関連する実験動画

Updated: Jul 12, 2026

Continuous Hydrologic and Water Quality Monitoring of Vernal Ponds
06:37

Continuous Hydrologic and Water Quality Monitoring of Vernal Ponds

Published on: November 13, 2017

ベネズエラ・バレンシア湖の四重期の後半の環境史

J P Bradbury, B Leyden, M Salgado-Labouriau

    Science (New York, N.Y.)
    |December 18, 1981
    PubMed
    まとめ

    バレンシア湖 (ベネズエラ) の古気候データから,1万3千年の気候の歴史が明らかになる. 初期の乾燥状態は,樹木植生のある恒久的な湖へと移行し,その後,人間の活動によって悪化した乾燥エピソードが続いた.

    さらに関連する動画

    Visualizing Methane-Cycling Microbial Dynamics in Coastal Wetlands07:26

    Visualizing Methane-Cycling Microbial Dynamics in Coastal Wetlands

    Published on: January 31, 2025

    関連する概念動画

    Quality of Water01:19

    Quality of Water

    In concrete preparation, the quality of water is paramount as it affects the strength and durability of the concrete. Potable water is usually preferred; however, it must not have excessive sodium or potassium to prevent compromising the concrete's integrity. Water quality is typically evaluated based on impurities such as dissolved solids, chlorides, and sulfates, and its pH value is ideally between 6 and 8. Even slightly acidic natural water may be acceptable unless it contains harmful...
    Freshwater Microbial Ecology01:24

    Freshwater Microbial Ecology

    Freshwater systems such as streams, rivers, and lakes exhibit distinct physical and biological characteristics that influence their microbial communities. These environments are broadly categorized into lotic systems—those with flowing waters like streams and most rivers—and lentic systems, which include still or slow-moving waters such as lakes, ponds, and marshes.In lentic systems, phytoplankton drive primary production, generating autochthonous organic carbon. In contrast, lotic systems...
    Testing Water Quality01:14

    Testing Water Quality

    When the quality of water for concrete preparation is uncertain, its impact on the setting time of cement and compressive strength of mortar is assessed by comparison with de-ionized or distilled water benchmarks. American Society for Testing and Materials (ASTM) C1602 requires the setting times to be within 90 minutes of the control, British Standard (BS) 3146:1980 allows a 30-minute variance in the initial setting, while British Standards European Norm (BS EN) 1008 specifies initial setting...
    Deep Sea Microbial Ecology01:18

    Deep Sea Microbial Ecology

    The deep ocean and its underlying sediments represent vast, largely unexplored microbial habitats that extend far beyond the sunlit photic zone. The photic (euphotic) zone typically spans the upper ~100–200 meters of pelagic waters in the open ocean, but its depth varies geographically and seasonally, where sufficient light supports photosynthetic life. Below this lies the deep sea, spanning roughly 1000–6000 meters (bathypelagic to abyssal zones), with deeper hadal trenches extending beyond...
    Acid Mine Drainage01:19

    Acid Mine Drainage

    Mining activities that disturb sulfide-rich rocks, particularly those containing pyrite (FeS₂), initiate a cascade of geochemical and microbiological processes with serious environmental implications. When exposed to air and water, pyrite undergoes oxidation, releasing sulfate, ultimately forming sulfuric acid and mobilizing heavy metals into surrounding water systems. This phenomenon, known as acid mine drainage (AMD), results in low pH waters laden with toxic elements that threaten aquatic...
    Microbial Leaching01:27

    Microbial Leaching

    Microbial leaching, also known as bioleaching, is an environmentally favorable method for extracting metals from low-grade ores using specific microorganisms. This biotechnological approach is particularly valuable for mining operations targeting copper, gold, and uranium, where traditional extraction methods may be economically or environmentally impractical.Copper Leaching and Microbial CatalysisIn copper bioleaching, crushed ore is arranged into heaps and irrigated with a dilute sulfuric...