Technology, ritual and Anglo-Saxon agrarian production: the biography of a seventh-century century plough coulter from Lyminge, Kent

The discovery of an unusual early medieval plough coulter in a well-dated Anglo-Saxon settlement context in Kent suggests that continentally derived technology was in use in this powerful kingdom centuries before heavy ploughs were first depicted in Late Saxon manuscripts. The substantial investment required to manufacture the coulter, the significant damage and wear that it sustained during use and the circumstances of its ultimate ritual deposition are explored. Investigative conservation, high-resolution recording and metallographic analysis illuminate the form, function and use-life of the coulter. An examination of the deposition contexts of plough-irons in early medieval northern Europe sheds important new light on the ritual actions of plough symbolism in an age of religious hybridity and transformation

Genomic diversity evaluation of populus trichocarpa germplasm for rare variant genetic association studies

Genome-wide association studies are powerful tools to elucidate the genome-to-phenomerelationship. In order to explain most of the observed heritability of a phenotypic trait, asufficient number of individuals and a large set of genetic variants must be examined. Thedevelopment of high-throughput technologies and cost-efficient resequencing of completegenomes have enabled the genome-wide identification of genetic variation at large scale.As such, almost all existing genetic variation becomes available, and it is now possible toidentify rare genetic variants in a population sample. Rare genetic variants that were usuallyfiltered out in most genetic association studies are the most numerous genetic variationsacross genomes and hold great potential to explain a significant part of the missingheritability observed in association studies. Rare genetic variants must be identified withhigh confidence, as they can easily be confounded with sequencing errors. In this study,we used a pre-filtered data set of 1,014 purePopulus trichocarpaentire genomes toidentify rare and common small genetic variants across individual genomes. We comparedvariant calls betweenPlatypusandHaplotypeCallerpipelines, and we further applied strictqualityfilters for improved genetic variant identification. Finally, we only retained geneticvariants that were identified by both variant callers increasing calling confidence. Based onthese shared variants and after stringent qualityfiltering, we found high genomic diversity inP. trichocarpagermplasm, with 7.4 million small genetic variants. Importantly, 377k non-synonymous variants (5% of the total) were uncovered. We highlight the importance ofgenomic diversity and the potential of rare defective genetic variants in explaining asignificant portion ofP. trichocarpa's phenotypic variability in association genetics. Theultimate goal is to associate both rare and common alleles with poplar's wood quality traitsto support selective breeding for an improved bioenergy feedstock

Dobrodružství historické interpretace

Title in English: The Adventure of Historical Interpretation This collection of nineteen essays written by prominent historians demonstrates the diversity of academic approaches. Their work with historical sources, the foundation stone of research, is combined with ethical and aesthetic decision-making, which forms an indisputable part of their work. This is often surprising - both for the readers and themselves. It represents a great intellectual adventure. They cannot invent sources or set arbitrary rules, plots, and twists and turns, as a novelist might. However, they can write a scientific work which is the result of a creative approach

Breeding without Breeding: Is a Complete Pedigree Necessary for Efficient Breeding?

Complete pedigree information is a prerequisite for modern breeding and the ranking of parents and offspring for selection and deployment decisions. DNA fingerprinting and pedigree reconstruction can substitute for artificial matings, by allowing parentage delineation of naturally produced offspring. Here, we report on the efficacy of a breeding concept called “Breeding without Breeding” (BwB) that circumvents artificial matings, focusing instead on a subset of randomly sampled, maternally known but paternally unknown offspring to delineate their paternal parentage. We then generate the information needed to rank those offspring and their paternal parents, using a combination of complete (full-sib: FS) and incomplete (half-sib: HS) analyses of the constructed pedigrees. Using a random sample of wind-pollinated offspring from 15 females (seed donors), growing in a 41-parent western larch population, BwB is evaluated and compared to two commonly used testing methods that rely on either incomplete (maternal half-sib, open-pollinated: OP) or complete (FS) pedigree designs. BwB produced results superior to those from the incomplete design and virtually identical to those from the complete pedigree methods. The combined use of complete and incomplete pedigree information permitted evaluating all parents, both maternal and paternal, as well as all offspring, a result that could not have been accomplished with either the OP or FS methods alone. We also discuss the optimum experimental setting, in terms of the proportion of fingerprinted offspring, the size of the assembled maternal and paternal half-sib families, the role of external gene flow, and selfing, as well as the number of parents that could be realistically tested with BwB

Study effect of additive on PVDF membrane for CO2/N2 gas separation process

Flat sheet asymmetric membranes were produced from homogenous solution of Poly(vinylideneflouride) (PVDF) via phase inversion method using N-methyl-2-pyrrolidone (NMP) as the solvent and Lithium Chloride (LiCl) as an additive. The effect of addition of different ratio of LiCl in the casting solution on the membrane properties and performance were studied. The morphology and cross section of the produced membranes were observed by Scanning Electron Microscope (SEM). Then, the membranes were tested for chemical analysis to define the presence of LiCl in the membrane by using Fourier Transform Infrared (FTIR) spectroscopy. The permeation performances of the membranes were evaluated in terms of permeability and selectivity of the membranes in separating the gaseous mixture by using single gas permeation test. The addition of LiCl into the casting solution definitely improved the morphology and structure of the membrane. The macrovoid formation was suppressed and very fine pores were formed at higher LiCl content. Increasing the LiCl content significantly increased the selectivity of the PVDF membrane to separate the CO2/N2 gases but decreased the amount of the gases that passed through the membrane

Navařování stelitových vrstev na creepově odolné oceli metodou SAW

Cílem této bakalářská práce bylo nalezení postupu navařování stelitové vrstvy na creepově odolnou ocel 21CrMoV5-7 metodou SAW. V teoretické části je nejprve obecně popsána problematika creepu a základní rozdělení creepově odolných ocelí. Dále je pozornost věnována abraznímu opotřebení a tvorbě funkčních povrchových vrstev. Závěr teoretické části je věnován způsobu tvorby návarů s ohledem na metodu SAW, problematice stelitů a rešerši stávajícího stavu navařování stelitových vrstev. Experimentální část práce je zaměřena na nalezení vhodného přídavného materiálu, optimalizaci prvotních procesních parametrů, včetně definování intenzity promíšení s následným jedno i vícevrstvým navařováním metodou SAW. Vlastnosti návaru i ovlivnění podkladového materiálu bylo hodnoceno měřením tvrdosti dle Vickerse. Na základě dosažených výsledků byl hledán vhodný postup tepelného zpracování po svařování.Goal of this bachelor's thesis was to find a right procedure for cladding stellite layers onto a creep resistant steel 21CrMoV5-7 using the SAW method. In the first part of the theoretical portion of the thesis was the issue of creep and the basic division of creep resistant steels discussed. Next the abrasion wear and machining of surface layers was described. End of the theoretical part was dedicated to the SAW method of cladding, matter of stellites and library research of stellite cladding nowadays. Focus of the practical part of this thesis was on finding the right filler material, optimization of primary process parameters including the intensity of mixing with follow-up mono and multiple layer cladding using the SAW method. Both properties of the cladded layer and influence on the base metal were evaluated using the Vickers hardness test. Appropriate heat treatment was found according to results of the experiments