Morphological Evolution of Fe-Oxy-Hydroxide Nanotubes During Electrodeposition

2019 ◽  
Vol 15 (6) ◽  
pp. 669-678
Author(s):  
Patrizia Bocchetta ◽  
Francesca Conciauro ◽  
Filippo Selleri
Keyword(s):  
Morphological Evolution ◽  
Ethanol Solution ◽  
Alcoholic Solution ◽  
Constant Current ◽  
Relative Mass ◽  
Easy Access ◽  
High Quality ◽  
Cathodic Electrodeposition ◽  
Kinetic Growth ◽  
First Time

Background: Ordered arrays of 1D iron(oxyhydr)oxide nanostructures have potential applications in magnetic recording mediums, lithium batteries, supercapacitors, and thermal production of α-, β-, γ-type Fe2O3. Large surface areas with three-dimensional architectures, such as nanotubes, are encouraged because the easy access of ion, gas, liquid and radiation assures high ion exchange capacity, sensing and catalytic activities. Objective: In this work, the morphological evolution of Fe-oxyhydroxide electrodeposition inside AAM pores has been followed for the first time by selecting two relevant electrochemical conditions of synthesis producing high quality morphologies of nanotubes. Methods: Iron(oxyhydr)oxide nanotubes have been synthesized by cathodic electrodeposition at a constant current in classic three-electrode cell. Two different electrolytic baths have been studied: (i) an aqueous bath consisting of 5 mM FeCl3+5 mM KF+0.1 M KCl+1 M H2O2 (H-Fe) and (ii) an ethanolic bath consisting of 0.3 M FeCl3 + 0.1 M KCl (Et-Fe). Results: XRD, Raman and SEM results on the iron(oxyhydr)oxide nanotubes suggest different mechanisms of chemical precipitation mechanisms in Et-Fe alcoholic solution (dehydration and rearrangement within the ferrihydrite aggregates) and H-Fe aqueous solution (dissolution/ reprecipitation). The morphological evolution of the growing nanostructure to nanotubes inside AAM in the two baths agrees very well with the overpotential vs. time curves, the kinetic growth of the nanotubes arrays and a growth mechanism governed by the relative mass transfer processes involving both OH- and Fe ions. Conclusion: The morphological evolution of Fe-oxyhydroxide cathodic electroprecipitation inside AAM pores in two relevant electrochemical baths containing Fe(III) (aqueous/H-Fe and alcoholic/Et- Fe) has been followed for the first time by a comprehensive SEM analysis accompanied by electrochemical, structural and kinetic growth of the nano-electrodeposits. : The detailed SEM results collected in this work allowed to recommend template electrogeneration of base in ethanol solution containing Fe(III) chloride as a relevant procedure to obtain high-quality, compact and well-ordered Fe oxy-hydroxide nanotubes.

Disability as a social phenomenon

2020 ◽  
pp. 22-38
Author(s):  
Natalia Guseva ◽  
Vitaliy Berdutin
Keyword(s):  
Social Protection ◽  
Russian Society ◽  
Stage Model ◽  
High Quality ◽  
Rehabilitation Programs ◽  
Current State ◽  
The Social ◽  
Consistent Solution ◽  
First Time

At present, the problem of establishing disability is a point at issue in Russia. Despite the fact that medical criteria for disability are being developed very actively, high-quality methods for assessing social hallmarks are still lacking. Since disability is a phenomenon inherent in any society, each state forms a social and economic policy for people with disabilities in accordance with its level of development, priorities and opportunities. We have proposed a three-stage model, which includes a system for the consistent solution of the main tasks aimed at studying the causes and consequences of the problems encountered today in the social protection of citizens with health problems. The article shows why the existing approaches to the determination of disability and rehabilitation programs do not correspond to the current state of Russian society and why a decrease in the rate of persons recognized as disabled for the first time does not indicate an improvement in the health of the population. The authors proposed a number of measures with a view to correcting the situation according to the results of the study.

Precursor engineering for high-quality Cs2AgBiBr6 films toward efficient lead-free double perovskite solar cells

2021 ◽  
Author(s):  
Ping Hou ◽  
Wenxiang Yang ◽  
Ning Wan ◽  
Zhi Fang ◽  
Jinju Zheng ◽  
...  
Keyword(s):  
Solar Cells ◽  
Perovskite Solar Cells ◽  
Control Sample ◽  
Double Perovskite ◽  
Lead Free ◽  
High Quality ◽  
Precursor Engineering ◽  
First Time

We report a facile BiBr3(DMSO)2 adduct process to produce high-quality Cs2AgBiBr6 films with large grains for the first time, which leads to an enhancement of over 40% on the PCE of Cs2AgBiBr6-based solar cells compared to that of the control sample.

scholarly journals A Novel and Efficient High-Yield Method for Preparing Bacterial Ghosts

Toxins ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 420
Author(s):  
Yi Ma ◽  
Liu Cui ◽  
Meng Wang ◽  
Qiuli Sun ◽  
Kaisheng Liu ◽  
...  
Keyword(s):  
Large Scale ◽  
Expression System ◽  
High Yield ◽  
Wild Type ◽  
High Quality ◽  
Efficient Protection ◽  
Bacterial Ghosts ◽  
Cell Envelopes ◽  
Extracellular Structures ◽  
First Time

Bacterial ghosts (BGs) are empty cell envelopes possessing native extracellular structures without a cytoplasm and genetic materials. BGs are proposed to have significant prospects in biomedical research as vaccines or delivery carriers. The applications of BGs are often limited by inefficient bacterial lysis and a low yield. To solve these problems, we compared the lysis efficiency of the wild-type protein E (EW) from phage ΦX174 and the screened mutant protein E (EM) in the Escherichia coli BL21(DE3) strain. The results show that the lysis efficiency mediated by protein EM was improved. The implementation of the pLysS plasmid allowed nearly 100% lysis efficiency, with a high initial cell density as high as OD600 = 2.0, which was higher compared to the commonly used BG preparation method. The results of Western blot analysis and immunofluorescence indicate that the expression level of protein EM was significantly higher than that of the non-pLysS plasmid. High-quality BGs were observed by SEM and TEM. To verify the applicability of this method in other bacteria, the T7 RNA polymerase expression system was successfully constructed in Salmonella enterica (S. Enterica, SE). A pET vector containing EM and pLysS were introduced to obtain high-quality SE ghosts which could provide efficient protection for humans and animals. This paper describes a novel and commonly used method to produce high-quality BGs on a large scale for the first time.

Rapid Thermal Oxidation of Lightly Doped Silicon in N2O

1994 ◽  
Vol 342 ◽  
Author(s):  
S.C. Sun ◽  
L.S. Wang ◽  
F.L. Yeh ◽  
T.S. Lai ◽  
Y.H. Lin
Keyword(s):  
Growth Rate ◽  
Thermal Oxidation ◽  
Charge Trapping ◽  
Interface State ◽  
Constant Current ◽  
Mos Capacitor ◽  
Rapid Thermal Oxidation ◽  
Doped Silicon ◽  
State Generation ◽  
First Time

ABSTRACTIn this paper, a detailed study is presented for the growth kinetics of rapid thermal oxidation of lightly-doped silicon in N2O and O2 on (100), (110), and (111) oriented substrates. It was found that (110)-oriented Si has the highest growth rate in both N2O and dry O2, and (100) Si has the lowest rate. There is no “crossover” on the growth rate of rapid thermal N2O oxidation between (110) Si and (111) Si as compared to oxides grown in furnace N2O. Pressure dependence of rapid thermal N2O oxidation is reported for the first time. MOS capacitor results show that the low-pressure (40 Torr) N2O-grown oxides have much less interface state generation and charge trapping under constant current stress as compared to oxides grown in either 760 Torr N2O or O2 ambient.

scholarly journals Unraveling the long-pursued Au144 structure by x-ray crystallography

2018 ◽  
Vol 4 (10) ◽  
pp. eaat7259 ◽  
Author(s):  
Nan Yan ◽  
Nan Xia ◽  
Lingwen Liao ◽  
Min Zhu ◽  
Fengming Jin ◽  
...  
Keyword(s):  
Metal Nanoparticles ◽  
Weak Interactions ◽  
Gold Nanoclusters ◽  
Atomic Level ◽  
High Quality ◽  
X Ray ◽  
X Ray Crystallography ◽  
Quantum Size ◽  
First Time

The transition from nanocluster to nanocrystal is a central issue in nanoscience. The atomic structure determination of metal nanoparticles in the transition size range is challenging and particularly important in understanding the quantum size effect at the atomic level. On the basis of the rationale that the intra- and interparticle weak interactions play critical roles in growing high-quality single crystals of metal nanoparticles, we have reproducibly obtained ideal crystals of Au144(SR)60 and successfully solved its structure by x-ray crystallography (XRC); this structure was theoretically predicted a decade ago and has long been pursued experimentally but without success until now. Here, XRC reveals an interesting Au12 hollow icosahedron in thiolated gold nanoclusters for the first time. The Au–Au bond length, close to that of bulk gold, shows better thermal extensibility than the other Au–Au bond lengths in Au144(SR)60, providing an atomic-level perspective because metal generally shows better thermal extensibility than nonmetal materials. Thus, our work not only reveals the mysterious, long experimentally pursued structure of a transition-sized nanoparticle but also has important implications for the growth of high-quality, single-crystal nanoparticles, as well as for the understanding of the thermal extensibility of metals from the perspective of chemical bonding.

scholarly journals Developing Digital Botanical Resources for Pakistan

2019 ◽  
Vol 3 ◽  
Author(s):  
Mary Barkworth ◽  
Mushtaq Ahmad ◽  
Mudassir Asrar ◽  
Raza Bhatti ◽  
Neil Cobb ◽  
...  
Keyword(s):  
Community Of Practice ◽  
Data Use ◽  
Easy Access ◽  
Biodiversity Informatics ◽  
Biodiversity Data ◽  
High Quality ◽  
Research Activities ◽  
The World ◽  
Biodiversity Education ◽  
Using Data

In 2017, funding from the Biodiversity Information Fund for Asia accelerated data mobilization and georeferencing by Pakistani herbaria. The funding directly benefited only two herbaria but, by the end of the project 9 herbaria were involved in sharing data, 2 through GBIF (ISL 2019, SINDH 2019; codes according to Index herbariorum) and 6 others (BANNU 2019, BGH 2019, PUP 2019, QUETTA 2019, RAW 2019, SWAT 2019) through OpenHerbarium, a Symbiota based network. Eventually, all collections in OpenHerbarium are expected to become GBIF data providers. Additional Pakistani herbaria are being introduced to data mobilization and several individuals have expressed interest in learning to use OpenHerbarium to generated documented checklists for teaching and research and others for learning to link information in OpenHerbarium to other resources. These are the first steps to developing a “a large group of individuals … to train, mentor, and champion [biodiversity] data use” in Pakistan, but it is important to remember that good bioidiversity data starts in the field. We need to provide today’s collectors and educators with easy access to a) information about what constitutes a high-quality herbarium specimen; b) tools for making it easier to record and provide high quality specimen data; c) simple mechanisms for sharing data in ways that provide immediately useful resources; and d) learning to make use of the data becoming available. OpenHerbarium addresses the third and fourth needs and also makes it simple for collections to become GBIF data providers. This year, the focus will be on first two of the three steps identified. Introduction of the new resources will be used to introduce collectors and educators to the ideas underlying provision of biodiversity data that is fit for use and reuse. When Symbiota2 is functional, OpenHerbarium will be moved to that system. This will encourage development of additional tools for using biodiversity data. All these activities are essential to helping spread understanding of the concepts integral to biodiversity informatics. It is, of course, possible “to train, build, and champion data use” using data for other parts of the world, or provided by institutions from other parts of the world, but embedding good biodiversity data practices into the fabric of a country’s biodiversity education and research activities better benefits the country if a substantial portion of the data is generated from within the country. It also helps to spread knowledge of the country’s biodiversity among its students. Consequently, our focus in developing Pakistan’s capacity in biodiversity informatics is on engaging collections and collectors in sharing biodiversity data, then helping them discover, use, and create methods for developing the insights needed to encourage wise use of the country’s biological resources, and encouraging interaction. This will lead to a “community of practice” within Pakistan that can both benefit from and contribute to an international “community of practice”.

scholarly journals REPRODUCING QUALITIES OF RAMS OF THE MOLDOVAN TYPE KARAKUL BREED

2020 ◽  
Vol 59 ◽  
pp. 92-96
Author(s):  
D. Rotari
Keyword(s):  
Sperm Count ◽  
Sperm Concentration ◽  
Animal Husbandry ◽  
Sperm Production ◽  
Livestock Farming ◽  
High Quality ◽  
Average Percentage ◽  
Reproductive Ability ◽  
First Time

Issues related to the reproduction of animals have been and remain one of the most complex and relevant problems of biology and are constantly finding a direct and effective way out into livestock farming practice. The rational use of breeding sheep as producers is limited by the lack of standard, objective methods and methods for the timely assessment of their reproductive ability. The article presents the results of evaluating the sperm production of rams-producers. For the first time, the freshly obtained sperm of rams of Moldavian type producers of the Karakul breed was evaluated using the macroscopic method - ejaculate volume, color and smell, as well as the microscopic method - motility, sperm concentration in the ejaculate, total sperm count in the ejaculate sperm movements (VAP; VSL and VCL) as well as the percentage of abnormal forms of sperm. The experiments were carried out on sheep producers grown on a pedigree farm of the experimental farm of the Moldavian Scientific and Practical Institute of Biotechnology in Animal Husbandry and Veterinary Medicine. As a result of the studies, it was found that the ejaculate volume on average was 0.99 ± 0.04 ml, motility was 0.95 ± 0.02 and sperm concentration 1.51 ± 0.14 billion/ml. The percentage of pathological forms in sperm averaged 13.72 ± 0.61, an indicator that characterizes the high quality of sperm. The average quality indicator of ejaculates obtained from ram-producers of the Moldavian type of the Karakul breed corresponds to physiological standards for the Karakul breed. The average percentage of pathological forms of sperm found in ejaculates indicates that the rams were in good conditions of feeding and keeping. According to research, we can say that the Moldovan type of Karakul rams can be successfully used to obtain high quality ejaculates suitable for freezing sperm at 196°C.

Establishment of evaluation criteria for the development of high quality ERα-targeted fluorescent probes

The Analyst ◽  
2020 ◽  
Vol 145 (18) ◽  
pp. 5989-5995
Author(s):  
Qiuyu Meng ◽  
Xiaoyu Ma ◽  
Baohua Xie ◽  
Xiaofei Deng ◽  
Jian Huang ◽  
...  
Keyword(s):  
Fluorescent Probes ◽  
Evaluation Criteria ◽  
High Quality ◽  
First Time ◽  
Mcf 7

ERα targeting fluorescent probes are important tools for ERα study. Two ERα targeting fluorescent probes were developed, which exhibited better performance in MCF-7 cells. Moreover, the probes were used for the first time to study the ERα motion.

scholarly journals Assessing 5 years of GOSAT Proxy XCH<sub>4</sub> data and associated uncertainties

2015 ◽  
Vol 8 (11) ◽  
pp. 4785-4801 ◽  
Author(s):  
R. J. Parker ◽  
H. Boesch ◽  
K. Byckling ◽  
A. J. Webb ◽  
P. I. Palmer ◽  
...  
Keyword(s):  
Posteriori Error ◽  
Maximum Deviation ◽  
A Posteriori ◽  
High Quality ◽  
Validation Data ◽  
A Posteriori Error ◽  
Surface Measurements ◽  
The Individual ◽  
First Time ◽  
Surface Observations

Abstract. We present 5 years of GOSAT XCH4 retrieved using the "proxy" approach. The Proxy XCH4 data are validated against ground-based TCCON observations and are found to be of high quality with a small bias of 4.8 ppb (∼ 0.27 %) and a single-sounding precision of 13.4 ppb (∼ 0.74 %). The station-to-station bias (ameasure of the relative accuracy) is found to be 4.2 ppb. For the first time the XCH4 / XCO2 ratio component of the Proxy retrieval is validated (bias of 0.014 ppb ppm−1 (∼ 0.30 %), single-sounding precision of 0.033 ppb ppm−1 (∼ 0.72 %)). The uncertainty relating to the model XCO2 component of the Proxy XCH4 is assessed through the use of an ensemble of XCO2 models. While each individual XCO2 model is found to agree well with the TCCON validation data (r = 0.94–0.97), it is not possible to select one model as the best from our comparisons. The median XCO2 value of the ensemble has a smaller scatter against TCCON (a standard deviation of 0.92 ppm) than any of the individual models whilst maintaining a small bias (0.15 ppm). This model median XCO2 is used to calculate the Proxy XCH4 with the maximum deviation of the ensemble from the median used as an estimate of the uncertainty. We compare this uncertainty to the a posteriori retrieval error (which is assumed to reduce with sqrt(N)) and find typically that the model XCO2 uncertainty becomes significant during summer months when the a posteriori error is at its lowest due to the increase in signal related to increased summertime reflected sunlight. We assess the significance of these model and retrieval uncertainties on flux inversion by comparing the GOSAT XCH4 against modelled XCH4 from TM5-4DVAR constrained by NOAA surface observations (MACC reanalysis scenario S1-NOAA). We find that for the majority of regions the differences are much larger than the estimated uncertainties. Our findings show that useful information will be provided to the inversions for the majority of regions in addition to that already provided by the assimilated surface measurements.

Elementary classroom libraries and social studies trade books

2019 ◽  
Vol 14 (1) ◽  
pp. 14-27
Author(s):  
Tracey S. Hodges ◽  
Katherine Landau Wright ◽  
Julianne M. Coleman ◽  
Holly Hilboldt Swain ◽  
Claire Schweiker ◽  
...  
Keyword(s):  
Social Studies ◽  
Elementary Classroom ◽  
Easy Access ◽  
National Council ◽  
Trade Books ◽  
High Quality ◽  
Content Type ◽  
The Social ◽  
Classroom Libraries ◽  
K 12

Purpose Standards and policy changes in K-12 education have created the unintended consequence of reducing instructional time spent on social studies content. This limited time devoted to social studies presumably has led to more integrated social studies and literacy instruction. The purpose of this paper is to document the types of high-quality social studies children’s books found in classroom libraries across five states. Design/methodology/approach In the present mixed methods study, the researchers utilized a database of 60 classroom libraries across five states to identify which high-quality trade books, defined by the National Council for the Social Studies, were present. The researchers document trends in both frequencies of books and social studies content across decades, classrooms, grade levels and states from 1972 to 2015. Findings The findings indicate that National Council for the Social Studies (NCSS) Notable Trade Books for Young People texts are largely missing from the elementary classroom libraries the researchers sampled. Of the 5,544 unique titles included on the NCSS lists from 1972 to 2015, 453 were located in the US classroom libraries database, representing 8.17 percent of books found on the notable lists. Originality/value Before teachers can take steps toward integrating social studies and literacy, they need easy access to high-quality social studies texts. Many high-quality trade books are recommended each year for exposing students to social studies content; however, the researchers found limited numbers of these books in classroom libraries. The researchers recommend the lists be circulated to a wider audience to inform more teachers about these texts.

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