Experimental Study on the Wear-in Behaviour of Brush Seals

Volume 7C: Heat Transfer ◽

10.1115/gt2020-14158 ◽

2020 ◽

Author(s):

Manuel Hildebrandt ◽

Oliver Munz ◽

Corina Schwitzke ◽

Hans-Jörg Bauer

Keyword(s):

Hot Spots ◽

Test Procedure ◽

Great Influence ◽

Wear Behaviour ◽

Test Duration ◽

Short Period ◽

Brush Seals ◽

Time Required ◽

Total Test

Abstract Although some investigations on the wear behaviour of brush seals can be found in the literature, not all aspects are yet understood during the wear-in process of the seal in operation. However, it is important to understand all aspects in order to ensure a long service life of the seal. The present paper gives an overview of the procedure, the results and the knowledge gained through the long-term rub tests carried out with a tungsten carbide coated rotor with the aim of determining the time required to wear the seal in (“time-on-condition”). The total test duration of the cyclic tests was approx. 100 h. The measurements have shown that on the basis of the applied test procedure the initial wear-in phase is completed after approx. 40 cumulated operating hours and only very little wear occurs afterwards. Furthermore, it could be shown that the major part of the wear occurred within a short period of time within these 40 h and that the properties of the test cycle have a great influence on the wear-in time. The coupling of the rubbing intensity with time is achieved by measuring the transient rotor temperatures during rubbing. The tests carried out have also shown that the influence of the concentricity properties of the rotor can resulting in rotor temperature deviations over the circumference (“hot spots”).

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WoundClot® Hemostatic Gauze Reduces Bleeding Time after Arterial Venous Fistula Decannulation

Blood Purification ◽

10.1159/000514934 ◽

2021 ◽

pp. 1-7

Author(s):

Orit Kliuk-Ben Bassat ◽

Doron Schwartz ◽

Alexander Zubkov ◽

Amir Gal-Oz ◽

Alexander Gorevoy ◽

...

Keyword(s):

Bleeding Time ◽

Control Group ◽

Dialysis Adequacy ◽

Cotton Gauze ◽

Single Center Study ◽

Time Required ◽

Venous Fistula ◽

Thrombosis Rate

Introduction: Decannulation of the arteriovenous fistula (AVF) after each hemodialysis session requires a precise compression on the needle puncture site. The objective of our study was to evaluate the bleeding time (BT) needed to achieve hemostasis using WoundClot, an innovative hemostatic gauze, and to assess whether its long-term use can improve AVF preservation. Methods: This is a prospective single center study. Initially, the time to hemostasis after AVF decannulation was compared between WoundClot and cotton gauze in 24 prevalent hemodialysis patients. Thereafter, the patients continued to use WoundClot for 12 months and were compared to a control group consisting of 25 patients using regular cotton gauze. Follow-up data included parameters of dialysis adequacy, AVF interventions, and thrombotic events. Results: WoundClot use shortened significantly the time needed for hemostasis. Mean venous BT decreased by 3.99 (±4.6) min and mean arterial BT by 6.38 (±4.8) min when using WoundClot compared to cotton gauze (p < 0.001). At the end of the study, dialysis adequacy expressed by spKt/V was higher in the WoundClot group compared to control (1.73 vs. 1.53, respectively, p = 0.047). Although patients in WoundClot group had a higher baseline BT, arterial and venous pressures did not differ between the groups after a median follow up of 10.8 months. AVF thrombosis rate was similar between the groups. Conclusions: WoundClot hemostatic gauze significantly reduced the time required for hemostasis after AVF decannulation and may be associated with better AVF preservation. We suggest using WoundClot for arterial BT longer than 15 min and for venous BT longer than 12.5 min.

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Management of a Mycotic Aneurysm in a Patient with COVID-19: A Case Report

Medicina ◽

10.3390/medicina57060620 ◽

2021 ◽

Vol 57 (6) ◽

pp. 620

Author(s):

Muzammil H. Syed ◽

Mark Wheatcroft ◽

Danny Marcuzzi ◽

Hooman Hennessey ◽

Mohammad Qadura

Keyword(s):

Abdominal Aortic Aneurysm ◽

Aortic Aneurysm ◽

Stent Graft ◽

Mycotic Aneurysm ◽

Neurological Deficits ◽

Endovascular Stent ◽

Endovascular Stents ◽

Abdominal Aortic ◽

Short Period

The aim of this paper is to share our experience in managing a patient with Klebsiella pneumoniae mycotic abdominal aortic aneurysm who was also infected with COVID-19. A 69-year-old male was transferred to our hospital for the management of an infra-renal mycotic abdominal aortic aneurysm. During his hospital course, the patient contracted severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). He was intubated due to respiratory distress. Over a short period, his mycotic aneurysm increased in size from 2.5 cm to 3.9 cm. An emergency repair of his expanding aneurysm was achieved using our previously described protocol of coating endovascular stents with rifampin. The patient was managed with a rifampin-coated endovascular stent graft without any major complications. Postoperatively, the patient did not demonstrate any neurological deficits nor any vascular compromise. He remained afebrile during his postoperative course and was extubated sometime thereafter. He was then transferred to the ward for additional monitoring prior to his discharge to a rehab hospital while being on long-term antibiotics. During his hospital stay, he was monitored with serial ultrasounds to ensure the absence of abscess formation, aortic aneurysm growth or graft endoleak. At 6 weeks after stent graft placement, he underwent a CT scan, which showed a patent stent graft, with a residual sac size of 2.5 cm without any evidence of abscess or endoleak. Over a follow-up period of 180 days, the patient remained asymptomatic while remaining on long-term antibiotics. Thus, in patients whose surgical risk is prohibitive, endovascular stent grafts can be used as a bridge to definitive surgical management.

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An unusually low density ultra-short period super-Earth and three mini-Neptunes around the old star TOI-561

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa3728 ◽

2020 ◽

Author(s):

G Lacedelli ◽

L Malavolta ◽

L Borsato ◽

G Piotto ◽

D Nardiello ◽

...

Keyword(s):

Transit Time ◽

Time Variation ◽

Planetary System ◽

Radial Velocities ◽

Low Density ◽

Outer Planets ◽

Short Period ◽

The Stability

Abstract Based on HARPS-N radial velocities (RVs) and TESS photometry, we present a full characterisation of the planetary system orbiting the late G dwarf After the identification of three transiting candidates by TESS, we discovered two additional external planets from RV analysis. RVs cannot confirm the outer TESS transiting candidate, which would also make the system dynamically unstable. We demonstrate that the two transits initially associated with this candidate are instead due to single transits of the two planets discovered using RVs. The four planets orbiting TOI-561 include an ultra-short period (USP) super-Earth (TOI-561 b) with period Pb = 0.45 d, mass Mb = 1.59 ± 0.36 M⊕ and radius Rb = 1.42 ± 0.07 R⊕, and three mini-Neptunes: TOI-561 c, with Pc = 10.78 d, Mc = 5.40 ± 0.98 M⊕, Rc = 2.88 ± 0.09 R⊕; TOI-561 d, with Pd = 25.6 d, Md = 11.9 ± 1.3 M⊕, Rd = 2.53 ± 0.13 R⊕; and TOI-561 e, with Pe = 77.2 d, Me = 16.0 ± 2.3 M⊕, Re = 2.67 ± 0.11 R⊕. Having a density of 3.0 ± 0.8 g cm−3, TOI-561 b is the lowest density USP planet known to date. Our N-body simulations confirm the stability of the system and predict a strong, anti-correlated, long-term transit time variation signal between planets d and e. The unusual density of the inner super-Earth and the dynamical interactions between the outer planets make TOI-561 an interesting follow-up target.

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Heatwaves in Kenya 1987–2016: Facts from CHIRTS High Resolution Satellite Remotely Sensed and Station Blended Temperature Dataset

Atmosphere ◽

10.3390/atmos12010037 ◽

2020 ◽

Vol 12 (1) ◽

pp. 37

Author(s):

Martial Amou ◽

Amatus Gyilbag ◽

Tsedale Demelash ◽

Yinlong Xu

Keyword(s):

High Resolution ◽

Adaptation Strategies ◽

Reference Period ◽

The West ◽

Tana River ◽

Short Period ◽

The World ◽

Northern Side ◽

Data Source

As global temperatures continue to rise unabated, episodes of heat-related catastrophes across the world have intensified. In Kenya, heatwave phenomena and their associated impacts are ignored and neglected due to several reasons, including unreliable and inconsistent weather datasets and heatwave detection metrics. Based on CHIRTS satellite infrared estimates and station blended temperature, this study investigated the spatiotemporal distribution of the heatwave events over Kenya during 1987–2016 using the Heatwave Magnitude Index daily (HWMId). The results showed that contrary to the absence of heatwave records in official national and international disaster database about Kenya, the country experienced heatwaves ranging from less severe (normal) to deadly (super-extreme) between 1987 and 2016. The most affected areas were located in the eastern parts of the country, especially in Garissa and Tana River, and in the west-northern side around the upper side of Turkana county. It was also found that the recent years’ heatwaves were more severe in magnitude, duration, and spatial extent. The highest magnitude of the heatwaves was recorded in 2015 (HWMId = 22.64) while the average over the reference period is around 6. CHIRTS and HWMId were able to reveal and capture most critical heatwave events over the study period. Therefore, they could be used respectively as data source and detection metrics, for heatwaves disaster emergency warning over short period as well as for long-term projection to provide insight for adaptation strategies.

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Microscale Heterogeneous Distribution and Speciation of Phosphorus in Soils Amended with Mineral Fertilizer and Cattle Manure Compost

Minerals ◽

10.3390/min11020121 ◽

2021 ◽

Vol 11 (2) ◽

pp. 121

Author(s):

Noriko Yamaguchi ◽

Toshiaki Ohkura ◽

Atsuko Hikono ◽

Yohey Hashimoto ◽

Aomi Suda ◽

...

Keyword(s):

Hot Spots ◽

Mineral Fertilizer ◽

Chemical Extraction ◽

Heterogeneous Distribution ◽

Edge Structure ◽

Soil P ◽

Macro Scale ◽

Cattle Manure Compost ◽

High Degree

Global concerns for the sustainability of agriculture have emphasized the need to reduce the use of mineral fertilizer. Although phosphorus (P) is accumulated in farmland soils due to the long-term application of fertilizer, most soil P is not readily available to plants. The chemical speciation of P in soils, which comprise heterogeneous microenvironments, cannot be evaluated with a high degree of specificity using only macroscopic analyses. In this study, we investigated the distribution and speciation of P accumulated in soils by using both macro- and microscopic techniques including chemical extraction, solution and solid-state 31P NMR, bulk- and micro- P K-edge X-ray absorption near edge structure (XANES), and electron probe microanalysis (EPMA). Soil samples were collected from a field in which cabbage was cultivated under three amendment treatments: i) mineral fertilizer (NPK), ii) mineral fertilizer and compost (NPK + compost), and iii) mineral fertilizer plus compost but without nitrogen fertilizer (PK + compost). Macro-scale analyses suggested that accumulated P was predominantly inorganic P and associated with Al-bearing minerals. The repeated application of compost to the soils increased the proportion of P associated with Ca which accounted for 17% in the NPK + compost plot and 40% in the PK + compost plot. At the microscale, hot spots of P were heterogeneously distributed, and P was associated with Fe and Ca in hot spots of the NPK + compost (pH 6) and PK + compost (pH 7) treated samples, respectively. Our results indicate that application of compost contributed to creating diverse microenvironments hosting P in these soils.

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Long-term efficacy of a short period of taping followed by an exercise program in a cohort of patients with patellofemoral pain syndrome

Clinical Rheumatology ◽

10.1007/s10067-011-1883-2 ◽

2011 ◽

Vol 31 (3) ◽

pp. 535-539 ◽

Cited By ~ 13

Author(s):

Marco Paoloni ◽

Giancarlo Fratocchi ◽

Massimiliano Mangone ◽

Massimiliano Murgia ◽

Valter Santilli ◽

...

Keyword(s):

Exercise Program ◽

Pain Syndrome ◽

Patellofemoral Pain Syndrome ◽

Patellofemoral Pain ◽

Term Efficacy ◽

Short Period

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Rumen Fermentation Characteristics Require More Time to Stabilize When Diet Shifts

Animals ◽

10.3390/ani11082192 ◽

2021 ◽

Vol 11 (8) ◽

pp. 2192

Author(s):

Qinghua Qiu ◽

Chaoyu Gao ◽

Huawei Su ◽

Binghai Cao

Keyword(s):

Repeated Measures ◽

Mixed Model ◽

Proper Time ◽

Rumen Fermentation ◽

Metabolizable Energy ◽

Stabilization Time ◽

Time Required ◽

Dietary Treatments ◽

Diet Shifts

This study was conducted to explore the proper time required to achieve stabilization in digestibility, serum metabolism, and rumen fermentation characteristics when different diets shift, thus providing decision-making of practical sampling frequency for basal nutritional research. For these purposes, 12 Holstein steers (body weight 467 ± 34 kg, age 14 ± 0.5 months) were equally assigned to two dietary treatments: high-density (metabolizable energy (ME) = 2.53 Mcal/kg and crude protein (CP) = 119 g/kg; both ME and CP were expressed on a dry matter basis) or low-density (ME = 2.35 Mcal/kg and CP = 105 g/kg). The samples of feces, serum, and rumen contents were collected with a 30-day interval. All data involved in this study were analyzed using the repeated measures in mixed model of SPSS. Results showed that nutrient apparent digestibility and serum metabolic parameters were stable across each monthly collection, while most rumen fermentation characteristics, namely concentrations of acetate, propionate, isobutyrate, and valerate, were affected by the interaction effects between collection period and dietary density. These findings indicate that rumen fermentation characteristics require more time to stabilize when diet shifts. It is recommended to collect ruminal digesta monthly to evaluate rumen fermentation characteristics, while unnecessary to sample monthly for digestion trials and blood tests in the long-term fattening of Holstein steers. This study may provide insights into exploring the associations between detected parameters and stabilization time, and between diet type and stabilization time when diet shifts.

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Capturing Spatial and Temporal Patterns of NO2 in Cities using mobile and stationary DOAS measurements

10.5194/dach2022-153 ◽

2021 ◽

Author(s):

Mark Wenig ◽

Sheng Ye ◽

Ying Zhu ◽

Hanlin Zhang

Keyword(s):

Air Quality ◽

Hot Spots ◽

Temporal Patterns ◽

Optical Absorption Spectroscopy ◽

Spatial And Temporal Patterns ◽

The Public ◽

Measurement Height ◽

Weekly Cycles

The problem of elevated NO2 levels in cities has gained some attention in the public in recent years and has given rise to questions about the plausibility of banning diesel engines in cities, the meaning of exceedances of air quality limits and the effects of corona lock-downs on air quality to name a few. Urban air quality is typically monitored using a relatively small number of monitoring stations. Those in-situ measurements follow certain guidelines in terms of inlet height and location relative to streets, but the question remains how a limited number of point measurements can capture the spatial variability in cities. In this talk we present two measurement campaigns in Hong Kong and Munich where we utilized a combination of mobile in-situ and stationary remote sensing differential optical absorption spectroscopy (DOAS) instruments. We developed an algorithm to separate spatial and temporal patterns in order to generate pollution maps that represent average NO2 exposure.&#160; We use those maps to identify pollution hot spots and capture the weekly cycles of on-road NO2 levels and spatial dependency of long-term changes and we analyze how on-road measurements compare to monitoring station data and how the measurement height and distance to traffic emissions have to be considered when interpreting observed concentration patterns.

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Long-term development of short-period gravity waves in middle Europe

Journal of Geophysical Research Atmospheres ◽

10.1029/2010jd015544 ◽

2011 ◽

Vol 116 ◽

Cited By ~ 13

Author(s):

D. Offermann ◽

J. Wintel ◽

C. Kalicinsky ◽

P. Knieling ◽

R. Koppmann ◽

...

Keyword(s):

Gravity Waves ◽

Short Period ◽

Middle Europe

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TRENDS IN DATA WAREHOUSING TECHNIQUES

10.31219/osf.io/6cyq4 ◽

2021 ◽

Author(s):

Naveen Kunnathuvalappil Hariharan

Keyword(s):

Relational Databases ◽

Financial Data ◽

Relational Model ◽

Time Data ◽

Short Period ◽

The Subject ◽

Processing And Storage ◽

And Storage ◽

Long Term Trend

Financial data volumes are increasing, and this appears to be a long-term trend, implying that data managementdevelopment will be crucial over the next few decades. Because financial data is sometimes real-time data, itis constantly generated, resulting in a massive amount of financial data produced in a short period of time.The volume, diversity, and velocity of Big Financial Data are highlighting the significant limitations oftraditional Data Warehouses (DWs). Their rigid relational model, high scalability costs, and sometimesinefficient performance pave the way for new methods and technologies. The majority of the technologiesused in background processing and storage research were previously the subject of research in their earlystages. The Apache Foundation and Google are the two most important initiatives. For dealing with largefinancial data, three techniques outperform relational databases and traditional ETL processing: NoSQL andNewSQL storage, and MapReduce processing.

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