scholarly journals PENGARUH MODIFIKASI BURITAN SPEED BOAT TERUBUK EXPRESS 6 TERHADAP KECEPATAN KAPAL

2018 ◽  
Vol 8 (2) ◽  
pp. 297 ◽  
Author(s):  
Edy Haryanto
Keyword(s):  
Diesel Fuel ◽  
Input Data ◽  
Field Survey ◽  
B Value ◽  
Maximum Speed ◽  
Total Resistance ◽  
Sea Transportation ◽  
Before And After ◽  
Shape Changes ◽  
Boat Speed

Speedboat Terubuk Express is a fast ship that is used as a means of sea transportation to carry passengers with a capacity of 60 people. Because it continues to experience losses, currently the Terubuk Express speedboat is modified by adding capacity and replacing the main drive engine which previously used an outboard engine with 4 x 200 horse power replaced with an internal engine that uses diesel fuel with power 1140 kilowatt. This study aims to determine the effect of stern shape changes and interaction total resistance before and after being modified on the hull to the speed of the ship.In this study several stages were carried out, namely a field survey to obtain the effect of size addition, making a model using Maxsurf 13.0 software, input data and running simulations using Hullspeed 13.01 then analyzing the results which included obstacles and speed.Based on the results of the analysis and calculations showed that the change in stern shape on the express speed boat speed caused L / B to increase by 1.2%, an increase in the comparison of the L / B value could affect the ability of the boat's motion and stability. The total resistance of the ship increased by 1.05% which at a speed of 35 knots before the change in total resistance was 33.5 kN while after the change in the total resistance became 35, 1 kN. Changes to the installed power engine can give a maximum speed of 49 knots with a total barrier of 47.5 kN. Increased speed greatly affects the engine seat and the strength of construction and the location of the longitudinal of bouyancy.

The performance and emission characteristics of emulsified fuel in a direct injection diesel engine

2007 ◽  
Vol 221 (7) ◽  
pp. 893-900 ◽  
Author(s):  
M P Ashok ◽  
C G Saravanan
Keyword(s):  
Diesel Engine ◽  
Diesel Fuel ◽  
Diesel Engines ◽  
Injection Pressure ◽  
Alternative Fuel ◽  
Experimental Investigations ◽  
Maximum Speed ◽  
Power Sources ◽  
Performance And Emission ◽  
Emulsified Fuel

Diesel engines are employed as the major propulsion power sources because of their simple, robust structure and high fuel economy. It is expected that diesel engines will be widely used in the foreseeable future. However, an increase in the use of diesel engines causes a shortage of fossil fuel and results in a greater degree of pollution. To regulate the above, identifying an alternative fuel to the diesel engine with less pollution is essential. Ethanol–diesel emulsion is one such method, used for the preparation of an alternative fuel for the diesel engine. Experimental investigations were carried out to compare the performance of diesel fuel with different ratios 50D: 50E (50 per cent diesel No: 2: 50 per cent ethanol –100 per cent proof) and 60D: 40E emulsified fuels. In the next phase, experiments were conducted for the selected emulsified fuel ratio 50D: 50E for different high injection pressures and the results are compared. The results show that for the emulsified fuel ratios, there is a marginal increase in torque, power, NO x, emissions, and decreasing values of carbon monoxide (CO), sulphur dioxide (SO2) emissions at the maximum speed conditions, compared with diesel fuel. Also, it is found that an increase in injection pressure of the engine running with emulsified fuel decreases CO and smoke emissions especially between 1500 to 2000 r/min with respect to the diesel fuel.

scholarly journals Effects of Acupuncture on Explosive Force Production by the Healthy Female Shoulder Joint

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
I-Lin Wang ◽  
Yi-Ming Chen ◽  
Jun Wang ◽  
Rui Hu ◽  
Ke-Ke Zhang ◽  
...  
Keyword(s):  
Shoulder Joint ◽  
Force Production ◽  
Maximum Speed ◽  
Maximum Torque ◽  
Shoulder Muscles ◽  
Potentiation Effect ◽  
Average Maximum ◽  
Significant Difference ◽  
Before And After ◽  
Explosive Force

Background. Acupuncture is often used to treat chronic conditions, such as pain. In recent years, given the importance of the explosive forces generated by shoulder muscles for the completion of motor tasks, studies in which nerves were stimulated through acupuncture to increase the explosive forces were conducted. This study explored the effect of acupuncture on explosive force production by the muscles of the female shoulder joint. Methods. Eighteen healthy women underwent shoulder adduction (Add), abduction (Abd), flexion (Flex), and extension (Ext) tests with an isokinetic measurement system. Acupuncture was used to stimulate the Zhongfu (LU1), Tianfu (LI3), Xiabai (LU4), Binao (LI14), Naohui (SJ13), Jianliao (SJ14), and Xiaoluo (SJ12) points, and electromyography (EMG) signals were recorded before and after acupuncture. Results. After acupuncture, there was a significant difference in the average maximum work, the average maximum power, the average maximum speed, the total work in Add/Abd and Flex/Ext, the EMG signals, and the stiffness of the muscles in Abd and Ext ( P < 0.05 ). There were no significant differences in the average maximum torque in Abd or Flex. Conclusion. Based on the results, there may be a significant correlation between the manipulation of different acupoints by acupuncture and the average maximum torque and stiffness. Acupuncture may stimulate nerves to activate muscles and induce a postactivation potentiation effect that improves explosive force production. Therefore, acupuncture as an auxiliary tool may increase the explosive forces generated by acupoint-related muscles by stimulating nerves.

A survey of a low-density koala population in a major reserve system, near Sydney, New South Wales..

2001 ◽  
Vol 23 (2) ◽  
pp. 135 ◽  
Author(s):  
A Curtin ◽  
D Lunney ◽  
A Matthews
Keyword(s):  
National Park ◽  
Field Survey ◽  
New South ◽  
Specific Information ◽  
Vegetation Types ◽  
Field Surveys ◽  
South Wales ◽  
Before And After ◽  
Recreation Area ◽  
Reserve System

cinereus) in Yengo National Park and Parr State Recreation Area, which together form a major reserve system where P. cinereus were known to be scarce. The first, a community survey which was distributed to 823 residences adjoining the reserves, yielded 139 responses. Of these, 31 responses provided information that allowed 26 P. cinereus locality records to be verified. A further eight P. cinereus locality records were obtained from interviews with neighbours. Most records were road-based. The second, a field survey based on scat searches, produced an additional 13 P. cinereus localities. P. cinereus scats were found under 11 tree species. Eucalyptus punctata was most frequently recorded with scats of those that were adequately sampled. A range of vegetation types and both ridges and gullies were used by P. cinereus. During field surveys, P. cinereus was found to be sparse and occurring throughout much of the survey area, concentrated in the eastern, southern and central parts of the reserve system. Both methods identified P. cinereus to be present before and after the extensive fires of January 1994, which burnt 60 % of the area. An appraisal of the methods revealed that they are complementary. The survey of residents provided recent and historical information and an indication of initial search areas for P. cinereus. The field survey yielded specific information about local P. cinereus habitat. The combination increased the number of P. cinereus records for the area more than four-fold. This study has provided the reserve managers with a clearer picture of the location of the local P. cinereus population.

Low-frequency respiratory mechanical impedance in the rat

1987 ◽  
Vol 63 (1) ◽  
pp. 36-43 ◽  
Author(s):  
Z. Hantos ◽  
B. Daroczy ◽  
B. Suki ◽  
S. Nagy
Keyword(s):  
Frequency Dependence ◽  
Chest Wall ◽  
Low Frequency ◽  
Mechanical Impedance ◽  
Total Resistance ◽  
Low Frequencies ◽  
Chest Wall Compliance ◽  
Before And After ◽  
Airway Opening ◽  
Wall Compliance

modified forced oscillatory technique was used to determine the respiratory mechanical impedances in anesthetized, paralyzed rats between 0.25 and 10 Hz. From the total respiratory (Zrs) and pulmonary impedance (ZL), measured with pseudorandom oscillations applied at the airway opening before and after thoracotomy, respectively, the chest wall impedance (ZW) was calculated as ZW = Zrs - ZL. The pulmonary (RL) and chest wall resistances were both markedly frequency dependent: between 0.25 and 2 Hz they contributed equally to the total resistance falling from 81.4 +/- 18.3 (SD) at 0.25 Hz to 27.1 +/- 1.7 kPa.l–1 X s at 2 Hz. The pulmonary compliance (CL) decreased mildly, from 2.78 +/- 0.44 at 0.25 Hz to 2.36 +/- 0.39 ml/kPa at 2 Hz, and then increased at higher frequencies, whereas the chest wall compliance declined monotonously from 4.19 +/- 0.88 at 0.25 Hz to 1.93 +/- 0.14 ml/kPa at 10 Hz. Although the frequency dependence of ZW can be interpreted on the basis of parallel inhomogeneities alone, the sharp fall in RL together with the relatively constant CL suggests that at low frequencies significant losses are imposed by the non-Newtonian resistive properties of the lung tissue.

A method of editing time series observations

Geophysics ◽  
1984 ◽  
Vol 49 (5) ◽  
pp. 521-524 ◽  
Author(s):  
John Halpenny
Keyword(s):  
Time Series ◽  
Kalman Filter ◽  
Input Data ◽  
Random Noise ◽  
Data Value ◽  
Data Gaps ◽  
Before And After ◽  
Noise Data ◽  
Fixed Delay ◽  
Time Point

Data from automatic recording systems often require editing and filtering before they are suitable for computer analysis. The procedure described in this paper produces edited values at regular intervals from input data containing random noise, data gaps, and sudden steps or resets. It uses a Kalman filter with a fixed delay time to estimate the most probable data value at any time, based on information both before and after the time point. Isolated portions of a bad record can be recognized and removed, and steps or offsets are identified and measured. An example is shown of clean output produced from input which suffers from a variety of instrumental problems.

Evaluation of health risks from a buried mass of diesel fuel before and after bioremediation

1994 ◽  
Vol 3 (1) ◽  
pp. 1-27
Author(s):  
David H. Rosenblatt ◽  
John F. Manning ◽  
Carlo D. Montemagno
Keyword(s):  
Health Risks ◽  
Diesel Fuel ◽  
Before And After

scholarly journals The air-resistance to a runner

1928 ◽  
Vol 102 (718) ◽  
pp. 380-385 ◽  
Keyword(s):  
Short Distance ◽  
Relative Velocity ◽  
Leeward Side ◽  
Maximum Speed ◽  
Total Resistance ◽  
Projected Area ◽  
Air Resistance ◽  
Eddy Formation ◽  
Maximal Effort ◽  
Original Treatment

The resistance of the air to the motion of a badly stream-lined body, in which the negative pressure on the leeward side, due to eddy formation, is appreciable, may be roughly 0·6 pv 2 A, where v is the relative velocity, p the density of the air, and A the projected area on a plane perpendicular to the direction of motion. In a recent paper Furusawa, Hill and Parkinson (1) have examined the motion of a runner making a maximal effort over a short distance, on the assumption that the air-resistance is negligible when compared with the resistances inherent in the muscles and limbs of the runner himself. This assumption is nearly, but not strictly, true, the air-resistance to a man running in still air at maximum speed being of the order of 2 to 5 per cent, of the total resistance which his muscles have to overcome. In view of the importance of fractions of a second in Model of runner used in wind-channel experiments; spindle visible at top. sprint “records,” and of the well - known influence of a following or head-wind in diminishing or increasing the time in such races, the original treatment of the dynamics of sprint-running may be modified to take account of the air-resistance as follows.

scholarly journals Research on Ship Hull Optimisation of High-Speed Ship Based on Viscous Flow/Potential Flow Theory

2020 ◽  
Vol 27 (1) ◽  
pp. 18-28
Author(s):  
Zhang Baoji
Keyword(s):  
High Speed ◽  
Design Method ◽  
Frictional Resistance ◽  
Linear Wave ◽  
Total Resistance ◽  
Friction Resistance ◽  
Resistance Reduction ◽  
Before And After ◽  
Reduction Effect ◽  
Cfd Method

AbstractIn order to quickly obtain practical ship forms with good resistance performance, based on the linear wave-making resistance theory, the optimal design method of ship forms with minimum total resistance is discussed by using the non-linear programming (NLP) method. Taking the total resistance as the objective function (the Michell integral is used to calculate the wave-making resistance and the equivalent plate friction resistance formula is used to calculate the frictional resistance), the hull surface offset as the design variable and appropriate displacement as the basic constraints, and considering the additional constraints, the hull bow shape and the whole ship are optimised, and an improved hull form is obtained. The resistance of the ship before and after optimisation is calculated by the CFD method to further evaluate the resistance reduction effect and performance after optimisation. Finally, an example of optimisation calculation of an actual high-speed ship is given. The obvious resistance reduction results confirm the reliability of the optimisation design method.

scholarly journals KARAKTERISTIK GELOMBANG SIGNIFIKAN DI SELAT KARIMATA DAN LAUT JAWA BERDASARKAN RERATA ANGIN 9 TAHUNAN (2005-2013)

Omni-Akuatika ◽  
2015 ◽  
Vol 11 (2) ◽  
Author(s):  
Sigit Wicaksana ◽  
Ibnu Sofian ◽  
Widodo Pranowo
Keyword(s):  
Wave Height ◽  
Input Data ◽  
Wave Characteristic ◽  
Maximum Wave Height ◽  
Significant Wave ◽  
Sea Transportation ◽  
Java Sea ◽  
Karimata Strait ◽  
Sea Wind ◽  
West Monsoon

Karimata strait and the java sea is one of the most densely shipping lanes in the maritime country of Indonesia. Information of a significant wave is needed to safety navigation. The prediction of a significant wave mostly employs the modeling using wind as input data to produce an early warning warning prediction. Characteristic of a significant wave shows the maximum wave height in the strait and the java sea karimata occurs in west monsoon (January) and east season (August) every year. Especially at the peak of west monsoon (January) maximum wave height reach 1.5-3 meters in Karimata Strait, and reach 0.5-2.5 meters in Java Sea. The frequency of significant wave occurences mostly extend until February, where wave height in Java Sea will stay the same (0.5-2.5 meters), while in Karimata Strait is little bit decrease (1-2.5 meters). Recommended to all sea transportation users, in those regions during January and February, to avoid using ship with the hull is less than 3 meters height.Keywords: significant wave characteristic, Karimata Strait, Jawa Sea, Wind, Modeling

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