317 research outputs found
Department of Defense Hazardous Waste Site Remediation Issues in the Republic of Korea
The purpose of this research was to provide information to DoD decision makers regarding factors influencing hazardous waste site remediation policy for South Korea. This study addressed: International agreements and U.S. and South Korean laws and policies relevant to hazardous waste sites; objectives of DoD environmental policy makers; extent and effects of soil and groundwater contamination; cleanup precedents set in other foreign countries; availability of resources and technical capabilities to investigate and remediate hazardous waste sites in South Korea; and opportunities for cooperation between the U.S. and South Korean military with regard to hazardous waste site remediation. Data were collected and compared using triangulation methodology. This research resulted in identification of multiple factors which have an impact on promulgation of DoD hazardous waste site remediation policy for South Korea to include: (1) human health risk; (2) Congressional support for remedial actions overseas; (3) cleanup precedents set in other foreign countries; (4) Korean and U.S. perceptions; (5) Korean environmental law; and, (6) impact of contaminated sites on wartime capabilities. More study is required to assess the influence each issue has on DoD hazardous waste site remediation policy for Korea based on the values of policy makers
Comparative study between purse–string suture and peritoneal disconnection with ligation techniques in the laparoscopic repair of inguinal hernia in infants and children
Background Laparoscopic hernia repair in children is becoming more popular nowadays. A lot of laparoscopic techniques were described to repair inguinal hernia in infants and children; however, there are few reports on laparoscopic disconnection of the hernia sac at internal inguinal ring (IIR) as a method for hernia repair.Purpose The objective of this study was to compare intracorporeal purse–string suturing leaving the hernia sac in continuity and laparoscopic disconnection of the hernia sac at IIR and proximal closure of the peritoneum for repair of inguinal hernia in infants and children. A randomized prospective study was carried out in the Pediatric Surgery Unit of Alexandria University Hospitals (Alexandria, Egypt) on 40 male children.Patients and methods Forty male patients (48 repairs) were randomized into two equal groups (n= 20). Group A was subjected to intracorporeal purse–string suturing around the IIR leaving the hernia sac in continuity. Group B was subjected to disconnection of the hernia sac from the parietal peritoneum at the level of IIR, followed by proximal closure of the peritoneum. Inclusion criteria were as follows: male inguinal hernia, either unilateral or bilateral, and age between 6 months and 12 years. Exclusion criteria were as follows: female inguinal hernia, hernia with undescended testicles, recurrent inguinal hernia, and previous major lower abdominal surgery. The main outcome measurement was recurrence, and secondary outcome measurements were operative time, hospital stay, intraoperative complications, postoperative hematoma, postoperative testicular atrophy, and postoperative hydrocele formation.Results There were no significant differences between the two groups as regards age, sex, and mode of presentation. All cases were completed laparoscopically without conversion. Group A showed a significantly higher rate of recurrence as well as hydrocele formation compared with group B; however, there was no difference as regards the operative time, hospital stay, and testicular atrophy.Conclusion Laparoscopic hernia repair using the peritoneal closure following disconnection of the hernia sac is a safe and feasible method for hernial repair with minimal complications. It has a lower recurrence rate compared with the purse–string suturing alone, with no added risk for injury to the vas and vessels
Heavy-Electron Formation and Bipolaronic Transition in the Anharmonic Holstein Model
The emergence of the bipolaronic phase and the formation of the
heavy-electron state in the anharmonic Holstein model are investigated using
the dynamical mean-field theory in combination with the exact diagonalization
method. For a weak anharmonicity, it is confirmed that the first-order
polaron-bipolaron transition occurs from the observation of a discontinuity in
the behavior of several physical quantities. When the anharmonicity is
gradually increased, the polaron-bipolaron transition temperature is reduced as
well as the critical values of the electron-phonon coupling constant for
polaron-bipolaron transition. For a strong anharmonicity, the polaron-bipolaron
transition eventually changes to a crossover behavior. The effect of
anharmonicity on the formation of the heavy-electron state near the
polaron-bipolaron transition and the crossover region is discussed in detail.Comment: 11 pages, 13 figure
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