Predicting Mechanical Strength of In-Use Firefighter Protective Clothing Using Near-Infrared Spectroscopy

The exact lifespan of in-use firefighter protective clothing is difficult to predict due to the large variations in use between individual garments. Furthermore, testing methods used to evaluate new protective clothing are destructive in nature and could not be applied to in-use garments. Various non-destructive techniques have been proposed for the evaluation of in-use clothing, each possessing its own advantages and disadvantages. The ability of near-infrared spectroscopy to predict the tensile strength of thermally aged fabrics used in protective clothing for wildland firefighters and other workers is investigated here. Fabrics were exposed to heat fluxes from 10 kW/m² to 40 kW/m² for various durations using the cone calorimeter, after which the tensile strength of the fabrics was measured. Temperatures measured during the exposures and results of thermal gravimetric analysis tests were used to interpret changes in tensile strength. Multivariate linear regression was used to develop correlations between the tensile strength and the reflectance values measured between 1500 nm and 2500 nm for new and thermally aged fabrics. It was found that models based on reflectance measurements made at as few as three wavelengths could be used to estimate the tensile strength of the thermally aged specimens.     

Interventions for long-term software security: Creating a lightweight program of assurance techniques for developers

Though some software development teams are highly effective at delivering security, others either do not care or do not have access to security experts to teach them how. Unfortunately, these latter teams are still responsible for the security of the systems they build: systems that are ever more important to ever more people. We propose that a series of lightweight interventions, six hours of facilitated workshops delivered over three months, can improve a team's motivation to consider security and awareness of assurance techniques, changing its security culture even when no security experts are involved. The interventions were developed after an Appreciative Inquiry and Grounded Theory survey of security professionals to find out what approaches work best. We tested the interventions in a participatory action research field study where we delivered the workshops to three software development organizations and evaluated their effectiveness through interviews beforehand, immediately afterwards, and after twelve months. We found that the interventions can be effective with teams with limited or no security experience and that improvement is long-lasting. This approach and the learning points arising from the work here have the potential to be applied in many development teams, improving the security of software worldwide.     

Qualitative and energy recovery potential analysis: plastic-derived fuel oil versus conventional diesel oil

Clean Technologies and Environmental Policy - Due to depleting fossil fuel sources, plastic-derived fuel oil (PDFO) has received much attention over the past decade as an alternative to...     

炮采放顶煤工作面采空区顶板抽放瓦斯实践

文章介绍了高瓦斯炮采放顶煤工作面采空区煤层顶板抽放瓦斯的实践,通过对钻场中钻孔抽放过程的跟踪测试、观察、归纳分析,总结出提高瓦斯抽放效率的最佳顶板裂隙带高度,并对关键性技术要点和裂隙带高度的确定提供了理论判定方法。     

Multi-laboratory evaluations of the performance of Catellicoccus marimammalium PCR assays developed to target gull fecal sources

Here we report results from a multi-laboratory (n = 11) evaluation of four different PCR methods targeting the 16S rRNA gene of Catellicoccus marimammalium originally developed to detect gull fecal contamination in coastal environments. The methods included a conventional end-point PCR method, a SYBR^® Green qPCR method, and two TaqMan^® qPCR methods. Different techniques for data normalization and analysis were tested. Data analysis methods had a pronounced impact on assay sensitivity and specificity calculations. Across-laboratory standardization of metrics including the lower limit of quantification (LLOQ), target detected but not quantifiable (DNQ), and target not detected (ND) significantly improved results compared to results submitted by individual laboratories prior to definition standardization. The unit of measure used for data normalization also had a pronounced effect on measured assay performance. Data normalization to DNA mass improved quantitative method performance as compared to enterococcus normalization. The MST methods tested here were originally designed for gulls but were found in this study to also detect feces from other birds, particularly feces composited from pigeons. Sequencing efforts showed that some pigeon feces from California contained sequences similar to C. marimammalium found in gull feces. These data suggest that the prevalence, geographic scope, and ecology of C. marimammalium in host birds other than gulls require further investigation. This study represents an important first step in the multi-laboratory assessment of these methods and highlights the need to broaden and standardize additional evaluations, including environmentally relevant target concentrations in ambient waters from diverse geographic regions.     

基于三维漏磁测量的腐蚀检测探头设计

在传统一维漏磁检测的基础上,为了获取更多特征信息以提高漏磁检测对缺陷的识别能力,提出了三维漏磁检测新方法.较传统一维检测,三维漏磁检测对信号采集系统有着更高的要求,本文适时提出了一种适应三维漏磁检测的磁场测量探头的设计方案,并已经在实验现场得到应用.     

血管紧张素(1-7)的神经活性研究进展

血管紧张素(1-7)［angiotensin(1-7),Ang(1-7)］通过肾素-血管紧张素系统(renin-angiotensin system,RAS)新的作用分支血管紧张素转化酶2(angiotensin-converting enzyme 2,ACE2)-血管紧张素(1-7)-Mas受体(ACE2-Ang(1-7)-Mas)轴反向调节经典ACE-AngII-AT受体轴。Ang(1-7)广泛存在于下丘脑视上核和室旁核,可以通过缓激肽、一氧化氮合酶(NOS)、环氧合酶(COX)及一些信号通路影响其他中枢神经递质的合成及释放,发挥扩张血管、抗心律失常、抗炎等作用,达到保护心血管及中枢神经系统的效果。本文就Ang(1-7)的分布及在中枢神经系统中多样性的生物功能作一综述。     

旋转导向钻井系统中振动加速度的消除方法

在钻井过程中,钻头切削岩层、钻柱与井壁的碰撞,必然造成钻井工具的振动,这些振动会在测斜加速度传感器的输出上得到反映,使其不能真实地反映井眼姿态的变化。为及时得到准确的井眼姿态,有必要研究振动条件下传感器的输出规律,进而消除振动的影响。从室内模拟振动实验的原始数据入手,通过Matlab对传感器输出信号进行功率谱密度估计,得出了振动频率与转速的大致关系,并设计了具有针对性的滤波器。通过对实验数据分析处理,振动干扰信号的能量得到大幅衰减,测斜传感器3个敏感轴的输出波动明显减小,提高了姿态测量的准确性,从而验证了该方法在旋转导向系统中是可行的。     

Hot air expansion of potato starch pellets with different water contents and salt concentrations

The expansion and puffing kinetics of commercial potato starch pellets were examined using a hot air fan oven in order to determine the puffing kinetics. The time for the onset of expansion showed uni-molecular type kinetic behaviour and was modelled by an Arrhenius plot. A pseudo-activation enthalpy for pellet expansion was also determined. The initial moisture content of the commercial pellets was controlled and the changes in the extent of puffing and the pseudo-activation enthalpy were found. The effect of type and quantity of cation in the formulation was then investigated. Expansion occurred even when no cation was added although the presence of cation did improve pellet expansion. The ratio of the native and pre-gelatinized starch in the pellets was also varied and showed to have limited effect on the extent of expansion. The puffing mechanism is discussed in light of these observations.     

A theory-based approach to teaching young children about health: A recipe for understanding.

The theory–theory account of conceptual development posits that children's concepts are integrated into theories. Concept-learning studies have documented the central role that theories play in children's learning of experimenter-defined categories but have yet to extensively examine complex, real-world concepts, such as health. The present study examined whether providing young children with coherent and causally related information in a theory-based lesson would facilitate their learning about the concept of health. This study used a pretest/lesson/posttest design, plus a 5-month follow-up. Children were randomly assigned to 1 of 3 conditions: theory (i.e., 20 children received a theory-based lesson), nontheory (i.e., 20 children received a nontheory-based lesson), and control (i.e., 20 children received no lesson). Overall, the results showed that children in the theory condition had a more accurate conception of health than children in the nontheory and control conditions, suggesting the importance of theories in children's learning of complex, real-world concepts. (PsycINFO Database Record (c) 2011 APA, all rights reserved)