https://repository.auw.edu.bd/handle/123456789/741 2026-05-13T21:10:11Z 2026-05-13T21:10:11Z Meaze, A. K. M. M. H. https://repository.auw.edu.bd/handle/123456789/920 2026-02-18T06:15:29Z 2020-01-01T00:00:00Z

Analysis of Percentage Depth Dose for 6 and 15 MV Photon Energies of Medical Linear Accelerator With CC13 Ionization Chamber Meaze, A. K. M. M. H. The success of external beam radiotherapy is mainly depended on how to commission and safety precaution is maintained before beam is heated to infected cells. CC13, an intermediate size ionization chamber is frequently used for the commissioning process of dose calculation for both standard and non-standard sizes field. The measurements of PDDs (Percentage of Depth Dose) were performed using TG-51 at the North East Cancer Hospital, Bangladesh using Varian Clinac IX-5982 with 6 MV & 15 MV photon beam energies for a set of 9 field sizes (4 × 4, 6 × 6, 8 × 8, 10 × 10, 15 × 15, 20 × 20, 25 × 25, 30 × 30 and 40 × 40 cm2 ), keeping the same conditions such as pressure, temperature, incremental step, direction, geometry, chamber voltage, and polarity. The PDD for 6 & 15 MV photon beams were obtained with the above mentioned field sizes and at SSD 100 cm. The obtained PDD results showed that maximum dose depth (dmax) for above all mentioned field sizes were varied within 11.8 to 15.8 mm and 21.9 to 29.9 mm respectively for 6 and 15 MV photon energies. In modern clinical radiotherapy PDD is the most essential parameters for the commissioning of medical linear accelerator. Our measured values for depth dose (dmax) and PDD applying TG-51 protocol at 10 cm depth (d10) for both 6 MV and 15 MV photon energies are found within the international refereed limits.

2020-01-01T00:00:00Z Meaze, AKM Moinul H. https://repository.auw.edu.bd/handle/123456789/919 2026-02-18T06:15:10Z 2020-01-01T00:00:00Z

A multi-slotted antenna for LTE/5G Sub-6 GHz wireless communication applications Meaze, AKM Moinul H. This paper presents a low-profile multi-slotted patch antenna for long term evolution (LTE) and fifth-generation (5G) communication applications. The studied antenna comprised of a stepped patch and a ground plane. To attain the required operating band, three slots have been inserted within the patch. The insertion of the slots enhances the capacitive effect and helps the prototype antenna to achieve an operating band ranging from 3.15 to 5.55 GHz (S11 ≤−10 dB), covering the N77/N78/N79 for sub-6 GHz 5G wireless communications and LTE bands of 22/42/43/46. The wideband antenna presented in this paper offers omni- directional stable radiation patterns, good gains, and efficiency with a compact size which make this design an ideal contender for wireless fidelity (WiFi), wireless local area network (WLAN), LTE, and sub-6 GHz 5G communication applications.

2020-01-01T00:00:00Z Meaze, A K M M H https://repository.auw.edu.bd/handle/123456789/916 2026-02-18T06:14:56Z 2020-01-01T00:00:00Z

Evaluations of n + 27Al reaction in the energy range 0.1–200 MeV Meaze, A K M M H As 27Al has important applications in reactor science and technology, perfect understanding of its various cross sections in the wide range of energy is indispensable. Scarcity of experimental data particularly in high energy makes theoretical evaluation essential. In the present work, different neutron interaction cross sections of 27Al in the energy range 0.1–200 MeV have been evaluated by TALYS 1.9. The reaction grid, outgoing light particle production and probable production routes are also analyzed. The present evaluations are compared with the available experimental and evaluated nuclear data: ENDF/B-VIII, JENDL-4.0, etc. This is generally in good agreement except 0.7–6 MeV of projectile energies. In this energy range, diffuseness and geometrical parameters are adjusted to overcome the disagreement. In the lower- energy region, mainly elastic scattering is observed. Shape of non-elastic curve is well produced; however, there is small energy shift between evaluated and experimental data.

2020-01-01T00:00:00Z Meaze, AKM Moinul Haque https://repository.auw.edu.bd/handle/123456789/915 2026-02-18T06:15:00Z 2020-01-01T00:00:00Z

The presence of toxic metals in popular farmed fish species and estimation of health risks through their consumption Meaze, AKM Moinul Haque This study concerns an assessment of essential and toxic metals (Zn, Cu, As, Cr and Cd) in some popular farm fishes which are largely consumed by the populations of the Southern region in Bangladesh. Three different species of fish (T. nilotica, P. pangasius and L. rohita) were collected from four representative farms located in the Fatickchari, Hathazari, Patiya and Raozan Upazila of Chittagong district. Flame Atomic Absorption Spectrometer (FAAS) and Graphite Furnace Atomic Absorption Spectrometer (GFAAS) were used to measure the metal con- centrations. The order of concentration of metals in flesh was Zn > Cu > Cr > As > Cd with values of 16.205 0.303 > 0.874 0.037 > 0.590 0.05 >0.042 0.003 > 0.004 0.00 (mg/kg dw) in T. nilotica, 20.324 0.697 > 1.035 0.050> 0.577 0.074> 0.045 0.005 > 0.006 0.000 (mg/kg dw) in P. pangasius and 22.270 0.745 > 0.953 0.525 > 0.623 0.060 > 0.035 0.002 > 0.004 0.000 (mg/kg dw) in L. rohita. Measured data lie within the permissible limits recommended by WHO/FAO. Potential metal toxicity to human health following the consumption of the studied fishes was estimated via a number of hazard parameters: Daily intake of metal (DIM), Target hazard quotient (THQ), Hazard index (HI) and Target risk (TR), all of the data show values within the recommended level given by regulatory bodies. Estimated TR for potential carcinogenic metals As, Cr and Cd were found in the range (106 - 105 ), which lies within the US-EPA risk range of 106 - 104 . Note that, fish consumption forms a minor part of the total diet while the US-EPA risk range is for the dietary intake from all foods. Therefore the estimated risk may not be totally neglected. Moreover, considering the non-biodegradability of toxic metals and their potential uptake in fish tissues, reduction in metal supplementation in fish feed should be introduced and periodic monitoring of fish may help to mitigate non-essential metal toxicity to consumers.

2020-01-01T00:00:00Z