A Novel Continuous Alternate Motion Mechanism With Two Input Wheels

2006 ◽  
Vol 129 (8) ◽  
pp. 858-864 ◽  
Author(s):  
Giuseppe Quaglia ◽  
Daniela Maffiodo ◽  
Francesco Pescarmona
Keyword(s):  
Constant Velocity ◽  
Constant Angular Velocity ◽  
The Other ◽  
Input And Output ◽  
Acceleration And Deceleration ◽  
Proper Design ◽  
Parallel Input ◽  
Toothed Gears ◽  
Analogous Mechanism ◽  
Opposite Motion

This paper presents the design of a mechanism with the following specifications: continuous alternate motion, wide motion phases with constant angular velocity, parallel input and output shafts, and great strokes. Those specifications derive from a possible application in the textile field. The mechanism is composed of two star wheels properly coupled together: there are two counter-rotating input wheels, alternately coupling with slots first, then teeth at each side of the output wheel. As usual for star wheels, pins and slots handle the acceleration and deceleration phases, while the constant velocity phase is performed by coupling sectors of toothed gears. A proper design of pins and slots is performed, so that at the same time when a pin from one input wheel is releasing a slot, a pin from the other input wheel engages a slot on the other side of the output wheel, forcing the latter to an opposite motion. In this way the output wheel has a continuous and smooth alternate motion. By annihilating the arrest phases typical of star wheels, the proposed system eliminates the discontinuities in the acceleration diagram. The paper develops a complete parametrical analysis of the device, underlining the effect of the constraints on the shape of the motion laws with particular emphasis on the acceleration and deceleration phases. In this way the output wheel has a continuous and smooth alternate motion. With respect to an analogous mechanism realizing the same laws of motion, e.g., cams, this device is very compact and economical, also presenting parallel input and output shafts, and significantly reduces sliding and wear.

Kinematic Properties of Tripode (Tri-pot) Joints

1975 ◽  
Vol 97 (2) ◽  
pp. 708-713 ◽  
Author(s):  
Metin M. Durum
Keyword(s):  
Fixed Point ◽  
Constant Velocity ◽  
Orbital Motion ◽  
The Other ◽  
Shaft Speed ◽  
Fixed Plane ◽  
Input And Output ◽  
Constant Velocity Joint ◽  
Angular Velocities ◽  
Kinematic Properties

The geometry of tripode (also called tri-pot) joints or shaft couplings is simplified by folding one side onto the other, and the kinematic properties are obtained. Due to a built-in orbital motion, a tripode joint cannot be used alone between two shafts of fixed axes; therefore it cannot directly be compared with a typical CV (constant-velocity) joint. Yet it is shown that: (a) if its shafts are kept parallel to a fixed plane a tripode joint transmits equal rotations as other CV joints do; (b) if one shaft axis is fixed and the other shaft axis has a fixed point, input and output angular velocities slightly differ, with a cycle of three times shaft speed; (c) to transmit rotation between two shafts of fixed axes, a tripode joint must be incorporated with another tripode or CV joint or a mechanism. In this case deviation between input and output angular velocities can be made very small or even nil.

Epitasis and Anesis in Aristotle, De caelo 2.6

Phronesis ◽  
2016 ◽  
Vol 61 (1) ◽  
pp. 33-42 ◽  
Author(s):  
Stephen E. Kidd
Keyword(s):  
The Other ◽  
Irregular Motion ◽  
Acceleration And Deceleration ◽  
The One

De caelo 2.6 describes irregular motion differently from the discussion at Physics 5.4. The desire to make the one discussion congrue with the other has strained interpretation of the De caelo passage. Aristotle provides a theory of irregular motion that is tripartite and the passage ought to be interpreted in such a way as to explain this tripartite motion. Akmē is not a ‘top speed’ as it is generally translated, but a point in an object’s motion when epitasis must become anesis. Although the terms epitasis and anesis cover ‘acceleration’ and ‘deceleration’ they cannot be reduced to them.

scholarly journals The influence of vortices upon the resitance experienced by solids moving through a liquid

1928 ◽  
Vol 119 (781) ◽  
pp. 146-156 ◽  
Keyword(s):  
Perfect Fluid ◽  
Relative Motion ◽  
Constant Velocity ◽  
Fluid Motion ◽  
Resultant Force ◽  
The Other ◽  
Two Dimensional ◽  
Perfect Fluids ◽  
Potential Problems ◽  
The Moment

(1) It is not so long ago that it was generally believed that the "classical" hydrodynamics, as dealing with perfect fluids, was, by reason of the very limitations implied in the term "perfect," incapable of explaining many of the observed facts of fluid motion. The paradox of d'Alembert, that a solid moving through a liquid with constant velocity experienced no resultant force, was in direct contradiction with the observed facts, and, among other things, made the lift on an aeroplane wing as difficult to explain as the drag. The work of Lanchester and Prandtl, however, showed that lift could be explained if there was "circulation" round the aerofoil. Of course, in a truly perfect fluid, this circulation could not be produced—it does need viscosity to originate it—but once produced, the lift follows from the theory appropriate to perfect fluids. It has thus been found possible to explain and calculate lift by means of the classical theory, viscosity only playing a significant part in the close neighbourhood ("grenzchicht") of the solid. It is proposed to show, in the present paper, how the presence of vortices in the fluid may cause a force to act on the solid, with a component in the line of motion, and so, at least partially, explain drag. It has long been realised that a body moving through a fluid sets up a train of eddies. The formation of these needs a supply of energy, ultimately dissipated by viscosity, which qualitatively explains the resistance experienced by the solid. It will be shown that the effect of these eddies is not confined to the moment of their birth, but that, so long as they exist, the resultant of the pressure on the solid does not vanish. This idea is not absolutely new; it appears in a recent paper by W. Müller. Müller uses some results due to M. Lagally, who calculates the resultant force on an immersed solid for a general fluid motion. The result, as far as it concerns vortices, contains their velocities relative to the solid. Despite this, the term — ½ ρq 2 only was used in the pressure equation, although the other term, ρ ∂Φ / ∂t , must exist on account of the motion. (There is, by Lagally's formulæ, no force without relative motion.) The analysis in the present paper was undertaken partly to supply this omission and partly to check the result of some work upon two-dimensional potential problems in general that it is hoped to publish shortly.

scholarly journals Using Kalman Filters to Reduce Noise from RFID Location System

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Pedro Henriques Abreu ◽  
José Xavier ◽  
Daniel Castro Silva ◽  
Luís Paulo Reis ◽  
Marcelo Petry
Keyword(s):  
Kalman Filter ◽  
Kalman Filters ◽  
Constant Velocity ◽  
Research Work ◽  
The Other ◽  
Full Potential ◽  
Comparison Study ◽  
Location System ◽  
Oval Shape ◽  
Location Systems

Nowadays, there are many technologies that support location systems involving intrusive and nonintrusive equipment and also varying in terms of precision, range, and cost. However, the developers some time neglect the noise introduced by these systems, which prevents these systems from reaching their full potential. Focused on this problem, in this research work a comparison study between three different filters was performed in order to reduce the noise introduced by a location system based on RFID UWB technology with an associated error of approximately 18 cm. To achieve this goal, a set of experiments was devised and executed using a miniature train moving at constant velocity in a scenario with two distinct shapes—linear and oval. Also, this train was equipped with a varying number of active tags. The obtained results proved that the Kalman Filter achieved better results when compared to the other two filters. Also, this filter increases the performance of the location system by 15% and 12% for the linear and oval paths respectively, when using one tag. For a multiple tags and oval shape similar results were obtained (11–13% of improvement).

scholarly journals Effects of Drugs and Excipients on Hydration Status

Nutrients ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 669 ◽  
Author(s):  
Ana Puga ◽  
Sara Lopez-Oliva ◽  
Carmen Trives ◽  
Teresa Partearroyo ◽  
Gregorio Varela-Moreiras
Keyword(s):  
Gastrointestinal Tract ◽  
Water Balance ◽  
Gastrointestinal Transit ◽  
The Other ◽  
Hydration Status ◽  
Gastrointestinal Transit Time ◽  
Input And Output ◽  
Water Elimination ◽  
Essential Nutrient ◽  
The Difference

Despite being the most essential nutrient, water is commonly forgotten in the fields of pharmacy and nutrition. Hydration status is determined by water balance (the difference between water input and output). Hypohydration or negative water balance is affected by numerous factors, either internal (i.e., a lack of thirst sensation) or external (e.g., polypharmacy or chronic consumption of certain drugs). However, to date, research on the interaction between hydration status and drugs/excipients has been scarce. Drugs may trigger the appearance of hypohydration by means of the increase of water elimination through either diarrhea, urine or sweat; a decrease in thirst sensation or appetite; or the alteration of central thermoregulation. On the other hand, pharmaceutical excipients induce alterations in hydration status by decreasing the gastrointestinal transit time or increasing the gastrointestinal tract rate or intestinal permeability. In the present review, we evaluate studies that focus on the effects of drugs/excipients on hydration status. These studies support the aim of monitoring the hydration status in patients, mainly in those population segments with a higher risk, to avoid complications and associated pathologies, which are key axes in both pharmaceutical care and the field of nutrition.

scholarly journals Gender-wise contribution in carbon management by high himalayan ethnic group of Gatlang VDC, Rasuwa, Nepal

2016 ◽  
Vol 4 ◽  
pp. 39-46 ◽  
Author(s):  
Rashila Deshar ◽  
Madan Koirala
Keyword(s):  
Decision Making ◽  
Ethnic Group ◽  
The Other ◽  
Decision Making Process ◽  
Fuel Wood ◽  
Men And Women ◽  
Carbon Management ◽  
Input And Output ◽  
Participation In Decision Making ◽  
Major Decision

In mountainous country Nepal having large populations of culturally unique indigenous peoples poses threats of glaciers retreat and resource bases change. The indigenous people living in mountain plays the major role in carbon management. Further, the role and responsibilities of men and women varies differently in natural resource conservation and management. However, their participation in decision-making and benefit sharing is poor. The majority of women have unequal access to productive resources and decision-making process. Therefore, study on gender based agro-pastoral activities, their contribution on carbon management and decision-making process were carried out in Tamang ethnic group of Gatlang VDC of Rasuwa district, Nepal. For the purpose, 30 households were selected purposively. Similarly, four focus group discussions were carried out among the separate group of women, men and group consisting both men and women. Carbon management types: input carbon and output carbon activities were studied on men and women. In total, 23 different agro-pastorals related activities were found, among them 57% of work were supported by women, 39% by both men and women, and 4% by men only. With respect to fuel-wood, in average, 10 kg per day fuelwood is necessary for one household. The use of biomass for cooking emits chocking smoke and causes indoor air pollution. All these disadvantages lead to carbon emission which might lead to health deterioration of women by increasing the risk of cardiovascular diseases and respiratory disorders. The average fuel-wood requirement was found to be 840 kg/capita/year which are found to be higher than the other physiographic regions of Nepal. This is due to use of fuel-wood as only source of energy in the study area. Out of total respondent, it was observed that 30% literate men allow their wife to make joint decision on the major household issues. Similarly, 3% literate women respondents took the major decision by their own or jointly with their husbands. On the other hand, 30% illiterate men and 37% illiterate women either didn’t allow their wife or don’t participate in major decision-making process. Further, it is revealed from the chi square test that literacy plays major role in decision making (x2 = 5.625, df =1, p=0.017). Similarly, educated women actively join together with their husband in decision making. Moreover, women have high contribution in carbon input and output activities. Therefore, the women education should be promoted to make their equal and strong participation in decision making, which ultimately contribute in carbon input and output activities, through their greater roles in livestock husbandry and fuel-wood management relative to men. Further, importance of women’s role in carbon management should be given greater prominence.

Study of Ka-band TM01 to TE11 Mode Converters with Parallel Input and Output Waveguides

2013 ◽  
Vol 35 (2) ◽  
pp. 179-186 ◽  
Author(s):  
Xin-Jian Niu ◽  
Xian-Neng Zhu ◽  
Ying-Hui Liu ◽  
Xin-Hua Yu ◽  
Hong-Fu Li
Keyword(s):  
Ka Band ◽  
Input And Output ◽  
Mode Converters ◽  
Parallel Input

Fluctuating Flow of a Viscoelastic Fluid in a Porous Channel

1979 ◽  
Vol 46 (1) ◽  
pp. 21-25 ◽  
Author(s):  
R. K. Bhatnagar
Keyword(s):  
Reynolds Number ◽  
Viscoelastic Fluid ◽  
Mass Flux ◽  
Constant Velocity ◽  
Frequency Parameter ◽  
Viscous Fluids ◽  
The Other ◽  
Phase Lag ◽  
Viscoelastic Parameter ◽  
Viscosity Parameter

The problem of flow of a viscoelastic fluid characterized by the well-known Rivlin-Ericksen constitutive equations is discussed, when such a fluid is driven by an unsteady pressure gradient in the region between two parallel porous plates. It is assumed that on one plate the fluid is injected with certain constant velocity and that it is sucked off at the other with the same velocity. The governing differential equations, which do not involve the cross-viscosity parameter, are solved using a pertubation scheme treating the viscoelastic parameter to be small. The behavior of instantaneous velocity profiles, and magnitude and the phase lag of mass flux, which depend on the injection Reynolds number, the frequency parameter, and the viscoelastic parameter are discussed for various values of these parameters. Some very interesting departures of these from the corresponding flow of classical viscous fluids are reported when one or both of the injection Reynolds number and frequency parameter are small or large.

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