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Intersektionale kommunikation: Zur differenz von interpersonaler kommunikation und intergruppenkommunikation am Beispiel von altersgrenzen
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Solar–Hydrogen Coupling Hybrid Systems for Green Energy
No full textGreen hydrogen production coupled with solar energy became a universal concept to provide more efficient energy caring for the environment within the 2030 sustainable development goals target. The green energy concept provides energy systems without negative impact on the environment, economy, and society. At this point, hydrogen became a suitable energy and energy carrier for the green to green (G2G) concept, which evaluates green resources and green systems together. Producing hydrogen energy using solar radiation lowers greenhouse emissions. It allows people to participate in environmental improvements actively, makes the energy supplied cycles more sustainable, and protects the right to life of future generations. Solar energy is a primer source that can be directly adapted to provide steady power for the G2G system. Nowadays, recent trends on fuel cell, electrolyzer, and photovoltaic and photoelectrochemical technology within solar energy systems as a hybrid combination have a critical approach to realize G2G systems based on hydrogen and solar energy. This chapter focuses on G2G system, the combination of solar energy – hydrogen, fundamentals on electrolysis, photovoltaic panel, fuel cell, and electrolyzer or their hybrid combinations used for green hydrogen production from solar energy; also, thermochemical, photobiological, and photoelectrochemical production methods have been briefly introduced compared and outlined the future remarks
Dijital dönüşüm ve yönetimi
No full textİşletmelerin tüm yapı ve süreçlerini gözden geçirmelerini sağlayan dijitalleşme ve dijital dönüşüm sürecini farklı boyutlarıyla ele alma amacıyla ortaya çıkmıştır. Ülkemizin birbirinden güzide on iki farklı üniversitesinden, alanlarında ve özellikle dijitalleşme ile dijital dönüşüm konularında yetkin on dört bilim insanının imzasını attığı eserde; dijitalleşme ve dijital dönüşümün temelleri, e-iş ve akıllı işletmeler, dijital dönüşüm ve yönetimi, dijital dönüşümün işletme yapı ve süreçlerine yansımaları arasında yer alan DAO'lar, dijital liderlik, dijital girişimcilik ve dijital sermaye kavramları ile değişen çalışma yaşamı bağlamında dijital insan kaynakları yönetimi, dijital kariyer ve yönetimi, dijital çalışma şekilleri, çalışma yaşamının geleceği, diğer yandan dijital olgunluk ve sürdürülebilirlik, siber güvenlik ve son olarak eleştirel yönetim çalışmaları perspektifinden dijitalleşme başlıkları ele alınmıştır. Eserin; işletme ve yönetim organizasyon literatürüne, lisans ve lisansüstü düzeyinde eğitim gören öğrencilere, kamu ve özel sektör temsilci ve yöneticilerine ve konuya ilgi duyan okuyucularına faydalı olması umulmaktadır
Additive manufacturing with metallic powder materials-development of a strategic material qualification methodology for electron beam powder bed fusion
Get PDFSince the maturity level of the metal powder bed fusion (PBF) additive manufacturing (AM) technologies have already become suitable to produce complex net shape parts, the need for metal powders in AM industry is increasing in different sectors. In recent years, the main concentration of efforts in the research of advanced materials is on reaching full or near full density geometries with good dimensional stability and tight tolerances while tailoring the required properties by controlling the microstructure. Using metallic powders for part production by AM has the benefits such as greater design flexibility in comparison to conventional casting and machining, and less raw material consumption due to aiming net shape which is crucial for expensive or hard-to-machine metal alloys. Qualification is a technique to make sure that an additive manufacturing process is monitored and that the end product satisfies criteria in a repeatable way. The material is essential in this qualification process, as its chemical and physical properties can directly influence the manufactured part. Qualifying a material for AM requires a methodology that is strategically developed to evaluate all the variables that can affect the quality of the parts needed as well as the reliability and reproducibility of the process. Since the expiration of the patent in the electron beam powder bed fusion bed (PBF-EB/M) process, new machine manufacturers entered the market. However, the “off the shelf” qualified materials from these manufacturers and third parties are limited. Now, some titanium, nickel, steel, and copper alloys are available. This shows that there is a need for a strategic methodology for faster material qualification for newly developed materials to use PBF-EB/M widely. Therefore, this work aims to develop a methodology that delivers an efficient qualification for new and existing materials. Within the framework of this thesis, by combining the performed literature search and usage of the existing know-how at the chair of Hybrid Additive Manufacturing at Ruhr University Bochum, a strategic material qualification methodology is successfully developed for the PBF EB/M process. The developed methodology considers the material qualification procedure in 3 main topics. First, the properties of the powder material are investigated and their relationship with the bulk powder behavior and in-process performance are defined from the literature. Then, required powder characterization techniques are investigated and their use cases are shown based on standards and the literature. Secondly, the main challenge powder spreading effect in PBF-EB/M is investigated. The possible reasons and suppression methods for such an effect are identified from the literature. Accordingly, some testing techniques both from in house developed and literature are recommended, and their application steps are explained in detail. Finally, the exposure phase is considered and the influencing factors for the exposure phase are identified based on the fabricated part quality requirements. Based on this knowledge, process parameter identification methods, and recommended testing and evaluation techniques for fabricated part assessment are shown. The developed methodology is then validated using AlSi10Mg aluminum alloy. For that, several tests are performed at each step and the results are evaluated and documented. The results showed that by applying the strategically developed qualification methodology steps, the required process parameters for a stable running process, and high-quality parts can be obtained. For instance, the fabricated parts with over 99,5 % relative density and below 100 µm surface roughness and waviness could be achieved. Based on the industrial application, these results satisfy the need
Investigating the effects of post-mold cure on warpage in electronic packaging processes
No full textPost-mold Cure ist ein häufig angewandtes Verfahren im Bereich Electronic Packaging, bei dem duromere Teile nach der Formgebung erneut erhöhten Temperaturen ausgesetzt werden, um eine höhere Vernetzungsdichte und damit bessere Materialeigenschaften zu erreichen. Bisherige Studien und industrielle Anwendungen haben gezeigt, dass der Post-mold Cure auch eine nützliche Methode ist, um den Verwölbung der Verkapselung, der ein wichtiges Qualitätskriterium ist, zu verringern. Trotz dieser Erkenntnisse sind die Auswirkungen verschiedener Post-mold Cure Parameter auf die resultierende Verwölbung noch immer nicht genau bekannt, da der Post-mold Cure meist mit denselben Parametern durchgeführt wird. Das Ziel ist hierbei eine möglichst hohe Vernetzungsdichte zu erreichen, ohne die Verwölbung genau zu berücksichtigen. In dieser Arbeit werden die Auswirkungen des Post-mold Cures auf die Verwölbung der verwendeten Prüfkörper untersucht. Materialcharakterisierungstests werden durchgeführt, um das Wärme- und Aushärtungsverhalten der Materialen zu untersuchen. Experimente mit unterschiedlichen Post-mold Cure Temperaturen und Zeiten werden durchgeführt, um diese Parameter mit der resultierenden Verwölbung zu korrelieren und ein Prozesswissen zu generieren. Die Verwölbung der Prüfkörper wird durch optische 3D-Profilometerscans bewertet. Es werden außerdem Infrarotspektren der Materialien gemessen, um die Veränderungen der chemischen Zusammensetzung des Epoxidharzes während des Post-Mold Cures als Indikator für Änderungen in der Vernetzungsdichte zu verwenden. Anhand der Experimente wird der Mechanismus zur Verringerung der Verwölbung während des Post-mold Cures erklärt und mit der thermischen und chemischen Schrumpfung, sowie dem Glasübergangsverhalten der Materialien in Verbindung gebracht. Darüber hinaus werden die gewonnenen experimentellen Daten verwendet, um einen Machine Learning Algorithmus aufzusetzen, der die optimalen Post-mold Cure Parameter vorhersagt, die am Ende die gewünschte Verwölbung und Vernetzungsdichte ergeben. Mit Hilfe des Machine Learning Algorithmus ist es möglich, die resultierende Verwölbung und die möglichst optimalen Post-mold Cure Parameter für die Testproben vorherzusagen. Die experimentellen Ergebnisse und die Vorhersagen des Machine Learning Modells zeigen, dass die Post-mold Cure Zeit für die getesteten Materialien und Geometrien auf ~15 Minuten reduziert werden kann, wenn der Verzug als wichtigstes Qualitätskriterium für die Optimierung betrachtet wirdIn electronic packaging industry, post-mold cure is a commonly applied process in which the molded thermosetting encapsulants are exposed to elevated temperatures again for several hours after their molding operations to ensure improved material properties via reaching higher cross-linking densities. Some studies in literature and industrial applications showed that it is also a useful method to alleviate the package warpage, which is a major quality criterion. Despite these findings, the effects of different post-mold cure parameters on resultant warpage are still not well-known since it is mostly conducted with the same parameters in industry only to reach higher cross-linking densities without the considerations on warpage. In this study, the effects of post-mold cure process on warpage of an epoxy molding compound encapsulant are investigated. Material characterization tests are performed to investigate the thermal and cure behaviors of encapsulant components. Experiments with varying post-mold cure temperatures and times are conducted to correlate these parameters with the resultant warpage to create a process knowledge. Part warpages are evaluated via 3D optical profilometer scans, and infrared spectra of the samples are measured to non-destructively detect the alterations in chemical composition as an indicator of changing cross-linking density. In the light of the experiments, the warpage reduction mechanism during post-mold cure is explained, which is related to thermal and cure shrinkages, as well as the glass transition behaviors of the materials. Moreover, utilizing the acquired experimental data, a machine learning algorithm is proposed which predicts the optimal post-mold cure parameters in accordance with the desired warpage and cross-linking density values after the operation. The algorithm was able to accurately predict the resultant warpage for test samples and the predicted optimal post-mold cure parameters showed an accordance with the experiments. Both experiment results and algorithm predictions showed that the post-mold cure time can be reduced to ~15 minutes from several hours when warpage is considered as the main quality criterion to optimize for the materials and the geometry tested in the experiment
DNA groove binder and significant cytotoxic activity on human colon cancer cells: Potential of a dimeric zinc (II) phthalocyanine derivative
No full textThe interaction of a multi-component system consisting of benzene-1,4-diyldimethanimine-bridged dimeric zinc-phthalocyanine groups (4OMPCZ) with calf thymus DNA (ct-DNA) was investigated using UV-Vis absorption, fluorescence emission spectroscopy methods, and viscosity measurements. The binding constant, Kb, which is an important parameter to gain information about the binding mode, was found as 9.7 x 107 M-1 from the UV-Vis absorption studies. Another important spectrophotometric tool is competitive displacement assays with Ethidium bromide and Hoechst 33342. Through this experiment, a higher KSV value was obtained with Hoechst for the phthalocyanine derivative, 4OMPCZ, and the ct-DNA complex than with ethidium bromide. Additionally, mo-lecular docking studies were conducted to calculate the theoretical binding constant and visualize the in-teractions of 4OMPCZ with a model DNA. According to docking results, although the interactions are mainly located in the major groove of the DNA helix, due to the wrapping, these interactions can also be extended to the minor groove of the DNA. Spectrophotometric, molecular docking, and viscosity studies revealed that the interaction of 4OMPCZ with DNA is likely to be via the major and minor grooves. The in vitro cytotoxic activity of 4OMPCZ was evaluated by MTT assay on human colon cancer cells (HT29) after 72 h of treatment. 4OMPCZ indicated significant cytotoxic activity when stimulated with UV light compared to the standard chemotherapy drugs, fluorouracil (5-FU), and cisplatin on HT29 colon cancer cells. The IC50 value of 4OMPCZ displayed considerably lower concentrations compared to the standard drugs, 5-FU, and cisplatin
Inducible overexpression of a FAM3C/ILEI transgene has pleiotropic effects with shortened life span, liver fibrosis and anemia in mice
Get PDFFAM3C/ILEI is an important factor in epithelial-to-mesenchymal transition (EMT) induction, tumor progression and metastasis. Overexpressed in many cancers, elevated ILEI levels and secretion correlate with poor patient survival. Although ILEI’s causative role in invasive tumor growth and metastasis has been demonstrated in several cellular tumor models, there are no available transgenic mice to study these effects in the context of a complex organism. Here, we describe the generation and initial characterization of a Tet-ON inducible Fam3c/ILEI transgenic mouse strain. We find that ubiquitous induction of ILEI overexpression (R26-ILEIind) at weaning age leads to a shortened lifespan, reduced body weight and microcytic hypochromic anemia. The anemia was reversible at a young age within a week upon withdrawal of ILEI induction. Vav1-driven overexpression of the ILEIind transgene in all hematopoietic cells (Vav-ILEIind) did not render mice anemic or lower overall fitness, demonstrating that no intrinsic mechanisms of erythroid development were dysregulated by ILEI and that hematopoietic ILEI hyperfunction did not contribute to death. Reduced serum iron levels of R26-ILEIind mice were indicative for a malfunction in iron uptake or homeostasis. Accordingly, the liver, the main organ of iron metabolism, was severely affected in moribund ILEI overexpressing mice: increased alanine transaminase and aspartate aminotransferase levels indicated liver dysfunction, the liver was reduced in size, showed increased apoptosis, reduced cellular iron content, and had a fibrotic phenotype. These data indicate that high ILEI expression in the liver might reduce hepatoprotection and induce liver fibrosis, which leads to liver dysfunction, disturbed iron metabolism and eventually to death. Overall, we show here that the novel Tet-ON inducible Fam3c/ILEI transgenic mouse strain allows tissue specific timely controlled overexpression of ILEI and thus, will serve as a versatile tool to model the effect of elevated ILEI expression in diverse tissue entities and disease conditions, including cancer
Dijitalleşen dünyada iş süreç yönetiminin yeri
No full textTeknolojik gelişmelerdeki değişimin hızlı temposuna ayak uydurmaya çalışan birçok kuruluş için iş süreçleri yönetimi (Business Process Management, BPM), dijital dönüşümde ustalaşmanın ve iş modellerini yenilemenin bir anahtarı olarak görülmektedir. İş Süreçleri Yönetimi: Kavramlar, Araçlar ve Teknolojiler başlıklı bu kitap, iş süreçlerinin etkili yönetimini gerektiren temel bilgilerin yanı sıra iş süreçlerinin etkili yönetimine atfedilen araçlar, kavramlar ve teknolojilerle ilgili güncel bilgiler sunmaktadır. Kitapta, süreç modelleme, süreç optimizasyonu, iş akış yönetimi, süreç otomasyonu, süreç madenciliği, süreç analizi gibi temel konuların yanı sıra dijitalleşme, bulut bilişim, sosyal medya, büyük veri, iç kontrol, yönetim yetkinlikleri, liderlik, kültür gibi kritik konular iş süreçleri yönetimi çatısı altında alanında uzman akademisyenler tarafından ele alınmıştır. BPM alanının en iyi uygulamaları ile ilgilenen uygulayıcıların, işletme yöneticilerinin, araştırmacıların, akademisyenlerin, lisans ve lisansüstü öğrencilerin bu kitabın her bölümünü okumaktan keyif almasını umuyoruz. Kitapta ele alınan bazı konular şu şekildedir: • İş Süreçleri Yönetimi Yaşam Döngüsü • İş Süreçlerinin Modellemesi • Süreç Madenciliğinin Temelleri • İş Süreçleri Yönetimi ve Robotik Süreç Otomasyonu • Dijitalleşme ve İş Süreçleri Yönetimi • İş Süreçleri Yönetimi ve Bulut Bilişim • İş Süreçleri Yönetimi ve Sosyal Medya • İş Süreçleri Yönetimi ve Büyük Veri Analitiği • İş Süreçleri Yönetiminde İç Kontrol • İş Süreçleri Yönetiminde Yönetim Yetkinlikleri • İş Süreçleri Yönetiminde Liderlik • İş Süreçleri Yönetiminde Kültü
Serebral palsili hastalarda makine öğrenmesi ile eklem açılarından yürüyüş kinetiğinin kestirilmesi
No full textSerebral palsili (SP) hastalarda yürüme sırasında eklem momentleri ve yer reaksiyon kuvveti (YTK), klinik karar verme sürecinde değerli bilgiler sağlar. Eklem momentleri, ters kinematik modeller kullanılarak YTK'ne dayalı olarak hesaplanır. SP'li hastalardan YTK elde etmek zorlu bir süreçtir. Sağlıklı bireylerde eklem momentleri ve YTK'leri, makine öğrenmesi (MÖ) kullanılarak eklem açılarından tahmin edilmiştir, ancak SP'li hastalar üzerinde böyle bir çalışma henüz yapılmamıştır. Bu nedenle, bu çalışmada SP'li hastalarda ve sağlıklı bireylerde yürüme sırasında gövde, pelvis, kalça, diz ve ayak bileği kinematiği temel alınarak dikey YTK, dorsi-plantar fleksiyon, diz fleksiyon-ekstansiyon, kalça fleksiyon-ekstansiyon ve kalça addüksiyon-abdüksiyon momentlerinin bir boyutlu konvolüsyonel sinir ağları kullanılarak tahmin edilmesi amaçlandı. SP ve sağlıklı deneklerin anonimleştirilmiş geriye dönük yürüme verileri kullanıldı. Veriler, Heidelberg Üniversitesi, Ortopedi ve Travmatoloji Bölümü'nde son yirmi yıl içinde hastaların klinik çalışmaları sırasında toplanmıştır. MÖ çalışmasını genişletmek için, yürüme kinematiğinin zaman alanı özniteliklerinin manuel ve otomatik olarak çıkarılması yöntemleri kullanılarak ridge regresyon, rastgele karar ormanı, çok katmanlı sinir ağı, k-en yakın komşu, uzun-kısa süreli bellek sinir ağı algoritmalarının özelleştirilmiş MÖ modelleri eğitildi. Performansları, normalize edilmiş karesel ortalama hata (nKOH) ve Pearson korelasyon katsayısı (PCC) kullanılarak izole edilmiş test örneği gruplarında değerlendirildi ve karşılaştırıldı. Eklem momentleri, SP grubu için %18,02 ila %13,58 arasında nKOH ve sağlıklılar grubu için %12,55 ila %8,58 arasında nKOH ile tahmin edildi, SP grubu için 0,90 ila 0,96 arasında PCC ve sağlıklılar grubu için 0,96 ila 0,99 arasında PCC ile tahmin edildi. YTK, sağlıklı bireyler için %7,47 nKOH ve SP'li hastalar için %11,75 nKOH ile tahmin edildi, sağlıklılar grubu için 0,98 PCC ve SP grubu için 0,94 PCC ile tahmin edildi. Makine öğrenimi algoritmaları, manuel ve otomatik çıkarılmış öznitelikleri kullanarak benzer performans sergiledi. Makine öğrenimine dayalı eklem momenti tahmini, SP'li hastalarda geleneksel moment hesaplamanın yerine geçebilir, ancak mevcut düzeydeki tahmin hataları, klinik karar vermede bugün kullanımını sınırlamaktadır.Joint moment and ground reaction force (GRF) during gait provide valuable information for clinical decision-making in patients with cerebral palsy (CP). Joint moments are calculated based on GRF using inverse dynamics models. Obtaining GRF from patients with CP is challenging. Typically developed (TD) individuals' joint moments and GRFs were predicted from joint angles using machine learning (ML), but no such study has been conducted on patients with CP. Accordingly, we aimed to predict the vertical GRF, dorsi-plantar flexion, knee flexion-extension, hip flexion-extension, and hip adduction-abduction moments based on the trunk, pelvis, hip, knee, and ankle kinematics during gait in patients with CP and TD individuals using one-dimensional convolutional neural networks. The anonymized retrospective gait data of CP and TD subjects were used. The data were collected in the course of patient care over the last two decades in the Department of Orthopedics and Traumatology of Heidelberg University. For broadening the ML study, we trained specific ML models of ridge regression, random forest, multilayer neural network, k-nearest neighbour, long short term memory neural network algorithms by using manually extracted time domain features and automatically generated features of gait kinematics. Their performances were evaluated and compared using isolated test subject groups based on normalized root mean square error (nRMSE) and Pearson correlation coefficient (PCC). Joint moments were predicted with nRMSE between 18.02% and 13.58% for the CP and between 12.55% and 8.58% for the TD groups, whereas with PCC between 0.90 and 0.96 for the CP and between 0.96 and 0.99 for the TD groups. GRF was predicted with an nRMSE of 7.47% for TD subjects and 11.75% for CP subjects, while with a PCC score of 0.98 for the TD and 0.94 for the CP group. ML algorithms using time domain features and automatically generated features showed similar performance. ML-based joint moment prediction from kinematics could replace conventional moment calculation in CP patients in the future, but the current level of prediction errors restricts its use for clinical decision-making today
Bilgisayarlı tomografi verileri üzerinde görüntü işleme yoluyla geliştirilmiş açık gözenekli reçine köpüklerinin eklemeli imalatı ve mekanil özellikleri
Get PDFMalzemelerin bilgisayarlı tomografi (BT) verilerinden veri dönüştürme, modelleme için yaygın olarak kullanılmaktadır. Bununla birlikte, BT verileri aracılığıyla açık hücreli köpüklerin fiziksel üretimi köpükler için nadiren gerçekleştirilmiştir. Burada, deformasyon mekanizmalarını değiştirerek enerji soğurma özelliklerini geliştirmek için ticari olarak mevcut köpük BT verileri üzerinde görüntü işleme kullanarak yeni köpük yapıları oluşturmayı amaçlıyoruz. Bu çalışmada, Maskeli Stereolitografi Aparatı (MSLA) gibi eklemeli üretim teknikleri kullanılarak, piyasada bulunan çelik köpüklerin bilgisayarlı tomografi verilerinden bir dizi köpük oluşturulmuştur. Bu setler 10ppi (inç başına gözenek), 3ppi, birleştirilmiş (10ppi ile 3ppi birleştirilmiş) ve 10ppi aşındırılmıştır. Yarı statik sıkıştırma kullanılarak yapılan testler, köpüklerin mekanik performansını ve özelliklerini karakterize etmek için kullanılmıştır. Yoğunluğun derecelendirilmesi, yoğunlaşma gerinimini azaltır ve plato rejiminin eğimini artırır. En iyi enerji emme kapasitesi, özgül mukavemet ve yoğunlaşma gerilmesi, yüksek bağıl yoğunluklarda birleştirilmiş köpükler tarafından gösterilmiştir. 3ppi, 10ppi ve 10ppi yoğunluk dereceli köpükler, dikmelerin bükülmesiyle deforme olur. Eğilme baskın yapı, birleştirilmiş köpükler durumunda gerilme baskın bir yapıya dönüşmüştür. Ayrıca, yapılar aynı hücre/dikme boyutları ve kusurlarla yeniden üretilebildiğinden, katkılı olarak üretilen reçine köpükler, geleneksel olarak üretilen metal köpüklere göre daha az mekanik özellik dağılımına sahiptirData conversion from computed tomography (CT) data of materials has been widely used for modeling. However, the physical production of open-cell foams through CT data has rarely been conducted for foams. Here we aim to create novel foam structures using image processing on the CT data commercially available foam to enhance energy absorption properties by modifying the deformation mechanisms. In this study, with the use of additive manufacturing techniques such as Masked Stereolithography Apparatus (MSLA), a set of foams were created from computed tomography data of the commercially available steel foams. The sets are 10ppi (pores per inch), 3ppi, merged (10ppi combined with 3ppi) and 10ppi eroded. Testing using quasi-static compression has been used to characterize the mechanical performance and properties of the foams. Grading density decreases the densification strain and increases the plateau regime's slope. The best energy absorption capacity, specific strength, and densification strain were demonstrated by combined foams at high relative densities. 3ppi, 10ppi and 10ppi density-graded foams deform by bending of struts. The bending-dominated structure transformed into a stretch-dominated structure in the case of merged foams. Furthermore, because structures may be remanufactured with the same cell/strut dimensions and imperfections, additively generated resin foams have less mechanical property scattering than conventionally manufactured metal foam