Pakistan is blessed with hundereds of species of medicinal plants, however a very small fraction of these plants has been evaluated so far for their curative potentials. In Pakistan, most of the people trust on herbal medicines due to common belief of safety and economical reasons. Therefore, there is a need of systematic and well organized study of these plants to explore their therapeutic potential. Research described in this thesis is an effort to find new plants that could provide new principle leads to solve health issues of people by local sources. The present Ph. D. thesis deals with the, “Chemical and Biological Investigation on the Secondary Metabolites of Pakistani Medicinal Plants; E h r e t i a A c u m in a t a and Atriplex Lasiantha”. The whole dissertation has been divided into five chapters. Chapter 1 offers a comprehensive overview of role of natural products in human health and also provides a mini review of important bioactive secondary metabolites and drugs derived from different natural sources. In Chapter 2 a brief phytochemical survey of various species of the genus Atriplex has been incorporated. Chapter 3 covers detailed structure elucidation of the isolated compounds isolated from Atriplex lasiantha, evaluation of their biological activity, experimental procedures and spectroscopic data. The methanolic extract of Atriplex lasianta showed Summary ii anti-bacterial, anti-oxidant and enzyme inhibitory properties, therefore, the extract was partitioned into n- hexane, ethylacetate and water fractions. The ethyle acetate fraction was subjected to chromatographic purification. This fraction afforded 15 compounds out of which atrioleanoside (152) has been isolated for the first time from any natural source, whereas, others were decalred as from new source. The compounds isolated in sufficient quantity were tested for Anti-bacterial, Anti-oxidant and anti-urease activity. Among the tested compound, 152- 155 and 161 showed good results.Chapter 4 includes the literature survey of phytochemicals isolated from different species of the genus Ehretia. Chapter 5 describes detailed structure elucidation of the compounds isolated from Ehretia acuminata, evaluation of their biological activity, experimental procedures and spectroscopic data. The methanolic extract of Ehretia acuminata showed anti-bacterial, anti-oxidant and enzyme inhibitory properties, therefore, the extract was partitioned between n-hexane, ethylacetate and water fractions. n-Hexane fraction was subjected to chromatography to get three compounds 174, 235 and 236. Similarly ethyl acetate fraction was treated in the same fashion and afforded 10 compounds 171, 194, 227- 234. Overall 13 compounds were isolated from Ehretia acuminate. All these compounds are already reported from different natural sources; however these are isolated for the first time from Ehretia acuminata. The compounds isolated in sufficient quantity were tested for antibacterial, anti-oxidant and anti-urease activity. Compound 171, 174, 192, 227, 232, 234 and 236 showed good results for anti-oxidant activity and anti-bacterial activity but were inactive in anti-urease assay.
Religion is considered as an integral part of individuals’ daily routine practices in the society. People perform religious obligations very rigorously and avoid all the religiously declared prohibited acts. This current study aims, to identify the role of group conformity towards adopting sectarian identities by individuals with the emphasis of exploring the practices of sectarian identities that causes an environment of inter-group disintegration in the community. This study will be significant in recommending initiatives that can create an environment of harmony between people belonging to different sectarian believers. Qualitative research method was applied to analyze group conformity and individuals’ behavior towards practicing sectarian identities. Population was based on rural setup of Manddi Faiẓ Abad. Twelve participants were selected through purposive sampling technique. Structured interview guide was used as data collection tool and themes was extracted to describe existing trends and patterns regarding group conformity and sectarian identity construction. Results revealed efficacious role of group conformity to encourage individuals towards adopting and practicing any particular sectarian identity in the society. Results highlighted that, desire of getting religious hegemony and supremacy with the courtesy of group conformity that make individuals intolerant on sectarian grounds and creates an environment of disintegration in the society. Sectarian difference not only creates religious
Miniature Neutron Source Reactor (MNSR) is a passively cooled system operating in Natural convection heat transfer mode. A typical MNSR located at the premises of PIEAS (Pakistan Institute of Engineering and Applied Sciences) called as Pakistan Atomic Research Reactor-II, PARR-II. From safety analysis point of view the literature lacks any experimental study or information that can be used to predict the outer surface temperatures along the axial length of a fuel rod in the reactor core. Similarly the literature also lacks any information regarding the prediction of the fluid exit bulk temperature as a function of the reactor thermal power. The thermal power range for the operation of this particular MNSR studied ranges from 5.4 to 27 KW. The current experimental study is a pioneering effort to find a solution to the above mentioned problem. Hence, steady state heat transfer by natural convection was investigated experimentally from an enclosed assembly of thin vertical cylinders at high Grashof numbers. The published literature lacks experimental data regarding such a study in the turbulent boundary layer regime. An enclosed assembly consisted of a 3 x 3 array of vertical cylinders immersed in a large volume tank of water was used. All the cylinders were electrically heated. Various uniform heat fluxes were applied to each cylinder and the surface temperature at different positions along the cylinders were measured. The experimental results show that the surface temperature increases axially up to a certain length, then decreases due to some extra mixing which increases the heat transfer. However, such a behavior is expected to have little effect if the enclosed assembly consists of a large number of thin vertical cylinders. A criterion has been proposed for the determination of the onset of turbulent boundary layer in an assembly. The local heat transfer coefficient, local Nusselt number and local modified Rayleigh number have been presented for the experimental data. It has been found that a much better representation of experimental data results, if the Nusselt number is presented as a function of modified Grashof number and Prandtl number separately instead of modified Rayleigh number. This representation includes the effect of different fluids and L/d ratios. Similarly empirical correlations between overall Nusselt number and average modified Rayleigh number have also been developed based on the data of the assembly of cylinders used in the current study. This empirical correlation for an assembly * developed in current study is valid for 1.28 x 10 12 £ RaL £ 1.18 x 1013. A much better generalized correlation has also been proposed for natural convection heat transfer from a single vertical cylinder in an infinite medium which shows a better fit to all the currently available experimental data. The literature also lacks such a generalized correlation. The results obtained in this study have been utilized to predict the axial surface temperatures as well as the fluid bulk outlet temperature of PARR-II. Hence the correlations developed from current study are applicable to all thermal power ranges in PARR-II type MNSR reactors or any other assembly of vertical heated thin cylinders.