33,749 research outputs found
The effect of cyclic feathering motions on dynamic rotor loads
The dynamic loads of a helicopter rotor in forward flight are influenced significantly by the geometric pitch angles between the structural axes of the hub and blade sections and the plane of rotation. The analytical study presented includes elastic coupling between inplane and out-of-plane deflections as a function of geometric pitch between the plane of rotation and the principal axes of inertia of each blade. The numerical evaluation is based on a transient analysis using lumped masses and elastic substructure techniques. A comparison of cases with and without cyclic feathering motion shows the effect on computed dynamic rotor loads
New results of intersection numbers on moduli spaces of curves
We present a series of new results we obtained recently about the
intersection numbers of tautological classes on moduli spaces of curves,
including a simple formula of the n-point functions for Witten's
classes, an effective recursion formula to compute higher Weil-Petersson
volumes, several new recursion formulae of intersection numbers and our proof
of a conjecture of Itzykson and Zuber concerning denominators of intersection
numbers. We also present Virasoro and KdV properties of generating functions of
general mixed and intersections.Comment: 9 pages, a brief surve
Жизнь в Риме. Древний Рим в зеркале латинских инскрипций
В настоящей монографии представлена жизнь всех слоев римского общества на основе данных латинских инскрипций. Рассматриваются следующие темы: аристократия, религия, военное дело, римская семья и домашнее хозяйство, жизнь римского обывателя.Публикуемые латинские инскрипции снабжены параллельными переводами на английский язык и краткими историко-филологическими комментариями. Прилагается избранная библиография для дальнейшего чтения, составленная по тематическому принципу (с. 185-188)
What factors influence the optometric referral reply rate? A mixed methods study
Purpose: Community optometrists are primary eye care providers. Through the routine sight test, optometrists can engage in opportunistic case finding, identifying patients who present with disease or ocular abnormalities that require referral for secondary medical care. Optometrists refer patients but in many cases no referral outcome letter/reply is received. In the absence of a reply, patients often need to be re-referred unnecessarily, potentially increasing the number of other patients who lose sight whilst waiting on extensive hospital waiting lists. Sight loss could be irreversible. To increase/optimise the number of referral reply letters from secondary care it is necessary to understand what factors influence the optometric referral reply rate.
Methods: Ethics approval was obtained for a multiphase sequential mixed methods primary research study (qual - QUAN - qual). Documentary analysis of 349 patient referral records from three optometric practice modalities (domiciliary practice, an independently owned group and an optical corporate chain) were quantitatively investigated using IBM SPSS Statistics 25 software. One-on-one, semi-structured interviews were used to obtain the views of thirteen stakeholders These were qualitatively analysed using NVivo 12 software.
Results: A referral reply rate of 11.2% was calculated. Factors influencing the optometric referral reply rate included; technology, the GP, optometrists’ utility to and utility of the NHS, patient mobilisation and individual behavioural differences.
Conclusion: Community optometrists can and should improve the referral reply rate by responding to the factors identified
Explosive Events and the Evolution of the Photospheric Magnetic Field
Transition region explosive events have long been suggested as direct
signatures of magnetic reconnection in the solar atmosphere. In seeking further
observational evidence to support this interpretation, we study the relation
between explosive events and the evolution of the solar magnetic field as seen
in line-of-sight photospheric magnetograms. We find that about 38% of events
show changes of the magnetic structure in the photosphere at the location of an
explosive event over a time period of 1 h. We also discuss potential
ambiguities in the analysis of high sensitivity magnetograms
Structural Tailoring of Advanced Turboprops (STAT) programmer's manual
The Structural Tailoring of Advanced Turboprops (STAT) computer program was developed to perform numerical optimizations on highly swept propfan blades. This manual describes the functionality of the STAT system from a programmer's viewpoint. It provides a top-down description of module intent and interaction. The purpose of this manual is to familiarize the programmer with the STAT system should he/she wish to enhance or verify the program's function
NASA information resources for the feedback process
NASA information resources for feedback proces
Non-Commutative Instantons and the Seiberg-Witten Map
We present several results concerning non-commutative instantons and the
Seiberg-Witten map. Using a simple ansatz we find a large new class of
instanton solutions in arbitrary even dimensional non-commutative Yang-Mills
theory. These include the two dimensional ``shift operator'' solutions and the
four dimensional Nekrasov-Schwarz instantons as special cases. We also study
how the Seiberg-Witten map acts on these instanton solutions. The infinitesimal
Seiberg-Witten map is shown to take a very simple form in operator language,
and this result is used to give a commutative description of non-commutative
instantons. The instanton is found to be singular in commutative variables.Comment: 26 pages, AMS-LaTeX. v2: the formula for the commutative description
of the Nekrasov-Schwarz instanton corrected (sec. 4). v3: minor correction
Perceived Economic Pressures and Farmer Ethics
We consider the effect of perceived economic pressures on the ethical attitudes of farmers. We hypothesize that an increase in the economic pressures a farmer faces could result in that farmer being more tolerant of unethical conduct than farmers not experiencing economic pressures. To test this hypothesis, we use data from a survey of 3,000 Missouri farmers with farm sales in excess of $10,000 in 2005 in which farmers were asked how acceptable they considered various unethical or questionable farming practices. The survey also contained questions designed to measure perceived economic pressures. We find evidence that economic pressures result in a greater willingness of farmers to tolerate unethical conduct, particularly in the case of actions that have the potential of causing harm or that are influenced by law or contract. We also find that the more frequently a farmer reports observing an unethical action, the more acceptable he is of it.Farm Management,
- …