The effect of elevated temperatures, particularly between 95 and 115°C as encountered in some geoenvironmental applications, on the physical and mechanical properties of high-density polyethylene (HDPE) geomembranes (GMBs) is examined. Four commercially available HDPE GMBs were incubated in air at temperatures ≥ 85°C. Investigation of the thermograms by differential scanning calorimetry showed a significant change in the polymer morphology with an increase of the incubation temperature and duration, especially at 105 and 115°C. The morphological changes due to annealing involve thickening of the lamella crystals of the polymer and a change in the tie molecules joining the lamella crystals. The effect of annealing was most evident in the stress crack resistance of the GMB incubated at 105 and 115°C prior to polymer degradation. In particular, an increase in stress crack resistance due to annealing could mask the effects of polymer degradation at temperatures above 95°C. Changes in morphology did not affect melt index whose changes were largely attributed to polymer degradation.

PURPOSE: To present a case of dislocated Sömmering ring and a literature review of similar cases with highlights of the similarities and differences between them. METHODS: Case report and literature review. RESULTS: A 65-year-old man presented with sudden appearance of a large white apparent foreign body in his left eye following blunt trauma. The patient underwent cataract surgery without intraocular lens implantation, having had cataract secondary to blunt ocular trauma 53 years ago. Cataract extraction was done under general anesthesia and histopathologic examination was performed. Current literature bodies was reviewed for patients diagnosed as having Sömmering ring. CONCLUSIONS: Patients who underwent cataract surgery with old-fashioned techniques have a possibility of developing unusual complications such as Sömmering ring. In such cases, high myopia is a risk factor for ring dislocation. [ J Refractive Surgery Case Reports. 2022;2(2):e43–e45.]

Introduction The aim of this study was to compare the efficacy of Photo-Activated Chromophore for Keratitis – Corneal Collagen Cross-linking (PACK-CXL) of three different total UVA fluence levels and topical voriconazole in treatment of fungal keratitis experimentally induced in rabbits. Methods This is an interventional experimental study including both eyes of 16 rabbits (32 eyes). Fungal keratitis was induced by intrastromal injection of Fusarium Solani into the cornea. The rabbits were then divided into four groups (8 eyes for each) from which group A received Voriconazole eye drops and considered as control group. Group B, C, D received single PACK-CXL session with total fluence levels of 7.2, 10.0 and 15.0 J/cm2 for each respectively. Daily clinical examination was recorded and all corneas were removed for microbiology and histopathology on day ten. Results The mean clinical signs score eyes treated with high fluence PACK-CXL showed evident clinical improvement from fourth to tenth day of treatment. This improvement was equivalent to that of Voriconazole treatment. The results showed better improvement with increasing the UVA total fluence levels but this difference was not statistically significant (P < 0.05). Similarly, the median CFU/ml declined on increasing UVA fluence but with no statistically significant values. Histopathological examination revealed better improvement of inflammatory signs on higher fluence levels compared to lower ones. Conclusions High intensity PACK-CXL (30 mW/cm2) was as effective as Voriconazole in the treatment of fungal keratitis in rabbits. Increasing the fluence of UVA was associated with slightly better clinical outcomes with no added risks. More clinical studies are needed to confirm these results.

Many structures often carry lateral loads due to earth pressure, wind, earthquakes, wave action and ship impact. The accurate predictions of the load-displacement response of the pile group as well as the straining actions are needed for a safe and economic design. Most research focused on the behavior of laterally loaded single piles though piles are most frequently used in groups. Soil is modeled as an elastic-perfectly plastic model using the Mohr-Coulomb constitutive model. The three-dimensional Plaxis model is validated using load-displacement results from centrifuge tests of laterally loaded piles embedded in sand. This study utilizes three dimensional finite element modeling to better understand the main parameters that affect the response of laterally loaded pile groups (2 • 2 and 3 • 3 pile configurations) including sand relative density, pile spacing (s = 2.5 D, 5 D and 8 D) and pile location within the group. The fixity of the pile head affects its load-displacement under lateral loading. Typically, the pile head may be unrestrained (free) head as the pile head is allowed to rotate, or restrained (fixed) head condition where no pile head rotation is permitted. The analyses were performed for both free and fixed head conditions.

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