3,441 research outputs found
Transcripts for dissertation, "Iron fellows : commitment and activism in a poor people's movement"
No full textThis set contains transcripts from Marcos Perez's dissertation project. Data is available by request to interested scholars and students. Visitors may not download the files without express permission from the author. Visitors may not make copies of the transcripts, nor distribute any part of them separately. To request access, please contact [email protected]
Courageous women in media: Marcos and censorship in the Philippines
No full textWhen Philippine President Ferdinand Marcos declared Martial Law in 1972, press freedom became the first casualty in the country that once boasted of being the 'freest in Asia'. Printing presses, newspaper offices, television and radio stations were raided and padlocked. Marcos was especially fearful of the press and ordered the arrest of journalists whom he charged with conspiring with the 'Left'. Pressured into lifting martial law after nearly 10 years, Marcos continued to censor the media, often demanding publishers to sack journalists whose writing he disapproved of. Ironically, he used the same 'subversive writings' as proof to Western observers that freedom of the press was alive and well under his dictatorship. This article looks at the writings of three female journalists from the Bulletin Today. The author examines the work of Arlene Babst, Ninez Cacho-Olivares, and Melinda de Jesus and how they traversed the dictator's fickle, sometimes volatile, reception of their writing. Interviewed is Ninez Cacho-Olivare, who used humour and fairy tales in her popular column to criticise Marcos, his wife, Imelda, and even the military that would occasionally 'invite' her for questioning. She explains an unwritten code of conduct between Marcos and female journalists that served to shield them from total political repression
Investigation of core data reliability to support time-lapse interpretation in Campos Basin, Brazil
No full textA comparison between laboratory experiments and log measurements was done to investigate the effect of core damage on compressional wave velocities. This was done using 43 rock samples extracted from a 45 meters thick turbidite reservoir. We used Gassmann fluid substitution to obtain low-frequency saturated velocities from dry core measurements (thus mitigating the dispersion effects) taken at reservoir pressure. To mitigate the scale effect (or under-representation of reservoir properties by a number of small cores), we apply a correction for small mismatch between the core and log porosities. Comparison of these computed velocities with the sonic log measurements shows very good agreement. This confirms that for this particular portion of the reservoir the effect of core damage on ultrasonic measurements is below the measurement error. The results suggest that stress sensitivity of elastic properties as obtained from ultrasonic measurements is adequate for quantitative interpretation of time-lapse seismic data
Producing Ferdinand E. Marcos, the Scholarly Author
No full textThisarticle discusses the compelling evidence—found in various primaryand secondary sources and analyzed through methods drawn from bookhistory and plagiarism detection—that not one of the books authored byPres. Ferdinand E. Marcos was actually written by him. Thearticle alsoshows how many of “Marcos’s” books had either plagiarized content(e.g., republishing contents from previous works) or were “padded” withlengthy appendices. It also explains the seemingly far-reaching distributionnetwork of these books. Lastly, thearticle looks into how these books,although they have not been republished for decades, continue to servetheir intended functions.KEYWORDS: FERDINAND E. MARCOS • BOOK HISTORY • GHOSTWRITING • PLAGIARISM• ADRIAN CRISTOBA
CFD based aerodynamic redesign of a Marcos LM600
No full textThe final years of the 1960s mark the introduction of aerodynamics to the field of motorsport and they have grown to be inextricably connected ever since. The competing cars in nearly every motorsport category are fitted with aerodynamic devices while Formula One teams actually have departments that are primarily concerned with the aerodynamic design of their vehicles. The GT-class is another motorsport category that hosts cars that are predominantly shaped with the aim to optimize aerodynamic efficiency. The Marcos LM600 is one of the cars that competes in the GT-class and forms the sculpture of this thesis. The subject of this thesis is to enhance the aerodynamic characteristics of the Marcos LM600 through utilization of Computational Fluid Dynamics (CFD). This implies that on going through this report a number of modifications to the Marcos LM600 will be presented with the aim of obtaining an aerodynamically improved racing car. In a sense the Marcos LM600 thus resembles a sculpture that assumes its final shape after a succession of modifications. The aerodynamic characteristics that are of primary significance to a racing car are the downforce and drag. The obvious target is to maximize the downforce and downforce-to-drag ratio. Apart from this force ratio, the downforce distribution between the wheel axes is another important racing car characteristic. The actual handling stability of the car is determined by the force balance between the front and rear wheels. Too much ”grip” on the front wheels causes oversteer, while too much rear wheel grip causes understeer. Thus when designing racing cars, the aerodynamicist should take into account the front wheel and rear wheel downforce and to obtain either a vehicle with neutral steer or slightly oversteer1. However, vehicle handling is beyond the scope of this thesis, which is why the Marcos LM600 will only be optimized in terms of downforce and drag, leaving out their effect on the vehicle stability.Aerospace Engineerin
Investigation of pressure and saturation effects on elastic parameters: an integrated approach to improve time-lapse interpretation
No full textTime-lapse seismic is a modern technology for monitoring production-induced changes in and around a hydrocarbon reservoir. Time-lapse (4D) seismic may help locate undrained areas, monitor pore fluid changes and identify reservoir compartmentalization. Despite several successful 4D projects, there are still many challenges related to time-lapse technology. Perhaps the most important are to perform quantitative time-lapse and to model and interpret time-lapse effects in thin layers. The former requires one to quantify saturation and pressure effects on rock elastic parameters. The latter requires an understanding of the combined response of time-lapse effects in thin layers and overcoming seismic vertical resolution limitation.This thesis presents an integrated study of saturation and pressure effects on elastic properties. Despite the fact that Gassmann fluid substitution is standard practice to predict time-lapse saturation effects, its validity in the field environment rests upon a number of assumptions. The validity of Gassmann equations, ultimately, can only be tested in real geological environments. In this thesis I developed a workflow to test Gassmann fluid substitution by comparing saturated P-wave moduli computed from dry core measurements with those obtained from sonic and density logs. The workflow has been tested on a turbidite reservoir from the Campos Basin, offshore Brazil. The results show good statistical agreement between the P-wave elastic moduli computed from cores using the Gassmann equations and the corresponding moduli computed from log data. This confirms that all the assumptions of the Gassmann theory are adequate within the measurement error and natural variability of elastic properties. These results provide further justification for using the Gassmann theory to interpret time-lapse effects in this sandstone reservoir and in similar geological formations.Pressure effects on elastic properties are usually obtained by laboratory measurements, which can be affected by core damage. I investigated the magnitude of this effect on compressional-wave velocities by comparing laboratory experiments and log measurements. I used Gassmann fluid substitution to obtain low-frequency saturated velocities from dry core measurements taken at reservoir pressure, thus mitigating the dispersion effects. The analysis is performed for an unusual densely cored well from which 43 cores were extracted over a 45 m thick turbidite reservoir. These computed velocities show very good agreement with the sonic-log measurements. This is encouraging because it implies that core damages that may occur while bringing the core samples to the surface are small and do not adversely affect the measurement of elastic properties on these core samples. Should core damage have affected our measurements, we would have expected a systematic difference between properties measured in situ and on the recovered. This confirms that, for this particular region, the effect of core damage on ultrasonic measurements is less than the measurement error. Consequently, stress sensitivity of elastic properties as obtained from ultrasonic measurements are adequate for quantitative interpretation of time-lapse seismic data.In some circumstances, stress sensitivity may not be obtained by ultrasonic measurements. Cores may be affected by damage, bias in the plugging process and scale effects and therefore may not be representative of the in situ properties. Consequently it is desirable to obtain this dependence from an alternative method. This other approach ideally should provide the pressure - velocity dependence from an intact rock. Few methods can sample the in situ rock. Seismic, for instance, provides in situ information, but lacks vertical resolution. Well logs, on the other hand, can provide high vertical resolution information, but usually are not available before and after production changes. I propose a method to assess the in situ pressure - velocity dependence using well data. I apply this method to a reservoir made up of sandstone. I used 23 wells drilled and logged in different stages of development of a hydrocarbon field providing rock and fluid properties at different pressures. For each well logged at a specific time, pore pressure, velocity and porosity, among other properties, are known. Pore pressure is accessed from a Repeat Formation Tester (RFT). As a field depletes and new wells are drilled and logged, similar data sets related to different stages of depletion are available. I present an approach expanding Furre et al. (2009) study incorporating porosity and obtaining a three dimensional relationship with velocity and pressure. The idea is to help to capture rock property variability.Quantitative time-lapse studies require precise knowledge of the response of rocks sampled by a seismic wave. Small-scale vertical changes in rock properties, such as those resulting from centimetre scale depositional layering, are usually undetectable in both seismic and standard borehole logs (Murphy et al., 1984). I present a methodology to assess rock properties by using X-ray computed tomography (CT) images along with laboratory velocity measurements and borehole logs. This methodology is applied to rocks extracted from around 2.8 km depth from offshore Brazil. This improved understanding of physical property variations may help to correlate stratigraphy between wells and to calibrate pressure effects on velocities, for seismic time-lapse studies.Small scale intra-reservoir shales have a very different response from sands to fluid injection and depletion, and thus may have a strong effect on the equivalent properties of a heterogeneous sandstone reservoir. Since shales have very low permeability, an increase of pore pressure in the sand will cause an increase of confining pressure in the intra-reservoir shale. I present a methodology to compute the combined seismic response for depletion and injection scenarios as a function of net to gross (NTG or sand – shale fraction). This approach is appropriate for modelling time-lapse effects of thin layers of sandstones and shales in repeated seismic surveys when there is no time for pressure in shale and sand to equilibrate. I apply the developed methodology to analyse the sand - shale combined response to typical shale and sandstone stress sensitivities for an oil field located in Campos Basin, Brazil. For a typical NTG of 0.6, there is a difference of approximately 35% in reflection coefficient during reservoir depletion from the expected value if these shales are neglected. Consequently, not considering the small shales intra-reservoir may mislead quantitative 4D studies.The results obtained in this research are aimed to quantify pressure and saturation effects on elastic properties. New methodologies and workflows have been proposed and tested using real data from South America (Campos Basin) datasets. The results of this study are expected to guide future time-lapse studies in this region. Further investigations using the proposed methodologies are necessary to verify their applicability in other regions
Testing Gassmann fluid substitution: sonic logs versus ultrasonic core measurements
No full textAlthough Gassmann fluid substitution is standard practice for time-lapse studies, its validity in the field environment rests upon a number of underlying assumptions. The impact of violation on the predictions of Gassmann equations can only ultimately be validated by in situ testing in real geological environments. In this paper we show a workflow that we developed to test Gassmann fluid substitution by comparing saturated P-wave moduli computed from dry core measurements against those obtained from sonic and density logs. The workflow has been tested on 43 samples taken from a 45 m turbidite reservoir from the Campos Basin, offshore Brazil. The results show good statistical agreement between the P-wave elastic moduli computed from cores using the Gassmann equation with the corresponding moduli computed from log data. This confirms that all the assumptions of the Gassmann are adequate within the measurement error and natural variability of elastic properties. These results provide further justification for using the Gassmann theory to interpret time-lapse effects in this sandstone reservoir and in similar geological formations
4D seismic spectral decomposition over a presalt carbonate reservoir: A feasibility study
No full textTesting Gassmann fluid substitution using sonic logs and core measurements in a sandstone reservoir
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