Optimization and prediction of CBN tool life sustainability during AA1100 CNC turning by response surface methodology.

The aluminium alloy (AA1100) was familiar with automotive flexible shaft coupling applications due to its high strength, good machinability, and superior thermal and resistance to corrosion characteristics. Machining tool life drives the prominent role for deciding the product quality (machining) act aims to productivity target with zero interruptions. The novelty of this present investigation is the focus on increasing tool life during the complexity of CNC turning operation for AA1100 alloy by using CBN coated insert tool with varied input parameters of spindle speed (SS), feed rate (f), and depth of cut (DOC). Design of experiment (L16), analysis of variance (ANOVA) statistical system adopted with response surface methodology (RSM) is implemented for experimental analysis. The turning input parameters of SS, f and DOC are considered as factors and its SS (900, 1100, 1300, and 1500 rpm), f (0.1, 0.15, 0.2, and 0.25), and DOC (0.1, 0.2, 0.3, and 0.4 mm) values are treated as levels. The investigational analysis was made with the ANOVA technique and the desirability of high tool life with input turning parameters was optimized by RSM, and sample no 11/16 was predicted as high tool life and performed with extended working hours compared to other samples. The RSM optimized best turning parameter combinations are 0.1 mm DOC, 0.2mm/rev to 0.25mm/rev f, and 1300 rpm-1500 rpm SS, facilitating a higher tool life of more than 20min.

Effect of fiber layer formation on mechanical and wear properties of natural fiber filled epoxy hybrid composites.

Natural fiber-reinforced polymer matrix composites are gathering significance in future trend applications such as automotive, aerospace, sport, and other engineering applications due to their superior enhanced mechanical, wear, and thermal properties. Compared to synthetic fiber, natural fiber is low adhesive and flexural strength properties. The research aims to synthesize the epoxy hybrid composites by utilizing the silane (pH = 4) treated Kenaf (KF) and sisal fiber (SF) as layering by uni, bi, and multi-unidirectional via hand layup techniques. Thirteen composite samples have been prepared by three-layer formation adopted with different weight ratios of E/KF/SF such as 100E/0KF/0SF, 70E/30KF/0SF, 70E/0KF/30SF, 70E/20KF/10SF, and 70E/10KF/20SF respectively. The effect of layer formation on the tensile, flexural, and impact strength of composites is studied by ASTM D638, D790, and D256 standards. The unidirectional fiber layer formed (sample 5) 70E/10KF/20SF composite is found maximum tensile and flexural strength of 57.9 ± 1.2 MPa and 78.65 ± 1.8 MPa. This composite is subjected to wear studies by pin-on-disc wear apparatus configured with a hardened grey cast-iron plate under an applied load of 10, 20, 30, and 40 N at different sliding velocities of 0.1, 0.3, 0.5, and 0.7 m/s. The wear rate of the sample progressively increases with increasing load and sliding speed of the composite. The minimum wear rate of 0.012 mg/min (sample 4) is found on 7.6 N frictional force at 0.1 m/s sliding speed. Moreover, sample 4 at a high velocity of 0.7 m/s with a low load (10 N) shows a wear rate of 0.034 mg/min. The wear-worn surface is examined and found adhesive and abrasive wear on a high frictional force of 18.54 N at 0.7 m/s. The enhanced mechanical and wear behavior of sample 5 is recommended for automotive seat frame applications.

Comparison of bacterial diversity in proglacial soil from Kafni Glacier, Himalayan Mountain ranges, India, with the bacterial diversity of other glaciers in the world.

Two 16S rRNA gene clone libraries (KF and KS) were constructed using two soil samples (K7s and K8s) collected near Kafni Glacier, Himalayas. The two libraries yielded a total of 648 clones. Phyla Actinobacteria, Bacteroidetes, Chloroflexi Firmicutes, Proteobacteria, Spirochaetae, Tenericutes and Verrucomicrobia were common to the two libraries. Phyla Acidobacteria, Chlamydiae and Nitrospirae were present only in KF library, whereas Lentisphaerae and TM7 were detected only in KS. In the two libraries, clones belonging to phyla Bacteroidetes and Proteobacteria were the most predominant. Principal component analysis (PCA) revealed that KF and KS were different and arsenic content influenced the differences in the percentage of OTUs. PCA indicated that high water content in the K8s sample results in high total bacterial count. PCA also indicated that bacterial diversity of KF and KS was similar to soils from the Pindari Glacier, Himalayas; Samoylov Island, Siberia; Schrimacher Oasis, Antarctica and Siberian tundra. The eleven bacterial strains isolated from the above two soil samples were phylogenetically related to six different genera. All the isolates were psychro-, halo- and alkalitolerant. Amylase, lipase and urease activities were detected in the majority of the strains. Long chain, saturated, unsaturated and branched fatty acids were predominant in the psychrotolerant bacteria.

Bacterial diversity of soil in the vicinity of Pindari glacier, Himalayan mountain ranges, India, using culturable bacteria and soil 16S rRNA gene clones.

Three 16S rRNA gene clone libraries (P1L, P4L and P8L) were constructed using three soil samples (P1S, P4S and P8S) collected near Pindari glacier, Himalayas. The three libraries yielded a total of 703 clones. Actinobacteria, Firmicutes and Proteobacteria were common to the three libraries. In addition to the above P1L and P8L shared the phyla Acidobacteria, Bacteroidetes, Gemmatimonadetes and Planctomycetes. Phyla Chlamydiae, Chlorobi, Chloroflexi, Dictyoglomi, Fibrobacteres, Nitrospirae, Verrucomicrobia, candidate division SPAM and candidate TM7s TM7a phylum were present only in P1L. Rarefaction analysis indicated that the bacterial diversity in P4S and P8S soil samples was representative of the sample. Principal component analysis (PCA) revealed that P1S and P8S were different from P4S soil sample. PCA also indicated that arsenic content, pH, Cr and altitude influence the observed differences in the percentage of specific OTUs in the three 16S rRNA gene clone libraries. The observed bacterial diversity was similar to that observed for other Himalayan and non-polar cold habitats. A total of 40 strains of bacteria were isolated from the above three soil samples and based on the morphology 20 bacterial strains were selected for further characterization. The 20 bacteria belonged to 12 different genera. All the isolates were psychro-, halo- and alkalitolerant. Amylase and urease activities were detected in majority of the strains but lipase and protease activities were not detected. Long chain, saturated, unsaturated and branched fatty acids were predominant in the psychrotolerant bacteria.

Leifsonia pindariensis sp. nov., isolated from the Pindari glacier of the Indian Himalayas, and emended description of the genus Leifsonia.

Strain PON10(T) is a yellow-pigmented, Gram-positive, aerobic, motile, rod-shaped bacterium isolated from the Pindari glacier of the Indian Himalayas. The cell-wall peptidoglycan contained DL-diaminobutyric acid as the diamino acid. The predominant fatty acids were anteiso-C(15:0), anteiso-C(17:0) and iso-C(16:0) and the major isoprenoid quinones were MK-10 and MK-11. Based on the above characteristics, strain PON10(T) was assigned to the genus Leifsonia. blast sequence similarity results indicated that Leifsonia ginsengi and Leifsonia poae were the nearest relatives, with 16S rRNA gene sequence similarity of 97.0 and 96.8% to the respective type strains. A difference of 3% in the 16S rRNA gene sequence indicated that PON10(T) represents a novel species of the genus Leifsonia, and therefore DNA-DNA hybridization was not done. In addition, PON10(T) showed a number of differences from Leifsonia ginsengi and Leifsonia poae with respect to phenotypic and chemotaxonomic characteristics. Thus, based on the differences it exhibited from Leifsonia ginsengi and Leifsonia poae, strain PON10(T) was identified as representing a novel species named Leifsonia pindariensis sp. nov. The type strain is PON10(T) (=LMG 24222(T) =MTCC9128(T)). An emended description of the genus Leifsonia is also presented.

Hexachlorocyclohexane-degrading bacterial strains Sphingomonas paucimobilis B90A, UT26 and Sp+, having similar lin genes, represent three distinct species, Sphingobium indicum sp. nov., Sphingobium japonicum sp. nov. and Sphingobium francense sp. nov., and reclassification of [Sphingomonas] chungbukensis as Sphingobium chungbukense comb. nov.

Three strains of Sphingomonas paucimobilis, B90A, UT26 and Sp+, isolated from different geographical locations, were found to degrade hexachlorocyclohexane. Phylogenetic analysis based on 16S rRNA gene sequences indicated that these strains do not fall in a clade that includes the type strain, Sphingomonas paucimobilis ATCC 29837(T), but form a coherent cluster with [Sphingomonas] chungbukensis IMSNU 11152(T) followed by Sphingobium chlorophenolicum ATCC 33790(T). The three strains showed low DNA-DNA relatedness values with Sphingomonas paucimobilis ATCC 29837(T) (8-25%), [Sphingomonas] chungbukensis IMSNU 11152(T) (10-17%), Sphingobium chlorophenolicum ATCC 33790(T) (23-54%) and Sphingomonas xenophaga DSM 6383(T) (10-28%), indicating that they do not belong to any of these species. Although the three strains were found to be closely related to each other based on 16S rRNA gene sequence similarity (99.1-99.4%), DNA-DNA relatedness (19-59%) and pulsed-field gel electrophoresis (PFGE) patterns indicated that they possibly represent three novel species of the genus Sphingobium. The three strains could also be readily distinguished by biochemical tests. The three strains showed similar polar lipid profiles and contained sphingoglycolipids. The strains differed from each other in fatty acid composition but contained the predominant fatty acids characteristic of other Sphingobium species. A phylogenetic study based on 16S rRNA gene sequences showed that [Sphingomonas] chungbukensis IMSNU 11152(T) formed a cluster with members of the genus Sphingobium. Based on these results, it is proposed that strains B90A, UT26 and Sp+, previously known as Sphingomonas paucimobilis, are the type strains of Sphingobium indicum sp. nov. (=MTCC 6364(T)=CCM 7286(T)), Sphingobium japonicum sp. nov. (=MTCC 6362(T)=CCM 7287(T)) and Sphingobium francense sp. nov. (=MTCC 6363(T)=CCM 7288(T)), respectively. It is also proposed that [Sphingomonas] chungbukensis be transferred to Sphingobium chungbukense comb. nov.

Marinomonas ushuaiensis sp. nov., isolated from coastal sea water in Ushuaia, Argentina, sub-Antarctica.

A Gram-negative, rod-shaped, psychrophilic, motile, non-spore-forming bacterium, strain U1T, was isolated from Ushuaia located at the southernmost tip of Argentina. On the basis of 16S rRNA gene sequence similarity, strain U1T was found to be closely related to Marinomonas communis (DSM 5604T) and Marinomonas primoryensis (IAM 15010T). At the DNA-DNA level, however, the values for similarity were 41 and 25 %, respectively. The major fatty acids present were iso-C(16 : 0), C(16 : 1)omega7c, iso-C(17 : 1) and C(18 : 1)omega7c and the G+C content of the DNA was 43.6 mol%. All of the above characteristics support the affiliation of strain U1T to the genus Marinomonas. Furthermore, on the basis of phenotypic features, chemotaxonomic characteristics and phylogenetic analysis of the 16S rRNA gene sequence, it appears that strain U1T is distinct from the four Marinomonas species with validly published names. Strain U1T, therefore, represents a novel species, for which the name Marinomonas ushuaiensis sp. nov. is proposed. The type strain of M. ushuaiensis is U1T (=MTCC 6143T=DSM 15871T=JCM 12170T).

Reclassification of Amycolatopsis mediterranei DSM 46095 as Amycolatopsis rifamycinica sp. nov.

Previous experiments have suggested that the rifamycin-producing strain DSM 46095 might not belong to Amycolatopsis mediterranei. Analysis of its 16S rRNA gene sequence and construction of a phylogenetic tree showed most similarity to Amycolatopsis kentuckyensis NRRL B-24129T, Amycolatopsis lexingtonensis NRRL B-24129T and Amycolatopsis pretoriensis NRRL B-24133T, but the strain was probably not a member of any of these species. Results from DNA-DNA hybridization experiments and comparison of DNA profiling patterns using pulsed-field gel electrophoresis also supported the assignment of strain DSM 46095 to a novel species. Analyses of phospholipids, fatty acid methyl esters and physiological characteristics also showed that the differences between different isolates of A. mediterranei and A. mediterranei DSM 46095 were as large as those between Amycolatopsis species. Strain DSM 46095 represents a novel species of the genus Amycolatopsis for which the name Amycolatopsis rifamycinica sp. nov. is proposed, with the type strain NT 19T (=DSM 46095T=ATCC 27643T).

Bacillus indicus sp. nov., an arsenic-resistant bacterium isolated from an aquifer in West Bengal, India.

Strain Sd/3T (=MTCC 4374T=DSM 15820T), an arsenic-resistant bacterium, was isolated from a sand sample obtained from an arsenic-contaminated aquifer in Chakdah district in West Bengal, India (23 degrees 3' N 88 degrees 35' E). The bacterium was Gram-positive, rod-shaped, non-motile, endospore-forming and yellowish-orange pigmented. It possessed all the characteristics that conform to the genus Bacillus, such as it had A4beta murein type (L-orn-D-Asp) peptidoglycan variant, MK-7 as the major menaquinone and iso-C15 : 0 and anteiso-C15 : 0 as the major fatty acids. Based on its chemotaxonomic and phylogenetic characteristics, strain Sd/3T was identified as a species of the genus Bacillus. It exhibited maximum similarity (95%) at the 16S rRNA gene level with Bacillus cohnii; however, DNA-DNA similarity with B. cohnii was 60.7%. Strain Sd/3T also exhibited a number of phenotypic differences from B. cohnii (DSM 6307T). These data suggest that Sd/3T represents a novel species of the genus Bacillus. The name Bacillus indicus sp. nov. is proposed.

Phenotypic and genetic diversity of Bacillus thuringiensis strains isolated in India active against Spodoptera litura.

Bacillus thuringiensis strains isolated from different agroclimatic regions of India were found to harbor cry1 family genes. Of 831 strains 18 that were found to produce 130- and 68-kDa mol wt proteins in sodium dodecyl sulfate polyacry1amide gel electrophoresis were subjected to bioassay against second instar larvae of Spodoptera litura. According to the time response curve, while the highest toxic activity against S. litura was observed in PBT-782 with an LT50 of 25.46 h, strains PBT-372, PBT-574, PBT-801, and PBT-716 in descending order of merit had LT50 values of 36.81, 48.18, 50.35, and 73.53 h. The results of the field experiment testing the efficacy of different B. thuringiensis strains in controlling S. litura larvae infecting peanut plants showed that the chemical insecticide chlorpyriphos was the most effective in controlling S. litura throughout the study period. However, among B. thuringiensis strains, PBT-372 was superior. All the B. thuringiensis strains except PBT-689 were found to contain cry1Ac1-type gene. However, only nine strains contained cry1Aa1 gene. While cry1Ab1 was present only in PBT-372 and PBT-689, cry1Ca1 was present in PBT-574, PBT-688, PBT-689, and PBT-695. cry1Da1 was detected only in PBT-688 and PBT-692. None of the strains contained cry1Ba1 and cry1Ea1 genes. When polymerase chain reaction analysis using cry1Ca1 primer was performed, PBT-695 produced an unexpected 739-bp product, which showed 33% homology with cry1Ca1 gene between nucleotides 1819 and 2107. Our results indicated that among the field-collected B. thuringiensis strains, PBT-372 harbors multiple cry-type genes and could be employed for biological control of insects.