bluuebunny/crossref_metadata_2025 huggingface dataset:
Multi‐institutional retrospective cohort study of patients with severe pulmonary hypertension associated with respiratory diseases
Authors: Tanabe Nobuhiro , Taniguchi Hiroyuki , Tsujino Ichizo , Sakamaki Fumio , Emoto Noriaki , Kimura Hiroshi , Takamura Kei , Hanaoka Masayuki , Nishimura Masaharu , Tatsumi Koichiro ,   JRS Lung Disease PH Study Group
Published: April 2015

Background and objective

Pulmonary hypertension (PH) is often associated with respiratory diseases, but only a small number of patients present with severe PH defined as mean pulmonary arterial pressure ≥ 35 mm Hg. We here conducted a multicenter, retrospective study of patients with severe PH associated with respiratory diseases (R‐PH) to reveal their demographics, treatment, prognosis and determinants of prognosis.

Methods

From 101 patients with severe R‐PH collected by postal survey at the first stage, 70 patients with four major diseases (chronic obstructive pulmonary disease (COPD), combined pulmonary fibrosis with emphysema (CPFE), interstitial pneumonia associated with connective tissue disease (CTD‐IP), interstitial pneumonia (IP)) and normal pulmonary arterial wedge pressure were studied for clinical characteristics, treatment and prognosis.

Results

Three‐year survival rates were 50% for COPD (n = 18), 35.7% for IP (n = 19) and 68.1% for CTD‐IP (n = 20), and the 2‐year survival rate for CPFE (n = 13) was only 22.6%. Eighty‐one per cent of patients had been treated with pharmacotherapy specific for pulmonary arterial hypertension. Those patients who had received phosphodiesterase‐5 inhibitors (PDE‐5I) displayed significantly better survival from the date of diagnosis than those who had not (3‐year survival: 61.8% vs 20.0% P < 0.0001), especially in the IP, CTD‐IP and CPFE groups. Multivariate analysis also revealed that treatment with PDE‐5I was a positive prognostic factor.

Conclusions

We here demonstrated the dismal prognosis of patients with severe R‐PH. The remarkably better survival in those patients who had received PDE‐5I warrants and facilitates future prospective randomized studies in this particular population.
Starker Steuerwettbewerb – starke Reformen? Ein neuer Blick auf Unternehmenssteuerreformen in 15 EU‐Staaten (1998‐2011)
Authors: von Kulessa Alexander , Wenzelburger Georg
Published: April 2015

Obwohl viele europäische Länder ihre Unternehmenssteuern in den vergangenen Jahren gesenkt haben, besteht weiterhin eine beachtliche Varianz im EU‐15‐Vergleich. Der vorliegende Beitrag nimmt diese Unterschiede zum Anlass, um die Frage nach den Bestimmungsgründen der Unternehmenssteuerreformen und deren Ausmaß neu zu stellen. Neu deshalb, weil er eine logistische Panelregression mit einer fsQCA verbindet und damit die bisherigen Studien methodisch‐konzeptionell ergänzt. Und ebenfalls neu deshalb, weil er sich hinsichtlich des Untersuchungszeitraumes auf die Jahre 1998‐2011 beschränkt und damit auf einen Zeitraum, in dem der verschärfte Steuerwettbewerbs in globalisierten Märkten besonders relevant ist. Die Ergebnisse der empirischen Analysen bestätigen den überaus starken Einfluss, welche die Position eines Landes im internationalen Steuerwettbewerb auf dessen Steuerreformtätigkeit ausübt. Sowohl in der fsQCA als auch in der logistischen Panelregression dominiert dieser Zusammenhang. Daneben erlauben die Ergebnisse auch eine Nuancierung bisheriger Befunde zum Einfluss von Vetospielern und Parteipolitik.
Successful transfusion of antigen positive blood to alloimmunised patients using a monocyte monolayer assay
Authors: Noumsi G. T. , Billingsley K. L. , Moulds J. M.
Published: April 2015

Background

Providing adequate transfusion support for alloimmunised patients for whom antigen negative blood is not readily available is hampered by the risk of a haemolytic reaction. The monocyte monolayer assay (MMA) has shown good correlation between the antibody clinical significance and the fate of antigen positive blood.

Materials and Methods

From 2006 to 2013, the clinical significance of red cell alloantibodies produced by 61 patients was evaluated using a MMA; and antigen positive blood offering the best survival advantage was selected for transfusion following a secondary MMA crossmatch. Post‐transfusion, patients were evaluated for clinical signs of haemolysis.

Results

Overall, 19 of 61 (31·1%) of our antibodies were potentially clinically significant, with a monocyte index (MI) > 5%. There was no correlation between the clinical significance as showed by the MMA, and the specificity of the antibody or the strength of reactivity at antihuman globulin (AHG) phase. Using the MMA as a secondary crossmatch method, 31 alloimmunised patients (including: eight anti‐hrB, four anti‐Yta, one each anti‐Rg1, ‐Coa, Era, Leb, ‐LW, ‐Sl1) received 103 antigen positive blood units with no clinical sign of a post‐transfusion reaction. For three patients (one each anti‐Joa, ‐AnWj, unidentified ‘HTLA’), initial MMA was performed as part of an investigation of a suspected haemolytic reaction. In each case, the MMA accurately identified the unit responsible for the reaction.

Conclusion

Used as a crossmatch surrogate, the MMA provided valuable information in the decision of transfusing antigen positive blood to alloimmunised patients, avoiding delay because of the search of rare antigen negative units.
Retrospective analysis of community hospital red blood cell recovery procedures: improved utilization needed for effectiveness
Authors: Bellone Michael , Pham Huy P. , Shaz Beth H. , Shi Patricia A.
Published: April 2015

BACKGROUND

Perioperative blood recovery (PBR) is an important component of patient blood management. We analyzed our experience providing PBR for community hospitals to determine procedure types and clinical variables associated with efficacy and cost‐effectiveness.

STUDY DESIGN AND METHODS

PBR cases (>25,000) from January 2008 through December 2012 were analyzed. For each procedure type, the median number of returned red blood cell units (rRBCs) and ratio of cases with at least 1 to less than 1 rRBC unit were calculated. Clinical predictors of rRBC were identified by linear and logistic regression.

RESULTS

The overall median rRBC was 0.29 units despite median estimated blood loss (EBL) of 350 mL. Only three of 31 common procedure types had ≥1:<1 rRBC ratios near to or higher than 1. In nine of 31 common procedure types, at least 50% of cases had no rRBC return. Linear regression demonstrated significant association of rRBCs with increased EBL, longer operative duration, surgeon, PBR device type (autoLog vs. CS5), and decreasing age. EBL, autoLog use, high surgeon case volume, vascular procedures, and emergent versus elective procedures associated with higher odds of at least 1 rRBC.

CONCLUSION

Discrepancy between rRBC and EBL and high percentages of cases with no rRBC suggests that PBR technique and case selection need optimization. Identification of procedure types and variables associated with PBR efficacy (≥1 rRBC) should improve utilization of PBR. Association of autoLog use with higher rRBC warrants further investigation.
Relative stiffness of 3 bandage/splint constructs for stabilization of equine midmetacarpal fractures
Authors: Lutter John D. , Cary Julie A. , Stephens Robert R. , Potts Logan B.
Published: April 2015

Objective

Determine the relative stiffness of 3 bandage/splint constructs intended for emergency fracture stabilization.

Design

Experimental model. A single plane free end deflection model was developed to simulate the forces placed on a bandage/splint construct during stabilization of a complete mid‐metacarpal bone fracture. The total deflection of the model in one plane was measured following application of 3 different bandage/splint combinations including a classic, 3 layered Robert Jones Bandage (RJB) with a splint placed on the outside of the bandage (RJB‐3), an RJB with splint placed after the first of 3 bandage layers (RJB‐1), and a single layer full limb bandage with external splint (SS). Comparisons were made between the deflections of the model with each bandage/splint combinations in an effort to determine the most effective method for field fracture stabilization.

Setting

Laboratory.

Animals

No animals were utilized in data collection for this study. Two live horses were utilized during the pilot study.

Interventions

Application of bandage and splint to a model intended to simulate the bending force on a lower forelimb fracture in a horse

Measurements and Main Results

Deflection was determined by the difference between the height of the model's supported free end before application of a 4.5 kg weight and at the conclusion of the deflection test. There was no significant difference in the amount of deflection between bandage/splint combinations (78 ± 32 mm (RJB‐1), 94 ± 44 mm (RJB‐3), and 93 ± 33 mm (SS))

Conclusions

The one‐layer bandage with splint was equivalent to either RJB configuration in the mean amount of deflection in the simple model of a fracture.
Assessment of coagulation utilizing thromboelastometry in dogs undergoing orthopedic surgery
Authors: Bruno Barbara , Maurella Cristiana , Falco Sara , Tarducci Alberto , Zanatta Renato , Gianella Paola , D'Angelo Antonio , Piras Lisa , Di Bella Andrea , Borrelli Antonio
Published: April 2015

Objective

To evaluate blood coagulation using thromboelastometry in dogs following orthopedic surgery.

Design

Longitudinal observational study.

Setting

University veterinary teaching hospital.

Animals

Thirty‐four adult client‐owned dogs.

Measurements and Main Results

Dogs undergoing elective or emergency orthopedic surgery had whole blood collected before (T0), at 24 hours (T1), and 1 week (T2) after surgery. Whole blood from each dog was collected by jugular venipuncture using a 20‐Ga needle and minimum venous stasis. The blood was placed into tubes containing 3.8% trisodium citrate (1 part citrate: 9 parts blood) and rested at 37°C. Coagulation was evaluated by means of thromboelastometry using the in‐TEM, ex‐TEM, and fib‐TEM assays. Statistically significant increases (P < 0.05) in maximum clot firmness (MCF) from T0 to T1 in the in‐TEM and fib‐TEM profiles (both P = 0.0001), from T0 to T2 in the in‐TEM, ex‐TEM, and fib‐TEM profiles (P = 0.012, P = 0.037, and P = 0.0001, respectively), and from T1 to T2 in the fib‐TEM profile (P = 0.039) were noted. The α angle increased from T0 to T2 in the in‐TEM and ex‐TEM profiles (P = 0.019 and P = 0.036, respectively). All results were, however, within the institutional reference ranges.

Conclusions

In this study, unlike the hypercoagulability observed in human orthopedic patients, a hypercoagulable state as measured by thromboelastometry did not develop in dogs following orthopedic surgery.
Pain following blood donation: a questionnaire study of long‐term morbidity (LTM) in blood donors
Authors: Sørensen B. S. , Jørgensen J. , Jensen T. S. , Finnerup N. B.
Published: April 2015

Background

Nerve injury is a main cause of long‐term morbidity following blood donation, but little is known about symptoms, impact, prognosis and underlying cause.

Materials and Methods

A questionnaire, designed to characterize pain and estimate the prevalence of neuropathic pain, was sent to all blood donors registered with a complication related to 3 297 674 blood donations in Denmark from 2000–2009, with a local complication mainly characterized by pain, with severity grade ‘long‐term morbidity’ and imputability grade ‘definite’ or ‘probably’.

Results

The questionnaire was sent to 152 donors (4·6 per 100 000 donations). Response rate was 88/152 (57·9%). At the time of the questionnaire, which was between 12 months and 10 years after the blood donation, 69/88, who responded (78·4%) still experienced symptoms. Of the 69 donors with persistent symptom, pain occurred in 51 donors (74%) was moderate to severe in 24/69 donors (35%) and had an impact on daily activity in 17/69 (25%). Neuropathic pain was estimated to be the underlying cause of symptom in 30–52% of the 69 donors with persistent symptoms, using three different systems for estimation, corresponding to 0·6–1·1/100 000 donations.

Discussion

Although a rare complication, nerve injury after blood donation may lead to long‐term morbidity and may become chronic in a small proportion of donors. The most common symptoms are pain, and we estimate that neuropathic pain can be the underlying cause.
Thawed and liquid plasma – what do we know?
Authors: Cardigan R. , Green L.
Published: April 2015

There is increasing interest in the use of liquid or frozen plasma thawed and stored for extended periods (>24 h) to reduce wastage and to improve rapid availability of plasma in massive transfusion protocols advocating the early use of plasma in trauma by some centres. There is now a body of studies that have assessed individual coagulation factors during storage of thawed plasma. These show that factor VIII (FVIII) is the worst affected factor and that its activity is mainly lost during the first 24 h following thawing. However, for most factors studied, there is a continual decline during further storage. The few studies that have assessed thrombin generation in thawed plasma have shown variable results. Extended storage of plasma is associated with an increase in levels of DEHP in the component and could theoretically increase the risk of bacterial contamination, although the latter does not appear to have been an issue in countries that have adopted the use of thawed plasma. There are no clinical studies relating to the efficacy of extended‐thawed plasma, and therefore, the potential reduction in its efficacy must be balanced with the clinical need for the component.
GENDER, WEIGHT, AND AGE EFFECTS ON PREVALENCE OF CAUDAL ABERRANT NASAL TURBINATES IN CLINICALLY HEALTHY ENGLISH BULLDOGS: A COMPUTED TOMOGRAPHIC STUDY AND CLASSIFICATION
Authors: Vilaplana Grosso Federico , Haar Gert Ter , Boroffka Susanne A. E. B.
Published: April 2015

English Bulldogs have been reported to demonstrate abnormal growth and development of the nasal turbinates, which contribute to an increase in airway resistance and hence clinical signs of brachycephalic airway syndrome. The purpose of this prospective, cross‐sectional study was to assess the prevalence and severity of caudal aberrant turbinate protrusion via CT studies of English Bulldogs with, according to the owners, none or minimal clinical signs of brachycephalic airway syndrome. An additional objective was to propose a classification scheme for describing the degree of caudal aberrant turbinate protrusion in English Bulldogs and to apply this scheme in assessing the effect of gender, weight, and age on prevalence and severity of turbinate protrusion. The nasal cavities of 40 clinically healthy English Bulldogs were examined. The prevalence of caudal aberrant turbinates in this group was 100%. Using our proposed classification scheme, Grade 1 (minimal) was detected in 7 of 40 (17.5%), Grade 2 (mild) in 28 of 40 (70%), and Grade 3 (moderate) in 5 of 40 (12.5%) English Bulldogs. No significant effect of gender, weight, and age on degree of protrusion was found. In conclusion, this study identified minimal to moderate protrusion of caudal aberrant turbinates toward the nasopharynx in all the sampled English Bulldogs, despite the absence of clinical signs of brachycephalic airway syndrome.
ANGIOGRAPHIC ANATOMY OF THE MAJOR ABDOMINAL ARTERIAL BLOOD SUPPLY IN THE DOG
Authors: Culp William T. N. , Mayhew Philipp D. , Pascoe Peter J. , Zwingenberger Allison
Published: April 2015

Vascular‐based interventional radiology (IR) procedures are being more regularly performed in veterinary patients for both diagnostic and therapeutic purposes. A complete description of the fluoroscopic arterial anatomy of the canine abdominal cavity has not been published. This information is essential for performance of IR procedures to allow for improved preparation before and during a particular procedure. The primary purpose of this study was to provide a fluoroscopic description of the vascular branching from the abdominal aorta in a ventro‐dorsal projection with a secondary goal of producing pictorial reference images of the major abdominal arterial blood vessels. Five healthy female hound type dogs were enrolled and underwent fluoroscopic arteriography. During fluoroscopy, both nonselective and selective arteriography were performed. The nonselective arteriograms were obtained in the aorta at four locations: cranial to the celiac artery, cranial to the renal arteries, cranial to the caudal mesenteric artery, and cranial to the branching of the external iliac arteries. Selective arteriography was conducted by performing injections into the following arteries: celiac, splenic, common hepatic, cranial mesenteric, left and right renal, and caudal mesenteric. Fluoroscopic arteriography allowed for excellent characterization of the aortic ostia and the location of the lower order vascular branches. Future evaluation of vascular‐based treatment options will likely increase as the understanding of the normal and pathologic anatomy improves.
VALIDATION OF AN INDEXED RADIOTHERAPY HEAD POSITIONING DEVICE FOR USE IN DOGS AND CATS
Authors: Hansen Katherine S. , Théon Alain P. , Dieterich Sonja , Kent Michael S.
Published: April 2015

Setup variability affects the appropriate delivery of radiation and informs the setup margin required to treat radiation patients. Twenty‐four veterinary patients with head and neck cancers were enrolled in this prospective, cross‐sectional study to determine the accuracy of an indexed board immobilization device for positioning. Couch position values were defined at the first treatment based on setup films. At subsequent treatments, patients were moved to the previously defined couch location, orthogonal films were acquired, table position was modified, and displacement was recorded. The mean systematic displacement, random displacement, overall displacement, and mean displacement values of the three‐dimensional (3D) vector were calculated. Three hundred thirty‐two pairs of orthogonal setup films were analyzed for displacement in cranial–caudal, lateral, and dorsal–ventral directions. The mean systematic displacements were 0.5, 0.8, and 0.5 mm, respectively. The mean random displacements were 1.0, 1.1, and 0.7 mm, respectively. The overall displacements were 1.1, 1.4, and 0.9 mm, respectively. The mean 3D vector value was 1.6 mm with a standard deviation of 1.2 mm. Ninety‐five percent of the vectors were <3.6 mm. These values were compared to data obtained with a previously used immobilization device. A t‐test was used to compare the two devices. The 3D vector, random displacement in all directions, and overall displacement in the cranial–caudal and dorsal–ventral directions were significantly smaller than displacements with the previous device. The precision and accuracy of the indexed board device was superior to the historical head and neck device.
Noninvasive imaging technologies for cutaneous wound assessment: A review
Authors: Paul Dereck W. , Ghassemi Pejhman , Ramella‐Roman Jessica C. , Prindeze Nicholas J. , Moffatt Lauren T. , Alkhalil Abdulnaser , Shupp Jeffrey W.
Published: April 2015

The ability to phenotype wounds for the purposes of assessing severity, healing potential and treatment is an important function of evidence‐based medicine. A variety of optical technologies are currently in development for noninvasive wound assessment. To varying extents, these optical technologies have the potential to supplement traditional clinical wound evaluation and research, by providing detailed information regarding skin components imperceptible to visual inspection. These assessments are achieved through quantitative optical analysis of tissue characteristics including blood flow, collagen remodeling, hemoglobin content, inflammation, temperature, vascular structure, and water content. Technologies that have, to this date, been applied to wound assessment include: near infrared imaging, thermal imaging, optical coherence tomography, orthogonal polarization spectral imaging, fluorescence imaging, laser Doppler imaging, microscopy, spatial frequency domain imaging, photoacoustic detection, and spectral/hyperspectral imaging. We present a review of the technologies in use or development for these purposes with three aims: (1) providing basic explanations of imaging technology concepts, (2) reviewing the wound imaging literature, and (3) providing insight into areas for further application and exploration. Noninvasive imaging is a promising advancement in wound assessment and all technologies require further validation.
Hypoxic pulmonary vasoconstriction, carotid body function and erythropoietin production in adult rats perinatally exposed to hyperoxia
Authors: Prieto‐Lloret Jesus , Ramirez Maria , Olea Elena , Moral‐Sanz Javier , Cogolludo Angel , Castañeda Javier , Yubero Sara , Agapito Teresa , Gomez‐Niño Angela , Rocher Asuncion , Rigual Ricardo , Obeso Ana , Perez‐Vizcaino Francisco , González Constancio
Published: April 2015

Key points

Adult animals that have been perinatally exposed to oxygen‐rich atmospheres (hyperoxia), recalling those used for oxygen therapy in infants, exhibit a loss of hypoxic pulmonary vasoconstriction, whereas vasoconstriction elicited by depolarizing agents is maintained.

Loss of pulmonary hypoxic vasoconstriction is not linked to alterations in oxygen‐sensitive K+ currents in pulmonary artery smooth muscle cells.

Loss of hypoxic vasoconstriction is associated with early postnatal oxidative damage and corrected by an antioxidant diet.

Perinatal hyperoxia damages carotid body chemoreceptor cell function and the antioxidant diet does not reverse it. The hypoxia‐elicited increase in erythropoietin plasma levels is not affected by perinatal hyperoxia.

The potential clinical significance of the findings in clinical situations such as pneumonia, chronic obstructive pulmonary disease or general anaesthesia is considered.

Adult mammalians possess three cell systems that are activated by acute bodily hypoxia: pulmonary artery smooth muscle cells (PASMC), carotid body chemoreceptor cells (CBCC) and erythropoietin (EPO)‐producing cells. In rats, chronic perinatal hyperoxia causes permanent carotid body (CB) atrophy and functional alterations of surviving CBCC. There are no studies on PASMC or EPO‐producing cells. Our aim is to define possible long‐lasting functional changes in PASMC or EPO‐producing cells (measured as EPO plasma levels) and, further, to analyse CBCC functional alterations. We used 3‐ to 4‐month‐old rats born and reared in a normal atmosphere or exposed to perinatal hyperoxia (55–60% O2 for the last 5–6 days of pregnancy and 4 weeks after birth). Perinatal hyperoxia causes an almost complete loss of hypoxic pulmonary vasoconstriction (HPV), which was correlated with lung oxidative status in early postnatal life and prevented by antioxidant supplementation in the diet. O2‐sensitivity of K+ currents in the PASMC of hyperoxic animals is normal, indicating that their inhibition is not sufficient to trigger HPV. Perinatal hyperoxia also abrogated responses elicited by hypoxia on catecholamine and cAMP metabolism in the CB. An increase in EPO plasma levels elicited by hypoxia was identical in hyperoxic and control animals, implying a normal functioning of EPO‐producing cells. The loss of HPV observed in adult rats and caused by perinatal hyperoxia, comparable to oxygen therapy in premature infants, might represent a previously unrecognized complication of such a medical intervention capable of aggravating medical conditions such as regional pneumonias, atelectases or general anaesthesia in adult life.
A Simplified Structural Ceramic Design Technique
Authors: Hartsock Dale L.
Published: April 2015

This paper reviews the basic theory of the ceramic design methodology, and discusses the relative importance of the various parameters. A simplified technique is presented for estimation of the component reliability from the component stresses or for determining an acceptable design stress. These techniques can be used with or without a finite element stress analysis. A comparison of predicted probabilities of failure for actual components is made between the traditional computerized Weibull analysis and this simplified technique which shows reasonable agreement. An example of how to use this method is presented and an error analysis is included. This technique can be used to aid in material selections and design modifications, rank alternate designs and help the individual develop a “feel” for successful ceramic design.
Directionally Solidified DS CM 247 LC—Optimized Mechanical Properties Resulting From Extensive γ′ Solutioning
Authors: Erickson G. L. , Harris K. , Schwer R. E.
Published: April 2015

Complete coarse γ′ and greater than 90% eutectic γ-γ′ solutioning, without incipient melting, is demonstrated for the DS CM 247 LC superalloy. This unusual capability for this advanced Ni-base turbine blade and vane material results in considerable mechanical properties enhancement, with the DS alloy capability being near to current single crystal superalloys in the 345–207 MPa, 871°C–982°C (50–30 ksi, 1600°F–1800°F) operating condition. Microstructural features are detailed correlating strength and alloy stability.
Commercial Operation of the Racer Combined-Cycle System
Authors: Truman Peter
Published: April 2015

The RAnkine Cycle Energy Recovery (RACER) System represents a significant departure from the traditional approach to combined cycle. Innovative features are incorporated to provide benefits in reliability, simplicity, and cost of operation. This paper discusses experience gained with start-up and commercial operation of the new system and presents results of hardware inspection following the first year of use.
Cooperative Education by the University of Cincinnati and GE
Authors: Zinn William O.
Published: April 2015

The Advanced Course in Engineering (ACE) was started in 1923 at the Alternating Current Engineering Department of the General Electric Company by Dr. Robert E. Doherty. The purpose of this program was, and still is, to teach advanced technology, to solve real engineering problems and to learn how to write good engineering reports. The 61-year-old Advanced Course is less than half as old as the University of Cincinnati. The University of Cincinnati was founded in 1819 as Cincinnati College. In addition to its excellent research programs, the University of Cincinnati is also recognized for its leadership in cooperative education. “The academic climate was set early in this century by Dean Herman Schneider, the originator of the cooperative plan of education. The objective of that plan was to join theory and practice by linking education and industry through knowledge and experience.” The educational objectives of the University of Cincinnati (UC) and the General Electric Company (GE) have been joined through the Advanced Course in Engineering in the university’s College of Engineering.
Description of an Industry–University Liaison: Rolls-Royce Scottish Factories–Glasgow University 1968–84
Authors: Maccallum N. R. L. , Reford F. S.
Published: April 2015

The paper describes the liaison that has developed between Rolls-Royce Limited (Scottish Factories) and the Department of Mechanical Engineering of the University of Glasgow and indicates the benefits that have been obtained by both sides.

Of benefit to the University have been stimulating contacts with industry, from which have come topics for meaningful investigations, both in projects by undergraduates and in research by postgraduates and staff. Students at the University have also benefited by being able to visit Rolls-Royce’s Scottish Factories, and have Rolls-Royce staff give lectures to the Engineering Society.

One advantage to Rolls-Royce is that students at Glasgow University have had frequent contacts with the Company and are aware of its aims and achievements. Also, there has been technical benefit to the Company from the general research and from several specific studies carried out on a consultancy basis.
Conversion of Decommissioned Aircraft Gas Turbines to High-Efficiency Marine Units
Authors: Wilson David Gordon , Poole P. K. , Owens L. D. , Baglione J.
Published: April 2015

Some helicopter and other engines have been shown in studies to be amenable to conversion to a low-pressure-ratio highly regenerated cycle. Typically the high-pressure compressor and high-pressure turbine would be removed, and shaft and ducting modifications would be made to introduce high-effectiveness rotary ceramic-honeycomb regenerators. In one case examined the low-pressure turbine could be used with slight modification; in others there would have to be reblading of the turbine stages and the manufacture of new shrouds. In another case the existing combustor could be used with little modification; in others new combustors would be required. Despite the extent of the modifications, the resulting high-efficiency performance over a large part of the power range and presumably relatively low capital and development costs could make this an attractive concept.
Assessment of a Failure Probability Prediction Technique for Ceramic Heat Exchanger Components
Authors: Smith Kenneth O. , Poeppel Roger B.
Published: April 2015

A study was conducted to establish analytical design techniques for predicting the failure probability of ceramic heat exchanger components. Three test specimen geometries representing subscale components of an axial flow, tubular ceramic heat exchanger were selected for evaluation. Failure probability predictions for the specimens subjected to mechanical loads were made using finite element stress and two-parameter Weibull analyses. Weibull parameters for sintered alpha-SiC were determined using as-sintered flexure bars in four-point-bend strength tests.

Assessments of the prediction accuracy were made by failure testing populations of the three specimen geometries fabricated using sintered alpha–SiC. Tests were conducted at ambient conditions and with a rapid loading rate. Experimental results indicate that reasonably accurate failure probability predictions can be made.
Stress Rupture Test Rig Design for Evaluating Ceramic Material Specimens
Authors: Govila R. K. , Herman J. A. , Arnon N.
Published: April 2015

A simple flexural stress rupture test rig has been designed, constructed and operated successfully in evaluating high-temperature (≥1200°C) time-dependent strength of ceramic materials. The test rig is capable of applying stresses up to ∼700 MPa and at temperatures as high as 1400°C in air.
Advancements in Application of Ceramics to the Gemini Radial-Flow Gas Turbine
Authors: Napier James C. , Arnold J. P.
Published: April 2015

A ceramic vane turbine nozzle design has completed over 2000 hours of engine endurance testing for production qualification in the Gemini radial-flow turbine manufactured by the TurboMach Division of Solar Turbines Incorporated. The nozzle offers the advantage of substantial erosion and corrosion durability over all-superalloy types. Cost effective production methods and tooling have been demonstrated on a production lot of nozzles and all preproduction tasks including establishment of ceramic vane acceptance criteria have been completed. Further application of ceramics to the Gemini turbine are described and include all static hot-section components, i.e., combustor liner, combustor scroll, nozzle assembly and exhaust scroll. These ceramic components allow temperature up-rating of the Gemini turbine’s power by 50 percent.
Regionally Averaged Endwall Heat Transfer Correlations for a Linear Vane Cascade
Authors: Kumar G. N. , Jenkins R. M. , Sahu U.
Published: April 2015

This paper presents an analysis of endwall heat transfer correlations for a linear vane cascade. The data base used for the present correlations was developed originally by Detroit Diesel Allison (now Allison Gas Turbine Division, General Motors) under a contract sponsored jointly by the Air Force Aero Propulsion Laboratory, Wright-Patterson AFB, Ohio, and NASA-Lewis Research Center, Cleveland, Ohio. Correlations are made for overall averaged, regionally averaged, and locally averaged values of Stanton number. Emphasis, however, has been placed on regional averages; regions of particular interest are the cascade leading edge (pressure side) and the cascade trailing edge wake. Independent parameters used in the correlations are exit Reynolds number, exit Mach number, inlet turbulence intensity, and average wall-to-gas temperature ratio. Typical inferences to be drawn from the correlations include a minimal dependency on Mach number and a greater than expected dependency on wall-to-gas temperature ratio.
Influence of Particle Erosion on the Microstructural Changes in Metals and Alloys
Authors: Moteff John , Rosa Eduardo
Published: April 2015

The microstructural changes that occur in metals and alloys exposed to pneumatic particle erosion conditions are determined through microhardness measurements performed on the cross-section of the target material. In particular, the hardness gradient in an inward direction normal to the eroded surface is determined for pure Cu, AISI 304 stainless steel, and for AISI 1020 steel having various degrees of cold-work. The elevated temperature erosion behavior of Ti-6Al-4V as a function of the elevated temperature surface microhardness and ductility clearly shows significant differences when evaluated above and below about one-half of the absolute melting temperature of this alloy.
A General Program for the Prediction of the Transient Performance of Gas Turbines
Authors: Pilidis P. , Maccallum N. R. L.
Published: April 2015

The paper describes a general program which has been developed for the prediction of the transient performance of gas turbines. The program is based on the method of continuity of mass flow. It has been applied successfully to a wide range of aero gas turbines, ranging from single to three-spool and from simple jet to bypass types with or without mixed exhausts. The results for three of these engine types are illustrated. Computing times are reasonable, increasing with the complexity of the engine.

A parallel paper describes the inclusion of thermal effects in the prediction program.
Fan Blade Flutter: Single Blade Instability or Blade to Blade Coupling?
Authors: Széchényi Edmond
Published: April 2015

Different types of fan blade flutter occur at the various compressor flow regimes. Sub/transonic stall flutter and two forms of supersonic started flow flutter have been studied in a straight cascade wind tunnel. Results show clearly that these three common forms of flutter can exist as single-degree-of-freedom (single-blade instabilities). Cascade effects, though at times important, are never the only flutter mechanism: flutter limits are essentially controlled by single-blade aeroelastic coefficients, though blade-to-blade coupling arising from cascade effects can modify these limits according to the mode order.

Thus, contrary to widespread practice, the fundamental approach to flutter problems should lie at least as much in the study of single blade flutter as in that of unsteady cascade effects. The two should anyhow best be considered separately when searching for a better physical insight.
Gas Turbine Heat Recovery Systems: Considerations in Operating at Fired and Unfired Modes
Authors: Pasha Akber
Published: April 2015

More and more gas turbine heat recovery systems these days are required to operate at various conditions. These include a wide range of ambient temperatures, various gas turbine loads and frequently changing steam requirements. For unfired heat recovery steam generators, at off-design gas turbine loads, it may not be possible to produce the required amount of steam. On these occasions an in-duct firing system may be employed to make up the deficiency. When a heat recovery system is designed to operate in both the fired and unfired modes, the design parameters which affect the system performance are influenced. This paper discusses the relative importance of each design factor, their variation in different fired and unfired operating modes, the problems created because of these variations, and suggested procedures to alleviate these problems. The main objective of the paper is to make the user aware of the problem encountered in operating a heat recovery system at more than one load point and to present guidelines to select an appropriate design.
Blade Vibration on Centrifugal Compressors: Blade Response to Different Excitation Conditions
Authors: Haupt U. , Bammert K. , Rautenberg M.
Published: April 2015

Results and analysis of blade vibration measurements on a high pressure ratio / high mass flow centrifugal compressor made with strain gages and using multichannel telemetry are described for compressors with 3 different types of vaned diffusers. Considerable high frequency blade excitation and vibration of the shallow region near the impeller outlet were observed. Initial progress to predict this dangerous excitation caused by the diffuser vanes was made with the help of FE computations using a simplified element system consisting of the vibrating zones of a 90° sector of the impeller. Satisfactory agreement with measured vibration data was achieved.

The influence of rotating stall on blade excitation was investigated using different types of vaned diffusers leading to different numbers of rotating stall zones and variations in the rotational speed of the cells. Blade vibration intensity due to surge in conjunction with variations of the diffuser is also considered.

Holographic interferometry was successfully applied to blade vibration measurements on compressors in operation. The investigation was aimed at studying the occurrence of blade modes and the vibratory behavior of the different blades near the interesting inlet zone. The occurrence of different constellations of blade modes at a resonance point and at an operating point far from resonance was demonstrated.
Development of a Portable Field Machinery Data Acquisition System
Authors: Drinkwater Ben J. , Brashears Chris , Wilson Dennis G.
Published: April 2015

This paper describes the development of a portable data acquisition system for use in a plant-wide, predictive maintenance program for rotating machinery. Designed to replace hand-logging and other clipboard surveillance methods, the portable instrument stores the measured parameters in digital memory for transfer to a desktop host computer for processing and analysis. Developments in electronics and computer technology as well as preventive/predictive maintenance procedures have made this instrument system possible. These developments are outlined, along with a discussion of the operation and use of the system.
The Effect of Thermal Matching on the Thermodynamic Performance of Gas Turbine and IC Engine Cogeneration Systems
Authors: Baughn J. W. , Bagheri N.
Published: April 2015

Computer models have been used to analyze the thermodynamic performance of a gas turbine (GT) cogeneration system and an internal combustion engine (IC) cogeneration system. The purpose of this study was to determine the effect of thermal matching of the load (i.e., required thermal energy) and the output steam fraction (fraction of the thermal output, steam and hot water, which is steam) on the thermodynamic performance of typical cogeneration systems at both full and partial output.

The thermodynamic parameters considered were; the net heat rate (NHR), the power to heat ratio (PHR), and the fuel savings rate (FSR). With direct use (the steam fractions being different); the NHR of these two systems is similar at full output, the NHR of the IC systems is lower at partial output, and the PHR and the FSR of the GT systems is lower than the IC systems over the full range of operating conditions. With thermal matching (to produce a given steam fraction) the most favorable NHR, PHR, and FSR depends on the method of matching the load to the thermal output.
Design and Testing of a 10KW Steam Turbine for Steam Turbochargers
Authors: Rautenberg M. , Malobabic M. , Mobarak A. , Abdel Kader M.
Published: April 2015

A Clausius-Rankine-cycle has been proposed to recover waste heat from a piston engine. This waste heat is then used to supercharge the cylinders by means of a steam turbocharger. The advantage of using this steam turbocharger system is to avoid the losses due to the engine back pressure which accompany the use of the conventional exhaust gas turbocharger. The mass flow rate of turbines for steam turbochargers in the range from 1 to 10 kW is about 0.03 to 0.08 kg/s. This implies a special turbine design, characterised by partial admission and supersonic flow, which unfortunately leads to low turbine efficiencies. A small Pelton turbine for steam has been designed and produced. The turbine is connected to the radial compressor of a conventional exhaust gas turbocharger which works, in this case, as a brake to dissipate the generated turbine power. A special test rig has been built to carry out the experimental investigations on the proposed Pelton turbine. The test rig is supplied with superheated steam from the University’s power plant. Two different rotors for this Pelton turbine have been tested under the same operating conditions (rotor 2 see Fig. 1). Some experimental test results of a special Pelton turbine are presented and discussed in this report.
Smoke Emissions From Lean Well Mixed Gas Turbine Primary Zones
Authors: Abdul-Aziz M. M. , Andrews G. E.
Published: April 2015

Smoke emissions for a Jet Mix flame stabiliser at lean gas turbine combustor primary zone conditions are reported at a 600K operating temperature and 1 bar pressure for kerosene. The influence of pressure loss was studied, this influences the fuel and air mixing and the liquid drop size and hence has an influence on smoke emissions. Two flame stabiliser designs were studied with different fuel and air mixing rates. The results show that even for lean well mixed situations factors that influence local fuel and mixing also influence smoke emissions.
An Experimental Investigation of Response of a Turbojet Engine to Inlet Distortion
Authors: Fuqun Chen , Wenlan Li , Zongyuan Wang , Mengzi Cong
Published: April 2015

A study of the response of a turbojet engine to the steady-state and the turbulence-type dynamic inlet distortion is presented in this paper. The steady-state distortion is generated by a 180° extent, 36 mesh screen, and the turbulence-type dynamic distortion by a 180° extent plate with 50% blockage ratio at the engine face. This plate can produce a very strong pressure fluctuation at the engine face. The statistical analysis shows that the APD of pressure fluctuation follows approximately the Normal Distribution except those cases near rotating stall or surge.

Results from testing show: 1) inlet distortion generated by screen will produce a classical-surge or deep-surge (defined in ref. 1); 2) the degree of distortion by screen can change the mode of surge, e.g. from the classical-surge to the deep-surge and vice versa; 3) both the inlet distortion and the decrease in first-stage-turbine-nozzle area will change the compressor performance maps; 4) the turbulence-type dynamic distortion causes a “drift-surge” (defined in ref. 2).
Gas Turbine Combustion Efficiency
Authors: Schlein Barry
Published: April 2015

A method of correlating combustor efficiency as a function of geometry and operating conditions is presented. A simple equation correlates all the data for a given engine type with a single parameter. The correlating parameter is a function of fuel flow, pressure, temperature and volume in a form similar to others in the literature. The unique feature of the correlating parameter is its use of internal gas temperature rather than the commonly used combustor inlet temperature. The result is an equation requiring an iterative solution since combustion efficiency is a part of the correlating parameter. With use of a computer this is easily handled. The correlation fits engine data over all flight conditions from high altitude, high Mach number to sea level idle. The correlation is compared to engine test data for several engines.
Some Problems in Calculating Flow Around Two-Dimensional Cascade Profiles
Authors: Hao-Xin Jiang , Mao-Zhang Chen , Chih-Ya Tsui
Published: April 2015

A new method which can be used to construct a H-type grid for cascade flow calculation is presented in this paper. To test the feasibility of the grid, the subsonic and transonic full potential equations are solved by using finite difference approximations on a transformed coordinate system. It is found that in order to improve computing accuracy and reduce cost, four conditions should be fulfilled in constructing cascade grids. Also, the artificial viscosity scheme should be improved for cascade calculations.
Gaseous Fuels Capability of Industrial Gas Turbines
Authors: Hung W. S. Y. , Meier J. G.
Published: April 2015

This paper describes the successful development and application of industrial gas turbines using alternate gaseous fuels. These fuels include liquid petroleum gas, medium-Btu fuels derived from biodegradation of organic matters found in sanitary landfills and liquid sewage, and ultra-low Btu fuels from oilfield fireflood operations. The analyses, mathematical modelling and rig verification performed in the development are discussed. The effects of burning these alternate fuels on the gas turbine and its combustion system are compared to those of using standard natural gas fuel. Gas turbine development required to use other alternative gaseous fuels is also assessed.
Transonic Cascade Analysis by a Time Marching Method
Authors: Martelli Francesco , Marchi Luca
Published: April 2015

Time marching solutions of transonic flow are widely used for the analysis of turbomachinery cascades. Attempts to increase efficiency, accuracy and computational speed are, at present, the main goal of research in the field of two dimensional flow. The aim of the paper is the presentation of a new pseudo-time dependent method to try to achieve these goals. The method, basic idea and procedure used to develop the new formulation are described and discussed in brief. Some applications of the method to transonic turbine cascades are presented against experimental results. The accuracy and speed of the method is discussed and possibilities for further developments are shown.
Gas Turbines in Cogeneration: Overall Analysis and Numerical Predictions
Authors: Manfrida G. , Stecco S. S. , Galletti A.
Published: April 2015

A methodology for the performance analysis of gas turbines for cogeneration applications is presented. Energy and exergy balances allow presentation of data in terms of either conventional or second-law parameters, as well as examination of the trends with respect to cycle variables and cogeneration options.

The results show that, even though gas turbines (and particularly regenerative solutions) are very flexible for cogeneration purposes, care has to be exercised in matching thermal energy production conditions and cycle variables in order to achieve optimal performance.
Research on the Multicomponent Diffusion Theory and its Application to the Calculation of Evaporation Histories of Multicomponent Droplets
Authors: Zhen-Tang Zhang , Yao-De Dong , Ru-Hui Li
Published: April 2015

In this paper, a method is presented to obtain the exact solution of the Stefan-Maxwell equations for multicomponent diffusion systems. This method is the continuation of Gilliland and Toor’s works for ternary diffusion systems. As an example, a solution of the Stefan-Maxwell equations for four-component system is given. Finally, the result is used for the calculation of the evaporation histories of multicomponent fuel droplets in hot air flow. The calculated results are favorably compared with the experimental data.