Foam-forming properties of Ilex paraguariensis (mate) saponin: foamability and foam lifetime analysis by Weibull equation

Saponins are natural soaplike foam-forming compounds widely used in foods, cosmetic and pharmaceutical preparations. In this work foamability and foam lifetime of foams obtained from Ilex paraguariensis unripe fruits were analyzed. Polysorbate 80 and sodium dodecyl sulfate were used as reference surfactants. Aiming a better data understanding a linearized 4-parameters Weibull function was proposed. The mate hydroethanolic extract (ME) and a mate saponin enriched fraction (MSF) afforded foamability and foam lifetime comparable to the synthetic surfactants. The linearization of the Weibull equation allowed the statistical comparison of foam decay curves, improving former mathematical approaches.

Den nya Star-Rugby-automobilen

14 x 10 cm

Uusi Star-Rugby-auto

14 x 10 cm

"Star" 4-personers Touring

kuv., 21 x 14 cm

"Star" 4-hengen Touring

kuv., 21 x 14 cm

Modeling and Parameter Estimation of Double-Star Permanent Magnet Synchronous Machines

The power rating of wind turbines is constantly increasing; however, keeping the voltage rating at the low-voltage level results in high kilo-ampere currents. An alternative for increasing the power levels without raising the voltage level is provided by multiphase machines. Multiphase machines are used for instance in ship propulsion systems, aerospace applications, electric vehicles, and in other high-power applications including wind energy conversion systems. A machine model in an appropriate reference frame is required in order to design an efficient control for the electric drive. Modeling of multiphase machines poses a challenge because of the mutual couplings between the phases. Mutual couplings degrade the drive performance unless they are properly considered. In certain multiphase machines there is also a problem of high current harmonics, which are easily generated because of the small current path impedance of the harmonic components. However, multiphase machines provide special characteristics compared with the three-phase counterparts: Multiphase machines have a better fault tolerance, and are thus more robust. In addition, the controlled power can be divided among more inverter legs by increasing the number of phases. Moreover, the torque pulsation can be decreased and the harmonic frequency of the torque ripple increased by an appropriate multiphase configuration. By increasing the number of phases it is also possible to obtain more torque per RMS ampere for the same volume, and thus, increase the power density. In this doctoral thesis, a decoupled d–q model of double-star permanent-magnet (PM) synchronous machines is derived based on the inductance matrix diagonalization. The double-star machine is a special type of multiphase machines. Its armature consists of two three-phase winding sets, which are commonly displaced by 30 electrical degrees. In this study, the displacement angle between the sets is considered a parameter. The diagonalization of the inductance matrix results in a simplified model structure, in which the mutual couplings between the reference frames are eliminated. Moreover, the current harmonics are mapped into a reference frame, in which they can be easily controlled. The work also presents methods to determine the machine inductances by a finite-element analysis and by voltage-source inverters on-site. The derived model is validated by experimental results obtained with an example double-star interior PM (IPM) synchronous machine having the sets displaced by 30 electrical degrees. The derived transformation, and consequently, the decoupled d–q machine model, are shown to model the behavior of an actual machine with an acceptable accuracy. Thus, the proposed model is suitable to be used for the model-based control design of electric drives consisting of double-star IPM synchronous machines.

Effect of calcium intake on urinary oxalate excretion in calcium stone-forming patients

Dietary calcium lowers the risk of nephrolithiasis due to a decreased absorption of dietary oxalate that is bound by intestinal calcium. The aim of the present study was to evaluate oxaluria in normocalciuric and hypercalciuric lithiasic patients under different calcium intake. Fifty patients (26 females and 24 males, 41 ± 10 years old), whose 4-day dietary records revealed a regular low calcium intake (<=500 mg/day), received an oral calcium load (1 g/day) for 7 days. A 24-h urine was obtained before and after load and according to the calciuria under both diets, patients were considered as normocalciuric (NC, N = 15), diet-dependent hypercalciuric (DDHC, N = 9) or diet-independent hypercalciuric (DIHC, N = 26). On regular diet, mean oxaluria was 30 ± 14 mg/24 h for all patients. The 7-day calcium load induced a significant decrease in mean oxaluria compared to the regular diet in NC and DIHC (20 ± 12 vs 26 ± 7 and 27 ± 18 vs 32 ± 15 mg/24 h, respectively, P<0.05) but not in DDHC patients (22 ± 10 vs 23 ± 5 mg/24 h). The lack of an oxalate decrease among DDHC patients after the calcium load might have been due to higher calcium absorption under higher calcium supply, with a consequent lower amount of calcium left in the intestine to bind with oxalate. These data suggest that a long-lasting regular calcium consumption <500 mg was not associated with high oxaluria and that a subpopulation of hypercalciuric patients who presented a higher intestinal calcium absorption (DDHC) tended to hyperabsorb oxalate as well, so that oxaluria did not change under different calcium intake.

Possibility of press forming wood films into primary packaging

In recent times the packaging industry is finding means to maximize profit. Wood used to be the most advantageous and everyday material for packaging, worktables, counters, constructions, interiors, tools and as materials and utensils in the food companies in the world. The use of wood has declined vigorously, and other materials like plastic, ceramic, stainless steel, concrete, and aluminum have taken its place. One way that the industry could reduce its cost is by finding possibilities of using wood for primary packaging after which it can be safely recycled or burned as a carbon source for energy. Therefore, the main objective of this thesis is to investigate the possibility of press-forming a wood film into primary packaging. In order to achieve the stated objectives, discussion on major characteristics of wood in terms of structure, types and application were studied. Two different wood species, pine and birch were used for the experimental work. These were provided by a local carpentry workshop in Lappeenranta and a workshop in Ruokolahti supervised by Professor Timo Kärki. Laboratory tests were carried out at Lappeenranta University of Technology FMS workshop on Stenhøj EPS40 M hydraulic C-frame press coupled with National Instruments VI Logger and on the Adjustable packaging line machine at LUT Packaging laboratory. The tests succeeded better on the LUT packaging line than on the Stenhoj equipment due to the integrated heating system in the machine. However, there is much work to be done before the quality of a tray produced from the wood film is comparable to that of the wood plastic composite tray.

Forming i barnehagen i lys av Reggio Emilias atelierkultur

Forming (Arts and crafts) and children’s creative action with materials and tools are less in use in the kindergarten than before. Political focus on children’s early learning has led to shifts in kindergartens toward other specific disciplines, and requirements for individual testing also of the smallest children’s competencies within these. Kindergarten teachers, educators, researchers and participants in social debate have pointed out that there are epistemological contradictions in descriptions of kindergarten quality as well as between current kindergarten policy documents and requirements for the kindergartens’ staff. Meanwhile, the content and methods in many kindergartens are inspired by practice and philosophy in the municipal kindergartens in Reggio Emilia, Italy. Correlation between kindergartens’ formingprojects and experiences from Reggio Emilia is actualized in particular through the workshop and the studio’s role in children’s learning processes. One starting point for the thesis’ problem area is a documented need for more knowledge about kindergarten’s educational content. The overarching goal of the thesis is to develop new knowledge about how learning takes place in kindergarten through examining the field of forming in kindergartens inspired by Reggio Emilia’s atelier culture. The thesis is theoretically anchored within pragmatism, and ties kindergarten’s aesthetic operations with materials and tools to socio-cultural perspective, social constructivism and post humanistic theory. The empirical material is obtained through a qualitative study with ethnography as methodological approach. The fieldwork is conducted in kindergarten, with two leading research questions: 1) How is atelierism perceived and unfolded in Norwegian Reggio Emilia-inspired kindergartens, and 2) how is forming perceived and unfolded in Norwegian Reggio Emilia-inspired kindergartens. A comprehensive and multifaceted material is analyzed, and the results are presented in the form of three themes: The physical environment, Relations and actions in interplay, and Expression forms and forms of expression. Each of these topics are supported by examples from kindergartens’ adult voices and the constructed empirical material. Insights into how learning takes place in the kindergarten subject of forming with inspiration from the Reggio Emilia atelier culture is discussed in the tension between educational philosophy, Nordic kindergarten tradition and neoliberal trends that kindergarten teachers must adhere to. Learning potentials in children’s opportunities for action in forming in light of the atelier appears in the results of the empirical study. The educational context described is characterized by experimental and playful actions where children’s sensations, curiosity and resistance are interacting with the identity of materials and tools. The results imply aesthetic, ethical, democratic and ecological reflections, which are also valid on a practical action level. The thesis contributes to description and understanding of kindergarten’ content and young children’s learning, the importance of atelier culture as inspiration for the kindergarten, and the further development of methodology and documentation of knowledge expressions.

Neutralization of the edema-forming, defibrinating and coagulant effects of Bothrops asper venom by extracts of plants used by healers in Colombia

We determined the neutralizing activity of 12 ethanolic extracts of plants against the edema-forming, defibrinating and coagulant effects of Bothrops asper venom in Swiss Webster mice. The material used consisted of the leaves and branches of Bixa orellana (Bixaceae), Ficus nymphaeifolia (Moraceae), Struthanthus orbicularis (Loranthaceae) and Gonzalagunia panamensis (Rubiaceae); the stem barks of Brownea rosademonte (Caesalpiniaceae) and Tabebuia rosea (Bignoniaceae); the whole plant of Pleopeltis percussa (Polypodiaceae) and Trichomanes elegans (Hymenophyllaceae); rhizomes of Renealmia alpinia (Zingiberaceae), Heliconia curtispatha (Heliconiaceae) and Dracontium croatii (Araceae), and the ripe fruit of Citrus limon (Rutaceae). After preincubation of varying amounts of each extract with either 1.0 µg venom for the edema-forming effect or 2.0 µg venom for the defibrinating effect, the mixture was injected subcutaneously (sc) into the right foot pad or intravenously into the tail, respectively, to groups of four mice (18-20 g). All extracts (6.2-200 µg/mouse) partially neutralized the edema-forming activity of venom in a dose-dependent manner (58-76% inhibition), with B. orellana, S. orbicularis, G. panamensis, B. rosademonte, and D. croatii showing the highest effect. Ten extracts (3.9-2000 µg/mouse) also showed 100% neutralizing ability against the defibrinating effect of venom, and nine prolonged the coagulation time induced by the venom. When the extracts were administered either before or after venom injection, the neutralization of the edema-forming effect was lower than 40% for all extracts, and none of them neutralized the defibrinating effect of venom. When they were administered in situ (sc at the same site 5 min after venom injection), the neutralization of edema increased for six extracts, reaching levels up to 64% for C. limon.

POD-1/Tcf21 overexpression reduces endogenous SF-1 and StAR expression in rat adrenal cells

During gonad and adrenal development, the POD-1/capsulin/TCF21transcription factor negatively regulates SF-1/NR5A1expression, with higher SF-1 levels being associated with increased adrenal cell proliferation and tumorigenesis. In adrenocortical tumor cells, POD-1 binds to the SF-1 E-box promoter region, decreasing SF-1 expression. However, the modulation of SF-1 expression by POD-1 has not previously been described in normal adrenal cells. Here, we analyzed the basal expression of Pod-1 and Sf-1 in primary cultures of glomerulosa (G) and fasciculata/reticularis (F/R) cells isolated from male Sprague-Dawley rats, and investigated whether POD-1 overexpression modulates the expression of endogenous Sf-1 and its target genes in these cells. POD-1 overexpression, following the transfection of pCMVMycPod-1, significantly decreased the endogenous levels of Sf-1 mRNA and protein in F/R cells, but not in G cells, and also decreased the expression of the SF-1 target StAR in F/R cells. In G cells overexpressing POD-1, no modulation of the expression of SF-1 targets, StAR and CYP11B2, was observed. Our data showing that G and F/R cells respond differently to ectopic POD-1 expression emphasize the functional differences between the outer and inner zones of the adrenal cortex, and support the hypothesis that SF-1 is regulated by POD-1/Tcf21 in normal adrenocortical cells lacking the alterations in cellular physiology found in tumor cells.

Effect of process variables on the osmotic dehydration of star-fruit slices

The objective of this work was to study the effect of blanching and the influence of temperature, solution concentration, and the initial fruit:solution ratio on the osmotic dehydration of star-fruit slices. For blanching, different concentrations of citric and ascorbic acids were studied. The samples immersed in 0.75% citric acid presented little variation in color in relation to the fresh star-fruit. Osmotic dehydration was carried out in an incubator with orbital shaking, controlled temperature, and constant shaking at 120 rpm. The influence of process variables was studied in trials defined by a complete 23 central composite design. In general, water loss and solids gain were positively influenced by temperature and by solution concentration. Nevertheless, lower temperatures reduced water loss throughout the osmotic dehydration process. An increase in the amount of dehydrating solution (initial fruit:solution ratio) slightly influenced the evaluated responses. The process carried out at 50 ºC with a solution concentration of 50% resulted in a product with lower solids gain and greater water loss. Under these conditions, blanching minimized the effect of the osmotic treatment on star-fruit browning, and therefore the blanched fruits showed little variation in color in relation to the fresh fruit.