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Effect of graphene nanoplatelets (GnPs) on low velocity impact properties of hybrid kevlar/basalt fiber reinforced epoxy based composites
No full textIn the present study, the effects of hybridization of Basalt and Kevlar fibers in conjunction with the incorporation of Graphene nanoplatelets (GnPs) on the performance under low-velocity impact were experimentally examined. Two different hybrid structural configurations, reinforced with Basalt and Kevlar composites, were fabricated utilizing a hand lay-up technique followed by vacuum bag molding, with variations that included and excluded GnPs. The synergistic effects of hybridization coupled with the modification by GnPs on the impact characteristics of the Basalt/Kevlar hybrid composites were analyzed under an impact energy of 30 J while varying the GnPs loading. The optimal enhancement observed in the peak load and absorbed energy of the specimens was recorded as a 9.4 % and 45.7 % improvement, respectively, when Kevlar fibers were positioned in the outer layers; conversely, the specimens demonstrated enhancements of 13.35 % and 20.36 % in peak load and absorbed energy with the incorporation of 1 wt% and 3 wt% GnPs when Basalt fibers were situated in the outer layers. The increase of the impact properties of the hybrid structures was ascribed to the robust interfacial interactions established among the fibers, epoxy, and GnPs nanoparticles, which facilitated a notable enhancement in performance and optimal stress transfer from the fibers and nanoparticles to the matrix
Understanding twitter in crisis: a roadmap for public sector decision makers with multi-criteria decision making
No full textThis study was developed to emphasize the critical role of social media in large-scale crises and the importance of effective information flow management. By analyzing how the Twitter platform (now X) can be utilized in crisis management, this paper presents an integrated framework that combines Multi-Criteria Decision-Making (MCDM) methods. The Improved Entropy technique is employed to prioritize classified tweets, while the Compromise Ranking of Alternatives from Distance to Ideal Solution (CRADIS) approach is used to evaluate the significance of crisis days. To validate the applicability and consistency of the proposed approach, a case study was conducted using tweets from the official Twitter account of the Disaster and Emergency Management Authority (AFAD) related to the earthquake that occurred in Turkey on February 6, 2023. The findings reveal that the Improved Entropy method identifies calls for help as the highest priority category in crisis response. CRADIS results further highlight that the second day of the disaster is the most critical, as it is the period when the scope of the crisis becomes clearer and coordination efforts are most intense. Comprehensive sensitivity analyses confirm that the proposed unified MCDM framework is both reliable and consistent. This study underscores the importance of timely and accurate information dissemination through social media in crisis management and offers a decision-support model that facilitates flexible and rational decision-making for authorities. This model can guide the development of more effective response strategies in future crisis scenarios
Critical Analysis of Jean-François Millet's Work 'Women Collecting Springs' According to the Holistic Approach to Art Criticism
No full textBu çalışma, Jean François Millet'in "Başak Toplayan Kadınlar" adlı eserinin Sanat Eleştirisi Bütüncül Yaklaşım İzleği çerçevesinde eleştirel çözümlemesini sunmaktadır. Araştırma, nitel araştırma yöntemlerinden betimsel analiz ve mantıksal akıl yürütme teknikleri kullanılarak gerçekleştirilmiştir. Söz konusu eserin kompozisyonu, renk kullanımı, ve figürlerin duruşu gibi görsel unsurların yanı sıra, toplumsal mesajları ve temaları incelenmiştir. Araştırma bulguları, "Başak Toplayan Kadınlar" adlı eserde realist üslubun emekçi sınıfın günlük yaşamını özgün bir biçimde tasvir ettiğini ve sanatçının toplumsal eşitlik ile emekçi sınıflara olan saygısını vurguladığını göstermiştir. Ayrıca, bu eser, Barbizon ekolünün doğa ve tarımsal emeğe duyduğu estetik ilgiyi güçlü bir şekilde ortaya koyduğu görülmüştür. Sonuçlar, ise bulgulara bağlı kalarak sanatın yalnızca soylu sınıfların temsilinden ibaret olmadığını, aynı zamanda emekçi sınıfların günlük mücadelelerini estetik ve toplumsal değerlerle ilişkilendirdiğini ortaya koyarak, figürlerin doğal çevre içerisinde gerçekçi bir şekilde betimlendiğini göstermiştir. Bu bağlamda eser, hem toplumsal eşitlik vurgusu hem de Barbizon ekolünün doğa ve tarımsal üretime yönelik estetik duyarlılığı açısından sanat tarihi içinde önemli bir konuma sahip olduğu görülmüştür.This study presents a critical analysis of Jean François Millet's work "Women Who Collect Virgos" within the framework of the Holistic Approach of Art Criticism. The research was carried out by using descriptive analysis and logical reasoning techniques from qualitative research methods. In addition to the visual elements such as the composition of the work in question, the use of color, and the posture of the figures, its social messages and themes were examined. The research findings have shown that the realist style depicts the daily life of the working class in an original way in the work entitled "Women Who Collect Virgo" and emphasizes the artist's respect for the working classes with social equality. In addition, it has been seen that this work strongly reveals the aesthetic interest of the Barbizon school in nature and agricultural labor. The results showed that art is not only a representation of the noble classes, adhering to the findings, but also relates the daily struggles of the working classes to aesthetic and social values, showing that the figures are depicted realistically in the natural environment. In this context, it has been seen that the work has an important position in the history of art both in terms of its emphasis on social equality and the aesthetic sensitivity of the Barbizon school towards nature and agricultural production
Post-Earthquake PTSD: Identifying Key Risk Factors Eleven Months After the February 2023 Turkey Earthquakes
No full textAmaç Depremler, fiziksel hasara ve hayatta kalanlar arasında psikolojik strese neden olan en önemli doğal afetlerden biridir. Depremler sonrasında ortaya çıkabilecek en önemli ruh sağlığı sorunlarından biri Travma Sonrası Stres Bozukluğu’dur (TSSB). Bu çalışmada, 6 Şubat 2023 Türkiye depremlerinden on bir ay sonra TSSB yaygınlığı ve TSSB risk faktörlerinin incelenmesi amaçlanmıştır. Yöntem Çalışma, 19 Aralık 2023 ile 2 Ocak 2024 tarihleri arasında gerçekleştirilmiştir. Tüm katılımcılara Kişisel Bilgi Formu ve DSM-5 Travma Sonrası Stres Bozukluğu Kontrol Listesi (PCL-5) uygulanmıştır. Kişisel Bilgi Formu üç bölümden oluşmaktadır: hayatta kalanların demografik özellikleri, travmanın özellikleri ve travma sonrası dönem özellikleri. Bulgular Çalışmaya 18-65 yaş aralığında toplam 886 katılımcı dahil edilmiştir. Katılımcıların %55,4'ü (n=491) TSSB tanı kriterlerini karşılamaktadır. TSSB tanısı alma olasılığı erkek bireylerde 2,95 kat, yaralanan bireylerde 2,07 kat, kaçamayacağını hisseden bireylerde 2,30 kat ve aşırı korku veya panik yaşayan bireylerde 2,03 kat daha yüksek bulunmuştur. Ayrıca, aile üyesi veya yakın bir arkadaşı yaralanan bireylerde bu olasılık 1,65 kat, deprem sonrası işini kaybeden bireylerde 1,82 kat ve ekonomik sorunlar yaşayan bireylerde 1,67 kat daha fazladır. Sonuç Erkek cinsiyet, kaçışın imkansız olduğu algısı, aşırı korku veya panik yaşama, bir aile üyesi ya da yakın arkadaşın yaralanmasına tanıklık etme, deprem sonrası iş kaybı ve ekonomik sorunlarla karşı karşıya kalma, TSSB için önemli risk faktörleri olarak belirlenmiştir.Objective Earthquakes are one of the most significant natural disasters, causing physical damage and psychological stress among victims. One of the major mental health issues that can arise after earthquakes is Posttraumatic Stress Disorder (PTSD). Our study aimed to investigate the prevalence of PTSD and PTSD risk factors in the eleventh month following the February 6, 2023 earthquakes in Turkey. Methods Our study was conducted between Dec 19, 2023, and Jan 2, 2024. All participants were given the Personal Information Form and, PTSD Checklist for DSM-5 (PCL-5). The Personal Information Form consists of three parts: survivors' characteristics, the characteristics of the trauma, and the post-trauma characteristics of the survivors. Results The study involved a total of 886 participants, aged between 18 and 65 years. Among the participants, 55.4% (n=491) were considered to have PTSD. The likelihood of receiving a diagnosis of PTSD is 2.95 times higher for male individuals, 2.07 times higher for injured individuals, 2.30 times higher for those who feel unable to escape their situation, and 2.03 times higher for individuals experiencing excessive fear or panic. Additionally, it is 1.65 times higher for individuals whose family member or close friend is injured, 1.82 times higher for individuals who lose their job after the earthquake, and 1.67 times higher for individuals experiencing economic problems after the earthquake. Conclusion Male gender, feeling trapped, experiencing extreme fear or panic, witnessing the injury of a family member or close friend, losing one's job after the earthquake, and facing economic problems after the earthquake are risk factors for PTSD
Reliability of different formulas for estimating plasma Apolipoprotein B levels in a large cohort of South European individuals
No full textBackground and aims: Direct measurement of apolipoprotein B (ApoB) is not always standardized and is relatively expensive, making it unavailable in several low-income settings. To address this issue, several formulas have been developed to estimate ApoB levels. Therefore, our study aims to compare the reliability of 23 formulas for estimating ApoB levels in a large cohort of South-European individuals. Methods: We retrospectively assessed 4.577 clinical records in which ApoB measurements were obtained using the same standardized method. Overall concordance was defined as the proportion of cases where the directly measured ApoB level fell within the same category as the estimated ApoB level, based on ApoB quartiles (= 115 mg/dL). In addition, overall concordance was assessed for different lipoprotein(a) (Lp(a)) and non-high density lipoprotein cholesterol (non-HDL-C) sub-levels. Ordinary least squares linear regression analyses were performed to compare estimated and measured ApoB values. Residual error plots were generated to visualize the difference between each estimation method and the actual ApoB measurements, stratified by Lp(a) and non-HDL-C levels. Results: Plasma ApoB levels were best predicted by a non-HDL-C based formula and a formula using Friedewald's low-density lipoprotein cholesterol (LDL-C), regardless of ApoB plasma levels. Non-HDL-C levels did not significantly affect the concordance between measured and estimated ApoB across the different formulas, except at low non-HDL-C levels. Similarly, Lp(a) levels did not significantly impact concordance. However, the highest concordance level was 41 %. Conclusion: Some simple formulas based on low-cost and widely available parameters can estimate ApoB levels independently of ApoB, non-HDL-C, and Lp(a) plasma levels. This approach may be particularly useful for estimating ApoB levels in low-resource settings.Institutional Fundings by the University of BolognaThis research was supported by the Institutional Fundings by the University of Bologna (RFO2022 and RFO2023)
2002-2024 Yılları Arasında Gıda ve Nanoteknoloji Üzerine Yapılan Çalışmaların Bibliyometrik Analizi
No full textNanotechnology is a discipline with essential application areas in the food industry, such as the production, processing, and packaging of foods. Nanotechnology applications are increasing daily in various areas of the food industry. This study aims to examine the studies on food and nanotechnology in the literature using the bibliometric analysis method. In the Web of Science (WoS) database, studies in the type of articles and review articles in which the concepts of “food” and “nanotechnology” were mentioned were scanned, and a total of 1950 studies were reached. Some data obtained in the study were visualized with the VOSviewer mapping technique. When the data obtained was examined, it was determined that the first study in the type of article on food and nanotechnology was published in 2002, and most studies on the subject were published in 2021 (197 articles). It was observed that the countries with the most studies were United States of America (USA) (354 articles), People’s Republic of China (311 articles) and India (255 articles). The number of studies conducted in Turkey was 56. Among the indexes where studies were scanned, Science Citation Index Expanded (SCI-EXPANDED) ranked first with 1503 articles, while the journal in which the most studies were published was Elsevier (842 articles). While the most used publication title in the studies was “journal of agricultural and food chemistry”, it was determined that the most used keywords were “nanotechnology” and “nanoparticles”. Considering the number of studies conducted on nanotechnology in the world, the importance of making the necessary investments and training human resources in order for Turkey to reach a competitive position with other countries in the field of nanotechnology, which is considered the technology of the future and has very important applications in the food sector, becomes evident.Nanoteknoloji gıda endüstrisinde gıdaların üretimi, işlenmesi, ambalajlanması gibi konularda önemli uygulama alanına sahip bir disiplindir ve gıda endüstrisinin çeşitli alanlarında nanoteknoloji uygulamaları gün geçtikçe artmaktadır. Bu çalışmanın amacı, bibliyometrik analiz yöntemini kullanarak literatürde yer alan gıda ve nanoteknoloji ile ilgili çalışmaları incelemektir. Web of Science (WoS) veri tabanında, “food” ve “nanotechnology” kavramlarının geçtiği makale ve derleme makale türünde çalışmalar taratılmış ve toplam 1950 çalışmaya ulaşılmıştır. Çalışmada elde edilen bazı veriler, VOSviewer haritalama tekniği ile görselleştirilmiştir. Elde edilen veriler incelendiğinde, gıda ve nanoteknoloji ile ilgili makale türünde ilk çalışmanın 2002 yılında yayımlandığı, konuya dair en fazla çalışmanın ise 2021 yılında (197 makale) yapıldığı belirlenmiştir. En fazla çalışma yapan ülkelerin sırasıyla Amerika Birleşik Devletleri (ABD) (354 makale), Çin Halk Cumhuriyeti (311 makale) ve Hindistan (255 makale) olduğu görülmüştür. Türkiye’de yapılan çalışma sayısı 56 olmuştur. Çalışmaların tarandığı indeksler arasında ilk sırada 1503 makale ile Science Citation Index Expanded (SCI-EXPANDED) yer alırken, çalışmaların en fazla yayımlandığı dergi Elsevier (842 makale) olmuştur. Çalışmalarda en çok kullanılan yayım başlığı “tarım ve gıda kimyası yayını” olurken, en fazla kullanılan anahtar kelimelerin “nanoteknoloji” ve “nanopartiküller” olduğu tespit edilmiştir. Dünyada nanoteknoloji konusunda yapılan çalışma sayıları dikkate alındığında, geleceğin teknolojisi olarak kabul edilen ve gıda sektöründe çok önemli uygulamalara sahip nanoteknoloji alanında Türkiye’nin diğer ülkelerle rekabet edebilir bir konuma ulaşması için gerekli yatırımların yapılması ve insan kaynaklarının yetiştirilmesinin önemi ortaya çıkmaktadır
The new metal-free, zinc, magnesium, indium ball-type phthalocyanines and their hybrids with graphene oxide: Synthesis, investigation of photophysical, photochemical properties and theoretical studies
No full textIn this study, four ball-type phthalocyanines (BTPc-H2-4, BTPc-Zn-5, BTPc-Mg-6, BTPc-In-7) were synthesized from 3,3 ',((3,5-di-tert-butyl-1,2-phenylene)bis(oxy)diphthalonitrile in a single reaction step. Non-covalent balltype phthalocyanine (BTPc)-graphene oxide (GO) hybrids (BTPc-GO) were prepared by simple sonication method. The structures were confirmed by elemental analysis, ultraviolet-visible (UV-Vis), fourier-transform infrared (FT-IR), proton nuclear magnetic resonance (1H NMR), MALDI-TOF MS spectroscopies, elemental analysis and scanning electron microscope (SEM). The photophysical and photochemical properties of ball-type phthalocyanines were investigated in dimethyl sulfoxide (DMSO) and tetrahydrofuran (THF). In this way, the contribution of solution polarity to these properties was compared. The contribution of GO was examined by examining the singlet oxygen quantum yields of BTPc-GO hybrids in DMSO. In addition, the structural properties of ball-type phthalocyanines were examined through theoretical studies and the effect of structural properties on experimentally determined band gaps was examined. Interestingly, we also report that ball-type thalocyanines are both photostable and exhibit extremely high singlet oxygen quantum yields. In addition, we can state that hybrids of these compounds with GO also show the ability to increase the singlet oxygen quantum yield, depending on the degree of interaction
Determination of the prevalence of complete type retrotransverse and arcuate foramen of the atlas using three-dimensional computed tomography images
No full textPurpose To determine the prevalence of complete type retrotransverse (RTF) and arcuate foramen (AF)'s in a large cohort using three-dimensional (3D) computed images (CT) and explore their correlation with each other. MethodsBetween January 2023 and August 2024, all neck and cervical vertebrae CTs taken in our hospital were scanned retrospectively. It is noted the presence or absence of complete RTF and AF, laterality, gender, and age of those included in the study. Results A total of 2000 patients were included in the study, with an equal distribution of females and males. The prevalence of complete AF was 6.4%, 10%, and 16.3% bilaterally, unilaterally, and in total. The prevalence of complete AF was 12% in females and 20.6% in males. The gender prevalence differences of bilateral AF were statistically significant (p < 0.001). The prevalence of complete RTF was 1.8%, 8.9%, and 10.6% bilaterally, unilaterally, and in total. The prevalence of complete RTF was 9.7% in females, and 11.6% in males. The prevalence differences between genders were insignificant (p = 0.173). The ipsilateral prevalence of complete AF and RTF was 0.2%, 0.2%, and 0.4%, respectively, bilateral, unilateral right, and unilateral left. Conclusions The complete AF and RTF prevalences in the study group were not uncommon. The prevalence of complete AF and RTF together is quite rare. Complete RTF is more common in elderly patients and on the left side, while complete AF does not show any difference in laterality and age, and is more common in males than in females.Hacettepe University Faculty of MedicineThe study abstract was presented orally with preliminary data at the 23rd National Anatomy Congress, organized by the Turkish Anatomy and Clinical Anatomy Association and Hacettepe University Faculty of Medicine, Department of Anatomy, between 11 and 15 October 2023
Immobilization of amylase in chitosan bead
No full textBu çalışmada amilaz enziminin, çapraz bağlayıcı aracılığıyla boncuk formuna getirilen kitosan destek materyaline immobilize edilmesi sağlandı. İmmobilize amilazın protein tayinine bağlı olarak adsorpsiyon çalışması ve farklı sıcaklıklardaki bağlanan protein miktar tayini yapıldı. Sonuçlar ele alınacak olursa; adsorpsiyon Freundlih izotermine uyum sağlamıştır. pH arttıkça adsorpsiyonun arttığı, pH 6 - 9 arasında maksimum absorbsiyon gerçekleştiği ve en fazla proteinin 55°C'de bağlandığı gözlenmiştir. Çalışılan koşullar sırası ile incelendiğinde; serbest amilaz enziminin optimum pH'ı 7 olarak, immobilize amilazın ise optimum pH'ı 9 olarak belirlenmiştir. Her iki enziminde optimum sıcaklığı 55ºC olarak belirlenmiştir. Her iki enziminde 55°C ile 75°C aralığındaki sıcaklıklarda yüksek kararlılık göstermişlerdir. Yapılan aktivite hesabı sonucunda doygun substrat derişimi %2,50 olarak belirlenmiştir. Her iki enziminde deney ortamına inhibitör ve aktivatör eklenip aktivite hesapları yapılarak ayrı ayrı Linewear Burk grafiği çizildi. Km değerleri sırasıyla % 2,44; % 2,57; % 2,00 (w/v) nişasta iken Vmax değerleri ise sırasıyla 67,34; 55,56; 79,37 µmol mgport-1dk-1 olarak hesaplanan serbest amilazın inhibisyon türü "Karışık Tip İnhibisyon" olarak bulunmuştur. İmmobilize amilazın inhibitörsüz, inhibitörlü ve aktivtörlü olacak şekilde aktivitesi hesaplanarak, Linewear Burk grafiği çizilmiştir. Km %2,0 (w/v) nişasta inhibitörlü, inhibitörsüz, aktivatörlü immobilize amilaz için ortak bir değerdir. Vmax değerleri ise sırasıyla 0,000098; 0,000072; 0,000122 µmol mgport-1dk-1 olarak hesaplanmıştır. İmmoblize amilaz "Yarışmamız İnhibisyon" türüne sahiptir. Bu analizler dışında immobilize enzimin tekrar kullanılabilirliği ve depo kararlılığı gibi koşullarda serbest enzime göre daha kararlı olduğu söylenebilir.In this study, the enzyme amylase was immobilized onto a chitosan support material in bead form via a cross-linking agent. Adsorption studies based on the protein determination of the immobilized amylase and quantification of the amount of bound protein at different temperatures were carried out. The results revealed that the adsorption conformed to the Freundlich isotherm. It was observed that adsorption increased as the pH increased, with maximum adsorption occurring between pH 6 and 9, and the highest amount of onto. When the studied conditions were examined sequentially, the optimum pH for free amylase was determined as 7, while the optimum pH for immobilized amylase was determined as 9. The optimum temperature for both enzymes was found to be 55°C. Both enzymes exhibited high stability within the temperature range of 55°C to 75°C. Based on the activity calculations, the saturated substrate concentration was determined to be 2.50%. For both enzymes, activities were calculated by adding inhibitors and activators to the experimental environment, and separate Lineweaver-Burk plots were created. The Km values were determined as %2,44; %2,57; %2,00 (w/v) starch, while the Vmax values were calculated as 67.34; 55.56 and 79.37 µmol mgport-1 dk-1 for free amylase. The inhibition type for free amylase was identified as "Mixed-Type Inhibition." The activity of immobilized amylase was calculated under inhibitor-free, inhibitor-present, and activator-present conditions, and a Lineweaver-Burk plot was created. The Km value for immobilized amylase was determined to be %2,0 (w/v) starch, common for all three conditions. The Vmax values were calculated as 0.000098; 0.000072 and 0.000122 µmol mgport-1 dk-1, respectively. Immobilized amylase exhibited "Non-competitive Inhibition." Apart from these analyses, it can be concluded that the immobilized enzyme is more stable than the free enzyme in terms of conditions such as reusability and storage stability
Examination of the cooling performance of the lithium-ion battery module created using phase change material at different discharge rates and different ambient temperatures
No full textBatteries are one of the most important systems in electric vehicles. The performance of batteries varies depending on temperature, and high battery temperatures reduce battery efficiency and life. In recent years, intensive studies have been carried out on passive systems to prevent the battery module from heating, and many studies have been conducted especially on the use of phase change material (PCM). In this study, a novel battery module design created using PCM is tested by setting up experimental setups at both different discharge rates and different ambient temperatures, and the cooling performance of PCM is examined. As a result, it was found that the temperature increase in the PCM decreases during the melting process and the increase in the battery surface temperature varies according to the current value of the total heat generated in the battery. If the total heat generated in the battery increases, both the battery surface temperature and the temperature rise rate increase; if the total heat generated in the battery is constant or decreasing, the battery surface temperature increases but the temperature rise rate decreases.Scientific and Technological Research Council of Turkiye (TUBITAK)Open access funding provided by the Scientific and Technological Research Council of Turkiye (TUBITAK)