Optimizing Multi-stage Production for an Assembly-Type Supply Chain with Unequal Sized Batch Shipments

This paper studies the multi-stage logistics and inventory problem in an?assembly-type supply chain where a uniform lot size is produced uninterruptedly with a single setup at each stage. Partial lots, or sub-batches, can be transported to next stage upon completion. Unequal sub-batch sizes at each stage follow geometric series and the numbers of sub-batches across stages are allowed to be different. Since the mainline and each branch line of an assembly-type supply chain are series-type supply chains, a model of the series-type supply chain is first established and a model of the assembly-type supply chain is subsequently developed. Optimization algorithms that determine the economic lot sizes, the optimal sub-batch sizes and the number of sub-batches for each stage are developed. The polynomial-time algorithms incorporate the optimality properties derived in the paper to find the lower and upper bounds of the solutions by constructing the solution ranges and then the optimal solutions accordingly.     

Amphoteric refraction exhibited by anisotropic crystals

Amphoteric refraction of light ray at the interface between isotropic materials and anisotropic materials is analyzed. Depending on the incident angle, the refractive light ray can either refract positively or negatively. This amphoteric refraction phenomenon can be quite prevalent when the difference of the two principal refractive indices is large. The reflectance under various incident angles has also been calculated, and an experimental demonstration with a calcite crystal in air is presented.     

Proteomic identification of salivary transferrin as a biomarker for early detection of oral cancer

Oral cancer has a low five-year survival rate. Early detection of oral cancer could reduce the mortality and morbidity associated with this disease. Saliva, which can be sampled non-invasively and is less complex than blood, is a good potential source of oral cancer biomarkers. Proteomic analysis of saliva from oral cancer patients and control subjects was performed to identify salivary biomarkers of early stage oral cancer in humans. The protein profile of pooled salivary samples from patients with oral squamous cell carcinoma (OSCC) or OSCC-free control subjects was analyzed using two-dimensional gel electrophoresis (2DE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analyses. Potential biomarkers were verified by Western blotting and ELISA assays. Transferrin levels were elevated in the saliva of OSCC patients as determined using 2DE followed by MALDI-TOF MS and confirmed by MALDI-TOF/TOF MS, Western blotting and ELISA. The increase in salivary transferrin levels in OSCC patients strongly correlated with the size and stage of the tumor. The area under the receiver-operating characteristics curves showed that salivary transferrin-based ELISA was highly specific, sensitive and accurate for the early detection of oral cancer. We have identified salivary transferrin as a biomarker for the detection of early stage oral cancer. This finding provides a promising basis for the development of a non-invasive diagnostic test for early stage oral cancer.     

Managing pharmaceuticals delivery service using a hybrid particle swarm intelligence approach

Medicines or drugs have unique characteristics of short life cycle, small size, light weight, restrictive distribution time and the need of temperature and humidity control (selected items only). Thus, logistics companies often use different types of vehicles with different carrying capacities, and considering fixed and variable costs in service delivery, which make the vehicle assignment and route optimization more complicated. In this study, we formulate the problem to a multi-type vehicle assignment and mixed integer programming route optimization model with fixed fleet size under the constraints of distribution time and carrying capacity. Given non-deterministic polynomial hard and optimal algorithm can only be used to solve small-size problem, a hybrid particle swarm intelligence (PSI) heuristic approach, which adopts the crossover and mutation operators from genetic algorithm and 2-opt local search strategy, is proposed to solve the problem. We also adapt a principle based on cost network and Dijkstra’s algorithm for vehicle scheduling to balance the distribution time limit and the high loading rate. We verify the relative performance of the proposed method against several known optimal or heuristic solutions using a standard data set for heterogeneous fleet vehicle routing problem. Additionally, we compare the relative performance of our proposed Hybrid PSI algorithm with two intelligent-based algorithms, Hybrid Population Heuristic algorithm and Improved Genetic Algorithm, using a real-world data set to illustrate the practical and validity of the model and algorithm.

     

Surface modification, martensitic transformation, and optical properties of hydrogenated ZrO2 nanocondensates via pulsed laser ablation in water

Pulsed laser ablation on Zr plate in water under Q-switch mode and a fluence of 700 and 800 mJ/pulse for a rather high power density of 1.5 and 1.7 × 10¹¹ W/cm², respectively, was employed to fabricate hydrogenated ZrO₂ nanocondensates. X-ray diffraction and transmission electron microscopic observations indicated such nanocondensates are full of {111} and {100} facets and predominantly in monoclinic (m-) rather than cubic- and/or tetragonal (t-) crystal symmetry in particular when fabricated at 700 mJ/pulse. The hydrogenated ZrO₂ nanocondensates underwent martensitic t ?? m transformation at a rather small critical size (ca. 20 nm) due to H⁺ signature and hence oxygen vacancy deficiency in the lattice. The resultant m-phase was free of twin and fault due to site saturation and rather limited growth of the nanosized particles. Spectroscopic characterizations indicated that the nanocondensates have a significant internal compressive stress, (H⁺, Zr²⁺, Zr³⁺) co-signature and hence a smaller band gap of 5.2?C5.3 eV for potential applications in UV region.     

Nickel aluminate oxides/hydroxides by pulsed laser ablation of NiAl2O4 powder in water

Submicron-sized NiAl_2+X O₄ fragments and nanocondensates of Ni-doped γ-Al₂O₃, Al-doped NiO and β-Ni(OH)₂ were synthesized simultaneously by pulsed laser ablation of NiAl₂O₄ powder in water and characterized using X-ray/electron diffraction and optical spectroscopy. The NiAl_2+X O₄ is Al-enriched spinel with dislocations and subgrains. The Ni-doped γ-Al₂O₃ spinel has paracrystalline distribution (i.e., with fair constant longitudinal spacing, but variable relative lateral translations) of defect clusters and intimate intergrowth of θ-Al₂O₃ and 2x( \( \overline{1} \) 3 \( \overline{1} \) ) commensurate superstructure. The Al-doped NiO has perfect cubo-octahedron shape and as small as 5 nm in size. The β-Ni(OH)₂ and 1-D turbostratic hydroxide lamellae occurred as a matrix of these oxide nanoparticles. The colloidal suspension containing the composite phases has a minimum band gap of 5.3 eV for potential photocatalytic applications.     

A travel time estimation model for a high-level picker-to-part system with class-based storage policies

Most previous related studies on warehouse configurations and operations only investigated single-level storage rack systems where the height of storage racks and the vertical movement of the picking operations are both not considered. However, in order to utilize the space efficiently, high-level storage systems are often used in warehouses in practice. This paper presents a travel time estimation model for a high-level picker-to-part system with the considerations of class-based storage policy and various routing policies. The results indicate that the proposed model appears to be sufficiently accurate for practical purposes. Furthermore, the effects of storage and routing policies on the travel time and the optimal warehouse layout are discussed in the paper.     

Thermal characteristics in the annulus with an inner rotating rib-roughness cylinder

This work experimentally investigates the heat transfer characteristics in the annulus with an inner rotating rib-roughness cylinder, whose flow and thermal behaviors are associated with Taylor number (Ta) and centrifugal buoyancy parameter (Gr _Ω/Ta). The operating range of Ta is from 4.90 × 10² to 5.80 × 10⁵, while the surface of the inner cylinder is heated up with several constant heat fluxes (279, 425 and 597 W/m²) to obtain various values of Gr _Ω/Ta. Besides, three modes of the inner cylinder without/with longitudinal ribs are considered. The end of the annular channel is connected to a side chamber to fit practical applications (such as in the rotary blade coupling of a four-wheel-drive vehicle). The experimental results show that the average Nusselt number was almost constant at low Ta, but increased rapidly with Ta when Ta exceeded some critical value (3,000–5,200 for present study). Additionally, the Gr _Ω/Ta effect on the heat transfer was negligible herein. Furthermore, by comparing with the inner cylinder without longitudinal ribs, stalling ribs on the inner cylinder increases the transport of heat by a factor of 1.22 at 10⁵ < Ta < 10⁶, and embedding cavities into the ribs increases the transport of heat by a factor of 1.16 at 10⁵ < Ta < 10⁶. Finally, the relationships between the and the Ta for various modes of test sections were proposed.     

Power Generation Capabilities of Microbial Fuel Cells with Different Oxygen Supplies in the Cathodic Chamber

Two microbial fuel cells (MFCs) inoculated with activated sludge of a wastewater treatment plant were constructed. Oxygen was provided by mechanical aeration in the cathodic chamber of one MFC, whereas it was obtained by the photosynthesis of algae in the other. Electrogenic capabilities of both MFCs were compared under the same operational conditions. Results showed that the MFC with mechanical aeration in the cathodic chamber displayed higher power output than the one with photosynthesis of algae. Good linear relationship between power density and chemical oxygen demand (COD) loading rate was obtained only on the MFC with mechanical aeration. Furthermore, the relationships between power density and effluent COD and between Coulombic efficiency and COD loading rate can only be expressed as binary quadratic equations for the MFC with mechanical aeration and not for the one with photosynthesis of algae.