Constant Moisture Content Research Articles

Short Communication: Visual assessment, proximate composition and cost analysis of three differently processed discarded vegetable-bovine blood-rumen content mixtures

With increased search for least-cost alternative feed resource in animal production, this study was conducted to determine the visual properties, chemical composition and cost analysis of three differently processed discarded vegetable-bovine blood-rumen content mixture as potential alternative feed resource. These mixtures were obtained by mixing whole bovine blood, discarded vegetable and rumen content at ratio 1:1:1 under different processing methods. The processed mixtures obtained were in three categories: discarded vegetable-fresh bovine blood-fresh rumen digesta (D1), discarded vegetable-ensiled bovine blood-fresh rumen digesta (D2) and discarded vegetable-fresh bovine blood-ensiled rumen digesta (D3). The mixtures were cooked and sun-dried to constant moisture content and thereafter were subjected to particle size reduction. Chemical composition of the products indicated a good potential nutritional quality with metabolizable energy and crude protein contents ranging from 9.66 to 10.49 MJ/kg and 40.79 to 50.21, respectively. Crude fibre concentrations were relatively low (8.39-13.14) for most of the products compared to conventional protein sources. Visual assessment of processed mixtures revealed D1 to be brownish in colour while D2 and D3 tend towards grey. In terms of odour, all three test mixtures were strongly pungent. Processed mixture D1 had an intermediate texture (it was neither finely ground nor coarse) where D2 and D3 had a finely ground texture. Cost analysis revealed a lower production cost for the three processed mixtures indicating its adequacy to replace soybean and other plant and animal protein sources in terms of their cost/kg inclusion in diet. Processed mixtures can serve as suitable replacements for soybean meal in terms of chemical constituents and reduced cost/kg feed for animal. Keywords: Bovine blood, rumen digesta, discarded vegetable, visual assessment, proximate composition, cost analysis.

Foundation heat exchangers for residential ground source heat pump systems—Numerical modeling and experimental validation

A new type of ground heat exchanger that utilizes the excavation often made for basements or foundations has been proposed as an alternative to conventional ground heat exchangers. This article describes a numerical model that can be used to size these foundation heat exchanger (FHX) systems. The numerical model is a two-dimensional finite-volume model that considers a wide variety of factors, such as soil freezing and evapotranspiration. The FHX numerical model is validated with one year of experimental data collected at an experimental house located near Oak Ridge, Tennessee. The model shows good agreement with the experimental data—heat pump entering fluid temperatures typically within 1°C (1.8°F)—with minor discrepancies due to approximations, such as constant moisture content throughout the year, uniform evapotranspiration over the seasons, and lack of ground shading in the model.

Floriculture Sustainability Research Coalition: Bringing the Latest Sustainability Research to the Industry

C onsumer interest in environmentally friendly products has increased greenhouse growers’ interest in sustainable production techniques. It is estimated that consumers would spend up to 15% more for sustainable floricultural products than conventionally produced products, and purchasers of herbaceous or floricultural plant products tend to be more eco-friendly than those who purchase woody plant materials (Behe et al., 2010; Hawkins et al., 2011). In 2008, the Floriculture Sustainability Research Coalition (FSRC) was formed to provide information regarding sustainable production techniques for growers. Forming a coalition has allowed the group to broaden our expertise to have a more meaningful impact on growers’ production practices. The FSRC began in 2008 at the National Floriculture Forum. Founding institutions include Purdue University, University of New Hampshire, Cornell University, and University of Maine. Our core purpose is to develop central sustainability themes for outreach and research programs that synergistically build on individual strengths to increase knowledge and create outreach materials that benefit our audience. Alone, it is difficult to have much of an impact on such a large topic. But, as a group, we could potentially have more impact—not only topically, but also regionally. Cornell University examines sustainable and organic fertilizer use and energy conservation, Purdue University provides expertise in sustainable lighting and energy conservation, University of New Hampshire specializes in nonchemical growth regulation and sustainable fertilizer use, and at University of Maine, research focuses on water conservation and organic substrates and fertilizers. Over the past 3 years, the FSRC has provided research-based information to help growers produce floricultural crops more sustainably. Recent initiatives have included exploring techniques for sustainably heating greenhouses, reducing plant stretch without the use of chemical growth retardants, and developing protocols for using organic fertilizers. Conserving energy is a priority for greenhouse growers throughout the United States. A survey of greenhouse growers indicates that 55% of growers are currently using energy conservation practices; an additional 8% would like to conserve energy (Dennis et al., 2010). Our group has published several articles on novel techniques to reduce energy. For example, Lopez and Krug (2009) reported that growing medium-vigor poinsettia (Euphorbia pulcherrima) cultivars at a temperature 10 F less than recommended (75/ 67 F day/night) does not reduce crop quality for some cultivars, including ‘Freedom Red’. But, this reduction in temperature set points in the fall would reduce fuel usage for greenhouse growers. At Cornell, bedding plants including ‘Safari Orange’ marigold (Tagetes patula), ‘Delta Formula Mix’ pansy (Viola ·wittrockiana), ‘Dreams Midnight’ petunia (Petunia ·hybrida), ‘Montego Mix’ snapdragon (Antirrhinum majus), and ‘Dreamland Mix’ zinnia (Zinnia elegans) were grown in an unheated high tunnel. Compared with the heated greenhouse environment, temperatures in the high tunnel were 5 F cooler (Table 1). Pansy plants did not finish significantly later in the high tunnel compared with the greenhouse; the other plants finished about 1 week later in the high tunnel. Part of our efforts in this area has focused on extension and outreach to support growers who are transitioning to more sustainable heating technologies. In trade publications, we have highlighted innovative growers who may inspire others by example (Burnett et al., 2010). Currently, Purdue University, in collaboration with Michigan State University, University of Arizona, and Rutgers University, isworkingonaU.S.Department of Agriculture (USDA) Specialty Crops Research Initiative grant to develop light-emitting diodes as supplemental and photoperiodic lighting for greenhouses. Another highlight of our work with sustainable production has focused on finding alternatives to chemical growth retardants. Our approach to reducing plant stretch without chemical growth retardants has been to recommend that growers adjust the greenhouse or plant environment. R. Lopez and B. Krug have represented our group to growers nationally and regionally. Some techniques we have successfully used include reducing water to reduce turgor in a controlled manner. Using new moisture sensors, plants may be grown in substrates that are maintained at constant moisture contents. So, they may be grown in relatively dry substrates (volumetric water content = 15% to 25% in a peatlite mix) without risking plant damage. This may reduce plant height, but controlled drought also reduces branching (Burnett and van Iersel, 2008). One straightforward way to reduce elongation is simply to grow plants at the appropriate light level. This will reduce plant stretch by minimizing shading, particularly from neighboring plants.

Geotechnical properties of municipal solid waste at different phases of biodegradation

This paper presents the results of laboratory investigation conducted to determine the variation of geotechnical properties of synthetic municipal solid waste (MSW) at different phases of degradation. Synthetic MSW samples were prepared based on the composition of MSW generated in the United States and were degraded in bioreactors with leachate recirculation. Degradation of the synthetic MSW was quantified based on the gas composition and organic content, and the samples exhumed from the bioreactor cells at different phases of degradation were tested for the geotechnical properties. Hydraulic conductivity, compressibility and shear strength of initial and degraded synthetic MSW were all determined at constant initial moisture content of 50% on wet weight basis. Hydraulic conductivity of synthetic MSW was reduced by two orders of magnitude due to degradation. Compression ratio was reduced from 0.34 for initial fresh waste to 0.15 for the mostly degraded waste. Direct shear tests showed that the fresh and degraded synthetic MSW exhibited continuous strength gain with increase in horizontal deformation, with the cohesion increased from 1 kPa for fresh MSW to 16–40 kPa for degraded MSW and the friction angle decreased from 35° for fresh MSW to 28° for degraded MSW. During the triaxial tests under CU condition, the total strength parameters, cohesion and friction angle, were found to vary from 21 to 57 kPa and 1° to 9°, respectively, while the effective strength parameters, cohesion and friction angle varied from 18 to 56 kPa and from 1° to 11°, respectively. Similar to direct shear test results, as the waste degrades an increase in cohesion and slight decrease in friction angle was observed. Decreased friction angle and increased cohesion with increased degradation is believed to be due to the highly cohesive nature of the synthetic MSW. Variation of synthetic MSW properties from this study also suggests that significant changes in geotechnical properties of MSW can occur due to enhanced degradation induced by leachate recirculation.

Physical Properties, Molecular Structures, and Protein Quality of Texturized Whey Protein Isolate: Effect of Extrusion Temperature

Although extrusion technology has contributed much to increasing the effective utilization of whey, the effect of extrusion conditions on the functional properties of the proteins is not well understood. In this work, the impact of extrusion temperature on the physical and chemical properties, molecular structures, and protein quality of texturized whey protein isolate (WPI) was investigated at a constant moisture content and compared with WPI treated with simple heat only. The Bradford assay methods, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and reversed-phase high-performance liquid chromatography techniques were used to determine protein solubility and to analyze compositional changes in the two major whey proteins, α-lactalbumin and β-lactoglobulin. Circular dichroism and intrinsic tryptophan fluorescence spectroscopic techniques were applied to study the secondary and tertiary structures of the proteins. This study demonstrated that extrusion temperature is a critical but not the sole determining factor in affecting the functional properties of extruded WPI.

Emission rates of N2O and CO2 from soils with different organic matter content from three long-term fertilization experiments—a laboratory study

Increasing organic matter stocks in soils reduce atmospheric carbon dioxide (CO2), but they may also promote emissions of nitrous oxide (N2O) by providing substrates for nitrification and denitrification and by increasing microbial O2 consumption. The objectives of this study were to determine the effects of fertilization history, which had resulted in different soil organic matter stocks on (1) the emission rates of N2O and CO2 at a constant soil moisture content of 60% water-holding capacity, (2) the short-term fluxes of N2O and CO2 following the application of different fertilizers (KNO3 vs. farmyard manure from cattle) and (3) the response to a simulated heavy rainfall event, which increased soil moisture to field capacity. Soil samples from different treatments of three long-term fertilization experiments in Germany (Methau, Sproda and Bad Lauchstadt) were incubated in a laboratory experiment with continuous determination of N2O and CO2 emissions and a monitoring of soil mineral N. The long-term fertilization treatments included application of mineral N (Methau and Sproda), farmyard manure + mineral N (Methau and Sproda), farmyard manure deposition in excess (Bad Lauchstadt) and nil fertilization (Bad Lauchstadt). Long-term addition of farmyard manure increased the soil organic C (SOC) content by 55% at Methau (silt loam), by 17% at Sproda (sandy loam) and by 88% at Bad Lauchstadt (silt loam; extreme treatment which does not represent common agricultural management). Increased soil organic matter stocks induced by long-term application of farmyard manure at Methau and Sproda resulted in slightly increased N2O emissions at a soil moisture content of 60% water-holding capacity. However, the effect of fertilization history and SOC content on N2O emissions was small compared to the short-term effects induced by the current fertilizer application. At Bad Lauchstadt, high N2O emissions from the treatment without fertilization for 25 years indicate the importance of a sustainable soil organic matter management to maintain soil structure and soil aeration. Emissions of N2O following the application of nitrate and farmyard manure differed because of their specific effects on soil nitrate availability and microbial oxygen consumption. At a soil moisture content of 60% water-holding capacity, fertilizer-induced emissions were higher for farmyard manure than for nitrate. At field capacity, nitrate application induced the highest emissions. Our results indicate that feedback mechanisms of soil C sequestration on N2O emissions have to be considered when discussing options to increase soil C stocks.

Optimization of HTST process parameters for production of ready-to-eat potato-soy snack

Ready-to-eat (RTE) potato-soy snacks were developed using high temperature short time (HTST) air puffing process and the process was found to be very useful for production of highly porous and light texture snack. The process parameters considered viz. puffing temperature (185-255°C) and puffing time (20-60s) with constant initial moisture content of 36.74% and air velocity of 3.99m.s(-1) for potato-soy blend with varying soy flour content from 5% to 25% were investigated using response surface methodology following central composite rotatable design (CCRD). The optimum product in terms of minimum moisture content (11.03% db), maximum expansion ratio (3.71), minimum hardness (2,749.4g), minimum ascorbic acid loss (9.24% db) and maximum overall acceptability (7.35) were obtained with 10.0% soy flour blend in potato flour at the process conditions of puffing temperature (231.0°C) and puffing time (25.0s).

The Effect of Using a Heating Tube in an Existing Spouted Bed Superheated Steam Dryer

Interest in the use of biofuels, such as pellets and briquettes, has continued to grow in the European market in recent years. In order to manage the increased use of biofuels, the dryer capacity must also increase. One possible way of accomplishing this is to install heating tubes into the already existing dryers. Therefore, industrially relevant and appropriate design data, such as energy efficiency and a possible increase in the capacity of developing drying systems, are needed. This article presents the experimental results obtained from drying sawdust in a continuous spouted bed using a heating tube submerged in the bed; the results are compared with those obtained from a bed without using a heating tube. Superheated steam is used as the drying gas in all tests. The drying test is performed with an almost constant inlet moisture content and at three different inlet and outlet temperatures. The drying efficiency increases when the heating tube is turned on. Some explanations of the relation between inlet and outlet gas temperature and moisture content are presented.

Rheological and nutritional quality of selected dehulled legumes blended rice extrudates.

Rheological and nutritional quality of ready-to-eat rice (Oryza sativa ) -legume viz. black gram (Vigna mungo), green gram (Vigna radiata), lentil (Lens culinaris) and peas (Pisum sativum) based extrudates were studied using low cost collet extruder. Extrudates were prepared keeping constant feed rate (25kg/h) and moisture content (14% wb) at 0, 5, 10 and 15% legume incorporation levels. Rheological properties of porridge made of extrudate flour were evaluated using Rapid Visco Analyser (RVA). Maximum and minimum peak viscosity for rice extrudates alone and rice extrudates blended with 15% peas were 697 cp and 523 cp, respectively. There was a decreasing trend in degree of gelatinization with increase in legume incorporation level. Other RVA rheological parameters like trough break down and final viscosity were in the range of 266-226 cp, 431-297 cp and 452-375 cp respectively. Maximum values of protein, fat, fibre and ash contents were found in rice extrudates at 15% legumes blend levels. There was an increasing trend in nutrient contents with legume content in rice extrudates. Degree of gelatinization for rice alone extrudate was 29.4% and showed a decrease in gelatinization with increase in legumes extrudate and was minimum (22.4%) for rice blended with 15% dehulled green gram. Sensory evaluation scores for all extrudates showed the most acceptable range of 6 to 8. Thus, legume blend level (up to 15%) of dehulled legumes fetched good scores and showed promising trend for the production of low cost expanded extrudates and its instant flour.

Determining the Critical Relative Humidity at which the Glassy to Rubbery Transition Occurs in Polydextrose Using an Automatic Water Vapor Sorption Instrument

Similar to an increase in temperature at constant moisture content, water vapor sorption by an amorphous glassy material at constant temperature causes the material to transition into the rubbery state. However, comparatively little research has investigated the measurement of the critical relative humidity (RHc) at which the glass transition occurs at constant temperature. Thus, the central objective of this study was to investigate the relationship between the glass transition temperature (Tg), determined using thermal methods, and the RHc obtained using an automatic water vapor sorption instrument. Dynamic dewpoint isotherms were obtained for amorphous polydextrose from 15 to 40 °C. RHc was determined using an optimized 2nd-derivative method; however, 2 simpler RHc determination methods were also tested as a secondary objective. No statistical difference was found between the 3 RHc methods. Differential scanning calorimetry (DSC) Tg values were determined using polydextrose equilibrated from 11.3% to 57.6% RH. Both standard DSC and modulated DSC (MDSC) methods were employed, since some of the polydextrose thermograms exhibited a physical aging peak. Thus, a tertiary objective was to compare Tg values obtained using 3 different methods (DSC first scan, DSC rescan, and MDSC), to determine which method(s) yielded the most accurate Tg values. In general, onset and midpoint DSC first scan and MDSC Tg values were similar, whereas onset and midpoint DSC rescan values were different. State diagrams of RHc and experimental temperature and Tg and %RH were compared. These state diagrams, though obtained via very different methods, showed relatively good agreement, confirming our hypothesis that water vapor sorption isotherms can be used to directly detect the glassy to rubbery transition. Practical Application: The food polymer science (FPS) approach, pioneered by Slade and Levine, is being successfully applied in the food industry for understanding, improving, and developing food processes and products. However, despite its extreme usefulness, the Tg, a key element of the FPS approach, remains a challenging parameter to routinely measure in amorphous food materials, especially complex materials. This research demonstrates that RHc values, obtained at constant temperature using an automatic water vapor sorption instrument, can be used to detect the glassy to rubbery transition and are similar to the Tg values obtained at constant %RH, especially considering the very different approaches of these 2 methods--a transition from surface adsorption to bulk absorption (water vapor sorption) versus a step change in the heat capacity (DSC thermal method).

Soil microbial biomass and activity response to repeated drying–rewetting cycles along a soil fertility gradient modified by long-term fertilization management practices

The effects of repeated drying–rewetting (DRW) cycles on the microbial biomass and activity in soils taken from long-term field experiment plots with different fertilization (FERT) management practice histories were studied. We investigated the hypothesis that soil response to DRW cycles differs with soil fertility gradient modified by FERT management practices. The soils were incubated for 51 days, after exposure to either nine or three DRW cycles, or remaining at constant moisture content (CMC) at field capacity. We found that both DRW and FERT significantly affected soil properties including NH 4–N, NO 3–N, dissolved organic C (DOC), microbial biomass C (Cmic), basal soil respiration rate (BSR), urease activity (URE) and dehydrogenase activity (DHD). Except for NH 4–N and BSR, variation in the properties was largely explained by FERT, followed by DRW, and then their interaction. Irrespective of the soils' FERT treatment, repeated DRW cycles significantly raised the DOC and Cmic levels compared with CMC, and the DRW cycles also resulted in a significant decline in BSR and URE and increase in DHD, probably because the organisms were better-adapted to the drying and rewetting stresses. The variations in soil biological properties caused by DRW cycles showed a significantly negative relationship with the soil organic C content measured prior to the start of the DRW experiments, suggesting that soils with higher fertility are better able to maintain their original biological functions (i.e., have a higher functional stability) in response to DRW cycles.

Stationary gas flow to a vertical extraction well in MSW landfill considering the effect of mechanical settlement on hydraulic properties

Biogas recovery is a main concern in landfill management since it controls greenhouse gas emission from these facilities. Moreover, it is a key issue for the efficiency of energy from waste technologies associated with the emerging landfill bioreactor. In such enhanced biodegradation condition, the biogas production should be significantly higher than in classical landfill facilities. The design of biogas collection system thus requires a good understanding of biogas migration from the waste body to the extraction well. This paper presents a theoretical study of biogas flow in an axi-symmetric domain around a vertical extraction well taking into account various cap cover designs. A set of laboratory experimental data is used to describe the effect of mechanical settlement on the waste hydraulic properties. In order to focus on the effect of mechanical settlement, the coupling of biogas and leachate flow is neglected considering a constant gravimetric moisture content. The comparison of the resulting heterogeneous medium with an equivalent homogeneous medium exhibits a very sensitive effect of settlement on gas pressure and velocity distributions. A general trend to improve the well collection efficiency is observed but should be tempered because in situ and laboratory hydraulic properties may differ and because the effect of air entry on the anaerobic bioreaction should be considered. The effect of operating parameters (well suction, waste thickness, biogas generation rate) is evaluated with a parametric study that could be summarised using simple shape factors.

Solid-State Stability of Spray-Dried Insulin Powder for Inhalation: Chemical Kinetics and Structural Relaxation Modeling of Exubera Above and Below the Glass Transition Temperature

The effect of temperature on the chemical stability of an amorphous spray-dried insulin powder formulation (Exubera) was evaluated in the solid state at constant moisture content. The chemical stability of the powder was assessed using reversed-phase high-performance liquid chromatography (RP-HPLC) and high-performance-size exclusion chromatography (HP-SEC). The major degradants in spray-dried insulin produced during heat stressing were identified as A21-desamidoinsulin (A21) and high molecular weight protein (HMWP). As expected, the rates of formation of A21 and HMWP were observed to increase with temperature. A stretched-time kinetic model (degradation rate is proportional to the square root of time) was applied to the degradant profiles above and below the glass transition temperature (T(g)) and apparent reaction rate constants were determined. Below T(g), isothermal enthalpy of relaxation measurements were used to assess the effect of temperature on molecular mobility. The formation of A21 and HMWP was found to follow an Arrhenius temperature dependence above and below the T(g). Comparison of reaction rate constants to those estimated from structural relaxation experiments suggests that the reaction pathways to form A21 and HMWP below the T(g) may be coupled with the molecular motions involved in structural relaxation.

Transient Moisture Distribution and Hygrothermal Stress Analysis of Composite Laminates Using Equivalent Diffusion Methods

It often takes several decades to reach moisture equilibrium state in composite laminates. Therefore, hourly varying fluctuating boundary moisture and temperature conditions require several millions of time steps to reach a state of equilibrium. A new transient analysis method is proposed to efficiently solve moisture distribution of composite laminates with rapidly fluctuating moisture and temperature boundary conditions. First, effective constant diffusivity and maximum moisture content were obtained by averaging transient temperature-dependent moisture diffusivity. In this way, a simple analytic solution can be effectively used to determine the transient moisture distribution under hourly fluctuating boundary conditions. Its efficiencies are demonstrated in three different conditions by comparing this method with a conventional finite difference method. Hygrothermal stress and material degradation were consequently discussed to demonstrate that we must avoid a simple knock-down factor or 40% devastating penalty and use more rational simulation and supporting data.

Effect of Annealing Conditions on Thermal Properties and Crystallization Behavior of Poly(ethylene terephthalate)

Abstract Thermal properties and crystallization behav-ior of PET were investigated by controlling the annealing conditions, such as relative humidity, annealing temperature, and annealing time. The variations of moisture content, glass transition temperature (Tg) and cold crystallization temperature (Tcc) were analyzed after annealing the PET specimens. Crystallization processing was performed with annealed PET specimens, and then the degree of crystallinity and the heat distortion temperature (HDT) were examined. Moisture content in the PET specimens increased with increasing the relative humidity, annealing temperature, and annealing time. Tg and Tcc of the annealed PET specimens decreased with increasing moisture content. The degree of crystallinity increased as increasing moisture content in the PET specimens. Although the moisture contents in the specimens after annealing were the same, the degree of crystallinity varied. The degree of crystallinity was affected by residual stress for constant moisture content. The relaxation of residual stress in the PET specimens differed depending on the annealing conditions, and the maximum degree of crystallinity increased with decreasing residual stress in the PET specimens.

Comparison of deterioration of rye under two different storage regimes

Deterioration of stored rye samples was studied at different moisture contents and temperatures. Germination, presence of visible and invisible microflora, and free fatty acid values (FAV) were determined for samples at 10.0, 12.5, 15.0 and 17.5% moisture content (wet mass basis) stored at 10, 20, 30 and 40 °C for 16 weeks. Results of deterioration at constant moisture content (case 1) were compared with previously reported results for deterioration under declining moisture content (case 2). Germination rate was almost the same for all the moisture content samples stored at 10 °C for both cases, but a significant decrease was observed at other temperatures with high moisture content. Fatty acid values remained similar in both cases when rye was stored at 10 and 20 °C, whereas at 30 and 40 °C, FAVs of the rye samples in which the moisture content was maintained were high and increased with an increase in temperature and moisture content. Visible mould appeared early in the samples whose moisture content was maintained. Penicillium spp. and Aspergillus glaucus group were the predominant fungal species present in both the cases throughout the study. The rate of deterioration was significantly different between the two cases.

Microbial degradation of sulfentrazone in a Brazilian rhodic hapludox soil.

Sulfentrazone is amongst the most widely used herbicides for treating the main crops in the State of São Paulo, Brazil, but few studies are available on the biotransformation of this compound in Brazilian soils. Soil samples of Rhodic Hapludox soil were supplemented with sulfentrazone (0.7 µg active ingredient (a.i.) g-1 soil) and maintained at 27°C. The soil moisture content was corrected to 30, 70 or 100 % water holding capacity (WHC) and maintained constant until the end of the experimental period. Herbicide-free soil samples were used as controls. Another experiment was carried out using soil samples maintained at a constant moisture content of 70% WHC, supplemented or otherwise with the herbicide, and submitted to different temperatures of 15, 30 and 40° C. In both experiments, aliquots were removed after various incubation periods for the quantitative analysis of sulfentrazone residues by gas chromatography. Herbicide-degrading microorganisms were isolated and identified. After 120 days a significant effect on herbicide degradation was observed for the factor of temperature, degradation being higher at 30 and 40° C. A half-life of 91.6 days was estimated at 27° C and 70 % WHC. The soil moisture content did not significantly affect sulfentrazone degradation and the microorganisms identified as potential sulfentrazone degraders were Nocardia brasiliensis and Penicillium sp. The present study enhanced the prospects for future studies on the bio-prospecting for microbial populations related to the degradation of sulfentrazone, and may also contribute to the development of strategies for the bioremediation of sulfentrazone-polluted soils.

Cantilever experimental setup for rheological parameter identification in relation to wood drying

Wood exhibits a pronounced time dependent deformation behavior which is usually split into ‘viscoelastic’ creep at constant moisture content (MC) and ‘mechano-sorptive’ creep in varying MC conditions. Experimental determination of model rheological parameters on a material level remains a serious challenge, and diversity of experimental methods makes published results difficult to compare. In this study, a cantilever experimental setup is proposed for creep tests because of its close analogy with the mechanical behavior of wood during drying. Creep measurements were conducted at different load levels (LL) under controlled temperature and humidity conditions. Radial specimens of white spruce wood [Picea glauca (Moench.) Voss.] with dimensions of 110 mm in length (R), 25 mm in width (T), and 7 mm in thickness (L) were used. The influence of LL and MC on creep behavior of wood was exhibited. In constant MC conditions, no significant difference was observed between creep of tensile and compressive faces of wood cantilever. For load not greater than 50% of the ultimate load, the material exhibited a linear viscoelastic creep behavior at the three equilibrium moisture contents considered in the study. The mechano-sorptive creep after the first sorption phase was several times greater than creep at constant moisture conditions. Experimental data were fitted with numerical simulation of the global rheological model developed by authors for rheological parameter identification.

MOISTURE ADSORPTION THERMODYNAMICS OF FRACTIONATED SESAME HULLS (SESAMUM INDICUM L.)

ABSTRACT Sesame hulls are a useful byproduct of sesame processing industry. Moisture adsorption isotherms (MSIs) for whole sesame hulls (WSHs) and powdered sesame hulls (PSHs) were obtained at 15, 30 and 45C, and 0.05 to 1.5 moisture content (decimal dry basis) using a water activity meter. Four MSI models were tested. Halsey model was found to provide the best fit for experimental data for both WSHs and PSHs. Standard error of estimate, %P and pseudo‐R2 values were: 0.00168 and 0.00248, 4.7 and 5.7%, and 0.963 and 0.974, respectively. Equilibrium relative humidity (ERH) values of PSHs were greater than those of WSHs at constant moisture content. Differential enthalpy (qst) and entropy (ΔSd) decreased exponentially with the increase in equilibrium moisture content, then became constant beyond 0.7 moisture content. qst and ΔSd values were larger for WSHs than PSHs. Enthalpy–entropy compensation was found to exist for both PSHs and WSHs. An entropy‐driven process was observed, with the free energy change (ΔG) for WSHs and PSHs of+0.0183 kJ/kg and−0.0284 kJ/kg, respectively. The spreading pressure was found to increase with the increase in ERH and decrease in temperature. The net integral enthalpy (ΔHi) decreased then reached an asymptote beyond a moisture content of 0.15 for both PSHs and WSHs. Net integral enthalpy was larger for WSHs. The net integral entropy (ΔSi) was negative for PSHs and WSHs, and ΔSi was greater in magnitude for PSHs.PRACTICAL APPLICATIONSSesame hulls are useful byproducts of sesame processing industry. Large amounts of this effluent are produced yearly in Jordan. They are used as livestock feed, but they require further dehydration to reduce moisture content and water activity into safe levels. In this project, drying thermodynamics of sesame hulls were discussed.

Inverse Method to Estimate Kinetic Degradation Parameters of Grape Anthocyanins in Wheat Flour Under Simultaneously Changing Temperature and Moisture

Thermal and moisture effects on grape anthocyanin degradation were investigated using solid media to simulate processing at temperatures above 100 degrees C. Grape pomace (anthocyanin source) mixed with wheat pastry flour (1: 3, w/w dry basis) was used in both isothermal and nonisothermal experiments by heating the same mixture at 43% (db) initial moisture in steel cells in an oil bath at 80, 105, and 145 degrees C. To determine the effect of moisture on anthocyanin degradation, the grape pomace-wheat flour mixture was heated isothermally at 80 degrees C at constant moisture contents of 10%, 20%, and 43% (db). Anthocyanin degradation followed a pseudo first-order reaction with moisture. Anthocyanins degraded more rapidly with increasing temperature and moisture. The effects of temperature and moisture on the rate constant were modeled according to the Arrhenius and an exponential relationship, respectively. The nonisothermal reaction rate constant and activation energy (mean +/- standard error) were k(80 degrees C, 43% (db) moisture) = 2.81 x 10(-4)+/- 1.1 x 10(-6) s(-1) and DeltaE = 75273 +/- 197 J/g mol, respectively. The moisture parameter for the exponential model was 4.28 (dry basis moisture content)(-1). One possible application of this study is as a tool to predict the loss of anthocyanins in nutraceutical products containing grape pomace. For example, if the process temperature history and moisture history in an extruded snack fortified with grape pomace is known, the percentage anthocyanin loss can be predicted.