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Cutting Fluids
Published in David A. Stephenson, John S. Agapiou, Metal Cutting Theory and Practice, 2018
David A. Stephenson, John S. Agapiou
Air–oil mists, consisting of small droplets of water-based oil mixed with air, have been successfully applied as cutting fluids in many applications. Historically, they were used in high-speed applications with small areas of cut, for example, end-milling applications [3]. With the development of through-spindle coolant systems, they have been increasingly restricted to low-speed cutting applications such as drilling, gear machining, and sawing operations. There are two methods of producing mists: aspirator methods and direct-pressure methods [4]. In aspirator systems, a stream of air is directed past an open tube containing oil, creating a partial vacuum, which draws oil droplets into the air stream. In direct-pressure systems, compressed air is directed through the oil to create a mist. Oil mists are best suited to applications in which flood coolant is impractical, for example, in applications in which the cutting zone is relatively inaccessible, and on large machines. Their major disadvantages are a tendency for the nozzles to clog and exposure of the operator to mist inhalation, which has adverse health consequences as discussed in Section 14.6. Lean air–oil mists are also used in minimum quantity lubrication (MQL) systems as described in Chapter 15.
May allergy have a role in primary or recurrent otitis media in Egyptian pediatric patients: a prospective study
Published in Egyptian Journal of Basic and Applied Sciences, 2021
Mohammed El-Shahat, Asser ElSharkawy, Doaa Shahin, Ghada Barakat, Waleed Moneir
Symptoms of allergic rhinitis were found to affect 64.4% of the studied children. A higher frequency of allergic rhinitis symptoms in OME patients was in Alles et al. [17] study who stated symptoms of AR in 89% of studied group (209 children) but this may be due to larger study group than ours. But these results agree also with Martines et al. [18] who found Symptoms of allergic rhinitis in 60% of OME children. This study disagrees with Cassano et al. [19] and Martines et al. [18] who found that neither OME nor Eustachian tube dysfunction is significantly affected by the allergic reactions. The study results revealed that frequency of bronchial asthma was 32.2% of patients in agreement with Alles et al. [17] and Passali et al. [20] studies who found bronchial asthma in 36% and 37% of OME patients, respectively. Chantzi et al. [15] stated that bronchial asthma was the most straightforward target for a possible intervention, the effectiveness of appropriate asthma medications in prophylaxis, and treatment of OME. As regard food allergy history, it was e positive in 10.2% of studied children and this agrees with Döner et al. [21] who found a higher prevalence of food allergy in OME patients than in controls. Collection of MEE samples was collected by many methods Gomaa et al. [1] and El-Sharnoby et al. [22] obtained effusion fluid samples from patients by using wide bore (5 ml.) syringe in their clinical studies. But Lino et al. [23], Kanazawa et al. [24] and Saliba et al. [25] collected MEE samples using a JuhnTym-Tap middle ear fluid aspirator/collector in their clinical studies.
Sampling efficiency of low-volume PM10 inlets with different impaction substrates
Published in Aerosol Science and Technology, 2019
Thi-Cuc Le, Krishna Kumar Shukla, Jung-Che Sung, Ziyi Li, Huajun Yeh, Wei Huang, Chuen-Jinn Tsai
Figure 1 shows the schematic diagram of the modified PM10 (M-PM10) impactor with an oil-soaked GFF substrate supported by a PMD. A circular cavity (diameter (D) × depth (H) = 25 × 4.5 mm or 25 × 3.5 mm) is drilled at the center of the impaction plate to contain the 25-mm PMD and the GFF. A small amount of vacuum oil of 1.3 mL (TT-DM-100, Lisons Chemical Co., Ltd., Taiwan) for the cavity depth of 4.5 mm is added to fill up the cavity. The oil-soaked GFF substrate is expected to overcome particle bounce and capture more particles as the oil with low viscosity (∼100 mm2 s−1) can be retained on the GFF against air flow very well and wick up through the particle deposit to maintain a viscous impaction surface. The PMD is used to enhance the capillary action and increase the particle loading on the substrate. The M-PM10 impactor with the new impaction substrate as well as the conventional PM10 impactors were first tested at the laboratory for determining the cut-size and the penetration curve sharpness and then at the field after assembling with the aspirator section for evaluating the sampling performance.
Copper(II) halide complexes of aminopyridines: Syntheses, structures and magnetic properties of [(5CAP)2CuX2] and [(5BAP)nCuX2] (X = Cl, Br)
Published in Journal of Coordination Chemistry, 2018
Penelope C. Farris, Alexander D. Wall, Jonathan E. Chellali, Carina L. Chittim, Christopher P. Landee, Mark M. Turnbull, Jan L. Wikaira
The observation that the reaction of 5BAP with CuCl2 proceeds without grinding after the materials are initially mixed is surprising, but may provide insight into the actual process of these reactions. Although it is possible that the reaction occurs between two solids phases, it seems more reasonable that the reaction is solid-vapor rather than solid-solid given the fact that it does proceed even after grinding is stopped. 5BAP does sublime readily under aspirator vacuum, as does 5CAP, indicating that it has a significant vapor pressure. Similar observations were made in the reaction of 5CAP with CuCl2. The apparent effect of water vapor on the rate of the reaction is more puzzling, given the absence of water in the IR spectra after initial grinding. However, the potential exists for the formation of an azeotrope between 5BAP and water which, assuming it is a minimum boiling azeotrope, could raise its vapor pressure and therefore accelerate the reaction. More detailed work in this area, including precise measurement of the vapor pressures of 5BAP, 5CAP and related ligands in the presence and absence of water vapor are in progress to provide additional insight into this process.