A study of the photoacoustic effect in ethylene gas

Ethylene, C2H4, is a plant hormone produced and released naturally by plants and soil microorganisms. This colorless, flammable gas has a slightly sweet odor usually only recognized by those who have handled ethylene before. In situ analyses of this gas and many other potentially harmful gases outside of the laboratory are often difficult to perform due to the lack of a portable yet reliable unit capable of precisely and accurately detecting and measuring the concentrations of these gases at trace gas concentrations of a few parts per billion. In this research project, photoacoustic spectroscopy was used to detect and measure the concentration of ethylene. Multiple aspects of the experimental setup were independently manipulated to determine each of their effects on the photoacoustic behavior exhibited. The data obtained in this research project was used to help formulate a discussion about what experimental conditions were most ideal for detection and measurement of ethylene using photoacoustic spectroscopy. It was determined that this technique was most reliable when the internal radius of the cavity resonator was small, the power of the light source was high, the concentration of ethylene gas was high, and the rotational frequency of the mechanical chopper was low. These experimental conditions should be considered by manufacturers when devising highly-sensitive, low-cost portable systems for the detection and measurement of ethylene gas both inside and outside the laboratory

The U.S. Economic Paradox after the 2008 Financial Crisis: Expansion of Money without Inflation

Although previous studies of the U.S. monetary policy and the Federal Reserve’s role as the national central bank have increased our understanding to the post-crisis economic transformation, they have not fully mentioned the unusual relationship between money supply and inflation since the 2008 financial crisis. To find the answer, I first analyze the key concepts of the U.S. modern currency and monetary base. Secondly, to recognize the issue, I calculate and compare the changes in inflation and money supply from 2009 to 2015, year by year. Lastly, I apply three principle economic theories to test the relationship between the U.S. money supply and inflation from 2009 to 2015, and they are (1) the quantity theory of money, (2) aggregate demand-aggregate supply, or AD-AS model paired with the Phillips curve, and (3) exchange rate theory. After all, I conclude that these three classical theory of monetary policy and inflation were not applicable for the post-crisis U.S. economy anymore

Justice Detained: The Effects of Deportation on Immigrant Families

In November 2002, driven by a growing awareness within the Asian and Pacific Islander immigrant communities that more and more people were getting deported, youth activists at AYPAL, based in Oakland, initiated a campaign to find out what was going on and what they could do about it. AYPAL found that the problem of deportation was much worse than the isolated incidents we had heard about, and it is only growing more severe. In 1996, Congress enacted the Illegal Immigration Reform and Immigrant Responsibility Act (IIRIRA), which made it a lot easier to deport immigrants, including many legal permanent residents who had lived in the United States for many years. They were considered deportable if they had committed any crime involving prison or probation time that added up to one year or more. (See "Overview of IIRIRA" section.)AYPAL's research findings:Hundreds of thousands of people are being deported every year to countries all around the world, and there was a huge increase in deportations from 1996 to 1998, coinciding with IIRIRA being implemented in April 1997.The overwhelming majority of "criminal removals" are for non-violent crimes.Deportations hurt families by potentially leaving hundreds of thousands of children who are left behind in poverty.Despite claims that immigrants are contributing to high crime rates, they are actually less likely than native-born citizens to commit crimes.Immigrants released from jail are less likely than the native born to be repeat offenders.Immigrants are being deported to countries that the US State Department deems too dangerous to travel to.Another reason besides IIRIRA for the huge increase in deportations is that many more people in general (both immigrants and native born) are being sent to prison and for longer sentences because of policy changes like "three strikes" and mandatory minimum sentencing

Migrant acculturation and consumption motivations : an empirical study of the Vietnamese

The study examines differences in cultural values and travel motivations between Vietnamese migrants (Viet Kieu) and Vietnamese in Vietnam. The study finds that Viet Kieu have acculturated and moved away from traditional cultural values and towards &ldquo;Western&rdquo; cultural Values. They are less motivated to travel by a desire to maintain home links than was anticipated by &ldquo;home&rdquo; Vietnamese. In promoting travel marketers may be able to use the level of acculturation to appeal to migrants links with both countries and thus complex messages may be required.<br /

Congenital aneurysm of the muscular interventricular septum associated with bifascicular block

Isolated congenital aneurysm of the muscular interventricular septum is rare. We present a patient with congenital aneurysm of the basal muscular ventricular septum, who also develops conduction abnormalities with first-degree heart block, right bundle branch block, and left posterior fascicular block. The case details the natural history of the aneurysm over a 10-year period follow-up during which the patient remained asymptomatic with evidence of regression of the aneurysm. Given the aneurysm\u27s location close to the proximal right bundle and left posterior fascicle, we believe that the cause for the aneurysm also injured both fascicles resulting in bifascicular block. The diagnosis of bifascicular block was confirmed using the electrocardiogram-derived vectorcardiography loops. These conduction abnormalities have remained stable. The case illustrates the utility of vectorcardiography in diagnosing bundle branch conduction defects. The case also illustrates the importance of anatomical considerations when encountering congenital heart defects

Abdominal intercostal hernia: a rare complication after blunt trauma.

Abdominal intercostal hernia (AIH) is uncommonly reported in the literature with only 20 cases reported to date.1–3 We report a case of a delayed incarcerated AIH secondary to blunt trauma from a motor vehicle accident in which the colon and diaphragm herniated through an associated chest defect that was repaired successfully through a transabdominal approach using primary repair of the defect in combination with onlay porcine patch reinforcement

Aircraft Lightning Electromagnetic Environment Measurement

This paper outlines a NASA project plan for demonstrating a prototype lightning strike measurement system that is suitable for installation onto research aircraft that already operate in thunderstorms. This work builds upon past data from the NASA F106, FAA CV-580, and Transall C-180 flight projects, SAE ARP5412, and the European ILDAS Program. The primary focus is to capture airframe current waveforms during attachment, but may also consider pre and post-attachment current, electric field, and radiated field phenomena. New sensor technologies are being developed for this system, including a fiber-optic Faraday polarization sensor that measures lightning current waveforms from DC to over several Megahertz, and has dynamic range covering hundreds-of-volts to tens-of-thousands-of-volts. A study of the electromagnetic emission spectrum of lightning (including radio wave, microwave, optical, X-Rays and Gamma-Rays), and a compilation of aircraft transfer-function data (including composite aircraft) are included, to aid in the development of other new lightning environment sensors, their placement on-board research aircraft, and triggering of the onboard instrumentation system. The instrumentation system will leverage recent advances in high-speed, high dynamic range, deep memory data acquisition equipment, and fiber-optic interconnect

Social Data Visualization System for Understanding Diffusion Patterns on Twitter: A Case Study on Korean Enterprises

Online social media have been playing an important role of creating and diffusing information to many users. It means the users can get cognitive influence to the other users. Thus, it is important to understand how the information can be diffused by interactions among users through online social media. In this paper, we design a social media monitoring system (called "TweetPulse'') which can analyze and show meaningful diffusion patterns (DP) among the users. Particularly, TweetPulse focuses on visualizing information diffusion in Twitter, given a certain time duration. Also, this work has investigated the relationships 1) between DP and event detecting, 2) between DP and emotional words, and 3) between DP and the number of followers of the users. Thereby, to understand the continuous patterns of the information diffusion, we propose two different types of analytic methods, which are 1) macroscopic approach and 2) microscopic approach. For evaluating the proposed method, we have collected and preprocessed the dataset during about 4 months (14 March 2012 to 12 July 2012). As a conclusion, TweetPulse has helped users to easily understand DP from a large scale dataset streaming through Twitter

A Fiber-Optic Aircraft Lightning Current Measurement Sensor

A fiber-optic current sensor based on the Faraday Effect is developed for aircraft installations. It can measure total lightning current amplitudes and waveforms, including continuing current. Additional benefits include being small, lightweight, non-conducting, safe from electromagnetic interference, and free of hysteresis and saturation. The Faraday Effect causes light polarization to rotate in presence of magnetic field in the direction of light propagation. Measuring the total induced light polarization change yields the total current enclosed. The system operates at 1310nm laser wavelength and can measure approximately 300 A - 300 kA, a 60 dB range. A reflective polarimetric scheme is used, where the light polarization change is measured after a round-trip propagation through the fiber. A two-detector setup measures the two orthogonal polarizations for noise subtraction and improved dynamic range. The current response curve is non-linear and requires a simple spline-fit correction. Effects of high current were achieved in laboratory using combinations of multiple fiber and wire loops. Good result comparisons against reference sensors were achieved up to 300 kA. Accurate measurements on a simulated aircraft fuselage and an internal structure illustrate capabilities that maybe difficult with traditional sensors. Also tested at a commercial lightning test facility from 20 kA to 200 kA, accuracy within 3-10% was achieved even with non-optimum setups

A Fiber-Optic Current Sensor for Lightning Measurement Applications

An optical-fiber sensor based on Faraday Effect is developed for measuring total lightning electric current. It has many unique capabilities not possible with traditional current sensors. Designed for aircraft installation, the sensor is lightweight, non-conducting, structure-conforming, and is immune to electromagnetic interference, hysteresis and saturation. It can also be used on windmills, lightning towers, and can help validate lightning detection network measurements. Faraday Effect causes light polarization to rotate when the fiber is exposed to a magnetic field in the direction of light propagation. Thus, the magnetic field strength can be determined from the light polarization change. By forming closed fiber loops and applying Ampere's law, measuring the total light rotation yields the total current enclosed. The broadband, dual-detector, reflective polarimetric scheme allows measurement of both DC component and AC waveforms with about 60 dB dynamic range. Three sensor systems were built with different sensitivities from different laser wavelengths. Operating at 850nm, the first system uses twisted single-mode fiber and has a 150 A - 150 KA range. The second system operates at 1550nm, uses spun polarization maintaining fiber, and can measure 400 A - 400 KA. Both systems were validated with rocket-triggered lightning measurements and achieved excellent results when compared to a resistive shunt. The third system operates at 1310nm, uses spun polarization maintaining fiber, and can measure approximately 300 A - 300 KA. High current measurements up to 200 KA were demonstrated at a commercial lightning test facility. The system was recently installed on an aircraft and flown near icing weather conditions