Trabalho : do dever ao direito: uma investigação sobre o desenvolvimento do direito do trabalho no Brasil

Orientadora: Thereza Cristina Gosdal; coorientador: Luís Fernando Lopes PereiraMonografia (graduação) - Universidade Federal do Paraná, Setor de Ciências Jurídicas, Curso de Graduação em DireitoResumo: A consolidação do Direito do Trabalho no Brasil está relacionada com o progresso econômico e com o desenvolvimento do modo de produção capitalista em território nacional. O crescimento industrial e a expansão do trabalho assalariado reclamavam instrumentos capazes de regular as relações produtivas. Surgiram, então, as primeiras normas trabalhistas que, após alguns anos, assumiram status constitucional. Com a solidificação do capitalismo, as relações de trabalho adquiriram uma relevância tal, que as diversas Constituições brasileiras ocuparamse deste tema. As mudanças sociais e econômicas ocorridas no país ao longo das últimas décadas foram responsáveis por uma alteração de paradigma acerca do trabalho, que passou, sob a égide constitucional, de "dever" a "direito" socia

DNA Fingerprinting of Pearls to Determine Their Origins

We report the first successful extraction of oyster DNA from a pearl and use it to identify the source oyster species for the three major pearl-producing oyster species Pinctada margaritifera, P. maxima and P. radiata. Both mitochondrial and nuclear gene fragments could be PCR-amplified and sequenced. A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay in the internal transcribed spacer (ITS) region was developed and used to identify 18 pearls of unknown origin. A micro-drilling technique was developed to obtain small amounts of DNA while maintaining the commercial value of the pearls. This DNA fingerprinting method could be used to document the source of historic pearls and will provide more transparency for traders and consumers within the pearl industry

Diopside Needles as Inclusions in Demantoid Garnet From Russia: A Raman Microspectrometric Study

Straight, acicular, colorless solid inclusions in demantoid garnet from the Ural Mountains of Russia were investigated by laser Raman microspectrometry. These “needles,” which occur in association with “horsetail” inclusions (curved, fibrous chrysotile), were identified as diopside. This study also demonstrated that Raman analysis is a highly sensitive method for distinguishing even between isomorphous mineral inclusions in gems, that is, minerals with similar crystal structures but different chemical compositions

Age Determination of Pearls: A New Approach for Pearl Testing and Identification

For this radiocarbon study, 7 saltwater pearls and 3 shells from pearl oysters have been analyzed. The declared ages of the samples range from the mid-19th century to very recent formations. The analyzed data show the potential of the bomb peak time marker to provide additional information when testing pearls. The analyzed pearls could be distinctly separated in pearls of pre- and post-bomb peak ages, in agreement with the distinction based on the declared ages. The analyzed data further reveals the potential of this method to provide supporting evidence for the historic provenience of a pearl or as an indication of a natural or cultured formation of a pearl

Examination of the microstructure and composition of jadeite jade - a combination of X-ray microtomography and petrographic methods

High-quality jadeite jade is one of the most valuable gemstone materials in the jewellery trade. In addition to colour and translucency, mineralogical homogeneity and the absence of cracks are crucial for the quality of jadeite jade. The last two characteristics were investigated using a combination of petrographic methods and X-ray microtomography. High-quality jade monomineralically consists of jadeite and has a fine, polycrystalline structure. However, such high-quality jade was deliberately avoided for the examinations presented here, as the main aim of this study was the identification of different mineralogical phases by X-ray microtomography and their determination by petrographic methods. The overall goal was to create a database in which each mineralogical phase is assigned a characteristic value corresponding to its attenuation coefficient, in order to use non-destructive X-ray microtomography as a tool for the precise examination of mineralogically inhomogeneous jadeite samples. The attenuation coefficient is a material dependent constant with the unit cm -1, which expresses the ability of a mineral phase to attenuate X-rays. With a computer tomography (CT) scan, the values are presented in shades of grey as a tomogram. If the settings remain the same, these values are comparable for measurements on the same device. Comparing the attenuation coefficients of mineral phases to identify their composition is a well-known technique. For this purpose, a program can be used to visualize the minerals present based on their attenuation values (Bam et al. 2020). However, in addition to the density of the material and the energy of the X-rays, the chemical formula of the minerals must be known, which is not the case for unworked jade specimens. In general, the attenuation coefficient decreases with increasing energy of the X-rays, decreasing density of the material and lower atomic numbers of the elements present in the material (Bam et al. 2020)

Unstable Colouration of Padparadscha-like Sapphires

After the October 2016 discovery of a new gem deposit at Bemainty near Ambatondrazaka, Madagascar, a number of sapphires with padparadscha-like colour entered the trade. However, most of these stones were found to have unstable colour, which changes from pinkish orange to more-or-less pure pink after a few weeks in daylight. In this study, the authors investigate the colour stability of padparadscha-type sapphires of metamorphic origin—mainly those originating from Madagascar (Ambatondrazaka and Ilakaka) and Sri Lanka. The 48 samples could be separated into three groups after colour-stability testing: sapphires that did not show a noticeably different appearance (case A); sapphires with a slight-to-moderate colour difference within the padparadscha range (case B); and fancy-colour sapphires showing a distinct change in appearance that fell outside of the padparadscha range (case C). The last situation was especially common for the stones from Ambatondrazaka, thus revealing that careful colour-stability testing is mandatory for proper gemmological identification of any sapphire showing a yellow to orange colour component

A Historic Turquoise Jewelry Set Containing Fossilized Dentine (Odontolite) and Glass

A set of six antique brooches, set with diamondsand light blue cabochons, was investigated withmicroscopy, Raman analysis, and EDXRF spec-troscopy. Most of the cabochons proved to befossilized dentine, also known as odontolite(mineralogically, fluorapatite). The brooches also contained turquoise and artificial glass

A New Method for Detecting Be Diffusion-Treated Sapphires: Laser-Induced Breakdown Spectroscopy (LIBS)

This article describes the first application of laser-induced breakdown spectroscopy (LIBS) to gemology. So far, the detection of Be-diffused sapphire and ruby has been based on LA-ICPMS or SIMS, neither of which is readily available to most laboratories. In this study, we use LIBS to detect beryllium in corundum at very low concentrations (down to ~2 ppm). This technique is a reliable tool for identifying Be diffusion–treated sapphires, and is affordable for most commercial gemological laboratories. As with other laser-based techniques, LIBS may cause slight damage to a gemstone, but this can be minimized by choosing appropriate instrument parameters