Study of the Possibilities of Obtaining Powder Materials by Rotational Turning with Multi-Faceted Cutters

Composite materials obtained through powder metallurgy methods are increasingly applied in various industries, particularly in aviation and rocket and space equipment which use their high specific strength, resistance to high temperatures and other properties. Producers of composite materials use various metallic and non-metallic materials (fibres and powders) as fillers [1-2]. For example, the high plasticity (moldability) of aluminium powders allows utilizing them as a matrix material in moulding of composites using various methods of rolling, extrusion, and intense plastic deformation [3-5]. However, the widespread use of chip as a raw material for the production of composites is hampered by the complexities in obtaining powders with granules of the necessary shape and size.

Fabrication of Conically Shaped CuCr1 Chrome Bronze Products by Wire-Feed Electron Beam Additive Manufacturing

The structure and properties of conically shaped products made of CuCr1 chrome bronze obtained by wire-feed electron beam additive technology have been investigated. The studies show that the organization of the structure in the samples fully corresponds to the peculiarities of the printing process and heat removal from the samples. The structure is represented by large grains elongated in the direction of heat removal. Chromium in the samples is mainly localized in the form of particles located between the dendrite arms. Near the substrate, intense mixing of the bronze with the substrate material (steel 321) is observed. The mechanical properties of the conical and cylindrical sample parts material are at a fairly close level. The samples are characterized by low values of yield strength, low values of tensile strength and high plasticity. Near the substrate, the mechanical properties of the specimens increase.

Diurnal RNAPII-tethered chromatin interactions are associated with rhythmic gene expression in rice

Background The daily cycling of plant physiological processes is speculated to arise from the coordinated rhythms of gene expression. However, the dynamics of diurnal 3D genome architecture and their potential functions underlying the rhythmic gene expression remain unclear. Results Here, we reveal the genome-wide rhythmic occupancy of RNA polymerase II (RNAPII), which precedes mRNA accumulation by approximately 2 h. Rhythmic RNAPII binding dynamically correlates with RNAPII-mediated chromatin architecture remodeling at the genomic level of chromatin interactions, spatial clusters, and chromatin connectivity maps, which are associated with the circadian rhythm of gene expression. Rhythmically expressed genes within the same peak phases of expression are preferentially tethered by RNAPII for coordinated transcription. RNAPII-associated chromatin spatial clusters (CSCs) show high plasticity during the circadian cycle, and rhythmically expressed genes in the morning phase and non-rhythmically expressed genes in the evening phase tend to be enriched in RNAPII-associated CSCs to orchestrate expression. Core circadian clock genes are associated with RNAPII-mediated highly connected chromatin connectivity networks in the morning in contrast to the scattered, sporadic spatial chromatin connectivity in the evening; this indicates that they are transcribed within physical proximity to each other during the AM circadian window and are located in discrete “transcriptional factory” foci in the evening, linking chromatin architecture to coordinated transcription outputs. Conclusion Our findings uncover fundamental diurnal genome folding principles in plants and reveal a distinct higher-order chromosome organization that is crucial for coordinating diurnal dynamics of transcriptional regulation.

Summer stream habitat preferences of Nunavik anadromous Arctic char (Salvelinus alpinus) fry and parr

Arctic char is a fish species known to occupy diverse habitats within the Arctic region. However, summer habitat use during the juvenile stage of the anadromous form is largely unknown. The present study aims to characterize fry and parr summer habitat preferences. Surveys were conducted by electrofishing, associated with physical habitat characterization on several rivers of the Ungava Bay, Nunavik, Canada. At the microhabitat and station scales, fry showed significant habitat preferences for shallow water and slow velocity. At the mesohabitat scale, fry showed a significant habitat selectivity for riffles. This habitat selectivity implies that habitat models can be built to evaluate the potential of habitat suitability for Arctic char fry. However, no significant habitat selectivity was found for parr. Parr size was nonetheless positively correlated with velocity, which was found to be a limitative factor for juvenile habitat use. This first attempt at modeling juvenile anadromous Arctic char habitat in rivers emphasizes the importance of selecting an appropriate spatial scale and reiterates the fact that parr showed relatively high plasticity in stream habitat selection.

Residue from coal combustion for plastic soil improvement

The combustion of coal in Hoffman-type furnaces generates ash as one of the process residues. This research seeks to make use of this residue to improve plastic subgrade soils in tertiary roads, considering that in Colombia a large percentage of these are not paved. A soil with high plasticity has been selected to make mixtures with ash dosages that vary from 0% to 15% with respect to the dry weight of the soil. To determine the variation of the physical and mechanical properties of the soil-ash mixtures tests of consistency limits, compaction tests, and California bearing ratio were carried out. The results showed that the mixture in which 12% of the coal combustion residue is added to the soil, as a percentage for the dry weight of the soil, has a better physical behavior and bearing capacity than the soil in its natural state. obtaining an increase of up to 75% in the California bearing ratio.

Personality and Walkability: Predicting Walking Behaviour in Urban Settings using the Higher Order Factors of the Big Five amongst Malaysian Adults

Walkability has now been a popular policy to be adopted in the city centre as traffic congestion and inefficient public transportation have affected the mobility of the urban users prior to the pandemic. The pandemic has paved more efforts to improve the design of urban spaces to increase walkability in the cities. In the attempt to predict walking activity amongst Malaysian adults psychologically, a personality test using Big Five Aspect Scales (BFAS) was conducted in relation to individual walking frequency in urban settings. Structural equation modelling (SEM) was used to analyze the predicting capacity of personality constructs control by general intelligence in relation to walking behaviour. The results show that the higher order meta-traits of the big five personality traits which are Stability (Neuroticism, Agreeableness, and Conscientiousness) and Plasticity (Extraversion and Openness to Experience) can be used as a reliable predictor for individual walking behaviour. As hypothesized, walking behaviour amongst Malaysians was characterized by reversed Stability (r = -.58) and high Plasticity (r = .76). The implication suggested the necessity of cognitive navigability and design predictability metrics of urban design cognitive performance in influencing the psychological factor of walking behaviour

Interleukin-8 in Melanoma Pathogenesis, Prognosis and Therapy—An Integrated View into other Neoplasms and Chemokine Networks

Cutaneous melanoma accounts for only about 7% of skin cancers but is causing almost 90% of deaths. Melanoma cells have a distinct repertoire of mutations from other cancers, a high plasticity and degree of mimicry toward vascular phenotype, stemness markers, versatility in evading and suppress host immune control. They exert a significant influence on immune, endothelial and various stromal cells which form tumor microenvironment. The metastatic stage, the leading cause of mortality in this neoplasm, is the outcome of a complex, still poorly understood, cross-talk between tumor and other cell phenotypes. There is accumulating evidence that Interleukin-8 (IL-8) is emblematic for advanced melanomas. This work aimed to present an updated status of IL-8 in melanoma tumor cellular complexity, through a comprehensive analysis including data from other chemokines and neoplasms. The multiple processes and mechanisms surveyed here demonstrate that IL-8 operates following orchestrated programs within signaling webs in melanoma, stromal and vascular cells. Importantly, the yet unknown molecularity regulating IL-8 impact on cells of the immune system could be exploited to overturn tumor fate. The molecular and cellular targets of IL-8 should be brought into the attention of even more intense scientific exploration and valorization in the therapeutical management of melanoma.

Study on Surface Quality and Corrosion Resistance of Ultrasonic Vibration Assisted Micromilling Inconel718

Micromilling (MM) is favored by the field of high-precision micro parts. However, the high plasticity of Inconel718 often poses a threat to MM, such as pits, humps and gullies, which affect the surface quality. In this study, the influence of ultrasonic vibration assisted micromilling (UVAMM) on surface quality is comprehensively analyzed by using the machining process of workpiece vibration, combined with cutting force, tool wear, surface morphology and corrosion resistance. The results show that, on the one hand, small amplitude plays a significant role in reducing cutting force and inhibiting tool wear. On the other hand, smaller speed, smaller feed rate and moderate amplitude will produce better surface morphology, which is a uniform and regular fish scale surface with lower surface roughness and fewer surface defects. Furthermore, the application of ultrasonic vibration also significantly improves the surface corrosion resistance of Inconel718. It is worth noting that the surface corrosion resistance does not completely depend on the surface roughness, but also has a close correlation with the surface morphology.