Use of Green's functions in the numerical solution of two-point boundary value problems Final report, 1 Apr. 1970 - 31 Mar. 1971

Green function in solving linear and nonlinear second order ordinary differential equations including examples in finding rendezvous and periodic orbits of restricted three body syste

Geology and mining history of two proposed reclamation sites of the Wilds, Muskingum County, Ohio

Abandoned strip-mined lands in Ohio are being reclaimed under state and federal regulations. The abandoned lands are required to be returned to the same or better condition than before mining. Many reclaimed areas, including the Wilds, are being returned to productive uses that consist of recreation areas, wildlife areas, golf courses, and pastures. Two sites at the Wilds in Muskingum County, Ohio were chosen for this study. Neither site was suitably reclaimed using lime fertilizer. The proposed reclamation project at the Wilds is to examine the effectiveness of N-Viro Soil, a bio-organic aglime topsoil, on the two sites. The N-Viro Soil is expected to adjust the pH of the soil, increase nutrients, and add organics. Although the project was designed for continuing research, the information gathered from previous projects suggests that predictions can be made about the effectiveness of the N-Viro Soil on the current two sites.No embarg

Aerodynamic characteristics of GD B-15B booster during cruise and landing M equals 0.2

Aerodynamic characteristics of scale model of space shuttle booster at cruise and landing speed of Mach 0.

Space shuttle: Low speed cruise, takeoff and landing aerodynamic characteristics, including engine exhaust effects of the GD/C B-15B booster

Low speed wind tunnel tests of takeoff, landing, and cruise aerodynamic characteristics of space shuttle booster with exhaust effect simulatio

Pediatric intestinal obstruction in Malawi: characteristics and outcomes

Abstract Background Intestinal obstruction (IO) is a common pediatric surgical emergency in sub-Saharan Africa with high morbidity and mortality, but little is known about its etiopathogenesis in Malawi. Methods Retrospective analysis of patients seen from February 2012 to June 2014 at Kamuzu Central Hospital in Lilongwe, Malawi (n = 3,407). Pediatric patients with IO were analyzed (n = 130). Results Overall, 57% of patients were male with a mean age of 3.5 ± 4.1 years. A total of 52% of patients underwent operative intervention. The overall mortality rate was 3%. Leading causes of IO were Hirschprung's 29%, anorectal malformation 18%, and intussusception 4%. Neonates and patients with congenital causes of IO underwent surgery less frequently than infants and/or children and patients with acquired causes, respectively. These groups also demonstrated increased number of days from admission to surgery. Conclusions Increasing pediatric-specific surgical education and/or training and expanding access to resources may improve mortality after IO in poor medical communities within sub-Saharan Africa

Microwave Reflection and Dielectric Properties of Mortar Subjected to Compression Force and Cyclically Exposed to Water and Sodium Chloride Solution

Corrosion of the reinforcing steel is a major cause of damage and deterioration in reinforced concrete structures such as concrete bridge decks and columns. Chloride intrusion into concrete can lead to depassivation of the steel and initiation of corrosion. Thus, it is very important to be able to nondestructively detect and evaluate the free chloride content in concrete. Near-field microwave nondestructive testing techniques, using open-ended rectangular waveguide probes, have shown great potential for evaluating various properties of concrete, including the successful detection of sodium chloride added to mortar mixing water. In this study, several mortar samples are cyclically soaked in distilled and salt water while also experiencing compression force. Compression force, simulating in-service loading, causes microcracking, which results in increased microcracking and permeability, promoting chloride ingress. The daily microwave reflection and dielectric properties of these samples were measured at 3 GHz. The results show the capability of these microwave measurements for detecting the increased level of chloride permeation and loading as a function of the increasing number of soaking cycles. The influence of salt ingress is shown to be more prominent in the loss factor, while the effect of loading is more evident in the permittivity of the samples

Sub-Saharan African hospitals have a unique opportunity to address intentional injury to children

Intentional injury to children is a major, but neglected public health and human rights issue with devastating consequences on families and societies, particularly in low and middle income countries (LMICs). Intentional injury is defined by the World Health Organization as ‘‘the intentional use of physical force or power, threatened or actual, against oneself, another person, or against a group or community that either results in or has a high likelihood of resulting in injury, death, psychological harm, maldevelopment or deprivation.

Variations in injury characteristics among paediatric patients following trauma: A retrospective descriptive analysis comparing pre-hospital and in-hospital deaths at Kamuzu Central Hospital, Lilongwe, Malawi

Background: Trauma is a major cause of paediatric mortality in sub-Saharan Africa. In absence of pre-hospital care, the injury mechanism and cause of death is difficult to characterise. Injury characteristics of pre-hospital deaths (PHD) versus in-hospital deaths (IHD) were compared.Methods: Using our trauma surveillance database, a retrospective, descriptive analysis of children (<18 years) presenting to Kamuzu Central Hospital in Lilongwe, Malawi from 2008 to 2013 was performed. Patient and injury characteristics of pre-hospital and in-hospital deaths were compared with univariate and bivariate analysis.Results: Of 30,462 paediatric trauma patients presenting between 2008 and 2013, 170 and 173 were PHD and IHD, respectively. In PHD and IHD patients mean age was 7.3±4.9 v 5.2±4.3 (p<0.001), respectively. IHD patients were more likely transported via ambulance than those PHD, 51.2% v 8.3% (p<0.001). The primary mechanisms of injury for PHD were road traffic injuries (RTI) (45.8%) and drowning (22.0%), with head injury (46.7%) being the predominant cause of death. Burns were the leading mechanism of injury (61.8%) and cause of death (61.9%) in IHD, with a mean total body surface area involvement of 24.7±16.0%.Conclusions: RTI remains Malawi’s major driver of paediatric mortality. A majority of these deaths attributed to head injury occur prior to hospitalisation; therefore the mortality burden is underestimated if accounting for IHD alone. Death in burn patients is likely due to under-resuscitation or sepsis. Improving pre-hospital care and head injury and burn management can improve injury related paediatric mortality

Multiple Peer Group Self-identification and Adolescent Tobacco Use

Associations between peer group self-identification and smoking were examined among 2,698 ethnically diverse middle school students in Los Angeles who self-identified with groups such as Rockers, Skaters, and Gamers. The sample was 47.1% male, 54.7% Latino, 25.4% Asian, 10.8% White, 9.1% Other ethnicity, and 59.3% children of immigrant parents. Multiple group self identification was common: 84% identified with two or more groups and 65% identified with three or more groups. Logistic regression analyses indicated that as students endorsed more high risk groups, the greater their risk of tobacco use. A classification tree analysis identified risk groups based on interactions among ethnicity, gender, and group self-identification. Psychographic targeting based on group self-identification could be useful to design more relevant smoking prevention messages for adolescents who identify with high-risk peer groups