METHODS OF USING MATH CASES (PROBLEM SITUATION) IN PRIMARY EDUCATION

The article is about Keys and provides information on how to use Mathematical Cases in Elementary Education

Methods Of Using Math Cases (Problem Situation) In Primary Education

The article is about Keys and provides information on how to use Mathematical Cases in Elementary Education

The genus Hyalomma Koch, 1844. X. Redescription of all parasitic stages of H. (Euhyalomma) scupense Schulze, 1919 (= H. detritum Schulze) (Acari: Ixodidae) and notes on its biology

Taxonomic uncertainty as to the identities of Hyalomma (Euhyalomma) scupense Schulze, 1919 and Hyalomma detritum Schulze, 1919 has existed for nearly 85 years. The chief criterion used to consider these taxa as separate species has been an ecological feature, namely that H. scupense is a one-host tick while H. detritum is a two-host species. Morphologically they are identical. To date no comprehensive taxonomic study has been done on all parasitic stages of the two species. Here the decision to grant priority status to H. scupense and to synonymise H. detritum with H. scupense is defended. The adults and immature stages of H. scupense are illustrated and redescribed. The morphological characteristics that separate the males, females, nymphs and larvae from those of other Hyalomma species are discussed for each developmental stage. Data on hosts, geographic distribution and disease relationships are provided.http://www.paru.cas.cz/folia

Chemical speciation of environmentally significant metals with inorganic ligands. Part 4: The Cd2+ + OH–, Cl–, CO32–, SO42–, and PO43– systems (IUPAC Technical Report)

The numerical modeling of Cd-II speciation amongst the environmental inorganic ligands Cl-, OH-, CO32-, SO42-, and PO43- requires reliable values for the relevant stability (formation) constants. This paper compiles and provides a critical review of these constants and related thermodynamic data. It recommends values of log(10) beta(p,q,r) valid at I-m = 0 mol kg(-1) and 25 degrees C (298.15 K), along with the equations and empirical reaction ion interaction coefficients, Delta epsilon, required to calculate log(10)beta(p),(,q,r) values at higher ionic strengths using the Bronsted-Guggenheim-Scatchard specific ion interaction theory (SIT). Values for the corresponding reaction enthalpies, Delta H-r, are reported where available. Unfortunately, with the exception of the Cd-II-chlorido system and (at low ionic strengths) the Cd-II-sulfato system, the equilibrium reactions for the title systems are relatively poorly characterized. In weakly acidic fresh water systems (-log(10){[H+]/c degrees} < 6), in the absence of organic ligands (e. g., humic substances), Cd-II speciation is dominated by Cd2+(aq), with CdSO4(aq) as a minor species. In this respect, Cd-II is similar to Cu-II [2007PBa] and Pb-II [2009PBa]. However, in weakly alkaline fresh water solutions, 7.5 < -log(10) {[H+]/c degrees} < 8.6, the speciation of Cd-II is still dominated by Cd2+(aq), whereas for Cu-II [2007PBa] and Pb-II [2009PBa] the carbonato-species MCO3(aq) dominates. In weakly acidic saline systems (-log(10) {[H+]/c degrees} < 6; -log(10) {[Cl-]/c degrees} < 2.0) the speciation is dominated by CdCln(2-n)+ complexes, (n = 1-3), with Cd2+(aq) as a minor species. This is qualitatively similar to the situation for Cu-II and Pb-II. However, in weakly alkaline saline solutions, including seawater, the chlorido-complexes still dominate the speciation of Cd-II because of the relatively low stability of CdCO3(aq). In contrast, the speciation of Cu-II [2007PBa] and Pb-II [2009PBa] in seawater is dominated by the respective species MCO3(aq). There is scope for additional high-quality measurements in the Cd2+ + H+ + CO32- system as the large uncertainties in the stability constants for the Cd2+-carbonato complexes significantly affect the speciation calculations