Full Grain Research Articles

High-resolution field measurements and numerical modelling of intra-wave sediment suspension on plane beds under shoaling waves

Intra-wave sediment suspension is examined using high-resolution field measurements and numerical hydrodynamic and sediment models within 120 mm of a plane seabed under natural asymmetric waves. The detailed measurements of suspended sediment concentration (at 5 mm vertical resolution and at 4 Hz) showed two or three entrainment bursts around peak flow under the wave crest and another at flow reversal during the decelerating phase. At flow reversal, the mixing length was found to be approximately double the value attained at peak flow under the crest. To examine the cause of multiple suspension peaks and increased diffusion at flow reversal, a numerical “side-view” hydrodynamic model was developed to reproduce near-bed wave-induced orbital currents. Predicted currents at the bed and above the wave boundary layer were oppositely directed around flow reversal and this effect became more pronounced with increasing wave asymmetry. When the predicted orbital currents and an enhanced eddy diffusivity during periods of oppositely directed flows were applied in a Lagrangian numerical sediment transport model, unprecedented and extremely close predictions of the measured instantaneous concentrations were obtained. The numerical models were simplified to incorporate only the essential parameters and, by simulating at short time scales, empirical time-averaged parameterisations were not required. Key factors in the sediment model were fall velocities of the full grain size distribution, diffusion, separation of entrainment from settlement, and non-constant, but vertically uniform, eddy diffusivity. Over the plane bed, sediment convection by wave orbital vertical currents was found to have no significant influence on the results.

Microstructural development during final-stage sintering of nanostructured zirconia based ceramics

The microstructural evolution of nanostructured zirconia based ceramics during pressureless final-stage sintering in vacuum was followed using X-ray diffraction, high resolution scanning electron microscopy and small-angle neutron scattering (SANS). The ultra-fine zirconia and yttria powders were synthesized by the inert gas condensation technique, the ultra-fine alumina by chemical vapor condensation. Powder compacts of ZrO 2 and dispersion mixed 5 mol% Y 2O 3 partially stabilized ZrO 2 and ZrO 2+14 wt.% Al 2O 3 were sintered at temperatures between 1000 and 1200°C for 2 h. Densification and concurrent grain growth as a function of temperature revealed a significant suppression of grain growth in the zirconia/alumina composite. Due to a homogeneous distribution of the alumina second phase in the zirconia matrix nearly full density and grain sizes <40 nm were achieved. Changes in the microstructure of monoclinic zirconia sintered at T>1050°C were detected by SANS and could be attributed to the detrimental effects of the monoclinic to tetragonal martensitic phase transformation. The log-normal pore size distributions were also evaluated for the ceramics.

Structural characterization of grain pattern diversity in parametric space

Grain patterns are characterized by size and shape diversity as reflected by variations in the values of structural parameters ascribed to them. Analysis of the population of grains calls for a global analysis of all the pertinent structural parameters taken together. In this study, algorithms were developed for advanced grain image analysis, unbiased grain size-side measurement and full grain pattern recognition. The correlations of these normalized structural parameters were studied for each topological class and geometrical group, for the grain patterns formed under different nucleation-growth conditions. Relationships between the structural parameters and the grain spatial coordinates are given. This provides a useful approach to investigate the structural inhomogeneity in grain patterns. The results show strong interdependence between the topology, geometry and physical dynamics of the spherulitic grain size-shape arrangement in semi-crystalline polymeric films.

Evapotranspiration and Yield of Corn Grown on Three High Plains Soils

AbstractSoil properties that vary within a production area present management challenges to producers when water supplies are limited. We conducted three experiments to determine the influence of soil type and different water management levels on corn (Zea mays L.) yield, evapotranspiration (ET), and water use efficiency. Short‐season corn was grown at low population density in Iysimeters containing monolithic soil cores of Pullman (fine, mixed, superactive, thermic Torrertic Paleustoll), Ulysses (fine‐silty, mixed, superactive, mesic Aridic Haplustoll), and Amarillo (fine‐loamy, mixed, thermic Aridic Paleustalf) soils, at a rain shelter facility in Bushland, TX. Dryland conditions were simulated in 1994 and 1995, with the soils receiving irrigations totaling either 50 or 150 mm in 1994 and either 120 or 200 mm in 1995. In 1996, water management levels were expanded, with the soils receiving weekly irrigation equivalent to 20, 50, 80, and 110% of measured ET. Grain yields for the 3 yr ranged from 389 to 804 g m−2 for the Pullman soil, 559 to 899 g m−2 for the Ulysses soil, and 438 to 736 g m−2 for the Amarillo soil. Low grain yields from corn in the Pullman soil were due to limited water extraction from the lower soil profile. Even under full irrigation (110%), grain yield and leaf area were lower for corn in the Amarillo soil than with the two other soils, possibly due to limited water availability. Soil type effects on corn water use and yield may require different water management strategies for optimum water use efficiency.

Mondrian, Hegel, Boogie

interior. By 1940 he was thoroughly uprooted, first by a move within Paris in 1936, forced by urban renewal, then by his emigration via London to New York. He used to stroll proudly through notorious double traffic circle at place de l'Opera, a latter-day flaineur. In New York he had trouble crossing streets, missed sight of Paris prostitutes, and patronized a cheap French restaurant for its red-and-white tablecloths.4 Of course, Mondrian would have dismissed any feelings of nostalgia or dislo3. Holtzman played records on Mondrian's first or second night in New York. See Holtzman, Piet Mondrian: The Man and His Work, NANL, p. 2, and Virginia Pitts Rembert, America, and American Painting (Ph.D. diss., Columbia University, 1970), p. 33. Mondrian owned five boogie-woogie albums and frequented, among other clubs and dance halls, Caf6 Society Downtown, which showcased music. 4. Theo van Doesburg to J. J. P. Oud, February 4, 1920, quoted in NANL, p. 124: One could cross Place de l'Opera only with greatest caution, but Mondrian did it as calmly as if he were in his atelier. The information about New York is from Von Wiegand's journals. This content downloaded from 207.46.13.184 on Sun, 10 Apr 2016 06:09:12 UTC All use subject to http://about.jstor.org/terms Mondrian, Hegel, Boogie 121 cation as individual, tragic, and romantic, not to mention embarrassing to a good internationalist. His anxieties found expression in a more allowable concern: namely, that exile might break flow of time, and thus of painting. If New York works have a subject, it is shape of time or history as such. Admittedly, this history, like Hegel's, is abstract, lacking full grain of ordinary reality. Yet Mondrian's pictures bear traces not only of his physical body, but of that other corpus, work itself, which he felt bound to protect, transport, and shape into something that would register his experience. To read these traces, must consider Mondrian's thinking about time and change, in history and in painting. Hegel and Continuity Mondrian's great subject, in some sense his medium, was time. This is opposite of accepted view, that Mondrian was a Platonic idealist who valued not becoming, and wanted his work experienced all at once, in a transcendent instant. As a recent critic writes, Mondrian's color planes all need to be seen at once for their meditative harmony to register with full force.... Mondrian's work seems to sit lotuslike in harmonious austerity of his apartment. ... Mondrian's art is meant to transcend material world.5 That Greenbergian account would do well for many an abstract painter, but Mondrian's idealism was by no means purely Platonic. He subscribed to Hegel's critique of Plato, which he knew through popular work of Dutch Hegelian G. J. P.J. Bolland, if not also directly. Hegel qualified Plato's celebration of eternal Forms with a Heraclitan emphasis on change and flux.6 He insisted that time could be transcended only by working through it, and likewise, that ideal could only be approached along path of material embodiment. Spirit necessarily appears in wrote Hegel, so long as it has not grasped its Notion, has not annulled Time.7 Beyond time is True Reality, Mondrian paraphrased, but (significantly switching emphasis) we are living in time. We have to reckon with its Changing.8 5. Simon Schama, Dangerous Curves, The New Yorker, November 4, 1996. 6. Hegel's Science of Logic famously opens by contrasting pure of Parmenides (crucial for Plato's theory of Forms) with of deep-thinking Heraclitus, and proceeds to derive becoming from dialectic of being and nothing (G. W. F. Hegel, Science of Logic, trans. A. V. Miller [Atlantic Highlands, N.J.: Humanities Press, 1969], p. 83). Significantly, it was quality of in distinction to that Theo Van Doesburg insisted on in his first review of Mondrian's work in 1915. See PM, p. 170. Of course, Hegel can figure in many ways. Annette Michelson argues that what De Stijl artists heard in Hegel was the stilled voice of Becoming in repose of Absolute Spirit, in place where Dialectic comes to rest, that point beyond Time, at end of History, and that Mondrian more than Van Doesburg hoped to instantiate movement of Dialectic toward Ideality through progressive elimination of particular determination (De Stijl, Its Other Face: Abstraction and Cacaphony, or What Was Matter with Hegel? October 22 [Fall 1982], pp. 8, 11). Without at all denying importance to Mondrian of an idealist teleology, present essay emphasizes material, temporal, half of dialectic in Mondrian, as in Hegel, and difficulty and resistance that accumulate as historical endpoint of dialectic is felt to approach. 7. G. W. F. Hegel, Phenomenology of Spirit, trans. A. V. Miller (Oxford: Oxford University Press, 1977), p. 487. 8. Mondrian [Life, Time, Evolution, c. 1938-44], NANL, p. 361. This content downloaded from 207.46.13.184 on Sun, 10 Apr 2016 06:09:12 UTC All use subject to http://about.jstor.org/terms

Cytological Analysis in the Microsporogenesis of Ramie, Boehmeria nivea Gaud. (Urticaceae) and the Effect of Colchicine on the Chiasma Frequency.

Cytological analysis were done in microsporogenesis of Boehmeria nivea (ramie) var.'Miyasaki' which was treated with 0.1+0.1% colchicine solution in seed and seedling phases. Control plants without any treatment in seed and seedling phases were also analyzed. Meiosis was normal except for the occurrence of cytomixis in both control and treated plants. Colchicine did not cause cytomixis occurrence. It was supposed that this phenomenon would be associated with crop culture condition. Although colchicine treatment was not effective to induce chromosome duplication, it may have caused reduction in average of chiasma number per cell and also reduction in pollen grain germination. Two types of pollen with different cytoplasm content were noticed in treated and in control plants. One type had full cytoplasm and other type had less cytoplasm which in many cases was wrinckled. It was supposed that this latter pollen type was consequence of cytomixis. Only full pollen grains germinated in agar media. Test for apomixis in 'Miyasaki' variety showed it did not form apomictic fruits, either in control or in 0.1+0.1% treated plants.

Expression of lipoxygenase isoenzymes in developing barley grains

Expression of lipoxygenase was studied in whole developing barley grains from 5 days after flowering (DAF) to full maturity. Lipoxygenase showed two distinct peaks of activity. The first peak of activity occurred in the early stages of grain development, from 5 until 20 DAF, whereas the second peak occurred at the later stages, from 30 DAF to the full grain maturity. The temporal expression of both LOX-1 and LOX-2 was studied at the protein and mRNA levels using specific probes and by analyzing the hydroperoxides formed during grain development. These experiments showed that a LOX-2-type isoform is present at early stages of development, located in the envelopes of the grain, whereas a LOX-1 isoform accumulates in the embryo in the late stages of development. Additionally, the spatial and temporal pattern of hydroperoxide-metabolizing activity was shown to be comparable to that of lipoxygenase activity. We demonstrate that two lipoxygenases appear during barley grain development, differing in their spatial and temporal expression. These two enzymatic pathways give rise to a distinct set of end-products indicating that the lipoxygenases may play different physiological functions during grain development.

Relationship Among the Phytic Acid and Protein Content During Maize Grain Maturation

AbstractThe accumulation of phytic acid with relation to the deposition of the protein component in grain during maturation of three maize varieties grown under the same topographical and agrotechnical conditions over 2 crop years was investigated.Phytic acid was determined by the spectrophotometric method of Mohamed et al. (1986).Phytic acid content increased significantly (P = 0.05) up until the late stage of dough grain maturity. Afterwards, until full grain maturity, no significant changes of phytic acid content have been obtained. At the same time, changes of phytic acid content expressed on a dry matter basis correlate highly significantly (P = 0.001) and negatively with total nitrogen in both vegetation years (r = ‐0.848 and r = ‐0.845) and alpha‐aminonitrogen content (r=‐0.799 and r = ‐0.792), but highly significantly (P = 0.001) and positively with prolamine content (r = 0.823 and 0.654). Grain maturation under conditions of increased moisture and lower temperature resulted in lower phytic acid level.

309 Is 5-HT2 receptor involved in the nociceptive and hyperalgesic mechanisms of serotonin?

In order to quantify the effects, at different stages during grain filling, of alternating day/night high temperature regimes on sunflower grain yield and quality, heads were exposed to high temperatures during 7 or 6 days starting either 10–12 days after anthesis (daa, HT1), 18 daa (HT2) or 24 daa (HT3). Also, heads were exposed to high temperatures for periods of 2, 4 or 6 days in each of HT1 and HT2. Temperatures covered a range of mean daily grain temperature of 20–40 °C and peak grain temperatures (i.e., those prevailing during the central 5 h of the daylight period) of 26–45 °C. High temperature stress for periods of 4 days or longer produced significant (p < 0.05) reductions in grain yield and grain quality. Early (HT1) exposure to stress reduced yield by 6%/°C above a mean grain temperature threshold of 29 °C; later (HT2 + HT3) exposures reduced yield by 4%/°C above a threshold of 33 °C. These reductions in yield were attributable to reductions in unit grain weight at all positions (periphery, intermediate, central) on the head, and an increase in the proportion of very small (10–30 mg) grains, termed half-full (HF) grains in this paper. In both full and HF grains, stress in either HT1 or HT2 reduced final pericarp weight, associated with fewer number of cell layers and thinner cell walls in the schlerenchyma. High temperatures reduced both the rate and duration of oil deposition in the grain, with the greatest effects being found with early (HT1) exposures. The unsaturation (oleic acid/linoleic acid) ratio of oil from mature grain was altered only when exposure to heat stress overlapped with the cessation of deposition of storage lipids. The effects of duration and intensity of heat stress on relative (to control) grain yield and oil content could be reasonably summarized using a linear response to cumulative hourly heat load calculated with a base temperature of 30 °C. We conclude that: (i) 4 days of alternating day/night temperatures resulting in mean daily grain temperatures of >30 °C can reduce sunflower grain yield and quality; (ii) the magnitude of these effects is strongly dependent on the timing of exposure and their nature on the grain growth processes active at the time of stress; and (iii) an hourly heat load (base = 30 °C) provides a useful integrative estimator of the effects of exposure to heat stress on grain yield and oil content for a given phase of grain filling.

Effect of free-air CO 2 enrichment (FACE) on forage quality of wheat

Wheat ( Triticum aestivum L., cultivar ‘Yecora rojo’) was grown in ambient (370 μmol mol −1) or enriched (550 μmol mol −1) concentrations of CO 2 in the free-air CO 2 enrichment (FACE) project, and components were analyzed for in vitro digestibility, fiber constituents, and crude protein. Four replicated plots of each CO 2 treatment were split for irrigation: ‘wet’ regions received 60 cm of water and ‘dry’ regions received 30 cm of water through underground tubes. Enriched CO 2 concentrations had no effect on in vitro digestion of intact sections of young (26–32-day-old plants) leaf blades except at 24–27 h incubation, at which time enriched leaves were lower in digestibility than control ones. Enriched CO 2 concentrations increased the content of acid detergent fiber (ADF) and cellulose of young wet leaves. Sections of main shoots at 26 days tended to have increased digestibility with elevated CO 2 levels. Enriched CO 2 concentrations did not alter the digestibility of flag leaves from 105-day-old plants or of flag leaves, uppermost stems, and sheaths from plants at full grain maturity. Enriched CO 2 levels reduced the acid detergent lignin (ADL) and tended to reduce the protein of leaves from 105-day-old plants. For mature leaf blades, neutral detergent fiber, ADF, and cellulose were, or tended to be, higher while protein content tended to be lower in elevated CO 2-grown plants; for both CO 2 treatments, ‘dry’ leaves were higher in digestibility and lower in ADL than ‘wet’ samples. Mature stems plus sheaths had lower protein contents in plants grown in elevated CO 2. Results indicated that enriched CO 2 concentrations to 550 μmol mol −1 did not substantially alter wheat in vitro digestibility, regardless of irrigation treatment. Elevated CO 2 altered fiber components and protein, but these were not consistent among parts and harvests.

The COMET experiment

Abstract— The COMET program is a program for the collection of micron to submicron interplanetary dust particles in low Earth orbits. Since collection takes place as the Earth crosses a given meteor stream, the particles are mainly of cometary origin. The grain remnants, located at their impact positions on high purity metallic collectors, are analysed in the laboratory for chemical and isotopical identification. The COMET‐1 experiment took place in 1985 October, during encounter with the Draconid meteor stream, related to the Giacobini‐Zinner comet. The fluence of extraterrestrial grains that had impacted our detectors was ∼10x higher than the value of the mean meteroid fluence at ∼1AU, which suggests that most of the grains originated from the Giacobini‐Zinner comet. One of the most important results of their chemical analysis was that ∼90% of them are enriched in low Z elements (C and O have undoubedly been identified). They could contain a CHON phase similar to that observed in the close environment of Halley's nucleus. The first imagery of the grain remnants by field emission scanning electron microscopy suggests that they are very low density aggregates still present at the impacting positions which, in most cases, are very different from the impact craters observed for the same mean relative velocity for full grains of the same size. These results show that the COMET program has constituted an important step towards the analysis of cometary material and the understanding of the evolution of the early Solar System.

Irrigated spring wheat and timing and amount of nitrogen fertilizer. I. Grain yield and protein content

To improve N-use efficiency in wheat ( Triticum aestivum L.), this study determined the latest stage of development at which supplemental N fertilizer would elicit a full grain yield response. Three experiments were carried out in 1986 with early-June-sown irrigated semidwarf spring wheats in a low fertility field at Griffith in New South Wales (34°S). N was supplied as NH 4NO 3 top dressings and crop management was otherwise optimal. The grain yield response to N given at seeding was very high (in the main experiment the initial slope was 38 kg grain/kg N, with 180 kg N/ha increasing yield from 1812 kg/ha to 7113 kg/ha). Single N dressings given in this and an adjacent second experiment indicated no significant decrease in yield response until dressings were delayed beyond the onset of stem elongation. There was no evidence of synergism between early and late split N dressings. The apparent N recovery in the crop at maturity ranged from 44–77% (mean 63%) and did not decline strongly until all N was given after stem elongation began. 15N recovery in crop from labelled fertilizer applied to microplots ranged from 40 to 56% and increased slightly with later N dressings, while losses decreased. With delay of single N dressings, grain protein content only increased with dressings after the onset of stem elongation. Excluding those treatments where all N was given after this stage, protein responses were quantitatively related inversely to grain yield responses ( r 2=0.49), with negative responses accompanying the large yield responses (>35 kg grain/kgN) generated by initial increments of N. Examination in a third experiment of possible predictors of the optimum amount of supplemental N to be given at the onset of stem elongation suggest that stem base NO 3-N concentration and culm number m −2 could serve this role.

On the interaction between dust and gas in late-type stellar atmospheres and winds

An assumption inherent to most models of dust-driven winds from cool, evolved stars is that the radiative and collisional drag forces acting on an individual dust grain are in balance throughout the flow. We have checked the validity of this supposition of 'complete momentum coupling' by comparing the grain motion obtained from such a model with that derived from solution of the full grain equation of motion. For physical conditions typical of the circumstellar envelopes of oxygen-rich red giants, we find that silicate grains with initial radii smaller than about 5 x 10 exp -6 cm decouple from the ambient gas near the base of the outflow. The implications of these results for models of dust-driven mass loss from late-type giants and supergiants are discussed.

Experiments with upland rice in southern Belize: fertilizer application, weed control, plant spacing, sowing rate and variety

SUMMARYAgronomic research was carried out on upland rice in Toledo District, Belize, in 1979–86, with the objective of improving returns from the traditional system of shifting cultivation and of examining the potential for reducing the demand for new land by cropping for more than one season. The rice was grown in the wet season on land cleared from forest by slash and burn, using a traditional planting technique, placing seed in holes made with a pointed stick.In a series of fertilizer experiments, in which rice was grown for up to 7 consecutive years, urea and triple superphosphate both increased grain yield, whereas muriate of potash had no effect. Mean yield in the fifth year was 85 % of that in the first. Urea and triple superphosphate both increased the number of full grains/panicle.A slash and mulch weed control treatment before sowing resulted in low yields of grain in the third year; yield after the use of propanil and 2,4-D (after sowing) was, on average, 77% of the yield after hand weeding; omitting weed control after sowing led to very low yields, particularly in the second and third years.In the varieties Bluebonnet and C22, grain yield was increased by reducing the distance between stations, particularly where 6, rather than 15, seeds were sown per station. Reducing the distance between stations increased the leaf area index during crop development and the number of panicles/m2, which more than counterbalanced reductions in the number and area of leaf blades per plant, the number of panicles per plant and the number of full grains per panicle. However, the yield/kg of seed sown and per hour spent planting was greatest at the widest spacing. C22 produced more panicles per plant and a greater weight of grain per plant and per hectare than Bluebonnet.It was concluded that returns from the traditional system can be improved and the demand for new land reduced.

Electron Microscopic Study of Domains in Relaxor Ferroelectrics

AbstractThe ferroelectric and antiferroelectric displacements in perovskite-based ceramics give rise to a wide range of domain structures. This paper reports on transmission electron microscopy observations as a function of temperature of such structures in PLZT and PLSnZT. In the PLZT system superposition of the diffraction patterns from modulated domains of low symmetry give rise to patterns with an apparent high symmetry. The ½(hkl)-type reflections become more intense with decreasing temperature and split into diffuse rods at high temperature. In the PLSnZT system a hierarchy of domain structures is observed with length scales ranging from unit cell dimensions to the full grain size. A temperature dependent long-period modulation along the &lt; 110 &gt; directions is observed.

Correlation of shearing properties with the structure of garment leathers

Shearing property is of fundamental importance in influencing the complex deformations of a garment leather during use. The properties such as stretch, shape retention etc., are closely related to the shearing behaviour of garment leather. Although, textile fabrics have been investigated extensively for their shearing properties(1-3), the studies on leather have been limited. It is logical to expect the three-dimensional structure of leather and the intrinsic properties of collagenous fibre would be markedly different from those of other textile fabrics. The shearing property of a fabric can be expected to be influenced by its weave and matrix structure. An attempt has now been made to correlate the ultra and micro structural details of a garment leather with its shearing properties.A simple instrument has now been developed to assess the shearing behaviour of a soft fabric like garment leather. The shear test on garment leather involves the radial deformation of a sample piece by small degrees and measurement of the resultant shear stress and strain levels. Full chrome grain garment and suede garment leathers obtained from sheep skins were used for measurement of shearing properties.

Static and Thermal Loads in Full Size Grain Bins Predicted by Vectorized FEM on Supercomputer

ABSTRACT <emph>T</emph>he second generation finite element model (FEM) was vectorized on CYBER 205 supercomputer to predict static and thermally induced bin wall pressures in full size grain bins filled with wheat. The load response of three steel bins—3 m, 6.4 m and 9 m in diameter, respectively, and 9 m in height were studied using the FEM. The three, height to diameter ratios encompassed shallow and deep bin regimes. The FEM predicted static pressures compared favorably with the Janssen static pressure theory for all three bins. The mean square error between Janssen and FEM was in the 0.7 to 1.6 kPa range. The FEM predictions indicated that thermal lateral bin wall pressure increased with grain depth. Thermal lateral overpressures averaged over grain depth were 7.4%, 7.0% and 7.4% of static pressures at 10 C, 14.7%, 14.0% and 14.3% at 20 C and 21.9%, 21.1% and 21.2% at 30 C temperature drop for 3 m, 6.4 m and 9 m bins, respectively.

Meiotic behaviour of extra chromosomes in fertility restored Polima CMS Brassica napus plants

Crosses were made between Brassica napus (2n = 38) with the 'Polima' cytoplasmic male sterile system and variety 'Zem' of B. juncea. Fertility was partially restored in backcross progeny with an extra chromosome (2n = 39) that was believed to be a member of the B genome of B. juncea. Among more than 40 self-pollinated offspring plants studied, fertility restoration was transmitted only through those plants with two extra chromosomes (2n = 40). Anthers of these plants were either full or shriveled with small swollen protrusions. Full and round pollen grains were found in full anthers and in the swollen portion of shriveled anthers. These pollen grains were stained darkly with I2-KI solution and full seed set was obtained from bagged flowers. Meiotic studies in plants with 2n = 40 showed 18 bivalents + 1 quadrivalent at diakinesis in most of the pollen mother cells analyzed. The chromosomes segregated equally at anaphase I and behaved normally at other meiotic stages. The presence of a single quadrivalent in the backcross progeny was highly consistent and occurred in very high frequencies. It is believed that the extra chromosomes belong to the B genome of B. juncea and take part in the quadrivalent formation.Key words: Brassica napus, cytoplasmic male sterility, aneuploidy, Polima, Brassica juncea, rapeseed cytogenetics.

Ejecta pulsing of subscale solid propellant rocket motors

This paper presents results obtained in a program designed to develop guidelines for pulsing solid propellant rocket motors to determine their susceptibility to finite amplitude disturbances. A series of motor firings was conducted in which sphetes of different sizes and materials were ejected through the nozzle to simulate inf light partial nozzle blockage due to igniter, propellant or other combustion chamber material fragments. Simple laboratory scale solld rocket motors with full and partial length grains were utilized. All of the motors tested were triggered into sustained nonlinear instability. A simple analysis was developed to calculate the velocity of the ejecta and pulse duration. Gaod ogreement between predicted and measured pulse durations was obtained. Two methods were developed for predicting initial ejecta induced pulse amplitudes: a simple model based on linear wave propagation theory and the assumption of quaslsteady nozzle behavior, and a numerical model which utillzes the quasi-steady nozzle assumption to provide a nozzle entrance boundary condition to a comprehensive combustion chamber nonlinear instability analysis. Comparisons of theoretical predictions with experimental data for both pulse amplitude and the motor response to pulsing are presented. Tht nonlinear instability analysis was found to be capable of predicting the complete range of nonlinear behavior observed in motor response to ejecta pulsing. Good agreement between measured and predicted initi pulse (amplitude and harmonic content), waveform evo ution, growth and decay rates, and DC shift was obtained. p'

Compensation in grain yield components in a panicle of rainfed sorghum

SUMMARYIn a field experiment with rainfed grown sorghum hybrid CSH‐6, various proportions of spikelets from the apex, base or random regions of the panicles were removed at the time of anthesis and the yield compensation in grain number and grain size within a panicle was investigated. The distribution of grain number and grain yield in a control panicle from apex to base was parabolic while grain size showed a progressive linear decrease. Full grain yield compensation occurred due to an increase in grain number and size when the panicles lost up to 20% of their portions at the base or at random. No grain number compensation was, however, recorded at the apical region. Irrespective of the number of spikelets retained, the size of grains in the upper part of the panicle was always larger than those in the lower part.The grain number compensation, which occurred when spikelets were removed at the time of anthesis and the decreasing grain size from apex to base of the panicle would suggest hormonal involvement in the determination of potential grain number and size.