scholarly journals RESEARCH OF TRANSIENT PROCESSES OF PRESSURE CHANGE WHEN OPERATING A HYDRAULIC SYSTEM WITH FOUR CONNECTED HYDRAULIC MOTORS

2021 ◽  
pp. 81-87
Author(s):  
Iryna Нunko
Keyword(s):  
Hydraulic System ◽  
Transient Processes ◽  
Theoretical Research ◽  
Working Fluid ◽  
Integration Step ◽  
Technological Parameters ◽  
Pressure Zone ◽  
Hydraulic Motors ◽  
The Moment

The publication is devoted to the study of the quality of the hydraulic system with four series-connected hydraulic motors. These hydraulic systems can be used to drive the working bodies of agricultural machines, have significant advantages in their layout, but at the same time and disadvantages, the elimination of which requires a detailed study of the processes occurring during the operation of this type of system. The analysis of the previous works of scientists in this area allows us to conclude that it is possible to conduct theoretical research in this direction. A mathematical model of the proposed hydraulic system has been developed, which takes into account the effect of external load on the shafts of hydraulic motors, the inertia of the system, the effect of leaks from the connections of the elements of the hydraulic system and possible overflows of the working fluid from the high-pressure zone to the low-pressure zone. At this stage, wave processes occurring in the cavities of the hydraulic system were not taken into account. The solution of the resulting system of differential equations was carried out using the Runge-Kutta-Feldberg method with automatic change of the integration step in the mathematical package MathCad. The resulting transient processes were analyzed for the amplitude of pressure surges and the frequency of its change. Carrying out this analysis allows you to obtain comprehensive information about the nature of transient processes in the hydraulic system in order to find such a ratio of design and technological parameters, in which the system under study met the requirements regarding the quality of work as part of a technological machine. During the research, special attention was paid to the processes occurring at the moment of starting the hydraulic system, and the moment of application of the technological load.

scholarly journals Justification of the Kinematic Diagrams for the Distribution System of a Planetary Hydraulic Motor

2018 ◽  
Vol 7 (4.3) ◽  
pp. 6 ◽  
Author(s):  
Angela Voloshina ◽  
Anatolii Panchenko ◽  
Oleg Boltynskiy ◽  
Igor Panchenko ◽  
Olena Titova
Keyword(s):  
Distribution System ◽  
Hydraulic System ◽  
Hydraulic Drive ◽  
Fluid Distribution ◽  
Working Fluid ◽  
Hydraulic Motor ◽  
Hydraulic Motors ◽  
Output Characteristics ◽  
Kinematic Diagram ◽  
The Impact

The output characteristics of a planetary (orbital) hydraulic motor could be significantly improved if the kinematic diagrams for its working fluid distribution system are chosen correctly and substantiated. Fluctuations in the flow of the power fluid cause pulsation in the cavity of the input pressure of the hydraulic motor. This results to vibration of the hydraulic system elements. Thus, the hydraulic motor can be considered as a source of pulsation which leads to functional failures of the hydraulic system. As they run at low rotational speeds with high torque, planetary hydraulic motors are commonly applied for a hydraulic drive in active working tools of self-propelled machinery. It has been established that one of the main components of a planetary hydraulic motor, which causes pressure pulsations, is its distribution system. The frequency and amplitude of these pulsations depends on the kinematic diagram for the distribution system of the power fluid. Therefore, we studied how the kinematic diagram for the distribution system effects on the output characteristics of a planetary motor. Since the change in the capacity of a distribution system with various kinematic diagrams influences on the output characteristics of a planetary motor, the impact was investigated. The kinematic diagrams, which improve the output characteristics of planetary hydraulic motors, were justified. 

scholarly journals Research of the properties of spent liquor from cooking of hardwood semi-cellulose at different ratio of green and white liquors

2020 ◽  
pp. 246-258
Author(s):  
Ю.В. Севастьянова ◽  
Е.А. Топтунов ◽  
Н.В. Щербак ◽  
П.В. Солнцев
Keyword(s):  
Wood Chips ◽  
Mechanical Processing ◽  
Annual Plants ◽  
Technological Parameters ◽  
Cellulose Production ◽  
Green Liquor ◽  
Deciduous Wood ◽  
The Moment ◽  
Spent Liquor

Основным полуфабрикатом для производства бумаги для гофрирования (флютинга), используемой в композиции тарного картона, является полуцеллюлоза из лиственных пород древесины. Производство полуцеллюлозы базируется напредварительной химической и последующей механической переработке древесной щепы или однолетних растений. Технология производства полуцеллюлозы с использованием в качестве варочного реагента - зеленого щелока позволяет упростить процесс приготовления варочного раствора и сократить схему регенерации химикатов из отработанных щелоков. Однако сведения о технологических параметрах варки, качестве полуцеллюлозы представлены недостаточно полно, отсутствуют подробные данные об избирательности процесса делигнификации лиственных пород древесины, произрастающих в СЗФО, а также недостаточно информации о составе и свойствах отработанного щелока, влиянии породного сырья на свойства щелоков. Исследование выполнено с целью изучения свойств отработанного (оранжевого) щелока, а именно его плотности, полученного при варке лиственной полуцеллюлозы с различным соотношением зеленого и белого щелоков. Основываясь на результатах исследований свойств отработанного производственного щелока от варки лиственной полуцеллюлозы на смеси белого и зеленого щелоков: 1) не выявлено значительного влияния изменения соотношения зеленого и белого щелоков при варке лиственной полуцеллюлозы на плотность отработанного щелока в диапазоне температуры от 15 до 90 °С и концентрации сухих веществ от 5 до 10%; 2) разработана математическая модель - полином 1 степени, - достоверно характеризующая зависимость плотности отработанного щелока от концентрации и температуры для производства лиственной полуцеллюлозы с различным соотношением зеленого и белого щелоков: ρ = 0,992 + 0,0083 · х - 0,0003 · t - 0,000012 · х · t - 0,00000032 · t 2 - 0,0001158 · х 2. The main semi-finished product for the production of fluting is semi-cellulose from hardwood. Semi-cellulose production is based on preliminary chemical and subsequent mechanical processing of wood chips or annual plants. The technology for the production of semi-cellulose using green liquor makes it possible to simplify the process of preparing the cooking solution and the recovery of chemicals from waste liquors. This method is used abroad, in our country the method of cooking semi-cellulose with green liquor is currently carried out at one of the enterprises in Russia. However, at the moment, information on the technological parameters of cooking and the quality of semi-cellulose is not fully presented, there are no data on the selectivityof the delignification process (removal of lignin) of deciduous wood when cooking with green liquor, as well as information on the composition and properties of the spent liquor. The study was carried out with the aim of studying the properties of waste (orange) liquor, namely its density obtained by cooking hardwood semi-cellulose with different ratios of green and white liquors. Based on the results of studies of the properties of waste industrial liquor from hardwood semi-cellulose cooking on a mixture of white and green liquors: no significant effect of the ratio of green and white liquors during hardwood semi-cellulose cooking on the density of waste liquor in the temperature range from 15 to 90 °С and the concentration of dry substances from 5 to 10%; a mathematical model has been developed - a polynomial of the 1st degree, - reliably characterizing the dependence of the density of the spent liquor on concentration and temperature for the production of hardwood semi-cellulose with different ratios of green and white liquors ρ = 0,992 + 0,0083 · х - 0,0003 · t -- 0,000012 · х · t - 0,00000032 · t 2 - 0,0001158 · х 2.

Clinical case of a comorbid patient with arterial hypertension

2020 ◽  
pp. 31-39
Author(s):  
Ella Polozova ◽  
Vsevolod Skvortsov ◽  
Olga Radaykina ◽  
Mariya Narvatkina ◽  
Anastasiya Seskina ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Risk Factors ◽  
Arterial Hypertension ◽  
Clinical Picture ◽  
Clinical Case ◽  
Diagnosis And Treatment ◽  
The Moment

The widespread prevalence of comorbid pathology determines the relevance of this problem. Comorbid pathology due to the interaction of diseases, drug pathomorphism, age characteristics of the patient, significantly changes clinical picture and course of the main nosology, affects severity of complications and their nature, significantly affects quality of life and prognosis of patients. Diagnosis and treatment of many diseases is complicated in the conditions of comorbidity. The article presents a clinical case of a comorbid patient with arterial hypertension from the moment of exposure to risk factors and ending with the formation of many concomitant diseases, as an example of trans-nosological comorbidity.

scholarly journals Results of Laboratory Studies of the Automated Sorting System for Root and Onion Crops

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1257
Author(s):  
Alexey Dorokhov ◽  
Alexander Aksenov ◽  
Alexey Sibirev ◽  
Nikolay Sazonov ◽  
Maxim Mosyakov ◽  
...  
Keyword(s):  
Control System ◽  
Automatic Control ◽  
Automatic Control System ◽  
Technological Parameters ◽  
Post Harvest ◽  
Manual Sorting ◽  
Sorting System ◽  
Working Bodies ◽  
Automatic Removal

The roller and sieve machines most commonly used in Russia for the post-harvest processing of root and tuber crops and onions have a number of disadvantages, the main one being a decrease in the quality of sorting due to the contamination of working bodies, which increases the quantity of losses during sorting and storage. To obtain high-quality competitive production, it is necessary to combine a number of technological operations during the sorting process, such as dividing the material into classes and fractions by quality and size, as well as identifying and removing damaged products. In order to improve the quality of sorting of root tubers and onions by size, it is necessary to ensure the development of an automatic control system for operating and technological parameters, the use of which will eliminate manual sorting on bulkhead tables in post-harvest processing. To fulfill these conditions, the developed automatic control system must have the ability to identify the material on the sorting surface, taking into account external damage and ensuring the automatic removal of impurities. In this study, the highest sorting accuracy of tubers (of more than 91%) was achieved with a forward speed of 1.2 m/s for the conveyor of the sorting table, with damage to 2.2% of the tubers, which meets the agrotechnical requirements for post-harvest processing. This feature distinguishes the developed device from similar ones.

scholarly journals 104 - Awareness of Dementia and Coping to Preserve Quality of Life: A Five-Year Longitudinal Narrative Study

2020 ◽  
Vol 32 (S1) ◽  
pp. 8-8
Author(s):  
K. Thorsen ◽  
M. C. N. Dourado ◽  
A. Johannessen
Keyword(s):  
Quality Of Life ◽  
Coping Styles ◽  
Adaptive Function ◽  
Narrative Study ◽  
People With Dementia ◽  
The Moment ◽  
And Coping ◽  
Scientific Fields ◽  
Multidimensional Concept

AbstractBackground:Awareness of dementia is examined in different scientific fields as significant for assessment of diagnosis, and for treatment and adaptation to the disease. There are very few longitudinal studies of individual experiences of awareness among people with dementia, related to quality of life.Aim:To examine how younger people (< 65 years) with dementia (YOD) express awareness of the dementia and how, over time, they seem to handle awareness as a strategy to preserve quality of life.Method:A longitudinal qualitative study with individuals with YOD was performed with interviews every six months over five years for a maximum of ten interviews. The interviews were analysed by modified grounded theory.Findings:Awareness is a complex, multidimensional concept. Awareness of dementia is predisposed by personality, life history and established coping styles. The main coping styles – live in the moment, ignore the dementia, and make the best of it – seem to be rather consistent throughout the progression of the disease. Transitions in life situation, such as moving to a nursing home, may change the individual’s awareness of dementia.Conclusion:Unawareness of dementia may have an important adaptive function to preserve quality of life. To increase awareness must be approached with reflexivity and the utmost sensitivity.

Death or Declaw: Dealing with Moral Ambiguity in a Veterinary Hospital

2005 ◽  
Vol 13 (4) ◽  
pp. 315-342 ◽  
Author(s):  
Dana Atwood-Harvey
Keyword(s):  
Medical Practice ◽  
Organizational Support ◽  
Theoretical Research ◽  
Best Interest ◽  
Political Debate ◽  
Self Identity ◽  
Staff Members ◽  
Moral Ambiguity ◽  
Veterinary Hospital

AbstractThe medical practice of declawing has received much political debate over the past few years. Yet, empirical and theoretical research on how this practice is maintained and the ethical positions of those who actually participate in this work is lacking. Drawing from 9 months of ethnographic fieldwork in a feline-specific veterinary hospital and open-ended interviews with veterinarians and staff, this study examines veterinary staff members' attitudes toward, and strategies for, dealing with the medical practice of declawing. Specifically, findings show that a number of staff felt uncomfortable with their participation in onychectomy (declawing) and relied heavily on organizational support structures to cope both with these feelings and the moral ambiguity about the practice. Relying on these structures, the veterinarians and their staff are able simultaneously to define felines as subjects worthy of respect for their quality of life, protect their own self-identity as people who work toward the best interest of animals, and paradoxically support action toward felines that they find morally objectionable.

scholarly journals Meaningful Engagement Among Assisted Living Residents With Dementia: Successful Approaches

2021 ◽  
pp. 073346482199686
Author(s):  
Candace L. Kemp ◽  
Alexis A. Bender ◽  
Joy Ciofi ◽  
Jennifer Craft Morgan ◽  
Elisabeth O. Burgess ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Qualitative Study ◽  
Assisted Living ◽  
Care Partners ◽  
Meaningful Engagement ◽  
Care Practices ◽  
The Moment ◽  
Record Review

Meaningful engagement is an important dimension of quality of life and care for persons living with dementia, including the growing number who reside in assisted living communities. This report presents preliminary findings from an ongoing qualitative study aimed at identifying best care practices to create and maintain meaningful engagement among persons with dementia. Over a 1-year period, we conducted interviews, residents’ record review, and participant observations in four diverse care communities. Our analysis identified four approaches that successfully promote meaningful engagement: (a) knowing the person, (b) connecting with and meeting people where they are, (c) being in the moment, and (d) viewing all encounters as opportunity. Incorporation of these approaches in care routines and adoption by all care partners can promote meaningful engagement, including during crises such as COVID-19.

Study on the effective discharge energy mechanism of vertical ultrasonic vibration assisted EDM processing

2021 ◽  
pp. 095440542110285
Author(s):  
Yinghuai Dong ◽  
Guangyan Li ◽  
Yan Wang ◽  
Jianbao Song ◽  
Shuo Yang ◽  
...  
Keyword(s):  
Ultrasonic Vibration ◽  
Theoretical Research ◽  
Discharge Energy ◽  
Movement Path ◽  
Energy Mechanism ◽  
Effective Discharge ◽  
Parameter Matching ◽  
Discharge Gap ◽  
Conventional Machining

Compared to traditional EDM processing, UEDM (Ultrasonic Vibration Assisted EDM) have a great improvement in optimizing discharge environment. In this study, ultrasonic vibration is attached to the electrode. According to the relative positional relationship between the movement path of the electrode tip and the discharge gap, four working states of UEDM are defined. The four working states are the path within the discharge gap, the path in contact with the edge of the discharge gap, part of the electrode end path outside the discharge gap, and the path in contact with the workpiece, respectively. States are analyzed from the effective discharge energy and discharge frequency. A mathematical model for effective discharge energy and surface roughness is established for two conventional working states. The correctness of the theoretical research is verified by experiments. As the experiment results shown, the influence of ultrasonic amplitude on the energy of UEDM is primary, while frequency is secondary. A working state with better discharge stability and higher discharge energy when the electrode end path is in contact with the edge of the discharge gap. In the first three conventional machining states, the surface quality of the workpiece increases with the increase of ultrasonic amplitude and frequency. The study can provide scientific guidance for parameter matching of UEDM.

Surgical methods of treatment of chronic heart failure and their place in modern clinical recommendations

2020 ◽  
Vol 22 (4) ◽  
pp. 183-191
Author(s):  
O. T. Kotsoeva ◽  
A. V. Koltsov ◽  
V. V. Tyrenko ◽  
A. A. Ialovets
Keyword(s):  
Quality Of Life ◽  
Heart Failure ◽  
Chronic Heart Failure ◽  
Left Ventricle ◽  
Heart Transplantation ◽  
Mechanical Circulatory Support ◽  
Circulatory Support ◽  
Surgical Methods ◽  
The Moment

This review discusses a number of aspects of surgical methods for treating severe chronic heart failure: resynchronizing therapy, mechanical circulatory support systems, and heart transplantation. Surgical methods for the treatment of heart failure are a rapidly developing field of modern cardiology and cardiac surgery. The main surgical method of treatment was and remains orthotopic transplantation of a donor heart. The advent of implantable systems has affected the problem of heart transplantation. Over the past decade, the use of mechanical circulatory support systems has grown significantly. At the moment, there are 3 main directions: creating devices for auxiliary blood circulation, various modes and methods of electrical stimulation of the myocardium, creating devices that mechanically remodel the heart chambers (left ventricle). All of these directions to some extent (depending on the evidence base) have found their place in modern recommendations for the treatment of chronic heart failure. The use of mechanical left ventricular remodeling shows good results in patients suffering from symptomatic heart failure, which leads to a significant and persistent decrease in the volume of the left ventricle and improvement of its function, symptoms and quality of life. Despite the fact that at the moment the geography and prevalence of their use is small, the number of implanted devices will only grow. Thus, given the need for frequent hospitalizations and high treatment costs, it is necessary to improve modern methods of surgical treatment of severe and terminal heart failure, make them more accessible, which will affect the duration and quality of life of these patients.

Criteria for assessing the performance of the rehabilitation process

2021 ◽  
pp. 66-69
Author(s):  
R.O. Ogureshnov ◽  
Keyword(s):  
Rehabilitation Process ◽  
Theoretical Substantiation ◽  
The Moment

This article discusses the problem of assessing the effectiveness of the rehabilitation process. The assessment of the effectiveness of the rehabilitation process is recognized by many researchers as one of the most difficult in the theoretical substantiation of the process of rehabilitation and habilitation, in this regard, there are no uniform approaches to assessing the effectiveness of rehabilitation today. The article presents studies by several authors on this issue. Rehabilitation of patients after a stroke most often occurs with the use of rehabilitation complexes. The possibility of applying the assessment of the effectiveness of rehabilitation to such complexes is very relevant, since at the moment there is no unified system for determining the quality of rehabilitation complexes.

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