scholarly journals Structural Design Elements in Biological Materials: Application to Bioinspiration

2015 ◽  
Vol 27 (37) ◽  
pp. 5455-5476 ◽  
Author(s):  
Steven E. Naleway ◽  
Michael M. Porter ◽  
Joanna McKittrick ◽  
Marc A. Meyers
Keyword(s):  
Structural Design ◽  
Biological Materials ◽  
Design Elements

An Innovative Self Installing Platform (SIP) Concept

2011 ◽  
Author(s):  
Frank Slangen ◽  
Wim Bal ◽  
Mark Riemers
Keyword(s):  
North Sea ◽  
Water Depth ◽  
Structural Design ◽  
Pile Foundation ◽  
Design Stage ◽  
Process Equipment ◽  
Design Elements ◽  
The North ◽  
The North Sea ◽  
Outside Diameter

Centrica Energy (formerly Venture) selected a self installing and re-usable platform concept (SIP) to develop their F3FA gas field in the Northern Part of the Dutch sector of the North Sea. On 6 February 2009 and following an initial FEED study, the contract was awarded to Heerema Fabrication Group (Main Contractor and Fabricator), in partnership with Iv-Oil & Gas (Designer and Procurer of process equipment) and SPT Offshore (Installation Contractor and Foundation Designer). The platform weighed in total 8,800 ton, including a 4,000 ton deck and 4,800 ton substructure including the suction pile foundation. The water depth at the F3FA site is 41m and the bottom of the cellar deck is located at 20m above LAT. The platform has an overall dimension of 63m × 45m footprint and protrudes some 90m above the seabed (excluding vent stack). The platform concept consists basically of a deck of 5 levels supported by 4 unbraced legs (3.25m outside diameter × 77m long) and founded on 4 huge suction piles (15m outside diameter × 13m deep). The platform is transported and installed using a large flat top barge (BOA 35 measuring 124m long × 31.5m wide × 8m high) and 3 tug boats (75, 90 and 183 ton bollard pull) for the tow from HFG’s yard in Vlissingen to the F3FA site in the Dutch sector of the North Sea. The leg lowering and deck lifting was achieved using 12× 900 ton strand jacks. The suction pile foundation was installed using 4× suction pumps. During the detailed design stage of the project, the concept design was subject to several elementary changes in the structural design. This had to do with the severe environment, the increased deck weight and water depth compared to the earlier utilisation of the concept. Fatigue and transport and installation issues had a significant impact on several key structural design elements. This complicated the deck-leg connections and several members in the truss deck. The deck leg connection was amended from a simple clamp connection in to a superbolt and sleeve connection at the top deck and a clamped and grouted connection at the cellar deck. In order to improve the stiffness of the legs, leg stiffening frames were placed on top of the suction piles. Due to the limited and slow roll & pitch response of the platform whilst on the BOA barge during tow, high seafastening forces were predicted. These high seafastening forces were transferred in to the barge using pinned seafastening arms. Water depth limitations and the additional leg stiffening frames necessitated to use a fairly high grillage structure of 6.5m high. All these items changed the deck construction towards a method obstructing completion of non-structural disciplines and changed the inshore mating operation of the substructure with that topside towards a complex lifting and fitting campaign. Despite these elementary design changes and some rigorous changes in the planning of the various activities, the contract schedule was achieved in time. The above efforts had an obvious effect on the managerial issues towards the project. It required a doubling of the manning levels and engineering issues of in some cases R&D nature. Despite all these challenges and complications, the platform left Vlissingen well ahead of time, on 18 August 2010, to set sail for the F3FA site. Upon arrival in the field, the weather deteriorated severely and the tow was forced to seek shelter in Rotterdam. Just before arrival in Rotterdam severe waves were encountered up to 6–7m maximum. Upon inspection in Rotterdam, the design proved to be resilient as no signs of damage were observed. Following 10 days waiting on weather the platform was towed to the field for the second time. Installation and lifting the deck to the top elevation was achieved within a record time of 2 days and 4 hours. Thereafter the platform hook-up team continued to work on the platform including completing the deck leg connections, such as installation of superbolts at the top deck level and clamp shells, rubber pads and grout at the cellar deck level. Further hook-up work consisted of hooking up the life support systems before arrival of the drill rig on 14th October 2010. The drilling of the first well was completed early January 2011 and first gas was introduced in to the pipeline system since week 4 of 2011.

Bioinspired Materials Design: An Assessment of Methods to Improve a Text Mining Algorithm for Identifying Biological Material Structural Design Principles

2016 ◽  
Author(s):  
Joanna Tsenn ◽  
Julie S. Linsey ◽  
Daniel A. McAdams
Keyword(s):  
Text Mining ◽  
Structural Design ◽  
Design Principles ◽  
Biological Materials ◽  
Journal Articles ◽  
Part Of Speech ◽  
Mining Algorithm ◽  
Wide Range ◽  
Bioinspired Materials ◽  
Future Work

Natural materials are able to achieve a wide range and combination of properties through the arrangement of the material’s components. These biological materials are often more effective and better suited to their function than engineered materials, even with the use of a limited set of components. By mimicking a biological material’s component arrangement, or structure, man-made bioinspired materials can achieve improved properties as well. While considerable research has been conducted on biological materials, identifying the beneficial structural design principles can be time-intensive for a materials designer. Previously, a text mining algorithm and tool were developed to quickly extract passages describing property-specific structural design principles from a corpus of materials journals. Although the tool identified over 90% of the principles (recall), many irrelevant passages were returned as well with approximately 32% of the passages being useful (precision). This paper discusses approaches to refine the program in order to improve precision. The text classification techniques of machine learning classifiers, statistical features, and part-of-speech analyses, are evaluated for effectiveness in sorting passages into relevant and irrelevant classes. Manual identification of patterns in the returned passages is also employed to create a rule-based method, resulting in an updated algorithm. An evaluation comparing the revised algorithm to the previously developed algorithm is completed using a new set of journal articles. Although the revised algorithm’s recall was reduced to 80%, the precision increased to 45% and the number of returned passages was reduced by 22%, allowing a materials designer to more quickly identify potentially useful structures. The paper concludes with suggestions to improve the program’s usefulness and scope for future work.

Surface microscopy study of metallic and ceramic orthodontic brackets

2015 ◽  
Vol 61 (1) ◽  
pp. 20-24
Author(s):  
Ionuţ-Cornel Ionescu ◽  
◽  
Ecaterina Ionescu ◽  
Keyword(s):  
Electron Microscopy ◽  
Structural Design ◽  
Microscopy Study ◽  
The Other ◽  
Surface Microstructure ◽  
Design Elements ◽  
Ceramic Brackets ◽  
Surface Microscopy ◽  
Orthodontic Forces ◽  
Scanning Electron

An in-depth knowledge of the characteristics of the appliances with which we work is very important because it helps us to better understand the indications, contraindications, strengths and their possible shortcomings. The structural design elements play an important role in this context. One of the most commonly used methods for investigating them is represented by scanning electron microscopy. Using a scanning electron microscope we studied the aspects of the surface microstructure of metal and ceramic brackets. The results show that each of them has design features that help with the delivery of orthodontic forces. These characteristics differ drastically in shape from one type of bracket to the other, a square or diamond-shaped network in the case of metal brackets and an appearance of granules dispersed on the surface of the ceramic brackets.

Development of a Search Tool to Identify Structural Design Principles for Bioinspired Materials Design

2014 ◽  
Author(s):  
Joanna Tsenn ◽  
Julie S. Linsey ◽  
Daniel A. McAdams
Keyword(s):  
Material Properties ◽  
Structural Design ◽  
Design Principles ◽  
Biological Materials ◽  
Search Term ◽  
Manual Search ◽  
Bioinspired Materials ◽  
Search Tool ◽  
Engineered Materials ◽  
Key Terms

Natural materials are often more efficient and tend to have a wider range and combination of properties than do present-day engineered materials. Biological materials are composed from a limited set of components, but are able to achieve great diversity in their properties. The variation in properties is largely due to the different arrangements of the materials components, which form unique structures. We believe that there are underlying structural design principles, relating material structure to material properties, that commonly appear in biological materials. Because nature itself achieves highly effective design solutions, the utilization of these natural design principles could similarly improve the effectiveness of engineered materials. Materials scientists need a way to abstract relevant structural design principles from the myriad of biological materials articles for the development of bioinspired materials. This research involves the development of a data mining tool that will quickly identify potential structural design principles of biological materials with respect to a chosen material property or combination of properties. This paper presents the first stage of this process: information retrieval. An algorithm is developed to extract structural design principles’ key terms and relevant passages for specified material properties from a corpus of materials journal articles. The development of this search tool is explained beginning with the determination of search term categories and appropriate search terms and continuing to the refinement of the program algorithm. An evaluation of the tool is also described comparing the program’s results to those of a manual search for the structure-property relationships. The program identified 98% of the manually found structural design principle key terms, although many unanticipated passages were returned as well. Finally, the future work needed to improve the program is presented.

New Design for a Differentially Pumped Hydration Chamber for a Siemens IA

1971 ◽  
Vol 29 ◽  
pp. 44-45
Author(s):  
R. C. Moretz ◽  
G. G. Hausner ◽  
D. F. Parsons
Keyword(s):  
Electron Microscopy ◽  
Water Vapor ◽  
Electron Diffraction ◽  
Water Vapor Pressure ◽  
Biological Materials ◽  
Thin Membrane ◽  
Reliable System ◽  
System A ◽  
Water Films ◽  
Aperture Opening

Electron microscopy and diffraction of biological materials in the hydrated state requires the construction of a chamber in which the water vapor pressure can be maintained at saturation for a given specimen temperature, while minimally affecting the normal vacuum of the remainder of the microscope column. Initial studies with chambers closed by thin membrane windows showed that at the film thicknesses required for electron diffraction at 100 KV the window failure rate was too high to give a reliable system. A single stage, differentially pumped specimen hydration chamber was constructed, consisting of two apertures (70-100μ), which eliminated the necessity of thin membrane windows. This system was used to obtain electron diffraction and electron microscopy of water droplets and thin water films. However, a period of dehydration occurred during initial pumping of the microscope column. Although rehydration occurred within five minutes, biological materials were irreversibly damaged. Another limitation of this system was that the specimen grid was clamped between the apertures, thus limiting the yield of view to the aperture opening.

Evaluation of Freezing Methods by Low Temperature X-Ray Diffraction

1977 ◽  
Vol 35 ◽  
pp. 330-333
Author(s):  
T. Gulik-Krzywicki ◽  
M.J. Costello
Keyword(s):  
Biological Materials ◽  
Molecular Organization ◽  
X Ray Diffraction ◽  
Glass Capillary ◽  
X Ray ◽  
Rate Dependent ◽  
Before And After ◽  
Freeze Etching ◽  
Diffraction Patterns ◽  
Set Up

Freeze-etching electron microscopy is currently one of the best methods for studying molecular organization of biological materials. Its application, however, is still limited by our imprecise knowledge about the perturbations of the original organization which may occur during quenching and fracturing of the samples and during the replication of fractured surfaces. Although it is well known that the preservation of the molecular organization of biological materials is critically dependent on the rate of freezing of the samples, little information is presently available concerning the nature and the extent of freezing-rate dependent perturbations of the original organizations. In order to obtain this information, we have developed a method based on the comparison of x-ray diffraction patterns of samples before and after freezing, prior to fracturing and replication.Our experimental set-up is shown in Fig. 1. The sample to be quenched is placed on its holder which is then mounted on a small metal holder (O) fixed on a glass capillary (p), whose position is controlled by a micromanipulator.

Enhanced information from biological materials through technological improvements in cryo-electron microscopy

1992 ◽  
Vol 50 (1) ◽  
pp. 788-789
Author(s):  
Marc J.C. de Jong ◽  
Wim M. Busing ◽  
Max T. Otten
Keyword(s):  
Electron Microscopy ◽  
Electron Beam ◽  
Biological Materials ◽  
Electron Crystallography ◽  
Cryo Electron Microscopy ◽  
Transmission Electron ◽  
The Many ◽  
Technological Improvements ◽  
Beam Damage

Biological materials damage rapidly in the electron beam, limiting the amount of information that can be obtained in the transmission electron microscope. The discovery that observation at cryo temperatures strongly reduces beam damage (in addition to making it unnecessaiy to use chemical fixatives, dehydration agents and stains, which introduce artefacts) has given an important step forward to preserving the ‘live’ situation and makes it possible to study the relation between function, chemical composition and morphology.Among the many cryo-applications, the most challenging is perhaps the determination of the atomic structure. Henderson and co-workers were able to determine the structure of the purple membrane by electron crystallography, providing an understanding of the membrane's working as a proton pump. As far as understood at present, the main stumbling block in achieving high resolution appears to be a random movement of atoms or molecules in the specimen within a fraction of a second after exposure to the electron beam, which destroys the highest-resolution detail sought.

Application of ruthenium red/osmium tetroxide to bacteria, plant and animal tissue

1986 ◽  
Vol 44 ◽  
pp. 54-55
Author(s):  
R. L. Grayson ◽  
N. A. Rechcigl
Keyword(s):  
Electron Microscopy ◽  
Electron Density ◽  
Osmium Tetroxide ◽  
Biological Materials ◽  
Ruthenium Red ◽  
Animal Tissue

Ruthenium red (RR), an inorganic dye was found to be useful in electron microscopy where it can combine with osmium tetroxide (OsO4) to form a complex with attraction toward anionic substances. Although Martinez-Palomo et al. (1969) were one of the first investigators to use RR together with OsO4, our computor search has shown few applications of this combination in the intervening years. The purpose of this paper is to report the results of our investigations utilizing the RR/OsO4 combination to add electron density to various biological materials. The possible mechanisms by which this may come about has been well reviewed by previous investigators (1,3a,3b,4).

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