bluuebunny/crossref_metadata_2025_split huggingface dataset:
High Volumetric Specific Impulse Composite Propellant Based on Terminally Functionalized Block Copolymers of Polybutadiene and ϵ‐Caprolactone
Authors: Singh Harmeet , Singh Darshana , Chimurkar Dhanraj , Upadhyay Jayesh , Kumar Amit , Kumar Arvind , Pande Shrikant , More Priyesh 
Published: December 2019

AbstractFor enhanced range, higher payload capacities and for miniaturized propulsion systems, today's strategic and tactical weapon system designers demand for higher density and specific impulse of the propellant. In order to enhance the density impulse of HTPB/DOA/RDX/AP/Al based composite propellant, studies have been carried to replace conventional HTPB/DOA binder system with hydroxyl terminated block copolymer of polybutadiene and ϵ‐caprolactone with NG as plasticizer. Total eight numbers of compositions were formulated with varying content of RDX. Both binder systems were compared in propellant compositions by evaluating various physical, thermal and ballistic properties. Various rocket performance parameters of each formulation were theoretically predicted by NASA CEC‐71 program and burning rate was measured in pressure ranges of 3‐7 and 7‐11 MPa by the acoustic emission technique. In addition, density, viscosity build up, calorimetric values, thermal decomposition and sensitivity parameters of each composition were also assessed and compared. In an outcome, it was concluded that HTBCP25/NG based propellant compositions enhance the density by 4.4–5 % and calorimetric values by 12–15 % as compared to HTPB/DOA based compositions. Strand burning rate data show enhancement of burning rate by 40–70 % at 7 MPa pressure in HTBCP25/NG based compositions. Impact and friction sensitivity data also revealed their utility in propellant compositions for future applications.
How the environmental fate of clomazone in rice fields is influenced by amendment with olive‐mill waste under different regimes of irrigation and tillage
Authors: Fernández Damián , Gómez Soraya , Albarrán Ángel , Peña David , Rozas María Ángeles , Rato‐Nunes Jose M , López‐Piñeiro Antonio 
Published: December 2019

AbstractBACKGROUNDIrrigation and tillage systems alone or in combination with organic amendments can strongly influence soil properties, which in turn may also modify the environmental fate of any pesticides applied. This study was aimed at determining how amendment with composted olive‐mill waste (W) influenced leaching, sorption, and persistence of the herbicide clomazone in rice field soils under different tillage and irrigation management practices. The field trial conducted covered 3 years in succession, with six treatments: irrigation by sprinkler and conventional tillage without (ST) or with W application (80 Mg ha−1) (STW), irrigation by sprinkler but no tillage (SNT), irrigation by sprinkler but no tillage with W application (SNTW), and continuous flooding irrigation and tillage without (FT) and with W application (FTW).RESULTSApplication of W significantly increased the adsorption of clomazone to soil in the first and third years. In the first year, the persistence of clomazone under aerobic (t1/2 = 33.1–36.3 days) and anaerobic incubation conditions (t1/2 = 3.43–10.8 days) decreased after W application to t1/2 values in the ranges 18.1–29.7 and 3.06–5.44 days, respectively. However, in the third year, although clomazone persistence increased significantly in SNT and ST when W was applied under both incubation conditions, it decreased significantly in FT management under anaerobic incubation conditions. The addition of W led to less leaching of clomazone, particularly for the FT case where the herbicide leaching losses were 2.8 and 2.6 times lower in the first and third years after W addition, respectively.CONCLUSIONSUsing W as an organic amendment could be regarded as an invaluable strategy to reduce water contamination by clomazone in rice production, especially under traditional tillage and flooding management. © 2019 Society of Chemical Industry
A predictive Bayesian approach to sequential time‐between‐events monitoring
Authors: Ali Sajid 
Published: December 2019

AbstractA fundamental problem with all process monitoring techniques is the requirement of a large Phase‐I data set to establish control limits and overcome estimation error. This assumption of having a large Phase‐I data set is very restrictive and often problematic, especially when the sampling is expensive or not available, eg, time‐between‐events (TBE) settings. Moreover, with the advancement in technology, quality practitioners are now more interested in online process monitoring. Therefore, the Bayesian methodology not only provides a natural solution for sequential and adaptive learning but also addresses the problem of a large Phase‐I data set for setting up a monitoring structure. In this study, we propose Bayesian control charts for TBE assuming homogenous Poisson process. In particular, a predictive approach is adopted to introduce predictive limit control charts. Beside the Bayesian predictive Shewhart charts with dynamic control limits, a comparison of the frequentist sequential charts, designed by using unbiased and biased estimator of the process parameter, is also a part of the present study. To assess the predictive TBE chart performance in the presence of practitioner‐to‐practitioner variability, we use the average of the average run length (AARL) and the standard deviation of the in‐control run length (SDARL).
Low‐concentration hydrogen peroxide decontamination for Bacillus spore contamination in buildings
Authors: Mickelsen Ronald Leroy , Wood Joseph , Calfee Michael Worth , Serre Shannon , Ryan Shawn , Touati Abderrahmane , Delafield Francis Robbins , Aslett Lola Denise 
Published: December 2019

AbstractRemediation and recovery efforts after a release of Bacillus anthracis (anthrax) spores may be difficult and costly. In addition, response and recovery technologies may be focused on critical resources, leaving the small business or homeowner without remediation options. This study evaluates the efficacy of relatively low levels of hydrogen peroxide vapor (HPV) delivered from off‐the‐shelf equipment for the inactivation of Bacillus spores within an indoor environment. Decontamination evaluations were conducted in a house using both Bacillus atrophaeus var. globigii (Bg; as surrogates for B. anthracis) inoculated on the carpet and galvanized metal as coupons and Geobacillus stearothermophilus (Gs) as biological indicators on steel. The total decontamination time ranged from 4 to 7 days. Using the longer exposure times, low concentrations of HPV (average levels below 20 parts per million) effectively inactivated Bg and Gs spores on the materials tested. The HPV was generated with commercial humidifiers and household‐strength hydrogen peroxide solutions. The presence of home furnishings did not have a significant impact on HPV efficacy. This simple, inexpensive, and effective decontamination method could have significant utility for remediation following a B. anthracis spore release, such as following a terrorist attack.
Current status and challenges of remediating petroleum‐derived PAHs in soils: Nigeria as a case study for developing countries
Authors: Offiong Nnanake‐Abasi O. , Inam Edu J. , Etuk Helen S. , Essien Joseph P. 
Published: December 2019

AbstractPolycyclic aromatic hydrocarbons (PAHs) are among the world's most significant environmental organic contaminants because of their carcinogenic properties. PAHs are widely distributed globally as a result of releases from numerous natural and anthropogenic activities. Consequently, several PAH monitoring studies have been conducted and remediation approaches explored. This article aims to provide the current status of PAH distribution in Nigeria's oil and gas industrial region in relation to the technologies adopted for PAH remediation. Ideally, the findings will provide insight into the challenges in managing organic contaminants derived from petroleum exploration activities in developing countries with Nigeria as a case study.
Perception‐aware autonomous mast motion planning for planetary exploration rovers
Authors: Strader Jared , Otsu Kyohei , Agha‐mohammadi Ali‐akbar 
Published: December 2019

AbstractHighly accurate real‐time localization is of fundamental importance for the safety and efficiency of planetary rovers exploring the surface of Mars. Mars rover operations rely on vision‐based systems to avoid hazards as well as plan safe routes. However, vision‐based systems operate on the assumption that sufficient visual texture is visible in the scene. This poses a challenge for vision‐based navigation on Mars where regions lacking visual texture are prevalent. To overcome this, we make use of the ability of the rover to actively steer the visual sensor to improve fault tolerance and maximize the perception performance. This paper answers the question of where and when to look by presenting a method for predicting the sensor trajectory that maximizes the localization performance of the rover. This is accomplished by an online assessment of possible trajectories using synthetic, future camera views created from previous observations of the scene. The proposed trajectories are quantified and chosen based on the expected localization performance. In this study, we validate the proposed method in field experiments at the Jet Propulsion Laboratory (JPL) Mars Yard. Furthermore, multiple performance metrics are identified and evaluated for reducing the overall runtime of the algorithm. We show how actively steering the perception system increases the localization accuracy compared with traditional fixed‐sensor configurations.
Ethnodance and identity: Black students representing science identities in the making
Authors: Chappell Mindy J. , Varelas Maria 
Published: December 2019

AbstractWe explored how arts‐based practices, specifically what we define as ethnodance informs the study of science identity. We present a theoretical argument supported by an empirical illustration of how ethnodance offers Black youth with dance identities a medium to narrate evolving science identities, communicating meanings, interactions, and emotions, and to construct identities further as reified artifacts of participating in science classroom communities. The theoretical argument frames dance as an embodied narrative, identity construction as an ongoing process with interactional and affective commitments, and Black Dances as venues of Black bodies’ expressivity of the brilliance, competence, and creativity of Black people. The empirical illustration focuses on Black students in an urban high school choreographing a dance performance to capture their science identity construction transitioning from biology and moving through physics. The students’ semiotic choices communicated the experienced (dis)connection between self and science; ballet, lyrical, and contemporary dances represented experiences challenging their position within science, and a Black Dance, majorette, experiences affirming their place or creating a bridge. Majorette offered students a sense of cultural solidarity, symbolic of their collective overcoming of obstacles faced, frustration, and alienation felt at the beginning of physics, and joy of rising above the struggle.
Design, Synthesis and In Vitro Trypanocidal and Leishmanicidal Activities of 2‐(2‐Arylidene)hydrazono‐4‐oxothiazolidine‐5‐acetic Acid Derivatives
Authors: Haroon Muhammad , Akhtar Tashfeen , da S. Santos Aline C. , Pereira Valéria R. A. , Ferreira Luiz F. G. R. , Hernandes Marcelo Z. , Rocha Rafael E. O. , Ferreira Rafaela S. , de M. Gomes Paulo A. T. , de Sousa Fabiano A. , de B. Dias Mabilly C. H. , Tahir Muhammad N. , Hameed Shahid , Leite Ana C. L. 
Published: December 2019

AbstractTrypanosomatids are protozoan parasites responsible for leishmaniasis, Chagas disease and sleeping sickness. The design of new antitrypanosomatid drugs with trypanosomicidal and leishmanicidal activities is an effective perspective. The thiazolidinone ring is an important scaffold for several biological disorders. Herein, 4‐oxothiazolidine‐5‐acetic acids (1 a‐1 w) have been synthesized from respective thiosemicarbazone and maleic anhydride. Some of these 4‐oxothiazolidine‐5‐acetic acids were toxic for trypomastigotes without affecting macrophages viability. From this series, compounds 1 e (IC50=10 μM), 1 u (IC50=8.94 μM), 1 g (IC50=5.65 μM) and 1 w (14.06 μM) showed the best anti‐T. cruzi activity for trypomastigote form, while 1 e, 1 u and 1 g showed SI higher than benznidazole (BZD). Similarly, against epimastigote the compound 1 q (IC50epi= 4.70 μM) has been found more selective and most active than benznidazole. However, evaluation against T. cruzi revealed that most of the active compounds have a low inhibition profile and weak leishmanicidal activity. In silico data suggests a good drug‐likeness profile, high chemical stability and demonstrate the use of these compounds in the designing of new anti‐T. cruzi and anti‐Leishmanial drugs.
Improvement of the Biological Activity of a New Cobalt(III) Complex through Loading into a Nanocarrier, and the Characterization Thereof
Authors: Talebi Sanaz , Amani Vahid , Saber‐Tehrani Mandana , Abedi Anita 
Published: December 2019

AbstractIn an effort to use a polymer carrier for the maintenance of biological activity of metal complexes; in this report, a novel cobalt(III) complex, trans‐[Co(en)2(mtzt)2]NO3 (1) was prepared (en=ethylenediamine and Hmtzt=1‐methyl‐1‐H‐1,2,3,4‐tetrazol‐5‐thiol) and fully characterized. A biocompatible di‐block polymer, containing poly lactic‐co‐glycolic acid and poly ethylene glycol (PLGA‐PEG), was employed as the nanocarrier of complex 1 to achieve more efficacy and controlled drug release. Results illustrated that the successful loading of the cobalt complex on the PLGA‐PEG polymer as well as pH dependent drug release with approximately 17%, 58% and 74% release within 168 hours at pH=7.4, 5.8 and 4.8 respectively. Antibacterial properties of complex 1 and corresponding nanocarrier have been determined against gram‐negative (Escherichia coli) and gram‐positive (Staphylococcus aureus) bacteria where the loading of the complex on nanocarrier enhances its antibacterial activity. Their anticancer activity was also evaluated over human ovarian carcinoma cells and compared with cisplatin.
Exfoliated Graphene Sheets: Polymer Nanoparticles as a Tool and Their Anti‐Proliferative Activity
Authors: Siddique Jamal A. , Attia Nour F. , Tyagi Nisha , Geckeler Kurt E. 
Published: December 2019

AbstractA facile one‐pot and environment‐friendly method has been developed for the synthesis of graphene sheets. Poly(vinylpyrrolidone) nanoparticles with a size range of 23–57 nm are used for the exfoliation process of graphene sheets in conjunction with ultrasonication. The polymer nanoparticle size played a significant role in the exfoliation yield of the graphene sheets. The small nanoparticle size of 23 nm was found to be the most effective size for the exfoliation. Thus, high quality individualized graphene sheets were obtained and the sheet thickness was found to be 4 nm. The polymer nanoparticles contributed to stable graphene dispersions through wrapping on the surface of the sheets. The graphene sheets have been characterized by using Raman and UV‐Vis spectroscopy and their morphology visualized by transmission electron microscopy. In addition, the as‐prepared graphene sheets were investigated as a potential cytotoxic drug and their anti‐proliferative activity was studied in vitro by the MMT assay. The results showed a remarkable lethality rate of 87% for human colon cancer cells (HCT‐116) and biocompatibility to normal mouse embryonic fibroblast NIH‐3T3 cells.
Biotransformation of Host Plant Flavonoids by the Fungal Endophyte Epicoccum nigrum
Authors: Harwoko Harwoko , Hartmann Rudolf , Daletos Georgios , Ancheeva Elena , Frank Marian , Liu Zhen , Proksch Peter 
Published: December 2019

AbstractFermentation of the fungus Epicoccum nigrum isolated from leaves of Salix sp. on green lentil solid medium yielded the flavonol kaempferol (3) as well as two kaempferol O‐diglycosides (1 and 2) including the new compound 1. The fungal flavonoids bear strong structural similarities to kaempferol derivatives such as kaempferol O‐glycoside (4) being present in green lentils. Furthermore, feeding experiments were conducted by adding flavonoids (kaempferol and rutin) as precursors to solid rice media followed by HPLC and LC‐MS analyses. Fermentation of the fungus on flavonoid free solid rice medium afforded flavonoid free extracts indicating that the fungal flavonoids originate through hydrolytic cleavage of kaempferol glycosides such as 4 followed by glycosylation and acetylation. This study suggests that E. nigrum is capable of biotransformation reactions of plant derived flavonoids whereas de novo biosynthesis of flavonoids is less likely.
Synthesis of a Stable, Water‐Tolerant, Short Mesoporous Organic Biguanide, Strong Solid Base and Its Application in Catalysis
Authors: Pan Langsheng , Zhao Xiaoyu , Wu Mei , Xiang Fuyun , Li Yongfei , Liu Yuejin 
Published: December 2019

AbstractFirstly, both a short mesopore thin plate molecular sieve of Zr‐doped SBA‐15 and a strong organic base of bi‐guanides DIC‐TMG were respectively prepared. Then, the organic bi‐guanides DIC‐TMG was grafted onto the short mesopore thin plate molecular sieve to prepare a highly efficient and stable water‐tolerant short mesoporous organic bi‐guanides strong solid base DIC‐TMG/Zr‐SBA‐15 which was used to catalyze the transesterification of renewable bio‐oils to biodiesel under mild reaction conditions. The prepared DIC‐TMG/Zr‐SBA‐15 was elaborately investigated by XRD, BET, SEM, TEM, FT‐IR and Elemental analysis. The obtained results showed that compared with TMG/Zr‐SBA‐15 and DIC‐TMG/SBA‐15, DIC‐TMG/Zr‐SBA‐15 exhibited the best catalytic activity with 95% of biodiesel yield at reaction temperature 75 °C and catalyst dosage 5 wt%. Especially, unlike some other usually solid metal‐based catalysts, this alkaline organic bi‐guanidines DIC‐TMG supported on Zr‐SBA‐15 support catalyst has certain water‐tolerant. With 1 wt% of water content existed in the reaction system, the biodiesel yield still reached 90%, and after five recycles of the catalyst, the biodiesel yield was still more than 80%.
Synthesis and Evaluation of Acid‐base Bi‐functional MOFs Catalyst Supported on PVDF Membrane for Glucose Dehydration to 5‐HMF
Authors: Yan Changhao , Zhang Yunlei , Da Zulin , Wie Yanan , Li Bing , Meng Minjia , Yuan Shouqi , Yan Yongsheng 
Published: December 2019

AbstractMetal‐organic frameworks (MOFs) catalysts loaded on carriers with acid‐base functional active sites could be applied widely to heterogeneous catalysis, which can promote stability and activity. In this work, we report a modulated hydrothermal (MHT) method for the direct synthesis of acid‐base bifunctional UiO‐66 catalysts grafted to modified polyvinylidene fluoride (PVDF). Firstly, PVDF was modified by dopamine hydrochloride (PDA) in trimethylol aminomethane (tris) buffer, named as PDA@PVDF. Secondly, UiO‐66 material was produced via the coordination of organic ligands with zirconium ions, and could be directly loaded onto PDA@PVDF. Moreover, MHT synthetic approach can be used to synthesize other identical structures MOFs with acid, base and acid‐base catalysts by adjusting the ratio of monosodium 2‐sulfoterephthalate and/or 2‐aminoterephthalic. The obtained materials were characterized, and the catalytic performances of glucose to 5‐hydroxymethylfurfural (5‐HMF) have been evaluated. The developed facile reaction system with UiO‐66 MOFs catalysts offers a new route to large‐scale economical viable processes of carbohydrates conservation to 5‐HMF.
Synthesis of Gemini‐QA N‐Chloramine Biocides for Antibacterial Applications
Authors: Li Lingdong , Wang Hande , Jia Dongxue , Wang Pengfei 
Published: December 2019

AbstractGemini‐quaternary ammonium (QA) N‐chloramines were synthesized by covalently bonding two N‐chloramine units via a Gemini‐QA core with varied alkyl linkers. Preliminary antibacterial tests showed that Gemini‐QA N‐chloramine exerted superior biocidal efficacy in contrast to previous developed QA N‐chloramine counterpart probably by means of “team effort” contact killings. Futhermore, the analog with linker of ‐(CH2)10‐ exhibited the highest antibacterial efficacy probably caused by its favorable membrane penetration. This work may provide vital references to develop multi‐cationic N‐chloramines with even higher biocidal activity, which may be indispensable for combateing with bacteria resiatance.
Thermal Performance and Interfacial Aspects of Kaolinite‐Based Stearic Acid Composite in the Presence of Nitric Acid
Authors: Li Jianwen , Yang Huaming , Zuo Xiaochao , Zhao Xiaoguang , Tang Aidong , Li Daokui , Chen Deliang 
Published: December 2019

AbstractThe effect of nitric acid on the thermal performance of stearic acid/kaolinite (SA/Kaol) composite phase change materials (PCMs) was studied. SA/Kaol was subjected to HNO3 manipulations at different acidity conditions. The results indicated that inferior thermal properties were detected at the acid‐treated composites with pH < 2. The latent heat value of SA/Kaol‐0.5 demonstrated an obvious reduction of about 30% compared with that of SA/Kaol, and its supercooling extent could reach as many as 11.2 °C while that of SA/Kaol was only 1.4 °C. Based on interfacial reaction analysis, the reduced crystallinity of SA should be attributed to the confinement effect originated from acid molecular clusters, while the supercooling behavior was caused by external ions. These ions could hinder SA molecules from adsorbing to the surface of crystal nucleus and thus delay the solidification process. As a result of segregation effect, the latent heat value of acid‐treated samples was deteriorated but the supercooling extent was relieved during thermal cycles. This work was the first that reported the effect of nitrogen oxides on PCMs. We believe that the results could play an enlightening role in the stability study of thermal property during PCMs practical applications.
Isotopic Oxygen Exchange between CeO2 and O2: A Heteroexchange Mechanism
Authors: Han Jun , Chen Dandan , Zhu Jun 
Published: December 2019

AbstractIsotopic oxygen exchange (IOE) is a crucial reaction required in the purification of 238PuO2 which has been used as an important fuel in space exploration. Experimental studies on the IOE between 238PuO2 and O2 are costly and hazardous due to the radioactivity. With extremely similar crystal structures, CeO2 could be a fair surrogate for 238PuO2 in the investigation of physicochemical properties. Here, we perform density functional theory calculations to simulate the IOE between CeO2 and O2, wherein a heteroexchange mechanism is proposed. Estimated reaction barriers for CeO2/O2 and 238PuO2/O2 systems are comparable (25.8 and 29.3 kcal mol−1 respectively), indicating CeO2 is a potential substitute for 238PuO2 in an IOE reaction. Our study could be useful for experimental chemists to probe more complicated IOE mechanisms for both CeO2/O2 and PuO2/O2.
Rechargeable High‐Capacity Aluminum‐Nickel Batteries
Authors: Du Yiqun , Zhao Shimeng , Li Jialin , Chen Haixia , Xu Cheng , Zhang Wenyang , Li Pan , Jin Huixin , Zhang Youjian , Zhang Jianxin 
Published: December 2019

AbstractIn this paper, we designed a novel rechargeable Al−Ni battery. Nickel foil was firstly used as a cathode material for aluminum batteries and realized a reversible electrode reaction in a weak Lewis acidic electrolyte. Al−Ni battery can provide a high discharge capacity of more than 0.4 mA h cm−2 and exhibit excellent stability. Furthermore, the electrode reaction mechanism and proposed reasonable reaction equations of Al−Ni battery was studied deeply. We also explored the failure process of Al−Ni batteries and obtained the composition of side reaction products. This Al−Ni battery could offer a high reversible capacity of 0.66 mA h at a current density of 0.5 mA cm−2. Even at 1 mA cm−2, it still delivers a capacity of 0.415 mA h (0.27 mA h cm−2) after 100 cycles.