bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increasing the Ligand Field Strength in Butadiene Open Sandwich Compounds from the First to the Second Row Transition Metals
Authors: Qian Junfeng , Chen Qun , He Mingyang , Zhang Zhihui , Feng Xuejun , Xie Yaoming , King R. Bruce , Schaefer Henry F. 
Published: June 2020

AbstractThe structures and energetics of the bis(butadiene) complexes of the second row transition metals (C4H6)2M) M=Zr to Pd) have been investigated by density functional theory. The energetically accessible (C4H6)2M structures (M=Zr to Rh) are found to have only tetrahapto η4‐C4H6 ligands. The second row transition metals energetically prefer low spin states in their bis(butadiene) derivatives (C4H6)2M reflecting their increased ligand field strength relative to the first row transition metals. Thus the energies of the singlet and doublet spin states for (C4H6)2Ru and (C4H6)2Tc, respectively, are lower than their triplet and quartet spin state isomers in contrast to the corresponding iron and manganese systems, respectively. Furthermore, the staggered maximum spin (C4H6)2M structures with χ ≈ 90° having tetrahedral coordination of the central metal to the four C=C double bonds of the two butadiene ligands found as lowest energy structures for the first row transition metals are not found for the second row transition metals from Mo to Pd. Instead the lowest energy (C4H6)2M structures for the second row transition metals have an eclipsed confirmation with χ ≈ 0° implying square planar coordination of the central metal. The lowest energy structure of the palladium complex (C4H6)2Pd is anomalous since only one of the two butadienes is a tetrahapto ligand whereas the second butadiene is only a dihapto ligand leaving one uncomplexed C=C double bond.
Systematic comparison framework for selecting the best retrofitting alternative for an existing water resource recovery facility
Authors: Machado Vinicius Cunha , Lafuente Javier , Baeza Juan Antonio 
Published: June 2020

AbstractA systematic comparison framework for selecting the best retrofitting alternative for a water resource recovery facility (WRRF) is proposed in this work. The procedure is applied comparing different possible plant configurations to retrofit an existent anoxic/oxic (A/O) WRRF (Manresa, Spain) aiming to include enhanced biological phosphorus removal (EBPR). The framework for comparison was built on system analysis using a calibrated IWA ASM2d model. A multicriteria set of performance variables, as the operational and capital expenditures (OPEX and CAPEX, respectively) and robustness tests for measuring how fast the plant configuration refuses external disturbances (like ammonium and phosphate peak loads), were used for comparison. Starting from the existent WRRF, four plant configurations were tested: single A2/O (only one anoxic reactor converted to anaerobic), double A2/O (two anoxic reactors converted to anaerobic), BARDENPHO, and UCT. The double A2/O plant configuration was the most economical and reliable alternative for improving the existent Manresa WRRF capacity and implementing EBPR, since the effluent quality increased 3.8% compared to the current plant configuration. In addition, the double A2/O CAPEX was close to €165,000 which was at the same order of the single A2/O and lower than the BARDENPHO and UCT alternatives.Practitioner points

Four configurations including EBPR were evaluated for retrofitting an A/O WRRF.

A new multicriteria comparison framework was used to select the best configuration.

Up to 13 criteria related to effluent quality, robustness and costs were included.

A single function based on the combination of all the criteria was also evaluated.
A Comparison of Two Methods to Monitor Translocated Prairie Dogs
Authors: Sack Danielle A. , Tripp Daniel W. 
Published: June 2020

ABSTRACTThe effects of sylvatic plague and habitat fragmentation present species conservation challenges for prairie dogs (Cynomys spp.) and other wildlife species they support. Active reestablishment of extirpated prairie dog colonies may become increasingly necessary to achieve some conservation goals. We compared a passive‐integrated‐transponder (PIT) tag monitoring system and trail camera photographs to monitor short‐term survival of captive dye‐marked black‐tailed prairie dogs (Cynomys ludovicianus) translocated into artificial burrows. We deployed cameras and a PIT‐tag monitoring system in 2016 and 2017 (Nov–Sep) and collected 1.2 million PIT‐tag scans and >255,000 photographs at a Colorado Parks and Wildlife facility near Fort Collins, Colorado, USA. There was no difference in the daily mean number of prairie dogs detected between the 2 monitoring methods (photographs  = 3.40, PIT tags  = 4.06). However, PIT‐tag scans achieved a population census in 10 days (100% detected, 95% CI = 89–100%); whereas, photographs were able to detect only 67% of the prairie dogs during this same time (95% CI = 50–80%). Trail camera photographs of uniquely dye‐marked individuals may be ideal for short‐term monitoring (≤6 months), while PIT tags are likely to outperform cameras in studies requiring efficient longer term monitoring of permanently marked prairie dogs. Although both monitoring techniques performed well in a semicaptive setting, how these techniques would perform when scaled to larger or more complex settings requires further research. © 2020 The Authors. Wildlife Society Bulletin published by Wiley Periodicals LLC on behalf of The Wildlife Society.
Rectal gas-induced susceptibility artefacts on prostate diffusion-weighted MRI with epi read-out at 3.0 T: does a preparatory micro-enema improve image quality?
Authors: Plodeck Verena , Radosa Christoph Georg , Hübner Hans-Martin , Baldus Christian , Borkowetz Angelika , Thomas Christian , Kühn Jens-Peter , Laniado Michael , Hoffmann Ralf-Thorsten , Platzek Ivan 
Published: June 2020

Abstract
Purpose
To assess whether the application of a preparatory micro-enema reduces gas-induced susceptibility artefacts on diffusion-weighted MRI of the prostate.

Methods
114 consecutive patients who received multiparametric 3 T MRI of the prostate at our institution were retrospectively enrolled. 63 patients self-administered a preparatory micro-enema prior to imaging, and 51 patients underwent MRI without bowel preparation. Two blinded readers independently reviewed the diffusion-weighted sequences regarding gas-induced artefacts. The presence/severity of artefacts was scored ranging from 0 (no artefact) to 3 (severe artefact). A score ≥ 2 was considered a clinically relevant artefact. Maximum rectal width at the level of the prostate was correlated with the administration of a micro-enema. Scores were compared between the scans performed with and without bowel preparation using univariable and multivariable logistic regression, taking into account potential confounding factors (age and prostate volume).

Results
Significantly less artefacts were found on diffusion-weighted sequences after the administration of a micro-enema shortly prior to MR imaging. Clinically relevant artefacts were found in 10% in the patient group after enema, in 41% without enema. If present, artefacts were also significantly less severe. Mean severity score was 0.3 (enema administered) and 1.2 (no enema), and odds ratio was 0.137 (p < 0.0001) in univariable ordinal logistic regression. Inter-observer agreement was excellent (κ 0.801).

Conclusion
The use of a preparatory micro-enema prior to 3 T multiparametric prostate MRI significantly reduces both the incidence and severity of gas-induced artefacts on diffusion-weighted sequences and thus improves image quality.
The Current Evidence for Defining and Assessing Effectiveness of Surgical Educators: A Systematic Review
Authors: Dickinson Karen J. , Bass Barbara L. , Pei Kevin Y. 
Published: June 2020

AbstractBackgroundSurgical educator effectiveness is valued but lacks an operational definition. Clearly defining attributes consistent with effective surgical educators allows for the development of professional activities directed to nurture these qualities. Our aim was to identify the literature defining qualities of an effective surgical educator, and tools to measure effectiveness.MethodsWe searched PubMed, Medline, Scopus and Academic Search Complete for English language articles from 1 July 2009–1 July 2019. Two reviewers screened all abstracts for relevance and read full text of selected articles to identify included studies. Inclusion criteria were description/definition of an effective surgical educator or description of assessment/measurement of effectiveness in surgical educators. Data extracted included: study design, participants, definition/description of qualities of an effective surgical educator, qualitative or quantitative methods to assess surgical educators.ResultsInitial search identified 8086 articles. Of these, 2357 articles were excluded as duplicates and 5729 abstracts screened with 5638 excluded due to irrelevance. Full text review was performed for 91 articles to assess eligibility, 23 met inclusion criteria. The majority (74%) did not clearly define an effective surgical educator. Themes from six studies that determined important qualities include: communication, leadership skills, professionalism, respect, positive learning climate, and brief‐intraoperative teaching‐debrief model. One validated assessment tool was identified.ConclusionsThere is little published work defining or assessing effective surgical educators. Establishment of a positive learning climate and excellent communication skills continue to be important qualities that define surgical educator effectiveness.
Learning from the past: did experience with previous epidemics help mitigate the impact of COVID-19 among spine surgeons worldwide?
Authors: Weiner Joseph A. , Swiatek Peter R. , Johnson Daniel J. , Louie Philip K. , Harada Garrett K. , McCarthy Michael H. , Germscheid Niccole , Cheung Jason P. Y. , Neva Marko H. , El-Sharkawi Mohammad , Valacco Marcelo , Sciubba Daniel M. , Chutken Norman B. , An Howard S. , Samartzis Dino 
Published: June 2020

Abstract
Purpose
Spine surgeons around the world have been universally impacted by COVID-19. The current study addressed whether prior experience with disease epidemics among the spine surgeon community had an impact on preparedness and response toward COVID-19.

Methods
A 73-item survey was distributed to spine surgeons worldwide via AO Spine. Questions focused on: demographics, COVID-19 preparedness, response, and impact. Respondents with and without prior epidemic experience (e.g., SARS, H1NI, MERS) were assessed on preparedness and response via univariate and multivariate modeling. Results of the survey were compared against the Global Health Security Index.

Results
Totally, 902 surgeons from 7 global regions completed the survey. 24.2% of respondents had prior experience with global health crises. Only 49.6% reported adequate access to personal protective equipment. There were no differences in preparedness reported by respondents with prior epidemic exposure. Government and hospital responses were fairly consistent around the world. Prior epidemic experience did not impact the presence of preparedness guidelines. There were subtle differences in sources of stress, coping strategies, performance of elective surgeries, and impact on income driven by prior epidemic exposure. 94.7% expressed a need for formal, international guidelines to help mitigate the impact of the current and future pandemics.

Conclusions
This is the first study to note that prior experience with infectious disease crises did not appear to help spine surgeons prepare for the current COVID-19 pandemic. Based on survey results, the GHSI was not an effective measure of COVID-19 preparedness. Formal international guidelines for crisis preparedness are needed to mitigate future pandemics.
Unburned hydrocarbon formation in a natural gas engine under sea wave load conditions
Authors: Tavakoli Sadi , Jensen Michael Vincent , Pedersen Eilif , Schramm Jesper 
Published: June 2020

AbstractAlthough natural gas is documented as a low-emission fuel compared to the other traditional fossil fuels in internal combustion engines, recent research indicates large amounts of methane emission released by lean burn gas engines and highlights the importance of this emission on global warming. This paper aims at illustrating the main sources of unburned fuel in internal combustion engines with an emphasis on spark ignited natural gas engines. In addition, two unburned hydrocarbon modeling patterns, empirical and thermodynamic, are proposed. Moreover, a verified engine model including all components with an implemented dynamic load based on harmonic sea waves has been set up and coupled to the unburned hydrocarbon formation models. Results show that load variation may contribute to further methane slip and this increment rises sharply when the load amplitude enlarges. The maximum amount of methane slip occurs at reduced loads when the time lag of the control system of the turbocharger causes additional fresh air to flow towards the combustion chamber and brings the flame into the quenching area. As well, inspecting unburned hydrocarbon emission in diverse air–fuel ratios but with the same wave frequency and amplitude uncovers the sensitivity of lean burn gas engines to the dynamic load.
Adapted Wasserstein distances and stability in mathematical finance
Authors: Backhoff-Veraguas Julio , Bartl Daniel , Beiglböck Mathias , Eder Manu 
Published: June 2020

AbstractAssume that an agent models a financial asset through a measure ℚ with the goal to price/hedge some derivative or optimise some expected utility. Even if the model ℚ is chosen in the most skilful and sophisticated way, the agent is left with the possibility that ℚ does not provide anexactdescription of reality. This leads us to the following question: will the hedge still be somewhat meaningful for models in the proximity of ℚ?If we measure proximity with the usual Wasserstein distance (say), the answer is No. Models which are similar with respect to the Wasserstein distance may provide dramatically different information on which to base a hedging strategy.Remarkably, this can be overcome by considering a suitableadaptedversion of the Wasserstein distance which takes the temporal structure of pricing models into account. This adapted Wasserstein distance is most closely related to the nested distance as pioneered by Pflug and Pichler (SIAM J. Optim. 20:1406–1420, 2009, SIAM J. Optim. 22:1–23, 2012, Multistage Stochastic Optimization, 2014). It allows us to establish Lipschitz properties of hedging strategies for semimartingale models in discrete and continuous time. Notably, these abstract results are sharp already for Brownian motion and European call options.
Fidelity Scale: From Black Box to Holy Grail
Authors: van Weeghel Jaap 
Published: June 2020

AbstractFidelity scales are indispensable in the pursuit of evidence-based mental healthcare. Without fidelity checks, treatment remains a mysterious black box. The aim of this article is to comment on the studies in this special section, and to discuss some general issues with regard to fidelity assessment. Despite all of their supposed benefits, resistance to fidelity scales persists among mental health practitioners. One way to overcome this resistance is to conduct fidelity assessments in the context of a well-guided learning community. The predictive validity of fidelity scales is considered the single most valuable attribute of these instruments. Research on predictive validity requires large sample sizes, which is difficult to achieve. It should nevertheless not prevent us from rigorously searching for this Holy Grail of fidelity assessment. In addition, fidelity assessment should be placed in a broader perspective. The quality of care for people with severe mental illness cannot be assessed conclusively according to the extent to which separate interventions have been applied with good fidelity. These individuals need access to high-quality treatment and support systems within the community, which can enable them to live their lives as valued citizens. In conclusion, fidelity assessment, both at the level of interventions and systems, contributes to a highly desirable transparency in practice variations within the field of mental healthcare.
“Pure” severe aortic stenosis without concomitant valvular heart diseases: echocardiographic and pathophysiological features
Authors: Kandels J. , Tayal B. , Hagendorff A. , Lavall D. , Laufs U. , Sogaard P. , Andersen N. H. , Stöbe S. 
Published: June 2020

Abstract
Purpose
In echocardiography the severity of aortic stenosis (AS) is defined by effective orifice area (EOA), mean pressure gradient (mPGAV) and transvalvular flow velocity (maxVAV). The hypothesis of the present study was to confirm the pathophysiological presence of combined left ventricular hypertrophy (LVH), diastolic dysfunction (DD) and pulmonary artery hypertension (PAH) in patients with “pure” severe AS.

Methods and Results
Patients (n = 306) with asymptomatic (n = 133) and symptomatic (n = 173) “pure” severe AS (mean age 78 ± 9.5 years) defined by indexed EOA < 0.6 cm2 were enrolled between 2014 and 2016. AS patients were divided into 4 subgroups according to mPGAV and indexed left ventricular stroke volume: low flow (LF) low gradient (LG)-AS (n = 133), normal flow (NF) LG-AS (n = 91), LF high gradient (HG)-AS (n = 21) and NFHG-AS (n = 61). Patients with “pure” severe AS showed mean mPGAV of 31.7 ± 9.1 mmHg and mean maxVAV of 3.8 ± 0.6 m/s. Only 131 of 306 patients (43%) exhibited mPGAV > 40 mmHg and maxVAV > 4 m/s documenting incongruencies of the AS severity assessment by Doppler echocardiography. LVH was documented in 81%, DD in 76% and PAH in 80% of AS patients. 54% of “pure” AS patients exhibited all three alterations. Ranges of mPGAV and maxVAV were higher in patients with all three alterations compared to patients with less than three. 224 (73%) patients presented LG-conditions and 82 (27%) HG-conditions. LVH was predominant in NF-AS (p = 0.014) and PAH in LFHG-AS (p = 0.014). Patients’ treatment was retrospectively assessed (surgery: n = 100, TAVI: n = 48, optimal medical treatment: n = 156).

Conclusion
In patients with “pure” AS according to current guidelines the presence of combined LVH, DD and PAH as accepted pathophysiological sequelae of severe AS cannot be confirmed. Probably, the detection of these secondary cardiac alterations might improve the diagnostic algorithm to avoid overestimation of AS severity.
Reassessment of the Binary Mn–Rh Phase Diagram and Experimental Investigations of the Ternary Bi–Mn–Rh System
Authors: Kainzbauer Peter , Marker Martin C. J. , Richter Klaus W. 
Published: June 2020

AbstractThe binary manganese–rhodium (Mn–Rh) phase diagram was reinvestigated from 5 to 90 at.% Rh with focus on determining the transition temperature between the ordered γ′-Mn3Rh and the γ-Mn phase as well as the transition temperature between of the tetragonal and cubic MnRh phase and phase boundaries, applying XRD, DTA and SEM including EDX. A reassessment of the Mn–Rh phase diagram based on obtained and literature data is given. Furthermore, the phase equilibria of the ternary bismuth–manganese–rhodium (Bi–Mn–Rh) system were experimentally investigated, focusing on the possible existence of new ferromagnetic phases. Isothermal sections at 330 °C and 600 °C were studied applying powder XRD and EDX. The corresponding phase diagram was established based on these results. No additional ferromagnetic phase was found in the ternary system.
Modelling impulsive noise in indoor powerline communication systems
Authors: Karakuş Oktay , Kuruoğlu Ercan E. , Altınkaya Mustafa A. 
Published: June 2020

AbstractPowerline communication (PLC) is an emerging technology that has an important role in smart grid systems. Due to making use of existing transmission lines for communication purposes, PLC systems are subject to various noise effects. Among those, the most challenging one is the impulsive noise compared to the background and narrowband noise. In this paper, we present a comparative study on modelling the impulsive noise amplitude in indoor PLC systems by utilising several impulsive distributions. In particular, as candidate distributions, we use the symmetric$$\alpha $$α-Stable (S$$\alpha $$αS), generalised Gaussian, Bernoulli Gaussian and Student’stdistribution families as well as the Middleton Class A distribution, which dominates the literature as the impulsive noise model for PLC systems. Real indoor PLC system noise measurements are investigated for the simulation studies, which show that the S$$\alpha $$αS distribution achieves the best modelling success when compared to the other families in terms of the statistical error criteria, especially for the tail characteristics of the measured data sets.
Finite element modeling of the shaped charge jet and design of the reusable perforating gun
Authors: Zhang Zhao , Jin Wei-Wei 
Published: June 2020

AbstractFinite element method is used to study the formations of the penetration jet, the bulge, and the burr in the designed reusable perforating gun. The attached layer of the soft metal on the perforator is studied for the controlling of the bulge height on the casing of the reusable perforating gun. Results indicate that the shaped charge jet is initially formed in the center of the shaped charge liner and then the material of the liner is driven to the centerline of the liner by the detonation wave. The attachment of the soft metal layer to the cartridge of the perforator can be beneficial to control the bulge height. The design on the blind holes on the casing can affect the burr height formed by the collision between the jet and the casing. With the increase in the liner angle, the penetration width on the cement wall of the wellbore is increased.
Re-assessment and tune-up gas condensate reservoir potential in Northern Iraq using material balance and reservoir simulation result techniques
Authors: Ahmed Barzan I. , Al-Jawad Mohammed S. 
Published: June 2020

AbstractThe main parameter that drives oil industry contract investment and set up economic feasibility study for approving field development plan is hydrocarbon reservoir potential. So a qualified experience should be deeply afforded to correctly evaluate hydrocarbons reserve by applying different techniques at each phase of field management, through collecting and using valid and representative data sources, starting from exploration phase and tune-up by development phase. Commonly, volumetric calculation is the main technique for estimate reservoir potential using available information at exploration stage which is quite few data; in most cases, this technique estimate big figure of reserve. In this study case, volumetric calculation estimate gas initial in place (GIIP) value almost two times bigger than other techniques estimation of actual reservoir potential; it is a result of Asphiltena “Bitumen” existing in reservoir interval which occupied part of matrix pore and fill some fractures. This investigation is raised up at early field production life: material balance calculation and run simulation analysis are applied to re-assessment and tune-up reservoir potential; both techniques are set up almost same GIIP value which principally tuned to actual reservoir dynamic energy behavior. Finally, material balance should be viewed as a complement to simulation, not as a competing approach, and using both to improve analysis of hydrocarbon reservoirs.