Sensitivity analysis of North American bird population estimates

The Partners in Flight North American Landbird Conservation Plan provided estimates of population sizes for 448 landbird species using a multiplicative model. Input parameters in this calculation included the area of state × Bird Conservation Region polygons, area-specific mean Breeding Bird Survey counts circa 1995, and adjustment factors for the distance over which species may presumably be correctly counted, the assumed pairing of singing males with non-singing females, and variability in the propensity of birds to sing over the course of the survey day. I assessed the sensitivity of this population calculation to changes in the input parameters. I assessed both local and global sensitivity of the model to changes in the parameters with Monte Carlo one-at-a-time simulations and the Fourier amplitude sensitivity test (FAST). Monte Carlo simulations were an estimate of local model sensitivity whereas FAST estimated global model sensitivity, accommodating the potential shared variance between model parameters. Monte Carlo simulations suggested population estimates were 39% more sensitive to changes in the detection distance adjustment than to the other parameters; the other parameters were nearly equal in their contribution to model sensitivity. Conversely, FAST analysis determined that each of the input variables aside from the pair adjustment provided roughly equal contributions to variability in population estimates. The most efficient means for improving continental population estimates for birds surveyed by the Breeding Bird Survey will be through increased scrutiny of the species-specific distance detection and time-of-day adjustments and improved understanding in the spatial and temporal variability in the mean Breeding Bird Survey count.     

石化企业VOCs无组织排放源强的反演模拟

针对石化行业面源无组织排放VOCs难以准确定量的问题,建立了基于开路式傅里叶变换红外光谱技术(OP-FTIR)的面源污染源源强反演模型,并进行了现场模拟试验。试验结果表明,风向、风速、大气稳定度、监测距离、数据处理周期等都是影响反演模型准确性的重要灵敏度参数。以反演源强Q_P与实际排放量Q的比值(Q_P/Q)为量化指标,对各影响因素进行优化处理,确定了构建反演模型适用的边界条件。当各灵敏度参数稳定于适用边界条件之内时,Q_P/Q为0.85~0.90。     

Use of thermal analysis techniques (TG-DSC) for the characterization of diverse organic municipal waste streams to predict biological stability prior to land application

The use of organic municipal wastes as soil amendments is an increasing practice that can divert significant amounts of waste from landfill, and provides a potential source of nutrients and organic matter to ameliorate degraded soils. Due to the high heterogeneity of organic municipal waste streams, it is difficult to rapidly and cost-effectively establish their suitability as soil amendments using a single method. Thermal analysis has been proposed as an evolving technique to assess the stability and composition of the organic matter present in these wastes. In this study, three different organic municipal waste streams (i.e., a municipal waste compost (MC), a composted sewage sludge (CS) and a thermally dried sewage sludge (TS)) were characterized using conventional and thermal methods. The conventional methods used to test organic matter stability included laboratory incubation with measurement of respired C, and spectroscopic methods to characterize chemical composition. Carbon mineralization was measured during a 90-day incubation, and samples before and after incubation were analyzed by chemical (elemental analysis) and spectroscopic (infrared and nuclear magnetic resonance) methods. Results were compared with those obtained by thermogravimetry (TG) and differential scanning calorimetry (DSC) techniques. Total amounts of CO₂ respired indicated that the organic matter in the TS was the least stable, while that in the CS was the most stable. This was confirmed by changes detected with the spectroscopic methods in the composition of the organic wastes due to C mineralization. Differences were especially pronounced for TS, which showed a remarkable loss of aliphatic and proteinaceous compounds during the incubation process. TG, and especially DSC analysis, clearly reflected these differences between the three organic wastes before and after the incubation. Furthermore, the calculated energy density, which represents the energy available per unit of organic matter, showed a strong correlation with cumulative respiration. Results obtained support the hypothesis of a potential link between the thermal and biological stability of the studied organic materials, and consequently the ability of thermal analysis to characterize the maturity of municipal organic wastes and composts.     

重庆城区大气颗粒物的元素、离子及物相组成研究

采用X－射线能谱（EDX），傅立叶红外光谱（FT－IR），X－射线衍射（XRI）对重庆市区大气颗粒污染物的元素组成，离子，物相组成进行顾研究，EDX检出了S，Cl,K,Ca,Ti,Cr,Mn,Fe,Cu,Se,Sr,Zr,Rb,Ga,Hg,Zn,Ni元素，FT－IR光谱发现主要存在SO4^2-,NH4^ 和NO3^-,XRD结果表明存在CaSO4.2H2O,α-SiO2,(NH4)2Ca(SO4)2.2H2O,(NH4)2SO4等4个主要物相以及Fe3O4,CaCO3等物相，初步讨论了重庆大气颗粒物的污染来源及其时间，空间分布。     

污水处理厂污泥水溶解性有机物的光谱特性分析

污泥水是污水处理厂污泥浓缩、稳定、脱水等环节产生的废水,具有污染物浓度高、成分复杂的特点.采用三维荧光光谱和红外光谱研究了污泥水中溶解性有机物(DOM)的光谱特性.污泥水荧光性DOM(FDOM)可利用平行因子分析划分为6个荧光组分,分别为类蛋白质组分C1(275/355 nm)、C4(235/350 nm)和C6(275/305 nm),及类腐殖酸组分C2(250,340/440nm)、C3(320/380 nm)和C5(250/465 nm).重力浓缩和机械浓缩污泥水中COD与所有类腐殖酸组分均正显著相关(P0.01),类蛋白质组分对其影响不大.离心脱水污泥水中组分C1、C4和C5含量明显上升.深度脱水污泥水中FDOM荧光峰位置和强度与其它污泥水存在显著差异,C3和C6分别较离心脱水污泥水升高15.63和7.30倍.与浓缩污泥水相比,离心脱水污泥水中多糖和腐殖酸吸收峰增强,而深度脱水污泥水中蛋白质大量释放,金属离子会与腐殖酸和蛋白质络合引起DOM结构变化.     

土壤胡敏素对铜离子的吸附作用及其机理研究

以暗棕壤为供试土壤,研究了不同溶液pH值、离子强度、接触时间、反应温度和初始铜离子(Cu~(2+))浓度条件下,胡敏素对Cu~(2+)的吸附作用;利用扫描电子显微镜(SEM)、X-射线能量色散谱(EDS)、傅立叶变换红外光谱(FTIR)和X-射线光电子能谱(XPS),对胡敏素/胡敏素-Cu~(2+)复合物的表面形貌、元素分布和官能团组成进行了分析;应用延展X-射线吸收精细结构谱(EXAFS),对吸附态Cu~(2+)的局域配位结构进行了表征.结果表明:胡敏素对Cu~(2+)的吸附量随pH值、接触时间、反应温度和Cu~(2+)浓度的增加而增加,但随离子强度的增加而下降;吸附动力学符合准二级动力学方程,而吸附等温线用Langmuir方程的拟合效果较好;吸附过程需要能量,是自发、吸热和自由度增加的缔合反应;吸附Cu~(2+)之后,胡敏素表面产生了团聚现象,表面羧基、羟基、吡啶氮和N—O基团参与了Cu~(2+)的吸附作用,同时吸附态Cu~(2+)是以内层配位形式与胡敏素表面的O/N和C原子结合.     

LS系列硫磺回收催化剂工业装置使用总结

对比总结了LS系列催化剂的使用情况，结果表明，在一级转化器均装填LS-931Al2O3基催化剂的前提下，二级转化器上部装填LS－971脱氧保护型催化剂，下部装填LS－811Al2O3催化剂后，与单纯使用LS－931催化剂相比，单器转化率由64．1％提高到70．1％，有机硫水解率由96％提高到接近100％，两项合计使装置总硫转化率由95．1％提高到96．2％，若与两个转化器全部使用LS－811催化剂相比，则装置总硫转化率可由94．49％提高到96．2％使用效果更加显著。     

On thresholds and environmental curve tensiometers

This paper considers distinctions between lognormal and mixture models. Emphasis is placed on two component mixtures where the lower valued subpopulation has a large mixing parameter. The density of this sort of mixture can be easily mistaken for a lognormal density. In order to compare such a mixture to a lognormal it is demonstrated that Galton's two parameter logmodel and Pearson's five parameternormal mixture are special, or limiting, cases of the same general mixture model. Consideration is given to the lognormal threshold parameter in order to devise a tool that can help distinguish mixtures from lognormals. Based on the threshold parameter, piloted procedures can help measure whether or not a curve is friable, in the sense that a brittle curve is better represented as a mixture than as a skewed lognormal. It is also shown that generalizations of Galton's product risk model can be represented interms of the threshold parameter Based on a tool called a curve tensiometer was designed to be applied as a graphical friability check in the ecological context of Fisher's classic Iris data and in the environmental context of a Santa Monica Bay fish consumption study.     

A spectral power analysis of driving behavior changes during the transition from nondistraction to distraction

Objective: This article investigated and compared frequency domain and time domain characteristics of drivers' behaviors before and after the start of distracted driving.

Method: Data from an existing naturalistic driving study were used. Fast Fourier transform (FFT) was applied for the frequency domain analysis to explore drivers' behavior pattern changes between nondistracted (prestarting of visual–manual task) and distracted (poststarting of visual–manual task) driving periods. Average relative spectral power in a low frequency range (0–0.5 Hz) and the standard deviation in a 10-s time window of vehicle control variables (i.e., lane offset, yaw rate, and acceleration) were calculated and further compared. Sensitivity analyses were also applied to examine the reliability of the time and frequency domain analyses.

Results: Results of the mixed model analyses from the time and frequency domain analyses all showed significant degradation in lateral control performance after engaging in visual–manual tasks while driving. Results of the sensitivity analyses suggested that the frequency domain analysis was less sensitive to the frequency bandwidth, whereas the time domain analysis was more sensitive to the time intervals selected for variation calculations. Different time interval selections can result in significantly different standard deviation values, whereas average spectral power analysis on yaw rate in both low and high frequency bandwidths showed consistent results, that higher variation values were observed during distracted driving when compared to nondistracted driving.

Conclusions: This study suggests that driver state detection needs to consider the behavior changes during the prestarting periods, instead of only focusing on periods with physical presence of distraction, such as cell phone use. Lateral control measures can be a better indicator of distraction detection than longitudinal controls. In addition, frequency domain analyses proved to be a more robust and consistent method in assessing driving performance compared to time domain analyses.     

Clove as antioxidant additive in diesel–biodiesel fuel blends in diesel engines

Increased NOx emission from usage of biodiesel is a burning issue to be dealt with. Many techniques have been adopted to reduce NOx emissions from diesel engines. The present experimental study deals with the analysis of performance and emission characteristics of Cotton Seed oil biodiesel with the addition of natural antioxidant extract of clove. FTIR analysis characterized the antioxidant by the presence of hydroxyl groups denoted by the corresponding wave number. The oxidation stability of the test samples was determined in terms of induction period by means of Rancimat test. The induction periods of the test fuel samples B100, B20, B20+CL1000, and B20+CL2000 were found to be 2.20 h, 2.73 h, 10.19 h, and 11.12 h, respectively. Thus, the addition of Clove antioxidant increased the oxidation stability of the biodiesel. Results show that the addition of antioxidant to biodiesel blend has increased the Brake Thermal Efficiency to a maximum of 4.71% and decreased the Brake Specific Fuel Consumption to a maximum of 6.25% at full-load conditions compared to Cotton Seed biodiesel blend. The addition of Clove extract antioxidant at a concentration of 1000 ppm and 2000 ppm decreases the NOx emission by 23.03% and 26.7%, respectively, at full-load conditions. However, CO emissions increased by 1.12% and 4.49% with the addition of CL1000 and CL2000 to B20, respectively. Similarly, HC emissions increased by 4.19% and 7.35% by the addition of CL1000 and CL2000 to B20, respectively. The increases in smoke with the addition of CL1000 and CL2000 to B20 were 42.48% and 47.71%, respectively.