scholarly journals Traffic-related pollution history (1994–2014) determined using urban lake sediments from Nanjing, China

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0255395
Author(s):  
Gengyu Liu
Keyword(s):  
Sediment Cores ◽  
Annual Rainfall ◽  
Industrial Emissions ◽  
Pollution History ◽  
Remanent Magnetisation ◽  
Rate Of Increase ◽  
Nanjing City ◽  
Traffic Related Pollution ◽  
Stage 1 ◽  
Two Stages

With the development of urbanisation and the increasing number of modern vehicles, traffic contamination has become an important source of environmental pollution. Most previous studies have focused on using roadside soil or plants to determine the spatial pattern of traffic pollutants along roads and the factors that influence this pattern, whereas few studies have reconstructed pollution histories caused by traffic using suitable methods. In this study, two gravity cores were obtained from Qianhu Lake, which is in the Zhongshan tourist area of Nanjing City and is distant from industrial areas. An accurate chronological framework covering the period from 1994 to 2014 was established using the correlation between the variation in grain size of the sediment cores and the variation in annual rainfall in Nanjing City. Moreover, magnetic and chemical parameters were also measured, and the results demonstrated that concentration-related magnetic parameters exhibited different correlations with different heavy metal concentrations. These correlations were significantly positive for Zn, Pb, and Co; weakly positive for Ni; absent for Cr; and negative for V. Combined with statistical data on industrial emissions and private cars in Nanjing City since 1994, the observed variations in magnetic susceptibility, anhysteretic remanent magnetisation, saturation isothermal remanent magnetisation, Zn, Pb, and Co, were controlled by traffic activities in the tourist area but not by industry. Therefore, the variations in these parameters record the traffic pollution history of the study area. Combined with the obtained chronological framework, the traffic-related pollution history could be divided into two stages: 1) from 1994 to 2003, when traffic-related pollution became increasingly serious because of the exponential increase in the number of private cars and the prosperity of tourism; 2) from 2003 to 2014, when traffic-related pollution continuously increased but at a much slower rate than in stage 1. This slower rate of increase was probably related to the maximum carrying capacity of the tourist area and technological innovations in automobile manufacturing, as well as improvements in fuels.

scholarly journals Effect of 2CaO·SiO2 particles addition on dephosphorization behavior

2020 ◽  
Vol 39 (1) ◽  
pp. 219-227
Author(s):  
Aijun Deng ◽  
Yunjin Xia ◽  
Jie Li ◽  
Dingdong Fan
Keyword(s):  
Liquid Slag ◽  
Solid Phase ◽  
Solid Particles ◽  
Hot Metal ◽  
Liquid Silicate ◽  
Phase Complex ◽  
Dephosphorization Slag ◽  
Stage 1 ◽  
Two Stages ◽  
Complex Liquid

AbstractThe effect of the addition of 2CaO·SiO2 solid particles on dephosphorization behavior in carbon-saturated hot metal was investigated. The research results showed that the addition of 2CaO·SiO2 particles have little influence on desilication and demanganization, and the removal of [Si] and [Mn] occurred in the first 5 min with different conditions where the contents of 2CaO·SiO2 particles addition for the conditions 1, 2, 3, 4, and 5 are 0, 2.2, 6.4, 8.6, and 13.0 g, respectively. The final dephosphorization ratios for the conditions 1, 2, 3, 4, and 5 are 61.2%, 66.9%, 79.6%, 63.0%, and 78.1%, respectively. The dephosphorization ratio decreases with the increase of 2CaO·SiO2 particles in the first 3 min. The reason for this is that the dephosphorization process between hot metal and slag containing C2S phase consisted of two stages: Stage 1, [P] transfers from hot metal to liquid slag and Stage 2, the dephosphorization production (3CaO·P2O5) in liquid slag reacts with 2CaO·SiO2 to form C2S–C3P solid solution. The increase of 2CaO·SiO2 particles increases the viscosity of slag and weakens the dephosphorization ability of the stage 1. The SEM and XRD analyses show that the phase of dephosphorization slag with the addition of different 2CaO·SiO2 particles is composed of white RO phase, complex liquid silicate phase, and black solid phase (C2S or C2S–C3P). Because the contents of C2S–C3P and 2CaO·SiO2 in slag and the dephosphorization ability of the two stages are different, the dephosphorization ability with different conditions is different.

scholarly journals Archaeological studies In theIlmeny state reserve, South Urals

2020 ◽  
pp. 112-122
Author(s):  
V.S. Mosin
Keyword(s):  
Bronze Age ◽  
Iron Age ◽  
Early Iron Age ◽  
South Urals ◽  
Stone Age ◽  
Stage 1 ◽  
Two Stages

The paper describes two stages of archeological studies at the territory of the Ilmeny State Reserve. Stage 1 is related to expedition of L.Ya. Krizhevskaya in 1961–1970, which resulted in fn-ding of more than 40 settlements and sites of the Stone Age, Bronze Age and Early Iron Age. Seven settlements were excavated. Stage 2 studies began in 2010 and are continued at present. These works allowed us to fnd about 40 sites and settlements of the Stone Age and to excavate of the Stone Age sites and Bronze Ages burials.

Polycyclic Aromatic Hydrocarbons and Mercury in Sediments from Two Isolated Lakes in Central and Northern Canada

1993 ◽  
Vol 28 (8-9) ◽  
pp. 43-52 ◽  
Author(s):  
W. L. Lockhart ◽  
P. Wilkinson ◽  
B. N. Billeck ◽  
G. J. Brunskill ◽  
R. V. Hunt ◽  
...  
Keyword(s):  
Sediment Cores ◽  
Hudson Bay ◽  
Atmospheric Fallout ◽  
Long Period ◽  
The North ◽  
Northwestern Ontario ◽  
Forest Region ◽  
Rate Of Increase ◽  
Polycyclic Aromatic ◽  
Recent Sediments

Sediment cores were taken from two isolated Canadian lakes, a southern lake in the boreal forest region of northwestern Ontario and a northern one in the tundra on the west coast of Hudson Bay, for the purpose of comparing current and historical loadings of several contaminants. There are no sources of anthropogenic contaminants within either basin, yet both lakes showed increases in polycyclic aromatic hydrocarbon and mercury in more recent sediments as compared with older, deeper sediments. We have interpreted these as indications of increased loadings as a result of atmospheric fallout. When compared on the basis of the sum of sixteen PAHs, both lakes showed peak inputs in the middle years of this century, followed by more recent declines; although current values still exceed those from deep slices. With respect to mercury, the concentrations found in the southern lake were somewhat higher than those in the northern lake, and loadings were clearly greater in the south. Both lakes showed enrichment of mercury in top layers of the cores relative to bottom layers, and this enrichment was proportionately greater in the north. Both mercury profiles showed a slow rate of increase for a long period before 1850, suggesting influences from areas industrialized before North America. The northern lake also showed increases in PAH loadings prior to 1850, but the southern lake did not.

scholarly journals Apical Debris Extrusion by Adaptive Root Canal Instrumentation in Oval Canals: Full-Sequence SAF System vs. the XP-Endo Shaper Plus Sequence

2020 ◽  
Vol 10 (16) ◽  
pp. 5684 ◽  
Author(s):  
Ajinkya M. Pawar ◽  
Bhaggyashri A. Pawar ◽  
Anuj Bhardwaj ◽  
Alexander Maniangat Luke ◽  
Zvi Metzger ◽  
...  
Keyword(s):  
Root Canal ◽  
Significance Level ◽  
Full Sequence ◽  
Apical Extrusion ◽  
Significant Difference ◽  
Group A ◽  
Group B ◽  
Stage 1 ◽  
Two Stages ◽  
Root Canal Instrumentation

Apical extrusion of debris (AED) by the full sequence of the self-adjusting file (SAF) system was compared with that of the XP-endo shaper plus sequence. Sixty permanent mandibular incisors were randomly assigned to two groups (n = 30) for root canal instrumentation: Group A: Stage 1—pre-SAF OS, pre-SAF 1 and pre-SAF 2 files, followed by Stage 2—1.5 mm SAF; and Group B: Stage 1— hand K-file 15/0.02, followed by Stage 2—XP-endo shaper and Stage 3—XP-endo finisher. The AED produced during instrumentation at each stage was collected in pre-weighed Eppendorf tubes. The weights of AED by the two methods were compared using t tests with significance level set at 5%. Group A produced significantly less total AED than Group B (p < 0.001), with no significant difference in debris extrusion between the two stages (p = 0.3014). Conversely, in Group B, a significant difference was noted between Stage 1 and Stages 2 and 3 (p < 0.01), with no significant difference between Stages 2 and 3 (p = 0.488). Both sequences resulted in measurable amounts of AED. Each phase, in either procedure, made its own contribution to the extrusion of debris.

scholarly journals Qualitative Interviewing: Testing Health Surveys Among Vietnam War Veterans at the Age of 70 Years

SAGE Open ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 215824401983269
Author(s):  
April S. Fales ◽  
Yasmin S. Cypel ◽  
Marsha E. Dunn ◽  
Ann L. Truelove ◽  
Erick K. Ishii ◽  
...  
Keyword(s):  
Qualitative Research ◽  
Vietnam War ◽  
Questionnaire Development ◽  
Usability Testing ◽  
Cognitive Interviewing ◽  
Item Recall ◽  
Subject Recruitment ◽  
Vietnam Era ◽  
Stage 1 ◽  
Two Stages

The Vietnam Era Health Retrospective Observational Study (VE-HEROeS) is a nationwide study designed to compare the health of U.S. Vietnam era veterans to age- and sex-matched U.S. residents. Two self-administered mail questionnaires, one for veterans and the other for the U.S. nonmilitary population, were developed using already validated and newly developed items. A pretest was conducted to evaluate item recall and comprehension, new-item response validity, and the overall survey experience (usability of survey materials including the screener questionnaire for nonveterans). Subject recruitment was completed using convenience sampling and a $50 incentive. Cognitive interviewing and usability interviewing, two qualitative research methods, were implemented. Interviews were conducted in two stages (Stage 1, cognitive interviewing, n = 12; Stage 2, usability testing, n = 8) by three experienced methodologists. Concurrent probing techniques, unscripted probes, and retroactive probing were used to elicit response from 14 veterans and six nonveterans (mostly male, White, and aged 65-70 years). Information about the overall survey process was also obtained through observation during usability testing. Results signify that qualitative research is an important part of questionnaire development targeting older veterans due to issues involving comprehension, interpretability, and recall.

Efficient two-stage sequential arrays of proof of concept studies for pharmaceutical portfolios

2020 ◽  
pp. 096228022095817
Author(s):  
Linchen He ◽  
Linqiu Du ◽  
Zoran Antonijevic ◽  
Martin Posch ◽  
Valeriy R Korostyshevskiy ◽  
...  
Keyword(s):  
Cost Effectiveness ◽  
Cost Benefit ◽  
Cost Effective ◽  
Cost Ratio ◽  
Proof Of Concept ◽  
Type Iii ◽  
Benefit Cost Ratio ◽  
Stage 1 ◽  
Two Stages ◽  
Benefit Cost

Previous work has shown that individual randomized “proof-of-concept” (PoC) studies may be designed to maximize cost-effectiveness, subject to an overall PoC budget constraint. Maximizing cost-effectiveness has also been considered for arrays of simultaneously executed PoC studies. Defining Type III error as the opportunity cost of not performing a PoC study, we evaluate the common pharmaceutical practice of allocating PoC study funds in two stages. Stage 1, or the first wave of PoC studies, screens drugs to identify those to be permitted additional PoC studies in Stage 2. We investigate if this strategy significantly improves efficiency, despite slowing development. We quantify the benefit, cost, benefit-cost ratio, and Type III error given the number of Stage 1 PoC studies. Relative to a single stage PoC strategy, significant cost-effective gains are seen when at least one of the drugs has a low probability of success (10%) and especially when there are either few drugs (2) with a large number of indications allowed per drug (10) or a large portfolio of drugs (4). In these cases, the recommended number of Stage 1 PoC studies ranges from 2 to 4, tracking approximately with an inflection point in the minimization curve of Type III error.

scholarly journals Determining Ergonomic Smartphone Forms With High Grip Comfort and Attractive Design

2018 ◽  
Vol 61 (1) ◽  
pp. 90-104 ◽  
Author(s):  
Songil Lee ◽  
Gyouhyung Kyung ◽  
Jihhyeon Yi ◽  
Donghee Choi ◽  
Sungryul Park ◽  
...  
Keyword(s):  
Potential Effect ◽  
Hand Length ◽  
Stage 1 ◽  
Two Stages

Objective: The authors aimed to identify ergonomic smartphone forms by investigating the effects of hand length, four major smartphone dimensions (height, width, thickness, and edge roundness), and smartphone mass on grip comfort and design attractiveness. Background: Despite their potential effect on grip comfort and design attractiveness, the dimensions specified above have never been simultaneously considered in a study investigating smartphone gripping. Method: Seventy-two young individuals participated in a three-stage study. Stage 1 determined the ranges of the four smartphone dimensions suitable for grip comfort and identified the strengths of their influences. Stage 2 investigated the effects of width and thickness (determined to have the greatest influence) on grip comfort and design attractiveness. Mock-ups of varying masses were fabricated using the dimensions determined during the first two stages to investigate the effect of mass on grip comfort and design attractiveness in Stage 3. Results: Phone width was found to significantly influence grip comfort and design attractiveness, and the dimensions of 140 × 65 (or 70) × 8 × 2.5 mm (height × width × thickness × edge roundness) provided high grip comfort and design attractiveness. The selected dimensions were fit with a mass of 122 g, with masses in the range of 106–137 g being comparable. Conclusion: The findings of this study contribute to ergonomic smartphone design developments by specifying dimensions and mass that provide high grip comfort and design attractiveness. Application: The dimensions and mass determined in this study should be considered for improving smartphone design grip comfort and attractiveness.

The effect of temperature and moisture on the Immature Stages of Aphodius tasmaniae Hope (Scarabaeidae) in the lower South-east of South Australia.

1961 ◽  
Vol 9 (2) ◽  
pp. 173 ◽  
Author(s):  
DA Maelzer
Keyword(s):  
Mortality Rate ◽  
Water Content ◽  
South Australia ◽  
Effect Of Temperature ◽  
Annual Rainfall ◽  
Field Observations ◽  
Immature Stages ◽  
Rate Of Increase ◽  
Lower South ◽  
Third Instar Larvae

The distribution and abundance of the univoltine species A. tasmaniae in the lower south-east of South Australia appears to be related to annual rainfall. The effects of moisture on the mortality rates of the immature stages were consequently studied and observations were made of the effects of variations in moisture in the field. Laboratory experiments and field observations suggested that variations in soil moisture have little effect on the eggs and the diapausing prepupae in the field. Eggs absorbed water and hatched normally within a pF range of 2.50-3.75 in a sand and in a clay loam. At pF 4.0 in both soils, eggs lost weight and did not hatch. The adults, however, tend to lay the eggs well within the pF range in which the eggs can develop, and soil samples suggested that eggs would develop with little mortality in the kinds of places in which they are usually laid. When prepupae enter diapause they have a water content of c. 77%. When desiccated in the laboratory, few prepupae died until their water content fell below 62%. The mortality rate then increased sharply, and it was estimated that 50% of the prepupae died when their water content dropped to 57%. Droughts of sufficient duration and intensity to kill 50% of the prepupae have never been recorded from the study area, and field observations suggested that few prepupae died of desiccation in summer. Unlike the two stages above, the first and third instar larvae may be markedly affected by variations in moisture in the field. The first instar larvae, after hatching, do not move to the surface of the soil and do not feed much until the soil is saturated with rain. As rainfall is variable at this time of the year, the larvae may be in dry soil for many weeks before they are stimulated to extend their burrows to the surface and search for food. Many larvae may die of starvation during this time, and the mortality rate of the larvae was related empirically to the length of the autumn "drought". Third instar larvae may be affected, on the other hand, by excessive water. In wet winters, vast numbers of larvae are drowned when extensive flooding occurs on the poorly-drained soils, and on well-drained soils a large proportion of larvae are killed by the entomophagous fungus Cordyceps aphodii. The above data have suggested that moisture is one of the major factors affecting the distribution and abundance of the species. Temperature has little effect on the rate of increase of the species.

Comparative Study of Fuzzy Entropy with Relative Spike Amplitude Features for Recognizing Wake-Sleep Stage 1 EEGs

2015 ◽  
Vol 4 (2) ◽  
pp. 12-25 ◽  
Author(s):  
Natarajan Sriraam ◽  
B. R. Purnima ◽  
Uma Maheswari Krishnaswamy
Keyword(s):  
Comparative Study ◽  
Sleep Stage ◽  
Research Work ◽  
Fuzzy Entropy ◽  
Elman Neural Network ◽  
Gold Standard Method ◽  
Spike Amplitude ◽  
Stage 1 ◽  
Two Stages ◽  
Stage Analysis

Electroencephalogram (EEG) based sleep stage analysis considered to be the gold standard method for assessment of sleep architecture. Of importance, transition between the first two stages, wake-sleep stage 1 found to be reliable quantitative tool for drowsiness and fatigue detection. The selection of appropriate feature pattern for EEGs is a quite challenging task due to its non-linear and non-stationary nature of the EEG signals. This research work attempts to provide a comparative study of time influence of time domain feature, relative spike amplitude (RSA) with entropy feature, fuzzy entropy(FE) for recognizing the transition between wake and sleep stage 1. EEGs extracted from offline polysomnography database is used and the extracted RSA and FE wake-sleep stage 1 derived EEG features are further classified using a feedback recurrent Elman neural network (REN) classifier. EEGs are segmented into 1s pattern. Simulation of the REN classifier revealed that the FE feature with REN yields a CA of 99.6% compared to that of with RSA feature.

The Reformed Australian Child Support Scheme

1991 ◽  
Vol 12 (4) ◽  
pp. 430-449 ◽  
Author(s):  
MARGARET HARRISON
Keyword(s):  
Child Support ◽  
Australian Government ◽  
Court Order ◽  
Taxable Income ◽  
Australian Child ◽  
Number Of Children ◽  
Second Stage ◽  
Stage 1 ◽  
Two Stages ◽  
Payment Mechanisms

The Australian child support reforms were introduced in two stages between mid-1988 and late 1989. The first stage sought to increase the collection and payment of money due by reason of a court order, by establishing the Child Support Agency within the Taxation Office. This agency assumes responsibility for locating missing liable parents and, where possible, withdraws the amount owed from the salaries of liable parents. The second stage uses the collection and payment mechanisms established under Stage 1 and also assesses amounts due administratively by applying a formula that takes account of parental taxable income and the number of children for whom there is a support liability. Results of an evaluation of the first stage of the scheme are discussed. Although single-parent poverty will not be resolved by measures such as those initiated by the Australian government, the evidence is that amounts awarded under Stage 1 are higher than they were prior to the introduction of the reforms and that administrative assessment under Stage 2 is yielding higher amounts.

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