Arif Rahman - Academia.edu (original) (raw)

Papers by Arif Rahman

Research paper thumbnail of Fiber optic microcellular system composite triple beat reduction using the Golomb ruler

The in-band composite triple beat (CTB) generated by intensity modulating the laser diode can lim... more The in-band composite triple beat (CTB) generated by intensity modulating the laser diode can limit the performance of the fibre optic micro-cellular system, as they cannot be filtered off. This CTB maximises at the middle channels when the carriers are equally spaced. However, it can be reduced by rearranging the way the channels are employed. One of which is to

Research paper thumbnail of Fifth order versus third order intermodulation distortion

The third order intermodulation distortion (IMD 3 ) rather than the fifth order intermodulation d... more The third order intermodulation distortion (IMD 3 ) rather than the fifth order intermodulation distortion (IMD 5 ) is often considered when examining the performance of an analogue fibre optic system. This paper aims at looking into the possibility of the IMD 5 being comparable to the IMD 3 . The IMD 5 generated when the laser is intensity-modulated by the multiple carriers signal is simulated and compared to the IMD 3 . Individual IMD 5 level is found to be lower than the IMD 3 when the RF powers of the individual carriers are low or the modulation index per channel is low. However the composite IMD 5 level at channel position could exceed the composite IMD 3 especially when modulation index increases. This is contributed by the number of IMD 5 being greater than that of the IMD 3 based on counting. Hence indicating the IMD 5 should not be neglected in examining the performance of the analogue fibre optic system driven by multiple carriers.

Research paper thumbnail of Interaction of kaolinite with calcite on heatingI. instrumental and procedural factors for one kaolinite in air and nitrogen

Thermochimica Acta, 1987

The degree of distortion of the calcite endotherm on differential thermal analysis (DTA) curves f... more The degree of distortion of the calcite endotherm on differential thermal analysis (DTA) curves for kaolinite-calcite mixtures depends on the kaolinite sample used as well as on the factors previously established. Although no two of the ten kaolinite samples employed, even if from the same general locality, produced identical effects under all experimental conditions, a general relationship between locality of origin and degree of distortion was noted. The crystalline species detected in the products of heating, after standing in air at room temperature, included portlandite, calcite, aragonite, vaterite and the hightemperature phases gehlenite, c(-Ca2SiO, and 12CaO. 7A1203. The actual species present again depended on the kaolinite sample. Although the results cannot be directly related to the volatiles evolved along with water on dehydroxylation of the different kaolinites, a tentative explanation is offered on the basis of the effects of the volatiles on the surfaces of the particles present.

Research paper thumbnail of Interaction of kaolinite with calcite on heating. II. mixtures with one kaolinite in carbon dioxide

Thermochimica Acta, 1988

The degree of distortion of the calcite endotherm on differential thermal analysis (DTA) curves f... more The degree of distortion of the calcite endotherm on differential thermal analysis (DTA) curves for kaolinite-calcite mixtures depends on the kaolinite sample used as well as on the factors previously established. Although no two of the ten kaolinite samples employed, even if from the same general locality, produced identical effects under all experimental conditions, a general relationship between locality of origin and degree of distortion was noted. The crystalline species detected in the products of heating, after standing in air at room temperature, included portlandite, calcite, aragonite, vaterite and the hightemperature phases gehlenite, c(-Ca2SiO, and 12CaO. 7A1203. The actual species present again depended on the kaolinite sample. Although the results cannot be directly related to the volatiles evolved along with water on dehydroxylation of the different kaolinites, a tentative explanation is offered on the basis of the effects of the volatiles on the surfaces of the particles present.

Research paper thumbnail of A 90-nm Low-Power FPGA for Battery-Powered Applications

IEEE Transactions on Computer-aided Design of Integrated Circuits and Systems, 2007

ABSTRACT Programmable logic devices such as FPGAs are useful for a wide range of applications. Ho... more ABSTRACT Programmable logic devices such as FPGAs are useful for a wide range of applications. However, FPGAs are not commonly used in battery-powered applications because they consume more power than ASICs and lack power management features. In this ...

Research paper thumbnail of BAB I PROSES PERKEMBANGAN BAYI

Kehamilan dan kelahiran dianggap sebagai suatu kejadian fisiologis yang pada sebagian besar wanit... more Kehamilan dan kelahiran dianggap sebagai suatu kejadian fisiologis yang pada sebagian besar wanita berakhir dengan normal dan tanpa komplikasi (Departmen of Health, 1993). Pada akhir masa puerperium, pemulihan persalinan secara umum dianggap telah lengkap. Pandangan ini mungkin terlalu optimis. Bagi banyak wanita, pemulihan adalah sesuatu yang berllangsung terjadi dan menjadi seorang ibu adalah proses fisiologis yang normal. Namun, beberapa studi terbaru mengungkapkan bahwa masalahmasalah kesehatan jangka panjang yang terjadi setelah melahirkan adalah masalah yang banyak ditemui (Hillan, 1992b; glazener et al. 1993; bick dan MacArthur, 1995a) dsan dapat berlangsung dalam waktu lama (macArthur et al. 1991).

Research paper thumbnail of Fiber optic microcellular system composite triple beat reduction using the Golomb ruler

The in-band composite triple beat (CTB) generated by intensity modulating the laser diode can lim... more The in-band composite triple beat (CTB) generated by intensity modulating the laser diode can limit the performance of the fibre optic micro-cellular system, as they cannot be filtered off. This CTB maximises at the middle channels when the carriers are equally spaced. However, it can be reduced by rearranging the way the channels are employed. One of which is to

Research paper thumbnail of Fifth order versus third order intermodulation distortion

The third order intermodulation distortion (IMD 3 ) rather than the fifth order intermodulation d... more The third order intermodulation distortion (IMD 3 ) rather than the fifth order intermodulation distortion (IMD 5 ) is often considered when examining the performance of an analogue fibre optic system. This paper aims at looking into the possibility of the IMD 5 being comparable to the IMD 3 . The IMD 5 generated when the laser is intensity-modulated by the multiple carriers signal is simulated and compared to the IMD 3 . Individual IMD 5 level is found to be lower than the IMD 3 when the RF powers of the individual carriers are low or the modulation index per channel is low. However the composite IMD 5 level at channel position could exceed the composite IMD 3 especially when modulation index increases. This is contributed by the number of IMD 5 being greater than that of the IMD 3 based on counting. Hence indicating the IMD 5 should not be neglected in examining the performance of the analogue fibre optic system driven by multiple carriers.

Research paper thumbnail of Interaction of kaolinite with calcite on heatingI. instrumental and procedural factors for one kaolinite in air and nitrogen

Thermochimica Acta, 1987

The degree of distortion of the calcite endotherm on differential thermal analysis (DTA) curves f... more The degree of distortion of the calcite endotherm on differential thermal analysis (DTA) curves for kaolinite-calcite mixtures depends on the kaolinite sample used as well as on the factors previously established. Although no two of the ten kaolinite samples employed, even if from the same general locality, produced identical effects under all experimental conditions, a general relationship between locality of origin and degree of distortion was noted. The crystalline species detected in the products of heating, after standing in air at room temperature, included portlandite, calcite, aragonite, vaterite and the hightemperature phases gehlenite, c(-Ca2SiO, and 12CaO. 7A1203. The actual species present again depended on the kaolinite sample. Although the results cannot be directly related to the volatiles evolved along with water on dehydroxylation of the different kaolinites, a tentative explanation is offered on the basis of the effects of the volatiles on the surfaces of the particles present.

Research paper thumbnail of Interaction of kaolinite with calcite on heating. II. mixtures with one kaolinite in carbon dioxide

Thermochimica Acta, 1988

The degree of distortion of the calcite endotherm on differential thermal analysis (DTA) curves f... more The degree of distortion of the calcite endotherm on differential thermal analysis (DTA) curves for kaolinite-calcite mixtures depends on the kaolinite sample used as well as on the factors previously established. Although no two of the ten kaolinite samples employed, even if from the same general locality, produced identical effects under all experimental conditions, a general relationship between locality of origin and degree of distortion was noted. The crystalline species detected in the products of heating, after standing in air at room temperature, included portlandite, calcite, aragonite, vaterite and the hightemperature phases gehlenite, c(-Ca2SiO, and 12CaO. 7A1203. The actual species present again depended on the kaolinite sample. Although the results cannot be directly related to the volatiles evolved along with water on dehydroxylation of the different kaolinites, a tentative explanation is offered on the basis of the effects of the volatiles on the surfaces of the particles present.

Research paper thumbnail of A 90-nm Low-Power FPGA for Battery-Powered Applications

IEEE Transactions on Computer-aided Design of Integrated Circuits and Systems, 2007

ABSTRACT Programmable logic devices such as FPGAs are useful for a wide range of applications. Ho... more ABSTRACT Programmable logic devices such as FPGAs are useful for a wide range of applications. However, FPGAs are not commonly used in battery-powered applications because they consume more power than ASICs and lack power management features. In this ...

Research paper thumbnail of BAB I PROSES PERKEMBANGAN BAYI

Kehamilan dan kelahiran dianggap sebagai suatu kejadian fisiologis yang pada sebagian besar wanit... more Kehamilan dan kelahiran dianggap sebagai suatu kejadian fisiologis yang pada sebagian besar wanita berakhir dengan normal dan tanpa komplikasi (Departmen of Health, 1993). Pada akhir masa puerperium, pemulihan persalinan secara umum dianggap telah lengkap. Pandangan ini mungkin terlalu optimis. Bagi banyak wanita, pemulihan adalah sesuatu yang berllangsung terjadi dan menjadi seorang ibu adalah proses fisiologis yang normal. Namun, beberapa studi terbaru mengungkapkan bahwa masalahmasalah kesehatan jangka panjang yang terjadi setelah melahirkan adalah masalah yang banyak ditemui (Hillan, 1992b; glazener et al. 1993; bick dan MacArthur, 1995a) dsan dapat berlangsung dalam waktu lama (macArthur et al. 1991).