The effect of irrigation time and type of irrigation fluid on cartilage surface friction

2018 ◽  
Vol 77 ◽  
pp. 187-191 ◽  
Author(s):  
F. Stärke ◽  
F. Awiszus ◽  
C.H. Lohmann ◽  
C. Stärke
Keyword(s):  
Surface Friction ◽  
Cartilage Surface ◽  
Irrigation Fluid ◽  
Irrigation Time

scholarly journals Arthroscopic irrigation of the bovine stifle joint increases cartilage surface friction and decreases superficial zone lubricin

2016 ◽  
Vol 49 (13) ◽  
pp. 3106-3110 ◽  
Author(s):  
Erin Teeple ◽  
Naga Padmini Karamchedu ◽  
Katherine M. Larson ◽  
Ling Zhang ◽  
Gary J. Badger ◽  
...  
Keyword(s):  
Surface Friction ◽  
Superficial Zone ◽  
Cartilage Surface ◽  
Stifle Joint

DETERMINATION OF PERFORMANCE INDICATORS OF THE TRUCK KrAZ-6510TE

2020 ◽  
pp. 19-26
Author(s):  
Olexandr Pavlenko ◽  
Serhii Dun ◽  
Maksym Skliar
Keyword(s):  
Mathematical Model ◽  
Surface Friction ◽  
Building Structures ◽  
Maximum Torque ◽  
Military Equipment ◽  
Military Vehicles ◽  
Force Magnitude ◽  
Vehicle Mobility ◽  
The Mathematical Model

In any economy there is a need for the bulky goods transportation which cannot be divided into smaller parts. Such cargoes include building structures, elements of industrial equipment, tracked or wheeled construction and agricultural machinery, heavy armored military vehicles. In any case, tractor-semitrailer should provide fast delivery of goods with minimal fuel consumption. In order to guarantee the goods delivery, tractor-semitrailers must be able to overcome the existing roads broken grade and be capable to tow a semi-trailer in off-road conditions. These properties are especially important for military equipment transportation. The important factor that determines a tractor-semitrailer mobility is its gradeability. The purpose of this work is to improve a tractor-semitrailer mobility with tractor units manufactured at PJSC “AutoKrAZ” by increasing the tractor-semitrailer gradeability. The customer requirements for a new tractor are determined by the maximizing the grade to 18°. The analysis of the characteristics of modern tractor-semitrailers for heavy haulage has shown that the highest rate of this grade is 16.7°. The factors determining the limiting gradeability value were analyzed, based on the tractor-semitrailer with a KrAZ-6510TE tractor and a semi-trailer with a full weight of 80 t. It has been developed a mathematical model to investigate the tractor and semi-trailer axles vertical reactions distribution on the tractor-semitrailer friction performances. The mathematical model has allowed to calculate the gradeability value that the tractor-semitrailer can overcome in case of wheels and road surface friction value and the tractive force magnitude from the engine. The mathematical model adequacy was confirmed by comparing the calculations results with the data of factory tests. The analysis showed that on a dry road the KrAZ-6510TE tractor with a 80 t gross weight semitrailer is capable to climb a gradient of 14,35 ° with its coupling mass full use condition. The engine's maximum torque allows the tractor-semitrailer to overcome a gradient of 10.45° It has been determined the ways to improve the design of the KrAZ-6510TE tractor to increase its gradeability. Keywords: tractor, tractor-semitrailer vehicle mobility, tractor-semitrailer vehicle gradeability.

Tap Water As Irrigation Fluid in Percutaneous Nephrolithotomy

2012 ◽  
Vol 3 (4) ◽  
pp. 1-2
Author(s):  
* Dr. Prashant Hansraj Salvi ◽  
◽  
Dr.Ketan Vartak ◽  
Dr. Sudhir Shinde
Keyword(s):  
Percutaneous Nephrolithotomy ◽  
Tap Water ◽  
Irrigation Fluid

RELAÇÃO VAZÃO x PRESSÃO EM MICROASPERSORES DAN 2001 SOB CONDIÇÃO ADVERSA DE OPERAÇÃO

Irriga ◽  
2003 ◽  
Vol 8 (1) ◽  
pp. 63-68 ◽  
Author(s):  
Marco Antonio Fonseca Conceição ◽  
Rubens Duarte Coelho
Keyword(s):  
Hydraulic Performance ◽  
Sao Paulo ◽  
The Self ◽  
São Paulo ◽  
Flow Curves ◽  
Pressure Flow ◽  
Adverse Condition ◽  
Irrigation Time ◽  
E Mail ◽  
Stable Flow

RELAÇÃO VAZÃO x PRESSÃO EM MICROASPERSORES DAN 2001 SOB CONDIÇÃO ADVERSA DE OPERAÇÃO  Marco Antônio Fonseca ConceiçãoEmbrapa Uva e Vinho, Estação Experimental de Jales, Jales, SP. CP 241. CEP 15700-000.E-mail: [email protected] Duarte CoelhoDepartamento de Engenharia Rural, Escola Superior de Agricultura “Luiz de Queiroz”, Universidade de São Paulo, Piracicaba, SP. CP 09, CEP 13418-900.E-mail: [email protected]  1 RESUMO  Alguns microaspersores possuem membranas que regulam a sua pressão de operação, mantendo a vazão praticamente estável dentro de uma faixa de pressão na rede hidráulica. Operadores de irrigação no campo, muitas vezes com baixo nível de instrução e sem orientação profissional qualificada, visando reduzir problemas de entupimento ou para diminuir o tempo de irrigação, costumam retirar as membranas autocompensantes para aumentar a vazão do emissores, o que pode comprometer o desempenho hidráulico do sistema. Para avaliar o efeito da retirada da membrana  sobre as vazões dos microaspersores, no presente trabalho determinou-se as relações entre pressão e vazão para sete bocais do microaspersor DAN 2001, operando na ausência da membrana autocompensante. As curvas pressão-vazão sem as membranas autocompensantes apresentaram comportamento potencial com expoentes variando entre 0,58 e 0,64. As vazões dos microaspersores sem as membranas aumentaram de forma inversamente proporcional aos diâmetros dos emissores, quando comparadas às vazões nominais com as membranas.  UNITERMOS: Hidráulica, irrigação, microaspersão.  CONCEIÇÃO, M.A.F.; COELHO, R.D. FLOW X PRESSURE RELATIONSHIP FOR DAN 2001 MICROSPRINKLERS UNDER ADVERSE CONDITION  2 ABSTRACT  Many types of microsprinklers have a self-compensating membrane to regulate their pressure, keeping a stable flow. Many producers usually take the membranes off to reduce clogging problems  or irrigation time. This procedure could endanger the system hydraulic performance. To evaluate the effect of taking off the self-compensating membrane from microsprinklers it was determined, in the present work, the pressure-flow relationship for seven Dan 2001 microsprinkler nozzles operating without the membrane. The pressure-flow curves presented a potential behavior with the exponents varying from 0.58 to 0.64. Microsprinkler flows without the membranes increased inversely proportional to the emitter diameters, comparing to the nominal flows using the membranes.  KEYWORDS: Hydraulic, irrigation, microsprinkler.

scholarly journals Hyperchloremic metabolic acidosis during bipolar transurethral resection of the prostate: a report of two cases

2021 ◽  
Vol 49 (6) ◽  
pp. 030006052110244
Author(s):  
Ann Hee You ◽  
Ji Yoo Lee ◽  
Jeong-Hyun Choi ◽  
Mi Kyeong Kim
Keyword(s):  
Metabolic Acidosis ◽  
Transurethral Resection ◽  
Normal Saline ◽  
Isotonic Saline ◽  
Hemodynamic Instability ◽  
Acid Base ◽  
Electrolyte Disturbance ◽  
Irrigation Fluid ◽  
Laboratory Test Results ◽  
Hyperchloremic Metabolic Acidosis

Compared with monopolar transurethral resection of the prostate (TURP), which requires electrolyte-free irrigation fluid, normal saline can be used as the irrigation solution in bipolar and laser TURP. The risk of TURP syndrome and severe electrolyte disturbance is minimized when normal saline is used as the irrigation fluid. However, the use of isotonic saline also causes acid-base imbalance and electrolyte disturbance. We experienced two patients who developed hyperchloremic metabolic acidosis during bipolar TURP. After proper intervention, hemodynamic instability resolved, and laboratory test results normalized. Anesthesiologists must pay attention to acid-base and electrolyte status when rapid absorption of excessive isotonic solution is suspected, even during bipolar and laser TURP, which use normal saline as the irrigation fluid.

Overlapping Allografts Provide Superior and More Reliable Surface Topography Matching Than Oblong Allografts: A Computer-Simulated Model Study

2021 ◽  
pp. 036354652110030
Author(s):  
Hailey P. Huddleston ◽  
Atsushi Urita ◽  
William M. Cregar ◽  
Theodore M. Wolfson ◽  
Brian J. Cole ◽  
...  
Keyword(s):  
Articular Cartilage ◽  
Surface Topography ◽  
Osteochondral Allograft ◽  
Cartilage Defects ◽  
Radius Of Curvature ◽  
Cartilage Surface ◽  
3 Dimensional ◽  
Cloud Models ◽  
And Cartilage ◽  
Osteochondral Allografts

Background: Osteochondral allograft transplantation is 1 treatment option for focal articular cartilage defects of the knee. Large irregular defects, which can be treated using an oblong allograft or multiple overlapping allografts, increase the procedure’s technical complexity and may provide suboptimal cartilage and subchondral surface matching between donor grafts and recipient sites. Purpose: To quantify and compare cartilage and subchondral surface topography mismatch and cartilage step-off for oblong and overlapping allografts using a 3-dimensional simulation model. Study Design: Controlled laboratory study. Methods: Human cadaveric medial femoral hemicondyles (n = 12) underwent computed tomography and were segmented into cartilage and bone components using 3-dimensional reconstruction and modeling software. Segments were then exported into point-cloud models. Modeled defect sizes of 17 × 30 mm were created on each recipient hemicondyle. There were 2 types of donor allografts from each condyle utilized: overlapping and oblong. Grafts were virtually harvested and implanted to optimally align with the defect to provide minimal cartilage surface topography mismatch. Least mean squares distances were used to measure cartilage and subchondral surface topography mismatch and cartilage step-off. Results: Cartilage and subchondral topography mismatch for the overlapping allograft group was 0.27 ± 0.02 mm and 0.80 ± 0.19 mm, respectively. In comparison, the oblong allograft group had significantly increased cartilage (0.62 ± 0.43 mm; P < .001) and subchondral (1.49 ± 1.10 mm; P < .001) mismatch. Cartilage step-off was also found to be significantly increased in the oblong group compared with the overlapping group ( P < .001). In addition, overlapping allografts more reliably provided a significantly higher percentage of clinically acceptable (0.5- and 1-mm thresholds) cartilage surface topography matching (overlapping: 100% for both 0.5 and 1 mm; oblong: 90% for 1 mm and 56% for 0.5 mm; P < .001) and cartilage step-off (overlapping: 100% for both 0.5 and 1 mm; oblong: 86% for 1 mm and 12% for 0.5 mm; P < .001). Conclusion: This computer simulation study demonstrated improved topography matching and decreased cartilage step-off with overlapping osteochondral allografts compared with oblong osteochondral allografts when using grafts from donors that were not matched to the recipient condyle by size or radius of curvature. These findings suggest that overlapping allografts may be superior in treating large, irregular osteochondral defects involving the femoral condyles with regard to technique. Clinical Relevance: This study suggests that overlapping allografts may provide superior articular cartilage surface topography matching compared with oblong allografts and do so in a more reliable fashion. Surgeons may consider overlapping allografts over oblong allografts because of the increased ease of topography matching during placement.

scholarly journals Effects of irrigation fluid temperature during flexible ureteroscopic holmium laser lithotripsy on postoperative fever and shivering: a randomized controlled trial

BMC Urology ◽  
2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yue He ◽  
You-Gang Feng ◽  
Jun He ◽  
Bo Liang ◽  
Ming-Dong Jiang ◽  
...  
Keyword(s):  
Randomized Controlled Trial ◽  
Controlled Trial ◽  
Laser Lithotripsy ◽  
Holmium Laser ◽  
Fluid Temperature ◽  
Postoperative Fever ◽  
Irrigation Fluid ◽  
Suspected Infection ◽  
Randomized Controlled ◽  
Holmium Laser Lithotripsy

Abstract Background Flexible ureteroscopic holmium laser lithotripsy is used to treat urinary tract calculi, but postoperative complications include shivering, fever and infection. To investigate the effects of irrigation fluid temperature on postoperative complications. Methods This randomized controlled trial included 120 consecutive patients undergoing flexible ureteroscopic holmium laser lithotripsy at the Urology Department, Suining Central Hospital, Sichuan, China between January 2017 and July 2019. Patients were randomized 1:1:1 into three groups (17 °C, 27 °C or 37 °C). Primary outcome was fever incidence (body temperature > 37.5 °C) within 48 h after surgery. Secondary outcomes included shivering incidence during recovery from anesthesia, white blood cell count (WBC), serum procalcitonin (PCT) and incidence of suspected infection (temperature > 38.5 °C and PCT > 0.5 µg/L). Results There were 108 patients, (17 °C group, n = 36; 27 °C group, n = 35; 37 °C group, n = 37), received flexible ureteroscopic holmium laser lithotripsy and analyzed. Age, gender distribution, body mass index, ASA grade, stone burden, preoperative creatinine, preoperative core temperature and irrigation fluid volume did not differ significantly between groups. 17 °C, 27 °C and 37 °C groups exhibited significant differences in the incidences of postoperative fever (38.9% vs. 17.1% vs. 13.5%) and shivering (22.2% vs. 5.7% vs. 2.7%) (p < 0.05 for all pairwise comparisons). There was no significant difference of WBC, PCT and incidence of suspected infection in 37 °C or 27 °C group compared with 17 °C group. One case each of flash pulmonary edema and bleeding occurred in 37 °C group. Conclusion Warming the irrigation fluid can reduce the incidence of postoperative fever and shivering, but further studies are needed to determine the optimal temperature. Trial registration The trial was registered at the Chinese Clinical Trials Registry and allocated as ChiCTR2000031683. The trial was registered on 07/04/2020 and this was a retrospective registration.

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