1,183 research outputs found
Taxonomic significance of leaf epidermal anatomy of selected Persicaria Mill. species of family Polygonaceae from Pakistan
Leaf epidermal anatomy of selected Persicaria Mill. species of the family Polygonaceae revealed variation in size and shape of epidermal cells, stomata, glandular and non glandular trichomes. This study proves to be taxonomically important tool in the delimitation of taxa. Epidermal cell shapes are variable but mostly polygonal. Five different stomatal patterns are reported for Persicaria Mill. Two types of non glandular trichomes are observed only in P. barbata, P. stagnina and P. orientalis which serve as their distinguishing characters. Glandular trichomes are 1, 2 and 4-celled peltate, capitate and spheroidal. Cluster analyses elucidate relationship among different taxa by utilization of leaf epidermal characters
Determination of pesticide residues in blood samples of villagers involved in pesticide application at District Vehari (Punjab), Pakistan
Blood samples were collected from field workers involved in pesticide spraying activities at three different farms in Tahsil Mailsi, District Vehari (Punjab), Pakistan. Twenty seven villagers (including three controls), ranging from 16 to 50 years of age and one to nine years of pesticide application experience were tested. The blood samples were analyzed for 383 different pesticides using Gas Chromatograph Mass Spectrometer (GC-MS) multi residue analytical technique. Only chlorpyrifos (0.009 mg/l) and pyributicarb (0.001 mg/l) were detected in the blood samples.Key words: Multi-pesticide residues, blood sample, GC-MS
Nonlinear Modeling and Analysis of Pressure Wave inside CEUP Fuel Pipeline
Operating conditions dependent large pressure variations are one of the working characteristics of combination electronic unit pump (CEUP) fuel injection system for diesel engines. We propose a precise and accurate nonlinear numerical model of pressure inside HP fuel pipeline of CEUP using wave equation (WE) including both viscous and frequency dependent frictions. We have proved that developed hyperbolic approximation gives more realistic description of pressure wave as compared to classical viscous damped wave equation. Frictional effects of various frequencies on pressure wave have been averaged out across valid frequencies to represent the combined effect of all frequencies on pressure wave. Dynamic variations of key fuel properties including density, acoustic wave speed, and bulk modulus with varying pressures have also been incorporated. Based on developed model we present analysis on effect of fuel pipeline length on pressure wave propagation and variation of key fuel properties with both conventional diesel and alternate fuel rapeseed methyl ester (RME) for CEUP pipeline
Phylogenetic analysis of Artemisia L. (Asteraceae) based on micromorphological traits of pollen grains
The phylogenetic relationships within the genus Artemisia have been very controversial. In order to recognize the systematic inference of pollen grains in this genus, the micromorphological characteristics of pollens from 22 taxa were examined by means of light microscopy (LM) and scanningelectron microscopy (SEM). A phylogenetic analysis of Artemisia based on 9 micromorphological characters of pollens was conducted using Wagner parsimony method. In the resulting phylogenetic tree, relationships among different Artemisia species are shown. This study also presents thephylogenetic associations among 4 sections within the genus Artemisia. The reunion of genus Seriphidum with Artemisia was also confirmed
Phylogeny of Artemisia L.: Recent developments
In this review, classification and phylogeny of genus Artemisia L. is discussed. Its centers of diversity lie in the temperate and cold temperate regions of the Eurasia, North America and Asia. Artemisia has two basic chromosome numbers, with ploidy levels x=9 and x=8. Chromosome number in diploid is most often 2n=18 or 16. The genus is divided into five large groups Absinthium DC., Artemisia L., Dracunculus Besser, Seriphidium Besser and Tridantatae (Rydb.) McArthur. Its phylogeny was based on the two hypothesized evolutionary trends, loss of fertility in the disc florets and loss of ray florets. Recently its molecular phylogeny based on internally transcribed spacer (ITS), externally transcribed spacer (ETS) regions of the DNA and chloroplast DNA suggested that the genus Artemisia is a monophyletic but it could not resolve the problem of infra-generic classification. This study revealed that there is need to search new genome regions to establish a natural classification based on modern molecular techniques
Linear Optical Quantum Computing in a Single Spatial Mode
We present a scheme for linear optical quantum computing using time-bin
encoded qubits in a single spatial mode. We show methods for single-qubit
operations and heralded controlled phase (CPhase) gates, providing a sufficient
set of operations for universal quantum computing with the
Knill-Laflamme-Milburn scheme. Our scheme is suited to available photonic
devices and ideally allows arbitrary numbers of qubits to be encoded in the
same spatial mode, demonstrating the potential for time-frequency modes to
dramatically increase the quantum information capacity of fixed spatial
resources. As a test of our scheme, we demonstrate the first entirely single
spatial mode implementation of a two-qubit quantum gate and show its operation
with an average fidelity of 0.84+-0.07.Comment: 5 pages, 4 figures. Updated to be consistent with the published
versio
Foliar epidermal anatomy and its systematic implication within the genus Sida L. (malvaceae)
Micro morphological investigations of the foliar epidermal anatomy, particularly the diversity and distribution of glandular and eglandular trichomes on leaves of Sida alba L., S. alii S. Abedin var. alii, S.cordata (Burm. F.) Brss, S. mysorensis Wight and Arn, S. ovata Forssk. S. spinosa L and S.yunnanensis S.Y.Hu have been carried out to assess the systematic relevance of epidermal features and trichome diversity within the genus Sida L. Configuration of epidermal cells is polygonal to irregular with smooth or undulating outline. Leaves are amphistomatic and amphitrichomic. Six diverse morphological types of glandular and eglandular foliar trichomes are described. Stellate and peltate types of trichomes are characteristically found in all taxa studied. S. alii and S.spinosa are distinct in having long-stalked and short-stalked capitate trichomes. S. mysorensis is characterized by multicellular uniseriate trichomes, but these are not observed in other taxa of genus Sida. The results of foliar epidermal anatomy, especially type, distribution and structure of foliar trichomes are of high systematic value in this genus of family Malvaceae
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Preparation and thermophysical characterisation analysis of potential nano-phase transition materials for thermal energy storage applications
Data availability: Data will be made available on request.Copyright © 2023 The Author(s). . The efficacious use of phase change materials (PCMs) is mainly confined by their poor thermal conductivity (TC). In this study, multiwalled carbon nanotubes (MWCNTs), graphene nanoplatelets (GNP) and titanium oxide (TiO2) based single, and novel hybrid nano additives were incorporated into paraffin, a typical PCM, to find the optimal composite which could not only enhance the thermal conductivity but also limit the latent heat. Both unitary and hybrid nanoparticles at five different concentrations (0.2, 0.4, 0.6, 0.8 & 1.0 wt%) were investigated using various characterisation techniques, including FT-IR, XRD, DSC, TGA, and TC apparatus. The results depicted good intermolecular interactions between the PCM and the nanoparticles and showed that the dispersion of nanoparticles within the PCM did not affect the chemical structure of pristine paraffin but enhanced its thermal and chemical stability. Novel hybrid nanocomposites were found to be more stable and exhibit better thermal performance than single nanocomposites. The highest value of thermal conductivity was observed at 1.0 wt% of GNP + MWCNTs hybrid particles based PCM with a maximum enhancement of 170% at 25 °C. However, compared with single and hybrid carbon-based nanofillers, TiO2 based mono and hybrid nano-PCM showed a minimum reduction in the latent heat with a maximum decrease of −3.7%, −5.2%, and −5.5% at 1 wt% of TiO2, TiO2 + GNP and TiO2 + MWCNTs, respectively. The significant improvement in the thermal properties of PCMs with the inclusion of these nanofillers indicates that they have the potential to be employed in thermal energy storage applications.European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 801604; Royal Society (RGS\R2\222256 and IES\R3\183069)
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Enhancing thermal energy storage in buildings with novel functionalised MWCNTs-enhanced phase change materials: Towards efficient and stable solutions
Data availability: Data will be made available on request.Copyright © 2023 The Author(s). Phase change materials (PCMs) are a promising panacea to tackle the intermittency of renewable energy sources, but their thermal performance is limited by low thermal conductivity (TC). This pioneering work investigates the potential of organic PCM-enriched surface-modified and un-modified multi-walled carbon nanotubes (MWCNTs) for low-temperature thermal energy storage (TES) applications. The functionalised and un-functionalised MWCNTs enhanced PCM have demonstrated a TC enhancement of 158 % and 147 %, respectively, at 25 °C. However, the TC value of the unmodified MWCNTs-based PCM dropped by 52.5 % after 48 h at 25 °C, while that of the functionalised MWCNTs-based PCM remained stable. A DSC analysis of up to 200 thermal cycles confirmed that the surface-modified and un-modified MWCNTs had no major effect on the peak melting and cooling temperatures of the nano-enhanced PCMs although a minor decrease of 7.5 % and 7.7 % in the melting and crystallisation enthalpies, respectively, was noticed with the inclusion of functionalised MWCNTs. Moreover, functionalised MWCNTs incorporated PCMs have led to increases in specific heat capacity by 23 % with an optimal melting enthalpy value of 229.7 J/g. In addition, no super-cooling, no phase segregation, and a small phase change temperature were noticed with these nano-enhanced PCMs. Finally, no chemical interaction from nano-PCMs was seen in the FT-IR spectra with the incorporation of both functionalised and un-treated MWCNTs. It is evident that the functionalised MWCNT-based PCM has better thermal stability and it offers a promising alternative for improving thermal storage and management capabilities in buildings, contributing to a sustainable and energy-efficient building design.European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 801604
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