scholarly journals Estudo bibliográfico dos materiais utilizados no sistema construtivo de casas pré-fabricadas: Seus tipos e vantagens / Bibliographic study of materials used in the constructive system of prefabricated homes: Their types and advantages

2021 ◽  
Vol 7 (11) ◽  
pp. 109184-109205
Author(s):  
Antonio Cesar Castro De Freitas ◽  
Reginaldo Beserra Alves ◽  
Erika Cristina Nogueira Marques
Keyword(s):  
Materials Used ◽  
Bibliographic Study

scholarly journals Nanomaterials in Dentistry: State of the Art and Future Challenges

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1770
Author(s):  
Victoria Bonilla-Represa ◽  
Camilo Abalos-Labruzzi ◽  
Manuela Herrera-Martinez ◽  
M. Olga Guerrero-Pérez
Keyword(s):  
Research Effort ◽  
Present Review ◽  
Restorative Dentistry ◽  
Bibliographic Analysis ◽  
Future Challenges ◽  
Metal Organic ◽  
Properties Of Materials ◽  
Materials Used ◽  
Porous Nanomaterials ◽  
Bibliographic Study

Nanomaterials are commonly considered as those materials in which the shape and molecular composition at a nanometer scale can be controlled. Subsequently, they present extraordinary properties that are being useful for the development of new and improved applications in many fields, including medicine. In dentistry, several research efforts are being conducted, especially during the last decade, for the improvement of the properties of materials used in dentistry. The objective of the present article is to offer the audience a complete and comprehensive review of the main applications that have been developed in dentistry, by the use of these materials, during the last two decades. It was shown how these materials are improving the treatments in mainly all the important areas of dentistry, such as endodontics, periodontics, implants, tissue engineering and restorative dentistry. The scope of the present review is, subsequently, to revise the main applications regarding nano-shaped materials in dentistry, including nanorods, nanofibers, nanotubes, nanospheres/nanoparticles, and zeolites and other orders porous materials. The results of the bibliographic analysis show that the most explored nanomaterials in dentistry are graphene and carbon nanotubes, and their derivatives. A detailed analysis and a comparative study of their applications show that, although they are quite similar, graphene-based materials seem to be more promising for most of the applications of interest in dentistry. The bibliographic study also demonstrated the potential of zeolite-based materials, although the low number of studies on their applications shows that they have not been totally explored, as well as other porous nanomaterials that have found important applications in medicine, such as metal organic frameworks, have not been explored. Subsequently, it is expected that the research effort will concentrate on graphene and zeolite-based materials in the coming years. Thus, the present review paper presents a detailed bibliographic study, with more than 200 references, in order to briefly describe the main achievements that have been described in dentistry using nanomaterials, compare and analyze them in a critical way, with the aim of predicting the future challenges.

scholarly journals The development of oxygenators in extra corporeal circulation

2019 ◽  
pp. 13-22
Author(s):  
Stylianos Mimikos ◽  
Evlabia Stroggili ◽  
Georgios Karapanagiotidis
Keyword(s):  
Extracorporeal Circulation ◽  
Current Knowledge ◽  
Holistic Approach ◽  
Blood Oxygenation ◽  
Circulation Circuit ◽  
Membrane Oxygenators ◽  
Materials Used ◽  
Extra Corporeal Circulation ◽  
Bibliographic Study ◽  
Blood Reservoir

The objective of this paper is to present one of the most important components of the extracorporeal circulation circuit, the oxygenator. In addition, the manufacture materials, the function and superiority of modern oxygenators are presented in order to stress their advantages over the older types. The future of oxygenators and the tendency to develop small intravascular artificial lungs are also discussed. A bibliographic study of the history and first reports of extracorporeal blood oxygenation has been performed in an attempt to describe the function of these initial oxygenators and to analyze the disadvantages which led to the development and to the exclusive of the membrane oxygenators. Since the establishment of the current knowledge that the artificial membrane of the modern oxygenators is the best material to oxygenate blood and remove carbon dioxide during extracorporeal circulation, further research concerning the oxygenator’s membrane was necessary to solve particular problems, such as plasma leak. Technologic advantages in the oxygenator’s membrane made possible the safe use of the oxygenator for 28 days in the extracorporeal membrane oxygenation (ECMO) circuits. The different materials used for the construction of the oxygenators are discussed with details. The incorporation in the oxygenator of additional devices, such as the heat exchanger, the arterial filter and blood reservoir to develop one compact construction is considered to be one more upgrade of the oxygenator’s technology. Accidents and safety precautions of the oxygenators are also discussed especially that of the thrombosis of the device. The necessity for more detailed and accurate monitoring of the oxygenator in real time during cardiac surgery is discussed. The latter holistic approach to the operation of the oxygenator and of the components which incorporate in the device offers specific advantages, while modification of the surface in contact with the blood ameliorates the inflammatory response.

Deformation Replication

1970 ◽  
Vol 28 ◽  
pp. 280-281
Author(s):  
J. Temple Black
Keyword(s):  
Cutting Speed ◽  
Machining Process ◽  
Depth Of Cut ◽  
Rake Face ◽  
Orthogonal Machining ◽  
Aluminum Chips ◽  
Before And After ◽  
Materials Used ◽  
Glass Knife ◽  
Very High

Tool materials used in ultramicrotomy are glass, developed by Latta and Hartmann (1) and diamond, introduced by Fernandez-Moran (2). While diamonds produce more good sections per knife edge than glass, they are expensive; require careful mounting and handling; and are time consuming to clean before and after usage, purchase from vendors (3-6 months waiting time), and regrind. Glass offers an easily accessible, inexpensive material ($0.04 per knife) with very high compressive strength (3) that can be employed in microtomy of metals (4) as well as biological materials. When the orthogonal machining process is being studied, glass offers additional advantages. Sections of metal or plastic can be dried down on the rake face, coated with Au-Pd, and examined directly in the SEM with no additional handling (5). Figure 1 shows aluminum chips microtomed with a 75° glass knife at a cutting speed of 1 mm/sec with a depth of cut of 1000 Å lying on the rake face of the knife.

High Voltage Transmission Microscopy of Surveyor III Camera Shrouds

1971 ◽  
Vol 29 ◽  
pp. 138-139
Author(s):  
W. R. Duff ◽  
L. E. Thomas ◽  
R. M. Fisher ◽  
S. V. Radcliffe
Keyword(s):  
Alloy Sheet ◽  
Transmission Microscopy ◽  
Television Camera ◽  
Window Method ◽  
Transmission Electron ◽  
Microstructural Effects ◽  
Lunar Environment ◽  
Successful Retrieval ◽  
Materials Used ◽  
Abrasive Paper

Successful retrieval of the television camera and other components from the Surveyor III spacecraft by the Apollo 12 astronauts has provided a unique opportunity to study the effects of a known and relatively extensive exposure to the lunar environment. Microstructural effects including those produced by micro-meteorite impact, radiation damage (by both the solar wind and cosmic rays) and solar heating might be expected in the materials used to fabricate the spacecraft. Samples received were in the form of 1 cm2 of painted unpainted aluminum alloy sheet from the top of the camera visor (JPL Code 933) and the sides (935,936) and bottom (934) of the lower camera shroud. They were prepared for transmission electron microscopy by first hand-grinding with abrasive paper to a thickness of 0.006". The edges were lacquered and the sample electropolished in 10% perchloric methanol using the “window” method, to a thickness of ~0.001". Final thinning was accomplished by polishing 3 mm punched disks in an acetic-phosphoric-nitric acid solution.

Structure-property relationships of PE/PP sandwiched films

1987 ◽  
Vol 45 ◽  
pp. 454-455
Author(s):  
J. Petermann ◽  
G. Broza ◽  
U. Rieck ◽  
A. Jaballah ◽  
A. Kawaguchi
Keyword(s):  
Mechanical Tests ◽  
Polymer Materials ◽  
Ionic Crystals ◽  
Structure Property ◽  
Polymer Systems ◽  
Structure Property Relationships ◽  
Oriented Films ◽  
Materials Used ◽  
Polymer Laminates ◽  
Heated Glass

Oriented overgrowth of polymer materials onto ionic crystals is well known and recently it was demonstrated that this epitaxial crystallisation can also occur in polymer/polymer systems, under certain conditions. The morphologies and the resulting physical properties of such systems will be presented, especially the influence of epitaxial interfaces on the adhesion of polymer laminates and the mechanical properties of epitaxially crystallized sandwiched layers.Materials used were polyethylene, PE, Lupolen 6021 DX (HDPE) and 1810 D (LDPE) from BASF AG; polypropylene, PP, (PPN) provided by Höchst AG and polybutene-1, PB-1, Vestolen BT from Chemische Werke Hüls. Thin oriented films were prepared according to the method of Petermann and Gohil, by winding up two different polymer films from two separately heated glass-plates simultaneously with the help of a motor driven cylinder. One double layer was used for TEM investigations, while about 1000 sandwiched layers were taken for mechanical tests.

HYDROXYAPATITE, ALGINATE, AND CHITOSAN FOR BONE SCAFFOLDS: SPECTROSCOPY STUDY

2016 ◽  
Vol 19 (2) ◽  
pp. 93-100
Author(s):  
Lalita El Milla
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Functional Groups ◽  
Bone Growth ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Tissue Engineering Scaffolds ◽  
Hydroxyapatite Powder ◽  
Materials Used

Scaffolds is three dimensional structure that serves as a framework for bone growth. Natural materials are often used in synthesis of bone tissue engineering scaffolds with respect to compliance with the content of the human body. Among the materials used to make scafffold was hydroxyapatite, alginate and chitosan. Hydroxyapatite powder obtained by mixing phosphoric acid and calcium hydroxide, alginate powders extracted from brown algae and chitosan powder acetylated from crab. The purpose of this study was to examine the functional groups of hydroxyapatite, alginate and chitosan. The method used in this study was laboratory experimental using Fourier Transform Infrared (FTIR) spectroscopy for hydroxyapatite, alginate and chitosan powders. The results indicated the presence of functional groups PO43-, O-H and CO32- in hydroxyapatite. In alginate there were O-H, C=O, COOH and C-O-C functional groups, whereas in chitosan there were O-H, N-H, C=O, C-N, and C-O-C. It was concluded that the third material containing functional groups as found in humans that correspond to the scaffolds material in bone tissue engineering.

Brownstock washing: A review of the literature

TAPPI Journal ◽  
2014 ◽  
Vol 13 (1) ◽  
pp. 9-19 ◽  
Author(s):  
RICARDO B. SANTOS ◽  
PETER W. HART
Keyword(s):  
High Efficiency ◽  
Black Liquor ◽  
Material Balance ◽  
Kraft Pulping ◽  
Wash Water ◽  
Pulp Fibers ◽  
Kraft Process ◽  
Cooking Process ◽  
Materials Used ◽  
Entrapped Air

Brownstock washing is a complex, dynamic process in which dirty wash water or weak black liquor (dissolved organic and inorganic material obtained from the pulp cooking process) is separated from pulp fibers. The use of material balance techniques is of great importance to identify potential problems and determine how well the system is operating. The kraft pulping industry was the first known to combine pulp washing with the recovery of materials used and produced in the wood cooking process. The motivation behind materials recovery is economic, and more recently, environmentally driven. The chemicals used in the kraft process are expensive as compared to those used in the sulfite process. For the kraft process to be economically viable, it is imperative that a very high percentage of the cooking chemicals be recovered. To reach such high efficiency, a variety of washing systems and monitoring parameters have been developed. Antifoam additives and processing aids have also played an important role in increasing washing effectiveness. Antifoam materials help attain washing effectiveness by preventing entrapped air from forming in the system, which allows for an easier, unimpeded flow of filtrate through the screens and washers.

Growth and yield of okra (Abelmoschus esculentus (L.) Moench) grown in the marginal upland area of Sta. Rita, Samar as influenced by different planting densities and mulching materials

2017 ◽  
pp. 44-54
Author(s):  
Zenaida Gonzaga ◽  
Warren Obeda ◽  
Ana Linda Gorme ◽  
Jessie Rom ◽  
Oscar Abrantes ◽  
...  
Keyword(s):  
Bare Soil ◽  
Abelmoschus Esculentus ◽  
Growth And Yield ◽  
Planting Density ◽  
Rice Hull ◽  
Plastic Mulch ◽  
Lady’S Finger ◽  
Materials Used ◽  
Set Up ◽  
A Minor

Okra or Lady’s finger, botanically known as Abelmoschus esculentus (L.) Moench, is a tropical and sub-tropical indigenous vegetable crop commonly grown for its fibrous, slimy, and nutritious fruits and consumed by all classes of population. It has also several medicinal and economic values. Despite its many uses and potential value, its importance is under estimated, under-utilized, and considered a minor crop and little attention was paid to its improvement. The study was conducted to evaluate the effects of different planting densities and mulching materials on the growth and yield of okra grown in slightly sloping area in the marginal uplands in Sta. Rita, Samar, Philippines. A split-plot experiment was set up with planting density as main plot and the different mulching materials as the sub-plot which were: unmulched or bare soil, rice straw, rice hull, hagonoy and plastic mulch. Planting density did not significantly affect the growth and yield of okra. Regardless ofthe mulching materials used, mulched plants were taller and yielded higher compared to unmulched plants. Moreover, the use of plastic mulch resulted to the highest total fruit yield. The results indicate the potential of mulching in increasing yield and thus profitability of okra production under marginal upland conditions.

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