id stringlengths 24 24 | title stringclasses 442
values | context stringlengths 151 3.71k | question stringlengths 12 270 | answers dict |
|---|---|---|---|---|
57293c473f37b31900478154 | Glass | Glass remained a luxury material, and the disasters that overtook Late Bronze Age civilizations seem to have brought glass-making to a halt. Indigenous development of glass technology in South Asia may have begun in 1730 BCE. In ancient China, though, glassmaking seems to have a late start, compared to ceramics and met... | What city was a center of glass production for the Romans? | {
"answer_start": [
422
],
"text": [
"Trier"
]
} |
57293c473f37b31900478155 | Glass | Glass remained a luxury material, and the disasters that overtook Late Bronze Age civilizations seem to have brought glass-making to a halt. Indigenous development of glass technology in South Asia may have begun in 1730 BCE. In ancient China, though, glassmaking seems to have a late start, compared to ceramics and met... | In what current country is Trier located? | {
"answer_start": [
443
],
"text": [
"Germany"
]
} |
5729450a6aef051400154c2e | Glass | Glass was used extensively during the Middle Ages. Anglo-Saxon glass has been found across England during archaeological excavations of both settlement and cemetery sites. Glass in the Anglo-Saxon period was used in the manufacture of a range of objects including vessels, beads, windows and was also used in jewelry. Fr... | When did stained glass make a big comeback? | {
"answer_start": [
742
],
"text": [
"19th-century"
]
} |
5729450a6aef051400154c2f | Glass | Glass was used extensively during the Middle Ages. Anglo-Saxon glass has been found across England during archaeological excavations of both settlement and cemetery sites. Glass in the Anglo-Saxon period was used in the manufacture of a range of objects including vessels, beads, windows and was also used in jewelry. Fr... | When did stained glass begin to be used for places of worship? | {
"answer_start": [
327
],
"text": [
"10th-century"
]
} |
5729450a6aef051400154c30 | Glass | Glass was used extensively during the Middle Ages. Anglo-Saxon glass has been found across England during archaeological excavations of both settlement and cemetery sites. Glass in the Anglo-Saxon period was used in the manufacture of a range of objects including vessels, beads, windows and was also used in jewelry. Fr... | When did big windows of stained glass become less common? | {
"answer_start": [
761
],
"text": [
"the Renaissance"
]
} |
5729450a6aef051400154c31 | Glass | Glass was used extensively during the Middle Ages. Anglo-Saxon glass has been found across England during archaeological excavations of both settlement and cemetery sites. Glass in the Anglo-Saxon period was used in the manufacture of a range of objects including vessels, beads, windows and was also used in jewelry. Fr... | What 13th-century building is an example of stained glass walls? | {
"answer_start": [
590
],
"text": [
"Sainte-Chapelle"
]
} |
5729450a6aef051400154c32 | Glass | Glass was used extensively during the Middle Ages. Anglo-Saxon glass has been found across England during archaeological excavations of both settlement and cemetery sites. Glass in the Anglo-Saxon period was used in the manufacture of a range of objects including vessels, beads, windows and was also used in jewelry. Fr... | What did technological changes allow regular homes to have? | {
"answer_start": [
1201
],
"text": [
"larger windows"
]
} |
572946226aef051400154c38 | Glass | In the 20th century, new types of glass such as laminated glass, reinforced glass and glass bricks have increased the use of glass as a building material and resulted in new applications of glass. Multi-storey buildings are frequently constructed with curtain walls made almost entirely of glass. Similarly, laminated gl... | What type of glass is used in cars? | {
"answer_start": [
308
],
"text": [
"laminated"
]
} |
572946226aef051400154c39 | Glass | In the 20th century, new types of glass such as laminated glass, reinforced glass and glass bricks have increased the use of glass as a building material and resulted in new applications of glass. Multi-storey buildings are frequently constructed with curtain walls made almost entirely of glass. Similarly, laminated gl... | When did eyeglasses originate? | {
"answer_start": [
583
],
"text": [
"late Middle Ages"
]
} |
572946226aef051400154c3a | Glass | In the 20th century, new types of glass such as laminated glass, reinforced glass and glass bricks have increased the use of glass as a building material and resulted in new applications of glass. Multi-storey buildings are frequently constructed with curtain walls made almost entirely of glass. Similarly, laminated gl... | The walls of skyscrapers are often made of what material? | {
"answer_start": [
190
],
"text": [
"glass"
]
} |
572946226aef051400154c3b | Glass | In the 20th century, new types of glass such as laminated glass, reinforced glass and glass bricks have increased the use of glass as a building material and resulted in new applications of glass. Multi-storey buildings are frequently constructed with curtain walls made almost entirely of glass. Similarly, laminated gl... | What type of power systems use glass? | {
"answer_start": [
795
],
"text": [
"solar"
]
} |
572946226aef051400154c3c | Glass | In the 20th century, new types of glass such as laminated glass, reinforced glass and glass bricks have increased the use of glass as a building material and resulted in new applications of glass. Multi-storey buildings are frequently constructed with curtain walls made almost entirely of glass. Similarly, laminated gl... | What type of scientists rely on glass for distant observations? | {
"answer_start": [
669
],
"text": [
"astronomers"
]
} |
572947c3af94a219006aa247 | Glass | From the 19th century, there was a revival in many ancient glass-making techniques including cameo glass, achieved for the first time since the Roman Empire and initially mostly used for pieces in a neo-classical style. The Art Nouveau movement made great use of glass, with René Lalique, Émile Gallé, and Daum of Nancy ... | What famous lampmaker used glass? | {
"answer_start": [
420
],
"text": [
"Louis Comfort Tiffany"
]
} |
572947c3af94a219006aa248 | Glass | From the 19th century, there was a revival in many ancient glass-making techniques including cameo glass, achieved for the first time since the Roman Empire and initially mostly used for pieces in a neo-classical style. The Art Nouveau movement made great use of glass, with René Lalique, Émile Gallé, and Daum of Nancy ... | When did glassworkers begin to consider their products fine art? | {
"answer_start": [
659
],
"text": [
"1960"
]
} |
572947c3af94a219006aa249 | Glass | From the 19th century, there was a revival in many ancient glass-making techniques including cameo glass, achieved for the first time since the Roman Empire and initially mostly used for pieces in a neo-classical style. The Art Nouveau movement made great use of glass, with René Lalique, Émile Gallé, and Daum of Nancy ... | What type of glass did many Art Nouveau artists use? | {
"answer_start": [
373
],
"text": [
"cameo glass"
]
} |
572947c3af94a219006aa24a | Glass | From the 19th century, there was a revival in many ancient glass-making techniques including cameo glass, achieved for the first time since the Roman Empire and initially mostly used for pieces in a neo-classical style. The Art Nouveau movement made great use of glass, with René Lalique, Émile Gallé, and Daum of Nancy ... | When did mass production of glass art begin? | {
"answer_start": [
537
],
"text": [
"early 20th-century"
]
} |
572947c3af94a219006aa24b | Glass | From the 19th century, there was a revival in many ancient glass-making techniques including cameo glass, achieved for the first time since the Roman Empire and initially mostly used for pieces in a neo-classical style. The Art Nouveau movement made great use of glass, with René Lalique, Émile Gallé, and Daum of Nancy ... | What early civilization made cameo glass? | {
"answer_start": [
144
],
"text": [
"Roman Empire"
]
} |
572964476aef051400154de6 | Glass | Addition of lead(II) oxide lowers melting point, lowers viscosity of the melt, and increases refractive index. Lead oxide also facilitates solubility of other metal oxides and is used in colored glasses. The viscosity decrease of lead glass melt is very significant (roughly 100 times in comparison with soda glasses); t... | What makes glass melt at a lower temperature? | {
"answer_start": [
12
],
"text": [
"lead(II) oxide"
]
} |
572964476aef051400154de7 | Glass | Addition of lead(II) oxide lowers melting point, lowers viscosity of the melt, and increases refractive index. Lead oxide also facilitates solubility of other metal oxides and is used in colored glasses. The viscosity decrease of lead glass melt is very significant (roughly 100 times in comparison with soda glasses); t... | How much less viscous is lead glass compared with soda glass? | {
"answer_start": [
275
],
"text": [
"100 times"
]
} |
572964476aef051400154de8 | Glass | Addition of lead(II) oxide lowers melting point, lowers viscosity of the melt, and increases refractive index. Lead oxide also facilitates solubility of other metal oxides and is used in colored glasses. The viscosity decrease of lead glass melt is very significant (roughly 100 times in comparison with soda glasses); t... | Pb2+ causes lead glass to have what? | {
"answer_start": [
616
],
"text": [
"high electrical resistance"
]
} |
572964476aef051400154de9 | Glass | Addition of lead(II) oxide lowers melting point, lowers viscosity of the melt, and increases refractive index. Lead oxide also facilitates solubility of other metal oxides and is used in colored glasses. The viscosity decrease of lead glass melt is very significant (roughly 100 times in comparison with soda glasses); t... | Lead oxide makes it easier to dissolve what? | {
"answer_start": [
153
],
"text": [
"other metal oxides"
]
} |
57296639af94a219006aa389 | Glass | There are three classes of components for oxide glasses: network formers, intermediates, and modifiers. The network formers (silicon, boron, germanium) form a highly cross-linked network of chemical bonds. The intermediates (titanium, aluminium, zirconium, beryllium, magnesium, zinc) can act as both network formers and... | What components of glass for networks? | {
"answer_start": [
125
],
"text": [
"silicon, boron, germanium"
]
} |
57296639af94a219006aa38a | Glass | There are three classes of components for oxide glasses: network formers, intermediates, and modifiers. The network formers (silicon, boron, germanium) form a highly cross-linked network of chemical bonds. The intermediates (titanium, aluminium, zirconium, beryllium, magnesium, zinc) can act as both network formers and... | What type of components change the network's shape? | {
"answer_start": [
372
],
"text": [
"modifiers"
]
} |
57296639af94a219006aa38b | Glass | There are three classes of components for oxide glasses: network formers, intermediates, and modifiers. The network formers (silicon, boron, germanium) form a highly cross-linked network of chemical bonds. The intermediates (titanium, aluminium, zirconium, beryllium, magnesium, zinc) can act as both network formers and... | What type of component can both make and change networks? | {
"answer_start": [
210
],
"text": [
"intermediates"
]
} |
57296639af94a219006aa38c | Glass | There are three classes of components for oxide glasses: network formers, intermediates, and modifiers. The network formers (silicon, boron, germanium) form a highly cross-linked network of chemical bonds. The intermediates (titanium, aluminium, zirconium, beryllium, magnesium, zinc) can act as both network formers and... | What type of chemical attachment connects ions to the network? | {
"answer_start": [
551
],
"text": [
"covalent bond"
]
} |
57296766af94a219006aa3a3 | Glass | The alkali metal ions are small and mobile; their presence in glass allows a degree of electrical conductivity, especially in molten state or at high temperature. Their mobility decreases the chemical resistance of the glass, allowing leaching by water and facilitating corrosion. Alkaline earth ions, with their two pos... | What component gives glass the ability to conduct electricity? | {
"answer_start": [
4
],
"text": [
"alkali metal ions"
]
} |
57296766af94a219006aa3a4 | Glass | The alkali metal ions are small and mobile; their presence in glass allows a degree of electrical conductivity, especially in molten state or at high temperature. Their mobility decreases the chemical resistance of the glass, allowing leaching by water and facilitating corrosion. Alkaline earth ions, with their two pos... | How can glass be prevented from corroding? | {
"answer_start": [
729
],
"text": [
"dealkalization"
]
} |
57296766af94a219006aa3a5 | Glass | The alkali metal ions are small and mobile; their presence in glass allows a degree of electrical conductivity, especially in molten state or at high temperature. Their mobility decreases the chemical resistance of the glass, allowing leaching by water and facilitating corrosion. Alkaline earth ions, with their two pos... | What types of ions does typical glass have? | {
"answer_start": [
560
],
"text": [
"alkali and alkaline earth ions"
]
} |
57296766af94a219006aa3a6 | Glass | The alkali metal ions are small and mobile; their presence in glass allows a degree of electrical conductivity, especially in molten state or at high temperature. Their mobility decreases the chemical resistance of the glass, allowing leaching by water and facilitating corrosion. Alkaline earth ions, with their two pos... | Reaction with what causes dealkalization? | {
"answer_start": [
817
],
"text": [
"sulfur or fluorine compounds"
]
} |
57296766af94a219006aa3a7 | Glass | The alkali metal ions are small and mobile; their presence in glass allows a degree of electrical conductivity, especially in molten state or at high temperature. Their mobility decreases the chemical resistance of the glass, allowing leaching by water and facilitating corrosion. Alkaline earth ions, with their two pos... | What can alkaline ions in glass harm, in addition to electrical resistance? | {
"answer_start": [
914
],
"text": [
"loss tangent"
]
} |
5729689c3f37b31900478343 | Glass | New chemical glass compositions or new treatment techniques can be initially investigated in small-scale laboratory experiments. The raw materials for laboratory-scale glass melts are often different from those used in mass production because the cost factor has a low priority. In the laboratory mostly pure chemicals a... | What material is useful in glassmaking because of its slow evaporation? | {
"answer_start": [
688
],
"text": [
"sodium selenite"
]
} |
5729689c3f37b31900478344 | Glass | New chemical glass compositions or new treatment techniques can be initially investigated in small-scale laboratory experiments. The raw materials for laboratory-scale glass melts are often different from those used in mass production because the cost factor has a low priority. In the laboratory mostly pure chemicals a... | What containers are used for melting? | {
"answer_start": [
904
],
"text": [
"platinum crucibles"
]
} |
5729689c3f37b31900478345 | Glass | New chemical glass compositions or new treatment techniques can be initially investigated in small-scale laboratory experiments. The raw materials for laboratory-scale glass melts are often different from those used in mass production because the cost factor has a low priority. In the laboratory mostly pure chemicals a... | Why are different materials used in a lab than are used in factory production? | {
"answer_start": [
243
],
"text": [
"the cost factor has a low priority"
]
} |
5729689c3f37b31900478346 | Glass | New chemical glass compositions or new treatment techniques can be initially investigated in small-scale laboratory experiments. The raw materials for laboratory-scale glass melts are often different from those used in mass production because the cost factor has a low priority. In the laboratory mostly pure chemicals a... | What is the reason for crushing the glass and melting it again? | {
"answer_start": [
981
],
"text": [
"homogeneity"
]
} |
5729689c3f37b31900478347 | Glass | New chemical glass compositions or new treatment techniques can be initially investigated in small-scale laboratory experiments. The raw materials for laboratory-scale glass melts are often different from those used in mass production because the cost factor has a low priority. In the laboratory mostly pure chemicals a... | Why is glass annealed? | {
"answer_start": [
1170
],
"text": [
"to prevent breakage"
]
} |
57296ab01d046914007793e7 | Glass | In the past, small batches of amorphous metals with high surface area configurations (ribbons, wires, films, etc.) have been produced through the implementation of extremely rapid rates of cooling. This was initially termed "splat cooling" by doctoral student W. Klement at Caltech, who showed that cooling rates on the ... | Who coined the term "splat cooling"? | {
"answer_start": [
260
],
"text": [
"W. Klement"
]
} |
57296ab01d046914007793e8 | Glass | In the past, small batches of amorphous metals with high surface area configurations (ribbons, wires, films, etc.) have been produced through the implementation of extremely rapid rates of cooling. This was initially termed "splat cooling" by doctoral student W. Klement at Caltech, who showed that cooling rates on the ... | What are thick alloys made in layers called? | {
"answer_start": [
687
],
"text": [
"bulk metallic glasses"
]
} |
57296ab01d046914007793e9 | Glass | In the past, small batches of amorphous metals with high surface area configurations (ribbons, wires, films, etc.) have been produced through the implementation of extremely rapid rates of cooling. This was initially termed "splat cooling" by doctoral student W. Klement at Caltech, who showed that cooling rates on the ... | What does Liquidmetal Technologies use for their alloys? | {
"answer_start": [
758
],
"text": [
"zirconium"
]
} |
57296ab01d046914007793ea | Glass | In the past, small batches of amorphous metals with high surface area configurations (ribbons, wires, films, etc.) have been produced through the implementation of extremely rapid rates of cooling. This was initially termed "splat cooling" by doctoral student W. Klement at Caltech, who showed that cooling rates on the ... | What type of metal makes better alloys than traditional steel? | {
"answer_start": [
791
],
"text": [
"amorphous steel"
]
} |
57296ab01d046914007793eb | Glass | In the past, small batches of amorphous metals with high surface area configurations (ribbons, wires, films, etc.) have been produced through the implementation of extremely rapid rates of cooling. This was initially termed "splat cooling" by doctoral student W. Klement at Caltech, who showed that cooling rates on the ... | At what university was Klement a student? | {
"answer_start": [
274
],
"text": [
"Caltech"
]
} |
57296d396aef051400154e6a | Glass | In 2004, NIST researchers presented evidence that an isotropic non-crystalline metallic phase (dubbed "q-glass") could be grown from the melt. This phase is the first phase, or "primary phase," to form in the Al-Fe-Si system during rapid cooling. Interestingly, experimental evidence indicates that this phase forms by a... | Who showed that q-glass could be produced from a melt? | {
"answer_start": [
9
],
"text": [
"NIST researchers"
]
} |
57296d396aef051400154e6b | Glass | In 2004, NIST researchers presented evidence that an isotropic non-crystalline metallic phase (dubbed "q-glass") could be grown from the melt. This phase is the first phase, or "primary phase," to form in the Al-Fe-Si system during rapid cooling. Interestingly, experimental evidence indicates that this phase forms by a... | What shows that there is an inner surface between glass and melt? | {
"answer_start": [
610
],
"text": [
"nucleation barrier"
]
} |
57296d396aef051400154e6c | Glass | In 2004, NIST researchers presented evidence that an isotropic non-crystalline metallic phase (dubbed "q-glass") could be grown from the melt. This phase is the first phase, or "primary phase," to form in the Al-Fe-Si system during rapid cooling. Interestingly, experimental evidence indicates that this phase forms by a... | What is q-glass? | {
"answer_start": [
50
],
"text": [
"an isotropic non-crystalline metallic phase"
]
} |
57296d396aef051400154e6d | Glass | In 2004, NIST researchers presented evidence that an isotropic non-crystalline metallic phase (dubbed "q-glass") could be grown from the melt. This phase is the first phase, or "primary phase," to form in the Al-Fe-Si system during rapid cooling. Interestingly, experimental evidence indicates that this phase forms by a... | What kind of microscope shows that q-glass grows as separate particles? | {
"answer_start": [
345
],
"text": [
"Transmission electron"
]
} |
5729747d3f37b31900478405 | Glass | Glass-ceramic materials share many properties with both non-crystalline glass and crystalline ceramics. They are formed as a glass, and then partially crystallized by heat treatment. For example, the microstructure of whiteware ceramics frequently contains both amorphous and crystalline phases. Crystalline grains are o... | What word means that ceramics don't absorb liquids? | {
"answer_start": [
436
],
"text": [
"vitreous"
]
} |
5729747d3f37b31900478406 | Glass | Glass-ceramic materials share many properties with both non-crystalline glass and crystalline ceramics. They are formed as a glass, and then partially crystallized by heat treatment. For example, the microstructure of whiteware ceramics frequently contains both amorphous and crystalline phases. Crystalline grains are o... | What hardens glass-ceramics? | {
"answer_start": [
167
],
"text": [
"heat treatment"
]
} |
5729747d3f37b31900478407 | Glass | Glass-ceramic materials share many properties with both non-crystalline glass and crystalline ceramics. They are formed as a glass, and then partially crystallized by heat treatment. For example, the microstructure of whiteware ceramics frequently contains both amorphous and crystalline phases. Crystalline grains are o... | What materials do glass ceramics have a lot in common with? | {
"answer_start": [
56
],
"text": [
"non-crystalline glass and crystalline ceramics"
]
} |
5729765a6aef051400154f48 | Glass | The term mainly refers to a mix of lithium and aluminosilicates that yields an array of materials with interesting thermomechanical properties. The most commercially important of these have the distinction of being impervious to thermal shock. Thus, glass-ceramics have become extremely useful for countertop cooking. Th... | How high of a temperature change can glass-ceramics handle? | {
"answer_start": [
669
],
"text": [
"1000 °C"
]
} |
5729765a6aef051400154f49 | Glass | The term mainly refers to a mix of lithium and aluminosilicates that yields an array of materials with interesting thermomechanical properties. The most commercially important of these have the distinction of being impervious to thermal shock. Thus, glass-ceramics have become extremely useful for countertop cooking. Th... | Because of their heat resistance, glass-ceramics are especially suitable for what? | {
"answer_start": [
298
],
"text": [
"countertop cooking"
]
} |
5729765a6aef051400154f4a | Glass | The term mainly refers to a mix of lithium and aluminosilicates that yields an array of materials with interesting thermomechanical properties. The most commercially important of these have the distinction of being impervious to thermal shock. Thus, glass-ceramics have become extremely useful for countertop cooking. Th... | What is the most economically significant property of glass-ceramics? | {
"answer_start": [
215
],
"text": [
"impervious to thermal shock"
]
} |
5729765a6aef051400154f4b | Glass | The term mainly refers to a mix of lithium and aluminosilicates that yields an array of materials with interesting thermomechanical properties. The most commercially important of these have the distinction of being impervious to thermal shock. Thus, glass-ceramics have become extremely useful for countertop cooking. Th... | What ingredients give glass-ceramics its useful heat tolerance? | {
"answer_start": [
35
],
"text": [
"lithium and aluminosilicates"
]
} |
5729765a6aef051400154f4c | Glass | The term mainly refers to a mix of lithium and aluminosilicates that yields an array of materials with interesting thermomechanical properties. The most commercially important of these have the distinction of being impervious to thermal shock. Thus, glass-ceramics have become extremely useful for countertop cooking. Th... | What proportion of crystalline ceramics yields a product with a CTE of around 0? | {
"answer_start": [
479
],
"text": [
"~70%"
]
} |
572977e11d046914007794c1 | Glass | Mass production of glass window panes in the early twentieth century caused a similar effect. In glass factories, molten glass was poured onto a large cooling table and allowed to spread. The resulting glass is thicker at the location of the pour, located at the center of the large sheet. These sheets were cut into sma... | What were the areas at the center of an old sheet of glass called? | {
"answer_start": [
445
],
"text": [
"bull's-eyes"
]
} |
572977e11d046914007794c2 | Glass | Mass production of glass window panes in the early twentieth century caused a similar effect. In glass factories, molten glass was poured onto a large cooling table and allowed to spread. The resulting glass is thicker at the location of the pour, located at the center of the large sheet. These sheets were cut into sma... | In early 20th century glass production, the glass was thickest at what part of the sheet? | {
"answer_start": [
259
],
"text": [
"the center"
]
} |
572977e11d046914007794c3 | Glass | Mass production of glass window panes in the early twentieth century caused a similar effect. In glass factories, molten glass was poured onto a large cooling table and allowed to spread. The resulting glass is thicker at the location of the pour, located at the center of the large sheet. These sheets were cut into sma... | Currently window glass is made as what? | {
"answer_start": [
531
],
"text": [
"float glass"
]
} |
572977e11d046914007794c4 | Glass | Mass production of glass window panes in the early twentieth century caused a similar effect. In glass factories, molten glass was poured onto a large cooling table and allowed to spread. The resulting glass is thicker at the location of the pour, located at the center of the large sheet. These sheets were cut into sma... | How was the bull's-eye used? | {
"answer_start": [
459
],
"text": [
"for decorative effect"
]
} |
572979896aef051400154f7e | Glass | The observation that old windows are sometimes found to be thicker at the bottom than at the top is often offered as supporting evidence for the view that glass flows over a timescale of centuries, the assumption being that the glass has exhibited the liquid property of flowing from one shape to another. This assumptio... | What was the benefit of installing glass with the thick side at the bottom, in addition to avoiding water accumulation? | {
"answer_start": [
881
],
"text": [
"stability"
]
} |
572979896aef051400154f7f | Glass | The observation that old windows are sometimes found to be thicker at the bottom than at the top is often offered as supporting evidence for the view that glass flows over a timescale of centuries, the assumption being that the glass has exhibited the liquid property of flowing from one shape to another. This assumptio... | Who used to make window panes? | {
"answer_start": [
471
],
"text": [
"glassblowers"
]
} |
572979896aef051400154f80 | Glass | The observation that old windows are sometimes found to be thicker at the bottom than at the top is often offered as supporting evidence for the view that glass flows over a timescale of centuries, the assumption being that the glass has exhibited the liquid property of flowing from one shape to another. This assumptio... | What is the name for the glassmaking method that involved spinning it into sheets? | {
"answer_start": [
586
],
"text": [
"crown glass process"
]
} |
572979896aef051400154f81 | Glass | The observation that old windows are sometimes found to be thicker at the bottom than at the top is often offered as supporting evidence for the view that glass flows over a timescale of centuries, the assumption being that the glass has exhibited the liquid property of flowing from one shape to another. This assumptio... | The thickness at the bottom of glass panes was once taken as evidence that glass had features of what state of matter? | {
"answer_start": [
252
],
"text": [
"liquid"
]
} |
572979896aef051400154f82 | Glass | The observation that old windows are sometimes found to be thicker at the bottom than at the top is often offered as supporting evidence for the view that glass flows over a timescale of centuries, the assumption being that the glass has exhibited the liquid property of flowing from one shape to another. This assumptio... | When does glass stop moving like a liquid? | {
"answer_start": [
339
],
"text": [
"once solidified"
]
} |
572982021d046914007794ef | Glass | In physics, the standard definition of a glass (or vitreous solid) is a solid formed by rapid melt quenching. The term glass is often used to describe any amorphous solid that exhibits a glass transition temperature Tg. If the cooling is sufficiently rapid (relative to the characteristic crystallization time) then crys... | How is "glass" defined in physics? | {
"answer_start": [
70
],
"text": [
"a solid formed by rapid melt quenching"
]
} |
572982021d046914007794f0 | Glass | In physics, the standard definition of a glass (or vitreous solid) is a solid formed by rapid melt quenching. The term glass is often used to describe any amorphous solid that exhibits a glass transition temperature Tg. If the cooling is sufficiently rapid (relative to the characteristic crystallization time) then crys... | What is the tendency to make a glass when cooled called? | {
"answer_start": [
526
],
"text": [
"glass-forming ability"
]
} |
572982021d046914007794f1 | Glass | In physics, the standard definition of a glass (or vitreous solid) is a solid formed by rapid melt quenching. The term glass is often used to describe any amorphous solid that exhibits a glass transition temperature Tg. If the cooling is sufficiently rapid (relative to the characteristic crystallization time) then crys... | What must happen quickly for glass to form? | {
"answer_start": [
227
],
"text": [
"cooling"
]
} |
572982021d046914007794f2 | Glass | In physics, the standard definition of a glass (or vitreous solid) is a solid formed by rapid melt quenching. The term glass is often used to describe any amorphous solid that exhibits a glass transition temperature Tg. If the cooling is sufficiently rapid (relative to the characteristic crystallization time) then crys... | What predicts glass-forming ability? | {
"answer_start": [
586
],
"text": [
"rigidity theory"
]
} |
572984596aef051400154f9c | Glass | Some people consider glass to be a liquid due to its lack of a first-order phase transition where certain thermodynamic variables such as volume, entropy and enthalpy are discontinuous through the glass transition range. The glass transition may be described as analogous to a second-order phase transition where the int... | What does glass not have, leading some to think it is a liquid? | {
"answer_start": [
63
],
"text": [
"first-order phase transition"
]
} |
572984596aef051400154f9d | Glass | Some people consider glass to be a liquid due to its lack of a first-order phase transition where certain thermodynamic variables such as volume, entropy and enthalpy are discontinuous through the glass transition range. The glass transition may be described as analogous to a second-order phase transition where the int... | What theory isn't completely valid for glass? | {
"answer_start": [
437
],
"text": [
"equilibrium theory of phase transformations"
]
} |
572984596aef051400154f9e | Glass | Some people consider glass to be a liquid due to its lack of a first-order phase transition where certain thermodynamic variables such as volume, entropy and enthalpy are discontinuous through the glass transition range. The glass transition may be described as analogous to a second-order phase transition where the int... | Transition in glass is comparable to what? | {
"answer_start": [
275
],
"text": [
"a second-order phase transition"
]
} |
572988531d04691400779513 | Glass | Although the atomic structure of glass shares characteristics of the structure in a supercooled liquid, glass tends to behave as a solid below its glass transition temperature. A supercooled liquid behaves as a liquid, but it is below the freezing point of the material, and in some cases will crystallize almost instant... | Atomically, glass is similar to what? | {
"answer_start": [
82
],
"text": [
"a supercooled liquid"
]
} |
572988531d04691400779514 | Glass | Although the atomic structure of glass shares characteristics of the structure in a supercooled liquid, glass tends to behave as a solid below its glass transition temperature. A supercooled liquid behaves as a liquid, but it is below the freezing point of the material, and in some cases will crystallize almost instant... | What acts like a liquid but is under the freezing temperature? | {
"answer_start": [
177
],
"text": [
"A supercooled liquid"
]
} |
572988531d04691400779515 | Glass | Although the atomic structure of glass shares characteristics of the structure in a supercooled liquid, glass tends to behave as a solid below its glass transition temperature. A supercooled liquid behaves as a liquid, but it is below the freezing point of the material, and in some cases will crystallize almost instant... | Despite its atomic structure, cooled glass acts like what? | {
"answer_start": [
129
],
"text": [
"a solid"
]
} |
572988531d04691400779516 | Glass | Although the atomic structure of glass shares characteristics of the structure in a supercooled liquid, glass tends to behave as a solid below its glass transition temperature. A supercooled liquid behaves as a liquid, but it is below the freezing point of the material, and in some cases will crystallize almost instant... | In cooled glass, what types of movement stop? | {
"answer_start": [
694
],
"text": [
"rotational and translational"
]
} |
57293ad06aef051400154ba8 | Renewable_energy_commercialization | Public policy and political leadership helps to "level the playing field" and drive the wider acceptance of renewable energy technologies. Countries such as Germany, Denmark, and Spain have led the way in implementing innovative policies which has driven most of the growth over the past decade. As of 2014, Germany has ... | What drives the wider acceptance of renewable energy technologies? | {
"answer_start": [
0
],
"text": [
"Public policy and political leadership"
]
} |
57293ad06aef051400154ba9 | Renewable_energy_commercialization | Public policy and political leadership helps to "level the playing field" and drive the wider acceptance of renewable energy technologies. Countries such as Germany, Denmark, and Spain have led the way in implementing innovative policies which has driven most of the growth over the past decade. As of 2014, Germany has ... | Denmark has a committment to 100 percent renewable energy by what year? | {
"answer_start": [
456
],
"text": [
"2050"
]
} |
57293ad06aef051400154baa | Renewable_energy_commercialization | Public policy and political leadership helps to "level the playing field" and drive the wider acceptance of renewable energy technologies. Countries such as Germany, Denmark, and Spain have led the way in implementing innovative policies which has driven most of the growth over the past decade. As of 2014, Germany has ... | How many countries now have renewable energy policies? | {
"answer_start": [
476
],
"text": [
"144"
]
} |
57293b691d0469140077918d | Renewable_energy_commercialization | Total investment in renewable energy (including small hydro-electric projects) was $244 billion in 2012, down 12% from 2011 mainly due to dramatically lower solar prices and weakened US and EU markets. As a share of total investment in power plants, wind and solar PV grew from 14% in 2000 to over 60% in 2012. The top c... | How much was the total investment in renewable energy in 2012? | {
"answer_start": [
83
],
"text": [
"$244 billion"
]
} |
57293b691d0469140077918e | Renewable_energy_commercialization | Total investment in renewable energy (including small hydro-electric projects) was $244 billion in 2012, down 12% from 2011 mainly due to dramatically lower solar prices and weakened US and EU markets. As a share of total investment in power plants, wind and solar PV grew from 14% in 2000 to over 60% in 2012. The top c... | Why did the total investment in renewable energy go down in 2012? | {
"answer_start": [
138
],
"text": [
"dramatically lower solar prices"
]
} |
57293b691d0469140077918f | Renewable_energy_commercialization | Total investment in renewable energy (including small hydro-electric projects) was $244 billion in 2012, down 12% from 2011 mainly due to dramatically lower solar prices and weakened US and EU markets. As a share of total investment in power plants, wind and solar PV grew from 14% in 2000 to over 60% in 2012. The top c... | What six were the top countries for investment in recent years? | {
"answer_start": [
365
],
"text": [
"China, Germany, Spain, the United States, Italy, and Brazil"
]
} |
57293c241d046914007791a9 | Renewable_energy_commercialization | EU member countries have shown support for ambitious renewable energy goals. In 2010, Eurobarometer polled the twenty-seven EU member states about the target "to increase the share of renewable energy in the EU by 20 percent by 2020". Most people in all twenty-seven countries either approved of the target or called for... | Who has shown support for ambitious renewable energy goals? | {
"answer_start": [
0
],
"text": [
"EU member countries"
]
} |
57293c241d046914007791aa | Renewable_energy_commercialization | EU member countries have shown support for ambitious renewable energy goals. In 2010, Eurobarometer polled the twenty-seven EU member states about the target "to increase the share of renewable energy in the EU by 20 percent by 2020". Most people in all twenty-seven countries either approved of the target or called for... | What group polled the 27 EU member states in 2010? | {
"answer_start": [
86
],
"text": [
"Eurobarometer"
]
} |
57293c241d046914007791ab | Renewable_energy_commercialization | EU member countries have shown support for ambitious renewable energy goals. In 2010, Eurobarometer polled the twenty-seven EU member states about the target "to increase the share of renewable energy in the EU by 20 percent by 2020". Most people in all twenty-seven countries either approved of the target or called for... | The goal was to increase the share of renewable energy in the EU by 20 percent in what year? | {
"answer_start": [
228
],
"text": [
"2020"
]
} |
57293d583f37b3190047816d | Renewable_energy_commercialization | By the end of 2011, total renewable power capacity worldwide exceeded 1,360 GW, up 8%. Renewables producing electricity accounted for almost half of the 208 GW of capacity added globally during 2011. Wind and solar photovoltaics (PV) accounted for almost 40% and 30% . Based on REN21's 2014 report, renewables contribute... | By the end of 2011, total renewable power capacity worldwide exceeded what number? | {
"answer_start": [
70
],
"text": [
"1,360 GW"
]
} |
57293d583f37b3190047816e | Renewable_energy_commercialization | By the end of 2011, total renewable power capacity worldwide exceeded 1,360 GW, up 8%. Renewables producing electricity accounted for almost half of the 208 GW of capacity added globally during 2011. Wind and solar photovoltaics (PV) accounted for almost 40% and 30% . Based on REN21's 2014 report, renewables contribute... | Renewables contributed what percentage to our energy consumption? | {
"answer_start": [
322
],
"text": [
"19 percent"
]
} |
57293d583f37b3190047816f | Renewable_energy_commercialization | By the end of 2011, total renewable power capacity worldwide exceeded 1,360 GW, up 8%. Renewables producing electricity accounted for almost half of the 208 GW of capacity added globally during 2011. Wind and solar photovoltaics (PV) accounted for almost 40% and 30% . Based on REN21's 2014 report, renewables contribute... | Renewables contributed what percentage to our electricity generation? | {
"answer_start": [
363
],
"text": [
"22 percent"
]
} |
57293ff51d046914007791f3 | Renewable_energy_commercialization | During the five-years from the end of 2004 through 2009, worldwide renewable energy capacity grew at rates of 10–60 percent annually for many technologies. In 2011, UN under-secretary general Achim Steiner said: "The continuing growth in this core segment of the green economy is not happening by chance. The combination... | Who was the UN under-secretary in 2011? | {
"answer_start": [
192
],
"text": [
"Achim Steiner"
]
} |
57293ff51d046914007791f4 | Renewable_energy_commercialization | During the five-years from the end of 2004 through 2009, worldwide renewable energy capacity grew at rates of 10–60 percent annually for many technologies. In 2011, UN under-secretary general Achim Steiner said: "The continuing growth in this core segment of the green economy is not happening by chance. The combination... | Between what years did worldwide renewable energy capacity grow at rates of 10 to 60 percent annually? | {
"answer_start": [
38
],
"text": [
"2004 through 2009"
]
} |
57293ff51d046914007791f5 | Renewable_energy_commercialization | During the five-years from the end of 2004 through 2009, worldwide renewable energy capacity grew at rates of 10–60 percent annually for many technologies. In 2011, UN under-secretary general Achim Steiner said: "The continuing growth in this core segment of the green economy is not happening by chance. The combination... | Who is Achim Steiner? | {
"answer_start": [
165
],
"text": [
"UN under-secretary general"
]
} |
572941266aef051400154c0a | Renewable_energy_commercialization | According to a 2011 projection by the International Energy Agency, solar power plants may produce most of the world's electricity within 50 years, significantly reducing the emissions of greenhouse gases that harm the environment. The IEA has said: "Photovoltaic and solar-thermal plants may meet most of the world's dem... | Which group projected that solar plant may produce most of the world's electricity within 50 years? | {
"answer_start": [
38
],
"text": [
"International Energy Agency"
]
} |
572941266aef051400154c0b | Renewable_energy_commercialization | According to a 2011 projection by the International Energy Agency, solar power plants may produce most of the world's electricity within 50 years, significantly reducing the emissions of greenhouse gases that harm the environment. The IEA has said: "Photovoltaic and solar-thermal plants may meet most of the world's dem... | Photovoltaic and solar-thermal plants may meet most of the world's demand for electricity by what year? | {
"answer_start": [
343
],
"text": [
"2060"
]
} |
572941266aef051400154c0c | Renewable_energy_commercialization | According to a 2011 projection by the International Energy Agency, solar power plants may produce most of the world's electricity within 50 years, significantly reducing the emissions of greenhouse gases that harm the environment. The IEA has said: "Photovoltaic and solar-thermal plants may meet most of the world's dem... | Photovoltaic and solar-thermal plants may meet how much of the world's energy needs by 2060? | {
"answer_start": [
354
],
"text": [
"half"
]
} |
572942721d0469140077920d | Renewable_energy_commercialization | In 2013, China led the world in renewable energy production, with a total capacity of 378 GW, mainly from hydroelectric and wind power. As of 2014, China leads the world in the production and use of wind power, solar photovoltaic power and smart grid technologies, generating almost as much water, wind and solar energy ... | Who led the world in renewable energy production in 2013? | {
"answer_start": [
9
],
"text": [
"China"
]
} |
572942721d0469140077920e | Renewable_energy_commercialization | In 2013, China led the world in renewable energy production, with a total capacity of 378 GW, mainly from hydroelectric and wind power. As of 2014, China leads the world in the production and use of wind power, solar photovoltaic power and smart grid technologies, generating almost as much water, wind and solar energy ... | Since what year has production of solar cells in China expanded 100-fold? | {
"answer_start": [
480
],
"text": [
"2005"
]
} |
572942721d0469140077920f | Renewable_energy_commercialization | In 2013, China led the world in renewable energy production, with a total capacity of 378 GW, mainly from hydroelectric and wind power. As of 2014, China leads the world in the production and use of wind power, solar photovoltaic power and smart grid technologies, generating almost as much water, wind and solar energy ... | What is the main driver of reduced costs? | {
"answer_start": [
716
],
"text": [
"market expansion"
]
} |
572943176aef051400154c1e | Renewable_energy_commercialization | Renewable energy technologies are getting cheaper, through technological change and through the benefits of mass production and market competition. A 2011 IEA report said: "A portfolio of renewable energy technologies is becoming cost-competitive in an increasingly broad range of circumstances, in some cases providing ... | What is getting cheaper as a result of technilogical change? | {
"answer_start": [
0
],
"text": [
"Renewable energy technologies"
]
} |
572943176aef051400154c1f | Renewable_energy_commercialization | Renewable energy technologies are getting cheaper, through technological change and through the benefits of mass production and market competition. A 2011 IEA report said: "A portfolio of renewable energy technologies is becoming cost-competitive in an increasingly broad range of circumstances, in some cases providing ... | As of what year have there been substantial reductions in the cost of solar and wind technologies? | {
"answer_start": [
504
],
"text": [
"2011"
]
} |
572943176aef051400154c20 | Renewable_energy_commercialization | Renewable energy technologies are getting cheaper, through technological change and through the benefits of mass production and market competition. A 2011 IEA report said: "A portfolio of renewable energy technologies is becoming cost-competitive in an increasingly broad range of circumstances, in some cases providing ... | What group stated that "cost reductions in critical technologies, such as wind and solar, are set to continue?" | {
"answer_start": [
155
],
"text": [
"IEA"
]
} |
5729442b3f37b319004781db | Renewable_energy_commercialization | Renewable energy is also the most economic solution for new grid-connected capacity in areas with good resources. As the cost of renewable power falls, the scope of economically viable applications increases. Renewable technologies are now often the most economic solution for new generating capacity. Where "oil-fired g... | What is the most economic solution for new grid-connected capacity in areas with good resources? | {
"answer_start": [
0
],
"text": [
"Renewable energy"
]
} |
5729442b3f37b319004781dc | Renewable_energy_commercialization | Renewable energy is also the most economic solution for new grid-connected capacity in areas with good resources. As the cost of renewable power falls, the scope of economically viable applications increases. Renewable technologies are now often the most economic solution for new generating capacity. Where "oil-fired g... | What happens as the scope of economically viable applications increases? | {
"answer_start": [
117
],
"text": [
"the cost of renewable power falls"
]
} |
5729442b3f37b319004781dd | Renewable_energy_commercialization | Renewable energy is also the most economic solution for new grid-connected capacity in areas with good resources. As the cost of renewable power falls, the scope of economically viable applications increases. Renewable technologies are now often the most economic solution for new generating capacity. Where "oil-fired g... | What are now often the most economic solution for new generating capacity? | {
"answer_start": [
209
],
"text": [
"Renewable technologies"
]
} |
572944eb1d04691400779223 | Renewable_energy_commercialization | Biomass for heat and power is a fully mature technology which offers a ready disposal mechanism for municipal, agricultural, and industrial organic wastes. However, the industry has remained relatively stagnant over the decade to 2007, even though demand for biomass (mostly wood) continues to grow in many developing co... | What is one problem with biomass? | {
"answer_start": [
368
],
"text": [
"material directly combusted in cook stoves produces pollutants"
]
} |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.