Materials for intraocular lenses (IOLs): Review of developments to achieve biocompatibility

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
D. Tripti ◽  
R.S. Haldar ◽  
S. Geetha ◽  
U.K. Niyogi ◽  
R.K. Khandal
Keyword(s):  
Development Process ◽  
State Of The Art ◽  
Intraocular Lenses ◽  
Biomedical Devices ◽  
New Materials ◽  
Recent Developments ◽  
Material Sciences ◽  
And Performance ◽  
Materials Used ◽  
The Cost

AbstractIt is true that the developments in material sciences along with the improvements in various aspects of technology involved in transforming materials into products, over the years, have been responsible for making many of the impossible-looking devices possible. It is also a fact that the demand for a new, improved and better material has never ended; in fact it has been increasing to a greater degree and with bigger dimensions than ever before, especially in recent times. As a matter of fact, for certain advanced applications, the need for efforts to have new materials can never be over emphasized; for example, in the area of biomedical devices such as intraocular lens (IOL). The advances in the field of bio-medical applications require the materials of high quality meeting stringent norms of performance. For implants such as the ones like IOL used for correction of vision of the eyes, besides the quality and performance of materials, biocompatibility is an issue of major concern. The material scientists have been working on the development of materials for IOLs targeting the needs arising out of the developing countries. The challenges include not only to bring down the cost of the materials used for IOLs but also to increase the biocompatibility of IOLs. For making the development process easy and bringing the state-of-the- art of knowledge to those looking for new materials, it is thought necessary to review various facets of IOLs in the present paper. Not only the aspects related to the recent developments in biomedical devices of eye care but also related to the properties of available materials vis a vis the deficiencies in properties of existing materials have been covered in this review. The aim has been to bring out the gap areas at various levels of process of product chain starting from the monomer to polymer, blank to IOL, insertion of IOL into eyes to life cycle of IOLs, mainly to provide certain possible and feasible leads to meet the challenges of making new and more biocompatible materials.

scholarly journals Cryogenically-cooled, HEMT amplifiers and receivers in 1-50 GHz range: state-of-the-art

1991 ◽  
Vol 131 ◽  
pp. 60-64
Author(s):  
Marian W. Pospieszalski
Keyword(s):  
Radio Astronomy ◽  
Electron Mobility ◽  
State Of The Art ◽  
High Electron Mobility Transistor ◽  
High Electron ◽  
High Electron Mobility ◽  
Recent Developments ◽  
And Performance ◽  
Design Construction

AbstractA review of the recent developments in the design, construction and performance of cryogenicallycoolable, high-electron-mobility transistor (HEMT, MODFET) amplifiers and their application in compact cryogenic receivers for radio astronomy applications is presented.

scholarly journals State of the Art in Alcohol Sensing with 2D Materials

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Ramin Boroujerdi ◽  
Amor Abdelkader ◽  
Richard Paul
Keyword(s):  
State Of The Art ◽  
2D Materials ◽  
Chemical Species ◽  
Weight Ratio ◽  
Layered Compounds ◽  
Single Atom ◽  
Future Research ◽  
Essential Factor ◽  
New Materials ◽  
Recent Developments

AbstractSince the discovery of graphene, the star among new materials, there has been a surge of attention focused on the monatomic and monomolecular sheets which can be obtained by exfoliation of layered compounds. Such materials are known as two-dimensional (2D) materials and offer enormous versatility and potential. The ultimate single atom, or molecule, thickness of the 2D materials sheets provides the highest surface to weight ratio of all the nanomaterials, which opens the door to the design of more sensitive and reliable chemical sensors. The variety of properties and the possibility of tuning the chemical and surface properties of the 2D materials increase their potential as selective sensors, targeting chemical species that were previously difficult to detect. The planar structure and the mechanical flexibility of the sheets allow new sensor designs and put 2D materials at the forefront of all the candidates for wearable applications. When developing sensors for alcohol, the response time is an essential factor for many industrial and forensic applications, particularly when it comes to hand-held devices. Here, we review recent developments in the applications of 2D materials in sensing alcohols along with a study on parameters that affect the sensing capabilities. The review also discusses the strategies used to develop the sensor along with their mechanisms of sensing and provides a critique of the current limitations of 2D materials-based alcohol sensors and an outlook for the future research required to overcome the challenges.

scholarly journals Trends in Biodiesel Production from Animal Fat Waste

2020 ◽  
Vol 10 (10) ◽  
pp. 3644 ◽  
Author(s):  
Fidel Toldrá-Reig ◽  
Leticia Mora ◽  
Fidel Toldrá
Keyword(s):  
Heterogeneous Catalysts ◽  
Raw Materials ◽  
Biodiesel Production ◽  
Industrial Plants ◽  
Animal Fat ◽  
Recent Developments ◽  
Combustion Emission ◽  
Materials Used ◽  
The Cost ◽  
Alkaline Catalysis

The agro-food industry generates large amounts of waste that contribute to environmental contamination. Animal fat waste constitutes some of the most relevant waste and the treatment of such waste is quite costly because environmental regulations are quite strict. Part of such costs might be reduced through the generation of bioenergy. Biodiesel constitutes a valid renewable source of energy because it is biodegradable, non-toxic and has a good combustion emission profile and can be blended up to 20% with fossil diesel for its use in many countries. Furthermore, up to 70% of the total cost of biodiesel majorly depends on the cost of the raw materials used, which can be reduced using animal fat waste because they are cheaper than vegetable oil waste. In fact, 6% of total feedstock corresponded to animal fat in 2019. Transesterification with alkaline catalysis is still preferred at industrial plants producing biodiesel. Recent developments in heterogeneous catalysts that can be easily recovered, regenerated and reused, as well as immobilized lipases with increased stability and resistance to alcohol denaturation, are promising for future industrial use. This manuscript reviews the available processes and recent advances for biodiesel generation from animal fat waste.

Precise Manipulations with Asymmetric Nano-Objects Viscoelastically Bound to a Surface

2016 ◽  
Vol 39 ◽  
pp. 256-276 ◽  
Author(s):  
Peter M. Lytvyn ◽  
Alexander A. Efremov ◽  
Oksana Lytvyn ◽  
Igor V. Prokopenko ◽  
Yurii I. Mazur ◽  
...  
Keyword(s):  
State Of The Art ◽  
Cost Effective ◽  
Scanning Probe ◽  
Fundamental Limitations ◽  
Atomic Force ◽  
Direct Formation ◽  
Materials Used ◽  
The Cost ◽  
Organic Linker ◽  
Original Approach

This work provides a review of commonly used approaches for fine manipulations with nanoobjects by means of scanning probe microscopes and describes an original alternative cost-effective nanomanipulation method. High precision manipulations are important for up-to-date technologies of nanoelectronic, molecular, hybrid and nanomechanical devices and sensor systems especially for the state of the art fundamental and applied researches. A new method to form nanoassemblies by using asymmetric nanoparticles fixed on the surface with the viscoelastic linker has been proposed, theoretically substantiated and experimentally realized. An original theoretical model has been proposed to describe the ordering process of the linked nanorods by means of the multipass interaction with an atomic force microscope (AFM) tip.In addition, an adjustment of the tip-surface interaction has been proposed and implemented which is independent of the AFM. This original approach is based on additional ultrasonic excitation of the surface. This also enabled us to control the degree binding of the nanoparticles with the substrate.With these techniques we were able to form sets of chains (more than 5-μm length) consisting of nanometer-sized (10x50 nm) gold nanorods (NRs) linked to the surface of gallium arsenide by an organic linker. It has been shown that the viscoelastic binding of asymmetric nanoparticles to the surface allows us to create linear assemblies of nanoobjects in just a few passes of the AFM probe.The proposed technique significantly increases manufacturability of nanomanipulations. Direct formation of nanostructures can significantly reduce the cost of their formation in comparison with modern conventional technological approaches, which in many cases may even have some fundamental limitations (in resolution, in materials used, etc.).

scholarly journals Evaluation of the Feasibility of Parametric Estimation in Devops Continuous Planning

2021 ◽  
Vol 9 (9) ◽  
pp. 542-546
Author(s):  
Dr. Diwakar Ramanuj Tripathi
Keyword(s):  
Development Process ◽  
State Of The Art ◽  
Value Added ◽  
The State ◽  
Parametric Estimation ◽  
Effort Estimation ◽  
Continuous Testing ◽  
Exploratory Testing ◽  
The Cost ◽  
Parametric Estimate

Abstract: DevOps aims to shorten project schedules, boost productivity, and manage quick development-deployment cycles without compromising business or quality. It necessitates good sprint management. Continuous Testing detects integration issues considerably earlier in the development process. It reduces the cost of defect resolution and frees up the tester's time for exploratory testing and value-added activities. Continuous testing allows for more frequent, shorter, and more efficient releases. It ties people, technology, and processes together. Continuous Planning, particularly effort estimation, is closely linked to Continuous Testing. This paper examines the state of the art in DevOps parametric estimate in continuous planning, as well as the difficulties and best practises. Keywords: Project, Testing, Continuous, Planning

scholarly journals The ELAPS framework: Experimental Linear Algebra Performance Studies

2018 ◽  
Vol 33 (2) ◽  
pp. 353-365
Author(s):  
Elmar Peise ◽  
Paolo Bientinesi
Keyword(s):  
Linear Algebra ◽  
Performance Studies ◽  
Development Process ◽  
Problem Size ◽  
Development Stages ◽  
Development Tools ◽  
Classic Approach ◽  
And Performance ◽  
The Cost ◽  
Application Developers

In scientific computing, optimal use of computing resources comes at the cost of extensive coding, tuning, and benchmarking. While the classic approach of “features first, performance later” is supported by a variety of tools such as Tau, Vampir, and Scalasca, the emerging performance-centric approach, in which both features and performance are primary objectives, is still lacking suitable development tools. For dense linear algebra applications, we fill this gap with the Experimental Linear Algebra Performance Studies (ELAPS) framework, a multi-platform open-source environment for easy, fast, and yet powerful performance experimentation and prototyping. In contrast to many existing tools, ELAPS targets the beginning of the development process, assisting application developers in both algorithmic and optimization decisions. With ELAPS, users construct experiments to investigate how performance and efficiency depend on factors such as caching, algorithmic parameters, problem size, and parallelism. Experiments are designed either through Python scripts or a specialized Graphical User Interface (GUI), and run on a spectrum of architectures, ranging from laptops to accelerators and clusters. The resulting reports provide various metrics and statistics that can be analyzed both numerically and visually. In this article, we introduce ELAPS and illustrate its practical value in guiding critical performance decisions already in early development stages.

High Performance Materials Development in the 21st Century: Trends and Directions

2004 ◽  
Vol 449-452 ◽  
pp. 7-12
Author(s):  
James C. Williams
Keyword(s):  
Material Properties ◽  
Gas Turbines ◽  
High Performance ◽  
Matrix Composites ◽  
New Materials ◽  
Materials Development ◽  
Recent Developments ◽  
New Material ◽  
Time Required ◽  
The Cost

Product performance including the cost of ownership is becoming increasingly dependent on the availability of high quality, high performance, affordable materials of construction. Today, the requirements placed on a new material for a high performance structural application extend well beyond the improvement of one or more material properties. This makes the introduction of a new material a multi-faceted activity. Modern structural materials derive their performance from a combination of composition and processing, the results of which are inextricably intertwined. This statement pertains to both metallic alloys and to fiber reinforced composite materials. In addition, material cost and the reproducibility of material properties are becoming more central as acceptance criteria for incorporating new materials into new products. This paper will use examples of recent developments in materials for aircraft gas turbines to depict the materials introduction process. Some of these developments have been successful and others have not. These examples illustrate the changing picture that represents the successful introduction of a new structural material, even in a high performance, high value product such as a gas turbine. Specific examples will include metal matrix composites, Ni-base alloys and improved reliability Ti alloys. The basis for successful introduction, or lack thereof will be discussed. While the examples are specific to gas turbines, they are generally instructive and depict the growing complexity of the process of developing and introducing new materials into a high value product. An additional issue for all new materials introduction is the time required to achieve product readiness. As the time required for product design decreases, there has been little commensurate reduction in materials development cycle time. This matter also will be discussed and some possible reasons and potential solutions will be described.

scholarly journals Developments in Improving Biodiesel Production from Animal Fats

2020 ◽  
Author(s):  
Fidel Toldrá ◽  
Leticia Mora ◽  
Fidel Toldra Reig
Keyword(s):  
Heterogeneous Catalysts ◽  
Raw Materials ◽  
Oxidation Stability ◽  
Process Intensification ◽  
Biodiesel Production ◽  
Animal Fats ◽  
Costly Treatment ◽  
Recent Developments ◽  
Materials Used ◽  
The Cost

Animal fats, usually found as waste from slaughterhouses, meat processing industry, and cooking facilities, constitute some of the most relevant waste with costly treatment because environmental regulations are quite strict. Part of such costs may be reduced through the generation of biodiesel that constitutes a valid renewable source of energy because it is biodegradable, non-toxic and has a good combustion emission profile. Furthermore, biodiesel can be blended up to 20% with fossil diesel for its use in many countries. Up to 70% of the total cost of biodiesel majorly depends on the cost of the raw materials used, which can be reduced using animal fat waste because they are cheaper than vegetable oil waste. Transesterification with alkaline catalysis is still preferred at industrial plants producing biodiesel. However, recent developments in technologies for process intensification like ultrasound, microwave, and different types of reactors have been successfully applied in transesterification and improved biodiesel production. Better efficiency has been achieved with new heterogeneous catalysts and nanocatalysts that can be easily recovered, regenerated and reused, and immobilized lipases with increased stability and resistance to alcohol denaturation. Also new adsorbents for increased oxidation stability of biodiesel. All these developments are promising for industrial use in near future.

Modeling Amorphous Porous Materials and Confined Fluids

MRS Bulletin ◽  
2009 ◽  
Vol 34 (8) ◽  
pp. 592-601 ◽  
Author(s):  
Lev D. Gelb
Keyword(s):  
Porous Materials ◽  
Gas Adsorption ◽  
Activated Carbons ◽  
Sol Gel ◽  
Confined Fluids ◽  
Recent Developments ◽  
Computationally Intensive ◽  
And Performance ◽  
Materials Used ◽  
Made In

AbstractMany of the porous materials used in laboratory and industrial processes do not have simple regular or crystalline structures. This greatly complicates efforts to characterize them and to understand and optimize their performance for particular applications. This review surveys recent efforts to use simulation and modeling to better understand the structure and performance of several classes of materials, including phase-separated glasses, sol-gel–derived materials, templated silica materials, and activated carbons. Approaches to modeling these materials fall generally into two classes: reconstructions, which generate models based on experimental measurements, and mimetic simulations, which attempt to model the preparation of the materials. While significant progress has been made in many respects, both reconstructive and mimetic transferred currently available are often computationally intensive and not easily transferable between different classes of materials. Finally, since gas adsorption is used widely as a characterization tool for amorphous porous materials and is often the focus of the materials' application, recent developments in simulation and theory appropriate to the study of capillary phenomena in amorphous porous materials are reviewed.

Photo-Triggered Nanomaterials for Cancer Theranostic Applications

Nano LIFE ◽  
2021 ◽  
Vol 11 (02) ◽  
pp. 2130004
Author(s):  
Amreen Khan ◽  
Nishant K. Jain ◽  
Mayuri Gandhi ◽  
Rajendra Prasad ◽  
Rohit Srivastava
Keyword(s):  
Multiple Dose ◽  
Therapeutic Potential ◽  
Treatment Approach ◽  
Treatment Strategies ◽  
Drug Action ◽  
Recent Developments ◽  
Materials Used ◽  
Theranostic Applications ◽  
The Cost ◽  
Very High

Cancer is one of the most prevalent diseases with mortality rate considerably increasing every year. Conventional treatment strategies for cancer like chemotherapy suffer from the drawbacks of multiple-dose requirements and non-specificity of drug action. Moreover, the cost involved in the diagnosis and treatment is very high. Recently, the application of nanotechnology in the field of cancer has witnessed tremendous significance due to the unique size, shape, and surface properties of nanomaterials. With the intention to utilize biocompatible and biodegradable nanomaterials in cancer and reduce the non-specificity, approaches such as targeted nanotherapeutics came into existence. Besides having therapeutic potential, some materials demonstrate their applicability in bioimaging forecasting distinct optical properties. In this review, we have discussed the basics and principles guiding the design of different photo-triggered nanotheranostic materials used in cancer. Additionally, recent developments and advantages offered by the NIR-responsive photodynamic and photothermal agents along with their future scope have been presented. An overview of the toxicity and clinical prospect of photosensitive agents is also summarized. Overall, the field of photo-triggered cancer nanotheranostics has huge potential that can be clinically translated into an affordable and safe treatment approach.

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