Monitoring of drying-induced soil moisture loss with PZT-based EMI technique

Air-drying process of soil is a crucial procedure in geological and geotechnical engineering. Drying-induced ground subsidence and damage to overlying buildings is a widespread and urgent problem. Monitoring of drying-induced water evaporation in soil is of great importance. In this paper, soil moisture loss monitoring based on lead zirconate titanate (PZT) transducer using electro-mechanical impedance (EMI) technique was investigated. A physical model test in our laboratory was conducted to study the feasibility and applicability. In the experimental research, three identical PZT transducers that were wrapped with waterproof insulation glue were pre-embedded inside a cohesive soil specimen. In addition, another PZT transducer was embedded in a sandy soil specimen to explore the application effect in soil with different composition. EMI signatures of these four PZT patches during the air-drying process were collected and analyzed. Experimental results indicated that the peak frequency in the conductance signatures presented a rightward shift as the water evaporates. Moreover, the corresponding peak magnitude keep decreasing with the continuous development of soil moisture loss. To better quantify the variations, two statistical metrics including root mean square deviation (RMSD) and mean absolute percentage deviation (MAPD) were employed to study the changing characteristics of the EMI signatures. All these two metrics increase coincidentally in the process. Experimental results demonstrate that cohesive and sandy soil moisture loss monitoring by using the embedded PZT transducer is feasible and reliable. This work also serves as a proof-of-concept study to demonstrate the performance of the EMI technique in monitoring the soil moisture content.

Property Evaluation of Cement-Stabilized Macadam Modified via Phosphorus Slag Materials

Phosphorus slag, known as the waste product of the phosphate ore industry, is causing critical environmental issues due to its direct exposure to natural spaces. In this article, a partial replacement of the natural fine aggregate ordinarily used in cement-stabilized macadam (CSM) base by phosphorus slag was explored to be an effective solution for phosphorus slag waste. CSM specimens were fabricated by adding various dosages of phosphorus slag particle and fine powder, whereas the optimum moisture content and maximum dry density were analyzed through compaction tests. Compressive strength, bending tensile strength, fatigue life span, dry shrinkage, and temperature shrinkage performance at different curing durations were investigated to evaluate the properties of modified macadam. Results show that phosphorus slag reduced the early compressive strength of CSM to a small extent, but the compressive strength finally increased at 90 days’ curing. The modified slag particles and slag fine powder exhibited different behaviors to repeated loading, moisture loss, and temperature difference. Finally, according to the strength change, fatigue performance comparison, and shrinkage strain caused by the incorporation of phosphorous slag materials into the CSM, it was verified that 25% of the particles to 40% of the fine powder is the best replacement ratio.

Influence of sample preparation process on basic properties of biofuels

The characteristic properties of non-wood biomass used in combustion processes are monitored, such as water content, ash, volatile matter. Biomass is usually not homogenous and of suitable dimensions for these determinations. This is the reason for the necessary adjustment of samples for analysis. But modifying the samples may change their properties. In this publication, the influence of the grinding process in a rotor mill on the content of water, volatile matter and ash in non-wood biomass samples was studied. Samples of flax, Crambe abyssinica, amaranth and rye were analyzed. All analyses showed moisture loss from the sample during grinding and in the case of flax, the loss of volatile matter was observed. It means the rotor mill is suitable for sample preparation prior to analysis. But for oil plants it is necessary to choose another mill or adjustment method.

Theoretical and experimental study of the influence of temperature, humidity and density on the processes of drying, cleaning and filtration of cotton raw materials

The article presents information about existing problems and their solutions in the process of drying cotton raw materials at cotton gin plants, patterns of changes in the humidity of cotton raw materials at different values of the warm air velocity are obtained. The influence of the density of cotton raw materials and the relative air velocity on the change in the moisture loss coefficient at different temperatures of the air flow was investigated and it was established using a laboratory device that at a density of 0.5 g/cm3, the moisture loss process in cotton raw materials.

Improving the Storage Quality of Eggplants (Solanum Aethiopicum L.) Fruit using Aloe Vera Gel Coating

Aloe vera gel has been investigated as possible edible coating to help improve the storage life of fruits after harvest. The study sought to investigate the effect Aloe vera gel coating with or without citric acid pretreatment on the quality of eggplant fruits during low temperature storage and in shelf life. Briefly, eggplants were coated with Aloe vera gel (some fruits were pretreated with citrate prior to the coating) and the changes in physicochemical quality of the fruit measured during storage at 10 °C. After 14 days, however, some fruits were transferred for storage at room temperature until day 18. Coating with Aloe vera decreased moisture loss, and consequently, decreased weight loss and loss of firmness of the fruit. The coating did help maintain the phenolic content, ascorbate levels and antioxidant capacity of the fruit. Pre-treating the fruit with citrate did not improve quality, showing that Aloe vera gel can be applied alone to enhance the storage quality of eggplant fruit. Results obtained from this study shows that Aloe vera gel coating can be useful in extending the postharvest storage life and maintaining the quality of eggplant fruits during low temperature storage.

Polysaccharide-Based Active Coatings Incorporated with Bioactive Compounds for Reducing Postharvest Losses of Fresh Fruits

This review reports recently published research related to the application of polysaccharide-based biodegradable and edible coatings (BECs) fortified with bioactive compounds obtained from plant essential oils (EOs) and phenolic compounds of plant extracts. Combinations of polysaccharides such as starches, pectin, alginate, cellulose derivatives, and chitosan with active compounds obtained from clove, lemon, cinnamon, lavender, oregano, and peppermint have been documented as potential candidates for biologically active coating materials for retardation of quality changes in fresh fruits. Additionally, polysaccharide-based active coatings supplemented with plant extracts such as cashew leaves, pomegranate peel, red roselle, apple fiber, and green tea extracts rich in phenolic compounds and their derivatives have been reported to be excellent substituents to replace chemically formulated wax coatings. Moreover, EOs and plant polyphenolics including alcohols, aldehydes, ketones phenols, organic acids, terpenes, and esters contain hydroxyl functional groups that contribute bioactivity to BECs against oxidation and reduction of microbial load in fresh fruits. Therefore, BECs enriched with active compounds from EOs and plant extracts minimize physiological and microbial deterioration by reducing moisture loss, softening of flesh, ripening, and decay caused by pathogenic bacterial strains, mold, or yeast rots, respectively. As a result, shelf life of fresh fruits can be extended by employing active polysaccharide coatings supplemented with EOs and plant extracts prior to postharvest storage.

The increasing role of vegetation transpiration in soil moisture loss across China under global warming

Changing pathways of soil moisture loss, either directly from soil (evaporation) or indirectly through vegetation (transpiration), are an indicator of ecosystem and land hydrological cycle responses to the changing climate. Based on the ratio of transpiration to evaporation, this paper investigates soil moisture loss pathway changes across China using five reanalysis-type datasets for the past and Coupled Model Intercomparison Project Phase 6 (CMIP6) climate projections for the future. The results show that across China, the ratio of vegetation transpiration to soil evaporation has generally increased across vegetated land areas, except in grasslands and croplands in North China. During 1981–2014, there was an increase by 51.4 percentage points (pps, p < 0.01) on average according to the reanalyses and by 42.7 pps according to 13 CMIP6 models. The CMIP6 projections suggest that the holistic increasing trend will continue into the 21st century at a rate of 40.8 pps for SSP585, 30.6 pps for SSP245, and –1.0 pps for SSP126 shared socioeconomic pathway scenarios for the period 2015–2100 relative to 1981–2014. Major contributions come from the increases in vegetation transpiration over the semiarid and subhumid grasslands, croplands, and forestlands under the influence of increasing temperatures and prolonged growing seasons (with twin peaks in May and October). The future increasing vegetation transpiration ratio in soil moisture loss implies the potential of regional greening across China under global warming and the risks of intensifying land surface dryness and altering the coupling between soil moisture and climate in regions with water-limited ecosystems.

Chitosan Reinforced with Kenaf Nanocrystalline Cellulose as an Effective Carrier for the Delivery of Platelet Lysate in the Acceleration of Wound Healing

The clinical use of platelet lysate (PL) in the treatment of wounds is limited by its rapid degradation by proteases at the tissue site. This research aims to develop a chitosan (CS) and kenaf nanocrystalline cellulose (NCC) hydrogel composite, which intend to stabilize PL and control its release onto the wound site for prolonged action. NCC was synthesized from raw kenaf bast fibers and incorporated into the CS hydrogel. The physicochemical properties, in vitro cytocompatibility, cell proliferation, wound scratch assay, PL release, and CS stabilizing effect of the hydrogel composites were analyzed. The study of swelling ratio (>1000%) and moisture loss (60–90%) showed the excellent water retention capacity of the CS-NCC-PL hydrogels as compared with the commercial product. In vitro release PL study (flux = 0.165 mg/cm2/h) indicated that NCC act as a nanofiller and provided the sustained release of PL compared with the CS hydrogel alone. The CS also showed the protective effect of growth factor (GF) present in PL, thereby promoting fast wound healing via the formulation. The CS-NCC hydrogels also augmented fibroblast proliferation in vitro and enhanced wound closures over 72 h. This study provides a new insight on CS with renewable source kenaf NCC as a nanofiller as a potential autologous PL wound therapy.

A climatological study of soil moisture under corn crop at Campina Grande (NE Brazil)

ABSTRACT. Results of a climatological study of soil moisture under corn crop at Campina Grande (NE Brazil) are presented in this paper. Daily values of available moisture content during the crop growing period are evaluated for a period of 25 years. A six zone versatile soil moisture budget model is used for this purpose and approximately 5. 7.5, 12.5, 25, 25 and 25% of the available water capacity (AWC) are attributed to zones one to six respectively. Different root activity coefficients are assumed for the six zones in different growth stages and the dependence of these coefficients on moisture content is taken into consideration. The same moisture releasing characteristics are assumed for all soil zones. On rainy days moisture loss due to evapotranspiration is assumed to take place before precipitation. Four AWC values and three corn growing periods between March and September are considered in this study. A first order Markov chain model is applied to the daily soil moisture data. Soil moisture averages and probabilities are used to identify the optimum growing period for corn at this station. The irrigation requirements of the crop are briefly discussed.