Stability analysis of hybrid Al2O- TiO2 nano-cutting fluids

Purpose: This paper is to study the stability of the current combination of hybrid nano-cutting fluids due to the recent progress in the analysis of nano-cutting fluids, such as the assessment methods for the stability of nano-cutting fluids, have revealed that instability is a common problem associated with nano cutting fluids. Design/methodology/approach: Five samples of 0.001 vol% that are suitable to be tested at UV-Vis machine, Al2O3–TiO2 hybrid nano-cutting fluid was prepared using a one-step process with the help of a magnetic stirrer to stir for 30 minutes with different sonication time to determine the best or optimum sonication time for this hybrid nano-cutting fluid. Stability of nano-cutting fluids was analyses using UV–Vis spectrophotometer (0.001%, 0.0001%, 0.00001%), visual sedimentation (1%, 2%, 3%, 4%), TEM photograph capturing techniques (2%) and zeta potential analysis (0.001%, 0.00001%), that used different volume concentration that is suitable for each type of stability analysis. Findings: The stability analysis reveals that the best sonication time is 90 minutes, and the UV-vis spectrophotometer shows the stability of all samples is above 80% during a month compared to the initial value. Further, visual sedimentation shows good stability with minimum sedimentation and colour separation only. The zeta potential value also shows great stability with a value of 37.6 mV. It is found that the hybrid nano-cutting fluid is stable for more than a month when the nano is suspended in the base fluid of conventional coolant. Research limitations/implications: The result in this paper is based on the experimental study of Al2O3-TiO2/CNC coolant base hybrid nano-cutting fluid for a month. However, to further validate the results presented in this paper, it is recommended to prolong the stability assessment time for six months for longer shelf life. Practical implications: The finding of this experimental study can be useful for high-precision product machining using similar CNC coolants, especially for aircraft and airspace applications for machining parts. Originality/value: No thorough stability assessment using all four types of stability analysis is done on Al2O3-TiO2/CNC Coolant base hybrid nano cutting fluid

Students' perceptions about learning pharmacology at a single private institute in Malaysia

AbstractObjectiveUnderstanding current perceptions of medical students regarding learning pharmacology and understanding pharmacology's important role in both clinical practice and research may be helpful in improving the teaching of this discipline. This study was conducted to evaluate medical students' opinions toward pharmacology.MethodsOne hundred fifty medical students, randomly selected from the Management and Sciences University (MSU) in Malaysia, completed a self-administered questionnaire that inquired concerning their views toward learning pharmacology.ResultsThe majority (75.3%), of the participants were female and (68%) were Malays whose parents were non-medical professionals (88.7–95.3%). The average percentage of respondents agreeing to participate (47.15 ± 11.69) was highly significant (p < 0.0001) compared with the average percentage of respondents that disagreed (9.97 ± 3.15). The percentage of students that considered pharmacology as a favoured subject and a choice for post-graduate studies was significantly lower (p < 0.05) compared with the percentage that did not, although the students that agreed were less than 30% of the total participants.ConclusionsThe study found that the general perceptions of students regarding the study of pharmacology were positive. Nevertheless, the study also exposed the need for concerted efforts to make learning pharmacology an interesting experience and to identify priority areas for such improvements

Effectiveness of hybrid Al2O3-TiO2 nano cutting fluids application in CNC turning process

Purpose: The purpose of this study is to evaluate the effectiveness of hybrid Al2O3-TiO2 nano-cutting fluid in the turning process application under the selected significant machining parameters consisting of nano concentration, depth of cut and feed rate. Design/methodology/approach: The preparation of aqueous hybrid Al2O3-TiO2 water-based nano-cutting fluids and their application as the cutting fluid in turning operations are undertaken. The Al2O3-TiO2 hybrid nano-cutting fluids were prepared through a one-step method; by dispersing nanoparticles of Al2O3 (average diameter 30 nm) and TiO2 (average diameter 30-50 nm) in CNC coolant based at four different volume concentrations (1%, 2%, 3%, 4%). The effectiveness of turning cutting performance, namely cutting temperature (°C), average surface roughness (Ra), and tool wear (%), were assessed via air-assisted nano cutting fluids impinged through MQL setup in turning of Aluminium Alloy AA7075. The response surface method (RSM) was employed in the design of the experiment (DOE). Findings: The lowest cutting temperature, surface roughness, and tool wear of 25.8°C, 0.494 μm, and 0.0107%, are obtained, respectively, when the combinations of hybrid nano cutting fluid concentration of 4%, feed rate value of 0.1 mm/rev, and 0.3 mm depth of cut is used. Research limitations/implications: The result in this paper is based on the experimental study of Al2O3-TiO2 hybrid nano-cutting fluid using CNC turning operation. The process focuses on the finishing process by using a finishing insert. Further work using roughing process may be suggested to observe the better performance of this cutting process using nano-cutting fluid towards reducing the wear rate. Practical implications: The use of Al2O3-TiO2 hybrid nano-cutting fluid coupled with MQL in the CNC turning process is considered a new method. Machining soft and delicate materials such as Aluminium should consider using this combination technique since it lowers the cutting temperature and removes the chips, reducing the adhesive wear. Originality/value: The hybrid nano-cutting fluid can replace the conventional cutting fluid and will perform better if combined with the MQL cooling technique; this new method should be considered by major industry players that require a high-precision finished product such as the product that involves aircraft and aerospace applications

Stability analysis of hybrid Al2O3-TiO2 nano-cutting fluids

Purpose: This paper is to study the stability of the current combination of hybrid nano-cutting fluids due to the recent progress in the analysis of nano-cutting fluids, such as the assessment methods for the stability of nano-cutting fluids, have revealed that instability is a common problem associated with nano cutting fluids. Design/methodology/approach: Five samples of 0.001 vol% that are suitable to be tested at UV-Vis machine, Al2O3–TiO2 hybrid nano-cutting fluid was prepared using a one-step process with the help of a magnetic stirrer to stir for 30 minutes with different sonication time to determine the best or optimum sonication time for this hybrid nano-cutting fluid. Stability of nano-cutting fluids was analyses using UV–Vis spectrophotometer (0.001%, 0.0001%, 0.00001%), visual sedimentation (1%, 2%, 3%, 4%), TEM photograph capturing techniques (2%) and zeta potential analysis (0.001%, 0.00001%), that used different volume concentration that is suitable for each type of stability analysis. Findings: The stability analysis reveals that the best sonication time is 90 minutes, and the UV-vis spectrophotometer shows the stability of all samples is above 80% during a month compared to the initial value. Further, visual sedimentation shows good stability with minimum sedimentation and colour separation only. The zeta potential value also shows great stability with a value of 37.6 mV. It is found that the hybrid nano-cutting fluid is stable for more than a month when the nano is suspended in the base fluid of conventional coolant. Research limitations/implications: The result in this paper is based on the experimental study of Al2O3-TiO2/CNC coolant base hybrid nano-cutting fluid for a month. However, to further validate the results presented in this paper, it is recommended to prolong the stability assessment time for six months for longer shelf life. Practical implications: The finding of this experimental study can be useful for high-precision product machining using similar CNC coolants, especially for aircraft and airspace applications for machining parts. Originality/value: No thorough stability assessment using all four types of stability analysis is done on Al2O3-TiO2/CNC Coolant base hybrid nano cutting fluid