Effect of Ultrasonic Treatment in the Static and Dynamic Mechanical Behavior of AZ91D Mg Alloy

The present study evaluates the effect of high-intensity ultrasound (US) in the static and dynamic mechanical behavior of AZ91D by microstructural modification. The characterization of samples revealed that US treatment promoted the refinement of dendrite cell size, reduced the thickness, and changed the β-Mg17Al12 intermetallic phase to a globular shape, promoted its uniform distribution along the grain boundaries and reduced the level of porosity. In addition to microstructure refinement, US treatment improved the alloy mechanical properties, namely the ultimate tensile strength (40.7%) and extension (150%) by comparison with values obtained for castings produced without US vibration. Moreover, it is suggested that the internal friction, enhanced by the reduction of grain size, is compensated by the homogenization of the secondary phase and reduction of porosity. It seems that by the use of US treatment, it is possible to enhance static mechanical properties without compromising the damping properties in AZ91D alloys.This research was supported by FEDER/COMPETE funds and by national funds through FCT-Portuguese Foundation for Science and Technology and was developed on the aim of Post-Doctoral grant SFRH/BPD/76680/2011. Also, this work has been supported by the FCT in the scope of the project: UID/EEA/04436/2013.info:eu-repo/semantics/publishedVersio

Correlating low energy impact damage with changes in modal parameters: a preliminary study on composite beams

This paper is an experimental study of the effects of multi-site damage on the vibration response of a composite beam damaged by low energy impact. The variation of the modal parameters with different levels of impact energy and density of impact is studied. Specimens are impacted symmetrically in order to induce a global rate of damage. A damage detection tool Damage Index is introduced in order to verify the estimation of damping ratios. Design of Experiments is used to establish the sensitivity of both energy of impact and density of damage. The DOE analysis results (using natural frequency only) indicate that impact energy for 2nd, 3rd and 4th bending modes is the most significant factor contributing to the changes in the modal parameters for this kind of symmetrical dynamic test

The association between complications and quality of life after mastectomy and breast reconstruction for breast cancer.

Medical treatment for breast cancer is associated with substantial toxicity and patient burden. There is less known about the impact of surgical complications. Understanding this impact could provide important information for patients when they are considering surgical options. Between 2008 and 2009, the UK National Mastectomy and Breast Reconstruction Audit recorded surgical complications for a prospective cohort of 17,844 women treated for breast cancer at 270 hospitals; 6405 of these women were surveyed about their quality of life 18 months after surgery. Breast appearance, emotional well-being, and physical well-being were quantified on 0- to 100-point scales. Linear multiple regression models, controlling for a range of baseline prognostic factors, were used to compare the scores of patients who had complications with the scores of those who did not. The overall complication rate was 10.2%. Complications were associated with little or no impairment in women undergoing mastectomy without reconstruction or with delayed reconstruction. The association was much larger for flap-related complications suffered during immediate reconstruction. The breast-appearance scores (adjusted mean difference, -23.8; 95% confidence interval [CI], -31.0 to -16.6) and emotional well-being scores (adjusted mean difference, -14.0; 95% CI, -22.0 to -6.0) of these patients were much lower than those of any other patient group. Implant-related complications were not associated with a lower quality of life in any surgical group. There is a strong case for prospectively collecting flap-complication rates at the surgeon and surgical unit level and for allowing patients to access these data when they make choices about their breast cancer surgery. Cancer 2017. © 2017 American Cancer Society

Učinak upotrebe urea-formaldehida modificiranog ekstraktima na emisiju formaldehida furnirske ploče

Formaldehyde-based adhesives are used in the forestry industry. This is because formaldehyde is inexpensive, easy to use and resistant to moisture; it also has particular mechanical effects. Formaldehyde has both advantages and disadvantages. It is known that various diseases such as lung cancer occur in humans as a result of the release of formaldehyde into the air during and after board production. In this study, a urea formaldehyde glue mixture was prepared by using four different fillers (extract of maritime pine (Pinus pinaster) and elm (Ulmus glabra) bark, extract of hazelnut (Corylus avellana) husk and acorn tannins) at two different ratios. The bonding shear strength of pine (Pinus sylvestris) and spruce (Picea orientalis) plywood produced with urea formaldehyde adhesive was tested according to EN 314-1 standard. All plywood, except the plywood with acorn tannin, met the requirements of the standard. A formaldehyde emission test of the plywood was carried out in accordance with EN 713-3 standard. With this approach, it is possible to quickly determine formaldehyde emissions. Experimental results were obtained for subsequent measurements, including chamber tests. It was observed that the elm bark extract reduced the formaldehyde emission of pine plywood by 40 %, while other fillers reduced it by 3-37 %.U drvoprerađivačkoj industriji upotrebljavaju se ljepila na bazi formaldehida zato što je taj aldehid jeftin, jednostavan za uporabu, otporan na vlagu i ima posebne mehaničke učinke. Formaldehid ima određenih prednosti i nedostataka. Poznato je da se u ljudi koji rade u drvoprerađivačkoj industriji pojavljuju različite bolesti poput raka pluća, što može biti posljedica ispuštanja formaldehida u zrak tijekom i nakon proizvodnje ploča. Za ovo je istraživanje pripremljena smjesa urea-formaldehidnog ljepila dodavanjem četiriju različitih punila: ekstrakta kore primorskog bora (Pinus pinaster) i brijesta (Ulmus glabra), ekstrakta ljuske lješnjaka (Corylus avellana) i tanina žira u dva različita omjera. Posmična čvrstoća furnirske ploče od borovine (Pinus sylvestris) i smrekovine (Picea orientalis), proizvedene uporabom urea-formaldehidnog ljepila, ispitana je prema normi EN 314-1. Sve furnirske ploče, osim onih s taninom iz žira, zadovoljile su zahtjeve norme. Ispitivanje emisije formaldehida iz furnirskih ploča provedeno je prema normi EN 713-3. Tim je pristupom moguće brzo odrediti emisije formaldehida. Dobiveni su eksperimentalni rezultati za naknadna mjerenja, uključujući ispitivanje u komori. Primijećeno je da je ekstrakt kore brijesta smanjio emisiju formaldehida furnirske ploče od borovine za 40 %, dok su ostala punila smanjila tu emisiju za 3 – 37 %

The effects of perceived organisational support on employees\u27 affective outcomes: evidence from the hotel industry

Previous studies mainly analysed the relationship between perceived organisational support and organisational commitment in a direct way. Limited studies of tourism, however, have found that job satisfaction is a mediator variable in the relationship between perceived organisational support and organisational commitment. The aim of this study is, (i) to analyse the effect of organisational support on job satisfaction, (ii) to analyse the effect of organisational support on the dimensions of organisational commitment, (iii) to analyse the effect of job satisfaction on the dimensions of organisational commitment, and (iv) to analyse the mediating effect of job satisfaction on the relationship between perceived organisational support and dimensions of organisational commitment based on an empirical study. The relationship between the variables was analysed by using a multivariate data analysis. Besides this, in the study, the mediating effect of job satisfaction on the relationship between perceived organisational support and the dimensions of organisational commitment was analysed by the technique recommended by Baron and Kenny (1986) and the Sobel test. The findings indicated that perceived organisational support had a significant positive effect on job satisfaction, affective, normative and continuous commitment. Job satisfaction had a significant positive effect on affective, normative and continuous commitment as well. Besides this, job satisfaction played a partial mediating role between perceived organisational support and dimensions of organisational commitment. Implications were presented for hotel managers who want to keep and encourage their employees to work in the hotel industry

Skin avulsion injury during endotracheal tube extubation – case report of an unusual complication

We report a geriatric case with a full-thickness skin avulsion injury during extubation due to a tube securing tape used to fixate the endotracheal tube. The avulsed skin was sutured back to its original place. Based on this single geriatric patient, we recommend anesthesiologists/anesthetists and surgeons be aware of the potential risk of avulsing the skin with tape during a standard extubation procedure. This may especially occur in geriatric patients who have age related changes as decreased elasticity and resistance to shearing forces that predispose the skin to get traumatized easily

Bio-efficacy of hydroxy-selenomethionine as a selenium supplement in pregnant dairy heifers and on the selenium status of their calves

This study aimed to determine the effects of supplementing pregnant heifers with the organic selenium source 2-hydroxy-4-methylselenobutanoic acid (HMSeBA) during last eight weeks of pregnancy on dam and calf Se status. A total of 42 in-calf heifers were recruited to the study and randomly allocated to one of three treatments; a negative control (Con), sodium selenite (NaSe) or HMSeBA. Animals were blocked by body weight, body condition score, and expected calving date prior to treatment allocation. Following enrollment all animals underwent a seven week wash-out period after which they received their respective supplements, topped dressed daily onto a basal diet for the last eight weeks of pregnancy. Heifer blood samples were taken at weekly intervals from enrollment until two weeks before expected calving date, and as soon as possible after calving for determination of whole blood glutathione peroxidase activity (GSH-Px) and plasma selenium (Se) and malondealdehyde (MDA) concentrations. Selenized amino acids were determined in plasma samples taken at three weeks pre-calving. A colostrum sample was taken as close to parturition as possible for determination of colostrum total Se, selenized amino acid, and Immunoglobulin G (IgG) concentration. Calves were blood sampled as close to birth as possible for determination of whole blood GSH-Px activity and plasma Se and MDA concentration. Differences in whole blood GSH-Px activity did not become apparent until calving; GSH-Px activity was lowest in Con heifers (P < 0.05) but similar between NaSe and HMSeBA. Plasma Se was lowest in unsupplemented heifers and greatest in those supplemented with HMSeBA (P < 0.001) and this was attributable to greater selenomethionine concentrations in the plasma of HMSeBA heifers (P < 0.01). Colostrum Se was lowest in Con heifers and greatest in HMSeBA (P < 0.001), the greater Se concentration of HMSeBA heifers was attributable to a greater proportion of total Se comprising selenocysteine (P = 0.061), the reason for this is not known. There was no effect of supplementation on colostrum IgG concentration. Plasma Se was lowest in those calves born to Con heifers and greatest in those born to HMSeBA heifers (P < 0.001). There were no effects of treatment on calf whole blood GSH-Px activity or plasma MDA concentration. The enhanced Se status associated with HMSeBA supplementation is likely a consequence of selenomethionine supply and may confer benefits to both the dam and her calf post-partum

Differential response to resistance training in CHF according to ACE genotype

The Angiotensin Converting Enzyme (ACE) gene may influence the risk of heart disease and the response to various forms of exercise training may be at least partly dependent on the ACE genotype. We aimed to determine the effect of ACE genotype on the response to moderate intensity circuit resistance training in chronic heart failure (CHF) patients. Methods: The relationship between ACE genotype and the response to 11 weeks of resistance exercise training was determined in 37 CHF patients (New York Heart Association Functional Class=2.3±0.5; left ventricular ejection fraction 28±7%; age 64±12 years; 32:5 male:female) who were randomised to either resistance exercise (n=19) or inactive control group (n=18). Outcome measures included V˙ O2peak, peak power output and muscle strength and endurance. ACE genotype was determined using standard methods. Results: At baseline, patients who were homozygous for the I allele had higher V˙ O2peak (p=0.02) and peak power (p=0.003) compared to patients who were homozygous for the D allele. Patients with the D allele, who were randomised to resistance training, compared to non-exercising controls, had greater peak power increases (ID pb0.001; DD pb0.001) when compared with patients homozygous for the I allele, who did not improve. No significant genotype-dependent changes were observed in V˙ O2peak, muscle strength, muscle endurance or lactate threshold. Conclusion: ACE genotype may have a role in exercise tolerance in CHF and could also influence the effectiveness of resistance training in this condition

Bioaccumulation monitoring of chemical contaminants in mussels Mytilus galloprovincialis from the southern coast of the Marmara Sea, Turkey

Mytilus galloprovincialis, the Mediterranean mussel, is an important shellfish species that constitutes the majority of production and consumption among bivalve mollusks in Turkey. Since shellfish can accumulate toxic chemicals from seawater, it is important to monitor bioaccumulation from their natural beds. For this reason, in this study, the aim was to monitor the levels of dioxins and dioxin-like polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and toxic metals (Pb, Cd, and Hg) in M. galloprovincialis collected from the southern coast of the Marmara Sea from 2014 to 2017. According to the results, the maximum levels of dioxins, PAHs, and toxic metals during the monitoring period were determined as 0.30 pg/g, 2.52 mg/kg, and 0.43-0.34-0.76 (Pb-Cd-Hg) mg/kg, respectively. Dioxin, PAHs, and toxic metal amounts in mussel samples were determined to be below the threshold levels enforced by the European Commission. The highest benzo(a)pyrene and total PAHs were determined in winter 2015, while toxic metals, dioxins, and dioxin-like PCBs (WHO/PCDD/F-PCB-TEQ) were higher in autumn 2014 than the rest of the sampling period. In conclusion, toxic chemicals monitored in M. galloprovincialis were found at low concentrations from the point of view of food safety. However, monitoring of these or other toxic chemicals should be repetitively performed in the future to ensure food safety in aquatic animals

El efecto de la diversidad e independencia del consejo de administración en la existencia de un comité de sostenibilidad

The purpose of this study was to enhance the understanding of the factors determining the existence of a “Corporate Social Responsibility” (CSR) committee on the board. Focusing the attention on board composition, this paper explores how female directors influence the existence of a CSR committee, and how this effect can be moderated by the independence of board members. To be able to test the aims of the study, an international sample of analysis of 4,168 firm-year observations from 2012 to 2016 was used, proposing several models for panel data. The findings revealed that female directors exert a positive influence on the existence of a CSR committee, although this commitment is limited when in addition to women, they are independent directors on the board. Therefore, it can be said that board gender diversity and board independence are not complementary mechanisms that favour the existence of a specific committee on CSR. This study is one of a limited number of studies to focus on the antecedents of existence of a CSR committee in firms. In addition, the study obtains benefit by considering the independence of board of directors as a moderating variable on the relationship female directors-sustainability. In contrast with previous studies based on the cross-sectional data from a single country, the data set of the current study includes a panel data comprising of a period between 2012 and 2016 and an international sample from 44 countries in six continents.El objetivo de este estudio es reforzar el conocimiento sobre los factores que determinan la existencia de un comité de sostenibilidad en el consejo de administración. Centrando el interés en la composición del Consejo, este trabajo explora como las mujeres consejeras influyen en la existencia de un comité de sostenibilidad; además, este estudio también analiza si este efecto puede ser moderado por la independencia de los consejeros. Con el objetivo de testar estos objetivos, se hace uso de una muestra de análisis internacional compuesta por 4.168 observaciones para el periodo 2012-2016 proponiendo diversos modelos de regresión para datos de panel. Los resultados confirman que las mujeres consejeras ejercen un efecto positivo, favoreciendo la creación de un comité de sostenibilidad, aunque este compromiso está limitado cuando además de mujeres, éstas son consejeras independientes. Por lo tanto, podemos decir que la diversidad de género y la independencia no actúan como mecanismos complementarios que favorezcan la creación de un comité de sostenibilidad. Este estudio es uno de los pocos estudios previos que se centran en analizar los antecedentes de la existencia de un comité de sostenibilidad. Además, este trabajo añade valor a la evidencia previa, considerando la independencia del consejo como un factor de moderación a tener en cuenta en la relación mujeres- sostenibilidad. A diferencia de estudios previos centrados en un único país, el conjunto de datos analizados en este estudio comprende una base de datos de panel de empresas para el periodo comprendido entre 2012 y 2016 y una muestra internacional de operando en 44 países en seis continentes