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Govt. of India Trust : E/11049/Rajkot
Income tax of India 80G : AADTK8161HF20221
Income tax of India 12A : AADTK8161HE20217


Volume 1 – Issue 1 – 2020

The Transport Mechanism In The Heterostructure GaAs/AlGaAs At Very Low Temperature In The Vicinity Of The Metal Insulator Transition

Asmaa Chakhmane1,2*, Hassan El Idrissi2, Abdelhamid El Kaaouachi3, Mohamed Errai3

1Pluridisciplinary Research and Innovation Laboratory (LPRI), EMSI Casablanca, (MOROCCO)
2Laboratory EEA&TI, Faculty of Sciences and Technology Mohammedia, University Hassan II Casablanca, Mohammedia, (MOROCCO)
3Physics Department, Faculty of Sciences, University Ibn Zohr, Agadir, (MOROCCO)

PAGE NO: 67-73


The objective of this work, is to study the transport mechanism contributing to the low temperature electrical conductivity of a two-dimensional GaAs hole gas in the metal and insulating side of the Metal Insulator Transition, for T less than 1K. We reanalyzed the data obtained by Qiu et al published in [R. L.J. Qiu, X.A.A. Gao, L.N. Pfeiffer and K. W. West, PRL 108, 106404 (2012)]. In insulating systems, the electrical transport in a disordered system occurs by the phenomenon of Variable Range Hopping (VRH), which is widely observed, analyzed in several studies and described by  s = s0exp(-T0/T)p. In this case, the holes move between localized states while traveling different distances, giving rise to two regimes: the Efros & Shklovskii regime (ES VRH) and the Mott regime (Mott VRH). For the metal samples, we studied the temperature dependence of the resistivity r and its impact on the metallic behavior of the system with high hole densities (when dr/dT > 0), beyond a critical density (psc=0,8×1010cm-2). The results were verified graphically and confirmed by the percentage of deviation method.


Exploratory Environmental Science Research

Volume 1 – Issue 1 – 2020


Anaerobic/Aerobic Sequential Treatment Of Chloramphenicole Antibiotic Using Anaerobic Baffled And Aerobic Sludge Reactors

Delýa Teresa Sponza*, Seçil Tüzün

Dokuz Eylül University, Engineering Faculty, Environmental Engineering Department,
Buca Kaynaklar Campus, Týnaztepe, BUCA-ÝZMÝR, (TURKEY)

PAGE NO: 115-159


In this study  a sequential anaerobic baffled (ABR) and  an aerobic completely sirred sludge reactor (CSTR) system was used to treat the chloramphenicole antibiotic at different  HRTs. The maximum COD removal efficiency was 94,40% until HRT of 19,2 days. The maximum total, methane gas and methane percentage were found as 547,2 L/day, 504 L/dayand 58%, respectively, atthech loramphenicole concentration of 130 mg/L in ABR. The total gas and methane gas production rates increased from 259,2 to 547,2 L/day and from 216 to 489,6 L/day, respectively as the HRT was decreased from 38,4 days to 19,2 days. Meanwhile the methane percentages increased from 38% up to 58%, until at a HRT of 12,8 days. However the methane percentages decreased from 58% to 42% as the HRT decreased from 12,8 to 7,68 days.The COD removal efficiency in sequential anaerobic ABR/aerobic CSTR reactor syste mas 98,12% at a HRT of 19,2 days. For maximum COD removal efficiency (E=98,12%) the optimum HRT was found as 19,2 days. In Daphnia magna acute toxicity test the wastewater containing 130 mg/L of chloramphenicole concentration was found to be toxic (% inhibition = 100%) in the influent of anaerobic ABR /aerobic CSTR reactor system. The acute toxicity reduction in sequential ABR/ CSTR reactor system effluent was 95% at a HRT of 38,4 days. The kinetic constants in the Monod and Grau kinetic models were found to be meaning full for chloramphnicole degradation. Y and Ks was 13,532 mgVSS/mgCOD and 0,071 mg/L, respectively with high regression coefficient (R2=0,98) for Monod kinetic model. Similarly, the ks and a was 0,055 day-1 and 1,2975 day, respectively with high regression coefficient (R2=0,98) in Grau kinetic model for chloramphenicole removal.