Research related to variable sweep aircraft development

Development in high speed, variable sweep aircraft research is reviewed. The 1946 Langley wind tunnel studies related to variable oblique and variable sweep wings and results from the X-5 and the XF1OF variable sweep aircraft are discussed. A joint program with the British, evaluation of the British "Swallow", development of the outboard pivot wing/aft tail configuration concept by Langley, and the applied research program that followed and which provided the technology for the current, variable sweep military aircraft is outlined. The relative state of variable sweep as a design option is also covered

Life history of the swamp rabbit (Sylvilagus Aquaticus) in Missouri

"This study was designed to provide information about various phases of the life history of the swamp rabbit, with special emphasis on home ranges and the reproductive cycle. Field work was begun in June, 1956, and ended in July, 1957."--Page

Preliminary evidence for the influence of physiography and scale upon the autocorrelation function of remotely sensed data

Previously established results demonstrate that LANDSAT data are autocorrelated and can be described by a univariate linear stochastic process known as auto-regressive-integrated-moving-average model of degree 1, 0, 1 or ARIMA (1, 0, 1). This model has two coefficients of interest for interpretation phi(1) and theta(1). In a comparison of LANDSAT thematic mapper simulator (TMS) data and LANDSAT MSS data several results were established: (1) The form of the relatedness as described by this model is not dependent upon system look angle or pixel size. (2) The phi(1) coefficient increases with decreasing pixel size and increasing topographic complexity. (3) Changes in topography have a greater influence upon phi(1) than changes in land cover class. (4) The theta(1) seems to vary with the amount of atmospheric haze. These patterns of variation in phi(1) and theta(1) are potentially exploitable by the remote sensing community to yield stochastically independent sets of observations, characterize topography, and reduce the number of bytes needed to store remotely sensed data

Nyckeltal och företags prestation

The study tests if there is a significant relationship between a company´s key ratios in a year prior to a recession and its performance during it. After selecting and calculating company data the causality is tested through classical linear regression models. The results show that there is a significant relationship between key ratios and performance

Advances in tensiometer-based suction control systems.

Cunningham (2000) and Jotisankasa (2005) pioneered the development of tensiometer-based suction control systems. In these systems, wetting and drying of the soil are achieved by water injection and circulation of air in contact with the specimen while suction is monitored by sample-mounted high suction tensiometers. Unlike the axis translation technique, these systems avoid using elevated air pressures and better reproduce the drying and wetting conditions occurring in the field. Building upon these earlier works, this pa-per describes an automated tensiometer-based suction control system that enables direct measurement of water content changes inside the sample. A diaphragm pump forces air to flow inside a closed loop that runs across the sample while a moisture trap ensures that the relative humidity of the circulating air is kept low. As the circulating air dries the soil, the amount of abstracted water is measured by continuous weighing of the desiccant inside the moisture trap. Wetting of the sample is instead achieved by controlled injection of water through a solenoid valve connected to a pressurized volume gauge. The changes of soil water content are given by the difference between the amounts of water injected by the volume gauge and that retained by the desiccant. The system is used to impose cycles of drying and wetting on compacted clayey specimens and results from preliminary tests are presented

Prognostic significance of high-grade dysplasia in colorectal adenomas.

Aim  Colonoscopy to detect and remove polyps has contributed to a reduction in colorectal carcinoma. Three-year follow up is recommended for patients considered to be at high risk (at least three adenomas, adenoma ≥ 1 cm, villous or high-grade features). Our study focused on patients diagnosed with high-grade dysplasia with regard to initial management and follow up. Method  A search of patients who had had endoscopic removal of a high-grade adenoma was carried out. Patients with the following were excluded: follow up of \u3c 1 year, polyposis syndromes, prior colon cancer and a diagnosis of adenocarcinoma within 6 months following initial diagnosis. Results  Eighty-three patients treated between 1999 and 2007 for high-grade dysplasia (HGD) in a colorectal adenoma were identified. Over a median follow-up period of 4 years, 53 (64%) developed further adenomatous polyps. Among these, 7% had an adenoma with HGD or an adenocarcinoma. In all these patients, the initial high-grade adenoma was \u3e 1 cm in diameter. Initial follow-up colonoscopy was performed on average 7 months following the initial diagnosis. Ten per cent of patients underwent prophylactic segmental resection, and 6% received argon laser therapy. Conclusion  The study demonstrates that patients who have a colorectal adenoma \u3e 1 cm with HGD may be at high risk of developing further adenomas with HGD or carcinoma. Close follow up is warranted

Large orders in strong-field QED

We address the issue of large-order expansions in strong-field QED. Our approach is based on the one-loop effective action encoded in the associated photon polarisation tensor. We concentrate on the simple case of crossed fields aiming at possible applications of high-power lasers to measure vacuum birefringence. A simple next-to-leading order derivative expansion reveals that the indices of refraction increase with frequency. This signals normal dispersion in the small-frequency regime where the derivative expansion makes sense. To gain information beyond that regime we determine the factorial growth of the derivative expansion coefficients evaluating the first 80 orders by means of computer algebra. From this we can infer a nonperturbative imaginary part for the indices of refraction indicating absorption (pair production) as soon as energy and intensity become (super)critical. These results compare favourably with an analytic evaluation of the polarisation tensor asymptotics. Kramers-Kronig relations finally allow for a nonperturbative definition of the real parts as well and show that absorption goes hand in hand with anomalous dispersion for sufficiently large frequencies and fields.Comment: 26 pages, 6 figure

Implementation of a neonatal hearing screening programme in three provinces in Albania

Objectives: The EUSCREEN study compares the cost-effectiveness of paediatric hearing screening programmes and aims to develop a cost-effectiveness model for this purpose. Alongside and informed by the development of the model, neonatal hearing screening (NHS) is implemented in Albania. We report on the first year. Methods: An implementation plan was made addressing objectives, target population, screening protocol, screener training, screening devices, care pathways and follow up. NHS started January 1st, 2018 in four maternity hospitals: two in Tirana, one in Pogradec and one in Kukës, representing both urban and rural areas. OAE-OAE-aABR was used to screen well infants in maternity hospitals, whereas aABR-aABR was used in neonatal intensive care units and in mountainous Kukës for all infants. Screeners’ uptake and attitudes towards screening and quality of screening were assessed by distributing questionnaires and visiting the maternity hospitals. The result of screening, diagnostics, follow up and entry into early intervention were registered in a database and monitored. Results: Screeners were keen to improve their skills in screening and considered NHS valuable for Albanian health care. The number of “fail” outcomes after the first screen was high initially but decreased to less than 10% after eight months. In 2018, 11,507 infants were born in the four participating maternity hospitals, 10,925 (94.9%) of whom were screened in the first step. For 486 infants the result of screening was not registered. For the first screen, ten parents declined, eight infants died and one infant was discharged before screening could be performed. In 1115 (10.2%) infants the test either could not be performed or the threshold was not reached; 361 (32,4%) of these did not attend the second screen. For the third screen 31 (34.4%) out of 90 did not attend. Reasons given were: parents declined (124), lived too far from screening location (95), their infant died (11), had other health issues (7), or was screened in private clinic (17), no reason given (138). Conclusions: Implementation of NHS in Albania is feasible despite continuing challenges. Acceptance was high for the first screen. However, 32.4% of 1115 infants did not attend the second screen, after a “fail” outcome for the first test