scholarly journals Влияние наличия достаточно высокой концентрации фосфора на концентрационное распределение галлия в кремнии

2022 ◽  
Vol 56 (2) ◽  
pp. 199
Author(s):  
М.К. Бахадирханов ◽  
Н.Ф. Зикриллаев ◽  
С.Б. Исамов ◽  
Х.С. Турекеев ◽  
С.А. Валиев
Keyword(s):  
High Concentration ◽  
Silicon Lattice ◽  
Unit Cells ◽  
New Material ◽  
Significant Change ◽  
Electrophysical Parameters

It was found that the silicon preliminarily doped with a high concentration of phosphorus during the diffusion of gallium, there is a significant increase in the solubility of the gallium. The results obtained are explained by the interaction of gallium and phosphorus atoms, as a result of which quasi-neutral molecules [P+Ga-] are formed. It is assumed that the formation of such quasineutral molecules [P+Ga–] stimulates the formation of Si2GaP binary unit cells in the silicon lattice. It is shown that a sufficiently high concentration of such unit cells can lead to a significant change in the electrophysical parameters of silicon, i.e. the possibility of obtaining a new material based on silicon.

A new haplolepid fauna (Osteichthyes: Actinopterygii) from the Lower Coal Measures of Scotland: Westphalian A; Langsettian, Carbonicola communis chronozone (Bashkirian)

2014 ◽  
Vol 105 (3) ◽  
pp. 207-225 ◽  
Author(s):  
Francis M. Elliott
Keyword(s):  
New Genus ◽  
Strong Indication ◽  
High Concentration ◽  
Comprehensive Description ◽  
The Family ◽  
Generic Position ◽  
New Material ◽  
Coal Measures ◽  
Dermal Bones ◽  
Brackish Environment

ABSTRACTSeven new species and one new genus of the family Haplolepidae (Actinopterygii: Palaeonisciformes) are described from new material obtained from the Drumgray coal shales, North Lanarkshire: Westphalian A (Bashkirian): Protohaplolepis isabellae; Protohaplolepis limnades; Protohaplolepis traquairi; Parahaplolepis alexandrae; Parahaplolepis elenae; Pyritocephalus youngii and Millerolepis eleionomae. The discovery of these new taxa increases the number of haplolepid species found in Europe to 16, thus producing a faunal count more than comparable to that of North America. This high concentration of haplolepid remains in limnic deposits is also a strong indication that these fish were not only adapted to a coastal paralic basin, but also well-adapted to a freshwater brackish environment. A comprehensive description of the skull roof morphology, including a short description of some of the larger dermal bones, is given of seven new haplolepid species obtained from the coal shale tips at Wester Bracco and Shotts in North Lanarkshire. In consequence, a revised table of the stratigraphical distribution of the Haplolepidae in Europe is provided. Furthermore, the new genus Millerolepis is assigned to the subfamily Parahaplolepinae and the generic position of the problematic Haplolepis attheyi from Newsham, Northumberland is discussed, with the taxonomic position of Protohaplolepis proposed.

scholarly journals Synthesis of cellulose from Acetobacter xylinum bacteria – application of making biocomposite based on polyvinyl alcohol/cellulose

2015 ◽  
Vol 18 (3) ◽  
pp. 114-124
Author(s):  
Hong Thi Thu Phan ◽  
Ngan Thi My Luong ◽  
Trung Tien Vu ◽  
Ho Thanh Pham ◽  
Huy Thuc Ha ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Polyvinyl Alcohol ◽  
Mechanical Strength ◽  
Bacterial Cellulose ◽  
High Concentration ◽  
Thermogravimetric Analyzer ◽  
Plastic Materials ◽  
New Material ◽  
Biological Films

Bacterial cellulose (BC) is characterized for its high purity, good mechanical strength, non-toxic and non-allergic. Therefore, BC was used in many applications, such as biological films, paper, textiles, electronics, and especially in the biomedical field. The aim of this study is to make a new material which has high thermal stability and mechanical strength by combining BC and two kinds of polyvinyl alcohol (PVA 127 and PVA Kuraray). In the current study, it was found that the structure of bacterial cellulose was changed when PVA at different concentrations was supplied in the bacterial culture. The dispersity of BC fibers and the density of PVA particles of the material increased with high concentration of PVA. As a masterbatch (a composite additive material), a preparation of BC/PVA 217 was mixed with PVA Kuraray, and the mixture was then placed into a mixing chamber of an electrically heated machine (Hakke, Germany) at 170C, 80 rpm for 15 min. The melting mixture was shaped by a Hydraulic shaping machine. The structure of the material was assessed by scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR). The thermal stability of the material was measured using a thermogravimetric analyzer, and its mechanical properties were also studied. The results showed that the compatibility of BC and PVA in PVA/BC material is relatively high due to intermolecular hydrogen bondings. The material showed better thermal stability than PVA only. Its mechanical properties were also improved. The finding suggests that the composites of bacterial cellulose and PVA could be good candidates for replacing traditional nonbiodegradable plastic materials.

scholarly journals KAJIAN CYCLIC VOLTAMMETRY PENGARUH SURFAKTAN GLUCOPONE 215 CSUP DALAM ELEKTROLIT SULFAT

2017 ◽  
Vol 1 (1) ◽  
pp. 33
Author(s):  
Setia Budi ◽  
Agung Purwanto ◽  
A.R. Daud
Keyword(s):  
Cyclic Voltammetry ◽  
Critical Micelle Concentration ◽  
Electrochemical Deposition ◽  
Negative Potential ◽  
Cyclic Voltammogram ◽  
Electrochemical Studies ◽  
High Concentration ◽  
Sulphate Electrolyte ◽  
Preliminary Study ◽  
Significant Change

The preliminary study on the use of Glucopone 215 CSUP surfactant as an additive in nanoparticles preparation by means of electrochemical deposition has been investigated. Critical micelle concentration (CMC) of Glucopone 215 CSUP was firstly determined both in de-ionized water and sulphate electrolyte using ensiometer. It was found that the presence of ions of the sulphate electrolyte did not make significant change on the CMC value. Electrochemical studies were then carried out using cyclic voltammetry technique. The influence of the addition of Glucopone 215 CSUP was found beyond its CMC, namely at concentration of 1.3 wt.%. In the presence of high concentration of the surfactant, The increase of current at cathodic scan of the cyclic voltammogram was observed at more negative potential  than  that  of  without  surfactant.  This  result  should  be  very  important  in  providing  suitable  co-electrodeposition potential for nanoparticles of Co, Ni and Cu electrodeposition assisted by glucopone 215 CSUP. Keywords: cyclic voltammetry, critical micelle concentration, Glucopone 215 CSUP, electrodepositionAbstrak Surfaktan  dapat  digunakan  sebagai  aditif  yang  dapat  mengontrol  dan  memodifikasi  proses  pertumbuhan  partikel yang  dipreparasi  dengan  metode  deposisi  elektrokimia.  Kajian  pendahuluan  terhadap  pengaruh  penggunaan surfaktan Glucopone 215 CSUP terhadap karakteristik elektrokimia elektrolit sulfat telah dilakukan menggunakan teknik cyclic voltammetry. Hasil pengukuran menggunakan tensiometer menunjukkan bahwa ion-ion dari elektrolit tidak  menimbulkan  perbedaan  signifikan  terhadap  critical  micelle  concentration  (CMC)  surfaktan  yang  dikaji. Pengaruh penambahan surfaktan Glucopone 215 CSUP terhadap cyclic voltammogram teramati ketika konsentrasi surfaktan  diatas  nilai  CMC-nya.  Katodik  scan  dari  cyclic  voltammogram  menunjukkan  bahwa  pada  konsentrasi diatas  surfaktan,  1,3  wt.%,  titik  kenaikan  arus  katodik  bergeser  ke  potensial  yang  semakin  negatif.  Hasil  ini memberikan informasi potensial co-electrodeposisi yang sesuai untuk Co, Ni, dan Cu yang dipreparasi dari elektrolit sulfat dengan menggunakan aditif Glucopone 215 CSUP.Keywords: cyclic voltammetry, critical micelle concentration, Glucopone 215 CSUP, elektrodeposisi

scholarly journals Na@La-modified zeolite particles for simultaneous removal of ammonia nitrogen and phosphate from rejected water: performance and mechanism

2020 ◽  
Vol 82 (12) ◽  
pp. 2975-2989
Author(s):  
Wenjiao Sang ◽  
Longjie Mei ◽  
Shiwen Hao ◽  
Dong Li ◽  
Xiaoyang Li ◽  
...  
Keyword(s):  
Wastewater Treatment Plants ◽  
Low Cost ◽  
Treatment Method ◽  
Ammonia Nitrogen ◽  
Maximum Adsorption Capacity ◽  
High Concentration ◽  
Nitrogen And Phosphorus ◽  
Initial Ph ◽  
New Material ◽  
Convenient Technique

Abstract Rejected water from sludge processing in wastewater treatment plants (WWTPs) is very harmful due to its high concentration of ammonia nitrogen and phosphorus. It is therefore necessary to find a low-cost and convenient technique to simultaneously remove ammonia nitrogen and phosphorus from rejected water. In this study, natural granular zeolite was modified by NaCl and La(OH)3 to obtain a new material (Na@La-MZP), with several advantages compared with powdered zeolite. Na@La-MZP could remove 92.61% ammonia nitrogen (50 mg/L) and 99.01% phosphate (60 mg/L) at the optimal conditions of dosage 12.5 g/L, initial pH 6.0 and reaction time 12 hours, which enabled the effluent to satisfy the discharge standard (GB 18918-2002) for municipal WWTPs in China. The maximum adsorption capacity of Na@La-MZP was determined as 17.92 mg -N/g and 9.53 mg P/g by the Langmuir isotherm. Pseudo-second-order kinetics could well illustrate the adsorption process and show that the ammonia nitrogen and phosphate can be degraded by chemical reaction. The characterizations of Na@La-MZP confirmed the removal mechanism of ammonia nitrogen and phosphate. The Na@La-MZP still maintained more than 75% removal efficiency after five reuses. Furthermore, the estimated cost of this treatment method was 0.22 $/m3 rejected water.

scholarly journals Development of Co(OH)xF2−x Nanosheets for Acetone Gas Sensor Applications: Material Characterization and Sensor Performance Evaluation

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 968
Author(s):  
Yaping Yan ◽  
Tae-yil Eom ◽  
Shiyu Xu ◽  
Pil J. Yoo ◽  
Changzeng Yan ◽  
...  
Keyword(s):  
Gas Sensor ◽  
Material Characterization ◽  
High Specific Surface Area ◽  
High Concentration ◽  
Hydrothermal Route ◽  
Sensor Applications ◽  
Sensor Performance ◽  
Operation Temperature ◽  
Catalytic Function ◽  
New Material

This study reports the employment of Co(OH)xF2−x nanosheets, a new material in the sensor field, for gas sensor applications. We synthesize Co(OH)xF2−x nanosheets via a hydrothermal route using SiO2 sphere templates. Our material characterization confirms that the material is a densely clustered Co(OH)xF2−x nanosheet with an amorphous microstructure with some short-range ordering. Sensors based on the nanosheets demonstrate a high response of 269% toward 4.5 ppm of acetone gas at an operation temperature of 200 °C and a very low minimum detection limit of 40 ppb. It functions effectively up to a temperature below 300 °C, above which F is found to start to evaporate. Our discussion suggests that an excellent sensor performance arises from the high catalytic function of F incorporated in a high concentration in the material as well as the high specific surface area due to the morphology of densely clustered nanosheets.

Measurement and Reduction of Radiation Damage in Frozen Hydrated Crystalline Specimens

1978 ◽  
Vol 36 (3) ◽  
pp. 70-77 ◽  
Author(s):  
R.M. Glaeser ◽  
S.B. Hayward
Keyword(s):  
Diffraction Pattern ◽  
Structural Information ◽  
Structural Disorder ◽  
Structural Features ◽  
Biological Macromolecules ◽  
Diffraction Intensity ◽  
Object Structure ◽  
Specimen Material ◽  
Unit Cells ◽  
Identical Unit

Highly ordered or crystalline biological macromolecules become severely damaged and structurally disordered after a brief electron exposure. Evidence that damage and structural disorder are occurring is clearly given by the fading and eventual disappearance of the specimen's electron diffraction pattern. The fading and disappearance of sharp diffraction spots implies a corresponding disappearance of periodic structural features in the specimen. By the same token, there is a oneto- one correspondence between the disappearance of the crystalline diffraction pattern and the disappearance of reproducible structural information that can be observed in the images of identical unit cells of the object structure. The electron exposures that result in a significant decrease in the diffraction intensity will depend somewhat upon the resolution (Bragg spacing) involved, and can vary considerably with the chemical makeup and composition of the specimen material.

Cytomembrane Preservation in Tissue Dehydrated Only With Glutaraldehyde and Epon 812 Resin

1973 ◽  
Vol 31 ◽  
pp. 320-321
Author(s):  
Daniel C. Pease
Keyword(s):  
Diffraction Pattern ◽  
X Ray Diffraction ◽  
High Concentration ◽  
Unpublished Study ◽  
X Ray ◽  
Sectioned Material

A previous study demonstrated that tissue could be successfully infiltrated with 50% glutaraldehyde, and then subsequently polymerized with urea to create an embedment which retained cytomembrane lipids in sectioned material. As a result, the 180-190 Å periodicity characteristic of fresh, mammalian myelin was preserved in sections, as was a brilliant birefringence, and the capacity to bind OsO4 vapor in the hydrophobic bilayers. An associated (unpublished) study, carried out in co-operation with Drs. C.K. Akers and D.F. Parsons, demonstrated that the high concentration of glutaraldehyde (and urea) did not significantly alter the X-ray diffraction pattern of aldehyde-fixed, myelin. Thus, by itself, 50% glutaraldehyde has little effect upon cytomembrane systems and can be used with confidence for the first stages of dehydration.

Effects of carbamylcholine on chick embryo aggregate retina cell cultures

1988 ◽  
Vol 46 ◽  
pp. 350-351
Author(s):  
Glenn M. Cohen ◽  
Radharaman Ray
Keyword(s):  
Cell Cultures ◽  
Single Cells ◽  
Retinal Cell ◽  
Cell Aggregates ◽  
High Concentration ◽  
In Ovo ◽  
Sterile Culture ◽  
Retinal Tissue ◽  
Synaptic Junctions ◽  
And Control

Retinal,cell aggregates develop in culture in a pattern similar to the in ovo retina, forming neurites first and then synapses. In the present study, we continuously exposed chick retinal cell aggregates to a high concentration (1 mM) of carbamylcholine (carbachol), an acetylcholine (ACh) analog that resists hydrolysis by acetylcholinesterase (AChE). This situation is similar to organophosphorus anticholinesterase poisoning in which the ACh level is elevated at synaptic junctions due to inhibition of AChE, Our objective was to determine whether continuous carbachol exposure either damaged cholino- ceptive neurites, cell bodies, and synaptic elements of the aggregates or influenced (hastened or retarded) their development.The retinal tissue was isolated aseptically from 11 day embryonic White Leghorn chicks and then enzymatically (trypsin) and mechanically (trituration) dissociated into single cells. After washing the cells by repeated suspension and low (about 200 x G) centrifugation twice, aggregate cell cultures (about l0 cells/culture) were initiated in 1.5 ml medium (BME, GIBCO) in 35 mm sterile culture dishes and maintained as experimental (containing 10-3 M carbachol) and control specimens.

Sign in / Sign up

Export Citation Format

Share Document