Hybrid Research Articles

Momentum-dependent local ansatz approach to correlated electrons

The wavefunction method provides us with a useful tool to describe electron correlations in solids at the ground state. In this paper we review the recent development of the momentum-dependent local ansatz (MLA) wavefunction. It is constructed by taking into account two-particle excited states projected onto the local orbitals, and the momentum-dependent amplitudes of these states are chosen as variational parameters. The MLA describes accurately correlated electron states from the weak to the intermediate Coulomb interaction regime in infinite dimensions, and works well even in the strongly correlated region by introducing a new starting wavefunction called the hybrid (HB) wavefunction. The MLA-HB is therefore shown to overcome the limitation of the original local ansatz (LA) wavefunction as well as the Gutzwiller wavefunction. In particular, the calculated quasiparticle weight versus Coulomb interaction curve is shown to be close to that obtained by the numerical renormalization group approach. It is also shown that the MLA is applicable to the first-principles Hamiltonian.

PERFORMANCE CHARACTERISTICS OF A HYBRID WING FOR UAV

Unmanned aerial vehicles (UAV) have become importan t in the surveillance sector of various governments . Their adavatage of high end technology and minimal risk of human life has bthe major boost with respect to the research as sociated with UAVs. Over the years, the designing and optimization of the aerody namics of these vehicles has gained lot of importan ce owing to the increasing urge to develop UAVs with better stability and endurance at subsonic speeds. Since the aircraft should have various performance characteristics as per the desired aerodyanamic req uirements, it has been a challenging task to incor porate these characteristics through the use of a single homogeneous airfoil for the wing. With regard to the above discussion, thi s work deals with the comparison of performance characteristics of a hybr id wing consiting of two airfoil sections combined into a single wing and those of wings with each of the two homogeneous airfoil sect ions. The optimal wing dimensions for the surveilen ce UAV was obtained through MATLAB. Three separate models consiting of the hy brid wing, S1223 and E420 were developed through So lid Edge and imported into Fluent. Later, the wing models were subjected to aerodynamic analysis through the implementation of parameters experienced by the wing during the actual flight. The results obta ined were compared in order to draw a conclusion re garding the advantages of using a hybrid wing as against the usage of wings w ith homogeneous airfoil.

A Prospective Propensity Matched Cohort Analysis of Minimally Invasive (MIS), Hybrid (HYB), and Open Spine Surgery (OPEN) for the Treatment of Adult Spinal Deformity (ASD)

A Prospective Propensity Matched Cohort Analysis of Minimally Invasive (MIS), Hybrid (HYB), and Open Spine Surgery (OPEN) for the Treatment of Adult Spinal Deformity (ASD)

Momentum Dependent Local-Ansatz with Hybrid Wavefunction from Weak to Strong Electron Correlations

The variational theory of momentum dependent local-ansatz (MLA) has been generalized by introducing a hybrid (HB) wavefunction as a starting wavefunction, whose potential can flexibly change from the Hartree–Fock type to the alloy-analogy type by varying a weighting factor from zero to one. Numerical results based on the half-filled band Hubbard model on the hypercubic lattice in infinite dimensions show up that the new wavefunction yields the ground-state energy lower than that of the Gutzwiller wavefunction (GW) in the whole Coulomb interaction regime. Calculated double occupation number is smaller than the result of the GW in the weak Coulomb interaction regime, and remains finite in the strong regime. Furthermore, the momentum distribution shows a distinct momentum dependence, which is qualitatively different from that of the GW.

New Sparse Matrix Storage Format to Improve The Performance of Total SPMV Time

Graphics Processing Units (GPUs) are massive data parallel processors. High performance comes only at the cost of identifying data parallelism in the applications while using data parallel processors like GPU. This is an easy effort for applications that have regular memory access and high computation intensity. GPUs are equally attractive for sparse matrix vector multiplications (SPMV for short) that have irregular memory access. SPMV is an important computation in most of the scientific and engineering applications and scaling the performance, bandwidth utilization and compute intensity (ratio of computation to the data access) of SPMV computation is a priority in both academia and industry. There are various data structures and access patterns proposed for sparse matrix representation on GPUs and optimizations and improvements on these data structures is a continuous effort. This paper proposes a new format for the sparse matrix representation that reduces the data organization time and the memory transfer time from CPU to GPU for the memory bound SPMV computation. The BLSI (Bit Level Single Indexing) sparse matrix representation is up to 204\% faster than COO (Co-ordinate), 104\% faster than CSR (Compressed Sparse Row) and 217\% faster than HYB (Hybrid) formats in memory transfer time from CPU to GPU. The proposed sparse matrix format is implemented in CUDA-C on CUDA (Compute Unified Device Architecture) supported NVIDIA graphics cards.

Removal of arsenic and selenium compounds from aqueous media by using TiO2 photocatalytic reaction

A new method for the removal of arsenite [As(III)] and selenate [Se(VI)], which are difficult to remove by conventional water treatment methods from aqueous media, was investigated. This method involves the use of photocatalytic oxidation of As(III) and photocatalytic reduction of Se(VI). Also, a novel TiO2–adsorbent hybrid (HYB) which has photocatalyst sites and adsorbent sites on the same particle was developed. When the removal of As(III) by use of photocatalyst–adsorbent system and the HYB system was carried out, As(III) was effectively removed from aqueous phase. Moreover, with the removal of Se(VI) by using photocatalytic reduction, Se(VI) could also be removed from aqueous phase under the photocatalyst–adsorbent system and the HYB system, even if the concentration of a hole scavenger formic acid was reduced.

Separation and determination of dimethylarsenate in natural waters

A simple and efficient method for separation and determination of dimethylarsenate DMAs(V) was developed in this work. Two resins, a strong base anion exchange (SBAE) resin and iron-oxide coated hybrid (HY) resin were tested. By simple adjusting pH value of water at 7.00, DMAs(V) passed through the HY column without any changes, while all other arsenic species [inorganic arsenic and monomethylarsonate, MMAs(V)] were quantitatively bonded on HY resin. The resin capacity was calculated according to the breakthrough points in a fixed bed flow system. At pH 7.00 the HY resins bonded more than 4150 ?g g-1 of As(III), 3500 ?g g-1 of As(V) and 1500 ?g g1 of MMAs(V). Arsenic adsorption behavior in the presence of impurities showed tolerance with the respect to potential interference of anions commonly found in natural water. DMAs(V) was determined in the effluent by ICP-MS. The detection limit was 0.03 ?g L?1 and relative standard deviation (RSD) was between 1.1?7.5 %. Proposed method was established performing standard procedures: with external standard, certified reference material and the standard addition method.

Surface scattering velocities in III-nitride quantum well laser structures via the emission of hybrid phonons

We have theoretically and numerically studied nitride-based quantum well (QW) laser structures. More specifically, we have used a QW made with III-nitride where the width of the barrier region is large relative to the electron mean free path, and we have calculated the electron surface capture velocities by considering an electron flux which is captured into the well region. The process is assisted by the emission of the longitudinal optical phonons as predicted by the hybrid (HB) model. The results of surface capture velocities via the emission of HB phonons are compared to the emission of the dielectric continuum phonons (Zakhleniuk et al 1999 Phys. Status Solidi a 176 79). Our investigation shows that the two different phonon models predict almost the same results for the non-retarded limit. Furthermore, the surface capture velocities strongly depend on the size of the structure and the heterostructure materials. Lastly, a comparison to the recent experimental values shows that our model could accurately describe the experimentally measured parameters of the quantum capture processes.

Separation and determination of arsenic species in water by selective exchange and hybrid resins

A simple and efficient method for separation and determination of inorganic arsenic (iAs) and organic arsenic (oAs) in drinking, natural and wastewater was developed. If arsenic is present in water prevailing forms are inorganic acids of As(III) and As(V). oAs can be found in traces as monomethylarsenic acid, MMA(V), and dimethylarsenic acid, DMAs(V). Three types of resins: a strong base anion exchange (SBAE) and two hybrid (HY) resins: HY-Fe and HY-AgCl, based on the activity of hydrated iron oxides and a silver chloride were investigated. It was found that the sorption processes (ion exchange, adsorption and chemisorptions) of arsenic species on SBAE (ion exchange) and HY resins depend on pH values of water. The quantitative separation of molecular and ionic forms of iAs and oAs was achieved by SBAE and pH adjustment, the molecular form of As(III) that exists in the water at pH <8.0 was not bonded with SBAE, which was convenient for direct determination of As(III) concentration in the effluent. HY-Fe resin retained all arsenic species except DMAs(V), which makes possible direct measurements of this specie in the effluent. HY-AgCl resin retained all iAs which was convenient for direct determination of oAs species concentration in the effluent. The selective bonding of arsenic species on three types of resins makes possible the development of the procedure for measuring and calculation of all arsenic species in water. In order to determine capacity of resins the preliminary investigations were performed in batch system and fixed bed flow system. Resin capacities were calculated according to breakthrough points in a fixed bed flow system which is the first step in designing of solid phase extraction (SPE) module for arsenic speciation separation and determination. Arsenic adsorption behavior in the presence of impurities showed tolerance with the respect to potential interference of anionic compounds commonly found in natural water. Proposed method was established performing standard procedures: with external standard, certified reference material and standard addition method. Two analytical techniques: the inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectroscopy-hydride generation (AAS-GH) were comparatively applied for the determination of arsenic in all arsenic species in water. ICP-MS detection limit was 0.2 μg L −1 and relative standard deviation (RSD) of all arsenic species investigated was between 3.5 and 5.1%.

Cloning and sequencing of IGF-Ⅰb 3′cDNA in &lt;I&gt;Oreochromis niloticus, Sarotherodon melanotheron&lt;/I&gt; and their hybrid

Aiming at exploring the sequence differences of IGF-Ⅰ gene of Nile tilapia(Oreochromis niloticus NewGifts,ON),black-chin tilapia(Sarotherodon melanotheron,SM) and their First Generation of Hybrid(HB),investigating the relationships between the great differences of salt-resistant property among the three genotypes,we cloned partial cDNA fragments of insulin-like growth factor Ⅰ(IGF-Ⅰ) from gill extracts through rapid amplification of 3' cDNA ends(3'RACE)methods.The results demonstrated to be the IGF-Ⅰb gene cDNAs with length of 1076 bp,1075 bp and 1079 bp respectively and comprising of a stop codon,a 546 bp open reading frame(ORF) encoding a 182 amino acid peptides(aa),and 3'-untranslated regions(3'-UTR).The deduced amino acid sequence of IGF-Ⅰb precursor is composed of signal peptide,mature peptide(including conserved B,C,A and D domains consisting of 29-aa,10-aa,21-aa and 8-aa respectively)and E domain of 70aa.Results of the predicted secondary structures were typed asmixed patterns.The results of multiple alignments showed highly homologous with 75.8% to 100% amino acid identity.The B and A domains are highly conserved in all of the allied species.There are 2aa-deletion between No.82 and 83 sites in C domain,3aa and 1aa-deletion next to NO.131 and No.159 site,respectively.Ala/Pro substitution occurred at No.133 of E domain of black-chin tilapia compared with ON and HB,which is identical to Oreochromis mossambicus and Oreochromis urolepis hornorum.We presumed that the differences of saltresistant property of ON,SM and HB may be due to the alterative splicing of the IGF-Ⅰ E domain.

Proposal of Flux Concentrated Radial and Axial Magnetic Bearings

New flux concentrated hybrid (HB) type radial and axial magnetic bearings are proposed in this paper. It is intended to use ferrite permanent magnet (PM) for producing high bias flux. The capability of proposed magnetic bearings is confirmed using commercial FEM code “ANSYS”. The results show high possibility with less expensive PMs.

Determination of inorganic arsenic species in natural waters—Benefits of separation and preconcentration on ion exchange and hybrid resins

A simple method for the separation and determination of inorganic arsenic (iAs) species in natural and drinking water was developed. Procedures for sample preparation, separation of As(III) and As(V) species and preconcentration of the total iAs on fixed bed columns were defined. Two resins, a strong base anion exchange (SBAE) resin and a hybrid (HY) resin were utilized. The inductively-coupled plasma-mass spectrometry method was applied as the analytical method for the determination of the arsenic concentration in water. The governing factors for the ion exchange/sorption of arsenic on resins in a batch and a fixed bed flow system were analyzed and compared. Acidity of the water, which plays an important role in the control of the ionic or molecular forms of arsenic species, was beneficial for the separation; by adjusting the pH values to less than 8.00, the SBAE resin separated As(V) from As(III) in water by retaining As(V) and allowing As(III) to pass through. The sorption activity of the hydrated iron oxide particles integrated into the HY resin was beneficial for bonding of all iAs species over a wide range of pH values from 5.00 to 11.00. The resin capacities were calculated according to the breakthrough points in a fixed bed flow system. At pH 7.50, the SBAE resin bound more than 370 μg g −1 of As(V) while the HY resin bound more than 4150 μg g −1 of As(III) and more than 3500 μg g −1 of As(V). The high capacities and selectivity of the resins were considered as advantageous for the development and application of two procedures, one for the separation and determination of As(III) (with SBAE) and the other for the preconcentration and determination of the total arsenic (with HY resin). Methods were established through basic analytical procedures (with external standards, certified reference materials and the standard addition method) and by the parallel analysis of some samples using the atomic absorption spectrometry-hydride generation technique. The analytical properties of both procedures were similar: the limit of detection was 0.24 μg L −1, the limit of quantification was 0.80 μg L −1 and the relative standard deviations for samples with a content of arsenic from 10.00 to 300.0 μg L −1 ranged from 1.1 to 5.8%. The interference effects of anions commonly found in water and some organic species which can be present in water were found to be negligible. Verification with certified reference materials proved that the experimental concentrations found for model solutions and real samples were in agreement with the certified values.

Fertilizer response for hybrid and open-pollinated canola and economic optimal nutrient levels

Hybrid (HY) canola (Brassica napus L.) produces a higher seed yield than open-pollinated (OP) canola. While it is expected higher-yielding HY canola may require higher total available nutrients, especially nitrogen (N), the evidence is not conclusive. This study used canola yield data from several site-years and fertility experiments to determine whether HY and OP canola types require different rates of total available N (TAN) and total available phosphorus (TAP). The yield response of the two canola genotypes to TAP was the same, but for TAN the yield response was greater for HY canola. The quadratic yield response results were confirmed using three plateau equations. Optimal TAN for HY canola was higher than for OP canola. Soil test laboratories and producers growing HY canola need to modify N fertility for HY canola, compared with OP canola for which most of the current N fertilizer recommendations were developed. Key words: Economics, fertilizer, yield response, canola, hybrid, open-pollinated

The Profitability of Seeding the F2 Generation of Hybrid Canola

The high cost of hybrid (HY) canola (Brassica napus L.) seed has some producers considering F2 generation hybrid farm‐saved seed (HY‐FSS), or open‐pollinated (OP) varieties (both certified and farm‐saved seed). The net return (NR) of different varieties, genetic backgrounds, seeding rates, seed treatments, and seed sizing was evaluated from three experiments over eight site‐years of field data from western Canada. One set of experiments included variety, genetic background and seeding rate, while another included seed treatment, genetic background and seed sizing. The experiments used randomized complete block designs. The NR accounted for yield, green seed price discount, seed costs, and other production costs. Analysis of variance indicated certified F1 hybrid seed (HYC) was more profitable than HY‐FSS (15%, P = 0.0057) and OP (22%, P = 0.0001). With delayed weed control, NR was lower for HYC and not statistically different than HY‐FSS. Higher seeding rates and seed sizing for HY‐FSS did not increase NR compared to HYC. The findings of this study support the use of HYC canola seed, especially at high canola prices. Canola producers will not increase their NR by using HY‐FSS or OP seed to reduce their seed cost because the lost value of production exceeds the higher cost of HYC seed.

Seeding Rate, Seeding Depth, and Cultivar Influence on Spring Canola Performance in the Northern Great Plains

Rapid expansion of canola (Brassica napus L.) production in the Northern Great Plains has raised questions on the response of cultivars to seeding rate and depth. Field research was conducted at four North Dakota locations in 1999, 2000, and 2001 evaluating a small‐seeded open‐pollinated (OP) and a large‐seeded hybrid (HYB) cultivar at two seeding depths (19 and 38 mm) both at four seeding rates (54, 108, 162, and 216) pure live seed (PLS) m−2. Percent emergence and plant density was significantly greater at the 19‐mm seeding depth compared with the 38‐mm seeding depth at six of eight environments. Seeding depth effect on seed yield was inconsistent among environments. Seed yield increased with increasing seeding rates in all but two environments. Hybrid and OP cultivars responded similarly to seeding rate for all characteristics measured, except days to first flower and net economic return per hectare. The net economic return per hectare, based on seed cost and grain value where HYB seed typically costs twice that of OP, was greatest at seeding rates for the large‐seeded HYB at 108 PLS m−2, and at 162 PLS m−2 for the small‐seeded OP cultivar. The HYB cultivar had a 24% greater seed yield than the OP cultivar and a 14% greater net economic return per hectare. Producers need to consider cultivar type and seed cost to determine optimum seeding rate to obtain maximum economic return.

CNT-based organic-inorganic composite materials with optoelectronic functionality

This paper focuses on the fabrication of organic-inorganic composite materials with optoelectronic functionality based on carbon nanotubes (CNTs) by chemical and physical modifications. The one-dimensionally (1D) ordered composites of rare earth phthalocyanine compounds (RePc2) encapsulated by MWCNTs were obtained using a simple capillary filling method. The CNT-templated assembly of RePc2 nanowires was performed by a phase-separation method. Two other kinds of organic-inorganic 1D-ordered optoelectronic composites were prepared using the template method: coating MWCNTs with a fluorescent poly(tripheny lamine) related co-polymer can be realized via a facile phase-separation strategy: 1D hy brid of bamboo-shaped CNTs covalently bound to RePc2. The relationship between the microstructure of the obtained 1D-ordered composites and optoelectronic properties was studied, and it was found that these ordered composites exhibited enhanced photoconductivity due to the charge transfer between the composite components.

Seeding rate, fertilizer level and disease management effects on hybrid versus open pollinated canola (Brassica napus L.)

New canola cultivars have much higher yield potential than conventional canola cultivars and changes in production practices may be needed to achieve optimum yield from these cultivars. Studies were conducted to investigate the influence of seeding rates (2.8, 5.6 and 8.4 kg ha-1), fertilizer level (67% – low, 100% – medium, 133% – high of the commercial recommendation) and fungicide application on growth, dry matter accumulation, seed yield and seed quality using two high-yielding canola cultivars [cv. Quantum, open pollinated (OP), and cv. Invigor™, hybrid (HYB)]. The studies were conducted from 1999 to 2001 at three sites in the Parkland region of the Canadian prairies. The two cultivars did not differ in their responses to seeding and fertilizer rates, or fungicide application. Plant density was lower for the HYB than the OP because the HYB had larger seeds, with fewer seeds per kilogram. Emergence declined slightly at high fertilizer levels in some site-years due to fertilizer induced seedling damage, but increased with seeding rate. Time to onset of flowering and maturity showed no consistent influence of cultivar, and tended to be somewhat prolonged with an increase in fertilizer levels, but reduced by an increase in seeding rate. On average, the HYB produced 822 kg ha-1 more biomass and 200 kg ha-1 more seed yield than the OP. Sclerotinia stem rot incidence was very low, except at Melfort in 2000, and fungicide application generally failed to benefit the crop. Seed yield was generally increased when seeding rate was increased, with the largest increase occurring from 2.8 to 5.8 kg ha-1. Seed yield responses to the high rates of seeding or fertilizer only occurred where both inputs were at the highest level, indicating that the optimum level of one was dependent upon the level of the other input. Oil and protein concentration in the seed was higher for the HYB than the OP. High fertilizer levels generally increased the total yield of biomass and seed, and protein concentration in the seed, but usually reduced oil concentration in the seed. Increased seeding rate resulted in a small increase in oil concentration and a small reduction in protein concentration in the seed. Net returns were greatest and least variable for the HYB cultivar. Overall, the HYB performed better than the OP, and the full economic value of high-yielding canola cultivars was only realized when fertilizer and seeding rates were at or above the current recommended rates. Key words: Canola (Brassica napus L.), fertilizer rate, fungicide, hybrid canola, oil content, open pollinated canola, protein content, seeding rate, seed quality, yield

Muscle Maintenance by Volitional Contraction against Applied Electrical Stimulation

Muscle training exercises are needed for muscular endurance during spaceflight. This study was designed to investigate effects of volitional contraction against applied electrical stimulation on the muscular endurance of the proximal upper extremity. Thirteen healthy sedentary men were allocated into two groups. One group participated in a hybrid (HYB) exercise regimen in which the biceps brachii was stimulated as he volitionally extended his elbow, and the triceps brachii was stimulated as the volitionally flexed his elbow. The second group underwent a similar regimen in which the electrical stimulation (ELS) was alternatively delivered to the biceps brachii and then to the triceps brachii with the limb fixed. Forty-second surface electromyography (EMG) recordings at 50% maximum voluntary contraction (MVC) were made as baseline data at just before starting the training regimen, and again conclusion. The median frequency (MF) and mean power frequency (MPF) slopes with time were determined using power spectrum analysis. There were statistical significance only for the triceps in which the MF and MPF slopes in the HYB Group became less negative over the period of study (from -45.7+/-14.7 and -47.0+/-8.6%/min at baseline to -36.9+/-10.7 and -36.8+/-7.0%/min at the end of training, respectively). The corresponding values for these slopes in the ELS Group showed opposite tends with less marked changes of borderline significance for MF and of statistical significance for MPF. These results suggested that the HYB exercise regimen was capable of producing an improvement in triceps but not biceps brachii.

A robust algorithm for calculating the spatial deformations of rods without tensile strength

A globally convergent iterative algorithm for computing the spatial deformations of elastic beams without tensile strength is presented. The core of the algorithm is an iterative scheme (consistent with the classical Kirchhoff rod theo ry) for locating the neutral axis and thus for determining the curvature. We prove uniqueness and local stability for the general case and global stability for symmetric cross sections. The scheme is embedded in an iteration-free global boundary value problem solver (the so-called Parallel Hybr id Algorithm) to determine spatial equilibrium configurations. The obvious applications are steel reinforced concrete beams and columns, with or without pre-stressing.

705 永久磁石内蔵アキシャル磁気軸受の開発(関東支部 茨城講演会)

Magnetic bearing can support the rotor without physical contact. Hybrid (HB) type magnetic bearing is recognized as an efficient one. However, the permanent magnet (PM) should be installed between the two radial magnetic bearings. This construction requires thick magnetic circuit between them which causes heavy structure. A new IPM type HB magnetic bearing has been proposed which has compact magnetic circuit, small construction and low cost. However, they could not control axial direction. In this paper, a new type of axial magnetic bearing is proposed and designed.