Long term effects of inorganic fertilizer inputs on crop productivity in a rice-wheat cropping system

Three levels of N (40,80,120 kg N ha^-1) and P (0,17.5,35 kg P ha^-1), and 2 levels of K (0,33 kg K ha^-1) were tested for 19 years in rice and wheat crops of a rice-wheat cropping system in a fixed layout of 3×2×2 factorial partially confounded design along with one control and 3 replications. From this trial, data of 7 treatments, i.e. 0-0-0, 40-35-33, 80-35-33, 120-35-33, 120-0-0, 120-35-0 and 120-0-33 kg ha^-1 N-P-K respectively were compared for yield trends, changes in response functions, soil organic -C and available N,P,K status. Soil organic - C decreased in unfertilized plots by 62% (over initial value of 0.45%) but increased by 44, 40 and 36% in plots receiving 120-35-33, 120-35-0 and 80-35-33 kg ha^-1 N-P-K respectively. Available N was also greatest in these same three treatments. Available soil P increased by about 5 fold in 15 years in treatments supplied with fertilizer P, but no significant change was detected in treatments without P addition. Yields of rice and wheat exhibited linear declining trend in all treatments. The highest rate of decline (89 kg ha^-1 year^-1 in rice and 175 kg ha^-1 year^-1 in wheat), however, was found when 120 kg ha^-1 N was applied alone. The least rate of decline of 20 kg ha^-1 year^-1 in rice and 58 kg ha^-1 year^-1 in wheat was observed when 40-35-33 kg ha^-1 N-P-K respectively was applied to both the crops. At currently recommended levels of NPK (120-35-33 kg ha^-1), the rate of decline in yields was 25 kg ha^-1 year^-1 for rice and 62 kg ha^-1 year^-1 for wheat. Possible causes of these yield declines are discussed.     

Long term thromboresistance of heparinized surfaces

It has long been known that interaction of blood with artificial surfaces results in thrombogenic effects. With the increased use of prosthetic cardiovascular appliances, it is becoming more evident that surfaces which are thromboresistant are of utmost importance. A review is presented of the recent research on binding of heparin by ionic, covalent and thermal means, to different polymer surfaces, with the results of in vitro and in vivo tests. Additionally, a survey of theories on the role of heparin surfaces in thromboresistance is given.     

Long term experiments on sea water desalination at the Chigasaki Laboratory

The technology of producing fresh water from sea water by the reverse osmosis (RO) process has been developed since 1974 under the supervision of the Ministry of International Trade and Industry. Highly satisfactory and stable performances have been recorded for the two-stage desalination process using RO modules developed in Japan. Durability of the membranes under testing is expected to last more than three years. The quality of the product water can be kept below TDS 200 ppm that is suitable for potable consumption. Construction of a demonstration plant of 500 m³ /day using domestic modules is now being planned.     

Long term effects of fertilization on carbon and nitrogen sequestration and aggregate associated carbon and nitrogen in the Indian sub-Himalayas

An understanding of the dynamics of soil organic carbon (SOC) as affected by farming practices is imperative for maintaining soil productivity and also for restraining global warming by CO₂ evolution. Results of a long-term (30 year) experiment in the Indian Himalayas under rainfed soybean (Glycine max L.)—wheat (Triticum aestivum L.) rotation was analyzed to determine the influence of mineral fertilizer and farmyard manure (FYM) application at 10 Mg ha⁻¹ on SOC and total soil nitrogen (TSN) stocks and distribution within different aggregate size fractions. Fertilizers (NP, NK and NPK) and FYM in combination with N or NPK were applied before the soybean crop every year and no nutrient was applied before the wheat crop. Results showed that addition of FYM with N or NPK fertilizers increased SOC and TSN contents. The overall gain in SOC in the 0- to 45-cm soil depth interval in the plots under NPK + FYM treatment over NPK was 17.18 Mg C ha⁻¹ in 30 year. The rate of conversion of input C to SOC was about 19% of each additional Mg C input per hectare. SOC content in large size aggregates was greater than in smaller size aggregates, and declined with decreased aggregate size. Thus, long-term soybean–wheat rotation in a sandy loam soil of the Indian Himalayas sequestered carbon and nitrogen. Soil organic C and TSN sequestration in the 0.25- to 0.1-mm size fraction is an ideal indicator of long-term C and N sequestration, since this fraction retained maximum SOC/TSN stock.     

Long term investment considerations of conjunctive desalting systems

Previous research which dealt with the desirability of considering water projects in a long range context, the measurement and costs of technological progress, and the value of preserving flexibility in future decision making has been combined and applied to the evaluation of the proposed prototype 40-mgd Diablo Canyon desalination plant. An alternative to the desalination plant is a very large scale aqueduct. In this paper the two projects are evaluated together as complementary components of a long range project against the alternative of earlier construction of the aqueduct. The analysis concerns the interest rate, growth rate, demand elasticity, planning horizon, number of planning periods, and area growth rate in parametric form. A simplified numerical example is given.     

中低低CO变换工艺长周期运行的技术措施

中低低CO变换工艺比中串低工艺具有更好的节能效果,且能适当提高原有装置的生产能力,而又不似全低变那样对原料气净化有着过高的要求,因此倍受青睐。目前,中低低工艺已成为大多数厂家变换技术改造的首选方案。近年来我们针对中低低工艺存在的问题进行了研究,找出了问题的关键,从设计与运行两个方面提出了改进方案,并在河北省石家庄滹沱河化肥厂、正定化肥厂、安徽省涡阳化肥厂等厂实施,完全达到了预期的效果。1　中低低工艺运行初期的能耗指标可与全低变媲美中低低工艺较中变串低变的吨氨汽耗低,一般可从中串低的500～600kg下降到200～300k…     

Fluidization studies in large gas—solid systems Part V. Long and short term pressure instabilities

Long and short term variations in overall bed pressure drop and also pressure non-uniformities at the base of a 1.2 × 1.2 m square cross-section fluidized bed have been investigated for a range of fluidizing conditions. The results obtained are explained in terms of the probable solid flow patterns within the bed.The marked effect of a vertical tube bundle on long term pressure non-uniformity was observed; in contrast, no effect was noted when distributor pressure drop was increased approximately fivefold.     

High-pressure effects on lipid oxidation

Rendered pork fat (0.44 water activity, A_w) was subjected to high-pressure treatment of 800 MPa for 20 min at 19°C prior to storage at 4, 25, and 50°C. In all cases, high pressure-treated samples oxidized more rapidly (had a shorter induction period) as shown by the peroxide value (PV), 2-thiobarbituric acid value, and ultraviolet absorbance. The effect was less marked at lower pressures. In contrast, at all water activities outside the range of 0.40–0.55, the PV of the high pressure-treated pork fat was lower than control samples stored similarly, and the PV of rancid fat decreased slightly on pressure treatment at 19°C, but not at higher temperatures. This effect may explain the observed inhibition of oxidation at most water activities. At 0.40–0.55 A_w, other factors, such as the liberation of transition metals, may override the destruction of peroxides.     

Long term activity of modified ZnO nanoparticles for transesterification

Biodiesel can be produced by the transesterification of natural oils with methanol using modified ZnO nanoparticles as catalyst. Crude algae oil, corn oil from DDGs, crude palm oil, crude soybean oil, crude coconut oil, waste cooking oil, food-grade soybean oil and food-grade soybean oil with 3% water and 5% FFA addition were converted into FAME within 3 h using this new catalyst. The ZnO nanoparticles were reused 17 times without any activity loss in a batch stirred reactor and the average yield of FAME was around 93.7%. ZnO nanoparticles were used continuously for 70 days in a fix bed continuous reactor and the average yield of FAME was around 92.3%. XRD, ICP, TEM and HRTEM were used to characterize the long term used catalyst structure. Results show that this catalyst is a mixture of wurtzite ZnO nanoparticles and some amorphous materials and that the used catalysts have similar crystal structure to fresh catalyst. ICP results show that this catalyst does not dissolve in biodiesel, methanol, oil and glycerine-methanol solutions. It has a stable crystal structure under the reaction conditions. The high catalytic activity, long catalyst life and low leaching properties demonstrate these modified ZnO nanoparticles have potential in a commercial biodiesel production process.     

Long term storage of soybean and cottonseed salad oils

Commercially prepared and packaged soybean and cottonseed salad oils from several different processors were evaluated periodically during storage for 12 months. Partially hydrogenated and winterized soybean oils, as well as unhydrogenated soybean salad oils, were stored in bottles and cans at 78 and 100 F. Control samples of all oils were held at 0 F during the entire test. Some lots in bottles and cans were packaged under nitrogen to improve storage stability. Agreement was good between organoleptic and oxidative evaluation of aged oils. After 26 weeks of storage at 100 F, the flavor of partially hydrogenated-winterized oils packaged under nitrogen showed a minimum loss. These same oils did not exhibit much, if any, reduction in their oxidative stability as indicated by storage peroxide values (active oxygen method). Soybean oil not protected with nitrogen demonstrated progressive flavor deterioration at 100 F. After 10 weeks of storage, the deterioration became marked and the flavor score was below 5. From limited observations, bottled oils appear to have a better stability than oils packaged in screw-cap tin cans. Hydrogenated oils packaged under nitrogen in cans had good oxidative stability, but some lowering of the flavor score was observed. Nonhydrogenated soybean oils packaged in tin cans not under nitrogen exhibited the most rapid flavor deterioration of all lots of oil investigated. Presented in part at the AOCS meeting, New York, October 1968 ARS, USDA     

Dual-labeled technique for human lipid metabolism studies using deuterated fatty acid isomers

Two deuterated fatty acids, elaidate-d ₂ and oleate-d ₄, were fed simultaneously to a human subject as a mixture of trielaidin-d ₆ and triolein-d ₁₂. Periodically, blood samples were drawn, and red blood cells were separated from the plasma. Red blood cells and plasma lipids were fractionated and analyzed by combined gas chromatography—multiple ion mass spectroscopy. Dual deuterium-labeling allows rate and extent of fatty acid incorporation to be followed in various plasma and red cell neutral and phospholipid fractions. Maximum amount of deuterated fat varied from 4% in cholesterol ester to 64% in phosphatidyl ethanolamine. The highest levels of deuterated fat occurred in either 6-, 8-, or 12-hr samples; generally, <1% labeled fatty acids could be detected in 72-hr samples. Because the method is based on dual-labeling, differences in the relative incorporation of both fatty acid isomers can be compared directly. Differences in rates of incorporation, rates of removal, and extent of incorporation of labeled fatty acids into blood plasma can also be determined reliably. Our experimental labeling of fats with deuterium permits for the first time the metabolism of two fatty acid isomers to be compared simultaneously in human subjects. This new method should be applicable to a variety of other lipid metabolic studies. Presented at the AOCS meeting Dallas, Texas, April 27–30, 1975.     

不同气氛对硫化钙和磷石膏反应的影响研究*

硫化钙与磷石膏之间的固-固反应,以生成氧化钙和二氧化硫的反应为优势反应,同时反应中存在许多副反应。考虑到实际工业生产情况,在高温管式炉中,控制硫化钙与硫酸钙物质的量比为1.2∶3,在氮气、二氧化硫混合气氛基础上,逐步引入二氧化碳、一氧化碳、氧气等气氛,研究外加气氛对磷石膏分解率的影响。结果表明,不同的气氛对固-固反应有不同的影响。高物质的量分数的二氧化硫和氧气会抑制反应,使得磷石膏分解率大幅度降低;一氧化碳可以促进磷石膏的分解;二氧化碳的存在对反应几乎没有影响。     

Long term stability of electrocaloric response in barium zirconate titanate

The stability of the electrocaloric effect under electric field cycling is an important consideration in the development of solid-state cooling devices. Here we report measurements carried out on Ba(Zr_0.2Ti_0.8)O₃ ceramics which reveal that the adiabatic temperature change, polarization-electric field hysteresis loops and dielectric permittivity/loss show stable behavior up to 10⁵ cycles. We further demonstrate that the loss in electrocaloric response observed after 10⁵ cycles is associated with the migration of oxygen vacancies. As a result, the electrical properties of the material are changed leading to an increase in leakage current and Joule heating. Reversing the polarity of the electric field after every 10⁵ cycles changes the migration direction of oxygen vacancies, thereby preventing charge accumulation at grain boundaries and electrodes. By doing so, the electrocaloric stability is improved and the adiabatic temperature remains constant even after 10⁶ cycles, much higher than achieved in commercially available barium titanate ceramics.     

Non-soluble dietary fiber effects on lipid absorption and blood serum lipid patterns

Generalized effects of dietary fiber on lipid absorption and blood serum lipid patterns of humans have not been defined and may not even exist. The term dietary fiber covers a wide variety of materials with different chemical and physical characteristics. The ability of pectins and mucilages, often classed as soluble fibers, to lower blood and liver lipids has been demonstrated repeatedly and consistently. However, demonstrated hypolipidemic effects of feeding such non-soluble fibers as cellulose, hemicellulose and bran are by no means consistent. On the basis of pooled data, it appears that hypolipidemic response or non-response of humans to inclusion of non-soluble fibers in diets is in part related to the degree of fecal bulking as a result of in vitro water holding capacity and in part related to pre-study blood serum lipid levels of the individual subjects.     

Long term chemical stability of epichlorohydrin/bisphenol resin polymer concrete

The chemical stability of an epichlorohydrin/bisphenol resin polymer concrete under corrosive environment is investigated over a long period extending to 625 days. The results indicate a levelling off at a loss of approximately 50 per cent of the compressive strength at room temperature under the action of the most critical corrosive environment. The combined characteristics of high strength and resistance to corrosive environment render the developed polymer concrete an attractive alternative construction material for bridge decks, pavements, tunnels, underwater structures and long-term storage of radioactive nuclear waste material, contingent on a carefully designed cost effective analysis.     

Long chain branching and polydispersity effects on the rheological properties of polyethylenes

The rheological behavior of linear, and branched polyethylenes is studied as a function of the weight average molecular weight (M_w) and its distribution (MWD) as well as the level of long chain branching in an attempt to identify correlations between long chain branching, polydispersity and rheological properties. It is found that a need for vertical shift of the viscoelastic moduli data to obtain the master curves using the time‐temperature superposition principle is associated with the existence of long chain branching in the structure of the polymer. The degree of vertical shift is found to correlate with the level of long chain branching. This correlation corroborates with the observation that long chain branching correlates with the horizontal flow energy of activation. Plots of atan(G″/G′) vs. G* (known as Van Gurp plots) also reveal some important features that can be used as signs of specific features in the structure of polymers. More specifically, the area included below the Van Gurp curves correlates with the level of long chain branching and polydispersity index. The correlations are presented in graphical form and they can be used to associate rheological properties with the presence of long chain branching and/or polydispersity.     

The effects of sterilisation on the properties of calcium sulphate hemihydrate

Plaster of Paris has been recommended as a suitable bone substitute material. In this project both calcined and autoclaved plasters have been prepared and the effects of sterilisation on their properties determined. Samples of plaster suitable for use in animal experimentation have been prepared.     

Numerical studies of the effects of fines on fluidization

Euler‐Lagrange simulations of fluidized beds of Geldart Group A particles containing different levels of fines are performed in periodic domains with various domain‐averaged solid volume fractions. Bubble‐like voids readily form when no fines are added. Introducing fines does not reduce bubble sizes if van der Waals force between particles is not accounted for. In contrast, the addition of van der Waals force produces significant changes. With no fines, bubbles are found to be suppressed at sufficiently high solid volume fractions, corresponding to the expanded bed regime for Group A particles. With the addition of fines, bubbles can be suppressed at lower solid volume fractions. With more fines added, bubbles can be suppressed at even lower solid volume fractions. When bubbles are suppressed, the system is found to be in a stable solid‐like regime. In this regime, forces on each particle are balanced, and the particle velocity fluctuations are dampened. © 2016 American Institute of Chemical Engineers AIChE J, 62: 2271–2281, 2016