Food security through increasing technical efficiency and reducing postharvest losses of rice production systems in Bangladesh

Rice accounts for nearly 70 % of calories consumed in Bangladesh. Therefore, any effort to improve food security in the country must find ways to increase availability of rice. This paper investigates two of these ways: increasing technical efficiency of rice production and reducing post-harvest losses. Technical efficiency was measured from Cobb-Douglas and translog production functions for the rice production seasons Aus (spring), Aman (summer) and Boro (winter). Efficiency estimates ranged from 73 to 83 %, suggesting that the potential exists for substantial increases in rice production while continuing to use current technologies and inputs. Variables influencing technical efficiency were farm size, level of famers’ education, farmers’ experience in production, microcredit, training and extension. Post-harvest losses between farmer and retailer were estimated at 10–12 %, suggesting potentially an additional source of rice without changes in production. Reduction of postharvest losses were significantly related to the availability of extension services.     

Multi objective optimization of performance parameters of a single cylinder diesel engine with hydrogen as a dual fuel using pareto-based genetic algorithm

The present experimental investigation attempts to explore the performance characteristics of an existing single-cylinder four-stroke compression-ignition engine operated in dual-fuel mode with hydrogen as an alternative fuel. Experimental investigation was conceded with the engine being subjected to different loads at a predefined flow rate of hydrogen induction. A Timed Manifold Injection (TMI) system has been developed to vary the injection timing and the durations. The optimized timing for the injection of hydrogen was 10⁰ CA after top dead center (ATDC). From the study it was observed that hydrogen with diesel results in increased brake thermal efficiency (BTHE) by 15.7% at 40% full load, volumetric efficiency (Vol. Eff.) by 78.5% at full load condition compared to baseline diesel operation. Hydrogen enrichment registered a maximum reduction of 41.4% in specific fuel consumption (SFC) of diesel at 20% full load. A pareto-optimal front was then obtained using nondominated sorting genetic algorithm (NSGA). Analysis of the front was done to identify the separate regions for Brake specific energy consumption (BSEC), Brake thermal efficiency (BTHE) and Volumetric efficiency (Vol. Eff.). Designed experiments were then conducted in these focused regions to verify the optimization results and to identify the region– specific characteristics of the process.     

Micro-Raman Characterization of the Phase Transition Behavior in Lanthanum Doped Lead Titanate Thin Films

Lanthanum-modified lead titanate, Pb 1 m x La x Ti 1 m x/4 O 3 (PLT), films with different compositions, such as x = 0.05, 0.10, 0.15, 0.20, 0.25 and 0.30 were deposited on platinized silicon substrates using the sol-gel process. Raman scattering technique was utilized to study the dynamics of phase transitions and possible relaxor behavior in these compositions in a wide range of temperatures 100-873K. The outcome indicates change of the structure with the increase of La doping, as well as an increase in diffused phase transition behavior. The residual intensities of phonons above the tetragonal-to-cubic phase transition temperature suggest a diffuse nature of the ferroelectric phase transition, due to the short-range structural disorder in the paraelectric cubic phase. The Lyddane-Sachs-Teller (LST) relations were employed to analyze changes in the Raman mode positions in order to obtain the optical dielectric constants. The results are in good agreement with the previous dielectric studies.     

An analysis of the eddy effect in through-silicon vias based on Cu and CNT bundles: the impact on crosstalk and power

Journal of Computational Electronics - The performance of three-dimensional integrated circuits primarily depends on the filler material used in the through-silicon vias (TSVs). The most widely...     

Growth and structural characterization of lanthanum doped lead titanate fiber

Abstract

Lanthanum doped lead titanate Pb_1?x La_x Ti_1?x/4 O₃ fibers (x '0, 5 and 15 at%) were grown by sol-gel technique and characterized for their phase formation behavior and crystal structure. The precursor sol was concentrated upon heating at 100°C to make it spinnable and used for fiber drawing. For heat treatment, a two-step heating schedule was designed on the basis of DSC analysis of the as drawn fibers. X-ray diffraction analysis showed that the tetragonality of the Lead Titanate (PT) fibers reduces with La doping and the structure is changed to pseudocubic from tetragonal. MicroRaman Spectroscopy confirms these observations of change in crystal structure and distortion in the material due to La doping. Dense and elongated grains of about 1 μm diameter were observed at the surface and at the cross section of PT fibers. La doped fibers show a porous fracture surface and also the grain size reduces dramatically with the addition of La. Strain energy is believed to play a major role in the observed changes in the microstructure.     

Short range structural disorder in lanthanum doped lead titanate thin films

Abstract

Spin coated Pb_1?xLa_xTi_1?x/4Q₃ thin films (x ' 0.00, 0.05.…0.30) on (0001) sapphire were studied using x-ray diffraction, atomic force microscopy, and Raman scattering in order to investigate the phase formation, surface morphology, and the phase transition behavior in them. The x-ray and Raman scattering reveal a decrease in tetragonality with La substitution in lead titanate. Microscopy estimated surface roughness was also found to be decreasing with the La doping. Raman scattering, in the temperature range 75–783K, shows the transition temperature about 730, 680, 614, and 563 K for x'0.05, 0.10, 0.15, and 0.20 compositions, respectively. The diffuse nature of the ferroelectric phase transition owing to a short-range structural disorder in the paraelectric cubic phase and an increase in the diffuseness with La doping indicates the relaxor behavior and its relationship with the local disorder in these materials.     

Protecting copper from electrochemical degradation by graphene coating

Graphene coating on copper (Cu) is shown to increase the resistance of the metal to electrochemical degradation by one and half orders of magnitude. Detailed electrochemical characterization in aggressive chloride environment shows the impedance of Cu increasing dramatically and the anodic and cathodic current densities of the coated Cu becoming nearly 1–2 orders of magnitude smaller when coated with graphene. The observations are counterintuitive as graphite in contact with metals increases metallic corrosion. The results can bring paradigm changes in the development of anti-corrosion coatings using conformal, ultrathin graphene films.     

A new approach for identification of novel antihypertensive peptides from egg proteins by QSAR and bioinformatics

Many protein-derived bioactive peptides were identified after extensive activity-guided purification, which is labor-intensive and costly. Furthermore, the rationale behind the selection of a substrate protein and a protease over others has not been justified in literature. The purpose of the study was to explore the rationale behind the selection of conditions for the production of potent angiotensin I converting enzyme (ACE) inhibitory peptides from egg proteins. Based on in silico digestion and quantitative structure and activity relationship (QSAR) model prediction, thermolysin-pepsin digestion of ovotransferrin was chosen as the best condition due to the presence of three potent peptides, Ile-Arg-Try, Leu-Lys-Pro and Ile-Gln-Try. To our surprise, sequences of Ile-Arg-Try-Cys-Thr, Leu-Lys-Pro-Ile and Ile-Gln-Try-Cys-Ala, but not Ile-Arg-Try, Leu-Lys-Pro and Ile-Gln-Try, were present in the hydrolysate. Further study showed that sonication or reducing agent pre-treatments could improve the activity of hydrolysates over 20 times and the predicted peptides were successfully released from sonication-treated ovotransferrin hydrolysate.     

The effect of cross-linked chains of polymer network on the memory states of polymer stabilized ferroelectric molecules

We proposed a microscopical model by suitably considering the interaction between ferroelectric ordering and polymer cross-links. Based on the proposed model, we obtained the reduced behavior of the tilt angle, rotational viscosity and the spontaneous polarization with the increase of polymer concentration in the composite system. A perfect surface stabilization is obtained at the cost of a little reduction of tilt angle for polymer stabilized ferroelectric liquid crystal (PSFLC). It was observed that the interacting cross-linked polymer chains played an important role in promoting multistability and resolution of the memory state in the composite system.     

Oxygen radical absorbance capacity of peptides from egg white protein ovotransferrin and their interaction with phytochemicals

Egg proteins are important components for the development of functional foods and nutraceuticals. This study investigated the oxygen radical-scavenging effects of egg white protein ovotransferrin (including the whole protein, thermolysin–pepsin hydrolysate, and its bioactive peptides) and their interactions with four phytochemicals (vitamin C, epigallocatechin gallate (EGCG), caffeic acid, and quercetin), based on the oxygen radical absorbance capacity (ORAC) assay. The results showed that the hydrolysate possessed significantly higher oxygen radical absorbance capacity than the whole protein. The peptide IRW possessed very strong oxygen radical-scavenging effect, which might be attributed to its constitutive amino acid tryptophan (W) and the peptide bond between arginine (R) and W. Both the hydrolysate and the whole protein of ovotransferrin showed negative effects on four phytochemicals. However, the interactions between peptides/amino acids and the four phytochemicals are complex: some are positive, while others are negative. The results suggest that not only the phytochemicals, but also the hydrolysates or the peptides from the egg proteins could be a potential source of natural antioxidants.