Water-resistant organic thermoelectric generator with >10μW output

Flexible p–n thermoelectric generator(TEG)technology has rapidly advanced with power enhancement and size reduction.To achieve a stable power supply and highly efficient energy conversion,absolute chemical stability of n-type materials is essential to ensuring large temperature differences between device terminals and ambient stability.With the aim of improving the long-term stability of the n-type operation of carbon nanotubes(CNTs)in air and water,this study uses cationic surfactants,such as octylene-1,8-bis(dimethyldodecylammonium bromide)(12-8-12),a gemini surfactant,to stabilize the nanotubes in a coating,which retains the n-doped state for more than 28 days after exposure to air and water in experiments.TEGs with 10 p-n units of 12-8-12/CNT(n-type)and sodium dodecylbenzene sulfonate/CNT(p-type)layers are manufactured,and their water stability is evaluated.The initial maximum output of 16.1μW(75 K temperature difference)is retained after water immersion for 40 days without using a sealant to prevent TEG module degradation.The excellent stability of these CNT-based TEGs makes them suitable for underwater applications,such as battery-free health monitoring and information gathering systems,and facilitates the development of soft electronics.

Novel protection systems for the improvement in soil and water stability of expansive soil slopes

To improve the soil and water stability of expansive soil slopes and reduce the probability of slope failure,novel protection systems based on polymer waterproof coatings(PWC)were used in this study.Herein,three groups of expansive soil slope model tests were designed to investigate the effects of polyester nonwovens and PWC(P-PWC)composite protection system,three-dimensional vegetation network and PWC(T-PWC)composite protection system,and nonprotection on the soil and water behavior in the slopes under precipitation–evaporation cycles.The results showed that the moisture change of P-PWC and T-PWC composite protected slopes was significantly smaller than that of bare slope,which reduced the sensitivity of slope moisture to environmental changes and improved its stability.The soil temperature of the slope protected by the P-PWC and T-PWC systems at a depth of 70 cm increased by 5.6℃ and 2.7℃,respectively.Using PWC composite protection systems exhibited better thermal storage performance,which could increase the utilization of shallow geothermal resources.Moreover,the maximum average crack widths of the bare slopes were 7.89 and 3.17 times those of the P-PWC and TPWC protected slopes,respectively,and the maximum average crack depths were 6.87 and 3 times those of the P-PWC and T-PWC protected slopes,separately.The PPWC protection system weakened the influence of hydro–thermal coupling on the slopes,inhibited the development of cracks on the slopes,and reduced the soil erosion.The maximum soil erosion of slopes protected by P-PWC and T-PWC systems was 332 and 164 times lower than that of bare slope,respectively.The P-PWC and T-PWC protection systems achieved excellent"anti-seepage and moisture retention"and anti-erosion effects,thus improving the soil and water stability of slopes.These findings can provide important guiding reference for controlling rainwater infiltration and soil erosion in expansive soil slope projects.

Water Stability Improvement of Acid Fine Aggregate-Based Asphalt Concrete

In general,acid aggregates are not used in combination with asphalt concrete because of their poor compatibility with the asphalt binder,which typically results in a scarce water stability of the concrete.In the present study,the feasibility of a new approach based on the combination of acid granite fine aggregate with alkaline limestone coarse aggregate and Portland cement filler has been assessed.The mineral and chemical compositions of these three materials have first been analyzed and compared.Then,the effect of different amounts of Portland cement(0%,25%,50%,75%and 100%of the total filler by weight)on the mechanical performance and water stability of the asphalt concrete has been considered.Asphalt concrete has been designed by using the Marshall method,and the mechanical performance indexes of this material,including the Marshall stability and indirect tensile strength(ITS),have been measured together with the related water stability indexes(namely the Marshall stability(RMS)and tensile strength ratio(TSR)).The results indicate that the alkaline limestone coarse aggregate and Portland cement filler can balance the drawback caused by the acid granite fine aggregate.The asphalt concrete has good mechanical performances and water stability when the amount of common limestone powder filler replaced by cement is not less than 75%.

Preliminary Study on the Effect of Different Ecological Cultivation Modes on the Water Stability of Soil Aggregates in Rubber Based Agroforestry Systems

Rubber trees (Hevea brasiliensis Müll. Arg.) have been commercially cultivated for a century and a half in Asia, particularly in China, and they constitute a common element of plantation ecosystems in tropical regions. Soil health is fundamental to the sustainable development of rubber plantations. The objective of the study is to explore the influence of different complex ecological cultivation modes on the stability of soil aggregates in rubber based agroforestry systems. In this study, the ecological cultivation mode of rubber—Alpinia oxyphylla plantation, the ecological cultivation mode of rubber—Phrynium hainanense plantations, the ecological cultivation mode of rubber—Homalium ceylanicum plantations and monoculture rubber plantations were selected, and the particle size distribution of soil aggregates and their water stability characteristics were analyzed. The soil depth of 0 - 20 cm and 20 - 40 cm was collected for four cultivation modes. Soil was divided into 6 particle levels > 20 cm. soil was divided into 6 particle levels > 5 mm, 2 - 5 mm, 1 - 2 mm, 0.5 - 1 mm, 0.25 - 0.5 mm, and 0.053 - 0.25 mm according to the wet sieve method. The particle size proportion and water stability of soil aggregates were determined by the wet sieve method. The particle size proportion and water stability of soil aggregates under different ecological cultivation modes were analyzed. The results showed that under different ecological cultivation modes in the shallow soil layer (0 - 20 cm), the rubber—Alpinia oxyphylla plantation and the rubber—Phrynium hainanense plantation promoted the development of dominant soil aggregates towards larger size classes, whereas the situation is the opposite for rubber—Homalium ceylanicum plantation. In soil layer (20 - 40 cm), the ecological cultivation mode of rubber—Phrynium hainanense plantation developed the dominant radial level of soil aggregates to the diameter level of large aggregates. Rubber—Alpinia oxyphylla plantation and rubber—Homalium ceylanicum plantation, three indicators, including the water-stable aggregate content R0.25 (>0.25 mm water-stable aggregates), mean weight diameter (MWD), and geometric mean diameter (GMD), were all lower than those in the rubber monoculture mode. However, in the rubber—Phrynium hainanense plantation, the water-stable aggregate content R0.25, mean weight diameter, and geometric mean diameter were higher than in the rubber monoculture mode, although these differences did not reach statistical significance.

Highly defective HKUST-1 with excellent stability and SO_(2) uptake: The hydrophobic armor effect of functionalized ionic liquids

Water stability is one of the most important factors restricting the practical application of metal organic frameworks (MOFs). In this work, wefabricate a highly defective HKUST-1 framework with a mixed valence of CuI/CuIIby mechanical ball milling method. This defective HKUST-1is embellished by functionalized ionic liquids as hydrophobic armor, making the hybrid HIL1@HKUST-1 exhibits outstanding water stability,remarkable SO_(2) adsorption (up to 5.71 mmol g^(-1)), and record-breaking selectivity (1070 for SO_(2)/CO_(2) and 31,515 for SO_(2)/N_(2)) at 25 ℃ and0.1 bar, even in wet conditions.

Formation and Water Stability of Aggregates in Red Soils as Affected by Organic Matter

The water stability of aggregates in various size classes separated from 18 samples of red soils under different managements, and the mechanisms responsible for the formation of water-stable soil aggregates were studied. The results showed that the water stability of soil aggregates declined with increasing size, especially for the low organic matter soils. Organic matter plays a key role in the formation of water-stable soil aggregates. The larger the soil aggregate size, the greater the impact of organic matter on the water stability of soil aggregates. Removal of organic matter markedly disintegrated the large water-stable aggregates (> 2.0 mm) and increased the small ones (< 0.25-0.smm) to some extent, whereas removal of free iron(aluminium) oxides considerably destroyed aggregates of all sizes, especially the < 0.25-0.5 mm classes. The contents of organic matter in water-stable aggregates increased with aggregate sizes. It is concluded from this study that small water-stable aggregates (< 0.25-0.5 mm) were chiefly cemented by Fe and Al oxides whilst the large ones (> 2.0 mm) were mainly glued up by organic matter. Both free oxides and organic matter contribute to the formation and water stability of aggregates in red soils.

Dynamic Study on Water Stability of Soil Structure and Soil Characteristics of Several Types of Soils in Southwest China

Three suborder soils in southwest China were adopted, namely Ustic Vertisol, Stagnic Anthrosol and Ustic Ferrosol, so as to carry out the basic physical and chemical analysis respectively, to design a dynamic measuring method for water stability of soil structure and conduct the comparative study on the quality of the soil structure. The results indicated that （1） The water stability dynamic characteristic of the soil structure could well reflect the maintaining capability of the soil structure as time goes on. （2） The quality of several soil structures in southwest China was sequenced as follows： Stagnic Anthrosols 〉 Ustic Vertisols 〉 Ustic Ferrosols. （3） The water stability of soil structure is very positively correlated with the capillary porosity and the clay particle （D 〈 0.002 mm） content （Co）, but is very negatively correlated with the silt （D is 0.05-0.002 ram） content （Csc）, and （4） The dynamic functional equation of the water stability of soil structure in southwest China was established, so that the water stability characteristics of various soil structures could be quantitatively expressed and the quality of different soil structures can be quantitatively compared from each other.

Design and operation problems related to water curtain system forunderground water-sealed oil storage caverns

The underground water-sealed storage technique is critically important and generally accepted for the national energy strategy in China. Although several small underground water-sealed oil storage caverns have been built in China since the 1970s, there is still a lack of experience for large-volume underground storage in complicated geological conditions. The current design concept of water curtain system and the technical instruction for system operation have limitations in maintaining the stability of surrounding rock mass during the construction of the main storage caverns, as well as the long-term stability. Although several large-scale underground oil storage projects are under construction at present in China, the design concepts and construction methods, especially for the water curtain system, are mainly based on the ideal porosity medium flow theory and the experiences gained from the similar projects overseas. The storage projects currently constructed in China have the specific features such as huge scale, large depth, multiple-level arrangement, high seepage pressure, complicated geological conditions, and high in situ stresses, which are the challenging issues for the stability of the storage caverns. Based on years’ experiences obtained from the first large-scale （millions of cubic meters） underground water-sealed oil storage project in China, some design and operation problems related to water curtain system during project construction are discussed. The drawbacks and merits of the water curtain system are also presented. As an example, the conventional concept of “filling joints with water” is widely used in many cases, as a basic concept for the design of the water curtain system, but it is immature. In this paper, the advantages and disadvantages of the conventional concept are pointed out, with respect to the long-term stability as well as the safety of construction of storage caverns. Finally, new concepts and principles for design and construction of the underground water-sealed oil storage caverns are proposed.

Technology and Practice of Stabiliing Oil Production and Controlling Water Cut in Kalamkas Oilfield in Central Asia

In this paper, by in-depth geological research of Kalamkas Oilfield in Central Asia, the geological body has been re-ascertained; combined with fine study of reservoir engineering, based on the understanding of the distribution of remaining oil horizontal wells have been given full play to stabilizing oil production and controlling water cut, reducing the producing pressure drop, improving well productivity and other advantages, and the development and deployment has been optimized; horizontal wells have been applied to solve problems such as old well casing damages, shutting down wells, low-productivity and low- efficiency wells, and high water cut wells to improve the utilization rate of old wells; through separate layer system improved injection production pattern, adjustment wells have been optimized and deployed, and part measures wells have been preferably selected to tap the residual oil improve the degree of reserves control realize the stabilization of oil production and control of water cut in an old oilfield, and further improve the development effects.

Influence of Water Stability on Bond Performance Between Magnesium Phosphate Cement Mortar and Steel Fibre

The fibre pullout test was conducted to investigate the influence of the water stability on the bond behaviour between the Magnesium phosphate cement(MPC)matrix and the steel fibre.The composition of the MPC-matrix and the immersion age of the specimens are experimentally investigated.The average bond strength and the pullout energy are investigated by analysing the experimental results.In addition,the microscopic characteristics of the interface transition zone are investigated using scanning electron microscopy(SEM).The experimental results showed that the bond performance between the MPC-matrix and the steel fibre decreased significantly with the increase of the duration of immersion in water.The average bond strength between the steel fibre and the MPC-matrix reduced by more than 50%when the specimens were immersed in the water for 28 days.The effect of the water on the interface between the steel fibre and the MPC-matrix was found to be more significant compared to the composition of the MPC-matrix.In addition,the MgO-KH2PO4 mole ratio of the MPC significantly influenced the water stability of the interface zone between the steel fibre and MPC-matrix.

Estimation of the Volga-Caspian Water Ecosystems Stability under the Possible Climate Change and Anthropogenic Load

In this article, possible consequences of the Volga-Caspian water ecosystems change as a result of climatic changes are stated according to the data scenarios of Worldwide Meteorological Organization.

The technology and practice of water saving at Baosteel

With the development of the production scale and the increasing of the process technologies and facilities,product quality and the requirement of water supply continuously put forward new requirements to water treatment technology.The practice of the water saving technology should ensure the safe of water using and the innovation of technique data.Especially the stabilization of water quality should also meet the production at full capacity,reduce equipment failure rate and maintain the sustainable development under the condition of the minimal resource consumption.This article describes the practice of Baosteel saving technology,water-saving ideas from the system to start,according to Baosteel raw water intake requirements and process water and drainage characteristics,water and salt water tidal according to changes in the Yangtze River and the Yangtze River upstream and downstream trends in water discharge on water quality factors,established the electrical conductivity,chloride ion indicators for the control of the Yangtze River water,the implementation of 'avoid salt build light' water at the same time,combined with the actual situation of water pollution in the Yangtze River,the use of force coefficient correlation theory,the implementation of 'avoid taking clear pollution' to ensure the quality of raw water intake. System and cascade utilization of water,process water,based on whole plant water balance testing, analysis,technical parameters of the system and processes the user running the pressure balance pipe network,and implemented a stabilization system to adjust water pressure,reducing the water supply network systemwater loss;application of electrochemical principles,the implementation of the protection of underground pipes Baosteel,implemented a water use,steps to use,the operating mode of water supply in series to increase water reuse,reduce wastewater discharge system. Water quality stability and water-saving in the process;carry out water quality stability technology in the different complicated processes of the steel industry;apply the environmental protection and water quality, sterilization,non-phosphorus and low phosphorus technologies which are suitable for high concentration of circulating water.By these technologies,we achieved the water-saving in the process in different seasons and solved the technical problems affecting production such as equipment corrosion,scaling and the formation of the water quality proprietary technology under the conditions of high heat load production as well. The use of water ecological conservation and biological treatment technology:the implementation of the reservoir to the ecological technology is characterized by food chain and wetland environmental technology characterized by plants chain.Reservoir ecological management techniques in the use of natural conditions, wind direction,temperature,light and fish biomass in the reservoir water level regulation of balance and combination of organic,control and resolve the reservoirs in spring and summer algae problems and water quality changes rot of the 'fresh' operating problems.The artificial wetland technology develops a new way for metallurgical plants' wastewater treatment.All the measures by the implementation of water to create the conditions for the system to achieve the water target of constant innovation,reaching the advanced level of iron and steel enterprises.

Influence of Hydrodynamic Pore Pressure Damage on the Performance of Hot-Mixed Renewable Asphalt Mixture

For evaluating the water stability of hot-mixed renewable asphalt mixture(HRM),the traditional methods are all tested under still water conditions.Except for damage in still water conditions,the hydrodynamic pore pressure generated by the tire driving on the surface water has a great impact.Thus,the RAP contents of the HRMs were designed at 0%,30%,45%and 60%with AC-25 gradation.Then,the self-designed evaluation methods of water stability and dynamic modulus were studied.Finally,the mechanism of the influence of hydrodynamic pore pressure damage on HRMs was studied.The results show that the water stability of HRM containing 30%RAP is equivalent to that of 45%RAP,and the water stability of HRM containing 60%RAP decreases significantly.The Contabro test after MIST treatment can be used as an evaluation method for hydrodynamic pore pressure damage on HRM.Low-speed,heavy-load traffic and larger RAP content have greater damage to the mixture after hydrodynamic pore pressure damage.The performance differences between the aged bitumen and pure bitumen,as well as the aged minerals and new minerals,are continuing to be enlarged in hydrodynamic pore pressure conditions,finally affecting the water stability and dynamic modulus of the HRMs.

Chemical characteristics and water stability evaluation of groundwater in the CKDu Zone of Sri Lanka

Groundwater is the main source of drinking water for the rural population in the chronic kidney disease of unknown etiology(CKDu)zone of the North Central Province(NCP)in Sri Lanka.In this study,a total of 334 groundwater samples(311 dug wells,21 tube wells and 2 springs)during the wet season from two aquifers in the NCP were collected,and inves-tigated their chemical characteristics and evaluate their water quality,including ground-water chemistry,main ion sources,the corrosion and scaling potential of groundwater.The results showed that the two hydrochemical types of groundwater in the NCP were mainly of the Ca-HCO_(3),Na·Ca-HCO_(3)types,with the main HCO_(3)−,Na^(+)and Ca^(2+)ions in both types of groundwater originating from silicate and evaporite salt dissolution and influenced by alternating cation adsorption,while the presence of NO_(3)−was mainly anthropogenic.Eval-uation ofwater stability using namely Langelier saturation index(LSI),Ryznar stability index(RSI),Puckorius scaling index(PSI)and Larson-Skold index(LS),indicated that most ground-water presents corrosion potential and has corrosion behavior tendency of metals to some degrees.The water quality of Polonnaruwa was better than that of Anuradhapura in the NCP,and when the groundwater was worse than the“good”grade,which must be properly treated before it is used as drinking water.

Development and Field Application of Phosphogypsum-Based Soil Subgrade Stabilizers

A phosphogypsum-based subgrade stabilizer(PBSS)was formulated using industrial by-product phosphogypsum(PG),mixed with slag and calcium-silicon-rich active material(GSR).The active powder(AP)was used to modify PBSS,and PBSS-AP was obtained.PBSS and PBSS-AP were each mixed with 10%silty soil,and cement and lime(CAL:5%lime+2%cement)were used as the traditional material for comparative experiments.Samples were cured under standard conditions,and tested for unconfined compressive strength(UCS),water stability,volume expansion,and leachate,to explore the stabilization effect of the three solidified materials on silty soil.The results showed that the comprehensive performance of sility soil mixed with 12%PBSS-AP was the best.The CaO,SiO_(2)and Al_(2)O_(3)provided by PG,Slag and GSR will react with water to form a stable C-S-H gel,which is conducive to stabilizing the soil.Field application results showed that the compaction exceeded 95%,the deflection was 144.9 mm,and UCS was 2.5 MPa after 28 days.These findings indicated that PBSS-AP is an effective stabilizer for subgrade soils.

Irrigation erosion of irrigated soils in the foothills of southern Kazakhstan

Abstract： This paper presented the results from the study of irrigation erosion of irrigated lands in southern Ka- zakhstan. The main purpose of the work is the conservation of the fertility of irrigated soils, and then the soils of the upper, middle and lower sections of the slopes at the experimental site were studied. Based on field investigations, authors studied the water resistance of aggregates of gray-brown soils and light gray soils before and after irrigation and qualitative indicators of changes in physical and chemical properties of structured soils in irrigation were de- termined by conventional methods of soil research. The results indicated that the changes in the physical properties of soils by using polymeric compounds created a fundamentally new opportunity to control water erosion of soils.

Study of the engineering geologic feature of weathering zone of bedrock in 810 producing area of Luling Mine

For a safe extracting of the mine resource of the razor thin capping rock, a study of waterproof, sand prevention, roof fall prevention must be made. As a result, it’s necessary to master the engineering feature of weathering zone of bedrock. According to the lithology appraisal and X diffract analyses, the mineral feature of weathering zone of bedrock in 810 producing area has been studied in this article. By testing the physical mechanics index of weathering zone, we have found out some features of physical mechanic quality. Utilizing the determined result of viscosity index and slaking test, we reach a conclusion of the water stability of weathering zone, that is the weathering zone rock belongs to the type that is easily slaked when encountered water and the water stability is weak.

Effects of the grinding process on the preparation and qualities of CWS

Two different grinding processes were examined to determine the effect grinding has on the quality of a CWS. A series of slurries was prepared from Australian (Au) and Chinese (YZ) coals. Both types of coal were ground by a Chinese (CUMT) and an Australian (JK) grinding process. The performance tests of the prepared CWS showed that fluidity of all slurries was acceptable. The concentration of the CWS from YZ coal ground by the CUMT grinding process was higher than when the JK grinding process was used. The highest concentration was 70.14% in this case. The concentration of the CWS prepared from Au coal by the JK grinding process was higher than when the CUMT grinding process was used. The highest con- centration in this case was 70.97%. These differences are caused by the particle size distribution devel- oped during the different grinding processes.

A topology approach to overcome the pore size/volume trade-offs for autonomous indoor humidity control

Autonomous indoor humidity control is gaining more and more attention but is limited by the trade-offs among pore volume,pore size and water stability of water adsorbents.We solve this problem by using a unique coordination network topology combined with hydrolytically stable M(Ⅲ)carboxylate clusters.By extending the ligand length from 9.0 to 11.2 and 13.7?,the pore volume significantly increases from 0.99 to 1.40 and 1.78 cm^(3)g^(-1),which proportionally increases the saturated water adsorption capacity.Meanwhile,the pore size slightly increases from 10.4 to 11.0 and 13.5A,which restricts the isotherm inflection pressure and hysteresis width to meet the requirement of indoor humidity control.Large single-crystals suitable for Xray diffraction studies were obtained by using Fe(Ⅲ)salts,while isostructural frameworks with sufficiently high water stabilities were synthesized by using Cr(Ⅲ)salts,which offer record working capacity of 0.90 and 1.10 g g^(-1)for indoor humidity control.

The stability of MOFs in aqueous solutions——research progress and prospects

Metal-organic frameworks(MOFs)are favored in the fields of adsorption,separation,catalysis,electrochemistry,and magnetism due to their advantages of large specific surface area,high porosity,controllable pore size adjustment,and dispersion of metal active sites.The application of MOFs involves multiple fields,which requires that MOFs have good water stability,as gaseous and liquid water inevitably exist in industrial processes.In this paper,the research status of the stability of MOFs in aqueous solutions was reviewed in recent years,including the design and synthesis,the influencing factors,and the applications of MOFs in water stability.