Large-amplitude resonant combustion in liquid rocket engine chambers - Some aspects of initiation

Large amplitude, high frequency resonant combustion initiation in rocket engine chamber

Looking into phrasal verbs

The phrasal verb is a unique type of verb phrase that consists of a main verb, usually of only one or two syllables, followed by a particle, that works as a single semantic unit. Such meaning, however, is characteristically expressed in idomatic terms, which poses a formidable problem for students of English as a second language. To be understood, this meaning must be figuratively interpreted as well as literally translated

Mining masculinities in the Canadian military

Gender is a contested category of analysis, generally understood to describe the characteristics and practices of its end products, men and women. Alternatively, this interdisciplinary study of changing masculinity in the Canadian Forces conceptualizes gender as characterizing the social worlds that people inhabit, worlds through which they are constructed and reconstructed as gendered beings, and which they negotiate, change or resist. The military has been selected as the investigative terrain because military technology--a social system comprising human and material resources--has been under-researched as a matrix of gender in the West. The conceptual framework for this study draws on linkages between gender constructs and warfare practices in various small-scale societies, and on comparisons between the organization and practice of warfare in pre-state versus archaic state societies. The result of this comparative framework is the problematization of certain structural features of the contemporary Forces, features which address one of it core preoccupations: engendering and sustaining bellicosity in its combatants, and obviating their resistance. These technologically rationalized features, shown to be historically anomalous, are designed to control how soldiers think about and carry out their deadly work. The study employs a triangulated methodology to gather data from interviews, written texts, and participant observation. Narrative analysis of this data affords a gendered mapping of military social practice and thought, culminating in the military gendering of human lives and deaths. Women, in their multiple feminine incarnations, are revealed for the threats which they pose to the Forces' 'operational effectiveness'--constructed as homogeneously masculine. Herein lie the ideological and practical reasons why 'gender integration' in the Forces--ordered in a 1989 Canadian Human Rights Tribunal ruling--may be an oxymoron, and why women more readily resist military authoritarianism than men

Variational nodal perturbation calculations using simplified spherical harmonics

The simplified spherical harmonics (SP{sub N}) method has been used as an approximation to the transport equation in a number of situations. Recently, the SP{sub N} method has been formulated within the framework of the variational nodal method (VNM). Implementation in the VARIANT code indicated that for many two and three dimensional problems, near P{sub N} accuracy can be obtained at a fraction of the Cost. Perturbation methods offer additional computational cost reduction for reactor core calculations and are indispensable for performing a variety of calculations including sensitivity studies and the breakdown by components of reactivity worths. Here, we extend the perturbation method developed for the VNM in the full P{sub N} approximation to treat simplified spherical harmonics. The change in reactivity predicted by both first order and exact perturbation theory using the SP{sub N} approximation is demonstrated for a benchmark problem and compared to diffusion and full P{sub N} estimates

Investing in New Technology in Pulmonary Medicine–Navigating the Tortuous Path to Success.

The introduction of new technologies offer the promise to advance medicine. This occurs alongside improved efforts to control costs of healthcare by hospital administrators, Center for Medicare and Medicaid Services’ (CMS) pivot to value programs, and commercial payers’ efforts to reduce reimbursement. These trends present a challenge for the pulmonologist, among others, who must navigate increasingly complex and highly scrutinized evaluation processes used to secure new technologies. Healthcare providers are turning toward value assessments, while simultaneously tasked with a mission of offering state-of-the art technologies and services. Pulmonologists desiring new technologies are thus faced with increased scrutiny in their evaluation of costs and clinical data to support investments. Consideration of this scrutiny and further evidence to temper the evaluation will improve the likelihood of adoption and patient access to clinically-impactful technology. The identification of this evidence may provide – to both administrators and pulmonary clinicians – a comprehensive view of the clinical and economic benefits of such technologies. It is imperative that all parties involved in the decision process work collaboratively to deploy value-added and clinically-impactful technologies. While a physician group might invest in such new technologies, the capital required often leads such decisions to a larger organization such as a hospital, healthcare system, or privately owned entity. This article aims to provide a framework for pulmonary clinicians to better understand the processes that purchasers use to evaluate new technologies, the pressures that influence their consideration, and what resources may be leveraged towards success

Wideband E-shaped Patch Antennas for Advanced Wireless Terminals

Low-profile patch antennas have become ubiquitous in wireless terminals, especially as devices have become smaller and demand more functionality out of their RF subsystems. While their shape and size is attactive for many applications, their narrow bandwidth hinders their usage in many systems. With the rise of computer-aided design, many patch antenna design concepts have been presented with enhanced bandwidth capabilities. The E-shaped patch antenna, whose original shape presented in the early 2000’s resembles the letter E, offers compelling performance with reasonable manufacturing complexity. In it most basic form, this antenna was linearly polarized and either wideband or dual-band. Over the last two decades, many variations of the E-shaped patch have been presented in literature: circularly polarized, miniaturized, frequency reconfigurable, or even polarization reconfigurable. This paper summarizes these efforts in realizing novel functionalities with a relatively simple design geometry

Video Endoscopy for Laser Photoresection in Tracheobronchial Pathology: Some Considerations After 9 Years Experience With 2105 Treatments

Between 1984 and 1993 we performed 2105 laser treatments in 1210 patients: 52% of treatments were done for malignant pathology, 45% for benign tracheal stenoses and 3% were in a miscellaneous group. The procedure was carried out with a rigid bronchoscope under general anaesthesia. In patients with malignant tumors, it is a good palliative treatment—safe, well tolerated and with immediate results; it can be repeated as many times as needed with and is well accepted by the patient. In patients without tumors, this method avoids emergency tracheotomies. The long term results are now under evaluation