bluuebunny/crossref_metadata_2025_split huggingface dataset:
The evaluation of time‐resolved Raman spectroscopy for the suppression of background fluorescence from space‐relevant samples
Authors: Hanke Franziska , Mooij Bram J.A. , Ariese Freek , Böttger Ute 
Published: May 2019

AbstractOne of the primary goals in space research is the search for signs of extant or extinct extraterrestrial life, and Raman spectroscopy can play a role in this field. Raman spectrometers are planned for future missions to Mars and possibly the Moon to identify the mineralogical surface composition and potentially existing organic compounds (especially on Mars). However, a major challenge in Raman spectroscopy, especially in the visible range, is the strong fluorescence background. Time‐resolved Raman spectroscopy (TRRS) can provide selective detection of Raman signals over the generally longer living fluorescence. This study investigates the potential of a TRRS system, using 3‐ps, 440‐nm laser pulses and time‐gated detection with an intensified charge‐coupled device (CCD) camera. Test samples were the lichen Xanthoria elegans as an extraterrestrial life analogue, and a lunar regolith analogue material (LRS) as a planetary surface analogue. The TRRS technique is evaluated by comparing gated to nongated Raman spectroscopy using different detectors but with otherwise the same instrument and identical measurement conditions. The gated spectra of X. elegans showed significant signal‐to‐noise ratio (SNR) improvements compared to the nongated spectra. The visible Raman lines could be assigned to the photoprotective pigment parietin. For the LRS sample, measurement spots with a good SNR in the nongated spectrum were not significantly improved by measuring in gated mode. However, spots dominated by fluorescence showed significant improvement in gated mode because of fluorescence suppression. Minerals such as plagioclase, diopside, olivine, apatite, and a carbonate mineral were detected. In most cases, TRRS provided better results compared to nongated measurements, demonstrating the suitability for future space‐exploration missions.
Controlled Growth of Polyamide Films atop Homogenous and Heterogeneous Hydrogels Using Gel–Liquid Interfacial Polymerization
Authors: Wang Mengyuan , Stafford Christopher M. , Cox Lewis M. , Blevins Adrienne K. , Aghajani Masoud , Killgore Jason P. , Ding Yifu 
Published: May 2019

AbstractControlled growth of crosslinked polyamide (PA) thin films is demonstrated at the interface of a monomer‐soaked hydrogel and an organic solution of the complementary monomer. Termed gel–liquid interfacial polymerization (GLIP), the resulting PA films are measured to be chemically and mechanically analogous to the active layer in thin film composite (TFC) membranes. PA thin films are prepared using the GLIP process on both a morphologically homogeneous hydrogel prepared from poly(2‐hydroxyethylmethacrylate) and a phase‐separated, heterogeneous hydrogel prepared from poly(acrylamide). Two monomer systems are examined: trimesoyl chloride (TMC) reacting with m‐phenylene diamine (MPD) and TMC reacting with piperazine (PIP). Unlike the self‐limiting growth behavior in TFC membrane fabrication, diffusion‐limited, continuous growth of the PA films is observed, where both the thickness and roughness of the PA layers increase with reaction time. A key morphological difference is found between the two monomer systems using the GLIP process; TMC/MPD produces a ridge‐and‐valley surface morphology whereas TMC/PIP produces nodule/granular structures. The GLIP process represents a unique opportunity to not only explore the pore characteristics (size, spacing, and continuity) on the resulting structure and morphology of the interfacially polymerized thin films, but also a method to modify the surface of (or encapsulate) hydrogels.
Evaluation of an automated grid artifact detection system for quality control in digital mammography
Authors: MacLellan Christopher J. , Layman Rick R. , Geiser William , Gress Dustin A. , Jones A. Kyle 
Published: May 2019

PurposeGrid artifacts occur in digital mammography when synchronization between the grid assembly and generator is not achieved, including when malfunctions occur in the grid assembly or generator subsystems. Such artifacts are not explicitly monitored or evaluated by existing mammography quality control programs. In this study, we developed an automated method for quantifying the presence of grid artifacts in two‐dimensional (2D) digital mammography images and assessed its utility as a supplement to existing quality control programs.MethodsFour digital mammography systems (Hologic Dimensions 3D 5000) were configured to automatically transfer 2D images to a server where the strength of the grid pattern, γmax, was quantified using a template‐matching algorithm and stored in amySQL database. This analysis was performed on both American College of Radiology (ACR) phantom and clinical images. Changes in γmax were compared with image quality and service records to establish preliminary action limits for physicist intervention for each type of image. These action limits were applied around selected service events to evaluate their clinical utility.ResultsAll systems exhibited a gradual increase in γmax in ACR phantom images prior to having identical major components of the generator subsystem replaced, despite the absence of visible gridlines in the images. Retrospective analysis of phantom images suggested that physicists should consider AEC testing when exceeds 0.050 and that clinical image quality may be affected when exceeds 0.060. Eighteen of 19 visible grid artifacts were identified using a threshold value of 0.065 in clinical images. Warning limits that indicate abnormal operation before visible degradation in image quality were also established. These warning limits were 0.046 and 0.041 for the 24 × 29 cm and 18 × 24 cm paddles, respectively. Specific malfunctions in the generator and grid subsystems can be detected by applying these limits.ConclusionsAutomated monitoring of provides useful information about the status of digital mammography units without affecting clinical operations. When used with appropriate action limits, this type of monitoring can help physicists identify specific equipment malfunctions before they would be detected by other quality control tests and before they affect clinical images.
Synthesis, Structural Characterization and Photodecarbonylation Study of a Dicarbonyl Ruthenium(II)‐Bisquinoline Complex
Authors: Kubeil Manja , Joshi Tanmaya , Wood Bayden R. , Stephan Holger 
Published: May 2019

AbstractA photoactivatable ruthenium(II) carbonyl complex mer,cis‐[Ru(II)Cl(BisQ)(CO)2]PF6 2 was prepared using a tridentate bisquinoline ligand (BisQ=(2,6‐diquinolin‐2‐yl)pyridin). Compound 2 was thoroughly characterized by standard analytical methods and single crystal X‐ray diffraction. The crystal structure of the complex cation reveals a distorted octahedral geometry. The decarbonylation upon exposure to 350 and 420 nm light was monitored by UV/VIS absorbance and Fourier transform infrared spectroscopies in acetonitrile and 1 % (v/v) DMSO in water, respectively. The kinetic of the photodecarbonylation has been elucidated by multivariate curve resolution alternating least‐squares analysis. The stepwise decarbonylation follows a serial mechanism. The first decarbonylation occurs very quickly whereas the second decarbonylation step proceeds more slowly. Moreover, the second rate constant is lower in 1 % (v/v) DMSO in water than in acetonitrile. In comparison to 350 nm irradiation, exposure to 420 nm light in acetonitrile results in a lower second rate constant.
Teacher Incentives and Student Achievement: Evidence from an Advancement Program
Authors: Eren Ozkan 
Published: May 2019

AbstractThis paper examines the effects of a comprehensive performance pay program implemented in high‐need schools using administrative data from Louisiana. Exploiting the within‐student variation in the timing of implementation, we find a large and significant effect beginning with the second year of the program on math achievement. Similar but generally insignificant point estimates are observed in social studies. As for English Language Arts and science, there are no effects of the program. We provide evidence against changes in the composition of teacher workforce and postadoption student sorting as potential explanations for our results. We then show aggregate findings from a web‐survey that teachers may have altered their teaching practices following performance‐based compensation. Finally, under certain assumptions, we calculate the net present value of earnings impact to be close to a million dollars per school‐year for math.
Fostering sustainable improvements in science education: An analysis through four frames
Authors: Reinholz Daniel L. , Ngai Courtney , Quan Gina , Pilgrim Mary E. , Corbo Joel C. , Finkelstein Noah 
Published: May 2019

AbstractThere is a pressing need to improve the sustainability of educational improvement efforts, but sustainability remains undertheorized in science education. In this article, we draw upon frameworks from organizational culture and sustainability to characterize change within a single undergraduate science department. This in‐depth longitudinal case study over 15 years provides careful documentation of the types of changes that are required to make improvements over time. In particular, we argue that cultural shifts are an important aspect of sustainable improvements. As we show, even a department that was considered an educational improvement “success story” was unable to sustain the improvements made through its initial effort. Nonetheless, we do argue that the initial effort resulted in shifts to multiple aspects of the department's culture (e.g., ways of thinking, the status of education in the department), that we characterize with Bolman and Deal's four frames. These cultural shifts provided the groundwork for a later effort, to ultimately create sustainable structures in the department resulting in sustained improvement. To conclude, we provide recommendations for how to improve the sustainability of change efforts and describe important methodological considerations for future studies of sustainability.
A New Insight into Non‐Steroidal Anti‐Inflammatory Drugs (NSAIDs) as Modulated Green Inhibitory Agent on Mild Steel Corrosion
Authors: Patel Dhruvi , Makwana Krutarth , Shirdhonkar Manjusha B. , Kuperkar Ketan C. 
Published: May 2019

AbstractPresent study investigate the corrosion inhibition action of green non‐steroidal anti‐inflammatory drugs (NSAIDs) on mild steel (MS) in 1 M HCl by Gravimetric method, Electrochemical Impedance Spectroscopy and Potentiodynamic Tafel polarization at 303.15 K. Changes occurring in the impedance parameters (Rct and Cdl) give clear indication of drug adsorption on the metal surface. Polarization study inferred these drugs to act as a mixed inhibitor. Experimental results inferred a rise in inhibition efficiency with increasing drug concentration. i. e. 90%, 71% and 85% for Aspirin (∼0.3 mM), Diclofenac (∼0.1 mM) and Ibuprofen (∼0.7 mM) respectively. The formation of the Fe‐inhibitor complex and the corrosion inhibition mechanism was inferred by spectral study. Scanning electron microscopy (SEM) and Atomic force microscopy (AFM) gave evidences of the surface topography and proved that the metal surface resist corrosion in presence of inhibitor than in its absence. The degree of hydrophobicity induced due to drug adsorption as obtained by contact angle (CA) is in good agreement with the microscopic results which inferred NSAIDs to act as an effective inhibitor in acidic corrodent. Thermodynamic study confirmed the adsorption process to be spontaneous i. e., ΔG̊ads lies between −17.0 to −20.0 kJ mol−1 which obeyed the Langmuir isotherm. A successive correlation of NSAIDs with their calculated molecular orbital energy levels is well explained using simulation by Density Functional Theory.
A Green Protocol for the Synthesis of α‐Diazo‐β‐hydroxyesters and One‐Pot Conversion to β‐Keto‐Esters and Imidazo[1,2‐a]pyridine‐3‐carboxylates
Authors: Dutta Nibedita Baruah , Sharma Suraj , Chetry Rudra Lal , Baishya Gakul 
Published: May 2019

AbstractA new solvent cum reagent system comprising of water extract of banana ash and dimethylsulfoxide (WEB‐DMSO) has been engaged for the first time to promote the aldol type condensation reaction of aldehydes with ethyl diazoacetate. The condensation reaction has smoothly undergone producing a range of α‐diazo‐β‐hydroxy esters in good to excellent yields. The solvent system has been reused up to five times without loss of its catalytic activity. Further, two one‐pot sequential reactions have been developed in the same reaction medium. First, the methodology has been extended to synthesize β‐keto esters through Pd catalyzed 1,2‐hydrogen migration. Secondly, β‐keto esters have been converted to imidazo[1,2‐a]pyridine‐3‐carboxylates by using N‐bromosuccinimide and 2‐aminopyridines in a one‐pot fashion.
Silk Composite Electronic Textile Sensor for High Space Precision 2D Combo Temperature–Pressure Sensing
Authors: Wu Ronghui , Ma Liyun , Hou Chen , Meng Zhaohui , Guo Wenxi , Yu Weidong , Yu Rui , Hu Fan , Liu Xiang Yang 
Published: May 2019

AbstractWearable electronic textiles based on natural biocompatible/biodegradable materials have attracted great attention due to applications in health care and smart clothes. Silkworm fibers are durable, good heat conductors, insulating, and biocompatible, and are therefore regarded as excellent mediating materials for flexible electronics. In this paper, a strategy on the design and fabrication of highly flexible multimode electronic textiles (E‐textile) based on functionalized silkworm fiber coiled yarns and weaving technology is presented. To achieve enhanced temperature sensing performance, a mixture of carbon nanotubes and an ionic liquid ([EMIM]Tf2N) is embedded, which displays top sensitivity of 1.23% °C−1 and stability compared with others. Furthermore, fibrous pressure sensing based on the capacitance change of each cross‐point of two yarns gives rise to highly position dependent and sensitivity sensing of 0.136 kPa−1. Based on weaving technologies, a unique combo textile sensor, which can sense temperature and pressure independently with a position precision of 1 mm2, is obtained. The application to intelligent gloves endows the position dependent sensing of the weight, and temperature distribution sensing of the temperature.
Study of a new type of replaceable coupling beam in reinforced concrete shear wall structures
Authors: Li Shurong , Jiang Huanjun , He Liusheng 
Published: May 2019

SummaryIt has been found from the past earthquakes that the reinforced concrete coupling beams in tall buildings easily suffer severe damage, which are very difficult to be repaired. To solve this problem, a new type of replaceable coupling beam with a combined damper installed in the middle was proposed in this study. The combined damper consists of an I‐shaped steel beam with multiple low‐yield‐point steel webs paralleled to each other and multiple layers of viscoelastic material bonded between multiple steel plates. The design method of the new replaceable coupling beam was introduced first. Cyclic loading tests on the combined damper were conducted to examine its mechanical behavior. To verify the effectiveness of the new replaceable coupling beam in resisting wind and seismic excitations, two high‐rise building structures, one with traditional coupling beams and the other with the proposed replaceable coupling beams, were designed, and the responses of two structures under the wind and the earthquake were compared with the aid of software Perform‐3D. Compared with the structure with traditional coupling beams, both of the seismic performance and the wind resistance capability of the structure with the proposed replaceable coupling beams are improved significantly.
Descent of fetal head during active pushing: secondary analysis of prospective cohort study investigating ultrasound examination before operative vaginal delivery
Authors: Kahrs B. H. , Usman S. , Ghi T. , Youssef A. , Torkildsen E. A. , Lindtjørn E. , Østborg T. B. , Benediktsdottir S. , Brooks L. , Harmsen L. , Salvesen K. Å. , Lees C. C. , Eggebø T. M. 
Published: May 2019

ABSTRACTObjectivesTo investigate if descent of the fetal head during active pushing is associated with duration of operative vaginal delivery, mode of delivery and neonatal outcome in nulliparous women with prolonged second stage of labor.MethodsThis was a prospective cohort study of nulliparous women with prolonged second stage of labor, conducted between November 2013 and July 2016 in five European countries. Fetal head descent was measured using transperineal ultrasound. Head–perineum distance (HPD) was measured between contractions and on maximum contraction during active pushing, and the difference between these values (ΔHPD) was calculated. The main outcome was duration of operative vaginal delivery, estimated using survival analysis to calculate hazard ratios (HRs) for vaginal delivery, with values > 1 indicating a shorter duration. HR was adjusted for prepregnancy body mass index, maternal age, induction of labor, augmentation with oxytocin and use of epidural analgesia. Pregnancies were grouped according to ΔHPD quartile, and delivery mode and neonatal outcome were compared between groups.ResultsThe study population comprised 204 women. Duration of vacuum extraction was shorter with increasing ΔHPD. Estimated mean duration was 10.0, 9.0, 8.8 and 7.5 min in pregnancies with ΔHPD in the first to fourth quartiles, respectively, and the adjusted HR for vaginal delivery, using increasing ΔHPD as a continuous variable, was 1.04 (95% CI, 1.01–1.08). Mean ΔHPD was 7 mm (range, −10 to 37 mm). ΔHPD was either negative or ≤ 2 mm in the lowest quartile. In this group, 7/50 (14%) pregnancies were delivered by Cesarean section, compared with 8/154 (5%) of those with ΔHPD > 2 mm (P < 0.05). There was no significant association between umbilical artery pH < 7.10 or 5‐min Apgar score < 7 and ΔHPD quartile.ConclusionMinimal or no fetal head descent during active pushing was associated with longer duration of operative vaginal delivery and higher frequency of Cesarean section in nulliparous women with prolonged second stage of labor. © 2019 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.
Mirrors without warnings
Authors: Frigg Roman , Nguyen James 
Published: May 2019

AbstractVeritism, the position that truth is necessary for epistemic acceptability, seems to be in tension with the observation that much of our best science is not, strictly speaking, true when interpreted literally. This generates a paradox: (1) truth is necessary for epistemic acceptability; (2) the claims of science have to be taken literally; (3) much of what science produces is not literally true and yet it is acceptable. We frame Elgin’s project inTrue Enoughas being motivated by, and offering a particular resolution to, this paradox. We discuss the paradox with a focus on scientific models and argue that there is another resolution available which is compatible with retaining veritism: rejecting the idea that scientific models should be interpreted literally.
Functional explanation in mathematics
Authors: Inglis Matthew , Mejía-Ramos Juan Pablo 
Published: May 2019

AbstractMathematical explanations are poorly understood. Although mathematicians seem to regularly suggest that some proofs are explanatory whereas others are not, none of the philosophical accounts of what such claims mean has become widely accepted. In this paper we explore Wilkenfeld’s (Synthese 191:3367–3391, 2014) suggestion that explanations are those sorts of things that (in the right circumstances, and in the right manner) generate understanding. By considering a basic model of human cognitive architecture, we suggest that existing accounts of mathematical explanation are all derivable consequences of Wilkenfeld’s ‘functional explanation’ proposal. We therefore argue that the explanatory criteria offered by earlier accounts can all be thought of as features that make it more likely that a mathematical proof will generate understanding. On the functional account, features such as characterising properties, unification, and salience correlate with explanatoriness, but they do not define explanatoriness.
Realism without representationalism
Authors: Rydenfelt Henrik 
Published: May 2019

AbstractScientific realism is a critical target of anti-representationalists such as Richard Rorty and Huw Price, who have questioned the very possibility of providing a satisfactory argument for realism or any other ontological position. I will argue that there is a viable form of realism which not only withstands this criticism but is vindicated on the antirepresentationalists’ own grounds. This realist position, largely drawn from the notion of the scientific method developed by the founder of philosophical pragmatism, Charles S. Peirce, will further be compared with the accounts of truth and objectivity proposed by the contemporary pragmatists, Rorty, Price, and Robert B. Brandom.
The rise of encrypted malware
Authors: Yaacoubi Omar 
Published: May 2019

Increasingly complex multi-cloud architectures and more stringent regulatory environments have increased reliance on encryption – primarily secure sockets layer (SSL) and transport layer security (TLS) – to the extent that over 80% of all network traffic is now encrypted. While in many ways the growth of encryption is a good thing for security, it also creates a backdoor for hackers and threat actors looking to hide from traditional detection tools. Organisations are adopting more stringent encryption practices. And while the growth of encryption might seem a good thing for security, it also creates a backdoor for hackers and threat actors looking to hide from detection tools. Additionally, as organisations continue to move to the cloud, increase their utilisation of APIs and adopt ever-more complex and sensitive systems, they find themselves with ever-more complex multi-cloud architectures. The solution lies in encrypted cognitive analytics, argues Omar Yaacoubi of Barac, which enables the creation of new types of data elements or telemetry that are independent of protocol details.
Marx's Conception of Dialectical Contradiction in Commodity
Authors: Abazari Arash 
Published: May 2019

AbstractIn this paper, I clarify the structure of dialectical contradiction in Marx in order to show how it is influenced by Hegel. To this aim, I focus on the only place where Marx systematically develops the concept of dialectical contradiction, namely, in his analysis of commodity in the first chapter of Capital. Here Marx claims that the commodity is the contradictory unity of use-value and exchange-value. To make this claim intelligible, I first discuss Hegel's conception of ‘the thing’ [Das Ding] in the Science of Logic and demonstrate how for Hegel ‘the thing’ is the contradictory unity of matter and form. With this Hegelian machinery, then, I turn to Marx to show how use-value and exchange-value constitute the matter and the form of commodity, and argue how they contradict each other.