Physical and viscoelastic properties of carrots during drying

It is essential to understand the physical and mechanical properties of a product since these properties affect the structure, texture, and ultimately consumer acceptance. The effect of drying conditions on dynamic viscoelastic properties, stress relaxation function and creep compliance, and physical properties, such as moisture distribution, color parameters, and shrinkage, was studied. An increase in drying temperature and duration resulted in a decrease in moisture content and volume, which were highly correlated (R = .988). Water evaporation followed the falling rate period, demonstrating that the water transport was limited by internal resistances. The decomposition of carotenoids led to a decrease in magnitude of color parameters (L, a, and b), between 30.1% and 51.6% with 4 hr drying. It was observed that the material shrinkage and moisture content highly affected the mechanical properties; increased stress relaxation modulus and decreased creep compliance values of the sample. The creep behavior, expressed with Burger's model (R² ≥ .986), was highly dependent on moisture content. The linear viscoelastic region of carrots was found to be at strains lower than 3%. The three-element Maxwell model well fitted to describe the viscoelastic behavior of carrots (R² ≥ .999, RMSE ≤ 2.08 × 10⁻⁴). The storage moduli (G′) were higher than loss moduli (G″), indicating that samples presented solid-like behavior. The findings can be used to improve the textural attributes of carrots and carrot-based products.     

Increasing the separation of block cryoconcentration through a novel centrifugal filter-based method

The objective of this work was to evaluate the filter addition in centrifugal cryoconcentration. The cryoconcentration process was optimized by Response Surface Method using initial concentration (C₀) and centrifugation speed (CS) (independent variables) and efficiency (η), percentage of concentrate (PC) and solute yield (Y) (dependent variables), under radial and axial freezing conditions. The optimal interactions were 5 (wt.%), 3850 rpm and axial condition, with high final solute concentration, and extraordinary separation, with 86%, 63% and 0.87 (kg/kg) for η, PC and Y, respectively. Therefore, the centrifugal filter cryoconcentration allowed the migration of solutes between the crystals, and the filter improved the separation and elution process of the concentrated solution from the ice.     

Haematological parameters and HbA2 levels in beta-thalassaemia trait with coincident iron deficiency

In the 1970s, Semm developed thermocoagulation, adapted the Roeder Loop, and further invented extra- and intracoporeal endoscopic knotting to achieve endoscopic hemostasis. His numerous technical inventions, especially the electronic insufflator, allowed more complex operations to be performed laparoscopically. His technique, however, was not quickly adopted by the surgical community. When the first fully laparoscopic appendectomy was carried out by Semm in 1980, a veritable storm broke loose. In the opinion of many prominent surgeons, Semm exaggerated the problem of adhesions, and laparoscopic technique itself was regarded as very dangerous. Misunderstood by medical scientists, Semm displayed an ability to force his ideas through despite skepticism and suspicion. He realized that endoscopic surgery had tremendous potential, and promoted laparoscopic technique not only in his field of gynecology but among general surgeons as well. In 1985, Muhe, of Boblingen, Germany, used Semm's technique to remove the first gallbladder in the world laparoscopically. Three years later when Semm presented a videotape of his laparoscopic appendectomy in Baltimore, he gave impetus to McKernan and Save of Marietta. Georgia, to carry out the first laparoscopic cholecystectomy in the United States.     

Band theory analysis of shock velocity-particle velocity relations for metals

The systematics of the shock constants in shock velocity-particle velocity relations for metals have been examined by energy band theory methods. The causes of non-linearity of this relation at high pressure are discussed in terms ofs ⇌d electron transfer.     

Reactive spraying of nickel-aluminide coatings

Reactive spraying of nickel aluminides was accomplished via reaction synthesis techniques in which nickel and aluminum powders were fed through a direct- current plasma torch onto carbon steel substrates. The as- sprayed coatings obtained by reactive spraying were characterized by x- ray diffraction and microscopic techniques. Reactive spraying of nickel and aluminum resulted in coatings consisting of Ni, Al, Ni ₃Al, NiAl₃, Ni₅Al₃, NiAl, and Al₂O₃, depending on the experimental conditions. Nickel aluminide phases observed in plasma spray depositions were compared with the phases obtained by combustion synthesis techniques, and the formation of phases in reactive spraying was attributed to the exothermic reaction between splats of aluminum and nickel. Primary and secondary reactions leading to the formation of nickel aluminides were also examined. The splat thickness and the reaction layer suppressed the formation of desired equilibrium phases such as Ni₃Al and NiAl. As- sprayed coatings were annealed to enhance the diffusional reactions between the product phases and aluminum and nickel. Coatings obtained by reactive spraying of elemental powders were compared with as- sprayed and annealed coatings obtained with a bond coat material in which nickel was deposited onto aluminum particles.     

Flexible and Ultrasoft Inorganic 1D Semiconductor and Heterostructure Systems Based on SnIP

Low dimensionality and high flexibility are key demands for flexible electronic semiconductor devices. SnIP, the first atomic‐scale double helical semiconductor combines structural anisotropy and robustness with exceptional electronic properties. The benefit of the double helix, combined with a diverse structure on the nanoscale, ranging from strong covalent bonding to weak van der Waals interactions, and the large structure and property anisotropy offer substantial potential for applications in energy conversion and water splitting. It represents the next logical step in downscaling the inorganic semiconductors from classical 3D systems, via 2D semiconductors like MXenes or transition metal dichalcogenides, to the first downsizeable, polymer‐like atomic‐scale 1D semiconductor SnIP. SnIP shows intriguing mechanical properties featuring a bulk modulus three times lower than any IV, III‐V, or II‐VI semiconductor. In situ bending tests substantiate that pure SnIP fibers can be bent without an effect on their bonding properties. Organic and inorganic hybrids are prepared illustrating that SnIP is a candidate to fabricate flexible 1D composites for energy conversion and water splitting applications. SnIP@C₃N₄ hybrid forms an unusual soft material core–shell topology with graphenic carbon nitride wrapping around SnIP. A 1D van der Waals heterostructure is formed capable of performing effective water splitting.     

Text-independent speaker identification using Radon and discrete cosine transforms based features from speech spectrogram

This paper presents a new feature extraction technique for speaker recognition using Radon transform (RT) and discrete cosine transform (DCT). The spectrogram is compact, efficient in representation and carries information about acoustic features in the form of pattern. In the proposed method, speaker specific features have been extracted by applying image processing techniques to the pattern available in the spectrogram. Radon transform has been used to derive the effective acoustic features from the speech spectrogram. Radon transform adds up the pixel values in the given image along a straight line in a particular direction and at a specific displacement. The proposed technique computes Radon projections for seven orientations and captures the acoustic characteristics of the spectrogram. DCT applied on Radon projections yields low dimensional feature vector. The technique is computationally efficient, text-independent, robust to session variations and insensitive to additive noise. The performance of the proposed algorithm has been evaluated using the Texas Instruments and Massachusetts Institute of Technology (TIMIT) and our own created Shri Guru Gobind Singhji (SGGS) databases. The recognition rate of the proposed algorithm on TIMIT database (consisting of 630 speakers) is 96.69% and for SGGS database (consisting of 151 speakers) is 98.41%. These results highlight the superiority of the proposed method over some of the existing algorithms.     

Thermomechanically stable dielectric composites based on poly(ether ketone) and BaTiO3 with improved electromagnetic shielding properties in X‐band

High‐performance barium titanate (BaTiO₃) filled poly(ether ketone) (PEK) composites were prepared by melt compounding with an aim to investigate the effect of BaTiO₃ on thermal, thermomechanical, dielectric, and electromagnetic interference shielding behavior of PEK. The content of BaTiO₃ in the PEK matrix was varied from 0 to 18 vol %. Scanning electron microscopy studies shows that BaTiO₃ particles were uniformly distributed in the PEK matrix up to 13 vol % loading followed by the formation of agglomerates at higher loading (18 vol %). Rockwell hardness increased up to 13 vol % loading followed by a decrease at 18 vol % loading. Dynamic mechanical analysis revealed that storage modulus increases with increase in BaTiO₃ loading with a maximum value of 3192 MPa at 13 vol % compared to 2099 MPa for neat PEK. Dielectric constant of composites measured in the frequency range of 8.2–12.4 GHz increased approximately three times upon incorporation of 18 vol % of BaTiO₃. This increment in dielectric constant is reflected in improved electromagnetic shielding properties as loading of dielectric filler (BaTiO₃) increases. Total shielding effectiveness of ?11 dB (～92% attenuation) at loading of 18 vol % BaTiO₃ justifies the use of these composites for suppression of EM radiations. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46413.