Academic literature on the topic 'Trend turning points'

The article analyses the development of Russian retail networks. Special attention is paid to key issues to win position on the local commercial market, where sales entities set up networks of various complexity. Generalizing the experience of performance of main sales networks on the Russian market, the article points out strengthening of the competitive activity and sets up key trends to improve their functioning. There is It gives trend forecast for expansion of sales networks in Russian regions.

The current study illustrated the time variance of turning points in the relationship between carbon emissions and income to resolve heated debate on the different responsibility to climate change with 1950–2010 data of five development diversity countries—three developed countries (Germany, Italy, and Japan) and one developing country (India) and one newly industrialized economy (Taiwan). The article also examines the impact of the crisis on emission. The time-varying patterns in the turning points on environmental Kuznets curves (EKCs) were observed by a rolling regression technique with 1950–2010 data regarding the per capita CO2 emissions caused by fossil fuel combustion and the incomes of the countries. Several empirical findings were revealed from this analysis. Per capita CO2 emissions commonly decreased with varying magnitudes in the five countries over time. The EKC hypothesis regarding the CO2 emissions is affirmed again in this study. The announcement effects associated with the Kyoto Protocol was evidenced. As indicated by the occurring GDP of the turning point, there is a strong reduction trend in the income level of the turning points right before the years of Kyoto Protocol; and this decreasing trend nearly ended as the Kyoto protocol approached its end, except in Germany, where the occurring income of the turning points continued to have a decreasing trend. Although the global financial crisis had its effects in the world, the impacts on carbon dioxide emissions vary across countries.

Turning points are considered to refer to emotional and important events. The present study compared turning point memories to other memories on several ratings and investigated the association between turning points, distress and meaning. Memories may act as organising units in extended narratives, hence the study also tested whether overlap between memories and extended illness narrative was associated with a more coherent narrative. Fifteen patients with breast cancer were asked to tell a 10-minute narrative about their illness course and describe meaning in their illness. Each patient was asked to recall five memories, to state whether or not the memories were turning points, and to rate memories on both event and phenomenological variables. Lastly, the patients were asked to rate distress. The narratives were scored for coherence and the memories were scored for thematic content as well as thematic overlap with the narratives. The results showed that all participants rated the mammography as a turning point and that turning points were rated higher on both event and phenomenological variables. Patients reporting more turning points also reported more distress and not finding meaning in the illness and treatment. High degree of overlap between memories and narratives showed a trend towards an association with a more coherent narrative. The present article discusses processes, which may be involved in the interaction between memories and narratives.

As a base of optimization of metal cutting, a new method of solution of optimization for single pass turning is proposed in this paper. There are three parts for this new method. Firstly, the optimal point must exist on the boundary of the feasible domain of the cutting conditions. Secondly, it is easy to add the processing of determining the boundary of feasible domain as new constraints. Thirdly, the local optimal point on every piece of line or curve of the boundary can be calculated, and finally the minimum of those local optimal points is the final optimal point. There are no local optimal points on the curves of constraints Tmin and Tmax except the intersection points. In addition, the trend of the objective function is affected by the rate . It is helpful to calculate the optimal point by computer. This approach provides a basic research on the affection of the statistics characteristic of the empirical functions used in this case.

The electronic structures of actinide metal doped half sandwich AnB₁₂ (An = Th to Cm) clusters are explored and characterized using relativistic density functional theory. The trend of oxidation state across the actinide series in AnB₁₂ exhibits two turning points, +V in Pa and +II in Am.

The configuration bifurcations of Stewart parallel manipulators at singular positions induce the uncertainty of the moving trends of the manipulative platform. The Jacobian matrix method can determine the singular position of Stewart manipulators, but it cannot determine the configuration variation trend in the vicinity of the singular position. In order to investigate the concrete motion behaviors of the Stewart parallel manipulator at singular positions, we construct the algorithm for determining all the configuration branches and bifurcation points. Through detailed investigations of configuration bifurcation characteristics, we have found that with a decrease of the extensible legs’ length, the bifurcation points of configuration branches of the movable platform get together gradually and the bifurcation type changes from turning to dual-point bifurcation, and then, finally, it becomes multiple-point bifurcation.

The purpose of this study is to develop a method to identify the radical changes in the Mediterranean adequacy index (MAI) trend for monitoring and modifying food and prevention policies. The development of a statistical solver demonstrates that the evolution of the MAI over time (1961-2013) in the EU countries, the USA and Japan is at least bi-parted. In most countries, often two successive conflicting tendencies emerge, whose intersection is signaled by a turning point. The framework of the “knowledge-based view” can help determine whether or not the slopes of the new trend are idiosyncratic with WHO objectives to prevent chronic diseases. Sustainably fighting against the rise in coronary heart disease (CHD) requires to incentive both demand and supply of food products Mediterranean-intensive, revealing by solver use the MAI hidden turning-points . This study allows policymakers to improve their planning, prevention and monitoring capabilities through more exact projections concerning both Mediterranean food markets and emerging CHD risks.

Hard turning has the advantage of rapidly, elasticity and low energy consuming. It has been a trend to replace the complex grinding processes, especially for small batch machining.The surface roughness value of steel after being grinded will ranged in 0.1 to 1.6 μm Ra. This paper points to the precision hard turning of the hardened mold steel, seeking the cutting conditions that can be received in the surface roughness value below 0.1μm Ra, in order to replace the grinding processes. The precision dry turning test were conducted with ceramic cutting tools. The nose radius of the cutting tool was 1.2 mm and the depth of cut was fixed at 0.05 mm. Through a series of turning test, it can be found that, when cutting speed was at 80 to 200 m / min, and feed rate at 0.005 to 0.009 mm / rev, the surface roughness value would be all below 0.1μm Ra. It was superior to grinding process. So we can say that, it is possible to replace the grinding process by hard turning when machining the hardened mold steel.

Die Länge der Vegetationsperiode (VP) spielt eine zentrale Rolle für die interannuelle Variation der Kohlenstoffspeicherung terrestrischer Ökosysteme. Die Analyse von Beobachtungsdaten hat gezeigt, dass sich die VP in den letzten Jahrzehnten in den nördlichen Breiten verlängert hat. Dieses Phänomen wurde oft im Zusammenhang mit der globalen Erwärmung diskutiert, da die Phänologie von der Temperatur beeinflusst wird.

Die Analyse der Pflanzenphänologie in Süddeutschland im 20. Jahrhundert zeigte:
- Die starke Verfrühung der Frühjahrsphasen in dem Jahrzehnt vor 1999 war kein singuläres Ereignis im 20. Jahrhundert. Schon in früheren Dekaden gab es ähnliche Trends. Es konnten Perioden mit unterschiedlichem Trendverhalten identifiziert werden.
- Es gab deutliche Unterschiede in den Trends von frühen und späten Frühjahrsphasen. Die frühen Frühjahrsphasen haben sich stetig verfrüht, mit deutlicher Verfrühung zwischen 1931 und 1948, moderater Verfrühung zwischen 1948 und 1984 und starker Verfrühung zwischen 1984 und 1999. Die späten Frühjahrsphasen hingegen, wechselten ihr Trendverhalten in diesen Perioden von einer Verfrühung zu einer deutlichen Verspätung wieder zu einer starken Verfrühung.

Dieser Unterschied in der Trendentwicklung zwischen frühen und späten Frühjahrsphasen konnte auch für ganz Deutschland in den Perioden 1951 bis 1984 und 1984 bis 1999 beobachtet werden.
Der bestimmende Einfluss der Temperatur auf die Frühjahrsphasen und ihr modifizierender Einfluss auf die Herbstphasen konnte bestätigt werden. Es zeigt sich jedoch, dass
- die Phänologie bestimmende Funktionen der Temperatur nicht mit einem globalen jährlichen CO2 Signal korreliert waren, welches als Index für die globale Erwärmung verwendet wurde
- ein Index für grossräumige regionale Zirkulationsmuster (NAO-Index) nur zu einem kleinen Teil die beobachtete phänologischen Variabilität erklären konnte.

Das beobachtete unterschiedliche Trendverhalten zwischen frühen und späten Frühjahrsphasen konnte auf die unterschiedliche Entwicklung von März- und Apriltemperaturen zurückgeführt werden. Während sich die Märztemperaturen im Laufe des 20. Jahrhunderts mit einer zunehmenden Variabilität in den letzten 50 Jahren stetig erhöht haben, haben sich die Apriltemperaturen zwischen dem Ende der 1940er und Mitte der 1980er merklich abgekühlt und dann wieder deutlich erwärmt.
Es wurde geschlussfolgert, dass die Verfrühungen in der Frühjahrsphänologie in den letzten Dekaden Teile multi-dekadischer Fluktuationen sind, welche sich nach Spezies und relevanter saisonaler Temperatur unterscheiden. Aufgrund dieser Fluktuationen konnte kein Zusammenhang mit einem globalen Erwärmungsignal gefunden werden.
Im Durchschnitt haben sich alle betrachteten Frühjahrsphasen zwischen 1951 und 1999 in Naturräumen in Deutschland zwischen 5 und 20 Tagen verfrüht. Ein starker Unterschied in der Verfrühung zwischen frühen und späten Frühjahrsphasen liegt an deren erwähntem unterschiedlichen Verhalten. Die Blattverfärbung hat sich zwischen 1951 und 1999 für alle Spezies verspätet, aber nach 1984 im Durchschnitt verfrüht. Die VP hat sich in Deutschland zwischen 1951 und 1999 um ca. 10 Tage verlängert.
Es ist hauptsächlich die Änderung in den Frühjahrphasen, die zu einer Änderung in der potentiell absorbierten Strahlung (PAS) führt. Darüber hinaus sind es die späten Frühjahrsphasen, die pro Tag Verfrühung stärker profitieren, da die zusätzlichen Tage länger undwärmer sind als dies für die frühen Phasen der Fall ist. Um die relative Änderung in PAS im Vergleich der Spezies abzuschätzen, müssen allerdings auch die Veränderungen in den Herbstphasen berücksichtigt werden.
Der deutliche Unterschied zwischen frühen und späten Frühjahrsphasen konnte durch die Anwendung einer neuen Methode zur Konstruktion von Zeitreihen herausgearbeitet werden. Der neue methodische Ansatz erlaubte die Ableitung verlässlicher 100-jähriger Zeitreihen und die Konstruktion von lokalen kombinierten Zeitreihen, welche die Datenverfügbarkeit für die Modellentwicklung erhöhten.
Ausser analysierten Protokollierungsfehlern wurden mikroklimatische, genetische und Beobachtereinflüsse als Quellen von Unsicherheit in phänologischen Daten identifiziert. Phänologischen Beobachtungen eines Ortes können schätzungsweise 24 Tage um das parametrische Mittel schwanken.Dies unterstützt die 30-Tage Regel für die Detektion von Ausreissern.
Neue Phänologiemodelle, die den Blattaustrieb aus täglichen Temperaturreihen simulieren, wurden entwickelt. Diese Modelle basieren auf einfachen Interaktionen zwischen aktivierenden und hemmenden Substanzen, welche die Entwicklungsstadien einer Pflanze bestimmen. Im Allgemeinen konnten die neuen Modelle die Beobachtungsdaten besser simulieren als die klassischen Modelle.

Weitere Hauptresultate waren:
- Der Bias der klassischen Modelle, d.h. Überschätzung von frühen und Unterschätzung von späten Beobachtungen, konnte reduziert, aber nicht vollständig eliminiert werden.
- Die besten Modellvarianten für verschiedene Spezies wiesen darauf hin, dass für die späten Frühjahrsphasen die Tageslänge eine wichtigere Rolle spielt als für die frühen Phasen.
- Die Vernalisation spielte gegenüber den Temperaturen kurz vor dem Blattaustrieb nur eine untergeordnete Rolle.
The length of the vegetation period (VP) plays a central role for the interannual variation of carbon fixation of terrestrial ecosystems. Observational data analysis has indicated that the length of the VP has increased in the last decades in the northern latitudes mainly due to an advancement of bud burst (BB). This phenomenon has been widely discussed in the context of Global Warming because phenology is correlated to temperatures.

Analyzing the patterns of spring phenology over the last century in Southern Germany provided two main findings:
- The strong advancement of spring phases especially in the decade before 1999 is not a singular event in the course of the 20th century. Similar trends were also observed in earlier decades. Distinct periods of varying trend behavior for important spring phases could be distinguished.
- Marked differences in trend behavior between the early and late spring phases were detected. Early spring phases changed as regards the magnitude of their negative trends from strong negative trends between 1931 and 1948 to moderate negative trends between 1948 and 1984 and back to strong negative trends between 1984 and 1999. Late spring phases showed a different behavior. Negative trends between 1931 and 1948 are followed by marked positive trends between 1948 and 1984 and then strong negative trends between 1984 and 1999.
This marked difference in trend development between early and late spring phases was also found all over Germany for the two periods 1951 to 1984 and 1984 to 1999.

The dominating influence of temperature on spring phenology and its modifying effect on autumn phenology was confirmed in this thesis. However,
- temperature functions determining spring phenology were not significantly correlated with a global annual CO2 signal which was taken as a proxy for a Global Warming pattern.
- an index for large scale regional circulation patterns (NAO index) could only to a small part explain the observed phenological variability in spring.

The observed different trend behavior of early and late spring phases is explained by the differing behavior of mean March and April temperatures. Mean March temperatures have increased on average over the 20th century accompanied by an increasing variation in the last 50 years. April temperatures, however, decreased between the end of the 1940s and the mid-1980s, followed by a marked warming after the mid-1980s.
It can be concluded that the advancement of spring phenology in recent decades are part of multi-decadal fluctuations over the 20th century that vary with the species and the relevant seasonal temperatures. Because of these fluctuations a correlation with an observed Global Warming signal could not be found.
On average all investigated spring phases advanced between 5 and 20 days between 1951 and 1999 for all Natural Regions in Germany. A marked difference be! tween late and early spring phases is due to the above mentioned differing behavior before and after the mid-1980s. Leaf coloring (LC) was delayed between 1951 and 1984 for all tree species. However, after 1984 LC was advanced. Length of the VP increased between 1951 and 1999 for all considered tree species by an average of ten days throughout Germany.
It is predominately the change in spring phases which contributes to a change in the potentially absorbed radiation. Additionally, it is the late spring species that are relatively more favored by an advanced BB because they can additionally exploit longer days and higher temperatures per day advancement. To assess the relative change in potentially absorbed radiation among species, changes in both spring and autumn phenology have to be considered as well as where these changes are located in the year.
For the detection of the marked difference between early and late spring phenology a new time series construction method was developed. This method allowed the derivation of reliable time series that spanned over 100 years and the construction of locally combined time series increasing the available data for model development.
Apart from analyzed protocolling errors, microclimatic site influences, genetic variation and the observers were identified as sources of uncertainty of phenological observational data. It was concluded that 99% of all phenological observations at a certain site will vary within approximately 24 days around the parametric mean. This supports to the proposed 30-day rule to detect outliers.
New phenology models that predict local BB from daily temperature time series were developed. These models were based on simple interactions between inhibitory and promotory agents that are assumed to control the developmental status of a plant. Apart from the fact that, in general, the new models fitted and predicted the observations better than classical models, the main modeling results were:
- The bias of the classical models, i.e. overestimation of early observations and underestimation of late observations, could be reduced but not completely removed.
- The different favored model structures for each species indicated that for the late spring phases photoperiod played a more dominant role than for early spring phases.
- Chilling only plays a subordinate role for spring BB compared to temperatures directly preceding BB.

AbstractThe many faces of the European Council make it a core component of the institutional machinery maintaining relations between the EU and third countries, including Turkey. This chapter identifies the European Council’s roles as the EU’s ‘master of enlargement’, ‘external voice and crisis manager’, and ‘agenda and direction setter’ as its three primary functions that drive the EU–Turkey relationship. The central focus of the chapter is the evolution of the European Council in framing relations with a candidate country—or what many now call a ‘strategic partner’—and the identification of the critical turning points and shifts in the central functions, internal dynamics, and preferences of this key institution. The findings indicate a growing trend toward a more conflictual, relatively hostile relationship between the European Council and Turkey as a result of diverging geopolitical interests—especially in the Eastern Mediterranean—and normative considerations. Furthermore, the analysis reveals an expanding impact of bilateral issues and member states’ individual preferences on the European Council’s role as a driver of EU–Turkey relations. Still, with their powers, the Heads of State or Government are likely to remain a key driver of the future trajectory of the relationship, demonstrating an increased interest in ‘thinking outside of the accession box’ and in framing a relationship model that would safeguard EU–Turkey relations amidst growing disagreements with Ankara.

AbstractThe New York metropolitan area is one of the oldest, largest, and perhaps most complex urban region in the United States (U.S.). Its 23.7 million residents live across four states, produce a GDP of more than $1.7 trillion, are governed by a fragmented political system, and experience persistently high degrees of geographic and racial/ethnic inequality and segregation. This chapter investigates the evolving spatial organization of occupation and race across the metropolitan area. While white professionals have traditionally lived in an outer ring of suburbs and blue-collar immigrant and minority groups have lived closer to the city center, our research shows that the forces of gentrification and minority and immigrant suburbanization have been turning the metropolitan area inside out. Specifically, young, usually white, professionals are increasingly located in and around the central city whereas many working-class minorities have shifted away from it. At the heart of this spatial reordering lie the diminishing plurality of native-born whites within the region and the increasing share of immigrant minority groups, especially for foreign-born Hispanics and Asians. This trend has lessened the share of white males in better occupations even as the region’s occupational structure slowly but inexorably tilts toward managerial and professional occupations. Technology is transforming white-collar work as blue-collar work continues to disappear. Dramatic shifts are thus afoot, yet inequality and segregation remain high. We argue that these changes in the spatial organization of the metropolitan area challenge us to see these inequalities from a new vantage point. As elites are now more likely to live among less advantaged groups, this may provide the social basis for new thinking.

The precise generic beginnings of horror cinema have the odd status of being both simultaneously clear and opaque. The general trend in studies of horror cinema has been to date the genre’s beginnings around the release of the series of Universal’s ‘monster movies’ beginning with Frankenstein (James Whale, 1931) and Dracula (Tod Browning, 1931). The desire to search for the antecedents, roots and origins of any genre leads film scholars to identify certain texts as key turning points that effectively lay the ground for what follows. While this view of genre can be overly deterministic, it is nonetheless true that some texts rather than others are given the status of key reference points based upon their perceived historical importance.

There is a growing trend in education that has considerable potential for fostering constructive, unselfish behavior during adolescence: community service. Supervised community service, when started in early adolescence, can play a critical role in the shaping of responsible, caring, altruistic behavior. Service programs can be organized effectively by schools, by community organizations, and by religious institutions. How we help others is crucial. We must not convey superiority over others. We must impart a sense of the mutuality of being full members of the community and sharing a common fate as human beings in a world that sometimes is insensitive and at times even cruel. In 1989, a Carnegie report on the middle grades, Turning Points, stated an important insight. Early adolescence offers a superb developmental opportunity to learn values, skills, and a sense of social responsibility important for citizenship in democracies. Every middle grade school should include youth service—supervised activity helping others in the community, ideally, in collaboration with schools—in their core instructional programs for the middle grades. Turning Points 2000, a follow-up book to the 1989 landmark report, Turning Points, provides an in-depth examination of how to improve education for the middle grades and gives practical guidance to practitioners wishing to implement the Turning Points model. The research base has grown over the past 10 years, and this chapter reflects the findings of the research. It also bridges the gap between research and practice by presenting theory in practical and understandable terms. Specific to our theme of service learning, Turning Points 2000 provides a sound argument for integrating the community into the curriculum. Mutual respect and understanding, a sense of belonging, and pride in making valued contributions to others are the essence of school and community collaboration. The Early Adolescent Helper Program (EAHP), a pioneering project initiated by the City University of New York in 1982 and led by Joan Schine, brings school personnel, community-agency staff, and the middle grade school Helpers together. An effort was clearly made to integrate the school curricula with youth in community service programs. Between 1982 and 1989, almost 700 students in 17 New York City middle and junior high schools were involved in the Early Adolescent Helper Program.

Government consumption plays an important role for stability of the national economy, especially in periods of economic crisis. However, rapidly growing public debt is a concerning issue nowadays, since it might jeopardize economic growth perspectives. Economic theory suggests that public debt has non-linear impact on economic growth in a form of inverted U-shape. In other words, it is believed that after a certain threshold, public debt will have negative impact on economic growth. Given that such threshold varies significantly across countries, the aim of this paper is to calculate the turning point of the public debt impact in the Republic of North Macedonia. For this purpose, we use non-linear multiple regression model for real GDP growth rate as dependent variable, general government public debt-to-GDP ratio (in nominal and squared terms) as key independent variable, as well as several other controlling variables. Since theory also suggests reverse causality between economic growth and public debt, we use three different estimation techniques (Ordinary Least Squares, Two-Stages Least Squares, and Generalized Method of Moments) to deal with potential endogeneity, as well as to cross-validate the results. Our results show that general government debt in the Republic of North Macedonia positively affects economic growth until it reaches around 30% of GDP, whereas further indebtedness after that turning point will most likely have negative impact. Given that current debt level is slightly above 40% (10 percentage points higher than the turning point), whereby due to the COVID-19 crisis it is expected to grow even more in the upcoming years, the need of urgent fiscal consolidation inevitably arises. In this regards, deeper and more comprehensive analysis is needed in order to identify adequate channels for its efficient and effective implementation.

Understanding the effects of tool wear is critical to predicting tool life, the point at which tool performance, in terms of power requirement, dimensional error, surface finish, or chatter, is no longer acceptable. To achieve the long cuts that are required for wear testing while maintaining a clear view of the basic process geometry effects, ideal straight-edged orthogonal conditions are realized in a bar-turning arrangement by employing a specially designed two-tool setup. The data show that increasing edge radius tends to increase wear rate, especially at the initial cut-in wear phase. The data also show that when the uncut chip thickness is less than or equal to the edge radius, forces actually decrease substantially with flank wear until most of the edge radius has been worn away. At that point the forces begin to increase with flank wear in a power-law fashion. This decreasing-then-increasing trend is a result of the parasitic (non chip removing) wear-land force increasing more slowly than the chip-removal force is decreasing. The decrease in chip-removal force with an increase in flank wear results from the blunt edge being effectively sharpened as it is removed by the growing wear land. An empirical model structure is formulated, guided by specific elements of the data, to well represent the force trends with respect to wear and edge radius and to assist in their interpretation. The edge-sharpening concept is further supported by a special experiment in which the edge is sharpened without the presence of the wear land.

End wall contouring has been widely studied during past two decades for secondary loss reduction in turbine passages. Recent non-axisymmetric end wall contouring methods have shown more promise for loss reduction as compared to the axisymmetric end wall contouring methods used in initial studies. The end wall contouring methods have shown definite promise, especially, for the turbine passages at low design exit Mach numbers. A class of methods exists in the literature where the end wall surface is defined by using a combination of two curves. These curves specify surface topology variation in streamwise and pitchwise directions. Another class of methods depends on surface contour optimization, in which the modification of surface contours is achieved by changing the control point locations that define the surface topology. A definitive, passage design parameter based method of contouring is still not available. However, a general guideline for the trend of contour variation, along pitchwise and streamwise direction, can certainly be extrapolated from the existing literature. It is not clear, however, whether such a trend can be fitted to any blade profile to achieve, least of all a nonoptimum but a definite, reduction in losses. Moreover, almost all of the existing studies have focused on end wall contouring of passages with low exit Mach numbers. Some researchers, indeed, have used blades designed for high turning and high exit Mach number. However, such studies were done at Mach number well below the intended design condition. A study of effect of end wall contouring on a high turning blade with high design exit Mach number is not available in open literature. The present study investigates the effect of application of three different types of end wall contouring methods through numerical simulation, on a high turning transonic turbine blade passage. The main contouring method is based on total loss reduction criterion which is described here in detail. The contouring methodology described here avoids the deficiency of current commercial mesh generation software in context of automated meshing and provides a robust end wall optimization methodology. The geometry that gives minimum SKE values is compared with this loss optimized geometry. Additionally, a normalized contoured surface topology was extracted from a previous study that has similar blade design parameters and this surface was fitted to the turbine passage under study in order to investigate the effect of such trend based surface fitting. This contour geometry has also been compared with the other two contour geometries. Aerodynamic response of these geometries has been compared in detail with the baseline case without any end wall contouring. A comparison of shape and location of end wall contours on aerodynamic performance has been provided. The results indicate that end wall contouring for transonic turbine blades may not result in as significant gains at design conditions as those claimed for low speed turbine passages in previous studies.

This paper presents a single point optimization of the LS89 turbine vane cascade for a downstream isentropic Mach number of 0.9. The objective of the optimization is to minimize the entropy generation through the cascade while maintaining the flow turning of the baseline geometry. The optimization is performed using a hybrid optimization algorithm which combines two main families of optimization methods, namely an evolutionary algorithm and a gradient-based method. The combination of these two methods aims to correct their respective main disadvantage which are the poor convergence performance of the evolutionary and the trend to get trapped in local minima of the gradient-based method. The hybrid algorithm implemented in this work is based on the Lamarckian evolution and consists in incorporating directly the gradient-based method inside the loop of the evolutionary algorithm. In this approach, the evolutionary algorithm performs a global exploration of the design space while the gradient-based method improves the convergence rate of the evolutionary algorithm. The better performance of the developed hybrid method, compared to a classical evolutionary algorithm, is first demonstrated on two analitycal functions used as benchmark problems. Subsequently, the hybrid algorithm is used to optimize LS89 turbine vane, resulting in a new design with about 20 percent lower entropy production compared to baseline geometry. A thorough flow analysis shows that the improvements are largely due to a significant decrease in trailing edge losses, which is characterized by a higher base pressure. A previous optimization of the LS89 cascade has been already realized using a classical gradient-based method. This optimization converged towards a new design which reduces the entropy rise by a factor of 11 percent. Therefore, the comparison between this optimum and the one found using the proposed method demonstrates that the hybrid algorithm allows to locate a better minimum by performing a global exploration of the design space.

One of the main approaches to sustainable urbanization strategy is to find appropriate resources for promoting the quality of life via developing infrastructure and extending facilities and support urban life by facilitating public access to meet their needs. Based on that we can approach a new urban economy based on sustainable resources and a specific diagram and discipline will participate in it. To realize this idea a clear statement and belief are needed. We expect that the outcome may be under undue pressure of the global political and economic forces because the new model is looking for creating fundamental changes to the current trends and turning to the new paradigm and world development system. To reach this level of transformation this article will focus on 3 cities with different scales, knowing that the scale plays an important role in municipal finance, so: 1- This article will review the top alternative models of the current urban economy. 2- It will examine and analyze the interaction between understandings, recognizing the main challenges of important points between the concepts of life at a macro perspective; the current state of economic circulation in cities and expressing clear key points. 3- This article will be based on the city Prosperity Index of United Nations and also on indexes of the quality of life in order to introduce a model of sustainable urban lifestyle, which will be introduced as a ‘dream’. As planners, we need to help cities promote self-reliance by redesigning the city in such a way that there will be a balance between external dependency and self-reliance 4- It will provide some examples of top priorities on sustainable resources to achieve the goals.

One of the main design decisions in the development of low-speed axial fans is the right choice of the blade loading versus rotational speed, since a target pressure rise could either be achieved with a slow spinning fan and high blade loading or a fast spinning fan with less flow turning in the blade passages. Both the blade loading and the fan speed have an influence on the fan performance and the fan acoustics and there is a need to find the optimum choice in order to maximize efficiency while minimizing noise emissions. The present paper addresses this problem by investigating five different fans with the same pressure rise but different rotational speeds in the design point. In the first part of the numerical study, the fan design is described and steady-state Reynolds-averaged Navier-Stokes (RANS) simulations are conducted in order to identify the performance of the fans in the design point and in off-design conditions. The investigations show the existence of an optimum in rotational speed regarding fan efficiency and identify a flow separation on the hub causing a deflection of the outflow in radial direction as the main loss source for slow spinning fans with high blade loadings. Subsequently, Large Eddy Simulations (LES) along with the acoustic analogy of Ffowcs Williams and Hawkings (FW-H) are performed in the design point to identify the main noise sources and to determine the far-field acoustics. The identification of the noise sources within the fans in the near-field is performed with the help of the power spectral density of the pressure. In the far-field, the sound power level is computed using different parts of the fan surface as FW-H sources. Both methods show the same trends regarding noise emissions and allow for a localization of the noise sources. The flow separation on the hub is one of the main noise sources along with the tip vortex with an increase in its strength towards lower rotational speeds and higher loading. Furthermore, a horseshoe vortex detaching from the rotor leading edge and impinging on the pressure side as well as the turbulent boundary layer on the suction side represent significant noise sources. In the present investigation, the maximum in efficiency coincides with the minimum in noise emissions.

This paper presents both experimental and numerical results demonstrating the dramatic effect of a particular geometric discontinuity on the flow within a highly-loaded single-stage transonic compressor. This compressor features cantilevered variable-stagger stator vanes (VSV) with buttons at the outer radius partially standing out in the annulus, by a value of about 0.3 mm which amounts to 0.5% of vane height. The first tests of this compressor revealed a very large corner flow separation at the stator outer radius. This feature could not be reproduced by steady 3D Navier-Stokes computations of the stator flow field with a smooth flowpath. However, using a simple numerical approach to account for the actual geometric discontinuity of the annulus, the computation then showed flow trends similar to that of the experiment. Also, a detailed analysis of the computed flow field indicated that the flow turning (both radial and tangential) due to the button blockage contributed toward strengthening the effect of secondary flows. Subsequently, after the button geometry was corrected to match the flowpath, further tests confirmed a much more satisfactory flow behaviour within the stator vanes leading to a one point improvement in compressor isentropic efficiency. This study leads to the conclusion that ensuring a smooth flowpath can be critically important for the high stage leadings characteristic of advanced military applications. Moreover, the predictive value of 3D Navier-Stokes computations for the simulation of technological effects, such as VSV buttons / flowpath mismatch, is clearly demonstrated.