bluuebunny/crossref_metadata_2025 huggingface dataset:
Ethical Code and its Influence on the Employees’ Perception of Organizational Social Responsibility
Authors: Mijatov Maja , Dragin Aleksandra S. , Stojanović Vladimir , Ivkov Džigurski Anđelija , Nedeljković Knežević Milena , Košić Kristina
Published: August 2021

Research Question: The research is oriented towards determining implementation of the ethical code in hotels, located within the National Park of Serbia, Kopaonik, and its effects on perception of organisational social responsibility dimensions among the hotel employees. Motivation: Application of the ethical code is the first step towards clarifying the standards of acceptable business practices to various stakeholders of the organization, including the employees (Supanti, Butcher, & Fredline, 2015). In this regard, this research is focused on identifying the manners in which the application and content of the ethical code can affect the perception of social responsibility. Idea: The ethical code and public discussion with employees on topics in the field of ethics might affect the perception of employees regarding the organisational social responsibility. In this way, it could contribute to development and strengthening of employees' awareness of the problems of the wider community, as well as business activities that might endanger or help society to overcome these specific problems. Besides, the idea was to research into the implementation of these ethical issues in the business operations in the National Park. Data and Tools: The survey research was conducted within popular tourism destination in Serbia, Kopaonik, on the sample of 211 hotel employees. Findings: The research results show that application of the ethical code shapes the perception of Legal and Economic dimension of organisational social responsibility. Also, the research results indicate the fact that the form in which the ethical code is applied shapes the employees’ perception of philanthropic, legal, economic and ethical dimensions of organisational social responsibility. In addition, results of the research indicate that the usage of the ethical code, as a means of information, shapes the employees’ perception of legal and ethical dimension of organisational social responsibility, while the organization of meetings on ethical issues shapes the employees’ perception of philanthropic dimension of organisational social responsibility. Contribution: The research results might have scientific and practical application as guidelines for improving the business performance in the operation of numerous organizations in the field of tourism, primarily in hotels, but also among the others in the tertiary sector.
Aquafarming and Its Impact on Rural Communities of Bangladesh
Authors: Kabir Md. Shajahan , Hossain Md. Mubarack , Morshed Monzur , Moon Monira Parvin , Rukanuzzaman . , Hasan Md. Mehedi
Published: August 2021

The study was conducted to evaluate the impact of aquafarming on rural communities particularly on the fishermen in terms of socio-economic condition in some selected area of Muktagacha upazila in Mymensingh district of Bangladesh. For collection of data through participatory rural appraisal (PRA) tools with a well-structured questionnaire from July to December, 2017 a total of sixty fishermen were selected randomly. Twelve livelihood aspects of fishers were selected and Pearson's product moment correlation coefficient (r) was used to evaluate the changes of socio-economic status. The findings of the study revealed that through aquaculture majority of the respondents about 58.3% moderately changed their livelihood status, while 31.7% reached higher level and only 10% of the respondents were under lower level. Out of twelve selected livelihood aspects seven were positively correlated but four of them had no relationship with their changing livelihood pattern through aquafarming. The survey identified that fishermen faced various problems such as social, economic and technical. Mostly lack of capital, illiteracy on fish farming, unawareness on health, vulnerability and few institutional supports were the main constraints in their upliftment. The findings of the research revealed that aquafarming resolutely contributing for the development of socio-economic condition of fishers in the explored area and recommended that GOs, NOGs and stakeholders should take more steps for sustainable development.
In Silico ADME/T Properties of Quinine Derivatives using SwissADME and pkCSM Webservers
Authors: Mvondo Jean Gonfi M. , Matondo Aristote , Mawete Dani T. , Bambi Sylvie-Mireille N. , Mbala Blaise M. , Lohohola Pierre O.
Published: August 2021

Aim: Malaria is among the most devastating and widespread tropical parasitic diseases. To overcome antimalarial drug resistance, new drugs need to be developed. This study is designed to establish the pharmacokinetic profile and toxicity of nine quinine derivatives as potential antimalarial drugs using in silico approaches by SwissADME and pkCSM.

Methodology: The structures of investigated compounds were translated into canonical SMILES format and then submitted to SwissADME web tool that gives free access to physicochemical properties, pharmacokinetics, drug-likeness and medicinal chemistry friendliness of compounds, and pkCSM webserver for predicting and optimizing pharmacokinetic and toxicity properties.

Results: SwissADME mainly used to predict the physicochemical properties of compounds and their drug-likeness revealed that all quinine derivatives have good bioavailability and satisfied the Lipinski’s rule of five. The pkCSM results on the absorption, distribution, metabolism, excretion and toxicity show  that all investigated compounds have a good pharmacokinetic profile and they are safe since they belong to class 4 of the Globally Harmonized System (300 < Category 4 ≤ 2000 mg/kg/day).

Conclusion: Drug-likeness and ADME/T predictions of nine investigated quinine derivatives revealed that they are good candidates to oral drug formulation and thus they can be used in a broader context of overcoming the development of resistance by Plasmodium protozoans against most of the drugs currently used to treat malaria. As future prospects, further studies on bioevaluation of compounds are needed to elucidate their potential pharmacological activities.
Magnetic Resonance Imaging with Diffusion Tractography in Assessment of Cerebral Lesions Affecting the Optic Radiations
Authors: El-Ganainy Nayera Mohamed , Radwan Samah Ahmed , El-Gamal Ehab Mohamed , Sherif Mohamed Fouad
Published: August 2021

Background: The combination of Functional magnetic resonance imaging with Diffusion Tensor Imaging has proven scientific and clinical relevance. By measuring the directed provides complementary information on white matter architecture, i.e., on the course and integrity of functionally important white matter tracts. In the diffusion of protons along myelinated fibers, Diffusion Tensor neuroimaging research is mainly applied to study the human brain's structural connectivity, whereas diffusion tensor tractography is often also employed for clinical applications. Diffusion Tensor Imaging measurements can be obtained together with Functional magnetic resonance imaging in the same scanning session, which gives an even more complete picture of each patient's brain. This study aimed to assess cerebral lesions affecting optic radiations by magnetic resonance imaging with diffusion tensor imaging tractography.

Methods: Our prospective study was conducted on 30 cases ages ranged from 17-83 years, 10 of them were normal and considered as the control group and 20 patients were presented with clinical neurological symptoms and signs associated with visual abnormalities.

Results: There is a significant difference between the Fractional anisotropy difference and difference ratio between the two groups with a p-value of 0.016 and 0.017 respectively. There was a strong significant positive correlation between Fractional anisotropy difference ratio (%) and tractography; r = 0.716 (95% confidence interval: 0.470 - 0.858) and p-value <0.001. We correlated the pathological types with different patterns of tractography. optic radiations fiber tracts were displaced in 83.3% of benign tumors and infiltrated in 16.3%. while in malignant tumors optic radiations fiber tracts were displaced in 75%, infiltrated in 12.5%, and disrupted in 25%. There is no "gold standard" for in vivo tractography. Diffusion Tensor Imaging is the only method that permits the calculation and visualization of fiber tracts trajectories in vivo.

Conclusions: Diffusion Tensor Imaging tractography is clinically feasible and provides useful information regarding the site of optic radiations and their affection by different brain lesions also, surgical strategy for lesions located in eloquent visual areas. Also, there was a strong significant positive correlation between Fractional anisotropy difference ratio (%) and tractography distribution. Also, probabilistic multifiber tractography applied to diffusion Magnetic resonance imaging data acquired at 3T may be better as it can cope with crossing and kissing fibers than deterministic models because it allows many more possible local pathway orientations for each Diffusion Tensor Imaging sample point.
Learning Domain Invariant Representation via Self-Rugularization
Authors: Hyun Jaeguk , Lee ChanYong , Kim Hoseong , Yoo Hyunjung , Koh Eunjin
Published: August 2021

Unsupervised domain adaptation often gives impressive solutions to handle domain shift of data. Most of current approaches assume that unlabeled target data to train is abundant. This assumption is not always true in practices. To tackle this issue, we propose a general solution to solve the domain gap minimization problem without any target data. Our method consists of two regularization steps. The first step is a pixel regularization by arbitrary style transfer. Recently, some methods bring style transfer algorithms to domain adaptation and domain generalization process. They use style transfer algorithms to remove texture bias in source domain data. We also use style transfer algorithms for removing texture bias, but our method depends on neither domain adaptation nor domain generalization paradigm. The second regularization step is a feature regularization by feature alignment. Adding a feature alignment loss term to the model loss, the model learns domain invariant representation more efficiently. We evaluate our regularization methods from several experiments both on small dataset and large dataset. From the experiments, we show that our model can learn domain invariant representation as much as unsupervised domain adaptation methods.
Analysis of Probability Distribution of Muzzle Velocity for Chrome Plated Barrel
Authors: Kim Jaekab , Kim Jaehoon
Published: August 2021

To confirm the change of muzzle velocity and the most suitable probability distribution model of the 155 mm K9 howitzer barrel with chrome plating and changed rifling. Using a statistical program, the muzzle velocity were plotted on a normal distribution, a 2-parameter and 3-parameter Weibull distribution on a probability paper. Also, statistical parameters were estimated and muzzle velocity fitness test and probability of K676 charge were plotted. In both the chrome-plated with standard rifling and changed rifling for K9 barrel, the 2-parameter and 3-parameter Weibull distribution were skewed to the left compared to the normal distribution. It was confirmed that the muzzle velocity of the K9 barrel with chromium-plated is suitable for the normal distribution and 3-parameter Weibull distribution model.
A Study on the Submarine Air Independent Propulsion System: Focused on Submarines Currently in Operation
Authors: Jang Junseop
Published: August 2021

Submarines are weapons systems that have been proven to be useful in battle since World War I and have continued to improve the efficiency of propulsion systems in order to be used efficiently on the battlefield. In particular, countries that unable to utilize nuclear propulsion systems make efforts to increase the efficiency of Air Independent Propulsion systems, and typical examples are fuel cells, Stirling engines and MESMA. It is also expected that the development of new propulsion systems such as hydrogen-reformer fuel cells, metal-air fuel cell and direct combustion propulsion systems will continue, so the characteristics of these will be examined and the performance based on the published data be checked in this thesis.
Prediction of Yawing Moment for a Hand-Launched UAV Considering Interference Effect of Propeller Wake
Authors: Park Ji-Min , Kim Dong-Hyun , Park Hyung-Ju
Published: August 2021

In this paper, three-dimensional unsteady computational fluid dynamic(CFD) analyses based on overset grid technique have been performed for a hand-launched unmanned aerial vehicle(UAV) considering the wake effect generated by a rotating propeller. In addition, the defection of rudder is considered in order to consider to predict the equilibrium condition of yawing moment during cruise flight conditions. It is importantly shown in this paper that the wake interference effect of the propeller is significant to accurately predict the yawing moment of the UAV and the yawing moment coefficient corresponding to a flight speed can be different because of its different amount of wake effect due to the different rotating speed of the propeller.
Relationship between personal-sampled air lead and blood lead in low-lead-exposure workers in Japan to apply multiple regression models determining permissible air lead concentration
Authors: Ono Akira , Horiguchi Hyogo
Published: August 2021

Objectives

We investigated the relationship between lead in air (Pb-A) measured by personal sampling and blood lead (Pb-B) in workers with relatively low lead exposure to estimate the permissible air concentration of lead corresponding to the biological tolerance value of Pb-B of 15 µg/dL.

Methods

We collected air samples at a lead-acid battery factory in Japan by personal sampling devices attached to 32 workers (19 males and 13 females) and measured Pb-A by a graphite furnace atomic absorption spectrophotometer in 2017-2020. In addition, we collected information on age, smoking habits, Pb-B, and urinary δ-aminolevulinic acid from the records of medical examinations for lead poisoning. Samples were collected two times from four workers, resulting in 36 data sets.

Results

Before analyses, we excluded four inappropriate data sets. The levels of Pb-A in the factory and Pb-B in the workers were almost under the current permissible limits. Multiple regression models showed significant correlations between Pb-B and Pb-A, and sex, and borderline significance between Pb-B and age. Based on them, we calculated Pb-A corresponding to Pb-B 15 μg/dL, and obtained similar values to the current occupational exposure limit (OEL) of 30 μg/m3, with slight variation between sex and age.

Conclusion

These results validate OEL, although supplementary conditions in terms of sex and age may be necessary.
How does CBCT reconstruction algorithm impact on deformably mapped targets and accumulated dose distributions?
Authors: Mao Weihua , Liu Chang , Gardner Stephen J. , Elshaikh Mohamed , Aref Ibrahim , Lee Joon K. , Pradhan Deepak , Siddiqui Farzan , Snyder Karen Chin , Kumarasiri Akila , Zhao Bo , Kim Joshua , Li Haisen , Wen Ning Winston , Movsas Benjamin , Chetty Indrin J.
Published: August 2021

Purpose

We performed quantitative analysis of differences in deformable image registration (DIR) and deformable dose accumulation (DDA) computed on CBCT datasets reconstructed using the standard (Feldkamp‐Davis‐Kress: FDK_CBCT) and a novel iterative (iterative_CBCT) CBCT reconstruction algorithms.

Methods

Both FDK_CBCT and iterative_CBCT images were reconstructed for 323 fractions of treatment for 10 prostate cancer patients. Planning CT images were deformably registered to each CBCT image data set. After daily dose distributions were computed, they were mapped to planning CT to obtain deformed doses. Dosimetric and image registration results based CBCT images reconstructed by two algorithms were compared at three levels: (A) voxel doses over entire dose calculation volume, (B) clinical constraint results on targets and sensitive structures, and (C) contours propagated to CBCT images using DIR results based on three algorithms (SmartAdapt, Velocity, and Elastix) were compared with manually delineated contours as ground truth.

Results

(A) Average daily dose differences and average normalized DDA differences between FDK_CBCT and iterative_CBCT were ≤1 cGy. Maximum daily point dose differences increased from 0.22 ± 0.06 Gy (before the deformable dose mapping operation) to 1.33 ± 0.38 Gy after the deformable dose mapping. Maximum differences of normalized DDA per fraction were up to 0.80 Gy (0.42 ± 0.19 Gy). (B) Differences in target minimum doses were up to 8.31 Gy (−0.62 ± 4.60 Gy) and differences in critical structure doses were 0.70 ± 1.49 Gy. (C) For mapped prostate contours based on iterative_CBCT (relative to standard FDK_CBCT), dice similarity coefficient increased by 0.10 ± 0.09 (p < 0.0001), mass center distances decreased by 2.5 ± 3.0 mm (p < 0.00005), and Hausdorff distances decreased by 3.3 ± 4.4 mm (p < 0.00015).

Conclusions

The new iterative CBCT reconstruction algorithm leads to different mapped volumes of interest, deformed and cumulative doses than results based on conventional FDK_CBCT.
Ultralight Metamaterial for Sound Absorption Based on Miura‐Ori Tessellation Structures
Authors: Wang Yixin , Guo Jingwen , Fang Yi , Zhang Xin , Yu Hongyu
Published: August 2021

Herein, electrospinning and paper folding (i.e., origami) techniques are integrated to fabricate a novel ultralight metamaterial for sound absorption based on Miura‐ori tessellation structure, which exists at an extremely low mass density of only 10.64 mg cm−3. Sound absorption tests using an impedance tube demonstrate a significant improvement of sound absorption coefficient and the shift of first resonance absorption frequency to the lower band compared with the plane membrane. Further, the effect on sound absorption performance from three important parametersγ,θ, andathat dominate the shape of Miura‐ori are investigated and understood through the membrane vibration mechanism and Johnson–Alard hard frame model. Meanwhile, to achieve good sound absorption in a broad frequency range, a stacked structure with the double‐cavity‐double‐sandwich model is created, which presents a superior broadband sound absorption and ideal sound absorption in a specific frequency range.
Tuning Mechanical and Electrical Properties of Elastomer Composites with Hybrid Filler Network Containing Graphene for Stretchable Strain Sensors
Authors: Ke Kai , Sang Zhen , Chen Xiaoyi , Rohm Kristen , Manas-Zloczower Ica
Published: August 2021

Conductive elastomer composites (CECs) with segregated filler networks display a combination of good mechanical properties and electrical conductivity, enabling potential applications in flexible and stretchable electronics. However, it is challenging to achieve high strain sensitivity and to retain good elasticity. Here, hybrid fillers of carbon nanostructures (CNS, also known as branched carbon nanotubes) and graphene are used to achieve high strain sensitivity of thermoplastic polyurethane (TPU)‐based CECs without decreasing elasticity and electrical conductivity. By changing the graphene type, namely, single layer graphene nanosheet (GNS) and graphene nanoplatelets (GNP), mechanical properties and strain–sensing performances of the CECs can be modulated effectively at proper hybrid filler compositions. Due to the effect of graphene morphology, the TPU/CNS–GNP system has higher strain sensitivity by comparison with the TPU/CNS–GNS system. These CECs demonstrate potential applications as flexible/wearable electronics in body joint bending and flexible switches and resistors for current regulation.
Visualizing Quasi‐Static Electric Fields with Flexible and Printed Organic Transistors
Authors: Shoji Itsuki , Wada Hideki , Uto Kodai , Takeda Yasunori , Sugimoto Toshiyuki , Matsui Hiroyuki
Published: August 2021

Unlike electromagnetic radiation such as radio waves, infrared‐visible‐ultraviolet, and X‐rays, static or quasi‐static electric fields are rarely utilized for visualization in people's lives and industries. The difficulty in measuring quasi‐static electric fields is mainly due to low‐energy photons and the lack of integrable devices with high sensitivity to detect them. Here, a novel quasi‐static electric field sensor based on a floating extended gate organic field‐effect transistor is shown, which is highly sensitive, integrable as an array, ultra‐flexible, highly expandable, and digitally printable. The sensor has a thickness of ≈2 µm and can detect the proximity to human hands with low static electricity at a distance of tens of centimeters. The sensor can provide a new vision of electric charges, proximity sensing capability, and, in the future, a noncontact method for measuring biological activities such as brain waves.
Model‐based design of experiments for polyether production from bio‐based 1,3‐propanediol
Authors: Vo Anh‐Duong Dieu , Shahmohammadi Ali , McAuley Kimberley B.
Published: August 2021

Sequential model‐based design of experiments (MDBOE) accounts for information from previous experiments when selecting conditions for new experiments. In the current study, sequential MBDOE is used to select operating conditions for experiments in a batch‐reactor that produces bio‐based polytrimethylene ether glycol (PO3G). These Bayesian A‐optimal experiments are designed to obtain improved estimates of 70 fundamental‐model parameters, while accounting for industrial data from eight previous runs. Settings are selected for three decision variables: reactor temperature, initial catalyst level, and initial water concentration. If only one new experiment is conducted, it should be run at high temperature, with relatively high concentrations of catalyst and initial water. When two new runs are conducted, one should use an intermediate catalyst concentration. The effectiveness of the proposed MBDOE approach is tested using Monte‐Carlo simulations, revealing that the selected experiments are superior compared to experiments selected randomly from corners of the permissible design space.
Compositional and kinetic study of thermal degradation of kerogen using TG‐FTIR, NMR, and microscopic study
Authors: Baruah Bhargav , Tiwari Pankaj
Published: August 2021

Understanding the thermal maturation mechanism of kerogen has both industrial and scientific significance. Here, kerogen extracted from Indian oil shale of Upper Assam basin is subjected to TG‐FTIR analysis to study the thermal decomposition behavior of isolated kerogen and compared with oil shale sample. Kinetic study of kerogen was performed on thermogravimetric data using isoconversional methods. The mean apparent activation energy values were found in the range of 219 to 236 kJ/mol. The reaction models were identified as first‐order and A2 nucleation models. The obtained kinetic parameters were validated by reconstruction of conversion profiles. Comparison of oil derived from kerogen with shale oil, and solvent‐extracted bitumen using NMR analysis showed that kerogen initially matures into bitumen, and thereafter, gets converted to oil and gas in the presence of inherent minerals. The predicted degradation mechanisms of kerogen from the parent oil shale sample were examined using microscopic study.
Ionic Liquid Functionalized Gel Polymer Electrolytes for Stable Lithium Metal Batteries
Authors: Zhou Tianhong , Zhao Yan , Choi Jang Wook , Coskun Ali
Published: August 2021

Metallic lithium (Li) is regarded as the ideal anode material in lithium‐ion batteries due to its low electrochemical potential, highest theoretical energy density and low density. There are, however, still significant challenges to be addressed such as Li‐dendrite growth and low interfacial stability, which impede the practical application of Li metal anodes. In order to circumvent these shortcomings, herein, we present a gel polymer electrolyte containing imidazolium ionic liquid end groups with a perfluorinated alkyl chain (F‐IL) to achieve both high ionic conductivity and Li ion transference number by fundamentally altering the solubility of salt within the gel electrolyte through Lewis‐acidic segments in the polymer backbone. Moreover, the presence of F‐IL moieties decreased the binding affinity of Li cation towards the glycol chains, enabling a rapid transfer of Li cation within the gel network. These structural features enabled the immobilization of anions on the ionic liquid segments to alleviate the space‐charge effect while promoting stronger anion coordination and weaker cation coordination in the Lewis‐acidic polymers. Accordingly, we realized a high Li ion conductivity (9.16×10−3 S cm−1) and high Li ion transference number of 0.69 simultaneously, along with a good electrochemical stability up to 4.55 V, while effectively suppressing Li dendrite growth. Moreover, the gel polymer electrolyte exhibited stable cycling performance of the Li|Li symmetric cell of 9 mAh cm−2 for more than 1800 hours and retained 86.7 % of the original capacity after 250 cycles for lithium‐sulfur (Li‐S) full cell.
Identifizierung von RNA‐Basenpaaren und vollständige Zuordnung von Nukleobasen‐Resonanzen durch Protonen‐detektierte Festkörper‐NMR‐Spektroskopie bei MAS Geschwindigkeiten von 100 kHz
Authors: Aguion Philipp Innig , Kirkpatrick John , Carlomagno Teresa , Marchanka Alexander
Published: August 2021

Die Aufklärung von RNA Strukturen, entweder in Isolation oder im Komplex, ist essentiell, um die Mechanismen zellulärer Prozesse zu verstehen. Festkörper‐NMR ist auf Komplexe mit hohem Molekulargewicht anwendbar und benötigt keine Kristallisation; Die Methode ist daher gut geeignet um RNA als Teil von großen mehrkomponentigen Komplexen zu untersuchen. Kürzlich konnten wir die ersten Strukturen von RNA und einem RNA‐Protein Komplex mittels Festkörper‐NMR durch die Anwendung von konventioneller 13C‐ und 15N‐Detektion lösen. Dieser Ansatz ist durch diverse RNA Peak‐Überlappungen und die niedrige Intensität von multidimensionalen Experimenten limitiert. In dieser Arbeit überwinden wir die Limitationen in Sensitivität und Auflösung durch die Anwendung von 1H‐Detektion bei schnellen MAS Geschwindigkeiten. Wir entwickeln Experimente, die die Identifizierung von vollständigen Spinsystemen der Nukleobasen zusammen mit derer Nukleotid‐spezifischer Basenpaarung ermöglichen. Diese Experimente benötigen weniger als ein Milligramm einer uniform Isotopen‐markierten RNA Probe und erlauben die schnelle Bestimmung der RNA Sekundärstruktur durch Festkörper‐NMR in Protein‐RNA Komplexen jedweder Größe.
Microporous Carbon Nitride (C3N5.4) with Tetrazine based Molecular Structure for Efficient Adsorption of CO2 and Water
Authors: Sathish CI , Premkumar S. , Chu Xueze , Yu Xiaojiang , Breese Mark B. H. , Al‐Abri Mohammed , Al‐Muhtaseb Ala'a H. , Karakoti Ajay , Yi Jiabao , Vinu Ajayan
Published: August 2021

Mesoporous carbon nitrides with C3N5 and C3N6 stoichiometries created a new momentum in the field of organic metal‐free semiconductors owing to their unique band structures and high basicity. Here, we report on the preparation of a novel graphitic microporous carbon nitride with a tetrazine based chemical structure and the composition of C3N5.4 using ultra‐stable Y zeolite as the template and aminoguanidine hydrochloride, a high nitrogen‐containing molecule, as the CN precursor. Spectroscopic characterization and density functional theory calculations reveal that the prepared material exhibits a new molecular structure, which comprises two tetrazines and one triazine rings in the unit cell and is thermodynamically stable. The resultant carbon nitride shows an outstanding surface area of 130.4 m2 g−1 and demonstrates excellent CO2 adsorption per unit surface area of 47.54 μmol m−2, which is due to the existence of abundant free NH2 groups, basic sites and microporosity. The material also exhibits highly selective sensing over water molecules (151.1 mmol g−1) and aliphatic hydrocarbons due to its unique microporous structure with a high amount of hydrophilic nitrogen moieties and recognizing ability towards small molecules.
Stabilizing Transition Metal Vacancy Induced Oxygen Redox by Co2+/Co3+ Redox and Sodium‐Site Doping for Layered Cathode Materials
Authors: Li Xun‐Lu , Bao Jian , Shadike Zulipiya , Wang Qin‐Chao , Yang Xiao‐Qing , Zhou Yong‐Ning , Sun Dalin , Fang Fang
Published: August 2021

Anionic redox is an effective way to boost the energy density of layer‐structured metal‐oxide cathodes for rechargeable batteries. However, inherent rigid nature of the TMO6 (TM: transition metals) subunits in the layered materials makes it hardly tolerate the inner strains induced by lattice glide, especially at high voltage. Herein, P2‐Na0.8Mg0.13[Mn0.6Co0.2Mg0.07□0.13]O2 (□: TM vacancy) is designed that contains vacancies in TM sites, and Mg ions in both TM and sodium sites. Vacancies make the rigid TMO6 octahedron become more asymmetric and flexible. Low valence Co2+/Co3+ redox couple stabilizes the electronic structure, especially at the charged state. Mg2+ in sodium sites can tune the interlayer spacing against O‐O electrostatic repulsion. Time‐resolved in situ X‐ray diffraction confirms that irreversible structure evolution is effectively suppressed during deep desodiation benefiting from the specific configuration. X‐ray absorption spectroscopy (XAS) and density functional theory (DFT) calculations demonstrate that, deriving from the intrinsic vacancies, multiple local configurations of “□‐O‐□”, “Na‐O‐□”, “Mg‐O‐□” are superior in facilitating the oxygen redox for charge compensation than previously reported “Na‐O‐Mg”. The resulted material delivers promising cycle stability and rate capability, with a long voltage plateau at 4.2 V contributed by oxygen, and can be well maintained even at high rates. The strategy will inspire new ideas in designing highly stable cathode materials with reversible anionic redox for sodium‐ion batteries.
Mechanistic Insights into the Formation of the 6,10‐Bicyclic Eunicellane Skeleton by the Bacterial Diterpene Synthase Bnd4
Authors: Xu Baofu , Tantillo Dean J. , Rudolf Jeffrey D.
Published: August 2021

The eunicellane diterpenoids are a unique family of natural products seen in marine organisms, plants, and bacteria. We used a series of biochemical, bioinformatics, and theoretical experiments to investigate the mechanism of the first diterpene synthase known to form the eunicellane skeleton. Deuterium labeling studies and quantum chemical calculations support that Bnd4, from Streptomyces sp. (CL12‐4), forms the 6,10‐bicyclic skeleton through a 1,10‐cyclization, 1,3‐hydride shift, and 1,14‐cyclization cascade. Bnd4 also demonstrated sesquiterpene cyclase activity and the ability to prenylate small molecules. Bnd4 possesses a unique D94NxxxD motif and mutation experiments confirmed an absolute requirement for D94 as well as E169.
Enabling the Use of Alkyl Thianthrenium Salts in Cross‐Coupling Reactions by Copper Catalysis
Authors: Chen Cheng , Wang Minyan , Lu Hongjian , Zhao Binlin , Shi Zhuangzhi
Published: August 2021

Alkyl groups are one of the most widely used groups in organic synthesis. Here, a a series of thianthrenium salts have been synthesized that act as reliable alkylation reagents and readily engage in copper‐catalyzed Sonogashira reactions to build C(sp3)−C(sp) bonds under mild photochemical conditions. Diverse alkyl thianthrenium salts, including methyl and disubstituted thianthrenium salts, are employed with great functional breadth, since sensitive Cl, Br, and I atoms, which are poorly tolerated in conventional approaches, are compatible. The generality of the developed alkyl reagents has also been demonstrated in copper‐catalyzed Kumada reactions.
Photocatalytic selective oxidation of HMF to DFF over Bi2WO6/mpg–C3N4 composite under visible light
Authors: Cheng Lili , Huang Danyao , Zhang Yun , Wu Ying
Published: August 2021

Bi2WO6/mpg–C3N4 composite catalyst was prepared by hydrothermal method and applied in the partial oxidation of HMF to DFF by photocatalytic approach. The 12% Bi2WO6/mpg–C3N4 composite exhibits the highest catalytic performance, with the HMF conversion of 59.3% and the DFF selectivity of 84.3% after 6 h. This may be primarily ascribed to the synergetic effect of Bi2WO6 and mpg–C3N4 on photogenerated charges separation through the charge transfer between the two semiconductors. Based on the reactive species trapping experiment, it is concluded that ·O2− plays a significant part to convert HMF into DFF and the electron–hole separation follows a Z‐scheme mechanism.
Silver nanoparticles supported on smart polymer microgel system for highly proficient catalytic reduction of Cr+6 to Cr+3 with formic acid
Authors: Hussain Iftikhar , Ali Faisal , Shahid Muhammad , Begum Robina , Irfan Ahmad , Wu Weitai , Shaukat Saadia , Farooqi Zahoor H.
Published: August 2021

Poly(styrene@N‐isopropylmethacrylamide‐methacrylic acid) [P (St‐NM)] microgels were prepared via seed facilitated emulsion polymerization process. In situ reduction of silver ions was carried out to generate Ag nanoparticles in the voids of shell region of polymer microgels. Synthesized P (St‐NM) and Ag‐P (St‐NM) particles were characterized by UV–Vis spectroscopy, transmission electron microscopy (TEM), Fourier‐transformed infrared spectroscopy (FTIR), and X‐ray diffraction (XRD). The stability of Ag nanoparticles within P (St‐NM) system over the wide range of pH and temperature is also a part of this study. Thus, prepared Ag‐P (St‐NM) was tested for its catalytic efficiency against reduction of K2Cr2O7 using formic acid (FA) as reductant. Factors affecting catalytic efficiency of Ag‐P (St‐NM) system towards transformation of Cr+6 to Cr+3 were investigated. Other toxic chemicals can also be reduced using same catalytic system.
Preliminary evidence of an endangered species benefiting from moderate climate warming: A palaeolimnological study of the charophyte Lychnothamnus barbatus
Authors: Brzozowski Michał , Kowalewski Grzegorz , Szczuciński Witold , Kaczmarek Lech , Pełechaty Mariusz
Published: August 2021

In a time of rapid environmental changes, identification of the effects of climate warming on charophytes (Characeae, Charophyta) will enable the optimization of conservation measures, especially for extremely rare species. Lychnothamnus barbatus is one of the rarest charophytes worldwide, which has decreased in the number of occupied sites over the last century. However, the recolonization of former sites has been observed in recent years (e.g. Lake Kuźnickie, Poland). The study aimed to analyse the effects of climatic changes and human pressure on the L. barbatus population.

Three 30 cm sediment cores were collected from minimum, average, and maximum depths of L. barbatus occurrence to determine the past vegetation composition. Sediment cores were dated using the radioisotopes lead‐210, caesium‐137, and carbon‐14. A spatial analysis of the lake catchment changes during the last 120 years was also conducted.

The study demonstrated L. barbatus presence in Lake Kuźnickie at the beginning of the 16th century. However, a sharp increase in the proportion of this species in the vegetation community occurred in the 19th century and during climate warming at the end of the Little Ice Age. Factors that significantly influenced the present occurrence of the L. barbatus population included improvement in water quality and the oospore bank deposited in the bottom sediments.

This study is the first palaeoreconstruction in a modern lake dominated by L. barbatus. Based on the history of L. barbatus in Lake Kuźnickie after the end of the Little Ice Age, the positive effect of climate warming on the contemporary recovery of this charophyte is postulated.

The reaction of L. barbatus to climate warming appears to differ from commonly accepted scenarios for aquatic macrophytes because its recovery in the past and at present coincided with increases in air temperature. This research indicated the appropriate management and conservation practices for lakes with L. barbatus populations.
Diversity of Luminescent Metal Complexes in OLEDs: Beyond Traditional Precious Metals
Authors: Li Xiaoning , Xie Yujun , Li Zhen
Published: August 2021

Organic light‐emitting diodes (OLED) have attracted increasing attention due to their excellent properties, such as self‐luminosity, high color gamut and flexibility, and potential applications in display, wearable devices and lighting. The emitters are the most important composition in OLEDs, mainly classified into fluorescent compounds (first generation), metal phosphorescent complexes (second generation), and thermally activated delayed fluorescence (TADF) materials (third generation). In this review, we summarize the advances of novel emitters of organic metal complexes in the last decade, focusing on coinage metals (Cu, Ag, and Au) and non‐precious metals (Al, Zn, W, and alkali metal). Also, the design strategy of d10 and Au(III) complexes was discussed. We aim to provide guidance for exploring efficient metal complexes beyond traditional phosphorescent complexes.
The Origin of Gaseous Decomposition Products Formed During SEI Formation Analyzed by Isotope Labeling in Lithium‐Ion Battery Electrolytes
Authors: Leißing Marco , Peschel Christoph , Horsthemke Fabian , Wiemers‐Meyer Simon , Winter Martin , Nowak Sascha
Published: August 2021

Interphase formation during the first charge and discharge cycle(s) of a battery cell is among the least understood processes in lithium‐ion batteries (LIBs). The formation of interphases is a result of electrolyte decomposition and accompanied by gassing. The direct analysis of these interphases is challenging and indirect methods are required to obtain information about this process. For example, indirect, ex situ analyses of gaseous decomposition products can help to draw conclusions about occurring reactions in the cell. In this work, the origin of several permanent gases and hydrocarbons (CO, CH4, C2H4 and C2H6) emerging during the formation of LiNi0.6Mn0.2Co0.2O2 (NMC622)||graphite pouch type LIBs equipped with a gas sampling port was investigated. Isotope labeled electrolytes (13C3‐EC, D4‐EC) were used to assign formation gas products to the individual constituents of the electrolyte mixture. The effect of common linear carbonates in combination with ethylene carbonate (EC) as well as the effect of vinylene carbonate (VC) as film forming additive was investigated. The obtained mass spectra from gas chromatography mass spectrometry (GC‐MS) and the mass shift caused by the labeled electrolyte components, enabled an assignment of individual electrolyte components to the resulting gas products. The aim of this work is to gain more information about interphase reactions and thus to improve understanding of the mechanisms behind formation.
Sensitivity and identification quantification by a relative latent model complexity perturbation in Bayesian meta‐analysis
Authors: Roos Małgorzata , Hunanyan Sona , Bakka Haakon , Rue Håvard
Published: August 2021

In recent years, Bayesian meta‐analysis expressed by a normal–normal hierarchical model (NNHM) has been widely used for combining evidence from multiple studies. Data provided for the NNHM are frequently based on a small number of studies and on uncertain within‐study standard deviation values. Despite the widespread use of Bayesian NNHM, it has always been unclear to what extent the posterior inference is impacted by the heterogeneity prior (sensitivity ) and by the uncertainty in the within‐study standard deviation values (identification ). Thus, to answer this question, we developed a unified method to simultaneously quantify both sensitivity and identification (‐) for all model parameters in a Bayesian NNHM, based on derivatives of the Bhattacharyya coefficient with respect to relative latent model complexity (RLMC) perturbations. Three case studies exemplify the applicability of the method proposed: historical data for a conventional therapy, data from which one large study is first included and then excluded, and two subgroup meta‐analyses specified by their randomization status. We analyzed six scenarios, crossing three RLMC targets with two heterogeneity priors (half‐normal, half‐Cauchy). The results show that ‐ explicitly reveals which parameters are affected by the heterogeneity prior and by the uncertainty in the within‐study standard deviation values. In addition, we compare the impact of both heterogeneity priors and quantify how ‐ values are affected by omitting one large study and by the randomization status. Finally, the range of applicability of ‐ is extended to Bayesian NtHM. A dedicated R package facilitates automatic ‐ quantification in applied Bayesian meta‐analyses.
Effect of wheat quality traits and glutenin composition on tortilla quality from the USDA Southern Regional Performance Nursery
Authors: Zhang Pingping , Tilley Michael , Bai Guihua , Harmer Sarah , Duke Sara , Seabourn Bradford W. , Zhang Guorong
Published: August 2021

The popularity of wheat flour tortillas is spreading throughout the world and has become one of the highest‐selling bread products. The USDA Southern Regional Performance Nursery (SRPN) serves as the largest wheat‐growing region in the USA, but the tortilla quality of germplasm in SRPN has remained unknown. This study investigated the kernel and flour quality traits, dough rheological properties, and tortilla quality parameters, and glutenin composition of 131 wheat lines from 1995 to 2007 in SRPN. The high molecular weight glutenin subunits (HMW‐GS) composition and wheat–rye 1RS translocation status of these wheat lines were also detected. A wide variation of wheat and tortilla quality traits was observed among these wheat lines. Association analysis showed that increased protein content and gluten strength significantly decreased the tortilla diameter and improved the tortilla shelf life in terms of 2‐D extensibility parameters (P < .001). The group of wheat lines with acceptable tortilla quality (both diameter >165 mm and day 16 flexibility score >3.0) had medium protein content and dough strength. Compared to wheat lines with 5 + 10 and non‐1RS translocation, those with 2 + 12 and 1RS translocation generally showed lower dough strength and shelf life, and higher tortilla diameter and specific volume (P < 0.01). TAM 302, HBG0358, CO99W192, and CO99534 showed premium tortilla quality with a diameter ≥180 mm and a day 16 flexibility score ≥4.00, which could be used as parents in tortilla wheat breeding program.
Heterogeneous Cobalt‐Catalyzed C−C Bond Cleavage in Alcohols to Carbonyl Compounds
Authors: Teng Jia‐nan , Zhu Rui , Li Xinglong , Fu Yao
Published: August 2021

Cobalt oxide hydrate (Co(OH)x) supported on metal oxides were prepared. The oxidative cleavage of C(OH)−C bond in alcohol was catalyzed by Co(OH)x/metal oxides using molecular oxygen as the oxidant, and the corresponding product was obtained with high selectivity. The composition and characteristics of the catalysts were analyzed by X‐ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), high‐angle ring dark‐field scanning TEM (HAADF‐STEM), N2 physico‐adsorption characterization, inductively coupled plasma optical emission spectrometry (ICP‐OES), Fourier transform infrared spectrum (FTIR), X‐ray photoelectron spectroscopy (XPS) and NH3‐temperature‐programmed desorption (NH3‐TPD). Additionally, a reasonable reaction mechanism was proposed based on the characterization results and a series of controlled experiments. Notably, this heterogeneous catalytic system did not require any additives and had good recycling performance.
The Synthesis of Porous Na3V2(PO4)3 for Sodium‐Ion Storage
Authors: Xiong Hailong , Qi Chunyu , Lv Shiquan , Zhang Ling , Qiao Zhen‐An
Published: August 2021

Na3V2(PO4)3 (NVP) has been regarded as a potential cathode material for sodium‐ion batteries (SIBs) due to its excellent structural stability and rapid Na+ conductivity. However, its electrochemical performances are restricted by the large bulk structure and poor electronic conductivity. The construction of porous NVP materials is a powerful method to improve the electrochemical properties. This concept aims to provide an overview of recent progress of porous NVP materials for SIBs. Herein, the synthetic strategies and formation mechanisms of porous NVP materials as well as the relationship between the porous structures and electrochemical performances of NVP materials are reviewed. Furthermore, the challenges and prospects for the preparation of porous NVP materials in this field are outlined.
Suppression of liquid slugs and phase separation through pipeline bends
Authors: Igbokwe Loveday C. , Naterer Greg F. , Zendehboudi Sohrab , Pedersen Simon , Jespersen Stefan
Published: August 2021

This study examines the suppression of liquid slugs in the transport and separation of multiphase flows in pipelines. Two well‐known slug control approaches are evaluated in this paper. The methods are employed to control and stabilize an undesired and unstable flow regime, optimize flow production, reduce operating costs, and in general, improve overall safety requirements of oil and gas pipelines. Unlike designs with an additional flowline to separate gas upstream, this study shows that active topside choking can suppress slugs and stabilize the system flowrates and pressures without the requirement of separation upstream of the topside valve. Careful choking is required to minimize production losses that can result from excess back pressure. A riser‐based, gas‐lift method reduces system instability and increases production. This study also reveals that negligible improvement in stability is achieved when large volumes of gas are injected. The system shifts into an annular flow regime when the injection is further increased. A large separator may be required to accommodate high gas volumes. This study shows that gas‐lift not coordinated with choking is not effective for slug mitigation through pipeline bends. This paper also presents and discusses new non‐dimensional correlations, including slug control inputs in the pipelines such as choke openings, based on new experimental data.
The effects of luminance contrast and color combination on icon cognitive performance
Authors: Ming Chengye , Wu Zhengxin , Gu Haoran , Chen Chunpeng , Zhang Ying
Published: August 2021

This study explored and identified the effects of luminance contrast and color combinations on icon cognitive performance. A total of 50 participants took part in the experiment. As designed, icon cognitive performance was measured as a function of the following independent variables: 4 levels of luminance contrast, 16 target/background color combinations. Experiment A showed that a luminance contrast of 18:1 provide participants with the highest cognitive performance. Yellow on black, yellow on blue, and white on blue were the three most legible color combinations. To explore the individual effects of luminance contrast and color combination on cognitive performance, in experiment B, the material was decolored. Comparing the reaction time data of experiment A with experiment B, it was found that both luminance contrast and color combination can significantly affect cognitive performance. Under the same luminance contrast, yellow on black, yellow on blue, and white on blue significantly improve the search speed, while green on red, yellow on purple, green on blue, and turquoise on blue significantly slow down the search speed. In experiment C, event related potential technology was used to verify the results of behavioral experiment B. It was found that under 18:1 high luminance contrast visual stimulation, the activation of prefrontal and occipital regions was stronger, and the peak and average amplitude of P100 curve were significantly higher than the other three luminance contrasts. To explain why some color combinations shorten reaction time, in experiment D, peak latency of P100 at visual‐cortex area (O1, O2, OZ) showed significantly faster response time with fast search speed color combinations than with slow search speed color combinations. These results provide some guidance for human–software interface design.