scholarly journals Mechanical properties of Indonesian hyperelastic low-grade rubber for low-cost base isolator

2019 ◽  
Vol 276 ◽  
pp. 01017 ◽  
Author(s):  
Usman Wijaya ◽  
Roesdiman Soegiarso ◽  
Tavio
Keyword(s):  
Test Data ◽  
Base Isolation ◽  
Raw Materials ◽  
Low Grade ◽  
Tropical Country ◽  
Isolation System ◽  
Uniaxial Test ◽  
Earthquake Force ◽  
Best Fitting ◽  
The Impact

Most parts of Indonesia are located at high-risk seismic regions. Therefore, it is necessary to seriously consider earthquake in designing the seismic-resistant buildings. One of the most effective methods to reduce the impact of the earthquake force is to introduce the use of the elastomeric rubber base isolation as an effective earthquake damper. Indonesia as a tropical country has many sources of raw materials particularly rubber. This can be potential as a main basic need for producing an optimum elastomeric rubber base isolation system. This paper determined an approach method of constitutive low-grade rubber to get the best fitting with experimental data. Five deformation models such as Mooney-Rivlin, Ogden, Arruda-Boyce, Neo-Hookean, Yeoh models compare to uniaxial test were adopted to simulate the characteristics of rubber materials used in base isolation. From the analysis, it can be concluded that Yeoh model give the best fitting and the most accurate to the test data even in limited test data.

scholarly journals Impact of Sodium Hexametaphosphate on the Flotation of Ultrafine Magnesite from Dolomite-Rich Desliming Tailings

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 499
Author(s):  
Duong Huu Hoang ◽  
Doreen Ebert ◽  
Robert Möckel ◽  
Martin Rudolph
Keyword(s):  
Ultrafine Particles ◽  
Raw Materials ◽  
Low Cost ◽  
Froth Flotation ◽  
Open Circuit ◽  
Ore Deposits ◽  
Sodium Hexametaphosphate ◽  
Low Grade ◽  
Low Contrast ◽  
The Impact

The depletion of ore deposits, the increasing demand for raw materials, the need to process low-grade, complex and finely disseminated ores, and the reprocessing of tailings are challenges especially for froth flotation separation technologies. Even though they are capable of handling relatively fine grain sizes, the flotation separation of very fine and ultrafine particles faces many problems still. Further, the flotation of low-contrast semi-soluble salt-type minerals with very similar surface properties, many complex interactions between minerals, reagents and dissolved species often result in poor selectivity. This study investigates the flotation beneficiation of ultrafine magnesite rich in dolomite from desliming, currently reported to the tailings. The paper especially focuses on the impact of the depressant sodium hexametaphosphate (SHMP) on the following: (i) the froth properties using dynamic froth analysis (DFA), (ii) the separation between magnesite and dolomite/calcite, and (iii) its effect on the entrainment. As a depressant/dispersant, SHMP has a beneficial impact on the flotation separation between magnesite and dolomite. However, there is a trade-off between grade and recovery, and as well as the dewatering process which needs to be considered. When the SHMP increases from 200 g/t to 700 g/t, the magnesite grade increases from 67% to 77%, while recovery decreases massively, from 80% to 40%. The open circuit with four cleaning stages obtained a concentrate assaying 77.5% magnesite at a recovery of 45.5%. The dolomite content in the concentrate is about 20%, where 80% of dolomite was removed and importantly 98% of the quartz was removed, with only 0.3% of the quartz in the final concentrate. Furthermore, the application of 1-hydroxyethylene-1,1-diphosphonic acid (HEDP) as a more environmentally friendly and low-cost alternative to SHMP is presented and discussed. Using only 350 g/t of HEDP can achieve a similar grade (76.3%), like 700 g/t of SHMP (76.9%), while obtaining a 17% higher magnesite recovery as compared to 700 g/t of SHMP. Interestingly, the proportion of hydrophilic quartz minerals ending up in the concentrate is lower for HEDP, with only 1.9% quartz at a recovery of 21.5% compared to the 2.7% of quartz at a recovery of 24.9% when using SHMP. The paper contributes in general to understanding the complexity of the depressant responses in froth flotation.

scholarly journals On Characteristics of Ferritic Steel Determined during the Uniaxial Tensile Test

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3117
Author(s):  
Ihor Dzioba ◽  
Sebastian Lipiec ◽  
Robert Pala ◽  
Piotr Furmanczyk
Keyword(s):  
Tensile Test ◽  
Test Data ◽  
Constitutive Relationship ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Element Analysis ◽  
Material Weakness ◽  
Uniaxial Test ◽  
The Impact ◽  
Tensile Test Data

Tensile uniaxial test is typically used to determine the strength and plasticity of a material. Nominal (engineering) stress-strain relationship is suitable for determining properties when elastic strain dominates (e.g., yield strength, Young’s modulus). For loading conditions where plastic deformation is significant (in front of a crack tip or in a neck), the use of true stress and strain values and the relationship between them are required. Under these conditions, the dependence between the true values of stresses and strains should be treated as a characteristic—a constitutive relationship of the material. This article presents several methodologies to develop a constitutive relationship for S355 steel from tensile test data. The constitutive relationship developed was incorporated into a finite element analysis of the tension test and verified with the measured tensile test data. The method of the constitutive relationship defining takes into account the impact of high plastic strain, the triaxiality stress factor, Lode coefficient, and material weakness due to the formation of microvoids, which leads to obtained correctly results by FEM (finite elements method) calculation. The different variants of constitutive relationships were applied to the FEM loading simulation of the three-point bending SENB (single edge notched bend) specimen to evaluate their applicability to the calculation of mechanical fields in the presence of a crack.

Dynamic Buckling of 50000m3 Vertical Storage Tanks under Seismic Excitation

2013 ◽  
Vol 353-356 ◽  
pp. 2039-2042
Author(s):  
Sun Ying ◽  
Jian Gang Sun ◽  
Li Fu Cui
Keyword(s):  
Storage Tank ◽  
Numerical Solutions ◽  
Base Isolation ◽  
Three Dimensional ◽  
Dynamic Buckling ◽  
Seismic Excitation ◽  
Storage Tanks ◽  
Isolation System ◽  
Base Isolation System ◽  
The Impact

To study the dynamic buckling characteristics of storage tank subjected to three-dimensional seismic excitation, selecting 50000m3 large vertical floating roof storage tanks as research object, the base isolation system was introduced and allowing for the impact of floating roof. The finite element models of non-isolation and base isolation storage tank were established respectively by ADINA. The seismic responses of these two types of storage tank were calculated and the numerical solutions were compared. The results indicate that the dynamic buckling modes of these two types of storage tank system belong to plastic buckling; base isolation measure can effectively increase the critical load value of dynamic buckling and plasticity yielding, the improve rates up to 38% and 60% respectively. The effectiveness of the base isolation can be verified from the angle of buckling.

scholarly journals Impact of Sodium Hexametaphosphate on the Flotation of Ultrafine Magnesite from Dolomite-rich Desliming Tailings

2021 ◽  
Author(s):  
Duong Huu Hoang ◽  
Doreen Ebert ◽  
Robert Möckel ◽  
Martin Rudolph
Keyword(s):  
Ultrafine Particles ◽  
Raw Materials ◽  
Low Cost ◽  
Froth Flotation ◽  
Ore Deposits ◽  
Sodium Hexametaphosphate ◽  
Low Grade ◽  
Low Contrast ◽  
Fine Grain ◽  
The Impact

Depletion of ore deposits, increasing demand for raw materials, the need to process low-grade, complex and finely disseminated ores and the reprocessing of tailings are challenges, especially for froth flotation separation technologies. Even though capable of handling relatively fine grain sizes the flotation separation of very fine and ultrafine particles faces many problems still. Further, the flotation of low-contrast semi-soluble salt-type minerals with very similar surface properties, many complex interactions between minerals, reagents and dissolved species often result in poor selectivity. This study investigates the flotation beneficiation of ultrafine magnesite rich in dolomite from de-sliming, currently reported to the tailings. The paper especially focuses on the impact of the depressant sodium hexametaphosphate (SHMP) on: (i) the froth properties using dynamic froth analysis (DFA), (ii) the separation between magnesite and dolomite/calcite and (iii) its effect on the entrainment. Furthermore, the application of 1-hydroxyethylene-1,1-diphosphonic acid (HEDP) is a more environmentally friendly and low-cost alternative to SHMP is presented and discussed. The paper contributes to understanding on the complexity of depressant responses in froth flotation.

Оrganic Meat Production of Broiler Chickens Hubbard Redbro Cross

2020 ◽  
Keyword(s):  
Broiler Chickens ◽  
Raw Materials ◽  
Animal Health ◽  
Meat Products ◽  
Poultry Meat ◽  
Meat Production ◽  
Significant Difference ◽  
Environmentally Safe ◽  
The Impact

This article presents the results of studying the impact of housing and feeding conditions on broiler chickens of Hubbard RedBro cross, as well as the quality of products obtained when using floor and cage content, in a farm. It established that when receiving a mixed feed of own production using feed raw materials grown on a farm without the use of pesticides, a statistically significant decrease in potentially dangerous substances for animal health is recorded. Compared with factory feed, it has reduced the content of pesticides by 14 times, and mercury and arsenic by 24 times, cadmium by five times, and lead by ten times. The results of the study of economic indicators of growing Hubbard RedBro cross broiler chickens, as well as the chemical composition and quality of carcasses, indicated that there was no significant difference between the floor and cell conditions of keeping. Still, the use of a diet based on eco-feeds contributed to a statistically significant decrease in the concentration of toxic metals in the muscles of the poultry of the experimental groups. As a result, it found that the use of the studied compound feed in the diets of broiler chickens increased the indicators of Biosafety and ensured the production of environmentally safe ("organic") poultry meat products.

Impact of Raw Materials and Processing Techniques on The Microbiological Quality of Egyptian Domiati Cheese

2020 ◽  
Keyword(s):  
Raw Materials ◽  
Microbiological Quality ◽  
Raw Milk ◽  
Plate Count ◽  
E Coli ◽  
Fresh Cheese ◽  
Processing Techniques ◽  
The Impact ◽  
Total Yeast

Domiati cheese is the most popular brand of cheese ripened in brine in the Middle East in terms of consumed quantities. This study was performed to investigate the impact of the microbiological quality of the used raw materials, the applied traditional processing techniques and ripening period on the quality and safety of the produced cheese. Three hundred random composite samples were collected from three factories at Fayoum Governorate, Egypt. Collected samples represent twenty-five each of: raw milk, table salt, calf rennet, microbial rennet, water, environmental air, whey, fresh cheese, ripened cheese & swabs from: worker hands; cheese molds and utensils; tanks. All samples were examined microbiologically for Standard Plate Count (SPC), coliforms count, Staphylococcus aureus (S. aureus) count, total yeast & mould count, presence of E. coli, Salmonellae and Listeria monocytogenes (L. monocytogenes). The mean value of SPC, coliforms, S. aureus and total yeast & mould counts ranged from (79×102 CFU/m3 for air to 13×108 CFU/g for fresh cheese), (7×102 MPN/ cm2 for tank swabs to 80×106 MPN/ml for raw milk), (9×102 CFU/g for salt to 69×106 CFU/g for fresh cheese) and (2×102 CFU/cm2 for hand swabs to 60×104 CFU/g for fresh cheese), respectively. Whereas, E. coli, Salmonella and L. monocytogenes failed to be detected in all examined samples. There were significant differences in all determined microbiological parameters (p ≤0.05) between fresh and ripened cheese which may be attributed to different adverse conditions such as water activity, pH, salt content and temperature carried out to improve the quality of the product.

scholarly journals Consumption of Select Dietary Emulsifiers Exacerbates the Development of Spontaneous Intestinal Adenoma

2021 ◽  
Vol 22 (5) ◽  
pp. 2602
Author(s):  
Emilie Viennois ◽  
Benoit Chassaing
Keyword(s):  
Intestinal Inflammation ◽  
Tumor Development ◽  
Low Grade ◽  
Gastrointestinal Cancers ◽  
Cancer Initiation ◽  
And Function ◽  
The Impact ◽  
Chronic Intestinal Inflammation ◽  
Low Grade Inflammation ◽  
Intestinal Adenoma

Inflammation is a well-characterized critical driver of gastrointestinal cancers. Previous findings have shown that intestinal low-grade inflammation can be promoted by the consumption of select dietary emulsifiers, ubiquitous component of processed foods which alter the composition and function of the gut microbiota. Using a model of colitis-associated cancer, we previously reported that consumption of the dietary emulsifiers carboxymethylcellulose or polysorbate-80 exacerbated colonic tumor development. Here, we investigate the impact of dietary emulsifiers consumption on cancer initiation and progression in a genetical model of intestinal adenomas. In APCmin mice, we observed that dietary emulsifiers consumption enhanced small-intestine tumor development in a way that appeared to be independent of chronic intestinal inflammation but rather associated with emulsifiers’ impact on the proliferative status of the intestinal epithelium as well as on intestinal microbiota composition in both male and female mice. Overall, our findings further support the hypothesis that emulsifier consumption may be a new modifiable risk factor for colorectal cancer (CRC) and that alterations in host–microbiota interactions can favor gastrointestinal carcinogenesis in individuals with a genetical predisposition to such disorders.

scholarly journals 2-Piece Cork Stoppers as Alternative for Valorization of Thin Cork Planks: Analysis by LCA Methodology

Foods ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 873
Author(s):  
Francisco Javier Flor-Montalvo ◽  
Agustín Sánchez-Toledo Ledesma ◽  
Eduardo Martínez Cámara ◽  
Emilio Jiménez-Macías ◽  
Jorge Luis García-Alcaraz ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Raw Materials ◽  
Lca Methodology ◽  
Significant Difference ◽  
Different Dimensions ◽  
The Impact ◽  
Different Thickness ◽  
Cork Stoppers ◽  
Wine Bottle

Natural stoppers are a magnificent closure for the production of aging wines and unique wines, whose application is limited by the availability of raw materials and more specifically of cork sheets of different thickness and quality. The growing demand for quality wine bottle closures leads to the search for alternative stopper production. The two-piece stopper is an alternative since it uses non-usable plates in a conventional way for the production of quality caps. The present study has analyzed the impact of the manufacture of these two-piece stoppers using different methodologies and for different dimensions by developing an LCA (Life Cycle Assessment), concluding that the process phases of the plate, its boiling, and its stabilization, are the phases with the greatest impact. Likewise, it is detected that the impacts in all phases are relatively similar (for one kg of net cork produced), although the volumetric difference between these stoppers represents a significant difference in impacts for each unit produced.

scholarly journals QOL-36. USE OF CANNABINOIDS IN THE PEDIATRIC CENTRAL NERVOUS SYSTEM TUMOR POPULATION

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii438-iii438
Author(s):  
Kathleen Dorris ◽  
Jessica Channell ◽  
Ashley Mettetal ◽  
Molly Hemenway ◽  
Natalie Briones ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Central Nervous System ◽  
Nervous System ◽  
Cell Activity ◽  
Cns Tumors ◽  
Low Grade ◽  
Tumor Type ◽  
Central Nervous System Tumor ◽  
The Impact

Abstract BACKGROUND Cannabinoids, including cannabidiol (CBD) and tetrahydrocannabinol (THC), are a class of compounds found in marijuana. Numerous studies in adults have examined cannabinoid use in management of cancer-related symptoms such as nausea, anorexia, and pain. Less is known about the use in the pediatric oncology population. METHODS A prospective observational study has been ongoing since 2016 at Children’s Hospital Colorado to evaluate cannabinoids’ impact using PedsQL™ modules on quality of life of pediatric patients with central nervous system (CNS) tumors who are 2–18 years old. Laboratory assessments of T-cell activity and pharmacokinetics of CBD, THC and associated metabolites are in process. Diaries with exploratory information on cannabinoid use patterns are being collected. RESULTS Thirty-three patients (14:19; male:female) have been enrolled with a median age of 6.4 years (range, 2.9–17.7 years). The most common tumor type in enrolled patients is embryonal tumors (13/33; 39%). Nine (27%) patients have low-grade glial/glioneuronal tumors, and eight (24%) had high-grade/diffuse midline gliomas. The remaining patients had ependymoma or craniopharyngioma. The median time on cannabinoids is 9 months. Most (n=20) patients have used oral products with CBD and THC. One patient continues on cannabinoid therapy in follow up. Preliminary immune function analyses identified impaired neutrophil superoxide anion production and chemotaxis in patients taking cannabinoids at early time points on therapy. CONCLUSIONS Families of children with various CNS tumors are pursuing cannabinoid therapy for both antitumor and supportive care purposes. Analysis of the impact of cannabinoids on patients’ quality of life is ongoing.

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