Although the element is only mildly toxic, it is a hazardous material as a metal and its radioisotopes present a high health risk in case of radiation leaks.

Although X-rays are most commonly used, the beam is not always electromagnetic radiation.

Although modern quantum optics tells us that there also is a semi-classical explanation of the photoelectric effect — the emission of electrons from metallic surfaces subjected to electromagnetic radiation — the photon was historically ( although not strictly necessarily ) used to explain certain observations.

Although hair provides protection against harmful UV radiation, since our hominin ancestors were bipedal, only our heads were exposed to the noonday sun.

Although nuclear testing was halted in 1990, radiation poisoning, birth defects, severe anemia, and leukemia are very common in the area.

Although the concentration of the ozone in the ozone layer is very small, it is vitally important to life because it absorbs biologically harmful ultraviolet ( UV ) radiation coming from the sun.

Although it is often claimed that the photoelectric and Compton effects require a quantum description of the EM field, this is now understood to be untrue, and proper proof of the quantum nature of radiation is now taken up into modern quantum optics as in the antibunching effect.

Although nearly all of the ultraviolet spectrum of radiation is non-ionizing, at the same time ultraviolet radiation does far more damage to many molecules in biological systems than is accounted for by heating effects ( an example is sunburn ).

Although ultraviolet radiation is invisible to the human eye, most people are aware of the effects of UV on the skin, called suntan and sunburn.

Although their extreme blast and heat effects are not eliminated, it is the enormous radiation released by ERWs that is meant to be a major source of casualties.

Although not usually a factor in the thermal radiation of stars, polarization is also present in radiation from coherent astronomical sources ( e. g. hydroxyl or methanol masers ), and incoherent sources such as the large radio lobes in active galaxies, and pulsar radio radiation ( which may, it is speculated, sometimes be coherent ), and is also imposed upon starlight by scattering from interstellar dust.

Although the exposure might be minimal, many people find radiation exposure especially frightening because it is something they cannot see or feel, and it therefore becomes an unknown source of danger.

Although the detonation of a dirty bomb using such a source might seem terrifying, it would be hard to assemble the bomb and transport it without severe radiation damage and possible death of the perpetrators involved.

* 1948-Ralph Alpher and Robert Herman estimate " the temperature in the Universe " at 5 K. Although they do not specifically mention microwave background radiation, it may be inferred.

For a hypothetical proton lifetime of 10 < sup > 37 </ sup > years, Adams and Laughlin calculate that proton decay will raise the effective surface temperature of an old one-solar mass white dwarf to approximately 0. 06 K. Although cold, this is thought to be hotter than the temperature that the cosmic background radiation will have 10 < sup > 37 </ sup > years in the future .< sup >, § IVB .</ sup >

Although causation cannot be confirmed in these cases, caution should still be used when prescribing radiation therapy for keloids, particularly when treating younger patients. It may occasionally be appropriate as treatment for keloids resistant to other therapies.

Although such an antenna is resonant and works perfectly well at the higher frequency, the antenna radiation pattern is also altered compared to the half-wave dipole.

Although their exteriors are subjected to intense solar radiation that can alter their chemistry, their interiors contain pristine material essentially untouched since the planetesimal was formed.

Although there are claims that participants in the Crossroads tests were well protected against radiation sickness, the Oscar-nominated documentary Radio Bikini showed footage of Navy sailors wearing little or no protection during their inspection of the target ships only hours after the explosions, even though some of the observer ships were caught in the fallout of the Baker explosion.

Although trained in the delivery of chemotherapy, radiation oncologists in Australia and New Zealand rarely prescribe it.

Although the radiation of an omnidirectional antenna is symmetrical in azmuthal directions, it may vary in a complicated way with elevation angle, having lobes and nulls at different angles.

Although no national norms exist for the social development of children, the teacher can find a great deal of information concerning types of social behavior normally displayed by children at various age levels.

Although the Caiman has not been studied in-depth, scientists have learned that their mating cycles ( previously thought to be spontaneous or year-round ) are linked to the rainfall cycles and the river levels, which increases chances of survival for their offspring.

Although the range and precise application of defenses varies between jurisdictions, the following represents a list of the defenses that may apply to all levels of assault:

Although there were low levels of preexisting antibiotic-resistant bacteria before the widespread use of antibiotics, evolutionary pressure from their use has played a role in the development of muiltidrug resistance varieties and the spread of resistance between bacterial species.

Although once thought to be a simple solution of molecules, multiple levels of organization exist in the cytosol.

Although it did not achieve the same levels of commercial success as the band's later releases ( it reached # 73 on the Billboard 200 ), it has been hailed by many fans and critics as Dream Theater's masterpiece and the band's defining album.

Although the majority of WADs contain one or several custom levels mostly in the style of the original game, others implement new monsters and other resources, and heavily alter the gameplay ; several popular movies, television series, other video games and other brands from popular culture have been turned into Doom WADs by fans ( without authorization ), including Aliens, Star Wars, The X-Files, The Simpsons, South Park, Sailor Moon, Dragon Ball Z, Red Faction, The Thing, Pokémon and Batman.

Although it is claimed that, depending on their preferred learning modality, different teaching techniques have different levels of effectiveness, recent research has argued " there is no adequate evidence base to justify incorporating learning styles assessments into general educational practice.

Although individual buses are generally owned by individuals or small companies, the timetables, fares, and levels of service are set by Strandfaraskip Landsins and the government.

Although production levels give an overview, the history of British cinema is complex, with various cultural movements developing independently.

Although quite popular in the United States in the 1960s, repeated research studies have demonstrated that many healthy people will have glucose levels below 70 or 60 during a prolonged test, and that many types of significant hypoglycemia may go undetected with it.

Although all levels are present in this version and feature their correct layouts, their architecture details are somewhat simplified and there is some loss in overall lighting quality.

Although current pumps can include a glucose sensor, and they cannot automatically respond to meals or to rising or falling glucose levels.

Although " icing " increases alcohol content, most of the United States breweries simply add water back into their beer after the icing process to bring the alcohol content back down to nearly the same levels.

Although Harris did design Doom levels, they were not simulations of Columbine High School.

Although MUSH servers do not impose strong administrative hierarchies, most MUSH games establish additional levels of management besides Wizards.

Although these innovations are not all entirely new with Wadzinski, the book marks a significant advancement in published maze puzzles, offering expansions on the traditional puzzles that seem to have been fully informed by various video game innovations and designs, and adds new levels of challenge and complexity in both the design and the goals offered to the puzzle-solver in a printed format.

Although many techniques are used by vaulters at various skill levels to clear the bar, the generally accepted technical model can be broken down into several phases, listed and described below:

Although the alleged difference in sea levels could be problematic for a canal's construction, the idea of finding a shorter route to the east remained alive.

Although seemingly different, the approaches just describe the same geometric concept using different languages and at different levels of abstraction.

Although a relationship between hormone levels and ECM biosynthesis in vocal fold can be established, the details of this relationship, and the mechanisms of the influence has not been elucidated yet.

Although there is an extreme scarcity of data from Australia ( for both the Medieval Warm Period and Little Ice Age ) evidence from wave-built shingle terraces for a permanently full Lake Eyre during the 9th and 10th centuries is consistent with this La Niña-like configuration, though of itself inadequate to show how lake levels varied from year to year or what climatic conditions elsewhere in Australia were like.

Although a British test cryptanalytic attack made considerable progress, the results were not as significant as against the Enigma, due to the increased complexity of the system and the low levels of traffic.

Although the threshold of hearing is typically around 0 dB SPL, this is in fact very quiet indeed, and appliances are more likely to have noise levels of 30 to 40 dB SPL.

Although the electronic transitions of an isolated ion are very well defined, broadening of the energy levels occurs when the ions are incorporated into the glass of the optical fiber and thus the amplification window is also broadened.