1,032 research outputs found
Enhanced hydrogen-rich gas production from waste biomass using pyrolysis with non-thermal plasma-catalysis
A pyrolysis-non-thermal plasma-catalytic system for the increased production of hydrogen-rich gas from waste biomass has been investigated. Plasma processing of the hydrocarbon pyrolysis gases produced a marked increase in total gas yield with plasma-catalysis producing a further modest increase. The product gases were mainly composed of H₂ , CO and CO₂ , which were all increased under plasma and plasma-catalyst conditions. For example, H₂ yield increased from 1.0 mmol g −¹biomass in the absence of plasma to 3.5 mmol g −¹biomass with plasma and to 4.0 mmol g −¹biomass with plasma-catalysis. In addition, in the absence of plasma, the hydrocarbon tar content in the product gas was 420 mg m −³ , but, for non-catalytic plasma conditions, this was reduced to 325 mg m −³ and for plasma-catalytic steam reforming, the tar hydrocarbons were markedly reduced to 150 mg m −³ . The effect of increasing input power for the plasma processing (no catalyst) showed a large increase in total gas, H₂ , CO and CO₂ yield and corresponding decrease in hydrocarbon gas concentration. Plasma-catalysis showed that higher power input had only a small effect on gas yield. Plasma-catalysis was shown to produce lower catalyst coke deposition compared to non-plasma catalytic processing
Superconducting properties of very high quality NbN thin films grown by high temperature chemical vapor deposition
Niobium nitride (NbN) is widely used in high-frequency superconducting
electronics circuits because it has one of the highest superconducting
transition temperatures ( 16.5 K) and largest gap among
conventional superconductors. In its thin-film form, the of NbN is very
sensitive to growth conditions and it still remains a challenge to grow NbN
thin film (below 50 nm) with high . Here, we report on the superconducting
properties of NbN thin films grown by high-temperature chemical vapor
deposition (HTCVD). Transport measurements reveal significantly lower disorder
than previously reported, characterized by a Ioffe-Regel ()
parameter of 14. Accordingly we observe 17.06 K (point of
50% of normal state resistance), the highest value reported so far for films of
thickness below 50 nm, indicating that HTCVD could be particularly useful for
growing high quality NbN thin films
Anterior cruciate ligament reconstruction: A multicenter prospective cohort study evaluating 3 different grafts using same bone drilling method
To compare the clinical outcomes after anterior cruciate ligament
(ACL) reconstruction with bone-patellar tendon-bone autograft (BPTBAu), BPTB
allograft (BPTBAll), or hamstring (semitendinosus-gracilis) tendon autograft
(HTAu), performing bone drilling with same methods in terms of transtibial
drilling, orientation, positioning, and width of femoral and tibial tunnels.
DESIGN: Multicenter prospective cohort study (level of evidence II). SETTING:
Departments of Orthopedic Surgery of Centro Medico Teknon (Barcelona, Spain)
Clinica Universitaria de Navarra (Navarra, Spain), and Clinica FREMAP (Gijon,
Spain). PATIENTS: All patients with ACL tears attending 3 different institutions
between January 2004 and June 2006 were approached for eligibility and those
meeting inclusion criteria finally participated in this study. INTERVENTION: Each
institution was assigned to perform a specific surgical technique. Patients were
prospectively followed after undergoing ACL reconstruction with BPTBAu, BPTBAll,
or HTAu, with a minimum follow-up of 24 months. MAIN OUTCOME MEASURES: Included
knee laxity and International Knee Documentation Committee (IKDC) score. Knee
laxity was assessed with the KT-1000 arthrometer (evaluated with neutral and
external rotation positions) and both Lachman and pivot shift tests. Additional
outcomes included main symptoms (anterior knee pain, swelling, crepitation, and
instability), disturbance in knee sensation, visual analogue scale (VAS) for
satisfaction with surgery, range of motion (ROM), and isokinetic knee strength.
RESULTS: There were no significant differences among the 3 groups for any of the
clinical outcomes, except for a slightly greater KT-1000-measured knee laxity in
external rotation in the BPTBAu compared with the other groups. All patients
demonstrated grade A or B of the IKDC. The mean VAS for satisfaction with surgery
in all patients was 8.5. CONCLUSIONS: The selection of the surgical technique for
ACL reconstruction may be based on the surgeon's preference
Theory of nuclear spin conversion in ethylene
First theoretical analysis of the nuclear spin conversion in ethylene
molecules (13^CCH4) has been performed. The conversion rate was found equal
approx. 3x10^{-4} 1/s*Torr, which is in qualitative agreement with the recently
obtained experimental value. It was shown that the ortho-para mixing in 13^CCH4
is dominated by the spin-rotation coupling. Mixing of only two pairs of
ortho-para levels were found to contribute significantly to the spin
conversion.Comment: 20 pages, 5 eps figure
CWRML: representing crop wild relative conservation and use data in XML
Background
Crop wild relatives are wild species that are closely related to crops. They are valuable as potential gene donors for crop improvement and may help to ensure food security for the future. However, they are becoming increasingly threatened in the wild and are inadequately conserved, both in situ and ex situ. Information about the conservation status and utilisation potential of crop wild relatives is diverse and dispersed, and no single agreed standard exists for representing such information; yet, this information is vital to ensure these species are effectively conserved and utilised. The European Community-funded project, European Crop Wild Relative Diversity Assessment and Conservation Forum, determined the minimum information requirements for the conservation and utilisation of crop wild relatives and created the Crop Wild Relative Information System, incorporating an eXtensible Markup Language (XML) schema to aid data sharing and exchange.
Results
Crop Wild Relative Markup Language (CWRML) was developed to represent the data necessary for crop wild relative conservation and ensure that they can be effectively utilised for crop improvement. The schema partitions data into taxon-, site-, and population-specific elements, to allow for integration with other more general conservation biology schemata which may emerge as accepted standards in the future. These elements are composed of sub-elements, which are structured in order to facilitate the use of the schema in a variety of crop wild relative conservation and use contexts. Pre-existing standards for data representation in conservation biology were reviewed and incorporated into the schema as restrictions on element data contents, where appropriate.
Conclusion
CWRML provides a flexible data communication format for representing in situ and ex situ conservation status of individual taxa as well as their utilisation potential. The development of the schema highlights a number of instances where additional standards-development may be valuable, particularly with regard to the representation of population-specific data and utilisation potential. As crop wild relatives are intrinsically no different to other wild plant species there is potential for the inclusion of CWRML data elements in the emerging standards for representation of biodiversity data
Inference of breed structure in farm animals: Empirical comparison between snp and microsatellite performance
Knowledge of population structure is essential to improve the management and conservation of farm animal genetic resources. Microsatellites, which have long been popular for this type of analysis, are more and more neglected in favor of whole-genome single nucleotide polymorphism (SNP) chips that are now available for the main farmed animal species. In this study, we compared genetic patterns derived from microsatellites to that inferred by SNPs, considering three pairs of datasets of sheep and cattle. Population genetic differentiation analyses (Fixation index, FST ), as well as STRUCTURE analyses showed a very strong consistency between the two types of markers. Microsatellites gave pictures that were largely concordant with SNPs, although less accurate. The best concordance was found in the most complex dataset, which included 17 French sheep breeds (with a Pearson correlation coefficient of 0.95 considering the 136 values of pairwise FST, obtained with both types of markers). The use of microsatellites reduces the cost and the related analyses do not require specific computer equipment (i.e., information technology (IT) infrastructure able to provide adequate computing and storage capacity). Therefore, this tool may still be a very appropriate solution to evaluate, in a first stage, the general state of livestock at national scales. At a time when local breeds are disappearing at an alarming rate, it is urgent to improve our knowledge of them, in particular by promoting tools accessible to the greatest number
Croissance de semi-conducteurs à grand gap
La modélisation et la simulation des procédés de croissance tel que le transport physique en phase vapeur (PVT), le dépôt chimique en phase vapeur (CVD ou HTCVD) et les techniques hybrides (CFPVT), sont suffisamment au point pour être utilisées comme des outils de compréhension des phénomènes physiques couplés et comme des outils de conception de nouveaux procédés et d'optimisation de procédés existants. La modélisation des procédés d'élaboration rassemble plusieurs voies physico-chimiques de complexité variable, depuis des études thermodynamiques et/ou cinétiques jusqu'aux transferts simultanés de matière et de chaleur couplées avec les bases de données et propriétés thermodynamiques et/ou cinétiques et de transport. Différentes voies de modélisation sont utilisées, thermodynamiques, cinétique ou transfert de masse, de façon couplée ou découplée, permettant de visualiser l'évolution de la croissance et ainsi comprendre le rôle complexe et fortement couplé des phénomènes
Clinical Relevance of Dissolution Testing in Quality by Design
Quality by design (QbD) has recently been introduced in pharmaceutical product development in a regulatory context and the process of implementing such concepts in the drug approval process is presently on-going. This has the potential to allow for a more flexible regulatory approach based on understanding and optimisation of how design of a product and its manufacturing process may affect product quality. Thus, adding restrictions to manufacturing beyond what can be motivated by clinical quality brings no benefits but only additional costs. This leads to a challenge for biopharmaceutical scientists to link clinical product performance to critical manufacturing attributes. In vitro dissolution testing is clearly a key tool for this purpose and the present bioequivalence guidelines and biopharmaceutical classification system (BCS) provides a platform for regulatory applications of in vitro dissolution as a marker for consistency in clinical outcomes. However, the application of these concepts might need to be further developed in the context of QbD to take advantage of the higher level of understanding that is implied and displayed in regulatory documentation utilising QbD concepts. Aspects that should be considered include identification of rate limiting steps in the absorption process that can be linked to pharmacokinetic variables and used for prediction of bioavailability variables, in vivo relevance of in vitro dissolution test conditions and performance/interpretation of specific bioavailability studies on critical formulation/process variables. This article will give some examples and suggestions how clinical relevance of dissolution testing can be achieved in the context of QbD derived from a specific case study for a BCS II compound
Annual dune plant communities in the Southwest coast of Europe
This study presents an updated sintaxonomic review of the annual communities from coastal dunes in the Southwest coast of
Europe, specifically in the Iberian Peninsula, including both types: directly influenced by the sea salt spray and not affected
by this influence. The floristic segregation of the different plant associations was obtained by statistical agglomerative
processes (UPGMA, Unweighted Pair Group Method with Arithmetic Mean) plus principal coordinate analysis (PCoA) and
discussed based on the interpretation of phytosociological tables. Three new communities in central western Portugal were
found and are described: Pseudorlayo minusculae-Polycarpietum alsinifoli, Cerastio diffusae-Vulpietum fontqueranae and
Omphalodo kunzinskyanae-Evacietum ramosissimae
A study of the dry forest communities in the Dominican Republic
This paper is a floristic and phytosociological study of the dry forest communities of the Dominican Republic. A total of 69 relevés in dry forest biotopes were carried out. The samples were subsequently subjected to Detrended Correspondence Analysis for the determination and study of possible groupings. The study does not cover tree formations growing on serpentines, nor the so-called semideciduous forests, peculiar to areas with higher rainfall. A total of nine phytocoenoses were identified. The most significant results led to the description of six new phytosociological associations: Simaroubetum berteroani (thorny dry forest on coastal dunes), Phyllostylo rhamnoidis-Prosopidetum juliflorae (southern Dominican disturbed dry forest), Consoleo moniliformis-Camerarietum linearifoliae (dry forest on hard limestones), Lemaireocereo hystricis-Prosopidetum juliflorae (northern Dominican disturbed dry forest), Lycio americani-Prosopidetum juliflorae (disturbed dry forest on saline soils) and Guettardo ellipticae-Guapiretum discoloris (dry forest on flat-topped hillocks in Montecristi). This is an important step forward in the phytosociological and floristic studies of the Caribbean territories.Este trabalho apresenta um estudo florístico e fitossociológico das comunidades de florestas secas da República Dominicana. Um total de 69 amostras foram obtidas pelo método relevé em biótopos florestais secos. As amostras foram posteriormente submetidas à análise de correspondência destendenciada para a determinação e estudo de possíveis agrupamentos. O estudo não abrange formações arbóreas desenvolvidas sobre serpentinitos, nem as chamadas florestas semideciduais, peculiares às áreas de maior pluviosidade. Foram identificados nove fitocenoses. Os resultados mais significativos levaram à descrição de seis novas associações fitossociológicas: Simaroubetum berteroani (floresta espinhosa seca em dunas costeiras), Phyllostylo rhamnoidis-Prosopidetum juliflorae (floresta seca perturbada do sul da República Dominicana), Consoleo moniliformis-Camerarietum linearifoliae (floresta seca sobre calcários compactos), Lemaireocereo hystricis-Prosopidetum juliflorae (floresta seca perturbada do norte da República Dominicana), Lycio americani-Prosopidetum juliflorae (floresta seca perturbada desenvolvida em solos salinos) Guettardo ellipticae-Guapiretum discoloris (floresta seca em colinas de topo achatado em Montecristi). O trabalho realizado representa um importante avanço nos estudos fitossociológicos e florísticos dos territórios do Caribe.This research paper was possible thanks to the sponsorship of the Agencia Española de Cooperación Internacional para el Desarrollo (AECID), under the auspices of the Ministerio de Asuntos Exteriores y de Cooperación de España, which funded the project (cod. A/3499/05)
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