No abstract

The effect of annealing temperature on the photocatalyst's structural, morphological, photocatalytic and optical properties have been extensively studied. In this work, the Cu-Ni co-doped TiO2 powder was prepared by the sol-gel technique and annealed at temperatures 400°C, 500°C, 600°C, 700°C, and 800°C. The structural phase of the Cu-Ni/TiO2 changed from anatase to rutile after the annealing temperature increased from 400°C to 800°C. The anatase phase was found at 400°C and 500°C, the mixed phase at 600 and 700°C, and the rutile phase at 800°C. The specific surface area and band gap of Cu-Ni/TiO2 were decreased with the increment of annealing temperatures from 70.00 to 24.89 m2 /g and 3.36 eV to 3.04 eV, respectively. Meanwhile, as the annealing temperature rises, the average particle size increases from 38.52 to 173.59 nm. The anatase-rutile mixed phase of Cu-Ni/TiO2 annealed at 600°C exhibited the highest photocatalytic degradation of methylene blue (MB) with 62.81% MB removal. Experimental results indicated that the annealing temperature could alter the structural, morphological, and optical properties of the Cu-Ni/TiO2, affecting the photocatalytic activity performance.

The fisheries sector in Bangladesh undergoes various post-harvest problems: the high post-harvest loss of fish. As fish is highly perishable, it needs proper handling, processing, and distribution in time. Ice is the major and primary material that is used in Bangladesh for fish preservation. Different methods are used for crushing ice. In the traditional method, ice is crushed with a heavy load by hand. This method is very laborious and most often does not provide a uniform shape. So, an attempt was taken to develop a low-cost ice crusher machine in the Department of Farm Power and Machinery, Bangladesh Agricultural University, Mymensingh. Based on the design and drawing, the machine was manufactured. Necessary materials to construct the machine were collected from the local market. The machine throughput capacity of the developed ice crusher was found 854.85 kg/hr. with an overall loss of 10.5%. Based on the test parameters, the machine performance was found satisfactory. The machine construction cost was estimated as Tk 11048. The operating cost for ice crushing was calculated, and it was found to be Tk 0.07/kg. This machine was simple at construction and the cost is also low, which indicates that the machine is suitable input for ice crushing to the marginal user. Where electricity is not available and large commercial heavy ice crushers are not available, this machine can be very suitable.