scholarly journals IMPACT OF FIBER DIAMETER ON-ROAD PERFORMANCE OF CEMENT-STABILIZED MACADAM

2017 ◽  
Vol 12 (1) ◽  
pp. 12-20 ◽  
Author(s):  
Zhijun Liu ◽  
Dongquan Wang ◽  
Xiaobi Wei ◽  
Liangliang Wang
Keyword(s):  
Water Loss ◽  
Loss Rate ◽  
Surface Effect ◽  
Fiber Diameter ◽  
Base Material ◽  
The Road ◽  
Water Loss Rate ◽  
Reinforced Cement ◽  
Road Performance ◽  
The Impact

Cement-stabilized macadam is the most widely used road base material in road engineering. The current study investigated the impact of fiber diameter on its performance. The authors prepared polyester fibers with diameters of 20, 35, 70, and 105 μm and added them to cement-stabilized macadam. Then, the indoor shrinkage tests and mechanical property tests at different ages were conducted. Then, the property changes of the polyester-reinforced cement-stabilized macadam were analysed. The water loss rate of the polyester-reinforced cement-stabilized macadam is subject to the combined influence of the “water loss surface effect” and “water loss porthole effect.” With increasing fiber diameter, the water loss surface effect becomes stronger, and the water loss porthole effect gradually decreases; thus, the overall effect transitions from the latter to the former. Moreover, the water loss rate shows an increasing trend of decreasing to its minimum. Therefore, with increasing fiber diameter, the average dry shrinkage coefficient of the polyester-reinforced cement-stabilized macadam first increases and then decreases, while the temperature shrinkage coefficients increase. The change in the fiber diameter does not significantly affect the compressive resilient modulus of the polyester-reinforced cement-stabilized macadam if the fiber content remains constant. These findings demonstrate the functional mechanism of the fiber diameter on the road performance of cement-stabilized macadam, thus improving our understanding of the road performance of the polyester-reinforced cement-stabilized macadam and laying a solid theoretical foundation for its many applications.

Using laboratory selection for desiccation resistance to examine the relationship between respiratory pattern and water loss in insects.

1998 ◽  
Vol 201 (21) ◽  
pp. 2945-2952 ◽  
Author(s):  
A E Williams ◽  
M R Rose ◽  
T J Bradley
Keyword(s):  
Drosophila Melanogaster ◽  
Water Loss ◽  
Loss Rate ◽  
Respiratory Pattern ◽  
Desiccation Resistance ◽  
Water Loss Rate ◽  
Laboratory Selection ◽  
Selection For ◽  
The Relationship ◽  
Co2 Release

We conducted concurrent measurements of rates of CO2 and H2O release from individual fruit flies Drosophila melanogaster taken from populations subjected to three different selective regimes: (1) populations selected for resistance to desiccation (D flies); (2) populations maintained as their controls (C flies); and (3) the ancestral populations of the D and C populations (O flies). In the D flies, water loss rates were significantly reduced, the standard error of the regression (SER) of the CO2 release pattern measured over the survival period of the flies was increased, and the ratio of CO2 loss to H2O loss (VCO2/VH2O) was increased. Correlations across all 15 populations from the three selection treatments indicate that survival time was negatively correlated with water loss rate, positively correlated with the SER of CO2 release and positively correlated with the VCO2/VH2O ratio. We did not, however, find a significant correlation between the SER of CO2 release and rates of water loss or the VCO2/VH2O ratio.

The effect of respiratory pattern on water loss in desiccation-resistant Drosophila melanogaster.

1998 ◽  
Vol 201 (21) ◽  
pp. 2953-2959 ◽  
Author(s):  
A E Williams ◽  
T J Bradley
Keyword(s):  
Drosophila Melanogaster ◽  
Water Loss ◽  
Loss Rate ◽  
Extended Period ◽  
Peak Height ◽  
Respiratory Pattern ◽  
Water Loss Rate ◽  
Selection For ◽  
Reduced Water ◽  
Co2 Release

We measured CO2 and H2O release from individual fruit flies from five populations of Drosophila melanogaster selected for resistance to desiccation (D flies). Our previous work found that these flies survive for an extended period in dry air, have an increase in the peak height and frequency of CO2 release, as measured by the standard error of a linear regression (SER) of CO2 release for the entire survival period, and have reduced water loss rates (VH2O) compared with their control or ancestor populations. In the present study, we examined the following respiratory characteristics: VCO2, VH2O, the SER of CO2 release and the ratio of VCO2 to VH2O in the D flies. Correlations between these characters were calculated in order to determine the effect of respiratory pattern on water loss. We found that, within the D flies, neither periodic release of CO2 nor an increased SER for CO2 release was associated with reduced water loss. In addition, an increased SER was positively correlated with both an increased water loss rate and a decreased survival time. Therefore, although selection for desiccation resistance leads to both an increased SER and a decreased rate of water loss in the D flies, the increased SER does not significantly reduce respiratory water loss.

scholarly journals Study of the Physiological, Molecular and Genetic Factors Associated with Postharvest Water Loss in Pepper Fruit

2012 ◽  
Author(s):  
Elazar Fallik ◽  
Robert Joly ◽  
Ilan Paran ◽  
Matthew A. Jenks
Keyword(s):  
Shelf Life ◽  
Capsicum Annuum ◽  
Water Loss ◽  
Loss Rate ◽  
Fruit Firmness ◽  
Chromosome 10 ◽  
Physiological Basis ◽  
Water Loss Rate ◽  
Pepper Fruit ◽  
Very High

The fruit of pepper (Capsicum annuum) commonly wilts (or shrivels) during postharvest storage due to rapid water loss, a condition that greatly reduces its shelf life and market value. The fact that pepper fruit are hollow, and thus have limited water content, only exacerbates this problem in pepper. The collaborators on this project completed research whose findings provided new insight into the genetic, physiological, and biochemical basis for water loss from the fruits of pepper (Capsicum annuum and related Capsicum species). Well-defined genetic populations of pepper were used in this study, the first being a series of backcross F₁ and segregating F₂, F₃, and F₄ populations derived from two original parents selected for having dramatic differences in fruit water loss rate (very high and very low water loss). The secondly population utilized in these studies was a collection of 50 accessions representing world diversity in both species and cultivar types. We found that an unexpectedly large amount of variation was present in both fruit wax and cutin composition in these collections. In addition, our studies revealed significant correlations between the chemical composition of both the fruit cuticular waxes and cutin monomers with fruit water loss rate. Among the most significant were that high alkane content in fruit waxes conferred low fruit water loss rates and low permeability in fruit cuticles. In contrast, high amounts of terpenoids (plus steroidal compounds) were associated with very high fruit water loss and cuticle permeability. These results are consistent with our models that the simple straight chain alkanes pack closely together in the cuticle membrane and obstruct water diffusion, whereas lipids with more complex 3-dimensional structure (such as terpenoids) do not pack so closely, and thus increase the diffusion pathways. The backcross segregating populations were used to map quantitative trait loci (QTLs) associated with water loss (using DART markers, Diversity Arrays Technology LTD). These studies resulted in identification of two linked QTLs on pepper’s chromosome 10. Although the exact genetic or physiological basis for these QTLs function in water loss is unknown, the genotypic contribution in studies of near-isogenic lines selected from these backcross populations reveals a strong association between certain wax compounds, the free fatty acids and iso-alkanes. There was also a lesser association between the water loss QTLs with both fruit firmness and total soluble sugars. Results of these analyses have revealed especially strong genetic linkages between fruit water loss, cuticle composition, and two QTLs on chromosome 10. These findings lead us to further speculate that genes located at or near these QTLs have a strong influence on cuticle lipids that impact water loss rate (and possibly, whether directly or indirectly, other traits like fruit firmness and sugar content). The QTL markers identified in these studies will be valuable in the breeding programs of scientists seeking to select for low water loss, long lasting fruits, of pepper, and likely the fruits of related commodities. Further work with these newly developed genetic resources should ultimately lead to the discovery of the genes controlling these fruit characteristics, allowing for the use of transgenic breeding approaches toward the improvement of fruit postharvest shelf life.

scholarly journals Relationships between Postharvest Water Loss and Physical Properties of Pepper Fruit (Capsicum annuum L.)

HortScience ◽  
1993 ◽  
Vol 28 (12) ◽  
pp. 1182-1184 ◽  
Author(s):  
N.K. Lownds ◽  
M. Banaras ◽  
P.W. Bosland
Keyword(s):  
Physical Properties ◽  
Water Content ◽  
Surface Area ◽  
Water Loss ◽  
Loss Rate ◽  
Epicuticular Wax ◽  
Initial Water Content ◽  
Initial Water ◽  
Water Loss Rate ◽  
Wax Content

Physical characteristics [initial water content, surface area, surface area: volume (SA: V) ratio, cuticle weight, epicuticular wax content, and surface morphology] were examined to determine relationships between physical properties and water-loss `rate in pepper fruits. `Keystone', `NuMex R Naky', and `Santa Fe Grande' peppers, differing in physical characteristics, were stored at 8, 14, or 20C. Water-loss rate increased linearly with storage time at each temperature and was different for each cultivar. Water-loss rate was positively correlated with initial water content at 14 and 20C, SA: V ratio at all temperatures, and cuticle thickness at 14 and 20C. Water-loss rate was negatively correlated with surface area and epicuticular wax content at all temperatures. Stomata were absent on the fruit surface, and epicuticular wax was amorphous for each cultivar.

scholarly journals Characterization of Physiological and Biochemical Factors Associated with Postharvest Water Loss in Ripe Pepper Fruit during Storage

2005 ◽  
Vol 130 (5) ◽  
pp. 735-741 ◽  
Author(s):  
Maalekuu Kissinger ◽  
Sharon Tuvia-Alkalai ◽  
Yavin Shalom ◽  
Elazar Fallik ◽  
Yonatan Elkind ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Water Loss ◽  
Loss Rate ◽  
Lipoxygenase Activity ◽  
Ion Leakage ◽  
Factors Associated ◽  
Water Loss Rate ◽  
Pepper Fruit ◽  
Cutin Monomer ◽  
Physiological And Biochemical

Fruit of pepper (Capsicum annuum L.) is hollow by nature, which limits its water reservoir capacity, and as such, small amounts of water loss result in loss of freshness and firmness, which reduce fruit quality, shelf life, and market value. In order to understand the basis for water loss from fruit, 10 pepper accessions with wide variation in water loss rate were used to study physiological and biochemical factors associated with postharvest water loss in ripe pepper fruit during storage. Postharvest water loss rate in ripe pepper fruit stored at 20 °C, and 85% relative humidity, was found to be associated with cell membrane ion leakage, lipoxygenase activity, and total cuticular wax amount. Total cuticular wax amounts were highest in the high-water-loss pepper fruit, and lowest in the low-water-loss fruit. However, total cuticle amount (isolated enzymatically and quantified gravimetrically), total cutin monomer amount, and the amount of individual cutin monomer and wax constituents (determined using gas chromatography mass spectrometry) indicated no direct association with postharvest water loss rates. Fruit fresh weight, pericarp weight, pericarp surface area, pericarp thickness, initial water content, and dry matter were highly associated with each other, but less so with water loss rate. Fruit of accessions displaying high fruit water loss rate matured and ripened earlier than fruit of accessions displaying low-water-loss rate. Cell membrane ion leakage and lipoxygenase activity were higher after storage than immediately after harvest. Pepper fruit total cuticle wax amount, lipoxygenase activity, and cell membrane ion leakage were directly related to postharvest water loss rate in pepper fruit during storage.

Research on Shrinkage Chemical Properties of Cement Stabilized Macadam Material Based on a Multi-dimensional Expansion and Shrinkage Tester

2020 ◽  
Vol 71 (6) ◽  
pp. 418-428
Author(s):  
Aiping Fei ◽  
Wensheng Zhang ◽  
Tiezhi Zhang
Keyword(s):  
Water Loss ◽  
Room Temperature ◽  
Loss Rate ◽  
Chemical Properties ◽  
Shrinkage Strain ◽  
Fine Aggregate ◽  
Water Loss Rate ◽  
Dry Shrinkage ◽  
Reflection Crack ◽  
Shrinkage Coefficient

In order to find out the shrinkage law of cement stabilized macadam material under specific conditions, this paper studied the expansion and shrinkage properties of cement stabilized macadam material under two environmental conditions, five kinds of cement dosage conditions, suspended compacted type and skeleton compaced type based on the multi-dimensional expansion and shrinkage tester. Through the test comparison, it is confirmed that the water loss rate of cement stabilized macadam material increases with the increase of cement dosage, showing a general change rule of rising first and then stabilizing. The average increase of the total water loss rate of suspended compacted cement stabilized macadam at room temperature was greater than that of the skeleton compacted cement stabilized macadam. The dry shrinkage strain also follows the above trend. Either at room temperature or under the conditions of dry shrinkage box, the water loss rate of suspended compacted cemeny stabilized macadam is higher than that of skeleton compacted cement stabilized macadam , which can be up to 3.23% higher. By comparing the temperature shrinkage coefficient under the high and low temperature environment, the temperature coefficient of the skeleton compacted cement stabilized macadam is smaller than that of the suspended compacted cement stabilized macadam. The temperature shrinkage coefficient of the suspended compacted cement stabilized macadam increases by 5.56% on average for each 0.5% increase of the cement dosage, and the temperature shrinkage coefficient of the skeleton compacted cement stabilized macadam increases by 6.33% on average. Through the comparative analysis of tests, it can be found that the anti-reflection crack ability of the skeleton compacted cement stabilized macadam material is better, and the fine aggregate content should be strictly controlled in the construction.

Reliability of methods to determine cutaneous evaporative water loss rate in furred and fleeced mammals

2021 ◽  
Author(s):  
Vinícius de França Carvalho Fonsêca ◽  
Roberto Gomes da Silva ◽  
Gustavo A. B. Moura ◽  
Edward P. Snelling ◽  
Andrea Fuller ◽  
...  
Keyword(s):  
Water Loss ◽  
Loss Rate ◽  
Evaporative Water Loss ◽  
Evaporative Water ◽  
Water Loss Rate

The Study on Road Performance and Pavement Structure Analysis for the Base Layer Material Stabilized by SRX

2012 ◽  
Vol 594-597 ◽  
pp. 1402-1406 ◽  
Author(s):  
Yue Zhang ◽  
Yun Long Zhao ◽  
Bao Yang Yu
Keyword(s):  
Resilient Modulus ◽  
Asphalt Pavement ◽  
Base Material ◽  
Base Layer ◽  
Rigid Base ◽  
The Road ◽  
Flexible Material ◽  
Calculation Results ◽  
Road Performance ◽  
Pavement Structure

In order to overcome the weakness of semi-rigidity base layer，the road performance of the SRX(Solution Road RomixSoilfix) stabilized base material and the mechanics response of asphalt pavement with the base layer stabilized by SRX have been studied in this paper. The CBR value and resilient modulus of SRX stabilized base material were given by indoor test. Based on the multiple layer elastic theory, both the mechanical responses of asphalt pavement structure with the SRX stabilized base and semi-rigid base were given, and according to the calculation results, the two kinds of pavement structure fatigue life were analyzed. The results have shown that the CBR value of SRX flexible material is greater than that of graded crushed stone; the SRX stable material can be used as pavement base layer, but the fatigue performance of SRX flexible base materials should be paid much attention.

Sign in / Sign up

Export Citation Format

Share Document