Search results for "pigments."
showing 10 items of 133 documents
PHOSPHOROUS SEED COATING AFFECT TO GERMINATION, PHOTOSYNTHETIC PIGMENTS AND YIELD OF RAPE
2005
Rape (Brassica napus L. var. napus) is long ago-known vegetable of Brassicaceae in agriculture. It is important and valuable oil, forage, green-fertiliser and nectar plant. The experience of last years shows that rape is suitable for growing in conditions of Latvia, but investigations about its cultivars and growing technologies are not wide enough.The phosporus-fertilizer adding in the rape plantations is of great importance for increasing of its productivity. With the aim to reduce the expenses the phosphorus treated rape seeds are made use.In our investigations the velocity of seeds germination, germinating viability, germinating vigour, green pigments” quantity in seed-lobes and seeds” …
Social and technological changes in the ceramic production of the Northern Levant during the LBA/IA transition: New evidence about the Sea People iss…
2019
Abstract The transition from the Late Bronze Age (LBA) to the Iron Age (IA) in the Levant is marked by the collapse of the Egyptian and Hittite empires, which dominated the political scene of the 14th–13th century BCE. The role of the Sea People, groups of migrants who were defeated by the Egyptian king Ramses III around 1175 BCE, is the focal point concerning this period. After the collapse of the LBA empires, written sources disappeared, and the archaeologists’ primary tool to define cultural processes is to analyze the evolution of pottery. Because of this, studies about the distribution of Aegeanizing ceramic production, considered here to have derived from the Sea People culture, can p…
Origin of the natural variation in the storage of dietary carotenoids in freshwater amphipod crustaceans
2020
16 pages; International audience; Carotenoids are diverse lipophilic natural pigments which are stored in variable amounts by animals. Given the multiple biological functions of carotenoids, such variation may have strong implications in evolutionary biology. Crustaceans such as Gammarus amphipods store large amounts of these pigments and inter-population variation occurs. While differences in parasite selective pressure have been proposed to explain this variation, the contribution of other factors such as genetic differences in the gammarid ability to assimilate and/or store pigments, and the environmental availability of carotenoids cannot be dismissed. This study investigates the relati…
A Unique Collection of Palaeolithic Painted Portable Art: Characterization of Red and Yellow Pigments from the Parpalló Cave (Spain).
2016
In this work we analyze the pigments used in the decoration of red and yellow motifs present in the portable art of the Parpallo Cave (Gandia, Spain), one of the most important Palaeolithic sites in the Spanish Mediterranean region. Energy dispersive X-ray fluorescence spectrometry (EDXRF) and spectrophotometry in the visible region (CIEL*a*b*color coordinates and spectral reflectance curves) were used to perform in situ fast analyses of the red and yellow motifs with portable equipment and to characterize their elemental composition and their colorimetric perception, respectively. According to the elemental composition, the intensity of the fluorescence iron signals in red and yellow motif…
Multistage recovery process of seaweed pigments: Investigation of ultrasound assisted extraction and ultra-filtration performances
2017
International audience; The objectives of this study were first to evaluate the performance of seaweed pigments’ recovery through ultrasound assisted extraction (UAE) and ultra-filtration (UF), and second to investigate the membrane fouling mechanism and evidence the threshold flux during filtration. The pigments’ recovery from the extract was performed using 5 kDa and 10 kDa ultra-filtration membranes. Results showed that increasing the extraction temperature in the range of 40–60 °C was proportional to chlorophyll extraction efficiency, while the maximal carotenoid yield was achieved at 50 °C. Ultrasonic power (from 100 W to 300 W) facilitated the extraction of both chlorophylls and carot…
EDXRF analysis of the Pentecost Triptych from the “São Pedro de Miragaia” church (Porto, Portugal)
2013
Abstract EDXRF spectrometry was used to determine the pigment composition of the Pentecost Triptych, a Flemish masterpiece located at the Church of Sao Pedro de Miragaia (Porto, Portugal). The triptych was restored at the beginning of the 20th century and presents a great number of zones with repaints and colour alterations that can be observed on the whole of their surface. The identification of the original pigments and restoration pigments was based on their characteristic colour and the correlation between the detected elements and the named “key elements” of ancient pigments (Ca, Fe, Cu, Hg, Pb,…) and modern pigments (Ti, Ba, Cr, Zn, Co, Cd,…). The analysis of the triptych has been car…
The Painted Silk Panels of Palazzo Barberini at Rome. The Scientific Investigation and Preservation Challenge
2013
Abstract This paper reports the study carried out on the 18th century painted silk panels that cover the walls of the so called Salotto delle sete dipinte in Palazzo Barberini at Rome on the occasion of the conservation work started in 2007. Microscope and spectroscopy investigations were performed in order to study the materials and the realization techniques of the painted silk panels and to evaluate the conservation conditions. Moreover ageing tests were performed in order to evaluate the stability of the consolidant/protective product used for the silk panels.
Archaeometrical Studies of Classic Mayan Mural Painting at Peten: La Blanca and Chilonche
2014
[EN] La Blanca and Chilonche are two of the many Mayan settlements located on the lower reaches of the Mopan river (Department of Petén, Guatemala). The archaeological work conducted by La Blanca Project (University of Valencia, Spain) over the last ten years has revealed the rich polychrome of the monumental architecture of these sites, where the remains of ancient mural paintings are of the highest quality. In order to ascertain the materials and techniques used by painters at each site throughout the Classic period, our research team has recently conducted an analytical study with a multi-technique approach based on the combination of several non destructive and micro-destructive instrum…
Reconstrucción experimental de los procesos de trabajo de óxidos de hierro mediante útiles macrolíticos.Las Coves de Santa Maira
2018
En la unidad mesolítica de Coves de Santa Maria (Castell de Castells, Alicante), se ha recuperado un importante conjunto de macroutillaje lítico asociado a restos de óxidos de hierro. Con el objetivo de investigar los procesos de trabajo en los que estuvieron implicados estas evidencias, se ha realizado una experimentación con cantos y óxidos de hierro obtenidos en las cercanías del yacimiento. Los primeros resultados han aportado una nueva perspectiva metodológica para el análisis y comparación de los equipos experimentales y arqueológicos. En la unitat mesolítica de Coves de Santa Maria (Castell de Castells, Alacant), s'ha recuperat un important conjunt de macroutillaje lític associat a r…
Interspecific differences in carotenoid content and sensitivity to UVB radiation in three acanthocephalan parasites exploiting a common intermediate …
2011
9 pages; International audience; Few endoparasite species are pigmented. Acanthocephalans are an exception however, with several species being characterised by yellow to orange colouration both at the immature (cystacanth) and adult stages. However, the functional and adaptive significance of carotenoid-based colourations in acanthocephalans remains unclear. One possibility is that the carotenoid content of acanthocephalan cystacanths acts as a protective device against ultra-violet radiation (UVR) passing through the translucent cuticle of their crustacean hosts. Indeed, acanthocephalans often bring about behavioural changes in their aquatic intermediate hosts that can increase their expos…