bluuebunny/crossref_metadata_2025 huggingface dataset:
Handheld fluorescence imaging device detects subclinical wound infection in an asymptomatic patient with chronic diabetic foot ulcer: a case report
Authors: Wu Yichao C , Smith Marlie , Chu Ashley , Lindvere‐Teene Liis , Starr Danielle , Tapang Kim , Shekhman Rachel , Wong Olive , Linden Ron , DaCosta Ralph S
Published: April 2015

Chronic wounds are a significant burden to global patient and health care infrastructures, and there is a need for better methods of early wound diagnosis and treatment. Traditional diagnosis of chronic wound infection by pathogenic bacteria, using clinical signs and symptoms, is based on visual inspection under white light and microbiological sampling (e.g. swabbing and/or biopsy) of the wound, which are subjective and suboptimal. Diagnosing microbial infection based on traditional clinical signs and symptoms in wounds of asymptomatic patients is especially challenging at the bedside. Bacteria are invisible to the unaided eye and wound sampling for diagnostic testing can cause unacceptable delays in diagnosis and treatment. To address this problem, we developed a new prototype handheld, portable fluorescence imaging device that enables non‐contact, real‐time, high‐resolution visualisation of pathogenic bacteria and tissues in wounds. Herein, we report the clinical use of this imaging device in detecting subsurface heavy bacterial load and subclinical local infection in an asymptomatic 50‐year‐old patient with a non‐healing diabetic foot ulcer.
Subfactors of oppositional defiant disorder: converging evidence from structural and latent class analyses
Authors: Herzhoff Kathrin , Tackett Jennifer L.
Published: April 2015

Background

Structural models of oppositional defiant disorder (ODD) symptoms have gained empirical support but await greater empirical scrutiny on issues such as reconciliation between competing models, evidence for gender differences, and delineation of external correlates. More extensive validation evidence is particularly necessary in consideration of their incorporation in psychiatric nomenclature.

Methods

We fitted previously proposed, but competing, models to ODD symptoms assessed with the Computerized Diagnostic Interview Schedule for Children (Shaffer et al., 2000, J. Am. Acad. Child Adolesc. Psychiatry, 39, 28) in a community sample and then fitted the best‐fitting model in a replication sample (combined N = 730, Mage = 9.89, SD = 0.75). Analyses also examined potential classes based on resulting subfactors, gender differences, longitudinal associations with later behavioral problems, and concurrent personality associations.

Results

Burke's (2010) two‐factor model composed of Irritability and Oppositionality subfactors best fit the data. Irritability and Oppositionality showed convergent and divergent patterns of association with personality traits at T1 and with externalizing and internalizing problems at T2. Latent class analyses revealed three classes (low severity, irritable/combined, and oppositional) which showed parallel divergence in externalizing and internalizing problem comorbidity. These findings were largely robust across gender and samples.

Conclusions

These findings support Irritability/Oppositionality subfactors of ODD in two mixed‐gender samples, demonstrate strong evidence for a lack of gender differences in such subfactors, and demonstrate their convergent and divergent validity in emergent latent classes, later behavioral problems, and personality correlates.
DETECTION OF MALNUTRITION IN PATIENTS UNDERGOING MAINTENANCE HAEMODIALYSIS: A QUANTITATIVE DATA ANALYSIS ON 12 PARAMETERS
Authors: Nafzger Sonja , Fleury Lea‐Angelica , Uehlinger Dominik E. , Plüss Petra , Scura Ninetta , Kurmann Silvia
Published: April 2015

Background

Protein‐energy‐malnutrition (PEM) is common in people with end stage kidney disease (ESKD) undergoing maintenance haemodialysis (MHD) and correlates strongly with mortality. To this day, there is no gold standard for detecting PEM in patients on MHD.

Aim of Study

The aim of this study was to evaluate if Nutritional Risk Screening 2002 (NRS‐2002), handgrip strength measurement, mid‐upper arm muscle area (MUAMA), triceps skin fold measurement (TSF), serum albumin, normalised protein catabolic rate (nPCR), Kt/V and eKt/V, dry body weight, body mass index (BMI), age and time since start on MHD are relevant for assessing PEM in patients on MHD.

Methods

The predictive value of the selected parameters on mortality and mortality or weight loss of more than 5% was assessed. Quantitative data analysis of the 12 parameters in the same patients on MHD in autumn 2009 (n = 64) and spring 2011 (n = 40) with paired statistical analysis and multivariate logistic regression analysis was performed.

Results

Paired data analysis showed significant reduction of dry body weight, BMI and nPCR. Kt/Vtot did not change, eKt/v and hand grip strength measurements were significantly higher in spring 2011. No changes were detected in TSF, serum albumin, NRS‐2002 and MUAMA. Serum albumin was shown to be the only predictor of death and of the combined endpoint “death or weight loss of more than 5%”.

Conclusion

We now screen patients biannually for serum albumin, nPCR, Kt/V, handgrip measurement of the shunt‐free arm, dry body weight, age and time since initiation of MHD.
Complexity Analysis of Beat‐to‐Beat Skin‐Surface Laser‐Doppler Flowmetry Signals in Stroke Patients
Authors: Chen Chao‐Tsung , Hsiu Hsin , Fan Jin‐Shiang , Lin Fong‐Cheng , Liu Yen‐Ting
Published: April 2015

Objectives

This study performed skin‐surface LDF measurements and SampEn analysis with the aims of (i) capturing the temporal complexity of cerebral hemodynamics in stroke patients and (ii) discriminating stroke patients from healthy control subjects. We also investigated the response induced by AS in beat‐to‐beat SampEn indexes of LDF signals.

Methods

LDF signals were obtained at bilateral TaiYang acupoints in 52 stroke patients. Each assessment involved a 20‐minute baseline recording, a 20‐minute AS, and a subsequent 20‐minute recording. The FDT, FRT, and PW were calculated for each pulse of the LDF signals, and then their SampEn values were calculated.

Results

The SampEn values of FRT were significantly larger in the stroke group (1.064 ± 0.052 and p = 0.013 at the stroke side; 1.059 ± 0.055 and p = 0.017 at the controlateral side) than in the control group (0.975 ± 0.120). On the stroke side, the SampEn of value of FRT was significantly decreased following AS (1.064 ± 0.052 to 1.008 ± 0.060; p = 0.027).

Conclusion

Larger SampEn values of FRT can be partly attributed to the local regulatory activities that are present in the stroke subjects when facing the induced abnormal vascular conditions and blood flow perfusion resistance. The present findings could aid the development of a noninvasive monitoring technique that will enable discrimination of the different microcirculatory responses in stroke patients.
Increased expression of six ZIP family genes by zinc (Zn) deficiency is associated with enhanced uptake and root‐to‐shoot translocation of Zn in barley (Hordeum vulgare)
Authors: Tiong Jingwen , McDonald Glenn , Genc Yusuf , Shirley Neil , Langridge Peter , Huang Chun Y.
Published: April 2015

Low zinc (Zn) in soils reduces yield and grain Zn content. Regulation of ZRT/IRT‐like protein (ZIP) family genes is a major mechanism in plant adaptation to low and fluctuating Zn in soil. Although several Zn deficiency‐inducible ZIP genes are identified in cereals, there has been no systematic study on the association of Zn deficiency‐induced uptake and root‐to‐shoot translocation with expression of ZIP family genes.

We measured Zn deficiency‐induced uptake and root‐to‐shoot translocation of Zn in barley (Hordeum vulgare) plants by resupplying 0.5 μM Zn, and quantified the transcripts of thirteen HvZIP genes. Subcellular localization and tissue‐specific expression were also determined for Zn deficiency‐inducible HvZIP genes.

Zn deficiency enhanced the capacity of uptake and root‐to‐shoot translocation of Zn, and sustained the enhanced capacity for 6 d after Zn resupply. Six HvZIP genes were highly induced in roots of Zn‐deficient plants, and their proteins were localized in the plasma membrane. Tissue‐specific expression in roots supports their roles in uptake and root‐to‐shoot translocation of Zn under low Zn conditions.

Our results provide a comprehensive view on the physiological roles of ZIP genes in plant adaptation to low and fluctuating Zn in soil, and pave the way for development of new strategies to improve Zn‐deficiency tolerance and biofortification in cereals.
Fasting and bed rest, even for a relatively short period, are risk factors for ceftriaxone‐associated pseudolitiasis
Authors: Murata Shinya , Aomatsu Tomoki , Yoden Atsushi , Tamai Hiroshi
Published: April 2015

Background

Cholelithiasis is one of the side‐effects of ceftriaxone (CTRX). Reportedly, the cholelithiasis resolves relatively soon after cessation of CTRX, hence, it is called pseudolithiasis. Previous reports have suggested that biliary pseudolithiasis can cause not only gallstone attacks, but also severe adverse events, such as cholecystitis and pancreatitis. The purpose of this study was to prospectively elucidate the risk factors and clinical features of CTRX‐associated pseudolithiasis in pediatric patients.

Methods

We prospectively examined the incidence and clinical outcome of CTRX‐associated biliary pseudolithiasis. Subjects included infants and children who were admitted to hospital with acute disease. Ultrasonography was used to confirm the absence of stones and sludge in the gallbladder before CTRX therapy, and in assessment of pseudolithiasis on days 3, 5, 7 and 10 after initiation of CTRX in all subjects. The pseudolithiasis group was then compared with the non‐pseudolithiasis group in terms of age, sex, CTRX dose, CTRX duration, duration of fever, fasting period, period of bed rest, and blood test results.

Results

Sixty patients were enrolled in the study. Eleven of them had biliary pseudolithiasis on ultrasonography (18.3%). Formation of biliary pseudolithiasis was prevalent in the fasting and bed rest groups, appearing relatively early in these groups.

Conclusions

Special attention should be paid to the degree of oral intake and patient activity when CTRX is prescribed. We recommend regular ultrasonographic follow up of patients receiving CTRX, to evaluate the formation of biliary pseudolithiasis.
Why do we Suffer? Buddhism and the Problem of Evil
Authors: Gäb Sebastian
Published: April 2015

This paper explains the Buddhist concept of suffering (dukkha) and its relation to the Christian problem of evil. Although there is no problem of evil in Buddhism, the Buddhist understanding of the origin and causes of suffering will help us to find new approaches to the problem of evil. More specifically, I argue (1) that the concept of evil can be interpreted in terms of dukkha; (2) that the existence of suffering or dukkha is necessarily inevitable for finite beings, given the metaphysical structure of the world and ourselves; and (3) that this reasoning can be interpreted as a defense against the problem of evil.
Dissemination of Plasmodiophora brassicae in livestock manure detected by qPCR
Authors: Chai A. L. , Li J. P. , Xie X. W. , Shi Y. X. , Li B. J.
Published: April 2015

The present study was performed to investigate whether Plasmodiophora brassicae can be disseminated by livestock manure. A quantitative PCR (qPCR) assay was developed and used to detect and quantify P. brassicae in manure samples from naturally and artificially infested chickens and pigs. In naturally infested manure, quantifiable levels of infestation were observed in 7 out of the 28 samples, ranging from 103 to 107 resting spores per g of manure. The vast majority of the resting spores (76–91%) were viable, as determined by a dual fluorescence viability assay. Clubroot symptoms developed on plants inoculated with P. brassicae resting spores isolated from all seven qPCR‐positive samples. Artificially infested manure samples were produced by feeding chickens and pigs on P. brassicae‐contaminated feed. The levels of infestation were 103 resting spores per g of manure for both chicken and pig manure sampled 24 and 48 h after feeding, respectively. Spore viability was >80% for both samples, and the disease severity indices were both >40 as indicated by bioassay. This showed that resting spores can survive the digestive tracts of chickens and pigs, and retain strong pathogenicity. The findings indicate that manure dissemination is possible for P. brassicae. Farmers should avoid feeding livestock on P. brassicae‐contaminated feed or applying infested manure as fertilizer on land intended for crucifer crops.
Anti‐microbial Use in Animals: How to Assess the Trade‐offs
Authors: Rushton J.
Published: April 2015

Antimicrobials are widely used in preventive and curative medicine in animals. Benefits from curative use are clear – it allows sick animals to be healthy with a gain in human welfare. The case for preventive use of antimicrobials is less clear cut with debates on the value of antimicrobials as growth promoters in the intensive livestock industries. The possible benefits from the use of antimicrobials need to be balanced against their cost and the increased risk of emergence of resistance due to their use in animals. The study examines the importance of animals in society and how the role and management of animals is changing including the use of antimicrobials. It proposes an economic framework to assess the trade‐offs of anti‐microbial use and examines the current level of data collection and analysis of these trade‐offs. An exploratory review identifies a number of weaknesses. Rarely are we consistent in the frameworks applied to the economic assessment anti‐microbial use in animals, which may well be due to gaps in data or the prejudices of the analysts. There is a need for more careful data collection that would allow information on (i) which species and production systems antimicrobials are used in, (ii) what active substance of antimicrobials and the application method and (iii) what dosage rates. The species need to include companion animals as well as the farmed animals as it is still not known how important direct versus indirect spread of resistance to humans is. In addition, research is needed on pricing antimicrobials used in animals to ensure that prices reflect production and marketing costs, the fixed costs of anti‐microbial development and the externalities of resistance emergence. Overall, much work is needed to provide greater guidance to policy, and such work should be informed by rigorous data collection and analysis systems.
First Report on the Efficiency of Oral Vaccination of Foxes against Rabies in Serbia
Authors: Lupulovic D. , Maksimovic Zoric J. , Vaskovic N. , Bugarski D. , Plavsic B. , Ivanovic N. , Petrovic T. , Pusic I. , Marcic D. , Grgic Z. , Lazic S.
Published: April 2015

Rabies is one of the oldest known zoonotic diseases that has significant impact on public health, but still remains neglected in Serbia. Rabies virus can infect humans and other mammals and causes inflammation of the brain associated with encephalomyelitis and neurological symptoms. In 2010, Veterinary Directorate (national Competent Authority for animal health in Serbia) has started multi‐annual project of oral rabies vaccination of foxes and other wild carnivores (e.g. jackals), as support of long‐term programme of eradication of rabies in Serbia, co‐funded by EU (financed by Instrument for Pre‐Accession Assistance). Monitoring of the effectiveness of oral vaccination campaigns has been carried out in continuation from 2011 and was based on: (i) post‐mortem laboratory examination of brain tissue of target animals (foxes, jackals and other carnivores) by fluorescent antibody test (FAT), (ii) detection of antibodies against rabies virus in serum samples by ELISA and (iii) detection of tetracycline biomarker in the mandibles for the evaluation of vaccine bait uptake. From September 2011 to May 2014, the total number of 4943 brain tissue samples, 4241 sera and 4971 mandibles were analysed. Confirmed rabies‐positive brains decreased from 10 in 2011/2012 to 6 in 2012/2013 and eventually to 1 positive case in 2013/2014. The seroconversion rate increased from 10.48% (133/1269) in 2011/2012 to 20.11% (362/1800) in 2012/2013 and 42.23% (495/1172) in 2013/2014. Along with the seroconversion, the number of detected tetracycline‐positive mandibles demonstrated an increasing tendency in the same period, being 49.67% (682/1373) in 2011/2012, 62.60% (1294/2067) in 2012/2013 and 90.33% (1383/1531) in the monitoring programme carried out in 2013/2014. Presented results confirmed that ORV of foxes and other wildlife in Serbia against rabies was successful and characterized by steady increase of vaccine baits uptake and immunization of animals.
Corporate Shareholding Structure and Dividend Payout Ratio of Listed Chemical and Paints Companies in Nigeria
Authors: Dandago Kabiru Isa , Farouk Musa Adeiza , Muhibudeen Latifat
Published: April 2015

This paper is an empirical analysis of influence of Corporate Shareholdings Structure on Dividend payout ratio of listed Chemical and Paints Companies in Nigeria. The study is for the period of 2008-2013. The listed Chemical and Paints Companies are Eight (8) in number as provided by Nigerian stock exchange factbook for 2013. All the eight firms were used for the study. Corporate Shareholdings Structure was proxy with managerial shareholding, institutional shareholding, block shareholding and foreign shareholdings, while dividend payout ratio was proxy with dividends to net income for the same period. The data were collected from secondary source through the annual reports and accounts of the firm. The study adopted multiple regression technique. The findings revealed that managerial shareholdings has negatively, strongly and significantly impacted on dividend payout ratio of listed Chemical and Paints Companies in Nigeria, while Institutional shareholdings, Foreign shareholdings have positive, strong and significant influence on dividend payout ratio. But block shareholding shows no significant contribution to dividend payout ratio. It is recommended amongst others that the listed Chemical and Paints Companies should increase the number of shares allotted to institutional shareholders and foreign shareholders where investors are only interested in dividend payment as it may serve as a sure means of having increase in payment of dividend to shareholders. But where shareholders are only interested in capital gain rather than dividend payment, the shares held by management should be increased as this will discourage payment of high dividend in favour of capital gain.
Development and Validation of a Musculoskeletal Model of the Fully Articulated Thoracolumbar Spine and Rib Cage
Authors: Bruno Alexander G. , Bouxsein Mary L. , Anderson Dennis E.
Published: April 2015

We developed and validated a fully articulated model of the thoracolumbar spine in opensim that includes the individual vertebrae, ribs, and sternum. To ensure trunk muscles in the model accurately represent muscles in vivo, we used a novel approach to adjust muscle cross-sectional area (CSA) and position using computed tomography (CT) scans of the trunk sampled from a community-based cohort. Model predictions of vertebral compressive loading and trunk muscle tension were highly correlated to previous in vivo measures of intradiscal pressure (IDP), vertebral loading from telemeterized implants and trunk muscle myoelectric activity recorded by electromyography (EMG).
Influences of Exothermic Reactive Layer and Metal Interlayer on Fracture Behavior of Reactively Bonded Solder Joints
Authors: Namazu Takahiro , Ohtani Kohei , Inoue Shozo , Miyake Shugo
Published: April 2015

Reactively bonded solder joints with Al/Ni exothermic films attract much attention in semiconductor and microelectromechanical systems (MEMS) industries. Higher bond strength of the joints is required for long-term mechanical reliability. We have investigated the strength of rectangular-solid single crystal silicon (SCS) specimens with reactively bonded Sn-3.5Ag solder joint by using specially developed four-point bending test equipment. In this paper, the influences of Al/Ni exothermic film thickness and metallic interlayer on the strength are discussed. The strength increases with increasing Al/Ni film thickness and pressure load during bonding. Metallic interlayer between the solder and SCS also affects the strength because fracture origin is dependent on the types of metals. The obtained results suggest that reacted NiAl is durable against external forces compared with the solder and interlayer.
Recent Experimental Results on Gasification and Combustion of Low BTU Gas for Gas Turbines
Authors: Crouch W. B. , Schlinger W. G. , Klapatch R. D. , Vitti G. E.
Published: April 2015

A proposed system is presented for low pollution power generation by means of a combined cycle gas turbine system using low Btu fuel gas produced from high sulfur residual oil and solid fuel. Experimental results and conclusions are presented from a cooperative research program involving Texaco Inc. and Turbo Power and Marine Systems, Inc. whereby high sulfur crude oil residue was partially oxidized with air to produce a 100 to 150 Btu/scf sulfur-free fuel gas for use in a turbine combustor. An FT4 gas turbine combustion chamber test demonstrated that low Btu gas can be efficiently burned with a large reduction in NOx emissions. Gas turbine modifications required to burn low Btu gas are described and projected NOx emission compared to No. 2 fuel oil and natural gas are shown for an FT4 gas turbine. Integration of the gas turbine combined cycle system to a low Btu gasification process is described. The system provides an efficient method of generating electrical power from high sulfur liquid fuels while minimizing emission of air and water pollutants.
Water-Jet Propulsion System Design Studies Using a Computer
Authors: Frith D. A.
Published: April 2015

In the early stages of system design studies it is generally not feasible to generate a formalized design procedure that can be implemented on a computer. Yet such studies can be expedited by causing the computer to carry out those routine calculations that form the basic blocks of the model of the system. This capability can be utilized effectively on a remote-console, time-sharing computer by formulating a program, based essentially on a set of blocks of formalized procedures to carry out these routine calculations, in such a manner that the parameters to be varied and the results to be monitored may be selected during run time. Application of this principle to design studies of a gas turbine driven, water-jet propulsion system for a ship is described and experience with the operation of the program discussed.
Developments in Programmable Analog Control Systems
Authors: Dent J. R. , Bergman G. D.
Published: April 2015

The advantages of programmable control systems for gas turbine engines have been recognized for some time. In the exotic climate of the aerospace industry some progress has been achieved by the use of digital computer control. This approach, however, cannot be justifed on an economic basis for industrial or vehicular applications. A programmable analog control system is described which provides the optimum solution to the twin problems of control capability and low cost. The basic element of this system is an analog computer which is programmed from a stored digital program. This computer performs calculations directly on sensor signals in analog form to provide analog signals that can be used directly to drive the system actuators. This programmable analog computer is described in detail, and an example is given of its application to a practical gas turbine control system. The size, cost, and reliability of the final programmable analog control system is shown to be attractive.
Integrated Propulsion Systems for V/STOL Transports
Authors: Zabinsky J. M. , Carter R. N.
Published: April 2015

The integration of the propulsion system into the design of a vertical/short takeoff and landing (V/STOL) commercial transport for 1985 is presented. On a V/STOL airplane it provides the force for lift and cruise, is the sole source of energy for control, and is powerful enough to handle emergencies including those within the propulsion system itself. The propulsion system concepts all have moderate pressure ratio fans. Some are remotely driven and can be interconnected for power transfer, others have integral fans. The problems of propulsion integration and the conflicting aspects of the various concepts are shown. The considerations of commercial operation lead to limits on noise generation and establish a cruise requirement of M = 0.75. The aircraft size, weight, and cost are the factors by which the designs are compared. The aircraft with integral lift fans and those with shaft-driven fans are particularly attractive; those with gas-driven remote fans are penalized by temperature limitations and the volume of the system.
The Influence of He-Ne, He-N2, and He-CO2 Gas Mixtures on Closed-Cycle Gas Turbines
Authors: Bammert K. , Klein R.
Published: April 2015

With reference to a proposal made by Prof. Ackeret studies have been made on the composition of an optimal working medium for closed-cycle gas turbines. These studies are based on the assumption that this aim could be achieved by mixing helium with a gas of higher molecular weight, using neon, nitrogen, and carbon dioxide here. The influence of these gas mixtures on the circuit parameters and on the layout of the turbomachines and heat exchanging apparatus is shown. The calculations have been carried out giving consideration to the real gas behavior of the mentioned gas mixtures. In addition to this, the relationship of the costs of the turbomachinery and apparatus are shown in relation to a reference plant with pure helium as working agent. The basis for these studies is a process with the thermal efficiency, the upper and lower process temperatures and the turbine inlet pressure being the same for all gas mixtures. The results of the calculations are that, for certain gas compositions, cost advantages can be gained relative to the layout with pure helium. These advantages and the mixture compositions, for which they appear, are dependent on the admixed gases. For these calculations the cost relationship of turbomachines and heat exchangers to the total cost have been considered.
A Model of Two-Dimensional, Incompressible Flow Through a Cascade of Airfoils With Allowance for the Viscous Displacement Effect
Authors: Firth D. A.
Published: April 2015

A model of the potential flow through a cascade of airfoils is developed for which the bounding streamlines are the airfoils plus an allowance for the displacement effect of the boundary layers and wakes. This model has to satisfy two conditions instead of the single one, the Kutta-Joukowski condition, of methods having the airfoils as the bounding streamline of the potential flow. It qualitatively predicts the reduction in lift and the increase in incidence attributed to viscous effects.
Layout and Present Status of the Closed-Cycle Helium Turbine Plant Oberhausen
Authors: Bammert K. , Deuster G.
Published: April 2015

The Oberhausen gas turbine plant now under construction is designed as a fossil-fired heating power station to produce a net electrical output at terminals of 50 MW. Helium as a working medium is employed for the first time in a closed-cycle industrial power plant system. A report is given on the layout of the circuit parameters, on the physical size of the turbomachines and heat exchangers as well as on the design of the gas-fired helium heater. Moreover, the arrangement of circuit components is discussed. The Oberhausen plant was projected under the aspect of a commercial thermal power station. Besides, the plant is of considerable importance concerning the German program for developing high-temperature reactors with helium turbines (HHT). Its significance is, on the one hand, based on the fact that the turbomachines and heat exchangers are constructed in many details to meet the requirements which occur in nuclear helium turbines of high output. Some of these components closely resemble dimensions and stresses as in a HHT-power plant. On the other hand the operational behavior of component parts will be tested under real conditions of a commercial power plant.
A Low-Pollution On-Site, Energy Storage System for Peak-Power Supply
Authors: Shepherd D. G.
Published: April 2015

This paper describes a scheme whereby surplus power during reduced demand periods is used to liquefy air which can be stored and used later to supply peak power with considerably reduced fuel requirements. All the component processes of the system are established techniques, are very largely automatic in operation, and the location is on-site. Such a system can be constructed and placed on-line in a minimum of time and with greatly reduced pollution control requirements. It is capable of considerable flexibility in the use of the liquefied product as air or as the separated constituents as O2 and N2, and thus furnishes a number of ways of optimum utilization as operating conditions and economic circumstances change.
The Constant Volume Gas Turbine: A Thermodynamic Assessment
Authors: Zockel M.
Published: April 2015

A quasi-steady-state analysis is made of the performance of a gas-turbine working with intermittent, constant volume combustion. Variables considered include inlet temperature, compressor pressure ratio, scavenge ratio, combustion time, heat exchanger thermal ratio. Characteristics are computed over a full loading range. Computations are based on turbines having the following behavior: (a) constant turbine efficiency, (b) characteristics of a multistage axial turbine, and (c) characteristics of a single-stage radial turbine. The analysis indicates that the constant volume gas turbine has advantages in thermal efficiency, specific power and part load performance over constant pressure gas turbines operating at the same compressor pressure ratio and turbine inlet temperature. However, the addition of a heat exchanger shows less advantage when applied to a constant volume than to a constant pressure engine.
A New Axial-Radial “Isotherm” Compressor
Authors: Strub R. A.
Published: April 2015

It is known that the compression work of gases can be largely reduced by inter-stage cooling. Multistage radial compressors have been developed in the past with coolers integrated within the casing. Such a solution, however, is limited to medium volume flows of about 40 m3/s. For larger flows, a combination comprising an axial low pressure section with variable guide vanes for flow regulation, used as supercharger, followed by a multistage radial section with integrated coolers, has been developed. The major parameters governing this choice are presented. Aerodynamic tests on the axial and radial sections have been carried out with a special emphasis on the aerodynamic layout of the diffusor connecting the axial or the radial sections to the coolers. The tests have shown that a considerable amount of aerodynamic improvement could be obtained by a proper disposition of asymmetrical guide vanes dividing the total flow going to the coolers placed symmetrically on each side of the casing. Test results on the complete machine, regarding its aerodynamic characteristics and the noise level as well as its mechanical behavior, are given.
Control for 600-Bhp Dump Truck Gas Turbine Engine With Recuperator
Authors: Hiraki H. , Nakao K. , Nakayama T. , Miyamaru T.
Published: April 2015

A fuel control system for a prototype gas turbine with recuperator is described. The electronic fuel control was designed with the aid of a hybrid simulator. Its performance is verified on the bench test for a 600-bhp gas turbine engine with recuperator. Prediction of vehicle behavior and transmission requirements were made for a heavy-duty, 32-ton dump truck equipped wtih the 600-bhp gas turbine engine.
Inspection, Maintenance and Field Repair of Heavy Duty Industrial Gas Turbines
Authors: Hartmann M. , Robben R. , Hoppe P.
Published: April 2015

The expenditures for inspection and maintenance of gas turbines are an important part of the total owning and operating costs. Maintenance outage time should be kept to a minimum. A proper design with adequate ports facilitates visual and boroscope inspection of critical areas. Maintenance outage time can be considerably reduced by special equipment which allows inspection and replacement of bearings and combustor inner parts and balancing of rotors without major disassembly of the unit. The advantages of an indoor installation with overhead crane with respect to maintenance are also discussed in this paper.
Operating Experience of Kongsberg Gas Turbines and Marine Systems on Board Merchant Ships
Authors: Westrum Th.
Published: April 2015

The Kongsberg KG2 gas turbine has been designed specifically as a marine gas turbine for auxiliary drives on board ships. As of October 1973 some 80 engines have been sold for marine applications. The design philosophy of the engine is discussed and a description of the main components of the engine follows. It has been necessary for Kongsberg to develop complete systems for shipowners and shipbuilders. These are described to give an indication of the type of installation in which experience has been gained. The operating experience is discussed. Examples of modifications which have been carried out as a result of this experience are outlined. Attention is drawn to the influence of these modifications on the starting reliability of the engine.
Real-Time Simulation of Jet Engines With Digital Computer
Authors: Nishio Kenji , Sugiyama Nanahisa
Published: April 2015

This paper describes the configuration and some programming techniques of real-time digital simulator of jet engines, along with some comparisons between the simulation test results and actual engine test data. The simulator consists of a mini-computer with memory capacity of 8192 words and an add time of 1.92 μsec, CRT display, A-D, D-A converters and other peripherals. The programming of digital computer is aimed at high flexibility to the change of simulated engine forms and rapid convergence of the matching calculation among engine components.
Low BTU Fuels for Gas Turbines
Authors: Schiefer R. B. , Sullivan D. A.
Published: April 2015

The current shortage of conventional gas turbine fuels has created the need for new sources of “clean” fuel. One of the most promising new fuels is low Btu gaseous fuel, such as produced by air injected coal or oil gasifiers or other chemical processes. The various sources of low Btu fuels and their combustion characteristics are discussed. To burn many of the low Btu fuels in the 100–300 Btu/scf range necessitates certain design modifications to the gas turbine originally optimized for high energy fuels. The extent of the modification depends greatly on the low Btu fuel. The impact of low Btu fuels on the gas turbine thermodynamic cycle performance and environmental performance is very encouraging. From the environmental viewpoint, low Btu fuels promise to be “clean” fuels while providing increased output at higher thermal cycle efficiencies than achieved with conventional fuels.
Training of Industrial Power Plant Personnel Suggested Program
Authors: Fougere L. F.
Published: April 2015

This paper describes a complete training program for an actual industrial plan that generates all of its own 80–90 Mw electrical power load and a great deal of the process steam with gas turbines. Enough information is presented to permit designing a course for most industrial generation and distribution systems including specific and detailed information of material and equipment required.
Turbines and Trained Crews
Authors: Carr J. W. , Kennedy G. R.
Published: April 2015

Equipment knowledgeable operators and maintenance personnel are a valuable asset that will increase Gas Turbine availability and minimize outages and repair costs. A continuing training program is essential to maintain proficiency levels and upgrade new employees. The training program must be properly planned and constructed to accomplish this most effectively.
Operating Experiences With Two Modern Medium Size Gas Turbines
Authors: Thueringer F.
Published: April 2015

The Prototypes of two single-shaft, open-cycle gas turbines, Type 9 and 11, have been put through extensive factory full load test programs before shipment. In the meantime, the first production units have been in commercial operation for a number of thousand of hours with scheduled maintenance already done on some of them. The paper describes some interesting results of factory testing. Furthermore, the performance under normal service conditions will be described as well as reliability and availability.
Gas Turbine Propulsion: An Engineering and Economic Comparison of Mechanical Versus Electric Drive
Authors: Gott Eric , Svensson S. O.
Published: April 2015

This paper discusses mechanical and electric transmissions for the gas turbine propulsion of ships. Various types of transmission arrangements are also described giving their limitations in operational modes and possibilities of supplying auxiliary power. Briefly economical aspects also have been touched upon.
Investigation of Aircraft Gas Turbine Combustor Having Low Mass Emissions
Authors: Troth D. L. , Verdouw A. J. , Williams J. R. , Dodd R. G.
Published: April 2015

This paper describes research on low mass emissions can combustors similar in performance and envelope to the Army T63-A-5A gas turbine engine combustor. The objectives were to develop, using a T63 liner as a, baseline, a combustor having a 50 percent overall reduction in mass emissions (CO, CxHy, NOx and smoke) with no increase in any individual pollutant when tested over a typical Army light observation helicopter (LOH) duty cycle. Initial efforts were directed toward evaluating analytically, using both kinetics and empirical data, the potentials of various emission reduction concepts. Seventeen experimental combustors, each incorporating one or more of the selected concepts, were then designed, fabricated and tested. Experimental results indicated that several concepts had the potential for meeting the program objectives. Two combustors selected for final evaluation were the “Prechamber” and “Modified Conventional.” The low emission feature in the Prechamber combustor is premix/prevaporization. The Modified Conventional combustor incorporates four low emission features: airblast fuel atomization, delayed dilution, convection cooling, and variable geometry. Both of these combustors met the emission reduction objectives. Experimental results indicated that both of these liners can be developed to meet all other conventional T63 combustor requirements i.e., light-off, temperature profile, durability, etc. The estimated development time for the Prechamber is longer than for the Modified Conventional.
A Comparison Between Experimental and Theoretical Fluctuating Lift on Cascades at Low Frequency Parameters
Authors: Satyanarayana B. , Gostelow J. P. , Henderson R. E.
Published: April 2015

A two-dimensional cascade was instrumented with miniature pressure transducers enabling instantaneous pressure distributions to be obtained around one of the blades. The cascade was mounted in a gust tunnel, producing a high quality, sinusoidally oscillating flow onto the blades. The signals were fed into an on-line computer and analyzed to give the instantaneous pressure distributions at different instants in the cycle. The measured fluctuating lift was compared with a vortex singularity theory for different values of space/chord ratio. The agreement was reasonable and, on the basis of these results, certain conclusions have been reached.
A Model of Convex Programming for Turbojet Main Parameter Selection Optimization
Authors: Turcanu C.
Published: April 2015

A mathematical modeling of well-known methods used to define turbojet main parameters aiming at solution optimization is described. The parameters considered include: compression ratio, maximum temperature for turbine, compressor efficiency, turbine efficiency, etc. By using the relationships for specific thrust, specific fuel consumption, etc., and assuming that construction and functional parameters such as calorific value, combustion efficiency, flight altitude and speed, etc., are known a function representing a sum of the ratios describing specific thrust and SFC deviations against maximum specific thrust and minimum SFC, respectively, is derived. Main parameter selection criteria pending on engine operation conditions and aircraft category are introduced. Mathematic analysis for main parameter selection optimization leads to a convex programming model for which both the function and the constraints are convex functions defined by convex fields. Although this paper makes reference to classic jet engines the method may be easily developed for by-pass engines, etc.
Some Results From Tests on a High Work Axial Gas Generator Turbine
Authors: Okapuu U.
Published: April 2015

Aerodynamic test results are presented for a single-stage, axial gas generator turbine of 3.9:1 design pressure ratio. Test results are also shown for a number of variants on this design, indicating the effect on aerodynamic performance of degree of reaction, nozzle and rotor aspect ratio, rotor blade channel design, rotor tip clearance, radial work distribution and effect of nozzle endwall contouring. Detailed aerodynamic observations are compared with analytical predictions. Of the design parameters examined, rotor blade aspect ratio, tip clearance and channel diffusion were found to have the greatest influence on losses. Operation at pressure ratios above the design was found to be improved with “open” rotor stagger, yielding a reduced design point degree of reaction.
Progress in Manufacturing Practices for a Warm-Worked Superalloy
Authors: Coyne J. E. , Couts W. H.
Published: April 2015

A turbine seal disk of Rene 95 is examined as made in a pancake forging, as a closed die forging, and as a forged powder preform. The effect of this progression upon the input weight, manufacturing operations, and NDT is described. The motives that may guide the selection among these varying practices are discussed.
Status Report: Subsonic Aircraft Noise Reduction
Authors: Little J. W. , Russell R. E.
Published: April 2015

The design process for a subsonic commercial transport aircraft is discussed with emphasis on noise considerations. A review of the process for identifying component noise levels is followed by a description of the design for noise reduction of typical components. A discussion of system constraints in the practical application of noise-reduction concepts is followed by comments on the need to include a reasonable design tolerance. Some aspects of the trade between noise reduction and performance are described. Finally, a projection is made of future projected noise reductions based on yet-to-be-accomplished research programs.
Alternate Fuels Capability of Gas Turbines in the Process Industry
Authors: Hefner W. J.
Published: April 2015

As we move into the latter 1970’s and early 1980’s, we can anticipate a period of continuing uncertainty in availability of fuel supplies for the process industry. Even though the overall picture is unclear, there are some aspects of the total problem that are predictable, with a reasonable degree of confidence. One of the developments that can be predicted on the domestic scene is the unavailability of natural gas as an industrial fuel. Short supplies of this resource have significantly limited the installation of new facilities utilizing natural gas as a fuel supply, as well as creating a need to convert existing equipment to use alternate supplies of fuel where uninterruptable sources of natural gas are no longer available. This paper discusses the fuel flexibility of heavy-duty gas turbines and is a status report on the capability of today’s equipment. In addition, techniques for evaluating alternate gas turbine fuels including requirements for cleanliness, combustion properties, physical properties, composition, performance and emissions characteristics, etc., are discussed. Fuels which are covered include: Gasification Process Derived Fuels, By-Product Gases, Distillate Oil, Crude Oil, Residual Oil, Vaporized Liquid Fuels, and Liquefied Coal Products.
Deterministic and Probabilistic Foundation Forces Resulting From an Unbalanced Turbine
Authors: Boyce L. , Kozik T. J.
Published: April 2015

This paper considers the problem of the unbalanced rotating turbine as a single degree of freedom system, wherein the principal mode of vibration is a translation in the direction of the machine supports. The distance from the center of mass of the rotating mass to the geometric axis, also known as the effective eccentricity, is modeled as a random variable. The expression for the root mean square response of the rotating machine is derived and related to the statistical analog for the deterministic expression for the foundation force. These results are numerically compared to their equivalent deterministic values.
Experimental-Analytical Correlation of Optimum Duct Acoustic Liner Performance
Authors: Patterson J. D. , Sawdy D. T. , Beckemeyer R. J.
Published: April 2015

Mode matching and segmented duct analytical models have been developed to take advantage of relative placement of liner segments in the design of optimal duct acoustic liners of one, two, and three segments. This paper presents experimental results which were obtained for liners installed in a rectangular duct for the case with no mean airflow through the duct. Excellent correlation is shown between the analytical and experimental data, thus verifying the analytical procedures used to design the optimum segmented lining configurations.
Ambient Temperature and Pressure Corrections for Aircraft Gas Turbine Idle Pollutant Emissions
Authors: Marzeski J. W. , Blazowski W. S.
Published: April 2015

Recent investigations have indicated that aircraft engine exhaust emissions are sensitive to ambient conditions. This paper reports on combustor rig testing intended to evaluate variations due to ambient temperature and pressure with special emphasis on idle engine operating conditions. Empirically determined CO, CxHy, and NOx correction factors — the ratio of the pollutant emission index value obtained during standard day operation to that resulting during actual ambient conditions — are presented. The effects of engine idle cycle pressure ratio, primary zone fuel-air ratio, and fuel type were investigated. Ambient temperature variations were seen to cause substantial emission changes; correction factors in excess of 2.0 were determined in some cases. Ambient pressure variations were found to be less substantial. A previously published NOx emission model and a simplified hydrocarbon combustion analysis are shown to be in general agreement with the empirical results.