Pollution control of alluvial aquifers infiltrated by diesel oil: impact of fluctuating water level on the degree of groundwater contamination

1995 ◽  
Vol 32 (8) ◽  
pp. A365
Keyword(s):  
Groundwater Contamination ◽  
Water Level ◽  
Pollution Control ◽  
Diesel Oil ◽  
Alluvial Aquifers ◽  
Fluctuating Water Level

scholarly journals On a predator-prey system interaction under fluctuating water level with nonselective harvesting

2020 ◽  
Vol 18 (1) ◽  
pp. 458-475
Author(s):  
Na Zhang ◽  
Yonggui Kao ◽  
Fengde Chen ◽  
Binfeng Xie ◽  
Shiyu Li
Keyword(s):  
Water Level ◽  
Equilibrium Points ◽  
Sufficient Conditions ◽  
Optimal Harvesting ◽  
Positive Equilibrium ◽  
Predator Population ◽  
Model Interaction ◽  
Predator Prey ◽  
Predator Prey Model ◽  
Fluctuating Water Level

Abstract A predator-prey model interaction under fluctuating water level with non-selective harvesting is proposed and studied in this paper. Sufficient conditions for the permanence of two populations and the extinction of predator population are provided. The non-negative equilibrium points are given, and their stability is studied by using the Jacobian matrix. By constructing a suitable Lyapunov function, sufficient conditions that ensure the global stability of the positive equilibrium are obtained. The bionomic equilibrium and the optimal harvesting policy are also presented. Numerical simulations are carried out to show the feasibility of the main results.

The biology of Butomus umbellatus in shallow waters with fluctuating water level

1996 ◽  
pp. 27-30 ◽  
Author(s):  
Zdenka Hroudová ◽  
Anna Krahulcová ◽  
Petr Zákravský ◽  
Vlasta Jarolímová
Keyword(s):  
Water Level ◽  
Shallow Waters ◽  
Fluctuating Water Level

The life histories of Limnephilus externus Hagen, Anabolia bimaculata (Walker), and Nemotaulius hostilis (Hagen) (Trichoptera, Limnephilidae) in a pond in southern Alberta, Canada

1986 ◽  
Vol 64 (10) ◽  
pp. 2348-2356 ◽  
Author(s):  
Stephen B. Berté ◽  
Gordon Pritchard
Keyword(s):  
Water Level ◽  
Life Histories ◽  
Larval Growth ◽  
Metabolic Cost ◽  
Late Summer ◽  
Adult Emergence ◽  
High Water ◽  
Reproductive Diapause ◽  
Fluctuating Water Level ◽  
The Masses

Limnephilus externus and Anabolia bimaculata are caddisflies that typically inhabit temporary pools, while Nemotaulius hostilis is a species that inhabits permanent pools. In a permanent pond with a fluctuating water level, both groups could be accommodated. The temporary-pool species laid egg masses on the ground above the water level in late summer. Larvae hatched in the autumn but remained in the masses until submersed by the rising water in the spring. Larvae grew at rates faster than those for any permanent-water trichopteran studied to date. Limnephilus externus adults emerged through August and underwent a 1-month reproductive delay. Anabolia bimaculata adults emerged through July, but showed no signs of a reproductive delay. By contrast, N. hostilis oviposited on riparian vegetation and larvae entered the water on hatching in August. Larval growth rates approximated those of other detritivorous shredders found in permanent waters. Over 75% of adult emergence occurred in 1 week at the end of May and adults underwent a reproductive diapause of slightly over a month's duration. The metabolic cost of high water temperatures on cool-adapted limnephilid caddisflies is postulated as the driving force behind the evolution of reproductive diapause in this family.

scholarly journals PENGARUH PENAMBAHAN OKSIGENAT PADA SOLAR TERHADAP EMISI GAS BUANG MESIN DIESEL

2019 ◽  
Vol 3 (1) ◽  
pp. 30-39
Author(s):  
Yos Nofendri
Keyword(s):  
Air Pollution ◽  
Diesel Engine ◽  
Pollution Control ◽  
Exhaust Emissions ◽  
Diesel Oil ◽  
Exhaust Emission ◽  
Gas Analyzer ◽  
Vehicle Exhaust ◽  
Strict Enforcement ◽  
Load Conditions

ABSTRAK Penurunan kualitas udara pada bumi terus menurun. Ini disebabkan oleh polusi udara semakin lama semakin meningkat. Peningkatan jumlah kendaraan juga menjadi salah satu penyebab menurunnya kualitas udara. Penegakan aturan yang ketat dalam pengendalian pencemaran pada emisi gas buang semakin diperketat. Oleh itu diperlukan suatu bahan bakar kendaraan yang dapat mengurangkan emisi gas buang pada kendaraan. Pada saat sekarang ini pencarian bahan bakar ramah lingkungan difokuskan dengan menggunakan aditif berbahan dasar alami. Dengan demikian perlu diteliti penambahan aditif ditambahkan ke minyak solar, dengan tujuan untuk mengurangi emisi gas buang. Sebuah mesin diesel satu silinder telah digunakan yang digabungkan gas analyzer Bosc tipe BEA 150 / 250 / 350. Oksigenat berbahan dasar nabati digunakan sebagai aditif dalam bahan bakar diesel dengan campuran 1% - 5% volume. Tes emisi gas buang dilakukan pada kecepatan antara 900 - 1.700 rpm dan kondisi beban penuh. Percobaan dilakukan untuk mendapatkan parameter emisi gas buang. Hasil percobaan menunjukkan bahwa penambahan aditif oksigenat sebanyak 1 % bisa menurunkan jelaga 30%, meningkatkan CO2 sebanyak 5%, menurunkan CO 35% dan peningkatan NOx sebanyak 9% dibanding solar murni. Kata Kunci : Mesin diesel, Oksigenat, Emisi Gas Buang ABSTRACT Decline in air quality on earth continues to occur. One of its causes is air pollution which is the mistake of vehicle exhaust emissions. Strict enforcement of pollution control on exhaust emissions is one way to control exhaust emissions. It is therefore necessary to fuel a vehicle that can reduce exhaust emissions on vehicles. At the present time this environmentally friendly fuel search is focused using natural based additives. Thus it is necessary to examine the addition of additives added to the diesel oil, with the aim of reducing exhaust emissions. A single-cylinder diesel engine has been used which incorporates a BEA 150/250/350 Bosc gas analyzer. Vegetable oxygenates are used as additives in diesel fuel with a mixture of 1% - 5% by volume. The exhaust emission test is carried out at speeds between 900 - 1,700 rpm and full load conditions. The experiment was conducted to obtain the parameters of exhaust emissions. The experimental results show that the addition of 1% oxygenate additive can decrease carbon 30%, increase CO2 by 5%, decrease CO 35% and increase NOx by 9% compared to pure diesel. Keyword : Diesel Engine, Oxygenat, Emission Engine

scholarly journals Lake Chad: Fluctuating Water Level and Its Implications for People’s Livelihood in the Area

2021 ◽  
Vol 9 (2) ◽  
pp. 1-8
Author(s):  
Asiru Monday Abbas ◽  
Unekwu Hadiza Amanabo
Keyword(s):  
Water Level ◽  
Protected Area ◽  
Agricultural Practices ◽  
Food Aid ◽  
Agricultural Activities ◽  
Negative Effects ◽  
Environmental Sciences ◽  
Boko Haram ◽  
Lake Chad ◽  
Fluctuating Water Level

This study assessed the fluctuating water level of Lake Chad and its consequences on the livelihood of people that depend on it. In terms of depth, Lake Chad is very shallow which makes it vulnerable to climate change and human activities. The study opined that continuous reduction in the volume of water of the lake will lead to negative effects such as forceful migration, resource-induced conflict, loss of biodiversity etc. Insurgency spear-headed by Nigeria based terrorist organization, “Boko Haram”, has killed many people including farmers and fishermen in the riparian countries of Nigeria, Niger, Chad and Cameroun and this has led to a decline in agricultural activities around the Lake Chad area making many to depend on food aid for their survival. The insurrectional activity of the terrorist group around the Lake Chad area also makes trade between communities extremely difficult as they are known to have attacked and killed people inside market. It is recommended that measures such as livelihood diversification through technology, creation of protected area, improved agricultural practices etc. should be adopted to reduce pressure on the lake and its resources. The Dhaka University Journal of Earth and Environmental Sciences, Vol. 9(2), 2020, P 1-8

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