Application of the continuum damage mechanics model in the three point bending test of Ti-6Al-4V titanium alloy specimens

One of the most important and challenging activities in the simulation of the mechanical behaviour of materials is the prediction of the failure phenomena. If well calibrated, damage models can simulate and predict the failure of materials in a generalized way allowing the replication of not only the calibration tests themselves but also of different loading cases. Generally damage models can be categorized into three different groups including phenomenological models, porosity models and continuum damage mechanics (CDM) models. Different CDM models have been proposed by researchers and these models have been applied in diverse loading conditions, geometries and materials. However the limitations and advantages of the CDM models are still not completely explored in the application areas. In this paper, a CDM model, (previously calibrated with round smooth specimen) has been applied in a three-point bending test model in order to simulate the correlated experiment. Specifically, the CDM framework has been applied in a finite element model and the obtained results have been compared with the experimental data. The tested material is Ti-6Al-4V titanium alloy, which is a widely used material in the aerospace industry because of its high strength and low density. Load-displacement data in the experiments and numerical simulations are the main results, which have been compared. Therefore, the ability of the CDM model to simulate the three point bending test has been investigated and the results are discussed

A History of The Mid-America Conference on History

After conferring with colleagues, I created the Mid-America Conference on History (MACH) in 1977. At the time I was an associate professor of history at Southwest Missouri State University in Springfield, Missouri. The MACH sought to mirror other regional ventures such as the Northern Great Plains History Conference, which was established in 1966. The motivation was similar for I had also experienced the high costs of attending national meetings of the Organization of American Historians or the American Historical Association held in cities such as New York, Philadelphia, or Washington, D.C. More importantly, the opportunity to present at national meetings proved difficult for junior faculty, especially from less prominent institutions. My vision was to create a smaller version of the Southern Historical Association (SHA) conference that drew primarily from middle America and that shared the same professional standards and intimate environment of the SHA

A History of The Missouri Conference on History, 1959-2016

The Missouri Conference on History (MCOH) emerged in 1959 and has continued without missing a year, despite undergoing organizational changes over time. Many individuals have contributed to make it one of the most successful state conferences ever. This is a story worth telling, especially at time when many people are reconsidering the history of the Midwest and how to support the infrastructure necessary to promote the study of that history

Perioperative hemodynamic goal-directed therapy and mortality: a systematic review and meta-analysis with meta-regression

INTRODUCTION: Recent data found that perioperative goal directed therapy (GDT) was effective only in higher control mortality rates (> 20%) with a relatively high heterogeneity that limited the strength of evidence. The aim of the present meta-analysis was to clearly understand which high risk patients may benefit of GDT.EVIDENCE ACQUISITION: Systematic review of randomized controlled trials with meta-analyses, including a meta-regression technique. MEDLINE, EMBASE, and The Cochrane Library databases were searched (1980-January 2015). Trials enrolling adult surgical patients and comparing the effects of GDT versus standard hemodynamic therapy were considered. The primary outcome measure was mortality. Data synthesis was obtained by using Odds Ratio (OR) with 95% confidence interval (CI) by random-effects model.EVIDENCE SYNTHESIS: Fifty eight studies met the inclusion criteria (8171 participants). Pooled OR for mortality was 0.70 (95% CI 0.56-0.88, P= 0.002, no statistical heterogeneity). GDT significantly reduced mortality when it is > 10% in control group (OR 0.43, 95% CI 0.30-0.61, P< 0.00001). The meta-regression model showed that the cut off of 10% of mortality rate in control group significantly differentiates 43 studies from the other 15, with a regression coefficient b of -0.033 and a P value of 0.0001. The significant effect of GDT was driven by high risk of bias studies (OR 0.48, 95% CI 0.34-0.67, P< 0.0001).CONCLUSIONS: The present meta-analysis, adopting the meta-regression technique, suggests that GDT significantly reduces mortality even when the event control rate is > 10%

satellite data analysis for identification of groundwater salinization effects on coastal forest for monitoring purposes

Abstract. In the phreatic aquifer below the San Vitale pinewood (Ravenna, Italy), natural and anthropogenic land subsidence, the low topography and the artificial drainage system have led to widespread saltwater intrusion. Since changes in the groundwater concentration induce variations in the vegetation properties, recognizable by different spectral bands, a comparison between satellite images, ASTER and Worldview-2, was made using the NDVI. The aim was to identify the portions of pinewood affected by salinization through a procedure that could reduce the expensive and time consuming ground monitoring campaigns. Moreover, the Worldview-2 high resolutions were used to investigate the Thermophilic Deciduous Forest (TDF) spectral behaviour without the influence of the allochthonous Pinus pinea species that is scattered throughout the pinewood. The NDVI, calculated with traditional bands, identified the same stressed areas using both satellite data. Instead, the new Red-Edge band of the Worldview-2 image allowed a greater correlation between NDVI and groundwater salinity

Redesigning Public Speaking: A Case Study in the Use of Instructional Design to Create the Interchange Model

This case study describes the redesign of Public Speaking at a Research I institution. An instructional analysis revealed strengths of and concerns about the existing model--large lecture with small lab sections. Criteria for a new model emerged from that analysis, all of which hinged on an overarching goal: The course should incorporate learning theory and disciplinary theory and should result in student learning, student skill development, and enhanced satisfaction among stakeholders. The Interchange Model, which included some online delivery, was developed to meet identified needs and was fleshed out with course materials and semester plans. The model was piloted and then fully implemented with positive results

A Deep Learning Method for Automatic Identification of Drusen and Macular Hole from Optical Coherence Tomography

Deep Learning methods have become dominant in various fields of medical imaging, including ophthalmology. In this preliminary study, we investigated a method based on Convolutional Neural Network for the identification of drusen and macular hole from Optical Coherence Tomography scans with the aim to assist ophthalmologists in diagnosing and assessing retinal diseases

SATELLITE AND UNMANNED AERIAL VEHICLE DATA FOR THE CLASSIFICATION OF SAND DUNE VEGETATION

Within coastal systems, sand dunes are the only natural barriers able to counteract erosive processes. Since their equilibrium is often threatened by human activities and high vulnerability of the coastal environment, dunes require increasing attention and specific monitoring. Located between the mainland and the sea, dunes are unique residue habitats for some plant and animal species. In particular, their vegetation is important because it has a consolidation function and promotes the vertical dune accretion. A georeferenced vegetation classification can be useful to define the advancements or erosion stage of the dune, usually based only on the geometric reconstruction. The proposed study aims to compare the classifications performed with some combinations of two of the last generation sensors and traditional image processing techniques. High spectral resolution satellite image (WorldView-2) and a multispectral orthophoto, obtained from data acquired by an unmanned aerial vehicle, were used. Objects and pixel algorithms were applied and the results were compared by a statistical test. Using the same bands, the findings show that both data are suitable for monitoring the evolutionary dune status. Specifically, the WorldView-2 pixel-based classification and UAV object-based classification provide the same accurate results

Vasopressor-Sparing Action of Methylene Blue in Severe Sepsis and Shock: A Narrative Review

Shock is a serious acute circulatory failure leading to inadequate oxygen delivery to the cells. Its treatment is mainly based on circulating fluid optimization, and vasopressors to provide an adequate mean arterial pressure and microcirculatory flow. Norepinephrine is the drug of choice, but high dosages may be responsible for several side effects, including increased myocardial oxygen consumption, dysrhythmias, and peripheral and organ ischemia. Moreover, some patients are “non-responders” to first-line norepinephrine treatment. Hence, other drugs have been proposed to reach and maintain the hemodynamic target. In general, they are described as catecholamine-sparing agents. Among others, the most used are vasopressin, corticosteroids, and angiotensin II. Methylene blue (MB) represents a further option, even though its use is still a topic of controversy. This review article tries to summarize what is known and unknown about the actions of MB in patients in shock. It reduces excessive production of nitric oxide via blockade of guanylate cyclase in shock states. At present, it appears the MB provides positive results in septic shock, if administered early. Further randomized controlled trials are warranted regarding its use to provide more precise indications to physicians involved in the treatment of such patients

Post-operative morbidity following pancreatic duct occlusion without anastomosis after pancreaticoduodenectomy: a systematic review and meta-analysis

Background: Pancreatic duct occlusion (PDO) without anastomosis is a technique proposed to mitigate the clinical consequences of postoperative pancreatic fistulas (POPF) after pancreaticoduodenectomy. The aim of this study was to appraise the morbidity following PDO through a systematic review and meta-analysis. Methods: A systematic search of MEDLINE, Embase, and Web Of Science identified studies reporting outcomes of PDO following pancreaticoduodenectomy. Pooled prevalence rates of postoperative complications and mortality were computed using random-effect modeling. Meta-regression analyses were performed to examine the impact of moderators on the overall estimates. Results: Sixteen studies involving 1000 patients were included. Pooled postoperative mortality was 2.7%. A POPF was reported in 29.7% of the patients. Clinically relevant POPFs occurred in 13.5% of the patients, while intra-abdominal abscess and haemorrhages occurred in 6.7% and 5.5% of the patients, respectively. Re-operation was necessary in 7.6% of the patients. Postoperatively new onset diabetes occurred in 15.8% of patients, more frequently after the use of chemical substances for PDO (p = 0.003). Conclusions: PDO is associated with significant morbidity including new onset of post-operative diabetes. The risk of new onset post-operative diabetes is associated with the use of chemical substance for PDO. Further evidence is needed to evaluate the potential benefits of PDO in patients at high risk of POPF