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Number of results: 4
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Abstract

The excessive use of chemical products to control thrips and the tomato spotted wilt virus (TSWV) is not only harmful to human health, the environment, and biodiversity, but also the resistance these generate in insects turns them inefficient in the long run. Consequently, to achieve sustainable and residue-free production, control alternatives must be explored. This work proposes the use of Beauveria bassiana (BB) in combination with inter-row cover (IC) to reduce the population of thrips and the incidence of TSWV on bell pepper. For this purpose, a trial was carried out in a bell pepper greenhouse, consisting of four randomly distributed treatments with four repetitions of 66 plants each. The treatments assayed were: T (without BB inoculation or IC), TC (without BB inoculation and with IC), B (inoculated with BB), and BC (inoculated with BB and IC). The B. bassiana CEP147 strain was used based on its effectiveness in previous laboratory tests. After detecting one thrips per flower, five foliar spray applications were made at weekly intervals. The trial lasted 4 months. During this time, the number of thrips in the three central plants of each repetition, the presence of symptoms compatible with TSWV, as well as the number of fruits, and their weight, length, width and health were monitored weekly. Between the fourth and sixth weeks after the last application, a significant reduction in the population of total thrips (nymphs + + adults) was observed in both treatments B and BC compared to T and TC. In addition, plants with symptoms compatible with TSWV were very scarce, and the fruits showed significant differences in their quality parameters, producing the longest and heaviest in the BC treatment. The results showed that combining biological and cultural control makes sustainable pepper production possible.
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Authors and Affiliations

María Emilia dos Santos Domingues
1
ORCID: ORCID
Mariana Del Pino
2
ORCID: ORCID
Andrea Vanesa Toledo
3
ORCID: ORCID

  1. Curso de Prácticas Profesionales I, Universidad Nacional Arturo Jauretche, Buenos Aires, Argentina
  2. Curso de Horticultura y Floricultura, Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata, Buenos Aires, Argentina
  3. Centro de Investigaciones de Fitopatología (CIDEFI-CICBA), Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata, Buenos Aires, Argentina
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Abstract

In this research, Co-30 mass% Cr alloys were fabricated by a vacuum hot-press sintering process. Different amounts of submicron cobalt and chromium (the mean grain size is 800 and 700 nm, respectively) powders were mixed by ball milling. Furthermore, this study imposed various hot-press sintering temperatures (1100, 1150, 1200 and 1250°C) and pressures (20, 35 and 50 MPa), while maintaining the sintering time at 1 h, respectively. The experimental results show that the optimum parameters of hot-press sintered Co-30 mass% Cr alloys are 1150°C at 35 MPa for 1 h. Meanwhile, the sintered density reaches 7.92 g·cm–3, the closed porosity decreases to 0.46%, and the hardness and transverse rupture strength (TRS) values increase to 77.2 HRA and 997.1 MPa, respectively. While the hot-press sintered Co-30 mass% Cr alloys at 1150°C and 20 MPa for 1 h, the electrical conductivity was slightly enhanced to 1.79 × 104 S·cm–1, and the phase transformation (FCC → HCP) of cobalt displayed a slight effect on sintering behaviors of Co-30 mass% Cr alloys. All these results confirm that the mechanical and electrical properties of Co-30 mass% Cr alloys are effectively improved by using the hot-press sintering technique.

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Authors and Affiliations

Shih-Hsien Chang
ORCID: ORCID
Chih-Yao Chang
Kuo-Tsung Huang
ORCID: ORCID
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Abstract

An enormous number of structures and roads are put on expansive subgrade soils and may be exposed to the swelling and shrinkage risk. To prevent the expanding weight of the subgrade layer under loaded pavement, one of the following strategies may be utilized are geogrid layer. Reinforced pavement layers have been propagated in the field of civil engineering because of their profoundly adaptable and diversified use. In this study, axisymmetric models of pavement layers have been created by 2-D Plaxis software and all of these models included geogrid layers at various positions concentrated to research the impact of geogrid on the critical pavement responses. Geogrid was placed at the bottom of asphalt layer, bottom of base layer, tope and middle of the subgrade layer. All models are loaded with incremental contact pressure between 50 and 600 kPa. Analysis processes have been made for all models and the obtained investigation results show a significant effect on pavement behavior when the a geogrid layer was used under various tire pressures. Also, there is an increase in the bearing capacity of a model that includes geogrid at the top and middle of the subgrade layer by about 35% and the resistance of the asphalt layer to deformation and cracking failure was improved.
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Authors and Affiliations

Ghadah Ghassan Masood
1
ORCID: ORCID
Hadeel Ammar Mohammed
1
ORCID: ORCID
Hanan Adnan Hassan Afaj
1
ORCID: ORCID
Mohammed Yousif Fattah
2
ORCID: ORCID

  1. Lecturer, Highway and Transportation Department, Engineering College, Mustansiriyah University, Iraq, Baghdad
  2. Civil Engineering Department, University of Technology, Iraq
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Abstract

The paper treats of correcting calculation errors of the BLDC motor speed, based on the time elapsed between successive changes in the shaft position sensor signal. The developed method enables correction of errors of the deployment of sensors as well as rotating elements of the observation system of the motor shaft position. The correction algorithm performance was analysed with the aid of a model implemented in Matlab-Simulink environment. After confirming usefulness of the developed method through simulation, its usefulness was verified in real closed-loop feedback systems with a BLDC motor. The results of measurements carried out at the developed laboratory station are presented.
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Authors and Affiliations

Krzysztof Kolano

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