Potential of Modern Lubricoolant Strategies on Cutting Performance

2013 ◽  
Vol 554-557 ◽  
pp. 2062-2071 ◽  
Author(s):  
Fritz Klocke ◽  
Dieter Lung ◽  
Alexander Krämer ◽  
Tolga Cayli ◽  
Hubertus Sangermann
Keyword(s):  
High Pressure ◽  
Flow Rate ◽  
High Performance ◽  
Minimum Quantity Lubrication ◽  
Cutting Parameters ◽  
Cryogenic Cooling ◽  
Fundamental Research ◽  
The Media ◽  
Tool Technology ◽  
Positive Effect

Besides developments in the area of dry machining and minimum quantity lubrication, the use of coolant lubricants is still essential when machining high alloyed steels or heat resistant materials like titanium and nickel based alloys. Experts agree that this fact will not change in the next decade. For this reason it is necessary to use coolant lubricants as effectively as possible to maximise their positive effect on productivity and process stability. High-performance cooling strategies like high-pressure cooling and cooling with cold gases (cryogenic cooling) have received increased attention in the last years. Through the targeted supply of coolant lubricants to the cutting site it is possible to decrease tool wear, increase cutting speeds, guarantee defined chip breakage and chip transport and – in terms of cryogenic cooling – waive part cleaning. This paper shows current research results in the above mentioned field. Since the performance of a high-pressure coolant lubricant supply in turning difficult to cut materials has been shown in many previous papers, this paper focuses on the quantification of the potential in turning different steels, namely quenched and tempered but also stainless steel in comparison to the conventional flood cooling. Since energy efficiency is very crucial, pressure and flow rate have to be adjusted carefully and in accordance with the cutting parameters to guarantee best results with less energy. Moreover the effects of cryogenic cooling will be evaluated in comparison to high-pressure cooling and conventional flood cooling. In latter field, cutting tests were carried out under variation of the flow rate in order to find the minimum required value for a certain machining task with the overall aim to prevent waste of the media used. Especially in cryogenic cooling technologies, many fundamental research regarding the working mechanisms but also further developments in cutting tool and machine tool technology are still necessary to make this technology ready for industrial use.

Increasing Productivity and Process Stability in Turning of Aerospace Materials with High Pressure Lubricoolant Supply

2016 ◽  
Vol 836-837 ◽  
pp. 48-55 ◽  
Author(s):  
Fritz Klocke ◽  
Tolga Cayli ◽  
Dražen Veselovac
Keyword(s):  
High Pressure ◽  
Flow Rate ◽  
Cutting Parameters ◽  
Experimental Investigations ◽  
Process Stability ◽  
Aerospace Materials ◽  
Tool Temperature ◽  
Temperature Reference ◽  
Cutting Zone ◽  
Cooling And Lubrication

In the field of machining difficult-to-cut materials like titanium or nickel-based alloys, the use of a high-pressure lubricoolant supply may result in a significant increase of productivity and process stability. Due to enhanced cooling and lubrication of the cutting zone and thus reduced thermal tool load, tool wear can be decreased which allows higher applicable cutting speeds. Furthermore, the process stability can be increased as a result of effective chip breaking and chip evacuation. Since energy efficiency is very crucial, pressure and flow rate have to be adjusted carefully and in accordance with the cutting parameters to guarantee best results with less energy. For this purpose, experimental investigations were carried out under variation of the flow rate in order to find the minimum required value for a certain machining task with the overall aim to prevent waste of the media used. To maximize the positive effect of high pressure lubricoolant supply strategy on productivity and process stability, specially designed lubricoolant jet guidance geometry on the rake face was also investigated and compared to conventional turning inserts. To study the effect of high-pressure lubricoolant supply on tool temperature, reference tests also carried out using conventional overflood cooling (CoC). The results suggest that the tool temperature can be significantly decreased compared to CoC by applying the high pressure lubricoolant supply and using specially designed jet guidance geometry in turning the investigated aerospace materials TiAl6V4 and Inconel 718.

The Effect of High Pressure Abrasive Water Jet Cutting Parameters on Cutting Performance of Granite

2006 ◽  
Vol 304-305 ◽  
pp. 560-564 ◽  
Author(s):  
Chuan Zhen Huang ◽  
Rong Guo Hou ◽  
Jun Wang ◽  
Yan Xia Feng
Keyword(s):  
High Pressure ◽  
Mass Flow Rate ◽  
Flow Rate ◽  
Water Pressure ◽  
Cutting Parameters ◽  
Traverse Speed ◽  
Kerf Width ◽  
Standoff Distance ◽  
Abrasive Water Jet ◽  
Kerf Taper

The effect of cutting parameters such as water pressure, nozzle traverse speed and standoff distance on the granite cutting performance as characterized by kerf width, kerf taper, and striation drag angle are researched with a series of experiments using garnetabrasive and ultra high pressure abrasive water jet numerical control machine tool. The relationship between system pressure and abrasive mass flow rate is also studied. The research results show that the abrasive mass flow rate is only proportional to water pressure and the effect of other cutting parameters is not significant. It is found that an increase in water pressure is associated with an increased kerf width and a decreased kerf taper. The kerf width decreases with the enhancement of nozzle traverse speed, and resulting in a significant increase in kerf taper as the nozzle traverse speed increases. The kerf width increases with the enhancement of standoff distance, and hence it causes a significant increase in kerf taper at the standoff distance domain from 3mm to 4mm and then a little decrease in kerf taper at the standoff distance increasing from 4mm to 5mm. The striation drag angle decreases with an increase in water pressure and a decrease in nozzle traverse speed.

Effect of Compensation and Work Environment on Employee Performance with Employee Job Satisfaction as an Intervening Variable

2018 ◽  
Vol 9 (03) ◽  
pp. 20553-20562
Author(s):  
Putu Ayu Diah Juliarti ◽  
Anak Agung Putu Agung ◽  
I Nengah Sudja
Keyword(s):  
Job Satisfaction ◽  
Work Environment ◽  
High Performance ◽  
Employee Performance ◽  
Statistical Tests ◽  
Path Coefficient ◽  
Significant Positive Effect ◽  
Organizational Goals ◽  
Record Keeping ◽  
Positive Effect

An employee who has a high performance and better able to support the achievement of the goals and objectives set by the company. Employees can work well if you have a high performance that can produce good work anyway. With the high- performance that employees, is expected to achieve organizational goals. This study examines the effect of compensation and work environment on employee performance with job satisfaction to be intervening variable. Data on compensation, work environment, job satisfaction, and employee performance obtained through observation, record keeping and questioner with respondents. The data obtained are then analyzed using Partial Least Squares (PLS). Statistical tests results showed  (1) the compensation proved significant positive effect on job satisfaction the path coefficient of 0.434 and T-Stats for 4.880, (2) work environment proved to be a significant positive effect on job satisfaction the path coefficient of 0.434 and T-Stats for 4.074, (3) job satisfaction proved to be a significant positive effect on employee performance the path coefficient of 0.264 and T-Stats for 2.458, (4) compensation proved positive and significant effect employee performance the path coefficient of 0.242 and T-Stats for 2.912, (5) work environment proved positive and significant effect employee performance the path coefficient of 0.378 and T-Stats for 3.343. Based on test results obtained statistical results of all variables positive and signicant impact.

Optimum HPLC Conditions for Determination of Dibucaine HCL, Fluocortolone Pivalate and Fluocortolone Caproate by Using Experimental Design

2018 ◽  
Vol 15 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Bürge Aşçı ◽  
Mesut Koç
Keyword(s):  
Experimental Design ◽  
Flow Rate ◽  
Mobile Phase ◽  
High Performance ◽  
Limit Of Detection ◽  
Pharmaceutical Preparations ◽  
Acid Mixture ◽  
Solution Stability ◽  
Uv Detector

Introduction:This paper presents the development and validation of a novel, fast, sensitive and accurate high performance liquid chromatography (HPLC) method for the simultaneous quantitative determination of dibucaine HCl, fluocortolone pivalate and fluocortolone caproate in pharmaceutical preparations.Experiment:Development of the chromatographic method was based on an experimental design approach. A five-level-three-factor central composite design requiring 20 experiments in this optimization study was performed in order to evaluate the effects of three independent variances including mobile phase ratio, flow rate and amount of acid in the mobile phase.Conclusion:The optimum composition for mobile phase was found as a methanol:water:acetic acid mixture at 71.6 : 26.4 : 2 (v/v/v) ratio and optimum separation was acquired by isocratic elution with a flow rate of 1.3 mL/min. The analytes were detected using a UV detector at 240 nm. The developed method was validated in terms of linearity, precision, accuracy, limit of detection/quantitation and solution stability and successfully applied to the determination of dibucaine HCl, fluocortolone pivalate and fluocortolone caproate in pharmaceutical topical formulations such as suppositories and ointments.

scholarly journals Development and validation of RP-HPLC method for estimation of brexpiprazole in its bulk and tablet dosage form using Quality by Design approach

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Amol S. Jagdale ◽  
Nilesh S. Pendbhaje ◽  
Rupali V. Nirmal ◽  
Poonam M. Bachhav ◽  
Dayandeo B. Sumbre
Keyword(s):  
Flow Rate ◽  
High Performance ◽  
Reversed Phase ◽  
Hplc Method ◽  
Control Analysis ◽  
Uv Detector ◽  
Mobile Phase Flow Rate ◽  
Rp Hplc ◽  
Quality By Design Approach ◽  
Bulk Drug

Abstract Background A new, sensitive, suitable, clear, accurate, and robust reversed-phase high-performance liquid chromatography (RP-HPLC) method for the determination of brexpiprazole in bulk drug and tablet formulation was developed and validated in this research. Surface methodology was used to optimize the data, with a three-level Box-Behnken design. Methanol concentration in the mobile phase, flow rate, and pH were chosen as the three variables. The separation was performed using an HPLC method with a UV detector and Openlab EZchrom program, as well as a Water spherisorb C18 column (100 mm × 4.6; 5m). Acetonitrile was pumped at a flow rate of 1.0 mL/min with a 10 mM phosphate buffer balanced to a pH of 2.50.05 by diluted OPA (65:35% v/v) and detected at 216 nm. Result The developed RP-HPLC method yielded a suitable retention time for brexpiprazole of 4.22 min, which was optimized using the Design Expert-12 software. The linearity of the established method was verified with a correlation coefficient (r2) of 0.999 over the concentration range of 5.05–75.75 g/mL. For API and formulation, the percent assay was 99.46% and 100.91%, respectively. The percentage RSD for the method’s precision was found to be less than 2.0%. The percentage recoveries were discovered to be between 99.38 and 101.07%. 0.64 μg/mL and 1.95 μg/mL were found to be the LOD and LOQ, respectively. Conclusion The developed and validated RP-HPLC system takes less time and can be used in the industry for routine quality control/analysis of bulk drug and marketed brexpiprazole products. Graphical abstract

4-Nitrophenol in 4-nitrophenyl phosphate, a substrate for alkaline phosphatase, as measured by paired-ion high-performance liquid chromatography.

1977 ◽  
Vol 23 (12) ◽  
pp. 2288-2291 ◽  
Author(s):  
P H Culbreth ◽  
I W Duncan ◽  
C A Burtis
Keyword(s):  
Alkaline Phosphatase ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Flow Rate ◽  
Mobile Phase ◽  
High Performance ◽  
Reversed Phase ◽  
Nitrophenyl Phosphate ◽  
Phase Column ◽  
Reversed Phase Column

Abstract We used paired-ion high-performance liquid chromatography to determine the 4-nitrophenol content of 4-nitrophenyl phosphate, a substrate for alkaline phosphatase analysis. This was done on a reversed-phase column with a mobile phase of methanol/water, 45/55 by vol, containing 3 ml of tetrabutylammonium phosphate reagent per 200 ml of solvent. At a flow rate of 1 ml/min, 4-nitrophenol was eluted at 9 min and monitored at 404 nm; 4-nitrophenyl phosphate was eluted at 5 min and could be monitored at 311 nm. Samples of 4-nitrophenyl phosphate obtained from several sources contained 0.3 to 7.8 mole of 4-nitrophenol per mole of 4-nitrophenyl phosphate.

scholarly journals Does the “Miracle Drug” of Environmental Governance Really Improve Air Quality? Evidence from China’s System of Central Environmental Protection Inspections

2019 ◽  
Vol 16 (5) ◽  
pp. 850 ◽  
Author(s):  
Ruxin Wu ◽  
Piao Hu
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Environmental Protection ◽  
Treatment Effect ◽  
Local Governments ◽  
Environmental Governance ◽  
Central Government ◽  
Local Officials ◽  
The Media ◽  
Positive Effect

Central environmental protection inspections have completed their goal of full coverage of 31 provinces in China, and more than 17,000 officials have been held accountable. The media has evaluated the effectiveness of central environmental protection inspections using the notions of “instant results” and the “miracle drug of environmental governance.” Can this approach effectively promote local environmental governance? This paper takes the treatment effect of central environmental protection inspections on air pollution as an example. Using the method of regression discontinuity, central environmental protection inspections are found to have a positive effect on the air quality index (AQI), but this effect is only short term and unsustainable. Additionally, there are inter-provincial differences. Judging from the research results on sub-contaminants, the treatment effect of central environmental protection inspections on air pollution is mainly reflected in PM10, PM2.5 and CO. Under the current situation in which PM10 and PM2.5 are the main assessment indexes, this phenomenon indicates that due to the political achievements and promotion of local officials and for reasons of accountability, it is more effective for the central government to conduct specific environmental assessments through local governments than to conduct central environmental protection inspections.

The Role of Porous Media in Homogenization of High Pressure Diesel Fuel Spray Combustion

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
Navid Shahangian ◽  
Damon Honnery ◽  
Jamil Ghojel
Keyword(s):  
High Pressure ◽  
Porous Media ◽  
High Speed ◽  
Fuel Spray ◽  
Compression Ignition Engines ◽  
System Pressure ◽  
Novel Approach ◽  
Air Mixing ◽  
The Media

Interest is growing in the benefits of homogeneous charge compression ignition engines. In this paper, we investigate a novel approach to the development of a homogenous charge-like environment through the use of porous media. The primary purpose of the media is to enhance the spread as well as the evaporation process of the high pressure fuel spray to achieve charge homogenization. In this paper, we show through high speed visualizations of both cold and hot spray events, how porous media interactions can give rise to greater fuel air mixing and what role system pressure and temperature plays in further enhancing this process.

Effect of Recirculation Device With Counter Swirl Vane on Performance of High Pressure Ratio Centrifugal Compressor

2011 ◽  
Author(s):  
Hideaki Tamaki
Keyword(s):  
High Pressure ◽  
Mach Number ◽  
Flow Rate ◽  
Centrifugal Compressor ◽  
Pressure Ratio ◽  
Negative Slope ◽  
Tip Leakage Flow ◽  
Recirculation Flow ◽  
Operating Range ◽  
High Pressure Ratio

Centrifugal compressors used for turbochargers need to achieve a wide operating range. The author has developed a high pressure ratio centrifugal compressor with pressure ratio 5.7 for a marine use turbocharger. In order to enhance operating range, two different types of recirculation devices were applied. One is a conventional recirculation device. The other is a new one. The conventional recirculation device consists of an upstream slot, bleed slot and the annular cavity which connects both slots. The new recirculation device has vanes installed in the cavity. These vanes were designed to provide recirculation flow with negative preswirl at the impeller inlet, a swirl counterwise to the impeller rotational direction. The benefits of the application of both of the recirculation devices were ensured. The new device in particular, shifted surge line to a lower flow rate compared to the conventional device. This paper discusses how the new recirculation device affects the flow field in the above transonic centrifugal compressor by using steady 3-D calculations. Since the conventional recirculation device injects the flow with positive preswirl at the impeller inlet, the major difference between the conventional and new recirculation device is the direction of preswirl that the recirculation flow brings to the impeller inlet. This study focuses on two effects which preswirl of the recirculation flow will generate. (1) Additional work transfer from impeller to fluid. (2) Increase or decrease of relative Mach number. Negative preswirl increases work transfer from the impeller to fluid as the flow rate reduces. It increases negative slope on pressure ratio characteristics. Hence the recirculation flow with negative preswirl will contribute to stability of the compressor. Negative preswirl also increases the relative Mach number at the impeller inlet. It moves shock downstream compared to the conventional recirculation device. It leads to the suppression of the extension of blockage due to the interaction of shock with tip leakage flow.

Flank-milling of Integral Blade Rotors made in Ti6Al4V using cryo CO2 and Minimum Quantity Lubrication (MQL)

2021 ◽  
pp. 1-16
Author(s):  
Haizea Gonzalez ◽  
Octavio Pereira ◽  
Luis Norberto López de Lacalle ◽  
Amaia Calleja ◽  
Izaro Ayesta ◽  
...  
Keyword(s):  
Gas Turbines ◽  
Cutting Tools ◽  
Minimum Quantity Lubrication ◽  
Cryogenic Cooling ◽  
Flank Milling ◽  
New Device ◽  
Minimum Quantity ◽  
Cutting Zone ◽  
Oil Emulsions ◽  
Pcd Tools

Abstract This paper presents the machining of Ti6Al4V Integral Blade Rotors (IBR) using CO2 as cryogenic cooling. This kind of component is typical in gas turbines, pumps and other rotary machines. Flank milling technique using diamond polycrystalline (PCD) tools using CO2 and Minimum Quantity Lubrication (MQL), denominated CryoMQL, is an alternative to conventional oil emulsions. The proposed approach implies a balance between technical and environmental issues, and it makes feasible the use PCD tools avoiding the high temperature reactivity of Ti6Al4V alloy with this type of cutting tools. CO2 must be supplied and injected onto the cutting zone, avoiding the risks of dry ice formation and clogging of both pipes and nozzles. For this purpose, a new device for CO2 delivery was developed, using gas and liquid CO2.

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