WCM 2015 - World Congress on Microscopy: Instrumentation Techniques and Applications in Life Sciences and Material Sciences

"WCM 2015 Conference Papers "

Evaluation of Low Cost Electrodes for Electrochemical Degradation of Pharmaceuticals: A Case Study on Methylene Blue[ ]


The possibility of water contamination by pharmaceuticals has greatly increased due to the increased and widespread manufacture together with extensive use of these compounds. Humans and ecosystems undergo significant risk upon chronic exposure to these pharmaceuticals and cumulative build-up of these contaminants in the various environmental compartments. Moreover, conventional water treatment methods often cannot degrade these pharmaceuticals. Among different alternative treatment methods, electrochemical degradation (ED), which depends on the generated ions in aquatic medium, has already proved to be a promising and interesting technique for effective oxidation of various organic pollutants. However, choice of electrode material largely contributes to the effectiveness of ED. Consequently costly electrodes had been chosen in most studies significantly decreasing the affordability of the ED process for waste water treatment application. Accordingly the objective of the present work is to evaluate low cost material as electrodes in ED process for degrading pharmaceutical compounds. Iron, aluminum and conductive carbon are the low cost electrode materials examined in the study. Methylene blue (MB) is chosen as a model pharmaceutical. The effect of electrode materials with varying pollutant concentration, current density and concentration of conductivity modifier are thoroughly examined using common salt and alum as conductivity modifier to find out the optimum condition for decolorization of MB. The results showed that 95 percent decolorization of 100 mg/l MB can be achieved at 10 minutes in ED process with conductive carbon electrode using 5g/l common salt as conductivity modifier. The electrodes are characterized by gravimetric and microscopic analysis. Negligible loss of electrodes mass but change in surface composition of electrodes has been observed for ED process associated with significant mineralization of pharmaceuticals. The novelty is that the present work demonstrates an alternative decolorization (and mineralization) option using low cost electrode materials which can significantly enhance the affordability and acceptability of the ED process for degrading pharmaceutical pollutants.

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Soft-enCapsulation of the Elastovisco-Plastic Materials[ ]


Soft-encapsulation is a process in which tiny particles or droplets are surrounded by a coating to give small capsules of many useful properties. In general, it is used to enclose solids, liquids, or gases inside a micrometric wall made of hard or soft soluble film, in order to reduce dosing frequency and prevent the degradation of pharmaceuticals and other Elastovisco-plastic materials. The reasons for Soft-encapsulation are countless. It is mainly used to increase the stability and life of the product being encapsulated, facilitate the manipulation of the product and control its liberation in an adequate time and space. There are more than 2000 varieties of soft-encapsulation available around the world; however they are often classified into twelve basic categories. Out of these twelve, three main categories have been selected for the present research studies. These categories were selected on the basis of their common texture classifications; very-hard, hard, and soft as well as their moisture and fat contents. The properties are reported based upon studies using indentation experimentation involving loading-unloading, and stress relaxation. The conventional indentation hardness values ranged from hard to soft. The hardness is universally proportional to the moisture content.

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Field Emission Microscopy, Spectroscopy, Scanning Electron Microscopy and Field Emission Phenomena from Graphene-like Structures[ ]


The presented paper gives a general overview of studies of field emission from carbon nanoclusters. The special attention has been given to the study of emission processes in the strong and super strong electric fields from graphene-like structures. The direct experiments have confirmed the phenomena of the low threshold field emission and explosive emission from carbon nanoclusters. Experimental data exhibiting the peculiarities of the energy spectrum of the field emission electrons emitted by graphene-like structures are presented. The new emission phenomenon connected to the high current electron emission from carbon nanoclusters (flash emission) has been discovered and reported. The application of the field emission from carbon nanoclusters cathodes are exemplified by the series of the portable x-ray devices.

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Microwave irradiation synthesis of 3D flower-like hydroxyapatite[ ]


Microwave synthesis of Hydroxyapatite (HA) using three different calcium precursors and EDTA as organic modifier has been reported in this paper. Scanning electron microscopic and X-ray powder diffraction studies revealed the formation of self assembled 3D hierarchical flower-like HA with some influence of the precursor used.

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Application of Light Microscopy for Studying the Processes of Formation and Decomposition of Wood[ ]


For understanding the processes of wood formation or of any impact of mechanical/chemical treatments on mature wood it is important to evaluate the changes in wood structure. During the study of wood formation in PInus sylvestris L. and Larix sibirica Ltb. and the impact of acoustic waves on oak (Quercus robur L.) wood we used the light microscopy and such metachromatic dye as cresyl-violet. Annual wood ring formation was studied by some directions: 1. to estimate the distribution of the processes of cell wall production by cambium, the development of primary and secondary walls of early and latewood tracheids in the course the seasonal wood ring formation and the effect of external factors on morphological characteristics of tracheids; 2. to record the presence of starch granules as the index of carbon store or its expenditure in favorable and unfavorable external conditions during phloem development in pine and larch; 3. to study the biochemical changes in mono-, di- and polymeric compounds (carbohydrates, organic and phenolic acids, hemicelluloses, cellulose and lignin), included in biosynthesis and the formation of wall structure of tracheids during them development. Light microscopy was also used to check of cell wall development and lignification in pine (Pinus sylvestris L.) callus growing under different conditions of the cultivation to compare lignification in vivo and in vitro. The structure of oak (Quercus robur) wood from different habitats and its destruction under ultrasound was studied with light microscopy to estimate the influence of the site conditions on oak wood structure and the changes in that under ultrasound of various powers. The examples of light microscopy applying in these fields are given in the paper.

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The Total Energy Distribution of Field Emission Electrons from Graphene-like Structures[ ]


In our previous study it has been found that the half-width of the total energy distribution of the field emission electrons (TED), emitted from carbon nanoclusters, is significantly broadened as compared with that of metals. The value of the TED broadening increases with the growth of the electric field. It has been shown that the maximum of the energy distribution shifts with increasing electric field in the region of lower energies.

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Electrochemical sensing of environment chlorophenol using SnO2@graphene modified Glassy carbon electrode[ ]


We demonstrate a simple way to synthesize SnO2@graphene (SnO2@Gr) by simple heating of graphene oxide (GO) and SnCl2 precursor. The synthesized composite was thoroughly characterized by X-ray diffraction analysis (XRD) and Field emmision scanning electron microscopy (FE-SEM). these results clearls the spherical SnO2 particles are uniformly distributed on the graphene sheets through electrostatic adsorption. Further the SnO2@Gr modified Glassy carbon electrode (SnO2@Gr/GCE) was applied for electrochemical sensing of 3,5 dichlorophenol (DCp) under optimized experimental and pH conditions. The SnO2@Gr/GC-modified electrode showed enhanced electrochemical performance towards 3,5 Di-Chlorophenol determination. The linear calibration plot was obtained over the concentration range of 200 nM to 3.2 µM (R2 =0.996) and the detection limit (S/N=3) was found to be 8 nM. The nanocomposite modified GC electrode showed good sensitivity also.

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Microsegregation Studies on Pulsed Current Gas Tungsten Arc Welding of Alloy C-276[ ]


Alloy C-276 prone to the formation of Topologically Closed Phases (TCP) at the end of the solidification. The formation of the TCP phases is known to the elemental segregation of Mo and W at the end of the solidification. The present research investigated the possibility of suppressing the elemental segregation by employing current pulsing technique. The weldment was fabricated by Pulsed Current Gas Tungsten Arc (PCGTA) Welding mode. The weld joint was studied with respect to microstructure, microsegregation and mechanical properties. Optical and Scanning electron microscopy were employed to study the microstructural changes in the fusion zone. The extent of microsegregation was studied by Energy-Dispersive Spectroscopy (EDS). Tensile test and bend tests were carried out to evaluate the strength and ductility of the weld joint. The results showed that refined microstructure with narrow Heat Affected Zone (HAZ). Energy-Dispersive Spectroscopy analysis showed that reduced Microsegregation. The tensile results showed that 20 % improved strength compared to the base metal. Bend test didn’t result in any cracking.

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Light Microscopy of Male Reproductive Organs after CdCl2 Exposure: Focus on Morphometric Analysis of Testis and Sperm Parameters[ ]


Cadmium is a widely spread environmental pollutant which exerts various toxic effects in humans and animals. The present study was aimed to explore the effects of a lower dose of Cd on testis and sperm parameters of mice and the possible recovery after one spermatogenic cycle without any treatment. Adult mice grouped controls (groups I and III) were administered with saline, and groups II and IV were subcutaneously injected with 0.5mg/kg/body/weight of CdCl2. Animals were sacrificed after 24h (groups I, and III), and 35 days (groups II and IV), respectively. Testis and epididymis from all groups were processed for light microscopy, morphometric analysis of the seminiferous tubules and sperm parameters. Cadmium dosed groups showed significant differences in the progressive motility and immotile sperm (? <0.05), compared with controls (?> 0.05). Spermatozoa with normal morphology and curled or bent tail showed no significant differences (?> 0.05). The histological features of epididymis sections from treated groups exhibited lesions and together with the morphometric analysis showed significant differences between the seminiferous tubules of Groups II compared to Group I. Although deleterious effects of Cd were noted the recovery study after 35 days showed a great retrieval of lesions in both reproductive organs (groups II, and IV).

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Cr(III)-tris(picolinate) Induced Multi-organ Toxicity on Mice: Microscopy Studies[ ]


The present study aims to explore the effects of a dietary Cr(III) supplement, Cr-tris–picolinate, on mice exposed to different doses of this compound, on relevant organs related to metabolism, excretion, and immune functions. Chromium is an essential nutrient involved in carbohydrate and lipid metabolis im mammals. [Cr(pic)3] is a very popular human dietary supplement that provides a bioavailable form of Cr(III) . However, its mechanism of action at the molecular level remains so far not totally understood and a number of toxic endpoints have been attributed to its use. Back to 90´s of the last century some adverse effects provoked by its use began to be recurrently reported, especially with regard to its ability to promote DNA cleavage by a radical mechanism. Investigation of the effects of diets supplementation with [Cr(pic)3] are essential to assess the safety and the concerns over this material.

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Application of Top Down Micro-Patterned VACNTs in MEMS devices[ ]


Vertically aligned Carbon Nanotubes (CNTs) which are commonly referred to as CNT forests, have many potential engineering applications for its attractive mechanical, electrical, optical, and thermal properties. Various micro patterning methods of VACNTs are used for fabrication of MEMS devices such as pressure sensor, thermometer, switches etc. A new patterning technique recently introduced by our group is named as micro mechanical bending (M2B) of VACNTs. Typically, CNT forest is known to be the darkest material on earth that can almost completely absorb light. This new M2B technique for CNT forest remarkably changes the optical property of the processed zone. The most significant observation made from the processed CNT forest is the visible optical reflection from bent and flattened area. Another interesting property of the resultant is anisotropic behaviour of the surface. The anisotropic and flexible nature of CNT forest has opened the gateway to use these patterned CNT forest as several types of MEMS based sensor, which will be discussed in this paper.

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Synthesis and Characterization of SAPOs Nanomaterial from Aqueous and Non-aqueous Media[ ]


Silicoaluminophosphate (SAPOs) molecular sieves were synthesized from aqueous and non-aqueous media. Effect of crystallization temperature for aqueous media and crystallization time for non-aqueous media were investigated. The synthesized samples were characterized by Powder-XRD, FTIR, and SEM. SAPOs nanomaterial was obtained at 1500 C crystallization temperature for aqueous media. For non-aqueous media, the crystallization time was noticed 72 h for successive crystallization of SAPOs. It is observed that crystal size of SAPOs for non-aqueous media is smaller than aqueous media for it.

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One-Step Hydrothermal Synthesis of Al decorated on Manganese oxide: Characterization, and photocatalytic degradation of malachite Green[ ]


Recently, mesoporous transition metal oxides have received enormous attention because of the unique catalytic properties attributed to high surface area and easy accessibility to active sites. A highly crystalline Al decorated Mn3O4 nanoparticles were prepared by hydrothermal method. Direct evidence of the decorated of Al in the Mn3O4 was observed by the data collected from XRD, FT-IR and UV-Vis techniques. The surface morphology was observed by SEM images. As synthesized nanoparticles act as better photocatalytic activity on Malachite green (MG) dye.

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Synthesis, Characterization and Electrochemical Sensing Properties of CeO2@SiO2[ ]


CeO2@SiO2 nanoparticles were synthesized by thermal decomposition method. The synthesized CeO2@SiO2 was characterised by X-ray diffraction, DRS-UV-Vis and FE-SEM. CeO2@SiO2 nanoparticles were used to modify the glassy carbon electrode (GCE) and the modified electrode was used to detect ranitidine by voltammetric techniques. The determination is based on electrochemical reduction of ranitidine using acetate buffer solution (pH 6). The modified electrodes exhibit better electro catalytic activity than the bare glassy carbon electrode (GCE).

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Microwave Synthesis of tris-(1,10-phenanthroline)vanadium(III) complex and their electrocatalytic activity towards uric acid[ ]


Vanadium is most important biological element which play a vital role in diabetic treatment to the human. In 1899, a report shows the decreasing level of glucose in urine with the aid of sodium vanadate. It is the first report of vanadium used for diabetic patients to know the level of glucose. The insulin mimetic activity of vanadium is the most important area for the research, recent interest has been shown to synthesis of stable vanadium complex with minimum toxicity to the biological system. The vanadium has different oxidation states which exhibit better electrocatalytic activity and sensing ability. The vanadium complex with phenanthroline ligand shows batter stable complex due to planar nature and presence of sp2 hetero nitrogen atoms. Many metal complexes of 1,10-phenanthroline (1,10-phen) and its derivatives often show fascinating chemical and physical properties because of their ?ne p-conjugated character and strong chelating abilities.

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Room temperature Magnetic Studies of phase pure (BiFeO3-NaNbO3)-(P(VDF-TrFE)) Nanocomposite films prepared by spin coating[ ]


(BiFeO3-NaNbO3)-(P(VDF-TrFE)) co-polymer thin films (Ëœ 0.6 µm thickness) were fabricated by spin coating technique and their room temperature magnetic properties were investigated. In order to get the crystallization ‘?’ phase, the films have been annealed at 138o C.

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Luminescent Hydroxyapatite Nanoparticles for Bioim-aging Applications[ ]


Here we report the microwave synthesis of Eu3+ substituted HA nanoparticles and its properties towards bioimaging applications. Photoluminescence studies on Eu3+ substituted HA (Eu-HA) nanoparticles revealed the most intense peak around 617 nm and the fluorescence imaging of the same using confocal microscope exhibited red emission. Hence Eu-HA nanoparticles can be used as a bioprobes for fluorescence targeting.

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Synergetic effect of electron irradiation on the supercapacitive properties of electrodeposited iron oxide thin films[ ]


The present work aims to investigate the effect of electron irradiation on the supercapacitive properties of iron oxide thin films. A supercapacitor electrode with promising features has been developed by modifying iron oxide thin films. High surface area porous iron oxide thin films are deposited by electrodeposition method. As deposited iron oxide thin films were irradiated with electron beam with different doses (10, 30 and 50 kGy). The structural and morphological modification of iron oxide electrodes have been analyzed by XRD, FTIR and SEM and found the change in structure as well as surface morphology of the electron irradiated maghemite electrodes. The electrochemical properties of the proposed electrodes were studied in 0.5 M Na2SO3 electrolyte with cyclic voltammetry, galvanostatic charge discharge and EIS techniques. Specific capacitance of maghemite thin film electrodes has been enhanced from 616 to 678 F/g after electron. Furthermore the samples show long term cycling performance with 16% enhancement in stability after irradiation. Subsequently electrochemical impedance spectroscopy indicates the suitability of the maghemite electrodes for supercapacitor application with decrease in electrode resistance after electron irradiation. The proposed electrodes are easy to prepare, economic, environmentally benign with enhanced stability.

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Elevated substrate temperature implantation of 70 MeV Au in GaAs[ ]


One side polished, single crystal n+ GaAs of <100> orientation, have been implanted with 100 MeV 197Au to the dose of 1e14 ion/cm2 at room temperature and 70 MeV 197Au to the dose of 1e14 ion/cm2 at substrate temperature 100oC separately. Implanted samples were annealed at different temperatures from 100oC to 550oC. Ohmic contacts with Au-Ge-Ni alloy were made on sample before implantation. Temperature dependent current – voltage characteristics of samples implanted at room temperature & annealed at different temperature and room temperature current – voltage characteristics of samples implanted at elevated substrate temperature of 100oC & subsequently annealed at different temperature were recorded. Sample resistance of linear part of characteristics was considered for estimation of defects. The results were compared with similar study using 100 MeV Si and Sn.

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Electrochemical Impedance Spectroscopic Study of Electrodeposited Polyaniline Thin Films[ ]


In the present investigation, polyaniline thin films have been prepared by potentiostatic mode of electrodeposition. The effects of different potentials on structural and electrochemical properties of polyaniline thin films have been investigated. For the structural properties Raman spectroscopy has been used and morphological study was done using field emission scanning electron microscope (FE-SEM) technique. Electrochemical properties were studied by electrochemical impedance spectroscopy (EIS). The electrochemical properties of polyaniline thin films have been studied in 1M Na2SO4 electrolyte. The less charge transfer resistance has been observed for 1.6V/SCE.

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Nickel Oxide Nanoparticles: Synthesis, Characterization and Recyclable Catalyst[ ]


Solid state nanomaterials are of current interesting endeavor for researcher. One of them is catalysis, it is an important field of application for metal and metal oxide nanoparticles (NPs). With this perspective views in the present article, we have summarized synthesis and characterization of nickel oxides nanoparticles by using effective protective agent. The synthesized NiO NPs were characterized by using spectroscopic techniques viz. FTIR spectroscopy, Powder X-ray Diffraction pattern, Ultraviolet-visible Spectroscopy (UV), Energy Dispersive X-ray Spectroscopy (EDS), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Atomic Force Microscopy (AFM) and Thermogravimetry (TG/DTG). The size and morphology behavior of NPs was studied with the help of PXRD, SEM, TEM and AFM which shows particle of varying shapes and sizes. Furthermore, a convenient, alternative and efficient one-pot method was developed for solvent free green synthesis of amidoalkyl napthol derivatives by using nano catalyst through condensation reaction of ß-naphthol, aldehydes and urea with high speed stirring. Present protocol is favored because it offers advantages of high yields, short reaction times, simplicity and easy workup. The efficacy of NPs catalyst exhibited excellent recyclability and reusability up to four times without any additional treatment.

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