Design of a specific MATLAB code for processing of standard tensile test data for sheet metal forming simulations

In order to obtain proper and sufficiently precise results from metal forming simulations, accurate material data should be input to the simulation software. One of the most important input for the simulation software is the flow curve yield curve of the material. Although there are many tests which could be performed in order to construct the flow curve such as standard tensile test, hydraulic bulge test, frictionless dome test, etc., standard tensile test is the simplest and cheapest technique despite of its technical restrictions. In this article, the studies regarding to the creation of a specific MatLab code for processing of tensile test data are presented. This specific MatLab code is capable of determining the constants of Hollomon’s, Ludwig’s, Swift’s and Voce’s hardening equations with their regression results, as well. By means of this code, the proper flow curve of any material and also the Lankford parameters could be obtained and the hardening equations which fits best to the experimental data could be determined

Conjunctival Impression Cytology and Tear Film Changes in Sarcoidosis: A Subjective and Objective Diagnosis Study

Objectives:To evaluate sarcoidosis-induced tear film changes using subjective and objective diagnostic tests, particularly conjunctival impression cytology (IC), and to compare the results with healthy individuals.Materials and Methods:This study evaluated clinical data collected between January 2019 and January 2021 from 57 right eyes of 57 sarcoidosis patients without ocular involvement (Group 1) and 33 right eyes of 33 healthy individuals with similar demographic characteristics (Group 2). The Schirmer I test, tear break-up time (TBUT), fluorescein staining, and conjunctival IC were all performed as part of the conjunctival and corneal examinations following a thorough ophthalmological examination. The Ocular Surface Disease Index (OSDI) was used to assess subjective ocular symptoms.Results:The mean ages in Groups 1 and 2 were 49.26±3.18 and 51.91±2.89 years, respectively (p=0.720). The mean Schirmer I test, TBUT, and OSDI scores differed significantly (p<0.05 for all), with Group 1 having a significantly higher percentage of dry eyes than Group 2. Group 1 had significantly higher Nelson’s grading system grades than Group 2 based on conjunctival IC analysis (p=0.001). There were no significant differences in visual acuity (p=0.17) or intraocular pressure (p=0.14) between groups.Conclusion:Sarcoidosis patients had significantly higher Nelson grades in conjunctival IC, as well as significantly higher percentages of dry eye as determined by the Schirmer I test, TBUT, and OSDI. Reduced tear quantity and quality may destabilize the tear film layer, resulting in a variety of ocular symptoms

Epidemiologic and Clinical Features of Open-Globe Injuries in Childhood

Pur po se: To evaluate the epidemiologic and clinical features of open-globe injuries in childhood. Ma te ri al and Met hod: The records of the pediatric patients who were evaluated for open-globe injuries between 2007 and 2011 in our department were retrospectively screened. Age, gender, time, setting, localization and cause of injury, follow-up time, complications, number of surgeries, initial and final visual acuity were assessed. Re sults: A total of 37 patients were enrolled in the study. Of 37 patients, 12 (32.4%) were girls and 25 (67.6%) were boys with a mean age of 9.9±4.5. Boy/girl rate was likely to increase as the age increased (p=0.018). Twenty-one (56.8%) patients were injured during play. The time interval between injury and admission to the hospital was 15.9±29.4 hours. Injuries were most likely to have occurred on the street (48.6%) and at home (40.5%). Boys were more likely to be injured on the street (68%), whereas girls were more likely to be injured at home (83.3%) (p=0.001). The most common objects causing injury were sharp metal and wood tools (29.7% - for both genders). Injury was corneal in 22 (59.5%) patients and scleral in 8 (21.6%) patients. In 18 (48.6%) patients, the injury was complicated, and cataract was the most common complication. Reoperation was needed in 16 (43.2%) patients. Final visual acuity was equal to or better than 0.5 in 54% of the patients. Final visual acuity correlated with initial visual acuity (p=0.004, r=0.491). Dis cus si on: Open-globe injuries in childhood mostly occur at home or on the street via sharp wood or metal objects. Nearly a quarter of all patients suffer from low vision as a result of these injuries which are mostly preventable. (Turk J Ophthalmol 2012; 42: 16-9