http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Berkani, (검색결과 7 건)
- 무료
- 기관 내 무료
- 유료
-
NEW BROWDER AND WEYL TYPE THEOREMS
Berkani, Mohammed,Kachad, Mohammed Korean Mathematical Society 2015 대한수학회보 Vol.52 No.2
In this paper we introduce and study the new properties ($W_{\Pi}$), ($UW_{{\Pi}_a}$), ($UW_E$) and ($UW_{\Pi}$). The main goal of this paper is to study relationship between these new properties and other Weyl type theorems. Moreover, we reconsider several earlier results obtained respectively in [11], [18], [14], [1] and [13] for which we give stronger versions.
-
WEYL TYPE-THEOREMS FOR DIRECT SUMS
Berkani, Mohammed,Zariouh, Hassan Korean Mathematical Society 2012 대한수학회보 Vol.49 No.5
The aim of this paper is to study the Weyl type-theorems for the orthogonal direct sum $S{\oplus}T$, where S and T are bounded linear operators acting on a Banach space X. Among other results, we prove that if both T and S possesses property ($gb$) and if ${\Pi}(T){\subset}{\sigma}_a(S)$, ${\PI}(S){\subset}{\sigma}_a(T)$, then $S{\oplus}T$ possesses property ($gb$) if and only if ${\sigma}_{SBF^-_+}(S{\oplus}T)={\sigma}_{SBF^-_+}(S){\cup}{\sigma}_{SBF^-_+}(T)$. Moreover, we prove that if T and S both satisfies generalized Browder's theorem, then $S{\oplus}T$ satis es generalized Browder's theorem if and only if ${\sigma}_{BW}(S{\oplus}T)={\sigma}_{BW}(S){\cup}{\sigma}_{BW}(T)$.
-
WEYL TYPE-THEOREMS FOR DIRECT SUMS
Mohammed Berkani,Hassan Zariouh 대한수학회 2012 대한수학회보 Vol.49 No.5
The aim of this paper is to study the Weyl type-theorems for the orthogonal direct sum $S{\oplus}T$, where S and T are bounded linear operators acting on a Banach space X. Among other results, we prove that if both T and S possesses property ($gb$) and if ${\Pi}(T){\subset}{\sigma}_a(S)$, ${\PI}(S){\subset}{\sigma}_a(T)$, then $S{\oplus}T$ possesses property ($gb$) if and only if ${\sigma}_{SBF^-_+}(S{\oplus}T)={\sigma}_{SBF^-_+}(S){\cup}{\sigma}_{SBF^-_+}(T)$. Moreover, we prove that if T and S both satisfies generalized Browder's theorem, then $S{\oplus}T$ satis es generalized Browder's theorem if and only if ${\sigma}_{BW}(S{\oplus}T)={\sigma}_{BW}(S){\cup}{\sigma}_{BW}(T)$.
-
NEW BROWDER AND WEYL TYPE THEOREMS
Mohammed Berkani,Mohammed Kachad 대한수학회 2015 대한수학회보 Vol.52 No.2
In this paper we introduce and study the new properties (W∏), (UW∏a), (UWE) and (UW∏). The main goal of this paper is to study relationship between these new properties and other Weyl type theorems. Moreover, we reconsider several earlier results obtained respec- tively in [11], [18], [14], [1] and [13] for which we give stronger versions.
-
Ni2+ reduction under solar irradiation over CuFe2O4/TiO2 catalysts
Mohamed Trari,Maamar Fedailaine,Sabrina Berkani 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.7
The photo-electrochemical characterization of the hetero-system CuFe2O4/TiO2 was undertaken for the Ni2+ reduction under solar light. The spinel CuFe2O4 was prepared by nitrate route at 940 oC and the optical gap (1.66 eV) was well matched to the sun spectrum. The flat band potential (−0.21 VSCE) is more cathodic than the potential of Ni2+/Ni couple (−0.6 VSCE), thus leading to a feasible nickel photoreduction. TiO2 with a gap of 3.2 eV is used to mediate the electrons transfer. The reaction is achieved in batch configuration and is optimized with respect to Ni2+ concentration (30 ppm); a reduction percentage of 72% is obtained under sunlight, the Ni2+ reduction is strongly enhanced and follows a first order kinetic with a rate constant of 4.6×10−2 min−1 according to the Langmuir-Hinshelwood model.
-
Bellebcir Anfal,Merouane Fateh,Chekroud Karim,Bounabi Hadjira,Vasseghian Yasser,Kamyab Hesam,Chelliapan Shreeshivadasan,Klemeš Jiří Jaromír,Berkani Mohammed 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.10
Biosurfactants have been found capable of replacing synthetic surfactants which include ongoing bioprospecting of biosurfactant-producing bacteria as well as process optimization for maximum biosurfactant production. In this study, five morphologically distinct actinomycete strains isolated from hydrocarbon-polluted soil collected from an oil spill surface in Southeastern Algeria were tested for their ability to produce biosurfactants using preliminary biosurfactant screening assays. The 7SDS strain was selected as the most promising biosurfactant producer due to its greatest oil displacement diameter (7.83±0.15 cm), emulsification index (59.66±0.44%), and enhanced surface tension reduction (30.04±0.51 mN/m); it was identified as Streptomyces thinghirensis 7SDS using 16S rDNA sequence analysis. The 7SDS strain’s biosurfactant production was optimized using the Face-centered central composite design (CCD) based on response surface methodology (RSM). To this end, five independent factors, i.e., residual frying oil, used engine oil, whey, CS filtrate, and incubation time, were assessed. The RSM’s model predicted a surface tension of 27.48 mN/m using 2.44% (v/v) residual frying oil, 0.35% (v/v) used motor oil, 0.83% (v/v) whey, 0.39% (v/v) CS filtrate, and an incubation time of 219.3 h. The optimized medium produced 8.79 g/L of biosurfactant. The produced biosurfactant allows one to reduce the surface tension of distilled water from 70.86 mN/m to 27.96 mN/m at a critical micelle concentration of 350 mg/L, even over a wide range of pH (2.0–12.0), temperature (4–120 °C), and salinity (2–12%, W/V). Biochemical (Biuret, phenol-sulfuric acid, and phosphate tests) and compositional (FTIR and GC-MS) characterizations confirmed the phospholipid nature of the produced biosurfactant. Interestingly, the produced BS demonstrated significant antimicrobial activity as well as intriguing activity in removing hydrocarbons from polluted soil. Because of their appealing biological properties, strain 7SDS and its biosurfactant are attractive targets for a variety of applications such as biomedicine and environmental ones.
-
Delloula Lakhdari,Nadjem Lakhdari,Ines Laourari,Abderrahmane Berchi,YoungKwon Park,Yasser Vasseghian,Mohammed Berkani 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.124 No.-
In this study, three types of electrodes based on polyvinyl alcohol (PVA)/ polyaniline (PANI) are synthesizedand their effects on the electro-oxidation of methanol (MeOH) are investigated. Composite electrodesof PVA/PANI-Ni, PVA/PANI-Cu, and PVA/PANI-NiCu are synthesized via the in-situpolymerization of aniline, Cu, Ni, and NiCu (Ni80Cu20 alloy) particles in the presence of PVA. Opticaland chemical compositions and morphological characteristics of composite films are determined usingUV–Vis, FTIR, SEM, and TGA analysis. The electrode degradation efficiency of MeOH following oxidationand the elimination of toxins from the solution by voltammetry and chronopotentiometry is also investigated. The results indicate that PVA/PANI-NiCu performs better than PVA/PANI-Ni electrode. The degradationof MeOH in an alkaline medium is monitored using UV–visible spectroscopy under a currentdensity of 2.18 mAcm2 with a stock solution of 0.1 M MeOH for 120 min. The toxicities of MeOH andthe generated by-products were tested and confirmed through a growth-inhibition test againstStaphylococcus aureus ATCC 6538 using the disk-diffusion method; the obtained results confirmed theeffectiveness of our process.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
