scholarly journals Recent Advances in MEMS Metasurfaces and Their Applications on Tunable Lens

Micromachines ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 505 ◽  
Author(s):  
Shaowei He ◽  
Huimin Yang ◽  
Yunhui Jiang ◽  
Wenjun Deng ◽  
Weiming Zhu

The electromagnetic (EM) properties of metasurfaces depend on both structural design and material properties. microelectromechanical systems (MEMS) technology offers an approach for tuning metasurface EM properties by structural reconfiguration. In the past 10 years, vast applications have been demonstrated based on MEMS metasurfaces, which proved to have merits including, large tunability, fast speed, small size, light weight, capability of dense integration, and compatibility of cost-effective fabrication process. Here, recent advances in MEMS metasurface applications are reviewed and categorized based on the tuning mechanisms, operation band and tuning speed. As an example, the pros and cons of MEMS metasurfaces for tunable lens applications are discussed and compared with traditional tunable lens technologies followed by the summary and outlook.

2021 ◽  
Author(s):  
Shiiun Bak Wong ◽  
Nur Dalila Alias ◽  
Mohd Kamal Arif ◽  
Majid Shabazi

Abstract The rise of offshore marginal field development and low-cost CAPEX has given an impetus to O&G operators to challenge the common structural platform design especially for wellhead platform type. Demand to reduce the platform weight has been observed for the past 20 years. Typically, the challenge to meet this demand will be tremendous once the water depth exceed 50m. This paper will elaborate on how using an engineered design approach was implemented to obtain fast track onshore fabrication and offshore installation and meet the operator demand for minimal structural concept.


Author(s):  
Ankita Yadav ◽  
◽  
Mohammad Arif ◽  

This research is conducted in order to deal with the main problem of traffic congestion and road accidents that is basically caused because of the improper parking management. . Hence, it is important that cities have a well-managed parking system. In the past various researches has been done to design a suitable smart paring algorithm. However, each research had their own pros and cons. Our research leads to a smart algorithm that is secure and is convenient enough to develop a system that can be manage the available slots and can notify the users about the available parking slot beforehand to the client. The result analysis clearly shows that the algorithm proposed and designed is more accurate than other algorithms used in the past. The proposed algorithm is designed using ACO, decision tree, and GPS mapping. The idea of working on this research was to provide a solution that is cost effective, helps people on large scale and maintains the laws and order.


MRS Bulletin ◽  
2001 ◽  
Vol 26 (4) ◽  
pp. 291-295 ◽  
Author(s):  
Andrea E. Franke ◽  
Tsu-Jae King ◽  
Roger T. Howe

While microelectromechanical systems (MEMS) technology has made a substantial impact over the past decade at the device or component level, it has yet to realize the “S” in its acronym, as complex microsystems consisting of sensors and actuators integrated with sense, control, and signal-processing electronics are still beyond the current state of the art. There are several incentives to co-fabricate MEMS devices and electronics on a single silicon chip, which apply to applications such as inertial sensors.


TAPPI Journal ◽  
2018 ◽  
Vol 17 (09) ◽  
pp. 519-532 ◽  
Author(s):  
Mark Crisp ◽  
Richard Riehle

Polyaminopolyamide-epichlorohydrin (PAE) resins are the predominant commercial products used to manufacture wet-strengthened paper products for grades requiring wet-strength permanence. Since their development in the late 1950s, the first generation (G1) resins have proven to be one of the most cost-effective technologies available to provide wet strength to paper. Throughout the past three decades, regulatory directives and sustainability initiatives from various organizations have driven the development of cleaner and safer PAE resins and paper products. Early efforts in this area focused on improving worker safety and reducing the impact of PAE resins on the environment. These efforts led to the development of resins containing significantly reduced levels of 1,3-dichloro-2-propanol (1,3-DCP) and 3-monochloropropane-1,2-diol (3-MCPD), potentially carcinogenic byproducts formed during the manufacturing process of PAE resins. As the levels of these byproducts decreased, the environmental, health, and safety (EH&S) profile of PAE resins and paper products improved. Recent initiatives from major retailers are focusing on product ingredient transparency and quality, thus encouraging the development of safer product formulations while maintaining performance. PAE resin research over the past 20 years has been directed toward regulatory requirements to improve consumer safety and minimize exposure to potentially carcinogenic materials found in various paper products. One of the best known regulatory requirements is the recommendations of the German Federal Institute for Risk Assessment (BfR), which defines the levels of 1,3-DCP and 3-MCPD that can be extracted by water from various food contact grades of paper. These criteria led to the development of third generation (G3) products that contain very low levels of 1,3-DCP (typically <10 parts per million in the as-received/delivered resin). This paper outlines the PAE resin chemical contributors to adsorbable organic halogens and 3-MCPD in paper and provides recommendations for the use of each PAE resin product generation (G1, G1.5, G2, G2.5, and G3).


1996 ◽  
Vol 24 (2) ◽  
pp. 119-131
Author(s):  
F. Lux ◽  
H. Stumpf

Abstract Current demands by the consumer, the automobile industry, and the environment have determined the basis of this investigation. In the past, the requirements—ever faster, ever sportier—were accepted as decisive parameters for the development of our study. In the future, rational and safety-related tire characteristics as well as environmental consciousness will increase, whereas purely performance-related parameters will diminish in their importance. Through our light-weight tire project, we have paved the way for future tire generations. The first priority is the minimal use of material resources; this means a reduction of materials and energy in tire production by using advanced design and production methods without sacrificing performance standards. This benefits the consumer—the final judge of all of our activities—by considerably reducing the rolling resistance, leading to lower fuel consumption. Further design targets include the improvement of rolling behavior and increased comfort by reducing tire weight, and therefore a reduction in unsprung masses on the vehicle.


2019 ◽  
Vol 26 (28) ◽  
pp. 5340-5362 ◽  
Author(s):  
Xin Chen ◽  
Giuseppe Gumina ◽  
Kristopher G. Virga

:As a long-term degenerative disorder of the central nervous system that mostly affects older people, Parkinson’s disease is a growing health threat to our ever-aging population. Despite remarkable advances in our understanding of this disease, all therapeutics currently available only act to improve symptoms but cannot stop the disease progression. Therefore, it is essential that more effective drug discovery methods and approaches are developed, validated, and used for the discovery of disease-modifying treatments for Parkinson’s disease. Drug repurposing, also known as drug repositioning, or the process of finding new uses for existing or abandoned pharmaceuticals, has been recognized as a cost-effective and timeefficient way to develop new drugs, being equally promising as de novo drug discovery in the field of neurodegeneration and, more specifically for Parkinson’s disease. The availability of several established libraries of clinical drugs and fast evolvement in disease biology, genomics and bioinformatics has stimulated the momentums of both in silico and activity-based drug repurposing. With the successful clinical introduction of several repurposed drugs for Parkinson’s disease, drug repurposing has now become a robust alternative approach to the discovery and development of novel drugs for this disease. In this review, recent advances in drug repurposing for Parkinson’s disease will be discussed.


2020 ◽  
Vol 16 (4) ◽  
pp. 454-486 ◽  
Author(s):  
Smita Verma ◽  
Vishnuvardh Ravichandiran ◽  
Nihar Ranjan ◽  
Swaran J.S. Flora

Nitrogen-containing heterocycles are one of the most common structural motifs in approximately 80% of the marketed drugs. Of these, benzimidazoles analogues are known to elicit a wide spectrum of pharmaceutical activities such as anticancer, antibacterial, antiparasitic, antiviral, antifungal as well as chemosensor effect. Based on the benzimidazole core fused heterocyclic compounds, crescent-shaped bisbenzimidazoles were developed which provided an early breakthrough in the sequence-specific DNA recognition. Over the years, a number of functional variations in the bisbenzimidazole core have led to the emergence of their unique properties and established them as versatile ligands against several classes of pathogens. The present review provides an overview of diverse pharmacological activities of the bisbenzimidazole analogues in the past decade with a brief account of its development through the years.


Author(s):  
Dale Purves

Brains as Engines of Association seeks an operating principle of the human brain and is divided into four parts. The first part (“What Nervous Systems Do for Animals”) is intended to set the stage for understanding the emergence of neural systems as promoting what all organisms must accomplish: survival and reproduction. The second part (“Neural Systems as Engines of Association”) lays out the general argument that biological sensing systems face a daunting problem: they cannot measure the parameters of the world in the way physical instruments can. As a result, nervous systems must make and update associations (synaptic connections) on the basis of empirical success or failure over both evolutionary and individual time. The third part (“Evidence that Neural Systems Operate Empirically”) reviews evidence accumulated over the past 20 years that supports this interpretation in vision and audition, the sensory systems that have been most studied from this or any other perspective. Finally, the fourth part (“Alternative Concepts of Neural Function”) considers the pros and cons of other interpretations of how brains operate. The overarching theme is that the nervous systems of humans and every other animal operate on the basis associations between stimuli and behavior made by trial and error over species and lifetime experience.


2021 ◽  
Author(s):  
Roger A. Sheldon ◽  
Alessandra Basso ◽  
Dean Brady

This tutorial review focuses on recent advances in technologies for enzyme immobilisation, enabling their cost-effective use in the bio-based economy and continuous processing in general.


Author(s):  
Liping Yao ◽  
Danlei Zhu ◽  
Hailiang Liao ◽  
Sheik Haseena ◽  
Mahesh kumar Ravva ◽  
...  

Due to their advantages of low-cost, light-weight, and mechanical flexibility, much attention has been focused on pi-conjugated organic semiconductors. In the past decade, although many materials with high performance has...


Sign in / Sign up

Export Citation Format

Share Document