scholarly journals ANALISIS ALIRAN BALIK (BACKWATER) PADA AMBANG GERIGI

2021 ◽  
Vol 14 (2) ◽  
pp. 61
Author(s):  
Winda Harsanti, ST., MT ◽  
Medi Efendi ◽  
Sitti Safiatus Riskijah
Keyword(s):  
Water Level ◽  
Water Flow ◽  
Open Channel ◽  
Channel Model ◽  
Step Method ◽  
Independent Variable ◽  
The Impact

Gerigi weir is a modificated jigsaw weir which can hold water flow to gain higher water level. This water raising happens in upstream of the weir until certain length to reach normal depth. This research uses square open channel model with slope as an independent variable. In this research uses various slope from 1‰ to 5‰ for eight different discharges. The aim of this research is to find the impact of slope for backwater length using Direct Step Method. The result of this research is the longest back water happened in the 8th of experiment discharge (1399,984 cm3/sec) with the slope of 3‰, by 40.800,4952 cm from the weir. In addition, slope is not affect for the length of backwater. This is because from all analysis of experiments, the longest backwater happens in different slope for each discharge, namely between 1‰, 3‰, or 4‰ of slope.                      Keywords: back water, gerigi weir, slope

scholarly journals Assessment of the position of the project water flow in the lower reaches of hydroelectric facilities, using the example of the novosibirsk hydroelectric power station

2021 ◽  
Vol 2131 (3) ◽  
pp. 032075
Author(s):  
N Akhmatova ◽  
T Mikhaylova ◽  
T Pilipenko
Keyword(s):  
Water Level ◽  
Water Flow ◽  
Building Materials ◽  
Anthropogenic Impacts ◽  
Design Flow ◽  
Hydroelectric Power Station ◽  
Hydroelectric Power ◽  
Channel Deformation ◽  
The Impact ◽  
Fish Industry

Abstract Construction of large hydroelectric complexes on the plain rivers of Western Siberia, such as the Ob, as well as other types of anthropogenic impact (infill development, quarrying of nonmetallic building materials, carrying out track works, laying communications, wastewater discharges, etc.) lead to a change in water and channel regimes, hydrological characteristics, channel deformation in the downstream. One of these changes is the landing of water level in the section of the lower pond of the Ob from the Novosibirsk hydroelectric complex to the mouth of the Tom River, which adversely affects navigable conditions of this stretch, operation of water intakes, port and sluice, and also damages the fish industry. The landing of the water level continues to this day, and in order to maintain the design water level, it becomes necessary to increase navigation releases. The design level was changed several times after the commissioning of the Novosibirsk hydroelectric complex due to its low availability, a further change in the availability will lead to a change in the design level mark, or rather its lowering. Therefore, the purpose of the study is to assess the position of the design flow rate at the established design level and make a forecast of changes in water flow depending on the time that has passed since the start of operation of the Novosibirsk hydroelectric complex, taking into account the impact on the channel, carried out dredging works, as well as other types of anthropogenic impacts.

scholarly journals Regression Examination Technique: Correlation between Nozzle Velocity and Vibration Level of Hydro-Turbine in SHP Run-off-River Scheme

2019 ◽  
Vol 8 (6) ◽  
pp. 3404-3413
Keyword(s):  
Water Level ◽  
Flow Rate ◽  
Vibration Level ◽  
Rainfall Distribution ◽  
Run Off ◽  
Statistical Analysis Method ◽  
Measured Flow ◽  
Independent Variable ◽  
One Year ◽  
The Impact

Regression Examination is one of the most popular statistical analysis method used to determine the correlation between examined variables. It can also be used to predict the value of a dependent variable based on the value of at least one independent variable and this will allow explaining the impact of changes in an independent variable on the dependent variable. With the measured data of flow rate, output power and efficiency of turbine system, the nozzle velocity can be calculated using an appropriate mathematical equation. Along with vibration level data at every measurement axes, they are tabulated and imported into MATLAB program for the correlation determination. Three different set of data are used in this analysis which is based on the variation of water level at different month (low, typical and high) due to rainfall distribution within one year period. The objective of this study was to examine two questions: first is the effect of water level to the measured flow rate and generated output as well the calculated nozzle velocity. Second, with these variation of nozzle velocity, how significance their correlation with the vibration level at multiple axes of the turbine and generator? From the results, it has been discovered that there are significant correlation between nozzle velocity and vibration level, particularly during low level of water (lower rainfall distribution)

A Study of the Average Flow in Open Channel with Baffle Blocks Distributed Uniformly

10.29007/zx1w ◽  
2018 ◽  
Author(s):  
Dung Tien Tran ◽  
Anh Tuan Le ◽  
Hong Nhung Le ◽  
Viet Hung Ho
Keyword(s):  
Water Level ◽  
Water Depth ◽  
Open Channel ◽  
Block Size ◽  
Average Flow ◽  
Modelling Studies ◽  
Baffle Block

A study of average flow in open channel with baffle blocks distributed uniformly has been considered by using channel with varied slopes. In this article, experimental and modelling studies were introduced when the correlation between the water depth and baffle block size is significant. The objective of the work is to give the rudimentary relations between discharge and water level in the channels. When the water depth is large, the effect of bottom channel friction on the flow is relatively small. This paper also gives applications of the software ‘Telemac-2D’ to simulate the flow under different conditions.

تأثير الاستثمار الاجنبي المباشر في القيمة السوقية للشركة (دراسة تطبيقية في شركة بترو جانيا الصينية في عقود التراخيص النفطية للجولة الاولى والثانية في الحقول النفطية في العراق للمدة من 2017-2010)

2020 ◽  
Vol 2020 (66) ◽  
pp. 65-85
Author(s):  
هيثم عبد النبي موسى ◽  
أ .د حيدر نعمة غالي الفريجي
Keyword(s):  
Foreign Direct Investment ◽  
Stock Prices ◽  
Return On Investment ◽  
Direct Investment ◽  
Inverse Correlation ◽  
Market Value ◽  
Political Stability ◽  
Coefficient Of Determination ◽  
Independent Variable ◽  
The Impact

This study dealt with the effect of foreign direct investment on the market value of the company during the period of time (2010-2017). This issue was studied through a sample of oil fields in southern Iraq in which the company operates within the first and second licensing contracts rounds and according to the circumstances and variables of the investment environment as it is. Although this investment often achieves high returns, it is also characterized by a high degree of risk and for the purpose of evaluating the impact of foreign direct investment on the market value of the company's stock prices for the period (2010-2017). The statistical scale (T-TEST) was used to indicate the significance of the correlation hypotheses. Between the return on investment as the independent variable and the market value as the dependent variable, and the use of the coefficient of determination (R2) that measures the effect of the independent variable (foreign direct investment) on the dependent variable (market value) and the F-Test to demonstrate acceptance or rejection of the hypothesis of the return on investing in the market value of the oil company, and if the company achieves a high return in foreign direct investment, the market value of it will be affected positively. The study was based on a set of goals, including determining the attractiveness of Iraq to foreign investments, especially the oil sector, and the study reached a number of conclusions, the most prominent of which is the existence of a strong inverse correlation between the return on investment and the market value of the company. And the existence of a slight impact of the return on investment on the market value of the company, and the study reached a number of recommendations, the most important of which is activating the investment climate through political stability and the clarity and stability of laws and legislation regulating investment, which is one of the most important factors affecting the investment decision.

scholarly journals Profile of the Change in Depression during Proton-Pump Inhibitor Therapy in Patients with Gastroesophageal Reflux Disease: Influence of the Mucosal Break

2021 ◽  
Vol 18 (11) ◽  
pp. 5964
Author(s):  
Chia-Liang Wu ◽  
Chien-Lin Chen ◽  
Shu-Hui Wen
Keyword(s):  
Gastroesophageal Reflux Disease ◽  
Gastroesophageal Reflux ◽  
Proton Pump ◽  
Reflux Disease ◽  
Proton Pump Inhibitor Therapy ◽  
Linear Regression Models ◽  
Independent Variable ◽  
The Difference ◽  
Mucosal Break ◽  
The Impact

Given the frequent concomitance between depression and gastroesophageal reflux disease (GERD), it is important to evaluate the change of depression in patients with GERD, especially considering the presence of esophageal mucosal breaks (MB). This study aimed to examine the change in the levels of depression in patients with GERD during proton-pump inhibitors (PPI) therapy. We designed a prospective cohort study to explore the profile of the alteration in depression with respect to the impact of esophageal MB. This study recruited 172 eligible patients with GERD between February 2016 and May 2018. The change in depression was defined as the difference between the respective Taiwanese Depression Questionnaire (TDQ) scores obtained at baseline and after PPI therapy. Multivariate linear regression models were used to estimate the factors associated with the change in depression. The results revealed statistically significant improvements in the TDQ score (mean score: baseline = 13.2, after PPI therapy = 10.9, p < 0.01, Cohen’s d = 0.30) during PPI therapy for GERD. Moreover, the MB was an independent variable associated with changes in the TDQ score [B = 3.31, 95% confidence interval (CI): (1.12, 5.51), p < 0.01] and the improvement in depression [odds ratio = 0.38, 95% CI: (0.17, 0.86), p = 0.02]. Our findings revealed that depressive symptoms improved slightly following PPI therapy. Moreover, MB was an unfavorable prognostic factor for the improvement in depression.

scholarly journals Assessing Stream-Aquifer Connectivity in a Coastal California Watershed

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 416
Author(s):  
Bwalya Malama ◽  
Devin Pritchard-Peterson ◽  
John J. Jasbinsek ◽  
Christopher Surfleet
Keyword(s):  
Time Series ◽  
Spectral Analysis ◽  
Water Level ◽  
Time Series Data ◽  
Series Data ◽  
Low Permeability ◽  
Pumping Tests ◽  
Stream Flows ◽  
The Impact

We report the results of field and laboratory investigations of stream-aquifer interactions in a watershed along the California coast to assess the impact of groundwater pumping for irrigation on stream flows. The methods used include subsurface sediment sampling using direct-push drilling, laboratory permeability and particle size analyses of sediment, piezometer installation and instrumentation, stream discharge and stage monitoring, pumping tests for aquifer characterization, resistivity surveys, and long-term passive monitoring of stream stage and groundwater levels. Spectral analysis of long-term water level data was used to assess correlation between stream and groundwater level time series data. The investigations revealed the presence of a thin low permeability silt-clay aquitard unit between the main aquifer and the stream. This suggested a three layer conceptual model of the subsurface comprising unconfined and confined aquifers separated by an aquitard layer. This was broadly confirmed by resistivity surveys and pumping tests, the latter of which indicated the occurrence of leakage across the aquitard. The aquitard was determined to be 2–3 orders of magnitude less permeable than the aquifer, which is indicative of weak stream-aquifer connectivity and was confirmed by spectral analysis of stream-aquifer water level time series. The results illustrate the importance of site-specific investigations and suggest that even in systems where the stream is not in direct hydraulic contact with the producing aquifer, long-term stream depletion can occur due to leakage across low permeability units. This has implications for management of stream flows, groundwater abstraction, and water resources management during prolonged periods of drought.

scholarly journals Calcium phosphate phase transition in the presence of Aminosilane

2014 ◽  
Vol 70 (a1) ◽  
pp. C67-C67
Author(s):  
Babak Mostaghaci ◽  
Brigitta Loretz ◽  
Robert Haberkorn ◽  
Guido Kickelbick ◽  
Claus-Michael Lehr
Keyword(s):  
Phase Transition ◽  
Calcium Phosphate ◽  
Blood Compatibility ◽  
Transfection Efficiency ◽  
Hek293 Cells ◽  
Step Method ◽  
Calcium Phosphate Nanoparticles ◽  
Amine Groups ◽  
The Impact

Calcium phosphate has been the point of interest for in vitro gene delivery for many years because of its biocompatibility and straight forward application. However, there are some limitations regarding in vivo administration of these particles mostly because of vast agglomeration of the particles and lack of strong bond between the particles and pDNA. We introduced a simple single step method to functionalize calcium phosphate nanoparticles with Aminosilanes having a different number of amine groups. The nanoparticles were characterized chemically and structurally and their toxicity and interaction with pDNA were studied as well. Results revealed that different crystalline phase of calcium phosphate nanoparticles (Brushite and Hydroxyapatite) with a size below 150 nm were prepared, depending on conditions of synthesis and phase, each with a narrow size distribution. The aminosilane agents caused oriented nucleation and growth of crystallites and can decrease the pH for producing hydroxyapatite phase. The phenomenon could be revealed with the presence of anisotropy in the structure of synthesized hydroxyapatite. The number of amine groups in the Aminosilane agent could change the phase transition pH. Brushite particles revealed to have stronger interaction with pDNA mostly because of their higher positive surface charge. Both particles showed blood compatibility and negligible toxicity. Transfection experiment revealed the capability of both brushite and hydroxyapatite particles to transfect A549 and HEK293 cells. The new modified nanoparticles can be stored in a dried state and re-dispersed easily at the time of administration. Moreover, the transfection efficiency is higher in comparison with conventional calcium phosphate. This study showed the impact of presence and type of the modifying agent on the crystal structure and the amount of surface functionalization of nanoparticles, which in consequence influenced their interaction with cells.

scholarly journals Joint UAV channel modeling and power control for 5G IoT networks

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Xiuhua Fu ◽  
Tian Ding ◽  
Rongqun Peng ◽  
Cong Liu ◽  
Mohamed Cheriet
Keyword(s):  
Energy Efficiency ◽  
Power Control ◽  
Channel Model ◽  
Path Loss ◽  
Channel Modeling ◽  
Signal Propagation ◽  
Spectrum Efficiency ◽  
Propagation Path ◽  
Control Factor ◽  
The Impact

AbstractThis paper studies the communication problem between UAVs and cellular base stations in a 5G IoT scenario where multiple UAVs work together. We are dedicated to the uplink channel modeling and the performance analysis of the uplink transmission. In the channel model, we consider the impact of 3D distance and multi-UAVs reflection on wireless signal propagation. The 3D distance is used to calculate the path loss, which can better reflect the actual path loss. The power control factor is used to adjust the UAV's uplink transmit power to compensate for different propagation path losses, so as to achieve precise power control. This paper proposes a binary exponential power control algorithm suitable for 5G networked UAV transmitters and presents the entire power control process including the open-loop phase and the closed-loop phase. The effects of power control factors on coverage probability, spectrum efficiency and energy efficiency under different 3D distances are simulated and analyzed. The results show that the optimal power control factor can be found from the point of view of energy efficiency.

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