When the North Tower was struck at 8: 46 a. m., many executives began evacuating their employees from the upper floors of the South Tower.

When the Universe was very young, it was likely infused with dark energy, but with less space and everything closer together, gravity had the upper hand, and it was slowly braking the expansion.

When Colonel de Gaulle did organize a counter-attack with superior French tanks, he did not have the air support to gain the upper hand and had to retreat.

When permission for marriage was granted by the upper strata of the society, the permission process required a human exchange ( mi-brjes, ).

When the axes are drawn according to the mathematical custom, the numbering goes counter-clockwise starting from the upper right (" northeast ") quadrant.

When the upper layer cooled so its density was greater than the lower layer, the waters mixed ( 1978 – 79 ).

When playing in the instrument's upper range ( above the G below middle C ), the player shifts their hand out from behind the neck and flattens it out, using the side of the thumb to press down the string.

When brought to a boil, the steam produced in the lower pot transfers heat to the upper pot.

When Europeans first arrived on Guam Chamorro society roughly fell into three classes: matao ( upper class ), achaot ( middle class ), and mana ' chang ( lower class ).

When a union of the evangelicals in upper and lower Germany was contemplated as a means of improved defense against the retaliatory measures of the Roman Catholic Church, George had a meeting with Elector John of Saxony at Schleitz in 1529, where they agreed on certain articles of faith and confession to be drawn up by Luther ; the commission was executed in the seventeen articles of Schwabach on the basis of the fifteen theses of the Marburg Colloquy.

When actress Louise Brooks met Bogart in 1924, he had some scarred tissue on his upper lip, which Belmont Bogart may have partially repaired before Bogart went into films in 1930.

When depressed, the upper key lifts the " dogleg " jack ( jack A ) upwards.

When the rudder was in its normal position the tiller was inserted in the upper hole so that the tiller faced athwartwise.

When the pankratiasts fought standing, the combat was called anō pankration ( ἄνω παγκράτιον " upper pankration "); and when they took the fight to the ground, that stage of pankration competition was called katō pankration ( κάτω παγκράτιον " lower pankration ").

When the athlete executes the spin, the upper body is twisted hard to the right, so the imaginary lines created by the shoulders and hips are no longer parallel.

When it affects the lower urinary tract it is known as a simple cystitis ( a bladder infection ) and when it affects the upper urinary tract it is known as pyelonephritis ( a kidney infection ).

When a voice is loaded, the upper pitch limit will decrease and the lower pitch limit will rise.

When the first Europeans arrived, the most powerful states in precolonial Zambia were the kingdom of Barotseland in the upper Zambezi, and the kingdom of Mwata Kazembe on the Luapula.

When slalom skiing is done properly, the skier will experience numerous isometric contractions ( good training for core muscles ), and extreme upper body torque, making it a good form of exercise.

When the dinner jacket ( tuxedo in American English ) first came into fashion in the Victorian era, it was used as a less formal alternative for the tailcoat which men of the upper classes wore every evening.

When rapid parallel turns are quickly linked together, the upper body remains pointed down the fall line, and the lower body and skis are alternately driven into the snow in one direction and then the other.

When the stadium was renovated in the 1970s, 10 rows were added to the top of upper deck, and the support columns were removed.

When conditions in the upper mixed layer ( nutrients and light ) are favourable ( e. g. at the start of spring ) their competitive edge allows them to quickly dominate phytoplankton communities (" boom " or " bloom ").

When conditions turn unfavourable, usually upon depletion of nutrients, diatom cells typically increase in sinking rate and exit the upper mixed layer (" bust ").

When playing the piano or harp, the upper staff is normally played with the right hand and the lower staff with the left hand.

When the system is arranged for automatic leveling, the platform angles respond to any horizontal components of acceleration acting on the accelerometers.

: When comparing the above illustration to the below text, please note that the above x: y aspect ratio values are shown as vertical orientation rectangles to better demonstrate visual differences, whereas the aspect ratio values of the text below are written as rotated horizontal orientation rectangles ( e. g. compare 3: 4 vertical orientation illustration to 4: 3 horizontal orientation text ).

When the angle θ does not satisfy the above condition, the horizontal component of force exerted by the road does not provide the correct centripetal force, and an additional frictional force tangential to the road surface is called upon to provide the difference.

When multiple structures are aligned with each other, such as buildings along a street, the horizontal tops and bottoms of the structures will all typically converge at a vanishing point.

When rock units are placed under horizontal compression, they shorten and become thicker.

When genes are inserted, they usually come from a different species, which is a form of horizontal gene transfer.

When the chordline is horizontal, the trailing edge has a downward direction and since the air follows the trailing edge it is deflected downward.

When the sun is visible in the polar sky, it appears to move in a horizontal circle above the horizon.

When a court binds itself, this application of the doctrine of precedent is sometimes called horizontal stare decisis.

When hovering against a building in the same ' doors-up ' horizontal orientation in " Day of the Moon ", however, the doors opened inward as usual for the arrival of Amelia's daughter, River Song.

When the hop bines run out of material to climb, horizontal shoots sprout between the leaves of the main stem to form a network of stems wound round each other.

When gymnasts compete on the horizontal bar they are often required by the Code of Points to use specific grips.

When four or more capsule halves or viruses of matching color are aligned in vertical or horizontal configurations, they are removed from play.

When the fans are closed ( horizontal ) the resonators are partially occluded, reducing the resonance of the fundamental pitch.

When threatened it usually flees, seemingly to avoid a conflict, and if detained may further avoid contact with quick horizontal rotating movements.

When feeding in shallow water it will dip its head and neck under the water, and it is able to keep its head flat against the bottom while keeping its body horizontal.

When a photographic film is exposed to light, the result of the exposure can be represented on a graph showing log of exposure on the horizontal axis, and density, or log of transmittance, on the vertical axis.

When the middle horizontal wheel has made 1 revolution, the carriage will have gone 1 li and the wooden figure in the lower story will strike the drum.

When AHL is detected, SdiA regulates the rck operon on the Salmonella virulence plasmid ( pefI-srgD-srgA-srgB-rck-srgC ) and a single gene horizontal acquisition in the chromosome srgE.

When the interface between these two surfaces is not horizontal and the system is close to hydrostatic equilibrium, the gradient of the pressure is vertical but the gradient of the density is not.

When using an anamorphic lens, as is common in analog cinematography, lens flare can manifest itself as a horizontal lines.

When it is put into a near vertical dive, the lift from the wings and horizontal tail are no longer balanced and cause the aircraft to return to level flight, tracking across the target unless the pilot applies considerable force to keep the nose down, with a corresponding decrease in accuracy.

When the paddle is pressed to the right, a horizontal pendulum is set into motion which rocks against the contact points, sending a series of short pulses ( dits ) at a speed which is controlled by the position of the pendulum weight.