Watts Of Power Research Articles

Metronaut: A wearable computer with sensing and global communication capabilities

Metronaut is a novel wearable computer which captures information, senses position, provides wide range communications, consumes less than one watt of power, and weighs less than one pound. Metronaut employs a bar code reader for information input and position location, a two-way pager for communications, and an ARM processor for computation. Metronaut's application is schedule negotiation and guidance instructions for a visitor to the CMU campus. The visitor's position is determined from reading bar codes at information signs around campus. Modifications to the schedule are negotiated using the two-way pager for communications with the campus computing infrastructure. Metronaut is alternatively powered by a mechanical flywheel converting kinetic energy to electrical energy.

Commercial plasma source ion implantation facility

Empire Hard Chrome, in cooperation with Los Alamos National Laboratory, has recently installed commercial plasma source ion implantation (PSII) equipment built by North Star Research Corporation. The PSII system consists of a 1 × 1 m cylindrical vacuum chamber with a pulsed RF plasma source which generates plasma densities on the order of 1 × 10 10 cm −3 while drawing only a few hundred watts of power. The high-voltage pulse modulator is capable of delivering pulses with peak voltages of 100 kV and peak currents of 300 A at maximum repetition rate of 400 Hz. The pulse modulator uses a thyratron tube to switch a pulse forming network which is tailored to match the dynamic PSII load. In this paper, we discuss the PSII system and early commercial applications to production tooling.

An assessment of claims of ‘excess heat’ in ‘cold fusion’ calorimetry

Claims of ‘excess heat’ from measurements of the heat of electrolysis at several watts of power are largely based on use of poorly characterized, isoperibol, heat-conduction calorimeters with single-point temperature sensors. This paper describes construction, testing, and calibration of a calorimeter of similar design. Heat-conduction calorimeters with single-point temperature sensing and inadequate mixing are subject to large systematic errors resulting from non-uniform heat distribution within the system. Confirmation of electric-heater calibration by a chemical reaction with a well-known enthalpy change is a minimum requirement to insure accuracy. Improper or incomplete calibration is a probable cause for many claims of ‘excess heat’ in ‘cold fusion’ experiments.

Demand analysis for solar photovoltaic cells—a case study of Gundlupet Taluk

The demand for energy in India has been growing steadily over the years. Since conventional energy options have failed to cope with this increase, there has been growing interest in non-conventional energy sources. Solar photovoltaic (SPV) cells could be one such alternative energy source since solar energy is available abundantly in India. It is also renewable and non-pollutant. In this paper, estimation of demand for SPV cells in a drought-prone area of Karnataka State, Gundlupet, is projected for four identified market segments for the year 1996. Comparison of the cost of generation by SPV with that of conventional hydroelectricity with present and future costs is also made. The demand projections are encouraging for use of SPV cells. The projected cost of SPV energy by AD 2000 for amorphous silicon cells would be Rs 7.01 per kilowatt hour for a module price of Rs 55 per peak watt of power and a distance from the rigid of 3 km.

Magnetic Bearing Design for Reduced Power Consumption

Magnetic bearings have relatively low power consumption compared to fluid film and rolling element bearings. They are now candidates for supporting gas turbines and aeropropulsion engines. This paper describes the design and construction of permanent magnet biased, actively controlled magnetic bearings for a flexible rotor. The rotor was originally supported in fluid film bearings consuming as much as 3000 watts of power. For the magnetic bearing, both permanent magnets and electromagnets are used in a configuration which effectively provides the necessary fluxes in the appropriate air gaps to support the rotor. The theoretical development related to the bearing design is presented along with some experimental performance results. The results include measurements of power consumption, load capacity, bearing linearized coefficients, and the dynamic response of the rotor. The measured total power consumption, excluding shaft losses, was 210 watts in the permanent magnet biased bearing.

705-1 Radio Frequency Lesion Depth vs. Width Maturation: Two Contrasting Parameters

Catheter to tissue contact, RF power level, and RF application time are factors that define the rate of lesion growth and final lesion size. In this investigation of the determinants of lesion width (W) and depth (D), we attempted to define optimal requirements to maximize lesion depth. In 5 dogs LV free wall epicardial lesions were generated with 10, 20, 30, 40, and 50 watts of RF power applied with a temperature-monitoring 4 mm tip ablation electrode. The lesions were created with the catheter tip electrode contacting the tissue at various levels. The catheter tip was pressed 3 mm (+3) and 1 mm (+ 1) into the epicardium or placed lightly over the epicardium (0). The RF application time was varied from 10–120 sec. The heart and electrode were immersed in circulating blood at a constant temperature of 37°C. The width of the lesion matured within 10–20 seconds for the largest lesions [W = 9.3 ± 1.3 mm at 50 watts and +3 contact,*W = 8 ± 0.7 mm with +1 contact, and *#W = 6.3 ± 1 mm with 0 contact (*p < 0.05 vs. +3 contact; #p < 0.05 vs. + 1 contact)]. The overall maximum lesion depth (9.2 ± 1.2 mm) was measured with +3 contact and 20 watts of power applied for 100 sec. With +1 contact, the greatest lesion depth (8.7 ± 2 mm) was the result of 40 sec of 30 watt RF power. At 0 contact, the maximum depth (8 ± 0.7 mm) was obtained with 30 watts applied for 100 seconds. At 40 and 50 watts, 70% of the lesions were terminated by rapid impedance rise 10–30 sec after the intiation of RF application. At all contact and power levels, lesion depth was significantly smaller if the power application was terminated before 40 sec (D = 6.1 ± 1.3 mm, p < 0,05 vs. 60 sec or greater). (1) lesion width matured within the first 20 sec of power application for all power and contact levels. (2) Over 1.5 minutes of power application is required for deeper RF lesions to mature. (3) The use of power levels of 40 or 50 watts often results in an impedance rise before depth maturation. (4) Since contact level is not known prior to power application, the power level should be limited to 20–30 watts or less and applied for 1.5 minutes.

High-power HTS microstrip filters for wireless communication

The performance of narrowband microstrip filters with low insertion loss and high power-handling capabilities made from YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// (YBCO) high-temperature superconducting (HTS) thin films is presented. Results are shown for two different designs that were chosen to optimize the power-handling capability. Both filters have a 2-GHz center frequency and 5 poles that incorporate coupled resonators with 10-/spl Omega/ internal impedances. They were made on 5-cm-diameter LaAlO/sub 3/ substrates. Both designs use parallel-coupled feed lines to avoid current crowding, The first design includes backward- and forward-coupled filters, has 1% bandwidth, and has handled over 25 watts of input power at 10 K with less than 0.25 dB compression. The second design has 1.2% bandwidth and uses only forward-coupled resonators. The dissipation loss is less than 0.2 dB at 45 K and it has a third-order intercept of 62 dBm. Another similar filter handled 36 watts of power at 45 K with less than 0.15 dB compression across the passband. We have developed a technique to visualize the power dissipation of the filter by observing the bubbles created by the filter when submerged in liquid helium, showing areas with local defects or where the current distribution is at its peak value. We also discuss several planar high-power filter issues, including material selection and fabrication, device configuration trade-offs, filter structure optimization, and design approaches to maximize power-handling capacity.

Characteristics of Nd:YAG sculptured contact probes after prolonged laser application.

This study analyzed the functional and structural characteristics of cone, hemisphere, and modified sculptured contact fibers (1,000 microns) after 1 hour of continuous Nd:YAG laser application. Continuous laser application was performed on live porcine tissue using 20 watts of power. The fiber's appearance under a microscope as well as the power output was recorded after 0, 5, 10, 20, 30, 45, and 60 minutes of continuous laser application. (N = 3 for each fiber). At time 0, all fibers transmitted from 49 to 56% of the initial 20 watts (W); power transmission decreased to less than 9% relative power transmission after 20 minutes and then plateaued. The fibers exhibited severe distortion and carbonization of the surface where laser had been applied with evidence of quartz melting and shattering after only 10 minutes. By 30 minutes of laser application, all three fibers were fractured and essentially indistinguishable from one another; moreover, the fibers exhibited similar power transmission, and cutting and coagulation activity, as determined by a panel of independent, double-blinded surgeons. These data lead us to conclude that 1) Nd:YAG contact laser effects result from thermal heating of the fiber tip with subsequent tissue injury, 2) the unique structural configuration of the fiber's sculptured tip are lost after several minutes of laser application without appreciable change in functional integrity, and 3) fibers may be manually fractured allowing for multiple uses without significant sacrifice of power transmission or surgical utility.

High-powered CO2 laser cystoscope for endoscopic bladder surgery.

The CO2 laser is potentially useful for the surgical treatment of superficial bladder tumors. High water absorption of the CO2 laser beam and the lack of a flexible fiber delivery system has hindered development of cystoscopes designed to evaporate bladder tumors. This report describes a cystoscope capable of delivering a high-power CO2 laser beam to all parts of the urinary bladder. A rigid 24 Fr. cystoscope transmitting 80 Watts of power via an articulated arm and infrared waveguide was built. Beam manipulation is by reflection using a movable mirror. Smoke and urine are evacuated by continuous flow of CO2 purge gas. An isotopic laser delivering an 11.1 micron wavelength beam prevents resonant absorption. Conventional 30-70 degrees telescopes are used. Scope performance and lesion morphology were tested in four female pigs. A total of 80-85% of the incident energy is delivered to the mucosa. All areas of the bladder mucosa can be evaporated. All components tolerate wetting. Mucosa and lamina propria are evaporated with 30 Joules of delivered energy. Perforation occurs after 120-160 Joules are delivered to a single spot. The limitations of power, beam transmission, beam manipulation within a small cavity, and resistance to wetting have been overcome.

A design framework for low power analog filter banks

We detail the design of multiresolution analog filter banks, linear models of cochlear function, with power dissipation being a prime engineering constraint. We propose that a reasonable goodness criterion is the information rate through the system, per watt of power dissipated. Speech applications requiring filter banks with a wide frequency tuning range, from 20 Hz to 20 kHz, and low power consumption make the transconductance-C integrator in subthreshold CMOS the preferable integrator structure. As an example, the dynamic range of a lowpass filter is computed and subsequently used to design a filter bank that models faithfully cochlear micro-mechanics. The power consumption of the entire filter bank is computed from analytical expressions and is estimated as 355 nW, at 68 kb/s overall information rate at the output of the system.

Electron Beam Activated Diamond Devices

ABSTRACTDiamond's unique properties are ideally suited for high power and high frequency electronic applications. Natural type Ila diamond wafers of various thicknesses and active areas were used to construct several electron beam activated diamond devices. Average voltage gradients in the diamond target on the order of a mega-volt per centimeter were obtained. Possibilities of improving the attainable average voltage gradient are discussed. Electron activation avoids the necessity of semiconducting doping of the active diamond devices. The electron bombardment on diamonds yields a current-voltage characteristics very similar to that of a bipolar transistor. In the experiments discussed here, the diamond conduction to bombarding current gain ranged from 1,000 to 3,000 depending upon the diamond thickness and the bombarding electron energy. The bombarded diamond on-state resistance is consistent with a simple carrier drift and space charge model. Maximum conduction current density achieved in diamond is 19kA/cm2. High power switching of greater than 25kW with less than 100ns risetime is demonstrated. An electron beam bombarded millimeter wave diamond device has generated more than one watt of power.

Laser-TURP with a lateral firing fiber for contact irradiation

We have operated 25 BPH patients with transurethral Nd-YAG laser ablation for prostate from June of 1993 till December of 1993. We used UltraLine fiber for contact laser irradiation of the prostate. This is a lateral firing quartz fiber with high density laser energy output, and so made it possible for us to vaporize prostatic tissue rapidly and deeply. We used 60 Watts of power for all cases. For the prostates larger than 50 cm3, limited resection after laser ablation allowed early relief of patients' symptoms. Two months after the treatment, average flow rate improved from 3.7 ml/sec to 7.8 ml/sec. Volume of residual urine decreased from 48.4 ml to 17.0 ml. Twenty-four percent decrease of prostatic volume was also recognized with transrectal sonography. Only 4 patients complained of transient urinary retention, although another 3 or 5 days catheter placement relieved their symptoms. Bleeding was negligible and the other postoperative complications were not recognized at all. Laser-TURP is a new treatment that is effective, less morbid and economical, compared with the ordinary TUR-P. So it will soon become an alternative method to electrocautery TUR-P.

Odyssey, an optimized personal communications satellite system

Personal communications places severe demands on service providers and transmission facilities. Customers are not satisfied with the current levels of service and want improvements. Among the characteristics that users seek are: lower service rates, hand held convenience, acceptable time delays, ubiquitous service, high availability, reliability, and high quality. The space industry is developing commercial space systems for providing mobile communications to personal telephones. Provision of land mobile satellite service is fundamentally different from the fixed satellite service provided by geostationary satellites. In fixed service, the earth based antennas can depend on a clear path from user to satellite. Mobile users in a terrestrial environment commonly encounter blockage due to vegetation, terrain or buildings. Consequently, high elevation angles are of premium value. TRW studied the issues and concluded that a Medium Earth Orbit constellation is the best solution for Personal Communications Satellite Service. TRW has developed Odyssey, which uses twelve satellites in medium altitude orbit to provide personal communications satellite service. The Odyssey communications system projects a multibeam antenna pattern to the Earth. The attitude control system orients the satellites to ensure constant coverage of land mass and coastal areas. Pointing can be reprogrammed by ground control to ensure optimized coverage of the desired service areas. The payload architecture features non-processing, “bent pipe” transponders and matrix amplifiers to ensure dynamic power delivery to high demand areas. Circuit capacity is 3000 circuits per satellite. Each satellite weighs 1917 kg (4226 pounds) at launch and the solar arrays provide 3126 Watts of power. Satellites are launched in pairs on Ariane, Atlas, or other vehicles. Each satellite is placed in a circular orbit at an altitude of 10,354 km. There are three orbit planes inclined at 55° to the equatorial plane. Deployment of the satellites permits phased introduction of service. After only three launches, in which two satellites are launched into each plane, continuous service can be provided to most of the world. After three more launches for a total of 12 satellites, service can be expanded to all populated regions of the Earth with path diversity to most regions. The Odyssey system is superior to both geostationary satellites and low earth orbiting satellites. Odyssey provides many benefits to the end user which are described in the paper. These include: low cost, convenience, high availability, reliability, and acceptable time delay. Odyssey exhibits benefits for telecommunications operators: simple operations, incremental, phased startup, long space segment life-time, high profitability, dynamic flexibility for adjustment and short time to market. Since submission of an FCC application in 1991, TRW has continued to explore ways to further improve the Odyssey approach by expanding coverage to the entire world and reducing the initial investment while maintaining high quality service.

婦人科領域における腹腔鏡下レーザー手術

We have performed some procedures of laparoscopic laser surgery with KTP/532 laser. All procedures were observed under video contrail with 3CCD camera.Using 5 to 15 watts of power from KIP/532 laser, a linear incision was made in the ovarian capsule and wall in ovarian chocolate cyst. After evacuation of bloody content, the cyst wall was completely removed. Filmy peritubular and periovarian adhesions were easily vaporized with KTP/532 laser. With more dense, vascular adhesions, the injury of adjacent tissue was minimized by KTP/532 laser system. The ablation of uterosacral ligament was performed on the posterior portion of ligament adjacent to uterine cervix.These all procedures tends to save patients time and discomfort. These complaints of all cases were immediately disappeared about 70-80% after laparoscopic surgery. The laparoscopic laser surgery is more effective and minimum invasive treatment for benign gynecologic disorders.

側射用ファイバーを用いた前立腺レーザー治療

Animal experiment was performed with seven male dogs weighing between 21 and 25 kg, under general anesthesia, with pentobarbital sodium (25mg/kg). A midline lower abdominal incision was made to expose the urinary bladder. 23Fr conventional cystoscope was introduced into the prostatic urethra via cystostomy. The entire operative procedure was observed under TV monitor. Laser irradiation was begun linearly from proximal to the apex of the prostate using Hercules 5060UTM and Model 6000TM Nd: YAG laser (LaserSonics) and UltraLineTM (LaserSonics) fiber which delivered 50 watts of power for 20, 30, 40 and 60 seconds at 3, 9 o'clock. Animals were killed immediately, and at 2, 4, and 6 weeks after the operation. The bladder, prostate and urethra were carefully examined and removed. Specimens were cut into transverse step-section. As the results, thermal coagulation necrosis and delayed sloughing were observed usually several weeks after the procedure. The prostatic urethral cavity was covered with transitional epithelium in the later stage. Clinically 27 male patients underwent laser operation. Their ages ranged from 53 to 80 years of age. The present study selected the patient with below 15 ml/sec in peak flow rate (uroflometry), above 20 gram prostate volume (transrectal ultrasound) and above 15 points in AUA Symptom Score, and excluded the patient with prostatic cancer and neurogenic bladder. The used instrument was the same as those used in the animal experiment. The laser prostatectomy was carried out with standard lithotomy position under spinal anesthesia. The laser was employed at four radial regions (2,4,8 and 10 o'clock positions), additionally to 3,5,7 and 9 o'clock position, with the fiber being dragged from the bladder neck to the verumontanum. The laser was set at 50 watts power on continuous wave. The drag rate was from 30 to 60 seconds. Clinical efficiency was determined by peak flow rate, residual urine, AUA Symptom Score, prostatic volume and side effect. The total evaluation was divided into 3 grades (useful, slightly useful, not useful). According to the criteria, laser surgery was classified as useful in 11 (68.8%). As the side effect, 13 patients revealed urinary retention and one patient showed acute epididymitis after the operation.

Operation of the sapphire Cerenkov laser

First operation of a sapphire-based Cerenkov free electron laser is reported. It is a tunable source of coherent millimeter and submillimeter radiation. The phase velocity of light in sapphire is about one-tenth of that in free space so that Cerenkov radiation is obtained at modest electron beam energies. In addition to its role as a Cerenkov coupler, the sapphire forms a high Q resonator obviating external mirrors. The spontaneous Cerenkov emission is well-confined by this resonator and can build to watts of power. Measured tuning and threshold currents are presented and compared with the predictions of free electron laser theory.

Scenario for cold fusion by free quark catalysis

Fleischmann and Pons have reported the astonishing results of watts of power from cold deuteron fusion without large amounts of radiation. We present a scenario in which small numbers of free stable\(\bar u\bar u = Q\) anti-diquarks (electric charge of −4/3, mass of a few GeV, and short-range strong repulsion with hadrons) catalyze the deuteron fusion. The reaction channel4He+Q dominates. We predict bursts of neutrons with a 3-body energy spectrum. However, independently of the findings of these experiments, the Q catalysis is attractive in that it could provide large power production, with relatively low radioactivity, if this kind of matter is found and accumulated.

Catheter Ablation of Canine Ventricular Myocardium Utilizing Radiofrequency Current

To determine if catheter‐delivered radiofrequency current (RFC) could safely destroy ventricular myocardium, 6P quadripolar catheters were inserted into the right ventricular and left ventricular endocardium of 11 heparinized, closed‐chest dogs. RFC (continuous wave, 625 kHz) was delivered via a commercially available eiectrosurgical unit for 10–20 sec between the catheter tip and a surface electrode (unipolar configuration). Voltage delivered was 42 ± 8 volts with a current of 0.23 ± 0.07 amperes and an impedance of 182 ± 32 ohms. An average power of 9.8 ± 4.4 watts resulted in a delivered energy of 112 ± 60 joules. The catheters were repositioned in the right and left ventricular apices and RFC was delivered between the two tip electrodes for 10–20 sec (bipolar configuration). Voltage delivered was 44 ± 7 watts with a current of 0.20 ± 0.07 amperes and an impedance of 241 ± 49ohms. An averageof 8.5 ± 4.3 watts of power resulted on delivered energy of 106 ± 29 joules.At necropsy, lesions were identified in 5/11 right and 9/11 left ventricular free‐wall sites and 7/11 right and 11/11 left ventricular apical sites. Lesion size ranged from 4–8 mm in depth and 3–9 mm in diameter and the size did not correlate with energy delivered. The endocardial surface was grossly intact in all. No hemodynamic compromise, electrode pitting, or changes in postshock catheter resistance were noted. However, one dog had spontaneous ventricular fibrillation after a transseptal pulse. Although no large thrombi were noted, a thin layer of endocardial thrombus formation was usually present. We conclude that catheter‐delivered RFC can selectively damage myocardial tissue with minimal complications.

Histopathological Appraisal of Carbon-dioxide Laser Dorsal Root Entry Zone (DREZ) Lesions in Primates

Dorsal Root Entry Zone (DREZ) thermocoagulation using radiofrequency has successfully been employed in the treatment of various deafferentation pain syndromes. The ability of surgical lasers to produce discrete lesions with precision has prompted their use in DREZ lesioning. The effects of carbon-dioxide laser induced DREZ lesions in the primate spinal cord were studied in the Bonnet monkey and the parameters necessary to produce a histologically ideal DREZ lesion were evaluated. Lesions were made with 10, 15 and 20 Watts power for pulse durations of 100 to 400 milliseconds at a constant beam spot size of 0.4 mm. It was found that histologically ideal lesions were produced with 20 Watts of power and a pulse duration of 300 milliseconds and with 15 Watts power and 400 millisecond pulse duration. The lesion lengths and widths at different parameters were also comparatively evaluated. The postulated mechanisms of deafferentation pain and the possible mode of action of DREZ lesions in management of pain are also reviewed.

Palliative laser therapy for malignant dysphagia.

Seventy six patients with dysphagia caused by malignant tumours of the oesophagus or gastric cardia have been treated using the Neodymium Yttrium Aluminium Garnet (NdYag) laser. The laser was set to deliver 80-100 watts of power for 0.5-1 second pulses. To obtain improvement, patients on average needed four treatment sessions with a mean energy per treatment of 3586 joules. Follow up endoscopy and laser treatment was at four week intervals, unless the clinical or endoscopic results indicated otherwise. The immediate result was to allow 32% of patients to swallow anything they liked, a further 54% were able to take most solids and 9% were improved, or maintained on liquids only. The mortality of laser recanalisation and associated treatment was 5%. The improvement in swallowing was maintained until death in all but 15% of these patients, some of the 15% needed intubation to allow adequate swallowing. Endoscopic, or surgical intubation was required immediately in five patients after an initial laser course failed to provide improvement. The mean survival of the whole group was 19 weeks (range one to 112 weeks).