Cuckoo search algorithm as an optimizer for optimal reactive power dispatch problems

This paper presents the application of Cuckoo Search Algorithm (CSA) in optimizing the control variables of power system operation in solving the optimal reactive power dispatch (ORPD) problem. CSA is inspired by the parasitic behavior of Cuckoo birds in reproduction process based on the probability for a host bird in discovering an alien egg in its nest. The implementation of CSA in determining the optimal value of control variables such as generator bus voltages, transformer tap setting and shunt reactive elements in order to obtain the minimize loss in the system. In this paper, IEEE-30 bus system is utilized to show the effectiveness of CSA and then the comparison with other nature inspired algorithms will be presented

Quasiperpendicular high Mach number Shocks

Shock waves exist throughout the universe and are fundamental to understanding the nature of collisionless plasmas. Reformation is a process, driven by microphysics, which typically occurs at high Mach number supercritical shocks. While ongoing studies have investigated this process extensively both theoretically and via simulations, their observations remain few and far between. In this letter we present a study of very high Mach number shocks in a parameter space that has been poorly explored and we identify reformation using in situ magnetic field observations from the Cassini spacecraft at 10 AU. This has given us an insight into quasi-perpendicular shocks across two orders of magnitude in Alfven Mach number (MA) which could potentially bridge the gap between modest terrestrial shocks and more exotic astrophysical shocks. For the first time, we show evidence for cyclic reformation controlled by specular ion reflection occurring at the predicted timescale of ~0.3 {\tau}c, where {\tau}c is the ion gyroperiod. In addition, we experimentally reveal the relationship between reformation and MA and focus on the magnetic structure of such shocks to further show that for the same MA, a reforming shock exhibits stronger magnetic field amplification than a shock that is not reforming.Comment: Accepted and Published in Physical Review Letters (2015

Histological changes in male accessory reproductive organs in rats exposed to cigarette smoke and the protective effect of honey supplementation

The effect of cigarette smoke (CS) on histology of male accessory  reproductive organs and the possible protective effect of honey  supplementation in rats were investigated in this study. Rats received distilled water, honey, CS exposure or honey plus CS exposure. Honey (1.2 g/kg body weight/day) was administered by gavage and CS exposure (3 times per day) was done in a chamber for 13 weeks. CS exposure significantly increased relative weight of epididymis and ventral prostate. There were also  significantly increased number of clear cells and epithelial height of cauda epididymis as well as severe interstitial oedema and decreased epithelial height of prostate gland. However, with the supplementation of honey, these histological changes were significantly reversed suggesting the protective effect of honey against the toxic effect of CS on male accessory reproductiveorgans in rats

Suprathermal electrons at Saturn's bow shock

The leading explanation for the origin of galactic cosmic rays is particle acceleration at the shocks surrounding young supernova remnants (SNRs), although crucial aspects of the acceleration process are unclear. The similar collisionless plasma shocks frequently encountered by spacecraft in the solar wind are generally far weaker (lower Mach number) than these SNR shocks. However, the Cassini spacecraft has shown that the shock standing in the solar wind sunward of Saturn (Saturn's bow shock) can occasionally reach this high-Mach number astrophysical regime. In this regime Cassini has provided the first in situ evidence for electron acceleration under quasi-parallel upstream magnetic conditions. Here we present the full picture of suprathermal electrons at Saturn's bow shock revealed by Cassini. The downstream thermal electron distribution is resolved in all data taken by the low-energy electron detector (CAPS-ELS, <28 keV) during shock crossings, but the higher energy channels were at (or close to) background. The high-energy electron detector (MIMI-LEMMS, >18 keV) measured a suprathermal electron signature at 31 of 508 crossings, where typically only the lowest energy channels (<100 keV) were above background. We show that these results are consistent with theory in which the "injection" of thermal electrons into an acceleration process involves interaction with whistler waves at the shock front, and becomes possible for all upstream magnetic field orientations at high Mach numbers like those of the strong shocks around young SNRs. A future dedicated study will analyze the rare crossings with evidence for relativistic electrons (up to ~1 MeV).Comment: 22 pages, 5 figures. Accepted for publication in Ap

Looks can be deceiving: adrenal Teratoma causing diagnostic difficulty

Teratomas are unusual tumours that derived from totipotent cells with their origin from more than one or usually all three germ cells. Here authors are presenting a case of primary retroperitoneal tumour that is a rare clinical entity. A 19-year-old male presented with right lumbar pain and was found to have complex cyst with large calcification in right adrenal gland on imaging. Intraoperatively, he was found to have a solid mass with areas of soft consistency, which was excised en bloc. On gross examination, the cyst contained pieces of bone, few teeth, and hairs entangled in mucinous material. On histological evaluation, it was confirmed to be mature teratoma arising from the right adrenal gland. He made uneventful recovery and was kept well on annual follow-up

Analysis of optimum combination of integrated crop-livestock enterprise in North-West, Nigeria

The study was conducted to determine the optimum combination of integrated crop-livestock enterprises in north-west, Nigeria. Primary data were obtained through structured questionnaire and interview schedule. A multi-stage sampling procedure was employed to select 3 states, 3 zones, 21 LGAs, 84 villages, and 428 crop-livestock farmers made up of 178, 128 and 122 farmers in Kaduna, Kano and Katsina states respectively. Descriptive statistics and Data Envelopment Analysis (DEA) was used to achieve the objective of the study. The results of socio-economic characteristics showed that about 89% of the pooled farmers were male with mean age of 48 years and household size of 10 persons per farmer. The findings from DEA revealed the mean total efficiency, pure efficiency and scale efficiency of 0.79, 0.91 and 0.86 respectively. DEA results further indicated that farmers can reduce the quantity of farm size, labour, seed, fertilizer, manure and agrochemical inputs by 0.2, 12.9, 17.6, 6.6, 35.9 and 26.4 %, respectively. Results further specified that 17.3, 26.25 and 56.5 % of farmers operated at optimal, sub-optimal and super-optimal scale, respectively. Tobit regression model used to determine factors influencing technical efficiency established that coefficients of age (0.0210), marital status (0.0016), household size (0.0616), education level (-0.1247), farming experience (0.1412), extension contact (-0.2548) and cooperative membership (-0.1102) were statistically significant variables at different level of probability. There should be synergy between crop and animal scientists; extension agents and agricultural economists to bring into bearing the needs for farmers to imbibe integrated crop-livestock farming to achieve optimum level of efficiency

Effect of dried and extrudate of bitter gourd fruit on epithelial microflora in raw chicken legs meat

Plants have been used recently to eliminate bacterial growth in food products. This study was undertaken to test the in vitro sanitizing effect of crude extract from bitter gourd (BG) fruit on the growth of native microorganisms in raw chicken leg meat. Hot air dried BG and extrudate extracts at 1% concentration and exposure times of (5, 10 and 15 min) were used to treat the samples using dilution method. Results showed that BG extrudate had a slightly stronger bactericidal activity against the microflora than the B.G. hot air drying treatment, especially, on E. coli at all exposure time. Overall, there is no significant difference between the treatments; Total Plate Count (TPC), Escherichia coli, Bacillus cereus, Staphylococcus aureus. The best reduction time of microflora by hot air dried extract was at (15 min) except for B. cereus was at (5 min) and for extrudate extract was at (5 min) except for E. coli was at (10 min). In conclusion, bitter gourd extract could be used as an important natural sanitizer for rinsing raw food matrials such chicken meat

Fattening and Some Carcass Characteristics of Karadi Lambs Raised on Concentrate or Pasture

Fourteen weaned Karadi lambs (4-5 months old) and weighing 26.5±0.33 Kg were used to evaluate the effect of feeding on concentrate or on pasture with free access to barley on fattening and some carcass characteristics. Lambs were slaughtered when each individual lamb reached its designated body weight (35 kg). Significantly (p&lt;0.05) average daily gain in weight was higher in the lambs maintained on concentrate (140.11±10.48) compared to those fed on pasture and supplemented with barely (88.23±13.20). There was no significant differences between the two groups for dressing percentage, all cuts of the carcass and edible and non edible organs, while lambs fed on concentrate exhibited thicker fat over L. dorsi muscle and had greater rib eye area compared to lambs kept on pasture and supplemented with barely

Interpretation of Nuclear Quadrupole Resonance Spectra in Doped La2_2CuO4_4

The nuclear quadrupole resonance (NQR) spectrum of strontium doped La$_2$CuO$_4$ surprisingly resembles the NQR spectrum of La$_2$CuO$_4$ doped with excess oxygen, both spectra being dominated by a main peak and one principal satellite peak at similar frequencies. Using first-principles cluster calculations this is investigated here by calculating the electric field gradient (EFG) at the central copper site of the cluster after replacing a lanthanum atom in the cluster with a strontium atom or adding an interstitial oxygen to the cluster. In each case the EFG was increased by approximately 10 % leading unexpectedly to the explanation that the NQR spectra are only accidentally similar and the origins are quite different. Additionally the widths of the peaks in the NQR spectra are explained by the different EFG of copper centres remote from the impurity. A model, based on holes moving rapidly across the planar oxygen atoms, is proposed to explain the observed increase in frequency of both the main and satellite peaks in the NQR spectrum as the doping concentration is increased