Scanning electron microscopy as a tool for authentication of biodiesel synthesis from Linum usitatissimum seed oil

Utilization of renewable and alternative energy feedstocks such as nonedible seeds oil to deal with the increasing energy crises and related ecological concerns have gained the attention of researchers. Biodiesel is an efficient and renewable substitute for diesel engine. This work investigates the potential of inexpensive nonedible seed oil of Linum usitatissimum to synthesize biodiesel using iron sulfate green nanocatalyst through the process of transesterification. Flax seed contains about 37.5% oil content estimated through Soxhlet apparatus. Light microscopy revealed that seed size varies from 3.0 to 6.0 cm in length, 2.0 to 3.3 cm in width, and 0.7 to 1.0 mm in diameter. Color of seed varied from yellow to brown. Characterization of biodiesel is performed through GC–MS and FTIR. Scanning electron microscopy was carried out to study the morphological features of seed coat. Catalyst was characterized by scanning electron microscopy, energy diffraction X-ray, and X-ray diffraction. The diffraction peaks of Fe₃O₄ green nanoparticles were found to be in 2θ values, 30.24°, 35.62°, 38.26°, 49.56°, 57.12°, and 62.78°. Fuel properties of biodiesel are also determined and compared with ASTM standards. Linum usitatissimum biodiesel has density 0.8722 (15°C kg/L), kinetic viscosity 5.45 (40°C cSt), flash point (90°C), pour point (−13°C), cloud point (−9°C), sulfur (0.0432% wt), and total acid number (0.245 mg KOH/g). It is concluded that L. usitatissimum seed oil is a highly potential source for biodiesel production to cope with the challenge of present energy demand.     

Scanning electron microscopy leads to identification of novel nonedible oil seeds as energy crops

Currently, exploration of alternative energy resources is hotly debated among the scientific community owing to rising energy crises and environmental issues. Biodiesel, as renewable energy source proves to be a better option and substitute to petro diesel. In this regard, nonedible seeds could be a better feedstock for synthesizing biodiesel due to their cost effectiveness and environmental friendly attributes. The present study, therefore, deals with the exploration and identification of micromorphologic features among eight novel nonedible oil yielding seeds via scanning electron microscopy (SEM) as potential feedstock for biodiesel industry. Light microscopic studies revealed that seeds size vary from 0.1–2.9 cm in length to 0.1–3 cm in width. Moreover, a great variation in seed color from black, green, and different shades of brown was also observed. Seeds ultra‐structure examination by SEM exhibit great variation in seed shape, size, color, sculpturing and periclinal wall shape and arrangement and so on. All the understudy seeds vary from rounded, irregular, subspherical, ellipsoidal, reniform, flattened, polygonal, ovate, pyriform, oblong, and globose shape. Seeds wall structure exhibits great variation from entire, angular, straight, irregular, polygonal, smooth, and elongated. The periclinal wall pattern exhibits variation from flat to slightly concave‐convex with straight, angular, undulate, or dentate seeds margin. Among the studied species only Argemone ochroleuca Linn. (Papaveraceae) possess micropylar peak, ridged raphe, and basal helium. The obtained results from the present study would therefore, suggest that SEM could be a useful tool in refreshing the veiled micromorphological features among different oil yielding seeds which in turn helps the researchers for their correct identification, exploration, authentication, and seeds classification in future.     

Implication of scanning electron microscopy as a tool for identification of novel,nonedible oil seeds for biodiesel production

Biodiesel is a promising, bio-based, renewable, nontoxic, environment friendly, and alternative fuel for petroleum derived fuels which helps to reduce dependency on conventional fossil fuels. In this study, six novel, nonedible seed oil producing feedstock were explored for their potential for sustainable production of biodiesel. It is very important to correctly identify oil yielding plant species. Scanning electron microscopy (SEM) was used as reliable tool for authentic identification of oil yielding seeds. Macromorphological characters of seeds were studied with light microscopy (LM). Outcomes of LM of seeds exposed distinctive variation in seed size from 16.3 to 3.2 mm in length and 12.4 to 0.9 mm in width, shape varied from oval to triangular, and color from black to light brown. Oil content of nonedible seed ranged from 25 to 30% (w/w). Free fatty acid content of seed oil varied from 0.32 to 2.5 mg KOH/g. Moreover, ultra structural study of seeds via SEM showed variation in surface sculpturing, cell arrangement, cell shape, periclinal wall shape, margins, protuberances, and anticlinal wall shape. Surface sculpturing varied from rugged, reticulate, varrucose, papillate, and striate. Periclinal wall arrangements confirmed variation from rough, wavy, raised, depressed, smooth, and elevated whereas, anticlinal walls pattern showed variation from profuse undulating, smooth, raised, grooved, deep, curved, and depressed. It was concluded that SEM could be a latent and advanced technique in unveiling hidden micromorphological characters of nonedible oil yielding seeds which delivers valuable information to researchers and indigenous people for precise and authentic identification and recognition.     

Identification of novel nonedible oil seeds via scanning electron microscopy for biodiesel production

Exploration of substitute energy feed‐stocks is the much‐debated topic in the scientific society due to increasing power crises and related ecological concerns. As a source of sustainable energy, biodiesel turns out to be the best alternative to petro fuels. In this context, nonedible oil‐producing seeds might be a potential source for biodiesel production owing to their environment‐friendly nature and cost‐effectiveness. The current study, consequently, deals with the investigation and identification of micro‐morphological characters between six novel nonedible oil‐bearing seeds employing scanning electron microscopy as possible biodiesel feed‐stocks. Light microscopic examinations show that seed size varies from 0.3 to 1.3 cm in width and 0.5 to 1.5 cm in. Additionally, a large difference in seed color ranges from dark brown, black, and various shades of light brown was also witnessed. The FFA content of the seeds ranges in 0.3–4.1 mg KOH/g, and the seed oil content fall in 30–65% (w/w) range. SEM‐mediated seed ultrastructure investigations displays greater variation in seed size, shape, color, periclinal wall shape, and sculpturing and so on. All the seeds differ from rounded, ovoid, ovate, oblong, flattened, and elliptical shape. Greater variation in seed wall structure has been seen from angular, entire, irregular, straight, elongated, smooth, and polygonal. The periclinal wall arrangements show alteration from flat, depressed, elevated, smooth, pentagonal, bullate, and coarse seed margins. The results obtained from the current study suggest that scanning electron microscopy could be a beneficial tool in vitalizing the hidden micromorphological characters among various nonedible oil producing seeds, which eventually helps in exploration, correct identification, seed classification, and authentication in future.     

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.     

Light microscopy and scanning electron microscopy: Implications for authentication of misidentified herbal drugs

Plant‐based drugs have reached remarkable acceptability as therapeutic remedy for various diseases due to the adverse effects of contemporary medicines. This increasing popularity of herbal drugs leads to a growing herbal market for the development of plant‐based drugs, nutraceuticals, pharmaceuticals and cosmeceuticals. Herbal drug adulteration is a complex problem which currently has undeniable consequences on health and nutrition. Ambiguities in nomenclature, misidentification and resemblance of colour and texture of the crude herbal drugs are the major causes of adulteration. Three different species commercially marketed under the same trade name Halion are Lepidium apetalum, Asparagus officinalis, and Lepidium didymum. The genuine source of Halion is Lepidium apetalum, which is authenticated by using basic and advanced taxonomic techniques. Morphology, anatomy and palynology of the misidentified sources were done using light and scanning electron microscopic techniques for authentication. This study may help to set microscopic techniques as a tool to achieve quality and standardization of the genuine source of the herbal drug. Phytochemical analysis and biological screening is needed for the further establishment of authenticity and quality of herbal drugs.     

Characterization of an oil-degrading Microcoleus consortium by means of confocal scanning microscopy, scanning electron microscopy and transmission electron microscopy

A consortium of microorganisms with the capacity to degrade crude oil has been characterized by means of confocal laser scanning microscopy (CLSM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The analysis using CLSM shows that Microcoleus chthonoplastes is the dominant organism in the consortium. This cyanobacterium forms long filaments that group together in bundles inside a mucopolysaccharide sheath. Scanning electron microscopy and transmission electron microscopy have allowed us to demonstrate that this cyanobacterium forms a consortium primarily with three morphotypes of the heterotrophic microorganisms found in the Microcoleus chthonoplastes sheath. The optimal growth of Microcoleus consortium was obtained in presence of light and crude oil, and under anaerobic conditions. When grown in agar plate, only one type of colony (green and filamentous) was observed.     

Scanning electron microscopy and transmission electron microscopy study of hot-deformed γ-TiAl-based alloy microstructure

The aim of this work was to assess the changes in the microstructure of hot‐deformed specimens made of alloys containing 46–50 at.% Al, 2 at.% Cr and 2 at.% Nb (and alloying additions such as carbon and boron) with the aid of scanning electron microscopy and transmission electron microscopy techniques. After homogenization and heat treatment performed in order to make diverse lamellae thickness, the specimens were compressed at 1000 °C. Transmission electron microscopy examinations of specimens after the compression test revealed the presence of heavily deformed areas with a high density of dislocation. Deformation twins were also observed. Dynamically recrystallized grains were revealed. For alloys no. 2 and no. 3, the recovery and recrystallization processes were more extensive than for alloy no. 1.     

Scanning electron microscopy studies of protein-functionalized atomic force microscopy cantilever tips

Protein-functionalized atomic force microscopy (AFM) tips have been used to investigate the interaction of individual ligand-receptor complexes. Herein we present results from scanning electron microscopy (SEM) studies of protein-functionalized AFM cantilever tips. The goals of this study were (1) to examine the surface morphology of protein-coated AFM tips and (2) to determine the stability of the coated tips. Based on SEM images, we found that bovine serum albumin (BSA) in solution spontaneously adsorbed onto the surface of silicon nitride cantilevers, forming a uniform protein layer over the surface. Additional protein layers deposited over the initial BSA-coated surface did not significantly alter the surface morphology. However, we found that avidin-functionalized tips were contaminated with debris after a series of force measurements with biotinylated agarose beads. The bound debris presumably originated from the transfer of material from the agarose bead. This observation is consistent with the observed deterioration of functional activity as measured in ligand-receptor binding force experiments.     

Scanning electron microscopy 1928–1965

This article gives an account of the origins of the scanning electron microscope (SEM) and traces its development up to 1965 when the first SEM was marketed by the Cambridge Instrument Company. The survey concentrates on the SEM, as distinct from the microanalytic electron probe instruments that were also being developed during this period.     

Scanning electron microscopy applied to seed-borne fungi examination

The aim of this study was to test the standard scanning electron microscopy (SEM) as a potential alternative to study seed-borne fungi in seeds, by two different conditions of blotter test and water restriction treatment. In the blotter test, seeds were subjected to conditions that enabled pathogen growth and expression, whereas the water restriction method consisted in preventing seed germination during the incubation period, resulting in the artificial inoculation of fungi. In the first condition, seeds of common bean (Phaseolus vulgaris L.), maize (Zea mays L.), and cotton (Gossypium hirsutum L.) were submitted to the standard blotter test and then prepared and observed with SEM. In the second condition, seeds of cotton (G. hirsutum), soybean (Glycine max L.), and common bean (P. vulgaris L.) were, respectively, inoculated with Colletotrichum gossypii var. cephalosporioides, Colletotrichum truncatum, and Colletotrichum lindemuthianum by the water restriction technique, followed by preparation and observation with SEM. The standard SEM methodology was adopted to prepare the specimens. Considering the seeds submitted to the blotter test, it was possible to identify Fusarium sp. on maize, C. gossypii var. cephalosporioides, and Fusarium oxysporum on cotton, Aspergillus flavus, Penicillium sp., Rhizopus sp., and Mucor sp. on common bean. Structures of C. gossypii var. cephalosporioides, C. truncatum, and C. lindemuthianum were observed in the surface of inoculated seeds. Microsc. Res. Tech., 2009. © 2009 Wiley-Liss, Inc.     

Scanning electron microscope design for quantitative multicontrast

Conceptual designs of scanning electron microscopes (SEMs) using a time-of-flight electron spectrometer are presented. The procedure for making quantitative measurements with such SEMs is shown to be much simpler and versatile than using conventional SEMs. SEMs which use an electron time-of-flight spectrometer are able to operate as multicontrast analytical probes, capable of simultaneously quantifying surface topography, voltage, and material type. In addition, it is demonstrated that these SEMs can be designed to have high spatial resolution, good signal-to-noise characteristics, and to be of compact table-top size.     

Scanning electron microscopy analysis of corrosion degradation on tinplate substrates

The degradation of electrolytic tinplate used in food containers was analysed and evaluated, using scanning electron microscopy and electrochemical measurements of microcorrosion and ion dissolution by atomic absorption to prevent food contamination caused by metal traces and to increase the durability of such tinplates.     

Scanning electron microscopic technique for imaging a diamond tool edge

A technique is described to measure the edge radius of diamond cutting tools using the scanning electron microscope (SEM). This method attempts to overcome two major limitations of the SEM in this application: low image contrast and lack of quantitative topographic information. A line of electron beam contamination, viewed at an angle, provides improved contrast for focusing and a means of obtaining the tool profile from the geometry.     

New system for secondary electron detection in variable-pressure scanning electron microscopy

A novel secondary electron detection system combining a two‐stage detector head and a differential pumping system is presented. The detector head consisted of a scintillation Everhart‐Thornley detector and a microsphere plate, separating it from the lower vacuum in the intermediate chamber (below 0.1 mbar). The system was arranged asymmetrically, which should contribute to a lower gas leakage through the plate and a longer life span of the plate. The system offered all the advantages of the scintillator detector in a wide range of gas pressures, from high vacuum to those of the order of 10 mbar, typical of high‐pressure scanning electron microscopy.     

The morphology of stigma of Asteraceae observed by scanning electron microscopy

The morphology of stigma has taxonomic values. To further explore the taxonomy of family Asteraceae, the morphological characteristics of stigma of 28 genera, 32 species, and two varieties in the family were observed using scanning electron microscopy. The results indicated that the stigma morphology of these Asteraceae plants could be divided into 10 types, of which eight are reported for the first time. The morphological characteristics of stigma support the close relationship between genera Aster and Erigeron and among genera Sonchus, Taraxacum, and Youngia. Our results enriched the stigma type diversity data and provided a morphological basis for the study of the phylogenetic evolution of Asteraceae.     

Identification of monocot flora using pollen features through scanning electron microscopy

Pollen used to track structural and functional evolution in plants as well as to investigate the problems relative to plant classification. Pollen characters including ornamentation, shape, apertural pattern, pollen symmetry, colpus length, width, and margins used to detect the similarities and dissimilarities between genera and also species of the same genus. In this study pollen features of 20 monocot species belonging to 15 genera of the Amaryllidaceae, Asparagaceae, Iridaceae, Ixioliriaceae, Liliaceae, and Xanthorrhoeaceae were studied using scanning electron microscopy (SEM) and light microscopy (LM). In this study two species that is Zephyranthes citrina and Tulbaghia violacea were reported for the first time from Pakistan. Pollen grains were visualized with LM. Non‐acetolyzed and acetolyzed pollen were examined using SEM. A taxonomic key was developed to highlight the variation in pollen features in order to make their systematic application for correct species identification.