Microscopic characterization of petiole anatomy of Asteraceous taxa of Western Himalaya-Pakistan

Petiole anatomy of 15 species of family Asteraceae was examined which aimed to investigate petiolar anatomical structures for species level identification. Shandon Microtome was used for petiole histological preparations. Both qualitative and quantitative features were studied under microscope which showed significant variation in petiole, collenchyma, parenchyma shape/size, vascular bundles arrangement/size, and vessel elements quantity. Artemisia japonica Thunb., Cirsium vulgare (Savi) Ten., Myriactis nepalensis Less., Seriphidium brevifolium Ling & Y.R.Ling, Taraxacum officinale (L.) Weber ex F.H.Wigg., and Xanthium strumarium L. showed winged petioles. Maximum length and width of upper and lower epidermis was found in Tagetes erecta L. which is 23.05 ± 0.89 μm, 24.9 ± 1.257 μm length and 21.75 ± 1.38067 μm, 22.75 ± 0.467 μm width, respectively. Petioles of Parthenium hysterophorus L. was longest one with 9.85 ± 10.45 μm while A. japonica Thunb. showed highest number of vessel elements. Maximum size of vascular bundles was found in T. erecta L. with 5.05 ± 14.25 μm. Artemisia annua L., C. vulgare (Savi) Ten, Cyanthillium cinereum (L.) H.Rob., Helianthus annus L., M. nepalensis Less., P. hysterophorus L., Senecio chrysanthemoides DC. have trichomes while Tussilago farfara L. has highest number of vascular bundles. All species have angular collenchyma type except M. nepalensis Less., P. hysterophorus L., S. brevifolium Ling & Y.R.Ling, Tagetes minuta L., T. officinale L., S. chrysanthemoides DC., and T. farfara L. Cluster analysis implemented that distinct plant species in cluster. Petiolar anatomical structures and taxonomic key will helpful for distinguishing Asteraceous taxa at genus and species level. This taxonomic significant investigation will also provide baseline to taxonomists for other Asteraceae studies and phylogenetic research.     

Identification of novel,non-edible oil seeds via scanning electron microscopy as potential feedstock for green synthesis of biodiesel

In the present era, environmental glitches associated with extensive emission of greenhouse gases (GHG) and energy crises caused by exhausting fossil fuel reservoirs has diverted researcher's interest toward alternative and renewable energy sources. Biodiesel is a renewable, biodegradable, and sustainable alternative to petro-diesel. Biodiesel synthesized from non-edible seed oils is preferred due its cost effectiveness and eco-friendly nature. Hence, our present study focused on investigation and identification of micromorphological characters of six novel, non-edible seed oil feedstock for biodiesel production via scanning electron microscopy (SEM). Results of light microscopy of seeds revealed distinct variation in seed size (15.8–1.8 mm in length and 9.4–1.1 in width), shape (round to Cuneiform), and color (from black to yellowish green). Non-edible seed oil content fall in range of 28–38% (wt/wt). Free fatty acid (FFA) content varied from 0.56 to 2.06 mg KOH/g. Multivariate analysis was performed to investigate correlation between three significant variables of seed oil yielding feedstock such as potential for biodiesel synthesis, oil content, and FFA content via principal component analysis. Ultra morphological investigation of seeds surfaces via SEM exhibited distinctive variation in surface sculpturing, cell arrangement, cell shape, periclinal wall shape, margins, protuberances, and anticlinal wall shape. Seed surface sculpturing varied from reticulate, semitectate, wrinkled, rugose, papillate, perforate, and striate. Periclinal wall arrangements confirmed variation from glabrous, raised, depressed, elevated, smooth, pentagonal, entire, and ripple margins. Whereas, anticlinal walls pattern demonstrated variation from angular, smooth, wavy, deep, dentate, entire, irregular, puzzled, elongated, curved, and depressed. Finally, it was concluded from obtained results that SEM could be a possible useful tool in disclosing veiled micromorphological characters of non-edible oil yielding seeds, which provides useful information to researchers for their correct, authentic identification, and classification in modern synthetic system.     

Effect of Acid–Base Properties on the Catalytic Activity of Pt/Al2O3 Based Catalysts for Diesel NO Oxidation

The activity of Pt catalysts supported on Al₂O₃ modified with various acid–base additives has been investigated for oxidation of NO to NO₂. Although Pt dispersion was changed by the additives, there was no clear effect of Pt dispersion on the catalytic activity. The measurement of solid acid–base properties of the modified Pt/Al₂O₃ indicated that the NO oxidation activity increased by the increase of surface density of strong acid sites and decreased by the increase of basic sites. It was suggested that platinum on the acidic supports keeps its highly active metallic state for NO oxidation, while the formation of nitrate/nitrite on the basic supports inhibits the reaction on the Pt surface.     

Enhanced NOx Conversion with Decane Over Ag/Al2O3 and Metal Supported ZSM-5 Composite SCR Catalysts

A combination of Ag/Al₂O₃ and a partial oxidation catalyst M/ZSM-5, M being different metal cations, were evaluated for selective catalytic reduction of NO with decane. Physical mixture of Ag/Al₂O₃ and M/ZSM-5 catalysts showed significant increase in NOx conversion compared to single component Ag/Al₂O₃ catalyst. M/ZSM-5 as a second catalyst component was found to generate more reactive hydrocarbons, such as unsaturated small chain hydrocarbons and oxygenates in situ, and enhance the NOx conversion over Ag/Al₂O₃ HC-SCR catalyst.     

Study of Antibacterial Activity of Metal Nanoparticle Absorbed Fly‐Ash based Ceramics

The bactericidal action of silver nanoparticles has been observed by many researchers since few years. In this study, we have developed an antibacterial ceramics (ACs) by absorbing synthesized silver nanoparticles within the ceramic matrix developed by us from an abundantly available coal fly ash, an extremely hazardous by‐product of thermal power plants. Nanoparticles dispersions of different particle sizes were made absorbed in to the ceramic matrix to evaluate its bactericidal activity against both Staphylococcus aureus (Gram‐positive) and Escherichia coli (Gram‐negative) bacteria, taken as the model microorganisms. This study showed that the total bactericidal action of ACs depends on the size of absorbed nanoparticles and the content of nanoparticles in the dispersions within the ceramic matrix. ACs thus developed release very slowly a minute amount of nanoparticles and show strong and prolonged bactericidal activity against pathogenic strain of both types of bacteria. The concentration of prepared nanoparticles in dispersion and the concentration of released nanoparticles in aqueous medium from the absorbed ceramic matrix were measured using inductively coupled plasma spectrophotometer. The mechanism of the antibacterial action was also studied using transmission electron microscopy image analysis of the bacterial cross‐section of both types of bacteria.     

Intraspecific variation in spermoderm pattern of tribe Acacieae (Mimosoideae) using scanning electron microscopy techniques

Current research carried out in Pakistan is the first report on spermoderm ornamentation of eight species of tribe Acacieae (Mimosoidae) by using scanning electron microscopic techniques representing two genera, Fedherbia and Acacia were examined. Different spermoderm ornamentation were observed, described and discussed for their taxonomic importance. Seeds surfaces of the studied tribe possess novel variations in macro and micro morphology. Great variations were observed in both qualitative and quantitative characters of seeds. Seeds shape was oblong, ovate to elliptical and spermoderm ornamentation was levigate, rugose, polygonal and discoid, colliculate, and papillose type. These variations in the spermoderm ornamentation can be used as an aid in identification and classification of the members of tribe Acacieae.     

Toffoli Netlist and QCA implementations for existing four variable reversible gates: a comparative analysis

Microsystem Technologies - With CMOS reaching its fundamental physical heat threshold limits, reversible logic has emerged as a viable alternative due to its heat arresting attributes. CMOS started...