Wyniki wyszukiwania - BazTech

1

Modelling of regeneration and filtration mechanism in diesel particulate filter for development of composite regeneration emission control system

Kurien C., Srivastava A. K., Naudin J.

Archive of Mechanical Engineering

|

2018

|

Vol. LXV, nr 2

277--290

EN

Pre-treatment techniques employed for exhaust emission control of compression ignition engines were found to reduce the emission levels by small percentage only, failing to meet the required emission regulations. Post-treatment technique including diesel particulate ﬁltration, diesel oxidation catalysis and selective catalytic reduction is found to be an eﬀective solution. While the fuel-based regeneration of diesel particulate ﬁlter leads to uncontrolled combustion aﬀecting the durability of the ﬁlter. Development of an eﬀective regeneration system is one of the major technical challenges faced by automotive industry for meeting emission norms. A composite regeneration system with the application of microwave energy is proposed in this paper. As an initial phase, a three-dimensional model of the system is developed and its ﬂow analysisis carried out by considering the case of single channel ﬂow. Simulation of the regeneration process is also done by developing a Simulink model. The results of simulation showed that an engine running continuously for a period of 24 hours would require three regenerations.

2

Humidity sensing properties of TiO2-Sb2O5 nanocomposite

Srivastava A. K., Yadav B. C.

Materials Science Poland

|

2010

|

Vol. 28, No. 2

491--502

EN

The syntheses of TiO2-Sb2O5 (AT) composites were investigated by the conventional precipitation method and their use as humidity sensors. 2-50 wt. % of Sb2O5 was added to TiO2 and pellets were made under the pressure of 616 MPa a room temperature of 30°C. The pellets were annealed at various temperatures (200, 500, 700 and 800 °C) for 3 h and the humidity sensing properties of each pellet were studied. A saturated aqueous solution of potassium sulphate was used as the humidifier and a saturated solution of potassium hydroxide was used as the dehumidifier. Upon increasing relative humidity (RH) inside the test chamber, the resistance of each pellet decreased for the RH range from 10% to 95%. Samples of the sensor material, differing in the percentage of the additive, were subject to SEM and XRD analysis. The minimum grain size, estimated from SEM, was 30 nm and the minimum crystallite size from XRD data was 20 nm. The material was found to have suitable properties to be applied as a resistive humidity sensor operating over the entire humidity range.

3

Chelating sorbent for heavy mental ions obtained by modification of an anion-exchange resin with diethyldithiocarbamate

Singh A., Srivastava A.K.

Chemia Analityczna

|

2009

|

Vol. 54, No. 2

257-267

EN

A new chelating sorbent for heavy metal ions was prepared by modification of a strongly basic Ceralite IR 400 resin with diethyldithiocarbamate (DDTC). Ceralite IR 400-DDTC resin was characterized on the basis of FTIR spectra and sorption capacity. The breakthrough and overall capacities for Cu2+, Pb2+, Zn2+, Cd2+, Co2+ Ni2+, Hg2+, Mn2+ and Fe2+ were determined. Distribution coefficients (Kd) were studied at pH 1,2,4, and 6. The resin retained the tested heavy metal ions, while no sorption was observed for alkali and alkaline earth metal ions in the investigated pH range. The resin exhibited the highest breakthrough capacity (0.82 mmol g-1dry resin) and selectivity (highest K.d) for Cu2+. Sorption properties of the resin should be ascribed to the contribution of the bridging sulfur of DDTC to selective coordination of metal ions. On the basis of Kd values, quantitative separations of Cu2+ from Zn2+, Cd2+ and Mn2+, and Zn2+ from Fe2+and Hg2+ were achieved. The column was also used for removal and recovery of Cu2+ from water samples. The sorption behavior followed the Freundlich adsorption isotherms.

PL

Przygotowano nowy sorbent chelatujący jony ciężkich metali przez modyfikację silnie zasadowego anionitu Ceralitu 1R 400 za pomocądietyloditiokarbaminianu (DDTC). Jonit Ceralit IR 400-DDTC scharakteryzowano na podstawie widm FTIR oraz pomiarów zdolności sorpcyjnej. Wyznaczono całkowite pojemności i pojemności do przebicia dla Cu2+, Pb2+, Zn2+, Cd2+, Co2+, Ni2+, Hg2+, Mn2+ i Fe3+. Badano także współczynniki podziału (Kd) przy pH l, 2,4 i 6. Jonit zatrzymywał badane jony metali ciężkich, natomiast nie zaobserwowano żadnej sorpcji jonów metali alkalicznych i ziem alkalicznych w badanym zakresie pH. Największą pojemność do przebicia (0,82 mmol g-1 suchego jonitu) i najlepszą selektyw-ność (najwyższa warość Kd) obserwowano dla jonów Cu2+ . Sorpcyjne właściwości jonitu można przypisać oddziaływaniu mostka siarkowego DDTC na selektywne wiązanie jonów metalicznych. Korzystając z różnic wartości Kd przeprowadzono selektywne oddzielanie Cu2+ od Zn2+, Cd2+ od Mn2+ oraz Zn2+od Fe3+ i Hg2+. Kolumnę z jonitem stosowano także do odzysku Cu2+ z próbek wody. Zachowanie sorpcyjne jonitu można było dobrze opisać za pomocą izotermy adsorpcji Freundlicha.