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Natural fiber-reinforced composites have attracted interest along with public and industry awareness of the depletion of non-renewable material resources. Considerations of environmental friendliness and low cost have provided a stimulus for researchers to identify green materials that provide a low pollutant index. The high cellulose content in sugarcane bagasse is quite attractive in manufacturing composite materials due to abundant raw materials and low processing costs. Based on their characteristics, sugarcane bagasse composites have advantages in the form of being more flexible, high strength, high tensile strength, easy to shape and adjust, and cheaper. Therefore, the composite of sugarcane bagasse biopolymer can be developed in this era and the future generation. The main ingredients for making biocomposites from sugarcane bagasse are sugarcane bagasse, additional strengthening agents, bonding agents, and alkali. This composite will have strong, flexible, and adaptable properties if processed properly. Composites from sugarcane biopolymer waste can be applied in various sectors such as construction, food, furniture, automotive, and health. Using sugarcane bagasse as a renewable composite material will support various engineering that can be carried out from the process of utilizing sugarcane bagasse waste to manufacture environmentally friendly materials.

A continual increase in the quantity of wastes produced make stabilization of waste dumps a formidable task both from economic and technological standpoints. Of late, bio-engineering approach has been emerging as one of the most, affordable, eco-friendly, efficient and widely used methods of stabilizing such waste dumps. This study enumerates various plant species that can be used to reinforce coal mine waste dumps, the factors that affect the choice, and the techniques used to measure their effectiveness as a bio-engineering tool. The outcome of this work can be used for the selection of suitable plant species that would ensure long-term maintenance of the ecosystem as well as mechanical stability of the dumps. Locally available native species that are likely to blend in with the surroundings and adapt quickly to the climate have been suggested for the vegetation of sterile dumps. The Miyawaki plantation approach is recommended as it promotes higher survival, aids in ecological restoration, and improves the mechanical stability of the dump slope.

Use of the flushing media contributes to the improvement in the overall performance of drilling operations. The paper reports findings of the laboratory scale work carried out on a rotary drilling machine using sandstone rock samples. This study was conducted to develop a process to optimize the fluid flushing rate and to understand the role of drilling fluid through real-time data generation. From the laboratory experimentation, it was found that, while working with optimum flushing rate, up to 500% increment in rate of penetration (ROP) has been observed. And, also 50% reduction in ROP was noticed with the increment in depth of drilling from 3 to 12 mm. The outcome of the study convincingly demonstrates that fluid flushing rate plays a vital role in the improvement of the overall efficiency of the drilling operation of the laboratory setup.

The depths of open-pit mines have been increasing in the last few decades. This transformation generates a vast amount of waste rock material per unit mining area imposing a significant economic, social and environmental liability on the mine operators. The scarcity of dumping land along with the rise in population, competing urbanization and associated environmental clearance problems require accommodating this ever-growing volume of waste rock material at restricted available space. On the contrary, the frequency of accidents due to the instability of the waste dump slope structures has also increased, resulting in significant fatalities, apart from the economic, social and environmental impacts of these disasters. Numerous scientific studies have been conducted to reduce the occurrence of such incidents. This paper conducts a critical review of the numerical modelling-based stability analysis of such waste dump slope structures. The popularly cited cases of dump slope instability have been analysed to synthesize pertinent findings regarding the approach of stability analysis, broader design criteria, and optimization. The critical parameters to numerical modelling-based design of a safe dump slope structure are discussed in detail. The significant output parameters, apart from the factor of safety, are also outlined for evaluating the state of stability.

Pervasive wireless computing and communication have created an ever-increasing demand for more radio spectrum. Since, most of the spectrum is underutilized, it motivated the introduction of the concept of cognitive radios, a dynamic spectrum access enabling technology. The first stage of cognitive radio is to sense the environment and determine which parts of the spectrum are available. This is achieved through spectrum sensing. However, spectrum sensing poses the most fundamental challenge in cognitive radios. Moreover, cognitive radios suffer from many vulnerabilities and the security attacks can severely degrade the performance of cognitive radios. This paper surveys state-of-the-art research on spectrum sensing and security threats in cognitive radios. Lastly, we also consider the analysis of issues related to spectrum handoffs in cognitive radios.

With the advent of advanced geographical informational systems (GIS) and remote sensing technologies in recent years, topographic (elevation, slope, aspect, and flow accumulation) and vegetation attributes are routinely available from digital elevation models (DEMs) and normalized difference vegetation index (NDVI) at different spatial (remote sensor footprint, watershed, regional) scales. Based on the correlation of soil distribution and vegetation growth patterns across a topographically heterogeneous landscape, this study explores the use of topographic and vegetation attributes in addition to pedologic attributes to develop pedotransfer functions (PTFs) for estimating soil hydraulic properties in the Southern Great Plains of the USA. The extensive Southern Great Plains 1997 (SGP97) hydrology experiment database was used to derive these functions by using artificial neural networks. Eighteen models combining bootstrapping technique with artificial neural networks were developed in a hierarchical manner to predict the soil water contents at eight different soil water potentials (θ at 5, 10, 333, 500, 1000, 3000, 8000, and 15 000 cm) and the van Genuchten hydraulic parameters (θr, θs, α, n). The performance of the neural network models was evaluated using the Spearman correlation coefficient between the observed and the predicted values and root mean square error (RMSE). Although variability exists within bootstrapped replications, improvements (of different levels of statistical significance) were achieved with certain input combinations of basic soil properties, topography and vegetation information compared with using only the basic soil properties as inputs. Topography (DEM) and vegetation (NDVI) attributes at finer scales were useful to capture the variations within the soil mapping units for the SGP97 region dominated by perennial grass cover.

There is a considerable interest currently in the development of DNA sequence specific or selective agents for genetic targeting for the control of gene expression, for application in diagnosis or ultimately in therapy. In this context CC-1065 is one of the most impressive lead compounds isolated in trace quantities from the culture of Streptomyces zelensis at Upjohn in 1978. The unique structure was confirmed by single X-ray in 1981. However CC-1065 cannot be used in humans because it was found that it caused delayed deaths in experimental animals. In the search for compounds with better antitumor selectivity and DNA sequence specificity many CC-1065 analogs have been synthesized in an attempt to avoid the undesired side effects while retaining its potency against tumor cells. Two successful attempts in the modification in the active moiety of the parent natural product 1,2,8,8a-tetrahydro-7-methylcyclopropa[3,2-e]indole-4- one (CPI) and 1,2,9,9a-tetrahydrocyclopropa[c]benz[e]indole-4-one (CBI) have been made. We review here recent progress with the analogs of CPI and CBI and their conjugates both by solution and solid phase, also the progress and development of CPI and CBI conjugates with polyamides (information reading molecules in the minor groove of DNA). Since CPI-CPI dimers are significantly more potent than CC-1065 in vitro and in vivo, a large number of CBI-CBI dimers with varying linkers lengths and positions synthesized in our group and their pharmacological properties have been reviewed.

Imidazole and compounds containing imidazole residues have been shown to cleave RNA in an RNase A-mimicking manner. Di-imidazole lexitropsin is a compound which is derived from the polyamide drugs distamycin and netropsin essentially by the replacement of two pyrrole heterocycles with N-methyl-imidazole residues. This enables it to bind to the minor groove of B-DNA in a sequence-specific manner. We demonstrate here that this lexitropsin derivative has RNA cleavage activity, as tested on model RNAs. Optimal cleavage conditions and cleavage specificity resemble those known from other imidazole conjugates and are thus consistent with an RNase A type cleavage mechanism. The optimum concentration of the compound for cleavage is similar to previously investigated imidazole-based RNase mimics. As a whole new class of chemical compounds capable of interacting with nucleic acids through extensive hydrogen bonding, these imidazole containing compounds constitute promising scaffolds and ligands, for the construction of novel RNase mimics with high affinity.

Analysis of the structural and stereochemical requirements for the strict DNA base-sequence recognition of (AT)4 and (AT)5, respectively, for the oligopeptide minor-groove binding agents netropsin (I) and distamycin (II) leads to proposals for the rational structure modification for altered base recognition. In this paper we report the synthesis of unsymmetrical imidazo-pyrrolo-bis(polyamides), structurally related to the natural antiviral agents distamycin, and bearing either unnatural (25−27) or natural (31−33) termini linked by a flexible or rigid linker. This is the first report of the synthesis of an imidazole-bearing structure with either dimethylaminopropyl or amidinium termini in the linked bis(polyamides).

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.