62 résultats pour "componentes"

• Mechanics I INTRODUCTION Mechanics, branch of physics concerning the motions of objects and their response to forces.

  Components of VelocityNeglecting air resistance, a ball thrown into the air at an angle will travel in a parabolic path. The velocity of the ball (V)has independent vertical (V) and horizontal (H) components; the horizontal component stays the same the entire time theball is in the air, while the vertical component, the only component affected by gravity, changes continuously while theball is aloft.© Microsoft Corporation. All Rights Reserved. To understand why and how objects accelerate, force...

• Canadian Forces.

  As the Land Force Command component of the CF, the Canadian army is responsible for land combat and for physically protecting people and land-based resources. Itis the component of the CF most often called on to support international military operations and peacekeeping missions and to maintain order in times of civil unrest. A Organization The 20,900 personnel who comprise the army’s regular force are organized into four geographically based areas. Land Force Atlantic includes the provinces of...

• Radio - ciencia y tecnologia.

  Modulación de radioLas ondas de frecuencia audio hay que mezclarlas con ondas portadoras para poder ser emitidas por la radio. Es necesario modificarla frecuencia (ritmo de oscilación) o la amplitud (altura) mediante un proceso denominado modulación. Estos dos procesos explican laexistencia de los dos tipos de estaciones AM o FM en la radio. Las señales son totalmente diferentes, por lo que no pueden recibirsesimultáneamente.© Microsoft Corporation. Reservados todos los derechos. La modulación d...

• Cell (biology) - biology.

  proteins, or other proteins required by the cell. While relatively simple in construction, prokaryotic cells display extremely complex activity. They have a greater range of biochemical reactions than those found in theirlarger relatives, the eukaryotic cells. The extraordinary biochemical diversity of prokaryotic cells is manifested in the wide-ranging lifestyles of the archaebacteria andthe bacteria, whose habitats include polar ice, deserts, and hydrothermal vents—deep regions of the ocean un...

• COMPONENTES DEL ESPIRITU RELIGIOSO ESPANOL

  4 { Cf!mo a pesar de la lucha entre los dos bandos, el espiritu espanol sufri(J infiujos del espiritu ârabe ? c· A usled le parece que la f;Ut-rra pueda ser ''el media mdc: efilaz que trenen lo> pueblos para eyerrer :,us reciprocas injluencias i1 ? 5 { Cômo el misticismo e.c:paFiol, cristiano de inspiraciôn ardbigo de forma, ,',e expreso en la !iteratura del ,',lglo ){l'l) c Cmno Ga;1i;·ct puede entender el fanatisrno, furyado en aquella l...

• Sangre - ciencias de la naturaleza.

  Leucocito granulosoLos glóbulos blancos presentes en la sangre incluyen los leucocitos granulosos y los no granulosos. Los leucocitos granulososrepresentados aquí son células polimorfonucleares que tienen un aspecto granular, de ahí su nombre común.Andrew Syred/Science Photo Library/Photo Researchers, Inc. Las células o glóbulos blancos de la sangre son de dos tipos principales: los granulosos, con núcleo multilobulado, y los no granulosos, que tienen un núcleo redondeado.Los leucocitos granulos...

• Microeconomics.

  changes in any of their underlying determinants. Thus, for example, fairly confident and precise predictions can be made about how changes in consumers' preferencesor in technology are likely to affect demand, supply, and equilibrium output, but only under conditions of perfect competition. Although the model of the firm under conditions of perfect competition is the starting point of the theory of supply in microeconomics, it is generally accepted thatmarkets are not usually characterized by pe...

• Nutrición humana - ciencias de la naturaleza.

  Las proteínas son nutrientes que no se almacenan en el organismo, por lo que es necesario incluirlas en la dieta diaria. La cantidad de proteínas que se debe ingerir cada díadepende de muchos factores, como la edad o el estado de salud. Por lo general, las necesidades proteicas de un adulto sano son aproximadamente 0,8-1 g/kg de peso ydía. Cuando se ingieren proteínas en exceso, lo cual es frecuente en países con dietas ricas en carne, las proteínas sobrantes se descomponen en compuestos product...

• Electrónica - ciencia y tecnologia.

  Amplificador triodoUn circuito amplificador triodo consta además de un triodo, de un reóstato de carga, baterías y una fuente de tensión variable. Eltriodo es un tubo de cristal al vacío que contiene un cátodo C, un ánodo A y una rejilla de control G. La batería A calienta el filamentoque hay en el cátodo, de manera que los electrones pueden moverse libremente. La batería B mantiene una diferencia de potencialentre el cátodo y el ánodo, y suministra la energía que los electrones ganan al fluir d...

• Cleveland (Ohio) - geography.

  Cleveland Children’s Museum. Also located in University Circle is Severance Hall, the home of the world-acclaimed Cleveland Orchestra. Nearby is the Cleveland PlayHouse, with three large, restored theaters and one of the largest non-profit professional theaters in the country. Downtown is Playhouse Square Center, with fourrecently restored theaters, home to the Cleveland Opera and the Great Lakes Theater Festival. On the waterfront is the Rock and Roll Hall of Fame and Museum,opened in 1995 and...

• Blood.

  substances. For example, a person who is blood type A positive will not make antibodies against the A or Rh markers, but will make antibodies against the B marker,which is not on that person’s own red blood cells. If blood containing the B marker (from types B positive, B negative, AB positive, or AB negative) is transfused into thisperson, then the transfused red blood cells will be rapidly destroyed by the patient’s anti-B antibodies. In this case, the transfusion will do the patient no good a...

• El ordenador - (exposé gratuit en espagnol).

  FUNCIONAMIENTO DEL ORDENADOR Los primeros ordenadores solo servían para realizar cálculos matemáticos, pero en la actualidad se usan con fines muy variados. Encualquier caso, el esquema de funcionamiento de un ordenador siempre es el mismo: 1. Primero hay que introducir datos en el ordenador: se puede hacer a mano, mediante el teclado, o introduciéndolos desde algún soporte, como un disquete o un CD-ROM. 2. A continuación, el ordenador procesa los datos. 3. Por último, el ordenador nos propo...

• Virus - ciencias de la naturaleza.

  BacteriófagoLos bacteriófagos son virus que parasitan bacterias. Tienen una estructura compleja formada por una cabeza, que contiene el materialgenético, y una cola que consta de unas fibras con las que se anclan a la superficie bacteriana. El material genético del bacteriófagopasa desde la cabeza, a través de la cola, hasta el interior de la bacteria. El material genético del virus se integra dentro del materialgenético bacteriano y se replica. De esta manera el virus se reproduce y forma nuevo...

• Concepts

  suggested that concept possession need not consist in knowing a definition, but in appreciating the role of a concept in thought and practice. Moreover, he claimed, a concept need not apply to things by virtue of some closed set of features captured by a definition, but rather by virtue of ‘family resemblances' among the things, a suggestion that has given rise in psychology to ‘prototype' theories of concepts. Most traditional approaches to possession conditions have been concerned with t...

• Turbine.

  steam turbine has supplanted the reciprocating engine as a prime mover in large electricity-generating plants and is also used as a means of jet propulsion. Steam turbines are used in the generation of nuclear power and in nuclear ship propulsion. They operate with fuel-fired boilers for power generation. In cogenerationapplications requiring both process heat (heat used in an industrial process) and electricity, steam is raised at high pressure in the boiler and extracted from the turbineat th...

• Radio.

  signal, such as a musical note. This form of modulation, AM, is used in many radiotelephony services including standard radiobroadcasts. AM is also employed for carriercurrent telephony, in which the modulated carrier is transmitted by wire, and in the transmission of still pictures by wire or radio. See Broadcasting, Radio and Television. In FM the frequency of the carrier wave is varied within a fixed range at a rate corresponding to the frequency of a sound signal. This form of modulation, p...

• Genética - ciencias de la naturaleza.

  5 HERENCIA CUANTITATIVA Los caracteres que se expresan como variaciones en cantidad o extensión, como el peso, la talla o el grado de pigmentación, suelen depender de muchos genes, así comode las influencias del medio. Con frecuencia, los efectos de genes distintos parecen ser aditivos, es decir, parece que cada gen produce un pequeño incremento o descensoindependiente de los otros genes. Por ejemplo, la altura de una planta puede estar determinada por una serie de cuatro genes: A, B, C y D....

• Soil. I INTRODUCTION Soil, the loose material that covers the land surfaces of

  an exchange between plants and the atmosphere, as oxygen diffuses into the soil and is used by roots for respiration. In turn, the resulting carbon dioxide diffusesthrough pore spaces and returns to the atmosphere. This exchange is most efficient in soils with a high degree of porosity. For farmers, gardeners, landscapers, andothers with a professional interest in soil health, the process of aeration—making holes in the soil surface to permit the exchange of air—is a crucial activity. Theburrowi...

• Sistema inmunológico - ciencias de la naturaleza.

  Las citoquinas son compuestos solubles, responsables en gran parte de la regulación de la respuesta inmunológica. Si son segregadas por los linfocitos, reciben el nombrede linfoquinas; si son segregadas por los monocitos, se denominan monoquinas. Algunas citoquinas amplifican o incrementan una respuesta inmunológica que está encurso, otras hacen que las células proliferen, y otras pueden suprimir una respuesta inmunológica en funcionamiento. El sistema inmunológico, al igual que otros sistemasco...

• Computer.

  which can activate computer commands in conjunction with voice recognition software. “Tablet” computers are being developed that will allow users to interact with theirscreens using a penlike device. E The Central Processing Unit Information from an input device or from the computer’s memory is communicated via the bus to the central processing unit (CPU), which is the part of the computerthat translates commands and runs programs. The CPU is a microprocessor chip—that is, a single piece of sil...

• Hardware (computer).

  Magnetic tape drives use magnetic tape similar to the tape used in VCR cassettes. Tape drives have a very slow read/write time, but have a very high capacity; in fact,their capacity is second only to hard disk drives. Tape drives are mainly used to back up data. Compact disc drives store information on pits burned into the surface of a disc of reflective material ( see CD-ROM). CD-ROMs can store up to 737 megabytes (MB) of data. A Compact Disc-Recordable (CD-R) or Compact Disc-ReWritable (CD-RW)...

• History of Chemistry - chemistry.

  even better distillation apparatus than the Arabs had made and to condense the more volatile products of distillation. Among the important products obtained in thisway were alcohol and the mineral acids: nitric, aqua regia (a mixture of nitric and hydrochloric), sulfuric, and hydrochloric. Many new reactions could be carried outusing these powerful reagents. Word of the Chinese discovery of nitrates and the manufacture of gunpowder also came to the West through the Arabs. The Chinese atfirst use...

• Bicycle.

  narrow as possible to minimize weight and interference with pedaling. F Specialty Bicycles Many other types of bicycles are designed for special purposes. Although not as common as standard single-rider racing, touring, mountain, or recreational bicycles,they nonetheless have significant niches. Recumbent bicycles are bicycles on which the rider sits upright as if in a chair, with legs and feet stretched out in front. Because they support the rider’s lower back,recumbents allow the rider far mo...

• Hardware - ciencia y tecnologia.

  Algunos dispositivos se utilizan para varios fines diferentes. Por ejemplo, los disquetes también pueden emplearse como dispositivos de entrada si contienen informaciónque el usuario informático desea utilizar y procesar. También se pueden utilizar como dispositivos de salida si el usuario quiere almacenar en ellos los resultados de sucomputadora. 5 CONEXIONES DEL HARDWARE Para funcionar, el hardware necesita unas conexiones materiales que permitan a los componentes comunicarse entre sí e in...

• Dark Matter - astronomy.

  observed, and the measured frequency of such events has placed limits on how much dark matter can take the form of MACHOs. From the observations that have beenmade by astronomers, it is now known that MACHOs cannot be the dominant constituent of dark matter. There are simply not enough such gravitational lenses. Physicists suspect that a more exotic form of cold dark matter must exist. This form is not baryonic. Like neutrinos, this form barely interacts with ordinary matter, butis some type of...

• Air - chemistry.

  lighting systems, fertilizers, and semiconductors (substances used to make the chips in computers, calculators, televisions, microwave ovens, and many other electronicdevices). A Oxygen More than half of the oxygen produced in the United States is used by the steel industry, which injects the gas into basic oxygen furnaces to heat and produce steel(see Iron and Steel Manufacture: Basic Oxygen Process ). Metalworkers also combine oxygen with acetylene to produce high-temperature torch flames th...

• Automobile.

  Electric motors have been used to power automobiles since the late 1800s. Electric power supplied by batteries runs the motor, which rotates a driveshaft, the shaftthat transmits engine power to the axles. Commercial electric car models for specialized purposes were available in the 1980s. General Motors Corporation introduced amass-production all-electric car in the mid-1990s. Automobiles that combine two or more types of engines are called hybrids. A typical hybrid is an electric motor with ba...

• Comparative Anatomy.

  In comparing two species, anatomists have to be careful to differentiate between homologous structures, which are ones that have evolved from a shared ancestor, andanalogous structures, which have developed from different origins. Homologous structures are built on the same underlying plan. A human arm, a bat’s wing, and awhale’s flipper look quite different from the outside, but the bones inside reveal that these limbs all have the same basic structure. Analogous structures, by contrast,often l...

• Sistema inmunológico - ciencias de la naturaleza.

  Las citoquinas son compuestos solubles, responsables en gran parte de la regulación de la respuesta inmunológica. Si son segregadas por los linfocitos, reciben el nombrede linfoquinas; si son segregadas por los monocitos, se denominan monoquinas. Algunas citoquinas amplifican o incrementan una respuesta inmunológica que está encurso, otras hacen que las células proliferen, y otras pueden suprimir una respuesta inmunológica en funcionamiento. El sistema inmunológico, al igual que otros sistemasco...

• Sangre - ciencias de la naturaleza.

  Leucocito granulosoLos glóbulos blancos presentes en la sangre incluyen los leucocitos granulosos y los no granulosos. Los leucocitos granulososrepresentados aquí son células polimorfonucleares que tienen un aspecto granular, de ahí su nombre común.Andrew Syred/Science Photo Library/Photo Researchers, Inc. Las células o glóbulos blancos de la sangre son de dos tipos principales: los granulosos, con núcleo multilobulado, y los no granulosos, que tienen un núcleo redondeado.Los leucocitos granulos...

• Sistema de Posicionamiento Global 1 INTRODUCCIÓN Sistema de Posicionamiento Global Puesta en órbita de un satélite Navstar de Sistema de Posicionamiento Global (GPS) mediante cohetes Delta.

  satélites desde Cabo Cañaveral, en Florida, Estados Unidos. Los satélites GPS se desplazan en órbitas circulares a 17.440 km de altitud, invirtiendo 12 horas en cada una delas órbitas. Éstas tienen una inclinación de 55° para asegurar la cobertura de las regiones polares. La energía la proporcionan células solares, por lo que los satélites seorientan continuamente dirigiendo los paneles solares hacia el Sol y las antenas hacia la Tierra. Cada satélite cuenta con cuatro relojes atómicos. La divis...

• Putrefacción y descomposición - ciencias de la naturaleza.

  5 DESCOMPOSICIÓN Y ALIMENTO La descomposición por microorganismos afecta también a la economía industrial. Ciertos productos alimenticios, como el queso y el yogur, se forman gracias a la actividadde microorganismos específicos, pero el resultado se degrada rápidamente cuando el proceso se ve contaminado por otros microbios. Asimismo, la colonización microbianade los alimentos altera la consistencia, el olor y el sabor y los hace menos apetitosos. El crecimiento de determinados organismos duran...

• Computer Security.

  might deny usage to legitimate users, and they ensure that information received from an outside source is expected and does not contain computer viruses. VII INTRUSION DETECTION SYSTEMS Security software called intrusion detection systems may be used in computers to detect unusual and suspicious activity and, in some cases, stop a variety of harmfulactions by authorized or unauthorized persons. Abuse and misuse of sensitive system and application programs and data such as password, inventory,...

• Color I INTRODUCTION Color © Microsoft Corporation.

  The colors that absorb light of the additive primary colors are called subtractive primary colors. They are magenta (purplish-pink), which absorbs green; yellow, whichabsorbs blue; and cyan (light greenish-blue), which absorbs red. Thus, if a green light is thrown on a magenta pigment, the eye will perceive black. These subtractiveprimary colors are also called the pigment primaries. They can be mixed together in varying amounts to match almost any hue. If all three are mixed in about equalamoun...

• Programming Language.

  Logic languages use logic as their mathematical base. A logic program consists of sets of facts and if-then rules, which specify how one set of facts may be deducedfrom others, for example: If the statement X is true, then the statement Y is false. In the execution of such a program, an input statement can be logically deduced from other statements in the program. Many artificial intelligence programs are writtenin such languages. IV LANGUAGE STRUCTURE AND COMPONENTS Programming languages use...

• Encéfalo - ciencias de la naturaleza.

  que conectan estos dos hemisferios y transfieren información de uno a otro. La corteza cerebral presenta una capa superficial denominada sustancia gris, de unos 2 o 3 mm de espesor, formada por capas de células amielínicas (sin vaina de mielinaque las recubra) que envuelven una sustancia interior de fibras mielínicas (con vaina blanca) denominada sustancia blanca. Las fibras mielínicas unen la corteza cerebralcon otras partes del cerebro: la parte anterior del cerebro con la posterior, las difer...

• Astrobiology - astronomy.

  water to help reactions along. American chemists Stanley Miller and Harold Urey tested part of Oparin and Haldane’s hypothesis in the early 1950s by simulating conditions of the early Earth. In whathas become known as the Miller-Urey experiment, the two scientists connected two flasks with a loop of glass tubing that allowed the gases to pass between the flasks.They filled the upper flask with methane, ammonia, and hydrogen—components thought to have been in the early atmosphere. They filled the...

• Virus (life science) - biology.

  RNA into DNA earned them their name because this process is the reverse of the usual transfer of genetic information, from DNA to RNA.) The DNA form of theretrovirus genome is then integrated into the cellular DNA and is referred to as the provirus. The viral genome is replicated every time the host cell replicates its DNA and is thus passed on to daughter cells. Hepatitis B virus can also transcribe RNA to DNA, but this virus packages the DNA version of its genome into virus particles. Unlike...

• Airplane.

  For example, the Anglo-French Concorde, a commercial supersonic aircraft, was generally limited to over-water routes, or to those over sparsely populated regions ofthe world. This limitation impacted the commercial viability of the Concorde, which ended its regular passenger service in October 2003. Designers today believe theycan help lessen the impact of sonic booms created by supersonic airliners but probably cannot eliminate them. One of the most difficult practical barriers to supersonic fl...

• Global Warming.

  some of the warming influence of increasing greenhouse gases. A1 Carbon Dioxide Carbon dioxide is the second most abundant greenhouse gas, after water vapor. Carbon dioxide constantly circulates in the environment through a variety of naturalprocesses known as the carbon cycle. It is released into the atmosphere from natural processes such as eruptions of volcanoes; the respiration of animals, whichbreathe in oxygen and exhale carbon dioxide; and the burning or decay of plants and other organic...

• Análisis químico - ciencia y tecnologia.

  Análisis cualitativo: marcha analíticaEl análisis cualitativo es un método para identificar una sustancia desconocida pasando muestras de la misma por una serie de análisisquímicos. La marcha analítica se basa en reacciones químicas conocidas, de forma que cada producto químico añadido analiza uncatión específico. Si se produce la reacción prevista, significa que el catión está presente. Si no se produce, el analista pasa alsiguiente catión.© Microsoft Corporation. Reservados todos los derechos....

• Redes de comunicación - geografía.

  6.2 Tecnología de objetos Otro de los enfoques para la construcción de los sistemas parte de la hipótesis de que deberían estar compuestos por elementos perfectamente definidos, objetosencerrados, definidos y materializados haciendo de ellos agentes independientes. La adopción de los objetos como medios para la construcción de sistemas informáticos hacolaborado a la posibilidad de intercambiar los diferentes elementos. 6.3 Sistemas abiertos Esta definición alude a sistemas informáticos cuya ar...

• Redes de comunicación - ciencia y tecnologia.

  6.2 Tecnología de objetos Otro de los enfoques para la construcción de los sistemas parte de la hipótesis de que deberían estar compuestos por elementos perfectamente definidos, objetosencerrados, definidos y materializados haciendo de ellos agentes independientes. La adopción de los objetos como medios para la construcción de sistemas informáticos hacolaborado a la posibilidad de intercambiar los diferentes elementos. 6.3 Sistemas abiertos Esta definición alude a sistemas informáticos cuya ar...

• Partículas elementales - ciencia y tecnologia.

  C y D con momentos pC y pD. Llamemos R a esta reacción: A + B → C + D (R) Si las partículas A y B con momentos - pA y -pB producen las partículas C y D con momentos - pC y -pD con la misma probabilidad que R, significa que la reacción es invariante bajo paridad ( P). 5.3 Simetría de conjugación de carga (C) Para ilustrar el principio de simetría de conjugación de carga emplearemos la misma reacción R. Si se sustituyen las partículas A, B, C y D por sus antipartículas Ā, ,  y...

• Cambios en la materia - (exposé gratuit en espagnol).

• Optics I INTRODUCTION Mirage Mirages appear because differences in air temperature cause light rays from an object to take different paths to a viewer's eye.

  Refraction of Light by DiamondsThe brilliance of diamonds is due to their high refractive index, a measure of how strongly a transparent material bendslight rays. The skill of the gem-cutter lies in angling the facets of the stone so that each light ray entering it is reflectedmany times before it emerges again.Spencer Grant/Photo Researchers, Inc. The amount of light reflected depends on the ratio of the refractive indexes for the two media. The plane of incidence contains the incident ray and...

• Aparato digestivo - ciencias de la naturaleza.

  La parte más importante de la digestión tiene lugar en el intestino delgado: aquí, la mayoría de los alimentos sufren una hidrólisis y son absorbidos. El material predigeridoque proporciona el estómago es objeto de la acción de tres líquidos: el líquido pancreático, la secreción intestinal y la bilis. Estos líquidos neutralizan el ácido gástrico con loque finaliza la fase gástrica de la digestión. El líquido pancreático penetra en el intestino delgado a través de varios conductos ( véase Páncre...

• Proteína - ciencias de la naturaleza.

  Estructura secundaria, terciaria y cuaternaria de una proteínaLas interacciones entre las moléculas que forman una proteína, son la causa de que la cadena polipeptídica enrollada (izquierda) sepliegue para dar una estructura tridimensional (centro), que puede unirse a otras para formar grandes proteínas complejas (derecha).© Microsoft Corporation. Reservados todos los derechos. El nivel más básico de estructura proteica, llamado estructura primaria, es la secuencia lineal de aminoácidos que está...

• Central Processing Unit.

  Development of the computer chip started in 1958 when Jack Kilby of Texas Instruments demonstrated that it was possible to integrate the various components of aCPU onto a single piece of silicon. These computer chips were called integrated circuits (ICs) because they combined multiple electronic circuits on the same chip.Subsequent design and manufacturing advances allowed transistor densities on integrated circuits to increase tremendously. The first ICs had only tens of transistorsper chip com...

• Metabolism (chemistry) - biology.

  nearly perfect balance. Although much remains to be revealed about metabolic processes, biochemists now agree that regulatory, or rate-limiting, enzymes figure largely in the reactionsinvolved ( see Enzyme). Affecting metabolic pathways at the earliest steps, each enzyme molecule has a specific, or active, site that matches, or “fits,” its particular substrate—the compound with which the enzyme forms a product. The precision with which rate-limiting enzymes and substrates join to set off a parti...