scholarly journals RESISTÊNCIA DE DIFERENTES TIPOS DE TUBOGOTEJADORES AO ENTUPIMENTO POR PRECIPITAÇÃO QUÍMICA DE CÁLCIO

Irriga ◽  
2004 ◽  
Vol 9 (2) ◽  
pp. 115-125 ◽  
Author(s):  
Nildo Da Silva Dias ◽  
Marcus Vinicius A. M. de Oliveira ◽  
Rubens Duarte Coelho
Keyword(s):  
Standard Deviation ◽  
Flow Rate ◽  
Calcium Sulfate ◽  
Operation Time ◽  
Chemical Precipitation ◽  
Drip Line ◽  
Rate Variation ◽  
Trickle Irrigation ◽  
Flow Reduction ◽  
Medium Flow

RESISTÊNCIA DE DIFERENTES TIPOS DE TUBOGOTEJADORES AO ENTUPIMENTO POR PRECIPITAÇÃO QUÍMICA DE CÁLCIO   Nildo da Silva Dias1; Marcus Vinicius A. M. de Oliveira2; Rubens Duarte Coelho11Departamento de Engenharia Rural, Escola Superior de Agricultura Luiz de Queiroz, Universidade de São Paulo, Piracicaba, SP,  [email protected] de Recursos Naturais, Faculdade de Ciências Agronômicas, Universidade Estadual Paulista, Botucatu, SP    1 RESUMO  Com o objetivo de avaliar a susceptibilidade de tubogotejadores ao entupimento por precipitados químicos à base de sulfato de cálcio, foi desenvolvido um experimento no Laboratório de Irrigação da Escola Superior de Agricultura “Luiz de Queiroz”. Foram utilizados três tipos de tubogotejadores não autocompensáveis (Carbo Drip 2,30 L h-1 – T1; Hydro Gol, 2,00 L h-1 – T2 e Typhoon 1,70 L h-1 – T3) instalados em uma bancada, com 6 m de comprimento x 1,3 m de largura e 1,45 de altura, com cinco segmentos de linhas para cada tipo de tubogotejador. Verificou-se a influência causada pela indução forçada de precipitação química no coeficiente de variação de vazão (CVq), no desvio padrão, na vazão média e na taxa de redução de vazão dos emissores. Os resultados mostram que o tempo de funcionamento dos emissores influiu no CVq devido à ocorrência de obstruções tanto parcial como total. A obstrução do orifício de saída do tubogotejadores, decorrente do tempo de funcionamento, contribui para o aumento dos coeficientes de variação, constituindo um problema sério da irrigação localizada, pela desuniformidade de vazão causada.  UNITERMOS: Irrigação localizada, obstrução de emissores, sulfato de cálcio.   DIAS, N. da S.; OLIVEIRA, M. V. A. M. de; COELHO, R. D. CLOGGING RESISTANCE OF DIFFERENT DRIP LINE FOR CALCIUM CHEMICAL PRECIPITATION   2 ABSTRACT  To evaluate the drip line clogging susceptibility to chemical precipitate of calcium sulfate, a study was carried out in the Irrigation Laboratory of the Superior School of Agriculture " Luiz de Queiroz " (USP/ESALQ). Three different drip lines (Carbo Drip 2,30 L h-1 - T1; Hydro Gol, 2,00 L h-1 - T2 and Typhoon 1,70 L h-1 - T3)were used and installed in a 6 m long x 1.3 m wide x 1.45 m high dench. The influence caused by the chemical precipitation in the flow variation coefficient (CVq), standard deviation, medium flow and rate flow reduction of the emitters was verified. The results showed that the operation time of the emitters influences on CVq, due to occurrence of partial and total obstructions of emitters. Dripper exit obstruction due to operation time contributes to the increase of the flow rate variation coefficients, resulting in a serious problem in trickle irrigation.  KEYWORDS: Trickle irrigation, emitter clogging, calcium sulfate

COMPARISON OF OPTIONS FOR THE HEAT DISTRIBUTION NETWORK OF THE RESIDENTIAL NEIGHBORHOOD

2021 ◽  
pp. 17-25
Author(s):  
O. Aleksakhin ◽  
S. Yena ◽  
O. Hordiienko ◽  
V. Novikov ◽  
D. Tsemokh
Keyword(s):  
Flow Rate ◽  
Distribution Network ◽  
Water Flow Rate ◽  
Heating System ◽  
Heat Losses ◽  
Rate Variation ◽  
Outdoor Air ◽  
Heat Network ◽  
Residential Neighborhood ◽  
Medium Flow

The comparison of heat losses by pipelines of an extensive residential neighborhood heating system for two options of the distribution network was carried out for a residential neighborhood in Kharkov. The proposed configuration of the heating network differs from the existing ("basic") one in using of the law of heating medium flow rate variation along the heat pipe length. This law takes into account increased flow rate of heating water through branches at the initial sections of the pipeline. The actual flow rate distribution is approximated by a step function. The difference in the laws of flow rate variation is taken into account by the exponent value. The calculation of heat losses was carried out for underground pipelining in non-accessible tunnels. The temperature of heat line water is taken to be the corresponding to the design outdoor air temperature for heating according to the temperature schedule of the heating network. Specific heat losses by pipelines in heat network sections are considered to be at the standard level for non-accessible tunnels. The soil temperature at the depth of the heat pipe axis is taken equal to 5°C. Heat losses by the structural elements of the heat network are taken into account by a factor of 1.15. The variation of the flow rate and temperature of network water in rated pipeline sections is considered in the analysis.  The water flow rate at the sections was found based on the design thermal loads of connected buildings. It is shown that when choosing the configuration of the distribution network of the heating system of a group of buildings, preference should be given to the option with a lower value of the exponent in the equation for heating medium flow rate variation along the length of the main line of the network. For extensive heating networks, this can be achieved by connecting as many buildings as possible to the heating network sections close to a heat supply station. An increase in the network water flow rate through the branches at the initial sections of the pipeline ensures a decrease in heat losses by the network pipelines. For the considered part of a residential neighborhood, the decrease in heat loss at the design outdoor air temperature for heating is 5.5 %.

On an enclosed-design of chain drives for sucker-rod pumping units used in low and medium flow-rate wells

2018 ◽  
pp. 11-17
Author(s):  
V.M. Valovsky ◽  
◽  
K.V. Valovsky ◽  
I.G. Shamsutdinov ◽  
N.V. Fedoseenko ◽  
...  
Keyword(s):  
Flow Rate ◽  
Sucker Rod ◽  
Medium Flow ◽  
Pumping Units ◽  
Chain Drives

Radon removal by aeration: observations on testing, installation and maintenance of domestic treatment units

2009 ◽  
Vol 9 (4) ◽  
pp. 469-475
Author(s):  
T. Turtiainen
Keyword(s):  
Water Quality ◽  
Water Flow ◽  
Removal Efficiency ◽  
Flow Rate ◽  
Test Protocol ◽  
Household Water ◽  
Medium Flow ◽  
Removal Efficiencies ◽  
Frequent Sampling

Radon is one of the contaminants that sometimes impair the water quality of wells, especially those drilled in bedrock. Domestic radon removal units based on aeration have been commercially available for more than ten years. In order to determine how effectively these units remove radon a new test protocol applying frequent sampling while letting 100 litres of water flow, was developed. This way, removal efficiencies can be more accurately calculated and possible malfunctions detected. Seven models of domestic aerators designed for removing radon from household water were tested. The aerators were based on diffused bubble aeration, spray aeration or jet aeration. The average removal efficiencies for 100 litres with a medium flow rate were 86–100% except for a unit that circulated the aerated water back to the well that had removal efficiency of 80% at the maximum. By conducting a questionnaire study usual problems related to the aeration units were localized and recommendations on maintenance and installation are given accordingly.

Optimization of the Ratio of ω-6 Linoleic and ω-3 α-Linolenic Fatty Acids of Hemp Seed Oil with Jackknife and Bootstrap Resampling

2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Vibha Devi ◽  
Shabina Khanam
Keyword(s):  
Fatty Acids ◽  
Standard Deviation ◽  
Flow Rate ◽  
Seed Oil ◽  
Cannabis Sativa ◽  
Bootstrap Resampling ◽  
Hemp Seed ◽  
Solvent Flow Rate ◽  
The Mean ◽  
Experimental Runs

Abstract In the present work, supercritical fluid extraction (SFE) of hemp (Cannabis sativa) seed oil at various ranges of SFE parameters is performed. These parameters and respective ranges are temperature (40–80) °C, pressure (200–350) bar, solvent (CO2) flow rate (5–15) g/min, particle size (0.43–1.02) mm and amount of co-solvent (ethanol) (0–10) % of solvent flow rate. Central composite design (CCD) suggests 32 experimental runs to perform through SFE. The obtained oil is analysed through gas chromatography to identify its fatty acids concentrations. The ratio of ω-6 linoleic and ω-3 α-linolenic fatty acids (ω-6/ω-3) is optimized through CCD to obtain the desired amount of 3:1 as this ratio is highly preferred for various health benefits. Ratio of ω-6/ω-3 is obtained in the range from 2.11 to 3.06:1 for all experimental runs. The effect of SFE parameters on this ratio is investigated. Further, cross-validation is peformed on the experimental data obtained for the concentrations of both fatty acids by jackknife and bootstrap resampling to authenticate the obtained data. Small value of standard deviation (~1), less standard error of the mean (SEM) (<0.8) and less variance coefficient (<0.11) confirms the validity of the obtained data. All the estimators’ values such as standard deviation, variance coefficients and SEM are observed in 95 % of confidence intervals.

scholarly journals Effect of trickle irrigation on root development of the wet bulb and 'pera' orange tree yield in the state of São Paulo, Brazil

2011 ◽  
Vol 31 (6) ◽  
pp. 1096-1103 ◽  
Author(s):  
Regina C. de M Pires ◽  
Décio Bodine Junior ◽  
Emílio Sakai ◽  
Heloísa L Villar ◽  
Tonny J. A. da Silva ◽  
...  
Keyword(s):  
Root System ◽  
Root Development ◽  
Drip Line ◽  
The State ◽  
Trickle Irrigation ◽  
Yield And Quality ◽  
Orange Orchard ◽  
Orange Trees ◽  
Cleopatra Mandarin

The aim of this study was to evaluate the effect of different microirrigation designs on root system distribution in wet bulb region, orange orchard yield and quality of orange fruits. The experiment was installed as random blocks with five treatments and four replicates in an orchard of 'Pêra' orange trees grafted on 'Cleopatra' mandarin rootstock. The treatments consisted of: one drip line (T1), two drip lines (T2), four drip lines (T3) per planting row, microsprinkler irrigation (T4) and without irrigation (T5). Irrigation treatments favored yield and ºBrix. The treatment with a single drip line (T1) showed the greatest quantity of roots in relation to the treatments T2 and T3.

scholarly journals Cast Iron Cooling Rate Variation Using Cooling Channels: A Numerical Approach

2021 ◽  
pp. 29-35
Author(s):  
Olumide Adewole Towoju
Keyword(s):  
Mechanical Properties ◽  
Cast Iron ◽  
Cooling Rate ◽  
Flow Rate ◽  
Numerical Approach ◽  
Cooling Curve ◽  
Rate Variation ◽  
Cooling Fluid ◽  
Cooling Channels ◽  
The Impact

The cooling rate of molten cast iron can make or mar it. The cooling rate plays a significant role in the resulting mechanical properties of cast iron. It determines the grain growth and size. The mechanical properties of cast iron variation along its length are achieved either with the use of different mold materials or by sectioning to ensure varied cooling rates. Mechanical properties can, however, also be varied along its length without any of these adopted methods by the incorporation of cooling channels in the mould. This study seeks to expand the frontier of this concept with the use of different cooling fluids and fluid flow rate, and numerically investigate the impact on the cooling rate of gray cast iron (class 40). The cooling curve for the cast iron was impacted by the use of different cooling fluids with the attainment of the desired mechanical properties with the selection of an appropriate cooling fluid. Also, the flow rate of the cooling fluid has an impact on the cast iron cooling rate.

scholarly journals Simple superphosphate by two-stage acid treatment of phosphate raw materials

2021 ◽  
Vol 939 (1) ◽  
pp. 012057
Author(s):  
D Sherkuziev
Keyword(s):  
Phosphoric Acid ◽  
Flow Rate ◽  
Acid Treatment ◽  
Calcium Sulfate ◽  
Raw Materials ◽  
Production Cycle ◽  
Second Stage ◽  
Additional Input ◽  
Concentrated Solution ◽  
Two Stages

Abstract The distinguishing feature of the proposed flow method before the classical (chamber) method is that the entire production cycle of natural phosphate processing is carried out in two stages. At the first stage, the phosphorite is treated with a stoichiometric flow rate of concentrated sulphuric acid (at least 93%), under conditions of complete decomposition of phosphorite to form phosphoric acid and crystals of anhydrite (calcium sulfate). The reaction temperature is 122 °C. In the second stage, the resulting concentrated solution of phosphoric acid in a mixture with sulphur is involved in a reaction with an additional input of phosphorite, which is the basis for the mechanism of chemical formation of monocalciumphosphate and granulation of superphosphate mass. The processes for neutralizing phosphoric acid on monocalciumphosphate and for granulating the product by coagulation are combined in one apparatus. The drying stage of the product is excluded from the scheme.

Effects of stimulation on steroid output and perfusion medium flow rate in the isolated perfused rat adrenal gland in situ

1986 ◽  
Vol 109 (2) ◽  
pp. 279-285 ◽  
Author(s):  
J. P. Hinson ◽  
G. P. Vinson ◽  
B. J. Whitehouse ◽  
G. M. Price
Keyword(s):  
Flow Rate ◽  
Zona Glomerulosa ◽  
Clear Correlation ◽  
Perfusion Medium ◽  
Flow Rates ◽  
Vascular Elements ◽  
Medium Flow ◽  
High Concentrations ◽  
Adrenal Vasculature

ABSTRACT Using the in-situ, isolated, perfused rat adrenal system, the actions of adrenal stimulants on steroidogenesis and perfusion medium flow rates (under constant perfusion pump conditions) have been studied. In a series of 100 experiments, initial rates of corticosterone output and flow rates were found to be positively correlated, although there was no such relationship between initial rates of aldosterone output and flow rates. Furthermore, in stable perfusion conditions, bolus injections of ACTH increased both flow rate and steroid output in a dose-related manner. In individual experiments there was a clear correlation between corticosterone and flow, but the association between aldosterone secretion rate and flow was less evident. It is possible that this discrepancy arises because of temporal differences in the responses of these two steroids. Flow was also stimulated by dibutyryl cyclic AMP (dbcAMP), with correlations with steroid output similar to ACTH, but the specific zona glomerulosa stimulants angiotensin II amide and potassium ions had, if anything, inhibitory effects on flow, but only at high concentrations. The data suggest that ACTH and dbcAMP evoke specific responses in the adrenal vasculature, resulting in relatively decreased intraglandular vascular resistance. They furthermore suggest that the secretory functions of the inner adrenocortical zones are subject to the additional control of vascular elements in the intact gland. J. Endocr. (1986) 109, 279–285

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