The systematic study of the influence of neutron excess on the fusion cross sections using different proximity-type potentials

Using different types of proximity potentials, we have examined the trend of variations of barrier characteristics (barrier height and its position) as well as fusion cross sections for 50 isotopic systems including various collisions of C, O, Mg, Si, S, Ca, Ar, Ti and Ni nuclei with $1\leq N/Z < 1.6$ condition for compound systems. The results of our studies reveal that the relationships between increase of barrier positions and decrease of barrier heights are both linear with increase of $N/Z$ ratio. Moreover, fusion cross sections also enhance linearly with increase of this ratio.Comment: 28 pages, 7 figures, 5 Table

Green Synthesis of Silver Nanoparticles Induced by the Fungus Penicillium citrinum

Purpose: To evaluate a green process for the extracellular production of silver (Ag) nanoparticles synthesized and stabilized using Penicillium citrinum isolated from soil.Methods: The pure colonies of Penicillium citrinum were cultured in Czapek dox broth. The supernatant of the broth was examined for the ability to produce silver nanoparticles. The reactions were performed in a dark compartment at 28 oC. After 24 h, the synthesized silver nanoparticles were filtered through a membrane filter (0.45 ƒÊ) and characterized by UV-visible spectroscopy, fluorescence spectroscopy, photon correlation spectroscopy (PCS), scanning electron microscopy (SEM) and Fourier transformed infrared spectroscopy (FTIR) for particle size, shape and the presence of different functional groups in the nanoparticles.Results: The silver nanoparticles formed were fairly uniform in size with a spherical shape and a Zaverage diameter of 109 nm. FTIR spectra revealed the presence of amide linkage groups which were also found in the fungal extract itself.Conclusion: The current approach suggests that rapid synthesis of nanoparticles of silver nitrate would be suitable for developing a biological process for mass scale production of formulations.Keywords: Green synthesis, Penicillium citrinum, silver nanoparticles

First record of the parasitoid wasp Macrocentrus oriens (Hym.: Braconidae, Macrocentrinae) from Iran

A survey was conducted to study the parasitoid wasps associated with the pistachio gall aphids, Forda hirsuta and Slavum mordvilcovi on Pistacia atlantica,in the southern Iranian Fars province during 2013. The overwintering galls were randomly collected and reared inside plastic jars at room temperature until the emergence of adults wasps . We identified the species Macrocentrus oriens (van Achterberg & Belokobylskij 1987) (Hym.: Braconidae, Macrocentrinae) and report it here from Iran for the first time

First report of the parasitoid wasp Aneuclis melanaria (Hym.: Ichneumonidae: Tersilochinae) from Iran

In 2013, we launched a project to collect and identify the insects, which were associated with the pistachio gall aphid species Forda hirsuta Mordv. and Slavum mordvilovi Kreutz in Tang-Shekan region of the city of Arsanjan in the province of Fars. We collected the ichneumonid wasp Aneuclis melanaria (Holmgren) of the subfamily Tersilochinae on the aphid populations of S. mordvilovi. This parasitoid wasp is a new record for the fauna of Iran

An energy-efficient mobile sink-based unequal clustering mechanism for WSNs

Network lifetime and energy efficiency are crucial performance metrics used to evaluate wireless sensor networks (WSNs). Decreasing and balancing the energy consumption of nodes can be employed to increase network lifetime. In cluster-based WSNs, one objective of applying clustering is to decrease the energy consumption of the network. In fact, the clustering technique will be considered effective if the energy consumed by sensor nodes decreases after applying clustering, however, this aim will not be achieved if the cluster size is not properly chosen. Therefore, in this paper, the energy consumption of nodes, before clustering, is considered to determine the optimal cluster size. A two-stage Genetic Algorithm (GA) is employed to determine the optimal interval of cluster size and derive the exact value from the interval. Furthermore, the energy hole is an inherent problem which leads to a remarkable decrease in the network’s lifespan. This problem stems from the asynchronous energy depletion of nodes located in different layers of the network. For this reason, we propose Circular Motion of Mobile-Sink with Varied Velocity Algorithm (CM2SV2) to balance the energy consumption ratio of cluster heads (CH). According to the results, these strategies could largely increase the network’s lifetime by decreasing the energy consumption of sensors and balancing the energy consumption among CHs

What can whiskers tell us about mammalian evolution, behaviour, and ecology?

Most mammals have whiskers; however, nearly everything we know about whiskers derives from just a handful of species, including laboratory rats Rattus norvegicus and mice Mus musculus, as well as some species of pinniped and marsupial. We explore the extent to which the knowledge of the whisker system from a handful of species applies to mammals generally. This will help us understand whisker evolution and function, in order to gain more insights into mammalian behaviour and ecology. This review is structured around Tinbergen’s four questions, since this method is an established, comprehensive, and logical approach to studying behaviour. We ask: how do whiskers work, develop, and evolve? And what are they for? While whiskers are all slender, curved, tapered, keratinised hairs that transmit vibrotactile information, we show that there are marked differences between species with respect to whisker arrangement, numbers, length, musculature, development, and growth cycles. The conservation of form and a common muscle architecture in mammals suggests that early mammals had whiskers. Whiskers may have been functional even in therapsids. However, certain extant mammalian species are equipped with especially long and sensitive whiskers, in particular nocturnal, arboreal species, and aquatic species, which live in complex environments and hunt moving prey. Knowledge of whiskers and whisker use can guide us in developing conservation protocols and designing enriched enclosures for captive mammals. We suggest that further comparative studies, embracing a wider variety of mammalian species, are required before one can make large-scale predictions relating to evolution and function of whiskers. More research is needed to develop robust techniques to enhance the welfare and conservation of mammals