Zonguldak Bülent Ecevit University Institutional Repository
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In‐syringe homogeneous liquid‐phase microextraction followed by filtration‐based phase separation for on‐site extraction of chloroanilines from water samples
No full textThis study introduces a new in‐syringe homogeneous liquid‐phase microextraction method for the rapid on‐site extraction of chloroanilines from water samples. Extraction was performed using a plastic syringe, eliminating the use of any electrical power source. Di‐(2‐ethylhexyl) phosphoric acid (DEHPA) served as the extractant. The process initially involved dissolving DEHPA in an alkaline solution to obtain a homogeneous solution. Subsequently, the sodium salt of DEHPA was precipitated by salting‐out, and the resulting heterogeneous mixture was filtered using a syringe filter. The precipitate containing the analytes was then dissolved in methanol for analysis by high‐performance liquid chromatography. Under optimal conditions, extraction recovery for chloroanilines ranged from 26% to 71%. Method linearity was evaluated within a concentration range of 1.0–100 µg/L, resulting in coefficients of determination exceeding 0.9987 for all analytes. Method detection limits ranged from 0.28 to 0.41 µg/L. Intra and inter‐day precision values were below 9.5% and 10.8%, respectively. The developed method was applied to determine chloroanilines in real waters, yielding acceptable recoveries ranging from 80% to 109% for spiked tap, rain, and stream waters. Additionally, the method was successfully employed for on‐site extraction of target contaminants, demonstrating no statistically significant differences compared to laboratory results.</jats:p
Corredores de mandados del capitalismo de plataforma digital
No full textEste artículo describe un nuevo concepto denominado economía de los mandados. Examina el lado oscuro de la economía de plataforma y la “economía de changas” y hace una valiosa contribución a este campo. Estos conceptos, especialmente para los estudiosos liberales, ocultan el impacto negativo del capitalismo de plataforma en las relaciones de producción y en la clase trabajadora haciendo hincapié en las tecnologías digitales y el trabajo a destajo. La economía del mandado, sin embargo, pone especialmente de relieve la degradación del trabajo, independientemente de su cualificación, junto con procesos como la flexibilización, la precarización y la informalización. Esto se debe a que, en las condiciones de la economía del mandado, las plataformas tratan todos los tipos de trabajo como mandados baratos, sin valor y degradados. La principal misión de la economía de plataforma es acabar con el empleo utilizando el discurso de la flexibilidad y el emprendimiento y transformar a todos los asalariados en trabajadores de mandados clasificándolos como autónomos. Por este motivo, el artículo propone utilizar el concepto de economía del mandado junto con el de economía de plataforma, que se refiere a las infraestructuras digitales, y el de “economía de changas”, que hace hincapié en el trabajo a destajo.</jats:p
İlahiyat Fakültesi Öğrencilerinin Değer Yönelimleri ve Toplumsal Değer Dejenerasyonu Algıları Üzerine Bir Durum Çalışması
No full textBu çalışmanın amacı ilahiyat fakültesinde eğitimlerine devam eden öğrencilerin gerekçeleri ile önceledikleri üç ve toplumda dejenere olduğunu düşündükleri üç değeri incelemektir. Çalışmada karma araştırma yöntemi kullanılmıştır. Araştırmanın verileri anket ve görüşme formu ile elde edilmiştir. Çalışma grubunu kolay örneklem yöntemi ile seçilen Sivas Cumhuriyet Üniversitesi İlahiyat Fakültesi evreninde 25.2.2022-25.5.2022 tarihleri arasında çalışmaya gönüllü olarak katılan 207 öğrenci oluşturmuştur. Toplanan verilerin incelenmesinde SPSS programı ve içerik analizinden faydalanılmıştır. Katılımcıların önceledikleri değerler adalet, saygı ve dürüstlük; toplumda dejenere olduğunu düşündükleri değerler ise adalet, saygı ve mahremiyet olarak tespit edilmiştir. Katılımcıların bu değerleri tercih nedenlerinde içsel ve dışsal denilebilecek farklı sebepler rol oynamıştır. Öncelenen değerlerin tercih nedenleri üç, dejenere olan değerlere dair görüşler ise dört gerekçe altında toplanıp değerlendirilmiştir. Elde edilen veriler doğrultusunda kök değerler olarak eğitim programlarında yer alan bu değerlerin hayata yansıtılamamasında bilgi değil, içselleştirilememesinden kaynaklanan problemlerin olduğu sonucuna ulaşılmıştır. Çağın gerekleri ve ihtiyaçları doğrultusunda değer kazandırma yöntemleri yanında kök değerlerin güncellenmesi ve eklemeler yapılabileceği ortaya çıkmıştır.</jats:p
Fault Coalescence, Slip Distribution, and Stress Drop of the February 2023 Southeast Türkiye Earthquakes from Joint Inversion of SAR, GNSS, and Burst Overlap Interferometry
No full textAbstract Two devastating earthquakes struck southeastern Türkiye and northwestern Syria on 6 February 2023: an Mw 7.8 mainshock, followed 9 hr later by an Mw 7.6 aftershock. To recover and separate the subsurface geometry and slip distributions along the two earthquake faults, we jointly invert Interferometric Synthetic Aperture Radar, Synthetic Aperture Radar pixel offset tracking, burst overlap interferometry (BOI), Global Navigation Satellite System, and aftershock datasets. We introduce a new Kalman filter-based approach for merging spatially dense azimuth offset (AZO) data with the more precise yet spatially sparse BOI data. This procedure yields improved measurements of the displacements parallel to the near north-south satellite tracks, which are critical for resolving slip along most of the Mw 7.8 fault segments. We optimize the inversion using a new metric for assessing the degree of spatial correlation between the coseismic slip gradients and early aftershocks, resulting in a stable solution honoring the complementarity between the geodetic and aftershock datasets. The analysis suggests that the Mw 7.8 rupture consisted of three large segments and two short fault branches, covering about 300 km along the East Anatolian fault (EAF), whereas the Mw 7.6 rupture consisted of three segments extending for about 160 km along the nearby Sürgü fault (SF). On the basis of moment-to-stress-drop scaling relations, we show that the Mw 7.6 stress drop is four times larger than the Mw 7.8 stress drop, consistent with the larger recurrence intervals for Mw &gt; 7 earthquakes on the SF than on the EAF. The moment released during the 2023 Mw 7.8 earthquake is 2–4 times larger than the sum of the moments released during individual historical Mw &gt; 7 earthquakes along the three segments of the 2023 Mw 7.8 earthquake. Thus, when considering moment release for multisegment earthquakes, one should note that the final moment of fault coalescence is likely larger than the arithmetic sum of individual segment ruptures.</jats:p
The protective effect of angiotensin <scp>II</scp> type I receptor blocker (valsartan) on behavioral impairment, <scp>NLRP3</scp>, <scp>BDNF</scp>, and oxidative stress in the brain tissue of ovariectomized female rats
No full textAbstractDepression and anxiety are common mental health disorders affecting thoughts, behaviors, and emotions. This study aimed to investigate the effect of the angiotensin II type I receptor blocker (AT1RB), valsartan, on menopause‐induced depression and anxiety‐like behaviors, and to elucidate possible mechanisms of action by measuring levels of nod‐like receptor protein 3 (NLRP3), interleukin‐1beta (IL‐1β), brain‐derived neurotrophic factor (BDNF), and oxidative stress in brain tissue. Thirty‐two Wistar albino female rats were randomly divided into four groups (n = 8 per group): Control, AT1RB, OVX, and AT1RB + OVX. Following the bilateral ovariectomy (OVX) protocol, physiological saline was used as valsartan solvent, in a maximum volume of 0.4 mL, and valsartan was administered via intragastric gavage at a dose of 40 mg/kg/day. Depression and anxiety‐like behaviors were assessed using the forced swimming test and open field test. Levels of oxidative stress markers, NLRP3, IL‐1β, BDNF, and CREB were analyzed in the hippocampus and prefrontal cortex tissues. Behavioral tests indicated that depression and anxiety‐like behaviors significantly increased in OVX rats (p < 0.01), while AT1RB treatment significantly reduced these behaviors (p < 0.05). In the hippocampus of OVX rats, oxidative stress (p < 0.01), NLRP3 (p < 0.05), and IL‐1β (p < 0.01) levels were elevated, whereas BDNF levels were significantly decreased (p < 0.01). AT1RB treatment significantly improved oxidative stress parameters (p < 0.05) and BDNF levels (p < 0.01) but did not significantly affect the increased levels of NLRP3 and IL‐1β in OVX rats. In conclusion, AT1RB has a therapeutic effect on menopause‐induced depression and anxiety‐like behaviors, likely by reducing oxidative stress and increasing BDNF production in the hippocampus.</jats:p
Experimental Investigation of Hybrid Nanofluid Use in Automobile Cooling System and the Effect of New Front Grille Design on Cooling Load
No full textReduction of the harmful NOx pollutants emitted from the ship engines using high-pressure selective catalytic reduction system
No full textAbstractVarious techniques are used to reduce harmful pollutants such as NOX emissions from ships. Selective catalyst reduction (SCR) systems are the most effective technique used to reduce NOX emissions. In this study, the effects of an SCR reactor on NOX emissions and performance in high-pressure selective catalytic reduction (HP-SCR) systems were investigated numerically. In numerical studies, the effects of SCR system diameter, output form, catalyst activation energy, mixing zone length, and location were investigated as parametric, and the most suitable system geometry was determined. The effects of geometric parameters and catalyst type on emission and performance such as NOX reduction, NH3 slip, velocity, and pressure loss were investigated. It was determined that with increasing system diameter, whereas the NOX reduction performance increased depending on exhaust velocity, the pressure drop decreased, and the most suitable system diameter was determined as 780 mm. Furthermore, the obtained results showed that the performance of NOX reduction decreased after 2 × 106 kJ/kmol activation energy, and the most suitable SCR output form was conical geometry. In terms of the environment, this study will contribute to achieving the UN Sustainable Development Goals such as climate action (SDG 13).</jats:p
Dual techniques for trace copper determination: DES/Dithizone based liquid phase microextraction-flame atomic absorption spectrophotometry and digital image based colorimetric probe
No full textIn this study, a sample preparation procedure was developed to preconcentrate copper ions from aqueous samples for determination by flame atomic absorption spectrometry (FAAS) and digital image based colorimetry (DIC) systems. This was achieved by complexing copper ions with dithizone (Cu-DZ) and extracting the complex from aqueous solution in a single step. For the DES/DZ-FAAS system, a low detection limit of 2.3 ng mL-1 was recorded over a broad and linear working range. For the DIC system, the linear relationship between the change in red color intensity of the red-green-blue (RGB) color scale and the concentration of copper in the Cu-DZ complex was utilized for the validation of the method. The DIC system also recorded a broad and linear working range with a satisfactory detection limit of 14.7 ng mL-1. Spike recovery experiments performed with eucalyptus tea extracts yielded high recovery results in the range of 91-107%
Earthquake Experiences of Nursing Students Residing in Earthquake Zone, the Disaster of the Century: A Qualitative Study
No full text This study was carried out to examine the experiences of nursing department students regarding earthquakes with a phenomenological approach. The type of research is phenomenological research, one of the qualitative research methods. The research was carried out with 22 nursing students who experienced the earthquake in the Turkey earthquake on February 6, 2023. The data were collected using the “Semi-Structured Interview Form”. In this study, “earthquake experience” was discussed as a phenomenon, and the data obtained from the phenomenon after content analysis were evaluated in five themes as follows: Experiences during the earthquake, experiences after the earthquake, search-rescue operations, social support and daily life after the earthquake. It was seen that they acted with the instinct of protection during the earthquake and then tried to shelter and communicate. The study reveal that the disaster preparedness and competencies of nursing students should be increased. </jats:p
Design and synthesis of novel JNK inhibitors targeting liver pyruvate kinase for the treatment of non-alcoholic fatty liver disease and hepatocellular carcinoma
No full textNon-alcoholic fatty liver disease (NAFLD) comprises a broad range of liver disease including hepatocellular carcinoma (HCC) with is no FDA-approved drug. Liver pyruvate kinase (PKL) is a major regulator of metabolic flux and ATP generation in liver presenting a potential target for the treatment of NAFLD. Based on our recent finding of JNK-5A's effectiveness in inhibiting PKLR expression through a drug repositioning pipeline, this study aims to improve its efficacy further. We synthesized a series of JNK-5A analogues with targeted modifications, guided by molecular docking studies. These compounds were evaluated for their activities on PKL expression, cell viability, triacylglyceride (TAG) levels, and the expressions of steatosis-related proteins in the human HepG2 cell line. Subsequently, the efficacy of these compounds was assessed in reducing TAG level and toxicity. Compounds 40 (SET-151) and 41 (SET-152) proved to be the most efficient in reducing TAG levels (11.51 ± 0.90 % and 10.77 ± 0.67 %) and demonstrated lower toxicity (61.60 ± 5.00 % and 43.87 ± 1.42 %) in HepG2 cells. Additionally, all synthesized compounds were evaluated for their anti-cancer properties revealing that compound 74 (SET-171) exhibited the highest toxicity in cell viability with IC50 values of 8.82 µM and 2.97 µM in HepG2 and Huh7 cell lines, respectively. To summarize, compounds 40 (SET-151) and 41 (SET-152) show potential for treating NAFLD, while compound 74 (SET-171) holds potential for HCC therapy