Mechanical movements use an escapement mechanism to control and limit the unwinding and winding parts of a spring, converting what would otherwise be a simple unwinding into a controlled and periodic energy release.

In some areas, upwelling is a seasonal event leading to periodic bursts of productivity similar to spring blooms in coastal waters.

The Department's constant fight with the House for money is a polite minuet compared with its periodic bloody engagements with the Senate.

It is in group 18 ( noble gases ) of the periodic table.

As expected by periodic trends, it is more electronegative than tin or bismuth, and less electronegative than tellurium or arsenic.

The group of elements is more diverse than the lanthanides and therefore it was not until 1945 that Glenn T. Seaborg proposed the most significant change to Mendeleev's periodic table, by introducing the actinides.

This transuranic element of the actinide series is located in the periodic table below the lanthanide element europium, and thus by analogy was named after another continent, America.

Among the first 101 elements in the periodic table, only francium is less stable.

The table itself is a visual representation of the periodic law, which states that certain chemical properties of elements repeat periodically when arranged by atomic number.

These results refined Ernest Rutherford's and Antonius Van den Broek's model, which proposed that the atom contains in its nucleus a number of positive nuclear charges that is equal to its ( atomic ) number in the periodic table.

As the meter is defined in terms of the second, and the speed of light is constant for all observers, the terrestrial meter appears to change in length compared to the " planetary meter " on a periodic basis.

Evidence of this is the Antarctic Circumpolar Wave, a periodic oscillation that affects the climate of much of the southern hemisphere.

It is a mathematical tool for finding repeating patterns, such as the presence of a periodic signal which has been buried under noise, or identifying the missing fundamental frequency in a signal implied by its harmonic frequencies.

Botswana is affected by periodic droughts, and seasonal August winds blow from the west, carrying sand and dust, which can obscure visibility.

It is one of only two elements on the periodic table that are known to be liquids at room temperature ( mercury is the other, although caesium, gallium, and rubidium melt just above room temperature ).

In the periodic table, it is located to the right of the actinide curium, to the left of the actinide californium and below the lanthanide terbium with which it shares many similarities in physical and chemical properties.

In order to win the final cash prize, all the contestants have to do is survive periodic evictions and be the last one standing.

The standard presentation of the chemical elements is in the periodic table, which orders elements by atomic number and groups them by electron configuration.

As a member of group 14 on the periodic table, it is nonmetallic and tetravalent — making four electrons available to form covalent chemical bonds.

The periodic arrays of submicrometre spherical particles provide similar arrays of interstitial voids, which act as a natural diffraction grating for visible light waves, particularly when the interstitial spacing is of the same order of magnitude as the incident lightwave.

The electrical part of the heart is centered on the periodic contraction ( squeezing ) of the muscle cells that is caused by the cardiac pacemaker located in the sinoatrial node.

Rainfall is irregular, historically causing periodic droughts and famines.

One of the most convenient, and certainly the most traditional presentation of the elements, is in form of periodic table, which groups elements with similar chemical properties ( and usually also similar electronic structures ) together.

A more refined classification is often shown in colored presentations of the periodic table ; this system restricts the terms " metal " and " nonmetal " to only certain of the more broadly defined metals and nonmetals, adding additional terms for certain sets of the more broadly viewed metals and nonmetals.

Other archaeologists think instead that the main purpose of the road system was a religious one, providing pathways for periodic pilgrimages and facilitating regional gatherings for seasonal ceremonies.

Afghanistan's relations with Iran have fluctuated over the last decades, with periodic disputes over the water rights of the Helmand River as one of the main issues of contention.

In chemistry and atomic physics, main group elements are elements in groups ( periodic columns ) whose lightest members are represented by helium, lithium,

Models by Julio Ángel Fernández suggest that the scattered disc, which is the main source for periodic comets in the Solar System, might also be the primary source for Oort cloud objects.

It is a main group metal in group 14 of the periodic table.

There are two main types of sound sources in the articulatory system: periodic ( or more precisely semi-periodic ) and aperiodic.

On a standard periodic table these elements, as well as the elements commonly recognized as metalloids, occur in or near a diagonal region of the p-block, having its main axis anchored by boron at one end and astatine at the other.

*' Between the metals and nonmetals in the periodic table we find elements … share some of the characteristic properties of both the metals and nonmetals, making it difficult to place them in either of these two main categories.

These variations have periodic components, the main one being the approximately 11-year solar cycle ( or sunspot cycle ).

It was introduced in 1929 by Sir John Lennard-Jones with the description of bonding in the diatomic molecules of the first main row of the periodic table, but had been used earlier by Linus Pauling for H < sub > 2 </ sub >< sup >+</ sup >.

When the two sides convened again on 17 October, there were two main areas of disagreement: the periodic replacement of South Vietnam's American weaponry, and the release of political prisoners held by the Saigon government.

If driven by a periodic sinewave ( alternating current ) the component will be characterised by its complex impedance Z ( ω ) = R + j X ( ω ); the impedance can involve several minor resistances, inductances and capacitances in addition to the main property.

In the notation of the periodic table, the main shells of electrons are labeled:

In the northeast, where fire was infrequent and periodic windthrow represented the main source of disturbance, beech-maple forests dominated.

By turning on an option at the main menu the player controlling the state of North Carolina will get periodic reinforcements by ship.

In one-shot mode the comparator fires an interrupt once when the main counter reaches the value stored in the comparator's register, while in the periodic mode the interrupts are generated at specified intervals.

After periodic flooding in the 1920s, a survey was made, indicating that the fall on the main drain was around 2 inches per mile ( 30 mm per km ), which was not sufficient for good drainage by gravity.

The periodic sentence emphasizes its main idea by placing it at the end, following all the subordinate clauses and other modifiers that support the principal idea.