Energy Consumption During Nanoparticle Production: How Economic is Dry Synthesis?

The production of oxide nanoparticles by selected wet-chemistry or dry processes is compared in terms of energy requirements. Clear differences arise for production using electricity-intensive plasma processes, organic- or chloride-derived flame synthesis and liquid based precipitation processes. In spite of short process chains and elegant reactor design, many dry methods inherently require vastly bigger energy consumption than the multi-step wet processes. Product composition strongly influences the selection of the preferred method of manufacturing in terms of energy requirement: Metal oxide nanoparticles of light elements with high valency, e.g. titania demand high volumes of organic precursors and traditional processes excel in terms of efficiency. Products with heavier elements, more complex composition and preferably lower valency such as doped ceria, zirconia, and most mixed oxide ceramics may be readily manufactured by recently developed dry processe

Preparation of nano-gypsum from anhydrite nanoparticles: Strongly increased Vickers hardness and formation of calcium sulfate nano-needles

The preparation of calcium sulfate by flame synthesis resulted in the continuous production of anhydrite nanoparticles of 20-50nm size. After compaction and hardening by the addition of water, the anhydrite nanoparticles reacted to nano-gypsum which was confirmed by X-ray diffraction, diffuse reflectance IR spectroscopy and thermal analysis. Mechanical properties were investigated in terms of Vickers hardness and revealed an up to three times higher hardness of nano-gypsum if compared to conventional micron-sized construction material. The improved mechanical properties of nano-gypsum could in part be due to the presence of calcium sulfate nano-needles in the nano-gypsum as showed by electron microscop

Energy consumption during nanoparticle production: How economic is dry synthesis?

ISSN:1388-0764ISSN:1572-896

Preparation of nano-gypsum from anhydrite nanoparticles: Strongly increased Vickers hardness and formation of calcium sulfate nano-needles

ISSN:1388-0764ISSN:1572-896

Improved light olefin yield from methyl bromide coupling over modified SAPO-34 molecular sieves

As an alternative to the partial oxidation of methane to synthesis gas followed by methanol synthesis and the subsequent generation of olefins, we have studied the production of light olefins (ethylene and propylene) from the reaction of methyl bromide over various modified microporous silico-aluminophosphate molecular-sieve catalysts with an emphasis on SAPO-34. Some comparisons of methyl halides and methanol as reaction intermediates in their conversion to olefins are presented. Increasing the ratio of Si/Al and incorporation of Co into the catalyst framework improved the methyl bromide yield of light olefins over that obtained using standard SAPO-34

Identification of ancestral gnathostome Gli3 enhancers with activity in mammals.

Abnormal expression of the transcriptional regulator and hedgehog (Hh) signaling pathway effector Gli3 is known to trigger congenital disease, most frequently affecting the central nervous system (CNS) and the limbs. Accurate delineation of the genomic cis-regulatory landscape controlling Gli3 transcription during embryonic development is critical for the interpretation of non-coding variants associated with congenital defects. Here we employed a comparative genomic analysis on fish species with a slow rate of molecular evolution to identify seven previously unknown conserved noncoding elements (CNEs) in Gli3 intronic intervals (CNE15-21). Transgenic assays in zebrafish revealed that most of these elements drive activities in Gli3 expressing tissues, predominantly the fins, CNS, and the heart. Intersection of these CNEs with human disease associated SNPs identified CNE15 as a putative mammalian craniofacial enhancer with conserved activity in vertebrates and potentially affected by mutation associated with human craniofacial morphology. Finally, comparative functional dissection of an appendage-specific CNE conserved in slowly evolving fish (elephant shark), but not in teleost (CNE14/hs1586) indicates co-option of limb specificity from other tissues prior to the divergence of amniotes and lobe-finned fish. These results uncover a novel subset of intronic Gli3 enhancers which arose in the common ancestor of gnathostomes and whose sequence components were likely gradually modified in other species during the process of evolutionary diversification. This article is protected by copyright. All rights reserved

Identification of ancestral gnathostome Gli3 enhancers with activity in mammals

Abnormal expression of the transcriptional regulator and hedgehog (Hh) signaling pathway effector Gli3 is known to trigger congenital disease, most frequently affecting the central nervous system (CNS) and the limbs. Accurate delineation of the genomic cis-regulatory landscape controlling Gli3 transcription during embryonic development is critical for the interpretation of noncoding variants associated with congenital defects. Here, we employed a comparative genomic analysis on fish species with a slow rate of molecular evolution to identify seven previously unknown conserved noncoding elements (CNEs) in Gli3 intronic intervals (CNE15-21). Transgenic assays in zebrafish revealed that most of these elements drive activities in Gli3 expressing tissues, predominantly the fins, CNS, and the heart. Intersection of these CNEs with human disease associated SNPs identified CNE15 as a putative mammalian craniofacial enhancer, with conserved activity in vertebrates and potentially affected by mutation associated with human craniofacial morphology. Finally, comparative functional dissection of an appendage-specific CNE conserved in slowly evolving fish (elephant shark), but not in teleost (CNE14/hs1586) indicates co-option of limb specificity from other tissues prior to the divergence of amniotes and lobe-finned fish. These results uncover a novel subset of intronic Gli3 enhancers that arose in the common ancestor of gnathostomes and whose sequence components were likely gradually modified in other species during the process of evolutionary diversification