RJ Note: Still gotta wonder-- why?
A device born from the need to test soil moisture around peanut plants is now being used to help test the soil on Mars.
“We designed the device to measure the water content around peanut pods,” said Williams, an agronomist with the University of Georgia College of Agricultural and Environmental Sciences. “At the time, there was no way to measure without disturbing the soil and destroying the pod.”
The year was 1987 and Williams was on sabbatical working with a Washington State University research team led by Gaylon Campbell. The Phoenix Mars Mission landed on the Red Planet May 25. In its tool kit is an advanced version of Williams’ moisture probe.
“We were working on thermal property sensors then to measure heat capacity of soil,” said Campbell, now retired from WSU. “Before, people used a sensor with a single needle having a heater and temperature sensor inside, and measuring the change in temperature over time. We made a dual needle device with a heater in one needle and a temperature sensor in the other.”
Building on the concept
The device worked for Williams’ peanut research. The research team published their findings.
Campbell continued to improve the device. It and other similar models are now developed and sold by Campbell’s company, Decagon, which manufactures measurement devices used by the food and pharmaceutical industries and for agricultural research.
During the American Geophysical Union Meeting in 2004, the sensor device attracted the attention of a scientist working with NASA.
“A scientist from the Jet Propulsion Laboratory (at the California Institute of Technology) stopped by our exhibit and said ‘That’s exactly what I need to send on the Mars lander,’” Campbell said.
And that is where the device is today.
Testing icy soil on Mars
Phoenix’s mission is to study the history of the water now frozen into the Mars permafrost and to check for carbon-containing chemicals that are essential ingredients for life. For the first time, it will also monitor weather at the plant’s polar region from a surface perspective.
NASA’s version of the moisture probe is called the Thermal and Electrical Conductivity Probe. It will test how heat and electricity move through the soil. Ice in the soil can make a big difference in how well the soil conducts heat. The probe is a humidity sensor, too, when held in the air.
Phoenix is a lander, not a rover.
“When it lands it plops down in one spot and a little scoop or shovel on the end of a robot arm will take a sample from the soil on Mars,” Campbell said. “Our sensor is mounted on the scoop and the robot arm pokes it into soil for a measurement.”
So why do we need to know how much moisture is in Mars’ soil?
“They expect to find a lot of water in the polar region of Mars, but it’s believed to be in the form of ice,” he said. “When the robot arm scoops away a thin layer of dust, there should be icy soil below. The sensor will make measurements that confirm that it’s icy soil.”
Scientists on the Mars mission believe the planet used to be covered with water and are determined to find out where the water went.
By Sharon Omahen
University of Georgia
Thursday, May 29, 2008
RJ Note: Still gotta wonder-- why?
Thursday, May 22, 2008
Wednesday, May 21, 2008
The nation's Hispanic population increased 1.4 million to reach 45.5 million on July 1, 2007, or 15.1 percent of the estimated total U.S. population of 301.6 million.
National and state estimates by race, Hispanic origin, sex and age released today by the U.S. Census Bureau also show that the Hispanic population exceeded 500,000 in 16 states.
Hispanics remained the largest minority group, with blacks (single race or multiracial) second at 40.7 million in 2007. The black population exceeded 500,000 in 20 states. Blacks were the largest minority group in 24 states, compared with 20 states in which Hispanics were the largest minority group.
Blacks were followed by Asians, who totaled 15.2 million; American Indians and Alaska Natives, who totaled 4.5 million; and Native Hawaiians and Other Pacific Islanders, with 1 million. The population of whites (single race and not of Hispanic origin) totaled 199.1 million (See Table
With a 3.3 percent increase between July 1, 2006, and July 1, 2007, Hispanics were the fastest-growing minority group. Asians were the second fastest-growing minority group, with a 2.9 percent population increase during the period. The white population grew by 0.3 percent during the one-year period.
Overall, the nation's minority population reached 102.5 million in 2007 -- 34 percent of the total. California had a minority population of 20.9 million -- 20 percent of the nation’s total, Texas had a minority population of 12.5 million -- 12 percent of the U.S. total.
Four states and the District of Columbia were "majority-minority" (i.e., more than 50 percent of their population is made up of people other than single-race non-Hispanic whites). Hawaii led the nation with a population that was 75 percent minority in 2007, followed by the District
of Columbia (68 percent), New Mexico (58 percent), California (57 percent) and Texas
(52 percent). Next in line, though not majority-minority, were Nevada, Maryland and Georgia, each with a minority population of 42 percent (SeeTable 2).
Highlights for the various groups:
-- California (13.2 million) had the largest Hispanic population of any state as of July 1, 2007, followed by Texas (8.6 million) and Florida (3.8 million). Texas had the largest numerical increase between 2006 and 2007 (308,000), followed by California (268,000) and Florida (131,000). In New Mexico, Hispanics comprised the highest proportion of the total population (44 percent), with California and Texas (36 percent each) next in line.
-- The Hispanic population in 2007 had a median age of 27.6, compared with the population as a whole at 36.6. Almost 34 percent of the Hispanic population was younger than 18, compared with 25 percent of the total population.
-- The black population increased by 1.3 percent, or 540,000, between 2006 and 2007.
-- New York had the largest black population in 2007 (3.5 million), followed by Florida and Texas (3 million each). Georgia had the largest numerical increase between 2006 and 2007 (84,000), with Texas (62,000) and Florida (48,000) next. In the District of Columbia, the black
population comprised the highest percentage (56 percent); Mississippi (38 percent) and Louisiana (32 percent) were next.
-- The single-race black population in 2007 had a median age of 31.1, compared with the population as a whole at 36.6. About 31 percent of the black population was younger than 18, compared with 25 percent of the total population.
-- The Asian population rose by 2.9 percent, or 434,000, between 2006 and 2007.
-- California (5 million) had the largest Asian population on July 1, 2007, as well as the largest numerical increase during the 2006 to 2007 period (106,000). New York (1.4 million) and Texas (915,000) followed in population. Texas (44,000) and New York (33,000) followed in numerical increase. In Hawaii, Asians made up the highest proportion
of the total population (55 percent), with California (14 percent), and New Jersey and Washington (8 percent each) next.
-- The single-race Asian population in 2007 had a median age of 35.4, compared with the population as a whole at 36.6.
-- Asians were the largest minority group in Hawaii and Vermont.
American Indians and Alaska Natives
-- The American Indian and Alaska Native population rose by 1 percent or 45,000, from
2006 to 2007.
-- California (689,000) had the largest population of American Indians and Alaska Natives on July 1, 2007, with Oklahoma (394,000) and Arizona (335,000) next. Texas had the largest numerical increase (8,300) since July 1, 2006, followed by Arizona (4,900) and Florida
(2,800). In Alaska, American Indians and Alaska Natives made up the highest
proportion of the total population (18 percent), with Oklahoma (11 percent) and New Mexico (10 percent) next.
-- The single-race American Indian and Alaska Native population in 2007 had a median age of 30.3, compared with the population as a whole at 36.6. About 27 percent of the American Indian and Alaska Native population was younger than 18, compared with 25 percent of
the total population.
-- American Indians and Alaska Natives were the largest minority group in Alaska, Montana, North Dakota, Oklahoma and South Dakota.
Native Hawaiians and Other Pacific Islanders
-- The Native Hawaiian and Other Pacific Islander population rose by 1.6 percent, or 16,000, from 2006 to 2007.
-- Hawaii had the largest population (269,000), followed by California (262,000) and Washington (50,000). California had the largest numerical increase (2,900) of people of this group, with Texas (2,500) and Florida (1,100) next. In Hawaii, Native Hawaiians and
Other Pacific Islanders comprised the largest proportion (21 percent) of the total population, followed by Utah (1 percent) and Alaska (0.9 percent).
-- The single-race Native Hawaiian and Other Pacific Islander population in 2007 had a median age of 30.2, compared with the population as a whole at 36.6. About 29 percent of the Native Hawaiian and Other Pacific Islander population was younger than 18, compared with
25 percent of the total population.
-- The non-Hispanic, single-race white population of 199.1 million represented 66 percent of the total population.
-- California, New York and Texas had the largest population of this group (15.6 million, 11.6 million and 11.4 million, respectively), but Texas experienced the largest numerical increase (95,000), followed by North Carolina (92,000) and Georgia (57,000). Maine (96 percent) had the highest proportion of whites, followed by Vermont (95 percent) and West Virginia (94 percent).
-- The white population in 2007 was older than the population as a whole: The respective median ages were 40.8 and 36.6. About 21 percent of the population of this group was younger than 18, compared with 25 percent of the total population.
Also released today were tabulations by age:
-- Thirteen percent of the total population, 37.9 million people, was 65 and older in 2007.
-- The number of people 85 and older reached 5.5 million, or 2 percent of the population.
-- In 2007, working-age adults (18 to 64) totaled 189.8 million, which was 63 percent of the population.
-- The number of preschoolers (younger than 5) was estimated at 20.7 million.
-- The number of children 5 to 13 was 36 million, with children 14 to 17 numbering 17.2 million.
-- States with the highest percentages of older people (65 and older) included Florida (17 percent), West Virginia (15.5 percent) and Pennsylvania (15.2 percent). States with the lowest percentages were Alaska (7 percent), Utah (8.8 percent) and Georgia (9.9 percent).
-- States with the highest percentages of preschoolers included Utah (9.7 percent), Texas (8.3 percent) and Idaho (7.9 percent). States with the lowest percentages were Vermont (5.2 percent), Maine (5.4 percent) and New Hampshire (5.7 percent).
Unless otherwise specified, the data refer to the population who reported a
race alone or in combination with one or more other races. The detailed tables show data for
both this group and those who reported a single race only. Censuses and surveys permit respondents to select more than one race; consequently, people may be one race or a
combination of races. Hispanics may be any race.
The federal government treats Hispanic origin and race as separate and distinct concepts. In surveys and censuses, separate questions are asked on Hispanic origin and race. The question on Hispanic origin asks respondents if they are Spanish, Hispanic or Latino. Starting with Census 2000, the question on race asked respondents to report the race or races they
consider themselves to be. Thus, Hispanics may be of any race.
(See U.S. Census Bureau Guidance on the Presentation and Comparison of Race
and Hispanic Origin Data http://www.census.gov/population/www/socdemo/compraceho.html)
These data are based on estimates of U.S. population for July 1, 2007. The Census Bureau estimates population change from the most recent decennial census (Census 2000) using annual data on births, deaths and international migration. More detailed information on the methodology used to produce these estimates can be found at http://www.census.gov/popest/topics/methodology/.
Wednesday, May 14, 2008
Although participation in government assistance programs has risen somewhat in recent years among mothers with a birth in the last year, it is much lower than when welfare reform was enacted in 1996, according to a report released today by the U.S. Census Bureau.
The report, Participation of Mothers in Government Assistance Programs: 2004, analyzes the socioeconomic characteristics of mothers participating in six different public assistance programs. These include Temporary Assistance to Needy Families (TANF); food stamps; Special Supplemental Nutrition Program for Women, Infants and Children (WIC); Medicaid; housing assistance; and other assistance. It shows that in 1996, 42 percent of mothers with a birth in the previous year were participants in at least one of these programs. The rate dipped to 29 percent in 2001 before climbing to 34 percent in 2004. The corresponding number, 1.6 million in 1996, dipped to 1.2 million in 2001 before rising to 1.4 million in 2004.
Overall, 7.5 million mothers of childbearing age (15 to 44), or 22 percent, participated in one or more of these programs in 2004. Those with infants were more likely participants than those with older children (34 percent compared with 20 percent).
Mothers were also more likely to receive public assistance if they were younger than 25, living with either no other adult or with an unmarried partner, a minority, did not work in the past month, never attended college, or did not receive child support.
-- Overall, one in every two participant mothers (52 percent) worked while they received assistance. The rate ranged from 39 percent of those with a recent birth to 55 percent without one.
-- Seventy-eight percent of mothers participating in two or more programs were receiving both Medicaid and food stamps.
-- After accounting for differences in demographic and socioeconomic characteristics, the odds of foreign-born mothers receiving assistance was no different than native mothers.
These data were collected from June 2004 through September 2004 in the Survey of Income and Program Participation. As in all surveys, these data are subject to sampling and nonsampling error. For further information on the source of the data and accuracy of the estimates, including standard errors and confidence intervals, go to http://www.sipp.census.gov/sipp/source.html.
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