Academic literature on the topic 'Wet and Dry cycles'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Wet and Dry cycles.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "Wet and Dry cycles"
1
Ye, Wanjun, Yang Bai, Chenyang Cui, and Xu Duan. "Deterioration of the Internal Structure of Loess under Dry-Wet Cycles." Advances in Civil Engineering 2020 (July 16, 2020): 1–17. http://dx.doi.org/10.1155/2020/8881423.
Full textAbstract:
To understand the structural damage evolution process of loess under the action of dry-wet cycles, a triaxial test of a dry-wet cycle was performed by considering three influencing factors: initial moisture content, amplitude of the dry-wet cycle, and number of dry-wet cycles. The stress-strain curves of undisturbed loess samples at different cycling times vary under different compacted loess cycles. Under the same axial strain, the stress value of the undisturbed loess is higher than that of the loess sample after a dry-wet cycle, indicating that such cycle can reduce the strength of loess. As the number and amplitude of dry-wet cycles increase, the shear strength of the loess sample and the value of cohesion (c) of the strength index gradually decrease, and the amplitude gradually decreases. With an increase in the number and amplitude of dry-wet cycles, the change in the internal friction angle of the strength index is inevident, indicating that the effect of dry-wet cycles on the internal friction angle of loess is insignificant. Computed tomography (CT) scan experiments were also conducted to obtain the evolution of loess cracks before and after a dry-wet cycle. Studies have shown that as the number and amplitude of dry-wet cycles increase, the mean (ME) value of CT decreases, the standard deviation (SD) value increases, and the ME value is obtained during the initial stage of a dry-wet cycle. Meanwhile, the decreasing trend of ME and the increasing trend of SD values are most evident during the period of a dry-wet cycle. In conclusion, dry-wet cycles promote the development of cracks.
2
Liu, Kai, Tianfeng Gu, Xingang Wang, and Jiading Wang. "Time-Dependence of the Mechanical Behavior of Loess after Dry-Wet Cycles." Applied Sciences 12, no. 3 (January 24, 2022): 1212. http://dx.doi.org/10.3390/app12031212.
Full textAbstract:
The structure, time-dependent mechanical deformation, and strength characteristics of loess, which is loose and porous with well-developed vertical joints, are greatly affected by the dry-wet cycles, which are attributed to periodic artificial irrigation, rainfall, and water evaporation. To better understand the creep characteristics of loess under the effect of dry-wet cycles, Q2 loess samples obtained from the South Jingyang County, China, were subjected to different dry-wet cycles (0, 5, 10, 15, 20) and sheared in triaxial creep tests. The experimental results revealed that: firstly, the maximum value of the deviatoric stress corresponding to creep failure gradually decreases with an increase in the dry-wet cycles. Secondly, the long-term strength of the loess after dry-wet cycles were obtained through the Isochronous Curve Method. It is found that the long-term strength and the number of dry-wet cycles showed an exponential decreasing relationship. In addition, the creep damage mechanism of loess due to dry-wet cycles is proposed. This study may provide the basis for understanding the mechanical behavior of the loess under the effect of dry-wet cycles, as well as guidelines for the prevention and prediction of loess landslide stability.
3
Liang-Xiao, Xiong, and Song Xiao-Gang. "Mechanical Properties of Cement Mortar after Dry–Wet Cycles and High Temperature." Civil Engineering Journal 6, no. 5 (May 1, 2020): 1031–38. http://dx.doi.org/10.28991/cej-2020-03091526.
Full textAbstract:
The dry–wet cycle and high temperature exposure are important factors affecting the normal use and durability of concrete structures. The objective of this work is to investigate the mechanical properties of cement mortar specimens after combinations of dry–wet cycles and high temperature exposures, uniaxial compressive tests on cement mortar specimens were carried out under the following two sets of conditions: (1) high temperature treatment followed by a dry–wet cycle and (2) a dry–wet cycle followed by high temperature treatment. The results show that the compressive strength of specimens increases with the number of dry–wet cycles. After a dry–wet cycle and then a high temperature treatment procedure, the compressive strength of a specimen will first decrease and then increase with the number of dry–wet cycles. The strain at the peak stress of cement mortar decreases as the number of dry–wet cycles increases. At present, there are few research results about the mechanical properties of concrete first after combinations of dry–wet cycles and high temperature exposures. The work in this paper can enrich the results in this area.
4
Zhu, Rui, Ying-hao Huang, Zhu Song, and Feng Zhou. "Volume Changes and Mechanical Properties of Expansive Mudstone below Canals under Wet-Dry/Wet-Dry-Freeze-Thaw Cycles." Advances in Civil Engineering 2021 (June 5, 2021): 1–11. http://dx.doi.org/10.1155/2021/3791692.
Full textAbstract:
The complex environment in northern China is the main reason for degradation of expansive mudstone below the canals, which resulted in instability and damage of canal slopes. In this study, a serial of laboratory tests was conducted to explore the volume changes and mechanical behaviors of expansive mudstone below the canals in Xinjiang. The experimental program includes wet-dry (WD) and wet-dry-freeze-thaw (WDFT) tests, volume measurement, and unconfined compression tests. The test results show that during the WD cycles, the volume changes of expansive mudstones with a higher dry range would be more significant. The freeze-thaw process in the WDFT cycles resulted in a decrease of volume change ranges when the expansive mudstones had a relatively smaller dry range and a slight increase of volume change ranges when the expansive mudstones had a relatively larger dry range. In the meantime, the stress-strain relationships of expansive mudstones with different dry ranges all presented strain softening under the cycles of WD or WDFT. The first cycle resulted in a significant decrease of failure strength. After seven WD/WDFT cycles, the failure strength of expansive mudstones with different dry ranges decreased by 37.2%∼59.1%. In addition, the freeze-thaw process in the WDFT cycles promoted the softening of the stress-strain relationships and aggravated the failure strength attenuation of expansive mudstones. Through this study, we expect to provide a preliminary basis for the construction and maintenance of expansive mudstone canals in Xinjiang.
5
Jiang, Ping, Xuhui Zhou, Jian Qian, and Na Li. "Experimental Study on the Influence of Dry–Wet Cycles on the Static and Dynamic Characteristics of Fiber-Modified Lime and Fly Ash-Stabilized Iron Tailings at Early Curing Age." Crystals 12, no. 5 (April 19, 2022): 568. http://dx.doi.org/10.3390/cryst12050568.
Full textAbstract:
Using fiber, lime and fly ash to modify iron tailings and apply them to a road base is an effective way to utilize iron tailings as resources. To explore the influence of fiber on lime and fly ash-stabilized iron tailings (EIT) under dry and wet cycles at an early curing age, the static and dynamic characteristics of EIT and fiber-modified lime and fly ash-stabilized iron tailings (FEIT) under dry and wet cycles were studied through an unconfined compressive strength (UCS) test, splitting test and dynamic triaxial test. The results show the following. (1) EIT and FEIT still have high UCS and splitting strength after dry–wet cycles, and the dry–wet cycles can promote the static properties of FEIT. (2) The dry–wet cycle is the main factor affecting the change in the dynamic elastic modulus of EIT and FEIT. The dynamic elastic modulus of EIT first increases and then decreases with the increase in dry–wet cycles, and the dynamic elastic modulus of FEIT first decreases and then increases with the increase in dry–wet cycles. The damping ratio of EIT and FEIT decreases with the increase in dry–wet cycles, and then tends to be stable. (3) After seven dry–wet cycles, the compressive performance, tensile performance, deformation resistance and vibration resistance of FEIT are better than those of EIT. This study can provide a reference for the resource application of iron tailings in road engineering.
6
Xu, Jian, Chang Ren, Songhe Wang, Jingyu Gao, and Xiangang Zhou. "Permeability and Microstructure of a Saline Intact Loess after Dry-Wet Cycles." Advances in Civil Engineering 2021 (March 10, 2021): 1–18. http://dx.doi.org/10.1155/2021/6653697.
Full textAbstract:
Influenced by both dry-wet cycles and salt weathering, the loess will exhibit significant changes in microstructure and permeability, which threatens the stability of loess slopes. Triaxial permeability tests and industrial computed tomography (CT) scans were carried out on saline intact loess with sodium sulfate. The relationship between permeability and pore structure of the loess after dry-wet cycles was discussed. Results show that the permeability coefficient of loess increases after dry-wet cycles, with the increment declining. After specified dry-wet cycles, the permeability coefficient increases approximately linearly with sodium sulfate content. However, the permeability coefficient significantly declines at higher confining pressures, while its attenuation rate decreases. An empirical relationship based on log 10 1 + e − log 10 k was proposed to estimate the permeability coefficient of saline intact loess considering dry-wet cycles and salt content. Comparisons of measured and calculated results proved its rationality. CT scan images imply the damage to soil microstructure induced by dry-wet cycles and salt weathering, corresponding to the decline of the mean CT value (ME) and the increase of both crack ratio and fractal dimension of crack network.
7
Qi, Yanli, MingZhou Bai, Hao Zhou, Hai Shi, Pengxiang Li, and Bohu He. "Study on the Mechanical Properties of Red Clay under Drying-Wetting Cycles." Advances in Materials Science and Engineering 2021 (June 15, 2021): 1–16. http://dx.doi.org/10.1155/2021/8665167.
Full textAbstract:
To study the mechanical properties of red clay under repeated dry and wet cycle test conditions, in this paper, the disturbed red clay in an engineering area in Liuzhou, Guangxi Province, was taken as the research object. By artificially controlling different dry and wet cycles in the laboratory, a direct shear test and triaxial consolidation drainage test were carried out on the red clay samples after different dry and wet cycles. The stress-strain curve and change rule of corresponding c and φ values were obtained. The results showed that, in both the direct shear test and the triaxial test, the shear strength parameters of red clay decreased with an increase in the number of dry and wet cycles and the attenuation was most obvious during the first cycle. With an increase in the number of dry and wet cycles, the attenuation gradually decreased. The constitutive model of the deviatoric stress and strain curve of red clay under dry and wet cycles was a plastic-hardening type. By analyzing the variation in parameters in the P-H model, the relationship between c, φ, and the number of dry and wet cycles n was obtained. The results showed that the parameters had different degrees of attenuation with the action of dry and wet cycles. To explain the above rules, some samples under different drying-wetting cycles were selected for environmental electron microscope scanning, and appropriate assumptions were made based on the microstructure.
8
Song, Zhaoyang, Lihui Sun, Shouye Cheng, Zhiqiang Liu, Jie Tan, and Fangbo Ning. "Experimental Study on the Property Degradation and Failure Mechanism of Weakly Cemented Sandstone under Dry-Wet Cycles." Advances in Materials Science and Engineering 2022 (January 18, 2022): 1–16. http://dx.doi.org/10.1155/2022/9431319.
Full textAbstract:
Taking the weakly cemented sandstone of Ordos, China, as the research object, the evolution law between the relative stress of weakly cemented sandstone and the multiparameters of the acoustic emission under different dry-wet cycles was explored, and the critical failure identification mode of weakly cemented sandstone under dry-wet cycle was established. The results show that as the number of dry-wet cycles increases, the wave velocity loss rate gradually increases. Overall, the longitudinal wave loss rate is larger than the shear wave loss rate, indicating that the longitudinal wave is more sensitive to the degradation of weakly cemented sandstone. With an increase in the number of dry-wet cycles, the crack is mainly caused by the main crack penetration failure, and the secondary crack is significantly reduced. The fractal dimension decreases with an increase in the dry-wet cycles and reaches its maximum at 0 dry-wet cycles, which means that 0 dry-wet cycles witness the most complex morphology of fractures within the weakly cemented sandstone. This finding indicates that the dry-wet cycle inhibits the generation and expansion of fractures. The event rate appears to be close to 0 before the rupture, and then the platform oscillates, followed by a sudden increase. The acoustic emission b value is relatively high during the initial stage and then decreases, which is the initial damage process. The elastoplastic phase rises again, the peak stage decreases rapidly, and the weakly cemented sandstone undergoes unstable damage. The change in the acoustic emission entropy value is exactly the opposite of the b value change law. When the weakly cemented sandstone reaches the critical failure state under different dry-wet cycles, the relative stress value is 95%. The test results provide new methods and a basis for the damage evolution mechanism and fracture prediction of weakly cemented sandstone under dry-wet cycles.
9
Wang, Linzhi, Mingzhong Gao, and Jiqiang Zhang. "Effect of Continuous Loading Coupled with Wet–Dry Cycles on Strength Deterioration of Concrete." Sustainability 14, no. 20 (October 18, 2022): 13407. http://dx.doi.org/10.3390/su142013407.
Full textAbstract:
In practical engineering, concrete is often under continuous stress conditions and there are limitations in considering the effect of wet–dry cycles alone on the strength deterioration of concrete. In order to study the deterioration of concrete strength under the coupling of load and wet-dry cycles, concrete specimens were loaded with 0%, 10%, 20%, and 35% stress levels and coupled to undergo one, three, and seven wet–dry cycles. The strength deterioration of the concrete was obtained by uniaxial compression and the regression equation was established. The strength deterioration mechanism of the concrete under the coupled conditions was analyzed and revealed through an AE acoustic emission technique and nuclear magnetic resonance technique. The results of the study show that, with the same number of wet–dry cycles, there are two thresholds of a and b for the uniaxial compressive strength of concrete with the stress level, and with the progression of wet–dry cycles, the length of the interval from a to b gradually shortens until it reaches 0. The cumulative AE energy of concrete decreases with the progression of wet–dry cycles; using the initiating crack stress as the threshold, the calm phase of concrete acoustic emission, the fluctuating phase, and the NMR T2 spectral peak area show different patterns of variation with the increase in the number of wet–dry cycles.
10
Li, S. N., Z. H. Huang, Q. Liang, J. Liu, S. L. Luo, and W. Q. Zhou. "Evolution Mechanism of Mesocrack and Macrocrack Propagation in Carbonaceous Mudstone under the Action of Dry-Wet Cycles." Geofluids 2022 (July 19, 2022): 1–8. http://dx.doi.org/10.1155/2022/6768370.
Full textAbstract:
The crack propagation evolution of carbonaceous mudstone under the action of dry-wet cycles is an important cause of the unstable failure of this type of slope. This paper attempts to reveal the evolution mechanism of mesocrack and macrocrack propagation in carbonaceous mudstone under the action of dry-wet cycles from chemical, physical, and mechanical perspectives. Firstly, the soaking solution of carbonaceous mudstone during the dry-wet cycles was extracted for an ion concentration test to analyze the chemical reactions of carbonaceous mudstone. Then, CT scans were performed on the carbonaceous mudstone samples to study the changing pattern of mesostructure of carbonaceous mudstone during the dry-wet cycles. In the end, the mechanical properties and failure characteristics of carbonaceous mudstone after dry-wet cycles were studied by triaxial compression tests. The results showed that chemical reactions such as calcite dissolution, potassium feldspar hydrolysis, and sodium feldspar hydrolysis occurred during the dry-wet cycle of carbonaceous mudstone. Affected by the dry-wet cycles, the mesostructure of the carbonaceous mudstone gradually changed from face-face contact and edge-face contact to edge-corner contact and corner-corner contact, and the interlayer flake structure was opened and was locally curled and fractured. With the increase in the number of dry-wet cycles, the failure characteristic of carbonaceous mudstone transformed from tensile failure to shear failure, the failure surface of carbonaceous mudstone was deflected from 90° to 60°, and the crack propagation path of carbonaceous mudstone became more complicated. The chemical reaction of carbonaceous mudstone minerals during the dry-wet cycle is an important reason for the initiation and development of pores. The dry-wet cycle aggregates the propagation of mesocracks and structural disorder, transforming the uniform stress state of the rock mesostructure to the concentrated stress state, which is the important reason for the macrocrack propagation evolution of carbonaceous mudstone.
Dissertations / Theses on the topic "Wet and Dry cycles"
1
Olshansky, Yaniv, Robert A. Root, and Jon Chorover. "Wet–dry cycles impact DOM retention in subsurface soils." COPERNICUS GESELLSCHAFT MBH, 2018. http://hdl.handle.net/10150/627113.
Full textAbstract:
Transport and reactivity of carbon in the critical zone are highly controlled by reactions of dissolved organic matter (DOM) with subsurface soils, including adsorption, transformation and exchange. These reactions are dependent on frequent wet–dry cycles common to the unsaturated zone, particularly in semi-arid regions. To test for an effect of wet–dry cycles on DOM interaction and stabilization in subsoils, samples were collected from subsurface (Bw) horizons of an Entisol and an Alfisol from the Catalina-Jemez Critical Zone Observatory and sequentially reacted (four batch steps) with DOM extracted from the corresponding soil litter layers. Between each reaction step, soils either were allowed to air dry (wet–drytreatment) before introduction of the following DOM solution or were maintained under constant wetness (
continually wettreatment). Microbial degradation was the dominant mechanism of DOM loss from solution for the Entisol subsoil, which had higher initial organic C content, whereas sorptive retention predominated in the lower C Alfisol subsoil. For a given soil, bulk dissolved organic C losses from solution were similar across treatments. However, a combination of Fourier transform infrared (FTIR) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopic analyses revealed that wet–dry treatments enhanced the interactions between carboxyl functional groups and soil particle surfaces. Scanning transmission X-ray microscopy (STXM) data suggested that cation bridging by Ca2+ was the primary mechanism for carboxyl association with soil surfaces. STXM data also showed that spatial fractionation of adsorbed OM on soil organo-mineral surfaces was diminished relative to what might be inferred from previously published observations pertaining to DOM fractionation on reaction with specimen mineral phases. This study provides direct evidence of the role of wet–dry cycles in affecting sorption reactions of DOM to a complex soil matrix. In the soil environment, where wet–dry cycles occur at different frequencies from site to site and along the soil profile, different interactions between DOM and soil surfaces are expected and need to be considered for the overall assessment of carbon dynamics.
2
Al-Hussaini, Osama. "Volume change behaviour of some geomaterials under combined influence of freeze-thaw and wet-dry cycles : an experimental investigation." Thesis, Cardiff University, 2017. http://orca.cf.ac.uk/110778/.
Full textAbstract:
Climate change has led to more extreme weather during the last decades. Seasonally hot weather regions have experienced harsh winters. Similarly, the global warming has contributed to raising the mean summer temperature in the cold regions. Geomaterials in various engineering applications are expected to experience such changes in the weather patterns and may undergo freezing, thawing, wetting and drying processes. This thesis presents an experimental study of the one-dimensional volume change behaviour of some geomaterials under the combined influence of freeze-thaw and wet-dry cycles. Laboratory tests were carried out on three selected materials (Speswhite kaolin, Pegwell Bay soil and cement kiln dust). A custom-made test set up was used to carry out the laboratory tests that enabled performing the required tests involving freezing, thawing, drying and wetting processes. Initially saturated slurried materials and compacted materials were subjected to freezing and thawing processes to study frost heave and thaw settlement. Compacted materials were taken through several wet-dry cycles and then exposed to freezing and thawing processes to study the impact of intermittent freeze-thaw cycles on the volume change behaviour of the materials. Similarly, compacted materials were subjected to an increasing number of freeze-thaw-wet-dry cycles to study the combined influence of various processes on the volume change behaviour of the materials. Compacted materials exhibited higher magnitudes of frost heave than initially saturated slurried materials. The swelling and shrinkage strains of compacted materials decreased with an increasing number of wet-dry cycles and attained an equilibrium at which the strains remained very similar. Intermittent freeze-thaw cycles were found to destabilize the equilibrium strain that was achieved during the previous wet-dry cycles; however, a new equilibrium in terms of the vertical strain was attained by the materials with an increasing number of wet-dry cycles. The materials having a history of being exposed to several wet-dry cycles exhibited a higher frost heave, a higher segregation potential and a greater magnitude of thaw settlement as compared to the same materials but without any cyclic wet-dry history. Upon subjected to an increasing number of wet-freeze-thaw-dry cycles, the materials exhibited uprising movement accompanied by strain accumulation prior to attaining an equilibrium at which the vertical strains associated with wetting, freezing, thawing and drying processes were found to be dissimilar; however, the sum of swelling deformation and frost heave was found to be equal to the sum of thaw settlement and shrinkage deformation.
3
O'Keefe, Sorche. "The recovery of soils after compaction : a laboratory investigation into the effect of wet/dry cycles on bulk density and soil hydraulic functions." Thesis, Cranfield University, 2009. http://dspace.lib.cranfield.ac.uk/handle/1826/4493.
Full textAbstract:
Van den Akker et al. (2003) stated that “European subsoils are more threatened than ever in history” in an editorial referring to the results of the European Union concerted action “Experiences with the impact of subsoil compaction on soil crop growth and environment and ways to prevent subsoil compaction”. Compaction of agricultural soils not only reduces yields but can lead to pollution of surface waters and the release of greenhouse gases. Understanding, therefore, how, and to what extent, subsoil compaction may be reversed seems of vital importance. The literature suggests that soils with a range of textures could recover structural properties such as total and macro-porosity, infiltration rate and stability, although the extent and depth of these changes varies greatly. Factors affecting the extent and depth of changes are the rate of wetting and drying and the matric potentials achieved during drying (influenced by crop cover and irrigation practices as well as climate), organic matter content and tillage history. There is, however, a limited amount of information regarding changes to the pore-size distribution and unsaturated hydraulic conductivity of soils with wet/dry cycles. Although there are models able to predict the compaction that would occur for a given set of conditions, as well as the compactibility of soils and surface crack generation, there are no predictive models that describe structural changes due to wet/dry cycles. The aims of this study were to assess the changes in bulk density and hydrological parameters of a range of soils, of varying texture and other physical and chemical properties, with wet/dry cycles and to explore the relationships between any measured changes and the measured soil properties. A series of laboratory experiments were designed to measure changes to the total porosity and pore size distribution and hydraulic functions of soil samples. Changes to bulk density and moisture content of undisturbed soil cores at field capacity with wet/dry cycles were monitored. Changes to the moisture release curve and hydraulic conductivity curve (as well as bulk density) of remoulded clayey subsoil samples, with wet/dry cycles, were estimated using the multi-step outflow method. The surface cracking of the samples during the wetting and drying process was also explored. Changes to these parameters were statistically compared between soils and between initial bulk densities, and related to soil properties such as texture, organic matter content and Atterberg limits with a general linear model for repeated measures. Changes to the bulk density of the soils after three wet/dry cycles were found to be significantly different (at the 95 % probability level) between soils and between initial bulk densities. It was found that 90 % of the changes in bulk density could be predicted from the initial bulk density and the liquid limit of soils alone. The porosity gained or lost during wet/dry cycles was not confined to the macro-pore region, but included changes to pores that were undrained at pressures up to and including 100 m of water. Changes in the pore size distribution, as described by the parameters of the water release curve, modelled with the van Genuchten-Mualem equation, were found to be statistically related to soil texture and Atterberg limits. Changes to the hydraulic conductivity function of the soils were found to be affected by changes to the connectivity of the pore network, not just to changes in the volume of conducting pores. This was particularly true of the saturated hydraulic conductivity which was found to increase the most in soil samples that experienced a concomitant increase in bulk density and decrease in macro-porosity. Changes to the area of surface cracks were found to be significantly related to changes in the saturated hydraulic conductivity and to changes in the parameters of the van Genuchten-Mualem equation. It was also found that cracks did not close up entirely when the samples were saturated and there were many instances where wetting increased the area of surface cracks, relative to the preceding dry event, implying that the wetting phase was as important in structural formation as the drying phase. There is a strong suggestion that it would be possible to construct a relatively simple model, based on easily measurable parameters, which could be used to predict the changes to soil structure achievable with wet/dry cycles. Further research is needed, therefore, that extends the data set upon which the predictive model designed in this study was constructed. Refinement of the model to include information on the rates of wetting and drying would also contribute greatly to its applicability to the field situation. However, important steps have been made by this study towards a more comprehensive understanding of soil structural dynamics.
4
Marchi, Fabio. "Effect of moisture susceptibility on different bituminous mastics." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/17619/.
Full textAbstract:
Moisture or water damage in asphalt mixtures can be defined as the loss of strength and durability, and an increase in stiffness leading to a more brittle behavior of materials and cause the adhesive failure at the binder-aggregate surface and/or cohesive failure within the binder or mastics. The performance and behaviour of asphalt mixtures are strictly dependent on the response of bituminous binders and mastics. The scope of this research is to acquire information on how moisture may affect rheological and chemical properties of different mastics made by different fillers. A neat bitumen and four mastics were prepared and tested, each of which combined with a specific filler. The conditioning procedure consisted in repeating wetting and drying cycles for three times. After each conditioning phase, couple of samples were tested by means of Dynamic Shear Rheometer (DSR) and Fourier Transfer Infrared spectrometer (FTIR). DSR was employed to determine the rheological properties of materials, such as the complex shear modulus (G*) and the phase angle (δ) at different temperatures and frequencies. FTIR has been used to investigate the chemical composition of bitumen and mastics after its reaction with water, in particular a specific range of wavelength was investigated to determine the absorption of the water and to combine data coming from rheological analysis. At high frequency and/or low temperature all materials behave as a solid; both rheological parameters (complex shear modulus and phase angle) tend to an asymptotic value throughout all the conditioning processes, whereas at low frequency and/or high temperatures is evident an increase of the complex shear modulus, due to water intrusion. Differences between mastics and neat bitumen are present in the intermediate frequency region. FTIR spectra for all mastics confirmed their rheological behavior.
5
Foerster, Verena Elisabeth [Verfasser], Frank [Akademischer Betreuer] Schäbitz, and Olaf [Akademischer Betreuer] Bubenzer. "Late Quaternary climate variability in the source region of Homo sapiens. Dry-wet cycles in Chew Bahir, southern Ethiopia / Verena Elisabeth Foerster. Gutachter: Frank Schäbitz ; Olaf Bubenzer." Köln : Universitäts- und Stadtbibliothek Köln, 2014. http://d-nb.info/1071369873/34.
Full text
6
Ji, Xiaoyan. "Thermodynamic properties of humid air and their application in advanced power generation cycles." Doctoral thesis, Stockholm : Department of Chemical and Engineering and Technology, Royal Institute of Technology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4129.
Full text
7
BAJNI, GRETA. "STATISTICAL METHODS TO ASSESS ROCKFALL SUSCEPTIBILITY IN AN ALPINE ENVIRONMENT: A FOCUS ON CLIMATIC FORCING AND GEOMECHANICAL VARIABLES." Doctoral thesis, Università degli Studi di Milano, 2022. http://hdl.handle.net/2434/913511.
Full textAbstract:
The overarching goal of the doctoral thesis was thus the development of a systematic procedure capable to examine and enhance the role of geomechanical and climatic processes in rockfall susceptibility, performed with statistically based and Machine Learning techniques. To achieve this purpose, two case studies were analysed in the Italian Alps (Valchiavenna, Lombardy Region; Mountain Communities of Mont Cervin and Mont Emilius, Aosta Valley Region).
For both case studies, Generalized Additive Models (GAM) were used for rockfall susceptibility assessment; for the Valchiavenna case study, a Random Forest (RF) model was tested too. All models were validated through k-fold cross validation routines and their performance evaluated in terms of area under the receiver operating characteristic curve (AUROC). Predictors’ behaviour physical plausibility was verified through the analysis of the mathematical functions describing the predictors-susceptibility modelled relationships. Specific objectives of the two case studies differed.
The Valchiavenna case study was dedicated to testing the role of the outcrop-scale geomechanical properties in a rockfall susceptibility model. Specific objectives were: (i) the optimal selection of sampling points for the execution of geomechanical surveys to be integrated within an already available dataset; (ii) the regionalization over the study area of three geomechanical properties, namely Joint Volumetric Count (Jv), rock-mass weathering index (Wi) and rock-mass equivalent permeability (Keq); (iii) the implementation of the regionalized properties as predictors in a rockfall susceptibility model, along with the traditional morphometric variables; (iv) the investigation of prediction limitations related to inventory incompleteness; (v) the implementation of a methodology for the interpretation of predictors’ behaviour in the RF model, usually considered a black box algorithm; (vi) the integration of the RF and GAM outputs to furnish a spatially distributed measure of uncertainty; (vii) the exploitation of satellite-derived ground deformation data to verify susceptibility outputs and interpret them in an environmental management perspective.
The additional geomechanical sampling points were selected by means of the Spatial Simulated Annealing technique. Once collected the necessary geomechanical data, regionalization of the geomechanical target properties was carried out by comparing different deterministic, regressive and geostatistical techniques. The most suitable technique for each property was selected and geomechanical predictors were implemented in the susceptibility models. To verify rockfall inventory completeness related effects, the GAM model was performed both on rockfall data from the official landslide Italian inventory (IFFI) and on its updating with a field-mapped rockfall dataset. Regarding the RF model, the Shapely Additive exPlanations (SHAP) were employed for the interpretation of the predictors’ behaviour. A comparison between GAM and RF related outputs was carried out to verify their coherency, as well as a quantitative integration of the resulting susceptibility maps to reduce uncertainties. Finally, the rockfall susceptibility maps were coupled with Synthetic Aperture Radar (SAR) data from 2014 to 2021: a qualitative geomorphological verification of the outputs was performed, and composite maps were produced.
The key results were: (i) geomechanical predictor maps were obtained applying an ordinary kriging for Jv and Wi (NRMSE equal to 13.7% and 14.5%, respectively) and by means of Thin Plate Splines for Keq (NRMSE= 18.5%). (ii) Jv was the most important geomechanical predictor both in the GAM (witha deviance explained of 7.5%) and in the RF model, with a rockfall susceptibility increase in correspondence of the most fractured rock masses. (iii) Wi and Keq were penalized (i.e., they had low influence on rockfall susceptibility) in the GAM model, whereas Keq showed an importance comparable to Jv in the RF model. (iv) In a complex Machine Learning model (RF), the SHAPs allowed the interpretation of predictors’ behaviour, which demonstrated to be coherent with that shown in the GAM model. (v) The models including the geomechanical predictors resulted in acceptable rockfall discrimination capabilities (AUROC>0.7). (vi) The introduction of the geomechanical predictors led to a redistribution of the high-susceptibility areas in plausible geomorphological contexts, such as in correspondence of active slope deformations and structural lineaments, otherwise not revealed by the topographic predictors alone. (vii) Models built with solely the IFFI inventory, resulted in physically implausible susceptibility maps and predictor behaviour, highlighting a bias in the official inventory. (viii) The discordance in predicting rockfall susceptibility between the GAM and the RF models varied from 13% to 8% of the total study area. (ix) From the integration of InSAR data and susceptibility maps, a “SAR Integrated Susceptibility Map”, and an “Intervention Priority Map” were developed as operational products potentially exploitable in environmental planning activities.
The Aosta Valley case study was dedicated to challenge the concept of “susceptibility stationarity” by including the climate component in the rockfall susceptibility model. The availability of a large historical rockfall inventory and an extensive, multi-variable meteorological dataset for the period 1990-2020 were crucial input for the analysis. Specific objectives were: (i) the identification of climate conditions related to rockfall occurrence (ii) the summary of the identified relationships in variables to be used in a susceptibility model; (iii) the optimization of a rockfall susceptibility model, including both topographic, climatic and additional snow-related predictors (from a SWE weekly gridded dataset).
Starting from an hourly meteorological dataset, climate conditions were summarized in indices related to short-term rainfall (STR), effective water inputs (EWI, including rainfall and snow melting), wet-dry cycles (WD) and freeze-thaw cycles (FT). Climate indices and rockfall occurrence time series were paired. Critical thresholds relating rockfall occurrence to climate indices not-ordinary values (>75th percentile) were derived through a statistical analysis. As summary variables for the susceptibility analysis, the mean annual threshold exceedance frequency for each index was calculated. Model optimization consisted in stepwise modifications of the model settings in order to handle issues related to inventory bias, physical significance of climatic predictors and concurvity (i.e., predictors collinearity in GAMs). The starting point was a “blind model”, i.e., a susceptibility model created without awareness of the rockfall inventory characteristics and of the physical processes potentially influencing susceptibility. To reduce the inventory bias, “visibility” masks were produced so to limit the modelling domain according to the rockfall collection procedures adopted by administrations. Thirdly, models were optimized according to the physical plausibility of climatic predictors, analysed through the smooth functions relating them to susceptibility. Finally, to reduce concurvity, a Principal Component Analysis (PCA) including climatic and snow-related predictors was carried out. Subsequently, the obtained principal components were used to replace the climatic predictors in the susceptibility model.
The key results were: (i) the 95% of the rockfalls occurred in severe (or not ordinary) conditions for at least one among the EWI, WD and FT indices; (ii) ignoring inventory bias led to excellent model performance (0.80≤AUROC ≤0.90) but physically implausible outputs; (iii) the selection of non-rockfall points inside the “visibility mask” was a valuable approach to manage the inventory bias influence on outputs; (iv) the inclusion of climate predictors resulted in an improvement of the susceptibility model performance (AUROC up to 3%) in comparison to a topographic-based model; (v) the most important physically plausible climate predictors were EWI, WD, with a deviance explained varying from 5% to 10% each, followed by the maximum cumulated snow melting with a deviance explained varying from 3% to 5%. The effect of FT was masked by elevation. (vi) When the climate and snow related predictors were inserted in the susceptibility model as principal components, concurvity was efficiently reduced.
The inclusion of climate processes as non-stationary predictors (i.e., considering climate change) could be a valuable approach both to derive long-term rockfall susceptibility future scenarios and in combination with short-term weather forecasts to adapt susceptibility models to an early warning system for Civil Protection purpose.
8
Thouin, Hugues. "Transfert de polluants inorganiques dans un technosol de brûlage d’armes organo-arséniées soumis à un apport de matière organique et à des cycles de saturation/désaturation : expérimentation en mésocosme." Thesis, Orléans, 2016. http://www.theses.fr/2016ORLE2069/document.
Full textAbstract:
La destruction par brûlage de munitions chimiques de la Première Guerre Mondiale a provoqué une contamination importante de la partie supérieure du sol du site de la Place-à-Gaz par l’arsenic, le zinc, le cuivre et le plomb. Le traitement thermique a eu pour effet de minéraliser l’As des agents de guerre organoarséniés, et de former un assemblage minéral inattendu composé d’arséniates de Zn, Cu et Fe, et d’une phase amorphe riche en Fe, As, Zn, Cu et Pb. Ce matériel amorphe est la principale phase porteuse de l’As et des métaux dans la zone la plus polluée. Le site est sujet à des changements environnementaux pouvant affecter la stabilité des contaminants inorganiques. Afin d’évaluer l’impact d’épisodes de saturation en eau et de l’apport de matière organique sur les cycles biogéochimiques des métaux et de l’As, une étude en mésocosme a été menée. Les résultats montrent que la phase amorphe est instable en conditions saturées, et libère des contaminants dans l’eau interstitielle du sol. Comme sur le site, les contaminants les plus mobiles sont le Zn et l’As. L’addition de matière organique a induit une immobilisation de l’As, par piégeage de l’As V sur les oxyhydroxydes de fer, dans la partie saturée du sol. La caractérisation du compartiment microbien a été effectuée via des dénombrements, une analyse de la diversité bactérienne et des tests d’activités d’oxydation de l’As III et de respiration et. Les résultats montrent que les microorganismes ont contribué activement au métabolisme du C et de l’As. L’apport de matière organique a promu la croissance des microorganismes As III-oxydants et As Vréducteurs et modifié la structure des communautés bactériennes. Cependant, un effet négatif de la matière organique sur la vitesse d’oxydation de l’As III a été observé, entrainant une augmentation des concentrations d’As III en solution. Cette étude en mésocosme a montré que le dépôt naturel de litière organique a des conséquences antagonistes sur le transfert des contaminants inorganiques. Ces résultats fournissent de plus amples informations sur l’impact environnemental de la Grande Guerre et, de façon plus générale, sur les processus biogéochimiques contrôlant le comportement des métaux/métalloïdes sur les sites polluésThe thermal destruction of chemical munitions from World War I, on the site of “Place-à-Gaz”, induced intense local top soil contamination by arsenic and heavy metals. The heat treatment mineralized As from organoarsenic warfare agents, resulting in a singular mineral assemblage, composed of Zn, Cu and Fe arsenates and of an amorphous phase rich in Fe, As, Zn, Cu and Pb. The amorphous material was the principal carrier of As and metals in the central part of the site. The site undergoes environmental changes which may alter the stability of inorganic contaminants. To assess the impact of water saturation episodes and input of bioavailable organic matter on the biogeochemical cycles of metal(loid)s, a mesocosm study was conducted. Results showed that amorphous phase was instable in saturated conditions, and released contaminants in soil water. As previously observed on site, the most mobile contaminants were Zn and As. The addition of organic matter induced the immobilization of As by trapping of As V onto hydrous ferric oxides in the saturated soil. Microbial characterizations including counting, bacterial community structure, respiration, and determination of As IIIoxidizing activities were performed. Results showed that microorganisms actively contribute to the metabolisms of C and As.The addition of organic matter induced the increase of As III-oxidizing and As V-reducing microorganisms concentrations and modified the bacterial diversity. However, a negative effect of organic matter on the activity of As III oxidation was observed resulting in higher As III concentration in soil water. This study showed that the natural deposition of forest organic litter on the site, induced antagonist effects on the transfer of inorganic pollutants did not immobilize all the Zn and As and even contributed to As III transport to the surrounding environment. These results provide more information about the environmental impact of the Great War and more generally about the processes driving the behavior of metals/metalloids on polluted sites
9
Cowan, Linda J. "The use of wet-to-dry dressings." [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0008780.
Full textAbstract:
Thesis (M.S.N.)--University of Florida, 2004.Typescript. Title from title page of source document. Document formatted into pages; contains 73 pages. Includes Vita. Includes bibliographical references.
10
Susna, David. "Návrh chladícího okruhu pro odvod tepla z kondenzátoru parní turbíny." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2018. http://www.nusl.cz/ntk/nusl-378737.
Full textAbstract:
This thesis deals with the problems of wounding of low potential transferred from steam turbine condenser. First, in the theoretical part variations of steam condenser design are described. Then there is a description of variations of cooling cycles and possibilities of their operation range. In second part of the thesis there are two common cooler options chosen. Those are wet cooling tower with natural draft and dry chiller with forced draft. Two types of cooling liquid are chosen to be used for dry cooling. These are water and the other one is 50 % mixture of water and propylene glycol. Based on the calculation results of both cooling cycle variations appropriate pumps are chosen, fan for forced convection respectively. Parts of the thesis are also projection drawings for both calculated variations.
Books on the topic "Wet and Dry cycles"
1
Challoner, Jack. Wet and dry. Austin, Tex: Raintree Steck-Vaughn, 1997.
Find full text
2
Wet and dry. Mankato, Minn: Riverstream Publishing, 2013.
Find full text
3
Doudna, Kelly. Wet and dry. Edina, Minn: Abdo Pub., 2000.
Find full text
4
Leacock, Stephen. Wet or dry? [Canada?: s.n.], 1997.
Find full text
5
McMillan, Bruce. Dry or wet? New York: Lothrop, Lee & Shepard, 1988.
Find full text
6
Kincaid, Doug. Wet and dry. 2nd ed. Walton-on-Thames: Nelson, 1989.
Find full text
7
Wet and dry. Mankato, Minn: Capstone Press, 2006.
Find full text
8
The wet dry book. New York: Random House, 2002.
Find full text
9
Boelts, Maribeth. Dry days, wet nights. Morton Grove, Ill: Whitman, 1994.
Find full text
10
Gordon, Sharon. Wet dry =: Mojado seco. New York: Marshall Cavendish Benchmark, 2007.
Find full textBook chapters on the topic "Wet and Dry cycles"
1
De Camillis, M., G. Di Emidio, A. Bezuijen, and R. D. Verastegui-Flores. "Hydraulic Conductivity of Modified Bentonites After Wet and Dry Cycles." In Proceedings of the 8th International Congress on Environmental Geotechnics Volume 2, 470–80. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-13-2224-2_58.
Full text
2
Fang, Renyi, Bo Fan, and Lei Yu. "Compression damage in high-toughness cementitious composites after dry-wet cycles." In Advances in Civil Engineering and Environmental Engineering, Volume 1, 345–50. London: CRC Press, 2023. http://dx.doi.org/10.1201/9781003349563-49.
Full text
3
Bergin, M. H., C. I. Davidson, H. D. Kuhns, J. L. Jaffrezo, J. E. Dibb, R. Hillamo, and T. Makela. "The Contributions of Wet, Fog, and Dry Deposition to the Summer SO4 2− Flux at Summit, Greenland." In Ice Core Studies of Global Biogeochemical Cycles, 121–38. Berlin, Heidelberg: Springer Berlin Heidelberg, 1995. http://dx.doi.org/10.1007/978-3-642-51172-1_6.
Full text
4
Yin, Shi-Ping, Xiang-Qian Hu, and Chi Peng. "Compressive Performance of TRC-Strengthened Column with Small Eccentricity Under Chloride-Wet-Dry Cycles." In Strain-Hardening Cement-Based Composites, 651–58. Dordrecht: Springer Netherlands, 2017. http://dx.doi.org/10.1007/978-94-024-1194-2_75.
Full text
5
Cheng, Peng, Xie Yangfa, and Li Anran. "Study on strength of red clay under dry-wet cycle." In Advances in Civil Function Structure and Industrial Architecture, 333–37. London: CRC Press, 2022. http://dx.doi.org/10.1201/9781003305019-48.
Full text
6
Beriha, Brundaban, Dipti Ranjan Biswal, and Umesh Chandra Sahoo. "Effect of Wet-Dry Cycles on Mechanical Strength Properties of Cement Stabilized Granular Lateritic Soil." In Sustainable Civil Infrastructures, 112–21. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-030-01917-4_9.
Full text
7
Ahmed, Ameer Hamza, Marco Liebscher, and Viktor Mechtcherine. "Mechanical Performance of Strain Hardening Limestone Calcined Clay Cementitious Composites (SHLC4) Subject to Wet-Dry Cycles." In RILEM Bookseries, 3–12. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-15805-6_1.
Full text
8
Graus, Sandra, Graça Vasconcelos, and Carlos Palha. "Experimental Characterization of the Deterioration of Masonry Materials Due to Wet and Dry and Salt Crystallization Cycles." In RILEM Bookseries, 687–95. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-319-99441-3_74.
Full text
9
Zou, Weilie. "Evolution of soil-water characteristics of expansive soils under dry-wet and freeze-thaw cycles and slope stabilization practice." In Advances in Frontier Research on Engineering Structures Volume 1, 9. London: CRC Press, 2023. http://dx.doi.org/10.1201/9781003336631-7.
Full text
10
Kobayashi, K., Shinichi Komazaki, Toshihei Misawa, and T. Fukuzumi. "Susceptibility of Automobile Spring Steels to Wet-Dry Cyclic Corrosion Induced Environmental Embrittlement." In Key Engineering Materials, 933–38. Stafa: Trans Tech Publications Ltd., 2005. http://dx.doi.org/10.4028/0-87849-978-4.933.
Full textConference papers on the topic "Wet and Dry cycles"
1
Khalil, Ibrahim, Aaron Sahm, and Robert Boehm. "Wet or Dry Cooling?" In ASME 2006 International Solar Energy Conference. ASMEDC, 2006. http://dx.doi.org/10.1115/isec2006-99082.
Full textAbstract:
Two major aspects related to water use in solar power plants are examined. First we compare the water used in various approaches to power generation. These include water requirements for cooling (where applicable) and other needs within the plant. Included is attention to water requirements for makeup in Rankine cycles, as well as for cleaning of concentrating solar systems. In the second thrust, we examine the impacts of using dry cooling for Rankine cycles. It is generally established that this approach requires premiums in both capital and operating costs (the latter is dependent upon the cost of water), as well as a penalty in performance when compared to wet systems. We examine the trends associated with this technology and outline some for the current performance issues with various cooling approaches.
2
Khoury, Naji, Musharraf Zaman, and Joakim Laguros. "Behavior of Stabilized Aggregate Bases Subjected to Cyclic Loading and Wet-Dry Cycles." In Geo-Frontiers Congress 2005. Reston, VA: American Society of Civil Engineers, 2005. http://dx.doi.org/10.1061/40776(155)5.
Full text
3
Chen, Kaisheng, and Zhen Lu. "The Crack Evolution of Red Clay under Wet and Dry Cycles." In 2015 International Forum on Energy, Environment Science and Materials. Paris, France: Atlantis Press, 2015. http://dx.doi.org/10.2991/ifeesm-15.2015.33.
Full text
4
Shi, Beixiao, Shengshui Chen, and Guoli Wang. "Computation Module of Expansive Soil Crack Depth Considering Dry-Wet Cycles." In Geo-Hubei 2014 International Conference on Sustainable Civil Infrastructure. Reston, VA: American Society of Civil Engineers, 2014. http://dx.doi.org/10.1061/9780784478509.005.
Full text
5
Matsui, Y., T. Suzuki, P. Deevanhxay, S. Tsushima, and S. Hirai. "Crack Generation in Catalyst Layer and Micro Porous Layer by Wet-Dry Cycles and its Impact on PEMFC Performance." In ASME 2013 11th International Conference on Fuel Cell Science, Engineering and Technology collocated with the ASME 2013 Heat Transfer Summer Conference and the ASME 2013 7th International Conference on Energy Sustainability. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/fuelcell2013-18099.
Full textAbstract:
In this study, we focused on nano- and micro-scale cracks in the catalyst layer and the micro porous layer of polymer electrolyte membrane fuel cells (PEMFCs) and its impact on cell performance. We applied wet-dry cycles to a conventional test cell to investigate crack generation in the catalyst layer and the micro porous layer. Wet-dry cycles, in which cell temperature was kept at 353K with high- and low-humidified gas alternately applied to the cell, potentially induced mechanical stress to a membrane electrode assembly (MEA) due to membrane hydration and dehydration. As a result, significant degradation of performance was found after the wet-dry cycles. We performed cross-sectional analysis of MEA by using a cross-sectional polisher (CP) and scanning electron microscopy (SEM) to investigate nano- and micro-scale crack generated by the wet-dry cycles in the MEA. The SEM images showed that nano- and micro-scale cracks were significantly generated in the catalyst layer as well as in the micro porous layer after the cycles. We identified cracks in the MEA with different morphologies according to the SEM images, hence, through-plane cracks and in-plane cracks. Through-plane cracks have a deep-valley structure in the MEA while in-plane cracks are formed in an interfacial region between the catalyst layer and the micro porous layer. In-plane cracks could be generated by detachment of the catalyst layer from the micro porous layer due to the wet-dry cycles and potentially decrease in cell performance due to deterioration of electron transport in the MEA. In addition, in case liquid water is accumulated in in-plane cracks, these cracks potentially disturb gas diffusion from the micro porous layer to the catalyst layer. These results clearly showed that mechanical stress induced crack generation in the MEA, resulting in intensive effects on cell performance in PEMFC.
6
Cheng, Xiaokang, Jianxin Peng, and Jianren Zhang. "Influence of Environmental Variables on Chloride Ion Distribution on Concrete Surface under Dry-Wet Cycle." In IABSE Congress, Nanjing 2022: Bridges and Structures: Connection, Integration and Harmonisation. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2022. http://dx.doi.org/10.2749/nanjing.2022.2008.
Full textAbstract:
<p>In order to study the effect of environmental variables on the chloride concentration on the concrete surface under the action of drying and wetting cycles. Firstly, the influence of environmental variables such as monthly average temperature, monthly sunshine duration, and monthly rainfall on the dry-wet time ratio in Haikou and Wenchang was analyzed, and the dry-wet cycle mechanism of the Puqian Bridge was established. Then, according to the dry-wetting cycle mechanism, the influence of multiple factors on the distribution of chloride concentration on the surface was discussed, and a model of the chloride concentration distribution on the surface of unsaturated concrete under the action of multiple factors was established. Finally, the distribution model is compared with the experimental data in the literature to verify the rationality of the distribution model.</p>
7
Li, Han, Yunhui Zhu, Fuxue Sun, and Yi Xiao. "Research on Chloride Ion Diffusion Performance in Early Age Concrete under Dry-Wet Cycles." In The Joint Conferences of 2015 International Conference on Computer Science and Engineering Technology (CSET2015) and 2015 International Conference on Medical Science and Biological Engineering (MSBE2015). WORLD SCIENTIFIC, 2015. http://dx.doi.org/10.1142/9789814651011_0086.
Full text
8
Theivakularatnam, Mathanraj, and Carthigesu T. Gnanendran. "Durability of Lightly Stabilised Granular Material Subjected to Freeze-Thaw and Wet-Dry Cycles." In IFCEE 2015. Reston, VA: American Society of Civil Engineers, 2015. http://dx.doi.org/10.1061/9780784479087.127.
Full text
9
Guang, Jianji, Jun Deng, Tonghua Liu, and Yan Xie. "Flexural capacity of overloading damaged RC T-beams strengthened with CFRP subjected to wet-dry cycles." In International Conference on Performance-based and Life-cycle Structural Engineering. School of Civil Engineering, The University of Queensland, 2015. http://dx.doi.org/10.14264/uql.2016.1146.
Full text
10
Shekhawat, P., N. Shrivastava, and S. Shrivastava. "Experimental Investigation on Durability of Soil Reinforced with Sustainable Fibers Subjected to Wet-Dry Cycles." In ASCE India Conference 2017. Reston, VA: American Society of Civil Engineers, 2018. http://dx.doi.org/10.1061/9780784482032.025.
Full textReports on the topic "Wet and Dry cycles"
1
Kelly, B. Nexant Parabolic Trough Solar Power Plant Systems Analysis; Task 2: Comparison of Wet and Dry Rankine Cycle Heat Rejection, 20 January 2005 - 31 December 2005. Office of Scientific and Technical Information (OSTI), July 2006. http://dx.doi.org/10.2172/887344.
Full text
2
Schiller, Brandon, Tara Hutchinson, and Kelly Cobeen. Cripple Wall Small-Component Test Program: Wet Specimens I (PEER-CEA Project). Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, November 2020. http://dx.doi.org/10.55461/dqhf2112.
Full textAbstract:
This report is one of a series of reports documenting the methods and findings of a multi-year, multi-disciplinary project coordinated by the Pacific Earthquake Engineering Research Center (PEER and funded by the California Earthquake Authority (CEA). The overall project is titled “Quantifying the Performance of Retrofit of Cripple Walls and Sill Anchorage in Single-Family Wood-Frame Buildings,” henceforth referred to as the “PEER–CEA Project.” The overall objective of the PEER–CEA Project is to provide scientifically based information (e.g., testing, analysis, and resulting loss models) that measure and assess the effectiveness of seismic retrofit to reduce the risk of damage and associated losses (repair costs) of wood-frame houses with cripple wall and sill anchorage deficiencies as well as retrofitted conditions that address those deficiencies. Tasks that support and inform the loss-modeling effort are: (1) collecting and summarizing existing information and results of previous research on the performance of wood-frame houses; (2) identifying construction features to characterize alternative variants of wood-frame houses; (3) characterizing earthquake hazard and ground motions at representative sites in California; (4) developing cyclic loading protocols and conducting laboratory tests of cripple wall panels, wood-frame wall subassemblies, and sill anchorages to measure and document their response (strength and stiffness) under cyclic loading; and (5) the computer modeling, simulations, and the development of loss models as informed by a workshop with claims adjustors. This report is a product of Working Group 4: Testing and focuses on the first phase of an experimental investigation to study the seismic performance of retrofitted and existing cripple walls with sill anchorage. Paralleled by a large-component test program conducted at the University of California [Cobeen et al. 2020], the present study involves the first of multiple phases of small-component tests conducted at the UC San Diego. Details representative of era-specific construction, specifically the most vulnerable pre-1960s construction, are of predominant focus in the present effort. Parameters examined are cripple wall height, finish materials, gravity load, boundary conditions, anchorage, and deterioration. This report addresses the first phase of testing, which consisted of six specimens. Phase 1 including quasi-static reversed cyclic lateral load testing of six 12-ft-long, 2-ft high cripple walls. All specimens in this phase were finished on their exterior with stucco over horizontal sheathing (referred to as a “wet” finish), a finish noted to be common of dwellings built in California before 1945. Parameters addressed in this first phase include: boundary conditions on the top, bottom, and corners of the walls, attachment of the sill to the foundation, and the retrofitted condition. Details of the test specimens, testing protocol, instrumentation; and measured as well as physical observations are summarized in this report. In addition, this report discusses the rationale and scope of subsequent small-component test phases. Companion reports present these test phases considering, amongst other variables, the impacts of dry finishes and cripple wall height (Phases 2–4). Results from these experiments are intended to provide an experimental basis to support numerical modeling used to develop loss models, which are intended to quantify the reduction of loss achieved by applying state-of-practice retrofit methods as identified in FEMA P-1100, Vulnerability-Base Seismic Assessment and Retrofit of One- and Two-Family Dwellings.
3
Schiller, Brandon, Tara Hutchinson, and Kelly Cobeen. Cripple Wall Small-Component Test Program: Wet Specimens II (PEER-CEA Project). Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, November 2020. http://dx.doi.org/10.55461/ldbn4070.
Full textAbstract:
This report is one of a series of reports documenting the methods and findings of a multi-year, multi-disciplinary project coordinated by the Pacific Earthquake Engineering Research Center (PEER and funded by the California Earthquake Authority (CEA). The overall project is titled “Quantifying the Performance of Retrofit of Cripple Walls and Sill Anchorage in Single-Family Wood-Frame Buildings,” henceforth referred to as the “PEER–CEA Project.” The overall objective of the PEER–CEA Project is to provide scientifically based information (e.g., testing, analysis, and resulting loss models) that measure and assess the effectiveness of seismic retrofit to reduce the risk of damage and associated losses (repair costs) of wood-frame houses with cripple wall and sill anchorage deficiencies as well as retrofitted conditions that address those deficiencies. Tasks that support and inform the loss-modeling effort are: (1) collecting and summarizing existing information and results of previous research on the performance of wood-frame houses; (2) identifying construction features to characterize alternative variants of wood-frame houses; (3) characterizing earthquake hazard and ground motions at representative sites in California; (4) developing cyclic loading protocols and conducting laboratory tests of cripple wall panels, wood-frame wall subassemblies, and sill anchorages to measure and document their response (strength and stiffness) under cyclic loading; and (5) the computer modeling, simulations, and the development of loss models as informed by a workshop with claims adjustors. This report is a product of Working Group 4 (WG4): Testing, whose central focus was to experimentally investigate the seismic performance of retrofitted and existing cripple walls. This report focuses stucco or “wet” exterior finishes. Paralleled by a large-component test program conducted at the University of California, Berkeley (UC Berkeley) [Cobeen et al. 2020], the present study involves two of multiple phases of small-component tests conducted at the University of California San Diego (UC San Diego). Details representative of era-specific construction, specifically the most vulnerable pre-1960s construction, are of predominant focus in the present effort. Parameters examined are cripple wall height, finish style, gravity load, boundary conditions, anchorage, and deterioration. This report addresses the third phase of testing, which consisted of eight specimens, as well as half of the fourth phase of testing, which consisted of six specimens where three will be discussed. Although conducted in different phases, their results are combined here to co-locate observations regarding the behavior of the second phase the wet (stucco) finished specimens. The results of first phase of wet specimen tests were presented in Schiller et al. [2020(a)]. Experiments involved imposition of combined vertical loading and quasi-static reversed cyclic lateral load onto ten cripple walls of 12 ft long and 2 or 6 ft high. One cripple wall was tested with a monotonic loading protocol. All specimens in this report were constructed with the same boundary conditions on the top and corners of the walls as well as being tested with the same vertical load. Parameters addressed in this report include: wet exterior finishes (stucco over framing, stucco over horizontal lumber sheathing, and stucco over diagonal lumber sheathing), cripple wall height, loading protocol, anchorage condition, boundary condition at the bottom of the walls, and the retrofitted condition. Details of the test specimens, testing protocol, including instrumentation; and measured as well as physical observations are summarized in this report. Companion reports present phases of the tests considering, amongst other variables, impacts of various boundary conditions, stucco (wet) and non-stucco (dry) finishes, vertical load, cripple wall height, and anchorage condition. Results from these experiments are intended to support advancement of numerical modeling tools, which ultimately will inform seismic loss models capable of quantifying the reduction of loss achieved by applying state-of-practice retrofit methods as identified in FEMA P-1100,Vulnerability-Base Seismic Assessment and Retrofit of One- and Two-Family Dwellings.
4
Ohta, Taisuke. LaB6 nanostructures - wet vs dry etch. Office of Scientific and Technical Information (OSTI), January 2019. http://dx.doi.org/10.2172/1491599.
Full text
5
Speed, D. L. Wet/dry sounding reel tape. Final report. Office of Scientific and Technical Information (OSTI), November 1994. http://dx.doi.org/10.2172/57948.
Full text
6
Allemann, R., B. Johnson, and E. Werry. Wet-dry cooling demonstration: A transfer of technology: Final report. Office of Scientific and Technical Information (OSTI), January 1987. http://dx.doi.org/10.2172/7173655.
Full text
7
Schiller, Brandon, Tara Hutchinson, and Kelly Cobeen. Cripple Wall Small-Component - Test Program: Comparisons (PEER-CEA Project). Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, November 2020. http://dx.doi.org/10.55461/lohh5109.
Full textAbstract:
This report is one of a series of reports documenting the methods and findings of a multi-year, multi-disciplinary project coordinated by the Pacific Earthquake Engineering Research Center (PEER) and funded by the California Earthquake Authority (CEA). The overall project is titled “Quantifying the Performance of Retrofit of Cripple Walls and Sill Anchorage in Single-Family Wood-Frame Buildings,” henceforth referred to as the “PEER–CEA Project.” The overall objective of the PEER–CEA Project is to provide scientifically based information (e.g., testing, analysis, and resulting loss models) that measure and assess the effectiveness of seismic retrofit to reduce the risk of damage and associated losses (repair costs) of wood-frame houses with cripple wall and sill anchorage deficiencies as well as retrofitted conditions that address those deficiencies. Tasks that support and inform the loss-modeling effort are: (1) collecting and summarizing existing information and results of previous research on the performance of wood-frame houses; (2) identifying construction features to characterize alternative variants of wood-frame houses; (3) characterizing earthquake hazard and ground motions at representative sites in California; (4) developing cyclic loading protocols and conducting laboratory tests of cripple wall panels, wood-frame wall subassemblies, and sill anchorages to measure and document their response (strength and stiffness) under cyclic loading; and (5) the computer modeling, simulations, and the development of loss models as informed by a workshop with claims adjustors. This report is a product of Working Group 4 (WG4): Testing, whose central focus was to experimentally investigate the seismic performance of retrofit and existing cripple walls. Amongst the body of reports from WG4, in the present report, a suite of four small cripple wall test phases, in total 28 specimens, are cross compared with varied exterior finishes, namely stucco (wet) and non-stucco (dry) exterior finishes. Details representative of era specific construction, specifically the most vulnerable pre-1960s construction are of predominant focus in the present effort. Experiments involved imposition of combined vertical loading and quasi-static reversed cyclic lateral load onto cripple walls of 12 ft in length and 2 ft or 6 ft in height. All specimens in this report were constructed with the same boundary conditions and tested with the same vertical load. Parameters addressed in this report include: wet exterior finishes (stucco over framing, stucco over horizontal lumber sheathing, and stucco over diagonal lumber sheathing); and dry exterior finishes (horizontal siding, horizontal siding over diagonal sheathing, and T1-11 wood structural panels) with attention towards cripple wall height and the retrofit condition. The present report provides only a brief overview of the test program and setup; whereas a series of three prior reports present results of test groupings nominally by exterior finish type (wet versus dry). As such, herein the focus is to cross compare key measurements and observations of the in-plane seismic behavior of all 28 specimens.
8
Hartle, Jennifer C., Ossama (Sam) A. Elrahman, Cara Wang, Daniel A. Rodriguez, Yue Ding, and Matt McGahan. Assessing Public Health Benefits of Replacing Freight Trucks with Cargo Cycles in Last Leg Delivery Trips in Urban Centers. Mineta Transportation Institute, June 2022. http://dx.doi.org/10.31979/mti.2022.1952.
Full textAbstract:
Increased urbanization, population growth, and demand for time-sensitive deliveries means increased freight movement in cities, which contributes to emissions, noise, and safety concerns. One innovative mode gaining widespread attention for urban deliveries is cargo cycles—bicycles adapted for freight delivery. Despite the recognized potential and possible success of transporting at least 25% of freight via cycle, research remains limited. This research investigates the potential of cargo cycle delivery for last mile freight in Oakland, California, with a focus on the West Oakland neighborhood. The data collection included interviews, focus groups, vehicle field observation and counts, and traffic simulation modeling. The traffic simulation examined scenarios where businesses converted different percentages of current deliveries to cargo cycles using a transfer hub as the starting point for their cargo cycle delivery. The best-case scenario—where the maximum percentage of deliveries were made with cargo cycle instead of motorized vehicles—resulted in reductions of 2600 vehicle miles traveled (VMT) per day. In that case scenario, the vehicle miles traveled (VMT) reduction is equivalent to a reduction in emissions of PM2.5, PM10, NOx, and reactive organic gas (ROG) of taking about 1000 Class 4 box trucks off the roads of West Oakland per day. In the worst-case scenario, with a significantly smaller percentage of motorized package deliveries converted to cargo cycles, there is a reduction of 160 VMT, equivalent to the removal of approximately 80 Class 4 box trucks off the roads of West Oakland per day. This potential reduction in air pollution and traffic congestion, as well as job creation, would benefit West Oakland residents.
9
Blau, P. J., R. L. Martin, M. H. Weintraub, Ho Jang, and W. Donlon. Frictional behavior of automotive brake materials under wet and dry conditions. Office of Scientific and Technical Information (OSTI), December 1996. http://dx.doi.org/10.2172/442128.
Full text
10
Dexter, W. 2010 Dry and 2009 - 2010 Wet Season Branchiopod Survey Report, Site 300. Office of Scientific and Technical Information (OSTI), March 2011. http://dx.doi.org/10.2172/1021550.
Full text