scholarly journals MIMiX: a Multipurpose In situ Microreactor system for X-ray microspectroscopy to mimic atmospheric aerosol processing

2020 ◽  
Vol 13 (7) ◽  
pp. 3717-3729
Author(s):  
Jan-David Förster ◽  
Christian Gurk ◽  
Mark Lamneck ◽  
Haijie Tong ◽  
Florian Ditas ◽  
...  

Abstract. The dynamic processing of aerosols in the atmosphere is difficult to mimic under laboratory conditions, particularly on a single-particle level with high spatial and chemical resolution. Our new microreactor system for X-ray microscopy facilitates observations under in situ conditions and extends the accessible parameter ranges of existing setups to very high humidities and low temperatures. With the parameter margins for pressure (180–1000 hPa), temperature (∼250 K to room temperature), and relative humidity (∼0 % to above 98 %), a wide range of tropospheric conditions is covered. Unique features are the mobile design and compact size that make the instrument applicable to different synchrotron facilities. Successful first experiments were conducted at two X-ray microscopes, MAXYMUS, located at beamline UE46 of the synchrotron BESSY II, and PolLux, located at beamline X07DA of the Swiss Light Source in the Paul Scherrer Institute. Here we present the design and analytical scope of the system, along with first results from hydration–dehydration experiments on ammonium sulfate and potassium sulfate particles and the tentative observation of water ice at low temperature and high relative humidity in a secondary organic aerosol particle from isoprene oxidation.

2020 ◽  
Author(s):  
Jan-David Förster ◽  
Christian Gurk ◽  
Mark Lamneck ◽  
Haijie Tong ◽  
Florian Ditas ◽  
...  

Abstract. The dynamic processing of aerosols in the atmosphere is difficult to mimic under laboratory conditions, particularly on a single particle level with high spatial and chemical resolution. Our new microreactor system for X-ray microscopy facilitates observations under in-situ conditions and extends the accessible parameter ranges of previously reported setups to very high humidities and low temperatures. With the parameter margins for pressure (180–1000 hPa), temperature (−23 °C to room temperature), and relative humidity (~ 0 % to above 98 %), a wide range of tropospheric conditions is covered. Unique features are the mobile design and compact size that make the instrument applicable to different synchrotron facilities. Successful first experiments were conducted at two X-ray microscopes, i) MAXYMUS, located at beamline UE46 synchrotron BESSY II, Berlin, Germany, and ii) PolLux, located at beamline X07DA of the Swiss Light Source in the Paul Scherrer Institute, Villigen, Switzerland. Here we present the design and analytical scope of the system, along with first results from hydration/dehydration experiments on ammonium sulfate and potassium sulfate particles and the observation of water ice at low temperature and high relative humidity in a secondary organic aerosol particle from isoprene oxidation.


2013 ◽  
Vol 10 (9) ◽  
pp. 14595-14626 ◽  
Author(s):  
A. Canion ◽  
J. E. Kostka ◽  
T. M. Gihring ◽  
M. Huettel ◽  
J. E. E. van Beusekom ◽  
...  

Abstract. Despite decades of research on the physiology and biochemistry of nitrate/nitrite-respiring microorganisms, little is known regarding their metabolic response to temperature, especially under in situ conditions. The temperature regulation of microbial communities that mediate anammox and denitrification was investigated in near shore permeable sediments at polar, temperate, and subtropical sites with annual mean temperatures ranging from −5 to 23 °C. Total N2 production rates were determined using the isotope pairing technique in intact core incubations under diffusive and simulated advection conditions and ranged from 2 to 359 μmol N m−2 d−1. For the majority of sites studied, N2 removal was 2 to 7 times more rapid under advective flow conditions. Anammox comprised 6 to 14% of total N2 production at temperate and polar sites and was not detected at the subtropical site. Potential rates of denitrification and anammox were determined in anaerobic slurries in a temperature gradient block incubator across a temperature range of −1 to 42 °C. The highest optimum temperature (Topt) for denitrification was 36 °C and was observed in subtropical sediments, while the lowest Topt of 21 °C was observed at the polar site. Seasonal variation in the Topt was observed at the temperate site with values of 26 and 34 °C in winter and summer, respectively. The Topt values for anammox were 9 and 26 °C at the polar and temperate sites, respectively. The results demonstrate adaptation of denitrifying communities to in situ temperatures in permeable marine sediments across a wide range of temperatures, whereas marine anammox bacteria may be predominately psychrophilic to psychrotolerant. To our knowledge, we provide the first rates of denitrification and anammox from permeable sediments of a polar permanently cold ecosystem. The adaptation of microbial communities to in situ temperatures suggests that the relationship between temperature and rates of N removal is highly dependent on community structure.


2019 ◽  
Vol 11 ◽  
Author(s):  
A. G. Karydas ◽  
T. Pantazis ◽  
C. Doumas ◽  
A. Vlachopoulos ◽  
P. Nomikos ◽  
...  

In-situ X-ray fluorescence analysis (XRF) of ancient artifacts from the excavation area was performed using a novel X-ray instrumentation, composed of a portable silicon PIN thermoelectrically cooled X-ray detector, a miniature X-ray source, and portable data acquisition devices. The main objective of the analyses in Akrotiri was to explore the potential of the technique to provide answers to a wide range of archaeometric questions regarding the bulk composition of metal alloys, especially of gold, the characterization of corrosion products in bronze artifacts, identification of inorganic elements which are fingerprints of the minerals used in wall-painting pigments, and of the painting materials and techniques used for the decoration of clay vase surfaces. Among the analysed artifacts are a unique gold ibex, a bronze dagger and blade, various pigments from the wall paintings of room 3 in Xeste 3, decoration pigments from rosettes of faience, a bichrome jug, and other clay vases. The results of the in-situ XRF survey, primarily those of the bulk composition and soldering technology of the gold ibex, are discussed and compared with literature.


2020 ◽  
Author(s):  
Stephen Shearan ◽  
Jannick Jacobsen ◽  
Ferdinando Costantino ◽  
Roberto D’Amato ◽  
Dmitri Novikov ◽  
...  

We report on the results of a thorough <i>in situ</i> synchrotron powder X-ray diffraction study of the crystallisation in aqueous medium of two recently discovered perfluorinated Ce(IV)-based metal-organic frameworks (MOFs), analogues of the already well investigated Zr(IV)-based UiO-66 and MIL-140A, namely, F4_UiO-66(Ce) and F4_MIL-140A(Ce). The two MOFs were originally obtained in pure form in similar conditions, using ammonium cerium nitrate and tetrafluoroterephthalic acid as building blocks, and small variations of the reaction parameters were found to yield mixed phases. Here, we investigate the crystallisation of these compounds <i>in situ</i> in a wide range of conditions, varying parameters such as temperature, amount of the protonation modulator nitric acid (HNO<sub>3</sub>) and amount of the coordination modulator acetic acid (AcOH). When only HNO<sub>3</sub> is present in the reaction environment, F4_MIL-140A(Ce) is obtained as a pure phase. Heating preferentially accelerates nucleation, which becomes rate determining below 57 °C, whereas the modulator influences nucleation and crystal growth to a similar extent. Upon addition of AcOH to the system, alongside HNO<sub>3</sub>, mixed-phased products, consisting of F4_MIL-140A(Ce) and F4_UiO-66(Ce), are obtained. In these conditions, F4_UiO-66(Ce) is always formed faster and no interconversion between the two phases occurs. In the case of F4_UiO-66(Ce), crystal growth is always the rate determining step. An increase in the amount of HNO<sub>3</sub> slows down both nucleation and growth rates for F4_MIL-140A(Ce), whereas nucleation is mainly affected for F4_UiO-66(Ce). In addition, a higher amount HNO<sub>3</sub> favours the formation of F4_MIL-140A(Ce). Similarly, increasing the amount of AcOH leads to slowing down of the nucleation and growth rate, but favours the formation of F4_UiO-66(Ce). The pure F4_UiO-66(Ce) phase could also be obtained when using larger amounts of AcOH in the presence of minimal HNO<sub>3</sub>. Based on these <i>in situ</i> results, a new optimised route to achieving a pure, high quality F4_MIL-140A(Ce) phase in mild conditions (60 °C, 1 h) is also identified.


1981 ◽  
Vol 10 ◽  
Author(s):  
J. M. Vandenberg ◽  
F. J. A. Den Broeder ◽  
R. A. Hamm

An in situ annealing X-ray study was applied to Cu-Al thin film couples over a wide range of copper-to-aluminum film ratios. This new technique, which has been previously described for a study on the Au-Al thin film system, enables us to make a temperature-dependent photographic X-ray analysis. The present study indicated that only a limited number of the wide variety of bulk phases form in the Cu-Al thin film interface, while some of these phases in the interface are transient. In the transient stages of the interface reaction, the f.c.c.-ordered phase β-Cu3A1 grows over the entire range of copper-to-aluminum film ratios after the first nucleation of CuA12, indicating a two-step nucleation reaction. On the aluminum-rich side, this phase transforms to a new ordered hexagonal phase β′. It could be interpreted as a superlattice of the metastable hexagonal ω phase occurring in zirconium-based alloys. The end phases are CuA1 and CuAl2.


2014 ◽  
Vol 70 (a1) ◽  
pp. C1734-C1734
Author(s):  
Zoltan Gal ◽  
Tadeusz Skarzynski ◽  
Fraser White ◽  
Oliver Presly ◽  
Adrian Jones ◽  
...  

Agilent Technologies develop and supply X-ray systems for single-crystal diffraction research, including the SuperNova; a compact, highly reliable and very low maintenance instrument providing X-ray data of the highest quality; and the PX Scanner for testing and characterization of protein crystals in their original crystallization drops (in-situ). The SuperNova and PX Scanner are constantly improving, with recent enhancements including a new range of detectors using an Intelligent Measurement System. The Eos S2, Atlas S2 and Titan S2 detector range employs a smart sensitivity control of the electronic gain and is capable of instantaneously switching its binning modes thus providing unprecedented flexibility in tuning every exposure to provide the highest data quality for a wide range of experiments. We have also developed a completely new micro-focus X-ray source based on Gradient Vacuum technology, with novel filament and target designs. This novel source is an integral part of the new Agilent GV1000 X-ray diffractometer, which has been designed for applications that require even higher brightness of the X-ray beam.


1999 ◽  
Vol 590 ◽  
Author(s):  
DM Pickup ◽  
G Mountjoy ◽  
RJ Newport ◽  
ME Smith ◽  
GW Wallidge ◽  
...  

ABSTRACTSol-gel produced mixed oxide materials have been extensively studied using conventional, ex situ structural techniques. Because the structure of these materials is complex and dependent on preparation conditions, there is much to be gained from in situ techniques: the high brightness of synchrotron x-ray sources makes it possible to probe atomic structure on a short timescale, and hence in situ. Here we report recent results for mixed titania- (and some zirconia-) silica gels and xerogels. Titania contents were in the range 8–18 mol%, and heat treatments up to 500°C were applied. The results have been obtained from intrinsically rapid synchrotron x-ray experiments: i) time-resolved small angle scattering, using a quadrant detector, to follow the initial stages of aggregation between the sol and the gel; ii) the use of a curved image plate detector in diffraction, which allowed the simultaneous collection of data across a wide range of scattering at high count rate, to study heat treatments; and iii) x-ray absorption spectroscopy to explore the effects of ambient moisture on transition metal sites.


2007 ◽  
Vol 1017 ◽  
Author(s):  
Bridget Ingham ◽  
Benoit N. Illy ◽  
Jade R. Mackay ◽  
Stephen P. White ◽  
Shaun C. Hendy ◽  
...  

AbstractZnO is known to produce a wide variety of nanostructures that have enormous scope for optoelectronic applications. Using an aqueous electrochemical deposition technique, we are able to tightly control a wide range of deposition parameters (Zn2+ concentration, temperature, potential, time) and hence the resulting deposit morphology. By simultaneously conducting synchrotron x-ray absorption spectroscopy (XAS) experiments during the deposition, we are able to directly monitor the growth rates of the nanostructures, as well as providing direct chemical speciation of the films. In situ experiments such as these are critical to understanding the nucleation and growth of such nanostructures.Recent results from in situ XAS synchrotron experiments demonstrate the growth rates as a function of potential and Zn2+ concentration. These are compared with the electrochemical current density recorded during the deposition, and the final morphology revealed through ex situ high resolution electron microscopy. The results are indicative of two distinct growth regimes, and simultaneous changes in the morphology are observed.These experiments are complemented by modelling the growth of the rods in the transport-limited case, using the Nernst-Planck equations in 2 dimensions, to yield the growth rate of the volume, length, and radius as a function of time.


2011 ◽  
Vol 19 (1) ◽  
pp. 48-53 ◽  
Author(s):  
Bekir Salgin ◽  
Dirk Vogel ◽  
Diego Pontoni ◽  
Heiko Schröder ◽  
Bernd Schönberger ◽  
...  

A wide range of high-performance X-ray surface/interface characterization techniques are implemented nowadays at every synchrotron radiation source. However, these techniques are not always `non-destructive' because possible beam-induced electronic or structural changes may occur during X-ray irradiation. As these changes may be at least partially reversible, anin situtechnique is required for assessing their extent. Here the integration of a scanning Kelvin probe (SKP) set-up with a synchrotron hard X-ray interface scattering instrument for thein situdetection of work function variations resulting from X-ray irradiation is reported. First results, obtained on bare sapphire and sapphire covered by a room-temperature ionic liquid, are presented. In both cases a potential change was detected, which decayed and vanished after switching off the X-ray beam. This demonstrates the usefulness of a SKP forin situmonitoring of surface/interface potentials during X-ray materials characterization experiments.


Geophysics ◽  
1981 ◽  
Vol 46 (3) ◽  
pp. 322-332 ◽  
Author(s):  
James N. Lange ◽  
Steven S. Shope

The application of electromagnetic (EM) techniques to well logging is initiated in an environment dominated by the properties of the drilling fluids. An impulse technique using nanosecond pulses is applied to a coaxial waveguide containing drilling fluids to measure the velocity (dielectric constant ε) and absorption (attenuation coefficient α) of EM impulses. It is the large difference in dielectric constants of water and oil which makes EM propagation techniques attractive for logging. Dielectric properties of some nondispersed drilling fluids (bentonite and attapulgite clays) are found to be largely dependent upon the volume of water present. Both bentonite and attapulgite clays exhibit the same range of dielectric constants (ε = 81 → 75) when the weight percent of clay is increased to 10 percent. In contrast, the microwave attenuations of these two clays are quite different, with that of the bentonite increasing at about 4 times the rate of the attapulgite suspensions. Microwave attenuation measured for a variety of commercial drilling fluids varies over a wide range, with the lignosulfonates the largest (91 dB/m) and oil inverts the smallest (3 dB/m). The oil inverts also have a small dielectric constant (ε = 3 → 6). Temperature dependence of the attenuation for these same drilling fluids is determined in the range from 23 °C to 45 °C to indicate their behavior under in situ conditions.


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