Compositional Constraints Research Articles

Evaluation of Granite Fertility Utilizing Porphyry Indicator Minerals (Zircon, Apatite, and Titanite) and Geochemical Data: A Case Study from an Emerging Metallogenic Province in the Taimyr Peninsula, Siberian High Arctic

The Taimyr Peninsula in the Russian High Arctic comprises a late Paleozoic-early Mesozoic collisional belt where several porphyry-type mineralization occurrences were identified during the last decade, making this area a potential exploration target for Cu-Mo deposits. In order to further evaluate the metallogenic potential of the poorly outcropped northeastern part of Taimyr, samples from seven granitoid intrusions were investigated in this study aimed to evaluate the granite fertility based on petrography, geochemistry, and composition of porphyry indicator minerals (zircon, apatite, and titanite). The studied intrusions represent small to moderate-sized bodies (40–800 km2) composed of biotite (±amphibole) quartz monzonites, granodiorites, granites, and biotite leucogranites that formed in the course of late Paleozoic-early Mesozoic tectono-magmatic events at the Siberian margins. The late Carboniferous Tessemsky massif represents suprasubduction granitoid series, while the Pekinskiy, Shirokinskiy, Dorozhinskiy, Kristifensenskiy, and Yuzhno-Lodochnikovskiy massifs are correlated with the early Triassic Siberian Traps LIP. The rocks of intrusions comprise a relatively uniform geochemically, predominantly magnesian, slightly peraluminous, calc-alkaline high-K amphibole-bearing I-type granitoid series with adakitic affinity, where Triassic plume-related granitoids inherit geochemical signatures of Carboniferous supra-subduction granitoids, and all rock types are marked by enrichment in LILE and negative Ta, Nb, and Ti anomalies. It is suggested that the adakitic geochemical characteristics of the Taimyr granites are a result of derivation from a relatively homogeneous mafic lower crustal source that formed at the stage of Carboniferous continental subduction and continued to produce granitic melts in the course of the early Mesozoic magmatic evolution. Whole rock geochemistry and composition of porphyry mineral indicators (zircon, apatite, and titanite) indicate that the Taimyr granites crystallized from oxidized water-saturated magmas at moderate temperatures, with the majority of samples showing characteristics typical for porphyry-fertile granites worldwide (fO2 = ΔFMQ +1 to +3 with zircon Eu/Eu* > 0.4 and apatite SO3 > 0.2 wt.%). Data from Dorozhinskiy, Kristifensenskiy, Pekinskiy, and Tessemskiy intrusions fully match geochemical criteria for porphyry-fertile granitoids, and these massifs are considered the most prospective for Cu-Mo mineralization. Granites from Shirokinskiy and Yuzhno-Lodochnikovskiy intrusions only partially match compositional constraints for fertile melts and can be considered as second-tier exploration targets. Finally, available data for the Simsovsky massif preclude its classification as a porphyry-fertile body. These conclusions are in line with previously developed exploration criteria for the northeastern Taimyr, showing that geochemical indicators of granite-fertility can be used on a regional scale in parallel with other exploration methods.

Composition and age constraints on a Hadean enriched mantle source revealed by the Paleoarchean São Tomé layered intrusion, NE Brazil

Evidence for Hadean depleted mantle reservoir(s) is well-established by mantle-derived rocks from multiple Archean complexes showing excesses in 142Nd compared to the modern mantle. Yet, the existence of an early enriched mantle source, which should have concomitantly formed during these Hadean silicate differentiation event(s), has only been recently confirmed by well-resolved 142Nd deficits measured in Paleoarchean mafic amphibolites from the São José do Campestre massif of the Borborema Province, NE Brazil. To investigate the nature and extent of this early-formed enriched reservoir, a series of samples from the Seridó belt, NE Brazil, have been investigated for their geochemical and coupled 147,146Sm-143,142Nd isotopic compositions, focusing on the Paleoarchean São Tomé layered intrusion. The São Tomé intrusion is composed of layers of metamorphosed mafic and ultramafic rocks with whole-rock trace element compositions and high olivine crystal Ni contents consistent with an incompatible trace element enriched pyroxenitic mantle source. Most analyzed samples from the Seridó belt yielded negative µ142Nd, as low as ∼ -20 (representing the lowest 142Nd/144Nd ratio ever measured in terrestrial rocks), with an average µ142Nd for the São Tomé intrusion of -9.6 ± 1.4. The São Tomé samples interpreted as the least isotopically disturbed yielded an 147Sm-143Nd isochron age of 3551 ± 368 Ma, consistent with previous zircon U-Pb ages, with an initial ε143Nd = -1.7 ± 1.2. Coupling the long-lived 147Sm-143Nd and the short-lived 146Sm-142Nd systems for the São Tomé rocks suggests a Hadean enriched mantle source formed at ∼4.44 Ga with a 147Sm/144Nd of ∼0.18, which may be complementary to the early depleted mantle recorded by Eoarchean rocks from the North Atlantic Craton, possibly formed during magma ocean crystallization. These results also imply that the record of this Hadean enriched mantle source is not restricted to the São José do Campestre massif but extends to a larger portion of the Borborema Province.

Lunar Low‐Titanium Magmatism During Ancient Expansion Inferred From Ejecta Originating From Linear Gravity Anomalies

AbstractLinear gravity anomalies (LGAs) on the Moon have been interpreted as ancient magmatic intrusions formed during the lunar expansion. The composition of such ancient subsurface intrusions may offer hints for the lunar thermodynamic state in the initial stage of lunar history. To pose a first compositional constraint on magmatism related to lunar expansion, this study analyzed the spectrum and gravity around craters on LGAs, such as Rowland, Roche, and Edison craters. Using reflectance spectra around the craters, we first surveyed non‐mare basaltic exposures. To test the LGA excavation scenario as a possible origin of the discovered exposures, we then compared the Gravity Recovery and Interior Laboratory data and post‐cratering gravity simulation with the iSALE shock physics code. Our spectral analysis reveals no basaltic exposure around the Rowland crater. Further, the observed termination of LGA at the crater rim contradicts the gravity simulation, which assumes that LGA predates the Rowland crater. These results suggest that LGA formation might postdate the Rowland formation and that lunar expansion lasted even after the Nectarian age. On the other hand, we found that both Roche and Edison craters possess basaltic exposures in their peripheries. Because the gravity reduction inside Roche crater can be reproduced in our simulation, the discovered basaltic exposures are possibly LGA materials ejected from these craters. The composition of those exposures shows that the LGA intrusions at the two locations are composed of low‐titanium magma, indicating that ancient magma during the expansion did not contain ilmenite‐rich melt, perhaps resulting from the low‐ilmenite content of the ancient upper mantle.

Pepino mosaic virus: Recombination, spatiotemporal divergence and codon usage

AbstractPepino mosaic virus (PepMV, species Potexvirus pepini) is a potexvirus of economic significance. The pathogen has become a serious threat to tomato (Solanum lycopersicum) worldwide. To gain more insights into the molecular epidemiology and evolution of PepMV, recombination analysis was carried out. Nine chimeric sequences were identified, including one probably involving host‐to‐virus gene flow. Based on the coat protein (CP) gene, PepMV isolates were classified into six genotypes and the phylogeography was reconstructed. Bayesian coalescent analysis applied to the dated genomic sequences suggested that PepMV started to expand in the early 17th century and evolved at a moderate rate. Ancestral state reconstruction supported the South American origin of PepMV. Codon usage bias analysis showed that PepMV genes had influences in addition to compositional constraints. In codon usage, PepMV is fairly similar to S. lycopersicum. Moreover, PepMV recapitulates the host's remarkable suppression of CpG and UpA dinucleotides.

Detailed chemical composition analysis of the Soi crater region on Titan

The Soi crater region (0° to 60°N, 180°W to −110°W), which includes the well-preserved Soi crater in its center, spans a region from Titan's aeolian-dominated equatorial regions to fluvially-dominated high northern latitudes. This provides a rich diversity of landscapes, one that is also representative of the diversity encountered across Titan. Schoenfeld et al. (2023) mapped this region at 1:800,000 scale and produced a geomorphological map showing that the area consists of 22 types of geomorphological units. The Visual and Infrared Mapping Spectrometer (VIMS) coverage of the region enabled the detailed analysis of spectra of 261 different locations using a radiative transfer technique and a mixing model, yielding compositional constraints on Titan's optical surface layer. Additional constraints on composition on the near-surface substrate were obtained from microwave emissivity. We have derived combinations of top surface materials between dark materials, tholins, water-ice, and methane suggesting that dark mobile organic material at equatorial and high latitudes indicates “young” terrains and compositions, while tholin/water-ice mixtures that dominate areas around latitude 35°N show a material that is older plains deposits that we interpret to be the end stage of aeolian and fluvial transport and deposition. We found no spectral evidence of CO2, HC3N, and NH3 ice. We use the stratigraphic relations between the various mapping units and the relation between the geomorphology and the composition of the surface layers to build hypotheses on the origin and evolution of the regional geology. We suggest that sedimentary deposits, likely aeolian, are dominant in the region with fluvial activity and leaching changing the nature of the top surfaces of the midlatitude areas of the Soi crater region.

A Systematic Review of Group Metacognition Researches on Online and Face-to-Face Learning Environments

Group metacognition involves a collective understanding of cognitive processes and collaborative problem-solving mechanisms within a group. This study, conducted through a systematic review of 54 studies, aims to present the evolutionary trajectory of research on group metacognition in (predominantly) online and face-to-face learning environments. It explores the definitional shifts, methodological trends, and potential connections between the quality of collaboration and studies on group metacognition in online learning environments. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) was used to report the study's results. In investigating determinants influencing group metacognition, the research examined the distribution of effective variables such as group size, composition, task complexity, and time constraints. This systematic review provides an overview of the evolutionary path for definitions of the group metacognition concept, accumulated methodological approaches, and key insights into studies that may be associated with group metacognition. Thus, it underscores the importance of customized interventions that appropriately consider variables that could affect group metacognition effectively.

A Review on Camel Milk Composition, Techno-Functional Properties and Processing Constraints.

Camel milk plays a critical role in the diet of peoples belongs to the semi-arid and arid regions. Since prehistoric times, camel milk marketing was limited due to lacking the processing facilities in the camel-rearing areas, nomads practiced the self-consumption of raw and fermented camel milk. A better understanding of the techno-functional properties of camel milk is required for product improvement to address market and customer needs. Despite the superior nutraceutical and health promoting potential, limited camel dairy products are available compared to other bovines. It is a challenging impetus for the dairy industry to provide diversified camel dairy products to consumers with superior nutritional and functional qualities. The physicochemical behavior and characteristics of camel milk is different than the bovine milk, which poses processing and technological challenges. Traditionally camel milk is only processed into various fermented and non-fermented products; however, the production of commercially important dairy products (cheese, butter, yogurt, and milk powder) from camel milk still needs to be processed successfully. Therefore, the industrial processing and transformation of camel milk into various products, including fermented dairy products, pasteurized milk, milk powder, cheese, and other products, require the development of new technologies based on applied research. This review highlights camel milk's processing constraints and techno-functional properties while presenting the challenges associated with processing the milk into various dairy products. Future research directions to improve product quality have also been discussed.

Understanding arsenic and manganese enrichment in the aquifers of the Ghaghara river basin, Middle Gangetic Plain (MGP), India: A multivariate statistical, compositional data analysis (CoDA), and receptor model approach

The focus of this study was to comprehend the spatial distribution, source apportionment, evaluation of natural background level (NBL), and mobilization mechanisms of arsenic (As) and manganese (Mn) in the Ghaghara river basin, located in the middle Gangetic plain (MGP) of India. A combination of analytical tools was employed, including multivariate statistical analysis (MSA), correlation analysis, and receptor models such as positive matrix factorization (PMF) and principal component analysis-multi linear regression (PCA-MLR). Taking into consideration the compositional constraints of the geochemical data, compositional data analysis (CoDA) methods were applied on the raw data prior to the correlation analysis and MSA. The results of MSA, correlation analysis and receptor models showed that major ion chemistry and As, Mn enrichment in groundwater were largely controlled by carbonate weathering, Fe and Mn oxyhydroxides dissolution. Anthropogenic activities, such as the infiltration of dissolved organic matter-rich water from local surface water bodies used as dumping sites and the infiltration of fertilizer-rich water from agricultural lands, were found to notably impact the groundwater geochemistry and release of As in the research area. The lower NBL of As (5.92 μg/L) compared to its mean concentrations (17.9 μg/L) in the study area also indicated that the rate of As release in groundwater through natural processes was comparatively low but various anthropogenic activities operating in the study region possibly acted as a trigger for the mobility of As from the mineral phases of the subsurface sediments. This study also highlighted the significance of applying CoDA techniques on geochemical data prior to statistical analysis, and the importance of receptor models, to better understand the nature and contribution of various natural and anthropogenic processes governing the hydrochemistry of groundwater in the alluvial aquifers.

Accurate measurement method for parallel edge spacing of sheet metal parts in aviation manufacturing

A new method, to our knowledge, is proposed to achieve high-precision measurement of parallel edge spacing for sheet metal parts in the complex industrial environment of aviation manufacturing. First, the sub-pixel edges of sheet metal parts are extracted by combining a what we believe to be a novel adaptive rolling bilateral filter and a sub-pixel edge detection algorithm based on the Canny–Steger algorithm. Then, the acquired edge data are denoised by using the clustering algorithm. Finally, a parallel line fitting algorithm, which combines an improved K-medoids algorithm with composite constraints on points and slopes, is proposed to calculate the parallel edge spacing. The results show that the method is robust to introducing noise in the edge data due to uneven illumination and various types of defects such as wear, scratches, and stains. The detection accuracy is high, with an average detection error of only 0.015 mm.

Attitude stability control for 6WID unmanned ground vehicle during steering: A collaborative controller considering minimizing tire slip energy loss

The instability of vehicle attitude and wheel slippage during turning on complex roads are key factors affecting the operational efficiency and accuracy of a variable wheelbase six-wheel independent drive unmanned ground vehicle (6WID UGV), posing a serious threat to driving safety. This article proposes a hierarchical coordinated controller to improve the attitude stability of a 6WID UGV equipped with interconnected active hydro pneumatic suspension (IAHPS) and reduce tire slip energy loss. Firstly, an integral sliding mode controller with adaptive high-order coupling factor (AHOCF-ISMC) is designed to determine the active anti roll torque required for stable roll attitude. An adaptive high-order coupling factor is introduced in the controller framework to couple physical components with different properties, avoiding overshoot and oscillation caused by integral saturation of the controller. Secondly, based on satisfying the stability of the roll attitude, the lateral stability and longitudinal traction characteristics of the vehicle are constrained and controlled. An optimization function was established to minimize tire slip energy loss within the feasible range of wheel torque determined by lateral and longitudinal control objectives. Thirdly, the particle swarm optimization algorithm was improved (IPSO) by designing adaptive weighting factors and learning factors, and is used to optimize the wheel torque distribution scheme under composite constraint conditions. Finally, the effectiveness of the coordinated controller was tested and validated in different scenarios. The results show that the designed controller has good control performance and robustness without the need to establish an accurate mathematical model, and performs well in terms of economic benefits and application prospects.

Cellular and Biophysical Applications of Genetic Code Expansion.

Despite their diverse functions, proteins are inherently constructed from a limited set of building blocks. These compositional constraints pose significant challenges to protein research and its practical applications. Strategically manipulating the cellular protein synthesis system to incorporate novel building blocks has emerged as a critical approach for overcoming these constraints in protein research and application. In the past two decades, the field of genetic code expansion (GCE) has achieved significant advancements, enabling the integration of numerous novel functionalities into proteins across a variety of organisms. This technological evolution has paved the way for the extensive application of genetic code expansion across multiple domains, including protein imaging, the introduction of probes for protein research, analysis of protein-protein interactions, spatiotemporal control of protein function, exploration of proteome changes induced by external stimuli, and the synthesis of proteins endowed with novel functions. In this comprehensive Review, we aim to provide an overview of cellular and biophysical applications that have employed GCE technology over the past two decades.

Redefining the bacteriophage mv4 site-specific recombination system and the sequence specificity of its attB and core-attP sites.

Through their involvement in the integration and excision of a large number of mobile genetic elements, such as phages and integrative and conjugative elements (ICEs), site-specific recombination systems based on heterobivalent tyrosine recombinases play a major role in genome dynamics and evolution. However, despite hundreds of these systems having been identified in genome databases, very few have been described in detail, with none from phages that infect Bacillota (formerly Firmicutes). In this study, we reanalyzed the recombination module of Lactobacillus delbrueckii subsp. bulgaricus phage mv4, previously considered atypical compared with classical systems. Our results reveal that mv4 integrase is a 369 aa protein with all the structural hallmarks of recombinases from the Tn916 family and that it cooperatively interacts with its recombination sites. Using randomized DNA libraries, NGS sequencing, and other molecular approaches, we show that the 21-bp core-attP and attB sites have structural similarities to classical systems only if considering the nucleotide degeneracy, with two 7-bp inverted regions corresponding to mv4Int core-binding sites surrounding a 7-bp strand-exchange region. We also examined the different compositional constraints in the core-binding regions, which define the sequence space of permissible recombination sites.

Combined modelling of production of merchantable phosphoric ores using parallel processors and their transportation by pipeline

This paper focuses on managing the production and transfer of phosphoric merchantable ores (MOs) in a pull-flow mode of a supply chain that is currently addressed with limited effectiveness. MOs are obtained by washing extracted source ores in parallel lines, using alternative routings that change their weight and composition, before blending in tanks to achieve the required quality defined by a set of compositional constraints. The pipe transfer program defines the batches to be transported and their schedule, considering downstream demand (a roughly stable demand from the chemistry and irregular export demands (export orders of large quantities of MOs)), preventive maintenance of pipe or washing lines and prevention of defusing and saturation in the tanks of the delivery pipe station. A daily used Decision Support System (DSS) encapsulates two models used sequentially and sharing technical, availability, capacity, and quality constraints; then, the optimal solution of the transfer model is adapted to create the order book processed by the original blending model to obtain an optimal joint production and pipe transfer program. It also provides ways to improve SC performance while considering its impact on the chemical production performance.

Comprehensive Genomics Investigation of Neboviruses Reveals Distinct Codon Usage Patterns and Host Specificity.

Neboviruses (NeVs) from the Caliciviridae family have been linked to enteric diseases in bovines and have been detected worldwide. As viruses rely entirely on the cellular machinery of the host for replication, their ability to thrive in a specific host is greatly impacted by the specific codon usage preferences. Here, we systematically analyzed the codon usage bias in NeVs to explore the genetic and evolutionary patterns. Relative Synonymous Codon Usage and Effective Number of Codon analyses indicated a marginally lower codon usage bias in NeVs, predominantly influenced by the nucleotide compositional constraints. Nonetheless, NeVs showed a higher codon usage bias for codons containing G/C at the third codon position. The neutrality plot analysis revealed natural selection as the primary factor that shaped the codon usage bias in both the VP1 (82%) and VP2 (57%) genes of NeVs. Furthermore, the NeVs showed a highly comparable codon usage pattern to bovines, as reflected through Codon Adaptation Index and Relative Codon Deoptimization Index analyses. Notably, yak NeVs showed considerably different nucleotide compositional constraints and mutational pressure compared to bovine NeVs, which appear to be predominantly host-driven. This study sheds light on the genetic mechanism driving NeVs' adaptability, evolution, and fitness to their host species.

Physics mechanisms underlying the optimization of coherent heat transfer across width-modulated nanowaveguides with calculations and machine learning

Optimization of heat transfer at the nanoscale is necessary for efficient modern technology applications in nanoelectronics, energy conversion, and quantum technologies. In such applications, phonons dominate thermal transport and optimal performance requires minimum phonon conduction. Coherent phonon conduction is minimized by maximum disorder in the aperiodic modulation profile of width-modulated nanowaveguides, according to a physics rule. It is minimized for moderate disorder against physics intuition in composite nanostructures. Such counter behaviors call for a better understanding of the optimization of phonon transport in non-uniform nanostructures. We have explored mechanisms underlying the optimization of width-modulated nanowaveguides with calculations and machine learning, and we report on generic behavior. We show that the distribution of the thermal conductance among the aperiodic width-modulation configurations is controlled by the modulation degree irrespective of choices of constituent material, width-modulation-geometry, and composition constraints. The efficiency of Bayesian optimization is evaluated against increasing temperature and sample size. It is found that it decreases with increasing temperature due to thermal broadening of the thermal conductance distribution. It shows weak dependence on temperature in samples with high discreteness in the distribution spectrum. Our work provides new physics insight and indicates research pathways to optimize heat transfer in non-uniform nanostructures.

Enrichment of Geogenic Organoiodine Compounds in Alluvial-Lacustrine Aquifers: Molecular Constraints by Organic Matter.

Organoiodine compounds (OICs) are the dominant iodine species in groundwater systems. However, molecular mechanisms underlying the geochemical formation of geogenic OICs-contaminated groundwater remain unclear. Based upon multitarget field monitoring in combination with ultrahigh-resolution molecular characterization of organic components for alluvial-lacustrine aquifers, we identified a total of 939 OICs in groundwater under reducing and circumneutral pH conditions. In comparison to those in water-soluble organic matter (WSOM) in sediments, the OICs in dissolved organic matter (DOM) in groundwater typically contain fewer polycyclic aromatics and polyphenol compounds but more highly unsaturated compounds. Consequently, there were two major sources of geogenic OICs in groundwater: the migration of the OICs from aquifer sediments and abiotic reduction of iodate coupled with DOM iodination under reducing conditions. DOM iodination occurs primarily through the incorporation of reactive iodine that is generated by iodate reduction into highly unsaturated compounds, preferably containing hydrophilic functional groups as binding sites. It leads to elevation of the concentration of the OICs up to 183 μg/L in groundwater. This research provides new insights into the constraints of DOM molecular composition on the mobilization and enrichment of OICs in alluvial-lacustrine aquifers and thus improves our understanding of the genesis of geogenic iodine-contaminated groundwater systems.

Stream sediment pollution: a compositional baseline assessment

AbstractA high concentration of potentially toxic elements (PTEs) can affect ecosystem health in many ways. It is therefore essential that spatial trends in pollutants are assessed and monitored. Two questions must be addressed when quantifying pollution: how to define a non-polluted sample and how to reduce the problem’s dimensionality. A geochemical dataset is a composition of variables (chemical elements), where the components represent the relative importance of each part of the whole. Therefore, to comply with the compositional constraints, a compositional approach was used. A novel compositional pollution indicator (CPI) based on compositional data (CoDa) principles such as the properties of sparsity and simplicity was computed. A dataset of 12 chemical elements in 33 stream-sediment samples were collected from depths of 0–10 cm in a grid of 1 km × 1 km and analyzed. Maximum concentrations of 3.8% Pb, 750 µg g−1 As, and 340 µg g–1 Hg were obtained near the mine tailings. The methodological approach involved geological background selection in terms of a trimmed subsample that could be assumed to contain only non-pollutants (Al and Fe) and the selection of a list of pollutants (As, Zn, Pb, and Hg) based on expert knowledge criteria and previous studies. Finally, a stochastic sequential Gaussian simulation of the new CPI was performed. The results of the hundred simulations performed were summarized through the mean image map and maps of the probability of exceeding a given statistical threshold, allowing the characterization of the spatial distribution and the associated variability of the CPI. A high risk of contamination along the Grândola River was observed. As the main economic activities in this area are agricultural and involve animal stocks, it is crucial to establish two lines of intervention: the installation of a surveillance network for continuous control in all areas and the definition of mitigation actions for the northern area with high levels of contamination. Graphical Abstract

Molecular insights into codon usage analysis of mitochondrial fission and fusion gene: relevance to neurodegenerative diseases.

Mitochondrial dysfunction is the leading cause of neurodegenerative disorders like Alzheimer's disease and Parkinson's disease. Mitochondria is a highly dynamic organelle continuously undergoing the process of fission and fusion for even distribution of components and maintaining proper shape, number, and bioenergetic functionality. A set of genes governs the process of fission and fusion. OPA1, Mfn1, and Mfn2 govern fusion, while Drp1, Fis1, MIEF1, and MIEF2 genes control fission. Determination of specific molecular patterns of transcripts of these genes revealed the impact of compositional constraints on selecting optimal codons. AGA and CCA codons were over-represented, and CCC, GTC, TTC, GGG, ACG were under-represented in the fusion gene set. In contrast, CTG was over-represented, and GCG, CCG, and TCG were under-represented in the fission gene set. Hydropathicity analysis revealed non-polar protein products of both fission and fusion gene set transcripts. AGA codon repeats are an integral part of translational regulation machinery and present a distinct pattern of over-representation and under-representation in different transcripts within the gene sets, suggestive of selective translational force precisely controlling the occurrence of the codon. Out of six synonymous codons, five synonymous codons encoding for leucine were used differently in both gene sets. Hence, forces regulating the occurrence of AGA and five synonymous leucine-encoding codons suggest translational selection. A correlation of mutational bias with gene expression and codon bias and GRAVY and AROMA signifies the selection pressure in both gene sets, while the correlation of compositional bias with gene expression, codon bias, protein properties, and minimum free energy signifies the presence of compositional constraints. More than 25% of codons of both gene sets showed a significant difference in codon usage. The overall analysis shed light on molecular features of gene sets involved in fission and fusion.

Robotic milling posture adjustment under composite constraints: A weight-sequence identification and optimization strategy

Robotic milling posture adjustment under composite constraints: A weight-sequence identification and optimization strategy

Material-Structure Integrated Design and Optimization of a Carbon-Fiber-Reinforced Composite Car Door

This paper develops a material-structure integrated design and optimization method based on a multiscale approach for the lightweight design of CFRP car doors. Initially, parametric modeling of RVE is implemented, and their elastic performance parameters are predicted using the homogenization theory based on thermal stress, exploring the impact of RVE parameters on composite material performance. Subsequently, a finite element model of the CFRP car door is constructed based on the principle of equal stiffness, and a parameter transfer across microscale, mesoscale, and macroscale levels is achieved through Python programming. Finally, the particle generation and updating strategies in the Multi-Objective Particle Swarm Optimization (MOPSO) algorithm are improved, enabling the algorithm to directly solve multi-constraint and multi-objective optimization problems that include various composite material layup process constraints. Case study results demonstrate that under layup process constraints and car door stiffness requirements, plain weave, twill weave, and satin weave composite car doors achieve weight reductions of 15.85%, 14.54%, and 15.35%, respectively, compared to traditional metal doors, fulfilling the requirements for a lightweight design. This also provides guidance for the lightweight design of other vehicle body components.