Optimization of wind turbine micrositing: A comparative study

The need for energy is an attention required issue for the developing countries. Developing countries are in the grip of the deficit of fossils or hydrocarbons sources of energy. Many countries are looking for the optimal solutions of energy production which are more reliable, pollution free and presume less cost. Pakistan is also in the list of those countries who want to get rid of expensive and polluted means of power production. Power production to fulfill the demand of the country is the biggest challenge for Pakistan. Therefore, many sites are under consideration for greener solutions of the problem. The proposed study is undertaken for the under consideration site, Gharo, Sindh, Pakistan. The present research is undertaken to find out the optimal solution for the wind turbine micrositings. A comparison of present study with different past studies (using different optimization techniques, i.e., genetic algorithm, Monte Carlo simulation method etc.) have been undertaken to prove the results of the present study as better results. The basic objective of the study is to find out the most optimal solution for cost per unit power; therefore, the number of wind turbines is not an issue in the undertaken study however, cost is the function of number of wind turbines and to optimize the solution, MS-Excel is used first to prove that power is a function of Wind speed. Second, genetic algorithm is also used for minimal value of fitness function.     

Evaluation of a biodegradable foam for protective packaging applications

Green Cell^® foam (GCF) is a biodegradable foam packaging material produced from a proprietary cornstarch blend. It is commercially available in a variety of laminations and constructions. Cushioning ability and thermal resistance (R‐value) are the fundamental properties needed to compete against synthetic foams. Since GCF is starch based and biodegradable, a concern was that moisture would likely affect its physical properties. Cushioning characteristics and insulation R‐values of 1 and 2 inch foams were determined as a function of temperature and moisture content. The ASTM method D1596 was used to determine the cushioning properties and an ice melt test was used to determine the thermal resistance. Moisture sorption isotherms were developed at three temperatures (20, 25 and 30°C) to determine its moisture sensitivity. The 1‐inch‐thick foam had lower G values at lower static stresses than synthetic foams, but had higher G values at higher static stresses. The 2‐inch‐foam had G values similar to that of synthetic foam materials. Dimensional changes were observed at higher relative humidity (RH) conditions, especially at 30°C. The R‐values at higher humidities were also less than that of synthetic materials. Copyright © 2007 John Wiley & Sons, Ltd.     

Synthesis of carbon nanotubes using Ni95Ti5 nanocrystalline film as a catalyst

Carbon nanotubes (CNTs) were synthesized by low-pressure chemical vapour deposition (LPCVD) using N2:C2H2:H2 gas mixtures on nanocrystalline Ni95Ti5 film. This nanocrystalline film was deposited on silicon substrate using vapour condensation method. The growth temperature and growth time was kept at 800 degrees C and 30 mins, respectively and the pressure was maintained at 10 Torr. The growth mechanism of CNTs was investigated using FESEM, TEM, HRTEM, and Raman Spectroscopy. From FESEM image of Ni95Ti5 nanocrystalline film, it is clear that the particle size varies from 5-10 nm. EDX analysis suggests that Ni95Ti5 alloy contains Ni and Ti both. It is clear from TEM images that CNTs are multiwalled with the diameter varying from 10-30 nm and length of several micrometers. HRTEM image shows that the structure of these multi-walled nanotube (MWNTs) is bamboo-shaped and the catalyst exists at the tip of MWNTs. Fourier Transform Raman Spectroscopy confirmed that graphitic structure of as-prepared CNTs. Field emission measurements reveal that the carbon nanotubes grown for 30 mins showed a turn-on field of 7.2 V/microm, when the current density achieves 10 microA/cm2. The field enhancement factor was calculated to be 708.50 for carbon nanotubes grown for 30 mins.     

History of genome editing in yeast

For thousands of years humans have used the budding yeast Saccharomyces cerevisiae for the production of bread and alcohol; however, in the last 30–40 years our understanding of the yeast biology has dramatically increased, enabling us to modify its genome. Although S. cerevisiae has been the main focus of many research groups, other non‐conventional yeasts have also been studied and exploited for biotechnological purposes. Our experiments and knowledge have evolved from recombination to high‐throughput PCR‐based transformations to highly accurate CRISPR methods in order to alter yeast traits for either research or industrial purposes. Since the release of the genome sequence of S. cerevisiae in 1996, the precise and targeted genome editing has increased significantly. In this ‘Budding topic’ we discuss the significant developments of genome editing in yeast, mainly focusing on Cre‐loxP mediated recombination, delitto perfetto and CRISPR/Cas.     

Platinum as an electrocatalyst: effect of morphological aspects of Pt/Pt-based materials

Platinum and platinum-based materials with high catalytic performance, and chemical and mechanical stability are vital to electronic devices, biomedical science, optics, petroleum, and automotive industries. Because of the limited supply and high cost of platinum, it is highly desirable to develop new effective methodologies which can decrease the platinum loading by increasing its electrocatalytic properties. Depending upon their size, shape, and morphology, platinum materials have shown significant improvement in the surface catalysed chemical transformation pathways in fuel cell technology. Much research is now focused on the manufacturing and engineering of platinum and platinum-based materials which proffer enhanced catalytic efficiency, and offer chemical and mechanical robustness.     

Memory augmented hyper-heuristic framework to solve multi-disciplinary problems inspired by cognitive problem solving skills

Neural Computing and Applications - This paper proposes a new framework, named Deja-Vu+, which is an extension of Deja Vu framework, a classic study on hyper-heuristic framework with 2R (Record and...     

Field emission study of carbon nanotubes forest and array grown on Si using Fe as catalyst deposited by electro-chemical method

Vertically aligned carbon nanotubes are synthesized by Low Pressure Chemical Vapor Deposition (LPCVD) on Si substrate coated with Fe as a catalyst at a pressure of 20 Torr and at a growth temperature of 600 degrees C. The catalyst film is prepared by electro-chemical method which is very unique and a low cost method. Three precursor gases Acetylene (C2H2), Ammonia (NH3) and Hydrogen (H2) at the flow rate of 20 sccm, 100 sccm and 100 sccm respectively are allowed to flow through the Low Pressure Chemical Vapor Deposition reactor for 10 minutes. Scanning Electron Microscope (SEM) images show that synthesized CNTs are vertically aligned and uniformly distributed with a high density. Raman analysis shows G-band at 1574 cm(-1) and D-band at 1370 cm(-1). The G-band is higher than D-band, which indicates that CNTs are highly graphitized. The field emission measurement reveals good field emission properties of as-grown vertically aligned carbon nanotubes with turn-on field of 1.91 V/microm at the current density 10 mA/cm2. The field enhancement factor is calculated to be 7.82 x 10(3) for as-grown carbon nanotubes.     

Secure and efficient data transfer using spreading and assimilation in MANET

Mobile ad hoc Network (MANET) is a cluster of moveable devices connected through a wireless medium to design network with rapidly changing topologies due to mobility. MANETs are applicable in variety of innovative application scenarios where smart devices exchange data among each other. In this case, security of data is the major concern to provide dependable solution to users. This article presents a secure mechanism for data transfer where sender splits the data into fragments and receiver gets the actual data by assimilating the data fragments. We have presented an Enhanced Secured Lempel-Ziv-Welch (ES-LZW) algorithm that provides cryptographic operations for secure data transfer. In proposed model, we have utilized the disjoint paths to transfer the data fragments from sender side and assimilate these fragments at receiver to get the original data. The messages containing data fragments are compressed and encrypted as well. Our scheme ensures confidentiality, integrity, efficient memory utilization, and resilience against node compromising attacks. We have validated our work through extensive simulations in NS-2.35 using TCL and C language. Results prove that our scheme reduces memory consumption along with less encryption and decryption cost as compared to blowfish especially when plaintext has more repetitive data. We have also analyzed the impact of creating data fragments, fraction of communication compromised, and probability to compromise the data fragments by subverting intermediaries.     

Biodegradation of chlorpyrifos and its hydrolysis product 3,5,6-trichloro-2-pyridinol by Bacillus pumilus strain C2A1

A bacterial strain C2A1 isolated from soil was found highly effective in degrading chlorpyrifos and its first hydrolysis metabolite 3,5,6-trichloro-2-pyridinol (TCP). On the basis of morphology, physiological characteristics, biochemical tests and 16S rRNA sequence analysis, strain C2A1 was identified as Bacillus pumilus. Role of strain C2A1 in the degradation of chlorpyrifos was examined under different culture conditions like pH, inoculum density, presence of added carbon/nutrient sources and pesticide concentration. Chlorpyrifos was utilized by strain C2A1 as the sole source of carbon and energy as well as it was co-metabolized in the presence of glucose, yeast extract and nutrient broth. Maximum pesticide degradation was observed at high pH (8.5) and high inoculum density when chlorpyrifos was used as the sole source and energy. In the presence of other nutrients, chlorpyrifos degradation was enhanced probably due to high growth on easily metabolizable compounds which in turn increased degradation. The strain C2A1 showed 90% degradation of TCP (300 mg L⁻¹) within 8 days of incubation.