bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantification of Vapor Intrusion Pathways: An Integration of Modeling and Site Characterization
Authors: Akbariyeh Simin , Patterson Bradley M. , Kumar Manish , Li Yusong 
Published: September 2016

Core Ideas
A numerical model was developed based on comprehensive field site characterization.
Modeling results and field measurements were comprehensively compared.
Soil anisotropic property could significantly influence vapor intrusion pathways.
Vapor intrusion was highly dependent on oxygen availability.
Vapor intrusion of volatile organic compounds into buildings can be a significant source of human exposure to hazardous materials. Field assessment is essential to evaluate the vapor intrusion pathways, which can be challenging due to uncontrolled site environments. Mathematical modeling is expected to play significant roles to predict indoor air contaminant concentration and to provide guidance for vapor intrusion management. Efforts on field assessment and mathematical modeling, however, are not well integrated in current vapor intrusion management practice. This work seeks to quantify vapor intrusion pathways into a slab‐on‐ground building by integrating mathematical modeling with well‐controlled field measurements under three different pressure and ventilation site conditions. Mechanisms controlling vapor intrusion pathways were identified through systematic comparisons between modeled and measured indoor air concentration, contaminant and oxygen distribution profiles beneath the building, and diffusive and advective flux under different pressure and air ventilation conditions. Enhanced horizontal oxygen movement was found to be critical to evaluate vapor intrusion pathways, which can be attributed to the soil anisotropic properties in combination with vertical penetration of oxygen from slab. The dependency of oxygen concentration in the biodegradation modeling was found to be very important to describe the biodegradation of volatile hydrocarbons.
Geochemical Recharge Estimation and the Effects of a Declining Water Table
Authors: Katz Britney S. , Stotler Randy L. , Hirmas Daniel , Ludvigson Greg , Smith Jon J. , Whittemore Donald O. 
Published: September 2016

Core Ideas
Intensive groundwater development has led to steep water‐level declines.
Geochemically, vadose zone water in drained zone is identical to groundwater.
Geochemical estimates of recharge rates not possible through this drained zone.
With steep water‐level declines, care is needed for geochemical recharge estimates.
In this area, focused recharge likely dominates over diffuse recharge.
The High Plains aquifer (HPA) is one of the largest aquifers in the world and is critical for agricultural production in the United States. In Kansas, irrigation using the HPA has resulted in steep groundwater declines. Unexpected water‐level response to pumping recovery in the northwestern Kansas portion of the HPA was recently observed, indicating a previously unknown source of recharge. The goal of this research was to investigate water movement and vadose zone chemical inventories to constrain recharge pathways and rates to the aquifer. Detailed geochemical profiles at a cored site indicated displaced chloride, bromide, nitrate–nitrogen (NO3–N), and sulfate reservoirs—likely mobilized by the onset of on‐site irrigation—believed to have commenced in 1984. Water in the vadose zone beneath the predevelopment water table (36–63 m below ground surface) is remnant groundwater left as the water table declined. Thus, assumptions of a chloride mass balance are not valid in this zone. These results indicate irrigation return flow has yet to travel through the vadose zone to recharge the aquifer at this location. Calculated chemical transit times through the profile to the predevelopment water table exceed the start of irrigation at the site, and groundwater radiocarbon ages on the order of 3000 yr BP provide further evidence against substantial irrigation return to the aquifer. These data establish evidence for complicated flow paths through the vadose zone to the aquifer and argue against broad, diffuse recharge to the aquifer. Future studies in the area should investigate focused recharge pathways to identify recharge sources.
Synthesis of an oxidation-resistant SiC coating on graphite and modeling analysis with thermodynamics calculations
Authors: Pourasad Jalil , Ehsani Naser 
Published: September 2016

AbstractA graded SiC coating was prepared on a graphite substrate by a pack cementation technique at 1 873 K to improve the oxidation resistance. The HSC Chemistry software was used for thermodynamics calculations. The coating was characterized by means of X-ray diffraction and scanning electron microscopy. Isothermal oxidation testing of the samples was performed at 1 773 K in air. The modeling analysis indicated that aluminum oxide can be reduced and an SiC coating can be formed due to the reaction of silicon with CO and carbon with SiO. The growth of the SiC nanofibers was attributed to the gaseous reaction of SiO with CO. A 600 μm thick SiC layer can be observed at the graphite–coating interface. The simulation and experimental results were consistent with each other. The mass loss of the SiC coated sample was 1.1 % after oxidation for 10 h, whereas the graphite was fully oxidized after 1 h.
Investigation of mechanical properties of tubular aluminum foams
Authors: Uzun Arif , Karakoc Halil , Gokmen Ugur , Cinici Hanifi , Turker Mehmet 
Published: September 2016

Abstract
This manuscript focuses on the mechanical behavior under compressive and bending loadings of tubular aluminum foams. The tubular structures were manufactured using the powder metallurgy technique. Tubular aluminum foams were fabricated by heating foamable precursor materials above their melting temperature in a mould. The influence of important parameters such as wall thickness and density of foam on the mechanical properties was investigated. It was found that the 6 mm thick specimen showed a lower collapse strength than the thicker 9 mm specimen. Despite the decrease in densities of the samples, the collapse strength increased with the increase in wall thickness. The reduction of approximately 33% in wall thickness (from t = 9 mm to 6 mm) decreased the bending performance of the tubular aluminum foams by approximately 50%.
Chunky graphite formation in ductile cast irons: effect of silicon, carbon and rare earths
Authors: de la Torre Urko , Lacaze Jacques , Sertucha Jon 
Published: September 2016

AbstractUse of rare earths, high silicon and carbon contents, and low cooling rates are reported as possible reasons for formation of chunky graphite in ductile iron castings. The understanding of this graphite degeneration is however limited, and the above conclusions are still controversial. To get further insight into this topic, ductile cast iron melts have been prepared with various carbon and silicon contents and using nodularizing alloys with various rare earth levels. These melts have been cast in blocks with different sizes to include also the effect of cooling rate on graphite degeneration. Metallographic investigation revealed that the chunky-affected areas enlarge when decreasing the cooling rate, when increasing the silicon content and without low-level addition of rare earth. In the discussion, a schematic based on change of liquid/graphite interfacial energy with alloying elements is proposed which describes the conditions for the formation of chunky graphite instead of nodular graphite.
Association of Alternative Approaches to Normalizing Peritoneal Dialysis Clearance with Mortality and Technique Failure: A Retrospective Analysis Using the United States Renal Data System-Dialysis Morbidity and Mortality Study, Wave 2
Authors: Boyle Suzanne M. , Li Yimei , Wilson F. Perry , Glickman Joel D. , Feldman Harold I. 
Published: September 2016

Background Total body water (V) is an imprecise metric for normalization of dialytic urea clearance (Kt). This poses a risk of early mortality/technique failure (TF). We examined differences in the distribution of peritoneal Kt/V when V was calculated with actual weight (AW), ideal weight (IW), and adjusted weight (ADW). We also examined the associations of these Kt/V measurements, Kt/body surface area (BSA), and non-normalized Kt with mortality and TF. Methods This is a retrospective cohort study of 534 incident peritoneal dialysis (PD) patients from the Dialysis Morbidity and Mortality Study Wave 2 linked with United States Renal Data System through 2010. Using Cox-proportional hazard models, we examined the relationship of several normalization strategies for peritoneal urea clearance, including Kt/VAW, Kt/VIW, Kt/VADW, Kt/BSA, and non-normalized Kt, with the outcomes of mortality and TF. Harrell's c-statistics were used to assess the relative predictive ability of clearance metrics for mortality and TF. The distributions of Kt/VAW, KT/VIW, and KT/VADW were compared within and between body mass index (BMI) strata. Results Median patient age: 59 (54% male; 72% white; 91% continuous ambulatory PD [CAPD]). Median 24-hour urine volume: 700 mL; median estimated glomerular filtration rate (eGFR) at initiation: 7.15 mL/min/1.73 m2. Technique failure and transplant-censored mortality at 5 years: 37%. Death and transplant-censored TF at 5 years: 60%. There were no significant differences in initial eGFR and 24-hour urine volume across BMI strata. There were statistically significant differences in each Kt/V calculation within the underweight, overweight, and obese strata. After adjustment, there were no significant differences in the hazard ratios (HRs) for TF/mortality for each clearance calculation. Harrell's c-statistics for mortality for each clearance calculation were 0.78, and for TF, 0.60 – 0.61. Conclusions Peritoneal urea clearances are sensitive to subtle changes in the estimation of V. However, there were no detectable significant associations of Kt/VAW, Kt/VIW, Kt/VADW, Kt/BSA, or Kt with TF or mortality.
The Phantom of Metformin-Induced Lactic Acidosis in End-Stage Renal Disease Patients: Time to Reconsider with Peritoneal Dialysis Treatment
Authors: Al-Hwiesh Abdullah K. , Abdul-Rahman Ibrahiem Saeed , Noor Abdul-Salam , Nasr-El-Deen Mohammed A. , Abdelrahman Abdalla , El-Salamoni Tamer S. , Al-Muhanna Fahd A. , Al-Otaibi Khalid , Al-Audah Nehad 
Published: September 2016

Objective Metformin continues to be the safest and most widely used antidiabetic drug. In spite of its well-known benefits; metformin use in end-stage renal disease (ESRD) patients is still restricted. Little has been reported about the effect of peritoneal dialysis (PD) on metformin clearance and the phantom of lactic acidosis deprives ESRD patients from metformin therapeutic advantages. Peritoneal dialysis is probably a safeguard against lactic acidosis, and it is likely that using this drug would be feasible in this group of patients. Material and methods The study was conducted on 83 PD patients with type 2 diabetes mellitus. All patients were on automated PD (APD). Metformin was administered in a dose of 500 - 1,000 mg daily. Patients were monitored for glycemic control. Plasma lactic acid and plasma metformin levels were monitored on a scheduled basis. Peritoneal fluid metformin levels were measured. In addition, the relation between plasma metformin and plasma lactate was studied. Results Mean fasting blood sugar (FBS) was 10.9 ± 0.5 and 7.8 ± 0.7, and mean hemoglobin A1-C (HgA1C) was 8.2 ± 0.8 and 6.4 ± 1.1 at the beginning and end of the study, respectively (p < 0.001). The mean body mass index (BMI) was 29.1 ± 4.1 and 27.3 ± 4.5 at the beginning and at the end of the study, respectively (p < 0.001). The overall mean plasma lactate level across all blood samples was 1.44 ± 0.6. Plasma levels between 2 and 3 mmol/L were found in 11.8% and levels of 3 - 3.6 mmol/L in 2.4% plasma samples. Hyperlactemia (level > 2 and < 5 mmol/L) was not associated with overt acidemia. None of our patients had lactic acidosis (levels > 5 mmol/L). Age ≥ 60 was a predictor for hyperlactemia. No relationship was found between plasma metformin and lactate levels. Conclusion Metformin may be used with caution in a particular group of ESRD patients who are on APD. Metformin allows better diabetic control with significant reduction of BMI. Information on the relationship between metformin and plasma lactate levels is lacking. Peritoneal dialysis appears to be a safeguard against the development of lactic acidosis in this group of patients.
Psychosocial Factors Predict Nonadherence to PD Treatment: A Hong Kong Survey
Authors: Fung Timothy K. F. , Ng Yu Leung , Lam Man Fai , Lee Kelvin K. W. 
Published: September 2016

Background Nonadherence to hand hygiene and aseptic regimen, dialysis environment guidelines, and catheter and exit-site care guidelines are risk factors of peritonitis. However, little is known about the psychosocial factors that account for the nonadherent behavior of patients undergoing peritoneal dialysis (PD). Applying the health belief model, this study seeks to enhance the understanding of psychosocial influences on patients’ nonadherent behavior to the 3 regimen components. Methods Through referrals by 7 Hong Kong renal patient support groups, we surveyed patients undergoing PD treatment. Results A total of 244 Hong Kong PD patients completed the questionnaires. About 90% of the patients reported no deviation from catheter and exit-site care guidelines. However, the nonadherence rates of hand hygiene and aseptic regimen and of dialysis environment guidelines were 30.3% and 23%, respectively. Longer time on PD treatment and lower family monthly income were associated with nonadherence to dialysis environment guidelines. Employed patients tended toward nonadherence to catheter and exit-site care guidelines twice as much as unemployed patients. Of the 5 health beliefs, perceived benefits, perceived barriers, and efficacy belief were significant predictors of nonadherence to the 3 regimen components. Conclusions The findings of this study inform the design of intervention to change patients’ behavior in regimen nonadherence for preventing peritonitis. To identify the target audience for adherence intervention based on the 3 regimen components, the results suggest dividing patients into subgroups according to their sociodemographic background. To foster behavioral change, health communicators should address patients’ health beliefs when formulating intervention strategies.
Clinical Outcomes of Peritoneal Dialysis in End-Stage Renal Disease Patients with Liver Cirrhosis: A Propensity Score Matching Study
Authors: Lee Su Mi , Son Young Ki , Kim Seong Eun , An Won Suk 
Published: September 2016

Background Clinical results of long-term peritoneal dialysis (PD) therapy in patients with liver cirrhosis (LC) and end-stage renal disease (ESRD) are controversial. This study evaluated the clinical outcomes of LC patients undergoing PD. Methods Clinical records were retrospectively collected from a single center between January 2007 and December 2014. An analysis of PD patients with LC and without liver disease was performed using propensity score matching. We further restricted matching by age, gender, and the presence of diabetes mellitus. Two cohorts of 33 patients each were selected. Early technical complications were defined as the presence of catheter-related complications, including malposition, leakage, omental wrapping, obstruction, and requiring a transfer to hemodialysis (HD) within 6 months of initiating PD. Results Mean PD duration was lower in LC patients (57.2 ± 46.1 months) than in controls (85.8 ± 64.2 months). Blood urea nitrogen, creatinine, and albumin levels were significantly lower in LC patients than in the control group. Cystatin C and cystatin C-based glomerular filtration rates were not significantly different in the LC group compared with those in the controls. We found that the risks for early technical complications, peritonitis, and long-term PD and patient survival were not higher in patients with LC than in those without LC. Ascites were easily controlled, and hepatic encephalopathy did not affect PD maintenance in LC patients. Conclusions The clinical outcomes, including technical complications, peritonitis, and patients’ survival, suggest that PD can be used as a renal replacement therapy in ESRD patients with LC.
Introduction of Renal Key Performance Indicators Associated with Increased Uptake of Peritoneal Dialysis in a Publicly Funded Health Service
Authors: Toussaint Nigel D. , McMahon Lawrence P. , Dowling Gregory , Holt Stephen G. , Smith Gillian , Safe Maria , Knight Richard , Fair Kathleen , Linehan Leanne , Walker Rowan G. , Power David A. 
Published: September 2016

Background Increased demand for treatment of end-stage kidney disease has largely been accommodated by a costly increase in satellite hemodialysis (SHD) in most jurisdictions. In the Australian State of Victoria, a marked regional variation in the uptake of home-based dialysis suggests that use of home therapies could be increased as an alternative to SHD. An earlier strategy based solely on increased remuneration had failed to increase uptake of home therapies. Therefore, the public dialysis funder adopted the incidence and prevalence of home-based dialysis therapies as a key performance indicator (KPI) for its health services to encourage greater uptake of home therapies. Methods A KPI data collection and bench-marking program was established in 2012 by the Victorian Department of Health and Human Services, with data provided monthly by all renal units in Victoria using a purpose-designed website portal. A KPI Working Group was responsible for analyzing data each quarter and ensuring indicators remained accurate and relevant and each KPI had clear definitions and targets. We present a prospective, observational study of all dialysis patients in Victoria over a 4-year period following the introduction of the renal KPI program, with descriptive analyses to evaluate the proportion of patients using home therapies as well as home dialysis modality survival. Results Following the introduction of the KPI program, the net growth of dialysis patient numbers in Victoria remained stable over 4 years, at 75 – 80 per year (approximately 4%). However, unlike the previous decade, about 40% of this growth was through an increase in home dialysis, which was almost exclusively peritoneal dialysis (PD). The increase was identified particularly in the young (20 – 49) and the elderly (> 80). Disappointingly, however, 67% of these incident patients ceased PD within 2 years of commencement, 46% of whom transferred to SHD. Conclusions Introduction of a KPI program was associated with an increased uptake of PD but not home HD. This change in clinical practice restricted growth of SHD and reduced pressure on satellite services. The effect was offset by a modest PD technique survival. Many patients in whom PD was unsuccessful were subsequently transferred to SHD rather than home HD.
AMMONIA AND CO OUTFLOW AROUND 6.7 GHz METHANOL MASERS
Authors: Li F. C. , Xu Y. , Wu Y. W. , Yang J. , Lu D. R. , Menten K. M. , Henkel C. 
Published: September 2016

ABSTRACT
Single point observations are presented in NH3 (1, 1) and (2, 2) inversion transitions using the Effelsberg 100 m telescope for a sample of 100 6.7 GHz methanol masers and mapping observations in the 12CO and 13CO (1 − 0) transitions using the Purple Mountain Observatory Delingha 13.7 m telescope for 82 sample sources with detected ammonia. A further 62 sources were selected for either 12CO or 13CO line outflow identification, producing 45 outflow candidates, 29 using 12CO and 16 using 13CO data. Twenty-two of the outflow candidates were newly identified, and 23 had trigonometric parallax distances. Physical properties were derived from ammonia lines and CO outflow parameters were calculated. Histograms and statistical correlations for ammonia, CO outflow parameters, and 6.7 GHz methanol maser luminosities are also presented. No significant correlation was found between ammonia and maser luminosity. However, weak correlations were found between outflow properties and maser luminosities, which may indicate that outflows are physically associated with 6.7 GHz masers.
ELEMENT MASSES IN THE CRAB NEBULA
Authors: Sibley Adam R. , Katz Andrea M. , Satterfield Timothy J. , Vanderveer Steven J. , MacAlpine Gordon M. 
Published: September 2016

ABSTRACT
Using our previously published element abundance or mass-fraction distributions in the Crab Nebula, we derived actual mass distributions and estimates for overall nebular masses of hydrogen, helium, carbon, nitrogen, oxygen and sulfur. As with the previous work, computations were carried out for photoionization models involving constant hydrogen density and also constant nuclear density. In addition, employing new flux measurements for [Ni ii] λ7378, along with combined photoionization models and analytic computations, a nickel abundance distribution was mapped and a nebular stable nickel mass estimate was derived.
ON THE FEASIBILITY OF CHARACTERIZING FREE-FLOATING PLANETS WITH CURRENT AND FUTURE SPACE-BASED MICROLENSING SURVEYS
Authors: Henderson Calen B. , Shvartzvald Yossi 
Published: September 2016

ABSTRACT
Simultaneous space- and ground-based microlensing surveys, such as K2's Campaign 9 (K2C9) and WFIRST, facilitate measuring the masses and distances of free-floating planet (FFP) candidates, which are identified as single-lens events with timescales that are of the order of 1 day. Measuring the mass and distance of an FFP lens requires determining the size of the source star ρ, measuring the microlens parallax

, and using high-resolution imaging to search for the lens flux

from a possible host star. Here we investigate the accessible parameter space for each of these components considering different satellites for a range of FFP masses, Galactic distances, and source star properties. We find that at the beginning of K2C9, when its projected separation

from the Earth is ≲0.2 au, it will be able to measure

for Jupiter-mass FFP candidates at distances larger than ∼2 kpc and to Earth-mass lenses at ∼8 kpc. At the end of K2C9, when

= 0.81 au, it is sensitive to planetary-mass lenses for distances ≳3.5 kpc, and even then only to those with mass ≳M
Jup. From lens flux constraints we find that it will be possible to exclude hosts down to the deuterium-burning limit for events within ∼2 kpc. This indicates that the ability to characterize FFPs detected during K2C9 is optimized for events occurring toward the beginning of the campaign. WFIRST, on the other hand, will be able to detect and characterize FFP masses down to or below super-Earths throughout the Galaxy during its entire microlensing survey.
RADIAL PROFILE OF THE 3.5 keV LINE OUT TO R200 IN THE PERSEUS CLUSTER
Authors: Franse Jeroen , Bulbul Esra , Foster Adam , Boyarsky Alexey , Markevitch Maxim , Bautz Mark , Iakubovskyi Dmytro , Loewenstein Mike , McDonald Michael , Miller Eric , Randall Scott W. , Ruchayskiy Oleg , Smith Randall K. 
Published: September 2016

ABSTRACT
The recent discovery of the unidentified emission line at 3.5 keV in galaxies and clusters has attracted great interest from the community. As the origin of the line remains uncertain, we study the surface brightness distribution of the line in the Perseus cluster since that information can be used to identify its origin. We examine the flux distribution of the 3.5 keV line in the deep Suzaku observations of the Perseus cluster in detail. The 3.5 keV line is observed in three concentric annuli in the central observations, although the observations of the outskirts of the cluster did not reveal such a signal. We establish that these detections and the upper limits from the non-detections are consistent with a dark matter decay origin. However, absence of positive detection in the outskirts is also consistent with some unknown astrophysical origin of the line in the dense gas of the Perseus core, as well as with a dark matter origin with a steeper dependence on mass than the dark matter decay. We also comment on several recently published analyses of the 3.5 keV line.