The development of non-circular cross-section in-building drains with a reduced invert cross-section will allow efficient low-flow performance by maintaining flow depth to aid solid transport. An enlarged upper cross-section will allow higher water and air flow rates to be handled. Such developments are essential if the water-conservation benefits of a reduced toilet flush volume are to be realized. The paper demonstrates the background to such solutions based on the ovoid or 'egg-shaped' cross-section sewers that have been used in Europe and the US for two centuries. The steady flow capacity of the ovoid shape is demonstrated, while the reduced wave attenuation in ovoid cross-sections is simulated, using the method of characteristics solution to the wave equations, and it is shown to be an indicator of improved overall solid transport efficiency. Solid transport results demonstrate the efficiency of non-circular sections and provide a direct comparison with the use of reduced-diameter circular drains already acceptable in conjunction with reduced water usage.

The satisfactory removal of faecal and other waste by w.c. flushing and solid transport within a branch drain is a prerequisite of building drainage system design. The increasing importance of water conservation has led to renewed interest in the possibilities for reductions in overall building use through reduced w.c. flush volume operation. Current UK and international legislation has led to the 6 L flush being regarded as the upper acceptable limit, with consideration being given to further reductions to 4 L and below. Maintaining the operational integrity of the drainage system will require an understanding of both w.c. design and transport mechanisms to ensure solid clearance and the avoidance of solid deposition and the consequent disruption to the building user. It is necessary to regard the w.c. and the branch drain as a system. This paper analyses a major data set that includes a wide range of w.c. flush volumes as well as consideration of branch drain cross-sectional area and shape. Data for low flush volume operation with a parabolic cross-section branch drain is presented. Conclusions are drawn that indicate that low flush volume operation is feasible provided drain slope and cross-sectional area and shape are fully considered. The degree of slope enhancement required as flush volume is decreased is demonstrated.

Water conservation will become a design requirement in the provision of new build in response to both demographics and climate change. Measures to reduce per-capita water usage in both domestic and commercial buildings will reduce disproportionately the flow available to remove waste solids flushed into branch drains within or close to the building. The reduced flow loading of the sewer network will of necessity represent a lower percentage change. There is therefore a need to understand fully the mechanisms of solid transport close to the head of the network where solid transport takes place within an attenuating discharge flow and to provide design guidance. Extensive laboratory research and a major study of faecal and waste solid transport in installed systems are presented as a basis for identifying a suitable model for deformable solid transport. The results of these programmes have been confirmed by simulation models developed independently that in turn provide the basis for predicting the capability of low flush volume and dual flush toilets to transport deformable solids over acceptable lengths of drain within or close to the building. These simulations are available as assessment tools to aid system design and the development of codes and regulations recognizing the importance of waste removal within a water conservation-conscious environment.

Water conservation is a prerequisite to a sustainable built environment. The effect of reductions in water throughflow on the operation of building drainage systems must be understood and incorporated into the design of building drainage networks. The water consumption represented by water closet (w.c.) usage identifies es w.c. flushing as the major contributor of waste water from domestic and commercial buildings and hence the water closet becomes the defining appliance in terms of identifying appropriate drain sizing techniques. Within the building envelope w.c. discharge flow is subject to wave attenuation which has a predominant role to play in the final solid transport distance expected following w.c. operation. This paper discusses the interaction of the parameters governing solid transport and illustrates the application of mathematical modelling techniques to predict transport distance under water conservation criteria.

Pressure transient propagation within building services utility systems is an inevitable consequence of any change in the system operating condition. In common with a wide range of pressure surge applications, these conditions may be analysed and modelled by solving the applicable St Venant equations numerically via the method of characteristics. This paper presents the underlying basis for such models and presents applications within building services utility systems that feature trapped or entrained air as a major modifier of either the transient propagation or the system boundary conditions. In particular, surge pressures exacerbated by the effect of trapped or entrained air are considered, including dry riser and sprinkler applications. The role of entrained air in the occurrence of physical injury following the violent fracturing of a w.c. bowl is discussed and explained in terms of a transient analysis.

A rat-head exposure system has been developed for Wireless Technology Research, LLC (WTR) through a contract with Dr. C.K. Chou who was at the City of Hope National Medical Center during the development of the system. In the first phase of the development of the system the finite-difference time-domain (FDTD) method was used to calculate the specific absorption rates (SARs) in ellipsoidal rat models with simulated fields from different loop antennas located at various distances from the models. From this analytical work a 3 cm x 1 cm rectangular loop was designed with optimized energy coupling and impedance matching.Sprague Dawley rats were then exposed using the 3 cm x 1 cm loop antennas, tuned either to 837 MHz or 1957 MHz for the determination of SAR distribution utilizing the thermographic technique. In addition, point SARs in the brains of restrained rats were measured using fiber optic probes. The calculated and measured SAR patterns were in general agreement. The average brain-to-whole body SAR ratio was 20 to 1 for both frequencies. At 837 MHz, the maximum measured SAR in the restrained rat brain was 51 W/kg/W in the cerebellum and 40 W/kg/W at the top of the cerebellum. For a maximum SAR of 10 W/kg, only 0.2 W input power to the loop is required. The overage brain SAR in a 300-g medium size rat for 0.2 W input power is estimated to be 4.8 W/kg.The exposure system has been used to expose Sprague Dawley rats to 837 MHz using analog, TDMA, and CDMA cellular phones as generators of the signals to the loop antennas. At this time, the longest duration of exposure has been 3 hours.

Electrochemical treatment (EChT) with direct current delivered through implanted electrodes has been used for local control of solid tumors in humans. This study tested the hypothesis that rat breast cancer responses to EChT are dependent on electrode spacing and dose, and explored suitable parameters for treating breast cancers with EChT. Rat breast cancers were initiated by injecting 1 × 106 MTF‐7 cells to the right mammary gland fat pad of Fisher 344 female rats. The rats were randomly divided into designated experimental groups when the tumors grew to approximately 2 × 2 × 2 cm. One hundred and thirty rats were used for a survival study and 129 for a pathology study. A 4‐channel EChT machine was used to administer coulometric doses. The survival study indicated that local tumor control rate is less than 40% in the 40 coulomb (C) and 60 C groups and more than 70% in the 80 and 100 C groups. Sixty six rats died of primary tumors, including all 10 rats in the control group. Once a rat's primary tumor was controlled, no recurrence was found. The main reason for terminating the primary tumor‐free rats (51) was lymph node metastasis. Thirteen tumor‐free rats survived for more than 6 months. The pathology study showed a significant dose effect on EChT induced tumor necrosis. At 10, 20, 40, and 80 C, the fraction showing necrosis were 39.7, 52.3, 62, and 77.7%, respectively (P ≤ 0.001). Electrodes spacing was not an important factor within a given range. At 5, 10, and 15 mm spacing, the fraction showing the necrosis were 54.1, 60.4, and 59.2%, respectively (P = 0.552). The overlap rate of necroses was similar in the 5 and 10 mm groups (82.5 and 85%) and lower in the 15 mm group (65%). We conclude that the tumor responses to EChT, local control, survival rates, and necrosis percentages were significantly increased with increasing dose. The changes in electrode spacing (3, 5, and 10 mm) did not significantly affect the tumor responses to EChT within the same dose. For a diameter of 2.0–2.5 cm rat breast cancer, EChT should be applied with 5–10 mm spacing and a minimum dosage of 80 C. Bioelectromagnetics 22:205–211, 2001. © 2001 Wiley‐Liss, Inc.

The flow of water and entrained air within building drainage and vent systems and the rainwater flows in conventional or siphonic rainwater systems are all examples of unsteady flow that may be represented by the St. Venant equations of continuity and motion. Thus these time dependent flow conditions are amenable to solution by application of the method of characteristics linked to a finite difference numerical scheme; a technique that has been shown to be suitable as a basis for computer simulation of system operation.This paper will illustrate the common nature of these apparently disparate flow regimes, emphasising the common solution and simulation techniques appropriate. Simulation and validation examples are presented and the potential impact upon system design methods outlined.

The Water Supply (Water Fittings) Regulations 1999, introduced to encourage innovation and water conservation, will profoundly affect building drainage design. Reduced shower flows and washing machine volumes and 6/3 litre dual flush wc operation will lower through flows, while drop valve wc flushing will affect system operation. Design for water conservation will necessitate the prediction of wave attenuation and its impact on solids transport and, without the safety factor provided by higher throughflows, simulations will ensure efficient design for minimal solid deposition. A simulation employing the method of characteristics solution of the St Venant equations and empirical relationships between solids velocity and the surrounding flow conditions is presented to predict solids transport performance within networks specified by slope, diameter, material, and appliance distribution and discharge characteristics.

The aim of this project was to develop an animal exposure system for the biological effect studies of radio frequency fields from handheld wireless telephones, with energy deposition in animal brains comparable to those in humans. The finite-difference time-domain (FDTD) method was initially used to compute specific absorption rate (SAR) in an ellipsoidal rat model exposed with various size loop antennas at different distances from the model. A 3 x 1 cm rectangular loop produced acceptable SAR patterns. A numerical rat model based on CT images was developed by curve-fitting Hounsfield Units of CT image pixels to tissue dielectric properties and densities. To design a loop for operating at high power levels, energy coupling and impedance matching were optimized using capacitively coupled feed lines embedded in a Teflon rod. Sprague Dawley rats were exposed with the 3 x 1 cm loop antennas, tuned to 837 or 1957 MHz for thermographically determined SAR distributions. Point SARs in brains of restrained rats were also determined thermometrically using fiberoptic probes. Calculated and measured SAR patterns and results from the various exposure configurations are in general agreement. The FDTD computed average brain SAR and ratio of head to whole body absorption were 23.8 W/kg/W and 62% at 837 MHz, and 22.6 W/kg/W and 89% at 1957 MHz. The average brain to whole body SAR ratio was 20 to 1 for both frequencies. At 837 MHz, the maximum measured SAR in the restrained rat brains was 51 W/kg/W in the cerebellum and 40 W/kg/W at the top of the cerebrum. An exposure system operating at 837 MHz is ready for in vivo biological effect studies of radio frequency fields from portable cellular telephones. Two-tenths of a watt input power to the loop antenna will produce 10 W/kg maximum SAR, and an estimated 4.8 W/kg average brain SAR in a 300 g medium size rat.

The TP53 tumor suppressor protein (formerly known as p53) responds to a wide variety of environmental insults. To evaluate the safety of cellular telephones, TP53 responses in human fibroblast cells were studied after exposure to 837 MHz microwaves. Cells were exposed in a temperature-controlled transverse electromagnetic (TEM) chamber to a specific absorption rate (SAR) of 0.9 or 9.0 W/kg at 837 MHz continuous-wave (CW) microwave irradiation for 2 h. The TP53 protein levels were measured by Western blot at 2, 8, 24 and 48 h after treatment. The TP53 protein levels in microwave-treated cells, sham-treated cells, and untreated cells remained unchanged relative to each other at all times tested (Fisher test and Student-Newman-Keuls test, P > 0.05). No morphological alterations were observed in microwave-treated cells compared to sham-treated cells. We conclude that TP53 protein expression levels in cultured human fibroblast cells do not change significantly during a 48-h period after exposure to 837 MHz continuous microwaves for 2 h at SAR levels of 0.9 or 9.0 W/kg.

The specific absorption rate (SAR) distributions in radio frequency–exposed solutions containing suspended or plated cells in vessels used for in vitro research were calculated by the finite-difference-time-domain method, graphed in color, and statistically analyzed in terms of uniformity for application to research on safety of wireless devices. The uniformity of SAR was quantified by visual inspection of colored plots, histograms, means, standard deviations, and maximums for the cell suspensions exposed in test tubes, Petri dishes, and rectangular flasks. Exposure sources included plane waves, transverse electromagnetic (TEM) cells, and striplines used at frequencies of 837, 2450, or 3,000 MHz. The results demonstrated that the most nonuniform SARs for plated or suspended cells in solution occurred for exposures of test tubes and rectangular flasks with plane waves, polarized for maximal absorption. The most uniform SARs for a layer of cells occurred for exposure of Petri dishes oriented for weakest coupling to the fields in a TEM cell. Additional improvement in uniformity was found to be possible by restricting the edge of the layer of cells from being too near the edges of the dish. It was not possible to achieve satisfactory uniformity in the SAR in cell suspensions exposed in standard vessels to any of the sources. The best but not satisfactory SAR uniformity was observed for cells suspended in the lowest 1-ml volume of the liquid contained in a test tube exposed at the bottom in a TEM cell. Experimental measurements of average SAR by temperature change for this case varied from 18% higher to 26% lower than finite difference time domain–derived values. The most uniform SAR distribution for cell suspensions in nonstandard containers was found for a rectangular slab configuration exposed in a stripline with the plates separated from the media by a thin layer of insulation. It is possible to experimentally implement this model by placing a fluid-filled thin-wall rectangular container tightly between the plates of a stripline. Bioelectromagnetics 20:21–39, 1999. © 1999 Wiley-Liss, Inc.

To develop cancer electrochemical treatment (ECT) in the United States, we have conducted basic studies and started a Phase I clinical trial. Our in vivo preliminary results indicate that ECT is effective on RIF-1 mouse tumor and rat fibrosarcomas. The effectiveness is dependent on electrode placement and dosage. In the in vitro study ECT clearly demonstrated dose-dependent human oral carcinoma KB cell growth inhibition by colony-forming assay. ECT caused a pH change around the electrodes and DNA synthesis decreased. At 1 coulomb/ml, pH decreased to 4.53 at the anode and increased to 10.46 at the cathode. We have started an animal study to resolve the ECT methodological problems for breast cancer. Meanwhile, we began a clinical trial, entitled "Phase I study of electrochemical treatment of recurrent superficial measurable malignant tumors". Our goal is to make ECT a useful alternative method for treating localized tumors.

To develop cancer electrochemical treatment (ECT) in the United States, we have conducted basic studies and started a Phase I clinical trial. Our in vivo preliminary results indicate that ECT is effective on RIF-I mouse tumor and rat fibrosarcomas. In the in vitro study ECT clearly demonstrated dose-dependent human oral carcinoma KB cell growth inhibition by colony-forming assay. We have started an animal study to resolve the ECT methodological problems for rat breast cancer. Meanwhile, we began a clinical trial treating patients with recurrent superficial measurable malignant tumors. Our goal is to make ECT a useful alternative method for treating localized tumors.

Twenty-five patients with primary squamous cell carcinoma of the oesophagus were treated with intracavitary hyperthermia combined with external beam radiation and intraluminal radiation at Nanjing Jinling Hospital, China. External beam radiation was given with a 6-MV X-ray; 1.8-2.0 Gy per fraction and five fractions per week; this brought the total dose to 60 Gy. Two weeks later, hyperthermia was applied with 915 MHz microwave intracavitary applicators, which were designed at the City of Hope. Temperature measurements were obtained while moving fibreoptic temperature sensors at 1.0 cm intervals in each of the six peripheral channels of the applicator. Hyperthermia was applied for 1 h before and after the intraluminal radiation. Intraluminal radiation was provided by low dose-rate iridium-192 ribbons in the same intracavitary applicator, giving 30 Gy at 0.75 cm from the applicator surface. The 3-month post-treatment responses showing complete response, partial response, no change and progressive disease were 60% (15/25), 24% (6/25), 8% (2/25) and 8% (2/25) respectively. The median follow-up time was 17 months (range 4-29 months). The 1- and 2-year overall survival rates were 72% (18/25) and 32% (8/25) respectively, and disease-free survival rates were 47 and 30% respectively. The median overall survival and disease-free survival periods were 17 and 10 months respectively. Fourteen patients had local recurrence (either at the primary site or in the lymph node) or had local progression, and five developed metastases. The median duration of the onset of local recurrence or of local progression was 9.5 months (range 0-20 months); the median of distant metastases was 8 months (range 2-16 months). Seventeen patients died. Of these, 15 died of cancer: six with local recurrence alone, four with local progression primary cancer alone, three with distant metastases alone, and two with both local and distant failure. Two patients with complete response of the primary disease died of other diseases. The toxicity was mild. According to the mucous reaction scoring criteria of the Radiation Therapy Oncology Group, the acute toxicity grades I, II, III and IV were 0% (0/25), 20% (5/25), 48% (12/25) and 32% (8/25) respectively. The major late complication was a mild oesophagus fibrosis and difficult swallowing. No serious side effects (grade IV), fistulas or perforations were seen. These results indicate that this method is safe and feasible for treating oesophageal carcinoma.

Radio frequency (RF) heating of an implanted spinal fusion stimulator (SpF) during magnetic resonance imaging (MRI) was studied on a full-size human phantom. Heating during MRI scans (GE Signa 4X, 1.5 T) was measured with RF-transparent fiberoptic sensors. With the implant correctly connected, the maximum temperature rises were less than 2 degrees C during the 26 min that the scans were at maximum RF power. At the tip of a broken stimulator lead (connecting the SpF generator and its electrodes), the maximum temperature rise was 11-14 degrees C. Regular 4-min scans of the spinal cord produced similar temperature rises at the broken tip. After the generator and the leads were removed, heating at the electrode connector tip was less than 1.5 degrees C. The control temperature rises at the same locations, without the stimulator, were less than 0.5 degree C. This study shows that spinal fusion stimulator heating is within the Food and Drug Administration safety guideline of 2 degrees C. However, if a lead wire is broken, it is unsafe during MRI scans. Radiological examinations will be necessary to ensure the integrity of the implant.

Electrochemical treatment (ECT) of cancer utilizes direct current to produce chemical changes in tumors. ECT has been suggested as an effective alternative local cancer therapy. However, a methodology is not established, and mechanisms are not well studied. In vivo studies were conducted to evaluate the effectiveness of ECT on animal tumor models. Radiation-induced fibrosarcomas were implanted subcutaneously in 157 female C3H/HeJ mice. Larger rat fibrosarcomas were implanted on 34 female Fisher 344 rats. When the spheroidal tumors reached 10 mm in the mice, two to five platinum electrodes were inserted into the tumors at various spacings and orientations. Ten rats in a pilot group were treated when their ellipsoidal tumors were about 25 mm long; electrode insertion was similar to the later part of the mouse study, i.e., two at the base and two at the center. A second group of 24 rats was treated with six or seven electrodes when their tumors were about 20 mm long; all electrodes were inserted at the tumor base. Of the 24 rats, 12 of these were treated once, 10 were treated twice. and 2 were treated thrice. All treated tumors showed necrosis and regression for both mice and rats; however, later tumor recurrence reduced long-term survival. When multiple treatments were implemented, the best 3 month mouse tumor cure rate was 59.3%, and the best 6 month rat tumor cure rate was 75.0%. These preliminary results indicate that ECT is effective on the radiation-induced fibrosarcoma (RIF-1) mouse tumor and rat fibrosarcoma. The effectiveness is dependent on electrode placement and dosage.

The transient flow conditions within a building drainage system may be simulated by the numerical solution of the defining equations of momentum and continuity, coupled to a knowledge of the boundary conditions representing either appliances discharging to the network or particular network terminations. While the fundamental mathematics has long been available, it is the availability of fast, affordable and accessible computing that has allowed the development of the simulations presented in this paper. A drainage system model for unsteady partially filled pipeflow will be presented in this paper. The model is capable of predicting flow depth and rate, and solid velocity, throughout a complex network. The ability of such models to assist in the decision making and design processes will be shown, particularly in such areas as appliance design and water conservation.