1,142 research outputs found
Dimmable Electronic Ballast for a Gas Discharge Lamp
Titanium dioxide (TiO2) is the most efficient photocatalyst for organic oxidative degradation. TiO2 is effective not only in aqueous solution, but also in nonaqueous solvents and in the gas phase. It is photostable, biologically and chemically inert, and non-toxic. Low-energy UV light (approximately 375 nm, UV-A) can be used to photoactivate TiO2. TiO2 photocatalysis has been used to mineralize most types of organic compounds. Also, TiO2 photocatalysis has been effectively used in sterilization. This effectiveness has been demonstrated by its aggressive destruction of microorganisms, and aggressive oxidation effects of toxins. It also has been used for the oxidation of carbon monoxide to carbon dioxide, and ammonia to nitrogen. Despite having many attractive features, advanced photocatalytic oxidation processes have not been effectively used for air cleaning. One of the limitations of the traditional photocatalytic systems is the ballast that powers (lights) the bulbs. Almost all commercial off-the-shelf (COTS) ballasts are not dimmable and do not contain safety features. COTS ballasts light the UV lamp as bright as the bulb can be lit, and this results in shorter bulb lifetime and maximal power consumption. COTS magnetic ballasts are bulky, heavy, and inefficient. Several iterations of dimmable electronic ballasts have been developed. Some manifestations have safety features such as broken-bulb or over-temperature warnings, replace-bulb alert, logbulb operational hours, etc. Several electronic ballast boards capable of independently lighting and controlling (dimming) four fluorescent (UV light) bulbs were designed, fabricated, and tested. Because of the variation in the market bulb parameters, the ballast boards were designed with a very broad range output. The ballast boards can measure and control the current (power) for each channel
Deformation Quantization: Quantum Mechanics Lives and Works in Phase-Space
Wigner's quasi-probability distribution function in phase-space is a special
(Weyl) representation of the density matrix. It has been useful in describing
quantum transport in quantum optics; nuclear physics; decoherence (eg, quantum
computing); quantum chaos; "Welcher Weg" discussions; semiclassical limits. It
is also of importance in signal processing.
Nevertheless, a remarkable aspect of its internal logic, pioneered by Moyal,
has only emerged in the last quarter-century: It furnishes a third,
alternative, formulation of Quantum Mechanics, independent of the conventional
Hilbert Space, or Path Integral formulations. In this logically complete and
self-standing formulation, one need not choose sides--coordinate or momentum
space. It works in full phase-space, accommodating the uncertainty principle.
This is an introductory overview of the formulation with simple illustrations.Comment: LaTeX, 22 pages, 2 figure
Comment on ``Conduction states in oxide perovskites: Three manifestations of Ti Jahn-Teller polarons in barium titanate''
In this comment to [S. Lenjer, O. F. Schirmer, H. Hesse, and Th. W. Kool,
Phys. Rev. B {\bf 66}, 165106 (2002)] we discuss the electronic structure of
oxygen vacancies in perovskites. First principles computations are in favour of
rather deep levels in these vacancies, and Lenjer et al suggest that the
electrons' interaction energy is negative, but data on electroconductivity are
against.Comment: 2 pages, no figure
On the Spectrum of Field Quadratures for a Finite Number of Photons
The spectrum and eigenstates of any field quadrature operator restricted to a
finite number of photons are studied, in terms of the Hermite polynomials.
By (naturally) defining \textit{approximate} eigenstates, which represent
highly localized wavefunctions with up to photons, one can arrive at an
appropriate notion of limit for the spectrum of the quadrature as goes to
infinity, in the sense that the limit coincides with the spectrum of the
infinite-dimensional quadrature operator. In particular, this notion allows the
spectra of truncated phase operators to tend to the complete unit circle, as
one would expect. A regular structure for the zeros of the Christoffel-Darboux
kernel is also shown.Comment: 16 pages, 11 figure
A dilemma in representing observables in quantum mechanics
There are self-adjoint operators which determine both spectral and
semispectral measures. These measures have very different commutativity and
covariance properties. This fact poses a serious question on the physical
meaning of such a self-adjoint operator and its associated operator measures.Comment: 10 page
Controlling of Iridium films using interfacial proximity effects
High precision calorimetry using superconducting transition edge sensors
requires the use of superconducting films with a suitable , depending on
the application. To advance high-precision macrocalorimetry, we require
low- films that are easy to fabricate. A simple and effective way to
suppress of superconducting Iridium through the proximity effect is
demonstrated by using Ir/Pt bilayers as well as Au/Ir/Au trilayers. While Ir/Au
films fabricated by applying heat to the substrate during Ir deposition have
been used in the past for superconducting sensors, we present results of
suppression on Iridium by deposition at room temperature in Au/Ir/Au trilayers
and Ir/Pt bilayers in the range of 20-100~mK. Measurements of the
relative impedance between the Ir/Pt bilayers and Au/Ir/Au trilayers fabricated
show factor of 10 higher values in the Ir/Pt case. These new films could
play a key role in the development of scalable superconducting transition edge
sensors that require low- films to minimize heat capacity and maximize
energy resolution, while keeping high-yield fabrication methods.Comment: 5 journal pages, 4 figure
Salivary MMP-9 in the detection of oral squamous cell carcinoma
Oral squamous cell carcinoma (OSCC) is the most common malignant tumour of the oral cavity. Detection of OSCC is currently based on clinical oral examination combined with histopathological evaluation of a biopsy sample. Direct contact between saliva and the oral cancer makes measurement of salivary metalloproteinase- 9 (MMP-9) an attractive alternative. In total, 30 OSCC patients and 30 healthy controls were included in this prospective study. Saliva samples from both groups were collected, centrifuged and supernatant fluid was subjected to ELISA for assessment of MMP-9. The median salivary MMP-9 values with interquartile range (IQR) of OSCC patients and the control group were statistically analysed using the Mann-Whitney U-test. The receiver operating characteristic (ROC) curve was constructed and the area under curve (AUC) was computed. The median absorbance MMP-9 value of the OSCC group was 0.186 (IQR=0.158) and that of control group was 0.156 (IQR=0.102). MMP-9 was significantly increased in the OSCC patients than in the controls by +19.2% (p=0.008). Median values in patients with recurrence and in patients with primary event were 0.233 (IQR=0.299) and 0.186 (IQR=0.134) respectively. MMP-9 was significantly increased in patients with primary event (p=0.017) compared to controls by +19.2%. No significant increase of MMP-9 level was detected when comparing patients with recurrence and healthy controls (+49.4%; p=0.074). The sensitivity value of MMP-9 was 100% whereas the specificity value was 26.7% with AUC of 0.698. The present data indicates that the elevation of salivary levels of MMP-9 may be a useful adjunctive diagnostic tool for detection of OSCC. However, further studies are necessary to provide scientific and clinical validation
The INCLUDE study: INtegrating and improving Care for patients with infLammatory rheUmatological DisordErs in the community; identifying multimorbidity: Protocol for a pilot randomized controlled trial.
Background: Patients with inflammatory rheumatic conditions such as rheumatoid arthritis, polymyalgia rheumatica and ankylosing spondylitis are at increased risk of common comorbidities such as cardiovascular disease, osteoporosis and anxiety and depression which lead to increased morbidity and mortality. These associated morbidities are often un-recognized and under-treated. While patients with other long-term conditions such as diabetes are invited for routine reviews in primary care, which may include identification and management of co-morbidities, at present this does not occur for patients with inflammatory conditions, and thus, opportunities to diagnose and optimally manage these comorbidities are missed. Objective: To evaluate the feasibility and acceptability of a nurse-led integrated care review (the INtegrating and improving Care for patients with infLammatory rheUmatological DisordErs in the community (INCLUDE) review) for people with inflammatory rheumatological conditions in primary care. Design: A pilot cluster randomized controlled trial will be undertaken to test the feasibility and acceptability of a nurse-led integrated primary care review for identification, assessment and initial management of common comorbidities including cardiovascular disease, osteoporosis and anxiety and depression. A process evaluation will be undertaken using a mixed methods approach including participant self-reported questionnaires, a medical record review, an INCLUDE EMIS template, intervention fidelity checking using audio-recordings of the INCLUDE review consultation and qualitative interviews with patient participants, study nurses and study general practitioners (GPs). Discussion: Success of the pilot study will be measured against the engagement, recruitment and study retention rates of both general practices and participants. Acceptability of the INCLUDE review to patients and practitioners and treatment fidelity will be explored using a parallel process evaluation. Trial Registration: ISRCTN12765345
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