Color space transformations for digital photography exploiting information about the illuminant estimation process

The color reproduction accuracy is a key factor to the overall perceived image quality in digital photography. In this framework, both the illuminant estimation process and the color correction matrix concur in the formation of the overall perceived image quality. To the best of our knowledge, the two processes have always been studied separately, thus ignoring the interactions between them. We investigate here these interactions, showing how the color correction transform amplifies the illuminant estimation errors. We demonstrate that incorporating knowledge about the illuminant estimation behavior in the optimization of the color correction matrix makes it possible to alleviate the error amplification. Different strategies to improve color accuracy under both perfect and imperfect white point estimations are investigated, and the experimental results obtained with a digital camera simulator are reported.     

Effect of drawing on the dielectric properties and polarization of pressed solution cast β-PVDF films

Poly(vinylidene fluoride), PVDF, samples containing exclusively the polar β phase were obtained by crystallization from N,N-dimethylformamide (DMF) solution at 60 °C and subsequent pressing. Some of these samples were uniaxially drawn at 120 °C at draw ratio of 4, resulting in oriented films. Oriented and unoriented samples were characterized as to relative fraction of β phase, degree of crystallinity and orientation by infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and wide-angle X-ray diffraction (WAXD). The dependence on frequency of the real ( e_\textr^￠ \varepsilon_{\text{r}}^{\prime} ) and imaginary ( e_\textr^￠￠ \varepsilon_{\text{r}}^{\prime\prime} ) components of the relative permittivity of the samples was determined between 10⁴ and 1.7 × 10⁷ Hz. The coercive field and stable and metastable remanent ferroelectric polarization were determined from the hysteresis loop obtained by the ramp voltage technique, described in detail in this work. The results allowed verification of the effect of drawing on structure and of the resulting structure on the dielectric properties, remanent polarization, and coercive field of β-PVDF. A possible effect of the crystal–amorphous interphase region on the metastable remanent polarization is suggested. The results obtained with the oriented and unoriented samples were compared with those obtained for films commercialized by Piezotech S.A.     

Thermal and structural study of nanocrystalline Fe(Co)NiZrB alloys prepared by mechanical alloying

Three nanocrystalline alloys, Fe_75−x Co _x (Ni₇₀Zr₃₀)₁₅B₁₀ (x = 0, 10, and 20), were synthesized from elemental powders in a planetary high-energy ball mill. Their microstructure, magnetic properties, and thermal stability were characterized by X-ray diffraction, transmission M?ssbauer spectroscopy, transmission electron microscopy, scanning electron microscopy, induction coupled plasma, vibrating sample magnetometry, and differential scanning calorimetry. After 80 h of milling, the nanocrystallites size of alloys is in the range 6–10 ± 1 nm. The lattice parameter decreases when increasing (decreasing) milling time (Fe content). Furthermore, the thermal stability of the nanocrystalline phase increases when increasing Co concentration. The activation energy of the main crystallization process, between 275 ± 8 and 311 ± 10 kJ mol⁻¹, is associated with grain growth. Slight contamination from milling tools and milling atmosphere was detected. Minor differences were detected after M?ssbauer analysis.     

Thermal damage during ablation of biological tissues

This study presents the numerical solution of a bioheat transfer problem related to the ablation of biological tissues continuously heated by a laser. Different mechanisms of thermal decomposition, such as coagulation, vaporization, and removal of the necrotic tissues, were taken into account in the analysis. The finite volume method was used to obtain the numerical solution of the temperature field, while the volume of fluid method was used to track the ablation interface. Results obtained for cases of practical interest provide a good indication of the area affected by the thermal treatment and are in good agreement with experimental data available in the literature.     

Integrating an automated activity monitor into an artificial insemination program and the associated risk factors affecting reproductive performance of dairy cows

The aim of this study was to compare 2 reproductive programs for the management of first postpartum artificial insemination (AI) based on activity monitors and timed AI, as well as to determine the effect of health-related factors on detection and expression of estrus. Lactating Holstein cows (n = 918) from 2 commercial farms were enrolled. Estrous cycles of all cows were presynchronized with 2 injections of PGF_2α administered 2 wk apart. Treatments were (1) first insemination performed by timed AI (TAI) and (2) first insemination based upon the detection of estrus by activity monitors (ACT; Heatime, SCR Engineering, Netanya, Israel) after the presynchronization, whereas cows not inseminated by the detection of estrus were enrolled in the Ovsynch protocol. Body condition score (BCS; scale 1 to 5), hock score (scale: 1 to 4), gait score (scale: 1 to 4), and corpus luteum presence detected by ovarian ultrasonography were recorded twice during the presynchronization. On the ACT treatment, 50.5% of cows were inseminated based on detected estrus, whereas 83.2% of the cows on the TAI treatment were inseminated appropriately after the timed AI protocol. Pregnancy per AI did not differ by treatment (30.8 vs. 33.5% for ACT and TAI, respectively). Success of pregnancy was affected by parity, cyclicity, BCS, milk production, and a tendency for leg health. In addition, treatment × cyclicity and treatment × parity interactions were found to affect pregnancy success, where anovulatory cows and older cows had compromised pregnancy outcomes on the ACT treatment but not on the TAI treatment. Factors affecting pregnancy outcomes varied among farms. Hazard of pregnancy by 300 DIM was affected by farm, parity, BCS, a treatment × cyclicity interaction, and a tendency for an interaction between leg health and farm. Detection of estrus was affected by farm, parity, cyclicity, and leg health, but not BCS or milk production. Expression of estrus was compromised in anovular and older cows, and by the timing of the estrus event, but not by gait score, BCS, or milk production. Increased duration of estrus, but not intensity of estrus, improved pregnancy per AI. In conclusion, using an automated activity monitor for the detection of estrus within a Presynch-Ovsynch program resulted in similar pregnancy per AI and days open compared with a reproduction program that was strictly based on timed AI for first postpartum AI. In contrast, notable variations in reproductive outcomes were detected between farms, suggesting that the use of automated activity monitors is prone to individual farm management.     

The Influence of the Rebaudioside A Content of Stevia (Stevia rebaudiana Bertoni) on the Determination of Sweetness Equivalence in Bittersweet Chocolates,Using the Time‐Intensity Analysis

The consumption of diet products has increased greatly in recent years. The objectives of the study were to develop a bittersweet chocolate added inulin and stevias with different rebaudioside A contents (60%, 80%, and 97%). Five chocolate samples were formulated with different sucrose concentrations to determine the ideal sucrose concentration for bittersweet chocolate. The use of just‐about‐right scale identified an ideal sucrose concentration of 47.5% (w/w). The sweetness equivalence in sugar‐free bittersweet chocolates was determined by the time–intensity method by 14 selected and trained judges. The data collected during each session of sensory evaluation furnished the following parameters in relation to the sweet stimulus: Imax (maximum intensity recorded), Timax (time at which the maximum intensity was recorded), Area (area of time × intensity curve), and Ttot (total duration time of the stimulus). The time–intensity analysis indicated that the percentages of rebaudioside A did not interfere with the sweetness intensity of the sweetener stevia in bittersweet chocolate and there was no significant difference in the concentrations tested (0.16%, 0.22%, 0.27%) of each stevia, in relation to the parameters evaluated. In addition, the reduction in fat content did not alter the perception of the sweetness intensity of the samples. These results showed important information to research and development of chocolate products. Therefore, the use of the lowest stevia concentration tested (0.16%) is the most indicated for use, since this quantity was sufficient to reach the ideal sweetness of the product, so there was no point in adding more.     

Phytochemistry Profile,Nutritional Properties and Pharmacological Activities of Mauritia flexuosa

Mauritia flexuosa L. (Arecaceae) is a popular Brazilian fruit known as “buriti” and belonging to the category of functional foods. This work reviewed the phytochemistry profile, nutritional and pharmacological activities of M. flexuosa. The main bioactive compounds reported to buriti were carotenoids, tocopherols, ascorbic acid, phenolic compounds, fiber, phytosterols, and mono‐ and poly‐unsaturated fatty acids. These compounds were mainly related to antioxidant, hypolipemiant, photoprotector, antiaggregant, antithrombotic, anti‐inflammatory, hypoglycemiant, antimicrobial, and antitumor activities. Furthermore, some compounds present in buriti fruit and its properties were tested in vitro and in vivo and showed biotechnology applications, especially for extraction of fiber, polysaccharides, pigments, antioxidants, and oil. Howerer, the buriti fruit shows great relevance to the development of new products in food, pharmaceutical and chemical industry, this fruit is still underexploited and it has need to expand its production chain and processing to encourage their consumption and utilization.