Mesh Simplification - A New Approach

2011 ◽  
pp. 65-82
Author(s):  
Siti Khadijah Ali ◽  
Rahmita Wirza O. K. Rahmat ◽  
Fatimah Khalid ◽  
Seng Beng Ng

Pemudahan permukaan telah menjadi topik kajian yang menarik dalam beberapa dekad ini. Sesetengah penyelidik memperkenalkan kaedah yang baharu manakala penyelidik lain melakukan pengubahsuaian ataupun penambahbaikan terhadap kaedah yang sedia ada. Walau bagaimanapun, model yang telah dipermudahkan mempunyai kecenderungan untuk kehilangan sebahagian daripada bentuk asalnya. Dalam pada itu, untuk mengatasi segala masalah ini, satu algoritma baru diperkenalkan, di mana formula nisbah digunakan untuk mengenal pasti calon elemen yang layak untuk dibuang. Elemen yang digunakan dalam algoritma baru ini adalah segitiga. Keputusan kajian menunjukkan bahawa algoritma yang dicadangkan dapat mengekalkan bentuk permukaan model asal. Kata kunci: Permudahan permukaan; persamaan rasional; berjenis; segitiga kontraksi; penipisan permukaan Mesh simplification has become an interesting research area over the past few decades. Some researchers have introduced various new methods while others have made some modifications or improvements to the existing method. However, the modified model tended to lose some of its original shape. Hence, to solve these arising problems, a new decimation algorithm is introduced, in which rational equation is used to select elements as candidates to be removed. The proposed algorithm also uses triangular mesh as the element. The results show that our proposed algorithm can preserve the shape of the mesh. Key words: Mesh simplification; rational equation; manifold; triangle contraction; mesh decimation

Author(s):  
Douglass F. Taber ◽  
Tristan Lambert

Organic synthesis is a vibrant and rapidly evolving field; chemists can now cyclize alkenes directly onto enones. Like the first five books in this series, Organic Synthesis: State of the Art 2013-2015 will lead readers quickly to the most important recent developments in a research area. This series offers chemists a way to stay abreast of what's new and exciting in organic synthesis. The cumulative reaction/transformation index of 2013-2015 outlines all significant new organic transformations over the past twelve years. Future volumes will continue to come out every two years. The 2013-2015 volume features the best new methods in subspecialties such as C-O, C-N and C-C ring construction, catalytic asymmetric synthesis, selective C-H functionalization, and enantioselective epoxidation. This text consolidates two years of Douglass Taber's popular weekly online column, "Organic Chemistry Highlights" as featured on the organic-chemistry.org website and also features cumulative indices of all six volumes in this series, going back twelve years.


Author(s):  
W. A. Chiou ◽  
N. Kohyama ◽  
B. Little ◽  
P. Wagner ◽  
M. Meshii

The corrosion of copper and copper alloys in a marine environment is of great concern because of their widespread use in heat exchangers and steam condensers in which natural seawater is the coolant. It has become increasingly evident that microorganisms play an important role in the corrosion of a number of metals and alloys under a variety of environments. For the past 15 years the use of SEM has proven to be useful in studying biofilms and spatial relationships between bacteria and localized corrosion of metals. Little information, however, has been obtained using TEM capitalizing on its higher spacial resolution and the transmission observation of interfaces. The research presented herein is the first step of this new approach in studying the corrosion with biological influence in pure copper.Commercially produced copper (Cu, 99%) foils of approximately 120 μm thick exposed to a copper-tolerant marine bacterium, Oceanospirillum, and an abiotic culture medium were subsampled (1 cm × 1 cm) for this study along with unexposed control samples.


2009 ◽  
Vol 5 (1) ◽  
pp. 32
Author(s):  
Melanie Maytin ◽  
Laurence M Epstein ◽  
◽  

Prior to the introduction of successful intravascular countertraction techniques, options for lead extraction were limited and dedicated tools were non-existent. The significant morbidity and mortality associated with these early extraction techniques limited their application to life-threatening situations such as infection and sepsis. The past 30 years have witnessed significant advances in lead extraction technology, resulting in safer and more efficacious techniques and tools. This evolution occurred out of necessity, similar to the pressure of natural selection weeding out the ineffective and highly morbid techniques while fostering the development of safe, successful and more simple methods. Future developments in lead extraction are likely to focus on new tools that will allow us to provide comprehensive device management and the design of new leads conceived to facilitate future extraction. With the development of these new methods and novel tools, the technique of lead extraction will continue to require operators that are well versed in several methods of extraction. Garnering new skills while remembering the lessons of the past will enable extraction technologies to advance without repeating previous mistakes.


Author(s):  
Sagar T. Malsane ◽  
Smita S. Aher ◽  
R. B. Saudagar

Oral route is presently the gold standard in the pharmaceutical industry where it is regarded as the safest, most economical and most convenient method of drug delivery resulting in highest patient compliance. Over the past three decades, orally disintegrating tablets (FDTs) have gained considerable attention due to patient compliance. Usually, elderly people experience difficulty in swallowing the conventional dosage forms like tablets, capsules, solutions and suspensions because of tremors of extremities and dysphagia. In some cases such as motion sickness, sudden episodes of allergic attack or coughing, and an unavailability of water, swallowing conventional tablets may be difficult. One such problem can be solved in the novel drug delivery system by formulating “Fast dissolving tablets” (FDTs) which disintegrates or dissolves rapidly without water within few seconds in the mouth due to the action of superdisintegrant or maximizing pore structure in the formulation. The review describes the various formulation aspects, superdisintegrants employed and technologies developed for FDTs, along with various excipients, evaluation tests, marketed formulation and drugs used in this research area.


2018 ◽  
Author(s):  
Gaolei Zhan ◽  
Younes Makoudi ◽  
Judicael Jeannoutot ◽  
Simon Lamare ◽  
Michel Féron ◽  
...  

Over the past decade, on-surface fabrication of organic nanostructures has been widely investigated for the development of molecular electronic devices, nanomachines, and new materials. Here, we introduce a new strategy to obtain alkyl oligomers in a controlled manner using on-surface radical oligomerisations that are triggered by the electrons/holes between the sample surface and the tip of a scanning tunnelling microscope. The resulting radical-mediated mechanism is substantiated by a detailed theoretical study. This electron transfer event only occurs when <i>V</i><sub>s</sub> < -3 V or <i>V</i><sub>s</sub> > + 3 V and allows access to reactive radical species under exceptionally mild conditions. This transfer can effectively ‘switch on’ a sequence leading to formation of oligomers of defined size distribution due to the on-surface confinement of reactive species. Our approach enables new ways to initiate and control radical oligomerisations with tunnelling electrons, leading to molecularly precise nanofabrication.


STUDIUM ◽  
2018 ◽  
pp. 189-208
Author(s):  
Patricia Aguirre

El siguiente artículo ejemplifica con tres elementos del servicio de mesa (la olla, la fuente y el plato) las formas características en que se despliega la comensalidad en diferentes sectores de ingresos, sexos y edades, en Argentina. Diferencia las prácticas, los actores y los sentidos ligados al repartir y al compartir, en cada sector, señalando que el reparto es una obligación ligada a las jerarquías mientras que compartir es una elección libre y afectuosa basada en la amistad y la confianza de la cual se espera reciprocidad. Se señala que tal como muestran el asado y el mate en el pasado, se puede compartir tanto con el alimento más prestigioso (la carne asada) como sin comida: en la ronda del mate. Palabras clave: Comensalidad, ingresos, compartir, repartir, representaciones   Abstract Through the pot, the platter and the dish —three objects used at meal times— this article exemplifies typical ways of commensality in Argentina, among groups whose income, sex, and age differ. The article points to the differences between practices, actors, and senses involved in distributing and sharing in each sector. It shows that distribution is an obligation related to hierarchy, whereas sharing is a free, loving decision based on trust and friendship and that reciprocity is expected. As shown by asado and mate in the past, it is possible to share regardless of what is being shared. In the example, asado stands for prestigious meat done on a charcoal grill, whereas the mate circle is not about food. Key words: commensality, income, share, distribute, representations


2020 ◽  
Author(s):  
Jelena O'Reilly ◽  
Eva Jakupčević

Although the second language (L2) acquisition of morphology by late L2 learners has been a popular research area over the past decades, comparatively little is known about the acquisition and development of morphology in children who learn English as a foreign language (EFL). Therefore, the current study presents the findings from a longitudinal oral production study with 9/10-year-old L1 Croatian EFL students who were followed up at the age of 11/12. Our results are largely in line with the limited research so far in this area: young EFL learners have few issues using the be copula and, eventually, the irregular past simple forms, but had considerable problems with accurately supplying the 3rd person singular -s at both data collection points. We also observed a be + base form structure, especially at the earlier stage, which appears to be an emergent past simple construction.


2018 ◽  
Vol 25 (5) ◽  
pp. 636-658 ◽  
Author(s):  
Jan Pokorny ◽  
Lucie Borkova ◽  
Milan Urban

Triterpenoids are natural compounds with a large variety of biological activities such as anticancer, antiviral, antibacterial, antifungal, antiparazitic, antiinflammatory and others. Despite their low toxicity and simple availability from the natural resources, their clinical use is still severely limited by their higher IC50 and worse pharmacological properties than in the currently used therapeutics. This fact encouraged a number of researchers to develop new terpenic derivatives more suitable for the potential clinical use. This review summarizes a new approach to improve both, the activity and ADME-Tox properties by connecting active terpenes to another modifying molecules using click reactions. Within the past few years, this synthetic approach was well explored yielding a lot of great improvements of the parent compounds along with some less successful attempts. A large quantity of the new compounds presented here are superior in both activity and ADME-Tox properties to their parents. This review should serve the researchers who need to promote their hit triterpenic structures towards their clinical use and it is intended as a guide for the chemical synthesis of better drug candidates.


Micromachines ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 118
Author(s):  
Jean-Laurent Pouchairet ◽  
Carole Rossi

For the past two decades, many research groups have investigated new methods for reducing the size and cost of safe and arm-fire systems, while also improving their safety and reliability, through batch processing. Simultaneously, micro- and nanotechnology advancements regarding nanothermite materials have enabled the production of a key technological building block: pyrotechnical microsystems (pyroMEMS). This building block simply consists of microscale electric initiators with a thin thermite layer as the ignition charge. This microscale to millimeter-scale addressable pyroMEMS enables the integration of intelligence into centimeter-scale pyrotechnical systems. To illustrate this technological evolution, we hereby present the development of a smart infrared (IR) electronically controllable flare consisting of three distinct components: (1) a controllable pyrotechnical ejection block comprising three independently addressable small-scale propellers, all integrated into a one-piece molded and interconnected device, (2) a terminal function block comprising a structured IR pyrotechnical loaf coupled with a microinitiation stage integrating low-energy addressable pyroMEMS, and (3) a connected, autonomous, STANAG 4187 compliant, electronic sensor arming and firing block.


2021 ◽  
pp. 105971232098304
Author(s):  
R Alexander Bentley ◽  
Joshua Borycz ◽  
Simon Carrignon ◽  
Damian J Ruck ◽  
Michael J O’Brien

The explosion of online knowledge has made knowledge, paradoxically, difficult to find. A web or journal search might retrieve thousands of articles, ranked in a manner that is biased by, for example, popularity or eigenvalue centrality rather than by informed relevance to the complex query. With hundreds of thousands of articles published each year, the dense, tangled thicket of knowledge grows even more entwined. Although natural language processing and new methods of generating knowledge graphs can extract increasingly high-level interpretations from research articles, the results are inevitably biased toward recent, popular, and/or prestigious sources. This is a result of the inherent nature of human social-learning processes. To preserve and even rediscover lost scientific ideas, we employ the theory that scientific progress is punctuated by means of inspired, revolutionary ideas at the origin of new paradigms. Using a brief case example, we suggest how phylogenetic inference might be used to rediscover potentially useful lost discoveries, as a way in which machines could help drive revolutionary science.


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