Equivalent Results Research Articles

Irradiation and temperature service stability of the radioisotope thermophotovoltaic generators based general purpose heat source

Highly stable and long-life power supply systems are crucial to the success of space exploration missions. The systematic analysis of the service lives and stability of radioisotope thermophotovoltaic (RTPV) generators with general purpose heat sources (GPHSs) is the cornerstone of future practical space applications. Its operational lifetime is mainly limited by the degradation caused by the irradiation of key transducer components by the isotope source, while its operational stability is mainly related to the temperature variation of the external environment. The irradiation and temperature stability as the main influencing factors of GPHS-RTPV were studied. Results indicate that the output performance of the GPHS–RTPV was maintained at 50.15% after 1 × 1013 n/cm2 neutron and 927.84 Gy γ irradiation. The service life was conservatively estimated to be 19.883 years according to equivalent irradiation experimental results. In addition, the output performance of the GPHS–RTPV fluctuates linearly with temperature, the gradient of Pmax with temperature was −6.7 μW/K·cm2 in a range of 276.5–354.5 K, and higher output at low temperatures. This study explored the lifetime and service stability of GPHS-RTPV under actual operating conditions in space, and lays the foundation for future practical applications.

The Role of Sublobar Resection for the Surgical Treatment of Non-Small Cell Lung Cancer.

Lung cancer is the most common cancer killer in the world. The standard of care for surgical treatment of non-small cell lung cancer has been lobectomy. Recent studies have identified that sublobar resection has non-inferior survival rates compared to lobectomy, however. Sublobar resection may increase the number of patients who can tolerate surgery and reduce postoperative pulmonary decline. Sublobar resection appears to have equivalent results to surgery in patients with small, peripheral tumors and no lymph node disease. As the utilization of segmentectomy increases, there may be some centers that perform this operation more than other centers. Care must be taken to ensure that all patients have access to this modality. Future investigations should focus on examining the outcomes from segmentectomy as it is applied more widely. When employed on a broad scale, morbidity and survival rates should be monitored. As segmentectomy is performed more frequently, patients may experience improved postoperative quality of life while maintaining the same oncologic benefit.

Optimization of bioanalysis of dried blood samples

IntroductionPharmacokinetic/pharmacodynamic modelling has emerged as a valuable technique for understanding drug exposure and response relationships in drug development. Pharmacokinetic data are often obtained by taking multiple blood samples, which may disturb physiological parameters and complicate study designs. Wearable automatic blood sampling systems can improve this limitation by collecting dried blood samples at programmable time points without disrupting cardiovascular parameters. It is the objective of this study to evaluate the bioanalysis of DBS in comparison to conventional blood sampling techniques and to optimize the recovery of various compounds spiked into canine blood dried on filter paper tape. MethodsIncubated blood samples from Beagle dogs were spiked with 16 different compounds and half of the whole blood sample was centrifuged to obtain plasma. After the dried blood sample drops were dried, liquid chromatography-mass spectrometry methods were used to analyze the samples. The study explored different anticoagulants, sample preparation methods and technical approaches to best determine the compound concentrations in dried blood samples. ResultsWith the two anticoagulants tested and using the optimized sample preparation methods and technical approaches we employed, the bioanalysis of dried blood samples can provide equivalent results to conventional blood sampling techniques. DiscussionAutomated blood sampling systems have the potential to provide increased numbers of blood samples, providing substantially more Pharmacokinetic data within safety pharmacology studies without disrupting physiological parameters. They can provide a viable alternative to traditional methods of obtaining blood for various other types of studies or analyses.

Canaper: Categorical analysis of neo‐ and paleo‐endemism in R

Biodiversity has typically been quantified using species richness, but this ignores evolutionary history. Due to the increasing availability of robust phylogenies, methods have been developed that incorporate phylogenetic relationships into quantification of biodiversity. CANAPE (categorical analysis of neo‐ and paleo‐endemism) is one such method that can provide insight into the evolutionary processes generating biodiversity. The only currently available software implementing CANAPE is Biodiverse, which is written in Perl and can be used either through a graphical user interface (GUI) or user‐developed scripts. However, many researchers, particularly in the fields of ecology and evolutionary biology, use the R programming language to conduct their analyses. Here, we present canaper, a new R package (www.r‐project.org) that provides functions to conduct CANAPE in R. canaper implements methods for efficient computation, including parallelization and encoding of community data as sparse matrices. The interface is designed for maximum simplicity and reproducibility; CANAPE can be conducted with two functions, and parallel computing can be enabled with one line of code. Our case study shows that canaper produces equivalent results to Biodiverse and can complete computations on moderately sized datasets quickly (<10 min to reproduce a canonical study). canaper allows researchers to conduct all analyses from data import and cleaning through CANAPE within R, thereby obviating the need to manually import and export data and analysis results between programs. We anticipate canaper will become a part of the toolkit for analyzing biodiversity in R.

A new method based on pseudo-Zernike polynomials to analyze and extract dynamical and spectral information from the 2DIR spectra.

Ultrafast two-dimensional infrared (2DIR) spectroscopy is a relatively new methodology, which has now been widely used to study the molecular structure and dynamics of molecular processes occurring in solution. Typically, in 2DIR spectroscopy the dynamics of a system is inferred from the evolution of 2DIR spectral features over waiting times. One of the most important metrics derived from the 2DIR is the frequency-frequency correlation function (FFCF), which can be extracted using different methods, including center and nodal line slope. However, these methods struggle to correctly describe the dynamics in 2DIR spectra with multiple and overlapping transitions. Here, a new approach, utilizing pseudo-Zernike moments, is introduced to retrieve the FFCF dynamics of each spectral component from complex 2DIR spectra. The results show that this new method not only produces equivalent results to more established methodologies in simple spectra but also successfully extracts the FFCF dynamics of individual component from very congested and unresolved 2DIR spectra. In addition, this new methodology can be used to locate the individual frequency components from those complex spectra. Overall, a new methodology for analyzing the 2D spectra is presented here, which allows us to retrieve previously unattainable spectral features from the 2DIR spectra.

Performance: Differences in measuring performance

An important issue in human resources is the procedure of the employees’ performance evaluation. The appraisal is essential in the sense of employee appreciation and motivation. Most employers use a subjective performance evaluation of a single superior or a group of persons involved in the employee’s working processes. The subjective evaluation of a group or one person is often questioned about being appropriate. An often-named solution for a more objective criteria could be data driven performance measures. Professional sport provides a unique opportunity to compare objective and subjective performance evaluation measures. A data set of the German Bundesliga was used to test if the two different performance measure come to equal results. It is shown that differences in means exist but equivalence tests support the hypothesis that both measures could be treated as equal. In toto, it seems that in an environment where performance is relatively good to measure objective and subjective performance evaluations lead to equivalent results.

A method for measuring and calibrating the thickness of thin films based on infrared interference technology

Transparent thin films are critical industrial components widely used in advanced optics, microelectronics and materials science, among other relevant fields. The rapid and stable measurement of sub-micron industrial film thickness is of particular importance. In this study, a novel method based on the principles of infrared interference and laser profilometry is proposed to calculate the periodogram of the original spectrum and accurately extract the maximum frequency. In addition, a high-precision, compact and low-cost thin-film thickness measurement and calibration system is developed. This system achieves accurate measurement of single-layer film thickness and adapts to correct errors caused by slight tilt due to mechanical vibration or misalignment during film placement. Experimental data show that, compared to conventional infrared interference thickness measurement systems, the use of the proposed maximum frequency extraction algorithm improves measurement accuracy by approximately 90% and stability by approximately 70%. Furthermore, even when measuring the thickness of films with inclined components, the use of the constructed thin film thickness measurement and calibration system provides equivalent results.

A grain-by-grain comparison of apatite fission-track analysis by LA-ICP-MS and the External Detector Method

Laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is increasingly used in fission-track analysis to determine the uranium content of host mineral specimens, particularly apatite. Fission-track dating by LA-ICP-MS (LAFT) has several advantages over the conventional External Detector Method (EDM), particularly in terms of sample turn-around times and the fact that neutron irradiations and the handling of radioactive materials are no longer necessary, while providing a similar level of in-situ information about parent nuclide (238U) concentrations. In addition, it facilitates the simultaneous measurement of multiple isotopes for double or triple-dating approaches or compositional characterisation. While it is often implicitly assumed that the EDM and LAFT fission-track dating approaches produce equivalent results, this assertion has yet to be adequately tested. We present an extensive dataset of apatite fission track results from 17 samples representing a large range of fission-track ages (∼0–2 Ga), 238U concentrations (0.14–410 ppm) and thermal histories that were analysed grain-by-grain using both techniques in order to investigate whether they yield concordant results during routine fission-track analysis.Apart from a few outliers, our data show that 238U concentrations measured by the EDM and LAFT techniques yield indistinguishable results across at least three orders of magnitude when a similar calibration system against rapidly cooled standards (e.g., Durango) is used. Comparison of single grain pooled and central ages reveals that LAFT ages are within error of EDM ages for apatite fission track standards such as Fish Canyon Tuff or Durango, as well as for a range of other samples whose shorter mean confined track lengths (<13 μm) and broader track distributions indicate they experienced more complex cooling histories. The most important conclusion here is that both the conventional EDM and LAFT methods can be expected to yield identical results for the breadth of ages, 238U concentrations, and underlying thermal histories commonly found in real world apatites.Importantly, the aggregate empirical calibrations for EDM and LAFT mask an underlying assumption that the mean etchable range of fission fragments is a constant having the mean value observed for spontaneous tracks in age standards such as the Durango apatite. Given that this assumption is known to be false in the great majority of samples, it is our view that empirically derived EDM and LAFT fission-track ages are best considered as model ages and that there should be greater clarity about the assumptions involved in their calculation.

Temporal Changes in Mediterranean Pine Forest Biomass Using Synergy Models of ALOS PALSAR-Sentinel 1-Landsat 8 Sensors

Currently, climate change requires the quantification of carbon stored in forest biomass. Synthetic aperture radar (SAR) data offers a significant advantage over other remote detection measurement methods in providing structural and biomass-related information about ecosystems. This study aimed to develop non-parametric Random Forest regression models to assess the changes in the aboveground forest biomass (AGB), basal area (G), and tree density (N) of Mediterranean pine forests by integrating ALOS-PALSAR, Sentinel 1, and Landsat 8 data. Variables selected from the Random Forest models were related to NDVI and optical textural variables. For 2015, the biomass models with the highest performance integrated ALS-ALOS2-Sentinel 1-Landsat 8 data (R2 = 0.59) by following the model using ALS data (R2 = 0.56), and ALOS2-Sentinel 1-Landsat 8 (R2 = 0.50). The validation set showed that R2 values vary from 0.55 (ALOS2-Sentinel 1-Landsat 8) to 0.60 (ALS-ALOS2-Sentinel 1-Landsat 8 model) with RMSE below 20 Mg ha−1. It is noteworthy that the individual Sentinel 1 (R2 = 0.49). and Landsat 8 (R2 = 0.47) models yielded equivalent results. For 2020, the AGB model ALOS2-Sentinel 1-Landsat 8 had a performance of R2 = 0.55 (validation R2 = 0.70) and a RMSE of 9.93 Mg ha−1. For the 2015 forest structural variables, Random Forest models, including ALOS PAL-SAR 2-Sentinel 1 Landsat 8 explained between 30% and 55% of the total variance, and for the 2020 models, they explained between 25% and 55%. Maps of the forests’ structural variables were generated for 2015 and 2020 to assess the changes during this period using the ALOS PALSAR 2-Sentinel 1-Landsat 8 model. Aboveground biomass (AGB), diameter at breast height (dbh), and dominant height (Ho) maps were consistent throughout the entire study area. However, the Random Forest models underestimated higher biomass levels (&gt;100 Mg ha−1) and overestimated moderate biomass levels (30–45 Mg ha−1). The AGB change map showed values ranging from gains of 43.3 Mg ha−1 to losses of −68.8 Mg ha−1 during the study period. The integration of open-access satellite optical and SAR data can significantly enhance AGB estimates to achieve consistent and long-term monitoring of forest carbon dynamics.

Selection of Discrete Event Simulation Software for Simulating Mining Operations

Simulation is a tool that can be used to predict and evaluate the performance of mining systems. It has been used for various applications such as fleet optimization in underground mining, comparison of timing and efficiency between drills, and mine-to-mill production systems. Due to the availability of a large number of simulation tools, careful selection should be made depending on the type of problem to be simulated. The study presented in this paper aims to compare two different simulation tools, AutoMod and SimMine, by comparing the two underground loading models created. This is achieved by analysing different equipment alternatives for possible future conditions when the mine depth increases. Both tools produce statistically equivalent results for simulated production. The paper presents a discussion regarding the choice of software and based on the study, SimMine is recommended for easy, fast modelling, whereas AutoMod, with its wider palette of software features and facilities provided, is recommended for more enhanced and detailed mining simulations. The study is based on the mining operation in the Kiirunavaara underground mine in Sweden, and the simulation is conducted based on a fixed production target.

Https://universepg.com/journal-details/ejmhs/outcome-of-early-versus-delay-hip-spica-casting-for-children-with-femoral-shaft-fractures

Femoral shaft fractures are among the most prevalent fractures of the lower extremities in children. Although many approaches and options are available for their treatment, the most appropriate treatment option for school going children is still debatable. In this study 34 children with femoral fractures were recruited between Jan. 2018 and Jan 2019 at the Nangarhar university and public health Hospital. which is divided into two groups: (Group-A) immediate reduction with hip Spica consists 22 children and (Group -B) treatment consist of skin traction for 2-3 weeks precede with hip Spica casting consists 12 children and we studied gender distribution, fracture side, site and type of the fracture, also we note complications include; initial shortening, axial, sagittal and rotational alignment and hospital stay. All patients were under observation for a period of 3 months after removal of Spica cast. The study found that boys were more affected than girls, which the middle third of the femoral shaft was the most common site fracture (58.92%), that the spiral fracture was the most common type of femoral shaft fracture (43.18%), as well as that side way alignment was observed more than other kinds of complications in both treatment modalities; for immediate Spica, four children (18.18%) and three cases (25%).Conclusions: There was minimal difference between early and delayed Spica in terms of treatment complications and functional result. However, early Spica greatly reduced hospitalization time and treatment costs while producing equivalent results as delayed Spica use.

Patient-specific quality assurance strategies for synthetic computed tomography in magnetic resonance-only radiotherapy of the abdomen.

The superior tissue contrast of magnetic resonance (MR) compared to computed tomography (CT) led to an increasing interest towards MR-only radiotherapy. For the latter, the dose calculation should be performed on a synthetic CT (sCT). Patient-specific quality assurance (PSQA) methods have not been established yet and this study aimed to assess several software-based solutions. A retrospective study was performed on 20 patients treated at an MR-Linac, which were selected to evenly cover four subcategories: (i) standard, (ii) air pockets, (iii) lung and (iv) implant cases. The neural network (NN) CycleGAN was adopted to generate a reference sCT, which was then compared to four PSQA methods: (A) water override of body, (B) five tissue classes with bulk densities, (C) sCT generated by a separate NN (pix2pix) and (D) deformed CT. The evaluation of the dose endpoints demonstrated that while all methods A-D provided statistically equivalent results (p=0.05) within the 2% level for the standard cases (i), only the methods C-D guaranteed the same result over the whole cohort. The bulk densities override was shown to be a valuable method in absence of lung tissue within the beam path. The observations of this study suggested that the use of an additional sCT generated by a separate NN was an appropriate tool to perform PSQA of a sCT in an MR-only workflow at an MR-Linac. The time and dose endpoints requirements were respected, namely within 10min and 2%.

Blazar boosted dark matter — direct detection constraints on σeχ : role of energy dependent cross sections

Elastic collisions with relativistic electrons from the blazar's jet can accelerate dark matter (DM) particles in the DM spike surrounding the supermassive black hole at its center. This can allow one to set stringent limits on the DM-electron scattering cross section (σ̅eχ ) for DM masses less than 100 MeV. We consider DM particles boosted by energetic electrons in the jets of the blazars TXS 0506+056 and BL Lacertae. Both vector and scalar mediators for the scattering of electron and electrophilic fermionic DM are studied. We highlight that the ensuing energy dependence of the S-matrix for the corresponding Lorentz structure of the vertex significantly modifies the constraints. We find that the revised exclusion limits are orders of magnitude stronger than the equivalent results for the simple constant cross section assumption. Our limits are also assessed for the less cuspy spike.

Social sphere and gender issues

The article deals with the issues of gender equality based on the consideration of Russian and international norms, statistics of gender equality in the Russian Federation. The measures implemented in the Russian Federation to preserve gender equality, in particular the National Strategy of Action for Women for 2023–2030, the state programs «Development of healthcare», «Social support for citizens», «Employment», national projects «Demography», «Healthcare», «Small and medium–sized entrepreneurship» are considered and support for individual entrepreneurial initiative».The proposals for the preservation of gender equality in the Russian Federation for the long term are formulated. The development of a separate federal project is proposed, for example, as part of the state program economic development and innovative economy with indicators such as the proportion of women who have the same salary as men holding equivalent positions; the proportion of women holding managerial positions; achieving equivalent results in terms of the amount of time for household chores for men and women, including through development and accessibility of technologies that replace women’s labor. The development and adoption of the all–Russian standard of gender equality policy is also proposed. A standard can be a set of principles, rules, processes, an analysis of the current situation, and best practices for observing gender equality. The standard should have practice–oriented recommendations for the implementation of gender policy in the organization.

Python programs to apply regularized derivatives in the magnetic tilt derivative and gradient intensity data processing: A graphical procedure to choose the regularization parameter

The Tikhonov regularization parameter is a key parameter controlling the smoothness degree and oscillations of a regularized unknown solution. Usual methods to determine a proper parameter (L-curve or the discrepancy principle, for example) are not readily applicable to the evaluation of regularized derivatives, since this formulation does not make explicit a set of model parameters that are necessary to implement these methods. We develop a procedure for the determination of the regularization parameter based on the graphical construction of a characteristic “staircase” function associated with the L2-norm of the regularized derivatives for a set of trial regularization parameters. This function is independent of model parameters and presents a smooth and monotonic variation. The regularization parameters at the upper step (low values) of the ''staircase'' function provide equivalent results to the non-regularized derivative, the parameters at the lower step (high values) leading to over-smoothed derivatives. For the evaluated data sets, the proper regularization parameter is located in the slope connecting these two flat end-members of the staircase curve, thus balancing noise amplification against the amplitude loss in the transformed fields. A set of Python programs are presented to evaluate the regularization procedure in a well-known synthetic model composed of multiple (bulk and elongated) magnetic sources. This numerical approach also is applied in gridded aeromagnetic data covering high-grade metamorphic terrains of the Anápolis-Itauçu Complex in the Brasília Fold Belt central portion of Tocantins Province, central Brazil, characterized by multiple magnetic lineaments with different directions and intersections which are associated with shear zones, geologic faults, and intrusive bodies. The results obtained from the regularization procedure show efficiency in improving the maps of filtered fields, better tracking the continuity of magnetic lineaments and general geological trends. The results from the application in the Brasília Fold Belt enhance the importance and broader coverage of the Pirineus Zone of High Strain.

Efficacy comparison of an automated growth-based system and plate-count method on the detection of yeasts and molds in personal care products.

The present investigation studies the efficacy of an automated growth-based system for a quantitative determination of Candida albicans and Aspergillus brasiliensis in several personal care products. The main purpose of this validation study was to prove that the alternative method's entire performance is not inferior to the conventional pour-plate method for a quantitative determination of yeasts and molds. Thus, a performance equivalence was established in accordance with the United States Pharmacopeia <1223>. C. albicans and A. brasiliensis were pooled to use as inoculum (equivalent to 1.0x108 CFUs/mL) in the suitability of the method test. Personal care product's preservatives were chemically neutralized leading to the yeast's and mold's recovery by means of the alternative microbiological method and the pour-plate method. A correlation curve was generated for each personal care product by plotting DTs relative to the corresponding log CFU values. 30 personal care products have been tested for quantification of yeasts and molds using an alternative microbiological method. An equivalence of results were made through the construction of correlation curves that allow the establishment of numerically equivalent results between the enumeration data from the reference method and the alternative method. Thus, following the guidelines of <USP 1223>, essential validation parameters were tested, such as equivalence of results (CC > 0.95), linearity (R2 >0.9025), accuracy (% recovery >70%), operating range, precision (CV < 35%), ruggedness (ANOVA, P > 0.05), specificity, limit of detection, and limit of quantification. It was shown that all the test results obtained from the alternative method were in statistical agreement with the standard plate-count method. Thus, this new technology was found to meet all the validation criteria needed to be considered as an alternative method for yeast and mold quantification in the personal care products tested. Implementation of alternative methods can offer benefits in execution and automation while improving accuracy, sensitivity, and precision and reduce the microbiological process time compared to the traditional ones.

Review on adherence of the literature to official recommendations on albuminuria harmonization and standardization.

Albuminuria standardization is a key issue to produce reliable and equivalent results between laboratories. We investigated whether official recommendations on albuminuria harmonization are followed in the literature. The PubMed database was searched from June 1 toSeptember 26, 2021. The search terms included urine albumin, urine albumin-to-creatinine ratio (uACR), and albuminuria. A total of 159 articles were considered eligible; 50.9 % reported the type of urine collection. Specifically, 58.1 % collected a random spot urine specimen, 21 % collected a first morning void, and 6.2 % collected a 24-h specimen. Overall, 15 % of articles reported data on sample shipping, storage, and centrifugation and 13.3 % mentioned the preanalytical phase without any data on albuminuria. The method for albuminuria was properly described in 31.4 % of articles; of these, 54.9 % used immunological methods, and 8.9 % contained errors or missing data. Most articles (76.7 %) expressed test results as albuminuria-to-creatininuria ratio. Different decision levels were utilized in 130 articles; of these, 36 % used a decision level of≤30 mg/g creatininuria and 23.7 % used three decision levels (≤30, 30-300, and≥300 mg/g). The failure to follow guidelines on albuminuria harmonization was mainly found in the preanalytical phase. The poor awareness of the importance of preanalytical steps on test result may be a possible explanation.

Model uncertainties of SPT, CPT, and VS-based simplified methods for soil liquefaction assessment

Simplified methods for assessing soil liquefaction potential based on the standard penetration test (SPT) are prevalent in practice and widely accepted by several seismic design codes. When encountering sites that have not been investigated using SPT, such as offshore sites or sites with a high level of gravel content, engineers can only substitute the methods based on piezocone penetration test data (CPT-qc methods) or shear wave velocity measurements (VS-based methods); however, these two approaches perform inconsistently with methods based on SPT data (SPT-N methods). As a result, this paper exploits the datasets consisting of SPT, CPTU, and in situ seismic test measurements from 13 alluvium sites in the Taipei Basin to compare the performance of prevalent SPT-N, CPT-qc, and VS-based methods. The discrepancies (uncertainties) of these methods are characterized as Gaussian distribution models, which is believed to be a feasible strategy for predicting equivalent results for SPT-N methods when SPT data are not available. Finally, the application of the proposed models to liquefaction potential index evaluation is demonstrated using a real case study.

Shortest Paths Discovery in Uncertain Networks via Transfer Learning

Due to various reasons such as noisy measurement and privacy preservation, a network/graph is often uncertain such that each edge in the network has a probability of existence. In this paper, we study finding the most probable shortest path which has the highest probability of being the shortest path between a given pair of nodes in an uncertain network. Despite significant progress being made, this problem still suffers from the efficiency and scalability issue. To solve this problem, the state-of-the-art adopts a two-phase approach where Phase 1 generates some candidate paths and Phase 2 estimates their probabilities of being the shortest path and returns the one with the highest probability as the solution. Notably, Phase 2 requires a large number of simulations over all edges in the network and can easily dominate the cost of the whole process. In this paper, we aim to resolve the efficiency and scalability issue by optimizing Phase 2. Specifically, we first propose a non-learning based fast approximation technique which significantly reduces the number of samples for the probability estimation in each simulation. Afterwards, we further propose a learning-based method which can directly estimate the probability of each candidate path without costly simulations. Extensive experiments show that (1) compared to the state-of-the-art, our fast approximation technique and learning-based method can achieve up to 5x and 210x speedups in Phase 2 respectively while maintaining highly competitive or even equivalent results, (2) the training process is highly scalable and (3) the prediction function can work effectively under the problem settings different from the one it was trained.

Modeling sea ice albedo and transmittance measurements with a fully-coupled radiative transfer model.

A rigorous treatment of the sea ice medium has been incorporated in the advanced Coupled Ocean-Atmosphere Radiative Transfer (COART) model. The inherent optical properties (IOPs) of brine pockets and air bubbles over the 0.25-4.0 µm spectral region are parameterized as a function of the sea ice physical properties (temperature, salinity and density). We then test the performance of the upgraded COART model using three physically-based modeling approaches to simulate the spectral albedo and transmittance of sea ice, and compare them with measurements collected during the Impacts of Climate on the Ecosystems and Chemistry of the Arctic Pacific Environment (ICESCAPE) and the Surface Heat Budget of the Arctic Ocean (SHEBA) field campaigns. The observations are adequately simulated when at least three layers are used to represent bare ice, including a thin surface scattering layer (SSL), and two layers to represent ponded ice. Treating the SSL as a low-density ice layer yields better model-observation agreement than treating it as a snow-like layer. Sensitivity results indicate that air volume (which determines the ice density) has the largest impact on the simulated fluxes. The vertical profile of density drives the optical properties but available measurements are scarce. The approach where the scattering coefficient for the bubbles is inferred in lieu of density leads to essentially equivalent modeling results. For ponded ice, the albedo and transmittance in the visible are mainly determined by the optical properties of the ice underlying the water layer. Possible contamination from light-absorbing impurities, such as black carbon or ice algae, is also implemented in the model and is able to effectively reduce the albedo and transmittance in the visible spectrum to further improve the model-observation agreement.