Single-wavelength bidirectional 4-core MCF self-homodyne coherent link.

In this paper, we propose and demonstrate a single-wavelength bidirectional self-homodyne coherent (SHC) link over a 125 µm cladding diameter based multicore fiber (MCF). The 4-core MCF based link efficiently uses two cores for each direction of propagation. In either direction, one of the cores carries a dual-polarized 40 Gbaud 16-QAM signal, and the second core carries a 40 Gbaud 16-QAM signal in one of the polarizations with the carrier multiplexed in its orthogonal polarization. Thus, a 480 Gbps data transmission rate is achieved in either direction of propagation over the 12.8 km long 4-core MCF. The SHC link operates at the same wavelength for each of the directions and eliminates the need for reconfigurable transceivers. A low-cost DFB laser (linewidth = 1 MHz) is used to demonstrate the bidirectional link, and the bit error rates (BERs) of the received signals are <5.5×10-4. With higher baud rates, this approach can meet the capacity requirements of future short-reach data center interconnects (DCIs).

Adaptive electro-optic equalization in low-power coherent-lite interconnects.

In this paper, we propose an adaptive electro-optic equalizer for short-reach interconnects employing coherent modulation and detection. The equalizer consists of two main components: an optical equalizer filter and an electronic controller. The equalizer filter compensates for the linear dispersion occurring in the channel, while the electronic controller adaptively determines the weight coefficients of the equalizer. To achieve adaptive adjustment, we have introduced a random search algorithm. Extensive simulations have been conducted to evaluate the performance of the equalizer in a 120 Gbaud homodyne coherent link, and the results show great promise. The proposed equalizer has the potential to greatly improve the overall power efficiencies of receivers in short-reach coherent-lite interconnects.

To Study the Clinical Profile and Management of Cellulitis of Lower Limb in Northern India.

Cellulitis is a bacterial infection of the dermis and subcutaneous tissues occupying a large proportion of hospital beds. This study was conducted for analysis of patients with cellulitis according to their demographics and clinical presentation and to examine their comorbidities, complications, and its management. This observational cross-sectional study was conducted in the Department of Surgery at Santosh Medical College and Hospitals involving a total of 60 cases having cellulitis and other soft tissue infections of lower limb. Analysis of their demographic profile, management, and complications was done. Cellulitis is seen commonly in males, 46 (76.6%). The mean age of patients affected by cellulitis in the study was 36.4 ± 1.23 years. The most common site affected is leg involving more people in field jobs. The most common risk factor was trauma in 46.6%, and other factors were diabetes mellitus and smoking, while abscess formation was the most common complication observed in 36.6% of cases. A total of 56.6% cases were managed conservatively, while 43.3% cases required surgical intervention. Mean hospital stay in this study was 5.02 ± 0.23 days. It was concluded that cellulitis is subcutaneous, spreading bacterial infection is more common in males, and its incidence is highest in working age group population. Lower limb is commonly involved. Trauma, smoking, and diabetes are significant risk factors for development of cellulitis. Abscess is the most common complication. About 50% patients with cellulitis can be managed conservatively and the rest require surgical intervention.

Protein-assisted scalable mechanochemical exfoliation of few-layer biocompatible graphene nanosheets.

A facile method to produce few-layer graphene (FLG) nanosheets is developed using protein-assisted mechanical exfoliation. The predominant shear forces that are generated in a planetary ball mill facilitate the exfoliation of graphene layers from graphite flakes. The process employs a commonly known protein, bovine serum albumin (BSA), which not only acts as an effective exfoliation agent but also provides stability by preventing restacking of the graphene layers. The latter is demonstrated by the excellent long-term dispersibility of exfoliated graphene in an aqueous BSA solution, which exemplifies a common biological medium. The development of such potentially scalable and toxin-free methods is critical for producing cost-effective biocompatible graphene, enabling numerous possible biomedical and biological applications. A methodical study was performed to identify the effect of time and varying concentrations of BSA towards graphene exfoliation. The fabricated product has been characterized using Raman spectroscopy, powder X-ray diffraction, transmission electron microscopy and scanning electron microscopy. The BSA-FLG dispersion was then placed in media containing Astrocyte cells to check for cytotoxicity. It was found that lower concentrations of BSA-FLG dispersion had only minute cytotoxic effects on the Astrocyte cells.

Demonstration of a low-power, local-oscillator-less, and DSP-free coherent receiver for data center interconnects.

Performance limitations of currently employed four-level pulse amplitude modulation links and high power consumption of digital signal processing (DSP)-based coherent links for further increase in capacity create an urgent demand for low-power coherent solutions for short-reach data center interconnects. We propose a low-power coherent receiver with analog domain processing for a self-homodyne link. To validate the proposed scheme, a 10 GBd polarization multiplexed carrier-based self-homodyne quadrature phase-shift keying system with a constant modulus algorithm-based equalizer chip is experimentally demonstrated. Also, energy consumption per bit estimates show that the proposed approach results in significant power reduction in comparison with conventional DSP-based solutions.

Coupling sensitivity and radiation pattern of a vertical grating coupler.

Analytical expressions of electric field radiation pattern, coupling sensitivity, and scattering parameters of vertical grating couplers have been derived in this paper. Excellent agreement has been found between these expressions, finite element method (FEM) simulations, and experimental results. The results give an insight on how to design vertical grating couplers and reduce the number of iterations while designing and efficiently aligning the fiber over the chip without carrying out time-consuming electromagnetic simulations for the couplers.

Inkjet Printing of Magnetic Particles Toward Anisotropic Magnetic Properties.

Unique properties of one-dimensional assemblies of particles have attracted great attention during the past decades, particularly with respect to the potential for anisotropic magnetism. Patterned films can be created using inkjet printing; however, drying of particle-laden colloidal droplets on solid surfaces is usually accompanied by the well-known coffee-ring effect, deteriorating both the uniformity and resolution of the printed configurations. This study examines the effect of externally applied magnetic field on particle deposition patterns. Ferromagnetic Gd5Si4 particles were formulated in terpineol oil and directly deposited via magnetic field-assisted inkjet printing on a photopaper to generate patterned films with suppressed coffee-ring effect. The particle deposition morphology is determined by both solvent imbibition and particle-magnetic field interactions. Three characteristic times are considered, namely, the critical time for solvent imbibition into the substrate (tim), the time it takes for particles to form chains in the presence of the magnetic field (tch), and the time in which the particles reach the substrate in the direction normal to the substrate (tpz). The characteristic time ratios (tpz/tim) and (tpz/tch) determine the final deposition morphology in the presence of magnetic field. The ability to control particle deposition and assembly, thus tuning the magnetic anisotropic properties of nanostructured materials is a promising approach for many engineering applications.

Recycling of additively printed rare-earth bonded magnets.

In this work, we describe an efficient and environmentally benign method of recycling of additive printed Nd-Fe-B polymer bonded magnets. Rapid pulverization of bonded magnets into composite powder containing Nd-Fe-B particles and polymer binder was achieved by milling at cryogenic temperatures. The recycled bonded magnets fabricated by warm compaction of ground cryomilled coarse composite powders and nylon particles showed improved magnetic properties and density. Remanent magnetization and saturation magnetization increased by 4% and 6.5% respectively, due to enhanced density while coercivity and energy product were retained from the original additive printed bonded magnets. This study presents a facile method that enables the direct reuse of end-of-life bonded magnets for remaking new bonded magnets. In addition to magnetic properties, mechanical properties comparable to commercial products have been achieved. This research advances efforts to ensure sustainability in critical materials by forming close loop supply chain.

Comparative Analysis of Hemodynamic Changes and Shoulder Tip Pain Under Standard Pressure Versus Low-pressure Pneumoperitoneum in Laparoscopic Cholecystectomy.

BACKGROUND: Laparoscopic cholecystectomy is the gold standard procedure for cholelithiasis. Pneumoperitoneum is created using carbon dioxide (CO2) which is usually maintained at a range of 12-14 mm Hg. An emerging trend has been the use of low-pressure pneumoperitoneum in the range of 7-10 mm Hg in an attempt to lower the impact of pneumoperitoneum on the human physiology while providing adequate working space. Our study proposes to compare the effects of low-pressure pneumoperitoneum with the use of standard pressure of pneumoperitoneum. AIMS AND OBJECTIVE: To compare and analyze various factors like blood pressure, heart rate, end-tidal CO2 and postoperative shoulder tip pain in cases undergoing laparoscopic cholecystectomy using standard pressure versus low pressure. MATERIALS AND METHODS: This is a prospective randomized study carried out at Santosh Medical College and Hospitals, Ghaziabad from September 2017 to December 2018. This study included 60 patients of cholelithiasis which were divided into two groups of 30 patients each. Group I was offered laparoscopic cholecystectomy under standard pressure pneumoperitoneum and group II underwent laparoscopic cholecystectomy using low-pressure pneumoperitoneum. Patients in each group were evaluated for various intraoperative physiological changes and postoperative shoulder tip pain. OBSERVATIONS AND RESULTS: Cholelithiasis is commonly seen in middle-aged females. There is no significant difference in duration of surgery between the two groups. However, various factors like systolic blood pressure, heart rate, end-tidal CO2 were significantly better in the low-pressure group. Postoperative shoulder tip pain (measured by VAS scoring system) was significantly less in the low-pressure group during the first 24 hours. CONCLUSION: Laparoscopic cholecystectomy under low-pressure pneumoperitoneum causes minimal physiological changes and less postoperative shoulder tip pain. HOW TO CITE THIS ARTICLE: Goel A, Gupta S, et al. Comparative Analysis of Hemodynamic Changes and Shoulder Tip Pain Under Standard Pressure Versus Low-pressure Pneumoperitoneum in Laparoscopic Cholecystectomy. Euroasian J Hepatogastroenterol 2019;9(1): 5-8.

Luminescence properties of mechanochemically synthesized lanthanide containing MIL-78 MOFs.

Three metal-organic framework (MOF) compounds, Ln0.5Gd0.5{C6H3(COO)3}; Ln = Eu, Tb, and Dy with a MIL-78 structure, have been synthesized by a solvent-free mechanochemical method from stoichiometric mixtures of benzene 1,3,5-tricarboxylic acid, C6H3(COOH)3, also known as trimesic acid, and the respective lanthanide carbonates, Ln2(CO3)3·xH2O, Ln = Eu, Gd, Tb and Dy. MIL-78 (Ln0.5Gd0.5) shows the characteristic red, green, and yellow luminescence of Eu3+, Tb3+, and Dy3+, respectively. Efficient intramolecular energy transfer from the ligand triplet state to the excited states of Ln3+ ions can be observed. The lifetimes and quantum yields of these compounds are studied and discussed in detail. Among the three compounds, the Tb3+ containing compound shows the longest lifetime and highest quantum yield due to a smaller contribution from non-radiative decay pathways and better matching of the lowest triplet energy level of the benzenetricarboxylate ligand and the resonance level of Tb3+.

POSE: Prediction-Based Opportunistic Sensing for Energy Efficiency in Sensor Networks Using Distributed Supervisors.

This paper presents a distributed supervisory control algorithm that enables opportunistic sensing for energy-efficient target tracking in a sensor network. The algorithm called Prediction-based Opportunistic Sensing (POSE), is a distributed node-level energy management approach for minimizing energy usage. Distributed sensor nodes in the POSE network self-adapt to target trajectories by enabling high power consuming devices when they predict that a target is arriving in their coverage area, while enabling low power consuming devices when the target is absent. Each node has a Probabilistic Finite State Automaton which acts as a supervisor to dynamically control its various sensing and communication devices based on target's predicted position. The POSE algorithm is validated by extensive Monte Carlo simulations and compared with random scheduling schemes. The results show that the POSE algorithm provides significant energy savings while also improving track estimation via fusion-driven state initialization.

Wavelet-based information filtering for fault diagnosis of electric drive systems in electric ships.

Electric machines and drives have enjoyed extensive applications in the field of electric vehicles (e.g., electric ships, boats, cars, and underwater vessels) due to their ease of scalability and wide range of operating conditions. This stems from their ability to generate the desired torque and power levels for propulsion under various external load conditions. However, as with the most electrical systems, the electric drives are prone to component failures that can degrade their performance, reduce the efficiency, and require expensive maintenance. Therefore, for safe and reliable operation of electric vehicles, there is a need for automated early diagnostics of critical failures such as broken rotor bars and electrical phase failures. In this regard, this paper presents a fault diagnosis methodology for electric drives in electric ships. This methodology utilizes the two-dimensional, i.e. scale-shift, wavelet transform of the sensor data to filter optimal information-rich regions which can enhance the diagnosis accuracy as well as reduce the computational complexity of the classifier. The methodology was tested on sensor data generated from an experimentally validated simulation model of electric drives under various cruising speed conditions. The results in comparison with other existing techniques show a high correct classification rate with low false alarm and miss detection rates.

Innovative Economical Surgical Suture Board.

The aim of this study is to develop an economical suture board for practising suturing skills and techniques. Suture boards were made by using local electric boards, small leather patch, four suction buttons, six screws and a hook. These suture boards are multipurpose boards which are economical and available all the time in department for practicing. This board can also be placed in endotrainer for laparoscopic suturing skills. This economical suture board is cheap, easily available and helps in practicing various suturing and knot tying techniques.

Porcelain Gallbladder.

Porcelain gallbladder or calcified gallbladder is a rare entity and is considered as the end stage of chronic cholecystitis. This disease is rarely diagnosed preoperatively and usually mimics carcinoma gallbladder. Hereby, we present a rare and interesting case of porcelain gallbladder that was diagnosed preoperatively and managed by cholecystectomy. How to cite this article: Goel A, Agarwal A, Gupta S, Bhagat TS, Kumar G, Gupta AK. Porcelain Gallbladder. Euroasian J Hepato-Gastroenterol 2017;7(2):181-182.

Topological characterization and early detection of bifurcations and chaos in complex systems using persistent homology.

Early detection of bifurcations and chaos and understanding their topological characteristics are essential for safe and reliable operation of various electrical, chemical, physical, and industrial processes. However, the presence of non-linearity and high-dimensionality in system behavior makes this analysis a challenging task. The existing methods for dynamical system analysis provide useful tools for anomaly detection (e.g., Bendixson-Dulac and Poincare-Bendixson criteria can detect the presence of limit cycles); however, they do not provide a detailed topological understanding about system evolution during bifurcations and chaos, such as the changes in the number of subcycles and their positions, lifetimes, and sizes. This paper addresses this research gap by using topological data analysis as a tool to study system evolution and develop a mathematical framework for detecting the topological changes in the underlying system using persistent homology. Using the proposed technique, topological features (e.g., number of relevant k-dimensional holes, etc.) are extracted from nonlinear time series data which are useful for deeper analysis of the system behavior and early detection of bifurcations and chaos. When applied to a Logistic map, a Duffing oscillator, and a real life Op-amp based Jerk circuit, these features are shown to accurately characterize the system dynamics and detect the onset of chaos.

Towards Direct Synthesis of Alane: A Predicted Defect-Mediated Pathway Confirmed Experimentally.

Alane (AlH3 ) is a unique energetic material that has not found a broad practical use for over 70 years because it is difficult to synthesize directly from its elements. Using density functional theory, we examine the defect-mediated formation of alane monomers on Al(111) in a two-step process: (1) dissociative adsorption of H2 and (2) alane formation, which are both endothermic on a clean surface. Only with Ti dopant to facilitate H2 dissociation and vacancies to provide Al adatoms, both processes become exothermic. In agreement, in situ scanning tunneling microscopy showed that during H2 exposure, alane monomers and clusters form primarily in the vicinity of Al vacancies and Ti atoms. Moreover, ball milling of the Al samples with Ti (providing necessary defects) showed a 10 % conversion of Al into AlH3 or closely related species at 344 bar H2 , indicating that the predicted pathway may lead to the direct synthesis of alane from elements at pressures much lower than the 10(4)  bar expected from bulk thermodynamics.

Dry mechanochemical synthesis of alane from LiH and AlCl3.

A mechanochemical process for the synthesis of alane (AlH3) starting from lithium hydride (LiH) and aluminium chloride (AlCl3) at room temperature and the underlying reaction pathway have been studied. In contrast to a conventional process using the same two reactants dissolved in diethyl ether, our approach enables a solvent-free synthesis, thereby directly leading to adduct-free alane. The method described here is quick and efficient, resulting in the quantitative conversion of all aluminium in the starting mixture to alane. Both the intermediate compounds formed during the reaction and the final products have been characterized by powder X-ray diffraction, solid-state (27)Al NMR spectroscopy, and temperature programmed desorption analysis of the as-milled mixtures. We show that excess LiH in the starting mixture (with an optimal ratio of 9LiH : 1AlCl3) is essential for the formation and stability of Al-H bonds, initially in the form of alanates and, eventually, as alane. Further processing of this mixture, gradually adding AlCl3 to reach the ideal 3LiH : 1AlCl3 stoichiometry, appears to restrict the local accumulation of AlCl3 during the ball-milling process, thereby preventing the formation of unstable intermediates that decompose to metallic Al and molecular hydrogen. We also demonstrate that under the milling conditions used, a moderate hydrogen pressure of ca. 300 bar is required to suppress competing reactions that lead to the formation of metallic Al at room temperature. The identification of the reaction intermediates at each stage of the synthesis provides significant insight into the mechanism of this solid-state reaction, which may potentially afford a more rational approach toward the production of AlH3 in a simple solvent-free process.

Facile synthesis and regeneration of Mg(BH4)2 by high energy reactive ball milling of MgB2.

We report direct hydrogenation of MgB(2) in a planetary ball mill. Magnesium borohydride, Mg(BH(4))(2), and various polyhedral borane anion salts have been synthesized at pressures between 50 and 350 bar H(2) without the need for subsequent isothermal hydrogenation at elevated temperature and pressure. The obtained products release ∼4 wt% H(2) below 390 °C, and a major portion of Mg(BH(4))(2) transforms back to MgB(2) at around 300 °C, demonstrating the possibility of reversible hydrogen storage in an Mg(BH(4))(2)-MgB(2) system.

BaAu(x)Zn(13-x): electron-poor cubic NaZn13-type intermetallic and its ordered tetragonal variant.

Cubic NaZn(13)-type (Fm-3c, Z = 8) BaAu(x)Zn(13-x) compounds in the regions 1 ≤ x ≤ 5.4 (a = 12.418(1)-12.590(1) Å) and 6.4 ≤ x ≤ 8 (a = 12.630(1)-12.660(1) Å) plus an ordered tetragonal variant near x = 6 (P4/nbm; a = 8.8945(4) Å, c = 12.646(1) Å; Z = 4) have been synthesized and characterized by means of X-ray diffraction. Although the cubic structure contains Zn-centered, mixed (Zn, Au) icosahedra connected in alternate orientations via mixed tetrahedral stars (TS), the icosahedron vertices are ordered in the tetragonal structure. Both the inner and the outer tetrahedra in the TS in the cubic phase consist of mixed Au and Zn atoms, whereas the tetragonal phase features three different coloring schemes: inner Zn and outer Au tetrahedra, vice versa, or mixed Au and Zn sites on both inner and outer tetrahedra. Barium atoms center 24-atom snub cuboctahedra. Ordering of Au and Zn in the tetragonal phase achieves the largest number of heteroatomic Au-Zn contacts and yields relatively larger Hamilton populations (-ICOHPs) compared with homoatomic counterparts according to LMTO-based electronic structure calculations and analysis. Larger overlap populations are also observed for inter- versus intraicosahedral interactions. The densities-of-states data suggest the phase is metallic with highly dispersed Au d bands and nearly free-electron-like s and p bands for both Au and Zn.