42,224 research outputs found
GE MOD-1 noise study
Noise studies of the MOD-1 Wind Turbine Generator are summarized, and a simple mathematical noise is presented which is adequate to correlate the sound levels found near the machine. A simple acoustic measure is suggested for use in evaluating far field sound levels. Use of this measure as input to a currently available sound complaint prediction program is discussed. Results of a recent statistical survey relative to the far field variation of this acoustic measure because of atmospheric effects are described
The Path to Gun Control in America Goes through Political Philosophy
This essay argues that gun control in America is a philosophical as well as a policy debate. This explains the depth of acrimony it causes. It also explains why the technocratic public health argument favored by the gun control movement has been so unsuccessful in persuading opponents and motivating supporters. My analysis also yields some positive advice for advocates of gun control: take the political philosophy of the gun rights movement seriously and take up the challenge of showing that a society without guns is a better society, not merely a safer one
Reidentifying hardware after loss of serial number
System traces fabrication and inspection records of special hardware back to the raw material. Reidentification of hardware, after loss of serial numbers, is established by X raying all parts again and comparing the new film with the original, whose numbers were previously recorded on serialized documents
Transformation without Paternalism
Human development is meant to be transformational in that it aims to improve people's lives by enhancing their capabilities. But who does it target: people as they are or the people they will become? This paper argues that the human development approach relies on an understanding of personal identity as dynamic rather than as static collections of preferences, and that this distinguishes human development from conventional approaches to development. Nevertheless, this dynamic understanding of personal identity is presently poorly conceptualized and this has implications for development practice. We identify a danger of paternalism and propose institutionalizing two procedural principles as side constraints on development policies and projects: the principle of free prior informed consent and the principle of democratic development
Palliative care for people with non-malignant lung disease: summary of current evidence and future direction
Background: The physical and psychosocial needs of patients with chronic non-malignant lung disease are comparable to those with lung cancer. This article will focus on chronic obstructive pulmonary disease, interstitial lung disease and cystic fibrosis as examples of life-limiting, non-curable and non-malignant lung diseases. The need for supportive and palliative care: Recent national guidance has demanded that palliative care is inclusive of all patients with life-limiting disease, irrespective of diagnosis, and that specialist palliative care teams are involved in the management of patients on a basis of need rather than prognosis. What is known: Despite medical therapy, most patients with moderate to severe chronic obstructive pulmonary disease, interstitial lung disease and cystic fibrosis experience pain, fatigue and dyspnoea, with the majority not getting relief from dyspnoea towards the end of life. Furthermore, dyspnoea causes social isolation and difficulty performing activities of daily living and impairs quality of life. There is an increasing evidence base for the assessment of supportive and palliative care needs, symptom interventions, prognostication, models of service delivery and implications of these for clinical practice and research in non-malignant lung diseases. What is unknown: Despite advances, much still remains unknown regarding assessment, management and prognostication in individual chronic non-malignant lung diseases. Although different service models are being used in clinical practice, the optimal model(s) of service delivery remain unknown. Implication for future research, policy and practice: We describe key areas for further research, which include the need for large, high-quality trials of pharmacological and non-pharmacological interventions and their combinations as well as evaluation of the efficacy and cost-effectiveness of models of care. As access to palliative care is poor for these patients, the barriers to referral need to be understood and reduced, which along with effective working between palliative care teams, with respiratory services backup, should optimise delivery of care in patients with life-limiting non-malignant lung disease
Mode-matching analysis of a shielded rectangular dielectric-rod waveguide
Rectangular cross-section dielectric waveguides are widely used at millimeter wavelengths. In addition, shielded
dielectric resonators having a square cross-section are often used as filter elements, however there is almost no information available on the effect of the shield. Rectangular or square dielectric waveguide is notoriously difficult to analyze, because of the singular behaviour of the fields at the corners. Most published analyses are for materials with a low dielectric constant, and do not include the effects of a shield.
This paper describes a numerically efficient mode matching method for the analysis of shielded dielectric rod waveguide, which is applicable to both low and high dielectric constant materials. The effect of the shield on the propagation behaviour is studied. The shield dimensions
may be selected such that the shield has a negligible effect, so that results can be compared with free space data. The results are verified by comparison with several sets of published data, and have been confirmed by measurement for a nominal 'e' r of 37.4
Validation of a Temperate Fourth Planet in the K2-133 Multi-planet System
We present follow-up observations of the K2-133 multi-planet system.
Previously, we announced that K2-133 contained three super-Earths orbiting an
M1.5V host star - with tentative evidence of a fourth outer-planet orbiting at
the edge of the temperate zone. Here we report on the validation of the
presence of the fourth planet, determining a radius of
R. The four planets span the radius gap of the exoplanet population,
meaning further follow-up would be worthwhile to obtain masses and test
theories of the origin of the gap. In particular, the trend of increasing
planetary radius with decreasing incident flux in the K2-133 system supports
the claim that the gap is caused by photo-evaporation of exoplanet atmospheres.
Finally, we note that K2-133 e orbits on the edge of the stars temperate zone,
and that our radius measurement allows for the possibility that this is a rocky
world. Additional mass measurements are required to confirm or refute this
scenario.Comment: Accepted for publication in MNRA
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Computational modelling of cracks in viscoplastic media
A newly developed numerical model is used to simulate propagating cracks in a strain softening viscoplastic medium. The model allows the simulation of displacement discontinuities independently of a finite element mesh. This is possible using the partition of unity concept, in which fracture is treated as a coupled problem, with separate variational equations corresponding to the continuous and discontinuous parts of the displacement field. The equations are coupled through the dependence of the stress field on the strain state. Numerical examples show that allowing displacement discontinuities in a viscoplastic Von Mises material can lead to a failure mode that differs from a continuum-only model
Three small transiting planets around the M dwarf host star LP 358-499
We report on the detection of three transiting small planets around the
low-mass star LP 358-499 (K2-133), using photometric data from the Kepler-K2
mission. Using multiband photometry, we determine the host star to be an early
M dwarf with an age likely older than a Gigayear. The three detected planets
K2-133 b, c, and d have orbital periods of ca. 3, 4.9 and 11 days and transit
depths of ca. 700, 1000 and 2000 ppm, respectively. We also report a planetary
candidate in the system (EPIC 247887989.01) with a period of 26.6 days and a
depth of ca. 1000 ppm, which may be at the inner edge of the stellar habitable
zone, depending on the specific host star properties. Using the transit
parameters and the stellar properties, we estimate that the innermost planet
may be rocky. The system is suited for follow-up observations to measure
planetary masses and JWST transmission spectra of planetary atmospheres.Comment: Accepted for publication in MNRAS Letters. Replaced previous arXiv
version with final submitted versio
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