Comparative study between functional outcome of lumbar canal stenosis treated with surgical decompression by laminectomy and unilateral partial hemi laminectomy approaches

Background: Lumbar spinal canal stenosis may eventually cause signs of intermittent neurogenic claudication. The surgical options include procedures such as midline decompression by laminectomy and different kinds of unilateral and bilateral fenestrations and partial or full hemi laminectomies. The aim of the study is to unilateral decompressive approach provides the sufficient decompression; less invasive unilateral procedure, which preserves posterior musculoligamentous complex and bony structures reduce associated morbidity.Methods: 41 patients underwent preoperative assessment of Japanese orthopaedic association score (JOA Score), Neurogenic claudication outcome scores (NCOS), visual analogy scale for back pain and neurogenic claudication. Patients were randomized to undergo either unilateral decompression by partial hemi laminectomy or CMD (CMD) by laminectomy. 20 patients was randomized into unilateral decompression by partial hemi laminectomy group and 21 patients into CMD (CMD) by laminectomy group.Results: The mean JOA recovery rate was 50.61% for the unilateral decompression group and 52.12% for the CMD group. Notably, 62% of CMD group had good or excellent outcome while 70% of unilateral decompression group had a good or excellent outcome.Conclusions: In our study, unilateral decompression by a partial hemi laminectomy provides minimal exposure for decompression in lumbar canal stenosis while preserving musculoligamentous attachments of the posterior elements of the spine and good postoperative results after one year with favorable outcomes of at least 70%.

Metallurgical analysis of SA-106 Gr. B pipe failure during hot bending

AbstractThis investigation deals with failure analysis of SA-106 Gr. B pipe which is a Carbon-Manganese steel used for moderately high temperature applications in industries. A transverse/ circumferential crack was formed in SA-106 Gr. B steel pipe during hot-bending operation. Visual examination and stereo-microscopic analysis indicated the presence of globules on the intrados surface of the pipe and towards the inner section on the crack surface. The globules had dendritic morphology which indicated the melting of the metal caused by temperature hike. Detailed analysis of the microstructure clearly indicated the presence of groups of inclusions. These inclusions coupled with over-stress due to sudden increase in temperature during induction heating led to the formation of cracks and caused failure of the pipe

Predicting long term performance of offshore wind turbines using cyclic simple shear apparatus

Offshore wind turbine (OWT) foundations are subjected to a combination of cyclic and dynamic loading arising from wind, wave, 1P (rotor frequency) and 2P/3P (blade passing frequency) loads. Under cyclic/dynamic loading, most soils change their characteristics. Cyclic behaviour (in terms of change of shear modulus change and accumulation of strain) of a typical silica sand (RedHill 110) was investigated by a series of cyclic simple shear tests. The effects of application of 50,000 cycles of shear loading having different shear strain amplitude, cyclic stress ratio (ratio of shear to vertical stress), and vertical stress were investigated. Test results were reported in terms of change in shear modulus against the number of loading cycles. The results correlated quite well with the observations from scaled model tests of different types of offshore wind turbine foundations and limited field observations. Specifically, the test results showed that; (a) Vertical and permanent strain (accumulated strain) is proportional to shear strain amplitude but inversely proportional to the vertical stress and relative density; (b) Shear modulus increases rapidly in the initial cycles of loading and then the rate of increase diminishes and the shear modulus remains below an asymptote. Discussion is carried out on the use of these results for long term performance prediction of OWT foundations

An innovative cyclic loading device to study long term performance of offshore wind turbines

One of the major uncertainties in the design of offshore wind turbines is the prediction of long term performance of the foundation i.e. the effect of millions of cycles of cyclic and dynamic loads on the foundation. This technical note presents a simple and easily scalable loading device that is able to apply millions of cycles of cyclic as well as dynamic loading to a scaled model to evaluate the long term performance. Furthermore, the device is economic and is able to replicate complex waveforms (in terms of frequency and amplitude) and also study the wind and wave misalignment aspects. The proposed test methodology may also suffice the requirements of Technology Readiness Level (TRL) Level 3–4 i.e. Experimental Proof of Concept validation as described by European Commission. Typical long term test results from two types of foundations (monopile and twisted jacket on piles) are presented to show the effectiveness of the loading device

Synthesis, growth and characterization of a nonlinear optical crystal: l-Leucinium perchlorate

An amino acid based semiorganic nonlinear optical family single crystal of l-leucinium perchlorate (LLPCl) was grown by the solvent evaporation method at ambient temperature. Good optical quality single crystals up to a size of 6 mm × 5 mm × 3 mm were obtained. The single-crystal XRD analysis shows that the grown crystals have a monoclinic structure. Fourier transform infrared (FTIR) spectral analysis and UV–vis spectral studies were also carried out. Microhardness mechanical studies show that the hardness number (Hv) of a LLPCl single crystal decreases with the load as measured by the Vickers microhardness method. The dielectric properties of the grown crystal were analysed by varying the frequency. Photoconductivity analysis gives the variation of the photocurrent and dark current. The nonlinear optical properties were studied using the Kurtz and Perry powder method and the second harmonic generation efficiency was found to be 2.6 times higher than that of KDP crystals

OPTIMIZATION OPTIMIZATION OF GROWTH PROMOTERS ON DESMODIUM GANGETICUM (L) DC USING RSM-CCD AND ITS ANTIOXIDANTS ACTIVITYOF GROWTH PROMOTERS ON DESMODIUM GANGETICUM (L) DC USING RSM-CCD AND ITS ANTIOXIDANTS ACTIVITY.

Objective: Desmodium gangeticum (Linn.) DC of Fabaceae is the vital plant used in ancient medicinal system of Ayurveda which was originated in India. This plant was reported to be a good result on cardiac system and nervous system. It has an ability to cures burning sensation, fever, cough, difficult breathing, dysentery, thirst and vomiting. D. gangeticum has also been reported to contain alkaloids, flavone and isoflavanoid glycosides. The plant has been reported to contain gangetin, a pterocarpnoid shown to possess anti-inflammatory and analgesic activities. The potent in vitro antioxidant activity of the 50% hydroalcoholic (total) extract. Phenolics are reported to be good antioxidant and anti-inflammatory agents. Since the plant under investigation is reported to contain both alkaloids and flavones along with isoflavanoid glycosides. The useful part is the root and it is an important ingredient in more than 50 Ayurvedic formulations like Chyavanaprasam, Dhanuantharam kuzhambu, Dasamularishtam etc. The objectives of the work is to optimize the maximum callus production by Desmodium ganageticum using response surface methodology (RSM) by developing an empirical model with different combination of Hormones and Growth promotes (IAA, IBA, BAP, and Kinetin) which were selected as the parameters. Methods: Different medium were screened for the maximum callus production and Murashige and Skoog was selected in which different range of hormones and growth promotes were added. The model evaluates the effect of each independent variable to a response. The mathematical relationship of the independent variables and the response can be calculated by the quadratic polynomial equation. The anti-oxidant activity was analyzed. Results: Models were developed by Central composite design (CCD) with the selected parameters. The regression analysis (R2) of RSM showed 97%. The optimal conditions for the maximal callus yield were IAA - 3, IBA - 0.5, BAP - 0.75 and Kinetin - 0.75.The work reported is a novel concept of combining the statistical modeling for an improved yield of callus of Desmodium gangeticum. The antioxidant activity of the intact plant compared which callus by superoxide scavenging, Hydroxy radical scavenging activity, Lipid peroxide assay, Nitric oxide radical inhibition activity. Conclusion: The development of rapid and efficient method for media preparation was established using RSM-CCD

Growth, optical and thermal studies of L-arginine perchlorate—A promising non-linear optical single crystal

524-528Optically good quality single crystal of L-arginine perchlorate (abbreviated as LARPCL), a promising analog of LAP was successfully grown by slow solvent evaporation technique at room temperature. The grown crystals were characterized by single crystal XRD, FTIR, FT-Raman, optical absorption and SEM studies. The thermal stability of the crystal was studied by TG, DTA and DSC analysis. The scanning electron microscopy (SEM) provides information about the surface morphology of the sample. The SHG efficiency is estimated using Kurtz powder method