Vezana stanja elektrona i šupljine u valjkastoj kvantnoj točki

The ground-state energies of an electron and of a hole in a finite-potential quantum dot disc of GaAs are calculated. Solving the Schrödinger equation for the two particles separately, we calculated the first two excited states for each one. To study the effect of the disc dimensionality on the eigen-energies, we considered different discs with different values of radius (R) and width (L). Discussing the potential effect, we examined the eigen-value behaviour at different values of the barrier heights. The corresponding wave functions are obtained.Izračunali smo energije osnovnih stanja elektrona i šupljine u konačnom potencijalu valjkaste kvantne točke u GaAs. Rješavanjem Schrodingerove jednadžbe posebno za svaku od čestica, izračunali smo prvo i dva viša stanja za svaku česticu. Radi proučavanja učinka veličine valjka na svojstvene energije, razmatrali smo valjke različitih polumjera i duljine. Razmatrali smo utjecaj potencijala ispitivanjem ovisnosti svojstvenih vrijednosti za tri vrijednosti visine barijere. Izveli smo odgovarajuće valne funkcije

Vezana stanja elektrona i šupljine u valjkastoj kvantnoj točki

The ground-state energies of an electron and of a hole in a finite-potential quantum dot disc of GaAs are calculated. Solving the Schrödinger equation for the two particles separately, we calculated the first two excited states for each one. To study the effect of the disc dimensionality on the eigen-energies, we considered different discs with different values of radius (R) and width (L). Discussing the potential effect, we examined the eigen-value behaviour at different values of the barrier heights. The corresponding wave functions are obtained.Izračunali smo energije osnovnih stanja elektrona i šupljine u konačnom potencijalu valjkaste kvantne točke u GaAs. Rješavanjem Schrodingerove jednadžbe posebno za svaku od čestica, izračunali smo prvo i dva viša stanja za svaku česticu. Radi proučavanja učinka veličine valjka na svojstvene energije, razmatrali smo valjke različitih polumjera i duljine. Razmatrali smo utjecaj potencijala ispitivanjem ovisnosti svojstvenih vrijednosti za tri vrijednosti visine barijere. Izveli smo odgovarajuće valne funkcije

Eksitonska stanja u kvantnoj točki

The exciton binding energies in finite-potential quantum dot discs of GaAs are obtained and the eigenstates and the eigenvalues of the exciton are calculated. We present the exciton binding energy for different values of the disc radius (R) and the disc half-width (L/2). The exciton-state stability for large and small sizes of the dot is discussed. We compare our results with the existing theoretical and experimental results. Our results give good estimates for the optimal quantum dot disc geometry, and represent useful data in studies of the optical properties of quantum dots in nano-scale devices.Izračunali smo energiju vezanja, svojstvena stanja i svojstvene vrijednosti eksitona u kvantnoj točki s konačnim potencijalom. Opisujemo energiju vezanja eksitona za više vrijednosti polumjera (R) i poluširine (L/2) diska. Raspravljamo stabilnost eksitona za male i veće dimenzije diska. Uspoređujemo naše rezultate s poznatim drugim teorijskim i eksperimentalnim rezultatima. Naši rezultati daju dobre ocjene za povoljnu veličinu diska kvantne točke, i predstavljaju korisne podatke za proučavanje optičkih svojstava kvantnih točaka u napravama nano veličine

Eksitonska stanja u kvantnoj točki

The exciton binding energies in finite-potential quantum dot discs of GaAs are obtained and the eigenstates and the eigenvalues of the exciton are calculated. We present the exciton binding energy for different values of the disc radius (R) and the disc half-width (L/2). The exciton-state stability for large and small sizes of the dot is discussed. We compare our results with the existing theoretical and experimental results. Our results give good estimates for the optimal quantum dot disc geometry, and represent useful data in studies of the optical properties of quantum dots in nano-scale devices.Izračunali smo energiju vezanja, svojstvena stanja i svojstvene vrijednosti eksitona u kvantnoj točki s konačnim potencijalom. Opisujemo energiju vezanja eksitona za više vrijednosti polumjera (R) i poluširine (L/2) diska. Raspravljamo stabilnost eksitona za male i veće dimenzije diska. Uspoređujemo naše rezultate s poznatim drugim teorijskim i eksperimentalnim rezultatima. Naši rezultati daju dobre ocjene za povoljnu veličinu diska kvantne točke, i predstavljaju korisne podatke za proučavanje optičkih svojstava kvantnih točaka u napravama nano veličine

Efficacy of tenofovir disoproxil fumarate therapy in nucleoside-analogue naive Iranian patients treated for chronic hepatitis B

Background: Tenofovir disoproxil fumarate (TDF) is a new effective treatment option for patients with chronic hepatitis B (CHB). Objectives: To evaluate TDF efficacy in nucleos(t)ide analogues (NAs)-naive Iranian patients with CHB. Patients and Methods: The NA-naive patients received TDF for at least six months. The primary endpoint was the proportion of patients achieving a complete virological response (CVR) during the treatment. Multivariate Cox regression analysis determined predictive factors independently associated with the time to CVR. The secondary endpoints were biochemical and serological responses, frequency of virological breakthrough, genotypic resistance development, safety and tolerability. Results: In all, 93 patients (64.5 hepatitis B e antigen HBeAg-negative) were eligible. Of these, 70 patients completed 24 months of treatment. The cumulative CVR rates in HBeAg-negative and HBeAg-positive patients were 87% versus 53% at 24 months, respectively. The multivariate Cox regression model showed only HBeAg positivity at baseline and a high baseline HBV DNA level were independent factors predicting a CVR. No patient achieved hepatitis B surface antigen (HBsAg) and HBeAg loss or seroconversion and no virologic breakthrough occurred. A new amino acid substitution (rtD263E) was observed to develop in 60% of patients with viremia. Conclusions: The cumulative CVR rates showed that patients with HBeAg-negative have better virologic respond than those with HBeAg-positive during the same period. The rtD263E mutation might be associated with partial resistance to TDF. © 2015, Kowsar Corp

Ionic Liquid 3-Methyl-1-sulphonic Acid Imidazolium Chloride {[Msim]Cl}: A Highly Efficient, Mild and Green Catalyst for the Synthesis of β-Acetamido Ketones

Brønstedacidic ionic liquid 3-methyl-1-sulphonic acid imidazolium chloride {[Msim]Cl} is utilized as a highly efficient, inexpensive, mild and green catalyst for the synthesis of β-acetamido ketones by the one-pot multi-component coupling between acetophenones, arylaldehydes, acetonitrile and acetyl chloride at room temperature. Under these conditions, the title compounds are produced in high to excellent yields and in relatively short reaction times. In addition, this method is superior to reported methods, for the synthesis of β-acetamido ketones and is applicable for the synthesis of tris(β-acetamido ketone).Keyword: 3-Methyl-1-sulphonic acid imidazolium chloride {[Msim]Cl}, β-acetamido ketone, Brønsted acidic catalyst, ionic liquid, one-pot multi-component reaction, acetophenon

Risk factor investigation for cardiovascular health through WHO STEPS approach in Ardabil, Iran

Objectives: Reliable evidence is the keystone for any noncommunicable disease (NCD) prevention plan to be initiated. In this study we carried out a risk factor investigation based on the WHO Stepwise approach to Surveillance (STEPS). Methods: The study was conducted on 1000 adults between 15 and 64 years of age living in Ardabil province, north-west Iran during 2006, based on the WHO STEPS approach to surveillance of risk factors for NCD. At this stage only the first and second steps were carried out. Data were collected through standard questionnaires and methods analyzed using STATA version 8 statistical software package. Results: 29.0% of men and 2.6% of women were current daily tobacco smokers. The mean number of manufactured cigarettes smoked per day was 18.9 among current daily smokers. Smoking was most prevalent among men of low-income families and those of lower education The mean body mass index (BMI) was 26.6 kg/m2, and was significantly correlated with systolic blood pressure. 58.9% were overweight or obese; 18.0% had raised blood pressure and 3.7% had isolated systolic hypertension. The mean number of servings of fruit consumed per day was 1.1; 33.1% had low levels of activity. Combined risk factor analysis showed that 4.1%of participants were in the low-risk group (up to 5.1% among men and 3.2% among women).Those in the high-risk group comprised 25.6% in the 25- to 44-year age group and 49.7%in the 45- to 64-year age group. Mean BMI increased by age in both sexes at least at the firstthree decades of adult life. Conclusion: Based on observed status of risk for cardiovascular health, burden of cardiovascular diseases is expected to increase if an effective prevention strategy is not undertaken