Simultaneous Discharge Research Articles

Drainage demands of domestic washrooms in Hong Kong

Drainage demand estimation for an effective and healthy drainage stack design is examined in this study. Empirical expressions that incorporate building occupant load, simultaneous usage patterns and discharge flow attenuation along a horizontal pipe into the probable drainage load determination for a stack serving a number of domestic washrooms as installed in typical high-rise buildings in Hong Kong are proposed. Patterns of probable drainage demand and probable discharge flow in the stack are determined via Bayesian analysis and Monte Carlo simulations, respectively. The study outcome enables more effective sizing of a drainage stack for some residential buildings in a dense urban environment. Practical application: Providing a mathematical model for drainage load calculations, this study is a useful tool to aid drainage stack sizing for some high-rise residential buildings.

Cannabinoid Receptor Activation in the Nucleus Tractus Solitaries Produces Baroreflex-Like Responses in the Rat

The effects of cannabinoids on the baroreflex have been investigated in the nucleus tractus solitarii (NTS). In urethane-anesthetized rats, microinjection of the cannabinoid (CB) receptor agonist WIN 55212-2 (100 mM) into the NTS produced a short lasting decrease in arterial pressure (from 95.2 ± 2.9 to 76.2 ± 1.5, n=5, P<0.05) but no change in the heart rate. Another cannabinoid agonist, CP 55940 (100 mM) also caused hypotensive responses (from 90.2 ± 11.3 to 66.4 ± 12.3 mmHg, n=5, P<0.05). Simultaneous sympathetic nerve discharge recordings showed suppression prior to the arterial pressure lowering effect of these agonists. Microinjection of the cannabinoid receptor antagonist, AM 281 (70 mM) did not cause any significant change in arterial pressure (from 100.8 ± 12 mmHg to 108.1 ± 12.8 mmHg, n=5, P>0.05) though it inhibited the agonist-induced responses. The non-NMDA receptor antagonist, DNQX (4 mM) microinjections antagonized the actions of CB agonist WIN 55212-2. Furthermore, sinoaortic denervation attenuated the responses to CB agonists suggesting an intact baroreflex arc is necessary to elicit CB-mediated effects. Neither WIN 55212-2 nor AM 281, altered baroreceptor reflex activation by bolus phenylephrine (25 microg/kg) injections. These data suggest that cannabinoid receptors in the NTS are not involved in the tonic regulation of the arterial pressure but may have a modulatory role in the baroreceptor reflex integration.

Clinical Summaries

Clinical Summaries

Isotope tracing of submarine groundwater discharge offshore Ubatuba, Brazil: results of the IAEA–UNESCO SGD project

Results of groundwater and seawater analyses for radioactive ( 3H, 222Rn, 223Ra, 224Ra, 226Ra, and 228Ra) and stable (D and 18O) isotopes are presented together with in situ spatial mapping and time series 222Rn measurements in seawater, direct seepage measurements using manual and automated seepage meters, pore water investigations using different tracers and piezometric techniques, and geoelectric surveys probing the coast. This study represents first time that such a new complex arsenal of radioactive and non-radioactive tracer techniques and geophysical methods have been used for simultaneous submarine groundwater discharge (SGD) investigations. Large fluctuations of SGD fluxes were observed at sites situated only a few meters apart (from 0 cm d −1 to 360 cm d −1; the unit represents cm 3/cm 2/day), as well as during a few hours (from 0 cm d −1 to 110 cm d −1), strongly depending on the tidal fluctuations. The average SGD flux estimated from continuous 222Rn measurements is 17 ± 10 cm d −1. Integrated coastal SGD flux estimated for the Ubatuba coast using radium isotopes is about 7 × 10 3 m 3 d −1 per km of the coast. The isotopic composition ( δD and δ 18O) of submarine waters was characterised by significant variability and heavy isotope enrichment, indicating that the contribution of groundwater in submarine waters varied from a small percentage to 20%. However, this contribution with increasing offshore distance became negligible. Automated seepage meters and time series measurements of 222Rn activity concentration showed a negative correlation between the SGD rates and tidal stage. This is likely caused by sea level changes as tidal effects induce variations of hydraulic gradients. The geoelectric probing and piezometric measurements contributed to better understanding of the spatial distribution of different water masses present along the coast. The radium isotope data showed scattered distributions with offshore distance, which imply that seawater in a complex coast with many small bays and islands was influenced by local currents and groundwater/seawater mixing. This has also been confirmed by a relatively short residence time of 1–2 weeks for water within 25 km offshore, as obtained by short-lived radium isotopes. The irregular distribution of SGD seen at Ubatuba is a characteristic of fractured rock aquifers, fed by coastal groundwater and recirculated seawater with small admixtures of groundwater, which is of potential environmental concern and has implications on the management of freshwater resources in the region.

Cultivation of the intertidal brown algaHizikia fusiformis(Harvey) Okamura: mass production of zygote-derived seedlings under commercial cultivation conditions, a case study experience

Mariculture of the brown alga Hizikia fusiformis (Harvey) Okamura as an export-oriented human food has been there more for than 20 years in China. It is now one of the five major farmed algal species along the Chinese coast. Stable and sufficient supply of young seedlings for scaling up the cultivation has been a problem throughout the farming history of this species due to the unique dioecious life cycle and relatively short time window of sexual reproduction in nature. These two factors led to a practical difficulty in obtaining zygotes at identical developmental stage in viable amounts for seedling production. A key solution to this problem is to control the synchronization of the receptacle development and to realize the simultaneous discharge of male and female gametes, such that the fertilization rate could be greatly enhanced. Focusing on one of the farmed populations in this report, we present our results on mass production of seedlings using the synchronization technique on a large scale performed in 2007. Totally 5.5 hundred million embryos were obtained from 100 kg female sporophytes. The seedlings were raised up to 3.5 mm in length in greenhouse tanks over a month and were further grown in open sea for over 3 months at two experimental sites. The success of mass production of seedlings in this alga helped to lay the basis for future trials in other species in the genus of Sargassum that have identical life cycle.

Photoelectric features of vacuum-deposited a-Si:H/Alq3 blends

Using three electrode vacuum system for glow discharge of 5% SiH4+95% Ar gas mixture together with thermal evaporation of phosphorus or boric aced, the n- and p-type a-Si:H layers have been deposited. By co-evaporation of phosphorus or boric aced the conductivity of a-Si:H layers was changed in 10−11–10−3Ω−1cm−1 or 10−11 –10−8Ω−1cm−1 range, respectively. Blends of a-Si:H and tris-(8-hydroxyquinoline) aluminum (Alq3) have been vacuum-deposited by simultaneous glow discharge of 5% SiH4+95 % Ar gas mixture and thermal co-evaporation of Alq3. Photoluminescence spectrum of a-Si:H/Alq3 blend coincident with one of Alq3 was observed at room temperature.

A Study on Wall-Charge Behavior of Single-Sustain Waveform Based on $V_{t}$ Close-Curve Analysis in AC Plasma Display Panel

The wall-charge behaviors of the conventional and two types of single-sustain waveforms during address and sustain periods are investigated based on a simulated result and a Vt close-curve analysis. The single-sustain waveform means that the sustain pulse having both positive and negative voltage levels is applied only to the single-side electrode, i.e., the scan (Y) electrode in this paper, where the common (X) electrode remains grounded. In the single-sustain waveform, the address discharge characteristics were observed to be improved by applying a higher voltage level without causing a misfiring discharge during an address period. An asymmetric IR emission was observed for both positive and negative sustain pulses during a sustain period, which was caused by the simultaneous discharge, including the plate gap discharge between the scan (Y) and the address (A) electrodes only when applying the negative sustain pulse to the scan (Y) electrode.

Development, evaluation and interpretation of sediment rating curves for a Japanese small mountainous reforested watershed

Extensive reforestation using Cypress, Pinus and Cedar has widely taken place in Japan since early 1960s in attempt to fulfill national wood demands and control soil erosion. In 2004 one small headwater mountainous reforested watershed encompasses 4.8 ha was established in Mie Prefecture in Japan to monitor the hydrological response. Frequently and automatically collected values of discharge and suspended sediment concentration were examined for the main outlet and five other stations, spanning from June 2004 to July 2006. In the present study, the different functional linear and non-linear sediment rating curves analytical methods were employed in the investigation of ordinary and some transformed flow discharge–suspended sediment concentration relationships for the study watershed using from 48 to 162 simultaneous discharge–sediment records (2004–2006). According to the results of statistical analyses using different criteria and out of many types of regression functions and data transformation, power rating curve by least square regression on fourth root transformed flow discharge and suspended sediment concentration data performed well. Contrary to what is oft-reported, the best fitted rating curves to the entire data collected for each individual station excessively overestimated the suspended sediment concentration in the study area by 113–430%. The temporal and magnitude stratification of flow discharge and sediment data, flow components separation as well as employing bias correction factor did not improve the relationship, while better estimates were obtained when power regression was applied to the fourth root transformed data separated based on their locations on rising and falling limbs of hydrographs. Results also showed a complex suspended sediment concentration and flow discharge relationship in different subwatersheds of the study reforested watershed reflecting the effect of different physical local characteristics, sediment availability, contribution of various hydrologic cycle components, and subtle variation of soil hydrophobicity on runoff generation and consequently sediment supply.

Recovery of Boundary Image Sticking Using Aging Discharge in AC Plasma Display Panel

A full-white aging discharge process is proposed to recover permanent boundary image sticking in an AC plasma display panel. A simultaneous 100-h aging discharge in both boundary image sticking and nonimage sticking cells induced sputtering and redeposition of the MgO surfaces in both cell types, resulting in similar MgO surface morphologies. The luminance characteristics, including the infrared emission and chromaticity coordinates, of the boundary image sticking cells were also compared to those of the nonimage sticking cells. As a result, the full-white aging discharge was found to contribute to the recovery of permanent boundary image sticking cells.

Left Stellate Ganglion and Vagal Nerve Activity and Cardiac Arrhythmias in Ambulatory Dogs With Pacing-Induced Congestive Heart Failure

The purpose of this study was to determine the patterns of autonomic nerve activity in congestive heart failure (CHF). The relationship between autonomic nerve activity and cardiac arrhythmias in CHF is unclear. We implanted radiotransmitters in 6 dogs for continuous (24/7) simultaneous monitoring of left stellate ganglion nerve activity (SGNA), vagal nerve activity (VNA), and electrocardiography before and after pacing-induced CHF. Congestive heart failure increased both SGNA and VNA. The SGNA but not VNA manifested a circadian variation pattern. There was extensive sinus node fibrosis. We analyzed 2,263 episodes of prolonged (>3 s) sinus pauses (PSP) and 1,420 long (>10 s) episodes of paroxysmal atrial tachycardia (PAT). Most (95.3%) PSP episodes occurred at night, and 56% were preceded by a short burst of SGNA that induced transient sinus tachycardia. Long PAT episodes were typically (83%) induced by simultaneous SGNA and VNA discharge, followed by VNA withdrawal. Premature ventricular contractions and ventricular tachycardia were preceded by elevated SGNA. The reduction of sympathovagal balance at night in ambulatory dogs was due to reduced sympathetic discharge rather than a net increase of vagal discharge. The tachybrady syndrome in CHF might be triggered by an intermittent short burst of SGNA that resulted in tachycardia and sinus node suppression. Simultaneous sympathovagal discharge is a cause of long PAT episodes. These data indicate that there is an association between the specific patterns of autonomic nerve discharges and cardiac arrhythmia during CHF.

Construction of Larger Area Density-Uniform Plasmawith Collisional Inductively Coupled Plasma Cells

The plasma density and electron temperature of a multi-source plasmasystem composed of several collisional inductively coupled plasma(ICP) cells were measured by a double-probe. The discharges of theICP cells were shown to be independent of each other. Furthermore,the total plasma density at simultaneous multi-cell discharge wasobserved to be approximately equal to the summation of the plasmadensity when the cells discharge separately. Based on the linearsummation phenomenon, it was shown that a larger area plasma with auniform density and temperature profile could be constructed withmulti-collisional ICP cells.

Evaluation of ‘Discharge Units’ for Domestic Washrooms in Hong Kong

Probable maximum drainage loads in domestic drainage stacks in high-rise residential buildings in Hong Kong and other cities are currently estimated using the ‘discharge unit approach’, which is based on the probability of discharging all outlets simultaneously, with the design discharge flow rate of an outlet running at a limiting failure rate. However, direct application of this approach to load estimation without proper consideration of the probable discharge patterns and occupant load variations might not optimize drainage stack design. With recent survey results of drainage discharge patterns in some domestic washrooms, this study investigated the probable maximum flow rate in a stack serving a number of typical domestic washrooms in Hong Kong. The results showed that the occupant load served by an appliance and the simultaneous discharge patterns of the appliances in domestic washrooms had significant influences on the probable maximum drainage demand in the stack. Following the adopted design approach, the equivalent ‘discharge unit’ for a typical washroom was evaluated. The results are applicable to drainage stack designs for high-rise residential buildings in Hong Kong and other cities.

Retardation of electrical tree propagation by resin degradation

AbstractIn order to improve insight into the effect of delaminations between the conductor and the groundwall insulation on the ageing of high voltage rotating machinery insulation, the influence of the polymer degradation on tree growth has been studied. Simultaneous partial discharge measurements and photograhic observations have been conducted in order to investigate the effect of the degradation of the resin on electrical tree propagation. The photographic observation indicates that the degradation of the resin retards the tree propagation after the tree having failed to penetrate a mica barrier. As the resin is degraded and in part rendered conducting, the partial discharges change both in magnitude and in terms of phase resolved partial discharge patterns. These partial discharge measurements are promising to improve insight into the processes involved in winding insulation ageing, when photographic observations are unattainable. Moreover the differences found between various resins offer an explanation why various types of winding insulation have been found to differ in their capability to withstand thermal cyclic ageing. Copyright © 2006 John Wiley & Sons, Ltd.

Four-channel laser-triggered spark gap

Results on the simultaneous discharge initiations in a modified geometry of four-channel gas-filled spark gap with 45° angle of laser beam incidence on the electrode surface are presented. Laser triggering of the spark gap in our capillary-discharge driver CAPEX-U by a single laser system has been realised. A Q-switched YAG laser (λ = 1 064 nm) irradiated each of four spark gap channels with 200 mJ energy in a 6-ns pulse by use of a beam-splitting technique.

Formation of surface relief in plasma polymerized films

Surface thickness allocations of a polymer film grown in a glow discharge on a flat solid substrate were studied as the total effect produced by several simultaneous discharge processes: surface and volumetric mechanisms of polymerization, heat and mass transfer flows induced by the discharge and gravitational drift of the polymeric microparticles. Some kinds of motion of aerosols entrained by gas flows were visualized using laser probing. Scanning the film thickness in various directions at the substrate surface was carried out by multiple-beam microinterferometry. The results are presented for pure hexamethyldisiloxane and hexamethyldisilazane glow discharges, since these monomers were most capable of generating polymeric particles, though all the other monomers used gave qualitatively identical results. Peculiarities observed in a film relief are interpreted as results of deposition of the polymeric microparticles from corresponding flows of a dispersive gas–polymer mixture.

6.1: A Study on Wall Charge Behavior of Single Sustain Waveform Based on Vt Close Curve Analysis in AC-PDP

The wall charge behavior of the conventional and two types of single sustain waveforms are investigated based on a simulated result and Vt close curve analysis. The single sustain waveform means that the sustain voltage was alternately applied to the negative and positive voltage level on the single side electrode, that is, the scan (Y) electrode in this paper, where the common (X) electrode remains grounded. In the single sustain waveforms, the address discharge characteristics were improved during an address-period and an asymmetric intensity of the IR emission waveform was produced during a sustain-period compared with the conventional driving waveform. It was found that the improved address discharge characteristics was caused by the effect of the higher external applied voltage during an address-period than the accumulated wall charges during a reset-period, and an asymmetric IR intensity during a sustain-period was due to the simultaneous discharge including the plate gap discharge between Y and A electrode when applying the negative sustain pulse to the Y electrode.

The duration of arcing following late breakdown in vacuum circuit breakers

Vacuum interrupters occasionally show unexpected (late) breakdowns after current interruption. As a result, the interrupter conducts briefly, carrying a high-frequency current due to the discharge of various capacitances in the vicinity of the interrupter. Thanks to the capability of vacuum interrupters to interrupt such high-frequency current, the conduction period is very short (normally in the order of 10 microsecond). In the discussion around the assessment of such late break- downs (often termed non-sustained disruptive discharges in the standardisation literature) regarding the possibility of generation of overvoltage as a result of late breakdown in capacitive circuits, the duration of the conductive period is an important parameter. Experiments were carried Out, in which discharges of various single frequencies (72 kHz - 1.1 MHz) were generated following breakdown (spontaneous breakdowns as well as pre-strike) of two commercial vacuum breakers, stressed with ac voltages well above the rated value. From a statistical analysis, it is demonstrated that the dura- of the discharge depends strongly on the discharge current frequency. At higher frequencies, the duration of the discharge tends to be shorter than at lower frequencies due to the domi- nance of thermal reignitions of the arc at high values of dl/dt over dielectric reignitions, observed only at lower frequencies. For practical circuits, allowing simultaneous discharge from various circuit parts, it was observed that the highest frequency component determines the arc duration. Durations of up to 15 us were observed. This duration is too short to allow significant overvoltages to develop in standard capacitive circuits, the main candidate switching duty to be troubled with overvoltage generation.

Detection of electrical tree propagation by partial discharge measurements

AbstractThe partial discharge (PD) activity during propagation of electrical treeing in epoxy resin is described. The electrical trees grew in needle‐plane samples without and with an internal barrier up to the final breakdown. The simultaneous tree growth and discharge activity show a correlation between the propagation state of the tree and the thereby measured PD. Especially, the changes in the tree structure can clearly be detected. Based on these characteristics a new model describing tree growth is presented. It appears that measurements from machine insulation can be interpreted in terms of the PD pattern. Copyright © 2005 John Wiley & Sons, Ltd.

CHARGE AND DISCHARGE CHARACTERISTICS OF A THERMAL ENERGY STORAGE DEVICE

This article describes an experimental investigation on the thermal characteristics of a thermal energy storage device. It utilizes the superior heat transfer characteristics of wickless heat pipes and eliminates drawbacks found in the conventional thermal storage tank. This study purports to examine the functions of a thermal energy storage device having three operating modes, i.e., charge, discharge, and simultaneous charge and discharge. Different heat transfer mechanisms are identified in the thermal energy storage device under different operating modes. The thermal performance with alcohol and water as working fluid are also explored in the thermal energy storage device. The results show that a thermal energy storage device employing alcohol as the working fluid provides better performance. The system gives optimum charge and discharge performance under 35%–40% fill ratio and displays optimum charge efficiency of 73% and optimum discharge efficiency of 85%.

Degradation of Aqueous Phase Polychlorinated Biphenyls (PCB) Using Pulsed Corona Discharges

AbstractThe efficacy of pulsed corona discharges, an effective technique for removal of small aromatic and volatile organic compounds in water, to degrade aqueous phase polychlorinated biphenyls (PCB) was tested. Experiments were conducted on the model PCB compound, 2,2′,4,4′- tetrachlorobiphenyl at its solubility limit (68 ppb) in water. The effects of various reactor configurations featuring liquid and combined liquid/gas discharges on the degradation rate and possible degradation mechanisms of the PCB congener were determined. The pulsed corona reactor led to nearly 70% degradation of the PCB congener within 60 min. Increased degradation rates due to the Fenton’s reactions were found upon the addition of ferrous salts in solution, and the degradation rate of the PCB was higher than those of phenol and nitrobenzene in the absence of ferrous salts. The two different reactor configurations tested, including direct discharge in water and simultaneous gas-liquid discharge, gave the same rate of PCB degradation in the Fenton’s case, thus raising the possibility that the PCB degradation mechanisms in both reactors are the same. The effect of the high voltage electrode material on the degradation of PCB was evaluated by performing experiments with electrodes made of either platinum or a nickel-chromium alloy.