Escorted Free Energy Simulations: Improving Convergence by Reducing Dissipation

Nonequilibrium, ``fast switching'' estimates of equilibrium free energy differences, Delta F, are often plagued by poor convergence due to dissipation. We propose a method to improve these estimates by generating trajectories with reduced dissipation. Introducing an artificial flow field that couples the system coordinates to the external parameter driving the simulation, we derive an identity for Delta F in terms of the resulting trajectories. When the flow field effectively escorts the system along a near-equilibrium path, the free energy estimate converges efficiently and accurately. We illustrate our method on a model system, and discuss the general applicability of our approach.Comment: 4 pages, including 2 figures, accepted for publication in Phys Rev Let

SPEECH RECOGNITION USING SOM AND ACTUATION VIA NETWORK IN MATLAB

This paper proposes a method of Speech recognition using Self Organizing Maps (SOM) and actuation through network in Matlab. The different words spoken by the user at client end are captured and filtered using Least Mean Square (LMS) algorithm to remove the acoustic noise. FFT is taken for the filtered voice signal. The voice spectrum is recognized using trained SOM and appropriate label is sent to server PC. The client and the server communication are established using User Datagram Protocol (UDP). Microcontroller (AT89S52) is used to control the speed of the actuator depending upon the input it receives from the client. Real-time working of the prototype system has been verified with successful speech recognition, transmission, reception and actuation via network

Amniotic membrane as a scaffold in wound healing and diabetic foot ulcer: an experimental technique and recommendations

Background: Human amniotic membrane has been used clinically in a variety of applications for over the past 100 years and produced a significant amount of data in multiple areas of medicine. Its clinical usage ranges from wound coverage for burn victims to healing of the conjunctiva after pterygium repair. The amniotic membrane natural properties provide an easy to use, safe option for various medical applications. There is need to develop a method for storage of amniotic membrane which can retain the biological properties and as well have long shelf life too.Methods: The experimental technique was standardized for cryopreservation of amniotic membrane. For this, amniotic membrane was obtained from mothers who had delivered through caesarean section with their consent.Results: The standardized protocol for cryopreservation of amniotic membrane was found to be safe and preserved amniotic membrane is expected to have long shelf life.  Conclusions: The advantages associated with amniotic membrane such as easily available, inexpensive, non-immunogenic and antimicrobial, anti-inflammatory properties make it a suitable graft to be used in wound healing and diabetic foot ulcers

HALL EFFECT OF CHEMICAL BATH DEPOSITED CdS THIN FILMS

ABSTRACT Thin films of CdS of different thickness have been prepared on glass substrates in various temperatures by Chemical bath deposition. The thickness of the films has been determined by quartz crystal monitor method. The Hall Effect and the electrical resistivity have been and continue to be the key parameters used in the investigations of the basic electrical conduction processes in semiconductor materials

ELECTRICAL PROPERTIES OF CHEMICAL BATH DEPOSITED CdS THIN FILMS

ABSTRAC

Assessment of (210)Po and (210)Pb in marine biota of the Mallipattinam ecosystem of Tamil Nadu, India.

To provide baseline data on background radiation levels for the future assessment of the impact of nuclear and thermal power stations, a systematic study was carried out in the Mallipattinam ecosystem of Tamil Nadu, India. Mallipattinam is located between the Kudankulam and Kalpakkam nuclear power plants and near to Tuticorin thermal power plant. Water, sediments, seaweeds, crustaceans, molluscs, and fish were collected to measure the concentrations of (210)Po and (210)Pb. The concentrations of (210)Po and (210)Pb in most samples are comparable to values reported worldwide. In fish, the concentrations of (210)Po and (210)Pb are in the range 16-190 Bq kg(-1) and 8-153 Bq kg(-1), respectively. The concentration factors of (210)Po and (210)Pb for the biotic components ranges from 10(3) to 10(6)

Direct synthesis and chemical vapor deposition of 2D carbide and nitride MXenes

Two-dimensional (2D) transition metal carbides and nitrides (MXenes) are a large family of materials actively studied for various applications, especially in the field of energy storage. MXenes are commonly synthesized by etching the layered ternary compounds, MAX phases. We demonstrate a direct synthetic route for scalable and atom-economic synthesis of MXenes, including phases that have not been synthesized from MAX phases, by the reactions of metals and metal halides with graphite, methane, or nitrogen. The direct synthesis enables chemical vapor deposition (CVD) growth of MXene carpets and complex spherulite-like morphologies that form through buckling and release of MXene carpet to expose fresh surface for further reaction. The directly synthesized MXenes showed excellent energy storage capacity for Li-ion intercalation.Comment: 9 pages, 4 figure

Natural radionuclide of Po210 in the edible seafood affected by coal-fired power plant industry in Kapar coastal area of Malaysia

<p>Abstract</p> <p>Background</p> <p>Po²¹⁰can be accumulated in various environmental materials, including marine organisms, and contributes to the dose of natural radiation in seafood. The concentration of this radionuclide in the marine environment can be influenced by the operation of a coal burning power plant but existing studies regarding this issue are not well documented. Therefore, the aim of this study was to estimate the Po²¹⁰concentration level in marine organisms from the coastal area of Kapar, Malaysia which is very near to a coal burning power plant station and to assess its impact on seafood consumers.</p> <p>Methods</p> <p>Concentration of Po²¹⁰was determined in the edible muscle of seafood and water from the coastal area of Kapar, Malaysia using radiochemical separation and the Alpha Spectrometry technique.</p> <p>Results</p> <p>The activities of Po²¹⁰in the dissolved phase of water samples ranged between 0.51 ± 0.21 and 0.71 ± 0.24 mBql^-1whereas the particulate phase registered a range of 50.34 ± 11.40 to 72.07 ± 21.20 Bqkg^-1. The ranges of Po²¹⁰activities in the organism samples were 4.4 ± 0.12 to 6.4 ± 0.95 Bqkg^-1dry wt in fish (<it>Arius maculatus</it>), 45.7 ± 0.86 to 54.4 ± 1.58 Bqkg^-1dry wt in shrimp (<it>Penaeus merguiensis</it>) and 104.3 ± 3.44 to 293.8 ± 10.04 Bqkg^-1dry wt in cockle (<it>Anadara granosa</it>). The variation of Po²¹⁰in organisms is dependent on the mode of their life style, ambient water concentration and seasonal changes. The concentration factors calculated for fish and molluscs were higher than the recommended values by the IAEA. An assessment of daily intake and received dose due to the consumption of seafood was also carried out and found to be 2083.85 mBqday^-1person^-1and 249.30 μSvyr^-1respectively. These values are comparatively higher than reported values in other countries. Moreover, the transformation of Po²¹⁰in the human body was calculated and revealed that a considerable amount of Po²¹⁰can be absorbed in the internal organs. The calculated values of life time mortality and morbidity cancer risks were 24.8 × 10^-4and 34 × 10^-4respectively which also exceeded the recommended limits set by the ICRP.</p> <p>Conclusions</p> <p>The findings of this present study can be used to evaluate the safety dose uptake level of seafood as well as to monitor environmental health. However, as the calculated dose and cancer risks were found to cross the limit of safety, finding a realistic way to moderate the risk is imperative.</p

Experimental studies on the effect of leading-edge tubercles on laminar separation bubble

An experimental investigation was carried out to study the influence of incorporating undulations (tubercles) at the leading edge of a NACA 4415 airfoil at a low Reynolds number of 120,000. Measurements were carried out at angles of attack of 6, 12, and 18 deg, which encompasses prestall (6 and 12 deg) and poststall (18 deg) regimes of the baseline, respectively. The aerodynamic performance of the NACA 4415 airfoil with leading-edge tubercles was compared against an airfoil without tubercles (baseline) through pressure measurements. Additionally, surface oilflow visualization and two-dimensional (2-D) particle image velocimetry (PIV) were carried out to obtain insight into the on-surface flow topology and off-body flowfield of the modified and baseline airfoils. At the lower angle of attack (a = 6 deg), the extent of the laminar separation bubble (in both length and height), which was the dominant flow feature over the baseline airfoil, was significantly altered by the presence of tubercles at the leading edge. The addition of tubercles resulted in the formation of pockets of smaller separation bubbles instead of one single long bubble spread along the span observed in the baseline airfoil. The 2-D PIV and oil-flow visualization results at an angle of attack of 18 deg prove that the tubercles are very much effective beyond the stall conditions of the baseline airfoil. The modified airfoil maintained attached flow until 50% of the chord, instead of complete separation starting from the leading edge, as noticed for the baseline case. The size of the recirculating zone downstream of the separation was also significantly reduced by the tubercles. All these factors contribute to the increased performance of the airfoil with leading-edge tubercles, especially at poststall angles of the baseline