Review Paper Research Example | Topics and Well Written Essays - 1750 words

Review - Research Paper Example d the design, the InAlAs-InGaAs-lnP lattice matched epitaxial layers were developed by the organo metallic vapor phae epitaxy on the lnP:Fe substrate. The layer structure consisted of 25nm lnP:Fe buffer layer, a 50nm ln(Ga,AL) graded layer, 300-nm n+ -InP:Si (6 10 cm ohmic contact layer and a 50-nm InAlAs Schottky-barrier enhancement layer. The graded layer was incorporated into the structure to remove conduction and valence band discontinuities that tend to degrade the high frequency performance citric acid:H202 was used to achieve an anisotropic mesa etch (Wohlmuth, Seo, Fay, Caneau, &. Adesida, 2). The etch profile enabled a Ti: Au interconnection between the top ITO Schotty contact and the microwave probe pads. RF magnetron was used to deposit the ITO film (thickness 320nm, refractive index of 2.05) sputtering in the argon environment. The experimental results showed that the device had a low knee voltage of about 0.39v, which is in accordance to the background doping concentration of 4x1014 cm-3 (Wohlmuth et al, 2). The responsive of the devices was between 0.55-0.60 A/W at wavelength of 1.31 mm and 0.563-0.583 for 1.55 mm at a bias of 5V. The dark current density of the Schottky contact increased as the diameter of the devices was reduced. This implied that the dark current of the devices is due to the surface-state conduction on the edges of the mesa rather than across the barrier contact (Wohlmuth, Seo, Fay, Caneau, &. Adesida, 3). At 100 mm, the lowest dark current was exhibited at 8.87x10-5 A/cm-2 at a bias of 5V. The frequency of the device was determined using the HP83420A light wave test set of wavelength 1.55 mm, 50ohm characteristic impedance. The 3-dB cutoff frequency at 10V for 11, 50, 25, 20, 15 diameter devices was found to be 2.5, 10.3, 21.2, 23.7, 25GHZ respectively. The high responsiveness was up to 0.60A/W for 1.31 light and 0.583 A/W for 1.55 mm (Wohlmuth, Seo, Fay, Caneau, &. Adesida, 4). The paper aimed at investigating the

Written Review Essay Example | Topics and Well Written Essays - 2000 words

Written Review - Essay Example On the contrary, an association with increased risk of breast cancer has been discovered. HRT could still be used for post-menopause syndromes. Nevertheless, it should not be used as primary prevention for CVDs and bone density diseases. Women’s health is considered to be one of the most crucial medical topics today. Such is why treatments of post menopausal conditions of women continue to be a topic largely investigated. Hormone replacement therapy (HRT) is noted to be widely used among the more developed countries (Nelson, 2008). In the United States, about one third of their population of women report to be users of HRT (Sharma, 2003). In this paper, the author aims to present the advantages and disadvantages of HRT. A review of 3 scientific medical journals will be presented and thoroughly appraised for its validity and reliability. The author hopes that by doing such, a clearer understanding of the benefits and risks of HRT will be achieved. According to Sharma (2003), hormone replacement therapy is widely used by women today because of its ability to treat symptoms of menopause and the chronic conditions associated with it. In his paper, Hormone Replacement Therapy in Menopause: Current concerns and considerations (Sharma, 2003), he launched into an in-depth critical analysis of past studies concerning HRT. His methodology involved a highly specific Medline research for papers written and submitted in the years 1997 to 2003. Only those written in the English language and have an abstract readily available were included in his study (Sharma, 2003). The specific key words used for his study involved hormone replacement therapy, estrogen replacement therapy, menopause and hormone replacement. He was also very thorough and set a criterion in which he would only include materials that are original. According to Sharma (2003) the use of HRT has a strong correlated effect on vasomotor symptoms.