scholarly journals Comparison of Two Locally Made Motorized Plantain Slicers

2021 ◽  
Vol 06 (03) ◽  
Author(s):  
Adedipe J.O ◽  
Keyword(s):  
Power Input ◽  
Equal Length ◽  
Throughput Capacity ◽  
Maximum Efficiency ◽  
Small Scale ◽  
Motor Speed ◽  
Average Throughput ◽  
Evaluation Result ◽  
Average Efficiency

This study focused on comparing two locally designed plantain slicers in other to economically and productively advice small scale chips – producers. The two selected slicing machines were horizontally inclined slicer (HIS) and vertically inclined slicer (VIS). These slicers were carefully chosen and it was ensured they had same power input, motor speed, and slicing blade of equal length. Evaluation result showed that the highest throughput capacity for HIS was 51.16 kg/hr and had an average throughput capacity of 50.10 kg/hr while the highest throughput capacity for VIS was 45.90 kg/hr and had an average throughput capacity of 45.34 kg/hr. The results of the slicing efficiencies showed that a maximum efficiency of 100 %, but had an average efficiency value of 92.84 %, while VIS had a maximum efficiency value of 87 % and an average efficiency value of 83.25 %. From the results of the throughput capacity and the efficiency of the two slicers, it can be concluded that HIS performed better and faster than VIS and is considered the better both economically and productively.

scholarly journals Performance Evaluation of a Small-Scale Mechanical Fish Feeder

2021 ◽  
Vol 6 (5) ◽  
pp. 168-170
Author(s):  
S. A. Fasoyin ◽  
W. A. Akinfiresoye ◽  
L. A. S. Agbetoye ◽  
L. A. Olutayo ◽  
O. Adetuyi
Keyword(s):  
Performance Evaluation ◽  
Throughput Capacity ◽  
Screw Conveyor ◽  
Small Scale ◽  
Fish Feed ◽  
Motor Speed ◽  
Reducing Gear ◽  
Constant Moisture Content ◽  
Machine Speed ◽  
The Cost

The performance evaluation of an existing mechanical fish feeder was carried out. Floating feeds of sizes 2 mm, 4 mm, and 6 mm at constant moisture content of 13 % were fed into the feeder. The feeder was powered by a 3-phase, 1.5 kW reducing gear electric motor at speed 40 rpm, 50 rpm, 60 rpm, 70 rpm and 80 rpm machine. It was observed that the horizontal screw conveyor effectively transported the material from the hopper to the discharged point. The results obtained from the tests showed an optimal performance of the machine at speed 50 rpm with dispensing efficiency of 93.1 % for 2 mm feed size, while the throughput was 75.76 kg/h at motor speed of 80 rpm also for the 2 mm fish feed size. The ANOVA at p ≤ 0.05 showed that machine speed has significant effect on its dispensing efficiency and the throughput capacity. The cost of production of the mechanical fish feeder was ₦262,300 which made it affordable for young entrepreneurs.

scholarly journals Ethnic face categorization by Russians and Tuvinians in discrimination tasks

2019 ◽  
Vol 12 (4) ◽  
pp. 120-141
Author(s):  
V.N. Kharitonov ◽  
I.A. Basyul ◽  
K.I. Ananyeva ◽  
N.O. Tovuu
Keyword(s):  
Task Performance ◽  
Ethnic Groups ◽  
Communication Skills ◽  
Dual Task ◽  
Maximum Efficiency ◽  
Small Scale ◽  
Isolated Populations ◽  
Face Categorization ◽  
Transition Series ◽  
Large Groups

The opposite tendencies towards blurring the boundaries of compact living of ethnic groups and of relocation of large groups of strangers into the territories of compact residence of local groups generate a number of specific phenomena connected with the inter-group perception. We conducted a comparative study of perception and communication of transition series of “ethnic faces” among two small-scale isolated populations and representatives of the corresponding ethnic groups in multi-ethnic cities. The participants were to solve two discrimination task, one individually, the AB=X task, the other one, the dual “same-different” task, in dyads. For all samples of subjects, of In the AB=X task, the maximum discrimination efficiency was recorded for the same no. 2—3 pair of transition images series This may indicate that all subjects relied on the morphological features stimulus faces than on anything else. Also a tendency is observed toward similarity in the dynamics of efficiency of task performance in different groups of subjects, with the exception of the sample of Russians from the metropolis. At the same time, in the dyadic experiment, subjects from megacities demonstrate different trends in terms of the maximum efficiency of task performance. The sample of Russian subjects from Moscow demonstrates a significantly smaller decrease in efficiency when approaching the edges of the transitional series of stimulus images in the AB=X task, but not in the dual task. This is probably due to different nature of the tasks, i.e. one may easily suppose a more developed ability to perceptually discriminate between ethnic faces resulting from their greater variety in the environment, as in Moscow megacity, whereas it does not seem reasonable to suppose difference in communication skills required to perform the dual task across the samples.

Small Scale Supercritical CO2 Radial Inflow Turbine Meanline Design Considerations

2018 ◽  
Author(s):  
Tina Unglaube ◽  
Hsiao-Wei D. Chiang
Keyword(s):  
High Velocity ◽  
Gas Turbines ◽  
Velocity Ratio ◽  
Maximum Efficiency ◽  
Design Parameters ◽  
Working Fluid ◽  
Small Scale ◽  
Optimum Velocity ◽  
Set Up ◽  
Very High

In recent years closed loop supercritical carbon dioxide Brayton cycles have drawn the attention of many researchers as they are characterized by a higher theoretic efficiency and smaller turbomachinery size compared to the conventional steam Rankine cycle for power generation. Currently, first prototypes of this emerging technology are under development and thus small scale sCO2 turbomachinery needs to be developed. However, the design of sCO2 turbines faces several new challenges, such as the very high rotational speed and the high power density. Thus, the eligibility of well-established radial inflow gas turbine design principles has to be reviewed regarding their suitability for sCO2 turbines. Therefore, this work reviews different suggestion for optimum velocity ratios for gas turbines and aims to re-establish it for sCO2 turbines. A mean line design procedure is developed to obtain the geometric dimensions for small scale sCO2 radial inflow turbines. By varying the specific speed and the velocity ratio, different turbine configurations are set up. They are compared numerically by means of CFD analysis to conclude on optimum design parameters with regard to maximum total-to-static efficiency. Six sets of simulations with different specific speeds between 0.15 and 0.52 are set up. Higher specific speeds could not be analyzed, as they require very high rotational speeds (more than 140k RPM) for small scale sCO2 turbines (up to 150kWe). For each set of simulations, the velocity ratio that effectuates maximum efficiency is identified and compared to the optimum parameters recommended for radial inflow turbines using subcritical air as the working fluid. It is found that the values for optimum velocity ratios suggested by Rohlik (1968) are rather far away from the optimum values indicated by the conducted simulations. However, the optimum values suggested by Aungier (2005), although also established for subcritical gas turbines, show an approximate agreement with the simulation results for sCO2 turbines. Though, this agreement should be studied for a wider range of specific speeds and a finer resolution of velocity ratios. Furthermore, for high specific speeds in combination with high velocity ratios, the pressure drop of the designed turbines is too high, so that the outlet pressure is beyond the critical point. For low specific speeds in combination with low velocity ratios, the power output of the designed turbines becomes very small. Geometrically, turbines with low specific speeds and high velocity ratios are characterized by very small blade heights, turbines with high specific speeds and small velocity ratios by very small diameters.

Low cost Real Time Centralized Speed Control of DC Motor Using Lab view -NI USB 6008

2016 ◽  
Vol 7 (3) ◽  
pp. 656 ◽  
Author(s):  
C. Bharatiraj ◽  
JL Munda ◽  
Ishan Vaghasia ◽  
Rajesh Valiveti ◽  
P. Manasa
Keyword(s):  
Virtual Instrument ◽  
Low Cost ◽  
Speed Control ◽  
Dc Motor ◽  
Industrial Applications ◽  
Laboratory Model ◽  
Small Scale ◽  
Motor Speed ◽  
Software Environment ◽  
Lab View

The DC motors an outstanding portion of apparatus in automotive and automation industrial applications requiring variable speed and load characteristics due to its ease of controllability. Creating an interface control system for multi DC motor drive operations with centralized speed control, from small-scale models to large industrial applications much demand. By using Lab VIEW (laboratory virtual instrument engineering workbench) as the motor controller, can control a DC motor for multiple purposes using single software environment. The aim of this paper is to propose the centralized speed control of DC motor using Lab VIEW. Here, the Lab VIEW is used for simulating the motor, whereas the input armature voltage of the DC motor is controlled using a virtual Knob in Lab VIEW software. The hardware part of the system (DC motor) and the software (in personal computer) are interfaced using a data acquisition card (DAQ) -Model PCI- 6024E. The voltage and Speed response is obtained using LABVIEW software. Using this software, group of motors’ speed can be controlled from different location using remote telemetry. The propose work also focuses on controlling the speed of the individual DC motor using PWM scheme (Duty cycle based Square wave generation) and DAQ. Help of the DAQ along with Lab VIEW front panel window, the DC motor speed and directions can be change easily in remote way. In order to test the proposed system the laboratory model for an 80W DC motor group (multi drive) is developed for different angular displacements and directions of the motor. The simulation model and experimental results conforms the advantages and robustness of the proposed centralized speed control.

Preliminary Design of Small-Scale Supercritical CO2 Radial Inflow Turbines

2020 ◽  
Vol 142 (2) ◽  
Author(s):  
Tina Unglaube ◽  
Hsiao-Wei D. Chiang
Keyword(s):  
Optimum Design ◽  
Supercritical Co2 ◽  
Velocity Ratio ◽  
Design Procedure ◽  
Expansion Ratio ◽  
Maximum Efficiency ◽  
Design Parameters ◽  
Small Scale ◽  
Preliminary Design ◽  
Line Design

Abstract In recent years, supercritical CO2 (sCO2) Brayton cycles have drawn the attention of researchers due to their high cycle efficiencies, compact turbomachinery, and environmental friendliness. For small-scale cycles, radial inflow turbines (RIT) are the prevailing choice and one of the key components. A mean line design procedure for sCO2 RIT is developed and design space exploration conducted for a 100 kW-class turbine for a low-temperature waste-heat utilization sCO2 Brayton cycle. By varying the two design parameters, specific speed and velocity ratio, different turbine configurations are setup and compared numerically by means of computational fluid dynamics (CFD) simulations. Results are analyzed to conclude on optimum design parameters with regard to turbine efficiency and expansion ratio. Specific speeds between 0.2 and 0.5 are recommended for sCO2 RIT with small though flow (3 kg/s). The higher the velocity ratio, the bigger the turbine expansion ratio. Pairs of optimum design parameters that effectuate maximum efficiency are identified, with smaller velocity ratios prevailing for smaller specific speeds. The turbine simulation results for sCO2 are compared to well-established recommendations for the design of RIT from literature, such as the Balje diagram. It is concluded that for the design of sCO2 RITs, the same principles can be used as for those for air turbines. By achieving total-to-static stage and rotor efficiencies of 84% and 86%, respectively, the developed mean line design procedure has proven to be an effective and easily applicable tool for the preliminary design of small-scale sCO2 RIT.

scholarly journals Longitudinal contrast in turbulence along a  ∼ 19° S section in the Pacific and its consequences for biogeochemical fluxes

2018 ◽  
Vol 15 (24) ◽  
pp. 7485-7504 ◽  
Author(s):  
Pascale Bouruet-Aubertot ◽  
Yannis Cuypers ◽  
Andrea Doglioli ◽  
Mathieu Caffin ◽  
Christophe Yohia ◽  
...  
Keyword(s):  
Surface Layer ◽  
Power Input ◽  
Small Scale ◽  
Vertical Diffusion ◽  
The West ◽  
Photic Layer ◽  
Time Space ◽  
Vertical Scale ◽  
Long Duration ◽  
Diffusive Fluxes

Abstract. Microstructure measurements were performed along the OUTPACE longitudinal transect in the tropical Pacific (Moutin and Bonnet, 2015). Small-scale dynamics and turbulence in the first 800 m surface layer were characterized based on hydrographic and current measurements at fine vertical scale and turbulence measurements at centimeter scale using a vertical microstructure profiler. The possible impact of turbulence on biogeochemical budgets in the surface layer was also addressed in this region of increasing oligotrophy to the east. The dissipation rate of turbulent kinetic energy, ϵ, showed an interesting contrast along the longitudinal transect with stronger turbulence in the west, i.e., the Melanesian Archipelago, compared to the east, within the South Pacific Subtropical Gyre, with a variation of ϵ by a factor of 3 within [100–500 m]. The layer with enhanced turbulence decreased in vertical extent travelling eastward. This spatial pattern was correlated with the energy level of the internal wave field, higher in the west compared to the east. The difference in wave energy mostly resulted from enhanced wind power input into inertial motions in the west. Moreover, three long-duration stations were sampled along the cruise transect, each over three inertial periods. The analysis from the western long-duration station gave evidence of an energetic baroclinic near-inertial wave that was responsible for the enhanced ϵ, observed within a 50–250 m layer, with a value of 8×10-9 W kg−1, about 8 times larger than at the eastern long-duration stations. Averaged nitrate turbulent diffusive fluxes in a 100 m layer below the top of the nitracline were about twice larger west of 170∘ W due to the higher vertical diffusion coefficient. In the photic layer, the depth-averaged nitrate turbulent diffusive flux strongly decreased eastward, with an averaged value of 11 µmolm-2d-1 west of 170∘ W compared with the 3 µmolm-2d-1 averaged value east of 170∘ W. Contrastingly, phosphate turbulent diffusive fluxes were significantly larger in the photic layer. This input may have an important role in sustaining the development of N2-fixing organisms that were shown to be the main primary contributors to the biological pump in the area. The time–space intermittency of mixing events, intrinsic to turbulence, was underlined, but its consequences for micro-organisms would deserve a dedicated study.

scholarly journals PENGENDALIAN KECEPATAN MOTOR DC DENGAN METODA FUZZY LOGIC BERBASIS MIKROKONTROLLER

2018 ◽  
Vol 1 (2) ◽  
pp. 1-12
Author(s):  
Nasrul Harun
Keyword(s):  
Fuzzy Logic ◽  
Pulse Width ◽  
High Speed ◽  
Pulse Width Modulation ◽  
Control Process ◽  
Dc Motor ◽  
Small Scale ◽  
Motor Speed ◽  
Fuzzy Logic Method ◽  
Logic Method

The Technology and information development involve production process in industries using microcontroller as a brain in control process. The number  of control process with microcontroller using Fuzzy Logic method to get the function as is needed. Motors DC are used in some  equipment as a driver, not only in small scale but also in huge scale. It used in low or high speed too. The way of controlled chosen depend on the function of DC motor movement. The another method is Pulse Width Modulation (PWM). This is an effective method to controlled DC motor. This method produces square pulses which have specific comparison between high pulse and low pulse. It is usual scale from 0% to 100%. In this research, both Fuzzy Logic method and Pulse Width Modulation (PWM) method base of microcontroller ATMega 8535, both are integrated to control lthe  DC motor speed.

scholarly journals Construction and Evaluation of a Vertical Motorized Feed Mixer

2021 ◽  
Vol 1 (1) ◽  
pp. 27-41
Author(s):  
Adedeji M. A. ◽  
Adegboye T. A. ◽  
Adesina I. K. ◽  
Ajayi O. O. ◽  
Azeez N. A.
Keyword(s):  
Rotational Motion ◽  
Mixing Time ◽  
Throughput Capacity ◽  
Small Scale ◽  
Poultry Production ◽  
Test Results ◽  
Base Materials ◽  
Mixing Chamber ◽  
Mixed Material ◽  
Small Scale Farmers

In order to reduce the overall cost of poultry production by small scale farmers, a motorized feed mixer was modified, fabricated and evaluated. The mixer consists of an outer drum, an inner mixing chamber and an auger. All these components were vertically oriented for mixing operation. There was a hopper located at the base of the mixer for loading the materials and a chute for the discharging of mixed products. It was modified to work through a central rotating auger fixed on a shaft that carries a pulley of diameter 185 mm. The rotational motion was transmitted from a motor through a V-belt to the pulley shaft. A 5-0 hp electric motor with 1440 rpm was used to drive the machine. Mixing was achieved as the auger conveyed the feed materials from the bottom to the top, in a continuous rotational motion. The mixer was evaluated using a whole corn kernel (WCK) at 15.35 % (d.b) and small pieces of coloured paper (CP) of 5x5 mm² as tracers in ground maize as base materials. The auger pitch was reduced from 90.0 mm to 85.0 mm to increase the number of pitches from 10 to 12. This modification increased the throughput capacity of the mixer from 50.0 kg to 70.0 kg. The mixed material was delivered through the delivery chute after mixing. Mixing time values evaluated were 2.0, 4.0, 6.0, 8.0 and 10.0 mins. The test results showed that maximum mixing occurred at 6.0 mins for coloured paper and 8.0 mins for whole kernel corn.

Sign in / Sign up

Export Citation Format

Share Document