Chebyshev type inequalities involving extended generalized fractional integral operators

In this paper, mainly by using the extended generalized fractional integral operator that involve a further extension of Mittag-Leffler function in the kernel, we obtain several fractional Chebyshev type integral inequalities. So, results of Dahmani et al. from [4] are generalized. Also, it is point out that new results are obtained for different fractional integral operators with the help of special selection of parameters

Optimization of some cations for removal of arsenic from groundwater by electrocoagulation process

This study dealt with investigation of arsenic removal from groundwater using electrocoagulation (EC) method in a batch mode by the Box-Behnken experimental design method. Effects of some cations like Ca, Fe, Mg, Mn and operating time on the removal were explored by an air injected EC reactor. The combined effects of these variables were analyzed by the quadratic model for predicting the highest removal efficiency of arsenic from groundwater. The arsenic removal efficiency was found to be dependent on increase with operating time and concentrations of Ca, Mg, Fe and lower concentration of Mn. When operating variables were considered as minimum operating cost and maximum removal efficiency, the optimum operating parameters were determined to be 132 mg/L of CCa, 55 mg/L of CMg, 4.5 mg /L of CFe, 4.5 mg/L of CMn and operating time of 3 min to meet the target concentration of <10 μg/L. Values of removal efficiency and operating cost at the optimum conditions were 95.1% and 0.041 $/m3

Synthesis and organic solar cell performance of BODIPY and coumarin functionalized SWCNT or graphene oxide nanomaterials

The synthesis and characterization of new hybrid materials based on reduced graphene oxide (rGO) or single walled carbon nanotubes (SWCNTs) covalently functionalized by 4,4-difluoro-8-(4-propynyloxy)-phenyl-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene (BODIPY) (2) or 7-(prop-2-yn-1-yloxy)-3-(3,4,5-trimethoxyphenyl)-coumarin (4) as light harvesting groups were described. The organic solar cell performances of these novel nanomaterials in P3HT:PCBM blend were investigated. These covalently bonded hybrid materials (Reduced graphene oxide:BODIPY (GB), reduced graphene oxide:Coumarin (GC), SWCNTs:BODIPY (CB) and SWCNTs:Coumarin (CC)) were prepared by azide-alkyne Huisgen cycloaddition (Click) reaction between azide bearing SWCNTs or rGO and terminal ethynyl functionalized BODIPY (2) or coumarin (4) derivatives. The formation of novel nanomaterials was confirmed by the FT-IR, UV-Vis and Raman spectroscopies and thermogravimetric analysis. The best performance on P3HT:PCBM organic solar cell was produced by SWCNTs:Coumarin (CC) hybrids which was coated on a indium tin oxide coated polyethylene terephthalate film (ITO-PET)). The reference device based on P3HT:PCBM blend without CC showed power conversion efficiency (PCE) of 1.16%, FF of 35% and short-circuit current density (Jsc) of 5.51 mA.cm-2. The reference device with CC hybrids within P3HT:PCBM blend increased the values significantly to 1.62% for PCE, 40% for FF and 6.8 mA.cm-2 for Jsc

Effect of covalent and non-covalent linking of zinc(II) phthalocyanine functionalised carbon nanomaterials on the sensor response to ammonia

In this work, a comparative study of the sensor response of single walled carbon nanotubes (SWCNTs) and reduced graphene oxide (rGO) covalently and non-covalently functionalised with1-[N-(2-ethoxyethyl)-4-pentynamide]-8(11),15(18),22(25)-tris-{2-[2-(2-ethoxyethoxy) ethoxy]-1-[2-((2-ethoxy ethoxy)-ethoxy)methyl]ethyloxy}zinc(II) phthalocyanine (ZnPc) to ammonia is carried out. It was shown that in the case of SWCNT-based materials both covalent and non-covalent functionalisation with zinc(II) phthalocyanine leads to the increase of the sensor response toward NH3, while functionalisation of reduced graphene oxide causes a decrease in the response. At the same time both covalent and non-covalent linking of zinc(II) phthalocyanine leads to twofold decrease of the sensor recovery times. The sensor response of the carbon nanomaterial (single walled carbon nanotubes or reduced graphene oxide) hybrids covalently functionalised with zinc(II) phthalocyanine is several times higher than in the case of non-covalent linking of zinc(II) phthalocyanine to these nanomaterials, which is in good correlation with the number of zinc(II) phthalocyanine molecules adsorbed onto the SWCNT and rGO walls. © 2017 Elsevier B.V

Preparation of single wall carbon nanotube-pyrene 3D hybrid nanomaterial and its sensor response to ammonia

In this work, the structural features and sensor response toward ammonia of a three dimensional (3D) SWCNTs material covalently functionalised with 1,6-diethynylpyrene were studied. The target SWCNTs hybrid material was prepared by the reaction of azido substituted SWCNTs with the 1,6-diethynylpyrene containing double terminal alkyne groups via the azide-alkyne Huisgen cycloaddition (Click) reaction. The structure of the 1,6-diethynylpyrene compound was determined by different spectroscopic methods such as FT-IR, 1H-NMR, MALDI-TOF mass, fluorescence and UV–Visible, while its SWCNT-Pyrene 3D hybrid material was characterized by FT-IR, Raman, UV-Visible spectroscopies and thermogravimetric analysis. The morphology of the hybrid films was investigated by scanning electron microscope (SEM). The sensing performance of the SWCNT-Pyrene 3D hybrid material was studied against low-concentrations of NH3 in the range of 0.1-40 ppm by measuring changes in the films' conductivity at different levels of relative humidity. The reversible electrical sensor response toward ammonia was observed both in the case of SWCNT and SWCNT-Pyrene 3D hybrid films however the response values of SWCNT-Pyrene 3D hybrid film were higher than those of SWCNT

Adsorption of Cobalt(II) Ions from Aqueous Solution onto Activated Carbon Prepared from Hazelnut Shells

Activated carbon prepared from hazelnut shells was used to remove Co(II) from aqueous solution by adsorption. Batch-mode adsorption experiments were carried out varying parameters such as the initial metal ion concentration (13.30–45.55 mg/l), agitation speed (50–200 rpm), pH (2–8), temperature (293–323 K) and particle size (0.80–1.60 mm). The kinetics of the adsorption of Co(II) followed the pseudo-second-order equation, being pH-dependent since the removal rate increased with the pH value of the aqueous solution. The adsorption equilibrium data obeyed the Langmuir isotherm. The adsorption capacity (Q 0 ) calculated from the Langmuir isotherm was 13.88 mg Co(II)/g carbon at 303 K employing a pH value of 6 and a particle size of 1.00–1.20 mm. The thermodynamic parameters evaluated for the carbon revealed that the adsorption of Co(II) was endothermic in nature

Etkinlik ölçümünde veri zarflama analizi ve Malmquist verimlilik endeksi ile Türk tekstil sektöründe bir uygulama

ETKİNLİK ÖLÇÜMÜNDE VERİ ZARFLAMA ANALİZİ VE MALMQUIST VERİMLİLİK ENDEKSİ İLE TÜRK TEKSTİL SEKTÖRÜNDE BİR UYGULAMA Performans ölçüm teknikleri, bugünkü rekabetçi koşullarda iş dünyası için önemli bir süreci ifade etmektedir. Artış gösteren rekabetten etkilenen firmalar, bu koşullarda ayakta kalabilmek için etkinlikleri hesaplamalı ve optimal verimliliği elde etmeye yönelik doğru kararlar almalıdır. Bu yöntemlerden birisi organizasyonların göreceli etkinliğini belirlemeye yönelik doğrusal programlama tekniklerine dayanan bir sınır yöntemi olan Veri Zarflama Analizidir (VZA).Bu çalışmanın temel amacı, 2001 ekonomik krizi sonrası Türk tekstil sektörünün toplam faktör verimliliğini (TFP), etkinlik değişimini ve teknik değişimini ölçmektir. TFP, Veri Zarflama Analizi tekniğini kullanan çıktı odaklı Malmquist Verimlilik Endeksi vasıtasıyla ölçülmüştür. Analizin güvenilirliğini güçlendirmek amacıyla ölçeğe göre sabit getiri ve ölçeğe göre değişken getiri varsayımı altında iki temel VZA modeli çalışmaya eklenmiştir. Bu noktada İMKB’de işlem gören tekstil sektörüne ait firmaların etkinlik skorları , ölçek etkinlikleri ve etkin olmayan birimler için hedef değerleri araştırılmaya çalışılmıştır. Malmquist endeksi sonuçları ise tekstil sektörü için toplam faktör verimliliğinin 2001 yılını takip eden iki yıl içinde önemli oranlarda azaldığını göstermektedir. GENERAL KNOWLEDGE Name and Surname : Erhan Demirbaş Field : Econometrics Programme : Operations Research Supervisor : Yrd. Doç. Dr. Fatma Urfalıoğlu Degree Awarded and Date : Master - July 2005 Keywords : Efficiency, Data Envelopment Analysis, Malmquist ABSTRACT DATA ENVELOPMENT ANALYSIS AND MALMQUIST PRODUCTIVITY INDEX ON EFFICIENCY MEASUREMENT WITH AN APPLICATION ON TURKISH TEXTILE SECTOR Performance measurement techniques represent an important process for business world in today’s competitive circumstances. The companies which are influenced by increasing competition, must calculat