Mixed Route Research Articles

A note on a mixed routing and scheduling problem on a grid graph

We consider a particular case of the Fleet Quickest Routing Problem (FQRP) on a grid graph of m × n nodes that are placed in m levels and n columns. Starting nodes are placed at the first (bottom) level, and nodes of arrival are placed at the mth level. A feasible solution of FQRP consists in n Manhattan paths, one for each vehicle, such that capacity constraints are respected. We establish m*, i.e. the number of levels that ensures the existence of a solution to FQRP in any possible permutation of n destinations. In particular, m* is the minimum number of levels sufficient to solve any instance of FQRP involving n vehicles, when they move in the ways that the literature has until now assumed. Existing algorithms give solutions that require, for some values of n, more levels than m*. For this reason, we provide algorithm CaR, which gives a solution in a graph m* × n, as a minor contribution.

Characterization of D-lactic acid, spore-forming bacteria and Terrilactibacillus laevilacticus SK5-6 as potential industrial strains

In this study, we screened and isolated D-lactic acid-producing bacteria from soil and tree barks collected in Thailand. Among the isolates obtained, Terrilactibacillus laevilacticus SK5-6 exhibited good D-lactate production in the primary screening fermentation (99.27 g/L final lactate titer with 0.90 g/g yield, 1.38 g/L⋅h, and 99.00% D-enantiomer equivalent). Terrilactibacillus laevilacticus SK5-6 is a Gram-positive, endospore-forming, homofermentative D-lactate producer that can ferment a wide range of sugars to produce D-lactate. Unlike the typical D-lactate producers, such as catalase-negative Sporolactobacillus sp., T. laevilacticus SK5-6 possesses catalase activity; therefore, a two-phase fermentation was employed for D-lactate production. During an aerobic preculture stage, a high-density cell mass was rapidly obtained due to aerobic respiration. When transferred to the fermentation stage at the correct physiological stage (inoculum age) and proper concentration of cell mass (inoculum size), T. laevilacticus rapidly converted glucose into D-lactate under anaerobic conditions, resulting in a high final lactate titer (102.22 g/L), high yield (0.84 g/g), and high productivity (2.13 g/L⋅h). When the process conditions were shifted from an aerobic to an anaerobic environment, unlike other lactate-producing bacteria, the mixed acid fermentation route was not activated in the culture of T. laevilacticus SK5-6 during the fermentation stage when some trace oxygen still remained. Our study demonstrates the excellent characteristics of this isolate for D-lactate production; in particular, a high product yield was obtained without byproduct formation. Based on these key characteristics of T. laevilacticus SK5-6, we suggest that this isolate is a novel D-lactate producer for use in industrial fermentation.

An advanced traveler navigation system adapted to route choice preferences of the individual users

Abstract The majority of existing navigation systems only account for a single aspect of the route choice, like travel time or distance, in finding the optimal route for the trips in the network. In this research, we first identify a range of diverse factors that travelers take into account in their route choice decision in the network. A stated preference survey is conducted to show the heterogeneity in the preferences of users and its dependence to the purpose of the trips over the weekdays and weekends. Interestingly, results of the survey show that road safety is the most influential factor in the route choice decision of the average participants over weekends, exceeding even the travel time, and participants give more importance to the scenic quality of the routes for their weekend trips in comparison to their weekday trips. The results of the second part of the survey also indicate that in 27% of the cases participants choose routes other than the ones suggested by navigation systems, and 33% of the times that they take the suggested routes, they modify these routes according to their own preferences. The partial inability of existing navigation systems to suggest the routes that match the preferences of users can be attributed to ignoring (1) the diversity in influential factors and (2) the heterogeneity in preferences of the users by these systems. We propose a dynamic mixed logit route choice model to include the effects of information and learning to estimate parameters of a multivariable utility function for individual users based on their own historical route choice data over time. Finally, we present the concept of a smart navigation system that can gather the required information from real-time and online sources to suggest the routes that best match the users’ own preferences.

Social-ecological innovation in remote mountain areas: Adaptive responses of forest-dependent communities to the challenges of a changing world

To better understand how constantly changing human-environment interactions could be better organized to respond to current challenges, we examined the Ukrainian Carpathians as an example case of complex forest social-ecological systems (FSES). We did it by interviewing diverse and relevant local stakeholder (N=450). In particular, we strived to: i) outline how people and nature are linked and interact in coupled FSES; ii) examine the preferences of stakeholders on the forests and associated ecosystem services (ES); iii) map key drivers threatening well-being of FSES and iv) identify potential responses to address the challenges at a local scale. To answer these questions we followed a mixed method route by integrating qualitative (participatory) and quantitative data collection and analyses, with further application of a Driving Force-Pressure-State-Impact-Response (DPSIR) framework in combination with the ES approach in order to assess benefits, threats to these benefits, and responses regarding the studied FSES. We found that the key benefit from FSES is timber and non-wood forest products (like berries and mushrooms), but also various regulating services were ranked highly by respondents. To explore social-ecological innovation, with potential responses of forest-dependent communities to challenges they face, we employed a commonly used assumption that governance must fit to the particular characteristics of FSES in order to enable sustainability. For the particular case of the Ukrainian Carpathians, we identified and discussed the following five nonconformities or “misfits” threatening sustainability: 1) Spatial misfit in legislation; 2) Poor contextualization; 3) Trap of the single ES; 4) Participatory misfit; and 5) Robbing the commons. By conceptualizing those key threats, we proposed responses for sustainability. The findings contributed to an advanced understanding of complex FSES, their key challenges and potential solutions in order to secure well-being of people and nature in coupled social-ecological systems, in the conditions of a changing world.

Structural characterization of layered Na0.5Co0.5Mn0.5O2 material as a promising cathode for sodium-ion batteries

Layered Na0.5Co0.5Mn0.5O2 material is synthesized through a facile mixed hydroxy-carbonate route using (Co0.5Mn0.5)2(OH)2CO3 precursor and well characterized as a hexagonal layered structure under P63/mmc space group. The lattice parameters and unit cell volume (a = 2.8363 Å, c = 11.3152 Å and V = 78.83 Å3) are calculated by Rietveld refinement analysis. A flaky-bundle morphology is obtained to the layered Na0.5Co0.5Mn0.5O2 material with the hexagonal flake size ∼30 nm. Advanced transmission electron microscopic images are revealed the local structure of the layered Na0.5Co0.5Mn0.5O2 material with contrasting bright dots and faint dark dots corresponding to the Co/Mn and Na atoms. Two oxidation and reduction peaks are occurred in a cyclic voltammetric analysis corresponding to Co3+/Co4+ and Mn3+/Mn4+ redox processes. These reversible processes are attributed to the intercalation/de-intercalation of Na+ ions into the host structure of layered Na0.5Co0.5Mn0.5O2 material. Accordingly, the sodium cell is delivered the initial charge-discharge capacity 53/144 mAh g−1 at 0.5 C, which cycling studies are extended to rate capability test at 1 C, 3 C and 5C. Eventually, the Na-ion full-cell is yielded cathode charge-discharge capacity 55/52 mAh g−1 at 0.212 mA and exhibited as a high voltage cathode for Na-ion batteries.

Node, Edge, Arc Routing and Turn Penalties: Multiple Problems—One Neighborhood Extension

This article explores a structural neighborhood decomposition for arc routing problems, in which the decisions about traversal orientations during services are made optimally as part of neighbor evaluation procedures. Using memory structures, bidirectional dynamic programming, and lower bounds, we show that a large neighborhood involving classical moves on the sequences of services along with optimal orientation decisions can be searched in amortized O(1) time per move evaluation instead of O(n) as in previous works. Because of its generality and now-reduced complexity, this approach can be efficiently applied to several variants of arc routing problems, extended into large neighborhoods such as ejection chains, and integrated into two classical metaheuristics. Our computational experiments lead to solutions of high quality on the main benchmark sets for the capacitated arc routing problem (CARP), the mixed capacitated general routing problem (MCGRP), the periodic CARP, the multidepot CARP, and the min-max k-vehicles windy rural postman problem, with a total of 1,528 instances. We also report sensitivity analyses for new MCGRP instances with turn penalties, which are uncommonly challenging yet critical for many practical applications. The e-companion is available at https://doi.org/10.1287/opre.2017.1595

Effects of AlN Nanoparticles on the Microstructure, Solderability, and Mechanical Properties of Sn-Ag-Cu Solder

The addition of nanosized AlN particles to Sn-3.0 wt pctAg-0.5 wt pctCu (SAC305) lead-free solder alloy has been investigated. The various weight fractions of AlN (0, 0.03, 0.12, 0.21, 0.60 wt pct) have been dispersed in SAC305 solder matrix by a mechanical mixing and melting route. The influences of AlN nanosized particles on the microstructure, mechanical properties, and solderability (e.g., spreadability and wettability) have been carried out. The structural and morphological features of the nanocomposite solder were characterized by scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and transmission electron microscope (TEM). The experimental results show that the best combination of solderability and mechanical properties is obtained at 0.21 wt pct AlN in the solder matrix. The reinforced composite solder with 0.21 wt pct AlN nanoparticles shows ≈25 pct improvement in ultimate tensile strength (UTS), and ≈4 pct increase in the spreadability. In addition, the results of microstructural analyses of composite solders indicate that the nanocomposite solder, especially reinforced with 0.21 wt pct of AlN nanoparticles, exhibits better microstructure and improved elongation percentage, compared with the monolithic SAC305 solder.

Application of a developed distributed hydrological model based on the mixed runoff generation model and 2D kinematic wave flow routing model for better flood forecasting

AbstractDue to the specific characteristics of semi‐arid regions, this paper aims to establish a Grid‐and‐Mixed‐runoff‐generation‐and‐two‐dimensional‐Kinematic‐wave‐based distributed hydrological model (GMKHM‐2D model) coupling a mixed runoff generation model and 2D overland flow routing model based on kinematic wave theory for flood simulation and forecasting with digital drainage networks. Taking into consideration the complex runoff generation in semi‐arid regions, a mixed runoff generation model combining saturation‐excess mechanism and infiltration‐excess mechanism is developed for grid‐based runoff generation and 2D implicit finite difference kinematic wave flow model is introduced for routing to solve depressions water storing for grid‐based overland flow routing in the GMKHM‐2D model. The GMKHM‐2D model, the GMKHM‐1D model with coupling the mixed runoff generation model and one‐dimension kinematic wave flow model, the Shanbei model and the Xin'anjiang model were employed to the upper Kongjiapo basin in Qin River, a tributary of the Yellow River, with an area of 1454 km2 for flood simulation. Results show that two grid‐based distributed hydrological models and the Shanbei model perform better in flood simulation and can be used for flood forecasting in semi‐arid basins. Comparing with GMKHM‐1D, the flood peak simulation accuracy of the GMKHM‐2D model is higher.

Silver‐loaded HDPE/clay nanocomposites with antibacterial property: A potential replacement for commodity polyethylene plastic

A silver intercalated clay based HDPE nanocomposite with excellent antibacterial activity has been reported for the first time. Antibacterial silver‐clay (Ag‐MMT) synthesized in laboratory was incorporated into HDPE to prepare antibacterial HDPE/Ag‐MMT nanocomposites. Silver has been chosen as it is a powerful antimicrobial agent with additional properties such as unique optical, electrical, and thermal characteristics. The nanocomposites were fabricated through melt mixing route in a twin‐screw extruder with varying Ag‐MMT concentrations. Transmission electron microscopy, scanning electron microscopy, differential scanning calorimetry, and X‐ray diffraction studies confirmed superior dispersion of clay platelets in HDPE. Dynamic oscillatory properties and mechanical characteristics of the nanocomposites were determined to observe the effect of Ag‐MMT on HDPE. Antimicrobial testing of these nanocomposites against Gram‐negative bacteria Escherichia coli O157:H7 and Gram‐positive bacteria Staphylococcus aureus showed excellent bioactivity (>99%) at 5 wt% Ag‐MMT. These antibacterial plastic materials have potential to replace neat HDPE products in niche areas where antimicrobial property would be highly desirable. POLYM. COMPOS., 39:E366–E377, 2018. © 2017 Society of Plastics Engineers

Effects of Metallic Nanoparticles on Interfacial Intermetallic Compounds in Tin-Based Solders for Microelectronic Packaging

Tin (Sn)-based solders have established themselves as the main alternative to the traditional lead (Pb)-based solders in many applications. However, the reliability of the Sn-based solders continues to be a concern. In order to make Sn-based solders microstructurally more stable and hence more reliable, researchers are showing great interest in investigating the effects of the incorporation of different nanoparticles into them. This paper gives an overview of the influence of metallic nanoparticles on the characteristics of interfacial intermetallic compounds (IMCs) in Sn-based solder joints on copper substrates during reflow and thermal aging. Nanocomposite solders were prepared by mechanically blending nanoparticles of nickel (Ni), cobalt (Co), zinc (Zn), molybdenum (Mo), manganese (Mn) and titanium (Ti) with Sn-3.8Ag-0.7Cu and Sn-3.5Ag solder pastes. The composite solders were then reflowed and their wetting characteristics and interfacial microstructural evolution were investigated. Through the paste mixing route, Ni, Co, Zn and Mo nanoparticles alter the morphology and thickness of the IMCs in beneficial ways for the performance of solder joints. The thickness of Cu3Sn IMC is decreased with the addition of Ni, Co and Zn nanoparticles. The thickness of total IMC layer is decreased with the addition of Zn and Mo nanoparticles in the solder. The metallic nanoparticles can be divided into two groups. Ni, Co, and Zn nanoparticles undergo reactive dissolution during solder reflow, causing in situ alloying and therefore offering an alternative route of alloy additions to solders. Mo nanoparticles remain intact during reflow and impart their influence as discrete particles. Mechanisms of interactions between different types of metallic nanoparticles and solder are discussed.

Electrochemical Behaviour and Phase Evolutions during Sodiation/Desodiation of Na2Ti3O7 nanoparticles, Synthesized Via Sol-Gel Route, Decorating Carbon Nanotubes

The emerging technology of sodium ion batteries has attracted a great deal of attention due to the abundant availability and cost efficiency of the concerned raw materials. The technology still needs improvements, primarily in terms of finding suitable anode material with superior Na-capacity, cyclic stability and also rate capability. This is mainly caused by graphitic carbon not being able to intercalate sodium, unlike in the case of lithium. Layered Na2Ti3O7, because of its low potential against Na/Na+and decent theoretical Na-capacity (~200 mAh/g), has emerged as a promising anode material among other Na-based intercalation compounds [1]. However, in addition to its poor rate capability owing to inherently low electronic conductivity in pristine form, its cyclic stability is also far from being satisfactory. Poor structural stability during sodiation/desodiation is one of the reasons for the same. Against this backdrop, the present work focuses on improving the overall electrochemical behaviour, not only by reducing size of the Na2Ti3O7 particles to nano-sized regime, but also by incorporating conducting reinforcements like multi-walled carbon nanotubes (MWCNTs). However, the challenges associated with synthesizing active materials having nanoscaled dimensions via facile and cost-effective wet-chemical synthesis routes, while at the same time achieving intimate contact with carbon nanotubes usually pose practical hindrances towards improving rate capability and cyclic stability of promising ceramic electrode materials. Developing MWCNTs-incorporated composite electrode slurry via the usual physical mixing route may not allow intimate contact; rather may lead to contamination. Growth of MWCNTs on electrode-active particles via vapour deposition is not a cost-effective and scalable process. These disadvantages have been overcome in our work by developing an innovative, but facile sol-gel based route, which helped in synthesizing Na2Ti3O7 nanoparticles with near-perfect control over stoichiometry and also in intimate contact with MWCNTs. In more precise terms, the sol-gel based route has been tuned for successfully developing Na2Ti3O7 nanoparticles with MWCNTs uniformly wrapped around them allowing intimate contact with the MWCNTs, as was clearly evident from the high-resolution TEM images. The results once again highlight the success of this route based on direct addition of MWCNTs into the ‘matrix’ sol, followed by rapid gelation and subsequent crystallization in presence of MWCNTs (for Na-ion battery electrode), as recently demonstrated also for LiFePO4-MWCNT electrodes (for Li-ion batteries) [2]. The specific Na-capacities, as recorded during galvanostatic cycling, were considerably higher upon incorporation of the MWCNTs, as compared to those with the active particles of the same size/composition, prepared using the same route, but sans MWCNTs. More importantly, the cyclic stability improved significantly in the presence of the MWCNTs. The differences were more notable at the higher current densities, signifying considerably improved rate capability. In more specific terms, for over a period of 100 discharge/charge cycles, the capacity retention for Na2Ti3O7/MWCNT was superior to that for Na2Ti3O7, sans MWCNTs, by a factor of ~16. Another important observation has been the significant reduction in voltage hysteresis in presence of the MWCNTs. In addition to increasing the overall electrical conductivity, the anchoring/buffering action provided by the MWCNTs against the high volume changes during phase transformation reactions, might possibly be some of the reasons for the higher capacity and improved cyclic stability in the case of MWCNTs-containing Na2Ti3O7 nanoparticles. The work, to be presented, also includes in-situ synchrotron X-Ray diffraction studies for obtaining better insights into some of the fundamental aspects concerning phase transformations during charge/discharge at such ultra-fine dimension, in the presence/absence of MWCNTs (in intimate contact) and also in the presence of impurity phases (as deliberately introduced). The results provide clarity on the sodiation/de-sodiation mechanisms and correlations between the electrochemical performances, phase assemblage and phase evolutions of Na2Ti3O7 and Na2Ti3O7/MWCNT anodes for Na-ion batteries. Keywords: Na2Ti3O7/MWCNT, Na-ion batteries, Cyclic stability, In-situ synchrotron X-Ray diffraction

A parameterized approximation algorithm for the mixed and windy capacitated arc routing problem: Theory and experiments

We prove that any polynomial‐time ‐approximation algorithm for the n‐vertex metric asymmetric Traveling Salesperson Problem yields a polynomial‐time ‐approximation algorithm for the mixed and windy Capacitated Arc Routing Problem, where is the number of weakly connected components in the subgraph induced by the positive‐demand arcs—a small number in many applications. In conjunction with known results, we obtain constant‐factor approximations for and ‐approximations in general. Experiments show that our algorithm, together with several heuristic enhancements, outperforms many previous polynomial‐time heuristics. Finally, since the solution quality achievable in polynomial time appears to mainly depend on C and since C = 1 in almost all benchmark instances, we propose the Ob benchmark set, simulating cities that are divided into several components by a river. © 2017 Wiley Periodicals, Inc. NETWORKS, Vol. 70(3), 262–278 2017

Insights into the Dual-Electrode Characteristics of Layered Na0.5Ni0.25Mn0.75O2 Materials for Sodium-Ion Batteries.

Sodium-ion batteries are now close to replacing lithium-ion batteries because they provide superior alternative energy storage solutions that are in great demand, particularly for large-scale applications. To that end, the present study is focused on the properties of a new type of dual-electrode material, Na0.5Ni0.25Mn0.75O2, synthesized using a mixed hydroxy-carbonate route. Cyclic voltammetry confirms that redox couples, at high and low voltage ranges, are facilitated by the unique features and properties of this dual-electrode, through sodium ion deintercalation/intercalation into the layered Na0.5Ni0.25Mn0.75O2 material. This material provides superior performance for Na-ion batteries, as evidenced by the fabricated sodium cell that yielded initial charge-discharge capacities of 125/218 mAh g-1 in the voltage range of 1.5-4.4 V at 0.5 C. At a low voltage range (1.5-2.6 V), the anode cell delivered discharge-charge capacities of 100/99 mAh g-1 with 99% capacity retention, which corresponds to highly reversible redox reaction of the Mn4+/3+ reduction and the Mn3+/4+ oxidation observed at 1.85 and 2.06 V, respectively. The symmetric Na-ion cell, fabricated using Na0.5Ni0.25Mn0.75O2, yielded initial charge-discharge capacities of 196/187 μAh at 107 μA. These results encourage the further development of new types of futuristic sodium-ion-battery-based energy storage systems.

Optimal design of autonomous vehicle zones in transportation networks

This paper advocates the need for infrastructure planning to adapt to and further promote the deployment of autonomous vehicle (AV) technology. It is envisioned that in the future government agencies will dedicate certain areas of road networks to AVs only to facilitate the formulation of vehicle platoons to improve throughput and hopefully improve the performance of the whole network. This paper aims to present a mathematical framework for the optimal design of AV zones in a general network. With the presence of AV zones, AVs may apply different routing principles outside of and within the AV zones. A novel network equilibrium model (we refer to it as the “mixed routing equilibrium model”) is thus firstly proposed to capture such mixed-routing behaviors. We then proceed to formulate a mixed-integer bi-level programming model to optimize the deployment plan of AV zones. Numerical examples are presented to demonstrate the performance of the proposed models.

The close–open mixed multi depot vehicle routing problem considering internal and external fleet of vehicles

Distribution of finished goods from depots to predetermined customers and collection of goods and wastes are practical and challengeable optimization and logistics problems; therefore, appropriate management of transportation system can help companies decrease their costs and consequently earn more benefits. Several kinds of vehicle routing problems (VRPs) have been studied in the literature. In this paper, we will combine multi-depot vehicle routing problem (MDVRP) and close–open mixed vehicle routing problem (COMVRP), assuming that the fleet of vehicles is heterogeneous. Also, in this problem, contractors are used to meet a part of customers’ requirements. The objective of the problem is to minimize the total cost of serving customers. To efficiently deal with the problem, a new mixed integer programming (MIP) model as well as a new hybrid metaheuristic is proposed. Moreover, analytic hierarchical process is utilized in hybridization of the genetic algorithm. The computational experiments are conducted to compare the results of HGA, GA and MIP solver, CPLEX.

나노에멀젼 형성에서의 혼합 경로와 온도의 영향

본 연구에서는 동일한 농도의 유동파라핀/ Span 80-Tween 80/ 정제수로 구성되는 조성물을 혼합 경로와 온도에 따라 형성되는 에멀젼 상태를 비교하였다. 3성분계도상에서 최종 조성에 이르는 혼합경로는 세 가지로 구성하였다. 혼합 경로에 따라서 제조된 에멀젼의 평균 입자크기는 큰 차이를 보였으며 제조 온도가 증가함에 따라서도 에멀젼의 입자크기가 감소하였다. 그러나 혼합 온도보다는 혼합 경로에 따른 영향이 더욱 컸다.

An Adaptive Iterated Local Search for the Mixed Capacitated General Routing Problem

We study the mixed capacitated general routing problem (MCGRP) in which a fleet of capacitated vehicles has to serve a set of requests by traversing a mixed weighted graph. The requests may be located on nodes, edges, and arcs. The problem has theoretical interest because it is a generalization of the capacitated vehicle routing problem (CVRP), the capacitated arc routing problem (CARP), and the general routing problem. It is also of great practical interest since it is often a more accurate model for real-world cases than its widely studied specializations, particularly for so-called street routing applications. Examples are urban waste collection, snow removal, and newspaper delivery. We propose a new iterated local search metaheuristic for the problem that also includes vital mechanisms from adaptive large neighborhood search combined with further intensification through local search. The method utilizes selected, tailored, and novel local search and large neighborhood search operators, as well as a new local search strategy. Computational experiments show that the proposed metaheuristic is highly effective on five published benchmarks for the MCGRP. The metaheuristic yields excellent results also on seven standard CARP data sets, and good results on four well-known CVRP benchmarks, including improvement of the best known upper bound for one instance.

"UJI POTENSIODINAMIK MATERIAL PELAPIS ANTI- KOROSI: Acrylic Paint-PANi/SiO2 "

Polyaniline (PANi) was succesfully prepared from Ammonium Peroxodisulfate (APS) and anyline using chemical oxidation method. Silica (SiO2) was synthesized from natural sands taken from Banjar. PANi/SiO2 composites were prepared using mechanical mixing route. The composites were prepared by variating the weight compositions of PANi:SiO2 of 2.5%, and 5% for SiO2. Furthermore, the coating process of Paint-PANi/SiO2 on SS304 stainless stell by spray coating technique. The characterization of anticorrosive behaviour of Paint-PANi/SiO2 was tested by potentiodynamics method. The obtained Tafel curve was then analyzed by means of ANOVA method. The best anticorrosive performance refered to the sample of Paint-PANi/(5%)SiO2, both of before and after exposure processes. The corrotion rate of before and after exposure processes were 0,00896000 mpy and 0,00024408, respectively. DOI: http://dx.doi.org/10.17977/um024v1i12016p025

A branch‐and‐cut‐and‐price algorithm for the mixed capacitated general routing problem

In this paper, we consider the Mixed Capacitated General Routing Problem which is a combination of the Capacitated Vehicle Routing Problem and the Capacitated Arc Routing Problem. The problem is also known as the Node, Edge, and Arc Routing Problem. We propose a Branch‐and‐Cut‐and‐Price algorithm for obtaining optimal solutions to the problem and present computational results based on a set of standard benchmark instances. © 2016 Wiley Periodicals, Inc. NETWORKS, Vol. 68(3), 161–184 2016

Hierarchical nanostructured 3D flowerlike BiOX particles with excellent visible-light photocatalytic activity

BiOX (X = Cl, Br, and I) semiconductors were firstly prepared by a facile mixed solvent solvothermal route. Several characterization tools were employed to study the phase structures, morphologies, and optical properties of the samples. The in situ chemically mixed prepared BiOX particles with diameters 3.0–5.0 μm, fabricated by nanoplates in the thickness range of 5–18 nm, exhibited the highest visible-light photocatalytic activity among the as-prepared samples and Degussa P25 for the degradation of Rhodamine B (RhB). This result can be due to the narrow bandgap, broad sunlight range, high electronic negativity, and efficient separation of photoinduced electron–hole pairs. Finally, a possible photocatalytic mechanism has been proposed.