scholarly journals DESIGN OF DEEP-FERTILIZATION MECHANISM WITH DEFORMED GEARS AND PERFORMANCE TESTS

2021 ◽  
pp. 321-332
Author(s):  
Jinlong Feng ◽  
Shujuan Yi ◽  
Qichao Li
Keyword(s):  
Functional Relationship ◽  
Hole Size ◽  
Single Factor ◽  
Exponential Relationship ◽  
Exponential Functional ◽  
Carrier Velocity ◽  
And Performance ◽  
Pump Pressure ◽  
Central Composite ◽  
Planet Carrier

Deep-fertilization mechanism is a key part of deep-fertilization liquid fertilizer applicator. To obtain a good-performance deep-fertilization mechanism, this study developed a deep-fertilization mechanism with deformed gears and designed a deformed gear fertilization test bench. Single-factor and central composite design tests were performed with the planet carrier, spray hole size and pump pressure as the test factors, and the fertilizer amount as the test index. The results of the single-factor test showed a linear functional relationship between fertilizer amount and pump pressure, an exponential functional relationship between planet carrier velocity and fertilizer amount, and an exponential relationship between spray hole size and fertilizer amount. The rotating and perpendicular test data were analyzed and optimized using Design-Expert 8.0.5 software. The result of the optimization is: 10.5ml of fertilizer amount with pump pressure 0.36MPa, planet carrier velocity 82 r/min, and spray hole size 2 mm. The test result can meet the agronomic requirements.

Effects of Mixing Chamber Shape on Cutting Performance in Abrasive Water Jet

2013 ◽  
Vol 652-654 ◽  
pp. 2134-2139
Author(s):  
Hyo Ryeol Lee ◽  
Yong Sik Cho ◽  
Hwa Young Kim ◽  
Jung Hwan Ahn
Keyword(s):  
Surface Roughness ◽  
Cutting Speed ◽  
Water Jet ◽  
Orifice Diameter ◽  
Abrasive Water Jet ◽  
Processing Technologies ◽  
Mixing Chamber ◽  
Energy Processing ◽  
And Performance ◽  
Pump Pressure

It is well known that abrasive water jet(AWJ) was developed as a kind of high-density energy processing technologies. AWJ is used to obtain cutting quality of various materials such as metal, ceramics, glass and composite materials within a short manufacturing time because of the characteristics of heatless and noncontact processing. However, surface roughness and dimension error like round, burr, taper depend on the cutting conditions such as pump pressure, cutting speed, orifice diameter, stand off distance, abrasive flow rate and workpiece. In this paper, the effect of the shape of mixing chamber on surface quality is studied. Parabolic mixing chamber is proposed and performance is compared to that of cylindrical mixing chamber by experiment. The surface roughness was improve 0.15㎛ to 2.29㎛ and the taper angle was improve 0.0716° to 0.143° by parabolic mixing chamber.

Evaluation of Substances Released from Hydrothermal Pretreated Municipal Sludge and Performance of Hydrogen Production by the Corresponding Supernatant

2013 ◽  
Vol 726-731 ◽  
pp. 2468-2475 ◽  
Author(s):  
Li Yu ◽  
Cheng Lin Sun ◽  
Yong Hui Yu ◽  
Wen Tian Jiang
Keyword(s):  
Hydrogen Production ◽  
Hydrogen Yield ◽  
Air Oxidation ◽  
Wet Air Oxidation ◽  
Production Potential ◽  
Reaction Conditions ◽  
Stirring Rate ◽  
And Performance ◽  
Temperature Time ◽  
Central Composite

Response surface methodology (RSM) with central composite design was adopted to investigate the optimum condition for carbohydrate released from hydrothermal pretreated sludge in an autoclave used for WAO (wet air oxidation). Temperature, time and stirring rate were chosen as variables. The maximum carbohydrate release (1356.8 mg/L) was estimated at the temperature of 161.2 °C, the time of 48 min and the stirring rate of 661 r/min. This statistical method could precisely optimize reaction conditions and predict the experimental data. Only 11.2 mL methane was generated with little hydrogen production of raw sludge. In contrast, hydrogen production potential of 25 mL was reached by using supernatant as substrate with a COD removal of 78.14%. Hydrogen yield was increased from 0.13 mL/g-VS (raw sludge) to 13.16 mL/g-VS (supernatant of pretreated sludge).

scholarly journals Strategic Priorities, Management Competencies, and Performance of the Divisions of Schools in Negros Island, Philippines

2021 ◽  
Vol 4 (4) ◽  
pp. 82-90
Author(s):  
Mary Ann M. Temprosa
Keyword(s):  
Good Governance ◽  
Department Of Education ◽  
Quality Education ◽  
Single Factor ◽  
Management Competencies ◽  
Statistical Tools ◽  
Significant Difference ◽  
Single Factor Analysis ◽  
And Performance ◽  
Negros Island

Good governance is a requisite in achieving quality education and lifelong learning. This combined descriptive, comparative, and correlative study looked into the strategic priorities, management competencies, and performance of the 16 divisions of schools in the Department of Education in Negros Island, Philippines. The statistical tools used were percentage and mean to determine their strategic priorities, management competencies, and performance based on the study's indicators; single-factor analysis of variance to find out any significant difference in their strategic priorities and management competencies;  and Spearman rho to examine the coefficient of correlation between their strategic priorities and management competencies, their strategic priorities and performance, and their management competencies and performance. The study found no significant difference between the divisions of schools’ strategic priorities and management competencies, and no significant relationship between these variables and between these variables and their performance.    

scholarly journals Study of the Degradation of Trimethoprim Using Photo-Fenton Oxidation Technology

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 207 ◽  
Author(s):  
Qi Wang ◽  
Wenjing Pang ◽  
Yingdan Mao ◽  
Quan Sun ◽  
Pengfei Zhang ◽  
...  
Keyword(s):  
High Performance ◽  
Degradation Rate ◽  
Fenton Oxidation ◽  
Design Experiment ◽  
H2o2 Concentration ◽  
Optimal Conditions ◽  
Single Factor ◽  
Experimental Conditions ◽  
Oxidation Technology ◽  
Central Composite

Trimethoprim is one of the representative drugs within the pharmaceutical and personal care products (PPCPs) group. The photo-Fenton oxidation technology was used to degrade trimethoprim in wastewater and the extent of degradation was analyzed by using high-performance liquid chromatography, then experimentally obtained the optimal conditions. Analysis of the experimental data showed that, under the single-factor experimental conditions, the optimal conditions for degradation were a pH of 4, an H2O2 concentration of 3.0 mmol/L, an FeSO4 concentration of 0.06 mmol/L, an initial trimethoprim concentration of 0.0689 mmol/L, and an ultraviolet (UV) intensity (UVA) of 12 mW/cm2. The interaction of pH and the concentration of H2O2 and Fe2+ have been further explored, it was obtained the following response surface results through the central composite design experiment: pH = 4.56, H2O2 concentration = 0.09 mmol/L, and Fe2+ concentration = 0.09 mmol/L. Under these conditions, it can be obtained a degradation rate of 99.95% after 6 min. There were similar results for three sets of parallel experiments, indicating that these simulation conditions were feasible.

scholarly journals A psychometric approach to supervisory competency assessment

2003 ◽  
Vol 29 (3) ◽  
Author(s):  
A. Vorster ◽  
G. Roodt
Keyword(s):  
South Africa ◽  
United Kingdom ◽  
Competency Assessment ◽  
Single Factor ◽  
Production Engineering ◽  
Internal Reliability ◽  
The United Kingdom ◽  
Unit Standards ◽  
And Performance ◽  
F Statistics

The primary purpose of this study was to evaluate the possibility of using a psychometric approach for assessing supervisory competencies relevant to the mining and refining environment. The competency questionnaire was developed using supervisory roles and registered supervisory unit standards from the United Kingdom (UK), as no registered unit standards exist in South Africa. Twenty-four supervisors from three departments (Production, Engineering and Laboratory) were evaluated by 125 raters; besides by themselves, also by their managers, peers, customers and their sub-ordinates. Based on difference scores derived from the Importance and Performance scales, a single factor was extracted with an internal reliability of 0,965. No statistical significant differences were obtained (ANOVA’s, t-test and F-statistics) between groups based on biographical variables or between rater groups. The findings and their implications are further discussed. Opsomming Die primêre doel van die studie was om die moontlikheid vir die gebruik van ’n psigometriese benadering tot toesighouerbevoegdheidsbeoordeling, te evalueer. Die bevoegdheidsvraelys is ontwikkel deur gebruik te maak van toesighouersrolle en geregistreerde toesighouerseenheidstandaarde van die Verenigde Koningkryk, as gevolg van ‘n gebrek aan bestaande eenheidstandaarde in Suid-Afrika. Vier-en-twintig toesighouers van drie departemente (Produksie, Ingenieurswese en Laboratorium) is deur 125 beoordelaars geëvalueer; buiten deur hulself, ook deur hul bestuurders, kollegas, kliënte en hul ondergeskiktes. ’n Enkele faktor, met ’n betroubaarheid van 0,965, gebaseer op die verskiltellings van die Prestasie- en Belangrikheidskaal, is onttrek. Geen beduidende verskille (ANOVA’s, t-toetse en F-statistiek) kon tussen groepe gebaseer op biografiese veranderlikes en die onderskeie beoordelaarsgroepe gevind word nie. Hierdie bevindinge en die implikasies daarvan word verder bespreek.

scholarly journals Comparison of the Accuracy and Performance of Different Numbers of Classes in Discretised Solution Method for Population Balance Model

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Zhenliang Li ◽  
Zhien Zhou ◽  
Sheng Zhang ◽  
Hongqiang Jiang
Keyword(s):  
Fibonacci Sequence ◽  
Population Balance ◽  
Balance Model ◽  
Population Balance Model ◽  
Collision Efficiency ◽  
Exponential Relationship ◽  
Parameter Ratio ◽  
And Performance ◽  
Number Of Classes ◽  
Geometric Grids

One way of solving population balance model (PBM) in a time efficient way is by means of discretisation of the population property of interest. A computational grid, for example, vi+1=kvi (vi is the volume of particle in class i), could be used to classify the particles in discretisation techniques. However, there are still disagreements in the appropriate number of classes divided by the grids. In this study, the different numbers of classes for solving PBM were compared in terms of accuracy and performance to describe the particle size distribution (PSD) from the flocculation of activated sludge. It is found that the simulated PSDs are similar to the experimental data for all the geometric grids (vi+1:vi≤2), and there is no obvious difference among the values of calibrated parameter, ratio of breakage rate coefficient and collision efficiency, for each velocity gradient. However, the simulation results with less error could be obtained with larger number of classes, and more computational times, which show exponential relationship with the number of classes, are needed. Considering numerical accuracy and efficiency, the classes 35 or a geometric grid with factor 1.6, aligning with the Fibonacci sequence (vi+vi-1≈vi+1), is recommended for the particles in the size range of 5.5~1086 μm.

scholarly journals Development and Performance Evaluation of a Double Barrel Cassava Grating Machine

2020 ◽  
pp. 133-140
Author(s):  
Okonkwo Ugochukwu Chuka ◽  
Okafor Christian Emeka ◽  
Ihueze Christopher Chukwutoo
Keyword(s):  
Performance Evaluation ◽  
Feed Rate ◽  
Optimum Operating ◽  
Optimum Operating Condition ◽  
Operating Condition ◽  
Average Mass ◽  
Abrasive Surface ◽  
And Performance ◽  
Double Discharge ◽  
Central Composite

In this study, a double barrel cassava grating machine with double discharge outlet has been developed and its performance evaluated and optimized. The machine was designed to ensure very high throughput, easy decoupling and coupling and reduction in grating time. The performance evaluation of the grating machine was carried out using Design Expert Software. A central composite rotatable design of response surface methodology (RSM) was adopted in determining the optimum operating condition of the machine. The optimum operating condition obtained from the machine shows an optimum abrasive surface hole size of 6mm, feed rate of 11.8kg/min and an optimum feed rate of 20.16 kg/min; a through put capacity of 730.8kg/hr. The average mass loss, partially grated and completely grated were found to be 1.43kg, 1.48kg and 22.09kg, respectively for 25kg sample; which indicates effective grating and waste was drastically reduced with an average grating efficiency of 86.23%.

Application of a New Pressure Intensifier Using Oil Hammer to Pressure Control of a Hydraulic Cylinder

1989 ◽  
Vol 111 (2) ◽  
pp. 322-328 ◽  
Author(s):  
K. Suzuki
Keyword(s):  
Pressure Rise ◽  
Pressure Control ◽  
Hydraulic Cylinder ◽  
Control Device ◽  
Hydraulic Pressure ◽  
New Type ◽  
And Performance ◽  
Pump Pressure

In a previous paper the author proposed to actively utilize the pressure rise phenomenon of an oil hammer and a new type of a hydraulic pressure intensifier using oil hammers. In this paper, one application of this intensifier is tested, where the intensifier is connected to a hydraulic cylinder. The hydraulic cylinder is driven by pressure which is several times higher than the original pump pressure. In addition, a method to use this system as a pressure control device is proposed and its principle and performance is clarified.

Research on Expansion Alloy Grain Growth Tendency

2011 ◽  
Vol 148-149 ◽  
pp. 232-235
Author(s):  
Feng Yan ◽  
Ke Qiang Yu
Keyword(s):  
Heat Treatment ◽  
Integrated Circuit ◽  
Manufacturing Industry ◽  
Optimization Method ◽  
Recrystallization Temperature ◽  
Coarse Grain ◽  
Single Factor ◽  
Grain Sizes ◽  
And Performance ◽  
Sealing Glass

4J29 is a typical of expansion alloy and used as sealing glass material and structure material in transistors, integrated circuit devices manufacturing industry. This article adopts heat-treatment experiments and single factor optimization method to study the relationships of recrystallization temperature, beforehand deformation and grain sizes on 4J29 alloy; then discusses the reason why the coarse grain phenomena appear and gives technological measures to improve the quality and performance of workpiece

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