bluuebunny/crossref_metadata_2025_split huggingface dataset:
Realization of Mirror Shells for X-Ray Telescope by Plasma Forming
Authors: Roussel E. , Fromentin J.P. , Freslon A. 
Published: May 2021

Abstract
Future X-ray space missions will require telescopes with very large effective area, good angular resolution and low weight. To obtain these characteristics it is necessary to produce very thin and light mirror shells that, once integrated into a suitable mechanical structure, will fulfil the requested specifications. To meet these requirements, one approach which seems promising is the use of ceramic materials combined with the plasma forming technology to produce ceramic carriers that are subsequently used to manufacture the x-ray mirror shells by means of the epoxy replication technology on superpolished mandrels. The CEA/Le Ripault has shown the feasibility of producing ceramic carriers (diameter: 600 mm, height: 239 mm). The mass saving is substantial in comparison with the nickel electroforming technology which is now used to manufacture high throughput, medium angular resolution x-ray optics. The achieved out of roundness of the carriers is ± 70 microns; an effort must still be made to meet the requested specification of ± 20 microns.
Near Net-Shape Forming of Thermal Barrier Coated Components for Gas Turbine Engine Applications
Authors: Kim G.E. , Tsantrizos P.G. , Grenier S. , Cavasin A. , Brzezinski T. 
Published: May 2021

Abstract
Many of the recent improvements in gas turbine engines have been attributed to the introduction of thermal barrier coatings (TBC) for superalloy components. There exists, however, some limitations in current fabrication methods for closed hot-section components: less than ideal coating quality, the need for welding, and limited choice of superalloy material. This paper describes a vacuum plasma near-net-shape process that overcomes these limitations. The process is used to fabricate closed components from yttria-stabilized-zirconia with a CoNiCrAlY bond coat and IN-738LC outer layer. The results from the study show that it is possible to produce near-net-shape superalloy parts with good coating properties and the absence of welds. The mold was reusable after minor reconditioning and the coatings were uniform in thickness and microstructure with a smooth surface finish. The bond coat and structural superalloy layers were very dense with no signs of oxidation at the interface. After heat treatment, the mechanical properties of the IN-738LC compare favorably to cast materials.
Thermal Spray Coatings for Fiber Reinforced Polymer Composites
Authors: Ashari A.A. , Tucker R.C. 
Published: May 2021

Abstract
Fiber-reinforced polymer composites are an important class of structural materials, offering high strength-to-weight ratios and high rigidities. For many applications, however, their wear resistance is less than desirable. Wear-resistant thermal spray coatings have the potential to improve the surface properties of fiber-reinforced polymer composites, although some require the application of a bond coat to achieve sufficient adhesion. The present study was conducted to find acceptable bond coat materials and compare their performance. Materials such as polyamides, polyimides, polyether-ether-ketone, or simply aluminum or nickel were found to be suitable bond coats for many composite substrates.
Preparation of Films for Solid Oxide Fuel Cells by Center-Injection Low Pressure Plasma Spraying
Authors: Chen H.C. , Heberlein J. , Yoshida T. 
Published: May 2021

Abstract
A new plasma spray process was developed for the rapid deposition of very dense electrolyte layers for solid oxide fuel cells (SOFCs). The dense yttria-stabilized zirconia (YSZ) film was prepared by a center-injection low pressure plasma spraying (CI-VPS) process on various substrates in a triple-torch reactor. For deposition on porous substrates, an intermediate layer was applied using conventional atmospheric plasma spraying (APS) to close the large pores in the substrate. The films were characterized by XRD, SEM, and EMPA. The porosity of the film was analyzed by computerized image analysis of the micrographs. The film was also fractured by four-point bending to characterize the nature of bonding of layer-to-layer and within the deposit. The film analysis showed that YSZ layers with porosities of 0.3 % could be obtained at very high deposition rates with the CI-VPS process, with a very good functional performance of the layer as an electrolyte. Building of a complete SOFC by successive deposition of an atmospheric pressure sprayed porous cermet film, the dense YSZ electrolyte layer, and a porous perovskite film is discussed.
Triplex – An Innovative Three-Cathode Plasma Torch
Authors: Zierhut J. , Haslbeck P. , Landes K.D. , Barbezat G. , Muller M. , Schutz M. 
Published: May 2021

Abstract
Dc plasma torches typically use a mixture of inert and molecular gases when spraying high melting powders. The addition of molecular gases increases the enthalpy of plasma jets, but it also produces arc root fluctuations that can cause variations in injected powders. This paper describes an innovative plasma torch system characterized by a long nozzle and three parallel cathodes. The nozzle consists of several electrically insulated rings and a ring-shaped anode. By adding more rings, the arc gap and voltage can be increased along with the enthalpy of the plasma jet. The results of various tests, comparing the spray rates and deposition efficiencies of new and conventional torches, are presented in the paper.
Effect of Spray Parameters on the Plasma in High Pressure Plasma Spraying up to 300 kPa
Authors: Sodeoka S. , Suzuki M. , Inoue T. , Ueno K. 
Published: May 2021

Abstract
his paper examines the influence of nozzle bore diameter and plasma gas flow on the characteristics of plasma torch spraying. Large bore size allows high plasma gas flow rates to be achieved without an excessive increase in voltage, which is apt to damage the cathode. High flow rates (Ar: 1.3x10-3, H2: 1.3x10-4, He: 2.7x10-4 m3/s) are effective in imbuing more power into the plasma without the damage associated with higher chamber pressures. The relationships among key process parameters, including effective plasma power, electrical efficiency, chamber pressure, and plasma gas flow, are expressed qualitatively in the paper based on multiple regression analysis.
Electron Beam Post-Treatment of Coatings Plasma Sprayed onto Magnesium Alloys
Authors: Wielage B. , Fleischer K. 
Published: May 2021

Abstract
Magnesium alloys are widely used as lightweight metals in cars and trucks, but they require special surface treatments to offset corrosion and wear limitations. One such treatment, electron beam remelting, is the focus of this present work. As described in the paper, copper and nickel powders were plasma sprayed onto magnesium in a vacuum chamber, then heated to melting temperatures with a swept electron beam. Copper and nickel were chosen because they form hard intermetallic compounds when melted with magnesium. The structure and properties of the remelted Cu- or Ni-alloyed surface layer were found to be dependent on the properties of the plasma sprayed coating and the parameters of the e-beam treatment. In the course of the investigation, the coatings were assessed based on their microstructure, the thickness of the remelting zone, occurring phases, and the determination of hardness and abrasive wear resistance.
Role of Atmosphere During Plasma Processing for Application to Plasma Spraying of Aluminum onto Polyethyleneterephtalate (PET)
Authors: Hubert H. , Blein F. , Freslon A. , Jeandin M. , Le Paven C. , Houdy P. 
Published: May 2021

Abstract
Polymeric substrates must be effectively cooled during plasma spraying to limit detrimental effects due to heat flow from the plasma jet. Even with the use of auxiliary cooling systems, however, some polymer substrates can undergo superficial modifications caused by particle heating at impact. This paper deals with chemical modifications in PET as a function of surrounding atmospheres during plasma processing. It also explains how aluminum coating adhesion was determined using tensile tests.
Heating and Acceleration of Ceramic Particles in 20-kA Pulsed Plasma
Authors: Miyamoto M. , Sakuta T. , Tago M. 
Published: May 2021

Abstract
In this paper, the authors evaluate a pulsed plasma spraying process for producing ceramic coatings. Experiments were conducted with a specially developed torch with a discharge current of 24 kA and a pulse duration of 400 μs. The in-flight characteristics of alumina particles injected into the pulsed plasma stream were measured and analyzed. The surface temperature of alumina particles reached 2,700 to 3,300 K, which is well above the melting point. Particle velocity was found to be around 200 m/s, which is comparable to particle velocity in dc plasma streams. Coatings formed with one shot of pulsed plasma were examined using scanning electron microscopy, and the results confirm the applicability of pulsed plasma to the spraying of refractory materials.
High Heat Flux Thermal Cycling of Multi-Layered Deposits Using a HVOF Gun: Modelisation and Experiments
Authors: Verdy C. , Riad H. , Raviart O. , Abboudl S. , Coddet C. , Cornu D. , De Monicault J.-M. 
Published: May 2021

Abstract
The aim of this work was to determine the behavior of multi-layered structures under high heat fluxes. A direct simulation by the implicit finite difference method was used to predict the transient temperature distribution in each layer of the multimaterial. The influence of the thickness of layers was also studied. Experimentally, high heat fluxes were produced using a HVOF gun operated with a methane-oxygen mixture and internally cooled samples. Multi-layered deposits were vacuum plasma sprayed onto a copper block containing coolant channels for a circulation of water. Transient and static tests were performed with heat fluxes up to 100 MW/m2 and durations of a few minutes to several hours.
Phase Composition Changes in Plasma Sprayed Zircon-Alumina Tubes
Authors: Dubsky J. , Kolman B.J. , Buchal A. 
Published: May 2021

Abstract
Protective tubes ( Ø 90x1500 mm) were manufactured by spraying with a water stabilized plasma gun. Mixtures of zircon (ZrSiO4) and alumina (Al2O3) were used as feedstock powders. Products made of these powders exhibit very good properties during thermal cycling. Previous results of the phase composition and phase changes were obtained from as-sprayed and annealed samples using X-ray diffractometry (XRD) and scanning electron microscopy. During plasma spraying zircon decomposed into ZrO2 and SiO2, which on impact and after rapid quenching formed a very fine eutectic mixture of tetragonal or monoclinic ZrO2 and amorphous SiO2. During this process alumina, in feedstock as α-phase (corundum), formed the spinel γ-phase. On annealing the y-phase transformed into the a-phase, whereas amorphous SiO2 crystallized and reacted with tetragonal ZrO2 to form ZrSiO4. Mullite (3Al2O3.2SiO2) was found at the highest annealing temperature of 1500°C when alumina reacted with SiO2. High temperature XRD was used for direct observation of phase changes during heating and cooling between room temperature and 1500°C in powdered as-sprayed deposits. This method confirmed the phase changes observed at room temperature in annealed samples, in particular the partial transformation of tetragonal to monoclinic ZrO2.
Stress Intensity Factors for Interfacial Cracks in Thick Thermal Barrier Coatings
Authors: Bjerken C. , Persson C. 
Published: May 2021

Abstract
A straight-forward method for calculating the stress intensity factors (or the energy release rate and mode mixity) for interfacial cracks in bi-materials has been developed. An existing method for homogeneous materials, based on the computation of the energy release rate from the nodal forces and displacements given by a finite element analysis, was modified to include the mismatch in material properties. Thick thermal barrier coatings usually fail as a result of cracking near the interface. The influence of the thickness and the edge angle of the coating on the energy release rate and mode mixity for a small edge crack at the interface of a TBC system subjected to thermal loading was investigated. It was established that the high energy release rates obtained for thick coatings can be reduced by decreasing the edge angle of the coating. Additionally a comparison with energy release rates given by J-integral computations has been done.
Anterior sacral meningocele repair assisted by intraoperative intrathecal fluorescence and 3D printing model: illustrative case
Authors: Yeh Yu-Chaing , Lin Ya-Jui , Yeh Chih-Hua , Hsieh Pao-Shiu , Wu Chieh-Tsai 
Published: May 2021

BACKGROUND
Marfan syndrome is rarely accompanied by anterior sacral meningocele (ASM) resulting from erosion of the sacrum by dural ectasia. ASM may induce symptoms due to severe mass effects. ASM may also mimic ovarian cysts, and the risk of cerebrospinal fluid (CSF) leakage is high if spontaneous rupture of the cyst occurs. In this study, the authors presented a rare case of ASM with iatrogenic CSF leakage in a 34-year-old woman with suspected Marfan syndrome.

OBSERVATIONS
The patient initially presented with a giant ASM that was first misdiagnosed as an ovarian cyst. Previously, it had been partially resected, which was followed by iatrogenic CSF leakage. Symptoms of intracranial hypotension, including postural headache and dizziness, developed within 1 month. Brain magnetic resonance imaging (MRI) showed pituitary enlargement, bilateral subdural effusion, and tonsillar herniation. Preoperative computed tomography myelography provided three-dimensional (3D) examination of the deformed sacrum and CSF leakage site. Transabdominal approaches led to primary repair, and repair of the meningocele was achieved by intraoperative fluorescein fluorescence and 3D printed model–guided polymethyl methacrylate bone cement reconstruction. No CSF leakage or recurrent ASM was found at the 1.5-year follow-up visit.

LESSONS
Intraoperative intrathecal fluorescence and 3D-printed models are useful for ASM repair. Preoperative MRI is helpful for differentiating ASM from other causes of a huge pelvic mass, including ovarian cyst.
A retro-odontoid pseudotumor treated with fixation and tumor resection by the lateral approach: illustrative case
Authors: Oda Yoshiaki , Tokioka Takamitsu , Ozaki Toshifumi 
Published: May 2021

BACKGROUND
A retro-odontoid pseudotumor is not a condition that requires resection. However, pathological diagnosis is required when a tumor such as a meningeal tumor or chordoma is suspected. The authors report a case of a large lesion treated with posterior fixation and tumor resection using a lateral approach.

OBSERVATIONS
A 77-year-old man visited the authors’ department complaining of neck pain and decreased dexterity of the upper extremities. Magnetic resonance imaging showed a large, beak-shaped lesion behind the dens and severe compression of the spinal cord. Surgery consisted of occipitocervical–C2 fixation, followed by tumor resection with a left lateral approach. The pathological diagnosis was consistent with a retro-odontoid pseudotumor. The tumor was resected to a relatively large extent and shrank over time, leading to complete disappearance.

LESSONS
Pathological examination is also possible with a posterior approach if the tumor can be reached through the lateral edge of the dura. In that situation, the amount of resection is limited, and there is a risk of spinal cord compression. Intradural dissemination of tumors is a concern with the transdural approach. If tumor resection by the posterior approach is difficult, the lateral approach can facilitate tumor resection.
Spinal arthrodesis via lumbar interbody fusion without direct decompression as a treatment for recurrent radicular pain due to epidural fibrosis: patient series
Authors: Swong Kevin , Strong Michael J. , Nathan Jay K. , Yee Timothy J. , Smith Brandon W. , Park Paul , Oppenlander Mark E. 
Published: May 2021

BACKGROUND
Lumbar radiculopathy is the most common indication for lumbar discectomy, but residual postoperative radicular symptoms are common. Postoperative lumbar radiculopathy secondary to scar formation is notoriously difficult to manage, with the mainstay of treatment focused on nonoperative techniques. Surgical intervention for epidural fibrosis has shown unacceptably high complication rates and poor success rates.

OBSERVATIONS
Three patients underwent spinal arthrodesis without direct decompression for recurrent radiculopathy due to epidural fibrosis. Each patient previously underwent lumbar discectomy but subsequently developed recurrent radiculopathy. Imaging revealed no recurrent disc herniation, although it demonstrated extensive epidural fibrosis and scar in the region of the nerve root at the previous surgical site. Dynamic radiographs showed no instability. Two patients underwent lateral lumbar interbody fusion, and one patient underwent anterior lumbosacral interbody fusion. Each patient experienced resolution of radicular symptoms by the 1-year follow-up. Average EQ visual analog scale scores improved from 65 preoperatively to 78 postoperatively.

LESSONS
Spinal arthrodesis via lumbar interbody fusion, without direct decompression, may relieve pain in patients with recurrent radiculopathy due to epidural fibrosis, even in the absence of gross spinal instability.
Muscle: 50+ Years of Electron Microscopy
Authors: Franzini-Armstrong Clara 
Published: May 2021

This project was initiated with the aim of preserving for the future a portion of the extensive muscle ultrastructural image archive accumulated over a 50 year period by the author and her laboratory. Between the late 1950s and current times electron microscopy (EM) evolved. The early EM revealed the ultrastructural identification and definition of cell organelles and laid the foundation for cell biology. This continues with he discovery of new structural organizations and organelles. Currently EM images provide the essential basis for identification of structural changes associated with mutational experiments and newly discovered pathology. The most recent development of techniques allowing near atomic level of resolution brings microscopy to modern times. This evolution has been greatly enriched by the rebirth of light microscopy, fueled by dynamic views of events based on video techniques, by the availability of specific targeting of cell components and by confocal microscopy that allows 3-D structural reconstructs. Correlation between light and electron microscopy, when appropriately done, is highly revealing.

The images in this publication present descriptive and structure-function correlations covering the whole animal kingdom with some areas more extensively illustrated than others. The first part classifies the images based in their site of origin, the second part identifies functional correlations, the third part introduces results of mutational experiments, the fourth part covers aging and pathology examples, the fifth part is a guide to the techniques. The images are presented with a numerical identification correlated with a very succinct description. References are limited to the directly relevant published material from the author’s laboratory that are helpful in extending the limited legends and in assigning contributions. With very few exceptions, references to the literature are not given. The author asks for the forgiveness of the many friends, trainees, collaborators and competitors whose contributions and priorities are not recognized.

The work has been stimulated by interactions with teachers and advisors. Keith R. Porter, father of the endoplasmic reticulum and sarcoplasmic reticulum instilled admiration for Nature’s work and was always been a guiding light in the author’s work. Richard J. Podolsky and Andrew F. Huxley taught the importance of structural correlations. Past and present trainees and collaborators, whose names appear in the reference list, have added depth of understanding.

In the case of skeletal muscle much necessary information is gained by using the muscle bible: “Myology”, A.G. Engel and C. Franzini-Armstrong, Eds. 3rd Edition, McGraw Hill, N.Y. 2004.
EVALUASI KINERJA STRUKTUR GEDUNG BETON BERTULANG METODE PUSHOVER ANALYSIS
Authors: Aswar Junaidin 
Published: May 2021

Quest Hotel yang terletak di Yogyakarta merupakan bangunan tempat tinggal yang di peruntukan untuk para pengunjung wisata maupun orang-orang yang punya kepentingan lain yang datang di Yogyakarta, bangunan ini merupakan bangunan bertingkat 10 lantai serta memiliki ketinggian 33,45 m. Sebuah struktur bangunan harus direncanakan sesuai dengan kaidah-kaidah perencanaan yang berlaku, sehingga dampak yang disebabkan oleh gempa dapat menahan guncangan yang telah direncanakan. Penelitian ini dilakukan dengan tujuan untuk mengetahui nilai gaya lateral maksimal serta displacement yang terjadi pada gedung dan bagaimana level kinerja berdasarkan metode FEMA 356. Besarnya gaya lateral maksimum pada arah x = 8034,753 kN pada step 9 dengan displacement sebesar -0,042530 m dan pada arah y gaya lateral maksimum = 7055,847 kN pada step 7 dengan displacement sebesar -0,066046 m. Hal ini menunjukan bahwa struktur gedung lebih kuat menahan gaya lateral dari arah-x dibandingkan dari arah-y. Berdasarkan hasil perhitungan analisis static non-linier, dari nilai target perpindahan maka diperoleh nilai drift aktual arah-x = 0,00484 (0,484%) dan nilai drift actual arah-y = 0,00773 (0,73%). Hal ini menunjukkan bahwa bangunan tidak mengalami kerusakan komponen struktur. Kekuatan dan kekakuan gedung masih hampir sama dengan kondisi sebelum struktur dilanda gempa, pada keadaan ini gedung yang ditinjau adalah termasuk pada level kinerja Immediate Occupancy (IO). Kata Kunci: Displacement, FEMA 356, Pushover, Quest Hotel.
PENGARUH PENGGUNAAN ABU SABUT KELAPA SAWIT SEBAGAI BAHAN PENGGANTI SEBAGIAN SEMEN TERHADAP KUAT TEKAN PAVING BLOCK
Authors: Firdaus Wahyu , Afrizal Yuzuar , Gunawan Agustin 
Published: May 2021

The Oil palm fiber ash has a silica content of 59.1% which make it possible as a partial replacement for cement. This research was aimed to determine the effect of oil palm fiber ash as a partial replacement of cement to compressive strength of paving block. The specimens was made with a size of 20 cm x 10 cm x 6 cm and used a ratio of 1 cement: 3 sand with the variations of the substitution of 0%, 2.5%, 5%, 7.5%, 10%, 12.5% and 15% of the volume cement. The water requirement used the initial flow test according to SNI 03-6882-2002 with each variation had the same amount of water. Specimens printed were soaked in a soaking tub at the age of 1 day for 12 days, then cut into cubes of 5 cm all side using a grinder. The testing of the compressive strength was done at the age of 14 days. Results of the average compressive strength in variations of 0%, 2.5%, 5%, 7.5%, 10%, 12.5%, 15% were respectively 15,13 MPa, 15,36 MPa, 16,02 MPa, 12,97 MPa, 12,16 MPa, 10.00 MPa and 8.01 MPa. The test results showed that the highest increase occurred on the replacement variation of 5% (5.85% from normal paving block) and the maximum decrease occurred on the replacement variation of 15% which was equal to - 47.09% from the normal paving block. The results of the research indicate that the partial replacement of cement with oil palm fiber ash above 5% of the cement volume decreased the compressive strength of paving block. Keywords : oil palm fiber ash, compressive strength, paving block.