Adsorptive removal of methylene blue from aqueous solution on activated carbon prepared from Malawian baobab fruit shell wastes: Equilibrium,kinetics and thermodynamic studies

Baobab fruit shell (BFS), a renewable bio-waste from Malawian baobab tree was used as a precursor for the production of a low-cost activated carbon to remove methylene blue (MB) from aqueous solution. Parameters such as contact time, initial methylene blue concentration, adsorbent dose and temperature were studied. The adsorption process can be well described by both Langmuir isotherm and the pseudo-second-order kinetics. The maximum monolayer adsorption capacity of MB dye was ca. 334.45 mg/g. The negative value of the Gibb’s free energy and positive value of adsorption enthalpy showed the spontaneous nature and endothermic nature of the adsorption process, respectively.     

Comparison of Corrosion Resistance Properties of Electrophoretically Deposited MoS2 and WS2 Nanosheets Coatings on Mild Steel

Metallurgical and Materials Transactions A - The present work compares the corrosion resistance properties of electrophoretically deposited MoS2 and WS2 nanosheets coatings on mild steel....     

Genetic and environmental analysis of diseases with major economic impact in Israeli Holsteins

Incidences of ketosis, metritis, mastitis, and retained placenta were studied in Israeli Holstein cows calving between 2008 and 2017. These diseases were selected based on their economic impact. Ketosis, metritis, and retained placenta were scored dichotomously. Mastitis was scored as absent, a single occurrence during the lactation, or more than 1 occurrence. Ketosis and metritis were recorded during the first 21 d after calving, retained placenta during the first 5 d after calving, and mastitis up to 305 d in milk. The effects of herd-year-season, calving age, month of calving, gestation length, and occurrence of dystocia were included in the first-parity analysis models. All effects were significant for metritis and retained placenta. For ketosis, all effects were significant, except for gestation length. For mastitis, only the effects of herd-year-season and calving age were significant. Variance components were computed by the multitrait animal model. The 4 diseases were analyzed jointly based on first-parity records, and each disease was analyzed separately for parities 1 to 3 with the different parities considered separate traits. The 4 disease traits in first parity were also analyzed jointly with the 6 major traits included in the Israeli breeding index: milk, fat, and protein production; somatic cell score; female fertility; and longevity. Heritability was highest for metritis and lowest for mastitis, but all heritabilities were <0.07, similar to previous studies. For all 4 diseases, genetic correlations among the first 3 parities were >0.65, and all residual correlations were <0.07. Selection of herd-years assumed to have more accurate recording of mastitis did not result in higher heritability estimates. Genetic correlations between the disease traits and milk, fat, and protein production were economically unfavorable, while correlations between the disease traits and somatic cell score, female fertility, and longevity were economically favorable. Expected genetic changes in the disease traits after 10 yr of selection with the current Israeli breeding index were all <1%, except for ketosis, which was predicted to increase by 1.5%. Inclusion of these traits in a proposed index with the disease traits constituting 7% of the index would result in only marginal improvements for the disease traits and adversely affect genetic gain for fat and protein production. Thus, inclusion of these traits in the breeding index cannot be justified economically.     

Ontologies on trial: the lesson of Maurice v. Judd (New York, 1818)

Ontologies, and legal ontologies are a particular class of application of these, have become fairly popular. Are they fit for purpose? Like with all kinds of tools from legal computing, one must be cautious, and consider very attentively what the likely receptions are going to be, among users. Maurice v. Judd (New York, 1818), when a jury was called to decide whether whale oil is fish oil, and decided that indeed whales are fish, is a trial that was analysed in Graham Burnett's Trying Leviathan: The nineteenth-century New York court case that put the whale on trial and challenged the order of nature (Princeton, NJ: Princeton University). It is a highly readable book, and it has something important to teach developers of ontologies in the legal domain. The intended public of users of any software, or of ontologies in particular, is paramount. Those intended users you are catering to with your new tool are going to make or break it, just as it happened, e.g. to sentencing information systems in Canadian provinces.     

Geometric Factors in the Processing of Fine Fiber by Fluid Shear and Heat Transfer

In this article, a synergistic approach encompassing numerical simulation and laboratory experimentation is used to identify the optimal geometry for the creation of fine fiber by the melt-blown process. The problem involves highly complex fluid flow and convective heat transfer. The fine fiber is created by the use of high-velocity, obliquely impinging air jets that stretch a polymer extrudate in the partially fluid state. High-temperature air is used to maintain the fluidity of the polymeric material as it exits the die. Four different geometrical configurations were investigated with regard to their capability of producing high fluid shear and high temperatures in the critical region just downstream of the emergence of the polymer extrudate from the tip of a die. The results of the numerical simulations provided a definitive conclusion about the relative efficacies of the four investigated geometrical configurations. The velocity and temperature profiles of the oblique jets were carefully documented to identify their decay with increasing downstream distance from the die tip. Velocity profile measurements were in excellent agreement with the numerical predictions, thereby validating the simulation model. Another major parameter of the study, in addition to the geometric-configuration issue, was the pressure difference responsible for setting the magnitude of the jet velocity. The accuracy of the results was established by a mesh independence study and by varying the size of the solution domain.     

Amplitude modulated instability in reactants plenum of a rotating detonation combustor

The pronounced interest in rotating detonation combustors (RDC) in recent years has witnessed the investigation of multiple facets of the combustor, like reactants, injection schemes and combustor geometry. The issue of instabilities in RDCs is a nascent field, and requires both the identification, and the subsequent explanation of different instability mechanisms. In particular, we are concerned with the low frequency instability exhibited by the detonation wave. This is attributed to two different types of low frequency instabilities—amplitude and frequency modulated—that are discovered in the air plenum of an RDC, and subsequently discussed. The occurrence of these instabilities is observed to depend on the fuel injection scheme used and the air flow rates through the combustor. The amplitude modulated instability in the air inlet is spatially varying, and rotates in a direction opposite to the direction of the detonation wave. At higher air flow rates, and thus higher pressure ratios across the air injection, this instability disappears. A preliminary hypothesis is proposed to explain this amplitude modulation.     

Calcination of limestone in a tubular reactor

Theoretical expressions were developed for the design of a tubular reactor for the calcination of limestone, pneumatically conveyed by flue gas. The total residence time and the length of the reactor are affected in particular by the particle size, the excess thermal capacity of the gas and the heat transfer coefficient. High throughput can be achieved in relatively small reactors. An experimental investigation verified a theoretical prediction, that a considerable part of the decomposition takes place in the first few centimeters of the reactor length. The rate of heat transfer in this section was high, with Nusselt numbers of 9.9 to 31.7.