Tel Anafa : The 1981 Season

"The summer of 1981 saw the joint University of Missouri / University of Michigan team back in the field at Tel Anafa for nine more weeks of excavation at this rich Hellenistic settlement in the Upper Galilee of Israel. The 1981 season was the final season of the current series, which has concentrated on the Hellenistic and Roman levels of the tel. Preparatory to final publication, the principal goals of this last season were the verification of certain assumptions on which the restoration of the plan of the large Late Hellenistic stuccoed building (hereafter the LHSB) is based, and the clarification of the occupation phases and remodelings of that building. Specifically, we had four major questions about the LHSB: (1) the extent of the hitherto unexplored western sector; (2) the relationship between the luxurious stuccoed room at the northeast corner of the central court and the heating and drainage system some five meters to its south; (3) the function of the central court; (4) the extent of the building in the northeast."--First paragraph.Includes bibliographical reference

Tel Anafa 1980

"The joint University of Missouri / University of Michigan expedition returned to Tel Anafa in the Upper Galilee of Israel for two more months of excavation in the summer of 1980. In this eighth season of excavation at the site we continued to concentrate our efforts on the Graeco-Roman levels of the mound, uncovering more of the Hellenistic stuccoed building which occupies much of the northern sector of the tel. The work in 1980 revealed more of the complex history and plan of this important building and brought to light some of the most impressive finds yet unearthed at Tel Anafa."--First paragraph.Includes bibliographical reference

New Campaign at Tel Anafa 1978

"The mound in Upper Galilee, now known as Tel Anafa -- the Mound of the Heron -- was an ancient settlement of some importance on the trade route between Tyre and Damascus. Its ancient name has not yet been ascertained. Here excavations were carried on by the University of Missouri's Museum of Art and Archaeology from 1968-73. The results were extremely fruitful."--First paragraph.Includes bibliographical reference

Tel Anafa 1979

"The new series of excavations at Tel Anafa in Upper Galilee, Israel, continued with an eight-week season in the summer of 1979 under the joint sponsorship of the University of Missouri's Museum of Art and Archaeology and the Kelsey Museum of the University of Michigan. The site, located near the crossroads of the ancient trans-desert trade route from the East to the Mediterranean with the north-south route up the Jordan rift, flourished from the Early Bronze Age through the Early Roman period. Five previous seasons of excavation by the University of Missouri Museum have unearthed rich remains of these three millennia of occupation. In 1979 we concentrated our work on the Early Roman and Hellenistic levels, seeking to clarify the plan and function of the large and elaborately stuccoed Late Hellenistic building (150-80 B.C.) which dominates the northeast quadrant of the tel, and to ascertain the extent and nature of the first century A.O. re-use of the area. The results of the 1979 season provided much new information on both these periods of occupation and as usual produced some stratigraphical surprises and new questions about the ancient inhabitants of Tel Anafa."--First paragraph.Includes bibliographical reference

Does the continuum theory of dynamic fracture work?

We investigate the validity of the Linear Elastic Fracture Mechanics approach to dynamic fracture. We first test the predictions in a lattice simulation, using a formula of Eshelby for the time-dependent Stress Intensity Factor. Excellent agreement with the theory is found. We then use the same method to analyze the experiment of Sharon and Fineberg. The data here is not consistent with the theoretical expectation.Comment: 4 page

Arrested Cracks in Nonlinear Lattice Models of Brittle Fracture

We generalize lattice models of brittle fracture to arbitrary nonlinear force laws and study the existence of arrested semi-infinite cracks. Unlike what is seen in the discontinuous case studied to date, the range in driving displacement for which these arrested cracks exist is very small. Also, our results indicate that small changes in the vicinity of the crack tip can have an extremely large effect on arrested cracks. Finally, we briefly discuss the possible relevance of our findings to recent experiments.Comment: submitted to PRE, Rapid Communication

Steady-State Cracks in Viscoelastic Lattice Models

We study the steady-state motion of mode III cracks propagating on a lattice exhibiting viscoelastic dynamics. The introduction of a Kelvin viscosity $\eta$ allows for a direct comparison between lattice results and continuum treatments. Utilizing both numerical and analytical (Wiener-Hopf) techniques, we explore this comparison as a function of the driving displacement $\Delta$ and the number of transverse sites $N$. At any $N$, the continuum theory misses the lattice-trapping phenomenon; this is well-known, but the introduction of $\eta$ introduces some new twists. More importantly, for large $N$ even at large $\Delta$, the standard two-dimensional elastodynamics approach completely misses the $\eta$-dependent velocity selection, as this selection disappears completely in the leading order naive continuum limit of the lattice problem.Comment: 27 pages, 8 figure

A photometric search for transients in galaxy clusters

We have begun a program to search for supernovae and other transients in the fields of galaxy clusters with the 2.3m Bok Telescope on Kitt Peak. We present our automated photometric methods for data reduction, efficiency characterization, and initial spectroscopy. With this program, we aim to ultimately identify $\sim$25-35 cluster SN Ia ($\sim$10 of which will be intracluster, hostless events) and constrain the SN Ia rate associated with old, passive stellar populations. With these measurements we will constrain the relative contribution of hostless and hosted SN Ia to the metal enrichment of the intracluster medium. In the current work, we have identified a central excess of transient events within $1.25 r_{200}$ in our cluster fields after statistically subtracting out the 'background' transient rate taken from an off-cluster CCD chip. Based on the published rate of SN Ia for cluster populations we estimate that $\sim$20 percent of the excess cluster transients are due to cluster SN Ia, a comparable fraction to core collapse (CC) supernovae and the remaining are likely to be active galactic nuclei. Interestingly, we have identified three intracluster SN candidates, all of which lay beyond $R>r_{200}$. These events, if truly associated with the cluster, indicate a large deficit of intracluster (IC) SN at smaller radii, and may be associated with the IC stars of infalling groups or indicate that the intracluster light (ICL) in the cluster outskirts is actively forming stars which contribute CC SN or prompt SN Ia.Comment: Updated to match accepted version; 26 pages, 14 figures, AJ accepte

Nonlinear lattice model of viscoelastic Mode III fracture

We study the effect of general nonlinear force laws in viscoelastic lattice models of fracture, focusing on the existence and stability of steady-state Mode III cracks. We show that the hysteretic behavior at small driving is very sensitive to the smoothness of the force law. At large driving, we find a Hopf bifurcation to a straight crack whose velocity is periodic in time. The frequency of the unstable bifurcating mode depends on the smoothness of the potential, but is very close to an exact period-doubling instability. Slightly above the onset of the instability, the system settles into a exactly period-doubled state, presumably connected to the aforementioned bifurcation structure. We explicitly solve for this new state and map out its velocity-driving relation