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The environmental and economic concern is the biggest challenge cement industry is facing today. During the production of cement CO2 is produced from clinkerization which is a major greenhouse gas responsible for causing global warming [1] . By reduction in clinker consumption through increasing utilization of pozzolanas will not only save clinker and increase durability of concrete structures but also act as a good stewardship towards sustainable development. An attempt has been made in-house to partially replace the cement with Mine’s waste (−15 mm) where physical and mechanical properties of materials used in concrete were thoroughly investigated. The material was processed by milling using a in-house ball mill & characterized by X-ray Fluorescence, Particle Size Distribution to understand its overall performance and effects. With an aim not to lose the strength of designed concrete far from original concrete mix, specimens were prepared with 2%,4%,6%,8%,10% & 12% substitution by weight of the Portland cement by the Mine’s waste and the ratio of water used as well as sand and aggregate were remain fixed. For each replacement, cubes were casted for measuring 7 days, 28 days & 56 days compressive strength, Flexural Strength & Durability Test. From the test results, it was observed that cement can be replaced with 10% of Mine’s waste in concrete with increased strength and better durability as compared to normal concrete structure and further up to 12% replacement can be done for smooth plastering and mortar purpose.

Supplementary cementitious materials or SCMs are oftenly used as substitute of conventional Portland cement to reduce carbon footprint of cement industry while improving strength of cement. The benefit to ‘reduce the clinker content’ in cement products has two advantages. Primarily it promotes to reduce the thermal energy consumption and CO2 emissions linked with clinker production in rotary kilns. It is widely known that on production of 1 Ton of clinker generates over 800–820 kg of CO2. The secondary motivation is to conserve the limestone resources by reduce consumption through judicious utilization towards sustainable development. Majorly the research to minimize environmental impact of cement manufacturing is done on industrial byproducts such as fly-ash, silica fumes & slag to be used as SCM but this paper utilizes the Phyllite which is a mine waste generated during extraction & quarrying and is dumped unattended in the landfills near the mines. Calcined phyllite was characterized through various laboratory tests such as Particle Size Distribution, X-ray Fluorescence, XRD and TGA. In the present study, Clinker was partially replaced in cement manufacturing with 2%, 4%, 6%, 8% & 10% by weight with calcined Phyllite as mineral admixture. The Physiochemical testing of designed cement samples were done as per IS 4031 & IS 4032 respectively. The strength and durability test such as compressive strength, flexural strength, and durability test were conducted on the Phyllite cement mortar cubes and results were compared with the control cubes of blank cement mortar of OPC 43 grade.

The present work is devoted to the investigation of the free vibrations of a homogeneous isotropic nonlocal thermoelastic cylinder with void. Time-harmonic variations are used to reduce the governing partial differential equations to a system of ordinary differential equations. The frequency equation for the continuation of vibrations for the mode numbers in the considered cylinder is deduced in closed form for traction-free and isothermal/thermally insulated boundary conditions. To observe the free vibration, the frequency equation is further studied by using the numerical iteration method with the help of MATLAB software. The numerically simulated results from the analytical solutions are shown graphically for the natural frequency, thermoelastic damping and the frequency shift against mode numbers for the nonlocal as well as the local thermoelastic cylinders in the presence and absence of the void.

The intermittent nature of solar energy is a dominant factor in exploring well-designed thermal energy storages for consistent operation of solar thermal-powered vapor absorption systems. Thermal energy storage acts as a buffer and moderator between solar thermal collectors and generators of absorption chillers and significantly improves the system performance. Vapor absorption chillers are available in half, single, double, and triple-effect modes of operation and operate at temperatures ranging from 75 to 220 °C to produce a cooling effect with COPs ranging from 0.3 to 1.8. Thus, the selection of appropriate solar collectors and thermal energy storages are two significant decisions affecting the consistency of output of a vapor absorption refrigeration system. The present review of state of the art is focused on the appropriate selection, from among different types of solar collectors available to meet the demand of capacity and degree of thermal energy required in operating absorption chillers at optimum performance. Characteristics of various thermal energy storage systems and their integration with solar thermal collectors and absorption chillers are also investigated to meet the demand for heat during non-sunshine hours or periods of low solar intensity. In the latter section, economic feasibility is explored so that a sustainable solar cooling system can be proposed which can work consistently with the best performance throughout its entire life.

Polymer based microstructured optical fibers (MPOFs) like their silica counterparts guides the light through the use of array of wavelength-scale microstructures in the cross-section, and offers pivotal dominance over both polymer optical fibers (POFs) as well as air/silica microstructured optical fibers (MOFs). We aspire to investigate the optical characteristics of the solid-core MOFs based on polymer material by using an efficient theoretical model. Theoretical evidences to demonstrate that fiber support only single mode are explored and cut-off conditions are identified. We evaluate the effective index of higher-order mode (HOM) for the solid-core MPOF at terahertz (THz) regime, and the coupling properties of long-period gratings (LPGs) in MPOF are also examined. Further, the sensitivity coefficient is studied for realizing the efficient coupling in the evanescent field based applications. Theoretical results are compared with those as reported in the literature. Relative errors are also included.

As matter of course traditional silica optical fibers have been widely utilized in slow-light generation promoted by an inelastic scattering process designated as stimulated Brillouin scattering (SBS). We intend to explore two different configurations of the solid-core Er-doped and undoped tellurite glass triangular lattice microstructured optical fibers (T-MOFs) by using a theoretical model, for investigating the optical characteristics of slow-light generation assisted by SBS, such as effective mode area, minimum and maximum pump powers, Brillouin gain and the time delay. Also, we studied the effect of cladding parameters on effective index of the mode, and the spectral response of group velocity as well as dispersion coefficient for both geometries of the MOFs. Comparisons have been made with those numerically simulated results as available in the literature, and the relative errors are also evaluated.

The evolution of microstructured optical fibers with hexagonal array (H-MOFs) of air-holes rooted in the background of undoped silica has led to the realization of an ideal host for encouraging and technologically entitled optical properties. We focus to explore the divergence of radiation into free space from the end-facet of solid-core H-MOFs by using the improved theoretical model. Also, we investigated the wavelength dependence of beam divergence angle for principal core mode of H-MOFs under step-index fiber approximation (SIFA). Experimental results have been included for comparison.

Silica based optical waveguides are restricted by the silica material parameters such as low nonlinear refractive index and transparency below 3.0 μm. These limitations have led to investigation of new materials with high nonlinear refractive index and transparency in the mid-infrared (IR) region such as tellurite glasses, possessing considerable interest for a broad range of applications in the domain of optical telecommunication and sensing due to their wealth of excellent optical characteristics. We aim to explore the fundamental propagation properties of tellurite glasses based high-index core microstructured optical fibers (MOFs) by using the field model to judge the feasibility of using nonsilica glasses as the background material. Comparison with available numerical simulation results also has been included.

The advent of polymer (or plastic) optical fibers (POFs) with porous cross-section has contributed significantly to the sensing applications. We intend to explore the sensing attributes of polymer-based one-rod core microstructured optical fibers (P-MOFs) via utilizing an auxiliary approach. The sensitivity coefficient and the overlapping factor of P-MOF’s introduced design in air-filled and water-filled layouts against the structural parameters are exploited. We reported the overlapping factor of ~ 94% and ~ 82% for the said configurations of the fibers, respectively, at the wavelength of 0.633 µm. The confinement loss, mode-index, and effective mode-area are also evaluated for the anticipated structures. For assessing the confinement loss, an alternative approach based on double-clad fiber (DCF) approximation is employed. The validity of the simulated results is scrutinized with those as documented in the literature. Relative errors are also tabulated.

To sustain the pace with immense prominence, interest in low-loss terahertz (THz) waveguides increases due to their particular applications in the multidisciplinary arena. This paper narrates a novel solid-core polymer-based square lattice micro-structured optical fiber (SL-MOF) with circular air-holes for efficient propagation of THz waves. The anticipated model’s guiding attributes are described by employing the numerically efficient finite-element method (FEM) in conjunction with an auxiliary Ring Model. Numerical analysis of the model exhibits confinement loss of about ~ 10 -7 dB/cm and low effective material loss of ~ 0.19 cm -1 at the applied frequency of 1.0 THz. It is also demonstrated that the considered geometry furnishes low bending loss over the extended range of THz frequency. The relative sensitivity coefficient is evaluated in context for the targeted design parameters to enable the said model’s practical utility. Other nameworthy propagation characteristics, such as effective mode-index, power fraction, effective mode-area, numerical aperture, spot-size, and the beam divergence are also investigated. The improved outcomes are anticipated that the proposed configuration will be opened a new epoch in the THz waveband.

Low-cost packaging and compact-size of optical fiber based optoelectronic devices and passive components have become vogue of enlargement in telecommunication, sensors and integrated circuits; therefore, it is an object of appreciable affair for packaging design to appraise the influence of misalignments during coupling. Efficient free-space coupling is predominant for achieving the communication systems with high bit rate at minimal loss values. Power coupling losses for lowest-order core-mode of large mode-area (LMA) hexagonal photonic crystal fibers (H-PCFs) in presence of misalignments (e.g., axial, radial and angular) with reference to input field is evaluated by utilizing the merits of an optical model. It is observed that LMA H-PCFs can be employed as appropriate aspirant for the efficient coupling strategy; moreover, theoretical results concerning coupling proficiency of classical SMF-28 are also studied. We investigated that LMA-10 PCF is not that sensitive to radial misalignment in contrast to the classical SMF; therefore, it can be utilized to frame manifold delays in optical true-time-delay (TTD) engines deployed on White cell concepts. The typical values of 1-dB tolerance are documented and the factors affecting coupling performance are also explored. Comparative results for the optimum butt-coupling loss are incorporated as articulated in the literature.

The environmental and economic concern is the biggest challenge that concrete industry is facing today. Advancement in utilization of wastes in concrete as a mixture reduces usage of natural resources. Phyllite is a kind of foliated metamorphic rock generates during underground mining .Phyllite was calcined at 850 to 900oC in furnace and ground in ball mill. In this study, cement was partially replaced by weight with calcined phyllite to make M30 grade of concrete with 0% (Control mix), 2%, 4%, 6%, 8%, & 10%, (which are designated as M1, M2, M3, M4, M5 and M6). The laboratory tests such as slump value, compressive strength, flexural strength, water absorption, chloride ion penetration and durability in acidic and basic medium were conducted on the phyllite concrete and results are compared with the control mix. Through results it is concluded that cement can be replaced in concrete at the tune of 8% with Calcine Phyllite (CP) without affecting the strength and durability. The aim of the experiment is to find the maximum content of mines calcined Phyllite that can be used as a partial replacement of cement without compromising the quality on any of the characteristics of concrete.

Optical fiber surface plasmon resonance (SPR) based sensors are doubtlessly required for the coming development of miniaturised and compact sensor system. SPR based on solid-core hexagonal microstructured optical fiber (H-MOF) with a conducting metal oxide (such as indium tin oxide (ITO)) as the sensing material is demonstrated as a refractive index sensor in infrared (IR) domain. The effect of ITO film thickness at different wavelength is simulated theoretically. We reported the sensitivity of ~5.04 µm/RIU (Refractive Index Unit).

Traditional fusion splicing technologies are not usable for the high-index core triangular lattice microstructured optical fibres (MOFs), as the characteristic air-holes pattern often collapse during splicing, significantly increasing splice losses due to distortion of the waveguiding structure. The low-loss splicing of MOF and the traditional single-mode fibre (SMF) can be achieved by enlarging the mode-field diameter (MFD) of MOF, facilitating to an optimum mode-field match at the splicing interface. Using our recently developed improved field model Sharma and Sharma (2016), we aim to investigate the modal characteristics of high-index core MOF as a mode-field expander, and low-loss splicing between an MOF and the standard step-index single-mode fiber by using controlled all air-hole collapse method. For comparison, experimental and the numerical simulation results have been included, as available in the literature. Relative errors are also given.

Microstructured optical fibers (MOFs) allow a variety of advanced materials to be infiltrated in their air-voids for obtaining the increased fiber functionality, and offering a new versatile platform for developing the compact sensors devices. We aim to investigate the thermal characteristics of high-index core triangular hybrid polymer/silica MOFs with circular air-voids infused with polymer by using the analytical field model [1]. We demonstrate that infiltration of air-voids with polymer, e.g., polydimethylsiloxane (PDMS) can facilitate to tune the fundamental modal properties of MOF such as effective index of the mode, near and the far-field profiles, effective mode area and the numerical aperture over the temperature ranging from 0 °C to 100 °C, for different values of relative air-void ratios. The evolution of the mode shape for a given temperature has been investigated in transition from near-field to far-field regime. We have studied the thermal dependence of splice losses between hybrid MOF and the standard step-index single-mode optical fiber in combination with Fresnel losses. For enhancing the evanescent field interactions, we have evaluated fraction of power associated with fundamental mode of hybrid MOF. We have compared the accuracy of our results with those based on full-vector finite-difference (FD) method, as available in the literature.

Microstructured optical fibres (MOFs) are seen as novel optical waveguide for the potential applications in the terahertz (THz) band as they provide a flexible route towards THz waveguiding. Using the analytical field model (Sharma et al., 2014) developed for index-guiding MOFs with hexagonal lattice of circular air-holes in the photonic crystal cladding; we aim to study the propagation characteristics such as effective index, near and the far-field radiation patterns and its evolution from near-to-far-field domain, spot size, effective mode area, and the numerical aperture at the THz regime. Further, we present an analytical field expression for the next higher-order mode of the MOF for studying the modal properties at terahertz frequencies. Also, we investigate the mode cut-off conditions for identifying the single-mode operation range at THz frequencies. Emphasis is put on studying the coupling characteristics of MOF geometries for efficient mode coupling. Comparisons with available experimental and numerical simulation results, e.g., those based on the full-vector finite element method (FEM) and the finite-difference frequency-domain (FDFD) method have been included.

The excellent propagation properties of square-lattice microstructured optical fibers (MOFs) have been widely recognized. We generalized our recently developed analytical field model (Sharma and Sharma, 2016), for index-guiding MOFs with square-lattice of circular air-holes in the photonic crystal cladding. Using the field model, we have studied the propagation properties of the fundamental mode of index-guiding square-lattice MOFs with different hole-to-hole spacing and the air-hole diameter. Results for the modal effective index, near and the far-field patterns and the group-velocity dispersion have been included. The evolution of the mode shape has been investigated in transition from the near to the far-field domain. We have also studied the splice losses between two identical square-lattice MOFs and also between an MOF and a traditional step-index single-mode fiber. Comparisons with available numerical simulation results, e.g., those based on the full-vector finite element method have also been included.

The level of radon concentration has been assessed using the Advanced SMART RnDuo technique in 30 drinking water samples from Jammu district, Jammu and Kashmir, India. The water samples were collected from wells, hand pumps, submersible pumps, and stored waters. The randomly obtained 14 values of radon concentration in water sources using the SMART RnDuo technique have been compared and cross checked by a RAD7 device. A good positive correlation (R = 0.88) has been observed between the two techniques. The overall value of radon concentration in various water sources has ranged from 2.45 to 18.43 Bq L, with a mean value of 8.24 ± 4.04 Bq L, and it agreed well with the recommended limit suggested by the European Commission and UNSCEAR. However, the higher activity of mean radon concentration was found in groundwater drawn from well, hand and submersible pumps as compared to stored water. The total annual effective dose due to radon inhalation and ingestion ranged from 6.69 to 50.31 μSv y with a mean value of 22.48 ± 11.03 μSv y. The total annual effective dose was found to lie within the safe limit (100 μSv y) suggested by WHO. Heavy metal analysis was also carried out in various water sources by using an atomic absorption spectrophotometer (AAS), and the highest value of heavy metals was found mostly in groundwater samples. The obtained results were compared with Indian and International organizations like WHO and the EU Council. Among all the samples, the elemental analysis is not on the exceeding side of the permissible limit.

Infiltration of functional materials into the voids of microstructured optical fibers (MOFs) can provide response under different physical fields leading to tunable propagation properties of the MOFs, for the promising all-in-fiber optical components. In this article, using an analytical field model, we study the light guiding properties of MOFs with triangular lattice of voids infiltrated with polydimethylsiloxane (PDMS) elastomer, which has been selected owing to its good optical and mechanical properties. We demonstrate that infiltration of voids with PDMS can lead to tune the modal properties of MOF over the wavelength ranging from 500–1800 nm for different normalized void ratios. Further, we elucidate that the effective mode area can be tailored to any desired value between 38–264 μm2 at the telecommunication wavelength of interest by reducing the relative void ratios, which can be useful in the domain of fiber laser applications. Comparisons with numerical simulation results based on the full vector finite-difference (FD) method and the finite-difference time-domain (FDTD) method have been included to further fine tuning of the design parameters.

We elucidate guiding characteristics of modified hexagonal lattice microstructured optical fibres (MOFs) which are popularly, known as the MOFs with square lattice of air-holes (SL-MOFs) in the cladding. An alternative analytical field model is utilized to explore the radical propagation attributes of SL-MOFs. For comparison numerical results based on the finite element method are also generated for the same model. Coherent agreement between the results is achieved, which justifies the strength of our approximate method; moreover, it furnishes a swift approach for exploring the fundamental modal properties of such optical waveguides.

A new development in optical fiber technology that has attracted interest for multitude of novel and potential applications is an all-in-silica microstructured optical fibre (MOF) with one-rod core. We aim to estimate the functional core dimension for one-rod core triangular MOF (T-MOF) from its geometrical characteristics by using an alternative analytical field model. Moreover, to scrutinize the validity of the choice of effective core dimension (by adapting V-parameter, i.e., the normalized frequency) for T-MOF, we have explored the rudimentary propagation characteristics of the T-MOF in single mode guidance realm. We made comparisons with those which are based on the experimental and numerical studies. Relative errors are also reported.

We present an improved version of our earlier developed analytical field model for the fundamental mode of index-guiding microstructured optical fibers (MOFs), to obtain better accuracy in the simulated results. Using this improved field model, we have studied the splice losses between an MOF and a traditional step-index single-mode fiber (SMF). Comparisons with available experimental and numerical simulation results have also been included.

To access the full practical utility of the solid-core (SC) hexagonal microstructured optical fibers (HMOFs), compact low-loss mechanically stable splicing of HMOFs to standard single-mode fibers (SMFs) is highly appreciated; however, collapsing of air-holes and the mode-field (MF) mismatch are the two pivotal factors contributing to huge splice loss. Under certain specific conditions, collapsing of air-holes can yield to MF-adaptation at the end-facet of HMOF, and thus, owing to lower the loss with SMF. Therefore, we intend to numerically simulate the results in respect of MF-adaptation in SC-HMOF based on selective and controlled collapsing of air-holes to optimize the MF-matching at the joint interface by employing a recently proposed numerical method, which takes advantages of finite-element method (FEM) in combination with a simplified Ring Model. For validating the applicability of our method, we evaluated the splice losses between dissimilar configurations of large mode-area (LMA) HMOFs and the SMF-28 at 1.55 µm and achieved reasonably low-loss values which are coherent to experimentally measured values as published in the literature.

Background: Adenoid hypertrophy is a common disorder in the paediatric population, presenting with multiple signs and symptoms ranging from nasal obstruction to obstructive sleep apnoea. Most common symptom is usually nasal airway obstruction. This prospective, randomized study aims to evaluate the efficacy of mometasone furoate spray in reducing size and clinical symptoms in patients with adenoid hypertrophy compared to saline spray.Methods: 60 patients in the age group of 3-11 years were enrolled in the study. Five symptoms were included that were hypo nasal speech, snoring, night cough, open mouth breathing and nasal obstruction which were scored as never=0, mild (sometimes)=1, moderate (less than 50% of times)=2, and severe (constant)=3. Diagnosis of adenoid hypertrophy was made on basis of nasal endoscopy.Results: Significant improvement was seen in individual as well as overall symptom score in group A as compared to group B after 8 weeks of treatment (pConclusion: Intranasal steroid sprays have good role in decreasing the symptoms of adenoid hypertrophy and has reduced number of adenoidectomies required. The long-term effects as well as optimal duration of therapy is still controversial and needs to be studied further.

Chalcogenide glasses are furnished with several beneficial features such as high nonlinear coefficient, and their low bulk material losses as compared to silica in mid-infrared (IR) spectral regime makes them doubtlessly as one of the excellent candidates with highly tunable optical characteristics. They have wide transparency in IR domain and can be drawn into fine optical fibers; moreover, possessing potential applications in nonlinear optics realm. We investigated the elementary modal characteristics of solid-core air/chalcogenide hexagonal microstructured optical fibers (H-MOFs) such as mode-index, near-field and far-field intensity patterns, mode-field diameters (MFDs), dispersion and nonlinear characteristics with different geometrical configurations by implementing an alternative theoretical model. Chalcogenide glass H-MOFs as a potential candidate for slow-light generation in IR regime is explored. Also, the utility of such fibers for evanescent field based sensing applications is examined. The strength of the model has been checked by comparing the results with experimental and those which are based on numerical simulation, as available in the literature. Relative errors are also quoted.

To inscribe the long-period gratings (LPGs) in an index-guiding (or the solid-core) microstructured optical fiber (MOF), the opto-geometrical parameters of the fiber have to be determined, at first. Using our earlier developed analytical field model, we have evaluated the effective index for the fundamental core mode of the triangular lattice-based MOF, and the effective index of the fundamental cladding mode is obtained by approximating hexagonal unit cell by a circular unit cell. We demonstrate that the grating period of the LPGs obtained using the radius of the equivalent circular unit cell of Λ/2 and $$\varLambda \left( {{{\sqrt 3 } \mathord{\left/ {\vphantom {{\sqrt 3 } {2\pi }}} \right. \kern-0pt} {2\pi }}} \right)^{1/2}$$ , which are the two widely accepted radii for evaluating the effective index of the fundamental cladding mode, do not match well with the available experimental results. Therefore, to achieve better agreement in the results, we have proposed the linear combination of these two radii. Comparisons with available experimental results have also been included.

Splice losses between the transmission optical fibers and the fiber-based devices have been considered as one of the bottlenecks in accomplishing the optical networks. Consequently, the practical utilization of specialty optical fibers such as triangular solid-core microstructured optical fibers (T-MOFs) in conjunction with splicing to dissimilar standard single-mode fiber (SMF) prerequisite a trustworthy, repeatable and robust low-loss splicing. Utilizing an enhanced field model, we appraised the splice losses between two similar T-MOFs without considering collapsing of air-holes at the joint interface with azimuthal and transverse offsets, and the splice loses between T-MOF and classical SMF are also explored. Collapsing of air-holes can facilitate to minimize the mode-profile inconsistency at splicing interface and hence, lowering the losses; therefore, we evaluated the mode-field diameter (MFD) as a function of collapse ratio. We reported splice losses of ~0.378 dB and ~5.032 dB at 1.55 µm between two identical T-MOFs with Λ = 4.0 µm, for the case of azimuthal and transverse offset, respectively. Also, we examined the consistency of our results by evaluating the relative errors, and the comparisons have been incorporated with those as reported in the literature.

Low-loss splicing of index-guiding microstructured optical fibers (MOFs) and conventional single-mode fibers (SMFs) can be achieved by enlarging the mode field diameter of MOFs, which leads to an optimum mode field match at the joint interface. We study analytically the low-loss fusion splicing between an MOF and an SMF by expanding the modal field of MOF, using the controlled air-hole collapse method. Our method is simple and offers analytical solution for light coupling between MOFs and SMFs. Comparisons with available experimental and simulation results have also been included.

Mode field diameter (MFD) is one of the important parameters for determining the optical performance of single mode microstructured optical fibers (MOFs). We use our earlier-developed analytical field model for the mode of MOFs to obtain the mode field diameters (MFDs) using a variety of definitions in use. We also give analytical expressions for various MFDs. We further show that Gaussian approximation based analysis for the MFDs does not give satisfactory results. The processing of experimental data should not be based on the assumption of Gaussian field. It is suggested that MFD should be obtained by a processing of 2-dimensional field data, as a linear scan in one direction could give unsatisfactory results.

We study analytically the light guiding properties of the chalcogenide glass based solid core or index-guiding microstructured optical fiber with the hexagonal and the square lattice of circular voids or air-holes in the cladding. The effective index of the fundamental mode, the group velocity dispersion and the effective mode area with different configurations of MOF has been calculated. Comparisons with the numerical simulation results have been included.

We have recently developed a simple analytical model to study propagation characteristics of microstructured optical fibers (MOFs). We have used this model to study splice losses between two MOFs and also between an MOF and a conventional fiber. We have also presented here the results on evolution of fundamental mode from near-field to far-field, the effective mode area and the beam divergence using this model. Comparisons with available experimental and modeling results have also been included.

Modal coupling characteristics and resonance spectral response of long-period gratings in microstructured optical fibers are analytically investigated with respect to its sensitivity to change in index of refraction of the measurand in the voids.

Using our earlier developed analytical field model we have studied the modal properties of index-guiding or solid-core microstructured optical fibers with square-lattice of circular voids or air-holes in the photonic crystal cladding made with high nonlinearity non-silica glass composition material as well as fused silica glass. For comparison the numerical simulation results have been included.

The current standard treatment for sudden sensorineural hearing loss (SSNHL) comprises of tapered course of oral corticosteroids. Intratympanic steroids are introduced as another modality of treatment, but management of SSNHL continues to be debatable. The present study was designed to evaluate the efficacy of steroids given orally and by the intratympanic route.A prospective, randomized, open-labeled study was conducted involving 42 patients. These were randomly divided into two groups; group I patients received oral prednisone tapered over 14 days, and group II patients were treated with intratympanic methylprednisolone (40 mg/mL). One milliliter of the drug solution containing 40 mg of the drug (40 mg/mL) was injected into the middle ear cavity through the trans-tympanic route. The drug was injected twice a week for 2 weeks. The total duration of the study was 60 days, and hearing outcome was assessed on the basis of change in pure tone average.An improvement of 18.24±8.72 dB was recorded in group I patients treated with oral prednisone in comparison to 14.68±12.88 dB improvement in group II. Statistically significant improvement in hearing was observed in both groups, but it was not significant when group I and group II were compared.The post-treatment outcomes among patients who receive either oral prednisone or intratympanic methylprednisolone within 2 weeks of onset of symptoms were comparable. The outcomes were affected by degree of hearing loss and association of SSNHL with vertigo.

IGBT power supply is a single-phase H bridge inverter capable to provide current of ±12kA with 1MA/sec ramp rate. This paper describes performance requirements, ratings, inverter design calculations, multimodular topology, protections, fast control, symmetrical layout, bus bar engineering, and cooling requirement and test results.

Microstructured optical fibers (MOFs) have generated broad interest due to their extraordinary optical properties which arises from the combination of wavelength scale features in the photonic crystal cladding and the high index contrast between the background material and the air. We analytically study the optical properties of nonsilica glasses such as tellurite (TeO2) glass based MOFs by using our earlier developed analytical field model. We have compared the accuracy of our simulated results with numerical simulation results available in the literature.

Microstructured optical fibers (MOFs) have wavelength scale periodic microstructure running along their length. Their core and two-dimensional microstructured cladding might be based on varied geometries and materials, enabling light guidance due to different propagation mechanisms over an extremely large wavelength range, extending to the terahertz (THz) frequency region. As a result, these fibers have revolutionized the optical fiber technology by means of creating new degrees of freedom in the fiber design, fabrication and applicability. We analytically study the modal properties of terahertz microstructured optical fiber (THz MOF), by using our analytical field model, developed for optical waveguides.

Microstructured optical fibers (MOFs), made entirely from undoped fused silica consisting of a central defect region surrounded by multiple air holes that run along the length of the fiber are attracting much attention in recent years because of unique properties which are not realized in case of conventional optical fibers

The mode-field expander (MFE) is a microstructured optical fiber (MOF) based device that enlarges the modal field distribution and can couple light from large mode area (LMA) fibers into small core fibers or vice-versa and other optical waveguides. Using our earlier developed analytical field model, we studied the mode-field expansion in MOFs having triangular lattice, and low-loss splicing of MOFs to standard single-mode fibers (SMFs), based on the controlled all airhole collapse method, which leads to an optimum mode-field match at the joint interface of the MOF-SMF. Comparisons with available experimental and simulation results have also been included.

Using our earlier developed analytical field model, which retains the required azimuthal variation of field for the index-guiding microstructured optical fibers (MOFs), we show that Gaussian approximation based analysis for the mode field diameters (MFDs) is likely to give inaccurate results and suggest improvements.

Based on variational principle, we have earlier developed an analytical model for the modal field of indexguiding microstructured optical fibers (MOFs). Using the model, we study the linear properties of MOF such as spot-sizes; their application in calculating numerical aperture NA and splice loss between an MOF and SMF-28 with transverse offset. Comparisons with available experimental and simulation results have also been included.

We have recently developed a simple method based on variational principle for the scalar analytical approach to study the propagation characteristics of MOFs. The model retains required azimuthal variation of field unlike Effective index method (EIM). We have analyzed, based on this model, the splice loss between two MOFs and that between an MOF and a conventional step‐index fiber (SMF‐28). As expected, the splicing between two MOFs depends on the relative orientation of air‐holes. For typical fibers, this loss could be as high as 0.23 dB.

For inscription of long-period grating in microstructured optical fibers (MOFs), their cladding parameters need to optimize. Using our earlier developed field model for index-guiding MOFs with triangular lattice of voids these parameters can be optimized.

Modifying our earlier developed analytical field model we have studied the modal properties of index-guided microstructured optical fibers with square-lattice of air-holes in photonic crystal cladding. Comparison with available numerical simulation results has been included.