Two Egyptian Construction Tools

1993 ◽  
Vol 86 (2) ◽  
pp. 166-167
Author(s):  
John F. Lamb
Keyword(s):  
Horizontal Plane ◽  
Vertical Plane ◽  
The Other

Among the objects in the Ramses II exhibition at Fair Park in Dallas in 1989 were two tools from the tomb of Sen-nedjem, one of Ramses II's workmen. One was a level for determining the horizontal plane, the other was a plumb level for determining the vertical plane.

scholarly journals 3. On the Combined Motions of the Magnetic Needle, and on the Aurora Borealis.

1851 ◽  
Vol 2 ◽  
pp. 334-350
Author(s):  
J. A. Broun
Keyword(s):  
Horizontal Plane ◽  
Magnetic Force ◽  
Vertical Plane ◽  
The Other ◽  
Aurora Borealis ◽  
Centre Of Gravity ◽  
True Position ◽  
Magnetic Needle ◽  
The Way

When a steel needle or rod is so constructed that its centre of gravity is in a finely-turned axle at right angles to its length, it will rest in any position when the axle is placed upon polished planes; when, however, we magnetize the needle, it assumes a position which is that of the direction of the magnetic force at the place: in this way we obtain the ordinary dipping-needle. The dipping-needle can obviously move only in one plane, that to which the axle is at right angles; were it possible to suspend it freely, so that it could move in every plane with every variation of the direction of the magnetic force, we should then be able, by observing the variations of its position, to determine at once the laws which a magnet in its true position obeys; this, however, we have not been able to do; even the small variations in the vertical plane, which we might expect to obtain from the ordinary dipping-needle, are nearly or altogether destroyed by the friction of the axle upon its supports; and there are many mechanical difficulties in the way of the other methods of suspension. It has been found convenient, then, to make use of the simplest methods of suspending magnets in a horizontal plane; and to endeavour to deduce, from the composition of their motions, the laws both of the variation of the force with which a truly suspended magnet is directed, and of the direction of that force itself.

The Horizontal-Vertical Illusion: Transfer of Illusion Decrement

1993 ◽  
Vol 77 (1) ◽  
pp. 339-347 ◽  
Author(s):  
Eleana Kubi ◽  
Burton M. Slotnick
Keyword(s):  
Horizontal Plane ◽  
Vertical Plane ◽  
Practice Effect ◽  
The Other ◽  
Horizontal Line ◽  
Not Given ◽  
Production Task ◽  
Alternate Form ◽  
Potential Factors ◽  
And Performance

Subjects first adjusted 20 vertical lines to be equal in length to the horizontal line in small or large inverted-T figures and were then given 10 additional trials on the other size figure. Vertical lines were made significantly shorter than the horizontal line but accuracy gradually improved and performance was not disrupted by the switch in figure size. By Trial 30, adjusted vertical lines did not differ from the length of the horizontal line. Other subjects were first tested on the small inverted-T figure and then asked to produce 1-in. lines in the vertical plane and in the horizontal plane. These subjects also improved on the adjustment task but, on the production task, were no more accurate than control subjects who were not given practice on the adjustment task. Thus, the magnitude of the Horizontal-Vertical Illusion decreases with practice alone and this practice effect readily transfers to figures of other sizes but not to an alternate form of the illusion. The potential factors responsible for the improvement and transfer are discussed.

Gnomonic Projections on two planes

1906 ◽  
Vol 14 (65) ◽  
pp. 149-156 ◽  
Author(s):  
John W. Evans
Keyword(s):  
Fixed Point ◽  
Horizontal Plane ◽  
Vertical Plane ◽  
The Other ◽  
Unit Distance ◽  
Simultaneous Use

The gnomonic projection in which the faces of crystals are represented by the points where their normals through a fixed point–the centre of projection–meet a plane–the plane of projection–is already widely used by crystallographers. I propose in the following pages to show the advantages of the simultaneous use of two such planes of projection.It is in most cases convenient for the two planes to be at right angles, and for the centre of projection to be at an equal (unit) distance from each. Circumstances, however, in some cases render it desirable to vary these conditions. When the planes are at right angles, one may conveniently be described as the horizontal plane, and the other as the vertical plane.

scholarly journals Dielectric anisotropy as indicator of crystal orientation fabric in Dome Fuji ice core: method and initial results

2021 ◽  
pp. 1-12
Author(s):  
Tomotaka Saruya ◽  
Shuji Fujita ◽  
Ryo Inoue
Keyword(s):  
Crystal Orientation ◽  
Horizontal Plane ◽  
Ice Core ◽  
Vertical Plane ◽  
Vertical Direction ◽  
Core Sample ◽  
Dielectric Anisotropy ◽  
Principal Axes ◽  
Polycrystalline Ice ◽  
Initial Results

Abstract Polycrystalline ice is known to exhibit macroscopic anisotropy in relative permittivity (ɛ) depending on the crystal orientation fabric (COF). Using a new system designed to measure the tensorial components of ɛ, we investigated the dielectric anisotropy (Δɛ) of a deep ice core sample obtained from Dome Fuji, East Antarctica. This technique permits the continuous nondestructive assessment of the COF in thick ice sections. Measurements of vertical prism sections along the core showed that the Δɛ values in the vertical direction increased with increasing depth, supporting previous findings of c-axis clustering around the vertical direction. Analyses of horizontal disk sections demonstrated that the magnitude of Δɛ in the horizontal plane was 10–15% of that in the vertical plane. In addition, the directions of the principal axes of tensorial ɛ in the horizontal plane corresponded to the long or short axis of the elliptically elongated single-pole maximum COF. The data confirmed that Δɛ in the vertical and horizontal planes adequately indicated the preferred orientations of the c-axes, and that Δɛ can be considered to represent a direct substitute for the normalized COF eigenvalues. This new method could be extremely useful as a means of investigating continuous and depth-dependent variations in COF.

Induced segmental reorganization in sabellid worms

Development ◽  
1978 ◽  
Vol 47 (1) ◽  
pp. 85-96
Author(s):  
N. J Berrill
Keyword(s):  
Unique Feature ◽  
Vertical Plane ◽  
Main Axis ◽  
The Other ◽  
Basal Portion ◽  
Thoracic Stomach ◽  
The Right ◽  
Number Of Segments ◽  
Head Regeneration ◽  
Complete Inversion

Processes of regeneration and reorganization are analyzed in two sabellid polychaetes. Abdominal pieces of Branchiomma nigromaculata, during head regeneration, ordinarily reorganize only a fraction of the number of segments typical of the thorax. In pieces transected in the vertical plane, but obliquely with regard to the main axis of the worm, the extent of reorganization is greatly enhanced. The same number of segments transform on the right and left sides, the surviving damaged segments transforming on one side and a corresponding number of more posterior, undamaged segments transforming on the other. Reorganization is shown, in abdominal pieces of Sabella melanostigma, to involve destruction and inversed dorso-ventral reconstitution of all parapodial structures in the segments affected, the conversion of intestine to thoracic stomach, and the invasion of previously abdominal segments by a pair of large nephridia which grow posteriorly after being formed in the basal portion of the head blastema. All three events exhibit a time-graded character, starting soonest at the anterior end and progressively later posteriorly, and apparently independently of one another. Abdominal type segments are formed only from the anterior region of the caudal, prepygidial zone of growth, successively, never by transformation. The dorso-ventrality of abdominal segments is the inverse of the thoracic, with the antero-posterior polarity unchanged, in all circumstances. Only during posterior regeneration from thoracic segments are thoracic segments produced from the posterior zone of growth, but only two or three are thus formed, the zone of growth then changing to the production of abdominal segments. It is concluded that the unique feature of sabellid-serpulid organization is the complete inversion of the dorso-ventrality of the posterior zone of growth as the result of emancipation from the generally dominating dorsal field emanating from the anterior end.

scholarly journals 4. On a Thermomagnetic Thermoscope

1880 ◽  
Vol 10 ◽  
pp. 538-539
Author(s):  
W. Thomson
Keyword(s):  
Magnetic Moment ◽  
Horizontal Plane ◽  
Hardened Steel ◽  
The Other ◽  
Silk Fibre ◽  
Steel Wires ◽  
The One

This thermoscope is founded on the change produced in the magnetic moment of a steel magnet by change of temperature. Several different forms suggest themselves: the one which seems best adapted to give good results is to be made as follows:—(1.) Prepare an approximately astatic system of two thin, hardened steel wires, r b, r′ b′, each 1 cm. long, one of them, r, b, hung by a single silk fibre, and the other hung bifilarly from it, by fibres about 3 cms. long, so attached that the projections of the two, on a horizontal plane, shall be inclined at an angle of about ·01 of a radian (or ·57°) to one another.

scholarly journals A New Method for the Calculation of Energy and Power Requirements of Bucket Wheel Excavators

2019 ◽  
Vol 10 (1) ◽  
pp. 15-20
Author(s):  
József András ◽  
József Kovács ◽  
Endre András ◽  
Ildikó Kertész ◽  
Ovidiu Bogdan Tomus
Keyword(s):  
Energy Consumption ◽  
Numerical Method ◽  
Horizontal Plane ◽  
Vertical Plane ◽  
New Method ◽  
Energy Requirements ◽  
Belt Conveyor ◽  
Analytical Formulas ◽  
Power And Energy ◽  
Continuous Working

Abstract The bucket wheel excavator (BWE) is a continuous working rock harvesting device which removes the rock by means of buckets armoured with teeth, mounted on the wheel and which transfers rock on a main hauling system (generally a belt conveyor). The wheel rotates in a vertical plane and swings in the horizontal plane and raised / descended in the vertical plane by a boom. In this paper we propose a graphical-numerical method in order to calculate the power and energy requirements of the main harvesting structure (the bucket wheel) of the BWE. This approach - based on virtual models of the main working units of bucket wheel excavators and their working processes - is more convenient than those based on analytical formulas and simplification hypotheses, and leads to improved operation, reduced energy consumption, increased productivity and optimal use of available actuating power.

Many-legged maneuverability: dynamics of turning in hexapods

1999 ◽  
Vol 202 (12) ◽  
pp. 1603-1623 ◽  
Author(s):  
D.L. Jindrich ◽  
R.J. Full
Keyword(s):  
Horizontal Plane ◽  
Center Of Mass ◽  
Vertical Plane ◽  
Force Production ◽  
The Body ◽  
Mean Velocity ◽  
Blaberus Discoidalis ◽  
Body Design ◽  
Reaction Forces ◽  
Straight Ahead

Remarkable similarities in the vertical plane of forward motion exist among diverse legged runners. The effect of differences in posture may be reflected instead in maneuverability occurring in the horizontal plane. The maneuver we selected was turning during rapid running by the cockroach Blaberus discoidalis, a sprawled-postured arthropod. Executing a turn successfully involves at least two requirements. The animal's mean heading (the direction of the mean velocity vector of the center of mass) must be deflected, and the animal's body must rotate to keep the body axis aligned with the heading. We used two-dimensional kinematics to estimate net forces and rotational torques, and a photoelastic technique to estimate single-leg ground-reaction forces during turning. Stride frequencies and duty factors did not differ among legs during turning. The inside legs ended their steps closer to the body than during straight-ahead running, suggesting that they contributed to turning the body. However, the inside legs did not contribute forces or torques to turning the body, but actively pushed against the turn. Legs farther from the center of rotation on the outside of the turn contributed the majority of force and torque impulse which caused the body to turn. The dynamics of turning could not be predicted from kinematic measurements alone. To interpret the single-leg forces observed during turning, we have developed a general model that relates leg force production and leg position to turning performance. The model predicts that all legs could turn the body. Front legs can contribute most effectively to turning by producing forces nearly perpendicular to the heading, whereas middle and hind legs must produce additional force parallel to the heading. The force production necessary to turn required only minor alterations in the force hexapods generate during dynamically stable, straight-ahead locomotion. A consideration of maneuverability in the horizontal plane revealed that a sprawled-postured, hexapodal body design may provide exceptional performance with simplified control.

Contractile differences between muscle units in the medial rectus and lateral rectus muscles in the cat

1986 ◽  
Vol 56 (1) ◽  
pp. 50-62 ◽  
Author(s):  
M. A. Meredith ◽  
S. J. Goldberg
Keyword(s):  
Horizontal Plane ◽  
Complex Interaction ◽  
Contractile Properties ◽  
The Other ◽  
Lateral Rectus ◽  
Medial Rectus ◽  
Types Of Muscle Fibers ◽  
Horizontal Gaze ◽  
Afferent Inputs ◽  
Central Factors

Conjugate eye movements in the horizontal plane are accomplished by the coactivation of the medial rectus (MR) muscle of one orbit and the lateral rectus (LR) muscle of the other. While control of these excursions has been thought to be effected by identical inputs to these muscles, recent studies have demonstrated that MR motoneurons receive different inputs than LR motoneurons. This raises the question of whether the character of the muscles they control are different. The present study evaluated the contractile properties of MR and LR muscle units in the cat. Based on the mechanical aspects of their contractile properties, only two physiological types of muscle units were identified within the MR and LR muscles: twitch and non-twitch muscle units. Twitch muscle units represented over 90% of the units sampled in each muscle. Significant differences in the rate-related and the tension-related contractile properties were demonstrated between MR and LR twitch muscle units. MR muscle units exhibited significantly faster twitch contractions than did LR units. The rate of stimulation at which MR units exhibited fused tetany was significantly higher than for LR units, although units from both muscles demonstrated similar rates of rise of tension at fusion. The rate of rise of tension was closely correlated to tension production (twitch and tetanus) in each muscle. However, MR muscle units demonstrated significantly weaker maximum tetanic tensions and lower tetanus-to-twitch ratios than LR units. These data indicate that while similar physiological types of muscle fibers are present within the MR and LR, MR muscle units are adapted for faster rate-related properties, whereas LR units are adapted for greater tetanic tensions. These distinctions between MR and LR muscle units, coupled with differences between the afferent inputs to their respective motoneurons, suggest that the preservation of conjugacy during horizontal gaze shifts may require a complex interaction of peripheral and central factors.

Latencies of Tee Eye and Herd to Targets in the Vertical and Horizontal Planes

1988 ◽  
Vol 32 (19) ◽  
pp. 1424-1428
Author(s):  
William P. Janson ◽  
Gloria L. Calhoun
Keyword(s):  
Head Movement ◽  
Horizontal Plane ◽  
Vertical Plane ◽  
Small Sample ◽  
Tracking Task ◽  
Manual Tracking ◽  
Verbal Command ◽  
Latency Data ◽  
Oculomotor Responses ◽  
Small Sample Sizes

Past studies involving oculomotor responses have typically been limited to refixations along the horizontal plane, small sample sizes, and little data pertaining to head movement. The study reported herein addresses these data voids by collecting both eye and head latency data for refixations in the horizontal and vertical planes. The subjects' task was to perform a central manual tracking task while periodically responding to a verbal command to classify a target on one of four peripheral monitors. Two targets were displayed along the horizontal plane and two along the vertical plane. Results from 620 trials indicated similar trends for the eye and head latency across all four monitor locations, suggesting no significant differences in eye or head latency as a function of target plane.

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