• Title/Summary/Keyword: Rajshahi

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Biological Control of Alternaria Fruit Rot of Chili by Trichoderma Species under Field Conditions

  • Begum, Most. Ferdousi;Rahman, M.A.;Alam, M. Firoz
    • Mycobiology
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    • v.38 no.2
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    • pp.113-117
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    • 2010
  • Trichoderma strains were evaluated under field conditions to assay their efficacy in suppressing Alternaria fruit rot disease and promoting chili plant growth. The experiment was conducted at the Botanical Garden, Rajshahi University, Bangladesh from July 2006 to March 2007. Application of Trichoderma harzianum IMI 392432 significantly (p = 0.05) suppressed the disease compared to Alternaria tenuis (T2) treatment and improved both growth and yield. The treatment T4 (T. harzianum IMI-392432 + A. tenuis) was most effective in reducing disease percentage (72.27%) compared to A. tenuis (T1) treatment. The highest seed germination rate (85.56%) and the highest growth and yield (12.5 g/plant) was also recorded in the same treatment (T4), followed by T5 (T. harzianum IMI-392433 + A. tenuis), T6 (T. harzianum IMI-392434 + A. tenuis), T2 (T. virens IMI-392430 + A. tenuis), and T3 (T. pseudokoningii IMI-392431 + A. tenuis) treatment, while single treatment with A. tenuis significantly decreased these values.

In vitro Inhibition Effect of Plant Extracts, Urine, Fertilizers and Fungicides on Stem Rot Pathogen of Sclerotium rolfsii

  • Alam, Shahidul;Islam, M. Rafiqul;Sarkar, Montaz Ali;Alam, M.S.;Han, Kee-Don;Shim, Jae-Ouk;Lee, Tae-Soo;Lee, Min-Woong
    • Mycobiology
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    • v.32 no.3
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    • pp.128-133
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    • 2004
  • Twenty plant extracts were tested against mycelial growth, sclerotium formatiom and dry weight of mycelium with sclerotia of Sclerotium rolfsii Sacc. The highest(90 mm) mycelial growth was measured in Adhatoda vasica, Tegetes erecta, Allium cepa, and Curcuma longa. The lowest(25 mm) was in Azadirachta indica. No mycelial growth was found in any concentration of cow, buffalo, and goat urine. The highest(90 mm) and the lowest(15 mm) mycelial growth were measured in Biomil and Urea, respectively. No mycelial growth was observed in Zinc. The highest(60 mm) and the lowest(2 mm) mycelial growth were recorded in Macuprex(Dodine; 65% WP) and Boron(100% Boric acid and 17% Boron) respectively. Mycelial growth was totally inhibited in Rovral(Iprodione; 50% WP).

Corrosion of Steel Rebar in Concrete: A Review

  • Akib Jabed;Md Mahamud Hasan Tusher;Md. Shahidul Islam Shuvo;Alisan Imam
    • Corrosion Science and Technology
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    • v.22 no.4
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    • pp.273-286
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    • 2023
  • Rebar is embedded in concrete to create reinforced concrete (RC). Rebar carries most of the tensile stress and gives compressively loaded concrete fracture resistance. However, embedded steel corrosion is a significant cause of concern for RC composite structures worldwide. It is one of the biggest threats to concrete structures' longevity. Due to environmental factors, concrete decays and reinforced concrete buildings fail. The type and surface arrangement of the rebar, the cement used in the mortar, the dosing frequency of the concrete, its penetrability, gaps and cracks, humidity, and, most importantly, pollutants and aggressive species all affect rebar corrosion. Either carbonation or chlorides typically cause steel corrosion in concrete. Carbonation occurs when carbon dioxide in the atmosphere combines with calcium within the concrete. This indicates that the pH of the medium is falling, and the steel rebar is corroding. When chlorides pass through concrete to steel, corrosion rates skyrocket. Consideration must be given to concrete moisture. Owing to its excellent resistance, dry concrete has a low steel corrosion rate, whereas extremely wet concrete has a low rate owing to delayed O2 transfer to steel surfaces. This paper examines rebar corrosion causes and mechanisms and describes corrosion evaluation and mitigation methods.

Ultrahigh Birefringence and Extremely Low Loss Slotted-core Microstructure Fiber in Terahertz Regime

  • Habib, Md. Ahasan;Anower, Md. Shamim;Hasan, Md. Rabiul
    • Current Optics and Photonics
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    • v.1 no.6
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    • pp.567-572
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    • 2017
  • A novel slotted-core hexagonal photonic crystal fiber (PCF) for terahertz (THz) wave guiding is proposed in this paper. A trade-off managed between effective material loss (EML) and birefringence for efficient guidance of THz waves is illustrated in this article. The rectangular slot shaped air-holes break the symmetry of the porous-core which offers ultra-high birefringence of $8.8{\times}10^{-2}$. The proposed structure offers low bending loss of $1.07{\times}10^{-34}cm^{-1}$ and extremely low effective material loss (EML) of $0.035cm^{-1}$ at an operating frequency of 1.0 THz. In addition other guiding properties such as power fraction, dispersion and confinement loss are also discussed. The proposed THz waveguide can be effectively used for convenient transmission of THz waves.

Evaluation of Bamboo Reinforcements in Structural Concrete Member

  • Siddika, Ayesha;Al Mamun, Md. Abdullah;Siddique, Md. Abu Bakar
    • Journal of Construction Engineering and Project Management
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    • v.7 no.4
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    • pp.13-19
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    • 2017
  • This study is based on the use and performance of bamboo reinforcements in construction of low-cost structures. This study investigated the physical and mechanical properties of bamboo reinforcements. Bamboo reinforced concrete beam specimens were tested with different reinforcement ratios and observed the load capacity, deflection and failure patterns. It was observed that, flexural strength of bamboo reinforced column is sufficient higher than plain cement concrete and comparable to steel reinforced concrete beams. Bamboo reinforced concrete columns with different reinforcement ratio also tested and observed the ultimate compressive strength and failure pattern. It found, all columns failed in a similar pattern due to crushing of concrete. According to cost analysis, bamboo reinforced beams and columns with moderate reinforcement ratio showed the best strength-cost ratio among plain cement concrete and steel reinforced concrete.

Neoplastic and Hematological Effects of Endosulfan and Bleomycin in the Swiss Albino Mice Mus musculus

  • Sharmin, Tanjina;Ferdousi, Zennat;Islam, M. Saiful;Khan, M.Z.H.;Rahman, Atiqur
    • Applied Biological Chemistry
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    • v.51 no.4
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    • pp.294-298
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    • 2008
  • Effects of endosulfan (EN), an insecticide, and bleomycin (BL), an antibiotic, on the body weight in the normal mice, and the in vivo cell growth, tumor weight, and hematological parameters of the Ehrlich ascites carcinoma (EAC) cell-bearing Swiss albino mice Mus musculus were evaluated. EN and BL were respectively administered orally and intraperitoneally to the experimental mice; the control group consisted of EAC cell-bearing untreated mice only. EN reduced the body weight in normal mice, whereas BL resulted in a steady body weight compared to the control. EN increased the EAC cell count significantly by reducing the growth of normal viable cells. In contrast, BL reduced the cell count by increasing the proportion of viable cells in the body. The tumor weights induced by EN were significantly higher than those of the EAC control and the BL-treated animals. In comparisons with the control and the BL mice, hematological parameters such as hemoglobin (%) and the number of RBC and lymphocytes were lowered, while counts of WBC, neutrophils, and monocytes were elevated after EN treatments. These results show that BL is capable of reducing the EN-induced neoplastic and haematological alterations in the mice under laboratory conditions.

Biological Screening of a Novel Nickel (II) Tyrosine Complex

  • Islam, Md. Rafiqul;Islam, S.M. Rafiqul;Noman, Abu Shadat Mohammod;Khanam, Jahan Ara;Ali, Shaikh Mohammad Mohsin;Alam, Shahidul;Lee, Min-Woong
    • Mycobiology
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    • v.35 no.1
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    • pp.25-29
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    • 2007
  • A newly synthesized Nickel (II) tyrosine complex was screened as potential antimicrobial agent against a number of medically important bacteria (Bacillus subtilis, Streptococcus ${\beta}$-haemolytica, Escherichia coli, Shigella dysenterae) and fungi (Aspergillus fumigatus, Candida albicans, Aspergillus niger, Aspergillus flavus, Penicillium sp.) strains. were used for antifungal activity. The antimicrobial activity was evaluated using the Agar Disc method. Moreover, the minimum inhibitory concentration of the complexes was determined against the same pathogenic bacteria and the values were found between $4{\sim}64\;{\mu}g\;ml^{-1}$. Brine shrimp bioassay was carried out for cytotoxicity measurements of the complexes. The $LC_{50}$ values were calculated after probit transformation of the resulting mortality data and found to be 6 ${\mu}g\;ml^{-1}$.

Magnetic and Temperature-Sensitive Composite Polymer Particles and Adsorption Behavior of Emulsifiers and Trypsin

  • Ahmad, Hasan;Rahman, M.Abdur;Miah, M.A. Jalil;Tauer, Klaus
    • Macromolecular Research
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    • v.16 no.7
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    • pp.637-643
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    • 2008
  • A combination of magnetic and temperature-responsive properties in the same polymer composites is expected to increase their potential applications in the biomedical field. Accordingly, micron-sized magnetite/polystyrene/poly(2-dimethylaminoethyl methacrylate-ethyleneglycol dimethacrylate), which are abbreviated as $Fe_3O_4$/PS/P (DM-EGDM) composite polymer particles, were prepared by the seeded copolymerization of DM and EGDM in the presence of magnetite/polystyrene ($Fe_3O_4$/PS) particles. $Fe_3O_4$/PS/P(DM-EGDM) composite particles with magnetic properties showed a temperature-sensitive phase transition at approximately $31^{\circ}C$. The adsorption behavior of the low molecular weight emulsifiers and trypsin (TR) as biomolecules were examined on $Fe_3O_4$/PS/P(DM-EGDM) composite polymer particles at different temperatures. The native conformation of TR was followed by measuring the specific activity under various adsorption conditions. The activity of the adsorbed TR on composite polymer particles was higher than those of the tree TR and TR adsorbed on $Fe_3O_4$/PS particles.

Screening of Trichoderma Isolates as a Biological Control Agent against Ceratocystis paradoxa Causing Pineapple Disease of Sugarcane

  • Rahman, M.A.;Begum, M.F.;Alam, M.F.
    • Mycobiology
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    • v.37 no.4
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    • pp.277-285
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    • 2009
  • In this study, dual culture, poison agar, and direct methods were used to assess the ability of Trichoderma virens IMI-392430, T. pseudokoningii IMI-392431, T. harzianum IMI-392432, T. harzianum IMI-392433, and T. harzianum IMI-392434 to control Ceratocystis paradoxa, which causes the pineapple disease of sugarcane. The highest percentage inhibition of radial growth (PIRG) values were observed with T. harzianum IMI-392432 using two dual culture methods, 63.80% in Method I and 80.82% in Method II. The minimum colony overgrowth time was observed with T. harzianum IMI-392432 and the maximum was observed with T. pseudokoningii IMI-392431. Different concentrations of different day-old metabolites of Trichoderma isolates were tested against mycelial growth of C. paradoxa. The highest PIRG (84.685%) exhibited at 80% concentration of 30-day-old metabolites of T. harzianum IMI-392432 using the modified bilayer poison agar method. In the direct assay method the maximum mycelial growth weight (PIGW) was observed at the same concentration and the same day-old metabolites of T. harzianum IMI-392432. This study showed that Trichoderma isolates have a good antagonistic effect on C. paradoxa mycelial growth and T. harzianum IMI-392432 has the most potential to control the pineapple disease pathogen.

Antimicrobial Activities and Probiotic Properties of Bacillus sp. Strains Isolated from Fermented Cooked Rice

  • Mst. Sarmin Sultana;Maya Khatun;Ajijur Rahman
    • Microbiology and Biotechnology Letters
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    • v.52 no.3
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    • pp.288-297
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    • 2024
  • Fermented cooked rice is known to have remedial properties and good for health, but there is a lack of scientific knowledge to prove their beneficial effects. In this study, we investigated the presence of antibiotic-producing bacteria in fermented cooked rice. The probiotic properties of the bioactive isolates were also investigated. A total of seven pure isolates were isolated from fermented cooked rice prepared from parboiled cooked Aus rice in the lab following traditional methods. All the isolates were gram-positive, can grow at thermophilic range of temperatures, and all but CRS9 were able to coagulate milk. Three strains exhibited moderate to high broad-spectrum antibacterial activity against the test bacteria including Shigella brodie, Bacillus cereus, Escherichia coli, Pseudomonas sp., Staphylococcus aureus, and Proteus sp. Analysis of 16S rDNA sequences of the strain CRS8 and CRS11 showed that they belong to the genus Bacillus as they exhibited >99% identity to several strains of Bacillus. Both strains could survive the highly acidic conditions and can tolerate bile acid indicating their potential to be the candidate probiotic strains. The strain CRS8 was resistant to penicillins and cephalosporins including amoxicillin, penicillin, cephalothin, however, the CRS11 was sensitive to all the antibiotics tested. This is the first report that fermented cooked rice is a source of antibiotic-producing Bacillus sp. The probiotic properties of the Bacillus isolates from fermented cooked rice were also investigated for the first time.