Analysis of Surface Reaction for Group III-V Compound Semiconductors in Functional Water

2021 ◽  
Vol 314 ◽  
pp. 84-88
Author(s):  
Kenya Nishio ◽  
Takashi Oinoue ◽  
Suguru Saito ◽  
Yoshiya Hagimoto ◽  
Yuichi Ogawa ◽  
...  
Keyword(s):  
Carrier Mobility ◽  
Surface Reaction ◽  
Compound Semiconductors ◽  
Interfacial Properties ◽  
Low Ph ◽  
Group Iii ◽  
Hydrogen Water ◽  
Insulator Film ◽  
Higher Carrier Mobility ◽  
Ph Range

Group III–V compound semiconductors are attracting attention as new channel materials that have higher carrier mobility than Si. However, defects easily occur at the interface between the semiconductor and insulator film, which degrades performance. In an earlier study, we demonstrated that the interfacial properties of InP are degraded by the growth of In2O3 and that In2O3 grows better in water than in air. Therefore, it is necessary to suppress the growth of In2O3 to improve the interfacial properties of InP. In this work, we focused on functional water, which can be controlled by adjusting the water conditions, and investigated the growth behavior of In2O3 in functional water. As a result, we found that the growth is suppressed in the low-pH range and in hydrogen water. It is important that H+ ions reduce OH− ions, which contributes to the reaction with InP.

Cleaning of III-V Materials: Surface Chemistry Considerations

2012 ◽  
Vol 195 ◽  
pp. 98-99 ◽  
Author(s):  
Dennis H. van Dorp ◽  
Daniel Cuypers ◽  
Sophia Arnauts ◽  
Paul W. Mertens ◽  
Stefan de Gendt
Keyword(s):  
Charge Carrier ◽  
Surface Chemistry ◽  
Carrier Mobility ◽  
Compound Semiconductors ◽  
Charge Carrier Mobility ◽  
Group Iii ◽  
Acidic Solutions ◽  
Chemical Solutions ◽  
Wet Chemical ◽  
High Charge Carrier Mobility

Compound semiconductors based on group III and V elements of the periodic system have high charge carrier mobility and are, therefore, candidates for channel material in future CMOS devices [1]. In order to design wet chemical solutions that lead to appropriate surface pre-conditioning and allow for nanoscale processing and minimal substrate loss, a thorough understanding of the interactions between the substrate and the chemical solutions is needed and the basic etching mechanisms needs to be resolved. The focus of this research is on InP in acidic solutions. ESH aspects are also considered.

scholarly journals Backbone Effects on the Thermoelectric Properties of Ultra-Small Bandgap Conjugated Polymers

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2486
Author(s):  
Dexun Xie ◽  
Jing Xiao ◽  
Quanwei Li ◽  
Tongchao Liu ◽  
Jinjia Xu ◽  
...  
Keyword(s):  
Conjugated Polymers ◽  
Power Factor ◽  
Carrier Mobility ◽  
Polymeric Materials ◽  
Thermoelectric Performance ◽  
Organic Thermoelectric Materials ◽  
Higher Power ◽  
Donor Acceptor ◽  
Maximum Power Factor ◽  
Higher Carrier Mobility

Conjugated polymers with narrower bandgaps usually induce higher carrier mobility, which is vital for the improved thermoelectric performance of polymeric materials. Herein, two indacenodithiophene (IDT) based donor–acceptor (D-A) conjugated polymers (PIDT-BBT and PIDTT-BBT) were designed and synthesized, both of which exhibited low-bandgaps. PIDTT-BBT showed a more planar backbone and carrier mobility that was two orders of magnitude higher (2.74 × 10−2 cm2V−1s−1) than that of PIDT-BBT (4.52 × 10−4 cm2V−1s−1). Both exhibited excellent thermoelectric performance after doping with 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane, where PIDTT-BBT exhibited a larger conductivity (0.181 S cm−1) and a higher power factor (1.861 μW m−1 K−2) due to its higher carrier mobility. The maximum power factor of PIDTT-BBT reached 4.04 μW m−1 K−2 at 382 K. It is believed that conjugated polymers with a low bandgap are promising in the field of organic thermoelectric materials.

scholarly journals Common Loon, Gavia immer, Breeding Success in Relation to Lake pH and Lake Size Over 25 Years

2009 ◽  
Vol 123 (2) ◽  
pp. 146 ◽  
Author(s):  
Robert Alvo
Keyword(s):  
Breeding Success ◽  
Low Ph ◽  
Single Pair ◽  
Gavia Immer ◽  
Common Loon ◽  
Sulphur Deposition ◽  
Acidic Lakes ◽  
Ph Range ◽  
Lake Size ◽  
Critical Ph

I monitored Common Loon (Gavia immer) breeding success in relation to lake pH (range 4.0–8.5) between 1982 and 2007 on 38 single-pair lakes (5–88 ha) in the Sudbury, Ontario, area. No chicks fledged on lakes with pH < 4.4. Chicks fledged on lakes with slightly higher pH only if the lakes were relatively large. Acidic lakes became less acidic as sulphur dioxide emissions from the Sudbury smelters and sulphur deposition from other long-range sources decreased. Two lakes initially too acidic to support successful loon reproduction eventually had successful reproduction. One loon pair used two large acidic lakes (combined area 140 ha) connected by shallow rapids, and one of the adults made extremely long dives (average = 99 s) while foraging for the chicks. One chick died on that lake after apparently ingesting a very large food item; the lack of smaller items was attributed to the lake’s acidity. My results suggest that a shortage of food for chicks is the main reason why low pH reduces breeding success. I suggest that, for lakes without high levels of dissolved organic carbon (DOC), the critical pH for loon breeding success is approximately 4.3, and the suboptimal pH is approximately 4.4–6.0.

scholarly journals THE ABSORPTION SPECTRUM OF VISUAL PURPLE

1938 ◽  
Vol 21 (4) ◽  
pp. 411-430 ◽  
Author(s):  
Aurin M. Chase ◽  
Charles Haig
Keyword(s):  
Absorption Spectrum ◽  
Absorption Spectra ◽  
Light Transmission ◽  
Low Ph ◽  
The Other ◽  
Distilled Water ◽  
Color Purity ◽  
Chemical Combination ◽  
Ph Range ◽  
Sensitive Group

The absorption spectra of visual purple solutions extracted by various means were measured with a sensitive photoelectric spectrophotometer and compared with the classical visual purple absorption spectrum. Hardening the retinas in alum before extraction yielded visual purple solutions of much higher light transmission in the blue and violet, probably because of the removal of light-dispersing substances. Re-extraction indicated that visual purple is more soluble in the extractive than are the other colored retinal components. However, the concentration of the extractive did not affect the color purity of the extraction but did influence the keeping power. This suggests a chemical combination between the extractive and visual purple. The pH of the extractive affected the color purity of the resulting solution. Over the pH range from 5.5 to 10.0, the visual purple color purity was greatest at the low pH. Temperature during extraction was also effective, the color purity being greater the higher the temperature, up to 40°C. Drying and subsequent re-dissolving of visual purple solutions extracted with digitalin freed the solution of some protein impurities and increased its keeping power. Dialysis against distilled water seemed to precipitate visual purple from solution irreversibly. None of the treatments described improved the symmetry of the unbleached visual purple absorption spectrum sufficiently for it to resemble the classical absorption spectrum. Therefore it is very likely that the classical absorption spectrum is that of the light-sensitive group only and that the absorption spectra of our purest unbleached visual purple solutions represent the molecule as a whole.

2D planar penta-MN2 (M = Pd, Pt) sheets identified through structure search

2019 ◽  
Vol 21 (1) ◽  
pp. 246-251 ◽  
Author(s):  
Kexian Zhao ◽  
Xiaoyin Li ◽  
Shuo Wang ◽  
Qian Wang
Keyword(s):  
Carrier Mobility ◽  
Structure Search ◽  
Higher Carrier Mobility

Planar penta-MN2 sheets are energetically more stable than pyrite MN2, and penta-PtN2 has higher carrier mobility than phosphorene.

scholarly journals Effect of pH on the interaction of botulinum neurotoxins A, B and E with liposomes

1989 ◽  
Vol 259 (1) ◽  
pp. 47-53 ◽  
Author(s):  
C Montecucco ◽  
G Schiavo ◽  
B R Dasgupta
Keyword(s):  
Fatty Acid ◽  
Botulinum Neurotoxin ◽  
Structural Changes ◽  
Polar Region ◽  
Low Ph ◽  
Hydrophobic Core ◽  
Head Groups ◽  
Botulinum Neurotoxins ◽  
Ph Range ◽  
Lipid Interaction

The interaction of botulinum neurotoxin serotypes A, B and E with membranes of different lipid compositions was examined by photolabelling with two photoreactive phosphatidylcholine analogues that monitor the polar region and the hydrophobic core of the lipid bilayer. At neutral pH the neurotoxins interacted both with the polar head groups and with fatty acid chains of phospholipids. At acidic pHs the neurotoxins underwent structural changes characterized by a more extensive interaction with lipids. Both the heavy and light chain subunits of the neurotoxins were involved in the process. The change in the nature and extent of toxin-lipid interaction occurred in the pH range 4-6 and was not influenced by the presence of polysialogangliosides. The present data are in agreement with the idea that botulinum neurotoxins enter into nerve cells from a low pH intracellular compartment.

Exposure of energy-depleted rat trabeculae to low pH improves contractile recovery: role of calcium

1995 ◽  
Vol 268 (4) ◽  
pp. H1510-H1520 ◽  
Author(s):  
C. van Hardeveld ◽  
V. J. Schouten ◽  
A. Muller ◽  
E. T. van der Meulen ◽  
G. Elzinga
Keyword(s):  
Recovery Period ◽  
Muscle Tension ◽  
Low Ph ◽  
Tyrode Solution ◽  
Normal Medium ◽  
Group Iii ◽  
Group I ◽  
Group Ii ◽  
Saving Effect

The beneficial effect of low pH during cardiac ischemia on reperfusion injury has often been attributed to its energy-saving effect due to inhibition of contraction. The role of low pH on Ca2+ accumulation and muscle tension was assessed in energy-depleted tissue by changing the pH of the medium from 7.4 to 6.2 at onset of rigor development during metabolic inhibition (MI), i.e., in the energy-depleted phase. Cytosolic free Ca2+ ([Ca2+]i) and intracellular H+ (pHi) were measured in rat trabeculae at 20 degrees C with fura 2 and 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein, respectively, and tension was recorded. The preparations were energy depleted by stimulation at 1 Hz in glucose-free Tyrode solution with 2 mM NaCN. Rigor developed within 20 min, indicating energy depletion. Resting [Ca2+]i was followed during 50 min (group I) or 100 min (group II) of rigor, and recovery was followed for 60 min in glucose-containing Tyrode solution at 0.2-Hz stimulation. Resting [Ca2+]i rose within 50 min (group I) but stabilized in the 50- to 100-min period (group II). All preparations from group I (n = 5) resumed contraction in the recovery period but in group II (n = 10) 70% failed to recover, and [Ca2+]i remained elevated compared with those that recovered. An extracellular pH of 6.2, resulting in similar pHi, from onset of rigor development (group III) led to only a modest rise in [Ca2+]i during the 100-min rigor period, and all preparations resumed contraction after approximately 3 min in normal medium. ATP was very low in all groups at the end of MI but was still significantly lower in group II than in groups I and III. A beneficial energy-sparing effect of low pH during the rigor phase can therefore not be excluded. We conclude that 1) the capacity of trabeculae to recover from MI depends on the time period and magnitude of the [Ca2+]i rise in the energy-depleted phase and 2) low pH in energy-depleted trabeculae protects against Ca overload, improving recovery after normalization of perfusion conditions.

scholarly journals Chemoenzymatic synthesis of the pH responsive surfactant octyl β-D-glucopyranoside uronic acid

2019 ◽  
Vol 104 (3) ◽  
pp. 1055-1062 ◽  
Author(s):  
Ngoc T. N. Ngo ◽  
Carl Grey ◽  
Patrick Adlercreutz
Keyword(s):  
Substrate Concentration ◽  
Uronic Acid ◽  
Catalyst System ◽  
Low Ph ◽  
Chemoenzymatic Synthesis ◽  
Ph Responsive ◽  
Ph Values ◽  
Wide Ph Range ◽  
Carboxyl Derivative ◽  
Ph Range

AbstractMethodology was developed to expand the range of benign alkyl glycoside surfactants to include also anionic types. This was demonstrated possible through conversion of the glycoside to its carboxyl derivative. Specifically, octyl β-D-glucopyranoside (OG) was oxidised to the corresponding uronic acid (octyl β-D-glucopyranoside uronic acid, OG-COOH) using the catalyst system T. versicolor laccase/2,2,6,6-tetramethylpiperidinyloxy (TEMPO) and oxygen from air as oxidant. The effects of oxygen supply methodology, concentrations of laccase, TEMPO and OG as well as reaction temperature were evaluated. At 10 mM substrate concentration, the substrate was almost quantitatively converted into product, and even at a substrate concentration of 60 mM, 85% conversion was reached within 24 h. The surfactant properties of OG-COOH were markedly dependent on pH. Foaming was only observed at low pH, while no foam was formed at pH values above 5.0. Thus, OG-COOH can be an attractive low-foaming surfactant, for example for cleaning applications and emulsification, in a wide pH range (pH 1.5–10.0).

An aminoquinoline based biocompatible fluorescent and colourimetric pH sensor designed for cancer cell discrimination

2018 ◽  
Vol 42 (24) ◽  
pp. 19818-19826 ◽  
Author(s):  
Jayanta Mandal ◽  
Pravat Ghorai ◽  
Paula Brandão ◽  
Kunal Pal ◽  
Parimal Karmakar ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Cancer Cell ◽  
Low Cost ◽  
Ph Sensor ◽  
Low Ph ◽  
Cell Permeability ◽  
Ph Range ◽  
Cell Discrimination

A simple, low cost aminoquinoline based pH sensor,HLwas prepared and it works at a low pH range.HLexhibits cell permeability and used as an effective tool for differentiating between normal and cancer cells.

Characteristics of an Acidophilic Bacillus Strain Isolated from Shelf-Stable Juices

1995 ◽  
Vol 58 (3) ◽  
pp. 319-321 ◽  
Author(s):  
SHERI MCINTYRE ◽  
JUDY Y. IKAWA ◽  
NINA PARKINSON ◽  
JOHN HAGLUND ◽  
JENNIFER LEE
Keyword(s):  
Fatty Acid ◽  
Fatty Acid Profile ◽  
Economic Loss ◽  
Low Ph ◽  
Potato Dextrose Agar ◽  
Bacillus Species ◽  
Potato Dextrose Broth ◽  
Bacillus Strain ◽  
Ph Range ◽  
Shelf Stable

An acidophilic sporeformer was isolated from several varieties of shelf-stable juices. The organism sporulated on potato dextrose agar (pH 3.5) at 37°C within 24 hours and grew well in fruit and berry juices. The pH range of growth in potato dextrose broth was 3.0 to 5.3. The D87.8°C' D91.1°C' and D95°C determined in berry juice were 11.0, 3.8, and 1.0 min, respectively. The ability of this organism to grow at low pH and to survive pasteurization poses a threat of economic loss by spoilage to beverage producers. The organism could not be identified based on its characteristics or the fatty acid profile comparison to those of other Bacillus species, including the acidophilic B. acidocaldarius.

Sign in / Sign up

Export Citation Format

Share Document