scholarly journals Analysis of Changes in the Tensile Bond Strenght of Soft Relining Material with Acrylic Denture Material

Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 6868
Author(s):  
Magdalena Wyszyńska ◽  
Ewa Białożyt-Bujak ◽  
Grzegorz Chladek ◽  
Aleksandra Czelakowska ◽  
Rafał Rój ◽  
...  
Keyword(s):  
Failure Time ◽  
Water Environment ◽  
Patient Comfort ◽  
Functional Feature ◽  
Excessive Pressure ◽  
Average Value ◽  
Acrylic Plate ◽  
Elastomeric Materials ◽  
Materials Used ◽  
Type Of Failure

Abrasions and pressure ulcers on the oral mucosa are most often caused by excessive pressure or incorrect fitting of the denture. The use of soft relining materials can eliminate pain sensations and improve patient comfort. The main functional feature of soft elastomeric materials is the ability to discharge loads from the tissues of the mucosa. (1) Background: The aim of the work was a comparative laboratory study of ten materials used for the soft lining of acrylic dentures. (2) Methods: There were materials based on acrylates (Vertex Soft, Villacryl Soft, Flexacryl Soft) and silicones (Sofreliner Tough Medium, Sofreliner Tough Medium, Ufi Gel SC, GC Reline Soft, Elite Soft Relining, Molloplast). Laboratory tests include the analysis of the tensile bond strength between the relining material and the acrylic plate of the prosthesis. The tests were conducted taking into account 90-day term aging in the distilled water environment based on the methodology presented in the European Standard ISO 10139-2. (3) Results: After three months of observation, the highest strength of the joint was characterized by Flexacryl Soft acrylic, for which the average value was 2.5 MPa. The lowest average value of 0.89 MPa was recorded for the GC Reline Soft silicone material. Over time, an increase in the value of the strength of the combination of acrylic materials and a decrease in these values in the case of silicone materials was observed. (4) Conclusion: Each of the tested silicone materials showed all three types of damage, from adhesive to mixed to cohesive. All acrylic-based materials showed an adhesive type of failure. Time did not affect the type of destruction.

scholarly journals Analysis of the Hardness of Soft Relining Materials for Removable Dentures

2021 ◽  
Vol 18 (18) ◽  
pp. 9491
Author(s):  
Ewa Białożyt-Bujak ◽  
Magdalena Wyszyńska ◽  
Grzegorz Chladek ◽  
Aleksandra Czelakowska ◽  
Andrzej Gala ◽  
...  
Keyword(s):  
Laboratory Tests ◽  
Water Environment ◽  
Complete Dentures ◽  
European Standard ◽  
Functional Feature ◽  
Equal Distribution ◽  
Denture Plate ◽  
Chewing Ability ◽  
Materials Used ◽  
Over Time

The main functional feature of elastomeric soft linings materials is the ability to discharge loads in the tissues of the mucosa. As a result, there are fewer injuries to the mucosa and chewing ability increases. In addition, these prostheses are more comfortable in the patient’s opinion. To obtain the equal distribution of forces on the muco-bone basis and to reduce the traumatizing effect of the denture plate for patients using full dentures, soft lining materials can be used. Aim of the study: the aim of the work was a comparative laboratory study of ten materials used for soft lining of acrylic complete dentures. Methodology: Materials based on acrylates (Vertex Soft, Villacryl Soft, Flexacryl Soft) and on silicones (Sofreliner Tough Medium, Sofreliner Tough Medium, Ufi Gel SC, GC Reline Soft, Elite Soft Relining, Molloplast) were compared. Laboratory tests include tests of changes in Shore’a A hardness of soft lining material. The tests were conducted taking into account 90 day term aging in the distilled water environment based on the methodology presented in the European Standard ISO 10139-2. Results: For most silicone materials, only small changes in hardness were found in the range of 0.7 (Ufi Gel SC) to 3.3 (Sofreliner Tough Medium) on the Shore A scale. The exception was GC Reline Soft, for which a marked increase in hardness was noted. All materials based on acrylates were characterized by successive increase in hardness over time. However, in the case of the Vertex Soft material, the increase in hardness was relatively small (5.5 ShA).

PENGEMBANGAN BAHAN AJAR TEKS DRAMA BERDASARKAN PENGALAMAN PENGARANG

2019 ◽  
Vol 8 (2) ◽  
Author(s):  
Didin Khaerudin ◽  
Suherli Kusmana ◽  
Iyay Robia Khaerudin
Keyword(s):  
Personal Experience ◽  
Teaching Materials ◽  
Learning Skills ◽  
Student Activities ◽  
Development Method ◽  
Average Value ◽  
Surrounding Environment ◽  
Basic Competencies ◽  
Materials Used ◽  
Minimum Criteria

Research conducted to develop drama text teaching materials based on the experience of the author of the drama script aims to make it easier for students to understand drama text material. In addition, based on the author's experience students are expected to emulate the author's creative process in writing a paper. The research method used in this research is the research and development method. Based on the results of the interview it can be concluded that the ability to write drama is determined based on mastery of the elements of drama and the ability to develop stories based on the author's experience. The process of writing drama is done in several steps: (1) searching for ideas based on personal experience, other people, or the surrounding environment; (2) processing ideas to find plots (characters), characters or characters that vary with their inner conflicts, settings and dialogues, interesting conflicts, and messages to be conveyed; (3) starts the process of writing drama with stages and elements of drama; (4) revision of drama products. Teaching material developed is presented from basic competencies of knowledge and basic competencies of learning skills. Based on experiments on developed teaching materials it is known that the average value of the ability to write plays gets a score exceeding the minimum criteria, so that the teaching materials used are effective. Based on observations it is known that teaching materials can help students in learning and student activities become more independent, and active.

SIFAT MEKANIK PAPAN GYPSUM DARI SERBUK LIMBAH KAYU NON KOMERSIAL

2014 ◽  
Vol 6 (2) ◽  
pp. 1
Author(s):  
Saibatul Hamdi
Keyword(s):  
Raw Materials ◽  
Wood Particle ◽  
Quality Standards ◽  
Gypsum Board ◽  
Average Value ◽  
Wood Particles ◽  
Sawn Timber ◽  
Materials Used ◽  
Artocarpus Elasticus ◽  
Ficus Glomerata

The purpose of this research is to know the mechanical strength of gypsum board by utilizing waste sawn wood. Raw materials used consist of flour, gypsum,wood particles, boraks and kambang (Goniothalamus sp), wood tarap (Artocarpus elasticus REINW) and lua (Ficus glomerata ROXB). Wood particle 40 mesh and 60 mesh, concentrations boraks of 1 and 2 and the percentage particles of gypsum sawn timber is 300, 400 and 500%. The results showed that the average value Modulus of Rufture (MoR) in lua wood ranges from 12.55 – 14,47 kgcm2, wood kambang 25.10-31,11 kgcm2 and wood tarap 19.20- 24,18 kgcm2. As for Modulus of Elasticity (MoE) on the lua 1129,80- 2092,70 kgcm2, wood kambang 2512,37-3971,32 kgcm2 and tarap 2050,63-2691,09 kgcm2. Gypsum board are mechanical properties do not meet quality standards created SNI 03-6434-2000.Keywords: sawdust, lua, kambang, tarap, gypsum, mechanical

scholarly journals Warpage Optimisation Using Recycled Polycar-bonates (PC) on Front Panel Housing

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1416
Author(s):  
Nur Aisyah Miza Ahmad Tamizi ◽  
Shayfull Zamree Abd Rahim ◽  
Abdellah El-hadj Abdellah ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Marcin Nabiałek ◽  
...  
Keyword(s):  
Simulation Analysis ◽  
Processing Parameters ◽  
Front Panel ◽  
Processing Parameter ◽  
Mechanical Recycling ◽  
Great Opportunity ◽  
Average Value ◽  
Optimal Processing ◽  
Materials Used ◽  
Optimisation Methods

Many studies have been done using recycled waste materials to minimise environmental problems. It is a great opportunity to explore mechanical recycling and the use of recycled and virgin blend as a material to produce new products with minimum defects. In this study, appropriate processing parameters were considered to mould the front panel housing part using R0% (virgin), R30% (30% virgin: 70% recycled), R40% (40% virgin: 60% recycled) and R50% (50% virgin: 50% recycled) of Polycarbonate (PC). The manufacturing ability and quality during preliminary stage can be predicted through simulation analysis using Autodesk Moldflow Insight 2012 software. The recommended processing parameters and values of warpage in x and y directions can also be obtained using this software. No value of warpage was obtained from simulation studies for x direction on the front panel housing. Therefore, this study only focused on reducing the warpage in the y direction. Response Surface Methodology (RSM) and Genetic Algorithm (GA) optimisation methods were used to find the optimal processing parameters. As the results, the optimal ratio of recycled PC material was found to be R30%, followed by R40% and R50% materials using RSM and GA methods as compared to the average value of warpage on the moulded part using R0%. The most influential processing parameter that contributed to warpage defect was packing pressure for all materials used in this study.

Possible Causes in Breaking of Dental Implants Research

2017 ◽  
Vol 907 ◽  
pp. 104-118
Author(s):  
Maria Stoicănescu ◽  
Eliza Buzamet ◽  
Dragos Vladimir Budei ◽  
Valentin Craciun ◽  
Roxana Budei ◽  
...  
Keyword(s):  
Dental Implants ◽  
Dental Implant ◽  
Scientific Literature ◽  
Surface Characteristics ◽  
Raw Material ◽  
New Materials ◽  
Materials Used ◽  
Type Of Failure ◽  
First Time ◽  
Consequent Increase

Dental implants are becoming increasingly used in current dental practice. This increased demand has motivated manufacturers to develop varieties of product through design, but also looking for new materials used to improve surface characteristics in order to obtain a better osseointegration. But the increase in the use of implants goes to a consequent increase in the number of failures. These failures are caused either by treatment complications (peri-implantitis), by fatigue breakage under mechanical over-stress, by defective raw material, or due to errors during the insertion procedures. Although they are rare, these complications are serious in dentistry. Before to market a dental implant to clinical practitioners, the product is validated among other determinations in number of biocompatibility research. Raw material issues, details about its structure and properties are less published by the scientific literature, but all this are subject of a carefully analysis of the producers. Breaking of dental implants during surgical procedures, during the prosthetic procedures or during use (chewing, bruxism, accidents, etc.), is the second most common cause of loss of an implant after consecutive peri-implantitis rejection. Although the frequency of this type of failure for a dental implant is much smaller than those caused by the peri-implantitis, a detailed study of broken implants can explain possible causes. The use of scanning electron microscopy (SEM) in the study of the cleave areas explain the production mechanism of cleavages, starting from micro-fissures in the alloy used for the production of dental implants. These micro-fissures in weak areas of the implant (anti-rotational corners of the polygons, etc.) could generate a serious risk of cleavage first time when a higher force is applied.

Use of permeable, reservoir pavement constructions for stormwater treatment and storage for re-use

1999 ◽  
Vol 39 (5) ◽  
pp. 145-151 ◽  
Author(s):  
C. J. Pratt
Keyword(s):  
Water Quality ◽  
Urban Areas ◽  
Water Environment ◽  
Cost Savings ◽  
Environmental Benefits ◽  
Stormwater Treatment ◽  
Residential Areas ◽  
Materials Used ◽  
The Uk ◽  
The Impact

Permeable surfaces for roads and footpaths have been used as a means of disposal of stormwater in developed urban areas. Such surfaces provide an alternative to impermeable concrete or tarmacadam surfaces which would otherwise produce rapid stormwater runoff, leading to possible flooding and degeneration of receiving water quality through the uncontrolled discharge of polluted urban waters. A further advantage may be obtained from such constructions by undersealing them so as to retain stormwater for re-use for non-potable uses. The potential for general introduction of this type of storage and re-use system in residential areas is discussed and possible alternative designs for the drainage infrastructure proposed. To have widespread impact such a strategy must deliver cost savings as well as reduce the impact on the water environment of anticipated water usage demands. The source of such cost savings and the general environmental benefits of such systems will be presented. The materials used in such a sealed construction and the beneficial changes to the stored water quality are outlined. Recent work has also shown that where the pavement is used for car parking any oils dropped on the surface and washed into the structure by the stormwater may also be degraded. Details will be given of a site in the UK where the above construction is to be used to provide stormwater storage for re-use in flushing toilets at a Youth Hostel.

PENENTUAN SIFAT KEKUKUHAN DAN KETEBALAN LAPISAN PERMUKAAN BERASFALT MENGGUNAKAN KAEDAH PENCARIAN RESONAN TAMBAHAN (ERS)

2015 ◽  
Vol 76 (1) ◽  
Author(s):  
Nur Mustakiza Zakaria ◽  
Muhammad Fakhry Md. Jaffary ◽  
Muhammad Kamal Hassan ◽  
Asmah Hamim ◽  
Nur Izzi Md. Yusoff ◽  
...  
Keyword(s):  
Elastic Moduli ◽  
Public Works ◽  
Traffic Load ◽  
Average Value ◽  
Resonance Search ◽  
Materials Used ◽  
Pavement Construction ◽  
Pavement Thickness ◽  
Good Agreement

This study was conducted to investigate the stiffness and thicknesses of asphalt surface layer using the Enhance Resonance Search (ERS) technique. A total of fifteen locations in the Universiti Kebangsaan Malaysia (UKM) Campus have been identified to carry out this experiment. The results were then compared with standards provided by the Malaysian Public Works Department (PWD), Jabatan Pembangunan dan Penyelenggaraan (JPP) UKM and Kumpulan IKRAM Sdn. Bhd. The computation found that the range of elastic moduli values of asphalt layer is between 3928.877 and 17726.012 MPa. A comparison between the experiment results and JPP UKM standard on pavement thickness showed that the different is between 20% to 60%, with the average thickness of 44.13 mm.  However, the average value of thickness is still in good agreement with the JKR and JPP UKM standards. Some stiffness values obtained are higher than the standard, probably due to the quality of materials used, the influence of the traffic load and the age of the pavement construction.

scholarly journals Experimental study of materials radiation resistance in reactor mixed fields for the construction of the SPES facility at LNL

2018 ◽  
Vol 48 ◽  
pp. 1860104
Author(s):  
A. Zenoni ◽  
F. Bignotti ◽  
A. Donzella ◽  
G. Donzella ◽  
M. Ferrari ◽  
...  
Keyword(s):  
Ion Source ◽  
Operating Conditions ◽  
Primary Proton ◽  
Radiation Fields ◽  
Nuclear Species ◽  
Elastomeric Materials ◽  
Mixed Field ◽  
Materials Used ◽  
Under Construction ◽  
Mixed Fields

The Selective Production of Exotic Species (SPES) facility, now under construction at Legnaro National Laboratories of INFN, is a second-generation accelerator for the production of neutron-rich ion beams. The radioactive nuclear species are produced by fission of a [Formula: see text]U target, on which a 200[Formula: see text][Formula: see text]A primary proton beam of 40[Formula: see text]MeV energy impinges. Materials and components constituting the Target and Ion Source assembly and the Front-End supporting structure are subjected to serious radioactive damage due to intense neutron and photon fields present under operating conditions. In the framework of the SPES project, experimental campaigns aimed at testing the radiation hardness of critical materials and components of potential use in the construction were started. Irradiations were conducted in a reactor mixed field of neutrons and photons in order to reproduce, as close as possible, the actual environmental service conditions. Results obtained for different types of elastomeric materials used for construction of vacuum O-rings, as well as preliminary results obtained for lubricating oils and greases, are presented. Materials under consideration are both conventional ones as well as materials specifically developed for applications in the presence of ionizing radiation. The latter materials were previously tested mainly in gamma radiation fields.

Active Outer Ring Cooling of High-Loaded and High-Speed Ball Bearings

2013 ◽  
Vol 135 (8) ◽  
Author(s):  
Michael Flouros ◽  
Markus Hirschmann ◽  
Francois Cottier ◽  
Peter Gloeckner ◽  
Klaus Dullenkopf
Keyword(s):  
Heat Generation ◽  
High Speed ◽  
High Rate ◽  
Outer Ring ◽  
Excessive Pressure ◽  
Pressure Losses ◽  
Aero Engine ◽  
Design Characteristics ◽  
Materials Used ◽  
Critical Limits

Bearings for aero engine applications are subjected to a high thermal impact because of the elevated speeds and loads. The high rate of heat generation in the bearing cannot be sustained by the materials used and, in the absence of lubrication, will fail within seconds. For this reason, aero engine bearings have to be lubricated and cooled by a continuous oil stream. The heat that is generated in the bearings through friction is transferred into the oil. Oil itself has limited capabilities and can only remove heat as long as its temperature does not reach critical limits. When the critical limits have been reached or even exceeded, the oil will suffer chemical decomposition (coking) with loss of its properties and subsequently cause a detrimental impact on the rotating machinery. Oil is normally transferred into the bearings through holes in the inner ring, thus taking advantage of the centrifugal forces due to the rotation. On its way through the bearing, the oil continuously removes heat from the inner ring, the rolling elements, and the bearing cage until it reaches the outer ring. Since the oil has already been heated up, its capability to remove heat from the outer ring is considerably reduced. The idea to provide the bearing with an “unlimited” quantity of oil to ensure proper cooling cannot be considered, since an increase in the oil quantity leads to higher parasitic losses (churning) in the bearing chamber and increased requirements on the engine's lubrication system in terms of storage, scavenging, cooling, weight, etc., not mentioning the power needed to accomplish all these. In this sense, the authors have developed a method that would enable active cooling of the outer ring. Similar to fins, which are used for cooling electronic devices, a spiral groove engraved in the outer ring material would function as a fin body with oil instead of air as the cooling medium. The number of “threads” and the size of the groove design characteristics were optimized in a way that enhanced heat transfer is achieved without excessive pressure losses. An experimental setup was created for this reason, and a 167.5-mm pitch circle diameter (PCD) ball bearing was investigated. The bearing was tested with and without the outer ring cooling. A reduction of 50% of the lubricant flow through the inner ring associated with a 30% decrease in heat generation was achieved.

scholarly journals Pengembangan Bahan Ajar Biologi Materi Virus Berbasis SocioScientific Issues (SSI) untuk Meningkatkan Kemampuan Berpikir Kritis Siswa

2021 ◽  
Vol 11 (1) ◽  
pp. 87-104
Author(s):  
Diyana Septiningrum ◽  
Nur Khasanah ◽  
Nur Khoiri
Keyword(s):  
Critical Thinking ◽  
Thinking Skills ◽  
Critical Thinking Skills ◽  
Teaching Material ◽  
Teaching Materials ◽  
Average Value ◽  
Teachers And Students ◽  
The Difference ◽  
Materials Used ◽  
Expert Validation

The purpose of research is to know the characteristics, feasibility and effectiveness of developing teaching materials viruses based on Socio-Scientific Issues (SSI) to improve critical thinking skills. Research method using Research and Development (RD) with a 4D step (define, design, develop, disseminate) Thiagarajan et all. The subjects of the study are 34 students class X MIPA 1 as the experimental class and 34 students class X MIPA 4 as the control class. The eligibility of teaching material is derived from the results of expert validation questionnaires, responses of biology teachers and students' responses, and effectiveness of critical thinking skills from the results of the test questions pretest and posttest. The results of the characteristics teaching material viruses based SSI include: cover, introduction, news analysis, material, summary, evaluation, bibliography and glossary. The results of the eligibility from the material expert validation questionnaire were 88,67%, 94,67% of media experts, 83,55% of teacher responses and 82,29% of students' responses. The effectiveness of teaching materials used was obtained from the difference in the average value of experimental learning outcomes of 81.84 and 76.84 kontrol class with tcount = 4.338 and ttable = 1.6682 which means tcount ttable and Ha accepted, concluded that there were differences in posttest results experimental class with kontrol class. The n-gain results obtained the value of the experimental class of 0.63 and the control class of 0.54 with their respective categories being moderate. So it can be concluded that the use of biological material teaching material based on Socio-Scientific Issues (SSI) is effective to improve students' critical thinking skills class X SMA 12 Semarang.

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