P. Knapkiewicz

Tube‐In‐Tube Reactor as a Useful Tool for Homo‐ and Heterogeneous Olefin Metathesis under Continuous Flow Mode

A tube-in-tube reactor was successfully applied in homo- and heterogeneous olefin metathesis reactions under continuous flow mode. It was shown that the efficient removal of ethylene facilitated by connection of the reactor with a vacuum pump significantly improves the outcome of metathesis reactions. The beneficial aspects of this approach are most apparent in reactions performed at low concentration, such as macrocyclization reactions. The established system allows achievement of both improved yield and selectivity, and is ideal for industrial applications.

First-order cancellation of the Cs clock frequency temperature-dependence in Ne-Ar buffer gas mixture

Through the detection of Coherent Population Trapping (CPT) resonances, we demonstrate the temperature-dependence cancellation of the Cs clock frequency in microfabricated vapor cells filled with a mixture of Ne and Ar. The inversion temperature at which the Cs clock frequency temperature sensitivity is greatly reduced only depends on the partial pressure of buffer gases and is measured to be lower than 80°C as expected with simple theoretical calculations. These results are important for the development of state-of-the-art Cs vapor cell clocks with improved long-term frequency stability.

Microsensors for Microreaction and Lab-on-a-Chip Applications

Since the first successful applications of the microfluidical devices, measurement of physical, chemical and biochemical parameters of performed reactions and analysis became next challenge and millstone towards successful application of developed instrumentation in many field of science and industry, as well as, deeper understating of microand nanoworld of fluidics (Ehrfeld at al., 2005). Although, methodology of these measurements was well known from many years, the main problems that occurred were dimensional incompatibility of available macroscopic solutions and sensing problems caused by significant reduction of managed and analyzed volumes. Therefore, microsensors became important part of the microfluidical device enabling real-time and on-chip measurement of measurable parameters like pressure, temperature, conductivity, absorbance or fluorescence. In this chapter miniature on-chip integrated pressure sensors, discreet corrosion resistant pressure sensor and conductometric flow-through detector will be described in details. Nevertheless, optical microrensors like absorbance NIR and VIS detector, as well as fluorometric detector will be shown. Technology of the sensors utilizes microengineering techniques where silicon and glass play main role as constructional materials. Threedimensional formation and assembling techniques of silicon and glass allow to fabricate miniature sensors. For each presented microsensor, the fabrication techniques will be described in details. Great attention is also paid for development of the complete measurement system consisting of the microsensors itself but also specialized electronics and information environment for full data management and measurement or analyse result presentation.

MEMS ion-sorption high vacuum pump

In the article a miniature MEMS-type ion-sorption vacuum pump has been presented. The influence of electric and magnetic field, as well as horizontal and vertical dimensions of the micropump and type of material used for electrodes on the pump properties has been investigated. It has been found that the micropump works efficiently as long as the magnetic field is higher than 0.3 T, and pumping cell is larger than 1x1x1 mm3. The pump allows generating vacuum at the level of 10-7-10-9 hPa in 100 mm3 volume.

Wireless passive high-doses radiation sensor

The high dose measurement techniques are of the great interest in nuclear engineering for both, industrial and academic community. Related to these very harsh environment, today sensors solutions are based on external post analysis that not allow real time monitoring. Wireless monitoring of fully chipless passive sensors has been demonstrated for the first time using miniaturized HPD (Hydrogen Pressure Dosimitry) solution. We obtained micrometric silicon membrane deflection for several ten of kGy using 6MeV electron beam.

Wireless hydrogen pressure dosimeter for nuclear high dose monitoring

This communication reports the very first experimental results on an original wireless, chipless and passive (battery-less) sensor for monitoring high doses of nuclear radiation. The micro-sensor combines a miniature hydrogen pressure dosimeter with a passive microwave resonator. The pressure response is derived from Sn-parameter measurement using vacuum and atmospheric pressure conditions. After e-beam irradiation (20kGy) the resonant frequency shift of the resonator ranges between 0.12%/kGy and 0.42%/kGy while the hydrogen pressure inside the cavity varies from 20mbar/kGy to 90mbar/kGy. No significant frequency shift is observed when using sensors during 6 months. These results demonstrate that a good hydrogen hermetic seal was fabricated during the manufacturing process of the constitutive micro-cavity.

Mechatronic laboratory stand

The paper presents the developed mechatronic system stand that allows to study the atmosphere parameters and conduct a number of laboratory works on mechatronic systems. The structure of the stand was built, which includes a tube, a set of sensors, a set of devices impacting gas environment and means to process data from sensors. A physical model of the stand was developed. Specialized software that provides a representation of measured data in a user friendly manner and convenient means to influence the gas flow was designed and programmed. Methodological support (manuals and instructions) for the stand was created.

Mechatronic, autonomous system for movement assessment of horses — Preliminary study

This article presents preliminary study on mechatronics, autonomous system for movement assessment of horses. The significance of providing research, where examines done in natural environment for animals to achieve a true picture of the movement and behavior of the animals is the most important factor, is discussed in details. Concept of the system and first results of tests have been presented. Results have been briefly discussed; movement asymmetry of horses legs (diseases and healthy) have been noticed what proves that the developed system can be used for rapid detection of diseases or monitoring of progress in the horse treatment and rehabilitation.

Cs collisional frequency shift measurements in microcells filled with a Ne-Ar buffer gas mixture

We report on the measurement of the dependence on temperature of the Cs clock frequency in microfabricated vapor cells filled with a mixture of Ne and Ar through the detection of Coherent Population Trapping (CPT) resonances. The temperature-dependence reduction of the Cs clock frequency is demonstrated in various cells. The inversion temperature at which the Cs clock frequency sensitivity is greatly reduced is found to be only dependent on the partial pressure of buffer gases and is measured to be lower than 80°C as expected with simple theoretical calculations.