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This Unquestionably, Internet of Things (IoT) stands as a novel and more prominent internet based communicating architecture for future applications includes smart cities, smart transportations, smart grid etc. However the most concentrated and research aspect of IoT is security provision to the devices connected and the data transmitting through it. Since the devices communicate through internet in IoT, there exist number of adversaries/ attacks which tries to compromise the network. Herein this leads into the loss of confidentiality, integrity, availability and trust of the devices and network resources. This paper presents a brief survey on the possible attacks happening in different layers of IoT and also presents the possible mitigation schemes to reduce the effect of attacks.

Woven fabric-reinforced polymer composites are widely used in the structural applications like aircraft, automotive, marine and machine tool structures due to their excellent integrity, conformability and balanced mechanical properties within the fabric plane. It is observed that the structural members used in such applications experiencing vibration and considerable cyclic loading in operations are inevitable in dynamic conditions. Therefore, the study of the interaction of vibration characteristics of composite structures due to the fatigue loading needs much attention to meet the industrial requirements. In this study, the interaction of fatigue loading and vibration characteristics of epoxy-based glass/carbon hybrid beams was evaluated by measuring the variation in the modal stiffness. The two types of hybrid layer arrangements using glass and carbon woven fabrics, GCCG and CGGC, are preferred for the present investigation, by considering the balanced modulus property in longitudinal and transverse direction of the specimens. A displacement-controlled fully reversed flexural fatigue testing rig was designed and developed with required control circuits and test specimens to find the interaction of flexural fatigue loading on vibration characteristics of fibre-reinforced composite beams. The vibration characteristics and interaction of fatigue loading on vibration characteristics of thin-walled woven fabric glass/carbon hybrid composite beams made of different stacking sequences for promoting good dynamic stability were investigated.

Highly oriented thin films of Al doped ZnO (Al:ZnO) and Cu co-doped Al:ZnO (Cu/Al:ZnO) thin films were successfully deposited by sol–gel spin coating on glass substrates. The deposited films were characterized using X-ray diffraction analysis and found to exhibit hexagonal wurtzite structure with c-axis orientation. SEM images revealed that hexagonal rod shaped morphologies were grown perpendicular to the substrate surface due to repeated deposition process. High transmittance values were observed for pure ZnO compared to Al:ZnO and Cu/Al:ZnO thin films. The band gap widening is caused by the increase of carrier concentration, which is believed to be due to Burstein-Moss effect due to Al and Cu doping. PL spectra of Cu/Al:ZnO thin films indicate that the UV emission peaks slightly shifted towards lower energy side. XPS study was carried out for Zn0.80Al0.10Cu0.10O thin films to analyze the binding energy of Al, Cu, Zn and O. Magnetic measurement studies exhibited ferromagnetic behavior at room temperature, which may be due to the increase in copper concentration in the doped films. The ferromagnetic behavior can be understood from the exchange coupling between localized ‘d’ spin of Cu ion mediated by free delocalized carriers.

In this investigation, CeO2 thin films were deposited on glass substrates with different substrate temperatures by using RF Magnetron sputtering technique. The deposited films were characterized by X-ray diffraction (XRD), UV–visible spectroscopy, room temperature photoluminescence spectroscopy, micro-Raman and X-ray photoelectron spectroscopy. The thicknesses of the film were determined by using profilometer and it was varied from 0.70 μm to 0.87 μm. From the XRD results, it is evident that the film deposited at room temperature (RT) is amorphous in nature. The remarkable change in character from amorphous to crystalline is observed by increasing the substrate temperature from RT to 300 °C, and the crystallites were found to be in cubic phase with preferred orientation along (2 2 0). Calculated crystallite sizes were in the range of ∼8.6 nm. Optical characteristics were studied as a function of change in substrate temperature and thickness in air. Overall transmittance percentages of the films (85–60%) were found to decrease with increase in substrate temperatures. The results show that the energy band gap was found to be decreased (3.95–3.75 eV) with the increase of substrate temperature as well as thickness of the film. Optical constants like refractive index (n), extinction coefficient (k), optical conductivity (σ), real and imaginary part of dielectric constant (e1 & e2), volume energy loss function (VELF) and surface energy loss function (SELF) were evaluated by using UV spectra. It is found from PL spectra that the decreased defects for the films prepared at a higher substrate temperature. A strong near band edge emission and weak green emission were observed at ∼360 and ∼519 nm respectively. The micro-Raman results show the characteristic peak of CeO2 F2g at ∼465 cm−1. It is found from the spectrum that the peak intensity of the films increased with increase in substrate temperature. XPS analysis confirms the highly non-stoichiometric nature of the films with dominant occurrence of Ce4+ (CeO2) and subsidiary occurrence of Ce3+ (Ce2O3).

Trivalent neodymium doped ZnO (Zn1−xNdxO, x = 0.0, 0.03, 0.06 and 0.09) nanoparticles (NPs) synthesized by co-precipitation method with improved optical and antibacterial performance is reported. X-ray diffraction pattern indicates most of Nd3+ ions are incorporated in Zn2+ ions of ZnO lattice and hence there is no secondary peak of NdO3 in synthesized ZnO NPs. Fourier transform infrared spectroscopy analysis of synthesized NPs exhibits similar patterns in Zn/Nd–O bands observed at 480 cm−1. High resolution scanning electron microscopy images revealed the formation of spindle like morphology and the incorporation of Nd ions is confirmed by energy dispersive spectra analysis. UV–visible absorption spectra of pure and Nd doped ZnO NPs showed the variation of the band gap in the range of 3.06–2.65 eV. Raman analysis confirmed the formation of wurtzite structure of NPs was distorted due to Nd substitution in ZnO matrix. X-ray photoelectron spectroscopy confirmed the Nd incorporation in the ZnO lattice as Nd3+. The prepared Nd doped ZnO NPs showed potential application in antibacterial activities.

In this paper, we report the structural, optical and magnetic properties of nano crystalline samples of Zn1−x(TM)xO (TM = Ni, Co and x = 0, 0.05, 0.10 and 0.15) synthesized by co-precipitation method. The synthesized samples were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), photoluminescence (PL), micro-Raman, and vibrating sample magnetometer (VSM). It is observed from XRD patterns that all the samples reveal polycrystalline hexagonal wurtzite structure without any extra phase and average particle size decreased with increasing transition metal (TM) doping concentration. FTIR spectrum has been used to confirm the functional group of Ni–O and Co–O bond. SEM images demonstrated the grain like morphologies of TM doped ZnO nanoparticles (NPs). PL spectra of all samples exhibited a broad emission in the visible range. The carriers (donors) bounded on the TM sites were observed from the micro Raman spectroscopic studies. TM doped ZnO NPs showed significant changes in the M–H loop where the diamagnetic behavior of ZnO changes to ferromagnetic nature when doping with Ni and Co ions.

DD-carboxypeptidases (DD-CPases) are low-molecular-mass (LMM) penicillin-binding proteins (PBPs) that are mainly involved in peptidoglycan remodelling, but little is known about the dd-CPases of mycobacteria. In this study, a putative DD-CPase of Mycobacterium smegmatis, MSMEG_2433 is characterized. The gene for the membrane-bound form of MSMEG_2433 was cloned and expressed in Escherichia coli in its active form, as revealed by its ability to bind to the Bocillin-FL (fluorescent penicillin). Interestingly, in vivo expression of MSMEG_2433 could restore the cell shape oddities of the septuple PBP mutant of E. coli, which was a prominent physiological characteristic of DD-CPases. Moreover, expression of MSMEG_2433 in trans elevated beta-lactam resistance in PBP deletion mutants (ΔdacAdacC) of E. coli, strengthening its physiology as a dd-CPase. To confirm the biochemical reason behind such physiological behaviours, a soluble form of MSMEG_2433 (sMSMEG_2433) was created, expressed and purified. In agreement with the observed physiological phenomena, sMSMEG_2433 exhibited DD-CPase activity against artificial and peptidoglycan-mimetic DD-CPase substrates. To our surprise, enzymic analyses of MSMEG_2433 revealed efficient deacylation for beta-lactam substrates at physiological pH, which is a unique characteristic of beta-lactamases. In addition to the MSMEG_2433 active site that favours dd-CPase activity, in silico analyses also predicted the presence of an omega-loop-like region in MSMEG_2433, which is an important determinant of its beta-lactamase activity. Based on the in vitro, in vivo and in silico studies, we conclude that MSMEG_2433 is a dual enzyme, possessing both DD-CPase and beta-lactamase activities.

Pure and Zn1−xCoxO (x = 0.05, 0.10 and 0.15) nanoparticles were synthesized by co-precipitation method. Powder X-ray diffraction studies confirmed that pure and Co doped ZnO have a single phase nature with hexagonal wurtzite structure and Co2+ ions were successfully incorporated into the lattice position of Zn2+ ions in ZnO matrix. FTIR and EDS spectra results confirmed the incorporation of the dopants into the ZnO lattice structure. FESEM images showed the flower like morphology in ZnO and flowers are dispersed to grains in Co doped ZnO nanoparticles. The chemical composition of Zn0.90Co0.10O nanoparticles were confirmed by XPS. The XPS results clearly showed the existence of Co as a doping element into the ZnO crystalline lattice. Further, the synthesized Co doped ZnO nanoparticles have been used for electrochemical non-enzymatic glucose biosensing. The lowest detection limit of the proposed sensor was found to be 5 µM. The sensor selectively oxidizes glucose in the presence of other interfering compounds like l-dopa, ascorbic acid, hydrogen peroxide and uric acid.

Cerium oxide (CeO2) thin films were prepared by rf magnetron sputtering (PVD) technique onto glass substrates at a pressure of 3 × 10−4 mbar of Ar+ atmosphere. The thickness of deposited CeO2 films ranges from 380 to 590 nm. X-ray diffraction studies on the films showed that the films are polycrystalline in nature. The crystallite size (D), dislocation density (δ) and micro-strain (e) were evaluated from XRD patterns. The obtained micro-strain and dislocation density of the films were found to be ~10−3 and ~1016 lines/m2 respectively, along with a marginal increase in crystallite size from ~6 to ~9 nm. The experimental diffraction values of the films agreed with the standard values. The optical properties of cerium oxide films were studied in the wavelength range 325–900 nm. Optical absorption, extinction coefficients, refractive index and optical conductivity were evaluated from optical measurements. The films are found to be highly transparent in visible region and exhibits low reflectance in the ultraviolet region. The optical band gap of the films was found to decrease from 3.53 to 3.45 eV, with the increase of film thickness. The defects were found to increase with the increase of rf power. Emission bands like UV, weak blue, blue, blue–green and green bands were observed from PL spectra of CeO2 thin films. Raman active mode (F2g) of CeO2 thin films was observed at 466 cm−1 and films deposited at higher rf power show increased line width as well as peak intensity in Raman spectra. Rf power induced formations of flower like morphology were observed in SEM images. The surface roughness of CeO2 thin films was increased from 2.9 to 7.7 nm with the increase of rf power as ascertained from AFM images and the results are discussed.

We show that nucleosomes can efficiently control the relative search times spent by transcription factors (TFs) on one- (1D) and three-dimensional (3D) diffusion routes towards locating their cognate sites on DNA. Our theoretical results suggest that the roadblock effects of nucleosomes are dependent on the relative position on DNA with respect to TFs and their cognate sites. Especially, nucleosomes exert maximum amount of hindrance to the 1D diffusion dynamics of TFs when they are positioned in between TFs and their cognate sites. The effective 1D diffusion coefficient (χTF) associated with the dynamics of TFs in the presence of nucleosome decreases with the free energy barrier (µ) associated the sliding dynamics of nucleosomes as . Subsequently the mean first passage time (ηL) that is required by TFs to scan L number of binding sites on DNA via 1D diffusion increases with μ as . When TFs move close to nucleosomes then they exhibit a typical sub-diffusive dynamics. Nucleosomes can enhance the search dynamics of TFs when TFs present in between nucleosomes and transcription factor binding sites (TFBS). The level of enhancement effects of nucleosomes seems to be much lesser than the level of retardation effects when nucleosomes present in between TFs and their cognate sites. These results suggest that nucleosome depleted regions around the cognate sites of TFs is mandatory for an efficient site-specific interactions of TFs with DNA. Remarkably the genome wide positioning pattern of TFs shows maximum at their specific binding sites and the positioning pattern of nucleosome shows minimum at the specific binding sites of TFs under in vivo conditions. This seems to be a consequence of increasing level of breathing dynamics of nucleosome cores and decreasing levels of fluctuations in the DNA binding domains of TFs as they move across TFBS. Since the extent of breathing dynamics of nucleosomes and fluctuations in the DBDs of TFs are directly linked with their respective 1D diffusion coefficients, the dynamics of TFs becomes slow as they approach their cognate sites so that TFs form tight site-specific complex. Whereas the dynamics of nucleosomes becomes rapid so that they pass through the cognate sites of TFs. Several in vivo datasets on genome wide positioning pattern of nucleosomes as well as TFs seem to agree well with our arguments. We further show that the condensed conformational state of DNA can significantly decrease the retarding effects of nucleosome roadblocks. The retarding effects of nucleosomes on the 1D diffusion dynamics of TFs can be nullified when the degree of condensation of the genomic DNA is such that it can permit a jump size associated with the dynamics of TFs beyond k > 150 bps.

This chapter covers the synthesis of heterocyclic compounds using heterogeneous catalysts from the perspective of practicing industrial chemists. Before discussing the synthesis of various heterocycles using heterogeneous catalysts a brief discussion on catalyst choice and classification of reaction chemistry is provided. Next, the synthesis of commercially important heterocycles from acyclic precursors is provided starting with the three-membered aziridines and epoxides. For the four-membered heterocycles, propiolactone synthesis is discussed followed by the five-membered pyrroles, furans, and thiophenes. Within the five-membered ring category of heterocycles, the benz-fused pyrrole, indole and rings with more than one heteroatom such as pyrazoles, imidazoles, thiazoles, oxa- and thio-diazoles synthesis are also discussed. Similar to the five-membered ring heterocycles, the six-membered heterocycle syntheses discussed are pyridines, picolines, quinolines, acridines, pyrimidines, pyrazines, triazines, coumarins, etc. Finally a small section on process and economics consideration is provided along with final comments.

One of the major concerns challenging today's textile sector is related to the environment. The clothing and textile industries are under pressure to reduce discharge in solid, liquid and volatile forms. In this regard, new approaches toward producing environmentally friendly products or processes which are recyclable and biodegradable are gaining interest. Owing to this environmental concern, industries are increasingly focused on addressing greenhouse gas emissions throughout the product or process value chain from raw material extraction to disposal, as a complement to company-specific carbon footprinting. Denim, which is one of the mostly consumed and fashionable clothing in the world, is also analyzed because of its environmental concerns. This chapter provides detailed information about the carbon footprint in every stage of denim manufacturing, starting from raw material to finishing and washing, further transportation and the consumer use phase. Furthermore, eco-friendly processes as well as strategies to reduce the carbon footprint in denim manufacturing are briefly discussed.

Pure and transition metal (TM = Ni, Mn, Co) doped zinc oxide (ZnO) thin films were prepared by sol–gel spin coating method with a concentration of 0.03 mol% of transition metals. X-ray diffraction studies revealed the polycrystalline nature of the films with the presence of hexagonal wurtzite structure. UV transmittance spectra showed that all the films are highly transparent in the visible region and in the case of doped ZnO thin films, d–d transition was observed in the violet region due to the existence of crystalline defects and grain boundaries. The optical band gap of the films decreases with increasing orbital occupation numbers of 3d electrons due to the orbital splitting of magnetic ions. Ultraviolet and near-infrared electronic transitions were observed which reveals a strong relationship with the doping of transition metal into ZnO site. The observed luminescence in the green, violet and red regions strongly depends on the doping elements owing to the different oxygen vacancy, oxygen interstitial, and surface morphology. The surface morphology of thin films was investigated by scanning electron microscope (SEM). The energy dispersive X-ray analysis (EDX) confirmed the stoichiometric composition of the TM doped ZnO thin films. Magnetic measurements at room temperature exhibited well defined ferromagnetic features of the thin films.

We report a simple and efficient route to synthesize nanoarrows shaped zinc oxide (ZnO) combining electrospinning and high temperature calcination for photocatalytic applications. A comparison of the photo catalytic degradation of methyl orange with ZnO nanoparticles showed that the ZnO nanoarrows were superior to ZnO nanoparticles. These novel ZnO nanoarrows could have wide range of applications such as energy materials, gas sensors, UV–visible blockers and catalyst for organic synthesis.

Woven fabric reinforced polymeric composites are increasingly used in automotive and aircraft application in place of conventional metals due to their high specific strength. However in actual practice while using glass fabric layers, the large nominal size of the component was required and which facilitates increased total weight of the component. In the present investigation, glass laminate is modified and strengthened by interplying high modulus carbon fiber plies for attaining good strength to weight ratio. All laminates were fabricated using hand layup method. Mechanical properties such as tensile, flexural and impact strengths of dedicated and hybrid laminates were evaluated and reported.

Thermal zone was created at the spinning triangle of ring frame to produce 33/67 polyester-/cotton-blended yarns. The tenacity of modified yarn properties was compared with the yarn produced without thermal zone. Furthermore, to study the influence of gauge length in tenacity of these yarns, tests were conducted at various gauge lengths and Weibull plots were also obtained. Fibre failure at various gauge lengths was studied. The reliability analysis showed that the modified treble rove yarns are superior to the normal treble roves feed yarns.

In this study, Pergularia milkweed fibre (70%), cotton fibre (30%) core and 100% cotton fibre sheath DREF-3 core yarns of 74 tex were produced using different spinning parameters in order to understand their effect on yarn properties. Box–Behnken design was used for the optimization of core ratio, drum speed and suction pressure, and to evaluate the effects and interactions of the process variables on the yarn properties at a constant opening roller speed of 12,000 rpm and production speed of 100 m/min. The effects of the core/sheath ratio on all the yarn properties are significant. With an increase in the core/sheath ratio, yarn tenacity and elongation decrease due to insufficient wrapper fibres in the yarn and yarn unevenness; imperfection increases due to higher feed rate and draft at higher core ratio. The yarn hairiness increases at higher core ratio due to higher number of short fibres in milkweed and lesser sheath fibres to cover the core fibres effectively. An increase in the spinning drum speed d...

Polylinen® fabrics are obtained as a result of modification in the physical structure of polyester yarns to replicate the linen fabric. The scanning electron microscope analysis and Fourier transform infrared results reveal that the plasma treated fabric surface is effectively modified to enhance the wettability of the fabrics. In the present study, response surface methodology was employed to investigate the effects of different plasma treatment variables on the wetting behavior of polylinen fabrics. Box–Behnken design was used for the optimization of plasma treatment process and to evaluate the effects and interactions of the process variables, i.e. treatment time, power, and distance between the electrodes on the wettability of polylinen fabrics. The optimum conditions for maximum wicking height (4.3 cm) and spreading rate (86 s) of polylinen fabrics were established at 75 s treatment time, 460 watt power, and 2.5 cm distance between the electrodes. The plasma treated polylinen fabrics showed much bett...

We report the synthesis, characterization and photocatalytic application of ZnO–TiO 2 electrospun materials. Flower shaped ZnO–TiO 2 mesostructures were synthesized using an electrospinning technique, which is a well established and cost effective method for large scale production of 1-D nanomaterials. Calcination of the obtained electrospun ZnO–TiO 2 nanofiber membrane was done in a furnace at 500 °C. Photodegradation of alizarin red S (ARS) was examined individually using ZnO (NPs), TiO 2 (P25) and ZnO–TiO 2 flowers. A comparison of the photocatalytic performance of the material with TiO 2 (P25) and ZnO (NPs) showed that the nanoflower shaped structures were superior to commercially available P25 and ZnO (NPs). We expected that the material would have wide range of potential applications such as chemosensors, photonic crystals, UV–vis blockers, self-cleaning and organic synthesis.

A hitherto uninvestigated ligno-cellulosic seed fiber from the plant Pergularia Daemia has been chosen for the current study to unravel its physical properties, and potentialities in textile applications. The raw, NaOH treated, and wax removed fibers were tested for their morphological and structural features by X-ray diffraction, SEM, FT-IR spectra, and thermal analysis by thermogravimetry and differential scanning calorimetry. The raw fibers have low cellulose content and less crystalline compared to cotton and are having hollow, smooth surface, and less density. The brittle nature and low elongation at break of virgin fiber makes it difficult for the spinning. It becomes spinnable after NaOH treatment due to the increased elongation at break by partial removal of lignin.

Absence of any central co-ordination mechanism and shared wireless medium makes MANET more vulnerable to wide variety of attacks. In an internal attack, the attacker gains the normal access to the network and takes part in the network activities, either by some malicious impersonation to get the access to the network as a new node, or by directly compromising a current node and using it as a basis to conduct its malicious behaviors. In this paper, we developed an autonomous trust evaluation based cluster head misbehaviour detection and isolation in mobile ad hoc networks where the entire network is divided into hierarchical group of clusters, each cluster having a fully trusted Cluster Head (CH). As, CH, being an independent node that has mobility and autonomy behaviour, has the possibility that it may be vulnerable to DoS attacks. Hence, the assumption of CH being trusted cannot be considered. Therefore, ensuring the security of CH is essential which can be done by evaluating the trustworthiness of each CH. The trustworthiness of each CH is determined by its Group Leader (GL). In order to determine the cluster head and the group leader that are free from malicious attack, an autonomous trust evaluation is done for each CH to detect and isolate the misbehaving cluster head.

In this paper, we present the structural, morphological, optical and magnetic properties of Zn1−x A x O (A = Ni, Co and x = 0.20 mol%) and Zn0.80Ni0.10Co0.10O nanoparticles synthesized by a chemical co-precipitation method. Powder X-ray diffraction data confirm the formation of a single-phase wurtzite-type ZnO structure for all the samples. FTIR and EDS measurements ensure that the divalent Ni and Co ions are incorporated in the wurtzite host matrix without any impurity phase. Photoluminescence and Raman spectra indicate the presence of donor defects and oxygen vacancies in the prepared samples. In VSM analysis, undoped ZnO nanoparticles exhibit diamagnetic behavior at room temperature. A systematic increase in ferromagnetic moment (~0.70 emu/g) is observed for Ni-, Co-doped and Co co-doped Ni/ZnO at 300 K. The exchange interaction between delocalized carriers and the localized ‘d’ spins of Ni and Co ions is predicted as the cause of the room temperature ferromagnetism.

High quality Ni-doped CeO2 (CeO2:Ni) thin films were deposited on glass substrates at room temperature by using radio frequency magnetron sputtering. The effect of annealing temperature on structural and optical properties of the CeO2:Ni films was investigated. The structural, optical and vibrational properties of the films were determined using X-ray diffraction (XRD), photoluminescence spectrometer (PL) and Raman spectrometer. It was found that the as-deposited film has a fluorite cubic structure. By increasing annealing temperature from 100°C to 300°C, the crystalline quality of the thin films could be improved. The UV and visible band emissions were observed in the photoluminescence spectra, due to exciton, defect related emissions respectively. The micro-Raman results show the characteristic peak of CeO2 F2g at 465 cm−1 and 2L0 at 1142 cm−1. Defect peaks like D and 0 bands were observed at 641 cm−1 and 548 cm−1 respectively. It is found from the spectra that the peak intensity of the films increased ...

In this work, p-n hetrojunctions based on p-NiO and n-ZnO composite nanostructures were successfully deposited by sol-gel spin coating method. Structural investigations indicate well aligned ZnO nanorods with hexagonal faces having a preferential orientation along the c-axis (002). Scanning electron microscopy (SEM) was used to characterize, the p-n heterostructures formed grain like spherical structure of NiO fully covered the hexagonal rods of ZnO in the NiO/ZnO thin film and elements were confirmed from EDX analysis. PL and micro-Raman spectra of the deposited films showed the variation in luminescence and structural properties due to the formation of heterojuction of NiO.

We report systematic studies of the magnetic properties of Ni and Mn co-doped ZnO nanoparticles prepared by co-precipitation method. Structural characterization reveals that Ni and Mn ions substituted into ZnO lattices without any secondary phases formation. Photoluminescence and Raman spectra shows that the Ni/Mn were doped into the ZnO lattice resulting slight shift in near-band-edge emission. Moreover, the novel Raman peak at 586 cm−1 indicates two kinds of cations via doping that could affect the local polarizability. Magnetic measurements of the nanoparticles exhibits ferromagnetic behavior at room-temperature.

The demand for renewable raw materials is steadily rising as the drive for a green economy and a sustainable future accelerates. Mounting environmental issues and changing attitudes of consumers have made petroleum-based manufactured products more expensive and less desirable in the present world (as of 2016). Utilization of less valuable lignocellulosic fibres that are abundant and do not require irrigation for their cultivation makes them inexpensive and bio-degradable alternatives to petroleum-based synthetic fibres. These fibres are found in dry habitats in the USA, Asia and South Africa and contain over 2000 species worldwide, the properties of which slightly differ as a result of different soil conditions. In recent years, much research has been carried out into potential applications of milkweed fibre due to its incredible characteristics—such as hollowness, low density and hydrophobicity—particularly in technical textiles. The milkweed plant can adapt to almost any soil condition from swampy and moist to sandy and arid. It is a perennial plant and hence, once planted, does not require replanting each season and does not require any fertilizers, making the plant sustainable. Successful commercialization of milkweed as a crop is dependent upon mechanized harvesting, handling, drying and floss-processing systems. This chapter gives comprehensive information about the history of the milkweed plant and fibres, fibre morphology and characteristics, spinnability of milkweed fibres, fabric properties and potential application of milkweed fibres in such areas as clothing, lightweight composites, oil sorption as well as thermal and acoustic insulation.

Cerium oxide (CeO2) thin films were deposited on glass substrates by sputtering at various substrate temperatures. CeO2 films were characterized by X-ray diffraction, FESEM, PL and Raman analyses. X-ray diffraction patterns of films reveal fcc cubic structure with preferential orientation along (2 2 0) crystallographic plane. SEM images show that the particles are uniformly distributed on the film surface. The films were found to be well adheared to the substrates and pin holes are not observed on the surface of the films. PL spectra exhibits a strong near band-gap-edge emission and a broad blue, green luminescence, which can be assigned to the presence of Ce and O vacancies, amorphous phases, deep level impurities and structural defects. The relative intensity between the different peaks of the bands related to defects or impurities was studied as a tool for quality control of the films. Moreover, vibrational measurements through Raman analysis were carried out and the results are discussed.

Magnesium oxide nanotubes were prepared by electrospinning technique. The nanocatalysts have been characterized by various sophisticated techniques, including XRD, SEM, and TEM. The activities of these NT catalysts are promoting pyrazolyl 1,4-dihydropyridine syntheses have been extensively investigated. Various advantages associated with these protocols simple workup procedure, short reaction times, high yields and reusability of the catalyst.

The performance of ultraviolet protection, antimicrobial activity, soil release action and self-cleaning characteristics of nano zinc oxide (ZnO) with acrylic binder were assessed on the cotton fabric using pad-dry-cure method. Different precursors such as zinc chloride and zinc nitrate were used to synthesize nanoparticles by wet chemical technique. The synthesized nanoparticles were then characterized using Fourier transform infrared spectroscopy, particle size analyser, powder X-ray diffractometry and scanning electron microscopy. The nano ZnO finished cotton fabrics were tested for ultraviolet protection factor, antimicrobial activity, soil release action and self-cleaning action. The wash fastness of nano zinc oxide (ZnO) finished cotton fabrics after 5th, 10th, 15th and 20th washes were assessed. Also the ultraviolet protection factor values, percentage reduction in bacteria and soil release percentage in each washing stage are reported. The self-cleaning activity was assessed for 12, 24and 48 h duration by exposing 6% of coffee stain on the specimen fabrics to sunlight. The zinc oxide nanoparticle size of 24 nm was obtained from synthesis of zinc chloride as a precursor, and another nanoparticle size of 38 nm were obtained from synthesis of zinc nitrate as a precursor. The smaller nanoparticles (24 nm) show better results in terms of antimicrobial activity, soil release and self-cleaning action. In case of ultraviolet protection function, it was found that the fabrics treated with 38 nm nanoparticles exhibit higher ultraviolet protection factor values than the fabric treated with 24 nm nanoparticles. The durability of the imparted functions was in the range 25–38 washes for antimicrobial activity, soil release action and ultraviolet protection, respectively.

We report the use of highly porous, dense, and anisotropic TiO(2) derived from electrospun TiO(2)-SiO(2) nanostructures through titanate route in dye-sensitized solar cells. The titanate-derived TiO(2) of high surface areas exhibited superior photovoltaic parameters (efficiency7%) in comparison to the respective electrospun TiO(2) nanomaterials and commercially available P-25.

Summary Background. Wound healing occurs as a fundamental response to tissue injury. Several natural products have been shown to accelerate the healing process. Aim. To observe the efficacy of topical administration of an ethanolic extract of Ageratum conyzoides on cutaneous wound healing in rats. Methods. An ethanolic extract of A. conyzoides was prepared, and its wound-healing efficacy on rats was studied. An open excision wound was made on the back of each rat, and 200 μL (40 mg/kg body weight) of the A. conyzoides extract was applied topically once daily to the treated wounds. The control wounds were treated with 200 μL of 50% ethanol. The wound tissues formed were removed at 4, 8 and 12 days after wounding, and biochemical parameters such as DNA, total protein, total collagen, hexosamine and uronic acid were estimated. The extent of epithelialization and the tensile strength of the wounded tissues were also measured. Results. The A. conyzoides extract increased cellular proliferation and collagen synthesis. Wounds treated with the extract were found to heal much faster, based on the improved rates of epithelialization and wound contraction, and on the histopathological results. A 40% increase in the tensile strength of the treated tissue was seen. Conclusions. Topical application of A. conyzoides accelerates the rate of wound healing.

Extensive hydrogeological investigations followed by three-dimensional groundwater flow and contaminant transport modelling were carried out around a proposed uranium tailings pond at Seripalli in Andhra Pradesh, India, to estimate its radiological impact. The hydrogeological parameters and measured groundwater level were used to model the groundwater flow and contaminant transport from the uranium tailings pond using a finite-element-based model. The simulated groundwater level compares reasonably with the observed groundwater level. Subsequently, the transport of long-lived radionuclides such as 238U, 234U, 230Th and 226Ra from the proposed tailings pond was modelled. The ingrowths of progenies were also considered in the modelling. It was observed that these radionuclides move very little from the tailings pond, even at the end of 10,000 y, due to their high distribution coefficients and low groundwater velocities. These concentrations were translated into committed effective dose rates at different distances in the vicinity of the uranium tailings pond. The results indicated that the highest effective dose rate to members of the public along the groundwater flow pathway is 2.5 times lower than the drinking water guideline of 0.1 mSv/y, even after a long time period of 10,000 y.

In this contribution, we have synthesized series of 1-ethyl-3,5-bis[2-(aryl)ethenyl]-1H-indole based derivatives with different functional groups using Wadsworth–Emmons coupling. The sensing ability of the receptors has been studied for halides like tetrabutylammonium fluoride, chloride, bromide, iodide and bisulphate by UV–vis spectroscopy methods. In THF solution, compound A–E exhibits excellent selectivity with iodide ions over the other ions like tetrabutylammonium bromide (TBABr), tetrabutylammonium chloride (TBACl), tetrabutylammonium fluoride (TBAF) and tetrabutylammonium bisulphate (TBAHSO 4 ). The indole cores were observed effectively and selectively recognized biologically important iodide was reported. Significant absorption change was observed only for tetrabutylammonium iodide and no change with other anions. The absorption spectra indicated the formation of complex between host and guest is in 1:1 stoichiometric ratio. The association constants of A–E for iodide ions were found to be 3.2 × 10 4 M −1 , 3.9 × 10 4 M −1 , 4.2 × 10 3 M −1 , 2.9 × 10 3 M −1 and 2.14 × 10 3 M −1 , respectively.

The wireless nature and inherent features of mobile ad hoc networks make them vulnerable to a wide variety of attacks. In an internal attack, the attacker gains the normal access to the network and takes part in the network activities, either by some malicious impersonation to get the access to the network as a new node, or by directly compromising a current node and using it as a basis to conduct its malicious behaviors. In this paper, we develop a cluster based authentication technique to mitigate the internal attacks. The entire network is divided into hierarchical group of clusters, each cluster having a fully trusted cluster head. Each node holds a certificate issued by an offline certificate authority (CA). The Trust Count (TC) for each of the nodes can be estimated periodically for every trust evaluation interval (TEI), based on their access policy (AP). The certificate of a node is renewed or rejected by the cluster head, based on its trust counter value. By simulation results, we show that our proposed technique provides better packet delivery ratio and resilience against node capture.

In this research, the non-formaldehyde wrinkle-resistant treatment of cotton fabrics has been investigated using the citric acid (CA) as a cross-linking agent and sodium hypophosphite (SHP) as a catalyst together with nano-titanium dioxide (nano-TiO2) as a co-catalyst compound. The effect of the changes in the concentrations of CA, SHP, and nano-TiO2 on the wrinkle recovery angle (WRA), tensile strength, tearing strength, whiteness index, and flexural rigidity of cotton fabrics was studied using Box–Behnken design. It was found that the addition of nano-TiO2 could enhance the wrinkle resistance and decrease the flexural rigidity of the cotton fabric with little effect on the whiteness index, and tearing and tensile strengths of the treated fabric. The developed empirical models are found to be in good correlation with the selected variables ( r2 ≥ 0.8). From this study, it was concluded that 10% CA, 10% sodium dihydrogen phosphate, and 0.1% nano-TiO2 were the optimum concentrations required to enhance the WRA without adversely affecting the other physical properties of the treated cotton fabrics.

Geochemical processes that take place in the aquifer have played a major role in spatial and temporal variations of groundwater quality. This study was carried out with an objective of identifying the hydrogeochemical processes that controls the groundwater quality in a weathered hard rock aquifer in a part of Nalgonda district, Andhra Pradesh, India. Groundwater samples were collected from 45 wells once every 2 months from March 2008 to September 2009. Chemical parameters of groundwater such as groundwater level, EC and pH were measured insitu. The major ion concentrations such as Ca2+, Mg2+, Na+, K+, Cl−, and SO42− were analyzed using ion chromatograph. CO3− and HCO3− concentration was determined by acid–base titration. The abundance of major cation concentration in groundwater is as Na+ > Ca2+ > Mg2+ > K+ while that of anions is HCO3− > SO42− > Cl− > CO3−. Ca–HCO3, Na–Cl, Ca–Na–HCO3 and Ca–Mg–Cl are the dominant groundwater types in this area. Relation between temporal variation in groundwater level and saturation index of minerals reveals the evaporation process. The ion-exchange process controls the concentration of ions such as calcium, magnesium and sodium. The ionic ratio of Ca/Mg explains the contribution of calcite and dolomite to groundwater. In general, the geochemical processes and temporal variation of groundwater in this area are influenced by evaporation processes, ion exchange and dissolution of minerals.

The temporal dynamics of the concentrations of several proteins are tightly regulated, particularly for critical nodes in biological networks such as transcription factors. An important mechanism to control transcription factor levels is through autoregulatory feedback loops where the protein can bind its own promoter. Here we use theoretical tools and computational simulations to further our understanding of transcription-factor autoregulatory loops. We show that the stochastic dynamics of feedback and mRNA synthesis can significantly influence the speed of response of autoregulatory genetic networks toward external stimuli. The fluctuations in the response-times associated with the accumulation of the transcription factor in the presence of negative or positive autoregulation can be minimized by confining the ratio of mRNA/protein lifetimes within 1:10. This predicted range of mRNA/protein lifetime agrees with ranges observed empirically in prokaryotes and eukaryotes. The theory can quantitatively and systematically account for the influence of regulatory element binding and unbinding dynamics on the transcription-factor concentration rise-times. The simulation results are robust against changes in several system parameters of the gene expression machinery. � 2011 Biophysical Society.

Simple and selective indole based fluorescent sensors for iodide anions are reported. A series of 4,7-diaryl indole derivatives (DAIs) are designed and synthesized using Suzuki coupling. These DAIs shows significant changes in UV–vis and fluorescent intensity only with addition of iodides and not with other anions. The ability of these DAIs to function as selective iodide chemosensor is reported.

Nylon monofilament and polyester multifilament yarn find applications in fishing nets and parachute fabrics , each of which might demand different load levels to be sustained without breaking. While usage, it is quite likely that few places/spots in the yarn may get permanently deformed due to the application of high transverse compressive stresses. Such "Weak spots" in yarn are amenable to breaks. The aspect of lateral or transverse compression was studied with a crushing instrument that applied forces laterally on the filaments. The tensile properties of such filaments were obtained experimentally and were simulated using FEM. A good correlation was seen between theoretical as well as experimental values.

Biologically important pyrazolylpyridines were synthesized in excellent yield by the oxidation of pyrazolyl 1,4-dihydropyridines (pyrazolyl 1,4-DHPs) using tetrapropylammonium perruthenate/N-methylmorpholine-N-oxide (TPAP/NMO) under mild conditions at 0 °C.

Problem statement: In Mobile Ad hoc Network (MANET), both the routing layer and the Medium Access Control (MAC) layer are vulnerable to several attacks. There are very few techniques to detect and isolate the attacks of both these layers simultaneously. In this study, we developed a combined solution for routing and MAC layer attacks. Approach: Our approach, makes use of three techniques simultaneously which consists of a cumulative frequency based detection technique for detecting MAC layers attacks, data forwarding behavior based detection technique for detecting packet drops and message authentication code based technique for packet modification. Results: Our combined solution presents a reputation value for detecting the malicious nodes and isolates them from further network participation till its revocation. Our approach periodically checks all nodes, including the isolated nodes, at regular time period λ. A node which recovers from its misbehaving condition is revoked to its normal condition after the time period λ. Conclusion/Recommendations: By simulation results, we show that our combined solution provides more security by increased packet delivery ratio and reduced packet drops. We also shown that our approach has less overhead compared to the existing technique.

Electrospinning of a conjugated polymer is not possible due to the absence of chain entanglement (it exists as a rigid rod conformation in a solution), which is a prerequisite for electrospinning. In the present study, fabrication of core–shell nanofibers has been done by co-electrospinning of two components such as poly(3-hexyl thiophene) (P3HT) (a conducting polymer) or P3HT/PCBM as the core and poly(vinyl pyrrolidone) (PVP) as the shell. The TEM observation and FTIR analysis confirmed the encapsulation of the P3HT within the PVP polymer. Continuous P3HT or P3HT/PCBM nanofibers have been obtained by subsequent washing of the shell polymer template in a post-treatment step. These nanofibers were tested for solar cloth applications.

CdS nanoparticles (NPs) with high quantity and quality were successfully synthesized by co-precipitation method at air atmosphere in room temperature. The structure, morphology and optical properties of CdS NPs were investigated by x-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and selected area electron diffraction (SAED) pattern, ultra-violet visible (UV–vis) absorption spectroscopy, Raman spectroscopy and photoluminescence (PL) studies. XRD study confirmed the formation of crystalline CdS NPs with actual size as 2.73 nm. Raman spectroscopy was used to study the confinement of optical phonons modes in CdS NPs. The electrical properties examined with current-voltage characteristics well coincide with space-charge-limited conduction mechanism of inorganic semiconductors. The synthesized CdS NPs could be a great candidate for low-cost and efficient optoelectronic applications.

Mathematical simulation is the process of designing a model of a real system and then conducting experiments with the simulation to understand the system’s behavior. Mathematical simulation is widely used for investigating and designing compressors, and with a minimal number of simplifying assumptions, mathematical models can be used in conjunction with modern computing tools to solve complicated problems. A considerable amount of previous research has focused on the mathematical modeling of reciprocating air compressors used in automotive braking. The aim of the present work was to experimentally validate the mathematical model for such compressors. We present a simplified and effective mathematical model for estimating compressor performance, and this model can easily be executed using personal computers. Parameters such as compressor speed, discharge pressure and clearance volume were evaluated in terms of their effect on the thermodynamic behavior of compressors. The model can predict cylinder pressure, cylinder volume, cylinder temperature, valve lift and resultant torque at different crank angles; it can also predict the free air delivered and the indicated power of the compressor. Therefore, the model has been validated using experimental results.

Background: Diabetic foot ulcer is the one among and the most common complication of diabetes mellitus patients. Various studies from over the world for the past 2 decades discuss the important risk factors that decide the prevention and outcome of diabetic foot ulcer. In our prospective study we have discussed the risk factors focused on prevention and treatment of diabetic foot ulcer in a rural tertiary medical care centre.Methods: Totally 940 patients with the clinical diagnosis of diabetic foot ulcer admitted in our hospital surgical department were studied prospectively with their clinical symptoms and signs of diabetic foot ulcer and various evaluations done for the comorbid conditions with the help of other specialty departments. All these risk factors studied in our rural based tertiary medical centre were collected in a designed format were studied and discussed in comparison to the chosen data available in various studies done at various countries.Results: All the 940 patients admitted for diabetic foot ulcer who underwent a methodical evaluation for risk factor showed an elevated HbA1c more than 8 in 720 (77.5%) patients, bony involvement like osteomyelitis in 274 patients (29%) , peripheral vascular disease in 421 (44.9%), neuropathy in 533 patients (56.7%), nephropathy 163 (17.34%), retinopathy in 102 (10.85%) and heart disease in 375 (39.89%).Conclusions: Proper protocols to the prevention and management of foot ulcer in diabetic patients have not reached many health care centres and it is imperative to stress on the related comorbid risk factors which influence the prevention and healing of diabetic foot ulcer. Present study done at a rural tertiary health care centre is mainly focused on the incidence of risk factors which modulates and modify the diabetic foot ulcer prevention and management. This study aims to support the health professionals to identify the risk factors apart from the clinical picture of diabetic foot ulcer that may enhance the efficient management and avoid the unnecessary morbidity and mortality.