24 research outputs found
Lifting up to Himself: John Calvin's Doctrine of the Trinity and Its Implications for the Lord's Supper and Worship
This study probes the eucharistic implications of the doctrine of the Trinity in the theology of John Calvin (1509-1564). Calvin scholarship has established that the doctrine of the Trinity is the key paradigm of divine-human relationship in Calvin鈥檚 theology. Drawing upon this, this study explores how the doctrine affects Calvin鈥檚 concept of divine-human interplay in worship and the Lord鈥檚 Supper, and how it has liturgical implications for both disciplines. After a reflection on the connection between the doctrine of the Trinity and worship and the sacraments in Calvin鈥檚 thought, this thesis shows that the doctrine of the Trinity is an underpinning paradigm for Calvin鈥檚 distinctive understanding of the Lord鈥檚 Supper as a heavenly communion, a concept by which a personal, experiential, and dynamic, nature of eucharistic communion is highlighted. It also provides surveys of the meaning of the eucharistic heaven, and of the actual mode of the heavenly communion in the ministry of the church, along with a consideration of how this Trinitarian doctrine of the Lord鈥檚 Supper distinguishes Calvin鈥檚 liturgical thought and practice from those of other reformers. From these surveys it is concluded that the doctrine of the Trinity is the essence of Calvin鈥檚 theology and practice of the eucharist
Nanoscale spectroscopic studies of two different physical origins of the tip-enhanced force: dipole and thermal
When light illuminates the junction formed between a sharp metal tip and a
sample, different mechanisms can con-tribute to the measured photo-induced
force simultaneously. Of particular interest are the instantaneous force
be-tween the induced dipoles in the tip and in the sample and the force related
to thermal heating of the junction. A key difference between these two force
mechanisms is their spectral behaviors. The magnitude of the thermal response
follows a dissipative Lorentzian lineshape, which measures the heat exchange
between light and matter, while the induced dipole response exhibits a
dispersive spectrum and relates to the real part of the material
polarizability. Be-cause the two interactions are sometimes comparable in
magnitude, the origin of the nanoscale chemical selectivity in the recently
developed photo-induced force microscopy (PiFM) is often unclear. Here, we
demonstrate theoretically and experimentally how light absorption followed by
nanoscale thermal expansion generates a photo-induced force in PiFM.
Furthermore, we explain how this thermal force can be distinguished from the
induced dipole force by tuning the relaxation time of samples. Our analysis
presented here helps the interpretation of nanoscale chemical measure-ments of
heterogeneous materials and sheds light on the nature of light-matter coupling
in van der Waals materials.Comment: 17 pages, 10 figure
Quantification of titanium dioxide (TiO2) anatase and rutile polymorphs in binary mixtures by Raman spectroscopy: an interlaboratory comparison
This article presents an interlaboratory comparison (ILC) on Raman spectroscopy as a technique for relative quantification of the two most common polymorphs of titanium dioxide (TiO2)-anatase and rutile-in binary mixtures. Some standard methods are currently employed internationally for the determination of TiO2 content in samples (ISO 591-1, ASTM D3720-90), but require extensive sample preparation, do not distinguish between the two polymorphs or are accurate only for small fractions of either polymorph. Raman spectroscopy is a well-suited characterization technique for measuring and differentiating TiO2 in a fast, non-invasive way, while requiring no particular reagent or sample preparation. Eleven international participants conducted the study under the framework of Versailles Project on Advanced Materials and Standards. The collected data was analyzed by means of partial least squares regression after spectral preprocessing. The resulting models all show discrepancies of lower than 2% from the nominal values in the quantitative analysis over the concentration range of 5%-95% mixture fractions, with many datasets showing substantial improvement margins on this figure. The results of this ILC provide validation of Raman spectroscopy as a reliable method for quantification of TiO2 phases
Photo-Induced Force Microscopy by Using Quartz Tuning-Fork Sensor
We present the photo-induced force microscopy (PiFM) studies of various nano-materials by implementing a quartz tuning fork (QTF), a self-sensing sensor that does not require complex optics to detect the motion of a force probe and thus helps to compactly configure the nanoscale optical mapping tool. The bimodal atomic force microscopy technique combined with a sideband coupling scheme is exploited for the high-sensitivity imaging of the QTF-PiFM. We measured the photo-induced force images of nano-clusters of Silicon 2,3-naphthalocyanine bis dye and thin graphene film and found that the QTF-PiFM is capable of high-spatial-resolution nano-optical imaging with a good signal-to-noise ratio. Applying the QTF-PiFM to various experimental conditions will open new opportunities for the spectroscopic visualization and substructure characterization of a vast variety of nano-materials from semiconducting devices to polymer thin films to sensitive measurements of single molecules
Fabrication of Al-Ni Alloys for Fast Hydrogen Production from Hydrolysis in Alkaline Water
Hydrogen generation through the hydrolysis of aluminum alloys has attracted significant attention because it generates hydrogen directly from alkaline water without the need for hydrogen storage technology. The hydrogen generation rate from the hydrolysis of aluminum in alkaline water is linearly proportional to its corrosion rate. To accelerate the corrosion rate of the aluminum alloy, we designed Al-Ni alloys by continuously precipitating an electrochemically noble Al3Ni phase along the grain boundaries. The Al-0.5~1 wt.% Ni alloys showed an excellent hydrogen generation rate of 16.6 mL/cm2路min, which is about 6.4 times faster than that of pure Al (2.58 mL/cm2路min). This excellent performance was achieved through the synergistic effects of galvanic and intergranular corrosion on the hydrolysis of Al. By raising the solution temperature to 50 掳C, the optimal rate of hydrogen generation of Al-1 wt.% Ni in 10 wt.% NaOH solutions at 30 掳C can be further increased to 54.5 mL/cm2路min
Interfacial-Water-Modulated Photoluminescence of Single-Layer WS<sub>2</sub> on Mica
Because of their bandgap tunability and strong light鈥搈atter interactions, two-dimensional (2D) semiconductors are considered promising candidates for next-generation optoelectronic devices. However, their photophysical properties are greatly affected by their surrounding environment because of their 2D nature. In this work, we report that the photoluminescence (PL) of single-layer WS2 is substantially affected by interfacial water that is inevitably present between it and the supporting mica substrates. Using PL spectroscopy and wide-field imaging, we show that the emission signals from A excitons and their negative trions decreased at distinctively different rates with increasing excitation power, which could be attributed to the more efficient annihilation between excitons than between trions. By gas-controlled PL imaging, we also prove that the interfacial water converted the trions into excitons by depleting native negative charges through an oxygen reduction reaction, which rendered the excited WS2 more susceptible to nonradiative decay via exciton鈥揺xciton annihilation. Understanding the role of nanoscopic water in complex low-dimensional materials will eventually contribute to devising their novel functions and related devices
3D Porous Cobalt鈥揑ron鈥揚hosphorus Bifunctional Electrocatalyst for the Oxygen and Hydrogen Evolution Reactions
A 3D porous Co鈥揊e鈥揚
foam fabricated using electrodeposition
is presented as a high-performance and durable catalyst for both oxygen
and hydrogen evolution reactions. To establish optimal Fe/Co ratio
of the catalyst, Co鈥揊e鈥揚 films were electrodeposited
with Fe/Co ratio of 0.2, 0.4, 1.1, and 3.3. Among the prepared samples,
the Co鈥揊e鈥揚 film with the Fe/Co ratio of 1.1 (Co鈥揊e鈥揚-1.1)
exhibited the highest activity for the oxygen evolution reaction,
which could be attributed to the transfer of the valence electron
from Co to Fe and P. To improve performance of the Co鈥揊e鈥揚-1.1,
a 3D porous foam structure was adopted using the electrodeposition.
The Co鈥揊e鈥揚 foam had 94 times larger electrochemical
active surface area (ECSA) than the Co鈥揊e鈥揚 film with
similar Fe/Co ratios of 1.1, resulting in an distinguished activity
for the oxygen evolution reaction (294 mV at 10 mA/cm<sup>2</sup>)
and hydrogen evolution reaction (73 mV at 10 mA/cm<sup>2</sup>) in
an alkaline solution. Since the electrodeposited Co鈥揊e鈥揚
foam itself can be directly used as an electrode, it is free from
binders, and microstructure of the electrode can be engineered by
controlling the electrodeposition condition, leading to the enlarged
ECSA and improved performance. Thus, the Co鈥揊e鈥揚 foam
presented in this study offers a facile and controllable synthesis
of catalyst and electrode through an easy electrodeposition process
Delayed Triplet-State Formation through Hybrid Charge Transfer Exciton at Copper Phthalocyanine/GaAs Heterojunction
Light
absorption in organic molecules on an inorganic substrate
and subsequent electron transfer to the substrate create so-called
hybrid charge transfer exciton (HCTE). The relaxation process of the
HCTE states largely determines charge separation efficiency or optoelectronic
device performance. Here, the study on energy and time-dispersive
behavior of photoelectrons at the hybrid interface of copper phthalocyanine
(CuPc)/<i>p</i>-GaAs颅(001) upon light excitation of GaAs
reveals a clear pathway for HCTE relaxation and delayed triplet-state
formation. According to the ground-state energy level alignment at
the interface, CuPc/<i>p</i>-GaAs颅(001) shows initially fast
hole injection from GaAs to CuPc. Thus, the electrons in GaAs and
holes in CuPc form an unusual HCTE state manifold. Subsequent electron
transfer from GaAs to CuPc generates the formation of the triplet
state in CuPc with a few picoseconds delay. Such two-step charge transfer
causes delayed triplet-state formation without singlet excitation
and subsequent intersystem crossing within the CuPc molecules