Non-Destructive Inspection of Impact Damage in Composite Aircraft Panels by Ultrasonic Guided Waves and Statistical Processing.

This paper discusses a non-destructive evaluation (NDE) technique for the detection of damage in composite aircraft structures following high energy wide area blunt impact (HEWABI) from ground service equipment (GSE), such as heavy cargo loaders and other heavy equipment. The test structures typically include skin, co-cured stringers, and C-frames that are bolt-connected onto the skin with shear ties. The inspection exploits the waveguide geometry of these structures by utilizing ultrasonic guided waves and a line scan approach. Both a contact prototype and a non-contact prototype were developed and tested on realistic test panels subjected to impact in the laboratory. The results are presented in terms of receiver operating characteristic curves that show excellent probability of detection with low false alarm rates for defects located in the panel skin and stringers

A match coefficient approach for damage imaging in structural components by ultrasonic synthetic aperture focus

Ultrasonic Synthetic Aperture Focus (SAF) techniques are commonly used to image structural defects. In this paper, a variation of SAF based on ideas borrowed from Matched Field Processing (MFP) is evaluated to reduce artifacts and sidelobes of the resulting images. In particular, instead of considering the full RF ultrasonic waveforms for the SAF time backpropagation, only selected features from the waveforms are utilized to form a “data vector” and a “replica” (expected) vector of MFP. These vectors are adaptive for the pair of transmitter-receiver and the focus point. The image is created as a matched filter between these two vectors. Experimental results are shown for an isotropic and homogenous metallic plate with simulated defects, probed by six piezoelectric patches used as receivers or transmitters

Routine repeat head CT may not be necessary for patients with mild TBI.

Background:Routine repeat cranial CT (RHCT) is standard of care for CT-verified traumatic brain injury (TBI). Despite mixed evidence, those with mild TBI are subject to radiation and expense from serial CT scans. Thus, we investigated the necessity and utility of RHCT for patients with mild TBI. We hypothesized that repeat head CT in these patients would not alter patient care or outcomes. Methods:We retrospectively studied patients suffering from mild TBI (Glasgow Coma Scale (GCS) score 13-15) and treated at the R Adams Cowley Shock Trauma Center from November 2014 through January 2015. The primary outcome was the need for surgical intervention. Outcomes were compared using paired Student's t-test, and stratified by injury on initial CT, GCS change, demographics, and presenting vital signs (mean ± SD). Results:Eighty-five patients met inclusion criteria with an average initial GCS score=14.6±0.57. Our center sees about 2800 patients with TBI per year, or about 230 per month. This includes patients with concussions. This sample represents about 30% of patients with TBI seen during the study period. Ten patients required operation (four based on initial CT and others for worsening GCS, headaches, large unresolving injury). There was progression of injury on repeat CT scan in only two patients that required operation, and this accompanied clinical deterioration. The mean brain Abbreviated Injury Scale (AIS) score was 4.8±0.3 for surgical patients on initial CT scan compared with 3.4±0.6 (P<0.001) for non-surgical patients. Initial CT subdural hematoma size was 1.1±0.6 cm for surgical patients compared with 0.49±0.3 cm (P=0.05) for non-surgical patients. There was no significant difference between intervention groups in terms of other intracranial injuries, demographics, vital signs, or change in GCS. Overall, 75 patients that did not require surgical intervention received RHCT. At $340 per CT,$51 000 was spent on unnecessary imaging ($367 000/year, extrapolated). Discussion:In an environment of increased scrutiny on healthcare expenditures, it is necessary to question dogma and eliminate unnecessary cost. Our data questions the use of routine repeat head CT scans in every patient with anatomic TBI and suggests that clinically stable patients with small injury can simply be followed clinically. Level of evidence:Level III

Ucraina: esiste uno spazio economico, esiste un popolo?

L’analisi economica non ha mai avuto molto interesse per lo studio delle variabili culturali delle popolazioni. Nella tradizione degli studi economici l’elemento umano entra solo in quanto fattore di produzione. La sua scarsità o abbondanza, la sua propensione all’innovazione, la sua capacità di adattamento ai cambiamenti del panorama produttivo, sono gli elementi che interessano tipicamente l’economista e guidano la sua analisi. La geopolitica invece, attenta a ragionare su molteplici piani (geografico, economico, storico, politico, culturale) e alle diverse scale geografiche (locale, regionale, nazionale, sovranazionale, globale) valutando le loro molteplici interferenze reciproche, è disciplina idonea a compiere analisi di largo respiro in grado di coniugare tutte queste multiformi dimensioni. Questo capitolo analizza le relazioni tra determinanti economiche e culturali con riferimento a un caso di studio che sembra, al riguardo, particolarmente paradigmatico: l’Ucraina, un paese che vive oggi una pericolosissima frattura interna che sembra confermare la natura intrinsecamente duale del paese, soggetto a spinte centrifughe molto potenti

A methodology for determining the relationship between air transportation demand and the level of service

January 1976Includes bibliographical referencesIntroduction: Within the last ten years significant advances in the state-of-the art in air travel demand analysis stimulated researchers in the domestic air transportation field. Among these advances, researchers in academia, industry, and government have investigated the relationship between observed demand and general level of economic activity such as GNP on the one hand and general passenger-perceived characteristics such as fare on the other hand. Advanced econometric techniques have been used to develop these relationships. However, to date very little effort has been devoted to investigating the impact of a change in the supply of air transportation service on the demand for air transportation. Thus, for all practical purposes, there are no analytical economic models which show the complex interrelationship between the supply of and the demand for air transportation. This research report is an attempt to begin to understand these complex interrelationships. During the sixties the demand for air transportation services experienced substantial growth rates due to the fact that fares (in constant dollars) were continually declining (because of increasing productivity of transport aircraft) and partly due to the fact that the level of service offered was continuously increasing, again the result of improvements in technology. However, at the beginning of the current decade the growth in the demand for air transportation services began to exhibit radical and unforeseen changes. These changes were caused by a reversal of the impact of the two factors mentioned earlier, namely that the fares were now increasing (due to rapidly increasing costs, particularly with respect to the price of fuel) and the level of service was decreasing, particularly evidenced by fewer total flights and fewer direct flights. The demand models developed in the sixties were adequate to caution airline managers on the impact of changes in the general state of the economy and changes in fare level. However, since these models did not adequately incorporate the factors relating to the supply of air transportation services, very few analysts were able to predict the impact of a change in the level of service. As a result, the industry was quite surprised to observe suppressed traffic growth rates when the level of service offered was changed as a result of a general recession in the economy and shortage of fuel. Due to the deterioration in the financial position, the carriers began to cut costs by reducing further the level of service offered. However, instead of improving the profitability of the carriers, this strategy further suppressed traffic and hence revenue, resulting in even lower profits. On the basis of evidence from the above discussion, there is now a critical need for the development of economic models that simultaneously incorporate the factors effecting both the demand and the supply of air transportation services. In order to begin to fulfill this need, the Aeronautical Systems Office of Ames Research Center at NASA funded a research project to investigate how the supply related variables (particularly those related directly to technology) contribute to the determination of the demand for air transportation. The research was divided into two parts. The first part, mostly exploratory in nature, was designed to determine whether sophisticated economic models incorporating supply and demand factors can be developed given the state-of-the-art in econometric modeling and the limitations of the existing data. During this phase the thrust of the research effort was first to analyze the existing data, second to analyze the components of the levels of service and third to develop simple models which serve merely to generate avenues of pursuit for further research in the second phase. This report presents the results of the initial exploratory phase of the research project and contains directions for research in the second phase to be carried out in 1976. During the first phase, research efforts were directed at investigating single equation models incorporating a level of service index in addition to the usual fare and socioeconomic terms. The models were calibrated using data from fifty-eight region pairs over a sixteen year period. The level of service index developed in this report represents an improvement over the one incorporated in past models (namely flight frequency). The new level of service index is a nondimensional generalized trip time scaled from zero to one, which takes into account not only the number of flights, but also number of intermediate stops, direct or connecting service, speed of aircraft and most important, the matching of the departure schedules to time variability of demand. Based upon the preliminary results, it appears that the level of service is a more appropriate explanatory variable in the demand model than just frequency. The significant results of the demand models developed in this exploratory stage of the research will be discussed in the following sections of this report. Section 2 describes the reasons for calibrating the models based upon region pair data rather than city pair data. Section 3 differentiates between the supply and demand components of air travel and elaborates upon the development of the level of service index. Section 4 discusses the sampling procedures used in determining the region pairs. Section 5 contains the specification of the single equation models and presents the empirical results. The final section of this report outlines the plans for future research in Phase II of this project.Prepared under Contract by the Flight Transportation Laboratory, Dept. of Aeronautics and Astronautics, Massachusetts Institute of Technology for Ames Research Center, National Aeronautics and Space Administratio

Mass casualty events: what to do as the dust settles?

Care during mass casualty events (MCE) has improved during the last 15 years. Military and civilian collaboration has led to partnerships which augment the response to MCE. Much has been written about strategies to deliver care during an MCE, but there is little about how to transition back to normal operations after an event. A panel discussion entitled The Day(s) After: Lessons Learned from Trauma Team Management in the Aftermath of an Unexpected Mass Casualty Event at the 76th Annual American Association for the Surgery of Trauma meeting on September 13, 2017 brought together a cadre of military and civilian surgeons with experience in MCEs. The events described were the First Battle of Mogadishu (1993), the Second Battle of Fallujah (2004), the Bagram Detention Center Rocket Attack (2014), the Boston Marathon Bombing (2013), the Asiana Flight 214 Plane Crash (2013), the Baltimore Riots (2015), and the Orlando Pulse Night Club Shooting (2016). This article focuses on the lessons learned from military and civilian surgeons in the days after MCEs

Treatment of human brucellosis with rifampin plus minocycline

In order to evaluate the efficacy and tolerability of a high intravenous dose of rifampin plus oral minocycline (administered daily for 3 weeks) for the treatment of acute brucellosis, we retrospectively reviewed the outcome of 239 consecutive patients (135 adults and 104 children) diagnosed and treated over a 17-year period in Italy. The combination used resulted in 100% response and a relapse rate lower than 2%. Fifty-two (30 adults and 22 children) (29.8%) complained of mild adverse effects including an increase in aspartate aminotransferase (>250 IU) observed in 12 cases and considered related to rifampin and in 11 cases a reversible hyperpigmentation of the tongue attributed to minocycline. A randomized prospective comparative study should be performed to confirm our encouraging result