334 research outputs found
Interspecific hybridization within Eucalyptus (Myrtaceae): Subgenus Symphyomyrtus, sections Bisectae and Adnataria
Copyright © 2001 The University of Chicago PressThe potential for interspecific hybridization within the genus Eucalyptus was investigated through controlled pollination and measurement of seedling leaf morphology. Eucalyptus gillii and E. socialis (subgen. Symphyomyrtus sect. Bisectae ser. Subulatae) were used as the female parents, and pollen was sourced from 16 Eucalyptus species from a number of series within sections Bisectae and Adnataria (subgen. Symphyomyrtus). Thirty-four out of 36 crosses produced seeds; however, the percentage of seeds produced per flower pollinated varied considerably between crosses, as did germination percentage and seedling survival. At 3 mo of age, all surviving seedlings were measured for 15 leaf and stem characters. Multivariate analysis (ordination) of the data from each cross placed the seedlings in relation to their parents, with most crosses intermediate, albeit closer to the maternal parent. Successful hybridization occurred within sect. Bisectae ser. Subulatae and between ser. Subulatae and sect. Bisectae ser. Kruseanae, ser. Levispermae, ser. Curviptera, ser. Erectae and sect. Adnataria ser. Heterophloiae. In contrast, crosses between sect. Bisectae ser. Subulatae and sect. Adnataria ser. Aquilonares and ser. Melliodorae did not produce hybrids. Crosses between closely related species showed a greater degree of success than those between distant crosses, as did those between species with similar flower size.K. L. Delaporte; J. G. Conran; M. Sedgle
Direct observation of lithium metal dendrites with ceramic solid electrolyte
Dendrite formation, which could cause a battery short circuit, occurs in batteries that contain lithium metal anodes. In order to suppress dendrite growth, the use of electrolytes with a high shear modulus is suggested as an ionic conductive separator in batteries. One promising candidate for this application is Li7La3Zr2O12 (LLZO) because it has excellent mechanical properties and chemical stability. In this work, in situ scanning electron microscopy (SEM) technique was employed to monitor the interface behavior between lithium metal and LLZO electrolyte during cycling with pressure. Using the obtained SEM images, videos were created that show the inhomogeneous dissolution and deposition of lithium, which induce dendrite growth. The energy dispersive spectroscopy analyses of dendrites indicate the presence of Li, C, and O elements. Moreover, the cross-section mapping comparison of the LLZO shows the inhomogeneous distribution of La, Zr, and C after cycling that was caused by lithium loss near the Li electrode and possible side reactions. This work demonstrates the morphological and chemical evolution that occurs during cycling in a symmetrical Li–Li cell that contains LLZO. Although the superior mechanical properties of LLZO make it an excellent electrolyte candidate for batteries, the further improvement of the electrochemical stabilization of the garnet–lithium metal interface is suggested
Understanding the Reactivity of a Thin Li1.5Al0.5Ge1.5(PO4)3 Solid-State Electrolyte toward Metallic Lithium Anode
The thickness of solid-state electrolytes (SSEs) significantly affects the energy density and safety performance of all-solid-state lithium batteries. However, a sufficient understanding of the reactivity toward lithium metal of ultrathin SSEs (<100 µm) based on NASICON remains lacking. Herein, for the first time, a self-standing and ultrathin (70 µm) NASICON-type Li1.5Al0.5Ge1.5(PO4)3 (LAGP) electrolyte via a scalable solution process is developed, and X-ray photoelectron spectroscopy reveals that changes in LAGP at the metastable Li–LAGP interface during battery operation is temperature dependent. Severe germanium reduction and decrease in LAGP particle size are detected at the Li–LAGP interface at elevated temperature. Oriented plating of lithium metal on its preferred (110) face occurs during in situ X-ray diffraction cycling
Interlaboratory development and proposition for a new quality control sample for chemical forensics analysis of chemical warfare agents
A new quality control (QC) test sample for gas chromatography–mass spectrometry (GC–MS) was created and analysed to test the comparability and repeatability of chemical forensics results within the Organisation for the Prohibition of Chemical Weapons (OPCW)–designated laboratories. The QC test sample was designed in collaboration between four laboratories and consists of 27 compounds which evaluate the performance of GC–MS instruments. This solution was analysed with GC–MS(EI) in 11 laboratories, seven of which were OPCW designated. The participating laboratories analysed the sample multiple times on consecutive days, as well as after the analysis of a set of complex matrix samples. Retention times, retention indices, peak areas, peak tailing values, signal-to-noise ratios, and isotope ratios were extracted from the GC–MS data, and statistical multivariate analyses with principal component analysis and Hotelling's T2-tests were conducted. The results from these analyses indicate that differences between GC–MS analyses by multiple laboratories were not statistically significant at the 5% level, as the approximate p-value for the null hypothesis of “no differences between the runs” was 0.69. However, similar data processing methods and data normalisation are essential for enabling the reliable comparison of chemical fingerprints between laboratories. A composition for the QC sample and criteria for acceptable GC–MS performance for chemical forensics are proposed. The composition and criteria differ from the currently used chemical weapons verification analysis QC sample by e.g. broadening the range for retention index calculations by addition of new alkane compounds, including new chemicals with concentrations close to the limit of detection (10–100 ng/ml), and including compounds with higher polarity to emulate real-life forensic samples. The proposed criteria include monitoring of retention indices, isotope ratios, peak tailing, signal-to-noise ratios, peak height, mass spectra, and sensitivity of the instrument. The new compounds and criteria will be the subject of future confidence building exercises to validate their relevancy on a large scale.</p
50. Évaluation prospective multicentrique de la qualité de vie en cas de reconstruction mammaire immédiate après mastectomie pour cancer du sein invasif
Cracking in asphalt materials
This chapter provides a comprehensive review of both laboratory characterization and modelling of bulk material fracture in asphalt mixtures. For the purpose of organization, this chapter is divided into a section on laboratory tests and a section on models. The laboratory characterization section is further subdivided on the basis of predominant loading conditions (monotonic vs. cyclic). The section on constitutive models is subdivided into two sections, the first one containing fracture mechanics based models for crack initiation and propagation that do not include material degradation due to cyclic loading conditions. The second section discusses phenomenological models that have been developed for crack growth through the use of dissipated energy and damage accumulation concepts. These latter models have the capability to simulate degradation of material capacity upon exceeding a threshold number of loading cycles.Peer ReviewedPostprint (author's final draft
Living with myotonic dystrophy; what can be learned from couples? a qualitative study
Contains fulltext :
96062.pdf (publisher's version ) (Open Access)BACKGROUND: Myotonic dystrophy type 1 (MD1) is one of the most prevalent neuromuscular diseases, yet very little is known about how MD1 affects the lives of couples and how they themselves manage individually and together. To better match health care to their problems, concerns and needs, it is important to understand their perspective of living with this hereditary, systemic disease. METHODS: A qualitative study was carried out with a purposive sample of five middle-aged couples, including three men and two women with MD1 and their partners. Fifteen in-depth interviews with persons with MD1, with their partners and with both of them as a couple took place in the homes of the couples in two cities and three villages in the Netherlands in 2009. Results : People with MD1 associate this progressive, neuromuscular condition with decreasing abilities, describing physical, cognitive and psychosocial barriers to everyday activities and social participation. Partners highlighted the increasing care giving burden, giving directions and using reminders to compensate for the lack of initiative and avoidant behaviour due to MD1. Couples portrayed the dilemmas and frustrations of renegotiating roles and responsibilities; stressing the importance of achieving a balance between individual and shared activities. All participants experienced a lack of understanding from relatives, friends, and society, including health care, leading to withdrawal and isolation. Health care was perceived as fragmentary, with specialists focusing on specific aspects of the disease rather than seeking to understand the implications of the systemic disorder on daily life. CONCLUSIONS: Learning from these couples has resulted in recommendations that challenge the tendency to treat MD1 as a condition with primarily physical impairments. It is vital to listen to couples, to elicit the impact of MD1, as a multisystem disorder that influences every aspect of their life together. Couple management, supporting the self-management skills of both partners is proposed as a way of reducing the mismatch between health services and health needs
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