Effect Of Initial Moisture Content Research Articles

Simultaneous effect of initial moisture content and airflow rate on biodrying of sewage sludge

The simultaneous effect of initial moisture content (initial Mc) and air-flow rate (AFR) on biodrying performance was evaluated. For the study, a 32 factorial design, whose factors were AFR (1, 2 and 3 L/min kgTS) and initial Mc (59, 68 and 78% w.b.), was used. Using energy and water mass balance the main routes of water removal, energy use and efficiencies were determined. The results show that initial Mc has a stronger effect on the biodrying than the AFR, affecting the air outlet temperature and improving the water removal, with higher maximum temperatures obtained around 68% and the lowest maximum matrix temperature obtained at initial Mc = 78%.Through the water mass balance it was found that the main mechanism for water removal was the aeration, with higher water removal at intermediate initial Mc (68%) and high AFR (3 L/min kgTS). The energy balance indicated that bioreaction is the main energy source for water evaporation, with higher energy produced at intermediate initial Mc (68%). Finally, it was found that low values of initial Mc (59%) improve biodrying efficiency.

The Effect of Initial Moisture Content on Moisture Migration in a Big Bag of Sugar in the Presence of Cyclic Temperature Changes: Numerical Analysis

The study of moisture migration in a big bag of sugar in which undergoes the fluctuation of temperature as in the shipping condition was investigated by a mathematical model. The mathematical model was derived from the conservation of mass and energy, solved by numerical method of lines, validated with the experimental data reported in the previous literature, and used to predict moisture migration for 30 days. It has revealed that the initial moisture content before shipping has the significant effect on the moisture migration. It was found that the large amount of moisture diffuses into the interfacial big bag along and the periodical adsorption and desorption takes place when the initial moisture content is high; hence, caking of moist sugar is likely to occur. The result greatly yields useful information for studying caking formation due to moisture migration.

Utilization of Fire Dynamics Simulator Model to Study Rice Husk Gasification in Fixed-bed Gasifier

Computational Fluid Dynamic (CFD) modeling applications of the biomass gasification process help to optimize the gasifier. This study aims to investigate the impact of several physical parameters on the behavior of gasification in a fixed-bed downdraft gasifier. To that end, the study presents a comparison of the results computed using the Fire Dynamics Simulator (FDS) model with experimental results of biomass gasification. Therefore, different sets of simulations and experiments have been performed to examine the effects of initial moisture content, equivalence ratio, high heating value (HHV), and cold gas efficiency (CGE). At the optimum operation, the equivalence rate is 0.3, the HHV can reach 5.71 MJ/m3, and the produced hydrogen concentration is 26.53 vol%. For an initial moisture content of 11.18%, the measured CGE is 66.85%, which is within the range of 65.07% to 70.44%. In general, the initial moisture content of the rice husks is suggested to be below 18%. The overall results indicate that the FDS model can effectively simulate and analyze gasification performance inside the gasifier, and the performance of an improved downdraft gasifier system (IDGS) is improved by higher cold gas efficiency.

Study on Crosslink Density of Natural Rubber with Different Initial Moisture Contents Dried by Microwave

In this work, the crosslink density of uncured natural rubber with different initial moisture contents, 3.80%, 10.05%, 19.76%, 23.68%, respectively, dried by microwave at frequency of 2450MHz was studied using nuclear magnetic resonance spectrometer. Seen from the results, the effect of initial moisture content of wet natural rubber on crosslink density and processability were obvious. With the increment of initial moisture content of wet natural rubber, the crosslink density of natural rubber after microwave dried with the frequency of 2450MHz decreased gradually. The crosslink density and A(Mc) of natural with the lower initial moisture content was bigger compared with natural rubber with the higher initial moisture content.

Effect of initial moisture content on the anti-swelling efficiency of thermally modified Scots pine sapwood treated in a high-pressure reactor under saturated steam

Abstract The effects of initial moisture content (MC) on anti-swelling efficiency (ASE), mass loss (ML), and equilibrium MC (EMC) at 65% relative humidity of thermally modified Scots pine sapwood under saturated steam (TMSA) has been investigated. ML during the TMSA process was higher with the specimens containing moisture before modification compared with initially dry specimens. Surprisingly, the EMC of the modified specimens with initial moisture was higher than that observed with the modified wood that was initially dry before the modification process. Higher initial MC before thermal modification results in a lower ASE.

Solid-State Bioconversion of Pineapple Residues into Kojic Acid by Aspergillus flavus: A Prospective Study

—Kojic acid is an organic acid that is widely used as an ingredient for dermatological products, precursor for flavor enhancer and also as anti-inflammatory drug. The present study was undertaken to test the feasibility of pineapple residues as substrate for kojic acid production by Aspergillus flavus Link 44-1 via solid-state fermentation. The effect of initial moisture content, pH and incubation time on kojic acid fermentation was investigated. The best initial moisture content for kojic acid production from pineapple residues was observed at 70% (v/w) whereas initial culture pH 2.5 was identified to give high production of kojic acid. The optimal range of incubation time was identified between 8 and 14 days of incubation which corresponded to highest range of kojic acid produced. The results from this study pronounce the promising usability of pineapple residues as alternative substrate for kojic acid production by A. flavus Link 44-1.

Freeze drying of quince (Cydonia oblonga): Modelling of drying kinetics and characteristics

Drying kinetics of quince (Cydonia oblonga) in mashed form was investigated in a pilot scale freeze dryer. Experiments were conducted in various operating conditions, and the effects of initial moisture content, heat load power and the initiation time of heat application were investigated on drying rate and performance of the dryer. The experimental data of the moisture changes were correlated through non-linear regression and an appropriate mathematical model was obtained. The drying kinetics of the sample was determined on the basis of the pre-identified mathematical models as a function of operating parameters. The obtained values of mean relative percent deviation for the kinetics models of the primary and secondary drying stages are 7.47% and 5.94%, respectively. It is revealed that by applying a high heat load power at the beginning of the process the drying time is reduced significantly.

Effect of initial moisture content on the in-vessel composting under air pressure of organic fraction of municipal solid waste in Morocco

This study aimed to evaluate the effect of initial moisture content on the in-vessel composting under air pressure of organic fraction of municipal solid waste in Morocco in terms of internal temperature, produced gases quantity, organic matter conversion rate, and the quality of the final composts.For this purpose, in-vessel bioreactor was designed and used to evaluate both appropriate initial air pressure and appropriate initial moisture content for the composting process. Moreover, 5 experiments were carried out within initial moisture content of 55%, 65%, 70%, 75% and 85%. The initial air pressure and the initial moisture content of the mixture showed a significant effect on the aerobic composting. The experimental results demonstrated that for composting organic waste, relatively high moisture contents are better at achieving higher temperatures and retaining them for longer times.This study suggested that an initial moisture content of around 75%, under 0.6 bar, can be considered as being suitable for efficient composting of organic fraction of municipal solid waste. These last conditions, allowed maximum value of temperature and final composting product with good physicochemical properties as well as higher organic matter degradation and higher gas production. Moreover, final compost obtained showed good maturity levels and can be used for agricultural applications.

Effect of initial moisture content on two Amazon rainforest Aspergillus strains cultivated on agro-industrial residues: Biomass-degrading enzymes production and characterization

Production of biomass-degrading enzymes using inexpensive and readily available agricultural residues as substrates for solid-state fermentation (SSF) can contribute to a broader application of enzymes for the conversion of biomass into biofuels and chemicals. Among the operational parameters that affect SSF process efficiency, moisture content is one of the most important. This work evaluates the effect of initial moisture content on two Aspergillus strains (Aspergillus niger P47C3 and Aspergillus fumigatus P40M2), isolated from the Amazon rainforest and grown under SSF. Analyses were made of the biomass-degrading enzymes produced using different agro-industrial residues as carbon sources (wheat bran, sugar cane bagasse, soybean bran, and orange bagasse). The enzymatic complex produced by a selected strain of A. fumigatus was characterized in terms of optimum pH and temperature, and thermal stability. The most effective carbon sources for multienzyme production during Aspergillus cultivation were wheat and soybean bran, as well as a 1:1 mixture of sugar cane bagasse and wheat bran. Much higher activity values were achieved for β-glucosidase (105.8IU/g) and xylanase (1055.6IU/g) when wheat bran with 50% initial moisture content was used as substrate. Under this condition, endoglucanase and total cellulase activity values were 56.6IU/g and 5.0FPU/g, respectively. Characterization of the crude enzymatic complex showed that the A. fumigatus P40M2 enzymes were active in the acidic pH range, with maximal activities at the range of 50–65°C, demonstrating the potential of the organism for the production of acidophilic and thermophilic biomass-degrading enzymes.

The nutritive value of maize cultivars for broiler chickens

1. In vitro and in vivo assessment of the effect of initial moisture content and drying temperature on the feeding value of maize grain F. Huart, P. Malumba, S. Odjo, W. Al-Izzi, F. Béra, Y. Beckers British Poultry Science CrossRef

CONTROL OF SWELLING OF SOIL UNDER CANAL LINING BY WETTING AND DRYING CYCLES

ABSTRACTIn the present research, the effects of cyclic wetting and drying on the swelling potential of clayey soils were investigated. For this purpose, three different clayey samples were collected from three irrigation project sites in Iran. The swelling tests were conducted in oedometer cells, where percent swell was measured in five wetting and drying cycles. To investigate the effects of initial moisture content of the soil on swell potential, the samples were tested at moisture contents at, below and above the shrinkage limit. The results of the experiments showed that for all samples, no matter at what the initial moisture content tested, swelling potential was considerably reduced as a result of the wetting and drying cycles. For some samples, maximum reduction in swelling was observed in the second cycle, while for others it occurred in the third or fourth cycle. Copyright © 2012 John Wiley & Sons, Ltd.

Microwave drying of planks of Grevillea robusta A. Cunn. ex R

Drying of wood has become one of the most important aspects in modern wood industry scenario as it improves the quality of wood by many folds. Different methods have been tried to dry wood. Microwave drying is one of the most efficient methods of drying materials. In this study, drying behaviour of silver oak wood (Grevillea robusta) planks using a 2.4 kW intensity microwave dryer is presented. Effect of microwave time, auxiliary heating, plank thickness is studied to assess drying rate and any defects arising due to microwave heating. The amount of water lost increased linearly with microwave exposure time. On an average, moisture loss rate was about 13 g/min at 2 kW microwave power. There was no significant effect of initial moisture content on moisture loss rate from wood. Auxiliary heating was found to aid in accelerating drying rate however it also contributed substantially in energy consumption during drying. Thicker sections of wood exhibited slightly slower drying than thinner sections. Wood exposed to microwave for different period did not exhibit any remarkable difference in their subsequent air-drying rate.

The Drying Characteristic of Biomass with High Moisture Content

This paper presents the drying characteristics of rice husk and cornstalk with high moisture content at fixed temperatures. Experiments were performed in an oven drier, to reveal to the effects of initial moisture content, bed thickness and drying temperature on the biomass drying characteristics. The results indicated that the drying time was decreased as the rising of the drying temperature, and increased along with the initial moisture content and bed thickness. Moreover, the risk husk was easy to be dried than the cornstalk.

Delivery of entomopathogenic nematodes directly through commercial growing media via the inclusion of infected host cadavers: A novel approach

To assess the potential for marketing pre-amended plant growing media, we compared survival of the entomopathogenic nematodes, Steinernema carpocapsae, delivered via Galleria mellonella and Tenebrio molitor cadavers in the Scotts commercial growing medium, Miracle-Gro®. Six pouches, each filled with 10 g of the growing medium containing 6 nematode-infected cadavers of either insect species were placed in each 1 kg Miracle-Gro® bag. The nematode survival was assessed in the cadavers, pouches and the bags. Although, overall survival of S. carpocapsae declined within 90 days in both cadaver types, survival was significantly higher in G. mellonella than T. molitor cadavers at 15, 45, 60 and 90 days most likely due to the higher reproduction in G. mellonella cadavers. Similarly, survival (assessed as the number of baited G. mellonella killed) remained consistently higher both in the pouches and bags in the G. mellonella cadaver treatment compared to the T. molitor treatment. In another experiment in which bags were not opened until 180 days, all G. mellonella cadavers disintegrated within 180 days of storage; however, the number of baited G. mellonella larvae killed in the pouch was similar in both the cadaver treatments indicating equal number of surviving nematodes. Further, we evaluated the effect of initial moisture content of the growing medium on the survival and virulence of nematodes when delivered through cadavers and aqueous suspension. The results showed that survival and virulence of S. carpocapsae was higher in G. mellonella cadaver treatment than in the aqueous suspension treatment at all sampling times, and reducing the initial moisture content of the medium from 50% to 20–30% enhanced nematode survival in the medium. This is the first report demonstrating the possibility of directly delivering entomopathogenic nematodes through commercial growing medium via infected insect cadavers, a method in which nematode survival could be further enhanced by reducing the initial moisture content of the growing medium.

Effects of moisture content and heat treatment on peroxide value and oxidative stability of un-refined sesame oil

Sesame (Sesamum indicum L) is one of the oldest cultivated plants. Its seed contains about 42-54 % quality oil, 22-25 % protein, 20-25 % carbohydrates and 4-6% ash. This composition varies with genetic and environmental factors. Conditioning of oil seeds which include roasting, flaking, size reduction, cooking, pre-pressing and drying, is an important operation in the production line of sesame oil. This work investigated effects of initial moisture content, roasting duration and temperature on initial Peroxide Value (PV) and Oxidative Stability (OS) of un-refined sesame oil using response surface methodology. Goza-25, a variety of sesame seed that is commercially cultivated in Nigeria was used for the study. Initial moisture content levels were 4, 7, 10, 13 and 16 % wet basis (wb). Roasting duration and temperature levels were 5, 10, 15, 20 and 25 minutes, and 50, 70, 90, 110 and 130 oC respectively. The recorded minimum and maximum PV were 3.9 and 15.4 meq/kg respectively. Mean value was 9.85 ± 3.9 meq/kg. Peroxide value increased with increasingmoisture content and reduced with increasing roasting duration. Analysis of variance and regression analysis of obtained data showed that application of quadratic model to predict effect of initial moisture content, roasting duration and temperature on peroxide value is significant at p ≤ 0.05. Within the studied range, 13 h was the minimum OS recorded while maximum were 63.3 h. Mean of the data was 38.37 ± 16.02. Using the conversion factor of one hour of an active oxygen hour as being equivalent to 15 days; the expressed sesame oil in its present form will retain its quality for a maximum period of 949 days. Rise in roasting temperature and duration increased the oxidative stability, a reverse was observed with initial moisture content. High moisture content reduced the quality and storage life while heat treatment increased both the initial quality and storage life of the mechanically expressed oil. Peroxide value and oxidative stability of crude sesame oil significantly (p ≤ 0.05) depend on moisture content of the seed, roasting duration and temperature.Key words: Sesame, Oil, Crude, Oxidation, Storage

Moisture diffusivity of rough rice under infrared radiation drying

To design efficient infrared (IR) dryers for rough rice, it is important to understand the drying behavior of rough rice under IR heating. The objective of this study was to determine the moisture diffusivity of rough rice under IR heating followed by cooling. The effects of initial moisture content, rice temperature, drying bed thickness, tempering, and cooling methods on moisture diffusivity and moisture diffusivity coefficient were investigated. Samples of freshly harvested medium grain rice (M202 variety) with initial moisture content (MC) of 25.8, 31.2 and 33.8 g moisture/100 g dry solid were used. They were dried with IR radiation intensity of 5348 W/m 2, for six exposure times, 15, 30, 40, 60, 90 and 120 s. The tested drying bed thicknesses were single-layer, 5 mm and 10 mm. The unsteady diffusion equation based on Fick’s law and slope methods were used to describe moisture diffusivity. The results indicated that rough rice moisture diffusivities under IR heating and cooling were significantly affected by rice temperature and tempering treatment, respectively. High heating rate and moisture diffusivity were achieved with IR heating. It took only 60, 90 and 120 s to achieve about 60 °C rice temperature with corresponding moisture diffusivities of 4.8 × 10 −9, 3.6 × 10 −9 and 3.4 × 10 −9 m 2/s during heating for drying bed thicknesses of a single layer, 5 mm and 10 mm, respectively. The moisture diffusivity coefficients during heating and cooling of IR dried rice with tempering were much higher than those of convective drying, which reflected the high drying rate of the IR drying method.

The Effect of Initial Moisture Content, Packaging and Storage Period on Succinate Dehydrogenase and Cytochrome Oxidase Activity of Soybean Seed

The quality of soybean seed is easily decreased, so that it is difficult to keep them for a long time. The research aims to study the effect of initial moisture content, packaging material and storage period on succinate dehydrogenase and cytochrome oxidase activity. The experimental design was arranged in Factorial in RCB consisting of 3 factors: moisture content, i.e. 8. 10 and 12 percent, packaging materials, i.e. polyethylene, wheat and aluminium foil; storage period i.e. 0, 1, 2, 3, 4, 5, and 6 months. Changes in seed water content, specific activity of succinate and cytochrome oxidase, respiration rate, germination coefficient velocity germination, and abnormal seedlings were monthly determined. It was found that seed moisture content was increase and showed positive correlation with seed moisture content and abnormal seedlings and showed negative correlation with specific activity of succinate dehydrogenase and cytochrome oxidase, respiratory rate, germination and coefficient velocity germination. From this experiment, soybean seeds were stored in polyethylene and aluminium foil bags observed highly succinate dehydrogenase and cytochrome oxidase specific activity, respiration rate, germination, coefficient velocity germination and keep moisture content in low level could delay seed deterioration followed by polyethylene and wheat bags. Key words: moisture content, succinate dehydrogenase, cytochrome oxidase, soybean

Penetrability of lightweight aggregate concrete

In this paper, a study was conducted on the parameters affecting the sorption of water, chloride ingress and permeability of water into lightweight aggregate concrete. The parameters being studied are the effects of the water-to-cement (w/c) ratio, aggregate type, initial moisture content of the lightweight aggregate, size of the lightweight aggregate, density of the lightweight aggregate, cement paste volume and volume of the lightweight aggregate. Experimental programmes were designed to look into the effects of these parameters on the penetration of water and free chloride ions into lightweight aggregate concrete by water sorption under capillary action in unsaturated concrete, chloride diffusion under a constant concentration gradient, and water permeability under a constant pressure gradient. From this research, it was found that variations in the w/c ratio, cement paste volume, as well as size, density and volume of the lightweight aggregate, have reasonable effects on penetrability properties of lightweight aggregate concrete. The effect of initial moisture content in the lightweight aggregate on properties of lightweight aggregate concrete is not obvious from this research.

Optimising microwave vacuum puffing for blue honeysuckle snacks

AbstractFresh blue honeysuckle fruit slices were puffed in a microwave vacuum dryer up to a final moisture content about 5% (w.b.). The effect of initial moisture content (IMC) (25–45%), vacuum pressure (VP) (70–90 kPa) and microwave intensity (MI) (10–30 W g−1) on quality attributes, in terms of expansion ratio (ER), hardness (HD), crispness (CR) and colour of the products, were analysed by response surface methodology. Besides the effect of MI on chroma (CH), the high IMC and low VP had a significantly positive impact on the quality attributes of blue honeysuckle snacks. The optimum product qualities, which were ER (1.62 times), HD (5836.31 g), CR (4.48), and CH (28.7) were obtained at an IMC of 38.42%, VP of 82.02 kPa, and MI of 22.42 W g−1. The microwave vacuum method has obvious advantages when puffing the blue honeysuckle snacks.

Influence of initial moisture content on the composting of poultry manure with wheat straw

The effect of initial moisture content (MC) on the composting of poultry manure with wheat straw in terms of the temperature of the compost, its emission of carbon dioxide and ammonia, and the rate of conversion of organic matter were investigated. Three experiments were carried out in closed laboratory-scale reactors under adiabatic conditions. The initial MC of the mixture of poultry manure and wheat straw showed a significant effect on aerobic composting process. The results demonstrated that for composting poultry manure with wheat straw, relatively high MCs are better at achieving higher temperatures and retaining them for longer times. However, high MCs can lead to increased losses of ammonia, which need be controlled by the addition of suitable additives. The results of this study suggest that an initial MC of around 69% can be considered as being suitable for the efficient composting of poultry manure mixed with wheat straw.