scholarly journals Effect of the Frictional Properties of Sunflower Seeds on the Efficiency of Pressing Equipment

2019 ◽  
pp. 571-578
Author(s):  
Mihail Berezin ◽  
Vitaly Borisov
Keyword(s):  
Practical Importance ◽  
Oil Yield ◽  
Hydrodynamic Resistance ◽  
Experimental Unit ◽  
Special Method ◽  
Related Factors ◽  
Friction Characteristics ◽  
Pressure Time ◽  
Asymptotic Function ◽  
Volume Characteristics

Introduction. The process of oil extraction from oilseeds is very complicated as it depends on a large number of related factors. The complex porous structure of pulp is a combination of three phases: dry solids, liquid (oil), and air. Therefore, the study of the process of pulp pressing requires a special method for determining the friction characteristics of the material. Study objects and methods. To determine the friction and volume characteristics of oilseeds, an original experimental unit was developed and manufactured. The study involved samples of the same mass weighted using a high-accuracy analytic balance (permissible error = ± 5%). The first stage of the experiment featured volume characteristics of ten samples. The second stage featured friction characteristics of the five first samples obtained during the first stage at different pressures. Results and discussion. The pressure time proved to have a more significant effect on the oil yield than the pressure volume, since the complex capillary structure of the pulp demonstrated a significant hydrodynamic resistance to oil outflow. The dependence of the oil yield on the pressure was described by an asymptotic function; the limit (asymptotic) value of the pressure was 48 MPa. At this pressure, the oil yield reached φ = 54 %. The dependence of the friction coefficient on the values of temperature, pressure, and sliding velocity was described by a power-law regression equation with the coefficient of accuracy of approximation R2 = 0.96. Conclusion. The obtained data are of practical importance and can be used to improve the efficiency of pressing equipment.

Practical Importance of Spatial Resolution and Analytical Sensitivity in AEM X-ray Microanalysis

1990 ◽  
Vol 48 (2) ◽  
pp. 432-433
Author(s):  
J. Zhang ◽  
D.B. Williams ◽  
J.I. Goldstein
Keyword(s):  
Spatial Resolution ◽  
Practical Importance ◽  
Beam Current ◽  
Specimen Thickness ◽  
Analytical Sensitivity ◽  
Related Factors ◽  
X Ray ◽  
Probe Size ◽  
Excitation Volume ◽  
Two Parameters

Analytical sensitivity and spatial resolution are important and closely related factors in x-ray microanalysis using the AEM. Analytical sensitivity is the ability to distinguish, for a given element under given conditions, between two concentrations that are nearly equal. The analytical sensitivity is directly related to the number of x-ray counts collected and, therefore, to the probe current, specimen thickness and counting time. The spatial resolution in AEM analysis is determined by the probe size and beam broadening in the specimen. A finer probe and a thinner specimen give a higher spatial resolution. However, the resulting lower beam current and smaller X-ray excitation volume degrade analytical sensitivity. A compromise must be made between high spatial resolution and an acceptable analytical sensitivity. In this paper, we show the necessity of evaluating these two parameters in order to determine the low temperature Fe-Ni phase diagram.A Phillips EM400T AEM with an EDAX/TN2000 EDS/MCA system and a VG HB501 FEG STEM with a LINK AN10 EDS/MCA system were used.

Perfusion of the cerebral ventricular system in unanesthetized goats

1962 ◽  
Vol 203 (5) ◽  
pp. 763-774 ◽  
Author(s):  
J. R. Pappenheimer ◽  
S. R. Heisey ◽  
E. F. Jordan ◽  
J. deC. Downer
Keyword(s):  
Cerebrospinal Fluid ◽  
Steady State ◽  
Hydrostatic Pressure ◽  
Hydrodynamic Resistance ◽  
Nervous Control ◽  
System Composition ◽  
Bulk Absorption ◽  
Choroid Plexuses ◽  
Volume Characteristics ◽  
State Difference

Techniques have been devised for repeated perfusion of the ventriculocisternal system in chronically prepared, unanesthetized goats. The methods are designed for investigations of a) functional effects of prolonged changes of cerebrospinal fluid (CSF) composition and b) quantitative aspects of CSF formation and exchange of materials between CSF and blood. The present paper provides a technical background for subsequent papers dealing with specific problems. Goats tolerate perfusion rates of 1–3 ml/min at pressures adjustable between –10 and +30 cm H2O. Measurements are made of inflow rates, outflow rates, and concentrations of test materials entering and leaving the system. Composition of normal CSF has been determined and directions are given for preparation of sterile synthetic CSF. Brain weight is about 100 g and choroid plexuses 500 mg. CSF volume is 20–25 ml of which 8–12 ml is in the ventricles. Pressure-volume characteristics are described. Steady-state difference between inflow and outflow rates is a linear function of hydrostatic pressure; the slope is related to hydrodynamic resistance to bulk absorption. Preliminary observations are given to show effects of reduced Ca++ on nervous control of the cardiovascular system.

scholarly journals On the equilibrium and stability of a fluidized bed as a thermodynamic system

2021 ◽  
Vol 83 (2) ◽  
pp. 56-60
Author(s):  
Y. I. Shishatskii ◽  
S. A. Tolstov ◽  
A. A. Derkanosova ◽  
A. A. Ryndin
Keyword(s):  
Fluidized Bed ◽  
Practical Importance ◽  
Thermodynamic System ◽  
Hydrodynamic Resistance ◽  
Drying Process ◽  
Distribution Grid ◽  
Working Chamber ◽  
Flow Velocity Profile ◽  
Spontaneous Fluctuations ◽  
Drying Chamber

The transfer of the dispersed layer into a fluidized state makes it possible to intensify the drying process. The small size of the particles leads to an increase in the surface of their contact with the coolant at a relatively low hydrodynamic resistance. Other positive qualities of fluidization are listed, which is very important when carrying out exothermic processes. We studied the behavior of the fluidized bed during the drying process. The curve of fluidization of beet chips is shown. The suspended state of the material began when the forces of the hydrodynamic layer were equal to the weight of all its particles per unit area of the cross-section of the working chamber. The region of existence of the fluidized bed is marked. In this area, the flow was relatively equilibrium (fluidized). On the surface of the layer, small waves were observed with different frequencies and amplitudes of oscillations, as well as with spontaneous fluctuations. This mode of operation was achieved as a result of the study of the structures of the support - gas distribution grid and the drying chamber. The flow velocity profile in the working chamber is investigated. An efficient equalization of velocities with the help of flat stamped grids has been established. The results were confirmed by the spectra of the flow in the drying chamber. Oscillations on the free surface of a fluidized bed are considered. The Euler equation was written, which made it possible, as a result of various transformations, to obtain a formula for calculating the oscillation frequency of the fluidized bed. The studies carried out made it possible to establish the regimes of pseudo-fluidization, to a certain extent minimizing the heterogeneity of the layer, which is of significant practical importance. However, the operating parameters need to be adjusted depending on the type of material to be dried and other indicators. The research results do not obscure the general provisions of nonequilibrium thermodynamics. The fluidized bed cannot be in an equilibrium state, since the transfer of substances is obvious: energy, mass and momentum. It is correct to regard the fluidized bed as unstable. Small and spontaneous fluctuations always exist in the layer. The absence of conditions for their decay becomes a condition for the instability of the process.

scholarly journals Success factors for introducing industrial human-robot interaction in practice: an empirically driven framework

2020 ◽  
Author(s):  
Tobias Kopp ◽  
Marco Baumgartner ◽  
Steffen Kinkel
Keyword(s):  
Online Survey ◽  
Success Factors ◽  
Practical Importance ◽  
Human Robot Interaction ◽  
Free Text ◽  
Manufacturing Companies ◽  
Robot Interaction ◽  
Related Factors ◽  
Essential Components ◽  
The Impact

AbstractHuman-robot interaction (HRI) promises to be a means whereby manufacturing companies will be able to address current challenges like a higher demand for customization. However, despite comparably low costs, there are only few applications in practice. To date, it remains unclear which factors facilitate or hinder the successful introduction of industrial collaborative robots (cobots). In a three-step approach, we first developed a comprehensive two-dimensional framework covering three separate phases and four essential components for human-robot working systems. Secondly, we reviewed related literature to identify relevant success factors. Thirdly, in an online survey we asked leading representatives of German manufacturing companies (n = 81) to assess the importance of these factors from a practical point of view. The results reveal that besides technology-related factors like occupational safety and appropriate cobot configuration, employee-centered factors like the fear of job loss and ensuring an appropriate level of trust in the robot are considered important. However, company representatives seem to underestimate the impact of subtle measures to increase employee acceptance which could be incorporated into internal communication strategies prior to and during the introduction of cobots. Comparative analysis based on three distinct application scenarios suggests that most success factors’ practical importance is independent of the motivation for implementing HRI. Furthermore, answers from practitioners in free-text fields reveal that success factors which intuitively come to their mind such as financial factors are not necessarily perceived most important. Finally, we argue for more application-oriented research that focuses on practically relevant factors to guide HRI research, inform cobot development, and support companies in overcoming apparent barriers.

Contrasts of planar defects in reflection electron microscopy

1993 ◽  
Vol 51 ◽  
pp. 1004-1005
Author(s):  
Feng Tsai ◽  
J. M. Cowley
Keyword(s):  
Electron Microscopy ◽  
Surface Defects ◽  
Practical Importance ◽  
Theoretical Treatment ◽  
Crystal Surfaces ◽  
Planar Defects ◽  
Surface Steps ◽  
Surface Reconstructions ◽  
Domain Boundaries ◽  
Reflection Electron Microscopy

Reflection electron microscopy (REM) has been used to study surface defects such as surface steps, dislocations emerging on crystal surfaces, and surface reconstructions. However, only a few REM studies have been reported about the planar defects emerging on surfaces. The interaction of planar defects with surfaces may be of considerable practical importance but so far there seems to be only one relatively simple theoretical treatment of the REM contrast and very little experimental evidence to support its predications. Recently, intersections of both 90° and 180° ferroelectric domain boundaries with BaTiO3 crystal surfaces have been investigated by Tsai and Cowley with REM.The REM observations of several planar defects, such as stacking faults and domain boundaries have been continued by the present authors. All REM observations are performed on a JEM-2000FX transmission electron microscope. The sample preparations may be seen somewhere else. In REM, the incident electron beam strikes the surface of a crystal with a small glancing angle.

Voice Therapy With Seniors: Attendance, Outcomes, and Associated Patient Characteristics

2019 ◽  
Vol 4 (5) ◽  
pp. 814-824 ◽  
Author(s):  
Bonnie E. Smith ◽  
Ruth Huntley Bahr ◽  
Hector N. Hernandez
Keyword(s):  
Outcome Data ◽  
Voice Therapy ◽  
Similar Data ◽  
Success Rates ◽  
Reflux Symptom Index ◽  
Voice Change ◽  
Related Factors ◽  
Symptom Index ◽  
Younger Patients ◽  
Unsuccessful Treatment

Purpose The purpose of this study was to determine the attendance and success rates for seniors in voice therapy, identify any contributing patient-related factors, and compare results to existing findings for younger patients. Method This retrospective study included information from the voice records of 50 seniors seen by the same speech-language pathologist in a private practice. Analysis of attendance and outcome data divided participants into 6 groups. Outcomes for Groups 1–3 (64% of patients) were considered successful (positive voice change), while outcomes for Groups 4–6 (36% of patients) were considered unsuccessful. These data were compared to similar data collected for younger adults in a previous study. Results The attendance and success rates for seniors in this study were higher than those previously reported for younger patients. Further consideration of patient factors revealed that reports of increased stress, Reflux Symptom Index scores > 13, and higher Voice Handicap Index functional subscale scores were significant in distinguishing between patients in the successful and unsuccessful treatment outcome groups. Conclusions The relatively high attendance and success rates among this sample of seniors suggest the desire to achieve voice improvement does not diminish with age, and chances for success in voice therapy among nonfrail seniors may be greater than for younger patients.

Obstacles to Claiming Permanence and Injury-Relatedness for “Posttraumatic” Headache

2009 ◽  
Vol 14 (3) ◽  
pp. 3-6
Author(s):  
Robert J. Barth
Keyword(s):  
Complete Recovery ◽  
World Health ◽  
Related Factors ◽  
Posttraumatic Headache ◽  
Sixth Edition ◽  
Causative Relationship ◽  
Short Period ◽  
The One ◽  
Health Organization ◽  
Subjective Reports

Abstract “Posttraumatic” headaches claims are controversial because they are subjective reports often provided in the complex of litigation, and the underlying pathogenesis is not defined. This article reviews principles and scientific considerations in the AMAGuides to the Evaluation of Permanent Impairment (AMA Guides) that should be noted by evaluators who examine such cases. Some examples in the AMA Guides, Sixth Edition, may seem to imply that mild head trauma can cause permanent impairment due to headache. The author examines scientific findings that present obstacles to claiming that concussion or mild traumatic brain injury is a cause of permanent headache. The World Health Organization, for example, found a favorable prognosis for posttraumatic headache, and complete recovery over a short period of time was the norm. Other studies have highlighted the lack of a dose-response correlation between trauma and prolonged headache complaints, both in terms of the frequency and the severity of trauma. On the one hand, scientific studies have failed to support the hypothesis of a causative relationship between trauma and permanent or prolonged headaches; on the other hand, non–trauma-related factors are strongly associated with complaints of prolonged headache.

Striae Gravidarum, Vitamin C and Other Related Factors

2011 ◽  
Vol 81 (1) ◽  
pp. 43-48 ◽  
Author(s):  
Rahime Bedir Findik ◽  
Nurcihan Karakurt Hascelik ◽  
Kadir Okhan Akin ◽  
Ayse Nurcan Unluer ◽  
Jale Karakaya
Keyword(s):  
Family History ◽  
Vitamin C ◽  
Pregnant Women ◽  
Smoking Status ◽  
Multiple Logistic Regression Analysis ◽  
Blood Levels ◽  
Significant Relation ◽  
Related Factors ◽  
Thigh Circumference ◽  
Striae Gravidarum

Background: Striae gravidarum, a clinical condition commonly seen in pregnant women, produces serious cosmetic problems and may lead to psychological problems. Aim: The present study investigated whether there was any relation between the presence of striae in primigravid pregnant women and blood vitamin C levels, and factors thought to contribute to the formation of striae such as family history, weight gained during pregnancy, smoking status, abdominal and thigh circumference, and age. Methods: Overall, 69 primigravid women attending routine antenatal follow-up and, using prophylactic iron and vitamin preparations, underwent investigation. All were pregnant 36 or more weeks. Scoring was based on striae examination and whether striae were present. The relation between the presence of striae, vitamin C blood levels, and other factors was investigated. Results and Conclusions: Multiple logistic regression analysis showed a significant relation between the presence of striae and blood vitamin C levels (p = 0.046) and between the presence of striae and family history (p = 0.023). No significant relation was found between the presence of striae and age, weight gained during pregnancy, abdominal and thigh circumference, or smoking status. It was concluded that further, more comprehensive studies on the issue are required.

Root Cause Analyses of Suicides of Mental Health Clients

Crisis ◽  
2015 ◽  
Vol 36 (5) ◽  
pp. 316-324 ◽  
Author(s):  
Donna Gillies ◽  
David Chicop ◽  
Paul O'Halloran
Keyword(s):  
Mental Health ◽  
Suicide Prevention ◽  
Common Factor ◽  
Data Collection Tool ◽  
Related Factors ◽  
Root Cause ◽  
Communication Problems ◽  
The Individual ◽  
Mental Health Clients ◽  
Imminent Risk

Abstract. Background: The ability to predict imminent risk of suicide is limited, particularly among mental health clients. Root cause analysis (RCA) can be used by health services to identify service-wide approaches to suicide prevention. Aims: To (a) develop a standardized taxonomy for RCAs; (b) to quantitate service-related factors associated with suicides; and (c) to identify service-related suicide prevention strategies. Method: The RCAs of all people who died by suicide within 1 week of contact with the mental health service over 5 years were thematically analyzed using a data collection tool. Results: Data were derived from RCAs of all 64 people who died by suicide between 2008 and 2012. Major themes were categorized as individual, situational, and care-related factors. The most common factor was that clients had recently denied suicidality. Reliance on carers, recent changes in medication, communication problems, and problems in follow-through were also commonly identified. Conclusion: Given the difficulty in predicting suicide in people whose expressions of suicidal ideation change so rapidly, services may consider the use of strategies aimed at improving the individual, stressor, support, and care factors identified in this study.

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