Close Linear Correlation Research Articles

Open-source software for respiratory rate estimation using single-lead electrocardiograms

Respiratory rate (RR) is a critical vital sign used to assess pulmonary function. Currently, RR estimating instrumentation is specialized and bulky, therefore unsuitable for remote health monitoring. Previously, RR was estimated using proprietary software that extract surface electrocardiogram (ECG) waveform features obtained at several thoracic locations. However, developing a non-proprietary method that uses minimal ECG leads, generally available from mobile cardiac monitors is highly desirable. Here, we introduce an open-source and well-documented Python-based algorithm that estimates RR requiring only single-stream ECG signals. The algorithm was first developed using ECGs from awake, spontaneously breathing adult human subjects. The algorithm-estimated RRs exhibited close linear correlation to the subjects’ true RR values demonstrating an R2 of 0.9092 and root mean square error of 2.2 bpm. The algorithm robustness was then tested using ECGs generated by the ischemic hearts of anesthetized, mechanically ventilated sheep. Although the ECG waveforms during ischemia exhibited severe morphologic changes, the algorithm-determined RRs exhibited high fidelity with a resolution of 1 bpm, an absolute error of 0.07 ± 0.07 bpm, and a relative error of 0.67 ± 0.64%. This optimized Python-based RR estimation technique will likely be widely adapted for remote lung function assessment in patients with cardiopulmonary disease.

Anionic ring-opening polymerization of functional epoxide monomers in the solid state

Despite recent advancements in mechanochemical polymerization, understanding the unique mechanochemical reactivity during the ball milling polymerization process still requires extensive investigations. Herein, solid-state anionic ring-opening polymerization is used to synthesize polyethers from various functional epoxide monomers. The critical parameters of the monomers are investigated to elucidate the unique reactivity of ball milling polymerization. The controllable syntheses of the desired polyethers are characterized via NMR, GPC, and MALDI-ToF analyses. Interestingly, bulky monomers exhibit faster conversions in the solid-state in clear contrast to that observed for solution polymerization. Particularly, a close linear correlation is observed between the conversion of the ball milling polymerization and melting point of the functional epoxide monomers, indicating melting point as a critical predictor of mechanochemical polymerization reactivity. This study provides insights into the efficient design and understanding of mechanochemical polymerization.

Design of squeezing-tube-driven pump for soft pneumatic robotics based on spiral spring winding

Aiming at the demand for high-speed, easy-controllability, and integration of pneumatic soft robots and elastomer actuators, this study presents a squeezing-tube-driven pump (STDP) for soft pneumatic robotics based on spiral spring winding. This concept contains a customized spiral spring and a pneumatic tube with high-elasticity. The spiral spring is driven by an electric motor and coerced into winding deformation. Furthermore, the pneumatic tube is extruded by the spring and then the air in the tube is fast compressed to drive soft pneumatic grippers. The mechanical model and simulation are utilized to explain the operating principle of STDP. The air pressure and rotation angle of the spring under various rotation speeds are in a close linear correlation verified by the experimental results, which provides feasibility for easy controlling and rapid actuation. Finally, fast-gripping tests with an integrated gripper–pump system and a pneumatic muscle actuation test are presented to show the advantages of the proposed pump, respectively.

Radial artery pulse wave velocity: a new characterization technique and the instabilities associated with the respiratory phase and breath-holding

Objective. Pulse wave velocity (PWV) is a key diagnostic parameter of the cardiovascular system’s state. However, approaches aimed at PWV characterization often suffer from inevitable drawbacks. Statistical results demonstrating how closely PWV in the radial artery (RA) and the respiration phase correlate, as well as RA PWV evolution during breath-holding (BH), have not yet been presented in the literature. The aims of this study are (a) to propose a simple robust technique for measuring RA PWV, (b) to reveal the phase relation between the RA PWV and spontaneous breathing, and (c) to disclose the influence of BH on the RA PWV. Approach. The high-resolution remote breathing monitoring method Sorption-Enhanced Infrared Thermography (SEIRT) and the new technique aimed at measuring RA PWV described in this paper were used synchronously, and their measurement data were processed simultaneously. Main results. Spontaneous breathing leaves a synchronous ‘trace’ on the RA PWV. The close linear correlation of the respiration phase and the phase of concomitant RA PWV changes is statistically confirmed in five tested people (Pearson’s r is of the order of 0.5–0.8, P < 0.05). The BH appreciably affects the RA PWV. A phenomenon showing that the RA PWV is not indifferent to hypoxia is observed for the first time. Significance. The proposed technique for RA PWV characterization has high prospects in biomedical diagnostics. The presented pilot study deserves attention in the context of the mutual interplay between respiratory and cardiovascular systems. It may also be useful in cases where peripheral pulse wave propagation helps assess respiratory function.

Energy productivity of sugar sorghum in the central part of the Forest-steppe of Ukraine depending on the harvesting time

Due to global climate change, sugar sorghum (Sorghum saccharatum), due to its fast growth rate, early maturation, efcient use of water and limited need for fertilizers, is the most promising plant for biofuel production in the world. The article presents the results of the study on establishing the dependence of sugar sorghum energy performance indicators on varietal characteristics (varieties 'Silosne 42' and 'Favorit' and hybrids 'Dovista' and 'Medoviy F1') and the green biomass harvesting time. The purpose of the research was to establish the influence of varietal characteristics and harvesting time on sugar sorghum energy productivity in the zone of unstable moisture in the Central part of the Forest-Steppe of Ukraine. The research subject is sugar sorghum energy productivity indicators (yield of green biomass; sugar content of juice; yield of biogas, bioethanol, solid biofuel; total energy yield). The studies were carried out during 2016–2020 in the zone of unstable moisture in the central part of the Forest-Steppe of Ukraine in the conditions of the Bila Tserkva Experimental Breeding Station of the Institute of Bioenergy Crops and Sugar Beet of the National Academy of Sciences of Ukraine. It has been established that the highest yield of biofuel and energy (up to 791.8 GJ/ha) is achieved under growing sugar sorghum of the 'Dovista' hybrid, provided that its biomass is collected in the phase of full seed ripeness (early October). It is advisable to start collecting sugar sorghum biomass for biogas after the panicle throwing phase. To ensure the maximum yield of bioethanol, the optimal time for harvesting green biomass of sugar sorghum is the second decade of September – the frst decade of October. The maximum yield of solid biofuel is achieved under harvesting biomass after the phase of waxy ripeness of grain. The formation of the yield of green biomass of sugar sorghum was more influenced by weather conditions (47.4 %), the influence of varietal characteristics (17.8 %) and the timing of harvesting (12.8 %) was less. But the energy yield was most influenced by the timing of harvesting biomass (37.4 %). A close linear correlation between the energy output and the yield of green (R2=0.81) and dry biomass (R2=0.99) was established. The most ecological plasticity in terms of the total energy yield per unit area turned out to be the 'Medoviy F1' hybrid (b=1.62), which indicates the prospects of growing this hybrid under favorable weather conditions and high level of agricultural technology. Key words: sugar sorghum, varietal characteristics, harvesting time, energy yield, biofuel yield, productivity.

Кластерно-ассоциатная модель вязкости сплава свинец-олово в сопоставлении с моделью Френкеля-Андраде

The article is devoted to the development of a generalized cluster-associated model of the dynamic viscosity of a lead-tin alloy based on the concept of chaotic particles and its relationship with the Frenkel-Andrade viscosity model. In addition to its practical importance, the study of the viscosity of melts of inorganic compounds is also of great scientific interest, since viscosity is the most structurally sensitive characteristic of a substance, which gives an idea of the forces of intermolecular interaction and the mechanism of molecular transport processes in liquids. The accumulation of knowledge in this field allows us to solve many questions related to the theory of the liquid state. The experimental data on the viscosity of melts of inorganic compounds is rather limited, which is explained by the serious difficulties associated with conducting relevant studies. Therefore, it is proposed to use a cluster-associated model for the study of viscosity, which significantly approaches the solution of many problems related to the theory of fluid. The Frenkel-Andrade viscosity model allows us to estimate the yield activation energy. Calculations show that when comparing this energy with the degree of cluster association obtained in the framework of the cluster-association model, a fairly close linear correlation is observed. In this case, the proportionality coefficient makes sense of the activation energy per cluster. This energy does not go beyond the van der Waals energy of the unsaturated intermolecular bond characteristic of the interaction of particles in a liquid.

Direct production of 2,5-diformylfuran from fructose catalysed by Mo-based composite oxides in static air

A series of MxMoyOδ composite oxides (M = Ca, Mn, Fe, Co, Ni, Cu, Zn, Y, Bi, Zr, La or Ce) was synthesized and used for the one-pot direct conversion of fructose to 2,5-diformylfuran (DFF) using atmospheric air as the oxidant. Among these materials, ZrxMoyOδ exhibited the best catalytic performance. Hence, the effects of the Zr/Mo molar ratio and calcination temperature on catalytic performance were investigated in detail and the reaction conditions were also optimized. The highest performing catalyst, Zr1Mo2Oδ, produced a DFF yield of 61 % along with the complete conversion of fructose under the optimized reaction conditions. More importantly, this material also exhibited good recycling stability and could be reused five times without a noticeable loss of activity. These ZrxMoyOδ catalysts were characterized using multiple techniques. Zirconium oxide was found to interact strongly with molybdenum oxide species via the formation of Zr(MoO4)2, thus producing a large number of surface chemisorbed oxygen species. The close linear correlation between DFF yield and surface chemisorbed oxygen confirmed that these oxygen species were the primary active sites for the oxidation reaction.

Plasma concentration and clinical effects of perampanel—The Kork experience

PurposeTo investigate the correlation between steady-state plasma concentrations of perampanel (PER) with efficacy and tolerability in adult patients with difficult-to-treat epilepsy. MethodsPER plasma concentrations were assessed at steady-state conditions in 92 adult patients (57% female, 43% male, mean age 39,5 years, age range 20–73 years). All patients had been treated with PER at a stable dose for at least 3 weeks. Clinical efficacy was assessed on the day of measuring the plasma concentrations by a retrospective analysis of the seizure frequency and adverse effects. ResultsThe mean overall plasma concentration was 323,5 ng/ml (range 19 ng/ml – 2436 ng/ml). The corresponding mean dose was 7,5 mg (range 2 mg – 12 mg). PER dose and plasma concentration showed a close linear correlation. Plasma levels and doses varied widely concerning both efficacy and tolerability of PER. The differences between plasma levels of responders and non-responders were not statistically significant. Therefore a clinically useful general reference range could not be defined. ConclusionOur data do not indicate a reliable therapeutic range for PER plasma concentrations. Individual reference ranges varied widely. Therapeutic drug monitoring (TDM) may still be helpful in certain clinical situations.

Clusters: Viscosity Cause?

The significance of the work is determined by the need to develop a cluster theory of the liquid state of a substance in order to more deeply substantiate the viscosity, which is still expressed by empirical parameters within the framework of ideal ideas about the stratified flow of a liquid. According to the reference data on the dynamic viscosity of the melts for chlorides of the first group of the Periodic System, the approximating dependences in the form of cluster-associate and Frenkel’s models were constructed at various temperatures. The first model is based on taking into account the share of particles that cannot overcome the thermal melting barrier and thus serve to form virtual clusters and associates while preserving the structural motifs of the solid phase. In the framework of the cluster-associate viscosity model developed by the authors, these formations determine the melt viscosity and serve as flow units to which the energy of fluid motion is applied. The Frenkel’s model allows us to estimate the activation energy of fluidity. Calculations show that by comparing this energy with the degree of cluster association obtained in the framework of the cluster-associate model, a fairly close linear correlation is obtained, and the proportionality coefficient has the meaning of the activation energy per cluster. This energy does not go beyond the van der Waals energy of the unsaturated intermolecular bond characteristic of the interaction of particles in a liquid. This confirms the earlier established by the authors a similar pattern for melts of simple substances, based on the understanding of fluidity as a consequence of the destruction of cluster associates while preserving the clusters themselves.

Differences in lamina joint anatomy cause cultivar differences in leaf inclination angle of rice

ABSTRACTLeaf erectness is an important agronomic trait for improving canopy photosynthesis in rice. It is well known that leaf inclination angle (LIA) decreases after expansion during ripening. However, the high-yielding indica cultivar ‘Takanari’ retains a greater LIA during ripening than the high-quality japonica cultivar ‘Koshihikari’. To clarify the cause of the cultivar difference in LIA, we investigated anatomical characteristics of the lamina joint of a flag leaf. We found a close linear correlation between LIA at the centre and at the base of the leaf blade in both cultivars during ripening. The length of the lamina joint increased significantly more on the adaxial side of a leaf (the margin of the collar) than on the abaxial side (the abaxial side of the central part of the collar) in ‘Koshihikari’ after leaf expansion, but there was no clear difference in ‘Takanari’. We found a close linear correlation between the ratio of lamina joint length on the adaxial to abaxial sides and LIA in ‘Koshihikari’ and ‘Takanari’ during ripening. In ‘Koshihikari’, the average length of cells on the adaxial side increased significantly after leaf expansion, with no significant increase in that on the abaxial side and no significant change in cell number on either side. In ‘Takanari’, cell length and cell number showed no significant changes on either side of the lamina joint. We conclude that the cultivar difference in LIA during ripening is caused mainly by cell elongation on the adaxial side of the lamina joint.List of Abbreviations: k: light extinction coefficient; LIA: leaf inclination angle; QTL: quantitative trait locus

On the origin of the marine zinc–silicon correlation

The close linear correlation between the distributions of dissolved zinc (Zn) and silicon (Si) in seawater has puzzled chemical oceanographers since its discovery almost forty years ago, due to the apparent lack of a mechanism for coupling these two nutrient elements. Recent research has shown that such a correlation can be produced in an ocean model without any explicit coupling between Zn and Si, via the export of Zn-rich biogenic particles in the Southern Ocean, consistent with the observation of elevated Zn quotas in Southern Ocean diatoms. Here, we investigate the physical and biological mechanisms by which Southern Ocean uptake and export control the large-scale marine Zn distribution, using suites of sensitivity simulations in an ocean general circulation model (OGCM) and a box-model ensemble. These simulations focus on the sensitivity of the Zn distribution to the stoichiometry of Zn uptake relative to phosphate (PO4), drawing directly on observations in culture. Our analysis reveals that OGCM model variants that produce a well-defined step between relatively constant, high Zn:PO4 uptake ratios in the Southern Ocean and low Zn:PO4 ratios at lower latitudes fare best in reproducing the marine Zn–Si correlation at both the global and the regional Southern Ocean scale, suggesting the presence of distinct Zn-biogeochemical regimes in the high- and low-latitude oceans that may relate to differences in physiology, ecology or (micro-)nutrient status. Furthermore, a study of the systematics of both the box model and the OGCM reveals that regional Southern Ocean Zn uptake exerts control over the global Zn distribution via its modulation of the biogeochemical characteristics of the surface Southern Ocean. Specifically, model variants with elevated Southern Ocean Zn:PO4 uptake ratios produce near-complete Zn depletion in the Si-poor surface Subantarctic Zone, where upper-ocean water masses with key roles in the global oceanic circulation are formed. By setting the main preformed covariation trend within the ocean interior, the subduction of these Zn- and Si-poor water masses produces a close correlation between the Zn and Si distributions that is barely altered by their differential remineralisation during low-latitude cycling. We speculate that analogous processes in the high-latitude oceans may operate for other trace metal micronutrients as well, splitting the ocean into two fundamentally different biogeochemical, and thus biogeographic, regimes.

INFLUENCE OF MAIN TELECONNECTIONS OF THE NORTH HEMISPHERE ON REGIME OF PRECIPITATION ON THE TERRITORY OF UKRAINE

Abstract Problem Statement and Purpose. Since the atmospheric circulation is the main manifestation of climate change as covering all components of weather conditions is of interest to investigate the effect of this constitutive of climate factor on the formation fields of precipitation in the Euro-Mediterranean region due to global climate change. The purpose of this article is to determine the impact of major Northern Hemisphere teleconnections the regime of precipitation on the territory of Ukraine in the winter season using physical-statistical approach. Data & Methods. To study the relationship between climate parameters in the western part of the Eurasian continent used series of monthly sums of precipitation (December, January, February) at 30 weather stations Ukraine, evenly spaced on its territory, climate NAO index and climate NCP index for the period 1976-2005. The implementation of tasks using the component and correlation analysis, research methods and statistical structure of non-stationary time series. Results. Results of the study impact of major Northern Hemisphere teleconnections on precipitation regime on the territory of Ukraine in the late twentieth and early twenty-first centuries, which made for long-term data indicate ambiguity of these processes in different seasons. With component analysis performed random fields parameterization monthly rainfall in 30 stations of Ukraine for the period 1976-2005 years. Perennial field were presented two (three) uncorrelated parameters (major components) linearly connected components of the original vector and therefore are generalized characteristics of rainfall during the winter season for the whole territory of Ukraine. Provided ≥ 70% in January, the first two eigenvalues (two eigenvectors and two major components) 71.6% of the total exhaust dispersion field precipitation in December and February – the first three (respectively 70.8% and 71.2%). Time Series Analysis Principal Component possible to determine the interannual variability of component long-time – 3-5 years in December and February and 5-9 years – in January. Also since the 90s trend to increase rainfall in Ukraine in January and February; in December – on the contrary. We believe that this trend will continue until 2020. The impact of the North Caspian Marine fluctuations (PMKK) on the formation of precipitation winter season in Ukraine has close (mainly inverse) linear correlation and only state in December PMKK sees a direct correlation with the regime of precipitation in January in our countries. The value of pair correlation coefficients indicate statistically significant (P = 90%) tight line (direct and inverse) correlation between monthly rainfall in Ukraine in the winter season with the North Atlantic oscillation. In the central month of the winter season dominated by the positive phase PMKK – in the western pole PMKK (waters of the North Sea) was observed strengthening anticyclonic circulation and increased cyclonic activity that resulted in a northeast movement of air masses in Central Europe. The statistical time series structure NAO index in January indicates a predominance of positive phase of the North Atlantic oscillation in this period, which contributed to expansion of the Icelandic low and the Azores high, and this situation leads to increased zonal circulation.

Relation between the dynamic modulus of elasticity and the static modulus of elasticity, the modulus of rupture of mandarin peel–sawdust composite board

This study was conducted to determine the relation between the dynamic modulus of elasticity and the static modulus of elasticity, and the relation between the dynamic modulus of elasticity and the modulus of rupture of mandarin peel–sawdust composite boards. The result of this study was as follows: There was highly close linear correlation between the dynamic modulus of elasticity and the static modulus of elasticity, modulus of rupture of the mandarin peel–sawdust composite boards with the density of 0.4, 0.5 and 0.6 g/cm3, and the mandarin peel content of 10, 20, 30 and 40%, thus, the static modulus of elasticity and the modulus of rupture can be predicted from the dynamic modulus of elasticity measured by free vibration test using resonance frequency.

Daytime formation of nitrous acid at a coastal remote site in Cyprus indicating a common ground source of atmospheric HONO and NO

Abstract. Characterization of daytime sources of nitrous acid (HONO) is crucial to understand atmospheric oxidation and radical cycling in the planetary boundary layer. HONO and numerous other atmospheric trace constituents were measured on the Mediterranean island of Cyprus during the CYPHEX (CYprus PHotochemical EXperiment) campaign in summer 2014. Average volume mixing ratios of HONO were 35 pptv (±25 pptv) with a HONO ∕ NOx ratio of 0.33, which was considerably higher than reported for most other rural and urban regions. Diel profiles of HONO showed peak values in the late morning (60 ± 28 pptv around 09:00 local time) and persistently high mixing ratios during daytime (45 ± 18 pptv), indicating that the photolytic loss of HONO is compensated by a strong daytime source. Budget analyses revealed unidentified sources producing up to 3.4 × 106 molecules cm−3 s−1 of HONO and up to 2.0 × 107 molecules cm−3 s−1 NO. Under humid conditions (relative humidity &gt; 70 %), the source strengths of HONO and NO exhibited a close linear correlation (R2 = 0.72), suggesting a common source that may be attributable to emissions from microbial communities on soil surfaces.

Effect of charge on the conformation of highly basic peptides including the tail regions of histone proteins by ion mobility mass spectrometry

The first systematic and comprehensive study of the charging behaviour and effect of charge on the conformation of specifically constructed arginine-rich peptides and its significance to the N- and C-terminal basic tail regions of histone proteins was conducted using ion mobility mass spectrometry (IM-MS). Among the basic amino acids, arginine has the greatest impact on the charging behaviour and structures of gas phase ions by virtue of its high proton affinity. A close linear correlation was found between either the maximum charge, or most abundant charge state, that the peptides support and their average collision cross section (CCS) values measured by ion mobility mass spectrometry. The calculated collision cross sections for the lowest energy solution state models predicted by the PEP-FOLD algorithm using a modified MOBCAL trajectory method were found to best correlate with the values measured by IM-MS. In the case of the histone peptides, more compact folded structures, supporting less than the maximum number of charges, were observed. These results are consistent with those previously reported for histone dimers where neutralization of the charge at the basic residues of the tail regions did not affect their CCS values.

A New Method of Preparing Gel for DGT Technique and Application to the Soil Phosphorus Availability Test

ABSTRACTThere are different methods for soil phosphorus (P) availability assessment. Researchers have recently introduced a new method called diffusive gradients in thin films (DGT) to evaluate P availability in soils. The aim of this study was manufacturing DGT gel using copolymerization of acrylamide and allylic double bonds agarose to replace the patented agarose as a cross-linker. We evaluated the efficacy of the prepared gel and used the assembled DGT with that gel in 10 calcareous soils. We compared the available P measured with the assembled DGT in those soils to Olsen’s P measured in the same soils. Corn plant (Zea mays L.) was also grown in those soils in a greenhouse for two months. Results showed that the diffusion coefficient of P ions in the gel with 0.3% of allylagarose at 25 °C was 6.9 * 10–6 cm2.s−1, implying that P ions were allowed to diffuse freely through the prepared diffusive gel. Measured P by the assembled DGT showed a close linear correlation (r2 = 0.98) with the P concentrations measured in soil solutions extracted by the Olsen method. This demonstrates the prepared allylagarose cross-linked gels’ efficiency and thus the reliability of the assembled DGT in easily and rapidly measuring the soil’s available P. The P, as measured by the assembled DGT in the examined soils, indicated a little lower correlation coefficient (r = 0.77) than those measured by the Olsen method (r = 0.88). However, the CE values measured by DGT showed a good correlation with P uptake by the roots (r = 0.88, p ≤ 0.01). The best correlation between CE and P content in corn occurred for the measurements made after 48 h of DGT placement in soils. The 20-h measurements had about the same r value, indicating that 20 h is sufficient for the placement of DGT assembly in the soil before its removing and measuring the available P. According to our findings, acrylamide—allylagarose gel as a diffusive gel in DGT was found to be suitable for P measurements in both aqueous solutions and soil.

Differentiation between recurrent gliomas and radiation necrosis using arterial spin labeling perfusion imaging.

Arterial spin labeling (ASL) magnetic resonance (MR) perfusion imaging has been proposed as an effective method to measure brain tumor perfusion. The aim of the present study was to evaluate the utility of this technique in the differentiation of recurrent gliomas from radiation necrosis. Twenty-one patients with surgically treated primary gliomas, including 16 cases of recurrent glioma and 5 of radiation necrosis were examined using 3.0T MR imaging (MRI). ASL and dynamic susceptibility contrast-weighted (DSC) perfusion MRI scans were performed. Maps of normalized cerebral blood flow (CBF) in ASL imaging and cerebral blood volume (CBV) in DSC imaging were computed and analyzed in the regions of interest. In cases of glioma recurrence, the normalized ASL-CBF ratio (4.45±2.72) was higher than that in cases of radiation injury (1.22±0.61) (P<0.01). The normalized DSC-relative CBV ratio was also significantly higher in glioma recurrence (3.38±2.08) than it was in radiation injury (1.09±0.55) (P<0.05). A close linear correlation was found between the ASL and DSC MRI techniques (linear regression coefficient, R=0.85; P=0.005) in the differentiation of recurrent glioma from radiation injury. The results indicate that ASL perfusion is an accurate method of distinguishing between glioma recurrence and radiation necrosis.

Influence of particle shape on slurry wear of white iron

Slurry particle shape is an important variable in determining equipment life in mineral processing operations, especially in the grinding circuit. Slurry particles here are generally coarse, sharp and at high concentrations. Little information is available to guide practitioners in measuring particle shape or understanding the impact of particle shape on the wear rate of the hard white irons that are commonly used in processing equipment.The first part of the current work has explored the differences between 2 methods of measuring particle shape – Circularity Factor (CF) a ratio of the perimeter to projected area of the particles and spike parameter (SPQ) which is an analytical method of fitting triangles to the prominent features of the particle outline. Calculating the CF and SPQ for a wide range of particle shapes (from angular to round) found a close linear correlation between the two. This was surprising given that the more complex SPQ methodology was developed to improve particle shape characterisation.The second part of the work used a large scale Coriolis tester to determine the effect of particles of different shape on the wear rate of white cast iron. To simulate the type of wear experienced in grinding circuits a range of different particle shapes with similar CF to those observed in field applications were tested. Coarse silicon carbide, alumina and silica sand particles were individually run through the Coriolis tester. By recirculating the particles in the rig, the shape became more rounded (with CF eventually spanning the range seen in field applications) without dramatically impacting particle size. An inverse power law relationship was found between the CF and the erosion rate for white iron. This correlation should be able to be used to determine the impact of changes in CF on equipment wear life.A third element of the work was a microscopic investigation of the worn sample surface from the Coriolis tester to identify changes in wear mechanisms with particle hardness and shape. In addition a comparison was made with worn slurry pump parts to ensure that the mechanisms of wear from the Coriolis test were representative of those seen in equipment in the field.

Modeling Leaf Image, Chlorophyll Fluorescence, Reflectance From SPAD Readings

Many remote sensing technologies were used to evaluate plant physioecology. However, few studies currently existed on the comparisons and the relationships among various remote sensing analyses methods. The objective of our study was to investigate the relationship of leaf image, chlorophyll fluorescence, reflectance with SPAD, and build the models from SPAD using the data obtained from rice and barley crops. Two pot experiments, one in 2009 and the other one in 2010, were conducted to study the relationship between these characteristics at a leaf scale. Three rice varieties (M17, M15, Xiushui 09) and three barley varieties (Hua 30, Zhepi 33, Zhexiu 12) were selected in our greenhouse experiment. The results showed that there was a highly significant relationship between R (red channel of the leaf image), G (green channel of the image), R550 (reflectance at 550 nm), and PRI (photochemical reflectance index), with SPAD (SPAD-502 readings) for rice and barley crops. Close linear correlation was found between leaf chlorophyll maximal fluorescence ( ${{\bf F}_{\bf m}}$ ) and ratio of variable to maximal chlorophyll fluorescence ( ${{\bf F}_{\bf v}}/{{\bf F}_{\bf m}}$ ) with SPAD reading for rice. However, no significant relationship between ${{\bf F}_{\bf m}}$ and ${{\bf F}_{\bf v}}/{{\bf F}_{\bf m}}$ with SPAD reading was found in barley. Linear and logarithmic equations could be used to describe the relationship between R, G, R550, PRI, ${{\bf F}_{\bf m}}$ , and ${{\bf F}_{\bf v}}/{{\bf F}_{\bf m}}$ with SPAD reading. It suggested that leaf image analysis had stronger relationship with SPAD than reflectance or leaf chlorophyll fluorescence of the two crops of rice and barley.

Chemical mass balance of 300 °C non-volatile particles at the tropospheric research site Melpitz, Germany

Abstract. In the fine-particle mode (aerodynamic diameter &lt; 1 μm) non-volatile material has been associated with black carbon (BC) and low-volatile organics and, to a lesser extent, with sea salt and mineral dust. This work analyzes non-volatile particles at the tropospheric research station Melpitz (Germany), combining experimental methods such as a mobility particle-size spectrometer (3–800 nm), a thermodenuder operating at 300 °C, a multi-angle absorption photometer (MAAP), and an aerosol mass spectrometer (AMS). The data were collected during two atmospheric field experiments in May–June 2008 as well as February–March 2009. As a basic result, we detected average non-volatile particle–volume fractions of 11 ± 3% (2008) and 17 ± 8% (2009). In both periods, BC was in close linear correlation with the non-volatile fraction, but not sufficient to quantitatively explain the non-volatile particle mass concentration. Based on the assumption that BC is not altered by the heating process, the non-volatile particle mass fraction could be explained by the sum of black carbon (47% in summer, 59% in winter) and a non-volatile organic contribution estimated as part of the low-volatility oxygenated organic aerosol (LV-OOA) (53% in summer, 41% in winter); the latter was identified from AMS data by factor analysis. Our results suggest that LV-OOA was more volatile in summer (May–June 2008) than in winter (February–March 2009) which was linked to a difference in oxidation levels (lower in summer). Although carbonaceous compounds dominated the sub-μm non-volatile particle mass fraction most of the time, a cross-sensitivity to partially volatile aerosol particles of maritime origin could be seen. These marine particles could be distinguished, however from the carbonaceous particles by a characteristic particle volume–size distribution. The paper discusses the uncertainty of the volatility measurements and outlines the possible merits of volatility analysis as part of continuous atmospheric aerosol measurements.