Personal Theory Essay Example | Topics and Well Written Essays - 750 words

Personal Theory - Essay Example , 1986, 115-31) Feminist theory takes the position that the portrayal of the damsel in distress has a profound view on the self-perception as children tend to emulate the characteristics of their favorite characters in children’s literature and attempt to subscribe to their respective character traits. (Zipes, 1989, 185-200) Feminist theory takes the position that the damsel in distress portrays a view of human nature that perpetuates an entirely sexist view of human nature.(Kramer and Moore, 2001) The underlying message is that the female in distress does not have the ability to cope on her own and is dependent upon a males assistance for relief. The view of human nature in this distinction between female and male characterization is exemplified in Cinderella where the damsel in distress is rescued by a Prince Charming who holds out the promise of marriage, status, wealth and happiness. The heroine is helpless and powerless and cannot find redemption without male interference. Sleeping Beauty and Snow White are similar in their respective approaches to this view of human nature in that the heroine is passive and dependant upon the strong, rich and powerful male for redemptive value. Beauty and The Beast puts forward the strong male/weak female view of human nature in a different way. In this fairy tale, the male is aggressive, cruel and punishing and is eventually tamed by the self-sacrificing, beautiful female victim. The female heroine eventually comes to the realization that the male’s cruelty and aggression were all facades for his underlying love for the female and his actual cruel and violent outbursts were merely manifestations of his love for her. (Coward, 1984, 189) Girls who read these Fairy Tales obviously form a distorted view of their perceptions of the female’s role in society. Feminist theory advocates that girls tend to idealize these feminine traits and strive to emulate them. The role of the councilor is to help women who have

Unconscious mind Essay Example for Free

Unconscious mind Essay The word personality originates from the Latin word â€Å"persona† which means mask. From the modern meaning of mask, it means a cover used for disguise. However from the ancient Latin-speaking world, the word is used not to conceal something but to typify or represent a character in theater plays. Thus, personality is what differentiates or distinguishes a person. It is a mask that sets an individual apart from others. For a more detailed description of personality, it is defined as the sum total of the qualities and characteristics of a person as shown in her manner of walking, talking, dressing, and her attitudes, interests, and ways of reacting to other people.   Consequently, to make things simpler and to quote from Glen Allsopp, a popular internet blogger, personality is a set of qualities that make a person distinct from another. Psychoanalysis was pioneered by Sigmund Freud. This perspective believes that there are three levels of awareness or divisions of the mind namely conscious, preconscious and unconscious. Freud represented these levels of awareness through an iceberg. The part of the iceberg visible above the surface is the conscious mind. Just below the surface is the preconscious mind, anything that is not yet part of the conscious mind. Hidden deep below the surface is the unconscious mind, feelings, memories, thoughts, and urges that cannot be easily brought into consciousness. The unconscious can be revealed in dreams and Freudian slips (or slip of the tongue is a verbal or memory mistake believed to be linked with the unconscious mind). In addition, according to Freud, there are three parts of personality called as id, ego and superego. The id works on the pleasure principle. Its goal is instant gratification and satisfaction from our primitive drives related to hunger, sex, aggression, and irrational impulses. The ego works on the reality principle. It protects the person against the immediate gratification of the id. Conscious awareness resides in the ego, although not all of the operations of the ego are conscious. The ego brings the person down to what is real. As an example, when a person is hungry or is sexually  driven, the desire can only be satisfied at the right place and at the right time. The ego controls the person’s actions and allows for higher level cognitive skills. The superego, on the other hand, is the moral center of personality, containing the ego ideal and the conscience, and is the source of moral anxiety. The superego would create perfectionist and civilized individuals that are incapable of compromising what life requires. While the id would create pleasure-seeking individuals whose main goal is to satisfy every desire without delay. The ego balances the person as it compromises what the id desires in accordance to the superego. Carl Gustav Jung believed that there was not only a personal unconscious, as described by Freud, but a collective unconscious as well. This collective unconscious served as a form of psychological inheritance. It contains all of the knowledge and experiences we share as a species. The collective unconscious contains archetypes or models of people, behaviors, and personalities. These archetypes are innate, universal, and hereditary. These are unlearned and function to organize how we experience certain things. The four major archetypes according to Jung are: the self, the shadow, the anima or animus, and the persona. The self is the unification of the consciousness and unconsciousness wherein various aspects of personality are integrated. T he shadow exists as part of the unconscious mind and is described as the darker side of the psyche. It is composed of weaknesses, repressed ideas, desires, instincts, and short comings. The anima is the feminine image in the male psyche while the animus is the male image in the female psyche. It is represented as the â€Å"true self† rather than the image a person projects to others. Lastly, the persona is how we project ourselves to the world. It is like our social mask that we wear for different situations and groups. It shields the ego from negative images. Archetypes are not limited to the four types previously mentioned nor are fixed. Other archetypes that Jung described are: the father (authority figure), the mother (nurturing and comforting), the child (longing for innocence), the hero (champion, defender), and the trickster (liar, deceiver) among others. Psychiatrist Alfred Adler proposed feelings of inferiority as the driving force behind personality and developed the birth order theory. Firstborn children with younger siblings feel inferior once those younger siblings get all the attention and often overcompensate by becoming overachievers. Middle children feel superior over the dethroned older child while dominating younger siblings and they tend to be very competitive. Younger children feel inferior because they are not allowed the freedom and responsibility like those of the older children. Frank Sulloway, another theorist proposed that birth order has a profound effect on one’s personality. Firstborns are more dominant, less open to new ideas, and more conscientious than later-born children. Consequently, later-born children are more open and rebellious.

The Stages Of The Refrigeration Cycle Engineering Essay

The Stages Of The Refrigeration Cycle Engineering Essay The second law of thermodynamics is described as the most fundamental law of science (Khemani, 2008). It is fundamental in the sense that it can be used to explain not only refrigerators and heat engines but highly advanced phenomena such as the big bang. It has been put aptly in the words of Classius as it is impossible for a process to occur that has the sole effect of removing a quantity of heat from an object at a lower temperature and transferring this quantity of heat to an object at a higher temperature (Mortimer, 2008). This essentially means that heat cannot flow spontaneously from a cooler to a hotter body if nothing else happens (Mortimer, 2008) i.e. there needs to be an external agency to effect the change. In kitchen refrigerators, the closed box inside is able to be kept cool by the removal of heat from the inside of the box and depositing it on the outside. Because the heat will not move freely from the cold inside to the hot outside, as by the second law, it is important for it to be made to do so, this is done by using an intermediate fluid (Littlewood, 2004) which absorbed heat on the inside. This intermediate fluid is known as a refrigerant and carries the heat outside of the box whereby it it released into the air as heat as shown in (Littlewood, 2004). Figure 1 the flow of heat within the refrigerator a schematic (Littlewood, 2004) The fluid circulates within the pipe which passes in and out and can be found at the back of the refrigerator. It is kept by using a compressor (which uses electricity from the home) and allows it to work effectively without violating the second law of motion. (Littlewood, 2004) THE FIRST LAW Refrigerator takes in energy from a region that needs to be cooled (or kept cold) and deposits this heat energy into some other region that is outside of the refrigerator. In order to work, there has to be some mechanism in place, where the work done by a compressor and its electric motor is utilized. Using the First Law of Thermodynamics we can write: (Littlewood, 2004) Figure 2 the first law of thermodynamics (Littlewood, 2004) QC   QH  = -W Where: Qc energy or heat of the cold system QH = energy or heat of the hot system W = work done Since work is done on the refrigerator by another device (the compressor), rather than by the refrigerator itself, the work is done is deemed negative because of sign conventions. This is part of the first law (Littlewood, 2004). Suppose that 2.4 MJ of work is used to remove 5.2 MJ of heat from the inside of the refrigerator, then an amount of heat QH  = QC  + W = 5.2 MJ + 2.4 MJ = 7.6 MJ must be added to the kitchen. The refrigerator is termed as a closed system and it possesses a constant composition: U = U + (à ¢Ã‹â€ Ã¢â‚¬Å¡U/à ¢Ã‹â€ Ã¢â‚¬Å¡V) T dV U = U + (à ¢Ã‹â€ Ã¢â‚¬Å¡U/à ¢Ã‹â€ Ã¢â‚¬Å¡T) V dT U = U + (à ¢Ã‹â€ Ã¢â‚¬Å¡U/à ¢Ã‹â€ Ã¢â‚¬Å¡V) T dV + (à ¢Ã‹â€ Ã¢â‚¬Å¡U/à ¢Ã‹â€ Ã¢â‚¬Å¡T) T dT dU (à ¢Ã‹â€ Ã¢â‚¬Å¡U/à ¢Ã‹â€ Ã¢â‚¬Å¡V) T dV + (à ¢Ã‹â€ Ã¢â‚¬Å¡U/à ¢Ã‹â€ Ã¢â‚¬Å¡T) V dT According to Bain (2010), there are four basic parts to any refrigerator: Compressor Heat Expansion valve Refrigerant The exchanging pipes are a coiled set of pipes that is placed strategically outside of the unit. The refrigerant as will be discussed later on is a liquid that has the ability to evaporate efficiently so that inside the refrigerator is kept cooled. (Bain, 2010) A gas can be cooled by adiabatic expansion if the process is enthalphic. The gas expands through a process barrier from one constant pressure to the next and the temperature difference in observed. Insulation of the system made the process adiabatic. The result is that a lower temperature was absorbed on the on a low pressure side and the change in the temperature is proportional to the change in pressure. (Bain, 2010)  Ã¢â‚¬Å¾T  µ  Ã¢â‚¬Å¾P Figure 3 schematic of a domestic refrigerator (Bain, 2010) When an energy |qc| is removed from a cool source at some temperature Tc, and then deposited in a warmer sink at a temperature Th, the change in entropy is: (Atkins dePaula, 2006) Atkins dePaula (2006) also indicated that the process is not spontaneous because the entropy generated in the warm sink is not enough to overcome the loss of entropy from the cold souce. And because of this more energy needs to be added to the stream that enters the warm sink to generated the entropy required by the system. They further indicated that the outcome is expressed as the coefficient of performance, c: The less the work required to achieve a given transfer, the greater the coefficient of performance and the more efficient the refrigerator (Atkins dePaula, 2004). Because |qc| is removed from the cold source, the work |w| is added to the energy stream, the energy deposited as the heat in the hot sink |qh| = |qc| + |w|. Therefore, From: We can have an expression in terms of the temperature alone, which is possible if the transfer is performed reversibly (Atkins dePaula, 2006): Where: c = thermodynamic optimum coefficient of temperature Tc = temperature of the cold sink Th = temperature of the hot sink For a refrigerator, it important that a very low coefficient of performance. For a refrigerator withdrawing heat from ice cold water (Tc = 273 K) in a typical environment (Th = 293K), c = 14. As an example, to remove 10 kJ (enough to freeze 30 g of water), requires transfer of atleast 0.71 kJ as work. (Atkins dePaula, 2005) The work to maintain a low temperature is very important when designing refrigerators. No thermal insulation is perfect, so there is always some form of energy flowing as heat into a specific sample at a rate that is proportional to the temperature difference. (Atkins and de Paula, 2006). Figure 4 (a) the flow of energy as heat from a cold source to a hot sink is not spontaneous. As can be seen, the entropy increase of the hot sink is smaller than the entropy increase of the cold source, so there is a net decrease in entropy (Atkins dePaula, 2006). (b) The process becomes feasible if work is provided to add to the energy stream. Then the increase in entropy of the hot sink can be made to cancel the entropy of the hot source (Atkins dePaula, 2006) he rate at which energy leaks happen is written as: Where: A = a constant that depends on the size of the sample and details of the simulation Tc = temperature of the cold sink Th = temperature of the hot sink The minimum power, P, required to maintain the original temperature difference by pumping out that energy by heating the surroundings is: As can be seen the power increases as the square of the temperature difference (Th Tc). THE REFRIGERATION CYCLE The gas is pumped continuously at a steady pressure, the heat exchanger (which brings the required temperature) and then through a porous plug inside container that is thermally insulated. A phase change heat pump uses a liquid that has a low boiling point to transfer heat from a cooler area to a warmer one, in refrigerators. This heat pump is the most commonly used in domestic refrigerators. It employs a liquid, known as a refrigerant which has a low boiling point. The liquid requires energy (called latent heat) to evaporate, and it drains that energy from its surroundings in the form of heat. When the vapor condenses again, it releases the energy (in the form of heat). A refrigerant is a compound used in a heat cycle that undergoes a phase change from a gas to a liquid and back. Latent heat describes the amount of energy in the form of heat that is required for a material to undergo a change of phase (also known as change of state). Two latent heats are typically described. (Bamb ooweb, 2009)For other uses, see CFC (disambiguation). The pump operates a cycle in which the refrigerant changes state from its liquid form to the vapour form and vice versa. This process occurs repeatedly and I known as the refrigeration cycle. In this cycle, the refrigerant condenses and heat is released in one point of the cycle. It is the boiled (or evaporated) so that it absorbs heat in another point of the cycle. The widely used refrigerant is hydro fluorocarbon (HFC) known as R-134a (1, 1, 1, 2 tetrafluoroethane) and CCl2F2 (dichlorodifluoromethane). Other substances such as liquid ammonia, propane or butane, are be used but because of their highly flammable nature, they are disregarded as a good refrigerant. 1930 (MCMXXX) was a common year starting on Wednesday (link is to a full 1930 calendar). (Bambooweb, 2009)For other uses, see CFC (disambiguation). In the refrigerator the fluid used (e.g. CCl2F2 ) fluid is liquefied by compression then vaporized by sudden expansion which gives a cooling effect. The compressor, in itself does not create a cooling effect directly, as might be expected. The cooling effect is created when the refrigerant absorbs the heat from the cooled space. This is accomplished with a heat exchanger. (Bambooweb, 2009)For other uses, see CFC (disambiguation). A heat exchanger is a device built for efficient heat transfer from one fluid to another, whether the fluids are separated by a solid wall so that they never mix, or the fluids are directly contacted. The refrigeration cycle can be divided in two parts: The liquefaction stage The evaporation stage LIQUEFACTION STAGE The refrigerant vapour undergoes recycling by itself into the liquid form by the extraction of heat from a vapour at a higher temperature. The refrigerant is compressed by the compressor where a low pressure and low temperature condition is created. This is accomplished by an evaporating coil. During the compression process, the vapour of the refrigerant undergoes a temperature change (as an effect of the compression process). Additionally, the work of compression to create the high temperature and pressure vapour also contributes to the temperature change experienced by the vapour. The condenser that is located where the temperature is higher (i.e. the higher temperature heat sink) collects the vapour. Heat is then removed from the refrigerant and in lieu of this it condenses to its liquid state, hence the name for the condenser. Using the Joule-Thompson coefficient: For a perfect gas  µ = 0 Cp + Cv = (à ¢Ã‹â€ Ã¢â‚¬Å¡H/à ¢Ã‹â€ Ã¢â‚¬Å¡T)p (à ¢Ã‹â€ Ã¢â‚¬Å¡U/à ¢Ã‹â€ Ã¢â‚¬Å¡T)p Introducing: H = U + pV = nRT into the first term: Cp Cv = (à ¢Ã‹â€ Ã¢â‚¬Å¡U/à ¢Ã‹â€ Ã¢â‚¬Å¡T)p + nR (à ¢Ã‹â€ Ã¢â‚¬Å¡U/à ¢Ã‹â€ Ã¢â‚¬Å¡T)p = nR EVAPORATION STAGE As the refrigerant leaves the condenser, the next part of the cycle begins. This is accomplishe when a high temperature and high pressure liquid passes through a metering device that is found within the refrigeration. The valve allows a specific quantity of liquid coolant to pass into the evaporation chamber. Evaporation chambers are relatively low pressure and this encourages coolant evaporation. Newly evaporated coolant is drawn though the cooling coils (typically a fan is used to blow air over the coils). Thus, the evaporative process produces the cooling effect. The refrigerant then is pulled to the compressor in the suction line where it will be compressed into a high temperature, high pressure gas and sent to the external heat sinking coils. Capillary action or capillarity is the ability of a narrow tube to draw a liquid upwards against the force of gravity. A refrigerator pumps heat up a temperature gradient. The cooling efficiency of this operation depends on the amount of heat extracted from the cold temperature reservoir (the freezer compartment), , and the work needed to do so. Since a practical refrigerator operates in a cycle to provide a continuous removal of heat, for the cycle. Then, by the conservation of energy (or first law), , where is the heat ejected to the high temperature reservoir or the outside. The measure of a refrigerator performance is defined as the efficiency expressed in terms of the coefficient of performance (). Since the purpose is to extract the most heat () per unit work input (), the coefficient of performance for a refrigerator, , is expressed as their ratio: Where, the conservation relationship given above is used to express the work in terms of heat. For normal refrigerator operation, the work input is less than the heat removed, so the is greater than 1. Refrigerators are commonly referred to as heat pumps of more specifically a it is a reversible heat pump because they basically pump heat. Figure 5 A simple stylized diagram of a heat pumps vapor-compression refrigeration cycle: 1)  condenser, 2)  expansion valve, 3)  evaporator, 4)  compressor. Opening a food refrigerator or freezer heats up the kitchen rather than cooling it because its refrigeration cycle rejects heat to the indoor air. This heat includes the compressors dissipated work as well as the heat removed from the inside of the appliance. The COP for a heat pump in a heating or cooling application, with steady-state operation, is: Where: ΆQcool is the amount of heat extracted from a cold reservoir at temperature Tcool, ΆQhot is the amount of heat delivered to a hot reservoir at temperature Thot, ΆA is the compressors dissipated work. EFFICIENCY The efficiency of a refrigerator (known as the coefficient of performance, COP) is defined as   For example, if 20 MJ are removed from the inside of the refrigerator by doing 7.5 MJ of work, then the coefficient of performance is equal to 20/7.5 = 2.67. SUMMARY OF THERMODYNAMIC OF A REFRIGERATOR AFTER ONE CYCLE Change in internal energy = 0 Change in heat is > 0 Total work > 0 Total volume change = 0 Change in Gibbs free energy = 0 Entropy change of the system = 0 Entropy change of the universe > 0

The Life of Christopher Marlowe :: Free Essays Online

The Life of Christopher Marlowe Christopher Marlowe, also known as "Kind Kit" and "The Muses' Darling," is most famously known for being a pioneer in English drama. Introducing blank verse, villain-heroes, and revenge dramas to the stage, Marlowe had a huge influence on other playwrights of that time including William Shakespeare. Marlowe was born in Canterbury in 1564 to John Marlowe, a shoemaker, and Katherine Arthur, a Dover native (Henderson 7). On February 26th that year he was baptized at St. George’s Church in Canterbury (8). During the Elizabethan era, it was important that bright young boys receive proper education. A local philanthropist would usually pay tuition for a boy whose family could not afford it. When Marlowe was accepted into the King’s School, usually for sons of wealthy men, Sir Roger Manwood, a local philanthropist, allegedly paid for his education. When he died, Marlowe wrote a Latin elegy for him ("The Life"). While he was at King’s School, Marlowe studied religious instruction, learned Latin grammar, and Latin and Greek Literature. He was also well studied in ancient and modern history and was encouraged to write Latin poetry and perform plays in Latin and Greek. Upon finishing King’s School, he received a Matthew Parker Scholarship to Corpus Christi College in Cambridge, where he attended from 1580-1587 to further his studies and demonstrate a â€Å"mastery of Latin syntax and grammar.† He received his BA in 1584 to become ‘Dominus’ Marlowe ("The Life"). During the Elizabethan era, many of the best college students were recruited into the Secret Service to protect the Queen and her government. In 1584, after receiving his BA, Marlowe was recruited into the Queen’s Secret Service by Sir Francis Walshingham, England’s Secretary of State. During his time as an agent he gained respect from the Queen and her court, getting recognized as a talented writer. His political insight was â€Å"reflected in his political play about the turmoil in France, The Massacre at Paris† ("The Life"). Marlowe’s most important assignment was uncovering the Babington Plot, aimed at the Queen’s assassination and the assassination of her chief ministers in order to place Mary, Queen of Scots, as England’s Catholic queen. The Life of Christopher Marlowe :: Free Essays Online The Life of Christopher Marlowe Christopher Marlowe, also known as "Kind Kit" and "The Muses' Darling," is most famously known for being a pioneer in English drama. Introducing blank verse, villain-heroes, and revenge dramas to the stage, Marlowe had a huge influence on other playwrights of that time including William Shakespeare. Marlowe was born in Canterbury in 1564 to John Marlowe, a shoemaker, and Katherine Arthur, a Dover native (Henderson 7). On February 26th that year he was baptized at St. George’s Church in Canterbury (8). During the Elizabethan era, it was important that bright young boys receive proper education. A local philanthropist would usually pay tuition for a boy whose family could not afford it. When Marlowe was accepted into the King’s School, usually for sons of wealthy men, Sir Roger Manwood, a local philanthropist, allegedly paid for his education. When he died, Marlowe wrote a Latin elegy for him ("The Life"). While he was at King’s School, Marlowe studied religious instruction, learned Latin grammar, and Latin and Greek Literature. He was also well studied in ancient and modern history and was encouraged to write Latin poetry and perform plays in Latin and Greek. Upon finishing King’s School, he received a Matthew Parker Scholarship to Corpus Christi College in Cambridge, where he attended from 1580-1587 to further his studies and demonstrate a â€Å"mastery of Latin syntax and grammar.† He received his BA in 1584 to become ‘Dominus’ Marlowe ("The Life"). During the Elizabethan era, many of the best college students were recruited into the Secret Service to protect the Queen and her government. In 1584, after receiving his BA, Marlowe was recruited into the Queen’s Secret Service by Sir Francis Walshingham, England’s Secretary of State. During his time as an agent he gained respect from the Queen and her court, getting recognized as a talented writer. His political insight was â€Å"reflected in his political play about the turmoil in France, The Massacre at Paris† ("The Life"). Marlowe’s most important assignment was uncovering the Babington Plot, aimed at the Queen’s assassination and the assassination of her chief ministers in order to place Mary, Queen of Scots, as England’s Catholic queen.

Disk operating system Essay

MS-DOS (Microsoft Disk Operating System) is a single-user, single-tasking computer operating system that uses a command line interface (CLI). †¢ It also works as an interpreter between user and computer. †¢ The term DOS can refer to any operating system, but it is most often used as shorthand for MS-DOS (Microsoft disk operating system). Originally developed by Microsoft for IBM, MS-DOS was the standard operating system for IBM-compatible personal computers. The initial versions of DOS were very simple and resembled another operating system called CP/M. Subsequent versions have became increasingly sophisticated as they incorporated features of minicomputer operating systems. However, DOS is still a 16-bit operating system and does not support multiple users or multitasking. For some time, it has been widely acknowledged that DOS is insufficient for modern computer applications. Microsoft Windows helped alleviate some problems, but still, it sat on top of DOS and relied on DOS for many services. Even Windows 95 sat on top of DOS. Newer operating systems, such as Windows NT and OS/2 Warp, do not rely on DOS to the same extent, although they can execute DOS-based programs. It is expected that as these operating systems gain market share, DOS will eventually disappear. In the meantime, Caldera, Inc. markets a version of DOS called DR-OpenDOS that extends MSDOS in significant ways. †¢ †¢ Components of MS-DOS †¢ MS-DOS consists of four essentials programs and a set of additional utilities. Four main programs are †¢ Boot Record †¢ IO.SYS †¢ MSDOS.SYST †¢ COMMAND.COM What is BOOTing ? †¢ †¢ †¢ It is a process that starts up a computer. It checks for proper functioning of all the peripheral devices attached with the system. It searches for the operating system and, when located, loads it into the main memory. OR When the computer is switched on, the firmware program in Read Only Memory(ROM) also called Basic Input-Output System(BIOS) reads programs and data i.e. Operating System and loads it into memory (RAM). This process is known Bootstrapping(Booting). The OS once loaded takes control of the computer, handles user interaction and executes application programs. BOOTing Sequence During Booting process, computer loads the operating system into its memory. DOS booting involves reading following files into memory namely IO.SYS, MSDOS.SYS, and COMMAND COM. The Basic Input/Output Program (IO.SYS): This program provides interface between the hardware devices and software of the system. It takes care of the keyboard input, character output to monitor, output to printer and time of the day. The File and Disk Manager Program  (MSDOS.SYS) : It contains the file management and the disk buffering management capabilities. It keeps track of all the disk access of an application program and remains permanently in memory. The Command Processor (COMMAND.COM) : It is also called command interpreter. It is the program that displays the system prompt and handles user interface by executing the command typed in by the user using keyboard. The CONFIG.SYS file : This file contains reference to device drivers which are loaded when OS takes control of the computer. This device drivers are required for configuring operating system for running special devices. The AUTOEXEC.BAT file : This is a special batch program that is automatically executed when the system is started. It can be used to define keys, define the path that MS-DOS uses to find files, display messages on the screen etc. It will be executed only if it exists in the root directory or the diskette from which the system is loaded. Each time the system is started, MS-DOS executes the commands stored in AUTOEXEC.BAT file. One can run it without restarting the system by typing AUTOEXEC at the command prompt. Warm and COLD Reboot Switching on of the computer from Power off and loading the operating system is called â€Å"Cold Boot†. This generally starts with memory test and chips initialization. There may be case when the computer is already on or has hanged up and we want to reboot the system. This is known as â€Å"Warm Boot† and is done by pressing ctrl+alt+del keys simultaneously or just by pressing â€Å"Reset† button on the system. Naming DOS directories and files †¢ †¢ †¢ †¢ There are two name in DOS and is divided into 2 parts. 1. Primary Name 2. Secondary Name or extension. Primary name is separated from the Secondary name/ extension with the help of a dot (.) look at the following example. Example: ENVOICE. TXT †¢ †¢ †¢ †¢ Primary name can be from 1 to 8 characters long. Secondary name contains 3 or less than 3 characters and is optional. The extension tells DOS about what kind of file it is. A valid Character for naming a file are: from A to Z and the digit 0 to 9 Types of DOS commands †¢ C :> Is known as DOS command prompt, where we give the commands. DOS command divided into 2 parts. 1. Internal Commands or Memory-Resident Commands 2. External Command or Disk-Residence Commands †¢ Any instruction given to the computer to perform a specific task is called command. The DOS has several commands, each for a particular task and these are stored in DOS directory on the disk. The commands are of two types : (a)Internal Commands : These are in built commands of MS-DOS i.e. these are stored in Command interpreter file (COMMAND.COM). These commands reside in the memory as long as the machine is at the system prompt(C:>) level. To use these commands no extra /external file is required. E.g. DATE, TIME, DIR, VER etc. These are also called Memory Resident Commands. These commands are automatically loaded into the computer‟s memory during the booting process. They actually included in the Command.com file. So these commands are executable immediately after getting the DOS prompt. Example: mkdir, cd, rd, copycon etc. (b) External commands : These are separate program (.com) files that reside in DOS directory and when executed behave like commands. An external command has predefined syntax. for e.g. HELP, DOSKEY, BACKUP, RESTORE, FORMAT etc. These are also called Disk-Resident Commands. These commands are meant for special purpose. These are found in separate files on Hard Disk or Floppy Disk, hence they don‟t typically consume valuable memory space. They are loaded into memory only when called. Example: xcopy, move, doskey etc. Microsoft Disk Operating System Introduction to the Operating Systems: An Operating system is software that creates a relation between the User, Software and Hardware. It is an interface between the all. All the computers need basic software known as an Operating System (OS) to function. The OS acts as an interface between the User, Application Programs, Hardware and the System Peripherals. The OS is the first software to be loaded when a computers starts up. The entire application programs are loaded after the OS. Whenever an application needs information it requests the OS which in turn queries the System clock on the motherboard. User interacts with the computer through the OS then OS interprets inputs given by a user through the Keyboard, Mouse or other input device and takes appropriate actions. An Operating System can be of Three Types: Single User MS-Dos, MS-Win 95-98, Win-ME Multi User UNIX, Linux, XENIX Network Novel Netware, Win-NT, Win-2000-2003 1. Single User: If the single user os is loaded in computer’s memory; the computer would be able to handle one user at a time. 2. Multi user: If the multi-user os is loaded in computer’s memory; the computer would be able to handle more than one user at a time. 3. Network: If the network os is loaded in computer’s memory; the computer would be able to handle more than one computer at time. Command Prompt Interface: Operating System provides a text based interface called command prompt. From the command prompt commands can be issued to perform file and disk management and to run program. Results of these commands are presented to the user as text message. C:>The command prompt can be an alphabet followed by one colon (:), one back slash (), one greater than sign (>) and one blinking element called cursor (_). Where C: represents the Drive letter (Current Drive) represents the current folder / Directory > represents the end of the Prompt and _ blinking element (represents the Cursor) Always a cursor position decides that the current typed letter from the keyboard will appear on that position. The operating system (OS) is the first program that must be loaded into the memory of your PC before you can use it for any application. You can start your computer with disk operating system (DOS) or some other operating system such as Windows 95, 97, 98 or Windows NT that might be installed in the Hard disk. In this chapter, we shall discuss the basic facilities available in DOS. Switch to MS-DOS and go through most of the text given in this and the next two chapters. If your computer is running under windows 95/98 or Windows NT, perform the following steps to switch to MS-DOS, otherwise move to section 2.1. ï‚ · Click the start button in the taskbar and press the windows logo key to open the start menu then click programs in the start menu. ï‚ · Windows displays the program submenu. ï‚ · In the program menu click MS-DOS Prompt and your screen displays a window that contains MS-DOS Prompt, such as â€Å"C:windows>_†. ï‚ · If you like you can also restart your computer in MS-DOS mode by using the following steps: o Close any open programs o Click the Start Button in the TaskBar or Press the Windows Logo Key to open the Start Menu. o Click â€Å"restart in MS-DOS Mode† and then click OK. Wait for some time and your PC restarts in MS-DOS Mode. After your PC starts in MS-DOS Mode or window, skip the next section and move to section 2.2. What is a File? In computer terminology, file is a collection of text or data stored on a storage device, such as a Floppy Disk or Hard Disk. If you new to computers, it may sound a bit complicated. Well, a computer file is not much different from a conventional paper file that you must have used, or at least seen being used. Just as you stored different types of documents (invoice, letters, reminders, memos etc.) in conventional files, computer files too store information. File Name Each file is given a name so that it can be referred to later. This name is called Filename. The filename in DOS can be up to eight alpha-numeric characters long. Optionally it can also have a period (.) followed by an extension name. The extension name the up to three characters long. For instance, consider the following filename: REPORT2 PROGRESS.DOC Here REPORT2 is a filename. This filename does not have an extension name – „DOC‟. The use of an extension name in a filename is optional. However, the extension name helps in organizing and identifying a file. For instance „DOC‟ may suggest that it is a document file; and „COM‟ may suggest that is a command file. If you use an extension name with a filename, normally you will have to specify the complete file name, normally you will have to specify the complete file name (i.e. including the extension name) while using it with DOS commands. While naming files, you can use the following characters in filename: A- Z, a- z, 0 – 9, @, #, $, %, ^, &, -, _, { },`, ~,( ) You cannot use other characters, such as coma (,) colon (:), semicolon (;), , , /, etc. in filename. Moreover, you cannot use space in filenames. Some examples of invalid file names are: Filename Reason SALE 2 Contains space PROGRESSER Contains more that eight characters MY, File Contains commas CHAP_01.DOC3 Extension name contains more than 3 characters If you use more than eight characters in the filename or more than three characters in the extension name, DOS may automatically truncate the filename by removing extra characters. Further, some file names, such as COM 1, COM 2, LPT1, com and PRN are reserved by DOS for its own use. Therefore, do not use these names to name your file. Also, remember that all DOS application programs including Word, Excel, WordStar, Bbase III PLUS AND Fox Pro follow the same file naming convention. WHAT IS A Directory? As you know, the storage capacity of the hard disk is usually quite large (10 MB to a few GB). You can store hundreds or even thousands of files in your hard disk. Even the capacity of a floppy disk is large enough to store many files. A directory is nothing but a named section of a storage device, such as hard disk, floppy disk. In other words, to organize file on hard disk or floppy disk, these are divided into various segments (sections), called directories. You can store any number of files in each directory. The directory helps to organise your file in an efficient manner. Using directories in a storage devise is similar to keeping different types of files in an office in separate drawers of a filing cabinet. For instant, Xyz Company may keep all sales files in the first drawer, all purchase files in the second drawer and all employees‟ files in the third drawer of a filing cabinet. In the same way, when XYZ Company computerizes its operation, it may store all sales files in the SALES directory, all purchase files in the PURCHASE directory and all employees‟ files in the EMPOLYEES directory. Similarly, the user Raj Kumar may keep his personal files in the RAJ directory and the secretary of XYZ Company may store the letters in the LETTERS or DOC directory. Like a file name, the directory name can also have up to eight alpha-numeric characters. The directory name can also have and extension name up to 3 characters long. However, normally, the extension name is not used with the directory name. When you start your PC, it usually responds with „C :/>‟ and selects the main or the root directory of drive C. Any file that you create or copy to drive  C is added to this root directory. If you continue to add files in the root directory, after a few days, the root directory will have too many files. This will not only confuse you, it will also make the PC slow. The PC may take too long to locate or open the files if there are too many files in a directory. There for you should try to use directories (and sub directories) in your hard disk DOS always creates a root directory in each story device. You can create new directories in the root directory of the hard disk or floppy disk. You can store files in these directories. Moreover, beside files, each directory can also have directories. Those, the file and directory organization in DOS looks like the roots of a tree, as show in figure 2.1.here, the root directory in drive C contains if you files in two directories – WORD and EXCEL. The WORD directory contains a few files as well as a directory TENDER. Sometimes, the second level directory (TENDER in this case) is called sub-directory. The root directory contains another directory – EXCEL. This directory contains a few files as well as two directories – SALES and EMPLOYEE. Both these directories contain files. At any level in the directory structure, can be created. For example, another directory, say FOXPRO directory may contain files as well as more directories. If you want, you can remove files from any directory or more files to another directory. You can also delete an enter directory. Comments to copy, move, rename and delete files and to create and change directories are discussed letter in this chapter. Additional file and directory comments are discussed in the next chapter.

Free Essays on Star Dust

Star Dust Have you ever wondered how many different objects and particles enter earth’s atmosphere everyday. The earth is growing fatter under continuous microscopic flurry of space specks. The earth gathers 100 tons of space dust everyday. These space particles come from all the over the universe, from the asteroids in the asteroid belt to pieces of distant planets from the dust that was there when our planet was created. By studying these dust particles, astrophysicists say we can learn about our cosmic roots. Cosmic particles are all around us, however, it is near impossible to tell it apart from all the earthly particles in the air. Such things as pollen, pollution, soil, human skin, etc. Not only is space dust hard to see it’s even harder to catch, they are the size of 100 micrometers (Or the width of a hair). To collect space dust scientist have turned to Antarctica. Where there are little to known of earth’s floating particles. The Amundsen-Scott South Pole stat ion draws its drinking water from a well in a cavity of the never-ending ice. As the water is pumped up through a small hole on the surface, the water is heated and shot back down to melt more ice. As the ice melts, it frees the space particles that were in the snowflakes. There was a lot of build up of particles on the well floor. Studying these particles was as easy as throwing a bucket down a hole. Another way dust particles are collected is to attach sticky film to a high altitude aircraft. Once the Astrophysicist have captured the dust, they can determine how fast it entered the earth’s atmosphere thus telling us if it came from a comet, asteroids, or virginal stardust. The Astrophysicist determines the speed of the dust by putting the dust particle in an oven. They rise the temperature until the minerals in the dust particle start to evaporate. If the minerals evaporate at 901 degrees but not at 900 we know that the dust particle was heated to a ma... Free Essays on Star Dust Free Essays on Star Dust Star Dust Have you ever wondered how many different objects and particles enter earth’s atmosphere everyday. The earth is growing fatter under continuous microscopic flurry of space specks. The earth gathers 100 tons of space dust everyday. These space particles come from all the over the universe, from the asteroids in the asteroid belt to pieces of distant planets from the dust that was there when our planet was created. By studying these dust particles, astrophysicists say we can learn about our cosmic roots. Cosmic particles are all around us, however, it is near impossible to tell it apart from all the earthly particles in the air. Such things as pollen, pollution, soil, human skin, etc. Not only is space dust hard to see it’s even harder to catch, they are the size of 100 micrometers (Or the width of a hair). To collect space dust scientist have turned to Antarctica. Where there are little to known of earth’s floating particles. The Amundsen-Scott South Pole stat ion draws its drinking water from a well in a cavity of the never-ending ice. As the water is pumped up through a small hole on the surface, the water is heated and shot back down to melt more ice. As the ice melts, it frees the space particles that were in the snowflakes. There was a lot of build up of particles on the well floor. Studying these particles was as easy as throwing a bucket down a hole. Another way dust particles are collected is to attach sticky film to a high altitude aircraft. Once the Astrophysicist have captured the dust, they can determine how fast it entered the earth’s atmosphere thus telling us if it came from a comet, asteroids, or virginal stardust. The Astrophysicist determines the speed of the dust by putting the dust particle in an oven. They rise the temperature until the minerals in the dust particle start to evaporate. If the minerals evaporate at 901 degrees but not at 900 we know that the dust particle was heated to a ma...

Ramifications of the Reconstruction Period essays

Ramifications of the Reconstruction Period essays The reconstruction of the south was the period during and after the Civil War where several different groups in the government tried to solve the economic, political, and social problems that arose as a result of the Civil War. It was a time of disorder and chaos. Southern whites rejected all forms of equality and blacks wanted nothing but full freedom and land of their own. This led to frequent and inevitable riots. Reconstruction lasted from 1865 to 1877 and was one of the most controversial periods in the nation's history. People still debate its successes and failures. Many people blames Reconstruction failure on black politics, calling it "Negro government." Even some newspapers that were in favor of Reconstruction blamed the black legislatures. Foner wrote, "Ironically, even as racism waned as an explicit component of the Northern Democratic appeal, it gained a hold on respectable Republican opinion, as a convenient explanation for Reconstruction's failure." Black politicians could have been the demise of Reconstruction. Another cause of Reconstruction could have been the Court's intervention. Foner stated, "Previously, the court had proved reluctant to intervene in Reconstruction controversies. The Compromise of 1877 between the Republicans and Democrats, occurring in January of that year, was the solution to the contested Presidential election of 1876 and furthermore brought an end to the period of Reconstruction following the Civil War. The banks could have also caused the failure of Reconstruction to speed up. The Freedman's Savings Bank went under with no money to pay its depositors. The bank held thousands of black's (Freedman) money. "In June 1874, with only $31,000 on hand to cover obligations to its 61,000 depositors, the Freedman's Savings Bank suspended operations." One of the main reasons for the failure of Reconstruction was the dropped prices of crops. Many farmers and sharecroppers could not live off what th...