Standard Method For Determination Research Articles

Multiscale poromechanics of wet cement paste

Capillary effects, such as imbibition drying cycles, impact the mechanics of granular systems over time. A multiscale poromechanics framework was applied to cement paste, which is the most common building material, experiencing broad humidity variations over the lifetime of infrastructure. First, the liquid density distribution at intermediate to high relative humidity is obtained using a lattice gas density functional method together with a realistic nanogranular model of cement hydrates. The calculated adsorption/desorption isotherms and pore size distributions are discussed and compare well with nitrogen and water experiments. The standard method for pore size distribution determination from desorption data is evaluated. Second, the integration of the Korteweg liquid stress field around each cement hydrate particle provided the capillary forces at the nanoscale. The cement mesoscale structure was relaxed under the action of the capillary forces. Local irreversible deformations of the cement nanograins assembly were identified due to liquid-solid interactions. The spatial correlations of the nonaffine displacements extend to a few tens of nanometers. Third, the Love-Weber method provided the homogenized liquid stress at the micrometer scale. The homogenization length coincided with the spatial correlation length of nonaffine displacements. Our results on the solid response to capillary stress field suggest that the micrometer-scale texture is not affected by mild drying, while nanoscale irreversible deformations still occur. These results pave the way for understanding capillary phenomena-induced stresses in heterogeneous porous media ranging from construction materials to hydrogels and living systems.

Colorimetric microdilution assay: Validation of a standard method for determination of MIC, IC50%, and IC90% of antimicrobial compounds

The emergence of multiresistant bacteria directly impacts on the search for new compounds with antimicrobial activity, and it is important the improvement of new techniques are able to determine the minimum inhibitory concentration (MIC) of antimicrobial compounds. The microdilution technique is widely used for saving culture media, reagents and compounds to be tested. However, the literature does not describe a colorimetric method capable of correlating absorbance with concentration of viable microorganisms (CFU mL−1). Therefore, the novelty of this work was the standardization and validation of a colorimetric and quantitative method capable of determining the MIC of several compounds with antimicrobial activity and the conversion of absorbance values to CFU mL−1. The conditions carried out for the method were: the use of 0.125% (w/v) 2,3,5-triphenyltetrazolium chloride (TTC) solution added after 22 h of incubation at 35 °C, followed by 2 more hours of incubation and subsequent reading in a spectrophotometer. The tested microorganisms were: Staphylococcus aureus (ATCC 6538), Escherichia coli (ATCC 8739), Pseudomonas aeruginosa (ATCC 9027) and Candida albicans (ATCC 10231). The method was validated and showed linearity (R2 > 0.95), precision (RSD <26%), accuracy (75% to 122%) and robustness (p > 0.05). The validated parameters ensured the harmonization of methodology to determine not only MIC as well as inhibitory concentrations of 50% (IC50%) and 90% (IC90%) of the antimicrobial compounds.

Real-time monitoring and control of nitride growth rates by Metal Modulated Epitaxy

The standard method for growth rate determination in semiconductor thin films, by Molecular Beam Epitaxy (MBE), is through RHEED intensity oscillations prior to device layer epitaxy. High quality III-Nitride epitaxy occurs with metal-rich surfaces and under step-flow growth conditions, which do not produce RHEED oscillations. This article demonstrates the capability to monitor the growth rate of gallium nitride (GaN), at any point during film growth with high fidelity, under step-flow growth conditions. RHEED intensity vs. time measurements determine the growth rate by Metal Modulated Epitaxy (MME). Utilizing differential analysis, a factor of 2x improvement in accuracy is demonstrated, with a Standard Error less than 4%. Complementary analysis with X-Ray Diffraction and RHEED identify the Ga bilayer thickness as 2.34 ML ± 0.08 ML, representing the first time RHEED analysis has been used to characterize the thickness of the Ga bilayer on GaN.

Evolution from Cooling Modeling to Cooling Engineering of the Steel Quenching Process: A Technology Overview

Abstract The type of heat treatment process used is mainly determined by its cooling mode. Hardening is a metal heat treatment during which the most critical operation is cooling. Most quenchants used for steel hardening are vaporizable liquids, such as water, petroleum oils, emulsions, aqueous polymer solutions, or brines. Testing methodologies that include ISO 9950, Industrial Quenching Oils-determination of Cooling Characteristics-Nickel-alloy Probe Test Method, and ASTM Standards: D6200, Standard Test Method for Determination of Cooling Characteristics of Quench Oils by Cooling Curve Analysis, D6482, Standard Test Method for Determination of Cooling Characteristics of Aqueous Polymer Quenchants by Cooling Curve Analysis with Agitation (Tensi Method), D6549, Standard Test Method for Determination of Cooling Characteristics of Quenchants by Cooling Curve Analysis with Agitation (Drayton Unit), and D7646, Standard Test Method for Determination of Cooling Characteristics of Aqueous Polymer Quenchants for Aluminum Alloys by Cooling Curve Analysis, are typically used to evaluate the cooling characteristics of these quenchants or processes. The cooling time–temperature curves obtained by these methodologies traditionally involve three stages of cooling. However, the relationship between this model and heat treatment, especially between hardening theory and practice, has not been satisfactory. Therefore, it is necessary to better understand the relationship between cooling theory and metallurgical behavior to create a new cooling model that achieves zero distortion, zero dispersion of quality, and zero pollution, which are concepts proposed in the “Heat Treating Industry Vision 2020 “and the “Heat Treating Technology Roadmap 2004” by the ASM Heat Treating Society and Materials Treating Institute. The relationship between the physical metallurgical phenomenon of phase transformation of a steel workpiece during quenching after being austenitized and the actual cooling conditions in engineering practice were analyzed and discussed in this report. Additionally, the development of advanced cooling technologies and related quenching equipment are discussed. The evolution from cooling model research to cooling engineering construction represents important progress in heat treatment practice.

Preparation of Lignin Nanoparticles from Wood Waste for Wood Surface Treatment.

Lignin was isolated from wood wastes comprising Iroko sawdust (IR) and mixed sawdust from Iroko and Norway spruce (IRNS), furnished by a local wood houses producer. The respective acidolysis lignin fractions were structurally characterized using pyrolysis (Py)-GCMS, two-dimensional heteronuclear single quantum correlation nuclear magnetic resonance (2D HSQC NMR), Fourier-transform infrared FTIR and ultraviolet-visible (UV-VIS) spectroscopies, size exclusion chromatography, and standard wet-chemistry methods for Klason lignin and polysaccharides determination. The isolated lignin fractions were subsequently used for the preparation of lignin nanoparticles (LNPs) using a non-solvent method. LNPs were then used for wood surface treatment using a dip-coating technique. The coated wood samples were analyzed by colorimetry and scanning electron microscopy (SEM) before and after artificial weathering experiments in a UV chamber to investigate the UV protection potential of the LNPs coatings. Wood samples dip-coated with LNPs showed promising surface modifications resembling a sort of film of fused LNPs. Coatings made from IR-LNPs and IRNS-LNPs performed significantly better in artificial weathering experiments than uncoated reference samples.

Determinação de Glicerina Livre em Biodiesel Utilizando Espectroscopia UV Visível: Estudo de Validação do Método

High glycerol content in biodiesel impairs engine performance. Brazilian legislation, (ANP Resolution 42/2004), limits the maximum of 0.02% w/w for free glycerol in biodiesel. The ASTM D6584 standard method for glycerol determination is gas chromatography, a time consuming and expensive technique. As alternative, free glycerol in biodiesel can be determined, after derivatization, by absorption spectroscopy in the visible region (410 nm). In this work, we have used a validation protocol for the spectroscopy method. Results indicate that the proposed method is linear (r2 = 0.993) for the studied concentration range and has acceptable accuracy and precision. The method presented relative standard deviations values of intermediate repeatability and accuracy below 5.0%. To calculate the limits of detection and quantification, three different calculation methods were used. Two of them resulted in appropriate quantification limits for glycerol. However, for the INMETRO calculation method, we found a higher value of quantification limit. Considering that the method is based on a chemical derivatization reaction, to produce a color product, the robustness of the method was analyzed for small changes in reaction temperature, wavelength and type of cuvette used in measurements. The results have shown that the method is robust for small variations in the reaction temperature, but not for small changes in wavelength and type of cuvette used (glass or plastic cuvette).

Zmiinyi Island Coastal Zone Macrozoobenthos State in 2016-2017

Purpose. To study the state of macrozoobenthos in the Zmiinyi Island coastal zone in 2016-2017. Methods. Standard methods of macrozoobenthos sampling, determination, number and biomass estimation. Results. Results of analysis of biodiversity, structural characteristics and taxonomic composition of macrozoobenthos in the Zmiinyi Island coastal zone have been presented. Seasonal dynamics of its number and biomass has been studied. Assessment of marine environment quality has been performed based on the metrics of macrozoobenthos. Conclusions. Altogether, 132 taxa of benthic invertebrates belonging to 10 biggest taxonomic groups of macrozoobenthos have been identified in the Zmiinyi Island coastal zone in 2016-2017. Analysis of taxonomic composition identified 1 species of Porifera (0.8%), 7 taxa of Cnidaria (5.3%), 3 taxa of Platyhelminthes (2.3%), 1 taxon of Nemertea (0.8%), 3 taxa of Bryzoa (2.3%), 52 taxa of Annelida (39.4%), 25 taxa of Mollusca (18.9%), 35 taxa of Arthropoda (265%), 2 taxa of Echinodermata (1.4%) and 3 taxa of Chordata (2.3%). Out of 132 macrozoobenthos taxa 6 are enlisted in the Red Data Book of Ukraine and 8 – in the Black Sea Red Data Book. Macrozoobenthos number varied from 0.317х104 (27.11.2016) to 16.943х104 (19.08.2016) ind/m2 on soft substrate and from 2.683х104 (17.05.2016) to 30.725х104 (19.08.2016) ind/m2 on rocky substrate; biomass varied from 0.017 (17.05.2017) to 34.857 (19.08.2016) kg/m2 on soft substrate and from 1.531 (27.11.2016) to 46.147 (19.08.2016) kg/m2 on rocky substrate. Maximal development of benthos was registered in summer period. Quality of marine environment on the AMBI and M-AMBI indices was assessed as Good in 21 cases out of 23 and as Moderate in 2 cases 2 out of 23. Mean values of AMBI and M-AMBI indices for different seasons made respectively: May, 2016 – 2.56 and 0.59; August, 2016 – 1.86 and 0.69; November, 2016 – 1.70 and 0.71; June, 2017 – 1.87 and 0.75.

Studies of mezozooplankton in the Zmiinyi Island coastal waters in 2016-2017

Purpose. To study the state of mezozooplankton in the Zmiinyi Island coastal waters in 2016-2017. Methods. Standard methods of mezozooplankton sampling, determination, number and biomass assessment. Results. Based on the data received, analysis of biodiversity and structural characteristics of mezozooplankton in the Zmiinyi Island coastal waters has been made. Taxonomic composition, number and biomass have been determined for each species; dynamics of number and biomass presented season by season. Marine environment quality assessment has been performed on the metrics of mezozooplankton. Conclusions. Altogether 32 taxa of 9 main mezozooplankton groups were identified in 2016-2017. It was shown that the dominating groups were Copepoda, Rotatoria, Protozoa, Cladocera and Harpacticoida. Shannon’s biodiversity index of mezozooplankton varied from 0.41 (20.06.2016) to 3.29 (24.07.2016) with average values 2.32 in 2016 and 1.64 in 2017. Mezozooplankton number and biomass varied in 2016-2017 within broad limits from 645 to 55829 ind/m³ and 1.385 to 2597.248 mg/m³ respectively (with average values 10129 ind/m³ and 154.82 mg/m³ in the period IV-XII, 2016 and 21563 ind/m³ and 466.30 mg/m³ in the period IV-VI, 2017). Water quality in the coastal waters of the Zmiinyi Island on the state of mezozooplankton was «Bad» in 18 cases out of 68 (26.4%) and was assessed in general as «Poor». On total mezozooplankton biomass the state was assessed as «Poor» and «Bad» (68.2%). «Good» (10.6%) and «High» (9.1%) quality was found in 19.7% of cases, which evidenced unsatisfactory state of mezozooplankton – the main component of food reserve for pelagic larvae and pelagic species of the Black Sea fish.

The Effect of Diffusion on the Sedimentation Rate of Soil Microparticles

The submitted paper presents the results of the experiment aimed at quantifying the effect of diffusion on the sedimentation rate of soil microparticles of different fractions. The goal of the experiment was to specify the determination of the texture composition of soils. The textural composition of the soil gives basic information about its hydrophysical properties. Standard methods for determination of granulometric soil composition are based on sedimentation methods. Measuring errors occur in the measurement of the soil microparticle rate, which are usually made of clay particles. Their source is the effect of diffusion. In the settling process with the gradual formation of the colloidal dispersion system, the deposition rate decreases. The rate of sedimentation of the dispersion particles approaches the rate of the mean diffusion feed in the opposite direction. Gradually, the state of dynamic sedimentation equilibrium occurs. The dispersion ratio was in dispersed system formed by clay soil particles from the Senne site. The dispersed medium was distilled water. Grain analyzes were performed by a laser diffraction method on a Mastersizer 2000 from MALVERN Instruments. The soil microparticles’ rates were measured on the basis of the time and the path of particles with diameter d (90). The output of the experiment is the diffusion coefficient, diffusion average feed and sedimentation rate for soil particles of different sizes. The results of the work show that with size of sedimented soil particles, the effect of diffusion increased. On this basis, it is possible to verify the lower limit of the results of grain size analyzes based on the sedimentation method. The results of the work show that the reduction of the size of the settled soil particles increases the effect of diffusion. On this basis, it is possible to quantify the lower limit of the results of grain size analyzes based on the sedimentation method and the particle size at which dynamic sedimentation equilibrium occurs.

Suspension- and powder-based derivation of Hansen dispersibility parameters for zinc oxide quantum dots

For most particle-based applications, formulation in the liquid phase is a decisive step, and thus, particle interactions and stability in liquid media are of major importance. The concept of Hansen solubility parameters (HSP) was initially invented to describe the interactions of (polymer) molecules and their solubility in different liquids and is increasingly being used in particle technology to describe dispersibility. Because dispersions are not thermodynamically stable, the term Hansen dispersibility parameters (HDP) is used instead of HSP (Süß, Sobisch, Peukert, Lerche, & Segets, 2018). Herein, we extend a previously developed standardized and non-subjective method for determination of Hansen parameters based on analytical centrifugation to the important class of quantum materials. As a technically relevant model system, zinc oxide quantum dots (QDs) were used to transfer our methodology to nanoparticles (NPs) with sizes below 10nm. The results obtained using the standard procedure starting from a dried powder were compared with those obtained through redispersion from the wet sediment produced during the typical washing procedure of QDs, and drying was observed to play an important role. In conclusion, our study reveals the high potential of HDP for quantifying the interfacial properties of NPs as well as their link to dispersibility.

Characterization of Damping Properties in 3D Printed Structures

Current research on the effectiveness of a subordinate oscillator array (SOA) as a broadband mechanical filter relies on adequate knowledge of the SOAs material properties. Recent studies have shown a high sensitivity of these structures to disorder. A desire to produce large numbers of arrays to test this sensitivity to disorder motivated a transition from metal to 3-dimensional printed plastic SOAs. Irregularities associated with the curing process of the 3D printed polymers, as well as a general inconsistency of material properties of plastics, in turn highlighted the need for characterization of properties of 3D printed materials, especially those properties related to damping. As part of this study, several 3D printed plastic cantilevers, varying in material, printing technique, and printing orientation, are measured. Quantities of interest include the Young’s modulus and density, as well as phenomenological properties, like the quality factor of specific designs. An ASTM standard test method for property determination is implemented with a laser Doppler vibrometer (LDV) to test each polymer. In addition to the ASTM protocol, tests are conducted in vacuum to distinguish internal damping mechanisms of the cantilever from external fluid mechanisms. Results are compared to both analytic and numeric predictions and published theory.

Quando a HbA1c não é suficiente: um caso de Hemoglobina de Baltimore

A hemoglobina A1c (HbA1c) é o gold standard para monitorização da diabetes mellitus. A HbA1c pode estar falsamente diminuída ou aumentada em algumas situações clínicas, como hemoglobinopatias, não traduzindo adequadamente o controle glicêmico. Apresenta-se aqui o caso de um doente com valor de HbA1c incompatível com os registros de glicemia capilar, devido à presença de hemoglobina N-Baltimore. O caso apresentando é relevante porque, apesar de assintomática, a presença desta hemoglobinopatia conduz a uma diabetes falsamente encarada como controlada, se utilizados os métodos de determinação de HbA1c habituais.

Instrumentation for Vibrational Circular Dichroism Spectroscopy: Method Comparison and Newer Developments.

Vibrational circular dichroism (VCD) is a widely used standard method for determination of absolute stereochemistry, and somewhat less so for biomolecule characterization and following dynamic processes. Over the last few decades, different VCD instrument designs have developed for various purposes, and reliable commercial instrumentation is now available. This review will briefly survey historical and currently used instrument designs and describe some aspects of more recently reported developments. An important factor in applying VCD to conformational studies is theoretical modeling of spectra for various structures, techniques for which are briefly surveyed.

Mass Transfer in Multiphasic Gas/Liquid/Liquid Systems. KLa Determination Using the Effectiveness-Number of Transfer Unit Method

The Effectiveness-Number of Transfer Unit method (ε-NTU method) was applied to determine the overall mass transfer coefficient, KLa, of operating gas-liquid absorbers treating Volatile Organic Compounds (VOCs). This method requires the knowledge of the operating conditions (gas flow rate, QG; liquid flow rate, QL; scrubber volume V), the measurement of gaseous concentrations at the inlet, CGin, and at the outlet, CGout, of the contactor (in order to determine the effectiveness of the absorber ε) and the calculation of the Henry coefficient of the VOC between the gas and the liquid phases (HVOC). Coupled with the “equivalent absorption capacity” concept, the ε-NTU method was used to determine KLa of absorbers contacting a gas and a mixture of water and a Non Aqueous Phase, successfully. The method, validated from literature data for configurations countercurrent scrubbers and stirred tank reactors, could be used to simply determine the overall mass transfer coefficient of systems for which the standard KLa determination methods still remain non-reliable or inaccurate (viscous solvents, mixture of immiscible liquids, fermentation broths…).

Pharmacokinetics and Bioavailability Study of Monocrotaline in Mouse Blood by Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry.

Background and Aims The present study aimed to develop a simple and sensitive method for quantitative determination of monocrotaline (MCT) in mouse blood employing ultra-performance liquid chromatography-electrospray ionization tandem mass spectrometry (UPLC-ESI/MS/MS) using rhynchophylline as an internal standard. Methods Proteins present in the blood samples were precipitated using acetonitrile. MCT was separated using a 1.7-μm ethylene bridged hybrid (BEH) C18 column (2.1 mm × 50 mm) with a gradient elution program and a constant flow rate of 0.4 mL/min. The LC mobile phase consisted of 10 mmol/L ammonium acetate (containing 0.1% formic acid) and acetonitrile. The total elution time was 4.0 min. The analytes were detected on a UPLC-ESI mass spectrometer in multiple reaction monitoring (MRM) mode and quantified. Results The new method for the determination of MCT has a satisfactory linear detection range of 1-2000 ng/mL and excellent linearity (r = 0.9971). The lower limit of quantification (LLOQ) of MCT is 1.0 ng/mL. Intra- and interassay precisions of MCT were ≤13% with an accuracy from 96.2% to 106.6%. The average recovery of the new method was >75.0%, and matrix effects were between 89.0% and 94.3%. Based on the pharmacokinetics data, the bioavailability of MCT in mice was 88.3% after oral administration. Conclusions The results suggest that the newly standardized method for quantitative determination of MCT in whole blood is fast, reliable, specific, sensitive, and suitable for pharmacokinetic studies of MCT after intravenous or intragastric administration.

Digital camera-based lipase biosensor for the determination of paraoxon

This work is focused on construction of a biosensor containing unique bacterial homogenate with high lipase activity and colorimetric type of assay where camera of a smartphone was chosen as a detector. The biosensor was constructed as a tool of lipase inhibitors and paraoxon served as a representative analyte inhibiting the lipase.Psychrophilic strains of bacteria isolated from in Antarctica were tested and the best isolate P4368 having huge lipase activity was chosen. Tween assay was performed as a standard method for lipase activity determination and indoxylacetate served as a substrate of lipase measurable by smartphone camera and R, G and B color channels digital analysis. Bacteria were homogenized and immobilized on polyvinylidene difluoride membrane and indoxylacetate was immobilized in the proximity of the homogenate. Paraoxon ethyl was analyzed by the standard method and by the camera-based biosensor.The biosensor-based assay was found to determine paraoxon with limit of detection 3.72 × 10−8 mol/l and IC50 value for paraoxon was 4.00 × 10-6 mol/l. A volume 5 μl of sample was sufficient for the assay and the sample was applied directly without any processing.In a conclusion, a simple colorimetric biosensor for the determination of venomous compounds like organophosphorus pesticides and nerve agents was constructed and promising analytical parameters were received during its characterization.

SCHEMES OF SOLID-PHASE SPECTROPHOTOMETRIC ANALYSIS OF FOOD OBJECTS

The aim of research is development of approaches to the development of schemes for microelement analysis of food objects. This will make it possible to monitor food quality by simple and affordable methods in factory laboratories. Based on data on the immobilization of dyes on ion exchangers and on the interaction of metal ions or their complexes with immobilized dyes, solid-phase spectrophotometric (SPS) and photometric methods for determining metal ions in food technology, biotechnology and the environment have been developed. Techniques are sensitive. High distribution coefficients (D³104 cm3/g) of metal ions help to reduce the detection limit when using immobilized dye as compared to the reaction in solution. Based on the detection limit values (DLV), the proposed sorption-spectrophotometric methods for determining metal ions are second only to the atomic absorption (AAS) determination of Cd (II) and Hg (II) ions and the polarographic determination of Cd (II) ions. However, the proposed methods for the determination of these metal ions are sufficient for the determination of Cd (II) and Hg (II) ions in food products at the MPC level. In the case of determination of Pb (II), Zn (II), Cu (II), Fe (III) ions, the developed methods have advantages over standard methods for determination of metal ions in food products, since they make it possible to determine these ions at a level ≤0.1…0.5 MPC; Ion exchangers with immobilized dyes and solid-phase spectrophotometric determination methods with their participation are environmentally safe, since they do not require the use of toxic organic reagents; are simple in execution and economically advantageous because of the low cost of used materials and reagents. The correctness of the results of the determination by the developed methods is proved: by comparison with the results of determinations on standard methods at various analysis objects using the method of additives, standard samples. The relative standard deviation of the developed SPS determination procedures does not exceed 0.10, which indicates satisfactory reproducibility of the results. The developed methods exceed the majority of standard and best analogs, known from the literature, for sensitivity and selectivity. The used methods of analysis are characterized by the simplicity of the experiment, ecological safety, do not require special expensive equipment, highly qualified personnel and a stationary laboratory.

Comparison of two methods for determination of intestinal villus to crypt ratios and documentation of early age-associated ratio changes in broiler chickens , ,

The determination of intestinal villus to crypt ratios (VCR) is a common method utilized to evaluate effects of various diet regimens on gut microanatomy and for the histologic quantification of intestinal responses to disease processes. Two methods for the determination of small intestinal VCR were compared in early age chickens. A standard method for VCR determination based on 10 villus and crypt length measurements in the jejunal region of the small intestine was employed for the calculation of villus to crypt length ratio (VCLR). That method was compared to a new approach based on a single histomorphometric determination of the crypt and total mucosal areas using image analysis software. Subtraction of the crypt area from the total area provided the villus area and allowed for the subsequent calculation of villus to crypt area ratio (VCAR). At 4 and 18 h posthatch, VCLR was higher than that of VCAR, but there was no significant difference between VCLR and VCAR at 0 h (hatch) and at 168 h (d 7) posthatch. Nevertheless, the pattern of age-associated changes for VCLR and VCAR were comparable throughout the early posthatch period. Furthermore, the new method used in determining VCAR is subject to less human error, allows for an appreciable reduction in the number of measurements required, and facilitates a larger intestinal segment evaluation. Standard linear measurements require the selection of variable numbers of villi and crypts, whereas the area method only requires selection of a single region that incorporates numerous villi and crypts of variable sizes in providing a less subjective approach. This is particularly advantageous in studies on intestinal disease conditions resulting in marked multifocal variation in villus stature. This study further documented age-associated changes occurring in the VCR of the small intestine during the early posthatch period. Across the 2 methods used for VCR determination, a major and highly significant reduction in the VCR was observed to occur between 18 h and 168 h posthatch.

Prediction of Chlorophyll Content in Different Light Areas of Apple Tree Canopies based on the Color Characteristics of 3D Reconstruction

Improving the speed and accuracy of chlorophyll (Ch1) content prediction in different light areas of apple trees is a central priority for understanding the growth response to light intensity and in turn increasing the primary production of apples. In vitro assessment by wet chemical extraction is the standard method for leaf chlorophyll determination. This measurement is expensive, laborious, and time-consuming. Over the years, alternative methods—both rapid and nondestructive—were explored, and many vegetation indices (VIs) were developed to retrieve Ch1 content at the canopy level from meter- to decameter-scale reflectance observations, which have lower accuracy due to the possible confounding influence of the canopy structure. Thus, the spatially continuous distribution of Ch1 content in different light areas within an apple tree canopy remains unresolved. Therefore, the objective of this study is to develop methods for Ch1 content estimation in areas of different light intensity by using 3D models with color characteristics acquired by a 3D laser scanner with centimeter spatial resolution. Firstly, to research relative light intensity (RLI), canopies were scanned with a FARO Focus3D 120 laser scanner on a calm day without strong light intensity and then divided into 180 cube units for each canopy according to actual division methods in three-dimensional spaces based on distance information. Meanwhile, four different types of RLI were defined as 0–30%, 30–60%, 60–85%, and 85–100%, respectively, according to the actual division method for tree canopies. Secondly, Ch1 content in the 180 cubic units of each apple tree was measured by a leaf chlorophyll meter (soil and plant analyzer development, SPAD). Then, color characteristics were extracted from each cubic area of the 3D model and calculated by two color variables, which could be regarded as effective indicators of Ch1 content in field crop areas. Finally, to address the complexity and fuzziness of relationships between the color characteristics and Ch1 content of apple tree canopies (which could not be expressed by an accurate mathematical model), a three-layer artificial neural network (ANN) was constructed as a predictive model to find Ch1 content in different light areas in apple tree canopies. The results indicated that the mean highest and mean lowest value of Ch1 content distributed in 60–85% and 0–30% of RLI areas, respectively, and that there was no significant difference between adjacent RLI areas. Additionally, color characteristics changed regularly as the RLI rose within canopies. Moreover, the prediction of Ch1 content was strongly correlated with those of actual measurements (R = 0.9755) by the SPAD leaf chlorophyll meter. In summary, the color characteristics in 3D apple tree canopies combined with ANN technology could be used as a potential rapid technique for predicting Ch1 content in different areas of light in apple tree canopies.

Towards 3D crystal orientation reconstruction using automated crystal orientation mapping transmission electron microscopy (ACOM-TEM).

To relate the internal structure of a volume (crystallite and phase boundaries) to properties (electrical, magnetic, mechanical, thermal), a full 3D reconstruction in combination with in situ testing is desirable. In situ testing allows the crystallographic changes in a material to be followed by tracking and comparing the individual crystals and phases. Standard transmission electron microscopy (TEM) delivers a projection image through the 3D volume of an electron-transparent TEM sample lamella. Only with the help of a dedicated TEM tomography sample holder is an accurate 3D reconstruction of the TEM lamella currently possible. 2D crystal orientation mapping has become a standard method for crystal orientation and phase determination while 3D crystal orientation mapping have been reported only a few times. The combination of in situ testing with 3D crystal orientation mapping remains a challenge in terms of stability and accuracy. Here, we outline a method to 3D reconstruct the crystal orientation from a superimposed diffraction pattern of overlapping crystals without sample tilt. Avoiding the typically required tilt series for 3D reconstruction enables not only faster in situ tests but also opens the possibility for more stable and more accurate in situ mechanical testing. The approach laid out here should serve as an inspiration for further research and does not make a claim to be complete.