Natural Resources & Engineering最新文献

{"title":"Understanding Acidity-basicity, Oxidising ability, and Reducibility of Nanomaterials","authors":"Prakash Kumar Beura, Nikhil Gangwar, S. Prasad, Rawesh Kumar","doi":"10.1080/23802693.2017.1421501","DOIUrl":"https://doi.org/10.1080/23802693.2017.1421501","url":null,"abstract":"Abstract Temperature programmed desorption, temperature programmed reduction, and temperature programmed oxidation are useful characterization techniques to understand the surface acidity–basicity, oxidizing ability, and reducibility, respectively. From catalytic point of view, the information regarding both amount of acid/base/reducible sites as well as strength of these sites are useful for prediction for a said reaction. Herein, a theoretical ground, instrumental quantitative data, and its interactive presentation have been described to understand it in an interactive manner.","PeriodicalId":414255,"journal":{"name":"Natural Resources & Engineering","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125470201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Melamine paraformaldehyde-based organic mesoporous polymer grafted silver nanoparticles catalyzed nitroarenes reduction under aqueous medium","authors":"S. Islam, R. A. Molla, Kajari Ghosh, D. Das, S. Islam","doi":"10.1080/23802693.2018.1440509","DOIUrl":"https://doi.org/10.1080/23802693.2018.1440509","url":null,"abstract":"Abstract Nitrogen affluent mesoporous polymeric material was synthesized as a novel support. Ag nanoparticles were finely dispersed at the mesoporous polymer via post-synthetic chemical grafting over mesoporous polymelamine (mPMF). The resulting nanomaterial, AgNPs@mPMF was well characterized by HRTEM, SEM, EDX, powder-XRD, TGA and UV-Vis-DRS. The AgNPs@mPMF serves as an effective recyclabe nanocatalyst in the reduction of various nitrobenzenes. Optimization of various reaction conditions were carried out by varying the solvents, reductants and temperature. The synthesized heterogeneous catalytic material is economical, air-stable, reusable and can be easily prepared.","PeriodicalId":414255,"journal":{"name":"Natural Resources & Engineering","volume":"148 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133075350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Degradation of tetracycline antibiotics by advanced oxidation processes: application of MnO2 nanomaterials","authors":"Anjali Pal, Prateeksha Mahamallik, S. Saha, Ankush Majumdar","doi":"10.1080/23802693.2018.1434397","DOIUrl":"https://doi.org/10.1080/23802693.2018.1434397","url":null,"abstract":"Abstract Recently, pharmaceutical and personal care products (PPCPs) have emerged out globally as a new category of harmful contaminant. Tetracycline group of antibiotics (TCs), including tetracycline (TC), oxytetracycline (OTC), tetracycline hydrochloride (TCH) and chlorotetracycline (CTC), is also included in this group. The human health and ecosystem have been affected adversely by TCs. In the last few decades, advanced oxidation processes (AOPs) have come out as one of the most sought out techniques for removing antibiotics from aqueous matrices. Here, we have highlighted and compared the existing MnO2-based degradation methods of TCs. Special reference is made on the application of MnO2 nanosheets as elaborated earlier. The MnO2 is highly porous having very high surface area. Optimization of reaction parameters and the method of TCH degradation is the main focus of the paper. A comparative study of the present method with the existing methods has been done.","PeriodicalId":414255,"journal":{"name":"Natural Resources & Engineering","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126131003","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photo-catalytic or photo-synthetic routes for the decomposition of water – are they realizable dreams?","authors":"B. Viswanathan","doi":"10.1080/23802693.2017.1421451","DOIUrl":"https://doi.org/10.1080/23802693.2017.1421451","url":null,"abstract":"","PeriodicalId":414255,"journal":{"name":"Natural Resources & Engineering","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114677816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An account of doping in carbon dots for varied applications","authors":"Jayasmita Jana, T. Pal","doi":"10.1080/23802693.2017.1421506","DOIUrl":"https://doi.org/10.1080/23802693.2017.1421506","url":null,"abstract":"Abstract In recent times, carbon dots have emerged as new fluorescent probes. The unique electronic and physical properties of carbon dots find significant applications in different fields like sensing, cell-imaging, catalysis, medicine etc. The intriguing fluorescence, cytocompatibility and nontoxicity of carbon dots are considered for their use in biological science also. The inherent fluorescence of carbon dots is dependent on their structure, method of synthesis etc. However, the fluorescence of carbon dots is known to improve through different chemical manipulation techniques. Among them, doping of heteroatoms like nitrogen, boron, phosphorous, sulphur etc. has made a mark as an interesting protocol to improve the emissive property of carbon dots. In this review, the recent processes of doping have been discussed along with the application of doped carbon dots in different fields.","PeriodicalId":414255,"journal":{"name":"Natural Resources & Engineering","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2017-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129029623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of heat-affected zone and mechanical properties of Nd-YAG laser welding process of thin titanium alloy sheet","authors":"G. Królczyk, A. Sedmak, U. Kumar, S. Chattopadhyaya, A. Das, A. Pramanik","doi":"10.1080/23802693.2016.1246278","DOIUrl":"https://doi.org/10.1080/23802693.2016.1246278","url":null,"abstract":"Abstract Titanium alloy (Ti–6Al–4V) is a subject of this research because it has high strength and oxidation resistance in a wide range of temperature. As a result of its resistance to high-temperature corrosion, the alloy is used for catalyst-grid. In the present study, full penetration welding of 1 mm thick titanium alloy sheet in a butt configuration was carried out by using an Nd-YAG laser welding machine. The influence of different welding, parameters, such as, welding speed, welding power on the heat affected zone (HAZ) morphology, metallurgy and mechanical properties, has been discussed in detail. Microstructures have been assessed by optical microscopy and by field emission scanning electron microscope (FESEM). The mechanical behavior has been analyzed in terms of Vickers micro-hardness compared with specimens under different welding conditions and base materials. A microstructure with different welding parameters has been scrutinized by FESEM. Hardness of the base metal has been found to be lower in comparison with the fusion zone due to rapid cooling. The weld size has been found to increase with a decreasing welding speed and decrease with an increasing welding speed. The hardness spreads from the parent metal to the HAZ and it is the maximum at the center of the weld region. It has been found that tensile strength of the specimen with different process parameters is approximately equal to the tensile strength of the parent metal.","PeriodicalId":414255,"journal":{"name":"Natural Resources & Engineering","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124874811","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solvent-free benzyl alcohol oxidation reaction over Sm-CeO2 supported gold nanoparticle using tert-butyl hydroperoxide (TBHP) as an oxidant","authors":"S. Mandal, Biswajit Chowdhury","doi":"10.1080/23802693.2016.1215630","DOIUrl":"https://doi.org/10.1080/23802693.2016.1215630","url":null,"abstract":"Abstract In this work, liquid phase oxidation of benzyl alcohol under solvent-free condition is carried out using tert-butyl hydroperoxide (TBHP) as an oxidant over CeO2, Sm-CeO2, Au/CeO2, and Au/Sm-CeO2 catalysts. The Au/Sm-CeO2 catalyst shows higher activity compared to Au/CeO2 catalyst but in every case, almost 100% selectivity of benzaldehyde is observed. From CO2-temperature programmed desorption results, it is observed that the amount of basic sites increase after samarium doping and these basic sites play a crucial role for benzyl alcohol oxidation reaction. From these above experimental results, superior catalytic activity was observed for 2.33 wt% Au/Sm-CeO2 catalyst (Sm/Ce = 4/100).","PeriodicalId":414255,"journal":{"name":"Natural Resources & Engineering","volume":"62 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123918066","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Physicochemical properties of three typical purple soils with different parent materials and land uses in Sichuan Basin, China","authors":"Yi Xiao, Jia-liang Tang, Ming Kuang Wang","doi":"10.1080/23802693.2016.1258854","DOIUrl":"https://doi.org/10.1080/23802693.2016.1258854","url":null,"abstract":"Abstract Mainly located in the Sichuan Basin, known as the ‘Land of Plenty’, purple soils (developed from purple sandstone and shale) have been long noted as highly productive in spite of their rocky texture. However, information on the physicochemical properties (including mineral properties) of purple soils remained obscure for the scientific community. For example, it is not clear what causes the purple color of the soils. In this study, eight soil profiles of the Jiufeng (JF, acidic), Shibao (SB, neutral), and Yanting (YT, calcareous) areas, representing the three most widely distributed purple soils in Sichuan Basin, were individually sampled under both cropland and forestland, and then analyzed using common chemical analysis and conventional X-ray diffraction to clarify the effects of clay mineral and anthropogenic influences on the typical soils. The results show that considerable variability of soil pH and cation-exchange capacity (CEC) exists between soil types (p < 0.05). Organic matter, total nitrogen, and CEC of forestland are higher than those of farmland, while farmland has a higher content of Olsen-P, indicating significant farming effects on nutrient status. Acidic and neutral purple soils had higher total P contents than calcareous soils while calcareous soils had higher TN, clay, and CaCO3 contents. OM, TN, TP, and Olsen-P decreased with soil depth both in farmland and forestland soil profiles. Vertical distribution of organic-bound Fe-oxides (Fep) and clay particles also shows the anthropogenic interference on farmland. Illite, chlorite, kaolinite, goethite, and trace amounts of an illite–chlorite mixing layer in clay fractions were identified for typical purple soils. Hematite was observed in the coarser fractions of the calcareous pedons, confirming that the purple soil color was mainly derived from the parent rocks. Understanding of the physicochemical properties and mineral species of soil profiles can shed light on the sustainable uses of typical purple soils in subtropical area.","PeriodicalId":414255,"journal":{"name":"Natural Resources & Engineering","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122385255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bioremediation of hexavalent and trivalent chromium using Citrobacter freundii: a mechanistic study","authors":"D. Prabhakaran, J. Riotte, S. Subramanian","doi":"10.1080/23802693.2016.1215880","DOIUrl":"https://doi.org/10.1080/23802693.2016.1215880","url":null,"abstract":"Abstract The mechanisms involved in the bioremediation of hexavalent chromium (Cr(VI)) and trivalent chromium (Cr(III)) by a Gram negative bacterium, Citrobacter freundii were independently investigated. The biosorption isotherms of Cr(VI) and Cr(III) for C. freundii exhibited a typical Langmuirian behaviour. The Gibbs free energy (ΔG) was determined to be -25.5 and −27.2 kJ mol−1, respectively for Cr(VI) and Cr(III), suggestive of chemisorption between the functional groups of bacterial surface and Cr. The relatively lesser amount of desorption of Cr(VI) or Cr(III) from the bacterial cells attested to the irreversible nature of biosorption. FTIR studies revealed the involvement of carboxyl, amino and hydroxyl groups in the biosorption of Cr(VI) and Cr(III). X-ray photoelectron spectroscopic studies provided evidence in support of the bioreduction from Cr(VI) to Cr(III). Electrokinetic studies revealed that the bacterial cells become less electronegative after interaction with Cr species. The mechanisms of bioremediation have been delineated to involve both biosorption and bioreduction processes for Cr(VI), while for Cr(III), biosorption is the governing process of remediation.","PeriodicalId":414255,"journal":{"name":"Natural Resources & Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129593479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synthesis and characterization of proton exchange membrane employing waste polystyrene as precursor","authors":"Sharon Ng Kar Mei, Y. Kang, A. Rosdi, Saravanan Pichiah, S. Ibrahim","doi":"10.1080/23802693.2016.1242226","DOIUrl":"https://doi.org/10.1080/23802693.2016.1242226","url":null,"abstract":"Abstract In the present work, waste polystyrene was successfully applied as a precursor for the synthesis of proton exchange membrane (PEM). The study also examined the membrane characteristics before and after sulfonation and the latter reaction was facilitated with the aid of acetyl sulfate. The obtained membranes were characterized for its inherent nature. The functional group analysis of the raw precursor clearly discloses the presence of sulfonic groups in the raw precursor and increase in sulfonic groups were observed for the sulfonated samples. The thermogravimetric results revealed that the raw precursor and the sulfonated membrane (SM) exhibited almost similar thermal stability. The sulfonation contributed for better water uptake and is further proven by ion exchange capacity and proton conductivity analysis where SM achieved higher IEC and proton conductivity. The IEC increased from 0.105 to 0.536 meq/L and from 4.357 × 10−7 to 1.327 × 10−6 S/cm for proton conductivity. Thus, the study has proven the viability of waste plastics as a precursor for the synthesis of PEMs.","PeriodicalId":414255,"journal":{"name":"Natural Resources & Engineering","volume":"192 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129269426","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}