87 research outputs found

    Adsorption Of Methylene Blue from Aqueous Solution with Sulfuric Acid Activated Corn Cobs: Equilibrium, Kinetics, and Thermodynamics Assessment

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    Three adsorbents with different characteristics were produced in this study by activation of sulfuric acid with different concentrations, from corn Zea mays L. cobs, which is an agricultural waste by-product resulting from harvesting. After characterization by the parameters such as Boehm titration, determination of pH-pHpzc, and methylene blue – iodine number, and IR analysis, their methylene blue adsorption potentials from aqueous medium were investigated based on equilibrium, kinetics, and thermodynamics evaluations. This study aims to examine the effects of relatively dilute and concentrated acids on the activation process and to gain an economic value to waste materials through the production of a new adsorbent. It was observed that the initial solution pH did not have a significant effect on the adsorption efficiency. The adsorption process reached the equilibrium at the end of the first 120 minutes, and the kinetic data fit the pseudo-second-order kinetic model. Langmuir adsorption capacity 295.5 mg/g of the adsorbent produced by activating with 50% sulfuric acid was found higher than those produced with 75% and 98% acids. An increase in ambient temperature effected the adsorption positively. As a result, in this study, very low-cost adsorbents were produced from the waste by-product corn cobs, and a new approach was proposed for cleaning wastewater containing dyestuffs

    Post-intervention Status in Patients With Refractory Myasthenia Gravis Treated With Eculizumab During REGAIN and Its Open-Label Extension

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    OBJECTIVE: To evaluate whether eculizumab helps patients with anti-acetylcholine receptor-positive (AChR+) refractory generalized myasthenia gravis (gMG) achieve the Myasthenia Gravis Foundation of America (MGFA) post-intervention status of minimal manifestations (MM), we assessed patients' status throughout REGAIN (Safety and Efficacy of Eculizumab in AChR+ Refractory Generalized Myasthenia Gravis) and its open-label extension. METHODS: Patients who completed the REGAIN randomized controlled trial and continued into the open-label extension were included in this tertiary endpoint analysis. Patients were assessed for the MGFA post-intervention status of improved, unchanged, worse, MM, and pharmacologic remission at defined time points during REGAIN and through week 130 of the open-label study. RESULTS: A total of 117 patients completed REGAIN and continued into the open-label study (eculizumab/eculizumab: 56; placebo/eculizumab: 61). At week 26 of REGAIN, more eculizumab-treated patients than placebo-treated patients achieved a status of improved (60.7% vs 41.7%) or MM (25.0% vs 13.3%; common OR: 2.3; 95% CI: 1.1-4.5). After 130 weeks of eculizumab treatment, 88.0% of patients achieved improved status and 57.3% of patients achieved MM status. The safety profile of eculizumab was consistent with its known profile and no new safety signals were detected. CONCLUSION: Eculizumab led to rapid and sustained achievement of MM in patients with AChR+ refractory gMG. These findings support the use of eculizumab in this previously difficult-to-treat patient population. CLINICALTRIALSGOV IDENTIFIER: REGAIN, NCT01997229; REGAIN open-label extension, NCT02301624. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that, after 26 weeks of eculizumab treatment, 25.0% of adults with AChR+ refractory gMG achieved MM, compared with 13.3% who received placebo

    Minimal Symptom Expression' in Patients With Acetylcholine Receptor Antibody-Positive Refractory Generalized Myasthenia Gravis Treated With Eculizumab

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    The efficacy and tolerability of eculizumab were assessed in REGAIN, a 26-week, phase 3, randomized, double-blind, placebo-controlled study in anti-acetylcholine receptor antibody-positive (AChR+) refractory generalized myasthenia gravis (gMG), and its open-label extension

    Application of carrier element free coprecipitation (cefc) method for determination of co(II), cu(II) and ni(II) Ions in food and water samples

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    OZDES, Duygu/0000-0002-8692-2676WOS: 000322040900006PubMed: 23878931A simple and highly sensitive separation and preconcentration procedure, which has minimal impact on the environment, has been developed. The procedure is based on the carrier element free coprecipitation (CEFC) of Co(II), Cu(II), and Ni(II) ions by using 2-{4-[2-(1H-indol-3-yl)ethyl]-3-(4-methylbenzyl)-5-oxo-4,5-dihydro-1H-1,2,4-triazol-1-yl}-N'-(pyridin-2-yl methylidene)acetohydrazide (IMOTPA), as an organic coprecipitant. The levels of analyte ions were determined by flame atomic absorption spectrometry (FAAS). The detection limits for Co(II), Cu(II) and Ni(II) ions were found to be 0.40, 0.16 and 0.17 mu g L-1, respectively, and the relative standard deviations for the analyte ions were lower than 3.0%. Spike tests and certified reference material analyses were performed to validate the method. The method was successfully applied for the determination of Co(II), Cu(II) and Ni(II) ions levels in sea and stream water as liquid samples and red pepper, black pepper, and peppermint as solid samples.Unit of the Scientific Research Projects of Karadeniz Technical UniversityKaradeniz Teknik University [1156]Authors wish to thank the Unit of the Scientific Research Projects of Karadeniz Technical University (Project No: 1156) for the financial support

    Assessment of Heavy Metal Contents of Mulberry Samples (Fruit, Leaf, Soil) Grown in Gumushane Province

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    Baltaci, Cemalettin/0000-0002-4336-4002WOS: 000458550500013The present study aims to identify the heavy metal contents of white mulberry (Morus albaL.) and black mulberry (Morus nigraL.) that are grown in the city center of Gumushane province and its neighboring counties. Heavy metal analyzes were performed in the fruits, leaves and soils of the plants. the control samples, on the other hand, were collected from the mulberry trees located 3km away from the highway where the vehicle traffic and industrial activities are at their lowest. Sample collection was performed twice ayear, namely during the ripening period and fully ripening period of the fruits.The analyses of the heavy metals were performed by using inductively coupled plasma-mass spectrophotometry (ICP-MS). the obtained results were compared with the acceptable limits of heavy metal for humans as established by the World Health Organization (WHO), Turkish Food Codex (TFC) and the literature and an opinion was submitted as to whether they present any risk in terms of human health. When the available data is evaluated, the mulberries grown in Gumushane province, were found to have presented ahealth risk in terms of Pb, Cd, Ni, Cu, Zn, Mn and Co metals.Research Council of the Gumushane University [:16, B0110.02.01]The authors wish to thank the Research Council of the Gumushane University (Project No:16.B0110.02.01) for the financial support of this study

    Methylene blue adsorption onto drinking water treatment plant’s sludge and modeling by artificial neural network

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    Bu çalışmada içme suyu arıtma tesislerinde arıtım aşamaları sonucu oluşan İçme Suyu Arıtma Tesisi Atık Çamurunun (İSATAÇ), atık sularda organik kökenli bir kirletici (boyar madde) olan Metilen Mavisinin uzaklaştırılmasında adsorban olarak kullanılabilirliği araştırılmıştır. Adsorpsiyon çalışmalarında kullanılan İSATAÇ fiziksel ya da kimyasal ön işleme tabi tutulmamıştır. Öncelikle İSATAÇ’ın nem, yoğunluk, uçucu madde, sabit karbon, kül tayini yanı sıra elementel, SEM, FT-IR, XRD, XRF ve TGA/DTA analiz gibi çeşitli analitik işlemlerle karakterize edilmiştir. Sonrasında adsorpsiyon deneyleri kesikli sistemle gerçekleştirilmiş ve İSATAÇ’ın sulu çözeltiden bu kirletici türü uzaklaştırma potansiyeli denge, kinetik ve termodinamik parametreler açısından incelenmiştir. Metilen mavisinin uzaklaştırılmasında Langmuir izoterm modelinden elde edilen maksimum adsorplama kapasitesi 62,50 mg g-1 olarak tespit edilmiştir. Bazı deneysel parametrelerin İSATAÇ üzerinde Metilen Mavisi adsorpsiyonuna etkileri göz önüne alınarak Yapay Sinir Ağı (YSA) modeli geliştirilmiş ve İSATAÇ’ın atık sulardan organik kirleticilerin uzaklaştırılmasında kullanılabileceği sonucuna varılmıştır.In this work, it was investigated usability of Drinking Water Treatment Sludge (DWTS), obtained as end product at the end of treatment stages, as an adsorbent for removal of Methylene Blue, the organic pollutant (dyestuff), present in wastewaters. DWTS used for the adsorption experiments were not subjected to physical or chemical pre-treatment. Firstly, DWTS was characterized employing various analytical procedures including determination of moisture, density, volatiles, fixed carbon, ash, as well as elemental, SEM, FT-IR, XRD, XRF and TGA/DTA analysis. Then, adsorption experiments were carried out in a batch system and DWTS’s removal potential of the pollutant specie from aqueous solution was investigated in terms of equilibrium, kinetics and thermodynamics. DWTS’s maximum adsorption capacity obtained from Langmuir model for Methylene Blue was 62.50 mg g-1. Artificial Neural Network (ANN) model was developed considering the effects of certain experimental parameters for adsorption of Methylene Blue on DWTS and it was concluded that DWTS can be used to remove organic pollutants from wastewaters

    Coprecipitation of palladium(II) with 1,5-diphenylcarbazite-copper(II) and determination by flame atomic absorption spectrometry

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    In this study Cu2+/1,5-diphenylcarbazite precipitate was used for coprecipitation of palladium(II) prior to its flame atomic absorption spectrometric (FAAS) determination. The recovery values of analyte ion were higher than 95%. The parameters including pH, sample volume, centrifuge time, amounts of copper(II) and 1,5-diphenylcarbazite were optimized for the quantitative recoveries of the analyte. The relative standard deviation of Pd(II) was found to be 6.3%. The limit of detection was calculated as 0.40 mu g L-1. The validation of the procedure was checked by the analysis of CRM-SA-C (standard material). The presented coprecipitation procedure was successfully applied to anodic slime and gold ore samples for determination of analyte ion. (C) 2010 Elsevier B.V. All rights reserved

    Evaluation of Pomological and Morphological Characteristics and Chemical Compositions of Local Pear Varieties (Pyrus communis L.) Grown in Gumushane, Turkey

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    Karabulut, Besim/0000-0003-0198-8447WOS: 000432206200011The aim of the present research was to investigate the fruit quality of twenty different local pear varieties (Pyrus communis L.), namely Ahlat, Ankara, Arpa, BA +/- ldA +/- rcA +/- n, Cermai, Cinci, Gelin Bogan, HacA +/- Hamza, HahA +/- r, Kabak, KA +/- zA +/- l, Kokulu, Mehrani, Menendi, Sulu, Aalgam, Tokat SultanA +/-, TurAYu, Yaz, and Yaz Meyrigi, grown in Gumushane province in terms of pomological and morphological characteristics and chemical compositions. the fruit mass, fruit width and length, fruit stem thickness and length, fruit kernel width and length, hardness of pulp, number of seeds, leaf width and length, leaf stem length and thickness, and water soluble dry matter (WSDM) of the pear fruits have been determined as pomological and morphological characteristics. on the other hand, the chemical compositions of the pear varieties have been evaluated in terms of protein, ash, sucrose, fructose, glucose, total sugar, titratable acidity, moisture, and mineral element levels. Both pomological and morphological results demonstrated that the local pear varieties are important in terms of rehabilitation studies and detailed selection studies on these local varieties should be performed. the chemical analyses result of the pear varieties revealed that there is no component that may be harmful to human health when consumed, and also these varieties contains the necessary amount of mineral elements.Research Council of the Gumushane University [16.B0123.02.01]The authors wish to thank the Research Council of the Gumushane University (Project No: 16.B0123.02.01) for the financial support of this study

    Acetohydrazide Derivative for Selective Separation and Preconcentration of Cu(II) Ions by Coprecipitation Method Without Using a Carrier Element

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    12th National Spectroscopy Congress -- MAY 18-22, 2011 -- Antalya, TURKEYSoylak, Mustafa/0000-0002-1017-0244; OZDES, Duygu/0000-0002-8692-2676WOS: 000303588400004A simple and rapid procedure based on the combination of carrier element free coprecipitation (CEFC) and flame atomic absorption spectrometric (FAAS) determinations has been developed for selective separation and preconcentration of Cu(II) ions in some environmental solid (Turkish and import coffee) and liquid (sea and stream waters) samples. In this method, acetohydrazide derivative was used as an organic coprecipitant without adding any carrier element for coprecipitation of Cu(II) ions. The preconcentration factor was found to be 50, the limit of detection (LOD) was 0.31 mg L-1, while the relative standard deviation (RSD) was found to be 1.6% for Cu(II) ions
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