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Objectives The Police Districting Problem concerns the definition of patrol districts that distribute police resources in a territory in such a way that high-risk areas receive more patrolling time than low-risk areas, according to a principle of territorial fairness. This results in patrolling configurations that are efficient and effective at controlling crime but that, at the same time, might exacerbate racial disparity in police stops and arrests. In this paper, an Equitable Police Districting Problem that combines crime-reduction effectiveness with racial fairness is proposed. The capability of this model in designing patrolling configurations that find a balance between territorial and racial fairness is assessed. Also, the trade-off between these two criteria is analyzed. Methods The Equitable Police Districting Problem is defined as a mixed-integer program. The objective function is formulated using Compromise Programming and Goal Programming. The model is validated on a real-world case study on the Central District of Madrid, Spain, and its solutions are compared to standard patrolling configurations currently used by the police. Results A trade-off between racial fairness and crime control is detected. However, the experiments show that including the proposed racial criterion in the optimization of patrol districts greatly improves racial fairness with limited detriment to the policing effectiveness. Also, the model produces solutions that dominate the patrolling configurations currently in use by the police. Conclusions The results show that the model successfully provides a quantitative evaluation of the trade-off between the criteria and is capable of defining patrolling configurations that are efficient in terms of both racial and territorial fairness.

IntroductionEarly recognition and appropriate management of paediatric sepsis are known to improve outcomes. A previous system’s biology investigation of the systemic immune response in neonates to sepsis identified immune and metabolic markers that showed high accuracy for detecting bacterial infection. Further gene expression markers have also been reported previously in the paediatric age group for discriminating sepsis from control cases. More recently, specific gene signatures were identified to discriminate between COVID-19 and its associated inflammatory sequelae. Through the current prospective cohort study, we aim to evaluate immune and metabolic blood markers which discriminate between sepses (including COVID-19) from other acute illnesses in critically unwell children and young persons, up to 18 years of age.Methods and analysisWe describe a prospective cohort study for comparing the immune and metabolic whole-blood markers in patients with sepsis, COVID-19 and other illnesses. Clinical phenotyping and blood culture test results will provide a reference standard to evaluate the performance of blood markers from the research sample analysis. Serial sampling of whole blood (50 μL each) will be collected from children admitted to intensive care and with an acute illness to follow time dependent changes in biomarkers. An integrated lipidomics and RNASeq transcriptomics analyses will be conducted to evaluate immune-metabolic networks that discriminate sepsis and COVID-19 from other acute illnesses. This study received approval for deferred consent.Ethics and disseminationThe study has received research ethics committee approval from the Yorkshire and Humber Leeds West Research Ethics Committee 2 (reference 20/YH/0214; IRAS reference 250612). Submission of study results for publication will involve making available all anonymised primary and processed data on public repository sites.Trial registration numberNCT04904523.

Within the present investigation, a louver slot is employed upstream of an array full-coverage film cooling holes. Cooling air is supplied using a combination arrangement, with cross-flow and impingement together. The louver consists of a row of film cooling holes, contained within a specially designed device that concentrates and directs the coolant from a slot, so that it then advects as a layer downstream along the test surface. This louver-supplied coolant is then supplemented by coolant which emerges from different rows of downstream film cooling holes. The same coolant supply passage is employed for the louver row of holes, as well as for the film cooling holes, such that different louver and film cooling mass flowrates are set by different hole diameters for the two different types of cooling holes. The results are different from data provided by past investigations, because of the use and arrangement of the louver slot, and because of the unique coolant supply configurations. The experimental results are given for mainstream Reynolds numbers from 107,000 to 114,000. Full-coverage blowing ratios are constant with streamwise location along the test surface and range from 3.68 to 5.70. Corresponding louver slot blowing ratios then range from 1.72 to 2.65. Provided are heat transfer coefficient and adiabatic effectiveness distributions, which are measured along the mainstream side of the test plate. Both types of data show less variation with streamwise development location, relative to results obtained without a louver employed, when examined at the same approximate effective blowing ratio, mainstream Reynolds number, cross-flow Reynolds number, and impingement jet Reynolds number. When compared at the same effective blowing ratio or the same impingement jet Reynolds number, spanwise-averaged heat transfer coefficients are consistently lower, especially for the downstream regions of the test plate, when the louver is utilized. With the same type of comparisons, the presence of the louver slot results in significantly higher values of adiabatic film cooling effectiveness (spanwise-averaged), particularly at and near the upstream portions of the test plate. With such characteristics, dramatic increases in thermal protection are provided by the presence of the louver slot, the magnitudes of which vary with the experimental condition and test surface location.

Emphasis on lean premixed combustion in modern low NOx combustion chambers limits the availability of air for cooling the combustion liner. Hence the development of optimized liner cooling designs is imperative for effective usage of available coolant. Effusion cooling (also known as full-coverage film cooling) is a common method to cool the combustor liner, which involves uniformly spaced holes distributed throughout the liner curved surface area. This paper presents findings from an experimental study on the characterization of overall cooling effectiveness of an effusion-cooled liner wall, which was representative of a can combustor under heated flow (non-reacting) and lean-combustion (reacting) conditions. The model can-combustor was equipped with an industrial swirler, which subjected the liner walls to engine representative flow and combustion conditions. Inline and staggered arrangement of effusion holes have been studied. These configurations were tested for five different blowing ratios ranging from 0.7 to 4, under both reacting and non-reacting conditions. The experiments were carried out at a constant Reynolds number (based on combustor diameter) of 12,500. Infrared Thermography (IRT) was used to measure the liner outer surface temperature and detailed overall effectiveness values were determined under steady-state conditions. Under non-reacting conditions, the staggered configuration was found to be 9–25% more effective compared to inline configuration. Under reacting conditions, the staggered configuration was be 4–8% more effective compared to inline configuration. It is clear that the coolant-flame interaction for the reacting cases had a significant impact on the liner cooling effectiveness as compared to the non-reacting cases and results in less variation between inline and staggered configurations.

Modern combustor design optimization is contingent on the accurate characterization of the combustor flame side heat loads. Knowledge of regions of high and low heat loads on the liner wall helps designers optimize the cooling designs. The present work focuses on the experimental measurement of the transient heat load along a fused silica (quartz) optical can combustor under reacting conditions for a swirl stabilized premixed methane-air flame. Equivalence ratio was varied from 0.55 to 0.65. Reynolds number based on combustor diameter was varied from 12500 to 18000, where the preheated air temperature was approximately 373 K. The percentage of pilot fuel was varied from 6% to 10% of the main fuel flow rate. Inner and outer walls of the liner were painted with a high temperature flat black paint with an azimuthal offset to aid in infrared measurement of the wall temperature using an infrared camera. Particle Image Velocimetry (PIV) was employed to visualize the flow field for various reacting conditions studied in this work. Based on the heat transfer study, a detailed report of transient heat load along the length of the liner wall for varying reacting conditions has been presented here. The location of impingement of the flame onto the liner and velocity of the flow field were obtained from PIV measurements. Wall heat load at various planes along the length of the liner have been presented. Repeatability of this transient experiment was within 10% between eight different runs for various locations along the length of the liner, except for the region close to flame impingement zone. In the impingement zone, liner heat load varied by about 25% between different runs. It was observed that the change in heat load upstream of the location of impingement on the liner was insignificant with change in pilot ratio as the system tends towards a steady state, contrary to the regions downstream. Higher Reynolds number and equivalence ratios increased the heat load on the liner as expected.

The police districting problem concerns the efficient and effective design of patrol sectors in terms of performance attributes. Effectiveness is particularly important as it directly influences the ability of police agencies to stop and prevent crime. However, in this problem, a homogeneous distribution of workload is also desirable to guarantee fairness to the police agents and an increase in their satisfaction. This chapter provides a systematic review of the literature related to the police districting problem, whose history dates back to almost 50 years ago. Contributions are categorized in terms of attributes and solution methodology adopted. Also, an annotated bibliography that presents the most relevant elements of each research is given.

Disasters have catastrophic effects on the affected population, especially in developing and underdeveloped countries. Humanitarian Logistics models can help decision-makers to efficiently and effectively warehouse and distribute emergency goods to the affected population, to reduce casualties and suffering. However, poor planning and structural damage to the transportation infrastructure could hamper these efforts and, eventually, make it impossible to reach all the affected demand centers. In this paper, a pre-disaster Humanitarian Logistics model is presented that jointly optimizes the prepositioning of aid distribution centers and the strengthening of road sections to ensure that as much affected population as possible can efficiently get help. The model is stochastic in nature and considers that the demand in the centers affected by the disaster and the state of the transportation network are random. Uncertainty is represented through scenarios representing possible disasters. The methodology is applied to a real-world case study based on the 2018 storm system that hit the Nampula Province in Mozambique. The authors would like to thank the following entities, agencies and organizations for all the help and support provided: National Institute of Statistics (Mozambique), National Road Administration (Mozambique), National Institute of Disaster Management (Mozambique), Red Cross (Spain), Maputo International Airport, and the NGO ONGAWA. The research was partially funded by the European Commission’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie, grant number MSCA-RISE 691161 (GEO-SAFE); the Government of Spain, grant MTM2015-65803-R; the Complutense University of Madrid, scholarship Ayudas para la realización de estancias en proyectos de cooperación para el desarrollo sostenible. All the financial support is gratefully acknowledged.

The knowledge of detailed distribution of heat load on swirl stabilized combustor liner wall is imperative in the development of liner-specific cooling arrangements, aimed towards maintaining uniform liner wall temperatures for reduced thermal stress levels. Heat transfer and fluid flow experiments have been conducted on a swirl stabilized lean premixed combustor to understand the behavior of Methane-, Propane-, and Butane-based flames. These fuels were compared at different equivalence ratios for a matching adiabatic flame temperature of Methane at 0.65 equivalence ratio. Above experiments were carried out a fixed Reynolds number (based on the combustor diameter) of 12000, where the pre-heated air temperature was approximately 373K. Combustor liner in this setup was made from 4 mm thick quartz tube. An infrared camera was used to record the inner and outer temperatures of liner wall, and two-dimensional heat conduction model was used to find the wall heat flux at a quasi-steady state condition. Flow field in the combustor was measured through Particle Image Velocimetry. The variation of peak heat flux on the liner wall, position of peak heat flux and heat transfer, and position of impingement of flame on the liner have been presented in this study. For all three gaseous fuels studied, the major swirl stabilized flame features such as corner recirculation zone, central recirculation zone and shear layers have been observed to be similar. Liner wall and exhaust temperature for Butane was highest among the fuel tested in this study which was expected as the heat released from combustion of Butane is higher than that of Methane and Propane.

The present study provides new heat transfer data for both the surfaces of the full coverage effusion cooling plate within a double wall cooling test facility. To produce the cooling stream, a cold-side cross-flow supply for the effusion hole array is employed. Also utilized is a unique mainstream mesh heater, which provides transient thermal boundary conditions, after mainstream flow conditions are established. For the effusion cooled surface, presented are spatially-resolved distributions of surface adiabatic film cooling effectiveness, and surface heat transfer coefficients (measured using infrared thermography). For the coolant side, presented are spatially-resolved distributions of surface Nusselt numbers (measured using liquid crystal thermography). Of interest are the effects of streamwise development, blowing ratio, and Reynolds number. Streamwise hole spacing and spanwise hole spacing (normalized by effusion hole diameter) on the effusion plate are 15 and 4, respectively. Effusion hole diameter is 6.35 mm, effusion hole angle is 25°, and effusion plate thickness is 3 hole diameters. Considered are overall effusion blowing ratios from 2.9 to 7.5, with subsonic, incompressible flow, and constant freestream velocity with streamwise development, for two different mainstream Reynolds numbers. For the hot side (mainstream) of the effusion film cooling test plate, results for two mainflow Reynolds numbers of about 145000 and 96000 show that the adiabatic cooling effectiveness is generally higher for the lower Reynolds number for a particular streamwise location and blowing ratio. The heat transfer coefficient is generally higher for the low Reynolds number flow. This is due to altered supply passage flow behavior, which causes a reduction in coolant lift-off of the film from the surface as coolant momentum, relative to mainstream momentum, decreases. For the coolant side of the effusion test plate, Nusselt numbers generally increase with blowing ratio, when compared at a particular streamwise location and mainflow Reynolds number.

Gender violence is a problem that affects millions of people worldwide. Among its many manifestations Intimate Partner Violence (IPV) is one of the most common. In Spain, a police monitoring protocol has been developed to minimize recidivism in IPV cases. This protocol is complemented by VioGen, an Intimate Partner Violence Risk Assessment Tool (IPVRAT) created by the Spanish State Secretariat for Security of the Ministry of Interior (SES) for risk prediction. VioGen’s goal is to help the authorities determine what security and safety measures are most suitable. This paper improves on the current version of VioGen by introducing a model based on machine learning and data science and by studying the predictive value of exogenous and historical variables. The model is fitted on an anonymized database provided by SES and extracted from VioGen. This database includes the 2-year evolution of 46,047 new cases of IPV violence reported between October 2016 and December 2017, making it the largest database analyzed in the field. Obtained results show a clear improvement in the predictive capabilities of the new model against the original system, where it would have corrected more than 25% of the infra-protected cases, while improving the overall accuracy at the same time. Finally, lessons learned from the performed study and experiments are reported to aid in the design of future IPVRAT. In particular, insights show that IPVRAT should not treat cases statically as the incorporation of information regarding their evolution improves significantly the model’s performance.

Louver slot cooling is employed, which consists of an aligned collection of film cooling holes, contained within a specially-designed device which concentrates, and directs the coolant from a slot, so that cooling air then advects as a layer downstream along the test surface. This louver-supplied coolant is then supplemented by coolant which emerges from different rows of downstream film cooling holes. Coolant for both cooling arrangements is supplied using an array of impingement jets. Experimental data are provided for a mainstream Reynolds number Rems range of 168,000–181,000. Full-coverage film cooling initial blowing ratio values are 2.5, 3.2, 4.4, and 5.2, with respective louver slot blowing ratios of 1.2, 1.5, 2.1, and 2.4. Measured lateral-averaged adiabatic effectiveness results show that, with impingement supply cooling only, for blowing ratios of 4.4 and lower, the louver and effusion cooling arrangement generally provides higher effectiveness, relative to an effusion cooling only arrangement. For all blowing ratios considered, another advantage of the louver slot is more uniform values of increased effectiveness along the entire test surface, including locations which are just downstream of the slot. Relatively weak dependence on blowing ratio is present for the louver and film cooling arrangement, in contrast to the effusion only configuration, where effectiveness data generally increase progressively and substantially (at most x/de locations) as the blowing ratio becomes larger. Lateral-averaged heat transfer coefficient values for the effusion cooling only arrangement, and for the louver and effusion cooling arrangement, are approximately quantitatively similar when the blowing ratio is 4.3 to 4.4. Data for blowing ratios BR of 5.2 to 5.5 show that the louver and effusion cooling gives much lower lateral-averaged heat transfer coefficients, compared to the effusion cooling only arrangement. This is a result of reduced local turbulent thermal transport levels within the wake flows which are present downstream of the louver leap device.

Most of existing network-based decision-support systems, such as recommender systems, require knowing users’ social context and, thus, the strength of their interactions. However, previous studies related to the usage and estimation of tie strength either assume that this parameter is given or use a computational model of their own. The amount, variety and domain specific information required to apply these models makes the reproducing and reusing of existing results extremely costly or utterly impossible. In our research, we show empirically the relative importance of different social variables for the computation of the tie strength and propose a computational model independent of the Social Networks’ domain. Our experiments are based on a dataset obtained from a survey that involved more than 100 participants and comprised more than 500 social ties. The dataset is the first publicly available dataset to explicitly include tie strength measures.

The present study considers comparisons of hot-side effusion plate results for a mainstream flow passage with CR = 1 and for a mainstream flow passage with CR = 4. The coolant supply arrangement for both CR contraction ratio values includes simultaneous use of cross flow and an impingement jet array. For the effusion cooled/hot surface, presented are spatially-resolved distributions of surface adiabatic film cooling effectiveness, and surface heat transfer coefficients (measured using infrared thermography). These results are given for main flow Reynolds numbers Rems of 89,900 to 95,800. For this main flow Reynolds number range, four different combination values of crossflow Reynolds number and impingement Reynolds number are tested for each CR value, which are associated with four different values of initial blowing ratio BR. With this arrangement, crossflow Reynolds number is varied, as impingement jet Reynolds number is approximately constant. The resulting variations of surface adiabatic film cooling effectiveness and surface heat transfer coefficients are due to three competing phenomena, whose relative influences change with x/de location. These include increased turbulent mixing and transport result from effusion coolant jets, decreased magnitudes of local blowing ratio with streamwise location, and significant streamwise acceleration, which induces local boundary layer re-laminarization. When the CR = 4 arrangement is employed, these phenomena result in dramatic decreases of local and line-averaged heat transfer coefficients, and local and line-averaged adiabatic film effectiveness magnitudes, with streamwise development, for x/de > 60. Resulting values are then significantly lower than when CR = 1, provided comparisons are made at a particular streamwise location for each value of initial blowing ratio BR.

Considered is double wall cooling, with full-coverage effusion-cooling on the hot side of the effusion plate, and a combination of impingement cooling and cross flow cooling, employed together on the cold side of the effusion plate. Data are given for a main stream flow passage with a contraction ratio (CR) of 4 for main stream Reynolds numbers Rems and Rems,avg of 157,000–161,000 and 233,000–244,000, respectively. Hot-side measurements (on the main stream flow or hot side of the effusion plate) are presented, which are measured using infrared thermography. Using a transient thermal measurement approach, measured are spatially resolved distributions of surface adiabatic film cooling effectiveness, and surface heat transfer coefficient. For the same Reynolds number, initial blowing ratio (BR), and streamwise location, increased thermal protection is often provided when the effusion coolant is provided by the cross flow/impingement combination configuration, compared to the cross flow only supply arrangement. In general, higher adiabatic effectiveness values are provided by the impingement only arrangement, relative to the impingement/cross flow combination configuration, when compared at the same Reynolds number, initial BR, and x/de location. Data for one streamwise location of x/de = 60 show that the highest net heat flux reduction line-averaged net heat flux reduction (NHFR) values are produced either by the impingement/cross flow combination configuration or by the impingement only arrangement, depending upon the particular magnitude of BR, which is considered.

The present study provides new effusion cooling data for both the surfaces of the full-coverage effusion cooling plate. For the effusion-cooled surface, presented are spatially resolved distributions of surface adiabatic film cooling effectiveness and surface heat transfer coefficients (measured using transient techniques and infrared thermography). For the impingement-cooled surface, presented are spatially resolved distributions of surface Nusselt numbers (measured using steady-state liquid crystal thermography). To produce this cool-side augmentation, impingement jet arrays at different jet Reynolds numbers, from 2720 to 11,100, are employed. Experimental data are given for a sparse effusion hole array, with spanwise and streamwise impingement hole spacing such that coolant jet hole centerlines are located midway between individual effusion hole entrances. Considered are the initial effusion blowing ratios from 3.3 to 7.5, with subsonic, incompressible flow. The velocity of the freestream flow which is adjacent to the effusion-cooled boundary layer is increasing with streamwise distance, due to a favorable streamwise pressure gradient. Such variations are provided by a main flow passage contraction ratio CR of 4. Of particular interest are effects of impingement jet Reynolds number, effusion blowing ratio, and streamwise development. Also, included are comparisons of impingement jet array cooling results with: (i) results associated with crossflow supply cooling with CR = 1 and CR = 4 and (ii) results associated with impingement supply cooling with CR = 1, when the mainstream pressure gradient is near zero. Overall, the present results show that, for the same main flow Reynolds number, approximate initial blowing ratio, and streamwise location, significantly increased thermal protection is generally provided when the effusion coolant is provided by an array of impingement cooling jets, compared to a crossflow coolant supply.

Experimentally measured results are presented for different experimental conditions for a test plate with double wall cooling, composed of full-coverage effusion-cooling on the hot side of the plate, and cross-flow cooling on the cold side of the plate. The results presented are different from those from past investigations, because of the addition of a significant mainstream pressure gradient. Main stream flow is provided along a passage with a contraction ratio of 4, given by the ratio upstream flow area, to downstream flow area. With this arrangement, local blowing ratio decreases significantly with streamwise development along the test section, for every value of initial blowing ratio considered, where this initial value is determined at the most upstream row of effusion holes. Experimental data are given for a sparse effusion hole array. The experimental results are provided for mainstream Reynolds numbers of 92,400–96,600, and from 128,400 to 135,000, and initial blowing ratios of 3.3–3.6, 4.4, 5.2, 6.1–6.3, and 7.3–7.4. Results illustrate the effects of blowing ratio for the hot side and the cold side of the effusion plate. Of particular interest are values of line-averaged film cooling effectiveness and line-averaged heat transfer coefficient, which are generally different for contraction ratio of 4, compared to a contraction ratio of 1, because of different amounts and concentrations of effusion coolant near the test surface. In regard to cold-side measurements on the crossflow side of the effusion plate, line-averaged Nusselt numbers for contraction ratio 4 are often less than values for contraction ratio 1, when compared at the same main flow Reynolds number, initial blowing ratio, and streamwise location.