First report of the parasitoid wasp, Diadegma pusio (Hym.: Ichneumonidae), from Iran

This is a report on the occurrence of the hymenoterous parasitoid of the beet moth, Scrobipalpa ocellatella Boyd (Lep.: Gelechiidae), in Iran for the first time. Diadegma pusio (Holmgren) was collected from the larvae of S. ocellatella in the sugar beet fields located in Ray, the southern district of Tehran. This ichneumonid species is belonging to the subfamily Campopleginae and tribe Limneriini

Effect of temperature and photoperiod on reproductive behavior of corn stem borer, Sesamia cretica (Lederer, 1857) (Lep.: Noctuidae)

The corn stem borer, Sesamia cretica Led. (Lep.: Noctuidae),is the most important pest of maize and sugarcane throughout the world including Iran where its egg parasitoid wasp, Telenomus busseolae Gahan (Hym.: Scelionidae) is widely used in biological control programs. Due to the host specificity of the parasitoid wasp, S. cretica serves as the single host for the mass rearing of T. busseolae at the laboratory or insectarium. The present work was intended to find the optimum temperature and photoperiod for the reproductivity of S. cretica at laboratory condition. We evaluated the percentage of fertilized eggs, oviposition rate, peak of egg laying and adult longevity of S. cretica. Thermal treatments and photoperiod treatments included 24, 27 and 30 ºC as well as 24D, 12D: 12L, 8L: 16D (short day period), 16L:8D (long day period) hours respectively. The best temperature for oviposition was calculated between 24 and 27 ºC, but the rate of oviposition was significantly decreased at 30 ºC. Temperature and photoperiod had no effect on the percentage of fertilized eggs and adult longevity. Different photoperiods caused significant effect on the rate of oviposition and the highest oviposition rate occurred in 12L: 12D hours and in 16D:8L hours. The lowest rate of oviposition was observed in 24D period. The highest rate of oviposition occurred on the second day

First report of the parasitoid wasps, Microchelonus subcontractus and Bracon intercessor (Hym.: Braconidae), from Iran

This paper reports the occurrence of the hymenoterous parasitoids of the beet moth, Scrobipalpa ocellatella Boyd larvae in Iran for the first time. Two braconid species of Microchelonus subcontractus Abdinbekova and Bracon intercessor Nees were collected from the larvae of S. ocellatella in the sugar beet fields located in Ray, the southern district of Tehran. These parasitoids are belonging to the subfamilies Cheloninae and Braconinae, respectively

Platelet-rich plasma for regeneration of neural feedback pathways around dental implants: a concise review and outlook on future possibilities

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Power injection model of IDC-PFC for NR-based and technical constrained MT-HVDC grids power flow studies

© 2020 Elsevier B.V. Insufficient control flexibility in multi-terminal HVDC (MT-HVDC) grids is an important motivation to install suitable power electronic-based DC power flow controller (PFC)s to ensure grid controllability, security, and reliability. This article proposes a new static power injection model (PIM) for those (interline) DC-PFCs to enable DC power flow (PF) studies and ease integration of the PFCs in the power system analysis softwares within the well-accepted Newton–Raphson (NR) solver-based framework. HVDC lines shunt conductances are also taken in to account in this newly developed paradigm. For this purpose, the IDC-PFC, as well as other MT-HVDC grid physical/control state variables are modified in cooperation to attain predefined control objective(s). Furthermore, a novel general routine (solution procedure) is proposed to handle several system physical/control limitations during the NR-based DC PF problem solution. Static/dynamic simulations are executed on an eight-bus test MT-HVDC grid to show/confirm the accuracy, effective performance, and excellent convergence property of the proposed IDC-PFC model, NR-based DC PF solver, and technical constraints handling routine. In this situation, it is proved that the original structure and symmetry of the admittance matrix can still be kept, and a few modifications are needed to be done in the Jacobin matrix

Change in life expectancy and stable age distribution of the diamondback moth, Plutella xylostella (L.) after indoxacarb treatment

Using high doses of insecticides is very dangerous for the environments and for humans. Decreased concentrations are necessary. Insecticides have lethal and sublethal effects. The aim of the present study was to determine the behavior of Plutella xylostella when exposed to sublethal doses of indoxacarb in terms of the age-specific fecundity (mx), life expectancy (ex) and stable age distribution (Cx). Also, the effects of sublethals on the pre-oviposition, oviposition and post-oviposition period of this insect were investigated. The results show that exposure to this insecticide decreased the age-specific fecundity (mx) and life expectancy (ex) of the insect. Although the pre-oviposition period was delayed in the treated groups, the post-oviposition period significantly decreased when exposed to LC10 and LC25 doses (the dose concentrations killed 10 and 25% of the populations) of indoxacarb. The oviposition period did not change. Furthermore, sublethal concentrations of the applied insecticide caused changes in the exposed structure

Technical Constrained Power Flow Studies for IDC-PFC Integrated into the MT-HVDC Grids

Power flow (PF) flexibility in the multi-terminal HVDC (MT-HVDC) grids is a thought-provoking issue. It leads to employing the active DC power flow controller (DC-PFC)s. Hence, this paper examines the static average model (AM) and power injection model (PIM) of an interline DC-PFC (IDC-PFC). It is to provide a suitable base for DC PF studies and easy embedding of the DC-PFCs into MT-HVDC grids' PF equations. In this regard, this paper proposes a new DC PF solver (DC-PFS) for the IDC-PFC compensated MT-HVDC grids within the well-accepted Newton-Raphson (NR) framework. It requires a few modifications in the main structure of the system's Jacobin (J) matrix compared to the uncompensated MT-HVDC grid. Also, the system's admittance matrix and its symmetry are preserved. In the proposed concept, the IDC-PFC cooperates with other MT-HVDC grid's state variables to satisfy the predetermined control objective(s). Furthermore, this paper proposes a new solution procedure (SP) to handle various system's limitations during the processes of solving the DC PF problem. Meanwhile, there is no need to modify the related J matrix. The effective and accurate performance of the IDC-PFC's models, as well as presented NR-based DC-PFS and SP, are verified by performing several simulations on the 8-bus CIGRE MT-HVDC grid

Static Modeling of the IDC-PFC to Solve DC Power Flow Equations of MT-HVDC Grids Employing the Newton-Raphson Method

© 2019 IEEE. Power transmission technology of the offshore wind farm (OWF)s is usually based on HVDC interconnection. Power flow controller (PFC)s are flexible power transmission devices which play important role in the DC power flow (PF) control especially in contingency conditions. So, these devices should be modeled to solve related MT-HVDC grid DC PF equations. In this context, an interline DC PFC (IDC-PFC) is considered as a sample PFC for modeling due to its advantages in comparison to other series and cascaded PFCs. The novelty of this work is solving the DC PF problem of the IDC-PFC compensated MT-HVDC grids by modeling of the IDC-PFC and employing the Newton-Raphson (N-R) method. An eight-bus MT-HVDC test grid is considered to authenticate the presented IDC-PFC modeling and verify the accuracy of the DC PF results obtained by employing the N-R method. The obtained static results verify the accuracy of the presented IDC-PFC modeling and the performance of the N-R method in solving flexible MT-HVDC grid PF equations. Hence, it is suitable to integrate them in the future power system analysis softwares