Rate Of Grain Research Articles

Design of Longitudinal Axial Flow Threshing and Separating Device of Maize Grain Combine Harvester

Harvesting grain directly has been the development trend of modern maize combine harvester. To satisfy the demand of harvesting grain straightly type maize combine harvester for large feeding rate, low damage rate, high threshing rate, the longitudinal axial flow threshing and separating device was designed. It could also increase the separating rate of grain and miscellaneous, and reduce the burden of cleaning device. Threshing gap was adjustable in the range of 30 to 60mm, which reduced the incidence of jam faults effectively in the threshing process. Spiral blade on feeder, threshing rasp-bar and separating nail were replaceable, which improved the efficiency for threshing and separating.

Kinetic study of marine and lacustrine shale grains using Rock-Eval pyrolysis: Implications to hydrocarbon generation, retention and expulsion

The kinetic parameters of marine and lacustrine shale grains (4 mm) were retrieved by using Rock-Eval pyrolysis in comparison with finely ground powder (<0.178 mm) and kerogen of same samples. Results of grains show remarkable differences from powder and kerogen. Grains of Pingliang marine shale exhibit a relatively broader distribution of activation energies than powder and kerogen while grains of Yanchang lacustrine shale show higher dominant activation energies than powder and kerogen. At laboratory heating rates (5–25 °C/min), the corresponding temperatures to the maximum hydrocarbon generating rate of grains are 3–8 °C higher than powder and kerogen for marine shale and 6–8 °C higher for lacustrine shale, respectively. Extrapolated to geological heating rate (3 °C/my), the corresponding maturity and geological temperature to the maximum hydrocarbon expulsion rate of grains lags powder 0.02 Ro% and 3 °C, as well as 0.05 Ro% and 6 °C for marine shale and lacustrine shale, respectively. After the peak of hydrocarbon generation (Ro = 1%), the retention percentage for grain and powder of marine shale reach 7.33% and 0.09% while those for lacustrine shale reach 16.50% and 10.85%, respectively. These results suggest grains enjoy higher expulsion threshold and higher retention ability. The results suggest that Yanchang lacustrine shale exhibits stronger retention ability and weaker expulsion ability than Pingliang marine shale. The results presented in this study show that grain-based pyrolysis provides a novel method for evaluating the residual oil and gases for shale, which can study the hydrocarbon generation, expulsion and retention comprehensively.

Interaksi Genetik x Lingkungan dan Variabilitas Genetik Galur Gandum Introduksi (Triticum aestivum L.) di Agroekosistem Tropika

&lt;p&gt;The&lt;br /&gt;focus of wheat research in Indonesia is to obtained new&lt;br /&gt;potential wheat lines that are adapted to low-mid elevation&lt;br /&gt;and heat tolerant. This study was aimed to obtain&lt;br /&gt;information on the effect of interaction of season x line x&lt;br /&gt;location and genetic variability of wheat lines in tropical&lt;br /&gt;agroecosystem. This study was conducted at the Seameo-&lt;br /&gt;Biotrop (&amp;lt;400 masl) and Indonesian Ornamental Crops&lt;br /&gt;Research Institute-Cipanas (&amp;gt;1,000 masl) experimental field&lt;br /&gt;for two seasons. The results showed that there was an effect&lt;br /&gt;of interaction of season x line x location on plant height,&lt;br /&gt;days to flowering, number of spikelet and floret, seed/head&lt;br /&gt;weight, rate of grain filling, yield, flag leaf width, stomata&lt;br /&gt;density, chlorophyll b, and leaf greenness. Meanwhile&lt;br /&gt;several characters were only influenced by the interaction of&lt;br /&gt;line x location, they were yield component characters, ie.&lt;br /&gt;empty floret percentage, number of seed/ head, 1,000 seed&lt;br /&gt;weight, number of head/m2 and seed/plant weight. Seven&lt;br /&gt;characters were not influenced by interaction of neither&lt;br /&gt;season x line x environment nor line x location, they were&lt;br /&gt;number of productive tillers, head length, number of&lt;br /&gt;seed/head, chlorophyll a, ratio of chlorophyll a/b, total&lt;br /&gt;chlorophyll, and leaf thickness. The characters that have&lt;br /&gt;high heritability and wide genetic variability for the two&lt;br /&gt;analysis models were the number of spikelet.&lt;/p&gt;

Identification and gene mapping of a grain-filling mutant &amp;lt;italic&amp;gt;gef1&amp;lt;/italic&amp;gt; in rice

Grain filling is an extremely important process in rice growth and development. This process which involves complex genetic regulatory networks and environmental interaction, is directly related to the formation of rice yield and quality. A stable inherited mutant with grain extended filling ( gef1 ) was identified from an EMS mutagenized population of Yixiang 1B. The investigation of agronomic traits, measurement of physiological and biochemical characteristics, histology observation, gene expression analysis and gene mapping were performed in this study. Compared with the wild type plants, the grain filling rate of gef1 was significantly lower than that of Yixiang 1B, resulting in the grain filling time of gef1 was about 30 days delay. Meanwhile, the 1000-grain weight of gef1 became bigger and seed setting rate decreased by 22%. During the development of caryopsis, we found that the soluble sugar content in wild type showed a single peak curve, and the content maintained at a low level throughout the grain filling stage. However, the soluble sugar content of the gef1 was significantly higher than that of the wild type, and showing a bimodal curve. It revealed that the transportation and distribution of photosynthate, and starch synthesis were inefficiency in gef1 . In addition, histocytological analysis showed that the number of big vascular bundles in the same transection parts of rachis, the first top internodes and the second top internodes were all decreased in gef1 , and indicated that the transport efficiency of photosynthate was one of the limiting factors in the rate of grain filling. The scanning electron microscope showed that the glume of gef1 had smooth surface and slender cells. Scanning of grain transection showed that gef1 had spherical amyloplasts and arranged loosely, but the wild type had unregular polygon amyloplasts and packed closely. These results suggested that the changes of grain size associated with the cell number and shape of glume, and gef1 had impact on rice quality. Additionally, by analyzing the expression of the glycometabolism-related genes in developing caryopsis, we found that all of them were keeping at a low level in gef1 compared with the wild type. By analyzing the three crosses gef1 /Yixiang 1B, gef1 /02428 and gef1 /Kitaake, we found that the F1 plants of these three crosses were all normal and indicated that the mutant trait was controlled by a recessive gene. The ratio of normal plants to mutant plants in the three F2 populations was 3:1 and indicating that the mutant trait was controlled by a single recessive nuclear gene. gef1 was preliminarily mapped on the short arm of rice chromosome 3, and was narrowed to a 198 kb region between InDel3-1 and InDel3-2. This region has 21 open reading frames and there was no homologous gene had been reported within it, and the further identification work of candidate genes is ongoing.

Preferential Nucleation during Polymorphic Transformations.

Polymorphism is the ability of a solid material to exist in more than one phase or crystal structure. Polymorphism may occur in metals, alloys, ceramics, minerals, polymers, and pharmaceutical substances. Unresolved are the conditions for preferential nucleation during polymorphic transformations in which structural relationships or special crystallographic orientation relationships (OR’s) form between the nucleus and surrounding matrix grains. We measured in-situ and simultaneously the nucleation rates of grains that have zero, one, two, three and four special OR’s with the surrounding parent grains. These experiments show a trend in which the activation energy for nucleation becomes smaller – and therefore nucleation more probable - with increasing number of special OR’s. These insights contribute to steering the processing of polymorphic materials with tailored properties, since preferential nucleation affects which crystal structure forms, the average grain size and texture of the material, and thereby - to a large extent - the final properties of the material.

Analyse Genotypique De La Contribution De La Matiere Assimilée Du Pedoncule Dans Le Remplissage Du Grain Chez Le Ble Dur (Triticum Durum D.E.S.F.)

In a part of study on morpho-physiological characterization in durum wheat; we were interested in quantifying the stem dry matter produced after anthesis and its contribution in the grain filling. When the climatic conditions are unfavorable ; the photosynthetic activity of the post-anthesis is reduced. The plant then uses the assimilates stored in the stem to increase its filling rate of grain. Thus, the behavior of four varieties of durum wheat is analyzed in the field using different parameters: (i) relative water content (RWC) of the flag leaf (ii) dry weight development of the grains (iii) peduncle assimilated dry matter contribution in the grain filling. The leaf water status, appreciated by measuring the RWC, is an indicator of the photosynthetic apparatus functioning. The measured values showed a significant difference between two agricultural companions. The results also showed a genotypic difference in the dry matter accumulation in the grains, mainly related to its filling speed. The accumulation of assimilates in the peduncle during the days following flowering, constitutes an advantage of reserves in dry matter before installation of water deficit. Indeed, it affects production by decreasing the photosynthetic activity. In conclusion, this experiment has highlighted two types of grain yield elaboration of cultivated wheat in the post-anthesis water deficit conditions.

Triple bag hermetic technology for controlling a bruchid (Spermophagus sp.) (Coleoptera, Chrysomelidae) in stored Hibiscus sabdariffa grain

We assessed the performance of hermetic triple layer Purdue Improved Crop Storage (PICS) bags for protecting Hibiscus sabdariffa grain against storage insects. The major storage pest in the grain was a bruchid, Spermophagus sp.. When we stored infested H. sabdariffa grain for six months in the woven polypropylene bags typically used by farmers, the Spermophagus population increased 33-fold over that initially present. The mean number of emergence holes per 100 seeds increased from 3.3 holes to 35.4 holes during this time period, while grain held for the same length of time in PICS bags experienced no increase in the numbers of holes. Grain weight loss in the woven control bags was 8.6% while no weight loss was observed in the PICS bags. Seed germination rates of grain held in woven bags for six months dropped significantly while germination of grain held in PICS bags did not change from the initial value. PICS bags can be used to safely store Hibiscus grain after harvest to protect against a major insect pest.

Criterion validity of the visual estimation method for determining patients' meal intake in a community hospital

The accuracy of the visual estimation method is unknown, even though it is commonly used in hospitals to measure the dietary intake of patients. We aimed to compare the difference in the validity of visual estimation according to the raters' job categories and tray divisions, and to demonstrate associations between meal characteristics and validity of visual estimation in a usual clinical setting in a community hospital. We collected patients' dietary intake data in usual clinical settings for each tray in 3 ways: visual estimation by nursing assistants, visual estimation by dietitians, and weighing by researchers (reference method). Dietitians estimated the dietary intake using 2 divisions, namely, whole tray and food items. Then we compared the weights and visual estimation data to evaluate the validity of the visual estimation method. Mean nutrient consumption of target trays was significantly different when using the visual estimation of target trays than when using the weighed method (visual estimation by nursing assistants [589±168kcal, 24.3±7.0g/tray, p<0.01], dietitians' whole trays [561±171kcal, 23.0±6.9g/tray, p<0.05], food items [562±171kcal/tray, p<0.05], and dietitians' food items [23.4±7.3g/tray, p=0.63]). Spearman's correlations for both methods were very high for energy (ρ=0.91-0.98, p<0.01) and protein intakes (ρ=0.88-0.96, p<0.01), respectively. The limits of agreement in the Bland-Altman plot for both dietary intake categories were-121kcal to 147kcal/tray and-6.4g to 7.0g/tray (nursing assistants, whole division),-122kcal-106kcal/tray and-6.7g to 5.5g/tray (dietitians, whole divisions), and-82kcal to 66kcal/tray and-4.3g to 3.9g/tray (dietitians, food items divisions). High intake rate of grains was significantly associated with decreased odds of a difference between two methods based on the nursing assistant's whole tray evaluation (odds ratio [OR]: 0.85; 95% confidence interval [CI]: 0.76-0.94) and the dietitians' whole tray (OR: 0.80; 95% CI: 0.72-0.89) and food items evaluations (OR: 0.64; 95% CI: 0.56-0.73), respectively. In addition, minced meals were also associated with a difference between two methods, for the nursing assistants' whole tray (OR: 3.53; 95% CI: 1.66-7.51) and dietitians' food items (OR: 2.92; 95% CI: 1.37-6.22). Visual estimation by nursing assistants and dietitians correlated highly with the weighing method although the limits of agreement were wide. Nursing assistants and dietitians should pay attention to low consumption and modified texture meals when evaluating dietary intake using the visual estimation method.

Nanoscale corrosion behavior of polycrystalline copper fine wires in dilute NaCl solution investigated by in-situ atomic force microscopy

In this study, nanoscale corrosion behavior of copper fine wires in dilute NaCl solution is studied by atomic force microscopy and electron backscatter diffraction. The dissolution rate of grains constituting the wires strongly depends on their crystallographic orientation. In pure water, the dissolution rate increases in the order of (111)<(001)<(110). Addition of Cl− dramatically increases the dissolution rate of the (111) surface to alter the order to (110)≈(001)≈(111) at 0.1mM. These results show that the crystallographic orientation dependence is significantly changed by a slight increase of Cl− concentration in dilute solution.

Effect of polyamines on the grain filling of wheat under drought stress

Drought inhibits wheat grain filling. Polyamines (PAs) are closely associated with plant resistance due to drought and grain filling of cereals. However, little is known about the effect of PAs on the grain filling of wheat under drought stress. This study investigated whether and how PAs are involved in regulating wheat grain filling under drought stress. Two wheat genotypes differing in drought resistance were used, and endogenous PA levels were measured during grain filling under different water treatments. Additionally, external PAs were used, and the variation of hormone levels in grains was measured during grain filling under drought stress. The results indicated that spermidine (Spd) and spermine (Spm) relieve the inhibition caused by drought stress, and putrescine (Put) has the opposite effect. The higher activities of S-adenosylmethionine decarboxylase and Spd synthase in grains promotes the synthetic route from Put to Spd and Spm and notably increases the free Spd and Spm concentrations in grains, which promotes grain filling and drought resistance in wheat. The effect of PA on the grain filling of wheat under drought stress was closely related to the endogenous ethylene (ETH), zeatin (Z) + zeatin riboside (ZR) and abscisic acid (ABA). Spd and Spm significantly increased the Z + ZR and ABA concentrations and decreased the ETH evolution rate in grains, which promoted wheat grain filling under drought. Put significantly increased the ETH evolution rate, which led to excessive ABA accumulation in grains, subsequently aggravating the inhibition of drought on wheat grain filling. This means that the interaction of hormones, rather than the action of a single hormone, was involved in the regulation of wheat grain filling under drought.

Response of different wheat genotypes to different sowing time in relation to GDD accumulation

An experiment on response of different wheat genotype to different sowing time in relation to GDD accumulation was carried out in Rabi season of 2010-11 at the research field of Wheat Research Unit, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola (M.S.). The treatments consisted of two sowing dates 45 MW, 48 MW and twenty wheat genotypes AKDW-4021, AKDW-2997-16, AKDW-4749,AKDW-4750, AKDW-4132-2, AKDW-3931-2, HD2189, HIDW-295, NIAW-34, AKAW-4627, LOK-1, MACS -1967, AKAW-3997, AKAW-4073, AKAW-4210-6, AKAW-4493, AKAW-4705, AKAW–4731, AKAW–4636 and AKAW-4739. The experiment was laid out in a Factorial Randomized Blocked Design with three replications. The soil was clayey with pH 7.89 containing N-206.00, P-15.86 and K303.43 kg ha value after harvest. The growth, yield attributes and yield observations showed significant increase when wheat crop was sown at 45 MW than 48 MW. Grain yield obtained was significantly higher at 45 MW sowing. Wheat crop sown at 48 MW required significantly lower cumulative growing degree days (GDD) and helio thermal units for completion of reproductive phase than 45 MW sown crop. Correlation studies reveal that correlation between straw yield and bright sunshine hours found to be significant showing the negative correlation and correlation between straw yield and relative humidity was observed to be significant showing the positive correlation. Sowing of wheat crop at 45meteorological week was recorded most economical under different date of sowing condition.Out of genotypes, AKAW4647 was superior over others in respect of tillers m, chlorophyll content plant, dry matter accumulation plant, number of grains earhead, yield per day per plant (g), rate of grain filling, grain yield (q ha), straw yield (q ha ) and test weight.

Elevated CO 2 Reduced Floret Death in Wheat Under Warmer Average Temperatures and Terminal Drought.

Elevated CO2 often increases grain yield in wheat by enhancing grain number per ear, which can result from an increase in the potential number of florets or a reduction in the death of developed florets. The hypotheses that elevated CO2 reduces floret death rather than increases floret development, and that grain size in a genotype with more grains per unit area is limited by the rate of grain filling, were tested in a pair of sister lines contrasting in tillering capacity (restricted- vs. free-tillering). The hypotheses were tested under elevated CO2, combined with +3°C above ambient temperature and terminal drought, using specialized field tunnel houses. Elevated CO2 increased net leaf photosynthetic rates and likely the availability of carbon assimilates, which significantly reduced the rates of floret death and increased the potential number of grains at anthesis in both sister lines by an average of 42%. The restricted-tillering line had faster grain-filling rates than the free-tillering line because the free-tillering line had more grains to fill. Furthermore, grain-filling rates were faster under elevated CO2 and +3°C above ambient. Terminal drought reduced grain yield in both lines by 19%. Elevated CO2 alone increased the potential number of grains, but a trade-off in yield components limited grain yield in the free-tillering line. This emphasizes the need for breeding cultivars with a greater potential number of florets, since this was not affected by the predicted future climate variables.

Effect of High Temperature on Leaf Physiological Changes as Chlorophyll composition and Photosynthesis Rate of Rice

등숙기 고온이 잎의 생리적 활력과 등숙에 미치는 영향을 알아보고자, 동안과 일품 두 품종을 등숙기에 고온 처리하여 등숙 형질을 분석하고, 잎의 광합성, 엽록소 함량 및 엽록소 a/b율 등을 알아보았다. 등숙기 고온(<TEX>$27{\pm}4^{\circ}C$</TEX>)처리에서 두 품종 모두 등숙률, 완전립률, 천립중이 감소하였으나 일품은 동안에 비해 모두 감소율이 컸다. 엽록소 함량은 등숙초기 고온에서 적온보다 두 품종 모두 증가하였으며, 등숙중기이후 엽록소감소양상은 온도처리에 따른 차이가 없었다. 엽록소 a/b율은 고온에서 감소하였다가 출수후 15일 이후 증가하였으며 적온에서는 출수 이후 지속적으로 증가하였다. 잎의 단백질농도 변화는 고온에서 등숙초기 약간 높은 경향이었으나 이후 처리 간 차이없이 등숙후기까지 지속적으로 감소하였다. 최대 광합성량은 유숙기인 출수 후 14일에 고온이 적온보다 높았고 출수후 7일과, 등숙후기(출수후 34일)에는 유의한 차이가 없었다. 잎의 유리당 함량은 고온이 적온보다 낮았다. 결론적으로 등숙기 고온은 잎의 생리적 활력을 적온보다 오히려 증가 시켜 엽록소함량과 광합성율이 증가하였으므로, 고온에 의한 이삭의 등숙저하는 이삭으로의 전류나 전분축적기작 과정의 문제가 더 클 것으로 생각된다. High temperature impairs rice grain yield and quality. To understand the effect of high temperature on leaf physiological activity and grain filling, two cultivars of rice that Dongan and Ilpum were exposed to high temperature during ripening stage. Grain filling rate, perfect grain ratio and grain weight of high temperature (<TEX>$27^{\circ}C{\pm}4^{\circ}C$</TEX>) treated both rice cultivars were decreased than those of control temperature (<TEX>$22^{\circ}C{\pm}4^{\circ}C$</TEX>) treated. The reduction rates of grain filling ratio, perfect grain ratio and grain weight of high temperature treated to control treated rice were higher in Ilpum than Dongan. Chlorophyll contents of rice leaves under high temperature at early ripening stage were higher than those of control temperature, but those were slowly decreased with no difference between temperature treatment since at mid ripening stage. Although chlorophyll a/b ratio under high temperature was decreased from heading to 15 days after heading, that was gradually increased since 15 days after heading. Protein concentrations of rice leaves for ripening stage was a similar pattern with chlorophyll changes. The rate of photosynthesis at 14 days after heading under high temperature was higher than those of control temperature, but there was no difference at those of 7 and 34 days after heading between two temperature treatment. Free sugars under high temperature treated leaves were lower than control temperature. Consequently, these results exhibit that high temperature accelerate leaf physiological activity as chlorophyll synthesis and photosynthesis rate unlike the deterioration of grain filling.

Realistic microstructure-based modelling of cyclic deformation and crack growth using crystal plasticity

Using crystal plasticity, finite element analyses were carried out to model cyclic deformation for a low solvus high refractory (LSHR) nickel superalloy at elevated temperature. The analyses were implemented using a representative volume element (RVE), consisting of realistic microstructure obtained from SEM images of the material. Monotonic, stress-relaxation and cyclic test data at 725°C were used to determine the model parameters from a fitting process and their sensitivity to RVE size and random grain orientation. In combination with extended finite element method (XFEM), the crystal plasticity model was further applied to predict surface crack growth, for which accumulated plastic strain was used as a fracture criterion. Again, realistic microstructure, taken from the cracking site on the surface of a plain fatigue specimen, was used to create the finite element model for crack growth analyses. The prediction was conducted for a pseudo-3D geometrical model, resembling the plane stress condition at specimen surface. The loading level at the cracking site was determined from a viscoplasticity finite element analysis of the fatigue specimen. The proposed model is capable of predicting the variation in growth rate in grains with different orientations.

Relevance of physiological efficiency in wheat grain quality and the prospects of improvement.

Released and pre-released bread wheat varieties evaluated in national wheat programme of India (503 genotypes) during 2005-14 under different environments were examined for the role of physiological parameters in grain quality. Genotypes with slow plant height growth but faster rate of grain filling enhanced protein content. Plants where growth in height and grain development was slow, grains were hard, provided proportionate vegetative growth phase is longer. Steady grain growth rate benefited gluten strength and gluten quality. Irrespective of total crop duration, longer reproductive phase was an effective indicator of higher flour recovery and test weight. Magnitude and significance of morphological attributes in grain quality was almost similar to that of physiological processes, therefore prospects of utilizing these field traits were examined to enhance grain properties. Early heading and longer grain filling was effective to increase test weight whereas delayed heading and shorter plant height enhanced protein content. Bold grains hampered grain hardness and delayed heading added more bran in the flour. Genotypes with poor grain bearing and quick grain ripening had lower sedimentation value. Instead of protein, it was wet gluten which expressed negative association with yield. To improvise gluten quality, extended reproductive phase but with less grain weight was helpful. Contribution of longer post-anthesis period was observed crucial in flour recovery. These useful simple field expressions can be deployed to uplift quality of wheat grains.

Influence of the capsular stigmatic ray populations on the agronomical economic traits and secondary metabolites in opium poppy (Papaver somniferum L.).

Poppy has been a plant of much importance and interest since time immemorial. In our 196 accessions, we observed, identified and selected distinct plants containing specific nature of capsules. These capsules if properly grouped according to the number of stigmatic rays – ranging from five to sixteen can become a useful morphological marker for farmers which will assist them instantaneously for selection of yield parameters related to their interests (seeds and or opiate alkaloids). In this investigation we explored the relation between notches in capsules with the agro-economical traits – seed yield and major opiate alkaloid content using plant breeding, bio-statistical and analytical tools and techniques for the first time in this crop. Briefly our study indicated that the rate of grain filling in poppy seeds is indirectly related and the intensity of colour and density of latex is directly related to the population of notches on their respective capsules.

An advanced level set approach to grain growth – Accounting for grain boundary anisotropy and finite triple junction mobility

The novelty of the proposed level-set approach to grain growth resides in the explicit consideration of structural interfacial elements of the microstructure. The extensions allow to consider anisotropic grain boundary energies and triple junction drag in polycrystalline materials. The simulated predictions were compared to analytical expressions for the growth rate of grains under the influence of a finite triple junction mobility with excellent agreement.

Influence of grain orientation on the incipient oxidation behavior of Haynes 230 at 900 °C

Ni-based superalloy Haynes 230 is used in many applications such as very high temperature reactor (VHTR) or solid oxide fuel cells (SOFCs) where it is exposed to high temperature service environment. In order to improve the resistance for high temperature oxidation, the effect of crystallographic orientation on the early stage oxidation was investigated. It was demonstrated that different oxide thicknesses are formed on grains having different orientations. Comparison of electron backscatter diffraction (EBSD) orientation maps before and after oxidation at 900°C indicates that grains near (111) orientation, especially with the deviation angle from <111> that is smaller than 20°, are more oxidation resistant than grains of other orientations. Correlation between the results of electron backscatter diffraction (EBSD) and atomic force microscopy (AFM) was used to compare the oxidation rate of grains having different crystallographic orientation. The oxidation rate was found to change with the crystallographic orientation as follows (111)<(110)<(100), also it was demonstrated that the oxidation rate changes are a nearly linear function of the angle of deviation from <111> direction. The morphology of surface oxide also depends on the orientation of grains.

Study on free fall surfaces in three-dimensional hopper flows

The flow rate of grains discharging from hoppers can be quantified by Beverloo’s law, where the assumption of the free fall arch (FFA) it is very useful in understanding the physical picture of this process but is difficult to be observed directly. Here simulations of 2,000,000 spheres discharging from three-dimensional flat-bottomed hopper with circular outlet were performed on multiple GPUs and the free fall surfaces were explored by statistical analysis. The free fall surfaces in hopper flows were plotted and can be fitted into parabolic surfaces. Other quantities, such as velocity fields and spatial profiles of coordination number, were investigated to support the free fall surfaces we obtained. Although inconsistent with the initial assumption, it is shown that the free fall surfaces can be statistically described and this work provides new insights for understanding the processes of hopper flows.

Effect of plastic film mulching on the grain filling and hormonal changes of maize under different irrigation conditions.

Plastic film mulching (PM) is widely utilized for maize production in China. However, the effect of PM on the grain yield of crops has not been established, and the biochemical mechanism underlying the increase or decrease in grain yield under PM is not yet understood. Grain filling markedly affects the grain yield. The objective of this study was to investigate the effects of PM on maize grain filling under different irrigation levels and the relationship of such effects with hormonal changes. In the present study, PM was compared with traditional nonmulching management (TN) under 220 mm, 270 mm and 320 mm irrigation amount, and the grain filling characters of the grains located in various parts of the ear and the hormonal changes in the grains were measured. The results indicated that at 220 mm irrigation, PM significantly increased the grain filling rate of the middle and basal grains and decreased the grain filling rate of the upper grains. At 270 mm irrigation, the PM significantly increased the grain filling rate of the all grains. At 320 mm irrigation, the PM only significantly increased the grain filling rate of the upper grains. The IAA, Z+ZR and ABA content in the grains was positively correlated with the grain weight and grain-filling rates; however, the ETH evolution rate of the grains was negatively correlated with the grain weight and grain-filling rates. These results show that the effect of PM on maize grain filling is related to the irrigation amount and that the grain position on the ear and the grain filling of the upper grains was more sensitive to PM and irrigation than were the other grains. In addition, the PM and irrigation regulated the balance of hormones rather than the content of individual hormones to affect the maize grain filling.