книги / Обучение научному диалогу на английском языке
..pdfUNIT 2
TREE SPECIES CAN BE USED IN NEW SUSTAINABLE
BUILDING MATERIAL
Read the text and do the exercises after the text.
Two tree species native to the Northeast have been found to be structurally sound for use in cross-laminated timber (CLT) ‒ a revolutionary new type of building material with sought-after sustainability characteristics, according to research by a University of Massachusetts Amherst timber engineer.
The findings, published in the Journal of Materials in Civil Engineering, suggest that these trees ‒ the eastern hemlock and eastern white pine ‒ could support local markets for CLT. The manufacturing of CLT, a type of mass timber used for wall, floor and roof construction, could create jobs, improve rural and forestry economies and support better forestry management, which is a strategy to address climate change, the research says.
"This is the future ‒ prefabricated, panelized wood," says lead author Peggi Clouston, professor of wood mechanics and timber engineering in the School of Earth and Sustainability. "It's far more efficient and there's far less waste than site construction. It's less timeand labor-intensive than building with cast-in-place concrete" and has a much lower carbon footprint.
Clouston's leadership in state-of-the-art wood construction technology was instrumental in the creation of UMass Amherst's John W. Olver Design Building, a showcase for best practices in sustainability. When the structure opened in 2017 to house academic departments and offices, it was considered the most technologically advanced CLT building in the country. All the CLT for the Design Building was FSC-certified, ensuring it came from responsibly managed forests that deliver environmental, social and economic benefits.
"We wanted to show the world how to build a contemporary mass timber structure, and we are doing so. Groups have come from as far away as Taiwan to see it," Clouston says.
Clouston and her team of researchers tested the eastern hemlock and eastern white pine in the UMass Wood Mechanics Lab at the Olver Design Building. They made the composite building panels by gluing together wooden boards from hemlock and pine trees that were grown in the region.
"We then broke them in a strength-testing machine to find out if they would be safe to use in a university-size building," Clouston explains.
The researchers analyzed the results, comparing them to engineering requirements, and showed that both tree species met building standards, with eastern hemlock outperforming pine.
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Salvaging wood from eastern hemlock is a key forest-management priority, Clouston explains, because the trees are under attack by an insect, the hemlock wooly adelgid. "The insect doesn't harm the wood, but it kills the tree, which in five to 10yearswillrotandfalldown,becominghazardousfuelforforestfires,"shesays.
Eastern hemlock also is considered low-value because it's prone to a wood defect called ring shake and isn't used in structural framing. "Turning this particular species into CLT turns a very low-value material into a very high-value building product," Clouston says.
Identifying low-carbon materials for construction is an emerging buzz among architects, and the timing is right to encourage CLT production in the Northeast, the research concludes.
Exercise 1. Use the following words in different types of questions:
tree species, structurally sound, cross-laminated timber (CLT), sought-after sustainability characteristics, timber engineer, the manufacturing of CLT, to create jobs, to improve rural and forestry economies, to support better forestry management, prefabricated, panelized wood, wood mechanics and timber engineering, efficient, technologically advanced, to deliver environmental, social and economic benefits, composite building panels, a strength-testing machine, a key forestmanagement priority, to be under attack by hazardous fuel, a very low-value material, a very high-value building product, to encourage CLT production.
For example,
What is cross-laminated timber (CLT)?
What improves rural and forestry economies?
Exercise 2.Makeupdifferent typesofquestionsusingthefollowing clichés:
For example,
Would you explain what …?
Do you know that…?
Exercise 3. Agree with your partner using the words given in brackets.
For example, It is said that the manufacturing of CLT is efficient … (create jobs, improve rural and forestry economies, support better forestry management).
Exercise 4. Ask your partner questions to get the information on the point. Use speech patterns in your questions (see Appendix 1. Speech Patterns and Clichés for Discussion).
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Exercise 5. Answer the questions of your partner expressing disagreement.
Use the negative constructions and the words given in brackets:
I don’t agree with you … (sought-after sustainability characteristics), I disagree with you … (deliver environmental, social and economic benefits), I think you are wrong … (a key forest-management priority), I consider you are mistaken … (a very low-value material) etc.
Exercise 6. Agree with your partner’s opinion; prove your point of view giving the arguments from the text.
For example,
Student 1: I’ve read that a professor of wood mechanics and timber engineering found a revolutionary new type of building material with sought-after sustainability characteristics.
Student 2: I believe so. The eastern hemlock and eastern white pine could support local markets for CLT. The manufacturing of CLT, a type of mass timber used for wall, floor and roof construction, could create jobs, improve rural and forestry economies and support better forestry management.
Exercise 7. Disagree with the counterarguments of your partner.
For example,
Student 1: The researchers analyzed the results, comparing them to engineering requirements, and showed that both tree species didn’t meet building standards.
Student 2: Sorry, you are wrong. The scientists proved that both tree species met standards of building materials.
Exercise 8. Disagree with the statements of your partner, giving your vision of the problem using the provements from the text.
Exercise 9. Discuss the problems using the word combinations and give the arguments and examples from the text:
create jobs
technologically advanced
deliver benefits
a strength-testing machine
be under attack by
to encourage CLT production etc.
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Exercise 10. Listen to your partner and give the assessment to the information using such phrases as: As I am concerned..., It is difficult to say…, I would like to propose that...
Act out the dialogue following the sample:
A:I have read the article about two tree species that have been found to be structurally sound for use in cross-laminated timber. Moreover, it is stated that a revolutionary new type of building material has sought-after sustainability characteristics.
B:I would like to propose that these trees ‒ the eastern hemlock and eastern white pine ‒ could support local markets for CLT.
A:You are quite right. As I am concerned it could create jobs, improve rural and forestry economies and support better forestry management.
B:Yes, also it is a strategy to address climate change, the research says.
Exercise 11. Discuss the given tips on the bases of the brief information on the problem given in the text:
prefabricated, panelized wood
wood mechanics and timber engineering
composite building panels
sustainability
structurally sound material
Use the speech patterns (see Appendix 1. Speech Patterns and Clichés for Discussion).
Exercise 12. Formulate the thesis on the problem about using lowcarbon materials for construction, act out the fragment of a discussion following the plan given below. Use speech patterns and clichés for discussion.
А – formulation of the thesis and arguments from the text to prove it (items 1–3 from the list of speech patterns and clichés for discussion).
В – expressing the agreement with the partner’s thesis (items 1–6). С – summarizing the information, conclusion (item 2).
Exercise 13. Study the information on the problem, collect the necessary facts to be ready to take part in the discussion following the plan given below:
А – formulating of the thesis and giving the quotation from the text to prove it (items 1–3 from the list of speech patterns and clichés for discussion).
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В – expressing the partly agreement with the partner’s thesis and its explanation (items 7–10).
С – stating a self-critical position and expressing approval (agreement) (items 4–6).
Exercise 14. Search for the information necessary for your taking part in the part of the discussion “Trees Can Be Used in New Sustainable Building Material”. Follow the roles (A, B, С, D) and the plan given bellow.
А – formulating of the thesis and conclusion (items 1–2 from the list of speech patterns and clichés for discussion).
В – expressing doubt in accuracy of the statement, giving your reasons (items 8, 3, 2).
С – stating a self-critical position (items 4)
D – formulating of an antithesis, giving your reasons (items 1, 3, 2)
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UNIT 3
HIGH STRENGTH STEEL AT UNPRECEDENTED LEVELS
OF FRACTURE RESISTANCE
Read the text and do the exercises after the text.
The Super Steel project led by Professor Huang Mingxin at the Department of Mechanical Engineering of the University of Hong Kong (HKU), with collaborators at the Lawrence Berkeley National Lab (LBNL), has made important breakthrough in its new super D&P steel (produced using a new deformed and partitioned method) to greatly enhance its fracture resistance while maintaining super strong in strength for advanced industrial applications.
The findings were published in Science on 8 May 2020 in the paper titled "Making Ultrastrong Steel Tough by Grain-Boundary Delamination."
Steel is a common alloy. Material scientists and engineers are continually seeking to develop new generation steel materials which are easier to extend and elongate (ductility) into different forms and structures, higher in resistance to deformation (strength) and fracture (toughness), light in weight and low in production cost.
The task has been difficult. The conventional view is that raising the performance of one metallic property, whether in strength, ductility or toughness, will undermine one or more of the others. For example, an increase in strength will inevitably make the metal more brittle (known as the strength-toughness trade-off); or less flexible to be extended or elongated into different shapes (strength-ductility trade-off).
"In this latest breakthrough in super D&P steel, we attained an unprecedented strength-toughness combination which can address a major challenge in safety-critical industrial applications ‒ to attain an ultra-high fracture toughness so as to prevent catastrophic premature fracture of structural materials. The breakthrough also changes the conventional view that attaining high strength will be at the expense of deteriorating toughness, which invariably leads to the embrittlement of structural materials and greatly limits their application," said Professor Huang.
The team had earlier raised significantly the D&P steel's strength-ductility performance, the super D&P steel hence attains excellent performance in all three metallic properties at an unprecedented high level not reached by any steel materials before.
Several patents in US, EU and China have been filed. The team has been liaising with industrial partners to generate prototypes of high-strength bridge cable, bullet proof vest and car spring with the super steel for further tests and trials to be conducted. The latest breakthrough in the D&P steel, made in collaboration with Professor Robert O. Ritchie's research team at the Lawrence Berkeley National Lab (LBNL) and UC Berkeley, results in the steel a yield strength resistance against deformation of ~2GPa, a superior fracture toughness of 102MPažm½, and a good uniform elongation of 19 %.
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The team has also made an important scientific discovery in the structure of the super D&P steel. The super steel has a unique fracture feature in which multiple micro-cracks are formed below the main fracture surface, through a novel "high-strength induced multi-delamination" toughening mechanism. These microcracks can effectively absorb energy from externally applied forces, resulting in the steel's much higher toughness resistance compared to existing steel materials.
Currently, high strength steel for bridge cables has a yield strength lower than 1.7 GPa ~, and a fracture toughness lower than 65 MPažm½; high strength armoured steel used in armoured cars has a similar maximum strength – toughness combination. The toughness level that can be attained by the D&P steel is hence much higher than that of existing steel materials, while maintaining super strong in strength.
Steel piano wire, for instance, has an ultra-high strength ranging from 2.6 to 2.9 GPa to resist deformation and to keep the instrument in tune, which is achieved at the expense of toughness and is in turn very brittle.
Meanwhile, the cost of raw materials of the D&P steel is only 20 % of the maraging steel currently used in aerospace (e.g. Grade 300, whose yield strength and fracture initiation toughness are 1.8 GPa and 70 MPaž m½, respectively).
"D&P steel has other advantages such as simple industrial processing and low raw-materials cost. It can be produced by conventional rolling and annealing processes, as such no complex fabrication routes and special equipment are required," said Miss Li LIU, the first author of the journal article and a PhD student supervised by Professor Huang.
"We have made a big step closer to industrializing the novel super steel. It demonstrates a great potential to be used in various applications including superior bulletproof vests, bridge cables, lightweight automobile and military vehicles, aerospace, and high strength bolts and nuts in the construction industry." Professor Huang added.
Exercise 1. Use the following words in different types of questions:
important breakthrough, D&P steel, enhance, fracture resistance, industrial applications, ultra-strong steel tough, seeking to develop, easier to extend, elongate, resistance to deformation, fracture, light in weight, low in production cost, the conventional view, metallic property, inevitably, brittle, strength-ductility trade-off, unprecedented strength-toughness combination, to attain an ultra-high fracture toughness, to prevent catastrophic premature fracture of structural materials, deteriorating toughness, embrittlement of structural materials, greatly limits, raised significantly, strength-ductility performance, an unprecedented high-level, to generate prototypes, high-strength bridge cable, strength resistance against deformation, multiple micro-cracks, "high-strength induced multi-delamination" toughening mechanism, absorb energy, is achieved at the expense of.
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For example,
What is D&P steel?
What enhances its fracture resistance?
Exercise 2.Makeupdifferent typesofquestionsusingthefollowing clichés:
For example,
Would you explain what …?
Do you know that…?
Exercise 3. Agree with your partner using the words given in brackets.
For example,
The findings published in Science on 8 May 2020 in the paper titled "Making Ultrastrong Steel Tough by Grain-Boundary Delamination." said that the new generation steel materials … (easier to extend and elongate, higher in resistance to deformation (strength) and fracture (toughness), light in weight and low in production cost).
Exercise 4. Ask your partner questions to get the information on the point. Use speech patterns in your questions (see Appendix 1. Speech Patterns and Clichés for Discussion).
Exercise 5. Answer the questions of your partner expressing disagree-
ment.
Use the negative constructions and the words given in brackets:
I don’t agree with you … (unprecedented strength-toughness combination), I disagree with you … (to attain an ultra-high fracture toughness), I consider you are mistaken … (to prevent catastrophic premature fracture of structural materials) etc.
Exercise 6. Agree with your partner’s opinion; prove your point of view giving the arguments from the text.
For example,
Student 1: I have read that material scientists and engineers are continually seeking to develop new generation steel materials which are easier to extend and elongate into different forms and structures, higher in resistance to deformation and fracture, light in weight and low in production cost.
Student 2: Well, I agree with you. The task to develop new generation steel materials is very difficult as there is the conventional view that raising the performance of one metallic property, whether in strength, ductility or toughness, will undermine one or more of the others.
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Exercise 7. Disagree with the counterarguments of your partner.
For example,
Student 1: Unfortunately, the super steel has a number of drawbacks, for example, it forms multiple micro-cracks below the main fracture surface.
Student 2: Sorry, you are mistaken. These micro-cracks can effectively absorb energy from externally applied forces, resulting in the steel's much higher toughness resistance compared to existing steel materials.
Exercise 8. Disagree with the statements of your partner, giving your vision of the problem using the provements from the text.
Exercise 9. Discuss the problems using the word combinations and give the arguments and examples from the text:
important breakthrough
to enhance fracture resistance
metallic property
resistance to deformation
low in production cost
Exercise 10. Act out the dialogue following the sample:
A:I have learned that high strength steel for bridge cables has a yield strength lower than 1.7 GPa, and a fracture toughness lower than 65 MPažm½. Besides high strength armoured steel used in armoured cars has a similar maximum strength-toughness combination.
B:As I am concerned, the toughness level that can be attained by the D&P steel is hence much higher than that of existing steel materials, while maintaining super strong in strength.
A:Good news! It demonstrates a great potential to be used in various appli-
cations.
B:Yes, also it can be used in production of superior bulletproof vests, bridge cables, lightweight automobile and military vehicles, aerospace, and high strength bolts and nuts in the construction industry.
Listen to your partner and give the assessment to the information using such phrases as: As I am concerned..., It is difficult to say, I would like to propose that...
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Exercise 11. Discuss the given tips on the bases of the brief information on the problem given in the text:
unprecedented strength-toughness combination
deteriorating toughness
embrittlement of structural materials
high-strength bridge cable
strength resistance against deformation
multiple micro-cracks
Use the following speech patterns (see Appendix 1. Speech Patterns and Clichés for Discussion).
Exercise 12. Formulate the thesis on the problem about a great potential of the novel super steel, act out the fragment of a discussion following the plan given below. Use speech patterns and clichés for discussion.
А – formulation of the thesis and arguments from the text to prove it (items 1–3 from the list of speech patterns and clichés for discussion).
В – expressing the agreement with the partner’s thesis (items 1–6). С – summarizing the information, conclusion (item 2).
Exercise 13. Study the information on the problem, collect the necessary facts to be ready to take part in the discussion following the plan given below:
А – formulating of the thesis and giving the quotation from the text to prove it (items 1–3 from the list of speech patterns and clichés for discussion).
В – expressing the partly agreement with the partner’s thesis and its explanation (items 7–10).
С – stating a self-critical position and expressing approval (agreement) (items 4–6).
Exercise 14. Search for the information necessary for your taking part in the part of the discussion “New Generation Steel Materials”. Follow the roles (A, B, С, D) and the plan given bellow.
А – formulating of the thesis and conclusion (items 1–2 from the list of speech patterns and clichés for discussion).
В – expressing doubt in accuracy of the statement, giving your reasons (items 8, 3, 2).
С – stating a self-critical position (items 4)
D – formulating of an antithesis, giving your reasons (items 1, 3, 2).
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