Reentrant Adhesion Behavior in Nanocluster Deposition

We simulate the collision of atomic clusters with a weakly attractive surface using molecular dynamics in a regime between soft-landing and fragmentation, where the cluster undergoes large deformation but remains intact. As a function of incident kinetic energy, we find a transition from adhesion to reflection at low kinetic energies. We also identify a second adhesive regime at intermediate kinetic energies, where strong deformation of the cluster leads to an increase in contact area and adhesive energy.Comment: 7 pages, 6 figure

Solid-liquid phase coexistence and structural transitions in palladium clusters

We use molecular dynamics with an embedded atom potential to study the behavior of palladium nanoclusters near the melting point in the microcanonical ensemble. We see transitions from both fcc and decahedral ground state structures to icosahedral structures prior to melting over a range of cluster sizes. In all cases this transition occurs during solid-liquid phase coexistence and the mechanism for the transition appears to be fluctuations in the molten fraction of the cluster and subsequent recrystallization into the icosahedral structure.Comment: 8 pages, 6 figure

Molecular dynamics simulations of reflection and adhesion behavior in Lennard-Jones cluster deposition

We conduct molecular dynamics simulations of the collision of atomic clusters with a weakly-attractive surface. We focus on an intermediate regime, between soft-landing and fragmentation, where the cluster undergoes deformation on impact but remains largely intact, and will either adhere to the surface (and possibly slide), or be reflected. We find that the outcome of the collision is determined by the Weber number, We i.e. the ratio of the kinetic energy to the adhesion energy, with a transition between adhesion and reflection occurring as We passes through unity. We also identify two distinct collision regimes: in one regime the collision is largely elastic and deformation of the cluster is relatively small but in the second regime the deformation is large and the adhesion energy starts to depend on the kinetic energy. If the transition between these two regimes occurs at a similar kinetic energy to that of the transition between reflection and adhesion, then we find that the probability of adhesion for a cluster can be bimodal. In addition we investigate the effects of the angle of incidence on adhesion and reflection. Finally we compare our findings both with recent experimental results and with macroscopic theories of particle collisions.Comment: 18 pages, 13 figure

A theological aim historical assessment of the Christology of Nestorius in the context of his times

The Patriarch Nestorius was condemned as an heretic at the Councils of Ephosus and Chalcedon. During the last century, following the rediscovery of many of his writings, several important scholars have examined his case. Their conclusions have varied considerably; on the whole they have been too kind to him. This thesis begins by examining the life of Nestorius to put the controversies in context. In particular, the question of whether he was still alive at the time of Chalcedon is examined; also the length of tine he spent in exile. Certainly he was alive until shortly before the Council met, but that is all we can say with certainly. Following this discussion, the historical reasons for the condemnation of Nestorius are treated. The political and sociological controversies between Alexandria, Constantinople, Rome, Antioch and Jerusalem are examined, together with the differences between the Antiochene and Alexandrian schools of theology. Personality and group conflicts no doubt played their part, but could not have led to Nestorius' condemnation on their own. A major section of the thesis is concerred with the Christology of the main theological schools. Their concepts are examined and the variations among individual representatives of the Antiochene school particularly are examined. All this helps to set Nestorius' work in context. After a short critical chapter on the literary Mstory of Nestorius' writings, including references to Abramowski's recent work on a dual-authorship hypothesis of the Book of Heracleides, we turn to Nestorius' own thought and vocabulary. The conclusion reached suggests that although Nestorius' intentions were good, and that he rendered good service by safeguarding the humanity of Christ, be ended up in a cul-de-sac, when it came to establishing the unity of Christ's person in the Prosopon. We also conclude that the Book of Heracleides did little or nothing to help his case