Lock-In Signal Post-Processing Techniques in Infra-Red Thermography for Materials Structural Evaluation

Liposomes have been utilized as a drug delivery system to increase the bioavailability of drugs and to control the rate of drug release at the target site of action. However, the occurrence of self-aggregation, coalescence, flocculation and the precipitation of aqueous liposomes during formulation or storage can cause degradation of the vesicle structure, leading to the decomposition of liposomes. To increase the stability of liposomes, post-processing techniques have been applied as an additional process to liposomes after formulation to remove water and generate dry liposome particles with a higher stability and greater accessibility for drug administration in comparison with aqueous liposomes. This review covers the effect of these techniques including freeze drying, spray drying and spray freeze drying on the stability, physicochemical properties and drug encapsulation efficiency of dry liposomes. The parameters affecting the properties of liposomes during the drying process are also highlighted in this review. In addition, the impact of using a protective agent to overcome such limitations of each process is thoroughly discussed through various studies.

Download Full-text

Post-processing techniques for making reliable measurements from curve-skeletons

Computers in Biology and Medicine ◽

10.1016/j.compbiomed.2016.03.008 ◽

2016 ◽

Vol 72 ◽

pp. 120-131 ◽

Cited By ~ 7

Author(s):

Robert S. Bradley ◽

Philip J. Withers

Keyword(s):

Post Processing ◽

Curve Skeletons ◽

Processing Techniques

Download Full-text

Abstract WP55: Through Thick and Thin: Improved Aspects Grading and Dense Vessel Detection Using Simple Ncct Post-processing

Stroke ◽

10.1161/str.48.suppl_1.wp55 ◽

2017 ◽

Vol 48 (suppl_1) ◽

Author(s):

James W Evans ◽

Sadanand Dey ◽

Muneer Eesa ◽

Prasanna Eswaradass ◽

Ronda Lun ◽

...

Keyword(s):

Maximum Intensity Projection ◽

Improve Patient Care ◽

Weighted Kappa ◽

Slice Thickness ◽

Post Processing ◽

Rater Reliability ◽

Thin Slice ◽

Vessel Detection ◽

Contrast Ct ◽

Processing Techniques

Introduction: Assessing Alberta Stroke Program Early CT Score (ASPECTS) and identifying hyperdense arteries on non-contrast CT (NCCT) are important components of decision-making in acute stroke. Conventional practice uses 5mm averaged slice thickness NCCT for interpretation of these features. We have systematically evaluated several post processing techniques on NCCT to determine if there is improved reliability in identification of ASPECTS and hyperdense artery. Methodology: We assessed four post-processing techniques on NCCT namely (1) 5mm averaged thickness (2) Minimum Intensity Projection (mIP) - 5mm thickness (3) thin slices (0.625mm) and (4) Maximum Intensity Projection (MIP) - 5mm thickness (Figure 1). Three raters (student, fellow and expert) independently assessed 100 NCCT scans from the PRoveIT database. All scans were read at four different times 10-14 days apart. At each time-point the post processing modality was changed and the patient order randomized. Information on side of suspected infarction was provided. Raters were asked to score ASPECTS and identify presence of hyperdense artery at each reading. Inter-rater reliability was assessed using Intra-cluster correlation (ICC) for ASPECTS and weighted kappa (wKap) for hyperdense artery. Results: The highest inter-rater reliability was found with the MIP technique (ICC 0.42; p<0.001), followed by 5 mm average, mIP and thin slice respectively (ICC 0.33, 0.32, 0.20; all p<0.01). Highest agreement for hyperdense vessel detection was noted with thin slice (wKap 0.30; p<0.001) followed by Average, MIPs and mIPs respectively (wKap 0.25, 0.18, 0.13; all p <0.05). Conclusion: The use of MIP images for ASPECTS grading and thin images for hyperdense vessel detection improves reliability on NCCT. These simple processing steps are easily available on any modern scanner and may help improve patient care.

Download Full-text

Laboratory Infra-Red Thermal Assessment of Laser-Sintered High-Pressure Nozzle Guide Vanes to De-Risk Engine Design Programmes

Volume 5A: Heat Transfer ◽

10.1115/gt2016-57382 ◽

2016 ◽

Author(s):

Benjamin Kirollos ◽

Thomas Povey

Keyword(s):

Thermal Performance ◽

Cooling System ◽

Experimental Tests ◽

University Of Oxford ◽

Engine Design ◽

Infra Red ◽

Nozzle Guide ◽

Processing Techniques ◽

The University ◽

Nozzle Guide Vanes

The continuing maturation of metal laser-sintering technology (DMLS) presents the opportunity to de-risk the engine design process by experimentally down-selecting HPNGV cooling designs using laboratory tests of laser-sintered — instead of cast — parts to assess thermal performance. Such tests could be seen as supplementary to thermal-paint-test engines, which are used during certification to validate cooling system designs. In this paper, we compare conventionally cast and laser-sintered titanium alloy parts in back-to-back experimental tests at engine-representative conditions over a range of coolant mass flow rates. Tests were performed in the University of Oxford Annular Sector Heat Transfer Facility. The thermal performance of the cast and laser-sintered parts — measured using new infra-red processing techniques — is shown to be very similar, demonstrating the utility of laser-sintered parts for preliminary engine thermal assessments. We conclude that the methods reported in this paper are sufficiently mature to make assessments which could influence engine development programmes.

Download Full-text

Post-Processing Techniques to Enhance the Quality of Metallic Parts Produced by Additive Manufacturing

Metals ◽

10.3390/met12010077 ◽

2022 ◽

Vol 12 (1) ◽

pp. 77

Author(s):

Muhammad Arif Mahmood ◽

Diana Chioibasu ◽

Asif Ur Rehman ◽

Sabin Mihai ◽

Andrei C. Popescu

Keyword(s):

Mechanical Properties ◽

Corrosion Resistance ◽

Laser Shock Peening ◽

Laser Shock ◽

Post Processing ◽

Laser Polishing ◽

Shock Peening ◽

Processing Techniques ◽

Am Processes ◽

Conventional Machining

Additive manufacturing (AM) processes can produce three-dimensional (3D) near-net-shape parts based on computer-aided design (CAD) models. Compared to traditional manufacturing processes, AM processes can generate parts with intricate geometries, operational flexibility and reduced manufacturing time, thus saving time and money. On the other hand, AM processes face complex issues, including poor surface finish, unwanted microstructure phases, defects, wear tracks, reduced corrosion resistance and reduced fatigue life. These problems prevent AM parts from real-time operational applications. Post-processing techniques, including laser shock peening, laser polishing, conventional machining methods and thermal processes, are usually applied to resolve these issues. These processes have proved their capability to enhance the surface characteristics and physical and mechanical properties. In this study, various post-processing techniques and their implementations have been compiled. The effect of post-processing techniques on additively manufactured parts has been discussed. It was found that laser shock peening (LSP) can cause severe strain rate generation, especially in thinner components. LSP can control the surface regularities and local grain refinement, thus elevating the hardness value. Laser polishing (LP) can reduce surface roughness up to 95% and increase hardness, collectively, compared to the as-built parts. Conventional machining processes enhance surface quality; however, their influence on hardness has not been proved yet. Thermal post-processing techniques are applied to eliminate porosity up to 99.99%, increase corrosion resistance, and finally, the mechanical properties’ elevation. For future perspectives, to prescribe a particular post-processing technique for specific defects, standardization is necessary. This study provides a detailed overview of the post-processing techniques applied to enhance the mechanical and physical properties of AM-ed parts. A particular method can be chosen based on one’s requirements.

Download Full-text

Post-processing Techniques for On-Line Adaptive Video Summarization Based on Relevance Curves

Semantic Multimedia - Lecture Notes in Computer Science ◽

10.1007/978-3-540-77051-0_17 ◽

2007 ◽

pp. 144-157 ◽

Cited By ~ 2

Author(s):

Víctor Valdés ◽

José M. Martínez

Keyword(s):

Video Summarization ◽

Post Processing ◽

Adaptive Video ◽

On Line ◽

Processing Techniques

Download Full-text

Hydrogen Generation Facilitates Sintering Atmospheres

10.31399/asm.cp.ht2021p0088 ◽

2021 ◽

Author(s):

David Wolff

Keyword(s):

Heat Conduction ◽

Hydrogen Storage ◽

Thermal Processing ◽

Hydrogen Generation ◽

Energy Content ◽

High Energy ◽

Pure Hydrogen ◽

Post Processing ◽

Hydrogen Supply ◽

Processing Techniques

Abstract For annealing, brazing or sintering, furnace atmospheres help ensure that metals thermal processors obtain the results they need. Hydrogen-containing atmospheres are used to protect surfaces from oxidation, and to ensure satisfactory thermal processing results. Hydrogen-containing atmospheres make thermal processing more forgiving because the hydrogen improves heat conduction and actively cleans heated surfaces – reducing oxides and destroying surface impurities. For powder based fabrication such as P/M, MIM or binder-jet metal AM, the use of a hydrogen-containing thermal processing atmosphere ensures the highest possible density of the sintered parts without necessitating the use of post-processing techniques. Users of pure hydrogen or hydrogen-containing gas blend atmospheres often struggle with hydrogen supply options. Hydrogen storage may create compliance problems due to its flammability and high energy content. Hydrogen generation enables hydrogen use without hydrogen storage issues. Deployment of hydrogen generation can ease the addition of thermal processing atmospheres to new and existing processing facilities.

Download Full-text