270 research outputs found
Corrigendum to: Lattice dynamics in the conformational environment of multilayered hexagonal boron nitride (h-BN) results in peculiar infrared optical responses
No full textDifferently from what is reported in a published version of the paper (Phys. Chem. Chem. Phys., 2021, 23, 7247-7260), F.K. is not considered corresponding author of: 'Lattice dynamics in the conformational environment of multilayered hexagonal boron nitride (h-BN) results in peculiar infrared optical responses'. The relevant correspondence should be addressed to L.C. The authorship of F.K. is recognized to be honorary.</p
Reliability Analysis of an Ultrasonic Guided Wave Based Structural Health Monitoring System for a Carbon Fibre Reinforced Thermoplastic Torsion-box
No full textCertification is the key step towards the implementation of structural health monitoring (SHM) as part of condition based maintenance programmes of aircraft fleets. That can only be accomplished by demonstration of system performance in multiple scenarios and in a statistically relevant way. This paper describes a fully computational approach for reliability assessment of an ultrasonic guided wave (GW) based SHM system for a full-scale stiffened panel of a horizontal stabilizer torsion-box entirely made of carbon fibre reinforced thermoplastic. A pseudo-stochastic nature is attributed to the damage index values calculated from the finite-element signals, allowing hit-miss data to be generated. That data is in turn employed for the computation of probability of detection curves and relative operating characteristics. The results of this research show that detailed damage diagnostics in full-scale complex composite structures can be achieved by using ultrasonic GWs under the hotspot monitoring philosophy. Moreover, it is demonstrated that properly validated models of the monitoring environment can be used for reliability analysis of GW based SHM systems for full-scale complex composite structures, thereby reducing the need for extensive and costly experimental test campaigns, which in turn can contribute to an acceleration of the establishment of a certification framework for SHM systems.Structural Integrity & CompositesAerospace Structures & Material
Toestandsvergelijkingen voor polymeren
No full textVoor vloeistoffen -zowel monomere als polymere- is het opstellen van een theorie die nauwkeurige resultaten geeft voor onder andere de toestandsvergelijking (p,V,T-vergelijking) een nog groter probleem dan voor vaste stoffen (kristallijn) of gassen (ver boven het kritisch punt). Enerzijds heeft men te maken met een systeem dat ongeordend is en anderzijds een hoge dichtheid heeft, waardoor men het "veel deeltjes probleem" principieel niet kan benaderen door alleen paar-interacties te beschouwen. Pogingen om een zo exact mogelijke theorie op te stellen hebben doorgaans als resultaat een zeer ingewikkelde toestandsvergelijking, terwijl juist goede hanteerbaarheid een wenselijke eigenschap is. In deze scriptie zal onder andere een overzicht worden gegeven van in de literatuur voorgestelde toestandsvergelijkingen voor polymeren. Zij vallen globaal uiteen in drie groepen: l) toestandsvergelijkingen oorspronkelijk opgesteld voor monomere vloeistoffen, die direct worden toegepast op polymeren of modificaties van deze modellen voor polymeren; 2) theorieen die direct uitgaan van ketenmolekulen en 3) een aantal zuiver empirische relaties.Applied Science
HETEROSIS AND COMBINING ABILITY FOR RELATED TRAITS IN TOMATO
No full textTomato ( Solanum lycopersicum L.) yields have continued to plummet in
Kenya due to biotic stresses and reliance on low yielding varieties.
This study aimed at determining heterosis and combining ability for
fruit yield and yield components among tomato genotypes and select F1
hybrids combining high fruit yield and other market demanded traits
under Kenyan conditions. Ten parental genotypes and their 45 F1 hybrids
were studied using 10
710 half diallel mating design, excluding the
reciprocals and the self\u2019s. The experiment was set up in Kiambu
and Kirinyaga Counties in Kenya. Out of 45 F1 hybrids evaluated, 89%
had reduced (negative heterosis) days to 50% flowering and 11% days to
maturity, compared to their better parents. Higher heterosis (-9%) was
recorded on days to flowering in AVTO1429 x Cal J VF) and -5% for
maturity in Roma VF x AVTO1314. All the F1 hybrids had positive
heterosis for number of trusses per plant and fruit yield. F1 hybrid
AVTO1429 x AVTO1314 had the highest positive heterosis of 114.39% for
fruit weight per plant yield. The results showed high significant
difference among the ten genotypes for general and specific combining
ability effects (male x female) for all the traits evaluated. There was
additive and non-additive gene action for the traits, which are
important aspects in developing a tomato breeding programme.Les rendements de la tomate (Solanum lycopersicum L.) ont continu\ue9
de chuter au Kenya en raison des stress biotiques et de la
d\ue9pendance aux vari\ue9t\ue9s qui donnent le faible rendement.
Cette \ue9tude visait \ue0 d\ue9terminer
l\u2019h\ue9t\ue9rosis et \ue0 combiner la capacit\ue9 de
rendement en fruits et les composants de rendement parmi les
g\ue9notypes de tomates et s\ue9lectionner des hybrides F1
combinant un rendement \ue9lev\ue9 en fruits et d\u2019autres
caract\ue9ristiques demand\ue9es par le march\ue9 dans les
conditions kenyanes. Dix g\ue9notypes parentaux et leurs 45 hybrides
F1 ont \ue9t\ue9 \ue9tudi\ue9s \ue0 l\u2019aide d\u2019un
plan d\u2019accouplement 10
7 10 demi-diall\ue8le, \ue0
l\u2019exclusion de la s\ue9lection r\ue9currente r\ue9ciproque
et autof\ue9condation. L\u2019exp\ue9rience a \ue9t\ue9 mise
en place dans les comt\ue9s de Kiambu et Kirinyaga au Kenya. Les
89\ua0% de 45 hybrides F1 \ue9valu\ue9s avaient des jours
r\ue9duits (h\ue9t\ue9rosis n\ue9gatif) \ue0 50\ua0% de
floraison et 11\ua0% de jours jusqu\u2019\ue0 maturit\ue9, par
rapport \ue0 leurs meilleurs parents. Une h\ue9t\ue9rosis plus
\ue9lev\ue9e (-9 %) a \ue9t\ue9 enregistr\ue9e sur les jours
pr\ue9c\ue9dant la floraison chez AVTO1429 x Cal J VF) et -5 % pour
la maturit\ue9 chez Roma VF x AVTO1314. Tous les hybrides F1 avaient
une h\ue9t\ue9rosis positive pour le nombre de grappes par plante
et le rendement en fruits. L\u2019hybride F1 AVTO1429 x AVTO1314
pr\ue9sentait l\u2019h\ue9t\ue9rosis positive la plus
\ue9lev\ue9e de 114,39 % pour le rendement en poids de fruit par
plante. Les r\ue9sultats ont montr\ue9 une diff\ue9rence
significative \ue9lev\ue9e entre les dix g\ue9notypes pour les
effets de capacit\ue9 de combinaison g\ue9n\ue9raux et
sp\ue9cifiques (m\ue2le x femelle) pour tous les traits
\ue9valu\ue9s. Il y avait une action g\ue9nique additive et non
additive pour les traits qui sont des aspects importants dans le
d\ue9veloppement d\u2019un programme de s\ue9lection de tomates
Analysis of tomato agronomic traits using generation mean
No full textInformation on inheritance of agronomic traits and lack of tomato (Solanum lycopersicum L.) a robust breeding programme in Kenya, has led to dependency on imported tomato varieties. The objective of this study was to assess the inheritance of growth attributes of tomato lines in Kenya and identify cross family with great potential for further breeding. Six generations; namely P1, P2, F1, F2, BC1P1 and BC1P2‚ were developed from five parental lines. A split-plot design with crosses as main plots and generations as subplots was used in two sites (Kabete Field Station and Mwea Research Station), located in Kenya. Cross Roma VF x AVTO1424 and Roma VF x AVTO1314 were the earliest (33 days) to reach 50% flowering; while BC1P2‚ of Roma VF (38 days) was the latest to flower. Mwea Station had plants with the tallest plants, with a mean height of 62 cm at 50% flowering, compared to Kabete Station with a mean height of 48 cm. A significant increase (>10%) in plant height was registered in F1 generations compared to parental lines. Plant height at maturity across the environments ranged from 82 cm for shorter parent, Roma VF, to 120 cm for taller offspring BC1P1. Significant genotype x environment interactions were observed in Roma VF x AVTO1314 and Roma VF x AVTO1429 for days to 50% flowering, plant height, and number of trusses per plant. The importance of gene effects for agronomic trait inheritance was in additive and dominance-additive portions, which implied that traits were inherited
Analogie-model ter bestudering van knikverschijnselen in het elasto-plastische gebied
No full textCivil Engineering and Geoscience
The influence of scale and electrodetype on the static strenght of welded connections
No full textCivil Engineering and GeosciencesStructural Engineerin
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