Oblique impact: Projectile richochet, concomitant ejecta and momentum transfer

Experimental studies of oblique impact indicate that projectile richochet occurs for trajectory angles less than 30 deg and that the richocheted projectile, accompanied by some target material, are ejected at velocities that are a large fraction of the impact velocity. Because the probability of occurrence of oblique impact less than 30 deg on a planetary body is about one out of every four impact events, oblique impacts would seem to be a potential mechanism to provide a source of meteorites from even the largest atmosphere-free planetary bodies. Because the amount of richocheted target material cannot be determined from previous results, additional experiments in the Ames Vertical Gun laboratory were undertaken toward that purpose using pendulums; one to measure momentum of the richocheted projectile and concomitant target ejecta, and a second to measure the momentum transferred from projectile to target. These experiments are briefly discussed

Experimental evidence for non-proportional growth of large craters

Evidence from laboratory impact experiments is indicating that increasing crater aspect ratios (diameter:depth) can result from increasing both velocity and projectile size without invoking unusual impactor conditions. An extensive data base of experimental impact cratering was analyzed for a variety of impactors and impact velocities for low strength targets. These data indicate a change in cratering efficiency that appears to be related to the onset of projectile deformation or rupture. When all projectile types and sizes are considered, one finds two contrasting relationships between crater aspect ratio and impactor parameter. These relationships are briefly considered

Momentum transfer from oblique impacts

A completely satisfactory experiment would be in a low gravity environment where the effect of momentum imparted by ejecta impacting the surface can be removed or controlled from momentum transfer during impact. Preliminary estimates can be made using a ballistic pendulum. Such experiments were initiated at the NASA-Ames Vertical Gun Range in order to examine momentum transfer due to impact vaporization for oblique impacts. The preliminary results indicate that momentum from oblique impacts is very inefficient: decreasing with increasing impact velocity and perhaps size; increasing with decreasing density; and increasing with increasing impact angle. At face value, such results minimize the effect of momentum transfer by grazing impact; the more probable impact angles of 30 deg would have a greater effect, contrary to the commonly held impression

Chemical characteristics of air from differing source regions during the Pacific Exploratory Mission‐Tropics A (PEM‐Tropics A)

Ten‐day backward trajectories are used to determine the origins of air parcels arriving at airborne DC‐8 chemical measurement sites during NASA\u27s Pacific Exploratory Mission‐Tropics A (PEM‐T) that was conducted during August‐October 1996. Those sites at which the air had a common geographical origin and transport history are grouped together, and statistical measures of chemical characteristics are computed. Temporal changes in potential temperature are used to determine whether trajectories experience a significant convective influence during the 10‐day period. Those trajectories that do not experience a significant convective influence are divided into four geographical categories depending on their origins and paths. Air parcels originating over Africa and South America are characterized by enhanced mixing ratios of O3, CO, HNO3, and PAN. The backward trajectories travel at high altitudes (∼10–11 km), covering long distances due to strong upper‐tropospheric westerly winds. The observed enhancement of combustion‐related species is attributed to biomass burning from distant sources to the west, extending even to South America. The relatively large value of Be‐7 probably is due either to less efficient removal of aerosols from upper tropospheric air or to small stratospheric contributions. Aged marine parcels are found to have relatively small concentrations of burning‐related species. Although these trajectories arrive at a wide range of aircraft altitudes, they do not pass over a land mass during the preceding 10‐day period. Air passing over Australia but no other land mass exhibits a combustion signature; however, photochemical product species such as O3 and PAN are less enhanced than in the long‐range transport category. These trajectories travel shorter distances and are at lower altitudes (∼5–8 km) than those reaching Africa and/or South America. The combustion influence on these parcels is attributed to biomass burning emissions injected over Australia. That burning is less widespread than in Africa and South America. Finally, trajectories originating over Southeast Asia appear to receive a weak combustion influence. However, compared to Africa and South America, Southeast Asia has a relatively small incidence of biomass burning. There is little combustion input from Australia due to the high transport altitudes compared to the lower heights of the convection. The Southeast Asian parcels exhibit the greatest NOx to ∑NOi ratio of any category, perhaps due to lightning. Parcels experiencing a significant convective influence also are examined. Most of these parcels pass through widespread, persistent convection along either the South Pacific Convergence Zone or Intertropical Convergence Zone approximately 5 days prior to arriving at the aircraft locations. Thus the category mostly represents marine convection. Mixing ratios of peroxides and acids in the convective category are found to be smaller than in parcels not experiencing convection. Small mixing ratios of Be‐7 and Pb‐210 suggest particle removal by precipitation

Ursinus College Alumni Journal, July 1960

President\u27s page • Dr. Paisley completes fifty years as President of the Board of Directors • Dr. McClure salutes Dr. Paisley • Senator Hugh Scott speaks at commencement • Horton preaches Baccalaureate sermon • Mrs. Omwake honored • 1960 Loyalty Fund • Dr. Boswell retires • Four professors given Bear Awards • Memorial minute • Faculty notes • A student reviews the past year at Ursinus • Alumni Day • Alumni elections • Thompson receives award • Admissions\u27 problems • Ursinus experiments in Swedish • Commencement Day • Colonel Campbell, \u2760 • The generous American • 1960 Loyalty Fund breaks all records • Lost alumni • The alumnus / alumna • A defense for the Alumni Association • Edward L. French, \u2738 • Paul E. Elicker, \u2714 • Warren K. Hess, \u2731 • Ursinus sends Morgan to NCAA track trials • Best track season in Ursinus history • Baseball review • Varsity Club news • Ursinus faces rebuilding job • Girls\u27 spring sports • Calling all grumblers • News about ourselves • Necrology • Weddings • Births • Ursinus captain\u27s chairhttps://digitalcommons.ursinus.edu/alumnijournal/1065/thumbnail.jp

Ursinus College Alumni Journal, August 1962

The President writes • Have gun will travel • The Loyalty Fund committee • Ursinus launches campaign for five million dollars • Alumni must think big • Samuel Bond, Ursinus\u27 architect • Faculty notes • 1962 commencement • Distinguished Teaching • Alumni in the news • \u2762 Loyalty Fund nets $52,942.84 • Results of the 1962 Loyalty Fund campaign • Contributors to the 1962 Loyalty Fund • Best track season in Ursinus history • Baseball • Women\u27s sports • Class notes • Weddings • Births • Necrology • Dr. Eugene H. Miller, \u2733, to speak at Forum • New UCC Church conference • The college sealhttps://digitalcommons.ursinus.edu/alumnijournal/1073/thumbnail.jp

Ursinus College Alumni Journal, March 1963

The President writes • Dr. McClure\u27s charge to graduating classes • Norman Egbert McClure: A tribute • Faculty memorial minute • Alumni memorial minute • Twenty-five years of the Messiah at Ursinus • As I recall • A gift for the First Lady • Philip L. Corson • Gypsy: Hail and farewell • Controversy at midnight • Two students leave for Peace Corps • Capital funds subscription total $467,392 to date • Capital funds • McClure and Bone memorials • The Century Club • Dining hall news • Mid-year report of 1963 Loyalty Fund campaign • The third alumni seminar • Clawson to be honored • Reimert recognized • Paisley elected college treasurer • Travel seminar • Navy V-12 reunion planned • Church headquarters at Ursinus • You and the future of Ursinus • College costs • Alumni album • Franklin Earnest III, \u2739 • Walter F. Longacre, \u2714 • Lyndell R. Reber, \u2736 • Archer P. Crosley, \u2742 • Robert S. Litwak, \u2745 • Michael R. Deitz, \u2754 • Allan Lake Rice • Dean concludes career • Wrestling • Dryfoos the greatest • Nominees for Alumni Association offices • Class notes • Weddings • Births • Necrology • Regionalshttps://digitalcommons.ursinus.edu/alumnijournal/1076/thumbnail.jp

Ursinus College Alumni Journal, March 1965

Contributors • From the President • Chemathphy: The integrated science course • The changing face of history • Kirkridge • Candidates • Bargains in life income contracts and annuities with Ursinus College • Mid-year report of 1965 Loyalty Fund campaign • Alumni are nearing capital funds goal • Seeds of hope in Latin America • Campus clippings: Financial support; Soph at age 49; Women\u27s Club; On the air; TW3 was there; Devotions booklet; On treasurer\u27s staff; New reserve book room; The international tone; Bus link; ACLU board member; Farewell & welcome • Track prospects for 1965 • Indoor track • Cross country • Soccer success • New coaches • Wrestling • Alumnae hockey stars • Undefeated in hockey • Football finale • Husband and wife lead small-town church to union • Advertising executive sets fast pace in Baltimore • Class notebook • Weddings • Births • In memoriam • Regionals • At your service • End quotes: The alumnus as patron of learninghttps://digitalcommons.ursinus.edu/alumnijournal/1082/thumbnail.jp

Ursinus College Alumni Journal, November 1964

President\u27s letter • Charles David Mattern, 1907-1964: With tributes from some of his colleagues • Professor without portfolio: A portrait of the Rev. John Henry Augustus Bomberger, D. D., founder and first president of Ursinus College and School of Theology • The contemporary French literary scene • Quarter-century change . . . decade planning • Student facilities building construction moves steadily toward completion by mid-\u2765 • Joseph Chapline, \u2742, former computer expert builds organs - tells how and why • Larry Koch, \u2762, advances with Western Electric • Schellhase saga • Insurance executive, author - historian, two new members of Ursinus Board • The 1964 European travel seminar • Yale Press to publish Dr. Foster\u27s volumes • Four Ursinus alumni attend campus conference for furloughed missionaries • Pancoast, \u2737 elected to Pennsylvania House of Representatives • Collegeville comes to life as Ursinus students return • Founders Day focus on distinguished alumni • Remarks presenting portrait of President of Ursinus Board • Gutenberg Bible reproductions presented by Henry Pfeiffer, \u2748 • Loyalty Fund report: October 10, 1964 • Sports victories, crowning of Queen Jeanne, feature 1964 Homecoming Day at Ursinus • Twenty-three bear cubs in Ursinus freshman class • Frederick Wentz named college business manager • Another John H. A. Bomberger • Alumni news and notes • Weddings • Births • Necrology • Former Dean dead at 83 • Vice-president of directors dies unexpectedly November 1 • Former board member dies • Ursinus Women\u27s Club luncheon December 5 • Chef Colameco hurt in railroad wreck • You need a will . . . and Ursinus needs to be rememberedhttps://digitalcommons.ursinus.edu/alumnijournal/1081/thumbnail.jp