講師：Prof. Gerald H. Pollack (Department of University of Washington, Seattle)
題目：The Secret Life of Water: E = H2O
School children learn that water has three phases: solid, liquid and vapor.
But we have recently uncovered what appears to be a fourth phase.
This phase occurs next to water-loving (hydrophilic) surfaces.
It is surprisingly extensive, projecting out from the surface by up to millions of molecular layers.
Of particular significance is the observation that this fourth phase is charged;
and, the water just beyond is oppositely charged, creating a battery that can produce current.
We found that light recharges this battery.
Thus, water can receive and process electromagnetic energy drawn from the environment - much like plants.
The absorbed light energy can then be exploited for performing work, including electrical and mechanical work.
Recent experiments confirm the reality of such energy conversion.
The energy-conversion framework implied above seems rich with implication.
Not only does it provide an understanding of how water processes solar and other energies,
but also it may provide a foundation for simpler understanding natural phenomena
ranging from weather and green energy all the way to biological issues such as the origin of life, transport, and osmosis.
The lecture will present evidence for the presence of this novel phase of water,
and will consider the potentially broad implications of this phase for physics, chemistry and biology, as well as some practical applications for engineering.
これらの集団運動には流体力学相互作用が重要な役割を果たしていると思われるがその機構は Taylor の先駆的研究から６０年が経つ今日なおよく理解されていない。
講師：伴 貴彦 氏（大阪大学大学院 基礎工学研究科 物質創成専攻 化学工学領域）
題目：Chemical control of droplet motion
We present three kinds of self-propelled droplets.
First type of droplet motion is induced by the change in surface energy of a substrate due to chemical dewetting phenomena.
The droplet exhibits two kinds of spontaneous motion: translational motion or oscillatory change in contact angle.
The motion depends on kind of anionic surfactant.
Second one is triggered by the change in interfacial energy in a liquid-liquid interface due to Marangoni effect.
When an oil droplet containing surfactant is formed in buffer solution, the droplet shows random walk or periodic pore formation.
The motion depends on pH of buffer solution and size of the droplet.
Third one is to use the interfacial energy generated under phase separation, i.e. Korteweg force.
The droplet behavior depends on the composition of the continuous phase:
for higher concentrations of the continuous phase than the equilibrium value,
the droplet moves unidirectionally even in a homogeneous concentration field with a constant radius,
whereas for lower concentrations, the droplet shrinks or deforms like a biological cell with moving.
We will discuss mechanism of the droplet behavior in comparison to theoretical study proposed by the other researchers.
講師：Professor Chwen-Yang Shew (Department of Chemistry College of Staten Island, City University of New York Staten Island)
題目：Theoretical studies of the spectra of spin echo small angle neutron scattering: Structure of simple fluids
It has been a great challenge to characterize aggregates and large particles with small angle neutron scattering
because scattering signals needed to unveil their structures appear at very small angles that require high resolution instruments to resolve scattering spectra.
Such an instrumental setup indeed causes tremendous signal losses and forbids accurate measurements.
To this end, a novel spin-echo small angle neutron scattering method (SESANS) based on polarized neutrons has been developed,
from which the spatial correlation between molecules in real space can be obtained.
The method provides a new means for characterization of aggregates or other large particles.
However, interpretation of SESANS data remains difficult due to its intrinsic mathematical complexities.
In this talk, I will briefly introduce our new algorithm for calculation of theoretical SESANS spectra by using computer simulations.
This algorithm is applicable to different particle geometries and interaction potentials,
and is rigorously tested with integral equation theory via hard-sphere liquid model.
Our simulations also show that the characteristic feature of SESANS spectra can be exploited to discern attractive and repulsive interaction between particles.
Furthermore, I will discuss about our recent model studies to elucidate the effect of particle interactions on the spectral features of SESANS
講師：Professor Helmut R. Brand (Theoretical Physics III, University Bayreuth, Germany)
題目：Macroscopic behavior of active systems with a dynamic preferred direction
We present the derivation of macroscopic equations for active systems with a dynamic preferred direction, which can be either axial or polar.
Such an approach is expected to be applicable and important for biological systems,
which have preferred directions only dynamically, but not permanently or in a static configuration.
For an axial preferred direction we introduce the time derivative of the local preferred direction
as a new variable and discuss its macroscopic consequences including new cross-coupling terms.
We investigate the coupling to a gel for which one has the strain tensor and relative rotations
between the new variable and the network as additional macroscopic variables.
For the case of a dynamic polar preferred direction the additional macroscopic variables transforms like a velocity under parity and time reversal.
This approach is expected to be useful for a number of biological systems including,
for example, the formation of dynamic macroscopic patterns shown by certain bacteria such as Proteus mirabilis.
I talk about glassy behaviors such as nonergodic transitions in kinetically constrained models (KCMs),
which are candidates of the systems exhibiting the universality of jamming transitions in athermal systems.
First, I review previous studies that KCMs on finite dimensional lattices have been proved to exhibit nonergodic transitions,
of which universality is determined by the critical natures of a conventional directed percolation.
Next, I introduce a KCM on the square lattice which also shows a nonergodic transition.
A notable point is that the universality class is different from that of previous models.
Finally, I discuss its relevance to jamming transitions in athermal systems.