scholarly journals Synthesis of fluorinated phosphonic, sulfonic, and mixed phosphonic/sulfonic acids

1989 ◽  
Vol 67 (11) ◽  
pp. 1795-1799 ◽  
Author(s):  
Debao Su ◽  
Wenbiao Cen ◽  
Robert L. Kirchmeier ◽  
Jean'ne M. Shreeve
Keyword(s):  
Aqueous Solution ◽  
Elevated Temperature ◽  
Mass Spectroscopy ◽  
Sulfonic Acids ◽  
Phosphonic Acids ◽  
Degree Of Stability ◽  
High Degree ◽  
Strong Acids ◽  
Acid Precursor

The acids (HO)2P(O)CFHSO3H, (HO)2P(O)(CF2)4O(CF2)2SO3H, H(CF2)2O(CF2)2P(O)(OH)2, H(CF2)2O(CF2)4P(O)(OH)2, (HO)2P(O)(CF2)2O(CF2)4H, and the acid precursor (C2H5O)2P(O)CF(SO3Na)2 have been synthesized. Elemental analysis, 19F, 1H, and 31P NMR, and mass spectroscopy were used for characterization of these materials. They are very strong acids, and exhibit a high degree of stability in aqueous solution at elevated temperature, which makes them attractive candidates for use as electrolytes in fuel cells. Keywords: fluorinated phosphonic acids; fluorinated sulfonic acids; 1H, 19F, 31P NMR.

scholarly journals SYNTHESIS AND CHARACTERIZATION OF FEED GRADE MONOCALCIUM PHOSPHATE, Ca(H2PO4)2·H2O IN AQUEOUS MEDIUM

2018 ◽  
Vol 54 (4A) ◽  
pp. 7
Author(s):  
Nguyen Quang Bac
Keyword(s):  
Thermal Analysis ◽  
Aqueous Solution ◽  
Infrared Spectroscopy ◽  
Elevated Temperature ◽  
Calcium Content ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Monocalcium Phosphate ◽  
X Ray

The feed grade monocalcium phosphate monohydrate, Ca(H2PO4)2·H2O was prepared by the reaction of CaCO3 and H3PO4 at elevated temperature in aqueous solution. The obtained precipitates were characterized by powder X-ray diffraction, infrared spectroscopy (FTIR), and thermal analysis (TG, DTA) techniques. The chemical composition of final products was evaluated by analysing the phosphorus and calcium content in the samples.

Characterization of RF Sputtered ZnO Piezoelectric Films Using Transmission Electron Microscope

1975 ◽  
Vol 33 ◽  
pp. 86-87
Author(s):  
Kemining W. Yeh ◽  
Richard S. Muller ◽  
Wei-Kuo Wu ◽  
Jack Washburn
Keyword(s):  
Integrated Circuit ◽  
Acoustic Waves ◽  
New Technology ◽  
Surface Acoustic Waves ◽  
Electromechanical Properties ◽  
Leading Role ◽  
Saw Devices ◽  
Transmission Electron ◽  
High Degree

Considerable and continuing interest has been shown in the thin film transducer fabrication for surface acoustic waves (SAW) in the past few years. Due to the high degree of miniaturization, compatibility with silicon integrated circuit technology, simplicity and ease of design, this new technology has played an important role in the design of new devices for communications and signal processing. Among the commonly used piezoelectric thin films, ZnO generally yields superior electromechanical properties and is expected to play a leading role in the development of SAW devices.

Introduction

2017 ◽  
Author(s):  
Detlef Pollack ◽  
Gergely Rosta
Keyword(s):  
The Netherlands ◽  
Western Europe ◽  
West Germany ◽  
World Today ◽  
The World ◽  
Degree Of Stability ◽  
Important Exception ◽  
High Degree ◽  
Religious Landscape

In recantation of his earlier approach, Peter L. Berger now claims: ‘The world today, with some exceptions […], is as furiously religious as it ever was, and in some places more so than ever.’ The most important exception that Berger refers to is Western Europe. The introduction to Part II provides an overview of the religious landscape in Western Europe. The data show that the current religious situation in the countries of Western Europe is in fact subject to considerable variation. It would therefore be erroneous to describe Western Europe as secularized. At the same time, the data reveal that there have been clear secularization tendencies over the last few decades. To grasp the diversity of religious tendencies, Part II deals with three cases: West Germany with moderate downward tendencies, Italy with a considerably high degree of stability, and the Netherlands displaying disproportionately strong secularizing tendencies.

scholarly journals New Insights on the Zeugodacus cucurbitae (Coquillett) Bacteriome

2021 ◽  
Vol 9 (3) ◽  
pp. 659
Author(s):  
Elias Asimakis ◽  
Panagiota Stathopoulou ◽  
Apostolis Sapounas ◽  
Kanjana Khaeso ◽  
Costas Batargias ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Bacterial Communities ◽  
High Throughput Sequencing ◽  
Mutual Exclusion ◽  
Bacterial Composition ◽  
Operational Taxonomic Units ◽  
Host Diet ◽  
Dominant Bacteria ◽  
High Degree

Various factors, including the insect host, diet, and surrounding ecosystem can shape the structure of the bacterial communities of insects. We have employed next generation, high-throughput sequencing of the 16S rRNA to characterize the bacteriome of wild Zeugodacus (Bactrocera) cucurbitae (Coquillett) flies from three regions of Bangladesh. The tested populations developed distinct bacterial communities with differences in bacterial composition, suggesting that geography has an impact on the fly bacteriome. The dominant bacteria belonged to the families Enterobacteriaceae, Dysgomonadaceae and Orbaceae, with the genera Dysgonomonas, Orbus and Citrobacter showing the highest relative abundance across populations. Network analysis indicated variable interactions between operational taxonomic units (OTUs), with cases of mutual exclusion and copresence. Certain bacterial genera with high relative abundance were also characterized by a high degree of interactions. Interestingly, genera with a low relative abundance like Shimwellia, Gilliamella, and Chishuiella were among those that showed abundant interactions, suggesting that they are also important components of the bacterial community. Such knowledge could help us identify ideal wild populations for domestication in the context of the sterile insect technique or similar biotechnological methods. Further characterization of this bacterial diversity with transcriptomic and metabolic approaches, could also reveal their specific role in Z. cucurbitae physiology.

scholarly journals Genomic Tackling of Human Satellite DNA: Breaking Barriers through Time

2021 ◽  
Vol 22 (9) ◽  
pp. 4707
Author(s):  
Mariana Lopes ◽  
Sandra Louzada ◽  
Margarida Gama-Carvalho ◽  
Raquel Chaves
Keyword(s):  
Human Genome ◽  
Satellite Dna ◽  
Repetitive Sequences ◽  
Nucleotide Composition ◽  
Genomic Component ◽  
Genomic Studies ◽  
Human Genomic ◽  
Definition Of ◽  
High Degree

(Peri)centromeric repetitive sequences and, more specifically, satellite DNA (satDNA) sequences, constitute a major human genomic component. SatDNA sequences can vary on a large number of features, including nucleotide composition, complexity, and abundance. Several satDNA families have been identified and characterized in the human genome through time, albeit at different speeds. Human satDNA families present a high degree of sub-variability, leading to the definition of various subfamilies with different organization and clustered localization. Evolution of satDNA analysis has enabled the progressive characterization of satDNA features. Despite recent advances in the sequencing of centromeric arrays, comprehensive genomic studies to assess their variability are still required to provide accurate and proportional representation of satDNA (peri)centromeric/acrocentric short arm sequences. Approaches combining multiple techniques have been successfully applied and seem to be the path to follow for generating integrated knowledge in the promising field of human satDNA biology.

scholarly journals Stoichiometry and compositional plasticity of the yeast nuclear pore complex revealed by quantitative fluorescence microscopy

2018 ◽  
Vol 115 (17) ◽  
pp. E3969-E3977 ◽  
Author(s):  
Sasikumar Rajoo ◽  
Pascal Vallotton ◽  
Evgeny Onischenko ◽  
Karsten Weis
Keyword(s):  
Nuclear Pore Complex ◽  
Yeast Cells ◽  
Nuclear Pore ◽  
Altered Expression ◽  
Copy Numbers ◽  
Quantitative Image ◽  
Multiple Copies ◽  
Almost All ◽  
High Degree

The nuclear pore complex (NPC) is an eightfold symmetrical channel providing selective transport of biomolecules across the nuclear envelope. Each NPC consists of ∼30 different nuclear pore proteins (Nups) all present in multiple copies per NPC. Significant progress has recently been made in the characterization of the vertebrate NPC structure. However, because of the estimated size differences between the vertebrate and yeast NPC, it has been unclear whether the NPC architecture is conserved between species. Here, we have developed a quantitative image analysis pipeline, termed nuclear rim intensity measurement (NuRIM), to precisely determine copy numbers for almost all Nups within native NPCs of budding yeast cells. Our analysis demonstrates that the majority of yeast Nups are present at most in 16 copies per NPC. This reveals a dramatic difference to the stoichiometry determined for the human NPC, suggesting that despite a high degree of individual Nup conservation, the yeast and human NPC architecture is significantly different. Furthermore, using NuRIM, we examined the effects of mutations on NPC stoichiometry. We demonstrate for two paralog pairs of key scaffold Nups, Nup170/Nup157 and Nup192/Nup188, that their altered expression leads to significant changes in the NPC stoichiometry inducing either voids in the NPC structure or substitution of one paralog by the other. Thus, our results not only provide accurate stoichiometry information for the intact yeast NPC but also reveal an intriguing compositional plasticity of the NPC architecture, which may explain how differences in NPC composition could arise in the course of evolution.

Optical Absorption Spectroscopy of DNA-Wrapped HiPco Carbon Nanotubes

2019 ◽  
Vol 943 ◽  
pp. 95-99
Author(s):  
Li Jun Wang ◽  
Kazuo Umemura
Keyword(s):  
Carbon Nanotubes ◽  
Aqueous Solution ◽  
Optical Absorption ◽  
Absorption Spectroscopy ◽  
Near Infrared ◽  
Nir Spectroscopy ◽  
Optical Characterization ◽  
Optical Absorption Spectroscopy ◽  
Double Stranded Dna

Optical absorption spectroscopy provides evidence for individually dispersed carbon nanotubes. A common method to disperse SWCNTs into aqueous solution is to sonicate the mixture in the presence of a double-stranded DNA (dsDNA). In this paper, optical characterization of dsDNA-wrapped HiPco carbon nanotubes (dsDNA-SWCNT) was carried out using near infrared (NIR) spectroscopy and photoluminescence (PL) experiments. The findings suggest that SWCNT dispersion is very good in the environment of DNA existing. Additionally, its dispersion depends on dsDNA concentration.

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