bluuebunny/crossref_metadata_2025 huggingface dataset:
International geological significance of the potential Al-Medina volcanic UNESCO Global Geopark Project in Saudi Arabia revealed from multi-satellite remote sensing data
Authors: Fu Han , Fu Bihong , Shi Pilong , Zheng Yuanyuan
Published: November 2021

UNESCO Global Geoparks should be of international geological significance in terms of their scientific quality, rarity, aesthetic appeal and tourism value. At least nine Cenozoic volcanic fields are developed in the western Saudi Arabia, with a total area of 180,000 km2. In this paper, the geological and geomorphological features of these volcanic fields induced by the expansion of the Red Sea are interpreted and displayed using multi-source satellite images, such as Landsat-8 OLI (Operational Land Imager) and Gaofen-2 data. Our results show that the Al-Medina volcanic field (AMVF) has great prospects as the aspiring volcanic Geopark in Saudi Arabia. This study indicates that: (1) AMVF has international geoscientific significance and rare natural attribute because the volcanic fields are induced by the rising mantle plume and rare examples of white volcanoes comprised mainly from felsic rock; (2) AMVF has abundant volcanic landscapes, including completely preserved cones and craters and multi-phase lava flows from different eruption stages, which have great aesthetic appreciation and tourism values to attract the general public; (3) AMVF is close to the second holy city of Islam-Medina, which has convenient transportation and is suitable to develop tourism to promote the development of the local economy; (4) AMVF had erupted repeatedly (the latest eruption was in 1256 AD), establishment of the UNESCO Global Geopark Project can not only prevent potential geological hazard risks to the people living in Medina city from future volcanic eruption events, but also provide better protection and conservation to geoheritage sites being damaged by human activities, for example setting protected boundaries of AMVF to avoid the destruction of volcanic landscape integrity caused by urban expansion.
Fatal pancreatic fistula after laparoscopic distal pancreatectomy for intraductal papillary mucinous carcinoma with pancreaticobiliary maljunction and sphincterotomized papilla: a case report
Authors: Morita Yoshifumi , Akutsu Tomohiro , Makino Mitsumasa , Obayashi Miku , Ida Shinya , Muraki Ryuta , Kitajima Ryo , Hirotsu Amane , Takeda Makoto , Kikuchi Hirotoshi , Hirmatsu Yoshihiro , Hamaya Yasushi , Sugimoto Ken , Kato Hiromi , Doi Matsuyuki , Tanahashi Yukichi , Goshima Satoshi , Sakaguchi Takanori , Takeuchi Hiroya
Published: November 2021

Background

Pancreatic juice is constantly activated by contaminated bile in patients with pancreaticobiliary maljunction (PBM). Here, we report a case of laparoscopic distal pancreatectomy for a patient with PBM and sphincterotomized papilla, resulting in fatal pancreatic fistula.

Case presentation

A 79-year-old man was diagnosed with pancreatic intraductal papillary mucinous neoplasm and common bile duct stones. Endoscopic sphincterotomy was performed prior to surgery. The pancreatic duct was simultaneously visualized when the contrast agent was injected into the common bile duct. Sudden bleeding was observed from the abdominal drain on postoperative day (POD) 6. Emergent stent graft placement and coil embolization were performed for bleeding from the splenic artery. On POD 9, the drainage fluid changed to yellowish in color with bile contamination. For internal drainage of the digestive fluid, endoscopic retrograde biliary tube and pancreatic drainage tube were placed. On POD 24, second emergent coil embolization was performed for bleeding from the left gastric artery. On POD 25, open abdominal drainage was performed. On POD 32, third emergent coil embolization was performed for bleeding from the gastroduodenal artery. Subsequently, remnant pancreatic resection was performed. On POD 39, massive bleeding was again observed from the abdominal drain. Emergency arterial portography revealed bleeding in the right wall of the superior mesenteric vein. The patient died of hemorrhagic shock on the same day.

Conclusions

The extreme risk of severe pancreatic fistula after distal pancreatectomy should be considered in patients with PBM and sphincterotomized papilla. In this extraordinary situation, surgeons should promptly decide whether to resect the remnant pancreas to prevent losing the patient.
Translation and adaptation of the EORTC QLQ-LC 29 for use in Chinese patients with lung cancer
Authors: Dai Wei , Wang Yaqin , Liu Yangjun , Wei Xing , Osman Ahmed M. Y. , Pompili Cecilia , Koller Michael , Wang Qifeng , Wang Yi , Ge Jun , Xie Tianpeng , Li Qiang
Published: November 2021

Background

The latest European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire-Lung Cancer 29 (QLQ-LC29) has been translated and validated in several languages but not yet in simplified Chinese. This study aimed to translate this questionnaire into simplified Chinese and adapt it for use in Chinese patients with lung cancer.

Methods

The translation and adaptation process followed the EORTC translation procedure, and consisted of eight steps, namely, translation preparation, forward translations, reconciled translation, back translations, a back translation report, proofreading, pilot testing, and finalisation. The pilot testing included 10 patients with lung cancer.

Results

We obtained the permission to perform the EORTC QLQ-LC29 translation work on November 17, 2020. Thereafter, it took 3 weeks to complete the forward translations, reconciled translation, and back translations. After several rounds of discussion with the EORTC Translation Unit, 19 items used the existing translations from the EORTC Item Library (a database of EORTC questionnaire items and their translations), and 10 items were translated from scratch. The 10 patients included in the pilot testing phase had a median age of 64 years (range 31–69 years); five were male, five had an educational level of high school or above, and six had undergone surgery. Eight items received comments from patients (six items by one patient alone and the other two items by three patients). No patients commented on the instructions or the format used for responses. After discussion with the EORTC Translation Unit, we modified the Chinese wording in item 50 to ensure that the meaning of “lifeless” was clear. No changes were made to the remaining items.

Conclusions

The simplified Chinese version of the EORTC QLQ-LC29 is now available on the EORTC website. This translation may contribute to the application of the EORTC QLQ-LC29 scale in both research and clinical practice in the Chinese population with lung cancer. Further evaluation of the psychometric properties of the translated EORTC QLQ-LC29 is warranted.
Health-related quality of life for adults living with hepatitis B in the United States: a qualitative assessment
Authors: Freeland Catherine , Racho Rhea , Kamischke Maureen , Moraras Kate , Wang Evangeline , Cohen Chari , Kendrick Stuart
Published: November 2021

Background

In 2019, an estimated 296 million people were living with chronic hepatitis B virus (HBV) globally with approximately 2.4 million living within the United States. Those living with HBV require years if not decades of regular monitoring to prevent liver complications from occurring. The aim of this study was to explore the working conceptual framework of health related quality of life (HRQL) for those living with chronic HBV through qualitative analysis.

Methods

Data were collected by in-depth telephone interviews conducted in 2019 using purposeful sampling as part of a disease understanding assessment on the HBV patient experience within the United States. A directed content analysis approach was utilized by creation of a codebook to guide the organization of data, codes were developed by review of the literature (a priori) and through line-by-line reading of a subsample of queries. All transcripts were analyzed by at least two members of the study team and intercoder reliability was assessed using Dedoose software.

Findings

A sample of 19 individuals living with chronic HBV were included within this study. Themes identified from transcripts noted the significant overlap between the reported experience of HBV and constructs within the HRQL model. The psychological impact of chronic HBV on study participants’ HRQL overall was considerable and contributed to depression, anxiety, homelessness, drug use, and incarceration.

Conclusion

Our analysis supports the hypothesis that HBV impacts HRQL and often negatively affects emotional health. Our findings suggest that it would be beneficial to include HRQL assessment in the medical management of HBV, so that interventions can focus on reducing the burden of disease and improving quality of life for those living with HBV.
Evaluation of plantar fasciitis improvement after shock wave therapy in calcaneal spur patients by musculoskeletal ultrasonography
Authors: El Molla Soad Said , Fahmy Ahmed M. , Gamil Amr Mohamed , Ibrahim Rehab Ali , Kamel Mai Mohamed
Published: November 2021

Background

Plantar fasciitis due to calcaneal spur is a common cause of heel pain and functional disability, and its management presents a huge challenge for clinicians which results sometimes in unpleasant clinical outcomes. The efficacy of extracorporeal shock wave therapy (ESWT) as an alternative therapeutic option to surgical management after failure of conservative treatment has been addressed. Our aim was to evaluate the efficacy of ESWT in the treatment of plantar fasciitis in calcaneal spur patients using ultrasonography.

Results

The mean plantar fascia (PF) thickness was statistically significantly higher in the calcaneal spur patient group (5.66 ± 1.14 mm) than in the healthy control group (2.40 ± 0.35 mm), (P = 0.001). Significant PF thickness reduction, visual analog scale (VAS), and Roles and Maudsley score (RMS) improvement were observed (P < 0.001) after 4 sessions of ESWT.

Conclusion

PF thickness increases significantly in calcaneal spur patients and responds to treatment. ESWT decreases the thickness of the PF and improves pain and function significantly.
Impacts of model resolution on multiple prediction
Authors: Ma Yue , Liu Yujin , Luo Yi
Published: November 2021

Despite theoretical advancements in multiple identification and elimination, the application and success of these advancements are questionable in some cases and are limited to marine environments, especially deepwater. In land seismic, however, a clear understanding of the internal multiple generators is not readily available; thus, efforts to attenuate them often are quite ineffective. We have analyzed, in the case of many thin layers, how the primaries and multiples are affected by fine-scale variations in the velocity model. Cross-coherence is used to measure the similarity of the original primaries/multiples and the ones generated from upscaled velocity models. The combined use of kurtosis and the cross-coherence method enables us to precisely quantify the impact of fine layering on multiples. Test results demonstrate that surface-related multiples and internal multiples are much more sensitive than the primaries to thickness variations of the velocity model. As the thickness of each upscaled layer varies from 1 to 21 m, multiples change rapidly, whereas primaries are almost the same. The high sensitivity of internal multiples on fine layering suggests that the detailed model information should be considered in model parameterization in the internal multiple removal, especially for model-driven methods.
Impact of Thyroglobulin and Thyroglobulin Antibody Assay Performance on the Differential Classification of DTC Patients
Authors: Schoonen Lise , Neele Marjolein , van Toor Hans , van Kinschot Caroline M J , van Noord Charlotte , Visser W Edward , Groen Joost , Boesten Lianne S M , Lentjes Eef G W M , van den Berg Sjoerd A A , Kos Snjezana
Published: November 2021

Context

Measurements of thyroglobulin (Tg) and Tg antibodies are crucial in the follow-up of treated differentiated thyroid cancer (DTC) patients. Interassay differences may significantly impact follow-up.

Objective

The aim of this multicenter study was to explore the impact of Tg and Tg antibody assay performance on the differential classification of DTC patients, as described in national and international guidelines.

Design

Four commonly used Tg and Tg antibody assays were technically compared to reflect possible effects on patients with DTC follow-up. Storage stability at different storage temperatures was also investigated for LIAISON® and Kryptor assays, as this is an underexposed topic in current literature.

Results

B.R.A.H.M.S. assays yield approximately 50% lower Tg values over the whole range compared to the DiaSorin and Roche assays investigated. These differences between assays may result in potential misclassification in up to 7% of patients if fixed cutoffs (eg, 1 ng/mL) are applied. Poor correlation was also observed between the Tg antibody assays when the method-specific upper limits of normal are used as cutoffs. Storage of Tg and Tg antibodies was possible for 3 to 4 weeks at −20°C and −80°C. Calibration of the assays, however, was found to be crucial for stable results over time.

Conclusions

Technical aspects of Tg and Tg antibody assays, including interassay differences, calibration and standardization, and cutoff values, may have a significant clinical impact on the follow-up of DTC patients.
Queer Trauma in Caitlín R. Kiernan’sThe Red Tree
Authors: Marshall Nowell
Published: November 2021

Despite winning numerous literary awards, Caitlín R. Kiernan’s work has received little critical attention. Scholars have focused on Kiernan’s reworking of H. P. Lovecraft’s influential weird fiction and have discussed Kiernan’s pioneering work in New Weird fiction and short fiction. As astute as much of the critical work is, none of it addresses the cornerstone of Kiernan’s fiction: trauma. This essay considers Kiernan’s novel The Red Tree as a queer American gothic novel dealing with trauma and its lingering effects on its witnesses. Through its complex, fragmentary form and its use of dream sequences and unconsciously produced narratives, the novel invites readers to witness and consume Sarah Crowe’s trauma while loosely theorizing the relationship between trauma and queer temporality and spatiality.
Mapping of a multilayer panoramic radiography device
Authors: Martins Luciano Augusto Cano , Nascimento Eduarda Helena Leandro , Gaêta-Araujo Hugo , Oliveira Matheus L , Freitas Deborah Queiroz
Published: November 2021

Objective:

To map the shape, location, and thickness of the focal trough of a panoramic radiography device with a multilayer imaging program.

Methods:

An acrylic plate (148 × 148 × 3 mm) containing 1156 holes distributed in a matrix of 34 × 34 rows was placed in the OP300 Maxio at the levels of the maxilla and mandible. 20 metal spheres (3.5 mm in diameter) were placed on the holes of the plate under 15 different arrangements and panoramic images were acquired for each arrangement at 66 kV, 8 mA, and an exposure time of 16 s. The resulting panoramic radiographs from the five image layers were exported, the horizontal and vertical dimensions of the metal spheres were measured in all images using the Image J software, and the magnification and distortion rates of the spheres were calculated. All metal spheres presenting a magnification rate lower than 30% in both vertical and horizontal dimensions and a distortion rate lower than 10% were considered to map the focal troughs of each of the five image layers.

Results:

All panoramic image layers had a curved shape ranging from 39° to 51° for both dental arches and varied in position and thickness. The anterior region of maxilla was anteriorly displaced when compared to the anterior region of the mandible for all layers. Image layers are thicker at the level of the mandible than those at the level of the maxilla; also, inner layers were thinner and outer layers were thicker.

Conclusion

All image layers in the studied panoramic radiography device had a curved shape and varied in position and thickness. The anterior region of maxilla was anteriorly displaced when compared to that of the mandible for all layers.
La maîtrise de la dépense publique et la réforme de la gestion financière publique en Grèce
Authors: Βράνιαλη Ευφροσύνη
Published: November 2021

Οι τρέχουσες ανάγκες για τον εξορθολογισμό της διαχείρισης του κράτους οδηγούν όχι μόνο στον έλεγχο των δημοσίων δαπανών αλλά και στη βελτίωση της δημοσιονομικής διαχείρισης των δημόσιων κονδυλίων. Η Ελλάδα, με τη σειρά της, ανέλαβε την πρόκληση να εγκαινιάσει μια νέα κουλτούρα διαχείρισης που βασίζεται στην ενισχυμένη διαφάνεια και τον καλύτερο έλεγχο των δημόσιων πόρων, όπως αναπτύχθηκε τόσο σε διεθνές όσο και σε ευρωπαϊκό επίπεδο. Ωστόσο, οι προκλήσεις αυτής της νέας κουλτούρας που συνδέονται με μια νέα λογική πιο ενεργούς δημοσιονομικής διαχείρισης βρίσκονται σε πλήρη αντίθεση με την υπάρχουσα υποδομή του ελληνικού δημοσιονομικού δικαίου, όπως αναπτύσσεται από την αντίστοιχη νομοθεσία και νομολογία, καθώς και όπως αποτυπώνεται στο υφιστάμενο λογιστικό σύστημα και γενικά στον οικονομικό έλεγχο του κράτους. Υπό το φως των ανωτέρω και με αφορμή την επιδείνωση των δημόσιων οικονομικών και της σχετικής ανάγκης προσαρμογής στο νέο κοινωνικοοικονομικό περιβάλλον, η Ελλάδα έχει ξεκινήσει τον εκσυγχρονισμό των τεχνικών και εργαλείων διαχείρισης, συμπεριλαμβανομένων εκείνων της αναθεώρησης του συστήματος διαχείρισης και της δημιουργίας συστημάτων πληροφόρησης και αξιολόγησης προσανατολισμένα προς την έννοια της απόδοσης. Αντλώντας τα διδάγματα από ξένες εμπειρίες, οι Έλληνες δημόσιοι φορείς κλήθηκαν να δράσουν και να καθοδηγήσουν τη μετάβαση προς μια νέα λογική δημοσιονομικής διακυβέρνησης προσαρμοσμένης στις ηθικές και επαγγελματικές αξίες του κράτους και σύμφωνα με τις απαιτήσεις μιας σύγχρονης δημοκρατίας.
СРАВНИТЕЛЬНЫЙ АНАЛИЗ СКЛОННОСТИ К ЗАВИСИМОСТЯМ У СТУДЕНТОВ РАЗНЫХ ПРОФИЛЕЙ ПОДГОТОВКИ
Authors: Levina Irina L. , Korol Leonid N.
Published: November 2021

Актуальность исследования связана с высоким риском распространения различных видов зависимости в студенческой среде. Изучение склонности студентов к какому-либо действию, связанному с употреблением тех или иных веществ (химическая зависимость), или к какой-либо активности (нехимическая /поведенческая зависимость) позволяет проводить профилактику и раннюю коррекцию до развития зависимости. Целью работы является сравнительный анализ склонности к различному виду зависимости у студентов, обучающихся по различным направлениям и профилям подготовки. Анонимно проанкетирован 121 студент выпускных курсов трех профилей подготовки. Использованы методика диагностики склонности к 13 видам зависимостей и общей склонности к зависимому поведению Лозовой Г.В., MAST-тест (Мичиганский тест на алкоголизм) и CAGE-тест (стандартизированный опрос для диагностики алкогольной зависимости). Проведенное исследование показало отсутствие среди обследованных студентов лиц с развернутыми формами химической или поведенческой зависимости, но выявило существенные отличия между ними по склонности к разным видам зависимостей. У 36,7% студентов имеется высокий уровень предрасположенности к алкогольной зависимости, а у 14% есть реальный риск развития алкоголизма. Наиболее подвержены развитию химической зависимости студенты-юристы. Полученные в исследовании данные следует обязательно учитывать при разработке воспитательных и профилактических программ, осуществляемых в вузе.
ПОНЯТИЯ «ГЕНДЕР» В ИДЕОЛОГИИ ФЕМИНИЗМА: ФИЛОСОФСКИЙ АНАЛИЗ
Authors: Neronov Alexander V. , Neronova Marina Yu.
Published: November 2021

В данной статье дается философский анализ понятия «гендер», как основания идеологии современного феминизма.

Цель: рассмотреть явление феминизма с позиции философского дискурса.

Метод и методология проведения работы: использовались исторический, феноменологический и диалектический методы исследования.

Результаты: современный феминизм можно считать одним из социально-культурных течений в рамках женского движения, обладающим собственной идеологией. При этом радикальный феминизм следует отнести к экстремистской идеологии, направленной на разрушение сложившихся социальных структур, общественного мировоззрения, морали и устоев государственности.

Область применения результатов: Полученные результаты могут быть использованы при изучении современных общественных и культурных процессов.
МЕТАФОРА КАК КРЕАТИВНЫЙ АТТРАКТОР В РЕКЛАМНОМ ТУРИСТИЧЕСКОМ НАРРАТИВЕ
Authors: Men’shikova Ekaterina E.
Published: November 2021

Обоснование. Статья посвящена исследованию потенциала метафорических креативных аттракторов в рекламном туристическом нарративе. Значение работы обусловлено ее соотнесенностью с современными лингвистическими исследованиями, направленными на описание фрагментов языковой картины мира, в которой важное место занимает метафорическая составляющая. Фрагментарность изученности вопросов языкового наполнения креативного аттрактора в текстах разного типа, его качеств и функционально-прагматических характеристик актуализируют проблему данного исследования.
Цель. Установление и описание текстообразующего потенциала метафорических креативных аттракторов в рекламном туристическом нарративе.
Материалы и методы. В качестве материала для исследования использовались тексты рекламного туристического нарратива сети Интернет. Для достижения цели и решения поставленных задач в работе использовались следующие методы исследования и приемы анализа: метод анализа и синтеза теоретического материала; метод сплошной выборки; метод метафорического моделирования; описательный метод.
Результаты. Результаты исследования показали, что метафорические креативные аттракторы выступают доминантами текста рекламного туристического нарратива, посредством которых привлекается, фокусируется и удерживается внимание и интерес реципиента текста. Подчеркивается способность креативного аттрактора как репрезентации темы целого текста или его фрагмента и развертыванию его структуры. Автор приходит к выводу, что аттрактор актуализирует тему/проблему и аккумулирует маркеры ценностно значимой информации.
Область применения результатов. Результаты исследования могут быть использованы при разработке курсов лекций и семинаров по общему языкознанию, лингвистической семантики, теории и стилистики текста.
УСТРОЙСТВО ИНВАЛИДНЫХ ДОМОВ В РОССИЙСКОЙ ИМПЕРИИ В ГОДЫ ПЕРВОЙ МИРОВОЙ ВОЙНЫ
Authors: Bukalova Svetlana V.
Published: November 2021

Обоснование. В современном обществе большое значение имеют ценности социальной справедливости, подразумевающие создание эффективных механизмов социальной защиты уязвимых групп, включая людей с инвалидностью. Это делает востребованным изучение исторического опыта формирования системы социальных гарантий для инвалидов.
Цель исследования – реконструкция механизма устройства инвалидных домов как особой формы призрения военных инвалидов, развивавшейся в Российской империи в годы войны.
Материалы и методы. Исследование выполнено на основе структурно-функционального подхода, позволяющего выделить основные элементы системы призрения инвалидов войны, механизмы их деятельности и взаимодействия и основано преимущественно на архивных материалах.
Результаты. Условия Первой мировой войны вызвали необходимость создания специализированных учреждений для пожизненного призрения военно-увечных, не способных к автономному проживанию. Призрение увечных воинов было возложено на Особую Комиссию Верховного Совета по призрению воинских чинов. Также в устройстве инвалидных домов участвовал широкий круг общественных организаций. В устройстве инвалидных домов Особая Комиссия выступает источником финансирования, местные отделения Елизаветинского комитета и Главные Комитеты Земского Союза и Союза Городов выполняли экспертные функции. С инициативой открытия убежищ могли выступать органы местного самоуправления, общественные организации. Таким образом, помощь военным инвалидам носила комплексный характер.
Область применения результатов. Выводы могут быть положены в основу исследований истории социальной политики, использованы в преподавании истории социальной работы, могут использоваться при совершенствовании механизмов государственно-частного взаимодействия в решении социальных проблем.
ГЕОКУЛЬТУРНАЯ КАРТИНА МИРА П.Н. САВИЦКОГО
Authors: Shmakov Vladimir S.
Published: November 2021

Попытка преодоления противоречий между локальными культурами Запада и Востока, привела евразийцев к пониманию роли географического фактора в развитии социокультурного пространства и осознанию социокультурной миссии России, ее объединительного потенциала.
Целью исследования является анализ влияния географического фактора на развитие геокультурного пространства определяющее особенности социокультурного развития Евразии в концепции П.Н. Савицкого.
Материалы и методы. Использование методологии системного и структурно-функционального анализа способствует объяснению геокультурного развития локальных сообществ на основе изучения применяемых социокультурных практик, дает возможность рассматривать геокультурное пространство как совокупность элементов имеющих устойчивые связи, обеспечивающие воспроизводимость традиций в сочетании с новациям.
Результаты. Показано, что евразийство можно рассматривать как своеобразную попытку подготовки формирования идеологии евразийской государственности способной противостоять давлению западных концепций. Идеи П.Н. Савицкого о влиянии географического фактора на развитие геокультурного пространства России и Евразии в целом, позволяют оценить возможность возвращения Российской Федерации к имперским традициям российской государственности. Исследование развития геокультурного пространства Евразии благоприятствует сохранению локальной социокультурной идентичности, способствует формированию системы евразийской интеграции и поиска новых моделей взаимодействия.
Практическая значимость исследования заключается в обозначении и обосновании проблемы влияния географического фактора, «месторазвития» на формирование евразийского геокультурного пространства, в условиях генерирования евразийской концепции развития российской государственности.
FRACTURE ANALYSIS OF RUBBER TOUGHENED ADDITIVELY MANUFACTURED THERMOSETS
Authors: SHEPHERD MEGAN , MAKARIAN KAMRAN , PALMESE GIUSEPPE , BRUNSTAD NICHOLAS , LAMBERSON LESLIE
Published: November 2021

This study explores the role of rubber toughening on the dynamic fracture behavior of additively manufactured (AM) high-performance thermosetting polymers formed through digital light processing (DLP). Using DLP to create these polymers allows for rapid, agile manufacturing of prototypes meeting the lightweight and building speed requirements of relevance to military mission applications. This method also provides flexibility in part complexity while maintaining relatively high isotropy compared to traditional AM techniques. Previous work has demonstrated a dependence of these DLP specimens on print layer orientation and loading rate, prompting further investigation into other manufacturing parameters to improve toughness [1]. This study examines the role of rubber toughening on the quasi-static and dynamic fracture behavior of bis-GMA thermosets. Current literature largely reports on quasi-static behavior of DLP specimens, although dynamic conditions are more applicable to many realistic loading scenarios and extreme environments often seen in defense applications. Dynamic experiments leverage a unique long bar striker device that impacts a specimen opposite a pre-crack, sending a stress-wave driven load to initiate a dynamic Mode-I (opening) fracture event. Full-field displacement data ahead of the propagating crack is obtained using ultra high-speed imaging combined with 2D digital image correlation (DIC). An elastodynamic solution following the principles of dynamic fracture mechanics extracts the stress intensity factor (SIF) using a least squares fit at crack initiation and a Newton-Raphson scheme for crack propagation. The rubber toughened thermosets in this study exhibited a rate dependence in fracture toughness with the quasi-static SIF being 1.20 MPa and the dynamic SIF being 0.41 MPa .
FAILURE PREDICTION OF COMPOSITE MATERIALS USING DEEP NEURAL NETWORKS
Authors: FONTES ALLYSON , SHADMEHRI FARJAD
Published: November 2021

Fiber-reinforced polymer (FRP) composite materials are increasingly used in engineering applications. However, an investigation into the precision of conventional failure criteria, known as the World-Wide Failure Exercise (WWFEI), revealed that current theories remain unable to predict failure within an acceptable degree of accuracy. Deep Neural Networks (DNN) are emerging as an alternate and time-efficient technique for predicting the failure strength of FRP composite materials. The present study examined the applicability of DNNs as a tool for creating a data-driven failure model for composite materials. The experimental failure data presented in the WWFE-I were used to develop the datadriven model. A fully connected DNN with 23 input units and 1 output unit trained with a constant learning rate (α=0.0001). The network’s inputs described the laminates and the loading conditions applied to the test specimen, whereas the output was the length of the failure vector (L=(σx+σy+τxy)0.5). The DNN’s performance was evaluated using the mean squared error on a subset of the experimental data unseen during training. Network configurations with a varying number of hidden layers and units per layer were evaluated. The DNN with 3 hidden layers and 20 units per hidden layer performed the best. In fact, the network’s predictions show good agreement with the experimental results. The failure boundaries generated by the DNN were compared to three conventional theories: the Tsai-Wu, Cuntze, and Puck theory. The DNN’s failure envelopes were found to fit the experimental data more closely than the above-mentioned theories. In sum, the DNN’s ability to fit higher-order polynomials to data separates it from conventional failure criteria. This characteristic makes DNNs an effective method for predicting the failure strength of composite laminates.
EFFECT OF THERMAL INPUT ON THE TEMPERATURE DISTRIBUTION OF THERMOPLASTIC COMPOSITES MADE BY AUTOMATED FIBER PLACEMENT (AFP)
Authors: MOGHADAMAZAD MEHRSHAD , HOA SUONG V.
Published: November 2021

The heat transfer analysis of thermoplastic composite manufactured using automated fiber placement with a hot gas torch can be done using numerical methods such as finite difference method. The accuracy of the theoretical results depends upon the accuracy of the thermal inputs. The hot gas/air temperature and convection coefficient distributions between the hot gas and the surface of the substrate (thermal inputs) have the significant influence on the accuracy of the resulting theoretical temperature distributions in the deposited laminate. A model predicting theoretical results which agree with experimental measurements is presented
IMPROVED TOW-END DETECTION FOR FIBER PLACEMENT INSPECTION USING MACHINE LEARNING
Authors: BLOM-SCHIEBER ADRIANA W. (AGNES) , GUO WEI , SAMANI EKTA , BANERJEE ASHIS
Published: November 2021

A machine learning approach to improve the detection of tow ends for automated inspection of fiber-placed composites is presented. Automated inspection systems for automated fiber placement processes have been introduced to reduce the time it takes to inspect plies after they are laid down. The existing system uses image data from ply boundaries and a contrast-based algorithm to locate the tow ends in these images. This system fails to recognize approximately 10% of the tow ends, which are then presented to the operator for manual review, taking up precious time in the production process. An improved tow end detection algorithm based on machine learning is developed through a research project with the Boeing Advanced Research Center (BARC) at the University of Washington. This presentation shows the preprocessing, neural network and post‐processing steps implemented in the algorithm, and the results achieved with the machine learning algorithm. The machine learning algorithm resulted in a 90% reduction in the number of undetected tows compared to the existing system.
CRUSH CHARACTERISTICS OF ADHESIVELY BONDED COMPOSITE-ALUMINUM TUBES
Authors: RAMAKRISHNAN MONISH URAPAKAM , MALLICK PANKAJ K.
Published: November 2021

Tubular members are used in the automotive industry for body, chassis, and powertrain components such as front rails, underbody frames or sub frames, driveshaft structures and space frames. They are also extensively used in buses and other heavy vehicle structures. With focus on light-weighting, there is increasing use of multimaterial structures with aluminum and high-performance composites. Joining a variety of materials with different characteristics and compositions is a major challenge for the design of such structures. Hence, adhesive bonding is emerging as one of the key joining technique for multi-material structures due to their compatibility with commonly used lightweight materials. Since tubular joints in automotive structures may experience crush type load, this study considers the crush characteristics of composite-aluminum tubular adhesive joints using finite element analysis.
EFFECT OF MANUFACTURING ON THE TRANSVERSE RESPONSE OF THERMOSET COMPOSITES
Authors: SHAH SAGAR P. , MAIARU MARIANNA
Published: November 2021

This study presents a finite element (FE) based virtual test procedure to investigate the effect of the manufacturing process on the transverse composite response. Computational models of the composite microstructures are generated and analyzed in commercial FE solver Abaqus supplemented by user-written subroutines. Several realizations of the composite microstructure with random fiber arrangement are analyzed assuming appropriate initial stress state and material definitions. The virtual test procedure is established to define the evolution of process-induced in-situ matrix properties through direct and inverse process modeling approaches. Subsequently, the composite microstructures are virtually tested in transverse tension to predict the transverse composite properties by implementing progressive damage models. In order to quantify the effect of manufacturing on the transverse composite response, predictions from the two approaches are compared to a third case which assumes an initial stress-free state and neglects the effect of processing conditions on the in-situ matrix properties. Variations of ±5% in average strength and 18% in standard deviations are observed with respect to ideally cured RVEs. It is established that process modeling in necessary to optimize the residual stress state and improve composite performance.
OPTIMIZATION OF PROCESS PARAMETERS DURING CO-CURE OF HONEYCOMB SANDWICH STRUCTURES
Authors: KERMANI, NAVID NIKNAFS , SIMACEK PAVEL , ADVANI SURESH G.
Published: November 2021

Honeycomb sandwich structures are co-cured to bond partially cured thermoset prepreg facesheets with an adhesive layer to both sides of the honeycomb core under a pre-defined pressure and temperature cycle in an autoclave. High dependency of the co-cure process on the materials and process parameters makes it susceptible to defect such as poorly consolidated facesheet and highly porous bondline which can cause premature failure of the structure. The temperature and pressure in the autoclave and pressure in the vacuum bag are the parameters that describe the cure cycle of the process. In this work, an optimization of the process cycle for the co-cure process of sandwich structures that maximizes the fiber volume fraction within the prepreg and reduces the porosity is presented. The objective function is constructed to reflect the quality of both the facesheet consolidation and bond-line porosity. The Surrogate Optimization Algorithm is employed to find the cure cycle resulting in the highest facesheet consolidation level and the lowest porosity within the bond-line.
MECHANICAL PROPERTIES PREDICTION OF PHENOLIC RESIN: A MOLECULAR DYNAMICS STUDY
Authors: GALLEGOS IVAN , KEMPPAINEN JOSHUA , PATIL SAGAR U. , DESHPANDE PRATHAMESH , GISSINER JACOB , ODEGARD GREGORY
Published: November 2021

Carbon-carbon composites (CCCs) widely used in the aerospace and automotive industries due to their excellent mechanical and thermal properties. Phenolic resins have a relatively high carbon yield, which makes them a suitable candidate for CCCs manufacturing. Molecular Dynamics (MD) can further reduce costs by predicting properties of a material before manufacturing and testing. In the present work, a Molecular Dynamics (MD) model of a crosslinked phenolic resin was developed to predict mechanical properties by implementing the fix bond/react algorithm in LAMMPS. The predicted mass density (ρ) and Young’s Modulus (E) agree well with experimental values and highlights the validity of the topologybased approach to building stable molecular models of phenolic resins.
DESIGNING MULTIFUNCTIONAL INTERFACES TO BRIDGE HETEROGENEOUS MATERIALS TO REDUCE THERMAL FATIGUE
Authors: FERGUSON JOHN B. F , ROY AJIT K. , GANGULI, SABYASACHI , JONES JOHN G. , SHENOGIN SERGEI V. , SIHN SANGWOOK , MAHALINGAM KRISHNAMURTHY
Published: November 2021

Composite interfaces between heterogeneous materials exist in many applications which includes electronics packaging. The interface will affect properties such as mechanical integrity during thermal cycling, heat transport and electrical transport due to the inherent disparate properties such as coefficient of thermal expansion (CTE), atomic structure, interface bonding and fabrication processes. Novel interface engineering will be vital for electronics packaging utilized in extreme environment temperatures beyond the standard ranges such as -55 °C to 150 °C. The failure of standard electronics packaging materials with heterogeneous interfaces under thermal cycle fatigue is investigated. Based on the failure analysis, several multifunctional interfaces are developed to bridge the heterogeneous interface and to provide the desired properties and functionality. Approaches to achieve these heterogeneous structures, the materials choices to preserve the multifunctional properties and the modeling predictions are considered. Test structures are prepared of the candidate interfaces, the morphologies are investigated and testing of the thermal cycle fatigue properties over the range -55 °C to 300 °C is performed and will be discussed.
ONR REVIEW: ARCHITECTED COMPOSITES FOR DAMAGE TOLERANCE IN EXTREME CONDITIONS
Authors: PRABHAKAR PAVANA , DAMODARAN, VINAY , SUBRAMANIYAN ABARINATHAN PUSHPARAJ
Published: November 2021

The long-term goal of this ONR funded project is to facilitate the design of architected composites that play a key role in damage tolerant and resilient structures. The main emphasis is on developing new composite structures with improved performance and durability as compared to conventional structural composites. To that end, we will present our work in detail on the following within the realm of sandwich composites along with a novel Machine Learning framework for stress prediction in composites: 1) Novel recoverable sandwich composite structures: Traditional sandwich cores such as foam core or honeycomb structures are good options for enabling lightweight and stiff structures. Although, these cores are known to dissipate energy under extreme conditions such as impact loading, they experience permanent damage. Here, our goal is to design core structures that undergo substantial deformation without accumulating damage and recover their original geometric configuration after the loading is removed. In contrast to a traditional foam or honeycomb structure, we have developed a multi-layer architected core design that facilitates significant deformation beyond the initial peak load, yielding a larger energy dissipation during impact and other extreme loading scenarios. We utilize the concept of pseudo-bistability of truncated cone unit cells to achieve elastic buckling for energy dissipation and shape recovery of core structures. 2) Tailoring of sandwich composite facings: Our objective is to establish the influence of fiber architecture on moisture diffusion pathways in FRPC facings for enabling damage tolerant facing designs. To that end, we have evaluated the moisture kinetics in FRPCs by developing micromechanics based computational models within FEM. We have explained the effect of tortuous diffusion pathways that manifest within FRPCs due to internal fiber architectures. Finally, we established the relationship between tortuosity and diffusivity that can be used for studying moisture diffusion in other FRPCs.
TOUGHENING OF BORON CARBIDE COMPOSITES BY HIERARCHICAL MICROSTRUCTURING
Authors: DAI JINGYAO , PINEDA EVAN , BEDNARCYK BRETT , SINGH JOGENDER , YAMAMOTO NAMIKO
Published: November 2021

Due to a unique combination of properties including high hardness, low density, chemical and thermal stability, semi-conductivity, and high neutron absorption, boron carbide (B C) is a potential candidate for various applications involving extreme environment. However, B C’s current application is limited because of its low fracture toughness. In this study, a hierarchical microstructure design with features including TiB grains and graphite platelets was used to toughen B C by simultaneously utilizing multiple toughening mechanisms including crack deflection, bridging, and micro-crack toughening. Using field-assisted sintering technology (FAST), B C composites with dense and hierarchical microstructure were fabricated. Previously, the fracture toughness of fabricated B C composites was measured at micro-scale using micro- indentation to have up to 56% improvement. In this work, the B C composites’ fracture toughness was characterized at macro-scale using four-point bending methods and compared with previous results obtained at micro-scale. Micromechanics modeling of fracture behaviors for B C-TiB composites was also performed to evaluate the contributions from experimentally observed toughening mechanisms. From four-point bending tests, B C composites reinforced with both TiB grains (~15 vol%) and graphite platelets (~8.7 vol%) exhibited the highest fracture toughness enhancement from 2.38 to 3.65 MPa·m1/2. The measured values were lower than those obtained using micro- indentation but maintained the general trends. The discrepancy between the indentation and four-point bending test results originated from the complex deformation behaviors triggered by the high contact load during indentation tests. Through micromechanics modeling, introduced thermal residual stress due to thermal expansion mismatch between B C and TiB , and weak interphases at B C-TiB boundaries were identified as the main causes for experimentally observed toughness enhancement. These results proved the effectiveness of hierarchical microstructure designs for B4C toughening and can provide reference for the future design of B4C composites with optimized microstructures for further fracture toughness enhancement.
TOPOLOGY OPTIMIZATION OF PLATE STRUCTURES WITH ANISOTROPIC MATERIALS
Authors: SMITH, HOLLIS A. , NORATO JULIÁN A.
Published: November 2021

This work presents a topology optimization method for the design of structures composed exclusively of rectangular plates made of a predetermined, generally anisotropic material. The geometry projection method is employed to map the highlevel geometry and material properties to a fixed grid for the analysis, thus circumventing the need to re-mesh upon each design iteration. We also impose an overlap constraint in the optimization that reduces waste material when fabricating structures by cutting and joining rectangular plates. We demonstrate our method with a numerical example comparing optimal cantilever beam designs obtained using isotropic- and orthotropic-material plates. For this example, we maximize the stiffness of the structure for a fixed amount of material, and we impose a constraint to reduce overlaps between plates. The examples demonstrate the importance of considering material anisotropy in the design of plate structures. Moreover, it is demonstrated that an optimally stiff design for plates made of an isotropic material can exhibit poor performance if the plates are naively replaced with an anisotropic material.
vELECTROPLATING POLYMER BASED ADDITIVE MANUFACTURED PARTS FOR ENHANCED STRUCTURAL PERFORMANCE
Authors: SENEVIRATNE, WARUNA , TOMBLIN JOHN , SAATHOFF BRANDON
Published: November 2021

Additive manufacturing has been adopted in many aerospace and defense applications to reduce weight and buy-to-fly ratios of low-volume high- complexity parts. Polymer-based additive manufacturing processes such as Fused Deposition Modeling (FDM) has enabled aerospace manufactures to improve the structural efficiency of parts through generative design or topology optimization. This level of design freedom did not exist in the past due to limitations associated with traditional manufacturing processes such as subtractive machining. Improvements in the material and the maturation of the FDM process has led to the production of many non-structural flightworthy parts used in aircraft today. Polymer-based additive manufacturing can be further leveraged in aerospace applications with the addition of electroplated coatings that act as reinforcement. While many of the commonly known electroplated coating applications involve enhancing the part appearance, electroplated coatings can also improve the strength, stiffness, and durability of plastic parts. Depending on the use case, the thickness of the metallic plating material (combination of copper and nickel) can be tailored to achieve the desired composite properties (metal and polymer). In this research, the tensile and flexural mechanical properties were assessed for Ultem™ 9085 FDM printed specimens and compared to specimens with metallic coating thicknesses of approximately 75-μm, 150-μm, and 300-μm. Non- destructive inspections using x-ray computed tomography were performed prior to mechanical testing to assess the electroplated coating thickness variation and overall quality.
A PARIS LAW BASED MESH INDEPENDENT NUMERICAL METHODOLOGY FOR THE SIMULATION OF FATIGUE DRIVEN DELAMINATION IN COMPOSITES
Authors: RUSSO ANGELA , SELLITTO ANDREA , RICCIO ANIELLO
Published: November 2021

Delamination evolution under cyclic loading is one of the most important research topics for the application of composite materials to aerospace, naval, automotive and, in general, transportation fields. Large experimental campaigns are needed to assess the fatigue behavior of Carbon Fiber Reinforced Polymers (CFRPs), which may result extremely time and cost consuming. Nevertheless, composite materials design needs to take into account the evolution of fatigue driven damage. Subsequently, the development of efficient and robust computational finite element methodologies to evaluate progression of delamination in composite structural components subjected to cyclic loading conditions has become relevant. In this paper, a numerical finite element procedure able to simulate the fatigue driven delamination growth is introduced. A Paris-law based cycle jump strategy, combined with the Virtual Crack Closure Technique (VCCT) approach, has been implemented in the commercial Finite Element Code ANSYS MECHANICAL via the Ansys Parametric Design Language (APDL). The main advantages of the proposed numerical procedure, named FT-SMXB, are related to its independence on the time step and element size in the frame of incremental analyses. The procedure has been preliminary validated, in this research study, at coupon level, by comparing the numerical results to literature experimental data on a unidirectional graphite/epoxy Double Cantilever Beam (DCB) specimen. The significant agreement between the obtained numerical results and the literature experimental benchmark data confirms the accuracy and the potential of the proposed methodology.