Effect of Pore Ensemble Statistics on Load Support of Mechanical Seals With Pore-Covered Faces

1999 ◽  
Vol 121 (4) ◽  
pp. 927-932 ◽  
Author(s):  
Leonid Burstein ◽  
Dov Ingman
Keyword(s):  
Control Cell ◽  
Size Variation ◽  
Hydrodynamic Pressure ◽  
Mean Value ◽  
Mechanical Seals ◽  
Load Carrying ◽  
Size Diversity ◽  
The Difference ◽  
The One ◽  
First Time

A mathematical model was developed for predicting the performance of laser-textured seals with pores. A solution of the two-dimensional steady-state Reynolds equation was given for rectangular and exponential pores, as well as expressions for the hydrodynamic pressure distribution over the control cell and for the cell load support. The difference between the two pore shapes can be reduced from a factor of multiple times to 30 percent at most—if the pore volume is kept constant. It was also shown that the total hydrodynamically induced load-carrying capacity can be obtained with accuracy, even if the pore radius of the seal surface is assumed to vary over a wide interval about its mean value, as it does in reality. Diameters in an ensemble of over 4 · 104 pores were run at random for 500 seal faces. It was established for the first time that load support of an ensemble exceeds by 22 percent the one determined for N identical pores. The model for the entire pore population as an ensemble with size variation is more realistic, and substantiates the possibilities and advisability of pore size diversity, hitherto considered undesirable in the pore production process. In general, the pore ensemble is an essential aspect in exact determination of the load support and better insight into the tribologic behavior of pore-covered surfaces.

scholarly journals The Optimal Control of Government Stabilization Funds

Mathematics ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1975
Author(s):  
Abel Cadenillas ◽  
Ricardo Huamán-Aguilar
Keyword(s):  
Optimal Control ◽  
Public Debt ◽  
Government Programs ◽  
Fund Manager ◽  
Running Cost ◽  
The Difference ◽  
The Government ◽  
The One ◽  
First Time

We study the optimal control of a government stabilization fund, which is a mechanism to save money during good economic times to be used in bad economic times. The objective of the fund manager is to keep the fund as close as possible to a predetermined target. Accordingly, we consider a running cost associated with the difference between the actual fiscal fund and the fund target. The fund manager exerts control over the fund by making deposits in or withdrawals from the fund. The withdrawals are used to pay public debt or to finance government programs. We obtain, for the first time in the literature, the optimal band for the government stabilization fund. Our results are of interest to practitioners. For instance, we find that the higher the volatility, the larger the size of the optimal band. In particular, each country and state should have its own optimal fund band, in contrast to the “one-size-fits-all” approach that is often used in practice.

scholarly journals III. On the uneliminated instrumental error in the observations of magnetic dip

1869 ◽  
Vol 17 ◽  
pp. 427-429
Keyword(s):  
Mean Value ◽  
Usual Method ◽  
Centre Of Gravity ◽  
Single Reading ◽  
The Mean ◽  
The Difference ◽  
The One ◽  
Number Of Passes ◽  
Source Of Error ◽  
Complete Observation

A single reading of one end of a dipping-needle placed in a dip-circle provided with microscopes for observing is liable to a variety of instrumental errors, which are eliminated by taking the mean of the sixteen readings of the two ends in the eight different positions included in a complete observation. Nevertheless it is found that with the best modern instruments a mean value results from these sixteen observations different for each different needle, and that the difference between the results obtained with two different needles is not the same at all times. The irregularities in the values of the dip observed at Bombay with two needles of excellent character made by Barrow of London, led the author to investigate the effect of a hypothetical irregularity in the shape of the axle of the needle, such that a section of the axle by a plane perpendicular to its axis would be elliptical instead of circular in form. Another source of error, which was brought to the notice of the Royal Society many years ago in a paper published in the Proceedings, is the displacement of the centre of gravity of the needle from the centre of the axle, combined with inequality in the magnetization of the needle when the poles are direct and reversed. Experience has led the author to the conclusion that the usual method of magnetization, by a definite number of passes of the same pair of bar-magnets, communicates magnetism to the needle very unequally when the one end of the needle is made north and when the other end is made north. Consequently it is advisable to investigate the effects of ellipticity of the axle and of displacement of the centre of gravity at the same time, which the author proceeds to do.

Knowledge on COVID 19 among the healthcare professionals in South Indian states

2020 ◽  
Vol 11 (SPL1) ◽  
pp. 983-989
Author(s):  
Deepalakshmi M ◽  
Ajay Samraj P ◽  
Vijay V ◽  
Jonna Venkatesh ◽  
Kamal Rathinam RS ◽  
...  
Keyword(s):  
Healthcare Workers ◽  
Online Survey ◽  
Statistical Significance ◽  
Mean Value ◽  
Indian States ◽  
Study Region ◽  
South Indian ◽  
National Organizations ◽  
The Difference ◽  
The One

As the COVID-19 has become a pandemic across the globe, the knowledge of healthcare workers (HCWs) about the diseases and its management is very vital to have a better control over the infection. This study was carried out to assess the knowledge of HCWs of the 5 south Indian states with higher rates of COVID-19 infection. An online survey with 25 validated questions about COVID-19 was administered to 385 HCWs across the study region. Prior to the administration, the questionnaire was validated for various standard parameters using Cronbach’s alpha score greater than 0.7. The responses were analyzed using descriptive statistics and statistical significance was assessed using one-way ANOVA.p value of less than 0.05 was considered to be statistically significant. The overall knowledge about COVID-19 was found to be greater among the medical doctors, pharmacists and nurses from higher to lower scores with a mean value of78.81±13.45 compared to the other healthcare workers 63.6±24.3. The one-way ANOVA revealed that the difference in the knowledge levels among the HCWs significantly differed (p=0.0012). The answers to few of the questions were found to be highly dynamic as the advisory guidelines are highly dynamic. The present knowledge level of HCWs in south India about COVID-19 is relatively high. However, there is a need for continuous education about COVID-19 to the HCWs and the national organizations and authorities should provide a structured and reliable information to the HCWs in order to have a better control over the COVID-19 infection.

scholarly journals Verbalisation of the image of man in the English and Lak languages

2019 ◽  
Vol 10 (4) ◽  
Author(s):  
Mariana Abakarova
Keyword(s):  
Way Of Life ◽  
Thematic Layers ◽  
The Past ◽  
Key Factor ◽  
Geographical Position ◽  
The Difference ◽  
The One ◽  
First Time ◽  
English Culture ◽  
The Ideal

The article analyses English and Lak proverbs describing a man. Proverbs have been chosen as a material of study due to the fact that they are the entities revealing the mentality of a certain ethnic group. The author was compelled to conduct this study owing to the current lack of research in the area of Lak proverbs. The novelty of the article lies in the fact that for the first time it has provided a psychological portrait of a man on the basis of the English and Lak languages. Isolated geographical position of Lak and English people was the cause of their inclination for conservative way of life which resulted in the formation of certain stereotypes of a Lak and an Englishman. The aim of the author was to discover those stereotypes by means of detecting universal and specific traits of Lak and English people. To reach that aim the author grouped the proverbs in thematic layers and provided them with linguocultural commentary. The image of man consists of such characteristics as reliability or unreliability, reserve or verbosity, valiancy or cowardice, ability or inability to fight, patience or impatience and love of food. The analysis showed that the ideal man in both Lak and English culture is the one who is patient, restrained and able to defend himself and his family, including the situation on the battlefield. The difference between the Lak and the English appeared in the degree of man’s readiness to fight. For the Laks whose life in the past was passing between wars the key factor was their ability to wage war while the English are more reserved and cautious in their actions.

scholarly journals Law and religion in “Martian the Lawyer”, the dramatic poem by Lesia Ukrainka

2021 ◽  
pp. 39-55
Author(s):  
Tetyana Dagovych
Keyword(s):  
Early Christianity ◽  
Roman Law ◽  
Third Century ◽  
Human Beings ◽  
Christian Community ◽  
Law Of Nature ◽  
The Difference ◽  
The One ◽  
First Time ◽  
Christian Leaders

The paper explains the attitudes towards law and religion in Lesia Ukrainka’s dramatic poem “Martian the Lawyer” (1911). The poem depicts the life of early Christians under the Roman law in the third century and obtains new relevance in the context of the movement ‘Law and Literature’, as the focus on law in this oeuvre allows a deeper exploration of its meaning. Law is connected with religion in two ways in the poem: as a part of the civil religion and as a system of prohibitions and punishments within the Christian community. Analysis of the text shows that Martian is a carrier of a sophisticated religious form, which implies the juridical elements codified in early Christianity, as well as a belief in law as the incarnation of the idea of truth and justice. The two antagonistic social and spiritual systems – early Christianity and the Roman law – fuse into one ideology that consumes the life of the protagonist. The difference between the juridical laws, the law of nature, and the commandments of Christian leaders disappears within this religious form. In the house of the hero, only those things that represent time or law remain, such as different types of timepieces and juridical texts; Martian’s home becomes a place for abstract ideas, but not for human beings with their needs and feelings. For the protagonist, there are no conflicts between law and religion, but there is a conflict between early Christianity and the Roman law on the one side and, on the other side, human compassion, which is supposed to be a crucial idea within Christianity but is not practiced in the local Christian community. Because of this conflict, Martian completely loses contact with human feelings and becomes an ideal lawyer, which is beneficial for his Christian community but tragic for himself and his relatives. This development signifies not only a sacrifice but also the full realization of Martian’s talent (Ukrainian: ‘khyst’). In some episodes within other poems by Lesia Ukrainka, law and religion are presented as intertwined or undifferentiated, but in “Martian the Lawyer” the author for the first time elaborates this issue thoroughly and creates an ambivalent and sophisticated dramatic situation.

scholarly journals TWO PERSPECTIVES ON THE ACT ON MUSEUMS

Muzealnictwo ◽  
2021 ◽  
Vol 62 ◽  
pp. 254-257
Author(s):  
Alicja Jagielska-Burduk ◽  
Piotr Stec
Keyword(s):  
Cultural Heritage ◽  
Legal Protection ◽  
The Other ◽  
Historic Monuments ◽  
The Difference ◽  
The One ◽  
Administrative Proceedings ◽  
First Time

In the paper the analysis of two newly published commentaries (2021) on the Act on Museums is conducted: the first commentary by A. Barbasiewicz, a lawyer specializing in cultural heritage, and the other by a team of scholars: Z. Cieślik, I. Gredka-Ligarska, P. Gwoździewicz- -Matan, I. Lipowicz, A. Matan, K. Zeidler specializing in administrative proceedings and legal protection of historic monuments. Both publications represent various perspectives on the same issue, thus complementing one another. The difference in the approach makes them both useful to experienced practitioners on the one hand and those who happen to confront these topics for the first time one the other. Importantly, both have been written in a clear language comprehensible to non-lawyers. Their high-rating cannot be diminished by the few critical remarks formulated in the paper.

Use of a Lyophilized Reference Plasma to Compare Coagulation Test Procedures

1975 ◽  
Vol 34 (02) ◽  
pp. 426-444 ◽  
Author(s):  
J Kahan ◽  
I Nohén
Keyword(s):  
Oral Anticoagulant Therapy ◽  
Repeated Measurements ◽  
Test Procedures ◽  
Coagulation Activity ◽  
Close Relationship ◽  
Measured Activity ◽  
Test Materials ◽  
The Difference ◽  
The Stability ◽  
The One

SummaryIn 4 collaborative trials, involving a varying number of hospital laboratories in the Stockholm area, the coagulation activity of different test materials was estimated with the one-stage prothrombin tests routinely used in the laboratories, viz. Normotest, Simplastin-A and Thrombotest. The test materials included different batches of a lyophilized reference plasma, deep-frozen specimens of diluted and undiluted normal plasmas, and fresh and deep-frozen specimens from patients on long-term oral anticoagulant therapy.Although a close relationship was found between different methods, Simplastin-A gave consistently lower values than Normotest, the difference being proportional to the estimated activity. The discrepancy was of about the same magnitude on all the test materials, and was probably due to a divergence between the manufacturers’ procedures used to set “normal percentage activity”, as well as to a varying ratio of measured activity to plasma concentration. The extent of discrepancy may vary with the batch-to-batch variation of thromboplastin reagents.The close agreement between results obtained on different test materials suggests that the investigated reference plasma could be used to calibrate the examined thromboplastin reagents, and to compare the degree of hypocoagulability estimated by the examined PIVKA-insensitive thromboplastin reagents.The assigned coagulation activity of different batches of the reference plasma agreed closely with experimentally obtained values. The stability of supplied batches was satisfactory as judged from the reproducibility of repeated measurements. The variability of test procedures was approximately the same on different test materials.

Reliability of a Single β-Thromboglobulin Measurement in a Diabetic Population : Importance of PGE1 in Anticoagulant Mixture

1987 ◽  
Vol 57 (02) ◽  
pp. 201-204 ◽  
Author(s):  
P Y Scarabin ◽  
L Strain ◽  
C A Ludlam ◽  
J Jones ◽  
E M Kohner
Keyword(s):  
In Vitro Release ◽  
Mean Value ◽  
Reliable Estimate ◽  
Diabetic Patients ◽  
Single Measurement ◽  
Diabetic Population ◽  
The Difference ◽  
Vitro Release

SummaryDuring the collection of samples for plasma β-thromboglobulin (β-TG) determination, it is well established that artificially high values can be observed due to in-vitro release. To estimate the reliability of a single β-TG measurement, blood samples were collected simultaneously from both arms on two separate occasions in 56 diabetic patients selected for a clinical trial. From each arm, blood was taken into two tubes containing an anticoagulant mixture with (tube A) and without (tube B) PGE!. The overall mean value of B-TG in tube B was 1.14 times higher than in tube A (p <0.01). The markedly large between-arms variation accounted for the most part of within-subject variation in both tubes and was significantly greater in tube B than in tube A. Based on the difference between B-TG values from both arms, the number of subjects with artifically high B-TG values was significantly higher in tube B than in tube A on each occasion (overall rate: 28% and 14% respectively). Estimate of between-occasions variation showed that B-TG levels were relatively stable for each subject between two occasions in each tube. It is concluded that the use of PGEi decreases falsely high B-TG levels, but a single measurement of B-TG does not provide a reliable estimate of the true B-TG value in vivo.

The Demand For Money in Pakistan: Reply (Notes and Comments)

1975 ◽  
Vol 14 (3) ◽  
pp. 370-375
Author(s):  
M. A. Akhtar
Keyword(s):  
Interest Rates ◽  
Money Demand ◽  
Strong Support ◽  
Physical Capital ◽  
Careful Examination ◽  
Demand For Money ◽  
Weak Support ◽  
Complementarity Hypothesis ◽  
The Difference ◽  
The One

I am grateful to Abe, Fry, Min, Vongvipanond, and Yu (hereafter re¬ferred to as AFMVY) [1] for obliging me to reconsider my article [2] on the demand for money in Pakistan. Upon careful examination, I find that the AFMVY results are, in parts, misleading and that, on the whole, they add very little to those provided in my study. Nevertheless, the present exercise as well as the one by AFMVY is useful in that it furnishes us with an opportunity to view some of the fundamental problems involved in an empi¬rical analysis of the demand for money function in Pakistan. Based on their elaborate critique, AFMVY reformulate the two hypo¬theses—the substitution hypothesis and the complementarity hypothesis— underlying my study and provide us with some alternative estimates of the demand for money in Pakistan. Briefly their results, like those in my study, indicate that income and interest rates are important in deter¬mining the demand for money. However, unlike my results, they also suggest that the price variable is a highly significant determinant of the money demand function. Furthermore, while I found only a weak support for the complementarity between money demand and physical capital, the results obtained by AFMVY appear to yield a strong support for that rela¬tionship.1 The difference in results is only a natural consequence of alter¬native specifications of the theory and, therefore, I propose to devote most of this reply to the criticisms raised by AFMVY and the resulting reformulation of the two mypotheses.

Effect of leakage and blockage on the acoustic behavior of particle filters

2019 ◽  
Vol 67 (6) ◽  
pp. 483-492
Author(s):  
Seonghyeon Baek ◽  
Iljae Lee
Keyword(s):  
Transfer Matrix ◽  
Particle Filters ◽  
Acoustic Analysis ◽  
Transmission Loss ◽  
One Dimensional ◽  
Filter System ◽  
The Difference ◽  
The One ◽  
Analytical Approaches ◽  
Good Agreement

The effects of leakage and blockage on the acoustic performance of particle filters have been examined by using one-dimensional acoustic analysis and experimental methods. First, the transfer matrix of a filter system connected to inlet and outlet pipes with conical sections is measured using a two-load method. Then, the transfer matrix of a particle filter only is extracted from the experiments by applying inverse matrices of the conical sections. In the analytical approaches, the one-dimensional acoustic model for the leakage between the filter and the housing is developed. The predicted transmission loss shows a good agreement with the experimental results. Compared to the baseline, the leakage between the filter and housing increases transmission loss at a certain frequency and its harmonics. In addition, the transmission loss for the system with a partially blocked filter is measured. The blockage of the filter also increases the transmission loss at higher frequencies. For the simplicity of experiments to identify the leakage and blockage, the reflection coefficients at the inlet of the filter system have been measured using two different downstream conditions: open pipe and highly absorptive terminations. The experiments show that with highly absorptive terminations, it is easier to see the difference between the baseline and the defects.

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