scholarly journals Introduction to the Principles of δ18O, δ13C, and 87Sr/86Sr in the Palaeosciences.

2021 ◽  
Author(s):  
Jack Wilkin
Keyword(s):  
Stable Isotopes ◽  
Organic Carbon ◽  
Food Webs ◽  
Quantitative Data ◽  
Ecological Change ◽  
Metabolic Rates ◽  
Research Institutions ◽  
Glacial Ice ◽  
Weathering Rates ◽  
The World

The stable isotopes of oxygen (O), carbon (C), strontium (Sr), hydrogen (H), and nitrogen (N) have all been utilised for great effect in palaeoclimate, palaeoecological and palaeobiological studies. Of these, O and C have been by far the most important and, in many types of study, their use has become routine in universities and research institutions around the world. Stable isotopes provide quantitative data about palaeotemperatures, metabolic rates, food webs, palaeosalinity, palaeoprecipitation and evaporation rates as well as glacial ice volumes, production and burial of organic carbon, and other processes related to palaeoclimatic/biological/ecological change. Except for Sr, all the previously mentioned isotopes (O, C, H, and N) directly record paleoclimatic, biological and palaeoecological processes. Conversely, Sr reflects the composition of rocks at the Earth's surface, and its values reflect on the climate indirectly as it is a proxy for global weathering rates and seafloor spreading. This review will only be focusing on three isotopes commonly deployed by palaeo-researchers: carbon, oxygen, and strontium.

scholarly journals Air pollutants in Xinjiang during the COVID-19 pandemic and glaciochemical records of a Tien-Shan glacier

2021 ◽  
Author(s):  
Feiteng Wang ◽  
Xin Zhang ◽  
Fanglong Wang ◽  
Mengyuan Song ◽  
Zhongqin Li ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Organic Carbon ◽  
Tree Rings ◽  
Air Pollutants ◽  
Local Governments ◽  
Ice Cores ◽  
Tien Shan ◽  
Autonomous Region ◽  
Soluble Ions ◽  
The World

Abstract. The outbreak of COVID-19 unprecedently impacts the world in many aspects. Air pollutants have been largely reduced in cities worldwide, as reported by numerous studies. We investigated the daily concentrations of SO2, NO2, CO and PM2.5 monitored across the Xinjiang Uygur Autonomous Region (Xinjiang), China, from 2019 through 2020. The variation in NO2 showed responding dips when the local governments imposed mobility restriction measures, while SO2, CO and PM2.5 did not consistently correspond to NO2. This difference indicates that the restriction measures targeted traffic majorly. Sampling from two snow pits separately dug in 2019 and 2020 in Urumqi No.1 (UG1), we analysed water-stable isotopes, soluble ions, black and organic carbon (BC and OC). BC and OC show no differences in the snow-pit profiles dated from 2018 to 2020. The concentrations of human activity induced soluble ions (K+, Cl−, SO42− and NO3−) in the snow shrank to 20 %–30% in 2020 of their respective concentrations in 2019, while they increased 2–3.5-fold in 2019 from before 2018. We suggest that the pandemic has already left marks in the cryosphere and outlook that more evidence would be exposed in ice cores, tree rings, and other archives in the future.

The Black Sea factor influencing the wastewater disposal strategy for Istanbul

1995 ◽  
Vol 32 (7) ◽  
pp. 63-70
Author(s):  
I. Ethem Gönenç ◽  
Oguz Müftüoglu ◽  
Bilsen Beler Baykal ◽  
Ertugrul Dogan ◽  
Hüseyin Yüce ◽  
...  
Keyword(s):  
Black Sea ◽  
Satellite Images ◽  
The Black Sea ◽  
Marmara Sea ◽  
Research Institutions ◽  
Trophic Conditions ◽  
Wastewater Disposal ◽  
The World ◽  
Collaborative Efforts

Unlike other seas of the world, the Black Sea shows unique quality and trophic properties. Fortunately, only the upper layer water of the Black Sea is introduced into the Bosphorus and has a significant effect on the quality and trophic conditions of the Marmara Sea. These effects are discussed in the light of data obtained from collaborative efforts of Turkish and Romanian research institutions and processed satellite images. In conjunction with these discussions, recommendations for a suitable effluent disposal strategy for Istanbul's wastewater have been given.

Regenerative flow pumps, blowers and compressors – A review

2021 ◽  
pp. 095765092110181
Author(s):  
M Sreekanth ◽  
R Sivakumar ◽  
M Sai Santosh Pavan Kumar ◽  
K Karunamurthy ◽  
MB Shyam Kumar ◽  
...  
Keyword(s):  
Quantitative Data ◽  
Research Work ◽  
Future Research ◽  
Performance Parameters ◽  
The World ◽  
Working Principle ◽  
Computational Fluid Dynamics Cfd ◽  
Specific Speed ◽  
Regenerative Flow ◽  
Product Description

This paper presents a detailed and objective review of regenerative flow turbomachines, namely pumps, blowers and compressors. Several aspects of turbomachines like design and operating parameters, working principle, flow behaviour, performance parameters and analytical and Computational Fluid Dynamics (CFD) related details have been reviewed and summarized. Experimental work has been put in perspective and the most useful results for optimized performance have been presented. Consolidated plots of specific speed-specific diameter have been plotted which can be helpful in the early stages of design. Industrial outlook involving details of suppliers from various parts of the world, their product description and applications too are included. Finally, future research work to be carried out to make these machines widespread is suggested. This review is targeted at designer engineers who would need quantitative data to work with.

scholarly journals Ecological Change, Sliding Baselines and the Importance of Historical Data: Lessons from Combing Observational and Quantitative Data on a Temperate Reef Over 70 Years

PLoS ONE ◽  
2015 ◽  
Vol 10 (2) ◽  
pp. e0118581 ◽  
Author(s):  
Giulia Gatti ◽  
Carlo Nike Bianchi ◽  
Valeriano Parravicini ◽  
Alessio Rovere ◽  
Andrea Peirano ◽  
...  
Keyword(s):  
Quantitative Data ◽  
Historical Data ◽  
Ecological Change ◽  
Temperate Reef

scholarly journals Stable isotopes of a terrestrial amphibian illustrate fertilizer-related nitrogen enrichment of food webs in agricultural habitats

2021 ◽  
Vol 319 ◽  
pp. 107553
Author(s):  
Matthias Renoirt ◽  
Frédéric Angelier ◽  
Marion Cheron ◽  
Paco Bustamante ◽  
Yves Cherel ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Food Webs ◽  
Nitrogen Enrichment

Boomerang ecosystem fluxes: organic carbon inputs from land to lakes are returned to terrestrial food webs via aquatic insects

Oikos ◽  
2014 ◽  
Vol 123 (12) ◽  
pp. 1439-1448 ◽  
Author(s):  
K. Scharnweber ◽  
M. J. Vanni ◽  
S. Hilt ◽  
J. Syväranta ◽  
T. Mehner
Keyword(s):  
Organic Carbon ◽  
Food Webs ◽  
Aquatic Insects

Potential soil carbon sequestration of agricultural land around the world

2021 ◽  
Author(s):  
Sylvia Vetter ◽  
Michael Martin ◽  
Pete Smith
Keyword(s):  
Organic Carbon ◽  
Management Practices ◽  
Agricultural Land ◽  
Ghg Emissions ◽  
C Sequestration ◽  
Organic Soils ◽  
Soil C ◽  
Sequestration Potential ◽  
The World ◽  
Soil C Sequestration

<p>Reducing greenhouse gas (GHG) emissions in to the atmosphere to limit global warming is the big challenge of the coming decades. The focus lies on negative emission technologies to remove GHGs from the atmosphere from different sectors. Agriculture produces around a quarter of all the anthropogenic GHGs globally (including land use change and afforestation). Reducing these net emissions can be achieved through techniques that increase the soil organic carbon (SOC) stocks. These techniques include improved management practices in agriculture and grassland systems, which increase the organic carbon (C) input or reduce soil disturbances. The C sequestration potential differs among soils depending on climate, soil properties and management, with the highest potential for poor soils (SOC stock farthest from saturation).</p><p>Modelling can be used to estimate the technical potential to sequester C of agricultural land under different mitigation practices for the next decades under different climate scenarios. The ECOSSE model was developed to simulate soil C dynamics and GHG emissions in mineral and organic soils. A spatial version of the model (GlobalECOSSE) was adapted to simulate agricultural soils around the world to calculate the SOC change under changing management and climate.</p><p>Practices like different tillage management, crop rotations and residue incorporation showed regional differences and the importance of adapting mitigation practices under an increased changing climate. A fast adoption of practices that increase SOC has its own challenges, as the potential to sequester C is high until the soil reached a new C equilibrium. Therefore, the potential to use soil C sequestration to reduce overall GHG emissions is limited. The results showed a high potential to sequester C until 2050 but much lower rates in the second half of the century, highlighting the importance of using soil C sequestration in the coming decades to reach net zero by 2050.</p>

Predicting Source Water Quality Following Wildfires Using Hydrologic Modeling

2021 ◽  
Author(s):  
Katie Wampler ◽  
Kevin D. Bladon ◽  
Monireh Faramarzi
Keyword(s):  
Water Quality ◽  
Drinking Water ◽  
Organic Carbon ◽  
The United States ◽  
First Year ◽  
Model Parameters ◽  
Source Water ◽  
Forested Watersheds ◽  
Field Samples ◽  
The World

<p>Forested watersheds are critical sources of the majority of the world’s drinking water. Almost one-third of the world’s largest cities and two-thirds of cities in the United States (US) rely on forested watersheds for their water supply. These forested regions are vulnerable to the increasing incidence of large and severe wildfires due to increases in regional temperatures and greater accumulation of fuels. When wildfires occur, increases in suspended sediment and organic carbon can negatively affect aquatic ecosystem health and create many costly challenges to the drinking water treatment process. These effects are often largest in the first year following a wildfire. While past research has shown the likelihood of source water impacts from wildfire, the magnitude of effects remains uncertain in most regions. In our study, we will quantify the projected short-term effects of three large (>70,000 ha) wildfires on key water quality parameters (sediment and organic carbon) in two important forested source watersheds in the Cascade Range of Oregon, US. We calibrated and validated a modified Soil and Water Assessment Tool (SWAT) to simulate streamflow, sediment loads and transport, as well as in-stream organic carbon processes for a historical period prior to wildfire. The calibrated model parameters were then modified based on literature values and burn severity maps to represent post-fire conditions of the three large wildfires. The parameter adjustments for simulating wildfire will be validated with post-fire water quality field samples from the wildfires. We will present estimations of future water quality impacts in the burned watersheds under different precipitation conditions at a daily scale for the first year following the wildfires, which will provide testable hypotheses. Additionally, we will determine catchment characteristics most critical in determining the post-fire water quality response. This work will help predict the magnitude of effects from these historic wildfires, which can inform forest and drinking water management decision making.</p>

Environments of Empire

2020 ◽  
Keyword(s):  
Case Studies ◽  
British Empire ◽  
Invasive Plants ◽  
Historical Analysis ◽  
Unintended Consequences ◽  
Ecological Change ◽  
The World

The age of European high imperialism was characterized by the movement of plants and animals on a historically unprecedented scale. The human migrants who colonized territories around the world brought a variety of other species with them, from the crops and livestock they hoped to propagate, to the parasites, invasive plants, and pests they carried unawares, producing a host of unintended consequences that reshaped landscapes around the world. While the majority of histories about the dynamics of these transfers have concentrated on the British Empire, these nine case studies--focused on the Ottoman, French, Dutch, German, and British empires--seek to advance a historical analysis that is comparative, transnational, and interdisciplinary to understand the causes, consequences, and networks of biological exchange and ecological change resulting from imperialism.

Sign in / Sign up

Export Citation Format

Share Document