降り積もった雪は音を吸収することが知られている。雪は、顕微鏡で覗くときれいな結晶になっていて、雪と雪の間にある小さなすき間に音が吸収されると考えられている。条件によっては80％以上の音を吸収することさえある。新雪は特に音波の吸収特性が優れているため、降雪後数時間は人間の耳にも知覚できるほど周囲の音が違って聞こえる。ところが、昼夜の温度変化により雪が溶けたり固まったりしながらだんだん硬くなると、隙間が埋まって吸音特性が失われる。雪の驚くべき吸音効果は、単に結晶の隙間に空気があるためばかりでなく、雪の結晶の神秘的な形にも秘密があるのかもしれない。
私たちの身の回りの電気製品や自動車などには、騒音や振動を抑えるための様々な工夫がされているが、雪の結晶が80%もの音を吸収する仕組みは将来こうしたところに利用できるヒントが隠されているかもしれない。
| Query | Error | Affected | Num. rows | Took (ms) | Actions |
|---|---|---|---|---|---|
| SHOW FULL COLUMNS FROM `contents` | 16 | 16 | 2 | maybe slow | |
| SELECT CHARACTER_SET_NAME FROM INFORMATION_SCHEMA.COLLATIONS WHERE COLLATION_NAME= 'utf8_general_ci'; | 1 | 1 | 1 | ||
| SHOW FULL COLUMNS FROM `users` | 10 | 10 | 1 | maybe slow | |
| SHOW FULL COLUMNS FROM `groups` | 4 | 4 | 1 | maybe slow | |
| SHOW FULL COLUMNS FROM `permissions` | 5 | 5 | 1 | maybe slow | |
| SHOW FULL COLUMNS FROM `groups_permissions` | 3 | 3 | 1 | maybe slow | |
| SHOW FULL COLUMNS FROM `groups_users` | 3 | 3 | 1 | maybe slow | |
| SHOW FULL COLUMNS FROM `contents_searches` | 6 | 6 | 1 | maybe slow | |
| SHOW FULL COLUMNS FROM `attachments` | 11 | 11 | 1 | maybe slow | |
| SHOW FULL COLUMNS FROM `attachments_revs` | 13 | 13 | 1 | maybe slow | |
| SHOW FULL COLUMNS FROM `contents_related_items` | 5 | 5 | 1 | maybe slow | |
| SHOW FULL COLUMNS FROM `related_items` | 6 | 6 | 1 | maybe slow | |
| SHOW FULL COLUMNS FROM `contents_related_items_revs` | 8 | 8 | 1 | maybe slow | |
| SHOW FULL COLUMNS FROM `contents_tags` | 5 | 5 | 1 | maybe slow | |
| SHOW FULL COLUMNS FROM `tags` | 7 | 7 | 1 | maybe slow | |
| SHOW FULL COLUMNS FROM `tag_groups` | 6 | 6 | 1 | maybe slow | |
| SHOW FULL COLUMNS FROM `contents_tags_revs` | 7 | 7 | 1 | maybe slow | |
| SHOW FULL COLUMNS FROM `contents_revs` | 18 | 18 | 2 | maybe slow | |
| SELECT `Content`.`id`, `Content`.`user_id`, `Content`.`last_edit_user_id`, `Content`.`post_date`, `Content`.`post_date_year`, `Content`.`post_date_month`, `Content`.`post_date_day`, `Content`.`title`, `Content`.`title_en`, `Content`.`content`, `Content`.`plain_content`, `Content`.`page_view`, `Content`.`flag`, `Content`.`mod_count`, `Content`.`created`, `Content`.`modified` FROM `contents` AS `Content` WHERE `id` = 199 LIMIT 1 | 1 | 1 | 0 | ||
| SELECT `Attachment`.`file_name`, `Attachment`.`dir`, `Attachment`.`model`, `Attachment`.`foreign_key` FROM `attachments` AS `Attachment` WHERE `file_name` <> 'default.jpg' AND `Attachment`.`foreign_key` = (199) | 1 | 1 | 0 | ||
| SELECT `ContentsRelatedItem`.`content`, `ContentsRelatedItem`.`related_item_id`, `ContentsRelatedItem`.`content_id` FROM `contents_related_items` AS `ContentsRelatedItem` WHERE `ContentsRelatedItem`.`content_id` = (199) | 10 | 10 | 0 | ||
| SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 1 | 1 | 1 | 0 | ||
| SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 2 | 1 | 1 | 0 | ||
| SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 4 | 1 | 1 | 0 | ||
| SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 6 | 1 | 1 | 0 | ||
| SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 7 | 1 | 1 | 0 | ||
| SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 8 | 1 | 1 | 0 | ||
| SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 9 | 1 | 1 | 0 | ||
| SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 9 | 1 | 1 | 0 | ||
| SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 9 | 1 | 1 | 0 | ||
| SELECT `RelatedItem`.`code`, `RelatedItem`.`name` FROM `related_items` AS `RelatedItem` WHERE `RelatedItem`.`id` = 11 | 1 | 1 | 0 | ||
| SELECT `ContentsTag`.`id`, `ContentsTag`.`tag_group_id`, `ContentsTag`.`mod_count`, `ContentsTag`.`tag_id`, `ContentsTag`.`content_id` FROM `contents_tags` AS `ContentsTag` WHERE `ContentsTag`.`content_id` = (199) | 2 | 2 | 0 | ||
| SELECT `Tag`.`name`, `Tag`.`comment`, `Tag`.`tag_group_id` FROM `tags` AS `Tag` WHERE `Tag`.`id` = 12 | 1 | 1 | 0 | ||
| SELECT `TagGroup`.`code`, `TagGroup`.`name` FROM `tag_groups` AS `TagGroup` WHERE `TagGroup`.`id` = 1 | 1 | 1 | 0 | ||
| SELECT `Tag`.`name`, `Tag`.`comment`, `Tag`.`tag_group_id` FROM `tags` AS `Tag` WHERE `Tag`.`id` = 175 | 1 | 1 | 0 | ||
| SELECT `TagGroup`.`code`, `TagGroup`.`name` FROM `tag_groups` AS `TagGroup` WHERE `TagGroup`.`id` = 7 | 1 | 1 | 0 | ||
| SELECT `RelatedItem`.`id`, `RelatedItem`.`code`, `RelatedItem`.`name`, `RelatedItem`.`created`, `RelatedItem`.`modified`, `RelatedItem`.`flag` FROM `related_items` AS `RelatedItem` WHERE `code` = 'function' LIMIT 1 | 1 | 1 | 0 | ||
| SELECT `Content`.`id`, `Content`.`title`, `Content`.`title_en` FROM `contents` AS `Content` WHERE id = (NULL) ORDER BY `id` desc | 0 | 0 | 0 |
Peak Memory Use 9.01 MB
| Message | Memory use |
|---|---|
| Component intitailization | 6.79 MB |
| Controller action start | 6.83 MB |
| Controller render start | 6.90 MB |
| View render complete | 7.92 MB |
Total Request Time: 764 (ms)
| Message | Time in ms | Graph |
|---|---|---|
| Core Processing (Derived) | 346.41 | |
| Component initialization and startup | 17.28 | |
| Controller action | 41.78 | |
| Render Controller Action | 64.19 | |
| » Rendering View | 52.59 | |
| » » Rendering APP/views/contents/view.ctp | 32.71 | |
| » » Rendering APP/views/layouts/default.ctp | 18.18 | |
| » » » Rendering APP/views/elements/header.ctp | 9.71 | |
| » » » Rendering APP/views/elements/content_sidebar.ctp | 0.46 | |
| » » » Rendering APP/views/elements/footer.ctp | 0.40 |
