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Makroekonomik değişkenlerin turizm ve borsa üzerindeki etkisi: BRIC ülkeleri üzerine bir uygulama
No full textThis study investigates the impacts of macroeconomic variables on tourism revenues and stock market returns in BRIC countries (Brazil, Russia, India, and China) using annual data from 1995 to 2020. The selected variables include the real effective exchange rate, inflation, gross domestic product (GDP), and exports. By employing the Panel ARDL methodology, the research examines both short-run and long-run dynamics between the variables. The findings indicate that inflation negatively affects stock market returns while GDP has a positive effect. On the other side, inflation shows a positive impact, whereas GDP negatively affects tourism revenues. The results suggest that during high inflation periods, investors prefer foreign currency-based investments, reducing stock returns. Conversely, economic growth increases investor confidence and enhances market performance. In terms of tourism, rising inflation may increase tourist spending due to favorable exchange rates, while economic growth, rising domestic prosperity, and currency appreciation may reduce the flow of foreign tourists. The study emphasizes that inflation and economic growth play pivotal roles in shaping both stock markets and tourism sectors, and different short and long-term impacts necessitate distinct strategies for policy makers. This research contributes to the literature by presenting comparative macroeconomic insights specific to BRIC nations.Bu çalışma, BRIC ülkelerinde (Brezilya, Rusya, Hindistan ve Çin) makroekonomik değişkenlerin turizm gelirleri ve hisse senedi getirileri üzerindeki etkilerini 1995-2020 dönemi yıllık verileri kullanarak incelemektedir. Çalışmada kullanılan makroekonomik değişkenler; reel efektif döviz kuru, enflasyon, gayrisafi yurt içi hasıla (GSYH) ve ihracattır. Panel ARDL yöntemiyle gerçekleştirilen analizde, hem kısa hem de uzun dönem ilişkiler ele alınmıştır. Elde edilen bulgular, enflasyonun borsa getirilerini negatif yönde etkilediğini, buna karşılık GSYH'nin pozitif bir etkisinin olduğunu ortaya koymaktadır. Turizm gelirleri açısından ise, enflasyonun pozitif, GSYH'nin ise negatif etkisi söz konusudur. Yüksek enflasyon dönemlerinde yatırımcıların dövize yönelmesi, borsa getirilerini azaltmaktadır. Öte yandan, ekonomik büyüme dönemlerinde yatırımcı güveni artmakta ve piyasa performansı yükselmektedir. Turizm tarafında ise, enflasyon artışı yabancı turist harcamalarını artırabilirken, ekonomik refah artışı ve kur değerlenmesi yabancı turist talebini azaltabilmektedir. Çalışmanın sonuçları, enflasyon ve ekonomik büyümenin her iki sektörde de belirleyici olduğunu ve bu nedenle politika yapıcıların kısa ve uzun vadeli farklı stratejiler geliştirmesi gerektiğini göstermektedir. Araştırma, BRIC ülkelerine özgü karşılaştırmalı makroekonomik değerlendirmeleriyle literatüre katkı sağlamaktadır
Calculating the carbon footprint of a paint factory in Bursa
No full textBu çalışmanın amacı Türkiye’nin en önemli sanayi kentlerinden biri olan Bursa ilinde faaliyet gösteren bir boya fabrikasının 2024 yılı karbon ayak izinin hesaplanmasıdır. Karbon ayak izi hesabı yapılan boya fabrikası yaklaşık 25 500 m2 ’lik bir tesis alanına ve 300 kişilik istihdam kapasitesine sahip olup 2024 yılı verisi olarak 18 830 361 kg boya üreten bir firmadır. Bu firmanın karbon ayak izi hesabı Hükümetlerarası İklim Değişikliği Paneli (IPCC)’nin Tier 1 metodolojisi kullanılarak gerçekleştirilmiştir. Çalışma neticesinde yıllık toplam karbon ayak izi miktarı yaklaşık 1 836,742 ton CO2e olarak bulunmuştur. Karbon ayak izi olarak en yüksek miktar 1 047,027 ton CO2e sonucuyla Kapsam 2 kategorisinde olan elektrik tüketimine aittir. Daha sonra en fazla karbon ayak izi miktarları sırasıyla Kapsam 1 kategorisinde bulunan 317,316 ton CO2e ile doğalgaz, 219,168 ton CO2e ile dizel ve 171,285 ton CO2e ile benzinden kaynaklanmaktadır. Bursa ilindeki boya fabrikasının 2024 yılı karbon ayak izi değerleri 2014 yılında yapılmış bir çalışmadaki Lahore şehrindeki bir boya fabrikasının karbon ayak izi değerleriyle karşılaştırılmıştır. Dikkat çekici nokta iki çalışmada da elektrik tüketimi kaynaklı emisyonların ilk sırayı almasıdır. Firmanın 2024 yılına ait karbon vergisi, halihazırda Türkiye’de uygulanmamasına rağmen, Avrupa ülkelerinin ton CO2e başına ortalama fiyat değeri alınarak hesaplandığında ise yaklaşık 3 161 181 TL olarak belirlenmiştir. Firmaların küresel rekabet alanında mücadele edebilmek ve geleceğe yönelik maaliyet hesaplamalarını öngörüp geleceğe hazırlanabilmeleri adına karbon vergisi konusu bir perspektif sunacaktır. Sektörel anlamda çok karşılaştığımız fakat literatürde az rastlanan boya endüstrisi karbon ayak izi hesaplamaları ile ilgili bu çalışma bu alandaki bundan sonra yapılacak çalışmalara ışık tutacaktır.The purpose of this study is to calculate the 2024 carbon footprint of a paint factory operating in Bursa, one of Türkiye's most important industrial cities. The paint factory whose carbon footprint was calculated has a facility area of approximately 25,500 m² and an employment capacity of 300 people. It is a company that produced 18 830 361 kg of paint in 2024. The carbon footprint calculation for this company was performed using the Tier 1 methodology of the Intergovernmental Panel on Climate Change (IPCC). As a result of the study, the total annual carbon footprint was found to be approximately 1 836,742 tons of CO2e. The highest carbon footprint amount, 1 047,027 tons of CO2e, belongs to electricity consumption in Scope 2. Subsequently, the highest carbon footprint amounts were from natural gas with 317,316 tons of CO2e in Scope 1, diesel with 219,168 tons of CO2e, and gasoline with 171,285 tons of CO2e. The carbon footprint values of the paint factory in Bursa province for 2024 have been compared with the carbon footprint values of a paint factory in Lahore city from a study conducted in 2014. It is noteworthy that electricity consumption-related emissions ranked first in both studies. Although the carbon tax for 2024 is not currently applied in Turkey, it has been calculated at approximately 3 161 181 TL, based on the average price per ton of CO2e in European countries. The carbon tax issue will provide a perspective for companies to compete globally and prepare for the future by anticipating future cost calculations. This study on carbon footprint calculations in the paint industry, which we encounter frequently in the sector but is rarely found in the literature, will shed light on future studies in this field
Three-dimensional soft tissue comparison in non-growing patients treated for skeletal Class II Division I malocclusion: Mandibular advancement surgery vs. Herbst Appliance
No full textOBJECTIVE: This study used three-dimensional (3D) stereophotogrammetry to compare changes in facial soft tissues of patients with skeletal class II malocclusion with mandibular retrognathia treated with orthognathic surgery (OS) or Herbst appliance (HA). METHODOLOGY: This retrospective study included 15 adults treated with bilateral sagittal split osteotomy without genioplasty (OS) and 16 adults treated with HA. The patients were treated successfully, with class I occlusal relationships with normal overjet and overbite. Three-dimensional stereophotogrammetric records acquired in habitual occlusion from before and after fixed orthodontic treatment were analyzed. Lateral cephalometric radiographs were used to evaluate skeletal parameters and sagittal oropharyngeal airway length. RESULTS: In HA-group, mandibular corpus length, anterior facial height, posterior facial height, Bº, vertical angle, and mentolabial angle increased; lower facial width, mandibular angle, mandibular convexity angle, ANBº, and Aº decreased. In OS-group, mandibular length, mandibular corpus length, and facial convexity angle increased significantly compared with those in HA-group; posterior facial height, Bº, vertical angle, and mentolabial angle also increased, but mandibular angle and ANBº decreased significantly. Only a significant difference in coordinate changes was observed for the pogonion in the sagittal direction. According to the cephalometric analysis, SNBº and Pg-NA perpendicular measurements increased significantly in the OS group compared with the HA group. In both groups, sagittal oropharyngeal airway length increased significantly post-treatment, with no significant intergroup difference. CONCLUSION: In patients treated with OS, skeletal advancement resulted in greater increases in mandibular and corpus lengths, along with forward positioning of the pogonion. Based on 3D soft tissue and cephalometric comparisons, the Herbst appliance seems to be a viable non-surgical alternative for young adults with moderate Class II malocclusion. Both treatment modalities also contributed to significant improvements in sagittal oropharyngeal airway length
Comparison of anesthetic and surgical outcomes between general anesthesia and dexmedetomidine-based sedoanalgesia in dacryocystorhinostomy surgery with bispectral index monitoring
No full textBackground: This study aimed to compare general anesthesia (GA) and sedoanalgesia (SA) with dexmedetomidine in terms of anesthetic and surgical outcomes in dacryocystorhinostomy (DCR) under bispectral index (BIS) monitoring. Methods: In this prospective randomized controlled study, 44 adult patients (≥ 18 y) were divided into two groups. Standard GA was induced in the GA group (n = 22), and dexmedetomidine-based SA in the SA group (n = 22). BIS monitoring was performed in all patients. Hemodynamic parameters, amount of intraoperative bleeding, duration of anesthesia and surgery, postoperative pain scores, complications, and patient and surgeon satisfaction were recorded. Results: The hemodynamic parameters, amount of intraoperative bleeding, duration of anesthesia and surgery, postoperative pain score, complications, and patient and surgeon satisfaction were similar between the two groups. Patient satisfaction was significantly higher in the SA group (p = 0.033). Conclusions: This study suggests that SA with dexmedetomidine accompanied by BIS monitoring can be an alternative to GA in selected patients undergoing external DCR surgery, because the anesthetic and surgical processes are similar to those of GA, and patient satisfaction is higher than that with GA. Trial Registration: ClinicalTrials.gov identifier: NCT05397301
Alternative electrode designs for hydrogen evolution reactions and asymmetric supercapacitor applications
No full textNikel köpüğün (NF) alttaş olarak kullanıldığı beş farklı elektrot elektrodepozisyon yöntemiyle üretilmiştir. Elektrotlar sırasıyla PANI/NF, rGO:PANI/NF, NiO@rGO:PANI/NF, CuO@rGO:PANI/NF, CuO:NiO@rGO:PANI/NF’dir. İlk iki elektrotta fırınlama işlemi olmasa da oksit içeren diğer elektrotlar da oksitlenmeyi güçlendirmek adına fırınlama işlemi uygulanmıştır. Elektrotların yüzey morfolojileri SEM analizleri, PANI/NF yüzeyine rGO, NiO ve CuO’nun etkisini araştırmak amacıyla kullanılmıştır. EDS analizleri ile C, N, O, Ni, Cu’ın yüzdesel kütle miktarları belirlenmiştir. FTIR, XRD ve XPS teknikleriyle elektrotların PANI, rGO, NiO ve CuO bileşenleri içerdikleri doğrulanmıştır. Üç elektrotlu ölçüm sistemi ve 0,5 M H2SO4 sulu çözelti kullanılarak yapılan ölçümlerde Tafel eğimleri PANI/NF, rGO:PANI/NF, NiO@rGO:PANI/NF, CuO@rGO:PANI/NF, CuO:NiO@rGO:PANI/NF elektrotları için sırasıyla 118,1, 112,2, 110,9, 87,1, 49,7 mV/derece olarak elde edilmiştir. Pt/C’nin Tafel eğimi ise 45,8 mV/derece olarak ölçülmüştür. Asimetrik cihaz, negatif elektrot olarak aktif karbon kumaş, pozitif elektrot olarak CuO:NiO@rGO:PANI/NF ve membran olarak da selüloz kağıt kullanarak elde edilmiştir. Çalışma penceresi 0 – 1,8 V aralığındadır. Elektrotların döngüsel voltametri (CV) çalışmaları gerçekleştirilmiştir. CV’lerden elde edilen sonuçlarda CuO:NiO@rGO:PANI/NF’nin kapasitans değerlerinde CuO ve NiO’in sinerjetik etkisi gözlemlenmiştir. EIS analizleriyle elektrotların ve asimetrik cihazın eşdeğer devre benzetimi yapılmıştır. Ölçümlerdeki en düşük akım değeri olan 16 Ag-1’de spesifik kapasitans değeri 92 F g-1, spesifik enerji değeri 32,7 Wh kg-1, spesifik güç değeri ise 1607,9 W kg-1’dir. Ölçümlerdeki en yüksek akım değeri olan 40 A g-1’de ise spesifik kapasitans değeri 44,1 Fg-1, spesifik enerji değeri 15,7 Wh kg-1, spesifik güç değeri ise 4745,6 W kg-1’dir. 10000 döngü sonunda yüzde 91,6 kapasitans tutma özelliği görülmüştür. Bu sonuçlar, CuO:NiO@rGO:PANI/NF bazlı asimetrik süperkapasitörün üstün elektrokimyasal performansını ve uzun süreli kararlılığını göstermekte olup, yüksek performanslı enerji depolama uygulamaları için büyük potansiyeli olduğunu göstermektedir.Using the electrodeposition technique, five different electrodes are fabricated on nickel foam (NF) substrates. The electrodes are PANI/NF, rGO:PANI/NF, NiO@rGO:PANI/NF, CuO@rGO:PANI/NF, and CuO:NiO@rGO:PANI/NF, respectively. Although the furnacing process is not applied to the first two electrodes, the other electrodes are subjected to furnacing to enhance oxide formation. SEM analyses of the electrode surface morphologies are employed to investigate the effects of rGO, NiO, and CuO on the PANI/NF surface. EDS analyses are used to determine the percentage mass contents of C, N, O, Ni, and Cu. The coating of the nickel foam with PANI, rGO, NiO, and CuO is confirmed by FTIR, XRD, and XPS analyses. Tafel slopes are 118,1, 112,2, 110,9, 87,1, 49,7 mV/dec for PANI/NF, rGO:PANI/NF, NiO@rGO:PANI/NF, CuO@rGO:PANI/NF, CuO:NiO@rGO:PANI/NF electrodes, recpectively, with using three electrode measurement system and 0.5 M H2SO4 solution. Tafel slope of Pt/C is determined to be 45,8 mV/dec. Asymetric supercapacitor device is obtained using activated carbon fabric as negative electrode, CuO:NiO@rGO:PANI/NF as positive electrode and selulose paper as membrane. The operating potential window of the electrode is 0–1.8 V. Cyclic voltammetry results are obtained for the electrodes. A synergistic effect of CuO and NiO is observed in the capacitance values of the CuO:NiO@rGO:PANI/NF electrode, as evidenced by the CV measurements. Equivalent circuit modeling of the electrodes and the asymmetric device is performed using EIS analyses. The asymmetric supercapacitor device delivers a specific capacitance of 92 F g-1, a specific energy of 32.7 Wh kg-1, and a specific power of 1607.9 W kg-1 at a current density of 16 A g-1. At the highest current density of 40 A g-1, the specific capacitance is 44.1 F g-1, the specific energy is 15.7 Wh kg-1, and the specific power is 4745.6 W kg-1. After 10000 cycles, a capacitance retention of 91.6% is observed. These results demonstrate the outstanding electrochemical performance and long-term stability of the CuO:NiO@rGO:PANI/NF-based asymmetric supercapacitor, highlighting its great potential for high-performance energy storage applications
Preparation, characterization, and antimicrobial activities of ceragenins incorporated into polyvinyl alcohol/gelatin/sodium alginate-based hydrogels for treatment of burn wounds
No full textCeragenins are synthetic molecules that mimic antimicrobial peptides (AMPs) in the human immune system. They feature a bile acid-based structure with appended positively charged groups that disrupt bacterial cell membranes, leading to microbial cell death or inactivation. In this study, ceragenin CSA-44 was incorporated into a polyvinyl alcohol (PVA)/gelatin (G)/sodium alginate (SA)-based hydrogel (PGA-CSA). The hydrogel was cross-linked with glutaraldehyde (GA) for 20 min using a 0.125% GA (v/v) solution. The optimized volume ratios of the polymer solutions in the hydrogel were determined to be 2:1:3 (PVA:SA:G). PGA-CSA and PGA hydrogels were characterized using scanning electron microscopy (SEM), mercury porosimetry, and Fourier transform infrared spectroscopy (FTIR). The maximum swelling ratio of PGA-CSA was 780.48% +/- 14.80%, and the WVTR value was 905.4 +/- 35.4 g/m2/d. Drug release studies showed a cumulative CSA-44 release of 29.07% over 7 days. The antibacterial activity of the hydrogel was tested against Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 19151, Staphylococcus aureus ATCC 29213, and MRSA. The tested bacteria were inhibited within 2, 2.5, 3, and 3.5 h, respectively. The developed PGA-CSA hydrogel demonstrated outstanding potential and unique characteristics as an antibacterial dressing for burn wounds
Free vibration analysis of variable cross-section micro columns reinforced with short-fibers via the modified couple stress theory
No full textBu çalışmada, değişken kesitli kompozit mikro kolonların boyut etkisine bağlı serbest titreşimi sunulmuştur. Kompozit mikro kolonlar kısa fiberler ile güçlendirilmiş polimer bir matristen oluşmaktadır. Kompozit mikro kolonlarda kısa fiberler polimer matris içerisine rastgele dağılmaktadır. Kısa fiberler ile güçlendirilmiş mikro kolonların etkili elastisite modülü, fiber geometrisini ve yönelimini dikkate alan Halpin-Tsai modeli kullanılarak hesaplanırken etkili kütle yoğunluğu karışım kuralı ile elde edilmiştir. Mikro kolonların kesiti hem yükseklik hem de genişlik yönünde doğrusal bir değişim göstermektedir. Ayrıca, küçük ölçeklerde önemli bir parametre olan boyut etkisi değiştirilmiş gerilme çifti teorisi ile araştırılmıştır. Ankastre-ankastre ve ankastre-serbest sınır koşullarında ele alınan mikro kolonlar ince bir yapı formunda düşünülmüş ve bu nedenle Bernoulli-Euler kiriş teorisinin varsayımları dikkate alınmıştır. Kısa fiberler ile güçlendirilmiş değişken kesite sahip mikro kolonların temel titreşim frekanslarını hesaplamak için Rayleigh-Ritz yöntemi kullanılmıştır. Elde edilen temel titreşim frekansları ile yükseklik yönündeki değişim oranının, genişlik yönündeki değişim oranının, çift yönlü koniklik oranının, fiber elastisite modülünün, fiber kütle yoğunluğunun, fiber hacim oranının, malzeme uzunluk ölçek parametresinin ve fiber uzunluk/çap oranının etkileri detaylı bir şekilde araştırılmıştır.In this study, the free vibration of variable cross-section composite micro columns depending on the size effect is presented. Composite micro columns consist of a polymer matrix reinforced with short-fibers. In composite micro columns, short-fibers are randomly distributed within the polymer matrix. The effective elasticity modulus of short-fiber-reinforced micro columns is calculated using the Halpin-Tsai model, which takes into account fiber geometry and orientation, while the effective mass density is obtained using the rule of mixture. The cross-section of the micro columns exhibits a linear variation in both height and width directions. Additionally, the size effect, an important parameter at small scales, is investigated using the modified couple stress theory. Micro columns considered under clamped-clamped and clamped-free boundary conditions are conceived as a slender structure and therefore the assumptions of Bernoulli-Euler beam theory are taken into account. The Rayleigh-Ritz method is used to calculate the fundamental vibration frequencies of micro columns with variable cross-sections reinforced with short-fibers. The effects of the variation ratio in the height direction, the variation ratio in the width direction, the double tapered ratio, the fiber elasticity modulus, the fiber mass density, the fiber volume ratio, the material length scale parameter and the fiber length/diameter ratio on the fundamental vibration frequencies of the variable cross-section composite micro column are investigated in detail via the obtained fundamental vibration frequencies
Leveraging IoT and smart city governance frameworks to enable sustainable urban development
No full textSecond-generation braf inhibitor encorafenib resistance is regulated by ncoa4-mediated iron trafficking in the drug-resistant malignant melanoma cells
No full textThe current study established the first in vitro Encorafenib resistance protocol in BRAF-mutated malignant melanoma (MM) cells and investigated the resistance-related mechanisms. After establishing Encorafenib-resistant A375-MM cells, resistant-related mechanisms were investigated using WST-1, Annexin V, cell cycle, morphological analysis, live-cell, Western blot, RNA-Seq, transmission electron microscopy-(TEM), oxidative stress and iron colorimetric assay. The most resistant group, called A375-R, was determined in the cells treated with a constant dose of 10 nM over 3 months. The viability, apoptosis, and G0/G1 arrest reflected the acquired chemoresistance. Autophagic Beclin and LC3 proteins, and AKT signaling increased in the A375-R. RNA-Seq results also exhibited altered epigenetic regulation of resistance; particularly ferritin family members, ion transport pathways. Then, increased NCOA4, FTH1, and iron levels detected in A375-R suggest that the iron metabolism-related mechanism, such as ferritinophagy, might be triggered, which was supported by TEM and oxidative stress analysis. Iron storage, transport, and ferritinophagy have the promising potential to be targeted for combining with BRAF-targeted therapy to reverse Encorafenib resistance in MM. Moreover, this is the first study evaluating in vitro Encorafenib resistance mechanisms, and we suggest that our findings contribute to improving new drug combinations targeting BRAF and iron metabolism in different MM cells
An inverse parameter identification in finite element problems using machine learning-aided optimization framework
No full textBackgroundThe ability of finite element analysis to produce high fidelity results is greatly dependent on quality of constitutive model and the accuracy of their parameters. As such, the calibration of phenomenological constitutive models to replicate real-world behaviors has remained a focal point of many research works.ObjectiveA new inverse identification approach combining numerical-experimental methods and data-driven techniques to characterize the nonlinear response of materials using a single experiment is proposed.MethodsThis approach integrates finite element analysis, optimization methods and machine learning techniques, such as Artificial Neural Networks and Support Vector Regression, to accurately determine model parameters while significantly reducing computational time. This approach can be used to characterize a wide range of models irrespective of the number of parameters involved. A detailed flowchart of the methodology focusing on its implementation aspects is provided and its each module is explained.ResultsThe proposed model calibration approach successfully identified eight parameters for a cohesive zone model implemented in user element subroutine (UEL), four parameters for a hardening model implemented in user material subroutine (UMAT), and five parameters for a Johnson-Cook plasticity model. In all cases, this method achieved an excellent fit between the simulation and experimental results. Moreover, it demonstrated a significant improvement in efficiency, being 2-3 times faster than traditional optimization algorithms in determining optimal parameters.ConclusionsBased on the presented investigations, the proposed machine learning-based inverse method can significantly accelerate the parameter identification procedure and can be extended to a wide range of material models