Solvay (Brazil)

Abstract Introduction In a chemical industry, where 700 employees and 500 contractors work, after the declaration of a Public Health Emergency of International Concern by WHO on January 30, 2020, a Pandemic Planning Guidance was implemented to manage the issue. Methods and Résults The study consisted of raising the actions were developed during the Covid-19 Pandemic. Discussion From March 2020 to May 2023, an array of actions were taken to prevent the transmission of Covid-19, to properly treat patients and to guarantee the continuity of the plant’s operation: formation of a management group in line with WHO guidelines and the Pandemic Planning Guidance of the business group; allocation of most administrative employees to a HO; online meetings; adjustments to employees transport and the restaurant; implementation of controls for truck drivers and for technical visits; a communication system for employees and third parties about respiratory symptoms; mandatory use of appropriate masks throughout the working day; hand hygiene; physical distancing; 2372 tests were performed on respiratory symptoms before going to work and 19.5% were positive; 8 people were hospitalized and, 1 died before the vaccine campaign; 100% of employees and third parties were fully vaccinated. None of the cases contracted the disease while working. As result of the actions, the plant did not stop its operation any day during the pandemic. Discussion and Conclusion Crisis management during the Covid-19 pandemic was very successful, as it involved everyone’s commitment and prevented the spread of the disease among employees and third parties, as well as avoiding the stoppage of the site’s industrial activities.

Silicon carbide is a unique material produced by the Acheson process, obtaining two main grades: crystal and metallurgical. SIKA ® MET, the metallurgical silicon carbide, has gained prominence for steel sectors due to its unique properties, being used as agent for deoxidation and exothermic purposes in steelmaking routes. It has been presented as an alternative to the FeSi75 usage. FeSi75HP and SIKA ® MET were agents added to the bath at 298K and the hot metal was at 1873K. The FactSage ® simulation studied the deoxidizing effect varying the agent quantity until 10kg added to the bath. The Thermo-Calc ® simulation studied the exothermic effect in a fixed proportion of 3kg of agent per ton of steel, using TCOX10 database and EERZ for a kinetic approximation in a ladle. The deoxidation effect between both agents were similar after 3kg of addition. The exothermic effect obtained a small temperature difference of approximately 10 °C between them, associated to the effect of interaction coefficients of Si or heat generation from carbon content. Due to the similarity of deoxidizing and exothermic properties between both agents and high prices usually obtained for FeSi75, silicon carbide could be considered a cost saving agent to be used for steelmaking routes.

The removal of four pharmaceuticals and personal care products (PPCPs), namely diethyltoluamide (DEET), paracetamol (PAR), caffeine (CAF) and triclosan (TCS) (at a spiked concentration of 25 μg/L), from natural water using the photo (UVC)-Fenton (powdered zero-valent iron, pZVI) process was investigated. The results show that a molar ratio of H2O2/pZVI of 2.0, pZVI concentration of 22.4 mg/L and pH of 3.0 maximised the removal of the target compounds at 71.1%, 100%, 64.2% and 87.1%, for DEET, PAR, CAF and TCS, respectively, after 30 min in Fenton (pZVI) process. When this process was coupled with UVC radiation, 29.6%, 80.3%, 3.1% and 88.4% of DEET, PAR, CAF and TCS, respectively, were removed within the first minute, and 99.0%, 100%, 99.5% and 100%, respectively, were removed after 30 min. The pseudo first-order kinetic model best fitted the degradation data of DEET, PAR and CAF (1–20 min); and because 80% of TCS and PAR degraded within the first minutes, it is suggested to explore the kinetics during the initial period. Characterisations of pZVI after the photo-Fenton (pZVI) process indicated the corrosion of the surface of iron powder and the presence of iron oxides and iron hydroxides. Lower removals of nitrate (35–50%), phosphate (<35%) and total organic carbon (TOC, <18%) were observed, which may be attributed to the small H2O2/pZVI dosage used. Results of this investigation show that the photo-Fenton (pZVI) process has potential for efficient and cost-effective removal of PPCPs.

To assess the bioequivalence of two zolpidem hemitartrate formulations in 30 healthy volunteers. Plasma samples were obtained over a 24 h period. Plasma concentrations of zolpidem were analyzed by liquid chromatography coupled to tandem mass spectrometry with positive ion electrospray ionization using multiple reaction monitoring. Values of peak concentration (Cmax ), area under curve (AUC), half-life, elimination constant, volume of distribution and clearance showed statistically significant differences when comparing women (604.34 ng h/ml, 127.36 ng/ml, 4.4 h, 0.18 1/h, 50.56 L and 8.55 L/h, respectively) and men (276.1 ng h/ml, 70.9 ng/ml, 3.3 h, 0.26 1/h, 91.42 L and 24.34 L/h, respectively), receiving the same dose (5 mg), respectively. The geometric means with corresponding 90% confidence interval for Test/Reference percentage ratios were 99.73% (CI 93.69-106.16) for Cmax, 97.44% (90% CI = 91.85-103.37%) for area under curve of plasma concentration until the last concentration observed (AUClast ) and 98.30% (90% CI = 92.48-104.49) for the area under curve between the first sample (pre-dosage) and infinity (AUC0-inf ). Since the 90% CI for AUClast , AUC0-inf and Cmax ratios were within the 80-125% interval proposed by the US Food and Drug Administration, it was concluded that zolpidem hemitartrate formulation (5 mg orodispersible tablet) is bioequivalent to the zolpidem hemitartrate formulation (Patz SL 5 mg sublingual tablet) with regard to both the rate and the extent of absorption. A new formulation of zolpidem 2.5 mg may be useful in women for the same clinical benefits as the 5 mg formulation in men.

This article evaluates the effects of molecular on rigid PVC mechanical properties. The subject is introduced and associated to application of Oriented PVC in piping systems, regarding the importance of gelation level on the quality of these products. A mono-axial orientation method is described and tested on an extruded sample, whose efficiency is evaluated and samples are produced with different stretching ratios. Upon increasing the stretching ratio, improvements are observed mainly in the maximum tensile strength, tensile modulus and toughness. On the other hand, deformation at break is decreased.

Institut National de la Recherche Scientifique. Montreal, Canadá.