Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET

The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR

Relationship of edge localized mode burst times with divertor flux loop signal phase in JET

A phase relationship is identified between sequential edge localized modes (ELMs) occurrence times in a set of H-mode tokamak plasmas to the voltage measured in full flux azimuthal loops in the divertor region. We focus on plasmas in the Joint European Torus where a steady H-mode is sustained over several seconds, during which ELMs are observed in the Be II emission at the divertor. The ELMs analysed arise from intrinsic ELMing, in that there is no deliberate intent to control the ELMing process by external means. We use ELM timings derived from the Be II signal to perform direct time domain analysis of the full flux loop VLD2 and VLD3 signals, which provide a high cadence global measurement proportional to the voltage induced by changes in poloidal magnetic flux. Specifically, we examine how the time interval between pairs of successive ELMs is linked to the time-evolving phase of the full flux loop signals. Each ELM produces a clear early pulse in the full flux loop signals, whose peak time is used to condition our analysis. The arrival time of the following ELM, relative to this pulse, is found to fall into one of two categories: (i) prompt ELMs, which are directly paced by the initial response seen in the flux loop signals; and (ii) all other ELMs, which occur after the initial response of the full flux loop signals has decayed in amplitude. The times at which ELMs in category (ii) occur, relative to the first ELM of the pair, are clustered at times when the instantaneous phase of the full flux loop signal is close to its value at the time of the first ELM

Specific identification and enumeration of Acetobacter diazotrophicus in sugarcane

An indirect ELISA specific for the identification and enumeration of Acetobacter diazotrophicus was developed. The specificity and sensitivity of the ELISA relied on the optimal dilutions of the IgG and the enzyme conjugateand the adsorption of the IgG with Acetobacter pasteurianus. 106-107 Acetobacter diazotrophicus cells were found to be present g-1 of dry roots, rhizosphere soils, leaves or stems of sugarcane plants. Sugarcane setts (stem cuttings used as seed pieces) and non-rhizosphere soils have much lower populations of this species which could only be detected after enrichment in semisolid sucrose medium by the ELISA. This bacterium could not be detected from grasses even after enrichment in semisolid sucrose medium

Specific association of diazotrophic acetobacters with sugarcane

By repeated subculturing in N-free semisolid sucrose medium, diazotrophic acetobacters were isolated from sugarcane roots or soil collected from four regions of Queensland, Australia. No such organisms were isolated from other grasses from the same locations. It was suggested that these microorganisms are specifically associated with sugarcane because they preferred high concentrations of sucrose for growth and N2 fixation and did not utilize common amino acids or organic acids for growth

Factors influencing the adsorption of bacteria to magnetite in water and wastewater

The adsorption of bacteria to a magnetite preparation used in a new water clarification process has been studied. It was found that bacteria adsorbed rapidly and in large numbers to magnetite. Adsorption was best in the range pH 3-6 in the absence of calcium and magnesium, but the range was extended to pH 10 in the presence of these two cations. These cations also interfered with the desorption of bacterial cells. The adsorption of bacteria from a wastewater was also studied

Tolerance of the nitrogen-fixing system of Azotobacter vinelandii for four commonly used pesticides

The effects of two insecticides, DDT and lindane, and two herbicides, Dalapon-Na and 2, 4, 5-T, upon the growth and nitrogen-fixing capacity of Azotobacter vinelandii in pure culture were investigated using concentrations of the pesticides equivalent to the usual field application rates, and fifty times these levels. The acetylene reduction technique was used to assay nitrogen fixation. No significant effects of the pesticides at either concentration were detected upon growth or acetylene reduction

Cytotoxic and haemagglutinating activities of motile Aeromonas species

Cytotoxic and haemagglutinating properties were determined in 114 Aeromonas strains isolated from various sites in slaughtered lambs and from processed lamb meat. Cytotoxic activity on Vero cells was observed in 48 (42%) of the strains. It was more common in A. sobria and A. hydrophila isolates than with A. caviae isolates. Haemagglutination (HA) activity was found frequently in motile aeromonads irrespective of species; it was present in 50% of A. sobria strains, 51% of A. hydrophila strains and 48% of A. caviae strains. HA was inhibited by fucose, galactose and mannose at low concentration, and in most cases, two or three of these sugars were inhibitory. A significant association was found between certain HA-inhibition patterns and the production of cytotoxin by Aeromonas spp

Effect of lindane and DDT on populations of protozoa in a garden soil

Applications of lindane and p,p'-DDT to a garden soil at rates of 5 and 50 parts/106 inhibited soil protozoa. The inhibitory effect of DDT was still apparent 3 months after application but that of lindane, although noted at the time of application and after 1 month, was not detectable after 2 months' incubation of the treated soil

Removal of bacteria from water by adsorption to magnetite

The adsorption of bacterial cells to magnetite and their subsequent desorption has been studied. It was found that three adsorption stages reduce the numbers of bacteria in a suspension by five log cycles. Removal of calcium and magnesium from the magnetite surface by acid washing resulted in improved desorption of the bacterial cells