Discovery of the Significant Impacts of Swell Propagation on Global Wave Climate Change

This study compared the differences in the wave climate in the South China Sea and North Indian Ocean under these two datasets:ERA-40 wave reanalysis and Mei’s hindcast wave data.In the numerical calculation of regional ocean waves,the wave climate characteristics exhibited significant bias if the influence of external swells(swells from afar)was not fully considered,which may provide an incorrect basis for global climate change analysis.1)The trends of the significant wave height(SWH)obtained from the two datasets showed significant differences,such as those of the Bay of Bengal and the Java Sea in June-July-August.For the past 45 years,SWH from ERA-40(SWH-ERA)exhibited a significant annual increase in low-latitude waters of the North Indian Ocean(0.2-0.6 cm yr^(-1))and South China Sea(0.2-0.8 cm yr^(-1)).2)In the Bay of Bengal,the SWH-ERA in each month was generally 0.5 m higher than the SWH from Mei’s hindcast wave data(SWH-Mei)and can reach 1.0 m higher in some months.3)In the Bay of Bengal,SWH-ERA and SWH-Mei increased significantly at annual rates of 0.13 and 0.27 cm yr^(-1),respectively.This increasing trend was mainly reflected after 1978.SWH-ERA showed a trough in 1975(1.33 m)and a crest in 1992(1.83 m),which were not reflected in SWH-Mei.

Targeting harmful effects of non-excitatory amino acids as an alternative therapeutic strategy to reduce ischemic damage

The involvement of the excitatory amino acids glutamate and aspartate in ce rebral ischemia and excitotoxicity is well-documented.Nevertheless,the role of non-excitatory amino acids in brain damage following a stroke or brain trauma remains largely understudied.The release of amino acids by necrotic cells in the ischemic core may contribute to the expansion of the penumbra.Our findings indicated that the reversible loss of field excitato ry postsynaptic potentials caused by transient hypoxia became irreversible when exposed to a mixture of just four non-excitatory amino acids(L-alanine,glycine,L-glutamine,and L-serine)at their plasma concentrations.These amino acids induce swelling in the somas of neurons and astrocytes during hypoxia,along with permanent dendritic damage mediated by N-methyl-D-aspartate receptors.Blocking N-methyl-D-aspartate receptors prevented neuronal damage in the presence of these amino acids during hypoxia.It is likely that astroglial swelling caused by the accumulation of these amino acids via the alanine-serine-cysteine transporter 2 exchanger and system N transporters activates volume-regulated anion channels,leading to the release of excitotoxins and subsequent neuronal damage through N-methyl-D-aspartate receptor activation.Thus,previously unrecognized mechanisms involving non-excitatory amino acids may contribute to the progression and expansion of brain injury in neurological emergencies such as stroke and traumatic brain injury.Understanding these pathways co uld highlight new therapeutic targets to mitigate brain injury.

Maxi-anion channel as a candidate pathway for osmosensitive ATP release from mouse astrocytes in primary culture

In the present study, we aimed to evaluate the pathways contributing to ATP release from mouse astrocytes during hypoosmotic stress. We first examined the expression of mRNAs for proteins constituting possible ATP- releasing pathways that have been suggested over the past several years. In RT-PCR analysis using both control and osmotically swollen astrocytes, amplification of cDNA fragments of expected size was seen for connexins （Cx32, Cx37, Cx43）, pannexin 1 （Pxl）, the P2X7 receptor, MRP1 and MDR1, but not CFTR. Inhibitors of exocytotic vesicular release, gap junction hemi-channels, CFTR, MRP1, MDR1, the P2X7 receptor, and volume-sensitive outwardly rectifying chloride channels had no significant effects on the massive ATP release from astrocytes. In contrast, the hypotonicity-induced ATP release from astrocytes was most effectively inhibited by gadolinium （50 μM）, an inhibitor of the maxi-anion channel, which has recently been shown to serve as a pathway for ATP release from several other cell types. Thus, we propose that the maxi-anion channel constitutes a major pathway for swelling-induced ATP release from cultured mouse astrocytes as well.

African eggplant(Solanum anguivi Lam.)fruit with bioactive polyphenolic compounds exerts in vitro antioxidant properties and inhibits Ca^(2+)-induced mitochondrial swelling

Objective:To evaluate the antioxidant and radical scavenging activities of Solanum anguivi fruit(SAG)and its possible effect on mitochondrial permeability transition pore as well as mitochondrial membrane potential(△Ψ_m)isolated from rat liver.Methods:Antioxidant activity of SAG was assayed by using 2,2-diphenyl-1-picrylhydrazyl(DPPH),reducing power,iron chelation and ability to inhibit lipid peroxidation in both liver and brain homogenate of rats.Also,the effect of SAG on mitochondrial membrane potential and mitochondrial swelling were determined.Identification and quantification of bioactive polyphenolics was done by HPLC-DAD.Results:SAG exhibited potent and concentration dependent free radical-scavenging activity(IC_(50)/DPPH=275.03±7.8μg/mL).Reductive and iron chelation abilities also increase with increase in SAG concentration.SAG also inhibited peroxidation of cerebral and hepatic lipids subjected to iron oxidative assault.SAG protected against Ca^(2+)(110μmol/L)-induced mitochondrial swelling and maintained the△Ψ_m.HPLC analysis revealed the presence of gallic acid[(17.54±0.04)mg/g],chlorogenic acid(21.90±0.02 mg/g),caffeic acid(16.64±0.01 mg/g).rutin[(14.71±0.03)mg/g]and quercetin[(7.39±0.05)mg/g].Conclusions:These effects could be attributed to the bioactive polyphenolic compounds present in the extract.Our results suggest that SAG extract is a potential source of natural antioxidants that may be used not only in pharmaceutical and food industry but also in the treatment of diseases associated with oxidative stress.

A new model to estimate significant wave heights with ERS-1/2 scatterometer data

A new model is proposed to estimate the significant wave heights with ERS-1/2 scatterometer data. The results show that the relationship between wave parameters and radar backscattering cross section is similar to that between wind and the radar backscattering cross section. Therefore, the relationship between significant wave height and the radar backscattering cross section is established with a neural network algorithm, which is, if the average wave period is ≤7s, the root mean square of significant wave height retrieved from ERS-1/2 data is 0.51 m, or 0.72 m if it is >7s otherwise.

Synthesis of ITQ-2 Zeolites and Catalytic Performance in n-Dodecane Cracking

ITQ-2 zeolites were prepared by sequential alkali-swelling and ultrasonic-delamination of precursor MCM-22 and characterized by X-ray powder diffraction, scanning electron microscopy, nitrogen adsorption-desorption, ammonia temperature-programmed desorption and in-situ Fourier-transform infrared spectroscopy. The delamination induced a change in the morphology of ITQ-2 zeolites from aggregated thin platelets to scattered platelets, together with a significant increase in external specific surface area, which reached a plateau at the ultrasonic treatment time of 3 h. The catalytic cracking of n-dodecane over ITQ-2 zeolites was evaluated with ITQ-2 coated on the inside wall of a tubular reactor at 550 ℃ and 4 MPa. The sample obtained by ultrasonic treatment of 3 h （ITQ-2-3） gave the highest initial conversion of n-dodecane, whereas those of 5 h and I h gave the conversion even lower than MCM-22, which was in agreement with the trend of the ratio of strong Lewis acid to the total acid amount. Although the amount of cokes deposited on ITQ-2-3 was larger than that on MCM-22, the former deactivated slowly, suggesting that a large external specific surface area benefits the stability of zeolite coatings,

Measurement of Crystallinity of Acrylic Copolymer by Swelling Differential Scanning Calorimetry

In this paper the measurement of crystallinity(C)ofacrylic copolymer(PAC),by Swelling Differential Scan-ning Calorimetry(SDSC)is discussed.Common DSC isonly used for measuring the crystallinity of polymers withmelting point,(T_m),below their decomposition temper-ature,(T_d).As temperature rises,polymers with swell-ing agent added become swollen and dissolved,goingthrough whole process of breaking solid structures.Thus,SDSC makes it possible to measure the crystallini-ty of polymers even with T_d below T_m.But the C mea-sured by WAXD and the total endothermal melting(swelling)heat in SDSC thermograms,(△H_l),are notlinearly correlated.It has been found that,instead of the△H_l,△H_l’obtained from the △H_l by subtracting the en-dothermal heat,△H_l,and the C measured by WAXDare linearly correlated.On the basis of this linear rela-tion,the unknown C of another PAC sample is measuredby SDSC.The result is in good accordance with thatmeasured by WAXD.

Sonographic differentiation of diffuse liver cancer from portal cirrhosis

Objective: To differentiate diffuse liver cancer from portal cirrhosis by using ultrasonography. Methods: We analyzed the sonographic images of 15 patients with diffuse liver cancer and 30 patients with portal cirrhosis. Results: The patients with diffuse liver cancer showed enlarged liver and obvious echo of nodules. The rate of portal embolism and swelling of lymph nodes a- round the porta hepatis was high. The patients with portal cirrhosis showed diminished liver and the obvi- ous echo of fiber proliferation. The rates of spleen enlargement and ascites as well as gallbladder edema were high. Conclusions: To identify sonographic characteristics inside and outside of the liver. It is helpful in diffe- rentiating diffuse liver cancer from portal cirrhosis. The sonographic characteristics inside the liver in- clude surface and size, node echo, echo of fibrous tissue hyperplasia. They are difficult to identify when diffuse liver cancer merges with considerable cirrho- sis. The acoustic image characteristics of the two di- seases overlap. Hence attention should be paid to the size of the liver, proliferation of cells of diffuse liver carcinoma. In sonographic characteristics outside the liver, embolism of the portal vein and swelling of lymph nodes in the porta hepatis are particularly use- ful to identify diffuse liver cancer or diffuse liver cancer combined with liver cirrhosis in particular.

Therapeutic effect of neurogrowth factor in the treatment of gingival pain and swelling in patients with dental pulp necrosis after root canal therapy

Objective: To explore the clinical efficacy of neurogrowth factor in the treatment of gingival pain and swelling in patients with dental pulp necrosis after root canal therapy and the effect on the serum inflammatory cytokines. Methods: A total of 156 patients with gingival pain and swelling after root canal therapy due to dental pulp necrosis were included in the study and randomized into the control group (n=78) and teh treatment group (n=78). The patients in the control group were given metronidazole tablets. On the above basis, the patients in the treatment group were given local injection of neurogrowth factors. 10-day treatment was regarded as one course, and the patients were continuously treated for 2 courses. The improvement of clinical symptoms before and after treatment in the two groups was evaluated. Gingival sulcus index and serum inflammatory cytokines before and after treatment in the two groups were detected and compared. Results: When compared with before treatment, the periodontal soft tissue swelling, tooth mobility, and periapical pain scores after treatment in the two groups were significantly reduced, and those in the treatment group were significantly lower than those in the control group. When compared with before treatment, the gingival sulcus bleeding index 1 and 2 courses after treatment in the two groups was significantly reduced, and that 2 courses after treatment was significantly lower than that after 1 course treatment. The gingival sulcus bleeding index 1 and 2 courses after treatment in the treatment group was significantly lower than that in the control group. When compared with before treatment, the serum IL-8 and IL-6 levels after treatment in the two groups, and TNF-α level after treatment in the treatment group were significantly reduced, and the above indicators in the treatment group were significantly lower than those in the control group. Conclusions: The neurogrowth factors in the treatment of gingival pain and swelling in patients with dental pulp necrosis after root canal therapy can effectively improve the clinical symptoms, and inhibit the inflammatory reaction, with a significant efficacy.

First-principles Investigation of Vacancy and Self-interstitial Atom Formation Energy at Grain Boundary in Tungsten

Materials served in nuclear energy systems usually expose to high irradiation doses of particles.Projectile particles lead to creations of a large numbers of vacancies(Vs)and self-interstitial atoms(SIAs)in materials.The SIAs may gather to form dislocation loops and stacking-fault tetrahedrons,and the Vs usually gather to form voids.These defects contribute to material swelling,hardening,amorphization and embrittlement,and may accelerate material failure under irradiation[1].Extensive experimental results demonstrated that nano-crystalline materials generally showed good radiation resistance than common poly-crystalline materials because there existed a high fraction of grain boundaries(GBs)in nano-crystalline materials[2].

First-principles Investigation of Vacancy and Self-interstitial Atom Segregations at Grain Boundaries in Tungsten

Materials served in nuclear energy systems usually expose to high irradiation doses of particles.Projectile particles lead to creations of a large numbers of vacancies(Vs)and self-interstitial atoms(SIAs)in materials.The SIAs may gather to form dislocation loops and stacking-fault tetrahedrons,and the Vs usually gather to form voids.These defects contribute to material swelling,hardening,amorphization and embrittlement,and may accelerate material failure under irradiation[1].As recombination center of Vs and SIAs,grain boundaries(GBs)are able to enhance the radiation resistance of materials[2].However,experimental investigation show that point defects sink strengths might depend on GB structures.The vacancy sink efficiency of the twin boundaryΣ3(110)[111]is significantly lower than that of other GBs[3−5].

Synthetic polymers:A review of applications in drilling fluids

With the growth of deep drilling and the complexity of the well profile,the requirements for a more complete and efficient exploitation of productive formations increase,which increases the risk of various complications.Currently,reagents based on modified natural polymers(which are naturally occurring compounds)and synthetic polymers(SPs)which are polymeric compounds created industrially,are widely used to prevent emerging complications in the drilling process.However,compared to modified natural polymers,SPs form a family of high-molecular-weight compounds that are fully synthesized by undergoing chemical polymerization reactions.SPs provide substantial flexibility in their design.Moreover,their size and chemical composition can be adjusted to provide properties for nearly all the functional objectives of drilling fluids.They can be classified based on chemical ingredients,type of reaction,and their responses to heating.However,some of SPs,due to their structural characteristics,have a high cost,a poor temperature and salt resistance in drilling fluids,and degradation begins when the temperature reaches 130℃.These drawbacks prevent SP use in some medium and deep wells.Thus,this review addresses the historical development,the characteristics,manufacturing methods,classification,and the applications of SPs in drilling fluids.The contributions of SPs as additives to drilling fluids to enhance rheology,filtrate generation,carrying of cuttings,fluid lubricity,and clay/shale stability are explained in detail.The mechanisms,impacts,and advances achieved when SPs are added to drilling fluids are also described.The typical challenges encountered by SPs when deployed in drilling fluids and their advantages and drawbacks are also discussed.Economic issues also impact the applications of SPs in drilling fluids.Consequently,the cost of the most relevant SPs,and the monomers used in their synthesis,are assessed.Environmental impacts of SPs when deployed in drilling fluids,and their manufacturing processes are identified,together with advances in SP-treatment methods aimed at reducing those impacts.Recommendations for required future research addressing SP property and performance gaps are provided.

Microstructure and water-swelling mechanism of red-bed mudstone in the Xining region,Northeastern Tibetan Plateau

This paper examines the effect of the microstructure and electrical conductivity(EC)on the swelling ratio and pressure in red-bed mudstone sampled from arid areas in the Xining region in the northeastern Tibetan Plateau.A series of laboratory tests,including swelling experiments,X-ray diffraction(XRD),and scanning electron microscope(SEM),was carried out for mechanical and microstructural analysis.The coupled influence of the EC and microstructural parameters on the expansion ratio and pressure was investigated,and the weight coefficients were discussed by the entropy weight method.The results revealed an increasing exponential trend in EC,and the maximum swelling speed occurred at an EC of approximately 10 μS/cm.In addition,a method for predicting the expansion potential is proposed based on the microstructure,and its reliability is verified by comparing with swelling experimental results.In addition,according to the image analysis results,the ranges of the change in the clay minerals content(CMC),the fractal dimension(FD),the average diameter(AD)of pores,and the plane porosity(PP)are 23.75%-53%,1.08-1.17,7.53-22.45 mm,and 0.62%-1.25%,respectively.Moreover,mudstone swelling is negatively correlated with the plane porosity,fractal dimension and average diameter and is linearly correlated with the clay mineral content.Furthermore,the weight values prove that the microstructural characteristics,including FD,AD,and PP,are the main factors influencing the expansion properties of red-bed mudstones in the Xining region.Based on the combination of macro and micro-analyses,a quantitative analysis of the swelling process of mudstones can provide a better reference for understanding the mechanism of expansion behavior.

Effect of non-uniform swelling on coal multiphysics during gas injection: The triangle approach

In current dual porosity/permeability models,there exists a fundamental assumption that the adsorption-induced swelling is distributed uniformly within the representative elementary volume (REV),irrespective of its internal structures and transient processes.However,both internal structures and transient processes can lead to the non-uniform swelling.In this study,we hypothesize that the non-uniform swelling is responsible for why coal permeability in experimental measurements is not only controlled by the effective stress but also is affected by the adsorption-induced swelling.We propose a concept of the swelling triangle composed of swelling paths to characterize the evolution of the non-uniform swelling and serve as a core link in coupled multiphysics.A swelling path is determined by a dimensionless volumetric ratio and a dimensionless swelling ratio.Different swelling paths have the same start and end point,and each swelling path represents a unique swelling case.The swelling path as the diagonal of the triangle represents the case of the uniform swelling while that as the two perpendicular boundaries represents the case of the localized swelling.The paths of all intermediate cases populate inside the triangle.The corresponding relations between the swelling path and the response of coal multiphysics are established by a non-uniform swelling coefficient.We define this method as the triangle approach and corresponding models as swelling path-based ones.The proposed concept and models are verified against a long-term experimental measurement of permeability and strains under constant effective stress.Our results demonstrate that during gas injection,coal multiphysics responses have a close dependence on the swelling path,and that in both future experiments and field predictions,this dependence must be considered.

Effect of slake durability on time dependent swelling behavior of red-bed siltstone in Sichuan Basin

The swelling behavior of red-bed rocks is a significant factor in the abnormal uplift of subgrades for high-speed railways constructed on the red stratum in the Sichuan Basin,China.The prime objective of this paper is to investigate the impact of mineralogical composition,moisture content,and overburden load on the time-dependent unconfined and oedometric swelling behavior of red-bed siltstone in the context of differences in the slake durability.Twenty samples were prepared for the swelling test,with eleven used for the unconfined swelling and slake index tests and nine for the oedometric swelling test.The temporal dependency of swelling is characterized by the viscosity coefficient of water absorption in a proposed swelling model.Results indicate that the swelling deformation of red-bed rocks is due to a combination of hydration swelling within the rock matrix and crack expansion caused by air breakage.In the unconfined swelling test,the final axial swelling strain of red-bed rocks decreases linearly with increasing slake index,while the viscosity coefficient increases exponentially with the slake index.In the oedometric swelling test,red-bed rocks with lower slake durability show greater sensitivity to lateral constraint and overburden load compared to those with higher slake durability.

At-rest lateral earth pressure of compacted expansive soils:Experimental investigations and prediction approach

This paper presents experimental studies on a compacted expansive soil,from Nanyang,China for investigating the at-rest lateral earth pressureσL of expansive soils.The key studies include(i)relationships between theσL and the vertical stressσV during soaking and consolidation,(ii)the influences of initial dry densityρd0 and moisture content w 0 on the vertical and lateral swelling pressures at no swelling strain(i.e.σV0 andσL0),and(iii)evolution of theσL during five long-term wetting-drying cycles.Experimental results demonstrated that the post-soakingσL-σV relationships are piecewise linear and their slopes in the passive state(σL>σV)and active state(σL<σV)are similar to that of the consolidationσL-σV relationships in the normal-and over-consolidated states,respectively.The soakingσL-σV relationships converge to the consolidationσL-σV relationships at a thresholdσV where the interparticle swelling is restrained.TheσL0 andσV0 increase monotonically withρd0;however,they show increasing-then-decreasing trends with the w 0.The extent of compaction-induced swelling anisotropy,which is evaluated byσL0/σV0,reduces with an increase in the compaction energy and molding water content.TheσL reduces over moisture cycles and the stress relaxation in theσL during soaking is observed.An approach was developed to predict the at-rest soakingσL-σV relationships,which requires conventional consolidation and shear strength properties and one measurement of theσL-σV relationships during soaking.The proposed approach was validated using the results of three different expansive soils available in the literature.

Molecular Investigation of Theileria in Ixodid Ticks from Changzhi,Shanxi Province,China

Theileria is a tick-borne intracellular protozoan that typically parasitizes erythrocytes,lymphocytes,and macrophages and causes acute clinical symptoms in host animals,including high fever,anemia,jaundice,and swelling of superficial lymph nodes[1].Theileriosis can lead to high mortality rates,and its rising global prevalence has resulted in significant economic losses to livestock husbandry and the national economy[2].

Swelling pressure evolution characterization of strong expansive soil considering the influence of reserved expansion deformation

Numerous engineering cases have demonstrated that the expansive soil channel slope remains susceptible to damage with the implementation of a rigid or closed protective structure. It is common for the protective structure to experience bulging failure due to excessive swelling pressure. To investigate the swelling pressure properties of expansive soil, the constant volume test was employed to study the influence of water content and reserved expansion deformation on the characteristics of swelling pressure in strong expansive soils, and also to explore the evolution mechanism of the swelling pressure. The findings demonstrate that the swelling pressure-time curve can be classified into swelling pressure-time softening and swelling pressure-time stability type. The swelling pressuretime curve of the specimen with low water content is the swelling pressure-time softening type, and the softening level will be weakened with increasing reserved expansion deformation. Besides, the maximum swelling pressure Psmax decreases with increasing water content and reserved expansion deformation, especially for expansion ratio η from 24% to 37%. The reserved deformation has little effect on reducing Psmax when it is beyond 7% of the expansion rate. The specimen with low water content has a more homogeneous structure due to the significant expansion-filling effect, and the fracture and reorganization of the aggregates in the specimens with low water content cause the swelling pressure-time softening behavior. In addition, the proposed swelling pressure-time curve prediction model has a good prediction on the test results. If necessary, a deformation space of about 7% expansion rate is recommended to be reserved in the engineering to reduce the swelling pressure except for keeping a stable water content.

Swelling behaviors of heterogeneous red-bed mudstone subjected to different vertical stresses

In this study,the axial swelling strain of red-bed mudstone under different vertical stresses are measured by swell-under-load method,and the microstructure of mudstone after hygroscopic swelling is studied by mercury intrusion porosimetry(MIP).The weakening coefficient and Weibull distribution function are introduced into the coupling model of mudstone moisture diffusion-swelling deformation-fracture based on finite-discrete element method(FDEM).The weakening effect of moisture on mudstone's mechanical parameters,as well as the heterogeneity of swelling deformation and stress distribution,is considered.The microcrack behavior and energy evolution of mudstone during hygroscopic swelling deformation under different vertical stresses are studied.The results show that the axial swelling strain of mudstone decreases with increase of the vertical stress.At low vertical stresses,moisture absorption in mudstone leads to formation of cracks caused by hydration-induced expansion.Under high vertical stresses,a muddy sealing zone forms on the mudstone surface,preventing further water infiltration.The simulation results of mudstone swelling deformation also demonstrate that it involves both swelling of the mudstone matrix and swelling caused by crack expansion.Notably,crack expansion plays a dominant role in mudstone swelling.With increasing vertical stress,the cracks in mudstone change from tensile cracks to shear cracks,resulting in a significant reduction in the total number of cracks.While the evolution of mudstone kinetic energy shows similarities under different vertical stresses,the evolution of strain energy varies significantly due to the presence of different types of cracks in the mudstone.The findings provide a theoretical basis for understanding the hygroscopic swelling deformation mechanism of red-bed mudstone at various depths.

Effect of drying cracks on swelling and self-healing of bentonite-sand blocks used as engineered barriers for radioactive waste disposal

Experiments were conducted to evaluate the healing of drying cracks in air-dried bentonite-sand blocks after hydration and swelling in groundwater,providing justifications to simplify the protection of blocks prior to installation in a high-level radioactive waste repository.Synthetic groundwater was prepared to represent the geochemistry of Beishan groundwater,and was used to hydrate the blocks during the swelling pressure and swelling strain measurements,as Beishan is the most promising site for China's repository.Healing of the surface cracks was recorded by photography,and healing of the internal cracks was visualized by CT images and hydraulic conductivity of air-dried blocks.The results indicate that the maximum swelling pressure and swelling strain are primarily affected by the geochemistry of Beishan groundwater,but not affected by the drying cracks.The maximum swelling pressure and swelling strain of air-dried blocks are comparable to or even higher than the pressure and strain of fresh blocks.The maximum swelling pressure measured in strong(i.e.high ion strength)Beishan groundwater was 44%of the pressure measured in deionized(DI)water,and the maximum swelling strain was reduced to 23%of the strain measured in DI water.Nevertheless,the remained swelling of the blocks hydrated in strong Beishan groundwater was sufficient to heal the surface and internal drying cracks,as demonstrated by the pictures of surface cracks and CT images.The hydraulic conductivity of the air-dried block permeated with strong groundwater was comparable(3.7×higher)to the hydraulic conductivity of the fresh block,indicating the self-healing of drying cracks after hydration and swelling in groundwater.A simplified method of protecting the block with plastic wraps before installation is recommended,since the remained swelling of the block hydrated in Beishan groundwater is sufficient to heal the drying cracks.