Longitudinal Division Research Articles

Comparison of Two Surgical Techniques Based on the Semitendinosus Myocutaneous Flap in Cats.

The objective of this experimental study was to compare the semitendinosus (ST) to the split-semitendinosus (SST) myocutaneous flap in covering distal limb skin defects in cats. Twenty-eight purpose-bred laboratory DSH cats were used and allocated into two groups (ST-group (A); n = 14, SST-group (B); n = 14). ST flaps, based on the distal muscle pedicle, and SST flaps, after longitudinal division of the muscle based on both muscle pedicles, were tested over skin defects created on the medial distal tibia. Clinical assessment, planimetry, CT-angiography (CTA) and histological examination were compared between groups. Days to complete flap healing between ST and SST-flaps (30.36 ± 9.1, 32.29 ± 5.44, respectively) and final total flap areas (68.36% ± 27.18, 51.83% ± 22.48, respectively) revealed no significant differences. On CTAs, the caliber of the distal caudal femoral vein on day 10 was statistically significant higher (p < 0.001) for group A and a significantly higher caliber of the distal caudal femoral artery on day 30 for group B (p = 0.021). Histology revealed statistically higher degeneration at 6 months (p = 0.047) for group A, and statistically higher fibrosis at 12 months (p = 0.019) for group B. Both ST and SST flaps had similar healing times and provided coverage of skin tibial defects in cats.

Ayurvedic management of Carpal Tunnel Syndrome with Agnikarma – A Case Report

Carpal tunnel syndrome is an entrapment neuropathy caused by compression of median nerve as it passes through the carpal tunnel i.e., the space between the carpal bones posteriorly and the flexor retinaculum anteriorly. The compression can be caused by skeletal abnormalities, swelling of other tissues within the tunnel or thickness of the retinaculum. The condition is common in middle aged women at the menopause. In younger patients the cause may be rheumatoid disease, pregnancy or tenosynovitis. It is a condition that causes pain, numbness, tingling, and weakness in the hand and wrist. Carpal tunnel syndrome has fast growing annual incidence rate of 5 to 50 per Ten thousand populations. Modern treatment for this condition includes injecting hydrocortisone into flexor sheaths at the carpal tunnel, wearing cock-up splint and longitudinal division of the flexor retinaculum. On the basis of structures involved and features of carpal tunnel syndrome this condition can be correlated with Snayugata Vata Vikara which affects tendons ligaments and nerve. Sushruta has advised Agnikarma for disorders of snayu (ligaments and tendons), asthi (bone), siddhi (joints) etc. Hence, in this study a case of carpel tunnel syndrome (snayugatavata) was treated by Agnikarma, along with administration of Navajivana Rasa orally, for a period of 04 weeks. This combination therapy provided considerable relief in pain and tingling sensation of wrist.&#x0D;

Holistic approach to the Neuromusculo Diseases related to Spinal Cord and Vertebral Column

The spinal cord is a complex organization of nerve cells responsible for movement and sensation. It carries signals between the brain and the rest of the body. Spinal cord injuries can range from sensory loss to incomplete or complete paralysis. Spinal cord diseases are a heterogeneous group of conditions that cause damage or dysfunction of the spinal cord. They include infections, inflammatory disorders, vascular diseases and disorders that affect the meninges or perimeningeal spaces that surround the spinal cord. Motor, sensory, reflex, and sphincter abnormalities may be used to determine the location of a lesion within one of four major longitudinal divisions of the spinal cord. The divisions are cervical (C1–C5 spinal cord segments), cervical enlargement (C6–T2), thoracolumbar (T3–L3), and lumbar enlargement (L4–Cd5). A disorder of each of the four regions of the spinal cord results in a combination of neurological signs that is specific for the region involved. Recognition of a characteristic group of clinical signs therefore allows accurate localization of a spinal cord lesion. Spinal Cord disorders are conditions that cause damage and deterioration to the spinal cord. These conditions include Spinal stenosis, Herniated Discs, Degenerative disc disease etc. Symptoms of Spinal Cord Disorders are weakness or paralysis of limbs, loss of sensation, uncontrolled muscle spasms and back pain etc. Having knowledge of the location and structure of the protective spinal cord can help healthcare professionals to provide pain relief for certain procedures.

Unsuspected findings about phylogeny and ultrastructure of the enigmatic cyanobacterium Microcrocis geminata resulted in its epitypification and novel placement in Geminocystaceae

The genus <i>Microcrocis</i> belongs to long ago established cyanobacterial taxa for which relevant data required for a modern taxonomic analysis remained unknown for a long time. In present study we proposed an epitype originating from a large natural population of the type species <i>M. geminata</i>. Through isolating clean individual colonies from the environmental sample, sufficient material for a single colony PCR and amplification of genomic DNA by MDA method was obtained. Molecular analyses of the 16S rRNA gene determined the unsuspected position of the cyanobacterium within the family Geminocystaceae, forming a distinct branch with two <i>Merismopedia</i> sequences. 16S rRNA and ITS analysis clearly separated the two taxa on generic level. The phylogenetic classification is conspicuously consistent with the ultrastructure of parallel thylakoids unique for some members of the family Geminocystaceae. Distinctive morphology of the genus including typical longitudinal division is discussed.

Impact of combined component separation technique and shoelace repair on big medline abdominal wall defect

BackgroundClosure of large anterior abdominal wall defects, regardless of their etiology, is challenging. There is no standardized information describing definitive management. Therefore, we conducted this study to illustrate our experience on large midline abdominal wall defect repair using an effective modified reconstructive technique. MethodsThis retrospective study was conducted at Al Naqib Hospital in Aden/Yemen between 2012 and 2019. Twenty-six patients with large midline abdominal wall defects of various etiologies underwent surgical repair using a combination of shoelace repair and the component separation technique. The procedure involved bilateral longitudinal division of the anterior rectus sheet and creation of a posterior layer by approximation of the medial edges of the divided rectus sheet (shoelace abdominoplasty) and anterior external oblique muscle aponeurosis separation (component separation technique) to approximate the lateral edges of the divided rectus sheet and move the rectus muscles toward the midline for constructing the anterior abdominal wall layer. The posterior and anterior layers and bilateral separated sheets were covered with a polypropylene mesh in all patients, except in those who underwent emergency damage control surgery. ResultsFour, one, and two patients developed seroma, skin necrosis and chronic pain, and post-surgical wound infection, respectively. No recurrent herniation was recorded during the median follow-up of 5 years. ConclusionThis technique is effective in restoring the integrity of the abdominal wall in large midline abdominal wall defects and has an acceptable aesthetic appearance. In our study, minimal complications were reported, and no cases of recurrent hernias were diagnosed during follow-up.

Evolution of longitudinal division in multicellular bacteria of the Neisseriaceae family

Rod-shaped bacteria typically elongate and divide by transverse fission. However, several bacterial species can form rod-shaped cells that divide longitudinally. Here, we study the evolution of cell shape and division mode within the family Neisseriaceae, which includes Gram-negative coccoid and rod-shaped species. In particular, bacteria of the genera Alysiella, Simonsiella and Conchiformibius, which can be found in the oral cavity of mammals, are multicellular and divide longitudinally. We use comparative genomics and ultrastructural microscopy to infer that longitudinal division within Neisseriaceae evolved from a rod-shaped ancestor. In multicellular longitudinally-dividing species, neighbouring cells within multicellular filaments are attached by their lateral peptidoglycan. In these bacteria, peptidoglycan insertion does not appear concentric, i.e. from the cell periphery to its centre, but as a medial sheet guillotining each cell. Finally, we identify genes and alleles associated with multicellularity and longitudinal division, including the acquisition of amidase-encoding gene amiC2, and amino acid changes in proteins including MreB and FtsA. Introduction of amiC2 and allelic substitution of mreB in a rod-shaped species that divides by transverse fission results in shorter cells with longer septa. Our work sheds light on the evolution of multicellularity and longitudinal division in bacteria, and suggests that members of the Neisseriaceae family may be good models to study these processes due to their morphological plasticity and genetic tractability.

Efficacy of a “provisional incision” for longitudinal flap division after free-flap surgery

SummaryFix and flap surgery for severe open limb fractures is already a standard treatment. In cases where the fracture is complicated or accompanied by bone defects, secondary surgery is required for fracture sites covered with a myocutaneous flap after the soft tissue condition has stabilized. We applied the delayed procedure concept used for distant flaps and attempted to prevent postoperative myocutaneous flap necrosis by performing a provisional incision prior to the longitudinal incision of the flap. We report the course of five cases of the longitudinal division of the myocutaneous flap using “provisional incision” after free-flap surgery for severe open fracture and verify its usefulness. In this case series, five patients with severe open limb fractures treated from 2020 to 2021 who underwent longitudinal incision of the myocutaneous flap using provisional incision after free-flap surgery were included. The types of flaps used for soft tissue reconstruction in the acute phase, the reasons for the need for secondary surgery, the period from soft tissue reconstruction to additional surgery, and the healing status of soft tissue after secondary surgery were all investigated retrospectively. The types of flaps used for soft tissue reconstruction were latissimus dorsi myocutaneous flap in four cases and anterolateral thigh flap in one case. The breakdown of secondary surgery was osteosynthesis in one case, plate removal in one case, and bone cement removal and autologous bone grafting in three cases. The period from soft tissue reconstruction to secondary surgery ranged from 6 weeks to 4 months. In all cases, the wound healed without necrosis of the myocutaneous flap. For the treatment of severe open limb fractures, longitudinal division of the myocutaneous flap using “provisional incision” is a safer approach to the necessary secondary surgery and reduces the possibility of necrosis of the flap.

Relief and geological structure of Vyzhnytskyi and Cheremoskyi national natural parks (Ukrainian Carpathians)

Purpose. Analysis of the relief and geological structure of Vyzhnytskyi and Cheremoskyi national natural parks (NNP) as important components of natural complexes, which, as well as biota, are objects of nature conservation institutions. Methods. Field research, geological-tectonic and general geomorphological analysis of the NNP’s relief, review of regional descriptive materials and maps. Results. Vyzhnytskyi NNP and Cheremoskyi NNP are located in the South-Eastern part of the Ukrainian Carpathians within the Chernivtsi region. The analysis of the morphostructure and morphosculpture of NNPs is carried out taking into account the longitudinal (N-W – S-E) and transverse divisions of the Ukrainian Carpathians. The longitudinal division is associated with morphostructures of higher orders, such as second and third, and the transverse is associated with fourth and fifth orders of morphostructure. The analysis of morphosculpture of NNPs shows the types characteresed the Carpathian Flysch and Сrystalline Carpathians. Mountain ranges and ridges such as Bukovyna med-mountains, Pneve-Yarovytsi and part of Chyvchyn mountains are characterized by an asymmetrical structure – steep northeastern slopes and declivous southwestern slopes. The relic morphosculpture is represented by: 1) fragments of denudation surfaces of different ages such as Polonynska and Pidpolonynska within Cheremoskyi NNP as well as Karmaturska (analogue of Pidbeskid) within Vyzhnytskyi NNP; 2) extra glacial landforms within Cheremoskyi NPP; 3) areas of ancient longitudinal valleys. The inherited morphosculpture is represented by river valleys with a complex of terraces of different ages. The premountain part of Vyzhnytskyi NNP includes the relict ("dead") morphostructure of Bagno river valley. Modern morphodynamic processes represent a height (tier) differentiation. The highest tier of apical surfaces in the subalpine zone (1,450–1,600 m) of Cheremoskyi NNP is characterized by processes of slow displacement of debris and manifestations of gravitational, avalanche and nival processes. In the tiers of strongly dissected mеd-mountain and low-mountain relief of NNPs, the processes of planar erosion, deflux, and linear erosion play an important role in the modelling of the relief. The lower tier of the terraced and non-terraced bottoms of the valleys are associated with the processes of leaching and erosion as well as a significant accumulation of erosion products and mudflows. Among gravitational processes and block motions, stabilized and active displacements are the most recorded. Conclusions. In general, the territories of Vyzhnytskyi NNP and Cheremoskyi NNP fully represents the features of geological structure and relief of the south-eastern part of the Ukrainian Carpathians. In conjunction they form a fairly transverse conservation profile of the region from the premountain uplands to the highest ridges of the Marmarosy (Crystal) Carpathians.

나도 풍란을 이용한 속간 교잡종의 수정 및 배형성과 종자 발달에 대한 연구

On 5-7 days after artificial pollination using NadoPungRan(Phalenopsis japonica), native orchid in Korea, pollen were germinated in sticky stigma and pollen tube elongation in style were observed. on 14 days after pollination. In this period, ovule primodia appeared to round pronunciation shape. But filament shape and Megaspore Mother Cell were appeared on 34 days after pollination. Ovule which is ready fertilization, was matured in 40-50 days after pollination. In these time, pollen tube elongation were continued and entirely surrounded ovule sac. On 54-64 days after pollination, pollen tube penetrated to ovule sac and fertilization were completed. After fertilization, zygote was divided to two cell in longitudinal division and upper small cell was developed into proembryo and bottom large cell divided two cell which make suspensor cell. On 110 days after pollination, matured embryo and suspensor which have 16 filament leg, were observed and seed were matured on about 140 days after pollination. To breed intergeneric hybrids between NadoPungRan and Moth orchid, pods were collected in week after pollination and seed germination using artificial medium were tried. Young ovules before 56 days after pollination were not germinated. Ovules on 69 days after pollination were good for germination and to get hybrids.

나도 풍란을 이용한 속간 교잡종의 수정 및 배형성과 종자 발달에 대한 연구

On 5-7 days after artificial pollination using NadoPungRan(Phalenopsis japonica), native orchid in Korea, pollen were germinated in sticky stigma and pollen tube elongation in style were observed. on 14 days after pollination. In this period, ovule primodia appeared to round pronunciation shape. But filament shape and Megaspore Mother Cell were appeared on 34 days after pollination. Ovule which is ready fertilization, was matured in 40-50 days after pollination. In these time, pollen tube elongation were continued and entirely surrounded ovule sac. On 54-64 days after pollination, pollen tube penetrated to ovule sac and fertilization were completed. After fertilization, zygote was divided to two cell in longitudinal division and upper small cell was developed into proembryo and bottom large cell divided two cell which make suspensor cell. On 110 days after pollination, matured embryo and suspensor which have 16 filament leg, were observed and seed were matured on about 140 days after pollination. To breed intergeneric hybrids between NadoPungRan and Moth orchid, pods were collected in week after pollination and seed germination using artificial medium were tried. Young ovules before 56 days after pollination were not germinated. Ovules on 69 days after pollination were good for germination and to get hybrids.

나도 풍란을 이용한 속간 교잡종의 수정 및 배형성과 종자 발달에 대한 연구

On 5-7 days after artificial pollination using NadoPungRan(Phalenopsis japonica), native orchid in Korea, pollen were germinated in sticky stigma and pollen tube elongation in style were observed. on 14 days after pollination. In this period, ovule primodia appeared to round pronunciation shape. But filament shape and Megaspore Mother Cell were appeared on 34 days after pollination. Ovule which is ready fertilization, was matured in 40-50 days after pollination. In these time, pollen tube elongation were continued and entirely surrounded ovule sac. On 54-64 days after pollination, pollen tube penetrated to ovule sac and fertilization were completed. After fertilization, zygote was divided to two cell in longitudinal division and upper small cell was developed into proembryo and bottom large cell divided two cell which make suspensor cell. On 110 days after pollination, matured embryo and suspensor which have 16 filament leg, were observed and seed were matured on about 140 days after pollination. To breed intergeneric hybrids between NadoPungRan and Moth orchid, pods were collected in week after pollination and seed germination using artificial medium were tried. Young ovules before 56 days after pollination were not germinated. Ovules on 69 days after pollination were good for germination and to get hybrids.

RELIEF AND GEOLOGICAL STRUCTURE OF HUTSULSHCHYNA AND VERKHOVYNSKYI NATIONAL NATURAL PARKS

Relief and geological structure of Hutsulshchyna and Verkhovynskyi national natural parks (NNP), located in the south-eastern part of the Ukrainian Carpathians, present four geomorphological regions of the Ukrainian Carpathians. Hutsulshchyna NNP is located in Skybovi Carpathians and Precarpathian Upland. Verkhovynskyi NNP is located in Marmaroski Carpathians and Polonynsko-Chornohirski Carpathians. The analysis of the morphostructure and morphosculpture of national natural parks is carried out taking into account the longitudinal (N-W – S-E) and transverse divisions of the Ukrainian Carpathians. The longitudinal division is associated with morphostructures of higher orders, such as the second and third, and the transverse is associated with the fourth and fifth orders of morphostructure. In the analysis of morphosculpture of NNPs, the types which are characteristic of the Carpathian Flysch and Сrystalline Carpathians are allocated. Mountain ranges and ridges such as Sloboda-Rungurska, Pokuttia med-mountains, Hryniava-Losova and Chyvchyn mountains are characterized by an asymmetrical structure – steep northeastern slopes and declivous southwestern slopes. The relic morphosculpture is represented by: 1) fragments of denudation surfaces of different ages such as Polonynska within Verkhovynskyi NPP as well as Karmaturska (analogue of Pidbeskid) within Hutsulshchyna NPP, and riparian; 2) extra and ancient glacial within Verkhovynskyi NPP and extra glacial within Hutsulshchyna NPP; 3) areas of ancient longitudinal valleys. The presence of relict ("dead") river valleys is characteristic of the premountain part of Hutsulshchyna NNP. Modern morphodynamic processes represent by height (tier) differentiation. In the tiers of strongly dissected mеd-mountain and low-mountain relief, the processes of planar erosion, deflux, and linear erosion play an important role in the modelling of the relief. The lower tier of the terraced and non-terraced bottoms of the valleys are associated with the processes of leaching and erosion as well as a significant accumulation of erosion products and mudflows. Among gravitational processes and block motions, stabilized and active displacements are the most recorded. Key words: National natural park; Ukrainian Carpathians; relief; morphostructure; morphosculpture.

RELIEF AND GEOLOGICAL STRUCTURE OF CARPATHIAN BIOSPHERE RESERVE

The relief and geological structure of Carpathian Biosphere Reserve represent the features of the geological and geomorphological structure of the four geomorphological regions of the Ukrainian Carpathians. The block mid-mountains of the Polonynsko-Chornohirsky Carpathians (Chornohora, Svydovets, and Uholsko-Shyrokoluzhansky massifs) and the folded mid-mountains of Marmarosy crystal massif (Marmarosy and Kuziy-Trybushansky massifs) are well protected within the reserve. The analysis of the morphostructure and morphosculpture of the reserve is carried out taking into account the longitudinal (NW–SE) and transverse divisions of the Ukrainian The analysis of the morphostructure and morphosculpture of the reserve is carried out taking into account the longitudinal (NW–SE) and transverse divisions of the Ukrainian Carpathians. The longitudinal division is associated with morphostructures of higher orders, such as second and third. The transverse division is associated with the fourth and fifth orders of morphostructures. In the analysis of morphosculpture of the reserve, the types characterized for all regions of Flysch and Crystal Carpathians are allocated. All mountain massifs and ridges could be characterized by an asymmetrical structure, such as steep northeastern slopes and acclivous southwestern slopes. The relic morphosculpture is represented by: 1) fragments of denudation surfaces of different ages such as Polonynska, Pidpolonynska, and riparian; 2) ancient glacial and extra glacial landforms; 3) areas of ancient longitudinal valleys. River valleys with a complex of different age terraces represent inherited morphosculpture. Modern morphodynamic processes are represented by height (tier) differentiation. The processes of sheet erosion, deflation, and rill erosion play an important role in the relief modeling for the tiers of strongly dissected mid-mountain relief. The lower tier of the terraced and non-terraced bottoms of the valleys are associated with the processes of leaching and erosion as well as a significant accumulation of erosion products and mudflows. Stabilized and active displacements are the most recorded among the gravitational processes and block motions. Key words: Carpathian Biosphere Reserve; Ukrainian Carpathians; relief; morphostructure; morphosculpture.

A Comprehensive Review of Intestinal Atresias

A Comprehensive Review of Intestinal Atresias

Formation and early development of the Monostroma nitidum Wittrock

The monostromatic green macroalga Monostroma nitidum Wittrock is attracting global attention due to its commercial importance. In this study, field Monostroma strains were collected from Dalang, Naozhou Island, on the South China Sea Coast of Zhanjiang City. They were identified as M. nitidum using morphological and developmental characteristics combined with nuclear-encoded internal transcribed spacer sequences. Moreover, the early ontogeny of M. nitidum was observed for the first time in detail under a photomicroscope. The active zoospores had a spherical shape, were 6.88 μm in diameter, and completely settled on the Petri dish 1 day after release. The first transverse division of settled zoospores occurred on the 3rd day; the length of the elongate cells was 15.94 μm. Longitudinal divisions started to occur in the middle and at the top of erect filaments (61.27 μm in length) on the 12th day, and rhizoids began to appear at the posterior end of the microscopic filamentous thallus. The sac-like microthallus (113.79 μm in length) that developed from erect filaments was observed on the 18th day and divided longitudinally towards the rhizoids to produce expanded monostromatic blades (178.96 μm in length) on the 24th day. These data increase our understanding of the ontogeny of M. nitidum.

Efficient Detection of Longitudinal Bacteria Fission Using Transfer Learning in Deep Neural Networks.

A very common way to classify bacteria is through microscopic images. Microscopic cell counting is a widely used technique to measure microbial growth. To date, fully automated methodologies are available for accurate and fast measurements; yet for bacteria dividing longitudinally, as in the case of Candidatus Thiosymbion oneisti, its cell count mainly remains manual. The identification of this type of cell division is important because it helps to detect undergoing cellular division from those which are not dividing once the sample is fixed. Our solution automates the classification of longitudinal division by using a machine learning method called residual network. Using transfer learning, we train a binary classification model in fewer epochs compared to the model trained without it. This potentially eliminates most of the manual labor of classifying the type of bacteria cell division. The approach is useful in automatically labeling a certain bacteria division after detecting and segmenting (extracting) individual bacteria images from microscopic images of colonies.

Embryo and endosperm development in Billbergia nutans H. Wendl. ex Regel (Bromelioideae - Bromeliaceae) and its implications for the embryonomy of Bromeliaceae

The proposition of patterns, types, and variations for embryogenic events is one of the objectives of embryonomy. Bromeliaceae is a diverse neotropical plant family for which this approach has been ambiguously and rarely discussed in detail. In this study, we analyzed the embryogeny and endospermogenesis of Billbergia nutans H. Wendl. ex Regel, a bromeliad worldwide known as ornamental and with no embryogenic studies recorded to date. Seeds of B. nutans were periodically collected after manual pollination and processed with standard methods for analysis under light microscopy. Among other embryogenic characteristics, we highlight the longitudinal division of ca and its major contribution to the formation of the embryo, the presence of hypophysis derived from m, and the formation of the first internal cells of the proembryo from q. Endospermogenesis is helobial, and the cellularization in each chamber occurs at specific stages of the embryogenesis. The embryonic number is 211 and the embryonomic formula ca = pco + phy + pvt + icc; cb = iec + ico + co + s, typical of the Onagrad Type. This classification is unprecedented for Bromeliaceae, although it can be contradictorily applied to other species of the family. Special embryogenic characteristics of B. nutans, as the contribution of n in the formation of the root cap and the longitudinal divisions in the suspensor cells, led to the proposal of a new variation for this type: the Billbergia Variation, which also can be applied to some other Bromeliaceae species.

GEOLOGICAL-GEOMORPHOLOGICAL ANALYSIS OF NATIONAL NATURAL PARKS OF THE NORTH-WESTERN PART OF THE UKRAINIAN CARPATHIANS

In the stydy an analysis of the geological structure and relief of Uzhansky, “Skolivsky Beskydy”, and “Boykivshchyna” national natural parks (NNP), located in the north-western part of the Ukrainian Carpathians, is presented. Uzhansky NNP is located within the Polonynsko-Chornohirska and Vododilno-Verkhovyna geomorphological regions, “Skolivski Beskydy” NNP is situated in the Skibovy Carpathians, and the newly created “Boykivshchyna” NNP is located within the Vododilno-Verkhovyna and Skybovi Carpathians. The analysis of the morphostructure and morphosculpture of national parks is carried out taking into account the longitudinal (N-W–S-E) and transverse divisions of the Ukrainian Carpathians. The longitudinal division is associated with higher morphostructures of higher orders – the second and third, with the transverse is associated with the fourth and fifth morphostructures. In the analysis of morphosculpture of national parks, the types which are characteristic of the Carpathian Flysch belt are allocated. All mountain ranges and ridges are characterized by an asymmetrical structure – steep northeastern slopes and declivous southwestern slopes. The relic morphosculpture is represented by: 1) fragments of denudation surfaces of different ages such as Beskid, Pidbeskid, and riparian; 2) extra glacial and firn glaciations; 3) areas of ancient longitudinal valleys. Inherited morphosculpture is represented by river valleys with a complex of terraces of different ages. Modern morphodynamic processes represent by height (tier) differentiation. In the tiers of strongly dissected mid-mountain and low-mountain relief, the processes of planar erosion, deflux, and linear erosion play an important role in the modeling of the relief. The lower tier of the terraced and non-terraced bottoms of the valleys are associated with the processes of leaching and erosion as well as a significant accumulation of erosion products and mudflows. Among gravitational processes and block motions, stabilized and active displacements are the most recorded. Keywords: National natural park; Ukrainian Carpathians; relief; morphostructure; morphosculpture.

SUBSTANTIATION OF CHIPPING FRACTURE MECHANICS DURING DRAWING OF CYLINDRICAL SURFACES WITH ALLOWANCE

The mechanics of chip fracture when cutting the allowance of pre-divisible technological grooves was studied for the first time, and the relationship between the profile and depth of the latter and the characteristics of the stress-strain state in the chip formation zone (relative shear, chip shrinkage, shear angle, front angle, contact processes . This article discusses a more complex problem - the longitudinal division of chips or allowance. Most researchers are inclined to believe that this problem should be solved by pre-dividing the allowance by a network of special chip-splitting ring or screw grooves. The depth of these grooves should be 0.6… 0.95 of the amount of rise on a single tooth of the broach. The results of the study of the mechanics of chip destruction are described when the tool meets the process groove in the drawing process. The connection between the structure of the pipe and the intensively deformed state in the zone of chip formation is shown. From the obtained results the following follows. Preliminary deformation hardening by means of deforming drawing allows to increase hardness of OM twice (steel 10), to 60% (steel 35), to 50% (steel 45) and to 25% (aluminum alloy AK6). This significantly reduces the shrinkage coefficient of chips (respectively 2; 1.4; 1.4 and 1.3 times) and the actual previous angle (at a sharpening angle γ = 15⁰, respectively: from 36⁰ to 18⁰; from 25⁰ to 17⁰; from 21⁰ to 16⁰ and from 22⁰ to 17⁰). All this indicates a decrease in the intensity of the cutting process with increasing intensity of the previous HPD The following minimum values of the groove profile angle for the investigated materials 2φmin were determined: 80⁰ (steel10); 60⁰ (steel 35); 50⁰ (steel 45 and alloy AK6). It is established that the minimum depth of the chip-splitting groove hC is determined from the condition of chip destruction when the tangential stresses in the shear zone are exceeded above the shear resistance of the processed material. The following values of the minimum depth of the chip-splitting groove for the studied materials were obtained: hCmin = (0.4… 0.55) Sz - steels 35 and 45; hCmin = (0.55 (0.6) Sz - AK6 alloy.

Stress-strain state of metal in deformation zone during production of steel section billets on the unit of combined continuous casting and deformation. Report 1

Volumetric problem of determining stress-strain state of metal in deformation zone during forming of three section billets from the slab by separating collars of grooved strikers on the unit of combined continuous casting and deformation was set and solved. The expediency of using such unit was justified for longitudinal division mation are given for St3sp steel. The solid-state finite elements used in calculation of stress-strain state of metal in deformation zone and dimensions of the grid are described. The results of calculation of stress-strain state of metal in deformation zone were obtained by solving the problem of elasticity by the finite element method in volumetric formulation. The results of calculation of displacements and stresses in deformation zone are given in form of graphs and tables by working surfaces in four cross sections and are presented for characteristic points. Values and regularities of distribution of axial displacements in width and length of deformation center were determined during introduction of strikers separating collars into continuously cast slab in production of three section steel billets on the unit of combined continuous casting and deformation.