bluuebunny/crossref_metadata_2025_split huggingface dataset:
Contributions of self-absorption and soot on radiation heat transfer in a laminar methane—air diffusion flame
Authors: Datta A , Saha A 
Published: October 2007

A numerical study is performed to understand the contributions of self-absorption and soot radiation in a laminar methane—air diffusion flame. Simplified models have been adopted for the combustion and soot chemistry. A gray radiation model was developed using the first-order moment method to evaluate the emission and absorption of radiation. The absorption coefficient is determined considering (i) the influence of the gaseous (CH4, CO2, H2O, and CO) species and soot (taken as the benchmark results for the current study), and (ii) only the influence of the gaseous species. A comparison of the two results identifies the contribution of soot on radiation. An optically thin radiation model is also used to estimate the contribution of self-absorption in the flame. Finally, a radiatively adiabatic treatment in the model is employed to account the total effect of radiation. The effects of each contribution have been ascertained by looking at the variation in the radiative heat loss and the resulting temperature distribution of the flame. Differences in the soot volume fraction and thermal NO formation with the different radiative treatments have also been studied. Radiation is found to have very important role on the overall flame structure as well as on the soot formation and NO emission in a methane—air diffusion flame. Neglecting soot in the calculation of radiation underpredicts the radiative heat loss from the flame, particularly in the soot-laden region. Though the effect on the macroscopic flame shape is marginal, the peak temperature difference at the flame tip is found to be substantial. On the contrary, the predictions using the optically thin approximation are very close to the benchmark results.
Parametric simulation of steam injected gas turbine combined cycle
Authors: Srinivas T , Gupta A V S S K S , Reddy B V 
Published: October 2007

In the current work, thermodynamic analysis has been conducted for a steam injected gas turbine (STIG) in the combined cycle system with the dual pressure heat-recovery steam generator. Effect of operating variables such as low-pressure (LP) steam temperature ratio, steam reheat pressure ratio, steam turbine inlet pressure, gas cycle pressure ratio and combustion chamber temperature on the efficiency of the combined cycle has been investigated. Exergy efficiency of the cycle is compared with and without the steam injection with respect to the above-mentioned parameters. Maximum mass ratio of steam injection to fuel has been examined as 6 kg/kg fuel with the complete combustion of the fuel due to excess air supply in the combustion chamber and gas reheater. Results are plotted from the case of without steam injection to the maximum possible steam ratio. LP temperature ratio is identified as a dominant parameter having impact on the efficiency of the combined cycle as the steam is injected at this pressure. Component exergetic losses of the combined cycle as a fraction of exergy of fuel are compared with and without the steam injection. The results showed that the major exergetic loss in the combustion chamber decreased with the steam injection.
Numerical and experimental study of unsteady flow in a centrifugal fan
Authors: Younsi M , Bakir F , Kouidri S , Rey R 
Published: October 2007

In the current work, computational fluid dynamics (CFD) technique coupled with experimental investigations has been used in order to study the complex phenomena related to the unsteady flow in a centrifugal fan. The studied phenomena are the interactions and unsteadiness induced by the rotating blades motion relatively to the volute and their impact on the aeroacoustic behaviour of the fan. Thus, three-dimensional and two-dimensional unsteady simulations have been carried out using unsteady Reynolds averaged Navier-Stokes approach. Turbulence has been modelled with the k-ω-shear stress model and a sliding mesh technique has been applied to the interfaces in order to allow unsteady interactions between the rotating (impeller) and the stationary zones (volute casing). The overall performances predicted by the computations have been validated at different flowrates. In order to locate the flow unsteadiness and perturbations, the near field wall pressure fluctuations at different strategic points on the volute surface have been computed. In addition to this, the unsteady flow variables provided by the CFD calculations have been used as inputs in the Ffowcs Williams-Hawkings equation in order to estimate the tonal noise generated by the centrifugal fan. Finally, the numerical results have been compared with the experimental measurements and a correlation between the wall pressure fluctuations and the far field noise signals has been found.
Pharmaceutical Care in Community Pharmacies: Practice and Research in Peru
Authors: Alvarez-Risco Aldo , Mil JW Foppe van 
Published: October 2007

Objective: To describe the current and possible future development of pharmaceutical care activities and research in healthcare settings in Peru. Findings: Pharmaceutical care has developed slowly in Peru because, until recently, clinical practice never was part of community or hospital pharmacy practice. Some activities of the Ministry of Health, schools of pharmacy, pharmacy organizations, and individual pharmacists, including changes in legislation, are now creating the opportunity to develop pharmaceutical care practice. The implementation of pharmaceutical care in different settings will follow, based on the legislation and experiences of the pharmacists involved. Discussion: The 2004 legislative changes in Peru In the field of drug regulation and the health system create more opportunities for pharmacists to be active in providing care to patients. To stimulate the provision of care, programs of formal training are offered by universities, but more pharmacists need to participate in these courses. As long as pharmacists are absent from their pharmacies (their presence is required by taw), little can be expected. The development of interprofessional collaboration in the Peruvian health system, currently nonexistent, is also important. To improve the performance of the pharmaceutical care system, good relationships between teachers and practitioners must be stimulated. Such links are also essential for developing research into the impact of pharmaceutical care on clinical, economic, and humanistic outcomes of patient care. Conclusions: The pharmaceutical care movement is growing in Peru, The legislation now supports the provision of pharmaceutical care. A number of developments must be stimulated, such as protocol development, appropriate continuing education, different kinds of networking, and remuneration procurement for care provision. When these successfully evolve, pharmaceutical care will become a professional aspect of the work of all pharmacists in Peru.
Effects of Thiazolidinediones on Bone Loss and Fracture
Authors: Murphy Catherine E , Rodgers Philip T 
Published: October 2007

Objective: To examine the evidence regarding the effects of thiazolidinediones on bone loss and fracture. Data Sources: Published studies assessing the effects of thiazolidinediones on bone and/or fracture risk in humans were selected for review. A MEDLINE (1950–April 2007) and International Pharmaceutical Abstracts (1970–April 2007) search was performed. Search terms included thiazolidinediones, rosiglitazone, pioglltazone, troglitazone, bone, bone mineral density, fracture, and osteoporosis. Study Selection and Data Extraction: The literature search retrieved 5 English-language studies evaluating the effects of thiazolidinediones on bone in humans. These consisted of 2 small, uncontrolled studies using troglitazone; 1 prospective, randomized controlled study and 1 retrospective cohort study using rosiglitazone; and a post hoc analysis of an observational cohort study in subjects taking various thiazolidinediones. All of the studies assessed markers of bone metabolism and/or bone mineral density (BMD). No studies were identified that addressed rate of fractures in subjects taking thiazolidinediones. Data Synthesis: The first troglitazone study demonstrated a decrease in levels of bone formation markers (10%; p<0.05) and resorption markers (12%; p<0.01), and authors determined that troglitazone produces a protective effect on bone through decreased bone turnover. The second troglitazone study did not demonstrate a significant change in BMD or levels of bone turnover markers. The 2 rosiglitazone studies demonstrated decreases in BMD of 1.19–1.9% with rosiglitazone use (p<0.05), The post hoc analysis with various thiazolidinediones indicated a 2.5-fold greater decrease in BMD in women reporting thiazolidinedione use. Conclusions: Few studies have assessed the effects of thiazolidinediones on bone in humans. Studies available suggest that treatment with thiazolidinediones, primarily rosiglitazone, contributes to bone loss. The effect appears to be most prominent in postmenopausal women. More studies are needed to better understand the effects of thiazolidinediones on bone and fracture rates.
Manifestations, Diagnosis, and Treatment of Strongyloides stercoralis Infection
Authors: Segarra-Newnham Marisel 
Published: October 2007

Objective: To summarize current literature on the manifestations, diagnosis, and treatment of Strongyloides stercoralis infection. Data Sources: A search was conducted of PubMed (1970–August 2007). Search terms included Strongyloides stercoralis, hyperinfection, prevention, and treatment. Reviews, studies, and recent case reports were included. Additional references were obtained from article bibliographies. Study Selection and Data Extraction: All studies or review articles published in English from 1970 to August 2007 and case reports of hyperinfection or disseminated disease published since 2000 were evaluated. Data Synthesis: Strongyloidiasis is a parasitic infection endemic to tropical, subtropical, and temperate areas including the Appalachian region of the southern US. Prevalence rates vary widely. Patients may present with infection decades after original exposure. Diagnosis can be achieved by identifying the larvae in the stool; usually, more than one sample is needed. Most patients are asymptomatic, However, in immunosuppressed patients, a hyperinfection syndrome or disseminated disease may occur due to the ability of the parasite to reproduce within the host. The most common risk factors for these complications are immunosuppression caused by corticosteroids and infection with human T lymphotropic virus type 1. Treatment options for uncomplicated disease include thiabendazole, ivermectin, and albendazole. Thiabendazole has been replaced by ivermectin as treatment of choice due to better tolerance. These antihelminthics have been used to treat hyperinfection or disseminated disease alone or in combination, but data are limited to case reports or case series. Prevention of disease is mainly achieved by wearing shoes in endemic areas to avoid contact with infected soil. Conclusions: Strongyloides is a unique parasite that can cause a hyperinfection syndrome and disseminated infection several years after exposure. Treatment options include ivermectin, thiabendazole, or albendazole. Information on the best treatment for disseminated disease and hyperinfection is limited.
Oil Spill Dispersants
Authors: Fiocco Robert J. , Lewis Alun 
Published: October 2007

Abstract

Introduction: The purpose of any oil spill response is to minimise the damage that could be caused by the spill. Dispersants are one of the limited number of practical responses that are available to respond to oil spills at sea.
When oil is spilled at sea, a small proportion will be naturally dispersed by the mixing action caused by waves. This process can be slow and proceed to only a limited extent for most situations. Dispersants are used to accelerate the removal of oil from the surface of the sea by greatly enhancing the rate of natural dispersion of oil and thus prevent it from coming ashore. Dispersed oil will also be more rapidly biodegraded by naturally occurring microorganisms. The rationale for dispersant use is that dispersed oil is likely to have less overall environmental impact than oil that persists on the surface of the sea, drifts and eventually contaminates the shoreline.
The development of modern dispersants began after the Torrey Canyon oil spill in 1967. Many lessons have been learned since that spill, and consequently the modern dispersants and application techniques in use today have become an effective way of responding to an oil spill. For example, the dispersant response to the Sea Empress spill in 1996 demonstrated that dispersants can be very effective and prevent a much greater amount of environmental damage from being caused (6).
This chapter describes the chemistry and physics of dispersants, planning and decision-making considerations, and finally their practical application and operational use in oil spill response.
Effectiveness & Environmental Considerations for Countermeasures
Authors: Walker Ann Hayward , Kucklick Janet H. , Michel Jacqueline 
Published: October 2007

Abstract
Mechanical countermeasures for oil spill response have various effectiveness and operational limitations under certain spill situations. This has led to an interest in and use of alternative treatment methods. This chapter reviews the potential utility of one such group, non-dispersant chemical countermeasures, in controlling the adverse impacts from marine oil spills. The types of non-dispersant chemical countermeasures presented here include: herding agents, emulsion treating agents, solidifiers, elasticity modifiers, and shoreline cleaning agents. Each countermeasure group is discussed separately to provide a definition, mechanism of action, and effectiveness and environmental considerations for the group. Where ever possible, examples are given of countermeasure use during an actual spill. In addition to the groups mentioned above, a few other treating agents are briefly described under the section "Miscellaneous Agents" to illustrate other, less prominent types of chemical countermeasures.
Non-dispersant chemical countermeasures appear to have discrete response niches, i.e., situations where the countermeasures are well-suited and offer potential benefits. The key is matching conditions for optimal effectiveness with the appropriate incident-specific characteristics and window of opportunity. The practical aspects of logistics are not addressed because, if their potential utility can be demonstrated, the resolution of these issues would follow.
The Interaction of Fine Particles with Stranded Oil
Authors: Owens Edward H. 
Published: October 2007

Abstract
The interaction of micron-sized mineral particles with stranded oil reduces its adhesion to solid surfaces, such as sediments or bedrock. The net result is the formation of stable, micron-sized, oil droplets that disperse into the water column. In turn, the increase in surface area makes the oil more available for biodegradation. Oil and Fine-particle Interaction ("OFI") can explain how oiled shorelines are cleaned naturally in the absence of wave action in very sheltered coastal environments. Fine-particle interaction can be accelerated during a spill response by relocating the oiled sediments into the surf zone. This has been achieved successfully on two occasions to date: the Tampa Bay response in Florida, and the Sea Empress operation in Wales. Sediment relocation also causes physical abrasion by the hydraulic action of waves so that the processes of fine-particle interaction and surf washing usually occur in combination on open coasts.
Separation of Oil and Water in Oil Spill Recovery Operations
Authors: Gaaseidnes Knut , Turbeville Joseph 
Published: October 2007

Abstract
The separation of water from oil that is collected in any oil spill recovery operation is a continuing and necessary requirement during every stage of the effort. Its importance is reflected in the cost of transport and storage of large volumes of oily water, the salvage value of separated oil and the added labor costs associated with long-term recovery operations.
This paper addresses the effects of weathering and emulsion generation which increase the problems normally associated with water extraction. Separation theory, practical separation technology and recommendations for the future direction of research and development are presented.
Occupational-health Aspects of Marine Oil-spill Response
Authors: Park John M. , Holliday Michael G. 
Published: October 2007

Abstract

Introduction: This chapter addresses chemical aspects of occupational health and marine oil-spill response and is restricted to exposures to crude oil in its various forms. Thus in-situ burning of oil is included, but ancillary chemicals such as surfactants or bioremediation agents are not. The content of this chapter is largely based on the literature published after 1985, the date of a comprehensive review conducted by Politzer et al. [1985] for the American Petroleum Institute, and on a review carried out for the Marine Spill Response Corporation early in 1993 [Holliday and Park, 1993].
Concern about health and safety is a normal part of every oil spill. In general, safety is easier to understand and address than are concerns about exposure to crude oil and other chemicals which might be used in the response. At one level, human exposure can be addressed through the enforcement of very conservative requirements for the use of personal protective equipment (PPE). In the real world, however, conditions at a spill site make the use of such equipment inconvenient or even hazardous, and so the goal becomes to balance the risk from exposure with the appropriate level of PPE.
While oil-spill cleanup is a comparatively new aspect of occupational-health practice, and dates from the formalization of response measures by companies and national and international agencies (something that occurred over the last 30 years), exposure to crude oil itself is a "mature" occupational-health matter. Workers have been exposed, both by inhalation and dermally, to the effects of crude oil for the past century. The exposure of response workers during the early phases of the oil-spill response can be likened to that experienced by oil-well-drilling crews and, to a lesser extent, by oil-well-maintenance personnel or fighters of oil-well fires. In contrast, exposures in the later stages of the cleanup are less clearly related to occupations within the oil industry. The crude oil will have been altered by weathering, and exposure to cleanup chemicals (e.g., dispersants, bioremediation agents) will become relatively more prominent. Such substances are beyond the scope of this chapter, and in any event, few data are available on the compositions or mammalian toxicity of dispersants. Although there are frequent references to toxicity in connection with dispersants, these invariably seem to refer to ecotoxicity. Human hazard does not appear to be an issue. For example, in a recently published paper entitled, "Effectiveness and safety of biosurfactants as agents of oil spill response" [Lepo et al., 1997], "safety" refers to possible toxicity to crustaceans and fish.
Ecological Effectiveness of Oil Spill Countermeasures: How Clean is Clean?
Authors: Baker Jenifer M. 
Published: October 2007

Abstract

Introduction: In the aftermath of an oil spill, what should drive the cleanup response and when is it reasonable to stop cleaning? Further, which of the diversity of oil spill clean-up technologies as described in other chapters of this volume might be employed most effectively to achieve this elusive goal? These are complex questions involving chemical, ecological, socio-economic and political considerations and there are no simple answers. It is important to identify and build consensus for recommended clean-up protocols. These recommendations should be based on the considerable experience that has accumulated over the past 30 years. It is the intent of this paper to identify key points and issues with respect to ecological aspects, bearing in mind that these in turn commonly relate to socio-economic aspects.
The Use of Mesocosms in Marine Oil Spill Ecological Research and Development
Authors: Reilly Timothy J. 
Published: October 2007

Abstract

Introduction: The use of chemical and biological agents (e.g. dispersants and bioremediation agents, respectively), as well as certain physical oil removal techniques (e.g. high-pressure, hot-water applications to oiled shorelines) during oil spill response operations requires consideration both of the gross effectiveness of such oil removal/displacement techniques and of the ecological impact of the response technique. Accordingly, the intent of response technology optimization requires the identification of suitable response agents, their application strategies, determination of mass oil removal effectiveness, and efficient coordination of alternative response strategies with conventional measures, all compared with traditional mechanical collection methods and evaluation or relative response ecological impacts. These issues often need to be examined in an experimental setting in order to acquire information required to make more effective decisions during oil spill response and cleanup operations. Controlled field studies that are designed to identify optimal response and clean-up strategies, while valuable for realism, are expensive and often difficult to implement because of regulatory barriers (Reilly et al., 1994)). Conversely, results from small scale laboratory testing do not incorporate sufficient environmental realism (variables and scale) to permit confident predictions about real-world situations. However, bounded and partly enclosed outdoor experimental units, or 'mesocosms', can closely simulate natural aquatic environments (Odum, 1984). Such test systems provide a simulation of real-world exposure without the costs of a controlled-release field study. Mesocosms can serve to bridge the gap between large-scale field experiments, with their inherent control difficulties, laboratory experiments which can be statistically replicated but suffer from a lack of environmental realism (Rodgers et al., 1996).
Mesocosms have strengths and weaknesses depending upon system design. Therefore, the type of ecological research to be conducted will dictate the choice of mesocosm design. The following discussion presents design requirements and scientific considerations for mesocosm simulations of marine environments impacted by oil spills. Two existing mesocosm systems for marine oil spill ecological research in both pelagic and nearshore environments are reviewed in some detail - the Marine Ecosystem Research Laboratory (MERL) in Narragansett, Rhode Island, and the Coastal Oil-Spill Simulation System (COSS), in Corpus Christi, Texas.
Bioremediation of Oil on Shoreline Environments: Development of Techniques and Guidelines
Authors: Lee Kenneth , Merlin Xavier 
Published: October 2007

Abstract
Over the last 20 years, the development of operational procedures to accelerate the natural biodegradation rates of oil spilled on shoreline environments has been the focus of numerous research programs. As a result, bioremediation has been demonstrated to be an effective oil spill countermeasure for use in cobble, sand beach, salt marsh, and mudflat environments. Today, studies are directed towards improving the efficacy and evaluating the ecological impacts of available bioremediation agents and/or procedures. This review describes the latest developments in bioremediation strategies and their key success factors.