Arrangement Of Bundles Research Articles

Utilization of Advanced Microscopy Techniques and Energy-dispersive X-ray Spectroscopy to Characterize Three Piper Species Related to Kava.

Macro- and microscopic techniques have long been used to describe plant materials and establish plant structural profiles. These techniques are commonly used in botanical authentication to identify the genuine and closely allied species used in botanical research. Advanced microscopic techniques were used in this study to differentiate three different Piper species used as kava or kava-kava. The genuine species is Piper methysticum and the other two species commonly called false-kava or kava-kava, are Piper auritum and Piper excelsum. Macroscopic characteristics, including a black-spotted stem and fibrous root, are characteristic of P. methysticum, whereas the stem of P. auritum is greenish with no spots, and the P. excelsum stem is purple-pink. Microscopic attributes include the characteristic collenchyma of stems and the pattern of arrangement of peripheral and medullary vascular bundles. The starch grains are smaller in P. excelsum than in the other two species. Energy-dispersive X-ray spectroscopy analysis of the crystals indicates the expected calcium, magnesium, and silica, along with lesser amounts of sodium, and potassium. The crystals present in the Piper species vary in shape, size, and elemental composition. Combining macro- and microscopical techniques and resulting characteristics are instrumental in differentiating the three Piper species.

Therapeutic potential of mesenchymal stromal cells on morphological parameters in the hippocampus of rats with brain ischemia-reperfusion modeling

Ischemic stroke is an extremely important pathology with high mortality, in which more than 50 % of patients with occlusion of the main vessels remain disabled, despite early reperfusion therapy by thrombolysis or thrombectomy. As part of the regenerative strategy, stem cell transplantation in ischemic stroke became a new impetus. Cell therapy with the use of mesenchymal stromal cells demonstrated encouraging results regarding endogenous mechanisms of neuroregeneration in response to ischemic damage to brain structures. The aim of the research is to study the influence of mesenchymal stromal cells of various genesis, lysate of mesenchymal stromal cells obtained from Wharton’s jelly umbilical cord and citicoline on the dynamics of morphological changes in the hippocampal CA1 region of rats with acute cerebral ischemia-reperfusion according to light microscopy and micromorphometry data. The experiment was carried out using 200 male Wistar rats, which were subjected to ischemia-reperfusion by reversible 20-minute bilateral occlusion of the internal carotid arteries. Animals with modeled pathology were intravenously transplanted with mesenchymal stromal cells of various genesis (from Wharton’s jelly of the human umbilical cord, human and rat adipose tissue), and rat embryonic fibroblasts, lysate of mesenchymal stromal cells and citicoline were injected. Histological analysis of rat brain sections was performed on the 7th and 14th day of the experiment. Statistical analysis was performed using “Statistica 6.0” (StatSoft® Snc, USA). The significance of differences was assessed using the Student’s t-test and the nonparametric Mann-Whitney U test. During the study, it was found that modeled ischemia-reperfusion in rats caused almost complete degeneration of the structure of the pyramidal layer of hippocampal CA1 region, gave uniformity to the structure of the radiant layer, infiltration of microglia, contributed to the disruption of the arrangement of apical dendrite bundles and narrowing of blood vessels as a result of perivascular edema. Also, the modeled pathology reduced the total number of neuronal nuclei in the hippocampal CA1 area, the overwhelming majority of which had signs of pathological changes. Transplantation of mesenchymal stromal cells of various origins, lysate of mesenchymal stromal cells and citicoline contributed to a significant increase in the number of neuronal nuclei in the hippocampal CA1 zone and nuclei that did not undergo pathological changes. The most positive effect was found in the transplantation of mesenchymal stromal cells from human Wharton’s jelly-derived cells. Thus, both in the subacute and recovery periods of ischemic stroke in rats, the transplantation of human Wharton’s jelly-derived mesenchymal stromal cells was significantly surpassed the reference drug citicoline in its ability to reduce the number of pathologically changed nuclei by 1.5 times (p<0.05). At the same time, the number of pathologically unchanged nuclei significantly exceeded the number of nuclei with signs of karyorrhexis and karyopyknosis, so it would be advisable to use mesenchymal stromal cells of various genesis, lysate or citicoline in conditions of acute cerebral ischemia-reperfusion, taking into account their ability to reduce the volume of the infarct. In the future, an injectable drug will be created from the most effective culture of mesenchymal stromal cells in terms of cerebroprotective properties for cell therapy of patients with acute ischemic stroke.

Morphological and anatomical studies in Nigella sativa L. (Ranunculaceae)

This research delves into the morphological and anatomical intricacies of Nigella sativa L. (Ranunculaceae), commonly known as black cumin, through meticulous examination of various accessions collected from diverse geographical regions in India. Morphological studies revealed distinct characteristics such as the linear to lanceolate alternate leaves, black capsule fruit housing seeds, and growth parameters including germination time, maturation period, and yield per plant. Notably, certain accessions exhibited superior attributes in terms of plant height, root length, and seed yield. Anatomical investigations unveiled detailed structures of stems, roots, seeds, and capsules. Stem anatomy exhibited a multi-cornered structure with specific features like uniseriate epidermis with non-glandular trichomes, parenchymatous cortex with chlorenchymatous and sclerenchymatous cells, and distinct vascular bundle arrangements. Root anatomy depicted a circular cross-section with well-defined layers including epidermis, cortex, and xylem with prominent oil droplets. Seed anatomy displayed layers of epidermis, parenchyma, pigmented layer, endosperm, and a central embryo. Moreover, this study identified novel cells in the stem cortex and observed variability in carpel numbers among different accessions. The findings contribute significantly to the understanding of N. sativa morphology and anatomy, shedding light on previously unexplored aspects and emphasizing the need for further investigation into the variability within and among accessions.

Numerical study on heat transfer characteristics of LBE cross flow tube bundle under rolling conditions

Combined with the neutron economy and good heat transfer performance, lead–bismuth fast reactor (LFR) has a larger prospect for marine applications. Helical coiled once-through tube steam generator (HCOTSG) is also a typical heat exchanger option for LFR. It is widely adopted in a variety of energy utilization fields, such as petrochemical industry. Study on Lead-bismuth eutectic (LBE) cross flow of tube bundle under moving conditions is necessary for obtaining the flow and heat transfer characteristics of LBE HCOTSG in marine conditions. A numerical method to simulate the heat transfer characteristic of LBE cross tube bundle flow under rolling conditions is proposed. The influence of the rolling conditions on the models with different tube arrangements are investigated. The temperature fluctuation curves with time and the time-averaged heat transfer characteristics are compared and analyzed. The results of the influence of rolling conditions under different working conditions and different tube bundle arrangements are obtained. The improvement ratio under inclined arrangement and staggered arrangement is more than 20 %, but the improvement under inline arrangement can only reach 10–15 %. Among the calculated models under different rolling conditions, the maximum heat transfer improvement reached 27.3 %. Besides, the circumferential temperature results under different conditions were also compared to analyze the influence of rolling conditions. This study may contribute to the application of LBE HCOTSG under marine conditions.

Stiffness and stability of bamboo stem- A optimal design perspective

During the evolution process, a bamboo stem achieves a significant height (up to 20 m) to fulfil its phototropic requirements. While on land, the stem is mostly subjected to bending load which makes it liable to fail by uprooting. However, this failure is prohibited by smart structure of bamboo stem which includes graded arrangement of fibre bundles in the cross-section and a tapered cantilever form of the stem. This paper attempts to understand the optimal design of bamboo stem through the relationship between the stellar arrangement of stiff fibre bundles in the cross-section and the tapered form. In this work, a comparison between two types of stellar arrangement, namely uniform and graded, is presented in view of non-linear bending analysis through elastica theory and fracture-induced delamination, both numerically. It is observed from the results that a bamboo stem prefers to evolve with graded stellar arrangement which provides gradation of stiffness and toughness over the cross-section; the trend in toughness being opposite to that of stiffness. Moreover, interplay of stellar arrangement and gradation of stiffness-toughness thereof is found to be the governing mechanism for ensuring its mechanical integrity and stability in view of an optimal design perspective. The smart structure of bamboo is recommended for bio-mimicking.

Thermo Structural Analysis of Biomass Combustion Steam Generation Heat Exchangers Using Three Dimensional Numerical Modelling

Biomass with all its positive characteristics contains some elements and compounds that react negatively with stainless which are known for its usage in high temperature, corrosive prone and, hash environment. Therefore, it is pertinent to comparatively study the strength of various corrosive resistance metals to be able to have an alternative to stainless steel. The purpose of this study is to model and simulate a three-dimensional steam generating boiler plant heat exchanger for a biomass firing process. In the study, inlet temperature and operating temperature of shell and tube sides are taken as input parameters with a square pitch bundle arrangement. The heat transfer analysis is done by considering hot flue gas inside the tubes and steam on shell side to determine the thermal stress, strain and deformation distributions in the tubes and shell of the heat exchanger. The study also presented time-history analysis of the both shell and tubes to ascertain the material reactions within the specified time range. The comparison of deformations and the equivalent strain rate between the two designs indicated an excellent performance of the AL6XN over the 306L stainless steel. The strain amplitude for PMX110 and WKX110 sequentially dropped from 903 to 496 and 621 to 332 between the temperature range of 100 – 10000C respectively. The maximal equivalent strain values for the shells and tubes were 2.238e-003 and 1.294e-004 for PMX110 and 1.490e-003 and 3.212e-004 for WKX110 respectively. The highest deformation in both PMX110 and WKX110 were estimated as 6.729e-004 and 6.131e-004 for the shells and 1.441e-004 and 1.328e-004 for tubes respectively.

Experimental Permeability and Porosity Determination of All-Oxide Ceramic Matrix Composite Material.

This paper presents an investigation into the water permeability of an all-oxide ceramic matrix composite. To determine the parameters and characterize the water permeability of the ceramic composite material, an experimental study was carried out in which a dedicated test rig was constructed and commissioned. A total of five different configurations of composite tubes were tested. They differed in fibre roving strength, winding angle, fibre bundle arrangement during winding, and matrix grain size distribution. To better understand the internal structure of the analysed ceramic matrix composite material, the experimental study used scanning electron microscopy for microstructure and porosity observation. The tested tubes will be used as liners in an oxy-combustion chamber in future studies. The experiments obtained new and interesting results regarding the water permeability of the ceramic matrix composite with different structural parameters. It was also observed that, as with some porous materials, the permeability of ceramic matrix composites decreases with time as more and more liquid is pressed through it.

A Modeling Approach to Studying the Influence of Grafting on the Anatomical Features and SAUR Gene Expression in Watermelons

Grafting alters the genetic and anatomical features of plants. Although grafting has been widely applied in plant propagation, the underlying processes that govern the effects of the procedure are not fully understood. Samples were collected to study the long-term influence of grafting on the leaf-shoot morphology, leaf-shoot anatomy, and genetic signature of the grafted plants. Citrulus lanatus (Thunb.) Matsum. & Nakai (cv. Lady) was used as the scion, and Lagenaria siceraria (Molina) Standl (cv. Argentario) as a rootstock. In grafted plants, leaf blades and petioles were 20.92% and 12.82% longer, respectively, while the midrib collenchyma was 35.68% thicker, and the diameter of the vessel member was 11.17% larger than in ungrafted plants. In the stem, grafting affected the arrangement and number of vascular bundles (from 1 to 2 rings). The thickness of the epidermis decreased by 69.79%, and the size of the external fascicular phloem decreased by 23.56%. The diameter of the vessel member of the grafted plants increased by 28.94%. Eight out of ten evaluated primers met the requirements (stability in both watermelons and bottle gourd, tissue-specific). In the genetic tests, we examined whether this change in the gene expression pattern is due to the grafting and, if so, to what extent. Seven out of eight tested Small Auxin Up-Regulated RNA (SAUR) genes were expressed in the ungrafted and grafted C. lanatus lines in four cases; the expression increased by more than 10% after grafting. The morpho-anatomical changes and genetic variation reported in this study for grafted lines of C. lanatus contribute to the understanding of the underlying mechanisms of plant growth observations resulting from grafting.

MITOCHONDRIAL DYSFUNCTION IN THE PATHOMORPHOGENESIS OF HYPERTROPHIC CARDIOMYOPATHY

The pathomorphogenesis of hypertrophic cardiomyopathy is a disruption of the arrangement of bundles of muscle cells in the myocardium and is associated with mutations in genes encoding the synthesis of myocardial contractile proteins. Metabolic changes in this pathology are caused by hypertrophy of the interventricular septum due to disruption of the myocardial contractile apparatus associated with these mutations, as well as mitochondrial dysfunction. Mutations in myofiber proteins can negatively affect mitochondria through increased oxidative stress due to increased ATP demand. Mitochondria are complex organelles with their own circular DNA, as well as the presence of enzyme complexes involved in redox reactions, which causes frequent damage to mitochondrial protein structures and membranes by reactive oxygen species. In this regard, mitochondrial dysfunction can also be caused by mutations in genes encoding mitochondrial proteins, which leads to disruption of mitophagy and mitochondrial dynamics. The functioning of defective mitochondria is associated with insufficient ATP synthesis and ineffective muscle contraction, which leads to the same consequences at the tissue level as mutations in contractile protein genes. In this review, we tried to summarize the role of mitochondrial dysfunction in the pathomorphogenesis of hypertrophic cardiomyopathy.

Study of fluid-elastic instability of the spatially bent tube structure in fast reactor intermediate heat exchanger

This study conducts a numerical simulation investigation on the flow field characteristics and fluid-elastic instability of the spatially bent tube structure in the intermediate heat exchanger (IHX) of a fast reactor. The inherent frequencies of the unique structure of the IHX spatially bent tube are calculated by using the wet modal method. They are employing Computational Fluid Dynamics (CFD) in conjunction with a fluid-structure coupling model, establishing an elastic tube model. Considering the bundle concentric circles arrangement, the “transition” arrangement is selected as the model to simulate the fluid-elastic instability. By the analysis of critical flow velocity, displacement, and the main vibration direction, the results indicate that the fluid-elastic instability of the tube bundle with a transition arrangement is mainly manifested by more severe vibrations in the bent tube segment. The instability flow velocity in the straight tube segment, ranging from 4.64 to 4.84 m/s, is greater than the instability flow velocity of 2.85 m/s in the bent tube segment. This study provides theoretical support for the design and operation of the intermediate heat exchanger in fast reactors, offering references for considering tube bundle arrangement and fluid-elastic instability in engineering practice.

Biomechanical functions analysis of the Mallard webbed foot: A study of macroscopic and microscopic material assembly and tendon morphology

The mallard webbed foot represents an exemplary model of biomechanical efficiency in avian locomotion. This study delves into the intricate material assembly and tendon morphology of the mallard webbed foot, employing both macroscopic and microscopic analyses. Through histological slices and scanning electron microscopy (SEM), we scrutinized the coupling assembly of rigid and flexible materials such as skin, tendon, and bone, while elucidating the biomechanical functions of tendons across various segments of the tarsometatarsophalangeal joint (TMTPJ). The histological examination unveiled a complex structural hierarchy extending from the external integument to the skeletal framework. Notably, the bone architecture, characterized by compact bone and honeycombed trabeculae, showcases a harmonious blend of strength and lightweight design. Tendons, traversing the phalangeal periphery, surrounded by elastic fibers, collagen fibers, and fat tissue. Fat chambers beneath the phalanx, filled with adipocytes, provide effective buffering, enabling the phalanx to withstand gravity, provide support, and facilitate locomotion. Furthermore, SEM analysis provided insights into the intricate morphology and arrangement of collagen fiber bundles within tendons. Flexor tendons in proximal and middle TMTPJ segments adopt a wavy-type, facilitating energy storage and release during weight-bearing activities. In contrast, distal TMTPJ flexor tendons assume a linear-type, emphasizing force transmission across phalangeal interfaces. Similarly, extensor tendons demonstrate segment-specific arrangements tailored to their respective biomechanical roles, with wavy-type in proximal and distal segments for energy modulation and linear-type in middle segments for enhanced force transmission and tear resistance. Overall, our findings offer a comprehensive understanding of the mallard webbed foot's biomechanical prowess, underscoring the symbiotic relationship between material composition, tendon morphology, and locomotor functionality. This study not only enriches our knowledge of avian biomechanics but also provides valuable insights for biomimetic design and tissue engineering endeavors.

Numerical investigation and comparison on thermal-hydraulic performance of H-type finned tube heat exchanger

H-type finned tube heat exchangers have been widely used in boilers and waste heat recovery devices due to their advantages of wear resistance and anti-fouling. In order to improve the energy-saving effect, the flow and heat transfer characteristics of H-type finned tube heat exchangers with different tube bundle arrangements were studied. It was found that, at the same Re number, the column staggered arrangement can compensate for the limited heat transfer performance of the in-line arrangement and reduce the high pressure drop associated with the row staggered arrangement. Honeycomb arrangement was proposed based on the column staggered arrangement. Then, the effects of Re and tube pitches thermal-hydraulic performance of tube bundles with in-line and honeycomb arrangements were examined. The critical tube pitch or velocity at which the honeycomb tube bundle achieves the same thermal performance as the in-line tube bundle are determined. The results provide valuable insights for the practical application of flue gas heat exchangers with honeycomb arrangement.

Panxianopteris taeniopteroides gen. et sp. nov., an anatomically preserved taeniopterid leaf from the upper Permian of Guizhou Province, China

Taeniopterid leaves with entire margins, prominent midribs and simple or bifurcate lateral veins are present in many Paleozoic and Mesozoic floras globally and were a typical and diverse element in the late Paleozoic equatorial Cathaysian flora. Most taeniopterid leaves are preserved as impression-compression fossils that reveal only information on their morphology and in some cases cuticle structure. Taeniopterid leaves preserved with anatomy are much rarer and have only previously been identified in the Mesozoic. Here we report a taeniopterid leaf from the upper Permian Xuanwei Formation in southwestern China that preserves morphology and anatomy. The leaf is over 18 cm long and 10 cm wide, with the lamina attached to the lateral sides of the midrib. Parallel lateral veins arise from the midrib which has longitudinal ridges on its adaxial surface and two distinct groups of vascular bundles. One group of bundles is adaxially located and arranged in a rough inverted Ω-shape, while the other is abaxially located and arranged in a ring. Individual bundles have endarch primary xylem and secondary xylem. Comparisons with other anatomically preserved taeniopterid leaves allow us to establish Panxianopteris taeniopteroides gen. et sp. nov. This vascular bundle arrangement is most comparable to the rachis of the Triassic Umkomasiales pteridosperm leaf Dicroidium fremouwensis from the Gondwanan flora. P. taeniopteroides is the first anatomically preserved taeniopterid leaf reported from the Paleozoic and the Cathaysian flora, and although its affinity remains enigmatic because it is only known from its isolated leaf, it is likely to be a pteridosperm allied with the Umkomasiales or their ancestral lineage.

Assessment of Density and Anatomical Features of Young and Old Bambusa vulgaris (Schrad. ex J.C. Wendl.) Culm Heights as Sustainable Structural Material in Ghana

This study sought to assess the density and anatomical features of young and old Bambusa vulgaris Schrad. ex JC Wendl. culm heights and, therefore, evaluate their influence on the utilization potential of the culm as a sustainable structural material. Bambusa vulgaris culm of 2-year and 4-year-old were harvested and prepared to the required length of 6 meters for the study. Basic density and anatomical features were carried out. The results showed that the basic density of old bamboo ranges from 652.91 kg/m³ to 729.06 kg/m³, while the young bamboo ranges from 342.33 kg/m³ to 509.52 kg/m³. The vascular bundle arrangement was found to be in Type III and Type IV for the culm heights of both young and old bamboo. The average vascular bundle radial diameter ranged from 761.13 μm to 890.78 μm for the old culm and 727.16 μm to 844.83 μm for the young culm. The average vascular bundle tangential diameter ranged from 499.44 μm to 533.49 μm for the old culm and 425.56 μm to 483.56 μm for the young culm. The radial diameter of the metaxylem vessel of the old culm ranged from 216.81 μm to 54.74 μm, while 214.23 μm to 73.86 μm were for the young culm. Parenchyma tissues ranged from 35%– to 70% for the old bamboo culm and 45% to 75% for the young bamboo culm. Vessel proportion ranged from 6%–12% for the old culm while the young culm ranged from 5%–11%. Fiber proportion ranged from 22% to 54% for the old culm and 19% to 44% for the young culm. Old bamboo had better vascular bundle properties than that of young bamboo. The density is significantly correlated positively to the anatomical properties. Old bamboo is more suitable to be used as the engineered composite material due to its better anatomical features across the culm wall thickness.

Anatomy of leaf blade, leaf sheath and pseudopetiole in Neotropical Bambusoideae (Poaceae): Insights into structure and taxonomic contributions

Anatomical investigations aiming to seek alternative characters for the taxonomy of bamboos are almost exclusively restricted to the leaf blade. Little is known about the anatomical structure of other parts of the leaf, such as the leaf sheath and pseudopetiole. The present paper analyzed the complete structure of foliage leaves, including the foliage leaf blade, foliage leaf sheath, and pseudopetiole of species belonging to the tribes Bambuseae (subtribes Guaduinae, Chusqueinae and Arthrostylidiinae) and Olyreae (subtribe Parianinae) to identify useful characters in the taxonomy of bamboos. We used scanning electron microscopy and light microscopy to describe micromorphological and anatomical features. All species sampled share the following features: foliage leaf blades with uniseriate epidermis; adaxial bulliform cells; mesophyll with arm cells, cavities, and collateral vascular bundles. Intercostal sclerenchyma associated to bulliform cells was observed only in Arthrostylidiinae. Micromorphologically, the shape and distribution of silica bodies, presence, type, and distribution of papillae on the long cells and subsidiary cells, and the presence and distribution of trichomes may be taxonomically informative in different taxonomic levels. We highlight the absence of papillae on the surfaces of foliage leaf blade of Guaduinae since the presence of papillae is considered a putative diagnosis feature supporting the sister relationship of this subtribe with Arthrostylidiinae. We describe the anatomical structure of foliage leaf sheath for the first time for Guaduinae, Chusqueinae and Parianinae. In Guaduinae, we found a unique distribution pattern of silica cells on the abaxial surface of the leaf sheath. Anatomical data about the pseudopetiole structure also were described for the first time in bamboos species; the arrangement of vascular bundles may be taxonomically informative, especially in Guaduinae.

Constructive development and design justification of the protective shell of a nuclear reactor made of reinforced concrete

Introduction. This paper provides materials justifying the introduction of a new constructive solution for the reinforced concrete protective shell of a nuclear reactor in a prefabricated and monolithic design.
 
 Aim. Among the tasks that were set during the development of the constructive solution, the main one was to ensure the work of reinforced concrete for compression under all types of loading and the perception of tensile forces by ropes that are in a free state, available for maintenance and operation.
 
 Materials and methods. The calculations were performed by the finite element method using a software package MicroFe-StaDiCon for calculation of the spatial structures for strength, stability and vibrations.
 
 Results. A fundamentally new constructive solution has been developed for the protective shell of the nuclear reactor of the NPP, consisting of reinforced concrete elements in the form of cylindrical folds with a bulge directed towards possible external and internal force emergency effects, including the explosion of the reactor. Variants of protective shells have been developed with the elaboration of fundamental technical solutions for unified folded elements made of reinforced concrete with the possibility of their monolithic and prefabricated manufacture. A scheme of open arrangement and tensioning of cable bundles with tension transfer to pre-fabricated structures of the inner and outer parts of the protective shell is proposed.
 
 Conclusions. This design solution provides compressive forces in reinforced concrete of the folds of the inner and outer parts of the protective shell from the load during loading, which prevents the formation of cracks in them. The tensile forces in the shell are perceived by the prestressed reinforcement located inside its structure, free for maintenance and control. In the process of work, fundamental solutions have been developed for the structural nodal joints of prefabricated folded reinforced concrete elements, technological holes in the shell structure and the implementation of prestressing in it. A comparative technical and economic analysis of the proposed and existing inner protective shell showed the possibility of reducing concrete consumption by 1.5–2 times, non-stressed reinforcement by 3–4 times, construction time by 4 times.

Seismic responses of a fuel assembly in nuclear heating reactor

The fuel assembly (FA) stands as a pivotal component within nuclear reactors, impacting safety, reliability, and economic viability of the entire facility. In the 200 MW nuclear heating reactor (NHR200-II), the FA embodies a novel structural configuration, characterized by a 9 × 9 fuel bundle arrangement enclosed within a singular channel. During seismic events, challenges like potential FA damage and control rod insertion failures can pose safety risks. Therefore, a comprehensive structural integrity assessment is essential. The seismic responses of the NHR200-II FA unidirectionally and bidirectionally under different boundary conditions, using a time-compressed El-Centro N-S earthquake (1.5 times amplification, ∼0.36 g peak acceleration), are analyzed in detail. We examine stress distribution, channel-spacer grid interactions, dynamic clamping, acceleration responses, and response spectra. Results confirm the robust seismic performance of NHR200-II FA, with potential for future seismic fluid–structure interaction analysis based on the model used in this work.

Features of the spatial orientation of the thoracodorsal nerve bundles

BACKGROUND: Studying the spatial arrangement of nerve bundles makes it possible to better understand the characteristics of the occurrence and mechanisms of injuries to peripheral nerves, to develop and perform new reconstructive operations.
 AIM: To identify the features of the route, spatial orientation and relationships of the thoracodorsal nerve bundles along its entire length.
 MATERIAL AND METHODS: Intrastem dissection of 121 thoracodorsal nerves was performed in the corpses of men and women aged 40–97 years. The obtained indicators of the length (mm) and angles of deviation (degrees) of the thoracodorsal nerve bundles at different levels of their entire path were checked for normality of distribution using the Shapiro–Wilk test. When describing the studied indicators, the median (Me) and quartile intervals (Q1, Q3) were determined, and the significance of intergroup differences was determined using the Mann–Whitney U test.
 RESULTS: Along the entire path, the bundles of the thoracodorsal nerve change their spatial position 6 times and their relationship with each other 1 time. The closer the bundles are to the spinal cord and spine, the more changes (85.7%); the further to the periphery, the fewer (14.3%). The bundles of the thoracodorsal nerve are located twice in the horizontal plane, and in the proximal half of the C7 spinal nerve they are twisted relative to each other by 180° [170°; 190°], change places: the sensory ones move from the posterior position to the anterior one, and the motor one — from the anterior to the posterior one. The bundles of the thoracodorsal nerve deviate downward 4 times in the frontal plane at a total angle of 105° [95°; 115°], and in the sagittal plane they change their position 2 times and move from an oblique-anterior (15° [5°; 25°]) to an oblique-posterior (20° [10°; 30°]) position.
 CONCLUSION: The route of passage of the thoracodorsal nerve bundles along the entire path from the spinal cord to the latissimus dorsi muscle consists of eight levels of different lengths, 6 times they change their spatial orientation and 1 time their relationship with each other.

Numerical simulation of thermal hydraulics of supercritical pressure water with 2×2 rod assembly wrapped differently with a wire

Through the use of CFD, a thermal-hydraulic analysis was carried out on a set of 4 rod assemblies. The common wire-wrapped spacers on the fuel assemblies are wound in the same direction for all rods. Because of this design, it is anticipated that there would be an adverse flow in all of the sub-channels. In the course of this analysis, this flow was demonstrated to be real. In order to achieve desirable flow characteristics for coolant mixing, a novel configuration for wire-wrapped spacers is proposed here. This pattern designates a group of 4 rods, the rods have the wrapping system of clockwise and anticlockwise pattern. It was determined that this pattern had an exceptional mixing effect as well as a uniform flow. This pattern has a maximum temperature area that is approximately 8.5 °C lower than that of the conventional wire-wrapped fuel bundle arrangement. When compared to the regular pattern, the pressure drop caused by the new arrangement was approximately 1.9% less severe. The redesigned layout of the rod assembly improves heat transfer while also reducing the amount of pressure loss that occurs.

A novel approach for the optimal arrangement of tube bundles in a 1000-MW condenser

A novel approach for the optimal arrangement of tube bundles in a 1000-MW condenser