Higher Root Mean Square Research Articles

The Effect of Boreal Forest Canopy in Satellite Snow Mapping—A Multisensor Analysis

Satellite-based snow-cover monitoring is performed using optical, synthetic aperture radar (SAR), and passivemicrowave sensors. Effects of forest canopy on the observed signal need to be considered with all of these sensor types. Various models describing the interaction of electromagnetic radiation with forest canopy have been developed, but many of these are overly complex with high computational and ancillary data requirements. However, for retrieval purposes, simple models are preferred. This work aims at increasing the understanding of the effect of forest canopy on remote sensing observations of snow-covered terrain for both microwave and optical regimes and at quantifying the capability of simple zeroth-order models in simulating these effects. To achieve these goals, a spatial analysis of optical, SAR, and passive-microwave remote sensing data in the northern boreal forest region was performed. Model parameters for vegetation transmissivity as well as the properties of the underlying surface were optimized by utilizing lidar-ranging- and Landsat-based simplified proxy parameters describing forest canopy closure and stem volume. The results demonstrated that despite using these relatively simple proxies, a zeroth-order model can accurately estimate the extinction of electromagnetic signals in a forest, particularly for passive microwave and optical data. The SAR model successfully estimated the median of the observations, but larger scatter of the observations was reflected by a higher root mean square error and lower correlation between models and observations. Due to both good estimation accuracy and simplicity, the presented models can be considered to be applicable in existing snow retrieval algorithms.

Symptoms of insomnia in patients with obstructive sleep apnea: Prevalence, correlates and association with suicidality

ternal and external 10-fold cross validation. Results: We analyzed 27,434 minutes (3599 minutes had OSA events). HRV analysis: OSA events showed higher sympathetic activity reflected by significantly higher normalized power at low frequencies (0.44 vs. 0.26), lower normalized power at high frequencies (0.51 vs. 0.70), lower mean of PP intervals (0.72 vs. 0.79), higher standard deviation of PP intervals (0.093 vs. 0.055) and higher root mean square of the difference of successive PP intervals (0.09 vs. 0.06). SpO2 characterization: Among other distinguishing parameters, OSA events had significantly greater SpO2 variability seen in higher standard deviation of SpO2 (1.33 vs. 0.56) and greater number of desaturations ≥4% from baseline (0.34 vs. 0.04) relative to Non-OSA. Spectral analysis of SpO2 showed higher normalized power at low frequencies in OSA events due to SpO2 modulation (0.81 vs. 0.45). The 10 most discriminating features were related to SpO2 modulation due to sleep apnea and HRV changes due to intermittent hypoxia. These features provided an accuracy of 81%, sensitivity of 80% and specificity of 81% identifying OSA events with a linear classifier. Conclusion: Combining SpO2 andHRV analysis enhances the detectionof OSAevents andhaspotential as an enhancedOSA screening tool. At-home screening will facilitate more natural sleep patterns with fewer disturbances, and reduce the burden to both families and the health system by screening patients prior to full PSG. Acknowledgements: This work was supported in part by The Natural Sciences and Engineering Research Council of Canada (NSERC), the Canadian Institutes of Health Research (CIHR) and the Child and Family Research Institute.

DETECTION AND QUANTIFICATION OF SOYBEAN AND CORN OILS AS ADULTERANTS IN AVOCADO OIL USING FOURIER TRANSFORM MID INFRARED (FT-MIR) SPECTROSCOPY AIDED WITH MULTIVARIATE CALIBRATION

Authentication of high value edible oils like avocado oil (AO) is an emerging issue. AO can be target of adulteration with low priced oils like soybean and corn oils. The present study is intended to quantify soybean oil (SO) and corn oil (CO) in avocado oil (AO) using the combination of Fourier transform mid infrared (FT-MIR) spectroscopy and chemometrics. The quantification was carried out by partial least square (PLS) calibration using some spectral processing, namely normal spectra, smoothing, and derivation treatment. Frequencies of 1427-779 cm-1 with normal spectra were suitable for the quantification of SO in AO which revealed high coefficient determination (R2), i.e. 0.9994 and low root mean square error of calibration (RMSEC), i.e 0.86% (v/v). Meanwhile, R2 of 0.9994 and RMSEC of 0.87% (v/v) were obtained by PLS at the combined spectra at frequency regions of 1477-721, 1728-1685, and 3035-2881 cm-1 for quantification of CO in AO. The model was further validated using independent samples and offered high R2 values of 0.9994 (for CO) and 0.9998 (for SO) with root mean square error of prediction (RMSEP) of 0.88% (v/v) (CO) and 0.52 % (v/v) (SO), respectively. In general, FT-MIR spectroscopy serves rapid and accurate determination of CO and SO in AO for authenticity studies.

Ultrasound assisted extraction of phenolic compounds from P. lentiscus L. leaves: Comparative study of artificial neural network (ANN) versus degree of experiment for prediction ability of phenolic compounds recovery

Design of experiments (DOE) based on central composite design (CCD) and artificial neural networks (ANNs) were efficaciously applied for the study of the operating parameters of ultrasound assisted extraction (UAE) in the recovery of phenolic compounds from P. lentiscus leaves. These models were used to evaluate the effects of process variables and their interaction toward the attainment of their optimum conditions. Under the optimal conditions (13.79min extraction time, 33.82 % amplitude and 30.99 % ethanol proportion), DOE and ANN models predicted a maximum response of 140.55 and 138.3452 mgGAE/gdw, respectively. A mean value of 142.76±19.98mgGAE/gdw, obtained from real experiments, demonstrated the validation of the extraction models. A comparison between the model results and experimental data gave high correlation coefficients (R2ANN=0.999, R2RSM=0.981), adjusted coefficients (RadjANN=0.999, RadjRSM=0.967) and low root mean square errors (RMSEANN=0.37 and RMSERSM=4.65) and showed that the two models were able to predict a total phenolic compounds (TPC) by green extraction ultrasound process. The results of ANN were found to be more consistent than DOE since better statistical parameters were obtained.

Dietary milk fat globule membrane supplementation combined with regular exercise improves skeletal muscle strength in healthy adults: a randomized double-blind, placebo-controlled, crossover trial.

BackgroundOur previous studies demonstrated that dietary supplementation with milk fat globule membrane (MFGM) combined with habitual exercise improved muscle strength by stimulating neuromuscular development in mice. This study aimed to demonstrate the beneficial effects of dietary MFGM supplementation plus regular exercise on muscle strength and neuromuscular function in healthy humans.MethodsThe study was designed as a randomized, double-blind, placebo-controlled, crossover trial. Fourteen Japanese adults aged 31–48 years took daily MFGM (1 g) or placebo tablets during the 4-week study period and attended a training program twice a week. Physical function tests and surface electromyography (EMG) were conducted at baseline and at the end of the study period.ResultsThe MFGM group had significantly greater leg extension strength than the placebo group after the 4-week study period. Surface EMG showed that the MFGM group had a significantly higher root mean square amplitude than the placebo group, which indicated that the MFGM group had higher motor unit activity.ConclusionsDietary MFGM supplementation combined with regular exercise improves skeletal muscle strength, which may be due to increased motor unit recruitment in healthy Japanese middle-aged adults.

Influence of Affective Stimuli on Leg Power Output and Associated Neuromuscular Parameters during Repeated High Intensity Cycling Exercises.

The aim of this study was to examine the impact of emotional eliciting pictures on neuromuscular performance during repetitive supramaximal cycling exercises (RSE). In a randomized order, twelve male participants were asked to perform five 6-s cycle sprints (interspaced by 24 s of recovery) on a cycle ergometer in front of neutral, pleasant or unpleasant pictures. During each RSE, mean power output (MPO) and electromyographic activity [root mean square (RMS) and median frequency (MF)] of the vastus lateralis and vastus medialis muscles were analyzed. Neuromuscular efficiency (NME) was calculated as the ratio of MPO to RMS. Higher RMS (232.17 ± 1.17 vs. 201.90 ± 0.47 μV) and MF (68.56 ± 1.78 vs. 64.18 ± 2.17 Hz) were obtained in pleasant compared to unpleasant conditions (p < 0.05). This emotional effect persisted from the first to the last sprint. Higher MPO was obtained in pleasant than in unpleasant conditions (690.65 ± 38.23 vs. 656.73 ± 35.95 W, p < 0.05). However, this emotional effect on MPO was observed only for the two first sprints. NME decreased from the third sprint (p < 0.05), which indicated the occurrence of peripheral fatigue after the two first sprints. These results suggested that, compared with unpleasant pictures, pleasant ones increased the neuromuscular performance during RSE. Moreover, the disappearance of the beneficial effect of pleasant emotion on mechanical output from the third sprint appears to be due to peripheral fatigue.

Functional Ser205Leu polymorphism of the nerve growth factor receptor (NGFR) gene is associated with vagal autonomic dysregulation in humans.

Evidence indicates that reduced cardiac vagal (parasympathetic) tone, a robust cardiovascular risk factor, is a trait vulnerability marker of major depressive disorder (MDD). The Ser205/Ser205 genotype of the functional polymorphism (Ser205Leu) of the nerve growth factor receptor (NGFR), also called p75 neurotrophin receptor (p75NTR), gene is reported to increase the risk of MDD. Here, we hypothesized that the NGFR Ser205Leu polymorphism may have an effect on vagal control. A sample of 810 healthy, drug-free, unrelated Han Chinese (413 males, 397 females; mean age 35.17 ± 8.53 years) was included in the NGFR genotyping. Short-term heart rate variability (HRV) was used to assess vagus-mediated autonomic function. Potential HRV covariates, such as mood/anxiety status and serum metabolic parameters, were assessed. Homozygotes of the Ser205 allele had significantly lower high frequency power and root mean square of successive heartbeat interval differences, both HRV indices of vagal modulation, compared to Leu205 allele carriers. Even after adjusting for relevant confounders, these associations remained significant. Further stratification by sex revealed that the associations were observed only in males. Our results implicate that decreased parasympathetic activity is associated with the NGFR Ser205/Ser205 genotype in a gender-specific manner, suggesting a potential role of NGFR polymorphism in modulating cardiac autonomic function.

Post-Process Modification of CeOx/C-Supported PtCu Thin Film Catalyst and Its Catalytic Activity for Hydrogen Evolution Reaction

CeO x/ C supported PtCu thin film catalysts were prepared by ion beam sputtering (IBS) and subsequently annealed at 400°C under vacuum environment and electrochemically dealloyed. Scanning transmission electronic microscope (STEM) and atomic force microscope (AFM) characterizations show that the surface of post-processed catalyst presents nanoporous structure and has a high root mean square roughness (RMS = 13.9nm). Electrochemical measurements indicate that the post-processed PtCu – CeO x/ C catalyst shows higher catalytic activity towards hydrogen evolution reaction than pure Pt / C . While inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis displays that the platinum ( Pt ) loading of the post-processed PtCu – CeO x/ C is 0.1192mg/cm2, decreasing by 20% compare to pure Pt / C (0.1490mg/cm2). X-ray photoelectron spectroscopy (XPS) analysis confirms that the surface of post-processed PtCu – CeO x/ C enrich Pt and analyzes the chemical valence of Pt element using depth profiling technology. It can be inferred that the enhancement in catalytic property is attributed to the combined action between geometric structure effect and electronic modification effect of Pt atoms from CeO x support.

Analysis of several methods and inertial sensors locations to assess gait parameters in able-bodied subjects

PurposeThe purpose of this paper was to determine which types of inertial sensors and which advocated locations should be used for reliable and accurate gait event detection and temporal parameter assessment in normal adults. In addition, we aimed to remove the ambiguity found in the literature of the definition of the initial contact (IC) from the lumbar accelerometer. Acceleration and angular velocity data was gathered from the lumbar region and the distal edge of each shank. This data was evaluated in comparison to an instrumented treadmill and an optoelectronic system during five treadmill speed sessions. ResultsThe lumbar accelerometer showed that the peak of the anteroposterior component was the most accurate for IC detection. Similarly, the valley that followed the peak of the vertical component was the most precise for terminal contact (TC) detection. Results based on ANOVA and Tukey tests showed that the set of inertial methods was suitable for temporal gait assessment and gait event detection in able-bodied subjects. For gait event detection, an exception was found with the shank accelerometer. The tool was suitable for temporal parameters assessment, despite the high root mean square error on the detection of IC (RMSEIC) and TC (RMSETC). The shank gyroscope was found to be as accurate as the kinematic method since the statistical tests revealed no significant difference between the two techniques for the RMSE off all gait events and temporal parameters. ConclusionThe lumbar and shank accelerometers were the most accurate alternative to the shank gyroscope for gait event detection and temporal parameters assessment, respectively.

A Review of ECG Data Compression Techniques

m (ECG) data compression reduced the storage requirements to develop a more efficient tele- cardiology system for cardiac analysis and diagnosis. The ECG compression without loss of diagnostic information is based on the fact that consecutive samples of the digitized ECG carry redundant information that can be removed with very less computing effort. This paper focuses on providing a comparison of the major techniques (direct, transform, parameter extraction and 2D approaches) of ECG data compression which are intended to attain a lossless compressed data with relatively high compression ratio (CR) and low percent root mean square difference (PRD).The paper concludes with the presentation of a framework for evaluation and comparison of ECG compression schemes. Keywordsm; ECG; Compression; CR; PRD; PRDN; QS

SF6/Ar plasma textured periodic glass surface morphologies with high transmittance and haze ratio of ITO:Zr films for amorphous silicon thin film solar cells

We report various SF6/Ar plasma textured periodic glass surface morphologies with high transmittance, haze ratio, and root mean square (rms) roughness of ITO:Zr films for amorphous silicon thin film solar cells (a-Si TFSCs). SF6/Ar plasma textured glass surface morphologies contain micro- and nano-textured features that help to scatter the light in visible and near infra-red (NIR) wavelength regions. We designed the textured glass surface morphologies with big square craters to smaller pyramids for various glass etching times from 30 to 75 min. Magnetron sputtered ITO:Zr (∼210 nm) films were deposited on textured glass surface morphologies and showed higher transmittance and haze ratio of 88.48% and 77.61%, respectively, in the visible-NIR (400–1100 nm) wavelength region. The sheet resistance and resistivity of ITO:Zr films decreased with the increase of etching time, due to high rms roughness and better step coverage. A passivation AZO (30 nm) layer was added to the ITO:Zr films, due to its better stability against hydrogen plasma exposure. The ITO:Zr/AZO films were employed as a front TCO layer and the current density–voltage (J–V) characteristics of a-Si TFSCs increased by light scattering effect, without any reduction in either the open circuit voltage (VOC) or the fill factor (FF). Relative to flat glass substrate, JSC and the efficiency of a-Si TFSCs were enhanced by 7.51% and 19.39%, respectively, for textured glass surface morphology.

Discovery of novel NAMPT inhibitors based on pharmacophore modeling and virtual screening techniques.

Nicotinamide phosphoribosyltransferase (NAMPT), an enzyme taking part in main NAD biosynthetic pathway, is an attractive target for anticancer therapy. The purpose of our study is to find novel NAMPT inhibitors based on in silico drug discovery means including the generation of 3D-QSAR models, and virtual screening techniques. Firstly, ten pharmacophore models were generated by Catalyst/HypoGen algorithm. Hypo1 with high correl value (0.96), large cost (77.77), and low root mean square deviation (0.81), featured by four chemical features was selected as the best one. Subsequently, Hypo1 was validated through test set prediction and Fischer's randomization methodologies. Then we screened some public compound libraries (Asinex, Ibscreen and Natural products database) using Hypo1 for a 3D query. The screened hits were further refined by Lipinski's rule of five, ADMET properties as well as molecular docking studies. Finally, six molecules with diverse scaffolds exhibited the right pharmacophore features and good binding modes between the receptor and ligands, and were selected as possible candidates against NAMPT for further study.

A Spatio-temporal disaggregation method to derive time series of Normalized Difference Vegetation Index and Land Surface Temperature at fine spatial resolution

Abstract. Estimation of evapotranspiration (ET) from remote sensing based energy balance models have evolved as a promising tool in the field of water resources management. Performance of energy balance models and reliability of ET estimates is decided by the availability of remote sensing data at high spatial and temporal resolutions. However huge tradeoff in the spatial and temporal resolution of satellite images act as major constraints in deriving ET at fine spatial and temporal resolution using remote sensing based energy balance models. Hence a need exists to derive finer resolution data from the available coarse resolution imagery, which could be applied to deliver ET estimates at scales to the range of individual fields. The current study employed a spatio-temporal disaggregation method to derive fine spatial resolution (60 m) images of NDVI by integrating the information in terms of crop phenology derived from time series of MODIS NDVI composites with fine resolution NDVI derived from a single AWiFS data acquired during the season. The disaggregated images of NDVI at fine resolution were used to disaggregate MODIS LST data at 960 m resolution to the scale of Landsat LST data at 60 m resolution. The robustness of the algorithm was verified by comparison of the disaggregated NDVI and LST with concurrent NDVI and LST images derived from Landsat ETM+. The results showed that disaggregated NDVI and LST images compared well with the concurrent NDVI and LST derived from ETM+ at fine resolution with a high Nash Sutcliffe Efficiency and low Root Mean Square Error. The proposed disaggregation method proves promising in generating time series of ET at fine resolution for effective water management.

Simulation of biomass yield and soil organic carbon under bioenergy sorghum production.

Developing sustainable management practices including appropriate residue removal and nitrogen (N) fertilization for bioenergy sorghum is critical. However, the effects of residue removal and N fertilization associated with bioenergy sorghum production on soil organic carbon (SOC) are less studied compared to other crops. The objective of our research was to assess the impacts of residue removal and N fertilization on biomass yield and SOC under biomass sorghum production. Field measurements were used to calibrate the DNDC model, then verified the model by comparing simulated results with measured results using the field management practices as agronomic inputs. Both residue removal and N fertilization affected bioenergy sorghum yields in some years. The average measured SOC at 0–50 cm across the treatments and the time-frame ranged from 47.5 to 78.7 Mg C ha−1, while the simulated SOC was from 56.3 to 67.3 Mg C ha−1. The high correlation coefficients (0.65 to 0.99) and low root mean square error (3 to 18) between measured and simulated values indicate the DNDC model accurately simulated the effects of residue removal with N fertilization on bioenergy sorghum production and SOC. The model predictions revealed that there is, in the long term, a trend for higher SOC under bioenergy sorghum production regardless of residue management.

Validation of molecular crystal structures from powder diffraction data with dispersion-corrected density functional theory (DFT-D).

In 2010 we energy-minimized 225 high-quality single-crystal (SX) structures with dispersion-corrected density functional theory (DFT-D) to establish a quantitative benchmark. For the current paper, 215 organic crystal structures determined from X-ray powder diffraction (XRPD) data and published in an IUCr journal were energy-minimized with DFT-D and compared to the SX benchmark. The on average slightly less accurate atomic coordinates of XRPD structures do lead to systematically higher root mean square Cartesian displacement (RMSCD) values upon energy minimization than for SX structures, but the RMSCD value is still a good indicator for the detection of structures that deserve a closer look. The upper RMSCD limit for a correct structure must be increased from 0.25 Å for SX structures to 0.35 Å for XRPD structures; the grey area must be extended from 0.30 to 0.40 Å. Based on the energy minimizations, three structures are re-refined to give more precise atomic coordinates. For six structures our calculations provide the missing positions for the H atoms, for five structures they provide corrected positions for some H atoms. Seven crystal structures showed a minor error for a non-H atom. For five structures the energy minimizations suggest a higher space-group symmetry. For the 225 SX structures, the only deviations observed upon energy minimization were three minor H-atom related issues. Preferred orientation is the most important cause of problems. A preferred-orientation correction is the only correction where the experimental data are modified to fit the model. We conclude that molecular crystal structures determined from powder diffraction data that are published in IUCr journals are of high quality, with less than 4% containing an error in a non-H atom.

Optimizing internal wave drag in a forward barotropic model with semidiurnal tides

A global tuning experiment for the semidiurnal tide is performed with a barotropic model. The model is forced with the M2 equilibrium tide and accounts for the self-attraction and loading (SAL) term. In addition to a quadratic drag, various linear internal wave drag terms adjusted by a scale factor of O(1) are applied. The drag terms include the original Nycander (2005) tensor scheme, the Nycander tensor scheme reduced at supercritical slopes, and their scalar sisters, a Nycander scalar scheme computed for additional abyssal hill roughness, and the Jayne and St. Laurent (2001) scalar scheme. The Nycander scheme does not have a tunable parameter, but to obtain the best tidal solutions, it is demonstrated that some tuning is unavoidable. It is shown that the scalar Nycander schemes yield slightly lower root-mean square (RMS) elevation errors vs. the data-assimilative TPXO tide model than the tensor schemes. Although the simulation with the optimally tuned original Nycander scalar yields dissipation rates close to TPXO, the RMS error is among the highest. The RMS error is lowered for the reduced schemes, which place relatively more dissipation in deeper water. The inclusion of abyssal hill roughness improves the regional agreement with TPXO dissipation rates, without changing the RMS errors. It is difficult to have each ocean basin optimally tuned with the application of a constant scale factor. The relatively high RMS error in the Atlantic Ocean is reduced with a spatially varying scale factor with a larger value in the Atlantic. Our best global mean RMS error of 4.4cm for areas deeper than 1000m and equatorward of 66° is among the lowest obtained in a forward barotropic tide model.

Low operating voltage n-channel organic field effect transistor using epoxy based photoresist gate dielectric

We report a systematic study on the dielectric properties of epoxy based positive tone photoresist and its use as a gate dielectric for n-channel organic field effect transistors (OFETs) made with N,N’-Dioctyl-3,4,9,10-perylenedicarboximinde (PTCDI-C8) as the active semiconducting layer. We find that the photoresist has high dielectric constant (k = 12 at 10 kHz) and thus can be used in fabricating low operating voltage OFET devices. Highly smooth gate dielectric surface was obtained using the photoresist with the highest root mean square (rms) roughness of 0.239 nm for the films annealed at 200 °C. Consequently, the semiconducting layer (on photoresist dielectric annealed at 100 °C) also exhibited highly uniform surface with rms roughness of 0.382 nm. The turn-on voltage (VT), inverse subthreshold slope (S) and saturation mobility of electrons (μsat) of the transistor device were estimated to be 4.3 V, 13 V decade−1 and 6 × 10−5 cm2 Vs−1, respectively, when the device was operated in ambient, which is better than some of the earlier reported works under similar experimental conditions.

Quantification of vibrations during mountain biking

Background:  During cross-country mountain biking, riders are subjected to vibrations due to the terrain, which must be damped before reaching the central nervous system.  Damping vibrations requires work, which may help to explain the decrease in economy for mountain biking as compared to road cycling (Titlestad et al., 2006 Journal of Sports Sciences, 24(2), 125-135).  Purpose: To describe the relationship between vibration mechanics and their interaction with terrain, bicycle and rider during a race pace effort on a cross country mountain bike track.  Methods: Participants (n=8) completed two separate laps on a cross country track using 26” and 29” wheels, at race speed. Power, cadence, speed, heart rate, and geographical position were sampled and logged every second for control purposes. Tri-axial accelerometers located at handlebar centre, lower left arm, lower left leg, seat post, lower back and medial forehead, recorded accelerations with a output rate 128 Hz to measure vibrations experienced during the whole lap and over terrain sections (uphill and downhill). Vibrations were quantified using a root mean square (RMS) and using Fourier analyses.  Results: RMS data showed greater total accelerations for 29” vs 26” wheels (p=0.0020), and a significant interaction of terrain and accelerometer location (p<.0001). While climbing, accelerations were generally low and concentrated at low movement frequencies. While descending, however, high RMS values were seen on the bicycle (handlebar and seat post) and the parts of the body near the interface with the bicycle (left arm and left leg), while lower accelerations at the lower back and head were not significantly different than the accelerations during climbing.  In addition, Fourier analyses showed that the accelerations occurred at a higher frequency when compared to uphill sections.  No differences between overall power output (p=0.3062) and heart rate (p=0.8423), yet overall time was greater for 26” compared to 29” wheels (p=0.0061). Discussion: The results show that mountain bikers are subjected to large accelerations, or vibrations, particularly during downhill sections.  These vibrations are damped before reaching the lower back and head, which requires metabolic work.  In addition, 29 inch wheels showed a clear performance advantage, going faster for the same average power, although resulting in greater vibrations for the riders.  Conclusion: This study demonstrates an additional non-propulsive, muscular challenge to riding during cross country mountain biking represented by a change in accelerations at the point of interface between bike-body compared to lower back and head.

The use of visible and near infrared spectroscopy for evaluating passion fruit postharvest quality

Visible and short-wave near infrared spectroscopy (Vis/SWNIRS) was investigated using a non-destructive method for evaluating passion fruit quality. In this study, interactance and transmission measurements were performed and their competences were compared. Prediction models of soluble solids content (SSC), titratable acidity (TA), ascorbic acid content (ASC), ethanol concentration (EtOH), peel firmness (PF) and pulp percentage (PP) were developed based on multivariate methods of partial least square regression (PLSR) analysis. The PLS models from interactance measurements provided better prediction results than the transmission technique. The best model was obtained from interactance SSC calibration with a correlation coefficient between measured and predicted values (R) of 0.923. Furthermore, the PLS models generated from interactance and transmission spectra also provided satisfactorily prediction results for EtOH, PF and PP. However, all calibrations failed to predict ASC by providing low correlations and high root mean square errors of prediction (RMSEP).

Determining and modeling rheological characteristics of quince seed gum

In this research, rheological characteristics of quince seed gum were investigated. To describe shear thinning behavior, Cross model with high determination coefficient (R2) and low root mean square deviation (RMSE) was applied at shear rate of 0.01–1000 (s−1) and concentration range of 0.01–0.7 (%, w/w). Using Arrhenius model, activation energy was estimated to be 6988.74 J mol−1in the gum solution (0.3%) and temperature range of 25–55 °C. Linear viscoelastic range of the gum solution (0.3%, w/w) in the presence and absence of 0.2 M NaCl was measured as 11.4% and 7.7%, respectively. Loss and storage moduli of the gum solution (0.3%, w/w) at frequencies of 0.01–100 (Hz) showed that, at all of these frequencies, storage modulus was more than loss modulus and both of them increased with increase of frequency. Critical polymer concentration (C∗) was determined as 0.077 g 100 ml−1 through slopes of the lines for dilute and semi-dilute regions in concentration range of 0.01–0.7 (%, w/w). Capillary viscometer determined intrinsic viscosity and Huggins constant of quince seed gum as 1530 ml/g and 0.32, respectively.