Hydrogen and Carbon Nanotubes from Pyrolysis-Catalysis of Waste Plastics: A Review

More than 27 million tonnes of waste plastics are generated in Europe each year representing a considerable potential resource. There has been extensive research into the production of liquid fuels and aromatic chemicals from pyrolysis-catalysis of waste plastics. However, there is less work on the production of hydrogen from waste plastics via pyrolysis coupled with catalytic steam reforming. In this paper, the different reactor designs used for hydrogen production from waste plastics are considered and the influence of different catalysts and process parameters on the yield of hydrogen from different types of waste plastics are reviewed. Waste plastics have also been investigated as a source of hydrocarbons for the generation of carbon nanotubes via the chemical vapour deposition route. The influences on the yield and quality of carbon nanotubes derived from waste plastics are reviewed in relation to the reactor designs used for production, catalyst type used for carbon nanotube growth and the influence of operational parameters

Infant malnutrition, development rate and its relation to the environment: a pilot study Desnutrición infantil, coeficiente de desarrollo y su relación con el medio ambiente: un estudio piloto.

The socio-cultural factors that might be influencing the normal psychomotor development of the undernourished infant are studied. The sample consisted of 32 mother-infant dyads: 16 having normal DQ (Group A) and 16 having a below normal DQ (Group B) according to Bailey's Test applied to infants who entered a Nutritional Recuperation Center. Results showed that there were some differences in the infants' backgrounds: infants of Group A were the product of a wished-for pregnancy (p less than .05), and were separated less from their mother's side (p less than .007) than was the case in Group B. No differences were found in the socio-cultural and demographic background of the mothers. The infants' external environment was different in aspects observed within the neighborhood: there were fewer negative aspects in Group A than in Group B (p less than .003) and more positive in Group A than in B (p less than .001). The infant's internal environment as related to the mother was also different

Agreement of Corneal Diameter and Anterior Chamber Depth Measurements with the IOLMaster 500 and the IOLMaster 700 Optical Biometers in Myopic Eyes

Pedro Tañá-Rivero, Cristina Tello-Elordi, Paz Orts-Vila, Pedro Tañá-Sanz, Santiago Tañá-Sanz Cataract Department, Oftalvist Alicante, Alicante, SpainCorrespondence: Pedro Tañá-Rivero, Cataract Department, Oftalvist Alicante, C/ Angel Lozano n° 11, Alicante, 03001, Spain, Tel +34 965 141 500, Email [email protected]: To assess the agreement in automated corneal diameter (CD) and anterior chamber depth (ACD, measured from corneal epithelium to lens) distances measurements between the IOLMaster 500 and 700 optical biometers in myopic eyes.Methods: One hundred and sixteen eyes of 116 myopic patients aged between 21 to 60 years were included in this study. Measurements of CD and ACD distances were taken with each biometer for all patients in the same session. A t-test and a p-value less than 0.05 was considered statistically significant when the measurements were compared. The agreement between biometers was studied by applying a Bland–Altman analysis.Results: The mean CD values obtained using the IOLMaster 500 and 700 biometers were 12.26± 0.35 mm and 12.13± 0.34 mm, respectively. The mean ACD distance values were 3.61± 0.29 mm and 3.62± 0.31, for the IOLMaster 500 and 700 biometers, respectively. There were statistically significant differences between the two devices only for CD measurements (p< 0.001), but not for ACD measurements (p=0.26). The limits of agreement obtained were wide in both types of measurements, being 0.422 mm for the CD distance and 0.389 mm for the ACD distance.Conclusion: There were statistically significant differences between the IOLMaster 500 and 700 biometers regarding CD but not in ACD measurements in healthy myopic eyes. These differences could be clinically significant in some cases. According to these results, medical judgement should be used to assess whether the two devices could be used interchangeably for CD and ACD measurements during the clinical practice.Keywords: anterior chamber depth, white-to-white, IOLMaster 500, IOLMaster 700, optical biometr

Pyrolysis of low-density polyethylene

Pyrolysis of low-density polyethylene in an innovative batch pilot plant, with a hydraulic guard ensuring a safe process, was performed. The influence of process temperature on yield, distribution and composition of products was investigated. The oil/waxes were analyzed by gas chromatography coupled mass spectrometry, while pyrolysis gas was monitored online during the process by micro-gas chromatography. Pyrolysis were carried out at 450, 500, 550 and 600 \ub0C. Results obtained show that low temperatures yield a greater amount of oil/waxes, and a gas enriched in carbon oxides and C3+ hydrocarbons. At higher temperatures, the gas fraction, riche in methane and hydrogen, is predominant over liquid products. This process has proved to be a versatile way to recover polyethylene wastes into valuable oils (rich in aliphatic and simple aromatic hydrocarbons) or gas, to be used as petrochemical feedstock or fuel, thus providing a sustainable method for material and energy recovery of waste packaging