Systematic Analysis of the Impact of Bump Height Manufacturing Errors on the Unbalance Response of a Foil Journal Bearing

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Omar Benchekroun ◽  
Mihai Arghir
Keyword(s):  
Degrees Of Freedom ◽  
Journal Bearing ◽  
Systematic Analysis ◽  
Mean Values ◽  
Bump Height ◽  
Unbalance Response ◽  
Machining Errors ◽  
Manufacturing Errors ◽  
The Mean ◽  
The Impact

Abstract The present work exhibits the numerical investigation of the bump height-manufacturing errors on the unbalance response of an aerodynamic foil journal bearing. This is the first study on the impact of manufacturing errors based on an important number of samples. A statistical analysis predicts the mean values of the characteristics and the standard errors of the mean. The paper presents the most important aspects of the numerical model that was used and the way it was implemented for the unbalance analysis of a four degrees-of-freedom rotor. It was considered that the bump height-manufacturing errors had a normal distribution (i.e., each bump had a different random height) around the design (mean) height value. The standard deviation of the bump heights (the same for all bumps) is a measure of the magnitude of the manufacturing errors. The results give a qualitative but above all quantitative overview of the impact of machining errors on some characteristics of aerodynamic foil bearings.

scholarly journals Biases in CloudSat Falling Snow Estimates Resulting from Daylight-Only Operations

2021 ◽  
Vol 13 (11) ◽  
pp. 2041
Author(s):  
Lisa Milani ◽  
Norman B. Wood
Keyword(s):  
Water Cycle ◽  
Mean Values ◽  
The Mean ◽  
Satellite Missions ◽  
The Impact ◽  
Global Mean

Falling snow is a key component of the Earth’s water cycle, and space-based observations provide the best current capability to evaluate it globally. The Cloud Profiling Radar (CPR) on board CloudSat is sensitive to snowfall, and other satellite missions and climatological models have used snowfall properties measured by it for evaluating and comparing against their snowfall products. Since a battery anomaly in 2011, the CPR has operated in a Daylight-Only Operations (DO-Op) mode, in which it makes measurements primarily during only the daylit portion of its orbit. This work provides estimates of biases inherent in global snowfall amounts derived from CPR measurements due to this shift to DO-Op mode. We use CloudSat’s snowfall measurements during its Full Operations (Full-Op) period prior to the battery anomaly to evaluate the impact of the DO-Op mode sampling. For multi-year global mean values, the snowfall fraction during DO-Op changes by −10.16% and the mean snowfall rate changes by −8.21% compared with Full-Op. These changes are driven by the changes in sampling in DO-Op and are very little influenced by changes in meteorology between the Full-Op and DO-Op periods. The results highlight the need to sample consistently with the CloudSat observations or to adjust snowfall estimates derived from CloudSat when using DO-Op data to evaluate other precipitation products.

​Impact of Extreme Hot Environmental Temperature Period on Marker Enzymes of Carbohydrate Metabolism in Non-descript Sheep from Arid Tracts of Rajasthan

2021 ◽  
Author(s):  
Anandita Srivastava ◽  
Nalini Kataria
Keyword(s):  
Carbohydrate Metabolism ◽  
Environmental Temperature ◽  
Age Groups ◽  
Extreme Temperature ◽  
Mean Value ◽  
Marker Enzymes ◽  
Mean Values ◽  
The Mean ◽  
The Impact ◽  
Enzymes Of Carbohydrate Metabolism

Background: The present investigation was envisaged to find out the impact of extreme hot environmental temperature period (ETP) on marker enzymes of carbohydrate metabolism in male and female non-descript sheep of various age groups i.e. 4 to 13 months from arid tracts of Rajasthan. Glucose-6-phosphate dehydrogenase (G-6-PDH) and malate dehydrogenase (MDH) marker enzymes of carbohydrate metabolism were considered for study. Methods: During the period October 2016-June 2017 blood samples were collected to harvest sera for spectrophotometric method from 240 healthy animals selected from private slaughter house during moderate and extreme hot environmental temperature periods (ETPs). The mean values of markers attained during moderate ETP were reckoned as the control. It was 10.00 ± 0.10 UL-1 and 42.00±1.00 respectively. Conclusion: The mean value of MDH was significantly (p≤0.05) higher while G-6-PDH significantly (p≤0.05) lowers during extreme hot temperature in comparison to moderate period. Therefore, it could be concluded that variations in enzyme markers were associated with changes in environmental temperatures. Probably ETP were able to produce a profound effect on carbohydrate metabolism in sheep. Therfore it can be suggested that during the period of extreme temperature balanced ration must be provided to the animal along with proper management to decrease the severity of temperature impact.

AC0-nonconforming quadrilateral finite element for the fourth-order elliptic singular perturbation problem

2018 ◽  
Vol 52 (5) ◽  
pp. 1981-2001 ◽  
Author(s):  
Yuan Bao ◽  
Zhaoliang Meng ◽  
Zhongxuan Luo
Keyword(s):  
Singular Perturbation ◽  
Fourth Order ◽  
Degrees Of Freedom ◽  
Perturbation Parameter ◽  
Singular Perturbation Problem ◽  
Mean Values ◽  
Perturbation Problem ◽  
Convex Quadrilateral ◽  
The Mean ◽  
Quadrilateral Finite Element

In this paper, aC0nonconforming quadrilateral element is proposed to solve the fourth-order elliptic singular perturbation problem. For each convex quadrilateralQ, the shape function space is the union ofS21(Q*) and a bubble space. The degrees of freedom are defined by the values at vertices and midpoints on the edges, and the mean values of integrals of normal derivatives over edges. The local basis functions of our element can be expressed explicitly by a new reference quadrilateral rather than by solving a linear system. It is shown that the method converges uniformly in the perturbation parameter. Lastly, numerical tests verify the convergence analysis.

scholarly journals Records of performance and sanitary status from a dairy cattle herd in southern Brazil

2011 ◽  
Vol 31 (1) ◽  
pp. 01-09 ◽  
Author(s):  
Cláudio E. F. Cruz ◽  
Djeison L. Raymundo ◽  
Cristine Cerva ◽  
Saulo P. Pavarini ◽  
André G. C. Dalto ◽  
...  
Keyword(s):  
Dairy Cattle ◽  
Reproductive Performance ◽  
Cattle Herd ◽  
Lactation Period ◽  
Mean Values ◽  
Cattle Diseases ◽  
Dairy Cattle Herd ◽  
The Mean ◽  
The Impact ◽  
Voluntary Waiting Period

Over the last decades, the emphasis on the health of dairy cows has changed from an individual to a herd level. In this scenario, the role played by the recording system and its interpretation by veterinarians has gained primordial importance. The records of productive and reproductive performance and of sanitary status from a southern Brazilian dairy cattle herd have been presented and discussed. The period of study was 2000-2009. Mean values per lactation period were 349D 8436M 290F 275P 201SCS (D: days in lactation, M: kg of milk yield, F: kg of fat, P: kg of protein and SCS: somatic cell score in 1000 cells/ml of milk). Major indexes of reproductive efficiency included age at first calving (31 months), services per conception (2.1), intercalving interval (428 days), calving to conception interval (146 days), mean annual rates of parturitions (76.2%), fetal losses (9.8-19.0%), and stillbirths (3.6%), apart of voluntary waiting period (94 days). Main information on sanitary status of the herd was associated with the mean prevalence of common disorders of dairy cattle such as anaplasmosis (29.8%), mastitis (27.8%), digital diseases (26.3%), ovarian cysts (21.3%), placental retention (19.7%), postpartum uterine infections (10.6%), and calf diarrhea (23.7%) and pneumonia (16.8%), among others. In addition, culling reasons (low reproductive performance [56.3%] and udder/mastitis problems [33.6%]), causes of cattle deaths (anaplasmosis [16.4%] and leukosis [11.4]), and the impact of cattle diseases such as tuberculosis, leukosis, and neosporosis on the herd have also been presented and succinctly discussed. Numbers between brackets represent rates accumulated in the 10-year period.

scholarly journals Ultrasound-based examination of the medial ligament complex shows gender- and age-related differences in laxity

2020 ◽  
Author(s):  
Patricia M. Lutz ◽  
Matthias J. Feucht ◽  
Judith Wechselberger ◽  
Michael Rasper ◽  
Wolf Petersen ◽  
...  
Keyword(s):  
Knee Joint ◽  
Knee Flexion ◽  
Joint Space ◽  
Medial Knee ◽  
Mean Values ◽  
Age Related ◽  
Gender And Age ◽  
Joint Width ◽  
The Mean ◽  
The Impact

Abstract Purpose Ultrasound (US) examination of the medial joint space of the knee has played a subordinate diagnostic role up till now. The purpose of the present study was to describe mean values of medial joint width and to investigate the impact of gender, age, and body mass index (BMI) on medial joint laxity in healthy knees using modern, dynamic US in a standardized fashion in unloaded and standardized loaded conditions. Methods A total of 65 subjects with 79 healthy knees were enrolled in this study. All volunteers underwent clinical examination of the knee. The medial knee joint width was determined using US in a supine position at 0° and 30° of knee flexion in unloaded and standardized loaded (= 15 Dekanewton, daN) conditions using a specific device. Mean values were described and correlations between medial knee joint width and gender, age, and BMI were assessed. Results Thirty-two females and 33 males were enrolled in this study. The mean medial joint width in 0° unloaded was 5.7 ± 1.2 mm and 7.4 ± 1.4 mm loaded. In 30° of knee flexion, the mean medial joint width was 6.1 ± 1.1 mm unloaded and 7.8 ± 1.2 mm loaded. The average change between unloaded and loaded conditions in 0° was 1.7 ± 1.0 mm and in 30° 1.7 ± 0.9 mm. A significant difference between genders was evident for medial joint width in 0° and 30° of flexion in unloaded and loaded conditions (p < 0.05). With rising age, a significant increased change of medial joint space width between unloaded and loaded conditions could be demonstrated in 0° (p = 0.032). No significant correlation between BMI and medial joint width in US could be found. Conclusion Mean values of medial joint width in unloaded and standardized loaded conditions using a fixation device could be demonstrated. Based on the results of this study, medial knee joint width in US is gender- and age-related in healthy knees. These present data may be useful for evaluating patients with acute or chronic pathologies to the medial side of the knee. Level of evidence III.

Discordant GH and IGF-1 Results in Treated Acromegaly: Impact of GH Cutoffs and Mean Values Assessment

2020 ◽  
Author(s):  
Claudia Campana ◽  
Francesco Cocchiara ◽  
Giuliana Corica ◽  
Federica Nista ◽  
Marica Arvigo ◽  
...  
Keyword(s):  
Characteristic Curve ◽  
Area Under The Curve ◽  
Receiver Operator Characteristic Curve ◽  
Mean Values ◽  
Pituitary Diseases ◽  
Discordance Rate ◽  
Values Assessment ◽  
The Mean ◽  
The Impact

Abstract Context Discordant growth hormone (GH) and insulin-like growth factor-1 (IGF-1) values are frequent in acromegaly. Objective To evaluate the impact of different GH cutoffs on discordance rate. To investigate whether the mean of consecutive GH measurements impacts discordance rate when matched to the last available IGF-1 value. Design Retrospective study. Setting Referral center for pituitary diseases. Patients Ninety acromegaly patients with at least 3 consecutive evaluations for GH and IGF-1 using the same assay in the same laboratory (median follow-up 13 years). Interventions Multimodal treatment of acromegaly. Main Outcome Measures Single fasting GH (GHf) and IGF-1 (IGF-1f). Mean of 3 GH measurements (GHm), collected during consecutive routine patients’ evaluations. Results At last evaluation GHf values were 1.99 ± 2.79 µg/L and age-adjusted IGF-1f was 0.86 ± 0.44 × upper limit of normality (mean ± SD). The discordance rate using GHf was 52.2% (cutoff 1 µg/L) and 35.6% (cutoff 2.5 µg/L) (P = 0.025). “High GH” discordance was more common for GHf &lt;1.0 µg/L, while “high IGF-1” was predominant for GHf &lt;2.5 µg/L (P &lt; 0.0001). Using GHm mitigated the impact of GH cutoffs on discordance (GHm &lt;1.0 µg/L: 43.3%; GHm &lt;2.5 µg/L: 38.9%; P = 0.265). At receiver-operator characteristic curve (ROC) analysis, both GHf and GHm were poor predictors of IGF-1f normalization (area under the curve [AUC] = 0.611 and AUC = 0.645, respectively). The prevalence of disease-related comorbidities did not significantly differ between controlled, discordant, and active disease patients. Discussion GH/IGF-1 discordance strongly depends on GH cutoffs. The use of GHm lessen the impact of GH cutoffs. Measurement of fasting GH levels (both GHf and GHm) is a poor predictor of IGF-1f normalization in our cohort.

scholarly journals Analysis of a Discrete-Time Queueing Model with Disasters

Mathematics ◽  
2021 ◽  
Vol 9 (24) ◽  
pp. 3283
Author(s):  
Mustafa Demircioglu ◽  
Herwig Bruneel ◽  
Sabine Wittevrongel
Keyword(s):  
Discrete Time ◽  
Queueing System ◽  
Time Slot ◽  
Probability Distributions ◽  
Single Server ◽  
Bernoulli Process ◽  
Tail Probabilities ◽  
Mean Values ◽  
The Mean ◽  
The Impact

Queueing models with disasters can be used to evaluate the impact of a breakdown or a system reset in a service facility. In this paper, we consider a discrete-time single-server queueing system with general independent arrivals and general independent service times and we study the effect of the occurrence of disasters on the queueing behavior. Disasters occur independently from time slot to time slot according to a Bernoulli process and result in the simultaneous removal of all customers from the queueing system. General probability distributions are allowed for both the number of customer arrivals during a slot and the length of the service time of a customer (expressed in slots). Using a two-dimensional Markovian state description of the system, we obtain expressions for the probability, generating functions, the mean values, variances and tail probabilities of both the system content and the sojourn time of an arbitrary customer under a first-come-first-served policy. The customer loss probability due to a disaster occurrence is derived as well. Some numerical illustrations are given.

Photometric results of the long-term monitoring of the active asteroid (596) Scheila

2020 ◽  
Author(s):  
Zhong-Yi Lin ◽  
Chen-Yen Hsu
Keyword(s):  
Light Curve ◽  
Rotation Period ◽  
Impact Event ◽  
Mean Values ◽  
Photometric Observations ◽  
The Mean ◽  
The Difference ◽  
The Impact ◽  
Term Monitoring

&lt;p&gt;(596) Scheila was observed to have an active appearance as a result of impact event in late 2010. In additional the coma feature, the shape of light curve had been found the difference probably fresh material or surface properties changed around the impact site. In this study, we present the results of our monitoring observations obtained in 2014 and 2019-2020. The mean values of the color indices (B&amp;#8722;V&amp;#160;= (0.75 &amp;#177; 0.08)&lt;sup&gt;m&lt;/sup&gt;,&amp;#160;V&amp;#8722;R&amp;#160;= (0.45 &amp;#177; 0.04)&lt;sup&gt;m&lt;/sup&gt;, and&amp;#160;R&amp;#8722;I&amp;#160;= (0.44 &amp;#177; 0.09)&lt;sup&gt;m&lt;/sup&gt;) agree well with the values for asteroids of the D-types. The rotation period of the asteroid estimated from photometric observations in 2014 is 15.8 &amp;#177; 0.1 h.&amp;#160;The shape of the light curve is similar as that found after impact event. Furthermore, we did not find any rotational color variability in B-V, V-R and R-I diagrams, meaning the observed surface in this observing period of 2019-2020 is homogeneous.&lt;/p&gt;

Mechanical Damage to Pinto Bean Seeds as Affected by Moisture Content, Impact Velocity and Seed Orientation

2012 ◽  
Vol 7 (6) ◽  
Author(s):  
Feizollah Shahbazi ◽  
Mohamad Analooei ◽  
Ali Saffar
Keyword(s):  
Moisture Content ◽  
Impact Velocity ◽  
Impact Damage ◽  
Quadratic Function ◽  
Physical Damage ◽  
Seed Moisture Content ◽  
Mean Values ◽  
Pinto Bean ◽  
The Mean ◽  
The Impact

The objective of this experiment was evaluate of the impact damage to pinto bean seeds where seed moisture content (9.25, 12.51, 15.01, 17.52, 20.01% wet basis), impact velocity (5.5, 8, 10, 12.5 and 15m/s) and seed orientation (end and side) were independent variables. The study was conducted under laboratory conditions, using an impact damage assessment device. The results showed that impact velocity, moisture content and seed orientation significantly influenced the physical damages of pinto beans at 1% level. Increasing the impact velocity from 5.5 to 15m/s caused an increase in the mean values of damage from 0.39 to 37.30%. With increase the moisture content from 9.25 to 17.52%, the mean values of percentage of damaged beans decreased significantly from 41.24 to 4.27%. However, by a higher increase in the moisture from 17.52 to 20.01%, the mean values of physically damaged beans showed a nonsignificant increasing trend. There was an optimum moisture level of 17.52% at which seed damage was minimized. The relationship between the percent of physical damage with impact velocity and beans moisture content was expressed mathematically. It was found that the percentage damage to seeds was a quadratic function of moisture content and impact velocity. Impact to the end of the seeds (18.62%) produced the higher damage than side orientation (13.12%).

Constitutional Frameworks and Democratic Consolidation: Parliamentarianism versus Presidentialism

1993 ◽  
Vol 46 (1) ◽  
pp. 1-22 ◽  
Author(s):  
Alfred Stepan ◽  
Cindy Skach
Keyword(s):  
Degrees Of Freedom ◽  
Chief Executive ◽  
Democratic Consolidation ◽  
Military Coup ◽  
Interactive System ◽  
Political Society ◽  
Systematic Analysis ◽  
Party Government ◽  
The Impact ◽  
Different Sources

A fundamental political-institutional question that has only recently received serious scholarly attention concerns the impact of different constitutional frameworks on democratic consolidation. Little systematic cross-regional evidence has been brought to bear on this question. This article reports the findings of the analysis of numerous different sources of data, all of which point in the direction of a much stronger correlation between democratic consolidation and the constitutional framework of pure parliamentarianism than between consolidation and pure presidentialism. The systematic analysis of these data leads the authors to conclude that parliamentarianism is a more supportive constitutional framework due to the following theoretically predictable and empirically observable tendencies: its greater propensity for governments to have majorities to implement their programs, its greater ability to rule in a multiparty setting, its lower propensity for executives to rule at the edge of the constitution and its greater facility in removing a chief executive if he or she does so, its lower susceptibility to a military coup, and its greater tendency to provide long party-government careers, which add loyalty and experience to political society. In contrast, the analytically separable propensities of presidentialism also form a highly interactive system, but they work to impede democratic consolidation by reducing politicians' degrees of freedom.

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