The Effect of Carbon Black on TR Moisture Measurements and Beta Ray Basis Weight Measurements

Computer control of paper industry processes is becoming a very significant segment of the industry. Of major importance is on-line measurement and control of moisture and basis weight in the web, those two parameters affect practically every other sheet characteristics. Accurate closed loop control is essential to keeping the product within customer-demanded specifications. Board mills in particular utilize large quantities of waste paper, with the rate of usage expected to increase from 20.5 percent in 1970 to 26 percent by 1985. The concentration of contaminants will increase at a similar rate. One such contaminant, carbon black, will reduce the effectiveness of on-line IR (infrared) moisture sensors. Carbon black is the most important pigment in printing inks, since it colors virtually all black inks. All materials will absorb or reflect light energy, the amount being a function of the material characteristics and the wavelength of the light beam. Carbon black being a black body is nearly an ideal absorber. When present in a web a paper the carbon black will absorb IR wavelengths used to detect water in the sheet, yielding erroneous moisture content measurements. Experimental results showed that the relationship between carbon black level and the deviation from actual moisture is linear

HgCdTe Avalanche Photodiode Array Detectors with Single Photon Sensitivity and Integrated Detector Cooler Assemblies for Space Lidar Applications

A HgCdTe avalanche photodiode (APD) focal plane array assembly with linear mode photon-counting capability has been developed for space lidar applications. An integrated detector cooler assembly (IDCA) has been built using a miniature Stirling cooler. A microlens array has been included to improve the fill factor. The HgCdTe APD has a spectral response from 0.9- to 4.3-m wavelengths, a photon detection efficiency as high as 70%, and a dark count rate of <250 kHz at 110 K. The mass of the IDCA is 0.8 kg and the total electrical power consumption is about 7 W. The HgCdTe APD arrays have been characterized at NASA Goddard Space Flight Center. A series of environmental tests have been conducted for the IDCAs, including vibration, thermal cycling, and thermal vacuum tests. A description of the device and the test results at NASA are given in this paper

Esophageal Manometry with Provocative Testing in Patients with Noncardiac Angina-Like Chest Pain

In a five year period 238 of 594 esophageal manometric studies performed in the authors’ laboratory were done on patients whose major reason for referral was noncardiac angina-like chest pain. Standard eophageal manometry was performed followed by an acid-antacid perfusion period (Bernstein test) and then subcutaneous bethanechol (80 μg/kg to a maximum of 5 mg) was adminstered. Baseline manometry was normal in 38% of patients and was diagnostic of ‘nutcracker’ esophagus, nonspecific esophageal motility disorder, diffuse esophageal spasm and isolated hypertensive lower esophageal sphincter in 24%, 19%, 16% and 3% of patients, respectively. Ninety-six of 238 patients (40%) experienced reproduction of their presenting angina-like chest pain during acid perfusion. In 80% of these patients there were associated esophageal motor abnormal ilies induced by the acid perfusion. Thirty-six of 212 (17%) experienced pain reproduction following the injection of bethanechol; however, 16 of these had already had their presenting chest pain reproduced during the acid perfusion study. In two-thirds of the patients with pain reproduction following bechanechol there was an associated bethanechol-induced esophageal motility disorder. Overall 49% of patients had their pain reproduced during provocative testing. The acid perfusion test reproduced the pain much more frequently than bethanechol simulation. This study reaffirms the value of esophageal manometry and provocative testing in this group of patients

A pilot investigation into the definition of cultural competence of dental health professionals in a Trinidad context

Abstrac