CALIBRATION OF A CFD METHODOLOGY FOR THE SIMULATION OF ROUGHNESS EFFECTS ON FRICTION AND HEAT TRANSFER IN ADDITIVE MANUFACTURED COMPONENTS

It is well-known from the literature that surface roughness significantly affects friction and heat transfer. This is even more evident for additive manufactured (AM) components, which are taking an increasingly important role in the gas turbine field. However, the exploitation of numerical approaches to improve their design is hindered by the lack of dedicated correlations and CFD models developed for such high roughness conditions. Usually the additive manufactured components are simulated considering the surfaces as smooth or applying an equivalent sand-grain roughness (ks) that results in a velocity shift in the boundary layer. However, determining a priori the most appropriate value of ks is challenging, as dozens of correlations are available, returning scattered and uncertain results. A previous work proved how the CFD prediction of friction and heat transfer returns significant deviations, even exploiting the ks values obtained from experimental tests on the very same test case. That work also allowed identification of a promising CFD methodology based on friction and thermal corrections proposed by Aupoix from ONERA. The aim of this work is to further the assessment and calibration activity of the model, by analyzing additional experimental data of friction factor and Nusselt number from new test cases considering different geometries and flow conditions. The new coupons consisted of straight circular channels and wavy channels. This work represents a further step in the generation of a more validated and general methodology for the high-fidelity CFD analysis of additive-manufactured components.

Use of Pedotransfer Functions in the Rosetta Model to Determine Saturated Hydraulic Conductivity (Ks) of Arable Soils: A Case Study

A key parameter for the design of soil drainage and irrigation facilities and for the modelling of surface runoff and erosion phenomena in land-formed areas is the saturated hydraulic conductivity (Ks). There are many methods for determining its value. In situ and laboratory measurements are commonly regarded as the most accurate and direct methods; however, they are costly and time-consuming. Alternatives can be found in the increasingly popular models of pedotransfer functions (PTFs), which can be used for rapid determination of soil hydrophysical parameters. This study presents an analysis of the Ks values obtained from in situ measurements conducted using a double-ring infiltrometer (DRI). The measurements were conducted using a laboratory permeability meter (LPM) and were estimated using five PTFs in the Rosetta program, based on easily accessible input data, i.e., the soil type, content of various grain sizes in %, density, and water content at 2.5 and 4.2 pF, respectively. The degrees of matching between the results from the PTF models and the values obtained from the in situ and laboratory measurements were investigated based on the root-mean-square deviation (RMSD), Nash–Sutcliffe efficiency (NSE), and determination coefficient (R2). The statistical relationships between the tested variables tested were confirmed using Spearman’s rank correlation coefficient (rho). Data analysis showed that in situ measurements of Ks were only significantly correlated with the laboratory tests conducted on intact samples; the values obtained in situ were much higher. The high sensitivity of Ks to biotic and abiotic factors, especially in the upper soil horizons, did not allow for a satisfactory match between the values from the in situ measurements and those obtained from the PTFs. In contrast, the laboratory measurements, showed a significant correlation with the Ks values, as estimated by the models PTF-2 to PTF-5; the best match was found for PTF-2.

Genome-Wide Identification and Analysis of the Metallothionein Genes in Oryza Genus

Metallothionein (MT) proteins are low molecular mass, cysteine-rich, and metal-binding proteins that play an important role in maintaining metal homeostasis and stress response. However, the evolutionary relationships and functional differentiation of MT in the Oryza genus remain unclear. Here we identified 53 MT genes from six Oryza genera, including O. sativa ssp. japonica, O. rufipogon, O. sativa ssp. indica, O. nivara, O. glumaepatula, and O. barthii. The MT genes were clustered into four groups based on phylogenetic analysis. MT genes are unevenly distributed on chromosomes; almost half of the MT genes were clustered on chromosome 12, which may result from a fragment duplication containing the MT genes on chromosome 12. Five pairs of segmental duplication events and ten pairs of tandem duplication events were found in the rice MT family. The Ka/Ks values of the fifteen duplicated MT genes indicated that the duplicated MT genes were under a strong negative selection during evolution. Next, combining the promoter activity assay with gene expression analysis revealed different expression patterns of MT genes. In addition, the expression of OsMT genes was induced under different stresses, including NaCl, CdCl2, ABA, and MeJ treatments. Additionally, we found that OsMT genes were mainly located in chloroplasts. These results imply that OsMT genes play different roles in response to these stresses. All results provide important insights into the evolution of the MT gene family in the Oryza genus, and will be helpful to further study the function of MT genes.

Dynamic Diversity of NLR Genes in Triticum and Mining of Promising NLR Alleles for Disease Resistance

Bread wheat is an essential crop with the second-highest global production after maize. Currently, wheat diseases are a serious threat to wheat production. Therefore, efficient breeding for disease resistance is extremely urgent in modern wheat. Here, we identified 2012 NLR genes from hexaploid wheat, and Ks values of paired syntenic NLRs showed a significant peak at 3.1–6.3 MYA, which exactly coincided with the first hybridization event between A and B genome lineages at ~5.5 MYA. We provided a landscape of dynamic diversity of NLRs from Triticum and Aegilops and found that NLR genes have higher diversity in wild progenitors and relatives. Further, most NLRs had opposite diversity patterns between genic and 2 Kb-promoter regions, which might respectively link sub/neofunctionalization and loss of duplicated NLR genes. Additionally, we identified an alien introgression of chromosome 4A in tetraploid emmer wheat, which was similar to that in hexaploid wheat. Transcriptome data from four experiments of wheat disease resistance helped to profile the expression pattern of NLR genes and identified promising NLRs involved in broad-spectrum disease resistance. Our study provided insights into the diversity evolution of NLR genes and identified beneficial NLRs to deploy into modern wheat in future wheat disease-resistance breeding.

Inhibition of phospholipase A2 by Virasole derivation

Kinetics of phosphatidylcholine (PC) hydrolysis under the action of pancreatic phospholipase A2 IB, (EC 3.1.1.4, PLA2) in the presence of a lipophilic derivative of the antiviral drug Virazole 1-(3-((tert-butyldimethylsilyl)oxy)-4-hydroxy-5- (((4-methoxyphenyl)diphenylmethoxy)methyl)tetrahydrofuran-2-yl)-1H-1,2,4-triazole-3-carboxamide (Virazole2ЗГ) was studied. The both steps of phospholipolysis were quantitatively characterized: the binding of the enzyme to the lipid-water interface (Ks) and directly the catalytic act (Km) with the determination of the maximum reaction rate (Vmax). It was found that Virazole2ЗГ at a concentration of 0.5 μmol/ml does not affect the Ks value; on the contrary, the Michaelis constant, Km, increases by a factor of 1.8 along with the constancy of the parameter Vmax. Based on the constancy of the Ks values, it seems to be assumed that there is no inhibition of the disintegration of the enzyme-micelle complex in the presence of the effector under the studied reaction conditions. The kinetic parameters of the reaction (the increase in Km and the constancy of Vmax in the presence of Virazole2ЗГ) testify in favor of a moderate competitive inhibition of pancreatic PLA2, Ki = 65 mM, which indicates the possibility of searching for the biological activity of the anti-pancreatitis action in the series of pro-drugs of nucleoside nature.

Shade-Grown Coffee in Colombia Benefits Soil Hydraulic Conductivity

Secondary tropical forests and coffee agroforestry systems contain fewer trees than native forests but can positively impact soil hydrological functions, such as water infiltration compared to the pasture land that they replace. However, for both land uses it remains in how far the soil hydraulic characteristics are comparable to that of native forest. Therefore, we investigated the saturated hydraulic conductivity (Ks) and some hydrophysical soil attributes in four land-use types: (i) a shade-grown coffee; (ii) a natural regenerated forest 15 years ago; (iii) a pasture; and (iv) a reference forest, in the municipality of La Jagua de Ibirico, César department, Colombia. We determined historical land use and conducted soil sampling, using the Beerkan method to determine the Ks values. We also measured canopy cover, vegetation height, diameter at breast height and total number of trees in the forest covers. Our results indicate that Ks values were similar for the coffee and the reference forest, reflecting the positive effect of trees on soil hydrological functioning in agroforestry systems. Our results suggest that 15 years of forest regeneration after land abandonment in Sub-Andean Forest, can improve the soil hydraulic attributes. Additionally, soil water repellency was observed for the reference forest soil.

Detecting Financial Statement Fraud with Interpretable Machine Learning

In this study, we explored a stable and explainable model in the detection of financial fraud. To effectively handle imbalanced datasets, we selected the Smote oversampling algorithm with the highest AUC value and compared it with Borderline Smote and ADASYN algorithms. Using the MCB method, we found that the Adaptive Lasso algorithm had higher stability than SCAD, MCP, Stepwise, and SQRT Lasso algorithms. Moreover, the AUC value was improved by WoE encoding and IV value testing of the features. Finally, we ranked the fraud factors based on the importance of the features, and the partial dependence function was used to make the model interpretable. By comparing the AUC and KS values, the integrated models XGBoost, LightGBM, and RF showed better ability to identify financial fraud compared with traditional models such as SVM and LR.

Calibration of a CFD Methodology for the Simulation of Roughness Effects on Friction and Heat Transfer in Additive Manufactured Components

It is well-known from the literature that surface roughness significantly affects friction and heat transfer. This is even more evident for additive manufactured (AM) components, which are taking an increasingly important role in the gas turbine field. However, the exploitation of numerical approaches to improve their design is hindered by the lack of dedicated correlations and CFD models developed for such high roughness conditions. Usually the additive manufactured components are simulated considering the surfaces as smooth or applying an equivalent sand-grain roughness (ks) that results in a velocity shift in the boundary layer. However, determining a priori the most appropriate value of ks is challenging, as dozens of correlations are available, returning scattered and uncertain results. A previous work proved how the CFD prediction of friction and heat transfer returns significant deviations, even exploiting the ks values obtained from experimental tests on the very same test case. That work also allowed identification of a promising CFD methodology based on friction and thermal corrections proposed by Aupoix from ONERA. The aim of this work is to further the assessment and calibration activity of the model, by analyzing additional experimental data of friction factor and Nusselt number from new test cases considering different geometries and flow conditions. The new coupons consisted of straight circular channels and wavy channels. This work represents a further step in the generation of a more validated and general methodology for the high-fidelity CFD analysis of additive-manufactured components.

Run duration effects on the hydrodynamic properties of a loam soil estimated by steady-state infiltration methods

Steady-state methods of analysis of single-ring infiltration data are commonly applied but the duration of an infiltrometer experiment is often established quite subjectively under the premise that, generally, infiltration stabilizes rather quickly in the field. For a loam soil, the effect of the duration of a beerkan run on sorptivity, S, and saturated hydraulic conductivity, Ks, was tested by using the BEST (Beerkan Estimation of Soil Transfer parameters)-steady and SSBI (Steady version of the Simplified method based on a Beerkan Infiltration run) methods of data analysis. The standard experiment, based on a total of 15 water volumes each establishing an initial ponding depth of ~0.01 m (on average, 0.32 hours of infiltration), yielded approximately two and >100 times higher S and Ks values, respectively, than a long run (117 water volumes or 8.1 hours). Stabilization was faster for S (approximately in 3 hours) than Ks (6 hours). Similar Ks values were obtained with BEST-steady (192-261 mm/h) and the SSBI method (177-184 mm/h) for the standard run but not for the long-duration run (1.5-2.1 and 20-21 mm/h, respectively). This discrepancy was due to the fact that more information on the infiltration process is used by BEST-steady (total duration, total infiltrated water, steady-state infiltration rate) than the SSBI method (only the latter variable). In conclusion, Ks estimates are very sensitive to the used water volume for the run. The run duration should not only depend on attainment of near steadiness but also on the possibility to capture the soil’s hydraulic behavior in a representative situation for the hydrological process of interest. The possibility to use the hydrodynamic soil properties determined with the tested methodology to simulate rainfall effects on soil structure should be tested in the near future.

Identification, Expression and Co-Expression Analysis of R2R3-MYB Family Genes Involved in Graft Union Formation in Pecan (Carya illinoinensis)

Plant R2R3-MYBs comprise one of the largest transcription factor families; however, few R2R3-MYB genes in pecan have been functionally analyzed due to the limited genome information and potential functional redundancy caused by gene duplication. In this study, 153 R2R3-MYB genes were identified and subjected to comparative phylogenetic analysis with four other plant species. Then, the pecan R2R3-MYB gene family was divided into different clades, which were also supported by gene structure and motif composition results. Fifty-two duplication events including 77 R2R3-MYB genes were identified in this gene family, and Ka/Ks values showed that all of the duplication events were under the influence of negative selection. Expression levels of pecan R2R3-MYB genes during the graft union formation process were further investigated using RNA-seq with four different timepoints after grafting, namely, 0, 8, 15 and 30 d. Sixty-four differentially expressed R2R3-MYB genes were identified and showed different expression patterns after grafting. Co-expression networks were further constructed to discover the relationships between these genes. The co-expression networks contained 57 nodes (R2R3-MYB genes) and 219 edges (co-expression gene pairs) and CIL1528S0032 contained the maximum number of edges. Fifteen genes contained more than 10 edges; the majority of these were up-regulated during graft union formation and verified by qRT-PCR. This study provides a foundation for functional analysis to investigate the roles that R2R3-MYBs play in graft union formation in pecan and identify the key candidate genes.