Academic literature on the topic 'Opening times'

AbstractImages of mind marks a new era in human cognitive neuroscience. Despite the difficult conceptual problems associated with using group-averaged data and paired subtractions, human PET images converge well with existing data from other areas of cognitive neuroscience while opening up new theoretical and experimental possibilities. However, greater attention to individual differences might prove necessary in the study of culturally driven adaptations such as literacy.

This paper employs cointegration tests to identify the impacts of sequential opens of global equity market among the equity indices. We use the daily data of 31 major equity markets and explore the comovement relationship according to the sequence of the market open. This study also examines the impact of the 2008 global financial crisis to such comovement relationship. Our results indicate that the markets in Europe-Middle East, Asia-Pacific and Latin America, are less affected by the levels of earlier opens of other markets. After the end of 2007, the global equity market comovement pattern changed significantly, yet the interdependence of markets was not unanimously strengthened. The size of an equity market does not dictate its range and power of impact, as we find that a large size market can still be cointegrated with small size markets, while a small size market is almost always cointegrated with large size markets.

People vary in their preferred times of day for activity. Notably, as individuals age, their daily energy and attention typically peaks earlier in the day. When voting is permitted may then affect voters’ age distribution, even when holding constant the number of hours polls are open. Data from along the time-zone border in Kentucky, where poll-availability hours vary, supports this hypothesis: places where voting hours are later see higher turnout rates among younger voters and lower turnout rates among older voters. The one-hour delay in voting hours reduces older registrants’ turnout, and boosts younger registrants’, by roughly three percentage points.

The paper describes a method to measure injector opening and closing lag times based on measuring the vibration in the axis of movement of a valve. There are also some results of the studies on a plate injector. Analysing the measurements obtained, it is demonstrated that opening and closing lag times can be determined much more precisely by measuring vibration than by the method based on analysing gas pressure directly behind an injector. The authors have noted the greater repeatability of standard deviation expressed as the smaller standard deviation of the lag times specified and the easy application of this method for stand testing. Consequently, this method can determine these times in a simple and precise way.

Recent experiments have shown that after osmotic opening the blood-brain barrier recloses more rapidly to larger than to smaller molecules. Quantitative theoretical analysis of blood-brain barrier permeability to different-sized molecules at different times after osmotic opening supports the concept of pore creation as a result of opening of tight junctions between endothelial cells. Experiments also suggest significant bulk water flow from capillaries into brain within 10 min after opening at an average rate of approximately 1.6 X 10(-4) cm3 X s-1 X g brain-1. A mathematical model of blood-brain barrier permeability based on the creation of pores, together with bulk fluid flow, is presented for both cylindrical pores and rectangular slits. Experimental data are compatible with pore radii of approximately 200 A or slit widths of approximately 220 A. Pore densities of approximately 1 pore per 200 microns 2 of membrane surface are calculated at 6 min after barrier opening, reducing slightly as the barrier recloses. Calculated bulk flow is reduced by an order of magnitude within 35 min of barrier opening and is a major factor in altered blood-brain barrier permeability. Size dependence of blood-brain barrier permeability following osmotic opening is shown to be incompatible with enhanced vesicular transport.

This study aims i) to determine the effect of Dundubia manifera insect sound on the stomata opening area of corn plant (Zea Mays L.) at frequencies of (in Hz) 3000, 3500, 4000, 4500, and 5000, and ii) to know the peak frequency that can optimize the stomata opening of the corn plant. The insect sound has been manipulated into peak frequencies and validated using Octave 4.2.1 software. The experiment uses one corn-field for the treatment and control plants. Sampling is taken three times, i.e.: 15 minutes before sound exposure, during sound exposure for 30 minutes, and 15 minutes after sound exposure. The stomata opening area is observed using a microscope by observing the output via NIS Elements Viewer program. The length and width of the stomata openings are measured using Image Raster 3.0 and the area of the stomata opening is calculated using the elliptic equation. This study shows that the stomata opening area when given sound exposure is larger than without sound exposure. The largest stomata opening area is obtained at a frequency of 3000 Hz, viz.: 93.7 µm².

1. We recorded rise times and amplitudes of spontaneous GABAergic inhibitory postsynaptic currents (IPSCs) in melanotropes of Xenopus laevis. Average rise times did not vary with amplitude, but the rise times of larger IPSCs were less variable. A simple linear one-step Markov model for channel opening following the binding of a transmitter molecule can quantitatively account for the average rise time and its coefficient of variation as a function of amplitude. Our results indicate that the observed variations in the rise times are not due to variations in transmitter concentrations, but result from stochastic variations in the opening of the receptor channels.

We examined the effects of group selection with legacy-tree retention on ground-layer or understory diversity and composition in an uneven-aged northern hardwood forest in the Upper Peninsula of Michigan. We sampled 20 reference plots in the surrounding forest matrix and 49 openings with radii of 0.5 (n = 16), 0.75 (n = 17), and 1.0 (n = 16) times mean canopy tree height (22 m). Resultant opening areas were 321 ± 16 (mean ± SEs), 697 ± 21, and 1256 ± 39 m2, respectively. Each opening contained a centrally located legacy tree. Two years after harvesting, ground-layer diversity was significantly higher in openings than on reference plots (p < 0.05) because of an influx of early seral, wetland, and weedy exotic species. The importance of aggressive ruderals (i.e., Carex ormostachya Wieg. and Rubus idaeus subsp. strigosus (Michx.) Focke) increased significantly (p < 0.001) with increasing opening area. Although the importance and cover of several late-seral species were lower in openings compared with the forest matrix, few species found in the matrix were wholly absent from the openings. These results suggest that ground-layer plant communities in managed northern hardwood forests may display a high degree of resilience to intermediate-intensity disturbances.

Für vom Prüfungsstress geplagte Studierende ist dies in Dresden bereits seit fünf Jahren ein unverzichtbarer Service. Seit dem Wintersemester 2003 öffnet die SLUB für ihre Leser, zu denen nicht nur Studierende, sondern auch interessierte Dresdner Bürger und Gäste der Stadt zählen, an sechs bis acht Sonntagen in der Prüfungsphase der Universität ihre Türen. Was seinerzeit noch als Seltenheit galt – nicht nur in Sachsen war die SLUB Dresden mit diesem Angebot Vorreiterin – hat längst viele Nachahmer gefunden und gehört heute an deutschen Universitäten und Hochschulen zunehmend zum Standard.

Mining is one of the oldest activities of humanity, as the extraction of stones, ceramics and metals proved to be essential to develop tools and weapons and to drive forward human civilisation. Possibly the oldest mine – the “Lion Cave” – dates back to 41 000 BC. Located in Swaziland, its pre-historic operators mined haematite to make red-pigment ochre. The mine was likely in operation until 23 000 BC and at least 1200 tons of soft haematite had been removed in this timespan. As time progressed, mining diversified and production methods improved. The ancient Egyptians, Greeks and Romans mined different minerals, such as malachite, copper and gold. Philipp II, the father of Alexander the Great, is believed of having conquered gold mines in Thrace, which provided him with 1000 talents (26 tons) of gold per year. Needless to say that Alexander’s conquests would have not been possible without these extensive mining operations. Over the ages, mining activities continued to intensify. Today, a tier-one open-pit copper mine like Chuquicamata in Chuquicamata, Chile, with a depth of 900 m, provides for a production of 443,000 tons of copper and 20,000 tons of molybdenum p.a. Naturally such levels of production come with a price tag. Thousands of workers, numerous heavy machines and investments that go into the millions and billions are required to set up a mine and to maintain its operation. At the same time large amounts of waste – the so-called tailings – are generated, often posing a significant environmental risk. The fact that ore yields have dramatically decreased over time has worsened the situation; today, the extraction of 1 ton of metal ore requires vast amounts of energy and can easily generate hundreds of tons of waste.iv Were it not for a significant technological progress in the extraction, transport and processing of the ores, today’s mining operations could not be sustained. Despite all these technological advances, the mining industry is at a decision point. The conventional trend of the last hundred years of counteracting shrinking ore yields by making the mining machinery faster and bigger is at its limits. Today’s ore haulers weigh as much as 600 tons and require a net engine power of 2722 kW v to sustain operation. At the same time waste heaps have grown larger and larger – operations are clearly at their physical limits. Time is running out for enhancements and improvements, if mining is to continue, a drastic paradigm shift seems to be the only solution. This paradigm shift will require humanity to mine more efficiently and intelligently, by aiming to extract only these rocks that contain the ore and doing so in a manner, which results in the smallest possible ecological footprint. This is where OffWorld’s Swarm Robotic Mining Architecture comes into play. The overarching purpose of OffWorld is to enable the human settlement of space by developing a new generation of small, smart, learning industrial robots. This robotic workforce has numerous things to do: build landing pads, excavate underground habitats, extract water ice and materials, make drinkable water, breathable air and rocket propellant, manufacture basic structures and solar cells, produce electricity, etc. OffWorld’s overall vision is to operate thousands of robots that can mine, manufacture and build on the Moon, the as-teroids and Mars. These robots need to be small and robust, extremely adaptable, modular and reconfigurable, autonomous and fast learning – they are lightyears ahead of the 2 million industrial robots that currently work in factories and warehouses. Space is a tough place. The environment is harsh, resources are limited and the room for errors is close to zero. If a robot can succeed in space than it can surely excel in the terrestrial industry as well. This and the fact that OffWorld builds a swarm approach that relies on a small form factor, intelligence and surgical precision, has the potential to reduce the total cost of operations, can shorten the life of mine or industrial operation and can be easily scaled up and down in size. With all these benefits in mind, OffWorld is looking into a reduction in the total cost of operations of at least an order of magnitude within any industrial sector. This paper will introduce the design philosophy behind OffWorld’s robotic work-force and will present the masterplan for developing space-bound systems by first maturing them in large scale deployments in terrestrial industries.

In modern day communication systems, there is a constant demand for increase in transmission rates. This is however limited by the bandwidth limitation of the channel. Inter symbol interference (ISI) imposes a great threat to increasing data rates by degrading the signal quality. Equalizers are used at the receiver to compensate for the losses in the channel and thereby greatly mitigate ISI. Further, an adaptive equalizer is desired which can be used over a channel whose response is unknown or is time-varying. A low power equalizing solution in a moderately attenuated channel is an analog peaking filter which boosts the signal high frequency components. Such conventional continuous time linear equalizers (CTLE) provide a single degree of controllability over the high frequency boost. A more complex CTLE has been designed which has two degrees of freedom by controlling the high frequency boost as well as the range of frequencies over which the boost is applied. This extra degree of controllability over the equalizer response is desired to better adapt to the varying channel response and result in an equalized signal with a wider eye opening. A robust adaptation technique is necessary to tune the equalizer characteristics. Some of the commonly used techniques for adaptation of CTLEs are based on energy comparison criterion in the frequency domain. But the adaptation achieved using these techniques might not be optimal especially for an equalizer with two degrees of controllability. In such cases an eye opening monitor (EOM) could be used which evaluates the actual signal quality in time domain. The EOM gives an estimate on the signal quality by measuring the eye opening of the equalized signal in horizontal and vertical domain. In this thesis work a CTLE with two degrees of freedom with an EOM based adaptation system has been implemented.

Mining is one of the oldest activities of humanity, as the extraction of stones, ceramics and metals proved to be essential to develop tools and weapons and to drive forward human civilisation. Possibly the oldest mine – the “Lion Cave” – dates back to 41 000 BC. Located in Swaziland, its pre-historic operators mined haematite to make red-pigment ochre. The mine was likely in operation until 23 000 BC and at least 1200 tons of soft haematite had been removed in this timespan. As time progressed, mining diversified and production methods improved. The ancient Egyptians, Greeks and Romans mined different minerals, such as malachite, copper and gold. Philipp II, the father of Alexander the Great, is believed of having conquered gold mines in Thrace, which provided him with 1000 talents (26 tons) of gold per year. Needless to say that Alexander’s conquests would have not been possible without these extensive mining operations. Over the ages, mining activities continued to intensify. Today, a tier-one open-pit copper mine like Chuquicamata in Chuquicamata, Chile, with a depth of 900 m, provides for a production of 443,000 tons of copper and 20,000 tons of molybdenum p.a. Naturally such levels of production come with a price tag. Thousands of workers, numerous heavy machines and investments that go into the millions and billions are required to set up a mine and to maintain its operation. At the same time large amounts of waste – the so-called tailings – are generated, often posing a significant environmental risk. The fact that ore yields have dramatically decreased over time has worsened the situation; today, the extraction of 1 ton of metal ore requires vast amounts of energy and can easily generate hundreds of tons of waste.iv Were it not for a significant technological progress in the extraction, transport and processing of the ores, today’s mining operations could not be sustained. Despite all these technological advances, the mining industry is at a decision point. The conventional trend of the last hundred years of counteracting shrinking ore yields by making the mining machinery faster and bigger is at its limits. Today’s ore haulers weigh as much as 600 tons and require a net engine power of 2722 kW v to sustain operation. At the same time waste heaps have grown larger and larger – operations are clearly at their physical limits. Time is running out for enhancements and improvements, if mining is to continue, a drastic paradigm shift seems to be the only solution. This paradigm shift will require humanity to mine more efficiently and intelligently, by aiming to extract only these rocks that contain the ore and doing so in a manner, which results in the smallest possible ecological footprint. This is where OffWorld’s Swarm Robotic Mining Architecture comes into play. The overarching purpose of OffWorld is to enable the human settlement of space by developing a new generation of small, smart, learning industrial robots. This robotic workforce has numerous things to do: build landing pads, excavate underground habitats, extract water ice and materials, make drinkable water, breathable air and rocket propellant, manufacture basic structures and solar cells, produce electricity, etc. OffWorld’s overall vision is to operate thousands of robots that can mine, manufacture and build on the Moon, the as-teroids and Mars. These robots need to be small and robust, extremely adaptable, modular and reconfigurable, autonomous and fast learning – they are lightyears ahead of the 2 million industrial robots that currently work in factories and warehouses. Space is a tough place. The environment is harsh, resources are limited and the room for errors is close to zero. If a robot can succeed in space than it can surely excel in the terrestrial industry as well. This and the fact that OffWorld builds a swarm approach that relies on a small form factor, intelligence and surgical precision, has the potential to reduce the total cost of operations, can shorten the life of mine or industrial operation and can be easily scaled up and down in size. With all these benefits in mind, OffWorld is looking into a reduction in the total cost of operations of at least an order of magnitude within any industrial sector. This paper will introduce the design philosophy behind OffWorld’s robotic work-force and will present the masterplan for developing space-bound systems by first maturing them in large scale deployments in terrestrial industries.

Already regarded as one of the top teams in Negro League baseball, the Kansas City Monarchs became known as a powerhouse unit in the 1930s and 40s. They rolled into towns with lights, amazing athletes, and competitive play. They won championship after championship during these years as Kansas City baseball fans strongly supported them. As they became an integral part of the city, the Monarchs' success, open-seating policy, and jazzy home openers fostered a large following of mixed-race fans. The local black newspaper, the Kansas City Call, held them up on a pedestal, while sportswriters for the mainstream Kansas City Star/Times downplayed the Monarchs' accomplishments and influence in the community. This thesis focuses on the relationship the Call had with the best team in black baseball through the context of its treatment of games, players, league officials, and team owners, as well as other patterns and tactics. Analysis of the Star/Times coverage is also considered to show variances in coverage between one city's race-divided newspapers. Negro League baseball and the African American newspapers that covered the teams grew out of and illustrated the segregation laws and prejudices feelings that existed in the United States during most of the twentieth century. Over time, especially when the sports world moved into the post-integration period, the Call's bolstering of the Monarchs deteriorated as the paper's promotion of democracy steered its sportswriters away from a baseball organization that symbolized segregation. The different types of coverage by the Call throughout the twenty-year study can be described as all-out promotion, balance, and abandonment. In the 1950s nostalgia and conflict existed, as the Call's sportswriters became torn on how to cover a team that was once the pride of the black community, but now represented inequality. In an attempt to remedy this torment, the Call tried to convince black baseball officials to remove the “Negro League” stigma by signing players of all races in order to mirror the more democratic Major Leagues. The white press, meanwhile, ignored the bigger issues of black baseball as one Negro League team after another died in the 1950s. The Star/Times peripheral coverage of the Monarchs provides context to the social issues and discriminatory practices at play in Missouri. As this thesis outlines the coverage of the Monarchs through the Black and White newspapers of Kansas City, previous research is substantiated and challenged to provide a fuller account of Jim Crow's effects.

Bei der jüngsten Umfrage des Instituts für Kommunikationswissenschaft der TU Dresden unter den Nutzern der SLUB (vgl. den ausführlichen Bericht im &quot;SLUB-Kurier 2006/3) wurde die SLUB insgesamt positiv bewertet, wobei insbesondere die Arbeitsbedingungen in den Bibliotheksgebäuden gute Noten bekamen....

Abstract Nearly four decades of reform and opening-up shows that China is one of the few successful cases of development. First, sustained high growth became a reality in China. China’s GNP grew by 32.19 times from 1978 to 2016 at constant prices, that is, an annual increase of 9.6%, of which the annual GDP growth hit 9.9% and 7.8% from 1978 to 2010 (high-speed growth) and from 2011 to 2016 (moderately high-speed growth) respectively on average.

Abstract‘The Anthropocene’ has emerged as a unique moment in earth history where humanity recognises its devastating capacity to destabilise the planetary processes upon which it depends. Modern agriculture plays a central role in this problematic. Food production innovations are needed that exceed traditional paradigms of the Green Revolution whilst at the same time are able to acknowledge the complexity arising from the sustainability and food security issues that mark our times. Aquaponics is one technological innovation that promises to contribute much towards these imperatives. But this emergent field is in an early stage that is characterised by limited resources, market uncertainty, institutional resistance and high risks of failure—a developmental environment where hype prevails over demonstrated outcomes. Given this situation, the aquaponics research community potentially holds an important place in the development path of this technology. But the field needs to craft a coherent and viable vision for this technology that can move beyond misplaced techno-optimist accounts. Turning to sustainability science and STS research, we discuss the urgent need to develop what we call a ‘critical sustainability knowledge’ for aquaponics, giving pointers for possible ways forward, which include (1) expanding aquaponic research into an interdisciplinary research domain, (2) opening research up to participatory approaches in real-world contexts and (3) pursuing a solution-oriented approach for sustainability and food security outcomes.

AbstractFinnish authorities provide undocumented migrants with at least emergency healthcare services, but very few (if any) undocumented migrants use these or other public healthcare services. There are challenges to accessing healthcare, including language, culture or communication, inadequate information, difficult opening times, lack of specialised services, fear of using such services, and lack of networks relating to social and healthcare services. The provision of wider healthcare services and prevention of illnesses is actually less expensive for countries than providing undocumented migrants with only emergency healthcare.This chapter discusses the undocumented migrants’ access to healthcare and their use of healthcare services. The Constitution of Finland guarantees emergency healthcare services for everyone staying in Finland, including undocumented migrants; however, the actual provision of healthcare (emergency or otherwise) for undocumented migrants varies greatly among local municipalities. Furthermore, few migrants use these available services. The majority turn to unofficial services, with some risk for themselves and the local community. The chapter highlights issues regarding the mental and physical health of undocumented migrants, who often suffer from trauma, which is not properly treated. It also discusses the effect of the COVID-19 pandemic on undocumented migrants in Finland.

A numerical study was performed to investigate the effect of ear openings on the dynamic brain response under blast loading condition. Transient nonlinear dynamic analysis of a cylindrical head was subjected to blast wave with a peak overpressure of 0.33 MPa and positive phase duration of 5 msec. The dynamic brain response is monitored in terms of intracranial pressures and shear stresses considering the opening in comparison to no opening case. The results have suggested increased intracranial pressures and shear stress in the brain with the presence of one opening. Furthermore, the opening also increased the fluctuation of stress wave through the skull with two times of increase in magnitude.

This paper presents results from two-dimensional finite element analyses of a centre cracked plate under both plane stress and plane strain conditions. The plate has been loaded in tension and secondary creep conditions have been assumed. The variation of the crack opening area with time has been calculated. It has been shown that the rate of change of the crack opening areas reduces with time up to the redistribution time which approximates the time to achieve steady creep conditions. Thereafter, the rate of change of crack opening area is constant. From curve fits to finite element results, a simplified expression for the rate of change of crack opening area of a stationary crack has been derived in terms of the elastic crack opening area, the creep strain rate, the elastic strain and two characteristic crack lengths (one for a strain field dominated by elastic strains and one for a strain field dominated by creep strains). This expression predicts the rate of change of the crack opening area both during the transient period up to the redistribution time and at all times thereafter.

Coal-fired supercritical power plants have steam generator liquid/vapor separator systems used during transition to/from “drum” mode and “once-through” mode, which undergo flow transients, involving control systems and valve openings, during startup and shutdown. These transients result in fluid acceleration which can produce significant reaction loads on piping systems (20 kips or higher). The evaluation of these loads is used to design piping supports and to assess possible control system and valving modifications. The computation of these transient loadings is challenging because the conditions in steam generator separator systems range from supercritical to subcritical, two phase, cold water or steam conditions occurring over a wide range of pressures and valve operating characteristics. A transient analysis of a typical separator-condensate line is performed using computer codes RELAP5/MOD3.2 and R5FORCE for the hydrodynamic forcetime history. A range of hydraulic loads associated with a range of operating conditions is provided in this paper using different boundary conditions for separator tank pressure, initial temperature of water in pipe lines, and control valve opening/closing times. These sensitivity runs show the benefit of plant control system changes to prevent the control valves opening above 1400 psia, increasing the control valve opening time to over one second, and the effects of keeping the separator-condensate line hot.

In secondary valve controlled discrete fluid power force systems the valve opening trajectory greatly influences the pressure dynamics in the actuator chambers. For discrete fluid power systems featuring hoses of significant length pressure oscillations due to fast valve switching is well-known. This paper builds upon theoretical findings on how shaping of the valve opening may reduce the cylinder pressure oscillations. The current paper extents the work by implementing the valve opening characteristics reducing the pressure oscillations on a full scale power take-off test-bench for wave energy converters. Further the energy losses introduced during the shifting period is investigated and compared for two valve opening algorithms. The investigation of the energy loss is utilised to quantify the importance of a fast valve switching and the energy cost of reducing pressure oscillations. The paper will present measurements comparing pressure dynamics for two valve opening algorithms. In addition the paper will give a theoretical investigation of the energy loss during valve shifting and finally measurements of average power output from the power take-off system in various sea states are compared for the three pressure shifting times.

The tragic accident of the Costa Concordia in January 2012 was one of the most severe large passenger ship accident in Europe in recent times followed by a tremendous public interest. We present the results of an in-depth technical investigation of the flooding sequence which lead to the heeling and grounding of the ship. A fast and explicit numerical flooding simulation method has been developed in the last years to better understand accidents like this one caused by complex and large scale flooding events. The flooding simulation is validated with the help of results from model tests and has been successfully applied to the investigation of several other severe ship accidents. It is based on a quasi-static approach in the time domain which evaluates the hydrostatic equilibrium at each time step. The water fluxes through the openings are computed by a hydraulic model based on the Bernoulli equation. Large and partly flooded openings are taken into account as well as conditional openings like the opening, closing and breaking of doors. The fluxes are integrated in the time domain by a predictor-corrector integration scheme to obtain the water volumes in each compartment involved in the flooding sequence. Due to the fact that the accident happened in calm water at moderate wind speeds close to the shore of the island Giglio this quasi-static numerical flooding simulation can be applied. The results of the technical investigation of the Costa Concordia accident obtained with the help of the developed method are presented. These results match well with the heel and trim motions observed during the accident and the chain of events which lead to the final position of the vessel on the rocks in front of the island Giglio. The explicit and direct approach of the method leads to a fast computational run-time of the numerical method. This allows to study several possible accident scenarios within a short period to investigate for example the influence of the opening and closing of watertight doors and to identify a most likely flooding scenario which lead to this tragic accident.

Abstract The development of actuators for flight control surfaces based on electrical technologies had a breakthrough in the last decade. Nevertheless, servo-hydraulic systems are still widely used. Servo Hydraulic Actuators (SHA) have the advantages of precise positioning, high dynamic response and being a jam-free solution in case of failures, but they present low energy efficiency. Digital hydraulics has become a topic of interest in improving energy efficiency in the fluid power community. A Digital Hydraulic Actuator (DHA) for aircraft is being developed to be used in primary flight control surfaces. The DHA concept is based on secondary control with multi-chamber cylinders and shows an energy efficiency gain with a similar response when compared to SHA. However, the opening and closing times of on/off valves are different and uncertain. These aspects may result in short circuits, bringing energy losses, or in blocked chambers, which may cause pressure peaks or cavitation. Consequently, the DHA system may have a lower energy efficiency or presents vibration due to fluid blocking. The present paper presents a solution for these issues and the reliability evaluation of the DHA. The opening and closing times issues are addressed using the synchronization between on/off valves through a method to find the correct time for valve opening control. As a result, the synchronization of pressure shifting without knowledge of the response times of on/off valves was accomplished. Moreover, when used periodically, this method can estimate future failures in valves due to a change of the required time delay. In order to evaluate the system reliability, FTA models were developed considering valve and pressure line failures, modelling how the failures affect force availability to move the control surfaces. The resulting FTAs were reduced to the minimum cut-sets that lead to force profiles that are insufficient for a safe flight and also may lead to an aircraft crash. Considering that the on/off valves have similar failure rates to those of servo valves, the results show that DHA and SHA have comparable reliability levels.

If in the case of consumer law, as protected persons are the consumers, then in the case of competition law, the protected entities are the competitors. A combination of actions in competition law presupposes that the same commercial offer satisfies several individual interests of consumers. In the strictest sense, such a combination implies the same legal fact, simultaneously opening up more possibilities for the consumer to choose due to loyal offers from a professional, if he is monopolistic or dominant in the market. More broadly, it can also be accepted that offers can be combined from several competing professionals relating to the same product or service and concerning the same individual interest of a consumer. The possible complementary effects of common law, which would justify the non-limitation of a specific piece of legislation, can never lead to a new monopoly. In some cases this will make competition law more effective and, in other cases, provide marginal and non-exclusive protection to consumers who do not have a direct right guaranteed by competition law. The purpose of this article is to demonstrate the interdependent relationship between competition law and consumer law, from the perspective that both have the same common goal, namely to limit abuses by professionals in their economic activity, especially during pandemic times.

Recent developments in the control of propagating ductile fractures in gas pipelines have proposed using the Crack Tip Opening Angle (CTOA) as a measure of fracture resistance. This is attractive as it can be related directly to the geometry of the fracturing pipe and also can be implemented easily in finite element models of the propagating fracture process. Current methods of determining CTOA in linepipe have been based on the standard DWTT specimen. This geometry often does not allow a fully slant fracture to develop, and is loaded in bending rather than tension. A novel specimen design has been developed to measure CTOA under quasi-static conditions and applied to a X80 (Grade 555) pipeline steel. The experimental work involved development of the design to ensure crack path stability. CTOA was obtained directly by measurement from video images. The CTOA values dropped from an initially high value to a steady state value of about 8 degrees when fully slant crack growth was achieved. This required crack growth over a distance of about 5 to 12 times the test section thickness. The crack growth was modeled numerically using the Gurson ductile void growth material model. The finite element modeling was able to qualitatively reproduce the crack path instability observed in practice, and the fall of CTOA from the initial high value to a steady state condition. Although further work is required to improve the modeling, the work carried out to date has demonstrated that there is the potential to apply damage mechanics methods to predict the laboratory specimen response and then to model the structural response.

High-volume fly ash concrete (HVFAC) is more cost-efficient, sustainable, and durable than conventional concrete. This report presents a state-of-the-art review of HVFAC properties and different fly ash characterization methods. The main challenges identified for HVFAC for pavements are its early-age properties such as air entrainment, setting time, and strength gain, which are the focus of this research. Five fly ash sources in Illinois have been repeatedly characterized through x-ray diffraction, x-ray fluorescence, and laser diffraction over time. The fly ash oxide compositions from the same source but different quarterly samples were overall consistent with most variations observed in SO3 and MgO content. The minerals present in various fly ash sources were similar over multiple quarters, with the mineral content varying. The types of carbon present in the fly ash were also characterized through x-ray photoelectron spectroscopy, loss on ignition, and foam index tests. A new computer vision–based digital foam index test was developed to automatically capture and quantify a video of the foam layer for better operator and laboratory reliability. The heat of hydration and setting times of HVFAC mixes for different cement and fly ash sources as well as chemical admixtures were investigated using an isothermal calorimeter. Class C HVFAC mixes had a higher sulfate imbalance than Class F mixes. The addition of chemical admixtures (both PCE- and lignosulfonate-based) delayed the hydration, with the delay higher for the PCE-based admixture. Both micro- and nano-limestone replacement were successful in accelerating the setting times, with nano-limestone being more effective than micro-limestone. A field test section constructed of HVFAC showed the feasibility and importance of using the noncontact ultrasound device to measure the final setting time as well as determine the saw-cutting time. Moreover, field implementation of the maturity method based on wireless thermal sensors demonstrated its viability for early opening strength, and only a few sensors with pavement depth are needed to estimate the field maturity.

The authors performed unsteady numerical simulations of virus/particle transport released from a hypothetical passenger aboard a commuter bus. The bus model was sized according to a typical city bus used to transport passengers within the city of Long Beach in California. The simulations were performed for the bus in transit and when the bus was at a bus stop opening the middle doors for 30 seconds for passenger boarding and drop off. The infected passenger was sitting in an aisle seat in the middle of the bus, releasing 1267 particles (viruses)/min. The bus ventilation system released air from two linear slots in the ceiling at 2097 cubic feet per minute (CFM) and the air was exhausted at the back of the bus. Results indicated high exposure for passengers sitting behind the infectious during the bus transit. With air exchange outside during the bus stop, particles were spread to seats in front of the infectious passenger, thus increasing the risk of infection for the passengers sitting in front of the infectious person. With higher exposure time, the risk of infection is increased. One of the most important factors in assessing infection risk of respiratory diseases is the spatial distribution of the airborne pathogens. The deposition of the particles/viruses within the human respiratory system depends on the size, shape, and weight of the virus, the morphology of the respiratory tract, as well as the subject’s breathing pattern. For the current investigation, the viruses are modeled as solid particles of fixed size. While the results provide details of particles transport within a bus along with the probable risk of infection for a short duration, however, these results should be taken as preliminary as there are other significant factors such as the virus’s survival rate, the size distribution of the virus, and the space ventilation rate and mixing that contribute to the risk of infection and have not been taken into account in this investigation.

In the decade after the Civil Rights Act of 1964, African Americans made historic gains in accessing employment opportunities in racially integrated workplaces in U.S. business firms and government agencies. In the previous working papers in this series, we have shown that in the 1960s and 1970s, Blacks without college degrees were gaining access to the American middle class by moving into well-paid unionized jobs in capital-intensive mass production industries. At that time, major U.S. companies paid these blue-collar workers middle-class wages, offered stable employment, and provided employees with health and retirement benefits. Of particular importance to Blacks was the opening up to them of unionized semiskilled operative and skilled craft jobs, for which in a number of industries, and particularly those in the automobile and electronic manufacturing sectors, there was strong demand. In addition, by the end of the 1970s, buoyed by affirmative action and the growth of public-service employment, Blacks were experiencing upward mobility through employment in government agencies at local, state, and federal levels as well as in civil-society organizations, largely funded by government, to operate social and community development programs aimed at urban areas where Blacks lived. By the end of the 1970s, there was an emergent blue-collar Black middle class in the United States. Most of these workers had no more than high-school educations but had sufficient earnings and benefits to provide their families with economic security, including realistic expectations that their children would have the opportunity to move up the economic ladder to join the ranks of the college-educated white-collar middle class. That is what had happened for whites in the post-World War II decades, and given the momentum provided by the dominant position of the United States in global manufacturing and the nation’s equal employment opportunity legislation, there was every reason to believe that Blacks would experience intergenerational upward mobility along a similar education-and-employment career path. That did not happen. Overall, the 1980s and 1990s were decades of economic growth in the United States. For the emerging blue-collar Black middle class, however, the experience was of job loss, economic insecurity, and downward mobility. As the twentieth century ended and the twenty-first century began, moreover, it became apparent that this downward spiral was not confined to Blacks. Whites with only high-school educations also saw their blue-collar employment opportunities disappear, accompanied by lower wages, fewer benefits, and less security for those who continued to find employment in these jobs. The distress experienced by white Americans with the decline of the blue-collar middle class follows the downward trajectory that has adversely affected the socioeconomic positions of the much more vulnerable blue-collar Black middle class from the early 1980s. In this paper, we document when, how, and why the unmaking of the blue-collar Black middle class occurred and intergenerational upward mobility of Blacks to the college-educated middle class was stifled. We focus on blue-collar layoffs and manufacturing-plant closings in an important sector for Black employment, the automobile industry from the early 1980s. We then document the adverse impact on Blacks that has occurred in government-sector employment in a financialized economy in which the dominant ideology is that concentration of income among the richest households promotes productive investment, with government spending only impeding that objective. Reduction of taxes primarily on the wealthy and the corporate sector, the ascendancy of political and economic beliefs that celebrate the efficiency and dynamism of “free market” business enterprise, and the denigration of the idea that government can solve social problems all combined to shrink government budgets, diminish regulatory enforcement, and scuttle initiatives that previously provided greater opportunity for African Americans in the government and civil-society sectors.

1.1 Macroeconomic summary Economic recovery has consistently outperformed the technical staff’s expectations following a steep decline in activity in the second quarter of 2020. At the same time, total and core inflation rates have fallen and remain at low levels, suggesting that a significant element of the reactivation of Colombia’s economy has been related to recovery in potential GDP. This would support the technical staff’s diagnosis of weak aggregate demand and ample excess capacity. The most recently available data on 2020 growth suggests a contraction in economic activity of 6.8%, lower than estimates from January’s Monetary Policy Report (-7.2%). High-frequency indicators suggest that economic performance was significantly more dynamic than expected in January, despite mobility restrictions and quarantine measures. This has also come amid declines in total and core inflation, the latter of which was below January projections if controlling for certain relative price changes. This suggests that the unexpected strength of recent growth contains elements of demand, and that excess capacity, while significant, could be lower than previously estimated. Nevertheless, uncertainty over the measurement of excess capacity continues to be unusually high and marked both by variations in the way different economic sectors and spending components have been affected by the pandemic, and by uneven price behavior. The size of excess capacity, and in particular the evolution of the pandemic in forthcoming quarters, constitute substantial risks to the macroeconomic forecast presented in this report. Despite the unexpected strength of the recovery, the technical staff continues to project ample excess capacity that is expected to remain on the forecast horizon, alongside core inflation that will likely remain below the target. Domestic demand remains below 2019 levels amid unusually significant uncertainty over the size of excess capacity in the economy. High national unemployment (14.6% for February 2021) reflects a loose labor market, while observed total and core inflation continue to be below 2%. Inflationary pressures from the exchange rate are expected to continue to be low, with relatively little pass-through on inflation. This would be compatible with a negative output gap. Excess productive capacity and the expectation of core inflation below the 3% target on the forecast horizon provide a basis for an expansive monetary policy posture. The technical staff’s assessment of certain shocks and their expected effects on the economy, as well as the presence of several sources of uncertainty and related assumptions about their potential macroeconomic impacts, remain a feature of this report. The coronavirus pandemic, in particular, continues to affect the public health environment, and the reopening of Colombia’s economy remains incomplete. The technical staff’s assessment is that the COVID-19 shock has affected both aggregate demand and supply, but that the impact on demand has been deeper and more persistent. Given this persistence, the central forecast accounts for a gradual tightening of the output gap in the absence of new waves of contagion, and as vaccination campaigns progress. The central forecast continues to include an expected increase of total and core inflation rates in the second quarter of 2021, alongside the lapse of the temporary price relief measures put in place in 2020. Additional COVID-19 outbreaks (of uncertain duration and intensity) represent a significant risk factor that could affect these projections. Additionally, the forecast continues to include an upward trend in sovereign risk premiums, reflected by higher levels of public debt that in the wake of the pandemic are likely to persist on the forecast horizon, even in the context of a fiscal adjustment. At the same time, the projection accounts for the shortterm effects on private domestic demand from a fiscal adjustment along the lines of the one currently being proposed by the national government. This would be compatible with a gradual recovery of private domestic demand in 2022. The size and characteristics of the fiscal adjustment that is ultimately implemented, as well as the corresponding market response, represent another source of forecast uncertainty. Newly available information offers evidence of the potential for significant changes to the macroeconomic scenario, though without altering the general diagnosis described above. The most recent data on inflation, growth, fiscal policy, and international financial conditions suggests a more dynamic economy than previously expected. However, a third wave of the pandemic has delayed the re-opening of Colombia’s economy and brought with it a deceleration in economic activity. Detailed descriptions of these considerations and subsequent changes to the macroeconomic forecast are presented below. The expected annual decline in GDP (-0.3%) in the first quarter of 2021 appears to have been less pronounced than projected in January (-4.8%). Partial closures in January to address a second wave of COVID-19 appear to have had a less significant negative impact on the economy than previously estimated. This is reflected in figures related to mobility, energy demand, industry and retail sales, foreign trade, commercial transactions from selected banks, and the national statistics agency’s (DANE) economic tracking indicator (ISE). Output is now expected to have declined annually in the first quarter by 0.3%. Private consumption likely continued to recover, registering levels somewhat above those from the previous year, while public consumption likely increased significantly. While a recovery in investment in both housing and in other buildings and structures is expected, overall investment levels in this case likely continued to be low, and gross fixed capital formation is expected to continue to show significant annual declines. Imports likely recovered to again outpace exports, though both are expected to register significant annual declines. Economic activity that outpaced projections, an increase in oil prices and other export products, and an expected increase in public spending this year account for the upward revision to the 2021 growth forecast (from 4.6% with a range between 2% and 6% in January, to 6.0% with a range between 3% and 7% in April). As a result, the output gap is expected to be smaller and to tighten more rapidly than projected in the previous report, though it is still expected to remain in negative territory on the forecast horizon. Wide forecast intervals reflect the fact that the future evolution of the COVID-19 pandemic remains a significant source of uncertainty on these projections. The delay in the recovery of economic activity as a result of the resurgence of COVID-19 in the first quarter appears to have been less significant than projected in the January report. The central forecast scenario expects this improved performance to continue in 2021 alongside increased consumer and business confidence. Low real interest rates and an active credit supply would also support this dynamic, and the overall conditions would be expected to spur a recovery in consumption and investment. Increased growth in public spending and public works based on the national government’s spending plan (Plan Financiero del Gobierno) are other factors to consider. Additionally, an expected recovery in global demand and higher projected prices for oil and coffee would further contribute to improved external revenues and would favor investment, in particular in the oil sector. Given the above, the technical staff’s 2021 growth forecast has been revised upward from 4.6% in January (range from 2% to 6%) to 6.0% in April (range from 3% to 7%). These projections account for the potential for the third wave of COVID-19 to have a larger and more persistent effect on the economy than the previous wave, while also supposing that there will not be any additional significant waves of the pandemic and that mobility restrictions will be relaxed as a result. Economic growth in 2022 is expected to be 3%, with a range between 1% and 5%. This figure would be lower than projected in the January report (3.6% with a range between 2% and 6%), due to a higher base of comparison given the upward revision to expected GDP in 2021. This forecast also takes into account the likely effects on private demand of a fiscal adjustment of the size currently being proposed by the national government, and which would come into effect in 2022. Excess in productive capacity is now expected to be lower than estimated in January but continues to be significant and affected by high levels of uncertainty, as reflected in the wide forecast intervals. The possibility of new waves of the virus (of uncertain intensity and duration) represents a significant downward risk to projected GDP growth, and is signaled by the lower limits of the ranges provided in this report. Inflation (1.51%) and inflation excluding food and regulated items (0.94%) declined in March compared to December, continuing below the 3% target. The decline in inflation in this period was below projections, explained in large part by unanticipated increases in the costs of certain foods (3.92%) and regulated items (1.52%). An increase in international food and shipping prices, increased foreign demand for beef, and specific upward pressures on perishable food supplies appear to explain a lower-than-expected deceleration in the consumer price index (CPI) for foods. An unexpected increase in regulated items prices came amid unanticipated increases in international fuel prices, on some utilities rates, and for regulated education prices. The decline in annual inflation excluding food and regulated items between December and March was in line with projections from January, though this included downward pressure from a significant reduction in telecommunications rates due to the imminent entry of a new operator. When controlling for the effects of this relative price change, inflation excluding food and regulated items exceeds levels forecast in the previous report. Within this indicator of core inflation, the CPI for goods (1.05%) accelerated due to a reversion of the effects of the VAT-free day in November, which was largely accounted for in February, and possibly by the transmission of a recent depreciation of the peso on domestic prices for certain items (electric and household appliances). For their part, services prices decelerated and showed the lowest rate of annual growth (0.89%) among the large consumer baskets in the CPI. Within the services basket, the annual change in rental prices continued to decline, while those services that continue to experience the most significant restrictions on returning to normal operations (tourism, cinemas, nightlife, etc.) continued to register significant price declines. As previously mentioned, telephone rates also fell significantly due to increased competition in the market. Total inflation is expected to continue to be affected by ample excesses in productive capacity for the remainder of 2021 and 2022, though less so than projected in January. As a result, convergence to the inflation target is now expected to be somewhat faster than estimated in the previous report, assuming the absence of significant additional outbreaks of COVID-19. The technical staff’s year-end inflation projections for 2021 and 2022 have increased, suggesting figures around 3% due largely to variation in food and regulated items prices. The projection for inflation excluding food and regulated items also increased, but remains below 3%. Price relief measures on indirect taxes implemented in 2020 are expected to lapse in the second quarter of 2021, generating a one-off effect on prices and temporarily affecting inflation excluding food and regulated items. However, indexation to low levels of past inflation, weak demand, and ample excess productive capacity are expected to keep core inflation below the target, near 2.3% at the end of 2021 (previously 2.1%). The reversion in 2021 of the effects of some price relief measures on utility rates from 2020 should lead to an increase in the CPI for regulated items in the second half of this year. Annual price changes are now expected to be higher than estimated in the January report due to an increased expected path for fuel prices and unanticipated increases in regulated education prices. The projection for the CPI for foods has increased compared to the previous report, taking into account certain factors that were not anticipated in January (a less favorable agricultural cycle, increased pressure from international prices, and transport costs). Given the above, year-end annual inflation for 2021 and 2022 is now expected to be 3% and 2.8%, respectively, which would be above projections from January (2.3% and 2,7%). For its part, expected inflation based on analyst surveys suggests year-end inflation in 2021 and 2022 of 2.8% and 3.1%, respectively. There remains significant uncertainty surrounding the inflation forecasts included in this report due to several factors: 1) the evolution of the pandemic; 2) the difficulty in evaluating the size and persistence of excess productive capacity; 3) the timing and manner in which price relief measures will lapse; and 4) the future behavior of food prices. Projected 2021 growth in foreign demand (4.4% to 5.2%) and the supposed average oil price (USD 53 to USD 61 per Brent benchmark barrel) were both revised upward. An increase in long-term international interest rates has been reflected in a depreciation of the peso and could result in relatively tighter external financial conditions for emerging market economies, including Colombia. Average growth among Colombia’s trade partners was greater than expected in the fourth quarter of 2020. This, together with a sizable fiscal stimulus approved in the United States and the onset of a massive global vaccination campaign, largely explains the projected increase in foreign demand growth in 2021. The resilience of the goods market in the face of global crisis and an expected normalization in international trade are additional factors. These considerations and the expected continuation of a gradual reduction of mobility restrictions abroad suggest that Colombia’s trade partners could grow on average by 5.2% in 2021 and around 3.4% in 2022. The improved prospects for global economic growth have led to an increase in current and expected oil prices. Production interruptions due to a heavy winter, reduced inventories, and increased supply restrictions instituted by producing countries have also contributed to the increase. Meanwhile, market forecasts and recent Federal Reserve pronouncements suggest that the benchmark interest rate in the U.S. will remain stable for the next two years. Nevertheless, a significant increase in public spending in the country has fostered expectations for greater growth and inflation, as well as increased uncertainty over the moment in which a normalization of monetary policy might begin. This has been reflected in an increase in long-term interest rates. In this context, emerging market economies in the region, including Colombia, have registered increases in sovereign risk premiums and long-term domestic interest rates, and a depreciation of local currencies against the dollar. Recent outbreaks of COVID-19 in several of these economies; limits on vaccine supply and the slow pace of immunization campaigns in some countries; a significant increase in public debt; and tensions between the United States and China, among other factors, all add to a high level of uncertainty surrounding interest rate spreads, external financing conditions, and the future performance of risk premiums. The impact that this environment could have on the exchange rate and on domestic financing conditions represent risks to the macroeconomic and monetary policy forecasts. Domestic financial conditions continue to favor recovery in economic activity. The transmission of reductions to the policy interest rate on credit rates has been significant. The banking portfolio continues to recover amid circumstances that have affected both the supply and demand for loans, and in which some credit risks have materialized. Preferential and ordinary commercial interest rates have fallen to a similar degree as the benchmark interest rate. As is generally the case, this transmission has come at a slower pace for consumer credit rates, and has been further delayed in the case of mortgage rates. Commercial credit levels stabilized above pre-pandemic levels in March, following an increase resulting from significant liquidity requirements for businesses in the second quarter of 2020. The consumer credit portfolio continued to recover and has now surpassed February 2020 levels, though overall growth in the portfolio remains low. At the same time, portfolio projections and default indicators have increased, and credit establishment earnings have come down. Despite this, credit disbursements continue to recover and solvency indicators remain well above regulatory minimums. 1.2 Monetary policy decision In its meetings in March and April the BDBR left the benchmark interest rate unchanged at 1.75%.