Franz Peter Schubert Essay Example | Topics and Well Written Essays - 1000 words

Franz Peter Schubert - Essay Example He worked at his father’s office until the spring of 1986 and pursued his application for a higher position. From that year onwards, he failed to get a regular job. He became a freelance musician, earning money only where and when opportunity allowed him. The popularity of his music won him a lot of friends who supported him when he was financially incapable. He was not really concerned with generating income to feed and clothe himself. All he wanted to do was to focus on his musical career by writing compositions (Hurd 294).Schubert’s works have gained wide popularity and they began to appear in print in 1821. At first, his musical compositions were paid for by private subscribers. However, his musical genius was highly regarded as he was later paid by regular publishers. Entering a new a more assured phase, he wrote more piano sonatas and was elected to the Vienna Gesellschaft der Musikfreunde (Franz Schubert).Schubert became famous in Viennese musical circles. Schube rt-Evenings or Schubertiads were frequently conducted where he played his latest works to his friends who were artists, poets, and wealthy bourgeoisie. His circle of friends includes Josef von Spaun, Johann Mayrhofer, and Franz von Schober. This elite circle gave him access to influential contacts like the Sonnleithners and the baritone J.M. Volg (Franz Schubert). The death of Schubert in 1828 was due to typhus. After a few days’ illness, he died and was buried in a grave near Beethoven’s (Hurd 294).... However, his musical genius was highly regarded as he was later paid by regular publishers. Entering a new a more assured phase, he wrote more piano sonatas and was elected to the Vienna Gesellschaft der Musikfreunde (Franz Schubert). Schubert became famous in Viennese musical circles. Schubert-Evenings or Schubertiads were frequently conducted where he played his latest works to his friends who were artists, poets, and wealthy bourgeoisie. His circle of friends includes Josef von Spaun, Johann Mayrhofer and Franz von Schober. This elite circle gave him access to influential contacts like the Sonnleithners and the baritone J.M. Volg (Franz Schubert). The death of Schubert in 1828 was due to typhus. After a few days' illness, he died and was buried in a grave near Beethoven's (Hurd 294). His Music: Schubert is known as one o the most prolific composers of melodies in his period, with his capacity to write almost eight compositions in a day. Schubert wrote over 600 songs. The two most famous are Die Schune Mullerin and Die Winterreise. His most well known chamber music includes Piano Quintet in A major-The Trout, Piano Quartet in D minor-'The Death of the Maiden,' Octet in F major and String Quintet in C major. He was able to writ 15 string quartets, 14 piano sonatas, and sets of dances and variations for piano, as well as the remarkable 'Wanderer Fantasy.' Schubert has composed 10 symphonies, the most important ones are No. 4 in C minor-'The Tragic,' No. 5 in B flat major, No. 6 in C major, No. 8 in B minor--'The Unfinished,' and No. 9 in C major-'The Great C major." His choral music includes Mass in A flat, Mass in E flat, and many short choral songs with piano accompaniment. Schubert also

International Hotel DEvelopment Essay Example | Topics and Well Written Essays - 3000 words

International Hotel DEvelopment - Essay Example Hotels are one of the most profitable enterprises of this industry, particularly luxury hotels. Unlike upscale and upper upscale hotels, although luxury hotels offer many of the same features and give relatively the same living experience, it is their exclusive nature that sets them apart from other such hotels (Barsky, 2001). With only a few hotels per country classified in the highest tier of luxury hotels, they make the base of the hospitality industry’s strength. The Marriott Hotel in London is one such hotel. To understand what terms are these hotels classified into, the very specific categories that the hospitality industry puts them in it is important that one thoroughly analyzes and understands the hotels that make up each level and standard. This means to gauge the full effect and scope of a particular hotel, in this case the Marriott Hotel in London. This can be done best through either the SWOT analysis, defined by Albert Humphrey, which focuses on the strengths, we aknesses, opportunities and threats of an environment or the PESTLE analysis, which means analyzing the political, economic, social, technological, legal and environmental factors of a hotel. All will be used in reference to the internal or external environment of the hotel, respectively. Hotels are generally judged and analyzed based on two factors – that is, their internal and external environment (Jones and Lockwood, 2004). The internal environment of a hotel refers to all factors and features that remain exclusively confined to that establishment itself. For example, all factors such as the business revenue of the hotel, the physical features of the hotel, the staff and other positions of the hotel, all contribute towards the internal environment of the hotel. As an extension of this, it can be said that any factors contributing towards and influencing the internal environment and state of a hotel can also be considered part of the environment itself (Huo, 1995). The fact ors that decide what an internal environment is based upon are factors such as what a company wishes to provide its customers with, and how its strengths can cater to those requirements. Other factors can be the means with which to provide their services and the services it wishes to furnish those requirements. In summary, the strengths, aims, resources and requirements of an industry all contribute towards constructing its internal environment and the manifestation of these components is what provides the physical representation of this internal environment (Raghubalan and Balan, 2007). On the other hand, the external environment of a hotel refers to all factors and influences that come from outside the enterprise itself. This means, all factors other than the business’s own desires, aims, means etc are considered external environmental factors. The external environment factor can influence the internal environment of a hotel or enterprise, but it is not only confined to suc h an enterprise. It can have effects of its own independence, other than in relation to being an influencing factor. Government policies, economic conditions, technological advances are all factors that comprise the external environment, but the biggest most important factor of the external envi

Transducers used in the Cardiac Ultrasound Machine.

Transducers used in the Cardiac Ultrasound Machine. Transducers used in the Cardiac Ultrasound Machine. Abstract: Ultrasound imaging depends on the ability of piezoelectric crystals to generate sound when excited with alternating current and the reverse effect of charge accumulation or current flow when such crystals are subjected to pressure from sound waves. The first known ultrasound imaging machine was designed by K. T. Dussik in Australia in 1937. However, despite its widespread acceptance today, medical ultrasound did not develop as rapidly as X-ray imaging. Despite the relatively slow start, medical ultrasound imaging is very widely accepted today because there is no ionising radiation involved and hence the procedure is relatively safe. Ultrasound equipment is also cheaper as compared to X-ray imaging, magnetic resonance imaging, MRI and other techniques associated with nuclear medicine. The procedure involves minimal patient discomfort and is very useful for examining the soft tissues or the developing foetus. A dramatic increase in the number of older patients with chronic he art and valve disease has resulted in a prolific demand for the ultrasound cardiac imaging machines which can satisfy the requirements associated with fast and cost effective measurement of cardiac anatomy or function. One of the critical elements in the medical ultrasound imaging system is the ultrasound transducer without which signal processing and visualisation of the soft tissue images is impossible. Although many naturally occurring substances such as quartz exhibit the piezoelectric effect, lead zirconate titanate (PZT) ceramic ferroelectric materials have for many years been used for biomedical applications because of their superior characteristics for soft tissue imaging.   Polyvinylidene difluoride (PVDF), transducer material has demonstrated advantages as a high frequency receiver. Single or multilayer transducers made of these elements can be used for ultrasound imaging as single transducers operating in A-mode or a two or three dimensional transducer array for B-mode, C-mode or M-mode ultrasound imaging. This brief essay takes a look at transducers for medical ultrasound. The principle of operation of a cardiac ultrasound imaging device is based on the information that is provided by the varying delay times of echoes that are reflected from various depths of the human body tissue as a result of the ultrasound pulses that are generated by an ultrasound transducer being incident on the body tissue. Delay times of echoes from different depths are different and ultrasound is reflected from the interface of different types of tissues. A Doppler shift in frequency is also generated as a result of moving objects and the attenuation of ultrasound waves depends on the type of tissue that the ultrasound wave is travelling through. The ultrasound transducer which is responsible for the generation and detection of reflected ultrasound is, therefore, an essential component of the ultrasound imaging device. Ultrasound transducers work on the basis of the piezoelectric effect in which an alternating voltage applied to piezoelectric crystal material causes the crysta ls to become electrically polarised as a result of the applied electric field and hence vibrate with the alternating voltage to produce sound. Such crystals also become electrically polarised when stress is applied to them and hence any sound waves which are incident on them result in charge accumulation on the crystal surface and hence the generation of an alternating voltage. Thus, an ultrasound transducer consists of a suitable piezoelectric material sandwiched between electrodes that are used to provide a fluctuating electric field when the transducer is required to generate ultrasound. When the transducer is required to detect ultrasound, the electrodes may be used to detect any fluctuating voltages produced as a result of the polarisation of the crystals of the piezoelectric material in response to incident sound which generates fluctuating mechanical stresses on the material. Piezoelectric materials include quartz, ferroelectric crystals such as tourmaline and Rochelle salt a s well as the group of materials known as the piezoelectric ceramics, which include lead titanate (PbTiO3) and lead zirconate (PbZrO3). These materials are also known as piezoelectric ceramics which are used in ultrasound transducers for biomedical applications.Polyvinylidene difluoride (PVDF) is another transducer material which has demonstrated advantages as a high frequency receiver. Piezoelectric ceramics are sold with the brand name PXE by Philips Company and are solid solutions of lead titanate (PbTiO3), and lead zirconate (PbZrO3) which have been modified by additives which are a group of piezoelectric ceramics known as PZT. PXE materials are hard, chemically inert and unaffected by a humid environment. The crystals in a ferroelectric material of which PXE is made up of align themselves randomly in a number of directions. With such a random orientation of crystals, the material will exhibit no piezoelectric effect. In order to have a piezoelectric material which is capable of being used for ultrasound transducers, the material has to be subjected to a strong electric field at high temperatures. This has the effect of permanently locking the crystals in the direction of the applied electric field and making the crystal piezoelectric in the direction of the electric field. Hence, a piezoelectric ceramic material may be converted into a piezoelectric material in any given direction by applying a strong electric field to the material in the given direction at an elevated temperature. This treatment, which is known as poling, is the final stage in the manufacture of a PXE piezoelectric. Metal electrodes perpendicular to the poling axis are deposited on the material so that an alternating electric field may be applied to generate ultrasound or ultrasound vibrations may be sensed by sensing the electric field across the piezoelectric material. The voltage across a piezoelectric ceramic PXE material is usually directly proportional to the applied stress. The construction of a simple, single element piezoelectric transducer is as shown below. The Construction of a Single Element Piezoelectric Transducer Ultrasound imaging in the A-mode directs a narrow beam of ultrasound into the tissue being scanned and the echo which may be displayed on a CRT screen provides a measure of the distance between reflecting surfaces in the body. In the B-scan mode, the echo signal is brightness modulated which makes it possible for information related to tissue depth to be displayed on the screen in a visually effective manner. An ultrasound transducer array operating in B-mode permits a picture of the tissues within a patient’s body to be displayed on a CRT device. M-mode ultrasound imaging presents tissue movement by scanning an A or B – line on a monitor as a function of time and movements in this line indicate movements in the tissues within the body. In C-mode ultrasound imaging a second transducer is used to detect echoes sent out by the first transducer, presenting a 2-D map of the ultrasound attenuation within tissues. Having discussed the principles of operation of a piezoelectric medical ultrasound transducer, it is now appropriate to consider the practical problems associated with the construction of such transducers. This is done below. The Design of Ultrasound Transducers A transducer which is constructed out of piezoelectric material will have a natural frequency of resonance and it is appropriate that the transducer should be excited with alternating electric field which matches the natural resonant frequency of oscillation of the material. The ultrasound frequencies that are used in medical imaging applications range from 1 MHz to 15 MHz and echocardiography is usually performed at frequencies of 2.5 MHz. Hence, transducers which are used for ultrasound imaging have to be tuned for different frequencies. For a transducer material in which ultrasound waves travel at the speed c, with a resonant frequency f, the thickness of the material is related by the formula f=c/2d. Hence, it is possible to tune various transducers constructed of the same material to different frequencies by adjusting the thickness of the material. The ultrasound transducer can be excited by a continuous wave, a pulsed wave, or a single voltage pulse depending on the requirement s for observing a continuous image, echo ranging or other tissue measurements. The rear face of the piezoelectric crystal material is usually supported by a backing material which is tungsten loaded araldite, so that the vibrations in the piezoelectric material are rapidly damped after the initial excitation. It is important to couple the piezoelectric transducer to the body of a patient so that the incident ultrasound energy can be effectively transmitted into the body tissue that is being scanned. In order to do this, matching layers of suitable acoustic material are used along with a gel which makes it possible for the ultrasound waves to penetrate the tissue more efficiently. As far as possible, the characteristic acoustic impedance of the tissue being scanned is matched with the acoustic impedance of the transducer. The characteristic acoustic impedance of the tissue is defined as: In the formula, c is the speed of ultrasound in human tissue which is about 1540 m/sec with a variation of +/- 6% and   is the tissue density. K is the bulk elastic modulus of the tissue being scanned. The acoustic parameters of an ultrasound transducer include its nominal frequency, the peak frequency which is the highest frequency response measured from the frequency spectrum, the bandwidth of the transducer which is the difference between the highest and the lowest – 6 dB level in the frequency spectrum, the pulse width response time of the transducer, which is the time duration of the time domain envelope which is 20 dB above the rising and decaying cycles of a transducer response, the loop sensitivity for a medium on which a test is performed which is characterised by: Here, Vo is the excitation pulse voltage in volts, while Vx is the received signal voltage from the transducer.   The signal to noise ratio for a biomedical ultrasound transducer is also an important parameter for an ultrasound transducer and this is defined as: In the above expression, Vx is the received signal voltage from the transducer in volts in response to a specified tone burst or pulse and Vn is the noise floor in volts. The signal to noise ratio for an ultrasound transducer is a measure of the noise associated with the transducer, measuring instrument or cables and this is a good measure of how sensitive a transducer is. In addition to the previously mentioned parameters, geometrical parameters for a transducer describe how the acoustic pressure generated by a transducer varies across the axial and cross-sectional fields of a transducer. These variations are illustrated below: Axial Beam Profile for an Ultrasound Transducer Cross – Sectional Beam Profile for an Ultrasound Transducer he detailed construction of an ultrasound transducer for medical applications involving the shaping of the piezoelectric material, matching layers, housing and backing materials etc is presently conducted using computational techniques such as Finite Element Modelling of ultrasound transducers through the use of software packages such as Ultrasim and other commercially available software. In the overall design, efforts have to be made to ensure that the overall design will be optimised so as to deliver a sufficiently high power of ultrasound into the tissue being imaged and as far as possible there is best possible sound impedance matching between the transducer and the scanned tissue. Design of the backing material in an ultrasound transducer is important because this design determines the ring down time of the transducer, which is critical for low noise and optimal axial resolution of the transducer. Trends in Transducer Design for Echocardiography Only the simplest equipment for echocardiography will use a single ultrasound transducer and there is a trend towards design of echocardiography equipment which uses two or even three dimensional arrays of ultrasound transducers to provide superior quality 2 –D or 3-D computer generated pictures of the organ being imaged.   Even the relatively simpler equipment being used these days has two or more ultrasound transducers fitted into the transducer probe. The array of transducers are capable of generating a shaped beam of ultrasound which can be appropriately focused using electronic digital signal processing techniques to provide better images and resolution. Although the relatively simple medical ultrasound scanners cost about  £1000 per piece, reasonably decent transducer assemblies for a decent Philips or Toshiba ultrasound machines can cost  £1500 for the transducer alone. Transducer arrays for two or three dimensional ultrasound imaging equipment can be much more ex pensive because of the large number of transducers that are employed in such imaging equipment.   For better quality ultrasonic imaging to be possible, there is a requirement for enhanced bandwidth transducers, higher frequency transducer arrays and sophisticated digital signal processing circuits. There is also a trend towards transducer miniaturisation which will make intracavitary, intraurethral, or intravascular ultrasound (IVUS) investigation possible. The current imaging frequency range of 1 MHz to 15 MHz is expected to be increased to 20 MHz to 100 MHz and at these frequencies, microsonography devices using miniature ultrasound transducers with higher sensitivities are expected to provide much better and higher resolution images using catheter based transducers which are less then 2mm in diameter and are capable of being placed in veins.   New ultrasound transducer materials are likely to provide transducers which are far more sensitive then those available presently and consume lower power. These transducers can be operated from battery powered portable equipment and th ere are indications in literature that with the availability of such devices, it is likely that the stethoscope will be replaced by miniature ultrasound equipment. New trends in ultrasound transducer construction are also moving towards composite transducer construction in which a composite of two piezoelectric materials is used to design the transducer. Ultrasound transducers are fairly rugged and the piezoelectric material does not loose its properties unless exposed to high temperatures approaching the Curie temperature for the material are reached or there are strong alternating or direct electrical fields opposing the direction of poling for the material. Mechanical stresses imposed on the piezoelectric materials should not exceed the specified limits and although the specified limits vary for different types of materials, mechanical stress in excess of 2.5 MPa may be considered as likely to cause permanent damage. Ultrasound transducers are capable of being designed to operate in liquid mediums and the piezoelectric material does not react with water or gel.   Conclusion Materials with piezoelectric properties such as lead titanate (PbTiO3) and lead zirconate (PbZrO3) lend themselves to being treated by poling to generate as well as detect ultrasound waves when subjected to alternating electric fields or mechanical stresses. Ultrasound transducers can be made out of these materials and these transducers can be designed for specified resonance frequencies for use in medical imaging. The detailed design of such transducers is an exciting and involving undertaking which is capable of being assisted by finite element simulations. Advances in transducer design involving the use of new materials, miniaturisation and the use of arrays of transducers promises to revolutionise medical imaging in the future by providing high resolution 3-D ultrasound images and the field is full of promise for device designers as well as computer engineers of the future. References/ Bibliography Web Sources   Abboud, Najib N et al. â€Å"Finite Element Modelling for Ultrasonic Transducers†. Weidlinger Associates Inc. SPIE Int. Symp. Medical Imaging 1998, San Diego, Feb 21-27, 1998. August 4, 2005. http://www.wai.com/AppliedScience/Software/Pzflex/Papers/pzflex-spie_mi98.pdf Binder, T. â€Å"Three-Dimensional Echocardiography Principles and Promises†. Journal of Clinical and Basic Cardiology 2002; 5 (Issue 2), 149-152. August 4, 2005. http://www.kup.at/kup/pdf/1137.pdf Brandt, Einar. â€Å"Segmentation Techniques for Echocardiographic Image Sequences†. University of Linkopings. 1998. August 4, 2005. http://www.imv.liu.se/klinfys/einar/publications/pdf_open/Ex1934.pdf Bridal, Lori S et al. â€Å"Milestones on the Road to Higher Resolution, Quantitative, and Functional Ultrasonic Imaging†. PROCEEDINGS OF THE IEEE, VOL. 91, NO. 10, OCTOBER 2003. August 6, 2005. http://dei-s1.dei.uminho.pt/outraslic/lebiom/ultra/ultrasonic01232192.pdf Diederichs, Rolf. â€Å"Ultrasound Transducer Library†. Diederichs, Rolf. March, 1998. August 4, 2005. http://www.ndt.net/wshop/wshop_tr/trans_li.htm Eberhard, Brunner. â€Å"Ultrasound System Considerations and their Impact on Front-End Components,† Analog Devices, Inc., 2002. August 4, 2005. http://www.analog.com/library/analogDialogue/archives/36-03/ultrasound/UltrasoundFrontend.pdf Erikson, Kenneth R et al. â€Å"Ultrasound in Medicine – A Review†. IEEE TRANSACTIONS ON SONICS AND ULTRASONICS, VOL. SU-21, NO. 3, JULY 1971. August 4, 2005. http://www.ieee-uffc.org/ultrasonics/teaching/t7430144.pdf Fink, Mathias. â€Å"Time Reversed Acoustics†. Scientific American Inc, 1999. August 4, 2005. http://www4.ncsu.edu/~fouque/fink.pdf G. Fleury, R. Berriet, O. Le Baron, B. Huguenin. â€Å"New piezocomposite transducers for therapeutic ultrasound†. 2nd International Symposium on Therapeutic Ultrasound Seattle 31/07 02/08/02. August 4, 2005. http://www.imasonic.com/Papers/ISTU2Ima.pdf Genadiy V. Leonov,, Vladimir N. Khmelev, Roman V. Barsukov, Sergey N. Tsyganok, Alexey N. Slivin, Andrey V. Shalunov. â€Å"Advancement of Ultrasonic Technologies Efficiency, Development of Ultrasonic Devices for the Manufactures, Medical Institutions and the Agriculture Requirements†. Biysk Technological Institute. 2004. August 4, 2005. http://www.bti.secna.ru/institute_/laboratory/us/downloads/vestnic_e.pdf Goel, Malti. â€Å"Electret sensors, filters and MEMS devices: New challenges in materials research†. Current Science. Volume 85. No. 4. August 25, 2004. August 4, 2005. http://www.ias.ac.in/currsci/aug252003/443.pdf Hazas, Mike and Andy Ward. â€Å"A Novel Broadband Ultrasonic Location System†. University of Cambridge, United Kingdom. 2002. August 4, 2005. http://www.comp.lancs.ac.uk/~hazas/Hazas02_ANovelBULS.pdf Holm, Sverre. â€Å"Ultrasim – A Toolbox for Ultrasound Field Simulation†. University of Oslo. 2000. August 6, 2005. http://heim.ifi.uio.no/~sverre/papers/01_Matlab.pdf Krochak, Paul and Stefan Story. â€Å"Acoustic Densification of Multiphase Stream†. University of British Columbia. June 19, 2005. August 4, 2005. http://www.math.ubc.ca/~FluidLab/people/sstorey/Densificatio_Final_Report.pdf Ladabaum, Igal et al. â€Å"Surface Micro machined Capacitive Ultrasonic Transducer†. ieee transactions on ultrasonics, ferroelectrics, and frequency control, vol. 45, no. 3, may 1998. August 4, 2005. http://piezo.stanford.edu/library/papers/IL1998.pdf Lewin, Peter A. â€Å"Diagnostic Ultrasound: A Glimpse into the Next Decade†. Drexel University. 2004. August 4, 2005. http://www.wma.net/e/publications/pdf/2000/lewin.pdf M. Greenstein, P. Lum, H. Yoshida, M.S. Seyed-Bolorforosh. â€Å"A 2.5 MHz 2D Array with Z-Axis Electrically Conductive Backing†. 2004. August 4, 2005. http://www.hpl.hp.com/techreports/96/HPL-96-89.pdf Measurement Specialties Inc. â€Å"Piezo Film Sensors – Technical Manual†. Measurement Specialties Inc. April 2, 1999. August 4, 2005. http://www.media.mit.edu/resenv/classes/MAS836/Readings/MSI-techman.pdf Michael Greenstein. â€Å"Multilayer Piezoelectric Transducers for Medical Ultrasound Transducers†. Hewlett Packard Laboratories. 2000. August 4, 2005. http://www.hpl.hp.com/techreports/95/HPL-95-79.ps Morgan Electro Ceramics. â€Å"Introduction: Piezoelectric Ceramics†. Morgan Electro Ceramics. May 16, 2001. August 4, 2005. http://www.morganelectroceramics.nl/pdfs/tech.pdf North Dakota State University. â€Å"Imaging Systems†. North Dakota State University. 2004. August 4, 2005. http://venus.ece.ndsu.nodak.edu/~schroeder/Imaging%20Systems.doc Nottingham University. â€Å"Medical Ultrasound†. Nottingham University. 2004. August 4, 2005. http://www.nottingham.ac.uk/physics/ugrad/courses/mod_home/f31ab1/notes/us.doc Petersen R.B. and J. Hutchins. â€Å"The iE33 intelligent echocardiography system†. Philips Ultrasound Medical Systems. 2004. August 4, 2005. http://www.medical.philips.com/main/news/assets/docs/medicamundi/mm_vol48_no3/11_Peterson.pdf Picture IQ.com. â€Å"Ultrasound Equipment†. Picture IQ.com. 2005. August 6, 2005. http://www.pictureiq.com/piq/ph30-63999-Ultrasound.mspx Powis, Raymond. L and G. Wayne Moore. â€Å"The Silent Revolution: Catching up with the Contemporary Composite Transducer†. JDMS 20:395–405 November/December 2004. August 4, 2005. http://www.medphysics.wisc.edu/mp666/powis_moore_contemp_trans.pdf Rainer Stotzka, Helmut Widmann, Tim Muller, Klaus Schlote Holubek, Hartmut Gemmeke, Nicole Ruiter, Georg Gobel. â€Å"Prototype of a new 3D ultrasound computer tomography system: transducer design and data recording†. Forschungszentrum Karlsruhe. 2004. August 4, 2005. http://www.stotzka.de/Publications/stotzka2004.1.pdf RATSIMANDRESY, Leong, P.Mauchamp, D. Dinet, N. Felix, R. Dufait. â€Å"A 3 MHz, Two Dimensional Array Based on Piezocomposite for Medical Imaging†. IEEE Ultrasonics Symposium Proceedings. 2002. August 4, 2005. http://www.vermon.com/Biblio_Vermon/IEEE_3MHz%202D%20Array.pdf Ritter, Timothy et al. â€Å"Single Crystal PZN/PT-Polymer Composites for Ultrasound Transducer Applications†. IEEE transactions on ultrasonics, ferroelectrics, and frequency control, vol. 47, no. 4, July 2000. August 4, 2005. http://www.ieee-uffc.org/archive/public/opapers/jul792.pdf Ronald E McKeighen. â€Å"Design Guidelines for Medical Ultrasonic Arrays†. Acoustic Imaging Transducers Inc. 2000. August 4, 2005. http://www.wai.com/AppliedScience/Software/Pzflex/Papers-other/spie-man.pdf Saleh K. Y. and N.B. Smith. â€Å"Two-dimensional ultrasound phased array design for tissue ablation for treatment of benign prostatic hyperplasia†. Pennsylvania State University. May, 2003. August 4, 2005. http://www.bioe.psu.edu/ultrasound/Research/Saleh%20Smith%20IJH04.pdf Schmidt, M. â€Å"Ultrasonic Signal Processing Chip For Intraluminal Catheter Based Systems†. Fraunhofer Institute of Microelectronic Circuits and Systems. 2004. August 4, 2005. http://www.imec.be/esscirc/papers-96/143.pdf Shindler, Daniel M. â€Å"Hand-held Ultrasound and the Stethoscope†. Robert Wood Johnson Medical School. 2004. August 4, 2005. http://www.bbriefings.com/pdf/950/shindler.pdf Ultran. â€Å"Medical Ultrasonic Transducers†. Ultran. 2004. August 4, 2005. http://www.ultrangroup.com/pdfs/ultran_trans_cat.pdf University of Central London. â€Å"An Overview of Existing Medical Imaging Techniques†. University of Central London. 2004. August 4, 2005. http://www.medphys.ucl.ac.uk/research/borl/homepages/florian/thesis/pdf_files/p35_44.pdf University of Lancaster. â€Å"Medical Ultrasound Imaging†. University of Lancaster. 2004. August 4, 2005. http://www.lancs.ac.uk/depts/physics/teaching/py336/Ultrasound.doc Wang, Haifeng, Tim Ritter, Wenwu Cao, and K. Kirk Shung. â€Å"Passive Materials for High Frequency Ultrasound Transducers†. The Society of Photo optical Instrumentation Engineers, SPIE. 1999. August 6, 2005. http://www.bioe.psu.edu/labs/NIH/pass_mat.pdf Weigang, Beate, G. Wayne Moore, M.A., James Gessert, William H. Phillips, Mark Schafer. â€Å"The Methods and Effects of Transducer Degradation on Image Quality and the Clinical Efficacy of Diagnostic Sonography†. Sonic Technology Laboratories. 2004. August 4, 2005. http://www.4sonora.com/products/Transducer%20Degradation%20on%20Image.pdf Wells, P.N.T. â€Å"Ultrasonic Imaging of the Human Body†. Bristol General Hospital. 1999. August 4, 2005. http://www.hrcc.on.ca/Research/bios/people/pattersonfiles/Wells%20paper.pdf Whitehouse, Kamin. Fred Jiang, Chris Karlof, Alec Woo, David Culler. â€Å"Sensor Field Localisation: A Deployment and Emperical Analysis†. University of California, Berkley. April 9, 2004. August 4, 2005. http://www.cs.berkeley.edu/~kamin/pubs/whitehouse04ultrasoundUCBtechReport.pdf References Related to Ultrasound Transducers from British Libraries . Medical Imaging 1999: Ultrasonic Transducer Engineering: 24-25 February 1999, San Diego, California. Bellingham, Washington: SPIE, 1999. . Medical Ultrasound: Mirror Transducer Systems for High Resolution Imaging. 1984. American Association of Physicists in Medicine. Medical Physics of CT and Ultrasound: Tissue Imaging and Characterization: Summer School: Papers and Discussions. American Institute of Ultrasound in Medicine. Ultrasound Practice Committee Report for Cleaning and Preparing Endocavitary Ultrasound Transducers Between Patients. Laurel, Md.: American Institute of Ultrasound in Medicine, 1995. American Society of Ultrasound Technical Specialists and Society of Diagnostic Medical Sonographers. Medical Ultrasound. New York: Wiley. Barnett, S. B., G. Kossoff, and World Federation for Ultrasound in Medicine and Biology. Safety and Standardisation in Medical Ultrasound: Issues and Recommendations Regarding Thermal Mechanisms for Biological Effects of Ultrasound: Symposium: Papers. Pergamon Press, 1992. British Medical Ultrasound Society. BMUS Bulletin. London: British Medical Ultrasound Society, 2003. Davies, Christopher Mark. The Construction and Design Characteristics of Bimorph Shear Wave Transducers. 1993. Fleming, David G., et al. Indwelling and Implantable Pressure Transducers: Based on Workshop Held in Cleveland, Ohio on December 4 and 5, 1975, Sponsored by the Biotechnology Resources Branch (RR-00857) and the National Institute of General Medical Sciences (GM-14267) of the National Institutes of Health. Cleveland: CRC Press, 1976. Great Britain. Medical Devices Agency. A Comparative Technical Evaluation of Eleven Ultrasound Scanners for Examination of the Breast. Medical Devices Agency, 2001. Kuhn, A., P. A. Payne, and Dias. Design and Construction of Ultrasound Equipment for Characterization of Elastic Mechanic Properties of Dental Restorative Materials. Manchester: UMIST, 1991. Luukkala, Mauri. Second Harmonic Generation of Ultrasound in Quartz Transducers. Turku, 1967. Mok, W. H., M. S. Beck, and Dias. Flow Imaging Using Pulsed Ultrasound Transducers. Manchester: UMIST, 1986. Nakano, Hitoo, et al. XX International Congress The Fetus As a Patient and 6th Ian Donald Inter-University of Medical Ultrasound. 2004. Nicoll, J. J. and University of Edinburgh. Medical Ultrasound: Mirror Transducer Systems for High Resolution Imaging. University of Edinburgh, 1984. Preston, R. C., et al. The Performance of the NPL Ultrasound Beam Calibrator: Part 1 Physiotherapy Transducers. Teddington: National Physical Laboratory, 1986. Ruttenberg, Robert and Simon Peck. Transducer Development for Medical Dynamic Measurements. 2000. Shung, K. Kirk and Society of Photo-optical Instrumentation Engineers. Medical Imaging 1998: Ultrasonic Transducer Engineering: 25-26 February 1998, San Diego, California. Bellingham, Washington: SPIE, 1998. Society of Diagnostic Medical Sonographers. JDMS: Journal of Diagnostic Medical Sonography. Philadelphia: Lippincott for the Society of Diagnostic Medical Sonographers. Society of Ultrasound in Medicine of the Republic of China. Journal of Medical Ultrasound. Taipei. Turnbull, Daniel H. and University of Toronto Department of Medical Biophysics. Two-Dimensional Transducer Arrays fo

Pro Death Penalty Essay -- Capital Punishment essays research papers

Capital punishment and the practice of the death penalty is an issue that is passionately debated in the United States. Opponents of the death penalty claim that capital punishment is unnecessary since a life sentence accomplishes the same objective. What death penalty opponents neglect to tell you is that convicted murders and child rapists escape from prison every year(List of prison escapes, 2015). As I write this essay, police are searching for two convicted murders who escaped from the Clinton Correctional Facility in Dannemora, New York on June 6th, 2015. The ONLY punishment from which one cannot escape is the death penalty. Opponents of the death penalty believe capital punishment is unnecessary and inappropriate in our modern society. In their minds, such an act by the government serves no positive social purpose and only denigrates life (Death Penalty Focus, 2015). On the other hand, those in favor of capital punishment, including the US Supreme Court, see the death penalty as the proper punishment for certain criminals who have committed specific crimes. Supporters also argue that the death penalty is a necessary deterrent to saving innocent lives (Pro-Death Penalty, 2014). Based on my research of this issue I tend to agree with the death penalty advocates and believe that execution is the appropriate sentence and punishment for capital offenses. There are six main rationales for abolishing the practice of capital punishment that are commonly heard. One reason is that capital punishment does not deter crime. Anti-death penalty advocates contend that scientific studies consistently fail to demonstrate that executions discourage people from committing crime (Death Penalty Focus, 2015). Another reason for stopping the death penalty is because it can and has been inflicted on innocent people. In addition, abolitionists suggest that the US is unable to prevent such occurrences (Death Penalty Focus, 2015). A third rationale is that the death penalty discriminates against certain ethnic and racial groups. According to Justice Department figures, nearly 80 percent of inmates on death row are Black, Hispanic or from another minority group (Eddlem, 2002). Yet another reason for abolishing capital punishment is that the death penalty is often applied at random. â€Å"Politics, quality of legal counsel and the jurisdiction where a crime is committed are more... ... it achieves justice. In my opinion, people who commit heinous crimes against humanity should be executed. Regardless of cost or how long it takes I believe that putting these people to death is the correct sentence, not only because I feel that they deserve to die but because the death penalty is a deterrent and society is better off without these criminals. Therefore I agree with supporters of capital punishment and that the death penalty should remain in existence. My research further solidified my position because I felt that the arguments in favor of capital punishment clearly debunked many of the reasons for abolishment by the anti-death penalty movement. References Death Penalty Focus (2015). Facts. Web. 8 June 2015. http://www.deathpenalty.org/index.php?pid=facts Eddlem, T. R. (2004). Ten Anti-Death Penalty Fallacies.The New American. 2002. Web. 10 June 2015. http://www.thenewamerican.com/tna/2002/06-03-2002/vo18no11_fallacies.htm Pro-Death Penalty (2014). Death Penalty Paper. Web. 8 June 2015. http://www.prodeathpenalty.com/DP.html "List of prison escapes" Wikipedia 2015. Web. 8 June 2015. https://en.wikipedia.org/wiki/List_of_prison_escapes

Hampton Machine Tool Company Essay

About The Company Hampton Machine Tool was established in 1915 and has been manufacturing machine tools since its foundation. Hampton company’s customer base is made up primarily of aircraft manufacturers and automobile manufactures in the St. Louis area. It experienced record production and profitability during the years. Sales and profitability declined in the mid-1970s with the withdrawal from Vietnam War and the oil embargo. However, the company had stabilized the massive of sales by the late 1970s. The reasons of Hampton’s recovery were the increasing number of military aircraft sales in both export and domestic markets, the automobile industry rising and an improvement in the economy. Summary of The Problem Hampton Machine Tool Company have problems with the repayment of its $1million loan due date of September 1979. The loan was used for the stock repurchase. Thanks to the president of Hampton Company- , Mr.Cowin’s good reputation and the credibility in the business community and submission of projected sales and forecasted financial statements St.Louis National Bank gave the loan to the company. There were several factors caused the failure of forecast sales including firstly, the detention of delivery by the major component supplier on time, secondly, the purchase of $420,000 worth of components over normal level of inventory, thirdly, problems of machines occured during the production period. On the other hand, the company plans to pay a dividend of $150,000 in 1979. Therefore, Hampton needs an additional loan of $350,000 till October to be paid on December 1979 along with the initial loan Analysis The bank should make decision by the end of the October due to the maturity date of the initial loan. To assess the borrower’s ability for the repayment Pro-forma Financial Statements, Profitability ratios, Liquidity and leverage ratios, and projected cash budget should be assessed. Projected Cash Budgets and Proforma Financial Statements yield negative results about the principal payment of the loan for December 1979. The  forecasts of this analysis are based on projected sales, one month extension of the loan and dividend payment, and starting to repay the loan early. Projected Sales If sales projections and accounts receivables are not met, this situation will be worse than the present one financially. But as we can see in the projected cash budget, ending cash balance in December is negative so that Hampton will be unable to repay the loan on that time. On the other hand repayment in January will be possible with more accurate planning. Liquidity Ratios The reason of the paradox of increasing current ratio and net working capital but decreasing quick ratio is the increasing level of inventories Activity Ratios  The average age of inventory improved as a result of an increase in inventories. The company has a stock of row materials, and there are additional inventories waiting for the production process. The receviables management seemed to improve but collection in July and August needs a concern and a further study should be undertaken. Profitability Ratios Although there is unstable trend, Hampton Company’s profit ratios seems as its best visible to the company’s increase on its Net Profit Margin both in history and projection. Dividend Payment The company repurchased a substantial fraction of its outstanding common stock. Despite the good purposes about increasing the stock value, they had to make a loan of $1 million for he purchase. Because of the unreasonable conditions to pay dividends in December, the company will have a negative cash flow. Solution We inferred from the financial statements that the company can not afford to repay the loan in December, otherwise they will have negative cash flow. However, all the financial statements have consistency among them showing  this declining trend. They should offer a one month extention on the loan to indicate a reasonable solution and then should start repaying it early. The repayment process should be started Payment of $200,000 in September Payment of $100,000 in October No payment in November Payment of $350,000 in December These payments reduce the interest and final loan payment. Another solution is about the extention of one month till January with the final repayment of $700,000 once December accounts receivables are collected. Hampton will not able to make a dividend payment in December so holding the dividend payment till January will enable the cash flow positive and allows for December sales to be realized, therefore usable to maket he January final payment. Conclusion Hampton Machine Tool Company is not in a secure financial condition.There are many improvements needed to survive. For instance, in working capital’s quantity and quality, in profitability, in liquidity and for financial stability they should focus on new improvements. Again, the dividend payment should be delayed to January. Recommendation Since the company’s problems are mostly temporaray and the company past the analysis of credit, the Bank may grand both Hampton’s loan refinancing of the $1million loan to be paid on December 1979, end the additional $ 350,000 that Hampton wants to borrow (payable on January 31, 1980). However, its very much advisable for St. Louis National Bank to undertake further studies and collect more data such as industry ratios and data, prevailing interest rates, financial statements from prior years etc. to permit a better and more informed decision.

Realism and the Future of World Politics Essay

First and foremost it is important to remember that state interest or state preference operates in an anarchic environment. The international system is inherently unstable and is aptly characterized by widespread anarchy. Due to the absence of a suprastate or overarching Leviathan authority, states are placed in inevitable and perpetual competition, described as the security dilemma. This has been evidenced by the state of European affairs since 1789. Because of the anarchic nature of international affairs, states are perpetually concerned with their survival. For realists, the international system is a â€Å"dog-eat-dog world† and ensuring survival is paramount for any and all states. According to Hans Morgenthau, pioneering German political scientist and an early proponent of realist thought, due to the inherent instability of the international system, the fundamental national interest of all states is to â€Å"protect [its] physical, political, and cultural identity against encroachments by other nations† (Morgenthau, 1952). Specifically, threats to states are determined by their relative power vis-a-vis one others in the international system. The structure of the system – the distribution of power and capabilities state wide – is important because threats or challenges facing a state which affront the national interest should be â€Å"calculated according to the situation in which the state finds itself† (Waltz, 1979). Thus, power and security requirements are paramount in attempting to define state interest and what motivates states to act. Furthermore, Power and wealth supply the means for states to survive, to meet their security requirements, and thus to continue to compete in a system in which other states are necessarily either actual or potential threats. State officials ad policy analysts are therefore advised realistically to asses the distribution of power; they should overcome their ‘aversion to seeing problems of international politics as they are’ in order to objectively asses the national interest in light of the distribution of power. Every state, that is, must pursue its national interest â€Å"defined in terms of power† (Morgenthau 1952) because this is the surest road to security and survival (Weldes, 1999). If we apply the realist conception of states power and apply it to the future of the international world, conflict over resources and war will be a defining feature of the international system. Europe has been plagued by conflict since the late 18th century and despite global interdependence and the existence of multilateral organizations in the form of the UN and the European Union, there is little evidence to suggest that armed conflict is not the future of international affairs. Nationalism, a concept created in Europe, has been responsible for much armed conflict over the past three centuries. Nationalism in International Affairs Nationalism is an important force in international relations and has been so for centuries. As a basic principle of the international order, concepts of state sovereignty are intrinsic to our understanding of the world system. Accordingly, the international system is predicated upon the existence of nation-states and nationalism is a belief or sense of identity within the nation. The Treaty of Westphalia established the principle of state sovereignty, another fundamental principle of the international order which established the nation-state as an autonomous political entity. Similar to tribalism or a sense of social kinship, nationalism as a potent political force began in Europe in the late eightieth century and was connected with a decline in overall religiosity, the development of industrialization, Enlightenment thoughts and a concerted effort by political elites to â€Å"build states†. By inculcating a sense of nationalist fervor in the citizens of their respective countries, elites have been able to manipulate nationalism for political purposes. Mass mobilization towards a variety of specific causes through an appeal to nationalist sentiment has been used as a political tool for centuries. Although not exclusively a negative force, nationalism remains an important ordering principle of the international system and a force to be reckoned with (Waltz 2000). Concluding Remarks Keeping in mind our realist conception of state interest, conflict will be an inevitable feature of the international system in the next 50 years. Europe has descended into bloodshed and armed conflict and has been the feature of the European continent for centuries. When global war broke out in 1914 dreams of world peace and prosperity were shattered. Accordingly, the First World War was arguably one of the most traumatic episodes in the history of international affairs. Geopolitically speaking, the First World War (also described as WWI in this essay) was unprecedented in both scale and sheer loss of human life. Never before had the world witnessed such carnage and violence perpetuated through the use of modern technology. The First World War touched much of the world the implications of this conflict reverberated across the globe. In addition to WWI, Europeans states fought dozens of wars and were home to countless revolutions aimed at changing the political order. From the French Revolution to the Spanish Civil War and the â€Å"War to End All Wars†, World War II, the history of Europe since 1789 has been wrought with conflict with nationalism playing an important role in the outbreak of violence.