Muhammad Asghar

Evaluation of sieve and permeameter analyses methods for subsurface drain envelope laboratory research in Pakistan

Properly designed gravel envelopes for subsurface horizontal drain pipes did not give satisfactory results in the Fourth Drainage Project (FDP), Faisalabad, Pakistan. Poor handling and placing of the granular envelopes were considered the main reasons for failure. This study investigates whether the failure was also because of the existing selection procedures for gravel envelopes or not. USBR design criteria (sieve analysis) were used for distinguishing between the good and poor envelopes. Permeameter experiments for selecting the envelopes for subsurface drain pipes based on these permeameter test results have now been started at SCARP Monitoring Organisation (SMO) in collaboration with the Netherlands Research Assistance Project (NRAP), International Waterlogging and Salinity Research Institute (IWASRI), Lahore. A one-dimensional upward flow permeameter with four rectangular perforated drain plates was used for testing the subsurface drain envelopes. Another hypothesis for this study was to verify the methodology adopted in permeameterexperiments. The effects of sieve and permeameter analyses methods on selection of subsurface drain envelope selection is reported. Following is a recommendation for comparing the permeameter test results obtained in Pakistan with those obtained in Belgium and Canada for worldwide use. This paper also accomplishes the objective of distinguishing between good and poor drain envelopes in a more simple way.

Synthesis and characterization of chitosan modified polyurethane bio-nanocomposites with biomedical potential

A series of chitosan (CS) and montmorillonite (MMT) clay based polyurethane bio-nanocomposites were synthesized by step growth polymerization; reacting hydroxyl terminated polybutadiene (HTPB) and toluene diisocyanate (TDI) to improve thermal and antibacterial properties of polyurethane (PU). Five different PU samples were prepared by varying mole ratio of CS and 1,4-butane diol (from 0 to 2 mol). Structural studies of PUs through FTIR and 1H NMR spectroscopy confirmed the incorporation of CS into the polymer matrix. The scanning electron microscope (SEM) analysis confirmed well dispersion of MMT clay into the PU matrix. Thermogravimetric analysis (TGA) of PUs indicated significant enhancement of thermal stability of PU with addition of CS. Antibacterial properties of PUs were measured by disc diffusion method; showed excellent potential against the selected strains. On the whole, CS showed potential to improve the antibacterial and structural properties of PU significantly; which might be precursor for biological applications.

Influence of 1-methylcyclopropene on physico-chemical properties of ‘gola’ and ‘surahi’ guava (Psidium guajava L.) under air storage

Guava (Psidium guajava L.; Myrtaceae) locally known as ‘Amrood’ is a nutritionally important tropical fruit in Pakistan. It ranks 4 after citrus, mango and date with respect to area (63739 hectares) and production (488017 tonnes) per annum (GOP, 2016). Guava is hundred percent edible and is considered as ‘apple of the poor’ due to its low cost, easy availability and high nutritive value. Guava is highly acceptable for ‘in nature’ consumption as it has been termed as ‘super fruits’ (Kareem et al., 2013; Kanwal et al., 2016). Guava undergoes physiological changes during and after harvest which accelerates ripening process and prevents fruit from being stored successfully (Bassetto et al., 2005). Guava cannot endure extended distance transportation and reach the market in a soft, over-ripe state, which has less value in the marketplace and compromises prosperity of producers (Steinhaus et al., 2008). After-harvest losses are about 2540% of the guava production (Kanwal et al., 2016). Ripening of climacteric fruits like guava is either triggered by natural production of endogenous ethylene or by exogenous ethylene application (Sisler and Serek, 2003). There is strong relationship between ethylene production and expected postharvest shelf life of horticulture produce (Kader and Saltveit, 2003). Guava is a rapidly ripening climacteric fruit, exhibiting ethylene and respiration peaks within 4-5 days after harvest when harvested at mature green stage (Bashir and AbuGoukh, 2003). High levels of ethylene have negative effects such as excessive softening, fruit decay, discoloration, wilting, mold, scald and scald (Lelievre et al., 1997). To increase the post-harvest storage life of guava, one option is to inhibit or slow down the action of ethylene. 1-MCP is alleged to bind the receptors of ethylene in target plant material, preserving fruit from the effect of ethylene (Sisler and Serek, 2003). 1-MCP is believed to work as a competitive gas to ethylene, occupying the ethylene receptor site so that ethylene cannot bind to trigger its action (Blankenship and Dole, 2003). 1-MCP has 10 times greater affinity to bind with receptor sites than ethylene (Sisler and Serek, 2003) and binds ethylene receptor sites strongly as compared to ethylene (Tatsuki et al., 2007). Even a single dose of 1-MCP can make product insensitive to ethylene effects several for days (Sisler and Serek, 2003). The effectiveness of 1-MCP depends on different factors like storage atmosphere and treatment duration (DeEll et al., 2002), treatment temperature (Mir and Beaudry, 2001; Mir et al., 2001), ‘non-target’ material (Vallejo and Beaudry, 2006), stage of maturity (Watkins et al., 2000), cultivar (DeELL et al., 2002; Blankenship and Dole, 2003) and the time between harvest and 1-MCP application (Blankenship and Dole, 2003; Tatsuki et al., 2007). Pak. J. Agri. Sci., Vol. 55(2), 389-396; 2018 ISSN (Print) 0552-9034, ISSN (Online) 2076-0906 DOI: 10.21162/PAKJAS/18.6453 http://www.pakjas.com.pk

Evaluating therapeutic potential of coriander seeds and leaves (Coriandrum sativum L.) to mitigate carbon tetrachloride-induced hepatotoxicity in rabbits

Objective: To evaluate the hepatic and renal protective potential of coriander seeds and leaves using animal feed model. Methods: Coriander seeds- and leaves-based sauces were administrated to normal (Study I) and carbon tetrachloride (2 mL/kg B.W.)-induced hepatotoxic rabbits (Study II). Hepatic and renal biomarkers like aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, superoxide dismutase and catalase were measured. Results: Coriander leaves-based sauce exerted more decline (P<0.05) in serum aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase levels in the study II as 18.32%, 19.91% and 21.24%, respectively. While, hepatic superoxide dismutase and catalase levels were raised significantly (P<0.05) in both studies. Renal parameters also depicted positive impact by the provision of developed sauces. Conclusions: Coriander seeds and leaves based sauces are effective in alleviating the hepato/renal toxicity. The hepatoprotective effect of coriander leaves is more pronounced as compared to coriander seeds.