Throughout 2020, the Spanish Government initiated the process of regulating all activities related to platform work with the purpose of ‘chasing the fraud of bogus self-employment’ (PSOE and Unidas ...Podemos, 2020). Somewhat surprisingly, this initiative was met by a substantial wave of protest from the workers who the government proclaimed to be attempting to protect. In this light, the present research explores the arguments of the Spanish sí soy autónomo (yes I am self-employed) movement in its struggle against the Spanish Government. Drawing from a critical discourse analysis of semi-structured interviews to couriers of Uber Eats, Deliveroo and Glovo, as well as to a representative of an association in favour of the preservation of the self-employed status (N = 20), the main finding is that the pursuit of self-employment status is primarily informed by workers’ attempt to escape the precarious working conditions offered to wage-earners in the Spanish labour market as a whole, rather than by an empirically grounded claim. This suggests that new labour legislation addressing the challenges posed by platform work must not overlook the broader context in which it is intended to unfold – otherwise, it may not only fail to improve the workers’ situation, but also drive them to demand what are, actually, further deregulated legal arrangements. As such, this article’s main contribution to the sociological knowledge consists of pointing out that platform work, specificities notwithstanding, cannot be seen as detached from the broader Work landscape.
The abrupt lockdown experienced by a big part of the world population due to the COVID-19 pandemic has bestowed upon home delivery services an unexpected importance. Officially considered amongst ...“essential services”, their workers circulate freely while most people are advised (when not forced) to stay in their homes. The present paper explores how this context helps to shed light on the precarious situation of the majority of the platform delivery workers (PDW). This is done through in-depth, semi-structured interviews and digital ethnography of the interactions within a WhatsApp group. The main finding is that the COVID-19 context deepened the precarization of the PDW confronting them with four dilemmas from which there is no way out.
•The COVID-19 deeply increased the precarity levels of platform delivery workers.•Precarious workers often find themselves facing immensely hazardous dilemmas.•Rented accounts among platform delivery workers is an under-studied phenomenon.
Bladder cancer (BC) stands as one of the most prevalent urological malignancies, with over 500 thousand newly diagnosed cases annually. Treatment decisions in BC depend on factors like the risk of ...recurrence, the type of tumor, and the stage of the disease. While standard therapeutic approaches encompass transurethral resection of the bladder tumor, radical cystectomy, and chemo- or immunotherapy, these methods exhibit limited efficacy in mitigating the aggressive and recurrent nature of bladder tumors. To overcome this challenge, it is crucial to develop innovative methods for monitoring and predicting treatment responses among patients with BC. Metabolomics is gaining recognition as a promising approach for discovering biomarkers. It has the potential to reveal metabolic disruptions that precisely reflect how BC patients respond to particular treatments, providing a revolutionary method to improve accuracy in monitoring and predicting outcomes. In this article, we present a comprehensive review of studies employing metabolomics approaches to investigate the metabolic responses associated with different treatment modalities for BC. The review encompasses an exploration of various models, samples, and analytical techniques applied in this context. Special emphasis is placed on the reported changes in metabolite levels derived from these studies, highlighting their potential as biomarkers for personalized medicine in BC.
A notable advantage of the GTAW process with the use of a hot wire is the higher deposition rate, which can be twice as high as that achieved with a cold wire for the same welding current. In the ...conventional procedure, the wire is heated through the passage of current to create heat by the Joule Effect. However, due to the interaction of the magnetic fields generated by the currents which circulate through the wire and the arc, the deflection of the arc (by magnetic blow) occurs. This paper describes the conception, construction and evaluation of a wire heating system based on electromagnetic induction, aimed at minimizing or even eliminating the problems inherent to the conventional heating technique of passing a current. The induction heating method was applied in the hot wire GTAW process (resulting in the IHW-GTAW technique), using different values for the welding current (100, 150 and 200 A) and coil currents between 20 and 120 A. For the same welding current, a gain of up to 220 % could be achieved in the deposition rate by preheating the wire with the IHW-GTAW technique, when compared with the rate achieved with the cold wire (CW-GTAW) method, showing a high heating efficiency. No magnetic blow or arc instability was observed with the induction heating method. In addition, because it can operate without the need for permanent contact of the wire with the molten pool (as the secondary arcing observed with the conventional heating method does not occur), other applications are envisaged, such as GTAW with tangential wire feeding, GTAW with dynamic feeding, hot wire techniques using laser and GMAW processes, as well as brazing.
The evolution of technology is directed to reduce industrial waste from chemical processes to zero. In the past decade interest in ionic liquids (ILs) has grown, and they have been recognized as ...potential substitutes for volatile organic solvents used in certain chemical processes, including those in the pharmaceutical industry. Following this increasing interest and because ILs can have a great potential for the pharmaceutical industry, we tested the solubility of two antitubercular medicines, pyrazinecarboxamide and isoniazid, in imidazolium ionic liquids, namely C4mimBF4, C4mimPF6, C4mimOTf, and C8mimOTf, in the range of 279.98 to 417.05 K. Both drugs exhibited an improved solubility in C4mimBF4 than in the other studied ILs. The solutes had an enhanced solubility in more hydrophilic ILs, such as C4mimBF4 and C4mimPF6. The solubility decreased in ILs containing the hydrophobic anion trifluoromethanesulfonate and with the increasing alkyl chain length in the cation. The solid–liquid phase equilibria of all investigated systems were described using six different correlation equations. The satisfactory results which revealed a good description with an acceptable standard deviation temperature range were collected for isoniazid or pyrazinecarboxamide in C4mimPF6, C4mimOTf and C8mimOTf. Comparison to solubility in NTf2 and C10mimOTf was provided.
Araújo, N. (2023). História do cinema. Dos primórdios ao cinema contemporâneo (2.ª ed.). Edições 70. Se a cultura é um arquivo aberto, tal assunção pressupõe uma reinterpretação constante daquilo que ...nesse arquivo foi depositado, tanto o que persistiu como o que foi esquecido; mas o facto de ser um arquivo aberto implica também que tanto as permanências como as ausências não sejam definitivas. Por esse motivo, Stuart Hall (2003/2006), por exemplo, considerou que a cultura não era uma arqueolo...
Although widely used in GTAW, GMAW and SMAW processes, the weaving technique in the SAW process still goes nearly unexplored in the literature. In this context, given the scarcity of studies and the ...perceived potential regarding its employment in cladding, groove filling and tempering pass, the present work aimed to investigate the effects of its application in the SAW process with high amplitudes on the morphological aspects of the obtained weld beads. For this purpose, bead-on-plate welding tests with weaving amplitudes of up to 40 mm at different welding energies were performed. As a result, weld beads up to 45 mm width, free of discontinuities and with constant penetration profiles were obtained. However, need was found for a minimum material input of 0.90 g/cm
2
, regardless of the weaving amplitude, in addition to a minimum welding energy to avoid lack of deposition on the weld beads. Furthermore, when considering the ratio between the molten area and the welding energy, progressively higher values were obtained with the increase in the weaving amplitude, which translates into higher melting efficiency indices of the process.
Neste ensaio discutimos as possibilidades da geografia literária. Na constituição dessa abordagem tanto estudiosos da geografia como da literatura pensam nas possíveis relações entre o espaço e a ...palavra escrita. De um lado, o olhar geográfico no entendimento dos textos literários, do outro, a compreensão literária do problema do espaço. Nos dois casos, leituras do espaço que atravessam a literatura. Mas à geografia literária também pode interessar os espaços de leitura, lugares onde a literatura tem papel relevante na concepção de mundo das pessoas que os frequentam. Das leituras do espaço aos espaços de leitura a geografia literária pode ser ampliada, enriquecida, tendo a certeza que a literatura, entre tantas outras artes, tem a capacidade de reeditar a verdade do homem no mundo, de mudar a sua história e a sua geografia.
In everyday life, face similarity is an important kinship clue. Computer algorithms able to infer kinship from pairs of face images could be applied in forensics, image retrieval and annotation, and ...historical studies. So far, little work in this area has been presented, and only one study, using a small set of low quality images, tackles the problem of identifying siblings pairs. The purpose of our paper is to present a comprehensive investigation on this subject, aimed at understanding which are, on the average, the most relevant facial features, how effective can be computer algorithms for detecting siblings pairs, and if they can outperform human evaluation. To avoid problems due to low quality pictures and uncontrolled imaging conditions, as for the heterogeneous datasets collected for previous researches, we prepared a database of high quality pictures of sibling pairs, shot in controlled conditions and including frontal, profile, expressionless, and smiling faces. Then we constructed various classifiers of image pairs using different types of facial data, based on various geometric, textural, and holistic features. The classifiers were first tested separately, and then the most significant facial data, selected with a two stage feature selection algorithm were combined into a unique classifier. The discriminating ability of the automatic classifier combining features of different nature has been found to outperform that of a panel of human raters. We also show the good generalization capabilities of the algorithm by applying the classifier, in a cross-database experiment, to a low quality database of images collected from the Internet.
Gasketed plate heat exchangers are characterized in a usual heat exchanger class. These systems employ elastomeric gaskets as the sealing element. Several conditions lead to oxidation and ...deterioration of these materials and their properties. In addition, the complex geometry of the gaskets and operation conditions may cause divergence in the expected aging behavior of the rubber. In light of this, this study aims to predict the service lifetime for nitrile butadiene rubber gaskets used in plate heat exchangers based on their geometry under thermo‐oxidative aging. These gaskets were evaluated by means of Shore A hardness, compression set (CS), and indentation modulus profile. Through aging‐sealing tests, an end‐of‐life criteria was determined concerning CS measurements and the service lifetime prediction was obtained by time–temperature superposition and WLF method. Diffusion‐limited oxidation effects were observed at high temperatures in postaging analysis and a non‐Arrhenius behavior was observed at 170°C. The value of 79% CS was obtained as end‐of‐life criteria from 60 to 140°C, ranged from 731 to 80 days, respectively, revealing an activation energy equivalent to 32.3 kJ mol−1. These results might support the maintenance planning control of gasketed plate heat exchangers.
A service lifetime prediction based on sealing‐aging experiments for gaskets used in plate heat exchangers was proposed. As result, a 32.3 kJ mol−1 activation energy was obtained concerning thermal‐oxidative aging in a temperature range from 60 to 140°C, which follow 731 and 80 service days for nitrile butadiene rubber gaskets, respectively.
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