3,940 research outputs found
Chen ranks and resonance
The Chen groups of a group are the lower central series quotients of the
maximal metabelian quotient of . Under certain conditions, we relate the
ranks of the Chen groups to the first resonance variety of , a jump locus
for the cohomology of . In the case where is the fundamental group of
the complement of a complex hyperplane arrangement, our results positively
resolve Suciu's Chen ranks conjecture. We obtain explicit formulas for the Chen
ranks of a number of groups of broad interest, including pure Artin groups
associated to Coxeter groups, and the group of basis-conjugating automorphisms
of a finitely generated free group.Comment: final version, to appear in Advances in Mathematic
Material characterization of structural adhesives in the lap shear mode
A general method for characterizing structual adhesives in the bonded lap shear mode is proposed. Two approaches in the form of semiempirical and theoretical approaches are used. The semiempirical approach includes Ludwik's and Zhurkov's equations to describe respectively, the failure stresses in the constant strain rate and constant stress loading modes with the inclusion of the temperature effects. The theoretical approach is used to describe adhesive shear stress-strain behavior with the use of viscoelastic or nonlinear elastic constitutive equations. Two different model adhesives are used in the single lap shear mode with titanium adherends. These adhesives (one of which was developed at NASA Langley Research Center) are currently considered by NASA for possible aerospace applications. Use of different model adhesives helps in assessment of the generality of the method
Remembering African Labor Migration to the Second World
This open access book is about Mozambicans and Angolans who migrated in state-sponsored schemes to East Germany in the late 1970s and throughout the 1980s. They went to work and to be trained as a vanguard labor force for the intended African industrial revolutions. While they were there, they contributed their labor power to the East German economy. This book draws on more than 260 life history interviews and uncovers complex and contradictory experiences and transnational encounters. What emerges is a series of dualities that exist side by side in the memories of the former migrants: the state and the individual, work and consumption, integration and exclusion, loss and gain, and the past in the past and the past in the present and future. By uncovering these dualities, the book explores the lives of African migrants moving between the Third and Second worlds. Devoted to the memories of worker-trainees, this transnational study comes at a time when historians are uncovering the many varied, complicated, and important connections within the global socialist world
Muon spin rotation and relaxation in the superconducting ferromagnet UCoGe
We report zero-field muon spin rotation and relaxation measurements on the
superconducting ferromagnet UCoGe. Weak itinerant ferromagnetic order is
detected by a spontaneous muon spin precession frequency below the Curie
temperature K. The precession frequency persists below the
bulk superconducting transition temperature K, where it measures
a local magnetic field T. The amplitude of the SR signal
provides unambiguous proof for ferromagnetism present in the whole sample
volume. We conclude ferromagnetism coexists with superconductivity on the
microscopic scale.Comment: 4 pages, 3 figures, accepted for publication in PR
Remembering African Labor Migration to the Second World
This open access book is about Mozambicans and Angolans who migrated in state-sponsored schemes to East Germany in the late 1970s and throughout the 1980s. They went to work and to be trained as a vanguard labor force for the intended African industrial revolutions. While they were there, they contributed their labor power to the East German economy. This book draws on more than 260 life history interviews and uncovers complex and contradictory experiences and transnational encounters. What emerges is a series of dualities that exist side by side in the memories of the former migrants: the state and the individual, work and consumption, integration and exclusion, loss and gain, and the past in the past and the past in the present and future. By uncovering these dualities, the book explores the lives of African migrants moving between the Third and Second worlds. Devoted to the memories of worker-trainees, this transnational study comes at a time when historians are uncovering the many varied, complicated, and important connections within the global socialist world
Letter from C. Alwin Schenck to John Muir, 1899 Jan 16.
FOREST DEPARTMENT,BILTMORE ESTATE,C. A. SCHENCK, FORESTER,BILTMORE,N.O.January 16,1899.Mr.John Muir,Martinez,Cal.My Dear Mr. Muir:I am greatly indebted for the copy of The Mountains of California recently sent to me.The book will certainly increase in me the avidity of seeing and studying those mountains personally.I hope good luck will favor me in my endeavors to take a trip out west.I am glad to know that your trip to Florida etc. in the company of Prof. Sargent continued to be pleasant.I would have given a great deal to have been able to accompany you on such an instructive expedition, although,perhaps,there was a little too much botany in it for my digestion.I have recently written to the Secy.of the Sierra Club, not knowing your vital connection with it, relative to the bulletins of the club which I thought were full of forestry interests. I find,however,that they are largely devoted to other purposes and do not think it necessary for that reason to join the sierra Club as I would have done otherwise.Hoping that the year just commenced will have good health in store for you,Very faithfully yours,[illegible]0253
Critical slowing down near the multiferroic phase transition in MnWO
By using broadband dielectric spectroscopy in the radiofrequency and
microwave range we studied the magnetoelectric dynamics in the multiferroic
chiral antiferromagnet MnWO. Above the multiferroic phase transition at
K we observe a critical slowing down of the corresponding
magnetoelectric fluctuations resembling the soft-mode behavior in canonical
ferroelectrics. This electric field driven excitation carries much less
spectral weight than ordinary phonon modes. Also the critical slowing down of
this mode scales with an exponent larger than one which is expected for
magnetic second order phase transition scenarios. Therefore the investigated
dynamics have to be interpreted as the softening of an electrically active
magnetic excitation, an electromagnon.Comment: 5 pages, 4 figures, appendi
Letter from Robert C. Schenck to James B. Finley
Schenck (U.S. Congressman, 3rd district, Ohio) responds to Finley\u27s query concerning a possible vacancy at the Eaton Post Office. He assures Finley that he is a valued friend and one of the best of the Whigs. However, a vacancy at the Eaton Post Office will likely be filled by the Postmaster General following the wishes of the citizens. At this time, there is no vacancy. The present postmaster, Mr. Campbell, is well liked. Schenck has received several letters from citizens hoping that Campbell will not be removed. Abstract Number - 434https://digitalcommons.owu.edu/finley-letters/1632/thumbnail.jp
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