bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental study of hydraulic equipment operation process
Authors: Rustamov Kamoliddin , Komilov Samandar , Kudaybergenov Mavlon , Shermatov Shamshir , Xudoyqulov Shahzod 
Published: June 2021

Relevance. When the hydraulic fluid is operated for several cycles, the impact on hydraulic performance and longevity is greatly increased. So, there are several ways to fix this problem. To increase the efficiency of the hydraulic system, it is necessary to study the working processes, the hydraulic systems of the quick-change equipment of the machine with a lawn of the kshpare made as a whole, and the equipment of the machine is attached to the suspension device. The complexity of these processes lies in the fact that they allow experimental research and verification of results using mathematical models.Aim. The purpose of the experimental study in this dissertation is to study the effect of forces acting on the hydraulic system when excavating the hydraulic system of a multipurpose machine and substantiate the parameters by assessing power use efficiency.Methods. Checking the suitability of the working fluid during earthworks, as well as the mathematical model. In this case, we studied the hydraulic system of a single-bucket excavator, the device of quick-change equipment for a universal machine.Results. The theoretical work performed has been verified and the confirmation of the operation of a multipurpose machine designed with earth and dozer equipment. The installation of equipment based on TTZ-80 made it possible to carry out experimental research with the most energy-intensive workflow, determining energy efficiency indicators for excavation and leveling.Conclusion. Comprehensive tests made it possible to conclude that the characteristics of the developed design and the characteristics of the engine of the base machine - the TTZ-80.10 - KM-1 tractor, overcome the resistance encountered during technological operations of a multipurpose machine.
Tracking the local seismicity level in the active influence zone of the southern Uzbekistan reservoirs
Authors: Khamidov Lutfulla , Turapov Mahmud , Mahkamov Soqijon , Artikov Farkhod , Suyunov Shavkat 
Published: June 2021

Assessment of local seismicity caused by human engineering activity is a necessity after several earthquakes have been recorded in world practice, which destroyed a hydraulic structure, a dam and accompanied by human casualties.The Tupalang, Gissarak and Pachkamar reservoirs, operated in southern Uzbekistan, are located in the mountain system of the southern part of the Tien Shan seismogenic fault.According to the general seismic zoning, the zones where these reservoirs are located are classified as 8-9 magnitude shakes during strong earthquakes. Localisation of local earthquakes associated with the operation of these reservoirs is necessary for taking operational measures to prevent possible emergencies associated with an increase in the level of technogenic seismicity.Methods for assessing the local seismic regime were used to track the level of local seismicity. The catalogs of local earthquakes occurring in the zone of active influence of reservoirs have been compiled.The seismic activity levels and changes in the angle of inclination of the recurrence of earthquakes were determined for each object separately. The dependence of the variation in the level of local seismicity on the mode of operation of reservoirs has been revealed.Several evidence of the negative impact of large hydraulic reservoirs on the deformation and seismic state of the zones of influence of reservoirs in southern Uzbekistan have been identified.
Exact method to solve of linear heat transfer problems
Authors: Abdullayev Akmaljon , Kholturayev Kholsaid , Safarbayeva Nigora 
Published: June 2021

When approximating multidimensional partial differential equations, the values of the grid functions from neighboring layers are taken from the previous time layer or approximation. As a result, along with the approximation discrepancy, an additional discrepancy of the numerical solution is formed. To reduce this discrepancy when solving a stationary elliptic equation, parabolization is carried out, and the resulting equation is solved by the method of successive approximations.
This discrepancy is eliminated in the approximate analytical method proposed below for solving two-dimensional equations of parabolic and elliptic types, and an exact solution of the system of finite difference equations for a fixed time is obtained.
To solve problems with a boundary condition of the first kind on the first coordinate and arbitrary combinations of the first, second and third kinds of boundary conditions on the second coordinate, it is proposed to use the method of straight lines on the first coordinate and ordinary sweep method on the second coordinate. Approximating the equations on the first coordinate, a matrix equation is built relative to the grid functions. Using eigenvalues and vectors of the three-diagonal transition matrix, linear combinations of grid functions are compiled, where the coefficients are the elements of the eigenvectors of the three-diagonal transition matrix.
Boundary conditions, and for a parabolic equation, initial conditions are formed for a given combination of grid functions. The resulting one-dimensional differential-difference equations are solved by the ordinary sweep method. From the resulting solution, proceed to the initial grid functions.
The method provides a second order of approximation accuracy on coordinates. And the approximation accuracy in time when solving the parabolic equation can be increased to the second order using the central difference in time.
The method is used to solve heat transfer problems when the boundary conditions are expressed by smooth and discontinuous functions of a stationary and non-stationary nature, and the right-hand side of the equation represents a moving source or outflow of heat.
Experimental study of horizontal effects of flow on non-erosion absorbers in the presence of cavitation
Authors: Obidov Bakhtiyor , Vokhidov Oybek , Suyunov Javlon , Nishanbaev Khayrulla , Rayimova Iroda , Abdukhalilov Abomuslim 
Published: June 2021

This article is devoted to one relatively small issue of the dynamics of hydraulic structures, the determination of horizontal hydrodynamic loads on energy absorbers of a high-pressure catchment area in a cavitating flow in the presence of erosion-free absorbers. In connection with the intensive construction of high and medium-pressure hydroelectric systems, spillways that operate at high flow rates, a very urgent task is to develop reliable and economical downstream devices that provide intensive damping of flow energy in a stilling well with favorable uninterrupted flow regimes and the absence of cavitation erosion of streamlined elements.
Traditional methods of extinguishing energy using stilling wells and walls do not always solve the problem. In several cases, additional elements such as energy absorbers are installed, which effectively deal with malfunctioning currents. However, most of the used types of absorbers have a serious drawback - they are destroyed during cavitation studies by prof. N.P. Rozanov and his students made it possible, based on experiments, to develop several types of erosion-free or close to erosion-free dampers and obtain a dependence to determine the hydrodynamic loads acting on them at various stages of cavitation. This made it possible to use energy absorbers at high flow rates, which was done at the spillways of the Shamkhor and Artyomovsk hydroelectric power plants.
Force effects of the flow on energy absorbers in the presence of cavitation
Authors: Umurzakov Uktam , Obidov Bakhtiyor , Vokhidov Oybek , Musulmanov Furqat , Ashirov Boyburi , Suyunov Javlon 
Published: June 2021

As the experience of operating high-pressure spillway structures shows, the operating conditions of the downstream extinguishing devices are very difficult.
At flow rates, more than 12–15 m/s, downstream damping devices, as a rule, operate in a cavitation mode. First of all, this mode of operation gives rise to erosional destruction of the damper itself and the waters near it. This occurs where the cavitation torch closes on the structure.
Attempts to avoid these desirable phenomena by lining erosion sites with steel sheets do not always lead to the desired result since it is not uncommon for the steel lining to be torn off by hydrodynamic forces.
The separation of the cladding occurs in two cases: firstly, when the cladding is not in close contact with the concrete to be protected, and secondly, its anchoring is not enough. In both cases, fracture occurs from fatigue phenomena in the metal due to multiple oscillatory cycles from hydrodynamic loads.
It is difficult to avoid this in cavitation modes since the spectrum of pressure pulsations, in this case, is very wide, which leads to oscillations of linings at resonant frequencies. Apparently, the strength of the linings is an object of special research, and in the future, it should be dealt with theoretically and experimentally.
Hydrodynamic forces at high flow rates in the zone of intense energy extinguishing can reach such values that they can lift and overturn concrete slabs of water walls and water walls.
Currently, there are practically no specific and accounting for vertical hydrodynamic loads on slabs of water walls in the presence of cavitation on erosion-free absorbers in the technical literature.
To a certain degree of approximation, it is possible to use experimental data obtained on a model of the same structure but operating without cavitation, as data on hydrodynamic loads in the downstream of structures operating in a cavitation mode. The main disadvantage of such comparisons is that there is no guarantee that the amplitude and frequency characteristics of the flow during cavitation do not change (in particular, the amplitudes do not increase) as the cavitation limit is approached.
Structure and properties of the modified diffusion nitride-oxide surface layer
Authors: Eshkabilov Kholikul , Berdiyev Sherzod 
Published: June 2021

To combine the processes of gas nitriding and oxidation in water vapor, the effects of the atmospheric nitrogen potential in dissociated ammonia on the formation of surface diffusion nitride phases are studied.Modification of the surface nitride layer with oxygen was carried out by oxidation of the nitride zone at the second stage of obtaining an oxycarbonitride layer.The corrosion and wear-resistant properties of the nitride-oxide layer t of the lowest nitride layer are investigated, depending on the phase changes in the nitride layer after oxidation. The distributions of the elements in the nitride-oxide layer are determined, and the nature of the formation of the modified surface layer under the combination of gas nitriding with subsequent oxidation in water vapor is established.
Vitamin C: Ein Hoffnungsträger in Prävention wie Therapie der COVID-19-Infektion?
Authors: Stange Rainer 
Published: June 2021

SummaryLaut Nationaler Verzehrsstudie II aus dem Jahr 2008 übertrifft die Vitamin-C-Aufnahme im Median in Deutschland die DGE-Empfehlungen deutlich. Vitamin C ist das beliebteste Vitaminsupplement, auch bei ausreichender Aufnahme mit der Nahrung. Eine mangelnde Aufnahme wird jedoch meist weniger wahrgenommen.Bislang existieren wenige Studien mit kleinen Studienkollektiven zur Vitamin-C-Gabe bei COVID-19. Die Ergebnisse verweisen auf einen möglichen Nutzen einer hochdosierten Vitamin-C-Gabe hinsichtlich der Mortalität, der akuten Imflammation sowie der Krankenhausaufenthaltsdauer. Im Clinical-Trials-Register finden sich 45 registrierte Studien, sodass mit weiteren Veröffentlichungen gerechnet werden kann.Patienten, bei denen die Wahrscheinlichkeit für eine ungenügende Vitamin-C-Versorgung groß erscheint, sollte in der Prophylaxe besondere Aufmerksamkeit gelten. Auf Dauer sollten praktisch leicht nutzbare Elemente aus der Ernährungstherapie aufgezeigt werden.
Presión en la reparación de manguito rotador con suturas transóseas y Mason-Allen modificado
Authors: Fernández Julio José Contreras , Osses Oscar Sepúlveda , Esper Nicolás Prado , Silva Ricardo Guzmán , Verdugo Rodrigo Liendo , Rex Francisco Soza 
Published: June 2021

Resumen
Objetivo Comparar el promedio de curva de presión de contacto y el porcentaje de presión de contacto residual final en la interfase tendón-huella de una reparación transósea (TO) realizada con nudos cruzados y una configuración Mason-Allen modificada (MAM).
Métodos Se utilizaron ocho hombros de cordero para simular una rotura de manguito rotador. Se midió la presión con un sensor digital. Se registró la presión basal durante la aplicación de carga cíclica y al final de la intervención. Se compararon dos reparaciones: dos túneles TOs con nudos cruzados (TOCs) (n = 4) y dos puntos MAMs (n = 4) utilizando suturas MaxBraid #2 (Zimmer Biomet, Warsaw, IN, EEUU). Se realizaron 1.000 ciclos, con una frecuencia de 2 Hz y una carga de 30 N. Se utilizó el test de t de Student, y se consideraron significativos valores de p < 0,05.
Resultados El promedio de curva de presión de contacto en las piezas que fueron reparadas con suturas TOCs fue de 86,01 ±  8,43%, mientras que con MAM fue de 73,28 ±  12,01% (p < 0,0004). El promedio del porcentaje residual al final del ciclado fue de 71,57% para suturas TOCs y de 51,19% para MAM (p < 0,05).
Conclusión La reparación TOC presenta mayor promedio de curva de presión de contacto y mayor porcentaje de presión de contacto residual final en la interfase tendón-huella que la reparación con sutura MAM luego de carga cíclica estandarizada, lo que podría traducirse en una mejor cicatrización del tendón.
Nivel de Evidencia Estudio de ciencia básica.
BCL11A Polymorphism in Egyptian Children with β-Thalassemia: Relation to Phenotypic Heterogeneity
Authors: Salah Nouran Y. , Ali Heba G. A. , Bassiouny Noha , Salem Lamya , Taha Sara I. , Youssef Mariam K. , Annaka Layla , Barakat Noha M. 
Published: June 2021

AbstractFetal hemoglobin (HbF) is a potent genetic modifier of β-thalassemia phenotype. B-cell lymphoma 11A (BCL11A) gene results in significant silencing of HbF. The aim of this study was to assess the prevalence of different BCL11A genotypes among a cohort of Egyptian children with β-thalassemia and to correlate them to HbF and clinical severity score. Eighty-two children with β-thalassemia (aged 12.95 ± 3.63 years) were recruited from the Pediatric Hematology Clinic, Ain Shams University. They were divided based on the clinical severity of β-thalassemia into three subgroups: 20 mild (24.4%), 24 moderate (29.3%), and 38 severe (46.3%). Age, gender, age of diagnosis, initial HbF level, transfusion history, and history of splenectomy were assessed. Anthropometric measures, signs of anemia and hemosiderosis, and the severity score were determined. Laboratory investigations such as complete blood picture, ferritin, and single gene polymorphism genotyping of the rs11886868 were also performed. Our findings showed that 16 children had CC genotype (19.5%), 38 had TC genotype (46.3%), and 28 had TT genotype (34.1%) of the rs#. β-thalassemia children with TT genotype had significantly higher severity scoring than the other two groups (p < 0.001). Moreover, mean initial HbF was found to be lower in children with TT genotype followed by TC and CC genotypes (p < 0.001). Increased γ-globin expression associated with BCL11A gene polymorphism is associated with better clinical severity of β-thalassemia.
X-Linked Myotubular Myopathy: A Novel Mutation Expanding the Genotypic Spectrum of a Phenotypically Heterogeneous Myopathy
Authors: Carvalho Andreia , Costa Carmen , Pinto Miguel , Taipa Ricardo , Gonçalves Ana , Oliveira Márcia E. , Ferreira Sofia , Ribeiro Joana Afonso 
Published: June 2021

AbstractX-linked myotubular myopathy (XLMTM), a centronuclear congenital myopathy secondary to pathogenic variants in the MTM1 gene encoding myotubularin, is typically recognized for its classic and severe phenotype which includes neonatal hypotonia, severe muscle weakness, long-term ventilator dependence, markedly delayed gross motor milestones with inability to independently ambulate, and a high neonatal and childhood mortality. However, milder congenital forms of the condition and other phenotypes are recognized. We describe a 6-year-old boy with a mild XLMTM phenotype with independent gait and no respiratory insufficiency even in the neonatal period. The child has a hemizygous novel splice site variant in the MTM1 gene (c.232–25A > T) whose pathogenicity was confirmed by cDNA studies (exon 5 skipping) and muscle biopsy findings. We also compared the phenotype of our patient with the few reported cases that presented a mild XLMTM phenotype and no respiratory distress at birth, and discussed the potential mechanisms underlying this phenotype such as the presence of residual expression of the normal myotubularin transcript.
Single-molecule calorimeter and free energy landscape
Authors: Wang Yi , Tang Zhuodong , Chen Hong-Yuan , Wang Wei , Tao Nongjian , Wang Hui 
Published: June 2021

Significance
Measuring the complete thermodynamic profile of a single molecule reveals unparalleled advantages in the biological realm. We develop a single-molecule calorimeter with plasmonic imaging and optical tweezer by probing the thermal fluctuations of single nanoparticles linked to the substrate via the single-molecule binding pair. This uncovers the complete thermodynamic information for single binding events and identifies the equilibrium state and energetic components of the free energy landscape, suggesting possibilities for offering high-throughout analysis of single-molecule interactions.
Cucurbit aphid-borne yellows virus (Cucurbit aphid-borne yellows).
Authors: Lecoq Hervé , Desbiez Cécile , Schoeny Alexandra 
Published: June 2021

Abstract

Cucurbit aphid-borne yellows virus (CABYV) was first isolated in southern France in 1988. It causes, mostly in cucurbits, more or less severe yellowing diseases according to the season and cultivar. CABYV infects several weed species and is readily transmitted in a persistent manner by ubiquitous aphids that provide an efficient means of invasiveness worldwide. Symptoms of CABYV are similar to other biotic or abiotic disorders and dating first occurrences of the virus was difficult until appropriate diagnostic methods were developed. There is evidence that CABYV is becoming more frequent in areas where it was reported earlier (France, Spain and parts of Asia) and that it might have been recently introduced into new areas (Northern Europe, South America). Therefore, CABYV may be considered as potentially invasive both in places where it has not yet been reported and where it is already present. CABYV is not regulated or on an alert list.
East Asian Passiflora virus.
Authors: Iwai Hisashi 
Published: June 2021

Abstract

East Asian Passiflora virus (EAPV) is a potyvirus that infects passion fruit Passiflora edulis. It can produce mosaic symptoms on leaves and severely malformed and woody fruits (Iwai et al., 1996). It is currently found in Japan, Taiwan and Peninsular Malaysia, although its global distribution is not yet clear.
Echinochloa crus-pavonis (gulf cockspur grass).
Authors: Kaufman Sylvan 
Published: June 2021

Abstract

Echinochloa crus-pavonis is a clump forming grass native to the Americas that is now found in Africa, Asia, Oceania and Europe. It is likely its spread was facilitated by rice cultivation around the world, as it is a frequent contaminant of rice grains. It listed as invasive and a weed of agriculture. E. crus-pavonis is widely documented as a significant weed of rice fields. It is an 'occasional weed of cultivation' in Australia. It is considered invasive in Cuba, Paraguay, Cameroon, the Ivory Coast, Nigeria, Italy and California, USA.
Cowpea mild mottle virus (angular mosaic of beans).
Authors: Brown Judith K. 
Published: June 2021

Abstract

Cowpea mild mottle virus (CPMMV) infects a wide range of cultivated legumes. It causes severe mosaic and/or necrosis on the leaves, stems and pods of beans (Phaselous), cowpea (Vigna) and soyabean (Glycine max). Yield losses of 64-80% have been recorded in groundnuts in Kenya (Bock et al., 1976, 1977) and 10-100% in soyabean in Brazil and Argentina (Brown and Rodrigues, 2017). The virus is transmitted in a non-persistent manner by the whitefly, Bemisia tabaci. CPMMV is considered endemic to Africa, but has spread to India, South-East Asia, South America, the Caribbean, Puerto Rico and Mexico. Introduction of the virus to Puerto Rico, and possibly also Mexico, is thought to have been through infected seed from South America and perhaps Africa. The virus poses a threat to soyabean production in the USA and, if introduced into mainland USA, CPMMV has potential to spread through seed, on infected ornamental or vegetable transplants, and by the viruliferous whitefly, itself if previously associated with a virus-infected host.
Armillaria novae-zelandiae.
Authors: Hood Ian 
Published: June 2021

Abstract

Armillaria novae-zelandiae is a white rot wood decay fungus and root disease pathogen that occurs in a number of countries in the Southern Hemisphere and in parts of tropical and subtropical Asia. It is not known to have been introduced to these regions, where it is presumed to be indigenous. Its designation as "invasive" is based on its propensity to establish colonies and disease centres in disease-free areas by dispersal of basidiospores from "toadstool" fruit bodies that appear on wood during the winter months. As a wood decomposer fungus A. novae-zelandiae contributes beneficially to carbon and nutrient recycling. Like many other Armillaria species it is recognized by characteristic white mycelial fans or ribbons produced beneath host bark and by its bootlace-like rhizomorphs by which it spreads vegetatively from colonized buried woody material or stump root systems to infect living host plants.Armillaria novae-zelandiae was the cause of substantial disease losses in plantations of Pinus radiata and orchards of kiwifruit vines (Actinidia deliciosa) in New Zealand from the 1970s to the 1990s. Its importance has since declined with changes in patterns of crop management, although it remains widely distributed. Much research into its control was undertaken during this period. In eastern states in Australia, A. novae-zelandiae is a minor cause of root disease in natural and planted forests, where it is of lesser importance than Armillaria luteobubalina. Its impact in other regions is unknown, but it has not been associated with reports of significant disease. Risk of unintended international spread appears to be low to negligible but should not be discounted. If intercepted, isolates of A. novae-zelandiae may be identified by laboratory culture testing or more rapidly and precisely by molecular sequencing procedures. A. novae-zelandiae is listed in the EPPO Global Database and features in the United States Department of Agriculture Agricultural Research Service fungal databases. It is considered a risk organism in Hawai'i.