Spiral Grain Research Articles

Fluctuation induces conductivity and microstructural studies in Y-123: Effect of CaO inclusion

This study explored the impact of CaO as effective fine pinning centres on the interactions among thermodynamic fluctuations of superconducting parameters during the superconducting transitions in the Y-123 (YBa2Cu3O7-δ) matrix system. The investigation involved introducing varying concentrations (0.0100 wt% ≤ × ≤ 0.6000 wt%) of CaO into the Y-123 matrix through a green approach thermal treatment method annealed in an oxygen flow. TGA-DTA analysis revealed that the thermal stability of CaO exceeded that of the Y-123 matrix system. In XRD results, all specimens crystallized into orthorhombic Y-123 as the main phase, accompanied by non-superconducting phases such as Y-211 and BaCuO2, contributing to the enhancement of superconducting parameters. These inclusions of CaO induced distinct trends in grain degradation, spiral grain growth, and the appearance of homogeneous Y-123 nano-entities within the Y-123 matrix system. DC resistivity measurements investigating thermal fluctuation conductivity showed reductions in transition temperature widths (ΔTc and ΔTcMF1-offset) reaching an optimal concentration of CaO inclusion at 0.0375 wt%. Additionally, intra-granular current density at 0 K (Jc(0)) experienced significant improvements at lower concentrations, peaking at 0.0375 wt% at 11.0 ×106 A/m2. The incorporation of CaO at 0.0375 wt% proved optimal for achieving finely scaled lattice defects in intergranular and intragranular coupling, serving as effective pinning centres. This dominance in the 3D regime of thermal fluctuation reduced flux motion and improved Jc(0). The study concluded that the deficient inclusion of CaO led to the well-dispersed formation of nano-sized Y-123 particles, enhancing the superconducting parameters.

Predicting the elastic properties of Norway spruce by its morphology

Models for the elastic material properties of wood aim to predict the mechanical response of wooden structures to external loading. Traditionally, the variability of these properties in trees is described by a taxonomy of growth defects that is typically based on visual indicators in the material. This includes curvature, knots, and spiral grain models. Existing meso- and macro-scale models fail to describe the uncertainty connected to the local heterogeneity of the material. In this paper, we propose a novel meso-scale model that describes the natural variability of Norway spruce morphology and material properties based on random field theory. Our approach removes the need for a taxonomy of growth defects and enables uncertainty quantification of the stiffness and density in a straightforward fashion using simulations. This may enhance confidence for stiffness-graded applications, where the dynamic resonant behavior of wood structures is relevant and growth anomalies are present. Further, our stochastic models can generate images that realistically mimic wood patterns, which is relevant for applications like synthetic wood panels and flooring.

On the numerical assessment of bending- and torsion-induced stresses in idealised sawn timber beams

ABSTRACT When designing timber beams for bending, shear and torsion, it is common engineering practice to use analytical formulas that neglect the cylindrical nature of the orthotropic material, the annual ring orientation, spiral grain and so on. While they result in stresses that appear reasonable, the approach is in principle theoretically flawed. In this paper a 3D finite element model is used to analyse the stress levels in sawn timber beams, taking into account the radially varying and cylindrically orthotropic material parameters, as well as a number of geometrical features. The beams are assumed to be mechanically idealised without imperfections. Parametric analyses indicate that especially the annual ring orientation has a significant impact on the maximum stresses, even though the cross-sectional stress distributions have distinct similarities with common beam theory. Furthermore, a Monte Carlo simulation is performed, randomly varying all parameters within given intervals. The simulations reveal that the maximum stresses from the finite element model, in almost all cases are noticeably larger than predicted by the analytical formulas, rendering them on the unsafe side in a theoretical sense.

The Differences in Shape Stability for Hornbeam (Carpinus betulus L.) Lumber with and without Spiral Grain

Spiral grains are one of the most important tree growth defects that can remarkably affect the shape stability of lumber. This growth defect is observed by an oblique arrangement of axially oriented cell elements in the wood. This research focused on identifying and measuring selected shape changes caused by the spiral grains in the log. Hornbeam logs with spiral grain and with no spiral grain aged 60 and 52 years were selected to detect shape changes. Following the research and the norms of STN EN 1309-3 (49 1013), DIN (4074-5), and ASTM D245, it can be stated that spiral grain is an essential factor affecting the shape stability of hornbeam lumber. In the case of lumber with spiral grain, the spiral grain increased by up to 8° within three months. The warp of both types (bow, crook) increased exponentially throughout the study, peaking between the third and fourth week with an increase in warp bow of 26 mm and 17 mm in warp crook.

Design and Experiment of Grain Lifter for Sorghum Harvester

In order to solve the problems of grain lifter in sorghum harvesting, such as ear loss and serious crop leakage loss, combined with the physical and mechanical characteristics of sorghum, the segmented and reverse spiral grain lifter for sorghum harvesting and cutting table was developed, and the design method of the main structural parameters of the grain lifter was determined. The comparative test of the working effect of the clasp showed that the working effect of the cutting table with the clasp was better than that without the clasp, which effectively reduced the harvest loss of the cutting table. By using Box–Behnken experimental design method, the influence law of forward speed, tilt angle, and rotation speed of grain lifter on the rate of ear loss and harvest loss in sorghum harvesting was investigated. The regression mathematical model and response surface of the rate of ear loss and harvest loss and analysis factors were established, and the optimal working parameters of the grain lifter were determined. The forward speed was 0.8 m/s, the tilt angle of the grain lifter was 28°, and the rotation speed of the grain lifter was 330 r/min. Under these conditions, the spike loss rate was 2.01, the leakage loss rate was 2.19, and the error with the theoretical value was less than 3%, which proved the rationality of the optimized combination parameters. In the harvest of crooked and fallen sorghum, the grain lifter can effectively reduce the loss of sorghum head drop and lodging leakage, ensure the reliability of the cutting table, and achieve low loss and efficient harvest of sorghum.

Cutting speed and feed-per-knife effects on surface quality of cants produced by a chipper-canter

ABSTRACT The effects of cutting speed (CS) and feed-per-knife (FK) on the surface quality of black spruce (Picea mariana [Mill.] B.S.P.) cants processed by a chipper-canter were evaluated. Nine matched groups of logs were studied at 20, 25, and 30 m/s of CS, and 19, 25, and 32 mm of FK. Each log was processed at frozen and unfrozen conditions. Knots and grain angle measurements were taken on the cant surfaces after machining. The quality of cants was assessed utilizing waviness, roughness, and torn grain. The results showed that the surface quality was affected by CS and FK. Surface quality improved as FK decreased, likely due to decreasing cutting forces. The waviness tended to improve as CS increased, which could be partly due to the reduction of the non-cutting period between knives at higher CS. The waviness and depth of torn grain were similar for frozen and unfrozen logs. Surface quality varied within the cant, being generally poorer in the lower half. Knots and orientation of spiral grain (left-handed) contributed to diminishing the quality of surfaces. Finally, the results of correlations and regression analyses showed that optimizing the cutting conditions to decrease waviness should also reduce the depth of torn grain.

Comparative Transcriptomic and Metabolomic Analyses of Differences in Trunk Spiral Grain in Pinus yunnanensis.

Having a spiral grain is considered to be one of the most important wood properties influencing wood quality. Here, transcriptome profiles and metabolome data were analyzed in the straight grain and twist grain of Pinus yunnanensis. A total of 6644 differential expression genes were found between the straight type and the twist type. A total of 126 differentially accumulated metabolites were detected. There were 24 common differential pathways identified from the transcriptome and metabolome, and these pathways were mainly annotated in ABC transporters, arginine and proline metabolism, flavonoid biosynthesis, isoquinoline alkaloid biosynthesis, linoleic acid metabolism, phenylpropanoid, tryptophan metabolism, etc. A weighted gene coexpression network analysis showed that the lightblue4 module was significantly correlated with 2'-deoxyuridine and that transcription factors (basic leucine zipper (bZIP), homeodomain leucine zipper (HD-ZIP), basic helix-loop-helix (bHLH), p-coumarate 3-hydroxylase (C3H), and N-acetylcysteine (NAC)) play important roles in regulating 2'-deoxyuridine, which may be involved in the formation of spiral grains. Meanwhile, the signal transduction of hormones may be related to spiral grain, as previously reported. ARF7 and MKK4_5, as indoleacetic acid (IAA)- and ethylene (ET)-related receptors, may explain the contribution of plant hormones in spiral grain. This study provided useful information on spiral grain in P. yunnanensis by transcriptome and metabolome analyses and could lay the foundation for future molecular breeding.

Оценка качественных признаков древесины в селекционных программах (краткий обзор современной литературы)

The literature review concerning wood quality traits measuring in forest tree breeding programs is given. Methods of wood density measuring by Pilodin and different types of Resistograph are shortly described. Comparison study to measure Scots pine wood density by Pilodin and Resistograph revealed that Resistograph provide more precise wood density data than Pilodin. Method of measuring of wood stiffness an important wood mechanical property using acoustic velocity data is characterized. There is relationship between distortion of lumber and grain angle of wood fibers. Grain angle, i.e. spiral grain, refers to the degree of helical deviation from longitudinal arrangement of wood fibers. It can be measured with a wedge grain angle gauge hammered into a stem of a standing tree. It is shown, that microfibril angle (MFA), referring to the deviation of cellulose microfibrils in the layer of the secondary cell wall from the long axis of cell, is the main determinant of the mechanical properties of wood. There is shortly described the system of instruments with linked software (SilviScan), the main components of this system are optical cell scanner (for measurement of fiber size), X-ray densitometer (density profile and others) and X-ray diffractometer (microstructure traits). A minor negative relationship between growth and wood quality traits is noted, so the index selection is recommended under realization of tree breeding program. Some examples of genomic selection in tree breeding programs for wood quality are given.

First report of Diaporthe gardeniae causing branch blight of Gardenia jasminoides Ellis in Zhejiang Province, China.

Gardenia jasminoides Ellis, an important Chinese medicine, is cultivated on approximately 1,400 hectares in China. From August to October 2016, a severe disease affecting leaves, stems, and fruits of G. jasminoides, occurred in Cangnan (120°39'E, 27°48'N), Zhejiang province. Infected leaves or stems became shriveled, and in severe cases, young fruits presented red-brown or yellow necrotic lesions with numerous black spots. More than thirty diseased fruit and stem samples were collected, ten diseased fruits were surfacedisinfected (70% ethanol for 30 s, 1.5% sodium hypochlorite for 1 min) and kept at about 25℃ for 24 h with 80% humidity. The conidial suspension (105 conidia/ml) made of creamy drops secreted from the lesion black spots was spread onto PDA (Potato-Dextrose-Agar) and incubated at 25℃ in the dark for 7 d. Only one isolate (step01) was suspected to be the target pathogen, and other three isolates were Alternaria sp. The colony of step01 was white to grayish with an irregular edge on the front and a white to brown spiral grain on the back. Black pycnidia, produced after 20 d, were globose to subglobose, individual or overlapped, with an ostiole secreting a creamy conidial suspension. Alpha-conidia were aseptate, hyaline, oval to oblong with two oil balls, 7.4-15.9×2.4-4.5 µm (average 10.2×3.3 µm); beta-conidia were hyaline, aseptate, linetype, straight or slightly curled, 15.3-26.5×1.3-2.5 µm (average 20.8×1.6 µm). This isolate resembled Diaporthe sp. (Hansen and Barrett 1938). For species identification, DNA was extracted (Sangon Biotech Rapid Fungi Genomic DNA Isolation Kit - B518229)，and the internal transcribed spacer region (ITS), elongation factor (EF1-α), β-Tubulin (TUB), and histone H3 (HIS) of step01 were amplified using the primer pairs ITS1/ITS4, EF1-728F/ EF1-986R, BT-2a /BT-2b and CYLH3F/CYLH3R, respectively (Udayanga et al 2014, Huang et al. 2015).These sequences were submitted to GenBank as KY797655 (ITS), MF158048 (EF1- α), MF158049 (TUB), and MF158050 (HIS). In comparison with the other sequence of Diaporthe sp. using MEGA7.0 (maximum likelihood, bootstrap replications=1,000), step01 showed 100% identity with D. gardeniae. Based on their morphology and molecular identification, step01 was identified as D. gardeniae (syn. Phomopsis gardeniae). Pathogenicity was tested on three one-year-old G. jasminoides plants by stem inoculation. Two or three stems per plant were inoculated by binding a mycelial plug (5 ×12 mm), covered by humid cotton and plastic film, to the tender stem. A total of two plants were treated. Plants were kept at about 25℃ for 4 weeks. Control plants were inoculated with PDA plugs. Leaf blight started from the apex, extended to the stalk, and the leaves finally fell off. Three months after inoculation, symptoms developed on the underlying leaves, the stem was withered with black spots, a pattern like that observed in the field. No symptoms appeared in the control leaves. Five identical colonies were re-isolated from symptomatic tissues and identified again as D. gardeniae, fulfilling the Koch's postulates. Several fungi are associated with canker, leaf spot, and fruit rot in Gardenia throughout China, including Pestalotiopsis sp. (Huang et al. 2006), Botryosphaeria dothidea (Dong et al. 2016), and Phoma sp. (Luo et al. 2016). To the best of our knowledge, this is the first report of D. gardenia infecting G. jasminoides Ellis in Zhejiang Province, China.

Alumina-based ceramic mold with integral core and shell for hollow turbine blades fabricated by laser powder bed fusion

Alumina-based ceramic molds are extensively applied in investment casting processes of hollow turbine blade due to their outstanding high-temperature chemical stability and creep resistance. Herein, laser powder bed fusion ( L -PBF) method was utilized to fabricate an alumina-based ceramic mold with integral core and shell (CMCS). The influences of the component contents in the composite powder on fluidity and packing density were comprehensivley studied, and the optimized formulation for the composite powder was consequently determined as 88 wt% mixed spherical alumina (coarse: fine = 9:1), 12 wt% epoxy resin E12, and 0.1 wt% fumed silica. The vacuum infiltration process was adopted to improve mechanical properties of alumina ceramic after the sintering, where the solid loading of ceramic slurry was investigated. The CMCS was divided into two parts for fabrication, i.e., the core&shell and the base with a spiral grain selector, which could facilitate convenient of cleaning residual powder due to enlarged openings. After the first infiltration and pre-sintering, the separated two parts were bonded by a ceramic binder and then underwent second infiltration and final-sintering to obtain a complete CMCS. The alumina-based ceramic fabricated through L -PBF and post-treatment possessed low sintering shrinkage (1.51–2.03%), adequate apparent porosity (30.82 ± 0.01%), and room-temperature strength (13.03 ± 2.90 MPa for unbonded specimen, 9.72 ± 1.34 MPa for bonded specimen). Strikingly, the subsequent casting experiment has proved that the method proposed in this paper is promising to fabricate superior alumina-based CMCSs.

A Geometry Optimization of Spiral Grain Selector During Directional Solidification of Nickel‐Based Superalloy

A spiral grain selector with excellent geometric parameters can ensure qualified single-crystal (SX) is selected while decreasing lesser thermal gradient (G) during casting of SX nickel-based superalloy . In this paper, three configurations of spiral grain selectors with different height of starter block (H = 18, 25, 35 mm) and same spiral passage are adopted. Based on the quantitative analysis of orientation distribution of grains in starter block, it is found that the deviation of <001> oriented grains in the projection zone of spiral passage inlet (circle with a diameter of 4 mm) are smaller than grains of overall cross-section (circle with a diameter of 10 mm), which verify that starter block with smaller diameter have better optimization effect of grain orientation. Moreover, the average deviation of <001> oriented grains decreases to a range of 6.6–10.8° when the height of starter block is 18–27 mm, and SX selection is completed on the position of less than half turn in spiral passage regardless of the number of grains in the inlet position. Finally, a modified spiral grain selector is designed from the perspective of practical production, of which total height is reduced by at least 15 mm, and can decrease lesser G at some extent during casting .

Induction of compression wood inhibits development of spiral grain in radiata pine

Summary Spiral grain refers to the helical patterns formed by the wood grain in the trunks of many tree species. In most gymnosperms, grain near the pith is vertical but wood formed after several years of growth has a slight to pronounced left-handed twist. Grain changes presumably involve the slow rotation of cells within the vascular cambium, but the mechanisms that allow this reorientation to occur remain unclear. Understanding this process is, however, important as the presence of strong spiral grain within the corewood of gymnosperms is a major wood quality issue devaluing cut timber. In this study, we measured wood grain in stems of Pinus radiata (radiata pine) saplings through reconstructions of resin canals that follow the grain, visualised by serial sectioning and scanning with circularly polarised light, and through X-ray computed microtomography (μCT) and image analysis in ImageJ. Vertical trees retained a symmetrical grain pattern that was weakly right-handed near the pith, but which became progressively more left-handed during the first eight months of growth. In tilted trees, however, the development of left-handed grain was inhibited by the formation of compression wood on the lower side of the tree whereas the wood on the upper side of the tree developed increasingly more left-handed grain as in the vertical controls. These results demonstrate that a previously unidentified link exists between compression wood formation and the inhibition of grain development.

A comprehensive understanding of grain selection in spiral grain selector during directional solidification

• The grain selection in spiral selector is a coupling process where high order dendrites branch in the front side and primary dendrites disappear in the back side. And it is influenced by a combination effect of “space expansion mechanism”, “geometrical restriction mechanism” and “competitive grain growth”. • The smaller of the take off angle (θ) is, the larger space and the stronger driving force high order dendrites will get, and the higher efficiency the selector will be • Grain with preferred secondary dendrites instead of preferred primary dendrites could outcompete during grain selection, and this is the reason why spiral grain selector cannot optimize the orientation of the primary dendrites. It is of great importance to further investigate grain selection mechanism for the production of single crystal (SX) turbine blade because a single crystal with optimized crystal orientation will enhance service performance of the blade severely. In this paper, single crystals with different deviation angles, i.e. 6°, 12° and 29°, were obtained using directional solidification under the same casting conditions. It has been found that the grain selection in spiral selector is a coupling process where high order dendrites branch in the front side and primary dendrites disappear in the back side based on the metallographic analysis and electron back scatter diffraction (EBSD). Considering the development of liquid/solid interface by numerical simulation, a combination effect with space expansion, geometrical restriction and grain competition was proposed for spiral grain selection. The space expansion mechanism dominates the process as it provides growth space and driving force for high order dendrites advancing. Thereby, the smaller the take-off angle ( θ ) is, the larger space and the stronger driving force high order dendrites will get, and the higher efficient the selector will be. The competitive growth between the secondary dendrites plays more contribution than that of primary dendrites, i.e. grain with preferred secondary dendrites instead of preferred primary dendrites could outcompete during grain selection, and this is the reason why spiral grain selector cannot optimize the orientation of the primary dendrites. These findings provide experimental evidence for spatial control of SX growth, and benefit the sophistic casting fields such as turbine blade casting for improved yield.

Effect of competitive crystal growth on microstructural characteristics of directionally solidified nickel-based single crystal superalloy

Directionally solidified single crystal superalloy test bars were prepared by the spiral grain selection method. The microstructural evolution and orientation characteristics of the starter block and spiral part were studied, and the influence of the competitive growth of crystals on the microstructural characteristics was analyzed. The results show that the divergent grain groups, with small size and randomly oriented grains, appear at the bottom of the start block due to the chilling effect, which is an important area for competitive growth. As the height of the starter block increases, the primary dendrite spacing increases, and the grain density decreases; furthermore, the proportion of grains with an orientation deflection angle less than 10° gradually increases. The <001> texture gradually becomes stronger as the height of the starter block increases, which indicates that the competitive growth of crystals gradually weakens. At the initial stage of the crystal selection in the spiral part, the obstacle of adjacent grains and spiral passage is the main working mechanism. The grains located at the inner side of the front edge of the spiral passage have the growth advantage. The single crystal screening process is achieved at about two-thirds of the spiral height, and the single crystal with the orientation deviation angle of 6.7° from the casting axis is prepared.

Study on the formation and competitive growth mechanism of stray grains during spiral grain selector of nickel-based single crystal superalloy

Microstructure evolution and competitive grain growth in the spiral part of a single crystal sample whose crystal orientation deviating from the axial direction was analyzed. The results showed that the appearance of stray grains in the spiral part and the elimination of the originally preferred orientation grains by the competitive growth of stray grains are the reasons for the single-crystal orientation deviation defect. It was indicated that stray grains tend to nucleate at the initial stage of crystal selection in the spiral part. The inclined temperature gradient in the spiral part promoted the development of stray grains, whose growth direction was closer to the direction of the heat flow. Stray grains maintained the competitive growth in the spiral part, and a single crystal with the orientation deviated from the expected direction of 〈001〉 is formed.

Microstructural Characterization of Ni-Base Superalloy As-Cast Single Crystal (CMSX-4)

The as-cast microstructure of a single-crystal CMSX-4 Ni-base superalloy produced by directional solidification was studied. The 〈100〉 misorientation of the angled and spiral grain selectors was evaluated for 3.33 and 5.0 mm/min withdrawal rates. The dendritic microstructure presented primary dendrite arm spacing around 370 µm (for a withdrawal rate of 3.33 mm/min) and 320 µm (for 5.0 mm/min); and interdendritic γ–γ′ islands, whose volume fraction was around 5.4% (for 3.33 mm/min) and 6.1% (for 5.0 mm/min). The microsegregation profiles of one withdrawal condition (for 5.0 mm/min) were used to extrapolate the solidus and γ′ solvus temperatures using the Thermo-Calc software. These microsegregation profiles of the as-cast microstructure also affected the solid-state γ′ precipitation in terms of shape, size and volume fraction. In the center of the dendrite, the γ′ precipitates were regularly cubic-shaped with a face of approximately 0.5 µm and a volume fraction of 55%. In the periphery of the dendrite, the morphology of the γ′ precipitates was more asymmetric, and the volume fraction of the γ′ phase increased to 65%. Two morphologies of the interdendritic γ–γ′ islands, fine and coarse, were observed, and a eutectic solidification sequence was proposed. The results indicated that the chemical composition of the interdendritic liquid progressed from hypoeutectic (fine interdendritic structure) to hypereutectic (coarse interdendritic structure) during the solidification.

Influence of disintegration technologies on particle structure and its mechanical properties

ABSTRACT Wood is a highly optimised lightweight material showing excellent mechanical properties in the fibre direction. However, strength and stiffness are low perpendicular to grain. Due to knots, stem taper and spiral grain, the wood material includes local and global fibre deviations. Mechanical disintegration of logs into veneers and sawn timber is more or less ignoring the orientation of the natural wood structure, reducing mechanical properties of the grown tree. This is also true for particle production processes e.g. for OSB or particleboard, which also applies cutting and crushing technologies. As a result, conventional mechanical disintegration of logs means, the destruction of a highly optimised structure, which is always accompanied by a significant reduction of mechanical properties. The basic idea of the novel non-cutting chipless particle production process is to preserve the natural structure by employing squeezing and shear forces. These squeezing and shear forces lead to the mechanical disintegration of the logs primarily in the fibre direction, whereby long fibrous particles, so-called macro-fibres, are gained. Macro-fibres gained from this process prove excellent strength properties.

Grain Optimization: Optimizing Grain Selection Design in the Single-Crystal Solidification of Ni-Based Superalloys (Crystal Research and Technology 12/2018)

Crystal Research and TechnologyVolume 53, Issue 12 1870022 Cover PictureFree Access Grain Optimization: Optimizing Grain Selection Design in the Single-Crystal Solidification of Ni-Based Superalloys (Crystal Research and Technology 12/2018) First published: 13 December 2018 https://doi.org/10.1002/crat.201870022AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Graphical Abstract This figure represents selection phenomenon of single crystal during directional solidification. The process begins by arbitrarily nucleation of equiaxed grains at the copper chill contact area. Further progress of solidification brings about a columnar structure which is accompanied by competitive grain growth. A single grain finally encompass the upper part after solidification of spiral grain selector has come to an end. More details can be found in article number 1800108 by Fazlollah Sadeghi, Ahmad Kermanpur, and Ebrahim Norouzi. Volume53, Issue12December 20181870022 RelatedInformation

Optimizing Grain Selection Design in the Single‐Crystal Solidification of Ni‐Based Superalloys

AbstractAn attempt is made to model the design of grain selection during single‐crystal solidification of an Ni‐based superalloy by the Bridgman method. Various geometrical designs of the starter block and spiral grain selector are chosen and their effects on crystal orientation of the single‐crystal part are studied. The competitive grain selection is simulated utilizing the cellular automaton finite element module of the ProCAST software. The simulated results are validated against the experimental observation of grain structure along with the crystal orientation measured by the electron backscatter diffraction (EBSD) and rotational orientation X‐ray diffraction (RO‐XRD) techniques. The results show that in order to obtain the single crystal with a minimum deviation from longitudinal axis, the height and diameter of the starter block as well as the height and the take‐off angle of the spiral should be optimized. It is found that the diameter/height ratio of the starter block should be less than 0.6 to obtain a well‐oriented single crystal prior to entrance of solidification front into the spiral. The height of starter block is found to be more influential than its diameter in selecting the suitable single grain.

English

Women in rural areas perform a major part of all agricultural operations like weeding, transplanting, sowing, harvesting, cleaning, storage etc. Technological empowerment of women is the need of the day for betterment of agriculture and agricultural production system. Hence, the study was conducted with an objective to popularize the improved agricultural technologies in different production systems. The trainings were conducted in different villages namely Dummawad, Marewad, Lokur and Mudhol taluk and about 160 farm women were trained. The pre & post knowledge tests were executed before and after the training programmes. The results revealed that the farm women had less knowledge regarding improved technologies namely serrated sickle, groundnut decorticator, cycle weeder and were not aware of fertilizer trolley, saral kurpi, sapling transplanter, spiral grain separator, maize sheller and bhendi plucker. The post test scores revealed that farm women had maximum knowledge gain with respect sapling transplanter followed by spiral grain separator, saral kurpi and cycle weeder. Thus, such trainings on improved tools/implements & machinery empowers the rural women with technical knowledge and enhances the agricultural productivity.