Reaction of hydroxycoumarins and its analogues

148-151<span style="font-size:14.0pt;mso-bidi-font-size:9.0pt; font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">4-Hydroxycoumarins, thiocoumarins, 4-hydroxy-2-quinolones when condensed with ethyl 2,3-dihydro-3-oxo-benzofuran-2-carboxylate afford the corresponding 6H, 12H-benzofuro[2',3' ;4,5]pyrano[3,2-c]benzopyran-6, 12-diones 3a-e, 6H, 12H-benzofuro[2',3' ;4,5]pyrano[3 <span style="font-size:13.5pt;mso-bidi-font-size:8.5pt; font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">,2-c]thiobenzopyran-6, 12-dione <b style="mso-bidi-font-weight: normal">3f, <span style="font-size:13.5pt;mso-bidi-font-size:8.5pt; font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa;="" mso-bidi-font-style:italic"="">6H, <span style="font-size:14.0pt; mso-bidi-font-size:9.0pt;font-family:" times="" new="" roman";mso-fareast-font-family:="" "times="" roman";mso-ansi-language:en-us;mso-fareast-language:en-us;="" mso-bidi-language:ar-sa"="">12H-benzofuropyrano[3,2-c]quinoline-6, 12- diones 4a-k respectively. 6-Ethyl-7-hydroxy-4-methylcoumarin on condensation with ethyl 2,3-dihydro-3-oxo-benzofuran- 2-carboxylate yields 2<i style="mso-bidi-font-style: normal">H,8H-benzofuro[2',3';3,4]-pyrano[2,3-h] benzopyran-2,8-dione 5.</span

Vibration of non-uniform thin-walled beams of arbitrary shape

A generalised theory for the natural vibration of non-uniform thin-walled beams of arbitrary cross-sectional geometry is proposed. The governing equations are obtained as four partial, linear integro-differential equations. The corresponding boundary conditions are also obtained in an integro-differential form. The formulation takes into account the effect of longitudinal inertia and shear flexibility. A method of solution is presented. Some numerical illustrations and an exact solution are included

SOCIO-CULTURAL CONTEXT, ADDRESS FORMS AND COMMUNICATIVE STYLES (A CASE STUDY OF BRITISH AND INDIAN ENGLISHES)

The purpose of this study is to identify differences in the use of Address Forms for an unfamiliar addressee in British and Indian English and explain them through a sociocultural context. Given the fact that address forms are dependent on both situational and geographical parameters, and taking into account the rich cultural diversity of India, the study is limited to address forms used by residents of the two capital cities – London and Delhi. The material was collected through observations and questionnaires and was analysed with a comparative analysis (both quantitative and qualitative) and reference to the theory of cultural differences, intercultural pragmatics, politeness theory and the theory of culturally specific communication styles or communicative ethnic styles. For clarification of the results, the interview method was also used, attempting to establish the regularity with which the representatives of the given cultures use nominative address forms for an unfamiliar addressee, the choice of address forms for different age groups and gender and the sociocultural factors affecting the choice of address forms. The analysis of experimental data shows significant differences both in the choice of address forms and in their functioning, it convincingly demonstrates the influence of the Hindi language and local culture on the Indian version of the English language, on the communicative behaviour of Indian bilinguals in the given situation and their communication style in general