A Statistical Model to Determine Biomechanical Limits for Physically Safe Interactions With Collaborative Robots.

Collaborative robots (cobots) provide a wide range of opportunities to improve the ergonomics and efficiency of manual work stations. ISO/TS 15066 defines power and force limiting (PFL) as one of four safeguarding modes for these robots. PFL specifies biomechanical limits for hazardous impacts and pinching contacts that a cobot must not exceed to protect humans from serious injuries. Most of the limits in ISO/TS 15066 are preliminary, since they are based on unverified data from a literature survey. This article presents a human-subject study that provides new and experimentally verified limits for biomechanically safe interactions between humans and cobots. The new limits are specifically tailored to impact and pinching transferred through blunt and semi-sharp surfaces as they can occur in the event of human error or technical failures. Altogether 112 subjects participated in the study and were subjected to tests with emulated impact and pinching loads at 28 different body locations. During the experiments, the contact force was gradually increased until the load evoked a slightly painful feeling on the subject's body location under test. The results confirm that the pain thresholds of males and females are different in specific body regions. Therefore, when defining biomechanical limits, the gender difference must be taken into account. A regression model was utilized to incorporate the gender effect as a covariate into a conventional statistical distribution model that can be used to calculate individual limits, precisely fitted to a specific percentile of a mixed group of male and female workers which interacting with cobots.

Application of infrared spectrophotometry to the identification of inorganic substances in dosage forms of Antacida group.

Powdered tablets from the Antacida group: Alusal, Milk of Magnesia, Alumag, Maalox, Magnosil, Alugastrin, Malugastrin, Rennie, and components deciding about their antiacidity like Al(OH)3, Mg(OH)2, Mg2Si3O8, NaAl(OH)2CO3, MgAl(OH)(SO4)2, CaCO3, MgCO3, were subjected to infrared spectrophotometric investigations. It was found that infrared spectra of each pharmaceutical compound are different and show a series of characteristic maxima, by which they can be identified with in the spectral range of 4000 cm-1-200 cm-1. Comparison of infrared spectra of finished products with spectra of their components it was showed that the application of infrared spectrophotometry methods enabled us to prove the presence of particular compounds used in formulations. Tablet mass and odorizing agents do not cause significant changes in spectra of the tablets studied, preparations from the Antacida group.

Physico-chemical investigation of AlPO4 for the manufacture of antacids. I. Effect of precipitation and processing conditions on physico-chemical properties of AlPO4.

Aluminium phosphate was precipitated from AlCl3-H3PO4 and NaOH, NH3H2O and NaHCO3--Na2CO3 mixture up to different pH values. The precipitates were dried at room temperature, 40 degrees and 105 degrees and their neutralizing properties (rate of neutralization and acid-consuming capacity) against 0.l N HCl were investigated. It was found that these properties depend on the nature of the reagents used for the formation of AlPO4, the pH and also the temperature of drying. The best antacid properties shows the AlPO4 preperation obtained from AlCl3-H3PO4 and NaHCO3-Na2CO3. For comparison, the therapeutic preparate "Aluphos" was also investigated.