Natural source-based graphene as sensitising agents for air quality monitoring

Natural carbon powder has been used as a precursor to prepare two main types of sensitising agents of nitrogen-doped carbon nanoparticles (N-CNPs) and nitrogen-doped graphene quantum dots coupled to nanosheets (N-GQDs-NSs) by using simple treatments of chemical oxidation and centrifugation separation. Characterization based on FTIR, XPS, XRD, Raman spectroscopy, FE-SEM, HR-TEM, AFM, UV-Vis and FL, revealed successful doping carbon nanoparticle with nitrogen with an average plane dimension of 50 nm and relatively smooth surface. The versatility of the prepared samples as sensitising agents was developed and established by exploiting its ability for detection of volatile organic compounds via simple optical fibre based sensing configuration. The comparative experimental studies on the proposed sensor performance indicate fast response achieved at a few tens of seconds and excellent repeatability in exposure to the methanol vapour. The low limit of detection of 4.3, 4.9 and 10.5 ppm was obtained in exposure to the methanol, ethanol and propanol vapours, respectively, in the atmosphere condition. This study gives insights into the chemical/physical mechanism of an enhanced economic optical fibre based gas sensor and illustrates it for diverse sensing applications, especially for chemical vapour remote detection and future air quality monitoring

Development gene data bank of cultured shrimp species in Iran

DNA barcode is a short, standard well known sequence of cytochrome oxidase І gene. By using this DNA sequence can be realized that each animal, plant or fungus belongs to which species. in this research, samples were collected from imported cultured shrimp Litopenaeus vannamei and and 6 Persian Gulf and Oman Sea shrimp species which classified based on traditional systematically as: Penaeus semisulcatus, Fenneropenaeus merguiensis, Metapenaeus affinis, Parapenaeopsis Stylifera and Fenneropenaeus indicus. After examination of DNA barcode sequence, molecular and bioinformatics operations of each sequence in the Consortium for the Barcode of Life (CBOL) and National Center for Biotechnology Information (NCBI), phylogenetic analysis of each sample was determined and similarity of each sample with NCBI and CBOL database was checked and the closest species to each sample were specified. According to the results different samples of L. vannamei, . banded P.semisulcatus, F. merguiensis and F. indicus have more than 97% similarity to the same species of other countries. non banded P.semisulcatus had 80.07% similarity to banded P.semisulcatus, M. affinis samples had 90.3% similarity to Metapenaeus ensis and Parap. Stylifera had 93.44% similarity to Parapenaeopsis coromandelica in the CBOL. This funding confirmed the need for further investigation and possible announcement of new species

Central composite design and genetic algorithm applied for the optimization of ultrasonic-assisted removal of malachite green by ZnO Nanorod-loaded activated carbon

Maximum malachite green (MG) adsorption onto ZnO Nanorod-loaded activated carbon (ZnO-NR-AC) was achieved following the optimization of conditions, while the mass transfer was accelerated by ultrasonic. The central composite design (CCD) and genetic algorithm (GA) were used to estimate the effect of individual variables and their mutual interactions on the MG adsorption as response and to optimize the adsorption process. The ZnO-NR-AC surface morphology and its properties were identified via FESEM, XRD and FTIR. The adsorption equilibrium isotherm and kinetic models investigation revealed the well fit of the experimental data to Langmuir isotherm and pseudo-second-order kinetic model, respectively. It was shown that a small amount of ZnO-NR-AC (with adsorption capacity of 20 mg g(-1)) is sufficient for the rapid removal of high amount of MG dye in short time (3.99 min). (C) 2016 Elsevier B.V. All rights reserved

Chitosan extraction from lobster shells and its grafted with functionalized MWCNT for simultaneous removal of Pb(2+) ions and eriochrome cyanine R dye after their complexation.

Chitosan (CS) extracted from lobster shells (Persian Gulf, Iran), was grafted with amino functionalized multiwalled carbon nanotube (MWCNT). This novel material was characterized by FE-SEM and FT-IR and used for the ultrasound-assisted removal of Pb(2+) ions and eriochrome cyanine R (ECR) dye. A central composite design (SCCD) under response surface methodology was used for studying the influences of important variables in removal process such as initial ECR and Pb(2+) ions concentrations, adsorbent mass and sonication time on the removal efficiency. Linear, 2FI, quadratic and cubic models were performed and a quadratic model was selected for analysis of each response. ANOVA for the quadratic model shows the F-value parameter (820.44 and 537.12 for ECR and Pb(2+) ions removal, respectively) and very low p-value (<0.0001), implying that the model was highly significant for understudy analytes adsorption. To achieve maximum removal, the optimum condition was determined and were set as:19.34 and 18.20mgL(-1),0.018g and 9.35min for initial ECR and Pb(2+) ion concentrations, adsorbent mass and sonication time, respectively. At these optimum conditions, 97.06% of ECR and 99.29% of Pb(2+) ions were removed in a short time

ENTRY AND EXIT FROM FARMING IN NORTH CAROLINA, 1978-87

Herein, we report the first site-selective, Pd(II)-catalyzed, cross-dehydrogenative Heck reaction of indoles in micro flow. By use of a capillary microreactor, we were able to boost the intrinsic kinetics to accelerate former hour-scale reaction conditions in batch to the minute range in flow. The synergistic use of microreactor technology and oxygen, as both terminal oxidant and mixing motif, highlights the sustainable aspect of this process.Hannes P. L. Gemoets, Volker Hessel and Timothy Noë