A design of generalized minimum-state-change FSSP algorithms and their implementations

The firing squad synchronization problem (FSSP) on cellular automata has been studied extensively for more than 50 years, and a rich variety of FSSP algorithms has been proposed. Here we consider the FSSP from a view point of state-change complexity that models the energy consumption of SRAM-type storage with which cellular automata might be built. In the present paper, we propose minimum-state-change generalized FSSP (GFSSP) algorithms for synchronizing any one-dimensional (1D) cellular automaton, where the initial synchronization operation is started by any cell in the array. First, we construct two minimum-time, minimum-state-change GFSSP implementations on finite state automata: one is based on Goto’s algorithm, known as the first minimum-time FSSP algorithm that was reconstructed again recently in Umeo et al. (A new reconstruction and the first implementation of Goto’s FSSP algorithm, 2017), and the other is based on Gerken’s (Diplomarbeit, Institut für Theoretische Informatik, Technische Universität Braunschweig, pp 1–50, 1987) one. These implementations are optimal not only in time but also in the state-change complexity. The implementations of the minimum-time GFSSP algorithms are the first ones having the minimum-state-change complexity. In addition, we also present a six-state 145-rule non-minimum-time, minimum-state-change GFSSP implementation. The implemented GFSSP algorithm is the smallest one, known at present, in number of states of the finite state automaton.     

Analyzing the status of submerged aquatic vegetation using novel optical parameters

The reservoirs constructed throughout Brazil for electrical power generation following its industrial and socioeconomic development now favour abundant aquatic macrophyte growth. Nova Avanhandava Reservoir is fully inhabited by submerged aquatic vegetation (SAV) that poses serious ecological and economic threats. The overall goal of this study was to assess the radiation availability in the water column in the Nova Avanhandava Reservoir and analyse its influence on SAV development and growth. In addition to the diffuse attenuation coefficient (K_d) and euphotic zone depth (Z_EZ), optical parameters such as percentage light through the water (PLW) were computed and analysed to achieve the objective. Nineteen sampling locations were considered for both spectroradiometer measurements and water sampling for analytical determination of total suspended solids (TSS) and chlorophyll-a concentration. Depth, SAV height, and precise position were also collected through hydro-acoustic measurements. The upstream region showed the highest TSS and K_d levels compared to the downstream. SAV heights were found to be lower upstream compared to downstream. The growth of tall SAV was favoured by low PLW, which grew taller to intercept required radiation. Locations with high transparency (lower K_d) also favoured the development of tall SAV compared to areas of high K_d. This may mean that low PLW values favour tall SAV growth if K_d is low enough not to hinder this. An inverse relationship between SAV height and attenuation of photosynthetic active radiation (K_d,PAR) was observed with a coefficient of determination of R² = 0.56 (p < 0.001), demonstrating that SAV height can be estimated using K_d,PAR with significant accuracy.     

Separation of oil-in-water emulsions by microbubble treatment and the effect of adding coagulant or cationic surfactant on removal efficiency

This study examined the efficiencies of microbubble (MB) treatment, MB treatment with polyaluminium chloride (PAC) as a coagulant, and MB treatment with cetyltrimethylammonium chloride (CTAC) as a cationic surfactant in the separation of emulsified oil (EO) by modified column flotation. Batch mode experiments were conducted by synthesizing emulsified palm oil (d<20 μm), and the chemical oxygen demand (COD) of the influent and effluent was measured to evaluate the treatment performance. MB treatment with PAC and MB treatment with CTAC were found to be more efficient in EO removal than the MB treatment alone. At an EO concentration of ～1,000 mg L(-1) (pH 7) and under identical treatment conditions (MB generation time: 2.5 min, flotation time: 30 min), MB treatment with PAC (50 mg L(-1)) and that with CTAC (0.5 mg L(-1)) showed equally high EO removal efficiencies of 92 and 89%, respectively. This result is of significant relevance to studies focusing on the development of economical and high-efficiency flotation systems. Furthermore, the effect of pH was investigated by varying the sample pH from 3 to 8, which showed that the EO separation efficiency of MB alone increased drastically from slightly alkaline to acidic condition.     

Removal of hydrogen sulfide using palygorskite in a fixed bed adsorber

This work describes the use of a novel palygorskite, a type of magnesium aluminium silicate clay possessing a high specific surface area and pore surface activity, as a low cost and highly efficient adsorbent for hydrogen sulfide (H(2)S) removal. Adsorption of H(2)S on palygorskite pretreated with acid or base was investigated in a fixed bed adsorber. The samples after base pretreatment had better dynamic adsorption performances than raw material and samples pretreated with acid. The H(2)S adsorption capacity decreased with an increase in inlet H(2)S concentration. This can be interpreted by the fact that H(2)S adsorption on the surface of palygorskite is chemisorption. The adsorption capacity increased from 25 to 50 °C, then decreased from 50 to 100 °C, which indicates that chemisorption took place and its better reaction temperature was around 50 °C.     

Detection of heat transfer media in edible oil

Volatile substances obtained by steam distillation were analyzed by gas chromatography for the detection of heat transfer media in contaminated edible vegetable oil. It was found that a recovery of more than 90% of the contaminant was obtained by distillation of 10 g sample oil for 120 min and that a larger quantity of sample oil caused a decrease of recovery ratio. The detection limits were 0.2 ppm for Dowtherm A and 0.5 ppm for KSK Oil 260. It was found also that this method can be applied to the detection of heat transfer media in the secondary products, such as mayonnaise, salad dressing, and french dressing.     

Hot-Pressing of β-SiC Powder with Al-B-C Additives

The sintering behavior of β-SiC powders with additions of Al, B, and C was studied at 1600° to 1800°C with applied pressures of 20 to 60 MPa. Ceramics with densities of ∼3.08 g/cm³ were obtained by hot-pressing at 1650°C and 50 MPa. The bending strength did not degrade up to 1200°C. A large amount of a second phase, which was apparently Al₈B₄C₇, was observed as streaks in the microstructure. It is suggested that a liquid phase, which coexisted with this compound, enhanced densification.     

Environmental crazing and intrinsic tensile deformation in polymethylmethacrylate

The tensile stress-strain behaviour of PMMA was measured from 77 to 350 K in He which provides an inert environment and in N₂, Ar, O₂, CO₂, and water which cause crazing. The effect of the partial pressure of the crazing agent on the tensile properties was measured. It was found that the ratio of the tensile strength in a crazing environment to that in an inert environment depended on temperature and pressure as follows: _c/ _i={P exp (Q/RT)/P*}^–0.13 where P ^* and Q depend on the crazing agent. The critical temperature and pressure which determine when a gas ceases to produce an environmental effect on the tensile strength is given by the condition that P exp (Q/RT)<P ^*. Above 273 K the intrinsic deformation changed from brittle fracture to a combination of intrinsic crazing and shear.     

Nano-sized crystallites of vanadyl pyrophosphate as a highly selective catalyst for n-butane oxidation

Exfoliation-reduction of VOPO₄ · 2H₂O in a mixed alcohol consisting of 2-butanol and ethanol, followed by the thermal treatment in the presence of n-butane, O₂, and He at 663 K for 300 h, produces novel nano-sized crystallites (~ 50 nm) of (VO)₂P₂O₇. The nano-sized (VO)₂P₂O₇ crystallites exhibit a high selectivity to maleic anhydride (~ 84%) for the selective oxidation of n-butane.