Reaction Mechanisms in Organic Binder Removal During Ceramic Processing: PMMA/Cordierite as a Prototype System

1987 ◽  
Vol 108 ◽  
Author(s):  
William E. Farnethe ◽  
Ralph H. Staley ◽  
Theodore Budzichowski
Keyword(s):  
Small Molecules ◽  
Tape Casting ◽  
Prototype System ◽  
Extensive Literature ◽  
Ceramic Processing ◽  
Binder Removal ◽  
Performance Requirements ◽  
Ceramic Surfaces ◽  
Ceramic Components ◽  
Materials Used

As the performance requirements of ceramic components are refined, the demands placed on the materials used in their processing also become more stringent. For example, in advanced ceramic packaging applications, it is increasingly important that the organic polymers used as binders be capable of degradation and removal at low temperatures and in non-oxidizing atmospheres. This paper examines the chemistry that can occur during two fundamental stages of the binder removal process, (1) the breakdown of the C–C backbone of the polymer during pyrolysis, and (2) the interaction of the small molecules that are produced during pyrolysis with ceramic surfaces. The work has focused on acrylate and methacrylate systems, both because this is an important family of polymers for applications in tape casting, and because there is a relatively extensive literature on their pyrolysis chemistry.

Microwave Dielectric Ceramics and Devices for Wireless Technologies

2008 ◽  
Vol 368-372 ◽  
pp. 154-158
Author(s):  
Zhao Xian Xiong ◽  
X. Xue ◽  
Hong Qiu ◽  
C. Zhang ◽  
C. Fang ◽  
...  
Keyword(s):  
Quality Factor ◽  
Large Scale ◽  
Tape Casting ◽  
Solution Synthesis ◽  
Microwave Ceramics ◽  
Synthesis Techniques ◽  
Microwave Dielectric ◽  
Ceramic Components ◽  
Co Precipitation ◽  
Low Permittivity

In this paper, several kinds of synthesis techniques were adopted; not only conventional solidstate reaction method but also solution synthesis techniques, including co-precipitation and hydrothermal synthesis, in addition to the gel-casting for complex shape of ceramic components and tape-casting of large scale thin plate for microwave IC. Different kinds of microwave ceramics were prepared, such as materials with low permittivity and high quality factor, moderate permittivity and good quality factor, and, high permittivity and reasonable quality factor, in addition to near zero of temperature coefficient of resonance frequency. Series of microwave devices were developed, for examples, dielectric resonators, dielectric filters, GPS antennas, communication connectors, and thin substrates for microwave IC.

scholarly journals Small Molecules Acting on Myofilaments as Treatments for Heart and Skeletal Muscle Diseases

2020 ◽  
Vol 21 (24) ◽  
pp. 9599
Author(s):  
Khulud Alsulami ◽  
Steven Marston
Keyword(s):  
Small Molecules ◽  
High Throughput Screening ◽  
Pathological Condition ◽  
Treatment Options ◽  
Cardiac Contractility ◽  
Left Ventricular ◽  
Phase Iii ◽  
Extensive Literature ◽  
Therapeutic Value ◽  
Omecamtiv Mecarbil

Hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM) are the most prevalent forms of the chronic and progressive pathological condition known as cardiomyopathy. These diseases have different aetiologies; however, they share the feature of haemodynamic abnormalities, which is mainly due to dysfunction in the contractile proteins that make up the contractile unit known as the sarcomere. To date, pharmacological treatment options are not disease-specific and rather focus on managing the symptoms, without addressing the disease mechanism. Earliest attempts at improving cardiac contractility by modulating the sarcomere indirectly (inotropes) resulted in unwanted effects. In contrast, targeting the sarcomere directly, aided by high-throughput screening systems, could identify small molecules with a superior therapeutic value in cardiac muscle disorders. Herein, an extensive literature review of 21 small molecules directed to five different targets was conducted. A simple scoring system was created to assess the suitability of small molecules for therapy by evaluating them in eight different criteria. Most of the compounds failed due to lack of target specificity or poor physicochemical properties. Six compounds stood out, showing a potential therapeutic value in HCM, DCM or heart failure (HF). Omecamtiv Mecarbil and Danicamtiv (myosin activators), Mavacamten, CK-274 and MYK-581 (myosin inhibitors) and AMG 594 (Ca2+-sensitiser) are all small molecules that allosterically modulate troponin or myosin. Omecamtiv Mecarbil showed limited efficacy in phase III GALACTIC-HF trial, while, results from phase III EXPLORER-HCM trial were recently published, indicating that Mavacamten reduced left ventricular outflow tract (LVOT) obstruction and diastolic dysfunction and improved the health status of patients with HCM. A novel category of small molecules known as “recouplers” was reported to target a phenomenon termed uncoupling commonly found in familial cardiomyopathies but has not progressed beyond preclinical work. In conclusion, the contractile apparatus is a promising target for new drug development.

scholarly journals Digital image display station performance requirements based on physician experience with a prototype system

1989 ◽  
Vol 2 (3) ◽  
pp. 150-155 ◽  
Author(s):  
Paul Fisher ◽  
Brent Grover ◽  
Gerhard Brauer ◽  
Gordon Ritchie
Keyword(s):  
Digital Image ◽  
Image Display ◽  
Prototype System ◽  
Performance Requirements ◽  
Display Station

Development of Stabilizer Selection Tables for Low-Volume Roads: Arlington, Texas

2003 ◽  
Vol 1819 (1) ◽  
pp. 85-94 ◽  
Author(s):  
Martin Phillips ◽  
Anand J. Puppala ◽  
Keith Melton
Keyword(s):  
Construction Projects ◽  
Soil Stabilization ◽  
Task Force ◽  
Expansive Soil ◽  
Evaluation Process ◽  
Extensive Literature ◽  
Treatment Methods ◽  
Subgrade Soils ◽  
Low Volume ◽  
Materials Used

Expansive soil movements cause damage to low-volume traffic roadways, which is attributed to the low rigidity of the materials used in the pavements. Several treatment methods have been used to stabilize expansive, soft subsoils, which have yielded mixed results due to the presence of sulfates. Because of the ambiguity of these results, the city of Arlington, Texas, established a task force of researchers and practitioners in the area of soil stabilization to develop matrix tables of the various treatment methods and their applicability to stabilize expansive, soft, and sulfate-rich soils. Extensive literature compiled on the stabilizers, several new and previous research studies on stabilizers, and the expertise of the task group members were considered in the evaluation process. The task force developed seven matrix-form selection tables that showed various treatment methods and if their applications were acceptable or unacceptable for the 12 types of soft and sulfate-rich subgrade soils. A summary of the tables was prepared, along with guidelines on how to use these tables to screen the potential stabilizers for pavement construction projects.

scholarly journals Reduction of Core-loss in the High Frequency Band of the Fe-Si-Cr Crystalline Alloy According to Particle Size

2021 ◽  
Author(s):  
Yeon Jun Choi ◽  
Ji Hun Ahn ◽  
Deok Hyeon Kim ◽  
Ye Rae Kim ◽  
Bo Wha Lee
Keyword(s):  
Particle Size ◽  
High Performance ◽  
Raw Materials ◽  
Core Loss ◽  
Magnetic Saturation ◽  
Magnetic Composites ◽  
Performance Requirements ◽  
Materials Used ◽  
Average Size ◽  
The Relationship

Abstract In order for soft magnetic composites (SMCs) to achieve the high-performance requirements expected of them even at high frequencies, high permeability and low core-loss are required. In this study, we used different sizes of gas atomized Fe-Si-Cr alloy powder to produce SMCs, this alloy has higher resistivity than existing materials used in SMCs such as Fe-Si alloy or pure Fe. These powders were prepared by sieving raw materials which had an average size from less than 25 µm to over 63 µm. Our experiments show that as particle size decreases, the magnetic saturation tends to increase, the sample made from the powder with particles 25-38 µm in size recorded the highest magnetic saturation of 169.38 emu/g. Additionally, as particle size decreased, permeability increased. The sample made from powder with particles under 25 µm had a permeability of 20.7 H/m at 1 MHz. Also, the relationship between particle size and quality factor was found to be inversely proportional. Finally, the minimum core-loss was 187.26 kW/m3 at 1 MHz for the sample made from powder whose constituent particles are under 25 µm. We also observed that the core-loss is proportional to particle size.

Targeting Negative Regulators of TRIF-dependent TLR Signaling Pathway as a Novel Therapeutic Strategy

2019 ◽  
Vol 14 (1) ◽  
pp. 49-54
Author(s):  
P. Mosaddeghi ◽  
N. Nezafat ◽  
M. Negahdaripour ◽  
M. Eslami ◽  
Y. Ghasemi
Keyword(s):  
Small Molecules ◽  
Signaling Pathway ◽  
Inflammatory Diseases ◽  
Adaptor Protein ◽  
Extensive Literature ◽  
Negative Regulators ◽  
Tlr Agonists ◽  
Microbial Infections ◽  
Proinflammatory Responses ◽  
And Function

Background: Toll-Like Receptors (TLRs) are a subclass of pathogen-associated molecular patterns (PAMPs). There is a growing interest in the use of TLR agonists for various pathological dysfunctions, including cancer, microbial infections, and inflammatory diseases. TLR3/4 agonists that can induce TIR-domain-containing adapter-inducing interferon-β (TRIF)- dependent pathway have shown fewer toxic immunostimulatory responses in comparison to other small molecules. Furthermore, TLR3 agonists indicate promising anti-tumor potential in cancer immunotherapy either as vaccine adjuvant or monotherapy. </P><P> Objective: It is logical to assume that the induction of the genes that are involved in TRIF pathway to augment their pleiotropic effects on different cells via TLR agonists, could enhance the treatment process of disease while minimizing the toxicity related to using other small molecules. Methods: An extensive literature search to identify the negative regulators of TRIF-dependent signaling pathway and their biological functions was performed from two databases PubMed and Scopus. Results: Negative regulators of TRIF signaling pathways were identified. In addition, structure and function of sterile α- and armadillo-motif containing protein (SARM), the only TIR domaincontaining adaptor protein that inhibits TRIF-dependent activation, were briefly reviewed. Conclusion: We proposed that the manipulation of TRIF signaling pathway via targeting its negative regulators could be used as an approach to modulate the functions of this pathway without undesired toxic proinflammatory responses.

scholarly journals Nitinol Type Alloys General Characteristics and Applications in Endodontics

Processes ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 101
Author(s):  
Leszek A. Dobrzański ◽  
Lech B. Dobrzański ◽  
Anna D. Dobrzańska-Danikiewicz ◽  
Joanna Dobrzańska
Keyword(s):  
Development Strategy ◽  
Swot Analysis ◽  
Extensive Literature ◽  
Processing Conditions ◽  
Atomic Concentration ◽  
Root Canals ◽  
The Development Strategy ◽  
Materials Used ◽  
Selection Of

A very extensive literature review presents the possibilities and needs of using, in endodontics, the alloys commonly known as nitinol. Nitinol, as the most modern group of engineering materials used to develop root canals, is equilibrium nickel and titanium alloys in terms of the elements’ atomic concentration, or very similar. The main audience of this paper is engineers, tool designers and manufacturers, PhD students, and students of materials and manufacturing engineering but this article can also certainly be used by dentists. The paper aims to present a full material science characterization of the structure and properties of nitinol alloys and to discuss all structural phenomena that determine the performance properties of these alloys, including those applied to manufacture the endodontic tools. The paper presents the selection of these alloys’ chemical composition and processing conditions and their importance in the endodontic treatment of teeth. The results of laboratory studies on the analysis of changes during the sterilization of endodontic instruments made of nitinol alloys are also included. The summary of all the literature analyses is an SWOT analysis of strengths, weaknesses, opportunities, and threats, and is a forecast of the development strategy of this material in a specific application such as endodontics.

scholarly journals Comparative Study of Architecture of the Great Mosque at Samarra, Iraq and Ibn Tulun Mosque at Cairo, Egypt

2020 ◽  
Vol 10 (2) ◽  
Author(s):  
Zahid Tauqeer Ahmad ◽  
Seemin Aslam
Keyword(s):  
Literature Review ◽  
Building Materials ◽  
Extensive Literature ◽  
Construction Technology ◽  
Islamic Architecture ◽  
Built Form ◽  
Dominant Feature ◽  
Materials Used ◽  
Form Type ◽  
Building Form

Ever since the emergence of Islam, mosque has always been the most dominant feature in any Islamic built environment. Over the course of time, mosque architecture has gone through a process of various forms of uses and expressions in terms of its transformation. Its style, layout, building form, type of ornamentation used, building materials and construction technology usually provide vital information not only about the practice of Islam in general but also about the timeline, prevailing geopolitical environment, religious conviction, purpose, need and the region in which the mosque was built. This research paper emphasizes the study of the general characteristics of the two earliest examples of mosques in Islamic architecture through extensive literature review. It also highlights the historical and geopolitical context, built form, size, shape, configuration, color, texture, materials used, scale and type of decorative elements of the two most outstanding and heavily restored mosques to date.

scholarly journals Conflict Resolution for Product Performance Requirements Based on Propagation Analysis in the Extension Theory

2014 ◽  
Vol 6 ◽  
pp. 589345 ◽  
Author(s):  
Yanwei Zhao ◽  
Huanhuan Hong ◽  
Gaochao Jiang ◽  
Weigang Chen ◽  
Hongwei Wang
Keyword(s):  
Extension Theory ◽  
Strategy Development ◽  
Prototype System ◽  
Performance Requirements ◽  
Static Data ◽  
Propagation Analysis ◽  
Before And After ◽  
Compressor Performance ◽  
Intake Pressure ◽  
Design Conflicts

Traditional product data mining methods are mainly focused on the static data. Performance requirements are generally met as possible by finding some cases and changing their structures. However, when one is satisfied with the structures changed, the other effects are not taken into account by analyzing the correlations; that is, design conflicts are not identified and resolved. An approach to resolving the conflict problems is proposed based on propagation analysis in Extension Theory. Firstly, the extension distance is improved to better fit evaluating the similarity among cases, then, a case retrieval method is developed. Secondly, the transformations that can be made on selected cases are formulated by understanding the conflict natures in the different performance requirements, which leads to the extension transformation strategy development for coordinating conflicts using propagation analysis. Thirdly, the effects and levels of propagation are determined by analyzing the performance values before and after the transformations, thus the co-existing conflict coordination strategy of multiple performances is developed. The method has been implemented in a working prototype system for supporting decision-making. And it has been demonstrated the feasible and effective through resolving the conflicts of noise, exhaust, weight and intake pressure for the screw air compressor performance design.

Piezoelectric component fabrication using projection-based stereolithography of barium titanate ceramic suspensions

2017 ◽  
Vol 23 (1) ◽  
pp. 44-53 ◽  
Author(s):  
Xuan Song ◽  
Zeyu Chen ◽  
Liwen Lei ◽  
Kirk Shung ◽  
Qifa Zhou ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Manufacturing Process ◽  
Ferroelectric Properties ◽  
Tape Casting ◽  
Prototype System ◽  
Ultrasound Transducers ◽  
Post Processing ◽  
Projection System ◽  
Content Type ◽  
Ceramic Suspensions

Purpose Conventional machining methods for fabricating piezoelectric components such as ultrasound transducer arrays are time-consuming and limited to relatively simple geometries. The purpose of this paper is to develop an additive manufacturing process based on the projection-based stereolithography process for the fabrication of functional piezoelectric devices including ultrasound transducers. Design/methodology/approach To overcome the challenges in fabricating viscous and low-photosensitive piezocomposite slurry, the authors developed a projection-based stereolithography process by integrating slurry tape-casting and a sliding motion design. Both green-part fabrication and post-processing processes were studied. A prototype system based on the new manufacturing process was developed for the fabrication of green-parts with complex shapes and small features. The challenges in the sintering process to achieve desired functionality were also discussed. Findings The presented additive manufacturing process can achieve relatively dense piezoelectric components (approximately 95 per cent). The related property testing results, including X-ray diffraction, scanning electron microscope, dielectric and ferroelectric properties as well as pulse-echo testing, show that the fabricated piezo-components have good potentials to be used in ultrasound transducers and other sensors/actuators. Originality/value A novel bottom-up projection system integrated with tape casting is presented to address the challenges in the piezo-composite fabrication, including small curing depth and viscous ceramic slurry recoating. Compared with other additive manufacturing processes, this method can achieve a thin recoating layer (as small as 10 μm) of piezo-composite slurry and can fabricate green parts using slurries with significantly higher solid loadings. After post processing, the fabricated piezoelectric components become dense and functional.

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