scholarly journals Effect of Pressure, Post-Pressing Time, and Polymerization Cycle on the Degree of Conversion of Thermoactivated Acrylic Resin

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Rafaella de S. Leão ◽  
Sandra L. D. de Moraes ◽  
Kátia A. da S. Aquino ◽  
Cristina P. Isolan ◽  
Bruno G. da S. Casado ◽  
...  
Keyword(s):  
Statistical Tests ◽  
Acrylic Resin ◽  
Influential Factors ◽  
Degree Of Conversion ◽  
Short Cycle ◽  
Long Cycle ◽  
Experimental Planning ◽  
Thermally Activated ◽  
Pressing Time ◽  
Margin Of Error

Herein, the effect of different post-pressing times and pressure in two cycles of polymerization on the degree of conversion (DC) of thermally activated acrylic resin (TRRA) is analyzed to optimize the polymerization of this material. After post-pressing for 0, 6, or 12 h, polymerization was performed with or without a pressure of 60 psi (0.41 MPa) in a short (4 h) or a long (11 h) cycle, totaling 12 groups. To determine the DC, PMMA specimens were analyzed by Fourier transform infrared spectroscopy. The influence of each factor alone on the DC was studied by experimental planning. The statistical tests used were three-way ANOVA, t-test, Tukey’s test, and Levene’s test, with a margin of error of 5%. Two groups prepared with post-pressing times of 12 h had the lowest DC (p<0.001). Post-pressing times of 0 and 6 h did not yield statistically different results. Pressure increased the DC in only one group (long cycle +12 h, p=0.001). The short cycle resulted in a higher DC than the long cycle in 2 groups (with pressure +0 h, p=0.002; without pressure +6 h, p=0.015), while the long cycle yielded a statistically higher DC in only one group (with pressure +12 h, p<0.001). The polymerization showed satisfactory DC in all 12 groups. Small differences found among the specimens indicate that the pressure, post-pressing time, and polymerization cycles herein were not influential factors for the DC of PMMA.

scholarly journals Creativity in Design Engineers: Attitudes, Opinions and Potentially Influential Factors

2017 ◽  
Author(s):  
Paul Neufeld ◽  
Omid Mirzaei ◽  
Mark Runco ◽  
Sean Maw
Keyword(s):  
Online Survey ◽  
Engineering Students ◽  
Statistical Tests ◽  
Initial Study ◽  
Influential Factors ◽  
Measurement Tool ◽  
Engineering Programs ◽  
Design Engineers ◽  
Creativity Research ◽  
College Of Engineering

Is creativity important in engineering design? If it is, then why do most undergraduate engineering programs spend so little time teaching creativity? And therefore, as a result of our programs, do our students emerge more creative, less creative or no different compared to when they arrived? If creativity is worth developing, can we accurately measure it in our students, and can we enhance it systematically?These were some of the questions that motivated the initiation of a creativity research program in the College of Engineering at the University of Saskatchewan. The assumption was that creativity is important in engineering, especially in design. The intent was to understand how we could assess creativity in our students and then enhance it.The focus of this initial study is a precursor to many of these more applied questions. We had students and faculty from a variety of Colleges, including Engineering, answer an online survey that probed attitudes towards creativity, respondent personality characteristics, opinions regarding conditional influences on creativity, and potential demographic factors influencing the creativity of individuals. As well, we employed a validated creativity attitudes and beliefs measurement tool (rCAB) as an accepted benchmark for assessment.The survey included both closed- and open-ended questions. The results from some of the open-ended questions have been analyzed to determine emerging groups of similar types of answers, and then efforts have been made to relate the groups in a meaningful framework.The results for the Engineering students are emphasized, but they are also compared with students and faculty from other Colleges. Closed questions were analyzed using inferential statistical tests (distributions, means, standard deviations, t-tests, ANOVA, Cronbach’s alpha), while the open-ended responses are compared more qualitatively when they cannot be quantified easily.The survey went through ethics approval and was distributed in the latter half of the Fall 2015 term.

scholarly journals The study of effective factors on some of the biologic rhythms from the view point of hospitalized patients

2011 ◽  
Vol 1 (1) ◽  
pp. 14-16
Author(s):  
SH Najafi Doulatabad ◽  
A Najafi Doulatabad ◽  
SJ Sadat ◽  
Z Mohebbi Nobandegani
Keyword(s):  
Occupational Safety ◽  
Statistical Tests ◽  
Biological Rhythms ◽  
Influential Factors ◽  
Hospitalized Patients ◽  
Point Of View ◽  
Personal Factors ◽  
Effective Factors ◽  
Hospitalization Period ◽  
Medical Wards

Many human vital actions like sleep and waken, defecation, blood pressure, body temperature, etc. are being done as rhythmic. The factors on these rhythms among hospitalized patients in the hospitals can outshine the patients recovery and hospitalization period so, the present research has been performed with the aim to study of the effective factors on some biological rhythms from point of view of hospitalized patients at medical ward of the Emam Sajad hospital of Yasouj city 2008-2009. This research is a descriptive sectional study, performed on hospitalized patients at medical wards of hospitals of Yasouj city during the years 2008-2009. Sampling method was as purposive accessible sampling and the numbers of samples were 100.0 persons. The data collection tool was questionnaire. Collected data were analyzed using SPSS software and descriptive statistical tests. 68.0% and 83.0% of samples were suffering from sleep reduction and anorexia respectively. 61.0% of samples also mentioned some change in their defecation. Among environmental factors, noise in the ward with 65.0%, among personal factors, anxiety regarding recovery and obtaining health with 60.0% and among caring factors, having serum and keep awake to receive medicine with 57.1% have been effective on the sleep reduction of patients with the rates of very much and much. Regarding the effective factors on appetite reduction of patients, smelly environment and undesirable food with 21.0% each, were among the most influential factors. Regarding the effective factors on defecation reduction also lack of activity with 25.5% had the maximum role. Since the most important effective factors in biologic rhythms which are under studying are adjustable and it is possible to remove them therefore, it is necessary for the caring personnel to prepare the rest possibility and comfortability of patients in desirable manner by more accuracy and removing such factors and giving education to the patients. Key Words: Sleep; Appetite; Defecation; Biologic rhythms; Patients. DOI: http://dx.doi.org/10.3126/ijosh.v1i1.4379 International Journal of Occupational Safety and Health, Vol 1 (2011) 14-18

scholarly journals Optimization of cropping pattern and stocking density for production of brackishwater shrimp, Penaeus monodon

2016 ◽  
Vol 44 (1) ◽  
pp. 31-40
Author(s):  
SB Saha ◽  
Shamsun Nahar ◽  
Azhar Ali ◽  
SL Rahman
Keyword(s):  
Production Management ◽  
Penaeus Monodon ◽  
Stocking Density ◽  
Cost Ratio ◽  
Cropping Pattern ◽  
Gross Margin ◽  
Short Cycle ◽  
Cropping Patterns ◽  
Long Cycle ◽  
Benefit Cost Ratio

An experiment was conducted to develop a culture system for producing brackishwater shrimp, Penaeus monodon, at a management strategy affordable for marginal to medium farmers. Shrimp was produced by two cropping patterns viz., short cycle (60 days) double crops and long cycle (120 days) single crop each at three stocking densities viz., 3, 5, 7 nos./m2. The analysis of results revealed that production of shrimp of 913.57 - 1429.38 kg/ha in long cycle single crop was higher than that of 804.42 - 1296.87 kg/ha in aggregate of short cycle double crops at 3 - 5 nos./m2 density, but at 7 nos./m2 density, production of shrimp of 1899.39 kg/ha was higher in short cycle double crops than that of 1857.31 kg/ha in long cycle single crop. The differences in production between two cropping patterns at different densities were not significant. Gross margin was higher in high stocking ponds in both short and long cycle cropping pattern and it was 1.75 - 2.24 times higher in long cycle culture than that short cycle culture. However, considering higher benefit cost ratio and requirement of supply of oxygen for the production management, it can be surmised that production of shrimp in short cycle double crops at 5 nos./m2 densities will be better affordable for marginal to medium farmers having limited resource.Bangladesh J. Zool. 44(1): 31-40, 2016

Method for Identifying Factors Contributing to Driver-Injury Severity in Traffic Crashes

2000 ◽  
Vol 1717 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Wan-Hui Chen ◽  
Paul P. Jovanis
Keyword(s):  
Injury Severity ◽  
Statistical Tests ◽  
Selection Procedure ◽  
Weather Conditions ◽  
Early Morning ◽  
Influential Factors ◽  
Complex Nature ◽  
Crash Data ◽  
Late Night ◽  
Log Linear

Numerous driver, vehicle, roadway, and environmental factors contribute to crash-injury severity. In addition to main effects, interactions between factors are very likely to be significant. The large number of potentially important factors, combined with the complex nature of crash etiology and injury outcome, present significant challenges to the safety analyst, who must select from a large number of factors and specify a comprehensive but feasible set of main factors and interactions for testing in statistical models. In addition, some factors contain a relatively large number of categories (e.g., weather conditions), and the selection of cut-off points for categorization of continuous factors may not be readily obvious (e.g., driver age). It is also important that statistical tests underlying these analyses accurately address the frequent problem of data sparseness. The development and testing of a variable-selection procedure to address each of these problems is the stated objective. Bus-involved crash data for Freeway 1 in Taiwan from 1985 through 1993 were used to screen a set of 39 possible influential factors, along with interactions. The final log-linear model shows that late-night or early-morning driving increases the risk for bus drivers of being severely injured, particularly when the drivers caused the accident or when the drivers were involved in rear-end accidents. Bus accidents involving large trucks or tractor-trailers also increase the risk. An assessment of the importance of considering interactions in crash models is presented as a conclusion.

The Runoff Forecasting Model Based on Wavelet Adaptive Neural Fuzzy Inference System

2012 ◽  
Vol 182-183 ◽  
pp. 1032-1040 ◽  
Author(s):  
Jun Fang Gu ◽  
Xiao Li Wang ◽  
Fu Hui Du
Keyword(s):  
Fuzzy Inference System ◽  
Fuzzy Inference ◽  
Wavelet Packet ◽  
Inference System ◽  
Short Cycle ◽  
Long Cycle ◽  
Mallat Algorithm ◽  
Runoff Prediction ◽  
Runoff Forecast ◽  
Neural Fuzzy

Considering various the wavelet decomposition reconstruction technology and training cycle of adaptive neural fuzzy inference system, this article propose four runoff forecast model of wavelet analysis and adaptive neural fuzzy inference system integration, such as the long cycle based on Mallat algorithm in runoff prediction, the long cycle based on wavelet packet algorithm in runoff prediction, the short cycle based on Mallat algorithm in runoff prediction, the short cycle based on wavelet packet algorithm in runoff prediction, and illuminate the model of the principles, structures and procedures. This model is used in Tangnaihe station monthly runoff forecast which lies in the Huanghe source area. Simulation results are evaluated by the cycle decomposition coefficients and Nash-Sutcliffe coefficient; it shows that the long cycle based on Mallat algorithm is best, the short cycle based on wavelet packet algorithm is worst. The author analyzes the reason and makes some proposal.

scholarly journals Effect of sodium hypochlorite and peracetic acid on the surface roughness of acrylic resin polymerized by heated water for short and long cycles

2014 ◽  
Vol 08 (04) ◽  
pp. 533-537 ◽  
Author(s):  
Felipe Sczepanski ◽  
Claudia Roberta Brunnquell Sczepanski ◽  
Sandrine Bittencourt Berger ◽  
Rafael Leonardo Xediek Consani ◽  
Alcides Gonini-Júnior ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Sodium Hypochlorite ◽  
Peracetic Acid ◽  
Acrylic Resin ◽  
Deionized Water ◽  
Polymerization Time ◽  
Colorimetric Analysis ◽  
Short Cycle ◽  
Heated Water ◽  
Long Cycles

ABSTRACT Objective: To evaluate the surface roughness of acrylic resin submitted to chemical disinfection via 1% sodium hypochlorite (NaClO) or 1% peracetic acid (C2H4O3). Materials and Methods: The disc-shaped resin specimens (30 mm diameter ×4 mm height) were polymerized by heated water using two cycles (short cycle: 1 h at 74°C and 30 min at 100°C; conventional long cycle: 9 h at 74°C). The release of substances by these specimens in water solution was also quantified. Specimens were fabricated, divided into four groups (n = 10) depending on the polymerization time and disinfectant. After polishing, the specimens were stored in distilled deionized water. Specimens were immersed in 1% NaClO or 1% C2H4O3 for 30 min, and then were immersed in distilled deionized water for 20 min. The release of C2H4O3 and NaClO was measured via visual colorimetric analysis. Roughness was measured before and after disinfection. Roughness data were subjected to two-way ANOVA and Tukey's test. Results: There was no interaction between polymerization time and disinfectant in influencing the average surface roughness (Ra, P = 0.957). Considering these factors independently, there were significant differences between short and conventional long cycles (P = 0.012), but no significant difference between the disinfectants hypochlorite and C2H4O3 (P = 0.366). Visual colorimetric analysis did not detect release of substances. Conclusion: It was concluded that there was the difference in surface roughness between short and conventional long cycles, and disinfection at acrylic resins polymerized by heated water using a short cycle modified the properties of roughness.

scholarly journals PENGARUH PENGETAHUAN PERPAJAKAN TERHADAP KEPATUHAN PAJAK PADA SELF ASSESSMENT SYSTEM DI INDONESIA

2021 ◽  
Vol 16 (1) ◽  
pp. 133
Author(s):  
Arif Nugrahanto
Keyword(s):  
Statistical Tests ◽  
Tax Compliance ◽  
Influential Factors ◽  
Assessment System ◽  
Tax Revenue ◽  
Linear Regression Method ◽  
Self Assessment ◽  
Compliance Behavior ◽  
The Government ◽  
The Relationship

<p><em>In the last few decade, the government still faces the problem of low tax revenue. The low level of tax compliance is an issue that is often discussed. In the self-assessment system, the responsibility for fulfilling tax obligations lies in the taxpayer side then the knowledge and comprehension of taxation matter is very substantial. This study aims to identify the relationship between tax knowledge and tax compliance behavior. Furthermore, it also attempts to map the situation of tax knowledge and tax compliance behavior in Indonesian. Through statistical tests with the multiple linear regression method based on a survey involving 260 respondents at a national scale, it is found that knowledge related to tax regulations significantly has influenced tax compliance behavior. Moreover, stepwise regression has identified the two most influential factors, there are knowledge of tax objects and knowledge of tax penalties. In addition, the t-test and MANOVA test prove that the ownership of NPWP, education level, occupation, and income significantly influence the tax knowledge.</em></p>

scholarly journals Effect of aluminum oxide powder reinforcement on degree of conversion, monomer release and flexural strength of heat-cured acrylic resin

2020 ◽  
Vol 1 (3) ◽  
pp. 01-05
Author(s):  
Ibrahim M. Hamouda ◽  
Alaa Makke
Keyword(s):  
Flexural Strength ◽  
Aluminum Oxide ◽  
Negative Correlation ◽  
Acrylic Resin ◽  
Oxide Powder ◽  
Degree Of Conversion ◽  
Denture Base ◽  
Positive Correlation ◽  
Aluminum Oxide Powder ◽  
Base Materials

Objectives: Effect and correlation of aluminum oxide powder on degree of conversion, residual monomer and flexural properties of heat-cured acrylic resin specimens were studied. Materials and methods: Heat-cured acrylic resin and aluminum oxide powders were used. Specimens of specific dimensions from unreinforced and reinforced acrylic resins using stainless steel plates were prepared. Degree of conversion was determined using FTIR Spectrometer. Released monomer was measured using isocratic high-performance liquid chromatography. Flexural strength was tested using three point-bending test. Results: Aluminum oxide reinforcement showed increased degree of conversion than that of the unreinforced specimens. Released monomer from reinforced specimens was lower than that of unreinforced specimens. Deflection at fracture of reinforced specimens was lower than that of unreinforced specimens. Flexural strength was increased by addition of 2.5 % and 5% aluminum oxide. There was a positive correlation between degree of conversion and flexural strength. There was a negative correlation between degree of conversion and monomer release. Conclusions: Aluminum oxide powder increased degree of conversion and flexural strength but reduced monomer release and deflection at fracture. There was a positive correlation between degree of conversion and flexural strength. There was a negative correlation between degree of conversion and monomer release. Clinical relevance: Aluminum oxide powder could reinforce the week acrylic resin denture base materials. Degree of monomer conversion during processing of acrylic resin denture base materials is very critical in determination of monomer release and mechanical properties of acrylic resin in service.

scholarly journals Some influential factors on severity of diabetic foot ulcers and Predisposing of limb amputation: A 7-year study on diabetic patients

2019 ◽  
Vol 10 (1) ◽  
pp. 75-81
Author(s):  
Mostafa Madmoli ◽  
Yaghoob Madmoli ◽  
Hosein Taqvaeinasab ◽  
Mahboobeh Khodadadi ◽  
Pouriya Darabiyan ◽  
...  
Keyword(s):  
Diabetic Foot ◽  
Statistical Tests ◽  
Laboratory Data ◽  
Influential Factors ◽  
Limb Amputation ◽  
Foot Ulcers ◽  
Diabetic Patients ◽  
Diabetic Foot Ulcers ◽  
History Of ◽  
The Relationship

Introduction: Diabetes is the most common metabolic disease and a major global challenge that is the leading cause of death in the industrialized and developing world. Therefore, this study was performed on some influential factors on severity of diabetic foot ulcers and predisposing of limb amputation. Materials and Methods: In this cross-sectional descriptive-analytic study, 4436 cases of diabetic patients admitted to Khatam-ol-Anbia hospital of Shoushtar from 2010 to 2016 were studied. The data in this study included three sections: demographic information, ulcer severity based on Wagner’s criterion, and clinical and laboratory data. Then data were analyzed using descriptive and analytical statistical tests. Results: This study included 4436 patients with diabetes with a mean age of 54.36 ± 42.68 years. 421 patients (9.4 percent) had a history of diabetic foot ulcers. Also, 385 patients (8.6%) had a history of limb amputation. In this study, 596 patients (13.4%) had a history of smoking and the relationship between smoking and drug use with the severity of ulcer was significant (p = 0.006). In this study, in the majority of patients with diabetic foot ulcers (60.3%) had severity of ulcer based on Wagner’s criterion was second grade. In terms of bacteriology, 57.7% of the patients during the admission period had cultures of the ulcer site discharge, that the most commonly of mass in 26.7% of cases was Staphylococcus aureus. In this study, the relationship between type of bacteria and severity of ulcer and limb amputation was significant (P <0.05), This means that the ulcers that had negative coagulase-staphylococcus bacteria, were higher the severe ulcer and amputations.  Conclusion: In this study, the relationship between type of bacteria and severity of ulcer and limb amputation was significant, this means that the ulcers that had negative coagulase-staphylococcus bacteria, were higher the severe ulcer and amputations.  

scholarly journals Participatory Ergonomics Training in the Manufacturing Sector and Ergonomic Analysis Tools

2002 ◽  
Vol 56 (3) ◽  
pp. 491-515 ◽  
Author(s):  
Marie St-Vincent ◽  
Monique Lortie ◽  
Denise Chicoine
Keyword(s):  
Manufacturing Sector ◽  
Job Analysis ◽  
Short Cycle ◽  
Participatory Ergonomics ◽  
Long Cycle ◽  
Repetitive Tasks ◽  
Analysis Tools ◽  
Ergonomic Analysis

Summary This article discusses the importance of job analysis tools for training in the context of participatory ergonomic processes. It explains the major principles and challenges in the design of these tools for short-cycle repetitive tasks and for long-cycle varied tasks. The intervention framework is described and the proposed tools are presented and related to the literature. The participants’ difficulties with the tools developed in both contexts studied are summarized. The discussion suggests that these difficulties are partly related to the company context and raises questions about the data relevant for the evaluation of solutions in the case of non-repetitive tasks.

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