scholarly journals Implementation of a remote laboratory for the identification of polymeric materials by means of physical properties analysis

2021 ◽  
Vol 2102 (1) ◽  
pp. 012008
Author(s):  
C O Vargas-Mantilla ◽  
W Palacios-Alvarado ◽  
B Medina-Delgado
Keyword(s):  
Physical Properties ◽  
Engineering Students ◽  
Chemical Properties ◽  
Polymeric Materials ◽  
Experimental Tests ◽  
Nonparametric Tests ◽  
Point Of View ◽  
Remote Laboratory ◽  
Physical And Chemical ◽  
And Chemical Properties

Abstract Due to the strategies implemented to carry out the development of a correct teaching by virtual means, a methodological strategy of experimental tests was developed for the identification of polymeric materials through the identification of physical and chemical properties, with the objective of providing the engineering student a greater approach to the application of the scientific method and the activation of the capacity of reasoning and deductive thinking from the physical and chemical point of view. Therefore, the purpose of this research was to validate this strategy implemented with a group of engineering students, for this purpose, the strategy was implemented, and the results obtained by the students from the development of the experimentation were analyzed, the data were analyzed by means of nonparametric tests, in this case binomial test. Finally, it is concluded that the polymer identification test is feasible to be implemented as a remote laboratory, as a methodical strategy in teaching, since it allows the development of experimentation, in this case, the identification of polymeric materials, which present diverse physical properties.

scholarly journals Chemical and Physical Properties of Some Hazelnut Varieties Grown in Portugal

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1476
Author(s):  
Ana Cristina Ferrão ◽  
Raquel P. F. Guiné ◽  
Elsa Ramalhosa ◽  
Arminda Lopes ◽  
Cláudia Rodrigues ◽  
...  
Keyword(s):  
Discriminant Analysis ◽  
Physical Properties ◽  
Water Activity ◽  
Induction Time ◽  
Oxidation Stability ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Nutritional Characteristics ◽  
Physical And Chemical ◽  
And Chemical Properties

Hazelnuts are one of the most appreciated nuts worldwide due to their unique organoleptic and nutritional characteristics. The present work intended to analyse several physical and chemical properties of different hazelnut varieties grown in Portugal, namely Tonda de Giffoni, Grada de Viseu, Segorbe, Longa de Espanha, Butler, Gunslebert, and Negreta. In general, the results revealed statistically significant differences between the varieties under study. The Gunslebert had more elongated hazelnuts and with heavier shelled fruits, while the kernels of the Grada de Viseu revealed to be heavier. Grada de Viseu was harder in the shell, Gunslebert had a harder core, and Segorbe was more resistant to fracture. Fat was the more representative component for all varieties and in some cases the values of moisture and water activity were over the recommended amount (≥0.62). Tonda de Giffoni was the variety with the highest induction time, indicating the highest oxidation stability. Moreover, discriminant analysis revealed that the variables more important to distinguish the varieties were protein (λ = 0.007) and water activity (λ = 0.010). The results of this study help to better understand the differences between some hazelnut varieties that are cultivated in Portugal, which gives important hints for all players in the hazelnut sector.

scholarly journals Effect of Mosses on physical and chemical properties of soil in temperate forests of Garhwal Himalayas

2021 ◽  
pp. 1-10
Author(s):  
Anshu Siwach ◽  
Siddhartha Kaushal ◽  
Ratul Baishya
Keyword(s):  
Physical Properties ◽  
Chemical Properties ◽  
Nutrient Status ◽  
High Rate ◽  
Physical And Chemical Properties ◽  
Garhwal Himalayas ◽  
Forest Sites ◽  
Significant Difference ◽  
Physical And Chemical ◽  
And Chemical Properties

Abstract Mosses are one of the most important and dominant plant communities, especially in the temperate biome, and play a significant role in ecosystem function and dynamics. They influence the water, energy and element cycle due to their unique ecology and physiology. The present study was undertaken in three different temperate forest sites in the Garhwal Himalayas, viz., Triyuginarayan (Kedarnath Wildlife Sanctuary (KWLS)), Chakrata, and Kanasar forest range. The study was focused on understanding the influence of mosses on soil physical properties and nutrient availability. Different physico-chemical properties were analysed under two different substrata, that is, with and without moss cover in two different seasons, viz., monsoon and winter. We observed mosses to influence and alter the physical properties and nutrient status of soil in both seasons. All soil physical and chemical properties, except magnesium, showed significant difference within the substrates, among all the sites and across the two seasons. Besides the soil characteristics underneath the moss vegetation, the study also highlights the diversity of mosses found in the area. Mosses appear to create high nutrient microsites via a high rate of organic matter accumulation and retain nutrients for longer periods thus, maintaining ecosystem stability.

Study of Relative Metallic Character of Noble Metals Cu, Ag and Au at Normal Temperatures

2021 ◽  
Vol 1019 ◽  
pp. 174-178
Author(s):  
Ramesh Kumar ◽  
Priti Kumari ◽  
Kumar Saurav ◽  
Purushottam Poddar ◽  
Vijay Kumar Verma
Keyword(s):  
Physical Properties ◽  
Noble Metals ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Metallic Character ◽  
Physical And Chemical ◽  
And Chemical Properties

The relative metallic character of noble metals, Cu, Ag & Au has been suggested by their physical and chemical properties. Their position in the metallic series is in the neighborhood of that of Li, Mg and Zn. These Metals are inferior of Li, Mg, Zn, Fe, Co and Ni in metallic character. Li, Mg, Zn, Fe, Co and Ni are inferior to Na, K, Rb, Cs, Ca, Ba and Sr. The noble metals have simple metallic character in physical properties at normal temperatures.

Statistical Lengths of Rubberlike Hydrocarbon Molecules

1943 ◽  
Vol 16 (3) ◽  
pp. 479-485
Author(s):  
Frederick T. Wall
Keyword(s):  
Natural Rubber ◽  
Physical Properties ◽  
Chemical Properties ◽  
Hydrocarbon Chain ◽  
Point Of View ◽  
Double Bonds ◽  
Gutta Percha ◽  
Cis And Trans ◽  
Trans Structure ◽  
And Chemical Properties

Abstract It has been known for some time that the pure hydrocarbons of balata (or gutta-percha) and natural rubber have the same chemical composition and chemical properties. Both balata and rubber appear to be polymers of isoprene, (C5H8)n, with the same degree of unsaturation. Their physical properties are sufficiently different, however, to make it clear that their structures must differ in some important respect. Since the molecules contain numerous double bonds, it has been suggested that rubber and balata are geometric isomers. Every fourth bond in a rubber or balata molecule is a double bond, so it follows that the possibilities for geometric isomerism are considerable. It was proposed by Meyer and Mark that natural rubber hydrocarbon has a structure for which the molecular chain is cis with respect to all of the double bonds. Balata (or gutta-percha) is then supposed to have a trans-structure throughout, this view having been verified by Fuller and Bunn. It is the purpose of the present paper to consider, from the point of view of recent theories of rubber elasticity, to what extent these structures explain the differences in physical properties. The method to be employed involves calculation of the root mean square lengths of the cis- and trans-structures, which, when compared to their maximum lengths, should give an indication of their extensibilities. In 1932 Eyring treated the problem of the average square length of a hydrocarbon chain. In the present paper a different derivation of Eyring's equation is given (for illustrative purposes), after which this derivation will be extended to the rubberlike molecules with double bonds.

Corrigenda - The effects of minimum cultivation after three years on some physical and chemical properties of a red-brown earth at Forbes, NSW.

Soil Research ◽  
1991 ◽  
Vol 29 (2) ◽  
pp. 263 ◽  
Author(s):  
PP Cavanagh ◽  
AJ Koppi ◽  
AB Mcbratney
Keyword(s):  
Organic Carbon ◽  
Physical Properties ◽  
Bulk Density ◽  
Total Nitrogen ◽  
Chemical Properties ◽  
Water Infiltration ◽  
Electrolytic Conductivity ◽  
Physical And Chemical Properties ◽  
Physical And Chemical ◽  
And Chemical Properties

Reducing cultivation may improve many soil physical and chemical properties of a red-brown earth. A trial was set up in 1986 on a red-brown earth near Forbes, N.S.W., comparing direct-drilling and conventional-cultivation crop establishment techniques. The surface soil (0-100 mm) was sampled at the end of the third year and assessed for macropore structure, infiltration characteristics, bulk density, pH, electrolytic conductivity, organic carbon and total nitrogen content. Cultivation degraded some desirable soil physical properties as indicated by data obtained from image analysis and infiltration. Bulk density did not mirror differences in macroporosity. Organic carbon, total nitrogen and electrolytic conductivity levels were higher in direct-drilled soil in comparison to conventionally tilled soil. It ib concluded that the improvement of soil chemical and physical properties afforded by a reduction in tillage would lead to an increase in soil water infiltration rate and storage.

The effects of minimum cultivation after three years on some physical and chemical properties of a red-brown earth at Forbes, NSW.

Soil Research ◽  
1991 ◽  
Vol 29 (2) ◽  
pp. 263
Author(s):  
PP Cavanagh ◽  
AJ Koppi ◽  
AB Mcbratney
Keyword(s):  
Organic Carbon ◽  
Physical Properties ◽  
Bulk Density ◽  
Total Nitrogen ◽  
Chemical Properties ◽  
Water Infiltration ◽  
Electrolytic Conductivity ◽  
Physical And Chemical Properties ◽  
Physical And Chemical ◽  
And Chemical Properties

Reducing cultivation may improve many soil physical and chemical properties of a red-brown earth. A trial was set up in 1986 on a red-brown earth near Forbes, N.S.W., comparing direct-drilling and conventional-cultivation crop establishment techniques. The surface soil (0-100 mm) was sampled at the end of the third year and assessed for macropore structure, infiltration characteristics, bulk density, pH, electrolytic conductivity, organic carbon and total nitrogen content. Cultivation degraded some desirable soil physical properties as indicated by data obtained from image analysis and infiltration. Bulk density did not mirror differences in macroporosity. Organic carbon, total nitrogen and electrolytic conductivity levels were higher in direct-drilled soil in comparison to conventionally tilled soil. It ib concluded that the improvement of soil chemical and physical properties afforded by a reduction in tillage would lead to an increase in soil water infiltration rate and storage.

Study of the Chemical and Physical Properties of the Fiber-Matrix Interface of Biocomposite Material Based on a Copolymer Matrix Polylactic Acid (PLA)

2019 ◽  
Vol 12 (1) ◽  
pp. 70-78
Author(s):  
Mokhtaria Ould Kada ◽  
Allel Mokaddem ◽  
Bendouma Doumi ◽  
Mohamed Berber ◽  
Lahouari Temimi ◽  
...  
Keyword(s):  
Physical Properties ◽  
Polylactic Acid ◽  
Probabilistic Approach ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Matrix Interface ◽  
Fiber Matrix Interface ◽  
Fiber Matrix ◽  
Physical And Chemical ◽  
And Chemical Properties

Background: In this paper, we have studied the improvement of the physical and chemical properties of the fiber-matrix interface of a Biocomposite based on the copolymer polylactic acid (PLA). Methodology: We have developed an analytical model using a genetic approach to locate the interface damage under the effect of mechanical stress, temperature and humidity. Our simulation is based on Weibull's probabilistic approach and the law of water diffusion in polymer matrix, the diffusion is generated by Fick's law. Results: Our results show that the interface of Biocomposite (Starch-PLA) is the most resistant to the different constraints applied and that the physical and chemical properties of this material are much more improved compared to other materials studied by the same genetic model. Conclusion: Our calculations coincide perfectly with the conclusions of Antoine et al. who determined that natural fibers improve the physical properties of composite materials.

The Compounding of Hard Rubber (Natural and Synthetic)

1950 ◽  
Vol 23 (1) ◽  
pp. 266-280 ◽  
Author(s):  
W. Murray Gall
Keyword(s):  
Physical Properties ◽  
Chemical Properties ◽  
High Grade ◽  
Physical And Chemical Properties ◽  
Similar Materials ◽  
Physical And Chemical ◽  
Plastics Industry ◽  
And Chemical Properties ◽  
Natural And Synthetic

Abstract Hard rubber, frequently called ebonite, is a material which has many desirable physical and chemical properties. The relatively new plastics industry has offered stiff competition, yet it is reasonably safe to say that, for certain applications, nothing else can be substituted for hard rubber and still maintain its unique properties. One of the principal qualities of this material is its finished appearance. When a high-grade ebonite compound is properly processed, it can be given a high lustrous finish which sets it apart from similar materials for beauty and richness. The highest grade of hard rubber is a compound containing only rubber and sulfur. It is in this type of compound that maximum physical properties and highest luster are found.

scholarly journals Comparative Study on Different Physical Properties of Grey & Finished Single Jersey Derivatives

2018 ◽  
Vol 5 (1) ◽  
pp. 6-10
Author(s):  
Suraiya Ireen ◽  
Md Mahbubur Rahman
Keyword(s):  
Physical Properties ◽  
Chemical Properties ◽  
Efficient Production ◽  
Science And Engineering ◽  
Knitted Fabrics ◽  
Finishing Process ◽  
Fabric Production ◽  
Physical And Chemical ◽  
Single Jersey ◽  
And Chemical Properties

Knitting is the mostly used fabric manufacturing processes in Bangladesh through which various types of knitted fabrics with different physical and chemical properties are produced. Single jersey derivatives have some dimensional, physical or chemical properties that change according to some factors and processing. These properties also change after dyeing & finishing process. As finishing is mandatory for fabric production, some tests are carried out after finishing stage & proper controlling is done according desired quality. Single jersey fabrics show low strength and higher abrasion resistance than grey fabric after dyeing & finishing. Finished fabric is more stiff than grey. Spirality & shrinkage properties of the single jersey fabric are rapidly change after dyeing & finishing and generally acceptable under the limit. Therefore, this paper is all about the comparison of physical properties among various grey and finished single jersey weft knitted fabrics which will be helpful to know for efficient production, taking corrective actions to minimize changes of basic physical properties and produce quality knit products. GUB JOURNAL OF SCIENCE AND ENGINEERING, Vol 5(1), Dec 2018 P 6-10

scholarly journals SOME TECHNICAL DIFFICULTIES AND WAYS OF THEIR OVERCOMING DURING VERTEBROPLASTY DEVELOPMENT

2010 ◽  
Vol 16 (1) ◽  
pp. 68-70
Author(s):  
D. S. Astapenkov
Keyword(s):  
Chemical Properties ◽  
Point Of View ◽  
Physical And Chemical Properties ◽  
Venous Outflow ◽  
Intravenous Anesthesia ◽  
Osteoporotic Vertebral Fractures ◽  
Vertebral Bodies ◽  
Metastatic Involvement ◽  
Physical And Chemical ◽  
And Chemical Properties

Vertebroplasty was performed in 8 women in the age of from 43 till 80 years. The indication to intervention in one case was metastatic involvement, in four cases - osteoporotic vertebral fractures; to three patients vertebroplasty was performed in occasion of vertebral body gemangioma. The results of this study revealed, that for increase of safety the authors recommend to carry out the vertebroplasty under local anesthesia at presence of an anesthesiologist for possible additional intravenous anesthesia. The safest from the point of view of extravertebral distributions of cement is transpedicular access; flebospondylography does not allow predicting reliably distribution of cement in view of significant distinction of physical and chemical properties of entered substances however can be used for a tentative estimation of venous outflow at tumor process in vertebral bodies.

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