scholarly journals Chemical characteristics of organic-based liquid inoculant of Bacillus spp

2019 ◽  
Vol 393 ◽  
pp. 012005
Author(s):  
R Hindersah ◽  
M R Setiawati ◽  
B N Fitriatin ◽  
P Suryatmana ◽  
P Asmiran
Keyword(s):  
Chemical Characteristics ◽  
Bacillus Spp ◽  
Liquid Inoculant

Characterization of defects in tabular silver halide grains

1990 ◽  
Vol 48 (4) ◽  
pp. 1046-1047
Author(s):  
C. Goessens ◽  
D. Schryvers ◽  
J. Van Landuyt ◽  
A. Verbeeck ◽  
R. De Keyzer
Keyword(s):  
Radiation Damage ◽  
Silver Halide ◽  
Chemical Characteristics ◽  
X Ray ◽  
Free Region ◽  
Central Defect ◽  
Crystallographic Defects ◽  
Physical And Chemical ◽  
Two Sides

Silver halide grains (AgX, X=Cl,Br,I) are commonly recognized as important entities in photographic applications. Depending on the preparation specifications one can grow cubic, octahedral, tabular a.o. morphologies, each with its own physical and chemical characteristics. In the present study crystallographic defects introduced by the mixing of 5-20% iodide in a growing AgBr tabular grain are investigated. X-ray diffractometry reveals the existence of a homogeneous Ag(Br1-xIx) region, expected to be formed around the AgBr kernel. In fig. 1 a two-beam BF image, taken at T≈100 K to diminish radiation damage, of a triangular tabular grain is presented, clearly showing defect contrast fringes along four of the six directions; the remaining two sides show similar contrast under relevant diffraction conditions. The width of the central defect free region corresponds with the pure AgBr kernel grown before the mixing with I. The thickness of a given grain lies between 0.15 and 0.3 μm: as indicated in fig. 2 triangular (resp. hexagonal) grains exhibit an uneven (resp. even) number of twin interfaces (i.e., between + and - twin variants) parallel with the (111) surfaces. The thickness of the grains and the existence of the twin variants was confirmed from CTEM images of perpendicular cuts.

Inorganic and organic chemical characteristics and sources of suspended particulate matters in Ulaanbaatar, Mongolia

2020 ◽  
Vol 54 (4) ◽  
pp. 267-276
Author(s):  
Koshi Yamamoto ◽  
Yuta Suzuki ◽  
Gochoobazar Oyunjargal ◽  
Hiroyuki Fukuda ◽  
Munkhtsetseg Oidov ◽  
...  
Keyword(s):  
Organic Chemical ◽  
Chemical Characteristics ◽  
Particulate Matters ◽  
Suspended Particulate ◽  
Suspended Particulate Matters ◽  
Inorganic And Organic

Solution chemistry effects on the solvation shell of metal ions

2020 ◽  
Author(s):  
Xiangwen Wang ◽  
Dimitrios Toroz ◽  
Seonmyeong Kim ◽  
Simon Clegg ◽  
Gun-Sik Park ◽  
...  
Keyword(s):  
Metal Ions ◽  
Pure Water ◽  
Solvation Shell ◽  
Solution Chemistry ◽  
Chemical Characteristics ◽  
Velocity Autocorrelation Function ◽  
Ionic Solvation ◽  
General Terms ◽  
Alkaline Earth Metal Ions ◽  
Wide Range

<div> <p>As natural aqueous solutions are far from being pure water, being rich in ions, the properties of solvated ions are of relevance for a wide range of systems, including biological and geochemical environments. We conducted ab initio and classical MD simulations of the alkaline earth metal ions Mg<sup>2+</sup> and Ca<sup>2+</sup> and of the alkali metal ions Li<sup>+</sup>, Na<sup>+</sup>, K<sup>+</sup> and Cs<sup>+</sup> in pure water and electrolyte solutions containing the counterions Cl<sup>–</sup> and SO<sub>4</sub><sup>2–</sup>. Through a detailed analysis of these simulations, this study reports on the effect of solution chemistry (composition and concentration of the solution) to the ion–water structural properties and interaction strength, and to the dynamics, hydrogen bond network, and low-frequency dynamics of the ionic solvation shell. Except for the ion–water radial distribution function, which is weakly dependent on the counter-ions and concentrations, we found that all other properties can be significantly influenced by the chemical characteristics of the solution. Calculation of the velocity autocorrelation function of magnesium ions, for example, shows that chlorine ions located in the second coordination shell of Mg<sup>2+</sup> weaken the Mg(H<sub>2</sub>O)<sub>6</sub><sup>2+</sup> hydration ‘cage’ of the cation. The result reported in this study suggest that ionic solvation shell can be significantly influenced by the interactions between other ions present in solution ions, especially those of opposite charge. In more general terms, the chemical characteristics of the solution, including the balance between ion-solvent and ion-ion interactions, could result in significant differences in behavior and function of the ionic solvation shell.</p> </div>

PHÂN LẬP VÀ TUYỂN CHỌN CÁC CHỦNG BACILLUS ỨC CHẾ VI KHUẨN VIBRIO PARAHAEMOLYTICUS GÂY BỆNH TÔM CHẾT SỚM Ở TỈNH THỪA THIÊN HUẾ

2015 ◽  
Vol 100 (1) ◽  
Author(s):  
Nguyễn Thị Bích Đào ◽  
Trần Quang Khánh Vân ◽  
Nguyễn Văn Khanh ◽  
Nguyễn Quang Linh
Keyword(s):  
Bacillus Subtilis ◽  
Vibrio Parahaemolyticus ◽  
Bacillus Amyloliquefaciens ◽  
Bacillus Spp ◽  
Bacillus Subtilis B1

Khi tình hình bệnh hội chứng tôm chết sớm (EMS) đã gây thiệt hại vô cùng to lớn đối với Nuôi trồng thủy sản thì các giải pháp được đề nghị và áp dụng nhằm hạn chế dịch bệnh. Trong đó, việc tìm hiểu và đưa vi khuẩn có lợi để cạnh tranh và ức chế loài vi khuẩn gây bệnh rất được quan tâm, được cho là giải pháp có nhiều triển vọng phù hợp với điều kiện môi trường, đảm bảo sức khỏe cho con người, cũng như hạn chế được dịch bệnh. Đặc biệt, đưa vi khuẩn Bacillus spp. qua đường tiêu hóa của tôm ngay từ khi mới thả đã hạn chế được mật độ vi khuẩn Vibrio. Nghiên cứu này đã phân lập được các chủng Bacillus subtilis B1, Bacillus subtilis B2, Bacillus amyloliquefaciens B4và thử khả năng đối kháng với vi khuẩn Vibrio parahaemolyticus V1 ở các nồng độ 103, 104, 105, 106 CFU theo dõi ở các thời điểm 6h, 12h, 24h, 48h và 72h. Kết quả cho thấy cả ba chủng vi khuẩn Bacillus trên phân lập được đều có khả năng ức chế tốt vi khuẩn Vibrio parahaemolyticus V1, trong đó vi khuẩn Bacillus amyloliquefaciens B4 làtốt nhất với đường kính vòng kháng khuẩn 52,67 ± 4,31mm ở thời điểm 48h; hai chủng Bacillus subtilis B1, Bacillus subtilis B2 lầnlượt là  49,67 ± 3,15 mm, 44,07 ± 5,19 mm, với mức sai số có ý nghĩa thống kê p < 0,05.

Assessment of Bacterial Contamination of Orthodontic Arch wire

2019 ◽  
Vol 31 (1) ◽  
pp. 48-51
Author(s):  
Suha S Hassan ◽  
Nidhal H. Ghaib ◽  
Batool H Al-Ghurabi
Keyword(s):  
Bacterial Contamination ◽  
Microbial Contamination ◽  
Ethylenediaminetetraacetic Acid ◽  
Bacterial Species ◽  
Brain Heart Infusion ◽  
Control Groups ◽  
Dental Practitioners ◽  
Significant Difference ◽  
Bacillus Spp ◽  
Droplet Transmission

Background: The microorganisms can impend the life of health care professional and particularly the dental practitioners. They can be transmitted by different ways like airborne and droplet transmission. The current study was carried out to identify whether the arch wires that received from the manufactures are free from microbial contamination and to determine the bacterial species attached to the arch wires. Materials and Methods: This study involved eighty samples, consisted of two types of arch wires (nitinol and stainless-steel) from four companies (3M, G&H, Jiscop, OrthoTechnology). These wires inserted in a plane tube that contains 10 -ml of (Tris [tris(hydroxymethyl)aminomethane] and EDTA (ethylenediaminetetraacetic acid) tris-EDTA and brain heart infusion (BHI) broth. A 0.1 ml was withdrawn from the tube and spread on agar plates. The control groups consist of 16 plane tube (8 tubes with tris-EDTA and other 8 tubes with (BHI). Results: Microbial sampling yielded growth from 5 of the 80 arch wires. The predominant bacteria that isolated were Bacillus spp. No growth was recovered from 75 of the samples and from controls. The bacteria were isolated by BHI reagent and no growth was observed by tris-EDTA reagent with statistically significant difference (P<0.05). The Bacillus spp. found only in the G&H and Jiscop companies, however, no statistically significant difference was found among them (P>0.05). With regard to the presence and distribution of bacteria according to the types of wires, the present results clarified that cases of contamination with Bacillus spp. were found in the nitinol arch wires with statistically significant difference (P<0.05). Conclusions: The results of the current study revealed low count of bacterial contamination in the two types of companies (G&H and Jiscop). Not all materials that received from the manufactures are free from contamination and an effective sterilization regimen is needed to avoid cross-contamination.

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