Tanning Chemicals’ Influence in Leather Tensile and Tear Strength Review

2020 ◽  
Vol 115 (11) ◽  
pp. 409-412
Author(s):  
Ricardo Tournier

For over 100 years of tanning research, it is still arguable whether tanning chemicals weaken, strengthen or have an effect on the skin's original collagen fibers. The current paper is a review of the literature regarding the impact of the tanning process on the mechanical properties of leather specifically, tensile and tear strength, that raises several questions about this topic. A call is made for the scientific and technical community to address these questions

2020 ◽  
Vol 14 (2) ◽  
pp. 6734-6742
Author(s):  
A. Syamsir ◽  
S. M. Mubin ◽  
N. M. Nor ◽  
V. Anggraini ◽  
S. Nagappan ◽  
...  

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study.  The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.    


Author(s):  
G.A. Murachueva ◽  
I.M. Rasulov ◽  
S.G. Gusenov

A review of the literature on the stages of the formation of temporary and permanent occlusion has been performed. This stages play an important role not only for the full development of the maxillofacial apparatus, temporomandibular joint, but also the whole organism. The role of early tooth extraction in the formation of the physiological state of the dentoalveolar system is considered. The conclusion is drawn about the need for a deeper study of this problem in the structure of general dental morbidity.


Author(s):  
E.N. Glavatskaya , O.V. Pribushenya , N.A. Venchikova

Two clinical cases of meconium peritonitis in the fetuses are presented. The diagnosis was made prenatally at 30+5 and 20+1 weeks of gestation. The main ultrasound signs were ascites, loop expansion and thickening of the intestinal wall, peritoneal calcifications, meconium pseudocysts. In one case, pregnancy was complicated by polyhydramnios. In both cases, the pregnancy ended in premature birth, followed by surgical treatment during the first days of life. A review of the literature on the topic are discussed the etiology, the spectrum and frequency of ultrasound signs suggesting this condition in the fetus, the effectiveness of prenatal diagnosis, the prognosis for the life and health of the newborn, as well as the impact of the quality and timeliness of the prenatal diagnosis on the management of pregnancy and timeliness of surgical care for the newborn.


2019 ◽  
Vol 17 (2) ◽  
pp. 180-190 ◽  
Author(s):  
V. Katsi ◽  
G. Georgiopoulos ◽  
D. Oikonomou ◽  
C. Aggeli ◽  
C. Grassos ◽  
...  

Background: Hypertension (HT) is an important risk factor for cardiovascular disease and might precipitate pathology of the aortic valve. </P><P> Objective: To investigate the association of HT with aortic dysfunction (including both aortic regurgitation and stenosis) and the impact of antihypertensive treatment on the natural course of underlying aortic disease. </P><P> Methods: We performed a systematic review of the literature for all relevant articles assessing the correlation between HT and phenotype of aortic disease. </P><P> Results: Co-existence of HT with aortic stenosis and aortic regurgitation is highly prevalent in hypertensive patients and predicts a worse prognosis. Certain antihypertensive agents may improve haemodynamic parameters (aortic jet velocity, aortic regurgitation volume) and remodeling of the left ventricle, but there is no strong evidence of benefit regarding clinical outcomes. Renin-angiotensin system inhibitors, among other vasodilators, are well-tolerated in aortic stenosis. </P><P> Conclusion: Several lines of evidence support a detrimental association between HT and aortic valve disease. Therefore, HT should be promptly treated in aortic valvulopathy. Despite conventional wisdom, specific vasodilators can be used with caution in aortic stenosis.


2021 ◽  
Vol 11 (10) ◽  
pp. 4658
Author(s):  
Magdalena Januszek ◽  
Paweł Satora

Quality of plum jerkum is significantly associated to the profile of volatile compounds. Therefore, we decided to assess the impact of various fermentation types on selected properties of plum jerkums, especially compounds which contribute to the aroma of the finished product. We used the following yeast strains: S. cerevisiae S1, H. uvarum H2, and Ethanol RED (S. cerevisiae). Moreover, we considered spontaneous fermentation. S. cerevisiae and H. uvarum strains were isolated during the fermentation of Čačanska Lepotica or Węgierka Dąbrowicka (plum cultivars), respectively. As for fermentation type, spontaneous fermentation of H. uvarum H2 provided the best results. It could be associated to the fact that plum juices fermented with H. uvarum H2 presented the highest concentration of terpenoids, esters, or some higher alcohols. In the current paper, application of indigenous strains of yeasts resulted in the required oenological characteristics, e.g., highest fermentation efficiency and concentration of ethanol was determined in juices fermented with Ethanol RED (S. cerevisiae) and also with S. cerevisiae S1. Our results suggested that indigenous strains of yeasts present in plums demonstrate great potential for the production of plum jerkums of high quality.


Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2323
Author(s):  
Yubing Du ◽  
Zhiqing Zhao ◽  
Qiang Xiao ◽  
Feiting Shi ◽  
Jianming Yang ◽  
...  

To explore the basic mechanical properties and size effects of recycled aggregate concrete (RAC) with different substitution ratios of coarse recycled concrete aggregates (CRCAs) to replace natural coarse aggregates (NCA), the failure modes and mechanical parameters of RAC under different loading conditions including compression, splitting tensile resistance and direct shear were compared and analyzed. The conclusions drawn are as follows: the failure mechanisms of concrete with different substitution ratios of CRCAs are similar; with the increase in substitution ratio, the peak compressive stress and peak tensile stress of RAC decrease gradually, the splitting limit displacement decreases, and the splitting tensile modulus slightly increases; with the increase in the concrete cube’s side length, the peak compressive stress of RAC declines gradually, but the integrity after compression is gradually improved; and the increase in the substitution ratio of the recycled aggregate reduces the impact of the size effect on the peak compressive stress of RAC. Furthermore, an influence equation of the coupling effect of the substitution ratio and size effect on the peak compressive stress of RAC was quantitatively established. The research results are of great significance for the engineering application of RAC and the strength selection of RAC structure design.


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