Abstract: Stable emissive carbon nanodots were generated in zeolite crystals using near infrared photon irradiation gradually converting the occluded organic template, originally used to synthesize the zeolite crystals, into discrete luminescent species consisting of nano-sized carbogenic fluorophores, as ascertained using Raman microscopy, and steady-state and time-resolved spectroscopic techniques. Photoactivation in a confocal laser fluorescence microscope allows 3D resolved writing of luminescent carbon nanodot patterns inside zeolites providing a cost-effective and non-toxic alternative to previously reported metal-based nanoclusters confined in zeolites, and opens up opportunities in bio-labelling and sensing applications.

Abstract: Oxygen-permeable perovskites with mixed ionic-electronic conducting properties can play an important role in carbon capture and storage techniques. Their ability to separate oxygen from air is needed, more specifically, in oxy-fuel and pre-combustion technologies. In this work, the first detailed comparative analysis and new results are reported on four types of Ba0.5Sr0.5Co0.8Fe0.2O3-delta (BSCF) capillary membranes: non-coated sulphur-containing; catalyst-coated sulphur-containing; non-coated sulphur-free and catalyst-coated sulphur-free. The fabrication of BSCF capillaries by a spinning technique based on phase inversion is further discussed and their oxygen separation performances are interpreted. The comparison of the performance of these different generations of BSCF capillaries of similar dimensions demonstrates a significant impact of the sulphur contamination on both the oxygen flux through the membrane and the activation energy of the overall oxygen transport mechanism. Careful attention is paid to the effect of activation layers on both sulphur-free and sulphur-containing types of capillaries. Additional long-term testing of the sulphur-free BSCF capillaries is presented, where partial decomposition of the membrane surface was observed due to kinetic demixing. (c) 2012 Elsevier B.V. All rights reserved.

Abstract: Polycrystalline boron-doped superconducting diamond, synthesized at high pressure and high temperature (HPHT) via a reaction of a single piece of crystalline boron with monolithic graphite, has been investigated by analytical transmission electron microscopy. The local boron distribution and boron environment have been studied by a combination of (scanning) transmission electron microscopy ((S)TEM) and spatially resolved electron energy-loss spectroscopy (EELS). High resolution TEM imaging and EELS elemental mapping have established, for the first time, the presence of largely crystalline diamond-diamond grain boundaries within the material and have evidenced the presence of substitutional boron dopants within individual diamond grains. Confirmation of the presence of substitutional B dopants has been obtained through comparison of acquired boron K-edge EELS fine structures with known references. This confirmation is important to understand the origin of superconductivity in polycrystalline B-doped diamond. In addition to the substitutional boron doping, boron-rich inclusions and triple-points, both amorphous and crystalline, with chemical compositions close to boron carbide B4C, are evidenced. (C) 2015 Elsevier Ltd. All rights reserved.

Abstract: A novel strategy to sense target molecules in human blood serum is achieved by immobilizing aptamers (APTs) on multiwalled carbon nanotubes (MWCNT) modified electrodes. In this work, the aminated aptamer selected for hydroxylated polychlorinated biphenyl (OHPCB) was covalently immobilized on the surface of the MWCNTCOOH modified glassy carbon electrode through amide linkage. The aptamers function as recognition probes for OHPCB by the binding induced folding of the aptamer. The developed aptasensing device was characterized by Electrochemical Impedance Spectroscopy (EIS), Atomic Force Microscopy (AFM) and Fourier Transform Infrared Spectroscopy (FTIR). The aptasensor displayed excellent performance for OHPCB detection with a linear range from 0.16 to 7.5 μM. The sensitivity of the developed aptasensing platform is improved (1×10−8 M) compared to the published report (1×10−6 M) for the determination of OH-PCB (Turner et al., 2007). The better performance of the sensor is due to the unique platform, i.e. the presence of APTs onto electrodes and the combination with nanomaterials. The aptamer density on the electrode surface was estimated by chronocoulometry and was found to be 1.4×1013 molecules cm−2. The validity of the method and applicability of the aptasensor was successfully evaluated by the detection of OHPCB in a blood serum sample. The described approach for aptasensing opens up new perspectives in the field of biomonitoring providing a device with acceptable stability, high sensitivity, good accuracy and precision.

Abstract: By means of laser microprobe mass analysis (LAMMA) platinum was detected in the renal proximal tubular cells of a dog that had been intravenously adminstered the antitumor drug cisplatin (5 mg per kg body weight). No definite subcellular localization of the heavy metal was obtained. Sample prparation and analytical features are examined to increase spatial resolution of analysis while maintaining sufficient detection efficiency. The LAMMA method is destructive, but the amount and type of evaporated material can readily be determined when using LAMMA in combination with transmission electron microscopy. Instrumental optimization and standardization of mass signals is possible by using platinum-loaded, ion chelating resin beads embedded and sectioned with the tissue.

Abstract: The main purpose of this research is to manage simultaneous measurement of velocity and concentration in large cross-sections by recording and processing images of cloud structures to provide more detailed information for e.g. validation of CFD simulations. Dispersion from an isolated stack in an Atmospheric Boundary Layer (ABL) was chosen as the test case and investigated both experimentally and numerically in a wind tunnel. Large Scale-Particle Image Velocimetry (LS-PIV), which records cloud structures instead of individual particles, was used to obtain the velocity field in a vertical plane. The concentration field was determined by two methods: Aspiration Probe (AP) measurements and Light Scattering Technique (LST). In the latter approach, the same set of images used in the LS-PIV was employed. The test case was also simulated using the CFD solver FLUENT 6.3. Comparison between AP measurements and CFD revealed that there is good agreement when using a turbulent Schmidt number of 0.4. For the LST measurements, a non-linear relation between concentration and light intensity was observed and a hyperbolic-based function is proposed as correction function. After applying this correction function, a close agreement between CFD and LST measurements is obtained. (C) 2009 Elsevier Ltd. All rights reserved.

Abstract: Trace elements found in aerosols were monitored in Jerusalem during the 1979 winter season utilizing an X-ray fluoresence technique. Most of the particulate mass was associated with the natural soil elements, such as Ca, Fe, K and Ti. Only a small fraction of the mass was comprised of elements clearly emitted from human sources, e.g. Pb, Br, V, Ni and Zn. An excellent correspondence was found between the enrichment factors observed in this study and those postulated for other parts of the world. However, the concentration of Ca and Sr in the Jerusalem suspended dust is substantially higher when compared with world averages of urban aerosols.

Abstract: Aquafeeds contain protein ingredients such as fishmeal and soybean meal, yet their production puts pressure on the environment. Finding novel protein sources such as dried microbial biomass produced on recovered or renewable resources, so-called single-cell protein or microbial protein, can contribute to a more sustainable aquaculture industry. New microbial protein sources are emerging with photoheterotrophic grown purple non‑sulfur bacteria (PNSB) showing high potential, yet research of PNSB as added-value protein ingredient is limited. This research studied their use as a protein source for the white leg shrimp (Penaeus vannamei) and investigated the shrimp's tolerance against Vibrio and ammonia stress. A 28-day shrimp feeding trial was performed with a commercial formulation without PNSB as experimental control (diet i), two pure PNSB species, namely Rhodopseudomonas palustris (diets ii-iii), Rhodobacter capsulatus (diets iv-v) at two protein inclusion levels of 5 and 11 g PNSBprotein 100 g−1 feedprotein and a PNSB enriched culture at a protein inclusion level of 11 g PNSBprotein 100 g−1 feedprotein (diet vi). For the shrimp fed with Rb. capsulatus, 5–25% higher individual weights (p < .05) and better feed conversion ratios were observed relative to the commercial diet (1.3–1.4 vs. control 1.7 g feed g−1 biomass; p < .05). The diet containing Rps. palustris at 5 g PNSBprotein 100 g−1 feedprotein inclusion also showed higher individual weights (26%, p < .05) and a better feed conversion ratio compared to the commercial feed (1.3 vs. control 1.7 g feed g−1 biomass; p < .05). The challenge test subsequent to the feeding trial showed a higher tolerance against ammonia (3 mg N L−1) for shrimp fed with Rps. palustris (survival 63–75% vs. 8% commercial diet; p < .05). For a post-feeding challenge test with Vibrio parahaemolyticus TW01, mortality rates were equal among all treatments. Yet, in vitro tests in 96-Well plates and agar spot assays showed that the PNSB species (i) Rps. palustris, (ii) Rb. capsulatus, (iii) Rb. sphaeroides, (iv) Rhodospirillum rubrum and (v) Afifella marina suppressed the pathogens V. parahaemolyticus TW01 and V. campbellii LMG 21363. Overall, this study demonstrated the potential of PNSB as an added-value protein ingredient in shrimp nursery feed. This can contribute to a circular economy, as PNSB can be cultivated on recovered or renewable resources (e.g. wastewater).

Abstract: Variations in local bond length and coordination in boron-doped nanocrystalline diamond (NCD) films have been studied through changes in the fine structure of boron and carbon K-edges in electron energy-loss spectra, acquired in a scanning transmission electron microscope. The presence of high concentrations of B in pristine diamond regions and enrichment of B at defects in single NCD grains is demonstrated. Local bond length variations are evidenced through an energy shift of the carbon 1s → σ* edge at B-rich defective regions within single diamond grains, indicating an expansion of the diamond bond length at sites with local high B content.

Abstract: The fabrication of n-type diamond is essential for the realization of electronic components for extreme environments. We report on the growth of a 66 mu m thick homoepitaxial phosphorus-doped diamond on a (110)-oriented diamond substrate, grown at a very high deposition rate of 33 mu m h(-1). A pristine diamond lattice is observed by high resolution transmission electron microscopy, which indicates the growth of high quality diamond. About 2.9 x 10(16) cm(-3) phosphorus atoms are electrically active as substitutional donors, which is 60% of all incorporated dopant atoms. These results indicate that P-doped (110)-oriented diamond films deposited at high growth rates are promising candidates for future use in high-power electronic applications. Published by AIP Publishing.

Abstract: Polycrystalline diamond (PCD) was grown onto high-k dielectric passivated AlGaN/GaN-on-Si high electron mobility transistor (HEMT) structures, with film thicknesses ranging from 155 to 1000 nm. Transient thermoreflectance results were combined with device thermal simulations to investigate the heat spreading benefit of the diamond layer. The observed thermal conductivity (k(Dia)) of PCD films is one-to-two orders of magnitude lower than that of bulk PCD and exhibits a strong layer thickness dependence, which is attributed to the grain size evolution. The films exhibit a weak temperature dependence of k(Dia) in the measured 25-225 degrees C range. Device simulation using the experimental jDia and thermal boundary resistance values predicts at best a 15% reduction in peak temperature when the source-drain opening of a passivated AlGaN/GaN-on-Si HEMT is overgrown with PCD. Published by AIP Publishing.