Summation Model Research Articles

Alveolar–arterial oxygen gradient nonlinearly impacts the 28‐day mortality of patients with sepsis: Secondary data mining based on the MIMIC‐IV database

Lung is often implicated in sepsis, resulting in acute respiratory distress syndrome (ARDS). The alveolar-arterial oxygen gradient [D(A-a)O2 ] reflects lung diffusing capacity, which is usually compromised in ARDS. But whether D(A-a)O2 impacts the prognosis of patients with sepsis remains to be explored. Our study aims to investigate the association between D(A-a)O2 and 28-day mortality in patients with sepsis using a large sample, multicenter Medical Information Mart for Intensive Care (MIMIC)-IV database. We extracted a data of 35 010 patients with sepsis from the retrospective cohort MIMIC-IV database, by which the independent effects of D(A-a)O2 on 28-day death risk was investigated, with D(A-a)O2 as being the exposure variable and 28-day fatality being the outcome variable. Binary logistic regression and a two-piecewise linear model were employed to explore the relationship between D(A-a)O2 and the 28-day death risk after confounding factors were optimized including demographic indicators, Charlson comorbidity index (CCI), Sequential Organ Failure Assessment (SOFA) score, drug administration, and vital signs. A total of 18 933 patients were finally included in our analysis. The patients' average age was 66.67 ± 16.01 years, and the mortality at 28 days was 19.23% (3640/18933). Multivariate analysis demonstrated that each 10-mmHg rise of D(A-a)O2 was linked with a 3% increase in the probability of death at 28 days either in the unadjusted model or in adjustment for demographic variables (Odds ratio [OR]: 1.03, 95% CI: 1.02 to 1.03). But, each 10 mmHg increase in D(A-a)O2 was associated with a 3% increase of death (OR: 1.03, 95% CI: 1.023 to 1.033) in the case of adjustment for all covariants. Through smoothed curve fitting and generalized summation models, we found that non-linear relationship existed between D(A-a)O2 and the death at 28-day, which demonstrated that D(A-a)O2 had no any impacts on the prognosis of patients with sepsis when D(A-a)O2 was less than or equal to 300 mmHg, but once D(A-a)O2 exceeded 300 mmHg, however, every 10 mmHg elevation of D(A-a)O2 is accompanied by a 5% increase of the 28-day death (OR: 1.05; 95% CI:1.04 to 1.05, p < 0.0001). Our findings suggests that D(A-a)O2 is a valuable indicator for the management of sepsis patient, and it is recommended that D(A-a)O2 be maintained less than 300 mmHg as far as possible during sepsis process.

Development of Megaselia scalaris at constant temperatures and its significance in estimating the time of death.

Megaselia scalaris (Schmitz, 1938) (Diptera: Phoridae) is a common insect in forensic science that is frequently found in indoor cases, particularly on corpses in closed environments. Although this species is useful for estimating the minimum postmortem interval (PMImin) in the absence of Calliphoridae, there is a lack of data on its development in China. Herein, we studied the development of M. scalaris exposed to seven constant temperatures ranging from 16 to 34 °C. The mean (± SD) developmental durations of M. scalaris from egg to adult stage at 16, 19, 22, 25, 28, 31, and 34 °C were 1486.9 ± 75.3, 823.7 ± 42.8, 448.2 ± 59.8, 417.7 ± 19.7, 297.2 ± 27.3, 272.9 ± 10.4, and 253.0 ± 5.0 h, respectively. The mean (± SE) lower developmental threshold temperature (TL) and the thermal summation constant (K) were determined by a linear model as 12.69 ± 0.3 °C and 4965.8 ± 227.9-degree hours, respectively. A nonlinear model estimated the lower developmental thresholdtemperature, intrinsic optimum temperature, and upper lethal developmental threshold temperature as 14.58, 21.00, and 34.15 °C, respectively. We established three development models to estimate the age of the immature insect, namely the isomegalen diagram, isomorphen diagram, and thermal summation model. In addition, a regression analysis of the relationship between body length and total development time from hatching to pupariation was performed. Our findings provide a basis for applications of M. scalaris in PMImin estimations.

Predicting the Occurrence and Risk Damage Caused by the Two-Spotted Spider Mite Tetranychus urticae (Koch) in Dry Beans (Phaseolus vulgaris L.) Combining Rate and Heat Summation Models for Digital Decisions Support

In this work, we use developmental rate models to predict egg laying activity and succession of generations of T. urticae populations under field conditions in the Prespa lakes region in Northern Greece. Moreover, the developmental rate model predictions are related to accumulated heat summations to be compared with actual bean damage and to generate pest-specific degree-day risk thresholds. The oviposition was predicted to start at 57.7 DD, while the first peak in egg laying was estimated to be at 141.8 DD. The second and third peak in egg production were predicted to occur at 321.1 and 470.5 DD, respectively. At the degree-day risk threshold, half development of the first summer generation was estimated at 187 DD and 234 DDm while for the second, it was estimated at 505 DD and 547 DD for 2021 and 2022, respectively. According to the model predictions, no significant differences were observed in the mean generation time (total egg to adult development) of T. urticae between the two observation years (t = 0.01, df = 15, p = 0.992). The total generation time was estimated at 249.3 (±7.7) and 249.2 (±6.7), for 2021 and 2022, respectively. The current models will contribute towards predictions of the seasonal occurrence and oviposition of T. urticae to be used in pest management decision-making. Moreover, the development of population model is a prerequisite for the buildup and implementation of smart plant protection solutions.

Possible future selves in STEM: an epistemic network analysis of identity exploration in minoritized students and alumni

BackgroundSTEM minority participation programs have been widely implemented in higher education with the goal of diversifying the global STEM workforce. Informed by research highlighting the potential of targeted exploration of STEM roles and reflection on the self in relation to STEM (identity exploration), this work examines how engagement in a government funded STEM minority participation program shaped these processes in current students and program alumni.ResultsEpistemic network analysis (ENA) was used to visualize conceptual connections between identity themes that emerged from interviews with present and past program participants. Network models were developed for current students and alumni for cross-group comparisons. Differences were found in how participants at different stages of their careers enact and describe their identity exploration processes. Summative network models highlighted how students discussed action-taking (sometimes through participation in STEM minority program initiatives) as they explored less-certain possible future STEM roles, while alumni integrated more diverse and holistic facets of their identities when conceptualizing their futures. To close the interpretive loop, a qualitative interpretation of interview discourse was used to give context to network patterns.ConclusionsResults highlight the differences between novices’ and professionals’ conceptualizations of their future selves and illustrate how minoritized individuals describe their long-term patterns of identity exploration related to STEM majors and careers. Implications for future STEM identity research and practice, including higher education programming as a tool to support students’ STEM identity exploration processes, are discussed.

Temperature-Dependent Development of Nitidula rufipes (Linnaeus, 1767) (Coleoptera: Nitidulidae) and Its Significance in Estimating Minimum Postmortem Interval.

Coleoptera, including the family Nitidulidae, are valuable for estimating long-term postmortem intervals in the late stage of body decomposition. This study showed that, under seven constant temperatures of 16, 19, 22, 25, 28, 31, and 34 °C, the developmental durations of Nitidula rufipes (Linnaeus, 1767) from oviposition to eclosion were 71.0 ± 4.4, 52.9 ± 4.1, 40.1 ± 3.4, 30.1 ± 2.1, 24.2 ± 2.0, 21.0 ±2.3, and 20.8 ± 2.4 days, respectively. The morphological indexes of body length, the widths of the head capsules, and the distance between the urogomphi of the larvae were measured in vivo. The regression model between larval body length and developmental durations was simulated for larval aging, and the head capsule width and the distance between the urogomphi at different instars were cluster-analyzed for instar discrimination. Based on the developmental durations, larval body length and thermal summation data were obtained, and the isomorphen diagram, isomegalen diagram, linear thermal summation models, and curvilinear Optim SSI models were established. The lower developmental threshold and thermal summation constant of N. rufipes evaluated by the linear thermal summation models were 9.65 ± 0.62 °C and 471.40 ± 25.46 degree days, respectively. The lower developmental thresholds, intrinsic optimum temperature, and upper lethal developmental threshold obtained by Optim SSI models were 10.12, 24.15, and 36.00 °C, respectively. The study of the immature stages of N. rufipes can provide preliminary basic developmental data for the estimation of minimum postmortem interval (PMImin). However, more extensive studies are needed on the effects of constant and fluctuating temperatures on the development of N. rufipes.

Frictional heat induced morphological responses at the interface in rotary friction welding of austenitic alloys: corona-bond and heat-pattern

Frictional heat induced morphological responses of austenitic alloys SUS304, A286, and Inconel 718 at the interface in rotary friction welding was focused in this study, addressing initiation, evolution of corona-bond and the formation of heat-pattern. Summative models that describe the location and width of corona-bond at initiation, the corona-bond evolution mode and the formation of heat-patterns were given. The results show that when the corona-bond initiates at 0.33 R ∼ R, it fills the interface to form a lens-shaped heat-pattern. Inside this morphology, recrystallized ultrafine grains are formed to provide a superior performance. When the corona-bond initiates at 0–0.33 R with a width >0.4 R, it spreads to periphery to form a straight-line-shaped heat-pattern. Inside this heat-pattern, deformed grains and sub-boundaries are formed. The tensile strength of straight-line heat-pattern is lower than that of lens-shaped heat-pattern. When the corona-bond initiates at 0–0.33 R with a width ≤0.4 R, it does not spread but concentrates itself at center to form a spindle-shaped heat-pattern consisted of a ‘spindle body’ at center and a ‘friction line’ at periphery. Spindle body corresponds to a region made up of equiaxed recrystallized ultrafine grains, whereas the friction line corresponds to recrystallized grains and substructured grains. The formation of the friction line makes neglectable effect on local the strength but it does lower the elongation, where the local elongation of the friction line decreases to 6%–9% compared to 18% of a spindle body.

Initial laboratory validation of temperature development models for Necrodes littoralis L. (Staphylinidae: Silphinae)

Development models of necrophagous insects are applied in forensic entomology for post-mortem interval estimation. Such estimates may be used as scientific evidence in legal investigations. For this reason, it is important that the models are valid and that the expert witness is aware of their limitations. Necrodes littoralis L. (Staphylinidae: Silphinae) is a necrophagous beetle species that frequently colonizes human cadavers. Temperature models of development for the Central European population of these beetles were recently published. In this article, we present results of the laboratory validation study for these models. Errors of beetle age estimation differed significantly between the models. Thermal summation models yielded the most accurate estimates, and the isomegalen diagram least accurate estimates. Errors of the beetle age estimation varied across beetle developmental stages and rearing temperatures. In general, most development models of N. littoralis were satisfactorily accurate in estimating beetle age under laboratory conditions; therefore, the study provides initial evidence to support their validity in forensic cases.

Neurons in Primate Area MSTd Signal Eye Movement Direction Inferred from Dynamic Perspective Cues in Optic Flow.

Smooth eye movements are common during natural viewing; we frequently rotate our eyes to track moving objects or to maintain fixation on an object during self-movement. Reliable information about smooth eye movements is crucial to various neural computations, such as estimating heading from optic flow or judging depth from motion parallax. While it is well established that extraretinal signals (e.g., efference copies of motor commands) carry critical information about eye velocity, the rotational optic flow field produced by eye rotations also carries valuable information. Although previous work has shown that dynamic perspective cues in optic flow can be used in computations that require estimates of eye velocity, it has remained unclear where and how the brain processes these visual cues and how they are integrated with extraretinal signals regarding eye rotation. We examined how neurons in the dorsal region of the medial superior temporal area (MSTd) of two male rhesus monkeys represent the direction of smooth pursuit eye movements based on both visual cues (dynamic perspective) and extraretinal signals. We find that most MSTd neurons have matched preferences for the direction of eye rotation based on visual and extraretinal signals. Moreover, neural responses to combinations of these signals are well predicted by a weighted linear summation model. These findings demonstrate a neural substrate for representing the velocity of smooth eye movements based on rotational optic flow and establish area MSTd as a key node for integrating visual and extraretinal signals into a more generalized representation of smooth eye movements.SIGNIFICANCE STATEMENT We frequently rotate our eyes to smoothly track objects of interest during self-motion. Information about eye velocity is crucial for a variety of computations performed by the brain, including depth perception and heading perception. Traditionally, information about eye rotation has been thought to arise mainly from extraretinal signals, such as efference copies of motor commands. Previous work shows that eye velocity can also be inferred from rotational optic flow that accompanies smooth eye movements, but the neural origins of these visual signals about eye rotation have remained unknown. We demonstrate that macaque neurons signal the direction of smooth eye rotation based on visual signals, and that they integrate both visual and extraretinal signals regarding eye rotation in a congruent fashion.

Origin of the Reactor Antineutrino Anomalies in Light of a New Summation Model with Parametrized β^{-} Transitions.

We investigate the possible origins of the reactor antineutrino anomalies in norm and shape within the framework of a summation model where β^{-} transitions are simulated by a phenomenological model of Gamow-Teller decay strength. The general trends of divergence from the Huber-Mueller model on the antineutrino side can be reproduced in both norm and shape. From the exact electron-antineutrino correspondence of the summation model, we predict similar distortions in the electron spectra, suggesting that biases on the reference spectra of fission electrons could be the cause of the anomalies.

Analysis of Educational Policy in the Framework of Learning Efficiency and Effectiveness

This study aims to reveal how the policy-making process carried out by SMPS-IT and SMAS-IT Muslimah Sejati Bekasi, starting from the formulation, and implementation, to policy evaluation, which will end in the value of effectiveness and efficiency as a form of institution existence. This study uses qualitative research through descriptive analysis methods with data collection models using interviews, documentation, observations, and triangulation of sources, techniques, and theories. Through this method, researchers get a finding containing policy cases from two institutions related to the similarities and differences between the formulation process and effectiveness and efficiency. In the formulation process, both have different policies between online and offline, but in the formulation, each has weaknesses consisting of flaws in analysis and alternatives. Meanwhile, in terms of implementation, there are obstacles, individually and institutionally, composed of weak motivation and the disintegration of some teachers and staff. The evaluation has similarities in the implementation system, namely, using a formative, summative model. In terms of effectiveness and efficiency, both achieved the same value. Namely, they were both able to graduate students of 30 Juz Qur'an, while inefficiency there were shortcomings in financing and dependence on electricity in the teaching and learning process.

Study of the influence of technological parameters on the mechanics of shaping of billets using roll stamping processes

The article presents the results of development and research of technological schemes of planting flanges on tubular (ring) workpieces by stamping by rolling cylindrical and conical rolls. It is shown that the achievement of significant dimensions of the various elements of the workpiece is possible by providing a directed flow of metal by changing the relative position of the roll and the workpiece. Planting of external flanges is one of the most effective operations of stamping by rolling, as it allows you to form a wide range of products with advanced geometric elements. To assess the technological capabilities of the flange landing operation, the most dangerous from the destruction positions of the workpiece zone was identified and the analysis of the stress strain state of the material using the method of grids, hardness measurement and microstructural analysis. According to the results of the research, the ways of deformation of the particles of the material of the peripheral surface of the flange in the coordinates "intensity of deformations - an indicator of the stress state" are schematically constructed. These deformation paths are given against the background of curves of ultimate deformations of steels, which are built on the results of uniaxial compression and torsion of cylindrical specimens and using tested approximations. A mathematical model of deformation trajectories is constructed, for which a one-parameter function is taken as a basis, which is "glued" from the elementary function of the sine and tangent to it at some point in the line. To determine the used plasticity resource, a damage summation model with a power approximation of the damage function was adopted. As a result, we have for the first time described the general expression of the linear damage summation model for the case of the parametric deformation path problem. The graphical representation on the constructed model of accumulation of damages in material of a dangerous zone of a flange at landing by a method of rolling stamping (SHO) is resulted. Based on the constructed model, it is possible to model the accumulation of damage by changing the values of the model parameters for different materials and deformation paths, which, in turn, depend on the relative geometric parameters of the workpiece and its location relative to the rolling roll.

Summative Evaluation of ICT-Based Learning Media

Prospective teacher students have been heavily involved in developing ICT-based learning media. Various forms of media have been produced, such as multimedia, hypermedia, web, video, animation, or presentation. Until now, not all media developed have undergone a summative evaluation but only arrived at a formative evaluation. One of the reasons is the lack of references. This study aims to formulate a summative evaluation model of ICT-based learning media developed by prospective teacher students using quantitative and qualitative descriptive approaches. The study began with observations of student research reports to examine the summative evaluation model used. The information is then discussed in a focus group discussion involving relevant experts and practitioners. The study found that the summative evaluation of ICT-based learning media could be done through a quasi-experimental survey or case study. Quasi-experimental methods that can be applied are nonequivalent control group design, factorial design, counterbalanced design, and time series design. The format was obtained mainly considering limited time, a place for testing, and opportunities to be involved in the class. Either quasi-experiments, surveys, or case studies can be carried out by students in collaboration with relevant teachers when students do teaching practicum at school and then mature when students do research.

Reshaping the EFL Formative Assessment Pedagogy With Blockchain Technology

Blockchain technology is a distributed database with features such as no forgery, full traceability, openness, and transparency which is superior in establishing trust mechanisms and brings new opportunities for finance, healthcare, technology, and education. As a required course of all universities in China, College English has a large demographic covering millions of students. But the traditional EFL summative assessment model fails to fully reflect the L2 learner&amp;rsquo;s learning process and increment performance. The current paper focuses on the novel applications of blockchain in the educational domain and how blockchain technology reshapes the EFL Formative Assessment framework in the consensus mechanism to achieve a decentralized and highly trusted learning process record and evaluation. This innovative approach aims at improving the openness, transparency, and fairness of the EFL learning process by recording and monitoring the teachers&amp;rsquo; and students&amp;rsquo; behaviors. The research findings of this paper provide preliminary exploration for L2 evaluation and supply some inspiration to policymakers, EFL practitioners, and technology developers about the potential usages of digital credentials anchored on blockchains.

Developing multivariate models for predicting the level of dissatisfaction due to a specific metro noise masked with four specific water sounds

Incorporating pleasant sounds into traffic noises is an important design strategy to optimize noise perception. However, as the previous studies based on the auditory masking method mainly focused on road traffic or aircraft noises, there is a lack of research on alleviating the negative perceptions due to metro noise by adding other sounds. Accordingly, this study analyzed the regulation mechanisms of four specific water sounds (fountain, stream, water-drop and waterfall sounds) on the dissatisfaction due to a specific metro noise and established the multivariate models to predict the dissatisfaction level due to combined metro-water sounds. Seventy-nine subjects participated in the experiment and were exposed to a series of acoustic samples before being asked to cast their negative perception votes. The results suggested that the dissatisfaction with metro noise could be improved by adding the four types of water sounds, among which the capability of water-drop sound was the strongest, followed by the fountain and stream sounds, and the waterfall sound was the least effective. Besides, in order to reduce the dissatisfaction level at the global sound pressure levels (SPLs) of 60 and 65dBA, the SPL of metro noise should be no more than 3 dBA higher than that of water sound, and a water signal-to-noise ratio (WSNR) of 6 dBA was most desirable. Furthermore, among the considered models (energy summation model, independent effects model and energy difference model), the independent effects model, which fitted the dissatisfaction level data moderately, yielded the relatively highest coefficients of determination after one relevant acoustic factor (WSNR Threshold) and personality traits (gender and sensitivity) were added. It is worth noting that a single metro noise and a single sample for each type of water sound were selected and their combined sounds were studied, thus, this study could be considered as a preliminary work and the results and applicability have limitations.

Manajemen Pembelajaran Daring Program Tahfizh Al-Qur’an Pada Masa Kenormalan Baru Di Al-Wafi Islamic Boarding School

This study aims to determine the management of courageous learning in the tahfizh Al-Qur'an program at Al-Wafi Islamic Boarding School in the new normal. The research was conducted with a case study approach. Collecting data by interview, observation and documentation. Data processing with reduction, displaying data and drawing conclusions. The results showed: (1) learning planning in the form of preparing halaqah tahfizh groups, schedules, methods and learning media. Implementation of learning, combining classical learning with ZOOM and individual learning with WhatsApp. In addition, it is also equipped with learning supervision using Google Sheets. The learning evaluation consists of evaluating the learning process by evaluating and evaluating learning outcomes using a summative evaluation model through semester exams and evaluation through juz incremental exams. (2) Second, the effectiveness of the learning process is seen from two things, first, it is boldly not more effective because it is influenced by students' motivation, students' honesty, parental support at home, teacher competence and adequate facilities. Second, learning applications, WhatsApp and ZOOM Cloud Meeting have high effectiveness and are even the best applications according to their functions. In the Google Spreadsheet application, it is used as an alternative as a tool to create a form of learning tahfizh Al-Qur'an.

Impacts of formative evaluation model towards improving students’ learning outcomes in online teaching platforms

Education is one of the areas that was affected by the Covid-19 pandemic. In the current situation, lecturers must have the ability to use the appropriate approach in the teaching and learning process. The majority of universities have used online teaching platforms in the teaching and learning process. However, Lecturers have many obstacles in the learning process. One of them is that the lecturer does not know the online-based evaluation platforms. This situation has decreased students’ knowledge. Therefore, innovation of the learning evaluation model is imperative to development. This study discusses the impacts of the Formative Evaluation Model (FEM) in improving students' learning outcomes. FEM is applied in KULINO as a Learning Management System (LMS). A total of 120 students and 2 lecturers were involved in this research. Using two learning approaches; one group used the summative evaluation model while the latter group used the FEM evaluation model. Questionnaires about students’ perceptions were distributed before and after the experimental learning process. There were differences in the mean scores between pre and post-test. The mean score of students’ attitude increased by 6.74 points and students’ knowledge mean score increased by 2.23 points.&#x0D; &#x0D; Keywords- Education, Formative evaluation model, Learning management system

Application of integrated species distribution models in parasitic diseases prevention and control: a review

Species distribution model, a mathematical model theoretically based on the temporal and spatial locations of species in the ecosystem and their associations with other species, is useful to display the current species distribution and predict the future species distribution, which has been widely applied in ecology, biogeography and spatial transmission of infectious diseases. Integrated species distribution model is a comprehensive, summative and reliable combination model that simultaneously uses multiple species distribution models or integrates multiple data sources for modeling. This review describes the theory and classification of species distribution models, and summarizes the creation and verification of integrated species distribution models and their applications in parasitic disease prevention and control. During the practical applications of integrated species distribution models, the study scale, niche matching, big data utilization, combination of multidisciplinary methods and knowledge background and ecological implications should be emphasized.

EVALUATION OF DEFORMABILITY OF MATERIAL DURING PLANTING OF ELEMENTS OF PREPARATIONS BY ROLLING STAMPING METHOD

The article presents the results of development and research of technological schemes of planting flanges on tubular (ring) workpieces by stamping by rolling cylindrical and conical rolls. It is shown that the achievement of significant dimensions of the various elements of the workpiece is possible by providing a directed flow of metal by changing the relative position of the roll and the workpiece. Planting of external flanges is one of the most effective operations of stamping by rolling, as it allows you to form a wide range of products with advanced geometric elements. To assess the technological capabilities of the flange landing operation, the most dangerous from the destruction positions of the workpiece zone was identified and the analysis of the stress-strain state of the material using the method of grids, hardness measurement and microstructural analysis. According to the results of the research, the ways of deformation of the particles of the material of the peripheral surface of the flange in the coordinates "intensity of deformations - an indicator of the stress state" are schematically constructed. These deformation paths are given against the background of curves of ultimate deformations of steels, which are built on the results of uniaxial compression and torsion of cylindrical specimens and using tested approximations. A mathematical model of deformation trajectories is constructed, for which a one-parameter function is taken as a basis, which is "glued" from the elementary function of the sine and tangent to it at some point in the line. To determine the used plasticity resource, a damage summation model with a power approximation of the damage function was adopted. As a result, we have for the first time described the general expression of the linear damage summation model for the case of the parametric deformation path problem. The graphical representation on the constructed model of accumulation of damages in material of a dangerous zone of a flange at landing by a method of SHO is resulted. Based on the constructed model, it is possible to model the accumulation of damage by changing the values of the model parameters for different materials and deformation paths, which, in turn, depend on the relative geometric parameters of the workpiece and its location relative to the rolling roll.

Primary aerosol emissions from lignocellulosic biomass and major constituents under well-defined pyrolysis conditions

Near-source aerosol emissions from biomass burning are challenging to model and predict because of the complexity of the feedstocks and the evolved species, as well as the potential variability in local conditions. This study investigated and characterized near-source emissions from biomass and biomass constituent pyrolysis under well-defined conditions, providing data for validation of aerosol formation models and sub-models, and tested a hypothesis that near-source aerosol emissions from biomass can be predicted through a summative model approach based on constituent emissions and lignocellulosic biomass composition. Aerosol emission factors, concentrations, sizes, and volatility were assessed during highly repeatable lignocellulosic biomass and constituent pyrolysis experiments using a macro-TGA. Lignin and cellulose were found to produce significantly more and larger pyrolysis aerosol emissions than hemicellulose, and lignin produced aerosols with lower volatility than those from hemicellulose and cellulose. Lignocellulosic composition was investigated for its influence on primary aerosol emissions from biomass pyrolysis, including contributions to aerosol quantity, size, and volatility, through two approaches. First, the superposition model was tested using experimental aerosol measurements from individual constituents. Second, a simulated pine sample was produced by mixing constituents in the proportions in which they are present in pine, and aerosol emissions from pyrolysis of this sample were experimentally measured. Simulated aerosol emissions from superposition modeling and mixed-constituent-derived “pine” were compared to elucidate synergistic constituent influences on aerosol formation, and both results were found to predict pinewood aerosol emissions well. Conclusions regarding the successes and failures of the superposition model in predicting primary biomass aerosol emissions under similar conditions were drawn. Lastly, the influence of combustion on the biomass aerosol emissions under the conditions studied in this work was characterized to highlight the applicability and limitations of the pyrolysis results presented in this work to near-source aerosols formed under oxidative conditions.

THE ROLE OF A PRINCIPAL IN DEVELOPING THE PROFESSIONALITY OF TEACHERS AT SMP NEGERI 10 IN TANJUNGBALAI

&lt;p&gt;This study aims to describe the planning, supervision, role, and actions of a school principal in developing teacher professionalism at SMP Negeri 10 in Tanjung Balai. This research follows qualitative research methods, and the triangulation technique is used to obtain the data through observation, interviews, and document studies. The results of this study indicate that the planning carried out by the principal is to create criteria for the acceptance of new staff, to create a teacher work program per quarter, and to save school funds. The supervision carried out is formative and summative model supervision, which is carried out periodically every week in the classroom by paying attention to the way the teacher teaches. Extrinsic motivation carried out by school principals in motivating their teachers is by praising the teachers, being respectful to teachers, listening to teacher complaints, following up on teacher complaints, and providing training in the IT field. Meanwhile, the intrinsic motivation is that when teachers cannot attend the training, the teachers can learn from their colleagues so that the teacher can continue to improve their abilities.&lt;/p&gt;