On the response of neutrally stable flows to oscillatory forcing with application to liquid sheets

Industrial coating processes create thin liquid films with tight thickness tolerances, and thus models that predict the response to inevitable disturbances are essential. The mathematical modeling complexities are reduced through linearization as even small thickness variations in films can render a product unsalable. The signaling problem, considered in this paper, is perhaps the simplest model that incorporates the effects of repetitive (oscillatory) disturbances that are initiated, for example, by room vibrations and pump drives. In prior work, Gordillo and P\'erez (Phys. Fluids 14, 2002) examined the structure of the signaling response for linear operators that admit exponentially growing or damped solutions, i.e., the medium is classified as unstable or stable via classical stability analysis. The signaling problem admits two portions of the solution, the transient behavior due to the start-up of the disturbance and the long-time behavior that is continually forced; the superposition reveals how the forced solution evolves through the passage of a transient. In this paper, we examine signaling for the linear operator examined by King et al. (King et al. 2016, Phys. Rev. Fluids 1(7)) that governs varicose waves in a thin liquid sheet and that can admit solutions having algebraic growth although the underlying medium is classified as being neutrally stable. Long-time asymptotic methods are used to extract critical velocities that partition the response into distinct regions having markedly different location-dependent responses, and the amplitudes of oscillatory responses in these regions are determined. Together, these characterize the magnitude and breadth of the solution response. Results indicate that the signaling response in neutrally stable flows (that admit algebraic growth) is significantly different from that in exponentially unstable systems

The Grizzly, October 27, 1978

Bomberger Tower Razed • Homecoming Brings Crowning, Presentations • Self Study Continues • Hockey Ties Nation\u27s Best • No Tickets at Door • Campus Sunshine to Set? • Ravine Paradise Revisited • Portrait of the Professor: Randy Davidson • Letters to the Editor • Springsteen & Dylan: Poet Laureates or Veritable Zeroes? • Art is a Math is an Art is a Math... • Escher Takes On New Dimension • Commencement Speaker Announced • Plea From the Press • GM: Looking Good For \u2779 • Soccer Splits: 2-2 • Sports Profile: Don Paolicelli • Thin Clads Receive Treat • Swarthmore Superior In Homecoming Game • J.V.s Romp to Win • Hockey Returns Home • News in Brief: Fire Alarm Installations Near Completion; ProTheatre to Present The Good Doctor ; Art Exhibit to Open Soonhttps://digitalcommons.ursinus.edu/grizzlynews/1004/thumbnail.jp

The Grizzly, October 27, 1978

Bomberger Tower Razed • Homecoming Brings Crowning, Presentations • Self Study Continues • Hockey Ties Nation\u27s Best • No Tickets at Door • Campus Sunshine to Set? • Ravine Paradise Revisited • Portrait of the Professor: Randy Davidson • Letters to the Editor • Springsteen & Dylan: Poet Laureates or Veritable Zeroes? • Art is a Math is an Art is a Math... • Escher Takes On New Dimension • Commencement Speaker Announced • Plea From the Press • GM: Looking Good For \u2779 • Soccer Splits: 2-2 • Sports Profile: Don Paolicelli • Thin Clads Receive Treat • Swarthmore Superior In Homecoming Game • J.V.s Romp to Win • Hockey Returns Home • News in Brief: Fire Alarm Installations Near Completion; ProTheatre to Present The Good Doctor ; Art Exhibit to Open Soonhttps://digitalcommons.ursinus.edu/grizzlynews/1004/thumbnail.jp

Multifragmentation of a very heavy nuclear system (I): Selection of single-source events

A sample of `single-source' events, compatible with the multifragmentation of very heavy fused systems, are isolated among well-measured 155Gd+natU 36AMeV reactions by examining the evolution of the kinematics of fragments with Z>=5 as a function of the dissipated energy and loss of memory of the entrance channel. Single-source events are found to be the result of very central collisions. Such central collisions may also lead to multiple fragment emission due to the decay of excited projectile- and target-like nuclei and so-called `neck' emission, and for this reason the isolation of single-source events is very difficult. Event-selection criteria based on centrality of collisions, or on the isotropy of the emitted fragments in each event, are found to be inefficient to separate the two mechanisms, unless they take into account the redistribution of fragments' kinetic energies into directions perpendicular to the beam axis. The selected events are good candidates to look for bulk effects in the multifragmentation process.Comment: 39 pages including 15 figures; submitted to Nucl. Phys.

Functionals of the Brownian motion, localization and metric graphs

We review several results related to the problem of a quantum particle in a random environment. In an introductory part, we recall how several functionals of the Brownian motion arise in the study of electronic transport in weakly disordered metals (weak localization). Two aspects of the physics of the one-dimensional strong localization are reviewed : some properties of the scattering by a random potential (time delay distribution) and a study of the spectrum of a random potential on a bounded domain (the extreme value statistics of the eigenvalues). Then we mention several results concerning the diffusion on graphs, and more generally the spectral properties of the Schr\"odinger operator on graphs. The interest of spectral determinants as generating functions characterizing the diffusion on graphs is illustrated. Finally, we consider a two-dimensional model of a charged particle coupled to the random magnetic field due to magnetic vortices. We recall the connection between spectral properties of this model and winding functionals of the planar Brownian motion.Comment: Review article. 50 pages, 21 eps figures. Version 2: section 5.5 and conclusion added. Several references adde

The Main Belt Comets and ice in the Solar System

We review the evidence for buried ice in the asteroid belt; specifically the questions around the so-called Main Belt Comets (MBCs). We summarise the evidence for water throughout the Solar System, and describe the various methods for detecting it, including remote sensing from ultraviolet to radio wavelengths. We review progress in the first decade of study of MBCs, including observations, modelling of ice survival, and discussion on their origins. We then look at which methods will likely be most effective for further progress, including the key challenge of direct detection of (escaping) water in these bodies

Gene expression profiling of mucinous ovarian tumors and comparison with upper and lower gastrointestinal tumors identifies markers associated with adverse outcomes.

PURPOSE: Advanced-stage mucinous ovarian carcinoma (MOC) has poor chemotherapy response and prognosis and lacks biomarkers to aid stage I adjuvant treatment. Differentiating primary MOC from gastrointestinal (GI) metastases to the ovary is also challenging due to phenotypic similarities. Clinicopathologic and gene-expression data were analyzed to identify prognostic and diagnostic features. EXPERIMENTAL DESIGN: Discovery analyses selected 19 genes with prognostic/diagnostic potential. Validation was performed through the Ovarian Tumor Tissue Analysis consortium and GI cancer biobanks comprising 604 patients with MOC (n = 333), mucinous borderline ovarian tumors (MBOT, n = 151), and upper GI (n = 65) and lower GI tumors (n = 55). RESULTS: Infiltrative pattern of invasion was associated with decreased overall survival (OS) within 2 years from diagnosis, compared with expansile pattern in stage I MOC [hazard ratio (HR), 2.77; 95% confidence interval (CI), 1.04–7.41, P = 0.042]. Increased expression of THBS2 and TAGLN was associated with shorter OS in MOC patients (HR, 1.25; 95% CI, 1.04–1.51, P = 0.016) and (HR, 1.21; 95% CI, 1.01–1.45, P = 0.043), respectively. ERBB2 (HER2) amplification or high mRNA expression was evident in 64 of 243 (26%) of MOCs, but only 8 of 243 (3%) were also infiltrative (4/39, 10%) or stage III/IV (4/31, 13%). CONCLUSIONS: An infiltrative growth pattern infers poor prognosis within 2 years from diagnosis and may help select stage I patients for adjuvant therapy. High expression of THBS2 and TAGLN in MOC confers an adverse prognosis and is upregulated in the infiltrative subtype, which warrants further investigation. Anti-HER2 therapy should be investigated in a subset of patients. MOC samples clustered with upper GI, yet markers to differentiate these entities remain elusive, suggesting similar underlying biology and shared treatment strategies