30 research outputs found
A Review of Layer Based Manufacturing Processes for Metals
The metal layered manufacturing processes have provided industries with a fast method
to build functional parts directly from CAD models. This paper compares current metal layered
manufacturing technologies from including powder based metal deposition, selective laser
sinstering (SLS), wire feed deposition etc. The characteristics of each process, including its
industrial applications, advantages/disadvantages, costs etc are discussed. In addition, the
comparison between each process in terms of build rate, suitable metal etc. is presented in this
paper.Mechanical Engineerin
Automated Retrieval of Non-Engineering Domain Solutions to Engineering Problems
Organised by: Cranfield UniversityBiological inspiration for engineering design has occurred through a variety of techniques such as creation
and use of databases, keyword searches of biological information in natural-language format, prior
knowledge of biology, and chance observations of nature. This research focuses on utilizing the reconciled
Functional Basis function and flow terms to identify suitable biological inspiration for function based design.
The organized search provides two levels of results: (1) associated with verb function only and (2) narrowed
results associated with verb-noun (function-flow). A set of heuristics has been complied to promote efficient
searching using this technique. An example for creating smart flooring is also presented and discussed.Mori Seiki – The Machine Tool Compan
Comparison of Thermal Properties of Laser Deposition and Traditional Welding Process Via Thermal Diffusivity Measurement
Laser deposition is an effective process for mold and die repair. In order to improve the part repair quality, the process impact on thermal diffusivity and thermal conductivity needs to be understood for laser deposited, welded and virgin H13. In this paper, H13 tool steel samples were made by laser deposition, welding and virgin H13 and then cut into pieces. Experiments were conducted to investigate the thermal diffusivity and conductivity. A laser flash method is used to test these samples. The future work and opportunities are also summarized
Development of High Intensity Neutron Source at the European Spallation Source
The European Spallation Source being constructed in Lund, Sweden will provide
the user community with a neutron source of unprecedented brightness. By 2025,
a suite of 15 instruments will be served by a high-brightness moderator system
placed above the spallation target. The ESS infrastructure, consisting of the
proton linac, the target station, and the instrument halls, allows for
implementation of a second source below the spallation target. We propose to
develop a second neutron source with a high-intensity moderator able to (1)
deliver a larger total cold neutron flux, (2) provide high intensities at
longer wavelengths in the spectral regions of Cold (4-10 \AA ), Very Cold
(10-40 \AA ), and Ultra Cold (several 100 \AA ) neutrons, as opposed to Thermal
and Cold neutrons delivered by the top moderator. Offering both unprecedented
brilliance, flux, and spectral range in a single facility, this upgrade will
make ESS the most versatile neutron source in the world and will further
strengthen the leadership of Europe in neutron science. The new source will
boost several areas of condensed matter research such as imaging and spin-echo,
and will provide outstanding opportunities in fundamental physics
investigations of the laws of nature at a precision unattainable anywhere else.
At the heart of the proposed system is a volumetric liquid deuterium moderator.
Based on proven technology, its performance will be optimized in a detailed
engineering study. This moderator will be complemented by secondary sources to
provide intense beams of Very- and Ultra-Cold Neutrons.Comment: 12 pages, 4 figures, proceeding of the 23rd meeting of the
International Collaboration on Advanced Neutron Sources (ICANS XXIII) 13th -
18th October 2019 in Chattanooga, Tennesse
McMurdo Dry Valleys, Antarctica - A Mars Phoenix Mission Analog
The Phoenix mission (PHX; May 25 - Nov. 2, 2008) studied the north polar region of Mars (68deg N) to understand the history of water and potential for habitability. Phoenix carried with it a wet chemistry lab (WCL) capable of determining the basic solution chemistry of the soil and the pH value, a thermal and evolved-gas analyzer capable of determining the mineralogy of the soil and detecting ice, microscopes capable of seeing soil particle shapes, sizes and colors at very high resolution, and a soil probe (TECP) capable of detecting unfrozen water in the soil. PHX coincided with an international effort to study the Earth s polar regions named the International Polar Year (IPY; 2007-2008). The best known Earth analog to the Martian high-northern plains, where Phoenix landed, are the McMurdo Dry Valleys (MDV), Antarctica (Fig. 1). Thus, the IPY afforded a unique opportunity to study the MDV with the same foci - history of water and habitability - as PHX. In austral summer 2007, our team took engineering models of WCL and TECP into the MDV and performed analgous measurements. We also collected sterile samples and analyzed them in our home laboratories using state-of-the-art tools. While PHX was not designed to perform biologic analyses, we were able to do so with the MDV analog samples collected
Finite Volume Kolmogorov-Johnson-Mehl-Avrami Theory
We study Kolmogorov-Johnson-Mehl-Avrami (KJMA) theory of phase conversion in
finite volumes. For the conversion time we find the relationship . Here is the space dimension, the nucleation time in the volume , and a scaling function.
Its dimensionless argument is , where
is an expansion time, defined to be proportional to the
diameter of the volume divided by expansion speed. We calculate in
one, two and three dimensions. The often considered limits of phase conversion
via either nucleation or spinodal decomposition are found to be volume-size
dependent concepts, governed by simple power laws for .Comment: 4 pages, 4 figures. Additions after referee reports: Scaling of the
variable q is proven. Additional references are adde
Effects of parental imprisonment on child antisocial behaviour and mental health: a systematic review
Parental imprisonment can cause many problems for the family left behind,
including difficulty organising childcare, loss of family income, trouble maintaining
contact with the imprisoned parent, stigma, and home, school and neighbourhood
moves. Children and parents can be distressed by the separation. Children may
respond by acting out or becoming withdrawn, anxious or depressed. We conducted
an exhaustive search for studies that examined children's antisocial behaviour and
mental health after parental imprisonment. We found 16 studies with appropriate
evidence. These studies all showed that children of prisoners are more likely than
other children to show antisocial and mental health problems. However, it was
unclear whether parental imprisonment actually caused these problems. They might
have been caused by other disadvantages in children's lives that existed before
parental imprisonment occurred. Children of prisoners are a vulnerable group. More
research is required to determine whether or not parental imprisonment causes an
increase in child antisocial behaviour and mental health problems
An Engineering-to-Biology Thesaurus To Promote Better Collaboration, Creativity and Discovery
Organised by: Cranfield UniversityBiological inspiration for engineering design has occurred through a variety of techniques such as database
searches, keyword and antonym searches, knowledge of biology, observations of nature and other “aha”
moments. This research aims to alleviate the knowledge gap problem by providing a link between
engineering and biology with a thesaurus. The biologically connotative terms that comprise the thesaurus
were collected utilizing an organized verb-noun search; collocated words were extracted from texts based
on a functional search word. This thesaurus should enable the engineering and biology communities to
better collaborate, create and discover.Mori Seiki – The Machine Tool Compan
Numerical and Analytical Modeling of Laser Deposition with Preheating
Laser deposition allows quick fabrication of fully-dense metallic components directly from CAD solid models. This work uses both numerical and analytical approaches to model the laser deposition process including actual deposition and preheating. The numerical approach is used to simulate the coupled, interactive transport phenomena during actual deposition. The numerical simulation involves laser material interaction, free surface evolution, and melt-pool dynamics. The analytical approach is used to model heat transfer during preheating. The combination of these two approaches can increase computational efficiency with most of the phenomena associated with laser deposition modeled. The simulation is applied to Ti-6Al-4V and simulation results are compared with experimental results