scholarly journals Optical Glass: A High-Tech Base Material as Key Enabler for Photonics

2018 ◽  
Author(s):  
Uwe Petzold
Keyword(s):  
Optical Glass ◽  
Base Material ◽  
High Tech

Experimental Study on the Comparison of Resisting Semi-Armour-Piercing Projectile Penetration Ability for Steel Mesh, Steel Fiber and Steel Composites

2012 ◽  
Vol 253-255 ◽  
pp. 425-431
Author(s):  
Yun Feng Wang ◽  
Yao Hua Wang
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Base Material ◽  
High Tech ◽  
Protective Material ◽  
Comparative Tests ◽  
Steel Reinforced Concrete ◽  
Steel Mesh ◽  
Penetration Ability ◽  
Weapon Development

A new protective material-steel mesh reinforced concrete was developed under the condition of modern high-tech weapon development. The comparative tests were conducted with steel fiber reinforced and steel reinforced concrete. The enhancement characteristics of three composites were analyzed in the respects of base material, the distribution of reinforced material and its bonding. The results indicate that steel mesh reinforced concrete is the most effective composite resisting penetration.

Linear Friction Welding of a Forged Near-α Titanium Alloy

2012 ◽  
Vol 706-709 ◽  
pp. 211-216 ◽  
Author(s):  
E. Dalgaard ◽  
Priti Wanjara ◽  
Javad Gholipour ◽  
John J. Jonas
Keyword(s):  
Titanium Alloy ◽  
Friction Welding ◽  
Creep Resistance ◽  
Electron Backscatter Diffraction ◽  
Weld Zone ◽  
Base Material ◽  
High Tech ◽  
Linear Friction Welding ◽  
Linear Friction ◽  
Backscatter Diffraction

IMI834 (Ti-5.8Al-4Sn-3.5Zr-0.7Nb-0.5Mo-0.35Si) is a high-tech near-α titanium alloy with improved creep resistance and mechanical property retention at temperatures up to 600°C [1]. It is used in the aerospace industry for compressor disks and blades due to its excellent balance between creep resistance and fatigue strength [2]. The linear friction welding (LFW) behaviour of IMI834 displaying an initial bimodal α+β microstructure was investigated using varying axial pressures during welding. Electron backscatter diffraction (EBSD) was used to characterize the texture and phase fraction of the welded IMI834 samples in the weld zone (WZ) and thermomechanically affected zones (TMAZ) in relation to the base material. Based on microhardness evaluation of the weldments, the WZ was determined to be slightly harder than the base material.

Nanostructuring of the surface layer by the method of electric-spark alloying

2020 ◽  
pp. 113-121 ◽  
Author(s):  
Elizaveta Yu. Kudryashova ◽  
Ivan A. Shamberov ◽  
Roman N. Zadoroznyy
Keyword(s):  
Mechanical Properties ◽  
Surface Layer ◽  
Base Material ◽  
Surface Profile ◽  
Carbon Steels ◽  
Research Purpose ◽  
Elemental Content ◽  
High Tech ◽  
Urgent Task ◽  
Processing Modes

The creation of a universal, economical and high-tech way of increasing the life of both worn and new parts has become an urgent task. Such methods include nanostructuring of surface coatings, which can be performed by electric spark alloying. (Research purpose) The research purpose is studying the possibilities of electric spark alloying in the nanostructuring of the surface layer of carbon steels. (Materials and methods) The authors conducted study of the surface layer of 35-carbon steel with coatings obtained by electric spark alloying on the BIG-1 installation with different materials (Cu, Zn, W and WC) and at different modes. To study the surface layer, the elemental content was studied by x-ray fluorescence spectroscopy, the surface profile was studied by profiling, metallographic studies and microhardness measurements. (Results and discussion) The authors revealed that the chemical composition of the alloying electrode and treatment modes have a direct impact on the saturation of the surface layer with alloying elements, the parameters of the profile of the treated surface, the continuity and mechanical properties of the coating. It was found that harder processing modes increase productivity, but reduce mechanical properties. It was also found that the modified structure of the base material contains nanostructured elements because of electroscopic alloying. A sharp increase in the mechanical properties of the coating material allows suggesting that elements of the nanostructural range are present in the coating. (Conclusion) The conducted research shows that the method of electroscopic alloying can be used for nanostructuring of the surface layer of carbon steels.

Study on Surface Quality of BK7 Optical Glass by Longitudinal Torsional Composite Ultrasonic Vibration Milling

2020 ◽  
Vol 984 ◽  
pp. 51-57
Author(s):  
Ya Jian Ma ◽  
Wen Zhong Nie ◽  
Jian Min Lu ◽  
Huan Chen
Keyword(s):  
Surface Quality ◽  
Ultrasonic Vibration ◽  
Optical Glass ◽  
Spindle Speed ◽  
High Tech ◽  
Processing Efficiency ◽  
Machined Surface ◽  
Ultrasonic Milling ◽  
Vibration Milling

BK7 optical glass has been widely used in modern high-tech fields such as aerospace, automotive, optical precision instruments, electronic information, etc. due to its excellent performance, but its gap between plasticity and hardness is huge, making traditional machining easy to appear sub-surface. Damage and other phenomena, surface quality is difficult to meet the requirements. In this paper, the ultrasonic milling dynamics model was firstly established, and then the multi-factor method was used to detect the longitudinal torsional composite ultrasonic milling and ordinary milling of BK7 optical glass, and the surface roughness and surface topography of different spindle speed, milling speed and milling depth were analyzed. Finally, the laws and mechanisms affecting the quality of the machined surface were obtained. It is found that the surface quality is best when the spindle speed is 3000r/min and the milling depth is 0.2mm; the surface quality of BK7 optical glass decreases with the increase of milling speed. The surface quality and processing efficiency of BK7 optical glass are improved by longitudinal torsional composite ultrasonic vibration milling, and the optimal process parameters for BK7 optical glass longitudinal torsional ultrasonic milling are provided.

Research on the Laser Welding Technology of GH4169

2014 ◽  
Vol 633-634 ◽  
pp. 703-706 ◽  
Author(s):  
Jia Rui Qi ◽  
Hua Kai Wei ◽  
Dan Feng Zhang ◽  
Li Han
Keyword(s):  
Tensile Strength ◽  
Laser Welding ◽  
Large Range ◽  
Welded Joint ◽  
Pulsed Laser ◽  
Base Material ◽  
High Tech ◽  
High Tensile Strength ◽  
Pulsed Laser Welding ◽  
Welding Technology

Superalloys have a high tensile strength at elevated temperature, a good stability and reliability in a large range of temperatures. Among these superalloys, GH4169 is widely used as thermal components in the turbojet engine. Traditional welding methods are difficult to adapt to the development of high-tech manufacturing. Laser welding plays an important role in superalloys welding field increasingly for its advantages. In this investigation, superalloy GH4169 plate with a thickness of 1mm was welded utilizing the pulsed laser welding and the mechanical properties of the laser welded joints are analyzed. The maximum tensile strength is 928 Mpa, which is close to the base material tensile strength. The welded joint can meet the requirements of users.

Spiritual Healing, Sick Kids and the Law: Inequities in the American Healthcare System

2003 ◽  
Vol 29 (2-3) ◽  
pp. 269-299
Author(s):  
Janna C. Merrick
Keyword(s):  
Medical Science ◽  
Spiritual Healing ◽  
Best Interests ◽  
Legal Rights ◽  
High Tech ◽  
Divine Love ◽  
Religious Minority ◽  
Human Need ◽  
East End ◽  
The Church

Main Street in Sarasota, Florida. A high-tech medical arts building rises from the east end, the county's historic three-story courthouse is two blocks to the west and sandwiched in between is the First Church of Christ, Scientist. A verse inscribed on the wall behind the pulpit of the church reads: “Divine Love Always Has Met and Always Will Meet Every Human Need.” This is the church where William and Christine Hermanson worshipped. It is just a few steps away from the courthouse where they were convicted of child abuse and third-degree murder for failing to provide conventional medical care for their seven-year-old daughter.This Article is about the intersection of “divine love” and “the best interests of the child.” It is about a pluralistic society where the dominant culture reveres medical science, but where a religious minority shuns and perhaps fears that same medical science. It is also about the struggle among different religious interests to define the legal rights of the citizenry.

HREM interface studies in SiC-whisker-reinforced Al2O3 and Si3N4 ceramics

1988 ◽  
Vol 46 ◽  
pp. 734-735
Author(s):  
W. Braue ◽  
R.W. Carpenter ◽  
D.J. Smith
Keyword(s):  
Analytical Data ◽  
Base Material ◽  
High Strength ◽  
Ceramic Composites ◽  
Good Thermal Stability ◽  
All Ceramic ◽  
Sic Whiskers ◽  
Base Composite ◽  
C 30 ◽  
Si3n4 Ceramics

Whisker and fiber reinforcement has been established as an effective toughening concept for monolithic structural ceramics to overcome limited fracture toughness and brittleness. SiC whiskers in particular combine both high strength and elastic moduli with good thermal stability and are compatible with most oxide and nonoxide matrices. As the major toughening mechanisms - crack branching, deflection and bridging - in SiC whiskenreinforced Al2O3 and Si3N41 are critically dependent on interface properties, a detailed TEM investigation was conducted on whisker/matrix interfaces in these all-ceramic- composites.In this study we present HREM images obtained at 400 kV from β-SiC/α-Al2O3 and β-SiC/β-Si3N4 interfaces, as well as preliminary analytical data. The Al2O3- base composite was hotpressed at 1830 °C/60 MPa in vacuum and the Si3N4-base material at 1725 °C/30 MPa in argon atmosphere, respectively, adding a total of 6 vt.% (Y2O3 + Al2O3) to the latter to promote densification.

Microstructure of resistance spot welding of maraging steels

1990 ◽  
Vol 48 (4) ◽  
pp. 900-901
Author(s):  
I. Neuman ◽  
S.F. Dirnfeld ◽  
I. Minkoff
Keyword(s):  
Maraging Steel ◽  
Spot Welding ◽  
Lath Martensite ◽  
Base Material ◽  
Aging Treatment ◽  
High Strength ◽  
Maraging Steels ◽  
Heat Treated ◽  
Current Cycle ◽  
Welding Processes

Experimental work on the spot welding of Maraging Steels revealed a surprisingly low level of strength - both in the as welded and in aged conditions. This appeared unusual since in the welding of these materials by other welding processes (TIG,MIG) the strength level is almost that of the base material. The maraging steel C250 investigated had the composition: 18wt%Ni, 8wt%Co, 5wt%Mo and additions of Al and Ti. It has a nominal tensile strength of 250 KSI. The heat treated structure of maraging steel is lath martensite the final high strength is reached by aging treatment at 485°C for 3-4 hours. During the aging process precipitation takes place of Ni3Mo and Ni3Ti and an ordered solid solution containing Co is formed.Three types of spot welding cycles were investigated: multi-pulse current cycle, bi-pulse cycle and single pulsle cycle. TIG welded samples were also tested for comparison.The microstructure investigations were carried out by SEM and EDS as well as by fractography. For multicycle spot welded maraging C250 (without aging), the dendrites start from the fusion line towards the nugget centre with an epitaxial growth region of various widths, as seen in Figure 1.

Comparative Effects of High-Tech Visual Scene Displays and Low-Tech Isolated Picture Symbols on Engagement From Students With Multiple Disabilities

2019 ◽  
Vol 50 (4) ◽  
pp. 693-702 ◽  
Author(s):  
Christine Holyfield ◽  
Sydney Brooks ◽  
Allison Schluterman
Keyword(s):  
Language Learning ◽  
Augmentative And Alternative Communication ◽  
Visual Analysis ◽  
Multiple Disabilities ◽  
Visual Scene ◽  
Future Research ◽  
High Tech ◽  
Single Subject ◽  
Wide Range ◽  
The Difference

Purpose Augmentative and alternative communication (AAC) is an intervention approach that can promote communication and language in children with multiple disabilities who are beginning communicators. While a wide range of AAC technologies are available, little is known about the comparative effects of specific technology options. Given that engagement can be low for beginning communicators with multiple disabilities, the current study provides initial information about the comparative effects of 2 AAC technology options—high-tech visual scene displays (VSDs) and low-tech isolated picture symbols—on engagement. Method Three elementary-age beginning communicators with multiple disabilities participated. The study used a single-subject, alternating treatment design with each technology serving as a condition. Participants interacted with their school speech-language pathologists using each of the 2 technologies across 5 sessions in a block randomized order. Results According to visual analysis and nonoverlap of all pairs calculations, all 3 participants demonstrated more engagement with the high-tech VSDs than the low-tech isolated picture symbols as measured by their seconds of gaze toward each technology option. Despite the difference in engagement observed, there was no clear difference across the 2 conditions in engagement toward the communication partner or use of the AAC. Conclusions Clinicians can consider measuring engagement when evaluating AAC technology options for children with multiple disabilities and should consider evaluating high-tech VSDs as 1 technology option for them. Future research must explore the extent to which differences in engagement to particular AAC technologies result in differences in communication and language learning over time as might be expected.

AAC Considerations for Individuals With Angelman Syndrome

2015 ◽  
Vol 24 (3) ◽  
pp. 106-113 ◽  
Author(s):  
Stephen N. Calculator
Keyword(s):  
Angelman Syndrome ◽  
Augmentative And Alternative Communication ◽  
High Tech ◽  
Alternative Communication ◽  
Design And Implementation

Purpose To provide an overview of communication characteristics exhibited by individuals with Angelman Syndrome (AS) and special considerations associated with the design and implementation of augmentative and alternative communication (AAC) programs. Method Results of recent studies exploring individuals' uses of AAC are reviewed, with particular emphasis on factors related to individuals' acceptance and successful uses of AAC systems. Results Not applicable Conclusion Despite their inconsistent access to practices previously found to foster individuals' acceptance of AAC systems, individuals with AS demonstrate the ability to use AAC systems, including high-tech AAC devices, successfully.

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