have been undertaken. Agreement between the various diagnostic methods is at a low level. These discrepancies may indicate that these diagnostic methods assess different aspects of reproductive health and underline the importance of tying diagnostic criteria to objective measures of reproductive performance. Those studies that used a reproductive outcome to select cut points and tests have the greatest clinical utility. This approach has demonstrated, for example, that presence of (muco)purulent discharge in the vagina and an increased proportion of leukocytes in cytological preparations following uterine lavage or cytobrush sampling are associated with poorer reproductive outcomes. The lack of validated, consistent definitions and outcome variables makes comparisons of the different tests difficult. The quality of design and reporting in future publications could be improved by using checklists as a guideline. Further high-quality research based on published standards to improve study design and reporting should improve cow-side diagnostic tests. Specifically, more data on intra- and interobserver agreement are needed to evaluate test variability. Also, more studies are necessary to determine optimal cut points and time postpartum of examination.     

Effect of fluid–particle-interactions on dispersing nano-particles in epoxy resins using stirred-media-mills and three-roll-mills

Fibre reinforced composites are indispensable in the field of modern lightweight structures, such as used in aerospace, automotive industry or in wind power plants. Those materials provide high weight savings and increase the efficiency of a structure significantly. Therefore, various efforts are made to continuously improve the quality of the matrix and the fibres. By embedding nano-particles into the epoxy matrix, the mechanical properties as well as the electrical and thermal characteristics can significantly be improved [1]. In most cases these nano-sized particles are produced as dry powders not as single primary particles but rather as particle collectives consisting out of several primary particles. For the application in reinforced composites the particles must be suspended in epoxy resin as separately dispersed primary particles or in a certain aggregate size. Generally, the influencing parameters to break up the aggregates in a dispersion process can be divided into the stress mechanism, the intensity and the frequency of the dispersing machine itself, the properties of the dispersed particles (e.g. the particle–particle interactions) the properties of the homogenous phase and the particle–resin-interactions. Besides the effect of the chosen dispersing machine the optimization of the dispersing process was investigated by applying modified particle surfaces and varying the fluid properties. The results show that the surface properties of the particles must fit to the epoxy resin properties and the attractive forces between the primary particles must be reduced or the stabilization improved, respectively. An indication for an improved stabilization and adjustment of the particles surface properties to the fluid properties can be obtained by measurements of the contact angle and the rheological properties. Generally, an increase of viscosity and mass fraction of the product leads to a higher energetic efficiency of the dispersion process in the stirred media mill and three-roll-mill.     

Particle exchange in horizontal two-compartment fluidized beds – CFD simulation and experimental validation

A series of ideally mixed fluidized beds is used to obtain a narrow product size distribution in industrial-scale applications. Thereby, the fluidized bed compartments or stages are divided from each other by weirs with defined openings (slots) for particle exchange. The knowledge of particle exchange streams and residence times in different compartments, respectively, is crucial for the process design and optimization of such processes. This particle exchange behavior between different compartments in 3D-fluidized bed systems cannot be easily evaluated by experiments.Hence, a CFD multiphase model is used here and applied to a horizontal two-compartment batch fluidized bed apparatus to obtain particle exchange streams as a function of process parameters, e.g. slot height and bed mass. Good comparison of numerical and experimental results shows that this model can reasonably predict the particle exchange in two-compartment fluidized bed processes.On the basis of this work, the validated and predictive multiphase model can be applied to continuous horizontal multi-compartment fluidized beds as a future perspective to identify best-case process parameters, e.g. optimal slot height.     

Partition Coefficients for Continuous Micellar Reaction Processes

The micelle‐water partition coefficients of reactants, products, and catalyst ligands are predicted using UNIFAC‐IF and COSMO‐RS. It is demonstrated that both models represent a reasonable tool for preliminary screening of the micellar systems for a specific continuous reaction process supported by micellar enhanced ultrafiltration (MEUF). The model reaction is the hydrogenation of itaconic acid and its derivatives (dialkyl esters) in the presence of a rhodium‐based catalyst. The effect of the size and nature of the surfactant head group and tail is explored for nonionic and ionic surfactants. The high partition coefficients of the catalyst ligands indicate that no catalyst leakage is expected in MEUF. Based on the concentration dependence of the calculated partition coefficients, the solubilization capacity of micelles is estimated.     

Ionic Liquids as Operating Fluids in High Pressure Applications

During the past years a growing number of scientists and engineers have investigated ionic liquids because of their outstanding advantages in several areas. Their unique physical properties and specific chemical behavior make these liquids very interesting for new and innovative applications. For commercial implementation ionic liquids have to meet a number of requirements. For use in high pressure applications they should have a low compressibility, an adjustable gas solubility and a superior lubricating ability. A screening of the relevant parameters was conducted in several experimental setups built for these purposes. Most of these parameters were also examined under long term conditions with regard to real process conditions and safety guarantee in possible high pressure applications. A major application is the compression of oxygen using ionic liquid as operating fluid. Besides, there are many more applications where the superior chemical and physical properties of ionic liquids are of high potential benefit.     

Ionic Liquids for Propene‐Propane Separation

This paper presents an extensive study on the feasibility of ionic liquids (IL) for the extractive distillation of propene‐propane mixtures. A new experimental method for express screening of non‐volatile entrainers was elaborated. A series of ILs and their mixtures were screened at ambient temperature and low pressures. The screening results show that every tested IL turns a low boiler propene into a high boiler and the alkene‐to‐alkane separation factor can be as low as 0.28. The solubility and separation efficiency can be tuned by adjusting the chemical structures of the ions forming the IL. It was found that shortening of the alkyl substituents of the imidazolium ions leads to a decrease in capacity and to an increase in the separation factor. Interestingly, ILs containing nitrile functionalities in either the cation or the anion showed, in our experiments, enhanced separation ability combined with still good capacities. From our thermodynamic measurements, [EMIM][[B(CN)₄] was proved to be the most promising candidate. Binary mixtures of ILs were also tested and resulted in separation factors and capacities between the values for the individual ILs. For the most promising candidates, also autoclave measurements at elevated temperatures and pressures were carried out. These experiments indicate that the separation ability decreases with growing temperature and loading. In general, our study definitely proves the high potential of ILs to act as entrainers in the extractive distillation of propene‐propane mixtures or for the separation of any other low‐boiling alkene‐alkane mixture.