Örnek bir alüminyum ekstrüzyon imalat tesisinde enerji verimliliğinin incelenmesi

06.03.2018 tarihli ve 30352 sayılı Resmi Gazetede yayımlanan “Yükseköğretim Kanunu İle Bazı Kanun Ve Kanun Hükmünde Kararnamelerde Değişiklik Yapılması Hakkında Kanun” ile 18.06.2018 tarihli “Lisansüstü Tezlerin Elektronik Ortamda Toplanması, Düzenlenmesi ve Erişime Açılmasına İlişkin Yönerge” gereğince tam metin erişime açılmıştır.Bu çalışmada, ekstrüzyonla Alüminyum üretimi yapan tesislerde üretim kalitesi ve miktarının düşüşüne yol açmadan enerji verimliliğinin sağlanması, ısı transferinde kayıpların en aza indirgenerek yüksek verimin elde edilmesi ve tesislerde önemli bir maliyet unsuru haline gelen enerji talebinin azaltılması amaçlanmıştır. Bu amaç doğrultusunda mevcut olan ve ısı kaybına neden olan makinalar belirlenmiştir. Belirlenen her bir makina için termal kamera ile ölçümler yapılmıştır. Termal kamera ile elde edilen sonuçlar programa işlenerek ısı kaybına neden olan kısımlar tespit edilip, ısı kaybının gerçekleştiği yere bağlı olarak çeşitli izolasyon ve mekanik tamir önerilerinde bulunulmuştur. Öneriler doğrultusunda yapılan revize çalışmaları sonrası tekrar ölçümler yapılmıştır. Revize öncesi ve revize sonrası olacak şekilde tüm makinalar için enerji kayıpları hesaplanmış ve durumlar arasındaki enerji tasarrufu belirlenmiştir. Mekanik tamir ve izolasyon için yapılan revize maliyetleri hesaplanmıştır. Revize maliyetleri ile makinanın ısı kaybının engellenmesiyle oluşan ekonomik girdi karşılaştırılıp, revize maliyetlerinin her makina için kendini ne kadar sürede amorti edeceği hesaplanmıştır. Ayrıca revize önerileri gerçekleştirilmeyen makinalar için de tekrar ölçüm gerçekleştirilmiştir. Yapılan ölçümler sonucunda makinaların iki ölçüm arasındaki sürede ne kadar enerji kaybı yaşadığı belirlenmiştir. Çalışmada elde edilen sonuçlara göre enerji verimliliği için revize yapılması önerilen makinalarda varan 33240,5 kWh/Ay'lık ısı kayıpları ve buna tekabul eden 8510 TL/Ay'lık maliyet engellenmiştir.Aim of this study was to achieve the highest possible heat energy efficiency and to decrease the total energy demand without any decrease in the production quality and quantity in Aluminum extrusion facilities. For this purpose, machines with the highest heat loss were determined. Measurements were made via a thermal camera for each machine. The results obtained by the thermal camera were processed in a software and the parts causing heat loss were detected. Various isolation and mechanical repair suggestions were made depending on the location of the heat loss. After the revisions made in accordance with the recommendations, thermal camera measurements were repeated. The energy losses for all machines were calculated before and after the revisions and the ultimate energy saving obtained after revisions were determined. Revision costs for mechanical repair and isolation were also calculated. The economic input caused by the heat loss of each machine were compared to the revision costs to determine the pay-off period of each revision. In addition, measurements were also performed for machines that did not undergo any revision to calculate the amount of the energy loss experienced the two measurements in these machines. According to the results obtained in the study, 33240,5 kWh / Month heat losses and the corresponding cost of 8510 TL / Month were prevented in the machines revised for increased energy efficiency

Selective Laser Sintering of Aluminum Extrusion Dies

In this study, geometric forms of maraging steel dies used in aluminum extrusion were optimized by means of flow dynamics as well as surface quality and mechanical properties of the final part. Maraging steel (MS1) dies were produced by Direct Metal Laser Sintering (DMLS), a Selective Laser Sintering (SLS) method, using EOS M290. Dies were not subjected to any conventional finishing post processes. Field tests were carried out in an industrial aluminum extrusion facility. Results presented that DMLS is a promising method for the production of dies with complex inner sections with high accuracy, high speed and low cost. Production of high quality extruded profiles was possible using additive manufactured dies directly from production without applying any finishing post process

Unmanned Aerial Vehicle Production with Additive Manufacturing

In this study, unmanned aerial vehicle (UAV) design, analysis and production was made using selective laser sintering (SLS) system. Four different aircraft bodies were designed in the interdisciplinary project, one of the models was selected by comparing the computational fluid dynamics (CFD) analysis results. According to the numerical study, the model 4 design was found to be the most suitable among the tested models, then the design was produced with the SLS system. Finally, the actual flight test was carried out in three different weather conditions, and the results are presented here

Improving the Surface Quality and Mechanical Properties of Selective Laser Sintered PA2200 Components by the Vibratory Surface Finishing Process

This paper attempts to improve the physical and mechanical properties of selective laser sintered polyamide PA2200 components through a vibratory surface finishing process by inducing severe plastic deformation at the outer surface layers. The industrial target of additive manufacturing components is to obtain structures having surface roughness, hardness, and other mechanical properties equivalent to or better than those produced conventionally. Compared to the as-built SLS PA2200 samples, vibratory surface finishing treated specimens exhibited a smooth surface microstructure and more favorable roughness, hardness, and tensile strength. Also, the duration of the vibratory surface finishing process showed a further improvement in the surface roughness and hardness of the SLS samples. Compared to the asbuilt state, the roughness and hardness of the surface-treated samples improved by almost 90% and 15%, respectively. Consequently, microstructural analysis indicates that lower surface roughness and enhanced surface hardness is a crucial factor in influencing the overall tensile strength of SLS-PA2200 components. We consider that the combination of VSF and SLS processes can successfully handle a wide range of potential applications. This study also highlights the efficiency and applicability of the vibratory surface finishing process to other additive manufacturing processes and materials

Halkımızın teratoloji hakkındaki farkındalığı

Amaç: Bu çalışma ile çevresel etkenlerden kaynaklanan doğumsal bozuklukları ve anormal prenatal gelişmeyi inceleyen ve doğumsal defektleri önlemenin araştırmalarını yapan bilim dalı olan teratoloji hakkında halkımızın neler bildiğini ve konu ile ilgili farkındalıklarını araştırmayı amaçladık. Gereç ve Yöntem: Selçuk Üniversitesi Tıp Fakültesi Hastanesi’ne sağlık hizmeti almak üzere başvuran hasta ve hasta yakınlarından oluşan, yaşları 18 - 79 arasında değişen, eşit sayıda kadın ve erkekten oluşan toplam 400 katılımcıya anket uygulaması yapıldı. Elde edilen veriler ortalama ± standart sapma ve yüzde olarak özetlendi. Bulgular ve Sonuç: Yapılan anket çalışmasında homojen olmayan sonuçlar elde edildi. Bu verilere göre katılımcıların ölü ya da sakat doğumların sebepleri, röntgen, tomografi vb. kullanımının anne karnındaki bebeğe etkileri, ilaçların yan etkilerine dikkat etme, akrabalık derecesinin hastalıklı doğumlara etkisi konularında belirli düzeyde fikir sahibi oldukları saptandı. Anne karnındaki bebeğin hastalıklara karşı en duyarlı olduğu gebelik dönemi hakkında ise yeterli bilgi düzeyine sahip olmadıkları belirlend

The evaluation of vitamin K status in children with febrile seizure

Background: Febrile seizure is the most common neurological disorder in childhood. The exact pathophysiology of febrile seizures is unknown. Recent studies showed the role of vitamin K in nonhematological and inflammatory disorders. This study aimed to investigate the serum vitamin K levels in children with febrile seizures. Aims: To evaluate vitamin K levels in children with febrile seizures. Study Design: Prospective case-control study. Methods: This multicenter study examined representative populations in 8 different cities in Turkey between April 1, 2018 and April 1, 2019. Blood samples were taken from all children at presentation. Vitamin K1, vitamin K2, tumor necrosis factor-alpha, interleukin 1 beta, and interleukin 6 levels were determined by enzyme-linked immunosorbent assay. Results: A total of 155 children were included in the study—84 children with febrile seizures and 71 children in febrile control group. Serum vitamin K1 and vitamin K2 levels were also higher in children with febrile seizures than in the controls. The results of statistical analysis showed that vitamin K1 and vitamin K2 levels were correlated with tumor necrosis factor-alpha, interleukin 1 beta, and interleukin 6 levels. The median vitamin K1 and vitamin K2 levels of children experiencing their first febrile seizure were higher than those in children with recurrent febrile seizures. Type of febrile seizure has no effect on serum vitamin K1 and vitamin K2 levels. Conclusion: In children with febrile seizures, vitamin K levels are higher than those in the control group. These new findings may contribute to elucidating the etiopathogenesis of febrile seizures

Children in 2077: Designing Children’s Technologies in the Age of Transhumanism

What for and how will we design children’s technologies in the transhumanism age, and what stance will we take as designers? This paper aims to answer this question with 13 fictional abstracts from sixteen authors of different countries, institutions and disciplines. Transhumanist thinking envisions enhancing human body and mind by blending human biology with technological augmentations. Fundamentally, it seeks to improve the human species, yet the impacts of such movement are unknown and the implications on children’s lives and technologies were not explored deeply. In an age, where technologies can clearly be defined as transhumanist, such as under-skin chips or brain-machine interfaces, our aim is to reveal probable pitfalls and benefits of those technologies on children’s’ lives by using the power of design fiction

Thermo‑Mechanical Simulations of Selective Laser Melting for AlSi10Mg Alloy to Predict the Part‑scale Deformations

Abstract Selective laser melting (SLM) is one of the most frequently employed metal additive manufacturing methods. Various industries such as aerospace, automotive, biomedical, and tooling utilize SLM parts. Although it has a wide scope of applications, it demands a thorough understanding to supply reliable parts. Thus, process simulations are key methods to optimize the process and to shorten the product development time. SLM allows manufacturing of steel, nickel, cobalt, chromium, titanium, and aluminum alloy parts. Aluminum alloys are one of the most common materials processed in the manufacturing industry, and AlSi10Mg is one of the SLM-compatible alloys which requires further understanding. This study focuses on AlSi10Mg alloy SLM simulations to predict the part deformations accurately. The proposed material properties of cast AlSi10Mg alloy simulations closely agreed with the experimental results, and this specific model is expected to aid design engineers to fabricate their parts with better consistency