Average Formula Research Articles

Bremsstrahlung radiation power in fusion plasmas revisited: towards accurate analytical fitting

Abstract In fusion plasmas, where electron temperatures $T_e$ range from keV to hundreds of keV, Bremsstrahlung radiation constitutes a significant energy loss mechanism. While various thermal average fitting formulas exist in the literature, their accuracy is limited, particularly for $T_e \leq 20$ keV with error $>10\%$. Additionally, non-relativistic fitting formulas become invalid for $T_e \geq 50$ keV. The accurate calculation of Bremsstrahlung radiation is important for fusion gain study, especially of advanced fuels fusion. In this work, we develop new but still simple fitting formulas that are valid for electron temperatures ranging from small ($\lesssim0.1$ keV) to extreme relativistic range, with errors of less than 1\% even for high atomic number ions (e.g., $Z=30$), which could be sufficient for fusion plasma applications. Both electron-ion (e-i) and electron-electron (e-e) Bremsstrahlung radiations are considered. Both polynomial fitting with truncated ($t=k_BT_e/m_ec^2\leq10$) and one-fit-all formulas are provided. Additionally, we offer fitting formulas for e-i and e-e specifically for electron energies, which could prove useful in non-Maxwellian Bremsstrahlung radiation studies.

Deactivation mechanism of catalyst in long-period experiment of 1,1,2-TCE dehydrochlorination

ABSTRACT VDC, as an important raw material for high barrier material PVDC and lithium-ion battery binder PVDF, had an increasing demand. The catalytic dehydrochlorination of 1,1,2-TCE to generate VDC was a green process route that was expected to replace the heavily polluting sodium hydroxide saponification process in industry. There was a certain research foundation for the catalytic dehydrochlorination of 1,1,2-TCE, among which the core problem was that the catalyst was prone to deactivation. Previous studies had calculated the average molecular structure of the spent catalyst surface species when coconut shell activated carbon was used as the support. In subsequent studies, alumina support had been proven to be a better carrier for dehydrochlorination of 1,1,2-TCE, and the selected catalyst had been used in long-period laboratory experiments. The results indicated that the catalyst life had been significantly improved. In the early stage of the reaction, the activity of the catalyst decreased rapidly. In the first 20 h, the conversion of 1,1,2-TCE decreased from 49.35% to 40.36%. From 21 h to 120 h, the conversion of 1,1,2-TCE decreased from 39.96% to 36.18%, tending to stabilize. After 120 h of reaction, the catalyst was extracted and elemental analysis, FTIR, and GPC characterization were performed on the spent catalyst surface species. The average molecular formula of the carbon deposits was obtained as C96.08H50.29Cl36.53. Compared with coconut shell activated carbon support, under the action of activated alumina support, the route of catalyst carbon deposition had changed, and the sediment was more composed of polyvinylidene chloride components. Under certain conditions, sediment formed a dynamic equilibrium, which explained why the activity of the catalyst gradually stabilized. This study revealed the catalytic mechanism of active alumina supported catalyst and the pathway of carbon deposits generation, which was of great significance for improving the lifespan of improved catalyst.

Development of E-Based Learning Modules Problem Based Learning (PBL) in improving students' critical thinking abilities

This research aims to determine the feasibility of problem-based learning (PBL) e-Modules in improving students' critical thinking skills. The research carried out is a type of R&D (Research and Development) research that follows the 4D development model. This research was carried out at the Al-Ikhlas Taliwang Islamic Boarding School for class XI students. This research will last for three months, starting from December to February 2023/2024. Determination of the sample in this research was carried out using purposive sampling technique. The number of samples in this study was 26 students from class XI. Data collection techniques in this research are observation, interviews, documentation and questionnaires. The research instrument consists of a material expert validity test questionnaire, a media expert validity test questionnaire, and an e-module readability test questionnaire by students. The data analysis technique uses the average percentage score formula from the validation results of material experts and media experts, and the results of e-module readability tests by students. From the results of the material expert validation, a score of 3.3 was obtained from validator 1 and 3.6 from validator 2, an average score of 3.45 with good criteria. Then the media expert validation results obtained a score of 3.5 from validator 1 and 3.4 from validator 2 with an average score of 3.45 with good criteria. Based on the results of the e-module readability test assessment by students, it shows that the results of the class . So it can be said that the e-module that is being developed is practical for use in learning.

Proof of 5D An AGT conjecture at β = 1

In this paper, we give a proof of 5D An AGT conjecture at β = 1, where the gauge theory side is one dimension higher than the original 4D case, and corresponds to the q-deformation of the 2D conformal field theory side. We define a q-deformed An Selberg integral, which generalizes the An Selberg integral and the q-deformed A1 Selberg integral in the literature. A q-deformed An Selberg average formula with n + 1 Schur polynomials is proposed and proved to complete the proof.

Pengaruh Model Pembelajaran Collaborative Learning terhadap Motivasi Belajar PAK Siswa Kelas VII SMP Negeri 1 Sipoholon Tahun Pembelajaran 2023/2024

The aim of this research is to determine the differences in student learning motivation in PAK learning before and after it is taught using the Collaborative Learning learning model for class VII students at SMP Negeri 1 Sipoholon for the 2023/2024 academic year. The research hypothesis is: "There is a difference in students' learning motivation in PAK learning before and after learning with the Collaborative Learning learning model for Class VII Students of SMP Negeri 1 Sipoholon for the 2023/2024 Learning Year." The population is all class VII students of SMP Negeri 1 Sipoholon, totaling 163 people. The research sample was determined using the Purposive Sampling technique, namely 32 students in class VII-3 as the experimental class which used a collaborative learning model and 32 students in class VII-4 as the control class which used normal treatment (conventional class). This research method is the Quasi Experimental Design method using a Nonequivalent Control Group Design. The instrument used in this research was a 22 item questionnaire. Research data for the questionnaire was analyzed using the average difference test formula (N-Gain Score). It was found that the average value for the experimental class was 0.7283 in the high category. And the average value for the control class is 0.1548, which is in the low category. Then carrying out an independent test using the t test obtained a value of t = 11.648 > t table (α = 0.05; df = 62) = 2,000. Based on the research results, it is stated that Ha is accepted and H0 is rejected. Thus, it can be concluded that there are differences in students' learning motivation in PAK learning before and after being taught using the Collaborative Learning learning model.

Pengaruh Model Pembelajaran Reciprocal Teaching terhadap Keaktifan Belajar Peserta Didik Pendidikan Agama Kristen dan Budi Pekerti Kelas VIII SMP Negeri 2 Pollung Tahun Pembelajaran 2023/2024

The aim of this research is to find out whether there is a difference in the learning activity of students who use the reciprocal teaching model compared to conventional ones in class VIII Christian Religious Education and Character education at SMP Negeri 2 Pollung for the 2023/2024 academic year. The research hypothesis is: "The Reciprocal Teaching Model has a positive and significant effect on the Learning Activeness of Christian Religious Education and Character Education Students in Class VIII of SMP Negeri 2 Pollung for the 2023/2024 Academic Year." The population is all students who are Protestant Christians in Class VIII of SMP Negeri 2 Pollung which consists of 6 classes totaling 180 students. The research sample was determined using the Purposive Sampling technique, namely 30 students in class VIII5 as the experimental class which used the reciprocal teaching model and 30 students in class VIII4 as the control class which used ordinary treatment (conventional class). This research method is the Quasi Experimental Design method using a Nonequivalent Control Design. The instrument used in this research was a test with 30 items. Research data for the questionnaire was analyzed using the average difference test formula (N-Gain Score). It was found that the average value for the experimental class was 0.6370 in the medium category, while the average value for the control class was 0.2531. in the low category so it is known that increasing the Learning Activeness of Class VIII Christian Religious Education and Character Education students at SMP Negeri 2 Pollung for the 2023/2024 academic year is more effective using the Reciprocal Teaching model than using conventional treatment. Then carrying out an independent test using the t test obtained a value of t = 7.040 > t table (α = 0.05; df = 58) = 2,000. Thus, it can be concluded that the research hypothesis is accepted, namely that there is a difference in the learning activity of students before and after learning with the Reciprocal Teaching Model in Learning Christian Religious Education and Character Education for Class VIII SMP Negeri 2 Pollung for the 2023/2024 Academic Year and H0 is rejected.

Development of average run length formulas for EWMA control chart under the AR(1) with quadratic trend model for detecting and monitoring process variability

Development of average run length formulas for EWMA control chart under the AR(1) with quadratic trend model for detecting and monitoring process variability

Pengaruh Metode Demonstrasi terhadap Minat Belajar Pendidikan Agama Kristen dan Budi Pekerti Peserta Didik Kelas VII SMP Negeri 4 Siborongborong Tahun Pembelajaran 2023/2024

The aim of this research is to determine the influence of students' interest in learning using the demonstration method. The research hypothesis is: "There is a difference in students' interest in learning in class VIII SMP N 4 Siborongborong for the 2023/2024 academic year before and after learning using the demonstration method. The population is all class VIII of SMP Negeri 4 Siborongborong, North Tapanuli Regency for the 2023/2024 academic year with 206 Protestant Christians consisting of 7 classes. The research sample was determined using the Purposive Sampling technique, namely 35 students in class VIII 3 as the experimental class using the demonstration method and class VIII 5 totaling 35 students as the control class using ordinary treatment (conventional class). This research method is the Quasy Experimental Design method using a Nonequivalent Control Group Design. The instrument used in this research was a 30-item questionnaire. Research data for the questionnaire was analyzed using the average difference test formula (N-Gain Score). It was found that the average value for the experimental class was 0.7454 in the high category. And the average value for the control class is 0.1481, which is in the low category. Then carrying out an independent test using the t test obtained a value of t = 15.168 > t table (α = 0.05; df = 68) = 2,000. Thus, it can be concluded that the research hypothesis is accepted, namely that there is a difference in students' interest in learning in class VIII of SMP N 4 Siborongborong for the 2023/2024 academic year before and after learning using the demonstration method.

Chemical composition and molecular structure of asphaltene in Azerbaijani crude oil: A case study of the Zagli field

The lack of information about the chemical composition and structure of asphaltenes in crude oil, which has a sufficient share in the economy of Azerbaijan, complicates its processing and use. As a first attempt, this research is devoted to the detailed analysis of the average molecular structure and properties of asphaltenes isolated from crude oil samples collected from the Zaglı oil field using the integrated application of high-sensitivity devices such as Nuclear Magnetic Resonance (NMR), Ultraviolet–Visible (UV–Vis), Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction analysis, Elemental analysis, Scanning Electron Microscope (SEM), Differential Thermal Analysis (DTA), Dynamic Light Scattering (DLS). The average molecular formula of asphaltene monomer was determined to be C49.5H55O3.04N0.95S2. An island architecture with one polycyclic aromatic hydrocarbon (PAH) in each molecule of this compound is predominant. Amorphous asphaltene molecule contains vanadium-based porphyrins, –COOH group, disulfide (−S-S-) linkage. It was found that asphaltene of crude oil is stable up to 406 °C. The three-stage pyrolysis process in the temperature range of 406–818 °C resulted in the formation of 12.58 % coke. Due to the absence of free radicals in the range of 25–100 ℃, the asphaltene sample is dielectric. The decrease of monodispersity with particle growth in asphaltene compound in different solvents was analyzed by dynamic and static light scattering. The HOMO-LUMO energy gap of the asphaltene molecule was 2.666 eV, indicating high stability. The knowledge gained about the chemical composition and molecular structure of asphaltenes can help prevent problems arising in oil production and refining processes.

Uji Coba Pembuatan Limbah Whey Dangke Menjadi Olahan Sorbet

Whey dangke is a waste generated by proses of separation whey and curd during process of making dangke. This study aims to determine whey of dangke used as dairy product, such as sorbetacceptance of the community to taste, aroma, color and texture of milk sorbet from processed whey dangke Enrekang. Population in this research is student of class 4 Polytechnic of Bosowa. The sample in this research is 73 panelists using simple random sampling technique. This type of research is experimental. The analysis in this study is descriptive statistics using the average formula. whey dangke in this experiment researcher use three types of treatment that is at first treatment W100:S0 (100% whey dangke and 0% pure milk), second treatment W75: S25 (75% whey dangke and 25% pure milk ), the third treatment of W50:S50 (50% whey dangke and 50% pure milk). The results showed that whey dangke Enrekang can be processed as sorbet. Hedonic test on milk sorbet product showed that the most preferred taste aspect was the W50:S50 treatment with an average of 3.46%, the most preferred treatment of the texture aspect was the W50: S50 treatment with an average of 3.75 , the most preferred treatment of the color aspect was the W50: S50 treatment with an average of 3.40, and the most preferred treatment of the aroma aspect was the W100:S0 treatment with an average value of 3.77.

Kobellite homologues from the Boliden Au–Cu–(As) deposit, Sweden: jigsaw patterning via nanoscale intergrowths in chessboard structures

Abstract Sulfosalt assemblages in a specimen from the Boliden Au–Cu–(As) deposit in northern Sweden, comprise micrometre to nanometre scale intergrowths of Se-rich izoklakeite and tintinaite with average formulae and calculated homologue number (N) given as: (Cu1.88Fe0.18)2.06(Pb22.92Ag1.47Cd0.01Zn0.01)24.41(Sb13.12Bi8.69)21.8(S50.19Se6.43Te0.12)56.73,N = 3.83, and (Cu1.31Fe0.74)2.05(Pb10.58Ag0.18Cd0.05Zn0.02)10.83(Sb10.2Bi5.23)15.43(S32.22Se2.46)34.7, N = 2.05, respectively. Tintinaite coexists with (Bi, Se)-rich jamesonite. High-angle annular dark field scanning transmission electron microscopy (HAADF STEM) imaging reveals chessboard structures comprising PbS and SnS modules with the number of atoms in the octahedral (M) sites counted as: n1 = 18 and n2 = 8 for tintinaite and n1 = 30 and n2 = 16 for izoklakeite. The homologue number can be calculated using the formula: N = (n1/6)–1 and N = n2/4 for PbS and SnS modules giving NTti = 2 and NIz = 4. A new N = 3 homologue, defined by n = 12 and n = 24 SnS and PbS modules, respectively, is identified as single or double units within areas with intergrowths between kobellite and izoklakeite. HAADF STEM imaging also reveals features attributable to lone electron pair micelles within the Sb-rich kobellite homologues. Atomic-resolution EDS STEM chemical mapping of Pb–Bi–Sb-sulfosalts shows a correlation with crystal structural modularity. The maps also highlight sites in the SnS modules of tintinaite in which Sb > Bi. Coherent nanoscale intergrowths between tintinaite and izoklakeite define jigsaw patterns evolving from chessboard structures and are considered to have formed during co-crystallisation of the two phases. Displacement textures and crosscutting veinlets (a few nm in width) are interpreted as evidence for superimposed syn-metamorphic deformation and are associated with the redistribution of Bi and Se. Imaging and mapping using HAADF STEM techniques is well suited to characterisation of Pb–Sb–Bi-sulfosalt phases, offering largely untapped potential to unravel the evolution of chessboard structures with applications across mineralogy but also extending into allied fields.

Penerapan Model Pembelajaran Berbasis Proyek Pada Mata Pelajaran Seni Budaya Untuk Meningkatkan Minat Dan Kreativitas Siswa Kelas IVA UPT SPF SD Inpres Tamamaung IV Kota Makassar

The main problem in this research is in learning activities where based on observations that have been made it was found that problems exist in class IVA, namely that there are still some students who have a lack of interest in learning and their level of creativity is also lacking because the teacher still uses conventional methods. So the author decided to conduct research in this class to make improvements using a project-based learning model. This research aims to determine the application of the project-based learning model to increase the interest and creativity of class IVA UPT SPF SD Inpres Tamamaung IV students, Makassar City. This type of research is Classroom Action Research (PTK) which includes four stages, namely planning, implementation, observation and reflection. The subjects of this research were 22 students in class IVA UPT SPF SD Inpres Tamamaung IV, Makassar City. This research instrument uses teacher activity observation sheets, student interest observation sheets and student creativity observation sheets. Then this data is analyzed using the average formula. From the results of this research, the average results of observation of teacher activities in cycle I were 56% (Poor) with an increase in cycle II of 90% (Very Good). The results of observing student interest in the first cycle were 69% (fairly good) and increased in the second cycle by 89% (very good). Meanwhile, student creativity also increased, in cycle I with a percentage of 74.43% (Medium Creativity) and experienced an increase in cycle II with a percentage of 80.10% (High creativity). Thus, the project-based learning model can increase student interest and creativity in Arts and Culture subjects. with material on Simple Comics and Making Curtains from Used Materials in class IVA UPT SPF SD Inpres Tamamaung IV Makassar City.

Peningkatan Aktivitas dan Hasil Belajar Melalui Picture And Picture Tematik IIID SDN 77 Kota Bengkulu

This study aims to increase the activity and student learning outcomes in thematic learning through the picture and picture learning model in class IIID SDN 77 Bengkulu City. This research is a Classroom Action Research (CAR). The subjects in this study were class IIID students at SDN 77 Bengkulu City for the 2023/2024 academic year. The number of students in class IIID, a total of 48 students with details of 29 male students and 19 female students. Data collection techniques using observation sheet techniques and test sheets. The data analysis technique used on the observation sheet, namely the average value formula and for learning outcomes uses the average value formula and the percentage of completeness of classical learning. The results showed that there was an increase in activity and student learning outcomes in Thematic learning. It was seen in cycle I that the average value of teacher activity was 26.5, increasing in cycle II with an average value of 34. In cycle I student activity the average value was 27.5 increased in the second cycle with an average value of 34. In the first cycle student learning outcomes of Indonesian language content with an average value of 70.31 with a percentage of 66.66% with a total of 32 students have a complete score. It increased in cycle II with an average score of 77.60 with a percentage of 85.41% with a total of 43 students having a complete score. In the SBdP cycle I learning content with an average score of 74.47 with a percentage of 79.16% with a total of 38 students having a complete score. It increased in cycle II with an average score of 80.20 with a percentage of 89.58% with a total of 43 students having a complete score. It can be concluded that through the picture and picture learning model can increase student learning activities and results in thematic learning class IIID SDN 77 Bengkulu City.

Predictability of Existing IOL Formulas After Cataract Surgery in Patients with a Previous History of Radial Keratotomy: A Retrospective Cohort Study and Literature Review.

This study aims to evaluate the accuracy of 12 different intraocular lens (IOL) power calculation formulas for post-radial keratotomy (RK) eyes. The investigation utilizes recent advances in topography/tomography devices and artificial intelligence (AI)-based calculators, comparing the results to those reported in current literature to assess the efficacy and predictability of IOL calculations for this patient group. In this retrospective study, 37 eyes from 24 individuals with a history of RK who underwent cataract surgery at Hoopes Vision Center were analyzed. Biometry and corneal topography measurements were taken preoperatively. Subjective refraction was obtained 6 months postoperatively. Twelve different IOL power calculations were used, including the American Society of Cataract and Refractive Surgery (ASCRS) post-RK online formula, and the Barrett True K, Double K modified-Holladay 1, Haigis-L, Panacea, Camellin-Calossi, Emmetropia Verifying Optical (EVO) 2.0, Kane, and Prediction Enhanced by Artificial Intelligence and output Linearization-Debellemanière, Gatinel, and Saad (PEARL-DGS) formulas. Outcome measures included median absolute error (MedAE), mean absolute error (MAE), arithmetic mean error (AME), and percentage of eyes achieving refractive prediction errors (RPE) within ± 0.50 D, ± 0.75 D, and ± 1 D for each formula. A search of the literature was also performed by two independent reviewers based on relevant formulas. Overall, the best performing IOL power calculations were the Camellin-Calossi (MedAE = 0.515 D), the ASCRS average (MedAE = 0.535 D), and the EVO (MedAE = 0.545 D) and Kane (MedAE = 0.555 D) AI-based formulas. The EVO and Kane formulas along with the ASCRS calculation performed similarly, with 48.65% of eyes scoring within ± 0.50 D of the target range, while the Equivalent Keratometry Reading (EKR) 65 Holladay formula achieved the greatest percentage of eyes scoring within ± 0.25 D of the target range (35.14%). Additionally, the EVO 2.0 formula achieved 64.86% of eyes scoring within the ± 0.75 D RPE category, while the Kane formula achieved 75.68% of eyes scoring within the ± 1 D RPE category. There was no significant difference in MAE between the established and newer generation formulas (P > 0.05). The Panacea formula consistently underperformed when compared to the ASCRS average and other high-performing formulas (P < 0.05). This study demonstrates the potential of AI-based IOL calculation formulas, such as EVO 2.0 and Kane, for improving the accuracy of IOL power calculation in post-RK eyes undergoing cataract surgery. Established calculations, such as the ASCRS and Barrett True K formula, remain effective options, while under-utilized formulas, like the EKR65 and Camellin-Calossi formulas, show promise, emphasizing the need for further research and larger studies to validate and enhance IOL power calculation for this patient group.

Optimizing Frame Techniques in 2-Dimensional Video Models in a Learning Perspective

As competition for talent increases, electronic media are often used to convey information and influence students' points of view. Animated films are an electronic media that can be used to bridge learning to make it more interesting and provide a new environmental feel for students. According to research results conducted by Computer Technology Research (CRT), people only remember 20% of what they see and 30% of what they hear. Yet people remember 50% of what they see and hear and 80% of what they see, hear and do at the same time. This research aims to evaluate students' level of interest and enthusiasm for learning history through animation media. The research method was created using two-dimensional (2D) animation techniques using frame by frame animation techniques. The data obtained is the result of research from interviews, observations, literature studies and questionnaires conducted at SDN 3 Kutasari which is located in Banyumas Regency. The results of the questionnaire testing used a Likert scale and the average formula for the results of the calculation was 87.9%, so it was included in the agree category or worthy of being shown as a 2D animated short film.

Means of Numbers with Fixed Hamming Weight

Summary We compute a formula for the statistical average of numbers whose base two expression has no more than a given number of digits and contains a given number of ones. We call the collection of such numbers a Hamming circle centered at 0 and conjecture a formula for the mean of Hamming circles centers at any positive integer.

Calculation Method of the Phase Recovery of Gas Cap Reservoir with Bottom Water

In gas cap reservoirs underlain by bottom water, the connection between the reservoir and the aquifer leads to an increasing invasion of bottom water as reservoir development progresses. The average formation pressure of the reservoir will change, and the separated phase recovery of the gas cap reservoir with bottom water will be affected by the change in the average formation pressure. The traditional average formation pressure calculation formulas do not consider the water influx, so the accurate calculation of separated recovery cannot be obtained by those calculation methods. The development of gas cap reservoirs with bottom water presents several challenges, including the simultaneous production of oil and gas, undetermined rates of bottom water influx, and uncertain formation pressure and gas-to-oil ratios. These factors contribute to substantial discrepancies between theoretical calculations and actual observations. A more accurate and comprehensive approach is required to address these issues and enable a precise determination of the phase separated recovery in gas cap reservoirs with bottom water. The volume-deficit method is integrated with the Fetkovich quasi-steady state method for water influx. The water-influx prediction is incorporated into the material balance equation, which is further refined by introducing the Fetkovich model to enhance the estimation of the average formation pressure. The average formation pressure, once determined, is utilized in conjunction with the established relationships among this pressure, surface oil production, gas production, and the dissolved gas–oil ratio. Through the application of mass conservation principles, the varying degree of phase recovery, as influenced by fluctuations in the average formation pressure, is calculated. The precision of this refined method has been validated by a comparison with outcomes generated by simulation software. The results reveal a commendable accuracy: an error in the average formation pressure calculation is found to be merely 2.61%, while the errors in recovery degrees for gas cap gas, dissolved gas, and oil-rim oil are recorded at 2.73%, 2.94%, and 1.28%, respectively. These minor discrepancies indicate a good level of consistency and affirm the reliability of this advanced methodology, as demonstrated by passive assessments. This paper provides a method to accurately calculate the phase recovery without some oil- and gas-production data, which provides accurate data support for the actual production evaluation and subsequent development measures.

Persepsi Guru tentang Pelayanan Tenaga Administrasi Sekolah di SMK Negeri Kota Payakumbuh

This study aims to analyze the service data of School Administration Personnel seen from the aspects of 1) ease of getting services, 2) certainty of service time, 3) accuracy/accuracy, 4) friendliness, 5) responsibilities carried out at SMK Negeri Kota Payakumbuh. This type of research is descriptive research. This research was conducted at SMK Negeri Kota Payakumbuh with a population of all teachers totaling 454 teachers with a sample of 84 teachers. The trial was conducted by 20 teachers outside the sample. To determine the sample size using the Slovin formula with an error rate of 10% with the Proportional Random Sampling technique. The research instrument uses the Likert Scale model with five alternative answers. Validity test using questionnaire and reliability using SPSS (Statistic Package and Social Science) 24.0 for windows program. The validity test of this study used a product moment with a significant level of 5% (0.444) with a reliability test using the Alpha Cronbach formula. The collected data is processed using the average formula (mean). The results of the data analysis showed that the service of School Administration Personnel in terms of: 1) ease of getting services obtained a score of 4.37 (good), 2) certainty of service time obtained a score of 4.43 (good), 3) accuracy/accuracy obtained a score of 4.41 (good) and 4) friendliness obtained a score of 4.31 5) responsibility obtained a score of 4.34 (good). It can be concluded that the service of School Administration Personnel at SMK Negeri Kota Payakumbuh obtained an average score of 4.37 in the good category.

The z‐Average of Cross‐Linked Polymers

AbstractStockmayer's formula for the weight average of cross‐linked primary chains is extended to the z‐average degree of polymerization . This average is a function of the weight‐ and z‐average degree of polymerization λw and λz of the primary chain distribution and the branching density α: . Higher averages of branched polymers from monomers of type and with functionalities f ⩾ 2 are discussed.

Investigating Load Calculation for Broken Ice and Cylindrical Structures Using the Discrete Element Method

Ice loads are critical forces that impact the structural integrity of offshore equipment in high-latitude sea areas and play a pivotal role in the design of structures in ice-prone regions. The primary objective of this study is to investigate both experimental and numerical approaches to analyze ice loads on marine structures, elucidate their characteristics and patterns, and offer technical support for the design of structures in ice-prone areas. To achieve this goal, an ice model was built using polypropylene material, and experiments were conducted in a wave flume at room temperature to measure the ice resistance on cylindrical structures. Structural loads were assessed at various ice velocities while maintaining a fixed ice concentration. Furthermore, a high-performance discrete element technology was employed to develop a numerical simulation method for calculating ice resistance on cylindrical structures. Sensitivity analysis was conducted to evaluate the influence of discrete element density on the resistance outcomes. The predicted structural resistance for ice velocities corresponding to the experimental conditions was compared with the results obtained from the model experiment. The research findings indicate that the primary cause of ice resistance is the interaction between the structure and fragmented ice, which leads to collisions, friction, rotation, and local ice accumulation. To quantify the resistance, ice resistance coefficients were defined using an average resistance formula, representing different statistical values. These coefficients were found to remain relatively constant at varying sailing speeds. The results obtained through the discrete element method for ice resistance demonstrated a remarkable agreement with the experimental findings, both in terms of observed phenomena and numerical values. This agreement serves as evidence substantiating the effectiveness of the numerical approach. These methods offer efficient and accurate load prediction solutions for the design of structures in cold regions.