412 research outputs found
Citron istället för kemikalier
No full textMarie-Louise Danielsson-Tham, veterinär, professor och städexpert. Känd från TV och gillar ordning och reda. Här tipsar hon om avfallsminimering och om att städa snabbt och effektivt utan kemikalier. TEXT: Ulrika Sahlin. FOTO: Carl-Johan Söder</p
Bakterierna på menyn
No full textEfter förra årets larm i livsmedelsindustrin skärskådar nu restaurangerna noggrannare. RS träffar Marie-Louise Danielsson-Tham, en auktoritet på bakterier, och diskuterar den mikroskopiska tillvarons villkor.</p
Accelerated Universes from type IIA Compactifications
No full textWe study slow-roll accelerating cosmologies arising from geometric compactifications of type IIA string theory on T^6/(Z_2 x Z_2). With the aid of a genetic algorithm, we are able to find quasi-de Sitter backgrounds with both slow-roll parameters of order 0.
Fully stable dS vacua from generalised fluxes
No full textWe investigate the possible existence of (meta-)stable de Sitter vacua within
= 1 compactificationswithgeneralisedfluxes. Withtheaidofanalgorithminspiredby the method of differential evolution, we were able to find three novel examples of completely tachyon-free de Sitter extrema in a non-isotropic type IIB model with non-geometric fluxes. We also analyse the surroundings of the aforementioned points in parameter space and chart the corresponding stability regions. These happen to occur at small values of the cosmological constant compared to the AdS scale
Constructing stable de Sitter in M-theory from higher curvature corrections
No full textWe consider dimensional reductions of M-theory on T-7/Z(2)(3) with the inclusion of arbitrary metric flux and spacetime filling KK monopoles. With these ingredients at hand, we are able to construct a novel family of non-supersymmetric yet tachyon free Minkowski extrema. These solutions are supported by pure geometry with no extra need for gauge fluxes and possess a fully stable perturbative mass spectrum, up to a single flat direction. Such a direction corresponds to the overall internal volume, with respect to which the scalar potential exhibits a no-scale behavior. We then provide a mechanism that lifts the flat direction to give it a positive squared mass while turning Mkw(4) into dS(4). The construction makes use of the combined effect of G(7) flux and higher curvature corrections. Our solution is scale separated and the quantum corrections are small. Finally we speculate on novel possibilities when it comes to scale hierarchies within a given construction of this type, and possible issues with the choice of quantum vacuum
Concurrent Constraint Programming at SICS with the Andorra Kernel Language (Extended Abstract)
No full text) Seif Haridi Sverker Janson Johan Montelius Torkel Franz'en Per Brand Kent Boortz Bjorn Danielsson Bjorn Carlson Torbjorn Keisu Dan Sahlin Thomas Sjoland SICS, Box 1263, S-164 28 KISTA Tel +46-8-752 15 00, Fax +46-8-751 72 30 E-mail fseif, [email protected] Abstract SICS is investigating a new generation of languages for symbolic processing that are based on the paradigm of concurrent constraint programming. A wide range of pertinent topics are being studied. In particular our efforts are devoted to producing a high quality programming environment based on the Andorra Kernel Language (AKL), a general purpose concurrent constraint language. 1 Introduction Concurrent constraint programming (CCP) is a powerful paradigm for programming with constraints while being based on simple concepts [9, 11]. A set (or conjunction) of constraints, regarded as formulas in firstorder logic, forms a constraint store. A number of agents interact with the store using the two operations tell, which adds..
You suggested at that time, art was not necessarily work made for a general public, but more like a gang of friends
No full textKatalog, avgangsutstilling, BA Kunstakademiet 2014.
Avgangsstudenter: Ina Hagen, Camilla Aas, Carl Mannov, Ksenia Aksenova, Urd J. Pedersen, Daisuke Kosugi, Thomas Bergsten, Øyvind Johansen Lind, Endre Mathistad, Titus Boguslaw, Christoffer Danielsson, Daniel Lacey-McDermott, Endre Opheim, Helena Lund Ek, Johan Carlsson, Jonathan Terry, Kim Groustra, Calle Segelberg, Linda Kristin Røed, Sigbjørn Pilskog. Kurator: Rachel E. Dagnall
Design method for strut-beam connection in hinged frames
No full textGlulam is almost exclusively the chosen material of timber frame structures. Of
those, three-hinged (three-pin) portal frames are incomparably the most common
type. Being both statically determinate and stable against horizontal forces
in its own plane o er both practical (basic constructive details) and economical
bene ts.
The design of the haunch allows for various solutions: it can be curved with
continuous laminates, nger jointed, jointed with steel dowels and slotted-in
plates, or built-up with a strut.
The form of the frame derives from the main load's force line. The most appropriate
forms for large spans are curved or built-up haunches, as they ful l
both functional and aesthetic aspects. Three-pin portal frames are suitable for
spans up to 30-40 meters, being the limiting factor the transport feasability of
the frame's halves.
In recent years a handful of three-hinged structures with built-up haunches
have collapsed, leaving behind a need to analyse and study the stresses and
resistance of this structures. For obvious reasons it is specially interesting to
research and clarify the fracture risk on the built-up haunches as well as to map
the stresses created by the inner frame leg through compression to the lower
edge of the frame rafter.
Today there is only one general method used to design built-up haunches,
present in both the Glulam Handbook and the German Institute for Standardization,
DIN, which is based on established practice. Both standards share similar
simpli cations and assumtions, giving surprisingly little importance to the
shear stress that occurs in the contact area of the built-up haunch.
The aim of this master's thesis was to put together a tool, in form of a
diagram, to help design the built-up haunch, with particular emphasis on the
contact area between the inner frame leg and the frame rafter, and the subsequent
shear stresses this contact creates on the rafter. To achieve this result a
sample frame rafter was calculated using 2D frame software and generic loads
and materials. The section forces obtained were then used to create a FEM
model of the built-up haunch.
This FEM model provided a clearer understanding of the behaviour of the frame
leg-frame rafter's contact area as well as yielding a map of the shear stresses
present in the joint. Finally with the use of Linear Elastic Fracture Mechanics
and the mean stress criterion a diagram-tool was created.
This report yielded two results that may be deemed of special interest:
- Both the Glulam Handbook and the german DIN standard relegate the
shear stress in the notch as merely a design checkout, never a design factor.
- Both the Glulam Handbook and the DIN completely disregard the size
e ects in the capacity of birdmouth joints. The fracture mechanics calculations presented in this report provide prove of strong size e ects, so
that current design standards signi cantly overestimate the capacity of
great-sized built-up haunches.
This conclusion could be important in practical terms, and should be
further investigated. Experimental tests should also be inlcuded in future
research.
Keywords: glulam, built-up haunches, framed joint, three-pin portal frames,
shear stress, failure modes, LEFM, ABAQUS, size e ects.Outgoin
Design method for strut-beam connection in hinged frames
No full textGlulam is almost exclusively the chosen material of timber frame structures. Of
those, three-hinged (three-pin) portal frames are incomparably the most common
type. Being both statically determinate and stable against horizontal forces
in its own plane o er both practical (basic constructive details) and economical
bene ts.
The design of the haunch allows for various solutions: it can be curved with
continuous laminates, nger jointed, jointed with steel dowels and slotted-in
plates, or built-up with a strut.
The form of the frame derives from the main load's force line. The most appropriate
forms for large spans are curved or built-up haunches, as they ful l
both functional and aesthetic aspects. Three-pin portal frames are suitable for
spans up to 30-40 meters, being the limiting factor the transport feasability of
the frame's halves.
In recent years a handful of three-hinged structures with built-up haunches
have collapsed, leaving behind a need to analyse and study the stresses and
resistance of this structures. For obvious reasons it is specially interesting to
research and clarify the fracture risk on the built-up haunches as well as to map
the stresses created by the inner frame leg through compression to the lower
edge of the frame rafter.
Today there is only one general method used to design built-up haunches,
present in both the Glulam Handbook and the German Institute for Standardization,
DIN, which is based on established practice. Both standards share similar
simpli cations and assumtions, giving surprisingly little importance to the
shear stress that occurs in the contact area of the built-up haunch.
The aim of this master's thesis was to put together a tool, in form of a
diagram, to help design the built-up haunch, with particular emphasis on the
contact area between the inner frame leg and the frame rafter, and the subsequent
shear stresses this contact creates on the rafter. To achieve this result a
sample frame rafter was calculated using 2D frame software and generic loads
and materials. The section forces obtained were then used to create a FEM
model of the built-up haunch.
This FEM model provided a clearer understanding of the behaviour of the frame
leg-frame rafter's contact area as well as yielding a map of the shear stresses
present in the joint. Finally with the use of Linear Elastic Fracture Mechanics
and the mean stress criterion a diagram-tool was created.
This report yielded two results that may be deemed of special interest:
- Both the Glulam Handbook and the german DIN standard relegate the
shear stress in the notch as merely a design checkout, never a design factor.
- Both the Glulam Handbook and the DIN completely disregard the size
e ects in the capacity of birdmouth joints. The fracture mechanics calculations presented in this report provide prove of strong size e ects, so
that current design standards signi cantly overestimate the capacity of
great-sized built-up haunches.
This conclusion could be important in practical terms, and should be
further investigated. Experimental tests should also be inlcuded in future
research.
Keywords: glulam, built-up haunches, framed joint, three-pin portal frames,
shear stress, failure modes, LEFM, ABAQUS, size e ects.Outgoin
Design method for strut-beam connection in hinged frames
No full textGlulam is almost exclusively the chosen material of timber frame structures. Of
those, three-hinged (three-pin) portal frames are incomparably the most common
type. Being both statically determinate and stable against horizontal forces
in its own plane o er both practical (basic constructive details) and economical
bene ts.
The design of the haunch allows for various solutions: it can be curved with
continuous laminates, nger jointed, jointed with steel dowels and slotted-in
plates, or built-up with a strut.
The form of the frame derives from the main load's force line. The most appropriate
forms for large spans are curved or built-up haunches, as they ful l
both functional and aesthetic aspects. Three-pin portal frames are suitable for
spans up to 30-40 meters, being the limiting factor the transport feasability of
the frame's halves.
In recent years a handful of three-hinged structures with built-up haunches
have collapsed, leaving behind a need to analyse and study the stresses and
resistance of this structures. For obvious reasons it is specially interesting to
research and clarify the fracture risk on the built-up haunches as well as to map
the stresses created by the inner frame leg through compression to the lower
edge of the frame rafter.
Today there is only one general method used to design built-up haunches,
present in both the Glulam Handbook and the German Institute for Standardization,
DIN, which is based on established practice. Both standards share similar
simpli cations and assumtions, giving surprisingly little importance to the
shear stress that occurs in the contact area of the built-up haunch.
The aim of this master's thesis was to put together a tool, in form of a
diagram, to help design the built-up haunch, with particular emphasis on the
contact area between the inner frame leg and the frame rafter, and the subsequent
shear stresses this contact creates on the rafter. To achieve this result a
sample frame rafter was calculated using 2D frame software and generic loads
and materials. The section forces obtained were then used to create a FEM
model of the built-up haunch.
This FEM model provided a clearer understanding of the behaviour of the frame
leg-frame rafter's contact area as well as yielding a map of the shear stresses
present in the joint. Finally with the use of Linear Elastic Fracture Mechanics
and the mean stress criterion a diagram-tool was created.
This report yielded two results that may be deemed of special interest:
- Both the Glulam Handbook and the german DIN standard relegate the
shear stress in the notch as merely a design checkout, never a design factor.
- Both the Glulam Handbook and the DIN completely disregard the size
e ects in the capacity of birdmouth joints. The fracture mechanics calculations presented in this report provide prove of strong size e ects, so
that current design standards signi cantly overestimate the capacity of
great-sized built-up haunches.
This conclusion could be important in practical terms, and should be
further investigated. Experimental tests should also be inlcuded in future
research.
Keywords: glulam, built-up haunches, framed joint, three-pin portal frames,
shear stress, failure modes, LEFM, ABAQUS, size e ects.Outgoin
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