Investigations on the Three Commercial Species of Rosaceae

Physico-chemical properties of the seed oils of three species of Rosaceae family, namely Prunus armeniaca (apricot), Prunus cerasifera (prune), and Prunus persica (peach) have been determined. Fatty acid composition of the oils and amino acids composition of seed cake proteins have also been determined and their utility in every day life has been discussed.     

Seed Oil Based Zinc Bioactive Polymers: Synthesis, Characterization and Biological Studies

Zinc containing oil based polyesteramide resins were synthesized by condensation polymerization reaction between castor/soyabean oil derived castor/soyabean fatty amide diol (HECA/HESA), Zn (OH)₂ and adipic acid. The conventional spectroscopic techniques such as FTIR, ¹HNMR, ¹³CNMR have been used to establish the structure of the polymers. Standard laboratory methods were used to study the physicochemical characteristics like acid value, hydroxyl value, saponification value, iodine value, specific gravity, and viscosity. The thermal behaviour of the polymers was analyzed by using thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC). In vitro antifungal (anticandidial) activity of the polymers was studied against C. albicans ATCC-10261, C. glabrata ATCC-90030 and C. tropicalis ATCC-750, respectively. Antibacterial activity against Gram positive (S. subtillis) and Gram negative bacteria (E. coli and S. typhi) was also examined. For more accuracy, growth curve studies were carried out with the polymer SZ showing higher biological activity against E. coli by using conventional spectrophotometer. The result showed that the polymers have potent anticandidial and antibacterial activities.     

Sensitivity-Enhanced CMOS Phase Luminometry System Using Xerogel-Based Sensors

We present the design and implementation of a phase luminometry sensor system with improved and tunable detection sensitivity achieved using a complementary metal-oxide semiconductor (CMOS) integrated circuit. We use sol-gel derived xerogel thin films as an immobilization media to house oxygen (O₂) responsive luminescent molecules. The sensor operates on the principal of phase luminometry wherein a sinusoidal modulation signal is used to excite the luminophores encapsulated in the porous xerogel films and the corresponding phase shift of the emission signals is monitored. The phase shift is directly related to excited state lifetimes of the luminophores which in turn are related to the concentration of the target analyte species present in the vicinity of the luminophores. The CMOS IC, which consists of a 16 times 16 high-gain phototransistor array, current-to-voltage converter, amplifier and tunable phase shift detector, consumes an average power of 14 mW with 5-V power supply operating at a 38-kHz modulation frequency. The output of the IC is a dc voltage that corresponds to the detected luminescence phase shift with respect to the excitation signal. As a prototype, we demonstrate an oxygen sensor system by encapsulating the luminophore tris(4,7-diphenyl-1,10-phenanthroline)ruthenium(II) within the xerogel matrices. The sensor system showed a fast response on the order of few seconds and we obtained a detection sensitivity of 118 mV per 1% change in O₂ concentration. The system demonstrates a novel concept to tune and improve the detection sensitivity for specific concentrations of the target analyte in many biomedical monitoring applications.     

Quality assessment of polymer replication by hot embossing and micro-injection moulding processes using scanning mechanical microscopy

This paper describes observations and metrological analyses made to compare the replication quality of polymeric replicas obtained by filling micro-cavities using both hot embossing and micro-injection moulding processes. The experiments are performed with polypropylene (PP) at a constant melt temperature and a constant mould temperature, whereas hot embossing tests are carried out with the same polymer at temperatures close to the softening one.The results concerning the micro-cavities filling provide information on the reliability about the possibilities of replication topographical surface geometries. The data obtained by scanning mechanical microscopy (SMM) are used to determine the comparative filling ratio values.     

A Direct Method to Calculate the Frequency and Duration of Failures for Large Networks

This paper presents a method to find the frequency and duration of outage of large complex networks through the network approach. Unreliable nodes can be considered. Numerical examples are given to elucidate the theory. The results from this technique are fairly accurate. A feature of the method is that it can handle large systems having reliable nodes with a present day computer. Even for those systems which contain unreliable nodes, the number of combinations of unreliable nodes required is much less than the number of terms needed by any path or cutset enumeration method. The use of delta-star transformations introduces some error in the results, but the error is small enough as seen from the numerical values for the examples solved in this paper.     

Social learning for adaptive delta management: Tidal River Management in the Bangladesh Delta

ABSTRACT

The article analyzes Tidal River Management in Bangladesh from a social learning perspective. Four cases were investigated using participatory assessment. Knowledge acquisition through transformations in the Tidal River Management process was explored as an intended learning outcome. The study finds that social learning occurred more prominently at the individual stakeholder level and less at the collective level. For Tidal River Management to be responsive and sustainable, especially in times of increased uncertainty and climate vulnerability, more attention needs to be paid to coordination and facilitation of multi-level learning that includes all stakeholders.     

Modeling for Various Design Options of a Canal System

Irrigated agriculture is backbone of economy in many countries worldwide, including Pakistan with its large irrigation system. Systemic Enhancements are periodically implemented to improve the performance of the system. In this paper the performance of canals has been investigated for various operations. Data regarding discharge of outlets and the canals was collected by field measurements. Crop-water requirements, bed slope of canals, cross-sectional details, longitudinal profile and outlet details, were obtained from the Irrigation Department. It was noticed that the performance of canals is not satisfactory under prevailing conditions. Different operational strategies for change of unlined to lined conditions, different discharge conditions and outlet dimensions were evaluated using CanalMan model. It was established through extensive research that the performance of the canals can be improved by lining and changing outlet dimensions. Modified dimensions of outlets for better performance were estimated by iterative method of optimization.     

Multiple responses analysis and modeling of Fenton process for treatment of high strength landfill leachate

Landfill leachate is one of the most recalcitrant wastes for biotreatment and can be considered a potential source of contamination to surface and groundwater ecosystems. In the present study, Fenton oxidation was employed for degradation of stabilized landfill leachate. Response surface methodology was applied to analyze, model and optimize the process parameters, i.e. pH and reaction time as well as the initial concentrations of hydrogen peroxide and ferrous ion. Analysis of variance showed that good coefficients of determination were obtained (R2 > 0.99), thus ensuring satisfactory agreement of the second-order regression model with the experimental data. The results indicated that, pH and its quadratic effects were the main factors influencing Fenton oxidation. Furthermore, antagonistic effects between pH and other variables were observed. The optimum H2O2 concentration, Fe(II) concentration, pH and reaction time were 0.033 mol/L, 0.011 mol/L, 3 and 145 min, respectively, with 58.3% COD, 79.0% color and 82.1% iron removals.     

Optimizing Approach of Water Allocation to Off-Takes During Reduced Flows

Multi-objective optimization models with an index were developed based on farmers’ preferences, local requirements, supplies available at the head of the canal, system losses, crop demand about different growth stages, and field soil moisture balance. The models were applied using linear programming. The Model 1 determines the cropping pattern by maximizing net economic benefits using a monthly basis lumped volume available at the head of the canal and is set to the minimum and maximum area constraints along with the constraint of minimum main crop area. The areas for different crops given by the first model form input for the Model 2. The other inputs of Model 2 included periodic supply available at the head of the primary canal (7-day period in this study), root growth depth, demand, and soil moisture constants. The Model 2 optimizes the sum of relative yields of all the crops and provide the irrigation levels of various crops for specified periods. Finally, the distributed area and irrigation levels determined by Model 2 are used in conjunction with the losses to decide flow rates of off takes. The complete program was implemented in the West branch irrigated area of Mirpurkhas subdivision. The results showed that the resources were allocated to off-takes in a competitive and conflict-free manner.