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Quiet Zone for the patient in an Ambulance : Active Noise Control Technology for Siren Noise Reduction

Sharma M. K., Vig R., Pal R., Shantharam V.

Archives of Acoustics

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2018

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Vol. 43, No. 2

275--281

EN

This paper proposes an active noise control (ANC) application to attenuate siren noise for the patient lying inside ambulance with no sound proofing. From the point of cost effectiveness, a local ANC system based on feedforward scheme is considered. Further, to handle the limitation of limited Zone of Silence (ZoS), the ANC based on virtual sensing is explored. The simulations are done in MATLAB for the recorded ambulance siren noise signal. The results indicate that ANC can be an effective solution for creating a silent environment for the patient.

2

Corrosion Inhibition of Mild Steel in Nitric Acid Media by some Schiff Bases Derived from Anisalidine

Saxena N., Kumar S., Sharma M. K., Mathur S. P.

Polish Journal of Chemical Technology

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2013

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Vol. 15, nr 1

61-67

EN

Corrosion inhibition performance of mild steel in nitric acid solution containing different concentration of anisalidine derivative Schiff bases viz. N- (4-nitro phenyl) p-anisalidine (SB1), N- (4-chloro phenyl) p-anisalidine (SB2), N- (4-phenyl) p-anisalidine (SB3), N- (4-methoxy phenyl) p-anisalidine (SB4), N- (4-hydroxy phenyl) p-anisalidine (SB5) has been investigated using mass loss, thermometric and potentiostate polarization technique. Inhibition efficiencies of Schiff bases have been evaluated at different acid strength. The inhibition efficiency was found larger than their parent amines. Inhibition efficiencies of synthesized Schiff bases increase with inhibitor concentration. Inhibition efficiency increases up to 98.32% with ansalidine derivative Schiff base.

3

Analysis of tantalum loaded tributyl phosphate for the content of major, minor and trace elements using microwave decomposition and ICP-OES

Anil G., Reddy M. R. P., Sharma M. K., Kumar A., Prakash T. L.

Chemia Analityczna

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2004

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Vol. 49, No. 4

459-465

EN

Tantalum was extracted from the tantalite-columbite ore solution using tributyl phosphate (TBP) as a solvent. TBP containing tantalum and trace impurities were next decomposed applying a microwave digestion and the mixture of HNO3, H2O2 and HF acids. The procedure was conducted in the microwave vessel at low and high temperatures. It was found that under cold conditions NO2 and CO2 liberated during the digestion were dissolved completely in the solution. In contrast, under hot conditions (60-80°C) dissolution was not complete, which influenced the acidity of the solution and affected analysis results. The accuracy of the proposed method was evaluated by recovery experiments (TBP spiked with metal cations) and the results ranged between 94-102%.

PL

Tantal wyekstrahowano z roztworu rudy fantalit (kolumbit) stosując fosforan tributylu {TBP) jako rozpuszczalnik. TBP zawierający tantal i śladowe zanieczyszczenia został następnie rozłożony działaniem mikrofal i mieszaniny kwasów HNO(3), i HF oraz H202. Proces przeprowadzono w naczyniu mikrofalowym stosując niskie i wysokie temperatury. Stwierdzono, że w niskiej temperaturze, uwalniane podczs rozkładu NO(2) i CO(2), rozpuszczają się całkowicie w roztworze, natomiast w warunkach wysokiej temperatury rozpuszczenie nie zachodziło całkowicie, co miało wpływ na kwasowość roztworu i wyniki analizy. Dokładność proponowanej metody badano dodając do TBP kationy metali. Uzyskane odzyski mieściły się w granicach 94-102%.