bluuebunny/crossref_metadata_2025 huggingface dataset:
Hardware Implementation of Solar based Boost to SEPIC Converter Fed Nine Level Inverter System
Authors: Jasmine D. , Gopinath M.
Published: February 2017

Multi level inverters are widely used in high power applications because of low harmonic distortion. This paper deals with the simulation and implementation of PV based boost to SEPIC converter with multilevel inverter. The output of PV system is stepped up using boost to sepic converter and it is converted into AC using a multilevel inverter. The simulation and experimental results with the R load is presented in this paper. The FFT analysis is done and the THD values are compared. Boost to SEPIC converter is proposed to step up the voltage to the required value. The experimental results are compared with the simulation results. The results indicate that nine level inverter system has better performance than seven level inverter system.
Comparative Performance Study for Closed Loop Operation of an Adjustable Speed Permanent Magnet Synchronous Motor Drive with Different Controllers
Authors: Sain Chiranjit , Banerjee Atanu , Biswas Pabitra Kumar
Published: February 2017

In this paper an extensive comparative study is carried out between PI and PID controlled closed loop model of an adjustable speed Permanent Magnet Synchronous Motor (PMSM) drive. The incorporation of Sinusoidal Pulse Width Modulation (SPWM) strategy establishes near sinusoidal armature phase currents and comparatively less torque ripples without sacrificing torque/weight ratio. In this closed loop model of PMSM drive, the information about reference speed is provided to a speed controller, to ensure that actual drive speed tracks the reference speed with ideally zero steady state speed error. The entire model of PMSM closed loop drive is divided into two loops, inner loop current and outer loop speed. By taking the different combinations of two classical controllers (PI & PID) related with two loop control structure, different approximations are carried out.  Hence a typical comparative study is introduced to familiar with the different performance indices of the system corresponding to time domain and frequency domain specifications. Therefore overall performance of closed loop PMSM drive is tested and effectiveness of controllers will be determined for different combinations.
A Novel Modified Turn-on Angle Control Scheme for Torque-ripple Reduction in Switched Reluctance Motor
Authors: Dowlatshahi Milad , Daryanush Mehrdad
Published: February 2017

In recent years, Switched Reluctance Motors (SRM) have been dramatically considered with both researchers and industries. SRMs not only have a simple and reliable structure, but also have low cost production process. However, discrete torque production of SRM along with intensive magnetic saturation in stator and rotor cores are the major drawbacks of utilizing in variety of industrial applications and also causes the inappropriate torque ripples. In this paper, a modified logical-rule-based Torque Sharing Function (TSF) method is proposed considering turn-on angle control. The optimized turn-on angle for conducting each phase is achieved by estimating the inductance curve in the vicinity of unaligned position and based on an analytical solution for each phase voltage equation. Simulation results on a four-phase switched reluctance motor and comparison with the conventional methods validates the effectiveness of the proposed method.
Hysteresis SVM for Coupled Inductor Z Source Diode Clamped 3-level Inverter based Grid Connected PV System
Authors: Palanisamy R. , Mutawakkil A.U , Vijayakumar K.
Published: February 2017

Due to its advantages such as it can defeat problems such as leakage current and insertion of DC in the grid and provides low stress on power devices, Diode clamped three-level inverter (DCTLI) is habitually used in transformerless photovoltaic (PV) connected to grid network. But it still has a problem of shoot-through which dwells in its legs, so its operation not reliable. Z source network is employed to permit operation without shoot through risk and improve its reliability. Coupled inductors are replace line transformers in to attain lower cost, reduced size, and improved its reliability and efficiency. Coupled inductor which avoids leakage current problem and losses. It employs coupled inductor z source diode clamped three level inverter (CI-Z-DC-TLI) to boost the voltage and further improve the reliability of the system by preventing the shoot through the problem. The proposed system assures that common-mode voltage and shoot-through risk is avoided. Moreover, controlling DC-TLI with Hysteresis SVM algorithm which improves output voltage and current control. Simulation and experimental results of this proposed system were analyzed using MATLAB environment and FPGA hardware.
Electric Power Converter with a Wide Input Voltage Range
Authors: Khokhlov K.O. , Khokhlov G.K. , Ishchenko A.V. , Cherepanov A.N. , Naronov A.S.
Published: February 2017

The electric power converter for downhole telemetry systems of oil-well pumps include a downhole block connected to the pump that contains electronic circuits required for the operation of the motor pump sensors and transmission of data about their condition to the surface are described. A few methods of electric power conversion for this purpose are considered. The circuit contained two steps of voltage converting are proposed. The electrical scheme of this method is considered in the article. Proposed decisions are simulated and verified experimentally. The input high supply voltage range (200-4200 V) without loss of efficiency (even temporary) was obtained. The results of simulation and experimental studies have shown very close results.
A DC Inrush Current Minimisation Method using Modified Z-source Inverter in Adjustable Speed Drives
Authors: Renukadevi S. , Rathinakumar M.
Published: February 2017

The adjustable speed drives employ PWM converter – inverter system in order to obtain unity power factor.The DC inrush current in DC link capacitors of the rectifier limits the operation of power devices.Hence, this paper proposes a new approach to reduce the DC inrush current by employing modified Z-source inverter in a Adjustable Speed Drive system. The operating principles, design procedure and simulation results are shown and compared with the conventional Z-Source inverter.
Design and Implementation of Real Time Charging Optimization for Hybrid Electric Vehicles
Authors: Ramesh K. , Bharatiraja C. , Raghu S. , Vijayalakshmi G. , Sambanthan PL.
Published: February 2017

Electric vehicle (EV) has gained incredible interest from the past two decade as one of the hopeful greenhouse gasses solution. The number of Electric Vehicle (EV) is increasing around the world; hence that making EVs user friendly becomes more important. The main challenge in usage of EV is the charging time required for the batteries used in EV. As a consequence, this subject matter has been researched in many credentials where a wide range of solutions have been proposed. However those solutions are in nature due to the complex hardware structure. To provide an unswerving journey an Android application based charging optimization is proposed. This application is aimed at giving relevant information about the EV’s battery state of charge (SOC), accurate location of the EV, booking of the charging slots using token system and route planner. At emergency situations, an alternative service is provided by mobile charging stations. Route planner indicates the temperature by which prediction of reaching the destination can be done. In addition to that nearest places such as parks, motels are indicated. The estimated time and distance between the electric vehicle and the charging station is calculated by the charging station server according to which the parking lot is allocated. Vehicle to charging station communication is established for the time estimation of charging. This will help the EV users to know about charge status and charging station, which support fast charging method and availability of the station on the go and also when to charge their EV. The Arduino UNO board has been used for the hardware part. The hardware results are confirming the conceptual of the proposed work.
Photovoltaic System with SEPIC Converter Controlled by the Fuzzy Logic
Authors: Oudda Meryem , Hazzab Abdeldjebar
Published: February 2017

In this work, a fuzzy logic controller is used to control the output voltage of a photovoltaic system with a DC-DC converter; type Single Ended Primary Inductor Converter (SEPIC). The system is designed for 210 W solar PV (SCHOTT 210) panel and to feed an average demand of 78 W. This system includes solar panels, SEPIC converter and fuzzy logic controller. The SEPIC converter provides a constant DC bus voltage and its duty cycle controlled by the fuzzy logic controller which is needed to improve PV panel’s utilization efficiency. A fuzzy logic controller (FLC) is also used to generate the PWM signal for the SEPIC converter. 
An Improved Constant Voltage Based MPPT Technique for PMDC Motor
Authors: Asim Mohammed , Tariq Mohd , Mallick M.A. , Ashraf Imtiaz
Published: February 2017

Stand-alone photovoltaic (SAPV) systems are being used in remote areas and are being seen as one of the promising solution in this regard. The SAPV system as presented in the paper consists of solar PV panel, a DC-DC converter, a controller and a PMDC motor. The current-voltage and power-voltage characteristics being nonlinear, the SAPV system require maximum power point techniques (MPPT) control techniques to extract maximum power available from the PV cell. A voltage based MPPT technique which is capable of tracking MPP has been selected because of numerous advantages it offers such as: simple and low cost of implementation. The limitation of constant voltage method is that its efficiency is low as the PV panel has to be disconnected from the load for measurement of the open circuit voltage (Voc). In the presented paper, the authors have removed this limitation by using a pilot PV panel for measurement of Voc. A proportional-integrator (PI) based controller is used in implementation of constant voltage MPP technique and the modeling is done in MATLAB®/SIMULINK simulation environment. The simulation results are presented and discussed in the paper, the results shows that the efficiency of the system has increased.
Vector Control Realization of DFIG Under Grid Abnormalities using Real Time Digital Simulator
Authors: Mohanty Kanungo Barada , Choudhury Satish , Singh Madhu
Published: February 2017

A grid connected doubly-fed induction generator (DFIG) system, driven by variable speed wind turbine is considered in this research to satisfy grid code requirements. Remaining grid synchronized and stable under voltage sag and voltage swell, obtaining power control through dc link voltage control, and providing unity power factor at grid terminals are the achievements. The DFIG system uses two back-to-back converters. Vector control strategy is used with the grid side and rotor side converters, and taken up for research for further improvement. The grid side converter controls dc-link voltage and maintains unity power factor at the grid connection point. The rotor side converter supplies the reactive power of the machine and maintains the speed constant irrespective of the transient behavior of the grid. In this paper the behavior of the DFIG system is analyzed under grid voltage fluctuation and the experimental results are obtained using RT-LAB. Main contribution of this work is in improving the DFIG system performance with grid low voltage and over voltage ride through capability through simulation, and its real time experimental verification.
Comparative Study of Various Adjustable Speed Drives During Voltage Sag
Authors: S Renukadevi , M Rathinakumar
Published: February 2017

This Paper compares the sensitivity of various adjustable speed drives to voltage sag for the process control applications. Three phase voltage sag of type B caused due to SLG fault is considered and four topologies of ASD’s are compared in this paper. The comparison is done especially in speed, voltage, current and torque of the ASDs. Diode rectifier without z source inverter, diode rectifier with z source inverter , single phase two leg Vienna rectifier and single phase neutral linked Vienna with z source inverter are compared and the best one is highlighted. The circuits of various ASD’s are simulated using   Matlab /Simulink. 
Analysis of Harmonics and Ripple Current in Multi-module Converters with Increasing Number of Modules for High Power Applications
Authors: Venkatasubramanian D. , Natarajan S. P.
Published: February 2017

Controlled rectifiers are considered as the most important hardware part in the field of HVDC systems in transmission lines and can be used for a number of power electronics based system operation, control and utility applications. In this paper, a brief design of a 12-pulse, 24-pulse, 36-pulse and a 48-pulse converter connected to the grid is presented along with the harmonic and ripple current analysis with its comparison statistics and thus providing a justification for the suitable ones. The performance of the 12, 24, 36 and 48-pulse converters are compared for their effectiveness in both quantitatively as well as qualitatively. Further, comparison of the 48-pulse converter on its THD and current ripple which is connected towards the grid with simple pulse width modulation technique is also proposed. It combines all features of the low switching concepts and DC current re-injection techniques. Some basic topological explanation of the controlled rectifiers and simulation results using MATLAB are also presented in this paper in order to justify the harmonic analysis. The simulation results along with the quantitative results shows the effectiveness of the proposed scheme for the cancelation or the elimination of the harmonics result in maximum harmonic mitigation, for high power utility applications, the 48-pulse converter is most fitting to improve the conversion efficiency, low di/dt and dv/dtand active and reactive power controllability.
A Comparative Study of Power Semiconductor Devices for Industrial PWM Inverters
Authors: Sena Gianluca , Marani Roberto , Gelao Gennaro , Perri Anna Gina
Published: February 2017

The growing demand of energy translates into efficiency requirements of energy conversion systems and electric drives. Both these systems are based on Pulse Width Modulation (PWM) Inverter. In this paper we firstly present the state of art of the main types of semiconductors devices for Industrial PWM Inverter. In particular we examine the last generations of Silicon Carbide (SiC) MOSFETs and Insulated Gate Bipolar Transistors (IGBTs) and we present a comparison between these devices, obtained by SPICE simulations, both for static characteristics at different temperatures and for dynamic ones at different gate resistance, in order to identify the one which makes the PWM inverter more efficient.
Augmentation of Muscle Blood Flow by Ultrasound Cavitation Is Mediated by ATP and Purinergic Signaling
Authors: Belcik J. Todd , Davidson Brian P. , Xie Aris , Wu Melinda D. , Yadava Mrinal , Qi Yue , Liang Sherry , Chon Chae Ryung , Ammi Azzdine Y. , Field Joshua , Harmann Leanne , Chilian William M. , Linden Joel , Lindner Jonathan R.
Published: February 2017

Background:

Augmentation of tissue blood flow by therapeutic ultrasound is thought to rely on convective shear. Microbubble contrast agents that undergo ultrasound-mediated cavitation markedly amplify these effects. We hypothesized that purinergic signaling is responsible for shear-dependent increases in muscle perfusion during therapeutic cavitation.

Methods:

Unilateral exposure of the proximal hindlimb of mice (with or without ischemia produced by iliac ligation) to therapeutic ultrasound (1.3 MHz, mechanical index 1.3) was performed for 10 minutes after intravenous injection of 2×10
8
lipid microbubbles. Microvascular perfusion was evaluated by low-power contrast ultrasound perfusion imaging. In vivo muscle ATP release and in vitro ATP release from endothelial cells or erythrocytes were assessed by a luciferin-luciferase assay. Purinergic signaling pathways were assessed by studying interventions that (1) accelerated ATP degradation; (2) inhibited P2Y receptors, adenosine receptors, or K
ATP
channels; or (3) inhibited downstream signaling pathways involving endothelial nitric oxide synthase or prostanoid production (indomethacin). Augmentation in muscle perfusion by ultrasound cavitation was assessed in a proof-of-concept clinical trial in 12 subjects with stable sickle cell disease.

Results:

Therapeutic ultrasound cavitation increased muscle perfusion by 7-fold in normal mice, reversed tissue ischemia for up to 24 hours in the murine model of peripheral artery disease, and doubled muscle perfusion in patients with sickle cell disease. Augmentation in flow extended well beyond the region of ultrasound exposure. Ultrasound cavitation produced an ≈40-fold focal and sustained increase in ATP, the source of which included both endothelial cells and erythrocytes. Inhibitory studies indicated that ATP was a critical mediator of flow augmentation that acts primarily through either P2Y receptors or adenosine produced by ectonucleotidase activity. Combined indomethacin and inhibition of endothelial nitric oxide synthase abolished the effects of therapeutic ultrasound, indicating downstream signaling through both nitric oxide and prostaglandins.

Conclusions:

Therapeutic ultrasound using microbubble cavitation to increase muscle perfusion relies on shear-dependent increases in ATP, which can act through a diverse portfolio of purinergic signaling pathways. These events can reverse hindlimb ischemia in mice for >24 hours and increase muscle blood flow in patients with sickle cell disease.

Clinical Trial Registration:

URL:
http://clinicaltrials.gov
. Unique identifier: NCT01566890.
Cardiac Overexpression of S100A6 Attenuates Cardiomyocyte Apoptosis and Reduces Infarct Size After Myocardial Ischemia‐Reperfusion
Authors: Mofid Azadeh , Newman Nadav S. , Lee Paul J. H. , Abbasi Cynthia , Matkar Pratiek N. , Rudenko Dmitriy , Kuliszewski Michael A. , Chen Hao H. , Afrasiabi Kolsoom , Tsoporis James N. , Gramolini Anthony O. , Connelly Kim A. , Parker Thomas G. , Leong‐Poi Howard
Published: February 2017

Background

Cardiomyocyte‐specific transgenic mice overexpressing S100A6, a member of the family of
EF
‐hand calcium‐binding proteins, develop less cardiac hypertrophy, interstitial fibrosis, and myocyte apoptosis after permanent coronary ligation, findings that support S100A6 as a potential therapeutic target after acute myocardial infarction. Our purpose was to investigate S100A6 gene therapy for acute myocardial ischemia‐reperfusion.

Methods and Results

We first performed in vitro studies to examine the effects of S100A6 overexpression and knockdown in rat neonatal cardiomyocytes. S100A6 overexpression improved calcium transients and protected against apoptosis induced by hypoxia‐reoxygenation via enhanced calcineurin activity, whereas knockdown of S100A6 had detrimental effects. For in vivo studies, human S100A6 plasmid or empty plasmid was delivered to the left ventricular myocardium by ultrasound‐targeted microbubble destruction in Fischer‐344 rats 2 days prior to a 30‐minute ligation of the left anterior descending coronary artery followed by reperfusion. Control animals received no therapy. Pretreatment with S100A6 gene therapy yielded a survival advantage compared to empty‐plasmid and nontreated controls. S100A6‐pretreated animals had reduced infarct size and improved left ventricular systolic function, with less myocyte apoptosis, attenuated cardiac hypertrophy, and less cardiac fibrosis.

Conclusions

S100A6 overexpression by ultrasound‐targeted microbubble destruction helps ameliorate myocardial ischemia‐reperfusion, resulting in lower mortality and improved left ventricular systolic function post–ischemia‐reperfusion via attenuation of apoptosis, reduction in cardiac hypertrophy, and reduced infarct size. Our results indicate that S100A6 is a potential therapeutic target for acute myocardial infarction.
Altered Blood Flow Response to Small Muscle Mass Exercise in Cancer Survivors Treated With Adjuvant Therapy
Authors: Didier Kaylin D. , Ederer Austin K. , Reiter Landon K. , Brown Michael , Hardy Rachel , Caldwell Jacob , Black Christopher , Bemben Michael G. , Ade Carl J.
Published: February 2017

Background

Adjuvant cancer treatments have been shown to decrease cardiac function. In addition to changes in cardiovascular risk, there are several additional functional consequences including decreases in exercise capacity and increased incidence of cancer‐related fatigue. However, the effects of adjuvant cancer treatment on peripheral vascular function during exercise in cancer survivors have not been well documented. We investigated the vascular responses to exercise in cancer survivors previously treated with adjuvant cancer therapies.

Methods and Results

Peripheral vascular responses were investigated in 11 cancer survivors previously treated with adjuvant cancer therapies (age 58±6 years, 34±30 months from diagnosis) and 9 healthy controls group matched for age, sex, and maximal voluntary contraction. A dynamic handgrip exercise test at 20% maximal voluntary contraction was performed with simultaneous measurements of forearm blood flow and mean arterial pressure. Forearm vascular conductance was calculated from forearm blood flow and mean arterial pressure. Left ventricular ejection time index (
LVET
i) was derived from the arterial pressure wave form. Forearm blood flow was attenuated in cancer therapies compared to control at 20% maximal voluntary contraction (189.8±53.8 vs 247.9±80.3 mL·min
−1
, respectively). Forearm vascular conductance was not different between groups at rest or during exercise. Mean arterial pressure response to exercise was attenuated in cancer therapies compared to controls (107.8±10.8 vs 119.2±16.2 mm Hg).
LEVT
i was lower in cancer therapies compared to controls.

Conclusions

These data suggest an attenuated exercise blood flow response in cancer survivors ≈34 months following adjuvant cancer therapy that may be attributed to an attenuated increase in mean arterial pressure.
Stroke With Unknown Time of Symptom Onset
Authors: Thomalla Götz , Boutitie Florent , Fiebach Jochen B. , Simonsen Claus Z. , Nighoghossian Norbert , Pedraza Salvador , Lemmens Robin , Roy Pascal , Muir Keith W. , Ebinger Martin , Ford Ian , Cheng Bastian , Galinovic Ivana , Cho Tae-Hee , Puig Josep , Thijs Vincent , Endres Matthias , Fiehler Jens , Gerloff Christian
Published: February 2017

Background and Purpose—

We describe clinical and magnetic resonance imaging (MRI) characteristics of stroke patients with unknown time of symptom onset potentially eligible for thrombolysis from a large prospective cohort.

Methods—

We analyzed baseline data from WAKE-UP (Efficacy and Safety of MRI-Based Thrombolysis in Wake-Up Stroke: A Randomized, Doubleblind, Placebo-Controlled Trial), an investigator-initiated, randomized, placebo-controlled trial of MRI-based thrombolysis in stroke patients with unknown time of symptom onset. MRI judgment included assessment of the mismatch between visibility of the acute ischemic lesion on diffusion-weighted imaging and fluid-attenuated inversion recovery.

Results—

Of 1005 patients included, diffusion-weighted imaging and fluid-attenuated inversion recovery mismatch was present in 479 patients (48.0%). Patients with daytime-unwitnessed stroke (n=138, 13.7%) had a shorter delay between symptom recognition and hospital arrival (1.5 versus 1.8 hours;
P
=0.002), a higher National Institutes of Stroke Scale score on admission (8 versus 6;
P
<0.001), and more often aphasia (72.5% versus 34.0%;
P
<0.001) when compared with stroke patients waking up from nighttime sleep. Frequency of diffusion-weighted imaging and fluid-attenuated inversion recovery mismatch was comparable between both groups (43.7% versus 48.7%;
P
=0.30).

Conclusions—

Almost half of the patients with unknown time of symptom onset stroke otherwise eligible for thrombolysis had MRI findings making them likely to be within a time window for safe and effective thrombolysis. Patients with daytime onset unwitnessed stroke differ from wake-up stroke patients with regards to clinical characteristics but are comparable in terms of MRI characteristics of lesion age.

Clinical Trial Registration—

URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT01525290. URL:
https://www.clinicaltrialsregister.eu
. Unique identifier: 2011-005906-32.
Vessel Wall Enhancement and Blood–Cerebrospinal Fluid Barrier Disruption After Mechanical Thrombectomy in Acute Ischemic Stroke
Authors: Renú Arturo , Laredo Carlos , Lopez-Rueda Antonio , Llull Laura , Tudela Raúl , San-Roman Luis , Urra Xabier , Blasco Jordi , Macho Juan , Oleaga Laura , Chamorro Angel , Amaro Sergio
Published: February 2017

Background and Purpose—

Less than half of acute ischemic stroke patients treated with mechanical thrombectomy obtain permanent clinical benefits. Consequently, there is an urgent need to identify mechanisms implicated in the limited efficacy of early reperfusion. We evaluated the predictors and prognostic significance of vessel wall permeability impairment and its association with blood–cerebrospinal fluid barrier (BCSFB) disruption after acute stroke treated with thrombectomy.

Methods—

A prospective cohort of acute stroke patients treated with stent retrievers was analyzed. Vessel wall permeability impairment was identified as gadolinium vessel wall enhancement (GVE) in a 24- to 48-hour follow-up contrast-enhanced magnetic resonance imaging, and severe BCSFB disruption was defined as subarachnoid hemorrhage or gadolinium sulcal enhancement (present across >10 slices). Infarct volume was evaluated in follow-up magnetic resonance imaging, and clinical outcome was evaluated with the modified Rankin Scale at day 90.

Results—

A total of 60 patients (median National Institutes of Health Stroke Scale score, 18) were analyzed, of whom 28 (47%) received intravenous alteplase before mechanical thrombectomy. Overall, 34 (57%) patients had GVE and 27 (45%) had severe BCSFB disruption. GVE was significantly associated with alteplase use before thrombectomy and with more stent retriever passes, along with the presence of severe BCSFB disruption. GVE was associated with poor clinical outcome, and both GVE and severe BCSFB disruption were associated with increased final infarct volume.

Conclusions—

These findings may support the clinical relevance of direct vessel damage and BCSFB disruption after acute stroke and reinforce the need for further improvements in reperfusion strategies. Further validation in larger cohorts of patients is warranted.
Piracy and Empire: The Campaign against Piracy, the Development of International Law and the British Imperial Mission
Authors: Mulligan Michael
Published: February 2017

This article will examine the issue of piracy and how the prohibition of piracy developed in international law from the 19th century onwards. The campaigns against piracy in the 19th century influenced the development of international law into the 21st century with the prohibition on piracy achieving the status of peremptory norm ‘jus cogens’ under international law. The anti-piracy campaign of the British led to the signing of treaties which, although ostensibly designed to prohibit the trade, had the effect of consolidating British power and influence over the Gulf States and furthered imperial interests there. The campaign also further contributed to the notion of the ‘civilising mission’. The legacy of the campaigns reverberate in the contemporary debates about piracy, particularly in relation to the so-called pirates who operate off the west coast of Africa.
Group Politics in Global Development Policy: From the Millennium Development Goals to the Post-2015 Development Agenda
Authors: Farrell Mary
Published: February 2017

This article examines the group politics in global development policy from the Millennium Development Goals (mdgs) to the Sustainable Development Goals (sdgs). The discussion tracks the actors and forces that shaped both sets of goals, and highlights the centrality of multilateral processes in framing the background for the interplay of group politics. With the expansion in the number and diversity of actors, and the United Nations system facilitating the engagement of multiple actors, ultimately the negotiation of the sdgs reflected a new diplomacy derived from mediation of multiple interests within a multilateral context.
Behaviour, Development and Evolution
Authors: Bateson Patrick
Published: February 2017

The role of parents in shaping the characters of their children, the causes of violence and crime, and the roots of personal unhappiness are central to humanity. Like so many fundamental questions about human existence, these issues all relate to behavioural development. In this lucid and accessible book, eminent biologist Professor Sir Patrick Bateson suggests that the nature/nurture dichotomy we often use to think about questions of development in both humans and animals is misleading. Instead, he argues that we should pay attention to whole systems, rather than to simple causes, when trying to understand the complexity of development.

In his wide-ranging approach Bateson discusses why so much behaviour appears to be well- designed. He explores issues such as ‘imprinting’ and its importance to the attachment of offspring to their parents; the mutual benefits that characterise communication between parent and offspring; the importance of play in learning how to choose and control the optimal conditions in which to thrive; and the vital function of adaptability in the interplay between development and evolution.

Bateson disputes the idea that a simple link can be found between genetics and behaviour. What an individual human or animal does in its life depends on the reciprocal character of its transactions with the world about it. This knowledge also points to ways in which an animal's own behaviour can provide the variation that influences the subsequent course of evolution.

This has relevance not only for our scientific approaches to the systems of development and evolution, but also on how humans change institutional rules that have become dysfunctional, or design public health measures when mismatches occur between themselves and their environments. It affects how we think about ourselves and our own capacity for change.
Wallenstein
Authors: Schiller Friedrich
Published: February 2017

By the time Frederich Schiller came to write the Wallenstein trilogy, his reputation as one of Germany’s leading playwrights was all but secured. Consisting of Wallenstein’s Camp, The Piccolomini and The Death of Wallenstein, this suite of plays appeared between 1798 and 1799, each production under the original direction of Schiller’s collaborator and mentor, Johann Wolfgang (von) Goethe. Across the three plays, which are now commonly performed and printed together, Schiller charts the thwarted rebellion of General Albrecht von Wallenstein. Based loosely on the events of the Thirty Years' War, the trilogy provides a unique vantage on an army’s loyalty to their commander and the machinations and intrigues of international diplomacy, giving insight into the military hero who is placed on the threshold between these forces as they are increasingly pitted against one another.

The Wallenstein trilogy, formally innovative and modern beyond its time, is a brilliant study of power, ambition and betrayal. In this new translation—the latest in a long line of distinguished English translations of the play, starting with Coleridge's in Schiller's lifetime—Flora Kimmich succeeds in rendering what is often a difficult source text into language that is at once accessible and enjoyable. Coupled with a complete and careful commentary and a glossary, both of which are targeted to undergraduates, and accompanied by an authoritative introductory essay by Roger Paulin, this edition also includes embedded readings in German of the play and links to the original German text. It will be an invaluable resource for students of German, European literature and history, and military history, as well as to all readers approaching this important set of plays for the first time.
Characterizing Ventilation and Exposure in Street Canyons Using Lagrangian Particles
Authors: Lo K. W. , Ngan K.
Published: February 2017

The residence time measures the rate at which a pollutant escapes from a region of interest. Previous studies of urban ventilation have estimated the mean residence time from Eulerian data by assuming a spatially homogeneous pollutant field. Using a large-eddy simulation and a Lagrangian particle model, the residence and exposure times are calculated for an idealized street canyon in the skimming-flow region and a deep street canyon within a realistic urban area. For both domains, the mean residence time is on the order of a canyon circulation time scale, while the mean exposure time, which includes re-entrainment and characterizes the total time spent by a pollutant in a region of interest, is about 20% longer. Intensive quantities such as the Lagrangian visitation factor and return coefficient indicate that re-entrainment is modest. Probability distribution functions of the exposure and residence times are nearly exponential for both domains, in accord with pure diffusion and single-time-scale, vertical-exchange parameterizations. It is argued that, by analogy with Brownian motion, the mean residence and exposure times are set primarily by the mean circulation rather than the turbulence when the flow approximates that within a two-dimensional street canyon.
Cloud–Atmospheric Boundary Layer–Surface Interactions on the Greenland Ice Sheet during the July 2012 Extreme Melt Event
Authors: Solomon Amy , Shupe Matthew D. , Miller Nathaniel B.
Published: February 2017

Regional model simulations of the 10–13 July 2012 extreme melt event over the Greenland Ice Sheet (GIS) are used to investigate how low-level liquid-bearing clouds impact surface energy fluxes, and therefore the energy available for melt. A sensitivity study in which the radiation code is modified so that cloud liquid and ice do not emit, absorb, or reflect radiation is used to identify cloud impacts beyond the cloud radiative effect. It is found that Arctic mixed-phase stratocumuli are not produced in the sensitivity experiment, highlighting that cloud radiative fluxes are required to maintain the clouds. A number of feedbacks are found that damp the warming effect of the clouds. Thin mixed-phase clouds increase the downward longwave fluxes by 100 W m−2, but upward daytime surface longwave fluxes increase by 20 W m−2 (60 W m−2 at night) and net shortwave fluxes decrease by 40 W m−2 (partially due to a 0.05 increase in surface albedo), leaving only 40 W m−2 available for melt. This 40 W m−2 is distributed between the turbulent and conductive ground fluxes, so it is only at times of weak turbulent fluxes (i.e., at night or during melt) that this energy goes into the conductive ground flux, providing energy for melt. From these results it is concluded that it is the integrated impact of the clouds over the diurnal cycle (the preconditioning of the snowpack by the clouds at night) that made melt possible during this 3-day period. These findings are extended to understand the pattern of melt observed over the GIS.
Ceilometer-Based Analysis of Shanghai’s Boundary Layer Height (under Rain- and Fog-Free Conditions)
Authors: Peng Jie , Grimmond C. S. B. , Fu Xinshu , Chang Yuanyong , Zhang Guangliang , Guo Jibing , Tang Chenyang , Gao Jie , Xu Xiaodong , Tan Jianguo
Published: February 2017

To investigate the boundary layer dynamics of the coastal megacity Shanghai, China, backscatter data measured by a Vaisala CL51 ceilometer are analyzed with a modified ideal curve fitting algorithm. The boundary layer height zi retrieved by this method and from radiosondes compare reasonably overall. Analyses of mobile and stationary ceilometer data provide spatial and temporal characteristics of Shanghai’s boundary layer height. The consistency between when the ceilometer is moving and stationary highlights the potential of mobile observations of transects across cities. An analysis of 16 months of zi measured at the Fengxian site in Shanghai reveals that the diurnal variation of zi in the four seasons follows the expected pattern; for all seasons zi starts to increase at sunrise, reflecting the influence of solar radiation. However, the boundary layer height is generally higher in autumn and winter than in summer and spring (mean hourly averaged zi for days with low cloud fraction at 1100–1200 local time are 900, 654, 934, and 768 m for spring, summer, autumn, and winter, respectively). This is attributed to seasonal differences in the dominant meteorological conditions, including the effects of a sea breeze at the near-coastal Fengxian site. Given the success of the retrieval method, other ceilometers installed across Shanghai are now being analyzed to understand more about the spatial dynamics of zi and to investigate in more detail the effects of prevailing mesoscale circulations and their seasonal dynamics.
Rain Evaporation Rate Estimates from Dual-Wavelength Lidar Measurements and Intercomparison against a Model Analytical Solution
Authors: Lolli S. , Di Girolamo P. , Demoz B. , Li X. , Welton E. J.
Published: February 2017

Rain evaporation, while significantly contributing to moisture and heat cloud budgets, is a still poorly understood process with few measurements presently available. Multiwavelength lidars, widely employed in aerosols and clouds studies, can also provide useful information on the microphysical characteristics of light precipitation, for example, drizzle and virga. In this paper, lidar measurements of the median volume raindrop diameter and rain evaporation rate profiles are compared with a model analytical solution. The intercomparison reveals good agreement between the model and observations, with a correlation between the profiles up to 65% and a root-mean-square error up to 22% with a 5% bias. Larger discrepancies are due to radiosonde soundings different air masses and model assumptions no more valid along the profile as nonsteady atmosphere and/or appearance of collision–coalescence processes. Nevertheless, this study shares valuable information to better characterize the rain evaporation processes.
Teaching electronics to first-year non-electrical engineering students
Authors: Dahnoun Naim
Published: February 2017

Teaching electronics is not only for electrical and electronics students but also for mechanical, aerospace, engineering design, civil and engineering mathematics programmes, which are likely to have electronics units as part of their curriculum. To teach electronics for these non-electronic programmes is very challenging in many aspects. First, the electronics unit has to satisfy the learning outcomes for each programme. Second, the student’s motivation is normally very low since electronics is not the career the students would like to pursue. Third, the timetabling can be an issue when a large number of students are enrolled; for instance, at the University of Bristol, over 340 students are registered for the electronics unit. Due to this large number and the capacity of the electrical laboratory, students will have laboratory experiments timetabled in different weeks and some may have laboratory experiments before the lectures are covered. Finally, a method of assessing this large number of students has to be put into place. In this paper, the content of the unit including the laboratory experiments, the methods of course delivery and the assessment methods are justified. Also, since students learn differently and have a variety of motivations, a combination of teaching methods has to be found to satisfy more students and improve the learning outcomes.
Line managers in industrial relations: Where are we now and where to next?
Authors: Townsend Keith , Hutchinson Sue
Published: February 2017

Interactions between line managers and subordinate employees are fundamental to the employment relationship and, therefore, to industrial relations as a field of both study and practice. Human resource management literature has focused on the responsibilities line managers have as implementers of employment policy and practice, for example in dealing with grievance and disciplinary matters, communication and involvement, the application of discrimination policies, and the management of pay. Thus, it is surprising that this body of managers has been neglected in recent industrial relations research. This article fits the theme of the special issue by providing an overview of ‘where we are’ and sets out a research agenda of ‘Where to next?’, for the study of line managers in industrial relations research.
Reliability and Construct Validity of the Portuguese Version of the Psychological Capital Questionnaire
Authors: Antunes Ana Cristina , Caetano António , Pina e Cunha Miguel
Published: February 2017

The Psychological Capital Questionnaire (PCQ) is the most commonly used measure for assessing psychological capital in work settings. Although several studies confirmed its factorial validity, most validation studies only examined the four-factor structure preconized by Luthans, Youssef, and Avolio, not attending to empirical evidence on alternative factorial structures. The present study aimed to test the psychometric properties of the Portuguese version of the PCQ, by using two independent samples (NS1 = 542; NS2 = 115) of Portuguese employees. We conducted a series of confirmatory factor analyses and found that, unlike previous findings, a five-factor solution of the PCQ best fitted the data. The evidence obtained also supported the existence of a second-order factor, psychological capital. The coefficients of internal consistency, as measured by Cronbach’s alpha, were adequate and test–retest reliability suggested that the PCQ presented a lower stability than personality factors. Convergent validity, assessed with average variance extracted, revealed problems in the optimism subscale. The discriminant validity of the PCQ was confirmed by its correlations with Positive and Negative Affect and Big Five personality factors. Hierarchical regression analyses showed that this measure has incremental validity over personality and affect when predicting job performance.
Analysis of the damping property of warp-knitted spacer fabrics under damped free vibration
Authors: Chen Chaoyu , Chen Junli , Sun Fengxin , Yang Huijuan , Du Zhaoqun
Published: February 2017

The main content dealt with in this paper was to carry out a theoretical analysis of the damping property of spacer fabric used as cushion materials. A free vibration test was conducted and the corresponding model was established based on a single-degree-of-freedom (SDOF) system by considering the viscous–elastic behavior of spacer fabric during free vibration. Displacement–time curves of spacer fabric were calculated by a second-order integral of acceleration and time curves recorded by an accelerator sensor. Then, vibration indexes, including the damping ratio, damping coefficient, logarithmic decrement and free vibration period, were featured based on a SDOF model. The experimental results of damping ratio and displacement–time curves were compared with the theoretical results. It indicated that the vibration model was effective to characterize the free vibration of spacer fabric. Moreover, the effects of different structural parameters, including thickness, filament diameter, area density and inclination angle and arrangement of spacer filaments, of the spacer fabric on the damping property were also investigated. This is helpful to better design spacer fabrics with a good damping property.
K-12 Teacher Perceptions Regarding the Flipped Classroom Model for Teaching and Learning
Authors: Gough Evan , DeJong David , Grundmeyer Trent , Baron Mark
Published: February 2017

A great deal of evidence can be cited from higher education literature on the effectiveness of the flipped classroom; however, very little research was discovered on the flipped classroom at the K-12 level. This study examined K-12 teachers’ perceptions regarding the flipped classroom and differences in teachers’ perceptions based on grade level and content area taught. A researcher-developed survey instrument was used to collect data from K-12 teachers that utilize a flipped classroom in Southwest and South Central Minnesota. Survey participants totaled 44, which included 27 high school teachers, 15 middle school teachers, and 2 teachers that identified as other. It was found that participants perceived that the flipped classroom creates time for varied instructional techniques, including active learning and higher order thinking, along with increased student-to-teacher interaction. The insights from the study inform teachers in the field about benefits and best practices in regard to the flipped classroom instructional model.
Developing an English Mobile Learning Attitude Scale for Adult Learners
Authors: Liu Tzu-Ying
Published: February 2017

In recent years, with the rapid development of mobile devices, mobile learning (m-learning) has becoming another popular topic. There is a strong need for both researchers and educators to be aware of adult learners’ attitudes toward English mobile learning, yet relevant studies on mobile learning to promote English learning for adult learners are scarce. The purpose of this study was to describe the development of an English Mobile Learning attitude scale for adult learners in higher education. A preliminary version of a scale to measure attitudes toward English mobile learning was developed and piloted on 190 adult learners who were attending the continuing education situations in Southern Taiwan. Initial item selection produced a pilot scale consisting of 36 Likert items. Subsequently, an expert review panel, item analysis, and factor analysis revealed four structurally independent attitude constructs and justified retention of 21 of the original items. The full instrument was found to have both a high internal reliability coefficient (.93) and significant construct validity ( p < .001).
Integrating Technology-Enhanced Collaborative Surfaces and Gamification for the Next Generation Classroom
Authors: Barneva Reneta P. , Kanev Kamen , Kapralos Bill , Jenkin Michael , Brimkov Boris
Published: February 2017

We place collaborative student engagement in a nontraditional perspective by considering a novel, more interactive educational environment and explaining how to employ it to enhance student learning. To this end, we explore modern technological classroom enhancements as well as novel pedagogical techniques which facilitate collaborative learning. In our setup, the traditional blackboard or table is replaced by a digitally enabled interactive surface such as a smart board or a tabletop computer. The information displayed on the digital surface can be further enhanced with augmented reality views through mobile apps on student smartphones. We also discuss ways to enhance the instructional process through elements of game mechanics and outline an experimental implementation. Finally, we discuss an application of the proposed technological and pedagogical methods to human anatomy training.
Virtual Learning Environments in Social Psychology
Authors: Stansbury Jessica A.
Published: February 2017

An interactive learning module was developed and implemented in a social psychology course to teach concepts of the self via self-exploration and game play using The SIMS3. Students volunteered to play the computer video game throughout a 5-week summer session as a supplement to reading the chapter in the textbook. Results revealed that students who played the game demonstrated a significant increase in content knowledge compared to those who engaged in other active learning projects; interestingly, students who played the game reported lower levels of confidence with course material. Student’s overall perceived experience (e.g., engagement, fun) of the learning module was also explored.