Abstract Lemongrass (Cymbopogon citratus) is an aromatic plant of great significance in industries due to its essential oil characteristic aroma. Essential oils are concentrated plant extracts that evaporate when in contact with air and have low chemical stability, which can improve encapsulation techniques. This study aimed to evaluate the seasonal influence in the concentration of the predominant component citral of the essential oil of C. citratus and develop microparticles by spray drying containing this vegetal matrix. The lemongrass leaves were collected in the four seasons, and the essential oil was extracted by hydrodistillation. The chemical composition was determined by gas chromatography coupled with the mass spectrometry technique (GC-MS). Different proportions of arabic and guar gums were evaluated as encapsulating agents. Physicochemical analyses characterized the microparticle powder. GC-MS showed higher citral in the spring and summer (84.89% and 79.39%, respectively), and it was possible to identify a high amount of citral in the microparticles. Field-emission scanning electron microscopy showed agglomerate and collapsed microparticles. Fourier transform infrared spectroscopy suggested the essential oil encapsulation due to a band at 1675 cm-1 used as a reference, related to the acyclic monoterpenes of citral. X-ray diffraction showed the amorphous structure of the microparticles. Thermogravimetric curves of microparticles showed higher Tonset in microparticles than those observed for pure lemongrass essential oil, inferring that microencapsulation improved the thermal stability. This result confirms the lemongrass essential oil microencapsulation and its potential application in food products, drugs, or cosmetics.

ABSTRACT Furrowing shank horizontal strength and working depth can be correlated with soil compaction in a no-till sowing. This study aimed to evaluate the correlation of furrowing shank strength and working depth with soil physical properties at two working speeds (1.58 and 1.87 m s-1) and four compaction levels induced by an agricultural tractor (0P, 1P, 3P, and 5P+Ballast), with four repetitions in an RBD. Thereby, we aimed to verify a potential increase in sampling density of soil compaction data. Horizontal strength at 1.58 m s-1 had Pearson correlations ranging from 0.74 to 0.73 with soil penetration resistance (SPR), and from 0.57 to 0.72 with some soil properties collected by volumetric ring. Working depth also correlated with several parameters ranging from 0.49 to 0.81. The highest correlations were verified for the speed of 1.58 m s-1, at which shanks maintained greater depth. This increased soil contact with the shank, hence sensitivity to compaction. Our findings show that furrowing shank horizontal strength and working depth can be used to monitor soil compaction.

ABSTRACT The increment of recycling of steel using electric arc furnace and the tendency to coat of steel products with zinc, in order to prevent corrosion, has increased the proportion of galvanized scrap used worldwide in the recent years. Approximately 10 to 20 Kg/t of cast steel is generated in casting arcs. These collected dusts electric arc furnace (EAF dust) contains iron, zinc, lead, and cadmium. Mainly in the form of oxides and their wastes are considered hazardous typically in countries such as Brazil, U.S., Japan and Germany. It is estimated that from the total of 7.5 million metric tons of EAF dust generated worldwide only 45% is recycled. With Waelz process, the EAF dust can be treated to recover zinc by means of reduction-volatilization-oxidation reactions occurring within the rotary kiln. In this work the thermodynamics of the Waelz process is studied to optimize the recovery of volatiles especially zinc. Kinetic parameters were evaluated trough series of ten experiments, comprise the major process factors such as type of reductants (charcoal and petroleum coke), time (20 – 120 minutes) and temperature (450 - 1150°C). The mechanical behavior of the pellets was evaluated by compressive cold strength and drop tests. Characterization was performed using scanning electron microscopy, microanalysis EDS, X-ray diffraction, X-ray fluorescence, granulometric analysis by laser diffraction, as well as measurements of moisture, bulk density and percentage of volatiles, fixed carbon and ash. The small pellets (10mm) with charcoal used as a reductant, presented a higher compression and higher recovery of volatiles than those with petroleum coke.

RESUMOProstitutas têm sido protagonistas e foco de campanhas de prevenção de HIV desde o final da década de 1980 no Brasil. Com base em um levantamento da literatura nacional e internacional, combinada com a trajetória do movimento de prostitutas na construção da resposta brasileira à epidemia, este artigo explora as sobreposições e incoerências entre pesquisa e prática em contextos de prostituição nas últimas três décadas. Na revisão da literatura científica, verificamos que a maior vulnerabilidade desse grupo social ocorre com os parceiros íntimos, não-comerciais; entretanto, o foco das pesquisas e a forma que são feitas geralmente reforçam a ideia de que a vulnerabilidade decorre de seus clientes. Ao mesmo tempo, há poucos estudos sobre seus contextos de trabalho e fatores estruturais que influenciam práticas sexuais mais seguras com ambos os tipos de parceiros. Os efeitos negativos da criminalização, do estigma, e de abordagens exclusivamente biomédicas e baseadas de uma forma isolada na metodologia de educação pelos pares estão bem documentados na literatura científica e nas experiências de ativistas, assim como a importância de programas de prevenção baseados em direitos humanos e sexuais. Concluímos que há necessidade de ações, políticas e pesquisas que incluam o ambiente e contexto nos quais profissionais do sexo trabalham, que reincorporem o arcabouço de direitos humanos e cidadania que dominou a resposta brasileira até o final da década de 2000, e que prostitutas devem ser consideradas e tratadas como mulheres, iguais a todas as outras.

ABSTRACTSex workers have been the protagonists and focus of HIV prevention campaigns and research since the late 1980s in Brazil. Through a review of national and international literature, combined with a history of sex workers' involvement in the construction of the Brazilian response, this article explores the overlaps and disconnects between research and practice in contexts of prostitution over the past three decades. We review the scientific literature on the epidemiology of HIV among sex workers and prevention methodologies. We conclude that although research focus and designs often reinforce the idea that sex workers' vulnerability is due to their sexual relationships with clients, their greatest vulnerability has been found to be with their nonpaying intimate partners. Few studies explore their work contexts and structural factors that influence safe sex practices with both types of partners. The negative effects of criminalization, stigma, and exclusively biomedical and peer education-based approaches are well documented in the scientific literature and experiences of sex worker activists, as is the importance of prevention programs that combine empowerment and human rightsbased approach to reduce HIV infection rates. We conclude that there is a need for actions, policies, and research that encompass the environment and context of sex workers' lives and reincorporate the human rights and citizenship frame that dominated the Brazilian response until the end of the 2000s. As part of HIV prevention efforts, female sex workers need to be considered above all as women, equal to all others.

RESUMO Prostitutas têm sido protagonistas e foco de campanhas de prevenção de HIV desde o final da década de 1980 no Brasil. Com base em um levantamento da literatura nacional e internacional, combinada com a trajetória do movimento de prostitutas na construção da resposta brasileira à epidemia, este artigo explora as sobreposições e incoerências entre pesquisa e prática em contextos de prostituição nas últimas três décadas. Na revisão da literatura científica, verificamos que a maior vulnerabilidade desse grupo social ocorre com os parceiros íntimos, não-comerciais; entretanto, o foco das pesquisas e a forma que são feitas geralmente reforçam a ideia de que a vulnerabilidade decorre de seus clientes. Ao mesmo tempo, há poucos estudos sobre seus contextos de trabalho e fatores estruturais que influenciam práticas sexuais mais seguras com ambos os tipos de parceiros. Os efeitos negativos da criminalização, do estigma, e de abordagens exclusivamente biomédicas e baseadas de uma forma isolada na metodologia de educação pelos pares estão bem documentados na literatura científica e nas experiências de ativistas, assim como a importância de programas de prevenção baseados em direitos humanos e sexuais. Concluímos que há necessidade de ações, políticas e pesquisas que incluam o ambiente e contexto nos quais profissionais do sexo trabalham, que reincorporem o arcabouço de direitos humanos e cidadania que dominou a resposta brasileira até o final da década de 2000, e que prostitutas devem ser consideradas e tratadas como mulheres, iguais a todas as outras.

ABSTRACT Sex workers have been the protagonists and focus of HIV prevention campaigns and research since the late 1980s in Brazil. Through a review of national and international literature, combined with a history of sex workers' involvement in the construction of the Brazilian response, this article explores the overlaps and disconnects between research and practice in contexts of prostitution over the past three decades. We review the scientific literature on the epidemiology of HIV among sex workers and prevention methodologies. We conclude that although research focus and designs often reinforce the idea that sex workers' vulnerability is due to their sexual relationships with clients, their greatest vulnerability has been found to be with their nonpaying intimate partners. Few studies explore their work contexts and structural factors that influence safe sex practices with both types of partners. The negative effects of criminalization, stigma, and exclusively biomedical and peer education-based approaches are well documented in the scientific literature and experiences of sex worker activists, as is the importance of prevention programs that combine empowerment and human rightsbased approach to reduce HIV infection rates. We conclude that there is a need for actions, policies, and research that encompass the environment and context of sex workers' lives and reincorporate the human rights and citizenship frame that dominated the Brazilian response until the end of the 2000s. As part of HIV prevention efforts, female sex workers need to be considered above all as women, equal to all others.