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Now showing 1 - 4 of 4
  • Review
    Citation - WoS: 22
    Citation - Scopus: 36
    Principles of Reverse Electrodialysis and Development of Integrated-Based System for Power Generation and Water Treatment: a Review
    (Walter de Gruyter Gmbh, 2022) Othman, Nur Hidayati; Kabay, Nalan; Guler, Enver
    Reverse electrodialysis (RED) is among the evolving membrane-based processes available for energy harvesting by mixing water with different salinities. The chemical potential difference causes the movement of cations and anions in opposite directions that can then be transformed into the electrical current at the electrodes by redox reactions. Although several works have shown the possibilities of achieving high power densities through the RED system, the transformation to the industrial-scale stacks remains a challenge particularly in understanding the correlation between ion-exchange membranes (IEMs) and the operating conditions. This work provides an overview of the RED system including its development and modifications of IEM utilized in the RED system. The effects of modified membranes particularly on the psychochemical properties of the membranes and the effects of numerous operating variables are discussed. The prospects of combining the RED system with other technologies such as reverse osmosis, electrodialysis, membrane distillation, heat engine, microbial fuel cell), and flow battery have been summarized based on open-loop and closed-loop configurations. This review attempts to explain the development and prospect of RED technology for salinity gradient power production and further elucidate the integrated RED system as a promising way to harvest energy while reducing the impact of liquid waste disposal on the environment.
  • Article
    Citation - WoS: 21
    Silent Enhancement of Sers Signa Without Increasing Hot Spot Intensities
    (Walter de Gruyter Gmbh, 2018) Postaci, Selen; Yildiz, Bilge Can; Bek, Alpan; Tasgin, Mehmet Emre
    Plasmonic nanostructures enhance nonlinear response, such as surface enhanced Raman scattering (SERS), by localizing the incident field into hot spots. The localized hot spot field can be enhanced even further when linear Fano resonances take place in a double resonance scheme. However, hot spot enhancement is limited with the modification of the vibrational modes, the breakdown of the molecule, and the tunneling regime. Here, we present a method which can circumvent these limitations. Our analytical model and solutions of 3D Maxwell equations show that: enhancement due to the localized field can be multiplied by a factor of 10(2)-10(3). Moreover, this can be performed without increasing the hot spot intensity which also avoids the modification of the Raman modes. Unlike linear Fano resonances, here, we create a path interference in the nonlinear response. We demonstrate on a single equation that enhancement takes place due to cancellation of the contributing terms in the denominator of the SERS response. Our method can be implemented on an atomic force microscope tip, decorated (or "contaminated") with appropriate quantum emitters.
  • Article
    Romatizmal Mitral Kapak Hastalığında Yeni Yolak: Sitokrom P450 ve Glutatyon S Transferaz İzozim Ekspresyonu
    (Walter de Gruyter Gmbh, 2020) Şimşek, Erdal; Şimşek, Gülçin; Sayol, Mehmet Fazıl Tolga; Kaygın, Pınar; Oğuztüzün, Serpil; Düzgün, Ali Cemal; Kaplan, Sadi
    Amaç: Romatizmal mitral kapak hastalığı ve iskemik mitral kapak yetmezlikli hastalarda Sitokrom P450 (CYP)1A1, glutatyon S-transferaz pi (GSTP1) ve omega (GSTO1) izozimleri karşılaştırılarak, romatizmal mitral kapak hastalığı ile oksidatif stres arasındaki ilişki araştırıldı. Gereç ve Yöntem: Kontrol grubunu, iskemik mitral kapak yetmezliği sebebiyle ameliyat edilen (group I, n:14), çalışma grubunu ise romatizmal mitral kapak hastalığı nedeni ile ameliyat edilen (group II, n:29) hastalar oluşturmuştur. Mitral kapak materyalleri hematoksilen ve eozinle boyandı. CYP1A1, GSTP1, ve GSTO1 immünohistokimyasal belirteçler ile çalışıldı. Bulgular: Çalışma grubunda %20.7 GSTP1 isozim protein ekspresyonu gözlendi; fakat kontrol grubunda ekspresyon izlenmedi. Bu bulgu GSTP1 izozim açısından istatistiksel olarak önemli bulundu. Çalışma ve kontrol grupları arasında GSTO1 ve CYP1A1 protein ekspresyonları açısından istatistiksel anlamlı farklılık görülmedi. Sonuç: Bu çalışmada GSTP1 izozimi romatizmal mitral kapak hastalığı ile ilişkili olabileceği görüldü. Romatizmal mitral kapak hastalığı olan hastalarda oksidatif stresi önleyen strateji, hastalığın ilerleyişini engellemek için çok değerli bir seçim olabilir.
  • Conference Object
    Citation - WoS: 33
    Citation - Scopus: 35
    Enhancement of Mechanical, Thermal and Water Uptake Performance of Tpu/Jute Fiber Green Composites Via Chemical Treatments on Fiber Surface
    (Walter de Gruyter Gmbh, 2020) Salem, Tuffaha Fathe; Tirkes, Seha; Akar, Alinda Oyku; Tayfun, Umit
    Chopped jute fiber (JF) surfaces were modified using alkaline, silane and eco-grade epoxy resin. Surface characteristics of jute fibers were confirmed by FTIR and EDX analyses. JF filled polyurethane elastomer (TPU) composites were prepared via extrusion process. The effect of surface modifications of JF on mechanical, thermo-mechanical, melt-flow, water uptake and morphological properties of TPU-based eco-composites were investigated by tensile and hardness tests, dynamic mechanical analysis (DMA), melt flow index (MFI) test, water absorption measurements and scanning electron microscopy (SEM) techniques, respectively. Mechanical test results showed that silane and epoxy treated JF additions led to increase in tensile strength, modulus and hardness of TPU. Glass transition temperature (T-g) of TPU rose up to higher values after JF inclusions regardless of treatment type. Si-JF filled TPU exhibited the lowest water absorption among composites. Surface treated JFs displayed homogeneous dispersion into TPU and their surface were covered by TPU according to SEM micro-photographs.