Inflow Pattern Research Articles

Scaling of Incidence Variations With Inlet Distortion for a Transonic Axial Compressor

Abstract This paper numerically explores the manner in which blade row inlet incidence variation scales with various distortion patterns and intensities. The objectives are to (1) identify the most appropriate parameter whose circumferential variation can be used to assess scaling relationships of a transonic compressor and (2) use this parameter to evaluate two types of non-uniform inflow patterns, vertically stratified total pressure distortions and radially stratified total enthalpy and total pressure distortions. A body force model of the blade rows is employed to reduce computational cost; the approach has been shown to capture distortion transfer and to be able to predict upstream flow redistribution with inlet distortion. Diffusion factor is shown to be an inadequate proxy for streamline loss generation in non-uniform flow, leading to the choice of incidence angle variations as the metric for which we assess scaling relationships. Posteriori scaling of circumferential flow angle variation based on the maximum incidence excursion for varying distortion intensity yields an accurate method for prediction of the impact for other distortion intensities; linear regression of the maximum variation in incidence around the annulus as a function of distortion intensity had R2 > 0.97 for all spanwise locations examined in both the rotor and stator for both vertically and radially stratified distortions. However, changes to far upstream distortion shape yield highly non-linear incidence variation scaling; the results suggest that the pitchwise gradients of far upstream total pressure govern the degree of linearity for incidence variation scaling.

The Study of the Hurricane-Induced Storm Surge and Bay-Ocean Exchange Using a Nesting Model

Lagoon systems are more heavily impacted by hurricanes, whereas the relevant storm surge modeling studies have been paid little attention to lagoon systems and the storm-induced exchange in lagoon systems is even less understood. To address this gap, a three-dimensional unstructured grid-based model was configured for the Maryland Coastal Bays, a typical lagoon system with two unique inlets (Ocean City Inlet (OCI) and Chincoteague Inlet (CI)), to investigate how Hurricane Sandy impacted inlet dynamics. A nesting model framework was applied to provide the necessary remote forcing from a large model domain and maintain the intricate shoreline and bathymetry of an inner model domain. Results indicated that the flux patterns varied in response to the change in wind direction and rising/falling high water levels from the coastal ocean, rather than a single flow pattern during the passage of Sandy. From October 29 05:00 to 17:00 UTC, mild (> 10 m/s) and strong (> 15 m/s) northerly winds accompanied by the rising high water level from the coastal ocean promoted a mean inflow pattern at the OCI and a mean outflow pattern at the CI. Strong southwesterly winds (> 15 m/s) dominated in the bays from October 30 03:00 to 15:00 UTC. Under strong southwesterly winds and falling high water levels from the coastal ocean, flux was transported landward at the CI and seaward at the OCI. Sensitivity experiments on various storm temporal scales showed that a net inflow pattern occurred in the bays, and the net exchange amounts became smaller in response to longer storm durations. Residual effect of relatively high river flow from Sandy could still influence the salinity at the OCI, whereas the CI salinity was not affected by river flow owing to a long distance between the CI and river locations.

P800 Effect of Valsalva Maneuver on echocardiographic systolic and diastolic parameters in patients with acute coronary syndrome, a comparison between normal and high ventricular filling pressures

Abstract Funding Acknowledgements Nil OnBehalf Nil Introduction Echocardiography is used as a useful and common method for the assessments of left and right ventricular (LV & RV) systolic and diastolic functions. Valsalva Maneuver (VM) with the increase in the intra-thoracic and intra-abdominal pressure is often used as a simple, inexpensive and non-invasive method to diagnose some clinical conditions such as heart murmurs. However, in terms of echocardiography, the use of VM is limited to a few parameters for many years. On the other hand, blood level of N-Terminal Pro–B-Type Natriuretic Peptide (NT Pro–BNP) indirectly discriminates normal or high ventricular filling pressure (FP). Purpose The purposes of this research is to provide a comprehensive review of the technique and to compare the effect of VM in ACS patients, with and without elevated FP on either RV and LV diastolic and systolic echocardiographic parameters. Methods Thirty-eight patient, who were diagnosed with possible ACS; Unstable Angina Pectoris, NSTEMI and STEMI, underwent coronary angiography enrolled in this double–blinded clinical trial study. The mild Coronary Artery Disease (CAD) with normal levels of NT Pro–BNP were included in study group one and patients with significant CAD and high level of NT Pro–BNP who underwent PCI were included in study group two. All the systolic and diastolic indicators of both ventricles, totally twenty-four parameters those had mentioned in the academic literature previously, have been evaluated; once before Valsalva and once during stage 2 of the maneuver. Echocardiography is performed by an advanced echo machine and by an expert cardiologist- echocardiographer, which the recorded images were reviewed by the second echocardiographer separately. Results Between the two groups, LV parameter analysis showed significant difference in LV EF pre and post VM. However, there was statistically insignificant difference regarding other systolic as well as diastolic parameters. Between the two groups, RV parameters analysis showed no significant difference in systolic and diastolic parameters pre and post VM. Conclusion To the best of our knowledge, this is the first report assessing post VM changes in four chambers as well as mitral and tricuspid valves parameters in ACS patients with normal versus high level of FP. Previously, LV diastolic dysfunction and Doppler mitral inflow pattern correlation with VM were approved. In the present study, in addition to those known findings from before, except the LV ejection fraction (LVEF) that showed there was statistically significant difference in pre– and post-VM, other systolic parameters, as well as diastolic indicators in either RV and LV, were identical. Therefore, we do not recommend conducting Valsalva maneuver on the rest of the other parameters to diagnose systolic and diastolic dysfunction in ACS patients with mild versus significant CAD who were assumed to have normal or elevated filling pressures.

P1583 Usefulness of remote intrathoracic impedance alerts for echo-guided CRT optimization

Abstract Background Cardiac resynchronisation therapy (CRT) is a strong recommendation in heart failure (HF) patients having sinus rhythm, left bundle branch block, QRS duration ≥ 120 ms and left ventricular (LV) ejection fraction (EF) ≤ 35%, despite optimized medication. Echocardiographic parameters still have a controversial role in the selection of patients ongoing CRT, and no single parameter is recommended to identify a positive CRT response. Even their role in the management after implantation remains still troubleshooting. Atrioventricular (AV) and interventricular (VV) delay reprogramming could be a variable that may influence CRT outcome and, although a systematic AV and VV optimization is not required, it could be useful in selected patients. Remote monitoring networks allow HF patients having a CRT device to be constantly monitored, and notifications of some intrathoracic impedance indexes, may be helpful in the management of HF patients. Purpose To evaluate the usefulness of intrathoracic impedance notifications in the selection of HF patients to have echo-guided AV and/or VV delays optimization, the following study was undertaken. Methods 27 CRT patients having an intrathoracic impedance enabled remote monitoring, with at least one impedance notification during the first six months from implantation, were considered for study. The primary endpoint was a composite of improvement in NYHA functional class and EF, reduction of LV end-systolic volume and rehospitalization for decompensated HF. Secondary endpoint was the effectiveness of echo-guided dealys optimization based on intrathoracic impedance alerts. The AV delay optimization was mainly driven by mitral inflow pattern, whereas VV delay optimization was guided by the assessment of LV synchrony using color Tissue Doppler Imaging (TDI). Patients were weekle evaluated through remote monitoring network over a six-month follow-up. LVEF and LV end-systolic volume were determind at baseline and after six months. Results After the six-month follow-up, an improvement of at least 1 NYHA functional class was obtained in 23 patients (85%), while 2 patients (7.4%) experienced an improvement of two NYHA classes. In 21 Patients (77.7%) LVEF increased at least 5%. Optimization was associated with an average 11.9 ± 6.4% increas in EF, from a mean baseline of 28.2 ± 3.2% to 37.8 ±6.2%. End-systolic volume decreased from 161.56 ± 9.87 ml to 143.22 ± 15.83 ml. Among the 27 patients with impedance alerts at baseline, only 6 (22.2%) reported new notifications during follow-up, with a significant reduction (p < 0.03) after optimization. Conclusions Intrathoracic impedance monitoring improved the selection of non responders feasible to have echo-guided AV and/or VV delays optimization. Functional status and LVEF increased. Although time-consuming, this multidisciplinary network may increase close cooperation between electrophysiologist and HF physicians to better manage HF patients having a CRT system implanted.

358 Interaction between Infarct Size and Diastolic Dysfunction following Myocardial Infarction

The inter-relationships between infarct size and diastolic dysfunction following MI have not been well studied. This study sought to define the determinants of severe DD (restrictive mitral inflow pattern on Doppler echocardiography [RFP]) in patients with first-ever MI, with particular emphasis on the impact of infarct size. Retrospective single-centre study including consecutive patients with a first-ever non-ST-elevation-MI (NSTEMI) or ST-elevation-MI (STEMI) (n=477). Peak Troponin-I (Peak-TnI) was used as principal measure of infarct size, whilst LVEF and wall motion score index (WMSI) were regarded as surrogate measures. Echocardiography was performed within 24 hours of admission for all patients. RFP was defined as E/A ratio >2.0 or E/A ratio >1.5 and E-wave deceleration time <140ms. A total of sixty-nine patients (14.5%) had RFP. Peak-TnI levels were higher in the RFP group (32.6±32.7 versus 16.9±25.2μg/L, p<0.001). In sequential multivariable models incorporating significant clinical, angiographic and LV size-related variables, Peak-TnI (OR 1.98, p=0.001), WMSI (OR 2.34, p=0.048) and LVEF (OR 0.97,p=0.044) were weak independent correlates of RFP. Presence of diabetes was also an independent predictor in all the models constructed. When patients were stratified according to an LVEF of 50%, 39% of RFP patients had a preserved LVEF (RFP/preserved EF group), and these patients had lower Peak-TnI levels compared to the RFP/reduced EF group (14.4±18.7 vs 44.5±35.5 μg/L, p=0.001). The relationship between infarct size and LV diastolic dysfunction is bimodal: patients with high Troponin/ low LVEF have predominantly infarct related diastolic dysfunction; whereas patients with low TnI/ preserved LVEF have predominantly pre-existing diastolic dysfunction.

Dam Inflow Prediction by using Artificial Neural Network Reservoir Computing

A multipurpose dam serves multiple modalities like agriculture, hydropower, industry, daily usage. Generally dam water level and inflow are changing throughout the year. So, multipurpose dams require effective water management strategies in place for efficient utilization of water. Discrepancy in water management may lead to significant socio-economic losses and may have effect on agriculture patterns in surrounding areas. Inflow is one of the dynamic driving factors in water management. So accurate inflow forecasting is necessary for effective water management. For inflow forecasting various methods are used by researchers. Among them Auto Regressive Integrated Moving Average (ARIMA) and Artificial Neural Network (ANN) techniques are most popular. Both of these techniques have shown significant contribution in various domains in regards to forecasting. But they have a common drawback in handling non-stationary inflow patterns. To address this drawback, in this work neural Reservoir Computing technique is used. In this work, Context reverberation network, also known as reservoir computing approach, is applied for inflow forecasting. It comprises of a dynamic neural reservoir. As the nature of a neural reservoir is dynamic, it can easily model complex nonstationary patterns along with stationary ones. Proposed model is applied on daily inflow data of Srisailam Dam which is a multipurpose dam. Here ARIMA and ANN models are compared with Reservoir Computing model. On various evaluation parameters Reservoir computing is proved better than ARIMA and ANN.

Commuter Travel Pattern to OUSL Nawala: A Case Study

This study intends to analyse the inflow pattern of commuters of OUSL Colombo Regional Center and Main University Nawala with their travel origins, and study their travel-mode patterns and travel nature. The study followed road side interviews, which was the most suitable method to be adopted for such study purpose. This was identified by an extensive literature survey. Pilot studies were conducted during midweek and weekends to identify the volume of walkers and motorists coming through the four gates of the university to get an idea on size of survey teams to conduct interviews and to decide how to locate survey teams around the entry gates during the main surveys. Main surveys were carried out on a Saturday (weekend) and a Wednesday (midweek), from 8:00 to 18:00 hours covering a 10-hour survey duration. According to the questionnaire, the walkers and motorists coming to OUSL through all four gates were interviewed and contacted more than 1000 respondents. This survey has captured around 58% of total arrivals during the weekend and 56% during midweek. It was observed that a total of 51% of university community came through Nugegoda. Most of them came from Kotte Divisional Secretaries division (zone no 7). It was observed that from the total arrivals, 82 % (weekend) and 66% (midweek) came from zone 7. Out of the community coming to the University for Study Purposes during weekends, 51% were males and 48% females; during midweek, 54% were males and 46% females. Around 74% of community coming to OUSL use buses, while 9% come by trains. As the final outcome of this study, a shuttle service of buses was designed to provide a better service to OUSL visitors during the rush hours (ie. 8:00 am to 10:00 pm). Shuttle services are proposed from some main towns. Through the study it was found that presently no adequate number of passengers use trains.

Relationship between left ventricular isovolumic relaxation flow patterns and mitral inflow patterns studied by using vector flow mapping

The purpose of this study was to investigate the relationship between isovolumic relaxation flow (IRF) patterns in left ventricle (LV) and mitral inflow patterns. Color Doppler loops were acquired for vector flow mapping in apical long-axis view in 57 patients with coronary artery disease, 31 patients with dilated cardiomyopathy, and 58 healthy controls. IRF patterns were classified into three categories: pattern A, apically directed flow; pattern B, bidirectional flow with small scattered vortices; and pattern C, a large vortex. All normals and patients with normal LV filling (n = 10) showed pattern A. Patients with impaired relaxation consisted of 31 (66%) patients having pattern A, 11 (23%) having pattern B, and 5 (11%) having pattern C. Patients with pseudonormal filling included 4 (31%) patients having pattern A, 7 (54%) having pattern B, and 2 (15%) having pattern C. In patients with restrictive filling, 14 (78%) showed pattern C, 4 (22%) showed pattern B, and no patient showed pattern A. IRF patterns were associated with LV filling patterns (χ2 = 52.026, p < 0.001). There are significant relationships between LV filling and IRF patterns. IRF patterns may provide an index for evaluation of LV diastolic function.

Flow sharing and turbulence phenomena in proton exchange membrane fuel cell stack headers

The distribution of the gas flow in a PEMFC stack is of paramount importance to the stack's performance and lifetime. Uneven flow distribution influences the flow rate through each cell, which in turn causes uneven distribution of the current flow of the entire cell stack and ultimately reduces the performance of the fuel cell stack. In this work, different simulation methods are compared, and large eddy simulations are selected to investigate the flow characteristics in a model stack and study the effects of operating conditions on flow sharing. The simulation results indicate different flow patterns in the inlet header and outlet header; the former features a turbulent entrance region that progressively transits to a laminar region, whereas the latter exhibits a complex flow with jets mixing downstream. Moreover, the flow patterns and distributions for different inlet/outlet configurations, i.e., U-type and Z-type, are investigated. The distribution of the flow through the unit cells for both configurations is different. The Z-type arrangement offers a more uniform flow distribution and has a smaller number of fluctuations than the U-type. The effects of different inlet flow velocity and jet inflow pattern are also studied. The findings from this work can provide guidelines to improve header design.

Restoring the natural flow regime of a large hydroelectric complex: Costs and considerations

Electricity generated from hydropower is considered a clean energy source because it is both renewable and non-carbon emitting. However, large hydroelectric complexes can generate a wide range of deleterious impacts on downstream ecosystems. The purpose of this article is to describe an approach for estimating the system-wide electricity costs of altering the operation, called reoperation, of a large hydroelectric complex for the purpose of partially restoring natural downstream ecosystems. We study the effect of reoperating the Akosombo hydroelectricity complex in Ghana because the Akosombo plays a critical role in regional electricity production and the construction of the Akosombo Dam substantially altered the natural flow of the Volta River. We do this by comparing the observed operations for a one-year period spanning 2004–2005 with reoperation scenarios that have the goal of making the dam outflow pattern closer to the inflow pattern. We quantify the impact of these reoperation strategies on regional electricity costs using a calibrated model of productivity at the Akosombo Dam and a model of regional electricity generation and trade. We find that if annual generation stays essentially the same with increased wet season generation offsetting decreased dry season generation, the increase in annual costs to the West African Power Pool is about $20 million. If dam operation is altered to be as close to run of river as possible, annual generation decreases due to water spillage, and system-wide costs increase $155 million.

P1488Single wave mitral inflow pattern caused by left ventricular diastolic dyssynchrony in patients with heart failure

Abstract Background Mitral E and A waves could fuse to form a single wave in tachycardia. Patients with heart failure (HF) occasionally show single wave mitral inflow despite of non-tachycardiac condition. Purpose To investigate mechanisms of single wave mitral inflow in HF patients with sinus rhythm and normal heart rate. Methods A total of 60 HF patients, including 20 single wave (SW), 20 impaired relaxation (IR) and 20 pseudonormalized (PN) mitral inflow patterns were retrospectively enrolled. All the patients were in sinus rhythm under 85 bpm. Patients with bundle branch blocks and first-degree heart block were excluded. We compared basic echo measurements, magnitude of left ventricular (LV) diastolic dyssynchrony, isovolumic relaxation time (IRT) and BNP levels among 3 groups. Diastolic dyssynchrony was determined as standard deviation of interval between aortic valve closure and peak early diastolic wave of longitudinal strain across 16 LV myocardial segments using 2D speckle tracking echocardiography. Results There was no significant difference in heart rate among 3 groups. Patients with SW showed significantly large magnitude of diastolic dyssynchrony (4.1±1.1) compared to those with IR (2.7±0.7) and PN (2.9±0.9ms), respectively. Likewise, IRT of SW (7.1±2.7) was longer than IR (3.2±0.8) and PN (2.4±0.9ms). BNP level in patients with IR (153±111) was significantly lower than those with SW (558±432) and PN (523±263pg/ml). Representative cases Conclusion HF patients with SW could be caused by LV diastolic dyssynchrony and their BNP levels are comparable to those with PN.

EP09.05: Characteristic changes of the time interval of ventricular inflow patterns in the fetal growth restriction

EP09.05: Characteristic changes of the time interval of ventricular inflow patterns in the fetal growth restriction

Tricuspid regurgitation and long-term clinical outcomes.

Tricuspid regurgitation (TR) is a frequent echocardiographic finding; however, its effect on outcome is unclear. The objectives of current study were to evaluate the impact of TR severity on heart failure hospitalization and mortality. We retrospectively reviewed consecutive echocardiograms performed between 2011 and 2016 at the Tel-Aviv Medical Center. TR severity was determined using semi-quantitative approach including colour jet area, vena contracta width, density of continuous Doppler jet, hepatic vein flow pattern, trans-tricuspid inflow pattern, annular diameter, right ventricle, and right atrial size. Major comorbidities, re-admissions and all-cause mortality were extracted from the electronic health records. The final analysis included 33305 patients with median follow-up period of 3.34 years (interquartile range 2.11-4.54). TR (≥mild) was present in 31% of our cohort. One-year mortality rates were 7.7% for patients with no/trivial TR, 16.8% for patients with mild TR, 29.5% for moderate TR, and 45.6% for patients with severe TR (P < 0.001). Univariate and multivariate analyses demonstrated a positive correlation between TR severity and overall mortality and rates of heart failure re-admission after adjustment for potential confounders. The proportional hazards method for overall mortality showed that patients with moderate [hazard ratio (HR) 1.15, 95% confidence interval (CI) 1.02-1.3, P = 0.024] and severe TR (HR 1.43, 95% CI 1.08-1.88, P = 0.011) had a worse prognosis than those with no or minimal TR. The presence of any degree of TR is associated with adverse clinical outcome. At least moderate TR is independently associated with increased mortality.

Dynamic patterns of self-organization inflow in collisionless magnetic reconnection

We investigate the evolution of reconnection inflow using a fully kinetic approach. Three types of inflow are detailed, namely the collapse inflow, the vortex inflow and the reverse inflow. They are formed dynamically at different stages of reconnection via self-organizing processes, but are closely interrelated with each other. The reconnection starts from a small perturbation, which can trigger off a chain of pressure-induced collapses propagating into the inflow region. The pressure gradient results in the collapse inflow toward the reconnection site. Then due to the continuous injection of hot plasma carried by the reconnection outflows, the expanding exhaust causes its adjacent region to be compressed. The combined effects of the compression and the reflection of conducting walls lead to the formation of the vortex inflow. Subsequently, the reverse inflow develops gradually within the exhaust. Under the modulation of these inflows, the reconnection rate shows a transient oscillation. We also discussed the possible occurrence of the self-organization inflow available in different contexts.

三言 속 君主의 문학작품으로의 유입 양상과 현대적 수용 고찰

본고는 ‘삼언 역사인물의 현대적 수용 양상 연구’라는 대주제의 일환으로 ‘삼언 속 군주’를 소재로 한 작품을 집중 연구하면서, 소설 속 인물로 재탄생한 여섯 군주 蕭衍･楊廣･錢鏐･郭威･趙匡胤･完顔亮 중 역사와 문학의 경계를 넘어서 현대에 이르기까지 중국 대중들에게 널리 회자되고 있는 군주 ‘양광’과 ‘조광윤’을 집중 조명하고자 하였다.BR 이를 위해 필자는 두 군주가 소설 속 인물로 탄생한 ‘삼언’ 소설 〈隋煬帝逸游召譴〉(《醒世恒言》 제24권)과 〈趙太祖千里送京娘〉(《警世BR通言》 제21권)을 비교･분석의 중심에 두고, 양광과 조광윤의 역사적 기록과 두 인물이 문학작품 속 인물로 변모해나간 필기류･화본･희곡 등의 諸 문헌들을 비교함으로써 이들의 문학작품 속 유입 과정을 살펴보았다. 또한 이들 군주가 현대에 이르러 중국의 영화･연극･드라마･게임과 같은 다양한 문화콘텐츠를 통해 대중과 어떻게 소통하고 있는지 고찰함으로써 그 문화적 함의를 들여다보고자 하였다.

Comparison of flow field and combustion in single and double side ported rotary engine

Intake and exhaust ports have great importance on performance of the rotary engines, since flow structure of the combustion chamber is depended on position and geometry of these ports. Similar to reciprocating engines that have different in-flow patterns according to valve characteristics of the engine, the flow patterns inside the combustion chamber change according to port position, quantity and channel geometry of rotary engines. In this study, air flow inside a double-side-ported rotary engine including 4 inlet and 2 exhaust ports with ports was numerically investigated by using computational fluid dynamic techniques. Numerical flow field results were compared with experimental data presented in the literature. Change of volumetric efficiency according to engine speed and flow field data were obtained for different port combinations. The results reveal that swirl and tumble motions are together formed in one side-ported engine simulations. When double-sided-ports are used, tumble motion is prevented by opposing air flow. Results show that double side intake port configuration has highest volumetric efficiency up to 8000 rpm. Single side intake port configuration has high volumetric efficiency up to 3000 rpm and it deteriorates rapidly after 3000 rpm because of high flow frictional losses. For all configurations, it is observed that rotating flows are prevailed by rotor motion at end of compression period and almost similar flow patterns are formed when rotor reaches at top dead center. After obtaining flow field results, combustion of single and double port intake configurations were compared with each other.

Flow-Pattern Details in an Aneurysm Model Using High-Speed 1000-Frames-per-Second Angiography.

Traditional digital subtraction angiography provides rather limited evaluation of contrast flow dynamics when studying and treating intracranial brain aneurysms. A 1000-frames-per-second photon-counting x-ray detector was used to image detailed iodine-contrast flow patterns in an internal carotid artery aneurysm of a 3D-printed vascular phantom. High-speed imaging revealed differences in vortex and inflow patterns with and without a Pipeline Embolization Device flow diverter in more detail and clarity than could be seen in standard pulsed angiography. Improved temporal imaging has the potential to impact the outcomes of endovascular interventions by allowing clinicians to better understand and act on flow dynamics in real-time.

Early Warning Mechanism for the Surge of Passengers in Metro Systems Based on Automated Fare Collection Data: Case Study of Guangzhou, China

Recently, surges of passengers caused by large gatherings, temporary traffic control measures, or other abnormal events have frequently occurred in metro systems. From the standpoint of the operation managers, the available information about these outside events is incomplete or delayed. Unlike regular peaks of commuting, those unforeseen surges pose great challenges to emergency organization and safety management. This study aims to assist managers in monitoring passenger flow in an intelligent manner so as to react promptly. Compared with the high cost of deploying multisensors, the widely adopted automated fare collection (AFC) system provides an economical solution for inflow monitoring from the application point of view. In this paper, a comprehensive framework for the early warning mechanism is established, including four major phases: data acquisition, preprocessing, off-line modeling, and on-line detection. For each station, passengers’ tapping-on records are gathered in real time, to be further transformed into a dynamic time series of inflow volumes. Then, a sequence decomposition model is formulated to highlight the anomaly by removing its inherent disturbances. Furthermore, a novel hybrid anomaly detection method is developed to monitor the variation of passenger flow, in which the features of inflow patterns are fully considered. The proposed method is tested by a numerical experiment, along with a real-world case study of Guangzhou metro. The results show that, for most cases, the response time for detection is within 5 min, which makes the surge phenomenon observable at an early stage and reminds managers to make interventions appropriately.

Hydropower revenues under the threat of climate change in Brazil

Abstract This work analyzes the impacts of climate change in the revenues of hydropower plants. One important input for designing and evaluating investment opportunities in hydropower is the water inflows historical data. Unfortunately, the use of such information alone may not project well the future power generation due to the influence of climate change in the water inflow patterns. This paper introduces spatio-temporal information of the future climate into the operational planning of the Brazilian hydropower system. Global climate models from IPCC are considered along with downscaled regional climate models. Our results at the individual hydro plant level show the importance of taking into account climate change information when performing hydro generation planning studies.

A Twenty‐Year Citation Analysis of the Knowledge Outflow and Inflow Patterns from the Journal of Product Innovation Management

Since its inception in 1984, an emphasis on cross‐functionality and interdisciplinary research was encrypted into the DNA of the Journal of Product and Innovation Management (JPIM). This essay explores the extent to which the journal has served as a platform for exchange of ideas between different disciplines by examining knowledge outflow and inflow with other scientific journals and disciplines over a 20‐year period (1994‐2013). Based on an extensive bibliometric database, we gain insights about how JPIM has evolved. We show that the journal has become a gatekeeper, importing knowledge mostly from the marketing and management literatures, and exporting knowledge to the technology and innovations management and the operations management domains.