Influence of Alloying Elements Upon the Solidification Interval of CA6NM Cast Martensitic Stainless Steel

The influence of different Cr and C contents upon the solidification interval of ASTM A352M-06 Grade CA6NM cast martensitic stainless steel has been investigated using computational thermodynamics, and checked against DTA measurements in samples taken from 13 large cast parts, in order to identify potential sources for improvement on the part castability. Calculation results suggest, indeed, that this would be the case for C: when its content increases from 0.018 to 0.044 wt.% C (within the allowed range in the alloy specification), the solidification intervals increases from 25 to 43 K, which suggests improved castability with decreasing C contents. DTA results, however, do not support this prediction, showing a fairly constant solidification interval around 23 K for all investigated samples. The results are discussed both regarding the impact in alloy processing and the fitness of the existing databases to reproduce experimental results in these limiting cases.

The effect of solidification rate on the structure of magnesium-aluminium eutectic grains

A magnesium-aluminium alloy of eutectic composition was solidified under two different cooling conditions, producing a low and a high growth rate of the eutectic solid-liquid interface. The high growth rate specimen contained smaller eutectic grains and cells, with a smaller interphase spacing compared with the low growth rate specimen. The high growth rate specimen also contained some primary Mg17Al12 dendrites, suggesting that the coupled zone is skewed towards the Mg phase with increased undercooling, A lamellar eutectic morphology was observed in the low growth rate specimen, while the morphology was fibrous in the high growth rate specimen.

Coordinated Cluster and ground-based instrument observations of transient changes in the magnetopause boundary layer during an interval of predominantly northward IMF: relation to reconnection pulses and FTE signatures

We study a series of transient entries into the low-latitude boundary layer (LLBL) of all four Cluster spacecraft during an outbound pass through the mid-afternoon magnetopause ([X(GSM), Y(GSM), Z(GSM)] approximate to [2, 7, 9] R(E)). The events take place during an interval of northward IMF, as seen in the data from the ACE satellite and lagged by a propagation delay of 75 min that is well-defined by two separate studies: (1) the magnetospheric variations prior to the northward turning (Lockwood et al., 2001, this issue) and (2) the field clock angle seen by Cluster after it had emerged into the magnetosheath (Opgenoorth et al., 2001, this issue). With an additional lag of 16.5 min, the transient LLBL events cor-relate well with swings of the IMF clock angle (in GSM) to near 90degrees. Most of this additional lag is explained by ground-based observations, which reveal signatures of transient reconnection in the pre-noon sector that then take 10-15 min to propagate eastward to 15 MLT, where they are observed by Cluster. The eastward phase speed of these signatures agrees very well with the motion deduced by the cross-correlation of the signatures seen on the four Cluster spacecraft. The evidence that these events are reconnection pulses includes: transient erosion of the noon 630 nm (cusp/cleft) aurora to lower latitudes; transient and travelling enhancements of the flow into the polar cap, imaged by the AMIE technique; and poleward-moving events moving into the polar cap, seen by the EISCAT Svalbard Radar (ESR). A pass of the DMSP-F15 satellite reveals that the open field lines near noon have been opened for some time: the more recently opened field lines were found closer to dusk where the flow transient and the poleward-moving event intersected the satellite pass. The events at Cluster have ion and electron characteristics predicted and observed by Lockwood and Hapgood (1998) for a Flux Transfer Event (FTE), with allowance for magnetospheric ion reflection at Alfvenic disturbances in the magnetopause reconnection layer. Like FTEs, the events are about 1 R(E) in their direction of motion and show a rise in the magnetic field strength, but unlike FTEs, in general, they show no pressure excess in their core and hence, no characteristic bipolar signature in the boundary-normal component. However, most of the events were observed when the magnetic field was southward, i.e. on the edge of the interior magnetic cusp, or when the field was parallel to the magnetic equatorial plane. Only when the satellite begins to emerge from the exterior boundary (when the field was northward), do the events start to show a pressure excess in their core and the consequent bipolar signature. We identify the events as the first observations of FTEs at middle altitudes.

Identification of the Mass and Stability Interval of Strong Potential in Heavy Mesons

In this paper, we have calculated the masses of mesons containing t-quark and their spins' coupling coefficients. This was achieved by solving Lippmann-Schwinger equation for the quark-antiquark bound state of heavy mesons in configuration space. Heavy meson masses submitted criteria for the strong nuclear interactive potential between two quarks. We investigated the stability of a few suitable potentials and offered the best of these potentials for heavy mesons.

Efficacy and total release interval of mating disruption pheromone on the control of pink bollworm - Pectinophora Gossypiella - in cotton under field conditions in Brazil

This experiment was developed in order to evaluation the efficiency of pheromone to control the pink bollworm and the total time of its release in cotton field. The experiment was installed in field conditions, in Chapadao do Sul/SP/Brazil, from January to April, 1998. The treatments consisted of 2 areas, being one of 30ha, where it was applied the pheromone and another of 10ha that was chosen as control area and did not receive pheromone. In the treated area, the laboratory synthesized sex pheromone (PB-Rope) was used thought of dispensers that allowed the slow and gradual release of the active substance. A total of 250 dispenser per hectare were evenly hand distributed in the area. The dispensers were wrapped around the plants. Both areas (treated area and untreated area) were monitored by delta trap. For evaluation of the boll damage, the treatment area was divided into 4 sub-areas. Twenty five green bolls were collected at random from each sub-area at 48 and 65 days after pheromone treatment. Bolls were cracked open by hand, and number of the bolls with symptoms of pink bollworm attacks was recorded. For evaluation of the productivity four areas were demarcated in each treatment, where all fibers and seeds harvested were weighted. Release rate of pheromone from dispenser was evaluated through of the weigh of the dispensers. Were marked and weighed in analytic scale, 20 dispensers contend the pheromone, being placed 10 dispensers under the cotton plants in treated area and other 10 dispensers in an open area. To every 15 days the dispensers were retired and weighed in analytic scale and soon after put back in the field in the same places. The results showed that only one application of mating disrupt pheromone, used in a dosage of 250 dispenser/ha, reached 80% of control for pink bollworm. the release period of pheromone from dispenser, after the application, was 120 days.

Intensity and interval of recovery in strength exercise influences performance: salivary lactate and alpha amylase as biochemical markers: a pilot study

Purpose The aim of the present study was to evaluate the effects of intensity and interval of recovery on performance in the bench press exercise, and the response of salivary lactate and alpha amylase levels. Methods Ten sportsman (aged 29 ± 4 years; body mass index 26 ± 2 kg/cm2 ) were divided in two groups: G70 (performing a bench press exercise at 70 % one repetition maximum—1RM), and G90 (performing a bench press exercise at 90 %—1RM). All groups were engaged in three intervals of recovery (30, 60 and 90 s). The maximum number of repetitions (MNR) and total weight lifted were computed, and saliva samples were collected 15 min before and after different intervals of recovery. For the comparison of the performance and biochemistry parameters, ANOVA tests for repeated measurements were conducted, with a significance level set at 5 %. Results In G70, the 30 s MNR was lower than the 60 and 90 s intervals of recovery (p\0.05) and the MNR with the 60 s interval of recovery was lower than the 90 s interval of recovery (p\0.041). Similarly, in G90 with the 30 s of interval of recovery, the sets were lower than observed with the 60 and 90 s (p\0.05), and MNR with the 60 s interval of recovery was lower than the 90 s interval of recovery (p\0.05). The salivary lactate showed an increase after exercise (p\0.05) when compared with the rest period for all groups, and no effects were observed for salivary alpha amylase. Conclusions Based on this result, the sets and reps can be modified to change the recovery time. This effect is very useful to improve the performance in relationship to different fitness levels.

(Table 1) Oxygen and carbon isotopic values of benthic foraminifera from the Upper Maastrichtian interval of various DSDP and ODP sites

Stable isotopic data from benthic foraminifera indicate the occurrence of at least three deepwater masses in the late Maastrichtian ocean. Given mean oceanic d18Ow of -1.0 per mil, the temperature of the coolest intermediate-depth waters was 5°-7°C, that of the deepest waters was 10°C, and that of the warmest intermediate waters was 13°-15°C. The cool intermediate-depth water mass probably originated in the high-latitude Southern Ocean. The deepest waters originated at least partly in the northern Atlantic. The source region for the warmest intermediate-depth water mass is unknown. Although much of the late Maastrichtian deep water was probably preconditioned for winter sinking by low- or middle-latitude evaporation, no more than ~11% of late Maastrichtian deep water could have been directly actuated by low-latitude sea surface evaporation. At least in the southern Atlantic and Indian Oceans, heat transport by upwelling of deep water was not the primary cause of mild sea surface and coastal temperatures.