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Green Synthesis of Silver Nanoparticles Mediated by Cinnamon Extract and Its Potential Insecticidal Effect Against Callosobruchus Maculatus (F.) (Coleoptera: Chrysomelidae)
No full textSilver nanoparticles were successfully synthesized using cinnamon extract as a reducing agent. The synthesized nanoparticles, coated with cinnamon extract, were characterized through various optical and spectroscopic techniques. UV-visible spectroscopy confirmed the formation of cinnamon-extract-coated silver nanoparticles (Cinnamon-AgNPs) by optimizing parameters such as precursor salt concentration, pH, temperature and extract volume. The crystalline structure of the nanoparticles was examined using X-ray diffraction (XRD), while size distribution was analyzed through transmission electron microscopy (TEM). It was observed that cinnamon extract effectively stabilized silver nanoparticles and the average particle size was 23.3 nm, with a near-spherical shape. Advances in nanotechnology have recently offered novel approaches in plant protection strategies. The increasing resistance of stored-product pests like Callosobruchus maculatus to conventional insecticides necessitates the exploration of eco-friendly alternatives. In this study, the insecticidal activity of silver nanoparticles coated with cinnamon extract was evaluated against the adult stage of Callosobruchus maculatus. Additionally, the aqueous extract of cinnamon was also evaluated. Toxicity assays were conducted at varying concentrations of the nanoparticles and cinnamon extract, with exposure durations of 24, 48, and 72 hours. The results revealed that cinnamon-extract-coated silver nanoparticles exhibited the highest toxic effect at the highest concentration after 72 hours (60.72%). In contrast, the aqueous extract of cinnamon did not exhibit a significant toxic effect on C. maculatus. This significant difference highlights the synergistic insecticidal effect of the combination of silver nanoparticles and cinnamon extract. Overall, the findings highlight the significant potential of cinnamon-extract-mediated silver nanoparticles as an effective insecticidal agent against Callosobruchus maculatus
Beacon Mesafe Değerlerinin Ortam Koşullarına Göre Polinom Enterpolasyonu ve Yapay Sinir Ağlarıyla Belirlenmesi
No full textBluetooth alt yapısına sahip olan, tek bir tuşla açılıp kapatılabilen, küçük boyutlu ve taşınabilen, düşük enerji ile uzun süreler çalışabilen Beacon cihazları son yıllarda oldukça popüler hale geldi. Tanıtım ve konum bazlı projeler başta olmak üzere birçok alanda kullanılmaktadır. Özellikle Beacon’lar tarafından gönderilen Bluetooth sinyallerinin gücündeki değişimden yararlanılarak Beacon cihazı ile kullanıcı arasındaki mesafe belirlenebilmektedir. Bu mesafe bilgisi ise konumlandırma algoritmalarında temel parametre olarak kullanılmaktadır. Beacon üreticisi firmalar tarafından, standart ortam koşulları ile elde edilen veriler kullanılarak Beacon ile kullanıcı arasındaki mesafe otomatik olarak kullanıcılara sunulmaktadır. Kullanıcı bu mesafeyi ortam koşullarına göre kendi oluşturduğu verileri kullanarak da hesaplayabilmektedir. Bu çalışmada kapalı bir alanda Beacon’lardan gelen Bluetooth sinyalleri kaydedilerek ortam koşullarına göre Beacon ile kullanıcı arasındaki mesafe polinom enterpolasyonu ve yapay sinir ağları yöntemleriyle hesaplanmıştır. Elde edilen sonuçlar, Beacon’lar tarafından kullanıcıya otomatik olarak sunulan mesafe bilgisi ile karşılaştırılmıştır. Çalışmada en iyi sonucu, Beacon’lardan otomatik olarak alınan mesafe bilgisinden 1.21m daha iyi sonuç veren 10. dereceden polinom enterpolasyonu sağlamıştır
Fruit Peel Incorporated Alginate Based Magnetic Hydrogel Bio-Composite Beads for Removal of Hexavalent Chromium
No full textHigh adsorption capacity, reusability and sustainability are the most important features sought in the adsorbent preferences to be used in wastewater treatment. In this research work, magnetic composite beads prepared from fruit peels (nectarine and orange) and alginate (ALG) as biopolymers (NAF and OAF) were synthesized by dropping and pH-precipitation method as alternative adsorbents. By encapsulating the adsorbent using alginate and imparting magnetic properties, the separation of the adsorbent from water after the adsorption process has been simplified. Fourier transform infrared spectroscopy analysis (FTIR), scanning electron microscopy (SEM) analysis, energy-dispersive X-ray (EDX)-mapping and X-ray diffraction (XRD) analyses were performed to examine the surface chemical structure and surface morphological structure of these new synthesized biosorbents. The calculated maximum adsorption capacities were 224.3 mg/g for OAF and 256.5 mg/g for NAF at 298 K and pH =2.0. It was observed that the adsorption process for both adsorbents was endothermic and spontaneous. Moreover, the adsorptions of Cr (VI) onto both adsorbents followed the pseudo-second order model and fit the Langmuir isotherm model better. OAF and NAF were found to be reusable with stable adsorption capacity for at least five cycles. Overall, this study demonstrates the performance of OAF and NAF in the removal of Cr (VI) ions from aqueous solutions, thus highlighting the promising potential of these magnetic bio-based adsorbents for sustainable water treatment.This research study was financially supported by Konya Technical University Scientific Research Coordinating Office (Project Number:Konya Technical University Scientific Research Coordinating Offic
Influences of Various Thermoplastic Veil Interleaves Upon Carbon Fiber-Reinforced Composites Subjected To Low-Velocity Impact
No full textThroughout their service life, composite materials may be subjected to impact loads, which can result in some damage mechanisms that cause degradation in mechanical and dynamic responses. Especially matrix-induced cracks and delamination can have significant effects on the final properties, and cause serious problems if the necessary precautions are not taken. In the current study, Carbon Fiber-Reinforced Polymer (CFRP) composites interleaved with Fine Glass (FG), Polyetherimide (PEI), Polyetheretherketone (PEEK), Polyimide (PI) and Poly-Phenylene Sulphide (PPS) thermoplastic veils were fabricated, and exposed to LVI tests under 25.2 J constant impact energy to determine how veils affect the dynamic properties. The selected veils are commercially available materials and are used for various purposes. In this regard, it was aimed to examine the usability of these commercially available veils as interlayers and to examine the impacts of the veils used as interlayers on the LVI characteristic of CFRP composites. According to the present study, it was found that veil interleaves significantly affect the composite stiffness, and accordingly, relevant LVI responses such as total impulse, bending stiffness, interaction times etc. For instance, approximately 21.2% reduction in the peak displacement and 73.23% increment in the bending stiffness were observed due to FG veil interleaves. On the other hand, when the effects of veil types were examined, the maximum and minimum variations in the LVI responses were observed for the FG and PEI interleaves, respectively, and FG veils were found to be the most effective veil types for the CFRP composites. It was also revealed that veil interleaves strengthen the interlaminar region between plies and delamination resistance, and thereby improved the Delamination Threshold Loads for all configurations. © The Author(s) 2024.Atatürk Üniversitesi; Bilimsel Araştırma Projeleri Birimi, İstanbul Teknik Üniversitesi, BAP, (FBA-2021-9447); Bilimsel Araştırma Projeleri Birimi, İstanbul Teknik Üniversitesi, BAP; Bingöl Üniversitesi, (BAP-MMF.2021.002); Bingöl Üniversites
Aısı 4340 Çeliklere Uygulanan Nitrasyon İşleminin Boyut ve Geometrik Toleransına Etkisinin Araştırılması
No full textThe AISI 4340 quenched and tempered steel is widely used in various industries, such as aerospace, automotive, and defense, due to its high strength, toughness, and wear resistance properties. Nitriding surface hardening processes plays a significant role in increasing the surface hardness of this material, enhancing its wear resistance, and improving its fatigue strength. However, dimensional and geometric changes that occur during the nitriding process can adversely affect systems operating with precise tolerances. In this study, the effects of the nitriding process applied to AISI 4340 steel on part dimensions, geometric tolerances, surface roughness, surface hardness, diffusion depth, and white layer thickness were examined. A total of 18 samples with three different geometric forms were used in the research. Six hours of nitriding was applied to three samples from each geometry, while 12 hours of nitriding was applied to the other three samples. Measurements conducted on the parts revealed dimensional changes ranging from 3.5 to 6 µm for the 6-hour nitriding process and from 15 to 19 µm for the 12-hour nitriding process. It was found that these changes caused most tolerance grades in the IT5 to IT9 range to fall out of tolerance or reduced tolerance grades to values below 10 µm, making manufacturing more challenging. While the nitriding process negatively affected symmetry tolerance, it did not affect parallelism or concentricity tolerances. As the nitriding duration increased, surface hardness decreased; however, the increase in nitriding duration also led to an increase in diffusion depth and white layer thickness.AISI 4340 ıslah çeliği, yüksek mukavemet, tokluk ve aşınma direnci özellikleri sayesinde havacılık, otomotiv ve savunma sanayi gibi birçok sektörde yaygın olarak kullanılmaktadır. Bu malzemenin yüzey sertliğini artırmak, aşınma direncini yükseltmek ve yorulma dayanımını iyileştirmek için nitrasyon yüzey sertleştirme işlemi önemli bir rol oynamaktadır. Ancak, nitrasyon işlemi sırasında boyutsal ve geometrik değişimlerin oluşması, hassas toleranslarla çalışan sistemlerde olumsuz etkiler oluşturabilmektedir. Bu çalışmada, AISI 4340 çeliklerine uygulanan nitrasyon işleminin, parçaların boyut, geometrik tolerans, yüzey pürüzlülüğü, yüzey sertliği ve difüzyon derinliği ile beyaz tabaka kalınlığına etkileri incelenmiştir. Araştırmada, üç farklı geometrik forma sahip toplam 18 adet numune kullanılmıştır. Her bir geometriden üç numuneye 6 saat, diğer üç numuneye ise 12 saat nitrasyon işlemi uygulanmıştır. Parçalar üzerinde yapılan ölçümler neticesinde boyut toleransında 6 saatlik nitrasyon işleminde 3,5 ila 6 µm aralığında, 12 saatlik nitrasyon işleminde ise 15 ila 19 µm aralığında değişim meydana gelmiştir. Bu değişimin IT5 ve IT9 aralığındaki tolerans derecelerinden çoğunda tolerans dışına çıkılmasına neden olduğu veya tolerans derecelerini değer olarak 10 µm'nin altına düşürerek imalatı zorlaştırdığı bulunmuştur. Nitrasyon işlemi simetriklik toleransını olumsuz yönde etkilerken, paralellik ve eş merkezlilik toleransına etki etmemiştir. Nitrasyon süresi arttıkça yüzey sertliğinin azaldığı görülürken nitrasyon süresinin artması difüzyon derinliğini ve beyaz tabaka kalınlığını artırmıştır
Highly Efficient Hexavalent Chromium Removal Using Nano-Fe3O4/Pomegranate Peel Biochar/Alginate Composite as an Advanced Biosorbent
No full textBu çalışmada, yeni bir kompozit – nano-Fe₃O₄/nar kabuğu biyokömür/aljinat hidrojel boncukları (nFe₃O₄-PPBC/Alg) – sulu çözeltilerden Cr(VI) iyonlarının uzaklaştırılması için alternatif bir adsorban olarak sentezlendi. Adsorban malzeme, FT-IR analizi ve taramalı elektron mikroskobu (SEM) kullanılarak karakterize edildi. Cr (VI) giderme verimlilikleri, optimal pH, adsorban dozu, temas süresi ve başlangıç konsantrasyonunu belirlemek için standart kesikli kap adsorpsiyon yöntemi kullanılarak hesaplandı. Dengedeki adsorpsiyon davranışını tanımlamak için Freundlich, Langmuir ve Dubinin-Radushkevich gibi çeşitli adsorpsiyon izotermleri kullanıldı. Langmuir adsorpsiyon izoterminin, gözlenen adsorpsiyon fenomenini tanımlamak için en uygun olduğu bulundu ve nFe₃O₄-PPBC/Alg adsorpsiyon kapasitesi Cr (VI) için 303.03 mg/g olarak belirlendi. nFe₃O₄-PPBC/Alg üzerindeki adsorpsiyon süreçlerini araştırmak için, sözde birinci dereceden ve sözde ikinci dereceden modeller dahil olmak üzere kinetik modeller uygulandı. Sözde ikinci dereceden kinetik model, deneysel verilere en iyi uyumu sağladı. Bu çalışma, nFe₃O₄-PPBC/Alg'nin sulu çözeltilerden Cr (VI)'nın uzaklaştırılması için etkili bir adsorban olduğunu göstermiştir
Fındık Atıklarından Hidrokömür Üretimi ve Atık Sudan Ağır Metal İyonlarının Giderilmesinde Kullanımı
No full textAğır metallerin ekosistem boyunca yayılması insan sağlığı başta olmak üzere, hayvanlar, bitkiler ve doğal kaynaklar için oldukça tehlikelidir. Bu nedenle ağır metal iyonunun atık sulardan en etkin şekilde uzaklaştırılması önem arz etmektedir. Bu tür kirleticileri ortadan kaldırmak veya azaltmak için çok sayıda çalışma yapılmıştır ve yapılmaya da devam etmektedir. Hidrokömür, su ve atık sudan ağır metallerin uzaklaştırılması için umut verici bir adsorban olarak ortaya çıkmıştır. Biyokütlenin hidrotermal karbonizasyonundan elde edilen hidrokömür, yüzey kompleksleşmesi, elektrostatik etkileşimler ve iyon değişim mekanizmaları yoluyla ağır metalleri yakalamada oldukça etkili olan benzersiz fiziksel ve kimyasal özelliklere sahiptir. Bu çalışmada fındık atığından hidrokömür üretilmiş ve üretilen bu adsorbanla Pb ve Cr iyonlarının giderim çalışmaları yapılmıştır. Bu şekilde hem fındık kabuğu atığının değerlendirilmesi sağlanmış hem de çevre için çok zararlı olan ağır metallerin giderimi sağlanmıştır. Üretilen hidrokömürlerin yapısal ve morfolojik özellikleri; TGA, DSC, FE-SEM, FT-IR ve EDX analizleri ile karakterize edilmiştir. Başlangıç konsantrasyonu, sıcaklık özellikleri, adsorban dozajları, temas süresi ve pH gibi birçok parametrenin adsorpsiyon üzerindeki etkileri tartışılmıştır. Farklı parametre ortamlarında yapılan çalışmalarda hidrokömürün, Pb ve Cr iyonlarının sırasıyla %76' sını ve %67' sini giderdiği belirlenmiştir. Ayrıca, üretilen hidrokömürün adsorpsiyon sistemini daha iyi anlamak için Langmuir ve Freundlich izoterm modelleri, pseudo-birinci mertebe ve pseudo-ikinci mertebe kinetik modelleri ve Gibbs serbest enerjisi gibi termodinamik parametreler araştırılmıştır. Ayrıca, hidrokömürün bir adsorban olarak yeniden kullanılabilirliği araştırılmış ve malzemenin dört döngüden sonra bile etkili bir şekilde çalışmaya devam ettiği gözlemlenmiştir.The spread of heavy metals throughout the ecosystem is quite dangerous for human health, animals, plants and natural resources. Therefore, it is important to remove heavy metal ions from wastewater in the most effective way. Numerous studies have been conducted and continue to be conducted to eliminate or reduce such pollutants. Hydrochar has emerged as a promising adsorbent for the removal of heavy metals from water and wastewater. Hydrochar, obtained from hydrothermal carbonization of biomass, has unique physical and chemical properties that are highly effective in capturing heavy metals through surface complexation, electrostatic interactions and ion exchange mechanisms. In this study, hydrochar was produced from hazelnut waste, and Pb and Cr ion removal research was conducted with this adsorbent. In this way, both the evaluation of hazelnut waste was provided and the removal of heavy metals, which are very harmful for the environment. The structural and morphological properties of the produced hydrochars were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), field emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FT-IR), and EDX analyses. The effects of many parameters, such as initial concentration, temperature, adsorbent dosages, contact time, and pH on adsorption were discussed. In the studies executed in different parameter environments, it was determined that hydrochar removed 76% and 67% of Pb and Cr ions, respectively. Also, Langmuir and Freundlich isotherm models, pseudo-first-order and pseudo-second-order kinetic models, and thermodynamic parameters like Gibbs free energy were investigated in order to gain a better understanding of the adsorption system of the generated hydrochar. Furthermore, the hydrochar' s reusability as an adsorbent was investigated, and it was demonstrated that the material continued to function effectively even after four cycles
The Phenomenology of Space in Wim Wenders' Perfect Days: a Dialogue Between Architecture and Cinema
No full textWim Wenders' Perfect Days explores the intersection of cinema and architecture through a phenomenological lens. The film examines public restrooms in Tokyo, each with unique architectural characteristics, delving into how these spaces are perceived and how they enhance the viewer's spatial experience. In the film, spaces transcend their traditional role as mere backdrops to become central components of the narrative. The restrooms featured in the film stand out as significant elements that shape individuals' sensory awareness, social contexts, and personal experiences from both architectural and phenomenological viewpoints. Architectural design integrates phenomenological qualities of space, such as the interplay of light, shadow, sound, and textures, enriching the viewer's experience of these locations. This study investigates how these restrooms are conveyed to the audience through the film's structure and narrative and how they shape sensory and emotional experiences. Qualitative research methods were employed, using document analysis and content analysis to frame the conceptual foundation of the study. It was found that these spaces form layers of both individual and collective meaning through their design elements and relationships with the urban context. The study demonstrates how the concept of phenomenological space can be interpreted through cinema
Elements of a Digital Urbanisation Strategy for Türkiye: Evidence From Psychometric Testing
No full textThe research aims to explore the key components of an ideal grassroots-based digital urbanisation strategy for T ; uuml;rkiye. This exploration seeks to shed light on the most effective digital urbanisation strategies for T ; uuml;rkiye. Data were collected through a literature review, in-depth interviews with experts and psychometric testing methods, and analysed through psychometric assessment and document content analysis. The research indicates that an ideal grassroots-based digital urbanism strategy for T ; uuml;rkiye should focus on people, use technology to ease everyday activities, maintain personal data privacy, be adaptable, encourage diversity, provide freedom and opportunities, protect the city's heritage, and strive for sustainability. By aligning with these essential elements, revisiting the national strategy documents crafted by the Turkish authorities to enhance the digitalisation process will allow future action plans to be grounded in a more practical framework.The paper was produced from Kuebra CAY's Master's Thesis titled "Possible Changes in the Relationship of Turkish Society with Space in the Transition to Digital Society: A Social Tendency Survey" conducted at Konya Technical University Institute of Graduate Studies under the academic supervision of Assoc.Prof.Dr. Fatih EREN. This MSc thesis was financially supported by the Scientific Research Projects Coordinatorship of Konya Technical University with the project numbered 191021029. In addition, the theoretical framework of this paper has been produced by utilizing the scientific research project titled "The spatiality of Istanbul city from the eyes of a digital platform" conducted under the code MAB-2023-44885 at Istanbul Technical University, with Assoc.Prof.Dr. Fatih Eren as the project manager. The funding sources had no role (were not involved) in the production of this paper.Scientific Research Projects Coordinatorship of Konya Technical University [191021029
Investigation of Physical and Mechanical Properties of Polymer Based Composite Material Using Volcanic Tuff Dust in Cappadocia, Turkey
No full textCappadocia is not only a region of Turkey with historical and touristic importance. During the cutting and processing of volcanic tuff, quarries in this region release large amounts of tuff into the environment that is viewed as waste. The release of this waste constitutes an economic loss and contributes to environmental pollution. However, through experimentation with deformation, weight per unit of volume, water absorption, uniaxial compression strength, modulus of elasticity, and point load strength index, volcanic tuff and marble dust composite materials can be produced for use in the building sector. In this study it was observed that, as the percentage of volcanic tuff dust in the mixture increased, the water absorption rate of the material increased, and uniaxial compression strength and point load strength decreased. The produced composite samples used in this study were kept for a predetermined number of times per day, and no deformation in the surface characteristics of the materials was observed. In a statistical parameter analysis, averages, variances, standard deviations, coefficients of variation, and skewness coefficients were calculated. Covariance changes between experimental parameters were also determined. In this study, two types of volcanic tuff dust, that is, yellow and red, were produced during the production of tuff-marble dust composite material. When the percentage of either type of volcanic tuff dust was increased, an increase in water absorption was observed. It was also observed that when the percentage of volcanic tuff dust was increased, uniaxial compressive strength and point load strength decreased. Furthermore, the physical and mechanical properties of the materials obtained by mixing different colored tuff powders and marble powders in different proportions were evaluated using statistical parameter analysis