Robustness and stability measures for scheduling: single-machine environment

This paper addresses the issue of finding robust and stable schedules with respect to random disruptions. Specifically, two surrogate measures for robustness and stability are developed. The proposed surrogate measures, which consider both busy and repair time distributions, are embedded in a tabu-search-based scheduling algorithm, which generates schedules in a single-machine environment subject to machine breakdowns. The performance of the proposed scheduling algorithm and the surrogate measures are tested under a wide range of experimental conditions. The results indicate that one of the proposed surrogate measures performs better than existing methods for the total tardiness and total flowtime criteria in a periodic scheduling environment. A comprehensive bibliography is also presented.     

Oxidative Stability and In Vitro Release Properties of Encapsulated Wheat Germ Oil in Saccharomyces cerevisiae Cell-Based Microcapsules

This research aims to evaluate the feasibility of Saccharomyces cerevisiae cell-based microencapsulation for wheat germ oil (WGO) based on oxidative stability and in vitro release properties. Microencapsulation of samples is achieved by freeze-drying WGO-in water emulsions containing alive, non-plasmolyzed, and plasmolyzed yeast cells. The encapsulation efficiency (EE), loading capacity (LC), release characteristics, and oxidative stability of WGO are determined before and after microencapsulation. The amount of β-carotene in the digesta is used to evaluate the release properties. Plasmolyzed yeast cells yield the highest EE (43.1%) and LC (216.5 g kg⁻¹). In cases where alive and non-plasmolyzed yeast cells were used as an encapsulant, a higher release rate was obtained in esophagus-stomach conditions, while higher digestion took place mainly in the duodenum and ileum with plasmolyzed cells. Encapsulation of WGO in plasmolyzed yeast cells provide the lowest peroxide and p-anisidine values and the highest oxidative protection during the accelerated oxidation test at 60 °C for 24 days. This result is also confirmed by Rancimat induction time. Practical Applications: Removing the plasma content by plasmolysis changes the structure of the yeast cell membrane and improves the encapsulation ability and release properties. Encapsulation of WGO with plasmolyzed yeast cells provides superiority in oxidative stability compared to native WGO. The potential value of WGO as an ingredient in the preparation of functional foods could be achieved by yeast cell encapsulation.     

Plant‐based metallic nanoparticles as potential theranostics agents: bioinspired tool for imaging and treatment

Theranostic approach provides us a platform where diagnosis and treatment can be carried out simultaneously. Biosynthesis of theranostic‐capable nanoparticles (NPs) can be carried out by phytoconstituents present inside the plants that can act as capping as well as stabilising agents by offering several advantages over chemical and physical methods. This article highlights the theranostic role of NPs with emphasis on potential of plants to produce these NPs through ecofriendly approach that is called ‘Green synthesis’. Biosynthesis, advantages, and disadvantages of plant‐based theronostics have been discussed for better understanding. Moreover, this article has highlighted the approaches required to optimise the plant‐mediated synthesis of NPs and to avoid the toxicity of these agents. Anticipating all of the challenges, the authors expect biogenic NPs can appear as potential diagnostic and therapeutic agents in near future.Inspec keywords: nanofabrication, nanomedicine, nanoparticles, biomedical imaging, patient treatmentOther keywords: bioinspired tool, biosynthesis, theranostic‐capable nanoparticles, Green synthesis, plant‐based theronostics, plant‐mediated synthesis, potential diagnostic agents, therapeutic agents, theranostics agents, plant‐based metallic nanoparticles     

Additively manufactured trapezoidal grooves for wideband and high gain Ku‐band antenna

Grooves around aperture antennas are known to be instrumental in obtaining directive antenna patterns. The shapes of the grooves are often restricted to rectangular or triangular due to manufacturing difficulties in traditional metal machining, and because of this reason, the effect of groove shape on antenna performance is often overlooked. The aim of this study is to analyze different groove shapes with the help of additive manufacturing. Waveguide slot fed, dual cavity aperture antenna with grooves is designed and the effect of groove shapes on antenna performance is studied at Ku band. Two antennas with and without grooves are built using 3D printing technology. Measured antenna performance reveals 5 GHz bandwidth covering 10 to 15 GHz for Ku‐band satellite communications and part of the X‐band applications. Proposed antenna achieves 13.25 dBi peak gain at 14 GHz and the gain is better than 11.25 dBi over the entire Ku‐band uplink and downlink frequency bands.     

Evaluation of temperature changes in the pulp chamber during polymerization of pulp capping materials

Polymerization of resin-based materials leads to temperature rise, caused by the exothermic nature of the reaction and energy absorbed during polymerization. This temperature rise is influenced by intensity of light, composition of resins, and type of light source. This study evaluated thermal insulating properties of four photo-polymerizing pulp-capping agents in primary and permanent teeth. Roots of 80 primary and permanent teeth were removed. Class-I cavities were prepared on the occlusal surfaces of teeth. Materials used were TheraCal LC, Biner LC, ACTIVA BioACTIVE, and Calciplus LC and light sources were 3 M-Elipar and VALO LED. Temperature rise was measured using a J-type thermocouple. Data were statistically evaluated using ANOVA and Tukey`s tests (p = 0.05). VALO LED exhibited significantly lower temperature rise in all groups and temperature rise in primary teeth was significantly higher with all experimental materials (p < 0.05). The highest temperature change was observed in the Biner LC group (3.82 ± 0.58) and the lowest change in the Activa-BioACTIVE group (1.78 ± 0.34). The VALO LED light source caused a significantly lower increase in pulpal temperature compared with the 3 M-Elipar source. All tested materials and light sources maintained pulpal temperature under safe limits, with temperature increases not exceeding 5.5 °C.     

Strawberry drying: Development of a closed-cycle modified atmosphere drying system for food products and the performance evaluation of a case study

In the present study, a closed-cycle modified atmosphere drying (CC-MAD) system was developed as an alternative drying technique to facilitate drying processes for agricultural commodities appropriate to highly humid and sunny regions with a better quality. An absorption dehumidifying system was designed for working pseudo-continuously with the most efficient absorbent in terms of moisture absorption, desorption rate, and capacity. The system, assisted by a solar panel for absorbent regeneration, was tested, while its optimum working condition was determined by strawberry drying. This unique process was comparatively carried out using hot-air and freeze-drying techniques in terms of processing time and final product quality. Strawberry slices (5?mm thickness) were dried successfully using CC-MAD. The optimum drying conditions of CC-MAD were determined as drying temperature of 60°C, drying air/gas velocity of 3?m/s and drying medium oxygen level of 9.47%. The loss of ascorbic acid was significantly reduced by CC-MAD technique. These losses were found to be 2.9, 6.9, 27.2, and 23.8% by freeze-drying, CC-MAD, hot-air drying, and hot-air drying combined with CC-MAD, respectively. The total monomeric anthocyanins loss was also significantly reduced by the CC-MAD technique (20.3%), in a similar way to that of freeze-drying (18.1%) in comparison with hot-air drying (40.4%). In addition, CC-MAD (12,446?kJ/kg fresh product at 4?h drying time) is three times more advantageous in terms of energy cost compared with freeze-drying (30492.8?kJ/kg fresh product at 24?h drying time) and six times faster in terms of drying time. This new drying system can be used as an alternative to freeze-drying in the drying of foods, especially in products sensitive to oxidation.     

Electric and Dielectric Properties of Cr-Ga Substituted BaM Hexaferrites for High-Frequency Applications

Single-phase Cr-Ga-substituted BaM hexaferrites with chemical formula BaCr _x Ga _x Fe_12?2x O₁₉ (x = 0.0, 0.1, 0.2, 0.3, and 0.4) are synthesized by means of a sol-gel autocombustion technique. Cold isostatic-pressing technique has been used to press the as-prepared powders into pellets. Room-temperature DC resistivity enhances with the substitution of Cr-Ga contents. The temperature dependence of the DC resistivity shows the semiconducting nature. The dielectric constant and dielectric tangent loss decrease, while AC conductivity increases with the increasing applied field frequency in the range of 1 MHz-3 GHz consistent with Koop’s theory and Maxwell-Wagner’s bi-layer model. The magnetic loss enhances, while the reflection coefficient decreases with the increase of frequency as well as with the increase of Cr-Ga contents. Owing to improved properties, these materials are potential candidates for high-frequency applications in GHz range.     

Effects of Heat-Treatment Time on the Structural, Dielectric, Electrical, and Magnetic Properties of BaM Hexaferrite

M-type hexaferrite (BaFe₁₂O₁₉) powders have been synthesized by means of the sol-gel autocombustion technique and is heat treated at 1000 °C for different times (t = 1, 2, 3, and 4 h). Differential scanning calorimetry and thermogravimetric analyses are carried out to observe the weight loss and transformation of different phases during heat treatment. X-Ray diffraction patterns of the sample heat treated for 4 h confirms the formation of single phase M-type hexaferrite. The dielectric parameters and ac conductivity (σ_ac) are measured in the high frequency range 1 MHz-3 GHz. The dielectric properties and ac conductivity are based on the space charge polarization according to the Maxwell-Wagner two-layer model and the Koop’s phenomenological theory. The dielectric constant (ε′) and dielectric loss (tan δ) decrease, while ac conductivity enhances with the increase of frequency. The room temperature DC electrical resistivity of the sample heat treated for 2 h enhances up to 2.93 × 10⁹ (Ω-cm) and attributed to the migration of Fe²⁺ ions to the neighboring tetrahedral sites and lowering the Fe³⁺ contents on the octahedral sites. The temperature-dependent DC resistivity of samples shows a normal semiconducting behavior. The saturation magnetization, magnetic moment, and coercivity of the samples are observed to enhance with the increase of heat-treatment time. Owing to these qualities, the synthesized materials may be considered useful for high frequency applications, recording media, and permanent magnets.     

Determination and calculation of gamma and neutron shielding characteristics of concretes containing different hematite proportions

To obtain gamma and neutron attenuation characteristics experimental measurements and Monte Carlo simulations were carried out for hematite-loaded concrete samples. Also, the mechanical strength of samples was studied. However, the results for neutron attenuation reveal that there is no effect of hematite inclusion in concrete with respect to the neutron absorption capability. Gamma-ray attenuation capability and the mechanical strength both increased with increasing the hematite percent.