Stretched State Excitations in the 26-Mg(p,n)26-Al Reaction at 134 MeV

This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440

Nondestructive quality assessment of shogun mandarin fruits (Citrus reticulata Blanco cv. Shogun) using compton scattering of gamma-ray technique

Compton scattering of gamma radiation was applied for nondestructive testing of the shogun mandarin fruits with good quality defined as no dry sack or dry fibrous structures inside. In principle, the scattering deviated angles to the left and right of a gamma ray that penetrates through a homogeneous fibrous structure meat of any orange fruit should be equal. The source Cs-137, with an initial gamma ray activity of 9.25 mCi, placed in a 7 cm thick lead shielding, was radiated through a 10 mm diameter collimator onto any single fruit to be tested. A NaI(Tl)-detector, oriented perpendicular to both left and right of theincoming beam, was placed 5 cm from the fruit. Results showed that the net count rate of the scattering beam between the left and right counting for good-quality shogun mandarin with proper tissue for consumption was less than 85 counts per minute (average 83 cpm), whereas shogun mandarin with dry sack, which were unfit for consumption, had twice that rate or more (average 175 cpm)

Specific activities of radium-226 in vegetables grown in Na Mom District, Songkhla Province

Specific activity of radium-226 in 13 types of vegetables grown in Namom district, Songkhla province, were analyzed using a low background gamma-ray spectrometer. The analyzed vegetables included Ivy Gourd, Yellow Cassia, White Popinac, Yard Long Bean, Rice, Peanut, Egg Plant, Spineless Amaranth, Swamp Cabbage, Mustart, Chinese Cabbage, Collards and Cucumbers. The control vegetables were taken from Bangklum district, 40 km south of Namom district. The samples were weighed, dried in an oven and finally burnt to ash in a furnace before being analyzed for a gamma ray of 186.2 keV emitted from Radium-226. The results showed that the geometrical means of specific activity of radium-226 of vegetables grown in Pijit, Namom, Klongrang and Thungkamin sub-district and over the Namom district were 1082, 1220, 1457, 1253 and 1250 mBq/kg, respectively. The highest and lowest values were 7882 and 26 mBq/kg, found in Ivy Gourd and Yard Long Bean, respectively. The high specific activities of radium-226 in vegetables were found to be distributed uniformly in the area. This probably indicated the source of radium-226 was also distributed uniformly in the shallow granitic bedrock throughout the area. We concluded that the radium-226 contents in vegetables grown in Namom district depended on the absorbability of alkaline earth metals in vegetables themselves, geographic features and radium content in natural water in the area. The estimated annual effective dose averaged over Namom district was 21 μSv. Consumption of Ivy Gourd may receive the maximum annual effective dose of 132 μSv

Natural radioactivity in the area of Nakhon Si Thammarat Province

This research work aims to study the specific activity of natural radioactivity in soil, rock, construction sand and shallow well water samples in the area of Nakhon Si Thammarat Province. Totally 161 samples were collected and analysed using gamma-ray spectrometry technique. The specific activities of Ra-226, Th-232 and K-40 in soil samples ranged from 8 to 203 (mean 96±18) Bq/kg, 12 to 236 (mean 88±23) Bq/kg and 21 to 1191 (mean 524±127) Bq/kg, in rock samples ranged from 11 to 113 (mean 46±14) Bq/kg, 3 to 113 (mean 47±16) Bq/kg and 18 to 1305 (mean 472±187) Bq/kg, in sand samples ranged from 3 to 91 (mean 42±5) Bq/kg, 14 to 91 (mean 50±5) Bq/kg and 102 to 966 (mean 509±57) Bq/kg, respectively. The radium equivalent activity of soil samples in 2 districts was found to be higher than 370 Bq/kg. The radiation hazard indices calculated for assessment of the radiation hazards arising due to the use of these rock and sand samples in the construction of dwellings were within the safety limits recommended by UNSCEAR. The mean estimated outdoor dose rates in soil and rock samples were 119±23 and 70±21 nGy/h, respectively. The mean estimated indoor dose rate in sand samples was 134±9 nGy/h. The specific activities of Ra-226 in well water samples ranged from 2 to 179 (Mean 17±7) mBq/l. Only one water sample from Muang District had the Ra-226 specific activity of 179 mBq/l, which was higher than the maximum contaminant level (111 mBq/l)

Concentration of Ra-226 in shallow well water and its relation with the evidence of oral and esophagus cancers in Namom District,

Altogether 150 water samples were collected from shallow wells widely distributed in Namom district, Songkhla province. Co-precipitation technique was used to absorb radium into co-precipitate Ra-BaSO4, which was measured for Ra-226 using a low background alpha spectrometer. The results showed that the Ra-226 concentration in well water in Namom district ranged 3.51-292.1 mBq/l, with a geometric mean 50.7 mBq/l. Ra-226 concentration in thirty one water samples or 29.31% exceeded 111 mBq/l, which was the maximum contaminant level of the US Environmental Protection Agency. Six villages having an arithmetic mean of Ra-226 concentration in well water exceeding the 111 mBq/l level included Ban Koktang Moo 2, Pijit sub-district; Ban Tungkho Moo 2, Namom sub-district; Ban Lancai Moo 2, Ban Tungpho Moo 3, Tung kamin sub-district; Ban Meapia Moo 3, Ban Tonpling Moo 5, Klongrang sub-district. Ban Tonpling Moo 5 had the highest concentration at 177.8 mBq/l. The high Ra-226 contaminated water wells are generallylocated in granitic basement with associated fault/fracture zones. The estimated annual dose averaged over Namom district was 15.3 μSv while people living in Ban Tonpling Moo 5 met the highest estimated annual dose of 36.3 μSv. However, the ratios between the number of water wells with and without associated oral and esophagus cancer cases in the area where the estimated dose is over and below 8 μSv did not differ significantly

Spectral reflectance of oil-palm (Elaeis guineensis Jacq.) bunches as indicator for optimal harvesting

To determine the appropriate harvesting time of Tenera oil palm bunches, the spectral reflectance of ripening bunches was investigated from images taken by a digital Canon PowerShot A20 camera. Every second day images were taken from selected bunches at an oil-palm estate during the growth of the bunchesfrom immaturity to the over-ripe phase, to trace the changes in color which correlate with the process of ripening. The images were analyzed measuring the changes in the three basic colors red, green and blue, using a specially developed Color Analysis computer program for Oil-palm 'fruit' (CAOP), and determining the correlation with the measured palm-oil content of the nuts.Of the three color-bands, the red light reflectance showed the best correlation with ripeness, as the red color increased regularly and practically linearly up to the stage of the maximal oil yield. Some seven days after the thus determined optimal harvesting date for the ripe bunches, some of the ripe nuts will detachfrom the bunch and fall, but then it is too late to use the fallen nuts as indicators for harvesting. From our investigations in the field and in the laboratory we recommend that harvesting should follow immediately after the red reflectance starts declining, after having reached its peak value for the Tenera oil-palm some 5±3 days before nuts begin to detach from the bunch

Spectral reflectance analysis of longkong (Lansium domesticum Corr.) bunches as an indicator for optimal harvesting

To determine the appropriate harvesting time of Longkong bunches, the spectral reflectance of ripening bunches was investigated from images taken by a digital camera using red LED and green LED. Every day images were taken from selected bunches at a Longkong estate during the growth of the bunches from immaturity to the over-ripe phase, to trace the changes in color that correlate with the process of ripening. The images were analyzed by measuring the changes in the three basic colors i.e. red, green and blue, using a specially developed Color Analysis computer program of Longkong "fruit" (CAOL), and then the obtained results were compared with the sweet in form of total soluble solid (TSS:TA).The result showed that the blue light reflectance from red LED source (Br) was selected as an indicator for harvesting Longkong bunches. Br was inversely proportional to ripeness of Longkong. The blue color intensity decreases linearly while TSS:TA increases monotonously. From our investigations, we suggest that the time interval to harvest Longkong should be within 96 ±7 days after the first flower blossom of that bunch takes place while blue level per pixel was in the range of 8.67-2.39. If Longkong bunch was cut while the blue color level was in the range of 8.67-5.53, its taste will be sweet and sour and strong enough for long distance shipment. But if the blue level per pixel was in the range of 5.52-2.39, it has a very good taste and is suitable a for sale in the local area. In addition, it was also found that the blue level per pixel usually decreased at the rate of 0.45 per day. This made is possible to predict the harvesting day by this technique

Analyzing-power Measurements for (pol.p,n) Reactions

This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440

"0 hω" Stretched States Excited with the (p,n) Reaction on Medium- and Heavy-Mass Nuclei

This research was sponsored by the National Science Foundation Grant NSF PHY 87-1440