An experimental investigation into resonance dry grinding of hardened steel and nickel alloys with element of MQL

Current policies on environmental issues put extra pressures on manufacturing processes to be resource efficient and eco-friendly. However, in grinding processes, large amounts of cutting fluids are used. These fluids are not environmental friendly thus require proper management before disposal with associated cost. Hence, this work sets to explore low-frequency vibration in grinding in order to improve coolant application in conventional grinding at the first stage with the aim to introduce this into high efficiency deep grinding (HEDG) at latter stage. An attempt is made to grind nickel alloys with minimum quantity lubricant (MQL) as oppose to flood cooling. To achieve this with minimum alterations to the machine tool, a piezo-driven workpiece holder was developed for surface grinding. This simple innovative workpiece holder allowed oscillating during actual grinding process. However, this paper presents the results of low-frequency oscillatory grinding in dry and near-dry conditions. The response of the machine tool spindle unit is presented alongside with the workpiece holder response. In this investigation, hardened steels and nickel alloys were ground with vibration assistance. The grinding forces are illustrated together with the surface finish. The wheel performance is given in terms of grinding ratio

Synthesis of some benzopyranoquinoline derivatives

29-324-Chlorocoumarins on condensation with anthranilic acid afford 4-(2' -carboxyphenylamino )-<span style="font-size:13.5pt;mso-bidi-font-size:7.5pt;font-family:Arial;mso-bidi-font-style: italic">2H-(<span style="font-size:14.5pt;mso-bidi-font-size: 8.5pt">1)- benzopyran-2-ones 1 which on cyclisation with polyphosphoric acid yield 7,12-dihydro-6H-[1]benzopyrano[<span style="font-size:14.0pt;mso-bidi-font-size:8.0pt;font-family:Arial;mso-bidi-font-style: italic">4,3-b<span style="font-size:14.5pt;mso-bidi-font-size: 8.5pt">]quinoline-6,7-diones 2. Compounds 1 on treatment with phosphoryl chloride yield 7-chlorobenzopyrano[4,3-b]quinolin-6(H)-ones <b style="mso-bidi-font-weight: normal">3. These chloro compounds on further treatment with various aromatic amines yield 7-anilinobenzopyrano[4,3-<i style="mso-bidi-font-style: normal">b]quinolin-6(H)-ones 4.<span style="font-size:16.0pt; mso-bidi-font-size:10.0pt"> </span

Synthesis of some antimicrobial pyranocarbazomycins

1477-1479Carbazomycins have been synthesized by condensation of diazotised 6-aminocoumarins 2a-c with 2-hydroxymethylenecyclohexanone 3 under Japp-Klingemann method to afford the respective hydrazones 4a-c which on cyclisation with a mixture of acetic acid and hydrochloric acid give 4H, 11H-7 ,8,9,10-tetrahydro-4, 10-dioxo-pyrano[3,2-a]carbazoles 5a-c. Wolf-Kishner reduction of compounds 5a-c followed by dehydrogenation with Pd/C yield 4H, 11H pyrano[3,2-a]carbazoles 7a-c. The compounds 5a-b, 6a-b and 7a-b show inhibitory activity against gram-positive and gram-negative bacteria