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Papers by Zal U'yun Wan Mahmood

Research paper thumbnail of Marine radioactivity concentration in the Exclusive Economic Zone of Peninsular Malaysia: 226 Ra, 228 Ra and 228 Ra/226 Ra

Journal of Radioanalytical and Nuclear Chemistry

The present occurrence of 226 Ra and 228 Ra in marine sediment core and fish from the Exclusive E... more The present occurrence of 226 Ra and 228 Ra in marine sediment core and fish from the Exclusive Economic Zone in the east coast of Peninsular Malaysia were studied. Sediment core and biota in respectively was collected using multicorer device and purchased from local fishermen at identified stations during the cruise expedition conducted in 2008. The purpose of this study was to determine and to make available an inventory of activity concentration levels and activity ratio for these radionuclides in this region. The activity concentrations of 226 Ra and 228 Ra in sediment core and edible part of fish were ranged between 15.9-46.5 and 27.7-87.1 Bq/kg dry wt and; 0.80-2.13 and \0.95-3.57 Bq/kg fresh wt, respectively. Meanwhile, the activity ratios of 228 Ra/ 226 Ra in sediment core and fish were varied with the range between 1.63-2.09 and 0.45-2.38, respectively. Refer to those ranges the activity concentrations of radium isotopes were comparable with other region. Thus, it can be concluded that the occurrence of radium isotopes mainly supplied from terrestrial sources and the factors of assimilation efficiency and transfer coefficient of radium may probably effect to the variation activity concentration of 226 Ra and 228 Ra and its activity ratio in edible part of pelagic and demersal fish obtained in this study.

Research paper thumbnail of Combination of developed in-house method and application of Eichrom Sr resin to determine the radioactivity of 90 Sr in environmental sample

Journal of Radioanalytical …

... 90 Sr in environmental sample Zal U'yun Wan Mahmood • Nik Azlin Nik Ariffin • Abdul ... more ... 90 Sr in environmental sample Zal U'yun Wan Mahmood • Nik Azlin Nik Ariffin • Abdul Kadir Ishak • Norfaizal Mohamed • Mei Wo Yii • Kamaruzaman Ishak • Zainab Pa'wan Received: 13 July 2011 © Akadémiai Kiadó, Budapest, Hungary 2011 ...

Research paper thumbnail of Vertical distribution of 210 Pb and 226 Ra and their activity ratio in marine sediment core of the East Malaysia coastal waters

… of Radioanalytical and …, Jan 1, 2011

Abstract Marine sediment cores were collected from two stations at East Malaysia coastal waters o... more Abstract Marine sediment cores were collected from two stations at East Malaysia coastal waters on June 2004. Activity concentrations of 210Pb in sediment core were ranged from 11 Bqkg-1 to 84 Bqkg-1 dry wt. for SR 01 and 4 Bqkg-1 to 66 Bqkg-1 dry wt. for SB 03. ...

Research paper thumbnail of Radioactivity in the Exclusive Economic Zone of east coast Peninsular Malaysia: distribution trends of 137 Cs in surface seawater

Journal of …, Jan 1, 2011

Research paper thumbnail of Radioactivity distribution of thorium in sediment core of the Sabah-Sarawak coast

… of radioanalytical and …, Jan 1, 2010

Abstract Thorium activity concentrations were measured in seven marine sediment cores taken from ... more Abstract Thorium activity concentrations were measured in seven marine sediment cores taken from Sabah-Sarawak coast on 2004 by using a gravity box corer. Collected sedi-ments were generally homogenous mud which contained much more mixture of silt and clay ...

Research paper thumbnail of Radioactivity of plutonium isotopes, 137 Cs and their ratio in sediment, seawater and biota from the east coast of Peninsular Malaysia

Journal of Radioanalytical and Nuclear Chemistry

This study with sampling expeditions of marine sediment, seawater and biota were performed at 30 ... more This study with sampling expeditions of marine sediment, seawater and biota were performed at 30 stations within Malaysian Exclusive Economic Zone (EEZ). A total of >400 samples were collected to determine the activity concentration of anthropogenic radionuclides (239+240Pu, 137Cs) and their activity ratio (239+240Pu/137Cs) in sediments, seawater and biota. The purpose of this study was to determine the concentration levels

Research paper thumbnail of NORM activity concentration in sediment cores from the Peninsular Malaysia East Coast Exclusive Economic Zone

Journal of Radioanalytical …

... Malaysia (in Malays) 12. Muhammad-Samudi Y, Amran AM, Farhana I, Siti-Qalila MT, Mohd-Rashida... more ... Malaysia (in Malays) 12. Muhammad-Samudi Y, Amran AM, Farhana I, Siti-Qalila MT, Mohd-Rashidan ZA (2006) Malays J Anal Sci 10:35 13. Omar M, Ibrahim MY,Hassan A, Lau HM, Zaharudin A (1990) In: Sohrabi M, Ahmad J

Research paper thumbnail of Intercomparison of techniques for estimation of sedimentation rate in the Sabah and Sarawak coastal waters

Journal of …, Jan 1, 2011

Research paper thumbnail of Variation of 231 Pa, 230 Th and 231 Pa ex/230 Th ex in surface sediments of the Sabah–Sarawak coastal waters

… of Radioanalytical and …

Abstract Protactinium and thorium activities were mea-sured in eight surface sediment taken in 20... more Abstract Protactinium and thorium activities were mea-sured in eight surface sediment taken in 2004 to deter-mine effectiveness scavenging of 231Pa at Sabah–Sarawak coastal waters. The result found that activity ratios of 231Paex/230Thex were ranged from 0.07 to ...

Research paper thumbnail of Behavior and distribution of 239+ 240 Pu and 241 Am in the east coast of Peninsular Malaysia marine environment

… of radioanalytical and …, Jan 1, 2010

Research paper thumbnail of Vertical inventories and fluxes of 210 Pb, 228 Ra and 226 Ra at southern South China Sea and Malacca Straits

… of radioanalytical and …, Jan 1, 2010

Abstract Inventories and fluxes of 210Pb, 228Ra and 226Ra were determined in sediment cores colle... more Abstract Inventories and fluxes of 210Pb, 228Ra and 226Ra were determined in sediment cores collected at nine stations covering of the southern South China Sea and Malacca Straits with the thickness of water column between 42 and 83 m depth. The inventories of 210Pb, ...

Research paper thumbnail of Kepekatan Mn dan Fe dalam Teras Sedimen di Perairan Sarawak dan Sabah

Sains …, Jan 1, 2010

Teras sedimen diambil di lapan stesen sepanjang perairan Sarawak dan Sabah dengan menggunakan kot... more Teras sedimen diambil di lapan stesen sepanjang perairan Sarawak dan Sabah dengan menggunakan kotak teras graviti pada Julai 2004. Teras sedimen dipotong pada sela ketebalan 2 cm untuk pengukuran kepekatan Mn dan Fe dengan menggunakan Spektrometer Jisim-Plasma ...

Research paper thumbnail of Variasi Profil 210 Po dan 210Pb dalam Teras Sedimen di Pesisir Pantai Perairan Sarawak

Research paper thumbnail of Marine radioactivity concentration in the Exclusive Economic Zone of Peninsular Malaysia: 226 Ra, 228 Ra and 228 Ra/226 Ra

Journal of Radioanalytical and Nuclear Chemistry

The present occurrence of 226 Ra and 228 Ra in marine sediment core and fish from the Exclusive E... more The present occurrence of 226 Ra and 228 Ra in marine sediment core and fish from the Exclusive Economic Zone in the east coast of Peninsular Malaysia were studied. Sediment core and biota in respectively was collected using multicorer device and purchased from local fishermen at identified stations during the cruise expedition conducted in 2008. The purpose of this study was to determine and to make available an inventory of activity concentration levels and activity ratio for these radionuclides in this region. The activity concentrations of 226 Ra and 228 Ra in sediment core and edible part of fish were ranged between 15.9-46.5 and 27.7-87.1 Bq/kg dry wt and; 0.80-2.13 and \0.95-3.57 Bq/kg fresh wt, respectively. Meanwhile, the activity ratios of 228 Ra/ 226 Ra in sediment core and fish were varied with the range between 1.63-2.09 and 0.45-2.38, respectively. Refer to those ranges the activity concentrations of radium isotopes were comparable with other region. Thus, it can be concluded that the occurrence of radium isotopes mainly supplied from terrestrial sources and the factors of assimilation efficiency and transfer coefficient of radium may probably effect to the variation activity concentration of 226 Ra and 228 Ra and its activity ratio in edible part of pelagic and demersal fish obtained in this study.

Research paper thumbnail of Combination of developed in-house method and application of Eichrom Sr resin to determine the radioactivity of 90 Sr in environmental sample

Journal of Radioanalytical …

... 90 Sr in environmental sample Zal U'yun Wan Mahmood • Nik Azlin Nik Ariffin • Abdul ... more ... 90 Sr in environmental sample Zal U'yun Wan Mahmood • Nik Azlin Nik Ariffin • Abdul Kadir Ishak • Norfaizal Mohamed • Mei Wo Yii • Kamaruzaman Ishak • Zainab Pa'wan Received: 13 July 2011 © Akadémiai Kiadó, Budapest, Hungary 2011 ...

Research paper thumbnail of Vertical distribution of 210 Pb and 226 Ra and their activity ratio in marine sediment core of the East Malaysia coastal waters

… of Radioanalytical and …, Jan 1, 2011

Abstract Marine sediment cores were collected from two stations at East Malaysia coastal waters o... more Abstract Marine sediment cores were collected from two stations at East Malaysia coastal waters on June 2004. Activity concentrations of 210Pb in sediment core were ranged from 11 Bqkg-1 to 84 Bqkg-1 dry wt. for SR 01 and 4 Bqkg-1 to 66 Bqkg-1 dry wt. for SB 03. ...

Research paper thumbnail of Radioactivity in the Exclusive Economic Zone of east coast Peninsular Malaysia: distribution trends of 137 Cs in surface seawater

Journal of …, Jan 1, 2011

Research paper thumbnail of Radioactivity distribution of thorium in sediment core of the Sabah-Sarawak coast

… of radioanalytical and …, Jan 1, 2010

Abstract Thorium activity concentrations were measured in seven marine sediment cores taken from ... more Abstract Thorium activity concentrations were measured in seven marine sediment cores taken from Sabah-Sarawak coast on 2004 by using a gravity box corer. Collected sedi-ments were generally homogenous mud which contained much more mixture of silt and clay ...

Research paper thumbnail of Radioactivity of plutonium isotopes, 137 Cs and their ratio in sediment, seawater and biota from the east coast of Peninsular Malaysia

Journal of Radioanalytical and Nuclear Chemistry

This study with sampling expeditions of marine sediment, seawater and biota were performed at 30 ... more This study with sampling expeditions of marine sediment, seawater and biota were performed at 30 stations within Malaysian Exclusive Economic Zone (EEZ). A total of >400 samples were collected to determine the activity concentration of anthropogenic radionuclides (239+240Pu, 137Cs) and their activity ratio (239+240Pu/137Cs) in sediments, seawater and biota. The purpose of this study was to determine the concentration levels

Research paper thumbnail of NORM activity concentration in sediment cores from the Peninsular Malaysia East Coast Exclusive Economic Zone

Journal of Radioanalytical …

... Malaysia (in Malays) 12. Muhammad-Samudi Y, Amran AM, Farhana I, Siti-Qalila MT, Mohd-Rashida... more ... Malaysia (in Malays) 12. Muhammad-Samudi Y, Amran AM, Farhana I, Siti-Qalila MT, Mohd-Rashidan ZA (2006) Malays J Anal Sci 10:35 13. Omar M, Ibrahim MY,Hassan A, Lau HM, Zaharudin A (1990) In: Sohrabi M, Ahmad J

Research paper thumbnail of Intercomparison of techniques for estimation of sedimentation rate in the Sabah and Sarawak coastal waters

Journal of …, Jan 1, 2011

Research paper thumbnail of Variation of 231 Pa, 230 Th and 231 Pa ex/230 Th ex in surface sediments of the Sabah–Sarawak coastal waters

… of Radioanalytical and …

Abstract Protactinium and thorium activities were mea-sured in eight surface sediment taken in 20... more Abstract Protactinium and thorium activities were mea-sured in eight surface sediment taken in 2004 to deter-mine effectiveness scavenging of 231Pa at Sabah–Sarawak coastal waters. The result found that activity ratios of 231Paex/230Thex were ranged from 0.07 to ...

Research paper thumbnail of Behavior and distribution of 239+ 240 Pu and 241 Am in the east coast of Peninsular Malaysia marine environment

… of radioanalytical and …, Jan 1, 2010

Research paper thumbnail of Vertical inventories and fluxes of 210 Pb, 228 Ra and 226 Ra at southern South China Sea and Malacca Straits

… of radioanalytical and …, Jan 1, 2010

Abstract Inventories and fluxes of 210Pb, 228Ra and 226Ra were determined in sediment cores colle... more Abstract Inventories and fluxes of 210Pb, 228Ra and 226Ra were determined in sediment cores collected at nine stations covering of the southern South China Sea and Malacca Straits with the thickness of water column between 42 and 83 m depth. The inventories of 210Pb, ...

Research paper thumbnail of Kepekatan Mn dan Fe dalam Teras Sedimen di Perairan Sarawak dan Sabah

Sains …, Jan 1, 2010

Teras sedimen diambil di lapan stesen sepanjang perairan Sarawak dan Sabah dengan menggunakan kot... more Teras sedimen diambil di lapan stesen sepanjang perairan Sarawak dan Sabah dengan menggunakan kotak teras graviti pada Julai 2004. Teras sedimen dipotong pada sela ketebalan 2 cm untuk pengukuran kepekatan Mn dan Fe dengan menggunakan Spektrometer Jisim-Plasma ...

Research paper thumbnail of Variasi Profil 210 Po dan 210Pb dalam Teras Sedimen di Pesisir Pantai Perairan Sarawak