Pressure pulsed

There are two types of impulse printers (Eig. 19). A piezoelectric ink jet propels a drop by flexing one or more walls of the firing chamber to decrease rapidly the volume of the firing chamber. This causes a pressure pulse and forces out a drop of ink. The flexing wall is either a piezoelectric crystal or a diaphragm driven by a piezoelectric incorporated into the firing chamber (Eig. 19a). Thermal impulse ink jets also propel one drop at a time, but these use rapid bubble formation to force part of the ink in a firing chamber out the orifice (Eig. 19b). 

Shock Sensitivity Shock-sensitive materials react exothermically when subjected to a pressure pulse. Materials that do not show an exotherm on a DSC or DTA are presumed not to be shock sensitive. Testing methods include ... 

Benjamin, R.F., F.J. Mayer, and R.L. Maynard (1984), Microshell-Tipped Optical Fibers as Sensors of High-Pressure Pulses in Adverse Environments, in Eiber Optics in Adverse Environments 11, Proc. SPIE, 506 (edited by R.A. Green well),... 

L.E. Murr, Effects of Peak Pressure, Pulse Duration, and Repeated Loading on the Residual Structure and Properties of Shock Deformed Metals and Alloys, in Shock Waves and High-Strain-Rate Phenomena in Metals (edited by M.A. Meyers and L.E. Murr), Plenum, New York, 1981, 753 pp. 

The lube oil pumps are now ready to be turned on. The pump and filter bypass valves should be open to avoid pressure pulses in the filter eartridges. Strong pressure pulses may eause filter eartridges to eollapse. Typieal filter elements will withstand 35-100 psi differential. If the pumps are turned on with eaeh bypass elosed, an instantaneous pressure of approximately 150 psi will hit the filters. This is due to the setting of the relief valves. For this reason, it is important to have on hand several extra seal gas and lube oil eartridges. 

The sample eapsule is plaeed in a tight-fitting 4340 steel fixture that serves to support the eopper eapsule. Pressure from the detonation of the explosive is transmitted to the eopper eapsule through a mild steel driver plate. This plate is also lapped optically flat on both surfaces. The mild steel acts to shape the pressure pulse due to the 13 GPa structural phase transition. With proper choice of the diameter of the driver plate and beveled interior opening of the steel fixture, shock deformation of the driver plate acts to seal the capsule within the fixture. 

One of the most interesting results of the zinc ferrite synthesis is the observation that the yield of the product is dependent on the early pressure history. This behavior is shown in Fig. 8.3, which plots the yield versus temperature for baratol explosive loading and for Composition B explosive loading. The difference between these loadings is that the initial pressure pulse amplitude is significantly greater with Composition B. Apparently, the early pressure history has an important conditioning effect for subsequent reactions. 

A slug of water accelerated into the voided pocket. An enormous pressure pulse developed as the slug of water was carried by the steam. 

The pressure pulse blew the 6-in. valve i off its fitting, filling Pit U-3 with steam. 

Results have been presented on one experiment. It involved a 5.659-m vessel containing 1000 kg of butane with a fill ratio of 39%. The vessel s contents were heated to 99°C, which is near but still below the supetheat-limit temperature, producing an internal pressure of 14.6 bar gauge. Vessel failure was then initiated. Measured pressure-time histories indicated that a number of separate pressure pulses occurred. They are plotted in Figure 6.6 as the overpressure-time relationship measured at 25 m from the vessel. 

In Fig. 7.4.1, an idealized representation of tlie blast wave, tlie pressure pulse is shown as a function of tlie distance from tlie explosion center. Tlie sliape of tlie curve at A is not shown tlie cuix es at B tluough D and times 2 tluough 4 show tlie decrease in peak overpressure as tlie w ai e moves outward. Botli posilii e and negatii e pressures are observed in tlie curve at point D and dine 4. Figure 7.4.2 illustrates tlie variadon of overpressure P" widi dine at point D and Ij are die peak overpressure arrivid lime and duration dine, respectively. The modified Friedlander equadon is most conuiionly used to describe die overpressure curve. 

When the circulation is started, the poppet valve travels slowly down, generating one pressure pulse when passing each restriction. The measurement range in the standard tool is of 2.5° (also 7° ranges, 1° increments, max. 17°). 

Assuming the pressure pulse travels with the sound velocity of the mud, how long will it take to reach the rig floor in a 12,000-ft borehole The sound velocity in the mud is given by... 

A pressure pulse is generated at bottom. Compute the pulse velocity in the pipe at bottomhole and at surface, while circulating, assuming a surface temperature of 25°C and a bottomhole temperature of 85°C. The mud compressibility is assumed equal to the water compressibility given in Figure 4-257. Compare to the free mud pressure pulse velocity. 

Since discrete quantities are trapped and transferred, the delivery pressure and flow varies, as shown in Figure 32.21, which also illustrates how increasing the number of cylinders in a reciprocating pump reduces fluctuations. In the case of lobe and gear pumps the fluctuations are minimized by speed of rotation and increasing tooth number, but where, for control or process reasons, the ripple in pressure is still excessive, means of damping pulsations has to be fitted. Often a damper to cope with this and pressure pulses due to valve closure is fitted, and two types are shown in Figure 32.22. 

The output of a primer includes hot gases, hot particles, a pressure pulse (which, in some cases, may be a strong shock), and thermal radiation (Refs 6, 12 13). Some of the aspects of primer output which have been measured as a means of characterization include the following (a) vol of gas emitted (b) the impulse imparted to a column of Hg by the pressure pulse ... 

Some of the brisant primers emit pressure pulses of sufficient magnitude to give measurable results in either the sand test or the Pb-disc test. Although many of these quantities are related to some aspects of primer performance, insofar as output is concerned, no general quantitative relationship of overall value has been-developed which can be used as a means of acceptance... 

It is especially important for the nurse to assess the type, location, and intensity of pain before administering the narcotic analgesic. Immediately before preparing a narcotic analgesic for administration, the nurse assesses the patient s blood pressure, pulse, and respiratory rate. 

The nurse obtains the blood pressure, pulse, and respiratory rate 20 to 30 minutes after the drug is administered intramuscularly or subcutaneously, 30 or more minutes if the drug is given orally, and in 5 to 10 minutes if the drug is given intravenously (IV). 

Before the administration of naloxone, the nurse obtains the blood pressure, pulse, and respiratory rate and reviews the record for the drug suspected of causing the overdosage. If there is sufficient time, the nurse also should review the initial health history, allergy history, and current treatment modalities. 

As part of the ongoing assessment during the administration of naloxone, the nurse monitors the blood pressure, pulse, and respiratory rate at frequent intervals, usually every 5 minutes, until the patient responds. After the patient has shown response to the drug, the nurse monitors vital signs every 5 to 15 minutes. The nurse should notify tlie primary healdi care provider if any adverse drug reactions occur because additional medical treatment may be needed. The nurse monitors die respiratory rate, rhydun, and depdi pulse blood pressure and level of consciousness until the effects of die narcotics wear off. 

When a patient is to receive an adrenergic agent for shock, the nurse obtains the blood pressure, pulse rate and quality, and respiratory rate and rhythm. The nurse assesses the patient s symptoms, problems, or needs before administering the drug and records any subjective or objective data on the patient s chart. In emergencies, the nurse must make assessments quickly and accurately. This information provides an important database that is used during treatment. 

ANALEPTICS. When a CNS stimulant is prescribed for respiratory depression, initial patient assessments will include the blood pressure, pulse, and respiratory rate. It is important to note the depth of the respirations and any pattern to the respiratory rate, such as shallow respirations or alternating deep and shallow respirations. The nurse reviews recent laboratory tests (if any), such as arterial blood gas studies. Before administering the drug, the nurse ensures that the patient has a patent airway. Oxygen is usually administered before, during, and after drug administration. 

ANOREXIANTS When an anorexiant or amphetamine is used as part of the treatment of obesity, the drug is usually prescribed for outpatient use The nurse obtains and records the blood pressure, pulse, respiratory rate, and weight before therapy is started. 

If vomiting is severe the nurse observes the patient for signs and symptoms of electrolyte imbalance. The nurse monitors the blood pressure, pulse, and respiratory rate every 2 to 4 hours or as ordered by the primary health care provider. The nurse carefully measures the intake and output (urine, emesis) until vomiting ceases and the patient is able to take oral fluids in sufficient quantity. The nurse documents in the patient s chart each time the patient has an emesis. The nurse notifies the primary health care provider if there is blood in the emesis or if vomiting suddenly becomes more severe... 

Checking blood pressure, pulse, intravenous lines, cadieters, drainage tubes, surgical dressings, and casts. 

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