Rehydration Kinetics of Dried Spaghetti with Different Diameters

Changes in bud moisture content were studied in northern Wisconsin during 1963, from mid-April until bud opening, in Betula papyrifera Marsh., Acer saccharum Marsh., Tilia americana L., Quercus rubra L., Pinus strobus L., Pinus resinosa Ait., and Tsuga canadensis (L.) Carr. Changes in leaf moisture contents and leaf dry weights were studied throughout the 1963 growing season for the above species and for Abies balsamea (L.) Mill. In gymnosperms zero-age (current) needles and 1-year-old needles were studied separately. A similar study of changes in moisture content and dry weight of leaves of Quercus ellipsoidalis Hill was performed in the greenhouse. Moisture contents (% dry weight) of buds of angiosperms and gymnosperms increased progressively from early May until buds opened. The increase in moisture content was traceable primarily to rapid translocation of moisture into the buds. Moisture contents of angiosperm leaves decreased rapidly in the early part of the growing season and slowly after midsummer. The seasonal decrease was traceable primarily to greater increase in leaf dry weight than to decrease in actual water content. In fact, early in the season moisture content, as % dry weight, decreased rapidly while the actual amount of water in the expanding leaves increased. The rate of increase in leaf dry weight exceeded the rate of water uptake for the same period. In most angiosperms the actual amount of water in the foliage changed little from mid-June to the end of the season. The seasonal trend in moisture content of gymnosperm leaves varied with age. In current-year needles the moisture content declined progressively, while in 1-year-old needles it increased at first and then tended to level off. These differences were caused largely by dry weight changes resulting from rapid carbohydrate translocation into current-year needles and some translocation out of the older needles. These experiments emphasized that changes in moisture content (% oven-dry weight) often occur without appreciable changes in actual water content of tissues.

Drip irrigation strategy for tomatoes grown in greenhouse on the basis of fuzzy Borda and K-means analysis method

121 Impact of environmental conditions and dragging schedules on changes in moisture content in equine arena footing

Seasonal variations in climatic conditions have long been recognized to have a significant impact on the structural response of flexible pavements. Of particular significance is the effect of subgrade moisture content on subgrade support values and potential roadway damage. The Montana Department of Transportation is conducting a project to evaluate the response of subgrade resilient modulus to seasonal changes in subgrade moisture content. Moisture content is being measured through permanent subsurface instrumentation while deflection tests are periodically being conducted to establish subgrade resilient modulus values. This report describes work performed in support of this project. The purpose of this study was to provide laboratory data on subgrade support values for the instrumented sites. These data will illustrate the variation in subgrade support with changes in moisture content and sample dry density. This information will be used to verify the accuracy of the data generated in the field and might also be used to help guide the backcalcuation procedure. Laboratory testing has consisted of resilient modulus, triaxial compression, CBR and R-Value tests. Results have been generated for various combinations of sample dry density and degree of saturation. These results have been related to resilient modulus whenever possible. The results tend to show that ultimate strength related parameters are most sensitive to changes in dry density and moisture content for the cohesive subgrade soils and that deformation related parameters are most sensitive for the more non-cohesive subgrade soils.

BackgroundForest fire risk predictions are based on the most conservation daily predictions, and the lowest litter moisture content of each day is often used to predict the day’s fire risk. Yunnan Province is the area with the most frequent and serious forest fires in China, but there is almost no research on the dynamic changes and model predictions of the litter moisture content in this area. Therefore, to reduce the occurrence of forest fires and improve the accuracy of forest fire risk predictions, it is necessary to understand these dynamic changes and establish an appropriate prediction model for the typical litter moisture content in Yunnan Province.MethodDuring the fire prevention period, daily dynamic changes in the litter moisture content are obtained by monitoring the daily step size, and the relationships between the litter moisture content and meteorological elements are analyzed. In this study, the meteorological element regression method, moisture code method and direction estimation method are selected to establish litter moisture content prediction models, and the applicability of each model is analyzed.ResultsWe found that dynamic changes in the litter moisture content have obvious lags compared with meteorological elements, and the litter moisture content is mainly related to the air temperature, relative humidity and wind speed. With an increase in the sampling interval of meteorological elements, the significances of these correlations first increase and then decrease. The moisture content value obtained by directly using the moisture code method in the Fire Weather Index (FWI) significantly different from the measured value, so this method is not applicable. The mean absolute error (MAE) and mean relative error (MRE) values obtained with the meteorological element regression method are 2.97% and 14.06%, those from the moisture code method are 3.27% and 14.07%, and those from the direct estimation method are 2.82% and 12.76%, respectively.ConclusionsThe direct estimation method has the lowest error and the strongest extrapolation ability; this method can meet the needs of daily fire forecasting. Therefore, it is feasible to use the direct estimation method to predict litter moisture contents in Yunnan Province.

Degradation of Wood

The change in the maize moisture content during different growth stages is an important indicator to evaluate the growth status of maize. In particular, the moisture content during the grain-filling stage reflects the grain quality and maturity and it can also be used as an important indicator for breeding and seed selection. At present, the drying method is usually used to calculate the moisture content and the dehydration rate at the grain-filling stage, however, it requires large sample size and long test time. In order to monitor the change in the moisture content at the maize grain-filling stage using small sample set, the Bootstrap re-sampling strategy-sample set partitioning based on joint x-y distances-partial least squares (Bootstrap-SPXY-PLS) moisture content monitoring model and near-infrared spectroscopy for small sample sizes of 10, 20, and 50 were used. To improve the prediction accuracy of the model, the optimal number of factors of the model was determined and the comprehensive evaluation thresholds RVP (coefficient of determination (R2), the root mean square error of cross-validation (RMSECV) and the root mean square error of prediction (RMSEP)) was proposed for sub-model screening. The model exhibited a good performance for predicting the moisture content of the maize grain at the filling stage for small sample set. For the sample sizes of 20 and 50, the R2 values were greater than 0.99. The average deviations of the predicted and reference values of the model were 0.1078%, 0.057%, and 0.0918%, respectively. Therefore, the model was effective for monitoring the moisture content at the grain-filling stage for a small sample size. The method is also suitable for the quantitative analysis of different concentrations using near-infrared spectroscopy and small sample size. Keywords: moisture content monitoring, maize, growth stage, near-infrared spectroscopy (NIRS), small sample set, model screening, optimal factor number, Bootstrap-SPXY-PLS DOI: 10.25165/j.ijabe.20191202.4708 Citation: Wang X, Ma T M, Yang T, Song P, Chen Z G, Xie H. Monitoring model for predicting maize grain moisture at the filling stage using NIRS and a small sample size. Int J Agric & Biol Eng, 2019; 12(2): 132–140.

Time Domain Reflectometry (TDR) has been used since the 1980s for measuring the moisture content of soils. The principle of TDR is based on measuring the reflection time of an electromagnetic signal sent down a set of waveguides that are inserted into the material. This paper reports research work examining the suitability of TDR for measuring the moisture content of building materials. Results suggest that TDR is an effective way of monitoring relative changes in the moisture content. Measurement of absolute moisture content is more complicated as it requires a calibration function, and the existing empirical relationships used in the soil sciences consistently overestimate the moisture content. A semi-empirical calibration relationship has been found to offer a better approach to absolute moisture content evaluation with TDR. Practical application: This paper reports research work examining the suitability of TDR for application to the measurement of the moisture content of building materials. It finds that TDR can rapidly identify changes in the relative moisture content and may therefore be suited to monitoring the long-term moisture behaviour of a building material in situ. Application of the technique to the measurement of the absolute moisture content is more difficult; further work is needed to address the accuracy of absolute measurements.

The subject of this paper is the analysis of moisture content (MC) changes of beech and ash wood during two years in room conditions (heating during winter; no air conditioning during summer). The registered MC changes are primarily the result of changes in relative humidity of the air (measured by capacitive probes). The average relative humidity of the air in the interior is lower today than in the past, as also shown in this experiment (the average relative humidity of air during two years was 44%). The lowest wood MC was reached on very cold winter days when the heating was on even during the night - between 5% and 6%, and the highest one at the beginning of June: 10.4-10.9%. As expected, the wood did not reach equilibrium moisture content - during winter, MC is by about 1% higher, and in summer it is lower by up to 2.5% than the equilibrium. The recommendation that the sawn timber from which the interior products will be made should be dried at 7-8% MC was confirmed.

A study was carried out to test and evaluate a portable mechanical date dryer using butane – gas as heat energy source. The temperature of drying air was adjusted to be approximately constant during the experiment of period at 40 , 50 , 60 and 70°C and air velocity of 1 ,1.5 and 2 m/s. Two empirical models (Exponential and Page) were examined to describe the drying behaviour of date. The change in date moisture content during the drying process, thermal efficiency of the drying process and the total and reducing sugars of the dried date were also determined. The obtained results showed that, both of the examined models could satisfactory describe the change in date moisture content during the drying process. While the Page's model could predict the change in moisture content of date more adequately than the simple model. The dryer thermal efficiency increased with the increase of drying air temperature and air velocity, and it ranged from 32.23 to 69.84 % for the un-peeled date, from 33.82 to 71.63% for the un-peeled treated date and from 35.42 to 75.13% for the peeled date. Also, the total and reducing sugars percentages decreased with the decrease of drying air temperature and air velocity and the reducing sugar ranged from 44.85 to 51.38 % while the total soluble sugar ranged from 55.95 to 65.14 % .

The objective of the work reported here was to determine changes in the moisture content, firmness characteristics, color attributes and NIR absorbance of two carrot cultivars during storage. There was a definite loss in the moisture content that caused changes in the firmness. This result shows that carrot firmness is very sensitive to the moisture content. The firmness — especially the cutting force — is a good characteristic for predicting changes in carrot moisture content during storage. The color characteristics — a* and b* — showed a slight change in the function of the moisture content. However, these color characteristics are suitable for distinguishing the phloem and xylem parts of carrot cultivars. There were not found definite changes in the NIR absorbance as the function of the moisture content. Consequently, the specific cutting force and the impact stiffness coefficient are good characteristics of the carrot moisture content and the mass reduction during storage under non-ideal conditions.

Parboiling process of black rice could reduce cooking time and improve texture. However, parboiling process involving heat had the potency to affect moisture content, total phenolic content (TPC), and pasting profile. The aim of this research was to find the effect of parboiling process in the moisture content, TPC and pasting profile of black rice. There were three kinds of black rice. That was parboiled black rice A (3.8% concentration of sodium citrate, 5-minute steaming time, and 3.8 times freezing-thawing cycles), parboiled black rice B (5% concentration of sodium citrate, 15-minute steaming time, and 4 times freezing-thawing cycles) and normal black rice. Analysis of variance (α=5%) showed that there was a significant difference in moisture content and TPC parameter. The changes of black rice moisture content and total phenolic content caused by parboiling process A were bigger than B. Measurement of pasting profile explained that parboiled black rice A and B had lower pasting profile than normal black rice.

Dehydration–rehydration vegetables: Evaluation and future challenges

In modern fruit processing technology, non-destructive quality measuring techniques are sought for determining and controlling changes in the optical, structural, and chemical properties of the products. In this context, changes inside the product can be measured during processing. Especially for industrial use, fast, precise, but robust methods are particularly important to obtain high-quality products. In this work, a newly developed multi-spectral imaging system was implemented and adapted for drying processes. Further it was investigated if the system could be used to link changes in the surface spectral reflectance during mango drying with changes in moisture content and contents of chemical components. This was achieved by recovering the spectral reflectance from multi-spectral image data and comparing the spectral changes with changes of the total soluble solids (TSS), pH-value and the relative moisture content xwb of the products. In a first step, the camera was modified to be used in drying, then the changes in the spectra and quality criteria during mango drying were measured. For this, mango slices were dried at air temperatures of 40–80 °C and relative air humidities of 5%–30%. Samples were analyzed and pictures were taken with the multi-spectral imaging system. The quality criteria were then predicted from spectral data. It could be shown that the newly developed multi-spectral imaging system can be used for quality control in fruit drying. There are strong indications as well, that it can be employed for the prediction of chemical quality criteria of mangoes during drying. This way, quality changes can be monitored inline during the process using only one single measuring device.

This study investigated the crack propagation law of expansive soil slopes under drying–wetting conditions and the influence of cracks on slopes by conducting a large-scale indoor slope test subjected to drying–wetting cycles. The change in soil moisture content at different depths during the drying–wetting cycles was monitored using a moisture content sensor, and the variation in crack depths in the expansive soil during the drying process was measured using a crack depth detector. The cracks on the slope’s surface were processed using a self-made binarization program, and the crack evolution mechanism of the expansive soil during the drying process was analyzed. The rainfall-induced change in moisture content in the fractured soil was used to obtain the influence of moisture content change on expansive soils, and to analyze the dry–wet cycle failure mode of surface soil. The surface cracks of the soil were quantified by binary processing, and the area of the cracks and the area ratio of cracked soil to intact soil were calculated. Finally, by using PFC simulation software with the slope cracks and quantitative analysis results as parameters, it was confirmed that the greater the number of drying–wetting cycles, the greater the number of cracks, and the greater the damage to the slope.