Rheological and thermal properties of an enteral nutrition formula for nutritional support patients using a combined mixture of gelatin and maltodextrin

Enteral nutrition is a type of nutritional support that provides the necessary sources of energy and protein for patients who suffer from dysphagia, chronic disease, and loss of appetite. In this study, a gelatin-maltodextrin binary biopolymer system has been incorporated into a semi-solid formula. The I-optimal combination design approach was used to create 19 formulations, and the dynamic rheological properties, dynamic laser scattering, and zeta potential responses were evaluated over 30 days of storage at 5°C. Solid viscoelastic behavior has been approved since G′ > G″ in the frequency sweep test with no cross-over point. Maltodextrin may interfere within the gelatin network, and increasing the maltodextrin to gelatin (from 0.14 to 1) may lead to a wider linear viscoelastic (LVE) strain range (2.16%), a lower storage modulus at LVE (52%), a lower yield stress (46%), and a lower glass transition temperature (34%). The presence of maltodextrin may reduce the temperature of the sol-to-solid transformation by 48% and enhance its flexibility. In contrast, increasing the gelatin-to-maltodextrin ratio following melting at 37°C led to an increase in the cumulant mean and polydispersity index, indicating a relatively unstable system. The range of zeta potential values between −4.4 and 1.7 mV confirmed a tendency toward coagulation. Microscopic images revealed instability because of irregular or compact chains formed in the gelatin matrix by using higher amounts of maltodextrin. Finally, the best formula had the best rheological stability and was suitable for tube-feeding patients, with a gelatin-to-maltodextrin ratio of 4.35:3.64% w/w on day 17.4.     

Extraction of caffeine and catechins using microwave-assisted and ultrasonic extraction from green tea leaves: an optimization study by the IV-optimal design

In this research, optimal conditions for extraction of caffeine and polyphenols were established from Iranian green tea leaves. In the first step, caffeine was extracted with efficacy about 86% versed to 4.5% of EGC + EGCG. The EGCG + EGC was extracted from partially decaffeinated green tea leaves through microwave-assisted extraction (MAE) and ultrasound-assisted extraction (USE) with efficiency levels of 95 and 85%, respectively. The best results for the MAE process were obtained with 7.8 min and three number of extraction cycles and for the USE process were as followed: time 57 min, temperature 65 °C, and the number of extraction cycles 3. The total phenol content values at the best conditions of MAE and the USE processes were 125 ± 5 and 96 ± 6 mg gallic acid/g DW. The 50% inhibition (IC₅₀) on 1,1-diphenyl-2-picrylhydrazyl (DPPH) were 56 and 66 mg/g of phenol for the MAE and USE processes.     

Improving the functional properties of fish gelatin by conjugation with the water-soluble fraction of bitter almond gum

Food Science and Biotechnology - Maillard-based conjugation may be a useful way of improving the functional properties of food biopolymers. In this study, covalent attachment of fish gelatin (FG)...     

A Multi-Criteria Group Decision Making Methodology Using Interval Type-2 Fuzzy Sets: Application to Water Resources Management

In this paper, a new fuzzy group decision-making methodology which determines and incorporates negotiation powers of decision makers is developed. The proposed method is based on a combination of interval type-2 fuzzy sets and a multi-criteria decision making (MCDM) model, namely TOPSIS. To examine the applicability of the proposed methodology, it is used for finding the best scenario of allocating water and reclaimed wastewater to domestic, agricultural, and industrial water sectors and restoring groundwater quantity and quality in the Varamin region located in Tehran metropolitan area in Iran. The results show that the selected scenario leads to an acceptable groundwater conservation level during a long-term planning horizon. Although the capital cost of this scenario is high, which leads to groundwater restoration during the 34-year planning horizon, it is determined as the best allocation scenario. This scenario also entails the second least pumping cost, due to less water allocation from the groundwater. To evaluate the results of the proposed methodology, they are compared with those obtained using some well-known interval type-2 decision-making approaches including arithmetic-based, TOPSIS-based, and likelihood-based comparison methods. The Spearman correlation coefficient shows that the obtained results generally concur with those of the other methods. It is also concluded that the proposed methodology gives more reasonable results by calculating and considering the negotiation powers of decision makers in an extended TOPSIS-based group decision-making model.

     

Printed dual-band base station antenna for GSM/DCS/PCS/UMTS and LTE applications with dual polarization

A new design of the dual-band and dual-polarized base station antennas for supporting the mobile communication systems operating at the GSM/DCS/PCS/UMTS and LTE frequency bands is presented. A wide input impedance matching bandwidth is achieved due to a trident-shaped feeding technique. Two printed dipoles, which are located perpendicularly to each other and fed by stepped-microstrip lines, establish the proposed antenna. In addition, by locating a low-profile cavity-backed structure, as a metal reflector under the antenna, bidirectional radiations of the dipoles are switched to unidirectional radiations with an increase in the gain of the antenna. Measurement results indicate that the proposed antenna is suitable for base station applications at the operating frequencies of 800/900/1800/1900/2300 MHz. The isolation is better than 20 dB, and peak gains of 10.08 and 9.96 dBi are attained at port-1 and port-2, respectively. Furthermore, the HPBWs of the antenna in H-plane is more than 61° for each port. The overall dimension of the antenna is 168 × 168 mm², which is mounted upon a 222 × 222 mm² cavity-backed structure with a depth of 42 mm.     

Practical Implementation of Novel Robust Position Control Scheme for Synchronous Reluctance Motor

A variable structure robust position controller is presented for a three-phase synchronous reluctance motor. Linear control and variable structure control and pulse-width modulation generation are combined. These provide robust, fast, and accurate position control without the penalty of high chattering. Schemes, including conventional sliding-mode control and the proposed scheme, are tested under parameter variations, and sudden perturbations are applied to the system at a specific time, then compared. This scheme uses both advantages of traditional variable structure control methods and linear methods. The disadvantages of each method, such as chattering and parameter sensitivity, are minimized. Results demonstrate that the proposed technique preserves the classical linear position control merits, while both the steady-state and transient behavior are significantly improved in terms of robustness, accuracy, and low ripple. The results also prove that the position reference command is perfectly tracked in spite of motor parameter uncertainties and load torque disturbance in control of the system that uses the new schemes.     

PALS free volume study of dry and water saturated epoxies

Free volume cavity sizes and fractions of epoxy specimens were determined using positron annihilation lifetime spectroscopy (PALS). PALS data were obtained before and after specimen water equilibration. Specimens were bisphenol A epoxide (B) and/or glycol epoxide (G) cured with a polyamide. Free volume sites increased linearly and cavity sizes decreased linearly with epoxide B:G ratio. Glass transition temperature (T_g) increased with epoxide B:G ratio. Water molecules in wet epoxy B filled approximately six percent of the cavities. Epoxy G cavity size increased 11.4% after water equilibrium and was ascribed to cavity expansion. PALS results differed for commercial corrosion inhibitors in wet and dry mixtures of these epoxides. Zettlemoyer Center for Surface Studies, 7 Asa Dr., Bethlehem, PA 18015. MAHMOUD M. MADANI is with the Zettlemoyer Center for Surface Studies at Lehigh University. He received his B.S. Degree in Physics from Pars College, Tehran, Iran in 1975; his B.S. Honors in 1981, M.S. Degree in 1982, and his Ph.D. Degree in 1986 from Royal Holloway and Bedford New Colleges, University of London. Dr. Madani’s current research studies include the physical chemical characteristics of polymeric coatings and the reliability and characterization of microelectronic packaging materials using PALS, EIS, XPS, SEM, XRD, and MS. He has developed several computer codes for instrumentation interfaces and data analyses. Previously, he was a lecturer in Physics at the University of Bophutatswana, South Africa. Dr. Madani is author and co-author of more than 20 scientific publications. Dr. Madani is a member of the American Physics Society. ROY R. MIRON is a Visiting Research Scientist at the Zettlemoyer Center for Surface Studies at Lehigh University. He received his B.A. and his Ph.D. Degrees from Lehigh University and his M.S. from Middlebury College. Dr. Miron has a broad background in coatings technology. He is the holder of several patents and his publications have appeared inAnalytical Chemistry, Journal Applied Polymer Science, Plastics Paint and Rubber, Plant Engineering, Western Paint Review, and the Hydrocarbon Processing and Petroleum Refiner. He has held memberships in the American Chemical Society and Society of Plastics Engineers. Dr. Miron has presented papers to the Society of Plastics Industry, Society of Plastics Engineers, and the Liberty Bell Corrosion Course. RICHARD D. GRANATA is Lehigh University Senior Research Scientist and Director of the Corrosion Laboratory. He received B.S. and Ph.D. Degrees from The American University in Washington, D.C., studying electrochemistry with Robert Foley. As a Research Scientist at Carnegie-Mellon Institute of Research with Howard Gerhart, he worked on cathodic electrocoating formulations. Moving to Lehigh University, Dr. Granata joined Henry Leidheiser at the Zettlemoyer Center for Surface Studies and continued research in protective polymers and electrochemical corrosion. He has one patent and over 50 technical papers as the author or co-author. His research experience has been acquired in cooperative work on industry and government sponsored programs. He has acquired a broad perspective on corrosion science and technology through this experience with problems involving electrochemical corrosion mechanisms, surface modification by ion implantation, cathodic delamination mechanism, corrosion inhibition, food container life-predictions, corrosion mechanisms in electronics packaging, and protective mechanisms of polymer coatings. Dr. Granata is a member of the Philadelphia Society for Coatings Technology, ECS, National Association of Corrosion Engineers, American Society for Testing and Materials, Steel Structures Paint Council, and American Chemical Society.