Metrological characterization of MEMS accelerometers by LDV

Abstract In this work two calibration methodologies, able to characterize the digital sensitivity of MEMS accelerometers, are presented and compared, to identify the contributions for the evaluation of the reproducibility in the low frequency range. The methodologies are different from the point of view of test bench, test procedure and data processing method. In particular, different vibration actuators are used, a linear slide and an electro-dynamic shaker, different sensors as a reference for the calibration, piezoelectric accelerometers and a Laser Doppler Vibrometer (LDV). A group of 5 accelerometers is tested for the purpose of developing the calibration techniques and evaluate a first reproducibility estimate. The experimental results provided by the two calibration procedures show significant differences. Some elements that could explain these differences have been identified, and will be further investigated in future work

Uncertainty of slip measurements in a cutting system of converting machinery for diapers production

In this paper slip measurements are described between the peripheral surfaces of knife and a not driven anvil cylinders in a high velocity, high quality cutting unit of a diaper production line. Laboratory tests have been carried out on a test bench with real scale components for possible on line application of the method. With reference to both starting and steady state conditions correlations with the process parameters have been found, achieving a very satisfactory reduction of the slip between the knife cylinder and the not driven anvil one. Accuracy evaluation of measurements allowed us to validate the obtained information and to evaluate the detection threshold of the measurement method in the present configuration The analysis of specific uncertainty contributions to the whole uncertainty could be also used, to further reduce the requested uncertainty of the measurement method

Uncertainty of slip measurements in a cutting system of converting machinery for diapers production

In this paper slip measurements are described between the peripheral surfaces of knife and a not driven anvil cylinders in a high velocity, high quality cutting unit of a diaper production line. Laboratory tests have been carried out on a test bench with real scale components for possible on line application of the method. With reference to both starting and steady state conditions correlations with the process parameters have been found, achieving a very satisfactory reduction of the slip between the knife cylinder and the not driven anvil one. Accuracy evaluation of measurements allowed us to validate the obtained information and to evaluate the detection threshold of the measurement method in the present configuration The analysis of specific uncertainty contributions to the whole uncertainty could be also used, to further reduce the requested uncertainty of the measurement method

Somali Contract Law: Constitutional and Comparative Perspectives

The essay frames the rules on contract law in Somalia in the constitutional framework. The essay compares Somali contract law with the systems provided for in other Islamic African countries, and pays particular attention to the development of Somalia as a federal state and its implications for the rules on contract law

DIC and Photogrammetry for Structural Dynamic Analysis and High-Speed Testing

This chapter provides an overview and some important considerations to be made when making optical and stereophotogrammetry measurements on structures for dynamic applications. In particular, the chapter focuses on leveraging those measurements to perform digital image correlation (DIC) to extract dynamic parameters (e.g., strain, deflection, operating shapes, and mode shapes). Structural dynamic testing and analysis in the context of performing optical measurements is described. Information on optical high rate testing is also presented along with lessons learned and best practices