Using the mixture design approach to predict the rheological properties of low-calorie dairy desserts containing gum tragacanth exuded by three Iranian Astragalus species

Food Science and Biotechnology - In this study, the flow behavior and creep parameters of saffron desserts containing gum tragacanth combinations of three species were modeled by the mixture design...     

Correction of seismic time-lapse data with different geometries

In the interpretation of time-lapse seismic data, we first assume that basal and monitor seismic data have been gathered and processed under equal condition. Basically having two sets of seismic data (basal and monitor data) does not confirm the possibility of 4D seismic data analysis and repeatability term commands that data should have equal data gathering and process condition. This is due to the low vertical resolution of seismic data which makes the changes in amplitude of seismic in basal and monitoring operations to occur finitely. Therefore, differences in amplitudes in two seismic surveys that have a source other than variations in reserval fluid saturation cause errors in 4D interpretations. In this paper, we represent a procedure to unify different geometries and also study post-stack processing methods for seismic time-lapse data and execute them on existing data at the studied field. In the, first step geometrical conception of basal and monitoring data should be equalized. This section has been implemented using a new methodology, developed in this paper and is called “similarity table”. Then, data will be analyzed with spectra point of view and by executing shaping filters and by using cross equalization approach, basal and monitor seismic information will be closer as far as possible. Finally, analyzes were performed to validate the obtained results and evaluate the quality of time -lapse seismic analyzes.     

The effect of NaCl and HPAM solution concentration on HPAM gel structure degradation by ultrasonic waves

The present study evaluated the impact of ultrasonic waves on the degradation of partially hydrolyzed polyacrylamide (HPAM) gel structures, focusing on the effects of sonication time, NaCl concentration, and HPAM solution concentration. Results showed that both sonication time and salinity levels play a crucial role in the degradation of HPAM gel, with an increase in sonication time leading to a decrease in the remaining gel and the presence of NaCl in the solution decreasing the residual time required for degradation. The results also revealed that higher levels of salinity expedite the degradation of the gel. In addition, the study discovered that a rise in polymer solution concentration usually results in a reduction in gel degradation. The research suggests there might be an ideal combination of polymer solution and NaCl concentration for achieving the greatest decrease in the degradation rate. For 2-min sonication, as the salinity of the HPAM solution, with a concentration of up to 5000 ppm, increases, the accumulated energy remains relatively constant. However, when the polymer solution concentration is increased, the accumulated energy becomes more sensitive to changes in salinity. The results of this study provide valuable insight into the interplay between polymer solution concentration, salt concentration, and the energy required for gel degradation, which can be applied in various fields including the oil and gas industry, petroleum processing, and environmental remediation.     

A Simple Investigation of the Thermal Effusivity of Silver Nanofluid Using Photopyroelectric Technique

We investigated the thermal effusivity of silver nanofluids using a microwave technique. During microwave irradiation, silver nanoparticles with a narrow particle size distribution were formed in water and in ethylene glycol, with a polyvinylpyrrolidone stabilizer. We designed and used a front-photopyroelectric technique that employed a metalized polyvinylidene difluoride (PVDF) pyroelectric sensor, with a thermally thick sensor and sample. Using this technique, we calculated the thermal effusivity of the silver nanofluids at a given frequency using the combination of the signal’s normalized amplitude–phase. The thermal effusivity of the nanofluids increased with the number of microwave irradiation cycles, which increased the nanoparticle concentration in the base fluids. A comparison with reported values illustrates the high accuracy obtained from the results of thermal diffusivity, the thermal effusivity of the PVDF sensor, and the thermal effusivity of ethylene glycol as a base fluid (differing by only 1.7 %, 0.5 %, and 2.3 %, respectively). Our method can therefore be used to study nanofluids with varying nanoparticle properties, such as concentration, size, and shape.     

An efficient voltage to delay conversion method for DCVSL cells and its application in high speed all-digital time-based quantization

Translating the analog input voltage to delay of delay cells is a necessity for realizing digital time-based quantization. Usually, this conversion is done through additional elements, imposing extra power and area. This paper proposes a voltage to delay conversion method for cross-coupled differential cascode voltage switch logic (DCVSL) cells, without adding any extra elements to their basic structures. Cross-coupled delay cells are superior to conventional CMOS inverters in terms of lower power consumption, propagation delay, and area. However, controlling their delay is a demanding task due to their asynchronous charging and discharging. The key features of the proposed method are (a) controlling the delay of DCVSL cells just by see-saw changing of PMOS transistors source voltages; (b) reducing the propagation delays of DCVSL cells by simultaneously accelerating the charging and discharging processes; (c) reducing the power consumption by decreasing both the switching time and short-circuit current; (d) employing the proposed voltage to delay conversion method to develop a low power, small area, all-digital time-based analog to digital converter (ADC). The proposed 4-bit ADC, implemented in TSMC 65-nm CMOS technology, consumes 0.37 mW at conversion speed of 2 GHz with SNDR 20.9 dB and SFDR 30.2 dB, and occupies an active area of 0.0029 mm².     

Synthesis and characterization of new optically active poly(amide‐imide‐urethane) thermoplastic elastomers,derived from 4,4′‐(hexafluoroisopropylidene)‐N,N′‐bis(phthaloyl‐L‐leucine‐p‐aminobenzoic acid) and PEG‐MDI

A new class of optically active poly(amide‐imide‐urethane) was synthesized via two‐step reactions. In the first step, 4,4′‐methylene‐bis(4‐phenylisocyanate) (MDI) reacts with several poly(ethylene glycols) (PEGs) such as PEG‐400, PEG‐600, PEG‐2000, PEG‐4000, and PEG‐6000 to produce the soft segment parts. On the other hand, 4,4′‐(hexafluoroisopropylidene)‐N,N′‐bis(phthaloyl‐L ‐leucine‐p‐amidobenzoic acid) (2) was prepared from the reaction of 4,4′‐(hexafluoroisopropylidene)‐N,N′‐bis(phthaloyl‐L ‐leucine) diacid chloride with p‐aminobenzoic acid to produce hard segment part. The chain extension of the above soft segment with the amide‐imide 2 is the second step to give a homologue series of poly(amide‐imide‐urethanes). The resulting polymers with moderate inherent viscosity of 0.29–1.38 dL/g are optically active and thermally stable. All of the above polymers were fully characterized by IR spectroscopy, elemental analyses, and specific rotation. Some structural characterization and physical properties of this new optically active poly(amide‐imide‐urethanes) are reported. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2288–2294, 2004     

Investigation of spatial variability of SPT data in Mashhad City (NE Iran) using a geostatistical approach

Bulletin of Engineering Geology and the Environment - Precisely investigating subsurface conditions is a major concern for both geotechnical and geological engineers. In recent years, growing...     

Optimization of encapsulation of maltogenic amylase into a mixture of maltodextrin and beeswax and its application in gluten-free bread

In this work maltogenic amylase (MAase) was encapsulated into the mixture of maltodexrin and beeswax (BW) for retarding staling of gluten-free bread. The effects of maltogenic amylase (MAase) concentration (8.2, 45, and 82 mg/ml), maltodextrin with dextrose equivalent (DE) 4–7 (MD) (1, 2.5, and 4%) and, BW (1, 2.5, and 4%) on the encapsulation efficiency (EE) of encapsulated enzyme were optimized using RSM. The optimized formulation was MAase with 8.2 mg/ml, MD 4% and BW 1%, leading to the highest EE (79.35%), thus chosen for subsequent experiments. The prepared particles were 1,190.50 nm with PDI of 0.336 and zeta potential of −8.30 mV. Surface morphologies of produced particles were almost spherical with layered appearance. Batter with this formulation led to higher cross over point in frequency sweep than free enzyme-loaded batter. Lower weight loss, higher volume index, darker crust color, whiter crumb color, more aerated microstructure, less hardness in crumb, and higher sensorial acceptability on the first day and during storage period in the breads containing encapsulated MAase was observed.     

Robust PEDOT:PSS Wet‐Spun Fibers for Thermoelectric Textiles

To realize thermoelectric textiles that can convert body heat to electricity, fibers with excellent mechanical and thermoelectric properties are needed. Although poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is among the most promising organic thermoelectric materials, reports that explore its use for thermoelectric fibers are all but absent. Herein, the mechanical and thermoelectric properties of wet‐spun PEDOT:PSS fibers are reported, and their use in energy‐harvesting textiles is discussed. Wet‐spinning into sulfuric acid results in water‐stable semicrystalline fibers with a Young's modulus of up to 1.9 GPa, an electrical conductivity of 830 S cm^?1, and a thermoelectric power factor of 30 μV m^?1 K^?2. Stretching beyond the yield point as well as repeated tensile deformation and bending leave the electrical properties of these fibers almost unaffected. The mechanical robustness/durability and excellent underwater stability of semicrystalline PEDOT:PSS fibers, combined with a promising thermoelectric performance, opens up their use in practical energy‐harvesting textiles, as illustrated by an embroidered thermoelectric fabric module.