Full-scale Evaluation Research Articles

Assessment of emerging metallic structures technologies through test and analysis of fuselage structure

In partnership with Arconic and Embraer, the Federal Aviation Administration (FAA) is assessing emerging metallic structures technologies (EMST) using the FAA’s Full-Scale Aircraft Structural Test Evaluation and Research facility. In this collaborative effort, full-scale fuselage panel test data will be obtained to assess the effect of EMST fuselage concepts on damage tolerance performance as compared to the current baseline aluminum fuselage structures located on the crown of a typical single-aisle aircraft forward of the wing. Several technologies will be considered in the scope of the project, including advanced aluminum–lithium alloys, selective reinforcement using fiber metal laminates, and advanced joining processes, such as friction stir welding. Data from this study will be used to verify improved weight and structural safety performance of EMST and to assess the adequacy of existing airworthiness standards and guidance needed for the implementation of arising technologies and their impact on future designs. Results from the first baseline panel test are presented in this paper and will be compared to future tests on advanced panels containing varying EMST to assess the damage-tolerance performance.

Protocol for a pilot randomised controlled trial of an educational programme for adults on chronic haemodialysis with fatigue (Fatigue-HD)

IntroductionFatigue is a pervasive symptom of end-stage renal disease (ESRD) that is associated with low quality of life, disability and mortality, and has been identified as a top research priority...

Evaluability assessment of \u201cgrowing healthy communities,\u201d a mini-grant program to improve access to healthy foods and places for physical activity

BackgroundMini-grants have been used to stimulate multisector collaboration in support of public health initiatives by funding non-traditional partners, such as economic development organizations. Such mini-grants have the potential to increase access to healthy foods and places for physical activity through built environment change, especially in small and rural towns in the United States. Although a promising practice, few mini-grant evaluations have been done. Therefore, our purpose was to conduct an Evaluability Assessment (EA), which is a process that can help promising programs that lack evidence advance toward full-scale evaluation. Specifically, we conducted an Evaluability Assessment of a statewide mini-grant program, called “Growing Healthy Communities” (GHC), to determine if this program was ready for evaluation and identify any changes needed for future implementation and evaluation that could also inform similar programs.MethodsTelephone interviews with directors of six past mini-grant recipient organizations were conducted to assess implementation and evaluability. The six interviews were split equally among agencies receiving funding for food-oriented projects and physical activity-oriented projects. Within- and cross-case thematic analyses of interview transcripts were conducted.ResultsOrganizational capacity was a universal theme, reflecting other key themes (described in detail in the manuscript) that affected program implementation and evaluation, including collaboration, limited time and measurement integration. Conclusions. The EA process provided pilot data that suggest that other state, regional, and national funders should provide centralized assistance for data collection and evaluation from the outset of a mini-grant award program.

Mono and multi-modal biometric systems assessment by a common black box testing framework

Abstract As a trending method for the authentication, biometrics tends to be integrated in various devices, and in particular in smartphones. If the evaluation is performed on operational device, the biometric sample and algorithm are not reachable by the assessors. So, these latter have to perform an evaluation on a system considered as a black box. This kind of evaluation implies numerous manual comparison. This paper proposes a methodology to perform an evaluation of biometric black boxes. In order to obtain this methodology, two experiments were performed in order to determine an optimized conduct. Nevertheless, these experiments were realized with small test population, in order to assess the methodology a full scale evaluation was performed. This paper describes the used methodology to perform evaluation on black boxes systems, and the results obtained on the systems under test.

Intervening in the Lives of Gang Members in Denver: A Pilot Evaluation of the Gang Reduction Initiative of Denver

There are over one million gang members in the United States, but effective practices and programs to facilitate disengagement from gangs are rare. This first aim of this article was to introduce the intervention strategy of the Gang Reduction Initiative of Denver (GRID), a public agency operating at the core of a network of partners seeking to reduce gang violence in Denver. GRID uses a multidisciplinary team approach with coordinated and individualized case management and street outreach workers to facilitate disengagement from gangs and desistance from crime. The second aim of this article was to report the results of a pilot project evaluation, which entailed baseline interviews with 57 clients and follow-up interviews with 20 clients. Reductions in gang status, gang embeddedness, and offending were observed, as well as positive client–outreach relationships. The final aim was to report the steps toward establishing a foundation to conduct a full-scale evaluation. Most responses to gangs are considered promising because they have not been subject to rigorous evaluation. GRID aims to stand in contrast to most of the current inventory of justice evaluations of gang interventions through a process and impact evaluation consisting of random assignment to treatment and control groups.

Do conditional cash transfers reduce household vulnerability? Evidence from PROGRESA-Oportunidades in the 2000s

Abstract A number of researchers and policymakers have revealed the short- and medium-term impacts of conditional cash transfer (CCT) programs; however, accumulation of full-scale evaluations of their long-term impact is ongoing. To contribute to filling the gap, this study empirically examines the vulnerability of rural households in Mexico and how CCT has recently impacted them. Using two Mexican rural household panel datasets from the 2000s, I adopt Kurosaki’s (2006) version of Townsend’s (1994) risk-sharing model with instrumental variable methods, which enables a greater focus on household welfare decline. The empirical results confirm that CCT played a certain role in reducing household vulnerability in the 2000s; however considering the situation after the global crisis in 2008 and the exact mechanism through which this occurs remains subject to further examination.

Mindfulness intervention for foundation year doctors: a feasibility study

BackgroundMindfulness has been shown to reduce stress and burnout in medical students and healthcare professionals. This is a quality improvement study which assessed the feasibility of conducting a full-scale evaluation of a mindfulness intervention among UK foundation doctors to reduce stress and burnout.MethodsThis is an uncontrolled before and after study taking place in a single university teaching hospital. The RE-AIM framework which comprises of five dimensions including Reach, Adoption, Effectiveness, Implementation, and Maintenance was used to guide this assessment. The intervention was a 6-week ‘Mindfulness in the Workplace’ course. The primary measure was change in self-reported levels of stress immediately before and after the course. Additional measures explored the subjective experiences of participating doctors through the use of questionnaires handed out before and after the course.ResultsAll 20 places on the course were filled from the population of 108 foundation doctors at the trust with an equal number of foundation year 1 (n = 10) and foundation year 2 (n = 10) doctors. Sixteen participants (80%) attended one or more sessions. The median baseline stress score of the participants was 6.5 (range = 2 to 9). The median post-course stress score was 5.0 (range = 2 to 8). The Mann-Witney test indicated that the stress levels of participants were significantly lower at the end of the course compared to baseline, U = 74.50, p = .04. Additional measures suggested that the intervention may be associated with some other potential promising benefits for doctors including greater wellbeing, improved working life, and more satisfactory relationships with patients. Implementation of this intervention requires further work at the institutional level because only 35% of participants completed the full intervention, the main barrier being work commitments.ConclusionThis is the first programme of research to evaluate the feasibility of trialling and implementing a modified ‘Mindfulness in the Workplace’ intervention for foundation junior doctors in the UK. Based on the findings from this study, we conclude that this intervention is promising but further modifications are required such as the use of validated outcome measures and improving delivery aspects before this intervention programme is trialled among foundation doctors in the UK.

Full-Scale Performance Evaluations of Innovative and Manufactured Sediment Barrier Practices

Sediment barriers (SB) are devices typically installed along the perimeters of construction sites to intercept, capture, and contain pollutant discharge. Effective SBs minimize sediment transportation off-site by temporarily impounding stormwater and facilitating sediment capture upstream of the installation. Full-scale experiments were conducted on common, innovative, and manufactured SB practices used within the construction industry to better understand their performance. These practices consisted of two manufactured silt fence systems, three sediment retention barrier practices, and three manufactured sediment barrier products. Installation details for each practice were analyzed and amendments made to provide the most effective installations. Test observations indicated that a major failure mode of innovative and manufactured SB practices was flow bypass due to undermining. Performance-based comparisons of sediment retention rates, maximum impoundment depths, effluent flow rates, and treatment efficiencies were determined for each practice. Longevity tests were also conducted to evaluate characteristic changes over iterative storm events. Overall performance evaluations indicate practices that achieve impoundment depths greater than 1 ft (0.3 m) have consistent sediment capture rates of at least 90%. More importantly, impoundment depths greater than 1.5 ft (0.46 m) do not facilitate improved sediment capture rates. These observations suggest that optimized sediment capture is achieved when a SB practice has an effective upstream impoundment depth between 1 and 1.5 ft (0.3 and 0.46 m). Additionally, impoundment depths within this optimal zone reduce impoundment surface turbidity up to 60% when compared with turbidity levels along the bottom of the impoundment.

Acceptability and Feasibility of Implementing Accelorometry-Based Activity Monitors and a Linked Web Portal in an Exercise Referral Scheme: Feasibility Randomized Controlled Trial.

BackgroundExercise referral schemes (ERSs) are recommended for patients with health conditions or risk factors. Evidence points to the initial effectiveness and cost-effectiveness of such schemes for increasing physical activity, but effects often diminish over time. Techniques such as goal setting, self-monitoring, and personalized feedback may support motivation for physical activity and maintenance of effects. Wearable technologies could provide an opportunity to integrate motivational techniques into exercise schemes. However, little is known about acceptability to exercise referral populations or implementation feasibility within exercise referral services.ObjectiveTo determine the feasibility and acceptability of implementing an activity-monitoring device within the Welsh National ERS to inform a decision on whether and how to proceed to an effectiveness trial.MethodsWe conducted a feasability randomized controlled trial with embedded mixed-methods process evaluation and an exploratory economic analysis. Adults (N=156) were randomized to intervention (plus usual practice; n=88) or usual practice only (n=68). Usual practice was a 16-week structured exercise program. The intervention group additionally received an accelerometry-based activity monitor (MyWellnessKey) and associated Web platform (MyWellnessCloud). The primary outcomes were predefined progression criteria assessing acceptability and feasibility of the intervention and proposed evaluation. Postal questionnaires were completed at baseline (time 0:T0), 16 weeks (T1), and 12 months after T0 (T2). Routine data were accessed at the same time-points. A subsample of intervention participants and scheme staff were interviewed following the initiation of intervention delivery and at T2.ResultsParticipants were on average aged 56.6 (SD 16.3) years and mostly female (101/156, 64.7%) and white (150/156, 96.2%). Only 2 of 5 progression criteria were met; recruitment and randomization methods were acceptable to participants, and contamination was low. However, recruitment and retention rates (11.3% and 67.3%, respectively) fell substantially short of target criteria (20% and 80%, respectively), and disproportionally recruited from the least deprived quintile. Only 57.4% of intervention participants reported receipt of the intervention (below the 80% progression threshold). Less than half reported the intervention to be acceptable at T2. Participant and staff interviews revealed barriers to intervention delivery and engagement related to the device design as well as context-specific technological challenges, all of which made it difficult to integrate the technology into the service. Routinely collected health economic measures had substantial missing data, suggesting that other methods for collecting these should be used in future.ConclusionsTo our knowledge, this is the first study to evaluate short- and long-term feasibility and acceptability of integrating wearable technologies into community-based ERSs. The findings highlight device- and context-specific barriers to doing this in routine practice, with typical exercise referral populations. Key criteria for progression to a full-scale evaluation were not met.Trial RegistrationISRCTN Registry ISRCTN85785652; http://www.isrctn.com/ISRCTN85785652

Neuroendocrine tumor mixed with adenoma in rectum: a case report and literature review

Neuroendocrine tumor (NET) mixed with adenoma in rectum is rare. A 63-year-old man with a rectal adenoma underwent endoscopic submucosal dissection. A 3.2 cm neoplasm was dissected, which histologically corresponded to a villous adenoma with high-grade intraepithelial neoplasia. More interestingly, cells arranged in strip were found in the submucosa, with SyN(+) and CgA(−) in immunohistochemical staining, which were correspond to an NET. Although mixed adenoma with NET is rare, but we should alert it especially in large adenoma and full-scale preoperative evaluation should be taken before endoscopic operation.

Development of guidance for feasibility studies to decide whether and how to proceed to full-scale evaluation of complex public health interventions: a systematic review

BackgroundThe importance of feasibility studies (also referred to as exploratory or pilot studies) for optimising complex public health interventions and evaluation designs before evaluating effectiveness is widely acknowledged. In a systematic review of guidance on feasibility studies, we found that guidance is lacking or inconsistent on many aspects of their purpose, design, and conduct, and that it is lacking on the evidence needed to inform decisions about when to proceed to an effectiveness study. This work, building on that review, aimed to develop guidance for researchers, peer reviewers, and funders. MethodsThe systematic review was followed by a three-round web-based, Delphi exercise. We identified novel approaches to intervention optimisation and study designs from beyond public health through a scoping review and qualitative interviews with 15 experts in intervention design and evaluation. We discussed key aspects of the draft guidance with evaluation design specialists, funders, and journal editors in a consensus workshop (n=30), and we revised the guidance accordingly. The review is registered with PROSPERO, number CRD42016047843. FindingsOur systematic review had identified 25 unique sets of guidance. The Delphi identified consensus on many aspects of feasibility study methodology, but disagreement on others, including terminology, how feasibility study data can inform decisions about sample size, how progression criteria should be set, and how progression decisions should be made. A number of study designs typically used in clinical studies (eg, n of 1), digital health (eg, A–B testing), and engineering (eg, fractional factorial designs) have the potential to be applied more widely in feasibility studies of complex public health interventions—for example, to optimise interventions or to explore variation in intervention effects. InterpretationThe guidance will help researchers to develop and conduct feasibility studies, and take appropriate decisions on progression to an effectiveness study. It will provide peer reviewers and research funders with objective criteria against which to assess bids and publications. Study limitations include a lower response from less experienced researchers than from more experienced research methodologists in the Delphi exercise. The systematic review of guidance covered seven health-related bibliographic databases but might have missed guidance from other areas of social intervention research. FundingMedical Research Council (MRC)/National Institute of Health Research (NIHR) Methodology Research Panel (MR/N015843/1).

Too complex to test? Using exploratory trials to identify relevant contexts and mechanisms prior to larger scale evaluations

Introduction : Designing appropriate studies for evaluating complex interventions, like eHealth solutions to support integrated care, remains a methodological challenge. Although randomized control trials RCTs persist as the gold standard, they may not always be appropriate. Identification of contexts and mechanisms that can influence outcomes of an intervention typical in realist evaluations can help to identify appropriate methods for subsequent evaluation studies. Exploratory trials can be used to uncover these determinants, occurring at macro policy/system, meso organizational/team and micro person/provider levels in complex interventions prior to designing a full evaluation plan. Methods : An exploratory trial of the electronic Patient Reported Outcome ePRO tool was conducted to uncover contexts, mechanisms and relevant outcomes prior to full-scale evaluation. ePRO is a mobile application and portal designed to support goal-oriented care in inter-disciplinary primary health care practices. The four month trial was conducted in two practices in Toronto, Canada. Patients were randomized into control and intervention groups and compared pre and post on outcome measures quality of life and activation. Semi-structured interviews were conducted with providers and patients in the intervention group to capture relevant contexts, mechanisms and outcomes. Results : Eight providers and 16 patients 7-control, 9-intervention participated in the study. Outcomes were captured using the AQoL-4D and PAM surveys; analyzed using descriptive statistics. Interview transcripts were analyzed using interpretive descriptive methods. There was little change in outcome measures, with a high baseline, suggesting patients were higher-functioning than anticipated. Qualitative data highlighted factors for study consideration. Micro level factors included: participant characteristics, comfort with technology, training, and patient-provider relationship. Meso level factors included: provider workflows and norms, and organizational resources and culture. Macro level factors included: the technology policy environment, and system structure. Notably the research context and processes themselves were also influential. Enabling mechanisms occurred mainly at the micro level around motivation and readiness to set goals, and feelings regarding technology. Discussion : Multiple contextual variables and mechanisms were found to be potentially influential on study outcomes. Identifying relevant theories has been suggested as a way to address context and mechanisms in large scale control studies. In the ePRO example, we see the potential for dozens of potentially relevant theories ranging from individual level behaviour change theories, to organizational level innovation adoption theories. Conclusion : The number of complex, overlapping influencing variables suggests that complex interventions like ePRO may not be well suited to controlled evaluation designs. Realist, mixed-methods, and case studies which adopt ethnographic and narratives approaches may be more appropriate. Lessons Learned : Context variables and mechanisms can occur at multiple levels and may change over time of the intervention. Limitations : Although our analysis methods were informed by realist approaches, the study was not set up as a realist evaluation. Opportunities for observation and follow-up that would have allowed for more in-depth exploration may have been missed. Suggestions for future research : Studies of complex interventions, liked eHealth enabled models of integrated care, should consider alternatives to RCT approaches when “controlling” all relevant variables is unlikely. A case-study ethnographic approach will be taken as part of the next phase of ePRO evaluation.

Full-scale evaluation of SO2 capture increase for semi-dry FGD technology

This paper reports on a full-scale investigation of a possible increase of the SO2 capture ratio in current semi-dry flue gas desulphurization (FGD) technology. The FGD unit is used for two 130 t/h steam PC boilers burning a blend of lignite and hard coal with dry ash-free sulphur content at 1.83%. The FGD unit has been designed to reach an SO2 emission limit of 1350 mg/Nm3. The aim of the experimental work presented in this paper was to investigate the possibility of reaching SO2 emission targets of 500 and 200 mg/Nm3. The investigation sought to determine the real correlation of SO2 capture ratio with Ca/S and with the difference of dry-bulb temperature and dew point in the absorber ΔtAD. Generally, the SO2 capture correlation with Ca/S has flat characteristics at a capture ratio >90%, which is required to reach the 200 mg/Nm3 target. In this case, lowering the ΔtAD in the absorber has only a weak effect. The 500 mg/Nm3 target requires an SO2 capture ratio of about 80%; in this case lowering the ΔtAD by about 7 °C increases the SO2 capture by 10% points at the same Ca/S ratio.

Recovery of phosphorus and nitrogen from human urine by struvite precipitation, air stripping and acid scrubbing: A pilot study

Sustainable and closed-loop nutrient cycling require the recovery of valuable resources from wastewater. Resource recovery from diluted wastewater streams is limited by diluted concentrations and unfavorable reaction kinetics. In comparison, source separated urine allows resource recovery from a highly concentrated nutrient stream, resulting in a more sustainable and efficient recovery practice. Different nutrient recovery methods from urine have been studied in lab-scale, but pilot or full-scale process evaluations remain sparse. In this study, recovery of struvite and ammonium sulfate from urine of pregnant women was demonstrated at a pilot-scale treatment facility by means of precipitation and air stripping/acid scrubbing. The system achieved 94% struvite precipitation efficiency but merely 55% of the crystals were removed and recovered. The low phosphorus recovery was due to the washout of small crystals that escaped the sieve and settling tank, hence requiring an improved method for crystals capture. The removal and recovery efficiencies for nitrogen were 93% and 85%, respectively. Composition analysis of the produced fertilizers indicated that struvite was the dominated precipitate and quality of the ammonium sulfate met European standards. Carbamazepine and diclofenac were added in the urine to measure the fate of pharmaceuticals in the treatment system. Very little of the spiked pharmaceuticals (<0.01%) accumulated in the produced struvite and ammonium sulfate. The overall energy demand of the pilot system was 1066 MJ per m3 urine processed or 198 MJ per kg N removed. Energy efficiency was not optimized and can be improved in many ways.

Performance of a novel real-time respirator seal integrity monitor on firefighters: Simulated workplace pilot study

Millions of workers, including firefighters, use respiratory protective device. The key aspect in assuring the intended protection level of a respirator is its fit. However, even if the respirator originally fits well, the faceseal may be breached during its use. Until now, there have been no practically viable, inexpensive means to monitor the performance of a respirator during actual use. A novel Respirator Seal Integrity Monitor (ReSIM) was developed and recently evaluated on manikins by our team. The objective of this study was to evaluate the ReSIM effectiveness on respirator-wearing firefighters exposed to aerosols while performing simulated routine operational activities. Initially, 15 subjects were recruited for the study. Following a preliminary investigation that resulted in modifications in the ReSIM prototype and testing protocol, a subset of nine firefighters was chosen for a full-scale evaluation. The testing was conducted in a 24.3-m3 exposure chamber using NaCl as the challenge aerosol. Controlled faceseal leaks were established by opening a solenoid valve for 10, 15, or 20 sec. Leaks were also established as the tested firefighter slightly repositioned the respirator on his/her face. During the testing, the ReSIM measured particles inside a full-face elastomeric respirator with a 72.7% leak detection sensitivity (probability of correct leak identification) and an 84.2% specificity (probability of correct identification of the intervals which are absent of any leak). After adjusting for false negatives and persistent false positives, sensitivity and specificity increased to 83.6% and 92.2%, respectively. The factors causing minor limitations in leak detection sensitivity and specificity can be attributed to variability among subjects, moisture’s effect on the particle sensor, and some in-mask sampling bias. In conclusion, the ReSIM can promptly detect the breach in a respirator faceseal with high sensitivity and specificity. Due to its capability to alert the wearer of possible overexposure to hazardous aerosols, the ReSIM concept has a remarkable potential to be applied in various working environments, where respirators are used.

Effectiveness of a neutral electrolysed oxidising water (NEOW) device in reducing Legionella pneumophila in a water distribution system: A comparison between culture, qPCR and PMA-qPCR detection methods

Disinfection of hot water systems is critical for reducing Legionnaires’ disease in high-risk buildings. The use of neutral electrolysed oxidising water (NEOW) is a promising method for the control of microorganisms in hot water systems. However, full-scale evaluations of the efficacy of NEOW devices to control Legionella pneumophila are currently lacking. The aim of this study was to assess the effectiveness of a NEOW device in reducing L. pneumophila in a hotel water network.Water samples (n = 67) were collected from different sites of a hotel distribution system before and after the installation of the NEOW device at the 1st, 4th, 8th and 12th week. Detection of L. pneumophila was performed comparing culture, qPCR and PMA-qPCR methods. Total bacterial counts (22 °C and 37 °C), Pseudomonas spp. and physico-chemical parameters were also monitored.The NEOW treatment resulted in a reduction of the amount of L. pneumophila positive samples (−32%) and of the number of heavily contaminated points (>104 CFU/L and >103 CFU/L) (−100% and −96%, respectively). Treatment maintained L. pneumophila at low levels (<102 CFU/L), which do not require specific intervention measures. The effectiveness of the disinfection system was also confirmed by PMA-qPCR (p < 0.001). The use of PMA resulted in a signal decrease in almost all samples upon the disinfection treatment.The NEOW disinfection device appears to be a promising approach to reduce the colonisation of hot water systems by L. pneumophila; however, further investigations are needed to ascertain its efficiency over longer time periods.

Assessment of Equivalent Thickness Design Principles for Geosynthetic Reinforced Pavements by Way of Accelerated Testing

The Engineer Research and Development Center (ERDC) of the U.S. Army Corps of Engineers has performed multiple laboratory and full-scale evaluations of geosynthetic reinforced pavements. One result from early geosynthetic reinforced pavement evaluations was a pavement design methodology implemented in ETL 1110-1-189: Use of Geogrids in Pavement Construction. Since that time, the evaluations have been primarily focused on comparing performance between varying types of geosynthetic products. While the studies have independently compared the discrete performance of single geosynthetic reinforced sections to unreinforced sections, a comprehensive analysis of available data has not been performed to validate or refine the implemented design methodology. The objective of this effort was to assemble available data from laboratory and full-scale testing conducted at ERDC for the primary purpose of assessing the flexible pavement design methodology presented in ETL 1110-1-189. Simplifying assumptions were made to allow comparison of varying loading and pavement structure conditions. This assessment found that the combined dataset supports the original design curve produced with the equivalent thickness methodology described in ETL 1110-1-189. The updated dataset would reduce the equivalent reinforced thickness by approximately 1.0-inches (25.4 mm) at unreinforced thicknesses less than 14 inches (356 mm), providing a slightly more conservative result. The adjusted data converged with the original equivalency chart at an unreinforced thickness of approximately 16 inches (406 mm).

Fatigue performance of asphalt mixture containing recycled materials and warm-mix technologies under accelerated loading and four point bending beam test

Using high contents of reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) in pavement constructions has gained significant popularity in the recent years as a viable solution to cleaner paving material productions. The objective of this study was to evaluate fatigue cracking resistance of RAP and RAS containing asphalt paving mixtures by a bench-scale test and a full-scale test. A flexural beam fatigue test method was used for the bench-scale evaluation, while the accelerated loading facility (ALF) experimental data, obtained by the federal highway administration (FHWA) since 2013, provided the full-scale evaluation. A total of ten plant produced asphalt mixtures used for ten full-scale test lanes were collected at the time of construction and recently prepared as beam specimens for the four-point bending beam fatigue test. Two performance grades asphalt binders (PG 64-22 and PG 58-28) were used with a conventional hot-mix and two warm-mix (foaming and chemical additive) production processes. Beam fatigue tests were conducted by applying strain-controlled repeated sine waves until the beam failure occurs at 50% of the initial stiffness (Si), which were then used to evaluate the fatigue resistance of the ten mixtures. Beam fatigue and ALF test results indicated that an increase in recycled binder ratio (RBR) results in a reduced fatigue life. Use of RAS appeared to reduce the fatigue life of ALF test lane by 65%, but reduced the mixture fatigue life by only 2.3%. Using softer asphalt binder (PG58-28) improved the fatigue life of asphalt mixtures and pavements with 40% RAP, but did not improve as much when used with 20% RAS. Using the foaming warm mix asphalt (WMA) process improved the fatigue life of asphalt mixtures and pavements when used with 20% RAP. However, when used with 40% RAP, this benefit of the foaming WMA process may be reduced. The chemical WMA binder additive (Evotherm) generally did not improve the fatigue life of asphalt mixtures and pavements.

Full-Scale Performance Evaluations of Various Wire-Backed Nonwoven Silt Fence Installation Configurations

Silt fences have long been a key component for controlling construction stormwater runoff; nonetheless, many silt fence installations fail to perform in the field as intended. Silt fences are temporary sediment control measures used to retain sediment by impounding runoff and allowing for sedimentation on-site, while simultaneously discharging stormwater runoff at a controlled rate. This study evaluated the performance of eight alternative configurations of the Alabama Department of Transportation (ALDOT) standard wire-backed, nonwoven silt fence. Standard installation parameters associated with the ALDOT silt fence include (1) 32-in. (81.3-cm) high fence, (2) 0.95 lb/ft (1.4 kg/m) support T-post, and (3) 10 ft (3.0 m) T-post spacing. Throughout the series of configurations tested, these standard parameters were varied individually and jointly in efforts to improve overall performance. Variations to the standard parameters include (1) 24-in. (61.0-cm) high fence, (2) 1.25 lb/ft (1.9 kg/m) support T-post, (3) 5 ft (1.5 m) T-post spacing, and (4) trench offsetting. Performance analyses were conducted on each configuration and results were evaluated to determine the best overall configuration to enhance the in-field performance of the ALDOT silt fence. Ultimately, the offset 24 in. (61.0 cm) fence with 1.25 lb/ft (1.9 kg/m) T-post spaced 5 ft (1.5 m) on-center resulted in the best overall improvement, retaining an average of 93% of sediment and deflection of only 0.18 ft (0.004 m) over the course of three simulated storm events.

Preventing stress-related ill health among newly registered nurses by supporting engagement in proactive behaviors: development and feasibility testing of a behavior change intervention

BackgroundTransitioning into a new professional role is a stressful experience with consequences for mental and physical health, job satisfaction, organizational commitment, and turnover. New registered nurses seem to be at particular risk of developing stress-related ill health during their first years in the profession. Previous research indicates that engagement in proactive behaviors may reduce this risk.MethodsWith the work presented in this paper, we aimed to test the feasibility of conducting an evaluation of the effect of a behavior change intervention to prevent stress-related ill health among new registered nurses by supporting their engagement in proactive behaviors. Feasibility objectives included recruitment, randomization, data collection and analysis, participation, acceptability, and deliverability.We tested the feasibility of evaluating the effect of the intervention as part of a transition-to-practice program for new registered nurses using a non-randomized design with one condition. The trial included a sample of 65 new registered nurses who had been working for 6 months or less.ResultsThe feasibility of conducting a full-scale effect evaluation was confirmed for recruitment, data collection and analysis, participation, and acceptability. It was not possible to randomize participants, but analyses of between-group differences revealed no selection bias. The time of the intervention will need to be extended to ensure the deliverability.ConclusionWith some adjustments in the study design, it is feasible to evaluate the effect of a behavior change intervention to support new registered nurses’ engagement in proactive behaviors during their transition into the new profession as part of a transition-to-practice program for new nurses.