Corrosion and wear properties of in situ(TiB+TiC)/TA15 composites with a high volume percentage of reinforcement

The in situ(TiC+TiB)/TA15 composites with different volume percentages of reinforcement(10%,15%,20%and 25%)were prepared by water-cooled copper crucible vacuum suspension melting technology.The structures and compositions of the TA15 alloy and its composites were analyzed by XRD and EDS,and their electrochemical corrosion behaviors in the 3.5%NaCl solution were studied.Corrosion wear testing was conducted using a reciprocating ball-on-disc wear tester under a 10 N load.Results show that the in situ fibrous TiB phase and the granular TiC phase are uniformly distributed on the composite matrix.The microhardness can reach up to 531 HV as 25vol.%TiC+TiB reinforcement is added.Compared with the TA15 alloy,the volume wear rate decreases from(2.21±0.07)×10^(-4)to(1.75±0.07)×10^(-4)mm^(3)·N^(-1)·m^(-1)by adding 15vol.%TiC+TiB reinforcement,and the wear mechanism is adhesive wear.When the volume percentage of the reinforcement phase reaches 25%,the volume wear rate increases from(1.75±0.07)×10^(-4)to(2.41±0.07)×10^(-4)mm^(3)·N^(-1)·m^(-1),and the wear mechanism changes into abrasive wear.The volume loss resulted by the interaction between corrosion and wear accounts for more than 27%of the total wear volume.The volume loss due to wear-induced corrosion changes from 1.94%to 4.06%with different additions of reinforcement.The volume loss caused by corrosion-induced wear initially increases from 24.08%to 26.90%as the reinforcement increases from 0 to 15%due to the increase of corrosion potential,and then decreases from 26.90%to 25.68%as the reinforcement increases from 15%to 25%due to the peeling of TiC phase.

Comparison and Evaluation of Two Analytical Methods for Cation Exchange Capacity and Exchangeable Sodium Percentage of Five Soil Types in Central Sudan

Twenty-six soil samples were collected from five soil profiles at different climatological and ecological regions in central Sudan. Soil profile was dug in each studied area and morphological profile description was carried out for different horizons. All samples were analyzed using two different methods to determine Cation Exchange Capacity (CEC) and exchangeable sodium percentage (ESP). Statistical analysis (T-test) was used in order to investigate the differences between soil samples for the studied locations. Significant differences appeared when compared the two methods for CEC determination at Gedaref area, Wad Medani and Nile flood plain and that appeared in evaluation of ESP at Nile flood plain and Shambat area. The results also revealed that, the developed method used in this study was more practical, simple and reliable for determination of CEC and ESP as the currently used in most soil laboratories. In addition, it will be safer than the other methods in some problematic soils. The adoption of this developed method is advisable because it is less time consuming as it omits the washing step. In contrast, the old method cannot be a good substitute in laboratories which have no possibility to determine sodium by using flame photometer. We conclude that when the developed method is used to determine CEC and ESP time will be saved, that fewer amounts of chemicals will be used and that accurate results will be achieved.

Effect of Window Opening Percentage on the Air Flow Rate of Wind-Driven Natural Ventilation Rooms

According to the investigations of window opening percentage (WOP) of Shanghai in 2011, the WOP varies significantly from season to season and thus affects the air flow rate of natural ventilation rooms. A three-dimensional computional fluid dynamic(CFD) model was applied to simulating the flow fields in a street canyon under different wind speed and WOP. The numerical simulations show that WOP has a significant influence on the static pressure distribution of the downwind building. Therefore, a correction factor k can be used for calculating the flow rate of wind-driven natural ventilation. The results show that k ranges from 0.43 to 0.49 when WOP is 4.44%; when WOP increases to 9.78%, the correction factor k lies in 0.32 and 0.36.

Predicting Base Saturation Percentage by pH—A Case Study of Red Soil Series in South China

pH and base saturation percentage (BSP) are two basic indexes in identifying soil types in Chinese Soil Taxonomy. Some studies proved that there is significant correlation between BSP and pH, thus it could save the cost of laboratory work if we can infer BSP directly from pH. In this study, the measured values of BSP and pH of 162 and 232 horizon samples from 48 and 55 red soil series surveyed from 2009 to 2011 in Fujian and Guangdong respectively were adopted from Soil Series Database to set up the optimal correlation model between BSP and pH. The results showed that: 1) BSP ranged from 2.30% to 94.02% with a mean of 25.07%, while pH from 3.42 to 6.91 with a mean of 4.98 for the total soil samples. 2) There were significant differences in pH between different soil types (R2 were 0.624 for Ferralosols, 0.507 for Ferrosols, 0.515 for Argosols, and 0.456 for Cambosols, p 2 were 0.580 for Quaternary red clay, 0.434 for granite, 0.642 for sandstone, and 0.712 for basalt, p 2 were 0.623 for dryland, and 0.404 for forest land, p 0), their probability density curves were mainly in flat or normal curves (y = 6.84x2 &#8722;45.86x + 81.52, R2 = 0.494, p < 0.01).

Optimal Percentage of Reclaimed Asphalt Pavement in Central Plant Hot Recycling Mixture

For determining the optimal percentage of RAP material in central plant hot recycling, binder was recovered from RAP by means of Abson recovery method, and properties tests of mixed binders consisting of recovered asphalt and fresh asphalt at different ratios were performed. In addition, the performances of mixture with different percentages of RAP such as rutting resistance, anti-cracking, moisture susceptibility and fatigue resistance were tested. The binder test results showed that the high temperature performance was improved with the increase of the percentage of the RAP, while the low temperature performance was declined. When the percentage of the recovered binder was less than 30%, the mixed binder could match the technical standards for fresh asphalt. Tests on the mixtures showed that rutting resistance increased gradually as RAP percentage increased, while thermal anti-cracking at low temperature and fatigue properties declined. The effect of the percentage of RAP on moisture susceptibility was limited. It is indicated that low temperature performance and fatigue properties are important for selecting the optimal percentage of RAP. Based on data obtained from binders and mixtures, it is concluded that the maximum percentage of RAP is approximately 30% without the addition of rejuvenating agent.

Body Mass Index and Body Fat Percentage in Assessment of Obesity Prevalence in Saudi Adults

Objective To assess the obesity prevalence in Saudi adults according to the international standards of body mass index (BMI) and body fat percentage (BF%). Methods Five hundred and thirty healthy Saudi adults aged 18-72 years (mean 36.91±15.22 years) were enrolled in this study. Their body composition was assessed by bioelectrical impendence analysis with a commercially available body composition analyzer. Standard BMI and BF% values were used to define obesity. Results The prevalence of underweight, normal underweight, overweight and obesity in Saudi adults according to the BMI criteria (<18.5 kg/m 2 , 18.5-24.4 kg/m 2 , 25-29.9 kg/m 2 , 30 kg/m 2 and above, respectively) was 2.5%, 30.2%, 33.6%, and 33.8%, respectively, whereas the obesity prevalence was 60% (n=318) in Saudi adults according to the BF% criteria (25% for males and 30% for females), which was significantly higher than that according to BMI criteria. However, it was 50.6% (n=268) when the BMI cutoff point was 27.5 kg/m 2 , proposed by WHO for the Asian population. Kappa analysis showed that the obesity prevalence defined by BMI and BF% was higher in females than in males (k=0.530 vs k=0.418, P<0.0001). The sensitivity and specificity of BMI (30 kg/m 2 and 27.5 kg/m 2 ) were 54.1% and 96.7% and 76.4% and 88.2%, respectively, for obesity. A lower BMI cutoff point (26.60 kg/m 2 ) was proposed in this study, which gave the maximum sensitivity (84.3%) and specificity (85.4%), with a moderate kappa agreement (k=0.686). Moreover, the obesity prevalence at this cutoff point (56.4%) was significantly higher than that recommended by WHO. Conclusion The specificity of BMI for obesity is high and its sensitivity is low in both sexes. Its sensitivity can be increased by changing BMI cutoff to a lower value. The choice of BF% reference is of great influence for the assessment of obesity prevalence according to the BMI.

STUDY ON RELATIONSHIPS AMONG SEEDLING QUALITY AND SURVIVAL RATE, STOCKING PERCENTAGE AND GROWTH

Effects of various seedling classes and root cutting treatments on the survival rate, stocking Percentage and the growth of height and collar diameter in young stands of korean pine (Pinus koraiensis), mongolian scots pine (Pin us sylvestris var.mangolica),Dahurian larch (Larix gmelini), korean spruce (Picea koraiensis), anur cork tree(Phellodendron amurensis). manchurian ash (Fradinus mandshurica) and anur linden (Tilia amurensis) were studied in this paper. The results show that the survival rate, stocking Percentage and the growth of height and collar diameter of the I class seedlings are better than that of the n and III classes seedlings. so it is very important to select I class seedlings for increasing the quality of afforestation.

Effects of Ce and Impurities on Percentage Elongation and Recrystallization in Al-Li Alloys

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Percentage Change on FDG-PET/CT Predicts Complete Response to Neoadjuvant Radiochemotherapy in Esophageal Cancer

Objective: We evaluated whether the changes in FDG-PET/CT uptake between pre/and post-treatment might predict a complete response in esophageal cancer (EC). Patients and Methods: Fifty-six patients with 2 PET-CTs studies were evaluated retrospectively. Images were evaluated qualitatively and semiquantitatively (SUVs). Patients were classified as persistence of disease, complete metabolic response and unspecific FDG uptake. The SUVmax values and percentages of change in SUV were measured. Results: A significant difference was found between the persistence group and the non-persistence group regarding the median percentage change in SUVtumor (72.95% vs. 54.12%;p = 0.04) and regarding the percentage change in SUVnode (89.91% vs. 59.91%, p = 0.04). In patients treated with radiochemotherapy (RCTX), a significant difference was found between the persistence group and the no persistence group regarding the percentage change in SUVtumor (58.02% vs. 78.59%). Overall survival rate was related to the percentage of change in the SUVtumor. The group of ≥75% of change SUVtumor showed a median survival of 37.32 months (IC: 95% = 49.93 - 24.70) and the group of <75% of change SUVtumor showed a median survival of 18.39 months (IC: 95% = 25.14 - 11.65) (p = 0.04). In patients with metastatic relapse, a significant difference was found regarding the percentage change in SUVnode (94.63% vs. 74.09%). Conclusion: Our study provides evidence that the percentage change in the SUVmax is a predictor of the response to neoadjuvant treatment in patients with EC. When SUVmax decreases by 72.95% or more, the patient is likely a complete responder.

Effects of cooling rate on vermicular graphite percentage in a brake drum produced by onestep cored wire injection

In this research, a vermicular graphite cast iron brake drum was produced by cored wire injection in a one-step method. Silica sand and low-density alumina-silicate ceramic were used as molding materials in order to investigate the effect of cooling rate on percentage of vermicular graphite and mechanical properties of the brake drum casting. Several thermocouples were inserted into the casting in the desired positions to measure the temperature change. By means of one-step cored wire injection, the two residual concentrations of Mg and RE were effectively controlled in the ranges of 0.013%-0.017% and 0.019%-0.025%, respectively, which are crucial for the production of vermicular graphite cast iron and the formation of vermicular graphite. In addition, the cooling rate had a significant effect on the vermicular graphite percentage. In the case of the silica mold brake drum casting, there was an obvious difference in the cooling rate with the wall change, leading to a change in vermicular graphite percentage from 70.8% to 90%. In the low-density alumina-silicate ceramic mold casting, no obvious change in temperature was detected by the thermocouples and the percentage of the vermicular graphite was stable at 85%. Therefore, the vermicular graphite cast iron brake drum with a better combination of mechanical properties could be obtained.

Effects of different priming treatments and priming durations on germination percentage of parsley (Petroselinum crispum L.) seeds

The effects of different priming treatments and priming durations on germination percentage at different temperatures in parsley seeds were studied. The seeds were treated for 2, 4, 6 and 8 days with the PEG 6000 (–0.5 MPa, –1.0 MPa and –1.5 MPa), KNO3 (0.30 mol/L and 0.35 mol/L), Mannitol (0.50 mol/L and 0.60 mol/L) and hydropriming (12h, 24h, 36h and 48h) and unprimed (control). Germination studies were made at 5, 10, 15, 20 and 25°C. Percentage of germination at different temperatures was significantly affected by priming treatments. Hydropriming (12h, 24h and 36 h) and mannitol 0.60 mol/L at 2 day generally had the highest germination percentages. In general, the highest germination percentage with priming was determined at 10°C. It may be said that seed priming treatments increased seed germination percentage at both low and high temperatures. The highest germination percentages were observed in both hydropriming and mannitol treatments as compared with PEG and KNO3 treatments. The PEG and KNO3 (2 and 4 days) treatments were better than unprimed treatment in all of the temperatures.

Body Mass Index and Percentage Body Fat Determination in Cancer Patients

Body Mass Index (BMI) and Percentage Body Fat (%BF) values have been determined in cancer patients. In the study, 83 adult cancer patients were assessed of which 15 (18.1%) were males and 68 (81.9%) females. Body weight and height of individual patients were used in calculating their respective BMI values. The respective %BF values were determined taking into consideration of the age, gender and BMI. Maximum values of BMI (34.71 kg/m2) and %BF (46.37%) were obtained, for which they were females and the minimum values of BMI (12.08 kg/m2) and %BF (12.35%) respectively. The patient with the minimum %BF value was male and that of BMI was female. It was observed from the results that females have higher values of both BMI and %BF than their male counterparts. The study reveals higher rate of female cancer incidence than males.

Body mass index versus percentage body fat in Chinese, African-American and Caucasian postmenopausal women

Objective: The aim of the study was to investigate in postmenopausal women whether the relationship between percentage body fat (PBF) and body mass index (BMI) differs between Asians living in Beijing (BA) and African-Americans (AA), and Caucasians (Ca) living in New York City. Methods: Healthy postmenopausal women (231 BA; 113 AA, 95 Ca), aged 50-80 years, were studied. Weight, height and PBF by dual energy X-ray absorptiometry (DXA) were measured. The relationship between PBF and BMI was assessed by multiple regression analysis. Results: Race, reciprocal of BMI (1/BMI) and the interaction between race and 1/BMI were all significantly (P<0.05) related to PBF in this sample. The slope of the line relating 1/BMI to PBF was different for BA compared to AA (P=0.01) and Ca (P=0.003) while the slopes for AA and Ca were not different (P>0.05). At lower levels of BMI, Asians tended to have higher PBF comparable to AA and Ca, while at BMI >30 BA tended to have less PBF than the other groups. Conclusion: The relation between PBF and BMI in BA postmenopausal women differs from that of AA and Ca women in this sample.

Study on Exchangeable Cation Determining Base Saturation Percentage of Soil in South China

Base saturation percentage (BSP) is an important soil chemical index in soil fertility and soil taxonomy. However, it is still unclear what exchangeable cation dominates BSP of soil in south China. Therefore, in this study, the data of BSPs and exchangeable H+, Al3+, Ca2+, Mg2+, K+ and Na+ of 109 and 45 horizon samples of 50 and 28 soil species in red soil and yellow soil groups in the Database of Chinese Soil Species were used to explore further the characteristics of BSPs and exchangeable cations as well as the correlation between BSPs and exchangeable cations. The results showed that the concentrations of exchangeable cations in both red soil and yellow soil groups were in an order of Al3+ (4.55 ± 1.47 and 4.22 ± 1.2 cmol(+)/kg) > Ca2+ (0.32 ± 0.21 and 0.36 ± 0.24 cmol(+)/kg) > H+ (0.23 ± 0.13 and 0.19 ± 0.10 cmol(+)/kg) > K+ (0.16 ± 0.09 and 0.16 ± 0.11 cmol(+)/kg) > Mg2+ (0.13 ± 0.09 and 0.11 ± 0.08 cmol(+)/kg) > Na+ (0.08 ± 0.06 and 0.11 ± 0.06 cmol(+)/kg). For red soil group, Al3+ concentration was significantly higher than those of other exchangeable cations, Ca2+ and H+ concentrations were significantly higher than those of K+, Mg2+ and Na+;while for yellow soil group, Ca2+, H+ and K+ concentrations were significantly higher than those of Mg2+ and K+. BSP of red soil group was codetermined by Ca2+, Al3+, Mg2+ and Na+, with the contributions of 33.81%, 19.82% and 14.49%, respectively;while BSP of yellow soil group was codetermined by Al3+, Ca2+, Mg2+, K+ and Na+, with the contributions of 24.91%, 21.55%, 19.91% and 14.21%, respectively. A higher concentration of exchangeable cation does not mean the higher importance of the cation to soil BSP.

The Actual versus Preferred Retirement Ages(Percentage distribution)

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Stable major QTL on chromosomes A07 and A08 increase shelling percentage in peanut(Arachis hypogaea L.)

Peanut is a major oilseed and food legume.Shelling percentage(SP),closely associated with seed yield,is a trait whose improvement is a major goal of peanut breeding.In this study,a mapping population(Xuhua 13×Zhonghua 6)was used to map quantitative trait loci(QTL)controlling SP in four environments.Two stable major QTL for SP were mapped on both SSR-and SNP-based genetic maps.q SPA07.1 on chromosome A07 explained up to 31.7%of phenotypic variation,and q SPA08.2 on chromosome A08 explained up to 10.8%.Favorable alleles of q SPA07.1 and q SPA08.2 were derived from the female and male parents,respectively.Eight recombinant inbred lines(RILs)carrying both favorable alleles showed superiority in SP over the two parents in all environmental trials.A combination of the two favorable alleles using the linked markers was verified to increase SP by~5%in the RIL population and by~3%SP in diverse peanut cultivars.q SPA07.1 and q SPA08.2 were delimited to respectively a 0.73-Mb interval harboring 96 genes and a 3.93-Mb interval harboring 238 genes.Respectively five and eight genes with high expression in pods,including enzymes and transcription factors,were assigned as candidate genes for q SPA07.1 and q SPA08.2.These consistent major QTL provide an opportunity for fine mapping of genes controlling SP,and the linked markers may be useful for genetic improvement of SP in peanut.

Study on PEG6000 Treatment on Budding Percentage And Germination Rate of Allium Tuberosum Roxb.Seeds

Allium tuberosum Roxb is very popular for its function of stomach-strengthening,spirit-freshening,yang-warming and kidney essencereplenishing,however,its seeds appear to low bud,irregular sapling and other side effects,which result in low yield and poor quality.This paper analyzed effects of PEG6000 concentration on budding percentage in detail.It comes to conclusions that budding percentage of No.1 seed increases from 71% to 92% on the basis of 36 h treatment by 20% PEG6000 and 24 h water-drying,that of No.3 seed ranges from 30.4% to 53.4% on the basis of the same treatment by 10% PEG6000.

Effect of Gold Nanoparticle on Percentage Depth Dose of 18 MV X-Ray in MAGICA Polymer Gel Dosimeter

Radiation-sensitive polymer gels are among the most promising three-dimensional dose verification tools and tissue-like phantom developed to date. This study is an investigating of percentage depth dose enhancement within the gel medium with the use of conformal distribution gold nanoparticle as contrast agents by high atomic number material. In this work, the normoxic polymer gel dosimeter MAGICA tissue-equivalence was first theoretically verified using MCNPX Monte Carlo code and experimentally by percentage depth dose curves within the gel medium. Then gold nanoparticles (GNPs) of 50 nm diameter with different concentrations of 0.1 mM, 0.2 mM, and 0.4 mM were embedded in MAGICA gel and irradiated by 18 MV photon beam. Experimental results have shown dose increase of 10%, 2% and 4% in 0.1 mM, 0.2 mM and 0.4 mM concentrations, respectively. Simulation results had good agreement in the optimum concentration of 0.1 mM. The largest error between experimental and simulation results was equal to 9.28% stood for 0.4 mM concentration. The results showed that the optimum concentration of gold nanoparticles to achieve maximum absorbed dose in both experimental and simulation was 0.1 mM and so it can be used for clinical studies.

Complex Percentage Differential Relay

This paper introduces a new complex percentage differential relay for bus protection. It allows greater CT errors during the external fault and is still sensitive to the intemal fault with high fault resistance or out-flowing current.The CTs of the differential circuit of the new relay may have different transformation ratio, so the new relay can share CTs with other relays and don’t need special CTs only for differential protection. It may be applied in transformer differential protection as well.

Preparation of High Percentage α-Calcium Sulfate Hemihydrate via a Hydrothermal Method

α-calcium sulfate hemihydrate (α-HH) is known to be suitable for application as bone void filler. High percentage of α-HH is obviously needed for medical applications, especially for implantation. Three commercially available calcium sulfate dihydrates (DH, CaSO4·2H2O) with different sizes and surface morphologies were used as starting materials to synthesize high percentage α-HH via a hydrothermal method. The median particle sizes of the three types of DH were 946.7 μm, 162.4 μm and 62.4 μm, respectively. They were named as DH-L, DH-M and DH-S in this paper. The particle size distribution, morphology and phase composition of the raw materials were evaluated before synthesis. SEM results revealed that DH-L consisted of irregular large particles, while DH-M and DH-S were composed of plate-like particles with some small ones. High percentage HH can be obtained with proper synthesis parameters by hydrothermal method, specifically, 105 &deg;C/90 min for DH-L (achieving 98.8% HH), 105&deg;C/30 min for DH-M (achieving 96.7% HH) and 100&deg;C/45 min for DH-S (achieving 98.4% HH). All the synthesized HH were hexagonal columns, demonstrating that they were α-phase HH. The particle size and morphology of starting material (DH) have significant influences on not only the rate of phase transition but also the morphology of the synthesized α-HH. Calcium sulfate dihydrate cements were prepared by the synthesized α-HH. The highest compressive strength of calcium sulfate dihydrate cement was 17.2 MPa. The results show that the preparation of high percentage α-HH is feasible via a hydrothermal method and the process can be further scaled up to industrial scale production.