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Małgorzata Zięba

Abstract

Purpose: This paper aims to explore the topic of knowledge safety, defined as the state of knowledge being safe from loss, leakage, attrition, oblivion, waste or theft. The paper first presents a theoretical background and review of previous studies on knowledge loss and ways of overcoming it, and then illustrates the topic of knowledge safety with ten case studies from the small and medium-sized enterprises (SMEs) sector. Methodology: The paper is based on an analysis of Knowledge Management (KM) literature devoted to knowledge loss and its potential types in companies, and on the results of case study research. Knowledge safety was first defined and contrasted with other terms, and then examined in 10 selected SMEs. The research resulted in a clarification of what SMEs understand by the term of “knowledge safety” and what kind of measures they take to ensure it. Findings: As the analysis shows, the examined SMEs attribute diversified significance to the issue of knowledge safety. For some of them, such problem does not exist at all and they state that they can ensure knowledge safety in all aspects of their operations. Some companies perceive it mainly through the safety of the knowledge stored in electronic databases, while others link it with the human factor only. Research limitations: Research results are limited to ten companies operating in Poland. As such, they cannot illustrate the whole picture of the existing small or medium-sized companies. Research implications: The findings of both literature review and case study analysis indicate that there is a need to further examine the issue of knowledge safety by analysing the potential factors which may endanger knowledge safety and the methods to eliminate such risks. Practical implications: The paper examines important aspects of knowledge safety and provides guidelines on how it can be ensured by managers or owners of SMEs. Originality/value: The term of knowledge safety has been absent from the related literature so far. The paper defines it and explores both the theoretical and the practical aspects thereof. The paper also suggests further research possibilities in this area.

Open access

Małgorzata Kapelko-Żeberska, Tomasz Zięba, Radosław Spychaj and Artur Gryszkin

Abstract

This study was aimed at determining the effect of acetylation degree and crosslinking of retrograded starch with adipic acid on selected rheological properties of prepared pastes and gels. The esterification of retrograded starch allowed obtaining preparations with various degrees of substitution with residues of acetic (0.7–11.2 g/100 g) and adipic acids (0.1–0.3 g/100 g). Acetylation and crosslinking caused a decrease in amylose content of the preparations (3–21 g/100 g). Solubility of the preparations in water, in a wide range of variability, was increasing along with an increasing degree of acetylation and with a decreasing degree of crosslinking (19–100 g/100 g). Values of most of the rheological coefficients determined based on the flow curves of the prepared pastes and mechanical spectra of gels (3.5<K<31.5 Pa×sn, 4.2<τ0C<70 Pa, 0.26<tg α<0.57) were increasing in a wide range along with increasing crosslinking of starch. Changes in the rheological properties upon the effect of double modification were not the sum of changes proceeding as a result of single modifications. Instead, interaction of both factors was observed. The conducted modifications enable modelling the properties of produced preparations.

Open access

Katarzyna Kirsz, Małgorzata Szczęsna, Anna Borsuk and Dorota A. Zięba

Abstract

The maintenance of energy homeostasis is achieved with ‘detectors’ that receive signals from the external and internal environment and with multidirectional ‘communication routes’ including neuronal networks and body fluids, such as blood and cerebrospinal fluid. Changes in the energy demands of organisms are caused by current physiological status and environmental conditions, including season and food availability. Little is known about the interactions between the metabolic indicators involved in the maintenance of energy homeostasis, e.g., leptin, orexins and ghrelin. Sheep and other seasonal animals are highly adaptable to their environments because of the plasticity of their neural and endocrine systems. Sheep exhibit leptin resistance and are thus an extremely interesting model for research on the relationship between hormonal indicators of energy metabolism. The paper is focused mainly on the anatomical and functional communication between leptin, ghrelin and orexins, which play principal roles in the adaptation of energetic demands to environmental fluctuations.

Open access

Katarzyna Kirsz, Małgorzata Szczęsna, Edyta Molik, Tomasz Misztal and Dorota A. Zięba

Abstract

The influence of leptin on orexin A and the interaction of leptin with ghrelin in regulating the gonadotropic and somatotropic axes in seasonally polyestrous animals are not well understood. This study examined the effects of these factors as well as the mediating roles of specific ovine leptin antagonist (SOLA; mutant D23L/L39A/D40A/F41A) and photoperiod on luteinizing hormone (LH) and growth hormone (GH) secretion. Twenty-four ovariectomized, estradiol-implanted ewes were used in a replicated switchback design. The ewes were assigned randomly to 1 of 6 treatments (infused into the third ventricle 3 times at 0 (dusk), 1, and 2 h) as follows: control, Ringer-Locke buffer; leptin, 0.5 μg/kg b.w.; orexin A, 0.3 μg/kg b.w.; ghrelin, 2.5 μg/kg b.w.; SOLA, 50 μg/kg b.w. + orexin A, 0.3 μg/kg b.w.; and SOLA, 50 μg/kg b.w. + ghrelin, 2.5 μg/kg b.w. Blood samples (5 ml) were collected at 15-min intervals for 4 h. SOLA + orexin A resulted in an increase (P<0.01) in the LH plasma concentration during short-day (SD) and long-day (LD) photoperiods. However, ghrelin and SOLA + ghrelin had the opposite effect. SOLA + orexin A resulted in an increase (P<0.001) in the GH concentration compared with leptin or orexin A during the LD season. Ghrelin and SOLA + ghrelin increased the GH concentration (P<0.01) regardless of the season. In summary, LH and GH secretion are seasonally dependent on relationships that are subject to photoperiodic regulation, and leptin is an important regulator of the effects of ghrelin and orexin A on the activities of the gonadotropic and somatotropic axes in sheep.

Open access

Artur Gryszkin, Tomasz Zięba and Małgorzata Kapelko-Żeberska

Abstract

The objective of this study was to determine the effect of heating a water dispersion of corn starch to various temperatures, followed by its freezing and defrosting, on selected properties of re-formed starch pastes. A suspension of starch was heated to various temperatures ranging from 59 to 94°C, and afterwards frozen and defrosted. The differential scanning calorimetry (Mettler Toledo, 822E) thermal characteristics of starch pre-heated to temperatures not inducing complete pasting revealed transitions of: (I) retrograded amylopectin, (II) non-pasted starch, (III) amylose-lipid complexes, (IV) retrograded amylose, and (V) highly thermostable starch structures. The application of higher temperatures during heating caused disappearance of transitions II and V. The increase of pre-heating temperature induced firstly a decrease and then stabilization of the swelling power as well as a successive decrease in starch solubility. Pastes pre-heated to temperatures over 79°C contained large macroparticles that were increasing viscosity of the re-formed starch paste (their size was positively correlated with viscosity value).

Open access

Małgorzata Zięba, Anna Małysa, Tomasz Wasilewski and Marta Ogorzałek

Abstract

The study addressed the effect of the structure of silicone polyethers on selected functional properties of cotton fabric rinsed in conditioners containing the additives under study. Fabric softener formulations containing two comb-structured compounds (PEG/PPG-14/0 Dimethicone and PEG/PPG-20/20 Dimethicone) and one block-structured compound (Bis-PEG/PPG-20/20 Dimethicone) were developed. Cotton fabric rinsed in conditioners containing silicone glycols was not found to be affected by yellowing. However, differences were noted in the softening ability and re-wettability of rinsed fabrics due to diverse structures of the additives used. The most desirable soft hand effect was observed after cotton rinsing in fabric softeners containing the block-structured compound Bis-PEG/PPG-20/20 Dimethicone. In contrast, the highest fabric re-wettability was shown for the conditioner enriched with a comb-structured compound (PEG/PPG-20/20 Dimethicone). The study results demonstrate that the prototypical fabric softeners containing silicone derivatives have a potential to provide quality characteristic required by consumers of this product group.

Open access

Małgorzata Musztyfaga-Staszuk, Łukasz Major, Grzegorz Putynkowski, Anna Sypień, Katarzyna Gawlińska, Piotr Panek and Paweł Zięba

Abstract

Potential impact of copper replacing silver in the paste used for the front electrode fabrication in crystalline silicon solar cells was investigated. The copper was applied as a new CuXX component with about 2 wt.% to 6 wt.% share of XX modifier. The generated CuXX molecules were analyzed using transmission microscopy. Based on the commercial Du Pont PV19B paste, CuXX and XX materials, the new PV19B/CuXX paste with 51 wt.% share of Cu and the PV19B/XX paste with 51 wt.% share of XX only were developed. Comparative studies of the effect of the commercial PV19B paste made by DuPont Company, and the pastes with the CuXX component and with the modifier XX alone on the electrical parameters of solar cells produced on crystalline silicon were carried out. The solar cells were characterized by the current-voltage technique. As a final result, the Cz-Si solar cell with the 51 wt.% share of Cu in the front electrode having a series resistance of 0.551 Ω·cm2, an efficiency of 14.08 % and, what is more important, the fill factor of 0.716, was obtained. It is the best result ever obtained concerning direct Cu application for solar cells fabricated in thick-film technology.