The Analysis of Key Influence Factors and Application Countermeasures on Quality of FDM Prototype Model

2010 ◽  
Vol 136 ◽  
pp. 122-125
Author(s):  
Qing Quan Hou ◽  
Can Zhao

This paper presents a study on the machining quality of prototype model, and points out its important influencing factors including shaping room temperature, shrinkage ratio of material and wet condition of support material and so on. The prototype model was processed by FDM 3000 rapid prototyping machine made by Stratasys, Inc. There are some concrete problems including inappropriate placement orientation, oversize of prototype, and high efficiency of multi-parts manufacture in practice. At the same time, practical methods were given.

2014 ◽  
Vol 496-500 ◽  
pp. 1235-1239
Author(s):  
Hong Liu ◽  
Yong Zhang ◽  
Li Li Luo

It is an important factor that tool size affects the quality and efficiency of complex curved surface of CNC machining. This paper starts with analyzing the functional relationship between the tool size and the quality and efficiency of complex curved surface, gives the selection method of optimal minimum tool which can ensure the precision of machining curved surface, establishes optimal selecting algorithm of reasonable large size tool with the most high efficiency as the objective, and for the curved surface of complex geometric features, puts forward tool combination selection method with effective area ratio of tool machining as a reference. Application examples show: the optimal selecting strategy of tool size in this paper, under the premise of adequately ensuring the machining quality of complex curved surface, can effectively improve the whole machining efficiency.


2010 ◽  
Vol 458 ◽  
pp. 48-54 ◽  
Author(s):  
T.J. Wu ◽  
Pei Huang Lou ◽  
Z.G. Man

Fixtures are used to locate and constrain firmly a workpiece during machining operation. Flexible and efficient fixturing has become an important issue in flexible manufacturing systems and computer integrated manufacturing system. Locating planning is the basis of the fixturing design, which has a direct influence on the quality of the clamping scheme and the machining quality of workpiece. This paper presents a new approach for locating planning of workpiece. Firstly, it will automatically select the primary locating surfaces with consideration of 5 influence factors: constraint freedoms, surface feature, valid locating area, tolerance relationship and surface roughness. Then the other locating surfaces are determined by retrieving similar workpieces under the guideline of 4 locating methods which will make the best of already available locating planning. Finally the optimal locator layout is fast achieved with GA with the goal of minimal locating tolerance.


2021 ◽  
Vol 100 ◽  
pp. 01022
Author(s):  
Oksana Yelisyeyeva ◽  
Nadiia Shmygol ◽  
Nataliia Kutova ◽  
Iryna Stolietova ◽  
Jan Polcyn

It is justified the use of a generic integral indicator and its graphical interpretation for the enterprise staff incentives system establishing, which makes it possible to determine the influence of group indicators as well as to establish the functional links between indicators. The integral index of personnel incentives efficiency and influence factors are determined. The most important quantitative factors that affect the high efficiency of staff incentives are defined. The relevance between the results of enterprises and indicators of the effectiveness of staff incentives is determined. The educational and professional quality of the staff is determined by means of a score. The employee motivational profile diagram is constructed. The staff assessment system has been developed to improve staff skills. The based on a competent and attributive approach review of grades and categories for staff is proposed.


2019 ◽  
Author(s):  
Shuyuan Zheng ◽  
Taiping Hu ◽  
Xin Bin ◽  
Yunzhong Wang ◽  
Yuanping Yi ◽  
...  

Pure organic room temperature phosphorescence (RTP) and luminescence from nonconventional luminophores have gained increasing attention. However, it remains challenging to achieve efficient RTP from unorthodox luminophores, on account of the unsophisticated understanding of the emission mechanism. Here we propose a strategy to realize efficient RTP in nonconventional luminophores through incorporation of lone pairs together with clustering and effective electronic interactions. The former promotes spin-orbit coupling and boost the consequent intersystem crossing, whereas the latter narrows energy gaps and stabilizes the triplets, thus synergistically affording remarkable RTP. Experimental and theoretical results of urea and its derivatives verify the design rationale. Remarkably, RTP from thiourea solids with unprecedentedly high efficiency of up to 24.5% is obtained. Further control experiments testify the crucial role of through-space delocalization on the emission. These results would spur the future fabrication of nonconventional phosphors, and moreover should advance understanding of the underlying emission mechanism.<br>


Author(s):  
Nguyễn Thị Hồng Thu ◽  
Đặng Minh Nhật ◽  
Nguyễn Hoàng Dung

Sugar palm (Arenga pinnata) is a feather palm native to tropical Asia. In Vietnam, it is named Búng Báng or Đoác and grown only on the highlands in the central or northern part of Vietnam. It is utilized for many purposes, especially for Ta Vat wine production - a characteristic and unique product of Co Tu ethnic minority. However, because of the natural fermentation used in the production, the product quality is inconsistent. The purpose of this study was to examine a new procedure of using palm sap for making Ta Vat wine. Some characteristics of the sap, which was collected at Nam Giang district, Quang Nam province are determined, proving the potential of the sap for making wine product. The quality of sap changes quickly at room temperature. At low temperature (4 - 60C), the changes in sap quality are apparently slower. Examining some factors affecting its quality during the wine fermentation process, we determined the best parameters for the fermentation process as follows: inoculum size of 3% with cell density of about 1x108 cells/ml, the addition of the extract from the bark of Ceylon ironwood (Mesua ferrea L.) 4%. Keywords: Arenga pinnata, sap, Ceylon ironwood bark, Mesua ferrea L., wine fermentation.


2021 ◽  
Vol 11 (4) ◽  
pp. 1748
Author(s):  
Giovanna Concu

Timber buildings are experiencing a rapid diffusion due to their good performance and their sustainability; however, some steps of structural timber production process, such as drying, are energy-intensive and environmentally impactful, and many wood species are also affected by low yield. Therefore, it would be important to determine the quality of the green material, that is, in wet condition, before undergoing the most impactful and expensive production steps. This paper describes a research aimed at quantifying the variation of the dynamic modulus of elasticity MoEdyn, which is commonly used for structural timber mechanical grading, from wet to dry condition in Sardinian maritime pine boards to be used for the production of laminated timber, and to examine the relationship between wet and dry MoEdyn. The MoEdyn was determined from measurements of the velocity of sonic waves propagating through the boards. The results show that the dry MoEdyn can be estimated starting from boards sonic testing in the wet condition, so providing a basis for implementing Sardinian maritime pine pre-grading in order to obtain the reduction of manufacturing costs, the abatement of environmental impact, and the increase of structural grade yield.


Transfusion ◽  
2021 ◽  
Vol 61 (S1) ◽  
Author(s):  
Turid Helen Felli Lunde ◽  
Lindsay Hartson ◽  
Shawn Lawrence Bailey ◽  
Tor Audun Hervig
Keyword(s):  

2011 ◽  
Vol 78 (4) ◽  
pp. 385-390 ◽  
Author(s):  
Priscilla A Melville ◽  
Nilson R Benites ◽  
Monica Ruz-Peres ◽  
Eugenio Yokoya

The presence of yeasts in milk may cause physical and chemical changes limiting the durability and compromising the quality of the product. Moreover, milk and dairy products contaminated by yeasts may be a potential means of transmission of these microorganisms to man and animals causing several kinds of infections. This study aimed to determine whether different species of yeasts isolated from bovine raw milk had the ability to develop at 37°C and/or under refrigeration temperature. Proteinase and phospholipase activities resulting from these yeasts were also monitored at different temperatures. Five genera of yeasts (Aureobasidium sp., Candida spp., Geotrichum spp., Trichosporon spp. and Rhodotorula spp.) isolated from bovine raw milk samples were evaluated. All strains showed one or a combination of characteristics: growth at 37°C (99·09% of the strains), psychrotrophic behaviour (50·9%), proteinase production (16·81% of the strains at 37°C and 4·09% under refrigeration) and phospholipase production (36·36% of the isolates at 37°C and 10·9% under refrigeration), and all these factors may compromise the quality of the product. Proteinase production was similar for strains incubated at 37°C (16·81% of the isolates) and room temperature (17·27%) but there was less amount of phospholipase-producing strains at room temperature (15·45% of the isolates were positive) when compared with incubation at 37°C (36·36%). Enzymes production at 37°C by yeasts isolated from milk confirmed their pathogenic potential. The refrigeration temperature was found to be most efficient to inhibit enzymes production and consequently ensure better quality of milk. The viability of yeasts and the activity of their enzymes at different temperatures are worrying because this can compromise the quality of dairy products at all stages of production and/or storage, and represent a risk to the consumer.


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