Effects of Different Types and Concentrations of Gelling Agents on the Physical and Chemical Properties of Media and the Growth of Banana (Musaspp.)in Vitro

1999 ◽  
Vol 2 (2) ◽  
pp. 138-145 ◽  
Author(s):  
John Nelson Buah ◽  
Yoshinobu Kawamitsu ◽  
Shigetoshi Sato ◽  
Seiichi Murayama
2018 ◽  
Vol 115 (2) ◽  
pp. 209
Author(s):  
Debjani Nag ◽  
P. Kopparthi ◽  
P.S. Dash ◽  
V.K. Saxena ◽  
S. Chandra

Macerals in coal are of different types: reactive and inert. These macerals are differ in their physical and chemical properties. Column flotation method has been used to separate the reactive macerals in a non-coking coal. The enriched coal is then characterized in order to understand the changes in the coking potential by different techniques. It is then used in making of metallurgical coke by proper blending with other coals. Enriched coal enhance the properties of metallurgical coke. This shows a path of utilization of non-coking coal in metallurgical coke making.


Author(s):  
Loredana Stabili ◽  
Roberto Schirosi ◽  
Angela Di Benedetto ◽  
Alessandro Merendino ◽  
Luciano Villanova ◽  
...  

Although mucus plays many different roles among marine invertebrates, relatively little is known about the link between biochemical structure and function. In the present study we focused on some physical and chemical properties of the polychaeteSabella spallanzanii's mucus such as viscosity, osmolarity, electrical conductivity, elemental composition, the protein and carbohydrate content, the total lipids and fatty acid composition, and polychlorinated biphenyls (PCBs) contamination. Moreover, an antimicrobial activity of the mucus was investigated. The water content ofS. spallanzaniimucus was 96.2±0.3%. By dry weight 26±1.2% was protein, 8±0.21% was carbohydrate and only 0.1% lipid, much of the remainder of the dry weight was inorganic (about 65.2%). The estimated PCBs content was <0.005 μg g−1. The mucus ofS. spallanzaniiexerted a natural lysozyme-like activity and producedin vitrothe growth inhibition ofVibrio anguillarum, Vibrio harveyi, Pseudomonas aeruginosaandCandida albicans.The findings from this study contribute to improve the limited knowledge available on the mucus composition in invertebrates and have implications for future investigations related to employment ofS. spallanzaniimucus as a source of compounds of pharmaceutical and marine technological interest.


1969 ◽  
Vol 15 (6) ◽  
pp. 501-507 ◽  
Author(s):  
M. A. Stillwell ◽  
F. A. Wood ◽  
G. M. Strunz

A growth inhibitor with the molecular formula C10H10O4Cl2 was isolated from a medium which had supported growth of a species of Cryptosporiopsis, an imperfect fungus. The compound was named cryptosporiopsin and was characterized on the basis of its physical and chemical properties. Cryptosporiopsin was active in vitro against many wood-rotting basidiomycetes as well as some phycomycetes, ascomycetes, and deuteromycetes. It was more effective than Dithane M-22 or nystatin against the in vitro spore germination of Phytophthora infestans. It was active to varying degrees against six species of bacteria. Cryptosporiopsin was compared with Orbenin and streptomycin against a penicillin-resistant strain of Staphylococcus aureus.


2015 ◽  
Vol 1111 ◽  
pp. 56-61
Author(s):  
Camelia Szuhanek ◽  
Traian Fleșer

The purpose of our paper was to evaluate the effect of different methods of welding in the laboratory procedures of orthodontic expanders. The results of flame, ultrasound, resistance and laser welding methods were evaluated by means of mechanical testing. Metallographic investigations were also used in order to compare the results of different welding testing. A combination of techniques which offer optimum mechanical, biological, physical and chemical properties must be selected. New results are presented in comparison to previous research with published results.


2021 ◽  
Author(s):  
Dawei Hu ◽  
M. Rami Alfarra ◽  
Kate Szpek ◽  
Justin M. Langridge ◽  
Michael Cotterell ◽  
...  

Abstract. The physical and chemical properties of black carbon (BC) and organic aerosols are important for predicting their radiative forcing in the atmosphere. During the Soot Aerodynamic Size Selection for Optical properties (SASSO) project and a EUROCHAMP-2020 transnational access project, different types of light absorbing carbon were studied, including BC from catalytically stripped diesel exhaust, a flame burner, a colloidal graphite standard (Aquadag), and from controlled flaming wood combustion. Brown carbon (BrC) was also investigated in the form of organic aerosol emissions from wood burning (pyrolysis and smouldering) and from the nitration of secondary organic aerosol (SOA) proxies produced in a photochemical reaction chamber. Here we present insights into the physical and chemical properties of the aerosols, with optical properties being presented in subsequent publications. The dynamic shape factor (χ) of BC particles and material density (ρm) of organic aerosols were investigated by coupling a charging-free Aerodynamic Aerosol Classifier (AAC) with a Centrifugal Particle Mass Analyzer (CPMA) and Scanning Mobility Particle Sizer (SMPS). The morphology of BC particles was captured by transmission electron microscopy (TEM). For BC particles from the diesel engine and flame burner emissions, the primary spherule sizes were similar, around 20 nm. With increasing particle size, BC particles adopted more collapsed/compacted morphologies for the former source but tended to show more aggregated morphologies for the latter source. For particles emitted from the combustion of dry wood samples, the χ of BC particles and the ρm of organic aerosols were observed in the ranges 1.8–2.17 and 1.22–1.32 g/cm3, respectively. Similarly, for wet wood samples, the χ and ρm ranges were 1.2–1.85 and 1.44–1.60 g/cm3, respectively. Aerosol mass spectrometry measurements show no clear difference in mass spectra of the organic aerosols in individual burn phases (pyrolysis or smouldering phase) with the moisture content of the wood samples. This implies that the effect moisture has on the organic chemical profile of wood burning emissions is through changing the durations of the different phases of the burn cycle, not through the chemical modification of the individual phases. In this study, the incandescence signal of a Single Particle Soot Photometer (SP2) was calibrated with three different types of BC particles and compared with that from an Aquadag standard that is commonly used to calibrate SP2 incandescence to a BC mass. A correction factor is defined as the ratio of the incandescence signal from an alternative BC source to that from the Aquadag standard, and took values of 0.82 (or 0.79), 0.88 and 0.84–0.91 for the BC particles emitted from the diesel engine running under hot (or cold idle) conditions, the flame burner and wood combustion, respectively. These correction factors account for differences in instrument response to BC from different sources compared to the standardised Aquadag calibration and are more appropriate than the common value of 0.75 recommended by Laborde et al. (2012b) when deriving the mass concentration of BC emitted from diesel engines. Quantifying the correction factor for many types of BC particles found commonly in the atmosphere may enable better constraints to be placed on this factor depending on the BC source being sampled, and thus improve the accuracy of future SP2 measurements of BC mass concentrations.


2020 ◽  
pp. 088532822095089
Author(s):  
Yuanxing Zhou ◽  
Xiaochi Ma ◽  
Zhonghai Li ◽  
Bo Wang

An effective and viable hemostatic agent is important for stopping bleeding during surgery. However, it is difficult to achieve hemostasis at uneven or deep bleeding sites using a gelatin sponge. A flowable hemostatic agent has therefore been developed by processing and improving gelatin sponge, to address bleeding under these conditions. In this study, we evaluated the efficacy, safety, and physical and chemical properties of this flowable hemostatic agent in various experiments. We examined its efficacy for stopping bleeding in a rabbit model of liver abrasion in vivo, and compared its efficacy in dynamic coagulation and erythrocyte aggregation tests with gelatin sponge in vitro. We also investigated its safety in rat histocompatibility and acute systemic toxicity tests in mice in vivo, and in hemolysis tests in vitro, to determine if the flowable hemostatic agent induced any pathological reactions or adverse events. In terms of its physical and chemical properties, we analyzed the morphology and chemical bonds of the flowable hemostatic agent by optical and electron microscopy and infrared spectroscopy, and its absorbency and density. The flowable hemostatic agent resulted in a shorter mean bleeding time, less bleeding, greater likelihood of successful hemostasis, and reduced clotting time compared with gelatin sponge. The flowable agent produced some changes in physical morphology, but no pathological changes or undesirable outcomes were detected. This flowable topical hemostatic agent thus provides a safe and more effective hemostatic method than gelatin sponge, and more promising results for intraoperative hemostasis, especially on uneven or deep bleeding surfaces.


1974 ◽  
Vol 96 (3) ◽  
pp. 145-156 ◽  
Author(s):  
R. Komanduri ◽  
M. C. Shaw

Scanning electron micrographs of different types of commercial abrasive grains used in grinding are discussed. Surface topography is found useful, along with other physical and chemical properties, in characterizing abrasive materials. The results of this study explain some of the differences in performance of several types of abrasive presently used in grinding practice.


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