bluuebunny/crossref_metadata_2025 huggingface dataset:
Adrenal steroid hormone concentrations in dogs with hair cycle arrest (Alopecia X) before and during treatment with melatonin and mitotane
Authors: FRANK LINDA A. , HNILICA KEITH A. , OLIVER JACK W.
Published: October 2004

Abstract The purpose of the study was to evaluate intermediate adrenal steroid hormones (ISH) in neutered dogs with hair cycle arrest (Alopecia X) during treatment with melatonin, and to see if hair re‐growth is associated with sex hormone concentrations within the normal ranges. Twenty‐nine neutered, euthyroid, and normo‐cortisolemic dogs were enrolled in the study (23 Pomeranians, three keeshonds, two miniature poodles, and one Siberian husky). Coat assessment and an ACTH stimulation test were performed pre‐treatment and approximately every 4 months for a year post treatment. Melatonin was administered initially at 3–6 mg, every 12 h. Based on clinical progression, each dog was continued on the current dose of melatonin, given an increased dose of melatonin or changed to mitotane. Partial to complete hair re‐growth occurred in 14/23 Pomeranians, and partial re‐growth in 3/3 keeshond and 1/2 poodle dogs. A Siberian husky dog failed to re‐grow hair. Fifteen dogs had partial hair re‐growth at the first re‐evaluation. Melatonin dosage was increased in eight dogs but only one had improved hair re‐growth. On mitotane treatment, partial to complete hair re‐growth was seen in 4/6 dogs and no re‐growth in 2/6 dogs. No significant decrease in sex hormone concentrations were seen during melatonin or mitotane treatment. Concentrations of ISH in dogs with hair re‐growth did not differ significantly from pre‐treatment values. At the completion of the study, androstenedione, progesterone and 17‐hydroxyprogesterone were still above reference ranges in 21, 64 and 36%, respectively, of dogs with partial to complete hair re‐growth. In conclusion, 62% of dogs had partial to complete hair re‐growth. However, not all dogs with hair re‐growth had concentrations of ISH within the normal range.
Investigation on the clinical efficacy and safety of 0.1% tacrolimus ointment (Protopic®) in canine atopic dermatitis: a randomized, double‐blinded, placebo‐controlled, cross‐over study
Authors: MARSELLA R. , NICKLIN C. F. , SAGLIO S. , LOPEZ J.
Published: October 2004

Abstract  Topical tacrolimus is successfully used in people with atopic dermatitis. Preliminary studies in dogs with atopic dermatitis using tacrolimus in a compounded lotion formulation indicated that tacrolimus significantly decreased erythema and pruritus according to investigator, but no significant improvement was reported by the dog owners. The objectives of this study were to evaluate the clinical efficacy and safety of the commercially available 0.1% tacrolimus ointment (Protopic®) in dogs with atopic dermatitis. The study was designed as a double‐blinded, placebo‐controlled, cross‐over study. Selected dogs were allocated to either tacrolimus or placebo for 4 weeks. After 4 weeks there was a wash‐out period of 2 weeks and treatments were switched. Twelve dogs completed the study. Clinical signs were scored. Blood samples were collected for complete blood count, chemistry panels and tacrolimus levels at week 0 and 4 of each treatment. Tacrolimus ointment significantly decreased severity of symptoms for both owners and investigators at the end of the trial. When the same dogs received the placebo, there were no differences between week 0 and week 4 scores. Dogs with localized disease responded better than dogs with generalized disease. Tacrolimus was detected in the blood of animals receiving the active ingredient. Levels were below the level of toxicity and no adverse effects were reported in any of the dogs. No changes in complete blood count and chemistry parameters were detected between groups or within groups. In conclusion, tacrolimus appears to be a safe alternative treatment in dogs with atopic dermatitis, especially in those with localized disease.
Clinical and genetic aspects of X‐linked ectodermal dysplasia in the dog – a review including three new spontaneous cases
Authors: MOURA ENIO , CIRIO SILVANA M.
Published: October 2004

Abstract  This review presents the clinical, dermato‐histopathological and genetic features of canine X‐linked ectodermal dysplasia in previously reported cases and in three new spontaneous cases. The condition is compared with anhidrotic ectodermal dysplasia in humans and, based on current genetic concepts, we suggest that the two conditions are caused by the same gene and, consequently, represent a single pathological entity that affects both humans and dogs.
Frequency doubling perimetry screening mode compared to the full‐threshold mode
Authors: Stoutenbeek Remco , Heeg Govert P. , Jansonius Nomdo M.
Published: October 2004

The diagnostic performance of the frequency doubling perimetry (FDT) C20‐1 screening mode was compared to that of the C20 full‐threshold mode. For the number of defects p < 1% in the total deviation plot, both modes appeared to perform similarly in terms of sensitivity, specificity, and area under the receiver–operating characteristic (ROC) curve. Different cut‐off points should be applied for both modes to obtain equal sensitivity and specificity values, and – related to that – for most subjects more defects were found in full‐threshold mode than in screening mode. For the screening mode, we found a sensitivity of 0.91 and a specificity of 0.88 at a cut‐off point of >0 defects, and an area under the ROC curve of 0.93.
An evaluation of algorithms designed to classify the results from frequency doubling perimetry
Authors: Müskens Rogier P. H. M. , Heeg Govert P. , Jansonius Nomdo M.
Published: October 2004

All previously published algorithms for the interpretation of frequency doubling perimetry test results were compared in full‐threshold mode in a large group of glaucoma patients (n = 452) and normal subjects (n = 237). Areas under the receiver–operating characteristic (ROC) curve ranged from 0.86 to 0.92. None of the algorithms performed substantially better than simply counting the number of defects p < 1% in the total deviation plot. For this algorithm, we found a sensitivity of 0.90 and a specificity of 0.81 at a cut‐off point of >1 defect, and an area under the ROC curve of 0.92.
Non‐compliance with lens care and maintenance in diabetic contact lens wearers
Authors: O'Donnell Clare , Efron Nathan
Published: October 2004

We hypothesize that diabetic contact lens wearers may represent a special group displaying higher levels of compliance with their lens care regimens as a result of learned behaviour relating to maintenance of their diabetic condition. To test this hypothesis, a prospective, single centre, controlled, masked study was performed whereby 29 diabetic contact lens patients and 29 non‐diabetic control subjects were issued with disposable hydrogel contact lenses and a multipurpose lens care regimen. All participants were given identical instruction on lens care and maintenance. Compliance levels were assessed at a 12‐month aftercare appointment by demonstration and questionnaire. Twenty‐four different aspects of compliance were scored, 12 by observation and 12 by questionnaire report, of which only two showed a significant difference between the diabetic and control groups. Although the combined population of contact lens wearers was generally compliant, there were examples of non‐compliance in both groups. Neither the duration of diabetes nor the degree of metabolic control appeared to have a significant effect on compliance. The results suggest that eye care practitioners cannot assume that diabetic patients will be more compliant with contact lens care and maintenance than non‐diabetic patients.
Statistical normal values of visual parameters that characterize binocular function in children
Authors: Jiménez R. , Pérez M. A. , García J. A. , González M. D.
Published: October 2004

A wide range of visual parameters used to evaluate binocular function were evaluated in a paediatric population (1056 subjects aged 6–12 years). Mean values are provided for these ages in optometric tests that directly assess the vergence system, horizontal phorias for near and far vision (measured by a modified version of the Thorington method), negative and positive vergence amplitude for near and far vision (step vergence testing), vergence facility (flippers 8 Δ BI/8 Δ BO), and near‐point of convergence (penlight push‐up technique and red‐lens push‐up technique), as well as stimulus accommodative convergence/accommodation ratio and stereoacuity (Randot test) which provide an overall evaluation of the vergence, accommodative and oculomotor systems. A statistical comparison (anova and Bonferroni post hoc test) of these values between ages was performed. The differences, although statistically significant, were not clinically meaningful, and therefore we identified two trends in the behaviour of these parameters. For all parameters, except for vergence facility, we established a single mean reference value for the age range studied. The difference between the means for vergence facility indicated the need to divide the population into two age ranges (6–8 and 8–12 years). This study establishes statistical normal values for these parameters in a paediatric population and their means are a valuable instrument for separating children with binocular anomalies from those with normal binocular vision.
Relation between injected volume and optical parameters in refilled isolated porcine lenses
Authors: Koopmans Steven A. , Terwee Thom , Haitjema Henk J. , Deuring Henk , van Aarle Sonja , Kooijman Aart C.
Published: October 2004

Purpose:  This study was performed to elucidate the correlation between added lens refill material and enhanced lens power as well as the correlation between lens refilling volume and accommodative amplitude as determined by equatorial stretching of ex vivo refilled pigs’ lenses.

Methods:  Nine porcine lenses were refilled with increasing amounts of silicone oil. After each refill step, the lens power, the lens power change, and the lens thickness were measured both in the relaxed state and with a 3‐mm larger ciliary body diameter. In addition, the spherical aberration of the refilled lenses was also quantified.

Results:  Injection of 0.04 mL silicone material into the relaxed lens enhanced the lens power by 1 D. A 0.54‐mm increase of the lens thickness in relaxed lenses added 1 D to the lens power. Increasing the lens refilling volume decreased the lens power changes measured at 3‐mm ciliary body stretch. Spherical aberration was positive in the refilled lenses and increased with increasing lens refilling volume.

Conclusion:  The correlation found between the refilling volume and the lens power (0.04 mL D−1), as well as the correlation between the lens thickness and the lens power (0.54 mm D−1), might be important factors to be controlled in conjunction with surgery, as these also determine the lens power in the presence of this refill material. An increasing lens filling volume is associated with decreasing accommodative amplitude. The positive spherical aberration of refilled porcine lenses presents a sharp contrast to the negative aberration of natural pigs’ lenses. Different lens contours and the transition from a gradient to a homogeneous refractive index might be responsible for this change in spherical aberration.
School vision screening, ages 5–16 years: the evidence‐base for content, provision and efficacy
Authors: Logan Nicola S. , Gilmartin Bernard
Published: October 2004

The optometric profession in the UK has a major role in the detection, assessment and management of ocular anomalies in children between 5 and 16 years of age. The role complements a variety of associated screening services provided across several health care sectors. The review examines the evidence‐base for the content, provision and efficacy of these screening services in terms of the prevalence of anomalies such as refractive error, amblyopia, binocular vision and colour vision and considers the consequences of their curtailment. Vision screening must focus on pre‐school children if the aim of the screening is to detect and treat conditions that may lead to amblyopia, whereas if the aim is to detect and correct significant refractive errors (not likely to lead to amblyopia) then it would be expedient for the optometric profession to act as the major provider of refractive (and colour vision) screening at 5–6 years of age. Myopia is the refractive error most likely to develop during primary school presenting typically between 8 and 12 years of age, thus screening at entry to secondary school is warranted. Given the inevitable restriction on resources for health care, establishing screening at 5 and 11 years of age, with exclusion of any subsequent screening, is the preferred option.
PRICE AND QUANTITY QUOTES ON NASDAQ: A STUDY OF DEALER QUOTATION BEHAVIOR
Authors: Chung Kee H. , Zhao Xin
Published: October 2004

We show that the majority of quotes posted by NASDAQ dealers are noncompetitive and only 19.5% (18.4%) of bid (ask) quotes are at the inside. The percentage of dealer quotes that are at the inside is higher for stocks with wider spreads, fewer market makers, and more frequent trading, and lower for stocks with larger trade sizes and higher return volatility. These results support our conjecture that dealers have greater incentives to be at the inside for stocks with larger market‐making revenues and smaller costs. Dealers post large depths when their quotes are at the inside and frequently quote the minimum required depth when they are not at the inside. The latter quotation behavior leads to the negative intertemporal correlation between dealer spread and depth.
Setting Riparian/Aquatic Restoration Objectives within a Watershed Context
Authors: Kershner Jeffrey L.
Published: October 2004

Declines in native plant and animal communities have prompted new interest in the restoration of aquatic and riparian ecosystems. Past restoration activities typically have been site specific, with little thought to processes operating at larger scales. A watershed analysis process developed in the Pacific Northwest identifies four operating scales useful in developing restoration priorities: region, basin, watershed, and specific site. Watershed analysis provides a template for restoration practitioners to use in prioritizing restoration activities. The template identifies seven key steps necessary to understand and develop restoration priorities: (1) characterization, (2) identification of key issues and questions, (3) documentation of current conditions, (4) description of reference conditions, (5) identification of objectives, (6) summary of conditions and determination of causes, and (7) recommendations. When a similar process was used in the Uinta Mountains, Utah, and in the Siuslaw National Forest, Oregon, specialists were able to identify key habitat conditions and habitat forming processes and then to establish restoration priorities and implement the appropriate activities. Watershed analysis provides a valuable set of tools for identifying restoration activities and is currently being used throughout the Pacific Northwest to develop management strategies and restoration priorities. Although the analysis requires significant time, money, and personnel, experience suggests that watershed analysis provides valuable direction for managing aquatic and riparian resources.
Applying a Two‐Stage System to Prioritize Riparian Restoration at the San Luis Rey River, San Diego County, California
Authors: Olson Craig , Harris Richard
Published: October 2004

A two‐stage system for selecting stream reaches and riparian communities for restoration was applied to the 80‐km San Luis Rey River below the Lake Henshaw dam in southern California. In the first stage, data from topographic quadrangles and aerial photographs were analyzed to define and classify reaches. These analyses concluded that (1) 28 km of the river and adjacent floodplain were suitable for second‐stage evaluation of restoration needs and (2) 32 km met criteria for reference conditions at the stream reach scale and should be protected from further impacts. The remaining 20 km of the river and flood‐plain were considered unsuitable for restoration to reach‐scale reference conditions; individual sites may be restored under existing regulatory review. Second‐stage field sampling provided data on vegetation and floodplain landforms and substrate from more than 3000 plots within the 28 km of river and 1120 ha of floodplain selected for further study. Classification of floristic samples stratified by landform/substrate class indicated six primary riparian communities on the floodplain, some associated with particular flood‐plain landform/substrate classes and others ubiquitous. Reference conditions for these communities were interpreted from the data. There were two major departures from reference conditions: tree‐dominated communities were less extensive than historic levels and exotic plants had significantly invaded some landforms and communities, displacing natural communities. General goals would include restoration of tree communities and removal of exotics, with further consideration of site‐specific objectives. The results included estimates of the areas by community type requiring restoration. The approach was developed for streams in the semi‐arid western United States, but it may be adapted for use elsewhere.
The Role of GIS in Selecting Sites for Riparian Restoration Based on Hydrology and Land Use
Authors: Russell Gordon D. , Hawkins Charles P. , O'Neill Michael P.
Published: October 2004

Successful long‐term wetland restoration efforts require consideration of hydrology and surrounding land use during the site selection process. This article describes an approach to initial site selection in the San Luis Rey River watershed in southern California that uses watershed‐level information on basin topography and land cover to rank the potential suitability of all sites within a watershed for either preservation or restoration. This approach requires the use of a geographic information system (GIS) to map relative wetness and land cover within a watershed. Relative potential wetness values were derived from U.S. Geological Survey (USGS) 30‐m digital elevation models by calculating the flow that would potentially accumulate at all 30‐m × 30‐m pixels within the water‐shed. Land cover was derived from a Landsat scene covering the 1500 km2 study area. We ranked sites (contiguous groups of pixels > 1 ha with similar land cover) in terms of their potential for restoration or preservation based on their wetness values (low, medium, and high), size, and proximity to existing riparian vegetation. Sites with medium or high wetness values and extant vegetation were identified as potential preservation sites. Agricultural or barren sites with medium to high wetness were identified as potential restoration sites. Approximately 5500 ha (3.67% of the total watershed) were prioritized for preservation or restoration.
A Comparison of Approaches to Prioritizing Sites for Riparian Restoration
Authors: Kentula Mary E.
Published: October 2004

This study compares the results of Olson and Harris (1997) and Russell et al. (1997) in their work to prioritize sites for riparian restoration in the San Luis Rey River watershed. Olson and Harris defined reaches of the mainstem and evaluated the relative potential for restoration and protection based on cover of natural vegetation, land use, and connectivity. Then they used data on geomorphic conditions, plant species composition, and community structure to prescribe strategies for restoration. Russell et al. used a modeling approach within a geographic information system to combine data on wetness and land use/land cover to identify areas with potential for protection and restoration. They prioritized the areas based on patch size and proximity to extant riparian habitat. The mainstem and associated floodplain defined by Olson and Harris was more than twice the size of the area defined by Russell et al., because Olson and Harris considered the entire valley floor, whereas Russell et al. used a wetness index to identify saturated zones within the floodplain. For seven of the twelve management units delineated along the mainstem, the two studies agreed on a strategy of restoration or protection. They differed on two. No comparison could be made of the three units for which Olson and Harris used project review, a unique category. Agreement of the results is due to the similarity of criteria used to identify and rank sites for protection and restoration; disagreement is due primarily to the level of resolution of the data. Both approaches have potential for use in watershed‐level planning. The predictive power of the two approaches may be maximized when they are used in a complementary fashion.
Identifying Sites for Riparian Wetland Restoration: Application of a Model to the Upper Arkansas River Basin
Authors: O'Neill Michael P. , Schmidt John C. , Dobrowolski James P. , Hawkins Charles P. , Neale Christopher M. U.
Published: October 2004

We present a conceptual model for identifying restoration sites for riparian wetlands and discuss its application to reaches within the Upper Arkansas River basin in Colorado. The model utilizes a Geographic Information System (GIS) to analyze a variety of spatial data useful in characterizing geomorphology, hydrology, and vegetation of riparian wetland sites. The model focuses on three basic properties of riparian wetland sites: relative soil moisture, disturbance regime, and vegetative characteristics. A relative wetness index is used to define nominal soil moisture classes within the watershed. These classes generally coincide with uplands (low), channel margins (moderate), and channels or open water (high). Vegetative conditions are characterized using color infrared aerial photographs. Land cover types are grouped into five major land cover classes: riparian, moist herbaceous, bare ground, upland, and open water. Disturbance regime is characterized by a reach‐based index of specific power (ω). Preliminary results indicate that reaches within the Upper Arkansas River basin can be classified as high energy (ω≥ 8 W/m2) or low energy (ω≤ 3W/m2), using discharge estimates that reflect the 10‐year flood event. Field surveys of channel and floodplain conditions show that high‐energy reaches (ω≥ 8W/m2) are characterized by sites where the channel occupies a large proportion of the valley bottom. By contrast, low‐energy reaches (ω, ≤ 3 W/m2) are characterized by meandering channels with wide alluvial valleys. Restoration potential is evaluated as a combination of nominal scores from wetness, land cover, and disturbance indices. Application of these methods to field sites within the Upper Arkansas River basin identifies a wide range of riparian wetland sites for preservation or restoration. Potential sites within identified reaches are prioritized using size and proximity criteria.
Classification and Mapping of Riparian Systems Using Airborne Multispectral Videography
Authors: Neale Christopher M. U.
Published: October 2004

Airborne multispectral videography has become a useful tool for classifying and mapping riparian vegetation because its spectral and digital format has high spatial resolution. This paper explains the processing steps and procedures required to use this type of spectral imagery for riparian vegetation classification and mapping. A description of the Utah State University airborne system is given, along with the image processing steps used for developing finalized products, because these are used in other articles in this volume. Examples of riparian applications using high‐resolution imagery are included.
Riparian Restoration: Current Status and the Reach to the Future
Authors: Landers Dixon H.
Published: October 2004

Nine articles in the special issue of Restoration Ecology addressing the subject of site selection for riparian restoration activities were critically examined for this review. The approaches described make significant and original contributions to the field of riparian restoration. All are interdisciplinary to some extent, often combining the fields of hydrology, geomorphology, and biology in the design of restorations. A common component among the articles is that they take a broad view, if not a watershed view, of restoration site selection. The approaches can be generally described as top‐down strategic approaches to siting restorations, as opposed to the more methods‐ and site‐driven bottom‐up, or tactical, approach. All the articles recognize the importance of developing endpoints related to the ecological function of riparian ecosystems. They succeed in their quest for these indicators of ecological function to varying degrees. The most common indicator used in these papers is riparian vegetation. Several additional elements of scientific investigation, if successfully pursued, could provide vital information and advance our understanding of riparian restoration: developing interdisciplinary approaches more fully; defining endpoints and reference conditions; implementing multiple scale approaches; viewing restorations as experimental ecosystem manipulations; developing a philosophy regarding exotic species; incorporating geographic information systems more often; and integrating science, society, and politics. The foundation provided by the contributions in this issue should provide a strong basis for the rapid advancement of future research in the area of riparian restoration.
Inhibition of human embryonic palatal mesenchymal cell cycle by secalonic acid D: a probable mechanism of its cleft palate induction
Authors: Dhulipala VC , Welshons WV , Reddy CS
Published: October 2004

Structured Abstract

Authors – Dhulipala VC, Welshons WV, Reddy CS

Objective – To assess the mechanism(s) of cleft palate induction by secalonic acid D (SAD) in human embryonic palatal mesenchymal (HEPM) cells and compare them with those evaluated in the murine embryonic palate.

Design – Effect of SAD on HEPM cell proliferation was studied by obtaining dose response curves for cell numbers, uptake of 3H‐thymidine and the expression of proliferating cell nuclear antigen (PCNA). Effects of SAD on cell cycle were assessed by flowcytometry. Cell‐labeling with 3H‐glucosamine and immunoblot analysis were conducted to study SAD effects on the synthesis of glycosaminogycans (GAG) and the expression of fibronectin and tenascin, respectively.

Results – SAD induced a concentration‐dependent decrease in HEPM cell number and 3H‐thymidine uptake beginning at 0.1 μg of SAD/ml. Expression of PCNA and progression of cell cycle from G1 to S phase were inhibited following SAD exposure. Cell viability was significantly reduced only at7.5 μg/ml of SAD or higher indicating that the reduction in cell numbers by SAD at lower concentrations is likely due to reduced proliferation and at higher concentrations due to both reduced proliferation and cell death. Synthesis of extra cellular matrix components (GAGs, fibronectin or tenascin) by HEPM cells, however, was not inhibited by SAD.

Conclusion – The results of these studies confirmed those of our previous studies with mice and the MEPM cells that SAD may induce cleft palate by reducing numbers of palatal mesenchymal cells by inhibition of their proliferation thereby leading to a reduction in the size of the developing palate shelves.
The Combusting Properties of Anthracite in a 410 t/h CFB Boiler
Authors: Lu Xiaofeng , Amano Ryo S.
Published: October 2004

According to the results of an optimized operation test carried out on a 410 t/h CFB boiler, the measured combusting properties of anthracite in the large CFB boiler are provided in this paper. These properties include: operating and designing parameters affected on the carbon content in fly ash, distribution of oxygen in the furnace, distribution of temperature in the furnace, distribution of bed pressure, and operation under low load. Some methods used to improve the CFB boiler operation are discussed in the paper.
Evaluation of a Statistical Method for Assessing Infill Production Potential in Mature, Low-Permeability Gas Reservoirs
Authors: Guan L. , McVay D. A. , Jensen J. L. , Voneiff G. W.
Published: October 2004

Background. Identifying the locations and amounts of unproduced gas in mature reservoirs is often a challenging problem, due to several factors. Complete integrated reservoir studies to determine drilling locations and potential of new wells are often too time-consuming and costly for many fields. In this work, we evaluate the accuracy of a statistical moving-window method (MWM) that has been used in low-permeability (“tight”) gas formations to assess infill and recompletion potential. The primary advantages of the technique are its speed and its limited need for data, using only well location and production data. Method of Approach. To test the method, we created a number of hypothetical reservoirs and calculated infill well potential using a reservoir simulator. We used the MWM to analyze these data sets, then compared results to those from the reservoir simulations. Results. The results validate empirical observations made using MWM during field evaluations. Depending on the level of reservoir heterogeneity, the MWM infill predictions for individual wells can be off by more than ±50%. The MWM more accurately predicts the production potential from a group of infill candidates, the MWM, however, more often to within 10%. We describe a procedure to estimate the number of wells needed to predict production potential to within a stipulated accuracy. The ability of MWM to accurately predict production performance for groups of wells shows that it can be a useful tool for scoping studies or identifying areas for more detailed evaluation.
Innovative Diffusion Driven Desalination Process
Authors: Klausner James F. , Li Yi , Darwish Mohamed , Mei Renwei
Published: October 2004

An innovative diffusion driven desalination (DDD) process is presented, and its performance based on thermodynamic considerations is thoroughly explored. The desalination is driven by water vapor saturating low humidity air flowing through a diffusion tower. Liquid water is condensed out of the air/vapor mixture in a direct contact condenser. The desalination process is suitable for operation at low temperatures and may be driven by waste heat with low exergy. It is demonstrated that the DDD process can yield a fresh water production efficiency of 4.5% with thermal energy consumption of 0.56 kWh per kilogram of fresh water production based on a feed water temperature of only 50°C. An example is discussed in which the DDD process utilizes waste heat from a 100 MW steam power plant to produce 1.51 million gallons of fresh water per day.
The Role of Well Testing in Recognizing Deferred Production Revenue
Authors: Mehdizadeh P. , Perry D. T.
Published: October 2004

Well testing is routinely performed to evaluate the performance of a well, which establishes the allocation factor for the lease, which in turn establishes tax and royalty basis. Most well testing is done with conventional gravity separators, which separates the produced stream into oil, water, and gas components and measures these individual components as individual streams. New multiphase measurement technology improves well test results through improved accuracy, consistency, and more frequent well testing. This paper examines the implication of these improved capabilities to recognize well problems and optimize production. A simple economic model is provided that an operator can use to assess the balance between the cost of performing periodic well tests and the benefits of more quickly discovering well problems that can result in less than expected production. The model relates the cost of decreased production, as the result of unforeseen changes in the well, to the frequency and accuracy of the well tests. The model derives an optimum test interval that minimizes the total cost of well testing and deferred production on the basis of the probability that a higher than normal decline in production rate can be detected by well testing. The model is then used in several field examples to assess the optimum period between well tests and how the optimum period can lead to reduced cost of operation and improved production.
A Computational Model of a Combined Cycle Power Generation Unit
Authors: Ramaprabhu V. , Roy R. P.
Published: October 2004

A computational model of a combined cycle power generation unit is developed and applied to one operated by a local utility company. The objective is to predict the performance of this unit by carrying out energy and exergy analyses of its components. The model is based on thermodynamic, heat transfer, and psychrometric principles, and includes an inlet air conditioning (fogging) system for the gas turbine cycle. To evaluate the model, simulation results are compared with available plant test data at rated load with and without the inlet fogging system in operation.
Influence of Fluid Viscosity on the Hydraulic Fracturing Mechanism
Authors: Ishida Tsuyoshi , Chen Qu , Mizuta Yoshiaki , Roegiers Jean-Claude
Published: October 2004

Cubical granite specimens were fractured by borehole pressurization of 1 cP water, 80 cP oil and via a urethane sleeve. Viscous oil tends to generate thick and planar cracks with few branches, while water tends to generate thin and wavelike cracks with many secondary branches. While penetrating fluids extended cracks rapidly, pressurization via a urethane sleeve led to stepwise crack extension. Fault-plane solutions of AE (Acoustic Emission) events indicated that shear-type mechanisms were dominant during water injection and sleeve pressurization, whereas tensile-type mechanisms were dominant during oil injection. These results could be helpful in optimizing stimulation treatments in the petroleum industry.
Design of a heating-cooling stage for scanning tunneling microscopy and temperature programmed desorption experiments
Authors: Illingworth A. , Zhou J. , Ozturk O. , Chen D. A.
Published: October 2004

A heating-cooling stage with detachable thermocouple contacts and an electron beam heater has been designed and tested for use in temperature programmed desorption and scanning tunneling microscopy (STM) experiments. This sample stage is compatible with the Omicron variable temperature STM, and the thermocouple contacts can be used with both the standard Ta plates and the variable temperature sample holder. The stage can also be retrofitted to the standard Omicron manipulation stage without requiring any additional electrical connections.
Improved characteristics of metamorphic InAlAs∕InGaAs high electron mobility transistor with symmetric graded InxGa1−xAs channel
Authors: Li Yih-Juan , Hsu Wei-Chou , Chen I-Liang , Lee Ching-Sung , Chen Yeong-Jia , Lo Ikai
Published: October 2004

A metamorphic high electron mobility transistor with symmetric graded InxGa1−xAs channel has been successfully grown by molecular beam epitaxy system. Due to the lower interface roughness scattering, the improved electron mobility as high as 9500(30600)cm2∕Vs at 300(77)K is achieved. By using the self-consistent method, three subbands in the graded channel are found, which is matched to the Shubnikov-de Haas data. By using the graded channel, In0.425Al0.575As Schottky layer, and undoped InP setback layer, a high gate breakdown voltage of 24V is obtained. Meanwhile, the measured current gain cutoff frequency fT and maximum oscillation frequency fmax for a 1.5μm gate device are 18.9 and 48.4GHz, respectively.
Atomic force microscope based analysis of bound and bound+mobile phase monolayer behavior under mechanical and electrical stress
Authors: Nainaparampil J. J. , Eapen K. C. , Zabinski J. S.
Published: October 2004

One of the major problems with microelectromechanical systems (MEMS) is the stiction caused by capillary, van der Waals, electrostatic, and chemical forces. Self-assembled monolayers are extensively used to resolve this problem and they have been effective to a certain extent. It has been noted that the molecular weight, entanglement of molecules with asperities, time dependent interactions between asperities and monolayers, and surface migration play major roles in the failure of these coatings. In addition, tribological stressing and diffusion at increased temperature can also cause monolayers to fail. In this study, atomic force microscopy (AFM) and related techniques are used to analyze the behavior of bound monolayer films of 1-decanol and bound 1-decanol combined with a mobile phase (a pentaerythritol ester). Molecular reorientation and surface detachment under electrostatic force increase with increasing electric field between the AFM tip and the film. The AFM tip is used as a single asperity contact to study the atomic scale film failure dynamics of MEMS materials. The micronanotribology of both bound and bound/mobile systems show significant differences in tribochemistry and replenishing characteristics. Bound and mobile phase films exhibit desirable tribological characteristics that extend the reliable life of MEMS devices, which is demonstrated in real device tests.
Investigation of nodule growth in ion beam sputtered Mo∕Si multilayers
Authors: Quesnel E. , Hue J. , Muffato V. , Pellé C. , Lamy P.
Published: October 2004

In this study, the nodule growth in ion beam sputtering Mo∕Si coatings used for extreme-ultraviolet (EUV) lithography masks has been studied in relation with the number of Mo∕Si pairs (period 7 nm). To trigger this growth, initial particles of different sizes (d=40–155nm) were used. With a deposition angle of 30° and after the deposition of 40–60 Mo∕Si pairs, the lateral size of nodules was found to grow up to ∼2d while its height ranged from d∕6 to d∕2 depending on the initial particle diameter. This lateral growth was demonstrated to mainly result from shadowing effect. Besides, a vertical smoothing effect was evidenced even in the case of relatively large initial seed particles (70–155 nm). It is attributed to adatom surface diffusion which is also thought to promote a slowdown in the nodule lateral growth when increasing the coating thickness. Finally, a real case of mask blank realization is presented showing that a good knowledge of nodule growth is essential to properly analyze the defect characteristics of EUV mask blanks.
Capture of flaked particles during plasma etching by a negatively biased electrode
Authors: Moriya Tsuyoshi , Ito Natsuko , Uesugi Fumihiko
Published: October 2004

A bias electrode was installed inside an etching chamber to investigate the effect of bias voltage on particle behavior. To detect flaked particles individually and to determine their trajectories, an in situ particle monitoring system which employs laser light scattering was employed. Consequently, it was found that particles were attracted when negative voltage was supplied to the bias electrode. However, particles were pushed toward the wafer when positive voltage was applied. It was thus clarified that the flaked particles have positive charges, and concluded that negative bias voltage can control their behavior and keep the wafer surface particle free, without serious affect on the etching process.
Effects of annealing treatment on microstructure and photocatalytic performance of nanostructured TiO2 coatings through flame spraying with liquid feedstocks
Authors: Yang Guan-Jun , Li Chang-Jiu , Han Feng , Huang Xin-Chun
Published: October 2004

Nanostructured titanium dioxide (TiO2) photocatalytic coating was deposited through flame spraying with liquid feedstocks. The effect of annealing treatment on the microstructure of the TiO2 coatings was investigated. The microstructure of the coatings was characterized by x-ray diffraction, thermal analysis and transmission electron microscopy. The photocatalytic performance was characterized by photodegradation of gaseous acetaldehyde. The results showed that the as-sprayed nanostructured titania deposited by flame spraying with liquid feedstocks is mainly composed of anatase phase. X-ray diffraction analysis showed that annealing at a temperature higher than 600 °C results in transformation of the anatase phase to rutile phase. Transmission electron microscopy examination revealed that the particles in the deposit remain in their original nano-size when annealing temperature is lower than 800 °C. Thermal analysis suggested that the transformation from anatase to rutile may start at a temperature of around 400 °C. On the other hand, the results evidently indicated that photocatalytic performance is not directly related to the anatase content in the coating. The onset of the phase transformation dramatically degrades the photocatalytic activity. Those facts suggest that the transformation of the anatase phase to rutile phase begins at the surface of the particles which may result in the formation of a surface shell of the rutile phase TiO2.
Nitrogen interface engineering in Al2O3 capacitors for improved thermal stability
Authors: Kirsch P. D. , Park D.-G. , Chan K. K. , D’Emic C. , Bruley J. , Jammy R.
Published: October 2004

Monolayer (ML) quantities of SiNx have been placed at both top and bottom interfaces of Al2O3 capacitors to improve thermal stability and electrical performance. Bottom SiNx was formed with NH3 anneal. Top SiNx was formed with ultrahigh vacuum chemical vapor deposition (UHVCVD) utilizing SiH4 and NH3. Characterization has been done with current–voltage (I–V), capacitance–voltage (C–V) transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS) after 1050°C–30s anneal. I–V measurements show leakage current reduction of 50× with 2 ML UHVCVD SiNx at the polycrystalline-Si∕dielectric interface, while C–V measurements show that capacitance equivalent thickness increases just 1.2Å. The leakage current reduction is attributed not only to the increased thickness but also to interface passivation as a result of SiNx deposition. EELS N line profiles show evidence of monolayer quantities of N at both top and bottom interfaces. Good thermal stability beyond the 1050°C-30s anneal for the capacitors with UHVCVD SiNx is also demonstrated. Specifically, leakage current remains below 1×10−8A∕cm2 after four thermal stresses to or exceeding 1000°C.
Modeling SiC surface roughness using neural network and atomic force microscopy
Authors: Kim Byungwhan , Kim Sungmo , Lee Byung-Teak
Published: October 2004

A prediction model for surface roughness was constructed using a neural network and atomic force microscopy. The silicon carbide etch process was characterized by a 25 full factorial experiment. The experimental ranges of process parameters were 600–900W source power, 50–150W bias power, 4–16mTorr pressure, 0–80% O2 percentage, and 6–12cm gap. The model factors were optimized by means of a genetic algorithm. The optimized model had a root mean-squared error of 0.11nm. From the model, various plots were predicted while being supported by actual measurements. The dc bias induced by each process parameter was correlated to the surface roughness. Increasing the bias power increased the surface roughness. In contrast, the surface roughness decreased as the dc bias was larger than about 600V. The surface roughness was strongly correlated to the source power-induced dc bias only at low bias powers. The pressure effect was clear only as the dc bias was maintained at 480V. For the variations in the O2 percentage, the dc bias role was insignificant.
Towards all-dry lithography: Electron-beam patternable poly(glycidyl methacrylate) thin films from hot filament chemical vapor deposition
Authors: Mao Yu , Felix Nelson M. , Nguyen Peter T. , Ober Christopher K. , Gleason Karen K.
Published: October 2004

Chemical vapor deposition (CVD) of resist thin films is a dry processing alternative to the conventional spin casting of resists. However, the sensitivity and resolution of plasma CVD resists are limited due to the crosslinked structure in the deposited films. In this study, we demonstrated hot filament chemical vapor deposition (HFCVD) of poly(glycidyl methacrylate) (PGMA) thin films with improved sensitivity and resolution under electron-beam irradiation. We also demonstrated supercritical CO2 development of the HFCVD PGMA thin films, which indicates the potential for an “all-dry” lithographic process. The pendent epoxide groups were retained in the low-energy HFCVD process, and linear polymeric structure was achieved. The HFCVD PGMA films have an electron-beam sensitivity of 27μC∕cm2 using conventional development and an electron-beam sensitivity of 15μC∕cm2 using supercritical CO2 development. Decreasing film number-average molecular weight (Mn) decreases sensitivity but improves resolution by alleviating the swelling of small features. The PGMA film with Mn 4700g∕mol resolved 80nm features using conventional development and 300nm features using supercritical CO2 development.
Compound-target sputtering for niobium carbide thin-film deposition
Authors: Liao M. Y. , Gotoh Y. , Tsuji H. , Ishikawa J.
Published: October 2004

In this Letter, we report the deposition of niobium carbide (NbC) thin films by using a rf magnetron sputtering apparatus with a NbC target. The films were characterized with regard to their structure, chemical bonding states, and composition. It was revealed that cubic NbC films could grow at ambient temperature. The film composition was estimated as a function of deposition parameters. It was found that excess carbon exists within the films deposited at low working argon pressure. This excess carbon seems to be associated with poor crystallinity. Using the present deposition method, oxygen content in the films could be controlled at an extremely low level. Either physical scattering or a chemical etching mechanism was considered to be responsible for the loss of carbon in the film.
Physics Outreach for WYP
Authors: Conlon Julie
Published: October 2004

The year 2005 has been designated The World Year of Physics (WYP). The purpose of this paper is to give some examples of how physicists at all levels may help to make the WYP a success in bringing physics to the general public. Specifically, I want to share some of the ideas and techniques that have been developed as a part of Purdue University's School of Science outreach program. An important facet of this program is PEARLS (Physics Educational Actvities, Resources and Learning Strategies). PEARLS views outreach as a “menu” of options to meet various needs and requests, whether they come from schools, scout groups, nursing homes, etc. (see Fig. 1). We've presented to all!
Cis-Acting Regulatory Variation in the Human Genome
Authors: Pastinen Tomi , Hudson Thomas J.
Published: October 2004

The systematic screening of the human genome for genetic variants that affect gene regulation should advance our fundamental understanding of phenotypic diversity and lead to the identification of alleles that modify disease risk. There are several challenges in localizing regulatory polymorphisms, including the wide spectrum of cis-acting regulatory mechanisms, the inconsistent effects of regulatory variants in different tissues, and the difficulty in isolating the causal variants that are in linkage disequilibrium with many other variants. We discuss the current state of knowledge and technologies used for mapping and characterizing genetic variation controlling human gene expression.
RELATIVE GEOMETRIC INVARIANT THEORY AND UNIVERSAL MODULI SPACES
Authors: HU YI
Published: October 2004

We expose in detail the principle that the relative geometric invariant theory of equivariant morphisms is related to the GIT for linearizations near the boundary of the G-effective ample cone. We then apply this principle to construct and reconstruct various universal moduli spaces. In particular, we constructed the universal moduli space over [Formula: see text] of Simpson’s p-semistable coherent sheaves and a canonical rational morphism from the universal Hilbert scheme over [Formula: see text] to a compactified universal Picard.