bluuebunny/crossref_metadata_2025_split huggingface dataset:
Scale‐up and operation of a pilot‐scale ammonia fiber expansion reactor
Authors: Campbell Tim , Bals Bryan , Teymouri Farzaneh , Glassbrook John , Nielson Chandra , Videto Josh , Rinard Anthony , Moore Janette , Julian Allen , Bringi Venkataraman 
Published: December 2019

AbstractPretreatment and densification of agricultural residues at regional depots can simplify feedstock supply logistics for the production of biofuels in commercial biorefineries. We have previously reported the performance of a laboratory‐scale (5 L) packed‐bed ammonia fiber expansion (AFEX) reactor system, which showed significant promise for biomass pretreatment at distributed depots. In this paper, we describe the performance of a 90‐fold larger pilot‐scale packed‐bed AFEX‐reactor system, used to produce over 1,500 batches (~36 tons) of pretreated crop residues over a 5‐year period. Virtually all unreacted ammonia was successfully removed from the biomass, and 76% of the ammonia was recycled and reused. Pretreatment performance at pilot scale was comparable to laboratory‐scale, averaging 74% glucose and 75% xylose yield in a standard test compared with 71% and 73%, respectively. Other operating and maintenance aspects are also discussed.
Real‐time dissolved carbon dioxide monitoring I: Application of a novel in situ sensor for CO2 monitoring and control
Authors: Chopda Viki R. , Holzberg Timothy , Ge Xudong , Folio Brandon , Tolosa Michael , Kostov Yordan , Tolosa Leah , Rao Govind 
Published: December 2019

AbstractDissolved carbon dioxide (dCO2) is a well‐known critical parameter in bioprocesses due to its significant impact on cell metabolism and on product quality attributes. Processes run at small‐scale faces many challenges due to limited options for modular sensors for online monitoring and control. Traditional sensors are bulky, costly, and invasive in nature and do not fit in small‐scale systems. In this study, we present the implementation of a novel, rate‐based technique for real‐time monitoring of dCO2 in bioprocesses. A silicone sampling probe that allows the diffusion of CO2 through its wall was inserted inside a shake flask/bioreactor and then flushed with air to remove the CO2 that had diffused into the probe from the culture broth (sensor was calibrated using air as zero‐point calibration). The gas inside the probe was then allowed to recirculate through gas‐impermeable tubing to a CO2 monitor. We have shown that by measuring the initial diffusion rate of CO2 into the sampling probe we were able to determine the partial pressure of the dCO2 in the culture. This technique can be readily automated, and measurements can be made in minutes. Demonstration experiments conducted with baker's yeast and Yarrowia lipolytica yeast cells in both shake flasks and mini bioreactors showed that it can monitor dCO2 in real‐time. Using the proposed sensor, we successfully implemented a dCO2‐based control scheme, which resulted in significant improvement in process performance.
Chemical Composition of Volatiles of Eight Geranium L. Species from Vlasina Plateau (South Eastern Serbia)
Authors: Ilić Milan D. , Marčetić Mirjana D. , Zlatković Bojan K. , Lakušić Branislava S. , Kovačević Nada N. , Drobac Milica M. 
Published: December 2019

AbstractGeranium species are widely used in traditional medicine of Balkan. The aim of this work was to investigate and compare chemical composition of volatile fractions obtained by hydrodistillation from aerial parts of G. macrorrhizum, G. phaeum, G. sanguineum, G. robertianum, G. palustre, G. pyrenaicum, G. columbinum and G. lucidum as well as from underground parts of G. macrorrhizum and G. phaeum, originated from Vlasina plateau in South Eastern Serbia. The volatiles were analyzed using GC/MS and GC‐FID. G. palustre volatiles have been studied for the first time with β‐selinene (18.6 %) as a characteristic compound. The cluster analysis revealed separation of volatiles into two main groups. Volatile fractions of G. macrorrhizum were separated from all other samples due to high sesquiterpene content (92.3 % in aerial and 94.6 % in underground parts). The volatile fractions of other samples were mainly composed of sesquiterpenes (10.8–61.8 %), diterpenes (12.9–43.0 %) and fatty acids and their derivatives (6.6–21.6 %) with the exception of volatile fraction of G. phaeum underground parts which was dominated only by fatty acids and their derivatives (76.6 %). The results presented in this article contribute to the knowledge on the chemistry of this genus and advances the knowledge on flora of southeast Serbia.
Live‐Cell Sensing of Telomerase Activity by Using Hybridization‐Sensitive Fluorescent Oligonucleotide Probes
Authors: Chen Jiazhuo , Morihiro Kunihiko , Fukui Daisuke , Guo Lihao , Okamoto Akimitsu 
Published: December 2019

AbstractLive‐cell sensing of telomerase activity with simple and efficient strategies remains a challenging target. In this work, a strategy for telomerase sensing by using hybridization‐sensitive fluorescent oligonucleotide probes is reported. In the presence of telomerase and dNTPs, the designed supporting strand was extended and generated the hairpin structure that catalyzed the next telomerase extending reaction. The special extension mechanism increased the local concentration of another supporting strand and telomerase, which resulted in enhanced telomerase activity. The hybridization‐sensitive oligonucleotide probes bound to the hairpin catalyst and generated turn‐on fluorescence. This method realized the sensing of telomerase activity in HeLa cell extract with a detection limit below 1.6×10−6 IU μL−1. The real‐time in situ observation of telomerase extension was achieved in living HeLa cells. This strategy has been applied to monitor the efficiency of telomerase‐targeting anticancer drugs in situ.
A Guide for Realizing Efficient Polymer Light‐Emitting Electrochemical Cells in a Single Active Layer Device Structure
Authors: Kim Seunghan , Lee Jong Ik , Yang Jeehye , Shin Ik‐Soo , Earmme Taeshik , Kang Moon Sung 
Published: December 2019

AbstractHere, we systematically examine the impact of electrode work function, ionic species, and charge injection layers on the operation of polymer light‐emitting electrochemical cells (PLECs) based on p‐type Super Yellow. To achieve PLECs yielding a more intensive luminance compared to what can be achieved from the non‐ionic light‐emitting device counterpart, i. e., the polymer light‐emitting diode (PLED), in an analogous device structure, the experimental results here guide the following lessons. First, the use of charge injection layer does not necessarily yield a PLEC that outperforms its PLED counterpart but rather complexes the device structure. Second, injection of minority electrons is critical for enhancing the luminescence characteristics of p‐type polymer based LECs, and the enhanced electron injection is achieved more effectively by modifying the work function of the cathode than by changing the cations. Third, for p‐type PLECs with a low‐work function cathode, careful selection of anions can drastically change the device performance, which are involved in the p‐type electrochemically doping process.
Reactivity of Binary and Ternary Sulfur Halides towards Transition‐Metal Compounds
Authors: Dirican Dilcan , Pfister Nils , Wozniak Martin , Braun Thomas 
Published: December 2019

AbstractBinary sulfur fluorides exhibit an interesting reactivity towards transition metal complexes. They open up routes for the generation of sulfur‐containing building blocks. Often ligands with particular properties can be constructed. This includes their ability to transfer sulfur atoms or polysulfide units as well as fluorination reactions. This Minireview provides an insight into the reactivity of the binary and ternary sulfur halides S2Cl2, SCl2, SF4, SF6 and SF5Cl towards transition‐metal compounds.
Bottom‐up Design of Bimetallic Cobalt–Molybdenum Carbides/Oxides for Overall Water Splitting
Authors: Liu Rongji , Anjass Montaha , Greiner Simon , Liu Si , Gao Dandan , Biskupek Johannes , Kaiser Ute , Zhang Guangjin , Streb Carsten 
Published: December 2019

AbstractEarth‐abundant transition‐metal‐based catalysts for electrochemical water splitting are critical for sustainable energy schemes. In this work, we use a rational design method for the synthesis of ultrasmall and highly dispersed bimetallic CoMo carbide/oxide particles deposited on graphene oxide. Thermal conversion of the molecular precursors [H3PMo12O40], Co(OAc)2⋅4 H2O and melamine in the presence of graphene oxide gives the mixed carbide/oxide (Co6Mo6C2/Co2Mo3O8) nanoparticle composite deposited on highly dispersed, N,P‐doped carbon. The resulting composite shows outstanding electrocatalytic water‐splitting activity for both the oxygen evolution and hydrogen evolution reaction, and superior performance to reference samples including commercial 20 % Pt/C & IrO2. Electrochemical and other materials analyses indicate that Co6Mo6C2 is the main active phase in the composite, and the N,P‐doping of the carbon matrix increases the catalytic activity. The facile design could in principle be extended to multiple bimetallic catalyst classes by tuning of the molecular metal oxide precursor.
Aerogeles – Modern Functional Materials for Chemistry Lessons?
Authors: Fenner Christiane , Gräb Patrick , Reichenauer Gudrun , Scherdel Christian , Beierle Kristina , Geidel Ekkehard 
Published: December 2019

AbstractAerogele zeichnen sich als moderne Funktionswerkstoffe durch herausragende und gezielt modifizierbare Eigenschaften aus. Diese beruhen auf ihrer spezifischen hochporösen Struktur. Die daraus resultierende Vielzahl hochinteressanter Einsatzmöglichkeiten macht die Stoffklasse zum Gegenstand intensiver Forschung. Im Beitrag wird eine an schulische Gegebenheiten angepasste Synthese und Trocknung eines organisch modifizierten Silica‐Aerogels vorgestellt. Die Charakterisierungen der so hergestellten Proben belegen die aerogeltypischen Eigenschaften des erhaltenen Materials. Abschließend werden unterrichtliche Einsatzmöglichkeiten anhand von einfachen Freihandversuchen und Überlegungen zur didaktischen Einbettung aufgezeigt.
Construction of Defective Zinc–Cadmium–Sulfur Nanorods for Visible‐Light‐Driven Hydrogen Evolution Without the Use of Sacrificial Agents or Cocatalysts
Authors: Zhang Guoqiang , Ling Xiang , Liu Guoshuai , Xu Yangsen , Xiao Shuning , Zhang Qitao , Yang Xun , Qiu Chuntian , Mi Hongwei , Su Chenliang 
Published: December 2019

AbstractSolar‐driven H2 evolution is an essential process for sustainable energy development. Currently, the greatest challenge is the development of efficient photocatalysts to drive this reaction, especially in pure water systems (without the use of a sacrificial agent). In this study, structural defects in Zn–Cd–S nanorod photocatalysts are found to increase charge separation efficiency significantly by sevenfold. Efficient H2 evolution (352.7 μmol h−1 g−1, 100 mg of catalyst) is achieved by using this defective Zn–Cd–S nanorod photocatalyst in the absence of sacrificial agents and precious metal cocatalysts under visible‐light irradiation. Thus, this cocatalyst‐ and sacrificial‐agent‐free, visible‐light‐responsive system shows remarkable potential as a new artificial photosynthesis route for green H2 production.
Limitation of complementary resources affects colony growth, foraging behavior, and reproduction in bumble bees
Authors: Requier Fabrice , Jowanowitsch Kim K. , Kallnik Katharina , Steffan‐Dewenter Ingolf 
Published: December 2019

AbstractResource availability in agricultural landscapes has been disturbed for many organisms, including pollinator species. Abundance and diversity in flower availability benefit bee populations; however, little is known about which of protein or carbohydrate resources may limit their growth and reproductive performance. Here, we test the hypothesis of complementary resource limitation using a supplemental feeding approach. We applied this assumption with bumble bees (Bombus terrestris), assuming that colony growth and reproductive performance should depend on the continuous supply of carbohydrates and proteins, through the foraging for nectar and pollen, respectively. We placed wild‐caught bumble bee colonies along a landscape gradient of seminatural habitats, and monitored the colonies’ weight, foraging activity, and reproductive performance during the whole colony cycle. We performed supplemental feeding as an indicator of landscape resource limitation, using a factorial design consisting of the addition of sugar water (carbohydrate, supplemented or not) crossed by pollen (protein, supplemented or not). Bumble bee colony dynamics showed a clear seasonal pattern with a period of growth followed by a period of stagnation. Higher abundance of seminatural habitats resulted in reducing the proportion of pollen foragers relative to all foragers in both periods, and in improving the reproductive performance of bumble bees. Interestingly, the supplemental feeding of sugar water positively affected the colony weight during the stagnation period, and the supplemental feeding of pollen mitigated the landscape effect on pollen collection investment. Single and combined supplementation of sugar water and pollen increased the positive effect of seminatural habitats on reproductive performance. This study reveals a potential colimitation in pollen and nectar resources affecting foraging behavior and reproductive performance in bumble bees, and indicates that even in mixed agricultural landscapes with higher proportions of seminatural habitats, bumble bee populations face resource limitations. We conclude that the seasonal management of floral resources must be considered in conservation to support bumble bee populations and pollination services in farmlands.
Thermal niche diversity and trophic redundancy drive neutral effects of warming on energy flux through a stream food web
Authors: Nelson Daniel , Benstead Jonathan P. , Huryn Alexander D. , Cross Wyatt F. , Hood James M. , Johnson Philip W. , Junker James R. , Gíslason Gísli M. , Ólafsson Jón S. 
Published: December 2019

AbstractClimate warming is predicted to alter routing and flows of energy through food webs because of the critical and varied effects of temperature on physiological rates, community structure, and trophic dynamics. Few studies, however, have experimentally assessed the net effect of warming on energy flux and food web dynamics in natural intact communities. Here, we test how warming affects energy flux and the trophic basis of production in a natural invertebrate food web by experimentally heating a stream reach in southwest Iceland by ~4°C for 2 yr and comparing its response to an unheated reference stream. Previous results from this experiment showed that warming led to shifts in the structure of the invertebrate assemblage, with estimated increases in total metabolic demand but no change in annual secondary production. We hypothesized that elevated metabolic demand and invariant secondary production would combine to increase total consumption of organic matter in the food web, if diet composition did not change appreciably with warming. Dietary composition of primary consumers indeed varied little between streams and among years, with gut contents primarily consisting of diatoms (72.9%) and amorphous detritus (19.5%). Diatoms dominated the trophic basis of production of primary consumers in both study streams, contributing 79–86% to secondary production. Although warming increased the flux of filamentous algae within the food web, total resource consumption did not increase as predicted. The neutral net effect of warming on total energy flow through the food web was a result of taxon‐level variation in responses to warming, a neutral effect on total invertebrate production, and strong trophic redundancy within the invertebrate assemblage. Thus, food webs characterized by a high degree of trophic redundancy may be more resistant to the effects of climate warming than those with more diverse and specialized consumers.
Improving spatial predictions of animal resource selection to guide conservation decision making
Authors: Gerber Brian D. , Northrup Joseph M. 
Published: December 2019

AbstractResource selection is often studied by ecologists interested in the environmental drivers of animal space use and movement. These studies commonly produce spatial predictions, which are of considerable utility to resource managers making habitat and population management decisions. It is thus paramount that predictions from resource selection studies are accurate. We evaluated model building and fitting strategies for optimizing resource selection function predictions in a use‐availability framework. We did so by simulating low‐ and high‐intensity spatial sampling data that respectively predicted study area and movement‐based resource selection. We compared one of the most commonly used forms of statistical regularization, Akaike's Information Criterion (AIC), with the lesser used least absolute shrinkage and selection operator (LASSO). LASSO predictions were less variable and more accurate than AIC and were often best when considering additive and interacting variables. We explicitly demonstrate the predictive equivalence using the logistic and Poisson likelihoods and how it is lost when the available sample is too small. Regardless of modeling approach, interpreting the sign of coefficients as a measure of selection can be misleading when optimizing for prediction.
Systolic blood pressure, heart rate, and outcomes in patients with coronary disease and heart failure
Authors: Elgendy Islam Y. , Hill James A. , Szady Anita D. , Gong Yan , Cooper‐DeHoff Rhonda M. , Pepine Carl J. 
Published: December 2019

AbstractAimsData regarding the optimal systolic blood pressure (SBP) and heart rate (HR) for coronary artery disease (CAD) patients with hypertension and a history of heart failure (HF) are limited. Accordingly, using data from a large clinical trial, we investigated the association between SBP and heart rate and subsequent adverse outcomes in CAD patients with a history of HF, and we aimed to better understand how pre‐existing HF impacts outcomes among patients with CAD.Methods and resultsAmong 22 576 CAD patients enrolled in the INternational VErapamil SR‐Trandolapril STudy (INVEST), 1256 were identified with a history of physician‐diagnosed HF New York Heart Association (NYHA) Class 1–3 at entry. The primary outcome was the first occurrence of all‐cause death, myocardial infarction (MI), or stroke. Cox proportional‐hazards models adjusted for pre‐specified covariates were constructed to estimate risk among the HF cohort compared with a case‐matched sample from the non‐HF cohort. At a mean 2.5 years' follow‐up, those with prior HF had a higher risk of the primary outcome (hazard ratio (HR) 2.55, 95% confidence interval 2.30–2.83, P < 0.0001). Among those with history of HF, a low (<120 mmHg) or high (>140 mmHg) SBP and heart rate ≥ 85 b.p.m. were associated with increased risk for adverse outcomes, which persisted after covariate adjustment.ConclusionsIn patients with CAD, a physician diagnosis of HF at baseline portended a higher risk for death, MI, or stroke than in those without an HF history. Achieving SBP of 120–140 mmHg and heart rate < 85 b.p.m. was associated with a better outcome in patients with known HF and CAD.
Volatility term structures in commodity markets
Authors: Hollstein Fabian , Prokopczuk Marcel , Würsig Christoph 
Published: December 2019

AbstractIn this study, we comprehensively examine the volatility term structures in commodity markets. We model state‐dependent spillovers in principal components (PCs) of the volatility term structures of different commodities, as well as that of the equity market. We detect strong economic links and a substantial interconnectedness of the volatility term structures of commodities. Accounting for intra‐commodity‐market spillovers significantly improves out‐of‐sample forecasts of the components of the volatility term structure. Spillovers following macroeconomic news announcements account for a large proportion of this forecast power. There thus seems to be substantial information transmission between different commodity markets.
Peristaltic flow of Buongiorno model nanofluids within a sinusoidal wall surface used in drug delivery
Authors: Gajbhare Bhimanand Pandurang , Krishnaprasad J. S. V. R. , Mishra Satyaranjan 
Published: December 2019

AbstractThe current paper deals with the radiative heat transfer of the peristaltic flow of the Buongiorno model nanofluid through a two‐dimensional channel with a sinusoidal wall surface. A particular form of fluid transport occurring through progressive wave of expansion or contraction generating along a distensible tube containing fluid is known as peristaltic pumping, which takes place from the lower pressure region to the higher pressure region. Peristaltic transport finds several applications, such as blood pumping in heart, lung, and pharmacological delivery systems, and industrial applications—sanitary fluid transport, corrosive fluids transport, and so on. An approximate analytical solution is employed for the solution of the system of transformed differential equations with prescribed boundary conditions. The influences of physical parameters characterizing the flow phenomena are obtained and presented via graphs. The result warrants a good correlation with earlier studies in particular case. The following are the main findings: thermophoresis is favorable to enhance the fluid temperature near the channel center and also the axial velocity increases as an increase in the thermal buoyancy parameter. However, the main findings are elaborated in Section 3.
Synthesis of 1H‐isochromenes, 4H‐chromenes, and ortho‐aminocarbonitrile tetrahydronaphthalenes from the same reactants by using metal‐free catalyst
Authors: Naeimi Hossein , Mohammadi Somaye 
Published: December 2019

AbstractA facile and rapid multicomponent synthesis of pharmaceutically diverse 1H‐isochromenes, 4H‐chromenes, and ortho‐aminocarbonitrile tetrahydronaphthalenes has been developed from benzaldehyde, malononitrile, and cyclohexanone. Three different methods from the same reactants, solvent, temperature, and catalyst lead to three products with excellent yields. All the reactions were followed with the Michael addition and cyclization. In this study, morpholine was used as an active metal‐free base catalyst that increases the yields of products and decreases the time of reactions.