bluuebunny/crossref_metadata_2025 huggingface dataset:
The rapid decay property and centroids in groups
Authors: Sapir Mark
Published: May 2015

This is a survey of methods of proving or disproving the rapid decay property in groups. We present a centroid property of group actions on metric spaces. That property is a generalized (and corrected) version of the "(**)-relative hyperbolicity" from [9] and implies the rapid decay (RD) property. We show that several properties which are known to imply RD also imply the centroid property. Thus uniform lattices in many semi-simple Lie groups, graph products of groups, Artin groups of large type and the mapping class groups have the (relative) centroid property. We also present a simple "non-amenability-like" property that follows from RD, and give an easy example of a group without RD and without any amenable subgroup with superpolynomial growth.
Cardiomyocyte mitochondrial respiration is reduced by receptor for advanced glycation end-product signaling in a ceramide-dependent manner
Authors: Nelson Michael B. , Swensen Adam C. , Winden Duane R. , Bodine Jared S. , Bikman Benjamin T. , Reynolds Paul R.
Published: May 2015

Cigarette smoke exposure is associated with an increased risk of cardiovascular complications. The role of advanced glycation end products (AGEs) is already well established in numerous comorbidities, including cardiomyopathy. Given the role of AGEs and their receptor, RAGE, in activating inflammatory pathways, we sought to determine whether ceramides could be a mediator of RAGE-induced altered heart mitochondrial function. Using an in vitro model, we treated H9C2 cardiomyocytes with the AGE carboxy-methyllysine before mitochondrial respiration assessment. We discovered that mitochondrial respiration was significantly impaired in AGE-treated cells, but not when cotreated with myriocin, an inhibitor of de novo ceramide biosynthesis. Moreover, we exposed wild-type and RAGE knockout mice to secondhand cigarette smoke and found reduced mitochondrial respiration in the left ventricular myocardium from wild-type mice, but RAGE knockout mice were protected from this effect. Finally, conditional overexpression of RAGE in the lungs of transgenic mice elicited a robust increase in left ventricular ceramides in the absence of smoke exposure. Taken together, these findings suggest a RAGE-ceramide axis as an important contributor to AGE-mediated disrupted cardiomyocyte mitochondrial function.
Increased superoxide production and altered nitric oxide-mediated relaxation in the aorta of young but not old male relaxin-deficient mice
Authors: Ng Hooi H. , Jelinic Maria , Parry Laura J. , Leo Chen-Huei
Published: May 2015

The vascular effects of exogenous relaxin (Rln) treatment are well established and include decreased myogenic reactivity and enhanced relaxation responses to vasodilators in small resistance arteries. These vascular responses are reduced in older animals, suggesting that Rln is less effective in mediating arterial function with aging. The present study investigated the role of endogenous Rln in the aorta and the possibility that vascular dysfunction occurs more rapidly with aging in Rln-deficient ( Rln−/−) mice. We compared vascular function and underlying vasodilatory pathways in the aorta of male wild-type ( Rln+/+) and Rln−/− mice at 4 and 16 mo of age using wire myography. Superoxide production, but not nitrotyrosine or NADPH oxidase expression, was significantly increased in the aorta of young Rln−/− mice, whereas endothelial nitric oxide (NO) synthase and basal NO availability were both significantly decreased compared with Rln+/+ mice. In the presence of the cyclooxygenase inhibitor indomethacin, sensitivity to ACh was significantly decreased in young Rln−/− mice, demonstrating altered NO-mediated relaxation that was normalized in the presence of a membrane-permeable SOD or ROS scavenger. These vascular phenotypes were not exacerbated in old Rln−/− mice and, in most cases, did not differ significantly from old Rln+/+ mice. Despite the vascular phenotypes in Rln−/− mice, endothelium-dependent and -independent vasodilation were not adversely affected. Our data show a role for endogenous Rln in reducing superoxide production and maintaining NO availability in the aorta but also demonstrate that Rln deficiency does not compromise vascular function in this artery or exacerbate endothelial dysfunction associated with aging.
Flow-Dependent Epigenetic DNA Methylation in Endothelial Gene Expression and Atherosclerosis
Authors: Dunn Jessilyn , Thabet Salim , Jo Hanjoong
Published: May 2015

Epigenetic mechanisms that regulate endothelial cell gene expression are now emerging. DNA methylation is the most stable epigenetic mark that confers persisting changes in gene expression. Not only is DNA methylation important in rendering cell identity by regulating cell type–specific gene expression throughout differentiation, but it is becoming clear that DNA methylation also plays a key role in maintaining endothelial cell homeostasis and in vascular disease development. Disturbed blood flow causes atherosclerosis, whereas stable flow protects against it by differentially regulating gene expression in endothelial cells. Recently, we and others have shown that flow-dependent gene expression and atherosclerosis development are regulated by mechanisms dependent on DNA methyltransferases (1 and 3A). Disturbed blood flow upregulates DNA methyltransferase expression both in vitro and in vivo, which leads to genome-wide DNA methylation alterations and global gene expression changes in a DNA methyltransferase–dependent manner. These studies revealed several mechanosensitive genes, such as HoxA5, Klf3, and Klf4, whose promoters were hypermethylated by disturbed blood flow, but rescued by DNA methyltransferases inhibitors such as 5Aza-2-deoxycytidine. These findings provide new insight into the mechanism by which flow controls epigenomic DNA methylation patterns, which in turn alters endothelial gene expression, regulates vascular biology, and modulates atherosclerosis development.
Elevated Plasma Levels of MMP-12 Are Associated With Atherosclerotic Burden and Symptomatic Cardiovascular Disease in Subjects With Type 2 Diabetes
Authors: Goncalves Isabel , Bengtsson Eva , Colhoun Helen M. , Shore Angela C. , Palombo Carlo , Natali Andrea , Edsfeldt Andreas , Dunér Pontus , Fredrikson Gunilla Nordin , Björkbacka Harry , Östling Gerd , Aizawa Kunihiko , Casanova Francesco , Persson Margaretha , Gooding Kim , Strain David , Khan Faisel , Looker Helen C. , Adams Fiona , Belch Jill , Pinnoli Silvia , Venturi Elena , Kozakova Michaela , Gan Li-Ming , Schnecke Volker , Nilsson Jan
Published: May 2015

Objective—

Matrix metalloproteinases (MMPs) degrade extracellular matrix proteins and play important roles in development and tissue repair. They have also been shown to have both protective and pathogenic effects in atherosclerosis, and experimental studies have suggested that MMP-12 contributes to plaque growth and destabilization. The objective of this study was to investigate the associations between circulating MMPs, atherosclerosis burden, and incidence of cardiovascular disease with a particular focus on type 2 diabetes mellitus.

Approach and Results—

Plasma levels of MMP-1, -3, -7, -10, and -12 were analyzed by the Proximity Extension Assay technology in 1500 subjects participating in the SUMMIT (surrogate markers for micro- and macrovascular hard end points for innovative diabetes tools) study, 384 incident coronary cases, and 409 matched controls in the Malmö Diet and Cancer study and in 205 carotid endarterectomy patients. Plasma MMP-7 and -12 were higher in subjects with type 2 diabetes mellitus, increased with age and impaired renal function, and was independently associated with prevalent cardiovascular disease, atherosclerotic burden (as assessed by carotid intima-media thickness and ankle-brachial pressure index), arterial stiffness, and plaque inflammation. Baseline MMP-7 and -12 levels were increased in Malmö Diet and Cancer subjects who had a coronary event during follow-up.

Conclusions—

The plasma level of MMP-7 and -12 are elevated in type 2 diabetes mellitus, associated with more severe atherosclerosis and an increased incidence of coronary events. These observations provide clinical support to previous experimental studies, demonstrating a role for these MMPs in plaque development, and suggest that they are potential biomarkers of atherosclerosis burden and cardiovascular disease risk.
Common NOTCH3 Variants and Cerebral Small-Vessel Disease
Authors: Rutten-Jacobs Loes C.A. , Traylor Matthew , Adib-Samii Poneh , Thijs Vincent , Sudlow Cathie , Rothwell Peter M. , Boncoraglio Giorgio , Dichgans Martin , Bevan Steve , Meschia James , Levi Christopher , Rost Natalia S. , Rosand Jonathan , Hassan Ahamad , Markus Hugh S.
Published: May 2015

Background and Purpose—

The most common monogenic cause of cerebral small-vessel disease is cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy, caused by
NOTCH3
gene mutations. It has been hypothesized that more common variants in
NOTCH3
may also contribute to the risk of sporadic small-vessel disease. Previously, 4 common variants (rs10404382, rs1043994, rs10423702, and rs1043997) were found to be associated with the presence of white matter hyperintensity in hypertensive community-dwelling elderly.

Methods—

We investigated the association of common single nucleotide polymorphisms (SNPs) in
NOTCH3
in 1350 patients with MRI-confirmed lacunar stroke and 7397 controls, by meta-analysis of genome-wide association study data sets. In addition, we investigated the association of common SNPs in
NOTCH3
with MRI white matter hyperintensity volumes in 3670 white patients with ischemic stroke. In each analysis, we considered all SNPs within the
NOTCH3
gene, and within 50-kb upstream and downstream of the coding region. A total of 381 SNPs from the 1000 genome population with a mean allele frequency >0.01 were included in the analysis. A significance level of
P
<0.0015 was used, adjusted for the effective number of independent SNPs in the region using the Galwey method.

Results—

We found no association of any common variants in
NOTCH3
(including rs10404382, rs1043994, rs10423702, and rs1043997) with lacunar stroke or white matter hyperintensity volume. We repeated our analysis stratified for hypertension but again found no association.

Conclusions—

Our study does not support a role for common
NOTCH3
variation in the risk of sporadic small-vessel disease.
Methodological Factors in Determining Risk of Dementia After Transient Ischemic Attack and Stroke
Authors: Pendlebury Sarah T. , Chen Ping-Jen , Welch Sarah J.V. , Cuthbertson Fiona C. , Wharton Rose M. , Mehta Ziyah , Rothwell Peter M.
Published: May 2015

Background and Purpose—

Cognitive outcomes in cohorts and trials are often based only on face-to-face clinic assessment. However, cognitive impairment is strongly associated with increased morbidity and mortality, leading to substantial loss to clinic follow-up. In the absence of previous population-based data, we determined the effect of such attrition on measured risk of dementia after transient ischemic attack and stroke.

Methods—

Patients with transient ischemic attack or stroke prospectively recruited (2002–2007) into the Oxford Vascular (OXVASC) study had baseline clinical/cognitive assessment and follow-up to 2014. Dementia was diagnosed through face-to-face clinic interview, supplemented by home visits and telephone assessment in patients unable to attend clinic and by hand-searching of primary care records in uncontactable patients.

Results—

Of 1236 patients (mean age/SD, 75.2/12.1 years; 582 men), 527 (43%) died by 5-year follow-up. Follow-up assessment rates (study clinic, home visit, or telephone) of survivors were 947 in 1026 (92%), 857 in 958 (89%), 792 in 915 (87%), and 567 in 673 (84%) at 1, 6, 12 months and 5 years. Dementia developed in 260 patients, of whom 110 (42%; n=50 primary care records, n=49 home visit, and n=11 telephone follow-up) had not been available for face-to-face clinic follow-up at the time of diagnosis. The 5-year cumulative incidence of postevent dementia was 29% (26%–32%) overall but was only 17% (14% to 19%) in clinic assessed versus 45% (39%–51%) in nonclinic-assessed patients (
P
difference<0.001).

Conclusions—

Exclusion of patients unavailable for clinic follow-up reduces the measured risk of postevent dementia. Use of multiple follow-up methods, including home visits, telephone assessments, and consent, to access primary care records substantially increases ascertainment of longer-term dementia outcomes.
Because I Said So: Practical Authority in Plato’s Crito
Authors: Lott Micah
Published: May 2015

This essay is an analysis of the central arguments in Plato’s Crito. The dialogue shows, in a variety of ways, that the opinion of another person can have practical relevance in one’s deliberations about what to do – e.g. as an argument, as a piece of expert advice, as a threat. Especially important among these forms of practical relevance is the relevance of authoritative commands. In the dialogue, the Laws of Athens argue that Socrates must accept his sentence of death, because he must regard the court’s verdict as a command from a practical authority – the city. The Laws’ arguments rely on special features of authority-reasons that many commentators have overlooked. This article explains why the Law’s arguments are unsuccessful. Finally, it is argued that Socrates’ description of ‘the many’ suggests that the city lacks the deliberative capacity necessary for possessing practical authority.1
Eugenia kuhlmanniana (Myrtaceae), a new synonym of E. hiraeifolia, a Mesoamerican species cultivated in Brazil
Authors: Mazine Fiorella , Faria Jr. Jair Eustáquio Quintino , Souza Marcelo Costa , Lucas Eve
Published: May 2015

The synonymization of Eugenia kuhlmanniana Mattos & D. Legrand, previously described as endemic from Rio de Janeiro, Brazil, under Eugenia hiraeifolia Standley is proposed.
A new species of Canavalia (Leguminosae, Papilionoideae) from Brazil with a specialized corolla suggesting bird pollination
Authors: Snak Cristiane , Lewis Gwilyn Peter , Rocha Douglas Eduardo , Queiroz Luciano Paganucci
Published: May 2015

During the development of a systematic study of the species of Canavalia from the New World a new species with floral morphology suggesting a bird pollination system was found, contrasting with the bee pollination pattern of the genus. Canavalia reflexiflora differs from the other species of the genus mainly by its flowers with a reflexed standard; in addition, it also has red flowers, wing and keel petals as long as the standard petal, and an oblong seed with the hilum surrounding nearly half the seed circumference.
Orobanche apuana (Orobanchaceae) a new species endemic to Italy
Authors: Domina Gianniantonio , Soldano Adriano
Published: May 2015

Orobanche apuana, a new species belonging to Orobanche sect. Orobanche, is described and illustrated from the Apuan Alps, Central Italy. Its relationships with the other species of the group of O. caryophyllacea (O. grex Galeatae) and with other Orobanche that parasitize Santolina species are examined. The names Boulardia latisquama, Orobanche lutea and O. teucrii are here lectotypified.
Studies on Lophocoleaceae. XXIV. Chiloscyphus alpicola J.J.Engel, an interesting new liverwort species from New Zealand together with nomenclatural changes in Tetracymbaliella Grolle
Authors: Engel John
Published: May 2015

Chiloscyphus alpicola J.J.Engel, a new member of the Lophocoleaceae from New Zealand, is described and illustrated and Tetracymbaliella subsimplex (Austin) J.J.Engel, endemic to Tasmanian, is a new combination.
Selaginella daozhenensis (Selaginellaceae), a new lycophyte from a limestone cave in northern Guizhou, China
Authors: Sun Qing-Wen , Zhao Jun-Hua , Zhang Libing
Published: May 2015

Selaginella daozhenensis, a new species of the lycophyte genus Selaginella (Selaginellaceae) from a limestone cave in northern Guizhou, China is described and illustrated. The new species is morphologically most similar to S. labordei and S. sichuanica but is distinct by its leaves being bluish green when fresh, its median leaves having aristae as long as leaf lamina, and its lateral leaves being larger (3.5–5.0 × 1.7–2.5 mm). Selaginella daozhenensis is currently known only from a single limestone cave and is considered to be Critically Endangered (CR), based on IUCN Red List criteria. It is also argued that S. sichuanica, earlier wrongly synonymized with S. labordei in treatments of the genus, should be recognized.
Distrianthes exxonmobilensis (Loranthaceae), a new species in a formerly monotypic genus from Papua New Guinea
Authors: Takeuchi Wayne
Published: May 2015

Distrianthes exxonmobilensis is described from karst environments along the PNG LNG Pipeline in southern New Guinea. It is the second species in a genus previously regarded as monotypic. The new loranth is distinguished by an inflorescence reduced to a single flower or triad, and by the geographic disjunction from previous generic localities.
Phylogeny of Protopolybia Ducke, 1905 and taxonomic revision of the Protopolybia exigua species-group (Hymenoptera: Vespidae, Polistinae), with description of four new species
Authors: JUNIOR JOSÉ N. A. DOS SANTOS , SILVEIRA ORLANDO T. , CARPENTER JAMES M.
Published: May 2015

A first phylogenetic hypothesis is proposed for Protopolybia Ducke, 1905 based on cladistic analysis of 31 species. New evidence in support of monophyly of the genus is presented. A revision of the Protopolybia exigua species-group is also presented. Protopolybia diligens (Smith, 1857), stat. resurr. is revalidated. Four new species are described: P. collombiana Santos, Silveira & Carpenter, sp. nov., P. clypeata Santos, Silveira & Carpenter, sp. nov., P. similis Santos, Silveira & Carpenter, sp. nov., and P. potiguara Santos, Silveira & Carpenter, sp. nov. Protopolybia holoxantha (Ducke, 1904) and P. rubrithorax Bequaert, 1944 are redescribed. New synonymy is proposed for P. bituberculata Silveira & Carpenter, 1995 =Polybia nana Cameron, 1912 (nom. praeocc., nec de Saussure 1863), syn. nov. New records and description of the male genitalia are provided for some of the species of the P. exigua species-group.
Association of Convection with the 5-Day Rossby–Haurwitz Wave
Authors: King Malcolm J. , Wheeler Matthew C. , Lane Todd P.
Published: May 2015

The seasonality, regionality, and nature of the association between tropical convection and the 5-day wavenumber-1 Rossby–Haurwitz wave are examined. Spectral coherences between daily outgoing longwave radiation (OLR), a proxy for convection, and 850-hPa zonal wind over the period January 1979–February 2013 are compared for different seasons and for phases of El Niño–Southern Oscillation (ENSO) and the quasi-biennial oscillation (QBO). Increased coherence, indicating a stronger association, occurs in boreal spring and autumn, with slightly reduced coherence in boreal summer and significantly reduced coherence in boreal winter. The regionality of the association is examined using lagged-regression techniques. Significant local signals in tropical convection are found over West Africa, the tropical Andes, the eastern Pacific Ocean, and the Marshall Islands. The relative phasing between the 5-day wave wind and OLR signals is in quadrature in Africa and the Marshall Islands, in phase with easterlies over the Andes, and out of phase with easterlies over the eastern Pacific. Frequency spectra of precipitation averaged over the identified local regions reveal spectral peaks in the 4–6-day range. The phasing between the large-scale wind and local convection signals suggests that the 5-day wave is actively modulating the convection around the Americas.
Transformer Leakage Reactance Determination by Test
Authors: Jain S. K.
Published: May 2015

A method to determine separate values of primary and secondary leakage reactances of a transformer is given. An experimental determination of input impedance, open circuit time constant and dc resistance of one of the windings of the transformer, yields the required reactances.
A Visual Teaching Aid for the Two-Wattmeter Method
Authors: Thomas D. H.
Published: May 2015

The description is sufficient for this device to be constructed. The phasor diagram of the currents and voltages involved in the two-wattmeter are projected; the current phasors can be rotated to correspond to various power factors. Point-by-point consideration clarifies the effect on instrumental readings.
A Ball-Balancing System for Demonstration of Basic Concepts in the State-Space Control Theory
Authors: Jørgensen V.
Published: May 2015

The Ball-balancing Systems is intended to demonstrate the basic concepts in the state-space control theory in the graduate education. The physical properties of the system are stated and the mathematical model is evaluated. Conditions of stability are discussed.
An Elementary Approach to D.C. Voltage Regulators
Authors: Ashok S.
Published: May 2015

Feedback d.c. voltage regulators are developed as a natural extension of the simple zener diode regulator. Instead of using the usual feedback loop approach, controlled current and voltage sources are introduced in the development of a simple incremental equivalent circuit for series and shunt feedback regulators, also for input feed-forward and output current sampling.
On Some Peculiarities of Z-Transformations in Digital Filter Design
Authors: Sekey Andrew A.
Published: May 2015

The paper attempts to elucidate some questions that frequently baffle students:

(1) why do aliasing errors appear after standard z-transformation even with the input signal properly bandlimited? (2) is z = exp( sT) appropriate for determining the frequency response following bilinear z-transformation? (3) what are the consequences on impulse invariant filters of varying the sampling rate?
Toward the Classification of Objectives in Training Technologists and Technicians
Authors: Heywood J.
Published: May 2015

A method for deriving training objectives from the task analysis is described. The derived objectives take into account the attitudes of personnel to themselves, their job training, as well as organizational structure. The cycle of innovation in the firm is related to the demand for, and type of, manpower.
Teaching ‘Design Areas’ En Undergraduate Electronics Courses
Authors: Coward P. R. , Cuthbert L. G.
Published: May 2015

This paper describes the approach taken using the design area technique, in teaching electronics with an emphasis on design, to undergraduates at Queen Mary College. Examples given in this paper are the worst case design of a bias circuit, the simple inverter and the astable multivibrator.
A Study of Attitudes to First Year Undergraduate Electrical Engineering Laboratory Work at the University of Salford
Authors: Carter G. , Lee L. S.
Published: May 2015

The attitudes of first and second year undergraduate students and staff members to first-year laboratory studies were surveyed by interview and questionnaire administration. The most important educational aims of this course and the degree to which achievement of aim occurred have been determined for both student and faculty groups.
An Attempt at Improvement in Undergraduate Teaching
Authors: Andrew R.
Published: May 2015

Poor motivation and response of undergraduate students on a subsidiary engineering course, led to re-organizing the course using supplementary learning material. Condensed lectures were prepared in tape-slide packages for individual or small group use, allowing more informal use of lecture time.

The results and final assessment are described.
Apl in Power Systems Engineering Education
Authors: Grégoire C. , Trécat J.
Published: May 2015

This paper shows how the conversational aspect of APL can be used as a tool to visualize various aspects of the subject, both in teaching and in a power systems laboratory.
An Electronic Three Phase Turbo-Generator Model Suitable for Use in a Hybrid Configuration with a Minicomputer
Authors: Blanch S. E. , Morsztyn K. , Dillon T.
Published: May 2015

This paper describes an electronic model of a three-phase turbogenerator with widely variable parameters. The model is interphased into the Monash TNA to provide a Power System Simulator suitable for statistical investigations of Power System problems. Test results obtained on the model for the ‘Northfleet System’ are also given.
The Educational Thyristor Convertor System (ETCS)
Authors: Arrillaga J. , Rollin L.
Published: May 2015

This describes the layout and performance of a modular thyristor convertor system. It is shown that the model demonstrates the basic principles of rectification and inversion, also the interaction between the supply system and convertor load, and that it provides the basis for numerous experiments and projects at undergraduate and postgraduate levels.
Two Examples in Minicomputer Design
Authors: Majithia J. C. , Banks W. , Jansen J.
Published: May 2015

Two design aspects of minicomputer organization are treated from the viewpoint of a senior undergraduate course. The first is purely serial organization — while the second machine uses a parallel or unibus organization but has the same instructions as the serial machine.

Both these designs have been implemented as student projects and have been used for some additional experiments involving peripherals and interfaces.
A Computer Graphics Demonstration for Teaching Root Locus
Authors: Mee D. H.
Published: May 2015

This paper shows how a computer graphics terminal can be used as an aid to teaching root locus still a powerful method of system synthesis and evaluation, by allowing the student to interact with the program. Sensitivity information is an important by-product of the implementation.
Limitations of the Analogy
Authors: Steven R. E.
Published: May 2015

The analogy appears to be a natural resort of an enquiring mind. Both erroneous and true conclusions can arise when the logic of reasoning is allowed to go beyond the constraints imposed by the terms of reference of the analogy. The paper is intended to encourage debate.
Technology in Art: An Undergraduate Experience
Authors: Gibbons H. J. , Portnoy W. M. , Krauss K. L. , Wood G. B.
Published: May 2015

The results of an experiment in a senior project laboratory are described in which two students and an artist collaborated to obtain a device which was used by the artist to control colors and levels of illumination for a kinetic painting.
State Equations for Electromechanical Systems
Authors: Distler R. J. , Nasar S. A.
Published: May 2015

The state equations for an electromechanical system are formulated and linearized. Both the nonlinear and linear equations are solved numerically for the incremental motion and large motion cases. The various solutions are compared and discussed.
A Note on the Application of Operational Methods to Certain Non-Linear Problems
Authors: Flower J. O.
Published: May 2015

In recent years some effort has been devoted to obtaining approximate analytical solutions to a certain class of non-linear problems using multi-dimensional Laplace transform theory. This note demonstrates that ordinary Laplace transform theory is very often adequate for this task and is, indeed, superior for many problems in this area.
Some Aspects of Undergraduate Digital Electronics and Systems
Authors: Mars P.
Published: May 2015

This paper considers some of the problems involved in the design and implementation of syllabi and support experimental and project activities for undergraduate digital electronics and systems. In particular the influence of rapid developments in integrated circuit technology on fundamental design philosophy and the laboratory/lecture interface is discussed.
A Non-Coherent Pulse Position Modulation System
Authors: Cheung W. N.
Published: May 2015

The article describes a communication system using very simple circuits; the system can easily be assembled in any electronics laboratory and serves the purpose of demonstrating to undergraduates the overall picture of information transmission by PPM.
A Pilot Scheme in Controlled Laboratory Assignments
Authors: Thomas A. F.
Published: May 2015

A procedure is described which enables students to control their own laboratory work. An environment is thereby created which encourages the students to display initiative and take responsibility for their own work. A questionnaire illustrating student reaction and an example of a typical case study are included.
The Analysis of Complex Control Problems: Part 1 the Use of the Graphical Technique
Authors: Arlett P. L. , Vasudeva K. S.
Published: May 2015

A technique for the solution of non-linear feedback problems is presented. The method is graphical and involves no advanced mathematics. It is easily understood and the manual solution of many problems is feasible although the use of a digital computer must be resorted to for more complex systems.
An Approach to the Teaching of Design in Digital Electronics
Authors: Davies E. R.
Published: May 2015

This article describes a new combination of methods which has been used successfully for two years to teach design.in digital electronics. In addition, an analysis is carried out to determine the ingredients more generally required for a training in design, and to indicate what teaching methods might best be used for this purpose.
A Demonstration of Digital Filter Design, Implementation and Testing
Authors: Terrell T. J.
Published: May 2015

The paper presents simple illustrative examples of recursive digital filter design using the bilinear transformation. The effective implementation of the design examples using a digital mini-computer is described. Practical tests and the corresponding results applied to a second order Butterworth low-pass digital filter are presented.
A Modern Introduction to the Fourier Series
Authors: Zygmont Anthony
Published: May 2015

The Fourier series is developed from a function space viewpoint and presented in a packaged tutorial which can be used to supplement any text which introduces the Fourier series. The development is intuitive, geometric, and begins with the definition of a vector as an n-tuple.
An Economical Photomask Processing Scheme for the Small Laboratory
Authors: Jaggers K. A.
Published: May 2015

A system for the rapid and economical production of small quantities of precision masks for photolithography is outlined. The techniques described are especially suited to the wide range of device designs encountered in the small research or teaching laboratory.
A Lecture Package for School Pupils to Promote Electrical Engineering
Authors: Price T. E. , Hately M. C.
Published: May 2015

Career talks form an important part of many school curricula. This article describes a lecture package of particular interest to school-chlidren. It has been successfully used for illustrating the career opportunities in electrical engineering and is based on slides and simple pieces of electrical apparatus which the pupils are able to handle.
Conductor and Tooth Forces in Electrical Machines
Authors: Rhodes David
Published: May 2015

A relatively simple analysis of a basic machine is described which demonstrates how the forces produced by it are shared between the conductors and teeth. The theory is based on energy considerations and is complementary to the genaralized approach to machines often used in undergraduate teaching.
Electronics and the Universities
Authors: Gambling W. A.
Published: May 2015

This is a shortened version of the presidential address given to the Institution of Electronic and Radio Engineers in London in January, 1978.
A Firing Pulse Timer
Authors: Rollin L.
Published: May 2015

A simple device is described which measures the timing and length of gate firing pulses. It employs a principle used in echo sounders and radar, in which the pulses are displayed against a background moving at constant speed.
The Cybercom Multimode Education Communication System
Authors: Lomax Donald
Published: May 2015

The paper describes the use of high-level technology in the lecture theatre. The response of every student in the class can be monitored continuously and corrective feedback can be applied.
A Simple Digital Electronic Simulator
Authors: Kumar Umesh , Suri S. P.
Published: May 2015

A simple electronic circuit is presented which simulates almost any arbitrary waveform as a sequence of rectangular pulses. The synthesis is quite accurate and can be easily effected.
Inadequate Models
Authors: Gaston Jack , Prabhakar Jagdish
Published: May 2015

This paper addresses itself to the problem of inadequate attention often paid to transient and parasitic phenomena in modelling systems and highlights the pitfalls that result thereof. An example from electrical engineering curriculum illustrates the issues involved. Future authors are cautioned against ignoring the transient phenomenon.
A European Electrical Engineering Degree Scheme
Authors: Jones R. E. M. , Evans B. G.
Published: May 2015

This paper reports on a pioneering venture in Electrical Engineering Education; the setting up of a five-year degree scheme for students from West Germany, France and the United Kingdom. The paper outlines the philosophy, objectives and structure of the scheme which starts in October 1980. Details of the planning phase are also given.
Sensitivity Analysis of a Transposed Overhead Line
Authors: Indulkar C. S. , Kumar Pramod , Kothari D. P.
Published: May 2015

In this paper, the method of evaluating the sensitivities of the receiving-end voltage and power to different parameters of an overhead line such as length, spacing, height and frequency for a given sending-end voltage and power is presented. Results for a 220 KV line are given.
Application of Resonant Circuit Theory to Matching Networks
Authors: Armstrong R. , Korolkiewicz E.
Published: May 2015

A wide variety of matching networks are used in high frequency communication systems and this paper shows how such networks can be conveniently designed using the theory of resonant circuits. A graphical method is also included which provides a valuable insight into the properties of the Smith Chart.
An Undergraduate Curriculum for Energy Systems Engineering
Authors: Singh Yash Pal , Rau V. Guru Prasada
Published: May 2015

This paper presents a four-year curriculum for training an ‘energy engineer’. The curriculum is designed to provide a broad-based and integrated training on current as well as emerging energy technologies.
A Technique for Introducing Current Loci
Authors: Cotter G. T.
Published: May 2015

A simple introductory approach to the circle diagram is presented. The desired current locus for a series R — X circuit is obtained with a minimum of algebraic diversion by commencing with Kirchhoff's Voltage Law. Resolution of an apparent contradiction to the student's logical sense is achieved by comparing two cartesian co-ordinate approaches to the mapping of W = 1/ S.
A General Method of Generating Cyclic Codes
Authors: Chan F. H. Y. , Lee Y. W.
Published: May 2015

A general method of generating cyclic codes with the aid of Karnaugh maps is described. It has been used in designing a cyclic coded rotor position transducer. By transposition or inversion of transducer signals, different rotor position settings and directions of rotation are possible without actually repositioning the transducer.
Computer-Aided Design of Digital Systems at Functional Level
Authors: Patnaik L. M. , Dixit U.
Published: May 2015

With the objective of demonstrating the basic concepts of computer-aided design of digital systems, an interactive graphics software package has been implemented. Examples of functional level simulation of control and arithmetic units of a hypothetical computer have been considered at gate and register levels respectively.
The Influence of Power Factor on Turbogenerator Core End Losses — A Simple Physical Explanation
Authors: Newton D. C. , Tavner P. J.
Published: May 2015

The object of this paper is to provide a physical explanation for the variations of stator end region magnetic leakage field, and consequent temperature rises, in a turbogenerator. In particular the paper shows how the losses and temperature rises vary with the power factor and load angle of the turbogenerator.
A Programmable Operational Amplifier for Undergraduate Laboratory Use
Authors: Kehinde L. O.
Published: May 2015

This paper presents two versions of a programmable operational amplifier for undergraduate laboratory use. Using an appropriate combination of switches and impedances, amplification, integration and differentiation are effected by the same operational amplifier. In one version, logical circuitry is used for switching reed relays. Various experimental procedures are suggested.
Laboratory Tests in Electric Heating Processes
Authors: Harry J. E.
Published: May 2015

A series of 15 laboratory tests related to electric heating processes suitable for courses in electric heating and utilisation, or for incorporation in courses on related topics at technician up to postgraduate level. Details of equipment including constructional details where applicable, are given together with the relevant theory.
A Microcomputer-Based S-Plane Transfer Function Plotter
Authors: Cahill S. J.
Published: May 2015

A program for the Commodore 2000/3000/4000 series of microcomputers is presented, to plot S-plane transfer functions in both polynominal and pole-zero forms. Expressions of up to the 9th order are handled. Output is in graphical and tabular form. The program is user-friendly, and may be used by students with a minimum of formal introduction.
Application of the Critical Energy Model for the Calculation of the Corona Onset Voltage in Co-Axial Cables Filled with SF6
Authors: Salama M. M. A.
Published: May 2015

The critical energy model is used to calculate the corona onset voltage in co-axial cable filled with SF6. The calculated values are then compared with the measured corona onset voltages. The paper reports a good agreement between the measured and the calculated corona onset voltages for different co-axial cable dimensions.
A Comparison of Three Active Analogue Band-Pass Filter Circuits
Authors: Newsome J. P.
Published: May 2015

This tutorial paper outlines the design procedure and compares the response of three different forms of active band-pass filter circuit, which are designed to meet the same basic filter specification. The paper shows in particular how the response varies with the spread of operational amplifier gain-bandwidth product; this spread exists, in practice, amongst operational amplifiers of any given type.
A Tailored Learning Package for Multivariable Frequency Response Analysis
Authors: Wilson R. Noel , McCorkell C.
Published: May 2015

The paper describes an interactive multivariable frequency response analysis program, suitable for undergraduate use. Nyquist Array (N.A.) and Inverse Nyquist Array (I.N.A.) design methods are provided, as are a range of graphical displays for system response investigation. Precompensation is available, using several alternative techniques.
The Training of Engineers: Undergraduates' Preferences and Subsequent Experiences in Employment
Authors: Keenan A. , Newton T. J.
Published: May 2015

Final-year undergraduate engineers were asked what kind of training they would like in employment. The same groups were asked one year later about the training they were actually receiving. There were a number of discrepancies between preferences and experiences. Ten per cent were receiving no training and a further twenty per cent claimed their training was not geared toward their institute requirements.
A Microcomputer-Based S-Plane Transient Response Plotter
Authors: Cahill S. J.
Published: May 2015

A CAD package running on the Apple IIe microcomputer is presented to plot the time response of a linear system to a number of forms of excitation. System specification is in either pole-zero or S-plane polynomial, both up to the 9th order. Output is in graphical or tabular form. The programs are user-friendly, and may be used by students with a minimum of formal introduction.
M.Sc Courses in Measurement Science at Manchester
Authors: Taylor H. Rosemary , Payne P. A.
Published: May 2015

Electrical and electronic measuring instruments are used today in all branches of science and engineering. There is a considerable fund of knowledge which is fundamental to all measuring instruments and which will still be valid when today's instruments have been superseded. This one year M.Sc. course aims to teach these fundamentals illustrated by many examples of sensors and instruments used for widely different purposes.
An Introduction to Logic and Fault Simulation
Authors: Menzel S. P.
Published: May 2015

This is an introduction to logic simulation concepts for second or third year undergraduate students in electrical engineering. The motivation, modelling techniques, and algorithms are considered for logic simulation (the verification of the design itself) and fault simulation (the verification of the test for the design).
A Post-Finniston First Year B.Eng. Laboratory Course in Basic Electronics
Authors: Pilkington J. B.
Published: May 2015

The problems encountered in preparing first year B. Eng. students for Engineering Applications practical experience are outlined, and a preliminary practical course to alleviate some of these problems is described. The preliminary practical course is designed to run with a low staff/student ratio.
Test Equipment for Induction Motors
Authors: Leung W. S. , Chan C. C.
Published: May 2015

The paper describes test equipment for measuring the torque of an induction motor over the full range of its speed and for plotting the motor's important torque-speed characteristic on an oscilloscope. The torque sensor is a strain gauge and the test includes the measurement of the switching transient torque.
Algorithms for Limit Cycle Prediction: A Tutorial Paper (for Undergraduates)
Authors: Cox C. S.
Published: May 2015

A technique suggested by Hsu and Meyer for predicting the presence of a limit cycle is presented. Its performance is compared against two conventional methods using a typical undergraduate problem. The paper concludes by illustrating the power of the method by considering a complex electrohydraulic system.
A Phasor Approach to Digital Filters
Authors: Bissell C. C.
Published: May 2015

Expressions for the frequency response of digital filters can be obtained using phasors, in a way very similar to the familiar analysis of simple analogue networks. These expressions can then be generalized as an informal route to the z-plane, pole-zero filter specification, and even the z-transform of sample sequences.
STIE — A Tool for Studying Image Processing
Authors: Robinson N. J. , Thomas R.
Published: May 2015

STIE (Softward Tool for Image Experimentation) allows a student to study interactively the fundamental methods for performing Image Processing. A number of different algorithms have been incorporated and expansion is possible within a clearly defined structure.
The Initial Conditions Problem
Authors: Vibet C.
Published: May 2015

Based on control theory, a new method to investigate initial conditions induced by the application of a step command on linear or nonlinear systems is given in this paper. Examples are provided to illustrate the proposed method.
Teaching Electromagnetics through Finite Elements. Part 2: The Instructional Program
Authors: Hoole S. Ratnajeevan H. , Hoole P. Ratnamahilan P. , Jayakumaran S. , Hoole N. Ratnasuneeran G.
Published: May 2015

A finite element program for use in the instruction of electromagnetic field theory is described. The unity among the various disciplines of physics through the Poisson equation is exploited to make the same program solve problems from many areas. Graphics menus and adaptive mesh generation capabilities are provided to make the program easily usable by the uninitiated student.
The Application of Constrained Signal Reconstruction Methods in High Voltage Impulse Measurement
Authors: Nagasaka D. M. , Raghuveer M. R.
Published: May 2015

Two methods of signal reconstruction — the constrained iterative reconstruction method (CIR) and the constrained least squares reconstruction method (CLSR) have been used to compensate for the inadequate response of two high voltage impulse measuring systems. Both methods have been shown to produce accurate estimates. However, the CIR method is favoured as it produces stable results under all of the presented conditions.
A First-Year Practical Exercise in the Design and Construction of a Simple Microprocessor-Based Measurement System
Authors: Paull C. J.
Published: May 2015

The paper describes a first year project introducing practical aspects of work with electronic circuits. A simple Z80-based microcontroller forms the core of the system and students themselves design the analogue interface necessary to link this to a specified transducer.
The Introduction of Electronics Computer Aided Design Facilities to Engineering Science Students
Authors: Cobley Rosemary A.
Published: May 2015

The impact made by professional electronic CAD tools and engineering workstations, upon undergraduate courses in the department, is outlined. Student groups have successfully designed, simulated and tested digital systems, which had been implemented as gate arrays. The interest throughout the department has highlighted areas for integrated mechanical/electronic projects.
The Use of Ella in Teaching and Research
Authors: Pearmain A. J. , Razi A. R. , Coward P. R.
Published: May 2015

The ELLA hardware description language and simulator are used at Queen Mary College in a final-year course where students simulate the specification of a design to verify the correctness of the specification and the definitions of the design partitions. Research use is in evaluating alternative parallel architectures for signal processing.
Using Ella as a Design Tool
Authors: Miller P. R. , Zwolinski M. , Jesshope C. R.
Published: May 2015

An overview of the ELLA system is given, followed by a description of how it has been used as an architectural tool to develop packet-switching networks for SIMD processor arrays. Finally, the merits and drawbacks of ELLA are discussed, with a summary on current trends in automated design.
Computer Aided Design of Systems at Functional Level
Authors: Deans N. D. , Chalmers S. J. , Paterson C. , Jutagir A.
Published: May 2015

Existing CAD tools are largely used to examine and verify the behaviour of circuits already designed by engineers. This paper describes high-level behavioural modelling facilities developed to simulate algorithmic state machines and digital signal processing systems and so confirm their behaviour before detailed circuit design work is undertaken.
Electronic Engineering and Mathematics: A New Joint Honours Undergraduate Degree Course
Authors: Faulkner T. R.
Published: May 2015

Electronic engineering requires a variety of sophisticated mathematical techniques and graduates entering this profession must not only understand these techniques but be able to develop their own mathematical expertise as new problems unfold. This paper is a description of a new undergraduate course designed to produce such graduates.
Real-Time Implementation of a Recursive Sliding Spectral Estimator Using a TMS 32010 Microprocessor
Authors: Campbell D. R. , Bradshaw S.
Published: May 2015

An undergraduate project to apply the Texas Instruments TMS 32010 to real-time sliding spectral measurement is described. A recursive Fourier transform for real sequences is employed because of its algorithmic simplicity and results from a practical implementation are presented.
A Laboratory Experiment Introducing Fault Diagnosis in Analogue and Digital Circuits
Authors: Paull C. J.
Published: May 2015

The paper describes an experiment designed to introduce students to fault diagnosis in analogue and digital circuits. The faults are randomly selected and results can be checked against look-up tables available to the laboratory supervisor.