[en] A total of 82 patients who underwent spinal computed tomographic scan, in an 8-month period at the King Khalid University Hospital, Riyadh, Saudi Arabia, were analyzed for age, sex, the presence/absence, site, and type of ossification of the ligamentum flavum (OLF) as well as associated diseases. The OLF was radiographically present (bilaterally or unilaterally) as linear (74.5%) or nodular types (25.5%). The linear type was especially seen at the inner aspects of the ligamentum flavum. OLF was present in 35.4% of patients, and was seen at single and multiple levels in 51% and 41% of them, respectively. OLF was identified in a total of 47 levels in the study group and was associated with other disease in the spine in 38 (81%) of these levels. In none of the patients was OLF the cause of myelopathy. The incidence of OLF and its pathogenesis and significance are discussed. This paper is the first report of OLF from the Middle East. OLF in this part of the world is usually asymptomatic

[en] A case of occipital sequestrated (rudimentary) meningocele in a 2-year-old girl is presented. The swelling was noticed at birth and did not grow over time. The skull radiograph showed no bone defect and ultrasound and computed tomography examinations demonstrated cystic mass with no connection to dura. The aim of this report is to draw the attention of radiology literature readers to this entity and to elaborate on the role of imaging in the preoperative assessment of such cases. The relation of sequestrated meningocele to the other conditions with ectopic meningeal tissue in the scalp is addressed

[en] Objective: To report an observation of small high attenuation foci in the tract of external ventricular drain on computed tomographic (CT) scan after removal of the drain and propose an explanation for this observation. Methods: Six patients with small high attenuation foci in the ventricular drain tract seen on CT after removal of the drain were retrospectively identified. The CT studies before, during, and after ventricular drainage were reviewed for the size, shape, location, and time of appearance of these foci. Results: In all patients, the high attenuation foci in the drain's tract were identified on CT done within 24 h from removal of the drain. In one patient, the high attenuation focus was seen adjacent to the drain on the CT obtained while the drain was in place. The high attenuation foci maintained constant size and shape on serial follow-up CT, and had variable location along the drain's tract. None of the patients developed symptoms related to these foci. Conclusion: Small bone pieces from the calvarium after drilling for external ventricular drain can inadvertently be pushed into the brain parenchyma during drain insertion. Early identification of these pieces on CT after removal of the drain and their constant size and shape are the clues for their nature. Temporal evolution of CT findings does not support the possibility of calcification in a small infarction or hematoma in the tract of the drain

[en] This paper examines the role of energy efficiency and non-economic factors such as consumers' preferences, lifestyles and values (which have hitherto been ignored) in energy demand and CO_2 emissions modelling for Nigeria. We use a structural time series model to estimate various energy demand and CO_2 intensity models that take account of the aforementioned factors. We adopt preferred models from these estimates to analyse how energy demand and CO_2 emissions in Nigeria might evolve by generating three different future scenarios to 2025. We find energy efficiency and non-economic factors to influence energy demand and CO_2 emissions. The long-run income and price elasticities obtained differ significantly from those in existing studies that have ignored these salient factors. In a business-as-usual scenario, the results indicate that energy demand will continue to grow. Consequently, present policies do not sufficiently mitigate aggregate CO_2 emissions in Nigeria. The lesson for policy makers is that the extant policies introduced to restrain CO_2 emissions (from a production perspective) have to be combined with new policies that influence consumers' lifestyles and behaviours, develop energy efficient technologies and apply low tariffs on imported energy efficient appliances, to drive down CO_2 emissions from a consumption perspective. - Highlights: • We model energy demand and CO_2 emissions for Nigeria during 1971–2012. • We examine the role of energy efficiency and other non-economic factors (ExNEF). • We found energy efficiency and ExNEF to be significant determinants in the model. • Existing policies to restrain CO_2 emissions (from a production side) are insufficient. • Environmental policies also need to restrain CO_2 emissions (from a consumption side).

[en] Power electronic modules are key elements in the chain of power conversion. The application areas include aerospace, aviation, railway, electrical distribution, automotive, home automation, oil industry ... But the use of power electronics in high temperature environments is a major strategic issue in the coming years especially in transport. However, the active components based on silicon are limited in their applications and not suitable for those require both high voltages and high ambient temperatures. The materials with wide energy gap like SiC, GaN and diamond, have the advantage of being able to exceed these limits [1,2]. These materials seem adequate to extremely harsh temperature environments and allow the reduction of cooling systems, but also the increasing of switching frequency. (author)

[en] The thermoelastic interaction in an unbounded medium with a spherical cavity is studied using two-temperature generalized thermoelasticity theory. The medium is assumed to be initially quiescent. The inner surface of the cavity is taken traction free and subjected to a thermal shock. By the Laplace transformation, the basic equations are expressed in the form of a vector-matrix differential equation, which is solved by an eigenvalue approach. Some comparison have been shown in figures to estimate the effect of the two-temperature parameter.

[en] First, I would like to thank the IAEA and OECD for sponsoring this conference and the government of China for hosting the conference. It gives me great pleasure to address this conference. This is a very important conference dealing with nuclear power in the 21st century. Sudan as a developing nation experiences an increase in the energy demand of its people. This is due to an increase industrialization and urbanization. Sudan with the assistance of the IAEA has initiated a planning study for long term energy supply and demand. This study showed that by the year 2020 an energy gap between energy supply and demand will occur. According to this study Sudan need to consider the nuclear option as part of an energy mix. Accordingly, Sudan with the help of the IAEA has started a technical cooperation program aiming at understanding the necessary infrastructure needed for a nuclear power program. To implement this program two committees were formed. A technical committee to address the technical requirement for the project and a high administrative committee to give the necessary political support. Utilizing nuclear energy for peaceful purposes requires strong commitment towards issues of safety, security and safeguards of nuclear and radioactive material. As part of the infrastructure requirement, in Sudan we started the amendments of the legal and regulatory framework. A new atomic energy act is being drafted. The most important features of this act are that: It provide for the establishment of a separate independent regulatory authority which will deal with all regulatory aspects of radioactive sources and nuclear material. The act also covers areas like emergency preparedness, nuclear security, liability and others. The legal requirement of nuclear program is the adherences to certain international legal instrument. A national committee from the ministries of justice, foreign affairs and science and technology was formed to advice on the country position regarding the required legal framework. A nuclear power program requires a highly trained manpower. We started on some programs that would lead to the creation of the critical manpower required for this undertaking. Under Sudan academy of Sciences we implemented M.Sc. programs on: Radiation protection; Nuclear instrumentation and electronics; Nuclear Science and technology. A bachelor degree in nuclear engineering will start soon at Sudan university of Science and Technology. To support these educational programs and to train more in areas like reactor operation, reactor engineering and reactor physics, Sudan has discussed with the IAEA the possibility of acquiring a zero power reactor which will help as a training tool for the needed scientists and engineers. However, considering the nineteen issues under the three mile stones for the preparation of the necessary infrastructure required for a knowledgeable decision on the introduction of nuclear power, there are areas need to be addressed by the international community. An assured supply of fuel which is not subjected to discriminative measures apart from purely technical ones is still controversial. The spend fuel processing and the waste management is also a gray area. Further the availability of small and medium reactors that suit better the capacity on grids in developing country is far from available. By this allow me to conclude my speech and I wish the conference all the success. Thank you for your attention.

[en] British Columbia Hydro's Worth Project Team was founded to determine values for reliability for reference in evaluation of investment and operating decisions. Work to date has produced key preliminary values for specific outages and concepts for the shape of the relationship between value and these determinates of reliability worth, frequency, magnitude and duration. These values and concepts are described. The values are developed through an iterative, trial and refinement approach. The approach incorporates direct input from customers, common sense and judgement, and micro- and macro-economic concepts. Reliability worth values for reduced or prevented outages are presented for residential, commercial, small industrial and mixed sectors and various outage durations. Reliability worth values were obtained through customer surveys. Limitations of the reliability worth value are numerous and are listed. Study of cost vs magnitude of interruption using microeconomic models has shown that costly system improvements to reduce the possibility of widespread outages may not be justified. The case of exceptionally large area outages (blackouts) is examined. The cost vs frequency relationship was examined in terms of the economic concept of utility or satisfaction. Different loss/frequency characteristics are demonstrated for different customer classes. Customer value for reduced outage duration is expressed in a curve with flatter slope than that for eliminated outages. 2 refs., 6 figs

[en] The equilibrium configurations for static spherically symmetric self-gravitating perfect fluids in general relativity are considered. The fluid obeys an equation of state which is the extreme limit allowed by Hawking's strong energy condition. The new solutions found are generalized Einstein static universes which have a Killing horizon similar to the one from the vacuum Schwarzschild solution. (author)

[en] Objective: To determine the frequency of HBsAg, anti HCV antibodies and anti HIV antibodies amongst UNAMID employees attending our dental clinics. Study Design: Observational study. Place and Duration of Study: The study was carried out at Pakistan Field Hospital Level III, Nyala, Sudan from Oct 2011 to Dec 2011. Patients and methods: All patients who were to undergo some dental surgical procedure had their HBsAg, anti HCV antibodies and anti HIV antibodies status checked by immunochromatographic technique prior to the procedure. Results: Out of the 156 patients studied, HBsAg was detectable in 7.7% and anti HCV antibodies in 1.3% of the patients. None tested positive for anti HIV antibodies. Conclusion: Hepatitis B and C infections do occur in our patient population. However HIV infections are not seen. (author)