Evaluation of gamma ray spectrometric data processing techniques

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The Future of U.S. Natural Gas Production, Use, and Trade

Abstract and PDF report are also available on the MIT Joint Program on the Science and Policy of Global Change website (http://globalchange.mit.edu/)Two computable general equilibrium models, one global and the other providing U.S. regional detail, are applied to analysis of the future of U.S. natural gas as an input to an MIT study of the topic. The focus is on uncertainties including the scale and cost of gas resources, the costs of competing technologies, the pattern of greenhouse gas mitigation, and the evolution of global natural gas markets. Results show that the outlook for gas over the next several decades is very favorable. In electric generation, given the unproven and relatively high cost of other low-carbon generation alternatives, gas likely is the preferred alternative to coal. A broad GHG pricing policy would increase gas use in generation but reduce use in other sectors, on a balance increasing its role from present levels. The shale gas resource is a major contributor to this optimistic view of the future of gas, but it is far from a panacea over the longer term. Gas can be an effective bridge to a lower emissions future, but investment in the development of still lower CO2 technologies remains an important priority. Also, international gas resources may well prove to be less costly than those in the U.S., except for the lowest-cost domestic shale resources, and the emergence of an integrated global gas market could result in significant U.S. gas imports.American Clean Skies Foundation, with additional support from the Hess Corporation, the Agencia Nacional de Hidrocarburos (Columbia), the Energy Futures Coalition, and the MIT Energy Initiative

Temporal multiplexing with adaptive optics for simultaneous vision.

We present and test a methodology for generating simultaneous vision with a deformable mirror that changed shape at 50 Hz between two vergences: 0 D (far vision) and -2.5 D (near vision). Different bifocal designs, including toric and combinations of spherical aberration, were simulated and assessed objectively. We found that typical corneal aberrations of a 60-year-old subject changes the shape of objective through-focus curves of a perfect bifocal lens. This methodology can be used to investigate subjective visual performance for different multifocal contact or intraocular lens designs

Presbyopia:Effectiveness of correction strategies

Presbyopia is a global problem affecting over a billion people worldwide. The prevalence of unmanaged presbyopia is as high as 50% of those over 50 years of age in developing world populations due to a lack of awareness and accessibility to affordable treatment, and is even as high as 34% in developed countries. Definitions of presbyopia are inconsistent and varied, so we propose a redefinition that states “presbyopia occurs when the physiologically normal age-related reduction in the eye's focusing range reaches a point, when optimally corrected for distance vision, that the clarity of vision at near is insufficient to satisfy an individual's requirements”. Presbyopia is inevitable if one lives long enough, but intrinsic and extrinsic risk factors including cigarette smoking, pregnancy history, hyperopic or astigmatic refractive error, ultraviolet radiation, female sex (although accommodation is similar to males), hotter climates and some medical conditions such as diabetes can accelerate the onset of presbyopic symptoms. Whilst clinicians can ameliorate the symptoms of presbyopia with near vision spectacle correction, bifocal and progressive spectacle lenses, monovision, translating or multifocal contact lenses, monovision, extended depth of focus, multifocal (refractive, diffractive and asymmetric designs) or ‘accommodating’ intraocular lenses, corneal inlays, scleral expansion, laser refractive surgery (corneal monovision, corneal shrinkage, corneal multifocal profiles and lenticular softening), pharmacologic agents, and electro-stimulation of the ciliary muscle, none fully overcome presbyopia in all patients. While the restoration of natural accommodation or an equivalent remains elusive, guidance is gives on presbyopic correction evaluation techniques

Acute Traumatic Injury of the Larynx

Laryngeal trauma is rare but serious and potentially deadly injury. The prompt diagnosis and management of acute laryngeal trauma is necessary because the clinical presentation is variable depending on the location, severity, and mechanism of injury. Two case histories are presented: (1) case history A: a 53-year-old male, after motor vehicle accident, fractured the mid anterior thyroid cartilage and both aspects of the cricoid cartilage; however, this patient was asymptomatic from the above fractures; and (2) case history B: a 41-year-old male who sustained trauma to the chest, neck, and left arm after being struck by a large lead pipe which fractured the left aspect of the cricoid cartilage was symptomatic. The type rather than the severity of acute laryngeal injury and the mechanism of injury may be related to symptomatology. Acute laryngeal trauma should be recognized by trauma radiologists and emergency room physicians. Early diagnosis and management of acute laryngeal trauma may prevent unnecessary specialty consults and long-term complications

Implications of natural gas vehicle technologies on household transportation in the U.S.

Thesis (S.M. in Technology and Policy)--Massachusetts Institute of Technology, Engineering Systems Division, Technology and Policy Program, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 70-75).Transportation represents almost 28 percent of the United States' energy demand. Approximately 95 percent of U.S. transportation utilizes petroleum, the majority of which is imported. With significant domestic conventional gas resources, optimistic projections of unconventional natural gas resources, and the growing international liquefied natural gas (LNG) market, gas prices are expected to remain lower than oil. While natural gas currently provides approximately 24 percent of the United States' energy consumption, there has been no significant growth in the natural gas vehicle market in the past fifteen years. Natural gas has comparative environmental advantages to gasoline and diesel, with lower CO2 emissions per mega joule of fuel consumption. A natural gas powered vehicle fleet could reduce the country's fuel costs, dependence on imported fuel, and greenhouse gas emissions. To fully comprehend the future role of natural gas vehicles in the United States, all the major technological and market forces affecting the successful deployment of this vehicle technology must be analyzed interdependently under market and energy policy-regulated scenarios. I investigate the potential role of natural gas in transportation using a computable general equilibrium (CGE) model of the global economy that is resolved for the US and other major countries and regions. To do so, I add a dedicated compressed natural gas (CNG) vehicle option to the Emissions Prediction and Policy Analysis (EPPA) Model as an option to the conventional internal combustion engine (ICE) vehicle. The model projects changing prices of fuel and other goods over time, given specification of resource availabilities. With the CNG vehicle specification I am able to evaluate the effect of the CNG option on transportation emissions, oil imports, natural gas use, and other economic indicators. I consider different policy scenarios for the future, including the adoption of a targeted emissions cap policy to see how that affects the competitiveness of CNG vehicles. Several conclusions about the potential role of nature gas vehicles in the United States are drawn from this analysis. First, NG vehicles will reduce household transportation emissions in proportion to their share of the vehicle fleet. Second, stringent emissions policies will stimulate the penetration of natural gas vehicles, but high vehicle costs and infrastructure may hinder their deployment. There is a correlation between increased NG vehicle use and the reduction of oil imports. In the long term, development of cleaner alternative fuels with similar infrastructure to gasoline may hamper CNG vehicle growth.by Oghenerume Christopher Kragha.S.M.in Technology and Polic

Malignant Peripheral Nerve Sheath Tumor: MRI and CT Findings

This is a case report of a 56-year-old male with hypertension who presented with urinary retention and bowel incontinence. CT and MRI of the abdomen and pelvis showed a large complex cystic and solid enhancing mass in the right presacral space. Pathology biopsy result showed malignant peripheral nerve sheath tumor (MPNST) with extensive necrosis. The diagnosis of MPNST is extremely difficult due to the lack of (1) conclusive immunohistochemistry or unique chromosomal anomaly, (2) universal distinctive histopathology, and (3) clinical criteria. The clinical, radiologic, and histologic presentation of MPNST is important in its diagnosis. A rare case of MPNST that produced urinary retention and bowel incontinence is presented that may aid clinicians in the diagnosis of this rare clinical entity. Motor weakness, central enhancement, and immunohistochemistry may assist in the diagnosis of MPNST and differentiation between benign peripheral nerve sheath tumor (BPNST) and MPNST

Enhancement of local content in the upstream oil and gas industry in Nigeria : a comprehensive and viable policy approach

This report summarizes a study on private sector development in connection with the Nigerian upstream oil and gas industry. Three subprojects serve the basis for the report, whose task is to assess the enabling environment for private sector development in the Nigerian upstream petroleum industry and recommend ways of increasing and improving the capabilities of Nigerian supply and services companies. One subproject was undertaken by Kragha & Associates (K&A) in order to document the industrial base with regard to Nigeria's upstream oil and gas. The other subproject was carried through at Rogaland Research (RF), focusing on the industrial potential for Nigerian industry with regard to its domestic petroleum activities. The third project was undertaken at Institute for Research in Economics and Business Administration (SNF) applying a comparative and theoretical perspective on local industrial development related to upstream oil and gas. The three subprojects are summarized in this report, to form the basis for discussing trade-offs and dilemmas regarding the formulation and design of a policy to enhance sustainable industrial and economic growth