Mt. Pleasant Church, Conewago Township

About two miles south of McSherrystown and a similar distance southwest of Hanover, in Conewago Township, lies the small village of Mt. Pleasant. The community developed at and near the intersection of State Route 194, commonly called the Hanover-Littlestown Pike, and Legislative Route 01005, known in days past as the road from McSherrystown to Gitt\u27s Mill and its segment south of the intersection called in recent times Narrow Drive. In the eastern quadrant of the intersection, a church was built in 1878; nearby and adjacent to the crossroads sat a public school, which had been built sometime before 1858. The school was known by two names, Mt. Pleasant and Schwartz\u27s, and the village itself was also called by some people Schwartz\u27s or Schwartz\u27s Schoolhouse. Further, like the church, the school had religious significance to residents of the vicinity. [excerpt

March into Oblivion: A Footnote

In the above-titled work in 2006, this writer briefly discussed the possibility that President George Washington traversed present Adams County in October 1794, during his return from Bedford to Philadelphia, a belief long and widely held locally. No credible assertion of the President\u27s presence here in 1794 was possible at that time. Recently however, a forgotten narrative was rediscovered ; its author, Jacob Eyster, gives some substance to the previous mere speculation. After extensive research, this writer was graciously requested to produce a sequel to his prior speculative writing. [excerpt

March into Oblivion

The Whiskey Rebellion often is assigned, even by historians, to an obscurity which belies its significance. Its importance was major not only to the people most affected by its cause and those most intimately involved in the playing out of the events, but also to the young federal government, which had to demonstrate its authority yet not trample its own citizens. The situation held a very real potential for tearing apart the fragile nation. President George Washington felt strongly enough about it to involve himself personally in the beginnings of the military action. In the last few years of the century, rapid improvement in economics, safety, and foreign relations, surely spurred in part by the government\u27s reactions to the insurrection, underscored the importance to the nation as a whole. [excerpt

Combustion-wave ignition for rocket engines

The combustion wave ignition concept was experimentally studied in order to verify its suitability for application in baffled sections of a large booster engine combustion chamber. Gaseous oxygen/gaseous methane (GOX/GH4) and gaseous oxygen/gaseous hydrogen (GOX/GH2) propellant combinations were evaluated in a subscale combustion wave ignition system. The system included four element tubes capable of carrying ignition energy simultaneously to four locations, simulating four baffled sections. Also, direct ignition of a simulated Main Combustion Chamber (MCC) was performed. Tests were conducted over a range of mixture ratios and tube geometries. Ignition was consistently attained over a wide range of mixture ratios. And at every ignition, the flame propagated through all four element tubes. For GOX/GH4, the ignition system ignited the MCC flow at mixture ratios from 2 to 10 and for GOX/GH2 the ratios is from 2 to 13. The ignition timing was found to be rapid and uniform. The total ignition delay when using the MCC was under 11 ms, with the tube-to-tube, as well as the run-to-run, variation under 1 ms. Tube geometries were found to have negligible effect on the ignition outcome and timing

Structure of 2,9-dimethyl-1,10-phenanthroline hemihydrate

C14H12N2•½H2O, Mr = 217•27, tetragonal I41/a, a = 14•258 (3), c = 22•286 (4) Å, V = 4531 (3) Å3, Z = 16, Dx = 1•274 (1) g cm-3, Mo Kα radiation λ = 0•71073 Å, µ = 0•74 cm-1, F(000) = 1840, T = 297 K, R = 0•041 for 1196 unique observed reflections with I \u3e 2σ(I). Pairs of dimethylphenanthroline molecules related by a twofold axis are bridged by water molecules lying on the twofold axis and H bonded to one of the N atoms in each molecule. The H bonds are long and far from linear: O—H 1•06 (4), H•••N 154 (3)°. This is presumably a consequence of the approximately parallel arrangement of the two phenanthroline molecules in the (phen)2.H2O complex, which are tilted 4•7 (1)° with respect to each other; the atoms in one molecule are 3•50 to 3•81 Å from the plane of the other molecule. On the other side of the phenanthroline is another phenanthroline related by a center of symmetry with the atoms of one molecule 3•41 to 3•45 Å from the plane of the other molecule. The phenanthroline molecule has close to 2mm symmetry, but the individual C6 rings are tilted about 1° with respect to each other

Acoustic properties of fine‐grained sediments from Emerald Basin: Toward an inversion for physical properties using the Biot–Stoll model

Acoustic data from two long cores, comprising marine clays and silts taken from Emerald Basin off Nova Scotia, are presented. High‐resolution measurements of compressional wavevelocity,attenuation, and power law exponent are made using ultrasonic frequencies between 100 to 1000 kHz. The observed values of the frequency dependence of attenuation suggest that a nonconstant Q mechanism is needed to explain these data, and Biot–Stoll theory is used to model the experimental results. An inversion scheme is used to constrain physical parameters in the Biot–Stoll dispersion relation. The inversion shows that there is a restricted range of permeability and grain size. By assigning reasonable values for grain size in the inversion, the Biot–Stoll model predicts unique values for the permeability and frame bulk modulus that agree well with estimates made by other means

Ohio's Drainage Laws - An Overview

PDF pages: 1

Calculation of acoustic parameters by a filter-correlation method

This paper presents the filter correlation method, a technique for extracting consistent and accurate estimates of attenuation parameters from acoustic waveform data. The method minimizes problems associated with short time windows and multipath secondary arrivals. The method comprises two stages: a causal passband filter stage followed by a cross-correlation step. The results of the filter-correlation estimator are compared to those of the spectral difference approach for short time series with and without a secondary multipath arrival. Preliminary analyses of acoustic data collected on cored marine silts and clays show the attenuation properties of these materials cannot be described by a constant Q mechanism. The filter correlation method refines estimates of frequency-dependent velocity, revealing a small but systematic anisotropy between measurements made parallel and transverse to the sediments\u27 bedding plane. The observed velocity anisotropy can be modeled by assuming layered porosity variations in the cored sediments. No systematic anisotropy in attenuation was observed

Observations of Backscatter from Sand and Gravel Seafloors Between 170-250 kHz

Interpreting observations of frequency-dependence in backscatter from the seafloor offers many challenges, either because multiple frequencies are used for different observations that will later be merged or simply because seafloor scattering models are not well-understood above 100 kHz. Hindering the understanding of these observations is the paucity of reported, calibratedacoustic measurements above 100 kHz. This manuscript seeks to help elucidate the linkages between seafloor properties and frequency-dependent seafloor backscatter by describing observations of backscatter collected from sand, gravel, and bedrock seafloors at frequencies between 170 and 250 kHz and at a grazing angle of 45°. Overall, the frequency dependence appeared weak for all seafloor types, with a slight increase in seafloor scattering strength with increasing frequency for an area with unimodal, very poorly to moderately well sorted, slightly granular to granular medium sand with significant amounts of shell debris and a slight decrease in all other locations