Characterization and Potent Application of Pleurotus floridanus Trypsin Inhibitor (PfTI)

Manzur Ali Pannippara,Sapna Kesav,Rekha Mol Kollakal Naduvil Raghavan,Abraham Mathew,Sarita Ganapathy Bhat,Elyas Kothanan Kozhiyil 한국생약학회 2020 Natural Product Sciences Vol.26 No.3

Characterization and in vitro inhibition studies of protease inhibitor from the mushroom Pleurotus floridanus (PfTI) towards the pest Papilio demoleus is studied. The addition of 1 mM Mn2+, Na2+, Ba2+ and Ni 2+ enhanced the PfTI activity. The ICP-atomic emission spectrum showed the presence of Ca2+, Mg2+ and Zn2+ in the PfTI. Surfactants SDS and CTAB at a concentration of 1% reduced the PfTI activity whereas, the nonionic detergents Triton X and Tween 80 increased the activity. The inhibitory activity gradually decreased with increase in concentration of DMSO and H2O2. The activity was increased by dithiothreitol up to a concentration of 80 µM and inactivated at 140 µM. The activity of PMSF modified PfTI was drastically reduced to 0.234 U/mL at 4 mM concentration and similar results were obtained for modification of cysteine by N-Ethylmaleimide at slightly higher concentrations. The complex of trypsin and PfTI showed complete loss in fluorescence intensity at 343 nm compared with control. In vitro inhibition studies of PfTI with midgut proteases isolated from citrus pest P. demoleus with protease activity of 1.236 U was decreased to 0.613 U by 50 µL (0.1 mg/mL) of the inhibitor. Inhibitor was stable up to 0.04 M concentration of HCl.

Who Pays for Protection in Malaysia? : A New General Equilibrium Approach

Manzur, Meher,Subramaniam, Alamelu 세종대학교 국제경제연구소 1995 Journal of Economic Integration Vol.10 No.3

This paper uses a simple general equilibrium model to isolate the transfer effects resulting from protection in Malaysia. Ignoring the deadweight losses associated with protection, the model uses the concept of true protection to construct a transfer matrix which shows how income is transferred among various sectors of the economy. The evidence suggests that it is only the exporters who pay for protection. The cost to Malaysian exporters was about 2.56 percent of GDP in 1989.

Who Pays for Protection in Malaysia?: A New General Equilibrium Approach

( Meher Manzur ),( Alamelu Subramaniam ) 세종대학교 경제통합연구소 1995 Journal of Economic Integration Vol.10 No.3

This paper uses a simple general equilibrium model to isolate the transfer effects resulting from protection in Malaysia. Ignoring the deadweight losses associated with protection, the model uses the concept of true protection to construct a transfer matrix which shows how income is transferred among various sectors of the economy. The evidence suggests that it is only the exporters who pay for protection. The cost to Malaysian exporters was about 2.56 percent of GDP in 1989.

Burnt Clay Brick Aggregate for Internal Curing of Concrete under Adverse Curing Conditions

Tanvir Manzur,Sayedur Rahman,Tafannum Torsha,Munaz Ahmed Noor,Khandaker M. Anwar Hossain 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.12

In this study, properties of concrete with brick aggregate as internal curing medium has been investigated under adverse curing conditions. Brick aggregates, commonly known as brick chips (BC), have high porosity and absorption capacity. Desorption tests of different sizes of BC revealed that BC could desorb about 90% of its absorbed water. It was also observed that smaller size BC had higher desorption capacity than that of larger ones. Moreover, higher internal relative humidity was observed for all internally cured (IC) samples as compared to control samples made with 100% rock aggregate particles commonly known as stone chips (SC). Internally cured samples with three different percent replacements (15%, 20% and 25%) of SC with BC were prepared and subjected to six simulated adverse curing conditions. The performance of internally cured concrete under different curing conditions was evaluated in terms of compressive strength, rapid chloride permeability test (RCPT) and linear shrinkage test. The internally cured samples exhibited higher strength and less permeability and shrinkage as compared to their control counterparts under all adverse curing conditions considered in the study. Based on the findings of the study, 20% partial replacement of SC with BC of 9.5 mm in size can be recommended as a guideline for producing internally cured concrete under adverse curing conditions.

Performance of Cement Mortars under Tannery Wastewater

Tanvir Manzur,Sinha Lamia Sultana,Samira Mahmud,Sifat Azad Papry,Swakshar Saha,Mahbuboor Rahman Choudhury 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.11

This research studied the performance of Ordinary Portland Cement (OPC) and Portland Composite Cement (PCC) composites when exposed to tannery wastewater (TWW), which is generated in large quantities in different tannery industries in Bangladesh. With increasing prospects for tanning industries in the country, selection of suitable construction material will enable sustainable development in this sector. TWW consists of several chemicals that have detrimental effects on concrete. Performances of OPC and PCC were measured in terms of strength, expansion, and weight loss. Microstructures of the test specimens were also studied through Scanning Electron Microscopy (SEM), X-ray Powder Diffraction (XRD), and Energy-dispersive Spectroscopy (EDS) analysis. Results revealed that PCC test specimens performed better compared to those of OPC in terms of strength and degradation when exposed to TWW. The inferences made from this study will be helpful for selection of suitable cement type in future structures exposed to similar severe conditions.

Optimum Mix Ratio for Carbon Nanotubes in Cement Mortar

Tanvir Manzur,Nur Yazdani 대한토목학회 2015 KSCE JOURNAL OF CIVIL ENGINEERING Vol.19 No.5

Cementitious composites have high compressive strength and modulus of elasticity, but relatively low tensile strength, toughness and ductility. They are amenable to enhancement through nanotechnology due to the physical behavior and size of hydration products. Carbon Nanotube (CNT) is a very efficient reinforcing agent due to its extremely high aspect ratio and ultra-high strength. So, there is a high potential to utilize CNT in producing new cement based composite materials. In this study, a parametric experimental investigation was undertaken to determine optimum mix dosage of CNT for cement mortar. Different dosage rates of surface treated Multi-Walled Nanotubes (MWNT), water/cement ratios and plasticizer amounts (as surfactant for the MWNT) were investigated through compressive and flexural strength determinations. A mixing technique was proposed to address the issues related to dispersion of nanotubes within the cement matrix. The proposed mixing technique and design mix significantly enhanced the compressive and flexural strengths, as compared to control samples with no MWNT

Optimum Proportion of Masonry Chip Aggregate for Internally Cured Concrete

Shohana Iffat,Tanvir Manzur,Sayedur Rahman,Munaz Ahmed Noor,Nur Yazdani 한국콘크리트학회 2017 International Journal of Concrete Structures and M Vol.11 No.3

Proper curing of concrete is essential for achieving desirable mechanical properties. However, in a developing country like Bangladesh, curing is often neglected due to lack of proper knowledge and skill of local contractors. Consequently, general concreting work of the country has been found to have both strength and durability issues. Under such scenario, internal curing could be adopted using masonry chip aggregate (MCA) which is quite common in this region. It is observed that saturated MCA desorbs water under favorable relative humidity and temperature. This paper presents the effectiveness of MCA as internal curing medium and recommends a tentative optimum mix proportion to produce such concrete. The experimental study was conducted in two phases. It was found that 20% replacement of stone chips with MCA produced better performing internally cured concrete both in terms of strength and durability. Performance of internally cured concrete with recommended proportion of MCA is comparable to that of normally cured control concrete samples with conventional stone chips. In addition, internally cured concrete performed significantly better than control samples when kept under similar adverse curing conditions. In the absence of supply of external water for curing, compressive strength of internally cured concrete for 20% replacement can be as high as 1.5 times the strength of the control concrete samples. Significant better performance in permeability than that of control samples was also observed for this percent replacement under such adverse curing conditions.

Durability Performance of Internally Cured Concrete Using Locally Available Low Cost LWA

Shohana Iffat,Tanvir Manzur,Munaz Ahmed Noor 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.4

Curing of concrete is important to ensure both strength and durability. Loss of water through evaporation reduces the hydration rate and eventually results in limited strength and higher permeability. Generally, curing is done by supplying additional water from external sources to prevent the water loss. Such curing requires skilled labor and proper knowledge. However, in a developing country like Bangladesh, it is considered as an additional step and often neglected. Under such scenario, Internal Curing (IC) could be adopted to improve the overall quality of general concreting work. Utilization of locally available burnt clay chip aggregate commonly known as Brick Chips (BC) to produce internally cured concrete can be considered as an effective solution. The pore spaces of these aggregates absorb water during saturation process and later desorb water under favorable conditions of higher temperature and low relative humidity. As a result, no external curing water is needed. This study shows the durability performance of concrete having BC as internal curing medium. Stone chips have been partially replaced by BC since concrete with BC alone produces weaker concrete. Three commonly practiced water cement ratios of 0.4, 0.45 and 0.5 and five curing conditions were selected to simulate inside and outside environmental conditions. Three different percent replacements (10%, 20% and 30%) of stone chips by BC were selected. Control samples with stone chips were also made for comparison. Water permeability test and Rapid Chloride Permeability Test (RCPT) were performed. It is found that durability of internally cured concrete with polythene sheet covering is comparable to the durability of normally cured control concrete. Moreover, under adverse curing conditions with no supply of external water, internally cured concrete performed significantly better than control samples. Therefore, BC can be used as a cost effective internal curing material in Bangladesh to produce durable concrete.

FOREIGN DIRECT INVESTMENT IN CANADA

Dorothee J Feils,Manzur Rahman People&Global Business Association 1998 Global Business and Finance Review Vol.3 No.2

We examine the importance of various economic and social factors on the flow of foreign direct investment (FDI) into Canada between 1980 and 1994. We find that international trade, home country GDP and cultural distance are significant factors that influence the FDI flow into Canada. The per capita GDP, relative cost of funds, rate of return, exchange rates, geographic distance and the implementation of the free trade agreement show no significant impact on the flow of FDI into Canada. The regressions have much more explanatory power when the United States FDI is included in the sample.

Experimental Evaluation of Deteriorated CMPs Retrofitted by Different Non-invasive Approaches

Shaurav Alam,Tanvir Manzur,John Matthews,Chris Bartlett,Erez N. Allouche 대한토목학회 2021 KSCE JOURNAL OF CIVIL ENGINEERING Vol.25 No.11

Corrugated metal pipes (CMPs) deployed across North America are in various states of deteriorations with diminishing structural health that can cause road failure and pose serious threat to public safety. This paper presents an extensive experimental study conducted on deteriorated and retrofitted CMPs, and compares the results with available analytic approach - Modified Iowa equation. Simulated deterioration was performed on the new CMPs using mechanical approach and later, those CMP specimens were retrofitted using four different non-invasive methods. The specimens were tested under five different overburden pressures. Responses of the soil-pipe systems for deteriorated and rehabilitated specimens in terms of surrounding soil pressure and deformations at crown, spring-line, and invert were recorded and compared. It was found that the soil envelops and the CMPs experienced considerable change in pressure and deflections, respectively due to deterioration. However, rehabilitation using all the invasive approaches helped to regain soil pressures and deflections close to the original state, indicating their viability. The measured deflections from experimental studies were also compared with the predicted values obtained from the Modified Iowa equation. Such comparison is of immense importance to establish design guidelines for rehabilitated liner-CMP culvert systems.