bluuebunny/crossref_metadata_2025 huggingface dataset:
Performance of a Heat Pump Dehumidifier Dryer
Authors: Wongwises S. , Yoovidhaya T. , Supontana P. , Kaensup W.
Published: December 2014

In the present study, a heat pump dryer was designed and constructed. The performance of a heat pump assisted dryer was studied. The system was operated by using R22. The experimental data of the drying rates of shiitake mushroom was used to predict the specific moisture extraction rates (SMER). The maximum coefficient of performance (COP) of heat pump was also specified. The optimum operating condition was determined by the percentage of air recirculation from the total air mass flow rate. Finally, the key parameter that influence on the performance of the system and drying rate were specified.
Heat and Mass Transfer Characteristics in Consolidated Silica Gel/Water Adsorption–Cooling System
Authors: Yanagi Hideharu , Ino Nobumi
Published: December 2014

The heat and mass transfer on adsorption beds is decisive for the operational characteristics of adsorption refrigerators. To overcome its heat and mass transfer limitations a consolidated silica gel adsorption heat exchanger has been designed and successfully developed. It was made of composite as 4.3 wt% graphite, 86.4 wt% silica gel and binders, which was pressed into a heat exchanger module and then dried under a temperature of 90°C for 24 hours. With use of this adsorption heat exchanger, we measured an overall heat transfer coefficient of 62.2 W/m2K at the beginning of desorption cycle and 61.5 W/m2K during desorption, respectively. Whereas corresponding values of a granular silica gel bed were 44.8 W/m2K and 25.9 W/m2K, respectively.

This paper presents the operational characteristics of consolidated silica gel adsorption heat exchanger in refrigeration cycles, in addition to its isoster measurements for silica gel-water pair compared to that of the granular heat exchanger.
An Experimental Analysis on Energy Savings of VAV Systems in Hot and Humid Area
Authors: Yang K. H. , Lee S. K. , Yin H. C. , Wang Y. S. , Ting M. M.
Published: December 2014

Variable Air Volume (VAV) air-conditioning system presents great energy savings potential especially in hot and humid climate and has been recommended in the Building Energy Code of Taiwan since 1996. Simulation results indicated that the annual energy savings of VAV system in typical commercial buildings in Taiwan could be up to 70% of total fan power.

A full-scale experiment has been performed which validated this result successfully, and would be adapted with the PACS index in the second phase of national Building Energy Code in Taiwan.
An Application of Heat Pump for Infant Incubator
Authors: Kaensup Weerachai , Chutima Surachate
Published: December 2014

The purpose of this study is to develop an infant incubator that is efficient, simple to implement, and can be utilized especially in the rural area of Thailand. Instead of the current one which employed electrical heater, an electrical operated heat pump infant incubator is designed. The requirement of the air conditioning system to provided the room temperature lower than the desired temperature in the incubator (30–38 °C) in no longer needed. An electrical operated heat pump infant incubator using a simple four ways control valve will switch the incubator side to become evaporator when the ambient temperature is higher than the desired temperature and, in contrary, condenser in the when the ambient temperature is lower. A large mass heat exchanger attached to the indoor coils is desired to store energy sufficient that air temperature in the incubator would not drop lower than 0.5 °C from the set point between the compressor cut-out and cut-in. This application of heat pump could provided the opportunity for over six thousand small hospitals in the rural area of Thailand to employ the infant incubator.
A Comparative Study of Centrifugal Chiller Performances After CFC Refrigerant Conversion
Authors: Yang K. H. , Lee S. K. , Chiang Y. S. , Chen W. C. , Ting M. M.
Published: December 2014

Theoretical analysis indicated that, a typical centrifugal chiller could lose over 8% to 10% of its cooling capacity after converting from R-11 into using R-123 refrigerant. In this study, an attempt to recover some of this capacity loss by slightly decreasing its operating speed was analyzed.

A full-scale experiment was performed to change the gear train of a 300 RT centrifugal chillier, which validated that 3%∼6% capacity recovery could be expected. This is a break-through to promote the chiller conversion for wide engineering applications and is discussed in detail in this paper.
A Municipality Water Reticulation Ground-Coupled Reversible Heat Pump System as an Alternative to an Air Source System
Authors: Oerder S. , Meyer J. P.
Published: December 2014

A municipality water reticulation R22 ground-coupled reversible heat pump, was investigated as an alternative to conventional air source systems. The study covers the testing of a heating and cooling system that utilises the ground as its source. The ground source comprises of a municipality water supply line that is modified to allow water to flow through the outdoor coil thus delivering or extracting heat from the system. The investigation was conducted by developing analytical models that were used for the design of a ground-coupled reversible heat pump and a conventional, also reversible air-to-air system. The models were verified with a commercially available computer program as well as with measurements on the two systems. The results show an overall increase in performance with the use of a ground source system over the conventional air source systems. Thus the ground-coupled reversible heat pump system can provide a cost effective alternative to the more conventional air-to-air systems.
Performance Analysis of Combustion Engine Systems With a Packed Column CO2 Separator Using Aqueous Monoethanolamine (MEA) Solution
Authors: Ikame Masaru , Kan Susumu , Hiraoka Katsuhide , Kumakura Takanao
Published: December 2014

Systems analysis is performed for a diesel engine of the 10,000 kW class with CO2 recovery equipment using aqueous monoethanolamine solution on the basis of a CO2 mass transfer calculation model for a packed column.

The calculation model is based on the film theory, and gives calculation results in good accuracy, being compared with the experiments on CO2 absorption and on CO2 stripping.

The net output power of the engine reduces in order to recover the CO2 in the exhaust gas of the engine, and reduction of the output power depends on the ratio of the gas-to-liquid feed rate ratio of the stripper to that of the absorber. The operating parameters such as the stripping temperature, the highest loading factor, and the MEA concentration of the solution have an influence on the maximum attainable CO2 recovery ratio. The maximum attainable CO2 recovery ratio depends on the allowable level of the output power reduction, and with reduction of 10% of the engine output power, 70% of CO2 in the exhaust gas is recovered.
Rural Electrification Using Diesel Power Systems in Fiji: A Review
Authors: Prasad Surendra
Published: December 2014

For small developing countries such as Fiji being devoid of conventional energy resources such as petroleum products, coal or natural gas, there is always heavy, and in many cases total, reliance on conventional energy sources for transportation, industries and for electricity generation. Fiji, like most of its South Pacific island neighbours, has relied very heavily on petroleum products for all of these, except for electricity generation since 1983, when hydro-electricity became the major source of electricity for the country.
An Analytical Comparison Between the Performance of a Hot Water Heat Pump With a Non-Azeotropic Refrigerant Mixture and a Pure Refrigerant
Authors: Smit F. J. , Meyer Josua P.
Published: December 2014

The applications of hot water in the industrial, domestic and mining applications are numerous, and these are only a few of the core areas of use. In these applications fossil fuels and electrical resistance systems are usually used to heat water to temperatures near boiling point. The refrigerant R22, that is currently being used in hot water heat pumps, delivers hot water temperatures from 60 °C to 65 °C. This limits the applications of hot water heat pumps.

This analytical study uses three comparison methods to investigate and compare the potential of a non-azeotropic refrigerant mixture consisting of R22 and R142b. From the results different advantages of non-azeotropic refrigerant mixtures are evident. Depending on the application, if the results of a non-azeotropic refrigerant mixture are compared with a pure R22 heat pump, an increase in hot water temperatures to above boiling point, an increase in coefficient of performance, an increase in capacity and a decrease in compressor pressure ratio are possible. Unfortunately, not all these advantages are valid for each application. For instance, extremely high hot water temperatures are obtained, whilst the heating capacity is excessively low.
A GC2 Joining Procedure for B-Spline Patches in Reverse Engineering
Authors: Yang Tachung , Wang Cheng-Chung
Published: December 2014

Reconstruction of surface models is a vital part in reverse engineering. Because of the huge amount of data from Coordinate Measuring Machine (CMM), processes for division of data into groups, surface patch reconstruction, and patch joining are inevitable in the CAD systems tailored for reverse engineering applications. Existing techniques of surface patch joining have the disadvantages, such as computational complication or lack of desired geometric continuity. A GC2 joining technique for B-spline surface patches by utilising a Bezier patch joining technique was proposed in this paper. This method possesses the merits in which only the control vertices near the joining boundaries of patches are modified and no additional blending surfaces at the joints of patches are created.
A Predictor-Corrector Layerwise Model for Thick Laminated Composite Plates and Shells: Bending and Vibration
Authors: Lee K. H. , Cao L.
Published: December 2014

This paper describes a predictor-corrector theory based on a general higher-order layerwise model for the accurate prediction of the linear static and dynamic response of thick laminated composite plates and shells. The general polynomials introduced in the model account for the arbitrary variation of the transverse shear stresses across the thickness of each layer. The main purpose of the approach is to reduce the differences between the assumed variation of the transverse shear stresses provided by the constitutive equations and the computed variation of the same stresses from the equilibrium equations of elasticity. The present predictor-corrector layerwise model satisfies the continuity of the in-plane displacements and the transverse shear stresses at the interfaces. The numerical results for the bending and vibration of thick laminated composite plates and shells show that a high level of accuracy can be achieved with the same number of variables as that in Mindlin’s theory.
Vibration of Skew Sandwich Plates With Laminated Facings
Authors: Wang C. M. , Ang K. K. , Wang C.
Published: December 2014

A Rayleigh-Ritz analysis is presented for the free vibration of skew sandwich plates composed of an orthotropic core and laminated facings. By proposing a set of Ritz functions consisting of the product of mathematically complete polynomial functions and the the boundary equations raised to appropriate powers, the Rayleigh-Ritz method can be automated to handle such composite plates with any combination of edge conditions. For convenience and better accurarcy, the Ritz formulation was derived in the skew coordinate system. Vibration frequencies of rectangular plates (a special case of skew plates) obtained via this method have been found to be in good agreement with previous researchers results. Owing to length limitation, only sample vibration frequencies for skew sandwich plates are presented.
Modelling of Transient Slug Flow in Pipeline
Authors: Wong T. N. , Yau Y. K.
Published: December 2014

An approach to model slug flow in horizontal pipeline is presented which is based on a transient Lagrangian formulation. The effect of slug growth is modelled by considering the gas expansion, picking up of liquid film ahead of the slug and shading of liquid from the slug tail. This method is particular useful for slug flows approaching the end of a pipeline. The validation of the theoretical prediction is confirmed by comparing with the experimental measurement. The proposed model is further used to analyse shock phenomenon caused by a rapid valve closure in a gas-liquid slug flows system. The results show that the pressure surge is highly dependent on the local void fraction at the valve during closure. Good agreement has been obtained between prediction and experimental data by Akagawa et al (1982).
Fluid Transient Responses With Check Valves in Pipe Flow System With Air Entrainment
Authors: Lee T. S. , Leow L. C.
Published: December 2014

A common flow system arrangement in piping system consists of a lower reservoir, a group of pumps with a check valve in each branch, and a pipeline discharging into a upper reservoir. In earlier studies of check valves performances in transient flow, none considered the effects of air entrainment into a pipeline system and the subsequent effects on the check valve performances in transient flow. Studies on pressure surges during pump tripped in pumping systems showed that by including an air entrainment variable wave speed model, reasonable predictions of fluid transient responses with proper phasing and attenuation of pressure peaks can be obtained. The most severe case where all the pumps in the station fail simultaneously due to power failure was analysed for their maximum and minimum pressure variation along the pipeline. A numerical model is now set up in the present work to investigate the check valve performances in transient flow for a pumping system with air entrainment. The analyses examine a fluid system with a variable air entrainment content (ε) and studied numerically it effects on the flow reversal time and hence determine the appropriate valve selection for a given fluid system to minimize problems of check valve slamming. Present numerical computations show that the air content in a fluid system can adversely affect the check valve transient responses. With the fluid system operating within a critical range of air entrainment values, analysis showed that there is a possibility of “check valve slamming” when the check valves were selected based on the analysis of an air free system. The above phenomena is confirmed through physical field measurements.
Ultrasonic Spectroscopy for Simulated Plastic IC Packages
Authors: Joshi Narayan R.
Published: December 2014

Failure analysis of integrated circuit (IC) packages is a critical element for in house quality control and for problems encountered in service. Plastic IC packages are routinely inspected for delaminations, voids, cracks, and corrosion using the C-mode acoustic microscopy (C-AM). Plastic IC packages are hygroscopic and can absorb moisture subjected to environmental cycling depending on the quality of the plastic chemical compound used to encapsulate the IC chip. The new advanced ultrasonic interference spectroscopy (UIS) technique used by the author elsewhere to detect presence of moisture in adhesively bonded joints is applied to the problems of the plastic IC packages in this research work. The new UIS technique was used on manually fabricated simulated plastic packages with thin water film trapped between two layers of plastic material (Lexan) and the silicon wafer. The technique successfully detected the presence of an extra water layer in the assembly inspected and estimated its thickness accurately to be 110 μm. At present the technique is under development for detection of water films thinner than 110 μm in actual plastic IC packages.
Progress and Challenges in Droplets and Spray Combustion
Authors: Chiu H. H.
Published: December 2014

Recent theoretical developments in droplet and spray combustion have been reviewed with due emphasis placed upon the modern interpretation of phenomena and the elucidation of unified theoretical approaches and the foundation of concepts in the area of selected outstanding problems previously identified. Universal laws of a droplet for a dilute and a non-dilute spray, developed recently by the techniques of canonical integration and renormalizaton, offer remarkably broad based knowledge and quantitative prediction of droplet exchange rates in a general hydrodynamic environment. The phenomena and criteria of state transition and the principles of partition of gasification among all the major subprocesses at the transition state are presented. Also reviewed is the multi-state behavior of an isolated converting droplet in the critical ranges of Reynolds number and Damkohler number. Recent experimental validations of group combustion phenomena in laminar sprays and turbulent premixed sprays are presented and the concept of hierarchical group combustion in practical liquid sprays are discussed. Emerging interest in the large scale structures, featured by inhomogeneous local clustering and declustering of droplets in liquid sprays are presented. Various mechanisms of the formation of complex configurations of structures are identified and theoretical categorization based on hierarchical distribution functions are proposed. Kinetic theoretic approach of many-droplet system based on Born, Bogoliuvob, Green Kirkwood, and Yvon’s hierarchy is extended for the classification of structural configuration and the predictions of the dynamic evolution as well as the exchange of scalar and vectorial properties are discussed.
Coal-Fired Magnetohydrodynamic Power Plant With Zero-CO2 Atmospheric Emission
Authors: Iantovski E. , Lhomme R. , Mathieu Ph.
Published: December 2014

In this system, an MHD generator is used instead of a gas turbine. The cycle efficiency is reaching 50%. The system is based on a cycle using CO2 as the working fluid and oxygen as oxidant. The fuel is pulverized coal. All the pollutants, including the CO2 produced in the combustion process, are fully removed and diposed of. This highly pressurized excess CO2 is easily separated from the working fluid without any costly and energy consuming device and, being in liquid state, is ready for transportation and disposal or possibly reuse in other applications.

The most important parameter determining the cycle efficiency is shown to be the isentropic effectiveness of the MHD expander. This latter is depending, on the one hand, on the design of the channel and on the other hand, on the conductivity of the gases which can be optimized with respect to the cycle parameters.

In conclusion, the assets of the proposed system are high performance and no pollutant releases. As a consequence, MHD generators may be considered as viable options for coal-firing and possible competitors of advanced coal-based plants. One of the spin-off of this study is the possible revival of existing MHD facilities.
Simulation of Mechanical and Thermodynamic Performances of a Ship Propulsion Plant in Transient Conditions
Authors: Carrera Giovanni , Rizzuto Enrico
Published: December 2014

The paper presents a numerical procedure for the simulation of a marine propulsion plant in transient conditions: the model describes in detail the various elements of the propulsion system and the interactions existing between each of them.

The thermodynamic behaviour of the main engine as well as of the turbocharger group is modelled, in order to predict not only the mechanical stress of the plant due to the transient conditions, but also the thermal stresses and working point of the compressor and of the turbine (pressure and temperature at inlet/outlet).

As a first application of the model, the case is considered of a twin screw vessel powered by two four stroke medium speed diesel engines with controllable pitch propellers. The simulations presented in the paper regard two transient manoeuvres of the ship: slam-start (from zero speed to full ahead) and crash stop (from full ahead to zero speed with a “full astern” command).

The results of the simulations are compared with the available experimental data, regarding the time histories of the vessel speed, space run before a complete stop, propeller r.p.m. and shaft power, showing a good accordance.

The procedure can be utilised to check the behaviour of the turbocharger group during a transient manoeuvre and to identity possible improvements in the ship control system or in the pitch-r.p.m. combination law to optimise the performances, in term of e.g. stopping space of the vessel or thermal and mechanical stresses of the plant.
Brayton Cycle Optimization
Authors: Mitra Sushanta K. , Mukhopadhaya Achintya
Published: December 2014

The Brayton Cycle is the ideal cycle for simple gas turbine applications. The heat transfer process in such a cycle is of practical importance as far as power output is considered. The present work focusses on the power output from an ideally reversible Brayton cycle and criteria for optimum power based on its operating parameters like the specific heat of hot and cold fluids, working fluid and heater inlet temperature is discussed here.
Synthesis of Multi-Body Systems for Desired Eigenfrequencies
Authors: Esat Ibrahim I. , Akbar Shahzad
Published: December 2014

The eigenvalues in the modal co-ordinate frame are varied and the corresponding changes in the stiffness matrix is investigated. To represent the modified eigenvalues as a function of the stiffness matrix is the main focus of this paper. It is shown that the change in eigenvalue is proportional to the change in the stiffness matrix. This approach may be applied to shift certain natural frequencies of a structure away from the critical operating frequency by structural modification.
Free Undamped Vibration of Geometrically Non-Linear Cable Structures
Authors: Kwan Alan S. K.
Published: December 2014

The stiffness relationship and the distributed mass matrix for a geometrically nonlinear three dimensional straight axial element is derived for use in prestressed cablenet structures. The justification for the use of a linearised stiffness relationship is provided through a theoretical derivation. Results using this simple element have shown a high degree of correlation with results to those available in the literature obtained with more complex curved finite elements, analogous membrane models and other techniques.
Buckling of Circular Plates Based on Reddy Plate Theory
Authors: Wang C. M. , Lee K. H. , Reddy J. N.
Published: December 2014

Treated herein is the elastic buckling of circular plates based on the Reddy plate theory. This plate theroy extends the Kirchhoff (or the classical thin) plate theory to allow for the effect of transverse shear deformation. Unlike the Mindlin’s shear deformation plate theory, there is no need for a shear correction factor in the Reddy plate theory. In this paper, exact buckling solutions are derived for circular plates whose edges are simply supported and elastically restrained against rotation as well. This general edge condition includes the classical simply supported and clamped edges at the limiting, values of the elastic rotational restraint constant. The buckling solutions are expressed in terms of the well-known Kichhoff buckling solutions. A comparison of buckling loads between the Mindlin, Reddy and three-dimensional elasticity plates is also given.
Application of the GT35 Industrial Gas Turbine for the Propulsion of Fast Ferries
Authors: Svensson Bo S.
Published: December 2014

The paper describes the modifications required to make the GT35 industrial gas turbine suitable for use in fast ferries as propulsion machinery. The modifications made to get the unit to meet pitch and roll requirements are dealt with, as well as the engine support system modifications.

The GT35’s capability to burn low quality, liquid fuels is discussed, and a close look is taken at the effect such fuel has on the life of the unit and the time between service.

In order to facilitate power production on the ship, the GT35 has been equipped with a starting motor which during operation is used as a shaft driven generator. The generator is driven by the low pressure rotor. Each generator can produce 500 kW, which means 1000 kW for the ferry. The effect of the arrangement on the rotor system behavior is described.

At the time of writing this paper ABB has sold 6 GT35 units for operation in 3 fast ferries. The speed of the ferries varies between 40 knots and 60 knots. At the time of writing this paper, the first of the two HSS 900 ferries for Stena Line, Sweden, has just completed its first set of sea trials.
Computational and Experimental Study of Turbulent Flow Past an Array of Bluff Bodies Aligned Along the Channel Axis
Authors: Liou Tong-Miin , Chen Shih-Hui
Published: December 2014

Computations and measurements of time mean velocities, total fluctuation intensities, and Reynolds stresses are presented for spatially periodic flows past an array of bluff bodies aligned along the channel axis. The Reynolds number based on the channel hydraulic diameter and cross-sectional bulk mean velocity, the pitch to rib-height ratio, and the rib-height to channel-height ratio were 2 × 104, 10, and 0.133, respectively. The unsteady phase-averaged Navier-Stokes equations were solved using a Reynolds stress model with wall function and wall-related pressure strain treatment to reveal the feature of examined unsteady vortex shedding flow. Laser Doppler velocimetry measurements were performed to measure the velocity filed. Code verifications were performed through comparisons with others’ measured developing single-rib flow and our measured fully developed rib-array flow. The computed results and measured data are found in reasonable agreement, which justifies the turbulence model adopted. The calculated phase-averaged flow field clearly displays the vortex shedding behind the rib and is characterized in terms of shedding Strouhal number, vortex trajectory, vortex celerity, and vortex travelling distance in a phase cycle. Furthermore, the difference between the computed developing single-rib flow and fully developed rib-array flow is addressed.
Limiting the Maintenance Impact of Frequency Regulation Duty on Simple and Combined Cycle Gas Turbine Power Plants
Authors: Rowen William I.
Published: December 2014

As more new power plants based on gas turbines enter service, the need for these plants to participate in grid frequency regulation, as opposed to providing blocks of base load power on a dispatchable basis, increases dramatically, exposing this equipment to the potential for accelerated thermal fatigue duty. This paper proposes a methodology for quantifying and limiting the maintenance impact of rapid load changes imposed on gas turbines when required to provide frequency regulation service to the connected utility.

The paper includes a discussion of the need for prime movers to participate in system frequency regulation and the impact of this type of service on gas turbine operation. The physics of thermally induced low cycle fatigue is then discussed, and the relationships are quantified using a multiple time constant approach that provides guidance for estimating the transient thermal characteristics of the turbine airfoils that are susceptible to thermally induced low cycle fatigue. This is used to develop the thermo-mechanical relationships that are pertinent to gas turbines in generator drive service. Finally, this material is related back to operational considerations in utilizing gas turbines for system frequency regulation duty.
Effect of Rib Size on Heat (Mass) Transfer Distribution in a Rotation Channel
Authors: Park C. W. , Kukreja R. T. , Lau S. C.
Published: December 2014

Experiments have been conducted to study the effect of rib size on the local heat (mass) transfer distribution for radial outward flow in a rotating channel with transverse ribs on the leading and trailing walls. The test channel modeled internal turbine blade cooling passages. Results were obtained for Reynolds numbers of 5,500 and 10,000, rotation numbers of 0.09 and 0.24, and for a fixed rib pitch that was equal to the channel hydraulic diameter. For a fixed rib configuration on the leading wall, increasing the size of the ribs on the trailing wall increased the heat (mass) transfer on the leading wall. Ribs with D/e = p/e = 16 on the trailing wall performed better than ribs with D/e = p/e = 10. When the rotation number was large, the heat (mass) transfer on the leading wall was quite low, regardless of the sizes of the ribs on the leading and trailing walls. There was very little spanwise variation of the local heat (mass) transfer between the transverse ribs on the trailing wall. When the rotation number was large, however, there was a significant spanwise variation of the local heat (mass) transfer between ribs on the leading wall.
Advancements in Machinery Management Using the Measurement of Rotor Torsional Response
Authors: Thomson Alan S.
Published: December 2014

Rotor torsional (angular, steady and dynamic) motion, in response to the interaction of torque and torsional/lateral cross coupled forces with torsional dynamic stiffness, exist in rotating and reciprocating machinery for many reasons. The dynamic torsional response however, is commonly not measured on a continual basis. In the torsional dynamic stiffness, damping parameters are generally several magnitudes weaker than their lateral counterpart. This yields the opportunity for torsional responses, especially when exciting a resonance, to produce relatively large deflections and corresponding stresses, sometimes large enough to cause machine failure.

Due to their rigid coupling, long shaft system lengths (a series of shafts coupled together), and large polar moments of inertia, the turbomachinery used in the power generation industry are particularly sensitive to forced torsional excitation. The forcing can come from many sources, including lateral forces which cross couple into torsional forces. Recent research introduces new sources of cross coupled excitation and a method to indirectly measure their and other effects on the mechanical integrity of the mechanical system.

A modified and a prototype technique for continuously measuring directly and indirectly the rotor torsional response, and using it to evaluate rotor torsional dynamic stiffness as a machinery management tool is discussed in this paper.
Reverse Engineered Part Development
Authors: Simandiri Sim S. , Wang K. H.
Published: December 2014

Reverse engineering proceeds in the reverse of conventional manufacturing order, based on the pull system instead of the traditional push system. This paper is concerned with applying the reverse engineering concept to the development of parts. With this procedure the development of parts involves an iterative reverse process from the scanning of a developmental prototype towards the design model.

The focus is on the use of two set-ups of network in providing computerized data of the prototype that are exchangeable among Computer-Aided Design (CAD) and Computer-Aided Manufacturing (CAM) systems. The first set-up applies a direct approach to manipulate the scanned data in the CAM environment for generating Numerical Control (NC) programs used for machining the workpiece. The second set-up applies an indirect approach to manipulate the scanned data in a CAD environment prior to generating the NC programs. The major benefits gained from the reverse engineering application in the development of parts are also described.
A New Gas Turbine Cycle for Economical Power Boosting
Authors: Utamura Motoaki , Takehara Isao , Horii Nobuyuki , Kuwahara Takaaki
Published: December 2014

A Moisture Air Turbine (MAT) cycle is proposed for improving the characteristics of land based gas turbine by injecting atomized water at inlet to compressor.

The power boosting mechanism of MAT is understood as composits of those of following existing systems: inlet air cooling system, inter-cooling and steam injection. Experiments using a 15MW class axial flow load compressor have been carried out to reveal that water evaporation in compressor could reduce compressor work in an efficient manner. Moreover, this technology has been demonstrated by means of 130MW class simple cycle gas turbine power plant to show that a small amount of water consumption is sufficient to increase power output. Very efficient evaporation could be achieved provided the size of water droplet is controlled properly. The amount of water consumption is much less than that of conventional inlet air cooling system with cooling tower for heat rejection.

Incorporating water droplet evaporation profile into consideration, realistic cycle calculation model has been developed to predict power output with water injection.

It has been shown that this technology is economically achievable. It should be stressed that contrary to well known evaporative cooler, MAT cycle could provide power output at a desired value within its capability regardless of ambient humidity condition.
Droplet Combustion With Radiative Heat Transfer
Authors: Chang S. S. , Chiu H. H. , Lee T. S.
Published: December 2014

Combustion of a droplet, either in stationary or convective motion under the effect of radiative heat transfer is studied. The closed form expression of gasification laws and the radiative flux distribution surrounding a stationary droplet are calculated using Potential Theory of Radiation in conjunction with the canonical theory of droplet recently developed. Various mechanisms contributing to gasification rate of a combusting droplet under radiative condition are determined by the Canonical Integral Method to assess their importance. It is found that radiation effect plays an important role when the droplet considered is of large size and under high environmental temperature. It is seen from the present study that for a typical application in turbine combustor, the enhancement of droplet combustion rate due to radiation ranges from 5 percents to 15 percents depending on the droplet size and the environmental conditions.
Clavanin A Improves Outcome of Complications from Different Bacterial Infections
Authors: Silva Osmar N. , Fensterseifer Isabel C. M. , Rodrigues Elaine A. , Holanda Hortência H. S. , Novaes Natasha R. F. , Cunha Junia P. A. , Rezende Taia M. B. , Magalhães Kelly G. , Moreno Susana E. , Jerônimo Márcio S. , Bocca Anamélia L. , Franco Octavio L.
Published: December 2014

The rapid increase in the incidence of multidrug-resistant infections today has led to enormous interest in antimicrobial peptides (AMPs) as suitable compounds for developing unusual antibiotics. In this study, clavanin A, an antimicrobial peptide previously isolated from the marine tunicate
Styela clava
, was selected as a purposeful molecule that could be used in controlling infection and further synthesized. Clavanin A was
in vitro
evaluated against
Staphylococcus aureus
and
Escherichia coli
as well as toward L929 mouse fibroblasts and skin primary cells (SPCs). Moreover, this peptide was challenged here in an
in vivo
wound and sepsis model, and the immune response was also analyzed. Despite displaying clear
in vitro
antimicrobial activity toward Gram-positive and -negative bacteria, clavanin A showed no cytotoxic activities against mammalian cells, and in acute toxicity tests, no adverse reaction was observed at any of the concentrations. Moreover, clavanin A significantly reduced the
S. aureus
CFU in an experimental wound model. This peptide also reduced the mortality of mice infected with
E. coli
and
S. aureus
by 80% compared with that of control animals (treated with phosphate-buffered saline [PBS]): these data suggest that clavanin A prevents the start of sepsis and thereby reduces mortality. These data suggest that clavanin A is an AMP that could improve the development of novel peptide-based strategies for the treatment of wound and sepsis infections.
Effect of Reduced Oxygen on the Antifungal Susceptibility of Clinically Relevant Aspergilli
Authors: Binder Ulrike , Maurer Elisabeth , Lackner Michaela , Lass-Flörl Cornelia
Published: December 2014

The influence of hypoxia on the
in vitro
activities of amphotericin B, azoles, and echinocandins against
Aspergillus
spp. was evaluated by comparing MICs, minimal fungicidal concentrations (MFCs), and epidemiological cutoffs (ECOFFs). Changes of MIC distributions due to hypoxia largely depend on the method, the species, and the growth ability under hypoxia. The activities of antifungals were not significantly altered under hypoxia, except for
Aspergillus terreus
, for which the activity changed from fungicidal to fungistatic.
Rapid Testing Using the Verigene Gram-Negative Blood Culture Nucleic Acid Test in Combination with Antimicrobial Stewardship Intervention against Gram-Negative Bacteremia
Authors: Bork Jacqueline T. , Leekha Surbhi , Heil Emily L. , Zhao LiCheng , Badamas Rilwan , Johnson J. Kristie
Published: December 2014

Rapid identification of microorganisms and antimicrobial resistance is paramount for targeted treatment in serious bloodstream infections (BSI). The Verigene Gram-negative blood culture nucleic acid test (BC-GN) is a multiplex, automated molecular diagnostic test for identification of eight Gram-negative (GN) organisms and resistance markers from blood culture with a turnaround time of approximately 2 h. Clinical isolates from adult patients at the University Maryland Medical Center with GN bacteremia from 1 January 2012 to 30 June 2012 were included in this study. Blood culture bottles were spiked with clinical isolates, allowed to incubate, and processed by BC-GN. A diagnostic evaluation was performed. In addition, a theoretical evaluation of time to effective and optimal antibiotic was performed, comparing actual antibiotic administration times from chart review (“control”) to theoretical administration times based on BC-GN reporting and antimicrobial stewardship team (AST) review (“intervention”). For organisms detected by the assay, BC-GN correctly identified 95.6% (131/137), with a sensitivity of 97.1% (95% confidence interval [CI], 90.7 to 98.4%) and a specificity of 99.5% (95% CI, 98.8 to 99.8%). CTX-M and OXA resistance determinants were both detected. Allowing 12 h from Gram stain for antibiotic implementation, the intervention group had a significantly shorter duration to both effective (3.3 versus 7.0 h;
P
< 0.01) and optimal (23.5 versus 41.8 h;
P
< 0.01) antibiotic therapy. BC-GN with AST intervention can potentially decrease time to both effective and optimal antibiotic therapy in GN BSI.
Cardiac Effects of Echinocandins after Central Venous Administration in Adult Rats
Authors: Koch Christian , Uhle Florian , Wolff Matthias , Arens Christoph , Schulte Astrid , Li Ling , Niemann Bernd , Henrich Michael , Rohrbach Susanne , Weigand Markus A. , Lichtenstern Christoph
Published: December 2014

Echinocandins have become the agents of choice for early and specific antifungal treatment in critically ill patients.
In vitro
studies and clinical case reports revealed a possible impact of echinocandin treatment on cardiac function. The aim of our study was to evaluate echinocandin-induced cardiac failure. Using an
in vivo
rat model, we assessed hemodynamic parameters and time to hemodynamic failure after central venous application (vena jugularis interna) of anidulafungin (low-dose group, 2.5 mg/kg body weight [BW]; high-dose group, 25 mg/kg BW), caspofungin (low-dose group, 0.875 mg/kg BW; high-dose group, 8.75 mg/kg BW), micafungin (low-dose group, 3 mg/kg BW; high-dose group, 30 mg/kg BW), and placebo (0.9% sodium chloride). Left ventricular heart tissue was collected to determine mitochondrial enzyme activity via spectrophotometric measurements. mRNA expression of transcriptional regulators and primary mitochondrial transcripts, mitochondrial DNA (mtDNA) content, and citrate synthase activity were also explored. Animals receiving high-dose anidulafungin or caspofungin showed an immediate decrease in hemodynamic function. All of the subjects in these groups died during the observation period. Every animal in the untreated control group survived (
P
< 0.001). Hemodynamic failure was not noticed in the anidulafungin and caspofungin low-dose groups. Micafungin had no impact on cardiac function. In analyzing mitochondrial enzyme activity and mitochondrial transcripts, we found no association between echinocandin administration and the risk for hemodynamic failure. Further experimental studies are needed to elucidate the underlying mechanisms involved in cardiotoxic echinocandin effects. In addition, randomized controlled clinical trials are needed to explore the clinical impact of echinocandin treatment in critically ill patients.
Ability of Hydroxypropyl Chitosan Nail Lacquer To Protect against Dermatophyte Nail Infection
Authors: Ghannoum M. A. , Long L. , Isham N. , Bulgheroni A. , Setaro M. , Caserini M. , Palmieri R. , Mailland F.
Published: December 2014

The development of a topical agent that would strengthen the nail, improve the natural barrier, and provide better drug penetration to the nail bed is needed. In this study, we examined the effects of a hydroxypropyl chitosan (HPCH)-based nail solution using a bovine hoof model. Following application of the nail solution, changes in the hardness of the hoof samples were measured using the Vickers method. Tensile and flexural strengths were tested by stretching or punching the samples, respectively. The ultrastructure was examined using scanning electron microscopy (SEM), and samples stained with periodic acid-Schiff (PAS) stain were used to determine the fungal penetration depth. The comparators included 40% urea and 70% isopropyl alcohol solutions. The HPCH nail solution increased hoof sample hardness in comparison to the untreated control sample (mean, 22.3 versus 19.4 Vickers pyramid number [HV]). Similarly, the HPCH solution increased the tensile strength (mean, 33.07 versus 28.42 MPa) and flexural strength (mean, 183.79 versus 181.20 MPa) compared to the untreated control. In contrast, the comparators had adverse effects on hardness and strength. SEM showed that the HPCH solution reduced the area of sample crumbling following abrasion compared to the untreated control (7,418 versus 17,843 pixels), and the PAS-stained images showed that the HPCH solution reduced penetration of the dermatophyte hyphae (e.g., penetration by
Trichophyton mentagrophytes
was <25 μm at day 9 versus 275 μm in the untreated control). Unlike chemicals normally used in cosmetic treatments, repeated application of the HPCH nail solution may help prevent the establishment of new or recurring fungal nail infection.
The Mannitol Utilization System of the Marine Bacterium Zobellia galactanivorans
Authors: Groisillier Agnès , Labourel Aurore , Michel Gurvan , Tonon Thierry
Published: December 2014

Mannitol is a polyol that occurs in a wide range of living organisms, where it fulfills different physiological roles. In particular, mannitol can account for as much as 20 to 30% of the dry weight of brown algae and is likely to be an important source of carbon for marine heterotrophic bacteria.
Zobellia galactanivorans
(
Flavobacteriia
) is a model for the study of pathways involved in the degradation of seaweed carbohydrates. Annotation of its genome revealed the presence of genes potentially involved in mannitol catabolism, and we describe here the biochemical characterization of a recombinant mannitol-2-dehydrogenase (M2DH) and a fructokinase (FK). Among the observations, the M2DH of
Z. galactanivorans
was active as a monomer, did not require metal ions for catalysis, and featured a narrow substrate specificity. The FK characterized was active on fructose and mannose in the presence of a monocation, preferentially K
+
. Furthermore, the genes coding for these two proteins were adjacent in the genome and were located directly downstream of three loci likely to encode an ATP binding cassette (ABC) transporter complex, suggesting organization into an operon. Gene expression analysis supported this hypothesis and showed the induction of these five genes after culture of
Z. galactanivorans
in the presence of mannitol as the sole source of carbon. This operon for mannitol catabolism was identified in only 6 genomes of
Flavobacteriaceae
among the 76 publicly available at the time of the analysis. It is not conserved in all
Bacteroidetes
; some species contain a predicted mannitol permease instead of a putative ABC transporter complex upstream of M2DH and FK ortholog genes.
A Chlorogenic Acid Esterase with a Unique Substrate Specificity from Ustilago maydis
Authors: Nieter Annabel , Haase-Aschoff Paul , Kelle Sebastian , Linke Diana , Krings Ulrich , Popper Lutz , Berger Ralf G.
Published: December 2014

An extracellular chlorogenic acid esterase from
Ustilago maydis
(UmChlE) was purified to homogeneity by using three separation steps, including anion-exchange chromatography on a Q Sepharose FF column, preparative isoelectric focusing (IEF), and, finally, a combination of affinity chromatography and hydrophobic interaction chromatography on polyamide. SDS-PAGE analysis suggested a monomeric protein of ∼71 kDa. The purified enzyme showed maximal activity at pH 7.5 and at 37°C and was active over a wide pH range (3.5 to 9.5). Previously described chlorogenic acid esterases exhibited a comparable affinity for chlorogenic acid, but the enzyme from
Ustilago
was also active on typical feruloyl esterase substrates. Kinetic constants for chlorogenic acid, methyl
p
-coumarate, methyl caffeate, and methyl ferulate were as follows:

K
m

values of 19.6 μM, 64.1 μM, 72.5 μM, and 101.8 μM, respectively, and
k
cat
/

K
m

values of 25.83 mM
−1
s
−1
, 7.63 mM
−1
s
−1
, 3.83 mM
−1
s
−1
and 3.75 mM
−1
s
−1
, respectively. UmChlE released ferulic,
p
-coumaric, and caffeic acids from natural substrates such as destarched wheat bran (DSWB) and coffee pulp (CP), confirming activity on complex plant biomass. The full-length gene encoding UmChlE consisted of 1,758 bp, corresponding to a protein of 585 amino acids, and was functionally produced in
Pichia pastoris
GS115. Sequence alignments with annotated chlorogenic acid and feruloyl esterases underlined the uniqueness of this enzyme.
Exploring the Diversity of Listeria monocytogenes Biofilm Architecture by High-Throughput Confocal Laser Scanning Microscopy and the Predominance of the Honeycomb-Like Morphotype
Authors: Guilbaud Morgan , Piveteau Pascal , Desvaux Mickaël , Brisse Sylvain , Briandet Romain
Published: December 2014

Listeria monocytogenes
is involved in food-borne illness with a high mortality rate. The persistence of the pathogen along the food chain can be associated with its ability to form biofilms on inert surfaces. While most of the phenotypes associated with biofilms are related to their spatial organization, most published data comparing biofilm formation by
L. monocytogenes
isolates are based on the quantitative crystal violet assay, which does not give access to structural information. Using a high-throughput confocal-imaging approach, the aim of this work was to decipher the structural diversity of biofilms formed by 96
L. monocytogenes
strains isolated from various environments. Prior to large-scale analysis, an experimental design was created to improve
L. monocytogenes
biofilm formation in microscopic-grade microplates, with special emphasis on the growth medium composition. Microscopic analysis of biofilms formed under the selected conditions by the 96 isolates revealed only weak correlation between the genetic lineages of the isolates and the structural properties of the biofilms. However, a gradient in their geometric descriptors (biovolume, mean thickness, and roughness), ranging from flat multilayers to complex honeycomb-like structures, was shown. The dominant honeycomb-like morphotype was characterized by hollow voids hosting free-swimming cells and localized pockets containing mixtures of dead cells and extracellular DNA (eDNA).