RESUMO
An increasing number of studies focus on organic flow batteries (OFBs) as possible substitutes for the vanadium flow battery (VFB), featuring anthraquinone derivatives, such as anthraquinone-2,7-disulfonic acid (2,7-AQDS). VFBs have been postulated as a promising energy storage technology. However, the fluctuating cost of vanadium minerals and risky supply chains have hampered their implementation, while OFBs could be prepared from renewable raw materials. A critical component of flow batteries is the electrode material, which can determine the power density and energy efficiency. Yet, and in contrast to VFBs, studies on electrodes tailored for OFBs are scarce. Hence, in this work, we propose the modification of commercial carbon felts with reduced graphene oxide (rGO) and poly(ethylene glycol) for the 2,7-AQDS redox couple and to preliminarily assess its effects on the efficiency of a 2,7-AQDS/ferrocyanide flow battery. Results are compared to those of a VFB to evaluate if the benefits of the modification are transferable to OFBs. The modification of carbon felts with surface oxygen groups introduced by the presence of rGO enhanced both its hydrophilicity and surface area, favoring the catalytic activity toward VFB and OFB reactions. The results are promising, given the improved behavior of the modified electrodes. Parallels are established between the electrodes of both FB technologies.
RESUMO
Fire resistance recycled blocks, containing fly ash and bottom ash from coal combustion power plants with a high fire resistance, are studied in this paper by testing different compositions using Portland cement type II, sand, coarse aggregate and fly ash (up to 50% of total weight) and bottom ash (up to 30% of total weight). The fire resistance, physical-chemical (density, pH, humidity, and water absorption capacity), mechanical (compressive and flexural strength), and leaching properties are measured on blocks made with different proportions of fly ash and bottom ash. The standard fire resistance test is reproduced on 28cm-high, 18cm-wide and 3cm-thick units, and is measured as the time needed to reach a temperature of 180°C on the non-exposed surface of the blocks for the different compositions. The results show that the replacement of fine aggregate with fly ash and of coarse aggregate with bottom ash have a remarkable influence on fire resistance and cause no detriment to the mechanical properties of the product. Additionally, according to the leaching tests, no environmental problems have been detected in the product. These results lead to an analysis of the recycling possibilities of these by-products in useful construction applications for the passive protection against fire.
Assuntos
Cinza de Carvão/química , Carvão Mineral , Materiais de Construção , Incêndios/prevenção & controle , Reciclagem/métodosRESUMO
INTRODUCTION: Bladder sarcomatoid carcinoma is a very rare variant of transitional cell carcinoma. With disputed nomenclature, the tumor has been described previously under a variety of names such as sarcomatoid carcinoma, pseudosarcoma, malignant mixed mesodermal/Müllerian tumor, metaplastic carcinoma and spindle cell carcinoma. This malignancy represents 0.3% of all bladder tumors and has an aggressive behavior yielding a poor prognosis despite radio and chemotherapy. CASE REPORT: An 81 y/o man presented with a transitional cell carcinoma and underwent a transurethral resection. Adjuvant onco-BCG was introduced. After 9 months of follow-up, a local tumoral recurrence occurred and a new transurethral resection revealed sarcomatoid carcinoma with osseous elements. A radical cystoprostatectomy was then carried out.
Assuntos
Carcinoma de Células de Transição/patologia , Neoplasias da Bexiga Urinária/patologia , Adjuvantes Imunológicos/uso terapêutico , Idoso de 80 Anos ou mais , Vacina BCG/uso terapêutico , Carcinoma de Células de Transição/tratamento farmacológico , Carcinoma de Células de Transição/cirurgia , Cistectomia , Evolução Fatal , Seguimentos , Humanos , Masculino , Recidiva Local de Neoplasia/cirurgia , Prostatectomia , Neoplasias da Bexiga Urinária/tratamento farmacológico , Neoplasias da Bexiga Urinária/cirurgiaRESUMO
INTRODUCTION: Bladder sarcomatoid carcinoma is a very rare variant of transitional cell carcinoma. With disputed nomenclature, the tumor has been described previously under a variety of names such as sarcomatoid carcinoma, pseudosarcoma, malignant mixed mesodermal/Müllerian tumor, metaplastic carcinoma and spindle cell carcinoma. This malignancy represents 0.3 percent of all bladder tumors and has an aggressive behavior yielding a poor prognosis despite radio and chemotherapy. CASE REPORT: An 81 y/o man presented with a transitional cell carcinoma and underwent a transurethral resection. Adjuvant onco-BCG was introduced. After 9 months of follow-up, a local tumoral recurrence occurred and a new transurethral resection revealed sarcomatoid carcinoma with osseous elements. A radical cystoprostatectomy was then carried out.