Lightweight carbon foam obtained from post-use polyethylene terephthalate bottles, properties, and potential applications.

The excessive consumption of plastic packaging, especially those produced with polyethylene terephthalate (PET), and the fact that most of them are destined for garbage have made such packaging a worrying environmental liability. Their inadequate disposal promotes the pollution of soils, watercourses, and oceans, and even the presence of component materials of these packages in the human body, in the form of microplastics, has been observed. As research in the area advances, greater concerns arise, as more problems arising from the excessive use and disposal of plastics are identified. Looking for an alternative for the destination of this material, a technology was developed for the production of materials with characteristics similar to 3D graphene. This carbon material has qualities and versatility that allow its wide use in several applications and is produced using PET as a carbon precursor. This work presents this production technology with possible variables, the characterization of the produced materials, and their potential applications. For the electronics area, such as supercapacitors, improvement points needed for validation were observed. For application as an adsorbent and use in the treatment of industrial effluents when using sand covered by carbon material, the results demonstrated efficiency. The material proved to be a potential destination for PET, as an alternative to reduce this environmental liability.

Intraocular pressure and ocular rigidity after LASIK.

PURPOSE: To assess the intraocular pressure (IOP) and ocular rigidity (E) at 1, 3, 6 and 24 postoperative months in eyes that underwent LASIK. METHODS: The IOP measured by Goldmann applanation tonometer (GAT) and by the 5.5 and 10 gm. weights of a standardized Schioetz tonometer (ST) and the E measured by differential tonometry (the 5.5 and 10 gm. of ST) were assessed before and after LASIK (at 1, 3, 6 and 24 month) in 23 eyes. The volume of the corneal indentation (Vc) and IOP with ST resting on the eye (tonometric pressure - Pt) were also evaluated. RESULTS: The average IOP (GAT) at 6 and 24 months after LASIK was lower than at 1 and 3 months and before LASIK. A statistically significant difference of E was found at 1, 3, 6 and 24 months. The reduction of the central corneal thickness (CCT) by LASIK was the cause of increasing values of Vc and decreased values of Pt. In turn, the changes in Vc and Pt were responsible for the lower IOP measurements by GAT and E changes. CONCLUSIONS: LASIK reduces IOP readings by GAT but not the ones by ST (differential tonometry). LASIK also diminishes E. IOP (GAT) values are lower at 6 and 24 months. IOP evaluation by ST is more accurate than that by GAT. At 6 months, Vc, Pt and E parameters are stabilized (no changes relatively to 24 months measurements.

Intraocular pressure and ocular rigidity after LASIK / Pressão intraocular e rigidez ocular após LASIK

PURPOSE: To assess the intraocular pressure (IOP) and ocular rigidity (E) at 1, 3, 6 and 24 postoperative months in eyes that underwent LASIK. METHODS: The IOP measured by Goldmann applanation tonometer (GAT) and by the 5.5 and 10 gm. weights of a standardized Schioetz tonometer (ST) and the E measured by differential tonometry (the 5.5 and 10 gm. of ST) were assessed before and after LASIK (at 1, 3, 6 and 24 month) in 23 eyes. The volume of the corneal indentation (Vc) and IOP with ST resting on the eye (tonometric pressure - Pt) were also evaluated. RESULTS: The average IOP (GAT) at 6 and 24 months after LASIK was lower than at 1 and 3 months and before LASIK. A statistically significant difference of E was found at 1, 3, 6 and 24 months. The reduction of the central corneal thickness (CCT) by LASIK was the cause of increasing values of Vc and decreased values of Pt. In turn, the changes in Vc and Pt were responsible for the lower IOP measurements by GAT and E changes. CONCLUSIONS: LASIK reduces IOP readings by GAT but not the ones by ST (differential tonometry). LASIK also diminishes E. IOP (GAT) values are lower at 6 and 24 months. IOP evaluation by ST is more accurate than that by GAT. At 6 months, Vc, Pt and E parameters are stabilized (no changes relatively to 24 months measurements.

OBJETIVO: Avaliar comparativamente a pressão intraocular (Po) e a rigidez ocular (E) antes e após 1, 3, 6 e 24 meses em olhos submetidos a LASIK. MÉTODOS: Foram avaliados a Po (pela tonometria de aplanação de Goldmann - TAG e pela tonometria diferencial com os pesos 5,5 e 10 g do tonômetro de Schioetz (ST) e E (pela tonometria diferencial) antes e após 1, 3, 6 e 24 meses em 23 olhos submetidos a LASIK. Foram também avaliados o volume de depressão corneana (Vc) e a pressão tonométrica (Pt) com o tonômetro de Schioetz repousando sobre o olho. RESULTADOS: Os valores médios da Po (TAG) 6 e 24 meses após o LASIK foram menores que os obtidos antes e 1 e 3 meses após o LASIK. Os valores médios de E foram significativamente inferiores após 1, 3, 6 e 24 meses após o LASIK que antes da cirurgia. A redução da espessura central da córnea pelo LASIK causou aumento dos valores médios de Vc e diminuição dos de Pt. Por sua vez, essas alterações de Vc e Pt foram as responsáveis pelos menores valores das medidas de Po (TAG) e de E. CONCLUSÕES: A cirurgia por LASIK diminui os valores da leitura da Po medida pelo tonômetro de Goldmann, porém não altera os valores de Po obtidos pela tonometria de Schioetz. A cirurgia também diminui a rigidez ocular. As medidas da Po (TAG) apresentaram menores valores 6 e 24 meses após o Lasik. A avaliação da Po pelo ST parece ser mais confiável que pelo TAG. Observou-se estabilização dos valores de Vc, Pt and E seis meses após o LASIK.

Estudo comparativo entre a tonometria de näo contato com o tonômetro pulsair e a tonometria de aplanaçäo de Goldmann / Comparative study between non-contact tonometry with pulsair tonometer and Goldmann applanation tonometry

O estudo comparativo entre os tonômetros de aplanaçäo de Goldmann e o Pulsair realizado em 564 olhos de 295 pacientes repartidos em 3 grupos, mostrou grande variaçäo nas medidas individuais, mais acentuadas na faixa de Po de 30 a 50 mmHg (tonômetro de aplanaçäo de Goldmann tomado como padräo). Até 25 e 30 mmHg, o Pulsair deu valores mais elevados em relaçäo ao tonômetro de Goldmann. Acima de 30 mmHg do tonômetro de Goldmann, o Pulsair deu valores mais baixos. A anestesia tópica näo modificou significamente as tonometrias com o Pulsair (grupos I e II) em relaçäo à tonometria sem anestesia tópica (grupo III) com o mesmo tonômetro. O estudo estatístico com o test "t" para amostras pareadas mostrou grandes diferenças entre os dois instrumentos e a correlaçäo linear entre eles também näo foi adequada (r=0,74, 0,60 e 0,84 para os grupos I, II e III respectivamente)