scholarly journals Capability of ground fertiliser placement when spread from fixed wing aircraft

2016 ◽  
Vol 16 ◽  
pp. 191-195
Author(s):  
S.E. Chok ◽  
M.C.E. Grafton ◽  
I.J. Yule ◽  
M.J. Manning
Keyword(s):  
Application Rate ◽  
Differential Rate ◽  
Application Technology ◽  
Variance Test ◽  
Rate System ◽  
Hill Country ◽  
Application Rates ◽  
Accuracy And Precision ◽  
The Mean ◽  
The Difference

Aerial topdressing using differential rate application technology improves fertiliser spreading on hill country farms. However, the system's ability to place fertiliser accurately and precisely within an area needs to be determined. Accuracy was determined by comparing measured and intended application rates. Precision was indicated by the coefficient of variation (CV), which is the standard deviation of the measured application rate over the mean of this rate. Two trials were carried out, where aircraft deposited fertiliser at two application rates and fertiliser was captured using cone-shaped collectors. The average measured application rate for both trials was less than the intended rate. The CV ranged from 35 to 57%, and was lower than CV's from pilot-operated hopper systems (78%). A one-way analysis of variance test found the difference between measured application rate in the high and low application zone was statistically significant. The results indicate work is required to improve the accuracy and precision of the differential rate system, however, the system shows promise. Keywords: differential rate application technology, aerial spreading, fertiliser placement

scholarly journals EVALUATION OF A TETRAHEDRON SPREADER ON A FIXED-WING AIRCRAFT TO INCREASE FERTILISER SPREAD

1984 ◽  
pp. 57-64
Author(s):  
J.F. Maber ◽  
J.F.L. Charlton
Keyword(s):  
Distribution Pattern ◽  
Marked Decrease ◽  
Central Peak ◽  
Application Rate ◽  
Lateral Spread ◽  
Hill Country ◽  
Application Rates ◽  
Nominal Rate ◽  
Wide Swath

Five combinations of attachments were compared with an unmodified Fletcher aircraft for ability to spread fertiliser granules in a wide swath,over flat land at Napier, North Island. Lateral spread of fertiliser, applied at a nominal rate of approximately 500 kg/ha, was measured by the aircraft flying over a grid of collectors, making two passes for each configuration of attachments. An increase in lateral spread of fertiliser was obtained when theaircraft topdressed in each of the configurations with the tetrahedron spreader fitted but this was accompanied by a marked decrease in rate of application. For example, with the tetrahedron spreader lowered, with streamlining fairings fitted to the front and rear of the hopper outlet, and with accelerator ducts attached to the front f&ring, the swath width increased by 32%. up to 33 m, and the central peak from the distribution pattern, typical of that produced by an unmodified aircraft, was reduced. However the measured application rate fell to approximately 190 kg/ha with this combination of attachments compared with the 427 kg/ha for the unmodified aircraft. Further tests with an unmodrfied aircraft at lower application rates are needed before a direct comparison of swath width can be made. Keywords: Tetrahedron fertiliser spreader, topdressing, lateral spread, fertiliser distribution, hill country

scholarly journals Effects of repeated phosphorus fertilisation on field crops in Finland 2.Sufficient phosphorus application rates on silty and sandy soils

2008 ◽  
Vol 15 (4) ◽  
pp. 423 ◽  
Author(s):  
I. SAARELA ◽  
H. HUHTA ◽  
P. VIRKAJÄRVI
Keyword(s):  
Relative Yield ◽  
Sandy Soils ◽  
Application Rate ◽  
Application Rates ◽  
P Application ◽  
The Mean ◽  
Yield Responses ◽  
Phosphorus Application ◽  
Phosphorus Fertilisation ◽  
Annual Application

In order to update fertilisation recommendations for Finnish silty and sandy soils, the effects of repeated phosphorus (P) fertilisation on the yields of cereals, grasses and other crops were measured at ten sites for 9 to 18 years. Results of some earlier studies were also used in examining the relationships of the yield responses to applied P and to the soil test values measured by the Finnish ammonium acetate method (PAc). Significant effects of P fertilisation were observed at all sites that had low or medium PAc values; in the case of potatoes, even at sites with fairly high values. The mean relative yield without applied P divided by yield with 60 or 45 kg P ha-1 of the ten sites was 81% (mean PAc 11.6 mg dm-3) varying from 55% at the PAc value of 4.7 mg dm-3 to 100% at the highest PAc values. In order to achieve a relative yield of 97%, which is considered the optimum for cereals and leys, the required mean annual application of P in the later parts of the experiments was 25 kg ha-1 (variation 0-42 kg ha-1). On the six soils that had low or medium PAc values (4.5-9.1 mg dm-3, mean 8.0 mg dm-3), relative yield was 97% at the P application rate of 35 kg ha-1 (variation 22-42 kg ha-1), while 11 kg P ha-1 (variation 0-25 kg ha-1) sufficed on the four soils that had higher PAc values (mean 20.8 mg dm-3, variation 11.7-35.2 mg dm-3). Reasons for the poor availability of P in silty and sandy soils were discussed.;

scholarly journals CUTTING TECHNIQUES FOR PASTURE YIELDS ON HILL COUNTRY

1971 ◽  
pp. 91-104
Author(s):  
J.E. Radcliffe
Keyword(s):  
Sample Size ◽  
Standard Error ◽  
Large Sample ◽  
Hill Country ◽  
The Mean ◽  
The Difference ◽  
North And South

Production of pastures measured by the trim and difference cutting techniques are presented for sites on North Island hill pastures and South Island improved tussock grasslands. On North Island sites the trim technique consistently gave higher yields. On South Island sites, interim results have shown no consistent overall effect, although large differences in yields have been measured at some cuts. The number of samples required by the trim lechnique to give a standard error + 10% of mean yield was 30 on North Island sites (sample size 0.3 m x 0.2 m) and 15 on South Island sites (sample size 0.5 m x 0.5 m). The difference technique was much more variable and required 5 and 20 times more samples on North and South Island sites, respectively, to give a standard error +- 10% of the mean yield. On another North Island site, large, laxly trimmed sampling sites gave higher yields than smaller, severely trimmed sampling sites and one large sample (3.4 m x 1 .O m) generally gave similar precision in yields to 6 or 7 smaller samples (0.8 m x 0.3 m).

scholarly journals PONTAS TIPO CONE COM VARIAÇÃO DA TAXA DE APLICAÇÃO E VELOCIDADE NA CULTURA DO ALGODOEIRO

Nativa ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 301
Author(s):  
Thiago Martins Machado ◽  
Monyse Fin Barbosa ◽  
Adelina Vitória Servelhere de Rezende ◽  
Ronan Sauer Bueno
Keyword(s):  
Fiber Quality ◽  
Volume Density ◽  
Application Rate ◽  
Quality Parameters ◽  
Application Technology ◽  
Application Rates ◽  
Cone Type ◽  
Different Types ◽  
Application Volume ◽  
Droplet Density

A Ramulária é uma das principais doenças fungicas do algodoeiro, trazendo consequências graves para sua produtividade e qualidade de fibras. Com o intuito de abater os gastos e melhorar os parâmetros da aplicação, o trabalho tem por objetivo avaliar diferentes tipos de pontas de jato cônico e pingente, variando a taxa de aplicação e velocidade na pulverização do algodoeiro. Foram utilizadas pontas de jato cone vazio e cheio de diferentes fabricantes e também pingente associado a ponta cone vazio. As velocidades de deslocamento do pulverizador avaliadas foram 20 e 27 km h-1. As taxas de aplicações foram de 50 e 80 L ha-1. Os parâmetros avaliados foram: DMV, amplitude relativa (dispersão), volume, densidade e cobertura. O DMV foi satisfatório para todos os tratamentos. A ponta P2 obteve resultados inferiores nos parâmetros densidade de gotas, DMV e dispersão. Na velocidade de 27 km h-1 os parâmetros volume de aplicação, densidade e cobertura obtiveram melhores resultados em comparação com a velocidade de 20 km h-1. A taxa de aplicação mais elevada melhorou os parâmetros de qualidade de aplicação na densidade de gotas, cobertura e volume. O acessório pingente não obteve resultado significativo para densidade, dispersão, volume e cobertura na cultura do algodoeiro.Palavras-chave: algodão, qualidade de gotas, tecnologia de aplicação. CONE TYPE NOZZLES WITH VARIATION OF SPRAY RATE AND SPEED IN COTTON CULTURE ABSTRACT:Ramularia is one of the main fungal diseases of cotton, with serious consequences for its productivity and fiber quality. In order to reduce costs and improve the parameters of the application, the objective of this work is to test different types of conical and pendant jet tips, varying the rate of application and speed of cotton spraying. We used empty cone tips filled with different manufacturers and also pendant associated with empty cone tip The velocities evaluated were 20 and 27 km h-1. The application rates were 50 and 80 L ha-1. The parameters evaluated were: DMV, relative amplitude (dispersion), volume, density and coverage. DMV was satisfactory for all treatments. The full cone jet tip obtained lower results in the parameters of droplet density, DMV and dispersion. At the top speed the parameters application volume, density and coverage obtained better results compared to the lowest speed. The higher application rate improved the application quality parameters in droplet density, coverage and volume. The pendant accessory did not obtain significant results for density, dispersion, volume and coverage in the cotton crop.Keywords: cotton, drops quality, application technology.

The Effect of Vocabulary Intervention on Text Comprehension: Who Benefits?

2019 ◽  
Vol 50 (4) ◽  
pp. 562-578 ◽  
Author(s):  
Dawna Duff
Keyword(s):  
Middle School ◽  
Reading Comprehension ◽  
Text Comprehension ◽  
Classroom Instruction ◽  
Vocabulary Instruction ◽  
Clinical Intervention ◽  
Vocabulary Knowledge ◽  
Vocabulary Intervention ◽  
The Mean ◽  
The Difference

Purpose Vocabulary intervention can improve comprehension of texts containing taught words, but it is unclear if all middle school readers get this benefit. This study tests 2 hypotheses about variables that predict response to vocabulary treatment on text comprehension: gains in vocabulary knowledge due to treatment and pretreatment reading comprehension scores. Method Students in Grade 6 ( N = 23) completed a 5-session intervention based on robust vocabulary instruction (RVI). Knowledge of the semantics of taught words was measured pre- and posttreatment. Participants then read 2 matched texts, 1 containing taught words (treated) and 1 not (untreated). Treated texts and taught word lists were counterbalanced across participants. The difference between text comprehension scores in treated and untreated conditions was taken as a measure of the effect of RVI on text comprehension. Results RVI resulted in significant gains in knowledge of taught words ( d RM = 2.26) and text comprehension ( d RM = 0.31). The extent of gains in vocabulary knowledge after vocabulary treatment did not predict the effect of RVI on comprehension of texts. However, untreated reading comprehension scores moderated the effect of the vocabulary treatment on text comprehension: Lower reading comprehension was associated with greater gains in text comprehension. Readers with comprehension scores below the mean experienced large gains in comprehension, but those with average/above average reading comprehension scores did not. Conclusion Vocabulary instruction had a larger effect on text comprehension for readers in Grade 6 who had lower untreated reading comprehension scores. In contrast, the amount that children learned about taught vocabulary did not predict the effect of vocabulary instruction on text comprehension. This has implications for the identification of 6th-grade students who would benefit from classroom instruction or clinical intervention targeting vocabulary knowledge.

Efficacy and Safety of Oral Ivermectin and Topical Permethrin in the Treatment of Scabies

2020 ◽  
Vol 33 (1) ◽  
pp. 41-47
Author(s):  
Mohsena Akhter ◽  
Ishrat Bhuiyan ◽  
Zulfiqer Hossain Khan ◽  
Mahfuza Akhter ◽  
Gulam Kazem Ali Ahmad ◽  
...  
Keyword(s):  
Skin Diseases ◽  
Close Contact ◽  
Randomized Study ◽  
Sarcoptes Scabiei ◽  
Efficacy And Safety ◽  
Common Skin ◽  
Group A ◽  
The Mean ◽  
The Difference ◽  
Group B

Background: Scabies is one of the most common skin diseases in our country. It is caused by the mite Sarcoptes scabiei var hominis, which is an ecto-parasite infesting the epidermis. Scabies is highly contagious. Prevalence is high in congested or densely populated areas. Individuals with close contact with an affected person should be treated with scabicidal which is available in both oral and topical formulations. The only oral but highly effective scabicidal known to date is Ivermectin. Amongst topical preparations, Permethrin 5 % cream is the treatment of choice. Objective: To evaluate the efficacy & safety of oral Ivermectin compared to topical Permethrin in the treatment of scabies. Methodology: This prospective, non-randomized study was conducted at the out-patient department of Dermatology and Venereology of Shaheed Suhrawardy Medical College & Hospital over a period of 6 months, from August 2016 to January 2017. The study population consisted of one hundred patients having scabies, enrolled according to inclusion criteria. They were divided into two groups. group A was subjected to oral Ivermectin and the group B to Permethrin 5% cream. Patients were followed up on day 7 and 14 for assessment of efficacy and safety. Result: The mean scoring with SD in group A (Ivermectin) and group B (Permethrin) were 8.26 ± 2.22 and 7.59 ± 2.01 respectively at the time of observation. The difference between the mean score of the two group is not significant (p=0.117) the mean scoring with SD in group A and group B were 4.54 ± 2.05 and 1.64 ± 1.84 respectively at 7thdays. The difference between the mean score of the two group is significant (p<0.001). The mean scoring with SD in group A and group B were 2.68± 2.35 and .36± 1.10 respectively at 14th day difference between the mean score of the group is significant (p<0.001). Conclusion: Topical application of permethrin 5% cream is more effective and safer than oral Ivermectin in the treatment of scabies. TAJ 2020; 33(1): 41-47

EFFECTS OF SYNTHETIC LH/FSH-RELEASING HORMONE (LRH) ON PLASMA LH AND FSH IN AMENORRHOEIC WOMEN

1974 ◽  
Vol 75 (4) ◽  
pp. 647-652 ◽  
Author(s):  
G. Rannevik ◽  
J. Thorell
Keyword(s):  
Urinary Excretion ◽  
Initial Response ◽  
Releasing Hormone ◽  
The Mean ◽  
The Difference ◽  
Serial Measurements

ABSTRACT Eight amenorrhoeic women were given 100 μg synthetic LRH (Hoechst) iv and im, respectively, at an interval of 2 weeks. Four of the women received the iv injection first and four the im injection. The urinary excretion of oestrogens and pregnanediol was low and unaltered throughout the test weeks. The effects of LRH were compared by serial measurements of the plasma LH and FSH during 8 h. The initial response of LH for up to 25 min and that of FSH for up to 60 min were equal whether LRH was given iv or im. The difference appeared later. Four hours after the injection the mean increase of LH to iv injection was 0.5 ng/ml (N. S.), while that to im injection was 1.9 ng/ml (P < 0.01). The corresponding values for FSH were 1.3 (P < 0.05) and 3.2 (P < 0.001). The effect of LRH administration im was thus found to be larger and more prolonged.

Development of Prolonged Delivery of Tramadol and Dissolution Translation by Statistical Data Treatment

2011 ◽  
Vol 4 (1) ◽  
pp. 1331-1337
Author(s):  
P B Parejiya ◽  
B S Barot ◽  
P K Shelat
Keyword(s):  
Drug Release ◽  
Study Data ◽  
Stability Study ◽  
Dissolution Time ◽  
Matrix Tablet ◽  
Burst Effect ◽  
The Matrix ◽  
The Mean ◽  
The Difference ◽  
Dissolution Efficiency

The present study was carried out to fabricate a prolonged design for tramadol using Kollidon SR (Polyvinyl acetate and povidone based matrix retarding polymer). Matrix tablet formulations were prepared by direct compression of Kollidon SR of a varying proportion with a fixed percentage of tramadol. Tablets containing a 1:0.5 (Drug: Kollidon SR) ratio exhibited a rapid rate of drug release with an initial burst effect. Incorporation of more Kollidon SR in the matrix tablet extended the release of drug with subsequent minimization of the burst effect as confirmed by the mean dissolution time, dissolution efficiency and f2 value. Among the formulation batches, a direct relationship was obtained between release rate and the percentage of Kollidon SR used. The formulation showed close resemblance to the commercial product Contramal and compliance with USP specification. The results were explored and explained by the difference of micromeritic characteristics of the polymers and blend of drug with excipients. Insignificant effects of various factors, e.g. pH of dissolution media, ionic strength, speed of paddle were found on the drug release from Kollidon-SR matrix. The formulation followed the Higuchi kinetic model of drug release. Stability study data indicated stable character of Batch T6 after short-term stability study.

Seasonal trends in the stable isotopic composition of snow and meltwater runoff in a subarctic catchment at Okstindan, Norway

2004 ◽  
Vol 35 (2) ◽  
pp. 119-137 ◽  
Author(s):  
S.D. Gurney ◽  
D.S.L. Lawrence
Keyword(s):  
Isotopic Composition ◽  
Mean Value ◽  
Mean Values ◽  
Stable Isotopic Composition ◽  
Meltwater Runoff ◽  
Stable Isotopic ◽  
The Mean ◽  
The Difference ◽  
Δ18o And Δd

Seasonal variations in the stable isotopic composition of snow and meltwater were investigated in a sub-arctic, mountainous, but non-glacial, catchment at Okstindan in northern Norway based on analyses of δ18O and δD. Samples were collected during four field periods (August 1998; April 1999; June 1999 and August 1999) at three sites lying on an altitudinal transect (740–970 m a.s.l.). Snowpack data display an increase in the mean values of δ18O (increasing from a mean value of −13.51 to −11.49‰ between April and August), as well as a decrease in variability through the melt period. Comparison with a regional meteoric water line indicates that the slope of the δ18O–δD line for the snowpacks decreases over the same period, dropping from 7.49 to approximately 6.2.This change points to the role of evaporation in snowpack ablation and is confirmed by the vertical profile of deuterium excess. Snowpack seepage data, although limited, also suggest reduced values of δD, as might be associated with local evaporation during meltwater generation. In general, meltwaters were depleted in δ18O relative to the source snowpack at the peak of the melt (June), but later in the year (August) the difference between the two was not statistically significant. The diurnal pattern of isotopic composition indicates that the most depleted meltwaters coincide with the peak in temperature and, hence, meltwater production.

Study of pumping effect in flow-through electrolysers

1983 ◽  
Vol 48 (8) ◽  
pp. 2232-2248 ◽  
Author(s):  
Ivo Roušar ◽  
Michal Provazník ◽  
Pavel Stuhl
Keyword(s):  
Natural Convection ◽  
Balance Equation ◽  
Volume Fraction ◽  
Industrial Applications ◽  
Pumping Effect ◽  
Flow Through ◽  
The Mean ◽  
The Difference

In electrolysers with recirculation, where a gas is evolved, the pumping of electrolyte from a lower to a higher level can be effected by natural convection due to the difference between the densities of the inlet electrolyte and the gaseous emulsion at the outlet. An accurate balance equation for calculation of the rate of flow of the pumped liquid is derived. An equation for the calculation of the mean volume fraction of bubbles in the space between the electrodes is proposed and verified experimentally on a pilot electrolyser. Two examples of industrial applications are presented.

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