scholarly journals Discharge Measurements by a New-Formed Relative Salt-Dilution Method in Small Turbulent Streams

1980 ◽  
Vol 11 (3-4) ◽  
pp. 121-132 ◽  
Author(s):  
L. Bjerve ◽  
O. Grøterud
Keyword(s):  
Feed Rate ◽  
Dilution Method ◽  
Salt Solutions ◽  
Small Streams ◽  
Dilution Level ◽  
Discharge Measurements ◽  
Constant Feed Rate

Water discharges in small turbulent streams are determined by injecting concentrated salt solutions at constant feed-rate and measuring the dilution level downstream by conductivity readings in situ. This new-formed method is comparable with the traditional relative salt-dilution method, as well as with other methods, with respect to accuracy. In small streams with complicated hydrodynamic structures the new-formed method seems to be most practical and reliable.

Nonisochoric Reactor with Constant Feed Rate of One Component

1993 ◽  
Vol 58 (7) ◽  
pp. 1476-1484
Author(s):  
Václav Dušek ◽  
František Skopal
Keyword(s):  
Sulfuric Acid ◽  
Acid Medium ◽  
Feed Rate ◽  
Redox System ◽  
Chemical Reactor ◽  
Constant Volume ◽  
Rate Equations ◽  
Sulfuric Acid Medium ◽  
Constant Feed Rate

For a chemical reactor with constant volume feed rate equations have been derived which describe the time dependences of concentration of the reaction components, and their approximation has been suggested. The applicability of the approximation has been verified on a model redox system Ce(IV)/V(IV) in sulfuric acid medium.

A study on the effect of cooling on microstructure and mechanical properties of friction stir-welded AA5086 aluminum butt and lap joints

2017 ◽  
Vol 233 (6) ◽  
pp. 1156-1165 ◽  
Author(s):  
Adel Sedaghati ◽  
Hamed Bouzary
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Feed Rate ◽  
Rotational Speed ◽  
Lap Joints ◽  
Tensile Behavior ◽  
Water Cooling ◽  
Friction Stir ◽  
Microstructural Behavior ◽  
Constant Feed Rate

In this paper, the effect of water cooling on mechanical properties and microstructure of AA5086 aluminum joints during friction stir welding is investigated. For doing so, the mechanical and microstructural behavior of samples welded both in air and in water was analyzed. Tests were performed involving both butt and lap welds and the results were compared. The effect of rotational speed at constant feed rate of 50 mm/min and changing rotational speed ranging from 250 to 1250 r/min was investigated. The results showed a significant change in the tensile behavior of the butt-welded specimens due to water cooling. In addition, welding was performed at constant spindle speed of 800 r/min and various traverse speeds (25 mm/min to 80 mm/min) to determine the effect of feed rate. The strength increases at first, but then decreases dramatically along with the feed rate which is due to the occurrence of a groove defect. Results showed some generally positive impacts of water cooling which are discussed in terms of tensile results, hardness distributions and microstructure analysis.

scholarly journals Drilling Parameters Analysis on In-Situ Al/B4C/Mica Hybrid Composite and an Integrated Optimization Approach Using Fuzzy Model and Non-Dominated Sorting Genetic Algorithm

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2060
Author(s):  
Palanikumar Kayaroganam ◽  
Velavan Krishnan ◽  
Elango Natarajan ◽  
Senthilkumar Natarajan ◽  
Kanesan Muthusamy
Keyword(s):  
Genetic Algorithm ◽  
Feed Rate ◽  
Rotational Speed ◽  
Metal Matrix ◽  
Thrust Force ◽  
Performance Indicator ◽  
Hybrid Composites ◽  
Input Parameter ◽  
Optimization Approach

In-situ hybrid metal matrix composites were prepared by reinforcing AA6061 aluminium alloy with 10 wt.% of boron carbide (B4C) and 0 wt.% to 6 wt.% of mica. Machinability of the hybrid aluminium metal matrix composite was assessed by conducting drilling with varying input parameters. Surface texture of the hybrid composites and morphology of drill holes were examined through scanning electron microscope images. The influence of rotational speed, feed rate and % of mica reinforcement on thrust force and torque were studied and analysed. Statistical analysis and regression analysis were conducted to understand the significance of each input parameter. Reinforcement of mica is the key performance indicator in reducing the thrust force and torque in drilling of the selected material, irrespective of other parameter settings. Thrust force is minimum at mid-speed (2000 rpm) with the lowest feed rate (25 mm/min), but torque is minimum at highest speed (3000 rpm) with lowest feed rate (25 mm/min). Multi-objective optimization through a non-dominated sorting genetic algorithm has indicated that 1840 rpm of rotational speed, 25.3 mm/min of feed rate and 5.83% of mica reinforcement are the best parameters for obtaining the lowest thrust force of 339.68 N and torque of 68.98 N.m. Validation through experimental results confirms the predicted results with a negligible error (less than 0.1%). From the analysis and investigations, it is concluded that use of Al/10 wt.% B4C/5.83 wt.% mica composite is a good choice of material that comply with European Environmental Protection Directives: 2000/53/CE-ELV for the automotive sector. The energy and production cost of the components can be very much reduced if the found optimum drill parameters are adopted in the production.

scholarly journals Long-term Total Water Storage Change from a SAtellite Water Cycle (SAWC) reconstruction over large south Asian basins

2019 ◽  
Author(s):  
Victor Pellet ◽  
Filipe Aires ◽  
Fabrice Papa ◽  
Simon Munier ◽  
Bertrand Decharme
Keyword(s):  
Water Resources ◽  
Climate Variability ◽  
Water Cycle ◽  
Water Storage ◽  
Anthropogenic Pressure ◽  
Total Water ◽  
Storage Change ◽  
Discharge Measurements

Abstract. The Total Water Storage Change (TWSC) over land is a major component of the global water cycle, with a large influence on climate variability, sea level budget and water resources availability for human life. Its first estimates at large-scale were made available with GRACE observations for the 2002–2016 period, followed since 2018 by the launch of GRACE-FO mission. In this paper, using an approach based on the water mass conservation rule, we proposed to merge satellite-based observations of precipitation and evapotranspiration along with in situ river discharge measurements to estimate TWSC over longer time periods (typically from 1980 to 2016), compatible with climate studies. We performed this task over five major Asian basins, subject to both large climate variability and strong anthropogenic pressure for water resources, and for which long term record of in situ discharge measurements are available. Our SAtellite Water Cycle (SAWC) reconstruction provides TWSC estimates very coherent in terms of seasonal and interannual variations with independent sources of information such as (1) TWSC GRACE-derived observations (over the 2002–2015 period), (2) ISBA-CTRIP model simulations (1980–2015), and (3) multi-satellite inundation extent (1993–2007). This analysis shows the advantages of the use of multiple satellite-derived data sets along with in situ data to perform hydrologically coherent reconstruction of missing water component estimate. It provides a new critical source of information for long term monitoring of TWSC and to better understand their critical role in the global and terrestrial water cycle.

scholarly journals Development and Optimization of a Manual Fed Cassava Root Chipper for Household Cassava Processors

2020 ◽  
pp. 283-295
Author(s):  
Macmanus NDUKWU ◽  
Gabriel AFAM ◽  
Nnaemeka NWAKUBA
Keyword(s):  
Moisture Content ◽  
Feed Rate ◽  
Initial Moisture Content ◽  
Throughput Capacity ◽  
Optimum Thickness ◽  
Cassava Root ◽  
Effect Of Moisture ◽  
Machine Speed ◽  
Content Range ◽  
Constant Feed Rate

A motorized, manual fed cassava root chipping machine was developed, evaluated and optimized. The objective of the research is to investigate the effect of moisture content and speed on the chipping sizes, efficiency, throughput and machine capacities. Obtained results showed that the cassava initial moisture content significantly affected the chipping size, machine capacity, throughput capacity and chipping efficiency within the tested moisture content range of 52 to 68% w.b. The machine speed also affected the chipping size, chipping efficiency, machine and throughput capacity. The average chipping size for the cassava chips at the four ranges of moisture content, speeds and constant feed rate of 89±26.6 kg h-1 ranged from 0.56 to 0.96 cm with optimum thickness 0.618 at 450 rpm and moisture content of 65.27% based on desirability factor. The average chipping efficiency ranged from 60 to 90% with an optimum value of 79.57% at 533 rpm and moisture content of 68 % while the throughput capacities of the machine ranged from 49 to118 kg/h with optimum value of 118 kg/h at a speed of 600 rpm and 68% moisture content.

Study on Surface Roughness of Milling In-Situ TiB2 Particle Reinforced Al Matrix Composites

2019 ◽  
Author(s):  
Xiao-fen Liu ◽  
Wen-hu Wang ◽  
Rui-song Jiang ◽  
Yi-feng Xiong ◽  
Kun-yang Lin ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Feed Rate ◽  
Metal Matrix ◽  
Cutting Speed ◽  
Cutting Parameters ◽  
Matrix Composites ◽  
Cutting Depth

Abstract The current state of surface roughness focuses on the 2D roughness. However, there are shortcomings in evaluating surface quality of particle reinforced metal matrix composites using 2D roughness due to the fact that the measuring direction has a vital impact on the 2D roughness value. It is therefore of great importance and significance to develop a proper criterion for measuring and evaluating the surface roughness of cutting particle reinforced metal matrix composites. In this paper, an experimental investigation was performed on the effect of cutting parameters on the surface roughness in cutting in-situ TiB2/7050Al MMCs. The 2D roughness Ra, 3D roughness Sa and Sq were comparatively studied for evaluating the machined surface quality of in-situ TiB2/7050Al MMCs. The influence of cutting parameters on the surface roughness was also analyzed. The big difference between roughness Ra measured along cutting and feed directions showed the great impact of measuring direction. Besides, surface defects such as pits, grooves, protuberances and voids were observed, which would influence 2D roughness value greatly, indicating that 3D roughness was more suitable for evaluating surface quality of cutting in-situ TiB2/7050Al MMCs. The cutting depth and feed rate were found to have the highest influence on 3D roughness while the effect of cutting speed was minimal. With increasing feed rate, cutting depth or width, the 3D roughness increased accordingly. But it decreased as cutting speed increased.

Study on hole machining for the constant feed rate of Al2O3 engineering ceramics through low-frequency axial vibration

2019 ◽  
Vol 234 (6-7) ◽  
pp. 971-979
Author(s):  
Lei Zheng ◽  
Chen Zhang ◽  
Xianglong Dong ◽  
Yong Feng ◽  
Wendong Wei ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Feed Rate ◽  
Low Frequency ◽  
Wall Surface ◽  
Axial Vibration ◽  
Drilling Force ◽  
Edge Chipping ◽  
Engineering Ceramics ◽  
Hole Machining ◽  
Constant Feed Rate

Engineering ceramics are increasingly extensively applied in the aerospace, vehicle, armor protection and other fields due to their excellent performances such as high compression strength, high hardness, low density and high protection performance. However, engineering ceramics are typical difficult-to-machine materials, especially in the hole machining under constant feed rate, which limits the promotion and application. In this study, by combining a specially developed novel thin-wall diamond trepanning bit with a low-frequency axial vibration machining, the hole machining process for the constant feed rate of Al2O3 engineering ceramics was experimentally studied and the influence of the low-frequency axial vibration process on the axial drilling force, hole-wall surface roughness and edge chipping size of holes machined was analyzed. The results showed that the low-frequency axial vibration machining obtained a lower axial drilling force and a smaller edge chipping size compared to the traditional drilling process. Moreover, both the axial drilling force and the edge chipping size declined markedly with the rise in amplitude. However, the hole-wall surface roughness presented a rising trend due to the hammering effect of vibration. The process technology proposed in this article realizes the hole machining for a constant feed rate of Al2O3 engineering ceramics and provides a reference for the engineering lot-size hole machining of engineering ceramics.

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