Large Impact Research Articles

Factors Determining Household Waste Segregation Behaviour: An Indian Case Study

Waste represents used things or materials that are no longer required or wanted. These articles are cast off as they have stopped working or because they have ceased to be of value. Human settlements inevitably generate waste. According to UNEP's Global Waste Management Outlook 2024, the quantity of waste being generated is growing each year due to augmented economic growth accompanied with untenable consumption and production practices. In fact, global municipal solid waste (MSW) generation per year is projected to grow from 2.1 billion tonnes in 2020 to 2.7 billion tonnes in 2030 and further to 3.2 and 3.8 billion tonnes in 2040 and 2050 respectively. According to the World Bank, more than a third of waste generated globally is not managed in an environmentally sound manner and emissions related to solid waste are likely to increase to 2.6 billion tons of carbon dioxide equivalent by 2050. The present study based in Delhi with a sample of 708 households aims to understand the factors influencing the adoption of the “practice of waste segregation” by households. From our SEM and Path analysis we conclude that environmental awareness, knowledge about waste segregation and the perception about actual task of waste segregation have a significant impact on the practice of waste segregation. Environmental awareness has the largest impact followed by knowledge about how to undertake the task of waste segregation. In the light of our results, it is important and imperative to create awareness about the negative environmental impact of not segregating waste as well as demystifying the actual task of practising waste segregation.

Projected navigability of Arctic shipping routes based on climate model FIO-ESM v2.1

As Arctic sea ice has rapidly declined, the navigational potential of the Arctic routes has greatly increased. Based on sea ice output from the First Institute Of Oceanography-Earth System Model version 2.1 (FIO-ESM v2.1) and the Arctic Transport Accessibility Model, this study investigates the future navigability of the Arctic routes for open-water ships (OW) without icebreaking capabilities and ships with different icebreaking capabilities, namely Polar Class 7 (PC7), Polar Class 6 (PC6), and Polar Class 3 (PC3). The results show that the simulations of FIO-ESM v2.1 adequately reproduce the changes in the navigability of the four types of ships in Arctic shipping routes over the past 40 years. The navigable area for the four ship types is projected to continue to expand in the future. Under the high emission scenario (Shared Socioeconomic Pathways 5–8.5, SSP585), the four ship types are projected to achieve full Arctic navigability in summer (September) by the end of the 21st century, and PC6 and PC3 ships are projected to achieve full Arctic navigability in winter (March). Under the high emission scenario, year-round navigability in the Northwest Passage is projected for PC3 and PC6 ships, and in the Northeast Passage is projected for all four types of ships. The impact of emission scenario on the navigability of the Arctic shipping routes varies with different ship types: the largest impact is for OW ships, followed by PC6 and PC7 ships, and the smallest impact is for PC3 ships. The impact of scenario is also larger in winter than in summer.

A Comparison Between Water Addition and CO2 Addition to a Diffusion Coflow Flame

ABSTRACT This work compares the effects of adding water vapor and CO2 as diluent to fuel for a diffusion flame at different ambient pressures. The approach of this research is to study numerically a methane diffusion flame with various amounts of water vapor and CO2 added to the fuel, and to compare the flame behaviors with various percentages of water vapor and CO2 content (0% to 65%). This work uses a coflow burner in the PeleLM numerical framework for simulating the flame and computing the combustion behavior. The flame was simulated with pressures of 1.0, 1.4, 5.7, and 11.1 atm. The results extracted and analyzed include temperature profiles at fixed heights and various species mole fractions compared with their values at an equilibrium state condition. The results show that most of the diluent impact does not involve changes in flame chemistry but primarily changes to heat release and heat capacity in the flames. The results also show that the diluent amount has a much larger impact on flame behavior than do changes in pressure.

Impacts of Shocks to U.S. Macroeconomic Variables on the Regional Economy of Georgia

This paper develops a way to analyze a regional economy and a large economy within a model. Using structural autoregression with block exogeneity and mutual independence assumptions as well as Cholesky factorization, we quantify the impacts of shocks to U.S. macroeconomic variables on the regional economy of Georgia. We found that the largest impact on Georgia's aggregate variables - consumer prices, real per capita personal income, and total employment - is the federal funds rate. For other shocks, Georgia's personal income is most affected by an increase in commodity prices, while Georgia's consumer prices are most affected by U.S. inflation. At the industry level, we found that the impact of real GDP is the largest and the impact of M2 is the smallest on output and employment in Georgia's industries, although the magnitude of the impact on employment is smaller and more short-lived than on output.

The reward and penalty for ozone pollution control caused by natural sources and regional transport: A case study in Guangdong province

Ground-level O3 pollution in the Pearl River Delta region (PRD) is closely related to anthropogenic, natural emissions and regional transport. However, the interactions among different sources and natural intervention in modulating anthropogenic management have not been comprehensively assessed. Here, the WRF-CMAQ-MEGAN modeling system was utilized to simulate an O3 episode over PRD. The integrated source apportionment method (ISAM) and brute-force top-down combined with factor separation approach (BF-TD-FSA) were applied to quantify source contributions, impacts of individual or multiple sources on O3, and decouple interactions among various emissions; additionally, based on ISAM, O3 isopleths visualized MDA8 O3 response of different source types to anthropogenic perturbations. ISAM concluded considerable MDA8 O3 contributions of regional transport in PRD/NPRD (non-PRD areas in Guangdong province) (38.8 %/35.7 %), followed by anthropogenic (32.7 %/24.8 %), BVOC (biogenic volatile organic compounds, 23.8 %/20.3 %) and SNO (soil NO, ∼4 %) emissions. Compared to concentrated anthropogenic contributions, widespread natural contributions were observed across their source areas and along the transport pathways. The BF-TD also revealed that regional transport had the largest impact (>90 μg m−3) on MDA8 O3 while anthropogenic and BVOC emissions greatly affected downwind PRD (64.5 and 7.7 μg m−3). Negative synergy between anthropogenic and natural emissions (especially BVOC emission) suggested potential natural-induced intensification of anthropogenic impact during O3 management. The MDA8 O3 isopleths further demonstrated significant BVOC-induced reward and regional transport-induced penalty for anthropogenic NOx (ANOx) emission control benefits, leading to additional maximum MDA8 O3 decrease and increase by −27.5 and 13.8 μg m−3 in polluted high-emission grids. The natural-induced reward effect could impose loose requirements on anthropogenic reduction (decreased by 13.3 %–17.7 %) if there were no regional transport-induced control penalty. It is advisable to prioritize ANOx control and seek collaboration on air quality management with neighboring provinces to maximize the natural-induced control reward and achieve desired targets with minimal human efforts.

Rape Myths and Verdict Systems: What Is Influencing Conviction Rates in Rape Trials in Scotland?

The Scottish verdict system includes three verdicts: 'guilty', 'not guilty' and 'not proven'. Politicians propose that the three-verdict system is partially to blame for the low conviction rate of rape, whereas research suggests that rape myths may be having a larger impact. To test the effects of varying verdict systems (guilty, not guilty and not proven; guilty and not guilty; a series of proven and not proven verdicts) and rape myths on juror verdicts. A total of 180 participants answered questions regarding their acceptance of rape myths using the Acceptance of Modern Myth and Sexual Aggression (AMMSA) scale. They then watched a staged rape trial filmed in a real courtroom and reached a verdict. Participants also provided longer-form answers on which thematical analysis was conducted. The main findings are as follows: (1) The special verdict system leads to a higher conviction rate than the other systems when rape myth acceptance is controlled for. (2) The higher the rape myth acceptance, the more favourably the accused was perceived and the less favourably the complainer was perceived.

Soil Physicochemical Properties under Selected Avocado Cultivars in Ethiopian Smallholder Agroforestry

This study investigated the impact of three avocado cultivars on selected soil physicochemical properties in Central Ethiopia, to enhance the knowledge on the influence of avocado cultivars on soil physicochemical properties, and assist smallholders in cultivar selection in agroforestry. Trees planted in farmers´ fields 8 years earlier were revisited. Soil samples were collected from 0–20 cm and 20–40 cm depth at three radial distances from trees (1 m and 2 m from tree trunk, and at 5 m from the canopy edge as a control). Soil texture, bulk density, moisture content, pH, electrical conductivity, soil organic carbon, total nitrogen and available phosphorus were determined. Soil moisture content and electrical conductivity were overall higher and bulk density was lower (p < 0.05) under the canopies of the avocado trees than in the control and soil organic carbon, total nitrogen and available phosphorus tended to increase in spite of nutrient inputs to the control whilst the trees were unfertilized. Differences between the studied cultivars were small, but Hass tended to have the largest impact on soil nutrient levels, whilst Ettinger and Nabal tended to have a somewhat larger effect on the soil organic carbon concentration. Integrating these avocado cultivars on farms can improve soil fertility in the study area. However, for optimal agricultural soil health and sustainable avocado production, cultivar and site-specific soil management practices must be applied.

Impact of an instructional team's feedback on an instructor's teaching practices in a Biology of Cancer course.

The effective implementation of evidence-based teaching (EBT) in large college courses benefits from the successful use of instructional teams. An instructional team's feedback allows instructors to act based on evidence of student learning, addressing students' needs. This feedback may be particularly important for novice instructors or experienced instructors teaching a class for the first time. This study sought to characterize the nature of an instructional team's feedback as well as its influence on the decisions and actions of a seasoned instructor teaching a new class. Instructional team members provided feedback in the form of anticipations, noticings, and suggestions. Anticipations and suggestions seemed to have the largest impact on the instructor's decisions and actions, while noticings, despite providing insights into student thinking, had a smaller effect. Our findings indicate that an instructional team can provide valuable feedback to instructors when team members have an opportunity to meaningfully participate in the planning and teaching processes.

The interactive effect of geopolitical risk and natural resource rent on political instability: Evidence from Ghana

AbstractBackgroundAccording to economists, political instability is regarded as a serious malaise harmful to economic development, which results in frequent switches of policies, creating instability to impede economic performance. The widespread political instability in many developing countries, along with its harmful effects on social welfare and economic performance, has heightened the interest of policymakers and economists in understanding the factors that contribute to political instability to inform better policy formulation. It is therefore imperative to examine the interactive effect of geopolitical risk and natural resource rent on political instability to provide strong empirical grounds for policy implementation.ObjectivesThis study employs a long time series dating from the period of 1824–2020 to examine how natural resource rent and geopolitical risk influence political instability in Ghana. First, we examine long‐run effects using linear methods. Second, we employ nonparametric methods to investigate the nonlinear link between natural resource rent and political instability as well as between geopolitical risk and political instability.MethodsThe study applied linear methods and nonparametric methods to historical time series data dating from the period of 1824–2020.ResultsThe results from the linear methods show that the interaction of natural resource rent and geopolitical risk exerts a positive and larger impact on political instability compared to their separate effects. The results from the nonparametric methods show a weak nonlinear link between these variables (i.e., natural resource rent, geopolitical risk, and political instability), although consistent with the linear long‐run results, the links are positive.ConclusionOverall, the results demonstrate that the observed positive relationship between natural resource rent and political instability is not just a recent phenomenon but holds for over more than 100 years in Ghana. Therefore, to attain a stable political environment, both long‐ and short‐term policies on political stability should be formulated.

Student experiences in agile stand-up meetings

PurposeThis purpose of this descriptive case study is to examine students’ experience engaging in stand-up meetings during the team project for the application development course in their Management Information Systems (MIS) program. Although the body of research on agile stand-up meetings is growing, there is little research on the experience of students who are engaging in stand-up meetings. The majority of research focuses on business professionals instead of students.Design/methodology/approachThis study uses a mixed methods approach to collect data by anonymously surveying students. This exploratory study is a prelude to implementing a larger-scale investigation of student perceptions of stand-up meetings. The research was conducted using a mixed methods approach that used a survey instrument with both open-ended and closed-ended questions to gather students’ perceptions. The qualitative data was analyzed using a thematic coding approach.FindingsThe results of this study demonstrate that students’ experiences with stand-up meetings are overwhelmingly positive, with students describing how stand-up meetings helped them communicate and collaborate with their team and solve problems together as a team. The majority of students in this study reported that participating in stand-up meetings helped them overcome roadblocks.Research limitations/implicationsThe main limitation of this descriptive case study is the sample size, since only one section of the course was available during the spring semester for the survey. Consequently, the findings may not be broadly generalizable to other contexts. An additional limitation is that the sample was obtained from a school primarily serving nontraditional adult students from underserved groups. One other limitation of this study is that the course surveyed was a synchronous online section with a limited amount of time for class sessions.Practical implicationsThis case study should serve as a starting point for faculty, particularly information systems faculty, who are seeking to incorporate stand-up meetings into their courses. The benefits that students cited were clear. As one student stated, stand-up “allows us to vet through our work, help build interpersonal relationships and strengthen our skills.” The larger impact and contribution of this research is that encourages faculty to adopt the practice of stand-up meetings to enhance students’ communication, collaboration and problem solving.Social implicationsIncorporating stand-up meetings into coursework benefits students by fostering collaboration, communication and problem-solving. The results of this study demonstrate that students’ experiences with stand-up meetings are overwhelmingly positive, with students describing how stand-up meetings helped them communicate and collaborate with their team and solve problems together as a team. The majority of students in this study reported that participating in stand-up meetings helped them overcome roadblocks.Originality/valueThis descriptive case study examines students’ experience engaging in stand-up meetings during the team project for the application development course in their MIS program. Although the body of research on agile stand-up meetings is growing, there is little research on the experience of students who are engaging in stand-up meetings. The majority of research focuses on business professionals instead of students.

Impact of ambient temperature on light-duty gasoline vehicle fuel consumption under real-world driving conditions

The widening gap between real-world vehicle energy consumption and modeled predictions can be attributed to discrepancies between actual ambient temperatures and assumptions made in laboratory tests. This study collected a detailed, extensive dataset comprising 25,640,666 records of real-world vehicle operating (speed, acceleration, etc.) and fuel consumption data alongside 124,938 hourly meteorological profiles (temperature, relative humidity, etc.). High-resolution fuel consumption rates (FCRs) based on ambient temperature were developed, and adjustment factors were introduced based on ambient temperature and vehicle specific power (VSP) binning. Fuel consumption factors (FCFs) were compared across different temperatures by incorporating VSP distributions and the adjusted FCRs, revealing larger FCFs at extreme temperatures compared to moderate ones. Fuel consumption inventories, both with and without temperature adjustments, were evaluated. The results indicated a 6% underestimation of annual fuel consumption in Beijing when disregarding temperature adjustments. The variation was observed across months (in July and August, underestimations can reach 11%) and across VSP bins (larger impact in low VSP bins). The relationship between FCR and ambient temperature is similar to a quadratic curve, with the lowest consumption occurring at 10 °C–20 °C. The FCF adjustment factor does not vary across speed intervals in cold weather and remains stable at approximately 1.15 at −10 °C, but it drops from 1.25 to 1 as speed increases from 5 to 100 km/h in hot weather. This study underscores the importance of considering ambient temperature in vehicle energy consumption modeling and the necessity of temperature-adjusted approaches for accurate fuel consumption estimations.

Probabilistic assessment of postfire debris-flow inundation in response to forecast rainfall

Abstract. Communities downstream of burned steep lands face increases in debris-flow hazards due to fire effects on soil and vegetation. Rapid postfire hazard assessments have traditionally focused on quantifying spatial variations in debris-flow likelihood and volume in response to design rainstorms. However, a methodology that provides estimates of debris-flow inundation downstream of burned areas based on forecast rainfall would provide decision-makers with information that directly addresses the potential for downstream impacts. We introduce a framework that integrates a 24 h lead-time ensemble precipitation forecast with debris-flow likelihood, volume, and runout models to produce probabilistic maps of debris-flow inundation. We applied this framework to simulate debris-flow inundation associated with the 9 January 2018 debris-flow event in Montecito, California, USA. When the observed debris-flow volumes were used to drive the probabilistic forecast model, analysis of the simulated inundation probabilities demonstrates that the model is both reliable and sharp. In the fully predictive model, however, in which debris-flow likelihood and volume were computed from the atmospheric model ensemble's predictions of peak 15 min rainfall intensity, I15, the model generally under-forecasted the inundation area. The observed peak I15 lies in the upper tail of the atmospheric model ensemble spread; thus a large fraction of ensemble members forecast lower I15 than observed. Using these I15 values as input to the inundation model resulted in lower-than-observed flow volumes which translated into under-forecasting of the inundation area. Even so, approximately 94 % of the observed inundated area was forecast to have an inundation probability greater than 1 %, demonstrating that the observed extent of inundation was generally captured within the range of outcomes predicted by the model. Sensitivity analyses indicate that debris-flow volume and two parameters associated with debris-flow mobility exert significant influence on inundation predictions, but reducing uncertainty in postfire debris-flow volume predictions will have the largest impact on reducing inundation outcome uncertainty. This study represents a first step toward a near-real-time hazard assessment product that includes probabilistic estimates of debris-flow inundation and provides guidance for future improvements to this and similar model frameworks by identifying key sources of uncertainty.

Performance and economic study of a novel high-efficiency PEMFC vehicle thermal management system applied for cold conditions

This paper proposes three different heating management systems, sysse (self priming thermal management system), syslow (low temperature thermal management system), and syssp (split flow thermal management system), which are mainly composed of PEMFC and heat pump subsystems. Simulations were conducted to compare the comprehensive performance of these systems under cold startup and cold operating conditions, and analyzed the effect of different factors on these three system. The results show that under the influence of cell stack parameters, compared to sysse and syslow, the syssp has an average power consumption reduction of 29.95 % and 20.94 %, with a maximum power reduction of 31.46 % and 27.61 %, the average range power increases by 35.09 % and 23.58 %, with a maximum range power increase of 107.53 % and 75.57 %, the average COPPEMFC (Coefficient of Performance of heating Proton Exchange Membrane Fuel Cell) increases by 0.56 and 0.37. Under the influence of heat pump parameters, the evaporating temperature has a larger impact on the performance gains of the syssp, while condensing temperature has a greater effect on power consumption, range power, and COP variations. Compared to sysse and syslow, the syssp can recover costs as quickly as 3.12 and 3.68 years.

Urban exodus or suburbanisation? Medium-term COVID-19 pandemic impacts on internal migration in Japan

The COVID-19 pandemic has profoundly affected internal migration patterns worldwide. Most previous studies have reported on pandemic-induced changes in internal migration using data from 2020 and 2021. Therefore, little is known about the pandemic’s medium-term impact. To address this gap, this study investigated an annual series of migration patterns from 2019 to 2023 in Japan. At the municipal level, relationships between net migration rates and population density indicated that the urbanisation trend became weak in 2020, compared to that in 2019, and it was the weakest in 2021. The urbanisation degree became stronger in 2023, increasing to the level in 2020. Using annual inter-municipal migration flows, this study then investigated changes in migration flows to/from and within three major metropolitan areas (Tokyo, Nagoya, and Osaka). The changes in sizes of these flows and migration effectiveness index suggested that the pandemic had the largest impact in the Tokyo metropolitan area, among the three areas, and it stimulated intra-metropolitan migration as suburbanisation, rather than net out-migration as ‘urban exodus’, in Japan. The overall results indicated that the pandemic had the largest impact in 2021, which got smaller as the migration patterns recovered to the pre-pandemic ones in 2023.

Aggravated surface O3 pollution primarily driven by meteorological variations in China during the 2020 COVID-19 pandemic lockdown period

Abstract. Due to the lockdown during the COVID-19 pandemic in China from late January to early April in 2020, a significant reduction in primary air pollutants, as compared to the same time period in 2019, has been identified by satellite and ground observations. However, this reduction is in contrast with the increase of surface ozone (O3) concentration in many parts of China during the same period from 2019 to 2020. The reasons for this contrast are studied here from two perspectives: emission changes and inter-annual meteorological variations. Based on top-down constraints of nitrogen oxide (NOx) emissions from TROPOMI measurements and GEOS-Chem model simulations, our analysis reveals that NOx and volatile organic compound (VOC) emission reductions as well as meteorological variations lead to 8 %, −3 % and 1 % changes in O3 over North China, respectively. In South China, however, we find that meteorological variations cause ∼ 30 % increases in O3, which is much larger than −1 % and 2 % changes due to VOC and NOx emission reductions, respectively, and the overall O3 increase in the simulations is consistent with the surface observations. The higher temperature associated with the increase in solar radiation and the decreased relative humidity are the main reasons that led to the surface O3 increase in South China. Collectively, inter-annual meteorological variations had a larger impact than emission reductions on the aggravated surface O3 pollution in China during the lockdown period of the COVID-19 pandemic.

Cognitive stimulation in socioeconomically disadvantaged children with neurodevelopmental disorders: a case series.

Research shows how conditions in socio-economically disadvantaged environments can be a risk factor for children's cognitive development. Consequently, children with neurodevelopmental disorders growing up in such environments face a double challenge. This study analyzed the effect of a comprehensive cognitive stimulation program on 4 single case studies comprising children with neurodevelopmental disorders from Guatemala. A descriptive study was conducted, using a case series approach, consisting of four participants with neurodevelopmental disorders, and a neurotypical group of 126 children. Participants in the neurotypical group were randomly assigned to either a control or experimental reference group. Cognitive assessments were performed pre- and post-intervention for all participants. Children in the experimental group received a comprehensive cognitive stimulation program between assessments. Two participants with neurodevelopmental disorders also received the stimulation program while the other two children with neurodevelopmental disorders performed the same task as the control group, specifically, regular reading activities. The experimental group exhibited a significant improvement in executive functions (inhibition, flexibility, and planning). The two experimental group children with neurodevelopmental disorders exhibited improved social cognition, showing a larger improvement compared to neurotypical children in their group, as well as compared to the two control children. However, although the reading program improved the language skills of the neurotypical control group, the children with neurodevelopmental disorders did not show as much improvement. These results suggest that specialized interventions are beneficial for children from socio-economically disadvantaged backgrounds, but importantly, may have a larger impact on children with neurodevelopmental disorders.

An exploratory analysis of Early Adopters in education innovations

Purpose The purpose of this study is to gain a better understanding of the conditions and motivations that influence teachers to adopt innovations. Design/methodology/approach Using Diffusion of Innovation theory (Rogers, 2003) and Self-Determination theory (Ryan and Deci, 2017), data from two surveys (n = 568; n = 108) and qualitative follow-up interviews of Early Adopter teachers (n = 16) were triangulated to discern relationships among their identification as Early Adopters, satisfaction of their basic psychological needs (BPN) and their implementation of an educational innovation. Findings Early Adopters had a positive and statistically significant relationship with the implementation of the innovation. Satisfaction of teachers’ BPN had the largest impact on innovation. Research limitations/implications The findings are preliminary and based on a small sample size of teachers. Reliability of the measure of BPN was not as high as the standard, but it did have the largest impact on implementation. Additional studies should explore the connections among Early Adopter teacher motivation, leadership and the satisfaction of their BPN. Practical implications School leaders should leverage the influence of Early Adopters to support innovation, and they should provide additional time, training and resources to supports teachers’ BPN. Originality/value This study examines how to identify and support Early Adopter teachers as enablers of change within schools. We know of no other studies that have used both Diffusion of Innovation theory and Self-Determination theory to understand the motivations of Early Adopter teachers.

Multivariate signal-to-noise ratio as a metric for characterizing spectral computed tomography

Objective. With the introduction of spectral CT techniques into the clinic, the imaging capacities of CT were expanded to multiple energy levels. Due to a variety of factors, the acquired signal in spectral CT datasets is shared between these images. Conventional image quality metrics assume independence between images which is not preserved within spectral CT datasets, limiting their utility for characterizing energy selective images. The purpose of this work was to develop a metrology to characterize energy selective images by incorporating the shared information between images within a spectral CT dataset. Approach. The signal-to-noise ratio (SNR) was extended into a multivariate space where each image within a spectral CT dataset was treated as a separate information channel. The general definition was applied to the specific case of contrast to define a multivariate contrast-to-noise ratio (CNR). The matrix contained two types of terms: a conventional CNR term which characterized image quality within each image in the spectral CT dataset and covariance weighted CNR (Covar-CNR) which characterized the contrast in each image relative to the covariance between images. Experimental data from an investigational photon-counting CT scanner was used to demonstrate the insight of this metrology. A cylindrical water phantom containing vials of iodine and gadolinium (2, 4, and 8 mg ml−1) was imaged under conditions of variable tube current, tube voltage, and energy threshold. Two image series (threshold and bin images) containing two images each were defined based upon the contribution of photons to reconstructed images. Analysis of variance (ANOVA) was calculated between CNR terms and image acquisition variables. A multivariate regression was then fitted to experimental data. Main Results. Image type had a major difference on how Covar-CNR values were distributed. Bin images had a slightly higher mean and wider standard deviation (Covar-CNRlo: 3.38 ±17.25, Covar-CNRhi: 5.77 ± 30.64) compared to threshold images (Covar-CNRlo: 2.08 ±1.89, Covar-CNRhi: 3.45 ± 2.49) across all conditions. ANOVA found that each acquisition variable had a significant relationship with both Covar-CNR terms. The multivariate regression model suggested that material concentration had the largest impact on all CNR terms. Signficance. In this work, we described a theoretical framework to extend the SNR to a multivariate form that is able to characterize images independently and also provide insight regarding the relationship between images. Experimental data was used to demonstrate the insight that this metrology provides about image formation factors in spectral CT.

Paper fiber-reinforced polypropylene composites from nonwoven preforms: A study on compression molding optimization from a manufacturing perspective

This work optimizes compression molding manufacturing for wet-formed nonwoven paper and polypropylene fiber mats. A central composite designed experiment investigated the effects of fiber reinforcement concentration, compression molding temperature, pressure, and time on composite laminate performance. We assess the composites’ density, panel thickness, water uptake, flexural behavior, and Izod impact strength. Models predicted and optimized composite performance using objective function analysis with penalties applied for undesirable conditions, such as processing time or low reinforcement concentration. Paper fiber content has the largest impact on composite properties, followed by processing time, molding pressure, and temperature. Composite optimization depends on penalty conditions; low fiber content penalties favor low fiber content panels with short processing times, while high fiber content penalties favor high fiber content panels with long processing times. This work suggests that molding composites with a greater fraction of renewable feedstock requires a commensurate increase in processing intensity.

State-Based Evaluation of the Workforce Pipeline from Paramedic Program Enrollment to Agency Affiliation

Objectives The strength and stability of the paramedic workforce is dependent on the continual flow of EMS clinicians into the field. Workforce entry requires three distinct steps: program completion, certification attainment, and affiliation with an EMS agency. At each of these steps, future EMS clinicians may be lost to the workforce but the contribution of each is unknown. Our objective was to evaluate these inflection points using a state-based registry of EMS clinicians from their point of entry into the EMS education system to eventual EMS agency affiliation. Methods This is a retrospective cohort evaluation of paramedic students in the Commonwealth of Virginia. We included any student who enrolled in a paramedic program in 2017 or 2018. Data were provided by the Virginia Office of Emergency Medical Services, who tracks the development of EMS clinicians from the point of entry into an educational program through their affiliation with an EMS agency upon employment. Our primary outcomes include proportions of enrolled students who complete a program, graduating students who attain national/state certification, and nationally certified EMS clinicians who affiliate with an EMS agency. Proportions were calculated at each step and compared to the overall population of students enrolled. Results In 2017 and 2018, 775 and 603 students were enrolled in paramedic programs, respectively. Approximately a quarter of students did not complete their paramedic program (2017: 25% [192/775]; 2018: 28% [170/603]). Of those who graduated, the proportion of students not gaining certification was lower (2017: 11% [62/583]; 2018: 17% [75/433]). Of those who certified, those not affiliating was similarly low (2017: 15% [77/521]; 2018: 13% [46/358]). Evaluating the effect of each of these steps on the total entry into the workforce, nearly half of those who originally enrolled did not join the workforce through agency affiliation (2017: 43% [331/775]; 2018: 48% [291/603]). Conclusions There are multiple areas to enhance retention of potential EMS trainees from program enrollment to EMS agency affiliation. This analysis suggests that educational attrition has a larger impact on the availability of new paramedics than certification examinations or agency affiliation decisions, though is limited to a singular state evaluation.