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1.
Ozone measurement based on the optical absorption of visible light at 603 nm using polymer optical fibres is investigated and tested. Comparisons with a commercial UV based sensor demonstrate the ability of the visible based sensor to measure high concentrations over a range 27-127 mg/litre. A resolution of 5 mg/litre is also demonstrated for this sensor. 相似文献
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R Fitzpatrick J Dawson M Boulton J McLean G Hart M Brookes 《Canadian Metallurgical Quarterly》1994,44(379):80-82
BACKGROUND: Primary care has an important role to play in the prevention and management of the human immunodeficiency virus (HIV). It has been suggested that homosexual men experience a variety of problems in relation to primary care. AIM: As part of a larger study, it was decided to examine the extent to which a sample of homosexually active men experienced difficulties in general practice and whether they consulted their general practitioner for problems related to HIV or the acquired immune deficiency syndrome (AIDS). METHOD: Homosexual men were recruited for interview in 1991-92 from a variety of sources including genitourinary clinics and homosexual organizations. RESULTS: Of 623 men registered with a general practitioner 44% had not informed their general practitioner of their sexual orientation and 44% of the 77 men who were HIV antibody positive, as confirmed by the study, had not informed their general practitioner of this fact. Men who viewed their practice as unsympathetic towards homosexual men were less likely to have informed their general practitioner of their sexual orientation or HIV status. The majority of men (87%) nevertheless viewed primary care as an appropriate source of HIV/AIDS advice. CONCLUSION: There is considerable scope for improvement in the acceptability of general practice to homosexual men. 相似文献
4.
S. M. Fitzpatrick D. Miller I. Weatherston J. N. McNeil 《Journal of chemical ecology》1985,11(2):207-215
Levels of benzaldehyde recovered from virginPseudaletia unipuncta (Haw.) males were not influenced by (1) the time hairpencils remained in the solvent (1-72 hr), (2) anesthetization or agitation of males prior to excision of hairpencils, or (3) the time (photophase or scotophase) that hairpencils were excised. Thus the interindividual variability observed is not a methodological artifact. Most males had similar concentrations in both hairpencils, although in some cases only one hairpencil contained pheromone. In one case, a male with partially extruded hairpencils had no benzaldehyde at all. Neither pupal weight nor hairpencil length proved to be reliable indicators of pheromone content.Contribution No. 373, Département de biologie, Université Laval. 相似文献
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M. E. Fitzpatrick M. T. Hutchings J. E. King D. M. Knowles P. J. Withers 《Metallurgical and Materials Transactions A》1995,26(12):3191-3198
The effects of a thermal residual stress field on fatigue crack growth in a silicon carbide particle-reinforced aluminum alloy
have been measured. Stress fields were introduced into plates of material by means of a quench from a solution heat-treatment
temperature. Measurements using neutron diffraction have shown that this introduces an approximately parabolic stress field
into the plates, varying from compressive at the surfaces to tensile in the center. Long fatigue cracks were grown in specimens
cut from as-quenched plates and in specimens which were given a stress-relieving overaging heat treatment prior to testing.
Crack closure levels for these cracks were determined as a function of the position of the crack tip in the residual stress
field, and these are shown to differ between as-quenched and stress-relieved samples. By monitoring the compliance of the
specimens during fatigue cycling, the degree to which the residual stresses close the crack has been evaluated.
formerly Research Student, Department of Materials Science and Metallurgy, University of Cambridge
formerly Lecturer, Department of Materials Science and Metallurgy, University of Cambridge
This article is based on a presentation made in the symposium entitled “Creep and Fatigue in Metal Matrix Composites” at the
1994 TMS/ASM Spring meeting, held February 28–March 3, 1994, in San Francisco, California, under the auspices of the Joint
TMS-SMD/ASM-MSD Composite Materials Committee. 相似文献
7.
Popovici E.M. Fitzpatrick P. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2003,49(12):3303-3307
We present a new algorithm for generic multiplicative computations of the form ab/c in GF(p/sup m/), including multiplication, inversion, squaring, and division. The algorithm is based on solving a sequence of congruences that are derived from the theory of Grobner bases in modules over the polynomial ring GF(p)[x]. Its corresponding hardware and software architectures can be successfully used in applications such as error control coding and cryptography. We describe a versatile circuit associated with the algorithm for the most important case p=2. The same hardware can be used for a range of field sizes thus permitting applications in which different levels of error control or of security are required by different classes of user. The operations listed are all performed by the hardware in the same number of clock cycles, which prevents certain side-channel attacks. The loss in performance by having 2m iterations for multiplication is compensated by the full parameterization of the Galois field and the ability to perform division and multiplication in parallel. 相似文献
8.
Tom Fitzpatrick 《电子测试》2005,(11):34-42
虽然目前的IC设计持续以惊人的速度复杂化,但设计者仍然希望可以通过先进的验证工作提高工作效率.所谓的先进验证工作便是将测试平台自动化(Test-Bench Automation)和正式属性检测(Formal Property Checking)两功能添加到功能验证(Functional Verification)的流程之中.本文将主要探讨其中的基本概念、价值以及使用方法,进而帮助读者了解. 相似文献
9.
Ge Y Fitzpatrick JM Dawant BM Bao J Kessler RM Margolin RA 《IEEE transactions on medical imaging》1996,15(4):418-428
Analysis of brain images often requires accurate localization of cortical convolutions. Although magnetic resonance (MR) brain images offer sufficient resolution for identifying convolutions in theory, the nature of tomographic imaging prevents clear definition of convolutions in individual slices. Existing methods for solving this problem rely on heuristic adaptation of brain atlases created from a small number of individuals. These methods do not usually provide high accuracy because of large biological variations among individuals. The authors propose to localize convolutions by linking realistic visualizations of the cortical surface with the original image volume. They have developed a system so that a user can quickly localize key convolutions in several visualizations of an entire brain surface. Because of the links between the visualizations and the original volume, these convolutions are simultaneously localized in the original image slices. In the process of the authors' development, they have implemented a fast and easy method for visualizing cortical surfaces in MR images, thereby making their scheme usable in practical applications. 相似文献
10.
Methods to fabricate planar capillary electrophoresis devices integrated with a postcolumn reactor in fused silica (quartz) and Pyrex glass are presented. Quartz is etched at ~1 μm/min with a 2.1:1 width-to-depth ratio using a Cr/Au/Cr metal mask and concentrated HF/HNO(3). On-chip postcolumn reaction of o-phthaldialdehyde (OPA) and amino acids gave theoretical plate numbers up to 83?000 and ~90 ms peak widths, corresponding to 14 plates/V and a 0.5 μm theoretical plate height. The reactor geometry caused only a 10% degradation in efficiency. 相似文献