Effects of a diatom ecosystem engineer (Didymosphenia geminata) on stream food webs: implications for native fishes

2021 ◽  
Vol 78 (2) ◽  
pp. 154-164
Author(s):  
Niall G. Clancy ◽  
Janice Brahney ◽  
James Dunnigan ◽  
Phaedra Budy
Keyword(s):  
Energy Demand ◽  
Aquatic Invertebrates ◽  
Ecosystem Engineer ◽  
Benthic Algae ◽  
Stream Habitat ◽  
Didymosphenia Geminata ◽  
Native Fishes ◽  
Secondary Consumers ◽  
Kootenai River ◽  
Stream Food Webs

Stream habitat changes affecting primary consumers often indirectly impact secondary consumers such as fishes. Blooms of the benthic algae Didymosphenia geminata (Didymo) are known to affect stream macroinvertebrates, but the potential indirect trophic impacts on fish consumers are poorly understood. In streams of the Kootenai River basin, we quantified the diet, condition, and growth rate of species of trout, char, and sculpin. In 2018, macroinvertebrate taxa composition was different between a stream with Didymo and a stream without, but trout diets, energy demand, and growth rates were similar. Trout abundance was higher in the stream with Didymo, but the amount of drifting invertebrates was higher in the stream without. In 2019, we surveyed 28 streams with a gradient of coverage. Didymo abundance was correlated only with the percentage of aquatic invertebrates in trout diets and was not related to diets of char or sculpin or condition of any species. Thus, we found no evidence for a trophic link between Didymo blooms and the condition or growth of trout, char, or sculpin in mountainous headwater streams.

Kootenay Lake: Man's Effects on the Salmonid Community

1972 ◽  
Vol 29 (6) ◽  
pp. 861-865 ◽  
Author(s):  
T. G. Northcote
Keyword(s):  
Stream Habitat ◽  
Growth Enhancement ◽  
Habitat Alteration ◽  
Dam Construction ◽  
Obvious Effect ◽  
Sport Fishery ◽  
Local Populations ◽  
Fishery Exploitation ◽  
Native Fishes ◽  
Kootenay Lake

A synopsis and evaluation is made of man's impact on Kootenay Lake salmonids since their first significant contact, perhaps less than 300 years ago. Exploitation of stocks for food by native Kootenay Indians was heavy in the late 1700s, probably surpassing present sport-fishery exploitation estimated at about 35 tons annually. Exploitation for fish-culture purposes never exceeded 7 tons annually, but because of restriction to a few spawning streams had serious effects on some local populations. Introduction of non-native fishes apparently was of little consequence to salmonids, whereas mysid introduction probably has produced growth enhancement in some stocks, especially kokanee. A similar but less obvious effect may be due to the marked cultural eutrophication occurring via heavy phosphate enrichment from a fertilizer plant. More serious and deleterious changes have been effected by stream habitat alteration resulting from mining, agriculture, and logging practices as well as from dam construction.

A novel ligand with –NH2 and –COOH-decorated Co/Fe-based oxide for an efficient overall water splitting: dual modulation roles of active sites and local electronic structure

2020 ◽  
Vol 10 (18) ◽  
pp. 6266-6273
Author(s):  
Yalan Zhang ◽  
Zebin Yu ◽  
Ronghua Jiang ◽  
Jung Huang ◽  
Yanping Hou ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Water Splitting ◽  
Energy Demand ◽  
Active Sites ◽  
Electrode Materials ◽  
Global Energy ◽  
Overall Water Splitting ◽  
Local Electronic Structure ◽  
Electrochemical Water Splitting

Excellent electrochemical water splitting with remarkable durability can provide a solution to satisfy the increasing global energy demand in which the electrode materials play an important role.

Fuzzy multi-objective decision making approach for nuclear power plant installation

2020 ◽  
Vol 39 (5) ◽  
pp. 6339-6350
Author(s):  
Esra Çakır ◽  
Ziya Ulukan
Keyword(s):  
Linear Programming ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Energy Supply ◽  
Energy Demand ◽  
Nuclear Power ◽  
Power Plants ◽  
Total Duration ◽  
Objective Functions ◽  
Multi Objective

Due to the increase in energy demand, many countries suffer from energy poverty because of insufficient and expensive energy supply. Plans to use alternative power like nuclear power for electricity generation are being revived among developing countries. Decisions for installation of power plants need to be based on careful assessment of future energy supply and demand, economic and financial implications and requirements for technology transfer. Since the problem involves many vague parameters, a fuzzy model should be an appropriate approach for dealing with this problem. This study develops a Fuzzy Multi-Objective Linear Programming (FMOLP) model for solving the nuclear power plant installation problem in fuzzy environment. FMOLP approach is recommended for cases where the objective functions are imprecise and can only be stated within a certain threshold level. The proposed model attempts to minimize total duration time, total cost and maximize the total crash time of the installation project. By using FMOLP, the weighted additive technique can also be applied in order to transform the model into Fuzzy Multiple Weighted-Objective Linear Programming (FMWOLP) to control the objective values such that all decision makers target on each criterion can be met. The optimum solution with the achievement level for both of the models (FMOLP and FMWOLP) are compared with each other. FMWOLP results in better performance as the overall degree of satisfaction depends on the weight given to the objective functions. A numerical example demonstrates the feasibility of applying the proposed models to nuclear power plant installation problem.

Biodiesel production from non-edible oils: A review

2020 ◽  
pp. 149-159
Author(s):  
Jatinder Kataria ◽  
Saroj Kumar Mohapatra ◽  
Amit Pal
Keyword(s):  
Environmental Impact ◽  
Energy Demand ◽  
Fossil Fuels ◽  
World Wide ◽  
Edible Oils ◽  
Control Measure ◽  
Biodiesel Production ◽  
Pollution Level ◽  
Animal Fats ◽  
The World

The limited fossil reserves, spiraling price and environmental impact due to usage of fossil fuels leads the world wide researchers’ interest in using alternative renewable and environment safe fuels that can meet the energy demand. Biodiesel is an emerging renewable alternative fuel to conventional diesel which can be produced from both edible and non-edible oils, animal fats, algae etc. The society is in dire need of using renewable fuels as an immediate control measure to mitigate the pollution level. In this work an attempt is made to review the requisite and access the capability of the biodiesel in improving the environmental degradation.

Direct ammonia fueled solid oxide fuel cells: A comprehensive review on challenges, opportunities and future outlooks

2020 ◽  
pp. 70-91 ◽  
Author(s):  
Molla Asmare ◽  
Mustafa Ilbas
Keyword(s):  
Electric Power ◽  
Energy Demand ◽  
Renewable Energy Sources ◽  
Clean Energy ◽  
Performance Comparison ◽  
Optimum Operating ◽  
Practical Implementation ◽  
Human Society ◽  
Energy Access ◽  
Green Fuel

Nowadays, the most decisive challenges we are fronting are perfectly clean energy making for equitable and sustainable modern energy access, and battling the emerging alteration of the climate. This is because, carbon-rich fuels are the fundamental supply of utilized energy for strengthening human society, and it will be sustained in the near future. In connection with this, electrochemical technologies are an emerging and domineering tool for efficiently transforming the existing scarce fossil fuels and renewable energy sources into electric power with a trivial environmental impact. Compared with conventional power generation technologies, SOFC that operate at high temperature is emerging as a frontrunner to convert the fuels chemical energy into electric power and permits the deployment of varieties of fuels with negligible ecological destructions. According to this critical review, direct ammonia is obtained as a primary possible choice and price-effective green fuel for T-SOFCs. This is because T-SOFCs have higher volumetric power density, mechanically stable, and high thermal shocking resistance. Also, there is no sealing issue problem which is the chronic issues of the planar one. As a result, the toxicity of ammonia to use as a fuel is minimized if there may be a leakage during operation. It is portable and manageable that can be work everywhere when there is energy demand. Besides, manufacturing, onboard hydrogen deposition, and transportation infrastructure connected snags of hydrogen will be solved using ammonia. Ammonia is a low-priced carbon-neutral source of energy and has more stored volumetric energy compared with hydrogen. Yet, to utilize direct NH3 as a means of hydrogen carrier and an alternative green fuel in T-SOFCs practically determining the optimum operating temperatures, reactant flow rates, electrode porosities, pressure, the position of the anode, thickness and diameters of the tube are still requiring further improvement. Therefore, mathematical modeling ought to be developed to determine these parameters before planning for experimental work. Also, a performance comparison of AS, ES, and CS- T-SOFC powered with direct NH3 will be investigated and best-performed support will be carefully chosen for practical implementation and an experimental study will be conducted for verification based on optimum parameter values obtained from numerical modeling.

BP Global Energy Outlook 2030

2013 ◽  
pp. 109-128 ◽  
Author(s):  
C. Rühl
Keyword(s):  
Emerging Economies ◽  
Energy Demand ◽  
Fossil Fuels ◽  
Net Energy ◽  
Global Energy ◽  
The Past ◽  
Market Shares ◽  
The Us ◽  
Almost All ◽  
Oil Gas

This paper presents the highlights of the third annual edition of the BP Energy Outlook, which sets out BP’s view of the most likely developments in global energy markets to 2030, based on up-to-date analysis and taking into account developments of the past year. The Outlook’s overall expectation for growth in global energy demand is to be 36% higher in 2030 than in 2011 and almost all the growth coming from emerging economies. It also reflects shifting expectations of the pattern of supply, with unconventional sources — shale gas and tight oil together with heavy oil and biofuels — playing an increasingly important role and, in particular, transforming the energy balance of the US. While the fuel mix is evolving, fossil fuels will continue to be dominant. Oil, gas and coal are expected to converge on market shares of around 26—28% each by 2030, and non-fossil fuels — nuclear, hydro and renewables — on a share of around 6—7% each. By 2030, increasing production and moderating demand will result in the US being 99% self-sufficient in net energy. Meanwhile, with continuing steep economic growth, major emerging economies such as China and India will become increasingly reliant on energy imports. These shifts will have major impacts on trade balances.

Oil Prices: Limits to Growth and the Depth of Falling

2006 ◽  
pp. 28-41 ◽  
Author(s):  
I. Bashmakov
Keyword(s):  
Energy Demand ◽  
Negative Relationship ◽  
Oil Prices ◽  
Production Factor ◽  
Energy Costs ◽  
Purchasing Power ◽  
Limits To Growth ◽  
Technological Basis ◽  
Production Factors ◽  
Output Ratio

This article deals with the determination of future oil prices. The approach used is based on the evaluation of purchasing power limits and allows to put the limits to monopolistic price setting. Several important findings are formulated: going beyond the upper thresholds of purchasing power stipulates negative relationship between energy costs and GDP growth rates, and this brings the dynamics to energy demand to price elasticity. This approach is also based on what the author calls the economics of constants and variables, i.e. on the existence of very stable macroeconomic proportions, which may be observed throughout the whole period of statistical observations (over 200 years). It provides grounds for two conclusions. First, the upper limit of energy costs to the gross output ratio is determined by the least acceptable profitability. Second, the theoretical postulate on substantial production factors substitution used in the production functions theory may be incorrect. In reality, the change of the economy technological basis leads to the substitution of low quality production factor by the same factor with a higher quality. Application of this approach brings the basis for predicting oil prices for 2006-2008.

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