545 research outputs found
All degree six local unitary invariants of k qudits
We give explicit index-free formulae for all the degree six (and also degree
four and two) algebraically independent local unitary invariant polynomials for
finite dimensional k-partite pure and mixed quantum states. We carry out this
by the use of graph-technical methods, which provides illustrations for this
abstract topic.Comment: 18 pages, 6 figures, extended version. Comments are welcom
Pyrolysis of plastic waste: effect of feedstock pretreatment and fate of contaminants
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MCMC Algorithms for Supervised and Unsupervised Linear Unmixing of Hyperspectral Images
This book is a collection of 19 articles which reflect the courses given at the Collège de France/Summer school “Reconstruction d'images − Applications astrophysiques“ held in Nice and Fréjus, France, from June 18 to 22, 2012. The articles presented in this volume address emerging concepts and methods that are useful in the complex process of improving our knowledge of the celestial objects, including Earth
Lactic Acid Extraction and Mass Transfer Characteristics in Slug Flow Capillary Microreactors
Capillary microreactors operated under the slug flow regime were investigated for the separation of lactic acid from the aqueous phase using liquid–liquid reactive extraction. The experiments were performed at a 1:1 flow ratio of the aqueous to organic phases in a setup consisting of an inlet Y-type mixer connected with a poly(tetrafluoroethylene) capillary microreactor and subsequently an outlet Y-shape phase splitter. The extraction of lactic acid (intake: 0.11 and 0.055 M in water) using 15% (v/v) tri-n-octylamine in n-octanol under ambient conditions approached equilibrium after about 90 s in microreactors without noticeable emulsion formation. The measured reactive extraction performance in microreactors can be well described by a physical mass transfer model according to the penetration theory (developed from a model experimental study for the extraction of acetanilide from water to n-octanol) combined with an instantaneous irreversible reaction assumption
Titanium Phosphate Grafted on Mesoporous SBA-15 Silica as a Solid Acid Catalyst for the Synthesis of 5-Hydroxymethylfurfural from Glucose
The grafting of titania on SBA-15 followed by its phosphation was presented to prepare a mesoporous Lewis–Brønsted bifunctional solid acid catalyst for the tandem conversion of glucose via fructose to 5-hydroxymethylfurfural (HMF). Titania was dispersed on SBA-15 as an amorphous surface layer containing abundant coordinatively unsaturated tetrahedral Ti ions, which was reactive and readily transformed upon phosphation into a new titanium phosphate phase with the chemical formula identified as Ti2O3(H2PO4)2·2H2O. The ordered mesoporous structure was well maintained after three modification cycles, affording a desirable surface area of over 300 m2/g. The SBA-15-supported titanium phosphate layer affords higher overall acidity and Brønsted to Lewis acid ratio, compared with the conventional post-phosphated bulk anatase titania. The tetrahedral Ti ions and the adjacent protonated phosphate groups on the titanium phosphate layer could form Lewis–Brønsted acid pairs at molecular level proximity, which largely enhanced the selective tandem catalysis for glucose conversion via fructose to HMF. An optimized HMF yield of 71% was achieved at 160 °C in a water–methyltetrahydrofuran biphasic system over the SBA-15-supported titanium phosphate catalyst. The catalyst exhibited good hydrothermal stability with a rather limited silicon and phosphate leaching, and no distinct pore collapse or performance loss over three sequential reaction runs
The protein challenge:Matching future demand and supply in Indonesia
Indonesia has the fourth largest population in the world and in the coming years food production will need to catch up with its growth. To fulfill the protein demand of this growing population, the productivity of the Indonesian agricultural sector should be increased. This can be achieved either by expanding the agricultural land or by increasing the productivity of existing agricultural land and protein use efficiency. An expansion of agricultural land is not always possible or desirable: large parts of Indonesia comprise forest areas, including tropical rain forests. Consequently, the optimization of the use of existing agricultural land is inevitable. The present manuscript describes and discusses the current protein consumption and production in Indonesia. It presents the levels predicted for 2035, which would imply a strong gap between consumption and production. Alternatives therefore need to be considered to avoid protein shortage in the future. These would include the use of new biomass resources, utilization of agricultural residues as alternative protein sources for feed and other nonfood applications, and biorefining of biomass sources.</p
Disorders of sex development : timing of diagnosis and management in a single large tertiary center
Background: We describe the phenotypic spectrum and timing of diagnosis and management in a large series of patients with disorders of sexual development (DSD) treated in a single pediatric tertiary center. Methods: DSD patients who had visited our tertiary center during the survey period (between 2004 and 2014) were identified based on an ICD-10 inquiry, and their phenotypic and molecular genetic findings were recorded from patient charts. Results: Among the 550 DSD patients, 53.3% had 46,XY DSD; 37.1% had sex chromosome DSD and 9.6% had 46,XX DSD. The most common diagnoses were Turner syndrome (19.8%, diagnosed at the mean age of 4.7 +/- 5.5 years), Klinefelter syndrome (14.5%, 6.8 +/- 6.2 years) and bilateral cryptorchidism (23.1%). Very few patients with 46,XY DSD (7%) or 46,XX DSD (21%) had molecular genetic diagnosis. The yearly rate of DSD diagnoses remained stable over the survey period. After the release of the Nordic consensus on the management of undescended testes, the age at surgery for bilateral cryptorchidism declined significantly (P <0.001). Conclusions: Our results show that (i) Turner syndrome and Klinefelter syndrome, the most frequent single DSD diagnoses, are still diagnosed relatively late; (ii) a temporal shift was observed in the management of bilateral cryptorchidism, which may favorably influence patients' adulthood semen quality and (iii) next-generation sequencing methods are not fully employed in the diagnostics of DSD patients.Peer reviewe
Pyrolysis of mixed plastic waste (DKR-350):Effect of washing pre-treatment and fate of chlorine
Pyrolysis of a post-consumer plastic waste stream (DKR-350) has been performed at a laboratory scale in a fixed-bed reactor at 500 °C. DKR-350 is a complex mixture of post-consumer plastics comprising polyethylene, polypropylene, polystyrene, polyethylene terephthalate, clogged materials, multilayer flexibles, together with considerable amounts of biogenic and inorganic residues and halogens. The influence of different washing procedures on feedstock composition and pyrolysis product yields was investigated. Washing effectively lowers the biogenic, inorganic and halogen contents in DKR-350, though does not affect the yield of the desired oil/wax (66 to 69 wt%). 27% of the oil/wax lies in the boiling point range of naphtha and gasoline (150 ppm), showing the presence of recalcitrant organochlorides in the feed. Thus, post-treatment is still required to upgrade it to feedstock for the production of fuels and/or chemicals
Selective tandem catalysis for the synthesis of 5-hydroxymethylfurfural from glucose over in-situ phosphated titania catalysts: Insights into structure, bi-functionality and performance in flow microreactors
5-Hydroxymethylfurfural (HMF) synthesis from glucose over in-situ phosphated titania catalysts is presented. Phosphates were incorporated into titania framework forming a titanium phosphate surface layer, where the coordinatively unsaturated tetrahedral TiO4 units act as water-tolerant Lewis acid site (LAS) and the adjacent protonated phosphate as Brønsted acid site (BAS), together forming Lewis-Brønsted acid pairs at molecular-level proximity. Glucose turnover and HMF selectivity were enhanced due to the rapid fructose transfer from LAS to the adjacent BAS for its dehydration to HMF, facilitating LAS liberation for another glucose turnover. Reactions in a water-2-methyltetrahydrofuran biphasic system in packed-bed microreactors gave 66% HMF yield (from 1 M glucose at 150 °C), where the HMF space time yield is about two orders of magnitude higher than that in batch and the literature work. Phosphate leaching from the catalyst is rather limited, whereas the catalyst deactivated mainly by humin deposition and could be regenerated by calcination
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