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.     

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).     

Lactic Acid: An Efficient and Green Catalyst for the One-Pot Five-Components Synthesis of Highly Substituted Piperidines

ABSTRACT

Polyfunctionalized heterocyclic compounds have an important role in the drug discovery process and analysis of drugs in late development. Piperidines and their analogues have received attention owing to their biological activities, because of the importance of these heterocycle compounds, there is still a need to improve the ways for green synthesis of these compounds. In this study, lactic acid was applied as a green and efficient catalyst for the one-pot five-component synthesis of highly substituted piperidines from the reaction between aromatic aldehydes, aromatic amines, and b-ketoester at ambient temperature. This methodology has a number of advantages such as: use of easy access and green catalyst, short reaction times, high yields, and easy work-up (just simple filtration).     

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.     

Biomass and lipid productivities of marine microalgae isolated from the Persian Gulf and the Qeshm Island

In this work, the screening of 147 microalgal strains from the Persian Gulf and the Qeshm Island (Iran) were done in order to choose the best ones, in terms of growth (biomass) rate and lipid content for biodiesel production. A methodology, combining experiments in lab-scale and pilot plant (open pond) used to produce and evaluate biomass and lipid productivity is presented for the systematic investigation of the potential of different microalgae species. The culture conditions, including photo flux (180 ??E m⁻² s⁻¹), photoperiod (12 h light/dark), temperature (25 °C), pH (≈8), air (carbon dioxide) and growth medium, were kept constant for all experiments. Microalgae were screened in two stages using optical density (for evaluation of biomass concentration) and Nile red and gas chromatography (for determination of lipid content and fatty acid fractions). In general, maximum specific growth rate and the maximum biomass productivity were obtained after 8-12-day culture. Nannochloropsis sp. and Neochloris sp. were selected from the marine microalgal culture collection, due to their high biomass (50 and 21.7 g L⁻¹, respectively) and oil content (52% and 46%, respectively). If the purpose is to produce biodiesel only from one species, Nannochloropsis sp. presented the most adequate fatty acid profile, namely linolenic and other polyunsaturated fatty acids. However, the microalgae Chlorella sp. can also be used if associated with other microalgal oils. In addition, selected strains could be potent candidates for commercial production in the open pond culture.     

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.     

Continuous-mode photocatalytic degradation of chlorinated phenols and pesticides in water using a bench-scale TiO2 rotating disk reactor

Photocatalytic degradation of phenol, chlorinated phenols, and lindane was evaluated in a continuous flow TiO₂ rotating disk photocatalytic reactor (RDPR). The RDPR operated at a hydraulic residence time of 0.25 day and at a disk angular velocity of 12 rpm. At low molar feed concentrations (0.038 mmol/l), the removal efficiencies for phenol and chlorinated phenols were in the order of 86% or higher, whereas the removal efficiency for lindane at a feed concentration of 0.016 mmol/l was in the order of 63%.

For 2,4,6-trichlorophenol (TCP), an increase in the molar influent concentration resulted in a decrease in removal efficiency but in an increase in removal rate. The degradation rate of 2,4,6-TCP followed a saturation type dependancy with the effluent concentration, suggesting a Langmuir–Hinshelwood (L–H) reaction rate equation. A L–H equation was employed to determine the reaction rate constant and the adsorption coefficient for 2,4,6-TCP. The photonic efficiency increased from 0.68% at an influent concentration of 0.13 mmol/l to 2.06% at an influent concentration of 1.0 mmol/l.     

LMES: A localized multi-estimator model to estimate software development effort

Accurate estimation of software development effort is strongly associated with the success or failure of software projects. The clear lack of convincing accuracy and flexibility in this area has attracted the attention of researchers over the past few years. Despite improvements achieved in effort estimating, there is no strong agreement as to which individual model is the best. Recent studies have found that an accurate estimation of development effort in software projects is unreachable in global space, meaning that proposing a high performance estimation model for use in different types of software projects is likely impossible. In this paper, a localized multi-estimator model, called LMES, is proposed in which software projects are classified based on underlying attributes. Different clusters of projects are then locally investigated so that the most accurate estimators are selected for each cluster. Unlike prior models, LMES does not rely on only one individual estimator in a cluster of projects. Rather, an exhaustive investigation is conducted to find the best combination of estimators to assign to each cluster. The investigation domain includes 10 estimators combined using four combination methods, which results in 4017 different combinations. ISBSG, Maxwell and COCOMO datasets are utilized for evaluation purposes, which include a total of 573 real software projects. The promising results show that the estimate accuracy is improved through localization of estimation process and allocation of appropriate estimators. Besides increased accuracy, the significant contribution of LMES is its adaptability and flexibility to deal with the complexity and uncertainty that exist in the field of software development effort estimation.