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2022 ◽  
Vol 10 (1) ◽  
Author(s):  
Gabriela Vyskočilová ◽  
Cristina Carşote ◽  
Richard Ševčík ◽  
Elena Badea

AbstractIn this study we used an analytical approach based on complementary techniques that targets all structural levels of collagen in leather to investigate how vegetable-tanned leather deteriorates during soil burial tests. For the first time, a group of deterioration markers specific to molecular, fibrillar and fibrous structure of collagen in leather was associated with the deterioration of buried leather. The application of the second order derivative of FTIR-ATR spectra analysis allowed us to detect loosening of collagen–tannin matrix, de-tanning and gelatin formation based on the behaviour of collagen and tannin spectral components (intensity variation and shifts). Collagen denaturation observed by DSC analysis and its thermo-oxidative behaviour measured by TG/DTG analysis, as well as the altered morphology of collagen (namely melt-like fibres and distorted fibrillar ultrastructure) imaged by SEM confirmed the FTIR-ATR analyis results. These analytical outcomes enabled us to understand the effect of leather hardening/cementing through soil mineral penetration into its fibrous structure and thus correctly interprete the higher-than-expected shrinkage temperatures and intervals determinatd by MHT method. Thus, MHT method proved to be suitable for a quick evaluation method that can direcly support the first conservation decision after excavation. The combination of FTIR-ATR, DSC, TG/DTG and SEM can be particularly useful to provide insights on the deterioration mechanism of archaeological leather and support best decision on its long-term preservation.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
V.K. Swami ◽  
V.K. Swami ◽  
V.K. Swami

Corrosion is the destruction of metal surface by the reaction with its environment (humidity, gases, acid, alkaline etc.). In this process metal convert in to the more stable form such as sulphide oxide etc. Corrosion of materials and structures is a hindrance to the development of society as it causes significant loss to the economy, leads to pollution, and leads to serious disasters, hence its prevention and control is of great benefit for the humanity. Addition of corrosion inhibitors is one of the practical and easy methods to protect metals and alloys against attack of corrosion in many industrial environments. In this chapter thiosemicarbazide based Schiff base 2-[(3,4-dihydroxy-5-nitrophenyl)methylidene]hydrazine1-carbothioamide (DHNPMHC) was synthesized and characterized using elemental analysis, FT-IR and UV–Vis methods. The inhibition efficiency of Schiff base DHNPMHC against aluminium corrosion in 0.5 M HCl was examined using mass loss measurement and scanning electron microscopy (SEM). Results showed that DHNPMHC is an effective inhibitor for aluminium corrosion in 0.5 M HCl solution. The inhibition efficiency also increased with concentration of inhibitor increased. Maximum percentage inhibition efficiency 92.6 % (at 4-hour immersion time) is shown at highest concentration of inhibitor 5% (5X10-5M). Adsorption of the inhibitor on the aluminium surface followed Langmuir adsorption isotherm. SEM study of aluminium surface in presence of inhibitor and in absence of inhibitor also supports the inhibition of corrosion in acidic medium. All results show that the Schiff base of thiosemicarbazide (DHNPMHC) is excellent corrosion inhibitor for aluminium in 0.5 M HCl.


2021 ◽  
Vol 22 (9) ◽  
pp. 1003-1007
Author(s):  
Maitri Shah ◽  
Pavithra K Ramanna ◽  
Abhinav K Singh ◽  
Arti Dixit ◽  
Deesha Kumari ◽  
...  

Pharmaceutics ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2094
Author(s):  
Mohammed Jafar ◽  
Mohammed Salahuddin ◽  
Mohd Sajjad Ahmad Khan ◽  
Yasir Alshehry ◽  
Nazar Radwan Alrwaili ◽  
...  

The current study aimed to develop a luteolin gastric floating microsponge for targeting Helicobacter pylori. The microsponge formulations were prepared by a quasi-emulsion method, and then evaluated for various physicochemical variables. The best microsponge was further assessed for drug-polymer interactions, surface morphology, in vivo floating, and in vitro anti H. pylori activity. The formulation which exhibited comparatively good production yield (64.45% ± 0.83), high entrapment efficiency (67.33% ± 3.79), prolonged in vitro floating time (>8 h), and sustained in-vitro drug release was selected as the best microsponge. The SEM study revealed that the best microsponge was spherical in shape and has a porous surface with interconnecting channels. DSC and XRD studies demonstrated the dispersion of luteolin in the polymeric matrix of the microsponge. Ultrasonography confirmed that the best microsponge could in the rat stomach for 4 h. The in vitro MIC results indicate that the anti H. pylori activity of the best microsponge was almost doubled and more sustained compared to pure luteolin. To conclude, it can be said that the developed luteolin gastric floating microsponge could be a better option to effectively eradicate H. pylori infections and the histopathological and pharmacodynamic assessments of our best microsponge can be expected to provide a rewarding outcome.


2021 ◽  
Vol 2114 (1) ◽  
pp. 012061
Author(s):  
Layth Al-Jaberi ◽  
Al-Saraj K. Wissam Al-Saraj ◽  
Al-Serai J. Sahar Al-Serai

Abstract This work is a Scanning Electron Microscope (SEM) study to investigate the behaviour of Metakaolin based GPC mixes with and without cement and containing recycled concrete aggregate. Three (3) GPC mixes and Normal Concrete mix (NC) designed mingled and tested to achieve the goals of this research. Control specimens were cast from each mix to determine the mechanical properties for each mix. (12) SEM micrographs from carefully selected samples. SEM study confirmed that the presence of recycled concrete aggregate can be a source of generating cracks and fissures. The un-hydrated cement particles in recycled aggregate can contribute to further hydration when contact with water. Also, the metakaolin based GPC matrix with natural aggregate showed enormous with unrealized morphology, which indicates amorphous. Finally, the replacement of 20% of Metakaolin with cement led to enhance mechanical properties.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12559
Author(s):  
Karolina Goździewska-Harłajczuk ◽  
Pavla Hamouzová ◽  
Joanna Klećkowska-Nawrot ◽  
Petr Čížek

In the light of recent molecular studies, there are two phylogenetic species of the red panda (Ailurus fulgens): Ailurus fulgens fulgens and Ailurus fulgens styani. The red panda belongs to the endangered species living in the wild only in Asia and is included in the CITES list. Although the biology and diet of this species has been extensively described, the histological structure of the tongue and lingual glands has not yet been characterized in detail in relation to the lifestyle of this mammal under specific conditions and as a basis for comparative anatomical studies of the biodiversity of endemic species. Study samples were collected from two adult males of Ailurus fulgens f. held in Wrocław Zoological Garden. Both tongues were examined macroscopically; moreover, samples with lingual papillae for light microscopy and scanning electron microscopy (SEM) were collected from the apex, body and root of the tongue. Both tongues of the Ailurus fulgens f. males were approximately 9 cm long. The dorsal lingual surface was covered with mechanical and gustatory lingual papillae. Filiform papillae were observed on the apex and the body of the tongue, while small conical papillae were observed on the root of the tongue. An elongated, 1–1.5 cm long cylinder-shaped lyssa was observed in the ventral part of the apex. Moreover, most numerous and largest round in shape fungiform papillae were observed on the apex and on the border of the body and root of the tongue, located directly rostrally to 12–13 round and oval in shape vallate papillae. The SEM study showed that filiform papillae on the apex had several long secondary processes, while filiform papillae on the body of the tongue were taller and their secondary papillae were shorter than the equivalent structures on the apex of the tongue. The SEM study showed numerous taste pores on the surface of the fungiform papilla, while irregular surface of the vallate papillae, however some of them had smoother surface. Mixed glands (comprised of mucous acini and serous acini) were present within the vallum (within the connective tissue core) of the vallate papilla. Beneath the papillae more serous glands were observed, while the posterior lingual glands in the caudal part of the root of the tongue were mucoserous (mucous units were prevalent). A characteristic feature of the tongue of Ailurus fulgens f. was the presence of lyssa, which is comparable to other representatives of Carnivora, but the number of vallate papillae was individually variable. The lack of strongly developed mechanical conical papillae probably may be related to the type of plant food that is particularly dominant in red panda. Further differences between Ailurus fulgens f. and Ailurus fulgens s. cannot be excluded. The results of these studies may be useful especially for veterinarians specializing in working with exotic animals and people dealing with wildlife conservation.


Materials ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7099
Author(s):  
Evgeniya Il’ina ◽  
Svetlana Pershina ◽  
Boris Antonov ◽  
Alexander Pankratov

All-solid-state lithium-ion batteries raise the issue of high resistance at the interface between solid electrolyte and electrode materials that needs to be addressed. The article investigates the effect of a low-melting Li3BO3 additive introduced into LiCoO2- and Li4Ti5O12-based composite electrodes on the interface resistance with a Li7La3Zr2O12 solid electrolyte. According to DSC analysis, interaction in the studied mixtures with Li3BO3 begins at 768 and 725 °C for LiCoO2 and Li4Ti5O12, respectively. The resistance of half-cells with different contents of Li3BO3 additive after heating at 700 and 720 °C was studied by impedance spectroscopy in the temperature range of 25–340 °C. It was established that the introduction of 5 wt% Li3BO3 into LiCoO2 and heat treatment at 720 °C led to the greatest decrease in the interface resistance from 260 to 40 Ω cm2 at 300 °C in comparison with pure LiCoO2. An SEM study demonstrated that the addition of the low-melting component to electrode mass gave better contact with ceramics. It was shown that an increase in the annealing temperature of unmodified cells with Li4Ti5O12 led to a decrease in the interface resistance. It was found that the interface resistance between composite anodes and solid electrolyte had lower values compared to Li4Ti5O12|Li7La3Zr2O12 half-cells. It was established that the resistance of cells with the Li4Ti5O12/Li3BO3 composite anode annealed at 720 °C decreased from 97.2 (x = 0) to 7.0 kΩ cm2 (x = 5 wt% Li3BO3) at 150 °C.


Author(s):  
Aman Mallick ◽  
Gaurav Malhotra ◽  
Pradeep Shukla ◽  
Prerna Kataria ◽  
C. S Joshi

Introduction: Dentine hypersensitivity (DH) occurs on exposed dentine and is dependent on the patency of dentinal tubules. This study compared the effectiveness of toothpaste containing Strontium Chloride, Novamine, Pro-Arginine in occluding dentine tubules along with comparision of those. Materials and Method: 45 freshly extracted teeth were randomly divided (15 each) into 3 groups: Group 1 15 Teeth treated with toothpaste containing Strontium Chloride. Group 2 15 Teeth treated with toothpaste containing Novamine Group 3 15 Teeth treated with toothpaste containing Pro-Arginine. Each specimen was brushed with the dentifrice slurries and examined under SCM. Result: The mean of occluded dentinal tubules on the dentin surface after brushing with three dentifrices were significant among them Pro-arginine group showed maximum occlusion. Conclusion: The present in vitro SEM study results revealed that:  All the experimental agents– Strontium chloride, novamin, Pro- Argenine were effective in occluding dentinal tubules & the percentage (%) of occluded tubules was found to be highest for Pro- Argenine as compared to the other groups. Keywords: SCM, DH


2021 ◽  
Vol 1 (2) ◽  
pp. 33-36
Author(s):  
Gomasa Ramesh

The sum of CO2 that has been released into the atmosphere is roughly equal to the amount of cement produced. Cement manufacturing now consumes many natural resources and cement substitute materials in the analysis of Micro Structural Properties of Ternary Blended Concrete. The mixed proportion in this analysis is made of M30 Concrete. The cement is substituted with a mixture of two materials in amounts ranging from 10% to 50%. For the mix of materials, Fly Ash is kept constant. The specimen is a 150mmx150mmx150mm cube, and the concrete is cast in a 150mmx300mm cylinder. The cast specimens are held for 28 days to cure. Compressive and split tensile strength tests are used to achieve the results. The combination at 10%, at 20%, at 20%, and 20% produced better strength results in all proportions from 10% to 50%. Besides, scanning electron microscopy techniques were used to understand better phase changes and the formation of microstructures to maturing the combination of materials at various percentages. SEM was used to evaluate the microstructure of the concrete for five different varieties, which helps with solid growth. With the highest compressive strength gained among all the mixes from 10% to 50% with combinations for M30 grade of concrete at 28 days, significant innovative information on particle shape and microstructure was observed. Via SEM study, a good correlation of this Microscopical quantitative knowledge and material properties is also presented.


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