A quantum mutation-based backtracking search algorithm

The exposition of any nature-inspired optimization technique relies firmly upon its executed organized framework. Since the regularly utilized backtracking search algorithm (BSA) is a fixed framework, it is not always appropriate for all difficulty levels of problems and, in this manner, probably does not search the entire search space proficiently. To address this limitation, we propose a modified BSA framework, called gQR-BSA, based on the quasi reflection-based initialization, quantum Gaussian mutations, adaptive parameter execution, and quasi-reflection-based jumping to change the coordinate structure of the BSA. In gQR-BSA, a quantum Gaussian mechanism was developed based on the best population information mechanism to boost the population distribution information. As population distribution data can represent characteristics of a function landscape, gQR-BSA has the ability to distinguish the methodology of the landscape in the quasi-reflection-based jumping. The updated automatically managed parameter control framework is also connected to the proposed algorithm. In every iteration, the quasi-reflection-based jumps aim to jump from local optima and are adaptively modified based on knowledge obtained from offspring to global optimum. Herein, the proposed gQR-BSA was utilized to solve three sets of well-known standards of functions, including unimodal, multimodal, and multimodal fixed dimensions, and to solve three well-known engineering optimization problems. The numerical and experimental results reveal that the algorithm can obtain highly efficient solutions to both benchmark and real-life optimization problems.

     

HSWOA: An ensemble of hunger games search and whale optimization algorithm for global optimization

The search for food stimulated by hunger is a common phenomenon in the animal world. Mimicking the concept, recently, an optimization algorithm Hunger Games Search (HGS) has been proposed for global optimization. On the other side, the Whale Optimization Algorithm (WOA) is a commonly utilized nature-inspired algorithm portrayed by a straightforward construction with easy parameters imitating the hunting behavior of humpback whales. However, due to minimum exploration of the search space, WOA has a high chance of trapping into local solutions, and more exploitation leads it towards premature convergence. The concept of hunger from HGS is merged with the food searching techniques of the whale to lessen the inherent drawbacks of WOA. Two weights of HGS are adaptively designed for every whale using the respective hunger level for balancing search strategies. Performance verification of the proposed hunger search-based whale optimization algorithm (HSWOA) is done by comparing it with 10 state-of-the-art algorithms, including three very recently developed algorithms on 30 classical benchmark functions. Comparison with some basic algorithms, recently modified algorithms, and WOA variants is performed using IEEE CEC 2019 function set. Statistical performance of the proposed algorithm is verified with Friedman's test, boxplot analysis, and Nemenyi multiple comparison test. The operating speed of the algorithm is determined and tested with complexity analysis and convergence analysis. Finally, seven real-world engineering problems are solved and compared with a list of metaheuristic algorithms. Numerical and statistical performance comparison with state-of-the-art algorithms confirms the efficacy of the newly designed algorithm.     

Physicochemical changes occurring during post-harvest hardening of trifoliate yam (Dioscorea dumetorum) tubers

Processing of Dioscorea dumetorum tubers into flour could be a means of adding a longer-term value to this tropical plant with a high nutritional potential but which presents a post-harvest hardening problem. This study was carried out in order to investigate the effect of storage under prevailing tropical ambient conditions (19–28 °C, RH 60–85%) for 56 days on the physicochemical characteristics of flours produced from hardened tubers. With the exception of bulk density, the results showed that all the physicochemical properties measured (water absorption capacity, oil absorption capacity, water solubility index, hydrophilic–lipophilic index, swelling capacity and least gelatinising concentration) were significantly influenced by tuber storage time (P<0.05). In general, the physicochemical indices increased with storage in at least two phases, from days 2 to 21 and from days 28 to 56. Since sprouting of most tubers was observed after 28 days of storage, the results suggest that post-harvest hardening and sprouting influence the above-mentioned indices of flours produced from D. dumetorum tubers.     

Technical note: Lineament detection on Mount Cameroon during the 1999 volcanic eruptions using Landsat ETM

A study of the active Mount Cameroon volcano, located south west along the Cameroon Volcanic Line, was carried out during the 1999 volcanic eruption, using Landsat Enhanced Thematic Mapper (ETM) imagery. It investigated geologic deformations expressed as faults, cracks and lineaments resulting from the eruption. Various image processing techniques were tested and compared in order to detect the most effective output. Principal Component Analysis was found to be useful to determine the extent of deformations caused during the 1999 volcanic eruptions. Landsat ETM revealed the formation of faults and lineaments with proximity to eruption vents. The interpretation obtained from satellite imagery was cross checked with field and ground truthing data. This paper identifies the dimensions and orientations of the newly formed geologic features.     

Nutritional value and antioxidant capacity of lunch meals consumed by elderly people of Sharpeville,South Africa

The main objective of this study was to determine the nutritional value and the total dietary antioxidant capacity (TDAC) of lunch meals consumed by elderly people attending a day-care centre in Sharpeville, South Africa. Meals were monitored and collected for a two-week period. The menus were analysed for water, ash, fat, protein, carbohydrates, polyphenols and antioxidant capacity. Eighteen food items, grouped in seven different menus, were identified. Energy provided by the menus covered 32% of the daily reference intakes for females and 25% for males, and the distribution of macronutrients in the menus was 10%, 34% and 56% for protein, fat and carbohydrates, respectively. This is close to the prescribed acceptable macronutrient distribution ranges of 10–35% protein, 20–35% fat and 45–65% carbohydrates. TDAC available from the menus was estimated at 332 μmol Trolox equivalents by DPPH (2,2′-diphenyl-1-picrylhydrazyl) and represented about 9% of the recommended daily allowance. Fruit, which represented only 2.8% of the amount of foods composing the menus, supplied 75.3% of TDAC, whilst contributions from vegetables and legumes were low. With 269 mg gallic acid equivalent in the menus, total phenolics appeared to be quantitatively the main dietary antioxidant, and were significantly correlated (r = 0.443 and p = 0.007) with antioxidant capacity. Fruit portions of the meals served by the day-care centre to the elderly of Sharpeville, need to be increased and diversified in order to reinforce their intake of antioxidants and thus reduce the incidence of non-communicable diseases.     

A metasurface‐based broadband quasi nondispersive cross polarization converter for far infrared region

A broadband nondispersive cross polarization converter (CPC) structure using metasurface for far infrared region has been proposed in this article. The structure is transmittive in nature, which converts a linearly polarized incident wave to its mutually orthogonal linearly polarized wave over a band of frequency ranging from 10.25 to 22.7 THz maintaining a high polarization conversion ratio (PCR) of more than 0.95. The fractional bandwidth of 75.6% corresponding to the center frequency of PCR bandwidth having more than 0.9 PCR value has been realized. The structure is also studied for oblique incidences where it shows wide band polarization conversion up to 45° for both TE and TM polarized oblique incident waves. The electric field distributions at the top and bottom surfaces of the structure close to the center frequency of polarization conversion bandwidth indicate the orthogonal rotation of incident linearly polarized wave at the frequency of interest. For the given set of media interface a separate study on polarization conversion through Brewster angle concept has been carried out simultaneously. The structure exhibits high PCR by maintaining the compactness in thickness (~ λ/5) as well as periodicity (~ λ/3) compared to the existing reported ones.     

Very Important Publication: Hypoiodite‐Catalyzed Regioselective Oxidation of Alkenes: An Expeditious Access to Aldehydes in Aqueous Micellar Media

A highly anti‐Markovnikov selective oxidation of alkenes based on in situ generated hypoiodite catalysis in aqueous micellar media under mild conditions has been described. This novel catalytic system realizes an efficient synthesis of aldehydes from alkenes in an economically viable and environmentally safe fashion. The preliminary mechanistic studies suggest that the reaction proceeds via tandem iodofunctionalization/1,2‐aryl or alkyl migration. The scope and limitations of this tandem process are demonstrated with various mono‐ and disubstituted (terminal and internal) olefins.

     

MPBOA - A novel hybrid butterfly optimization algorithm with symbiosis organisms search for global optimization and image segmentation

The conventional Butterfly Optimization Algorithm (BOA) does not appropriately balance the exploration and exploitation characteristics of an algorithm to solve present-day challenging optimization problems. For the same, in this paper, a novel hybrid BOA (MPBOA, in short) is suggested, where the BOA is combined with mutualism and parasitism phases of the Symbiosis Organisms Search (SOS) algorithm to enhance the search behaviour (both global and local) of BOA. The mutualism phase is applied with the global phase of BOA, and the parasitism phase is added with the local phase of BOA to ensure a better trade-off between the global and local search of the proposed algorithm. A suit of twenty-five benchmark functions is employed to investigate its performance with several other state-of-the-art algorithms available in the literature. Also, to check its performance statistically, the Friedman rank test and t-test are carried out. The consistency of the proposed algorithm is tested with a boxplot diagram. Also, four real-world problems are solved to check the efficiency of the algorithm in solving industrial problems. Finally, the proposed MPBOA is utilized to obtain the optimal threshold in the multilevel thresholding problem of the segmentation of individual images. From the obtained results, it is found that the overall performance of the newly introduced MPBOA is satisfactory in terms of its search behaviour and convergence time to obtain global optima.

     

Probing Cell Deformability via Acoustically Actuated Bubbles

An acoustically actuated, bubble‐based technique is developed to investigate the deformability of cells suspended in microfluidic devices. A microsized bubble is generated by an optothermal effect near the targeted cells, which are suspended in a microfluidic chamber. Subsequently, acoustic actuation is employed to create localized acoustic streaming. In turn, the streaming flow results in hydrodynamic forces that deform the cells in situ. The deformability of the cells is indicative of their mechanical properties. The method in this study measures mechanical biomarkers from multiple cells in a single experiment, and it can be conveniently integrated with other bioanalysis and drug‐screening platforms. Using this technique, the mean deformability of tens of HeLa, HEK, and HUVEC cells is measured to distinguish their mechanical properties. HeLa cells are deformed upon treatment with Cytochalasin. The technique also reveals the deformability of each subpopulation in a mixed, heterogeneous cell sample by the use of both fluorescent markers and mechanical biomarkers. The technique in this study, apart from being relevant to cell biology, will also enable biophysical cellular diagnosis.