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 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 ice forms on the beds, trucks can be driven onto the ice to spread a thin layer of sand that helps to control pests and rejuvenate the vines.

* When the metal atoms are hexagonal close packed, ( hcp ), as the octahedral interstices lie directly opposite each other on either side of the layer of metal atoms, filling only one of these with carbon achieves 2: 1 stoichiometry with the CdI < sub > 2 </ sub > structure.

When the hailstone moves into an area with a high concentration of water droplets, it captures the latter and acquires a translucent layer.

When the surface glycosaminoglycan ( GAG ) layer is damaged ( via a urinary tract infection ( UTI ), excessive consumption of coffee or sodas, traumatic injury, etc.

When the user pushes down at a particular position, their finger pushes the front layer down through the spacer layer to close a circuit at one of the intersections of the grid.

When no voltage is applied to a TN liquid crystal cell, polarized light passes through the 90-degrees twisted LC layer.

When physical chemist Richard Williams applied an electric field to a thin layer of a nematic liquid crystal at 125 ° C, he observed the formation of a regular pattern that he called domains ( now known as Williams Domains ).

When an electric field is applied to the LC layer, the long molecular axes tend to align parallel to the electric field thus gradually untwisting in the center of the liquid crystal layer.

When core convection does not occur, a helium-rich core develops surrounded by an outer layer of hydrogen.

When extended indefinitely, a layer of hexagonal boron nitride, BN, is obtained, with a structure identical to that of graphene apart from the alternation between boron and nitrogen in each ring.

When a layer of shingles wears out, they are usually stripped, along with the underlay and roofing nails, allowing a new layer to be installed.

When stainless steel parts such as nuts and bolts are forced together, the oxide layer can be scraped off, causing the parts to weld together.

When it first forms, this protective layer is only 1 – 2 nm thick but continues to slowly grow ; reaching a thickness of 25 nm in four years.

When exposed to nitrogen clean titanium metal is covered with a titanium nitride layer.

When the client program on the destination computer receives them, the TCP layer ( Transport Layer ) reassembles the individual segments and ensures they are correctly ordered and error free as it streams them to an application.

When finely divided, it can react with cold water ; in air, uranium metal becomes coated with a dark layer of uranium oxide.

When a voltage is applied between the gate and body terminals, the electric field generated penetrates through the oxide and creates an " inversion layer " or " channel " at the semiconductor-insulator interface.

When a ground plane layer is present underneath, it forms a transmission line ( stripline ) with the trace.

When light is transmitted through a layer of magneto-optic material, the result is called the Faraday effect: the plane of polarization can be rotated, forming a Faraday rotator.

When identifying communication partners, the application layer determines the identity and availability of communication partners for an application with data to transmit.