Cement equivalence factor evaluations for fluid catalytic cracking catalyst residue

Fluid catalytic cracking catalyst residue (FC3R) is a waste material that can be used as a Portland cement replacement in pastes, mortars, and concrete. The flow table results show that FC3R is a water demanding addition; nevertheless, this effect can be compensated with the use of superplasticizers. The pozzolanic activity of FC3R was studied observing the mechanical strength evolution with time. Pastes and mortars with FC3R incorporated show higher mechanical strengths than control specimens, indicating the pozzolanic activity of the waste. Cement equivalence factor (k-factor) evaluations were carried out. The k-factor values for the FC3R pastes and mortars were always greater than one, indicating that in order to maintain the same compressive mechanical strength of the control specimen it is sufficient to replace cement with a smaller amount of catalyst residue, due to the high pozzolanic activity of FC3R. There is a strong agreement between the k-factor values obtained in pastes and mortars.This work was supported by Ministerio de Ciencia y Tecnologia, Spain (Project MAT 2001-2694).Paya Bernabeu, JJ.; Monzó Balbuena, JM.; Borrachero Rosado, MV.; Velazquez Rodriguez, S. (2013). Cement equivalence factor evaluations for fluid catalytic cracking catalyst residue. Cement and Concrete Composites. 39:12-17. https://doi.org/10.1016/j.cemconcomp.2013.03.011S12173

Fatal stroke after completion pneumonectomy for torsion of left upper lobe following left lower lobectomy

BACKGROUND: The lobar torsion after lung surgery is a rare complication with an incidence of 0.09 to 0.4 %. It may occur after twisting of the bronchovascular pedicle of the remaining lobe after lobectomy, usually on the right side. The 180-degree rotation of the pedicle produces an acute obstruction of the lobar bronchus (atelectasis) and of the lobar vessels as well. Without prompt treatment it progresses to lobar ischemia, pulmonary infarction and finally fatal gangrene. CASE PRESENTATION: A 62 years old female patient was admitted for surgical treatment of lung cancer. She underwent elective left lower lobectomy for squamous cell carcinoma (pT2 N0). The operation was unremarkable, and the patient was extubated in the operating room. After eight hours the patient established decrease of pO(2 )and chest x-ray showed atelectasis of the lower lobe. To establish diagnosis, bronchoscopy was performed, demonstrating obstructed left lobar bronchus. The patient was re-intubated, and admitted to the operating room where reopening of the thoracotomy was performed. Lobar torsion was diagnosed, with the diaphragmatic surface of the upper lobe facing in an anterosuperior orientation. A completion pneumonectomy was performed. At the end of the procedure the patient developed a right pupil dilatation, presumably due to a cerebral embolism. A subsequent brain angio-CT scan established the diagnosis. She died at the intensive care unit 26 days later. CONCLUSION: The thoracic surgeon should suspect this rare early postoperative complication after any thoracic operation in every patient with atelectasis of the neighboring lobe. High index of suspicion and prompt diagnosis may prevent catastrophic consequences, such as, infarction or gangrene of the pulmonary lobe. During thoracic operations, especially whenever the lung or lobe hilum is full mobilized, fixation of the remaining lobe may prevent this life threatening complication