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Article Citation - WoS: 10Citation - Scopus: 13Is There an Informal Employment Wage Penalty in Egypt? Evidence From Quantile Regression on Panel Data(Physica-verlag Gmbh & Co, 2020) Tansel, Aysit; Keskin, Halil Ibrahim; Ozdemir, Zeynel AbidinThis is the first study that uses panel data to assess the magnitude of the informal sector wage gap in Egypt. We consider the private sector male wage earners in Egypt and examine their wage distribution during 1998-2012 using the Egyptian Labor Market Panel Survey. We estimate Mincer wage equations both at the mean and at different quantiles of the wage distribution taking into account observable and unobservable characteristics with a fixed effect model. We also consider the possibility of nonlinearity in covariate effects and estimate a variant of matching models. We find a persistent informal wage penalty in the face of extensive sensitivity checks. It is smaller when unobserved heterogeneity is taken into account, and unlike many previous studies, there are very few differences across the conditional wage distribution. We also examine the informal wage penalty over time and in different subgroups according to age and education. The informal wage penalty has increased recently over time and is larger for the higher educated and the young.Article Citation - WoS: 1Citation - Scopus: 1Chemical Composition Optimization and Isothermal Transformation of Δ-Transformation Plasticity Steel for the Third-Generation Advanced High-Strength Steel Grade(Wiley-v C H verlag Gmbh, 2024) Okur, Onur; Davut, Kemal; Palumbo, Gianfranco; Nalcaci, Burak; Guglielmi, Pasquale; Yalcin, Mustafa Alp; Erdogan, MehmetA new low-manganese transformation-induced plasticity steel is designed with optimized nickel content to achieve superior strength and ductility while minimizing the use of expensive nickel. The steel is optimized using JMatPro software, then cast, and hot rolled. To assess the effect of intercritical annealing on austenite (martensite at room temperature) volume fraction and carbon content, hot-rolled steel samples quenched from different annealing temperatures (680-1100 degrees C) are used. Additionally, hot-rolled steel coupons are intercritically annealed at about 50% austenite formation temperature (740 degrees C) and then subjected to isothermal treatments at 300-425 degrees C for varying times (10-90 min). After optimizing these treatments to maximize retained austenite (RA), tensile specimens are heat-treated first at 740 degrees C and then isothermally at 325 degrees C. Thermodynamic calculations suggest that aluminum combined with silicon may lead to the delta ferrite formation, and even minimal nickel content can stabilize a considerable amount of austenite. In the experimental studies, it is shown that lower-temperature bainitic holding enhances austenite stability by enriching the carbon content. Optimized two-stage heat treatments yield up to 25.8% RA, with a tensile strength of 867.2 MPa and elongation of 40.6%, achieving a strength-elongation product of 35.2 GPax%, surpassing the third-generation advanced high-strength steel grades minimum requirement of 30 GPax%.Article Citation - WoS: 53Citation - Scopus: 54Forward and Reverse Bias Current-Voltage Characteristics of Au/N-si Schottky Barrier Diodes With and Without Sno2 Insulator Layer(Elsevier, 2011) Gokcen, M.; Altindal, S.; Karaman, M.; Aydemir, U.; Altndal, S.The effects of interfacial insulator layer, interface states (N-ss) and series resistance (R-s) on the electrical characteristics of Au/n-Si structures have been investigated using forward and reverse bias current-voltage (I-V) characteristics at room temperature. Therefore, Au/n-Si Schottky barrier diodes (SBDs) were fabricated as SBDs with and without insulator SnO2 layer to explain the effect of insulator layer on main electrical parameters. The values of ideality factor (n), R-s and barrier height (Phi(Bo)) were calculated from ln(I) vs. V plots and Cheung methods. The energy density distribution profile of the interface states was obtained from the forward bias I-V data by taking bias dependence of ideality factor, effective barrier height (Phi(e)) and R-s into account for MS and MIS SBDs. It was found that N-ss values increase from at about mid-gap energy of Si to bottom of conductance band edge of both SBDs and the MIS SBD's N-ss values are 5-10 times lower than those of MS SBD's. An apparent exponential increase from the mid-gap towards the bottom of conductance band is observed for both SBDs' (MS and MIS) interface states obtained without taking R-s into account. (C) 2011 Elsevier B.V. All rights reserved.Article Citation - WoS: 5Citation - Scopus: 7G-Csf Treatment of Healthy Pediatric Donors Affects Their Hematopoietic Microenvironment Through Changes in Bone Marrow Plasma Cytokines and Stromal Cells(Academic Press Ltd- Elsevier Science Ltd, 2021) Aerts-Kaya, Fatima; Kilic, Emine; Kose, Sevil; Aydin, Gozde; Cagnan, Ilgin; Kuskonmaz, Baris; Uckan-Cetinkaya, DuyguAlthough G-CSF mobilized peripheral blood stem cell (PBSC) transplantation is commonly used in adults, bone marrow (BM) is still the preferred stem cell source in pediatric stem cell transplantation. Despite the fact that G-CSF is increasingly being used to enhance the hematopoietic stem/progenitor cell (HSPC) yield in BM transplantation (G-BM), the direct effects of G-CSF on the pediatric BM microenvironment have never been investigated. The BM hematopoietic niche provides the physical space where the HSPCs reside. This BM niche regulates HSPC quiescence and proliferation through direct interactions with other niche cells, including Mesenchymal Stromal Cells (MSCs). These cells have been shown to secrete a wide range of hematopoietic cytokines (CKs) and growth factors (GFs) involved in differentiation, retention and homing of hematopoietic cells. Here, we assessed changes in the BM microenvironment by measuring levels of 48 different CKs and GFs in G-BM and control BM (C-BM) plasma from pediatric donors. In addition, the effect of G-CSF on cell numbers and characteristics of HSPCs and MSCs was assessed. IL-16, SCGF-b, MIP-1b (all >1000 pg/mL) and RANTES (>10.000 pg/mL) were highly expressed in healthy donor pediatric BM plasma. Levels of IL-3, IL-18, GROa, MCP-3 (p<0.05) were increased in G-BM, whereas levels of RANTES (p<0.001) decreased after G-CSF treatment. We found a negative correlation with increasing age for IL2-Ra and LIF (p<0.05). In addition, a concomitant increase in the number of both hematopoietic and fibroblast colony forming units was observed, indicating that G-CSF affects both HSPC and MSC numbers. In conclusion, G-CSF treatment of healthy pediatric donors affects the hematopoietic BM microenvironment by expansion of HSPC and MSC numbers and modifying local CK and GF levels.Article Citation - WoS: 6Citation - Scopus: 6Gold and Ytterbium Interfacing Effects on the Properties of the Cdse/Yb Nanosandwiched Structures(Elsevier Science Bv, 2018) Alharbi, S. R.; Qasrawi, A. F.Owing to the performance of the CdSe as an optoelectronic material used for the production of quantum dots, photosensors and wave traps we here, in this article, report the enhancements in structural and electrical properties that arises from the nanosandwiching of a 40 nm thick Yb film between two films of CdSe (CYbC-40). The CdSe films which were deposited onto glass, Yb and Au substrates are characterized by X-ray diffraction, temperature dependent electrical conductivity and impedance spectroscopy measurements in the frequency range of 10-1800 MHz. The analysis of the XRD patterns have shown that the glass/CdSe/Yb/CdSe films exhibit larger grain size and lower strain, defect density and lower stacking faults compared to the not sandwiched CdSe. In addition, it was observed that the Yb shifts the donor states of the n-type CdSe from 0.44 to 0.29 eV leading to a modification in the built in voltage of the material. On the other hand, the design of the energy band diagram has shown the ability of the formation of the Au/CYbC-40/Yb as Schottky (SB) and the Au/CYbC-40/Au as back to back Schottky barriers (BBSB). While the SB device show low band pass filter characteristics, the BBSB device performed as band stop filters. The BBSB device exhibited negative capacitance effects with filtering features that reveal a return loss of 42 dB at similar to 1440 MHz.Article Citation - WoS: 3Citation - Scopus: 6Adult Education as a Stepping-Stone To Better Jobs: an Analysis of the Adult Education Survey in Turkey(Sage Publications inc, 2018) Cilasun, Seyit Mumin; Demir-Seker, Sirma; Dincer, N. Nergiz; Tekin-Koru, AycaThe objective of this article is to investigate whether adult education (AE) can be used as a tool in facilitating transitions to/in the labor market, using the cross-sectional Adult Education Survey of Turkey (2012). AE is defined as the nonformal education for individuals aged older than 25 years. The outcome of AE is measured by changing jobs for employed and finding a job for the unemployed. Concentrating on employed people, we analyze both the determinants and the outcome of participation in AE for the purpose of changing jobs; and second, concentrating on unemployed people, we analyze both the determinants and the outcome of participation in AE for the purpose of getting employed. We find that once young males who are already working participate in AE for changing work, independent of their education or how AE is financed, they can be successful in doing so. The results of the paper suggest that AE programs offered by the government can serve as a tool in increasing income of the less educated and the unemployed by facilitating their transition to the labor market.Article Citation - WoS: 9Citation - Scopus: 9Thermally Stimulated Current Measurements in Undoped Ga3inse4< Single Crystals(Pergamon-elsevier Science Ltd, 2011) Isik, M.; Işık, Mehmet; Gasanly, N. M.; Işık, Mehmet; Department of Electrical & Electronics Engineering; Department of Electrical & Electronics EngineeringThe trap levels in nominally undoped Ga3InSe4 crystals were investigated in the temperature range of 10-300 K using the thermally stimulated currents technique. The study of trap levels was accomplished by the measurements of current flowing along the c-axis of the crystal. During the experiments we utilized a constant heating rate of 0.8 K/s. Experimental evidence is found for one hole trapping center in the crystal with activation energy of 62 meV. The analysis of the experimental TSC curve gave reasonable results under the model that assumes slow retrapping. The capture cross-section of the trap was determined as 1.0 x 10(-25) cm(2) with concentration of 1.4 x 10(17) cm(-3). (C) 2011 Elsevier Ltd. All rights reserved.Article Citation - WoS: 5Citation - Scopus: 6An Electrochromic Polymer Based on Cyclopenta[2,1-B;3,4 Effect of a Single Atom Alteration on the Electrochemical and Optical Properties of the Polymer Backbone(Elsevier Science Sa, 2020) Tutuncu, Esra; Varlik, Bengisu; Kesimal, Busra; Cihaner, Atilla; Ozkut, Merve Icli; Icli Ozkut, MerveAn electrochromic polymer, namely "poly(2,6-(3,3-didecyl-3,4-dihydro-2H-thieno [3,4-b] [1,4]dioxepin-6-yl)-4,4-dioctyl-4H-cyclopenta[2,1-b;3,4-b']dithiophene)" (P1), was electrochemically synthesized successfully, and its electrochemical and optical properties were investigated. The band gap of the polymer P1 was calculated as 1.77 eV with -5.45 eV Highest Occupied Molecular Orbital (HOMO) and -3.68 eV Lowest Unoccupied Molecular Orbital (LUMO) energy levels. The polymer P1 is bluish purple when neutralized and highly transparent greenish purple when oxidized. This color change was observed around 1.4 s between its redox states and optical contrast ratio was found to be as 49 % and 53 % with 234 cm(2)/C and 239 cm(2)/C coloration efficiencies at 590 nm and 634 nm, respectively. Moreover, the properties of this polymer were compared to its analogues and also during this comparison the effect of alteration of a single atom in the pendant unit was tried to be understood.Article Citation - WoS: 18Citation - Scopus: 18Fabrication of Al/Mgo and C/Mgo Tunneling Barriers for Tunable Negative Resistance and Negative Capacitance Applications(Elsevier Science Bv, 2013) Qasrawi, A. F.In this work, the design and characterization of magnesium oxide based tunneling diodes which are produced on Al and InSe films as rectifying substrates are investigated. It was found that when Al thin films are used, the device exhibit tunneling diode behavior of sharp valley at 0.15 V and peak to valley current ratio (PVCR) of 11.4. In addition, the capacitance spectra of the Al/MgO/C device show a resonance peak of negative capacitance (NC) values at 44.7 MHz. The capacitance and resistance-voltage characteristics handled at an ac signal frequency of 100 MHz reflected a build in voltage (V-bi) of 1.29 V and a negative resistance (NR) effect above 2.05 V. This device quality factor (Q)-voltage response is similar to 10(4). When the Al substrate is replaced by InSe thin film, the tunneling diode valley appeared at 1.1 V. In addition, the PVCR, NR range, NC resonance peak, Q and lib; are found to be 135, 0.94-2.24 and 39.0 MHz, similar to 10(5) and 1.34 V, respectively. Due to the wide differential negative resistance and capacitance voltage ranges and due to the response of the C/MgO/InSe/C device at 1.0 GHz, these devices appear to be suitable for applications as frequency mixers, amplifiers, and monostable-bistable circuit elements (MOBILE). (c) 2013 Elsevier B.V. All rights reserved.Article Factors Influencing the Transition Time From Psoriasis to Psoriatic Arthritis: A Real-World Multicenter Analysis(Springer Heidelberg, 2025) Kilic, Gamze; Kilic, Erkan; Tekeoglu, Ibrahim; Sargin, Betul; Cengiz, Gizem; Balta, Nihan Cuzdan; Nas, KemalTo identify clinical and demographic predictors associated with the timing of transition from psoriasis (PsO) to psoriatic arthritis (PsA), and to compare the characteristics of patients with concurrent PsO-PsA onset versus those with prolonged transition. A multi-center, observational study was conducted using data from the Turkish League Against Rheumatism (TLAR) network including PsA patients fulfilling CASPAR criteria. Patients were categorized into two groups: Group 1 (concurrent PsO and PsA onset within +/- 1 year) and Group 2 (prolonged transition to PsA, > 1 year after PsO). Demographic, clinical, and laboratory characteristics, disease activity, and patient-reported outcomes were compared between groups. Logistic regression was employed to determine independent predictors of prolonged transition. Among 799 patients (mean age 46.8 +/- 12.3 years), 237 (29.7%) had concurrent onset and 562 (70.3%) had a prolonged transition, with a mean PsO-to-PsA interval of 12.9 +/- 9.6 years. Depression (p = 0.005) and fatigue levels (p = 0.011) were significantly higher in patients with prolonged transition to PsA. Multivariate analysis revealed that scalp psoriasis (OR = 7.162), nail psoriasis (OR = 3.270), family history of PsO (OR = 1.813), and enthesitis ever (OR = 2.187) were associated with prolonged transition. Conversely, family history of PsA (OR = 0.421) and older age at PsO onset (OR = 0.957) predicted shorter transition. Prolonged transition from PsO to PsA is influenced by distinct clinical and demographic factors. Scalp/nail psoriasis, family history of PsO, and enthesitis ever may signal higher risk for prolonged PsA onset. Recognizing these markers can support timely referral and intervention, minimizing diagnostic delay and improving long-term patient outcomes.
