The security of electricity supply as the determinant of sustainable development

It is defined the term security of energy supply and identified its segments in the article. The role of electricity in sustainable development is analyzed. The article emphasize the importance of a secure electricity supply that is a key prerequisite to well-functioning modern society

Unusual behavior of growing pollen tubes in the ovary of plum culture (Prunus domestica L.)

Unusual behavior of growing pollen tubes in different combinations of pollination was observed in the ovary of the plum (Prunus domestica L.) cv 'Čačanska Lepotica'. It primarily refers to several issues, i.e. the curling up of pollen tubes within the micropyle, the growth of two pollen tubes into the nucellus of an ovule, the occurrence of a bundle above the nucellar cap and fluorescence of the part of the embryo sac containing the egg apparatus. Upon the growth of pollen tubes into the nucellus of the ovule, subsequently penetrating pollen tubes form a bundle either above the micropyle entrance or above the nucellus. Branching and bending of pollen tubes by 180o upon their growth into the micropyle was also observed

Interfacial Polarization and Dielectric Properties of Epoxy/Graphite Flakes Composites

Dielectric properties of composites based on bisphenol-A-epoxy resin loaded with various content of graphite flakes (GF) have been studied. The dielectric permeability, tangent loss and ac conductivity have been examined in wide temperature (170 – 370 K) and frequency (20 Hz – 200 kHz) range. In composites loaded with GF flakes up to 10 wt.%, the dominant conduction mechanism is tunneling of electrons, while loading of 15 wt.% gives rise to electron conduction through direct contacts between fillers. Dielectric properties of composites are largely determined by the nature of the filler/matrix interface, the filler surface area and the inherent conductivity of the fillers. At low electric field frequencies, dominates socalled interfacial (or space charge) polarization due to accumulation of free charges at the interfaces between two phases (filler and matrix), which differ in electrical conductivity.Influence of the filler surface chemistry have been studied for composites loaded with 5 wt.% graphite flakes obtained: (i) under wet milling, without (GF) or with (GF-Tr100x) adding Triton-100x as a surfactant, or (ii) under dry milling in the presence of KOH (GF-KOH). The surface treatment with KOH notable increased dielectric constant of the epoxy/GF-KOH5 composite, keeping low tangent loss, comparable to the counterpart, the epoxy/GF5 composite

Phenolic Compounds and Antioxidant Properties of Field-Grown and In Vitro Leaves, and Calluses in Blackberry and Blueberry

The aim of this study was to evaluate the content and profile of the phenolic compounds (PCs) and antioxidant properties of field-grown leaves, in vitro leaves and in vitro callus cultures of the blackberry ‘Čačanska Bestrna’ and blueberry ‘Toro’. In vitro shoots of the selected genotypes were grown either on original Murashige and Skoog (MS) medium containing 1 mg/L BA, 0.1 mg/L IBA and 0.1 mg/L GA3 (‘Čačanska Bestrna’) or on MS medium with macroelements reduced to 1/2, 2 mg/L zeatin and 0.2 mg/L IAA (‘Toro’). Callus cultures were induced from in vitro leaves and established on MS medium with 2 mg/L BA and 2 mg/L 2,4-D (‘Čačanska Bestrna’) or MS medium with half strength macroelements, 2 mg/L BA, 2 mg/L 2,4-D and 1 mg/L NAA (‘Toro’). Total phenolic (TPC) and flavonoid content (TFC) were the highest in blueberry leaves, whereas low TPC and TFC values were obtained in callus cultures of both cultivars. A higher content of PCs in blueberry leaves compared to blackberry leaves was determined by the UHPLC-DAD MS/MS technique. Quercetin derivatives and phenolic acids were the dominant PCs in the leaves of both berries, whereas gallocatechin was present in a significant amount in blueberry leaves. Callus cultures of both berries had a specific PC profile, with none detected in the leaves except quercetin-3O-glucoside and quercetin-3-O-rutinoside. Blackberry leaves showed the best antioxidant properties as estimated by ferric reducing power (FRP), ABTS•+ and DPPH• scavenging activity assays. Callus cultures of both berries exhibited three to five times lower ABTS•+ and ten to seventeen times lower DPPH• scavenging activity compared to corresponding leaves. The analyzed leaves and callus cultures can be a good source of PCs with good antioxidant properties and specific phenolics, respectively, for applications in the food and pharmaceutical industries

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

Meeting abstrac

Cryopreservation of apple shoot tips by vitrification and subsequent plant regeneration

This paper investigates the influence of composition of vitrification solution on the regrowth capacity of apple 'Gala Must' (Malus x domestica Borkh.) cryopreserved by a vitrification technique. In vitro-grown shoot tips were precultured in the dark at 23 degrees C, in a liquid MS medium with two sucrose treatments (0.3 M for 15 h, then 0.7 M for 5 h). After loading at room temperature with solution containing 2 M glycerol and 0.4 M sucrose for 20 min, explants were dehydrated at 0 degrees C for 30, 40 and 50 min. Dehydration was done using either original PVS2 (13.7% w/v sucrose, 30% w/v glycerol, 15% w/v ethylene glycol, 15% w/v DMSO) or modified PVS2 solution (PVS A3 - 22.5% w/v sucrose, 37.5% w/v glycerol, 15% w/v ethylene glycol and 15% w/v DMSO). The survival and regrowth of the cryopreserved shoot tips dehydrated with the original PVS2 solution ranged between 40 and 85 and 20-40%, respectively. The highest values of both parameters were achieved with longest treatment duration. Dehydration with the PVS A3 solution resulted in considerably higher survival rates (68.2-90%), as well as higher regrowth rates (15-75%) after cryopreservation. Fifty-min treatment with this vitrification solution led to a significant increase in the percentage of regrowth (up to 75%). After regrowth, shoots were successfully multiplied and rooted. These results prove the feasibility of the PVS A3 based vitrification technique for a long-term storage of this genotype

SOLID SOLUTION FORMATION DURING LIQUID PHASE SINTERING

Les résultats obtenus sur les frittes de MgAl2O4 ont montré que la formation de solutions solides entre certains constituants de la phase liquide et du spinelle, favorisait la densification. La formation de solutions solides n'a pas une influence importante sur le grossissement des grains.Results obtained during liquid phase sintering of spinel powder showed that solid solution formation between the spinel and some of liquid components enhanced densification. However the solid solution formation did not influence grain growth process during sintering of MgAl2O4 powder

Evaluation of the Quality of Clothing Fabrics in Terms of Their Compression Behaviour before and after Abrasion

In this work, the compression behaviour of clothing woven fabrics, before and after abrasion on the Martindale's device, has been examined. Plain and 3/1 twill weave fabrics from cotton and cotton/polyester fiber blends served as experimental material. Compression behaviour of the investigated fabrics was analyzed taking the compressibility, thickness loss, and compressive resilience into consideration. Obtained results showed that the changes of compression properties are in a function of the structural parameters of tested fabrics, as well as damages caused by abrasion. Besides, the results of compressibility, thickness loss, and compressive resilience enabled establishing the quality of examined fabrics based on values of complex criterion. Calculated value of complex criterion pointed to the conclusion that abrasion causes the reduction of quality of tested fabrics in a small extent. Twill weave fabric made of cotton/polyester fiber blends is characterized by the best quality while cotton plain weave fabric has the worst quality, before as well as after abrasion

DOI:10.2298/ABS1001137D UNUSUAL BEHAVIOR OF GROWING POLLEN TUBES IN THE OVARY OF PLUM CULTURE (PRUNUS DOMESTICA L.)

Abstract – Unusual behavior of growing pollen tubes in different combinations of pollination was observed in the ovary of the plum (Prunus domestica L.) cv ‘Čačanska Lepotica’. It primarily refers to several issues, i.e. the curling up of pollen tubes within the micropyle, the growth of two pollen tubes into the nucellus of an ovule, the occurrence of a bundle above the nucellar cap and fluorescence of the part of the embryo sac containing the egg apparatus. Upon the growth of pollen tubes into the nucellus of the ovule, subsequently penetrating pollen tubes form a bundle either above the micropyle entrance or above the nucellus. Branching and bending of pollen tubes by 180º upon their growth into the micropyle was also observed. Key words: Plum, ovary, pollen tube growth, fluorescent microscop

Dielectric investigation of some woven fabrics

In this paper, we have investigated the temperature dependence of dielectric properties (relative dielectric permeabilities and dielectric tangents of losses) for woven fabrics of hemp, jute, flax, cotton, polyester (PES), cotton-PES mixture, and wool. The measurements have been carried out at a temperature range from -50 to 50 degrees C in the electric periodic field at a frequency 1 MHz in vacuum. For the same specimens, the values of the dielectric properties have also been measured at an air temperature of 21 degrees C and at relative humidities of 40%, 60%, and 80%. At different frequencies from 80 kHz to 5 MHz, the dielectric properties have been measured at a relative humidity of 40% and at a temperature of 21 degrees C. An investigation of the dielectric properties of woven fabrics can provide a better understanding of the relation between the dielectric properties of woven fabrics and the different raw material compositions, temperatures, relative air humidities, and frequencies for specimens. Hence, this investigation helps to improve textile material properties