The solid-solid separation processes employed by modern coal preparation plants require large amounts of process water that must be removed from the surfaces of particles using mechanical dewatering equipment. Unfortunately, the existing processes that are used to dewater fine particles are inefficient in terms of moisture reduction and/or solids recovery. Many coal preparation plants are forced to discard fine coal particles because of the inability of existing technologies to reduce the moisture content of this product to an acceptable level. In light of this problem, a new ultrafine dewatering process called hyperbaric filter centrifugation (HFC) has been developed. This novel method combines centrifugation and pressure filtration within a single process to substantially reduce moistures over what can be achieved using conventional dewatering systems. In the current study, steady-state and dynamic dewatering models were developed in order to be able to simulate the behavior of the HFC technology. The steady-state model, which was based on grain-size properties, used empirical expressions to predict product moistures. On the other hand, the dynamic model was based on fundamental theories of filtration and centrifugation. Although the dynamic model provided a better understanding of the working principles of the process, the steady-state grain model produced more accurate equilibrium moisture predictions. Therefore, the steady-state model was used to further investigate the effects of several parameters on cake moistures. As such, the steady-state model was useful for scale up and design purposes. The steady-state dewatering model was also used to perform an economical analysis of potential applications of the HFC technology. The model was used to investigate a variety of new circuit designs that have the potential to be commercially applied in the coal industry. The results clearly showed that this new technology would allow coal companies to process difficult-to-dewater ultrafines using the HFC process, while coarser solids would be more appropriately dewatered using conventional technologies such as vacuum filters or screenbowl centrifuges. This "split dewatering" concept would provide substantially higher profitability due to lower moistures and higher recoveries of ultrafine solids than could be achieved using a single dewatering process. Laboratory- and pilot-scale versions of this technology has been constructed and tested at the facilities of Mining & Minerals Engineering Department of Virginia Tech. Results of this testing program showed that 30-50% lower moisture values than the ones obtained using conventional mechanical dewatering processes could be achieved with the HFC technology. Based on these promising results, a pilot-scale prototype unit, which was tested successfully at several commercial U.S. coal plants, was also constructed by Decanter Machine, Inc. Finally, the process of developing of this novel technology was successfully completed with the sale of the first full-scale commercial unit by Decanter Machine, Inc. to a major U.S. coal producer. / Ph. D.

No description available.

No description available.

Thesis (doctoral)--Lund University, 1995. / Added t.p. with thesis statement inserted.

Thesis (doctoral)--Lund University, 1995. / Added t.p. with thesis statement inserted.

At present, the Eastern Cape is the only province in South Africa lacking a clinical hospital-based hyperbaric facility. East Cape Hyperbaric, to be situated at Greenacres Hospital in the Nelson Mandela Metropolitan, will offer the Eastern Cape community access to a world-class facility that will offer their patients Hyperbaric Oxygen Therapy and a Wound-Healing Facility. The objective of this study was to assess the viability of establishing a Hyperbaric Oxygen Therapy (HBOT) facility for the Nelson Mandela Metropolitan Municipality (NMMM), using sound business planning principles. A business plan precisely defines the business, identifies the goals, and serves as the firm's resume. A business plan will assist in allocating resources effectively, handle unforeseen complications, and assist in making sound business decisions. Because it provides specific and organized information about the company and how the company will repay borrowed money, a good business plan is a crucial part of business planning. In order to quantify the demand for a Hyperbaric Oxygen Therapy facility, a questionnaire was designed, in such a manner as to identify the current demand for a HBOT facility. The questionnaires were distributed to all medical practitioners within the NMMM by means of fax, e-mail and hand-delivery. Research conducted indicates that the results are promising enough to warrant the expedient creation of this business facility.

No description available.

Despite lack of scientific evidence, hyperbaric oxygen therapy (HBO2) has been used as a treatment for children with cerebral palsy (CP). Recently, a multi-centre randomised, double-blind, placebo-controlled trial assessed the efficacy of HBO2 therapy for children with CP. Using the same cohort, the purpose of this study was to examine the effectiveness of HBO2 therapy on hand function using the Jebsen-Taylor test. All children received 40 treatments over a 2-month period. HBO2 treatments were 60 minutes with 100% O2 at 1.75 atmospheres absolute (ATA). Placebo treatments were also 60 minutes with air (21% O2) at 1.3 ATA. Seventy-eight children with CP, aged 3--12 years completed pre and post hand function assessments. Hand function was evaluated using one quantitative measure (time) and three qualitative measures. There were no significant changes between baseline and follow-up tests for any of the measures, although both experimental and control groups improved ( p = 0.08) their total times for the Jebsen test. The HBO2 group improved by 54.5 seconds (8.8%) while the placebo group improved by 47.8 seconds (7.7%). The results indicate that HBO2 therapy did not enhance the hand function of children with CP.

The purpose of this study was to examine the effects of HBO2 therapy on exercise-induced muscle damage. Subjects (n = 16 university student volunteers) were randomly divided into an experimental group that received HBO2 therapy and a control group that did not receive any treatments. HBO2 treatments consisted of 5 sessions of breathing 95% oxygen at 2.5 atm abs for 100 min. Temporary muscle soreness was created using a single-leg eccentric exercise task involving the quadriceps femoris. Over the next 14 days, measurements were obtained on muscle soreness, leg circumference, quadriceps peak torque, quadriceps average power, fatigue and plasma creative kinase. After eccentric exercise, plasma CK levels and perceived muscle soreness were elevated but were not different between HBO2 and control groups. HBO2 therapy did not alter leg circumference, quadriceps peak torque, average power or fatigue compared to the control group. The data indicated that five HBO2 treatments did not speed recovery following eccentric exercise that induced temporary muscle damage.

Purpose. The purpose was to examine venous PO2, transcutaneous tissue PO2 (PtcO 2), and VO2max in a normobaric environment following a single HBO2 treatment. Methods. Ten moderately trained (VO2max = 57.6 mL&middot;kg-1&middot;min -1) males volunteered for the study. Baseline testing included measures of VO2max, PtcO2, and anthropometry. Subjects received two HBO2 treatments, which consisted of breathing 95% oxygen at 2.5 ATA for 90 min. Following the first HBO2 treatment (6.0 +/- 1.0 min), subjects performed a VO2max test. Following the second HBO2 treatment, leg and chest PtcO2 and venous PO2 were monitored for 60 min. Results . VO2max, running time, and peak La were not altered (p < 0.05) post-HBO2 treatment. Leg PtcO2 was lower (p < 0.05) and chest PtcO2 was unchanged following the HBO2 treatment compared to baseline values. Venous PO2 was lower in the first 3 min post-HBO2 treatment than subsequent values, but no other differences were found (p < 0.05). Conclusion. The results of this study show that a single HBO 2 treatment at 2.5 ATA for 90 min does not elevate venous PO2, PtcO2, or VO2max in a normobaric, normoxic environment.