Ayurveda classifies the whole human population in three major constitutions as Vata, Pitta, Kapha and their possible combinations. Their homologous relation to human genetic structure needs to be studied for validation. If validated, our hypothesis would have far reaching implications for pharmacogenomics, modern genetics, human health, and Ayurveda.
Association of HLA and diseases is well known. Several population studies are available suggesting evidence of association of HLAs in more than 40 diseases. HLA found across various populations vary widely. Some of the reasons attributed for such variation are occurrence of social stratification based on geography, language and religion, consequences of founder effect, racial admixture or selection pressure due to environmental factors. Hence certain HLA alleles that are predominantly associated with disease susceptibility or resistance in one population may or may not show any association in other populations for the same disease. Despite of these limitations, HLA associations are widely studied across the populations worldwide and are found to be important in prediction of disease susceptibility, resistance and of evolutionary maintenance of genetic diversity. This review consolidates the HLA data on some prominent autoimmune and infectious diseases among various ethnic groups and attempts to pinpoint differences in Indian and other population.
The increasing demand for plastics for their widespread applications has ultimately resulted in accumulation of substantial plastic waste, which remains a concern due to limited efforts, inadequacy, and environmental distresses of conventional techniques for waste plastics remediation. The enhanced production of raw materials for polymer syntheses has a dual impact on our ecosystem by causing rapid depletion of nonrenewable petroleum resources and waste generation. To address this situation, researchers have adopted advanced thermochemical recycling processes to produce intermediate products of the petrochemical industries including monomers, fuels, and other value-added products. Such practices can potentially serve the purpose of a circular economy. This review aims to cover the recent highlights in the field of waste plastics pyrolysis including critical observations from the past to provide precise understanding. Consequently, the reactivities and product distributions for plastic feeds, pyrolysis reactors, roles of catalysts, and effects of operating parameters on reactivity and selectivity have been covered. Coprocessing of plastic waste with radioactive materials, biomass, and heavy petroleum residue is also discussed. Furthermore, an overview on kinetics and mechanistic aspects of plastic pyrolysis is presented with a discussion on relevant analytical techniques. The applications of pyrolysis oil as a fuel or fuel additive are comprised in a separate section. Lastly, comparisons of existing chemical recycling technologies, summaries of commercial operations, and future projections are provided.
In this paper, a quick and direct method has been developed for the quantitative estimation of
total aromatics and saturates in a vacuum gas oil (VGO) fractions boiling range (370−560 °C),
using 1H NMR spectroscopic techniques. The method is based on the estimation of the average
alkyl chain length of substituents on aromatics and the relative group molecular weight of
aromatics and saturates. The total aromatics are estimated from the derived equation, which
takes into account the relative distribution of CH
n
(n = 0, 1, 2, 3) groups of aromatics substituents
and saturates. The exact assignment of aromatics substituents of α-CH
n
(n = 1, 2, 3) has been
performed by the application of 1H/13C multipulse NMR techniques, such as DEPT-135 and 2D
HSQC (edited) (heteronuclear single quantum coherence). The results obtained for several VGO
samples from different sources have been in close agreement with those from the open
chromatography method (ASTM D-2549-91) and the thin-layer chromatography−flame ionization
detection (TLC−FID) method (IP-469).
A dynamic 1H NMR-based method for the estimation of olefin content in
all cracked fuel range products, in general, and in gasoline/naphtha
streams, in particular, irrespective of types and composition of olefins
and boiling range of samples has been developed. This is in continuation
of our earlier works where two methods were described for the determination
of hydrocarbon types in straight-run gasoline (no olefins) and cracked
full range gasoline/naphtha (with olefins). The average absolute number
of unsaturated hydrogen (H) in the olefinic region
(4.4–6.5 ppm) was directly estimated with the help of a 1H NMR spectrum using dynamic variables in terms of differential
population of various kinds of olefins. The average alkyl chain length
(n) was estimated by various methods including 13C NMR and carbon number distribution by a gas chromatography-based
detailed hydrocarbon analyzer [DHA, ASTM D6730-01(2016)] and simulated
distillation [ASTM D2887-16a]
data. The percentage of unsaturated hydrogen (% UH) in an average
olefin was then obtained providing a multiplication factor (f
o) by which the weight percentage of olefin
is estimated using a normalized 1H NMR spectrum. The dynamic
estimation of H and n for each sample
removes the possibilities of errors in the estimation. The method
has efficiently been extended to coker kero and coker diesel range
products where there has been no method available for olefin estimation.
The method was validated by using DHA following ASTM D6730, by the
Reformulyzer-based ASTM D6839 method, and finally by fluorescent indicator
adsorption following ASTM D1319. All the methods were compared. Whereas
the proposed NMR method is extremely general, free from manual error,
the limitations of existing ASTM methods and the old NMR method vis
á vis a new NMR method are also discussed.
Although the concentration of nitrogen compounds in crude oil is relatively low, they can become more concentrated in petroleum distillates and poison the catalysts used in refining processes. They cause undesirable deposits, color formation and odor in products; they also contribute to air pollution and some are highly carcinogenic. The poisoned catalyst becomes deactivated for hydrodesulfurization and unable to remove sulfur from middle distillates. In order to understand the effect on catalytic processes, it is desirable to identify the nitrogen compounds in various petroleum distillates. This paper compares the nitrogen species profiles in different petroleum distillates using a nitrogen chemiluminescence detector. In addition, four different petroleum distillate samples from different refineries were analyzed to find the variation in their nitrogen profiles. The nitrogen compounds in petroleum distillate samples were identified as anilines, quinolines, indoles, and carbazoles and their alkyl derivatives. Quantitation was carried out against known reference standards. The quantitative data were compared to the total nitrogen content determined by elemental analysis.
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