Nondissipative Martensitic Phase Transformation after Multimillion Superelastic Cycles.

Superelastic alloys used for stents, biomedical implants, and solid-state cooling devices rely on their reversible stress-induced martensitic transformations. These applications require the alloy to sustain high deformability over millions of cycles without failure. Here, we report an alloy capable of enduring 10×10^{7} tensile stress-induced phase transformations while still exhibiting over 2% recoverable elastic strains. After millions of cycles, the alloy is highly reversible with zero stress hysteresis. We show that the major martensite variant is reversible even after multimillions of cycles under tensile loadings with a highly coherent (11[over ¯]0)_{A} interface. This discovery provides new insights into martensitic transformation, and may guide the development of superelastic alloys for multimillion cycling applications.

Fabrication of UF-white cheese: Obtaining a different proteolysis rate, texture, and flavor via using combinations of mesophilic starter culture and Lactobacillus helveticus.

The effect of using mesophilic starter culture (Lactococcus lactis ssp. lactis and Lactococcus lactis ssp. cremoris) and Lactobacillus helveticus (L. helveticus) at different ratios (100:0, 75:25, 50:50, 25:75, and 0:100) on the quality properties of UF-white cheese during 90 days of ripening was studied. The results revealed that an increase in L. helveticus ratio caused a significant decrease in the pH and total protein contents of the cheeses (p < .05). No significant changes were observed in the dry matter content of the cheeses (p > .05). The use of higher ratios of L. helveticus led to a noticeable increase in proteolysis and lipolysis indices in the cheeses (p < .05). The cheese produced with higher ratios of L. helveticus had less storage (G') and loss (G″) moduli compared to other cheeses. The more open structure was seen in the cheeses produced using higher ratios of L. helveticus. Regarding sensory properties, lower scores of body and texture, and higher scores of odor and flavor were assigned to the cheeses produced using higher ratios of L. helveticus. In conclusion, the use of combinations of mesophilic starter culture and L. helveticus at specific ratios (75:25 and 25:75) led to improve quality characteristics of UF-white cheese.

Rheological properties of carboxymethyl cellulose (CMC) solution: Impact of high intensity ultrasound.

Today sonication process is used as a new green tool with unique impacts on foods preservation and processing. Ultrasonic modification is an appropriate strategy to obtain good gums with useful physicochemical characteristics and molecular structure. This research aimed to analyze the impacts of sonication at different intensities (0, 75, and 150 W) and time (0, 5, 10, 15, and 20 min) on the viscosity and rheological characteristics of carboxymethyl cellulose (CMC) solution. The results confirmed that the apparent viscosity of CMC solution reduced from 0.030 to 0.021 Pa.s with increasing shear-rate from 12.2 s-1 to 134.5 s-1 (75 W for 10 min). Also, the apparent viscosity of CMC solution reduced from 0.028 to 0.019 Pa.s with enhancing the sonication time from 0 to 20 min (shear-rate = 61 s-1, 150 W). Various rheological equations were employed to fit the empirical values, and the results confirmed that the Power law model was the best fit to explain the flow behaviour of CMC solution. The consistency coefficient of CMC solution significantly reduced from 0.065 Pa.sn to 0.032 Pa.sn (p < 0.05) with enhancing sonication time from 0 to 20 min (75 W). Furthermore, the consistency coefficient of CMC solution decreased significantly (p < 0.05) while the ultrasonic power enhanced. Flow behaviour index of CMC solution enhanced significantly (p < 0.05) while the intensity and time of sonication enhanced.

Effect of whey protein- and xanthan-based coating on the viability of microencapsulated Lactobacillus acidophilus and physiochemical, textural, and sensorial properties of yogurt.

The goal of this study was to investigate the viability of microencapsulated and coated Lactobacillus acidophilus in yogurt during storage in a refrigerator for 28 days and in simulated gastrointestinal conditions. Furthermore, the effect of the microencapsulated and coated L. acidophilus on the physicochemical, textural, and sensory properties of yogurt was assessed. Lactobacillus acidophilus was microencapsulated in sodium alginate and coated with xanthan and/or whey protein. The coating led to the increase in the microcapsule diameter and the microencapsulation yield, while it led to the decreased moisture and water activity (aw) of the microcapsule. The survival of L. acidophilus microcapsule coated with whey protein and xanthan in yogurt during storage and exposure to simulated gastrointestinal conditions was significantly increased. Compared with free bacteria, the L. acidophilus microcapsule coated with whey protein and xanthan had the increased viability in yogurt until 2.16 log CFU/g during storage and 3.52 log CFU/g in simulated gastrointestinal conditions. After the 28th day of storage, a significant difference between the acidity and pH of yogurt containing coated and microencapsulated L. acidophilus and control yogurt was not observed. However, yogurt containing free L. acidophilus had lower pH and higher acidity and showed a significant difference (p < .05) with other samples. Although the coating of L. acidophilus microcapsule did not affect the sensory properties and gumminess of yogurt, it increased the firmness, adhesiveness, and viscosity of this product and caused a significant decrease in syneresis and cohesiveness. In general, the application of whey protein and xanthan coating on L. acidophilus microcapsule surface could increase the viability of this probiotic in yogurt during storage and in simulated gastrointestinal conditions and improve the texture attributes of yogurt.

Production of Low-fat mayonnaise without preservatives: Using the ultrasonic process and investigating of microbial and physicochemical properties of the resultant product.

In this study, ultrasonication was used at 20 kHz, 750 W for 5 min, as a nonthermal alternative to pasteurization and as a substitute for benzoate-sorbate preservatives. Also, its efficiency on microbial and physicochemical properties of low-fat mayonnaise stored at 4°C was investigated. The results showed the reduction of total counts of micro-organisms, acid-tolerant bacteria, molds, and yeasts during six months shelf life compared with the control samples. Sonicated mayonnaise samples had lower pH values and higher acidity in comparison with control samples during the storage. The speculation was verified through the microstructure of mayonnaise samples during storage time observed by SEM micrographs. The overall results indicated that it was possible to produce sodium benzoate and potassium sorbate-free mayonnaise using the ultrasonic nonthermal method.

Two-Tier Compatibility of Superelastic Bicrystal Micropillar at Grain Boundary.

Both crystallographic compatibility and grain engineering are super critical to the functionality of shape memory alloys, especially at micro- and nanoscales. Here, we report a bicrystal CuAl24Mn9 micropillar engraved at a high-angle grain boundary (GB) that exhibits enhanced reversibility under very demanding driving stress (about 600 MPa) over 10 000 transformation cycles despite its lattice parameters are far from satisfying any crystallographic compatibility conditions. We propose a new compatibility criterion regarding the GB for textured shape memory alloys, which suggests that the formation of GB compatible twin laminates in neighboring textured grains activates an interlock mechanism, which prevents dislocations from slipping across GB.

Derived crystal structure of martensitic materials by solid-solid phase transformation.

A mathematical description of crystal structure is proposed consisting of two parts: the underlying translational periodicity and the distinct atomic positions up to the symmetry operations in the unit cell, consistent with the International Tables for Crystallography. By the Cauchy-Born hypothesis, such a description can be integrated with the theory of continuum mechanics to calculate a derived crystal structure produced by solid-solid phase transformation. In addition, the expressions for the orientation relationship between the parent lattice and the derived lattice are generalized. The derived structure rationalizes the lattice parameters and the general equivalent atomic positions that assist the indexing process of X-ray diffraction analysis for low-symmetry martensitic materials undergoing phase transformation. The analysis is demonstrated in a CuAlMn shape memory alloy. From its austenite phase (L21 face-centered cubic structure), it is identified that the derived martensitic structure has orthorhombic symmetry Pmmn with the derived lattice parameters ad = 4.36491, bd = 5.40865 and cd = 4.2402 Å, by which the complicated X-ray Laue diffraction pattern can be well indexed, and the orientation relationship can be verified.

Data-driven approach for synchrotron X-ray Laue microdiffraction scan analysis.

A novel data-driven approach is proposed for analyzing synchrotron Laue X-ray microdiffraction scans based on machine learning algorithms. The basic architecture and major components of the method are formulated mathematically. It is demonstrated through typical examples including polycrystalline BaTiO3, multiphase transforming alloys and finely twinned martensite. The computational pipeline is implemented for beamline 12.3.2 at the Advanced Light Source, Lawrence Berkeley National Laboratory. The conventional analytical pathway for X-ray diffraction scans is based on a slow pattern-by-pattern crystal indexing process. This work provides a new way for analyzing X-ray diffraction 2D patterns, independent of the indexing process, and motivates further studies of X-ray diffraction patterns from the machine learning perspective for the development of suitable feature extraction, clustering and labeling algorithms.

Protein beverages made of a mixture of egg white and chocolate milk: Microbiology, nutritional and sensory properties.

Egg white protein and chocolate milk were used for making protein beverage. Microbiological count, sensory attributes, and pH changes were investigated during 10 days of refrigerated storage. At the tenth day, the total numbers of bacteria were between 4.05 and 5.77 (Log CFU/ml). It was concluded that when the amount of egg white increases, the number of bacteria significantly decreases. No coliforms, E. coli, salmonella, mold, and yeast were observed. Also, pH levels were increased from 8.3 to 8.7 and acidic spoilage was reduced. The chocolate milk containing 14% egg white was the most preferred by the panelists in all of the evaluated items except texture. Protein, Ca, Na, and energy contents were increased, and fat, cholesterol, saturated fatty acids, total sugar, lactose, carbohydrate, Mg, Fe, and P contents of the treated samples were decreased.

Physicochemical and sensory attributes assessment of functional low-fat yogurt produced by incorporation of barley bran and Lactobacillus acidophilus.

The aim of this study was to analyze the effect of different amounts of barley bran (0.3%, 0.6%, 0.9%, and 1.2%) on the viability of Lactobacillus acidophilus and the physicochemical and sensory properties of low-fat yogurt during storage period (28 days). Results showed that L. acidophilus number and viscosity in samples containing barley bran was significantly higher than the control group (p < .05). High levels of barley bran (1.2%) decreased sensory prosperity scores and led to viscosity increment; although sensory prosperity scores of samples containing 0.6% barley bran did not show significant difference with control sample, while the number of L. acidophilus in this treatment was higher than minimal acceptable level (106 CFU/g). Therefore, level of 0.6% of barley bran is recommended for symbiotic yogurt production. According to the present study, a positive correlation was observed between barley bran concentrations in the yogurt with L. acidophilus number.