Search

Highlights • Code comparisons build confidence in simulators to model interdependent processes. • International hydrate reservoir simulators are compared over five complex problems. • Geomechanical processes significantly impact response of gas hydrate reservoirs. • Simulators yielded comparable results, however many differences are noted. • Equivalent constitutive models are required to achieve agreement across simulators. Geologic reservoirs containing gas hydrate occur beneath permafrost environments and within marine continental slope sediments, representing a potentially vast natural gas source. Numerical simulators provide scientists and engineers with tools for understanding how production efficiency depends on the numerous, interdependent (coupled) processes associated with potential production strategies for these gas hydrate reservoirs. Confidence in the modeling and forecasting abilities of these gas hydrate reservoir simulators (GHRSs) grows with successful comparisons against laboratory and field test results, but such results are rare, particularly in natural settings. The hydrate community recognized another approach to building confidence in the GHRS: comparing simulation results between independently developed and executed computer codes on structured problems specifically tailored to the interdependent processes relevant for gas hydrate-bearing systems. The United States Department of Energy, National Energy Technology Laboratory, (DOE/NETL), sponsored the first international gas hydrate code comparison study, IGHCCS1, in the early 2000s. IGHCCS1 focused on coupled thermal and hydrologic processes associated with producing gas hydrates from geologic reservoirs via depressurization and thermal stimulation. Subsequently, GHRSs have advanced to model more complex production technologies and incorporate geomechanical processes into the existing framework of coupled thermal and hydrologic modeling. This paper contributes to the validation of these recent GHRS developments by providing results from a second GHRS code comparison study, IGHCCS2, also sponsored by DOE/NETL. IGHCCS2 includes participants from an international collection of universities, research institutes, industry, national laboratories, and national geologic surveys. Study participants developed a series of five benchmark problems principally involving gas hydrate processes with geomechanical components. The five problems range from simple geometries with analytical solutions to a representation of the world's first offshore production test of methane hydrates, which was conducted with the depressurization method off the coast of Japan. To identify strengths and limitations in the various GHRSs, study participants submitted solutions for the benchmark problems and discussed differing results via teleconferences. The GHRSs evolved over the course of IGHCCS2 as researchers modified their simulators to reflect new insights, lessons learned, and suggested performance enhancements. The five benchmark problems, final sample solutions, and lessons learned that are presented here document the study outcomes and serve as a reference guide for developing and testing gas hydrate reservoir simulators.

The Telescope Array experiment studies ultra high energy cosmic rays using a hybrid detector. Fluorescence telescopes measure the longitudinal development of the extensive air shower generated when a primary cosmic ray particle interacts with the atmosphere. Meanwhile, scintillator detectors measure the lateral distribution of secondary shower particles that hit the ground. The Middle Drum (MD) fluorescence telescope station consists of 14 telescopes from the High Resolution Fly’s Eye (HiRes) experiment, providing a direct link back to the HiRes measurements. Using the scintillator detector data in conjunction with the telescope data improves the geometrical reconstruction of the showers significantly, and hence, provides a more accurate reconstruction of the energy of the primary particle. The Middle Drum hybrid spectrum is presented and compared to that measured by the Middle Drum station in monocular mode. Further, the hybrid data establishes a link between the Middle Drum data and the surface array. A comparison between the Middle Drum hybrid energy spectrum and scintillator Surface Detector (SD) spectrum is also shown.

Aim To investigate the computed tomography (CT) findings in patients with stage IE/IIE extranodal natural killer/T-cell lymphoma (ENKTL) arising in the nasal cavity and to evaluate whether imaging findings revealed by CT have prognostic value. Materials and methods The CT findings of 62 patients diagnosed with IE/IIE ENKTL arising in the nasal cavity were retrospectively reviewed. Imaging findings were investigated, and evaluated imaging findings were analysed for the prognostic value of overall survival (OS) and disease-free survival (DFS). Results Of the 62 patients, 21 (34%) presented with a superficial infiltrative, 38 (61%) with a mass forming, and three (5%) with a combined pattern. Of all imaging findings, local invasiveness (n = 26, 42%), including bony destruction, erosion, or soft-tissue involvement, was the only independent prognostic factor for OS [p = 0.008; hazard ratio (HR): 3.85; 95% confidence intervals (CI): 1.42–10.44] and DFS (p = 0.001; HR: 4.25; 95% CI: 1.72–10.47). In a subgroup analysis of 36 cases with no local invasiveness, a superficial infiltrative pattern in one nasal cavity was a positive prognostic factor for OS (p = 0.028) and DFS (p = 0.008). Conclusion Imaging findings at CT provided clinically useful predictions for treatment outcomes. Local invasiveness revealed by CT findings was a strong prognostic factor for poor OS and DFS. In addition, in patients with no local invasiveness, a superficial infiltrative pattern in one nasal cavity predicted favourable OS and DFS.

Category:Basic Sciences/BiologicsIntroduction/Purpose:In the last two decades, several multi-segmental foot models (MFMs) have been introduced for the in vivo analysis of dynamic foot kinematics. However, the literature has not yet sufficiently described normal gait patterns in normal children and adolescents. Normal range of gait pattern should be established before applying gait analysis clinically in order to assess and treat pathological gait patterns. The purpose of this study is to suggest normal foot kinematics of clinically normal children and adolescents using three dimensional multi-segment foot model (3D MFM). Using this data, we will be able to distinguish between normal and abnormal gait more precisely in pediatric population and to evaluate gait improvement by certain treatment methods.Methods:One-hundred fifteen children and adolescents without anatomical or functional abnormalities of foot were involved. Fifty-seven individuals were boys and 58 were girls. The mean age was 11.4 years (rang...

We successfully developed highly scalable and cost-effective PCRAM technology based on 0.007um2 (4F2, 84nm pitch) sized novel cell scheme. The chip size and density are 33.207mm2 and 1Gb. The device functionality and reliability were clearly demonstrated through fully integrated chip, which showed a promising feasibility for productive NVM applications.

As sewage showing low C/N ratio in Korea has a small, but considerable amount of easily biodegradable organics, it is difficult to remove nutrients effectively. Approximately 11,434 tons of daily food waste that contain a lot of organic materials has been produced. The applicability of food waste as an external carbon source was examined in a pilot-scale BNR (biological nutrients removal) process for about 180 days. As the supply of the external carbon increased, the average removal efficiencies of T-N and T-P increased from 53% and 55% to 97% and 93% respectively. VFAs (volatile fatty acids) concentration of the external carbon source strongly affects denitrification efficiency and EBPR activity. EBPR (enhanced biological phosphorus removal) activity increased when T-N removal efficiency increased from 78% to 97%. In this study, several kinds of intracellularly stored PHAs (poly-hydroxyalkanoates) were observed. These were composed of 31% of 3HB (poly-3-hydroxybutyrate), 47% of 3HV (poly-3-hydroxyvalerate), 9% of 3HH (poly-3-hydroxyhexanoate), 5% of 3HO (poly-3-hydroxyoctanoate), and 2% of 3HD (poly-3-hydroxydecanoate) in biomass.

Aluminum (Al) has been widely used as an interconnecting material for integrated circuits. As the manufacturing of integrated circuits moves toward sub-quarter-micron design rules, there is a strong need for Al etching process with thin Photo Resist (PR). This leads to even more challenging with more complicated Al etching schemes and smaller width of thicker Al line (

A 110 V/600 A, highly stabilized power supply has been installed at the Korea Cancer Center Hospital (KCCH) in Seoul, to energize a water-cooled, resistive, high field research magnet for a cyclotron. The power supply achieves a long term current stability of 20 ppm over one hour period with a short term ripple and noise variation of

A large-scale underground railway construction project which is called the Second Phase of Seoul Subway consisted of 4 Lines from Line 5 to 8 was launched in Seoul in the early 1990s to share the increasing surface traffic volume. While constructing Line 5 which was the earliest planned Line in the Second Phase of Seoul Subway, 5 cave-in collapses took place in the central urban area in Seoul, which resulted in huge property losses to adjacent areas and project delay. A tunnel collapse may give rise to a potential for injury to the public or significant damage to the built environment. This paper presents and reviews the 5 cave-in collapses. Ground conditions, work environments, failure mechanisms and remedial works were analyzed and compared. Lessons from serial collapses were described in terms of both technical and non-technical aspects. It is concluded that safe and sound construction of tunnel requires well planned technical review process and management of nontechnical aspects involved are also important in ensuring safety of tunnelling. (A) This paper was presented at Safety in the underground space - Proceedings of the ITA-AITES 2006 World Tunnel Congress and the 32nd ITA General Assembly, Seoul, Korea, 22-27 April 2006. For the covering abstract see ITRD E129148. "Reprinted with permission from Elsevier".

For the purpose of designing and analyzing the stability of the B-tunnel which is a part of the Korea Train Express (KTX) Kyungbu Line and is planned to pass through the existing Kyungbu Expressway as well as the Yangsan Fault zone, the in-situ stress regime on this site has been measured by hydraulic fracturing tests to compare with the geological survey results. The Yangsan Fault is one of the major faults in Korea. Apart from a fold that shows the ductile deformation behavior, a fault shows a characteristic of the brittle deformation behavior and it is very important to perform a drastic survey on the fault to get the information on shape, dimension, mechanical properties, and so forth. Considering the impossibility of any borehole tests in fault zone, the authors used the two boreholes which are excavated in a base rock at both sides of the Yangsan fault. The hydraulic fracturing test results are proven to be in accord with the geological survey results. In other words, the geological site investigation let us know that the direction of fault movement is NS to NNE, and the geotechnical results by hydraulic fracturing tests show that the direction of the maximum horizontal principal stress is 6 to about 24 degrees from the true north. In-situ stress measurements on and around the fault zone are known to be uncommon all over the world, and this study is the first case in Korea. In view of this, the authors insist that this result will be helpful to analyze the stability of the B-tunnel, and can be applied to other similar cases in tunnel construction field. (A) This paper was presented at Safety in the underground space - Proceedings of the ITA-AITES 2006 World Tunnel Congress and the 32nd ITA General Assembly, Seoul, Korea, 22-27 April 2006. For the covering abstract see ITRD E129148. “Reprinted with permission from Elsevier”.

The design, fabrication, and experimental implementation of the one-patch microstrip antenna coupled with an H-shaped aperture are presented. The presented antenna has a wide bandwidth, high gain, and low cross-polarisation levels with only one-patch. The measured bandwidth of this antenna is 56.2% for the voltage standing wave ratio /spl les/2.0. The cross-polarisation level is below -18.2 dB at the E-plane and below -25.7 dB at the H-plane. The maximum gain at 2.05 GHz is 10.4 dBi and the 3 dB gain bandwidth with a centre frequency at 2.17 GHz is 24%.

Fibrous dysplasia should be considered in the differential diagnosis of tumors in the face and skull. The lesion is often present already in childhood and usually is most active during the general body and bone growth period. Microscopically the lesion consists of irregularly calcified and fibrous bone trabeculae. The rate of malignant degeneration is reported to be 0.4%. The main symptom is a unilateral swelling, and the disconfiguration may be remarkable without pain or other obvious symptoms. On roentgenograms the bone at the site of the lesion appears spongy with a homogeneous, fibrous-looking pattern and a thin egg-shell type of boundary. Sometimes, instead, a dissolution of the fibrous connective tissue occurs resulting in cystformations. The treatment is surgical removal of the diseased tissue; radical, mutilating operations are, however, not indicated. Twelve cases are reported. The lesion occurred in 7 males and 5 females, the maxilla was involved in 8 cases, the mandible in 2 cases, the frontal bone in 1 and the temporal bone in 1. The average duration of the illness was 8 years and the average age at onset around 17 years. Pronounced disconfiguration was seen in most cases, and extensive surgery was necessary in 8 of the patients. Malignant degeneration was not seen.