methods of studying root systems in the laboratory

... located within a chamber enclosing the soil surface, and the system measures the rate of diffusion into the surface In both modes the gas cell containing the detector is isolated from the probe ... measurement of diffusion The same techniques are generally applicable in the field and in the laboratory Steady-state laboratory techniques offer the advantage of preserving laminar flow of gases ... origins of their soils Copyright © 2000 Marcel Dekker, Inc 518 Ball and Smith Due to the increasing interest in soil structure, steady state methods involving soil cores have developed further The...

Ngày tải lên: 11/08/2014, 15:20

... a molecule of X remains in the box Mathematically τ can be defined as the ratio of the mass m (in kg) of X in the box to its removal rate, which is the sum of the flow of X out of the box (Fout), ... between the atmosphere and the other compartments of the planet An example is the mixing of atmospheric gases into the oceans  a chemical change at the interface between the atmosphere and the other ... decadal levels Since the beginning of the Industrial Revolution, the concentrations of most of the greenhouse gases have increased For example, the mole fraction of carbon dioxide has increased by...

Ngày tải lên: 09/06/2016, 14:47

... paper involves only cutting and packaging, with a small amount of printing required on the packaging Tissue and paper towel converting operations consist mainly of cutting, folding and placing in ... cutting, folding, corrugating, gluing and printing The production of magazines containing a large number of high-quality images can result in significant emissions of greenhouse gases, owing ... gases in other ways These impacts often occur outside the industry’s value chain, and measuring them usually requires assumptions about the emissions that would occur in the absence of the industry’s...

Ngày tải lên: 24/03/2014, 05:20

... Global Warming Initiative was started by the Governors of California, Oregon, and Washington in 2003 The goals of the initiative include combining purchasing power to improve the efficiency of vehicle ... production using virgin inputs; in other cases, these emissions result when either virgin or recycled inputs are used These emissions are described in Chapter Carbon Sinks: The only carbon sink associated ... reductions in GHG emissions EPA encourages Partners to continue efforts in promoting these programs and measuring their impact The international community has shown considerable interest in using the...

Ngày tải lên: 31/03/2014, 13:20

... deal of the associated additional heat flux and hence will delay warming of the atmosphere During the 1980s the UK Meterological Office (UKMO) developed one of the most advanced models of the ... response of the climate system to external forcing The circulation and thermal structure of the upper ocean control the penetration of heat into the deeper ocean and hence the time delay which the ... and their seasonal variability Ocean modelling and validation are less advanced than atmospheric modelling, reflecting the greater difficulty of observing the interior of the ocean and of inadequate...

Ngày tải lên: 10/08/2014, 20:20

... aerobic tank of the former basin continues to enter the anoxic tanks of the following basin and go through further treatment The final secondary effluent exit from basin and heads to the sedimentation ... sedimentation tanks Empty basin P1 P3 P4 P5 P6 P2 Basin Basin Basin Basin Basin Figure 3.2 Sketch of BNR bioreactor (Train 2) in CWRP 27 Basin The designed length and width of the train is around 117 by ... locate at the inlets of the five functioning aerobic tanks One more point was selected to be at the center of the aerobic tank of basin for the comparison within one plug-flow tank as shown in Figure...

Ngày tải lên: 27/11/2015, 12:12

... colonisation is rather the rule than the exception after prolonged persistence of infection10 All these findings indicate that the incidence and dimension of prosthetic joint infection is grossly underestimated ... Khardori N In vitro activity of vancomycin, quinupristin/dalfopristin, and linezolid against intact and disrupted biofilms of staphylococci Ann Clin Microbiol Antimicrob 2005;4:2 The authors ... eradication of planktonic residues but are not effective in eliminating micro-clusters disrupted from biofilms that may be the cause of recurrence after an indefinite period of time Fragments of biofilms...

Ngày tải lên: 26/10/2012, 09:53

... (2000) Effect of feeding characteristics on methane production • Digestible organic matter or energy • Residence time in the rumen and level of intake • Source of C and pattern of fermentation ... Not considering respiration Livestock’s share in methane emissions 37 percent Livestock’s share in nitrous oxide emission 65 percent Source: Steinfeld et al (2006) Including production of feed crops ... contribution climate change in CO2 equivalent 18percent Includingpasture degradation and assuming that two-thirds of land use change is livestock related Livestock’s share in carbon dioxide emissions...

Ngày tải lên: 14/04/2013, 16:04

... extracted and the amount of labelled PtdIns was determined (Table 1) In the absence of CMP, the presence of AtPIS1 allows the incorporation of labelled inositol into PtdIns, according to the enzymatic ... disappearance of PtdIns in the lower phase ()108 pmolÆmin)1Æmg)1) On the other hand, membranes lacking AtPIS1 not induce any variation in the radioactivity partitioned between each phase during the incubation ... with different substrates The values indicated and in pmol PtdInsÆmin)1Æmg)1 protein In the upper phase they are given as pmol inositolÆmin)1Æmg)1 Each value is the mean ± SD of four (+PIS) or three...

Ngày tải lên: 22/02/2014, 04:20

... probably because of the improved particle packing density in the sensing film Thus, the results obtained indicate the importance of the microstructure control of sensing layers in terms of tube length, ... on the promotion of the gas sensitivity through the porosity control of gas sensing films The porosity was controlled by changing the calcination temperature and the condition of ball-milling ... the films composed of commercial TiO2 particles and TiO2 nanotubes obtained at 230oC, respectively, indicating that the porosity of the film was increased by using the nanotubular particles The...

Ngày tải lên: 19/03/2014, 16:47

... born in 1958 in Minsk, Belarus He received the MSc degree in electronic engineering in 1984 from Minsk Radio Engineering Institute and the PhD degree in electronic engineering in 1999 from the Institute ... too many neurons in the hidden layer This eliminates much of the trial and error in finding the optimal number of neurons to include in the hidden layer When using the classifiers, the hold-out method ... gradients) during the hit, and another N points for the first 7.2 (60% of the recovery period) after the hit The characteristics of the response are mainly determined by the type of gas and its...

Ngày tải lên: 20/03/2014, 13:07

... Cavendish in 1785 Cavendish also showed t h a t the combustion of hydrogen in excess of air gave water containing nitric acid The combination of nitrogen and oxygen in the electric arc was further ... to increase the yield of nitric o x i d e , but the effect of further increase of pressure up to 45 a t m o s offers no advantages The use of temperatures attained b y surface combustion for the ... solution of nitric acid may be obtained by burning hydrogen in an equimolecular mixture of oxygen and nitrogen The question of the production of oxides of nitrogen in explosions in which excess of...

Ngày tải lên: 09/05/2014, 17:03

... establish kinetic laws for hydrocarbon oxidation first of all due to the high endothermicity of this reaction resulting in sinstering of the catalyst, in surface changes, and in the intensification of ... a function of the partial pressure The linear relationship of this equation is maintained in the range of 0.05 < P/P0 < 0.30 [102] The specific surface area of the samples in this thesis were ... the simultaneous treatments of these pollutants (CO, HC, NOx, soot) Furthermore, the influence of aging and activation processes to the activity of the catalysts was investigated in details in...

Ngày tải lên: 12/05/2014, 17:14

... model of mapping creating and use, where the success of mapping creation is discovered by the use of mappings in a self-organizing manner 3.4 Building and Maintaining Semantic P2P Applications Intelligent ... arise in pure P2P systems in the querying of distributed information and knowledge 2.2 Motivation On the one end of the architectural spectrum there is the integration of the standalone systems ... for the method that is used in following iterations Automatic methods that try to find mappings without the intervention of the user at the price of possibly incorrect and incomplete mappings The...

Ngày tải lên: 03/06/2014, 02:00

... natural and synthetic) that delay bacterial oxidation of NH4+ either by temporarily suppressing the activities of nitrifiers or killing them in the soil, thus maintaining the applied N in more stable ... radiation within the thermal infrared range from the source However, with the enormous burning of fossil fuels from the industrial revolution, the concentration of greenhouse gases in the atmosphere ... composition of the fuel, engine design, conditions of operation, the intermediate species that are formed during the process and the presence of a catalyst in the exhaust The blended ethanol gasoline...

Ngày tải lên: 28/06/2014, 17:20

... important role in balancing the temperature of the Earth’s surface by absorbing and emitting radiation within the thermal infrared range from the source However, with the enormous burning of fossil ... important for increase the heating value of the natural gas and limiting the CO2 emission in the combustion systems (Heydari Gorji, 2009a, 2009b) The advantage of the LM over solid (organic or inorganic) ... to the environmental problem of increasing levels of carbon dioxide in the atmosphere and the accompanying global warming The chemical transformation of carbon dioxide also makes possible the...

Ngày tải lên: 28/06/2014, 17:20

... using a leaf area weighted sum of the rate of water use in all subsections of the tree (determined by multiplying the average transpiration rate for all matrix points in the subsection by the ... estimated as the transpiration and net photosynthesis rate of the mean individual tree in each size class multiplied by the number of trees per ground area in the class, and then by integrating over ... such as thinning will reduce the leaf area of the stand but not the clumping of foliage in the crown and self-shading Spruce trees with their strong apical control are less able to exploit the patchy...

Ngày tải lên: 08/08/2014, 14:22

... submerged in a tank containing cooled water Relative humidity of the air was maintained between 70 and 90% by bubbling air into a water flask maintained at the temperature of the desired dew point ... sun phenotypes of these their species from the point of view of photosynthetic activity However, studying only photosynthetic activity to be insufficient to determine the degree of shade tolerance ... fully developed leaves The mean size of the seedlings used in photosynthesis measurements is shown in table II The measurements of net photosynthesis carried out in the laboratory on attached...

Ngày tải lên: 08/08/2014, 19:21

... which the main branches grew After the end of July, 62% of the enriched plants ceased growth as compared with 37% of the controls The early onset of yellowing and the stopped terminal bud growth indicates ... During the two st wk, the C0 concentration in the chamber was maintained at 330 ppm It was then increased to 660 ppm for another wk period C0 enrichment increased net C0 uptake by about 20% during ... that the root biomass of -enriched C0 plants was 69% heavier than roots of the control plants The increase was statistically significant The shoot was 22% lighter (P>95%) (P>80%) Consequently, the...

Ngày tải lên: 09/08/2014, 04:20

... but there were no differences of the parameter estimates between the treatments (P < 0.05) Typical values were: A 142-160 mm, b 5.7-6.9, k 0.13-0.15 d-! The point of inflexion, where half of the ...

Ngày tải lên: 09/08/2014, 04:20