Formation of quasi-free and bubble positronium states in water and aqueous solutions

It is shown that in aqueous solutions a positronium atom is first formed in the quasi-free state, and, after 50-100 ps, becomes localized in a nanobubble. Analysis of the annihilation spectra of NaNO3 aqueous solutions shows that the hydrated electron is not involved in the positronium (Ps) formation

Domain wall dynamics of the Ising chains in a transverse field

We show that the dynamics of an Ising spin chain in a transverse field conserves the number of domains (strings of down spins in an up-spin background) at discrete times. This enables the determination of the eigenfunctions of the time-evolution operator, and the dynamics of initial states with domains. The transverse magnetization is shown to be identically zero in all sectors with a fixed number of domains. For an initial state with a single string of down spins, the local magnetization, the equal-time and double-time spin-spin correlation functions, are calculated analytically as functions of time and the initial string size. The domain size distribution function can be expressed as a simple integral involving Bessel functions.Comment: 4 pages with three figure

Ultrastructure of the epithelial cells and oleo-gumresin secretion in Boswellia serrata (Burseraceae)

The ultrastructure of epithelial cells of oleo-gumresin ducts in Boswellia serrata, the source of Indian olibanum, is described. Oleo-gumresin ducts are present in primary and secondary phloem. The duct lumen forms an enlarged apoplastic space surrounded by epithelial cells. The epithelial cells are rich in dictyosomes, lipid bodies, mitochondria with dilated cristae, multivesicular bodies, osmiophilic materials, plastids and vesicIes. Plastids have poorly developed internal membranes. Dictyosomes and plastids are possible sites of resin synthesis. The gum component of the exudate is formed in dictyosomes and from the outer layers of the inner tangential wall (wall facing the duct lumen). This wall is replenished from inside by the activity of dictyosomes. The secretory materials are transported to the apoplast by granulocrine and eccrine secretion. They migrate through the loose microfibrils of the inner tangential wall into the duct lumen. Rarely, epithelial cells of young ducts have rudimentary plasmodesmata on the inner tangential wall which may be channels for passage of secretory materials into the duct lumen

Effect of tool pin diameters on friction stir welding of Aluminium alloy 5083

Friction stir welding is a solid-state welding process invented by the welding institute (TWI) of UK in 1991. The main objective is to study the effect of rotational speed and tool pin diameters of straight cylindrical tool on mechanical properties of Aluminium Alloy5083. Three different tool pin diameters (2.5mm,4mm,6mm) have been used to fabricate the joints at three different tool rotational speeds (710,1120 and 1400rpm) by keeping the constant welding speed and axial force. Tensile properties and micro hardness of the joints have been evaluated

Dynamics of Metallic Particle Contamination in Gas Insulated Substation (GIS)

This paper analyses the movement of free conducting particles inside a single phase Gas Insulated Bus duct(GIB).A two dimensional mathematical model was proposed for determining the movement pattern of metallic particle in GIB by considering all the forces acting on the particle like gravitational, drag and the electric field forces. These particles may be free to move in the electric field or may be fixed on the conductors, thus enhancing local surface fields. Electric fields at the instantaneous contaminated particle locations were computed using Charge Simulation Method (CSM).To determine the particle trajectory in a single phase Gas Insulated Bus duct (GIB), an enclosure diameter 152 mm and conductor diameter 55 mm is considered. The simulation of the particle movement was carried under different AC voltage levels like 100KV, 132KV, 145KV and 175KV class enclosure of GIB for aluminum, copper and silver particles. The results of the simulation have been presented and analyzed in this paper

IEEE 802.15.4-PHY Packet Detection and Transmission System With Differential Encoding For Low Power IoT Networks

Synchronization is the first operation in a digital base band receiver. The accuracy of the synchronizer shapes up the performance of the base band receiver. Synchronization is broadly divided into Carrier Frequency and Phase Synchronization, Symbol Timing and Frame Synchronization. If number of false detections in frame synchronization are high then large amount of power is wasted for processing unwanted packets. In this paper, we are proposing a packet detection and transmission system with differential encoding for low power IoT networks which reduces the number of false packet detections compared to existing preamble detection techniques. The proposed frame synchronization method decides packet is valid or not by cross correlating received packet with fixed preamble sequence and determine its boundaries. The proposed system is analyzed with smart metering power data and corresponding probabilities of packet missing and false detection, power consumption and bit error rate are analyzed. At 3 dB SNR the number of false detections are reduced by 170 compared to conventional correlation method thereby saving 15.8 % of processing power at receiver

Prevalence of subclinical hypothyroidism in children and adolescents of northern Andhra Pradesh population and its association with hyperlipidemia

Background: The thyroid dysfunction particularly, subclinical hypothyroidism (SCH) is quite a common clinical condition in paediatric population but there is limited data available regarding its prevalence in children and adolescents in our population. The present study was aimed to know the prevalence of thyroid dysfunction particularly SCH in children and adolescents of northern Andhra Pradesh population and its association with hyperlipidemia.Methods: A retrospective study of 600 subjects (Children=272, Adolescents=328) between 6-19 years of age were included and the following parameters were examined: age, sex, total triiodothyronine (tT3), total tetraiodothyronine (tT4), thyroid stimulating hormone (TSH), total cholesterol, triglycerides (TGL), LDL and HDL cholesterol. The subjects were divided into group I and group II on the basis of age (in years), subjects between 6- ≤12 years age were grouped as group I and 12-≤19 years were as group II.Results: Out of 272 children and 328 adolescents studied, the prevalence of thyroid dysfunction was found to be 9.9% and 10.4 % respectively. The prevalence of subclinical hypothyroidism in children was 7.7% where as 4.9% in adolescents. In both the groups, females were predominantly affected with thyroid dysfunction as compared to males. Significantly elevated serum levels of total cholesterol, TSH and TGL were observed in SCH subjects when compared to euthyroid subjects (p<0.05). Statistically significant lower levels of HDL cholesterol were found in SCH as compared to euthyroids (p<0.05). However, no difference was noticed in the levels of total T3, total T4 and LDL cholesterol between SCH and euthyroids.Conclusions: The prevalence of thyroid dysfunction was found to be 10.2% in study population. SCH was observed in 7.7 % and 4.9% respectively in children and adolescent groups. Subclinical hypothyroidism (SCH) was the most predominant thyroid dysfunction found in our studied population with a prevalence of 6.2% (both children and adolescents). Correction of thyroid dysfunction particularly SCH in early childhood is highly essential to prevent the impairment of psychomotor and cognitive development

Seismic Effects in F2 Region Related to Electron Temperature

The effect of earthquakes in the ionospheric F2 range was studied using the Indian satellite SROSS-C2 data on the cosmic electron temperature around the Indian sector in the ranges 0-34 ° N and 40-100 ° E for the period 1995-1997. Five episodes of earthquakes were analyzed and the observed anomalies at an average electron temperature were 29 to 10% higher than in the preceding days, and 16 to 4% higher than on days after the earthquake, and a latitudinal variation of this temperature. It is shown that the increase in this temperature was the maximum on the day preceding the earthquake, and for several hours before and after it. The anomalies observed around (in the ± 2-degree latitude range) were the epicenter of the earthquake. They were probably observed due to electromagnetic radiation during the earthquake activity. The period from 1995 to 1997 for this study was taken as a period of quiet geomagnetic conditions