Evaluating the deposition quality of parts produced by an open-source 3D printer

2017 ◽  
Vol 23 (4) ◽  
pp. 796-803 ◽  
Author(s):  
Leonardo Santana ◽  
Carlos Henrique Ahrens ◽  
Aurélio da Costa Sabino Netto ◽  
Cassiano Bonin
Keyword(s):  
Lactic Acid ◽  
Process Parameters ◽  
Poly Lactic Acid ◽  
Processing Conditions ◽  
Mass Measurements ◽  
Content Type ◽  
Factors Affecting ◽  
Flexural Tests ◽  
Feedstock Material

Purpose The purpose of this study is to analyze the factors affecting the deposition of parts manufactured in poly(lactic acid) with variations in print speed and extrusion temperature. Specimens were analyzed through optical microscopy, mass measurements and flexural tests. The extruder-head evaluation consisted of monitoring the feedstock material displacement on entering the system during deposition under different processing conditions. Design/methodology/approach To analyze the factors affecting the deposition, parts were manufactured in poly(lactic acid) with variations in print speed and extrusion temperature. Specimens were analyzed through optical microscopy, mass measurements and flexural tests. The extruder-head evaluation consisted of monitoring the feedstock material displacement on entering the system during deposition under different processing conditions. Findings The results showed low repeatability in the manufacturing of parts, as significant variations in the evaluated responses were found for specimens built under the same process parameters. The main cause for this effect was deposition failure, owing to filament slippage in the extruder head hobbed pulley. Practical implications The results found should alert users to the fact that performance tests need to be carried out on every subcomponent of the equipment before conducting experiments on printing parameters. The components of the equipment can influence the final quality of the parts obtained as much as the building parameters and this influence can be significant enough to overlap with that of the process parameters. Originality/value The effect of slippage on the deposition quality was quantified and the command loss in the machine control board was identified.

Quality of life in breast cancer sufferers

2016 ◽  
Vol 29 (7) ◽  
pp. 721-732 ◽  
Author(s):  
Ahmed Essmat Shouman ◽  
Nahla Fawzy Abou El Ezz ◽  
Nivine Gado ◽  
Amal Mahmoud Ibrahim Goda
Keyword(s):  
Breast Cancer ◽  
Quality Of Life ◽  
Family Income ◽  
Early Stage ◽  
Functional Domain ◽  
Related Factors ◽  
Specific Patient ◽  
Content Type ◽  
Factors Affecting

Purpose – The purpose of this paper is to measure health-related quality of life (QOL) among patients with early stage cancer breast under curative treatment at department of oncology and nuclear medicine at Ain Shams University Hospitals. Identify factors affecting QOL among these patients. Design/methodology/approach – A cross-sectional study measured QOL among early stage female breast cancer (BC) patients and determined the main factors affecting their QOL. Three interviewer administered questionnaires were used. Findings – The physical domain mostly affected in BC patients and the functional domain least. Socio-demographic factors that significantly affected BC patients QOL scores were patient age, education, having children and family income. Specific patient characteristics include caregiver presence – a factor that affected different QOL scores. Age at diagnosis, affection in the side of the predominant hand, post-operative chemotherapy and difficulty in obtaining the medication were the disease-related factors that affected QOL scores. Originality/value – The final model predicting QOL for early stage female BC patients included age, education and difficulty in obtaining the medication as determinants for total QOL score. Carer presence was the specific patient characteristic that affected different QOL scores.

The mechanism of process parameters influencing the AlSi10Mg side surface quality fabricated via laser powder bed fusion

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Shimin Dai ◽  
Hailong Liao ◽  
Haihong Zhu ◽  
Xiaoyan Zeng
Keyword(s):  
Surface Roughness ◽  
Surface Quality ◽  
Process Parameters ◽  
Laser Power ◽  
Side Surface ◽  
Laser Powder Bed Fusion ◽  
Scanning Velocity ◽  
Content Type ◽  
Powder Bed

Purpose For the laser powder bed fusion (L-PBF) technology, the side surface quality is essentially important for industrial applicated parts, such as the inner flow parts. Contour is generally adopted at the parts’ outline to enhance the side surface quality. However, the side surface roughness (Ra) is still larger than 10 microns even with contour in previous studies. The purpose of this paper is to study the influence of contour process parameters, laser power and scanning velocity on the side surface quality of the AlSi10Mg sample. Design/methodology/approach Using L-PBF technology to manufacture AlSi10Mg samples under different contour process parameters, use a laser confocal microscope to capture the surface information of the samples, and obtain the surface roughness Ra and the maximum surface height Rz of each sample after analysis and processing. Findings The results show that the side surface roughness decreases with the increase of the laser power at the fixed scanning velocity of 1,000 mm/s, the side surface roughness Ra stays within the error range as the contour velocity increases. It is found that the Ra increases with the scanning velocity increasing and the greater the laser power with the greater Ra increases when the laser power of contour process parameters is 300 W, 350 W and 400 W. The Rz maintain growth with the contour scanning velocity increasing at constant laser power. The continuous uniform contour covers the pores in the molten pool of the sample edge and thus increase the density of the sample. Two mechanisms named “Active adhesion” and “Passive adhesion” cause sticky powder. Originality/value Formation of a uniform and even contour track is key to obtain the good side surface quality. The side surface quality is determined by the uniformity and stability of the contour track when the layer thickness is fixed. These research results can provide helpful guidance to improve the surface quality of L-PBF manufactured parts.

scholarly journals Improving the quality of biopolymer (poly lactic acid) with the addition of bentonite as filler

2017 ◽  
Vol 222 ◽  
pp. 012008 ◽  
Author(s):  
Suryani ◽  
Harry Agusnar ◽  
Basuki Wirjosentono ◽  
Teuku Rihayat ◽  
Nurhanifa
Keyword(s):  
Lactic Acid ◽  
Poly Lactic Acid

Factors affecting the development of e-government using a citizen-centric approach

2015 ◽  
Vol 6 (3) ◽  
pp. 206-222 ◽  
Author(s):  
Kanda Sorn-in ◽  
Kulthida Tuamsuk ◽  
Wasu Chaopanon
Keyword(s):  
Quantitative Research ◽  
Service Providers ◽  
Structured Interview ◽  
Government Agencies ◽  
Content Type ◽  
Factors Affecting ◽  
Government Services ◽  
Government Sector ◽  
The Government

Purpose – The purpose of this paper is to study the factors affecting the development of e-government by using a citizen-centric approach. Design/methodology/approach – This paper is a mixed-methods study consisting of qualitative and quantitative research. Data were collected from government agencies using a structured interview and questionnaire about e-government services. The research was collected from the people responsible for the management of an e-government project in 75 government agencies. In addition, the researcher collected data from 1,400 citizens by using an e-Survey questionnaire that grouped participants by age. Findings – By using a citizen-centric approach, the paper identified the factors affecting the development of e-government. There were five factors from the viewpoint of government agencies and citizen groups: quality of e-government services, policy and governance, information technology infrastructure, organization and economy and society. Research limitations/implications – The research covered the development patterns of e-government for services from government to citizens only. Practical implications – Seeing the importance of environmental factors for both service providers and service users would facilitate continuous improvement of e-government service provision by government agencies. Social implications – The results reflect citizens’ need for e-government services; quality is their priority. Hence, government agencies must consider the quality of the delivery of information and e-government services as they relate to the lifestyles and needs of citizens. Originality/value – The creation of knowledge from merging e-government concepts with citizen-centric principles is a modern government sector management theory. This research stresses the need for the government sector to see the need for e-government and to recognize the factors for its successful development. This means the design and development of e-government services should respond to the increasing needs of the citizens.

Large-Diameter Line Pipe Expanding Process

2012 ◽  
Vol 192 ◽  
pp. 180-184 ◽  
Author(s):  
Ai Xia He ◽  
Rong Chang Li
Keyword(s):  
Process Parameters ◽  
Large Diameter ◽  
Dimensional Accuracy ◽  
Optimization Method ◽  
Main Process ◽  
Shape Accuracy ◽  
Line Pipe ◽  
Factors Affecting ◽  
Array Optimization

Mechanical expanding process for large diameter line pipe, a detailed analysis of factors affecting the quality of the final products of the mechanical expansion and proposed optimization using orthogonal array optimization method, as an indicator of dimensional accuracy and shape accuracy of the products, combination of a variety of specifications of mechanical expanding products, the main process parameters to be optimized. Analysis and discussion of results, revealing the degree of influence of various factors on the quality of the final product, and gives the optimum combination of the results. Experiments show that the combination of optimized process parameters, and more help to improve the accuracy of the size and shape of products.

Modeling and predicting the tensile strength of poly (lactic acid)/graphene nanocomposites by using support vector regression

2016 ◽  
Vol 30 (10) ◽  
pp. 1650052
Author(s):  
W. D. Cheng ◽  
C. Z. Cai ◽  
Y. Luo ◽  
Y. H. Li ◽  
C. J. Zhao
Keyword(s):  
Tensile Strength ◽  
Lactic Acid ◽  
Support Vector Regression ◽  
Process Parameters ◽  
Poly Lactic Acid ◽  
Percentage Error ◽  
Support Vector ◽  
Graphene Nanocomposites ◽  
Absolute Percentage Error ◽  
Rsm Model

According to an experimental dataset under different process parameters, support vector regression (SVR) combined with particle swarm optimization (PSO) for its parameter optimization was employed to establish a mathematical model for prediction of the tensile strength of poly (lactic acid) (PLA)/graphene nanocomposites. Four variables, while graphene loading, temperature, time and speed, were employed as input variables, while tensile strength acted as output variable. Using leave-one-out cross validation test of 30 samples, the maximum absolute percentage error does not exceed 1.5%, the mean absolute percentage error (MAPE) is only 0.295% and the correlation coefficient [Formula: see text] is as high as 0.99. Compared with the results of response surface methodology (RSM) model, it is shown that the estimated errors by SVR are smaller than those achieved by RSM. It revealed that the generalization ability of SVR is superior to that of RSM model. Meanwhile, multifactor analysis is adopted for investigation on significances of each experimental factor and their influences on the tensile strength of PLA/graphene nanocomposites. This study suggests that the SVR model can provide important theoretical and practical guide to design the experiment, and control the intensity of the tensile strength of PLA/graphene nanocomposites via rational process parameters.

Assessing residents’ perceptions of urban placemaking prior to hosting a major cultural event

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nicholas Wise ◽  
Jelena Đurkin Badurina ◽  
Marko Perić
Keyword(s):  
Quality Of Life ◽  
Design Methodology ◽  
Large Scale ◽  
Age Groups ◽  
Content Type ◽  
Factors Affecting ◽  
Local Quality ◽  
Practical Implications ◽  
Level Of Agreement

PurposeMore research is needed to consider residents’ perceptions prior to hosting large-scale events. This paper contributes new insight on residents’ perceptions of placemaking analysed by considering awareness, enthusiasm and participation prior to hosting a large-scale event. Placemaking is becoming increasingly important and this insight can help planners understand how locals perceive change and event planning preparations.Design/methodology/approach454 residents of Rijeka, Croatia completed a survey (seven-point Likert scale) of 17 placemaking principles, asked in three ways: (1) how you feel; (2) how you believe people near you feel and (3) if you feel that planning/preparing for ECoC 2020 has made a difference. The data analysis considers socio-demographics and the significance of awareness, enthusiasm and participation as factors affecting residents’ perceptions of placemaking.FindingsThe study found respondents originally from Rijeka expressed statistically significant higher level of agreement. Where statistically significant differences exist, female respondents expressed statistically significant higher levels of agreement. For six statements, the distribution of results was not similar for all age groups. Awareness and enthusiasm seems to influence placemaking principles to a greater extent than participation in this study, but all have proven to have statistically significant positive impacts on the placemaking principles assessed.Practical implicationsPlanners need to focus on effective promotional activities aimed at awareness and enhance enthusiasm to help increase perceptions of placemaking and increase local quality of life.Originality/valueexplores perceptions of “self” and “how others feel” by assessing principles of placemaking associated with the case of Rijeka. This allows researchers to explore understandings of how people perceive the attitudes of their fellow residents.

Factors Affecting the Size and Uniformity of Hollow Poly(lactic acid) Microcapsules Fabricated from Microbubble Templates

2011 ◽  
Vol 115 (47) ◽  
pp. 13828-13834 ◽  
Author(s):  
Jay Jesus Molino Cornejo ◽  
Hirofumi Daiguji ◽  
Fumio Takemura
Keyword(s):  
Lactic Acid ◽  
Poly Lactic Acid ◽  
Factors Affecting

Freedom and control: a state of balance in public space

Facilities ◽  
2014 ◽  
Vol 32 (11/12) ◽  
pp. 606-623 ◽  
Author(s):  
Tianjiao Zhao ◽  
Kin Wai Michael Siu
Keyword(s):  
Public Space ◽  
Urban Space ◽  
Open Space ◽  
Policy Design ◽  
Urban Life ◽  
Systematic Analysis ◽  
Content Type ◽  
Factors Affecting ◽  
And Control

Purpose – The purpose of this study is to determine how to achieve a balance between freedom and control in public space. It analyses the relationship between freedom and control to identify phenomena and offer users and policymakers instructions for achieving that balance. Public space, including privately owned public space, is important to urban living. People have both the right to use public space and the responsibility to protect it. Both freedom and control should exist in public space in an appropriate combination. It is impossible and inappropriate for us to ask for absolute freedom or endure unreasonable control. Design/methodology/approach – A case study of Hong Kong’s Mass Transit Railway (MTR) reveals typical freedom/control relationships. Quantitative descriptions are given based on field observations. Findings – Freedom and control are primary factors affecting the quality of urban life and management of city space. They depend on and conflict with each other. The balance between freedom and control is a balance between diverse spaces. The “freedom space” belonging to both citizens and authorities determines whether freedom and control are balanced. Ethics and strategies constitute control. Only when each authority and user obtains a proper freedom space can freedom and control achieve balance in public space. Research limitations/implications – Freedom and control differ across cities because they are both affected by culture, history and tradition. As each city has its own characteristics, the freedom and control in each open space are distinctive. Balancing freedom and control requires an understanding of a city’s background and the era. While this paper does not attempt to achieve this understanding, further studies could devote more attention to dimensions of time and location. Practical implications – The findings provide recommendations for users, policymakers and construction and management companies that will allow the management of harmonious and high-quality open spaces. Social implications – Freedom and control are two main factors affecting quality of life. The balance between freedom and control may bring a harmony and stable society environment. It would benefit both the authority and the people a lot. Originality/value – This study provides a systematic analysis of freedom and control in public space and makes a valuable contribution to quality urban space policy, design and management.

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