447,116 research outputs found
Standardization of the bio-active compounds (rotenoids) from the extract of local plant species (derris elliptica) using the internal standard method of high performance liquid chromatography (HPLC)
It is well known now that some plant species represent an efficient factory of chemicals, which are manufactured and used as bio-weapons against pest attacks. Extensive work has been done during the last few decades on these potentially useful compounds. During the last few decades a growing interest has been paid for safe agricultural production i.e free residual toxicity hazards to human beings and to the environment. Plant extracts-based biocides possess a great advantage compared with the chemical ones. Their efficacies are also acceptable. Research carried out was to standardize and determine the bio-active compounds from the extract of local plant species (Derris elliptica) using the internal standard method of the isocratic High Performance Liquid Chromatography (HPLC) analysis system. The raw plants were collected from Kota Johor Lama, Johor and sorted to collect the root and stem. Only the root and stem were utilized as a raw material of the extraction process. The root and stem were extracted by using the Normal Soaking Extraction (NSE) method at 28 0C to 30 0C with 95.0 % (v/v) of acetone as a solvent and the solvent-to-solid ratio of the extraction is (10.0 ml/g). The extraction was carried out for 24 hours and further cleaned up to remove fine debris of root and stem prior to determination of the rotenone and its derivatives content. The rotenone cube resin of SAPHYR S.A.R.L (France) was used to verify the appearances of the compounds in the extract. The employed method of analysis shows significant appearances of the bio-active compounds in the extract compared with the commercial grade of rotenone cube resin
Normalization And Matching Of Chemical Compound Names
We have developed ChemHits (http://sabio.h-its.org/chemHits/), an application which detects and matches synonymic names of chemical compounds. The tool is based on natural language processing (NLP) methods and applies rules to systematically normalize chemical compound names. Subsequently, matching of synonymous names is achieved by comparison of the normalized name forms. The tool is capable of normalizing a given name of a chemical compound and matching it against names in (bio-)chemical databases, like SABIO-RK, PubChem, ChEBI or KEGG, even when there is no exact name-to-name-match
Perspectives on Resource Recovery from Bio-Based Production Processes: From Concept to Implementation
Recovering valuable compounds from waste streams of bio-based production processes is in line with the circular economy paradigm, and is achievable by implementing “simple-to-use” and well-established process separation technologies. Such solutions are acceptable from industrial, economic and environmental points of view, implying relatively easy future implementation on pilot- and full-scale levels in the bio-based industry. Reviewing such technologies is therefore the focus here. Considerations about technology readiness level (TRL) and Net Present Value (NPV) are included in the review, since TRL and NPV contribute significantly to the techno-economic evaluation of future and promising process solutions. Based on the present review, a qualitative guideline for resource recovery from bio-based production processes is proposed. Finally, future approaches and perspectives toward identification and implementation of suitable resource recovery units for bio-based production processes are discussed
Use of Desulfovibrio and Escherichia coli Pd-nanocatalysts in reduction of Cr(VI) and hydrogenolytic dehalogenation of polychlorinated biphenyls and used transformer oil
BACKGROUND Desulfovibrio spp. biofabricate metallic nanoparticles (e.g. ‘Bio-Pd’) which catalyse the reduction of Cr(VI) to Cr(III) and dehalogenate polychlorinated biphenyls (PCBs). Desulfovibrio spp. are anaerobic and produce H2S, a potent catalyst poison, whereas Escherichia coli can be pre-grown aerobically to high density, has well defined molecular tools, and also makes catalytically-active ‘Bio-Pd’. The first aim was to compare ‘Bio-Pd’ catalysts made by Desulfovibrio spp. and E. coli using suspended and immobilised catalysts. The second aim was to evaluate the potential for Bio-Pd-mediated dehalogenation of PCBs in used transformer oils, which preclude recovery and re-use.\ud
RESULTS Catalysis via Bio-PdD. desulfuricans and Bio-PdE. coli was compared at a mass loading of Pd:biomass of 1:3 via reduction of Cr(VI) in aqueous solution (immobilised catalyst) and hydrogenolytic release of Cl- from PCBs and used transformer oil (catalyst suspensions). In both cases Bio-PdD. desulfuricans outperformed Bio-Pd E. coli by ~3.5-fold, attributable to a ~3.5-fold difference in their Pd-nanoparticle surface areas determined by magnetic measurements (Bio-PdD. desulfuricans) and by chemisorption analysis (Bio-PdE. coli). Small Pd particles were confirmed on D. desulfuricans and fewer, larger ones on E. coli via electron microscopy. Bio-PdD. desulfuricans-mediated chloride release from used transformer oil (5.6 0.8 g mL-1 ) was comparable to that observed using several PCB reference materials. \ud
CONCLUSIONS At a loading of 1:3 Pd: biomass Bio-PdD. desulfuricans is 3.5-fold more active than Bio-PdE. coli, attributable to the relative catalyst surface areas reflected in the smaller nanoparticle sizes of the former. This study also shows the potential of Bio-PdD. desulfuricans to remediate used transformer oil
Bio-based Renewable Additives for Anti-icing Applications (Phase I)
The performance and impacts of several bio-based anti-icers along with a traditional chloride-based anti-icer (salt brine) were evaluated. A statistical design of experiments (uniform design) was employed for developing anti-icing liquids consisting of cost-competitive chemicals such as bio-based compounds (e.g., sugar beet extract and dandelion extract), rock salt, sodium metasilicate, and sodium formate. The following experimentally obtained parameters were examined as a function of the formulation design: ice-melting capacity and ice penetration at 25°F (−3.9°C) and 15°F (−9.4°C), compressive strength of Portland cement mortar samples after 10 freezethaw/deicer cycles, corrosion rate of C1010 carbon steel after 24-hour immersion, and impact on asphalt binder’s stiffness. One viable formula (“best performer”) was tested for freezing point depression phase diagram (ASTM D1177-88) and the friction coefficient of asphalt pavement treated by this anti-icing formulation (vs. 23 wt.% NaCl) at a certain temperature near 25°F or 30°F after being applied at 30 gallons per lane mile (1 hour after simulated trafficking and plowing). Laboratory data shed light on the selection and formulation of innovative bio-based snow and ice control chemicals that can significantly reduce the costs of winter maintenance operations. This exploratory investigation contributes to more systematic study of optimizing “greener” anti-icers using renewable resources
A numerical model for the fractional condensation of pyrolysis vapours
Experimentation on the fast pyrolysis process has been primarily focused on the pyrolysis reactor itself, with less emphasis given to the liquid collection system (LCS). More importantly, the physics behind the vapour condensation process in LCSs has not been thoroughly researched mainly due to the complexity of the phenomena involved. The present work focusses on providing detailed information of the condensation process within the LCS, which consists of a water cooled indirect contact condenser. In an effort to understand the mass transfer phenomena within the LCS, a numerical simulation was performed using the Eulerian approach. A multiphase multi-component model, with the condensable vapours and non-condensable gases as the gaseous phase and the condensed bio-oil as the liquid phase, has been created. Species transport modelling has been used to capture the detailed physical phenomena of 11 major compounds present in the pyrolysis vapours. The development of the condensation model relies on the saturation pressures of the individual compounds based on the corresponding states correlations and assuming that the pyrolysis vapours form an ideal mixture. After the numerical analysis, results showed that different species condense at different times and at different rates. In this simulation, acidic components like acetic acid and formic acids were not condensed as it was also evident in experimental works, were the pH value of the condensed oil is higher than subsequent stages. In the future, the current computational model can provide significant aid in the design and optimization of different types of LCSs
C-axis lattice dynamics in Bi-based cuprate superconductors
We present results of a systematic study of the c axis lattice dynamics in
single layer Bi2Sr2CuO6 (Bi2201), bilayer Bi2Sr2CaCu2O8 (Bi2212) and trilayer
Bi2Sr2Ca2Cu3O10 (Bi2223) cuprate superconductors. Our study is based on both
experimental data obtained by spectral ellipsometry on single crystals and
theoretical calculations. The calculations are carried out within the framework
of a classical shell model, which includes long-range Coulomb interactions and
short-range interactions of the Buckingham form in a system of polarizable
ions. Using the same set of the shell model parameters for Bi2201, Bi2212 and
Bi2223, we calculate the frequencies of the Brillouin-zone center phonon modes
of A2u symmetry and suggest the phonon mode eigenvector patterns. We achieve
good agreement between the calculated A2u eigenfrequencies and the experimental
values of the c axis TO phonon frequencies which allows us to make a reliable
phonon mode assignment for all three Bi-based cuprate superconductors. We also
present the results of our shell model calculations for the Gamma-point A1g
symmetry modes in Bi2201, Bi2212 and Bi2223 and suggest an assignment that is
based on the published experimental Raman spectra. The
superconductivity-induced phonon anomalies recently observed in the c axis
infrared and resonant Raman scattering spectra in trilayer Bi2223 are
consistently explained with the suggested assignment.Comment: 29 pages, 13 figure
On the Use of Gallic Acid as a Potential Natural Antioxidant and Ultraviolet Light Stabilizer in Cast-Extruded Bio-Based High-Density Polyethylene Films
This study originally explores the use of gallic acid (GA) as a natural additive in bio-based high-density polyethylene (bio-HDPE) formulations. Thus, bio-HDPE was first melt-compounded with two different loadings of GA, namely 0.3 and 0.8 parts per hundred resin (phr) of biopolymer, by twin-screw extrusion and thereafter shaped into films using a cast-roll machine. The resultant bio-HDPE films containing GA were characterized in terms of their mechanical, morphological, and thermal performance as well as ultraviolet (UV) light stability to evaluate their potential application in food packaging. The incorporation of 0.3 and 0.8 phr of GA reduced the mechanical ductility and crystallinity of bio-HDPE, but it positively contributed to delaying the onset oxidation temperature (OOT) by 36.5 °C and nearly 44 °C, respectively. Moreover, the oxidation induction time (OIT) of bio-HDPE, measured at 210 °C, was delayed for up to approximately 56 and 240 min, respectively. Furthermore, the UV light stability of the bio-HDPE films was remarkably improved, remaining stable for an exposure time of 10 h even at the lowest GA content. The addition of the natural antioxidant slightly induced a yellow color in the bio-HDPE films and it also reduced their transparency, although a high contact transparency level was maintained. This property can be desirable in some packaging materials for light protection, especially UV radiation, which causes lipid oxidation in food products. Therefore, GA can successfully improve the thermal resistance and UV light stability of green polyolefins and will potentially promote the use of natural additives for sustainable food packaging applications
Sound transmission testing of polymer compounds
This is the post-print version of the final paper published in Polymer Testing. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2012 Elsevier Ltd.Acoustic properties of polymer compounds are an important consideration for many applications. Currently, there are standard test methods for the determination of these properties. There is, however, no standard for the equipment used in these tests, only a specification for the test conditions. The objective of this work was to evaluate the operation and performance of a bench top laboratory sound testing system for its potential as a simple cost effective method for the initial evaluation of materials that require specific acoustic properties. The work was limited to an investigation of the property of sound transmission loss (STL). A study of the effect of the mounting conditions for the samples on the STL was carried out. Following this, a series of polymer and polymer composite samples was tested. The results presented demonstrate the potential for the testing system as an effective standard test method for the acoustic properties of polymer composites and other materials.Technology Strategy Board, U
Green biotechnology applications for industrial development: opportunities and challenges for cooperation between the EU and the Mercosur
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