scholarly journals Does heat accumulation alter crop phenology, fibre yield and fibre properties of sunnhemp (Crotalaria juncea L.) genotypes with changing seasons?

2021 ◽  
Vol 20 (9) ◽  
pp. 2395-2409
Author(s):  
KASIRAJAN Subrahmaniyan ◽  
Perumal VEERAMANI ◽  
Wei-jun ZHOU
Keyword(s):  
Heat Accumulation ◽  
Crop Phenology ◽  
Crotalaria Juncea ◽  
Fibre Properties ◽  
Fibre Yield

Combining ability and heterosis studies across environments in linseed (Linum usitatissimum L.)

2011 ◽  
Vol 59 (1) ◽  
pp. 87-102 ◽  
Author(s):  
S. Sood ◽  
N. Kalia ◽  
S. Bhateria
Keyword(s):  
Seed Yield ◽  
Linum Usitatissimum ◽  
Combining Ability ◽  
Yield Components ◽  
Block Design ◽  
Linum Usitatissimum L ◽  
Randomized Block Design ◽  
Component Traits ◽  
Parental Lines ◽  
Fibre Yield

Combining ability and heterosis were calculated for fourteen lines of linseed in a line × tester mating design using twelve lines and two diverse testers in two different environments. The hybrids and parental lines were raised in a completely randomized block design with three replications to investigate seed and fibre yield and their component traits. Genetic variation was significant for most of the traits over environments. Combining ability studies revealed that the lines KL-221 and LCK-9826 were good general combiners for seed yield and most of its components, whereas LMH-62 and LC-2323 were good general combiners for yield components only. Moreover, KL-221 was also a good general combiner for fibre yield. Similarly, B-509 and Ariane were good general combiners for fibre yield and most of its components. Among the specific cross combinations, B-509 × Flak-1 was outstanding for seed yield per plant and B-509 × KL-187 and LC-2323 × LCK-9826 for fibre yield per plant, with high SCA effects. In general, the hybrids excelled their respective parents and the standard checks for most of the characters studied. Based on the comparison of mean performance, SCA effects and the extent of heterosis, the hybrids LC-2323 × LCK-9826 and B-509 × KL-221 appeared to be the most promising for both seed and fibre yield. Other promising combinations were LC-2323 × KL-210 and B-509 × Ariane for seed and fibre yield, respectively. The superiority of LC-2323, LCK-9826, KL-221, B-509 and Ariane as good general combiners was further confirmed by the involvement of these parents in the desirable cross combinations.

Accelerating laser processes with a smart two-dimensional polygon mirror scanner for ultra-fast beam deflection

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Florian Roessler ◽  
André Streek
Keyword(s):  
Energy Distribution ◽  
Real Time ◽  
Laser Processing ◽  
High Speed ◽  
Beam Deflection ◽  
Two Dimensional ◽  
Heat Accumulation ◽  
Field Programmable ◽  
Drill Holes ◽  
Average Laser

Abstract In laser processing, the possible throughput is directly scaling with the available average laser power. To avoid unwanted thermal damage due to high pulse energy or heat accumulation during MHz-repetition rates, energy distribution over the workpiece is required. Polygon mirror scanners enable high deflection speeds and thus, a proper energy distribution within a short processing time. The requirements of laser micro processing with up to 10 kW average laser powers and high scan speeds up to 1000 m/s result in a 30 mm aperture two-dimensional polygon mirror scanner with a patented low-distortion mirror configuration. In combination with a field programmable gate array-based real-time logic, position-true high-accuracy laser switching is enabled for 2D, 2.5D, or 3D laser processing capable to drill holes in multi-pass ablation or engraving. A special developed real-time shifter module within the high-speed logic allows, in combination with external axis, the material processing on the fly and hence, processing of workpieces much larger than the scan field.

scholarly journals Modeling of three-dimensional exciplex pumped fluid Cs vapor laser with transverse and longitudinal gas flow

2021 ◽  
Vol 9 ◽  
Author(s):  
Chenyi Su ◽  
Xingqi Xu ◽  
Jinghua Huang ◽  
Bailiang Pan
Keyword(s):  
Wall Temperature ◽  
Laser Power ◽  
Gas Flow ◽  
Particle Density ◽  
Fluid Velocity ◽  
Three Dimensional ◽  
Heat Accumulation ◽  
Vapor Laser ◽  
Output Laser Power ◽  
Output Laser

Abstract Considering the thermodynamical fluid mechanics in the gain medium and laser kinetic processes, a three-dimensional theoretical model of an exciplex-pumped Cs vapor laser with longitudinal and transverse gas flow is established. The slope efficiency of laser calculated by the model shows good agreement with the experimental data. The comprehensive three-dimensional distribution of temperature and particle density of Cs is depicted. The influence of pump intensity, wall temperature, and fluid velocity on the laser output performance is also simulated and analyzed in detail, suggesting that a higher wall temperature can guarantee a higher output laser power while causing a more significant heat accumulation in the cell. Compared with longitudinal gas flow, the transverse flow can improve the output laser power by effectively removing the generated heat accumulation and alleviating the temperature gradient in the cell.

scholarly journals Parameters Optimization of Auxiliary Gas Process for Double-Wire SS316L Stainless Steel Arc Additive Manufacturing

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 190
Author(s):  
Wei Wu ◽  
Jiaxiang Xue ◽  
Wei Xu ◽  
Hongyan Lin ◽  
Heqing Tang ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Additive Manufacturing ◽  
Process Parameters ◽  
Evaluation System ◽  
Gas Flow ◽  
Interactive Effect ◽  
Parameters Optimization ◽  
Heat Accumulation ◽  
Auxiliary Process ◽  
Strength And Stiffness

Serious heat accumulation limits the further efficiency and application in additive manufacturing (AM). This study accordingly proposed a double-wire SS316L stainless steel arc AM with a two-direction auxiliary gas process to research the effect of three parameters, such as auxiliary gas nozzle angle, auxiliary gas flow rate and nozzle-to-substrate distance on depositions, then based on the Box–Behnken Design response surface, a regression equation between three parameters and the total score were established to optimized parameters by an evaluation system. The results showed that samples with nozzle angle of 30° had poor morphology but good properties, and increasing gas flow or decreasing distance would enhance the airflow strength and stiffness, then strongly stir the molten pool and resist the interference. Then a diverse combination of auxiliary process parameters had different influences on the morphology and properties, and an interactive effect on the comprehensive score. Ultimately the optimal auxiliary gas process parameters were 17.4°, 25 L/min and 10.44 mm, which not only bettered the morphology, but refined the grains and improved the properties due to the stirring and cooling effect of the auxiliary gas, which provides a feasible way for quality and efficiency improvements in arc additive manufacturing.

Modeling temperature rise in multi-track reciprocating frictional sliding

2021 ◽  
pp. 135065012098823
Author(s):  
Thierry A Blanchet
Keyword(s):  
Temperature Rise ◽  
Peclet Number ◽  
Maximum Temperature ◽  
Uniform Heat Flux ◽  
Heat Accumulation ◽  
Stroke Length ◽  
Péclet Number ◽  
Maximum Temperature Rise ◽  
Rectangular Patch ◽  
Accumulation Effect

As in various manufacturing processes, in sliding tests with scanning motions to extend the sliding distance over fresh countersurface, temperature rise during any pass is bolstered by heating during prior passes over neighboring tracks, providing a “heat accumulation effect” with persisting temperature rises contributing to an overall temperature rise of the current pass. Conduction modeling is developed for surface temperature rise as a function of numerous inputs: power and size of heat source; speed and stroke length, and track increment of scanning motion; and countersurface thermal properties. Analysis focused on mid-stroke location for passes of a square uniform heat flux sufficiently far into the rectangular patch being scanned from the first pass at its edge that steady heat accumulation effect response is adopted, focusing on maximum temperature rise experienced across the pass' track. The model is non-dimensionalized to broaden the applicability of the output of its runs. Focusing on practical “high” scanning speeds, represented non-dimensionally by Peclet number (in excess of 40), applicability is further broadened by multiplying non-dimensional maximum temperature rise by the square root of Peclet number as model output. Additionally, investigating model runs at various non-dimensional speed (Peclet number) and reciprocation period values, it appears these do not act as independent inputs, but instead with their product (non-dimensional stroke length) as a single independent input. Modified maximum temperature rise output appears to be a function of only two inputs, increasing with decreasing non-dimensional values of stroke length and scanning increment, with outputs of models runs summarized compactly in a simple chart.

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