Direct Experimental Methods Research Articles

IMPLICATIONS OF COMMUNITY SERVICE: FINANCIAL STATEMENT PRESENTATION TRAINING FOR ACCOUNTING MGMP TEACHERS TANGERANG CITY

The purpose of this community service implication is to provide financial report presentation training for Tangerang City accounting MGMP teachers to increase knowledge and competency of financial accounting standards that apply in Indonesia. Implications of community service using direct experimental methods to determine the effectiveness of training. Collecting data through discussions and direct interviews to gain an understanding of teachers' perceptions and experiences. The results of this activity showed the success of increasing the knowledge and competence of teachers significantly. Teachers are more confident in teaching the presentation of financial reports in accordance with accounting standards applicable in Indonesia. An interactive and relevant teaching system provides broad knowledge and insight into the presentation of financial reports which is useful for teachers. Besides that, it improves practical skills that can be directly applied in teaching. The conclusion from the implications of this training, apart from increasing knowledge and competency for teachers, also contributes to improving the quality of accounting teaching and education in Tangerang City. The implications of training in presenting financial reports are very important to understand the use of accounting standards in Indonesia for industry.

The Impact of Barns Microclimate Modification on the Beef Cattles Physiological Responses Raised in the Peatlands of Central Kalimantan

This study aimed to evaluate the effect of cattle barns microclimate modification on the physiological response of beef cattles reared on peatland. This study used direct observation and experimental research methods. Microclimate modification is done by using asbestos material, gable roof type and roof height ≥3.5 meters, and vegetation arrangement. Data were collected through measurements of microclimatic parameters and physiological responses in the morning (06.30–07.30), at noon (11.30–12.30), and in the afternoon (16.30–17.30), with measurement intervals every month. The number of cattle barns observed was 46 units. The physiological parameter measurements involved 124 female beef cattle, consisting of 70 Bali and 54 crossbred cattle with physiological stages, gestating cows and lactation period. The results showed that modifying cattle barns and the surrounding environment can reduce the microclimate in the cattle barn as indicated by a decrease in THI from emergency to dangerous levels during the noondayand from dangerous to caution levels in the afternoon. The improvement in microclimate conditions was also followed by a decrease in the level of heat stress as indicated by a decrease in the physiological responses of cows.

Imaging of atomic stress at grain boundaries based on machine learning

The mechanical behaviors of crystalline materials, in particular the atomic scale deformation and failure processes, are strongly influenced by the local atomic stress near crystalline defects such as vacancies, dislocations and grain boundaries (GBs). Modern electron microscopy techniques have achieved unprecedented capabilities to image the internal microstructure of crystalline materials with atomic resolution. In comparison, our ability to map the corresponding atomic stress field, especially at grain boundaries with complex atomic structures, remains lagging behind due to the lack of direct experimental methods for stress measurement. Here, we propose a machine learning-based framework to realize atomic structure-stress (Atom-S2) mapping based on in situ transmission electron microscopy images. We demonstrate that, with optimized anti-noise performance and generalization ability, the Atom-S2 framework enables quantitative mapping of atomic stress in symmetrical tilt GBs, twin boundaries (TBs) as well as general GBs with changing curvature in crystalline metals. Moreover, the Atom-S2 can help understand, interpret and predict grain boundary stress evolution and plastic deformation mechanisms based on high-resolution transmission electron microscopy images, which provides a powerful tool to study atomic scale deformation behaviors and holds promises for accelerating materials design through defect engineering.

Myocardial viscoelasticity impairs late-filling in working myocardial slice preparations.

Heart failure with preserved ejection fraction (HFpEF) is linked to diabetes and obesity and has become the dominant form of heart failure in western cultures. Both impaired relaxation and increased myocardial stiffness impede ventricular filling which manifests in patients as exercise intolerance early in disease progression. The observation of elevated end-diastolic pressure (EDP) in exercising HFpEF patients implies that the passive viscoelasticity of the heart may reduce exercise performance, but no direct experimental methods can assess this ex-vivo. To determine if the passive viscoelastic properties of the myocardium were capable of influencing EDP in exercise, we have developed a myocardial slice-based protocol that permits long-duration mechanical testing with controllable end-diastolic filling velocity. The role of myocardial viscoelasticity on work output is determined by conducting work-loops at varying speeds of end-diastolic filling. Our results demonstrate an increase in the slope of the end diastolic pressure volume relationship (EDPVR) with filling speed in healthy Wistar-Kyoto rats (WKY) suggesting viscoelasticity can limit myocardial filling ex-vivo. To determine if the viscoelastic contribution was predominantly due to myocytes or extracellular matrix (ECM), the passive mechanical properties of the tissue were assessed before and after decellularization. The results indicate that in WKY rats, the ECM contributes minimally to tissue performance under the experimental working conditions. Together, these results suggest that increased myocardial viscoelasticity may contribute to diastolic dysfunction through myocyte stiffening in the absence of overt fibrosis.

Computational analysis of the ultrasonic effects on resistance spot welding process

Ultrasonic resistance welding (URW) is a hybrid welding process that utilizes in situ ultrasonic vibration during resistance spot welding (RSW) process to increase nugget size, enhance weld mechanical properties, and refine microstructure. Despite the promising experimental results, the underlying mechanisms of acoustic effects on the RSW process are elusive as the involved interacting physical phenomena can hardly be revealed with direct experimental methods. In this study, a three-dimensional fully coupled electro-thermo-mechanical model of the URW process for aluminum alloys has been developed and validated, where the ultrasonic effect on nugget formation and evolution is simulated from different perspectives based on a RSW model. It shows that the enlarged nugget in URW welds is a result of coupling interactions among multiple ultrasonic effects on contact resistance and molten metal thermophysical properties, which are based on the ultrasonically assisted fracture of surface oxides, acoustic softening, cavitation and streaming physical phenomena.

Piezoelectric lattice vibrations in GaN at optical frequencies

At optical frequency range, lattice vibrations in piezoelectric crystal are associated with ionic polarizations. A relationship is formulated, based on classical dispersion theory, involving the dielectric constant (εjj) and the piezoelectric coefficient (djj) of wurtzite GaN. The relation is utilized to investigate the piezoelectric lattice vibrations in GaN at optical frequency, and a close agreement between the computed and the experimental value of djj is found. The study reveals that applications of piezoelectric nature of GaN could be extended to optical frequencies to generate phase coherent acoustic phonons to modulate thermal conduction. At optical frequencies there are no direct experimental methods exist at present for measurement of djj; however, the proposed relation can help to determine djj from infrared reflection measurements.

Rectified phase-matching equation for fiber mode converter gratings using two-mode interference

The resonance wavelength, where a fiber mode converter grating written using periodic external perturbations achieves phase matching, is both a critical design parameter and a device parameter. However, a method to precisely predict the resonance wavelength for any new fiber and grating writing apparatus has been missing so far. The missing link was the lack of direct experimental methods to estimate the modified intermodal phase after writing with external perturbations. The presented method can make this estimation from a single experiment, over a broad wavelength range, based on a novel mathematical connection between two-mode interference and mode conversion. Using the novel methods, experimentally measured resonance wavelengths for different pitch and irradiation conditions have been predicted within relative errors of 4×10-3.

Магнитокалорический эффект и эффект памяти формы в сплаве Гейслера Mn-=SUB=-2-=/SUB=-NiGa

The work presents the investigations of the functional properties of the Heusler alloy Mn2NiGa, made by argon arc melting. The direct experimental methods were used to study: electrical resistance, magnetization, magnetocaloric effect, and shape memory effect in the wide temperature range of 100–400 K. The inverse magnetocaloric effect was found in both the martensitic and austenitic phases, which did not experience saturation in pulsed magnetic field up to 50 T. The values of reversible deformation in the alloy up to 0.35% were obtained with bending mechanical stress up to 247 MPa.

Insights into Proton-Transfer Pathways during Water Oxidation in Photosystem II.

Water oxidation by photosystem II (PSII) involves the release of O2, electrons, and protons at the oxygen-evolving complex (OEC). These processes are facilitated by a hydrogen-bonded network of amino acid residues and waters surrounding the OEC. It is crucial to probe the proton-transfer pathways from the OEC as proton release helps to maintain the charge balance required for efficient water oxidation. In this study, we generate point mutations in the cyanobacterium Synechocystis sp. PCC 6803 at secondary-shell amino acid residues surrounding the OEC: D2-K317, D1-S169, CP43-R357, D1-D61, and D1-N181. We employ direct experimental methods to study the O2 evolution rate under varying pH ranging from 3-8. The pH dependence follows a bell-shaped curve in both wild-type and mutated PSII from which we can derive the effective acidic pKa. The effective acidic pKa provides insights into the protonation states of the amino acid residues participating in the proton-transfer process during the rate-determining step of water oxidation. The presence of an additional effective pKa in D1-S169A PSII and D2-K317A PSII indicates the possibility of multiple proton-transfer pathways during the rate-determining step of water oxidation. We also studied the O2 evolution rate in H2O and D2O with varying pL (L = H or D) to identify the amino acid residues participating in the proton-transfer process. We find that replacing the positively charged lysine with a neutral alanine in D2-K317A PSII and aspartate with alanine in D1-D61A PSII significantly enhances the kinetic solvent isotope effect (KSIE), indicating that proton transfer becomes rate-limiting at the optimal pH in these mutated PSII. However, the KSIE remains unchanged for D1-N181A, D1-S169A, and CP43-R357K PSII. Thus, perturbing the channel defined by the D1-D61 and D2-K317 residues strongly hampers the proton-transfer mechanism, and in turn, the water oxidation reaction of PSII. Hence, our study provides a direct experimental probe to identify that the D1-D61 and D2-K317 residues participate in the proton-transfer process. These results, thereby, provide us a deeper understanding of the proton-transfer processes in the water oxidation mechanism.

Quantification of Mixed Bloch-Néel Topological Spin Textures Stabilized by the Dzyaloshinskii-Moriya Interaction in Co/Pd Multilayers

The three-dimensional structure of nanoscale topological spin textures stabilized by the Dzyaloshinskii-Moriya interaction is governed by the delicate competition between the exchange, demagnetization, and anisotropy energies. The quantification of such spin textures through direct experimental methods is crucial towards understanding the fundamental physics associated with their ordering, as well as their manipulation in spintronic devices. Here, we extend the Lorentz transmission electron microscopy technique to quantify mixed Bloch-Néel chiral spin textures stabilized by the Dzyaloshinskii-Moriya interaction in Co/Pd multilayers. Analysis of the observed intensities under varied imaging conditions coupled to corroborative micromagnetic simulations yields vital parameters that dictate the stability and properties of the complex spin texture, namely, the degree of mixed Bloch-Néel character, the domain wall width, the strength of the Dzyaloshinskii-Moriya interaction, and the exchange stiffness. This approach provides the necessary framework for the application of quantitative Lorentz phase microscopy to a broad array of topological spin systems.

Vesicle-like structure of lipid-based nanoparticles as drug delivery system revealed by molecular dynamics simulations

Lipid-based drug delivery systems are considered as promising vehicles for hydrophobic drug compounds. Lipid distribution within the droplet can affect drug loading capacity in these carriers. However, it is extremely challenging to determine the nanostructure within these carriers through the implementation of the direct experimental methods due to the ultrafine size. Therefore, coarse grained molecular dynamics (MD) simulation was utilized to model different kinds of lipid-based nanoparticles of the diameter about 12 nm including solid lipid nanoparticles (SLN), nanoemulsion (NE), and nanostructured lipid carriers (NLC), and the organization of the lipids within the carriers was explored. The aforementioned nanoparticles consisted of stearic acid, oleic acid as lipids, and sodium dodecyl sulfate (SDS) as a surfactant in water medium. Furthermore, the impact of solid to liquid mass ratio on the lipid distribution within the lipid matrix was investigated regarding the NLC simulations. In the equilibrium state, we observed the vesicle-like structure for all the investigated systems in which the hydrophilic moieties of the lipids and surfactant organized a semi-bilayer fold into the droplet and the hydrophobic tails accumulated among them. It is worth mentioning although SDS as a harsh surfactant, which is a special case, was expected to be present in the surface of the droplet, it penetrated into the lipids. Additionally, our results showed remarkable entrapped water beads inside the droplet in the form of one or more cavities along the internal layer of the head groups which was surrounded by lipid head groups. It was also reported that in the building structure of the nanoemulsion and SLN, in the central parts of the droplets, lipids were denser than the case of NLCs. Moreover, no crystallization occurred within the lipid-based carriers. Finally, the results indicated that, in the case of NLC simulations, the lipid distribution within the lipid matrix was insensitive to the mass fraction of solid to liquid lipids.

Heterogeneous grain-scale response in ferroic polycrystals under electric field.

Understanding coupling of ferroic properties over grain boundaries and within clusters of grains in polycrystalline materials is hindered due to a lack of direct experimental methods to probe the behaviour of individual grains in the bulk of a material. Here, a variant of three-dimensional X-ray diffraction (3D-XRD) is used to resolve the non-180° ferroelectric domain switching strain components of 191 grains from the bulk of a polycrystalline electro-ceramic that has undergone an electric-field-induced phase transformation. It is found that while the orientation of a given grain relative to the field direction has a significant influence on the phase and resultant domain texture, there are large deviations from the average behaviour at the grain scale. It is suggested that these deviations arise from local strain and electric field neighbourhoods being highly heterogeneous within the bulk polycrystal. Additionally, the minimisation of electrostatic potentials at the grain boundaries due to interacting ferroelectric domains must also be considered. It is found that the local grain-scale deviations average out over approximately 10–20 grains. These results provide unique insight into the grain-scale interactions of ferroic materials and will be of value for future efforts to comprehensively model these and related materials at that length-scale.

Assessing strain mapping by electron backscatter diffraction and confocal Raman microscopy using wedge-indented Si

The accuracy of electron backscatter diffraction (EBSD) and confocal Raman microscopy (CRM) for small-scale strain mapping are assessed using the multi-axial strain field surrounding a wedge indentation in Si as a test vehicle. The strain field is modeled using finite element analysis (FEA) that is adapted to the near-indentation surface profile measured by atomic force microscopy (AFM). The assessment consists of (1) direct experimental comparisons of strain and deformation and (2) comparisons in which the modeled strain field is used as an intermediate step. Direct experimental methods (1) consist of comparisons of surface elevation and gradient measured by AFM and EBSD and of Raman shifts measured and predicted by CRM and EBSD, respectively. Comparisons that utilize the combined FEA–AFM model (2) consist of predictions of distortion, strain, and rotation for comparison with EBSD measurements and predictions of Raman shift for comparison with CRM measurements. For both EBSD and CRM, convolution of measurements in depth-varying strain fields is considered. The interconnected comparisons suggest that EBSD was able to provide an accurate assessment of the wedge indentation deformation field to within the precision of the measurements, approximately 2×10−4 in strain. CRM was similarly precise, but was limited in accuracy to several times this value.

Discussions on Particle Flux Measurement in Gas-Solids Risers

Abstract In gas-solids risers of fast fluidization regime, the gross particle flux determined by integrating the product of the measured average particle concentration and velocity is always found several times or even larger than that measured by direct experimental methods. Based on analysis of the measurement mechanisms and a simple model for two-phase flow structure in gas-solids risers, this big unidirectional deviation is first explained in depth in this study. It is concluded that the unique two-phase flow structure (i.e. the low-velocity dense phase and high-velocity dilute phase in a gas-solids riser) and the bad coupling quality of the measured transient particle concentration and velocity during data processing lead to this big unidirectional deviation. Finally, this explanation is extended to wider multiphase flow systems and advices are proposed in measuring phase fluxes.

Color-shape associations revealed with implicit association tests.

Kandinsky proposed a correspondence theory that suggests associations between specific colors and shapes (i.e., circle-blue, square-red, triangle-yellow). Makin and Wuerger tested the theory using the Implicit Association Test (IAT) and did not find clear evidence for Kandinsky’s color-shape associations among British participants. In the present study, we first replicated the previous study among Japanese participants and found similar results to those of Makin and Wuerger, showing little support for Kandinsky’s theory. In the subsequent experiment, we tested another set of color-shape associations that had been revealed by using an explicit matching method (circle-red, square-blue, triangle-yellow) in Japanese participants. The IAT tests showed that response times were significantly faster when circle-red, square-blue, and triangle-yellow combinations were mapped onto the same response key, rather than different key combinations, indicating that these color-shape combinations were encoded. These results provide the first empirical evidence that color-shape associations can be measured by indirect behavioral methods, and in particular, Japanese people’s color-shape associations (circle-red, square-blue, triangle-yellow) can be observed by both direct and indirect experimental methods.

Review: critical appraisal of methods to investigate the effect of temperature on grapevine berry composition

The grapevine is an economically important crop and a model species of long-lived perennials widely used in bioclimatic studies. Ambient temperature modulates berry composition, hence the significant research effort in establishing links between temperature, berry composition and wine attributes. Our current understanding of the effect of temperature on berries and wines has been largely gained from indirect methods or direct methods in controlled conditions. Indirect methods include comparisons of thermally contrasting locations and vintages; this approach is of value but is bound to be inconclusive as the effect of temperature is often confounded with other weather and climate factors (solar radiation, vapour pressure deficit and rainfall), management practices and soils. Direct experimental methods comparing fruit grown at a range of temperature are required to prove cause-and-effect, but attempts to modify the thermal regime of the plant often generate secondary effects. Experimental artefacts in controlled environments often include small soil volume, lack of wind and altered radiation regimes, with direct implications for plant physiology and berry composition. Experiments involving controlled temperature in vineyards aim at a higher degree of realism, but are constrained by cost, issues of scale in space and time, and are not necessarily free from artefacts. Indirect and direct methods are of course non-mutually exclusive but complementary. This review critically assesses the methods used to elucidate the effect of temperature on grape berry composition. It emphasises the limitations of studies where confounded effects are overlooked. With the focus on selected berry traits (total soluble solids, total and titratable acidity and anthocyanins), we analyse the dominant effect of temperature and highlight discrepancies and agreements between indirect and direct research methods.

Simultaneous extraction of charge density dependent mobility and variable contact resistance from thin film transistors

A model for the extraction of the charge density dependent mobility and variable contact resistance in thin film transistors is proposed by performing a full derivation of the current-voltage characteristics both in the linear and saturation regime of operation. The calculated values are validated against the ones obtained from direct experimental methods. This approach allows unambiguous determination of gate voltage dependent contact and channel resistance from the analysis of a single device. It solves the inconsistencies in the commonly accepted mobility extraction methods and provides additional possibilities for the analysis of the injection and transport processes in semiconducting materials.

Performance-based assessment of durability and prediction of RC structure service life: transport properties as input data for physical models

This paper deals with an approach based on durability indicators (DIs), intended for the assessment of the durability and the prediction of the service life (SL) of reinforced concrete structures with respect to reinforcement corrosion. The methods of assessment of the DIs, more specifically of the transport properties effective chloride diffusion coefficient and “intrinsic” liquid water permeability, are first investigated. Direct experimental methods, indirect methods based on simple analytical formulas, as well as numerical inverse analysis which involves the same physical models as used for prediction, are compared. Very good agreement is pointed out between the results obtained by the various methods for a broad range of materials. The effect of SCM, as well as of accelerated carbonation in the case of permeability, is also investigated. 1-D numerical models of moisture or ionic isothermal transport are then introduced, where the selected DIs are the main input data. Simulations carried out with the moisture transport model are compared to moisture profiles measured by gamma-ray attenuation, in order to validate the model and the input data (permeability). With regard to chloride ingress, examples of application of the multispecies transport model (saturated conditions) are provided for concentration profile prediction, in lab and in field conditions, as well as SL prediction.

An hourly based performance comparison of an integrated micro-structural perforated shading screen with standard shading systems

This article evaluates the performance of an integrated micro structural perforated shading screen (MSPSS). Such a system maintains a visual connection with the outdoors while imitating the shading functionality of a venetian blind. Building energy consumption is strongly influenced by the solar gains and heat transfer through the transparent parts of the fenestration systems. MSPSS is angular-dependent shading device that provides an effective strategy in the control of daylight, solar gains and overheating through windows. The study focuses on using direct experimental methods to determine bi-directional transmittance properties of shading systems that are not included as standard shading options in readily available building performance simulation tools. The impact on the indoor environment, particularly temperature and daylight were investigated and compared to three other static complex fenestration systems. The bi-directional description of the systems was used throughout the article. The simulations were validated against outdoor measurements of solar and light transmittance.

Particle Mass from Planck-Scale Fluctuations

In this article we present a theory of particle mass formation. The theory is conceptually based on the ideas that space time fluctuations of very high Planck-scale energy form mass if they exceed a certain threshold value that is a characteristic of the universe. The fluctuations at the length scales that are orders of magnitude smaller than what is currently accessible by direct or indirect experimental methods and of a quantum phenomenonological nature, much inference has to be made of the Planck length scale dynamics that form the observed created particles and their mechanics. Therefore a minimalistic theory should be the starting point, and it is what is proposed here in this rapid communication. Fluctuations of coupled space and time occur, are described statistically and in phase space and therefore are as conjugate variables related by an uncertainty principle the relativistic analogue of the Heisenberg uncertainty principle familiar in low energy quantum mechanics. An information-entropy argument is made for the derivation of the statistical distributions of the fluctuations, that are parametrized by the inverse temperature in order to conveniently connect to thermodynamics. In analogy with 3D 1p time or thermodynamical parameterized condensed matter Schroedinger - like quantum mechanical systems where fluctuations of the system obtain self-energy additional terms to the dispersion relation that describe stable and metastable excitations with mass - like or effective mass, the resulting minimally coupled 4D 1p or 4D-1p equations describing the observed worm-hole mouths obtain self-energy terms to the dispersion relation that derive massive Klein-Gordon - like equations.