bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effects of Nicotine on Attention, Information Processing, and Short-Term Memory in Patients with Dementia of the Alzheimer Type
Authors: Sahakian Barbara , Jones Gemma , Levy Raymond , Gray Jeffrey , Warburton David
Published: August 2008

Nicotine in patients with dementia of the Alzheimer type (DAT) producted a significant and marked improvement in discriminative sensitivity and reaction times on a computerised test of attention and information processing. Nicotine also improved the ability of DAT patients to detect a flickering light in a critical flicker fusion test. These results suggest that nicotine may be acting on cortical mechanisms involved in visual perception and attention, and support the hypothesis that acetylcholine transmission modulates vigilance and discrimination. Nicotine may therefore be of some value in treating deficits in attention and information processing in DAT patients.
1. Psychiatric Justice
Authors: Szasz Thomas
Published: August 2008

It is now widely accepted, especially in the United States, that confining lawbreakers in mental hospitals as insane, without the benefit of a real trial, rather in prisons as criminals, after a proper trial, is a recent, enlightened Western practice. Nothing could be further from the truth. The practice is not recent, enlightened, or typically Western – resembling the Oriental despotic arbitrariness towards troublesome persons much more closely than the Occidental legal respect towards persons accused of crimes. Many 19th-century cases illustrate the procedure and support my foregoing interpretation of it. The following is a typical example.
Tardive Dyskinesia in Bipolar Affective Disorder: Relationship to Lithium Therapy
Authors: Dinan Timothy G. , Kohen Dora
Published: August 2008

Forty patients under the age of 60 years with a DSM–III diagnosis of bipolar affective disorder were examined for the presence of tardive dyskinesia. The overall prevalence was 22.5%, with an age-related increase. Patients with and without tardive dyskinesia did not differ in terms of duration of affective illness or exposure to neuroleptics, but those patients with tardive dyskinesia had significantly more psychiatric admissions and were on lithium for significantly greater lengths of time.
Epilepsy and Violence
Authors: Hindler C. G.
Published: August 2008

Epileptic automatism and violence are seldom found among temporal lobe epileptics. The case of a 19-year-old girl who killed a 20-month-old child during an epileptic attack is described, and the literature and medico-legal issues are briefly reviewed.
A Case of Doll Phobia
Authors: Hatcher Simon
Published: August 2008

A case of doll phobia in a 14-year-old boy is presented and discussed.
Neuroleptic Malignant Syndrome in a Case of Post-Partum Psychosis
Authors: Price D. K. , Turnbull G. J. , Gregory R. P. , Stevens D. G.
Published: August 2008

A 27-year-old woman with a post-partum psychosis developed NMS which proved difficult to diagnose because of the organic features of the presenting illness. Possible contributory factors to the development of NMS included exhaustion, a non-specific viral illness, and rapid loading with haloperidol.
Genital Self-mutilation: Attempted Foreskin Reconstruction
Authors: Walter Garry , Streimer Jeffrey
Published: August 2008

A non-psychotic adult attempted surgically to reconstruct a foreskin for himself. The patient's membership of an organisation which lobbies against circumcision was contributory.
Psychosocial Predictors of Psychopathology in Epilepsy
Authors: Hermann Bruce P. , Whitman Steven , Wyler Allen R. , Anton Michael T. , Vanderzwagg Roger
Published: August 2008

The 30-item version of the GHQ was administered to 102 adults with epilepsy, and four sets of variables (neurological, psychosocial, medication, demographic) were used to predict psychiatric distress. Psychopathology was found to be associated with increased perceived stigma, elevated number of stressful life events during the past year, poor adjustment to epilepsy, financial stress, vocational problems, external locus of control, and an earlier onset of epilepsy. Multiple regression procedures reduced this list to three independent predictors of psychopathology: an increased number of stressful life events in the past year, poor adjustment to epilepsy, and financial stress.
Some Observations on the Supervision of Dangerous Offender Patients
Authors: Prins Herschel
Published: August 2008

“All tragedy is the failure of communication”

(Wilson, 1956)

From time to time, general psychiatrists are asked to supervise offender patients who have been conditionally discharged into the community either by direction of the Home Secretary or by a Mental Health Review Tribunal (Mental Health Act 1983, sections 42(2) and 73(2)(4b)). In addition, they may be asked occasionally to provide psychiatric management for offenders released by the Home Secretary on life licence (Criminal Justice Act 1967, section 61). The effect of a conditional discharge following compulsory admission to hospital care by a court under a restriction order (Mental Health Act 1983, sections 37/41) is similar to that of a life licence.
Re-examination of the Language of Psychotic Subjects
Authors: King K. , Fraser W. I. , Thomas P. , Kendell R. E.
Published: August 2008

To investigate whether language in schizophrenia deteriorated progressively, 11 schizophrenic subjects, 9 manic subjects and 9 controls were re-tested after an interval of three years using the computer-assisted syntactical analysis technique of Morice. In 13 of the 16 linguistic variables described as hallmarks of schizophrenic speech decline, deterioration was noted in schizophrenics in the direction predicted and relative to the manic and control groups. The deterioration was most pronounced in complexity and integrity of speech. One variable remained unchanged and two (semantic variables) showed marginal improvement. It was concluded that language, and in particular syntax, does deteriorate in the schizophrenic process.
Personality Disorder and Psychiatric Illness in General Practice
Authors: Casey Patricia R. , Tyrer Peter
Published: August 2008

In a one-year prevalence study of conspicuous psychiatric morbidity in two group general practices, one urban and the other rural, personality disorder was diagnosed in 5.3% by the GP and in 5.6% by the psychiatrist, but this increased to 28% when personality disorder was assessed using a structured interview. The prevalence of personality disorder was higher in the urban practice than in the rural one but there was no consistent association between personality disorder and mental state disorder, with the exception of alcohol abuse and dependence. The high rate of personality disorder found using the interview schedule is likely to be a true finding, and failure to recognise this hidden morbidity is important in both general and psychiatric practice.
Coexistence of the Capgras and de Clérambault's Syndromes
Authors: O'Dwyer J. M.
Published: August 2008

A patient with a paranoid schizophrenic illness showed features of two rare syndromes, Capgras and de Clérambault's.
The Influence of Social Factors on Common Mental Disorders
Authors: Goldberg David , Bridges Keith , Cook Diane , Evans Barbara , Grayson David
Published: August 2008

This study distinguishes between processes that cause individuals to experience symptoms – destabilisation – and those that are associated with loss of symptoms over time – restitution. It is shown that different clinical, social, and personality variables are associated with each of these processes. Where destabilisation is concerned, it is shown that different variables were associated with the development of symptoms of anxiety and those of depression. Different variables were associated with restitution, and they did not show the same relationship with the symptom dimensions of anxiety and depression as those which were associated with destabilisation.
Vitamin Deficiency and Mental Symptoms
Authors: Carney M. W. P.
Published: August 2008

Recently, research into the connection between vitamins and psychiatric disorder, particularly affective changes, has been in the doldrums, with the exceptions perhaps of studies of folic acid and pyridoxine. The best way for research to proceed is first to establish that the association of a vitamin deficiency with a psychiatric disorder is beyond a chance finding. Then, questions should be asked about what mental symptoms it is linked with, and what the other associations (malnutrition, drugs, physical illness, etc) are. Lastly, queries should be raised about whether the association is causal or if the mental symptoms are merely secondary to the anorexia and poor diet so common in mental illness (or whether they are linked in a vicious circle as suggested by Reynoldset al(1971)). These questions became pertinent in the mid-1960s when reliable ways of assaying B vitamins such as folic acid became more generally available. In this review, I present evidence that deficiencies of folic acid, B12, thiamine, riboflavin, pyridoxine and ascorbic acid are not infrequently found in psychiatric practice. It should be remembered, however, that some ways of assaying vitamins are liable to give a larger proportion of spurious low results than other methods (false positives), although the adoption of more reliable ways of assaying vitamins should reduce this.
Erotomania in Relation to Childbirth
Authors: Murray Declan , Harwood Peter , Eapen Elza
Published: August 2008

A case of erotomania in relation to childbirth is reported. There was a good response to treatment and no evidence of relapse at 18-month follow-up.
Altered Magnetic Resonance White-Matter T1 Values in Patients with Affective Disorder
Authors: Dolan R. J. , Poynton A. M. , Bridges P. K. , Trimble M. R.
Published: August 2008

The MRI T1 proton relaxation values were assessed in 14 patients with bipolar affective disorder and 10 with a unipolar disorder and a matched normal control group. The T1 values in the frontal white matter of patients significantly exceeded those of the controls. This difference was accounted for by an increase in T1 values in the frontal white matter of unipolar patients: the values for bipolar patients alone did not differ from those for controls. These preliminary findings support a hypothesis of frontal lobe dysfunction mediating pathological changes in mood.
DSM–HI: From Left to Right or from Right to Left?
Authors: Birley J. L. T.
Published: August 2008

DSM–III has largely been based upon essentialist notions of increasingly accurate and ‘valid’ definitions of diseases. A nominalist approach would facilitate study of aetiological factors and variables in the natural history of diseases.
Classifying Depression by Mental State Signs
Authors: Parker Gordon , Hadzi-Pavlovic Dusan , Boyce Philip , Wilhelm Kay , Brodaty Henry , Mitchell Philip , Hickie Ian , Eyers Kerrie
Published: August 2008

The possibility that separation of a categorical depressive disease (‘melancholia’) from remaining depressive disorders can be improved by assessment of mental state signs was examined in patients treated by representative Sydney psychiatrists and patients referred to a specialised mood disorders unit. A set of signs, principally assessing retardation, was derived within the two samples by principal-components and latent-class analyses. Scores were significantly correlated with clinical, DSM–III, and RDC diagnoses, and appeared independent of severity, suggesting that melancholia can be defined phenomenologically. Scores were also associated with several ‘validating’ factors. Comparative analyses of a refined list of melancholia symptoms suggested that ratings of defined signs are likely to have greater capacity than symptom ratings to differentiate melancholia from residual depressive disorders.
A Controlled Study of Psychological and Social Change after Surgical Gender Reassignment in Selected Male Transsexuals
Authors: Mate-Kole Charles , Freschi Maurizio , Robin Ashley
Published: August 2008

Of two groups of 20 patients accepted for gender reassignment surgery, one was offered early operation and therefore had had surgery by follow-up two years later, while the second was still awaiting operation at two-year follow-up. Although the groups were similar initially, significant differences between them emerged at follow-up in terms of neuroticism and social and sexual activity, with benefits being enjoyed by the operated group.
Structure and Function in Neurology and Psychiatry
Authors: Reynolds E. H.
Published: August 2008

In the 19th century the triumphs of neuropathology and the clinico-anatomical method led to the evolution of neurology as a separate ‘organically’ based discipline associated with the concept of functional localisation. At the same time the growth of psychodynamic psychiatry contributed to the progressive separation of the two disciplines, with neuropsychiatry sitting uneasily in the middle. Psychiatrists are now showing increasing interest in the structure and function of the nervous system, but are having difficulty in integrating their findings into ‘functional’ diseases. This may be because disorder of function in the nervous system is much more complex than previously envisaged. The function of the nervous system is profoundly affected by psychological and social factors. The view that neurology is wholly ‘organic’ and synonymous with structural disease of the nervous system is fallacious. Neurological patients have complex dynamic disorders of function in the nervous system whether or not structural disease is present.
Suicide in England and Wales and in Scotland
Authors: Crombie Iain K.
Published: August 2008

The suicide rates in England and Wales and Scotland converged during the late 1960s, and from 1970 were higher in Scotland. The convergence occurred because of differences in the falls in rates of those aged over 45 years and not because of differences in frequency and decline of coal gas suicide. Male suicide increased more rapidly in Scotland during the 1970s. In England and Wales overall female suicide rates fell during 1958–76 whereas in Scotland there was no clear trend. Suicide by car exhaust increased similarly in both countries, but that by hanging and drug poisoning increased more rapidly in Scotland.
Hormonal Responses to Fenfluramine in Depressive Subtypes
Authors: Mitchell Philip , Smythe George , Parker Gordon , Wilhelm Kay , Hickie Ian , Brodaty Henry , Boyce Philip
Published: August 2008

In order to study putative differences in central neurotransmitter function in depressive subtypes, serum Cortisol and prolactin responses to the putative serotonin agonist fenfluramine were examined in 30 subjects with major depression. Patients with endogenous depression (melancholia) as defined by each of ICD–9, DSM–III, RDC and Newcastle scale demonstrated a reduced prolactin response to 60 mg oral fenfluramine when compared with non-endogenous subjects. This was independent of either prolactin or Cortisol baseline levels, and indicates that there are differences in brain neurotransmitter function in the endogenous and non-endogenous subtypes of depression. Basal prolactin levels were reduced in bipolar compared with unipolar subjects, and delusional compared with non-delusional patients, although there were no differences in the prolactin responses to fenfluramine between these subgroups. Basal Cortisol levels and Cortisol response to fenfluramine did not distinguish between any of the subtypes.
The TAPS Project. 3: Predicting the Community Costs of Closing Psychiatric Hospitals
Authors: Knapp Martin , Beecham Jeni , Anderson Jeremy , Dayson David , Leff Julian , Margolius Olga , O'driscoll Cathie , Wills Walter
Published: August 2008

The planning of long-term care in the community as an alternative to in-patient care requires accurate information on the likely expense of altering the balance of provision. Unfortunately, as very few long-stay psychiatric hospitals have yet closed, the planning of these resource requirements has had to proceed in a vacuum. By examining the costs of community reprovision for the first 136 people to leave Claybury and Friern Hospitals, a prediction equation has been estimated from existing data which links the hospital-assessed characteristics (including psychiatric symptoms and behavioural problems) of these people to the subsequent cost of community care. About a third of the observed variation in these costs can be explained statistically by these ‘baseline’ characteristics. However, the first cohorts exhibit fewer behavioural problems and other symptoms of mental illness, they have been in hospital for shorter lengths of time, and they are younger. The prediction equation for the leavers is thus used to extrapolate community costs for those hospital residents yet to leave. It is found that community costs are lower than hospital costs, not just for the first cohorts of leavers, but for the full populations of the two hospitals scheduled to close.
Chronically Ill Psychiatric Patients in a District General Hospital Unit a Survey and Two-Year Follow-Up in an Inner-London Health District
Authors: O'driscoll Catherine , Marshall Jane , Reed John
Published: August 2008

A survey was undertaken at the end of 1984 of all patients occupying psychiatric beds for more than six months in an inner-London health district. Excluding those with senile dementia, 30 patients were identified. Two years later, a follow-up survey traced the original cohort and the accumulation of additional patients on the wards. The finding that the rate of discharge from the original group matches the accumulation of new patients into the survey suggests a need for new types of community provision within the district.
Neurological Soft Signs in Schizophrenia
Authors: Rossi A. , De Cataldo S. , Di Michele V. , Manna V. , Ceccoli S. , Stratta P. , Casacchia M.
Published: August 2008

A standardised clinical examination which focused on neurological soft signs (NSS) was used by a neurologist blind to diagnosis to assess the presence of neurological soft signs. A comparison of NSS score was made among three groups of subjects consisting of 58 DSM–III schizophrenics, 31 of their healthy first-degree relatives and 38 normal controls. The schizophrenic group had significantly higher NSS total scores than normal controls but did not differ significantly from their first-degree relatives' group. The relatives' group showed higher NSS total scores than did normal controls although to a lesser extent than schizophrenics.
Acute Blocking of Naloxone-Precipitated Opiate Withdrawal Symptoms by Methohexitone
Authors: Loimer N. , Schmid R. , Lenz K. , Presslich O. , Grünberger J.
Published: August 2008

In a double-blind placebo-controlled trial of 18 patients, methohexitone blocked objective signs of opiate withdrawal caused by a bolus injection of naloxone. Furthermore, in continuing the naloxone therapy for 48 hours, no withdrawal signs appeared. Levels of withdrawal distress returned to normal levels within six days. This approach can be regarded as an effective and well tolerated withdrawal therapy with low drop-out rates.
Neuroleptic-Induced Priapism, Hepatotoxicity and Subsequent Impotence in a Patient with Depressive Psychosis
Authors: Chen Eric Y. H. , Lee Alan S.
Published: August 2008

A 59–year-old man experienced priapism five days after taking neuroleptics and abnormal liver function after 28 days. These side-effects are possibly explained as hypersensitivity reactions to the drug.
Do Available Questionnaires Measure the Communication Factors That Patients and Families Consider Important at End of Life?
Authors: Grunfeld Eva , Folkes Amy , Urquhart Robin
Published: August 2008

Patients with advanced cancer report wanting better communication. Our previous research identified five specific communication domains important to end-of-life (EOL) cancer care: communicating information, interpersonal communication, communicating available supportive care services, communicating a transition in the objectives of care, and interprofessional communication. A literature review was conducted to identify patient-, family member–, or heath professional–reported questionnaires to measure these specific communication domains. On the basis of specific criteria, including validity and evidence base, 10 questionnaires were identified that have the potential to measure and monitor the quality of communication during EOL cancer care. No single questionnaire measured all five domains. There is a need to further develop questionnaires that have the capacity to specifically measure those communication domains that are important to patients with cancer and their families at EOL.
Symptom Assessment in Palliative Care: A Need for International Collaboration
Authors: Kaasa Stein , Loge Jon Håvard , Fayers Peter , Caraceni Augusto , Strasser Florian , Hjermstad Marianne Jensen , Higginson Irene , Radbruch Lukas , Haugen Dagny Faksvåg
Published: August 2008

This article describes the research strategy for the development of a computerized assessment tool as part of a European Union (EU)–funded project, the European Palliative Care Research Collaborative (EPCRC). The EPCRC is funded through the Sixth Framework Program of the EU with major objectives to develop a computer-based assessment and classification tool for pain, depression, and cachexia. A systematic approach will be applied for the tool development with emphasis on multicultural and multilanguage challenges across Europe. The EPCRC is based on a long lasting collaboration within the European Association for Palliative Care Research Network. The ongoing change in society towards greatly increased use of communication as well as information transfer via digital systems will rapidly change the health care system. Therefore, patient-centered outcome assessment tools applicable for both clinic and research should be developed. Report of symptoms via digital media provides a start for face-to-face communication, treatment decisions, and assessment of treatment effects. The increased use of electronic media for exchange of information may facilitate the development and use of electronic assessment tools and decision-making systems in oncology. In the future, patients may find that a combination of a face-to-face interview plus a transfer of information of subjective symptoms by electronic means will optimize treatment.
Evidence-Based Recommendations for Information and Care Planning in Cancer Care
Authors: Walling Anne , Lorenz Karl A. , Dy Sydney M. , Naeim Arash , Sanati Homayoon , Asch Steven M. , Wenger Neil S.
Published: August 2008

The practice of oncology is characterized by challenging communication tasks that make it difficult to ensure optimal physician-patient information sharing and care planning. Discussions of diagnosis, prognosis, and patient goals are essential processes that inform decisions. However, data suggest that there are deficiencies in this area. We conducted a systematic review to identify the evidence supporting high-quality clinical practices for information and care planning in the context of cancer care as part of the RAND Cancer Quality–Assessing Symptoms, Side Effects, and Indicators of Supportive Treatment Project. Domains of information and care planning that are important for high-quality cancer care include integration of palliation into cancer care, advance care planning, sentinel events as markers for the need to readdress a patient's goals of care, and continuity of care planning. The standards presented here for information and care planning in cancer care should be incorporated into care pathways and should become the expectation rather than the exception.
Is It Feasible and Desirable to Collect Voluntarily Quality and Outcome Data Nationally in Palliative Oncology Care?
Authors: Currow David C. , Eagar Kathy , Aoun Samar , Fildes Dave , Yates Patsy , Kristjanson Linda J.
Published: August 2008

Hospice/palliative care is a critical component of cancer care. In Australia, more than 85% of people referred to specialized hospice/palliative care services (SHPCS) have a primary diagnosis of cancer, and 60% of people who die from cancer will be referred to SHPCS. The Palliative Care Outcomes Collaboration (PCOC) is an Australian initiative that allows SHPCS to collect nationally agreed-upon measures to better understand quality, safety, and outcomes of care. This article describes data (October 2006 through September 2007) from the first 22 SHPCS, with more than 100 inpatient admissions annually. Data include phase of illness, place of discharge, and, at each transition in place of care, the person's functional status, dependency, and symptom scores. Data are available for 5,395 people for 6,379 admissions. After categorizing by phase of illness and dependency, there remain at the end of each admission 12-fold differences (mean, 26%; range, 4% to 52%) in the percentage of patients who became stable after an unstable phase; seven-fold differences (mean, 22%; range, 6% to 41%) in the percentage of patients with improved symptom scores, five-fold differences (mean, 25%; range, 12% to 64%) in discharge back to the community, four-fold differences (mean, 10%; range, 4% to 16%) in improved function, and three-fold differences in the length of stay (mean, 14 days; range, 6 to 19 days). PCOC shows it is feasible to collect quality national palliative care outcome data voluntarily. Variations in outcomes justify continued enrollment of services. Benchmarking should include all patients whose cancer will cause death and explore observed variations.
Nationwide Veterans Affairs Quality Measure for Cancer: The Family Assessment of Treatment at End of Life
Authors: Finlay Esme , Shreve Scott , Casarett David
Published: August 2008

The Veterans Affairs (VA) health care system has created a national initiative to measure quality of care at the end of life. This article describes the first phase of this national initiative, the Family Assessment of Treatment at End of Life (FATE), in evaluating the quality of end-of-life care for veterans dying with cancer. In the initial phase, next of kin of patients from five VA Medical Centers were contacted 6 weeks after patients' deaths and invited to participate in a telephone interview, and surrogates for 262 cancer patients completed FATE interviews. Decedents were 98% male with an average age of 72 years. There was substantial variation among sites. Higher FATE scores, consistent with family reports of higher satisfaction with care, were associated with palliative care consultation and hospice referral and having a Do Not Resuscitate order at the time of death, whereas an intensive care unit death was associated with lower scores. Early experience with FATE suggests that it will be a helpful tool to characterize end-of-life cancer care and to identify targets for quality improvement.
Non-cell-autonomous effects ofRetdeletion in early enteric neurogenesis
Authors: Bogni Silvia , Trainor Paul , Natarajan Dipa , Krumlauf Robb , Pachnis Vassilis
Published: August 2008

Neural crest cells (NCCs) form at the dorsal margin of the neural tube and migrate along distinct pathways throughout the vertebrate embryo to generate multiple cell types. A subpopulation of vagal NCCs invades the foregut and colonises the entire gastrointestinal tract to form the enteric nervous system(ENS). The colonisation of embryonic gut by NCCs has been studied extensively in chick embryos, and genetic studies in mice have identified genes crucial for ENS development, including Ret. Here, we have combined mouse embryo and organotypic gut culture to monitor and experimentally manipulate the progenitors of the ENS. Using this system, we demonstrate that lineally marked intestinal ENS progenitors from E11.5 mouse embryos grafted into the early vagal NCC pathway of E8.5 embryos colonise the entire length of the gastrointestinal tract. By contrast, similar progenitors transplanted into Ret-deficient host embryos are restricted to the proximal foregut. Our findings establish an experimental system that can be used to explore the interactions of NCCs with their cellular environment and reveal a previously unrecognised non-cell-autonomous effect of Ret deletion on ENS development.
Analytical model for characterizing the pear-shaped tribotest for tube hydroforming. Part 1
Authors: Ngaile G , Yang C
Published: August 2008

An analytical model to characterize the pear-shaped tribotest is presented. In this test, a tubular specimen is pressurized, forcing the material to flow towards the apex of a pear-shaped die. The height of the pear-shaped tube is a function of the magnitude of friction stress at the tube—die interface. Through a mechanistic approach, a closed-form solution for field variables die—tube contact pressure, effective stress/strain, longitudinal stress/strain, and hoop stress/strain can be computed as a function of input pressure loading. The model has been validated by finite element analysis. The closed-form solution can be used rapidly to establish the calibration curves for determination of friction coefficient in the pear-shaped tribotest. Of equal importance, the analytical model can be used to optimize both process and die geometric variables to suit specific needs such as die wear studies through monitoring local interface pressure loading, types of material to be tested, tube sizes, and so on. Details on the applications of the developed analytical model can be found in Part 2 of this paper.
Applications of analytical model for characterizing the pear-shaped tribotest for tube hydroforming. Part 2
Authors: Ngaile G , Yang C
Published: August 2008

Applications of the analytical model for characterizing the pear-shaped tribotest are presented. Details on the derivations of the analytical model can be found in Part 1 of this paper (published in Proceedings of the Institution of Mechanical Engineers, Journal of Engineering Manufacture, 2008, Vol. 222). In this test, a tubular specimen is pressurized, forcing the material to flow towards the apex of a pear-shaped die. The height of the pear-shaped tube is a function of the magnitude of friction stress at the tube—die interface. The analytical model is used rapidly to establish the calibration curves for determination of friction coefficient in the pear-shaped tribotest. The model is also used to optimize both process and die geometric variables to suit specific tribological needs. The paper presents examples of how optimal pear-shape tribotest conditions pertaining to die geometry, tubular material properties, tube sizes, and pressure loading can be achieved via this model.
Laser burnishing method for surface layer modification
Authors: Radziejewska J , Nowicki B , Kalita W
Published: August 2008

The results of experiments on the application of a new hybrid method that combines laser melting treatment with burnishing in hot conditions are presented. Both treatments were performed on the laser station in one operation. The experiments were done on carbon steel C45. The process was performed with a CO2 laser of 2.5 kW maximum power at different parameters. Experiments on the influence of burnishing process parameters on surface layer properties were conducted. The results of measuring the roughness, microstructure, and microhardness of the surface layer after laser hardening and after laser hardening combined with microhammering are presented. The microhammering treatment leads to a decrease in surface roughness of about 40 per cent, compared with laser hardening alone. Neither cracks nor spallings were observed. Microstructural analysis has shown that the burnishing process causes deformation of grains and increased microhardness of the material of the surface zone.
Modelling and predicting surface roughness in turning operations using hybrid differential evolution and the group method of data handling networks
Authors: Onwubolu G C
Published: August 2008

This paper presents a hybrid modelling approach, based on the group method of data handling (GMDH) and the differential evolution (DE) population-based algorithm, for modelling and predicting surface roughness in turning operations. Turning operations have been performed on a mild steel workpiece with a high-speed steel (HSS) tool over a wide range of cutting conditions. The results of the hybrid DE—GMDH approach are compared with the results obtained by the standard GMDH algorithm and its variants. Three case studies were examined, from which it can be concluded that the DE—GMDH algorithm generalizes best (based on the EPI value) when the input variables include the cutting conditions of speed, feed, and depth of cut, as well as the feed force and cutting force. Results presented show that the proposed DE—GMDH algorithm appears to perform better than the standard GMDH algorithm and the polynomial neural network (PNN) model for the surface roughness problem. Consequently, such a self-organizing modelling approach is useful in both modelling and prediction in an advanced manufacturing system where it is necessary to model and predict the surface roughness during machining operations. Application of such heuristics can play a major role in reducing production costs.
Improvement of the connection force in the hydro-embedding process
Authors: Kwon S O , Kim B J , Kim D K , Moon Y H
Published: August 2008

The applicability and productivity of the hydroforming process can be increased by combining pre- and post-forming processes such as bending, piercing, and embedding. For the fabrication of structural parts, hollow bodies with connecting nuts are widely used to connect parts together. It usually requires multiple steps and devices for welding and/or screwing. Therefore, the hydro-embedding process, which combines hydraulic embedding of the connection element with the hydroforming process, is investigated in this study. To increase the connection force, the authors focus on the optimization of the shape of the connection element and rotational embedding of the connection element. The effects of the shape of the screw tip, the screw thread, and the thread shape on the connection force have been investigated, and the optimal shape of the connection element has been determined. To estimate the effect of rotational embedding of the connection element, a trial process has been successfully implemented in this study and an increased connection force has been achieved.
Influence of process parameters on electric discharge machining of WC/30%Co composites
Authors: Kanagarajan D , Karthikeyan R , Palanikumar K , Sivaraj P
Published: August 2008

Tungsten carbide/cobalt (WC/Co) cemented carbide is one of the important composite materials that are used in the manufacture of cutting tools, dies, and other special tools. It has high hardness and excellent resistance to shock and wear, and is not possible to machine easily using conventional techniques. WC/Co cemented carbide produced through powder metallurgy is subjected to electro discharge machining (EDM). In this study four design factors: electrode rotation (S), pulse on time (T), current (A), and flushing pressure (P) of EDM, were chosen as variables in order to study the process performance in terms of material removal rate (MRR) and surface roughness ( Ra). The experiments were performed on a newly designed experimental set-up developed in the laboratory. The response surface methodology is used to identify the most influential parameters for maximizing metal removal rate and for minimizing the surface roughness. The recommended optimal process conditions have been verified by conducting confirmation experiments. The experimental results are used to develop the statistical models based on the second-order polynomial equations for the different process characteristics.
Performance evaluation of flexible manufacturing systems under uncertain and dynamic situations
Authors: Kumar V , Kumar S , Tiwari M K , Chan F
Published: August 2008

The present era demands the efficient modelling of any manufacturing system to enable it to cope with unforeseen situations on the shop floor. One of the complex issues affecting the performance of manufacturing systems is the scheduling of part types. In this paper, the authors have attempted to overcome the impact of uncertainties such as machine breakdowns, deadlocks, etc., by inserting slack that can absorb these disruptions without affecting the other scheduled activities. The impact of the flexibilities in this scenario is also investigated. The objective functions have been formulated in such a manner that a better trade-off between the uncertainties and flexibilities can be established. Consideration of automated guided vehicles (AGVs) in this scenario helps in the loading or unloading of part types in a better manner. In the recent past, a comprehensive literature survey revealed the supremacy of random search algorithms in evaluating the performance of these types of dynamic manufacturing system. The authors have used a metaheuristic known as the quick convergence simulated annealing (QCSA) algorithm, and employed it to resolve the dynamic manufacturing scenario. The metaheuristic encompasses a Cauchy distribution function as a probability function that helps in escaping the local minima in a better manner. Various machine breakdown scenarios are generated. A ‘heuristic gap’ is measured, and it indicates the effectiveness of the performance of the proposed methodology with the varying problem complexities. Statistical validation is also carried out, which helps in authenticating the effectiveness of the proposed approach. The efficacy of the proposed approach is also compared with deterministic priority rules.
Fundamental optimal relation of a generalized irreversible four-reservoir chemical pump
Authors: Chen L , Xia D , Sun F
Published: August 2008

A new cyclic model of a four-reservoir chemical pump with irreversible mass transfer, mass leakage, and internal dissipation is proposed in this paper. The optimal relation between the coefficient of performance (COP) and the rate of energy pumping of the generalized irreversible four-reservoir chemical pump is derived by using finite-time thermodynamics or thermodynamic optimization. The maximum COP and the corresponding rate of energy pumping, as well as the optimal time parameters of the four mass transfer processes and the optimal chemical potentials of the working fluid are also obtained. Moreover, the influences of these irreversibilities on the optimal performance of the chemical pump are revealed. It is found that the mass leakage affects the optimal performance qualitatively, and the characteristic curve changes from a monotonic decreasing function without mass leakage to a parabolic-like one with mass leakage; while the internal dissipation affects the optimal performance quantitatively, it does not change the shape of the characteristic curve but only decreases the peak value. The results obtained herein can provide some new theoretical guidelines for the optimal design and development of a class of chemical pumps.
A new formulation based upon trigonometric function for finite circular arch elements
Authors: Saffari H , Fadaee M J , Tabatabaei R
Published: August 2008

In this paper, the formulation of the curved beam element by trigonometric functions for the curvature, which is an alternative to the displacement function is presented. Trigonometric function is chosen for the curvature to avoid the shear and membrane locking phenomena. In the developed formulation, the force—curvature relationships in polar coordinate system have been obtained first; then the curvature of the element has been assumed to have a trigonometric function form; and the radial and tangential displacements, and rotation of the cross-section have been found to be a function of the curvature. Moreover, the relationship between the nodal curvatures and the nodal deformations has been calculated and used for determining the deformations in terms of curvature at an arbitrary point. The total potential energy has been calculated accounting for bending, shear, and tangential deformations. Invoking the stationary condition of the system, the force—deformation relationship for the element has been obtained. Using this relationship, the stiffness matrix and the equivalent fixed loads applying at the nodes have been computed. In such an equilibrium equation, the locking phenomenon is eliminated. The formulation is applied to six examples to verify its capabilities. The results demonstrate that the presented element is capable of representing the behaviour of the curved beam with adequate accuracy and efficiency as compared with the previous methods.
Numerical and experimental analysis of the rotor—bearing—seal system
Authors: Shen X Y , Jia J H , Zhao M , Jing J P
Published: August 2008

The rotor—bearing—seal system is simulated by a model consisting of the rotor, the bearing, the foundation, and the labyrinth seal. Governing equations are set up theoretically using the finite-element method. The equivalent model of the bearing—foundation support system is analysed. Forces from the bearing—foundation support and gas-excited forces in the labyrinth seal are imposed in the finite-element equations. Then an experimental rotor—bearing—seal device is designed and many tests are carried out. The Bode, orbit, and waterfall plots are all constructed from the experimental data. An experimental rotor system is studied using the developed equations. Theoretical results from the developed model are in agreement with the ones from the experiment. Analysis proves that although the gas-excited force in the labyrinth seal can improve the stable region of the rotor—bearing—seal system, it makes the rotor vibrate more violently and initiates destructive impacts within the rotor system when the rotor running speed reaches a certain level. Oil whirl and oil whip of journal bearings are found in both the theoretical calculation and the experiment.
A sound field visualization system based on the wave superposition algorithm
Authors: Li J Q , Chen J , Yang C , Dong G M
Published: August 2008

Sound field visualization is a helpful design and analysis tool for the study of sound radiation and dispersion problems. It can help to comprehend deeply about noise transmission mechanism, monitor environment noise, evaluate sound quality, and even diagnose the machinery faults based on mechanical noise. The well-known near-field acoustic holography is an accurate sound field visualization technique. However, this technique has disadvantages such as strict measurement requirements and the need of an enormous number of microphones, which limits its extended applications. In order to visualize the sound field with a small number of microphones for measurements, the regeneration method of the radiated field by using the wave superposition algorithm is attempted in this study. It is based on the principle of equivalent source: the sound field radiated by an arbitrarily shaped radiator is substituted by the distributed point sources (monopole or dipole) constrained inside the actual source surface. For suppressing the adverse effect of measurement noise, the Tikhonov regularization strategy is adopted to work together with the wave superposition algorithm to give an accurate solution. Numerical simulations were performed based on a two-pulse-ball model to evaluate the accuracy of the combined algorithm of the wave superposition and the Tikhonov regularization strategy. In addition, an integrated sound field visualization system is designed and implemented. The functions include acoustic signal acquisition and processing, sound field reconstruction, and results visualization. The performance of the presented system was tested by experiments in a semi-anechoic chamber by using two sound boxes to simulate the sound sources. As concerning practical measurement microphones, there exist phase mismatches between the channels. Results will go wrong if the sound field reconstruction is performed directly with these uncalibrated measurement data. Therefore, a calibration procedure is applied to eliminate them. Experimental results indicate that the phase mismatches between the channels after calibration decay to 0.1°. Both the numerical simulations and experimental results accurately reconstructed the exterior sound field of the models. It is shown that the wave superposition algorithm together with the Tikhonov regularization strategy can exactly reconstruct the exterior sound field of radiators, which makes a base to its applications in practice. This sound field visualization system will make an operator's experimental work much easier.
Numerical simulation for optimal configuration of heater and cooler locations with natural convection inside a square enclosure and the effect of radiation in the presence of radiatively active medium
Authors: Mahapatra S K
Published: August 2008

This study numerically simulates the transport phenomena in steady, two-dimensional, and laminar flow accompanied by heat transfer in a partially heated and partially cooled cavity in the presence of radiatively absorbing, emitting, and scattering gray medium. A portion of the left and right vertical walls is considered as the heater and cooler with constant temperature, respectively, whereas the rest of respective vertical wall is considered to be adiabatic. The horizontal walls are considered adiabatic, too. The discrete ordinate method has been used in modelling the radiative transfer equation followed with finite-volume method as discretization technique. The walls are considered opaque, diffusive, and gray. The effect of radiation, locations of both heater and cooler on fluid flow, and heat transfer has been studied.
Inter-facial shear effects of ultra-thin film on laminated glass plate dynamical behaviour
Authors: Akrout A , Hammami L , Tahar M B , Haddar M
Published: August 2008

This paper deals with a numerical investigation for the analysis of a laminated glass plate composed of two elastic skins joined with an adhesive ultra-thin film. Hence, a new dynamic model of laminated glass is developed using the Kirchhoff plate theory and taking into account the shear stress at the two skin's interface. The formulation is based on the theory that introduces a specific behaviour law for an ultra-thin film that expresses the discontinuity of displacements at the interface. Besides, the dynamic model is established in an appropriate dimensionless form including the effects of ultra-thin film stiffness and without taking into account the film thickness. The finite-element (FE) method is used for the discretization of the energy functional, which gives a linear matrix system after minimization. A modal approach is adopted to investigate the laminated glass vibratory behaviour. The eigenmodes of the laminated plate are determined. Dynamic response is then obtained by modal recombination. The validation of the new laminate FE model is achieved by comparing the laminated plate results with data obtained from the literature. Numerical results show the reduced vibration's amplitude of a laminated glass plate with ultra-thin film when compared with the one that did not take into account the shear inter-facial stress for the two cases of isotropic and orthotropic materials. Also, the influence of the ultra-thin film stiffness on the dynamical behaviour of the structure is presented and analysed.