327 research outputs found
Critical international relations and the impact agenda
How should critical International Relations (IR) scholars approach the ‘impact agenda’? While most have been quite resistant to it, I argue in this essay that critical IR should instead embrace the challenge of impact – and that both IR as a field and the impact agenda more broadly would gain greatly from it doing so. I make this case through three steps. I show, firstly, that critical IR has till now been very much at the impact agenda’s margins, and that this situation contrasts strikingly with its well-established importance within IR teaching and research. I argue, secondly, that critical IR scholars both could and should do more impact work – that the current political conjuncture demands it, that many of the standard objections to doing so are misplaced, and indeed that ‘critical’ modes of research are in some regards better suited than ‘problem-solving’ ones to generating meaningful change – and offer a series of recommended principles for undertaking critically-oriented impact and engagement work. But I also argue, thirdly, that critical social science holds important lessons for the impact agenda, and that future impact assessments need to take these lessons on board – especially if critical IR scholarship is to embrace impact more fully. Critical IR, I submit, should embrace impact; but at the same time, research councils and assessments could do with modifying their approach to it, including by embracing a more critical and political understanding of what impact is and how it is achieved
Modelling the Thermal Energy Storage of Cementitious Mortars Made with PCM-Recycled Brick Aggregates
This paper reports a numerical approach for modelling the thermal behavior and heat accumulation/liberation of sustainable cementitious composites made with Recycled Brick Aggregates (RBAs) employed as carriers for Phase-Change Materials (PCMs). In the framework of the further development of the fixed grid modelling method, classically employed for solving the well-known Stefan problem, an enthalpy-based approach and an apparent calorific capacity method have been proposed and validated. More specifically, the results of an experimental program, following an advanced incorporation and immobilization technique, developed at the Institut für Werkstoffe im Bauwesen for investigating the thermal responses of various combinations of PCM-RBAs, have been considered as the benchmark to calibrate/validate the numerical results. Promising numerical results have been obtained, and temperature simulations showed good agreement with the experimental data of the analyzed mixtures
Inter- and intraobserver reliability of morphological Mutch classification for greater tuberosity fractures of the proximal humerus: A comparison of x-ray, two-, and three-dimensional CT imaging
Background The objective of this study was to investigate inter- and intraobserver reliability of the morphological Mutch classification for greater tuberosity (GT) fragments in consecutive proximal humerus fractures (PHF) regardless of the number of parts according to the Codman classification system for three different imaging modalities (plain radiographs, two-dimensional [2-D] computed tomography [CT], and reformatted, three-dimensional [3-D] CT reconstruction). Materials and methods One hundred thirty-eight consecutive PHF with GT involvement were identified between January 2018 and December 2018 in a supraregional Level 1 trauma center. GT morphology was classified by three blinded observers according to the morphological Mutch classification using the picture archiving and communication software Visage 7.1 (Visage Imaging Inc., San Diego, CA, USA). Fleiss’ and Cohens’ kappa were assessed for inter- and intraobserver reliability. Strength of agreement for kappa (k) values was interpreted according to the Landis and Koch benchmark scale. Results In cases of isolated GT fractures (n = 24), the morphological Mutch classification achieved consistently substantial values for interobserver reliability (radiograph: k = 0.63; 2-D CT: k = 0.75; 3-D CT: k = 0.77). Moreover, use of advanced imaging (2-D and 3-D CT) tends to increase reliability. Consistently substantial mean values were found for intraobserver agreement (radiograph: Ø k = 0.72; 2-D CT: Ø k = 0.8; 3-D CT: Ø k = 0.76). In cases of multi-part PHF with GT involvement (n = 114), interobserver agreement was only slight to fair regardless of imaging modality (radiograph: k = 0.3; 2-D CT: k = 0.17; 3-D CT: k = 0.05). Intraobserver agreement achieved fair to moderate mean values (radiograph: Ø k = 0.56; 2-D CT: Ø k = 0.61; 3-D CT: Ø k = 0.33). Conclusion The morphological Mutch classification remains a reliable classification for isolated GT fractures, even with 2-D or 3-D CT imaging. Usage of these advanced imaging modalities tends to increase interobserver reliability. However, its reliability for multi-part fractures with GT involvement is limited. A simple and reliable classification is missing for this fracture entity
Design of Low-Loss Coaxial Cavity Bandpass Filter with Post-Manufacturing Tuning Capabilities
This paper presents a low-loss of coaxial cavity bandpass filter with post-manufacturing tuning capabilities.A systematic filter development using the lowpass prototype as a starting point to produce 4th degreeChebyshevbandpass response is demonstrated. The coaxial cavity filter based upon TEM mode of propagation has the center frequency of 2.5 GHz and bandwidth of 168MHz. The insertion loss of 0.15 dB insertion loss and return loss better than 15 dB areobtained particularly in the passband. This type of microwave filter would be useful in any microwave systems where the low insertion loss and high selectivity are crucial, such as in a base station, radar and satellite transceivers
Rectangular Microstrip Patch Antenna Based on Resonant Circuit Approach
This paper presents the investigation based upon the resonant circuit approach to characterize the rectangular
microstrip patch antenna from the low-pass prototype lumped
element. The physical layout of the rectangular microstrip patch antenna based on single-mode and dual-mode will be established. An improvement on bandwidth of the antenna can be achieved by increasing the number of modes. In the paper, the understanding of microwave filter synthesis technique is applied in order to obtain the resonance at 2 GHz. A notch technique is used in the design to produce dual-mode frequencies on the microstrip patch antenna. The prototype circuit and proposed physical layout of the single and dual-mode microstrip patch antennas are demonstrated through the analysis of circuit and EM simulations in order to proof the proposed concept. This
study would be useful to realize antenna for broadband applications as well as to investigate the appropriate technique
for integrating antenna and microwave filter
Multiple microvessels extending from the coronary arteries to the left ventricle in a middle aged female presenting with ischaemic chest pain: a case report
Possible ischaemic chest pain presentations are exceedingly common. Angiographic triage of clinical, electrocardiographic or biomarker positive presentations is increasingly feasible with the expansion of cardiac catheterization facilities. This management pattern often extends to problem patients with negative biomarker screens whose symptoms appear unstable. With invasive triage even very rare congenital or developmental coronary anomalies will be more frequently recognized although their relationship to ischaemia can be confounded by association. In this a case we report a woman with widespread direct coro-ventricular micro-channel formation across the heart and an ischaemic presentation, despite angiographically normal epicoronary vessels. This pattern, while very rare, needs to be recognized as one possible phenotype in this very common clinical presentation
Surgical site infection after gastrointestinal surgery in high-income, middle-income, and low-income countries: a prospective, international, multicentre cohort study
Background: Surgical site infection (SSI) is one of the most common infections associated with health care, but its importance as a global health priority is not fully understood. We quantified the burden of SSI after gastrointestinal surgery in countries in all parts of the world.
Methods: This international, prospective, multicentre cohort study included consecutive patients undergoing elective or emergency gastrointestinal resection within 2-week time periods at any health-care facility in any country. Countries with participating centres were stratified into high-income, middle-income, and low-income groups according to the UN's Human Development Index (HDI). Data variables from the GlobalSurg 1 study and other studies that have been found to affect the likelihood of SSI were entered into risk adjustment models. The primary outcome measure was the 30-day SSI incidence (defined by US Centers for Disease Control and Prevention criteria for superficial and deep incisional SSI). Relationships with explanatory variables were examined using Bayesian multilevel logistic regression models. This trial is registered with ClinicalTrials.gov, number NCT02662231.
Findings: Between Jan 4, 2016, and July 31, 2016, 13 265 records were submitted for analysis. 12 539 patients from 343 hospitals in 66 countries were included. 7339 (58·5%) patient were from high-HDI countries (193 hospitals in 30 countries), 3918 (31·2%) patients were from middle-HDI countries (82 hospitals in 18 countries), and 1282 (10·2%) patients were from low-HDI countries (68 hospitals in 18 countries). In total, 1538 (12·3%) patients had SSI within 30 days of surgery. The incidence of SSI varied between countries with high (691 [9·4%] of 7339 patients), middle (549 [14·0%] of 3918 patients), and low (298 [23·2%] of 1282) HDI (p < 0·001). The highest SSI incidence in each HDI group was after dirty surgery (102 [17·8%] of 574 patients in high-HDI countries; 74 [31·4%] of 236 patients in middle-HDI countries; 72 [39·8%] of 181 patients in low-HDI countries). Following risk factor adjustment, patients in low-HDI countries were at greatest risk of SSI (adjusted odds ratio 1·60, 95% credible interval 1·05–2·37; p=0·030). 132 (21·6%) of 610 patients with an SSI and a microbiology culture result had an infection that was resistant to the prophylactic antibiotic used. Resistant infections were detected in 49 (16·6%) of 295 patients in high-HDI countries, in 37 (19·8%) of 187 patients in middle-HDI countries, and in 46 (35·9%) of 128 patients in low-HDI countries (p < 0·001).
Interpretation: Countries with a low HDI carry a disproportionately greater burden of SSI than countries with a middle or high HDI and might have higher rates of antibiotic resistance. In view of WHO recommendations on SSI prevention that highlight the absence of high-quality interventional research, urgent, pragmatic, randomised trials based in LMICs are needed to assess measures aiming to reduce this preventable complication
Modelling the Thermal Energy Storage of Cementitious Mortars Made with PCM-Recycled Brick Aggregates
This paper reports a numerical approach for modelling the thermal behavior and heat accumulation/liberation of sustainable cementitious composites made with Recycled Brick Aggregates (RBAs) employed as carriers for Phase-Change Materials (PCMs). In the framework of the further development of the fixed grid modelling method, classically employed for solving the well-known Stefan problem, an enthalpy-based approach and an apparent calorific capacity method have been proposed and validated. More specifically, the results of an experimental program, following an advanced incorporation and immobilization technique, developed at the Institut für Werkstoffe im Bauwesen for investigating the thermal responses of various combinations of PCM-RBAs, have been considered as the benchmark to calibrate/validate the numerical results. Promising numerical results have been obtained, and temperature simulations showed good agreement with the experimental data of the analyzed mixtures
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