Farm management surveys in Black Hawk, Grundy and Tama counties, Iowa

The average labor income of 965 farmers in Black Hawk, Grundy and Tama counties in 1913 was $306 and the return on investment 4.1 percent. In the same area the average labor income of 210 farmers in 1918 was$1,382 and the return on investment 6.3 percent. War prices for farm products were the cause for the larger labor incomes the latter year. Thirty-five percent of the farmers in 1913 and 19.2 percent in 1918 had minus labor incomes; 4.3 percent of the farmers in 1913 and 33.6 percent in 1918 had labor incomes of $2,000 and over

The cost of production milk

A study of milk production costs on 58 farms near Mason City, Cerro Gordo county, Iowa, covering the year November 1, 1916, to November 1, 1917, shows that the net cost of the 4,108,036 pounds of milk produced by the 900 cows on these farms was $3.15 per 100 pounds under the conditions for that year. All charges that could properly be made against the milk were included and all credits were also considered. On some farms the cost of production was less, as low as$1.80 per 100 pounds, and on some it was much higher, as high as $5.60 per 100 pounds. Feed and bedding costs, at the prices prevailing in Cerro Gordo county in the period covered, amounted to$2.15 per 100 pounds of milk, while man and horse labor costs totaled 76 cents per 100 pounds. The cost for equipment, buildings, cows, bull service and other items made a total of 60 cents per 100 pounds. The credit for calves and manure was found to be 36 cents per 100 pounds of milk produced

Improving Speech Communication in High Noise Environments

During speech the vocal folds vibrate resulting in audible sounds that are transmitted through the vocal tract as well as vibrations that are transmitted through the body tissue to the skin surface. These skin surface vibrations can be detected by contact microphones and used to transmit speech. However, the skin attenuates high frequency content and in some locations muffles the signal resulting in poor speech quality. To reconstruct a signal that better matches the microphone signal a finite impulse response filter is fit to an average transfer function of the accelerometer signal. When implemented this filter restores much of the lost frequency content and in the presence of background noise results in a signal with good intelligibility and less noise than the microphone signal

Frequency Response of the Neck During Production of Selected Speech Sounds

During speech the vocal folds vibrate resulting in audible sounds that are transmitted through the vocal tract as well as vibrations that are transmitted through the body tissue to the skin surface. These skin surface vibrations can be detected by contact microphones and used to transmit speech. The objective of this study was to characterize the frequency content of speech signals at a concentrated are on the neck. Signals were recorded using accelerometers attached to 12 locations on the neck of seven subjects as well as a microphone to record audible speech. The subjects produced several isolated phonemes. The power spectral densities (PSDs) of the phonemes were used to determine a quality ranking for each location and sound

The Effect of Valve Cooling upon Maximum Permissible Engine Output as Limited by Knock

A Wright GR-1820-G200 cylinder was tested over a wide range of fuel-air ratios at maximum permissible power output as limited by knock with three different degrees of valve cooling. The valves used were stock valves (solid inlet valve and hollow sodium-cooled exhaust valve), hollow valves with no coolant, and hollow valves with flowing water as a coolant. Curves showing the variation in maximum permissible values of inlet-air pressure, indicated mean effective pressure, cylinder charge, and indicated specific fuel consumption with change in fuel-air ratio and valve cooling are shown. The use of valves cooled by a stream of water passing through their hollow interiors permitted indicated mean effective pressures 10 percent higher than the mean effective pressures permissible with stock valves when the engine was operated with fuel-air ratios from 0.055 to 0.065. Operation of the engine with lean mixtures with uncooled hollow valves resulted in power output below the output obtained with the stock valves. The data show an increase in maximum permissible indicated mean effective pressure due to cooling the valves, which averages only 2.1 percent with fuel-air ratios from 0.075 to 0.105

Formaldehyde, glyoxal, and methylglyoxal in air and cloudwater at a rural mountain site in central Virginia

As part of the Shenandoah Cloud and Photochemistry Experiment (SCAPE), we measured formaldehyde (HCHO), glyoxal (CHOCHO), and methylglyoxal (CH3C(O)CHO) concentrations in air and cloudwater at Pinnacles (elevation 1037 m) in Shenandoah National Park during September 1990. Mean gas‐phase concentrations of HCHO and CHOCHO were 980 and 44 pptv, respectively. The concentration of CH3C(O)CHO rarely exceeded the detection limit of 50 pptv. Mean cloudwater concentrations of HCHO and CHOCHO were 9 and 2 μM, respectively; the mean CH3C(O)CHO concentration was below its detection limit of 0.3 μM. The maximum carbonyl concentrations were observed during stagnation events with high O3, peroxides, and CO. Outside of these events the carbonyls did not correlate significantly with O3, CO, or NOy. Carbonyl concentrations and concentration ratios were consistent with a major source for the carbonyls from isoprene oxidation. Oxidation of CH4 supplies a significant background of HCHO. The carbonyl concentrations were indistinguishable in two size fractions of cloudwater having a cut at d=18 μm. Gas‐ and aqueous‐phase concentrations of HCHO from samples collected during a nighttime cloud event agree with thermodynamic equilibria within a factor of 2. Samples collected during a daytime cloud event show HCHO supersaturation by up to a factor of 4. Positive artifacts in the cloudwater samples due to hydrolysis of hydroxymethylhydroperoxide (HOCH2OOH) could perhaps account for this discrepancy

An Improved Multipyranometer Array for the Measurement of Direct and Diffuse Solar Radiation

This paper describes an improved multipyranometer array (MPA) for the continuous remote measurement of direct and diffuse solar radiation. The MPA described in this paper is an improvement over previously published MPA studies due to the incorporation of an artificial horizon that prevents reflected ground radiation from striking the tilted sensors. In this paper a description of the NIST-traceable calibration facility is provided and preliminary results are presented that compare the MPA predicted beam to beam measurements from a precision normal incidence pyrheliometer and diffuse measurements from a precision shadow-band pyranometer respectively

Integrin αVβ6-mediated activation of latent TGF-β requires the latent TGF-β binding protein-1

Transforming growth factor-βs (TGF-β) are secreted as inactive complexes containing the TGF-β, the TGF-β propeptide, also called the latency-associated protein (LAP), and the latent TGF-β binding protein (LTBP). Extracellular activation of this complex is a critical but incompletely understood step in TGF-β regulation. We have investigated the role of LTBP in modulating TGF-β generation by the integrin αVβ6. We show that even though αvβ6 recognizes an RGD on LAP, LTBP-1 is required for αVβ6-mediated latent TGF-β activation. The domains of LTBP-1 necessary for activation include the TGF-β propeptide-binding domain and a basic amino acid sequence (hinge domain) with ECM targeting properties. Our results demonstrate an LTBP-1 isoform-specific function in αVβ6-mediated latent TGF-β activation; LTBP-3 is unable to substitute for LTBP-1 in this assay. The results reveal a functional role for LTBP-1 in latent TGF-β activation and suggest that activation of specific latent complexes is regulated by distinct mechanisms that may be determined by the LTBP isoform and its potential interaction with the matrix

Development of Simplified Calculations for a Multipyranometer Array for the Measurement of Direct and Diffuse Solar Radiation

This paper describes the development of simplified procedures for a multipyranometer array (MPA) for the continuous measurement of direct and diffuse solar radiation. The MPA described in this paper is an improvement over previously published MPA studies due several new features, including: the incorporation of an artificial horizon that prevents reflected ground radiation from striking the tilted sensors, and a routine that corrects the spectral response of photovoltaic-type sensors used in the MPA. An optimal solution procedure has also been developed that eliminates invalid data which are inherent in the simultaneous solution of the solar equations from the four MPA sensors. In this paper a description of the NIST-traceable calibration facility is provided and results are presented that compare the improved MPA-predicted beam to side-by-side measurements from a precision Normal Incidence Pyrheliometer (NIP)

Intercomparison of field measurements of nitrous acid (HONO) during the SHARP campaign

Because of the importance of HONO as a radical reservoir, consistent and accurate measurements of its concentration are needed. As part of SHARP (Study of Houston Atmospheric Radical Precursors), time series of HONO were obtained by six different measurement techniques on the roof of the Moody Tower at the University of Houston. Techniques used were long path differential optical absorption spectroscopy (DOAS), stripping coil-visible absorption photometry (SC-AP), long path absorption photometry (LOPAP® ), mist chamber/ion chromatography (MC-IC), quantum cascade-tunable infrared laser differential absorption spectroscopy (QC-TILDAS), and ion drift-chemical ionization mass spectrometry (ID-CIMS). Various combinations of techniques were in operation from 15 April through 31 May 2009. All instruments recorded a similar diurnal pattern of HONO concentrations with higher median and mean values during the night than during the day. Highest values were observed in the final 2 weeks of the campaign. Inlets for the MC-IC, SC-AP, and QC-TILDAS were collocated and agreed most closely with each other based on several measures. Largest differences between pairs of measurements were evident during the day for concentrations ~100 parts per trillion (ppt). Above ~ 200 ppt, concentrations from the SC-AP, MC-IC, and QC-TILDAS converged to within about 20%, with slightly larger discrepancies when DOAS was considered. During the first 2 weeks, HONO measured by ID-CIMS agreed with these techniques, but ID-CIMS reported higher values during the afternoon and evening of the final 4 weeks, possibly from interference from unknown sources. A number of factors, including building related sources, likely affected measured concentrations