3,152 research outputs found

    Monitor weather conditions for cloud seeding control

    Get PDF
    There are no author-identified significant results in this report

    AK-cut crystal resonators

    Get PDF
    Calculations have predicted the existence of crystallographically doubly rotated quartz orientations with turnover temperatures which are considerably less sensitive to angular misorientation then comparable AT- or BT-cuts. These crystals are arbitrarily designated as the AK-cut. Experimental data is given for seven orientations, phi-angle variations between 30-46 deg and theta-angle variations between 21-28 deg measured on 3.3-3.4 MHz fundamental mode resonators vibrating in the thickness shear c-mode. The experimental turnover temperatures of these resonators are between 80 C and 150 C, in general agreement with calculated values. The normalized frequency change as a function of temperature has been fitted with a cubic equation

    Confirming the existence of π-allyl-palladium intermediates during the reaction of meta photocycloadducts with palladium(ii) compounds

    Get PDF
    The transient existence of π-allyl-palladium intermediates formed by the reaction of Pd(OAc)2 and anisole-derived meta photocycloadducts has been demonstrated using NMR techniques. The intermediates tended to be short-lived and underwent rapid reductive elimination of palladium metal to form allylic acetates, however this degradation process could be delayed by changing the reaction solvent from acetonitrile to chloroform

    Use of ERTS-1 satellite data collection system in monitoring weather conditions for control of cloud seeding operations

    Get PDF
    There are no author-identified significant results in this report

    Relationships Between the Performance of Time/Frequency Standards and Navigation/Communication Systems

    Get PDF
    The relationship between system performance and clock or oscillator performance is discussed. Tradeoffs discussed include: short term stability versus bandwidth requirements; frequency accuracy versus signal acquisition time; flicker of frequency and drift versus resynchronization time; frequency precision versus communications traffic volume; spectral purity versus bit error rate, and frequency standard stability versus frequency selection and adjustability. The benefits and tradeoffs of using precise frequency and time signals are various levels of precision and accuracy are emphasized

    Monitor weather conditions for cloud seeding control

    Get PDF
    The author has identified the following significant results. The near real-time DCS platform data transfer to the time-share compare is a working reality. Six stations are now being automatically monitored and displayed with a system delay of 3 to 8 hours from time of data transmission to time of data accessibility on the computer. The DCS platform system has proven itself a valuable tool for near real-time monitoring of mountain precipitation. Data from Wolf Creek Pass were an important input in making the decision when to suspend seeding operations to avoid exceeding suspension criteria in that area. The DCS platforms, as deployed in this investigation, have proven themselves to be reliable weather resistant systems for winter mountain environments in the southern Colorado mountains

    Use of the LANDSAT-2 data collection system in the Colorado River basin weather modification program

    Get PDF
    The author has identified the following significant results. Many types of environmental sensors can be interfaced to the LANDSAT DCP. The LANDSAT field installations proved to be remarkably reliable, weather resistant, and cost effective units able to relay high quality data in near real time. The wind averaging system demonstrated the feasibility of transmitting averaged wind data, stored over a period of several hours, from a remote site

    Levels of soluble VCAM-1, soluble ICAM-1, and soluble E-selectin in patients with tuberculous pleuritis

    Get PDF
    Tuberculosis is characterized by the presence of activated mononuclear cells both in the peripheral circulation and in pleural fluid. Expression and up-regulation of adhesion molecules is the basis of cell-cell adhesion in granuloma formation and in leukocyte migration to the inflammatory site. Soluble isoforms of adhesion molecules have been described, and their expression at high levels indicated an activated state. The purpose of this study was to evaluate levels of soluble adhesion molecules in serum and pleural fluid from patients with tuberculous pleural effusions, compared with non-tuberculous pleural effusions. We analysed levels of soluble vascular cell adhesion molecule-1 (s.VCAM-1), soluble intercellular adhesion molecule-1 (s.ICAM-1), and soluble E-selectin (sE-selectin) in serum and pleural fluid from patients with tuberculous pleuritis, by sandwich ELISA. Serum levels of s.ICAM-1 and s.VCAM-1 in patients with tuberculosis were higher than those in healthy controls (p < 0.001). Levels of sE-selectin levels were in the normal range compared with control groups. In pleural fluid, levels of s.VCAM-1 and s.ICAM-1 were increased in pleural effusions. Patients with tuberculous pleural effusion exhibited high levels of s.ICAM-1 compared with patients with neoplastic pleural involvement. Up-regulation of s.VCAM-1 and s.ICAM-1 in serum, along with increased levels of sE-selectin in pleural effusions from tuberculous patients, may result in transmigration of activated inflammatory cells inducing pleural damage, which may contribute to the pathological processes involved

    Flying is the safest way to travel

    Get PDF
    Independent investigations of aviation accidents and incidents have been broadly accepted within the aviation sector throughout its history as a valuable tool to enhance safety. Such investigations enable the sector to learn by establishing the sequence of events that provides a satisfactory explanation of the accident leads to the drafting of recommendations to prevent reoccurrences. In addition, these investigations, which are publicly disseminated, encourage public confidence in the sector. Other transport sectors, including road, rail and water, have been slower in coming to enjoy the same acceptance of independent investigations; here, there is considerable variation amongst nations, and—with the exception of the International Civil Aviation Organization agreement—almost no international consistency. This article examines why aviation has had a different tradition in this regard. Reasons are found in parallel growth of aviation technology and the philosophy of investigative bodies, the inherently international aspect of commercial aviation, and the role of public and political pressure following major accidents. The safety investigative orientation of the aviation sector is gradually expanding to other transport sections and beyond that to other sectors such as fixed site production plants, health care, and management of natural disasters. With the newly installed Safety Investigation Board, the Netherlands has arguably placed itself at the head of this league table

    Sports-related brain injury in the general population: An epidemiological study

    Get PDF
    Objectives To determine the incidence, nature and severity of all sports-related brain injuries in the general population. Design Population-based epidemiological incidence study. Methods Data on all traumatic brain injury events sustained during a sports-related activity were extracted from a dataset of all new traumatic brain injury cases (both fatal and non-fatal), identified over a one-year period in the Hamilton and Waikato districts of New Zealand. Prospective and retrospective case ascertainment methods from multiple sources were used. All age groups and levels of traumatic brain injury severity were included. Details of the registering injuries and recurrent injuries sustained over the subsequent year were obtained through medical/accident records and assessment interviews with participants. Results Of 1369 incident traumatic brain injury cases, 291 were identified as being sustained during a sports-related activity (21% of all traumatic brain injuries) equating to an incidence rate of 170 per 100,000 of the general population. Recurrent injuries occurred more frequently in adults (11%) than children (5%). Of the sports-related injuries 46% were classified as mild with a high risk of complications. Injuries were most frequently sustained during rugby, cycling and equestrian activities. It was revealed that up to 19% of traumatic brain injuries were not recorded in medical notes. Conclusions Given the high incidence of new and recurrent traumatic brain injury and the high risk of complications following injury, further sport specific injury prevention strategies are urgently needed to reduce the impact of traumatic brain injury and facilitate safer engagement in sports activities. The high levels of ‘missed’ traumatic brain injuries, highlights the importance in raising awareness of traumatic brain injury during sports-related activity in the general population
    corecore