Chemical Concentration and Spatial Uniformity of a Premixing In-Line Injection System Attached to a Variable-Rate Orchard Sprayer

2021 ◽  
Vol 64 (6) ◽  
pp. 1977-1987
Author(s):  
Zhihong Zhang ◽  
Heping Zhu ◽  
Zhiming Wei ◽  
Ramon Salcedo
Keyword(s):  
Spatial Distribution ◽  
Duty Cycle ◽  
Spray Deposition ◽  
Injection System ◽  
List Type ◽  
Variable Rate ◽  
Chemical Concentration ◽  
Fluorescent Tracer ◽  
Distribution Uniformity ◽  
The Mean

HighlightsA newly developed premixing in-line injection system attached to a variable-rate orchard sprayer was evaluated.Tests were conducted to verify the in-line injection system performance using a vertical spray patternator.Concentration accuracy and spatial distribution uniformity were determined with a fluorescent tracer.Uniform spray mixtures were obtained for different spray viscosities and duty cycle combinations.Abstract. Pesticide spray application efficiency is highly dependent on the chemical concentration accuracy and spatial distribution uniformity. In this study, the performance of a newly developed premixing in-line injection system was evaluated when it was attached to a laser-guided, pulse width modulated (PWM), variable-rate orchard sprayer. The chemical concentration accuracy was determined with respect to spray deposition with a fluorescent tracer, and the spatial distribution uniformity was determined with spray deposits at different heights on a vertical spray patternator. Outdoor tests were conducted with 27 combinations of target chemical concentration (1.0%, 1.5%, and 2.0%), viscosity of the simulated pesticide (1.0, 12.0, and 24.0 mPa·s), and various spray outputs manipulated with PWM duty cycles. For each injection loop, the amounts of the chemical concentrate and water discharged into the mixing line were measured separately in response to preset target concentrations. The results showed that the measured concentrations were consistent across the patternator heights, spray viscosities, and duty cycle combinations. For all treatments, the mean absolute percentage error (MAPE) of the measured concentration was 6.96%, indicating that the concentration accuracy of the system was acceptable. The mean coefficient of variation was 3.35%, indicating that the spatial distribution uniformity of the system was in the desirable range. In addition, there was little variation in chemical concentration for spray mixtures collected at different heights on the patternator. Thus, the premixing in-line injection system could adequately dispense chemical concentrate and water to produce accurate concentrations and uniform spray mixtures for variable-rate nozzles to discharge to targets. Keywords: Environment protection, Precision pesticide application, Laser-guided sprayer, Tank mixture disposal, Specialty crop.

A CO2 Injection System Inside an Open-Top Chamber Enclosing Mature Field-Grown Grapevines: Design and Performance

2018 ◽  
Vol 61 (4) ◽  
pp. 1231-1239
Author(s):  
Mahabubur R. Mollah ◽  
Dale J. Unwin ◽  
Glenn J. Fitzgerald ◽  
Everard J. Edwards
Keyword(s):  
Spatial Distribution ◽  
Carbon Dioxide Concentration ◽  
Heating System ◽  
Performance Criteria ◽  
Injection System ◽  
Co2 Injection ◽  
Open Top Chamber ◽  
Wide Range ◽  
The Mean ◽  
Temporal And Spatial

Abstract. Global mean temperature is likely to rise by more than 2°C by the end of the century and carbon dioxide concentration ([CO2]) is expected to increase from 408 µmol mol-1 in 2018 to 650 µmol mol-1 by 2060-2070. Previous studies and industry experience suggest that there has already been an effect of warmer temperatures on grapevine phenology; harvest dates have advanced and vintages have become shorter over the past 30 years in Australia. In addition, increasing [CO2] in the atmosphere will likely alter grapevine growth, development, and grape quality. Understanding the interactive effects of [CO2] and temperature on grapevines is essential to determine the potential impact of future climate on grape phenology, grape composition, and final wine quality. Open-top chambers (OTC), capable of maintaining air temperature 2°C above ambient throughout the diurnal cycle using an active heating system and fan-assisted air circulation, were established in an experimental vineyard managed to current commercial practice. A system was then developed to elevate atmospheric [CO2] to 650 µmol mol-1 around the grapevines within the OTC. The main engineering goal of the system was to maintain an even temporal and spatial distribution of CO2. Monitoring showed that the mean daytime [CO2] at the center of each OTC varied between 620 and 665 µmol mol-1, maintaining [CO2] at or above 95.4% of the target [CO2] and not exceeding the target by more than 2.3%, meeting the performance criteria of within ±10% of the target concentration. Both the temporal and spatial distributions of [CO2] were more even in heated OTCs than non-heated OTCs. In all heated OTCs, the [CO2] was at or above 90% of the target and within ±10% of the target at all locations assessed (spatial distribution). The mean [CO2] was between 80% and 86% of the target at 40% of locations in OTCs without heating; however, the overall mean [CO2] in the OTCs was 97.5% of the target. The system performed satisfactorily over a wide range of temperatures (20°C to 50°C), with overall standard deviation varying between 85 and 112 µmol mol-1. This indicates that the CO2 injection system showed satisfactory performance in controlling [CO2] at the center of each OTC and providing confidence in the results that will be generated from experiments using the system. On average, the heating system maintained a higher temperature (about 2.0°C in both day and night) than the ambient control plots. Keywords: Australia, CO2 injection in grapevines, Elevated CO2, Grapevines, Open-top chamber, Temperature.

Hardware and Software Design for Premixing In-Line Injection System Attached to Variable-Rate Orchard Sprayer

2020 ◽  
Vol 63 (4) ◽  
pp. 823-821
Author(s):  
Zhihong Zhang ◽  
Heping Zhu ◽  
Chengsong Hu
Keyword(s):  
User Interface ◽  
Graphical User Interface ◽  
Touch Screen ◽  
Environmental Stewardship ◽  
Injection System ◽  
List Type ◽  
Variable Rate ◽  
Spray Application ◽  
Injection Line ◽  
Buffer Tank

.HighlightsA premixing in-line injection system was designed as a retrofit attachment to a laser-guided variable-rate orchard sprayer.A graphical user interface with touchscreen functions was incorporated into the system to facilitate field applications.Preliminary tests demonstrated that simulated pesticide and water could be accurately dispensed and discharged separately into the injection line and mixed well in the buffer tank.This premixing in-line injection system has great potential to further reduce pesticide waste and improve environmental stewardship for conventional and precision variable-rate sprayers.Abstract To eliminate the problems associated with leftover tank mixture in pesticide applications, a premixing in-line injection system was designed as an attachment to a laser-guided variable-rate orchard sprayer. The primary components of the system consisted of a chemical metering pump, a water pump, a two-stage static mixer, a premixing tank, a buffer tank, an electric shut-off valve, a chemical container, electronic control boards, a graphical user interface, and an embedded computer with a touch screen. Liquid level sensors were mounted in all tanks and the chemical container to control the fluid discharge and prevent overflows. The graphical user interface on the touch screen was designed for operators to communicate with the system and monitor the system status. During spray applications, the system performed with automatic loops in dispensing, mixing, and transferring the desired amounts of water and chemical concentrates to maintain the spray mixture at a constant concentration for use with variable-rate nozzles. The system was rinsed automatically when the spray application task was completed. Test results showed that simulated pesticide and water could be accurately delivered into the injection line and could be mixed well in the buffer tank before the spray mixture was discharged to the nozzles. The premixing in-line injection system is a potential technique to further reduce pesticide waste and improve environmental stewardship for both conventional and precision variable-rate orchard sprayers. Keywords: Automation, Environmental protection, Intelligent sprayer, Pesticide spray application, Precision agriculture, Tank mixture leftover.

THE EXTRACTION OF PROLACTIN FROM HUMAN PITUITARY GLANDS

1965 ◽  
Vol 49 (1) ◽  
pp. 1-16 ◽  
Author(s):  
M. Apostolakis
Keyword(s):  
Growth Hormone ◽  
Pituitary Gland ◽  
List Type ◽  
Distilled Water ◽  
Hormone Activity ◽  
Isoelectric Precipitation ◽  
Human Pituitary ◽  
Pituitary Glands ◽  
Prolactin Content ◽  
The Mean

ABSTRACT A method for the extraction of prolactin from human pituitary glands is described. It is based on acetone drying, distilled water extraction, acetone and isoelectric precipitation. Two main products are obtained: Fraction R8 with a mean prolactin activity of 12.2 IU/mg and fraction U8 with a mean prolactin activity of 8.6 IU/mg. The former fraction does not contain any significant gonadotrophin activity and the latter contains on an average 50 HMG U/mg. In both cases contamination with ACTH and MSH is minimal. The growth hormone activity of both these fractions is low. It is postulated that in man too, prolactin and growth hormone are two distinct hormones. A total of 1250 human pituitary glands have been processed by this method. The mean prolactin content per pituitary gland has been found to be 73 IU.

IMMUNOREACTIVE GROWTH HORMONE IN PLASMA AND URINE IN JUVENILE DIABETICS BEFORE AND DURING INITIAL INSULIN TREATMENT

1974 ◽  
Vol 75 (1) ◽  
pp. 50-63 ◽  
Author(s):  
Kristian F. Hanssen
Keyword(s):  
Growth Hormone ◽  
Insulin Treatment ◽  
Juvenile Diabetes ◽  
Control Group ◽  
List Type ◽  
Newly Diagnosed ◽  
Renal Tubular Reabsorption ◽  
Juvenile Diabetics ◽  
The Mean ◽  
Renal Tubular

ABSTRACT Twenty newly diagnosed, but as yet untreated patients of both sexes with classical juvenile diabetes were investigated by determining the mean plasma immunoreactive growth hormone (IRHGH) and urinary IRHGH for a 24 hour period before and during initial insulin treatment. The plasma IRHGH was significantly higher (0.05 > P > 0.01) before than during initial insulin treatment. During initial insulin treatment, the mean plasma IRHGH was significantly higher (0.01 > P > 0.001) than in a control group. The urinary IRHGH was significantly higher (0.01 > P > 0.001) before than during insulin treatment. The increased urinary IRHGH observed before insulin treatment is thought to be partly due to a defective renal tubular reabsorption of growth hormone. No significant correlation was found between the mean blood sugar and plasma or urinary IRHGH either before or during insulin treatment.

CHROMATOGRAPHY OF THE 17-KETOGENIC STEROIDS IN THE DIAGNOSIS AND CONTROL OF CONGENITAL ADRENAL HYPERPLASIA

1960 ◽  
Vol XXXIII (II) ◽  
pp. 230-250 ◽  
Author(s):  
Eileen E. Hill
Keyword(s):  
Congenital Adrenal Hyperplasia ◽  
List Type ◽  
Adrenal Hyperplasia ◽  
Normal Children ◽  
Paediatric Practice ◽  
The Mean ◽  
Cortisone Therapy ◽  
And Control ◽  
Clinical Problems ◽  
Stimulation Of

ABSTRACT A method for the fractionation of the urinary 17-ketogenic steroids with no oxygen grouping at C11 and those oxygenated at C11, is applied to the clinical problems of congenital adrenal hyperplasia. In normal children the mean ratio of the non-oxygenated to oxygenated steroids is 0.24. In childrern with congenital adrenal hyperplasia the ratio is 2.3. The reason for this difference in ratio is discussed. The changes in ratio found under stimulation of the adrenal gland with exogenous or endogenous corticotrophin and the suppression with cortisone therapy are studied. This test can be applied to isolated samples of urine, a major advantage in paediatric practice, and can be carried out in routine laboratories. It is found to be reliable in the diagnosis and sensitive in the control of congenital adrenal hyperplasia.

Abstract 3016: Spirituality and Medication Adherence in Older African American Adults Diagnosed with Hypertension: A Qualitative Study

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Lisa M Lewis
Keyword(s):  
African American ◽  
Medication Adherence ◽  
Qualitative Study ◽  
Antihypertensive Medication ◽  
Demographic Data ◽  
Patient Treatment ◽  
List Type ◽  
Medication Regimen ◽  
Antihypertensive Medications ◽  
The Mean

Background : Medication adherence (ADH) is key to decreasing hypertension (HTN)-related morbidity and mortality in older African-American (AA) adults. However, older AA adults have poorer ADH to prescribed antihypertensive medications when compared to their younger and Caucasian-American counterparts. Patient beliefs and cultural concepts about their medications influence their medication ADH. An important cultural concept in this regards is spirituality, which is a significant resource in the AA community. Thus, the purpose of this qualitative study was to explore the role of spirituality in ADH to antihypertensive medications for older AA adults. Methods: Older AA adults who were members of a Program of All Inclusive Care for the Elderly (PACE) and who were (a) diagnosed with HTN; (b) prescribed at least one antihypertensive medication; (c) self-identified as African-American or Black; and (d) self-identified as spiritual completed one in-depth individual face-to-face in this qualitative descriptive study informed by grounded theory. Demographic data were also collected. Results : Twenty-one PACE members completed the study. All of the participants were female. The mean age of participants was 73 years with most completing high school (67%). The mean HTN diagnosis was16.7 years and mean number of prescriptions for antihypertensives was 3.3. Participants indicated that their spirituality was used in a collaborative process with formal health care to manage their ADH to antihypertensive medications. This process was identified as Partnering with God to Manage My Medications. Partnering with God to Manage My Medications indicated that the PACE members acknowledged personal responsibility for adhering to their antihypertensive medication regimen but used their spirituality as a resource for making decisions to remain adherent; coping with medication side effects; and increasing their self-efficacy to deal with barriers to ADH . Conclusions : Spirituality played a positive role in medication adherence for the PACE members. Incorporating individual beliefs, such as spirituality, into patient treatment for HTN may capitalize on their inner resources for medication ADH and demonstrates culturally appropriate care.

scholarly journals Finding the pattern: online extraction of spatial structure during virtual navigation

2019 ◽  
Author(s):  
Kathryn Nicole Graves ◽  
James Antony ◽  
Nicholas Turk-Browne
Keyword(s):  
Spatial Distribution ◽  
Animal Behavior ◽  
Virtual Water ◽  
Single Session ◽  
Statistical Knowledge ◽  
Navigation Patterns ◽  
The Mean ◽  
Online Extraction ◽  
Human Participants ◽  
The Individual

While navigating the world, we pick up on patterns of where things tend to appear. According to theories of memory and studies of animal behavior, knowledge of these patterns emerges gradually over days or weeks, via consolidation of individual navigation episodes. Here we discover that navigation patterns can also be extracted online, prior to the opportunity for offline consolidation, as a result of rapid statistical learning. Human participants navigated a virtual water maze in which platform locations were drawn from a spatial distribution. Within a single session, participants increasingly navigated through the mean of the distribution. This behavior was better simulated by random walks from a model with only an explicit representation of the current mean, compared to a model with only memory for the individual platform locations. These results suggest that participants rapidly summarized the underlying spatial distribution and used this statistical knowledge to guide future navigation.

On random genetic drift in a subdivided population

1968 ◽  
Vol 5 (02) ◽  
pp. 314-333
Author(s):  
Edward Pollak
Keyword(s):  
Random Sampling ◽  
Joint Distribution ◽  
The Other ◽  
Small Positive Number ◽  
List Type ◽  
Type Number ◽  
Random Genetic Drift ◽  
Subdivided Population ◽  
Haploid Population ◽  
The Mean

Summary Generations are assumed to be non-overlapping. We consider a haploid population divided into K parts, each of which contain N adults in any generation. These are obtained by a random sampling of the offspring of the previous generation. We assume that the probability of an adult offspring of an individual in one subpopulation being in some other subpopulation is the same small positive number, no matter what two subpopulations are considered. If the population initially has individuals of two types, A and a, it is of interest to study approximations, if n is large, to (1) the rate at which A or a is lost between generations n-1 and n, (2) the probability that A and a are still present in generation n, (3) the joint distribution of frequencies of A in the subpopulations. A solution is given for the first problem. It is found that if the mean number of migrants per generation from one subpopulation to another is at least as large as 1, the population behaves almost as if it were not subdivided. But if this number is considerably less that 1, then the rate at which one or the other gene is lost is slower than in an undivided population. The other two problems are discussed for K = 2.

Spatial Distribution of Spray Deposition from an Air-Carrier Sprayer

1989 ◽  
Vol 32 (3) ◽  
pp. 0807-0811 ◽  
Author(s):  
D. K. Giles ◽  
M. J. Delwiche ◽  
R. B. Dodd
Keyword(s):  
Spatial Distribution ◽  
Spray Deposition ◽  
Air Carrier
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