Achievements in High Specific-Speed Water Turbines

1934 ◽  
Vol 128 (1) ◽  
pp. 361-407
Author(s):  
A. A. Fulton

The steady increase in the capacity of generating sets created a demand for the high specific-speed turbine which was met by several experimenters. “Specific speed” is the speed at which a turbine will run under unit head when developing unit power, and nowadays a “high specific-speed” water turbine denotes one having a runner of the propeller type and a specific speed between 100 and 230 r.p.m. Difficulties were encountered in the development of propeller turbines, especially in connexion with cavitation. Laboratory tests and the use of visual study methods have played an important part in the solution of these difficulties. The method of fixing suction head in conjunction with laboratory test results is explained, and a comparison is made between the various forms of suction tube in use. Much work has been done to overcome the effects of localized cavitation, and stainless steel has been found to be very effective, especially when runners are cast entirely of that material. A method of operation has been developed to dispense with the use of inlet sluice gates in large machines. Several methods in use for operating the movable runner blades are described. The introduction of the high specific-speed turbine has led to a large increase in the number of automatic stations. The great size attained by these turbines has entailed the construction of equally large generators, the development of which has had its own problems.

2020 ◽  
Author(s):  
Sabe Mwape ◽  
Victor Daka ◽  
Scott Matafwali ◽  
Kapambwe Mwape ◽  
Jay Sikalima ◽  
...  

Background Medical laboratory diagnosis is a critical component of patient management in the healthcare setup. Despite the availability of laboratory tests, clinicians may not utilise them to make clinical decisions. We investigated utilsation of laboratory tests for patient management among clinicians at Ndola Teaching Hospital (NTH) and Arthur Davison Childrens Hospital (ADCH), two large referral hospitals in the Copperbelt Province, Ndola, Zambia. Method We conducted a descriptive cross-sectional study among clinicians. The study deployed self-administered questionnaires to evaluate clinician utilisation, querying and confidence in laboratory results. Additional data on demographics and possible laboratory improvements were also obtained. Data were entered in Microsoft excel and exported to SPSS version 16 for statistical analysis. Results Of the 80 clinicians interviewed, 96.2% (77) reported using laboratory tests and their results in patient management. 77.5% (62) of the clinicians indicated they always used laboratory results to influence their patient management decisions. Of the selected laboratory tests, clinicians were more confident in using haemoglobin test results (91.2%). There was no statistically significant association between the clinicians gender or qualification and use of test results in patient management. Conclusion Our findings show that despite the majority querying laboratory results, most of the clinicians use laboratory results for patient management. There is need for interactions between the laboratory and clinical area to assure clinician confidence in laboratory results. Key words: utilisation, clinicians, laboratory tests, Ndola Teaching Hospital, Arthur Davison Childrens Hospital


1977 ◽  
Vol 99 (2) ◽  
pp. 264-271 ◽  
Author(s):  
J. F. Saltsman ◽  
G. R. Halford

As a demonstration of the predictive capabilities of the method of Strainrange Partitioning, published high-temperature, low cycle, creep-fatigue test results on AISI Types 304 and 316 stainless steel were analyzed and calculated cyclic lives compared with observed lives. Predicted lives agreed with observed lives within factors of two for 76 percent, factors of three for 93 percent, and factors of four for 98 percent of the laboratory tests analyzed. Agreement between observed and predicted lives is judged satisfactory considering that the data are associated with a number of variables (two alloys, several heats and heat treatments, a range of temperatures, different testing techniques, etc.) that are not directly accounted for in the calculations.


Author(s):  
H.-T. Liu ◽  
Y. Hovanski ◽  
M. E. Dahl

Laboratory tests were conducted to determine the fatigue performance of AWJ-machined aircraft titanium. Dog-bone specimens machined with AWJs were prepared and tested with and without sanding and dry-grit blasting with Al2O3 as secondary processes. The secondary processes were applied to remove the visual appearance of AWJ-generated striations and to clean up the garnet embedment. The fatigue performance of AWJ-machined specimens was compared with baseline specimens machined with CNC milling. Fatigue test results of the titanium specimens not only confirmed our previous findings in aluminum dog-bone specimens but in comparison also further enhanced the fatigue performance of the titanium. In addition, titanium is known to be difficult to cut, particularly for thick parts, however AWJs cut the material 34% faster than stainless steel. AWJ cutting and dry-grit blasting are shown to be a preferred combination for processing aircraft titanium that is fatigue critical.


2016 ◽  
Vol 32 (8) ◽  
pp. 500-507 ◽  
Author(s):  
Samih Raad ◽  
Rachel Elliott ◽  
Evan Dickerson ◽  
Babar Khan ◽  
Khalil Diab

Objective: In our academic intensive care unit (ICU), there is excess ordering of routine laboratory tests. This is partially due to a lack of transparency of laboratory-processing costs and to the admission order plans that favor daily laboratory test orders. We hypothesized that a program that involves physician and staff education and alters the current ICU order sets will lead to a sustained decrease in routine laboratory test ordering. Design: Prospective cohort study. Setting: Academic closed medical ICU (MICU). Patients: All patients admitted to the MICU. Methods: We consistently educated residents, faculty, and staff about laboratory test costs. We removed the daily laboratory test option from the admission order sets and asked residents to order needed laboratory test results every day. We only allowed the G3+I-STAT (arterial blood gas only) cartridges in the MICU in hopes of decreasing duplicative laboratory test results. We added laboratory review to the daily rounding checklist. Measurement and Main Results: Total number of laboratory tests per patient-day decreased from 39.43 to an average of 26.74 ( P <.001) over a 9-month period. The number of iSTAT laboratory tests per patient-day decreased from 7.37 to an average of 1.16 ( P < .001) over the same time period. The number of iSTAT/central laboratory processing duplicative laboratory tests per patient-day decreased from 0.17 to an average of 0.01 ( P < .001). The percentage of patients who have daily laboratory test orders decreased from 100% to an average of 11.94% ( P <. 001). US$123 436 in direct savings and US$258 035 dollars in indirect savings could be achieved with these trends. Intensive care unit morbidity and mortality were not impacted. Conclusion: A simple technique of resident, nursing, and ancillary staff education, combined with alterations in order sets using electronic medical records, can lead to a sustained reduction in laboratory test utilization over time and to significant cost savings without affecting patient safety.


2017 ◽  
Vol 25 (2) ◽  
pp. 121-126 ◽  
Author(s):  
Ronald George Hauser ◽  
Douglas B Quine ◽  
Alex Ryder

Abstract Objective Clinical laboratories in the United States do not have an explicit result standard to report the 7 billion laboratory tests results they produce each year. The absence of standardized test results creates inefficiencies and ambiguities for secondary data users. We developed and tested a tool to standardize the results of laboratory tests in a large, multicenter clinical data warehouse. Methods Laboratory records, each of which consisted of a laboratory result and a test identifier, from 27 diverse facilities were captured from 2000 through 2015. Each record underwent a standardization process to convert the original result into a format amenable to secondary data analysis. The standardization process included the correction of typos, normalization of categorical results, separation of inequalities from numbers, and conversion of numbers represented by words (eg, “million”) to numerals. Quality control included expert review. Results We obtained 1.266 × 109 laboratory records and standardized 1.252 × 109 records (98.9%). Of the unique unstandardized records (78.887 × 103), most appeared &lt;5 times (96%, eg, typos), did not have a test identifier (47%), or belonged to an esoteric test with &lt;100 results (2%). Overall, these 3 reasons accounted for nearly all unstandardized results (98%). Conclusion Current results suggest that the tool is both scalable and generalizable among diverse clinical laboratories. Based on observed trends, the tool will require ongoing maintenance to stay current with new tests and result formats. Future work to develop and implement an explicit standard for test results would reduce the need to retrospectively standardize test results.


2020 ◽  
Vol 19 (4) ◽  
pp. 031-042
Author(s):  
Grzegorz Sadowski ◽  
Piotr Wiliński ◽  
Anna Halicka

The paper presents a comparative analysis of the behaviour of a composite beam, consisted of a precast element with indented surface and new concrete layer, subjected to 4-point bending. The results obtained from the virtual model of the beam created using the finite element method (Abaqus/CEA 2019 software) were compared with the laboratory test results obtained with use of the digital image correlation (DIC) method for identifying the crack pattern. The virtual model of composite beam was calibrated by the choice of interface parameters ensuring that the value of load resulting in delamination between concrete layers was close to that value obtained in the laboratory tests. The comparative analysis showed that the pattern of bending and shear cracks and the pattern of interface crack obtained with the finite element method reflect the laboratory test results properly. It can be assumed that the crack between concrete layers is related to the appearance and propagation of shear cracks. On the basis of FEM analysis it can be concluded that the phenomena identified as “shear friction” and “dowel action” are significantly activated after the interface cracking.


2018 ◽  
Vol 2018 (2) ◽  
pp. 77-95
Author(s):  
Wojciech Zdrojewski

Abstract The article presents the result of tests of a single segment of a prototype water turbine, performed in order to determine its shaft power output as a function of rpm, and to verify the declared performance. The results have been compared with the outcomes of numerical calculations performed, for the same conditions, with the use of FLUENT software. The work presents information of crucial importance for presenting the process of testing the piece in question, such as: test environment, properties of the test piece, testing equipment used, as well as the methodology and the course of hydromechanical measurements, along with the characteristics of the results obtained. Then, the measurement results are discussed and analyzed. Conclusions are presented as well. Analysis of the results, taking into consideration the physical image of phenomena occurring in the case of flow-devices, such as water turbines, has made it possible to define other, important characteristics of the turbine, such as: output, shaft torque and efficiency, as a function of rpm and head of turbine. Test results have confirmed the expected mechanical and power-related properties of the turbine and have proved the numerical flow modeling model used effective. A brief description of the prospects concerning new applications of the turbine discussed has been presented as well


2020 ◽  
pp. 1-4
Author(s):  
Anders Larsson ◽  
Anders Larsson ◽  
Johan Ärnlöv ◽  
Johanna Helmersson-Karlqvist ◽  
Lars Lind ◽  
...  

Once considered a problem only for high-income countries, obesity rates are now rising worldwide. When evaluating test results from obese patients it is important to be aware of the effect of obesity on individual laboratory test results. The aim of the present study was to study the association between body mass index (BMI) and a group of frequently requested laboratory tests to evaluate which of these analytes that are affected by BMI. We analyzed the association between body mass index (BMI) and Alanine aminotransaminase (ALT), Albumin, Alkaline phosphatase, Pancreatic amylase, Apolipoprotein A1, Apolipoprotein B, Apolipoprotein B/Apolipoprotein A1 ratio, Aspartate aminotransferase (AST), AST/ALT ratio, Bilirubin, Calcium, Calprotectin, Cholesterol, HDL-cholesterol, Creatinine kinase (CK), Creatinine, C-reactive protein, Cystatin C, Gamma-glutamyl transferase (GGT), Iron, Iron saturation, Lactate dehydrogenase (LDH), Magnesium, Phosphate, Transferrin, Triglycerides, Urate, Urea, Zink, Hemoglobin, Platelet count and White blood cell count in an 80-year old population (n=531, 266 females and 265 males). There were significant Spearman rank associations between BMI and laboratory test results for several of the studied markers in both females and males. The strongest associations with BMI were noted for ALT, Apolipoprotein A1, HDL-cholesterol, Hemoglobin, CRP, Cystatin C, Triglycerides and Urate. In conclusion, several of the most frequently used laboratory markers are significantly associated with BMI. To be able to correctly interpret a test result it is important to be aware of the effects of BMI on the test results.


1997 ◽  
Vol 36 (01) ◽  
pp. 11-16 ◽  
Author(s):  
J. O. O. Hoeke ◽  
B. Bonke ◽  
R. van Strik ◽  
E. S. Gelsema ◽  
R. Verheij

Abstract:Four tabular and two graphical techniques for the presentation of laboratory test results were evaluated in a reaction-time experiment with 25 volunteers. Artificial variables and values were used to represent sets of 12 laboratory tests to eliminate the possible effects of clinical experience. Analyses focused on reaction times for correctly classified sets of data. For comparable data sets, Presentation Techniques (PT) that use color, always allow faster interpretation than PTs that do not use color, or use only a simple marker. Color-coded tables yielded an improvement in median reaction time of approximately six times or better, as compared to the reference PT (a tabular PT without any hints). For the color-coded graphs, the improvement rate was approximately 2.5 or better.


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