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The aim of this study is to utilize waste thermal energy from industries into useful heat for water and air heating. In this paper, the thermal modeling and performance of three fluid heat exchangers (TFHE) have been experimentally investigated. The TFHE considered here is an enhanced version of the double‐pipe heat exchanger. A novel TFHE having fin (1 mm thin copper wire of 10 mm pitch) acts as a roughness element, which is wrapped on the helical coil's outer surface for increasing heat transfer (HT) rate and the turbulence effect for normal water, and this outer surface finned helical coil is inserted between two concentric straight tubes. The innermost tube carries atmospheric air, the finned helical coil tube carries waste hot fluid while normal water flows in the inner annulus of the outermost tube. The coiled‐side Reynolds number is varied in the range of 7000–30,000, while the curvature ratio of 0.1315, pitch‐to‐inside diameter ratio of 2.88 and wire‐to‐tube diameter e/d=0.182 $e/d=0.182$ of the helical tube is kept constant. A counterflow arrangement has been made for experimentation. Nusselt number is calculated using the traditional Wilson plot method that is compared and validated with results available in the literature. The overall HT coefficient is found to increase by increasing the volume flow rate of fluids, while effectiveness decreases or increases depending on residence time and capacity ratio. The percentage increment in the Nusselt number, maximum friction factor, overall HT coefficient between waste hot fluid to normal water, effectiveness is found to be 21.10%–23.88%, 90.91%, 3.40%–29.45%, 3.40%–25.33%, respectively, for the coil side. TFHE is thus proposed for heating water and space simultaneously. [ABSTRACT FROM AUTHOR]

This paper is an experimental and theoretical study that aimed at conserving energy by utilizing the waste heat generated from a refrigeration system by calculating the range of condensation after the compression stage for the refrigerant (R410A). A helical coil tubeshell heat exchanger was designed as a heat recovery unit to use the waste heat from an air conditioner 1TR (split type) in the outdoor unit between the compressor and the condenser to produce hot water and increase the coefficient of performance (COP) of the refrigeration cycle. Two experimental types of the helical coil heat exchanger (conventional and finned) were used in attempts to induce absorption of the rejected heat into tap water. The increase in the COP ranges from 12.5% to 40%, an increase in the water outlet temperatures difference reaches 12°C. A cost-benefit analysis in terms of the net present value and the payback period (PP) has been performed. From the analysis, it has been observed that the use of the designed heat recovery unit will save electrical consumption to produce the required hot water with a PP of about 11.7 months for the conventional heat exchanger and 17.5 months for the finned helical coil heat exchanger. [ABSTRACT FROM AUTHOR]

Activity‐regulated cytoskeleton‐associated protein (Arc) is a protein interaction hub with diverse roles in intracellular neuronal signaling, and important functions in neuronal synaptic plasticity, memory, and postnatal cortical development. Arc has homology to retroviral Gag protein and is capable of self‐assembly into virus‐like capsids implicated in the intercellular transfer of RNA. However, the molecular basis of Arc self‐association and capsid formation is largely unknown. Here, we identified a 28‐amino‐acid stretch in the mammalian Arc N‐terminal (NT) domain that is necessary and sufficient for self‐association. Within this region, we identified a 7‐residue oligomerization motif, critical for the formation of virus‐like capsids. Purified wild‐type Arc formed capsids as shown by transmission and cryo‐electron microscopy, whereas mutant Arc with disruption of the oligomerization motif formed homogenous dimers. An atomic‐resolution crystal structure of the oligomerization region peptide demonstrated an antiparallel coiled‐coil interface, strongly supporting NT‐NT domain interactions in Arc oligomerization. The NT coil–coil interaction was also validated in live neurons using fluorescence lifetime FRET imaging, and mutation of the oligomerization motif disrupted Arc‐facilitated endocytosis. Furthermore, using single‐molecule photobleaching, we show that Arc mRNA greatly enhances higher‐order oligomerization in a manner dependent on the oligomerization motif. In conclusion, a helical coil in the Arc NT domain supports self‐association above the dimer stage, mRNA‐induced oligomerization, and formation of virus‐like capsids. Database: The coordinates and structure factors for crystallographic analysis of the oligomerization region were deposited at the Protein Data Bank with the entry code 6YTU. [ABSTRACT FROM AUTHOR]

The main selection criterion for pumps in reprocessing applications is the absence of any moving parts or the moving parts not having any direct contact with the process fluid. There are different types of fluidic pumps such as vortex diode, reverse flow diode, etc. In this work, a new design of helical coil fluidic pump has been developed and demonstrated. Helical coils are widely used in process industries as heat exchangers, reactors, motionless mixers, etc. It is for the first time that the authors are proposing the use of helical coil as a fluidic pump based on its inherent property of high pressure drop as compared to a straight tube. The main objective of this work is to develop an alternate pumping system for reprocessing applications to replace the conventional air lift pump. The helical coil based fluidic diode pump was made up of SS 304 seamless pipe (pipe inner diameter is 9.5 mm) with a 36 mm diameter of helical coil and pitch of 14 mm. In this work, friction factor for the given helical coil was measured from pressure drop experiments. This information was also useful for understanding the transition of the laminar to turbulent region. In order to propose the operating region, the pumping capacity was measured for the helical coil based fluidic pump at different operating conditions. Experimental results show that the proposed hardware is able to pump up to 54 dm3/h. Recommendations have been made for proposing an optimum design. [ABSTRACT FROM AUTHOR]

Experimental investigations of heat transfer characteristics and performance enhancement of shell and helical coil water coolers using external radial fins and different shells diameters were conducted. The study aims to enhance the water coolers performance in a trial to improve coil compactness. Two helical coils; one with a plain tube and the other with external radial fins, were tested in four shells of different tube diameters. Refrigerant passing inside the helical coils was used to cool water that enclose/passes in the space between the helical coil and the shell. Tests were conducted under mixed convection heat transfer regimes. Results showed performance and compactness enhancement with the insertion of external radial fins and increasing the shell diameter to helical coil diameter ratio. For nonfinned and finned coils, Nusselt number increased with increasing Reynolds number, Grashof number, and shell diameter. Correlations were predicted to give the Nusselt number in terms of Reynolds number, Grashof number, and shell diameters for finned and nonfinned helical coils. Correlations predictions were compared with present and previous experimental results and good agreements were obtained. [ABSTRACT FROM AUTHOR]

ABSTRACT Numerical simulation was conducted to investigate the flow and heat transfer of high-pressure synthesis gas (syngas) in an annular channel consisting of membrane helical coils. Effects of radial pitch, axial pitch, and inner helical coil diameter were considered. The numerical results are in a good agreement with our previous experimental results of heat transfer in membrane helical-coil annular channels. The average heat transfer coefficient of the membrane helical coil decreases to a constant with the rise of radial pitch; meanwhile, it increases first and decreases afterwards with the increase of axial pitch. Although the local heat transfer coefficients of the inner and outer coil are irrelevant to the coil curvature, the average heat transfer coefficient of inner coil is higher than that of outer coil due to the lower finned ratio of inner coil. © 2011 Curtin University of Technology and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Heat and particle flux control is one of the most important and difficult problems in steady-state fusion devices. The Dynamic Ergodic Divertor (DED) is an advanced concept in which a rotational perturbed magnetic field is applied to make the tokamak edge magnetic structure stochastic so that it may decrease the heat and particle flux onto the local target in the conventional divertor. This rotational perturbed field is created by two sets of local helical coils (LHC) with a phase difference of 90° in the supplied ac currents. In DED experiments, it is important to study the perturbed magnetic field structure generated by these coil currents. In this paper, a new coil configuration is considered, which has an additional series of return windings so as to improve the mode quality of the rotating helical field (RHF). We obtain the mode structure of RHF using a new Fourier analysis. From this result, we confirm that the parasitic mode of RHF and the coil self-inductance are decreased by the new coil configuration. © 2002 Scripta Technica, Electr Eng Jpn, 139(1): 16–23, 2002; DOI 10.1002/eej.1142 [ABSTRACT FROM AUTHOR]

The augmentation in heat transfer can be achieved by improving either transport phenomena with geometry perturbation or thermal conductivity of the fluid itself. In the present study, the simultaneous effects of both the geometry and improved thermal conductivity have been tried on heat transfer enhancement by using two different nanofluids (Al2O3-water and TiO2-water). An innovative three-dimensional device called a coiled flow inverter (CFI) is proposed for the process intensification. The CFI is made up of helical coiled tube, which is bent periodically to 90 ° at equidistant length. In addition to a CFI, the performance characteristics of helical coil and straight tube have been investigated. The Reynolds numbers are in the range of 25-4000, while the nanoparticle volume fraction varied from 0.25-4 %. It was noted that the heat transfer in a CFI improved considerably as compared to helical coil and straight tube of same dimension. The Nusselt number in helical coil augments by 2.5 times to that of straight tube. In the CFI, the Nusselt number further enhanced by 23-35 % as compared to helical coil, with 0-4 % increase in the nanoparticle volume fractions. The new correlations are developed to predict the Nusselt number and friction factor for the flow of nanofluids in the CFI. The number of merit in the CFI to that of straight tube are 1.6-1.8 times, with 0-4 % nanoparticle volume fractions. The present study may motivate the design and development of novel compact heat exchangers as well as a new-generation microfluidic device. [ABSTRACT FROM AUTHOR]

The results of measurements using two different particle image velocimetry (PIV) systems (2D-PIV versus stereo-PIV) are compared and the obtained data with a coupled CFD simulation are also correlated. A stirred vessel with internal helical coil as additional heat exchanger is analyzed with these settings. Results for the velocity fields and turbulent kinetic energy distribution are shown and the feasibility of stereo-PIV measurements by using refractive index matching fluid is proven. This investigation provides a good accordance and consistency between the different PIV systems and the related CFD. [ABSTRACT FROM AUTHOR]

Abstract: This research proposes a transmitting coil structure for wireless charging which has the constant efficiency regardless of the position of the receiving coil. The proposed transmitting coil is designed to operate at 140 kHz, and to improve the uniformity of the magnetic field intensity using a stepped helical coil and ferrite core. The measured results of the charging system with proposed transmitting coil show that it has low difference in rectifying voltage and efficiency within the charging area. Therefore, it has advantages in terms of wide charging area without the charging shadow area. [ABSTRACT FROM AUTHOR]

An investigation on flow pattern, pressure drop, and holdup of cocurrent upward two-phase flow in a vertical helical coil tube has been carried out with Newtonian and non-Newtonian fluids. The flow patterns observed in the present study are divided into three main regimes, i.e. plug flow, slug flow, and stratified flow. Lockhart-Martinelli parameter ( X) was used to predict the friction factor and frictional pressure drop of two-phase flow. Correlations for the frictional pressure drop were developed to interpret the observed flow patterns with various operating variables. The effect of geometrical parameters on flow pattern, pressure drop, and holdup are enunciated. Based on the experimental data, a correlation was proposed to predict the flow transitions of flow patterns (i.e. plug-slug flow and slug-stratified flow) by dimensional analysis. Probabilistic neural network model has also been developed to predict the flow patterns of two-phase flow. © 2015 Curtin University of Technology and John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

An L = 2 helical heliac is a newly proposed helical-axis configuration of heliac type in which toroidal coils and a center conductor are replaced by L = 2 helical coils with a double helix. The Shafranov shift of the magnetic axis in an L = 2 helical heliac is suppressed as the helical displacement of a helical coil axis (HDCA) increases because of the increase in the rotational transforms. This suggests that the equilibrium beta limit is large for an L = 2 helical heliac with a large HDCA. An L = 2 helical heliac with a larger HDCA, however, has no magnetic well, a larger magnetic ripple, and a smaller outermost surface. No magnetic well means that the stability beta limit of an L = 2 helical heliac with a large HDCA is low because the magnetic shear of an L = 2 helical heliac is not so large. The optimum coil parameter set of an L = 2 helical heliac is presented from the standpoint of the equilibrium and stability beta limit. © 1999 Scripta Technica, Electr Eng Jpn, 130(3): 1–8, 2000 [ABSTRACT FROM AUTHOR]

The paper presents numerical investigations of a three fluid heat exchanger (TFHE), which is an improvement on the double pipe heat exchanger, where a helical tube is inserted in the annular space between two straight pipes. The helical tube side fluid, that is, hot water continuously transfers heat to the outer annulus side fluid and innermost tube side fluid. The heat transfer and pressure drop characteristics of the TFHE are assessed for different flow rates and inlet temperatures. With an increment in the volumetric flow rate of the helical tube side fluid and outer annulus side fluid, the overall heat transfer coefficient increases, and the effectiveness decreases for heat transfer from the helical tube side fluid to outer annulus side fluid in both parallel flow and counter flow configurations. It is also observed that with increment in the helical tube side fluid inlet temperature, the overall heat transfer coefficient and effectiveness increases for heat transfer from the helical tube side fluid to outer annulus side fluid in both flow configurations. The parameter, JF factor, has been proposed to evaluate the thermohydraulic behavior of the TFHE, where it is obtained that the behavior of the TFHE is better at a lower helical tube side fluid velocity and higher outer annulus side fluid velocity. [ABSTRACT FROM AUTHOR]

Abstract: Agitation is one of the widely used chemical engineering operations involving both simultaneous heat transfers and reaction. In this study, an effort has been made to simulate experimentally studied heat transfer behavior of microfluid in an agitated vessel. Simulated Nusselt numbers were compared with experimental values and found to be in good agreement with experimental values within ±10% deviation. Simulated temperature contours clearly depicted the temperature of cooling water increases gradually along the length of helical coil from the inlet to outlet. Radial mixing was found to be more in disk turbine agitator than the propeller agitator which lead to higher heat transfer rate in disk turbine agitator confirming the experimental observation. [ABSTRACT FROM AUTHOR]

Since polyurethane was introduced as an insulation material for pacing leads, it has been purported that passing two polyurethane leads through one vein would he significantly easier than passing two bipolar silicone leads. However, this case, in which two bipolar silicone leads were easily positioned via a single cephalic vein, raises the question of whether there is any clinically significant in vivo lubricity difference between the two materials. [ABSTRACT FROM AUTHOR]

Boroxines, (R-BO)3, which can be easily synthesized via a dehydration reaction of boronic acids, R-B(OH)2, selectively self-assemble in toluene into nanofibers, nanorods, nanotapes, and nanotubes, depending on the aromatic substituent (R). Spectroscopic measurements show that the nanotube consists of a J-aggregate of the boroxine. Humidification converts the morphology from the nanotube to a sheet as a result of the hydrolysis of the boroxine components and subsequent molecular-packing rearrangement from the J-aggregate to an H-aggregate. Such a transformation leads to the compulsive release of guest molecules encapsulated in the hollow cylinder of the nanotube. The hydrolysis and the molecular-packing rearrangement described above are suppressed by coordination of pyridine to the boron atom, with the resulting moiety acting as a Lewis acid of the boroxine component. The pyridine-coordinated nanotube is transformed into a helical coil by humidification. Guest release during the nanotube-to-helical-coil transformation is much slower than during the nanotube-to-sheet transformation, but faster than from a nanotube that did not undergo morphological transformation. The storage and release of guest molecules from the boroxine nanotubes can be precisely controlled by adjusting the moisture level and the concentration of Lewis bases, such as amines. [ABSTRACT FROM AUTHOR]

Abstract: Electromagnetic actuators (EMAs) serve the majority of motion control needs in fields ranging from industrial robotics to automotive systems and biomedical devices, due to their unmatched combination of speed, precision, force, and scalability. This paper describes the design and fabrication of miniature soft EMAs that operate based on the Lorentz force principle. The actuators are fabricated from silicone polymer, liquid metal (LM) alloy (eutectic gallium indium, EGaIn), and magnetic (NdFeB) powder. They are small, intrinsically deformable, and can be fabricated using simple techniques. The central elements of the actuators are fine, 3D helical coil conductors, which are used as electromagnetic inductors. The coils are formed from stretchable filaments that are filled with a LM alloy. To achieve high power densities, the filaments themselves may be fabricated from colloids of EGaIn microdroplets in a silicone polymer matrix, allowing them to dissipate heat and accommodate high currents, and thus high forces. Millimeter‐scale cylindrical actuators are demonstrated for linear high frequency motion and articulated devices for bending motion. These actuators are applied in a vibrotactile feedback display and in a miniature soft robotic gripper. [ABSTRACT FROM AUTHOR]

In this study, the effect of evaporator geometry on the loop thermosyphon's heat transfer coefficient is experimentally verified by using water as a working fluid with three filling ratios (50%, 70%, 90%), constant heat input (185 W), and condenser cooling water flow rate remaining constant at 2 Lpm. Three evaporator pipes are used (I: straight; II: helical coil evaporator with a diameter of 100‐mm coil and two turns; III: helical coil evaporator with a diameter of 50‐mm coil and four turns). From the experimental results, it can be observed that the performance of evaporator III is higher than the two other forms. A greater heat transfer coefficient value is found in case of type III evaporator and is equivalent to 2456 W/m² ·°C. The maximum thermal resistance reduction occurs in the type III evaporator (37.32%), and the highest effective thermal conductivity for the same type is 6.123e + 05 W/m·°C. The experimental results demonstrate good agreement with the empirical equations. [ABSTRACT FROM AUTHOR]

Rates of mass and heat transfer at vibrating helical coils were studied by the electrochemical technique with the object of using helical coils as heat exchanger/reactor for conducting liquid-solid diffusion controlled reactions. Variables studied were frequency and amplitude of vibration, tube diameter, and superimposed axial flow velocity. The data for vibrating coil (batch reactor) were correlated for 59 < [ABSTRACT FROM AUTHOR]

Methyl-CpG-binding protein 2 (MeCP2) is a multifunctional protein involved in chromatin organization and silencing of methylated DNA. MAR-BD, a 125-amino-acid residue domain of chicken MeCP2 (cMeCP2, originally named ARBP), is the minimal protein fragment required to recognize MAR elements and mouse satellite DNA. Here we report the solution structure of MAR-BD as determined by multidimensional heteronuclear NMR spectroscopy. The global fold of this domain is very similar to that of rat MeCP2 MBD and MBD1 MBD (the methyl-CpG-binding domains of rat MeCP2 and methyl-CpG-binding domain protein 1, respectively), exhibiting a three-stranded antiparallel β-sheet and an α-helix α1 . We show that the C-terminal portion of MAR-BD also contains an amphipathic helical coil, α2 /α3 . The hydrophilic residues of this coil form a surface opposite the DNA interface, available for interactions with other domains of MeCP2 or other proteins. Spectroscopic studies of the complex formed by MAR-BD and a 15-bp fragment of a high-affinity binding site from mouse satellite DNA indicates that the coil is also involved in protein·DNA interactions. These studies provide a basis for discussion of the consequences of six missense mutations within the helical coil found in Rett syndrome cases. [ABSTRACT FROM AUTHOR]

Objective: Anti–histidyl‐transfer RNA synthetase (Jo‐1) antibodies are associated with myositis as well as different extramuscular organ complications comprising the anti‐synthetase syndrome. This study aimed to clarify the relationship between anti–Jo‐1 epitope recognition patterns and specific clinical features of this syndrome. Methods: B cell epitope mapping was performed via enzyme‐linked immunosorbent assay in 180 patients who were anti–Jo‐1 antibody‐positive using overlapping peptides/protein fragments spanning the amino‐terminal 151 amino acids of Jo‐1 as substrate antigens. Statistical associations with clinical features were assessed through rank‐sum, correlation, and cluster analyses. Results: The level of reactivity against subfragments spanning amino acids 1–151 of Jo‐1 paralleled that of full‐length Jo‐1, confirming the immunodominance of this amino‐terminal region. The corresponding frequencies of reactivity to peptides 1 (amino acids [aa] 1–21), 3 (aa 27–47), 4 (aa 40–60), 10 (aa 118–138), and 11 (aa 131–151) were 6.1%, 42.5%, 6.8%, 6.7%, and 20.3%. While anti–full‐length Jo‐1 antibodies were significantly associated with Raynaud phenomenon, anti‐fragment A2 (aa 1–60) and A3 (aa 1–90) antibodies were associated with proximal muscle weakness, Raynaud phenomenon, arthritis, and sicca syndrome. Anti‐fragment A4 (aa 1–120) and A5 (aa 1–151) antibodies were also associated with sicca syndrome. Peptide 1 (aa 1–21) antibodies were associated with Raynaud phenomenon and dysphagia. Whereas anti‐peptide 3 (aa 27–47) antibodies were also linked to Raynaud phenomenon, anti‐peptide 9 (aa 105–125) antibodies were associated with mechanic's hands. Conclusion: Autoantibodies targeting different amino‐terminal subfragments and/or peptides of Jo‐1 were associated with specific clinical features of the anti‐synthetase syndrome, demonstrating the biomarker potential of B cell epitope profiling in this disorder. [ABSTRACT FROM AUTHOR]

A 90-year-old man with bradycardia and Stokes-Adams attacks had a unipolar VVI pacemaker implanted. Twice within a short period of time we registered a total loss of function: the first incident was caused by a "fracture" between lead and electrode, and the second was due to partial dissolving of the lead. Both times new lead electrode was implanted; the second time we replaced the pulse generator as well Pacemaker analysis showed a capacitor defect leading to a 50 microampere anodal DC leakage that caused electrolysis of the helical coil conductors. The patient had no clinical symptoms besides those due to loss of pacemaker function. The present case report and others in the literature indicate that when an electrode lead fracture is found, it is necessary to check the pacemaker for DC leakage. [ABSTRACT FROM AUTHOR]

Abstract: Agitation is one of the widely used engineering operations in all of the chemical industries, which involves both material transport and heat transfer in the system. In order to conserve energy spent in heat transfer systems, enhancements to heating and cooling in industrial processes can be achieved by dispersing small‐sized particles having high thermal conductivity in a base fluid. This article reports an experimental study on the heat transfer characteristics of graphite–water microfluid in a coiled agitated vessel equipped with propeller and six bladed disc turbine impellers. The heat transfer coefficient for the graphite–water microfluid is found to be higher than that for the base fluid (water) and increased with higher volume concentrations of graphite and higher impeller speed. Comparison of the graphite–water microfluid and water is found to demonstrate a significant enhancement in the convective heat transfer coefficient. Empirical correlations for the calculation of Nusselt numbers are performed, and the calculated Nusselt number is found to be in good agreement with experimental values within ±10% deviation. [ABSTRACT FROM AUTHOR]

Metamaterials hold significant promise for enhancing the imaging capabilities of magnetic resonance imaging (MRI) machines as an additive technology, due to their unique ability to enhance local magnetic fields. However, despite their potential, the metamaterials reported in the context of MRI applications have often been impractical. This impracticality arises from their predominantly flat configurations and their susceptibility to shifts in resonance frequencies, preventing them from realizing their optimal performance. Here, a computational method for designing wearable and tunable metamaterials via freeform auxetics is introduced. The proposed computational‐design tools yield an approach to solving the complex circle packing problems in an interactive and efficient manner, thus facilitating the development of deployable metamaterials configured in freeform shapes. With such tools, the developed metamaterials may readily conform to a patient's knee, ankle, head, or any part of the body in need of imaging, and while ensuring an optimal resonance frequency, thereby paving the way for the widespread adoption of metamaterials in clinical MRI applications. [ABSTRACT FROM AUTHOR]

Nowadays, direct absorption solar collectors are a new concept of solar collectors which have attracted special attention. The type of heat transfer fluid (HTF) has a significant influence on the efficiency of this kind of collector. Therefore, in this study, a wide range of working fluids including mono nanofluid (Al2O3 ${\text{Al}}_{2}{{\rm{O}}}_{3}$ and CuO), binary nanofluid, and especially the incorporation of a new hybrid combination of nanofluid and microencapsulated phase change material (MPCM), are used as the working fluids of a triple‐walled direct absorption evacuated tube solar collector. The computational fluid dynamics (CFD) method is used for simulating the collector and investigating the effect of different parameters including volume fraction, base fluid, mass flow rate, and type of absorber tube structure (double‐ and triple‐walled) on collector thermal performance. Results show that binary nanofluids of 0.06% Al2O3 ${\text{Al}}_{2}{{\rm{O}}}_{3}$/0.002% CuO/water and 0.06% Al2O3 ${\text{Al}}_{2}{{\rm{O}}}_{3}$/0.002% CuO/ethylene glycol (EG) have the largest working fluid temperature differentials equal to 48.31 and 66.5 K, respectively. It was inferred that, at the mass flow rate of 2.7 kg/h $\mathrm{kg}/{\rm{h}}$, the efficiency is obtained to be 60.29% employing binary/EG nanofluid, which is 8.68% and 15.31% higher than CuO/EG and Al2O3 ${\text{Al}}_{2}{{\rm{O}}}_{3}$/EG nanofluids, respectively. Inserting the hybrid CuO nanofluid/MPCM leads to an improvement of 1.14% and 1.22% in the efficiency of triple‐ and double‐walled collectors, respectively, with respect to the individual usage of the nanofluid. The thermal efficiency of the double‐walled structure is higher than triple‐walled considering all HTFs. [ABSTRACT FROM AUTHOR]

Agitated vessels are used for a wide range of applications, especially in chemical industry. This work is a pilot study on the influence of the stirrer installation height on the local as well as on the total heat flux with an immersed helical coil in an agitated vessel. A simplified geometrical model is used for observation of fundamental effects in contrast to a full mathematical model. The local heat flux, however, was observed to demonstrate the heat flux disparity along the coil. An optimum is proposed with the aim to maximize total heat flux and minimize tempering time. [ABSTRACT FROM AUTHOR]

This study presents analytical formulation used for design of helical coil for induction heating of solid and hollow cylindrical non‐magnetic workpiece (graphite crucible). This formulation is applied for estimation of the active power in graphite crucibles and reactive power drawn by the induction coil in presence of different wall thickness (30, 20, 10 and 5 mm) of graphite crucibles at different frequency (1–50 kHz). Magnetic field produced by induction coil is estimated by using empirical factors suggested by kNagaoka et al. Induction heating processes, i.e. electromagnetism and heat transfer physics are mathematically modelled by Maxwell and Fourier equations, respectively. Finite‐element method is used to solve the electromagnetic field in frequency domain and heat transfer in transient domain. Numerical analysis is carried out by using two‐dimensional axisymmetric geometry. Analytical results and numerical results are compared and are found to be in good agreement with each other. Experimentally obtained coil voltage and graphite crucible temperature were compared with numerical results and the authors found that they also match very well confirming the validity of their assumptions in analytical/numerical approach. [ABSTRACT FROM AUTHOR]

Background: Snail mucin is becoming increasingly popular for its wide range of ingredients and potential benefits. Snail extract's widespread appearance in cosmetic formulations encourages an investigation into the medical and cosmetic benefits. Aims: This study aims to explore current literature on the variety of snail mucin applications. Specifically, we present a review of the uses, global market estimates and projects, and limitations to snail mucin. Methods: A literature search was conducted on PubMed reviewing snail mucin and their application in medical and dermatologic fields examining their uses. Economic reports were also investigated for Global Market estimates. Results: The therapeutic use of snail mucin in medical fields has been studied as antimicrobial agents, drug delivery vehicles, antitumor agents, wound healing agents, and biomaterial coatings among others. Additionally, the use in cosmetic fields includes antiaging, hydrating, anti‐acne, scarring, and hyperpigmentation treatments. It is important to highlight that most studies conducted were preclinical or small clinical studies, stressing the need for additional large‐scale clinical trials to support these claims. Investigations into the global market found estimates ranging from $457 million to $1.2 billion with upward projections in the upcoming decade. Limitations include ethical habitats for collection, allergy investigation, and missing clinical studies. Conclusions: The findings presented here emphasize the expanding uses of snail mucin and its ingredients alongside a growing market cosmetic industry should consider. We also emphasize the need for appropriate clinical trials into the stated benefits of snail mucin to ensure consumer safety and ethical extraction of mucin. [ABSTRACT FROM AUTHOR]

The immediate and well‐documented benefits of carbohydrate restriction include improved glycemic control in individuals with diabetes mellitus. Starch, a significant source of carbohydrates, is categorized as rapidly digestible, slowly digestible, or resistant starch (RS). RS, which is a non‐viscous fermentable fiber, has shown promise in animal studies for antidiabetic effects by improving glucose metabolism. Although the exact mechanism by which RS affects glucose metabolism remains unclear, it is expected to positively impact glucose tolerance and insulin sensitivity. The fermentation of RS by colonic microbiota in the large bowel produces short‐chain fatty acids, which exert multiple metabolic effects on glucose regulation and homeostasis. Moreover, RS may influence glucose metabolism via bile acid modulation, independent of its fermentation. Diets rich in RS could aid in blood glucose homeostasis. However, it is uncertain whether they can alter the metabolic pathology associated with glucose regulation. In essence, RS has the potential to lower postprandial glucose levels similarly to a low‐glycemic index diet. Yet, its efficacy as a medical nutrition therapy for type 2 diabetes needs further investigation. To confirm the role of RS in glycemic control and to possibly recommend it as an additional dietary approach for people with type 2 diabetes mellitus, a well‐designed, large‐scale intervention is required. [ABSTRACT FROM AUTHOR]

Researchers and engineers are actively working on enhancing the efficiency of heat exchangers in engineering applications by developing novel designs, exploring new materials, and utilizing nanofluids. Three kinds of nanofluids with varying concentrations are investigated in this paper. The objective is to assess the performance of N‐shaped double‐pipe heat exchanger used in thermoelectric power plants. The performance has been evaluated using COMSOL Multiphysics software. The findings show that higher nanofluid concentrations resulted in elevated heat transfer coefficients and improved efficiency of N‐shape double pipe heat exchanger. The analysis revealed that a mere 1% rise in the volume fraction of nanofluids enhanced the efficiency of the heat exchanger on average 23% when compared to the base fluid (water). In comparison to the N‐shape double pipe (Inconel 625) heat exchangers, the N‐shape double pipe (copper) heat exchangers appear to be more efficient. The introduction of nanoparticles has a notable impact on the heat transfer coefficients. Specifically, within an N‐shaped double pipe (copper) heat exchanger, the inclusion of a 1% volume fraction results in a 2.09% enhancement in the heat transfer coefficient for Al2O3/water, a 1.3% improvement for Fe3O4/water, and a 1.15% increase for TiO2/water. It also exposed that adding 1% Al2O3/water led to a significant 0.623% increase in effectiveness, while TiO2/water showed a 0.259% rise, and Fe3O4/water exhibited a 0.375% improvement. Moreover, increasing the Reynolds number enhances the Nusselt number for Al2O3/water and Fe3O4/water nanofluids by 55.22%, and for TiO2/water by 54.60% at a 6% volume concentration, leading to additional increases in exchanger efficiency. Therefore, the augmentation in nanofluid concentration leads to a reduction in the temperature pinch points both at the intake and outflow. This observation suggests that nanofluids exhibit a superior ability compared to conventional fluids when it comes to effectively lowering temperatures. [ABSTRACT FROM AUTHOR]

Heat exchangers are extensively used in various industries. In this study, the impact of geometric and flow parameters on the performance of a shell and double helical coil heat exchanger is studied numerically. The investigated geometric parameters include external coil pitch, internal coil pitch, internal coil diameter, and coil diameter. The influences of considered geometrical parameters are analyzed on the output temperature of the hot and cold fluid, convective heat transfer coefficient, pressure drop, and average Nusselt number. Water is considered as working fluid in both shell and tube. As an innovation, double helical coils are used instead of one in the heat exchanger. To compare the obtained results accurately, in each section, the heat transfer area (coil outer surface) is kept constant in all models. The results show that the geometrical parameters of double helical coils significantly affect the heat transfer rate. [ABSTRACT FROM AUTHOR]

Results of heat transfer coefficient measurements in an agitated vessel heated or cooled by the liquid media flowing in a helical pipe coil are presented in this paper. The multistage impeller made of two pitched six-blade impellers and adjustable clearance was used in a vessel with conical bottom. The transient method based on measuring the temperature dependency on time and solving the unsteady enthalpy balance was used to determine the heat transfer coefficients between the agitated liquid and the helical pipe coil. The results are summarized by the Nusselt number correlations, which describe the dependency on the impeller Reynolds number. The second part of this paper introduces a theoretical analysis of the flow in the liquid batch near the helical pipe coil. Based on the known pumping capacity of the multistage impeller, the characteristic velocity near the helical pipe coil can be evaluated. This characteristic velocity can be then used to determine the Nusselt number describing the heat transfer in a flow around a cylinder with the same cross-section profile as the helical pipe coil. A clear correlation between this Nusselt number and the integral Nusselt number is presented in this paper and introduces an alternative approach for prediction of heat transfer characteristics on the basis of hydrodynamic parameters describing an agitated system. [ABSTRACT FROM AUTHOR]

The transport of impurities supplied by a multi‐species impurity powder dropper (IPD) in the large helical device (LHD) is investigated using a three‐dimensional peripheral plasma fluid code (EMC3‐EIRENE) coupled with a dust transport simulation code (DUSTT). The trajectories of impurity powder particles (Boron, Carbon, Iron, and Tungsten) dropped from the IPD and the impurity transport in the peripheral plasma are studied in a full‐torus geometry. The simulation reveals an appropriate size of the impurity powder particles and an optimum operational range of the dust drop rates for investigating the impurity transport without inducing radiation collapse. The simulation also predicts a favourable plasma discharge condition for wall conditioning (boronization) using the IPD in order to deposit boron to high plasma flux and neutral particle density areas in the divertor region in the inboard side of the torus. [ABSTRACT FROM AUTHOR]

Definition of the unfolded state of proteins is essential for understanding their stability and folding on biological timescales. Here, we find that under near physiological conditions the configurational ensemble of the unfolded state of the simplest protein structure, polyalanine α-helix, cannot be described by the commonly used Flory random coil model, in which configurational probabilities are derived from conformational preferences of individual residues. We utilize novel effectively ergodic sampling algorithms in the presence of explicit aqueous solvation, and observe water-mediated formation of polyproline II helical (PII) structure in the natively unfolded state of polyalanine, and its facilitation of α-helix formation in longer peptides. The segmented PII helical coil preorganizes the unfolded state ensemble for folding pathway entry by reducing the conformational space available to the diffusive search. Thus, as much as half of the folding search in polyalanine is accomplished by preorganization of the unfolded state. Proteins 2004. © 2004 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Abstract: The assembly characteristics of the neuronal intermediate filament protein plasticin were studied in SW13 cells in the presence and absence of a cytoplasmic filament network. Full-length plasticin cannot polymerize into homopolymers in filament-less SW13c1.2Vim- cells but efficiently coassembles with vimentin in SW13c1.1Vim- cells. By cotransfecting plasticin and vimentin in SW13c1.1Vim- cells, we show that plasticin assembly requires vimentin in noncatalytic amounts. Differing effects on assembly were seen with point mutations of plasticin monomers that were analogous to the keratin mutations that cause epidermolysis bullosa simplex (EBS). In particular, plasticin monomers with point mutations analogous to those in EBS do not uniformly inhibit neurofilament (NF) network formation. A point mutation in the helix termination sequence resulted in complete filament aggregation when coexpressed with vimentin but showed limited coassembly with low- and medium-molecular-weight NF proteins (NF-L and NF-M, respectively). In transfected SW13c1.1Vim+ cells, a point mutation in the first heptad of the α-helical coil region formed equal amounts of filaments, aggregates, and a mixture of filaments and aggregates. Furthermore, coexpression of this point mutation with NF-L and NF-M was associated with a shift toward increased numbers of aggregates. These results suggest that there are important structural differences in assembly properties between homologous fish and mammalian intermediate filament proteins. These structural differences may contribute to the distinctive growth characteristics of the teleost visual pathway. [ABSTRACT FROM AUTHOR]

Double‐strand break (DSB), a significant DNA damage brought on by ionizing radiation, acts as an initiating signal in tumor radiotherapy, causing cancer cells death. The two primary pathways for DNA DSB repair in mammalian cells are nonhomologous end joining (NHEJ) and homologous recombination (HR), which cooperate and compete with one another to achieve effective repair. The DSB repair mechanism depends on numerous regulatory variables. DSB recognition and the recruitment of DNA repair components, for instance, depend on the MRE11–RAD50–NBS1 (MRN) complex and the Ku70/80 heterodimer/DNA–PKcs (DNA–PK) complex, whose control is crucial in determining the DSB repair pathway choice and efficiency of HR and NHEJ. In‐depth elucidation on the DSB repair pathway's molecular mechanisms has greatly facilitated for creation of repair proteins or pathways‐specific inhibitors to advance precise cancer therapy and boost the effectiveness of cancer radiotherapy. The architectures, roles, molecular processes, and inhibitors of significant target proteins in the DSB repair pathways are reviewed in this article. The strategy and application in cancer therapy are also discussed based on the advancement of inhibitors targeted DSB damage response and repair proteins. [ABSTRACT FROM AUTHOR]

Recent developments in the design and synthesis of more and more sophisticated organic building blocks with controlled structures and physical properties, combined with the emergence of novel assembly modes and nanofabrication methods, make it possible to tailor unprecedented structurally complex porous systems with precise multiscale control over their architectures and functions. By tuning their porosity from the nanoscale to microscale, a wide range of functional materials can be assembled, including open frameworks and micro/nanoscaffold architectures. During the last two decades, significant progress is made on the generation and optimization of advanced porous systems, resulting in high‐performance multifunctional scaffold materials and novel device configurations. In this perspective, a critical analysis is provided of the most effective methods for imparting controlled physical and chemical properties to multifunctional porous skeletons. The future research directions that underscore the role of skeleton structures with varying physical dimensions, from molecular‐level open frameworks (<10 nm) to supramolecular scaffolds (10–100 nm) and micro/nano scaffolds (>100 nm), are discussed. The limitations, challenges, and opportunities for potential applications of these multifunctional and multidimensional material systems are also evaluated in particular by addressing the greatest challenges that the society has to face. [ABSTRACT FROM AUTHOR]

Tendrils of climbing plants coil along their length, thus forming a striking helical spring and generating tensional forces. It is found that, for tendrils of the passion flower Passiflora caerulea, the generated force lies in the range of 6–140 mN, which is sufficient to lash the plant tightly to its substrate. Further, it is revealed that the generated force strongly correlates with the water status of the plant. Based on a combination of in situ force measurements with anatomical investigations and dehydration‐rehydration experiments on both entire tendril segments and isolated lignified tissues, a two‐phasic mechanism for spring formation is proposed. First, during the free coiling phase, the center of the tendril begins to lignify unilaterally. At this stage, both the generated tension and the stability of the form of the spring still depend on turgor pressure. The unilateral contraction of a bilayer as being the possible driving force for the tendril coiling motion is discussed. Second, in a stabilization phase, the entire center of the coiled tendril lignifies, stiffening the spring and securing its function irrespective of its hydration status. [ABSTRACT FROM AUTHOR]

The cell membrane of Halobacterium salinarum contains a retinal‐binding photoreceptor, sensory rhodopsin II (HsSRII), coupled with its cognate transducer (HsHtrII), allowing repellent phototaxis behavior for shorter wavelength light. Previous studies on SRII from Natronomonas pharaonis (NpSRII) pointed out the importance of the hydrogen bonding interaction between Thr204NpSRII and Tyr174NpSRII in signal transfer from SRII to HtrII. Here, we investigated the effect on phototactic function by replacing residues in HsSRII corresponding to Thr204NpSRII and Tyr174NpSRII. Whereas replacement of either residue altered the photocycle kinetics, introduction of any mutations at Ser201HsSRII and Tyr171HsSRII did not eliminate negative phototaxis function. These observations imply the possibility of the presence of an unidentified molecular mechanism for photophobic signal transduction differing from NpSRII–NpHtrII. [ABSTRACT FROM AUTHOR]

Thermal energy storage (TES) system is the most eminent storage method that aids in the power generation. Latent heat storage (LHS) is on the rapid mark‐up that fosters the TES with the utilization of the phase transition of a material to store the heat. Typically the phase change materials (PCM) are used in the LHS system to store the energy. During the material's phase transition, thermal energy is stored and released. Nevertheless, the low thermal conductivity of the PCM in the LHS is susceptible to deteriorate the charging and discharging of the thermal energy. Hence there is a necessity to enhance the thermal performance of the LHS system, on which various studies have been done. Therefore this paper aims in providing a review on the enhancements of the LHS system with improved heat transfer rate and heat transfer enhancement techniques in the PCM for better efficiency. A comprehensive review on the LHS system component is provided to make an emphasis on the heat transfer enhancement rate and storage time. Various characterizations and categories of the PCM are provided to intensify the outcomes of the review as PCMs are most viable materials for storing thermal energy. In addition the recent researches on the integration of PCM with other materials are also discussed that help in the improvements of the thermal conductivity of the PCM. The selection parameters of the PCM materials are also discussed in brief to avoid the poor performance of the PCMs. The heat transfer analysis methods are analyzed to improve the efficiency and reduce the heat loss. Finally, advancements in the future trends for the enhancement of heat transfer is provided. [ABSTRACT FROM AUTHOR]

Electrospinning has received a lot of attention in recent years because it can create nonwoven nanofiber webs with high surface area and porosity. However, the typical needle and syringe‐based electrospinning systems feature poor productivity that has limited their usefulness in the industrial field. Here, current developments in the creation of nanofibers employing nonconventional electrospinning methods, such as needleless electrospinning and syringeless electrospinning, are examined. These alternate electrospinning techniques, which are dependent on numerous polymer droplets of varied shapes, have the potential to match the productivity required for industry‐scale manufacturing of nanofibers. Additionally, they make it possible to produce nanofibers that are difficult to spin using traditional techniques, like electrospinning of colloidal suspensions. [ABSTRACT FROM AUTHOR]

Considering a prospect where a driverless electric vehicle (EV) requires an automatic charging system that does not need a person to do anything. In this case, there is a need for a fully automated, fast, safe, cost‐effective, and reliable charging infrastructure that can be used for EVs and other EVs. This infrastructure must also be profitable and allow for quick adoption in electric transportation systems. Wireless charging methods may allow you to understand these characteristics. Wireless power transfer (WPT) is a future technology that offers flexibility, convenience, safety, and the capacity to be automated. Due to its high efficiency and ease of maintenance, resonant inductive wireless charging should get more attention in WPT techniques than other WPT methods. This literature provides an overview of the status of Resonant Inductive Wireless Power Transfer Charging technology, as well as a look at the current and prospects of the wireless EV industry. First, the article provides a brief history of wireless charging technologies, outlining the benefits and drawbacks. Then, the research assists in a comparative analysis of various types of WPT methodologies, control strategies, and compensation networks that have been done so far. The static and dynamic charging procedures, as well as their features, are shown. To increase charging power, a novel approach to the usage of superconducting materials in coil designs is examined, and their potential influence on wireless charging is highlighted. The detailed role and importance of power electronics, as well as the many types of converters utilized in diverse applications, are highlighted. The batteries and their management systems, as well as numerous WPT difficulties, are also discussed. Different trades are investigated, including cyber security economic consequences, health and safety, foreign object identification, and the effect and influence on the distribution grid. This article also highlights the opportunities and challenges associated with wireless charging systems. We anticipate that our effort will contribute to the advancement of WPT system research and development. [ABSTRACT FROM AUTHOR]

The mass transfer behavior of a rotating packed bed of Raschig rings was examined to increase the rate of liquid‐solid diffusion‐controlled reactions common in the production of fine chemicals, pharmaceuticals, and wastewater treatment. The aim was to measure the enhancing effect of the centrifugal force and the high area per unit volume of the bed, using diffusion‐controlled copper dissolution in acidified dichromate as the experimental approach and the bed rotation speed, the Raschig ring diameter, and the bed height as variables. A dimensionless mass transfer equation suited for scaling up and reactor design was used to correlate the data. Measurement of the specific mechanical power consumption ε of the rotating bed under different conditions revealed that the energy utilization efficiency increases with decreasing bed rotation speed. [ABSTRACT FROM AUTHOR]

Higher magnetic field is of great advantage to superconducting magnetic energy storage because it promises a compact device. However, it does not affect the serious problem of huge electromagnetic forces caused by high magnetic fields and large coil current. Electromagnetic stresses, reaching as much as several hundred bars, thus become a major factor in determining whether a large-size strong magnetic field system can be established. In order to solve this problem, we have proposed the force-balanced coil (FBC) concept that reduces the huge centering electromagnetic forces by balancing them with the hoop forces caused by the toroidal current. Then we designed and fabricated a small-size superconducting FBC system to demonstrate the FBC concept. It was successfully excited up to near rated current. It is shown that the FBC system has the potential for simplifying the supporting structures and making the facility compact. © 1999 Scripta Technica, Electr Eng Jpn, 128(3): 82–91, 1999 [ABSTRACT FROM AUTHOR]

Recent long pulse discharges in the large helical device (LHD) have been interrupted by radiation collapse induced by the emission of dust from the surface of the vacuum vessel and the divertor region. The dust shielding effect by intrinsic ergodic magnetic field line structures (ergodic layer) formed around the main plasma confinement region is investigated using a three‐dimensional peripheral plasma fluid code (EMC3‐EIRENE) coupled with a dust transport simulation code (DUSTT). Simulations performed in three different magnetic configurations with narrow, medium, and wide ergodic layers show that the wide ergodic layer is not always effective in shielding the main plasma from the dust emission. Optimum operational regimes for controlling the influence of the dust emission on the sustainment of plasma discharges are found by investigating the impurity ion content in the peripheral plasma for various plasma heating powers and plasma densities in the three magnetic configurations. [ABSTRACT FROM AUTHOR]