Nitrogen (N) fertilizer rate is important for high yield and good quality of potato tubers. In this dissertation, I seek to study the response of different potato cultivars under different N fertilizer rates and how that can impact tuber quality, examine the performance of active optical sensors in improving a potato yield prediction algorithm, and evaluate the ability of active optical sensors (GreenSeeker (GS) and Crop Circle (CC)) to optimize a N recommendation algorithm that can be used by potato growers in Maine. This research was conducted at 11 sites over a period of two years (2018–2019) in Aroostook County, Maine; all sites depended on a rainfed system. Three potato cultivars, Russet Burbank, Superior, and Shepody, were planted under six rates of N (0-280 kg ha-1), ammonium sulfate and ammonium nitrate, and were applied in a randomized complete block design (RCBD) with four replications. Active optical sensor readings (normalized difference vegetation index (NDVI)) were collected weekly after the fourth leaf stage began. The coefficient of determination (R2) between soil organic matter (OM) content and total tuber yield for all sites combined was 0.78**. Sites with ≥ 30 g kg-1 of soil OM produced higher total tuber yield, marketable yield, and tuber weight per plant (39.45%, 45.22%, and 54.94%, respectively) than sites with ≤ 30 g kg-1 of OM. Specific gravity increased by 0.18% in the sites with ≥ 30 g kg-1 of OM. The total tuber yield for the three cultivars was maximized at 168 kg N ha-1. Vegetation indices measurements obtained at stages of 16 or 20 fully expanded leaves were significantly correlated with tuber yield, which can be used in the yield prediction model. Sensor measurements obtained at the 20th leaf stage were significantly correlated with tuber yield, with the exponential model showing the best fit for the regression curve. The recommended N rate calculated based on in-season sensor readings was reduced by approximately 12–14% compared to the total N rate that growers currently apply based on the conventional approach.
There are two main categories of force control schemes: hybrid position-force control and impedance control. However, the former does not take into account the dynamic interaction between the robot’s end effector and the environment. In contrast, impedance control includes regulation and stabilization of robot motion by creating a mathematical relationship between the interaction forces and the reference trajectories. It involves an energetic pair of a flow and an effort, instead of controlling a single position or a force. A mass-spring-damper impedance filter is generally used for safe interaction purposes. Tuning the parameters of the impedance filter is important and, if an unsuitable strategy is used, this can lead to unstabl
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Background: Emergency contraception (EC) is a general term used to describe drugs and devices that are utilized to prevent pregnancy following unprotected intercourse or in the event of contraceptive failure. This postcoital birth-control option is available by means of hormonal pills or copper-bearing intrauterine device.Objectives: The objectives of the study were to assess the women's knowledge regarding EC, to compare the knowledge of school teachers with other women in the community, as well as assessing the pre-post test knowledge of teachers.Type of the study: A cross sectional and quasi- experimental study.Methods: It was carried out in Duhok during the period from 20th of November 2014 to 6th of January 2015. A Simple and system
... Show MoreLearn new methods of teaching mathematics contribute to raising the level of pupils to acquire mathematical concepts primary stage
Attempt advancement in the level of mathematics teaching for the better through the use of modern teaching strategies. The research aims at the progress in the acquisition of mathematical concepts schoolgirls after subjecting the fourth grade to teach in active learning strategies, the number of research sample (60) schoolgirl, by (30) schoolgirl experimental group and 30 pupils of the control group. Clear from the results shown the presence of a statistically significant difference between the acquisition of concepts of schoolgirls two groups (experimental and control) for the benefit of pupils of the exp
The aim of the work is synthesis and characterization of bidentate ligand [dipotassium sodium7-((E)-2-(2-((Z)-1-carboxylatoethylideneamino)thiazol-4-yl)-2 (carboxylatemethoxyimino) acet amido)-8-oxo-3-vinyl-5- thia-1-azabicyclo[4.2.0] oct-2- ene-2- carboxylate] [Nak2L], from the reaction of cefixime with sodium pyruvet to produce the ligand [Nak2L], the reaction was carried out in methanol as a solvent under reflux. The prepared ligand [Nak2L] which was characterized by FT-IR, UV-Vis spectroscopy, 1H, 13C-NMR spectra, Mass spectra, (C.H.N) and melting point. The mixed ligand complexes were prepared from ligand [Nak2L] was used as a primary ligand while 8-hydroxy quinoline [Q] was used as a secondary ligand with metal ion M(?).Where M(?) =
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The aim of the work is synthesis and characterization of bidentate ligand [dipotassium sodium7-((E)-2-(2-((Z)-1-carboxylatoethylideneamino)thiazol-4-yl)-2 (carboxylatemethoxyimino) acet amido)-8-oxo-3-vinyl-5- thia-1-azabicyclo[4.2.0] oct-2- ene-2- carboxylate] [Nak2L], from the reaction of cefixime with sodium pyruvet to produce the ligand [Nak2L], the reaction was carried out in methanol as a solvent under reflux. The prepared ligand [Nak2L] which was characterized by FT-IR, UV-Vis spectroscopy, 1H, 13C-NMR spectra, Mass spectra, (C.H.N) and melting point. The mixed ligand complexes were prepared from ligand [Nak2L] was used as a primary ligand while 8-hydroxy quinoline [Q] was used as a secondary ligand with metal ion M(Π).Where
... Show MoreTwo Prototypes of Transversely Excited at atmospheric pressure (TEA) Nitrogen laser systems (One Stage Blumlein Circuit and Two Stage Blumlein Circuit) were fabricated and operated. High voltage power supply with variable operating voltage (0-20 kv) and operating current (1-3A) was built and tested successfully. The gas flow rate of 15 L/ min and 10 L/ min for OSBC and TSBC was used. The performance of the fabricated systems was studied extensively reaching to the optimum operating conditions. The obtained laser output energy for the first system has linear relationship with the applied voltage. The maximum output energy was about (1.14 mJ) with (10.40) ns pulse duration and the half-wave divergence angle was about (0.1455 m rad). In the
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Metoclopramide (MCP) ion selective electrodes based on metoclopramide-phosphotungstic acid (MCP-PT) ion pair complex in PVC matrix membrane were constructed. The plasticizers used were tri-butyl phosphate (TBP), di-octyl phenyl phosphonate (DOPP), di-butyl phthalate (DBPH), di-octyl phthalate (DOP), di-butyl phosphate (DBP), bis 2-ethyl hexyl phosphate (BEHP). The sensors based on TBP, DOPP, DBPH and DOP display a fast, stable and linear response with slopes 59.9, 57.7, 57.4, 55.3 mV/decade respectively at pH ranged 2-6. The linear concentration range between 1.0×10-5 – 1.0×10-2 M with detection limit 3.0×10-6 and 4.0×10-6 M for electrodes using TBP, DOPP and DBPH while e
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