Flexible Polymer–Organic Solar Cells Based on P3HT:PCBM Bulk Heterojunction Active Layer Constructed under Environmental Conditions

In this study, some crucial parameters were determined of flexible polymer–organic solar cells prepared from an active layer blend of poly(3-hexylthiophene) (P3HT) and the fullerene derivative [6,6]-phenyl-C₆₁-butyric acid methyl ester (PCBM) mixed in 1:1 mass ratio and deposited from chlorobenzene solution by spin-coating on poly(ethylene terephthalate) (PET)/ITO substrates. Additionally, the positive effect of an electron transport layer (ETL) prepared from zinc oxide nanoparticles (ZnO np) on flexible photovoltaic elements’ performance and stability was investigated. Test devices with above normal architecture and silver back electrodes deposed by magnetron sputtering were constructed under environmental conditions. They were characterized by current-voltage (I–V) measurements, quantum efficiency, impedance spectroscopy, surface morphology, and time–degradation experiments. The control over morphology of active layer thin film was achieved by post-deposition thermal treatment at temperatures of 110–120 °C, which led to optimization of device morphology and electrical parameters. The impedance spectroscopy results of flexible photovoltaic elements were fitted using two R||CPE circuits in series. Polymer–organic solar cells prepared on plastic substrates showed comparable current–voltage characteristics and structural properties but need further device stability improvement according to traditionally constructed cells on glass substrates.     

Preparation of 3,4-fused-spiro[furan-5(5H),4′-piperidin]-2-one

A general method for the preparation of various 3,4-fused-spiro[furan-5(5H),4′-piperidin]-2-one with high yield is reported. The formation of spiro[furanone-piperidine] structure was achieved by a Suzuki coupling, followed by an iodolactonization reaction.     

Molar heat capacities of the tellurites CoTeO3, MnTeO3 and MnTe6O13 in medium temperature range

The temperature dependence of the molar heat capacities of the tellurites CoTeO₃, MnTeO₃ and MnTe₆O₁₃ are determined. By statistical manipulation of the values obtained, the parameters in the equations for the corresponding compounds showing this dependence are determined using the least-squares method. These equations and the standard molar entropies are used to determine the thermodynamic functions for T'=298.15 K.     

Preconcentration of trace elements on a support impregnated with sodium diethyldithiocarbamate prior to their determination by inductively coupled plasma-atomic emission spectrometry

A procedure is developed for determination of As, Co, Se, Cr, Pb, Zn, Cu, Mn, Cd, Sb, and Sn in water by ICP-AES analysis of alcohol eluates after pre-concentration of the samples. The pre-concentration is performed on a sodium diethyldithiocarbamate supported soft polyurethane foam. The sorbed elements are subsequently eluted with 1-propanol and the alcohol eluates are analysed by ICP-AES. A eight-fold concentration is achieved. An increased sensitivity in the analysis of propanol-water (30:70, v/v) solution is established as compared with aqueous solutions. The strongest effect is observed for As, Se, Pb, Cr, Sn, and Cd-increasing is more than twice. For other elements the matrix influence is by a factor of 1.45 (Cu), 1.36 (Sb), 2.08 (Zn). The method is applied to the analysis of natural water samples.     

Thermodynamic properties of germanium and lead tellurites

The temperature dependence of the molar heat capacities of the tellurites PbTeO₃, Pb₂Te₃O₈ and Ge(TeO₃)₂ are determined. By statistical manipulation of the values obtained, the parameters in the equations for the corresponding compounds showing this dependence are determined using the least-squares method. These equations and the standard molar entropies are used to determine the thermodynamic functions Δ₀ ^T S _m ⁰ , Δ_T ^T H _m ⁰ and (Φ_m ⁰+Δ₀ ^T H _m ⁰/T) for T'=298.15 K.     

Specific heat capacity and thermodynamic properties of CuTeO3 and HgTeO3

Tellurites of CuTeO₃ and HgTeO₃ are synthesized and their specific molar heat capacities are experimentally determined for the first time. The tellurites discussed in the present paper are used for preparation of optical glasses with special properties for optoelectronics, nuclear and power industries. The tellurites synthesized are prepared for chemical analysis, differential thermal analysis and X-ray analysis. The use of the tellurites studied is related to knowing their thermodynamic properties like specific molar heat capacity (C _p,m), enthalpy \( \left( {\Delta_{{{\text {T}}^{\prime}}}^{\text{T}} H_{\text{m}}^{0} } \right), \) entropy \( \left( {\Delta_{{{\text {T}}^{\prime}}}^{\text{T}} S_{\text{m}}^{0} } \right) \) and Gibbs energy \( \left( { - \Delta_{{{\text {T}}^{\prime}}}^{\text{T}} G_{\text{m}}^{0} } \right) \) . The temperature dependences of their molar heat capacities are determined using the least squares method. The thermodynamic properties are calculated: entropy, enthalpy and Gibbs function.     

ESR study of carbon monoxide adsorption on rhodium exchanged Y zeolites

() () [M–Br]⁺ . .

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Ionisation potentials (IP) of alkyl substituted brombenzenes and appearance potentials (AP) for [M–Br]⁺ ions were determined. IP are in a good accordance with inductive effects, whereas AP are discussed within field effect framework.

     

Periodicity in the Appearance of Intervals of the Reversal of the Magnetic Moment of a ϕ0 Josephson Junction

JETP Letters - The uniaxial anisotropy and kinetics of the transformation of the domain structure in a ferrimagnetic GdFeCo film exchange-coupled to the IrMn antiferromagnet have been studied in a...     

Isolation of Novel Alkaliphilic <Emphasis Type="Italic">Bacillus</Emphasis> Strains for Cyclodextrin Glucanotransferase Production

New alkaliphilic Bacillus producers of cyclodextrin glucanotransferase (CGTase, EC 2.4.1.19) were isolated from 17 Bulgarian alkaline and normal habitats (springs and soils) by three steps of a selection. None of the isolates obtained, producing CGTase, appeared to be thermophilic in character. One hundred and thirty-seven strains were estimated for CGTase activity by batch cultivation in a liquid alkaline medium. Twenty-seven of them had a detectable CGTase activity in their culture supernatants under the enzyme assay conditions, despite of the significant growth of all isolates. The phenotypic properties of three selected strains (20RF, 8SB and 24WE) were determined. They were aerobic endospore-forming Bacillus strains: two of them were obligated alkaliphiles (20RF and 8SB) and one, alkalitolerant (24WE). Both obligated alkaliphiles were further characterised by 16S rRNA analysis. According to the full 16S rRNA gene sequences obtained and deposited to the NCBI GenBank database, both isolated obligated alkaliphiles 20RF and 8SB were clustered into the group of alkaliphilic Bacillus species. The exhibited CGTase production by them (230–250 U ml⁻¹ for 20RF and 130–160 U ml⁻¹ for 8SB) defined these new isolates as promising producers of the enzyme, especially Bacillus sp. 8SB synthesising thermostable alkaline β-CGTase. Both new enzymes from 20RF and 8SB Bacillus strains formed only two types of cyclodextrins, beta and gamma, which could be of interest for their easy separation and industrial production.