Gamma-Ray Emission From Be/X-Ray Binaries

Be/X-ray binaries are systems formed by a massive Be star and a magnetized neutron star, usually in an eccentric orbit. The Be star has strong equatorial winds occasionally forming a circumstellar disk. When the neutron star intersects the disk the accretion rate dramatically increases and a transient accretion disk can be formed around the compact object. This disk can last longer than a single orbit in the case of major outbursts. If the disk rotates faster than the neutron star, the Cheng-Ruderman mechanism can produce a current of relativistic protons that would impact onto the disk surface, producing gamma-rays from neutral pion decays and initiating electromagnetic cascades inside the disk. In this paper we present calculations of the evolution of the disk parameters during both major and minor X-ray events, and we discuss the generation of gamma-ray emission at different energies within a variety of models that include both screened and unscreened disks.Comment: 14 pages, to appear in: "The multiwavelength approach to unidentified gamma-ray sources", Eds. K. S. Cheng & G.E. Romero, Kluwer Academic Publisher (Astrophysics and Space Sciences Journal). The present version has two additional figures respect to the version to be published in the journa

Phenolic Compound Profiles in Grape Skins of Cabernet Sauvignon, Merlot, Syrah and Marselan Cultivated in the Shacheng Area (China)

The phenolic compounds in the grape skins of Cabernet Sauvignon (CS), Merlot (ML), Syrah (SY) and Marselan (MS) from Shacheng, in China, were compared using HPLC-MS/MS. The results showed that the types and levels of phenolic compounds varied greatly with cultivars. Malvidin derivatives were the main anthocyanins. CS and ML showed a higher content of malvidin-3-O-(6-O-acetyl)-glucoside than malvidin-3-O-(trans-6-O- coumaryl)-glucoside, while SY and MS differed from CS and ML. ML had higher delphinidin and cyanidin derivatives, SY had higher peonidin derivatives, while malvidin and petunidin were higher in MS. The total content of flavonols, flavan-3-ols, phenolic acids and stilbenes in grape skins showed no difference among CS, ML and MS. Isorhamnetin-3-O-glucoside (CS, ML, MY), quercetin-3O-glucoside (SY), procyanidin trimer (SY, MS), procyanidin dimer (CS, ML), syringetin-3-O-glucoside, trans-cinnamic acid and resveratrol were the most abundant non-anthocyanin phenolic compounds. Cluster analysis showed that CS and ML, and SY and MS had similar phenolic profiles

A review on plant genomes of some important traditional chinese fruits and herbs

Chinese medicinal herbs and fruits have grown rapidly and significantly in recent years and have a positive influence on improving people’s attention to their health and organic life style. According to the advancement of sequencing technologies and reduced costs, the genome sequencing data of medicinal plants are accumulating rapidly. Our aim was to review plant genomes of three important medicinal plants in China. There is an ample genetic diversity of plants with medicinal importance around the globe and this pool of genetic variation serves as the base for selection, as well as for plant improvement. Plant genomes are characterized by large variations of genome size and ploidy level. Comparative genomics provides a method to unravel the relationship between genomes, by describing conserved chromosomes or chromosomal regions between related species. It is also clear that it is possible to use plant genome as a tool for improving breeding strategies. However, certain limitations represent a number of challenges for the generation and utilization of genomic resources in many important medicinal plant species. This review has focused on plant genomes of some important horticultural plants, which are famous in traditional Chinese medicine, namely ginger, ginseng and goji berry. However, more researches are needed to introduce the genome research of medicinal plants

Interfacial breakdown on contaminated electrolytic surfaces

The insulation of overhead transmission lines and substations is subjected to several basic types of abnormal conditions that can cause flashovers and outages of long duration. One of these types is abnormal voltage gradients in the insulation system caused by the contamination of solid insulator surfaces. The number of insulators needed to protect against contamination is uncertain, because there is a wide range in the severity of contamination, and there is considerable uncertainty as to the basic mechanisms by which contamination affects the insulation level of a given configuration. This paper outlines the results of investigations of interfacial breakdown on electrolytic surfaces. Models are used to simulate such plotted insulator problems. Effects of the chemical nature of the contaminants and contamination levels on the critical flashover voltage are studied. In order to study such effects, different salts and salts combinations were used on the laboratory model. A single-arc and multiple-arc models are introduced where the phenomena of multiple discharges existing simultaneously on an electrolytic surface is also investigated. Mathematical models are suggested which include the successive formation of multiple-arcs. The results obtained based on the new model agree quite well with the experimental value

Interfacial breakdown on contaminated electrolytic surfaces

The insulation of overhead transmission lines and substations is subjected to several basic types of abnormal conditions that can cause flashovers and outages of long duration. One of these types is abnormal voltage gradients in the insulation system caused by the contamination of solid insulator surfaces. The number of insulators needed to protect against contamination is uncertain, because there is a wide range in the severity of contamination, and there is considerable uncertainty as to the basic mechanisms by which contamination affects the insulation level of a given configuration. This paper outlines the results of investigations of interfacial breakdown on electrolytic surfaces. Models are used to simulate such plotted insulator problems. Effects of the chemical nature of the contaminants and contamination levels on the critical flashover voltage are studied. In order to study such effects, different salts and salts combinations were used on the laboratory model. A single-arc and multiple-arc models are introduced where the phenomena of multiple discharges existing simultaneously on an electrolytic surface is also investigated. Mathematical models are suggested which include the successive formation of multiple-arcs. The results obtained based on the new model agree quite well with the experimental value

The impact of soil amendment of super absorbent polymer on grain yield and yield components of corn in center of Iran

Corn is one of the most important cereal crop grown in Iran. A complete randomized design with four replications was used to analysis the influence of soil amendment of super absorbent polymer on grain yield and yield components of corn in center of Iran in 2016 and 2017. Treatments with super absorbent polymer were 0 kg/ha (S1), 15 kg/ha (S2), 30 kg/ha (S3), and treatments with fertilizers were 50% (F1), 75% (F2), 100% (F3), which could be combined into nine pots. The influence of super absorbent polymer was significant on spike weight in 2017, above-ground biomass in 2016, one hundred seed weight in 2016, and grain yield in 2017. There was no meaningful influence of super absorbent polymer on spike weight in 2016, above-ground biomass in 2017, 100 seed weight in 2017 and grain yield in 2016. Fertilizer treatments had significant influence on spike weight, above-ground biomass, 100 seed weight, and grain yield in both 2016 and 2017. The interaction between SAP and fertilizers had significant effect on above ground biomass in 2017. In both years, the highest spike weight, above ground biomass, 100 seed weight and grain yield was related to S3 (30 kg/ha), followed by S2 (15 kg/ha) and S1 (0 kg/ha), respectively. 100% application of fertilizer (F3) had obtained the maximum spike weight, above ground biomass, 100 seed weight and grain in both 2016 and 2017. Our data have shown that the applied SAP had a remarkable effect on corn growth and yield under different fertilization treatments, and its application of 30 kg/ha gave the best corn production index

Evaluate germination and seedling growth of three cultivars of fennel under diatomite and soil management

Fennel is a plant belonging to the Apiacea (Umbelliferae) family, and used by humans for a long time for medicinal purposes. In order to evaluate the influence of different materials on germination and seedling growth of three cultivars of fennel, an experiment was conducted in 2018. The cultivars of fennel were Isfahan, Yazd, and Shiraz in main plots, and three materials including 100% soil, 50% diatomite + 50% soil, and 100% diatomite in subplots, were analyzed in a split plot experiment based on a randomized complete block design (CRBD) with three replications. The highest total germination percentage, coefficient of velocity of germination, epicotile length, fresh epicotile weight and dry epicotile weight was related to Isfahan. The maximum speed of germination, mean germination time, fresh length and dry leaf weight was achieved in Shiraz cultivar. The higher values of total germination percentage, speed of germination and mean germination time were related to 100% soil, while application of 50% of soil + 50% of diatomite had obtained the maximum values of radicle length, epicotile length, fresh epicotile weight, dry leaf weight and dry epicotile weight. The maximum values of coefficient of velocity of germination and fresh leaf weight was achieved in application of 100% diatomite. It seems that application of 50% soil + 50% diatomite and Isfahan and Shiraz cultivars have a great potential of seed germination of seedling growth

The role of pretreatment parameters on seed germination and seedling growth of two fennel cultivars

Fennel is one of the most important medicinal and spice plants and has become one of the most important economical medicinal plants in Mediterranean, and the Middle East. The germination ability and percentage are fundamental characteristics which influence the viability of the plants. Prechilling has meaningful influence on coleoptile length, radicle length, seedling length, germination percentage, mean time for germination and germination rate, but uniformity of seed germination did not significantly influenced by it. The cultivar effect was significant on coleoptile length, radicle length, seedling length, germination percentage and germination rate. However, mean time for germination and uniformity of seed germination did not significantly affected by cultivar. All experimental characteristics, except uniformity of seed germination, significantly influenced by hormone. The maximum coleoptile length, radicle length, seedling length, germination percentage and germination ratio was related to 45 days moist prechilling treatment. Isfahan cultivar also had obtained the highest coleoptile and radicle length, seedling length, germination percentage and germination ratio compare to Shiraz cultivar. It seems that application of endogenous GA3+KI and BA+KI concentration, which is provided mostly by chilling treatment, is the most effective factor for breaking the seed dormancy. On the basis of the results, usage of 45 days moist prechilling accompanied with application of GA3+KI and BA+KI in Isfahan cultivar was appropriate

Survey the allelopathic effects of tobacco (Nicotiana Tabacum L.) on corn (Zea Mays L.) growth and germination

Allelopathy is the direct influence of chemical released from one plant on the development and growth of another plant. The trial accomplished in seed technology laboratory of Faculty of Agriculture, Islamic Azad University of Isfahan, in 2018. A factorial layout within completely randomized design with four replications was used. Treatments included plant organs extract (leaf, stem, root and total plant), and different tobacco extract densities includes four levels of 0%, 25%, 50% and 100%. Control treatment (0% of tobacco extract) had obtained the highest value of germination rate, germination percentage, coleoptile weight, radicle weight, radicle length and coleoptile length. The maximum germination rate, germination percentage, coleoptiles weight, radicle weight, radicle length and coleoptiles length was related to extract of stem extract which had meaningful differences with other treatments. Both radicle and coleoptile length decreased with increase in concentration of tobacco extract. Tobacco extract has negatively effects on corn seeds by decreasing the germination rate. Tobacco may increase the presence of secondary metabolites, such as alkaloids, all of which may have different effects on seed germination percentage. The highest germination percentage (91.91%), coleoptile weight (0.046 mg), radicle weight (0.0161 mg), radicle length (7.24 mm), and coleoptiles length (6.45 mm) was related to interaction between control treatment (0% of extract) and stem extract. It is concluded that the extract of Nicotiana tabacum had both inhibitory and stimulatory effects on seedling growth of Zea mays