Chemical Recycling of Polystyrene Using Pyrolysis

There are significant economic and environmental benefits to the recycling of waste plastics, especially that of polystyrene. Currently, much of polystyrene waste is sent to landfills due to the difficulty in separation and cleaning processes, where it accumulates indefinitely. It contributes to plastic pollution and adversely affects wildlife, oceans and humans. Pyrolysis of waste polystyrene is explored in this paper as a chemical recycling method. This reaction yields useful liquid fuel products such as styrene, ethylbenzene, toluene, and methylstyrene, which can be sold to provide project revenues. Beginning with a polystyrene feed of 100 tons per day, the suggested design achieves a liquid styrene product purity of 99.9%. The plant includes a rotary- kiln reactor to carry out the pyrolysis reaction and a distillation train to isolate the liquid products. Pumps, blowers and storage equipment are also included in the design. Heat and energy are optimally integrated using heat exchangers to reduce the cost of purchased utilities. The suggested design requires a capital investment of $25.0 MM and yields a fifteen-year net present value of$5.1 MM. The internal rate of return it achieves is equal to 18.5%. The projected cash flows of this plant suggest that it will break even by 2030 on a cumulative discounted free cash flow basis. The design is recommended based on project specifications and current price projections, though investors should exercise caution with regards to the effect of realistic market prices of styrene and polystyrene on the project’s profitability measures

Margalefidinium polykrikoides Cyst Resuspension in the Lafayette River, a Sub-tributary of the Chesapeake Bay

Harmful Algal Blooms are a collection of algae in a body of water that can cause serious environmental issues and health problems in both people and aquatic organisms. Dinoflagellates are microscopic, unicellular, and eukaryotic organisms that are well known for forming harmful algal blooms because of eutrophication. Coastal Virginia suffers from HABs in the Chesapeake Bay and its tributaries. A common species of dinoflagellate, known as Margalefidinium polykrikoides exists in the Chesapeake Bay. The purpose of this study is to determine if sediment resuspension produced by wind generated surface gravity waves cause cysts (dinoflagellate resting stages) to be suspended into the water column, which could contribute to bloom initiation if they germinate and then inoculate the water column with motile cells. Using light microscopy and qPCR, we will determine the percentage of resuspended dinoflagellate cysts being identified as Margalefidinium polykrikoides

Adaptação para o português do teste de habilidades pragmáticas de Shulman

RESUMO Objetivo A proposta do presente estudo foi aplicar o Test of Pragmatic Skills em crianças brasileiras com desenvolvimento típico. Método Foram participantes desta pesquisa 60 crianças de 3:00 a 8:11 anos, divididas igualmente entre os gêneros. As examinadoras tiveram contato prévio com o grupo de crianças e aplicaram o TOPS – um teste tradicional composto por quatro conjuntos de atividades simples, com material comum, aplicáveis em um curto período de tempo – segundo o proposto pelo autor. Resultados Nos resultados, observamos bastante variabilidade no desempenho, exemplificando que as habilidades linguísticas e pragmáticas vão se desenvolvendo de acordo com a idade. Foi possível observar, ainda, que os participantes apresentaram as categorias de intenções comunicativas pretendidas por Shulman, indicando que não é a presença ou ausência de alguma intenção específica que influencia a pontuação nesse teste, mas a qualidade das respostas fornecidas, que evolui com a idade. Conclusão Desta forma, podemos concluir que o TOPS mostrou-se importante por permitir respostas em contextos informais de conversação, verificando-se que o teste é eficaz para avaliar as habilidades pragmáticas de crianças de desenvolvimento típico e pode ser um instrumento relevante a ser empregado na avaliação das intenções comunicativas de crianças brasileiras