Flight flutter testing using pulse techniques

A case of flutter developed at a speed lower than had been flown previously. This incident precipitated the routine procedure of pulsing control surfaces as well as the firing of explosive charges during speed build-ups. In the interest of rapid evaluation of results, simple methods of data reduction were used. A case history is presented where in the pulse technique predicted flutter by extrapolating decay rates obtained at subcritical speeds; in addition, a case is presented where no valid extrapolation could be made

Study of phreatophyte growth in the Lower Arkansas River Valley of Colorado, A

CER63MWB-GES6.Includes bibliographical references (page 22).April 1963

Information for Operation of Water Supply Systems

Introduction: Water requirements increase as more people use more water for domestic purposes. The increase is augmented as technological advances add to the water needs of agriculture and industry. Additional urban landscaping adds further to the demand. Simultaneously, the same forces increase demands for flood control, hydrelectric power, and navigation; and a more urbanized population want more flows preserved for productive natural environments, recreational use, and aesthetic enjoyment. The response over the years to these growing demands on water resources has been to supply increasing amounts of water and greater levels of development for other purposes by building more projects, larger projects, multipurpose projects, and multiproject systems. The construction and operation of these facilities have changed the flow and water quality regimes of our rivers. Some majore river basins are now approaching full utilization of their runoff (U.S. Water Resources Council 1978). As the opportunities for water project construction are exhausted, the name of the game shifts to systems operation for more precise water delivery when and where it is needed. More rapid and reliable data collection can provide a better information base for determing need. Greater benefits can then be achieved by applying optimization models on a real time basis and promtly using the results in automated control systems. Fortunately, the needs for more carefully controlled water resources systems operation come at a time when advances in electronics are offering a new surveillance and control technologies. Greater efficiency can be achieved by more rapid measurement and thorough analysis for application of the informatino that has been used in the past as a basis for systems operation. However, full advantage of the capabilities of the electronic age can only be achieved by gathering information that has previously been impossible or impractical to obtain, developing more comprehensive analytic models, and applying the results with more precise automated control systems. The purpose of this paper is to stimulate thinking about what can be done. As a starting point, we will gather ideas by diagraming the natural cycle that supplies our water, identifying losses and inefficiencies within it that might be reduced through more effective use of information for operating purposes, and examining existing reservoir operation procedures. The resulting list of potential applications for information and control systems provide direction for refining current automated operating systems. We can end by dreaming about a fully automated system for irrigation water delivery

Experimental investigation of elastic mode control on a model of a transport aircraft

A 4.5 percent DC-10 derivative flexible model with active controls is fabricated, developed, and tested to investigate the ability to suppress flutter and reduce gust loads with active controlled surfaces. The model is analyzed and tested in both semispan and complete model configuration. Analytical methods are refined and control laws are developed and successfully tested on both versions of the model. A 15 to 25 percent increase in flutter speed due to the active system is demonstrated. The capability of an active control system to significantly reduce wing bending moments due to turbulence is demonstrated. Good correlation is obtained between test and analytical prediction

Classifying Organizations for Food System Ontologies using Natural Language Processing

Our research explores the use of natural language processing (NLP) methods to automatically classify entities for the purpose of knowledge graph population and integration with food system ontologies. We have created NLP models that can automatically classify organizations with respect to categories associated with environmental issues as well as Standard Industrial Classification (SIC) codes, which are used by the U.S. government to characterize business activities. As input, the NLP models are provided with text snippets retrieved by the Google search engine for each organization, which serves as a textual description of the organization that is used for learning. Our experimental results show that NLP models can achieve reasonably good performance for these two classification tasks, and they rely on a general framework that could be applied to many other classification problems as well. We believe that NLP models represent a promising approach for automatically harvesting information to populate knowledge graphs and aligning the information with existing ontologies through shared categories and concepts.Comment: Presented at IFOW 2023 Integrated Food Ontology Workshop at the Formal Ontology in Information Systems Conference (FOIS) 2023 in Sherbrooke, Quebec, Canada July 17-20th, 202

Exome sequencing of Finnish isolates enhances rare-variant association power.

Exome-sequencing studies have generally been underpowered to identify deleterious alleles with a large effect on complex traits as such alleles are mostly rare. Because the population of northern and eastern Finland has expanded considerably and in isolation following a series of bottlenecks, individuals of these populations have numerous deleterious alleles at a relatively high frequency. Here, using exome sequencing of nearly 20,000 individuals from these regions, we investigate the role of rare coding variants in clinically relevant quantitative cardiometabolic traits. Exome-wide association studies for 64 quantitative traits identified 26 newly associated deleterious alleles. Of these 26 alleles, 19 are either unique to or more than 20 times more frequent in Finnish individuals than in other Europeans and show geographical clustering comparable to Mendelian disease mutations that are characteristic of the Finnish population. We estimate that sequencing studies of populations without this unique history would require hundreds of thousands to millions of participants to achieve comparable association power

Haidinger’s brushes elicited at varying degrees of polarization rapidly and easily assesses total macular pigmentation

Macular pigments (MPs), by absorbing potentially toxic short-wavelength (400–500 nm) visible light, provide protection against photo-chemical damage thought to be relevant in the pathogenesis of age-related macular degeneration (AMD). A method of screening for low levels of MPs could be part of a prevention strategy for helping people to delay the onset of AMD. We introduce a new method for assessing MP density that takes advantage of the polarization-dependent absorption of blue light by MPs, which results in the entoptic phenomenon called Haidinger’s brushes (HB). Subjects were asked to identify the direction of rotation of HB when presented with a circular stimulus illuminated with an even intensity of polarized white light in which the electric field vector was rotating either clockwise or anti-clockwise. By reducing the degree of polarization of the stimulus light, a threshold for perceiving HB (degree of polarization threshold) was determined and correlated (r2=0.66) to macular pigment optical density assessed using dual-wavelength fundus autofluoresence. The speed and ease of measurement of degree of polarization threshold makes it well suited for large-scale screening of macular pigmentation

A hypothetico-deductive approach to assessing the social function of chemical signalling in a non-territorial solitary carnivore

The function of chemical signalling in non-territorial solitary carnivores is still relatively unclear. Studies on territorial solitary and social carnivores have highlighted odour capability and utility, however the social function of chemical signalling in wild carnivore populations operating dominance hierarchy social systems has received little attention. We monitored scent marking and investigatory behaviour of wild brown bears Ursus arctos, to test multiple hypotheses relating to the social function of chemical signalling. Camera traps were stationed facing bear ‘marking trees’ to document behaviour by different age sex classes in different seasons. We found evidence to support the hypothesis that adult males utilise chemical signalling to communicate dominance to other males throughout the non-denning period. Adult females did not appear to utilise marking trees to advertise oestrous state during the breeding season. The function of marking by subadult bears is somewhat unclear, but may be related to the behaviour of adult males. Subadults investigated trees more often than they scent marked during the breeding season, which could be a result of an increased risk from adult males. Females with young showed an increase in marking and investigation of trees outside of the breeding season. We propose the hypothesis that females engage their dependent young with marking trees from a young age, at a relatively ‘safe’ time of year. Memory, experience, and learning at a young age, may all contribute towards odour capabilities in adult bears