We study Q-balls associated with local U(1) symmetries. Such Q-balls are expected to become unstable for large values of their charge because of the repulsion mediated by the gauge force. We consider the possibility that the repulsion is eliminated through the presence in the interior of the Q-ball of fermions with charge opposite to that of the scalar condensate. Another possibility is that tw...

Nowadays, electrospinning has emerged as a widespread technology to produce nanofibers and best candidates for many significant applications. The most important challenge is to attain uniform nanofibers. In these cases, controlling the production of electrospun nanofiber becomes important. However, Analysis dynamics of jet formation and its instability is difficult during the process. For makin...

Using the result that an electric charge-magnetic charge system carries an internal field angular momentum of eg/4π we arrive at two restrictions on magnetic monopoles via the requirement of angular momentum quantization and/or conservation. First we show that magnetic charge should scale in the opposite way from electric charge. Second we show that free, unconfined monopoles seem to be inconsi...

one of the most dazzling events in the atmosphere is lightning. during updrafts in the life cycle of cumulus clouds, collision of graupels and ice crystals in the presence of liquid water results in vertical separation of electrical charges and lightning. there are four types of lightening depending on the location of discharge. the first type is cloud-to-ground lightning or fork lightning that...

Water droplets are generated by sonic spray, transferred into vacuum through a capillary interface, and then passed through two image charge detectors separated by a drift region. The image charge detectors measure the charge and velocity of each droplet. For around 1% of the droplets, the charge changes significantly between the detectors. In some cases it increases, in others it decreases, an...

Development of materials with an antimicrobial activity is fundamental for different sectors, including medicine and health care, water and air treatment, and food packaging. Electrospinning is a versatile and economic technique that allows the incorporation of different natural, industrial, and clinical agents into a wide variety of polymers and blends in the form of micro/nanofibers. Furtherm...

Magnetic nanofiber has been widely applied in biomedical fields due to its distinctive size, morphology, and properties. We proposed a novel needleless electrospinning method to prepare magnetic nanofibers from the self-assembling "Taylor cones" of poly(vinyl pyrrolidone) (PVP)/Fe₃O₄ ferrofluid (PFF) under the coincident magnetic and electric fields. The results demonstrated that a static PFF R...