Active Rule Termination Analysis: An Implementation and Evaluation of the Refined Triggering Graph Method

This paper describes the implementation of the Refined Triggering Graph (RTG) method for active rule termination analysis and provides an evaluation of the approach based on the application of the method to a sample active application. The RTG method has been defined in the context of an active-deductive, object-oriented database language known as CDOL (Comprehensive, Declarative, Object Language). The RTG method studies the contents of rule pairs and rule cycles in a triggering graph and tests for: (1) the successful unification of one rule's action with another rule's triggering event, and (2) the satisfiability of active rule conditions, asking whether it is possible for the condition of a triggered rule to evaluate to true in the context of the triggering rule's condition. If the analysis can provably demonstrate that one rule cannot trigger another rule, the directed vector connecting the two rules in a basic triggering graph can be removed, thus refining the triggering graph. An important aspect in the implementation of the method is the development of a satisfiability algorithm for CDOL conditions. This paper presents the tool that was developed based on the RTG method, describing how techniques from constraint logic programming are integrated with other techniques for testing the satisfiability of rule triggering conditions. The effectiveness of the approach within the context of a sample application is also addressed.     

Saccharomyces cerevisiae strains and the reduction of Aspergillus parasiticus growth and aflatoxin B1 production at different interacting environmental conditions,in vitro

The effect of Saccharomyces cerevisiae RC008 and RC016, previously selected based on their aflatoxin B₁ binding ability and beneficial properties, against Aspergillus parasiticus under different interacting environmental conditions was evaluated. Studies concerning the lag phase, growth rate and aflatoxin B₁ production were carried out in vitro under different regimes of a _w (0.95 and 0.99), pH (4 and 6), temperature (25 and 37°C), and oxygen availability (normal and reduced). Both yeast strains showed great antagonistic activity at pH 4, decreasing growth rate compared with the control. The RC008 strain showed the greatest inhibitory activity at all assayed conditions. A. parasiticus produced large amounts of AFB₁ in vitro. A significant decrease of AFB₁ levels in comparison with the control were observed with yeast interaction. Differences between control and treatment values ranged from 130 to 5400?ng?ml^?1. S. cerevisiae RC008 and RC016 could be considered as effective agents in reducing growth and AFB₁ production at different interacting environmental conditions, related to that found in stored feedstuff. The importance of the present work lies in the search for live strains with both probiotic and biocontrol properties able to prolong the safe storage of feedstuff and exert beneficial properties after animal consumption and which could be included in a novel product for animal feed.     

Factors affecting Penicillium roquefortii (Penicillium glaucum) in internally mould ripened cheeses: implications for pre‐packed blue cheeses

The amount and vivid colour of blue veins of internally mould ripened cheeses are desirable quality characteristics. It is therefore important that there is a sufficient amount of veining and that it maintains its blue appearance to be appealing to consumers therefore leading to maximised sales potential and profit for the manufacturing company. Optimum in vitro growth mimicking the conditions typically found in pre‐packed blue cheeses, and using lactose as the sole carbon source, was facilitated by a gas mixture of 5% oxygen/0% carbon dioxide/balance nitrogen). The work undertaken in this study determined that the factors for optimum in vitro growth of Penicillium roquefortii (strain PRB6) were: a temperature of 20 ± 1 °C, pH of 6.0 ± 0.1, and a relative humidity of 70 ± 0.1%. Further in vitro studies have also shown that the increasing ‘in‐pack’ carbon dioxide concentration not only depresses the growth of P. roquefortii but also affects immature conidiospore pigmentation (no effect has been seen on mature conidiospore pigmentation). The implications of this study suggest that the majority of pre‐packed internally mould ripened blue cheeses on sale in supermarkets are packaged in inappropriate materials. For some cheeses (e.g. the Roquefort‐type cheeses) this is not an issue since these are packed in a much more mature state and some loss of veining colour is not appreciably noticeable.     

Effect of silicon solar cell processing parameters and crystallinity on mechanical strength

Silicon wafer thickness reduction without increasing the wafer strength leads to a high breakage rate during subsequent handling and processing steps. Cracking of solar cells has become one of the major sources of solar module failure and rejection. Hence, it is important to evaluate the mechanical strength of solar cells and influencing factors. The purpose of this work is to understand the fracture behavior of silicon solar cells and to provide information regarding the bending strength of the cells. Triple junctions, grain size and grain boundaries are considered to investigate the effect of crystallinity features on silicon wafer strength. Significant changes in fracture strength are found as a result of metallization morphology and crystallinity of silicon solar cells. It is observed that aluminum paste type influences the strength of the solar cells.     

Optimisation of lipase production by a mutant of Candida antarctica DSM‐3855 using response surface methodology

Response surface methodology (RSM) was used to determine the optimum cultivation conditions for lipase production by a mutant strain of Candida antarctica DSM‐3855. Among four variables, initial pH, soybean meal, and temperature were identified as significant variables for lipase production by full factorial design. A mathematical model was developed to investigate the influences of three factors on lipase activity and to predict their optimum value. According to RSM, the optimum cultivation conditions for the maximum lipase production were found to be: initial pH 6.0, soybean meal 3.38% (w/v), and temperature 26 °C. Under the optimum conditions, the maximum lipase yields of 27.34 U mL^?1 was obtained after 58 h of cultivation in a 15 L fermenter.     

Experimental study about the effects of disc chipper settings on the distribution of wood chip size

Nowadays wood should be of principal sources of biomass. This wood is transformed into chips in order to increase automatic operations and to decrease the technical effort needed at the energy conversion plant. Typical high quality chips, which are used to feed small woodchip boilers, vary in size from 10 × 10 × 5 mm to 15 × 15 × 8 mm. Chips that are relatively square and flat are easily conveyed, augured, and fed into the system smoothly. We are mainly interested in the raw material of inferior quality. A disc chipper test bench was constructed in our laboratory to study the chipping process in cutting conditions which are similar to those used in the industry. The test bench design allows many factors to be varied include cutting speed, feed per tooth, cutting angles, anvil height and cutting direction. In this paper, we attempt to understand the effect of several factors on chip size distribution. Four feeds per tooth, four cutting angles, two sharpness angles and three cutting speeds were chosen to cut wet logs of oak and fir wood, while the other factors remained constant. The results are similar for both oak and fir. The proportion of small chips decreases when we increase the feed per tooth, the cutting angle and the sharpness angle, whereas it increases when the cutting speed is increased. The feed per tooth and the cutting speed have a linear effect on the variations in the size distribution, while the cutting angle has a non-linear effect on these variations.     

同源高速宏观地质条件对勘察的指导意义

对同源高速公路地貌景观进行了分析,并针对不同地质条件下的工程地质特征进行了工作量布置前的探讨,综合研究后进行了勘察工作,合理指导了勘察与工程建设,对同类工程具有重要的指导意义。     

Factors affecting the intention to use a web-based learning system among blue-collar workers in the automotive industry

This study aims to identify, using an extended Technology-Acceptance Model (TAM), the factors affecting the decision of using a web-based learning system among blue-collar workers in the automotive industry. A structural equation-modeling approach was applied to identify the variables that significantly affect the decision of using the system. Using LISREL 8.54, data collected from 546 blue-collar workers were used to test the proposed research model. Empirical testing of the extended TAM found all paths to be significant in the hypothesized directions, that is, the results of the study strongly support the application of extended TAM in predicting the blue-collar workers’ intention to use a web-based learning system. Among the factors, social influence is a much stronger predictor of user intention compared to others. The study concludes with the implications of this study for managers and recommendations for possible future research.     

石油污染土壤中石油降解菌的筛选及降解特性研究

从辽河油田石油污染土壤中采取土样,经过富集分离筛选后得到单一的石油降解菌株,命名为G1。通过对菌株形态特征和生理生化特性的分析,初步鉴定为芽孢杆菌属,对原油的降解率为21%。对G1菌株的降解条件进行优化,通过正交实验得到最佳降解条件为:N源为(NH4)2SO4,P源为K2HPO4,pH为8,接种量为3 ml,原油浓度为0.2%,对最优组合进行实验验证得到原油的降解率达到45%。     

Microstructure and corrosion performance of X100 steel in the oilfield produced water

ABSTRACT

The corrosion performances of X100 steels in the oilfield produced water with different temperature (30°C, 40°C, 60°C) under the simulated working conditions were studied by potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) test. Energy dispersive spectroscopy (EDS) was used to measure the element composition of the sample after corrosion. The phase and chemical compositions of the specimens were analyzed by X-ray diffraction (XRD) and Raman spectrometry. The electrochemical results showed that the corrosion resistance of the specimen exposed for 24 hours increased with the increase of the testing temperature, indicating the better protective effect due to the corrosion product film formed under high temperature despite the impact of turbulence. The corrosion products consist of Fe₃O₄, Fe₂O₃, α-FeOOH, and γ-FeOOH. The corrosion mechanism model of X100 steel was established and the corrosion behavior was analyzed under simulated working conditions.