Investigation of acrylonitrile polymerization on the surface of porous microspherical silica gel

The kinetics of acrylonitrile polymerization on the surface of porous microspherical silica gel (PMSS) was studied and some kinetic parameters were determined. The structure of PMSS-based sorbents was analyzed by FTIR-spectroscopy, XRD and sorption analysis before and after microcapsulation with polyacrylonitrile.     

Abiotechnology of Indigofera tinctoria L. on the Saline Land of Aral Sea Basin and Producing of the Natural Plant Indigo Pigment for the Industry

The possibility of cultivation of lndigofera tinctoria L. plants in ecologically degraded and saline lands of the Aral Sea Basin was studied. A new salt-resistant Indigofera plant variety ＂Feruz-l＂ was producing by the classic methods of genetics and modem biotechnology.Agro-technology of cultivation as main and secondary culture after wheat was developed and recommended to the farmers of the country.The biotechnology of natural plant pigment indigo extraction has been developed and was recommended for using in different fields of industry： textile, pharmacy-pharmacology, perfume-cosmetic, architectural-decorative and food industry. Quantitative and qualitative HPLC （high pressure liquid chromatography） method of determination of plant natural indigo has been also developed.     

Manifestation If Substance Molecular Structure in Temperature Effects of Light Scattering

DCMSL （depolarization components of molecular scattering of light） have been studied within the wide spectral range （0-200 cm-1） and in the temperature intervals （20-200 ℃） in toluol （C6HsCH3） and aniline （C6HsNH2）. It has been shown that when a liquid is heated and temperatures approach to critical ones, a significant contribution of DCMSL is made by vibration motion of molecules. The special properties of the temperature-frequency behavior of DCMSL spectra are discussed from the view point of hindered rotation of liquid molecules with consideration of intermolecular interaction.     

Green foliage decomposition in tree plantations on degraded,irrigated croplands in Uzbekistan,Central Asia

Afforestation is a prospective strategy to improve soil fertility of salt-affected, irrigated croplands in Central Asia. The effect of macro- and mesofauna and microflora on the decomposition of tree leaves, collected ca. 2 weeks before natural fall, was monitored during 367 days. The three-year-old tree plantations consisted of Elaeagnus angustifolia L., Ulmus pumila L., and Populus euphratica Oliv. The leaf decay rate was determined in 25 × 25 cm sized polyester litterbags with mesh sizes of 10,000 μm (coarse), 250 μm (medium), and 20 μm (fine). Decomposition in the coarse litterbags, allowing access by the entire decomposer community, was highest in P. euphratica at 61% weight loss after 367 days. In the same period, the weight loss in E. angustifolia was 51% and in U. pumila 52%. Combined correlation and multiple regression analyses revealed that decomposability was determined by mesh size, initial C/N ratio, crude fiber-to-N (CF/N) ratio, leaf area, and specific leaf area. A high correlation existed between traits impacting decomposition by the entire decomposer population and the digestibility of leaves by animals as measured in the laboratory (the in vitro digestibility). Initial leaf N (34 g N kg⁻¹ DM) content was highest in E. angustifolia, followed by 23 g N kg⁻¹ DM in U. pumila and 22 g N kg⁻¹ DM in P. euphratica. The C/N ratio followed the order of P. euphratica (21.8) > U. pumila (19.4) > E. angustifolia (13.1). The CF/N ratio followed the order P. euphratica (5.2) > E. angustifolia (3.9) > U. pumila (2.9). Despite a lower decay rate and a higher N content remaining in leaves after 367 days in comparison to both other species, E. angustifolia had the highest potential for soil bio-amelioration. This was due to its foliage production (6 t ha⁻¹ on average), which was about 2.5 times higher than that of the other species, giving a total leaf N loss of about 97 kg N ha⁻¹ in coarse mesh bags. The N loss from U. pumila and P. euphratica leaves amounted to 33 and 23 kg N ha⁻¹, respectively. The potential of leaf decomposition for supplementing soil N in the region depends on the decay rate, the initial leaf N content, the annual leaf biomass production, and differences between N contents over the course of the decomposition period. These can be additional criteria for selecting tree species suitable for afforestation of the degraded, irrigated croplands in Central Asia.     

Development of electroconductive polyacrylonitrile fibers through chemical metallization and galvanisation

The paper describes the modification of PAN fibres with metallic nickel in order to give the fibre electroconductive properties. This is achieved by two consecutively executed processes. The first process is chemical metallization, involving the immersion of the PAN fibres in a bath containing 0.5 mol l⁻¹ NiCl₂ and 1.5 mol l⁻¹ Rongalite at pH = 5.5 and T=288–293 K. Ni(II) is absorbed in the structure of the fibre and adsorbed at the surface through a complex reaction with the cyanide and carboxylic acid groups present in the PAN chemical structure and the Rongalite reduces the adsorbed Ni(II) to metallic Ni. The second process is galvanisation of the Ni-containing PAN surface (the Ni particles present at the surface form a “seed” layer) in an electrolyte bath using an electrolyte with 150 g l⁻¹ of NiSO₄ at pH 5–6 and room temperature. The resulting fibre showed a specific electrical resistance of the order of 10⁻⁶ Ω m, which is a promising result.