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Bu araştırmada, Lewatit MP 600 ve Lewatit Sybron Ionac SR 7 reçineleri kullanılarak Cr (VI)’nın sulu çözeltilerden giderilmesi amaçlanmıştır. Bu reçineler, Cr (VI)’nın sudan uzaklaştırılması için ideal bir tutucudur. Cr (VI) giderimi için temas süresi, başlangıç Cr (VI) konsantrasyonu, pH ve reçine miktarı gibi belirli parametrelerin denge çalışmaları üzerine etkisi incelenmiştir. Kısa sürede dengeye ulaşılarak sulu ortamdan hızlı Cr (VI) giderimi, reçinelerin Cr (VI)’yı tutma etkinliğinin yüksek olduğunu göstermiştir. Lewatit MP 600 ve Lewatit SR 7 reçinelerinin, Cr (VI) iyonlarını tutmasından önce ve sonrası için Fourier Dönüşümlü Kızılötesi Spektroskopisi (FT-IR) ile reçinelerin karakterizasyonu ve Taramalı Elektron Mikroskobu (SEM) ile yüzey morfolojisi incelenmiştir. Cr (VI)’nın sulu ortamdan giderim miktarının bulunması ve reçinelerin kapasite tayini için dengede kalan Cr (VI) konsantrasyonuna karşı, reçine tarafından tutulan Cr (VI) grafikleri çizilmiştir. Grafiklere Langmuir, Freundlich, Dubinin-Raduskevich (D-R), Scatchard adsorpsiyon izoterm modelleri uygulanarak reçinelerin kapasite tayini yapılmıştır. Kullanılan reçineler için Langmuir izoterm modelinin Cr (VI) giderimi için daha uygun olduğu sonucuna varılmıştır. Yalancı-ikinci-derece kinetik model, yalancı-birinci-derece kinetik modele göre Cr (VI) giderimi için daha uygun olmuştur. Yapılan deneylerden, bu ticari reçinelerin sulu çözeltilerden Cr (VI) uzaklaştırılması için uygun reçineler olduğu görülür ve arıtma tesislerinde kullanılması önerilir.

Synthesis of Ag, Ni, Cu metallic and Ag/Ni, Ag/Cu bimetallic nanoparticles (NPs) was carried out by using metal nitrate salts as precursors via an easy and simple wet chemical method, and the synthesized NPs were loaded into the cavities of ZSM-5 zeolite framework. L-threonine was used as a capping agent and sodium borohydride as a reducing agent. Characterization of NPs and nanoparticle-modified ZSM-5 catalysts were realized with TEM, XRD, BET, FTIR, TGA, etc. The results obtained revealed that the structure of the zeolites was well preserved after the modification with metal NPs. According to the TEM and BET results, Ag-containing nanocomposite catalysts increased average pore diameter due to the small particle size of Ag NPs such as 2–6 nm well dispersed on the surface and partial blockage of the micropores of zeolite. The catalytic activity of the prepared catalysts was tested in toluene methylation at temperatures of 300 °C, 400 °C, 500 °C and different weight hourly space velocities (WHSV). At low temperatures, the modification of NPs in the ZSM-5 matrix increased toluene methylation and p-xylene selectivity. The highest p-xylene selectivity was found to be about 51% at 400 °C, while toluene conversion at this temperature was 61% using Ag NP-modified ZSM-5 due to the perfect stability NPs on the zeolite structure. The XRD, TGA and coke formation results of used catalysts show the reusability of these catalysts due to their thermal resistance, minimal coke formation and Ag NPs stability onto the zeolite framework.

Today, the importance of materials produced by natural means or by synthesis is increasing in the prevention of increasing water pollution. Sophora Japonica fruit seeds (SJfs) were pyrolyzed at 450 degrees C to produce SJfs-biochar (SJfsB) in this study. Iron nanoparticles were immobilized to the SJfsB structure to form a more active biosorbent matrix. SJfsB and the resulting novel biosorbent (nanomagnetic-Sophora Japonica fruit seeds biochar (nM-SJfsB) were used to remove malachite green (MG) from an aqueous solution. Fourier transform infrared analysis (FTIR) and scanning electron microscopy were used to elucidate the details of the biosorbent properties. The effect on removal was investigated using various parameters. A combined strategy was used to define the adsorption parameters such as adsorbent amount, time, initial dye concentration, pH, and temperature. The maximum adsorption capacity determined by the Langmuir model was 51.020 mg/g for SJfsB-MG and 101.010 mg/g was found for nM-SJfsB-MG. The pseudo second order equation made the equilibrium data suitable. After regeneration, nM-SJfsB can be used for re-adsorption studies and reused for multiple cycles in adsorption and desorption applications without discharging nano-iron particles into aqueous medium.

Batch sorption experiments were performed to investigate the potential of Bauhinia variagata fruit (BVf) and nano-magnetic Bauhinia variagata fruit (nM-BVf) to remove methylene blue (MB) and malachite green (MG). Equilibrium studies have been carried out using various experimental parameters such as the amount of biosorbent, initial solution concentration, contact time, pH, and temperature. The Langmuir, Freundlich, Scatchard, D-R and Temkin adsorption models were applied for the experimental information of MB and MG. The Freundlich model fits better than the Langmuir model. Freundlich model confirmed the magnificent dye sorption ability; 19.3 mg/g for BVf/MB, 21.2 mg/g for nM-BVf/MB, 19.7 mg/g for BVf/MG, and 30.1 mg/g for nM-BVf/MG. The pseudo-second-order kinetic model displayed a more suitable behavior to the experimental result for the removal of MG and MB. Thermodynamic parameters such as changes in Gibbs free energy (Delta G(o)), enthalpy (Delta H-o), and entropy (Delta S-o) were investigated and the fine details in the adsorption system were completed. The conclusion from this study is that the prepared nano biosorbent can be efficient for the removal of cationic dyes from wastewater.

Background: In this work, Cr (VI) adsorption on nano-ZrO2๏TiO2 impregnated orange wood sawdust (Zr๏Ti/OWS) and nano-ZrO2๏TiO2 impregnated peach stone shell (Zr๏Ti/PSS) was investigated by applying different adsorption parameters such as Cr (VI) concentrations, contact time, adsorbent dose, and pH for all adsorbents. Methods: The adsorbents were characterized by SEM and FT-IR. The equilibrium status was achieved after 120 min of contact time and optimum pH value around 2 were determined for Cr (VI) adsorption. Adsorption data in the equilibrium is well-assembled by the Langmuir model during the adsorption process. Results: Langmuir isotherm model showed a maximum adsorption value of OWS: 21.65 mg/g and Zr๏Ti/OWS: 27.25 mg/g. The same isotherm displayed a maximum adsorption value of PSS: 17.64 mg/g, and Zr๏Ti/PSS: 31.15 mg/g. Pseudo-second-order kinetic models (R2=0.99) were found to be the best models for describing the Cr (VI) adsorption reactions. Conclusıon: Thermodynamic parameters such as changes in ΔG°, ΔH°, and ΔS° have been estimated, and the process was found to be spontaneous.

This study involves the production of a novel biosorbent obtained from Cortaderia selloana flower spikes (CSFs). Magnetic C. selloana flower spikes (nM∞CSFs) was applied as an ideal biosorbent for ...

PAN nanofiber-Mat (n-fib@Mat), PAN/ZnO n-fib@Mat, and PAN/ZnO-TiO2 n-fib@Mat were prepared via electrospinning method. Their high adsorption capacities against dissolved Cr (VI) ions make them as super adsorbents for water treatment. The structure of n-fib@Mat was investigated using XRD, FTIR, SEM, and TEM techniques. The effects of selected parameters such as contact time, initial concentration, and n-fib@Mat amount were assessed in a fixed bed reactor. It was found that the adsorption capacities of PAN n-fib@Mat, PAN/ZnO n-fib@Mat, and PAN/ZnO-TiO2 n-fib@Mat were pH-dependent and the optimal pH value was between 2.1 and 2.2. The adsorption was rapid, and the equilibrium was reached within 240 min to remove of Cr (VI) ions for PAN/ZnO-TiO2 n-fib@Mat and 360 min for PAN n-fib@Mat and PAN-ZnO n-fib@Mat. Langmuir isotherms model is preferred for PAN n-fib@Mat, PAN-ZnO n-fib@Mat, and PAN/ZnO-TiO2 n-fib@Mat for Cr (VI) adsorption. The equilibrium adsorption capacities are 153.85 mg/g, 234.52 mg/g, and 333.43 mg/g for PAN n-fib@Mat, PAN/ZnO n-fib@Mat, and PAN/ZnO-TiO2 n-fib@Mat for Cr (VI), respectively. The produced n-fib@Mat showed excellent removal ability for Cr (VI). The adsorption kinetic was obeyed pseudo-second-order reaction rate.

In recent years, the issue on oil pollution in water has drawn continuous attention of researchers. Wastewater containing oil is generated in various industrial technologies, such as petrochemical, leather, textile, food, steel, and metal-finishing industries. Thus, oil sorbents are very commonly used during oil spills cleanup operation for their cost-effectiveness and affordability. In the present work, a novel sandwiched composite electro-spun nanofibrous mat (SCEM) was generated by electro-spinning technique. This sandwiched composite electro-spun mat was fabricated by sandwiching the chitosan-incorporated polyvinyl butyral nanofiber mat between two layers of polyacrylonitrile electro-spun mats. Surface morphology of the generated multilayer nanofibrous mat was observed by the static water contact angle measurement, SEM and FTIR analyses. SCEM was modified by alcoholysis reaction to increase the hydrophobicity and oleophilicity properties by enhancing the surface roughness. After fabrication and modification processes, oil-absorption capacities of single mats, SCEM, and modified mat designated as M-SCEM were investigated and calculated in terms of weight gains. Mats with sandwich structure exhibited excellent absorption capacities up to 100–140 times their own weight for motor oil. The obtained results suggest that these characteristics make spun bond nanofibrous mat a promising oil sorbent material for efficient oily water remediation.

In the present work, Sycamore (Platanus occidentalis) tree seed pod fibers (STSPF) and nano-scale zero valent iron particles (nZVI) immobilized in Sycamore tree seed pod fibers (nZVIʘSTSPF)...

The study explores carbon quantum dots (C-dots) as potential candidates for enhancing the signal sensitivity of an electrochemical sensor devised for biologically important molecule, such as uric acid (UA). The C-dots were evaluated for their electrochemical characteristics in combination with Fe3O4 nanoparticles (Fe3O4 NPs), which were applied as the primary electro-catalytic promoter. The hybrid nanocomposite (C-dots/Fe3O4 HCs) formation was achieved by facilitating the adsorption of C-dots over Fe3O4 NPs using amine-carbonyl interactions. Unlike, one pot method, the proposed strategy enables aggregation-free coverage of Fe3O4 NPs with highly conductive layer of C-dots that can act as conduction centres to support ultra-fast electron transfer kinetics to satisfy the need of high signal sensitivity. The hybrid composite demonstrated remarkable signal improvement when tested against the electrochemical oxidation of UA. The heighten current response and lower over-potential values enabled development of a DC-amperometric (DC-AMP) sensor for UA with a linear working range of 0.01 to 0.145 μM and signal sensitivity measurable up to 6.0 × 10−9 M. The said improvement was manifested as a synergetic outcome of active redox couple (Fe (III/II)), larger surface area of Fe3O4 NPs engulfed with a layer of highly conductive C-dots acting as efficient charge sensitisers.

Polymer nanofibers are valuable materials that are of great importance because they are inexpensive and they display high strength. In this study, nylon-6,6 (N6,6)/graphene oxide (GO) nanofibers were developed and characterized. GO was synthesized from graphene using the known Hummer’s method. GO is obtained by reaction of the graphene with strong oxidants and was characterized using Fourier-transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The characterizations showed that the graphene was suitably oxidized. GO was added to N6,6 to produce N6,6/GO nanofibers at loadings of 0.5, 1.0, 1.5, and 2.0 wt% through the melt mixing method. The batch adsorption model for Cr (VI) adsorption was applied as a function of time, initial Cr (VI) concentration, adsorbent dosage, and pH to examine nanofiber activity. N6,6/GO a exhibited high adsorption capacity for Cr (VI) at pH 2.0. The maximum adsorption capacity for Cr (VI) ion was found to be 47.17 mg/g of N6.6/GO using the related isotherm curves and equations. When the equilibrium data were examined, it was concluded that Langmuir adsorption isotherm was more suitable.

This study evaluates the application of Cr(VI) adsorption from the prepared synthetic solution by black sesame (Sesamum indicum L.) seed pulp (BSSP) and chitosan (Cts)-coated black sesame seed pulp beads (Cts-BSSP). BSSP and Cts-BSSP were used as an adsorbent without any chemical or physical treatment to remove Cr(VI) from an aqueous medium. The results indicated that the Cr(VI) removal was pH-dependent and reached an optimum at pH 2.0. It has been observed that the percentage of adsorption increased from 62% to 95% when the amount of Cts-BSSP increased from 0.0125 g to 0.0250 g. The required adsorbent amount for the maximum removal was 0.05 g and 0.1 g for Cst-BSSP and BSSP, respectively. The contact time for the adsorption was 120 min and 90 min for BSSP and Cst-BSSP, respectively. Scanning electron microscopy and Fourier transform infrared spectroscopy were used to explore the possible adsorption mechanism for Cr(VI). The equilibrium data for the BSSP and Cts-BSSP were used with the Langmuir and Freundlich adsorption isotherm models to assess the adsorption capacity and relevant mechanism. The adsorption capacity of the Cts-BSSP for Cr(VI) is relatively high compared to BSSP. The monolayer maximum adsorption capacities for Cr(VI) ions were 31.44 and 18.32 mg/g for Cts-BSSP and BSSP, respectively.

International Congress on Semiconductor Materials and Devices (ICSMD) -- AUG 17-19, 2017 -- Selcuk Univ, Konya, TURKEY, WOS: 000495858400025, This work investigates the adsorption of chromium ions on chitosan doped with multiwalled carbon nanotubes (Cht-MWCNT). The effects of initial pH, amount of Cht-MWCNT, temperature, contact time, and the initial concentration of Cr (VI) were investigated during the equilibrium and kinetic studies. The equilibrium time was found to be 60 min. Adsorption isotherms of Cr (VI) on Cht-MWCNT was determined and correlated with Langmuir, Freundlich, Scatchard and D-R isotherm equations. The adsorption data showed that adsorption of Cr (VI) was fitted by Langmuir isotherm model and pseudo-second-order kinetics model. Under optimum conditions, maximum adsorption capacity of Cr (VI) determined by Langmuir model were enhanced 26.14 mg/g. Thermodynamic parameters such as Delta G degrees, Delta H degrees, Delta S degrees were calculated and the interaction of Cr (VI) with Cht-MWCNT was found to be endothermic and spontaneous in nature. (C) 2019 Elsevier Ltd. All rights reserved.

In this study, the effect of substituting boron compounds with glycol-based grinding aids to the compressive strength performances of cement was investigated. Monoethylene glycol (MEG) and diethylene glycol (DEG) were used as glycol-based grinding aids, and anhydrous borax and boric acid were used as boron compounds in the tests. CEM I type cement production was carried out with the addition of grinding aid mixtures to Portland clinker and some gypsum in the experiments. All produced cement samples were tested for Blaine fineness, xrf elemental analysis and 2, 7 and 28 days compressive strength tests. Test results of grinding aids of MEG and boron compounds mixture showed no increase in any age of compressive strengths performances related to MEG used itself. However, with the addition of boron compounds to DEG increased grinding aid performance at all ages (2, 7 and 28 days). Possible reasons for this increase could be borate esters formed with DEG and boric acid in a basic medium.

The forms of utility in the wastewater treatment of chitosan-based adsorbents acquired from natural substances have attracted numerous attentions in recent years. The use of chitosan modified adsorbents for removal of the chromium has aroused great interest. When chitosan-based modified adsorbents are considered, they have got large amount of an amino (-NH2) and hydroxyl (-OH) functional groups. Such adsorbents display that they have high activity and therefore they may be extensively utilized in wastewater treatment plants to cast off chromium. In this chapter, the utility outcomes of chitosan-based substances will be explained after applying different parameters to remove Cr (VI) from the aqueous surrounding with the information obtained the use of batch adsorption systems. Application of various chitosan-based adsorbents for Cr (VI) removal application will be demonstrated in a detailed way and they will be discussed within the textual content.

Graphene materials especially single-layer graphene have been identified as a new generation of nanomaterials having various potential applications in material industries. However, the synthesis procedure of single-layer graphene to improve its quality, size and amount has been still under research for commercial applications. The graphene oxide (GO) is synthesised from graphite by Hummer's spontaneous approach which is the most suitable reaction for a large-scale production. For the single-layer graphene, in this work, GO was exfoliated by using a ball milling in an inert atmosphere. Owing to using ball milling as intermediate treatment degreased oxygen functional groups and number of layers, it facilitates to synthesise graphene. Sodium borohydride (NaBH4) and hydroquinone were used as a reductant for the chemical conversion of the exfoliated GO to graphene. The results showed that due to the strong reduction feature, both reducing agents can be applied in the graphene production. As a preferred reductant, hydroquinone can be successfully applied for the synthesis of the single-layer graphene compared to NaBH4. The obtained graphene particles by two different chemicals were characterised by various analytical techniques. The big difference in the structure of GO and graphene was observed in transmission electron microscope analysis.

In this work, polymer nanofibers (PAN/n-OMMT clay) were successfully produced by using an electrospinning process. The PAN/n-OMMT nanofibers were studied as an oil and solvent absorbent material du...

This study investigates the adsorption of Cu(II) and Pb(II) ions onto magnetic-plum stone activated carbon (m-PSAC). Plum stone-activated carbon (PSAC) was produced by chemical activation of plum stone (PS) with phosphoric acid (H3PO4) in N2 inert atmosphere. The effects of activator ratio, activation temperature, and impregnation temperature were examined. m-PSAC was prepared by co-precipitation method which is a combination of PSAC with Fe2 +:Fe3 + salts. The prepared m-PSAC was characterized by scanning electron microscopy (SEM) and Fourier Transform infrared spectrophotometer (FT-IR). Then m-PSAC was used for the removal of Cu(II) and Pb(II) ions from aqueous solutions. The effects of initial pH, the amount of m-PSAC, temperature, contact time, and the initial concentration of Cu(II) and Pb(II) were investigated during the equilibrium and kinetics studies. Adsorption isotherms for the Cu(II) and Pb(II) on m-PSAC was determined and correlated with Langmuir, Freundlich, Scatchard and D-R isotherm equations. The adsorption data showed that adsorption of Cu(II) and Pb(II) was fitted by Langmuir isotherm model and pseudo-second-order kinetics model. Under the optimized conditions, maximum adsorption capacities of Cu(II) and Pb(II) ions determined by Langmuir model were enhanced 48.31 and 80.65 mg/g, respectively. Thermodynamic parameters such as ΔG°, ΔH°, ΔS°, Ea were calculated and the interaction of metals with m-PSAC was found to be exothermic and spontaneous in nature.

In this study biochar was selected as the supporting media for the adsorption of hexavalent chromium (Cr6 +). Biochar is a favored adsorbent due to its high surface area and pore volume. It has created using a pyrolysis process, heating biomass in a low oxygen environment. Two types of agricultural waste, oleaster seed biochar (OSBC) and cherry stone biochar (CSBC) were prepared by using the carbonization method. Structure of biochars was analyzed via the SEM, FTIR analyses and surface area of the biochars was determined by BET analysis. Adsorption performances of biochars were examined by the batch type reactors. The effect of the initial pH Cr6 + concentration, adsorbent amount and contact time on the adsorption process were studied. The maximum amount of removed Cr6 + ions from the solution within 150 min was found to be 84.2% for OSBC, 81.3% within 180 min for CSBC when the initial pH of the solution was maintained at 1.5. Kinetic adsorption of chromium onto biochars was elucidated. The experimental data followed the pseudo-second-order rate kinetics.

A novel chitosan-humic acid-graphene oxide (Cts-HA-GO) composite was produced and tested to remove hexavalent chromium (Cr(VI)) during the adsorption process. The percentage adsorption was 85.28% by using 200 ppm Cr(VI) and 2 g/L composite. Four hours of contact time was enough to remove Cr(VI) from the aquatic medium. The extent of adsorption of Cr(VI) on the surface of Cts-HA-GO composite was examined on the basis of increasing quantity of the composite. The functional group characterization and morphology of composite was characterized using scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. After reaching the equilibrium, the residual concentration of the Cr(VI) solution was measured with an UV-visible spectrophotometer. The results showed that the adsorption behaviour was in accordance with the Langmuir isotherm model, and the maximum adsorption capacity of Cr(VI) determined by using this model was 83.64 mg/g at the pH of 2. A pseudo-second-order model equation has justified the equilibrium between Cr(VI) and the composite for the kinetic studies.

This study was performed to evaluate Cr(VI) removal performance of three anion-exchange resins with different quaternary amine functional groups by varying the conditions of the solution phase. The effects of process variables on the sorption, such as solution pH, temperature, adsorbent dose, phases contact time, and initial Cr(VI), concentration were performed at laboratory condition. The suitability of Freundlich, Langmuir, and Scatchard isotherm models was investigated for Cr(VI)-resin equilibrium. According to the results, calculated maximum ion-exchange capacities were 280.25 mg/g, 147.67 mg/g, and 163.67 mg/g of Cr(VI)/g, for Eichrom 1-X4, Lewatit M+ M800, and Lewatit A8071, respectively. The sorption kinetics and thermodynamic parameters for the equilibrium were studied for all three resins.

WOS: 000473543500005, The study demonstrates an efficient, simple and on-site viable approach for sensitive determination of blood glucose using colorimetric sensing approach. The devised colorimetric sensor works based on cysteine functionalized silver nanoparticles. The as-synthesized Ag NPs were elaborately characterized using advanced analytical techniques such as ultra-violet visible spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, atomic force microscopy and X-ray diffraction. The detection of glucose was carried under ambient air conditions where change in the optical characteristics of Ag NPs and subsequent interaction between glucose and functional moiety (i.e. surface bind cysteine) of Ag NPs was considered as the signal response. This interaction led to direct detection of glucose in the concentration range between 0.01 to 0.17 mu M with limit of detection up to 1 x 10(-4) mu M. It is worthwhile mentioning that success of the assay lies in application of the developed colorimetric sensor in real blood glucose measurements, which also proved its capability for field based analysis. In addition its simple design, low cost, and more reliability signifies the usefulness of colorimetric sensor and it can be extended monitor other biologically important molecules., Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [1059B211600383], This study was funded by The Scientific and Technological Research Council of Turkey (TUBITAK) under 2221-Fellowships for Visiting Scientists and Scientists on Sabbatical Leave, the Grant Number of the project is 1059B211600383.

WOS: 000486132800032, PubMed: 31233985, This study describes the construction of highly-sensitive photo-electrochemical (PEC) immunosensor for the detection of neuron-specific enolase (NSE). The biosensing platform is comprised of photo-active NiWO4 nanostructures, in-situ-grown over a conductive substrate (indium tin oxide) using a low-temperature template-based co-precipitation approach. The discussed approach enables the formation of discrete, yet morphologically-analogous, nanostructures with complete coverage (pinhole-free) of the electrode surface. The in-situ-grown nanostructure possess dense population with sharp saw-blade like morphological features that can support substantial immobilisation of anti-NSE agent. The constructed platform demonstrated excellent photo-catalytic activity towards uric acid (UA) which served as the base for the Electrochemical -mechanism (EC) based PEC inhibition sensing. The detection of NSE, relied on its obstruction in analytical signal observed for the photo-oxidation of UA after binding to the electrode surface via protein-antibody interaction. The constructed PEC immunosensor exhibits signal sensitivity up to 0.12 ng mL(-1) of NSE with excellent signal reproducibility and electrode replicability. Moreover, the constructed platform was successfully used for NSE determination in human serum samples.

International Congress on Semiconductor Materials and Devices (ICSMD) -- AUG 17-19, 2017 -- Selcuk Univ, Konya, TURKEY, WOS: 000495858400014, The effects of phosphoric acid (p) on the polyvinyl alcohol (PVA) as highly hydroxyl-group content polymer have been investigated. Functionalized membranes (p-PVA) have been prepared via sol-gel method with different doped acid ratios. Fourier Transform Infrared (FTIR) spectroscopy is used to confirm the structure of the pure polymer and the synthesized membrane. Water uptake capacity, plane swelling, thickness swelling, proton conductivity by electrochemical impedance spectroscopy (EIS) and thermal stability by thermal gravimetric analysis (TGA) are used to characterize the membranes for their applications in the suitable engineering fields. The results showed that the doped acid has suppressed effects on the hydrophilic properties of the used polymer which leads to decreasing in the water uptake and swelling properties of membranes. Thermally cross-linked 30% p-PVA thin membrane was selected because of its good water uptake capacity (43.78%) and low swelling degree (21.07%). The proton conductivity of all membrane increased with increasing the temperature up to 60 degrees C for 30% p-PVA thin membrane and it attained to 0.07 S cm(-1). The proton conductivity decreased to 0.013 S cm(-1) at the same temperature for 40% p-PVA thin membrane. The thermal stability of doped polymer membranes is significantly higher than pure hydroxylated polymer which indicates the strong bonding between the doped acid and polymer. (C) 2019 Elsevier Ltd. All rights reserved., Selcuk University Scientific Research Projects (BAP)Selcuk University [16201108], We thank Gazi University-Department of Chemical Engineering for providing laboratory devices and Selcuk University Scientific Research Projects (BAP-Grant number 16201108) for the financial support of this work.

Hukukta zamanaşımı, bir hakkın belli bir süre kullanılmaması nedeniyle dava edilebilme niteliğinden mahrum kalmasıdır. Dava veya cezanın düşmesine neden olan zamanaşımı, devletin ceza verme hak ve yetkisinden feragatini ifade eder. Nitekim aradan geçen süreye rağmen dava açılması hakkın kötüye kullanılmasına, yıllar sonra açılacak davalar ise toplumsal düzenin bozulmasına ve adil yargılama hakkına zarar verebilir. Dolayısıyla zamanaşımı, uzun bir süre devam eden fiili bir durumu hukukileştirmektedir.Osmanlı Hukuku ve bu çerçevede hazırlanan Mecelle'de de zamanaşımı bazı hukuki sonuçlara bağlanmıştır. Mecelle'nin 16 maddeden oluşan 14'üncü kitabının 2'inci bölümü zamanaşımı hakkındadır. İlgili hükümler zamanaşımının hak kazandırma fonksiyonuna sahip olmayıp, yalnızca hakkın geri alınmasına engel olduğunu göstermektedir. Uygulamada ise dönem idarecilerini meşgul eden mesele, hazinenin alacağının zamanaşımına tabi olup olmayacağı konusu olmuştur. Mecelle'de zamanaşımı konusunda hukuk birliği sağlandığı fakat geçiş sürecinin nispeten sancılı olduğu anlaşılmaktadır. Dönemim Kadı Sicilleri kayıtları baz alınarak hazırlanan bu çalışma, Mecelle'de zamanaşımı ile ilgili hükümlerin Osmanlı hukuk kurumunun temsilcileri olan kadılar tarafından nasıl yorumlandığı ve sorunların nasıl çözümlediğini göstermesi açısından önem arz etmektedir. Time out in the law is the deprivation of a right for a certain period of time. The time-out, which causes the case or penalty to be reduced, refers to the waiver of the state's right and power to impose penalties. As a matter of fact, despite the intervening period, the right to prosecute can be abused, and the cases to be opened after years can harm the social order and the right to a fair trial. Therefore, the time-out is legalizing a de facto situation that has lasted for a long time. The Ottoman Law and the Mecelle, which were prepared within this framework, have been subject to some legal consequences.The second part of Mecelle's 14th book, which consists of 16 items, is about timeout. The relevant provisions show that the timeout does not have a qualifying function but only prevents the retraction of the right.In practice, the issue that occupies the administrators of the period has been the subject of whether or not the treasury will be subject to time-out.It is understood that the legal unity is achieved in Mecelle, but the transition period is relatively painful. This study, which was prepared on the basis of the records of the Kadı Registers of the period, is important in terms of showing how the time-related provisions in Mecelle are interpreted by the women who are the representatives of the Ottoman legal institution and how the problems are resolved. 136

WOS: 000502271700099, PubMed: 31726731, We report a novel, simple, efficient, and green protocol for biogenic synthesis of silver nanoparticles (AgNPs) in aqueous solution using clove (Syzygium aromaticum) extract as a reducing and protecting agent. Ultraviolet-visible (UV-Vis) spectroscopy was employed to monitor the localized surface plasmon resonance (LSPR) band of clove extract-derived AgNPs prepared under various conditions. Fourier-transform infrared (FTIR) spectroscopy analysis provided information about the surface interaction of the clove extract with the AgNPs. Ultrahigh-resolution transmission electron microscopy (UHRTEM) results confirmed the formation of spherical, uniformly distributed clove extract-capped AgNPs with sizes in the range of 2-20 nm (average size: 14.4 +/- 2 nm). Powder X-ray diffractometry analysis (PXRD) illustrated the formation of pure crystalline AgNPs. These AgNPs were tested as a colorimetric sensor to detect trace amounts of vinclozolin (VIN) by UV-Vis spectroscopy for the first time. The AgNP-based sensor demonstrated very sensitive and selective colorimetric detection of VIN, in the range of 2-16 mu M (R-2 = 0.997). The developed sensor was green, simple, sensitive, selective, economical, and novel, and could detect trace amounts of VIN with limit of detection (LOD) = 21 nM. Importantly, the sensor was successfully employed for the determination of VIN in real water samples collected from various areas in Turkey., TUBITAKTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [21514107-115.02-188888]; King Saud University, Riyadh, Saudi ArabiaDeanship of Scientific Research at King Saud University [RSP-2019/79], We are thankful to TUBITAK for Fellowship provision to the first author via BIDEB 2216 Research Fellowship Program, Ref: 21514107-115.02-188888. This work was also funded through Researchers Supporting Project number (RSP-2019/79) at King Saud University, Riyadh, Saudi Arabia.

Copper ion (Cu 2 + ) removal from aqueous solutions was performed with two different chelating resins (bis-picolylamine, iminodiacetate). In order to compare the results obtained from the chelating resins, strong acid cation exchangers were used with sulfonic acid functionally. The effects of the following parameters such as the amount of resin, the duration, pH levels and concentration were noted for the ion-exchange. The Langmuir, Freundlich, D-R and Scatchard isotherm models were used to evaluate the data. The Langmuir isotherm model was found to be the best model. The chelating resins which retained some of their functional groups showed good properties for the removal of Cu 2 + from aqueous solutions. The sorption capacity of the resins increased with the rising Cu 2 + concentration in the aqueous medium. FT-IR analysis results show clearly that the ion-exchange and chelating took place as mechanisms which rule during the sorption of Cu 2 + from aqueous phase.

Arsenic (V) adsorption on manganese oxide coated rice wastes was investigated in this study. The modified adsorbents were characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, and pH measurements to determine the point of zero charge. Batch adsorption equilibrium experiments were conducted to study the effects of pH, contact time, and initial concentration on arsenic removal efficiency. The adsorption capacity of rice waste was significantly improved after modification with permanganate. The Langmuir isotherm model fitted the equilibrium data better than the Freundlich model which confirms surface homogeneity of the adsorbent. Maxima adsorption capacities are determined as 10 and 12 mg/g at pH 3 for manganese oxide coated rice husk and straw, respectively. The adsorption energy indicates that the adsorption process may be dominated by chemisorption. Pseudo-second-order rate equation described the kinetics sorption of arsenic with good correlation coefficients, bet...

WOS: 000444858200001, Milling aids have been predominantly developed to increase the performance or grinding capacity of cement products, and alcohol amines have been used as grinding aids in cement grinding processes for many years. Moreover, the setting point of cement produced with grinding aids is most often changed. In this study, the effects of alkanolamines and boron compounds in different mixing amounts as grinding aids on the set point of cement were researched. Triethanolamine (TEA) and triisopropanolamine (TIPA) were used as alkanolamines and boric acid (BA) and anhydrous borax (AHB) as the boron compounds. It is evident that BA with TEA had a small effect on the cement setting point where the former decreased the retarding effect of the latter, but BA had no effect with TIPA. AHB decreased the retarding effect of TEA but had no effect with TIPA on setting times. When the boron compounds were added to TEA, they accelerated the initial setting points of cement by 15 to 20 minutes and the final setting points by 25 to 30 minutes according to the amount of TEA used., SYCS Construction and Cement Company, This study was supported by SYCS Construction and Cement Company through funds to Murat Calli (Ph.D. Student in the Department of Chemical Engineering in Selcuk University and Quality Manager in SYCS Construction and Cement Company).

The adsorption of Cr(VI) on rye husk (RH) was studied at varying Cr(VI) concentrations, adsorbent dose, contact time, and pH. Maximum Cr(VI) was sequestered from the solution within 140 min and the maximum removal of 5.0 mM Cr(VI) was about 68% at pH of 3.0 for 0.5 g RH. The removal of Cr(VI) was maximum (80.0%) when the initial pH of the solution was kept at 3.0. The Cr(VI) adsorption capacity of RH samples was calculated as 0.435 mmol/g at pH 3.0 from Langmuir isotherm. The adsorption kinetics data were evaluated with first-order reversible and pseudo-second-order kinetics models.

Polyacrylonitrile/titanium dioxide nanofiber (PAN/T-nF) membrane was prepared with TiO2 nanoparticles which dispersed into polyacrylonitrile (PAN) matrix with ultrasonic probe in ultrasonic bath. The amount of TiO2 loaded in the membrane was 1 and 3 wt% to explore the activity of membranes in the adsorption process. PAN/T-nF membrane was prepared by electrospinning technique. The potential of the prepared PAN/T-nF membrane was investigated for the removal of Cr(VI) from aqueous solutions. The adsorption equilibrium was investigated in the batch process. The adsorption process displayed pH dependence and the maximum Cr(VI) adsorption took place at pH 2. The equilibrium was attained at a contact time of 180 min and Langmuir adsorption model was suitable for the adsorption isotherms. Maximum adsorption capacities 245.3 and 280.4 mg Cr(VI)/g were calculated for 1 and 3% PAN/T-nF membrane, respectively. The adsorption of Cr(VI) on PAN/T-nF was related to the mechanism of surface complexation, coordinat...

WOS: 000360793100010, PubMed: 26322758, Because of the recognition that arsenic (As) at low concentrations in drinking water causes severe health effects, the technologies of As removal have become increasingly important. In this study, a simplified and effective method was used to immobilize iron oxyhydroxide onto a pretreated naturally occurring rice straw (RS). The modified RS adsorbent was characterized, using scanning electron microscope, Fourier transform infrared spectroscopy, thermogravimetric analyzer, and surface area analyzer. Experimental batch data of As(V) adsorption were modeled by the isotherms and kinetics models. Although all isotherms, the Langmuir model fitted the equilibrium data better than Freundlich and Dubinin-Radushkevich models and confirmed the surface homogeneity of adsorbent. The iron oxyhydroxide-coated rice straw (IOC-RS) was found to be effective for the removal of As(V) with 98.5% sorption efficiency at a concentration of, German Federal Ministry for Economic Cooperation and Development (BMZ); German Academic Exchange Service (DAAD)Deutscher Akademischer Austausch Dienst (DAAD), This investigation was performed at the Guest Chair within the project 'Exceed - Excellence Center for Development Cooperation - Sustainable Water Management in Developing Countries' at the Technische Universitaet Braunschweig, Prof. Pehlivan being the visiting professor, and Ms Tran and Dr Ouedraogo being the international exchange staff members. The Exceed Project is granted by the German Federal Ministry for Economic Cooperation and Development (BMZ) and German Academic Exchange Service (DAAD), and their financial support we gratefully acknowledge.

A novel intumescent coating technology for metallic surfaces was developed using functionalized clays, which were intercalated and exfoliated into nanodimensions. The nanoclays were formulated in epoxy resins and blended with appropriate additives to design intumescent coatings for metallic surfaces. With the high dispersion of nanoclay the flame retardancy is improved. The extent and the homogeneity of the exfoliation and dispersion of the clay particles were assessed employing small-amplitude oscillatory shear. The performance and properties of the coatings were evaluated by means of fire resistance testing, thermo-gravimetric analysis and mechanical properties. The incorporation of the nanoclays significantly increased the elasticity and the viscosity of the intumescent formulations and improved the fire resistance of the epoxy coatings. It is observed that significant gains in flame retarding properties could be achieved when the clay platelets could be adequately exfoliated and dispersed.