scholarly journals On the use of paper to facilitate recyclability of suspension packaging

2021 ◽  
Vol 3 (11) ◽  
Author(s):  
W. Nica ◽  
J. Roman ◽  
P. Slaets ◽  
M. Juwet
Keyword(s):  
Sample Preparation ◽  
Tensile Stress ◽  
Sample Size ◽  
Experimental Research ◽  
Experimental Methods ◽  
Ultimate Tensile Stress ◽  
Primary Objective ◽  
International Standards ◽  
Displacement Control ◽  
Recycled Fibers

AbstractBackground of this research is suspension packaging: fragile goods are attached to a panel of cardboard by wrapping it in stretch film. The panel is then appropriately folded, and the whole thing is placed in a cardboard box of corresponding dimensions. The primary objective of this study is to identify paper types that might be used in future as a more sustainable alternative for stretch wrap film. The experimental methods that are utilized are basically variants of mechanical pulling tests on paper samples. Sample preparation and sample size are adopted from international standards, but displacement control is adopted to detect relevant stretchability properties. Some kraft papers show a high ultimate tensile stress and a moderate stretchability, mainly permanent stretch as expected. Although the ultimate tensile stress of paper from recycled fibers is lower, some of these paper grades show a considerable higher stretchability including a higher elastic stretch. It is concluded that both kraft paper and paper grades from recycled fibers may be applicable as a wrapping material for suspension packaging. Further experimental research is needed to identify appropriate wrapping parameters for each paper type.

scholarly journals Experimental Methods for Measuring the Viscous Friction Coefficient in Hydraulic Spool Valves

2021 ◽  
Vol 13 (13) ◽  
pp. 7174
Author(s):  
Massimo Rundo ◽  
Paolo Casoli ◽  
Antonio Lettini
Keyword(s):  
Friction Coefficient ◽  
Viscous Friction ◽  
Experimental Tests ◽  
Experimental Methods ◽  
Displacement Transducer ◽  
A Posteriori ◽  
Displacement Control ◽  
Spool Valves ◽  
The University ◽  
Good Agreement

In hydraulic components, nonlinearities are responsible for critical behaviors that make it difficult to realize a reliable mathematical model for numerical simulation. With particular reference to hydraulic spool valves, the viscous friction coefficient between the sliding and the fixed body is an unknown parameter that is normally set a posteriori in order to obtain a good agreement with the experimental data. In this paper, two different methodologies to characterize experimentally the viscous friction coefficient in a hydraulic component with spool are presented. The two approaches are significantly different and are both based on experimental tests; they were developed in two distinct laboratories in different periods of time and applied to the same flow compensator of a pump displacement control. One of the procedures was carried out at the Fluid Power Research Laboratory of the Politecnico di Torino, while the other approach was developed at the University of Parma. Both the proposed methods reached similar outcomes; moreover, neither method requires the installation of a spool displacement transducer that can significantly affect the results.

Accessibility, Mobility and Spatial Patterns of Primary Health Care use in Ajedabiya: a Household Interview Survey

2010 ◽  
Vol 41 ◽  
pp. 47-62
Author(s):  
Salem F. Salem
Keyword(s):  
Health Care ◽  
Primary Health Care ◽  
Service Use ◽  
Primary Objective ◽  
Health Care Use ◽  
International Standards ◽  
Consultation Rate ◽  
General Evaluation ◽  
Primary Health ◽  
Time Required

AbstractThe primary objective of this study is to examine the type of Primary Health Care (PHC) facility used by a sample of households in Ajedabiya, taking into account the respondents' living standards and their perception of the quality of the care provided, as well as the mode of travel and travel time required to reach the health care centres. The overall level of service use has been increasing over time, reaching an annual consultation rate of up to four visits per person per year, a high level by international standards. Three major groupings of disease were identified for which the four selected PHC facilities were preferred. Satisfaction with care was analysed by looking at key variables, including staff behaviour, availability of doctors, vector distance to the PHC facility, general evaluation of health services and qualified doctors. Household incomes did not appear to be an important factor except for attending private clinics. Unlike income, distance had a strong effect on utilisation, leading to the conclusion that PHC should continue to be provided within the community, and developed further to achieve equity, effectiveness and affordability.

Investigation of Functionally Graded Aluminium A356 Alloy and A356-10%SiCp Composite for Hydro Turbine Bucket Application

2016 ◽  
Vol 26 ◽  
pp. 30-46 ◽  
Author(s):  
Williams S. Ebhota ◽  
Akhil S. Karun ◽  
Freddie L. Inambao
Keyword(s):  
Heat Treatment ◽  
Tensile Stress ◽  
Centrifugal Casting ◽  
A356 Alloy ◽  
Casting Process ◽  
Ultimate Tensile Stress ◽  
Functionally Graded ◽  
Cnc Machining ◽  
Mould Material ◽  
Turbine Bucket

The study investigates the application of centrifugal casting process in the production of a complex shape component, Pelton turbine bucket. The bucket materials examined were functionally graded aluminium A356 alloy and A356-10%SiCp composite. A permanent mould for the casting of the bucket was designed with a Solidworks software and fabricated by the combination of CNC machining and welding. Oil hardening non-shrinking die steel (OHNS) was chosen for the mould material. The OHNS was heat treated and a hardness of 432 BHN was obtained. The mould was put into use, the buckets of A356 Alloy and A356-10%SiCp composite were cast, cut and machined into specimens. Some of the specimens were given T6 heat treatment and the specimens were prepared according to the designed investigations. The micrographs of A356-10%SiCp composite shows more concentration of SiCp particles at the inner periphery of the bucket. The maximum hardness of As-Cast A356 and A356-10%SiCp composite were 60 BRN and 95BRN respectively, recorded at the inner periphery of the bucket. And these values appreciated to 98BRN and 122BRN for A356 alloy and A356-10%SiCp composite respectively after heat treatment. The prediction curves of the ultimate tensile stress and yield tensile stress show the same trend as the hardness curves.

Effect of Polyvinyl Alcohol Concentration on the Mechanical Properties of Collagen/Polyvinyl Alcohol Blends

2015 ◽  
Vol 732 ◽  
pp. 161-164 ◽  
Author(s):  
Jan Vesely ◽  
Lukas Horny ◽  
Hynek Chlup ◽  
Milos Beran ◽  
Milan Krajicek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Stress ◽  
Polyvinyl Alcohol ◽  
Modulus Of Elasticity ◽  
Tensile Tests ◽  
Ultimate Tensile Stress ◽  
Alcohol Concentration ◽  
Uniaxial Tensile ◽  
Initial Modulus ◽  
Water Saturated

The effects of the polyvinyl alcohol (PVA) concentration on mechanical properties of hydrogels based on blends of native or denatured collagen / PVA were examined. Blends of PVA with collagen were obtained by mixing the solutions in different ratios, using glycerol as a plasticizer. The solutions were cast on polystyrene plates and the solvent was allowed to evaporate at room temperature. Uniaxial tensile tests were performed in order to obtain the initial modulus of elasticity (up to deformation 0.1), the ultimate tensile stress and the deformation at failure of the material in the water-saturated hydrogel form. It was found that the material was elastic and the addition of PVA helped to enhance both the ultimate tensile stress and modulus of elasticity of the films. Samples prepared from denaturated collagen showed the higher ultimate tensile stress and the deformation at failure in comparison with those prepared from native collagen. The results suggest that we could expect successful application of the collagen/PVA biomaterial for tissue engineering.

scholarly journals The Effectiveness Of High Levels Of Knowledge Regarding Hiv/Aids In Reducing Discriminatory Attitudes And Behaviour Towards Hiv-Infected People

2006 ◽  
Vol 4 (1) ◽  
Author(s):  
M. Pirie ◽  
W. J. Coetsee
Keyword(s):  
Sample Size ◽  
Primary Objective ◽  
Large Sample Size ◽  
Infected People ◽  
Eta Squared ◽  
Secondary Objective ◽  
Level Of Knowledge ◽  
The Difference ◽  
F Statistics ◽  
Hiv Aids

The primary objective of this study was to assess whether there is a relationship between increasing levels of knowledge about HIV/AIDS and perceptions of discriminatory attitudes and behaviour towards people with HIV/AIDS. Employees (3662) from a large accounting firm were exposed to a survey and a response rate of 41% or 1532 was received. The secondary objective of the study was to determine whether there were any statistically significant differences in the mean difference of knowledge scores of groups created in terms of the different biographical variables. ANOVA’S (to determine the significance of differences between the means), t-tests (two groups only) and F-statistics were used for the analysis. Given the large sample size an F-test is not conclusive and the effect of the difference in sample size needs to be taken into account. For this reason it was also necessary to look at the Partial Eta Squared. Results indicate that respondents are generally knowledgeable about the prevention and transmission of HIV/AIDS and that respondents’ level of knowledge correlates negatively with discriminatory practices.

scholarly journals PENGGUNAAN METODE EKSPERIMEN PADA PEMBELAJARAN MATERI SIFAT BAHAN DAN KEGUNAANNYA TERHADAP HASIL DAN RESPON BELAJAR SISWA KELAS IV MIN TUNGKOB ACEH BESAR

2013 ◽  
Vol 13 (2) ◽  
Author(s):  
Wati Oviana ◽  
Maulidar Maulidar
Keyword(s):  
Experimental Study ◽  
Data Collection ◽  
Experimental Method ◽  
Learning Outcomes ◽  
Experimental Research ◽  
Experimental Methods ◽  
Learning Material ◽  
Primary School Students ◽  
School Students ◽  
Material Characteristics

The research on the use of experimental methods in learning characteristics of material and its usefulness toward students’ achievements and learning responses of Level 4 primary school students of MIN Tungkob Aceh Besar aims to determine students’ learning outcomes and responses toward the use of the method. This study uses experimental research. The data collection techniques were using test and distributing questionnaire to the students. The samples in this experimental study were students of class IV3 totaling 34 people as the experimental class and the class IV4 totaling 31 people as the control class. The data, which is the students’ learning outcomes collected from pretest and posttest, were analyzed using t-test formula. The data from the students’ questionnaire responses were analyzed using percentage formula.The result was that the students’ learning outcomes from the experimental class and the control class showed significant differences. Students’ responses toward the use of experimental methods in learning material characteristics and its usefulness were also very positive, where the students are very excited and interested in learning to use the experimental method in the study of material characteristics and its usefulness.

Physicomechanical properties of composites based on various types of polyethylene and aluminum

2020 ◽  
Vol 10 ◽  
pp. 48-55
Author(s):  
H. V. Allakhverdiyeva ◽  
◽  
N. T. Kakhramanov ◽  
I. I. Ismayilov ◽  
◽  
...  
Keyword(s):  
Tensile Stress ◽  
High Density Polyethylene ◽  
Ultimate Tensile Stress ◽  
High Density ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Aluminum Particles ◽  
Elongation At Break ◽  
Elastic Module ◽  
Properties Of Composites

The paper presents the results of a study of the effect of aluminum content on the physic-mechanical properties of composites based on high density polyethylene and low density polyethylene. The properties of metal-filled composites, such as ultimate tensile stress, elongation at break, elastic module, melt flow rate, and heat resistance, were studied. According to the data obtained, the loading of aluminum into the composition of low density polyethylene contributes to a monotonic increase in the ultimate tensile stress and the elastic module. When aluminum is loading into the composition of high density polyethylene, on the contrary, a natural decrease in the ultimate tensile stress and elongation at break of the composites is observed. It is shown that when using a compatibilizer, which is polyethylene modified with maleic anhydride, a significant increase in the ultimate tensile stress of high-density polyethylene composites is observed. A schematic representation of the structure of composites with an interpretation of the probable mechanism of hardening of the material in the presence of a compatibilizer is given. It is shown that the crystallinity of the initial polyethylene has a significant effect on the hardening effect of composites. Electron microscopic micrographs of the structure of a filled composite without and with compatibilizer are given. A comparative assessment shows that in the presence of a compatibilizer, aluminum particles are in the bulk of the polymer matrix, i.e. are not in an isolated state. It is assumed that HDPE macrochains free of maleic anhydride (MA) are involved in the formation of crystalline formations, and small sections of macrosegments containing polar groups of MA are concentrated mainly in amorphous regions and in defects in crystalline structures in the form of passage chains. The concentration of PEMA macrosegments containing MA in the narrow amorphous space of HDPE favorably affects the increase in the adhesive forces of interaction on the surface of aluminum particles, which affects the preservation of the ultimate tensile stress at a relatively high level over a wide range of aluminum concentrations.

Evaluation of Current AOAC Fertilizer Sample Preparation Requirements

1993 ◽  
Vol 76 (6) ◽  
pp. 1174-1181
Author(s):  
Natalie Newlon ◽  
Candace Cox-Trout ◽  
Peter Kane
Keyword(s):  
Particle Size ◽  
Sample Preparation ◽  
Sample Size ◽  
Wide Distribution ◽  
Ground Sample ◽  
Fertilizer Sample ◽  
Sample Portion ◽  
Current Sample ◽  
The Relationship ◽  
Better Than

Abstract The official AOAC fertilizer sample preparation requires that all dry mixtures be ground to pass a U.S. No. 40 sieve. With current fertilizers and mechanical grinders, these criteria may no longer be appropriate. Blended fertilizers were ground and sieved, and the fractions were analyzed separately to show potential variability in results. In general, potassium was heavily concentrated in the smaller particles of the ground sample, whereas phosphorus tended to be concentrated in the coarser particles. A representative set of fertilizers was subjected to 7 grinding treatments designed to produce samples with a wide distribution of particle size. N, P, and K were determined in the samples by traditional methods. Analysis of the results demonstrated that precise, accurate results could be obtained from samples that did not technically meet current sample preparation requirements. The relationship between fineness of grind and size of the analytical sample portion was examined. With proper sample grinding, sample sizes of ≤20 mg could give representative results for nitrogen analysis, with precision equal to or better than traditional Kjeldahl analysis using 1 g samples. This is of particular interest, because various combustion instruments now becoming popular for nitrogen analysis are limited in sample size.

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