Versatile Experimental Setup Research Articles

Development of a versatile experimental setup for the evaluation of the photocatalytic properties of construction materials under realistic outdoor conditions

The interest on outdoor photocatalytic materials is growing in the last years. Nevertheless, most of the experimental devices designed for the assessment of their performance operate at controlled laboratory conditions, i.e., pollutant concentration, temperature, UV irradiation, and water vapor contents, far from those of real outdoor environments. The aim of the present study was the design and development of an experimental device for the continuous test of photocatalytic outdoor materials under sun irradiation using real outdoor air as feed, with the concomitant fluctuation of pollutant concentration, temperature, and water vapor content. A three-port measurement system based on two UV-transparent chambers was designed and built. A test chamber contained the photoactive element and a reference chamber to place the substrate without the photoactive element were employed. The third sampling point, placed outdoors, allowed the characterization of the surrounding air, which feeds the test chambers. Temperature, relative humidity (RH), and UV-A irradiance were monitored at each sampling point with specific sensors. NO x concentration was measured by a chemiluminescence NO x analyzer. Three automatic valves allowed the consecutive analysis of the concentration at the three points at fixed time intervals. The reliability of the analytical system was demonstrated by comparing the NO x concentration data with those obtained at the nearest weather station to the experimental device location. The use of a chamber-based reaction system leads to an attenuation of NO x and atmospheric parameter profiles, but maintaining the general trends. The air characterization results showed the wide operating window under which the photoactive materials should work outdoors, depending on the traffic intensity and the season, which are reproduced inside the test chambers. The designed system allows the measurement of the photoactivity of outdoor materials or the comparison of several samples at the same time. The suitability of the system for the evaluation of the DeNO x properties of construction elements at realistic outdoor conditions was demonstrated. The designed experimental device can be used 24/7 for testing materials under real fluctuations of NO x concentration, temperature, UV irradiation, and relative humidity and the presence of other outdoor air pollutants such as VOCs, SO x , or NH3. The chamber-based design allows comparing a photocatalytic material with respect to a reference substrate without the photoactive phase, or even the comparison of several outdoor elements at the same time.

The multipurpose X-ray diffraction end-station of the BM25B-SpLine synchrotron beamline at the ESRF

The Spanish BM25-SpLine beamline at the European Synchrotron Radiation Facility allocates in the first focal point of Branch B a versatile experimental set-up devoted to X-ray diffraction studies. X-Ray Reflectivity, Reciprocal Space Maps, Surface, Single Crystal, Grazing Incidence and High Resolution Powder Diffraction can be performed using a point detector or a 2D detector (Charge-Coupled Device), in combination with many sample environment setups. A detailed description of the end-station is presented, including several examples that demonstrate the excellent capabilities of the setup.

Implementation of a spatial two-dimensional quantum random walk with tunable decoherence

We put forward a new, versatile and highly-scalable experimental setup for the realization of discrete two-dimensional quantum random walks with a single-qubit coin and tunable degree of decoherence. The proposed scheme makes use of a small number of simple optical components arranged in a multi-path Mach-Zehnder-like configuration, where a weak coherent state with average photon number of 1 is injected. Environmental effects (decoherence) are generated by a spatial light modulator, which introduces pure dephasing in the transverse spatial plane, perpendicular to the direction of propagation of the light beam. By controlling the characteristics of this dephasing, one can explore a great variety of scenarios of quantum random walks: pure quantum evolution (ballistic spread), fast fluctuating environment leading to a diffusive classical random walk, and static disorder resulting in the observation of Anderson localization.

Modulated heterodyne light scattering set-up for measuring long relaxation time at small and wide angle

We present a simple, compact, and versatile experimental setup working in the heterodyne detection mode with modulation of the reference beam. The system is implemented with a collection optics based on a unimodal optical fiber coupler. This choice allows the heterodyne to be used in a wide range of scattering angles, even for very small ones, without losing the optical beating. The apparatus can be successfully used to study translational diffusive dynamics of dispersed particles at scattering angles smaller than 5° and it is suitable for exploring slow relaxation processes in sub-Hertz frequency domain, for example, in glass-forming systems. It is also possible to measure the electrophoretic mobility by applying an electric field into a charged particles solution.

Combined electrospray ionization source with a velocity map imaging spectrometer for studying large gas phase molecular ions

We present a new compact and versatile experimental set-up that has been designed to perform electron and ion imaging experiments on large multiply charged gas phase molecular and cluster species. It combines an electrospray ionization source, a quadrupole mass filter guiding ion optics and a velocity map imaging spectrometer. Characterization of the spectrometer has been performed on atomic ions. Results obtained on molecular species (stilbene 420 dianions) demonstrate the possibility offered by this experimental set-up.

Influence of environmental relative humidity on the tensile and rotational behaviour of hemp fibres

The aim of this study is to throw new light on the influence of moisture on the mechanical properties of hemp fibres. Indeed, the behaviour of plant-based fibres strongly depends on their humidity. Although this topic has been relatively well treated for the case of wood, the literature on fibre stemming from annual plants is unfortunately poor. This purpose is, however, of great importance, particularly in view of the production of high-performance composites. The influence of environmental conditions on the static and dynamic tensile moduli and the strength of elementary fibres are investigated using a versatile experimental setup. Novel equipment was also designed to measure the rotation of a fibre about its axis when it was subjected to static loading and moisture variations. Water sorption is shown to have a significant influence on the apparent tensile stiffness, strength and fracture mode of such fibres, and is also shown to act like an activator of the stiffening phenomena under cyclic loading. A remarkable increase in the fibre stiffness of up to 250% is measured. Significant longitudinal elongation, reaching a value in excess of 2%, is associated with this increase in stiffness. The absorption and desorption of moisture also lead to substantial rotation of the fibre about its axis. Water sorption certainly involves a modification of the adhesion between cellulose microfibrils and the amorphous matrix. Under cyclic loading, the cellulose microfibrils could be able to creep into the relaxed amorphous matrix, leading to their re-arrangement, with more parallel orientations with respect to the fibre axis.

Experimental Study of High-Frequency Vibration Assisted Micro/Mesoscale Forming of Metallic Materials

Micro/mesoscale forming is a promising technology for mass production of miniature metallic parts. However, fabrication of micro/mesoscale features leads to challenges due to the friction increase at the interface and tool wear from highly localized stress. In this study, the use of high-frequency vibration for potential application in micro/mesoscale forming has been investigated. A versatile experimental setup based on a magnetostrictive (Terfenol-D) actuator was built. Vibration assisted micro/mesoscale upsetting, pin extrusion and cup extrusion were conducted to understand the effects of workpiece size, excitation frequency, and the contact condition. Results showed a change in load reduction behavior that was dependent on the excitation frequency and the contact condition. The load reduction exhibited in this study can be explained by a combination of stress superposition and friction reduction. It was found that a higher excitation frequency and a less complicated die-specimen interface were more likely to result in a friction reduction by high-frequency vibration.

Characterisation and calibration of active sampling Solid Phase Microextraction applied to sensitive determination of gaseous carbonyls

A characterisation of a system designed for active sampling of gaseous compounds with Solid Phase Microextraction (SPME) fibres is described. This form of sampling is useful to automate sampling while considerably reducing the sampling times. However, the efficiency of this form of sampling is also prone to be affected by certain undesirable effects such as fibre saturation, competition or displacement effects between analytes, to which particular attention should be paid especially at high flow rates. Yet, the effect of different parameters on the quantitivity of the results has not been evaluated. For this reason, in this study a careful characterisation of the influence of the parameters involved in active sampling SPME has been performed. A versatile experimental set-up has been designed to test the influence of air velocities and fluid regime on the quantitivity and reproducibility of the results. The mathematical model applied to the calculation of physical parameters at the sampling points takes into consideration the inherent characteristics of gases, distinctive from liquids and makes use of easily determined experimental variables as initial/boundary conditions to get the model started.The studies were carried out in the high-volume outdoor environmental chambers, EUPHORE. The sample subjected to study was a mixture of three aldehydes: pentanal, hexanal and heptanal and the determination methodology was O-(2,3,4,5,6-pentafluorobenzyl)-hydroxylamine hydrochloride (PFBHA) on-fibre derivatisation.The present work proves that the determination procedure is quantitative and sensitive, independent from experimental conditions: temperature, relative humidity or ozone levels.With our methodology, the influence on adsorption of three inter-related variables, i.e., air velocity, flow rate and Reynolds numbers can be separated, since a change can be exerted in one of them while keeping the others constant.

Reduction of background signals in fiber-based NICE-OHMS

Noise-immune cavity-enhanced optical heterodyne molecular spectroscopy (NICE-OHMS) based on a fiber-coupled electro-optic modulator (EOM) provides a compact and versatile experimental setup. It has ...

Digitally tunable, wide-band amplitude, phase, and frequency detection for atomic-resolution scanning force microscopy

Frequency-modulation atomic force microscopy (FM-AFM) relies on an accurate tracking of the resonance frequency of a scanning probe. It is now used in environments ranging from ultrahigh vacuum to aqueous solutions, for slow and for fast imaging, with probes resonating from a few kilohertz up to several megahertz. Here we present a versatile experimental setup that detects amplitude, phase, and frequency of AFM probes for resonance frequencies up to 15 MHz and with >70 kHz maximum bandwidth for amplitude/phase detection. We provide generic parameter settings for variable-bandwidth frequency detection and test these using our setup. The signal-to-noise ratio of the frequency detector is sufficiently high to record atomic-resolution images of mica by FM-AFM in aqueous solution.

Experimental setup forin situX-ray SAXS/WAXS/PDF studies of the formation and growth of nanoparticles in near- and supercritical fluids

The growing interest in inorganic nanoparticles for a wide range of applications is spurring a need for synthesis methods that allow a highly specific tailoring of material properties. Synthesis in supercritical fluids holds great promise for solving this problem, but so far the fundamental chemical processes taking place under these conditions are to a large extent unknown. Here the design, construction and application of a versatile experimental setup are reported; this setup enablesin situsynchrotron small-angle X-ray scattering/wide-angle X-ray scattering/pair distribution function (SAXS/WAXS/PDF) studies of the formation and growth of nanoparticles under supercritical fluid conditions.

FANTASIO: a versatile experimental set-up to investigate jet-cooled molecules

The design of a new apparatus, named FANTASIO, for studying jet-cooled molecules is described. It includes, around the same supersonic expansion cell, a high resolution Fourier transform spectrometer with single or multipass optics, a tunable diode laser spectrometer with optional cavity ring-down facilities, and a quadrupole mass spectrometer. Performance and operational procedures are illustrated.

Versatile wide angle diffraction setup for simultaneous wide and small angle x-ray scattering measurements with synchrotron radiation

Here we present a novel, simple, and versatile experimental setup aimed to perform wide angle x-ray scattering (WAXS) measurements alone or in simultaneous combination with small angle x-ray scattering measurements. The design of the WAXS goniometer allows one to obtain high resolution diffraction patterns in a broad angular range. The setup can incorporate a hot stage in order to evaluate temperature resolved experiments. The performance of the equipment has been verified in the BM16 beam line of the European Synchrotron Radiation Facility with different well known samples such as alumina, isotropic film of high density polyethylene (HDPE), and oriented HPDE fiber.

Synthesis and analysis of linear and nonlinear acoustical vortices

Acoustical screw dislocations are synthesized in various configurations with a versatile experimental setup. The experimental setup is based on the inverse filter technique and allows one to synthesize one or more acoustical vortices with a chosen width, position, and topological charge. An interesting feature of this experimental facility to study screw dislocation behavior is the direct measurement in amplitude and phase. This characteristic is used to develop an original method of decomposition of an acoustical vortex field in order to analyze the acoustical vortices. Moreover, the behaviors of two acoustical vortices of the same or opposite charge have been studied experimentally and compared to theoretical laws.

Instrumentation for FT-IR reflection spectroscopy with synchrotron radiation.

A versatile experimental set-up for infrared reflectance measurements with synchrotron radiation and its adaptation to a beamline is presented. Particular consideration is given to the collimation and the polarization of incident radiation. The performance is characterized with experimental results. Due to the high brilliance of the synchrotron radiation source, the irradiation of samples smaller than 1 mm(2) was found to be improved by more than one order of magnitude when compared to a globar.

A Transparent Environment for Experimental Validation of Basic Control Theory

This paper presents a versatile experimental setup consisting of a simple hardware construction and a proprietary software which allow easy verification of basic control concepts. This is achieved by offering the possibility to compare on-line the actual performance of the plant with derived quantities commonly used in control theory classes, like Bode and Nyquist diagrams. The hardware allows quick response times and the software enables on-line change of parameters and graphical presentation of process variables so that the students may devote a larger part of their time and energy to understand the basic ideas.

X-ray standing waves and x-ray photoemission measurements in the energy range 2.7–7 keV

A versatile experimental setup is presented for both x-ray standing waves (XSW) and x-ray photoemission spectroscopy (XPS) studies in an energy range up to 7 keV. The compact apparatus operates under ultrahigh vacuum and includes in situ sample preparation and characterization techniques. For the XSW scans the incident photon energy is tuned through the Bragg reflection from the sample for ΘB ≊ 90° while measuring the intensity and energy distributions of both the emitted electrons and fluorescence radiation simultaneously. Alternatively, desorbing positive ions can be analyzed as a function of the standing wave phase shift using a time-of-flight spectrometer. In addition, energy dependent high-energy XPS measurements with medium overall energy resolution (ΔE=1.5 eV at 3 keV) can be performed. Selected results obtained at the focused EXAFS II beamline of HASYLAB are shown.

An experimental arrangement for recording excitation-, radio-, photo- and thermoluminescence spectra

Abstract A versatile experimental set-up for in-situ measurements of excitation-, radio-, photo- and thermoluminescence (TL) spectra in the temperature range liquid nitrogen temperature (LNT) to 450°C (723°K) has been designed. In this multipurpose and elegant set-up, the limitations of the previous set-up1 of this laboratory are overcome. Because of its wider temperature range of working and utilisation of more sensitive measuring elements, it has now become possible to study and understand some of the intricate features of hole-centre production, stabilisation and annihilation associated with defect centres in even simple systems like alkali halides, that have eluded proper interpretation and hence lacked clear understanding. In spite of simple design and low cost, much more precision than the previous set-up in experimental results can be claimed. Further the set-up offers facilities for a variety of in-situ measurements on the same substance. Thermoluminescence (TL) of LNT X-rayed KCI crystals has bee...