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Abstract: The objective of this study was to demonstrate the potential utilization of fly ash (FA), wood ash (WA), and metakaolin (MK) in developing new alkali-activated materials (AAMs) for the removal of cadmium ions from waste water. The synthesis of AAMs involved the dissolution of solid precursors, FA, WA, and MK, by a liquid activator (Na2SiO3 and NaOH). In concentrated solutions of the activator, the formation of an aluminosilicate gel structure occurred. DRIFT spectroscopy of the AAMs indicated main vibration bands between 1036 cm−1 and 996 cm−1, corresponding to Si-O-Si/Si-O-Al bands. Shifting vibration bands were seen at 1028 cm−1 to 1021 cm−1, indicating that the Si-O-Si/Si-O-Al bond is elongating, and the bond angle is decreasing. Based on the X-ray diffraction results, alkali-activated samples consist of an amorphous phase and residual mineral phases. The characteristic “hump” of an amorphous phase in the range from 20 to 40◦ 2θ was observed in FA and in all AWAFA samples. By the XRD patterns of the AAMs obtained by the activation of a solid three-component system, a new crystalline phase, gehlenite, was identified. The efficiency of AAMs in removing cadmium ions from aqueous solutions was tested under various conditions. The highest values of adsorption capacity, 64.76 mg/g (AWAFA6), 67.02 mg/g (AWAFAMK6), and 72.84 mg/gmg/g (AWAMK6), were obtained for materials activated with a 6 M NaOH solution in the alkali activator. The Langmuir adsorption isotherm and pseudo-second kinetic order provided the best fit for all investigated AAMs.
Keywords: fly ash, metakaolin, wood ash, adsorption kinetics, cadmium (II)
Published in DiRROS: 23.05.2024; Views: 92; Downloads: 58
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Abstract: his paper presents new records and noteworthy data on the following taxa in SE Europe and adjacent regions: stonewort Chara intermedia, liverworts Fossombronia wondraczekii and Pseudomoerckia blyttii, mosses Hamatocaulis vernicosus and Hookeria lucens, monocots Gladiolus palustris, Neotinea tridentata, and Orchis militaris and dicots Cardamine serbica, Cardamine waldsteinii, Hieracium kotschyanum and Pilosella petraea are given within SE Europe and adjacent regions.
Keywords: new report, Cardamine serbica, Cardamine waldsteinii, Chara intermedia, Gladiolus palustris, Fossombronia wondraczekii, Hamatocaulis vernicosus, Hieracium kotschyanum, Hookeria lucens, Neotinea tridentata, Orchis militaris, Pilosella petraea, Pseudomoerckia blyttii, SE Europe
Published in DiRROS: 20.04.2022; Views: 577; Downloads: 425
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Abstract: Background: Prevalence of complement deficiencies (CDs) is markedly higher in Slovenian primary immunodeficiency (PID) registry in comparison to other national and international PID registries. Objective: The purposes of our study were to confirm CD and define complete and partial CD in registered patients in Slovenia, to evaluate frequency of clinical manifestations, and to assess the risk for characteristic infections separately for subjects with complete and partial CD. Methods: CD was confirmed with genetic analyses in patients with C2 deficiency, C8 deficiency, and hereditary angioedema or with repeated functional complement studies and measurement of complement components in other CD. Results of genetic studies (homozygous subjects vs. heterozygous carriers) and complement functional studies were analyzed to define complete (complement below the level of heterozygous carriers) and partial CD (complement above the level of homozygous patients). Presence of characteristic infections was assessed separately for complete and partial CD. Results: Genetic analyses confirmed markedly higher prevalence of CD in Slovenian PID registry (26% of all PID) than in other national and international PID registries (0.5–6% of all PID). Complement functional studies and complement component concentrations reliably distinguished between homozygous and heterozygous CD carriers. Subjects with partial CD had higher risk for characteristic infections than previously reported. Conclusion: Results of our study imply under-recognition of CD worldwide. Complement functional studies and complement component concentrations reliably predicted risk for characteristic infections in patients with complete or partial CD. Vaccination against encapsulated bacteria should be advocated also for subjects with partial CD and not limited to complete CD.
Keywords: complement deficiency, primary immunodeficiency, laboratory analysis, genetic analysis, clinical manifestations
Published in DiRROS: 12.11.2020; Views: 1412; Downloads: 604
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Keywords: wine aroma, leaf removal, varietal thiols, aroma compounds, hydroxycinnamates
Published in DiRROS: 11.05.2020; Views: 2276; Downloads: 1220
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Keywords: rak, življenjski slog, programi
Published in DiRROS: 02.04.2020; Views: 1193; Downloads: 317
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