bluuebunny/crossref_metadata_2025 huggingface dataset:
Maximum power control for photovoltaic system using intelligent strategies
Authors: Slimi Mohammed , Boucheta Abdelkrim , Bouchiba Bousmaha
Published: January 2019

The power supplied by photovoltaic DC–DC converter is affected by two factors, sun irradiance and temperature. Therefore, to improve the performance of the PV system; a mechanism to track the maximum power point (MPP) is required. Conventional maximum power point tracking approaches, such as observation and perturbation technique present some difficulties in identifying the true MPP. Therefore, intelligent systems including fuzzy logic controllers (FLC) are introduced for the maximum power point tracking system (MPPT). In this paper, we present a comparative study of the PV standalone system which is controlled by three techniques. The first one is conventional based on the observation and perturbation technique, the other are intelligent based on fuzzy logic according Mamdani and Takagi-Sugeno models. The investigations show that the fuzzy logic controllers provide the best results and Takagi-Sugeno model presents the lower overshoot value.
Performance analysis of hybrid photovoltaic/wind energy system using KY boost converter
Authors: Pushpavalli Murugan , Jothi Swaroopan N.M
Published: January 2019

Nowadays tremendous increase in renewable energy technologies available in abounding nature energy extracted from sun, wind etc.  This Proposed topology gathered maximum power using multi input ky boost converters for hybrid energy. This hybrid topology operates mainly delivered the power from renewable energy sources solar/wind to dc bus. In the absence of any one source, wind or solar supplies power to the dc bus. Without any renewable energy sources battery deliver the power to dc bus.An inverter type module convert the power from dc bus to ac grid. In this paper effectiveness of hybrid renewable energy is simulated through MATLAB/SIMULINK
A New Small-Signal AC Model and Closed Loop Control of a Three-Phase Interleaved Boost Converter
Authors: Rao H.V.Gururaja , Mudliyar Karuna , Mala R.C.
Published: January 2019

Renewable energy sources are increasingly being used today and solar energy is the most readily and abundantly available energy source. Boost converters are an integral part of any solar energy system. In order to obtain maximum possible energy from the solar system multi-phase interleaved boost converters are used. This paper presents the small-signal ac modelling and closed loop control of three-phase interleaved boost converter. State–space modelling methodology has been adopted to have linearized equivalent model of the boost converter. The interleaved three-phase boost converter is averaged over its one switching period and perturbed with small ac variations and finally linearized around its quiescent point to have a small signal ac model.  Type III compensator is employed to improve the frequency response and closed loop control of three-phase boost converter. The controller design procedure is discussed in detail. The effect of right-half plane zero in non-minimum phase system and the appropriate pole-zero placements to overcome the maximum phase lag in such system is discussed. The compensated closed loop system is tested for load variations to observe the transient response.

 
Half Cycle Discrete Transformation for Voltage Sag Improvement in an Islanded Microgrid using Dynamic Voltage Restorer
Authors: Srivatchan N.S. , Rangarajan P.
Published: January 2019

Growing demand for clean and green power has increased penetration of renewable energy sources into microgrid. Based on the demand supply, microgrid can be operated in grid connected mode and islanded mode. Intermittent nature of renewable energy sources such as solar and wind has lead to number of control challenges in both modes of operation. Especially islanded microgrid throws power quality issues such as sag, swell, harmonics and flicker. Since medical equipments, semiconductor factory automations are very sensitive to voltage variations and therefore voltage sag in an islanded microgrid is of key significance. This paper proposes a half cycle discrete transformation (HCDT) technique for fast detection of voltage sag in an islanded microgrid and thereby provides fast control action using dynamic voltage restorer (DVR) to safe guard the voltage sensitive equipments in an islanded microgrid.  The detailed analysis of simulation results has clearly demonstrated the effectiveness of proposed method detects the voltage sag in 0.04 sec and there by improves the voltage profile of islanded microgrid.
Review of the most applicable regulator collections to control the Parallel Active Power Filter
Authors: Gasmi Belkacem , Abdelkhalak Othmane
Published: January 2019

This work presents a study of the three-phase parallel active power filter and the various controllers used in its control. Moreover, in order to improve the quality of electrical energy, by making it conform to the new normative constraints, we have also been led to develop and apply advanced automation methods. In this framework, this paper reports of several regulatory structures : fuzzy logic, PWM, new space vector PWM (NSVPWM), space vector PWM (SVPWM), HYSTERESIS moreover, in order to produce a parallel active filter, a thorough study of experimental feasibility was carried out, taking into account the industrial constraints of the product both in its design and its application.
Primary Study of Tracking Photovoltaic System for Mobile Station in Malaysia
Authors: Fudholi Ahmad , Haw Lim Chin , Sopian Kamaruzzaman , Omer Abdulmula Ahmed Mohamed
Published: January 2019

This paper describes the performance of tracking photovoltaic (PV) system for mobile station. The system consists of tracking PV array, the battery bank, the maximum power point tracking (MPPT) controller and the DC/AC inverter). This system is the first full solar power station, which acts as pilot project by Celcom Sdn. Bhd. Success of this system shows potential of electrify rural remote area. The design is hoped to be a pioneer and acts as well-known system in order to ensure renewable energy is the future supply of electricity in far located urban area. This paper showes the record of the battery state-of-charge (SOC) as a function of time for rainy and sunny days.
Aspergillus fuscicans (Aspergillaceae, Eurotiales), a new species in section Usti from Argentinean semi-arid soil
Authors: ROMERO STELLA M. , COMERIO RICARDO M. , BARRERA VIVIANA A. , ROMERO ANDREA I.
Published: January 2019

Aspergillus fuscicans, a new species within Aspergillus section Usti from Argentinean semi-arid soil is introduced. Molecular, morphological and physiological studies were conducted, based on sequence analysis of partial β-tubulin and calmodulin sequence data. Aspergillus fuscicans formed a distinct, well-defined clade related to A. calidoustus and A. pseudodeflectus. In addition, A. fuscicans was able to grow and sporulate at 37 ºC, and had a negative Ehrlich reaction. Morphological and physiological features could be used to differentiate the new species from its phylogenetically related taxa.
A new species of the Amphisbaena (Squamata, Amphisbaenidae) from the Brazilian Cerrado with a key for the two-pored species
Authors: RIBEIRO SÍRIA , SÁ VÂNIA , SANTOS-JR ALFREDO P. , GRABOSKI ROBERTA , ZAHER HUSSAM , GUEDES ANDREI G. , ANDRADE SHEILA P. , VAZ-SILVA WILIAN
Published: January 2019

Here, we describe a new species of Amphisbaena with two precloacal pores from open Cerrado areas of the municipality of Arenópolis, in the Brazilian state of Goiás. The new species differs from other South American amphisbaenids by the folllowing combination of characters: (1) snout rounded in dorsal view and slightly convex in lateral view; (2) two precloacal pores; (3) 161–176 dorsal half-annuli; and (4) 12–15 tail annuli. Our molecular phylogenetic analysis retrieved a monophyletic Amphisbaena silvestrii group, with A. silvestrii positioned as the sister-group of a clade formed by Amphisbaena anaemariae and the new species described herein. Members of the A. silvestrii group including A. neglecta and A. crisae not added in our phylogenetic analysis are characterized by a relatively small body, two precloacal pores, body coloration with dark and light areas, and lack of specializations on the cephalic or caudal shields. We present a key for two-pored species of Amphisbaena.
Japanese Cedar Pollen–Specific IgA in Nasal Secretions and Nasal Allergy Symptoms
Authors: Suzuki Motohiko , Yokota Makoto , Ozaki Shinya , Matsumoto Tamami , Nakamura Yoshihisa
Published: January 2019

Objective:

IgA-dependent degranulation of eosinophils and positive correlation between IgA and eosinophil cytotoxic protein levels in nasal secretions have been reported. However, the association between IgA and allergic reactions remains unclear. Therefore, we evaluated the changes in Japanese cedar–specific IgA levels and allergy symptoms after Japanese cedar pollen scattering in symptomatic and asymptomatic individuals sensitized to Japanese cedar pollen.

Methods:

Nasal secretion and serum samples were collected from 31 participants (21 symptomatic and 10 asymptomatic participants) in January (preseason) and March (peak season). Japanese cedar–specific IgA or IgE levels were measured using ELISA with diamond-like carbon-coated chips.

Results:

The ratio of Japanese cedar pollen–specific IgA to total IgA (rIgA) in the nasal secretions of symptomatic participants increased significantly in March compared with that in January ( P < .01); however, the ratio of specific IgE to total IgE (rIgE) in nasal secretions did not. rIgA in nasal secretions among asymptomatic participants also did not increase during pollen season. rIgA in nasal secretions was significantly correlated with nasal allergic symptoms (r = 0.82; P < .0001) with no significant correlation between rIgE and symptoms.

Conclusions:

To our knowledge, this is the first study to show an association between nasal symptoms and rIgA in nasal secretions, suggesting that rIgA is useful as an antigen-specific biomarker for allergic rhinitis or pollinosis. Furthermore, rIgA values in nasal secretions do not increase in asymptomatic participants sensitized to Japanese cedar during the pollen season.
Laryngeal Cryptococcosis: An Evolving Rare Clinical Entity
Authors: Worrall Douglas M. , Lerner David K. , Naunheim Matthew R. , Woo Peak
Published: January 2019

Objectives:

Describe the demographics and clinical manifestations of laryngeal cryptococcosis. Develop a simple approach to the diagnostic workup and treatment of localized laryngeal cryptococcal infection.

Methods:

A new case of laryngeal cryptococcosis encountered at our institution is presented and placed in context of the literature surrounding prior reported cases. PubMed, Google Scholar, SCOPUS, and Web of Science were queried from inception to August 2018 with the terms Larynx or Laryngeal and Cryptococcosis or Cryptococcus by two independent reviewers for English-language cases of cryptococcal infection of the larynx.

Results:

Twenty-nine unique cases of laryngeal cryptococcosis were identified. Median age at presentation was 65 years old. All patients presented with persistent or progressive hoarseness. Lesions were predominantly on the true vocal cords (79%), 38% associated with an adherent white exudate or leukoplakia. A minority (28%) was immunocompromised, and of the remaining immunocompetent hosts, 67% were found to be using nebulized or inhaled corticosteroids (ICS) prior to infection. Diagnosis should be suspected in patients with chronic laryngitis or mass lesions with the aforementioned risk factors. Diagnosis was made by histopathology with cryptococcal yeasts identified on methenamine silver (55%) and/or mucicarmine stains (48%). Serum cryptococcal antigen testing was unreliable (sensitivity = 39%). The mainstay of effective treatment was prolonged oral Fluconazole therapy, with two cases of laser therapy ablation of residual lesions. Improvement in voice and vocal lesions varied from weeks to months.

Conclusions:

Laryngeal cryptococcosis is a rare cause of persistent hoarseness, which appears to be clinically evolving and more frequently affecting immunocompetent hosts chronically using nebulized or inhaled corticosteroids. Laryngeal cryptococcal infection is readily treatable with prolonged oral antifungals once biopsy and histopathological stains confirm the diagnosis.
Career Development of Sexual and Gender Minority Persons Living With Disabilities
Authors: Dispenza Franco , Brennaman Courtney , Harper Lauren S. , Harrigan Megan A. , Chastain Taylor E. , Procter Jonathan E.
Published: January 2019

Sexual and gender minority persons, as well as persons living with disabilities, encounter significant career development issues. However, the career development trajectories for sexual and gender minority persons living with disabilities have not been fully explored. The goal of our qualitative study was to explore factors that influence the career development trajectories of sexual and gender minority persons living with disabilities. Using constructivist grounded theory methods, we conducted semistructured interviews with 21 diverse individuals living in the United States. The core category, Intersectional Adaptation, described how study participants navigated their career development trajectory. The four remaining categories included Psychosocial Capital, Psychosocial Conflicts, Intersectional Identity Disclosure, and Work–Life Balance. We discuss the limitations of the study as well as the implications for future research and provide suggestions for career counseling.
Static and dynamic mechanical properties of graphene oxide-based bone cementing agents
Authors: Khan Aftab Ahmed , Mirza Eraj Humayun , Mohamed Badreldin Abdelrhaman , El-Sharawy Mohamad Ahmed , Hasil Al-Asmari Mohammed , Abdullah Al-Khureif Abdulaziz , Ahmad Dar Mushtaq , Vallittu Pekka K
Published: January 2019

The purpose of this laboratory study was to formulate graphene oxide (GO) nano-sheets and characterize composites of homogenously dispersed GO sheets in poly(methyl methacrylate) (PMMA) acrylic resin of two groups, i.e., with 0.025 wt/wt.% GO (GO1-group) and 0.05 wt/wt.% GO (GO2-group). A large array of surface, mechanical and dynamic mechanical properties, including creep, recovery, stress relaxation behaviour and temperature and frequency sweep of the formulated bone cements were further characterized. Analysis of variance test results (p = 0.05, n = 5) indicated that the nanohardness and elastic modulus of the experimental groups were not significantly different from those of the control. Micro-computed tomography results showed high porosity in the experimental groups. The compressive strength significantly increased both in GO1- and GO2-group under dry and wet storage conditions. The dynamic mechanical properties suggest a desirable role of GO in polymerization with PMMA. The produced GO-PMMA composites exhibited the expected characteristics, so their use in developing low-loading bone cement composites appears to be promising.
NewGene: An Introduction for Users
Authors: Bennett D. Scott , Poast Paul , Stam Allan C.
Published: January 2019

This article introduces NewGene, a complete redesign of the popular EUGene software. Like its predecessor, NewGene is designed to eliminate many of the difficulties commonly involved in constructing large international relations data sets. NewGene is a stand-alone Microsoft Windows and OSx-based program for the construction of annual, monthly, and daily data sets for a variety of decision-making units (e.g., countries, leaders, organizations) used in quantitative studies of international relations. It also provides users the ability to construct units of analysis ranging from monads (e.g., country-year), to dyads (e.g., country1-country2-year), to extra-dyadic observations called k-ads (e.g., country1-country2-year,…, -country k-year). NewGene’s purpose is to provide a highly flexible platform on which users can construct data sets for international relations research using preloaded data or by incorporating their own data. The software is freely available at http://www.newgenesoftware.org/ .
An adaptive semismooth Newton method for approximately solving control-constrained elliptic optimal control problems
Authors: Solaymani Fard Omid , Borzabadi Akbar Hashemi , Sarani Farhad
Published: January 2019

The main goal of this paper is to study, analyse and prove the global convergence property of a nonmonotone semismooth Newton method. Based on this property, we aim to exploit an adaptive nonmonotone line search method and apply it for the approximate solution of elliptic optimal control problems with control constraints. To this end, we first convert the optimal control problem to a bound constrained optimization problem by using a finite-difference discretization scheme and a Newton–Cotes rule. Then we implement the adaptive nonmonotone semismooth Newton method to the resulting bound constrained optimization problem. We give some numerical examples to demonstrate the validity, efficiency and applicability of the presented method.
‘Free to Do What I Want’? Exploring the ambivalent effects of liberating leadership
Authors: Picard Hélène , Islam Gazi
Published: January 2019

This study examines the phenomenon of ‘liberating leadership’, an emerging trend promising self-mastery and collective unity, resonating with the literature on post-heroic leadership. We evaluate the claims of liberating leadership from a psychodynamic perspective, using a Lacanian approach. We examine how post-heroic forms of leadership reconfigure symbolic and imaginary aspects of follower identification, with ambivalent effects. Drawing empirically on the case of a Belgian banking department, we trace how a ‘liberating’ leader was able to garner intense psychological attachment among followers, accompanied by the ‘dark sides’ of personal exhaustion and breakdown, normative pressure to be overly happy, and the scapegoating of contrarian managers representing symbolic prohibition.
Leading a Successful Transition to Democracy: A Qualitative Analysis of Political Leadership in Spain and Lithuania
Authors: Kalpokaite Neringa , Radivojevic Ivana
Published: January 2019

Any country embarking upon a political transition to democracy faces a complex period of change. While many factors influence successful democratization, political leadership remains a relatively unexplored phenomenon. This research presents a theoretical framework that is corroborated with data gathered from 65 semi-structured interviews with people involved in the transition processes of Spain and Lithuania along with the main political leaders themselves: King Juan Carlos I, Adolfo Suárez, Algirdas Brazauskas and Vytautas Landsbergis. The four leaders presented a similar political leadership style – based on their vision, decision-making, negotiation and power – which positively influenced the success of each transition to democracy.
Bullshit and Organization Studies
Authors: Christensen Lars Thøger , Kärreman Dan , Rasche Andreas
Published: January 2019

Bullshit is a ubiquitous communication practice that permeates many dimensions of organizational life. This essay outlines different understandings of bullshit and discusses their significance in the context of organization studies. While it is tempting to reject bullshit as corrosive to rational organizational practice, we argue that it is necessary to understand its organizational significance and performative nature more systematically. We outline different social functions of bullshit focusing on two particular types of managerial practices in which bullshit is likely to play a significant role: commanding and strategizing. On this backdrop, we consider bullshit in terms of the messages, senders and receivers involved, focusing especially on the dynamics between these dimensions in the context of organizations. The final part of this essay debates the reasons why bullshit, which is recognized by organizational members, is rarely called and rejected explicitly.
Communicating with Voters on YouTube: Content Analysis of the Relationship Between Advertisement Message Characteristics and Viewers’ Responses
Authors: Sohal Seerat , Kaur Harsandaldeep
Published: January 2019

The present study is an endeavour to broaden the research on the use of social media websites in political campaigns beyond the ambit of developed countries. This article focuses on scrutinizing the role of YouTube during 2014 Indian Parliamentary elections—the first ‘social media’-based elections in India. The methodology of data collection incorporates the content analysis of 147 YouTube-based audio–visual political advertisements, associating the message characteristics (natures, types and appeals) with message reach (number of views) and viewer engagement (types of comments). The results reveal the failure of the viewers to recognize the association between message reach and viewers’ engagement with message characteristics, confirming the ‘marginal’ use of YouTube. However, the study recommends the incorporation of contemporary, Internet-based social media advertising tools along with the traditional tools in the future political marketing campaigns. This article is instrumental for political marketers and consultants in devising political marketing strategies.
Development and Validation of the Evaluation Platform in COPD (EPIC): A Population-Based Outcomes Model of COPD for Canada
Authors: Sadatsafavi Mohsen , Ghanbarian Shahzad , Adibi Amin , Johnson Kate , FitzGerald J. Mark , Flanagan William , Bryan Stirling , Sin Don ,   for the Canadian Respiratory Research Network
Published: January 2019

Background. We report the development, validation, and implementation of an open-source population-based outcomes model of chronic obstructive pulmonary disease (COPD) for Canada. Methods. Evaluation Platform in COPD (EPIC) is a discrete-event simulation model of Canadians 40 years of age or older. Three core features of EPIC are its open-population design (incorporating projections of future population growth, aging, and smoking trends), its incorporation of heterogeneity in lung function decline and burden of exacerbations, and its modeling of the natural history of COPD from inception. Multiple original data analyses, as well as values reported in the literature, were used to populate the model. Extensive face validity and internal and external validity evaluations were performed. Results. The model was internally validated on demographic projections, mortality rates, lung function trajectories, COPD exacerbations, costs and health state utility values, and stability of COPD prevalence over time within strata of risk factors. In external validation, it moderately overestimated the rate of overall exacerbations in 2 independent trials but generated consistent estimates of rate of severe exacerbations and mortality. Limitations. In its current version, EPIC does not consider uncertainty in the evidence. Several components such as additional (e.g., environmental and occupational) risk factors, treatment, symptoms, and comorbidity will have to be added in future iterations. Predictive validity of EPIC needs to be examined prospectively against future empirical studies. Conclusions. EPIC is the first multipurpose, open-source, outcome- and policy-focused model of COPD for Canada. Platforms of this type have the capacity to be iteratively updated to incorporate the latest evidence and to project the outcomes of many different scenarios within a consistent framework.
Contrast-enhanced spectral mammography in the evaluation of breast suspicious calcifications: diagnostic accuracy and impact on surgical management
Authors: Houben Ivo PL , Vanwetswinkel S , Kalia V , Thywissen T , Nelemans PJ , Heuts EM , Smidt ML , Meyer-Baese A , Wildberger JE , Lobbes MBI
Published: January 2019

Background

Detecting pathological breast calcifications remains challenging. Based on recent studies, contrast-enhanced spectral mammography (CESM) was shown to be superior compared to full-field digital mammography (FFDM).

Purpose

To evaluate the diagnostic accuracy of CESM in suspicious breast calcifications and its impact on surgical decision-making.

Material and Methods

All screening recalled patients with suspicious calcifications that underwent CESM in the period October 2012 until September 2015 were included. One experienced radiologist provided a BI-RADS classification for the FFDM images only. The evaluation was repeated for the CESM exam. In a simulated tumor board meeting, two breast surgeons decided on the preferred surgical treatment (breast conservation therapy [BCT] versus mastectomy) for all malignant cases. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated defining BI-RADS ≥4 as being malignant. In addition, differences in surgical decision-making were analyzed and compared using McNemar’s test.

Results

In total, 147 women were included in this study (mean age = 61 years; age range = 49–75 years). Pathology showed 82 benign and 65 malignant lesions, of which 33 were ductal carcinomas in situ and 32 were invasive lesions. Diagnostic performances of CESM (differences compared to FFDM in brackets) were: sensitivity 93.8% (+3%), specificity 36.6% (−2.5%), PPV 54% (0%), and NPV 88.2% (+4%). Based on low-energy images, surgeons suggested BCT in 89% of the cases. Based on the CESM exam, no statistical changes in decisions were observed (86% BCT, P = 0.453).

Conclusion

CESM only slightly improves the diagnostic accuracy of the evaluation of breast calcifications. It is not of added value compared to FFDM in guiding surgical decision-making.
Differentiation between solid pseudopapillary neoplasm of the pancreas and hypovascular pancreatic neuroendocrine tumors by using computed tomography
Authors: Wang Cheng , Cui Wenjing , Wang Jianhua , Chen Xiao , Tong He , Wang Zhongqiu
Published: January 2019

Background

Solid pseudopapillary neoplasm of the pancreas (SPNs) usually showed slight enhancement in contrast-enhanced computed tomography (CE-CT), which is similar to hypovascular pancreatic neuroendocrine tumors (hypo-PNETs).

Purpose

To show the values of CT imaging features in the differentiation between hypo-PNETs and SPNs.

Material and Methods

Forty-four patients with histologically confirmed SPNs and 24 patients with hypo-PNETs who underwent preoperative dynamic CE-CT were included. Two radiologists reviewed CT imaging findings and clinical features. Multivariate logistic regression analysis was performed to identify relevant features to differentiate SPNs and hypo-PNETs. Receiver operating characteristic (ROC) curve was used to evaluate the diagnostic performance.

Results

SPNs usually occurred in young women compared with hypo-PNETs (mean age = 34.5 years vs. 49.08 years, P < 0.01). SPNs usually showed an oval shape, “floating cloud” sign, calcification, and lower frequencies of metastases compared with hypo-PNETs ( P < 0.05 for all). The combined features (lower age, “floating cloud” sign, and calcification) showed acceptable diagnostic performance (area under the curve [AUC] = 0.865 with 100% sensitivity and 63.6% specificity) for differentiating SPNs from hypo-PNETs.

Conclusion

“Floating cloud” sign, lower age, and calcification have great potential in differentiating SPNs from hypo-PNETs.
Including selective metabolic components in current diagnostic criteria does not improve discriminative validity for metabolic syndrome: a risk score approach
Authors: Chang Huan-Cheng , Chen Sheng-Pyng , Yang Hao-Jan
Published: January 2019

Objective

To examine whether including additional metabolic components to the current five-marker system can improve the discriminative validity for diagnosing metabolic syndrome (MetS).

Methods

This longitudinal cohort study included data from subjects that had completed at least three health examinations during a 5-year period. The study outcome was the onset of MetS. Sociodemographic and biochemical variables were recorded for all subjects so that the adjusted relative risks (ARRs) could be calculated for 11 metabolic components. Risk scores for the development of MetS based on the ARR values were determined. The sums of the risk scores of different component combinations were used to conduct a receiver operating characteristic (ROC) curve analysis of MetS diagnosis.

Results

A total of 3368 individuals with complete data was analysed. The ARRs of the 11 metabolic components were all statistically significant. According to ROC analysis, although good discriminative validity (area under the curve [AUC] range, 0.954–0.976) could be achieved for MetS diagnosis by using either all 11 or combinations of six metabolic components (the five current components plus one extra component), the current five metabolic components used for diagnosis had the best discriminative validity (AUC = 0.977).

Conclusion

The current five metabolic components used for the diagnosis of MetS still represent the best combination with the highest discriminative validity.
Double-Blind Trial Comparing Epidural Lignocaine with Epidural Fentanyl for Anaesthesia during Extracorporeal Shock Wave Lithotripsy
Authors: Silbert B. S. , Kluger R. , Meads A. C. , Stasytis K.
Published: January 2019

A randomised double-blind trial was undertaken to compare epidural lignocaine 1.5% with adrenaline to epidural fentanyl (100μg in saline 10 ml) in forty unpremedicated patients undergoing extracorporeal shock wave lithotripsy without ancillary procedures. Midazolam only was used for sedation. There was no significant difference in intraoperative pain scores with several patients in each group complaining of pain. Decreases in blood pressure occurred in both groups but were more pronounced in the lignocaine groups (36% vs 25 % maximum decrease from control, P = 0.004). Heart rate was increased in the lignocaine group compared with control and to the fentanyl group, but there was no difference in respiratory rates within or between groups. Pruritis was more common in the fentanyl group and leg heaviness in the lignocaine group, but neither was troublesome. There was no difference in urological outcome at one month. Both techniques were satisfactory for the majority of patients, but the fentanyl group had a shorter preparation time and less cardiovascular changes.
Physiological Changes during Liver Transplantation
Authors: Kalpokas M. , Bookallil M. , Sheil A. G. R. , Rickard K. A.
Published: January 2019

Thirteen patients who received liver transplants at the National Liver Transplant Unit between January 1986 and March 1987 were studied with extensive monitoring and frequent intraoperative biochemical and haematological profiles. Anaesthetic technique was standardised for all patients.

Retrospective analysis of this data confirms that patient homeostasis is most disturbed at the time of revascularisation of the donor liver. In this series, revascularisation was associated with marked changes in all measured haemodynamic parameters (arterial blood pressure, cardiac index, heart rate, and filling pressures). There was also a significant fall in pH with revascularisation, followed by a gradual rise during the final phases of the operation. Potassium levels often rose sharply with revascularisation but then decreased during the rest of the operative period. Ionised calcium levels did not change significantly at any stage; however, all patients were given calcium intraoperatively. Coagulation profiles were often abnormal preoperatively. The transplant procedure was associated with further abnormalities in both coagulation and fibrinolysis. Patient temperatures were maintained at normal levels throughout the procedure.
Endotoxins and Anti-endotoxins (Their Relevance to the Anaesthetist and the Intensive Care Specialist)
Authors: Brock-Utne J. G. , Gaffin S. L.
Published: January 2019

Endotoxins (lipopolysaccharides, LPS) are potent bacterial poisons always present within the intestines in considerable amounts. Several pathophysiological conditions such as hypovolaemia, hypoxia, intestinal ischaemia, burns and radiation lead to a breakdown in the barrier and depending upon the extent of the injury, endotoxins enter the systemic circulation in increasing amounts. Antibiotics do not inactivate the endotoxins which continue to exert their toxic effects leading to nausea, vomiting, diarrhoea, fever, disseminated intravascular coagulation, vascular collapse and organ failure.

When nonabsorbable antibiotics are given prior to the insult, systemic endotoxaemia is prevented. Immunotherapy, using anti-lipopolysaccharide IgG, inactivates plasma endotoxins, destroys gram-negative bacteria and opsonises them and may become a major form of therapy. An outline of endotoxin and anti-lipopolysaccharide and its importance to the anaesthetist and intensive care specialist is presented.
An Electrode Montage for Electrocardiographic Monitoring
Authors: Wicks M. , Hunt J. , Walker R. , Torda T. A.
Published: January 2019

An electrocardiographic electrode montage is described using electrodes mounted on the manubrium sterni (RA), xiphisternum (LA) and V5 position (LL). The lead II setting on the monitor, equivalent to CM5, offers optimal ischaemia detection, while lead I, now a vertical lead, manubrium to xiphisternum, results in maximal P wave amplitude. The montage has been evaluated in sixty-two intensive care patients with electrocardiographic abnormalities and has been used extensively in intensive care, the operating theatres and in shock wave lithotripsy. The ‘Prince Henry’ montage offers advantages over the standard bipolar leads in P wave amplitude, arrhythmia diagnosis and artefact rejection.
A Rural Retrieval Service
Authors: Burrell A. R. , Haynes S. B. , Wilson R. D.
Published: January 2019

In rural areas critically ill patients are transferred frequently from smaller to larger hospitals. The time spent in transit may influence their outcome. Intensive care facilities in the Central Western Health Region of N.S.W. are located at The Orange Base Hospital and many of the patients admitted to that unit each year are transferred from other hospitals. Since 1984 The Orange Base Hospital, with the N.S. W. Ambulance Service, has offered a retrieval service, and during the three years 1984–86, 135 patients have been retrieved. The service has been well accepted, the only major criticism from the referring hospitals being the extra time taken for some patients suffering from trauma to receive definitive treatment. By improving communications and developing a regional plan, this difficulty may to some extent be overcome.
Residual Psychomotor Effects following Reversal of Midazolam Sedation with Flumazenil
Authors: Short T. G. , Galletly D. C.
Published: January 2019

The ability of flumazenil to reverse the effects of midazolam sedation was examined in a randomised, crossover, placebo controlled study in six male volunteers. Subjects received intravenous injections of either (a) midazolam 10 mg followed 10 minutes later by flumazenil 1.0 mg or (b) midazolam 10 mg followed after 10 minutes by flumazenil 4 mg or (c) placebo followed after 10 minutes by placebo. Post reversal drug effects were examined using a psychomotor battery (critical flicker fusion, digit symbol substitution, tapping test, ball-bearing test, number recall, reflex time) and linear analogue mood scales.

It was found that a residual psychomotor deficit was present following flumazenil and that this persisted for up to 125 minutes after the 1.0 mg dose and 65 minutes following 4 mg. A small deterioration in performance was apparent after initial reversal with 1.0 mg, the peak deterioration occurring at 35 minutes.
Congenital Myotonic Dystrophy in Children — A Review of Ten Years’ Experience
Authors: Anderson B. J. , Brown T. C. K.
Published: January 2019

A review of the anaesthetic management of children with congenital myotonic dystrophy anaesthetised at the Royal Children's Hospital over the past ten years is presented. Seven children underwent a total of fourteen anaesthetics. Anaesthetic considerations must include the degree of muscle weakness and hypotonia altering muscle relaxant requirements, aspiration risk due to palatopharyngeal dysfunction, and cardiomyopathy. Succinylcholine caused muscle contracture in a patient without clinical myotonia. This drug should be avoided. Although a low threshold to institute postoperative respiratory support must exist when treating neonates and infants, the older children did not clinically exhibit increased sensitivity to respiratory depressant drugs.
Evaluating Dynamic Modulus for Indiana Mechanistic-Empirical Pavement Design Guide Practice
Authors: Batioja-Alvarez Dario , Lee Jusang , Nantung Tommy
Published: January 2019

After the implementation of the Mechanistic-Empirical Pavement Design Guide (MEPDG) in Indiana, an overall evaluation of the stiffness characteristics of local AC mixtures and the ability of level III MEPDG predictive equations to estimate dynamic modulus (E*) with local mixtures was required. Therefore, the primary objectives of this study were to identify significant differences among Indiana asphalt mixtures, to evaluate the performance of commonly used E* predictive models, and to assess the influence of level III E* input on the pavement design life of typical pavement structures. It was found that Indiana mixtures do not show extensive variability among mixtures having the same nominal maximum aggregate size. When conducting a statistical analysis to group asphalt mixtures having similar characteristics, few mixtures were left out of the groups. In general, it was observed that mixtures having Ndes equal to 75, showed the lowest E* values along the entire frequency range. The Witczak 1-37A showed the most accurate and less biased E* predictions for Indiana mixtures. It showed the highest R2, and the least deviation from the measured E* values. However, predicted E* input values produced higher levels of pavement distress compared with measured E* values, indicating general overprediction. Besides, using level III (predictive) rather than level I (measured) E* input values can influence the pavement thickness design due to the functional performance (i.e., the International Roughness Index (IRI)). When a structural performance (i.e., bottom-up cracking) was taken into consideration, no influence of the E* input type on the design AC layer thickness was observed.
Design and investigation of pole assignment controller for driving nonlinear electro hydraulic actuator with new active suspension system model
Authors: Al-Zughaibi Ali , Xue Yiqin , Grosvenor Roger , Okon Aniekan
Published: January 2019

Fully active electrohydraulic control of a quarter-car test rig is considered from both a modelling and experimental point of view. This paper develops a nonlinear active hydraulic design for the active suspension system, which improves the inherent trade-off between ride quality and suspension travel. The novelty is in the use of pole assessment controller to drive a nonlinear active suspension with a new insight into the model through consideration of a new term, friction forces. Therefore, this model has taken into account the dynamic inclination angle [Formula: see text] between linkage and actuator regardless of the fact that the designer made an only vertical motion (bounce mode) of the wheel and body units. The second contribution of this paper is that it investigated the control force generation, therefore, the nonlinear hydraulic actuator whose effective bandwidth depends on the magnitude of the suspension travel, which incorporates the dynamic equation of servovalve, is deeply researched. The nonlinear friction model is accurately established, which relies on the dynamics system analysis and the fact of slipping the body on lubricant supported bearings; this model will caption all the friction behaviours that have been observed experimentally. In addition, the hydraulic system is used to generate the system inputs as a road simulator. The controller smoothly shifts its focus between the conflicting objectives of ride comfort and rattle space utilisation, softening the suspension when suspension travel is small and stiffening it as it approaches the travel limits. Thus, the nonlinear design allows the closed-loop system to behave differently in different operating regions. The improvement achieved with our design is illustrated through comparative experiments and simulations. C++ compiler environment is used to simulate the physical system to be controlled. The results show good servo control and fast regulation of abrupt disturbances.
Power losses distribution in serpentine belt drive: Modelling and experiments
Authors: Silva Carlos AF , Manin Lionel , Andrianoely Marie-Ange , Besnier Etienne , Remond Didier
Published: January 2019

Over the last years, significant research effort has been directed towards developing vehicle transmissions more energy efficient. This effort has been a direct consequence of the new environmental regulations encouraging truck and car manufacturers to reduce the power losses of their engines. For development purposes and in belt transmission design, it is worth predicting the power losses before manufacturing. For predicting the power losses in serpentine belt drive, theoretical models have been developed taking into consideration different types of energy loss taking place in a front engine accessory drive. These losses have several origins: from the poly-V belt or the mechanical components of the system (bearings, tensioners). The present paper reviews the state-of-the-art research on power losses modelling in a front engine accessory drive and focuses on internal and external losses of the belt. To construct a predictive power loss model, external losses such as belt–pulley slip and bearings friction are modelled and implemented in addition to our previous modelling of belt-hysteresis losses. Simulation results are compared with experiments on a specific test bench which has been designed to permit measuring the power losses for any kind of belt transmission layout. The experiment results permit highlighting some particular power losses as belt-hysteresis losses, pulley-belt slip losses and bearing losses. The comparisons between simulation and experimental results permit validating the developed models.
Characterisation of Permeability around a 90° Corner
Authors: Laval Nicolas , Sozer E. Murat , Advani Suresh G.
Published: January 2019

One-dimensional mould filling experiments were done in L- and T-shaped moulds with constant flow rate injection, and the pressure history was measured. Transient relationship between the preform permeability along the flow direction and the time derivative of pressure was used to measure the permeability. It was found that the resistance to flow around the bend increased by an order of magnitude within the boundary layer of the 90° bend. A simple resistive model with three different permeabilities could be used to describe the decrease in the permeability around the bend using a corner model and hence one could predict the permeability in the bend region. While considering numerical simulations of complicated geometries with bends, one should account for the variation in the bend section to capture the physics of flow in such structures.
Interfacial Pathways in Wood
Authors: Baillie Caroline , Tual Delphine , Terraillon Jean Christophe
Published: January 2019

Wood structure and properties have been established for many years. The interaction of structure with properties has also been studied, but rarely from a materials science perspective. This paper attempts to focus on a particular aspect of composite structure, that of the interface. In engineered fibre composites the interface is the most important feature as it is the medium by which the stress is transferred from the matrix to the fibres so that they may bear the load. Much research has been focused on solving the optimisation of the interfacial stress transfer, as it is always suggested that the interface needs to be weak for high toughness and strong for high strength of the composite. More recent studies have identified the fact that it may be more advantageous to create an interface, which is not destructive in its energy absorbing capacity. Another area of weakness at the interface is the resistance to water ingress in certain environmental conditions.

Biomimetics is an emerging approach to solving scientific issues by looking to nature to see what solutions are offered for the particular concerns of engineers and their products. In this case wood is the subject of study. It is assumed that wood has optimised its internal interfaces to cope with strength and toughness requirements as well as harsh environmental conditions. The internal interfaces thus need to be firstly examined and identified. This paper looks in a qualitative way at the three different interfacial crack paths which may be likened to those occurring in engineered composites: interfacial, interlaminar and intercellular (bundle/bundle interaction) and their proposed relation to energy absorption mechanisms, It also explores the influence of moisture on these fracture paths.
A 3-D Periodic Instability Model for a Series of Fibres in a Matrix
Authors: Guz A.N. , Lapusta Y.N. , Samborska A.N.
Published: January 2019

An analytical modelling of instability phenomena of a periodic series of fibres in a matrix is presented, describing possible periodic solutions of the problem. The study includes a 3-D generalised problem statement at the fibre-matrix level, developing an analytical technique for obtaining exact solutions of the formulated problem and numerical examples for some particular cases of periodic stability loss modes.
Epoxy Resin Composites with Surface Modified Aramid Fibres
Authors: Rallis G. , Tarantili P. A. , Andreopoulos A. G.
Published: January 2019

Surface modified aramid fibres, after treatment in oxygen plasma and coating with novolac resin, were used for the preparation of reinforced epoxy specimens. The flexural properties of these specimens were determined and the results are discussed taking into consideration the surface characteristics of the modified fibres, as derived from pullout tests and contact angle measurements. Micrographs were also made to provide an additional support to the experimental data of this work. It was shown that both investigated techniques for modifying aramid fibres are adequate to promote their interfacial adhesive bonding to epoxy matrices due to the surface roughness and chemical affinity to the epoxy resin. Coating with novolac seemed a very interesting process since it is a simple and cheap technique and does not affect the fibre integrity.
Loss-Energy to Determine on-Line the State of Damage of Composites under Fatigue Loadings
Authors: Gassan Jochen
Published: January 2019

This paper is dealing with a new method based on determining on-line loss energy as measure of the state of damage of composite materials under tension-tension fatigue loadings. Experimentally, cross-ply glass-fibre epoxy composites with a fibre volume fraction of 0.4 and differences in fibre-matrix adhesion and matrix ductility were tested by a stress-ratio of 0.1 and frequency of 10 Hz. The paper shows, that the online measured loss energy is very sensitive to evaluate the damage state of composite materials. Number of load cycles between a new defined state of damage (damage state ‘A’ in that paper) and final failure for a giver n/N ratio is shown to be sensitive to characterise differences in composite morphology such as level of interfacial strength and matrix ductility. For brittle composites, this damage state ‘A’ can be used to predict fatigue life of composite materials.