Simultaneous Micro Research Articles

Analysis of volatile organic compounds from the the moss Calymperes palisotii Schwaegr.

• Thirteen compounds were identified. • The major compounds were hexanal, 3-methyl-2-pentanone, phenylacetaldehyde, and E-nerolidol, and nine compounds had lower concentrations. • Literature data shows that these compounds from bryophytes or other organisms present toxic, repellent or attractive effects on insects. Bryophytes are natural sources of volatile organic compounds (VOCs) with bioactive properties whese can be used for bioprospecting and biotechnological applications. This study determines the VOC composition from the moss Calymperes palisotii Schwägr. The volatile concentrate of the species was obtained by simultaneous micro hydrodistillation-extraction (SDE), and analyzed by gas chromatography coupled to mass spectrometry (GC/MS). Among 13 compounds, hexanal, 3-methyl-2-pentanone, phenylacetaldehyde, and E-nerolidol were major compounds,. This was first record of the volatile chemical composition of C. palisotii, with some substances was unprecedented in moss species.

High efficient Hg (II) and TNP removal by NH2 grafted magnetic graphene oxide synthesized from Typha latifolia

ABSTRACT The present study for the first time manifests the outstanding potential of amine grafted magnetic graphene oxide (m-GO-NH2) synthesized from Typha latifolia stems for mercury (Hg (II)) and 2,4,6-trinitrophenol (TNP) removal. The adsorption performance of m-GO-NH2 was apprized by considering the impact of the contact time (0–120 min), pH (2–9), adsorbent dose (5–40 mg), and adsorbate concentration (10–50 mg/L). The maximum Hg (II) and TNP removals (∼ 100%) were obtained using 30 mg adsorbent dose in 90 and 75 min, respectively. The best performance of m-GO-NH2 was observed at pH of 7, 20 mg/L Hg (II), and pH of 2, 30 mg/L TNP. According to the Brunauer–Emmett–Teller (BET) analysis, the surface area of GO was 34.81 m2/g and the simultaneous micro and mesoporosity was observed. Regarding the thermodynamic studies, the adsorption procedure was spontaneous and endothermic for Hg (II) followed Redlich-Peterson (R-P) and Freundlich isotherm equations while it was exothermic for TNP, well fitted with Langmuir and R-P isotherms. Kinetic data also indicated a good correlation with pseudo-second-order model. The highest adsorption capacity was estimated as 107.33 and 105.2 mg/g for Hg (II) and TNP, respectively. Accordingly, the proposed m-GO-NH2 can be a promising adsorbent for the elimination of metal and organic contaminants.

Cryo‐3D Printing of Hierarchically Porous Polyhydroxymethylene Scaffolds for Hard Tissue Regeneration

AbstractHigh molecular weight polyhydroxymethylene (PHM) has a repeat unit identical to that of low molecular weight sugar alcohols and exhibits carbohydrate‐like properties. Herein, cryogenic extrusion‐based 3D printing is combined with a phase separation in water to fabricate hierarchically porous PHM scaffolds containing interconnected macro‐, micro‐, and nanopores. As PHM is infusible and insoluble in common solvents, its precursor polyvinylene carbonate (PVCA) dissolved in dimethylsulfoxide (DMSO) is used to 3D print hierarchically porous PVCA scaffolds that are converted into PHM by hydrolysis without impairing the pore architectures. Similar to low‐temperature deposition manufacturing, the PVCA/DMSO freezes on a build platform at −78 °C. However, instead of removing the frozen solvent by sublimation, the frozen scaffold is immersed in water to recover DMSO and to effect phase separation by precipitation. However, the computer‐guided printhead pathway controls macropore formation phase separation of frozen PVCA/DMSO upon contact with water accounts for simultaneous micro‐ and nanopore formation. Contrary to 3D printing of PVCA/DMSO at ambient temperature, this cryo‐3D printing process does not require shear thinning additives and affords significantly improved build precision with macropore sizes variable between 200 and 1500 µm. Cryo‐3D‐printed PHM scaffolds are biocompatible and promote osteoblast proliferation.

Effect of homopolymer in polymerization-induced microphase separation process

We report on the phase separation behaviors of polymerization mixtures containing a polylactide macro-chain transfer agent (PLA-CTA), styrene, divinylbenzene, hydroxyl-terminated PLA (PLA-OH), and a molecular chain transfer agent which enable the ability to tune the pore size of a cross-linked polymer monolith in a facile manner. Cross-linked monoliths were produced from the mixtures via reversible addition-fragmentation chain transfer (RAFT) polymerization and converted into cross-linked porous polymers by selective removal of PLA while retaining the parent morphology. We demonstrate that pore sizes are tunable over a wide range of length scales from the meso- to macroporous regimes by adjusting the ratio of PLA-CTA to PLA-OH in the reaction mixture which causes the phase separation mechanism to change from polymerization-induced microphase separation to polymerization-induced phase separation. The possibility of increasing porosity and inducing simultaneous micro- and macrophase separation was also realized by adjustments in the molar mass of PLA which enabled the synthesis of hierarchically meso- and macroporous polymers.

Triblock copolymer-assisted synthesis of hierarchical ZIF-67 in the presence of 1,3,5-trimenthylbenzene

A hierarchically porous ZIF-67 was successfully synthesized by using non-ionic block copolymers P123 as a supramolecular templating surfactant and 1,3,5-trimethylbenzene (TMB) as a swelling agent. It was noted that TMB was an effective swelling agent to expand the pore size. Pore size distribution analyses reveal that the as-synthesized hierarchical ZIF-67 has a typical trimodal pore size distribution showing simultaneous micro-, meso- and macropore channel systems. Due to the effect of TMB and P123, the diameter of ZIF-67 nanoparticles was about twice of that synthesized with P123 only and larger pores were formed among the enlarged nanoparticles. This strategy is expected to be a facile and efficient method for the preparation of hierarchical ZIF-67.

Application of multilevel analysis approach in management theory

Article history: Received May 12, 2013 Received in revised format 12 August 2013 Accepted 28 September 2013 Available online October 8 2013 Any phenomenon can be considered and analyzed in terms of different perspectives. In multilevel theorists view, structure or structures of the studied phenomenon are used to consider or to analyze it, completely. Level of analysis indicates the purpose of a researcher or theorist that is intended to be explained or justified, like individual, group or organizational levels and then they are generalized. Contrary to multilevel approach, the conventional approach of theorizing considers micro level or macro level. It cannot perform a simultaneous micro–macro level analysis. A multilevel approach characterized by inter-level and multilevel organizational view to organizational phenomena is an attempt to expand the boundaries of knowledge and provide a new plan. This study uses documentary studies to analyze the multi-level approach of theorizing, multilevel models and multilevel analysis.

Migration of selected elements of environmental concern from unaltered pyrite-rich mineralizations to Fe-rich alteration crusts

This study reports the results of simultaneous micro X-ray diffraction (μ-XRD) and micro X-ray fluorescence (μ-XRF) analyses, performed on a partially altered sulphide mineralization fragment sampled within the main waste-rock dump of the Fe–Cu sulphide Libiola Mine (northern Apennines, Italy) at ID18F beamline (ESRF, Grenoble), The study site is characterized by active acid mine drainage processes that, other than acid generation, determine the mobilization of metals and metalloids of environmental concern and other harmful elements that can be concentrated in waters and soils. The Fe-oxyhydroxides that form extensively as the main secondary products of sulphide oxidation processes are the key minerals in controlling the fate of these mobile elements, being able to effectively scavenge most of them through structural incorporation, adsorption, and co-precipitation mechanisms. When they occur as direct replacement of sulphide mineralization, or as precipitates rimming sulphides or filling porosity, they make it possible to reconstruct the mineralogical and chemical evolution of the system, spatially and temporally, and to understand the mechanism of migration and the fate of the toxic elements involved in the whole process. In this study we were able to follow, with micron-scale resolution, the spatial distribution of the chemical elements released during the sulphide- and gangue-mineral alteration and to evaluate their relationships with the newly forming Fe-oxyhydroxides. In particular, the mobility of Ni, Cu, Zn, As, Se, and Mo appears to be controlled by the goethite genesis which is able to take up these elements through several mechanisms such as structural incorporation (Ni), coprecipitation, and/or adsorption.

Deformation behavior of drawn polymer spherulite studied by simultaneous micro SAXS–WAXS and POM

Deformation behavior of drawn polymer spherulite studied by simultaneous micro SAXS–WAXS and POM

Microstructure and material properties of double-network type fibrous (Al 2O 3–m-ZrO 2)/t-ZrO 2 composites

Al 2O 3–(m-ZrO 2)/t-ZrO 2 composites with a novel double-network microstructure were fabricated by multi-pass extrusion process using polymer bound ceramic green body. A simultaneous micro- and macro-level microstructure tailoring was made where unidirectionally aligned two-phase Al 2O 3–(m-ZrO 2) fibers were enclosed in a t-ZrO 2 phase connected in a network formation and this network was further enclosed in a thicker t-ZrO 2 phase. Composite green rods were hot extruded and reassembled in parallel for extrusion and after several passes of extrusion very fine microstructure with dimension of a few micrometers was obtained. Material properties such as hardness, bending strength and fracture toughness were measured for the composites. Microstructure characterization was carried out by SEM technique. In the 4th passed Al 2O 3–(m-ZrO 2)/t-ZrO 2 composites, the outer network of t-ZrO 2 was 15 μm, inner network 0.8 μm and the inner Al 2O 3–(m-ZrO 2) core was 2.5 μm. The highest hardness, fracture strength and toughness values were about 1452 Hv, 1006 MPa and 8.6 MPa m 1/2, respectively, in the sample sintered at 1500 °C.

Simultaneous micro XRF/XRD analysis of highly inhomogeneous samples

Simultaneous micro XRF/XRD analysis of highly inhomogeneous samples

Simultaneous micro steam distillation/solvent extraction for the isolation of semivolatile flavor compounds from cinnamon and their separation by series coupled-column gas chromatography

Simultaneous micro steam distillation/solvent extraction is an efficient method of extracting semivolatile flavor and fragrance compounds from cinnamon for subsequent separation by series coupled-column gas chromatography. With pentane as the extraction solvent and an extraction time of 1.5 h clean extracts requiring no further sample preparation prior to gas Chromatographic analysis are obtained. It is shown that adulteration of cinnamon inner bark oil with leaf oil can be recognized by an elevated concentration of eugenol with respect to the concentration of trans-cinnamaldehyde and the presence of eugenol acetate and safrole in amounts exceeding trace quantities. The principal Cinnamomum species of commerce can be identified in powdered samples based on differences in their characteristic Chromatographic profiles. True cinnamon ( Cinnamomum zeylanicum Nees) can be distinguished from cassia by the presence of eugenol and benzyl benzoate, and the absence of coumarin and δ-cadinene, all minor components, referenced to the extracted amount of trans-cinnamaldehyde. Multivariate analysis of 16 semivolatile compounds commonly found in powdered cinnamon samples is used to classify samples of cinnamon purchased in seven countries.

Micro and Macro GLC Determination of Ethambutol in Biological Fluids

Previously available GLC methods for ethambutol may only be used to measure quantities of drugs much greater than those found in biological fluids such as plasma and dialysate. A previously published GLC method for plasma samples is extended to measure ethambutol in dialysate. A second GLC method, involving derivatization with bis(trimethylsilyl)trifluoroacetamide and subsequent quantitation using a flame-ionization detector, is described for urine samples. With a dualcolumn and dual-detector gas-liquid chromatograph, simultaneous micro (plasma and dialysate) and macro (urine) determinations of ethambutol are possible.

A rapid spectrophotometric procedure for the simultaneous micro determination of carbamazepine and 5,5-diphenyl-hydantoin in blood

Carbamazepine and 5,5-diphenylhydantoin are simultaneously extracted from 100–200 μl blood with 1,2-dichloroethane. 5,5-Diphenylhydantoin is removed by a one-step wash into alkali. The dichloroethane is further washed with acid and then evaporated to dryness. 5,5-Diphenylhydantoin is determined in the alkali washing by a benzophenone procedure; carbamazepine is determined in the dried residue by the 9-methylacridine procedure earlier described. The combined method is rapid, reliable and has a detection threshold of less than 0.1 mg/100 ml for each drug.