Determination of Partial Factors of Breast Wall on Top of Sloping Breakwater

By applying the theory of structural reliability, reliability analyses for the stability of a breast wall on the top of a sloping breakwater are carried out. Based on the analyses, the method for determining partial action / load factors and partial resistance factors of breast walls is expounded, and the design expressions with partial factors are given. The values of partial action / load factors and partial resistance factors are recommended preliminarily according to the computation for breast walls with typical cross-sections.

Calibrating partial factors for Danish railway embankments using probabilistic analyses

High costs are connected with upgrading railway embankments throughout Denmark using the partial factors for geotechnical design calibrated for general application. One way to reduce the costs is reliability-based calibration of the partial factors to a reasonable safety level taking into account the specific design situations and uncertainties relevant to railway embankments. A reliability-based design has been investigated, resulting in an optimal partial factor for the considered subsoil. With a stochastic soil model to simulate the undrained shear strength of soft soil deposits, the partial factor is calibrated using asymptotic sampling for the reliability assessment. The calibration shows that the partial factor can be reduced significantly compared to the value specified in the Danish National Annex to DS/EN 1997-1 （2007）, Eurocode 7.

Risk factors of renal artery pseudoaneurysm following partial nephrectomy

Objective To study the risk factors of renal artery pseudoaneurysm ( RAP) following partial nephrectomy. Methods Open partial nephrectomhy was performed on a total of 464 cases of renal cell cancer from July 2003 to May 2010. Five patients ( 1. 1% ) had postoperative hem-

PARTIAL PURIFICATION AND CHARACTERIZATION OF AN AUTOCRINE T SUPPRESSOR FACTOR FROM MURINE LEUKEMIA

The leukemia-associated autoinhibitor (LAI-615) derived from murine leukemia L7811 has been investigated intensively in our laboratory. In the following experiments, the partial purification of LA I-615 has been carried out in addition to the observation of phenotype variations of L7811 leuke-mic cells. The factor was purified over 1306-fold by sequential fractionation with Sephadex G-150 gel filtration, DEAE-cellulose ion exchange chromato-graphy, and Mono Q-fast protein liquid chromato-graphy. The molecular weight of LAI-615 was 68,000 as estimated by gel filtration. LAI-615 was a protein but not glycosylated, and it was suggested LAI-615 be secreted in an autocrine manner. Im-munocytochemical staining showed that the expression of Lyt2 phenotype of L7811 leukemic cells was often coincident with the secretion of LAI-615. Moreover, the physicochemical characteristics of LAI-615 was similar to that of T suppressor factor. Thus it is concluded that LAI-615 may be one of TsF-like factors.

Synthesis and Flocculation of Polyacrylamide with Low Water Absorption for Non-dispersible Underwater Concrete

The polyacrylamide which is directly added into concrete shows strong water absorption property.Thus the construction of underwater constructure would demand high amount of water,resulting in poor workability of concrete and strength shrinkage after hardening.Herein,a kind of anionic polyacrylamide(APAM)grafted with water reducing functional group(-COOH)was synthesized at low temperatures by partial factor design and response surface design.The structure and morphology of APAM were characterized by UV,FTIR and SEM methods.The experimental results show that the molecular weight of the synthesized APAM could reach 11 million,under the condition that the temperature was 35℃,the pH value was 8,the monomer concentration was 27wt%,the initiator dosage was 0.6wt%,and the monomer ratio(n(AM):n(AA))was 3.When the APAM was applied into the underwater slurry,it presented good flocculation and low water demand.When the dosage was 1%of the mass of the cement,the water demand increased by 12%,which could meet the self-leveling and anti-dispersity of the underwater slurry at the same time.This technology provides technical guidance for the large-scale industrial production of polyacrylamide for underwater concrete construction while achieving environmental protection during production.

Effects of deep vertical rotary tillage on the grain yield and resource use efficiency of winter wheat in the Huang-Huai-Hai Plain of China

Tillage represents an important practice that is used to dynamically regulate soil properties,and affects the grain production process and resource use efficiency of crops.The objectives of this 3-year field study carried out in the Huang-Huai-Hai(HHH) Plain of China were to compare the effects of a new deep vertical rotary tillage (DVRT) with the conventional shallow rotary tillage (CT) on soil properties,winter wheat (Triticum aestivum L.) grain yield and water and nitrogen use efficiency at different productivity levels,and to identify a comprehensive management that optimizes both grain yield and resource use efficiency in the HHH Plain.A split-plot design was adopted in field experiments in the winter wheat growing seasons of 2016–2017 (S1),2017–2018 (S2) and 2018–2019 (S3),with DVRT (conducted once in June 2016) and CT performed in the main plots.Subplots were treated with one of four targeted productivity level treatments (SH,the super high productivity level;HH,the high productivity and high efficiency productivity level;FP,the farmer productivity level;ISP,the inherent soil productivity level).The results showed that the soil bulk density was reduced and the soil water content at the anthesis stage was increased in all three years,which were due to the significant effects of DVRT.Compared with CT,grain yields,partial factor productivity of nitrogen (PFP_(N)),and water use efficiency (WUE) under DVRT were increased by 22.0,14.5 and 19.0%.Path analysis and direct correlation decomposition uncovered that grain yield variation of winter wheat was mostly contributed by the spike numbers per area under different tillage modes.General line model analysis revealed that tillage mode played a significant role on grain yield,PFP_(N) and WUE not only as a single factor,but also along with other factors(year and productivity level) in interaction manners.In addition,PFP_(N) and WUE were the highest in HH under DVRT in all three growth seasons.These results provided a theoretical basis and technical support for coordinating the high yield with high resource use efficiency of winter wheat in the resource-restricted region in the HHH Plain of China.

Statistical analysis of nitrogen use efficiency in Northeast China using multiple linear regression and Random Forest

Understanding the spatial-temporal dynamics of crop nitrogen(N)use efficiency(NUE)and the relationship with explanatory environmental variables can support land-use management and policymaking.Nevertheless,the application of statistical models for evaluating the explanatory variables of space-time variation in crop NUE is still under-researched.In this study,stepwise multiple linear regression(SMLR)and Random Forest(RF)were used to evaluate the spatial and temporal variation of NUE indicators(i.e.,partial factor productivity of N(PFPN);partial nutrient balance of N(PNBN))at county scale in Northeast China(Heilongjiang,Liaoning and Jilin provinces)from 1990 to 2015.Explanatory variables included agricultural management practices,topography,climate,economy,soil and crop types.Results revealed that the PFPN was higher in the northern parts and lower in the center of the Northeast China and PNBN increased from southern to northern parts during the 1990–2015 period.The NUE indicators decreased with time in most counties during the study period.The model efficiency coefficients of the SMLR and RF models were 0.44 and 0.84 for PFPN,and 0.67 and 0.89 for PNBN,respectively.The RF model had higher relative importance of soil and climatic covariates and lower relative importance of crop covariates compared to the SMLR model.The planting area index of vegetables and beans,soil clay content,saturated water content,enhanced vegetation index in November&December,soil bulk density,and annual minimum temperature were the main explanatory variables for both NUE indicators.This is the first study to show the quantitative relative importance of explanatory variables for NUE at a county level in Northeast China using RF and SMLR.This novel study gives reference measurements to improve crop NUE which is one of the most effective means of managing N for sustainable development,ensuring food security,alleviating environmental degradation and increasing farmer’s profitability.

Optimization of water and nitrogen management for surge-root irrigated apple trees in the Loess Plateau of China

The Loess Plateau is one of the main regions for growing apple trees in China, but a shortage of water resources and low utilization of nitrogen have restricted its agricultural development. A 2-year field experiment was conducted which included three levels of soil water content(SWC), 90–75%, 75–60%, and 60–45% of field capacity, and five levels of nitrogen application(N(app)), 0.7, 0.6, 0.5, 0.4 and 0.3 kg/plant. The treatments were arranged in a strip-plot design with complete randomized blocks with three replications. For both years, the water and N(app) had significant(P<0.05) effects on leaf area index(LAI), yield, water use efficiency(WUE) and nitrogen partial factor productivity(NPFP) while the interaction effect of water and N(app) on yield, WUE and NPFP was significant(P<0.05) in 2018, and not in 2017. For the same SWC level, WUE first increased, then decreased as N(app) increased, while NPFP tended to decrease, but the trend of LAI with different N(app) was closely related to SWC. At the same N(app), the LAI increased as SWC increased, while the WUE and NPFP first increased, then decreased, but the yield showed different trends as the SWC increased. The dualistic and quadric regression equations of water and N(app) indicate that the yield, WUE and NPFP cannot reach the maximum at the same time. Considering the coupling effects of water and N(app) on yield, WUE and NPFP in 2017 and 2018, the SWC level shall be controlled in 75–60% of field capacity and the N(app) is 0.45 kg/plant, which can be as the suitable strategy of water and N(app) management for the maximum comprehensive benefits of yield, WUE and NPFP for apple trees in the Loess Plateau and other regions with similar environments.

Varied previous crops on improving oilseed flax productivity in semiarid Loess Plateau in China

To investigate the effects of crop rotation on oilseed flax growth and yield,three season experiments were carried out in semi-arid area of Dingxi,Gansu from 2017 to 2019.The designed 6 rotational systems were FFF(flax-flaxflax),PFF(potato-flax-flax),WPF(wheat-potato-flax),FPF(flax-potato-flax),PWF(potato-wheat-flax)and FWF(flax-wheat-flax).Flax growth and yield investigation results showed that crop rotation increased leaf area duration,dry matter accumulation,seed nitrogen accumulation,water and nitrogen used efficiency,compared with continuous cropping of flax.Flaxseed yields in rotation systems were 22.23%–44.11%greater than those of continuous cropping system.Those in wheat and potato stubbles had higher tiller number(21.43%and 29.46%),more branches(14.24%and 6.97%),effective capsules(26.35%and 28.79%),higher water use efficiency(40.26%and 33.5%),higher nitrogen partial factor productivity(33.85%and 31.46%)and dry matter(41.98%and 25.47%)than those in oilseed flax stubble.It concluded that crop rotation system was an effective measure for oilseed flax productivity in semi-arid area by improving yield components and promoting biomass.

Economically Optimal Rates and Nutrients Use Efficiency Indices of Maize to the Application of Different Rates of Nutrients in Central Rift Valley of Ethiopia

The use of balanced fertilizers in adequate amount is very important to increase crop productivity and production in Ethiopia. The study was executed to quantify maize (Zea mays L.) grain yield response to different rates of nitrogen (N), phosphorus (P), potassium (K) and sulfur (S) under balanced fertilization of other nutrients. On farm trials were conducted at seven sites on 8 farmers’ fields in Negele Arsi districts, west Arsi zone of Oromia region for three consecutive cropping seasons (2014-2016). Six rates of N, P, S and eight rates of K treatments established separately for each nutrient were laid out in randomized complete block (RCB) design with three replicates per farm. Nutrient response function modelling showed that 184, 20 and 80 kg•ha−1 were the agronomic optimum rate for N, P, and K, respectively. Mean agronomic efficiency (AE) of N, P and K were recorded at the lower rates of these nutrients, application of 46, 10 and 20 kg•ha−1 N, P and K resulted in 19.1, 61.0, and 24 kg additional grain yield•kg−1 N, P and K, respectively. Also, the mean partial factor productivity (PFP) of N, P and K were 77.6, 370 and 158 kg additional grain•kg−1 applied N, P and K respectively. Economically optimal rate (EOR) of N, P and K were 48 - 114 kg•ha−1 N with CP 8 - 3.5, 12 - 20 kg•ha−1 P with CP 18 - 4.5 and 32 - 53 kg•ha−1 K with CP 8-4, from these rates net returns of US$487.23 - 143.30, US$698.16 - 498.3 and US$359.31 - 193.63 could be obtained respectively. To conclude, application of 84, 12 and 40 kg•ha−1 N, P and K could be recommended for the production of maize.

Determination of Partial Safety Coefficients of Structural Reliability Based on Contaminated Distribution

Partial safety factors must be evaluated precisely for the given target reliability index to ensure the certain level of structural reliability due to uncertain factors.The current studies of partial safety factors do not consider human error in construction for structural reliability.A mathematically model should be improved to simulate the partial safety coefficient concerned uncertainty factors which concern the effect of human error in construction.We employ the contaminated distribution to obtain the realistic mean value and standard variance of variable of structural parameters which coexist with random error human error.The reasonable partial safety coefficient can be calculated based on the realistic value of structural parameters concerned the effects of random error and gross error.

A Finite Method for Computing the Drazin and Core-EP Inverses of Matrices Based on Partial Full-Rank Factorization

This paper presents a formula for the Drazin inverses of matrices based on a sequence of partial full-rank factorizations which theoretically extends the classic full-rank factorization method for computing the Drazin inverses established by R.E.Cline.The result is then extended to the core-EP inverses.

Performance of reliability-based design formats in geotechnical applications

Geotechnical design codes and guidelines are all switching from traditional factor of safety design to modern load and resistance factor design(LRFD)or partial factor design(PFD),in the belief that the latter two bring more flexibility and reliability consistency across various design scenarios,thus produce safe and cost-effective design outcomes.This paper first reviews the LRFD and PFD developed for geotechnical applications.A total of seven methods to calibrate the load and resistance factors are also introduced.The ability of the LRFD and PFD to produce designs with consistent reliability is examined and compared to that of a traditional factor of safety method using two examples of the bearing capacity of strip footings and the global stability of soil nail walls.Results showed that the framework of LRFD offers no apparent advantages over working stress design(WSD)in achieving more consistent reliability for geotechnical structures;the dispersion in design probabilities of failure could be five to seven orders of magnitude difference.The variation will be reduced to three orders if using the PFD.Neither reducing the variability in soil shear strength parameters nor allocating partial resistance factors with respect to soil types would efficiently harmonize the reliability levels when dealing with multiple soil layer conditions.In addition,the uniformity of reliability levels is insensitive to calibrations with or without presetting the load factors.This study provides insights into the LRFD and PFD frameworks currently developed for geotechnical applications.

Optimizing Nitrogen Use Efficiency for No-Till Corn Production by Improving Root Growth and Capturing NO_(3)-N in Subsoil

Subsoil acidity restricts root growth and reduces crop yields in many parts of the world. More than half of the fertilizer nitrogen(N) applied in crop production is currently lost to the environment. This study aimed to investigate the effect of gypsum application on the efficiency of N fertilizer in no-till corn(Zea mays L.) production in southern Brazil. A field experiment examined the effects of surface-applied gypsum(0, 5, 10, and 15 Mg ha^(-1)) and top-dressed ammonium nitrate(NH_4NO_3)(60, 120, and 180 kg N ha^(-1)) on corn root length, N uptake, and grain yield. A greenhouse experiment was conducted using undisturbed soil columns collected from the field experiment site to evaluate NO_3-N leaching, N uptake, and root length with surface-applied gypsum(0 and 10 Mg ha^(-1)) and top-dressed NH_4NO_3(0 and 180 kg N ha^(-1)). Amelioration of subsoil acidity due to gypsum application increased corn root growth,N uptake, grain yield, and N use efficiency. Applying gypsum to the soil surface increased corn grain yield by 19%–38% and partial factor productivity of N(PFPN) by 27%–38%, depending on the N application rate. Results of the undisturbed soil column greenhouse experiment showed that improvement of N use efficiency by gypsum application was due to the higher N uptake from NO_3-N in the subsoil as a result of increased corn root length. Our results suggest that ameliorating subsoil acidity with gypsum in a no-till corn system could increase N use efficiency, improve grain yield, and reduce environmental risks due to NO_3-N leaching.

Yield-scaled nitrous oxide emissions from nitrogen-fertilized croplands in China: A meta-analysis of contrasting mitigation scenarios

Nitrogen(N) losses in cropland resulting from the application of synthetic fertilizers decrease crop productivity and exacerbate environmental pollution.Mitigation measures, such as reduction in N fertilizer application rates, can have unintentional adverse effects on crop yield. We conducted a meta-analysis of soil N_(2)O emissions from agricultural fields across China under contrasting mitigation scenarios as a novel approach to identify the most effective strategy for the mitigation of emissions of N_(2)O derived from N fertilizer use in China. Current standard agricultural practice was used as a baseline scenario(BS), and 12 potential mitigation scenarios(S1–S12) were derived from the available literature and comprised single and combinations of management scenarios that accounted for crop yield. Mitigation scenarios S6(nitrification inhibitor 3,4-dimethylpyrazole phosphate) and S11(20% reduction in N application rate plus nitrification inhibitor dicyandiamide) in maize, rice, and wheat crops led to an average 56.0% reduction in N_(2)O emissions at the national level, whereas scenario S4(nitrification inhibitor dicyandiamide) led to yield optimization, with a 14.0% increase for maize and 8.0% increase for rice as compared to the BS. Implementation of these most effective mitigation scenarios(S4, S6, and S11) might help China, as a signatory to the 2015 United Nations Framework Convention on Climate Change(Paris Agreement), to achieve a 30% reduction in N_(2)O emissions by 2030.

Comparing Operational Efficiency of Mobile Operators in Brazil, Russia, India and China

Using partial factor productivity and data envelopment analysis approaches, this study measures and compares the operational efficiency of the 10 dominant mobile operators in Brazil, Russia, India and China （BRIC） between 2002 and 2006. The results of data envelopment analysis indicate that the two leading Brazilian mobile operators, Vivo and TIM, are fully efficient throughout the entire period of study, however, Indian mobile operators are the least efficient among BRIC operators. Interestingly, the findings of this study verify that full operational efficiency can be achieved by operators with large revenues, such as China Unicorn, and by other, y with medium and small revenues, such as Hvo, TIM and Oi. Partial faetor productivity demonstrates that 3 of the 4 Brazilian mobile operators, Vivo, TIM and Oi, have remarkable productivity ratios, and that the state-owned operator, China Unicom, has the highest revenue per capital expenditure among BRIC operators. In contrast, Indian mobile operators ＇productivity ratios are generally low compared to other BRIC mobile carriers.