scholarly journals Capacitance and conductance oscillations from electron tunneling into high energy levels of a quantum well in a p−i−n diode

2022 ◽  
Vol 105 (3) ◽  
Author(s):  
S. Parolo ◽  
M. Lupatini ◽  
E. Külah ◽  
C. Reichl ◽  
W. Dietsche ◽  
...  
Keyword(s):  
Quantum Well ◽  
Electron Tunneling ◽  
Energy Levels ◽  
High Energy

ORIGIN OF HYSTERESIS AND PLATEAU-LIKE BEHAVIOR OF THE I-V CHARACTERISTICS OF RESONANT TUNNELING DIODES

2000 ◽  
Vol 14 (04) ◽  
pp. 411-426 ◽  
Author(s):  
PEIJI ZHAO ◽  
H. L. CUI ◽  
D. L. WOOLARD ◽  
K. L. JENSEN ◽  
F. A. BUOT
Keyword(s):  
Energy Level ◽  
Quantum Well ◽  
Resonant Tunneling ◽  
Electron Tunneling ◽  
Energy Levels ◽  
Three Dimensional ◽  
Physical Factors ◽  
Tunneling Diodes ◽  
Tunneling Devices ◽  
Resonant Tunneling Devices

In terms of numerical calculation of the coupled Wigner function–Poisson equations, the explanation to the origin of hysteresis and plateau-like behavior of the I-V characteristics of double barrier resonant tunneling devices is put forth. Several basic physical factors play key roles in the process of electron tunneling. Among these the most important factors are the interference of the injected and the reflected electron waves which leads to the formation of an emitter quantum well, the coupling between the energy level in the main quantum well and that in the emitter quantum well, and the coupling between the energy level in the main quantum well and the conduction b and edge or the three-dimensional states in the emitter. The interplay of these factors determines the form of the I-V curve of the resonant tunneling structure. The coupling between the energy levels in the emitter quantum-well and the main quantum-well leads to the plateau behavior of the I-V curves. The strength of the coupling determines the average slope of the plateau-like region in the I-V curve. The bias domain that the coupling exists determines the length of the plateau-like structure in the I-V curve. The domain can be controlled by adjusting the width of the barriers. The hysteresis is shown to be a manifestation of the above-mentioned energy level coupling, the coupling between the energy level in the main quantum well and the conduction b and edge or the three-dimensional states in the emitter, and the quantitative accumulation and distribution of electrons in the emitter region. This work provides new insight for underst and ing the nonlinear I-V behavior and establishes a foundation for the future analysis of bistability and oscillation behavior in resonant tunneling structures.

scholarly journals The Use of Lasers in Dental Materials: A Review

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3370
Author(s):  
Emmanouil-George C. Tzanakakis ◽  
Evangelos Skoulas ◽  
Eudoxie Pepelassi ◽  
Petros Koidis ◽  
Ioannis G. Tzoutzas
Keyword(s):  
Energy Levels ◽  
Dental Materials ◽  
High Strength ◽  
Surface Characteristics ◽  
High Energy ◽  
Zirconia Ceramics ◽  
Material Management ◽  
Laboratory Procedures ◽  
Laser Devices ◽  
Exact Point

Lasers have been well integrated in clinical dentistry for the last two decades, providing clinical alternatives in the management of both soft and hard tissues with an expanding use in the field of dental materials. One of their main advantages is that they can deliver very low to very high concentrated power at an exact point on any substrate by all possible means. The aim of this review is to thoroughly analyze the use of lasers in the processing of dental materials and to enlighten the new trends in laser technology focused on dental material management. New approaches for the elaboration of dental materials that require high energy levels and delicate processing, such as metals, ceramics, and resins are provided, while time consuming laboratory procedures, such as cutting restorative materials, welding, and sintering are facilitated. In addition, surface characteristics of titanium alloys and high strength ceramics can be altered. Finally, the potential of lasers to increase the adhesion of zirconia ceramics to different substrates has been tested for all laser devices, including a new ultrafast generation of lasers.

Effects of dietary energy levels on ovarian and uterine expression of IGF-1R and EGFR mRNA in prepubertal gilts

2008 ◽  
Vol 5 (2) ◽  
pp. 159-164
Author(s):  
Li Bo ◽  
Zhang He ◽  
Zhang Jing ◽  
Sun Bo-Xing ◽  
Chen Lu ◽  
...  
Keyword(s):  
Growth Factor ◽  
Energy Intake ◽  
Energy Levels ◽  
Growth Factor Receptor ◽  
High Energy ◽  
Diet Group ◽  
Free Access ◽  
Access To Water ◽  
Moderate Energy ◽  
Epidermal Growth

AbstractNine prepubertal gilts (JunMu No. 1) were randomly allocated into three groups (n=3) and fed with a high-energy diet (Group H), a low-energy diet (Group L), or a moderate-energy diet (Group M) for 14 days. Free access to water was provided throughout the research period. Ovaries and uteri were collected after the energy treatments, and processed for determination of the absolute quantities of insulin-like growth factor receptor (IGF-1R) and epidermal growth factor receptor (EGFR) mRNA, using real-time polymerase chain reaction (PCR). The expression of IGF-1R and EGFR mRNA in ovaries and uteri was significantly ranked as: Group H>Group M>Group L (P<0.05). This result suggests that high energy intake markedly enhanced the ovarian and uterine expression of IGF-1R and EGFR in prepubertal gilts, whereas insufficient energy intake markedly inhibited such expression. IGF-1R and EGFR may be involved in mediating the effects of energy intake on the development of the reproductive system in prepubertal gilts.

In silico study of binding affinity of nitrogenous bicyclic heterocycles: fragment-to-fragment approach

2020 ◽  
Vol 15 (2) ◽  
pp. 49-59
Author(s):  
Yevheniia Velihina ◽  
Nataliya Obernikhina ◽  
Stepan Pilyo ◽  
Maryna Kachaeva ◽  
Oleksiy Kachkovsky ◽  
...  
Keyword(s):  
Amino Acids ◽  
Binding Affinity ◽  
In Silico ◽  
Density Functional ◽  
Energy Levels ◽  
Aromatic Amino Acids ◽  
Electron System ◽  
High Energy ◽  
Proton Donor ◽  
Stabilization Energy

The binding affinity of model aromatic amino acids and heterocycles and their derivatives condensed with pyridine were investigated in silico and are presented in the framework of fragment-to-fragment approach. The presented model describes interaction between pharmacophores and biomolecules. Scrupulous data analysis shows that expansion of the π-electron system by heterocycles annelation causes the shifting up of high energy levels, while the appearance of new the dicoordinated nitrogen atom is accompanied by decreasing of the donor-acceptor properties. Density Functional Theory (DFT) wB97XD/6-31(d,p)/calculations of π-complexes of the heterocycles 1-3 with model fragments of aromatic amino acids, which were formed by π-stack interaction, show an increase in the stabilization energy of π-complexes during the moving from phenylalanine to tryptophan. DFT calculation of pharmacophore complexes with model proton-donor amino acid by the hydrogen bonding mechanism (H-B complex) shows that stabilization energy (DE) increases from monoheterocycles to their condensed derivatives. The expansion of the π-electron system by introducing phenyl radicals to the oxazole cycle as reported earlier [18] leads to a decrease in the stabilization energy of the [Pharm-BioM] complexes in comparison with the annelated oxazole by the pyridine cycle.

Metabolic and energy correlates of intracellular pH in progressive fatigue of squid (L. brevis) mantle muscle

1996 ◽  
Vol 271 (5) ◽  
pp. R1403-R1414 ◽  
Author(s):  
H. O. Portner ◽  
E. Finke ◽  
P. G. Lee
Keyword(s):  
Free Energy ◽  
Critical Velocity ◽  
Energy Levels ◽  
High Energy ◽  
Swimming Velocity ◽  
High Energy Phosphates ◽  
Energy Status ◽  
Intracellular Acidosis ◽  
Model Calculations

Squid (Lolliguncula brevis) were exercised at increasing swimming speeds to allow us to analyze the correlated changes in intracellular metabolic, acid-base, and energy status of the mantle musculature. Beyond a critical swimming velocity of 1.5 mantle lengths/s, an intracellular acidosis developed that was caused by an initial base loss from the cells, the onset of respiratory acidification, and, predominantly, octopine formation. The acidosis was correlated with decreasing levels of phospho-L-arginine and, thus, supported ATP buffering at the expense of the phosphagen. Monohydrogenphosphate, the actual substrate of glycogen phosphorylase accumulated, enabling glycogen degradation, despite progressive acidosis. In addition to octopine, succinate, and glycerophosphate accumulation, the onset of acidosis characterizes the critical velocity and indicates the transition to a non-steady-state time-limited situation. Accordingly, swimming above the critical velocity caused cellular energy levels (in vivo Gibbs free energy change of ATP hydrolysis) to fall. A minimal value was reached at about -45 kJ/mol. Model calculations demonstrate that changes in free Mg2+ levels only minimally affect ATP free energy, but minimum levels are relevant in maintaining functional concentrations of Mg(2+)-complexed adenylates. Model calculations also reveal that phosphagen breakdown enabled L. brevis to reach swimming speeds about three times higher than the critical velocity. Comparison of two offshore squid species (Loligo pealei and Illex illecebrosus) with the estuarine squid L.brevis indicates that the latter uses a strategy to delay the exploitation of high-energy phosphates and protect energy levels at higher than the minimum levels (-42 kJ/mol) characterizing fatigue in the other species. A more economical use of anaerobic resources and an early reduction in performance may enable L. brevis to tolerate more extreme environmental conditions in shallow estuarine waters and even hypoxic environments and to prevent a fatal depletion of energy stores.

The protein and energy nutrition of the pig. V. The effect of varying the protein and energy levels in the ‘finishing diets’ of heavy pigs

1965 ◽  
Vol 65 (3) ◽  
pp. 405-409 ◽  
Author(s):  
D. W. Robinson
Keyword(s):  
Crude Protein ◽  
Energy Levels ◽  
Live Weight ◽  
High Energy ◽  
Feeding Trial ◽  
Large White ◽  
High Energy Level ◽  
Finishing Diets ◽  
Main Effects ◽  
Carcass Measurement

1. A feeding trial was carried out using fortyeight Large White pigs, individually fed in a Danish type piggery. Six different diets prepared at two levels of digestible energy and three levels of crude protein were fed to eight replicates consisting of four hogs and four gilts per replicate. A record was maintained of the weekly live-weight gain and food was given at a defined restricted level in relation to the live weight. Carcass quality was assessed by complete dissection into visible lean, fat and bone etc.2. Of the main effects, energy, supply was without significant effect upon growth, food conversion efficiency (FCE) or any carcass characteristics except body length which was increased with a high energy level. The protein level in the diet had a significant effect upon the percentage of carcass lean and the killing-out percentage, the higher levels of protein increasing both these measurements significantly. Gilts were significantly superior to hogs in every carcass measurement although hogs grew significantly faster.

scholarly journals Changes in white muscle transcriptome induced by dietary energy levels in two lines of rainbow trout (Oncorhynchus mykiss) selected for muscle fat content

2009 ◽  
Vol 103 (5) ◽  
pp. 629-642 ◽  
Author(s):  
Catherine-Ines Kolditz ◽  
Elisabeth Plagnes-Juan ◽  
Edwige Quillet ◽  
Florence Lefèvre ◽  
Françoise Médale
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
White Muscle ◽  
Energy Levels ◽  
High Energy ◽  
Fat Content ◽  
Fat Deposition ◽  
Dietary Energy ◽  
Expression Change ◽  
Vldl Receptor

Energy intake and genetic background are major determinants of muscle fat content in most animals, including man. We combined genetic selection and dietary energy supply to study the metabolic pathways involved in genetic and nutritional control of fat deposition in the muscle of rainbow trout (Oncorhynchus mykiss). Two experimental lines of rainbow trout, selected for lean (L) or fat (F) muscle, were fed with diets containing either 10 or 23 % lipids from the first feeding, up to 6 months. At the end of the trial, trout exhibited very different values of muscle fat content (from 4·2 to 10·1 % wet weight). Using microarrays made from a rainbow trout multi-tissue cDNA library, we analysed the molecular changes occurring in the muscle of the two lines when fed the low-energy or high-energy diet. The results from microarray analysis revealed that eleven metabolism-related genes were differentially expressed according to the diet while selection resulted in expression change for twenty-six genes. The most striking observation was the increased level of transcripts encoding the VLDL receptor and fatty acid translocase/CD36 following both the high-fat diet and upward selection for muscle fat content, suggesting that these two genes are relevant molecular markers of fat deposition in the white muscle of rainbow trout.

scholarly journals Radiation Sterilization: Dose Is Dose

2020 ◽  
Vol 54 (s1) ◽  
pp. 45-52
Author(s):  
Joyce M. Hansen ◽  
Niki Fidopiastis ◽  
Trabue Bryans ◽  
Michelle Luebke ◽  
Terri Rymer
Keyword(s):  
Energy Level ◽  
Energy Levels ◽  
Radiation Energy ◽  
Biological Indicators ◽  
High Energy ◽  
Microbial Inactivation ◽  
Radiation Sterilization ◽  
Dose Rates ◽  
Radiation Sources ◽  
Radiation Sterilization Dose

Abstract In the radiation sterilization arena, the question often arises as to whether radiation resistance of microorganisms might be affected by the energy level of the radiation source and the rate of the dose delivered (kGy/time). The basis for the question is if the microbial lethality is affected by the radiation energy level and/or the rate the dose is delivered, then the ability to transfer dose among different radiation sources could be challenged. This study addressed that question by performing a microbial inactivation study using two radiation sources (gamma and electron beam [E-beam]), two microbial challenges (natural product bioburden and biological indicators), and four dose rates delivered by three energy levels (1.17 MeV [gamma], 1.33 MeV [gamma], and 10 MeV [high-energy E-beam]). Based on analysis of the data, no significant differences were seen in the rate of microbial lethality across the range of radiation energies evaluated. In summary, as long as proof exists that the specified dose is delivered, dose is dose.

Sign in / Sign up

Export Citation Format

Share Document