Optical analysis of textured plastic substrates to be used in thin silicon solar cells

Light confinement strategies in thin-film silicon solar cells play a crucial role in the performance of the devices. In this work, the possible use of Ag-coated stamped polymers as reflectors to be used in n-i-p solar cells is studied. Different random roughnesses (nanometer and micrometer size) have been transferred on poly(methylmethacrylate) (PMMA) by hot embossing. Morphological and optical analyses of masters, stamped polymers and reflectors have been carried out evidencing a positive surface transference on the polymer and the viability of a further application in solar cells.

Anatomy, chlorophyll content and photosynthetic potential in grapevine leaves under plastic cover

The present study evaluated the anatomy, chlorophyll content and photosynthetic potential of grapevine leaves grown under plastic cover. The experiment was carried out in vineyards of Moscato Giallo cultivar covered and uncovered with plastic. A block design with 10 selected plants was used for each area (covered and uncovered). Twelve leaves (six of them fully exposed to solar radiation and six grown under shaded conditions) were collected from each area and were fixed and analyzed microscopically (thickness of the adaxial and abaxial epidermis and of the palisade and spongy parenchymas). Chlorophyll content and photosynthetic potential were determined in the vineyard at veraison and after harvest. Plastic covering increased the thickness of the palisade parenchyma in exposed and shaded leaves due to solar radiation restriction. However, the leaves from the covered vineyard did not have the same response to the restriction of solar radiation, as observed in the uncovered vineyard. The thickness of the adaxial and abaxial epidermis and of the spongy parenchyma did not vary due to solar radiation restriction. Chlorophyll content increased in the leaves of covered plants. The photosynthetic potential of the vines is not affected by solar radiation restriction imposed by plastic cover due to anatomical modification in leaves.

Exercise performed immediately after fructose ingestion enhances fructose oxidation and suppresses fructose storage.

BACKGROUND: Exercise prevents the adverse effects of a high-fructose diet through mechanisms that remain unknown. OBJECTIVE: We assessed the hypothesis that exercise prevents fructose-induced increases in very-low-density lipoprotein (VLDL) triglycerides by decreasing the fructose conversion into glucose and VLDL-triglyceride and fructose carbon storage into hepatic glycogen and lipids. DESIGN: Eight healthy men were studied on 3 occasions after 4 d consuming a weight-maintenance, high-fructose diet. On the fifth day, the men ingested an oral (13)C-labeled fructose load (0.75 g/kg), and their total fructose oxidation ((13)CO2 production), fructose storage (fructose ingestion minus (13)C-fructose oxidation), fructose conversion into blood (13)C glucose (gluconeogenesis from fructose), blood VLDL-(13)C palmitate (a marker of hepatic de novo lipogenesis), and lactate concentrations were monitored over 7 postprandial h. On one occasion, participants remained lying down throughout the experiment [fructose treatment alone with no exercise condition (NoEx)], and on the other 2 occasions, they performed a 60-min exercise either 75 min before fructose ingestion [exercise, then fructose condition (ExFru)] or 90 min after fructose ingestion [fructose, then exercise condition (FruEx)]. RESULTS: Fructose oxidation was significantly (P < 0.001) higher in the FruEx (80% ± 3% of ingested fructose) than in the ExFru (46% ± 1%) and NoEx (49% ± 1%). Consequently, fructose storage was lower in the FruEx than in the other 2 conditions (P < 0.001). Fructose conversion into blood (13)C glucose, VLDL-(13)C palmitate, and postprandial plasma lactate concentrations was not significantly different between conditions. CONCLUSIONS: Compared with sedentary conditions, exercise performed immediately after fructose ingestion increases fructose oxidation and decreases fructose storage. In contrast, exercise performed before fructose ingestion does not significantly alter fructose oxidation and storage. In both conditions, exercise did not abolish fructose conversion into glucose or its incorporation into VLDL triglycerides. This trial was registered at clinicaltrials.gov as NCT01866215.

Effect of meal ingestion on liver stiffness in patients with cirrhosis and portal hypertension.

BACKGROUND AND AIMS: Liver stiffness is increasingly used in the non-invasive evaluation of chronic liver diseases. Liver stiffness correlates with hepatic venous pressure gradient (HVPG) in patients with cirrhosis and holds prognostic value in this population. Hence, accuracy in its measurement is needed. Several factors independent of fibrosis influence liver stiffness, but there is insufficient information on whether meal ingestion modifies liver stiffness in cirrhosis. We investigated the changes in liver stiffness occurring after the ingestion of a liquid standard test meal in this population. METHODS: In 19 patients with cirrhosis and esophageal varices (9 alcoholic, 9 HCV-related, 1 NASH; Child score 6.9±1.8), liver stiffness (transient elastography), portal blood flow (PBF) and hepatic artery blood flow (HABF) (Doppler-Ultrasound) were measured before and 30 minutes after receiving a standard mixed liquid meal. In 10 the HVPG changes were also measured. RESULTS: Post-prandial hyperemia was accompanied by a marked increase in liver stiffness (+27±33%; p<0.0001). Changes in liver stiffness did not correlate with PBF changes, but directly correlated with HABF changes (r = 0.658; p = 0.002). After the meal, those patients showing a decrease in HABF (n = 13) had a less marked increase of liver stiffness as compared to patients in whom HABF increased (n = 6; +12±21% vs. +62±29%,p<0.0001). As expected, post-prandial hyperemia was associated with an increase in HVPG (n = 10; +26±13%, p = 0.003), but changes in liver stiffness did not correlate with HVPG changes. CONCLUSIONS: Liver stiffness increases markedly after a liquid test meal in patients with cirrhosis, suggesting that its measurement should be performed in standardized fasting conditions. The hepatic artery buffer response appears an important factor modulating postprandial changes of liver stiffness. The post-prandial increase in HVPG cannot be predicted by changes in liver stiffness.

Invasive populations of Senecio pterophorus are neither more productive nor more plastic than the native populations

Successful plant invaders may have specific morphological and physiological traits that promote invasion in a new habitat. The Evolution of Increased Competitive Ability (EICA) hypothesis predicts that plants released from natural enemies in the introduced habitats are more competitive and perform better than plants from the native populations. An increased phenotypic plasticity may also favour invasion because it allows plants to function under a wider range of environments. In this study we used Senecio pterophorus (Asteraceae) to test whether introduced plant populations are 1)more competitive and 2) more plastic compared with the native populations. We conducted a common garden experiment using plants from the native range (South Africa, Eastern Cape), an expanded range (South Africa, Western Cape) and two introduced ranges (Australia and Europe) under different conditions of water availability. Contrary to the EICA and the increased plasticity hypotheses, plants from the invasive and expanded populations grew less and responded less to watering than those from their native range. These results may be caused by a depleted competition as well as the presence of genetic bottlenecks in the newly invaded areas.

Creating carbon footprint calculating tool for plastic packaging products

The environmental challenges of plastic packaging industry have increased remarkably along with climate change debate. The interest to study carbon footprints of packaging has increased in packaging industry to find out the real climate change impacts of packaging. In this thesis the greenhouse gas discharges of plastic packaging during their life cycle is examined. The carbon footprint is calculated for food packaging manufactured from plastic laminate. The structure of the laminate is low density polyethylene (PE-LD) and oriented polypropylene (OPP), which have been joined together with laminating adhesive. The purpose is to find out the possibilities to create a carbon footprint calculating tool for plastic packaging and its usability in a plastic packaging manufacturing company. As a carbon footprint calculating method PAS 2050 standard has been used. In the calculations direct and indirect greenhouse gas discharges as well as avoided discharges are considered. Avoided discharges are born for example in packaging waste utilization as energy. The results of the calculations have been used to create a simple calculating tool to be used for similar laminate structures. Although the utilization of the calculating tool is limited to one manufacturing plant because the primary activity data is dependent of geographical location and for example the discharges of used energy in the plant. The results give an approximation of the climate change potential caused by the laminate. It is although noticed that calculations do not include all environmental impacts of plastic packaging´s life cycle.

The Plastic Capacity of Boiler Supporting Headers

The goal of this thesis was to make a dimensioning tool to determine the plastic capacity of the boiler supporting header. The capacity of the header is traditionally determined by using FE-method during the project phase. By using the dimensioning tool the goal is to ensure the capacity already in the proposal phase. The study began by analyzing the headers of the ongoing projects by using FE-method. For the analytical solution a plain header was analyzed without the effects of branches or lug. The calibration of parameters in the analytical solution was made using these results. In the analytical solution the plastic capacity of the plastic hinges in the header was defined. The stresses caused by the internal pressure as well as the normal and shear forces caused by the external loading reduced the plastic moment. The final capacity was determined by using the principle of virtual work. The weakening effect of the branches was taken into account by using pressure areas. Also the capacity of the punching shear was defined. The results from the FE-analyses and the analytical solution correlate with each other. The results from the analytical solution are conservative but give correct enough results when considering the accuracy of the used method.

Enhancing performance of paper coatings by tailor-made plastic pigments

The paper industry is constantly looking for new ideas for improving paper products while competition and raw material prices are increasing. Many paper products are pigment coated. Coating layer is the top layer of paper, thus by modifying coating pigment also the paper itself can be altered and value added to the final product. In this thesis, synthesis of new plastic and hybrid pigments and their performance in paper and paperboard coating is reported. Two types of plastic pigments were studied: core-shell latexes and solid beads of maleimide copolymers. Core-shell latexes with partially crosslinked hydrophilic polymer core of poly(n-butyl acrylate-co-methacrylic acid) and a hard hydrophobic polystyrene shell were prepared to improve the optical properties of coated paper. In addition, the effect of different crosslinkers was analyzed and the best overall performance was achieved by the use of ethylene glycol dimethacrylate (EGDMA). Furthermore, the possibility to modify core-shell latex was investigated by introducing a new polymerizable optical brightening agent, 1-[(4-vinylphenoxy)methyl]-4-(2-henylethylenyl)benzene which gave promising results. The prepared core-shell latex pigments performed smoothly also in pilot coating and printing trials. The results demonstrated that by optimizing polymer composition, the optical and surface properties of coated paper can be significantly enhanced. The optimal reaction conditions were established for thermal imidization of poly(styrene-co-maleimide) (SMI) and poly(octadecene-co-maleimide) (OMI) from respective maleic anhydride copolymer precursors and ammonia in a solvent free process. The obtained aqueous dispersions of nanoparticle copolymers exhibited glass transition temperatures (Tg) between 140-170ºC and particle sizes from 50-230 nm. Furthermore, the maleimide copolymers were evaluated in paperboard coating as additional pigments. The maleimide copolymer nanoparticles were partly imbedded into the porous coating structure and therefore the full potential of optical property enhancement for paperboard was not achieved by this method. The possibility to modify maleimide copolymers was also studied. Modifications were carried out via N-substitution by replacing part of the ammonia in the imidization reaction with amines, such as triacetonediamine (TAD), aspartic acid (ASP) and fluorinated amines (2,2,2- trifluoroethylamine, TFEA and 2,2,3,3,4,4,4-heptafluorobuthylamine, HFBA). The obtained functional nanoparticles varied in size between 50-217 nm and their Tg from 150-180ºC. During the coating process the produced plastic pigments exhibited good runnability. No significant improvements were achieved in light stability with TAD modified copolymers whereas nanoparticles modified with aspartic acid and those containing fluorinated groups showed the desired changes in surface properties of the coated paperboard. Finally, reports on preliminary studies with organic-inorganic hybrids are presented. The hybrids prepared by an in situ polymerization reaction consisted of 30 wt% poly(styrene- co-maleimide) (SMI) and high levels of 70 wt% inorganic components of kaolin and/or alumina trihydrate. Scanning Electron Microscopy (SEM) images and characterization by Fourier Transform Infrared Spcetroscopy (FTIR) and X-Ray Diffraction (XRD) revealed that the hybrids had conventional composite structure and inorganic components were covered with precipitated SMI nanoparticles attached to the surface via hydrogen bonding. In paper coating, the hybrids had a beneficial effect on increasing gloss levels.

Is professional recognition in plastic surgery related to activity in research

OBJECTIVE: To evaluate the relation of medical research, with the participation of prominent plastic surgeon in Congress.METHODS: We reviewed the scientific programs of the last 3 Brazilian Congress of Surgery, were selected 21 Brazilian plástic surgeons invited to serve as panelists or speakers in roundtable sessions in the last 3 congresses (Group 1). We randomly selected and paired by other members (associates) of the Brazilian Society of Plastic Surgery, with no participation in congress as speaker (Group 2). We conducted a search for articles published in journals indexed in Medline, Lilacs and SciELO for all doctors selected during the entire academic career and the last 5 years from March 2007 until March 2012. We assessed the research activity through the simple counting of the number of publications in indexed journals for each professional. The number of publications groups was compared.RESULTS: articles produced throughout career: Group 1- 639 articles (average of 30.42 items each). Group 2- 79 articles (mean 3.95 articles each). Difference between medias: p <0.001.CONCLUSION: The results demonstrate that the Brazilian Society of Plastic Surgery seeking professionals with a greater number of publications and journals of higher impact. This approach encourages new members to pursue a higher qualification, and give security to congressmen, they can rely on the existence of a technical criterion in the choice of speakers.

Plastic surgery in chest wall reconstruction: relevant aspects - case series

Objective: to discuss the participation of Plastic Surgery in the reconstruction of the chest wall, highlighting relevant aspects of interdisciplinaryness. Methods: we analyzed charts from 20 patients who underwent extensive resection of the thoracic integument, between 2000 and 2014, recording the indication of resection, the extent and depth of the raw areas, types of reconstructions performed and complications. Results: among the 20 patients, averaging 55 years old, five were males and 15 females. They resections were: one squamous cell carcinoma, two basal cell carcinomas, five chondrosarcomas and 12 breast tumors. The extent of the bloody areas ranged from 4x9 cm to 25x40 cm. In 12 patients the resection included the muscular plane. In the remaining eight, the tumor removal achieved a total wall thickness. For reconstruction we used: one muscular flap associated with skin grafting, nine flaps and ten regional fasciocutaneous flaps. Two patients undergoing reconstruction with fasciocutaneous flaps had partially suffering of the flap, solved with employment of a myocutaneous flap. The other patients displayed no complications with the techniques used, requiring only one surgery. Conclusion: the proper assessment of local tissues and flaps available for reconstruction, in addition to the successful integration of Plastic Surgery with the specialties involved in the treatment, enable extensive resections of the chest wall and reconstructions that provide patient recovery.

Europeana metadata ingestion

Francesca Morsellin esitys Europeana työpajassa 20.11.2012 Helsingissä.

Diagnose of the ingestion of Asclepias mellodora St. Hil. by sheep through microhistological analysis of their digestive contents

Asclepias mellodora St. Hil. is a native acute toxic species frequent in the grasslands of the Buenos Aires province, Argentina, whose toxicity had not been assessed until now. This study evaluates the minimal lethal dose of this species for sheep, and the possibility of microscopically recognizing its fragments in gastrointestinal contents as a complementary diagnostic tool in necropsies. Three Frisona sheep (average LW=55±4.5 kg) were dosed via an esophageal tube with each one of the following doses of asclepias: 8.0, 5.0, 2.0 and 0.8 g DM.kg LW-1. Sheep poisoned with the three higher doses died between 10 and 85 h after intoxication, but those receiving the lower dose did not. During necropsies we: 1) determined the dry weight of the contents of rumen+reticulum, omasum+abomasum, and large intestine, 2) estimated the percentages of asclepias fragments by microanalysis correcting for digestion effects on fragment recognition, and 3) calculated the total mass of asclepias in the digestive tract of each animal. For the three higher doses, the mass of asclepias identified in the total ingesta was 12.3±3.4% of the amount supplied, possibly because of the strong diarrhea its ingestion produced. The percentages of asclepias in rumen+reticulum did not differ from the average quantified for the entire tract. The results of this study indicate that the minimal lethal doses of asclepias for sheep is between 2.0 and 0.8g DM·kg LW-1, and that the microhistological analysis of the rumen+reticulum, the easiest region to sample, can be used to confirm the ingestion of this toxic species, although the estimated percentage will be not a good estimator of the ingested percentage.

Chaos and Unpredictability in the Vibration of an Elasto-Plastic Beam

This contribution discusses the nonlinear dynamics of a pin-ended elasto-plastic beam with both kinematic and isotropic hardening. An iterative numerical procedure based on the operator split technique is developed in order to deal with the nonlinearities in the equations of motion. Free and forced responses for harmonic sinusoidal and square wave excitations are investigated. Numerical simulations present many interesting behaviors such as jump phenomena, sensitivity to initial conditions, chaos and transient chaos. These results indicate that there are practical problems in predicting the response of the beam even when periodic steady state response is expected.