scholarly journals An Assessment of Self-Purification in Streams

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 87
Author(s):  
Valentinas Šaulys ◽  
Oksana Survilė ◽  
Rasa Stankevičienė
Keyword(s):  
Confidence Level ◽  
Average Concentration ◽  
The Self ◽  
Drainage Systems ◽  
Natural Stream ◽  
Excess Water ◽  
Natural Streams ◽  
Average Coefficient ◽  
Eastern Highlands ◽  
Coastal Lowlands

The territory of Lithuania is characterized by a prevailing moisture excess, therefore in order to timely remove excess water from arable lands, the drainage systems have long been installed. In order to drain excess water people used to dig trenches, to regulate (deepen or straighten) natural streams. The length of regulated streams has reached 46,000 km and they are deteriorated ecosystems. Investigations showed that the self-purification of streams from nitrates and phosphates is more effective in natural stretches than in stretches regulated for drainage purposes. Decrease in the average concentration of nitrates in natural and regulated stretches are 8.8 ± 5.0 and 3.0 ± 2.9 mg NO 3 − L−1, respectively. The average coefficient of nitrate self-purification, at a confidence level of 95% in natural stream stretches is 0.50 ± 0.22, and in regulated is −0.15 ± 0.21 km−1, and this difference is essential. The change in the average concentration of phosphates in natural and regulated stretches is almost the same, 0.2 ± 0.1 and 0.2 ± 0.2 mg PO 4 3 − L−1, respectively. The average coefficient of phosphate self-purification, at a confidence level of 95%, in natural stream stretches is 0.28 ± 0.12, in regulated −0.14 ± 0.12 km−1, and this difference is not essential. In terms of the need for the renovation of drainage systems it is suggested that soft naturalization measures are first applied in the streams of Western (Samogitian) Highlands, Coastal Lowlands, and South-Eastern Highlands to improve their self-purification processes.

An Assessment of Self-purification of Regulated and Natural Streams

2017 ◽  
Author(s):  
Oksana Survilė ◽  
Valentinas Šaulys ◽  
Auksė Stanionytė
Keyword(s):  
Water Quality ◽  
Nitrate Concentration ◽  
Surface Water Quality ◽  
Woody Vegetation ◽  
Natural Stream ◽  
Natural Streams ◽  
Average Coefficient ◽  
Different Seasons ◽  
Regulated Stream ◽  
Stream Nitrate

In these latter days it has become topical to reconsider, the technologies and practice of regulated for drainage purposes streams supervision, to find ways how to combine agricultural productivity and restore lost ecological balance at least partially. The article analyzes the influence of natural and regulated stream stretches on water quality and stream self-purification effectiveness. The analysis of nitrate concentration in water samples taken from natural and regulated stream stretches was conducted for the identification of water quality. Nitrate (NO3) concentrations and their alternation during different seasons were studied. The conducted analysis revealed that stream nitrate self-purification is better in natural stream stretches. An average coefficient of self-purification recorded in the course of the research in natural stretches was 0.57, whereas in a regulated stretch – 0.09. On purpose to improve surface-water quality and self-purifi-cation effectiveness it is suggested to naturalize regulated stream stretches, to allow woody vegetation grow on slopes, to encourage meandering, pools and shoals forming processes in floodplains.

Seepage through Earth Dams with Chimney Drain on Pervious Foundation

2012 ◽  
Vol 452-453 ◽  
pp. 538-542 ◽  
Author(s):  
Abdelkader Djehiche ◽  
Rekia Amieur ◽  
Mustafa Gafsi
Keyword(s):  
Experimental Study ◽  
Flow Rate ◽  
Drainage System ◽  
Earth Dam ◽  
Earth Dams ◽  
Drainage Systems ◽  
The Earth ◽  
Excess Water ◽  
Effective Drainage

This paper presents an experimental study of a homogenous earth dam. The work is focused to the search of solutions of problems encountered in the earth dams after their construction. One of the major problems is the choice and design of systems of drainage. The effective drainage system to prevent harmful accumulations of excess water is one of the most important roles of dams. Efficient drainage systems can improve the safety of earth dams. The paper presented herein reports the results obtained from the experimental study. Empiric relations have been obtained which can be help in the control of the flow rate in the chimney drain of the earth dams on pervious foundation, which can increase safety earth dams

Migratory Behavior of Chinook Salmon Microjacks Reared in Artificial and Natural Environments

2014 ◽  
Vol 6 (1) ◽  
pp. 176-186
Author(s):  
Michael C. Hayes ◽  
Stephen P. Rubin ◽  
Reginald R. Reisenbichler ◽  
Lisa A. Wetzel
Keyword(s):  
Chinook Salmon ◽  
Oncorhynchus Tshawytscha ◽  
Condition Factor ◽  
Late Summer ◽  
Natural Environments ◽  
Wild Populations ◽  
Negative Effects ◽  
Natural Stream ◽  
Natural Streams ◽  
Experimental Release

Abstract Emigration was evaluated for hatchery Chinook salmon (Oncorhynchus tshawytscha) microjacks (age-1 mature males) and immature parr (age-1 juveniles, both sexes) released from both a hatchery and a natural stream (fish released as fry). In the hatchery, volitional releases (∼14 to 15 months post-fertilization) to an adjacent river occurred during October–November. The hatchery release was monitored by using an experimental volitional release that diverted fish to a neighboring raceway. Fish captured during the experimental release (range 361–4,321 volitional migrants) were made up of microjacks and immature parr. Microjacks were found only in the migrant samples, averaged 18% (range 0–52%) of all migrants, and were rarely found in non-migrant samples. In comparison, immature parr were common in both the migrant and non-migrant samples. Microjacks were significantly longer (9%), heavier (36%), and had a greater condition factor (16%) than migrant immature parr (P < 0.01). In addition, they differed significantly (P < 0.01) from non-migrant immature parr; 10% longer, 44% heavier and 14% greater condition factor. In natural streams, microjacks were captured significantly earlier (P < 0.01) than immature parr during the late-summer/fall migration and comprised 9–89% of all fish captured. Microjacks have the potential to contribute to natural spawning populations but can also represent a loss of productivity to hatchery programs or create negative effects by introducing non-native genes to wild populations and should be monitored by fishery managers.

Empirical Study of the Effect of Surya Namaskar Yognidra and Chanting of ‘Aum’ On the Self Confidence Level of Children

2016 ◽  
Vol 3 (4) ◽  
Author(s):  
Dr. Upendra Babu Khatri
Keyword(s):  
Empirical Study ◽  
Confidence Level ◽  
The Self ◽  
Self Confidence

Suryanamaskar, Yognidra and the chanting of AUM is essential and unavoidable for today’s misguided youth if indeed the country needs a generation filled with the jewel of self confidence and they will have to be kept from coming into the grips of depression , emotional imbalances and most importantly children will have to be motivated by inculcating among them as inclination to follow yogic practices by the parents  and the teachers themselves presenting Yoga driven character before their children. Succinctly put, Yogic practices have the capability of bringing about numerous positive changes in one’s being and more so when it comes to the teenagers as has been proved in the case study delineated above.

scholarly journals Analysis of the Flood Performance of Stormwater Drainage Systems for Different Return Periods

2021 ◽  
Author(s):  
Burak ÇIRAĞ ◽  
◽  
Mahmut FIRAT ◽  
Özgüray AYDIN ◽  
◽  
...  
Keyword(s):  
Urban Areas ◽  
Application Area ◽  
Drainage Systems ◽  
Irregular Structures ◽  
Digital Elevation ◽  
Precipitation Behaviour ◽  
Precipitation Regimes ◽  
Natural Streams ◽  
Drainage Line ◽  
Elevation Model

Precipitation regimes and behaviours change depending on the climate change. As the duration of precipitation decreases its intensity increases. On the other hand, the density of buildings increases in urban areas, and drainage systems remain inadequate as a result of deterioration in the structure of natural streams and irregular structures. Due to the change in precipitation behaviour and the decrease in permeable surfaces in urban areas, urban floods lead to serious damage. In this study, it is aimed to analyse the flood performance of rainwater drainage systems currently serving in urban areas for precipitation with different repetition periods. For this purpose, the drainage line in Malatya provincial centre has been selected as the pilot application area. Considering the rainfall records observed in the past, a model was created for 15 minutes of precipitation and 2, 5 and 10 years repetition periods. In addition, the digital elevation model, drainage line and characteristic information and building layouts were taken into consideration in the application area. As a result of the analysis, flood spread maps were created. It has been observed that as the repetition period increases, the rainwater drainage line is insufficient in some areas and may cause loss of property and life.

scholarly journals Analysis of the Self-Confidence Level of Grade 4 Students at SD N 2 Brecong in Entrepreneurship Learning

2019 ◽  
Vol 2 (1) ◽  
pp. 232
Author(s):  
Arief Muhamad Fachrur Rozi ◽  
Siti Fatimah
Keyword(s):  
Data Analysis ◽  
Data Collection ◽  
Confidence Level ◽  
The Self ◽  
Descriptive Data ◽  
Entrepreneurial Learning ◽  
School Year ◽  
Self Confidence ◽  
Learning Success ◽  
Fourth Grade Students

Self confidence is one of the factors that influences learning success. This study aims to analays the level of self-confidence of students in grade 4 at SD N 2 Brecong on entrepreneurial learning. This research was conducted at SD N 2 Brecong class 4 in the 2019/2020 school year. The design of this research is simple descriptive. Data collection techniques using observation and questionnaires with a population of 35 students. Data analysis was performed using descriptive techniques. Based on the results of the study it can be concluded that the confidence of grade 4 students at SD N 2 Brecong is good in their confidence. Entrepreneurial learning becomes a container in developing student learning confidence. The fourth grade students' self confidence developed at SD N 2 Brecong is supported by being independent, active in learning, discipline and responsibility.

A Technique for the Mathematical Modelling of Mixing in Natural Streams

1971 ◽  
Vol 6 (1) ◽  
pp. 145-159
Author(s):  
R. C. Hudspith ◽  
J. D. Norman
Keyword(s):  
Experimental Data ◽  
Mathematical Modelling ◽  
Frequency Response ◽  
Plug Flow ◽  
Natural Stream ◽  
Lumped Parameter ◽  
Lumped Parameter Models ◽  
Natural Streams ◽  
Mixing Dynamics ◽  
Experimental Runs

Abstract Frequency response techniques are employed to characterize the mixing dynamics in a natural stream. Lumped parameter models, consisting of regions of complete mixing and plug flow, are formulated in such a way as to simulate the mechanisms causing mixing in the real system. The models are fitted to the experimental data in the frequency domain using a least squares criteria. The results of a series of experimental runs on a real stream are presented. A pulse of fluorescent dye is injected at one point and is measured as it passes a second point downstream. The dominant mechanisms causing mixing in the stream studied are irregular velocity profiles and an exchange of mass with relatively stagnant regions along the bottom and shorelines. A model to simulate these mechanisms is presented and the parameters are evaluated as a function of streamflow

Influence of salmon spawner densities on stream productivity in Southeast Alaska

1999 ◽  
Vol 56 (9) ◽  
pp. 1600-1611 ◽  
Author(s):  
Mark S Wipfli ◽  
John P Hudson ◽  
Dominic T Chaloner ◽  
John P Caouette
Keyword(s):  
Chlorophyll A ◽  
Pink Salmon ◽  
Dry Mass ◽  
Trophic Levels ◽  
Oncorhynchus Gorbuscha ◽  
Southeast Alaska ◽  
Natural Stream ◽  
Forest Stream ◽  
Natural Streams ◽  
Freshwater Salmon

We conducted this study to determine the relationship between salmon spawner abundance and stream biofilm and benthic macroinvertebrate abundance in Southeast Alaska. Experiments took place in outdoor artificial and natural streams. Six pink salmon (Oncorhynchus gorbuscha) carcass treatments (0.00, 1.45, 2.90, 4.35, 5.80, and 7.25 kg wet mass) placed in artificial channels were subsampled repeatedly for biofilm ash-free dry mass (AFDM), chlorophyll a, and macroinvertebrates. In a small (nonanadromous) forest stream, we sampled benthos throughout a 66-m reach 17 days after distributing 60 carcasses along the lower half of that reach. All response variables significantly increased in response to carcass additions in both artificial and natural streams. Chlorophyll a continued to increase across all loading rates, while AFDM and total macroinvertebrate densities showed no further response to loading beyond the first treatment (1.45 kg) in artificial streams. In the natural stream, AFDM and chironomid densities continued increasing across loading levels. These results indicated that increased spawner densities increased lower trophic level abundance until a trophic capacity was reached. Salmon escapement goals should consider food web effects, especially on trophic levels that support juvenile salmonids, that ultimately affect freshwater salmon production.

Synthesis and properties of a novel naphthyl-containing self-promoted phthalonitrile polymer

2017 ◽  
Vol 30 (9) ◽  
pp. 1114-1122 ◽  
Author(s):  
Jian Wang ◽  
Chao Chen ◽  
Xinggang Chen ◽  
Haifeng Wang ◽  
Xiaoyan Yu ◽  
...  
Keyword(s):  
Coefficient Of Thermal Expansion ◽  
Complex Viscosity ◽  
The Self ◽  
Process Window ◽  
One Pot ◽  
Average Coefficient ◽  
Long Time ◽  
Cure Temperature ◽  
Low Complex ◽  
High Storage

A novel naphthyl-based self-promoted phthalonitrile monomer, 4-(8-amino-2-naphthyloxy)phthalonitrile (8-ANP), was successfully synthesized via nucleophilic substitution reaction through a one-pot reaction, and it exhibited desirable processing feature with a wide process window (temperature between the melting point and the cure temperature) and low complex viscosity. The activation energy ( Ea) value of the self-promoted curing reaction was ascertained using integral isoconversional Starink method. Even without post cure at high temperature for a long time, the properties of 8-ANP polymers were still outstanding, which exhibited high glass transition temperatures, high storage modulus, low average coefficient of thermal expansion, and excellent thermal and thermo-oxidative stabilities.

scholarly journals Self-Employment and Economic Empowerment: A Case of Pot Makers

2019 ◽  
Vol 6 (4) ◽  
pp. 1-8
Author(s):  
Harish Tigari ◽  
K P Ashwini
Keyword(s):  
Confidence Level ◽  
The Self ◽  
Economic Empowerment ◽  
Men And Women ◽  
Self Employment ◽  
Modern Era

As we know the self-employment is the opportunity of creating platform for the development of each in their ways. It develops the confidence level and helps to explore them self without restriction and conditions. The self-employment is a key element for the development of economic empowerment. It creates values in the society and makes everyone equal. It provides opportunities for both men and women they are equally contributing for the development of economy, so the pot makers are the best examples for the self-employment development. Here this research mainly focused on pot makers and collected information from history to the modern era. In history pot playing an important role and it used for many traditional purposes but now plastics become compotators for this pot. So it is diminishing the value and percentage of self-employment ratio.

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