Wettability of poly(tetrafluoroethylene) (PTFE) by aqueous solutions of binary mixtures composed of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) with polyoxyethylene (23) lauryl ether (Brij 35) was considered on the basis of the measured values of contact angle and surface tension. It was shown that the value of the critical surface tension of PTFE surface wetting at the studied system (23.5 mN/m), does not depend on the concentration and composition of the binary mixtures of studied surfactants in water, and it was higer than the surface tension of PTFE (20.2 mN/m). The best wettability of polytetrafluoroethylene (PTFE) by studied aqueous solutions of binary surfactants mixtures occurs at the mixtures concentration corresponding to the critical micelle concentration of their solutions.
Józefa Krawczyk, Joanna Obrzut, Sylwester Świątkiewicz and Jolanta Calik
The aim of the studies was to evaluate the effect of the diet in the final growth phase and slaughter age of poulards on productivity, dressing percentage, carcass colour and physicochemical properties of meat. The studies were conducted on 78 hybrids obtained by crossing Ross 308 broiler roosters with Rhode Island Red (R-11) dual-purpose laying hens (♂Ross 308 × ♀R-11). Birds were assigned to 3 groups: control group (K) fed starter, grower and finisher diets without addition of dairy products, experimental group S offered a finisher diet supplemented with 4% whey, and experimental group M receiving 4% milk powder supplement in the final growth phase. Spaying procedure was carried out at 8 weeks of age. Poulards were slaughtered at 18 and 20 weeks of age. The studies showed that by using hybrids of dual-purpose hens with broiler roosters for production of poulards, rearing period could be shortened to 18 weeks, and the obtained meat had comparable or even better quality traits compared with poulards slaughtered at 20 weeks of age. Supplementation of poulard diet with 4% whey or milk powder in the final growth phase had a beneficial effect mostly on improvement of sensory properties of meat. There were not many significant differences in meat quality between poulards fed the diet supplemented with milk and whey but instead there were differences between these groups and the control group fed the diet without these additives.
Dorota Wojtysiak, Jolanta Calik, Józefa Krawczyk, Joanna Wojciechowska-Puchałka, Joanna Obrzut and Karolina Nahajło
In recent years, consumers have increasingly sought niche food products with specific aroma and flavour, and rich in nutrients. With a growing demand for quality poultry products, there is an opportunity to increase production of capons, which are more and more often marketed as high quality products, because their meat is more delicate, tender and juicy. Therefore the objective of this study was to compare meat quality parameters and rate of protein degradation between capon and cockerel breast muscle during postmortem aging. Fibre type diameter, intact desmin and dystrophin contents at 15 min, 24 h, and 48 h postmortem and the following technological parameters of breast meat were also determined: pH15, pH24, pH48, drip loss, shear force. The study was carried out on hybrids between Rhode Island Red cockerels (R-11) and Yellowleg Partridge hens (Ż-33) aged 24 weeks. The current findings indicate that compared with cockerel breast muscles, the capon breast muscles had significantly higher pH15 (P≤0.01), and lower drip loss (P≤0.01) and shear force values (P≤0.05). Additionally, the intensity of intact desmin and dystrophin in capon breast samples at 24 h and 48 h postmortem was significantly lower (P≤0.05) than that in the cockerel breast sample. In turn, the lower rate of desmin and dystrophin degradation (P≤0.05), along with higher drip loss in cockerel compared to capon breast muscles, may account for their lower muscle fibre diameters at 24 h and 48 h postmortem. Moreover, the rate of early postmortem pH decline can partly explain the variation of desmin and dystrophin degradation.
Paulina B. Nowicka-Krawczyk and Joanna Żelazna-Wieczorek
Woronichinia Elenkin is a cyanobacteria genus characteristic of lentic ecosystems. The type species, W. naegeliana (Unger) Elenkin, often blooms in the plankton of eutrophic reservoirs but this genus also contains species sensitive to high nutrient concentrations. The study analyzed the diversity and biomass of Woronichinia in lakes in a national park, isolated from the direct impact of human activity. The lakes were in various trophic states resulting from gradual and natural changes of trophy. Trophy was assessed with the use of the trophic diatom index, according to the classification we proposed for natural lakes. The relationship between the biomass and the trophic state of lakes was investigated with the use of multivariate unconstrained analysis with supplementary variables. Five species of Woronichinia were identified in all trophic types of lakes except for two oligotrophic ones: W. compacta (Lemmerm.) Komárek & Hindák, W. delicatula (Skuja) Komárek & Hindák, W. karelica Komárek & Komárk.-Legn., W. obtusa Joosten and W. naegeliana (Unger) Elenkin. The occurrence and biomass of the species were related to the trophic state of the lakes. The absence of Woronichinia in two oligotrophic lakes could be due to the high concentration of humic compounds in the sediments. The low nitrogen-to-phosphorus ratio characteristic of the oligo-mesotrophic lakes resulted in increased species diversity. The lakes’ isolation from human activity fostered the development of rare and sensitive species such as W. delicatula and W. karelica.
Joanna Obrzut, Józefa Krawczyk, Jolanta Calik, Sylwester Świątkiewicz, Mariusz Pietras and Katarzyna Utnik-Banaś
The aim of the study was to determine the effect of genotype (breed/line) and spaying of pullets on body weight, estradiol level, carcass and meat quality. Subjects were Rhode Island Red (R-11), Yellowleg Partridge (Ż-33) and Sussex hens (S-66), 100 birds per line, which were divided into 2 groups, each having 50 pullets and 50 poulards. Spaying was performed at 10 wk of age, under local anesthesia by a veterinarian. The present study showed that blood estradiol levels in poulards were much lower than in pullets regardless of genotype. Poulards showed higher body weight and their carcasses higher lightness and yellowness. In the sensory evaluation, poulard breast meat was more tasty and leg meat also more juicy and tender compared to pullet meat. Among the three conserved breeds, Rhode Island Red (R-11) and Yellowleg Partridge (Ż-33) hens are the best starting material for poulard production. Their carcasses showed good muscling and intense yellowness desirable to the consumers. R-11 birds achieved highest body weight. Spaying of pullets had no significant effect on the profile of fatty acids, but greater and statistically significant differences in this regard were found between hen lines. Compared to S-66 birds, breast muscles of R-11 and Ż-33 birds contained more polyunsaturated fatty acids (PUFA). The breast and leg muscles of these birds had a lower content of saturated fatty acids (SFA ).
Andrzej Bożyk, Joanna Krawczyk, Leszek Szalewski, Emma Kiworkowa and Jolanta Szymańska
Introduction. Caries of deciduous teeth in the population of Polish children is a significant health, social and organizational problem.
Aim. The aim of the study was to evaluate the dentition of 3- and 4-year-old children in the Mazowieckie Province.
Material and methods. The study comprised 393 kindergarten children aged 3 and 4 years in the Mazowieckie Province, 202 girls and 191 boys, including 159 children aged 3 years and 243 children aged 4 years. In all subjects the state of dentition was assessed. The prevalence of caries was calculated as the percentage of people affected by this disease, and the intensity of dental caries was determined using the dmft index. The results were compared with those that Polish researchers obtained in the 3 – and 4-year-olds after 2000.
Results. In the studied group of 3- and 4-year-olds the prevalence of caries was 62.85%, among girls – 61.88% and among boys – 63.87%. For all subjects the average scores for dmft index were 3.22 and its components dt – 2.72 (decayed teeth), mt – 0.1 (missing teeth), ft – 0.4 (filled teeth).
Conclusions. The prevalence and intensity of dental caries in 3- and 4-year-old children attending kindergartens in the Ma-zowieckie Province is high and close to the national average. It is advisable to increase the preventive and curative measures in this age group of children on dental caries.
Małgorzata Stodókiewicz, Joanna Krawczyk, Jacek Szkutnik and Marcin Berger
Introduction. Periodontitis is a group of inflammatory disorders affecting periodontal tissues. This condition manifests by a progressive destruction of the alveolar bone, subsequently leading to tooth loss. World Health Organization introduced Community Periodontal Index of Treatment Needs in order to gain data regarding periodontal health and treatment needs of people with periodontitis
Aim. To evaluate the periodontal status of citizens living in the city of Lublin and its surrounding, using Community Periodontal Index of Treatment Needs (CPITN).
Material and methods. Community Periodontal Index of Treatment Needs was used to assess the periodontal status among 180 patients aged 35-44 residing in Lublin and the area around it.
Results. Periodontal diseases have been observed in over 90% of the examined population. Treatment need index TN1 has referred to 26.11% of the patients, TN2 – 61.67% and TN3 – 2.22% respectively.
Conclusions. Patients who visit the dentist regularly have a better periodontal status as compared to groups randomly selected.
Jolanta Calik, Katarzyna Połtowicz, Sylwester Świątkiewicz, Józefa Krawczyk and Joanna Nowak
The objective of the study was to determine the effect of caponizing Greenleg Partridge cockerels on slaughter parameters and meat quality. In total 80 Greenleg Partridge cockerels were assigned to two groups with 40 birds per group. Group I (control) consisted of uncastrated cockerels and group II contained birds that were castrated at 8 weeks of age. Birds were kept until 24 weeks of age and fed the same diet ad libitum. Body weight was recorded at 1, 8, 16 and 24 weeks of age. Dressing percentage, proportion of breast and leg muscles, giblets and abdominal fat, and microstructure of the pectoralis superficialis muscle were determined postmortem. Physicochemical characteristics of meat (pH, CIE L*a*b* colour, water holding capacity, drip loss, thawing loss, cooking loss, shear force, texture parameters and chemical composition) were determined and sensory evaluation was performed. The castration of Greenleg Partridge cockerels contributed to increases in body weight, dressing percentage, and carcass muscle and fat content, and changed the colour of bird skin and muscles. The leg muscles of capons were characterized by higher pH24h, better water holding capacity, a tendency for higher fat concentration, and better sensory quality. The breast muscles of castrated cockerels lost more water and were tougher than the same muscles from uncastrated cockerels, but received better scores for flavour. In conclusion, the results of this study indicate that the caponized Greenleg Partridge cockerels can be used as a valuable material for production of high quality meat.
Michał Młotek, Bogdan Ulejczyk, Joanna Woroszył, Irmina Walerczak and Krzysztof Krawczyk
Gliding discharge and coupled plasma-catalytic system were used for toluene conversion in a gas composition such as the one obtained during pyrolysis of biomass. The chosen catalyst was G-0117, which is an industrial catalyst for methane conversion manufactured by INS Pulawy (Poland). The effects of discharge power, initial concentration of toluene, gas flow rate and the presence of the bed of the G-0117 catalyst on the conversion of C7H8, a model tars compounds were investigated. Conversion of coluene increases with discharge power and the highest one was noted in the coupled plasma-catalytic system. It was higher than that in the homogeneous system of gliding discharge. When applying a reactor with reduced G-0117 and CO (0.15 mol%), CO2 (0.15 mol%), H2 (0.30 mol%), N2 (0.40 mol%), 4000 ppm of toluene and gas flow rate of 1.5 Nm3/h, the conversion of toluene was higher than 99%. In the coupled plasma-catalytic system with G-0117 methanation of carbon oxides was observed.
Mariusz Domagała, Hassan Momeni, Joanna Fabis-Domagała, Mariusz Krawczyk, Grzegorz Filo and Saeed Bikass
Hydraulic valves are widely used in many branches and they are still developed and improved. Due to the problem with verification of flow phenomena which appears during valves operation numerical simulations methods are tools which allows to improved valves design. This paper presents numerical simulation of fluid flow inside flow control valve.