897 research outputs found
On Pôlya frequency functions II. : Variation-diminishing integral operators of the convolution type
Master of Science
thesisUnderground natural gas baseload storage facilities are a vital part of the world's natural gas infrastructure. These facilities allow Exploration & Production (E&P) and transmission pipeline companies to utilize natural gas assets year round while providing means for consistent gas supply throughout the year. The purpose of this thesis is to present a process in which a feasibility study can be conducted for a prospective baseload storage facility. This was accomplished by explaining 1) the theory of natural gas storage reservoir engineering; 2) geologic consideration for underground storage prospects; 3) design of a new underground baseload facility using decline curve analysis and hysteresis analysis; and 4) a detailed economic analysis of a storage prospect. A depleted natural gas reservoir was evaluated for its potential to become an underground baseload storage facility for natural gas. For this underground reservoir, it is estimated the Original Gas in Place (OGIP) was 59.4 Billion Cubic Feet (BCF) using hysteresis analysis. The cushion gas requirement was solved to be 50% of the OGIP, or 29.7 BCF. There is currently 7.4 BCF of native gas present in the reservoir. The required injection cushion gas requirement is estimated at 22.3 BCF. The maximum field deliverability was estimated to be 284.3 Thousand Cubic Feet per Day (MCF/D) at a reservoir pressure of 868.5 psia. The minimum field deliverability was estimated to be 83.8 MCF/D at a cushion gas pressure of 434.1 psia. Maximum and minimum deliverabilities assume 30 injection/withdrawal wells are present at 6 different well pads throughout the field. After analyzing three different economic scenarios for the prospective storage field it was determined this project is not economically feasible under current market conditions. Recommendations for future work include the operating company conducting a 3D seismic survey and re-evaluating the project using 3D reservoir simulation evaluating the possibilities of 1) using horizontal drilling to minimize number of wells, 2) simulate storage well performance if vertical wells are hydraulically fractured, and/or 3) simulate if the prospective storage facility can be pressurized over the original discovery pressure
Efficient transport and economic development: A transport survey analysis
Efficient transport and economic growth in a city or country are inter-related. The overall focus of the survey conducted was to find the travel habits of the residents in the city of Kuching (Malaysia), so as to weigh the prospects of economic development in future. The three objectives were to evaluate the efficiency of the local bus transportation system, to confirm on the usage of
car as the preferred mode of transport, and to identify areas of improvement to the system as well as analyzing the need for an alternative mode(s) of transportation. The quantitative and qualitative analysis is done on data to find the relationships between various variables measured. Car has been confirmed to be the popular mode of transport across the age groups, across the income groups and across the professions, whereas the bus transport was really not
significant. The study identified the important characteristics and priorities in the travel behavior of Kuching residents. The results of the study will be
significant in the planning of new economic developments that encourages the use of public transportation in Kuching city
Current trends in glioblastoma multiforme treatment: radiation therapy and immune checkpoint inhibitors.
Glioblastoma multiforme (GBM) is the most common primary brain cancer. Even with aggressive combination therapy, the median life expectancy for patients with GBM remains approximately 14 months. In order to improve the outcomes of patients with GBM, the development of newer treatments is critical. The concept of using the immune system as a therapeutic option has been suggested for several decades; by harnessing the body's adaptive immune mechanisms, immunotherapy could provide a durable and targeted treatment against cancer. However, many cancers, including GBM, have developed mechanisms that protect tumor cells from being recognized and eliminated by the immune system. For new immunotherapeutic regimens to be successful, overcoming immunosuppression via immune checkpoint signaling should be taken into consideration
Administration Economics Programme in Nigerian Universities: Problem and Suggestion
The article discussed the problems facing the administration of Economics programme in Nigerian higher institutions. Secondary data was used to support the points raised in the article. The secondary data were sourced from print material and online publication by recognized institutions and individual author. The article identified inadequate funding of Economics programme, inadequate Economics lecturers, and shortage of infrastructural facilities in Economics, institutional corruption, unstable academic calendar, poor staff development and brain-drain as the challenges facing the administration of Economics programme in the Nigerian higher institutions. To solve these challenges, hence, this article recommends: that the government should increase the funding of Economics programme, employ more lecturers, provide more infrastructural facilities in the Economics department, ensure stable academic calendar and fight all institutional corruption in the university system
Investing In Leadership, Governance And Management To Improve Quality Of Teaching And Learning: A Human Capital Perspective
While funding is undoubtedly necessary to promote the quality of the curriculum, teaching, and learning, funding in and by itself is not a guarantee to achieve equity and equality of outcomes. Accordingly, in some cases, such as the South African context, a sound funding regimen to address inequities and quality in education in the post-apartheid setting, the quality of leadership, governance and management are equally key and sometimes more critical to achieving sustainable quality and equity improvements in education, including the quality of matric learners. Five quintile 1s (non-fee paying schools) in the Fezile Dabi district in the Free State Province of South Africa were sampled for this study. The schools were used as samples because they formed what is known as non-performing schools in terms of their matric results for the 2009 and 2010 academic years. We used purposive sampling comprising schools that did not perform satisfactorily in their matric results and adopted an utilisation-focused strategy that could assist the Free State Department of Education to improve quality. The data were collected from School Management Teams comprising the school principals of the five schools and Heads of Department. Knowledge of how principals manage the curriculum in schools in South Africa is therefore limited. Although there are detailed normative frameworks (often from elsewhere) on what principals should do, there is little consideration of the reality of the work of principals, in particular contexts, and what they actually do. There was a concern about some HODs with regard to their content knowledge of the different subjects’ streams. There was an outcry of 45% of HODs in highly cognitive subjects, such as Mathematics, Accounting, and Physical Science, who did not possess the content knowledge required in their respective subjects’ streaming. Consequently, a statement was made concerning the level of leadership in high-focus subjects. Similarly, there is a perception that there should be a strong content knowledge from the HOD as an instruction leader as their subjects are regarded as highly skilled subjects
Investing In Leadership, Governance And Management To Improve Quality Of Teaching And Learning: A Human Capital Perspective
Published ArticleWhile funding is undoubtedly necessary to promote the quality of the curriculum, teaching, and learning, funding in and by itself is not a guarantee to achieve equity and equality of outcomes. Accordingly, in some cases, such as the South African context, a sound funding regimen to address inequities and quality in education in the post-apartheid setting, the quality of leadership, governance and management are equally key and sometimes more critical to achieving sustainable quality and equity improvements in education, including the quality of matric learners.
Five quintile 1s (non-fee paying schools) in the Fezile Dabi district in the Free State Province of South Africa were sampled for this study. The schools were used as samples because they formed what is known as non-performing schools in terms of their matric results for the 2009 and 2010 academic years. We used purposive sampling comprising schools that did not perform satisfactorily in their matric results and adopted an utilisation-focused strategy that could assist the Free State Department of Education to improve quality. The data were collected from School Management Teams comprising the school principals of the five schools and Heads of Department.
Knowledge of how principals manage the curriculum in schools in South Africa is therefore limited. Although there are detailed normative frameworks (often from elsewhere) on what principals should do, there is little consideration of the reality of the work of principals, in particular contexts, and what they actually do. There was a concern about some HODs with regard to their content knowledge of the different subjects’ streams. There was an outcry of 45% of HODs in highly cognitive subjects, such as Mathematics, Accounting, and Physical Science, who did not possess the content knowledge required in their respective subjects’ streaming. Consequently, a statement was made concerning the level of leadership in high-focus subjects. Similarly, there is a perception that there should be a strong content knowledge from the HOD as an instruction leader as their subjects are regarded as highly skilled subjects
The Principle of Convergent Restraint: A Failed Framework of Public Reason
Public reason liberalism (PRL), grounded in the deliberative democratic tradition, has been widely recognized as a kind of political deliberation, confined by a socially-established set of rules that govern an individual’s actions, that leads to the emergence of collectively-held valid norms. Despite its widespread adoption within liberal democratic theory, the concept of PRL has not gone without criticism and controversy. Kevin Vallier's influential work, Public Justification versus Public Deliberation: The Case for Divorce, for instance, offers a trenchant critique of the deliberative constraints implicit in dominant conceptions of PRL. Vallier argues that these constraints, which he sees as being primarily imposed on citizens themselves, sacrifice individual liberty for the sake of promoting social cohesion (Vallier, 2015). Instead, Vallier contends that liberals should focus less on regulating the behaviour of individual citizens within the public sphere, and more on regulating the reach of public officials, through what he calls the 'Principle of Convergent Restraint' (PCR). The PCR is a tripartite framework that governs the conditions under which coercive legislation may be justified in a liberal democracy. The PCR, according to Vallier, represents the optimal approach for formulating justificatory reasons for such laws, while concurrently upholding the tenets of liberty and diversity. I disagree with this assessment. The purpose of this paper, therefore, is not to endorse or rebuke PRL, but rather to identify, systematically, Vallier’s misinterpretations of PRL and the contradictions inherent in his conception of the PCR. The main arguments will be organized into three main sections, each addressing one of the three provisions of the PCR. In the first section, I will demonstrate that the first provision of the PCR fails to uphold a sufficiently rigorous standard for public justification. Subsequently, in the second section, I will argue that a proper interpretation of PRL obviates the need for the second provision of the PCR entirely. Finally, if I succeed in the first and second sections, my third section will expose the PCR's final provision as being inconsistent and devoid of any logical coherence
Interpretation of 2D Computer Tomography and 3D Reconstruction and Its Role in the Diagnosis of Facial Bone Fractures
INTRODUCTION:
Facial injuries are clinically significant because they are often complex in nature and may have serious functional and cosmetic sequelae. As a result of this accurate diagnostic evaluation is of prime importance. Modern imaging techniques especially the computerized tomography has revolutionized the diagnostic capabilities in this modern era.
For many years both surgeons and physicians relied on 2 dimensional radiography of the facial skeleton to evaluate facial injuries. However such radiographs were relatively difficult to interpret because of the interposition of bony landmarks and defects.
In the 1970`s the multi-slice 2D CT became more widespread and was better able to represent the defects in the facial skeleton. CT`s accurate representation of facial fractures and their spacial relationships facilitates surgical exploration, fracture reduction and the selection and contouring of rigid plates.
As a result of this the CT has decreased the complications resulting from delays in diagnosis and treatment including malunion, non-union, and other functional and aesthetic deficits that may require revision surgery.
Surgeons generally need to make their own evaluation of the degree of skeletal disruption revealed by the imaging studies when planning initial treatment of facial fractures.
Recently advances in computer software algorithms have permitted three-dimensional (3D) reconstructions of the facial skeleton from 2D CT images. These 3D images may further facilitate the diagnosis and treatment of facial injuries and numerous authors have suggested that such 3D images may prove superior to 2D CT for pre-surgical planning in complex trauma.
AIM OF THE STUDY:
This is prospective study of 35 patients who were diagnosed to have facial bone fractures and had undergone CT scanning for the same.
The study was designed to find out the efficacy of 3D CT and used 3 main criteria, which include ;
1. To determine various fracture sites on 2D CT.
2. To determine the various fracture sites on 3D CT .
3. To determine whether any additional information was obtained by 3D CT that was missed in 2D CT there by making 3D CT a mandatory investigation for facial bone fractures.
MATERIAL AND METHODS:
This is a prospective study of 34 cases for a duration of 2 years from August 2006 to August 2008. The study was conducted in the Department of Plastic and Reconstructive Surgery, CMC Vellore.
Patients coming to the Accident and Emergency Department with alleged history of road traffic accidents were clinically assessed .If a clinical diagnosis of facial bone fracture was made then the patients were initially subjected standard radiographic procedures including conventional X-Rays and then to 2D CT and if a diagnosis of LeFort fracture was made then a 3D CT was performed.
Images were manipulated to provide optimal 3D demonstration of the fractures, using proprietary software tools that permitted manipulating the level of transparency, altering the angle of lighting on surfaces, changing the color tone of the surfaces and selectively cropping the image to provide multiple viewing angles.
Each of the 2D CT scans were read by the co-investigator who was a board certified radiologist and the various fracture sites determined. The 3D CT scans were then evaluated by the principal
investigator for fractures and then both scans will be compared to see if any additional information was obtained.
The 2D and 3D scans were then randomized and reread by the principal investigator and radiologist and the data was statistically analyzed to see if 3D reconstruction played an important role in interpreting fractures and whether additional
information was obtained from the 3D CT and if this changed the surgical planning and thus had a bearing on the treatment modality.
The various fracture sites that were examined included the frontal bone, nasal bone, zygoma, zygomaticomaxillary buttress, nasomaxillary buttress, infraorbital margins on both sides and the mandible.
A total of 374 sites were examined for fractures on both the 2D and 3D separately. Associated injuries were also recorded. However soft tissue lacerations were not recorded as associated injuries.
Inclusion Criteria:
a) All patients within the ages of 15 to 60 years,
b) No associated co-morbid conditions,
c) Patients with associated bony and soft tissue injuries,
d) Patients with mild to moderate head injury.
Exclusion Criteria:
a) Children and patients more than 60 years of life,
b) Patients with co-morbid conditions,
c) Patients with severe head injury.
OBSERVATION AND RESULTS :
Total number of positive finding on 2D of Frontal bone fractures is 12, of which, 9 (75%) are classified as positive by 3D of Frontal bone and 3 (25%) are classified negative by the same. Of the negatives as per Frontal bone fractures on 2D, all of them are classified as negatives by 3d of frontal bone also. The measurement of agreement kappa = 0.795 (p < 0.001). Total number of positive finding on 2D of Right Frontozygomatic buttress is 9, of which, 7 (78%) are classified as positive by 3D of Right Frontozygomatic buttress and 2 (22%) are classified negative by the same. Of the negatives as per 2D of Right Frontozygomatic buttress, all of them are classified as negatives by 3D of Right Frontozygomatic also. The measurement of agreement kappa = 0.837 (p < 0.001). Total number of positive finding on 2D of Left Frontozygomatic buttress is 9, of which, 7 (78%) are classified as positive by 3D of Left Frontozygomatic buttress and 2 (22%) are classified negative by the same. Of the negatives as per 2D of Left Frontozygomatic buttress, all of them are classified as negatives by 3D of Left Frontozygomatic buttress also. The measurement of agreement kappa = 0.837 (p < 0.001). Total number of positive finding on 2D of Nasal bone fractures is 29, of which, 27 (93%) are classified as positive by 3D of Nasal bone fractures and 2 (7%) are classified negative by the same. Of the negatives as per 2D of Nasal bone fractures, all of them are classified as negatives by 3D of Nasal bone fractures also. The measurement of agreement kappa = 0.799 (p < 0.001). Total number of positive finding on 2D of Right Zygomaticomaxillary buttress is 27, of which, 25 (93%) are classified as positive by 3D of Right Zygomaticomaxillary buttress and 2 (7%) are classified negative by the same. Of the negatives as per 2D of Right Zygomaticomaxillary buttress , all of them are classified as negatives by 3D of Right Zygomaticomaxillary buttress also. The measurement of agreement kappa = 0.837 (p < 0.001).
DISCUSSION:
Although 2D axial and coronal CT is more accurate and more sensitive than 3D reformatting, numerous studies have explores the utility of 3D imaging. Three-dimensional images are created from the original 2D slices; therefore, there is no new information in the images and artifacts may be produced in the reformation process. Nonetheless, reconstructed 3D images may assist in the visualization of large comminuted, displaced and complex fractures involving multiple planes, particularly in regard to the midface.12 To accurately assess symmetry and fracture lines, reconstructed images must be angulated carefully to exclude any false positives.13 3D images provide only information regarding bony architecture; fat and muscle entrapment, encephaloceles, haematomas, and associated injuries must be assessed radiographically through 2D CT manipulation of soft-tissue windows.
CONCLUSION :
This study of 34 cases of Le Fort fractures has shown that 2D CT scanning has provided valuable information regarding the extent of fractures as well as various details regarding each fracture displacement.
The additional 3D CT reformatting that was done in each of these cases has also picked up large number of fractures. It is however evident that none of the fractures that were picked up by 3D CT reformatting were missed out by the 2D thereby giving a clear indication that 2D CT specificity was much greater.
As surgical repair of Le Fort fractures is governed by the principles of fracture reduction of facial pillars and since all these fractures can be picked up easily by 2D CT it is unnecessary to proceed with a 3D CT reformatting as this additional investigation does not change the management plan.
3D CT gives a more detailed idea to surgeon regarding spacial orientation of the various fracture sites but does not change the management plan.
Taking into consideration the vast difference if its cost it is at present an unnecessary investigation.
In the future as technology improves and costs of these investigations come down and assessment time becomes less 3D CT reformatting may become an integral part of diagnosing all Le Fort fractures but until that date it 2D remains the best investigation for interpreting simple facial bone fractures and those fractures that are not grossly comminuted
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