bluuebunny/crossref_metadata_2025 huggingface dataset:
Disturbances in dental development and craniofacial growth in children treated with hematopoietic stem cell transplantation
Authors: Vesterbacka M. , Ringdén O. , Remberger M. , Huggare J. , Dahllöf G.
Published: January 2012

Vesterbacka M., Ringdén O., Remberger M., Huggare J., Dahllöf G.  Disturbances in dental development and craniofacial growth in children treated with hematopoietic stem cell transplantation.  Orthod Craniofac Res 2012;15:21–29 © John Wiley & Sons A/S

Structured Abstract

Objectives –  To investigate the correlation between age, degree of disturbances in dental development, and vertical growth of the face in children treated with hematopoietic stem cell transplantation (HSCT).

Patients –  39 long‐term survivors of HSCT performed in childhood and transplanted before the age of 12, at a mean age of 6.8 ± 3.3 years.

Methods –  Panoramic and cephalometric radiographs were taken at a mean age of 16.2 years. For each patient two age‐ and sex‐matched healthy controls were included. The area of three mandibular teeth was measured and a cephalometric analysis was performed.

Results –  The mean area of the mandibular central incisor, first and second molar was significantly smaller in the HSCT group, and the vertical growth of the face was significantly reduced, especially in the lower third, compared to healthy controls. A statistically significant correlation between age at HSCT, degree of disturbances in dental development, and vertical growth of the face was found. Children subjected to pre‐HSCT chemotherapy protocols had significantly more growth reduction in vertical craniofacial variables compared to children without pre‐HSCT chemotherapy. Conditioning regimens including busulfan or total body irradiation had similar deleterious effects on tooth area reduction and craniofacial parameters.

Conclusions –  The younger the child is at HSCT, the greater the impairment in dental and vertical facial development. This supports the suggestion that the reduction in lower facial height found in SCT children mainly is a result of impaired dental development and that young age is a risk factor for more severe disturbances.
Epigallocatechin‐3‐gallate and penta‐O‐galloyl‐β‐d‐glucose inhibit protein phosphatase‐1
Authors: Kiss Andrea , Bécsi Bálint , Kolozsvári Bernadett , Komáromi István , Kövér Katalin E. , Erdődi Ferenc
Published: January 2012

Protein phosphatase‐1 (PP1) and protein phosphatase‐2A (PP2A) are responsible for the dephosphorylation of the majority of phosphoserine/threonine residues in cells. In this study, we show that (–)‐epigallocatechin‐3‐gallate (EGCG) and 1,2,3,4,6‐penta‐O‐galloyl‐β‐d‐glucose (PGG), polyphenolic constituents of green tea and tannins, inhibit the activity of the PP1 recombinant δ‐isoform of the PP1 catalytic subunit and the native PP1 catalytic subunit (PP1c) with IC50 values of 0.47–1.35 μm and 0.26–0.4 μm, respectively. EGCG and PGG inhibit PP2Ac less potently, with IC50 values of 15 and 6.6 μm, respectively. The structure–inhibitory potency relationships of catechin derivatives suggests that the galloyl group may play a major role in phosphatase inhibition. The interaction of EGCG and PGG with PP1c was characterized by NMR and surface plasmon resonance‐based binding techniques. Competitive binding assays and molecular modeling suggest that EGCG docks at the hydrophobic groove close to the catalytic center of PP1c, partially overlapping with the binding surface of microcystin‐LR or okadaic acid. This hydrophobic interaction is further stabilized by hydrogen bonding via hydroxyl/oxo groups of EGCG to PP1c residues. Comparative docking shows that EGCG binds to PP2Ac in a similar manner, but in a distinct pose. Long‐term treatment (24 h) with these compounds and other catechins suppresses the viability of HeLa cells with a relative effectiveness reminiscent of their in vitro PP1c‐inhibitory potencies. The above data imply that the phosphatase‐inhibitory features of these polyphenols may be implicated in the wide spectrum of their physiological influence.
‘MAYBE YOU DON'T ACTUALLY EXIST’: CONTAINING SHAME AND SELF‐HARM IN A SCHOOL COUNSELLING SERVICE
Authors: Catty Jocelyn
Published: January 2012

abstract

In this paper, I argue that the school counsellor occupies a liminal position in the school environment, on the boundary between the private and the public, and that this position intrinsically reflects the paradoxical nature of shame, at once hidden and viewed. I review arguments that locate the development of primitive shame in early containment failure, with shame being defended against by rage against others or the self. I argue that the school counsellor's position commonly oscillates through the three positions of the child–home–school triangle, but that this is felt particularly acutely when the dynamics projected through this triangle are those of shame and shaming. For adolescents, the paradoxical nature of shame also finds a counterpart in self‐harm, a simultaneously hidden and viewed act which I see as a mapping of shame on the body. In exploring the operation of shame in self‐harming students, I also argue that chance encounters between counsellor and student in the external school world render projections about intimacy, intrusion and shame particularly powerful.
Delving into somatic variation in sporadic melanoma
Authors: Walia Vijay , Mu Euphemia W. , Lin Jimmy C. , Samuels Yardena
Published: January 2012

Melanoma, the most aggressive form of skin cancer, has increased in incidence more rapidly than any other cancer. The completion of the human genome project and advancements in genomics technologies has allowed us to investigate genetic alterations of melanoma at a scale and depth that is unprecedented. Here, we survey the history of the different approaches taken to understand the genomics of melanoma – from early candidate genes, to gene families, to genome‐wide studies. The new era of whole‐exome and whole‐genome sequencing has paved the way for an in‐depth understanding of melanoma biology, identification of new therapeutic targets, and development of novel personalized therapies for melanoma.
Ameloblastic carcinoma of mandible: Report of intriguing presentation
Authors: Guledgud Mahima V. , Patil Karthikeya , Malleshi Suchetha N.
Published: January 2012

Ameloblastic carcinoma, a rare aggressive odontogenic tumor occurs predominantly in the mandibular posterior region. Clinical symptoms are varied with possible metastasis to the regional lymph nodes or lung. Radiographically, it usually manifests as an ill‐defined osteolytic radiolucency. Histologically, it resembles ameloblastoma that is mostly devoid of its familiar microscopic features in combination with prominent cytological atypia and mitotic activity. A rare and atypical presentation of ameloblastic carcinoma of the mandible with unconventional clinical and radiological features is documented in this case report.
Methane source strength and energy flow shape methanotrophic communities in oxygen–methane counter‐gradients
Authors: Krause Sascha , Lüke Claudia , Frenzel Peter
Published: January 2012

The role of microbial diversity for ecosystem functioning has become an important subject in microbial ecology. Recent work indicates that microbial communities and microbial processes can be very sensitive to anthropogenic disturbances. However, to what extent microbial communities may change upon, resist to, or overcome disturbances might differ depending on substrate availability. We used soil from an Italian rice field in gradient microcosms, and analysed the response of methanotrophic communities to an NH4+ pulse as a potential disturbance under two different CH4 source strengths. We found a significant influence of source strength, i.e. the energy flow through the methanotrophic community, while NH4+ had no effect. Our data suggest that historical contingencies, i.e. nitrogen fertilization, led to an ammonium‐tolerant MOB community. Methanotrophs were able to oxidize virtually all CH4 diffusing into the oxic–anoxic boundary layer regardless of NH4+ addition. Total and active methanotrophic communities were assessed by a pmoA‐specific microarray. From the reservoir of dormant methanotrophs, different species became active with Methylobacter and an environmental cluster affiliated with paddy soils being indicative for high CH4 source strength. Thus, a microbial seed bank is an important prerequisite to maintain functioning in a fluctuating environment.
The Use and Role of Pop Culture in Heritage Language Learning: A Study of Advanced Learners of Korean
Authors: Choi Jayoung , Yi Youngjoo
Published: January 2012

Despite the important use of pop culture in many instructional settings, its use in the heritage language (HL) classroom remains largely unexplored. Thus, this article reports findings from classroom‐based qualitative research that examined the use and role of pop culture in advanced Korean HL learners’ literacy engagement and identity construction. Data analyses of the learners’ reading presentations and writing projects revealed that they extensively drew upon the heritage media and pop culture for their in‐class literacy practices. Pop culture served as a contact point for their literacy practice, helped reexamine or strengthen their ethnic identity from a global perspective, and provided a window to discuss social issues and explore them. Findings suggest pedagogical implications for using pop culture in HL and foreign language classrooms.
Mood modulation by food: An exploration of affect and cravings in ‘chocolate addicts’
Authors: Macdiarmid Jennie I. , Hetherington Marion M.
Published: January 2012

To test the hypothesis that some foods are eaten to alter mood, the relationship between mood and intake of chocolate was investigated in 40 women. Twenty self‐identified chocolate 'addicts' and 20 controls rated hunger, mood, intensity of craving and amount of chocolate eaten in a diary for seven consecutive days. The 'addicts' reported a significantly greater number of eating episodes and consumed a larger amount of chocolate than controls. 'Addicts' also rated depression, guilt and craving higher and feeling content and relaxed as lower before eating than controls. However, eating chocolate resulted in increased feelings of guilt in the 'addicts' and no significant changes in feeling depressed or relaxed. On indices of disordered eating and depression, 'addicts' scored significantly higher than controls; however, eating chocolate did not improve mood. Although chocolate is a food which provides pleasure, for those who consider intake of this food to be excessive, any pleasure experienced is short lived and accompanied by feelings of guilt.
An open trial of exposure therapy based on deconditioning for post‐traumatic stress disorder
Authors: Thompson J. A. , Charlton P. F. C. , Kerry R. , Lee D. , Turner S. W.
Published: January 2012

Twenty‐three patients who had experienced a major stressful event were given a debriefing session followed by eight weekly sessions of imaginal exposure and in vivo exposure. Patients recounted their traumatic experiences aloud, using the first person and the present tense, and included as much detail as possible. This account was audiotaped and patients were asked to listen to the tape between treatment sessions. There were reductions of 42 per cent in the Impact of Events Scale (IES), of 61 per cent in the General Health Questionnaire (GHQ), of 38 per cent in the Symptom Checklist‐90 (SCL‐90) questionnaire, and of 35 per cent in the Clinician Administered Post‐Traumatic Stress scale (CAPS), all of which were statistically significant. The number of patients who satisfied the diagnostic criteria for posttraumatic stress disorder was halved.
Social and cognitive approaches to depression: Towards a new synthesis
Authors: Champion L. A. , Power M. J.
Published: January 2012

A description of a social‐cognitive theory of depression is presented which combines the concepts of mental models, personal goals and social roles. An analysis is made of how a number of proposals about the onset of depression can be summarized as the loss of a valued goal or social role in an individual who has few other sources of self‐worth. In subsequent sections, limitations of the theory are outlined, and the relationship between the present theory and other theories of depression is briefly considered.
Advances in Steam Turbines for Marine Propulsion
Authors: Somes A. D.
Published: January 2012

Advances in the design and construction of steam turbines for the propulsion of ships growing out of current trends in the construction and operation of merchant ships, as distinct from naval vessels, are considered. The effects of increases in power and steam conditions, and changes in classification rules, are examined and assessed in relation to the turbines. New concepts and methods in design are discussed and experience with advanced designs is indicated. Some examples of actual details of construction developed to meet new conditions are presented.
Field Testing and Adjusting of Hydraulic Turbine-Generator to Improve System Regulation
Authors: Stone H. M.
Published: January 2012

This paper presents some of the results and methods of extensive hydro prime-mover governor tests conducted at the Big Creek Hydro System of the author’s company. Each governor response was improved by making co-ordinated governor adjustments. Frequency-response curves and dead band X-Y charts are included to show the improvement obtained. Frequency dead band and the governor transient response time were improved as much as 50 per cent. A good share of the credit for the results and improvements obtained is due to the use of adequate test equipment. As described elsewhere, the Mobile Dynamics Laboratory for Studying Generating Plant Controls and Governors was designed and used for extensive preliminary tests. Later, a small compact test rig, described in this paper, was assembled and used for the routine testing and adjusting of governors.
Reduction of Turbine Runner Vibration and Noise
Authors: Taylor F. C.
Published: January 2012

A re´sume´ of hydraulic turbine vibration experience in the U. S. Army Engineer Division, Southwestern, Corps of Engineers, hydroelectric stations and methods used in reducing the vibration and noise to a more satisfactory level. These hydroelectric stations are scattered over a rather large area extending from Southern Missouri to Central Texas. All of the hydroelectric installations are part of multiple purpose projects primarily designed for flood control. This provides an operating head variation of nearly 50 per cent of the turbine design head at some projects. There are 18 units presently in operation, all of the Francis type, with design heads varying from 59 to 190 ft.
Experiences With Hydraulic Prime Mover Controls
Authors: Schleif F. R. , Johnstone L. M.
Published: January 2012

This paper is devoted to the prime mover control aspects of some problems encountered by the U. S. Bureau of Reclamation with hydrogenerating units. The problems include governor instability, remote control of governor dashpot compensation, and control associated with overspeed following load rejections. First symptoms were often complicated by contributions from voltage regulators, relays, oil pumps, or tie-line control apparatus. Attention is directed to the components or effects principally responsible.
Aerodynamic Design and Performance of Five-Stage Transonic Axial-Flow Compressor
Authors: Kovach Karl , Sandercock D. M.
Published: January 2012

A five-stage axial-flow compressor with all rotors operating with transonic relative inlet Mach numbers was designed as a research vehicle at the Lewis Research Center in 1952. The compressor was designed and tested as a component of a turbojet engine. This paper summarizes the research work done on this compressor including the aerodynamic design and detailed performance characteristics.
A Study of Sulfur Reactions in Furnace Deposits
Authors: Weintraub M. , Goldberg S. , Orning A. A.
Published: January 2012

A study was made of absorption of sulfur from synthetic flue gas by coal ash. When fly ash was placed in a temperature gradient like that in a deposit on a boiler tube, maximum absorption was found in the coldest layer. When held at constant temperature, maximum absorption was found at 1100 F. The amount of absorption was highest for fly ash from furnaces in which serious deposit formation was observed. It was also highest for fly ash containing the highest content of sodium and potassium. The sulfur is probably absorbed as mixtures of normal sulfates, pyrosulfates, and such compounds as potassium-ferric trisulfate. A liquid phase of these compounds in contact with tube metal causes corrosion. The maximum sulfur absorption found at 1100 F coincides with a maximum at the same temperature that has been observed for external tube-metal corrosion.
Performance of Silicon Solar Cells at High Levels of Solar Radiation
Authors: Pfeiffer C. , Schoffer P. , Spars B. G. , Duffie J. A.
Published: January 2012

Current-voltage characteristics of silicon solar cells cooled by conduction or convection at radiation levels up to 60 langleys per minute are reported for several cell temperatures. Maximum power output noted was approximately 65 milliwatts per square centimeter. The use of cells as flux measuring devices is noted.
Transient Loading Improvements for Large Steam-Electric Generating Units
Authors: Strohmeyer Charles
Published: January 2012

The intent of this paper is to discuss the ultimate in operating flexibility during transient conditions that can be built into new designs having steam conditions of 2400 psig, 1050/1000 F reheat or above. The following discussion proposes an over-all operating philosophy in the hope of developing better understanding among the engineers, operators, and equipment manufacturers. Emphasis is placed upon steam temperature control to suit various turbine operating conditions. New methods proposed include a means of raising throttle steam enthalpy during hot turbine starts, a control and/or supervisory system for regulating unit start-ups and shutdowns, and a new means of cooling the low pressure turbine exhaust during start-up. As a result, for short duration turbine generator shutdowns as 8 hours, units may be unloaded rapidly at full pressure and in some cases may be restarted from turning gear to one third load restoring design primary steam temperature and pressure in as little as 35 minutes without sacrifice of safety.
Reactions of Magnesium With Inorganic Constituents of Heavy Fuel Oil and Characteristics of Compounds Formed
Authors: Niles W. D. , Sanders H. R.
Published: January 2012

High temperature reactions of magnesium with heavy fuel oil ash have been studied in static reaction tests and the products formed have been identified. The effect of SO3 partial pressure on fuel ash reactions and the corrosivity of the compounds formed have been established. This work has enabled development of a systematic method of predicting deposit compositions and characteristics from a knowledge of fuel ash composition and burner operating conditions. Extensive comparisons are made between predicted compositions and actual analysis of deposits obtained from a wide variety of commercial burner units.
An Experimental Investigation of the Use of Supersonic Driving Jets for Ejector Pumps
Authors: Deleo R. V. , Rose R. E. , Dart R. S.
Published: January 2012

The main purpose of this study was to establish pumping and thrust performance comparisons between ejector configurations utilizing sonic and supersonic parallel flow nozzles. The application of interest in this particular investigation was in boundary-layer control for turbo-jet aircraft. In order to optimize the performance, it was necessary to vary systematically the geometric parameters of mixing tube length to diameter ratio. The primary or driving jet pressure was an important independent parameter and was variable up to 32.0 times the ambient pressure. An ejector-vacuum chamber installation was fabricate and designed in order that the desired parameter ranges might be obtained. Both the ejector and thrust table were mounted inside the vacuum chamber. Results of the investigation indicated substantial improvement in the pumping and thrust performance of the ejector with supersonic primary nozzles as compared to the sonic jet. A mixing tube length of ten mixing tube diameters was found to give the most satisfactory over-all pumping performance. Comparisons between experimental results and theory for the supersonic primary nozzle are included. Experimental investigations were also conducted using a sonic primary nozzle containing a center body at primary temperatures up to 1000° F.
A Digital Computer Program for Processing Turbine-Generator Acceptance Test Data
Authors: Maneatis G. A. , Barr W. H.
Published: January 2012

This paper describes a digital computer program which processes rapidly all of the data taken during a steam turbine-generator acceptance test. Specifically, it determines all thermodynamic properties of steam and water, computes corrected test heat rate, and finally develops a contract heat rate for purposes of comparison with manufacturer’s guarantees. The application of this program on two 330-megawatt units is discussed. The thinking leading to certain key decisions involving the ultimate approach taken is presented for the benefit of those contemplating a similar effort.
The Solubility of Copper and Its Oxides in Supercritical Steam
Authors: Pocock F. J. , Stewart J. F.
Published: January 2012

This paper contains a study of the solubility of copper and its oxides in supercritical steam which was undertaken because of difficulties experienced with copper deposition in the high-pressure turbine of the Ohio Power Company’s Philo 6 supercritical steam-generating cycle. This study shows that copper has appreciable solubility in superheated supercritical steam. The extent of solubility is apparently a function of the oxidation state of the metal, with the highest state of oxidation (CuO) showing the greatest solubility. A slightly increased solubility was effected by increasing pH values from ∼7.5 to ∼9.5 with ammonia. It is also shown that copper solubility is principally a function of pressure over the narrow temperature range tested (900–1150 F) probably because this parameter has the greatest effect on specific volume.
Development of a High Temperature Liquid Metal Turbopump
Authors: Kelly R. W. , Wood G. M. , Marman H. V.
Published: January 2012

High performance, mobile, nuclear power plants utilizing liquid metals require high temperature pumps to circulate these heat transport fluids. These pumps must have moderately high efficiency, small size, low weight, and high reliability. In order to satisfy these requirements, centrifugal pumps directly coupled to gas turbines are utilized. As part of the aircraft nuclear power plant development program, the 3000 gpm stainless steel turbopump described in this paper was designed and tested in NaK at temperatures up to 1300 F.
Asymmetric Inlet Flow in Axial Turbomachines
Authors: Seidel Barry S.
Published: January 2012

A modified actuator disk analysis is made which, through an improved prediction of the blade forces, attempts to give closer correspondence with experiment than the previous theory. The fluid is assumed inviscid and incompressible. Perturbations to the two-dimensional flow through an isolated blade row are considered. The steady flow equations of motion and continuity are linearized. According to experiments conducted on an isolated compressor rotor, the present theory offers an improvement, compared to previous theory, in the prediction of distortion attenuation, effects of flow rate, and effects of varying chord/spacing ratio.
Development and Evaluation of a Supercharged Steam Generating System
Authors: Fritz W. A. , Cohen L.
Published: January 2012

The Naval Boiler and Turbine Laboratory has recently completed an evaluation and development program of a supercharged steam generator system. The installation for this program was the only one of its type in the United States. The agenda developed and the test facility and instrumentation system designed were specifically adapted to the requirements of a supercharged system. Modifications required during the development and the test results obtained are briefly discussed. As a result of this program, supercharged steam generators are being installed in the Navy’s DE1040 Class ships.
A Procedure for Calculating the Packet Frequencies of Steam Turbine Exhaust Blades
Authors: Dea´k A. L. , Baird R. D.
Published: January 2012

A method of analysis is presented which gives all of the natural frequencies and mode shapes of a laced group of rotating steam turbine exhaust blades. Both flexural and torsional motions are considered, which are coupled through the lacing wires. The frequency determinant of the vibrating packet is derived by the Fundamental Solution technique. The analysis is facilitated by separating the symmetric and skewsymmetric modes of vibration. The natural frequencies are found by the conventional trial-and-error procedure. Digital computation is required.
An Experiment With Aspect Ratio as a Means of Extending the Useful Range of a Transonic Inlet Stage of an Axial Flow Compressor
Authors: Swan W. C.
Published: January 2012

An experiment in unstalled range of a transonic axial flow compressor stage is discussed. Two rotors of identical design, but of differing aspect ratio, are compared. The study suggests that some criteria other than blade chord Reynolds number be used to define chord lengths of transonic stages.
Low Reynolds-Number Experiments in an Axial-Flow Turbomachine
Authors: Neustein J.
Published: January 2012

The performance of a single-stage, axial-flow turbomachine was studied experimentally at low Reynolds numbers. The study was made with a turbomachine modeled from a large jet-engine type of axial-flow compressor. Low Reynolds numbers were obtained by using a mixture of glycerine and water as the working fluid. The overall performance was determined over a range of Reynolds numbers RT (based on rotor-tip speed and rotor chord) from 2000 to 150,000. The flow rate at each Reynolds number was varied from near shutoff to the maximum permitted by the turbomachine-tunnel systems. Blade-row characteristics were studied by means of quantitative flow surveys before and after each blade row, and by means of extensive flow-visualization experiments within each blade row. The investigation established that sudden or critical changes in performance do not occur in the type of machine tested, between RT of 150,000 and 20,000. Below 20,000 the performance deteriorated more rapidly. A relatively sharp change in performance occurred between RT of 20,000 and 10,000. The results clarified many of the viscous flow details in each blade row which are associated with the deterioration of performance. These effects were very pronounced at RT of 4000 and below. Consequently, a considerable part of the paper is concerned with results obtained at these lower Reynolds numbers. From the point of view of a designer, information is presented in regard to overall performance, guide-vane turning, and guide-vane and stator total-pressure losses, all as functions of Reynolds number. These results are expected to be indicative of performance in turbomachines similar to the one tested here. Other details are concerned with problems such as wall boundary layers, flow reversal at low flow coefficients, lip-clearance flow, flow patterns near shutoff, and flow comparisons in stators with rotating and stationary hubs.
Study of NASA and NACA Single-Stage Axial Flow Turbine Performance as Related to Reynolds Number and Geometry
Authors: Holeski D. E. , Stewart W. L.
Published: January 2012

This paper presents the results of a study conducted in two parts based on results of NASA and NACA single-stage turbine investigations. The first part was a survey of experimental turbine investigations that were conducted over a range of Reynolds numbers, and the second part was a study of turbine loss as related to geometry. In the first part of the study the turbines investigated covered a range of Reynolds numbers from 104 to 2 × 106, where Reynolds number is defined as the ratio of weight flow to the product of viscosity and rotor radius at the mean section of the blades. In this phase of the study an attempt was made to correlate a basic turbine loss parameter with Reynolds number with the result being that a correlation could not be made. One of these turbines, however, did show a large change in performance with Reynolds number. A second study of turbine loss as related to geometry was then made. For this part of the study, data from additional turbine investigations were used. As a result, the stator throat area seemed to correlate with the loss parameter for the majority of the turbines investigated. An expression was obtained that related the loss parameter with the stator throat area.
Removal of Sulfur Oxides From Flue Gas With Alkalized Alumina at Elevated Temperatures
Authors: Bienstock D. , Field J. H. , Myers J. G.
Published: January 2012

A cyclic process is described for removing the oxides of sulfur from flue gas by absorption at 625 deg F and then converting the oxides to elemental sulfur by reduction of the spent absorbent. Pilot-plant experiments are reported in which a solid absorbent of alkalized alumina in free and baffled fall is used to remove SO2 and SO3 from the combustion gas of a pulverized-cool-fired furnace. The absorbent is then regenerated by heating with hydrogen or with steam-reformed natural gas. Flyash does not interfere and attrition is negligible.
Flexibility Analysis of Three-Dimensional Pipeline Networks
Authors: Michalos James , Grossfield Bernard
Published: January 2012

This paper presents methods of analysis for single-branch and multibranch piping systems undergoing temperature change. The branches may occupy any position in space and the joints may be free to translate in any direction. Illustrative examples are completely worked out for both planar and three-dimensional systems, including branches with portions which are skewed with respect to any system of orthogonal planes.
High Performance Low Pressure Turbine Elements
Authors: Brown R. O. , Heinze F. J. , Davids J.
Published: January 2012

An investigation and evaluation of low pressure turbine-exhaust blading is presented. The chronological development of redesigned stationary and rotating blading is described. Comparisons are presented which indicate the improvement in overall turbine performance owing to blading-design modifications and the development of improved low pressure exhaust casings.
Design of Vessels for Petroleum Refining and Petrochemicals Services
Authors: Clarke J. S. , Northup M. S.
Published: January 2012

A company which operates worldwide in the field of petroleum and petrochemicals finds it necessary to establish practices for pressure vessel design which are uniform and have a sound technical basis. This paper outlines certain design practices of the authors’ company related to critical problems. These problems are brittle of vessels which operate at atmospheric and lower temperatures, efficient utilization of materials for vessels in intermediate temperature service, and the validity of design stresses for vessels which operate at high temperature. The paper emphasizes the need for better high-temperature stress data and for a confirmed method of determining service life expenditure for vessels operating under creep conditions.
Practical Considerations in Applying Laboratory Fracture Test Criteria to the Fracture-Safe Design of Pressure Vessels
Authors: Pellini W. S. , Puzak P. P.
Published: January 2012

Trends in pressure vessel applications involving higher pressures, lower service temperatures, thicker walls, new materials, and cyclic loading require the development of new bases in the supporting scientific and technological areas. This report presents a “broad look” analysis of the opportunities to apply new scientific approaches to fracture-safe design in pressure vessels and of the new problems that have arisen in connection with the utilization of higher-strength steels. These opportunities follow from the development of the fracture analysis diagram which depicts the relationships of flaw size and stress level for fracture in the transition range of steels which have well-defined transition temperature features. The reference criteria for the use of the fracture analysis diagram is the NDT temperature of the steel, as determined directly by the drop-weight test or indirectly by correlation with the Charpy V test. Potential difficulties in the correlation use of the Charpy V test are deduced to require engineering interpretation of Charpy V test data rather than to involve basic barriers to the use of the test. The rapid extension of pressure vessel fabrication to Q&T steels is expected to provide new problems of fracture-safe design. These derive from the susceptibilities of steels within this family to tear fractures of low energy absorption. This fracture mode does not involve a transition temperature and is therefore relatively independent of temperature. It is emphasized that such susceptibilities are not inherent to the family of Q&T steels of low and intermediate strength levels, but are related to specific metallurgical conditions of the plate and particularly the HAZ (heat-affected-zone) regions of Q&T steel weldments.
Theoretical Method for Determining the Apparent Radiation Properties for Materials in Sinusoidal Configuration
Authors: Farber Erich A. , Valandani P.
Published: January 2012

This paper gives a theoretical method by which the apparent radiation properties, absorptance and transmittance, and reflectance can be determined knowing the respective flat material properties. This paper uses a similar approach but is mathematically different from a paper presented at the 1963 Solar Energy Symposium, where a rectangular configuration was the basis for analysis.
Nucleation Characteristics of Static Liquid Nitrogen and Liquid Hydrogen
Authors: Hord Jesse , Jacobs R. B. , Robinson C. C. , Sparks L. L.
Published: January 2012

Characteristics which control the existence of metastable (superheated) liquid states and the nucleation of the vapor phase have been studied; knowledge of these characteristics will assist in the prediction of cavitation in hydraulic equipment. The liquids were superheated by reducing the ullage pressure in a vessel of liquid which was initially in thermodynamic equilibrium. Experimental superheat limit curves for liquid nitrogen and liquid hydrogen, statically contained in a nearly ideal (acid cleaned, smooth glass) system, are presented and compared with theoretical limit curves. The effects of some nonideal liquid-solid interfaces on the nucleation characteristics have been studied and are also included. The theory developed in the text is in fair agreement with the experimental data for the nearly ideal system. Persistence of the metastable state is shown to be dependent upon the rate of pressure decay, the initial equilibrium pressure, fluid environment, and the nucleation pressure. Appreciable superheat persisted for long times with liquid nitrogen (e.g., 44.2 psi superheat persisted for 4.3 sec at 90 deg K) while the persistence times for liquid hydrogen were much shorter (e.g., 48.7 psi superheat persisted for only 0.030 sec at 26.7 deg K).
Blast-Wave Propagation in Hydraulic Conduits
Authors: Lieberman P.
Published: January 2012

The problem of isolating a water pipe system from the effects of a long duration blast wave resulting from a nuclear explosion is discussed. For an impact load of constant amplitude, the load at the end of the pipe has twice the magnitude of the impact load at the entrance of the pipe and has a duration dependent upon the pipe length. However, certain blasts have pressure-time histories which can induce even higher reflection factors than the usual factor of 2. These pressure-time histories, acting upon a water column in a closed-ended pipe, are analyzed by a time-position wave diagram.
Development of a Special High-Efficiency Turbocharger Compressor for Application on Straight Turbocharged Two-Cycle Engines
Authors: Niemczewski T.
Published: January 2012

Conversion of the two-cycle engine from the “in-series” system of turbocharging (turbo-charger followed by the engine-driven centrifugal blower) to a straight turbocharged one, requires a radical increase in the aerodynamic performance of the turbocharger compressor. This paper describes how a wide-range, high-efficiency blower was developed within a relatively short time by using, as a chief design guide, conclusions of the aerodynamic analysis which preceded each development stage. A method is presented, advocating the use of a well-controlled velocity-diffusion system, as compared with a plenum-chamber configuration.
Effects of Operational Parameters on a Large “V” Angle Compressor Engine
Authors: Dorton G. A. , Schaub F. S.
Published: January 2012

This paper investigates the design and performance of the V-250 engine with respect to thermal loading, engine speed, pressure, airflow, ignition timing, and manifold temperature. Detailed test data are presented, and combustion chamber surface and sub-surface temperatures are determined as a function of the many operating variables.
Advanced Lubricating Oil Reduces Gas Engine Maintenance Costs
Authors: Ridgway R. S.
Published: January 2012

Development of lubricating oils which would permit extended periods between major overhauls on natural gas fueled engines has lagged. Over the past several years a new oil has been developed which extends the overhaul period to twice that required by previous oils. The resulting reduction in maintenance costs for various types of engines is studied.
Combustibles Versus Nitrogen Fixation in Gas Engine Operation and Lubrication
Authors: Mastin R. G.
Published: January 2012

Nitration is preferable to combustibles in the operation of the gas engine because it affects only the lubricating oil. Combustibles affect, in addition to lubricating oil, engine parts by the deposition of carbon, and cause expensive fuel waste. The data were gathered with the aid of an exhaust gas analyzer and a spectrophotometer.
Electron-Microprobe Study of Scale Formations on Cr-Mo Superheater Tubing After Long-Time Exposure to 2000 Psi Steam of 1100 F and 1200 F
Authors: Eberle F. , McCall J. L.
Published: January 2012

Metallographically polished sections through the steam-scaled inside surface of 2-in-od × 0.50-in-wall superheater tubing used in ASME High Temperature Steam Research Tests were subjected to electron-microprobe analyses and the concentrations of iron, manganese, silicon, chromium, and molybdenum determined at intervals of 8 to 15 microns (0.3 to 0.6 mil) across the scale thicknesses and in the adjacent tube metal. The relationships between base-metal composition, scale composition, and scale thickness were examined as a function of temperature and time of exposure. The suitability and value of the electron-microprobe as a research tool for studying mechanisms of scaling behavior and scale formations are outlined.
Low-Excess-Air Combustion of Heavy Fuel—High-Temperature Deposits and Corrosion
Authors: Chaikivsky M. , Siegmund C. W.
Published: January 2012

Considerable interest has been shown lately in the operation of oil-fired boilers at minimum excess-air levels to minimize superheater deposits and air-preheater corrosion. This paper presents the results of rig-scale studies which were aimed at determining the extent of the benefits to be derived from the low-excess-air technique. These studies showed the effect of low excess air on SO3 and nitrogen-oxide contents of the flue gas, on the rate of slag deposition on superheater tubes, and on the rate of corrosion of superheater tubes. The level of excess air necessary to obtain these benefits was also determined.
Experimental Investigation of a Magnetically Balanced Arc in a Transverse Argon Flow
Authors: Myers T. W. , McKinnon C. N. , Lysen J. C.
Published: January 2012

An experimental study of an electric arc in crossed convective and magnetic fields has been made. An electric arc was established across a rectangular test section through which argon gas was flowing at approximately atmospheric pressure and velocities up to 100 m/sec. Magnetic field strengths up to 3 webers/m2, oriented so that the Lorentz force opposed the convective force on the arc, were applied perpendicular to both the arc and the direction of the argon gas flow. The test apparatus and the procedure used to obtain the experimental relationship between the velocity of the argon flow and the balancing magnetic field are described. An analysis which assumed the magnetically balanced arc to be a gaseous cylinder positioned between the electrodes and with a diameter varying directly as the arc current satisfactorily explained the observed dependence of the balancing magnetic field on the gas velocity.
Slag-Coal Interface Phenomena
Authors: Raask E.
Published: January 2012

In a cyclone system of combustion or gasification with molten-slag removal a large proportion of the coal is thrown to the slag-coated cyclone walls before it has time to burn. The welting properties of coal-ash slag on devolatilized coal, the evolution of gases from molten slag when in contact with coal particles, and the effect of mineral matter on combustion of coal have been investigated briefly using a heating microscope. Coal-ash slag does not wet coal or coal residues, thus combustion of the coal particles on the surface of molten slag is not retarded. Evolution of gases lakes place from the slag (a) on its initial melting with release of sulfur oxides, and above 1400 C where carbon monoxide is given off when the slag is in contact with coal. The latter is explained in terms of the formation of iron carbide at the slug/carbon interface, the carbide then diffuses into the slag where it reads with silica.
Development of the General Electric LM 1500 Gas Turbine as a Marine Power Plant
Authors: Stoeckly E. E.
Published: January 2012

Many unique advantages have stemmed from the use of aircraft-type gas turbine power plants in selected marine propulsion applications; and, as expected, special problems have arisen because of the marine environment, primarily in the areas of parts integrity resulting from cold and hot corrosion and performance deterioration due to compressor fouling. Sulfur in the fuel, together with sea salt in the fuel and combustion air, creates major problems. Programs directed to reduce the detrimental effects, and the results attained are described.
Supersonic Cascade Tunnel Used to Evaluate Compressor Blade Performance
Authors: Stubner A. W. , Case L. F. , Blake T. R.
Published: January 2012

Large improvements in specific fuel consumption and weight have been achieved during the development of the aircraft gas turbine engine in the past decade. The turbo-machinery requirements have become more demanding during this period, resulting in a significant increase in relative Mach number and diffusion loading in fan and compressor stages. Considerable effort was devoted to develop design systems for this type of turbomachinery, in which relative supersonic inlet velocities are realized for rotor and stator blades. One of the major requirements was to develop a design system for the selection of supersonic blade elements which are required for fan and compressor stages employed in turbofan engines. Since subsonic blade selection design systems are based primarily on empirical relationships which are derived from two-dimensional cascade data, a two-dimensional cascade tunnel was developed for: (a) the investigation of supersonic cascade aerodynamics; (b) the development of high performance supersonic blade elements; and (c) the production of basic supersonic cascade data, which is required for the extrapolation of current subsonic design systems. The present paper describes this facility, presents some typical data, and discusses some of the results obtained.
Chlorination of Sea Water—Effects on Fouling and Corrosion
Authors: Anderson D. B. , Richards B. R.
Published: January 2012

This paper contains a review of literature, field experience, and test data concerning control of fouling by chlorination and temperature and the effects of water treatments on metallic corrosion.
The Prospects for Nuclear Reactor-MHD Commercial Power Production
Authors: Booth L. A.
Published: January 2012

Cycle analysis and preliminary component designs are made for prospective nuclear reactor-MHD commercial power plants, and the problems associated with component development are discussed. The concept of commercial MHD power production is compared with other nuclear reactor power plants, and recommendations are made as to the feasibility of the MHD concept. The results of the study, conducted by an ad hoc committee of staff members at the Los Alamos Scientific laboratory, indicate that nuclear reactor-MHD power production is not feasible for the foreseeable future. The development of major components for MHD plants would require extensive programs, and this cannot be justified in view of the presently undefined criteria. Moreover, no significant gains in power economy can be predicted that will allow the nuclear-MHD plant to compete with more conventional nuclear power plants.
Determination of Noncovalent Docking by Infrared Spectroscopy of Cold Gas-Phase Complexes
Authors: Garand Etienne , Kamrath Michael Z. , Jordan Peter A. , Wolk Arron B. , Leavitt Christopher M. , McCoy Anne B. , Miller Scott J. , Johnson Mark A.
Published: January 2012

Ties That Bind

Almost by definition, effective catalysts bind their substrates for a very short time—releasing them quickly after helping them react and then moving on to bind new, as yet unreacted, substrates. This property engenders an efficient cycle, but it hinders study of the binding motif.

Garand
et al.

(p.
694
, published online 19 January; see the Perspective by

Zwier

) devised a technique to extract bound complexes from solution and freeze their conformations in cold, gas-phase clusters. Probing these clusters by vibrational spectroscopy in conjunction with theoretical calculations then allowed the sites of hydrogen bonding that hold the complexes together to be pinpointed.
H5N1 Debates: Hung Up on the Wrong Questions
Authors: Perez Daniel R.
Published: January 2012

Information related to influenza transmissibility should be published in its entirety.
Owner survey of tarsocrural effusion (bog spavin) in Clydesdale horses
Authors: Weaver M. P. , Wilant L.
Published: January 2012

A postal survey of the owners of Clydesdale horses in the UK and USA was conducted to obtain information on tarsocrural effusion (‘bog spavin’) as an indicator of osteochondrosis from 935 horses. Additional information requested included details of how this condition was investigated and treated. The reported tarsocrural effusion incidence was 10 per cent. The majority of respondents believed the condition to be of concern to Clydesdale owners, but only a minority were aware of the implications of tarsocrural effusion, suggesting that owner education would be of benefit.
GRAVITATIONAL QUANTUM STATES OF NEUTRONS AND THE NEW GRANIT SPECTROMETER
Authors:   On behalf of the GRANIT Collaboration, NESVIZHEVSKY V. V.
Published: January 2012

The review covers recent developments on gravitational quantum states of neutrons and the new GRANIT spectrometer, discussed during the Workshop GRANIT-2010 in Les Houches.1The GRANIT facility2includes the spectrometer and the infrastructure needed for its operation. It is constructed at Institut Laue-Langevin (ILL)3in Grenoble for studies of/with gravitational quantum states of neutrons, and for related topics. New methodical developments4are discussed for future upgrades of this facility. An important motivation for this activity consists in constraining fundamental short-range forces.5Other quantum phenomena in gravitational field,6and centrifugal quantum states of neutrons,7were discussed as well. A detailed presentation of all these topics could be found in Workshop-2010 presentations.8We will focus here on instrumental developments and on options for studying neutron gravitational states.