Timer error as well as its convention is very important for dose accuracy during irradiation. This paper determines the timer error of irradiators at Secondary Standard Dosimetry Laboratory (SSDL) in Nigeria. The irra...Timer error as well as its convention is very important for dose accuracy during irradiation. This paper determines the timer error of irradiators at Secondary Standard Dosimetry Laboratory (SSDL) in Nigeria. The irradiators are Cs-137 OB6 irradiator and X-ray irradiators at the Protection level SSDL;and Co-60 irradiator at the Therapy Level SSDL. PTW UNIDOS electrometer and LS01 Ionization chamber were used at the Protection Level to obtain doses for both Cs-137 OB6 and X-ray irradiators while an IBA farmer type ionization chamber and an IBA DOSE 1 electrometer were used at the Protection Level SSDL. Single/multiple exposure method and graphical method were used in the determination of the timer error for the three irradiators. The timer error obtained for Cs-137 OB6 irradiator was 0.48 ± 0.01 s, the timer error for the X-ray irradiator was 0.09 ± 0.01 s while the timer error obtained for GammaBeam X200 was 1.21 ± 0.04 s. It was observed that the timer error is not affected by source to detector distance. It was also observed that the timer error of Co-60 Gamma X200 irradiator is increasing with the age of the machine. Source to detector distance and field size do not contribute towards the timer error of the irradiators. The timer error of the Co-60 Gamma X200 irradiator (the only irradiator among the irradiators with a pneumatic system) increases with the age of the irradiator.展开更多
In this paper,the throughput and delay of cooperative communications are derived when solar energy is used and relay node is selected using a timer.The source and relays harvest energy from sun using a photo voltaic s...In this paper,the throughput and delay of cooperative communications are derived when solar energy is used and relay node is selected using a timer.The source and relays harvest energy from sun using a photo voltaic system.The harvested power is used by the source to transmit data to the relays.Then,a selected relay amplifies the signal to the destination.Opportunistic,partial and reactive relay selection are used.The relay transmits when its timer elapses.The timer is set to a value proportional to the inverse of its Signal to Noise Ratio(SNR).Therefore,the relay with largest SNR will transmit first and its signal will be detected by the other relays that will remain idle to avoid collisions.Harvesting duration is optimized to maximize the throughput.Packet’s waiting time and total delay are also computed.We also derive the statistics of SNR when solar energy is used.The harvested power from sun is proportional to the sum of a deterministic radiation intensity and a random attenuation due to weather effects and clouds occlusion.The fixed radiation intensity depends on season,month and time t in hour.The throughput of cooperative communications with energy harvesting from sun was not yet studied.展开更多
随着分子生物学技术蓬勃发展,越来越多的肿瘤学者通过The Cancer Genome Atlas(TCGA)数据库下载高通量测序数据,运用生物信息学分析的方法,识别肿瘤免疫微环境中各种细胞的表达量,进行肿瘤浸润性免疫细胞的分析工作,但是肿瘤与免疫的相...随着分子生物学技术蓬勃发展,越来越多的肿瘤学者通过The Cancer Genome Atlas(TCGA)数据库下载高通量测序数据,运用生物信息学分析的方法,识别肿瘤免疫微环境中各种细胞的表达量,进行肿瘤浸润性免疫细胞的分析工作,但是肿瘤与免疫的相互作用往往十分复杂,临床工作人员面对庞大数据量展开分析工作仍然充满困难,基于此本文介绍一款全面分析肿瘤浸润性免疫细胞及其可视化的数据库TIMER2.0,旨在为临床研究人员轻松识别多种癌症类型与正常组织及免疫细胞浸润之间的基因组学关系,快速运用多种算法掌握肿瘤概况。展开更多
文摘Timer error as well as its convention is very important for dose accuracy during irradiation. This paper determines the timer error of irradiators at Secondary Standard Dosimetry Laboratory (SSDL) in Nigeria. The irradiators are Cs-137 OB6 irradiator and X-ray irradiators at the Protection level SSDL;and Co-60 irradiator at the Therapy Level SSDL. PTW UNIDOS electrometer and LS01 Ionization chamber were used at the Protection Level to obtain doses for both Cs-137 OB6 and X-ray irradiators while an IBA farmer type ionization chamber and an IBA DOSE 1 electrometer were used at the Protection Level SSDL. Single/multiple exposure method and graphical method were used in the determination of the timer error for the three irradiators. The timer error obtained for Cs-137 OB6 irradiator was 0.48 ± 0.01 s, the timer error for the X-ray irradiator was 0.09 ± 0.01 s while the timer error obtained for GammaBeam X200 was 1.21 ± 0.04 s. It was observed that the timer error is not affected by source to detector distance. It was also observed that the timer error of Co-60 Gamma X200 irradiator is increasing with the age of the machine. Source to detector distance and field size do not contribute towards the timer error of the irradiators. The timer error of the Co-60 Gamma X200 irradiator (the only irradiator among the irradiators with a pneumatic system) increases with the age of the irradiator.
基金the Deanship of Scientific Research at Saudi Electronic University for funding this research work through the project number 8092.
文摘In this paper,the throughput and delay of cooperative communications are derived when solar energy is used and relay node is selected using a timer.The source and relays harvest energy from sun using a photo voltaic system.The harvested power is used by the source to transmit data to the relays.Then,a selected relay amplifies the signal to the destination.Opportunistic,partial and reactive relay selection are used.The relay transmits when its timer elapses.The timer is set to a value proportional to the inverse of its Signal to Noise Ratio(SNR).Therefore,the relay with largest SNR will transmit first and its signal will be detected by the other relays that will remain idle to avoid collisions.Harvesting duration is optimized to maximize the throughput.Packet’s waiting time and total delay are also computed.We also derive the statistics of SNR when solar energy is used.The harvested power from sun is proportional to the sum of a deterministic radiation intensity and a random attenuation due to weather effects and clouds occlusion.The fixed radiation intensity depends on season,month and time t in hour.The throughput of cooperative communications with energy harvesting from sun was not yet studied.
文摘随着分子生物学技术蓬勃发展,越来越多的肿瘤学者通过The Cancer Genome Atlas(TCGA)数据库下载高通量测序数据,运用生物信息学分析的方法,识别肿瘤免疫微环境中各种细胞的表达量,进行肿瘤浸润性免疫细胞的分析工作,但是肿瘤与免疫的相互作用往往十分复杂,临床工作人员面对庞大数据量展开分析工作仍然充满困难,基于此本文介绍一款全面分析肿瘤浸润性免疫细胞及其可视化的数据库TIMER2.0,旨在为临床研究人员轻松识别多种癌症类型与正常组织及免疫细胞浸润之间的基因组学关系,快速运用多种算法掌握肿瘤概况。
