Order Polynomial Relationship Research Articles

Effective moisture diffusivity of pomegranate arils under going microwave-vacuum drying

Drying of pomegranate arils was done using microwave-vacuum technique, using microwave power of 25 to 95W, vacuum pressure of 25 to 195mmHg and sample mass of 65 to 235g. The effective moisture diffusivity varied from 5.18×10−11 to 6.58×10−10m2/s. Effective moisture diffusivity (Deff) values were found to increase as microwave power increases or sample mass decreases for constant values of remaining variables while vacuum pressure had negligible effect. A third order polynomial relationship was found to correlate the effective moisture diffusivity (Deff) with moisture content. Multivariate polynomial models were also developed for estimating the effective moisture diffusivity as a function of the microwave-vacuum drying process parameters.

Exploring the origin, the nature, and the dynamical behavior of distant stars in galaxy models

We explore the regular or chaotic nature of orbits moving in the meridional plane of an axially symmetric galactic gravitational model with a disk, a dense spherical nucleus and some additional perturbing terms corresponding to influence from nearby galaxies. In order to obtain this we use the Smaller ALingment Index (SALI) technique integrating extensive samples of orbits. Of particular interest is the study of distant, remote stars moving in large galactocentric orbits. Our extensive numerical experiments indicate that the majority of the distant stars perform chaotic orbits. However, there are also distant stars displaying regular motion as well. Most distant stars are ejected into the galactic halo on approaching the dense and massive nucleus. We study the influence of some important parameters of the dynamical system, such as the mass of the nucleus and the angular momentum, by computing in each case the percentage of regular and chaotic orbits. A second order polynomial relationship connects the mass of the nucleus and the critical angular momentum of the distant star. Some heuristic semi-theoretical arguments to explain and justify the numerically derived outcomes are also given. Our numerical calculations suggest that the majority of distant stars spend their orbital time in the halo where it is easy to be observed. We present evidence that the main cause for driving stars to distant orbits is the presence of the dense nucleus combined with the perturbation caused by nearby galaxies. The origin of young O and B stars observed in the halo is also discussed.

Evaluation of several calibration procedures for a portable soil moisture sensor

Summary The calibration and validation of remotely sensed soil moisture products relies upon an accurate source of ground truth data. The primary method of providing this ground truth is to conduct intensive field campaigns with manual surface soil moisture sampling measurements, which utilize gravimetric sampling, soil moisture probes, or both, to estimate the volumetric soil water content. Soil moisture probes eliminate the need for labor-intensive gravimetric sampling. To ensure the accuracy of these probes, several studies have determined these probes need various degrees of localized calibration. This study examines six possible calibration techniques using data collected during a field campaign conducted in 2012, with soil moisture samples being collected over 55 fields in southern Manitoba, as part of the Soil Moisture Active Passive Validation Experiment 2012 (SMAPVEX12). The use of a general equation, applied to all collected data, resulted in the largest error regardless of whether a linear or third order polynomial relationship was established for the calibration of the soil moisture probes. Calibration equations based on soil texture or vegetation land cover reduced the error; however, the individual calibration equations established for each field in the study had the lowest error of all the calibration techniques. Although average bias was low for all of the calibration techniques, the use of the general equation to calibrate individual fields resulted in high biases for some fields.

Supplementation of microbial levan in the diet of Cyprinus carpio fry (Linnaeus, 1758) exposed to sublethal toxicity of fipronil: effect on growth and metabolic responses

A 60-day feeding trial was conducted to study the effect of dietary microbial levan on growth performance and metabolic responses of Cyprinus carpio fry exposed to sublethal dose (1/10th LC₅₀) of fipronil [(±)-5-amino-1-(2,6-dichloro-α,α,α-trifluoro-p-tolyl)-4-trifluoromethylsulfinylpyrazole-3-carbonitrile]. Two hundred and twenty five fry were randomly distributed in five treatments in triplicates. Four purified diets were prepared with graded levels of microbial levan. Five different treatment groups were levan control L₀P₀ (basal feed + 0 % levan without exposure to pesticide); pesticide control L₀P₁ (basal feed + 0 % levan with exposure to pesticide); L₀.₂₅P₁ (basal feed + 0.25 % levan with exposure to pesticide); L₀.₅₀P₁ (basal feed + 0.50 % levan with exposure to pesticide); and L₀.₇₅P₁ (basal feed + 0.75 % levan with exposure to pesticide). Weight gain% and specific growth rate were significantly higher (p < 0.05) in levan fed groups compared to their non-levan fed counterpart. Highest (p < 0.05) content of ascorbic acid in muscle, liver and brain tissues was observed with higher level of dietary levan. Glucose-6-phosphate dehydrogenase activity decreased with the increasing level of dietary levan in the liver and muscle. Aspartate aminotransferase activity exhibited a second order polynomial relationship with the dietary levan, both in liver (Y = -1.001x² + 5.366x + 5.812, r² = 0.887) and muscle (Y = -0.566x² + 2.833x + 6.506, r² = 0.858) while alanine aminotransferase activity showed third order polynomial relationship both in liver (Y = 1.195x³ - 12.30x² + 35.23x + 9.874, r² = 0.879) and muscle (Y = 0.527x³ - 8.429x² + 31.80x + 8.718, r² = 0.990). Highest (p < 0.05) superoxide dismutase activity in gill was observed in the group fed with 0.75 % levan supplemented diet. Overall results indicated that dietary microbial levan at 0.75 % in C. carpio fry ameliorated the negative effects of fipronil and augmented the growth.

Study of the drying kinetics of pepper

The present study investigated the influence of microwave power on the drying kinetics, energy consumption and drying efficiency of green pepper during microwave drying at 180, 240, 300, 360, 420, 480 and 540W. Seven mathematical models for describing the thin-layer drying behaviour of pepper samples were investigated. The models were compared based on their R2, RMSE and χ2 values between experimental and predicted moisture ratios. By increasing the microwave output powers (180–540W), the drying time decreased from 9 to 2.5min. The drying process took place in the falling rate period. The results show that the Midilli model is the most appropriate model for drying behaviour of thin layer pepper samples. A third order polynomial relationship was found to correlate the effective moisture diffusivity with moisture content. The effective moisture diffusivity increased with decrease in moisture content of pepper samples. The average effective diffusivity varied from 8.315×10−8 to 2.363×10−7m2/s, over the microwave power range studied, with an energy activation of 14.19W/g. Energy efficiency increased with increase in microwave power and moisture content. The least specific energy consumption (4.99MJ/kg water) was at the microwave power of 240W and the highest (6.80MJ/kg water) was at 180W.

Mathematical Modeling, Moisture Diffusion, Energy consumption and Efficiency of Thin Layer Drying of Potato Slices

In this research, drying characteristics, energy requirement and drying efficiency for microwave drying of potato slices were reported. The drying experiments were carried out at 200, 250, 300, 350, 400, 450 and 500 W with slice thickness of 5 mm. In this study, measured values were compared with predicted values obtained from Page’s thin layer drying semi-empirical model according to R2, χ2 and RMSE. The increase in microwave power significantly reduced the drying time from 9.5 to 3.25 min of the potato slices. Experimental drying curves showed only a falling drying rate period. A third order polynomial relationship was found to correlate the effective moisture diffusivity (Deff) with moisture content. The values of drying rate constant (k) and Deff increased from 0.105 to 0.322 (1/min) and 1.013×10-8 to 3.799 ×10-8 m2/s with the increase of microwave power level, respectively. Also, the effective moisture diffusivity increased with decrease in moisture content of samples. The activation energy for the moisture diffusion was determined to be 14.945 W/g. Drying efficiency increased with increase in microwave power and moisture content. The minimum and the maximum specific energy consumption and drying efficiency for drying of potato slices were determined as 4.645 (MJ/kg water) and 48.59% for 500 W and 5.882 (MJ/kg water) and 38.37% for 300 W, respectively.

Dietary microbial levan ameliorates stress and augments immunity inCyprinus carpiofry (Linnaeus, 1758) exposed to sublethal toxicity of fipronil

A 45-day feeding trial was conducted to study the stress ameliorating and immunomodulatory role of microbial levan in Cyprinus carpio fry exposed to sublethal dose (1/10th LC50) of fipronil [(±)-5-amino-1-(2,6-dichloro-α,α,α-trifluoro-p-tolyl)-4-trifluoromethylsulfinylpyrazole-3-carbonitrile]. Two hundred and twenty-five fry were randomly distributed in five treatments in triplicates. Four purified diets were prepared with graded levels of microbial levan. Five different treatment groups were levan control L0P0 (basalfeed + 0% levan without exposure to pesticide); pesticide control L0P1 (basalfeed + 0% levan with exposure to pesticide); L0.25P1 (basalfeed + 0.25% levan with exposure to pesticide); L0.50P1 (basalfeed + 0.50% levan with exposure to pesticide) and L0.75P1 (basalfeed + 0.75% levan with exposure to pesticide). Lactate dehydrogenase (LDH), malate dehydrogenase (MDH) and fructose-1,6-diphosphatase (FDPase) activites were significantly (P < 0.05) increased, whereas alkaline phosphatase (ALP), adenosine triphosphatase (ATPase) and acetyl choline esterase (AchE) activities were significantly (P < 0.05) reduced in higher levan-fed groups. RBC, haemoglobin and WBC counts were significantly (P < 0.05) increased in the levan-fed groups. Similar trends were also observed for the total serum protein, globulin, NBT and lysozyme activities. Blood glucose and serum cortisol exhibited a third order polynomial relationship with increasing level of dietary levan. Overall result showed stress ameliorating, immunostimulating and protective role of microbial levan against fipronil-induced stress in C. carpio fry at 0.75% level of dietary levan supplementation.

Water table fluctuation analyses and associated empirical approach to predict spatial distribution of water table at Yeşilköy/AgiosAndronikos aquifer

The groundwater of the deep Yesilkoy aquifer is the only water resource for agricultural and domestic consumption at the Karpaz Peninsula of Cyprus, which stretches approximately 100 km from the northeast of capital Nicosia to the northern tip of Cyprus. During the last decade, over-pumping and following dry periods have depleted the groundwater resources and the water surface elevation of the aquifer has dropped. The aim of this study is to understand the behavior of the Yesilkoy aquifer in the last decade for the proper management of groundwater resources. This has been achieved based on well survey and field survey studies, monitoring programs followed by pumping tests, and safe yield analysis. Most of the research effort has been focused on field and well survey studies to quantify agricultural water consumption and abstraction rates from the aquifer. A long-term groundwater level monitoring program, short-term continuous groundwater monitoring and pumping tests provided information for the regression analyses while deriving a sixth order polynomial relationship between the period parameter and the head parameter. The equation was helpful to predict the short-term behavior of the water level when the present hydrogeological conditions prevail. The pumping test results satisfied the hydraulic properties of calcarenite formation yielding T = 1,782 m2/day and S = 0.0012. The results of safe yield analysis show that the annual deficit of the aquifer is 0.496 million cubic meters (MCM), which is equivalent to a 0.6 m drop in groundwater levels per year. Finally, the resultant annual safe yield of the aquifer is estimated as 0.84 MCM.

Efficient dynamic modelling and characterization of a magnetorheological damper

The present work is about the dynamic modelling and the experimental testing of magnetorheological (MR) dampers, especially at low frequency. The main improvement of this work over former models is the identification of dynamic parameters which are independent of the working conditions and vary only as a function of the current. A simple model is built on the basis of the literature and of a systematic experimental campaign, with the aim of simplifying the effort in retrieving the parameters and in controlling the system. The excitation current is introduced in the model as a variable, not only reducing the amount of test needed to assess the parameters, but also obtaining a faster model useful in motion control. A second order polynomial relationship between the applied current and the three variable parameters is found, showing a saturation effect at high currents. A verification test shows the reliability and the performance of the proposed model.

Dimensional analysis and scaling in mechanical mixing for fabrication of metal matrix nanocomposites

For a successful enhancement of mechanical properties of metal matrix nanocomposites, a homogeneous nanoparticle dispersion and distribution in the solidified metal is required. Mechanical mixing can be used for initial break-up of agglomerates, and its study can be simplified with dimensional analysis. Using this technique, mixing time and vortex height were assessed while varying fluid properties, impeller angle, and angular speed. Three relevant dimensionless numbers were recognized: the Reynolds (Re), Froude and Galilei (Ga) numbers. Based on blade and impeller shaft angles, a modified Froude number (Fr*) was defined. These parameters were calculated experimentally, varying angular speed from 200 to 1000rpm for three different impeller angles: 0°, 15° and 30°. This procedure was performed with three fluids: water, and two aqueous glycerin solutions (25% and 50% by volume). Digital images were taken and processed to measure vortex height. Mixing time was measured for water at 0° impeller angle, angular speed ranging from 200 to 1200rpm. Results showed an optimal dimensionless mixing time with respect to Re. A linear relationship was found between dimensionless vortex height and Fr*. The first had a second order polynomial relationship with the product ReFr*, regardless of impeller angle. This relationship, together with the Ga, specific for each fluid, allows scaling the results to other fluids such as molten pure aluminum. This study allows experimenting in simpler systems that involve transparent fluids, room temperature and low cost, to then elaborate a prediction of vortex height in fluids where measurements are difficult and costly, such as molten metals.

Effects of dietary pyridoxine on growth and biochemical responses of Labeo rohita fingerlings exposed to endosulfan

A sixty-day experiment was carried out to study the effect of dietary pyridoxine (PN) on growth performance, RNA/DNA ratio and some biochemical parameters of Labeo rohita fingerlings exposed to sub-lethal dose of endosulfan (1/10th of 96h static non-renewal LC50=0.2ppb) to assess the role of pyridoxine in ameliorating the negative effects of endosulfan. Two hundred seventy fingerlings (6.5±0.26g) were randomly distributed into six treatments in triplicates (15fish/tank). Five iso-nitrogenous (35.45–35.75% crude protein) purified diets were prepared with graded levels of pyridoxine. Six treatment groups were T0 (10mg PN+without endosulfan), T1 (0mg PN+endosulfan), T2 (10mg PN+endosulfan), T3 (50mg PN+endosulfan), T4 (100mg PN+endosulfan) and T5 (200mg PN+endosulfan). Weight gain (%), specific growth rate (SGR), tissue glycogen, and protease activity were significantly (P<0.05) higher in pyridoxine fed groups compared to their non-pyridoxine fed counterpart. Protease activity was positively correlated (R2=0.931) with (%) weight gain. Glucose-6-phosphate dehydrogenase (G6PDH) activity was significantly (P<0.05) higher in non-pyridoxine fed group and decreased in pyridoxine fed counterparts. There were no significant (P>0.05) effect of dietary pyridoxine on feed conversion ratio (FCR), protein efficiency ratio (PER), survival, gastro-somatic index (GSI), hepato-somatic index (HSI) and liver and muscle DNA levels of L. rohita fingerlings. RNA levels, both in liver and muscle, increased significantly (P<0.05) in pyridoxine fed groups. A positive correlation was observed between growth and RNA levels, both in liver (R2=0.91) and muscle (R2=0.88). RNA/DNA ratio showed a third order polynomial relationship with dietary pyridoxine, both in liver (Y=−0.014x3+0.1613x2−0.5333x+0.7933, R2=0.987) and muscle (Y=−0.0407x3+0.4763x2−1.6358x+2.4667, R2=0.9345). The overall results obtained in present study indicated that dietary pyridoxine supplementation at 100 or 200mg PN/kg diet ameliorates the negative effects of endosulfan and restores optimal growth of L. rohita fingerlings.

Effects of moisture content and temperature on the specific heat of soya bean, Moringa oleifera seed and Mucuna flagellipes nut

Abstract: The specific heat of soya bean var iety TGX 1 , 440–1E, moringa oleifera seed, moringa oleifera kernel and mucuna flagellipes nut were evaluated and their variation s with moisture content and temperature were investigated, using the method of mixture. T he specific heat of soya bean, moringa oleifera seed, moringa oleifera kernel and mucuna flagellipes nut increased linearly from 1 780 to 2 646 J/ ( kg·K ) , 1 520 to 2 516.121 J/ ( kg·K ) , 1 625.24 to 2 458.214 J/ ( kg·K ) and 2 080 to 4 586 J/ ( kg·K ) i n the moisture content and temperature ranges of 6.16 % –51.52 % (d.b . ) and 305.8–363 K, 8.43 % –31.66 % (d.b . ) and 300–341.88 K, 6.75 % –31.5 % (d.b . ) and 300–344.38 K, and 3.38 % –10.7 % (d.b . ) and 300–330.75 K, respectively . While the specific heat of soya bean increased with increase in temperature up to a certain point and decreased with further increase in temperature, the specific heat of moringa oleifera seed and kernel increased linearly, and mucuna flagellipes nut exhibited a second order polynomial relationship between its specific heat and average temperature. Regression models, which could be used to reasonably predict the specific heat of these products at specified moisture content and average temperature, were established. Key words: s oya bean var. TGX 1 , 440-1E, moringa oleifera, mucuna flagellipes , specific heat, moisture content, temperature DOI: 10.3965/j.issn.1934-6344.20 11 .0 1 .0 87 -0 92 Citation: Ndubisi A Aviara, Samuel E Ehiabhi, Obafemi O Ajibola, Suradeen A Oni, Pwanzadom P. Power, Thlama Abbas , et al. Effect of m oisture c ontent and t emperature on the s pecific h eat of s oya bean, Moringa oleifera s eed and Mucuna flagellipes n ut . Int J Agric & Biol Eng, 20 11 ; 4 ( 1 ): 87 <span style=font-size: 9pt; line-height: 140%; font-family:

Effects of moisture content and temperature on the specific heat of soya bean, Moringa oleifera seed and Mucuna flagellipes nut

Abstract: The specific heat of soya bean var iety TGX 1 , 440–1E, moringa oleifera seed, moringa oleifera kernel and mucuna flagellipes nut were evaluated and their variation s with moisture content and temperature were investigated, using the method of mixture. T he specific heat of soya bean, moringa oleifera seed, moringa oleifera kernel and mucuna flagellipes nut increased linearly from 1 780 to 2 646 J/ ( kg·K ) , 1 520 to 2 516.121 J/ ( kg·K ) , 1 625.24 to 2 458.214 J/ ( kg·K ) and 2 080 to 4 586 J/ ( kg·K ) i n the moisture content and temperature ranges of 6.16 % –51.52 % (d.b . ) and 305.8–363 K, 8.43 % –31.66 % (d.b . ) and 300–341.88 K, 6.75 % –31.5 % (d.b . ) and 300–344.38 K, and 3.38 % –10.7 % (d.b . ) and 300–330.75 K, respectively . While the specific heat of soya bean increased with increase in temperature up to a certain point and decreased with further increase in temperature, the specific heat of moringa oleifera seed and kernel increased linearly, and mucuna flagellipes nut exhibited a second order polynomial relationship between its specific heat and average temperature. Regression models, which could be used to reasonably predict the specific heat of these products at specified moisture content and average temperature, were established. Key words: s oya bean var. TGX 1 , 440-1E, moringa oleifera, mucuna flagellipes , specific heat, moisture content, temperature DOI: 10.3965/j.issn.1934-6344.20 11 .0 1 .0 87 -0 92 Citation: Ndubisi A Aviara, Samuel E Ehiabhi, Obafemi O Ajibola, Suradeen A Oni, Pwanzadom P. Power, Thlama Abbas , et al. Effect of m oisture c ontent and t emperature on the s pecific h eat of s oya bean, Moringa oleifera s eed and Mucuna flagellipes n ut . Int J Agric & Biol Eng, 20 11 ; 4 ( 1 ): 87 <span style="font-size: 9pt; line-height: 140%; font-family:

Development of a species-specific fractionation equation for Arctic charr (Salvelinus alpinus (L.)): an experimental approach

A species-specific fractionation equation for Arctic charr (Salvelinus alpinus (L.)) was developed experimentally for use in ecological studies of temperature-driven phenologies for the species. Juvenile Arctic charr were reared in controlled conditions at different temperatures (2–14°C), with three replicates of each temperature. Otoliths from the fish and water samples from the chambers were analysed for oxygen isotope composition and used to estimate temperature-dependent fractionation equations relating the isotopic ratio to rearing temperature. A linear and a second order polynomial relationship were estimated and validated using comparable Arctic charr data from another study. Temperatures predicted using the polynomial equation were not significantly different from recorded experimental temperatures, whereas with the linear equation there were significant differences between the predicted and measured temperatures. The polynomial equation also showed the least bias as measured by mean predictive error. Statistical comparisons of the polynomial fractionation equation to a similarly estimated equation for brook charr (Salvelinus fontinalis (Mitchill)) indicated significant differences. Results imply the need for species-specific fractionation equations, even for closely related fish. Results further suggest the polynomial form of the fractionation equation will facilitate more accurate characterisation of water temperatures suitable for use in ecological studies of temperature-driven phenologies of Arctic charr.

Response Surface Methodology for the Optimization and Characterization of Cassava Starch‐graft‐Poly(acrylamide)

AbstractResponse surface methodology (RSM) was employed for the synthesis of cassava starch‐graft‐poly(acrylamide) using ceric ammonium nitrate as free radical initiator. Concentration of acrylamide, concentration of ceric ammonium nitrate, reaction temperature and duration of reaction were optimized using a 4‐factor 3‐level Box‐Behnken design. The dependent variables were percentage grafting (%G) and grafting efficiency (GE). Second order polynomial relationships were obtained for %G and GE, which explained the main, quadratic and interaction effects of factors. The highest%G and GE obtained were 174.8% and 90.7%, respectively. The optimum values of parameters predicted through RSM were 20 g acrylamide/10 g dry starch, 3.3 g/L ceric ammonium nitrate, 180 min reaction duration and 45ºC temperature with a %G of 190.0. For GE, the predicted levels of factors for the optimum value of 90.8% were 17.5 g acrylamide/10 g dry starch, 4.1 g/L ceric ammonium nitrate, 180 min reaction duration and 55ºC temperature. The graft reaction was confirmed by FTIR analysis, where the absorption bands corresponding to the C=O stretching and N‐H bending of the –CONH2 group were observed. Scanning electron microscopic studies on grafted starches revealed that the granular structure of the starch was affected by the reaction. X‐ray diffraction analysis showed that the crystallinity of starch was decreased as a result of grafting and the reduction was higher for the grafted starches with higher percentage grafting.

Time from ictal subdural EEG seizure onset to clinical seizure onset: an electrocorticographic time factor associated with temporal lobe epileptogenicity

Long-term subdural video/electroencephalographic (EEG) monitoring was performed in a series of patients with medically intractable complex partial seizures, in a study of diagnostic accuracy, to test the hypothesis that the time from ictal subdural EEG seizure onset to clinical seizure onset (ECOT) is correlated with temporal lobe epileptogenicity and confirm measures of validity of ECOT for predicting seizure-free outcome following anterior temporal lobectomy and amygdalohippocampectomy (ATL/AH). In 34 patients with refractory temporal lobe epilepsy, subdural EEG monitoring localized the ictal epileptogenic focus to a single temporal lobe. In each patient, ECOT was analysed for correlation with temporal lobe epileptogenicity as measured by seizure interval in hours. Patients in whom ECOT was equal to or less than the mean (i.e. subdural EEG seizure onset preceding clinical seizure onset by at least 11.7 seconds) had a significantly greater likelihood of becoming seizure-free following ATL/AH compared to patients in whom ECOT was greater than the mean (i.e. subdural EEG seizure onset preceding clinical seizure onset by less than 11.7 seconds) (x2 = 5.78, p<0.05). The validity of ECOT for predicting seizure-free outcome following ATL/AH is confirmed to have sensitivity of 55.0%, specificity of 85.7%, false positive rate of 15.4%, false negative rate of 42.9%, diagnostic value of 84.6% and diagnostic accuracy of 67.6%. In addition, a significant correlation, described by a second order polynomial relationship, was found between the natural exponential function of ECOT and seizure interval [f(x=0.415x2 −25.554x + 267.036, r= 0.731, df= 32, t =6.05, p<0.001, where f(x)=eECOT and x= seizure interval). This result provides the epileptologist with a quantitative tool capable of predicting seizure interval based on ECOT. The capability of ECOT to predict seizure interval may allow the patient and epileptologist to anticipate future seizure onset based on ECOT, potentially facilitating accurate timing of ictal seizure focus localization techniques and clinical intervention to abort seizure onset using various available central and peripheral nervous system stimulation therapeutic strategies. The results suggest a relationship between ECOT and seizure interval. Fundamental pathophysiologic processes involved in the transition from ictal EEG to clinical seizure onset may be responsible for temporal lobe epileptogenicity.

Dielectric properties of Indian Basmati rice flour slurry

Dielectric properties of Indian Basmati rice samples (dry ground flour and wet aqueous slurry) were measured over the frequency range 500–2500 MHz. Temperature dependence of dielectric properties of rice flour slurries (20, 30 and 50 g flour per 100 g water yielding approximately 1:5, 1:3 and 1:2 flour to water ratio) were studied between 30 and 80 °C. Results indicated that dielectric constants ( ε′) generally did not vary with frequency while the loss factor ( ε″) showed an increasing trend. A sharp change in dielectric parameters were noted above 70 °C attributable to rice starch gelatinization, an observation confirmed later by differential scanning calorimetry. An increase in flour slurry concentration systematically reduced ε′ during the entire frequency range while variations in ε″ values were mixed. Addition of 1% salt markedly increased ε″ of slurries whereas butter resulted in significant reduction in ε′ values. Rice flour slurry containing both salt and butter exhibited intermediate values of dielectric properties. Both ε′ and ε″ data of rice slurries generally fitted a 2nd order polynomial relationship with temperature. These results suggest that dielectric measurements could be used to study frequency, concentration, ingredient and temperature dependent changes in starch–water systems during heating.

Digestive enzymes and metabolic profile of Labeo rohita fingerlings fed diets with different crude protein levels

Labeo rohita, commonly called rohu is one of the most important fish species for aquaculture in India. Digestive enzyme response and metabolic profile of fingerling L. rohita to different dietary crude protein (CP) levels (viz. 25, 30, 35 and 40%) were studied in an attempt to optimize a practical diet formulation for this species. After 45 days of feeding, activity of digestive enzymes and metabolite concentrations were assayed. Amylase, lipase and alkaline phosphatase (ALP) activities were not influenced by the dietary protein, but proteolytic and acid phosphatase (ACP) activities varied ( P < 0.05) between the treatments. Proteolytic activity showed a second order polynomial relationship with dietary crude protein (CP) as Y = 0.0734 X 2 + 4.937 X − 68.37, r 2 = 0.97. A positive correlation was observed between dietary CP and amylase ( r 2 = 0.78). All the metabolites except muscle glucose showed significant change corresponding to the dietary protein levels. Glucose and glycogen levels corresponded to the dietary carbohydrate levels. Muscle and plasma pyruvic acid increased as the crude protein in the diet increased, whereas liver pyruvic acid showed the opposite trend. Muscle protein content was not affected by dietary CP. Protein fractions in plasma (total protein, albumin and globulin) showed maximum values in 30% CP fed group. It is concluded that proteolytic activity and ACP are the major digestive enzymes responsive to dietary CP in L. rohita fingerlings. Considering the cost effectiveness of the diet, and based on liver and plasma free amino acid levels and plasma protein fractions, 30% crude protein is recommended as the optimal dietary protein for L. rohita fingerlings.

Determination of Specific Heat of Cloves using Differential Scanning Calorimetry

The knowledge of specific heat of cloves is useful to design cryogenic system for grinding and to simulate and model the heat transfer in the grinder. The paper reports measurement of specific heat of cloves at different moisture contents and temperatures using differential scanning calorimetry technique. The observed values of specific heat increased from 1932 to 2816 J/kgOC with increase in temperature from -60 to 60°C and moisture content from 3.8 to 18.8% (d.b.). The specific heat followed linear relationship with moisture content and second order polynomial relationship with temperature.

Tensile strength of sand, palygorskite and calcium carbonate mixtures and interpretation with the effective stress theory

Many soils in arid regions of the world including those of central Iran contain palygorskite and carbonates in their mineral fraction. There is, however, little information on the effects of these minerals on soil physical and mechanical behaviour. A laboratory experiment was carried out to evaluate tensile strength of artificial mixtures of sand–palygorskite–calcium carbonate (CaCO 3). Palygorskite and calcium carbonate were mixed with sand (1–0.05 mm) in proportions of 0, 5%, 10%, and 20% w/w for palygorskite and 0 and 30% w/w for CaCO 3. Tensile strength (ITS) of the mixtures was determined using the indirect (Brazilian) method. The ITS was measured at the matric suctions (− ψ m) of 30, 100, 300, 500 and 1000 kPa. Tensile strength of the similar mixtures was also determined at air-dry condition. Effective stress ( σ′) generated by matric suction was calculated as − χψ m where χ was assumed to be equal to the degree of saturation. The maximum value of ITS obtained at a matric suction depending on the amount of palygorskite and/or carbonate (fine particles) in the samples. The higher amount of the palygorskite or CaCO 3 in the mixtures pushed this point toward the higher matric suctions. For the all mixtures, ITS had a second order polynomial relationship with the matric suction meaning that ITS was maximum at an intermediate matric suction, and ITS declined at the lower or higher values. As matric suction increased, the fine particles could be pulled by water menisci to the points of contact between the larger (sand) particles. Subsequent shrinkage of the mixtures brought about mineral particles to be bonded together by capillary forces through the effective stress, which resulted in the higher strength. In addition, dissolution of carbonates upon saturation and subsequent precipitation during drying might be expected. The effect of 5% palygorskite on ITS was approximately similar to that of 30% CaCO 3. This might be due to the fibrous structure and the higher surface area of palygorskite as compared to CaCO 3. The fibrous units could act as binding bridges around and between the sand particles. The significant linear relation between ITS and σ′ (− χψ m) showed that internal stresses through the effective stress acting on particles are important forces affecting the strength or compaction of palygorskite and/or carbonates-containing soils.