scholarly journals Characteristics and Treatment of Wastewater from the Mercaptan Oxidation Process: A Comprehensive Review

Processes ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 425 ◽  
Author(s):  
Ernesto Pino-Cortés ◽  
Silvio Montalvo ◽  
César Huiliñir ◽  
Francisco Cubillos ◽  
Juan Gacitúa
Keyword(s):  
Sodium Hydroxide ◽  
Chemical Properties ◽  
Sulfur Compounds ◽  
High Concentration ◽  
Bibliographic Analysis ◽  
Advantages And Disadvantages ◽  
Spent Caustic ◽  
Mercaptan Oxidation ◽  
Methods Of Treatment ◽  
Very High

Sulfur compounds are removed from petroleum by the addition of sodium hydroxide at a very high concentration. As a result, a residue called spent soda or spent caustic is generated, being extremely aggressive to the environment. In this work, the chemical properties of this residue are described in detail. The sodium hydroxide remains that have not reacted, sulfur compounds, and organic matter are the primary pollutants reported. Additionally, the main characteristics of the methods of treatment used to reduce them are described. This review comes from comprehensive and updated research and bibliographic analysis about the investigation on the topic. The advantages and disadvantages of the different treatment methods are highlighted. We established some criteria to set out when assessing the application of each one of these treatments is considered.

Ground water quality of selected areas of Punjab and Sind Provinces, Pakistan: Chemical and microbiological aspects

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Ionic Concentration ◽  
Chloride Ions ◽  
Potassium Ions ◽  
Ammonium Ions ◽  
High Concentration ◽  
Phosphate Ions ◽  
Sodium Magnesium ◽  
Very High ◽  
Microbiological Aspects

The assessment of groundwater is essential for the estimation of suitability of water for safe use. An attempt has been made to study the groundwater of selected areas of Punjab (Sheikhupura & Sahiwal) and Sindh (Sindh, Jawar Dharki and Dharki), Pakistan. The results indicate that pH, color and odor were all within limits of WHO that is pH ranges 6.5–8.5, colorless and odorless, respectively. The high values of suspended solids were observed in the Sindh-1 and Dharki samples. Microbiologically only Sahiwal and Jawar Dharki were found fit for drinking purpose. Trace metals analysis of Sheikhupura-1 and Sindh-1 showed that values do not fall within limits of WHO for Iron. The ionic concentration analysis showed that high bicarbonate (HCO3-), ions are present in the samples of Sahiwal and Dharki; Sindh-1 and Jawar Dharki samples showed very high concentration for chloride ions, all samples were satisfactory level for sulphate (SO42-), sodium, magnesium and phosphate ions except samples of Sindh-1 and Jawar Dharki. High concentration of calcium and potassium ions was observed in samples of Sindh-1, while all other samples were found fit for drinking purposes in respect of nitrate, nitrite and ammonium ions. The high concentration of Fluoride was found only in Sheikhupura-2 samples.

scholarly journals How to Improve Physico-Chemical Properties of Silk Fibroin Materials for Biomedical Applications?—Blending and Cross-Linking of Silk Fibroin—A Review

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1510
Author(s):  
Sylwia Grabska-Zielińska ◽  
Alina Sionkowska
Keyword(s):  
Silk Fibroin ◽  
Biomedical Applications ◽  
Magnetic Particles ◽  
Chemical Properties ◽  
Ternary Mixtures ◽  
Cross Linking ◽  
Advantages And Disadvantages ◽  
Physico Chemical ◽  
Binary And Ternary Mixtures ◽  
To Receive

This review supplies a report on fresh advances in the field of silk fibroin (SF) biopolymer and its blends with biopolymers as new biomaterials. The review also includes a subsection about silk fibroin mixtures with synthetic polymers. Silk fibroin is commonly used to receive biomaterials. However, the materials based on pure polymer present low mechanical parameters, and high enzymatic degradation rate. These properties can be problematic for tissue engineering applications. An increased interest in two- and three-component mixtures and chemically cross-linked materials has been observed due to their improved physico-chemical properties. These materials can be attractive and desirable for both academic, and, industrial attention because they expose improvements in properties required in the biomedical field. The structure, forms, methods of preparation, and some physico-chemical properties of silk fibroin are discussed in this review. Detailed examples are also given from scientific reports and practical experiments. The most common biopolymers: collagen (Coll), chitosan (CTS), alginate (AL), and hyaluronic acid (HA) are discussed as components of silk fibroin-based mixtures. Examples of binary and ternary mixtures, composites with the addition of magnetic particles, hydroxyapatite or titanium dioxide are also included and given. Additionally, the advantages and disadvantages of chemical, physical, and enzymatic cross-linking were demonstrated.

scholarly journals Near quantitative synthesis of urea macrocycles enabled by bulky N-substituent

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yingfeng Yang ◽  
Hanze Ying ◽  
Zhixia Li ◽  
Jiang Wang ◽  
Yingying Chen ◽  
...  
Keyword(s):  
High Efficiency ◽  
Molecular Structures ◽  
High Yield ◽  
Kinetic Control ◽  
High Concentration ◽  
Weak Association ◽  
Quantitative Synthesis ◽  
Thermodynamic Stabilization ◽  
Discrete Structures ◽  
Very High

AbstractMacrocycles are unique molecular structures extensively used in the design of catalysts, therapeutics and supramolecular assemblies. Among all reactions reported to date, systems that can produce macrocycles in high yield under high reaction concentrations are rare. Here we report the use of dynamic hindered urea bond (HUB) for the construction of urea macrocycles with very high efficiency. Mixing of equal molar diisocyanate and hindered diamine leads to formation of macrocycles with discrete structures in nearly quantitative yields under high concentration of reactants. The bulky N-tert-butyl plays key roles to facilitate the formation of macrocycles, providing not only the kinetic control due to the formation of the cyclization-promoting cis C = O/tert-butyl conformation, but also possibly the thermodynamic stabilization of macrocycles with weak association interactions. The bulky N-tert-butyl can be readily removed by acid to eliminate the dynamicity of HUB and stabilize the macrocycle structures.

Small-volume vitrification and rapid warming yield high survivals of one-cell rat embryos in cryotubes

2021 ◽  
Author(s):  
Yasuyoshi Fukuda ◽  
Misako Higashiya ◽  
Takahiro Obata ◽  
Keita Basaki ◽  
Megumi Yano ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Small Volume ◽  
Sucrose Solution ◽  
High Concentration ◽  
Rat Embryos ◽  
Low Concentrations ◽  
Intracellular Ice Formation ◽  
Intracellular Ice ◽  
Warming Rate ◽  
Very High

Abstract To cryopreserve cells, it is essential to avoid intracellular ice formation during cooling and warming. One way to achieve this is to convert the water inside the cells into a non-crystalline glass. It is currently believed that to accomplish this vitrification, the cells must be suspended in a very high concentration (20–40%) of a glass-inducing solute, and subsequently cooled very rapidly. Herein, we report that this belief is erroneous with respect to the vitrification of one-cell rat embryos. In the present study, one-cell rat embryos were vitrified with 5 μL of EFS10 (a mixture of 10% ethylene glycol, 27% Ficoll, and 0.45 M sucrose) in cryotubes at a moderate cooling rate, and warmed at various rates. Survival was assessed according to the ability of the cells to develop into blastocysts and to develop to term. When embryos were vitrified at a 2,613 °C/min cooling rate and thawed by adding 1 mL of sucrose solution (0.3 M, 50 °C) at a warming rate of 18,467 °C/min, 58.1 ± 3.5% of the EFS10-vitrified embryos developed into blastocysts, and 50.0 ± 4.7% developed to term. These rates were similar to those of non-treated intact embryos. Using a conventional cryotube, we achieved developmental capabilities in one-cell rat embryos by rapid warming that were comparable to those of intact embryos, even using low concentrations (10%) of cell-permeating cryoprotectant and at low cooling rates.

scholarly journals Nuclear mass measurements with radioactive ion beams

2019 ◽  
Vol 28 (04) ◽  
pp. 1930005 ◽  
Author(s):  
Michael A. Famiano
Keyword(s):  
Mass Measurement ◽  
Measurement Techniques ◽  
Nuclear Mass ◽  
Mass Measurements ◽  
Future Directions ◽  
Advantages And Disadvantages ◽  
Nuclear Masses ◽  
Under Construction ◽  
Very High ◽  
Practical Constraints

Nuclear masses are the most fundamental of all nuclear properties, yet they can provide a wealth of knowledge, including information on astrophysical sites, constraints on existing theory, and fundamental symmetries. In nearly all applications, it is necessary to measure nuclear masses with very high precision. As mass measurements push to more short-lived and more massive nuclei, the practical constraints on mass measurement techniques become more exacting. Various techniques used to measure nuclear masses, including their advantages and disadvantages are described. Descriptions of some of the world facilities at which the nuclear mass measurements are performed are given, and brief summaries of planned facilities are presented. Future directions are mentioned, and conclusions are presented which provide a possible outlook and emphasis on upcoming plans for nuclear mass measurements at existing facilities, those under construction, and those being planned.

Second Paper: Failure-Survival Automatic Flight Control Systems for Aircraft with Particular Reference to a High Reliability Electrohydraulic Actuator

1965 ◽  
Vol 180 (1) ◽  
pp. 246-259
Author(s):  
R. Ruggles
Keyword(s):  
Control System ◽  
Control Systems ◽  
Flight Control ◽  
High Reliability ◽  
Supply System ◽  
Design Criteria ◽  
Flight Control System ◽  
Advantages And Disadvantages ◽  
System Configurations ◽  
Very High

The author discusses some of the problems of failure-survival automatic flight control systems and suggests some basic ground rules as design criteria. The advantages and disadvantages of some of the main types of system are discussed: duplex, triplex, triple component, duplicate-monitored and quadruplex systems being covered. In particular, a quadruplex actuator is described which has been designed and developed mainly for automatic flight control system applications where a very high degrees of failure-survival capability is required. A detailed failure analysis of the various systems is carried out and the importance of the electrical and hydraulic supply system configurations and failure rates is brought out.

scholarly journals Waste Tire Particles and Gamma Radiation as Modifiers of the Mechanical Properties of Concrete

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Eduardo Sadot Herrera-Sosa ◽  
Gonzalo Martínez-Barrera ◽  
Carlos Barrera-Díaz ◽  
Epifanio Cruz-Zaragoza
Keyword(s):  
Mechanical Properties ◽  
Gamma Radiation ◽  
Chemical Properties ◽  
Plain Concrete ◽  
Cement Matrix ◽  
Portland Cement Concrete ◽  
High Concentration ◽  
Good Tool ◽  
Waste Tire ◽  
Physical And Chemical

In polymer reinforced concrete, the Young’s modulus of both polymers and cement matrix is responsible for the detrimental properties of the concrete, including compressive and tensile strength, as well as stiffness. A novel methodology for solving such problems is based on use of ionizing radiation, which has proven to be a good tool for improvement on physical and chemical properties of several materials including polymers, ceramics, and composites. In this work, particles of 0.85 mm and 2.80 mm obtained from waste tire were submitted at 250 kGy of gamma radiation in order to modify their physicochemical properties and then used as reinforcement in Portland cement concrete for improving mechanical properties. The results show diminution on mechanical properties in both kinds of concrete without (or with) irradiated tire particles with respect to plain concrete. Nevertheless such diminutions (from 2 to 16%) are compensated with the use of high concentration of waste tire particles (30%), which ensures that the concrete will not significantly increase the cost.

Materials and Photosensor Devices with High Radiation Stability

2015 ◽  
Vol 1117 ◽  
pp. 107-113 ◽  
Author(s):  
Ilariy Rarenko ◽  
Dmytro Korbutyak ◽  
Volodymyr Koshkin ◽  
Boris Danilchenko ◽  
Leonid Kosyachenko ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Metal Layer ◽  
Chemical Properties ◽  
Radiation Stability ◽  
Reactor Irradiation ◽  
High Concentration ◽  
High Radiation ◽  
Cubic Crystal ◽  
Impurity Atoms ◽  
Mixed Reactor

Semiconductor Hg3In2Te6 crystals and their analogous are solid solutions of In2Te3 and HgTe. Hg3In2Te6 crystals are congruently melted as chemical compound. Like In2Te3 the Hg3In2Te6 crystal has cubic crystal lattice with stoichiometric vacancies in their crystal structure. The electroconductivity, photoconductivity, mechanical, chemical properties of the crystals do not deteriorate after their irradiation by γ-photons with energies up to 1 MeV and doses up to 1018 cm-2 , by electrons with energies up to 300 MeV and doses up to 1019 cm-2 and by mixed reactor irradiation (filtered slow neutrons) with doses up to 1019 cm-2 [1,2]. This feature is determined by high concentration (~1021 cm-3) of stoihiometric vacancies (Vs) in crystal structure, where every third In-cation node is empty. These Vs are electroneutral, they capture all impurity atoms in these crystals and kept them in electroneutral state too. On the other hand this feature doesn't allow to form direct p-n junctions in these crystals by introducing the impurities. However, we have developed p-n junction analogues in form of Schottki diodes and corresponding photodiodes with semitransparent metal layer on single crystal Hg3In2Te6 substrate that allows irradiation to get into active region preserving this way all the advantages compared to p-n junction.

Diffusion In Insect Wing Muscle, The Most Active Tissue Known

1964 ◽  
Vol 41 (2) ◽  
pp. 229-256 ◽  
Author(s):  
TORKEL WEIS-FOGH
Keyword(s):  
Liquid Phase ◽  
Safety Factor ◽  
Metabolic Rates ◽  
High Concentration ◽  
Tracheal System ◽  
Insect Wing ◽  
Main Site ◽  
Normal Diffusion ◽  
Large Fibre ◽  
Very High

1. The tracheal system of insect wing muscle is so dense that between 10-1 and 10-3 of any cut area is occupied by air tubes. In most cases, air tube diffusion of O2 and CO2 through the muscle is therefore several thousand times quicker than diffusion in the liquid phase. 2. In large insects the primary tracheal supply must be strongly ventilated while diffusion is sufficient in the remaining part of the air tubes, even at the highest metabolic rates encountered in any insect. 3. The tracheoles represent the main site of exchange between the gaseous and the liquid phase while the tracheae are of little significance in this respect. The fibres cannot exceed about 20 µ in diameter unless the tracheoles indent the surface and become ‘internal’. 4. Muscular pumping of air and blood due to shortening is of little importance for the exchange of gases but of major importance for the supply with fuel for combustion. However, the large fibre diameters and the tidal nature of the pumping necessitates a very high concentration of fuel in the haemolymph. The high concentration of trehalose in insect blood is considered to be an essential adaptation to flapping flight. 5. The transport by diffusion of O2 and CO2 was followed in detail in a number of concrete examples in the gaseous as well as in the liquid phase. Within a safety factor of 2-3, the rate of transport was always found to be adequate. There is no reason to suggest other mechanisms than a simple, normal diffusion.

Vaporization and Ultra-Fine Particle Generation during the Plasma Spraying Process

1997 ◽  
Author(s):  
K.A. Gross ◽  
P. Fauchais ◽  
M. Vardelle ◽  
J. Tikkanen ◽  
J. Keskinen
Keyword(s):  
Fine Particles ◽  
High Concentration ◽  
Thermal Spray Process ◽  
Particle Generation ◽  
Spray Process ◽  
Ultra Fine Particle ◽  
Fast Cooling ◽  
Ultra Fine Particles ◽  
Plasma Spraying Process ◽  
Very High

Abstract The thermal spray process melts powder at very high temperatures and propels the molten material to the substrate to produce a coherent deposit. This heating produces a certain amount of vaporization of the feedstock. Upon exiting the plasma plume the fast cooling conditions lead to condensation of the vapor. An electrical low pressure impactor was used to monitor the concentration of ultra-fine particles at various radial and axial distances. Metal, namely iron powder, showed very high concentration levels which increase with distance. Ultra-fine particles from ZrO2-8Y2O3 reached a peak concentration at 6 cm. Use of an air barrier during spraying decreases the population of ultra-fine particles facilitating the production of a stronger coating.

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