Effect of Gelling Agent and Calcination Temperature in Sol–Gel Synthesized MgO Nanoparticles

Protection of Metals and Physical Chemistry of Surfaces - Magnesium oxide (MgO) is a versatile metal oxide with wide applications in electrical, chemical and pharmaceutical industries. Preparation...     

Towards the design of a scalable and commercially viable technique for plasmid purification using a methacrylate monolithic stationary phase

A monolithic stationary phase was prepared via free radical co‐polymerization of ethylene glycol dimethacrylate (EDMA) and glycidyl methacrylate (GMA) with pore diameter tailored specifically for plasmid binding, retention and elution. The polymer was functionalized with 2‐chloro‐N,N‐diethylethylamine hydrochloride (DEAE‐Cl) for anion‐exchange purification of plasmid DNA (pDNA) from clarified lysate obtained from E. coli DH5α‐pUC19 culture in a ribonuclease/protease‐free environment. Characterization of the monolithic resin showed a porous material, with 68% of the pores existing in the matrix having diameters above 300 nm. The final product isolated from a single‐stage 5 min anion‐exchange purification was a pure and homogeneous supercoiled (SC) pDNA with no gDNA, RNA and protein contamination as confirmed by ethidium bromide agarose gel electrophoresis (EtBr‐AGE), enzyme restriction analysis and sodium dodecyl sulfate–polyacrylamide gel electrophoresis. This non‐toxic technique is cGMP compatible and highly scalable for production of pDNA on a commercial level. Copyright © 2007 Society of Chemical Industry     

How Internet Security Breaches Harm Market Value

Decision-tree induction is an effective technique for examining the factors influencing abnormal stock market returns when security breaches are announced in the public media. In this article, the authors extend a previous study, specifically identifying new relationships between abnormal returns and firm and attack characteristics and subject them to traditional statistical testing. They relate their results to the confidential, integrity, and availability dimensions of information security and discuss the findings' technical and managerial implications. The Web extra for this article presents detailed event data.     

The comparative ability of four isolates of Bacillus subtilis to ferment soybeans into dawadawa

In an attempt to develop starter cultures for fermenting soybeans into the traditional West African condiment dawadawa, four isolates of Bacillus subtilis: 24BP(2), 72RP(17), 72BP(30), and FpdBP(2), which had been selected from 42 Bacillus cultures in a previous study by the current authors, were used separately to produce soy-dawadawa. The accompanying microbiological and biochemical changes, including enzymatic activities, as well as the organoleptic quality of the products were evaluated including that of a control sample which was fermented spontaneously. Significant differences existed in the ability of the four isolates to hydrolyse the soybean proteins, starch, and fat to produce dawadawa. Bacillus subtilis 24BP(2) recorded the highest protease and amylolytic activities, 101 U/ml and 26.68 mg/ml, respectively, and liberated the most amino acids, 117.64 mg/g dry wt., during fermentation. Bacillus subtilis 24BP(2) also grew to the highest population of cells in the final product. Taste panelists found soybean dawadawa produced by each of the four isolates acceptable and rated soup flavoured with soy-dawadawa produced by Bacillus subtilis FpdBP(2) as the best sample. Panelists scored it higher than the control sample and soy-dawadawa produced by Bacillus subtilis 24BP(2) in that order.     

Directive Decision Devices: Extending the reach of automation into the finance domain

Expert systems, decision support systems, and knowledge management systems are computer constructs that are designed to service human decision makers. There are however certain sorts of decision situations where, for some reason, responsibility might better be invested in a computer program, rather than a person. This paper points out several such situations that can be found in the contemporary financial management sector, and suggests how Directive Decision Devices might be equipped to deal with them on a stand-alone basis.     

Microalgal biomass as a fermentation feedstock for bioethanol production

BACKGROUND: The increasing cost of fossil fuels as well as the escalating social and industrial awareness of the environmental impacts associated with the use of fossil fuels has created the need for more sustainable fuel options. Bioethanol, produced from renewable biomass such as sugar and starch materials, is believed to be one of these options, and it is currently being harnessed extensively. However, the utilization of sugar and starch materials as feedstocks for bioethanol production creates a major competition with the food market in terms of land for cultivation, and this makes bioethanol from these sources economically less attractive. RESULT: This study explores the suitability of microalgae (Chlorococum sp.) as a substrate for bioethanol production via yeast (Saccharomyces bayanus) under different fermentation conditions. Results show a maximum ethanol concentration of 3.83 g L^?1 obtained from 10 g L^?1 of lipid‐extracted microalgae debris. CONCLUSION: This productivity level (～38% w/w), which is in keeping with that of current production systems endorses microalgae as a promising substrate for bioethanol production. Copyright © 2009 Society of Chemical Industry     

A modified model for the Lobula Giant Movement Detector and its FPGA implementation

Bio-inspired vision sensors are particularly appropriate candidates for navigation of vehicles or mobile robots due to their computational simplicity, allowing compact hardware implementations with low power dissipation. The Lobula Giant Movement Detector (LGMD) is a wide-field visual neuron located in the Lobula layer of the Locust nervous system. The LGMD increases its firing rate in response to both the velocity of an approaching object and the proximity of this object. It has been found that it can respond to looming stimuli very quickly and trigger avoidance reactions. It has been successfully applied in visual collision avoidance systems for vehicles and robots. This paper introduces a modified neural model for LGMD that provides additional depth direction information for the movement. The proposed model retains the simplicity of the previous model by adding only a few new cells. It has been simplified and implemented on a Field Programmable Gate Array (FPGA), taking advantage of the inherent parallelism exhibited by the LGMD, and tested on real-time video streams. Experimental results demonstrate the effectiveness as a fast motion detector.     

In‐process thermochemical analysis of in situ poly(ethylene glycol methacrylate‐co‐glycidyl methacrylate) monolithic adsorbent synthesis

Thermomolecular mechanisms associated with the synthesis of polymethacrylate monoliths are critical in controlling the physicochemical and binding characteristics of the adsorbent. Notwithstanding, there has been limited reported work on probing the underlining synthesis mechanism essential in establishing the relationship between in‐process polymerization characteristics and the physicochemical properties of the monolith for tailored applications. In this article, we present a real‐time thermochemical analysis of polymethacrylate monolith synthesis by free‐radical polymerization to probe the effects on the physicochemical characteristics of the adsorbent. The experimental results show that an increase in the crosslinker monomer concentration from 30 to 70% resulted in a peak temperature increase from 96.3 to 114.3 °C. Also, an increase in the initiator (benzoyl peroxide) concentration from 1 to 3% w/v resulted in a temperature increase from 90.7 to 106.3 °C. A temperature buildup increases the kinetic rate of intermolecular collision associated with microglobular formation and interglobular interactions. This reduces the structural homogeneity and macroporosity of the polymer matrix. A two‐phase reactive crystallization model was used to characterize the rate of monomeric reaction after initiation and microglobular formation from the liquid monomeric phase to formulate the theoretical framework essential for evaluating the kinetics of the polymer formation process. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43507.