38 research outputs found
"For We Who Were Occidentals Have Become Orientals:" The Evolution of Intermediaries in the Latin East, 1095-1291
The majority of research on the Crusades presents a dichotomy between Arab-Turkic Muslims and Latin Christians, Muslim potentates and the "Crusader States," frequently depicted as French colonies in all but name. The corpus of political and military history bypasses the subject of practical communication and interaction between groups, not only the Arab-Muslima and Latin Christian, but also the local Armenian, Greek, and Syrian Christian communities. By examining the representations and roles of interpreters, envoys, and negotiators in a spectrum of primary sources, it is possible to discern the evolution of the greater role of the Franks in the Levant. My sources include Fulcher of Chartresâ and William of Tyre's Latin chronicles, as well as Anna Comnena's Greek, ibn al-Athir's and BahÄ' al-DÄ«n's Arabic, Bar Hebraeusâ Syriac, and Matthew of Edessa's Armenian. For non-historical works, I have turned to the Old French Chanson d'Antioche narrative, Ibn Jubayr's and Benjamin of Tudela's travelogues, and UsÄmah ibn Munqidhâs memoirs. Legal charters and records, as well as the rules of the military orders provide factual evidence to balance these written opinions. From the interactions depicted in these sources, it becomes clear that the "Crusader States" may be more accurately conceptualized as the "Latin East," in which the generations after the First Crusade grew up thinking and acting not simply as Latins, but Latin Easterners, living in a complex, multi-lingual and multi-religious region. While the evidence to determine their level of acculturation is lacking, it is possible to see these Eastern Franks change their methods of making war and peace, particularly with regards to the background and methods of interpreters and envoys. I argue that the descendants of the early Crusaders came to think of themselves as long-term members of a Levantine community, demonstrated by their patterns of interactions with other members.No embarg
Tip cap for a rotor blade
A replaceable tip cap for attachment to the end of a rotor blade is described. The tip cap includes a plurality of walls defining a compartment which, if desired, can be divided into a plurality of subcompartments. The tip cap can include inlet and outlet holes in walls thereof to permit fluid communication of a cooling fluid there through. Abrasive material can be attached with the radially outer wall of the tip cap
Kirigami-Inspired Organic and Inorganic Film-Based Flexible Thermoelectric Devices with Built-In Heat Sink
Thermoelectric (TE) devices can convert heat to electricity directly, which offers a unique opportunity to realize waste heat recovery. However, conventional TE devices inevitably use heat sinks, which are bulky, rigid and heavy, limiting practical applications. Herein, we propose a fully integrated film-based TE device with intrinsically built-in fins as heat sink in a hexagonal honeycomb device structure, that simultaneously achieves high TE performance and conformability, as confirmed by experiments and modelling. A flexible Kapton substrate with copper electrodes, integrating either carbon nanotube (CNT) veils or bismuth telluride (Bi2Te3) TE âlegsâ, both of n- and p-type, achieved a remarkable specific power of 185.4 nW Kâ2 for a Bi2Te3-based device and 53.1 nW Kâ2 for a CNT-based device, thanks to the heat dissipation effect granted by the built-in fins. Besides, the addition of oriented polymer films interconnects, contracting when above their glass transition temperature, allowed a single substrate two-dimensional (2D) TE device to self-fold into a three-dimensional (3D) hexagonal honeycomb structure, with built-in fins, contactlessly and autonomously. The demonstrated shape-programmed kirigami-inspired scalable TE device paves the way for realising self-powered applications comprising hundreds of TE legs with both inorganic (e.g., Bi2Te3) and organic (e.g. CNT veils) TE materials and integrated heat sinks
Design and characterization of hybrid IIIâV concentrator photovoltaicâthermoelectric receivers under primary and secondary optical elements
Lattice-matched monolithic triple-junction Concentrator Photovoltaic (CPV) cells (InGa(0.495)P/GaIn(0.012)As/Ge) were electrically and thermally interfaced to two Thermoelectric (TE) Peltier module designs. An electrical and thermal model of the hybrid receivers was modelled in COMSOL Multiphysics software v5.3 to improve CPV cell cooling whilst increasing photon energy conversion efficiency. The receivers were measured for current-voltage characteristics with the CPV cell only (with sylguard encapsulant), under single secondary optical element (SOE) at x2.5 optical concentration, and under Fresnel lens primary optical element (POE) concentration between x313 and x480. Measurements were taken in solar simulators at Cardiff and Jaén Universities, and on-sun with dual-axis tracking at Jaén University. The hybrid receivers were electrically, thermally and theoretically investigated. The electrical performance data for the cells under variable irradiance and cell temperature conditions were measured using the integrated thermoelectric module as both a temperature sensor and as a solid-state heat pump. The performance of six SOE-CPV-TE hybrid devices were evaluated within two 3-receiver strings under primary optical concentration with measured acceptance angles of 1.00o and 0.89o, similar to commercially sourced CPV modules. A six-parameter one-diode equivalent electrical model was developed for the multi-junction CPV cells with SOE and POE. This was applied to extract six model parameters with the experimental I-V curves of type A receiver at 1, 3 and 500 concentration ratios. Standard test conditions (1000W/m2, 25oC and AM1.5G spectrum) were assumed based on trust-region-reflective least squares algorithm in MATLAB. The model fitted the experimental I-V curves satisfactorily with a mean error of 4.44%, and the optical intensity gain coefficient of SOE and POE is as high as 0.91, in comparison with 0.50-0.86 for crossed compound parabolic concentrators (CCPC). The determined values of diode reverse saturation current, combined series resistance and shunt resistance were similar to those of monocrystalline PV cell/modules in our previous publications. The model may be applicable to performance prediction of multi-junction CPV cells in the future
A causal relationship between right paraduodenal hernia and superior mesenteric artery syndrome: a case report
<p>Abstract</p> <p>Introduction</p> <p>Cases of right paraduodenal hernia and superior mesenteric artery syndrome have been reported separately, but their occurrence in combination has not been reported.</p> <p>Case presentation</p> <p>A 46-year-old Japanese man who had never undergone laparotomy was admitted to our hospital due to an acute abdomen. An enhanced multidetector-row computed tomography scan of our patient showed a cluster of small intestines with ischemic change in his right lateral abdominal cavity. Emergency surgery was subsequently performed, and strangulation of the distal jejunum along with incidental right paraduodenal hernia was found. His necrotic ileum was resected, and the jejunum encapsulated by the sac was repaired manually without reduction.</p> <p>Three days after the operation, however, our patient developed vomiting. An upper gastrointestinal series revealed a straight line cut-off sign on the third portion of his duodenum. A second enhanced multidetector-row computed tomography scan showed that he had a lower aortomesenteric angle and a shorter aortomesenteric distance compared to his condition before his right paraduodenal hernia was surgically repaired. We strongly suspected that the right paraduodenal hernia repair may have induced superior mesenteric artery syndrome. On the 21st post-operative day, duodenojejunostomy was performed because conservative management had failed.</p> <p>Conclusions</p> <p>In this case, enhanced multidetector-row computed tomography, which permits reconstructed multiplanar imaging, helped us to visually identify these diseases easily. It is important to recognize that surgical repair of a right paraduodenal hernia may cause superior mesenteric artery syndrome.</p
Adults' past-day recall of sedentary time: reliability, validity and responsiveness
Purpose: Past-day recall rather than recall of past week or a usual/typical day may improve the validity of self-reported sedentary time measures. This study examined the test-retest reliability, criterion validity, and responsiveness of the seven-item questionnaire, Past-day Adults' Sedentary Time (PAST). Methods: Participants (breast cancer survivors, n = 90, age = 33-75 yr, body mass index = 25-40 kg.m(-2)) in a 6-month randomized controlled trial of a lifestyle-based weight loss intervention completed the interviewer-administered PAST questionnaire about time spent sitting/lying on the previous day for work, transport, television viewing, nonwork computer use, reading, hobbies, and other purposes (summed for total sedentary time). The instrument was administered at baseline, 7 d later for test-retest reliability (n = 86), and at follow-up. ActivPAL3-assessed sit/lie time in bouts of >= 5 min during waking hours on the recall day was used as the validity criterion measure at both baseline (n = 72) and follow-up (n = 68). Analyses included intraclass correlation coefficients, Pearson's correlations (r), and Bland-Altman plots and responsiveness index. Results: The PAST had fair to good test-retest reliability (intraclass correlation coefficient = 0.50, 95% confidence interval [CI] = 0.32-0.64). At baseline, the correlation between PAST and activPAL sit/lie time was r = 0.57 (95% CI = 0.39-0.71). The mean difference between PAST at baseline and retest was -25 min (5.2%), 95% limits of agreement = -5.9 to 5.0 h, and the activPAL sit/lie time was -9 min (1.8%), 95% limits of agreement = -4.9 to 4.6 h. The PAST showed small but significant responsiveness (-0.44, 95% CI = -0.92 to -0.04); responsiveness of activPAL sit/lie time was not significant. Conclusion: The PAST questionnaire provided an easy-to-administer measure of sedentary time in this sample. Validity and reliability findings compare favorably with other sedentary time questionnaires. Past-day recall of sedentary time shows promise for use in future health behavior, epidemiological, and population surveillance studies
Measuring older adults' sedentary time: Reliability, validity, and responsiveness
GARDINER, P. A., B. K. CLARK, G. N. HEALY, E. G. EAKIN, E. A. H. WINKLER, and N. OWEN. Measuring Older Adults' Sedentary Time: Reliability, Validity, and Responsiveness. Med. Sci. Sports Exerc., Vol. 43, No. 11, pp. 2127-2133, 2011. Purpose: With evidence that prolonged sitting has deleterious health consequences, decreasing sedentary time is a potentially important preventive health target. High-quality measures, particularly for use with older adults, who are the most sedentary population group, are needed to evaluate the effect of sedentary behavior interventions. We examined the reliability, validity, and responsiveness to change of a self-report sedentary behavior questionnaire that assessed time spent in behaviors common among older adults: watching television, computer use, reading, socializing, transport and hobbies, and a summary measure (total sedentary time). Methods: In the context of a sedentary behavior intervention, nonworking older adults (n = 48, age = 73 +/- 8 yr (mean +/- SD)) completed the questionnaire on three occasions during a 2-wk period (7 d between administrations) and wore an accelerometer (ActiGraph model GT1M) for two periods of 6 d. Test-retest reliability (for the individual items and the summary measure) and validity (self-reported total sedentary time compared with accelerometer-derived sedentary time) were assessed during the 1-wk preintervention period, using Spearman (rho) correlations and 95% confidence intervals (CI). Responsiveness to change after the intervention was assessed using the responsiveness statistic (RS). Results: Test-retest reliability was excellent for television viewing time (rho (95% CI) = 0.78 (0.63-0.89)), computer use (rho (95% CI) = 0.90 (0.83-0.94)), and reading (rho (95% CI) = 0.77 (0.62-0.86)); acceptable for hobbies (rho (95% CI) = 0.61 (0.39-0.76)); and poor for socializing and transport (rho < 0.45). Total sedentary time had acceptable test-retest reliability (rho (95% CI) = 0.52 (0.27-0.70)) and validity (rho (95% CI) = 0.30 (0.02-0.54)). Self-report total sedentary time was similarly responsive to change (RS = 0.47) as accelerometer-derived sedentary time (RS = 0.39). Conclusions: The summary measure of total sedentary time has good repeatability and modest validity and is sufficiently responsive to change suggesting that it is suitable for use in interventions with older adults