scholarly journals Assessment of the intensity of engine oil contamination during operation

2021 ◽  
Vol 2131 (3) ◽  
pp. 032061
Author(s):  
V Zhukov ◽  
O Melnik ◽  
E Khmelevskaya
Keyword(s):  
Internal Combustion Engines ◽  
Operating Time ◽  
Operating Conditions ◽  
Engine Oil ◽  
Oil Contamination ◽  
Engine Oils ◽  
Average Operating ◽  
Average Operating Time ◽  
Dispersing Ability ◽  
Physical And Chemical

Abstract The acceleration of internal combustion engines leads to an increase in thermal and mechanical loads on the most critical parts. To ensure the required resource indicators in conditions of increased loads, it is necessary to use high-quality lubricants, the requirements for the operational properties of which are also steadily increasing. In order to ensure the necessary physical and chemical characteristics of engine oils, additives are introduced into their composition, but during operation the quality of engine oil decreases, the reasons for this are both the destruction of additives, and the accumulation of dirt particles in the oil and the ingress of fuel and coolant into the oil. The conducted studies are devoted to determining the intensity of engine oil contamination under operating conditions in the Wärtsilä 6L20 engine lubrication system and the effectiveness of the dispersing additives contained in the oil. Samples of Petro Canada and TARO oils brands were used as prototypes at the beginning of the operational period, at the time of average operating time and at the time of oil change. The dispersing ability of the oil was determined by the method of assessing the oil stain. According to the results of the research, it is concluded that when the properties of the oil change as a result of contamination, their dispersing ability remains satisfactory. This result can serve as a justification for extending the service life of engine oil, provided that its properties are monitored during operation.

scholarly journals USAGE OF HIGH-QUALITY ENGINE OILS WITH EXTENDED REPLACEMENT INTERVALS: FEATURES OF THE EQUIPMENT OPERATION

2019 ◽  
Vol 16 (4) ◽  
pp. 446-454
Author(s):  
N. Y. Machekhin ◽  
I. I. Shirlin ◽  
S. V. Pashukevich
Keyword(s):  
Internal Combustion Engines ◽  
Economic Effect ◽  
Operating Time ◽  
The State ◽  
Engine Oil ◽  
Base Number ◽  
High Quality ◽  
Engine Oils ◽  
Equipment Operation ◽  
Motor Oils

Introduction. The effective operation of cars largely depends on the state of the engines, their downtime in maintenance and repair. Since the maintenance of modern engines is often reduced to the replacement of engine oil, the increase in the duration of its work significantly reduces maintenance costs and downtime in maintenance. Long maintenance-free operation of the internal combustion engines of automotive vehicles is directly related to the state of the engine oil used in this power unit. The aim of the paper is to show the features of the equipment operation with significant intervals of the engine oils’ replacement in order to increase the efficiency of its usage. The paper presents data on the features of the equipment operation when using high-quality motor oils with extended replacement intervals.Materials and methods. The authors conducted performance tests on the basis of MercedesBenzAxor, MercedesBenzActros cars. The manufacturer provided an estimate of the performance of engine oils. The main performance characteristics of motor oils were assessed using standard methods: kinematic viscosity was measured using a Stabinger viscosimeter, the base number was determined by an automatic AT-500 titrator, the content of wear products was obtained using an ASP-coupled emission spectrophotometer.Results. As a result, the authors presented data on the dependence of the changes in the main indicators of engine oil performance while the operating time and also substantiated the requirements for the volumes of fresh engine oil to compensate losses.Discussion and conclusions. The intermediate control allows detecting faults in the internal car engines, as well as providing the most accurate prediction of the resource of the lubricant under consideration. Therefore, the increasing of the engine oil change interval allows getting a significant economic effect.

Minilaparotomy Cholecystectomy as a Day Surgery Procedure: A Prospective Clinical Pilot Study

2007 ◽  
Vol 96 (3) ◽  
pp. 206-208 ◽  
Author(s):  
J. Harju ◽  
M. Pääkkönen ◽  
M. Eskelinen
Keyword(s):  
Randomised Trial ◽  
Operating Time ◽  
Day Surgery ◽  
Prospective Randomised Trial ◽  
Wound Pain ◽  
Average Operating ◽  
Average Operating Time ◽  
Study Support ◽  
The Mean

Background and Aims: In some studies minilaparotomy cholecystectomy (MC) has been shown to be as good as laparoscopic cholecystectomy (LC) in the surgical treatment of cholecystolithiasis. To our knowledge, the MC operation is rarely considered as a day surgery procedure. Patients and Methods: Thirty elective symptomatic non-complicated patients were included in the study during the end of the year 2004 to June 2005. The mean age of patients was 52 years (range 27–68), the mean body mass index 29 kg/m2 (range 19–41). Gallstones were confirmed with ultrasound and the pre-operative liver laboratory tests were normal in all patients. A five (+/-2) centimetre-long incision was used avoiding to split the rectus abdominis muscle. All patients were re-evaluated four weeks postoperatively with the follow-up letter. Results: The average operating time was 51 minutes (range 30–105 minutes). Day surgery was possible in 25 cases (83%). Five patients (17%) stayed over night at the hospital. There were four (13%) conversions to conventional cholecystectomy. The average postoperative sick leave was 16 days (range 14–30). Two patients returned to hospital. One patient had wound pain, but no complication was found, and the patient was not admitted. One patient had a wound infection and spent 6 days in the hospital. Twenty-nine (97%) patients were satisfied with the operation and were ready to recommend it for other patients. Conclusions: The results of this study support the suitability of MC as a day surgery procedure, but a prospective randomised trial is needed to evaluate the relative advantages of MC and LC.

scholarly journals Video assisted resections. Increasing access to minimally invasive liver surgery?

2015 ◽  
Vol 42 (5) ◽  
pp. 318-324 ◽  
Author(s):  
Fabricio Ferreira Coelho ◽  
Marcos Vinícius Perini ◽  
Jaime Arthur Pirola Kruger ◽  
Renato Micelli Lupinacci ◽  
Fábio Ferrari Makdissi ◽  
...  
Keyword(s):  
Operating Time ◽  
Perioperative Outcomes ◽  
Liver Lesions ◽  
Minimally Invasive Liver Surgery ◽  
Video Assisted ◽  
Average Operating ◽  
Average Operating Time ◽  
Average Size ◽  
Anesthesia Time ◽  
Prospective Database

Objective: To evaluate perioperative outcomes, safety and feasibility of video-assisted resection for primary and secondary liver lesions. Methods : From a prospective database, we analyzed the perioperative results (up to 90 days) of 25 consecutive patients undergoing video-assisted resections in the period between June 2007 and June 2013. Results : The mean age was 53.4 years (23-73) and 16 (64%) patients were female. Of the total, 84% were suffering from malignant diseases. We performed 33 resections (1 to 4 nodules per patient). The procedures performed were non-anatomical resections (n = 26), segmentectomy (n = 1), 2/3 bisegmentectomy (n = 1), 6/7 bisegmentectomy (n = 1), left hepatectomy (n = 2) and right hepatectomy (n = 2). The procedures contemplated postero-superior segments in 66.7%, requiring multiple or larger resections. The average operating time was 226 minutes (80-420), and anesthesia time, 360 minutes (200-630). The average size of resected nodes was 3.2 cm (0.8 to 10) and the surgical margins were free in all the analyzed specimens. Eight percent of patients needed blood transfusion and no case was converted to open surgery. The length of stay was 6.5 days (3-16). Postoperative complications occurred in 20% of patients, with no perioperative mortality. Conclusion : The video-assisted liver resection is feasible and safe and should be part of the liver surgeon armamentarium for resection of primary and secondary liver lesions.

scholarly journals Micro-Pitting and Wear Assessment of PAO vs Mineral-Based Engine Oil Operating under Mixed Lubrication Conditions: Effects of Lambda, Roughness Lay and Sliding Direction

Lubricants ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 42 ◽  
Author(s):  
Aleks Vrček ◽  
Tobias Hultqvist ◽  
Yannick Baubet ◽  
Marcus Björling ◽  
Pär Marklund ◽  
...  
Keyword(s):  
Bearing Steel ◽  
Mixed Lubrication ◽  
Operating Conditions ◽  
Engine Oil ◽  
Engine Oils ◽  
Rolling Contacts ◽  
Steel Surfaces ◽  
Wear Damage ◽  
Lubrication Conditions ◽  
Ball On Disc

Under certain operating conditions, rolling contacts have been shown to experience some challenges when lubricated with engine oils containing zinc dialkyldithophosphate (ZDDP) anti-wear additive. In order to better understand the main damage mechanisms during various operating conditions, further studies are needed. This article studies micro-pitting and wear damages of bearing steel surfaces under mixed lubrication conditions in a ball-on-disc setup, lubricated with different engine oils. Based on the results, micro-pitting and wear damage is shown to be highly case-dependent. In general, PAO-based engine oil tends to eliminate micro-pitting damage compared to mineral-based engine oil at less severe lubricating conditions. Moreover, a critical lambda was found for both oils, where the highest micro-pitting damage was observed.

Laparoscopic “en-bloc” ligation of spermatic veins

1996 ◽  
Vol 63 (3) ◽  
pp. 384-388
Author(s):  
C. Trombetta ◽  
G. Savoca ◽  
G. Liguori ◽  
A. Tamai ◽  
S. Siracusano ◽  
...  
Keyword(s):  
General Anaesthesia ◽  
Operating Time ◽  
Case Histories ◽  
En Bloc ◽  
Optical Magnification ◽  
Average Operating ◽  
Average Operating Time ◽  
The Right

Laparoscopic varicocelectomy is suggested only for II-III grade bilateral varicocele. The optical magnification granted by videosurgical techniques, prevents damaging testicular arteries; this possibility, however, requires a considerable amount of time. We performed a laparoscopic “en-bloc” ligation without sparing the artery on 13 patients with bilateral varicocele in order to assess eventual changes in gonadal volume. 10 patients underwent bilateral “en-bloc” ligation of spermatic vessels with an average operating time of 21 minutes. In 3 other patients, “en-bloc” ligation was performed on the right side while on the left side the artery was identified and saved; in these cases the average operating time was 33 minutes. After an average follow-up period of 19 months no cases of testicle atrophy nor of hydrocele were reported. ColorDoppler sonography, performed 3 months later on the 10 patients treated by bilateral “en-bloc” ligation, showed no persistent reflux. No case of homolateral persistent reflux was encountered in the 3 patients who underwent only right-side “en-bloc” ligation, but on the left side, where selective ligation had been performed, persistence of reflux was registered in one patient. Our experience has confirmed that laparoscopic “en-bloc” ligation of the internal spermatic pedicle, sparing vasa deferentia, prevents the persistence of reflux in all cases and allows a reduction in operating time. The opportunity of treating a pathology like bilateral varicocele by means of laparoscopy, which requires general anaesthesia, needs further confirmation and a larger number of case histories.

scholarly journals Laparoscopic Adrenalectomy for Adrenal Tumors

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Sun Chuan-yu ◽  
Ho Yat-faat ◽  
Ding Wei-hong ◽  
Gou Yuan-cheng ◽  
Hu Qing-feng ◽  
...  
Keyword(s):  
Blood Loss ◽  
Laparoscopic Adrenalectomy ◽  
Benign Tumor ◽  
Operating Time ◽  
Adrenal Tumors ◽  
Benign Tumors ◽  
Intraoperative Blood Loss ◽  
First Choice ◽  
Average Operating ◽  
Average Operating Time

Objective. To evaluate the indication and the clinical value of laparoscopic adrenalectomy of different types of adrenal tumor.Methods. From 2009 to 2014, a total of 110 patients were diagnosed with adrenal benign tumor by CT scan and we performed laparoscopic adrenalectomy. The laparoscopic approach has been the procedure of choice for surgery of benign adrenal tumors, and the upper limit of tumor size was thought to be 6 cm.Results. 109 of 110 cases were successful; only one was converted to open surgery due to bleeding. The average operating time and intraoperative blood loss of pheochromocytoma were significantly more than the benign tumors (P<0.05). After 3 months of follow-up, the preoperative symptoms were relieved and there was no recurrence.Conclusions. Laparoscopic adrenalectomy has the advantages of minimal invasion, less blood loss, fewer complications, quicker recovery, and shorter hospital stay. The full preparation before operation can decrease the average operating time and intraoperative blood loss of pheochromocytomas. Laparoscopic adrenalectomy should be considered as the first choice treatment for the resection of adrenal benign tumor.

scholarly journals Determination of engine oil change interval for patrol engines based on actual operating time

2021 ◽  
Vol 18 (3) ◽  
pp. 274-285
Author(s):  
A. A. Abakarov ◽  
Sh. M. Igitov ◽  
Ali A. Abakarov
Keyword(s):  
Operating Time ◽  
Chemical Properties ◽  
The United States ◽  
Climatic Conditions ◽  
Operating Conditions ◽  
Engine Oil ◽  
Rolling Stock ◽  
Passenger Cars ◽  
Gasoline Engines ◽  
On The Road

Introduction. This paper shows the results of a study of the frequency of maintenance of passenger cars in various operating conditions, and provides recommendations for replacing the engine oil of gasoline engines (category SN classification according to API) according to the actual engine operating time (moto-hours). The service book of passenger cars contains the regulations for car maintenance with a list of operations that must be performed. The oil change intervals specified in the Regulations on Maintenance and Repair of Rolling Stock of motor Transport and the factory instructions do not take into account the specifics of the operation of vehicles. Depending on the road and climatic conditions and the operating mode, the standard maintenance schedule can be adjusted, in particular, the frequency of engine oil changes. The scientific novelty of the work is to determine the intervals of car maintenance for specific operating conditions.Materials and methods. The paper presents an analysis of Russian and foreign car maintenance systems, in particular, the oil change intervals of gasoline engines in European countries, the United States and Japan.The results of operational and resource tests of motor oils of gasoline engines carried out by methods of measuring their physical and chemical properties are presented.Results. In this paper, based on the analysis of the problem, recommendations for changing oil in gasoline engines by motorcycle hours for the conditions of the Republic of Dagestan (RD) are developed.The use of external and built-in technical means for calculating the motor hours allows you to determine the recommended oil change interval.Discussion and conclusion. In this paper, on the basis of research on a certain number of vehicles operating in various (including difficult) conditions, recommendations are developed that allow you to determine the rules of car maintenance for various operating conditions.

scholarly journals Modeling working processes of self-regenerating filters functioning in lubricating systems of ship diesels

2020 ◽  
Vol 2020 (2) ◽  
pp. 69-80
Author(s):  
Gennadiy Petrovich Kicha ◽  
Sergey Petrovich Boyko ◽  
Paul Petrovich Kicha
Keyword(s):  
Internal Combustion Engines ◽  
Filter Design ◽  
Operating Conditions ◽  
The Self ◽  
Coarse Grained ◽  
Engine Oil ◽  
Fuel Quality ◽  
Hydrodynamic Modes ◽  
Self Cleaning ◽  
Working Processes

The article highlights the urgency of the research of working processes of a self-cleaning filter designed to purify the engine oil in the internal combustion engines. There was carried out experimental modeling of countercurrent regeneration of self-cleaning filters used in fuel preparation and diesel lubrication systems on ships. The layout of the unit for modeling the working processes of self-regenerating filters includes a service tank, a hydraulic motor with a stirrer, a pump, a hydraulic cylinder, a receiver of compressed air, a waste tank, a filtering element, shut-off and pneumatic control equipment, a pollution gauge, a temperature sensor, and other elements. A planning matrix is formed, and the experiment results on evaluating the efficiency of the self-regenerating filters are illustrated. The main factors of the regeneration coefficient are considered. There are presented the dependencies of evaluating the process effectiveness and predicting the life of filters between dry cleanings. The methods of calculating the regeneration parameters of automated filters based on the SRF-60 and SRFD-120 modules have been presented, which allows choosing the hydrodynamic modes and backwash time of filter elements taking into account the operating conditions of oil filters. The influence of the filtering process regeneration efficiency identified by the specific intensity of the removal of the dispersed phase from the oil, hydrodynamics (Reynolds number) and the relative backwash time, the adhesive properties of sludge, the filter design, and dispersion of the pollution are analyzed. The evidence of the validation of the calculated experimental dependences obtained from the laboratory tests of the filter model and their compliance with the results of field tests of self-cleaning filters on ships are presented. The possibility of calculating and adjusting the off-line operation of the self-cleaning filter in the lubrication systems of marine diesel engines is presented subject to diesel forcing, fuel quality and lubricants used, oil aging, additives wear and contamination by coarse-grained mechanical impurities.

scholarly journals URBAN PUBLIC TRANSPORT: MARGINAL VALUE OF THE CAPACITY FACTOR

2019 ◽  
Vol 16 (3) ◽  
pp. 290-301
Author(s):  
A. I. Fadeev ◽  
Ye. V. Fomin ◽  
S. Alhusseini
Keyword(s):  
Public Transport ◽  
Operating Time ◽  
Capacity Utilization ◽  
Utilization Factor ◽  
Marginal Value ◽  
Passenger Traffic ◽  
Urban Public Transport ◽  
Speed Fluctuation ◽  
Average Operating ◽  
Average Operating Time

Introduction. One of the most important indicators determining the public transport service quality is the capacity utilization factor of transport fleet. This parameter directly effects on the economic efficiency of the transport organization. For the carrier it is desirable from an economic point of view that the value of the capacity utilization factor takes on the greatest value. Passengers, on the contrary, prefer to transfer without overfull capacity of transport vehicles. Moreover, this factor is used in determining travel fares, analyzing the executed movement regarding the availability of reserves in carrying capacity and planning transportation process. The paper discusses the method of marginal value calculation of the transport fleet’s capacity utilization factor of urban public transport based on ensuring standard vehicle's cabin filling limits.Materials and methods. The authors solved the task of determining the filling marginal value for transport fleet while working on regular urban routes by analyzing the dependence of the capacity utilization factor on the passenger traffic parameters, the average operating time of the transport fleet on the route and the speed fluctuation during public transport operation. The authors also proposed the indicator of the transportation speed fluctuation during the operation of urban public transport.Results. The authors found out that the capacity utilization factor of transport fleet substantially depended on the passenger traffic parameters, on the average operating time of the transport fleet and on the speed fluctuation during public transport operation.Discussion and conclusion. The obtained dependences allow us calculating the marginal values of capacity utilization factor with taking into account the parameters of the planned transport process. The standard capacity utilization factor varies within considerable limits from 0.2 to 0.4, depending on the operating conditions.

833 Hyper Acute Dialysis Access Pathway (HADAP) – Undertaking Creation of Arteriovenous Fistulae in The Renal Ward

2021 ◽  
Vol 108 (Supplement_2) ◽  
Author(s):  
S Shetty ◽  
P Chowdary ◽  
D Dabare ◽  
C Seet ◽  
R Ahmed ◽  
...  
Keyword(s):  
Operating Time ◽  
Surgical Site Infections ◽  
Primary Patency ◽  
Successful Implementation ◽  
Dialysis Access ◽  
Arteriovenous Fistulae ◽  
Surgical Assistance ◽  
Average Operating ◽  
Average Operating Time ◽  
Duration Of Operation

Abstract Introduction The impetus to apply the “lean method” to creation of arteriovenous fistulae came with the pandemic restricting access to theatres. Here we present HADAP implemented in a dedicated procedure room in the Renal ward. Method Between April and September 2020, 44 patients underwent ward-based arteriovenous fistula operations with no more than 3 people in the room – surgeon, runner and patient. The parameters assessed were duration of operation, complications, patency, patient and surgeon feedback and financial implications. Results The service was predominantly registrar-led who created 91% of the fistulae. 95% operations were completed successfully with a 2-week primary patency of 73% and no surgical site infections. 40% of the procedures were radiocephalic fistulae. 14% procedures required surgical assistance by the runner. The average operating time reduced from 90 minutes for the first 10 cases to 50 minutes for the last 9. A structured questionnaire showed positive feedback from both patients and surgeons (4-5 out of 5). This service has cleared potentially 9 main theatre lists for more complex procedures. Conclusions Our study demonstrates the successful implementation of a novel operating environment allowing expedited care for renal failure patients. It has enhanced our ability to deliver a dialysis access program despite the challenges of COVID.

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