scholarly journals The Dimensional Stability and Durability of Acrylic Resins for the Injection of Cementitious Systems

2020 ◽  
Vol 4 (1) ◽  
pp. 75
Author(s):  
C. S. Paglia ◽  
A. Krattiger
Keyword(s):  
Dimensional Stability ◽  
Crack Formation ◽  
General Increase ◽  
Acrylic Resins ◽  
Material Stiffness ◽  
Cent Relative Humidity ◽  
Term Basis ◽  
Cyclic Variations ◽  
Cementitious Systems

The dimensional stability and durability of Acrylamide- and Methacrylate-based acrylic resins have been studied. The dimensional stability was characterized by measuring the volume expansion of samples immersed in water for a period up to 240 days or by exposing the samples to 23oC and 50 per cent, 90 per cent relative humidity and by monitoring the shrinkage. The durability was investigated by exposing the resins to cyclic variations of temperature in air and in water. The resins generally exhibit a significant volume change up to 160 per cent of the initial volume when immersed in water or exposed to a relatively dry atmosphere (23oC and 50 per cent). A general increase in the material stiffness and/or crack formation on the surface of the resin is observed. On a long-term basis, the durability of the resins may significantly vary with occasionally a partial or complete deterioration of the some resins. A general better dimensional stability and durability is observed for the Methacrylate-based resins as compared to the Acrylamide-based resins.

Long-term Cyclic Variations of Prominences, Green and Red Coronae over Solar Cycles

2000 ◽  
Vol 179 ◽  
pp. 201-204
Author(s):  
Vojtech Rušin ◽  
Milan Minarovjech ◽  
Milan Rybanský
Keyword(s):  
Emission Lines ◽  
High Latitudes ◽  
Green Line ◽  
Solar Cycles ◽  
The South ◽  
Coronal Emission ◽  
Local Maxima ◽  
The North ◽  
Cyclic Variations

AbstractLong-term cyclic variations in the distribution of prominences and intensities of green (530.3 nm) and red (637.4 nm) coronal emission lines over solar cycles 18–23 are presented. Polar prominence branches will reach the poles at different epochs in cycle 23: the north branch at the beginning in 2002 and the south branch a year later (2003), respectively. The local maxima of intensities in the green line show both poleward- and equatorward-migrating branches. The poleward branches will reach the poles around cycle maxima like prominences, while the equatorward branches show a duration of 18 years and will end in cycle minima (2007). The red corona shows mostly equatorward branches. The possibility that these branches begin to develop at high latitudes in the preceding cycles cannot be excluded.

Socioeconomic Challenges faced by Basin’s People in India

Think India ◽  
2019 ◽  
Vol 22 (2) ◽  
pp. 296-304
Author(s):  
Biplab Tripathy ◽  
Tanmoy Mondal
Keyword(s):  
River Basin ◽  
High Tide ◽  
North East ◽  
The People ◽  
Term Basis ◽  
Major River ◽  
River Ganga ◽  
Basin Region ◽  
Basin Area

India is a subcontinent, there huge no of people lived in river basin area. In India there more or less 80% of people directly or indirectly depend on River. Ganga, Brahamputra in North and North East and Mahanadi, Govabori, Krishna, Kaveri, Narmoda, Tapti, Mahi in South are the major river basin in India. There each year due to flood and high tide lots of people are suffered in river basin region in India. These problems destroy the socio economic peace and hope of the people in river basin. There peoples are continuously suffered by lots of difficulties in sort or in long term basis. Few basin regions are always in high alert at the time of monsoon seasons. Sometime due to over migration from basin area, it becomes empty and creates an ultimate loss of resources in India and causes a dis-balance situation in this area.

A Review on Recent Trends in Nanomaterials and Nanocomposites for Environmental Applications

2020 ◽  
Vol 16 ◽  
Author(s):  
Kannappan Panchamoorthy Gopinath ◽  
Malolan Rajagopal ◽  
Abhishek Krishnan ◽  
Shweta Kolathur Sreerama
Keyword(s):  
Environmental Pollution ◽  
Environmental Remediation ◽  
Carbon Capture ◽  
Potential Applications ◽  
Important Challenge ◽  
Term Basis ◽  
Short And Long Term ◽  
Recent Trends ◽  
Water And Soil Pollution

Background: Depletion and contamination of environmental resources such as water, air and soil caused by human activities is an increasingly important challenge faced around the world. The consequences of environmental pollution are felt acutely by all living beings, both on a short and long-term basis, thereby making methods of remediation of environmental pollution an urgent requirement. Objectives: The objective of this review is to dissect the complications caused by environmental degradation, highlight advancements in the field of nanotechnology and to scrutinize its applications in environmental remediation. Furthermore, the review aims to concisely explain the merits and drawbacks of nanotechnology compared to existing methods. Conclusion: The current and potential applications of nanomaterials and nanocomposites in the prevention, control and reduction of air, water and soil pollution and the mechanisms involved have been elucidated, as have their various merits and demerits. The applications of nanotechnology in the fields of carbon capture and agriculture have also received attention in this review.

Preventative Child Welfare Services in Victoria

1988 ◽  
Vol 13 (1) ◽  
pp. 10-14
Author(s):  
Brian Mitchell
Keyword(s):  
Child Welfare ◽  
Fundamental Principle ◽  
Child Welfare Services ◽  
Welfare Services ◽  
Term Basis ◽  
Voluntary Agencies

The idea of prevention in child welfare is not new. The prevention of substitute placement of children whether on a temporary or long-term basis has been a fundamental principle of child welfare we have held to for many years in Victoria.However, it is only in the last decade that this principle is actually being carried out in practice by a number of voluntary agencies. For many children placement is still commonly used as a solution it is easier to place a child than to promote change within many multi-deficit families.

scholarly journals Study of the Ultraviolet Effect and Thermal Analysis on Polypropylene Nonwoven Geotextile

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1080
Author(s):  
Clever Aparecido Valentin ◽  
Marcelo Kobelnik ◽  
Yara Barbosa Franco ◽  
Fernando Luiz Lavoie ◽  
Jefferson Lins da Silva ◽  
...  
Keyword(s):  
Uv Light ◽  
Polymeric Materials ◽  
Tensile Tests ◽  
Thermomechanical Analysis ◽  
Material Stiffness ◽  
Before And After ◽  
Electron Microscopy Analysis ◽  
Physical Tests ◽  
Nonwoven Geotextile

The use of polymeric materials such as geosynthetics in infrastructure works has been increasing over the last decades, as they bring down costs and provide long-term benefits. However, the aging of polymers raises the question of its long-term durability and for this reason researchers have been studying a sort of techniques to search for the required renewal time. This paper examined a commercial polypropylene (PP) nonwoven geotextile before and after 500 h and 1000 h exposure to ultraviolet (UV) light by performing laboratory accelerated ultraviolet-aging tests. The state of the polymeric material after UV exposure was studied through a wide set of tests, including mechanical and physical tests and thermoanalytical tests and scanning electron microscopy analysis. The calorimetric evaluations (DSC) showed distinct behaviors in sample melting points, attributed to the UV radiation effect on the aged samples. Furthermore, after exposure, the samples presented low thermal stability in the thermomechanical analysis (TMA), with a continuing decrease in their thicknesses. The tensile tests showed an increase in material stiffness after exposition. This study demonstrates that UV aging has effects on the properties of the polypropylene polymer.

Compliance versus adherence in serious and persistent mental illness

2010 ◽  
Vol 17 (1) ◽  
pp. 77-85 ◽  
Author(s):  
Paula K Vuckovich
Keyword(s):  
Mental Illness ◽  
Mentally Ill ◽  
Psychiatric Nurses ◽  
Ethical Implications ◽  
Persistent Mental Illness ◽  
Term Basis ◽  
Nursing Literature ◽  
Compliance Versus ◽  
The Ideal

Failure to follow prescribed treatment has devastating consequences for those who are seriously and persistently mentally ill. Nurses, therefore, try to get clients to take psychotropic medication on a long-term basis. The goal is either compliance or adherence. Although current nursing literature has abandoned the term compliance because of its implications of coercion, in psychiatric nursing practice with patients suffering from serious long-term mental illness compliance and adherence are in fact different goals. The ideal goal is adherence, which requires the patient to be an active participant in the team. This goal is consistent with nurses’ ethical values, but for such patients this is frequently unrealistic. If the person is severely psychotic, treatment may be involuntary and the goal compliance. Psychiatric nurses participate in involuntary treatment and thus should acknowledge the ethical implications of compliance as a goal and not obscure the issue by calling compliance adherence.

Does microwave disinfection affect the dimensional stability of denture base acrylic resins? A systematic review

Gerodontology ◽  
2021 ◽  
Author(s):  
Rodrigo Moreira Bringel Costa ◽  
Helena Sandrini Venante ◽  
Mariana Domingues Pordeus ◽  
Ana Paula Chappuis‐Chocano ◽  
Karin Hermana Neppelenbroek ◽  
...  
Keyword(s):  
Systematic Review ◽  
Dimensional Stability ◽  
Denture Base ◽  
Acrylic Resins

Computer-assisted long-term measurements of urinary output and other biological data

1990 ◽  
Vol 258 (1) ◽  
pp. R274-R280 ◽  
Author(s):  
H. W. Reinhardt ◽  
U. Palm ◽  
R. Mohnhaupt ◽  
K. Dannenberg ◽  
W. Boemke
Keyword(s):  
Sodium Excretion ◽  
Biological Data ◽  
Computer Assisted ◽  
Indwelling Catheters ◽  
Integrative Physiology ◽  
Short Intervals ◽  
Physiological Variables ◽  
Cyclic Variations ◽  
Computerized System

A computerized system is described, combining automatic collection of urine in short intervals (minutes) over long periods (days) and recordings of body temperature, MABP, and heart rate in chronically instrumented conscious dogs. During the studies the dogs are housed in metabolic cages. Indwelling catheters and electrical wires are connected to a specially designed swivel and directed out of the cage to the next room. Infusions, blood sampling, and monitoring can be performed from this room without disturbance to the dogs. Three examples of recordings are given. In one of these examples the sodium excretion patterns on 5 consecutive days under continuous saline infusion in one dog is evaluated. Urine was collected every 20 min. Sodium excretion showed cyclic variations. Fourier analysis exhibited 18-h periods and 4- to 8-h periods. The described system renders, e.g., coherent time series analysis possible for a variety of simultaneously recorded physiological variables and may thus acquire considerable importance for integrative physiology.

scholarly journals Effects of long-term repeated chemical disinfection treatment on the surface hardness self-polymerizing reline resins

2013 ◽  
Vol 1 (1) ◽  
pp. 55
Author(s):  
Luciana de Rezende Pinto ◽  
Paulo Maurício Batista Silva ◽  
Vinicius Carvalho Porto
Keyword(s):  
Surface Hardness ◽  
Knoop Hardness ◽  
Control Group ◽  
Tukey Test ◽  
Acrylic Resins ◽  
Biofilm Removal ◽  
Chemical Solutions ◽  
1960S And 1970S ◽  
The 1960S

Denture hygiene techniques and procedures were developed in the 1960s and 1970s and most studies indicate the importance of mechanical biofilm removal by denture brushing associated with disinfection with chemical solutions. Studies in the literature show many chemical procedures that may be used for denture biofilm control. When the immersion procedure is used, the disinfectant should be selected with regard to its effectiveness in inactivating microorganisms without any adverse effects on the denture materials. PURPOSE: This study investigated the hardness of three self-polymerizing reline resins after long-term repeated chemical disinfections. MATERIAL AND METHODS: Sixty round specimens (30 x 6mm) were made from each material: Jet, Kooliner and Tokuyama Rebase II Fast, and divided in 6 groups (n=10). The control group was stored in water and the others were disinfected with 1%, 2%, 5.25% sodium hypochlorite, 2% glutaraldehyde, and 4% chlorhexidine gluconate, respectively. The specimens were tested for knoop hardness (KHN) before disinfection and after 30, 90 and 180 disinfection cycles. Data were analyzed by analysis of variance followed by the Tukey test at 5%. RESULTS: The hardness of Jet resin varied from 18.74 ± 0.47 to 13.75 ± 0.95 KHN, Kooliner varied from 14.09 ± 1.63 to 7.52 ± 0.88 KHN, and Tokuyama Rebase II Fast from 12.57 ± 0.94 to 8.28 ± 0.39 KHN. Statistically significant decrease in hardness of the three reline acrylic resins was observed early after the first 30 disinfection cycles. CONCLUSION: The hardness of the tested materials decreased after immersion in water and after long-term repeated chemical disinfections.

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