Optimization for Biodegradability of Polylactic Acid by Using Taguchi Design of Experimental Methodology

2012 ◽  
Vol 622-623 ◽  
pp. 99-102
Author(s):  
Shu Wen Wang ◽  
Te Li Su
Keyword(s):  
Confidence Interval ◽  
Polylactic Acid ◽  
Experimental Methodology ◽  
Parameter Design ◽  
Hydrolysis Rate ◽  
Optimal Conditions ◽  
Effect Analysis ◽  
Main Effect ◽  
Hydrolysis Conditions ◽  
Significant Factors

The purpose of this research is to raise the initial hydrolysis rate of polylactic acid (PLA) during the entire decomposing process, and then enhance the decomposition rate of PLA in natural environment. This research uses Taguchi method to do the parameter design of PLA hydrolysis. And then main effect analysis is applied to find out the significant factors and the optimal hydrolysis conditions for PLA. By the results of the confirmation experiments, the optimal conditions of the PLA hydrolysis rate got by these experiments are all located on the 95% confidence interval. This indicates that these experiments are with reproducibility and reliability.

Improving the Biodegradability of Polylactic Acid at Alcaligenes Faecalis and Staphylococcus Aureus Using the Optimization Method

2013 ◽  
Vol 743 ◽  
pp. 213-217
Author(s):  
Shu Wen Wang ◽  
Te Li Su
Keyword(s):  
Polylactic Acid ◽  
Analysis Of Variance ◽  
Early Stage ◽  
Degradation Process ◽  
Optimization Method ◽  
Alcaligenes Faecalis ◽  
Hydrolysis Rate ◽  
Control Factors ◽  
Hydrolysis Conditions ◽  
Significant Factors

The degradation of polylactic acid (PLA) can be divided into the hydrolysis, the degradation and metabolism. The hydrolysis reaction is caused by chain breakdown of the polymers of polylactic acid, resulting in the degradation of polylactic acid. Therefore, this study aims to improve the hydrolysis rate of PLA at the early stage of degradation process and then it increases the degradation rate of the PLA in the natural environment. We employed Taguchi method for parameter design of PLA hydrolysis, focusing on the control factors that affect the conditions of the hydrolysis rate of PLA, such as temperature, bacteria, ventilation degree, and nutrients and we also used orthogonal array to precede experiments, in conjunction with analysis of variance (ANOVA) to identify significant factors and optimal hydrolysis conditions for PLA. By analysis of variance, we know that temperature and bacteria as significant factors, and the factor of temperature contributed 96.882%. Finally, we employed confirmation Experiment to verify the reproducibility of the experiments. Our results have shown that the best condition of PLA hydrolysis rate experience with the reliability of its representatives are in compliance with the 95% of confidence interval, CI, which indicates the reliability of our study.

Quality Improvement of Nonwoven Facial Mask by Using Taguchi Methodology

2012 ◽  
Vol 548 ◽  
pp. 870-874
Author(s):  
Te Li Su
Keyword(s):  
Optimal Combination ◽  
Parameter Design ◽  
Taguchi Methodology ◽  
Effect Analysis ◽  
Facial Mask ◽  
Control Factors ◽  
Confirmation Test ◽  
Main Effect ◽  
Significant Factors

Among facial masks, the nonwoven facial mask is most popular. So how to enhance the quality of nonwoven facial mask is important for promoting competitiveness. Therefore, the purpose of this study is to find out the optimal combination of parameters of hot wheel press. First, Taguchi methodology was used to carry out parameter design and chooses the parameters of hot wheel press that would affect the quality of nonwoven facial mask as the experimental control factors; and then selects an appropriate orthogonal array to perform the experiments. In addition, by executing with main effect analysis, it is able to decide upon the optimal combination of parameters of hot wheel press and the significant factors of the nonwoven facial mask, and then applying the confirmation test to verify the experimental reliability and reproducibility.

Optimizing Experimental Variables to Enhance the Biodegradability of Polylactic Acid

2014 ◽  
Vol 472 ◽  
pp. 815-819
Author(s):  
Shu Wen Wang ◽  
Te Li Su
Keyword(s):  
Carbon Dioxide ◽  
Taguchi Method ◽  
Polylactic Acid ◽  
Renewable Resources ◽  
Raw Materials ◽  
Parameter Design ◽  
Hydrolysis Rate ◽  
Biodegradable Materials ◽  
Optimal Conditions ◽  
Control Factors

Polylactic acid (PLA), the biodegradable materials, mainly using biobase as raw materials, is the biodegradable polyester manufactured with fermentation and chemical synthesis, or polymerization of monomers from petrochemical products. The polymer usually made with the renewable resources, such as microorganism, plants and animals, will be decomposed into water and carbon dioxide if the natural landfill or compost environment has sufficient moisture, temperature, oxygen and suitable microorganism. Therefore, this paper aims to improve the hydrolysis rate of the PLA during the whole decomposition process and to increase the decomposition rate of PLA in the natural environment. In this paper, Taguchi method was used for the parameter design of PLA hydrolysis and focusing on choosing the conditions that would affect PLA hydrolysis as control factors, for example, temperature, bacteria, ventilation degree and nutrient. Meanwhile, the experiment was conducted with L8 orthogonal array and analysis of variance to find out the significant factor and the optimal conditions of PLA hydrolysis. We found the temperature and bacteria are signify factors by the variance. Lastly, confirmation experiments verified the reproducibility of this experiment. Confirmed by the experiments, results showed that the obtained SN ratios were greater than the rate of eight PLA hydrolysis experiments and this means the experiment is reliable.

The impact of acid hydrolysis conditions on carbohydrate determination in lignocellulosic materials: a case study with Eucalyptus globulus bark

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ricardo Jorge Oliveira ◽  
Bruna Santos ◽  
Maria J. Mota ◽  
Susana R. Pereira ◽  
Pedro C. Branco ◽  
...  
Keyword(s):  
Acid Hydrolysis ◽  
Eucalyptus Globulus ◽  
Industrial Processes ◽  
Lignocellulosic Materials ◽  
Optimal Conditions ◽  
Hydrolysis Conditions ◽  
The Impact ◽  
Eucalyptus Bark

Abstract Lignocellulosic biomass represents a suitable feedstock for production of biofuels and bioproducts. Its chemical composition depends on many aspects (e.g. plant source, pre-processing) and it has impact on productivity of industrial bioprocesses. Numerous methodologies can be applied for biomass characterisation, with acid hydrolysis being a particularly relevant step. This study intended to assess the most suitable procedures for acid hydrolysis, taking Eucalyptus globulus bark as a case study. For that purpose, variation of temperature (90–120 °C) was evaluated over time (0–5 h), through monosaccharides and oligosaccharides contents and degradation. For glucose, the optimal conditions were 100 °C for 2.5 h, reaching a content of 48.6 wt.%. For xylose, the highest content (15.2 wt.%) was achieved at 90 °C for 2 h, or 120 °C for 0.5 h. Maximum concentrations of mannose and galactose (1.0 and 1.7 wt.%, respectively) were achieved at 90 and 100 °C (2–3.5 h) or at 120 °C (0.5–1 h). These results revealed that different hydrolysis conditions should be applied for different sugars. Using this approach, total sugar quantification in eucalyptus bark was increased by 4.3%, which would represent a 5% increase in the ethanol volume produced, considering a hypothetical bioethanol production yield. This reflects the importance of feedstock characterization on determination of economic viability of industrial processes.

Multiple drug effect analysis with confidence interval

1994 ◽  
Vol 25 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Mikhail S. Belen'kii ◽  
Raymond F. Schinazi
Keyword(s):  
Confidence Interval ◽  
Drug Effect ◽  
Multiple Drug ◽  
Effect Analysis

Enhanced surface hydrophilicity of polylactic acid sutures treated by lipase and chitosan

2018 ◽  
Vol 89 (16) ◽  
pp. 3291-3302 ◽  
Author(s):  
Shuqiang Liu ◽  
Mingfang Liu ◽  
Gaihong Wu ◽  
Xiaofang Zhang ◽  
Juanjuan Yu ◽  
...  
Keyword(s):  
Reaction Time ◽  
Friction Coefficient ◽  
Surface Area ◽  
Polylactic Acid ◽  
The Body ◽  
Optimal Conditions ◽  
Absorbable Sutures ◽  
Surgical Sutures ◽  
New Type ◽  
Enhanced Surface

Polylactic acid (PLA) surgical sutures are a new type of absorbable sutures that can be degraded and absorbed in the body. However, there is high hydrophobicity for the surface of PLA sutures, which leads to poor biocompatibility and cellular affinity. In order to increase the hydrophilicity, the PLA sutures were etched by lipase firstly, and then grafted with chitosan. The results indicate that the optimal conditions of treating PLA sutures by lipase were as follows: 45℃ reaction temperature, 4.5 g/L concentration of lipase and 8 h reaction time. The sutures were etched by lipase and then formed some grooves and a number of hydroxyl (-OH) bonds, which led to increased surface area and hydrophilicity, but a drop in mass and strength. The optimal conditions of grafting chitosan onto PLA sutures were as follows: 4 h reaction time and 3 g/L concentration of chitosan. The chitosan grafted and loaded on the surface of PLA sutures, and in some areas of the sutures the chitosan reunited, which led to a rough surface and large friction coefficient. Finally, the hydrophilicity of the PLA sutures, treated by lipase and then grafted with chitosan, was greatly improved.

Factors Associated With Suicidal Attempt Among School-Going Adolescents in Malaysia

2019 ◽  
Vol 31 (8_suppl) ◽  
pp. 73S-79S
Author(s):  
Fazly Azry Abdul Aziz ◽  
Mohamad Aznuddin Abd Razak ◽  
Noor Ani Ahmad ◽  
S. Maria Awaluddin ◽  
Noor Aliza Lodz ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Multiple Logistic Regression Analysis ◽  
Holistic Approach ◽  
Suicidal Attempt ◽  
Public Health Policies ◽  
Factors Associated ◽  
School Based ◽  
Parental Connectedness ◽  
The Relationship ◽  
Significant Factors

Various factors contribute to suicidal attempt. This study aims to determine the relationship between suicidal attempt and its associated factors among school-going adolescents in Malaysia. Data from the National Health and Morbidity 2017 survey were analyzed. This survey was implemented as a nationwide school-based survey targeting adolescents 13 to 17 years old. Descriptive and multiple logistic regression analysis was done using SPSS version 20. A total of 27 399 adolescents participated in this survey. The prevalence of suicidal attempt was 6.9% (95% confidence interval = 6.2-7.7). Multivariate analysis found that the odds of suicidal attempt among adolescent with depression is 4.3 (adjusted odds ratio = 4.3; 95% confidence interval = 3.9-4.8). Other significant factors are young adolescent, non-Malay ethnicities especially Indian, adolescent with parents living apart, and those without peer support and parental connectedness. A holistic approach for the planning of preventative strategies and public health policies should be made according to these risk factors.

Optimal Conditions of Electrostatic Spray Deposition (ESD) for Composite Biomaterials Coating for Biomedical Applications

2013 ◽  
Vol 748 ◽  
pp. 175-179 ◽  
Author(s):  
Wasawat Nakkiew
Keyword(s):  
Feed Rate ◽  
Spray Deposition ◽  
Calcium Phosphates ◽  
Vacuum Furnace ◽  
Optimal Conditions ◽  
Electrostatic Spray Deposition ◽  
Air Volume ◽  
Coated Layer ◽  
Electrostatic Spray ◽  
Significant Factors

Various types of metals and alloys are used for medical implants due to their excellent mechanical properties and corrosion resistance; however, their lacks of osteoinductive properties bring about the introduction of biomaterials which can help enhancing the bioactivity between the bones and the implants. Hydroxyapatite (Ca10(PO4)6(OH)2, or HA) which is one of the calcium phosphates that has similar mineral constituents of human bone, has been used as coating material to the metals/alloys substrate. Coating HA usually involves high-temperature such as the plasma spraying coating, which can alter the crystal structure of the HA partially become amorphous. The amorphous nature of HA lessen the benefits of coating with the biomaterial HA. Electrostatic spray deposition (ESD) was used in this research due to the fact that this process is simple, economical, and room-temperature operated. The preliminary results showed a promising thickness layer of about 40 μm; however, the adhesion of the coated layer to the stainless steel 316L was improved by mixing the HA powder with phosphate bioglass and cured in the vacuum furnace at 700oC. Taguchi experimental design technique was used for screening several ESD process parameters: powder feed rate, voltage, current, air volume, distances, time, and nozzle types to significant factors to the coated thickness of the ESD process. The results showed that feed rate, air volume, and time were the significant factors and then Full factorial analysis and response surface method was used for obtaining optimal conditions for the coating, as well as the predicted equation for determine the thickness coated layer with significant factors.

scholarly journals Sex-specific in the relationship between hyperuricemia and pulse pressure in non-diabetic Korean adults: the 2017 Korean National Health and Nutrition Examination Survey

2021 ◽  
Keyword(s):  
Blood Pressure ◽  
Uric Acid ◽  
Confidence Interval ◽  
National Health ◽  
Pulse Pressure ◽  
Nutrition Examination Survey ◽  
Korean Adults ◽  
Health And Nutrition ◽  
The Relationship ◽  
Significant Factors

Background and objective: The present study assesses the relationship between hyperuricemia and pulse pressure (PP) in non-diabetic Korean adults. Material and methods: Data from 5122 subjects (2251 men and 2871 women) in the seventh Korean National Health and Nutrition Examination Survey (KNHANES VII-2, 2017) were analyzed. Results: Systolic blood pressure (SBP) and PP were significant factors determining the odds ratios (ORs) for hyperuricemia (uric acid ≥7.0 mg/dL in men or ≥6.0 mg/dL in women) in men and the overall population. In women, SBP, diastolic blood pressure (DBP), and PP were not significant factors determining the OR for hyperuricemia. After adjusting for related variables, the OR of hyperuricemia was significantly higher in the high PP group (PP >60.0 mmHg) for men (OR, 1.760; 95% confidence interval [CI], 1.152--2.688) and the overall population (OR, 1.557; 95% CI, 1.132--2.140) compared with the normal PP group, but this trend was not seen in women (OR, 1.060; 95% CI, 0.646--1.740). Conclusions: Hyperuricemia was positively associated with PP in non-diabetic Korean men but not in women.

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