24,758 research outputs found
An efficient prebreathing apparatus for humans during decompression
Portable prebreathing system was developed which recirculates and reconditions respiratorily exhaled oxygen. Apparatus reduces fire hazards, simplifies prebreathing procedures, and does not require extensive enclosure venting system usage
Induction of disease resistance to anthracnose in cucumber
Imperial Users onl
A critical analysis of the hydrino model
Recently, spectroscopic and calorimetric observations of hydrogen plasmas and
chemical reactions with them have been interpreted as evidence for the
existence of electronic states of the hydrogen atom with a binding energy of
more than 13.6 eV. The theoretical basis for such states, that have been dubbed
hydrinos, is investigated. We discuss both, the novel deterministic model of
the hydrogen atom, in which the existence of hydrinos was predicted, and
standard quantum mechanics. Severe inconsistencies in the deterministic model
are pointed out and the incompatibility of hydrino states with quantum
mechanics is reviewed.Comment: 9 page
Computer modeling of rocket engine ignition transients Final report
Computer modeling of rocket engine ignition transient
The role of regulatory mechanisms for control of plant diseases and food security — case studies from potato production in Britain
Being aware of the potentially devastating impacts of plant diseases on food security, governments have designed and employ plant health legislation to prevent or inhibit the worst impacts. The development of such policies in Britain, and latterly in Europe, can be closely linked to disease events that have occurred in the potato sector. We analyse early and current examples of policies governing potato diseases in Britain to identify the decision processes leading to the implementation of such phytosanitary policies and how they have evolved over time and in response to different disease threats. Reasons for developing and implementing phytosanitary policies include the desire to prevent pathogens being introduced (entering and establishing in a new area), the protection of export markets, and the lack of effective control measures. Circumstances in which regulatory policies would not be appropriate could include situations where a disease is already widely distributed, unacceptable costs, lack of exclusion measures, or difficulties of disease diagnosis. We conclude that in general, government policies have worked well in protecting British potato growing over the last one hundred years, despite of the failures of some of the policies discussed here. They have also contributed much to the development of plant health policies for other crops. Voluntary grower initiatives are a new mechanism complementing existing formal policies with an additional level of security that allows individual growers to take on additional responsibility rather than relying entirely on government legislation
Transients influencing rocket engine ignition and popping Interim report
Engine design and operating parameters studied for effects on rocket engine ignition and poppin
Spectroscopic study of unique line broadening and inversion in low-pressure microwave generated water plasmas
It was demonstrated that low pressure (~0.2 Torr) water vapor plasmas
generated in a 10 mm inner diameter quartz tube with an Evenson microwave
cavity show at least two features which are not explained by conventional
plasma models. First, significant (> 0.25 nm) hydrogen Balmer_ line broadening,
of constant width, up to 5 cm from the microwave coupler was recorded. Only
hydrogen, and not oxygen, showed significant line broadening. This feature,
observed previously in hydrogen-containing mixed gas plasmas generated with
high voltage dc and rf discharges was explained by some researchers to result
from acceleration of hydrogen ions near the cathode. This explanation cannot
apply to the line broadening observed in the (electrodeless) microwave plasmas
generated in this work, particularly at distances as great as 5 cm from the
microwave coupler. Second, inversion of the line intensities of both the Lyman
and Balmer series, again, at distances up to 5 cm from the coupler, were
observed. The line inversion suggests the existence of a hitherto unknown
source of pumping of the optical power in plasmas. Finally, it is notable that
other aspects of the plasma including the OH* rotational temperature and low
electron concentrations are quite typical of plasmas of this type.Comment: 27 pages, 7 figure
Oligonucleotide sequences forming short self-complimentary hairpins can expedite the down-regulation of Coprinopsis cinerea genes
Gene silencing in fungi is often induced by dsRNA hairpin forming constructs the preparation of which can require multiple cloning steps. To simplify gene silencing in the filamentous fungi we have evaluated a high throughput cloning method for target sequences using the homobasidiomycete Coprinopsis cinerea, the GFP reporter and a commercially available vector system. The pSUPER RNAi System™, which was developed for mammalian experiments, exploits the human H1 Polymerase III (Pol III) RNA gene promoter and expedites cloning/expression of specific user-defined oligonucleotide sequences to form short self-complimentary hairpins. Transformation of C. cinerea with pSUPER constructs harboring specific oligonucleotides (19 nt stem length) enabled recovery of transformants with reduced transcripts of the GFP transgene, that were less fluorescent in protein assays and microscopic phenotypes. This technological advance should expedite functional genomic studies in C. cinerea and has wider potential for utility in other homobasidiomycete and filamentous fungi
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