Device for quickly sensing the amount of O2 in a combustion product gas

A sensing device comprising an O2 sensor, a pump, a compressor, and a heater is provided to quickly sense the amount of O2 in a combustion product gas. A sample of the combustion product gas is compressed to a pressure slightly above one atmosphere by the compressor. Next, the heater heats the sample between 800 C and 900 C. Next, the pump causes the sample to be flushed against the electrode located in O2 sensor 6000 to 10,000 times per second. Reference air at approximately one atmosphere is provided to the electrode of O2 sensor. Accordingly, the O2 sensor produces a voltage which is proportional to the amount of oxygen in the combustion product gas. This voltage may be used to control the amount of O2 entering into the combustion chamber which produces the combustion product gas

Solid state crystal physics at very low temperatures

The properties of nearly perfect crystals was studied at cryogenic temperatures. A large Helium 3 and Helium 4 dilution refrigerator has been assembled, and is described. A cryostat suitable for cooling a 35 liter volume to .020 Kelvin was designed and constructed, together with instrumentation to observe the properties of nearly perfect crystals

Properties of large nearly perfect crystals at very low temperatures

A liquid helium cryostat of a size and construction unavailable commercially, was built for use in measuring the Q of several materials at milli-Kelvin temperatures. The design and testing of the cryostat is described as well as the design of the experiment vacuum chamber and adaptor for the dilution refrigerator insert. Theory, design, and testing are also discussed for the magnetic coils built to levitate the materials so as to isolate them and increase the measured Q. A four point suspension with capacitor end plates as the transducer was used to obtain preliminary Q measurements of 6061 aluminum alloy and single crystal silicon. Results are tabulated

The Outer Limits of Galaxy Clusters: Observations to the Virial Radius with Suzaku, XMM, and Chandra

The outskirts of galaxy clusters, near the virial radius, remain relatively unexplored territory and yet are vital to our understanding of cluster growth, structure, and mass. In this presentation, we show the first results from a program to constrain the state of the outer intracluster medium (ICM) in a large sample of galaxy clusters, exploiting the strengths of three complementary X-ray observatories: Suzaku (low, stable background), XMM-Newton (high sensitivity), and Chandra (good spatial resolution). By carefully combining observations from the cluster core to beyond r_200, we are able to identify and reduce systematic uncertainties that would impede our spatial and spectral analysis using a single telescope. Our sample comprises nine clusters at z ~ 0.1-0.2 fully covered in azimuth to beyond r_200, and our analysis indicates that the ICM is not in hydrostatic equilibrium in the cluster outskirts, where we see clear azimuthal variations in temperature and surface brightness. In one of the clusters, we are able to measure the diffuse X-ray emission well beyond r_200, and we find that the entropy profile and the gas fraction are consistent with expectations from theory and numerical simulations. These results stand in contrast to recent studies which point to gas clumping in the outskirts; the extent to which differences of cluster environment or instrumental effects factor in this difference remains unclear. From a broader perspective, this project will produce a sizeable fiducial data set for detailed comparison with high-resolution numerical simulations.Comment: 8 pages, 6 figures. To appear in the proceedings of the Suzaku 2011 Conference, "Exploring the X-ray Universe: Suzaku and Beyond.

Quality Suckler Beef From Low and High Input Grassland Management Systems

End of Project ReportSpring calving cows were used in the years 1997 to 2003 in the development of planned low and high input systems of suckler beef production.The main objective of the study was to compare a semiintensive Grange (standard): system of suckler beef production with a more extensive REPS (Rural Environment Protection Scheme) compatible system. In the standard system the stocking rate was 0.80 ha per cow unit (cow plus heifer and steer progeny to slaughter at 20 and 23/24 months of age, respectively, plus replacements or its equivalent), a nitrogenous fertiliser application rate of 210 kg per ha and two silage harvests each year amounting to the equivalent of 87% of the total area harvested. The REPS system involved a 25% lower stocking rate, an annual nitrogen fertiliser application rate of 90 to 100 kg per ha and one silage harvest (portion in late May to provide good silage for the progeny and the remainder in June to provide lower quality silage for cows) amounting to 58% of the total area harvested. Between 1997 and 2000 the cow herd were Limousin x Friesians (LF) and Simmental x (Limousin x Friesians) (SLF). A herd of first calvers were introduced in 2001 and 2002 which in addition to LF and SLF included Limousin x (Limousin x Friesians), purebred Limousin and purebred Charolais. Charolais (or Simmental) sires were used on mature cows. Replacement heifers were bred to calve at 2 years of age using an easy calving Limousin bull. Concentrate inputs per animal were the same in the two systems. The main findings of the study were: • The mean nitrogenous application rates were 210 and 98 kg per ha in the standard and REPS systems, respectively. • Mean dry matter digestibility of the first-cut silages harvested early (May 19 to May 29), late (June 5 to June 13) and the second cut silage in the standard system (harvested in July/early August) were 716, 690 and 674 g/kg, respectively. • When averaged throughout two grazing seasons there was no difference between the standard and REPS systems in pregrazing or post-grazing sward heights. When examined over one grazing season the only major difference between the grazing areas was that the pasture crude protein content was higher in the standard system in both the pre-grazed (205 and 159 g/kg) and post-grazed (172 v 141 g/kg) swards. Cow liveweight and body condition score gains at pasture and calf gains from birth to weaning were the same for both systems. Carcass weights of the progeny were the same for the standard and REPS systems

FLOWERING LOCUS C -dependent and -independent regulation of the circadian clock by the autonomous and vernalization pathways

Background The circadian system drives pervasive biological rhythms in plants. Circadian clocks integrate endogenous timing information with environmental signals, in order to match rhythmic outputs to the local day/night cycle. Multiple signaling pathways affect the circadian system, in ways that are likely to be adaptively significant. Our previous studies of natural genetic variation in Arabidopsis thaliana accessions implicated FLOWERING LOCUS C (FLC) as a circadian-clock regulator. The MADS-box transcription factor FLC is best known as a regulator of flowering time. Its activity is regulated by many regulatory genes in the "autonomous" and vernalization-dependent flowering pathways. We tested whether these same pathways affect the circadian system. Results Genes in the autonomous flowering pathway, including FLC, were found to regulate circadian period in Arabidopsis. The mechanisms involved are similar, but not identical, to the control of flowering time. By mutant analyses, we demonstrate a graded effect of FLC expression upon circadian period. Related MADS-box genes had less effect on clock function. We also reveal an unexpected vernalization-dependent alteration of periodicity. Conclusion This study has aided in the understanding of FLC's role in the clock, as it reveals that the network affecting circadian timing is partially overlapping with the floral-regulatory network. We also show a link between vernalization and circadian period. This finding may be of ecological relevance for developmental programing in other plant species