Development Of A Biaxial Testing Apparatus

<div>Material testing is a crucial part of engineering design and development, especially in aerospace engineering as it is more cost effective to test an element or component than doing a full-scale test on the completed part. Typically, uniaxial testing is carried out to characterize a material,</div><div>which is adequate for finding the properties of the material. However, these kinds of tests are inadequate for simulating the real-world loading that a component may experience in its life cycle. Therefore, this project’s goal was to develop a low-cost biaxial testing apparatus using off-the-shelf components, including the Arduino Uno microcontroller (“Arduino”), stepper motors (“motors”), and load cell. This report outlines the development of the software required to</div><div>operate the motors and read output value of the load cell. The Arduino code used to control the motors was developed using open-source code available on GitHub and the Stepper library, which contains the required functions for controlling the motors. The Arduino code can be used</div><div>to determine the strain rate of up to 11 𝑚𝑚/𝑚𝑖𝑛, as well as the type of loading (tension or compression) along each axis. </div>

Development Of A Biaxial Testing Apparatus

<div>Material testing is a crucial part of engineering design and development, especially in aerospace engineering as it is more cost effective to test an element or component than doing a full-scale test on the completed part. Typically, uniaxial testing is carried out to characterize a material,</div><div>which is adequate for finding the properties of the material. However, these kinds of tests are inadequate for simulating the real-world loading that a component may experience in its life cycle. Therefore, this project’s goal was to develop a low-cost biaxial testing apparatus using off-the-shelf components, including the Arduino Uno microcontroller (“Arduino”), stepper motors (“motors”), and load cell. This report outlines the development of the software required to</div><div>operate the motors and read output value of the load cell. The Arduino code used to control the motors was developed using open-source code available on GitHub and the Stepper library, which contains the required functions for controlling the motors. The Arduino code can be used</div><div>to determine the strain rate of up to 11 𝑚𝑚/𝑚𝑖𝑛, as well as the type of loading (tension or compression) along each axis. </div>

Assessing the filtration efficiency and regulatory status of N95s and nontraditional filtering face-piece respirators available during the COVID-19 pandemic

Background The COVID-19 pandemic has severely disrupted supply chains for many types of Personal Protective Equipment (PPE), particularly surgical N95 filtering facepiece respirators (FFRs; “masks”). As a consequence, an Emergency Use Authorization (EUA) from the FDA has allowed use of industrial N95 respirators and importation of N95-type masks manufactured to international standards; these include KN95 masks from China and FFP2 masks from the European Union. Methods We conducted a survey of masks in the inventory of major academic medical centers in Boston, MA to determine provenance and manufacturer or supplier. We then assembled a testing apparatus at a university laboratory and performed a modified test of filtration performance using KCl and ambient particulate matter on masks from hospital inventories; an accompanying website shows how to build and use the testing apparatus. Results Over 100 different makes and models of traditional and nontraditional filtering facepiece respirators (N95-type masks) were in the inventory of surveyed U.S. teaching hospitals as opposed to 2–5 models under normal circumstances. A substantial number of unfamiliar masks are from unknown manufacturers. Many are not correctly labelled and do not perform to accepted standards and a subset are obviously dangerous; many of these masks are likely to be counterfeit. Due to the absence of publicly available information on mask suppliers and inconsistent labeling of KN95 masks, it is difficult to distinguish between legitimate and counterfeit products. Conclusions Many FFRs available for procurement during the COVID-19 pandemic do not provide levels of fit and filtration similar to those of N95 masks and are not acceptable for use in healthcare settings. Based on these results, and in consultation with occupational health officers, we make six recommendations to assist end users in acquiring legitimate products. Institutions should always assess masks from non-traditional supply chains by checking their markings and manufacturer information against data provided by NIOSH and the latest FDA EUA Appendix A. In the absence of verifiable information on the legitimacy of mask source, institutions should consider measuring mask fit and filtration directly. We also make suggestions for regulatory agencies regarding labeling and public disclosure aimed at increasing pandemic resilience.

Possibilities of Adaptive Testing Usage in Students' e-Learning

The paper considers the possibilities of adaptive testing in the organization of e-learning in the educational environment of the university with the help of electronic educational resources. The author analyzes the possibilities of adaptive testing and the practice of its application in the works of many authors. A variant of using the adaptive testing apparatus for managing the student's educational vector is proposed.