id stringlengths 24 24 | title stringclasses 442 values | context stringlengths 151 3.71k | question stringlengths 12 270 | answers dict |
|---|---|---|---|---|
56fa04db8f12f31900630099 | Wood | If a tree grows all its life in the open and the conditions of soil and site remain unchanged, it will make its most rapid growth in youth, and gradually decline. The annual rings of growth are for many years quite wide, but later they become narrower and narrower. Since each succeeding ring is laid down on the outside of the wood previously formed, it follows that unless a tree materially increases its production of wood from year to year, the rings must necessarily become thinner as the trunk gets wider. As a tree reaches maturity its crown becomes more open and the annual wood production is lessened, thereby reducing still more the width of the growth rings. In the case of forest-grown trees so much depends upon the competition of the trees in their struggle for light and nourishment that periods of rapid and slow growth may alternate. Some trees, such as southern oaks, maintain the same width of ring for hundreds of years. Upon the whole, however, as a tree gets larger in diameter the width of the growth rings decreases. | Along with nutrients, what do trees growing in forests have to compete for? | {
"answer_start": [
776
],
"text": [
"light"
]
} |
56fa0745f34c681400b0bf5d | Wood | Different pieces of wood cut from a large tree may differ decidedly, particularly if the tree is big and mature. In some trees, the wood laid on late in the life of a tree is softer, lighter, weaker, and more even-textured than that produced earlier, but in other trees, the reverse applies. This may or may not correspond to heartwood and sapwood. In a large log the sapwood, because of the time in the life of the tree when it was grown, may be inferior in hardness, strength, and toughness to equally sound heartwood from the same log. In a smaller tree, the reverse may be true. | When a big tree is cut up, will the pieces of wood differ or all be the same? | {
"answer_start": [
51
],
"text": [
"differ"
]
} |
56fa0745f34c681400b0bf5e | Wood | Different pieces of wood cut from a large tree may differ decidedly, particularly if the tree is big and mature. In some trees, the wood laid on late in the life of a tree is softer, lighter, weaker, and more even-textured than that produced earlier, but in other trees, the reverse applies. This may or may not correspond to heartwood and sapwood. In a large log the sapwood, because of the time in the life of the tree when it was grown, may be inferior in hardness, strength, and toughness to equally sound heartwood from the same log. In a smaller tree, the reverse may be true. | In a large log, will the heartwood or sapwood usually be stronger and tougher? | {
"answer_start": [
510
],
"text": [
"heartwood"
]
} |
56fa0745f34c681400b0bf5f | Wood | Different pieces of wood cut from a large tree may differ decidedly, particularly if the tree is big and mature. In some trees, the wood laid on late in the life of a tree is softer, lighter, weaker, and more even-textured than that produced earlier, but in other trees, the reverse applies. This may or may not correspond to heartwood and sapwood. In a large log the sapwood, because of the time in the life of the tree when it was grown, may be inferior in hardness, strength, and toughness to equally sound heartwood from the same log. In a smaller tree, the reverse may be true. | If you need really hard, strong wood from a small tree, would it likely be better to use the heartwood or sapwood? | {
"answer_start": [
368
],
"text": [
"sapwood"
]
} |
56fa0745f34c681400b0bf60 | Wood | Different pieces of wood cut from a large tree may differ decidedly, particularly if the tree is big and mature. In some trees, the wood laid on late in the life of a tree is softer, lighter, weaker, and more even-textured than that produced earlier, but in other trees, the reverse applies. This may or may not correspond to heartwood and sapwood. In a large log the sapwood, because of the time in the life of the tree when it was grown, may be inferior in hardness, strength, and toughness to equally sound heartwood from the same log. In a smaller tree, the reverse may be true. | Besides big trees, what trees are more likely to have a range of different kinds of wood? | {
"answer_start": [
105
],
"text": [
"mature"
]
} |
56fa09098f12f3190063009f | Wood | In species which show a distinct difference between heartwood and sapwood the natural color of heartwood is usually darker than that of the sapwood, and very frequently the contrast is conspicuous (see section of yew log above). This is produced by deposits in the heartwood of chemical substances, so that a dramatic color difference does not mean a dramatic difference in the mechanical properties of heartwood and sapwood, although there may be a dramatic chemical difference. | When trees have a visible difference in color between sapwood and heartwood, which is darker? | {
"answer_start": [
95
],
"text": [
"heartwood"
]
} |
56fa09098f12f319006300a0 | Wood | In species which show a distinct difference between heartwood and sapwood the natural color of heartwood is usually darker than that of the sapwood, and very frequently the contrast is conspicuous (see section of yew log above). This is produced by deposits in the heartwood of chemical substances, so that a dramatic color difference does not mean a dramatic difference in the mechanical properties of heartwood and sapwood, although there may be a dramatic chemical difference. | What is deposited naturally in heartwood that changes its color? | {
"answer_start": [
278
],
"text": [
"chemical substances"
]
} |
56fa09098f12f319006300a1 | Wood | In species which show a distinct difference between heartwood and sapwood the natural color of heartwood is usually darker than that of the sapwood, and very frequently the contrast is conspicuous (see section of yew log above). This is produced by deposits in the heartwood of chemical substances, so that a dramatic color difference does not mean a dramatic difference in the mechanical properties of heartwood and sapwood, although there may be a dramatic chemical difference. | Is the color difference between heartwood and sapwood usually very subtle or conspicuous? | {
"answer_start": [
185
],
"text": [
"conspicuous"
]
} |
56fa09098f12f319006300a2 | Wood | In species which show a distinct difference between heartwood and sapwood the natural color of heartwood is usually darker than that of the sapwood, and very frequently the contrast is conspicuous (see section of yew log above). This is produced by deposits in the heartwood of chemical substances, so that a dramatic color difference does not mean a dramatic difference in the mechanical properties of heartwood and sapwood, although there may be a dramatic chemical difference. | What type of properties of heartwood and sapwood is often the same even if their colors are very different? | {
"answer_start": [
378
],
"text": [
"mechanical"
]
} |
56fa09098f12f319006300a3 | Wood | In species which show a distinct difference between heartwood and sapwood the natural color of heartwood is usually darker than that of the sapwood, and very frequently the contrast is conspicuous (see section of yew log above). This is produced by deposits in the heartwood of chemical substances, so that a dramatic color difference does not mean a dramatic difference in the mechanical properties of heartwood and sapwood, although there may be a dramatic chemical difference. | Although heartwood and sapwood might be similar mechanically, if their colors are very different, what other type of difference would they have? | {
"answer_start": [
459
],
"text": [
"chemical"
]
} |
56fa0bfa8f12f319006300b3 | Wood | Some experiments on very resinous Longleaf Pine specimens indicate an increase in strength, due to the resin which increases the strength when dry. Such resin-saturated heartwood is called "fat lighter". Structures built of fat lighter are almost impervious to rot and termites; however they are very flammable. Stumps of old longleaf pines are often dug, split into small pieces and sold as kindling for fires. Stumps thus dug may actually remain a century or more since being cut. Spruce impregnated with crude resin and dried is also greatly increased in strength thereby. | What type of tree has resin that makes it stronger when it dries? | {
"answer_start": [
34
],
"text": [
"Longleaf Pine"
]
} |
56fa0bfa8f12f319006300b4 | Wood | Some experiments on very resinous Longleaf Pine specimens indicate an increase in strength, due to the resin which increases the strength when dry. Such resin-saturated heartwood is called "fat lighter". Structures built of fat lighter are almost impervious to rot and termites; however they are very flammable. Stumps of old longleaf pines are often dug, split into small pieces and sold as kindling for fires. Stumps thus dug may actually remain a century or more since being cut. Spruce impregnated with crude resin and dried is also greatly increased in strength thereby. | What's the funny name for resin-saturated heartwood? | {
"answer_start": [
190
],
"text": [
"fat lighter"
]
} |
56fa0bfa8f12f319006300b5 | Wood | Some experiments on very resinous Longleaf Pine specimens indicate an increase in strength, due to the resin which increases the strength when dry. Such resin-saturated heartwood is called "fat lighter". Structures built of fat lighter are almost impervious to rot and termites; however they are very flammable. Stumps of old longleaf pines are often dug, split into small pieces and sold as kindling for fires. Stumps thus dug may actually remain a century or more since being cut. Spruce impregnated with crude resin and dried is also greatly increased in strength thereby. | What is fat lighter practically impervious to in addition to termites? | {
"answer_start": [
261
],
"text": [
"rot"
]
} |
56fa0bfa8f12f319006300b6 | Wood | Some experiments on very resinous Longleaf Pine specimens indicate an increase in strength, due to the resin which increases the strength when dry. Such resin-saturated heartwood is called "fat lighter". Structures built of fat lighter are almost impervious to rot and termites; however they are very flammable. Stumps of old longleaf pines are often dug, split into small pieces and sold as kindling for fires. Stumps thus dug may actually remain a century or more since being cut. Spruce impregnated with crude resin and dried is also greatly increased in strength thereby. | If spruce is shot full of crude resin and dried, which of its properties is increased? | {
"answer_start": [
558
],
"text": [
"strength"
]
} |
56fa0bfa8f12f319006300b7 | Wood | Some experiments on very resinous Longleaf Pine specimens indicate an increase in strength, due to the resin which increases the strength when dry. Such resin-saturated heartwood is called "fat lighter". Structures built of fat lighter are almost impervious to rot and termites; however they are very flammable. Stumps of old longleaf pines are often dug, split into small pieces and sold as kindling for fires. Stumps thus dug may actually remain a century or more since being cut. Spruce impregnated with crude resin and dried is also greatly increased in strength thereby. | Since it's highly flammable, what do people often use little pieces of longleaf pine tree stumps for? | {
"answer_start": [
392
],
"text": [
"kindling"
]
} |
56fa0e0df34c681400b0bf8d | Wood | Since the latewood of a growth ring is usually darker in color than the earlywood, this fact may be used in judging the density, and therefore the hardness and strength of the material. This is particularly the case with coniferous woods. In ring-porous woods the vessels of the early wood not infrequently appear on a finished surface as darker than the denser latewood, though on cross sections of heartwood the reverse is commonly true. Except in the manner just stated the color of wood is no indication of strength. | Which of the wood in a growth ring is usually darker? | {
"answer_start": [
10
],
"text": [
"latewood"
]
} |
56fa0e0df34c681400b0bf8e | Wood | Since the latewood of a growth ring is usually darker in color than the earlywood, this fact may be used in judging the density, and therefore the hardness and strength of the material. This is particularly the case with coniferous woods. In ring-porous woods the vessels of the early wood not infrequently appear on a finished surface as darker than the denser latewood, though on cross sections of heartwood the reverse is commonly true. Except in the manner just stated the color of wood is no indication of strength. | Which property of a tree's wood that gives clues about its strength and hardness can be judged by it's color? | {
"answer_start": [
120
],
"text": [
"density"
]
} |
56fa0e0df34c681400b0bf8f | Wood | Since the latewood of a growth ring is usually darker in color than the earlywood, this fact may be used in judging the density, and therefore the hardness and strength of the material. This is particularly the case with coniferous woods. In ring-porous woods the vessels of the early wood not infrequently appear on a finished surface as darker than the denser latewood, though on cross sections of heartwood the reverse is commonly true. Except in the manner just stated the color of wood is no indication of strength. | What category of trees show this difference greatly? | {
"answer_start": [
221
],
"text": [
"coniferous"
]
} |
56fa0e0df34c681400b0bf90 | Wood | Since the latewood of a growth ring is usually darker in color than the earlywood, this fact may be used in judging the density, and therefore the hardness and strength of the material. This is particularly the case with coniferous woods. In ring-porous woods the vessels of the early wood not infrequently appear on a finished surface as darker than the denser latewood, though on cross sections of heartwood the reverse is commonly true. Except in the manner just stated the color of wood is no indication of strength. | What type of woods might sometimes appear to have darker earlywood on a finished surface? | {
"answer_start": [
242
],
"text": [
"ring-porous"
]
} |
56fa0e0df34c681400b0bf91 | Wood | Since the latewood of a growth ring is usually darker in color than the earlywood, this fact may be used in judging the density, and therefore the hardness and strength of the material. This is particularly the case with coniferous woods. In ring-porous woods the vessels of the early wood not infrequently appear on a finished surface as darker than the denser latewood, though on cross sections of heartwood the reverse is commonly true. Except in the manner just stated the color of wood is no indication of strength. | With the exception of earlywood/latewood difference in some types of trees, how much of an indication of strength is a wood's color? | {
"answer_start": [
494
],
"text": [
"no indication"
]
} |
56fa104bf34c681400b0bf97 | Wood | Abnormal discoloration of wood often denotes a diseased condition, indicating unsoundness. The black check in western hemlock is the result of insect attacks. The reddish-brown streaks so common in hickory and certain other woods are mostly the result of injury by birds. The discoloration is merely an indication of an injury, and in all probability does not of itself affect the properties of the wood. Certain rot-producing fungi impart to wood characteristic colors which thus become symptomatic of weakness; however an attractive effect known as spalting produced by this process is often considered a desirable characteristic. Ordinary sap-staining is due to fungal growth, but does not necessarily produce a weakening effect. | What condition does an abnormal color usually indicate in wood? | {
"answer_start": [
47
],
"text": [
"diseased"
]
} |
56fa104bf34c681400b0bf98 | Wood | Abnormal discoloration of wood often denotes a diseased condition, indicating unsoundness. The black check in western hemlock is the result of insect attacks. The reddish-brown streaks so common in hickory and certain other woods are mostly the result of injury by birds. The discoloration is merely an indication of an injury, and in all probability does not of itself affect the properties of the wood. Certain rot-producing fungi impart to wood characteristic colors which thus become symptomatic of weakness; however an attractive effect known as spalting produced by this process is often considered a desirable characteristic. Ordinary sap-staining is due to fungal growth, but does not necessarily produce a weakening effect. | What other property can you assume of wood that is diseased? | {
"answer_start": [
78
],
"text": [
"unsoundness"
]
} |
56fa104bf34c681400b0bf99 | Wood | Abnormal discoloration of wood often denotes a diseased condition, indicating unsoundness. The black check in western hemlock is the result of insect attacks. The reddish-brown streaks so common in hickory and certain other woods are mostly the result of injury by birds. The discoloration is merely an indication of an injury, and in all probability does not of itself affect the properties of the wood. Certain rot-producing fungi impart to wood characteristic colors which thus become symptomatic of weakness; however an attractive effect known as spalting produced by this process is often considered a desirable characteristic. Ordinary sap-staining is due to fungal growth, but does not necessarily produce a weakening effect. | What causes the black checked pattern in the wood of western hemlocks? | {
"answer_start": [
143
],
"text": [
"insect attacks"
]
} |
56fa104bf34c681400b0bf9a | Wood | Abnormal discoloration of wood often denotes a diseased condition, indicating unsoundness. The black check in western hemlock is the result of insect attacks. The reddish-brown streaks so common in hickory and certain other woods are mostly the result of injury by birds. The discoloration is merely an indication of an injury, and in all probability does not of itself affect the properties of the wood. Certain rot-producing fungi impart to wood characteristic colors which thus become symptomatic of weakness; however an attractive effect known as spalting produced by this process is often considered a desirable characteristic. Ordinary sap-staining is due to fungal growth, but does not necessarily produce a weakening effect. | What animals cause the reddish-brown streaks of color in hickory wood? | {
"answer_start": [
265
],
"text": [
"birds"
]
} |
56fa104bf34c681400b0bf9b | Wood | Abnormal discoloration of wood often denotes a diseased condition, indicating unsoundness. The black check in western hemlock is the result of insect attacks. The reddish-brown streaks so common in hickory and certain other woods are mostly the result of injury by birds. The discoloration is merely an indication of an injury, and in all probability does not of itself affect the properties of the wood. Certain rot-producing fungi impart to wood characteristic colors which thus become symptomatic of weakness; however an attractive effect known as spalting produced by this process is often considered a desirable characteristic. Ordinary sap-staining is due to fungal growth, but does not necessarily produce a weakening effect. | What's the name for the pretty coloring effect caused in some wood by rot-producing fungi? | {
"answer_start": [
551
],
"text": [
"spalting"
]
} |
56fa115c8f12f319006300bd | Wood | In heartwood it occurs only in the first and last forms. Wood that is thoroughly air-dried retains 8–16% of the water in the cell walls, and none, or practically none, in the other forms. Even oven-dried wood retains a small percentage of moisture, but for all except chemical purposes, may be considered absolutely dry. | What does wood retain in its cell walls despite being air-dried? | {
"answer_start": [
112
],
"text": [
"water"
]
} |
56fa115c8f12f319006300be | Wood | In heartwood it occurs only in the first and last forms. Wood that is thoroughly air-dried retains 8–16% of the water in the cell walls, and none, or practically none, in the other forms. Even oven-dried wood retains a small percentage of moisture, but for all except chemical purposes, may be considered absolutely dry. | Air-dried wood keeps up to what percentage of the water in its cell walls? | {
"answer_start": [
101
],
"text": [
"16"
]
} |
56fa115c8f12f319006300bf | Wood | In heartwood it occurs only in the first and last forms. Wood that is thoroughly air-dried retains 8–16% of the water in the cell walls, and none, or practically none, in the other forms. Even oven-dried wood retains a small percentage of moisture, but for all except chemical purposes, may be considered absolutely dry. | What kind of dried wood retains a small quantity of water but is considered absolutely dry? | {
"answer_start": [
193
],
"text": [
"oven-dried"
]
} |
56fa142af34c681400b0bfa1 | Wood | The general effect of the water content upon the wood substance is to render it softer and more pliable. A similar effect of common observation is in the softening action of water on rawhide, paper, or cloth. Within certain limits, the greater the water content, the greater its softening effect. | Often the water in wood makes it more pliable and what else? | {
"answer_start": [
80
],
"text": [
"softer"
]
} |
56fa142af34c681400b0bfa2 | Wood | The general effect of the water content upon the wood substance is to render it softer and more pliable. A similar effect of common observation is in the softening action of water on rawhide, paper, or cloth. Within certain limits, the greater the water content, the greater its softening effect. | What material sometimes used for dog chews reacts similarly to wood because of its water content? | {
"answer_start": [
183
],
"text": [
"rawhide"
]
} |
56fa142af34c681400b0bfa3 | Wood | The general effect of the water content upon the wood substance is to render it softer and more pliable. A similar effect of common observation is in the softening action of water on rawhide, paper, or cloth. Within certain limits, the greater the water content, the greater its softening effect. | What material we use to write or print on, like wood, becomes softer and more pliable when wet? | {
"answer_start": [
192
],
"text": [
"paper"
]
} |
56fa142af34c681400b0bfa4 | Wood | The general effect of the water content upon the wood substance is to render it softer and more pliable. A similar effect of common observation is in the softening action of water on rawhide, paper, or cloth. Within certain limits, the greater the water content, the greater its softening effect. | When water content increases within certain limits in wood, does is have a less or greater softening effect? | {
"answer_start": [
267
],
"text": [
"greater"
]
} |
56fa142af34c681400b0bfa5 | Wood | The general effect of the water content upon the wood substance is to render it softer and more pliable. A similar effect of common observation is in the softening action of water on rawhide, paper, or cloth. Within certain limits, the greater the water content, the greater its softening effect. | What type of action does water create in cloth? | {
"answer_start": [
154
],
"text": [
"softening"
]
} |
56fa160f8f12f319006300c3 | Wood | Drying produces a decided increase in the strength of wood, particularly in small specimens. An extreme example is the case of a completely dry spruce block 5 cm in section, which will sustain a permanent load four times as great as a green (undried) block of the same size will. | What will drying often increase in wood? | {
"answer_start": [
42
],
"text": [
"strength"
]
} |
56fa160f8f12f319006300c4 | Wood | Drying produces a decided increase in the strength of wood, particularly in small specimens. An extreme example is the case of a completely dry spruce block 5 cm in section, which will sustain a permanent load four times as great as a green (undried) block of the same size will. | What color is also used interchangeably with "undried" for wood? | {
"answer_start": [
235
],
"text": [
"green"
]
} |
56fa160f8f12f319006300c5 | Wood | Drying produces a decided increase in the strength of wood, particularly in small specimens. An extreme example is the case of a completely dry spruce block 5 cm in section, which will sustain a permanent load four times as great as a green (undried) block of the same size will. | What type of wood can hold four times as much of a load when dried? | {
"answer_start": [
144
],
"text": [
"spruce"
]
} |
56fa184cf34c681400b0bfab | Wood | The greatest strength increase due to drying is in the ultimate crushing strength, and strength at elastic limit in endwise compression; these are followed by the modulus of rupture, and stress at elastic limit in cross-bending, while the modulus of elasticity is least affected. | What type of "ultimate" strength is one of the two types increased the most by drying wood? | {
"answer_start": [
64
],
"text": [
"crushing"
]
} |
56fa184cf34c681400b0bfac | Wood | The greatest strength increase due to drying is in the ultimate crushing strength, and strength at elastic limit in endwise compression; these are followed by the modulus of rupture, and stress at elastic limit in cross-bending, while the modulus of elasticity is least affected. | What property of wood is least affected by drying? | {
"answer_start": [
250
],
"text": [
"elasticity"
]
} |
56fa184cf34c681400b0bfad | Wood | The greatest strength increase due to drying is in the ultimate crushing strength, and strength at elastic limit in endwise compression; these are followed by the modulus of rupture, and stress at elastic limit in cross-bending, while the modulus of elasticity is least affected. | Is strength at elastic limit in endwise compression or stress at elastic limit in cross-bending increased more by drying wood? | {
"answer_start": [
87
],
"text": [
"strength at elastic limit in endwise compression"
]
} |
56fa184cf34c681400b0bfae | Wood | The greatest strength increase due to drying is in the ultimate crushing strength, and strength at elastic limit in endwise compression; these are followed by the modulus of rupture, and stress at elastic limit in cross-bending, while the modulus of elasticity is least affected. | Is the strength of the modulus of rupture or elasticity increased more when wood is dried? | {
"answer_start": [
163
],
"text": [
"modulus of rupture"
]
} |
56fa19cc8f12f319006300c9 | Wood | Wood is a heterogeneous, hygroscopic, cellular and anisotropic material. It consists of cells, and the cell walls are composed of micro-fibrils of cellulose (40% – 50%) and hemicellulose (15% – 25%) impregnated with lignin (15% – 30%). | Along with hygroscopic, cellular, and anisotropic, how is the material of wood described? | {
"answer_start": [
10
],
"text": [
"heterogeneous"
]
} |
56fa19cc8f12f319006300ca | Wood | Wood is a heterogeneous, hygroscopic, cellular and anisotropic material. It consists of cells, and the cell walls are composed of micro-fibrils of cellulose (40% – 50%) and hemicellulose (15% – 25%) impregnated with lignin (15% – 30%). | What does wood consist of? | {
"answer_start": [
88
],
"text": [
"cells"
]
} |
56fa19cc8f12f319006300cb | Wood | Wood is a heterogeneous, hygroscopic, cellular and anisotropic material. It consists of cells, and the cell walls are composed of micro-fibrils of cellulose (40% – 50%) and hemicellulose (15% – 25%) impregnated with lignin (15% – 30%). | What part of wood's cells are composed of cellulose and hemicellulose? | {
"answer_start": [
108
],
"text": [
"walls"
]
} |
56fa19cc8f12f319006300cc | Wood | Wood is a heterogeneous, hygroscopic, cellular and anisotropic material. It consists of cells, and the cell walls are composed of micro-fibrils of cellulose (40% – 50%) and hemicellulose (15% – 25%) impregnated with lignin (15% – 30%). | What makes up 40-50% of the cell walls in wood? | {
"answer_start": [
147
],
"text": [
"cellulose"
]
} |
56fa19cc8f12f319006300cd | Wood | Wood is a heterogeneous, hygroscopic, cellular and anisotropic material. It consists of cells, and the cell walls are composed of micro-fibrils of cellulose (40% – 50%) and hemicellulose (15% – 25%) impregnated with lignin (15% – 30%). | What substance is hemicellulose impregnated with? | {
"answer_start": [
216
],
"text": [
"lignin"
]
} |
56fa1c3d8f12f319006300d3 | Wood | In coniferous or softwood species the wood cells are mostly of one kind, tracheids, and as a result the material is much more uniform in structure than that of most hardwoods. There are no vessels ("pores") in coniferous wood such as one sees so prominently in oak and ash, for example. | What type of cells makes up most wood cells in coniferous trees? | {
"answer_start": [
73
],
"text": [
"tracheids"
]
} |
56fa1c3d8f12f319006300d4 | Wood | In coniferous or softwood species the wood cells are mostly of one kind, tracheids, and as a result the material is much more uniform in structure than that of most hardwoods. There are no vessels ("pores") in coniferous wood such as one sees so prominently in oak and ash, for example. | Are hardwood or softwood species more uniform in structure? | {
"answer_start": [
17
],
"text": [
"softwood"
]
} |
56fa1c3d8f12f319006300d5 | Wood | In coniferous or softwood species the wood cells are mostly of one kind, tracheids, and as a result the material is much more uniform in structure than that of most hardwoods. There are no vessels ("pores") in coniferous wood such as one sees so prominently in oak and ash, for example. | What are the visible vessels in hardwoods commonly called? | {
"answer_start": [
199
],
"text": [
"pores"
]
} |
56fa1c3d8f12f319006300d6 | Wood | In coniferous or softwood species the wood cells are mostly of one kind, tracheids, and as a result the material is much more uniform in structure than that of most hardwoods. There are no vessels ("pores") in coniferous wood such as one sees so prominently in oak and ash, for example. | What hardwood that starts with the letter "O" would have pores? | {
"answer_start": [
261
],
"text": [
"oak"
]
} |
56fa1c3d8f12f319006300d7 | Wood | In coniferous or softwood species the wood cells are mostly of one kind, tracheids, and as a result the material is much more uniform in structure than that of most hardwoods. There are no vessels ("pores") in coniferous wood such as one sees so prominently in oak and ash, for example. | Besides oak, what's an example of a hardwood with prominent pores? | {
"answer_start": [
269
],
"text": [
"ash"
]
} |
56fa1d25f34c681400b0bfb3 | Wood | The structure of hardwoods is more complex. The water conducting capability is mostly taken care of by vessels: in some cases (oak, chestnut, ash) these are quite large and distinct, in others (buckeye, poplar, willow) too small to be seen without a hand lens. In discussing such woods it is customary to divide them into two large classes, ring-porous and diffuse-porous. | Is the structure of hardwood simple or complex? | {
"answer_start": [
35
],
"text": [
"complex"
]
} |
56fa1d25f34c681400b0bfb4 | Wood | The structure of hardwoods is more complex. The water conducting capability is mostly taken care of by vessels: in some cases (oak, chestnut, ash) these are quite large and distinct, in others (buckeye, poplar, willow) too small to be seen without a hand lens. In discussing such woods it is customary to divide them into two large classes, ring-porous and diffuse-porous. | What handles most of the water conduction in hardwoods? | {
"answer_start": [
103
],
"text": [
"vessels"
]
} |
56fa1d25f34c681400b0bfb5 | Wood | The structure of hardwoods is more complex. The water conducting capability is mostly taken care of by vessels: in some cases (oak, chestnut, ash) these are quite large and distinct, in others (buckeye, poplar, willow) too small to be seen without a hand lens. In discussing such woods it is customary to divide them into two large classes, ring-porous and diffuse-porous. | Are the vessels in chestnut wood large or small? | {
"answer_start": [
163
],
"text": [
"large"
]
} |
56fa1d25f34c681400b0bfb6 | Wood | The structure of hardwoods is more complex. The water conducting capability is mostly taken care of by vessels: in some cases (oak, chestnut, ash) these are quite large and distinct, in others (buckeye, poplar, willow) too small to be seen without a hand lens. In discussing such woods it is customary to divide them into two large classes, ring-porous and diffuse-porous. | In wood from a willow tree, what would you need to use to see the tiny vessels? | {
"answer_start": [
248
],
"text": [
"a hand lens"
]
} |
56fa1d25f34c681400b0bfb7 | Wood | The structure of hardwoods is more complex. The water conducting capability is mostly taken care of by vessels: in some cases (oak, chestnut, ash) these are quite large and distinct, in others (buckeye, poplar, willow) too small to be seen without a hand lens. In discussing such woods it is customary to divide them into two large classes, ring-porous and diffuse-porous. | Besides ring-porous, what's the other class hardwoods are often divided into? | {
"answer_start": [
357
],
"text": [
"diffuse-porous"
]
} |
56fa1ee4f34c681400b0bfbd | Wood | In ring-porous species, such as ash, black locust, catalpa, chestnut, elm, hickory, mulberry, and oak, the larger vessels or pores (as cross sections of vessels are called) are localised in the part of the growth ring formed in spring, thus forming a region of more or less open and porous tissue. The rest of the ring, produced in summer, is made up of smaller vessels and a much greater proportion of wood fibers. These fibers are the elements which give strength and toughness to wood, while the vessels are a source of weakness.[citation needed] | What species of hardwood are hickory and mulberry trees? | {
"answer_start": [
3
],
"text": [
"ring-porous"
]
} |
56fa1ee4f34c681400b0bfbe | Wood | In ring-porous species, such as ash, black locust, catalpa, chestnut, elm, hickory, mulberry, and oak, the larger vessels or pores (as cross sections of vessels are called) are localised in the part of the growth ring formed in spring, thus forming a region of more or less open and porous tissue. The rest of the ring, produced in summer, is made up of smaller vessels and a much greater proportion of wood fibers. These fibers are the elements which give strength and toughness to wood, while the vessels are a source of weakness.[citation needed] | In what season do the growth-rings of ring-porous species form with larger vessels localized? | {
"answer_start": [
228
],
"text": [
"spring"
]
} |
56fa1ee4f34c681400b0bfbf | Wood | In ring-porous species, such as ash, black locust, catalpa, chestnut, elm, hickory, mulberry, and oak, the larger vessels or pores (as cross sections of vessels are called) are localised in the part of the growth ring formed in spring, thus forming a region of more or less open and porous tissue. The rest of the ring, produced in summer, is made up of smaller vessels and a much greater proportion of wood fibers. These fibers are the elements which give strength and toughness to wood, while the vessels are a source of weakness.[citation needed] | In what season does the part of the growth-ring with smaller vessels form in ring-porous species? | {
"answer_start": [
332
],
"text": [
"summer"
]
} |
56fa1ee4f34c681400b0bfc0 | Wood | In ring-porous species, such as ash, black locust, catalpa, chestnut, elm, hickory, mulberry, and oak, the larger vessels or pores (as cross sections of vessels are called) are localised in the part of the growth ring formed in spring, thus forming a region of more or less open and porous tissue. The rest of the ring, produced in summer, is made up of smaller vessels and a much greater proportion of wood fibers. These fibers are the elements which give strength and toughness to wood, while the vessels are a source of weakness.[citation needed] | What fibers does the summer's section of growth-ring have more of? | {
"answer_start": [
403
],
"text": [
"wood fibers"
]
} |
56fa1ee4f34c681400b0bfc1 | Wood | In ring-porous species, such as ash, black locust, catalpa, chestnut, elm, hickory, mulberry, and oak, the larger vessels or pores (as cross sections of vessels are called) are localised in the part of the growth ring formed in spring, thus forming a region of more or less open and porous tissue. The rest of the ring, produced in summer, is made up of smaller vessels and a much greater proportion of wood fibers. These fibers are the elements which give strength and toughness to wood, while the vessels are a source of weakness.[citation needed] | Along with strength, what property do wood fibers lend to wood? | {
"answer_start": [
470
],
"text": [
"toughness"
]
} |
56fa2008f34c681400b0bfc7 | Wood | In diffuse-porous woods the pores are evenly sized so that the water conducting capability is scattered throughout the growth ring instead of being collected in a band or row. Examples of this kind of wood are alder, basswood,[citation needed] birch, buckeye, maple, willow,and the Populus species such as aspen, cottonwood and poplar. Some species, such as walnut and cherry, are on the border between the two classes, forming an intermediate group.[citation needed] | What kind of woods have pores that are uniformly sized? | {
"answer_start": [
3
],
"text": [
"diffuse-porous"
]
} |
56fa2008f34c681400b0bfc8 | Wood | In diffuse-porous woods the pores are evenly sized so that the water conducting capability is scattered throughout the growth ring instead of being collected in a band or row. Examples of this kind of wood are alder, basswood,[citation needed] birch, buckeye, maple, willow,and the Populus species such as aspen, cottonwood and poplar. Some species, such as walnut and cherry, are on the border between the two classes, forming an intermediate group.[citation needed] | What species do aspen, cottonwood, and poplar trees belong to? | {
"answer_start": [
282
],
"text": [
"Populus"
]
} |
56fa2008f34c681400b0bfc9 | Wood | In diffuse-porous woods the pores are evenly sized so that the water conducting capability is scattered throughout the growth ring instead of being collected in a band or row. Examples of this kind of wood are alder, basswood,[citation needed] birch, buckeye, maple, willow,and the Populus species such as aspen, cottonwood and poplar. Some species, such as walnut and cherry, are on the border between the two classes, forming an intermediate group.[citation needed] | With walnut, what's another tree in the intermediate group? | {
"answer_start": [
369
],
"text": [
"cherry"
]
} |
56fa2008f34c681400b0bfca | Wood | In diffuse-porous woods the pores are evenly sized so that the water conducting capability is scattered throughout the growth ring instead of being collected in a band or row. Examples of this kind of wood are alder, basswood,[citation needed] birch, buckeye, maple, willow,and the Populus species such as aspen, cottonwood and poplar. Some species, such as walnut and cherry, are on the border between the two classes, forming an intermediate group.[citation needed] | What capability is spread through the growth ring in ring-porous species? | {
"answer_start": [
63
],
"text": [
"water conducting"
]
} |
56fa2008f34c681400b0bfcb | Wood | In diffuse-porous woods the pores are evenly sized so that the water conducting capability is scattered throughout the growth ring instead of being collected in a band or row. Examples of this kind of wood are alder, basswood,[citation needed] birch, buckeye, maple, willow,and the Populus species such as aspen, cottonwood and poplar. Some species, such as walnut and cherry, are on the border between the two classes, forming an intermediate group.[citation needed] | Is maple wood diffuse-porous or ring-porous? | {
"answer_start": [
3
],
"text": [
"diffuse-porous"
]
} |
56fa21cdf34c681400b0bfd1 | Wood | In temperate softwoods there often is a marked difference between latewood and earlywood. The latewood will be denser than that formed early in the season. When examined under a microscope the cells of dense latewood are seen to be very thick-walled and with very small cell cavities, while those formed first in the season have thin walls and large cell cavities. The strength is in the walls, not the cavities. Hence the greater the proportion of latewood the greater the density and strength. In choosing a piece of pine where strength or stiffness is the important consideration, the principal thing to observe is the comparative amounts of earlywood and latewood. The width of ring is not nearly so important as the proportion and nature of the latewood in the ring. | What kind of softwoods often have significant differences in their earlywood and latewood? | {
"answer_start": [
3
],
"text": [
"temperate"
]
} |
56fa21cdf34c681400b0bfd2 | Wood | In temperate softwoods there often is a marked difference between latewood and earlywood. The latewood will be denser than that formed early in the season. When examined under a microscope the cells of dense latewood are seen to be very thick-walled and with very small cell cavities, while those formed first in the season have thin walls and large cell cavities. The strength is in the walls, not the cavities. Hence the greater the proportion of latewood the greater the density and strength. In choosing a piece of pine where strength or stiffness is the important consideration, the principal thing to observe is the comparative amounts of earlywood and latewood. The width of ring is not nearly so important as the proportion and nature of the latewood in the ring. | Is latewood denser or less dense than earlywood? | {
"answer_start": [
111
],
"text": [
"denser"
]
} |
56fa21cdf34c681400b0bfd3 | Wood | In temperate softwoods there often is a marked difference between latewood and earlywood. The latewood will be denser than that formed early in the season. When examined under a microscope the cells of dense latewood are seen to be very thick-walled and with very small cell cavities, while those formed first in the season have thin walls and large cell cavities. The strength is in the walls, not the cavities. Hence the greater the proportion of latewood the greater the density and strength. In choosing a piece of pine where strength or stiffness is the important consideration, the principal thing to observe is the comparative amounts of earlywood and latewood. The width of ring is not nearly so important as the proportion and nature of the latewood in the ring. | Does strength come from the walls or cavities of wood cells? | {
"answer_start": [
388
],
"text": [
"walls"
]
} |
56fa21cdf34c681400b0bfd4 | Wood | In temperate softwoods there often is a marked difference between latewood and earlywood. The latewood will be denser than that formed early in the season. When examined under a microscope the cells of dense latewood are seen to be very thick-walled and with very small cell cavities, while those formed first in the season have thin walls and large cell cavities. The strength is in the walls, not the cavities. Hence the greater the proportion of latewood the greater the density and strength. In choosing a piece of pine where strength or stiffness is the important consideration, the principal thing to observe is the comparative amounts of earlywood and latewood. The width of ring is not nearly so important as the proportion and nature of the latewood in the ring. | Are the cell walls of earlywood thick or thin? | {
"answer_start": [
329
],
"text": [
"thin"
]
} |
56fa21cdf34c681400b0bfd5 | Wood | In temperate softwoods there often is a marked difference between latewood and earlywood. The latewood will be denser than that formed early in the season. When examined under a microscope the cells of dense latewood are seen to be very thick-walled and with very small cell cavities, while those formed first in the season have thin walls and large cell cavities. The strength is in the walls, not the cavities. Hence the greater the proportion of latewood the greater the density and strength. In choosing a piece of pine where strength or stiffness is the important consideration, the principal thing to observe is the comparative amounts of earlywood and latewood. The width of ring is not nearly so important as the proportion and nature of the latewood in the ring. | What general size are the cavities in the cells of very dense latewood? | {
"answer_start": [
259
],
"text": [
"very small"
]
} |
56fa236c8f12f319006300dd | Wood | If a heavy piece of pine is compared with a lightweight piece it will be seen at once that the heavier one contains a larger proportion of latewood than the other, and is therefore showing more clearly demarcated growth rings. In white pines there is not much contrast between the different parts of the ring, and as a result the wood is very uniform in texture and is easy to work. In hard pines, on the other hand, the latewood is very dense and is deep-colored, presenting a very decided contrast to the soft, straw-colored earlywood. | Comparing a heavy and a lightweight piece of wood from a pine, which would have a greater proportion of latewood? | {
"answer_start": [
5
],
"text": [
"heavy"
]
} |
56fa236c8f12f319006300de | Wood | If a heavy piece of pine is compared with a lightweight piece it will be seen at once that the heavier one contains a larger proportion of latewood than the other, and is therefore showing more clearly demarcated growth rings. In white pines there is not much contrast between the different parts of the ring, and as a result the wood is very uniform in texture and is easy to work. In hard pines, on the other hand, the latewood is very dense and is deep-colored, presenting a very decided contrast to the soft, straw-colored earlywood. | What feature of a piece of pine with more latewood would be more clear and pronounced? | {
"answer_start": [
213
],
"text": [
"growth rings"
]
} |
56fa236c8f12f319006300df | Wood | If a heavy piece of pine is compared with a lightweight piece it will be seen at once that the heavier one contains a larger proportion of latewood than the other, and is therefore showing more clearly demarcated growth rings. In white pines there is not much contrast between the different parts of the ring, and as a result the wood is very uniform in texture and is easy to work. In hard pines, on the other hand, the latewood is very dense and is deep-colored, presenting a very decided contrast to the soft, straw-colored earlywood. | What type of tree has very little contrast between parts of its growth rings? | {
"answer_start": [
230
],
"text": [
"white pines"
]
} |
56fa236c8f12f319006300e0 | Wood | If a heavy piece of pine is compared with a lightweight piece it will be seen at once that the heavier one contains a larger proportion of latewood than the other, and is therefore showing more clearly demarcated growth rings. In white pines there is not much contrast between the different parts of the ring, and as a result the wood is very uniform in texture and is easy to work. In hard pines, on the other hand, the latewood is very dense and is deep-colored, presenting a very decided contrast to the soft, straw-colored earlywood. | Is white pine easy or difficult to work with because of its texture? | {
"answer_start": [
369
],
"text": [
"easy"
]
} |
56fa236c8f12f319006300e1 | Wood | If a heavy piece of pine is compared with a lightweight piece it will be seen at once that the heavier one contains a larger proportion of latewood than the other, and is therefore showing more clearly demarcated growth rings. In white pines there is not much contrast between the different parts of the ring, and as a result the wood is very uniform in texture and is easy to work. In hard pines, on the other hand, the latewood is very dense and is deep-colored, presenting a very decided contrast to the soft, straw-colored earlywood. | What kind of pines have very deep, darkly colored hardwood that stands out against the light earlywood? | {
"answer_start": [
386
],
"text": [
"hard pines"
]
} |
56fa254bf34c681400b0bfdb | Wood | It is not only the proportion of latewood, but also its quality, that counts. In specimens that show a very large proportion of latewood it may be noticeably more porous and weigh considerably less than the latewood in pieces that contain but little. One can judge comparative density, and therefore to some extent strength, by visual inspection. | Having a high proportion of latewood isn't all that matters; what else is important? | {
"answer_start": [
56
],
"text": [
"quality"
]
} |
56fa254bf34c681400b0bfdc | Wood | It is not only the proportion of latewood, but also its quality, that counts. In specimens that show a very large proportion of latewood it may be noticeably more porous and weigh considerably less than the latewood in pieces that contain but little. One can judge comparative density, and therefore to some extent strength, by visual inspection. | What can we judge in wood just by looking at it? | {
"answer_start": [
265
],
"text": [
"comparative density"
]
} |
56fa254bf34c681400b0bfdd | Wood | It is not only the proportion of latewood, but also its quality, that counts. In specimens that show a very large proportion of latewood it may be noticeably more porous and weigh considerably less than the latewood in pieces that contain but little. One can judge comparative density, and therefore to some extent strength, by visual inspection. | What property of wood could we project some indication of by looking at its density? | {
"answer_start": [
315
],
"text": [
"strength"
]
} |
56fa254bf34c681400b0bfde | Wood | It is not only the proportion of latewood, but also its quality, that counts. In specimens that show a very large proportion of latewood it may be noticeably more porous and weigh considerably less than the latewood in pieces that contain but little. One can judge comparative density, and therefore to some extent strength, by visual inspection. | What could we call some specimens with a high proportion of latewood that explains why they weigh less than specimens with much less latewood? | {
"answer_start": [
163
],
"text": [
"porous"
]
} |
56fa29d8f34c681400b0bfe3 | Wood | No satisfactory explanation can as yet be given for the exact mechanisms determining the formation of earlywood and latewood. Several factors may be involved. In conifers, at least, rate of growth alone does not determine the proportion of the two portions of the ring, for in some cases the wood of slow growth is very hard and heavy, while in others the opposite is true. The quality of the site where the tree grows undoubtedly affects the character of the wood formed, though it is not possible to formulate a rule governing it. In general, however, it may be said that where strength or ease of working is essential, woods of moderate to slow growth should be chosen. | What facet of wood is affected to some degree by the place where the tree grows? | {
"answer_start": [
443
],
"text": [
"character"
]
} |
56fa29d8f34c681400b0bfe4 | Wood | No satisfactory explanation can as yet be given for the exact mechanisms determining the formation of earlywood and latewood. Several factors may be involved. In conifers, at least, rate of growth alone does not determine the proportion of the two portions of the ring, for in some cases the wood of slow growth is very hard and heavy, while in others the opposite is true. The quality of the site where the tree grows undoubtedly affects the character of the wood formed, though it is not possible to formulate a rule governing it. In general, however, it may be said that where strength or ease of working is essential, woods of moderate to slow growth should be chosen. | If you want wood that's easy to work with, what kind of growth would you want the tree to have? | {
"answer_start": [
631
],
"text": [
"moderate to slow"
]
} |
56fa29d8f34c681400b0bfe5 | Wood | No satisfactory explanation can as yet be given for the exact mechanisms determining the formation of earlywood and latewood. Several factors may be involved. In conifers, at least, rate of growth alone does not determine the proportion of the two portions of the ring, for in some cases the wood of slow growth is very hard and heavy, while in others the opposite is true. The quality of the site where the tree grows undoubtedly affects the character of the wood formed, though it is not possible to formulate a rule governing it. In general, however, it may be said that where strength or ease of working is essential, woods of moderate to slow growth should be chosen. | What species of tree can be said to growth ring proportions that aren't determined just by their rate of growth? | {
"answer_start": [
162
],
"text": [
"conifers"
]
} |
56fa29d8f34c681400b0bfe6 | Wood | No satisfactory explanation can as yet be given for the exact mechanisms determining the formation of earlywood and latewood. Several factors may be involved. In conifers, at least, rate of growth alone does not determine the proportion of the two portions of the ring, for in some cases the wood of slow growth is very hard and heavy, while in others the opposite is true. The quality of the site where the tree grows undoubtedly affects the character of the wood formed, though it is not possible to formulate a rule governing it. In general, however, it may be said that where strength or ease of working is essential, woods of moderate to slow growth should be chosen. | What counterpart of earlywood are scientists still trying to explain the formation of? | {
"answer_start": [
116
],
"text": [
"latewood"
]
} |
56fa29d8f34c681400b0bfe7 | Wood | No satisfactory explanation can as yet be given for the exact mechanisms determining the formation of earlywood and latewood. Several factors may be involved. In conifers, at least, rate of growth alone does not determine the proportion of the two portions of the ring, for in some cases the wood of slow growth is very hard and heavy, while in others the opposite is true. The quality of the site where the tree grows undoubtedly affects the character of the wood formed, though it is not possible to formulate a rule governing it. In general, however, it may be said that where strength or ease of working is essential, woods of moderate to slow growth should be chosen. | While there is some relationship between where and how a tree grows, what can't anyone formulate to govern it? | {
"answer_start": [
512
],
"text": [
"a rule"
]
} |
56fa2ab88f12f319006300e7 | Wood | In ring-porous woods each season's growth is always well defined, because the large pores formed early in the season abut on the denser tissue of the year before. | What kind of woods always have very clearly marked seasonal growth? | {
"answer_start": [
3
],
"text": [
"ring-porous"
]
} |
56fa2ab88f12f319006300e8 | Wood | In ring-porous woods each season's growth is always well defined, because the large pores formed early in the season abut on the denser tissue of the year before. | What size pores form early in ring-porous woods' growing season? | {
"answer_start": [
78
],
"text": [
"large"
]
} |
56fa2ab88f12f319006300e9 | Wood | In ring-porous woods each season's growth is always well defined, because the large pores formed early in the season abut on the denser tissue of the year before. | When does the denser tissue the new pores abut come from? | {
"answer_start": [
146
],
"text": [
"the year before"
]
} |
56fa2d76f34c681400b0bfed | Wood | In the case of the ring-porous hardwoods there seems to exist a pretty definite relation between the rate of growth of timber and its properties. This may be briefly summed up in the general statement that the more rapid the growth or the wider the rings of growth, the heavier, harder, stronger, and stiffer the wood. This, it must be remembered, applies only to ring-porous woods such as oak, ash, hickory, and others of the same group, and is, of course, subject to some exceptions and limitations. | Ring-porous hardwoods have a clear relationship between their properties and what other factor? | {
"answer_start": [
101
],
"text": [
"rate of growth"
]
} |
56fa2d76f34c681400b0bfee | Wood | In the case of the ring-porous hardwoods there seems to exist a pretty definite relation between the rate of growth of timber and its properties. This may be briefly summed up in the general statement that the more rapid the growth or the wider the rings of growth, the heavier, harder, stronger, and stiffer the wood. This, it must be remembered, applies only to ring-porous woods such as oak, ash, hickory, and others of the same group, and is, of course, subject to some exceptions and limitations. | Is harder, heavier wood indicated by narrower or wider growth rings? | {
"answer_start": [
239
],
"text": [
"wider"
]
} |
56fa2d76f34c681400b0bfef | Wood | In the case of the ring-porous hardwoods there seems to exist a pretty definite relation between the rate of growth of timber and its properties. This may be briefly summed up in the general statement that the more rapid the growth or the wider the rings of growth, the heavier, harder, stronger, and stiffer the wood. This, it must be remembered, applies only to ring-porous woods such as oak, ash, hickory, and others of the same group, and is, of course, subject to some exceptions and limitations. | What kind of wood with a name that starts with "H" is a ring-porous hardwood? | {
"answer_start": [
400
],
"text": [
"hickory"
]
} |
56fa2d76f34c681400b0bff0 | Wood | In the case of the ring-porous hardwoods there seems to exist a pretty definite relation between the rate of growth of timber and its properties. This may be briefly summed up in the general statement that the more rapid the growth or the wider the rings of growth, the heavier, harder, stronger, and stiffer the wood. This, it must be remembered, applies only to ring-porous woods such as oak, ash, hickory, and others of the same group, and is, of course, subject to some exceptions and limitations. | If the growth rings are wider, was the growth of the tree slower or more rapid? | {
"answer_start": [
210
],
"text": [
"more rapid"
]
} |
56fa2d76f34c681400b0bff1 | Wood | In the case of the ring-porous hardwoods there seems to exist a pretty definite relation between the rate of growth of timber and its properties. This may be briefly summed up in the general statement that the more rapid the growth or the wider the rings of growth, the heavier, harder, stronger, and stiffer the wood. This, it must be remembered, applies only to ring-porous woods such as oak, ash, hickory, and others of the same group, and is, of course, subject to some exceptions and limitations. | What is the only kind of wood that will definitely be harder and stronger when it grows faster? | {
"answer_start": [
364
],
"text": [
"ring-porous"
]
} |
56fa3006f34c681400b0bff7 | Wood | In ring-porous woods of good growth it is usually the latewood in which the thick-walled, strength-giving fibers are most abundant. As the breadth of ring diminishes, this latewood is reduced so that very slow growth produces comparatively light, porous wood composed of thin-walled vessels and wood parenchyma. In good oak these large vessels of the earlywood occupy from 6 to 10 percent of the volume of the log, while in inferior material they may make up 25% or more. The latewood of good oak is dark colored and firm, and consists mostly of thick-walled fibers which form one-half or more of the wood. In inferior oak, this latewood is much reduced both in quantity and quality. Such variation is very largely the result of rate of growth. | Which specific type of wood within ring-porous woods have more fibers to make it strong? | {
"answer_start": [
54
],
"text": [
"latewood"
]
} |
56fa3006f34c681400b0bff8 | Wood | In ring-porous woods of good growth it is usually the latewood in which the thick-walled, strength-giving fibers are most abundant. As the breadth of ring diminishes, this latewood is reduced so that very slow growth produces comparatively light, porous wood composed of thin-walled vessels and wood parenchyma. In good oak these large vessels of the earlywood occupy from 6 to 10 percent of the volume of the log, while in inferior material they may make up 25% or more. The latewood of good oak is dark colored and firm, and consists mostly of thick-walled fibers which form one-half or more of the wood. In inferior oak, this latewood is much reduced both in quantity and quality. Such variation is very largely the result of rate of growth. | When there is less latewood, what is diminishing? | {
"answer_start": [
139
],
"text": [
"breadth of ring"
]
} |
56fa3006f34c681400b0bff9 | Wood | In ring-porous woods of good growth it is usually the latewood in which the thick-walled, strength-giving fibers are most abundant. As the breadth of ring diminishes, this latewood is reduced so that very slow growth produces comparatively light, porous wood composed of thin-walled vessels and wood parenchyma. In good oak these large vessels of the earlywood occupy from 6 to 10 percent of the volume of the log, while in inferior material they may make up 25% or more. The latewood of good oak is dark colored and firm, and consists mostly of thick-walled fibers which form one-half or more of the wood. In inferior oak, this latewood is much reduced both in quantity and quality. Such variation is very largely the result of rate of growth. | Does slow or rapid growth make relatively porous, light wood? | {
"answer_start": [
205
],
"text": [
"slow"
]
} |
56fa3006f34c681400b0bffa | Wood | In ring-porous woods of good growth it is usually the latewood in which the thick-walled, strength-giving fibers are most abundant. As the breadth of ring diminishes, this latewood is reduced so that very slow growth produces comparatively light, porous wood composed of thin-walled vessels and wood parenchyma. In good oak these large vessels of the earlywood occupy from 6 to 10 percent of the volume of the log, while in inferior material they may make up 25% or more. The latewood of good oak is dark colored and firm, and consists mostly of thick-walled fibers which form one-half or more of the wood. In inferior oak, this latewood is much reduced both in quantity and quality. Such variation is very largely the result of rate of growth. | What kind of oak has just 6-10% volume of large vessels in the log? | {
"answer_start": [
315
],
"text": [
"good"
]
} |
56fa3006f34c681400b0bffb | Wood | In ring-porous woods of good growth it is usually the latewood in which the thick-walled, strength-giving fibers are most abundant. As the breadth of ring diminishes, this latewood is reduced so that very slow growth produces comparatively light, porous wood composed of thin-walled vessels and wood parenchyma. In good oak these large vessels of the earlywood occupy from 6 to 10 percent of the volume of the log, while in inferior material they may make up 25% or more. The latewood of good oak is dark colored and firm, and consists mostly of thick-walled fibers which form one-half or more of the wood. In inferior oak, this latewood is much reduced both in quantity and quality. Such variation is very largely the result of rate of growth. | What kind of fibers are in the latewood of good oak, making it very firm? | {
"answer_start": [
546
],
"text": [
"thick-walled"
]
} |
56fa317bf34c681400b0c001 | Wood | Wide-ringed wood is often called "second-growth", because the growth of the young timber in open stands after the old trees have been removed is more rapid than in trees in a closed forest, and in the manufacture of articles where strength is an important consideration such "second-growth" hardwood material is preferred. This is particularly the case in the choice of hickory for handles and spokes. Here not only strength, but toughness and resilience are important. The results of a series of tests on hickory by the U.S. Forest Service show that: | What term is sometimes used for wood with wide rings? | {
"answer_start": [
34
],
"text": [
"second-growth"
]
} |
56fa317bf34c681400b0c002 | Wood | Wide-ringed wood is often called "second-growth", because the growth of the young timber in open stands after the old trees have been removed is more rapid than in trees in a closed forest, and in the manufacture of articles where strength is an important consideration such "second-growth" hardwood material is preferred. This is particularly the case in the choice of hickory for handles and spokes. Here not only strength, but toughness and resilience are important. The results of a series of tests on hickory by the U.S. Forest Service show that: | Do young trees grow more quickly in open stands or in a closed forest? | {
"answer_start": [
92
],
"text": [
"open stands"
]
} |
56fa317bf34c681400b0c003 | Wood | Wide-ringed wood is often called "second-growth", because the growth of the young timber in open stands after the old trees have been removed is more rapid than in trees in a closed forest, and in the manufacture of articles where strength is an important consideration such "second-growth" hardwood material is preferred. This is particularly the case in the choice of hickory for handles and spokes. Here not only strength, but toughness and resilience are important. The results of a series of tests on hickory by the U.S. Forest Service show that: | What property is important to manufacturers who use "second-growth" hardwood? | {
"answer_start": [
231
],
"text": [
"strength"
]
} |
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