Relationship between Formation Water Rate,Equivalent Penetration Rate and Volume Flow Rate of Air in Air Drilling

Formation water invasion is the most troublesome problem associated with air drilling. However, it is not economical to apply mist drilling when only a small amount of water flows into wellbore from formation during air drilling. Formation water could be circulated out of the wellbore through increasing the gas injection rate. In this paper, the Angel model was modified by introducing Nikurade friction factor for the flow in coarse open holes and translating formation water rate into equivalent penetration rate. Thus the distribution of annular pressure and the relationship between minimum air injection rate and formation water rate were obtained. Real data verification indicated that the modified model is more accurate than the Angel model and can provide useful information for air drilling.

Effects of water intrusion and loading rate on mechanical properties of and crack propagation in coal–rock combinations

Tackling the problems of underground water storage in collieries in arid regions requires knowledge of the effect of water intrusion and loading rate on the mechanical properties of and crack development in coal–rock combinations. Fifty-four coal–rock combinations were prepared and split equally into groups containing different moisture contents(dry, natural moisture and saturated) to conduct acoustic emission testing under uniaxial compression with loading rates ranging from 0.1 mm/min to 0.6 mm/min. The results show that the peak stress and strength-softening modulus, elastic modulus, strain-softening modulus, and post-peak modulus partly decrease with increasing moisture content and loading rate. In contrast, peak strain increases with increasing moisture content and fluctuates with rising loading rate. More significantly, the relationship between stiffness and stress, combined with accumulated counts of acoustic emission, can be used to precisely predict all phases of crack propagation. This is helpful in studying the impact of moisture content and loading rate on crack propagation and accurately calculating mechanical properties. We also determined that the stress thresholds of crack closure, crack initiation, and crack damage do not vary with changes of moisture content and loading rate, constituting 15.22%, 32.20%, and 80.98% of peak stress, respectively. These outcomes assist in developing approaches to water storage in coal mines, determining the necessary width of waterproof coal–rock pillars, and methods of supporting water-enriched roadways, while also advances understanding the mechanical properties of coal–rock combinations and laws of crack propagation.

The critical rate of horizontal wells in bottom-water reservoirs with an impermeable barrier

Barrier impacts on water cut and critical rate of horizontal wells in bottom water-drive reservoirs have been recognized but not investigated quantitatively. Considering the existence of impermeable barriers in oil formations, this paper developed a horizontal well flow model and obtained mathematical equations for the critical rate when water cresting forms in bottom-water reservoirs. The result shows that the barrier increases the critical rate and delays water breakthrough. Further study of the barrier size and location shows that increases in the barrier size and the distance between the barrier and oil-water contact lead to higher critical rates. The critical rate gradually approaches a constant as the barrier size increases. The case study shows the method presented here can be used to predict the critical rate in a bottom-water reservoir and applied to investigate the water cresting behavior of horizontal wells.

Improvement of Water Use Efficiency in Winter Wheat byBreeding Lines with Low Rate of Water Loss of Excised-Leaves

A study was conducted with the objective of improvement of water use efficiency (WUE) and yield of winter wheat for Lowland Dryland Farming systems through a breeding approach. Various genotypes were screened in 1988 for rate of water loss of excised leaves (RWL) , followed by inter-crossing of diverse parents in 1993. Analysis of the relationship between RWL and yield components and plant traits demonstrated significant differences in RWL among genotypes. Under most circumstances, RWL was correlated negatively with yield and grain weight, and positively with plant height. The results demonstrated a basis for simultaneous selection for high yield and low RWL. It was found that genotypic rank varied with the duration of water loss. Correlation between RWL and yield was reduced by extended water loss duration. Analysis of the genetic variation and segregation of RWL of progenies and the effect of simultaneous screening for RWL and agronomic traits showed that good lines with improved yield and water use performance could be obtained.

Optimization of sowing date and seeding rate for high winter wheat yield based on pre-winter plant development and soil water usage in the Loess Plateau,China

Sowing date and seeding rate are critical for productivity of winter wheat(Triticum aestivum L.).A three-year field experiment was conducted with three sowing dates(20 September(SD1),1 October(SD2),and 10 October(SD3)) and three seeding rates(SR67.5,SR90,and SR112.5) to determine suitable sowing date and seeding rate for high wheat yield.A large seasonal variation in accumulated temperature from sowing to winter dormancy was observed among three growing seasons.Suitable sowing dates for strong seedlings before winter varied with the seasons,that was SD2 in 2012–2013,SD3 in 2013–2014,and SD2 as well as SD1 in 2014–2015.Seasonal variation in precipitation during summer fallow also had substantial effects on soil water storage,and consequently influenced grain yield through soil water consumption from winter dormancy to maturity stages.Lower consumption of soil water from winter dormancy to booting stages could make more water available for productive growth from anthesis to maturity stages,leading to higher grain yield.SD2 combined with SR90 had the lowest soil water consumption from winter dormancy to booting stages in 2012–2013 and 2014–2015; while in 2013–2014,it was close to that with SR67.5 or SR112.5.For productive growth from anthesis to maturity stages,SD2 with SR90 had the highest soil water consumption in all three seasons.The highest water consumption in the productive growth period resulted in the best grain yield in both low and high rainfall years.Ear number largely contributed to the seasonal variation in grain yield,while grain number per ear and 1 000-grain weight also contributed to grain yield,especially when soil water storage was high.Our results indicate that sowing date and seeding rate affect grain yield through seedling development before winter and also affect soil water consumption in different growth periods.By selecting the suitable sowing date(1 October) in combination with the proper seeding rate of 90 kg ha–1,the best yield was achieved.Based on these results,we recommend that the current sowing date be delayed from 22 or 23 September to 1 October.

Cooling Water Flow Rate Calculation for Hearth of Large Blast Furnaces

The cooling water flow rate for hearth of large blast furnaces was calculated by simulation. The results show that the cooling water flow rate shall be above 4 200m3/ h for hearth of large blast furnaces; to meet requirements of the increasing smelting intensity and to ensure the safety at the end of the first campaign,the designed maximum cooling water flow rate should be 5 900m3/ h; according to the flow distribution stability and the calculated resistance loss,hearth cooling stave pipes with the specification of 76 mm × 6 mm shall be adopted to assure the flow velocity in pipes of hearth cooling stave in the range of 1. 9- 2. 3 m / s.

Reuse rate of treated wastewater in water reuse system

A water quality model for water reuse was made by mathematics induction. The relationship among the reuse rate of treated wastewater（R）, pollutant concentration of reused water（ Cs ）, pollutant concentration of influent（ C0）, removal efficiency of pollutant in wastewater（ E）, and the standard of reuse water were discussed in this study. According to the experiment result of a toilet wastewater treatment and reuse with membrane bioreactors, R would be set at less than 40%, on which all the concerned parameters could meet with the reuse water standards. To raise R of reuse water in the toilet, an important way was to improve color removal of the wastewater.

A study of Indian Ocean Subtropical Mode Water: subduction rate and water characteristics

The annual subduction rate in the South Indian Ocean was calculated by analyzing Simple Ocean Data Assimilation （SODA） outputs in the period of 1950-2008. The subduction rate census for potential density classes showed a peak corresponding to Indian Ocean subtropical mode water （IOSTMW） in the southwestern part of the South Indian Ocean subtropical gyre. The deeper mixed layer depth, the sharper mixed-layer fronts and the associated relatively faster circulation in the present climatology resulted in a larger lateral induction, which primarily dominants the IOSTMW subduction rate, while with only minor contribution from vertical pumping. Without loss of generality, through careful analysis of the water characteristics in the layer of minimum vertical temperature gradient （LMVTG）, the authors suggest that the IOSTMW was identified as a thermostad, with a lateral minimum of low potential vorticity （PV, less than 200× 10^-12 m^-1·s^-1） and a low dT/dz （less than 1.5℃/（100 m））. The IOSTMW within the South Indian Ocean subtropical gyre distributed in the region approximately from 25° to 50° E and from 30° to 39°S. Additionally, the average characteristics （temperature, salinity, potential density） of the mode water were estimated about （16.38 ± 0.29）℃, （35.46 ±0.04）, （26.02 ±0.04） ae over the past 60 years.

Leakage Rate Model of Urban Water Supply Networks Using Principal Component Regression Analysis

To analyze the factors affecting the leakage rate of water distribution system, we built a macroscopic "leakage rate–leakage factors"(LRLF) model. In this model, we consider the pipe attributes(quality, diameter,age), maintenance cost, valve replacement cost, and annual average pressure. Based on variable selection and principal component analysis results, we extracted three main principle components—the pipe attribute principal component(PAPC), operation management principal component, and water pressure principal component. Of these, we found PAPC to have the most influence. Using principal component regression, we established an LRLF model with no detectable serial correlations. The adjusted R2 and RMSE values of the model were 0.717 and 2.067, respectively.This model represents a potentially useful tool for controlling leakage rate from the macroscopic viewpoint.

A QUANTITATIVE STUDY ON ENHANCEMENT OF TYPE Ⅱ PHOTOSENSITIZED OXIDATION REACTION RATE BY HEAVY WATER

A method for quantitative evaluating the enhancement of the rate of Type Ⅱ photosensitized oxidation by D_2O was suggested. The effect of substrate concentration on this process was also discussed.

EFFECTS OF TEMPERATURE AND DISSOLVED OXYGEN CONTENT ONOXYGEN CONSUMPTION RATE OF CHINESE PRAWN, GIANT TIGER PRAWN AND GIANT FRESHWATER PRAWN

temperature and the diasolved oxygen content affect the oxygen consumption of juveniles of Chinese prawn (Penaeus chinensis), giant tiger prawn (P. monodon) and giant freshwater prawn(Macrobrachium rosenbergii). There is good correlation between the oxygen consumption rate (V, mg/g·h) of the above three prawn species and the water temperature, and dissolved oxygen. In the range of test temperature, V increased with water temperature and diassolved oxygen content. The V of the above three prawn species increased 0.085 mg/g·h, 0. 093 mg/g·h and 0. 08 mg/g·h respectively with each ℃ of rising temperature. The comatose point and stifling point of the juveniles rose obviously at unsuitable temperature.

Surface warming patterns dominate the uncertainty in global water vapor plus lapse rate feedback

Climate feedbacks have been usually estimated using changes in radiative effects associated with increased global-mean surface temperature. Feedback uncertainties, however, are not only functions of global-mean surface temperature increase. In projections by global climate models, it has been demonstrated that the geographical variation of sea surface temperature change brings significant uncertainties into atmospheric circulation and precipitation responses at regional scales. Here we show that the spatial pattern of surface warming is a major contributor to uncertainty in the combined water vapour-lapse rate feedback. This is demonstrated by computing the global-mean radiative effects of changes in air temperature and relative humidity simulated by 31 climate models using a methodology based on radiative kernels. Our results highlight the important contribution of regional climate change to the uncertainty in climate feedbacks, and identify the regions of the world where constraining surface warming patterns would be most effective for higher skill of climate projections.

Prediction of Trend between Water Environment Pollution of D Lake and Death Rate of Malignancy in Population

Grey system analysis method was used to study the correlation between water pollution in D Lake area and death rate of malignancy with death rate of malignancy as effect sequence and a variety of water pollution index as factor sequence. On the basis of grey correlation analysis, grey system predication model was established for death rate of malignancy in population in D Lake area including GM (1, N) model for death rate of malignancy [ MR (t+1) =(9.9987E 1+5.0001E 2 +10.8994E 3+1.1114E 4+165.1029) ·e -0.0070t -9.9987E 1-5.0001E 2-10.8994E 3-1.1114E 4 ] and GM (1, 1) model for related factors [ E 1(t+1) =52.1214-46.9468e -0.0058t , E 2(t+1) =4.6114-4.5664e 0.0015t, E 3(t+1) =1.1389-1.1212e 0.0065t , E 4(t+1) = 554.5867-549.8006e 0.0016t ], and the trend of death rate of malignancy from 2000 to 2010 was predicted.

Effects of Seeding Rate, Water and Fertilizer Coupling on Grass Yield of Forage Millet ( Setaria itlica) in Hebei

The paper was to study the effects of seeding rate, water and fertilizer （ N, P, K） coupling on grass yield of forage millet Jigu No. 18 （Setaria itlica）. A quadratic regression otthogonal rotation combination with five factors was designed in pot experiment. The mathematical model between hay yield of forage millet （Y） and soil moisture content （ x1 ）, N fertilizer （x2 ）, P fertilizer （x3 ）, K fertilizer （x4） and seeding rate （x5 ） was established to simulate optimization. The results showed that moisture content, seeding rate, P fertilizer and K fertilizer had important effects on hay yield. Soil moisture content had the biggest impact on yield, followed by seeding rate, P and K fertilizer. The coupling effects of various factors successively were moisture content / seeding rate 〉 K fertil- izer/seeding rate 〉 N / P fertilizer 〉 soil moisture/N fertilizer 〉 soil moisture/ P fertilizer. Moreover, the mathematical model, Y = 20 543. 756 - 565. 570xI -39. 942x2 -23. 102x3 -38. 470x4 - 151. 877x5 ＋ 1. 052x^x2 ＋ 1. 604xIx3 ＋ 12. 953xt x5 - 0. 173x2x3 ＋ 0. 737x4x5 - 2. 292x5^2, was established. The optimum soil moisture and seeding rate were determined as 10% andl5 kg/hm2, respectively. In this scheme, the hay yield was 14 037. 151 0 kg/hm^2 and the economic benefit was 13 887.15 yuan/hm^2 ; the income was increased by 23.68% （ 3 288.98 yuan/hm^2 ） compared to the optimal combination in the test. The results provided a theoretical basis and technical support for forage millet production in Hebei Province.

Effect of Digested Sewage Sludge on the Ventilation and Coughing Rates of Two Fresh Water Fish

Addition of digested sewage sludge at concentrations of 2% and 10% (v/v) to the water increased coughing rate in big head and tilapia (P<0.05). Ventilation rate was significantly decreased (P<0.05) in big head and tilapia at sludge concentrations of 6% and 2% (v/v)respectively. Copper (Cu), cadmium (Cd) and zinc (Zn) are trace metals which are commonly found in sludge. Cu caused a significant increase (P<0.05) in coughing rate in both tilapia and big head at concentrations of 0.3 and 0.2 μg/ml respectively. Zn caused significant increase (P<0.05) in coughing rate only in big head at 2 μg/ml. Neither fish responded to Cd of up to 2μg/ml in the water. However, when the levels of these trace metals in the digested sludge were measured, they were below that which can cause significant changes in the respiratory movements. Therefore, the changes in ventilation and coughing rates after addition of sludge may be due to the presence of substances other than these metals. The results of this experiment provides a guideline to control the level of sludge that can be used in rearing these fresh water fish in ponds

Molecular Orbital Nature of Solubility of Shot Chain n-Alkanes in Water and Their Reaction Rate Constants with Nitronium Cations: A DFT Study

The new theoretical models describe both the solubility S of the shot chain n-alkanes in water at 298.15 K, and their reaction rate constants k with nitronium cation NO2+ at 293.15 K on the basis of their molecular orbital characteristics. It is shown that both the quantities S and k are determined by the energies Eorb of the specific virtual (for S) and occupied (for k) molecular orbitals of these n-alkanes. The obtained regression equations confirm the theoretically found dependences of S and k on the absolute value of Eorb. This fact demonstrates that the electronic structure particularities of the studied n-alkanes play a crucial role in both their above-mentioned physicochemical properties.

Synthesis and Characterization of Alumina-Zirconia Powders Obtained by Sol-Gel Method: Effect of Solvent and Water Addition Rate

The influence of solvent and the rate of addition of water on the characteristics of alumina-zirconia powders obtained by sol-gel method were investigated. The Al2O3-ZrO2 powders (1:1 molar ratio) were prepared using aluminum tri-sec-butoxide and zirconium n-propoxide as precursors. Ethanol (EtOH), isopropanol (iPrOH) and isobutanol (iBuOH) were used as solvents. The Al2O3-ZrO2 powders were characterized by nitrogen physisorption (SBET), Fourier transformed infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscopy (SEM). Prepared oxides calcined at 700℃ showed high specific surface area (200 - 240 m2/g). Obtained results suggest that the homogeneity of the mixed oxides is favored by using a water addition rate of 0.06 and 0.10 mL/min with ethanol as solvent.

Variable Chlorine Decay Rate Modeling of the Matsapha Town Water Network Using EPANET Program

A variable chlorine decay rate modeling of the Matsapha town water network was developed based on initial chlorine dosages. The model was adequately described by a second order rate function of the chlorine decay rate with respect to the initial chlorine dose applied. Simulations of chlorine residuals within the Matsapha water distribution network were run using the EPANET 2.0 program at different initial chlorine dosages and using the variable decay rate as described by the second order model. The measurement results indicated that the use of constant decay rate tended to underestimate chlorine residuals leading to potentially excess dosages with the associated chemical cost and side effects. The error between the two rate models varied between 0% and 15%. It is suggested that the use of water quality simulation programs such as EPANET be enhanced through the extension programs that accommodate variable rate modeling of chlorine residuals within distribution systems.

Study on the Influence of Sowing Rate,Water and Fertilizer Coupling on Water Use Efficiency of Fodder Millet

To study the influence of sowing rate,water and fertilizer( N,P and K) coupling on water use efficiency of fodder millet grown in autumn fallow field,taking " Jigu 18" as the tested material,a orthogonal rotation combination with five factors was designed in pot experiment. Results showed that both water and phosphate fertilizer had important impacts on water use efficiency,in which water had the maximum impact,followed by phosphate fertilizer,and nitrogen fertilizer,potassium fertilizer and sowing rate all had no obvious impact. Significant item of sowing rate,water and fertilizer coupling had the below sequence: potassium fertilizer + sowing rate > nitrogen fertilizer + phosphate fertilizer > water + phosphate fertilizer > water + sowing rate > water + potassium fertilizer,and other items had no obvious impact. Mathematical model was established: y = 44. 26- 1. 311x1- 2. 298x2- 3. 682x3- 6. 401x4- 34. 540x5+ 0. 273x1x3+ 0. 118x1x4+ 0. 843x1x5- 1. 948x2x3+ 6. 631x4x5. The optimal scheme taking economic benefit as the examining index was cleared,that is,soil water content maintained 10%,and sowing rate of fodder millet was 15 kg / hm2. By the scheme,water use efficiency was 26. 24 g / kg,and hay yield was13980. 90 kg / hm2,with economic benefit of 13830. 90 yuan/hm2,which was 3063. 73 yuan/hm2 more than the optimized combination with the highest hay yield,with increase magnitude of 22. 15%,and was 6215. 15 yuan / hm2 more than the optimized combination with the highest water use efficiency,with increase magnitude of 44. 94%. The research could provide theoretic basis and technical support for production practice of fodder millet grown in autumn fallow field.

Vibration pore water pressure characteristics of saturated fine sand under partially drained condition

Vibration pore water pressure characteristics of saturated fine sand under partially drained condition were investigated through stress-controlled cyclic triaxial tests employed varied fine content of samples and loading frequency. In order to simulate the partially drained condition, one-way drainage for sample was implemented when cyclic loading was applied. The results show that the vibration pore water pressure's response leads the axial stress and axial strain responses, and is lagged behind or simultaneous with axial strain-rate's response for all samples in this research. In addition, the satisfactory linear relationship between vibration pore water pressure amplitude and axial strain-rate amplitude is also obtained. It means that the direct cause of vibration pore water pressure generation under partially drained conditions is not the axial stress or axial strain but the axial strain-rate. The lag-phase between pore water pressure and axial strain-rate increases with the increase of the fine content or the loading frequency.