Small Fin Research Articles

Electrical characteristic fluctuation of 16-nm-gate trapezoidal bulk FinFET devices with fixed top-fin width induced by random discrete dopants.

In this work, we use an experimentally calibrated 3D quantum mechanically corrected device simulation to study the random dopant fluctuation (RDF) on DC characteristics of 16-nm-gate trapezoidal bulk fin-type field effect transistor (FinFET) devices. The fixed top-fin width, which is consistent with the realistic process by lithography, of trapezoidal bulk FinFET devices is considered in this study. For RDF on trapezoidal bulk FinFETs under the fixed top-fin width, we explore the impact of geometry and RDF on the on-/off-state current and the threshold voltage (Vth) fluctuation with respect to different channel fin angles. For the same channel doping concentration, compared with an ideal FinFET (i.e., device with a right angle of channel fin), the off-state current is large in trapezoidal bulk FinFETs with a small fin angle. Furthermore, the short-channel effect and Vth variation degrade as the fin angle is getting smaller. The magnitude of the normalized σVth increases 7% when the fin angle decreases from 90° to 70°.

Fin whale sound reception mechanisms: skull vibration enables low-frequency hearing.

Hearing mechanisms in baleen whales (Mysticeti) are essentially unknown but their vocalization frequencies overlap with anthropogenic sound sources. Synthetic audiograms were generated for a fin whale by applying finite element modeling tools to X-ray computed tomography (CT) scans. We CT scanned the head of a small fin whale (Balaenoptera physalus) in a scanner designed for solid-fuel rocket motors. Our computer (finite element) modeling toolkit allowed us to visualize what occurs when sounds interact with the anatomic geometry of the whale’s head. Simulations reveal two mechanisms that excite both bony ear complexes, (1) the skull-vibration enabled bone conduction mechanism and (2) a pressure mechanism transmitted through soft tissues. Bone conduction is the predominant mechanism. The mass density of the bony ear complexes and their firmly embedded attachments to the skull are universal across the Mysticeti, suggesting that sound reception mechanisms are similar in all baleen whales. Interactions between incident sound waves and the skull cause deformations that induce motion in each bony ear complex, resulting in best hearing sensitivity for low-frequency sounds. This predominant low-frequency sensitivity has significant implications for assessing mysticete exposure levels to anthropogenic sounds. The din of man-made ocean noise has increased steadily over the past half century. Our results provide valuable data for U.S. regulatory agencies and concerned large-scale industrial users of the ocean environment. This study transforms our understanding of baleen whale hearing and provides a means to predict auditory sensitivity across a broad spectrum of sound frequencies.

Swaying Wire-driven Robot Fish Design and Prototyping

In this paper, a newly designed robot fish adopting bio-inspired wire-driven mechanism is presented. It can twist its caudal fin to give sway motion, just like most of the fish do when cursing. First, sway motion analysis and computer simulation are conducted. Next, a prototype is built and experiments are carried out to validate the simulation results. It is noted that the robot fish may roll side to side during swimming. To optimize the design, we study the fish with small pectoral fin and mimic its bone structure. The new design adopts a gradual decreasing eyelet spacing along the spine. This helps the swaying concentrated at the rear part of caudal fin. Based on the computer simulation, the new design results in an improved performance.

波浪中 Resonance-Free SWATH 運動の水中翼による非線形制御

A Resonance-Free SWATH (RFS), which has negative restoring forces, is introduced to minimize the motion responses in waves because the strict time-punctuality and the high value of the cargo require the superior seaworthiness such as no speed reduction and no slamming. Accordingly, the attitude of RFS should be adjusted by small underwater control fins. The latent ability of RFS for seaworthiness is not completely made use in the case of PD control because P gain in PD control acts as the large restoring force. In this study, a nonlinear sliding mode control has been applied to make up for deficiencies in PD control. The simulation using the time domain simulator for the sliding mode control and the experiments using the model have been carried out. As a result, the effectiveness of the sliding mode control has been confirmed. The pitch motion response of RFS under the sliding mode control is decreased by half compared with PD control.

Scaling junctionless multigate field-effect transistors by step-doping

Conventional junctionless (JL) multigate field-effect transistors (MuGFETs) use extremely scaled and highly doped fins as channels. Such small fins introduce large parasitic resistance as well as performance fluctuation due to fin width variations. The high channel doping significantly reduces bulk carrier mobility, which reduces on-state current and escalates short channel effect related leakage. In this letter, we present a step-doping scheme for the scaling of JL MuGFETs. By employing a two-step-doping profile, with the high doping side near the gate, higher threshold voltage and better off-state performance can be achieved, along with higher on-state current. This opens a route for threshold voltage design and addresses the design optimization for both on-state current and off-state leakage for JL MuGFETs.

Plasma Doping of InGaAs at Elevated Substrate Temperature for Reduced Sheet Resistance and Defect Formation

Plasma doping (PLAD), a high-throughput ion implantation technique capable of achieving ultrashallow junctions and conformal doping of 3-D structures such as fin field-effect transistors, is investigated as an alternative to conventional beam-line ion implantation for InGaAs at advanced technology nodes. The PLAD at an elevated substrate temperature (ET-PLAD) is studied and reported for InGaAs for the first time. The ET-PLAD can give lower sheet resistance than room-temperature PLAD due to enhanced dopant incorporation. More crucially, an ET can help to prevent amorphization. After dopant activation anneal, residual corner defects are observed in small fins that are amorphized during plasma ion implantation, whereas fins that remain crystalline during plasma ion implantation are free of corner defects.

Experimental investigation of natural dehumidification over an annular finned-tube

In this study, heat and mass transfer during natural condensation of humid air over a horizontal annular finned-tube is investigated experimentally. The finned-tube is made by extruded process and fins are circular with rectangular cross-section. Outer diameter of central tube, fin diameter, fin thickness and fin density are 25.4mm, 0.4mm, 56.0mm and 433 FPM (fins per meter), respectively. The test case is placed in a specially constructed insulated test room to control test conditions and simulate pure natural dehumidification. Ambient air temperature and relative humidity are controlled by heating, cooling and humidifying equipment. Ethylene glycol–water solution is used as refrigerant to control and keep fin base temperature constant. Experiments are performed for ambient air temperature of 25°C, 30°C and 35°C, relative humidity of 40%, 50%, 60% and 70% and fin base temperature of 4°C, 6°C and 8°C. Observations indicate that the water drops form mainly on tip of the fins and for the conducted tests, no condensation is observed between the fins which is mainly due to small fin spacing (2.0mm) and lack of convective heat and mass transfer between the fins. The test results also show that condensation and heat transfer rate depend mainly on the temperature and relative humidity of the surrounding air and fin base temperature. The increase in ambient air temperature and relative humidity and the decrease in fin base temperature lead to increase in heat and mass transfer rate. Furthermore, based on the results, new correlations are developed for heat and mass transfer during natural dehumidification over compact annular finned-tubes.

Simulation of an Aluminum Foam Heat Exchanger Using the Volume Averaging Technique

Open cell metal foams show a high potential for heat transfer applications. In this paper the thermal and hydraulic performance of a metal foam heat exchanger with two tube rows in a staggered layout is studied. Two-dimensional simulations are performed using a bulk model based on the volume averaging technique. A louvered fin heat exchanger with the same tube layout and overall volume is considered as reference case. Velocities range from 1.2 m/s to 3.2 m/s. An experimental validation illustrates the quality of the simulation results. For the same fan power, the 10 ppi and 20 ppi foams show a smaller heat transfer than the louvered fin heat exchanger. This is mainly due to the larger airside heat transfer surface area of the louvered fin heat exchanger (because of the small fin pitch) compared to the foams. 30 and 35 ppi foams, having a specific surface area above 1000 m2/m3, show a better thermal hydraulic performance than the louvered fin design.

Genetic Diversity of Brown Trout Populations Using Mitochondrial Markers In Relatively Similar Geographical and Ecological Conditions – a Carpathian Case Study

ABSTRACT Among the species of salmonids that exist in Romania, the most common is the brown trout (Salmo trutta, morpha fario, Linnaeus, 1758), with a high commercial potential, being used for aquaculture or fishing. Unfortunately, its natural habitat is disrupted by human activities and in order to avoid local extinction of Salmo trutta fario repopulation strategies are being applied. The repopulation activities must be carefully designed and conducted taking into consideration that there is a high risk of hybridization. Our study aims to analyze the genetic diversity of three Romanian brown trout populations found in rivers in the Făgăraş Mountains using mitochondrial markers. Standard DNA extraction protocol with phenol-chloroform was applied to the biological material represented by small fin fragments sampled from 80 individuals of brown trout, followed by PCR amplification of D-loop control region and Sanger sequencing. Alignment and editing of all the sequences obtained were carried out with Bioedit, the phylogenetic tree construction was performed by Neighbour Joining method implemented in MEGA v5, and intra- and interpopulational diversity was evaluated with DNAsp v5 and MEGA v5. For the three brown trout populations, 13 haplotypes were identified for N1, 11 for N2 and 10 for N4, with a haplotype diversity greater than 0.8. The phylogenetic tree topology showed that individuals chosen for this study were placed in the Danubian clade as the other Danubian sequences selected from GenBank. The study proved that the three Salmo trutta fario populations analyzed were genetically distinct and that in Romania there are still are pure Danubian brown trout populations.

A Method for High-Throughput PCR-Based Genotyping of Larval Zebrafish Tail Biopsies

Here we describe a method for high-throughput genotyping of live larval zebrafish as early as 72 h post-fertilization (hpf). Importantly, this technique allows rapid and cost-effective PCR-based genotyping from very small fin biopsies, which regenerate as the embryo develops, thereby allowing researchers to select embryos with desired genotypes to be raised to adulthood.

Expression and gene knockdown of zebrafish Ca2+/calmodulin-dependent protein kinase Iδ-LL

Ca2+/calmodulin-dependent protein kinase Iδ (CaMKIδ) is expressed ubiquitously, but little is known about its physiological functions. Recently, we cloned and characterized two splice variants of zebrafish (Danio rerio) CaMKIδ (CaMKIδ-S/L). In the present study we cloned a new CaMKIδ isoform, CaMKIδ-LL, encoded by a different gene from CaMKIδ-S/L. While the catalytic domain of CaMKIδ-LL showed 86% identity that of CaMKIδ-S/L, it had a unique C-terminal sequence. To clarify the functional role of CaMKIδ-LL, we investigated the biological significance of this new isoform during zebrafish embryogenesis. Although CaMKIδ-LL exhibited essentially the same catalytic properties and substrate specificities as the other CaMKIδ isoforms, it showed different temporal and spatial expression. During zebrafish embryogenesis, RT-PCR analysis detected CaMKIδ-LL expression after 48h post-fertilization. Western blotting in adult zebrafish demonstrated that CaMKIδ-LL is expressed in the brain, the eye, and, abundantly, in fins. Knockdown of CaMKIδ-LL expression using morpholino-based antisense oligonucleotides resulted in an increase in abnormal embryos with small fins and underdeveloped cartilage. These phenotypes were rescued by co-injection with recombinant CaMKIδ-LL. These results clearly indicated that CaMKIδ-LL plays an important role in the generation of cartilage and fins during zebrafish embryogenesis.

HEAT TRANSFER ENHANCEMENT OF SMALL SCALE HEAT SINKS USING VIBRATING PIN FIN

Heat sinks are widely adopted in electronics coolin g together with different technologies to enhance t he cooling process. For the small electronics applicat ion, the small scale pin fins heat sinks are extens ively used to dissipate heat in electronics devices. Due to the limit of space in the small devices, it is i mpossible to increase heat transfer area. In order to improve the heat transfer performance, the applying the fo rced vibration is one of challenging method. This study applies the vibration frequency between 50 to 1,000 Hz to pin fins heat sinks. The results of numerical si mulation clearly show satisfied heat transfer augme ntation. However, the Pressure drop significantly increases with frequency. This phenomenon affects the heat tr ansfer enhancement performance that it increases with freq uency until certain value then it drops rapidly. Th e results of this study can help designing heat sinks for ele ctronics cooling by employing the concept of vibrat ion.

Thin-Wing Vibration Control Using Flexible Fins

This paper describes thin-wing vibration control using an array of small flexible rectangular polymer fins attached near the leading edge on the upper wing surface to manipulate unsteady flow structures. Dynamic aeroelastic deformation of a rectangular flat-plate wing and motions of the fins relative to the wing are measured by using a high-speed videogrammetric system in a low-speed wind tunnel. The major vibration modes of the baseline wing and the wing with the fins are extracted. It is found that wing vibration particularly near the dominant first torsion mode is considerably suppressed by the flexible fins interacting with highly unsteady separated flows in the ranges of the freestream velocities and angles of attack. Global velocity measurements indicate that the fins significantly reduce the unsteadiness of the separated flow on the wing. The physical mechanisms behind the vibration suppression with the flexible fins are explored based on the analysis of the measured data.

Rare batfish species, Halicmetus ruber Alcock, 1891 (Lophiiformes: Ogcocephalidae), from the Indian Exclusive Economic Zone

The first authentic record of deep-sea fishes was made with the help of those collected by R. I. M. S. Investigator in the book, ‘Indian Deep Sea Fishes in the Indian Museum’. The Fishery Survey of India, concentrating principally on the continental shelf region, carried out research on deep-sea fishes within the Indian Exclusive Economic Zone (EEZ). Data on deep-sea fish fauna are scarce, and the only available information is from the fishing cruises of FORV Sagar Sampada as part of its deep-sea finfishes stock assessment programme. Earlier studies on the ogcocephalid genus Halicmetus showed that it comprised two nominal species: H. ruber Alcock, 1891 collected from the Andaman Sea and H. reticulatus Smith and Radcliffe, 1912 from the Philippines (Ho et al., 2008). However, later studies revealed that the genus Halicmetus comprises four species, of which H. reticulatus is the only member with dorsal fin rays, whereas H. nigra sp. nov., H. ruber and H. cf. ruber lack these dorsal fin rays. Halicmetus ruber Alcock, 1891 is a small benthic fish (<10 cm total length) characterised by the absence of a dorsal fin (unique among batfishes) and no colour pattern on its disk. Halicmetus reticulatus is characterised by having two or three dorsal fin rays and a reticular disk colour pattern. However, Brauer (1906) recorded seven specimens with a small dorsal fin, purportedly H. ruber from the Andaman Sea. Furthermore, Smith and Radcliffe (1912) mentioned H. ruber specimens lacking a dorsal fin ray that were collected by the RV Albatross from the western Pacific. Weber (1913) described a subspecies, H. ruber marmorata, based on five specimens (ZMA 101.893) collected in Indonesia, and synonymised to H. ruber by Bradbury (1967). On the basis of all ogcocephalid genera morphological characteristics, Bradbury (1967) concluded that the Halicmetus head is distinguishable from others in that it: is markedly depressed, with the face flattened (truncated) and distinctly upturned; shows the presence of bucklers and small tubercles; has two gills, with gill filaments only on the 2nd and 3rd gill arches; the pectoral pedicles are not well attached to the body wall; has an interrupted lateral line and with the illicial bone split into two long processes. Halicmetus specimens are uncommon. Hence, an attempt has been made here to redefine this deep-sea fish by comparing its morphometrics and meristics with those of H. cf. ruber and H. reticulatus from the Pacific Ocean. Materials and methods

Opa1 Is Required for Proper Mitochondrial Metabolism in Early Development

Opa1 catalyzes fusion of inner mitochondrial membranes and formation of the cristae. OPA1 mutations in humans lead to autosomal dominant optic atrophy. OPA1 knockout mice lose viability around embryonic day 9 from unknown reasons, indicating that OPA1 is essential for embryonic development. Zebrafish are an attractive model for studying vertebrate development and have been used for many years to describe developmental events that are difficult or impractical to view in mammalian models. In this study, Opa1 was successfully depleted in zebrafish embryos using antisense morpholinos, which resulted in disrupted mitochondrial morphology. Phenotypically, these embryos exhibited abnormal blood circulation and heart defects, as well as small eyes and small pectoral fin buds. Additionally, startle response was reduced and locomotor activity was impaired. Furthermore, Opa1 depletion caused bioenergetic defects, without impairing mitochondrial efficiency. In response to mitochondrial dysfunction, a transient upregulation of the master regulator of mitochondrial biogenesis, pgc1a, was observed. These results not only reveal a new Opa1-associated phenotype in a vertebrate model system, but also further elucidates the absolute requirement of Opa1 for successful vertebrate development.

Strain and Conduction-Band Offset in Narrow n-type FinFETs

In this paper, we compare measurements of the conduction-band (CB) offset in [110]- and [010]-oriented narrow n-type FinFETs with a model taking into account both strain and quantum confinement. We estimate the complete strain tensor for the scarce strain measurement points available with finite-element-method simulations of the thermal expansion effect. We found an inhomogeneous compressive strain that increases for smaller fin widths. The experimental CB offset is extracted from temperature-dependent transfer characteristics. The results show a lowering of the CB edge up to 40 meV for fin widths down to 5 nm. These experimental observations compare well with the model, and hence, the band offset can be explained by both quantum confinement and strain.

Design and Calculation of Cooling System to Eliminate Non-Uniform Heat Transfer on Concentration PV System (CPV)

With characteristics of rapid start-up, small heat resistance，uniform temperature and strong heat transfer ability, heat pipe has been used as a facility in cooling system of concentration photovoltaic system. Through numerical calculation and analysis, heat transfer characteristics of the cooling systems are carried out in this paper. Focusing on research of conventional rectangular fin and small fin fixed on cooling systems, and the heat pipe radiator that may adopted, the high-efficiency cooling system and method which are matched with the requirement of high energy flow density and notuniformity temperature are discussed. Finally, optimization design of the cooling system structure is suggested in the paper.

Influence of the louver and delta winglet geometry on the thermal hydraulic performance of a compound heat exchanger

Louvered fin heat exchangers are frequently used in heat transfer applications where air is one of the working fluids. By punching delta winglet vortex generators in the louvered fins, the size of the tube wakes can be reduced. The objective of this paper is to study the influence of the louver and delta winglet geometry on the thermal and hydraulic performance of such a compound heat exchanger. To this end, three-dimensional numerical simulations were performed. The effect of the louver and delta winglet geometry on the heat exchanger’s performance results in conflicting design requirements. A small fin pitch and large louver angle cause a strong flow deflection and thus a large contribution of the louvers. But in this case the generation of longitudinal vortices is suppressed and thus the effect of the delta winglets is small. Also the delta winglet geometry itself has an important influence. A well-considered geometry and location of the delta winglets is essential for an improved performance. Delta winglets completely located in the tube wakes should be avoided, because in this case they do not cause any enhancement effect.

Humans Running in Place on Water at Simulated Reduced Gravity

BackgroundOn Earth only a few legged species, such as water strider insects, some aquatic birds and lizards, can run on water. For most other species, including humans, this is precluded by body size and proportions, lack of appropriate appendages, and limited muscle power. However, if gravity is reduced to less than Earth’s gravity, running on water should require less muscle power. Here we use a hydrodynamic model to predict the gravity levels at which humans should be able to run on water. We test these predictions in the laboratory using a reduced gravity simulator.Methodology/Principal FindingsWe adapted a model equation, previously used by Glasheen and McMahon to explain the dynamics of Basilisk lizard, to predict the body mass, stride frequency and gravity necessary for a person to run on water. Progressive body-weight unloading of a person running in place on a wading pool confirmed the theoretical predictions that a person could run on water, at lunar (or lower) gravity levels using relatively small rigid fins. Three-dimensional motion capture of reflective markers on major joint centers showed that humans, similarly to the Basilisk Lizard and to the Western Grebe, keep the head-trunk segment at a nearly constant height, despite the high stride frequency and the intensive locomotor effort. Trunk stabilization at a nearly constant height differentiates running on water from other, more usual human gaits.Conclusions/SignificanceThe results showed that a hydrodynamic model of lizards running on water can also be applied to humans, despite the enormous difference in body size and morphology.

Divergent teratogenicity of agonists of retinoid X receptors in embryos of zebrafish (Danio rerio)

Zebrafish (Danio rerio) embryos were comparably exposed to seven known agonists of retinoid X receptors (RXRs) including two endogenous compounds (9-cis-retinoic acid and docosahexaenoic acid), four man-made selective ligands (LGD1069, SR11237, fluorobexarotene and CD3254), and a biocide (triphenyltin). The dominant phenotypes of malformation were sharp mouths and small caudal fins in 1mg/L SR11237-treated group after 5days exposure. 9-cis-retinoic acid and LGD1069 induced multiple malformations including small eyes, bent notochords, reduced brain, enlarged proctodaems, absence of fins, short tails and edema after 5days exposure. Fluorobexarotene and CD3254 induced similar phenotypes of malformations after 5days exposure at low concentration (20μg/L) to those after the 1st d exposure at high concentrations (50 and 100μg/L). Triphenlytin induced multiple malformations including deformed eyes, bent notochords, bent tails, and edema in hearts after 5days exposure at concentrations of 1-10μg Sn/L. In contrast, no discernible malformations were observed in triphenlytin-treated groups after each separate day exposure. These agonists not only showed different ability of teratogenicity but also induced different phenotypes of malformation in zebrafish embryos. In addition, the sensitive stages of zebrafish embryos were different in response to these agonists. Therefore, our results suggest that the agonists of RXRs had divergent teratogenicity in zebrafish embryos.