scholarly journals GROWTH RATE DISPERSION (GRD) OF THE (010) FACE OF BORAX CRYSTALS IN FLOWING SOLUTION

2010 ◽  
Vol 4 (3) ◽  
pp. 145-148
Author(s):  
Suharso Suharso ◽  
Gordon Parkinson ◽  
Mark Ogden
Keyword(s):  
Growth Rate ◽  
Aqueous Solutions ◽  
Normal Distribution ◽  
Flow Rate ◽  
Growth Rates ◽  
Experimental Conditions ◽  
Solution Flow ◽  
Flow Rates ◽  
Growth Rate Distribution ◽  
Flowing Solution

The growth rates of borax crystals from aqueous solutions in the (010) direction at various flow rates were measured. The observed variations of the growth rate can be represented by a normal distribution.  It was found that there is no correlation between growth rate distribution and solution flow under these experimental conditions.   Keywords: Growth rate dispersion (GRD), borax, flow rate

scholarly journals GROWTH RATE DISTRIBUTION OF BORAX SINGLE CRYSTALS ON THE (001) FACE UNDER VARIOUS FLOW RATES

2010 ◽  
Vol 6 (1) ◽  
pp. 16-19
Author(s):  
Suharso Suharso
Keyword(s):  
Growth Rate ◽  
Single Crystals ◽  
Flow Rate ◽  
Flow Rates ◽  
Rate Distribution ◽  
Spss Software ◽  
Log Normal ◽  
Growth Rate Distribution ◽  
Log Normal Distribution

The growth rates of borax single crystals from aqueous solutions at various flow rates in the (001) direction were measured using in situ cell method. From the growth rate data obtained, the growth rate distribution of borax crystals was investigated using Minitab Software and SPSS Software at relative supersaturation of 0807 and temperature of 25 °C. The result shows that normal, gamma, and log-normal distribution give a reasonably good fit to GRD. However, there is no correlation between growth rate distribution and flow rate of solution.   Keywords: growth rate dispersion (GRD), borax, flow rate

scholarly journals Head lettuce production and nutrition in relation to nutrient solution flow

2020 ◽  
Vol 38 (1) ◽  
pp. 21-26
Author(s):  
Cleiton Dalastra ◽  
Marcelo CM Teixeira Filho ◽  
Marcelo R da Silva ◽  
Thiago AR Nogueira ◽  
Guilherme Carlos Fernandes
Keyword(s):  
Nutrient Solution ◽  
Flow Rate ◽  
Nutrient Accumulation ◽  
Solution Flow ◽  
Flow Rates ◽  
Hydroponic System ◽  
Optimum Flow Rate ◽  
Technical Performance ◽  
Use Efficiency ◽  
Optimum Flow

ABSTRACT The optimum flow rate of nutrient solution in hydroponic system can better nourish the crops, allowing healthy and faster growth of lettuce. However, flow also interferes with electric power consumption, so further researches are necessary, mainly on the effect of flow rate, nutrient accumulation and lettuce production. In this context, the aim of this study was to evaluate nutrition and production of head lettuce in relation to the nutrient solution flow in NFT hydroponic system. The treatments consisted of nutrient solution application at the flow rates 0.5; 1; 2, and 4 liters per minute in each cultivation channel. Five replicates per treatment consisted of 15 plants each. The flow in hydroponic systems to produce head lettuce alters the technical performance of the crop. Due to the greater nutrient accumulation in shoot and use efficiency of these elements, the highest production (g/plant) of head lettuce was obtained with a flow rate of 1 L/min of the nutrient solution.

Quantitative In Situ Growth Measurements of Chlorine-Activated Homoepitaxial Diamond Cvd

1994 ◽  
Vol 349 ◽  
Author(s):  
Chenyu Pan ◽  
John L. Margrave ◽  
Robert H. Hauge
Keyword(s):  
Growth Rate ◽  
Substrate Temperature ◽  
Growth Rates ◽  
Diamond Growth ◽  
Flow Rates ◽  
Temperature Range ◽  
Quantitative Studies ◽  
Growth Activation ◽  
Lower Temperature

ABSTRACTIn situ quantitative studies of the effects of substrate temperature, methane and chlorine flow rates on homoepitaxial diamond growth rates on (110) surfaces in a chlorine-activated diamond CVD reactor have been carried out using a Fizeau interferometer. The temperature dependence of diamond growth rates was found to display three distinct growth activation energies, ranging from 9±2 kcal/mol in the substrate temperature of 750-950°C, to 3.2±0.2 kcal/mol in the temperature range of 300-650°C, followed by 1.2±0.2 kcal/mol in the temperature range of 102-250°C. Atomic hydrogen is believed to be the dominant activating species in the highest temperature range, and atomic chlorine is believed to be the dominant species in the lower temperature regions. Studies of the methane flow effect on diamond growth rates revealed a linearity, indicating that the diamond growth rate was of the first order in methane flows. Diamond growth rates were also found to increase linearly with the chlorine flow. At high chlorine flow rates, however, an accelerated diamond growth rate was observed. Discussion is given to explain the observed results.

Relationship between growth rate and undercooling in Pt-added Y1Ba2Cu3O7−x

1996 ◽  
Vol 11 (5) ◽  
pp. 1114-1119 ◽  
Author(s):  
A. Endo ◽  
H. S. Chauhan ◽  
Y. Nakamura ◽  
Y. Shiohara
Keyword(s):  
Experimental Data ◽  
Growth Rate ◽  
Parabolic Equation ◽  
Growth Rates ◽  
Crystal Size ◽  
Experimental Conditions ◽  
Seed Crystals ◽  
Cooling Method ◽  
Increasing Trend ◽  
Good Agreement

Y1Ba2Cu307−x (Y123) crystals were grown by two different methods, the constant undercooling solidification and the continual cooling method, with top seeding by Sm123 seed crystals in order to investigate a relationship between undercooling (ΔT) and a growth rate (R). The crystals of Y123 with a sharp faceted interface, which consisted of {100} and {001} faces, grew epitaxially from the seed. It was found that the growth rates of {100} face (Ra) and that of {001} face (Rc) showed an increasing trend with increasing ΔT, and Rc was faster than Ra within these experimental conditions, ΔT < 20 K. The relation between R and ΔT follows the parabolic equation, viz. Ra ∝ ΔT1.9 and Rc ∝ ΔT1.3 for {100} and {001} faces, respectively. The simulated crystal size using the R and ΔT relations obtained from the constant undercooling method showed good agreement with experimental data by the continual cooling.

scholarly journals Effect of Nutrient Solution Flow Rate on Hydroponic Plant Growth and Root Morphology

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1840 ◽  
Author(s):  
Bateer Baiyin ◽  
Kotaro Tagawa ◽  
Mina Yamada ◽  
Xinyan Wang ◽  
Satoshi Yamada ◽  
...  
Keyword(s):  
Plant Growth ◽  
Root Growth ◽  
Surface Area ◽  
Flow Rate ◽  
Root Morphology ◽  
Root Surface ◽  
Solution Flow Rate ◽  
Root Surface Area ◽  
Solution Flow ◽  
Flow Rates

Crop production under hydroponic environments has many advantages, yet the effects of solution flow rate on plant growth remain unclear. We conducted a hydroponic cultivation study using different flow rates under light-emitting diode lighting to investigate plant growth, nutrient uptake, and root morphology under different flow rates. Swiss chard plants were grown hydroponically under four nutrient solution flow rates (2 L/min, 4 L/min, 6 L/min, and 8 L/min). After 21 days, harvested plants were analyzed for root and shoot fresh weight, root and shoot dry weight, root morphology, and root cellulose and hemicellulose content. We found that suitable flow rates, acting as a eustress, gave the roots appropriate mechanical stimulation to promote root growth, absorb more nutrients, and increase overall plant growth. Conversely, excess flow rates acted as a distress that caused the roots to become compact and inhibited root surface area and root growth. Excess flow rate thereby resulted in a lower root surface area that translated to reduced nutrient ion absorption and poorer plant growth compared with plans cultured under a suitable flow rate. Our results indicate that regulating flow rate can regulate plant thigmomorphogenesis and nutrient uptake, ultimately affecting hydroponic crop quality.

scholarly journals Estimation of Saturation Flow Rates at Signalized Intersections

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Chang-qiao Shao ◽  
Xiao-ming Liu
Keyword(s):  
Normal Distribution ◽  
Flow Rate ◽  
Goodness Of Fit ◽  
Estimation Method ◽  
Fundamental Parameter ◽  
Goodness Of Fit Test ◽  
Flow Rates ◽  
Average Value ◽  
Saturation Flow Rate ◽  
Saturation Flow

The saturation flow rate is a fundamental parameter to measure the intersection capacity and time the traffic signals. However, it is revealed that traditional methods which are mainly developed using the average value of observed queue discharge headways to estimate the saturation headway might lead to underestimate saturation flow rate. The goal of this paper is to study the stochastic nature of queue discharge headways and to develop a more accurate estimate method for saturation headway and saturation flow rate. Based on the surveyed data, the characteristics of queue discharge headways and the estimation method of saturated flow rate are studied. It is found that the average value of queue discharge headways is greater than the median value and that the skewness of the headways is positive. Normal distribution tests were conducted before and after a log transformation of the headways. The goodness-of-fit test showed that for some surveyed sites, the queue discharge headways can be fitted by the normal distribution and for other surveyed sites, the headways can be fitted by lognormal distribution. According to the queue discharge headway characteristics, the median value of queue discharge headways is suggested to estimate the saturation headway and a new method of estimation saturation flow rates is developed.

Recrystallization of Caffeine Using Supercritical Carbon Dioxide as Antisolvent

2009 ◽  
Vol 4 (5) ◽  
Author(s):  
Joel Augusto da Silva Romero ◽  
Thiago Leandro Souza ◽  
Guilherme Sunehiro ◽  
Marcos Hiroyuki Kunita ◽  
Nanci Pinheiro
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Flow Rate ◽  
Solution Flow Rate ◽  
Organic Solution ◽  
Scanning Calorimetry ◽  
Experimental Conditions ◽  
Solution Flow ◽  
Amorphous Particles ◽  
Supercritical Carbon

The supercritical antisolvent (SAS) process has been widely used to obtain many types of crystalline and amorphous particles of polymers and drugs. In this process, solute particles precipitate from an organic solution when it is sprayed into a compressed antisolvent continuum. The antisolvent is miscible with the organic solvent, but immiscible with the solute. The objective of this work was to investigate the application of supercritical carbon dioxide as antisolvent for the recrystallization of caffeine; a compound largely employed in pharmaceutical and food industries. The carbon dioxide was pressurized at 100bar and the solution was injected into a precipitation chamber, thereby inducing its supersaturation and particle precipitation. The effect of process parameters such as initial concentration of caffeine in the organic solution (3, 5 and 10mg/mL), organic solution flow rate (3mL/min), concentration of CO2 (96 and 98mol%), drying flow rate (990mL/min) and pressure gradient between the precipitation chamber and the exit of the sprayer tube (110 and 220bar) on the solid state properties of caffeine was investigated. The pressure (100bar) and temperature (60oC) of the precipitation chamber were kept constant. The results showed a great difference between the processed and unprocessed samples. In all experimental conditions a reduction in caffeine mean particle size was observed, with length ranging from 0.6 to 168.3?m and width from 0.1 to 12.7?m, compared to the mean size of unprocessed caffeine particles (16.6 to 214.4?m in length and 7.1 to 131.2?m in width). This fact was confirmed by differential scanning calorimetry (DSC), where the precipitated particles presented lower fusion enthalpy than the unprocessed ones. Smaller crystal needles (0.3?m to 0.4?m) were obtained with crystallization at the lowest caffeine concentration in the presence of 98mol% CO2.

Adsorption/Retention of Petroleum Sulfonates in Berea Cores

1977 ◽  
Vol 17 (05) ◽  
pp. 353-357 ◽  
Author(s):  
J.H. Bae ◽  
C.B. Petrick
Keyword(s):  
Adsorption Isotherm ◽  
Aqueous Solutions ◽  
Flow Rate ◽  
Oil Recovery ◽  
Reservoir Rock ◽  
Equivalent Weight ◽  
Flow Rates ◽  
The Core ◽  
Petroleum Sulfonate ◽  
Pass Through

Abstract A series of petroleum sulfonate adsorption experiments was conducted in 2-in.-diameter, 2-ft-long Berea cores initially saturated with 1-percent NaCl brine. The sulfonates used had an average equivalent weight of 430 with a broad equivalent-weight distribution. The concentration ranged from 0.01 to 8 per cent. The flow rates investigated ranged from 2 to 36 ft/D. Adsorption was determined either from analysis of the effluent concentrations or by extraction of sulfonates from the core. The physical properties of the solutions were also measured. In several tests, Na2CO3 was used as a sacrificial chemical, either in a preflood or added to the sulfonate solution. It was found that at certain concentrations, apparent adsorption is dependent on the flow rate. The sulfonate adsorption isotherm was found to pass through a maximum. The value of the pass through a maximum. The value of the adsorption maximum and the concentration at which it occurs are also dependent on the flow rate. The time required for adsorption equilibrium was found to increase with increasing sulfonate concentration. A sacrificial chemical reduced the sulfonate adsorption. However, sulfonate adsorption increased gradually with time. Adsorption tests should be conducted at realistic flow rates. Introduction One of the major problems in surfactant flooding is the adsorption of surfactants on the reservoir rock. If adsorption is excessive, surfactants are depleted rapidly from the slug as it moves through the reservoir; consequently, it loses the ability to lower the oil-water interfacial tension. Thus, the magnitude of adsorption is an important technical as well as economic parameter. It has been reported that the adsorption of petroleum sulfonates is selective. The high-equivalent-weight sulfonates are adsorbed preferentially whole low-equivalent-weight preferentially whole low-equivalent-weight sulfonates show almost no adsorption. Most of the adsorbed sulfonates had an equivalent weight of 500 or more. This type of fractionation was considered to be the main cause for poor oil recovery in a field pilot test. The literature data on the adsorption of petroleum sulfonates from aqueous solutions indicate petroleum sulfonates from aqueous solutions indicate that there is a maximum in the adsorption isotherm. Furthermore, the adsorption of sulfonate is reduced significantly when sacrificial chemicals are used. The experimental methods used in these measurements differ from one another and, on occasion, the adsorbed sulfonates are defined to be the amount extracted by a solvent after a brine flush. The term "adsorption" is used here rather loosely. Some people prefer the term retention to adsorption since there may be physical retention in a core. The physical retention may or may not exist in a given experiment and detection of it may be very difficult. The objective of this work is to investigate the adsorption phenomenon in dynamic core tests. Several questions are examined: How is the adsorption isotherm related to the general properties of the solution? Do the dynamic test conditions affect the adsorption measurement? Are sacrificial chemicals useful in reducing sulfonate adsorption? EXPERIMENTAL PROCEDURES The petroleum sulfonate used was a blend of sulfonates, TRS 18 and TRS 40 obtained from Witco Chemical Co., and has an average equivalent weight of 430. The equivalent weight ranged from 250 to 650, with about 80 percent ranging from 350 to 550, almost evenly distributed. Isopropyl alcohol was used as a cosolvent at 1/10 of the sulfonate concentration. A 1-percent NaCl brine was used as the aqueous medium. Weight percentage is used throughout this paper. All adsorption tests were conducted at room temperature of 72 degrees F in 2-in.-diameter, 2-ft-long Berea cores saturated with brine. The permeability to brine in all tests was 450 + 25 md. The sulfonate solution was injected continuously into the cores using a positive-displacement pump. The produced fluids were collected in a fraction collector. In most cases, at the end of sulfonate injection, the sulfonate in the core was extracted immediately with a methanol-chloroform mixture. SPEJ P. 353

Simultaneous Absorption of SO2 and NO Using Sodium Chlorate/Urea Absorbent in a Rotating Packed Bed

2014 ◽  
Vol 908 ◽  
pp. 187-190
Author(s):  
Mei Jin ◽  
Guo Xian Yu ◽  
Fang Wang ◽  
Ping Lu
Keyword(s):  
Removal Efficiency ◽  
Flow Rate ◽  
Flue Gas ◽  
Gas Flow ◽  
Packed Bed ◽  
Sodium Chlorate ◽  
Experimental Conditions ◽  
Flow Rates ◽  
Simultaneous Absorption ◽  
Rotating Packed Bed

In this work, simultaneous absorption of SO2and NO from N2-NO-SO2simulated flue gas using sodium chlorate as the additive and urea as the reductant was investigated experimentally in a rotating packed bed. In RPB, various rotational speeds, gas flow rates and liquid flow rates were studied by means of the removal efficiency of SO2and NO. The experimental results showed that the removal efficiency of SO2was higher than 99.00% under various experimental conditions and, at the same time, the removal efficiency of NO exhibited different results under various experimental conditions. The simultaneous NO removal efficiency of 82.45% and the SO2removal efficiency of 99.49% could be obtained under the N2flow rate of 0.5 m3/h, SO2flow rate of 6 mL/min, the NO flow rate of 4 mL/min, the rotational speed of 460 rpm and the absorbent flow rate of 40 L/h.

Metabolic rate and thermal stability during honeybee foraging at different reward rates

2001 ◽  
Vol 204 (4) ◽  
pp. 759-766 ◽  
Author(s):  
L. Moffatt
Keyword(s):  
Thermal Stability ◽  
Metabolic Rate ◽  
Flow Rate ◽  
Sucrose Solution ◽  
Carbon Dioxide Production ◽  
Metabolic Power ◽  
Solution Flow ◽  
Flow Rates ◽  
Metabolic Heat ◽  
Air Temperatures

During honeybee foraging, the stabilization of thoracic temperature (Tth) at elevated values is necessary to meet the power requirements of flight at different air temperatures (T(a)). To understand how the bee achieves thermal stability at different reward rates, the metabolic rates of undisturbed foraging bees were measured at different T(a) values and different sucrose solution flow rates. Metabolic heat production, calculated from the rate of carbon dioxide production, decreased linearly from 49.7 to 23.4 mW as T(a) increased from 19 to 29 degrees C (sucrose flow rate 1.75 microl × min(−1), 50 % w/w). In contrast, crop load and inspection rate remained constant. Metabolic rate displayed a linear relationship with both T(a) and the logarithm of the flow rate of sucrose solution (range analyzed 0.44-13.1 microl × min(−1), 50 % w/w). Metabolic rate decreased by 3.13+/−0.52 mW (mean +/− s.e.m., N=37) for every 1 degrees C increase in T(a) and increased by 4.36+/−1.13 mW for a doubling in flow rate. These changes in metabolic power output might be used to achieve thermal stability during foraging. It is suggested that the foraging bee might increase its Tth in accordance with the reward rate.

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