TMR Values Research Articles

Behavior, Intake, Digestion and Milk Yield of Early Lactation Holstein Dairy Cows with Two Levels of Environmental Exposure and Feeding Strategy.

Eighty-four autumn (ACS, n = 45)- and spring (SCS, n = 39)-calved multiparous early lactation Holstein cows were assigned to groups of either: (a) grazing + mixed ration (MR) during partial confinement in outdoor soil-bedded pens with shade (OD-GRZ); (b) grazing + MR during partial confinement in a compost-bedded pack barn with cooling (CB-GRZ); or (c) total confinement fed a totally mixed ration (CB-TMR) in a compost-bedded pack barn. Data were analyzed using the SAS MIXED procedure with significance at p ≤ 0.05. In both seasons, despite behavioral differences (p < 0.05) between the OD-GRZ and CB-GRZ groups (i.e., standing, first grazing meal length, bite rate), the milk and component yields, DM intake, microbial CP output (MCP) and NE efficiency were unaffected by the housing conditions, possibly due to mild weather conditions. The milk yield was substantially higher in the CB-TMR group versus the OD-TMR and CB-TMR groups (p < 0.01) in both ACS (~35%) and SCS (~20%) despite there being no intake differences, without any impact on milk component levels. In ACS, this was associated with a higher MCP, likely due to the higher nutritional value of TMR compared to pasture, which was not the case in SCS. In conclusion, the OD-GRZ group achieved the same milk production as the CB-GRZ group through behavior adaptation, under mild weather conditions, in both calving seasons. The CB-TMR group outperformed the grazing systems in both calving seasons, regardless of the MCP.

Field-free spin–orbit torque switching of magnetic tunnel junction structure based on two-dimensional van der Waals WTe2

In recent years, two-dimensional van der Waals (2D vdWs) heterostructures have attracted great research interest due to their great potential in fundamental physics research and spintronic devices (such as MTJs). Due to its excellent scalability, controllable magnetism and out-of-plane anisotropy, the compact nonvolatile memory controller (NV-MC) based on spintronics is expected to solve the memory bottle-neck problem. At present, a series of in-depth studies have been conducted on advanced 2D vdWs materials, such as MoS2, WSe2, and Fe3GeTe2 (FGT). The results show that the 2D vdWs materials have great TMR value and high SOT switching efficiency, both theoretically reported and experimentally verified. In the paper, a novel MTJ device based on the FGT/WTe2 heterostructure is proposed. In the absence of an external magnetic field, the magnetization direction of the MTJ free layer can still be reversed with certainty when the unipolar write current reaches about 5 mA. Moreover, the DMI effect generated between 2-D material/FM interfaces is also considered, which can promote the performance of SOT-MTJ without the external field. The reading reliability of SOT-MRAM is improved in comparison with the traditional CoFeB-based MTJ device.

Formulation of tissue maximum ratio for high energy photons using a medical electron linear accelerator

In Radiation Therapy efficiency and precision should be conserved so, there is a need to consider the parameters such as PDD and TMR. TMR is an important dosimetric function which can be measured experimentally and can be calculated from PDD by considering scatter factors. The purpose of this study was to compare and verify the accuracy of TMR data calculated using PDD with measured TMR data for 6 MV and 15 MV photon beams. The PDD values were measured at Source to Surface Distance, 100 cm for various radiation field sizes and depths. For the same field size, depth and energy, the TMR values were measured at Source to Axis Distance of 100 cm. The verification of the calculated TMR data was achieved by comparing it with the measured TMR data. The results had shown that; At the initial depths upto 7 cm, both the calculated and measured TMR were in good agreement, but the deviation increases as a function of depth, especially for the smaller field sizes. It can be concluded that; The calculated TMR values and RFA measured TMR data are having a good agreement and significant variations are indicated at increased depths of smaller field sizes.

Spin-Filter Magnetic Tunnel Junctions Based on A-Type Antiferromagnetic CrSBr with Giant Tunnel Magnetoresistance

CrSBr is a stable two-dimensional (2D) van der Waals (vdW) magnet with intralayer ferromagnetic and interlayer antiferromagnetic couplings. Here, we propose to use CrSBr as the barrier in spin-filter (sf) MTJ and establish the devices based on graphene/CrSBr/graphene structures. Employing density functional theory (DFT) combined with the nonequilibrium Green’s function approach, we investigated the transmission details, and the results show TMR values above 330%, 2 × 107% and 105% with two-, four- and six-layer CrSBr at zero bias, respectively. Subsequently, we systematically analyze the transmission spectra, transmission eigenstates, electrostatic potentials, band structures and local density of states to elaborate the underlying mechanism of the TMR effect in the sf-MTJs. Our results indicate the great prospect of CrSBr-based sf-MTJs in applications, and provide guidance for futural experiments.

Fermentation Quality and Nutritive Value of TMR Ensiled with Malt Whisky Distillery Byproducts as a Feed for Fattening Cattle

Fermentation Quality and Nutritive Value of TMR Ensiled with Malt Whisky Distillery Byproducts as a Feed for Fattening Cattle

Nutrient value of fermented TMR considering volatile components

Nutrient value of fermented TMR considering volatile components

A Dynamic Reference and Variation-Tolerant Sensing Circuit for Deep Nanometer STT-MRAM

STT-MRAM has received wide attention with its promising properties as the next generation memory. Over the years, with entering into nanometer technology, as process-temperature-voltage (PTV) variations being intensified increasingly, the read reliability of STT-MRAM becomes a critical problem. Therefore, it is highly required to design a sensing circuit with good sensing margin (SM) and anti-interference. This paper presents a dynamic reference (DR) and variation-tolerant sensing circuit for deep nanometer STT-MRAM. The circuit is composed with a clamp voltage generator (CVG), a dynamic reference generator (DRG), and a fully differential charge transfer amplifier (FDCTA). It is demonstrated that the proposed sensing circuit is capable of immunizing the PTV variations by increasing the sensing margin (SM) while lowering the read disturbance (RD). The sensing margin of the proposed circuit can be as high as 312 mV on condition of VDD to be 1.2 V and TMR value to be 150%.

Spin transport properties of magnetic tunnel junction based on zinc blende CrS

Abstract In this work, the spin transport characteristics of (001) zinc blende CrS/ZnSe/CrS magnetic tunnel junctions are studied with numerical simulations. The computations are performed with the density functional theory and nonequilibrium Green's function. Considering the electronegativity of different atoms, the MTJs with different interface atomic bonds are simulated. High TMR values (up to 2.4 × 1014%) are achieved. The results are illustrated with the transmission spectrum, device density of states, and the band structure. Moreover, the tunnel magnetic resistance ratio decreases with the increasing thickness of the ZnSe barrier. This work provides some physical insight and a preliminary performance assessment for the ZB CrS/ZnSe/CrS MTJ, which is promising for probable spintronic applications.

Association between feed sorting and the prevalence of metabolic disorders in Hungarian large-scale dairy herds.

This research communication describes the possible association between feed sorting and the risk of metabolic disorders in dairy cows. Feed sorting, that is selecting smaller size TMR particles over longer length fibers, can lead to imbalanced energy input. In addition, sorting can lead to lower nutritive value of leftover TMR. To detect a possible relationship between TMR sorting and the occurrence of metabolic disorders in large-scale herds, TMR separation and metabolic profile tests were performed in 22 Hungarian dairies. Feed sorting was defined as &gt;5% alteration in the mass proportion of any of the TMR fractions between the time of feed distribution and 5-6 h later. The prevalence of ketosis and subclinical acidosis differed between feed sorting and non-sorting groups. Inhomogeneous TMR seems to be a predisposing factor for imbalanced energy status. TMR homogeneity measurements should be routinely included in herd health monitoring.

The comparison between 6 MV Primus LINAC simulation output using EGSnrc and commissioning data

Introduction: Monte Carlo calculation method is considered to be the most accurate method for dose calculation in radiotherapy. The purpose of this research is comparison between 6 MV Primus LINAC simulation output with commissioning data using EGSnrc and build a Monte Carlo geometry of 6 MV Primus LINAC as realistically as possible. The BEAMnrc and DOSXYZnrc (EGSnrc package) Monte Carlo model of the LINAC head was used as a benchmark. Materials and Methods In the first part, the BEAMnrc was used for the designing of the LINAC treatment head. In the second part, dose calculation and for the design of 3D dose file were produced by DOSXYZnrc. The simulated PDD and beam profile obtained were compared with that calculated using commissioning data. Good agreement was found between calculated PDD (1·1%) and beam profile using Monte Carlo simulation and commissioning data. After validation, TPR20,10, TMR and Sp values were calculated in five different field. Results Good agreement was found between calculated values by using Monte Carlo simulation and commissioning data. Average differences for five field sizes in this approach is about 0·83% for Sp. For TPR20,10 differences for field sizes 10 × 10 cm2 is 0·29% and for TMR in five field sizes, the average value is ~ 1·6%. Conclusion: In conclusion, the BEAMnrc and DOSXYZnrc codes package have very good accuracy in calculating dose distribution for 6 MV photon beam and it can be considered as a promising method for patient dose calculations and also the Monte Carlo model of primus linear accelerator built in this study can be used as method to calculate the dose distribution for cancer patients.

Influence of the surface morphology on the magnetoresistance of ultrathin films of ferromagnetic metals and their alloys

The microstructure, morphology and magnetoresistive properties of as-deposited and annealed at 700K discontinuous films of ferromagnetic metals and their alloys are investigated. It is established that the isotropic field dependences stemming from the spin-dependent electron tunneling between ferromagnetic islands are observed for as-deposited Co films with an effective thickness (d) of dCo = 5-25 nm as well as for Fe films (dFe = 10-30 nm). It is shown that the maximum values of the isotropic magnetoresistance take place in the case when the size of the islands is equal to 3-5nm and the width of the dielectric barrier between them is 1-3nm. The maximum TMR values for the films annealed at 700 K are obtained when the dielectric barrier is 2-5 nm wide.

End-use quality characteristics of hermetically stored paddy

Four paddy varieties (Bg 352, Bg 300, Bg 358 and Bg 360) were stored in hermetic IRRI bags and common woven polyethylene bags (polybags) at room temperature either uninfested or infested with rice weevils (Sitophilus oryzae (L.)). After 9 months of storage, samples were tested for insect mortality, gas contents, moisture content (m.c.), thousand grain mass (TGM), porosity, hardness, whiteness, total milled rice yield (TMR), head rice yield (HRY), gelatinization temperature, amylose (AC), crude protein (CP), crude fat, free fatty acid (FFA), thiamine and niacin contents and sensory characteristics. These properties after storage were compared with their initial condition. The oxygen content dropped from 21% to 7% and 13.8% for infested and uninfested IRRI bag samples, respectively. The results showed that m.c., of the IRRI bag samples increased significantly (P < 0.05) by 5% when compared to the initial sample but it increased by 15% in polybag stored samples. After 9 months, dry matter loss (DM) was 65% higher in polybag than IRRI bag samples. Highest DM loss was observed in Bg 300 and the lowest DM loss was observed in Bg 358 and Bg 360. Paddy samples stored in IRRI bags showed reduced whiteness compared to polybag stored samples. Storage in IRRI bags significantly increased (P < 0.05) TMR, HRY, AC and sensory values compared to polybag samples. However, paddy samples stored in polybags significantly increased (P < 0.05) their CP and FFA contents while decreasing sensory values, thiamine and niacin contents. The FFA value of polybag samples was 2.5 times higher than IRRI bag samples. Hermetic storage of dry paddy improved overall paddy quality but different end-use quality parameters were observed in the two paddy grain types of short round (Bg 352 and Bg 300) or intermediate bold (Bg 358 and Bg 360).

Experimental investigations of SiO2 based ferrite magnetic tunnel junction

• CoFe 2 O 4 /SiO 2 /Co–NiFe 2 O 4 magnetic junction was fabricated using RF/DC sputtering. • Spin transport through nanostructure silicon oxide with ferrite as free and pinned layer is our first report. • Magnetization studies were done to justify the free layer and pinned layer for our multilayer. • Magnetoresistance behavior shows a sharp discriminating between parallel and antiparallel alignment with TMR value of 16%. We report experimental results of ferrite based magnetic tunnel junction. Ferrite junction and spin transport through SiO 2 were interesting since they can readily replace the conventional electronics. We fabricated a cobalt ferrite/SiO 2 /cobalt nickel ferrite based magnetic tunnel junction over a copper coated n-silicon substrate using a RF/DC magnetron sputtering. The tunneling magnetoresistance shows a very good response to applied field and we achieved a TMR of about 16%. Although theoretically it was predicted infinite TMR for half metallic ferromagnetic junction, the deviation was explained on the basis of incoherent scattering along the interfaces.

First-principles Study of Bias Effect on Magnetoresistance of Fe/MgO/Fe Tunnel Junctions

ABSTRACTWe studied the transport properties of the Fe/MgO/Fe and Fe/Ag/MgO/Ag/Fe magnetic tunnel junctions (MTJs) with 13-layer MgO barrier under bias voltage based on first-principles calculations. Our results showed that two features determine the TMR value decreases with bias of Fe/MgO/Fe MTJ: (1) interfacial states lying at 1.06 eV in spin down channel (2) the energy level of the spin down Δ1 band of the Fe electrode. Our results showed that an inserted Ag mono-layer at Fe/MgO interface can remarkably improve the TMR effect at a high bias voltage.

The Prospect of STT-RAM Scaling From Readability Perspective

Due to its fast access time, high integration density, nonvolatility and good CMOS compatibility, Spin-transfer torque random access memory (STT-RAM) becomes one promising technology for the memory hierarchy of the next-generation computing systems. In recent years, tremendous efforts have been made to reduce the switching current of magnetic tunneling junction (MTJ) for write performance and energy improvement. However, the success of write current reduction makes the STT-RAM read stability issue more prominent during the scaling of STT-RAM: following the decrease in MTJ switching current, the read current must scale accordingly to keep the disturbance on the MTJ resistance state at a minimum level. If the MTJ resistance and/or TMR values do not increase proportionally, the effective sense margin of STT-RAM will degrade, leading to a higher sensing error rate. In this work, we quantitatively analyzed the impacts of existing MTJ scaling rule on the readability STT-RAM, including both read disturbance and sensing errors. We also presented the importance of selecting an optimal read current for maintaining the readability of STT-RAM under the current scaling trend.

Analysis of parametric histogram from dynamic contrast‐enhanced MRI: application in evaluating brain tumor response to radiotherapy

Dynamic contrast-enhanced MRI (DCE MRI) has been used to study tumor response to treatment for many years. In this study, the modified full width at half-maximum (mFWHM), calculated from the wash-in slope histogram, is proposed as a parameter for the evaluation of changes in tumor heterogeneity which respond to radiotherapy. Twenty-five patients with brain tumors were evaluated and divided into the nonresponder group (n = 11) and the responder group (n = 14) according to the Response Evaluation Criteria in Solid Tumors (RECIST). All selected tumors were evaluated by mFWHM ratios of post- to pre-therapy (the ratio was defined as the therapeutic mFWHM ratio, TMR). The changes in kurtosis of the histograms and the averaged K(trans) within a tumor were also calculated for comparison. The receiver operating characteristic analysis and Kaplan-Meier curves were used to examine the diagnosis ability. The TMR values were significantly higher in nonresponders than in responders (p < 0.001). When compared with the other two parameters, the proposed method also demonstrated better sensitivity and specificity. When adopting the TMR for the estimation of prognosis after therapy, there was a significant difference between the population survival curves. In conclusion, the derived mFWHM reflects tumor heterogeneity, and the ability to depict patient survival probability from TMR corresponds well with that from RECIST. The results reveal that, in brain tumors, progression may be exhibited not only by tumor size, but also by tumor heterogeneity.

Magnetic Properties of Epitaxial Discontinuous Fe/MgO Multilayers

We report magnetic, dynamic and transport properties of discontinuous metal-insulator multilayers Fe/MgO grown on amorphous Corning glass and single-crystalline MgO (001) substrates. The films of structure Substrate/MgO (3 nm)/[Fe (0.6 nm)/MgO (3.0 nm)] x 10 were prepared in ultra-high vacuum conditions using Pulsed Laser Deposition. It was shown that conditions of epitaxial growth are favorable for MgO substrates. As a result a substantial increase of tunneling magnetoresistance caused by spin-filtering effect was observed and reasonably theoretically explained. The value of TMR - 9.2% at room temperature in 18 kOe magnetic field is three times higher comparing to that for the samples grown on Corning glass substrates.

Valuation of magnetic non-collinear effects on FM/trans-PA/FM systems

With Green's function method and single band tight binding Hamiltonian, we calculated coherence transport for trans-polyacetylene (T-PA) systems placed between ferromagnetic electrodes with non-collinear ones. Ferromagnetic electrodes are of two kinds: Fe and Ni. With increasing TMR angle it increases to a maximum at θ=π degree. Electric field on molecule causes a change in the value of TMR. Types of ferromagnetic electrodes also affect the value of TMR, which is caused by density of states related to electrodes.

Magnetotransport through graphene spin valves

We present a theoretical study on the spin-dependent transport through a spin valve consisting of graphene sandwiched between two magnetic leads with an arbitrary orientation of the lead magnetization. No gate voltage is applied. Using Keldysh’s nonequilibrium Green’s function method we show that, in absence of external magnetic fields, the current-voltage curves are nonlinear. Around zero bias the differential conductance versus bias voltage possesses a strong dip. The zero-bias anomaly in the tunnel magnetoresistance TMR is affected strongly by the leads’ spin polarization. Depending on the value of the bias-voltage TMR exhibits a behavior ranging from an insulating to a metallic type. In presence of a static external magnetic field the differential conductance and TMR as a function of the bias voltage and the strength of the magnetic field show periodic oscillations due to Landau-level crossings. We also inspect the effects of the temperature and the polarization degrees on the differential conductance and TMR.

Microstructural and magnetic properties of CoFeZr films and the tunnel magnetoresistance behaviors of the magnetic tunnel junctions with amorphous CoFeZr ferromagnetic layers

We investigated the composition dependence of the microstructure and magnetic properties of Co 90Fe 10–Zr film and the thermal and structural stability of MTJs with CoFeZr layers. As the Zr concentration in the Co 90Fe 10–Zr film increased, the grain size decreased rapidly, and the alloy films became a homogeneous amorphous phase when the concentration of Zr exceeded 15 at%. The TMR ratio of the MTJs with Co 90Fe 10 layers decreased when the samples were annealed at a temperature above 300 °C, whereas that of the MTJs with amorphous CoFeZr layers only started to decrease when they were annealed at a temperature above 350 °C. The MTJs with CoFeZr layers retained a significant TMR value of 28%, even after annealing at 450 °C. The enhanced structural quality of the interfaces improved the thermal stability of the MTJs with amorphous CoFeZr layers.