Thermosensitive and Wound-Healing Gelatin-Alginate Biopolymer Hydrogels Modified with Humic Acids

The main goal of the article is the creation and study of thermosensitive and wound-healing gelatin-alginate bio-polymer hydrogels modified with humic acids.Their rheological properties,swelling and contraction behavior were experimentally investigated,elucidated using Fourier transform infrared spectroscopy and used to achieve the physiological melting point,which is necessary for successful drug delivery.It has been shown that in the gelatin-alginate-humic acid biopolymer hydrogels systems,it is possible to obtain a gel-sol transition temperature close to the physiological temperature of 37℃,which is important for drug delivery in the treatment of wounds.By changing the type and concentration of humic acids in the gelatin-alginate hydrogel,it turned out to be achiev-able to regulate the softening time of the gel on the human body in the range from 6 to 20 min,which provides the possibility of controlled prolonged delivery of drugs.Based on the study of the influence of calcium ions on the properties of humic acids and ion exchange,as well as the interaction of humic acids,sodium alginate and gelatin with the formation of tighter gel networks,approaches to regulate the rate of softening of hydrogels at physiological temperature and their swelling,which simulates the absorption of exudate,were proposed and implemented.In addition,low shrinkage of the hydrogel surface due to cross-linking of gelatin-alginate networks when modified with humic acids was experimentally confirmed,which is important for avoiding problems of wound contracture and contour deformations when using dressings for wound healing.Thus,the developed opti-mized innovative biopolymer hydrogels synergistically combine the outstanding properties of natural molecular polymers and humic acids and are promising for the creation of effective medicines for wound healing.

Effect of hydrodynamic desulphurisation of low parameters on the oxidative rank coal

In this paper, the desulphurisation of high sulphur low-rank coal is proposed as a raw material for pulverised coal injection technology. Therefore, the influence of oxidant linear velocity and the size of the coal grain was investigated in a fluidised bed. The hydrodynamic parameters of the fluidised bed including： porosity, Sherwood criterion （diffusion Nusselt number）, and mass transfer coefficient （external surface） were calculated. Furthermore, the study examined the effects of intensity and efficiency on the desulphurised coal properties; organic matter, ash, and volatile matter contents. The key changes during the conversion of pyritic sulphur and coal organic matter were subsequently examined. The results showed that the sulphur content （St^d 3.16 wt%） of the low-rank coal, was transformed to （St^d 〈 1.5 wt%） after desulfurization. Other enhanced properties were： V^daf ≤ 38.0 wt%; A^d 〈 10.0 wt%, now suitable for pulverised coal injection technology.

Export competitiveness of agricultural products and agricultural sustainability in China

The competitiveness of a country’s agricultural products is not only related to its capacity to export agricultural products,but also to the sustainability of its agricultural sector.How to improve the international competitiveness of a country’s agricultural products while maintaining the sustainability of its agricultural sector is a practical problem of great urgency for a country with a large agricultural sector such as China.With this in mind,this study should have a considerable policy and practical significance.We used two evaluation indices,namely trade competitiveness(TC)index and revealed comparative advantage(RCA)index,to measure and analyze the international competitiveness of six China’s representative agricultural products,i.e.,live pigs,live chickens,live cattle,apples,tea,and beer,and to examine the changing trends of these products’competitiveness during 1994-2013.The results indicate that the export competitiveness of China’s agricultural products is weak and likely to deteriorate further.However,some traditional agricultural products with distinctive regional characteristics,for example,tea and live pigs,are relatively strong internationally.To this end,China should vigorously promote the production and foreign trade in traditional agricultural products with distinctive regional characteristics.At the same time,comprehensive measures should be taken to enhance the international competitiveness of disadvantaged agricultural products.

Subsolidus Conceptual Design of CaO-AI_2O_3-TiO_2-SiO_2 System and Its Significance for Manufacturing Advanced Ceramics

The article deals the structure of the CaO -Al2O3 - TiO2 -SiO2 system as a basis for obtaining advanced ce- ramics with a complex of high-operational characteris- tics. As a result o[＇investigations the phase charctcteristics are represented trod the graph of the relationship of the elementaory tetrahedra has been plotted. The most techno- logical system area ,for the production of heat resistant advanced ceramics has been determined. The batches for producing heat and chemical resistant dense advanced ceramics made of natural, technical and technogenic raw materials have been developed.

Thermodynamics of Phase Equilibria in FeO-TiO2-Al_(2)O_(3)System

This scientific paper discusses the information on the structure of the three-component system FeO-TiO_(2)-Al_(2)O_(3),which is necessary for the creation of heat-resistant oxide materials.The structure of binary systems:FeO-Al_(2)O_(3),FeO-TiO_(2),and Al_(2)O_(3)-TiO_(2)is described,and the data on the FeO-TiO_(2)-Al_(2)O_(3)system are presented.The thermodynamic data of all compounds of the system are given,on the basis of which the change in the Gibbs free energy in the temperature range of 800-1900 K for twenty-one exchange reactions was calculated.It has been established that the triangulation of the FeO-TiO_(2)-Al_(2)O_(3)system changes in five temperature ranges:up to 1408 K(TiO_(2)exists in the polymorphic modification-anatase),1408-1537 K(TiO_(2)exists in the polymorphic modification-rutile and pseudobrookite is stable),1537-1630 K(thialite is stable),1630-2076 K(rearrangement cannot occur)and above 2076 K(the presence of the stoichiometric compound Al_(4)TiO_(8)is allowed).Two-phase equilibria up to 1408 K are stable:Al_(2)O_(3)-FeTiO_(3),FeTiO_(3)-FeAl_(2)O_(4),and FeAl_(2)O_(4)-Fe_(2)TiO_(4);in the temperature range of 1408-1537 K:FeAl_(2)O_(4)-TiO_(2),FeAl_(2)O_(4)-FeTi_(2)O_(5),FeAl_(2)O_(4)-FeTiO_(3),and FeAl_(2)O_(4)-Fe_(2)TiO_(4);in the temperature range of 1537-1630 K:FeAl_(2)O_(4)-TiO_(2),FeAl_(2)O_(4)-FeTi_(2)O_(5),FeAl_(2)O_(4)-FeTiO_(3),FeAl_(2)O_(4)-Fe_(2)TiO_(4),and FeAl_(2)O_(4)-Al_(2)TiO_(5);in the temperature range of 1630-2076 K:FeTi_(2)O_(5)-Al_(2)TiO_(5),Al_(2)TiO_(5)-FeTiO_(3),FeTiO_(3)-Al_(2)O_(3),FeTiO_(3)-FeAl_(2)O_(4),and FeAl_(2)O_(4)-Fe_(2)TiO_(4);over 2076 K:FeTi_(2)O_(5)-Al_(2)TiO_(5),FeTi_(2)O_(5)-Al_(4)TiO_(8),Al_(4)TiO_(8)-FeTiO_(3),Al_(4)TiO_(8)-Fe_(2)TiO_(4),Al_(4)TiO_(8)-FeO,and Al_(4)TiO_(8)-FeAl_(2)O_(4).

Thermodynamic Modeling of MgO-Al_(2)O_(3)-TiO_(2) System

This scientific paper gives consideration to the information on the structure of the triple component system,in particular MgO-Al_(2)O_(3)-TiO_(2) that serves as a basis for the production of thermal resistance materials.The structure of such binary systems as MgO-Al_(2)O_(3),Al_(2)O_(3)-TiO_(2),MgO-TiO_(2) was described and the data available for the MgO-Al_(2)O_(3)-TiO_(2) system were given.Thermodynamic data on all the system compounds were also presented and used for the computation of a change in the free Gibbs energy in the temperature range form 800 K to 1900 K for the basic exchange reactions.It was established that the triangulation of the MgO-Al_(2)O_(3)-TiO_(2) system was changed in the three temperature intervals:in the temperature range lower than 1537 K TiO_(2) existed as the polymorphous modification,i.e.anatase;in the temperature range from 1537 K to 2076 K TiO_(2) existed as a polymorphous modification in form of rutile and tialite was stable;and at the temperatures above 2076 K the availability of stochiometric compound of Al4TiO_(8) was possible.In the temperature range lower than 1537 K the two-phase equilibra of Al_(2)O_(3)-MgTi2O_(5),Mg-MgALCU MgTiO_(3)-MgAl_(2)O_(4),and Mg_(2)TiO_(4)-MgAl_(2)O_(4) were stable;in the temperature range from 1537 K to 2076 K the two-phase equilibria of MgTigO_(5)-AlgTiO_(5),MgTiO_(3)-Al_(2)TiO_(5),MgTiO_(3)-Al_(2)O_(3),MgTiO_(3)-MgAl_(2)O_(4),and Mg_(2)TiO_(4)-MgAl_(2)O_(4) were stable,and above 2076 K the MgTi_(2)O_(5)-Al_(2)TiO_(5),MgTi_(2)O_(5)-Al_(4)TiO_(8),Al_(4)TiO_(8)-MgTiO_(3),Al_(4)TiO_(8)-Mg_(2)TiO_(4),Al_(4)TiO_(8)-Mg0,and Al_(4)TiO_(8)-MgAl_(2)O_(4) systems were stable.

Numerical simulation of warhead transportation

The new numerical approach for analysis of the warhead transportations is suggested.This approach allows to control the warhead operability before its experimental analysis.The approach is implemented by the adequate models for the software ANSYS.Analysis of the loads at land operations and transportations of the warhead by natural roads,water and aviation allows to obtain the maximal values of loads,which are used in numerical simulations of the warhead.These loads give an opportunity to analyze the operability and the fatigue strength of the cartridge warhead.The numerical simulations of the attachments of the warhead combat elements are performed on the basis of the suggested method.The data of the numerical simulations verifies the operability of the fastener system of the warhead combat elements.

Structure,Adhesion Strength and Corrosion Resistance of Vacuum Arc Multi-Period NbN/Cu Coatings

resistance,and adhesive strength of vacuum-arc multi-period NbN/Cu coatings is studied.It was found that in thin layers(about 8 nm,in a constant rotation mode),regardless of the change in the pressure of the nitrogen atmosphere,a metastableδ-NbN phase forms(cubic crystal lattice of the NaCl type).At a layer thickness of^40 nm or more,a phase composition changes from the metastableδ-NbN to the equilibriumε-NbN phase with a hexagonal crystal lattice.In the presence of theε-NbN phase in the niobium nitride layers,the highest adhesive strength is achieved with a value of LС5=96.5 N.Corrosion resistance tests have shown that for all the studied samples the corrosion process has mainly an anodic reaction.The highest corrosion resistance was shown by coatings obtained at a pressure of 7·10-4 Torr,with the smallest bias potential of-50 V and the smallest layer thickness;with a thickness of such a coating of about 10 microns,its service life in the environment of the formation of chloride ions is about a year.

Improving the Energy Performance of a High-Pressure Hydraulic Turbine by Researching the Flow in the Flow Part

In this study, the goal is to increase the efficiency of a high-pressure hydraulic turbine. The goal is achieved by numerical flow simulation using CFX-TASCflow. This approach reduces costs and time compared to the experimental approach and allows for improving the turbine productivity and its design. The analysis of energy losses in the flow part of the turbine Fr500, as well as the analysis of the influence of the opening of the guide vanes on changes in energy losses. The results showed that the greatest losses occur in the guide vane 3.02% based on the two-dimensional model and 2.5% based on the 3D model, which significantly affects the efficiency. The analysis was carried out using programs for calculating fluid flow in two-dimensional and three-dimensional formulations. With the help of the study, the main energy problem is solved—increasing efficiency.