Slope Of Regression Line Research Articles

Online application of the periodic linear regression method for daily monitoring of photovoltaic systems performance

This paper presents an analysis of the performance of photovoltaic (PV) systems using daily applications of the periodic linear regression method to the performance indicators Final Yield (YF) and Reference Yield (YR). The research was conducted on PV systems installed on rooftops and ground at the Federal Institute of Education, Science, and Technology of Goiás (IFG), Itumbiara Campus, from July 2022 to August 2023. The Energy Monitoring and Management Software (SMGE) was developed to calculate the performance indicators and perform linear regression to analyze the performance of the systems. The results demonstrate that the efficiency of the systems can be monitored by analyzing variations in the slopes of the linear regression lines. An increase in energy conversion efficiency was observed following the cleaning of the PV panels, as reflected in significant changes in the regression slopes. Additionally, natural events, such as rainfall, positively impacted system efficiency. These findings highlight the importance of proper maintenance of PV panels, whether through scheduled cleaning or natural events like rain.

Comparing repeated end range movements and Kinesio taping effects on head and neck movement pattern and discomfort in smartphone users

IntroductionUsing smartphones has increased exponentially, especially after the COVID-19 pandemic. However, there is a relationship between neck flexion angle during working with a smartphone and neck musculoskeletal disorders. Therefore, this study compares the effect of Kinesio taping and Repeated End Range Movements (RERM) on head and neck flexion angles changes during texting and discomfort after texting with a smartphone. MethodTwenty-four smartphone users participated in this cross-over study. All of 24 subjects were experimented with the control, RERM and taping conditions. They filled Numeric Rating Scale questionnaire before and after 30 min of texting. In addition, their head and neck flexion angles were measured during the task by photogrammetry. ResultsIn the RERM group, individuals felt significantly less discomfort than the control group after the task (P = 0.032). Although the slope of average head and neck flexion angles linear regression lines of all the three groups was positive before the break time, it became negative in the taping and control groups after the break time. In addition, the linear regression of average head and neck flexion angles of the RERM group was significantly different (P < 0.001). ConclusionRERM can effectively maintain normal head and neck movement pattern during and reduce neck discomfort after texting on smartphone.

The biodemography of human aging (Gompertz-Makeham law) applied to surgical mortality modelling: a retrospective national cohort study.

The Gompertz-Makeham law describes a characteristic pattern of mortality in human populations where death rate is near constant between age 18 and 30 years (Makeham's Law) and rises exponentially thereafter (Gompertz Law). This pattern has not been described in surgical populations, but if true, would have important implications for understanding surgical risk and design and interpretation of surgical risk models. The aim of this study was to determine if the Gompertz-Makeham law applies to perioperative mortality risk and the conditions under which it may apply. We examined the relationship between age and 1-month postoperative all-cause mortality risk in a 10-year New Zealand administrative dataset comprising of 5,615,100 surgical procedures from 2007 to 2016. The dataset includes patient and surgical factors including procedures, American Society of Anesthesiologist's physical status score (ASA-PS), diagnoses and other relevant details. Semi-logarithmic graphs of mortality risk and age were plotted. Linear regression models were fitted, with regression line slope and Pearson's correlation coefficient calculated. The primary outcome occurred in 114,782 (2.0%) of 5,615,100 included participants. The Gompertz-Makeham law seems to apply to the national surgical population as a whole (slope = 0.0241, R2 = 0.971). The law applies in all subgroups studied including sex, ASA-PS, surgical acuity, surgical severity category, cancer status and ethnicity (slopes 0.0066 to 0.0307, R2 0.771 to 0.990). Important interactions were found between age, mortality risk and three high risk groups (cancer diagnosis, ASA-PS 4-5 and high surgical severity). The Gompertz-Makeham law seems to apply in a national cohort of surgical patients. The inflection point for increased 1-month risk is apparent at age 30 years. A strict exponential rise in mortality risk occurs thereafter. This finding improves our understanding of surgical risk and suggests a concept-driven approach to improve modelling of age and important interactions in future surgical risk models.

Hip Instability in Children With Spinal Muscular Atrophy: A Retrospective Study.

Hip subluxation and dislocation are known problems for children with spinal muscular atrophy (SMA). Medical complexity of these children typically results in absence of monitoring and intervention for pathologic hips. Patterns of hip migration and acetabular morphology in SMA have not been described. This study examines the natural progression of hip instability across all types of SMA in a pediatric population. Following institutional review board approval, a retrospective chart review of all children with SMA at our institution was performed. All x-rays taken before the age of 18 years containing adequate projections of the pelvis were measured for Reimer migration index (MI), acetabular depth ratio (ADR), and acetabular index (AI). Demographics and clinical data were collected including use of nusinersen, ambulatory status, contractures, and hip pain. Linear mixed effects model was fit to serial MI measures of individual hips with fixed effects consisting of SMA type, age at x-ray, and their interaction. ADR and AI measures were similarly modeled following conversion of raw values to z-scores based on the model developed by Novais et al Slope indicated rate of measure change as a function of age. Forty-five children (22 males) with SMA types 1 to 3 were included in this retrospective study. Six children were classified as type 1, 25 were type 2, and 14 were type 3. The interaction of age by SMA type was statistically significant (P=0.01), indicating a difference in the rate of hip subluxation between the 3 SMA types as measured by MI. By age 4, MI values were different from one another across all 3 groups (P<0.01). ADR decreased with age across all SMA types. The slopes of ADR regression lines were negative and statistically significant between the 3 groups (P=0.002). AI values were higher for all types of SMA, which is the opposite of expected in normal hips. Hip subluxation occurs across all SMA types, most rapidly in SMA type 1. Regression lines of ADR and AI compared with those seen in unaffected populations suggest hips in children with SMA demonstrate a difference in morphology of the acetabulum and do not follow normal adaptive remodeling. As treatments advance and the population of SMA patients becomes more mobile, there is an increased need to monitor hip instability in children with SMA, thus making orthopaedic management an important consideration.

Accuracy of Instrumented Mouthguards During Direct Jaw Impacts Seen in Boxing.

Measuring head kinematics data is important to understand and develop methods and standards to mitigate head injuries in contact sports. Instrumented mouthguards (iMGs) have been developed to address coupling issues with previous sensors. Although validated with anthropomorphic test devices (ATDs), there is limited post-mortem human subjects (PMHS) data which provides more accurate soft tissue responses. This study evaluated two iMGs (Prevent Biometrics (PRE) and Diversified Technical Systems (DTS) in response to direct jaw impacts. Three unembalmed male cadaver heads were properly fitted with two different boil-and-bite iMGs and impacted with hook (4m/s) and uppercut (3m/s) punches. A reference sensor (REF) was rigidly attached to the base of the skull, impact kinematics were transformed to the head center of gravity and linear and angular kinematic data were compared to the iMGs including Peak Linear Acceleration, Peak Angular Acceleration, Peak Angular Velocity, Head Injury Criterion (HIC), HIC duration, and Brain Injury Criterion. Compared to the REF sensor, the PRE iMG underpredicted most of the kinematic data with slopes of the validation regression line between 0.72 and 1.04 and the DTS overpredicted all the kinematic data with slopes of the regression line between 1.4 and 8.7. While the PRE iMG was closer to the REF sensor compared to the DTS iMG, the results did not support the previous findings reported with use of ATDs. Hence, our study highlights the benefits of using PMHS for validating the accuracy of iMGs since they closely mimic the human body compared to any ATD's mandible.

Determinants of prehospital and in-hospital delay in patients with symptomatic carotid stenosis and their influence on the outcome after elective carotid endarterectomy

BackgroundThis study analyses the determinants of prehospital (index event to admission) and in-hospital delay (admission to carotid endarterectomy (CEA)). In addition, the analysis addresses the association between prehospital or in-hospital...

Evaluating the growth performance of all male sex reversal and mixed ser tilapia (Oreochromis niloticus) cultured in earthen ponds in Binh Phuo province, Vietnam

The study was conducted to evaluate the growth performance, survival rate and yield of all male sex reversed and mixed sex Nile tilapia (Oreochromis niloticus) cultured in earthen ponds for 180 days. The reversed sex and mixed sex fingerlings (mean weight 7.43 ± 0.35 g) was randomly stocked in six earthen ponds (1,000 m2/pond). The stocking density maintained was 5 fish/m2. The stocked fish were fed a commercial pellet feed containing 35% crude protein. The feeding rate was adjusted according the size of fish, 5% at the beginning to 3% at harvest. Water environment parameters including dissolved oxygen (DO) (4.3 ± 0.8 mg/L), temperature (30 ± 0.7°C), NH3 (0.18 ± 0.2 mg/L), and pH (6.9 ± 0.5) were always within the appropriate range for the normal growth and development of tilapia. The growth rate of sex reversed tilapia was significantly higher (P &lt; 0.05) than that of mixed tilapia throughout the experiment. The harvest weight and length of reversed sex tilapia were 410.5 ± 5.15 g and 25.48 ± 0.48 cm, respectively, and were significantly higher than that of mixed sex tilapia (P &lt; 0.05). The survival rates and feed conversion ratio (FCR) of mono and mixed sex were 90.1% and 89.9%, respectively, but no significant differences were observed (P &gt; 0.05). The relationship of fish lengths and weights expressed by power function revealed that the slope of the length weight regression lines was normal for reversed sex (2.72) and mixed sex Tilapia (2.93) with the high correlation coefficient (&gt; 0.9). The findings of this study demonstrate that reversed sex tilapia has better growth performance compared to mixed sex tilapia. Therefore, reversed sex fingerlings should be used in commercial farming to increase tilapia production.

Relationship Between Cerebrospinal Fluid Alzheimer's Disease Biomarker Values Measured via Lumipulse Assays and Conventional ELISA: Single-Center Experience and Systematic Review.

Although Lumipulse assays and conventional ELISA are strongly correlated, the precise relationship between their measured values remains undetermined. To determine the relationship between Lumipulse and ELISA measurement values. Patients who underwent cerebrospinal fluid (CSF) Alzheimer's disease (AD) biomarker measurements and consented to biobanking between December 2021 and June 2023 were included. The relationship between values measured via Lumipulse assays and conventional ELISA were evaluated by Passing-Bablok analyses for amyloid-β 1-42 (Aβ42), total tau (t-tau), and phospho-tau 181 (p-tau 181). Studies using both assays were systematically searched for in PubMed and summarized after quality assessment. Regression line slopes and intercepts were 1.41 (1.23 to 1.60) and -77.8 (-198.4 to 44.5) for Aβ42, 0.94 (0.88 to 1.01) and 98.2 (76.9 to 114.4) for t-tau, and 1.60 (1.43 to 1.75) and -21.1 (-26.9 to -15.6) for p-tau181. Spearman's correlation coefficients were 0.90, 0.95, and 0.95 for Aβ42, t-tau, and p-tau181, respectively. We identified 13 other studies that included 2,117 patients in total. Aβ42 slope varied among studies, suggesting inter-lab difference of ELISA. The slope and intercept of t-tau were approximately 1 and 0, respectively, suggesting small proportional and systematic differences. Conversely, the p-tau181 slope was significantly higher than 1, distributed between 1.5-2 in most studies, with intercepts significantly lower than 0, suggesting proportional and systematic differences. We characterized different relationship between measurement values for each biomarker, which may be useful for understanding the differences in CSF biomarker measurement values on different platforms and for future global harmonization.

Endplate weakening during cage bed preparation significantly reduces endplate load capacity

PurposeTo analyze the effect of endplate weakness prior to PLIF or TLIF cage implantation and compare it to the opposite intact endplate of the same vertebral body. In addition, the influence of bone quality on endplate resistance was investigated.MethodsTwenty-two human lumbar vertebrae were tested in a ramp-to-failure test. One endplate of each vertebral body was tested intact and the other after weakening with a rasp (over an area of 200 mm2). Either a TLIF or PLIF cage was then placed and the compression load was applied across the cage until failure of the endplate. Failure was defined as the first local maximum of the force measurement. Bone quality was assessed by determining the Hounsfield units (HU) on CT images.ResultsWith an intact endplate and a TLIF cage, the median force to failure was 1276.3N (693.1–1980.6N). Endplate weakening reduced axial endplate resistance to failure by 15% (0–23%). With an intact endplate and a PLIF cage, the median force to failure was 1057.2N (701.2–1735.5N). Endplate weakening reduced axial endplate resistance to failure by 36.6% (7–47.9%). Bone quality correlated linearly with the force at which endplate failure occurred. Intact and weakened endplates showed a strong positive correlation: intact-TLIF: r = 0.964, slope of the regression line (slope) = 11.8, p < 0.001; intact-PLIF: r = 0.909, slope = 11.2, p = 5.5E−05; weakened-TLIF: r = 0.973, slope = 12.5, p < 0.001; weakened-PLIF: r = 0.836, slope = 6, p = 0.003.ConclusionWeakening of the endplate during cage bed preparation significantly reduces the resistance of the endplate to subsidence to failure: endplate load capacity is reduced by 15% with TLIF and 37% with PLIF. Bone quality correlates with the force at which endplate failure occurs.

Experimental evidence that carbon-ion radiotherapy utilizes cytotoxic T lymphocyte-mediated anti-tumor immunity for shrinking tumors compared to X-ray therapy

The therapeutic efficacy of radiotherapy (RT) is primarily driven by two factors: biophysical DNA damage in cancer cells and radiation-induced anti-tumor immunity. However, Anti-tumor immune responses between X-ray RT (XRT) and carbon-ion RT (CIRT) remain unclear. In this study, we, employed mouse models to assess the immunological contribution, especially cytotoxic T-lymphocyte (CTL)-mediated immunity, to the therapeutic effectiveness of XRT and CIRT in shrinking tumors. We irradiated mouse intradermal tumors of B16F10-ovalbumin (OVA) mouse melanoma cells and 3LL-OVA mouse lung cancer cells with carbon-ion beams or X-rays in the presence or absence of CTLs. CTL removal was performed by administration of anti-CD8 monoclonal antibody (mAb) in mice. Based on tumor growth delay, we determined the tumor growth and regression curves. The enhancement ratio (ER) of the slope of regression lines in the presence of CTLs, relative to the absence of CTLs, indicates the dependency of RT on CTLs for shrinking mouse tumors, and the biological effectiveness (RBE) of CIRT relative to XRT were calculated. Tumor growth curves revealed that the elimination of CD8+ CTLs by administrating anti-CD8 mAb accelerated tumor growth compared to the presence of CTLs in both RTs. The ERs were larger in CIRT compared to XRT in the B16F10-OVA tumor models, but not in the 3LL-OVA models, suggesting a greater contribution of CTL-mediated anti-tumor immunity to tumor reduction in CIRT compared to XRT in the B16F10-OVA tumor model. In addition, the RBE values for both models were larger in the presence of CTLs compared to models without CTLs, suggesting that CIRT may utilize CTL-mediated anti-tumor immunity more than X-ray. The findings from this study suggest that although immunological contribution to therapeutic efficacy may vary depending on the type of tumor cell, CIRT utilizes CTL-mediated immunity to a greater extent compared to XRT.

Trends and Costs of Minimally Invasive Surgery for Kidney Cancer in the US: A Population-based Study

ObjectiveTo analyze temporal trends and costs associated with the use of minimally invasive surgery (MIS) for kidney cancer in the US over the past decade. To examine the impact of social determinants of health (SDOH) on perioperative outcomes. MethodsThe PearlDiver Mariner, a national database of insurance billing records, was queried for this retrospective observational cohort analysis. The MIS population was identified and stratified according to treatment modality, using International Classification of Diseases (ICD) and current procedural terminology (CPT) codes. SDOH were assessed using ICD codes. Negative binomial regression was used to evaluate the overall number of renal MIS and Cochran-Armitage tests to compare the utilization of different treatment modalities, over the study period. Multivariable logistic regression analysis identified predictors of perioperative complications. ResultsA total of 80,821 MIS for kidney cancer were included. Minimally invasive partial nephrectomy (MIPN) adoption as a fraction of total MIS increased significantly (slope of regression line, reg. = 0.026, p<.001). Minimally invasive radical nephrectomy (MIRN) ($26,9k±40,9k) and renal ablation (RA) ($18,9k±31,6k) were the most expensive and the cheapest procedure, respectively. No statistically significant difference was observed in terms of number of complications (p=.06) and presence of SDOH (p=.07) among the treatment groups. At multivariable analysis, patients with SDOH undergoing MIRN had higher odds of perioperative complications, while RA had a significantly lower probability of perioperative complications. ConclusionsThis study describes the current management of kidney cancer in the US, offering a socioeconomic perspective on the impact of this disease in everyday clinical practice. Data AvailabilityRaw data generated during and/or analyzed during the current study are available from the corresponding author on reasonable request.

Limb Volume Measurements: A Comparison of Circumferential Techniques and Optoelectronic Systems against Water Displacement.

Accurate measurements of limb volumes are important for clinical reasons. We aimed to assess the reliability and validity of two centimetric and two optoelectronic techniques for limb volume measurements against water volumetry, defined as the gold standard. Five different measurement methods were executed on the same day for each participant, namely water displacement, fixed-height (circumferences measured every 5 (10) cm for the upper (lower limb) centimetric technique, segmental centimetric technique (circumferences measured according to proportional height), optoelectronic plethysmography (OEP, based on a motion analysis system), and IGOODI Gate body scanner technology (which creates an accurate 3D avatar). A population of 22 (15 lower limbs, 11 upper limbs, 8 unilateral upper limb lymphoedema, and 6 unilateral lower limb lymphoedema) participants was selected. Compared to water displacement, the fixed-height centimetric method, the segmental centimetric method, the OEP, and the IGOODI technique resulted in mean errors of 1.2, 0.86, -16.0, and 0.71%, respectively. The corresponding slopes (and regression coefficients) of the linear regression lines were 1.0002 (0.98), 1.0047 (0.99), 0.874 (0.94) and 0.9966 (0.99). The centimetric methods and the IGOODI system are accurate in measuring limb volume with an error of <2%. It is important to evaluate new objective and reliable techniques to improve diagnostic and follow-up possibilities.

The Effect of Convective/Advective Precipitation Partitions on the Precipitation Isotopes in the Monsoon Regions of China: A Case Study of Changsha

Abstract Convective/advective precipitation partitions refer to the divisions of precipitation that are either convective or advective in nature, relative to the total precipitation amount. These distinct partitions can have a significant influence on the stable isotope composition of precipitation. This study analyzed and compared the effect of precipitation partitions on δ18O in precipitation (δ18Op) by using daily precipitation stable isotope data from Changsha station and monthly precipitation stable isotope data from the Global Network of Isotopes in Precipitation (GNIP), under different time scales, time intervals (i.e., annual, warm season, and cold season), and precipitation intensities. The results showed that the correlation between the convective precipitation fraction (CPF) and total precipitation amount was influenced by the intensity of convection in different time intervals. On both the daily and monthly scales, the CPF decreased as the precipitation amount increased in the warm season, while it increased with increasing precipitation amount in the cold season. Regardless of the season, daily δ18Op at Changsha station consistently increased with an increase in daily CPF. On a daily scale, the effect of convective activity on δ18Op was stronger than that of the “precipitation amount effect” in the cold season, as compared to the situation in the warm season. As a result, the regression line slope between δ18Op and CPF increased with increasing precipitation intensity in the warm season, meaning that as the CPF increased, the δ18Op increased at a faster rate under higher precipitation intensity. Similarly, the slope increased with increasing precipitation intensity in the cold season. This suggests that precipitation intensity and convection intensity can affect the relationship between δ18Op and CPF. Our findings shed light on how different precipitation partitions affect stable isotope composition of precipitation, thus enhancing our understanding of the variability of precipitation stable isotopes in the monsoon regions of China. Significance Statement This study aims to better elucidate the influence of different precipitation partitions on precipitation stable isotopes. In the eastern monsoon region of China, stable isotopes in precipitation showed a robust positive relationship with convective precipitation faction. On a daily scale, the convective activity enhanced the influences of the “precipitation amount effect” on precipitation stable isotopes in the warm season and reduced such influences in the cold season. These results improve our understanding of stable isotopic variability of precipitation in the eastern monsoon region, China.

A digital droplet PCR detection technique based on filter faster R-CNN

To propose a method for mitigate the impact of anomaly points (such as dust, bubbles, scratches on the chip surface, and minor indentations) in images on the results of digital droplet PCR (ddPCR) detection to achieve high-throughput, stable, and accurate detection. We propose a Filter Faster R-CNN ddPCR detection model, which employs Faster R-CNN to generate droplet prediction boxes followed by removing the anomalies within the positive droplet prediction boxes using an outlier filtering module (Filter). Using a plasmid carrying a norovirus fragment as the template, we established a ddPCR dataset for model training (2462 instances, 78.56%) and testing (672 instances, 21.44%). Ablation experiments were performed to test the effectiveness of 3 filtering branches of the Filter for anomaly removal on the validation dataset. Comparative experiments with other ddPCR droplet detection models and absolute quantification experiments of ddPCR were conducted to assess the performance of the Filter Faster R-CNN model. In low-dust and dusty environments, the Filter Faster R-CNN model achieved detection accuracies of 98.23% and 88.35% for positive droplets, respectively, with composite F1 scores reaching 99.15% and 99.14%, obviously superior to the other models. The introduction of the filtering module significantly enhanced the positive accuracy of the model in dusty environments. In the absolute quantification experiments, a regression line was plotted using the results from commercial flow cytometry equipment as the standard concentration. The results show a regression line slope of 1.0005, an intercept of -0.025, and a determination coefficient of 0.9997, indicating high consistency between the two results. The ddPCR detection technique using the Filter Faster R-CNN model provides a robust detection method for ddPCR under various environmental conditions.

Ergonomic Risk Assessment and Fatigue Analysis During Manual Lifting Tasks in Farming Activities

Introduction: Farming is a physically demanding occupation that puts farmers at risk of musculoskeletal disorders, particularly when frequently performing activities like heavy lifting, which strains the lower back muscles. The present study aimed to assess the ergonomic risk and fatigue during manual lifting tasks pertaining to farming activities. Methods: A study was performed on 20 farmers to analyze the ergonomic risks associated with load lifting through the estimation of the Recommended Weight Limit and Lifting Index using the revised NIOSH lifting equation. The low back compression forces of the participants were estimated using the 3DSSPP software. Surface electromyography was employed to analyze the onset of muscle fatigue during the lifting activity. Results: The results of the study showed a 111.12% increase in the recommended weight limit, a 52.77% reduction in lifting index, and a 28.15% reduction in the low back compression forces for the redesigned lifting technique. The average low-back compression force for the redesigned technique was observed to be well below the back compression design limit of 770 lb. A reduction in the slope of the RMS voltage regression line by 60% and a reduction of 50.23% in the peak spectral power of the sEMG signal, accompanied by a shift in the peak spectral power towards higher frequency region indicated delayed onset of fatigue for the redesigned technique. Conclusion: The outcomes of the study indicated that the ergonomic redesign of the lifting task could significantly reduce the lifting index and alleviate the spinal compression forces well within the back-compression design limit. The redesign was also found to delay the onset of fatigue in the erector spinae muscles.

Signal-to-noise of linear and volume measures of left ventricular and left atrial size

BackgroundSerial echocardiographic assessments are common in clinical cardiology, e.g., for timing of intervention in mitral and aortic regurgitation. When following patients with serial echocardiograms, each new measurement is a combination of true change and confounding noise.The current investigation compares linear chamber dimensions with volume estimates of chamber size. The aim is to assess which measure is best for serial echocardiograms, when the ideal parameter will be sensitive to change in chamber size and have minimal spurious variation (noise). We present a method that disentangles true change from noise. Linear regression of chamber size against elapsed time gives a slope, being the ability of the method to detect change. Noise is the scatter of individual points away from the trendline, measured as the standard error of the slope. The higher the signal-to-noise ratio (SNR), the more reliably a parameter will distinguish true change from noise.MethodsLV and LA parasternal dimensions and apical biplane volumes were obtained from serial clinical echocardiogram reports. Change over time was assessed as the slope of the linear regression line, and noise was assessed as the standard error of the regression slope. Signal-to-noise ratio is the slope divided by its standard error.ResultsThe median number of LV studies was 5 (4–11) for LV over a mean duration of 5.9 ± 3.0 years in 561 patients (diastole) and 386 (systole). The median number of LA studies was 5 (4–11) over a mean duration of 5.3 ± 2.0 years in 137 patients.Linear estimates of LV size had better signal-to-noise than volume estimates (p < 0.001 for diastolic and p = 0.035 for systolic). For the left atrium, the difference was not significant (p = 0.214). This may be due to sample size; the effect size was similar to that for LV systolic size. All three parameters had a numerical value of signal-to-noise that favoured linear dimensions over volumes.ConclusionLinear measures of LV size have better signal-to-noise than volume measures. There was no difference in signal-to-noise between linear and volume measures of LA size, although this may be a Type II error. The use of regression lines may be better than relying on single measurements. Linear dimensions may clarify whether changes in volumes are real or spurious.Graphical

МОДЕЛИРОВАНИЕ КИНЕТИКИ ПРОЦЕССА ПИРОЛИЗА БИОМАССЫ С УЧЕТОМ ВЛИЯНИЯ СОСТАВА СЫРЬЯ В ТРУБЧАТЫХ РЕАКТОРАХ

The pyrolysis process of plant biomass can be better understood by investigating the kinetic mechanism of the decomposition process of various components. Biomass can have different structures, thermophysical properties and chemical composition, which affects the kinetics of the pyrolysis process. (Research purpose) The research purpose is simulating and studying the kinetics of the pyrolysis process of corn cob particles, which allows to determine the rate of chemical reactions occurring during the decomposition of the material, and identifying the main factors affecting the rate and efficiency of pyrolysis. (Materials and methods) The biomass of corn cobs, which has a particle size of 0.02 square meters and has thermophysical properties, was used for analysis using Comsol multiphysics software. (Results and discussion) We have obtained models that describe temperature trends, especially the temperature in the center of biomass. It was shown that the temperature on the surface of the biomass reaches a peak of 727 Kelvin after 460 seconds; the temperature in the center of the biomass reaches 794 Kelvin after 433 seconds. It was shown that the activation energy and frequency coefficient are derived from the slope of the linear regression line and the intersection. (Conclusions) It was found that the process of pyrolysis of biomass of a corn cob particle occurred in the temperature range of 190-432 degrees Celsius; at a temperature of 190 degrees Celsius, the biomass began to lose mass, and the mass loss stopped at a temperature of 432 degrees Celsius. The kinetic parameters were calculated by the Kissinger method. The least squares method and correlation analysis were used to calculate kinetically constant parameters. It was stated that the results will be useful to optimize the process of pyrolysis of biomass. It was determined that in the Kissinger method the kinetic parameters were the same for the entire pyrolysis process; the correlation coefficient between temperature and heating rate in the model is 0.79.

Machine learning study of D:A1:A2 ternary organic solar cells

Introducing third component into donor:acceptor heterojunction provide new dimension to improve power conversion efficiency of organic solar cells (OSCs). However, the combining different donors and acceptors, as well as optimizing fabricating procedures are exhaust and tedious by experiment for ternary OSCs. Herein, we constructed the database, including 280 groups of D:A1:A2 type ternary OSCs with non-fullerene acceptors. The descriptors include the mass ratios, the root-mean-square roughness of morphology, the frontier molecular orbital energies and molecular fingerprints. Four kinds of machine learning (ML) models, including random forest (RF), extra tree regression, gradient boosted regression tree and adaptive boosting, were trained and tested. The coefficient of determination R2, Pearson's correlation coefficient r, root mean square error and mean absolute error were used to score the prediction results of ML models. The score and the slope of regression lines indicate RF model is prevail to other ML models in power conversion efficiency (PCE) prediction. Combining donors and acceptors in the constructed dataset generates 429,688 groups of D:A1:A2 type new ternary OSCs. Their photovoltaic performances were predicted with the trained RF model and screened. There are 138 groups of new ternary OSCs with the predicted PCE greater than 18.50%, and the champion predicted PCE (18.83%) corresponds to D18:AQx-18:ZH2 ternary OSC. The results of this work provide the guidance for optimizing ternary OSCs and can accelerate the development of high performance ternary OSCs.

Moisture Transport in Loose Fibrous Insulations under Steady-State Boundary Conditions.

This research aimed to compare the transport capacity of loose-fill mineral wool, cellulose fibers, and wood wool to transfer moisture under steady-state conditions. The tests were carried out in the heat flow meter apparatus, which created a constant thermal field, limiting samples of sorptive moistened materials. The thermal conductivity, stabilization time, and moisture content of the samples were measured. Based on the variation in the results, the dynamism of moisture transport in the materials was determined. Mineral wool samples showed the lowest sorption. As a result, the moisture transport in this material stopped the fastest. In the case of cellulose and wood fibers, moisture transport continued throughout the whole test procedure. It was noted that the amount of moisture transport is influenced primarily by the structure of the fibers, the moisture content, and the possible presence of air in the pores. The wetter the material, the faster the transport. The dynamism of moisture transport according to trends of thermal conductivity changes over time was analyzed. The greater the slope of the linear regression line, the greater the dynamics of change. The smallest dynamics of change were found for mineral wool, for which the measured slope was between -0.008 and -0.033. For cellulose and wood wool, the range of slope was from -0.141 to -0.210, and from -0.162 to -0.211, respectively. The results of this research may provide the basis for further work on buffering moisture in the adjacent internal layers of the frame walls.

Advanced fibrosis leads to overestimation of steatosis with quantitative ultrasound in individuals without hepatic steatosis.

The effect of hepatic fibrosis stage on quantitative ultrasound based on the attenuation coefficient (AC) for liver lipid quantification is controversial. The objective of this study was to determine how the degree of fibrosis assessed by magnetic resonance (MR) elastography affects AC based on the ultrasound-guided attenuation parameter according to the grade of hepatic steatosis, using magnetic resonance imaging (MRI)-derived proton density fat fraction (MRIderived PDFF) as the reference standard. Between February 2020 and April 2021, 982 patients with chronic liver disease who underwent AC and MRI-derived PDFF measurement as well as MR elastography were enrolled. Multiple regression was used to investigate whether AC was affected by the degree of liver stiffness. AC increased as liver stiffness progressed in 344 patients without hepatic steatosis (P=0.009). In multivariable analysis, AC was positively correlated with skin-capsule distance (P<0.001), MR elastography value (P=0.037), and MRI-derived PDFF (P<0.001) in patients without hepatic steatosis. In 52 of 982 patients (5%), the correlation between AC and MRIderived PDFF fell outside the 95% confidence interval for the regression line slope. Patients with MRI-derived PDFF lower than their AC (n=36) had higher fibrosis-4 scores, albumin-bilirubin scores, and MR elastography values than patients with MRI-derived PDFF greater than their AC (n=16; P=0.018, P=0.001, and P=0.011, respectively). AC is affected by liver fibrosis (MR elastography value ≥6.7 kPa) only in patients without hepatic steatosis (MRI-derived PDFF <5.2%). These values should be interpreted with caution in patients with advanced liver fibrosis.