CORRELATION BETWEEN CUTTING TEMPERATURES AND METALLURGICAL PROPERTIES OF COMPACTED GRAPHITE CAST IRONS IN THE END MILLING PROCESS

In the search for more energy-efficient internal combustion engines, the automotive companies keep pushing the working temperatures and pressures of the engines, leading to more extreme working conditions and so the necessity of new materials. Among the most promising materials for the new generations of engines is the compacted graphite cast iron, which is more wear-resistant than aluminum and tougher than gray cast iron. However, this combination of properties also leads to decreased machinability, increasing production costs and, therefore, their market competitiveness. This paper evaluated the correlation of mechanical and metallurgical properties and the cutting power and surface roughness of three grades of compacted graphite cast iron with the cutting temperature in the end milling process under different two different feed rates and cutting speeds. This analysis showed that the temperatures near the cutting zone are closely correlated to the material's mechanical properties, machining power, and resulting roughness. These results indicate that thermographic images are a good indicator of the overall correlation between the changes in material properties and the most usual machinability output parameters.

Bioelectrical impedance analysis of body composition for the anesthetic induction dose of propofol in older patients

BACKGROUND: Older people are currently the fastest growing segment of the worldwide population. The present study aimed to estimate propofol dose in older patients based on size descriptors measured by bioelectrical impedance analysis (BIA). METHODS: A cross sectional study in adult and older patients with body mass index equal to or lower than 35 kg/m2 was carried out. BIA and Clinical Frail Scale scoring were performed during pre-operative evaluation. Propofol infusion was started at 2000 mg/h until loss of consciousness (LOC) which was defined by "loss of eye-lash reflex" and "loss of response to name calling". Total dose of propofol at LOC was recorded. Propofol plasma concentration was measured using gas chromatography/ion trap-mass spectrometry. RESULTS: Forty patients were enrolled in the study. Total propofol dose required to LOC was lower in Age ≥ 65 group and a higher plasma propofol concentration was measured in this group. 60% of old patients were classified as "apparently vulnerable" or "frail" and narrow phase angle values were associated with increasing vulnerability scores. In the Age ≥ 65 group, the correlation analysis showed that the relationship between propofol dose and total body weight (TBW) scaled by the corresponding phase angle value is stronger than the correlation between propofol dose and TBW or fat free mass (FFM). CONCLUSIONS: This study demonstrates that weight-based reduction of propofol is suitable in older patients; however FFM was not seen to be more effective than TBW to predict the propofol induction dose in these patients. Guiding propofol induction dose according to baseline frailty score should also be considered to estimate individualized dosage profiles. Determination of phase angle value appears to be an easy and reliable tool to assess frailty in older patients.Financial support from the “Fundo para a Investigação e Desenvolvimento do Centro Hospitalar do Porto” is gratefully acknowledge. The medical technology and services company Medtronic™ provided BIS brain monitoring sensors. Fresenius Medical Care Portugal™ made available BCM monitor during the study period. None of the funding sources participated in the design of the study, collection, analysis and interpretation of data, or in writing of the manuscript.info:eu-repo/semantics/publishedVersio

Prevention of nasal trauma due to CPAP in a preterm newborn: case report

The administration of continuous positive airway pressure through nasal CPAP has been used in the treatment of neonatal respiratory diseases as a means of providing ventilatory support to preterm infants, producing adequate gas exchange, decreasing the complications induced by invasive mechanical ventilation and reducing bronchopulmonary dysplasia. The nasal prong is the most common device used to connect to the airways with the purpose of providing mechanical ventilation. Nasal prongs are available in different sizes and made of lightweight and flexible material. Despite its advantages, this device can cause trauma to the nose causing nasal discomfort and disfigurement. We report the case of an extremely low birth weight preterm who used a system of nasal CPAP developed by the nurses of the Neonatal Intensive Care Unit of the HCPA to protect the skin, mucosa, and nasal septum. Protection was successful

Optimization of in vitro model for growth of Gardnerella vaginalis biofilm

Bacterial vaginosis (BV) is the most common vaginal disorder in women of reproductive age. Despite its high prevalence, BV aetiology remains elusive. Recently, it was described that BV occurrence involves the presence of an adherent biofilm on vaginal epithelium, being Gardnerella vaginalis the predominant bacterial species. Furthermore, this bacterial biofilm persists on the vaginal epithelium after therapy with metronidazole, suggesting that G. vaginalis biofilm plays a key role in treatment failure and recurrence of BV. Despite the relevance of G. vaginalis biofilms in the BV pathogenesis, there has not been detailed information addressing the environmental conditions influence in G. vaginalis biofilm formation. In this sense, we designed a series of in vitro assays in order to evaluate the influence of some common culture conditions on biofilm formation of this bacterial species. Thus, we used four G. vaginalis strains isolated from women with BV and compared their biofilm-forming ability using distinct culture conditions, namely inoculum concentration, incubation period, feeding conditions and culture medium composition. Our results showed that growth conditions strongly influenced G. vaginalis biofilm formation and that biofilm formation was enhanced when starting the culture with a higher inoculum, supplemented the medium with glucose and using a fed-batch system. To conclude, this study provides new insights about optimized culture conditions for G. vaginalis biofilm formation, which is extremely important for future fundamental studies involving this bacterial community. This work was co-funded by FCT project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462), FCT Strategic Project PEst-C/SAU/UI0709/2011 and by QREN, FEDER, ON2 project (NORTE-07-0124-FEDER-000027)

Renewable fuel production from hydropyrolysis of residual biomass using molybdenum carbide-based catalysts: An analytical Py-GC/MS investigation

Fast hydropyrolysis of lignocellulosic biomass was studied by using an analytical pyrolyzer coupled with a gas chromatography/mass spectrometry set-up (Py-GC/MS). Under pure H2 stream, Canadian pinewood was rapidly heated up to 500 °C and the generated vapors passed through a catalytic bed at 500 °C. Experiments were carried out in order to compare the catalytic performance of MoC/Al2O3 catalyst to a reference catalyst based on noble metal (1.5 wt.% Pt/Al2O3). The effect of different supports (Al2O3, ZrO2 and MgO) on the carbide performance and product formation was investigated. The results showed that the performance of MoC/Al2O3 was similar to that of 1.5 wt.% Pt/Al2O3. Both of them deoxygenated the hydropyrolysis vapors and led exclusively to hydrocarbons formation. However, the proportion of aliphatic and aromatic hydrocarbons was different: MoC/Al2O3 catalyst produced more aliphatics (57%) than the Pt catalyst. The supports have demonstrated influence on the product distribution. Acidity of the support seems to play an important role in the deoxygenation of the vapors. While there was complete removal of oxygen when MoC/Al2O3 and MoC/ZrO2 were used, the same did not take place for the more basic MoC/MgO catalyst

Oxygen Increases Lung Inflammatory Response in Spontaneous One-Lung Ventilation in Rabbits: A Prospective Randomized Experimental Study

Study objective: The purpose of this study was to investigate if oxygen supplementation would increase lung inflammatory response in a spontaneous one-lung ventilation animal model, when compared to room-air oxygen fraction. Design: In vivo prospective randomized animal study Setting: University research laboratory Subjects: New Zealand rabbits Interventions: Rabbits (n=20) were randomly assigned to 2 groups (n=10 each group). Groups (OS – Oxygen Supplemented, and NOS – Non-Oxygen Supplemented) were submitted to spontaneous One-Lung Ventilation (OLV) during 60 minutes; OS group had a 2-liter/minute oxygen supplement, and NOS group was kept on roomair. Ketamine/xylazine was administered for induction and maintenance of anesthesia. One-lung ventilation was achieved by administration of air into interpleural space, and left lung collapse was visually confirmed through the center of diaphragm. Clinical monitoring and arterial blood gas analyses were performed in all rabbits. Measurements: Lung histology plates were observed under light microscopy for quantification of inflammatory response (light, moderate and severe). Main results: All subjects had at least light inflammatory response. However, rabbits submitted to oxygen supplementation had a statistically significant value for the occurrence of moderate inflammation (p<0.001). The inflammatory cells found were mainly eosinophils and neutrophils in an average proportion of 80/20. Oxygen partial pressure increased in both groups with a higher proportion in OS group (p<0.001). Conclusion: In this spontaneous OLV model, the use of oxygen supplementation was associated with a greater inflammatory response.info:eu-repo/semantics/publishedVersio

Estratégias para reduzir a mortalidade embrionária em bovinos: II. Protocolo para reduzir a mortalidade embrionária em vacas de leite e em receptoras de embrião.

A mortalidade embrionária precoce é a maior causa de perdas reprodutivas em bovinos e ela relaciona-se, principalmente com os distúrbios do reconhecimento materno da prenhez originados em disfunções do corpo lúteo ovariano. Recentemente, foi desenvolvido na Embrapa Pecuária Sudeste, um protocolo hormonal que melhora a função luteínica e permite aumentar a oportunidade para um reconhecimento materno da prenhez bem sucedido. O protocolo baseia-se na administração de hormônios reprodutivos (GnRH e hCG) em ocasiões estratégicas após a ovulação. Foram realizados dois experimentos, um com vacas leiteiras e outro com receptoras de embrião, para testar e validar o uso desse protocolo. Após a aplicação do tratamento houve aumento nas taxas de prenhez. Os resultados detalhados do uso dessa prática estão descritos no presente Boletim de Pesquisa e Desenvolvimento. O protocolo testado traduz-se numa prática pecuária de controle das funções ovariana e uterina que otimiza a eficiência reprodutiva de vacas leiteiras e de receptoras de embrião.bitstream/item/43513/1/Boletim27.pd

Fenologia de acessos do Banco de Germoplasma de mangaba da Embrapa Tabuleiros Costeiros.

bitstream/item/219048/1/BP-154-20-Ana-Ledo-v1.pd

Waste polymers recycling in high performance asphalt mixtures

Building a road pavement requires large amounts of constituent materials, whose extraction can lead to the devastation of natural resources and causes negative impacts on the environment. As aggregates comprise nearly 90% of asphalt mixtures, their partial substitution by waste thermosetting polymers (12 million tons of waste polymers are presently mislaid into landfills, every year, in Europe) can be considered as a sustainable technology, given that an equivalent performance can be assured. Thus, this study aims on evaluating possible advantages of introducing polyethylene based wastes in asphalt mixtures, namely high density polyethylene (HDPE) and cross-linked polyethylene (PEX), incorporating HDPE as a bitumen modifier and PEX as partial substitute of the aggregates. The laboratory tests carried out in this work showed that the use of HDPE significantly improves the behavior of the asphalt binder/mixture. The use of PEX considerably decreases the density of the mixtures, which can be attractive to lighten structures. The mixtures with PEX have similar performance to the conventional one in terms of water sensitivity, improving the permanent deformation resistance and reducing the temperature susceptibility. In brief, the mixtures incorporating waste polymers could be considered a good technical and environmental alternative for paving works.Portuguese Foundation for Science and Technology (FCT) in the scope of the Strategic Project UI 4047 2011‐201