Parasitic suppressing circuit

A circuit for suppressing parasitic oscillations across an inductor operating in a resonant mode is described. The circuit includes a switch means and resistive means connected serially across the inductor. A unidirectional resistive-capacitive network is also connected across the inductor and to the switch means to automatically render the switch means conducting when inductive current through the inductor ceases to flow

Development of an accurate wide range ultra high vacuum gauge calibration method

Accurate wide range ultrahigh vacuum gauge calibration method using pressure attenuation, atomic beam, and cryopumping techniques to evaluate system components and performanc

Development of an accurate wide range ultra high vacuum gauge calibration method, 29 June 1966 - 28 February 1968

Calibration method and ultrahigh vacuum components for ionization gage and mass spectromete

Experimental study of dynamic effects of crew motion in a Manned Orbital Research Laboratory /MORL/

Disturbance profiles of routine crew motion in simulated zero gravity environment of manned orbital research laborator

The interaction of Escherichia coli initiation factor 3 with coliphage-MS2 RNA

Imperial Users onl

On a Tree and a Path with no Geometric Simultaneous Embedding

Two graphs $G_1=(V,E_1)$ and $G_2=(V,E_2)$ admit a geometric simultaneous embedding if there exists a set of points P and a bijection M: P -> V that induce planar straight-line embeddings both for $G_1$ and for $G_2$. While it is known that two caterpillars always admit a geometric simultaneous embedding and that two trees not always admit one, the question about a tree and a path is still open and is often regarded as the most prominent open problem in this area. We answer this question in the negative by providing a counterexample. Additionally, since the counterexample uses disjoint edge sets for the two graphs, we also negatively answer another open question, that is, whether it is possible to simultaneously embed two edge-disjoint trees. As a final result, we study the same problem when some constraints on the tree are imposed. Namely, we show that a tree of depth 2 and a path always admit a geometric simultaneous embedding. In fact, such a strong constraint is not so far from closing the gap with the instances not admitting any solution, as the tree used in our counterexample has depth 4.Comment: 42 pages, 33 figure

A cold cathode ion source mass spectrometer employing ion counting techniques

Design and construction of mass spectrometer using cold cathode source of ions, quadrupole mass analyzer, and ion counting detector

Radiosensitizing and cytocidal effects on hypoxic cells of RO-07-0582, and repair of x-ray injury, in an experimental mouse tumour.

The delay in regrowth to 10 mm diameter of a transplanted carcinoma in mice was used to estimate the effect of the hypoxic-cell radiosensitizer Ro-07-0582. When 1 mg/g body wt. was given before a single dose of X-rays, a dose-enhancement ratio of 2-0 was found. When the drug was given immediately after irradiation, a large cytotoxic effect was observed, equivalent to an enhancement ratio of 1-3. These results were confirmed by determining the X-ray doses required for the local control of 50% of the tumours at 80 days after irradiation. The capacity of the tumour for repair of sublethal X-ray injury within 24 h was similar to that for several normal tissues

The effect of low-dose pre-operative X-irradiation of implanted mouse mammary carcinomas on local recurrence and metastasis.

Pre-operative X-irradiation of s.c. implanted first-generation mammary tumours in C3H mice, using either 500 rad or two fractions of 350 rad, produced no improvement in the success of surgery in causing local control or in reduction of distant metastases. The metastasis rate was just significantly higher after the two-fraction treatment of the implanted tumour than after surgical removal alone. The results are in agreement with previously published results on carcinomas and a sarcoma but contrast with those for murine lymphomas

Variability Flagging in the Wide-field Infrared Survey Explorer Preliminary Data Release

The Wide-field Infrared Survey Explorer Preliminary Data Release Source Catalog contains over 257 million objects. We describe the method used to flag variable source candidates in the Catalog. Using a method based on the chi-square of single-exposure flux measurements, we generated a variability flag for each object, and have identified almost 460,000 candidate sources that exhibit significant flux variability with greater than ~7σ confidence. We discuss the flagging method in detail and describe its benefits and limitations. We also present results from the flagging method, including example light curves of several types of variable sources including Algol-type eclipsing binaries, RR Lyr, W UMa, and a blazar candidate