Seismic Rehabilitation of Tall Steel Moment Resisting Frames Damaged by Fire with SMA-Based Hybrid Friction Damper

International Journal of Steel Structures - The existence probability of buildings, which have been under fire and not been collapsed for various reasons is not low, thus they are in dangerous...     

Optimal and near-optimal algorithms for multiple fault diagnosiswith unreliable tests

We consider the problem of constructing optimal and near-optimal multiple fault diagnosis (MFD) in bipartite systems with unreliable (imperfect) tests. It is known that exact computation of conditional probabilities for MFD is NP hard. The novel feature of our diagnostic algorithms is the use of Lagrangian relaxation and subgradient optimization methods to provide: 1) near optimal solutions for the MFD problem and 2) upper bounds for an optimal branch and bound algorithm. The proposed method is illustrated using several examples. Computational results indicate the following: 1) our algorithm has superior computational performance to the existing algorithms (approximately three orders of magnitude improvement over the algorithm by Z. Binglin et al. (1993)); 2) near optimal algorithm generates the most likely candidates with a very high accuracy; 3) our algorithm can find the most likely candidates in systems with as many as 1000 faults     

Finite dimensional filters with non-linear drift IX Construction of finite dimensional estimation algebras of non-maximal rank

The idea of using estimation algebra to construct finite-dimensional nonlinear filters was first proposed by Brockett and Mitter independently. It has proven to be an invaluable tool in the study of nonlinear filtering problem. In 1983, Brockett proposed to classify all finite-dimensional estimation algebras. In this paper, we give the construction of finite-dimensional estimation algebras of non-maximal rank. These non-maximal rank finite-dimensional estimation algebras play an important role in Brockett's classification problem.     

The Lichtenstein open "tension-free" mesh repair of inguinal hernias

All standard methods of hernia repair involve suturing together tissues which are not normally in apposition. This violates the basic surgical principle that tissue must never be approximated under tension and thus accounts for an unacceptable number of failures. A total reinforcement of the inguinal floor with a sheet of suitable biomaterial and the employment of a "tension-free" technique is a more effective approach. Since June of 1984, 4,000 primary inguinal hernias have been repaired on an outpatient basis and under local anesthesia at the Lichtenstein Hernia Institute by the open "tension-free" technique using Marlex mesh. The patients were followed from one to 11 years (mean of 5 years) by physician examination. The follow-up rate was 87%. There were four recurrences. The causes of recurrence and how to avoid them are discussed herein. Three of the recurrences occurred at the public tubercle and were caused by placing the mesh in juxtaposition to the tubercle. This error has since been corrected by overlapping the mesh at the public bone. One recurrence was caused by disruption of the lower edge of the mesh from the shelving margin of Poupart's ligament. The error here was the utilization of a patch that was too narrow and therefore under tension. It became apparent that a wider patch, fixed in place with an appropriate degree of taxity, was required.     

Definition of the optimum freezing rate-1. Investigation of structure and ultrastructure of beef M. longissimus dorsi frozen at different freezing rates

The influence of freezing rate on location, shape and size of ice crystals formed during freezing of beef M. longissimus dorsi, as well as its influence on ultrastructure, were investigated. Muscle samples were frozen at different rates: 0·22 cm/h and 0·39 cm/h (cooling agent was chilled air), and 3·33 cm/h, 3.95 cm/h, 4·92 cm/h and 5·66 cm/h (cooling agent was liquid carbon dioxide which expanded in the sucking-pipe of the tunnel freezer).

It was found that by slow freezing (freezing rates 0·22 cm/h and 0·39 cm/h) 30·00 μm). An increase in the freezing rate was followed by a change in ice crystal location. In this case they had also been formed intracellularly. The number of crystals increased while their size decreased.

The most intensive fibre damage was found in samples frozen at a rate of 0·22 cm/h, and the least in samples frozen at a rate of 3·95 cm/h with a freezing temperature of −50°C.     

The finite volume spectral element method to solve Turing models in the biological pattern formation

It is well known that reaction-diffusion systems describing Turing models can display very rich pattern formation behavior. Turing systems have been proposed for pattern formation in various biological systems, e.g. patterns in fish, butterflies, lady bugs and etc. A Turing model expresses temporal behavior of the concentrations of two reacting and diffusing chemicals which is represented by coupled reaction-diffusion equations. Since the base of these reaction-diffusion equations arises from the conservation laws, we develop a hybrid finite volume spectral element method for the numerical solution of them and apply the proposed method to Turing system generated by the Schnakenberg model. Also, as numerical simulations, we study the variety of spatio-temporal patterns for various values of diffusion rates in the problem.     

Effect of different drying methods on chemical and molecular structure of heteropolysaccharide–protein gum from durian seed

The functional properties and biological aspects of a natural biodegradable biopolymer depend on its chemical and molecular structure. In this study, the effect of different drying processes on the chemical and molecular structure of the natural biodegradable biopolymer from durian seed was investigated. The chemical structure was analyzed by assessing the carbohydrate profile, protein, amino acid composition, moisture, and ash. Molecular weight (M_w), number average molecular weight (M_n), M_w/M_n ratio and mass recovery were assessed by using a size-exclusion chromatography coupled to multi angle laser light-scattering (SEC-MALS). The present study revealed that main monosaccharides in the chemical structure of differently dried durian seed gums were galactose (50.1–64.9%), glucose (29.4–45.7%%), arabinose (0.11–0.89%), and xylose (0.019–0.86%). The protein analysis indicated the presence of a low amount of the protein fraction (3.2–3.9%) in the chemical structure of the biopolymer from durian seed. The most abundant amino acids in the chemical structure of durian seed gum were leucine (31.78–43.02%), lysine (6.23–7.78%), aspartic acid (6.45–8.58%), glycine (6.17–7.27%), glutamic acid (5.43–6.55%), alanine (4.60–6.23%), and valine (4.49–5.52). The current study exhibited that the biodegradable biopolymer from durian seed was a heteropolysaccharideprotein complex with medium M_w ranging from 1.06 × 10⁵ to 1.15 × 10⁵ (g/mol).     

Fabrication of superhydrophobic unplasticized poly(vinyl chloride)/nanosilica sheets using Taguchi design methodology

This study introduces a relatively simple technique for the manufacture of superhydrophobic coatings on polymeric surfaces. Plastics such as unplasticized poly(vinyl chloride) (UPVC ) do not have a strong hydrophobic nature that is characterized by their low contact angles. Techniques of both increasing surface roughness and lowering surface energy are required to change their hydrophilicity to superhydrophobicity. In the present study, a coating of a low‐surface‐energy thermoplastic polyurethane (TPU ) was spin‐coated with chemically treated nanosilica to reduce the surface energy of UPVC . Nanosilica particles were embedded on the surface using a hot‐press. Taguchi design was used to optimize multiple processing parameters. Samples spin‐coated with 10 g L^?1 nanosilica suspension in ethanol at a rate of 400 rpm for 5 s and then hot‐pressed at 155 °C under 2 atm (203 kPa ) for 4 min had a contact angle of ca 157° and sliding angle of ca 6°, which are characteristic of superhydrophobic surfaces. Atomic force microscopy (AFM) and scanning electron microscopy (SEM ) imaging showed that these superhydrophobic surfaces were highly rough with nanoscale features. Peel test and SEM analysis showed that silica nanoparticles embedded in the TPU coating were more stable than particles immobilized on UPVC sheet without TPU coating, proving that a layer of more flexible coating can improve the longevity of superhydrophobic surfaces manufactured using this facile method. © 2016 Society of Chemical Industry     

GVSEE: a new global model to estimate software services development effort

As software services have become a main part of companies in recent years, accurate and efficient estimates of required effort for their development has turned into a major concern. Furthermore, the high diversity, complexity, non-normality, and inconsistency of software services have made an estimation of the needed development effort a very difficult task. In spite of the numerous studies conducted, and improvements made, in the past, no single model has yet been introduced that can reliably estimate the required effort. Therefore, apparently, it is impossible to introduce a global and efficient model for all types of services. This article proposes a new model called Global Village Service Effort Estimator that emphasizes the idea ‘Think locally, act globally.’ Unlike previous studies, this model does not rely on a specific method and, in addition to combining methods, takes a local look at each software service with the help of fuzzy clustering. The model was evaluated on a real data-set International Software Benchmarking Standard Group and on two artificial data-sets, and obtained results indicated its tangible efficiency and the lack of accuracy of other models. Besides its greater accuracy, other advantages of the proposed model over the other models are its adaptability and flexibility in confronting complexities and uncertainties.     

Rheological Properties and Emulsifying Activity of Gum Karaya (Sterculia Urens) in Aqueous System and Oil in Water Emulsion: Heat Treatment and Microwave Modification

Gum karaya is a polysaccharide gum from Sterculia urens tree. It is used as an emulsifier and thickening agent in cosmetics and pharmaceuticals. However, it has very strong swelling properties, high viscosity, and low solubility, providing the restricted applications in the food industry. The main objective of this study was to investigate the effects of different heat treatment and microwave variables (i.e., time: 8, 10, and 12 min; power: 700 and 1000 W) on the functional properties of gum karaya in the aqueous system and oil-in-water emulsion. In this regard, the rheological properties, emulsifying activity, average droplet size, and surface morphology of the native- and microwave-treated gums were analyzed and compared. Dynamic oscillatory test indicated that the microwave-treated gum karaya had more gel-like behavior than viscous-like behavior (G′ > G″) at a relatively high concentration (20% or 20 g/100 g). When gum karaya was treated by microwave for 8–12 min, both elastic (G′) and viscous (G″) moduli were declined. The native- and microwave-treated gum karaya exhibited a shear-thinning (pseudoplastic) behavior in the aqueous system and oil-in-water emulsion. The results showed that the microwave-treated gum karaya had smaller particles than the native gum in the aqueous system. On the other hand, the emulsion containing the microwave-treated gum karaya had finer emulsion droplets than the control containing the native gum karaya. This confirmed that the application of microwave treatment led to significantly (p < 0.05) improve the emulsifying activity of gum karaya.