Biomedical subjects

Raymond L Smith

Publications and source records attributed to Raymond L Smith.

3 recordsLinked to original sources

PubMed2006

Treatment of osteochondral lesions of the talus with cryopreserved talar allograft and ankle distraction with external fixation.

This article presents the results of a retrospective review of six osteochondral lesions on six patients (five men and one woman) treated with transplantation of cryopreserved talar allograft and ankle joint distraction. All patients complained of ankle pain existing for a long time secondary to a traumatic episode confirmed through MRI. Lesions ranged in measurement from 0.8 cm x 0.8 cm to 3.2 cm x 1.8 cm with an average size of 2.1 cm x 1.5 cm. Each patient underwent talar dome transplantation using fresh frozen talar allograft followed by ankle distraction. Distraction was obtained using a three-ring multiplanar external fixation device. All surgeries were performed between 2002 and 2004. All external fixators were removed at 8 weeks and patients remained partial-weight bearing in a removable cast boot for an additional 8 weeks. Serial postoperative radiographs showed complete consolidation of the allograft within 16 weeks. The average follow up time was 24 months, and all patients related a subjective decrease in symptoms and increase in activity levels. Patients were also evaluated utilizing the Maryland Foot Score both pre- and postoperatively. Preoperatively, four patients were graded as fair and two were graded as poor. Postoperatively, two patients related excellent results, three patients related good results, and one patient related fair results. Several patients experienced minor complications such as pin site irritation (five patients), painful talar wire (one patient), and periostitis (one patient). No patients experienced any major complications and none have required additional surgery. We feel that these initial results warrant further investigation of this treatment.

Adult↗

PubMed2005

Systematic procedure for designing processes with multiple environmental objectives.

Evaluation of multiple objectives is very important in designing environmentally benign processes. It requires a systematic procedure for solving multiobjective decision-making problems due to the complex nature of the problems, the need for complex assessments, and the complicated analysis of multidimensional results. In this paper, a novel systematic procedure is presented for designing processes with multiple environmental objectives. This procedure has four steps: initialization, screening, evaluation, and visualization. The first two steps are used for systematic problem formulation based on mass and energy estimation and order of magnitude analysis. In the third step, an efficient parallel multiobjective steady-state genetic algorithm is applied to design environmentally benign and economically viable processes and to provide more accurate and uniform Pareto optimal solutions. In the last step a new visualization technique for illustrating multiple objectives and their design parameters on the same diagram is developed. Through these integrated steps the decision-maker can easily determine design alternatives with respect to his or her preferences. Most importantly, this technique is independent of the number of objectives and design parameters. As a case study, acetic acid recovery from aqueous waste mixtures is investigated by minimizing eight potential environmental impacts and maximizing total profit. After applying the systematic procedure, the most preferred design alternatives and their design parameters are easily identified.

Algorithms↗

PubMed2003

Life cycle assessment of gasoline blending options.

A life cycle assessment has been done to compare the potential environmental impacts of various gasoline blends that meet octane and vapor pressure specifications. The main blending components of alkylate, cracked gasoline, and reformate have different octane and vapor pressure values as well as different potential environmental impacts. Because the octane and vapor pressure values are nonlinearly related to impacts, the results of this study show that some blends are better for the environment than others. To determine blending component compositions, simulations of a reformer were done at various operating conditions. The reformate products of these simulations had a wide range of octane values and potential environmental impacts. Results of the study indicate that for low-octane gasoline (95 Research Octane Number), lower reformer temperatures and pressures generally decrease the potential environmental impacts. However, different results are obtained for high-octane gasoline (98 RON), where increasing reformer temperatures and pressures increase the reformate octane values faster than the potential environmental impacts. The higher octane values for reformate allow blends to have less reformate, and therefore high-octane gasoline can have lower potential environmental impacts when the reformer is operated at higher temperatures and pressures. In the blends studied, reformate and cracked gasoline have the highest total impacts, of which photochemical ozone creation is the largest contributor (assuming all impact categories are equally weighted). Alkylate has a much lower total potential environmental impact but does have higher impact values for human toxicity by ingestion, aquatic toxicity, terrestrial toxicity, and acidification. Therefore, depending on environmental priorities, different gasoline blends and operating conditions should be chosen to meet octane and vapor pressure specifications.

Gasoline↗