Determination of the physical and mechanical properties of recycled gypsum from plasterboards sheets and common gypsum through recycling cycles

The search for technical and economic feasibility of waste recycling in the production chain of construction, come meet the changing industry needs to promote an integrated economic growth to social and environmental needs. In this sense, the objective of this research was to investigate the recycling process of gypsum from the plasterboard sheets and common gypsum residue, on bench scale, and the quality of the materials generated during five cycles of recycling. For this purpose, an equipment was developed to separate the paper and the plaster mass from the gypsum plasterboard sheet residues, as well as for their processing. The experiment covered the grinding, milling, calcination, hydration, formation and rupture of test bodies using gypsum waste. Using MEV and EDS, the microstructure of recycled gypsum was characterized as to its chemical and mineralogical composition. The characteristics of the powder, the physical and mechanical properties in the fresh and hardened states were determined for five proportions of recycled gypsum and the common gypsum throughout the recycling cycles. The samples molded only with recycled gypsum from the gypsum plasterboard sheets met the criteria of the time of picking for plaster of coating, with the beginning of the handle after 10 minutes and the end of the handle after 45 minutes, until the fourth cycle. The results showed that it is possible to reach values of 6.5 to 13.10 MPa of axial compressive strength up to the third recycling cycle. Values above 30 N mm-² for surface hardness were obtained in all samples. The insertion of common gypsum in the molding of the specimens increased the values of the tensile strength in the flexion in the second, fourth and fifth cycles, in relation to the test pieces molded only with recycled plaster. In the first cycle, only the samples that had common gypsum in their composition reached 8.4 MPa for the axial compressive strength. Samples molded with 50% of common gypsum reached 66 N mm-² in the surface hardness test, in the first cycle.The crystalline structure and the interlacing of the recycled gypsum crystals and common gypsum were visualized, concluding that the increase of the tensile strength in the flexion is due to the better interlacing of the crystals and the reduction of voids, since the crystals of common plaster showed to be more elongated, while the plaster of recycled orthorhombic and shorter, thus filling the voids. It was verified the reversibility of the reactions during the recycling cycles, proving the technical feasibility of the process used in this research until the third cycle of recycling.A busca pela viabilidade técnica e econômica da reciclagem de resíduos na cadeia produtiva da construção civil vem atender às necessidades do setor e promover desenvolvimento integrado às necessidades sociais e ambientais. Nesse sentido, esta pesquisa teve como objetivo investigar o processo de reciclagem de resíduos de gesso acartonado e comum, em escala de bancada, e a qualidade dos materiais gerados ao longo de cinco ciclos de reciclagem. Para tanto, foi desenvolvido um equipamento para a separação entre o papel e a massa de gesso dos resíduos de gesso acartonado, assim como para seu beneficiamento. O experimento abrangeu a trituração, moagem, calcinação, hidratação, formação e rompimento de corpos de prova utilizando os resíduos de gesso. Utilizando-se MEV e EDS, caracterizou-se a microestrutura do gesso reciclado quanto à sua composição química e mineralógica. Determinaram-se as características do pó, as propriedades físicas e mecânicas nos estados fresco e endurecido para cinco proporções de gesso reciclado e do gesso comum ao longo dos ciclos de reciclagem. As amostras moldadas somente com gesso reciclado proveniente das chapas de gesso acartonado atenderam os critérios do tempo de pega para gesso de revestimento, com início de pega após 10 minutos e fim de pega após 45 minutos, até o quarto ciclo. Os resultados mostraram que é possível atingir valores de 6,5 à 13,10 MPa de resistência à compressão axial até o terceiro ciclo de reciclagem. Obtiveram-se em todas as amostras valores superiores a 30 N mm-² para a dureza superficial. A inserção de gesso comum na moldagem dos corpos de prova elevou os valores da resistência à tração na flexão nos segundo, quarto e quinto ciclos, em relação aos corpos de prova moldados somente com gesso reciclado. No primeiro ciclo, somente as amostras que possuíam gesso comum em sua composição atingiram os 8,4 MPa para a resistência à compressão axial. Amostras moldadas com 50% de gesso comum atingiram 66 N mm-² no ensaio de dureza superficial, no primeiro ciclo. Visualizaram-se a estrutura cristalina e o entrelaçamento dos cristais de gesso reciclado e gesso comum, concluindo-se que o aumento de resistência à tração na flexão deve-se ao melhor entrelaçamento dos cristais e a redução de vazios, uma vez que os cristais de gesso comum mostraramse mais alongados, enquanto os de gesso reciclados ortorrômbicos e mais curtos, preenchendo assim o vazios. Foi verificada a reversibilidade das reações durante os ciclos de reciclagem, comprovando a viabilidade técnica do processo utilizado nesta pesquisa até o terceiro ciclo de reciclagem

Utilização do bioestimulante Ecolife® na indução de florada em manga (Mangifera indica L.) âTommy Atkinsâ no vale do São Francisco, em Petrolina â PE

A indução de floração em plantas utilizando produtos naturais tem sido uma alternativa viável para minimizar os custos de produção bem como os impactos ambientais causados pela aplicação de produtos químicos. Este trabalho objetivou avaliar a eficácia de Ecolife®, um produto à base de bioflavonóides e fitoalexinas cítricas como indutor de florada na cultura da mangueira (Mangifera indica L.) cv Tommy Atkins. O ensaio foi instalado numa propriedade privada do Perímetro Irrigado Senador Nilo Coelho, N 11, em Petrolina, PE. O delineamento experimental foi casualizado com dois tratamentos: T1 - Ecolife® e T2 - Testemunha absoluta, cinco repetições e cinco plantas por repetição. As pulverizações foram realizadas semanalmente a partir da segunda indução com KNO3 a 4% + Ecolife® 0,75 L ha-1 até a quinta indução, sendo a dosagem do KNO3 reduzida gradativamente até atingir 2%. Realizaram-se avaliações quinze dias após a última aplicação do produto, quantificando-se o número de panículas por quadrante por planta. Submetidos os resultados à análise de variância e teste de Tukey a 5%, concluiu-se que as plantas tratadas com Ecolife® diferiram estatisticamente da Testemunha quanto ao número de panículas. Quantificadas as produtividades médias de cada tratamento obteve-se para T1- 21,61 t ha-1 e T2- 19,63 t ha-1, indicando que Ecolife® apresenta potencial de utilização na indução floral da mangueira. Palavras-chave: Mangifera indica L, indutor biótico, produtividade.</div

CaMK1D signaling in AgRP neurons promotes ghrelin-mediated food intake

Hypothalamic AgRP/NPY neurons are key players in the control of feeding behavior. Ghrelin, a major hormone released under fasting conditions, activates orexigenic AgRP/NPY neurons to stimulate food intake and adiposity. However, cell-autonomous ghrelin-dependent signaling mechanisms in AgRP/NPY neurons remain poorly defined. Here we demonstrate that calcium/calmodulin-dependent protein kinase ID (CaMK1D), a genetic hot spot in type 2 diabetes, is activated in hypothalamus upon ghrelin stimulation and acts in AgRP neurons to promote ghrelin-dependent food intake. Global CaMK1D knockout mice are resistant to the orexigenic action of ghrelin, gain less body weight and are protected against high-fat dietinduced obesity. Deletion of CaMK1D in AgRP but not in POMC neurons is sufficient to recapitulate above phenotypes. Lack of CaMK1D attenuates phosphorylation of CREB and CREB-dependent expression of the orexigenic neuropeptides AgRP/NPY as well as the amount of AgRP fiber projections to the Paraventricular nucleus (PVN), while electrical activity of AgRP neurons and 5' AMP-activated protein kinase (AMPK) signaling are unaffected. Hence, CaMK1D links ghrelin action to transcriptional control of orexigenic neuropeptide availability in AgRP neurons

The REMEDEE Trial A Randomized Comparison of a Combination Sirolimus-Eluting Endothelial Progenitor Cell Capture Stent With a Paclitaxel-Eluting Stent

ObjectivesThis study sought to compare the efficacy and safety results after coronary implantation of a combined sirolimus-eluting CD34 antibody coated Combo stent (OrbusNeich Medical, Ft. Lauderdale, Florida) with the paclitaxel-eluting Taxus Liberté stent (PES) (Boston Scientific, Natick, Massachusetts). This report summarizes the first-in-man randomized, controlled multicenter REMEDEE trial (Randomized study to Evaluate the safety and effectiveness of an abluMinal sirolimus coatED bio-Engineered StEnt) angiographic, intravascular ultrasound, and clinical results up to 12 months.BackgroundDrug-eluting stents have limited restenosis and reintervention but are complicated by especially late and very late stent thrombosis and accelerated neoatherosclerosis. Alternative or adjunct technologies should address these limitations.MethodsOne hundred eighty-three patients with de novo native coronary artery stenoses were randomized 2:1 to Combo stent or PES implantation. The primary endpoint is the angiographic in-stent late lumen loss at 9 months, which was tested for noninferiority between the 2 stent groups. Secondary endpoints include the occurrence of major adverse cardiac events.ResultsThe Combo stent was found to be noninferior to the PES in 9-month angiographic in-stent late lumen loss with 0.39 ± 0.45 mm versus 0.44 ± 0.56 mm (pnoninferiority = 0.0012). At 12 months, the occurrence of major adverse cardiac events was 8.9% in the Combo group and 10.2% in the PES group (p = 0.80) with no difference in mortality, occurrence of myocardial infarction, or target lesion revascularization. No stent thrombosis was reported in either group.ConclusionsIn the REMEDEE trial the Combo stent has shown to be effective by meeting the primary noninferiority angiographic endpoint and safe, with an overall low rate of clinical events in both stent groups, including no stent thrombosis up to 12 months

Genetics and cardiovascular system: influence of human genetic variants on vascular function

Candidate gene association studies in cardiovascular diseases have provided evidence on the molecular basis of phenotypic differences between individuals. The comprehension of how inherited genetic variants are able to affect protein functions has increased the knowledge of how genes interact with environment in order to modulate a particular phenotype. Although it is known that the human genome contains more than 10 million SNPs, only a minor part of them are supposed to be functional. A causative SNP in a particular gene may confer a small to moderate effect in complex phenotypes, such as functions important to cardiovascular homeostasis. This paper is a selective review of the literature on the evidence for interactions between vascular function and naturally occurring genetic variants in endothelial nitric oxide synthase (eNOS) and beta-2 adrenergic receptor (ADRB2), two genes among those influencing vascular phenotype and examples for which there is a strong evidence base. eNOS and ADRB2 will be characterized, as well as the mechanisms by which the enzyme and the receptor work to control vascular responses will be described. Understanding the molecular mechanisms underlying gene-mediated vascular function and their modification by genetic variants is expected to result in a better comprehension about individual’s phenotypic differences