Spectroscopic characteristics of the cyanomethyl anion and its deuterated derivatives

It has long been suggested that CH2CN- might be a carrier of one of the many poorly characterized diffuse interstellar bands. In this paper, our aim is to study various forms of CH2CN in the interstellar medium. Aim of this paper is to predict spectroscopic characteristics of various forms of CH2CN and its deuterated derivatives. Moreover, we would like to model the interstellar chemistry for making predictions for the column densities of such species around dark cloud conditions. A detailed quantum chemical simulations to present the spectral properties of various forms of the CH2CN. MP2 theory along with the aug-CCPVTZ basis set is used to obtain different spectroscopic constants of CH2CN-, CHDCN- and CD2CN- in the gas phase which are essential to predict rotational spectra of these species. We performed quantum chemical calculation to find out energetically the most stable spin states for these species. We have computed IR and electronic absorption spectra for different forms of CH2CN. Moreover, we have also implemented a large gas-grain chemical network to predict the column densities of various forms of the cyanomethyl radical and its related species. In order to mimic physical conditions around a dense cloud region, the variation of the visual extinction parameters are considered with respect to the hydrogen number density of the simulated cloud. Our quantum chemical calculation reveals that the singlet spin state is the most stable form of cyanomethyl anion and its deuterated forms. For the confirmation of the detection of the cyanomethyl anion and its two deuterated forms, namely, CHDCN- and CD2CN-, we present the rotational spectral information of these species in the Appendix. Our chemical model predicts that the deuterated forms of cyanomethyl radicals (specially the anions) are also reasonably abundant around the dense region of the molecular cloud.Comment: 55 pages, 4 figures, accepted for the publication in A&

Adopting Intercultural Communication Issue in Teaching English

Cultural assimilation and intercultural awareness has been an important hub of modern language and communication studies, underlining a shift that reflects a greater significance of the inseparability of language and culture, and the need to prepare students for effective intercultural communication to thrive in a global work environment. A thriving global workplace requires effective communication skill across cultures in this era of globalization and mass migration. Under the tutelage of such backdrop, this article addresses the terrain of adopting intercultural awareness in EFL classroom teaching/learning and aims at linking culture with language in pursuit of excellence in borderless effective communication. The study, in other words, investigated the linguistic aspects that could be affected by certain cultural dimensions (e.g., beliefs, traditions, taboo words, habits, and norms, religion, social factors, etc.) in intercultural communication. This paper uses a questionnaire device to receive some university teachers' self-reported feedback. This article maintains qualitative and quantitative research methodology. The analytical research result shows that in teaching English, it is necessary to incorporate and develop aspects of cross-cultural awareness as a part of course curriculum to immerse students in effective intercultural communicative competence (ICC)

Formation of Cyanoformaldehyde in the interstellar space

Cyanoformaldehyde (HCOCN) molecule has recently been suspected towards the Sagittarius B2(N) by the Green Bank telescope, though a confirmation of this observation has not yet been made. In and around a star forming region, this molecule could be formed by the exothermic reaction between two abundant interstellar species, H2CO and CN. Till date, the reaction rate coefficient for the formation of this molecule is unknown. Educated guesses were used to explain the abundance of this molecule by chemical modeling. In this paper, we carried out quantum chemical calculations to find out empirical rate coefficients for the formation of HCOCN and different chemical properties during the formation of HCOCN molecules. Though HCOCN is stable against unimolecular decomposition, this gas phase molecule could be destroyed by many other means, like: ion-molecular reactions or by the effect of cosmic rays. Ion-molecular reaction rates are computed by using the capture theories. We have also included the obtained rate coefficients into our large gas-grain chemical network to study the chemical evolution of these species in various interstellar conditions. Formation of one of the isotopologue(DCOCN) of HCOCN is also studied. Our study predicts the possibility of finding HCOCN and DCOCN in the ice phase with a reasonably high abundance. In order to detect HCOCN or DCOCN in various interstellar environments, it is necessary to know the spectroscopic properties of these molecules. To this effect, we carried out quantum chemical calculations to find out different spectral parameters of HCOCN for the transition in electronic, infrared and rotational modes. We clearly show how the isotopic substitution (DCOCN) plays a part in the vibrational progressions of HCOCN.Comment: 20 pages, 7 figure

Hydro-chemical study of the evolution of interstellar pre-biotic molecules during the collapse of molecular clouds

One of the stumbling blocks for studying the evolution of interstellar molecules is the lack of adequate knowledge of the rate co-efficients of various reactions which take place in the Interstellar medium and molecular clouds. Some of the theoretical models of rate coefficients do exist in the literature for computing abundances of the complex pre-biotic molecules. So far these have been used to study the abundances of these molecules in space. However, in order to obtain more accurate final compositions in these media, we find out the rate coefficients for the formation of some of the most important interstellar pre-biotic molecules by using quantum chemical theory. We use these rates inside our hydro-chemical model to find out the chemical evolution and the final abundances of the pre-biotic species during the collapsing phase of a proto-star. We find that a significant amount of various pre-biotic molecules could be produced during the collapsing phase of a proto-star. We study extensively the formation these molecules via successive neutral-neutral and radical-radical/radical-molecular reactions. We present the time evolution of the chemical species with an emphasis on how the production of these molecules varies with the depth of a cloud. We compare the formation of adenine in the interstellar space using our rate-coefficients and using those obtained from the existing theoretical models. Formation routes of the pre-biotic molecules are found to be highly dependent on the abundances of the reactive species and the rate coefficients involved in the reactions. Presence of grains strongly affect the abundances of the gas phase species. We also carry out a comparative study between different pathways available for the synthesis of adenine, alanine, glycine and other molecules considered in our network.Comment: 12 pages, 4 figure