The effect of phenylephrine hydrochloride 2.5 % and sodium hyaluronate solution on visual functions and accommodation in children with myopia and its local tolerability

Purpose: to evaluate visual functions, accommodation, and local tolerance in children instilled with Phenylephrine hydrochloride 2.5 % and sodium hyaluronate solution (Stelphrin Supra). Material and methods. 30 children (60 eyes) aged 8 to 12 (ave. 10.04 ± 0.24) with low (28 eyes) and moderate (32 eyes) myopia (ave. -2.96 ± 0.17 D) were tested. Refractometry, subjective and objective accommodation, optical biometry, anterior corneal surface examination, Norn test, and polling were performed prior to one-time instillation, 30 minutes after it, and after 1 month of daily bedtime instillations of Stelphrin Supra. Results. We noted a significant decrease in the tone of accommodation in the open field by 90 % from the initial value, an approximation of the nearest point of clear vision by 27 %, an increase in the volume of absolute accommodation by 57 % and the objective amplitude of accommodation by 20 %, which indicates an increase in the accommodation ability. The pupil width increased 30 minutes after a single instillation of Stelphrin Supra, which coincided with an increase in the relative accommodation reserve by 25 % from the initial one. After a month, the pupil width significantly decreased, and the positive relative accommodation reserve decreased to a level only 12 % higher than the original one. Tear film break time significantly increased by 0.89 sec, singular spot stainings disappeared in 2 out of 6 patients, lacrimation — in 6 out of 10, pain — in 1 out of 2, blurring in 4 out of 6, feeling of “sand” — in 7 out of 9 patients who had these symptoms before instillations. Conclusion. Regular instillations of Stelphrin Supra reduce the habitual tone of accommodation, increase the accommodation ability, and improve the condition of the eye surface.

Towards Sustainable Museum Conservation Practices: A Study on the Surface Cleaning of Contemporary Art and Design Objects with the Use of Biodegradable Agents

Green contemporary art conservation cleaning methods are explored as sustainable museum practices, ensuring the conservator’s health and reducing the environmental impact. The performance of selected biodegradable cleaning agents, namely deionised (DI) water, a chelate based on trisodium salt of methylglycinediacetic acid (MGDA), Trilon® M, a non-ionic surfactant based on alkoxylated fatty alcohols (Plurafac® LF900), and two solvents, limonene and ethyl lactate, was evaluated for the surface cleaning of polymethyl methacrylate (PMMA), polylactic acid (PLA), polypropylene (PP), and plasticized polyvinyl chloride (pPVC). Plastic mockups were used untreated or artificially soiled, simulating particulate matter or sebum stains produced by handling. Furthermore, the efficacy of ink removal from the plastic’s surface was evaluated. Surface examination was carried out using optical microscopy (OM), scanning electron microscopy (SEM), and atomic force microscopy (AFM), while μ-Raman and gloss measurements complemented the cleaning assessment methodology. The cleaning agents’ potency depends on the type of plastic, precluding a general cleaning protocol. However, their cleaning efficacy is very promising, enriching the available choices for the cleaning of plastics, using sustainable materials and practices. This study offers valuable information to the conservation field regarding the effects of the selected biodegradable cleaning agents on each type of plastic, their application method, and their cleaning efficacy for the removal of different types of soil and ink.

An investigation into the role of specimen geometry when undertaking tribological testing on seal fin components

Labyrinth seal systems are used in aeroengines to seal the clearance, the understanding of the wear mechanism of labyrinth seal system is necessary to achieve better sealing performance. In this work a series of tests are conducted on a high-speed test rig capable of fin tip speeds of 100 m/s. With force and temperature measurements recorded in each case, the influence of specimen geometry is investigated. Surface examination and debris analysis is also performed using microscopy post-test. The wear mechanism was found to be influenced by fin geometry. A discrete fin was observed to trigger a more efficient material removal mechanism at both incursion conditions. Where the fin segment and ring-shaped fin leading to increased temperatures and material smearing. The heat dissipate role of fin was also observed during test where longer contact time of fin and abradable gives better heat removal performance.

Corrosion behavior of GeO2 and Sc2O3 Coatings on AZ31 Alloy

In this work, GeO2 (germanium dioxide) and Sc2O3 (scandium trioxide) were developed as coatings on AZ31 alloy using polymer binder. The coatings were characterized using X-ray crystallography procedure (XRD), infrared spectrum of absorption or emission of a solid procedure (FTIR), Raman spectroscopy procedure, surface examination by FESEM. The corrosion studies were analyzed using a three electrode system in 3.5% NaCl electrolyte. The bare AZ31 alloy showed open circuit potential (Ecorr) of -1.7 V (SCE) and the corrosion current density (icorr) of 3.4 x 10-4 mA/cm2, while the Sc2O3 coated AZ31 alloy exhibited Ecorr of -1.4 V (SCE) and the icorr of 5.4 x 10-9 mA/cm2 and while the GeO2 coated AZ31 alloy exhibited Ecorr of -1.3 V (SCE) and the icorr of 2.59 x 10-9 mA/cm2. The results reveal that the GeO2 coated AZ31 alloy demonstrated higher corrosion resistance than of bare AZ31 alloy and Sc2O3 coated AZ31 alloy.

Assessment of Some Habits and Practices related to Complete Denture Wearing – A Survey of Subjects Reporting to Watim Dental Hospital

Objective: To assess some habits and practices related to denture wearing among subjects reporting to Watim Teaching Dental Hospital, Rawalpindi. Materials and Methods: This is a cross-sectional study conducted at Watim Dental College, Rawalpindi, from December 2018 to August 2019. Using a pre-structured questionnaire, data were collected from 155 subjects having used complete dentures for a minimum of 6-months. The questionnaire consisted of information including the type of dentures, duration and frequency of denture wearing, and denture cleaning habits. Data were analyzed using SPSS version 20. Results: Out of 155 participants, 80 (51.6%) were male and 75 (48.4%) were females. 89 (57.4%) patients use toothbrushes and soap for denture cleaning. 139 (89.7%) participants didn’t wear dentures while sleeping and soaked them in water. 98 (63.2%) respondents were not using antiseptic oral rinse and were casual in mouth-cleaning. Conclusion: From this study, it is concluded that 65 (41.9%) subjects were cleaning their dentures once a day. The study also reveals that 65 (41.9%) edentulous participants were not able to clean their oral cavity. Dentists should emphasize the importance of recall visits to evaluate the status of denture hygiene along with mucosal surface examination. Patient motivation to follow hygiene instructions and informing them about the harmful effects of overnight wearing of dentures should be part of delivering the prostheses to them.

Metallurgical and Mechanical Failure Analysis of an Aftermarket Flywheel

A failure analysis investigation was performed on the remnants of an aftermarket gray cast iron flywheel that catastrophically fractured during operation in a vehicle after 24 miles of operation. Light microscopy, 3D X-ray micro-computed tomography (micro-CT), scanning electron microscopy (SEM), metallography, and hardness/tensile testing techniques were utilized to characterize manufacturing quality, mode(s) of failure, microstructural variation, fracture surfaces, and mechanical properties of the failed component. Light microscopy examination of the remnant surfaces showed that the flywheel shattered with signs of radial heat checking fissure cracks. A metallurgical examination of the flywheel showed that it was manufactured from cast gray iron, with evidence of microstructural changes near heat-affected zones from graphite flakes in a ferrite/pearlite matrix to needle and lath formations similar to bainite or martensitic phases. The CT scan slices and fracture surface examination in the SEM showed signs of porosity and dendritic formations along a fracture surface believed to be the crack initiation location. The analysis suggests manufacturing flaws found within the flywheel were a likely contributing factor leading to premature failure during service.

Jules Horowitz Reactor Irradiation Devices: Inspection Methods proposal

Jules Horowitz Reactor (JHR) irradiation test devices (so called ADELINE and MADISON) must undergo a periodic inspection every 40 months (French ESP(N) Regulation). The first step of inspection proposal was performed from October 2019 to March 2020 and concerns application of non-destructive methods for electron beam welds, while examining the possible methods and locations that could be utilized. This study has been performed in collaboration between VTT Technical Research Centre of Finland Ltd and French CEA with VTT employee secondment at CEA Cadarache. The initial conclusions of this work are the following: • Two inspection methods are likely needed. • Eddy current is likely suitable for surface examination while volumetric ultrasonic inspection can be used for tube bodies. • Inspection under-water in a storage pool (EPI) is likely the best option for location in the JHR. • Some automation and remote controls will be needed during the inspection process. The inspection area is quite large as the whole tube bodies will be inspected. • Internal surfaces located between the nested tubes likely cannot be inspected for corrosion and therefore, sealing the space from oxygen and water will be likely be the best option. • Experimental reference is a critical next step of the work to assess and qualify the inspection methods. As the next step, CEA will continue discussions on requirements of the mock-ups: for eddy current inspection, a Zircaloy-4 planar specimen with artificial reflectors is needed. For ultrasonic reference, a representative mock-up of the cylinder with a weld and artificial defect(s) is needed. The mock-up testing will provide an experimental reference to CIVA calculations as simulations of this work have been performed with CIVA software, which is extensively used in the industry and research organizations in simulation of non-destructive control. This study will allow further steps in the future, up to the qualification of inspection methods for JHR test devices.