Incarceration is a pervasive issue in the United States that is enormously costly to families, communities, and society at large. The path from prison back to prison may depend on the relationship a person has with their probation or parole officer (PPO). If the relationship lacks appropriate care and trust, violations and recidivism (return to jail or prison) may be more likely to occur. Here, we test whether an “empathic supervision” intervention with PPOs—that aims to reduce collective blame against and promote empathy for the perspectives of adults on probation or parole (APPs)—can reduce rates of violations and recidivism. The intervention highlights the unreasonable expectation that all APPs will reoffend (collective blame) and the benefits of empathy—valuing APPs’ perspectives. Using both within-subject (monthly official records for 10 mo) and between-subject (treatment versus control) comparisons in a longitudinal study with PPOs in a large US city (NPPOs = 216; NAPPs=∼20,478), we find that the empathic supervision intervention reduced collective blame against APPs 10 mo postintervention and reduced between-subject violations and recidivism, a 13% reduction that would translate to less taxpayer costs if scaled. Together, these findings illustrate that very low-cost psychological interventions that target empathy in relationships can be cost effective and combat important societal outcomes in a lasting manner.

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Researchers have long used end-of-year discipline rates to identify punitive schools, explore sources of inequitable treatment, and evaluate interventions designed to stem both discipline and racial disparities in discipline. Yet, this approach leaves us with a “static view”—with no sense of how disciplinary responses fluctuate throughout the year. What if daily discipline rates, and daily discipline disparities, shift over the school year in ways that could inform when and where to intervene? This research takes a “dynamic view” of discipline. It leverages 4 years of atypically detailed data regarding the daily disciplinary experiences of 46,964 students from 61 middle schools in one of the nation’s largest school districts. Reviewing these data, we find that discipline rates are indeed dynamic. For all student groups, the daily discipline rate grows from the beginning of the school year to the weeks leading up to the Thanksgiving break, falls before major breaks, and grows following major breaks. During periods of escalation, the daily discipline rate for Black students grows significantly faster than the rate for White students—widening racial disparities. Given this, districts hoping to stem discipline and disparities may benefit from timing interventions to precede these disciplinary spikes. In addition, early-year Black–White disparities can be used to identify the schools in which Black–White disparities are most likely to emerge by the end of the school year. Thus, the results reported here provide insights regarding not only when to intervene, but where to intervene to reduce discipline rates and disparities.

This paper presents an experimental study of the heat transfer and pressure drop characteristics of a single phase high heat flux microchannel cooling system with spiraling radial inflow. The heat sink provides enhanced heat transfer with a simple inlet and outlet design while providing uniform flow distribution. The system is heated from one conducting wall made of copper and uses water as a working fluid. The microchannel has a 1 cm radius and a 300 μm gap height. Experimental results show, on average, a 76% larger pressure drop compared to an analytic model for laminar flow in a parallel disk system with spiral radial inflow. The mean heat transfer coefficients measured are up to four times the heat transfer coefficient for unidirectional laminar fully developed flow between parallel plates with the same gap height. Flow visualization studies indicate the presence of secondary flows and the onset of turbulence at higher flow rates. Combined with the thermally developing nature of the flow, these characteristics lead to enhanced heat transfer coefficients relative to the laminar parallel plate values. Another beneficial feature of this device, for high heat flux cooling applications, is that the thermal gradients on the surface are small. The average variation in surface temperature is 18% of the total bulk fluid temperature gain across the device. The system showed promising cooling characteristics for electronics and concentrated photovoltaics applications with a heat flux of 113 W/cm2 at a surface temperature of 77 °C and a ratio of pumping power to heat rate of 0.03%.

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This study presents an experimental exploration of flow boiling heat transfer in a spiraling radial inflow microchannel heat sink. The effect of surface wettability, fluid subcooling levels, and mass fluxes are considered in this type of heat sink for use in applications with high fluxes up to 300 W/cm2. The design of the heat sink provides an inward radial swirl flow between parallel, coaxial disks that form a microchannel of 300 μm and 1 cm radius with a single inlet and a single outlet. The channel is heated on one side through a copper conducting surface, while the opposite side is essentially adiabatic to simulate a heat sink scenario for electronics cooling. Flow boiling heat transfer and pressure drop data were obtained for this heat sink device using water at near atmospheric pressure as the working fluid for inlet subcooling levels from 20 to 81°C and mean mass flux levels ranging from 184 to 716 kg/m2s. To explore the effects of varying surface wetting, experiments were conducted with two different heated surfaces. One was a clean, machined copper surface with water equilibrium contact angles in the range of 14–40°, typical of common metal surfaces. The other was a surface coated with zinc oxide nanostructures that are superhydrophilic with equilibrium contact angles measured below 10°. During boiling, increased wettability resulted in quicker rewetting and smaller bubble departure diameter as indicated by reduced temperature oscillations during boiling and achieving higher maximum heat flux without dryout. Reducing inlet subcooling levels was also found to reduce the magnitude of oscillations in the oscillatory boiling regime. The highest heat transfer coefficients were seen in fully developed boiling with low subcooling levels as a result of heat transfer being dominated by nucleate boiling. The highest heat fluxes achieved were during partial subcooled flow boiling at 300 W/cm2 with an average surface temperature of 134 °C and requiring a pumping power to heat rate ratio of 0.01%. The hydrophilic surface retained wettability after a series of boiling tests. Recommendations for use of this heat sink design in high flux applications is also discussed.

Gibraltar is one of the few remaining British colonies and the historical development of medical services on the Rock, named after its Moorish conqueror Gebel Tariq in AD 700, has been reviewed by Montegriffo (1978). The Rock provides a useful small community for studying the mental health of its population, being 1 × 3 miles in area and with a population of 29,166 (1986 census). The population has remained static for the last decade with the male/female ratio 15/14. There were 507 births, male/female ratio 254/253 and 290 deaths (154 males and 136 females, 1986 census). The age distribution has altered; the percentage over 65 years in 1970, 9.8% and in 1980, 11.2%.

The energy conversion effectiveness of the central receiver absorber in concentrating solar thermal power systems is dictated primarily by heat losses, material temperature limits, and pumping power losses. To deliver concentrated solar energy to a gas for process heat applications or gas cycle power generation, there are a wide variety of compact heat exchanger finned surfaces that could be used to enhance the convective transfer of absorbed solar energy to the gas stream flowing through the absorber. In such circumstances, a key design objective for the absorber is to maximize the heat transfer thermodynamic performance while minimizing the pumping power necessary to drive the gas flow through the fin matrix. This paper explores the use of different performance metrics to quantify the combined heat transfer, thermodynamic and pressure loss effectiveness of enhanced fins surfaces used in solar thermal absorbers for gas heating. Previously defined heat exchanger performance metrics, such as the “goodness factor”, are considered, and we develop and explore the use of a new metric, the “loss factor”, for determining the preferred enhanced fin matrix surfaces for concentrated solar absorbers. The loss factor, defined as the normalized exergy loss in the receiver, can be used for nondimensional analysis of the desirable qualities in an optimized solar receiver design. In comparison to previous goodness factor methods, the loss factor metric has the advantage that it quantifies the trade-off between trying to maximize the solar exergy transferred to the gas (high heat transfer rate and delivery at high temperature) and minimizing the pumping exergy loss. In this study, the loss factor is used to compare current solar receiver designs, and designs that use a variety of available plate-finned compact heat transfer surfaces with known Colburn factor (j) and friction factor (f) characteristics. These examples demonstrate how the loss factor metric can be used to design and optimize novel solar central receiver systems, and they indicate fin matrix surfaces that are particularly attractive for this type of application.