Additional Methods Research Articles

Highly sensitive single-molecule detection of macromolecule ion beams.

The analysis of proteins in the gas phase benefits from detectors that exhibit high efficiency and precise spatial resolution. Although modern secondary electron multipliers already address numerous analytical requirements, additional methods are desired for macromolecules at energies lower than currently used in post-acceleration detection. Previous studies have proven the sensitivity of superconducting detectors to high-energy particles in time-of-flight mass spectrometry. Here, we demonstrate that superconducting nanowire detectors are exceptionally well suited for quadrupole mass spectrometry and exhibit an outstanding quantum yield at low-impact energies. At energies as low as 100 eV, the sensitivity of these detectors surpasses conventional ion detectors by three orders of magnitude, and they offer the possibility to discriminate molecules by their impact energy and charge. We demonstrate three developments with these compact and sensitive devices, the recording of 2D ion beam profiles, photochemistry experiments in the gas phase, and advanced cryogenic electronics to pave the way toward highly integrated detectors.

Causal effects of circulating lipids and lipid-lowering drugs on the risk of urinary stones: a Mendelian randomization study.

Previous studies have yielded conflicting findings regarding the association between circulating lipids and lipid-lowering drugs with urinary stones, and the causal relationship between the two remains inconclusive. This study aimed to assess the causal relationship between circulating lipids (Triglycerides [TG], low-density lipoprotein cholesterol [LDL-C], high-density lipoprotein cholesterol [HDL-C], apolipoprotein A [APOA], apolipoprotein B [APOB] and Pure hypercholesterolaemia), lipid-lowering drugs (HMGCR [HMG-CoA reductase] inhibitors and PCSK9[Proprotein Convertase Subtilisin/Kexin Type 9] inhibitors) and the risk of urinary stones, using genetic data. Genetic instrumental variables (GIVs) for circulating lipids and lipid-lowering drugs were obtained from the UK Biobank and existing literature. Outcome data were extracted from a genetic association database with 3,625 urinary stone cases and 459,308 controls. Two-sample MR analysis, employing the TwoSampleMR software package in R 4.2.3, was conducted to assess the associations between multiple exposures. The primary outcome was determined using the inverse variance weighted (IVW) method for the causal relationship between exposure and outcome, while additional methods such as MR-Egger, weighted median, simple mode, and weighted mode were utilized as supplementary analyses. Robustness of the Mendelian Randomization (MR) analysis results was assessed through leave-one-out analysis and funnel plots. The MR analysis revealed a significant association between elevated TG levels per 1 standard deviation and the occurrence of urinary stones (odds ratio [OR]: 1.002, 95% confidence interval [CI]: 1.000-1.003, P = 0.010). However, no significant association was observed between factors other than TG exposure and the risk of urinary stone occurrence across all methods(LDL-C: [OR], 1.001; 95% [CI], 1.000-1.003, P=0.132;HDL-C: [OR], 0.999; 95% [CI], 0.998-1.000, P=0.151;APOA:[OR] being 1.000 (95% [CI], 0.999-1.001, P=0.721;APOB: [OR] of 1.001 (95% [CI], 1.000-1.002, P=0.058;Pure hypercholesterolaemia: [OR] of 1.015 (95% [CI], 0.976-1.055, P=0.455) and lipid-lowering drugs (HMGCR inhibitors: [OR], 0.997; 95% [CI], 0.990-1.003, P=0.301 and PCSK9 inhibitors:[OR], 1.002; 95% [CI], 1.000-1.005, P=0.099). Our findings provide conclusive evidence supporting a causal relationship between an increased risk of urinary stones and elevated serum TG levels. However, we did not find a significant association between urinary stone occurrence and the levels of LDL-C, HDL-C, APOA, APOB, Pure hypercholesterolaemia and lipid-lowering drugs.

Application of the Simple Additive Weighting Method in the Assessment Process of Air Pollution on the Campus of the Silesian University of Technology

Abstract The article presents the measurement results of the concentration of dust PM10 and PM2.5 as well as SO2, NO, NO2 and NOx based on a mobile laboratory located on the campus of the Silesian University of Technology (Poland, Gliwice, Konarskiego 20B, 50.292934N, 18.682164E), in the so-called “winter period” in 2020 (from 01/01/2020 to 31/03/2020 and from 01/10/2020 to 31/12/2020). The obtained results were used to carry out a synthetic (aggregated) assessment of the threat to the anthropogenic environment, the so-called “objects”, i.e. days on which the measurements were made, interpreted as points in the multidimensional space with coordinates corresponding to the measurement results of the concentration of dust pollutants: PM10 and PM2.5 and gaseous pollutants: SO2, NO, NO2 and NOx. The determined synthetic values additionally allowed for ordering (creating rankings) of the examined “objects” in terms of air quality. For the calculations, the Simple Additive Weighting method (SAW) was used, which belongs to the group of single-criteria synthesis methods.

Diet of the North American river otter (Lontra canadensis) in North Carolina using 2 methods

AbstractRiver otters (Lontra canadensis) are key predators in North Carolina's aquatic systems, but they are often seen as competitors by anglers and fish hatcheries. River otter diets typically consist of fish and crayfish, but also include occasional herpetofauna, mammals, and birds. While standard diet studies focus on identification of prey through manual examination of stomach contents and feces, metabarcoding DNA analysis has become more popular to determine the presence or frequency of species that are often missed, misidentified, or underestimated. We collected river otter carcasses from licensed trappers and fur dealers across North Carolina from the 2009–10 trapping season through the 2015–16 season. We conducted necropsies and analyzed the stomach contents using standard observational methods and metabarcoding DNA analysis. We manually examined 522 river otter stomachs, of which 377 contained prey items. Decapods (crustaceans) were identified in 41% of stomachs and made up similar percentages within each Furbearer Management Unit (FMU). The order Perciformes composed the majority (62%) of fish prey across all stomach samples. Coastal Plain river otters primarily consumed crustaceans (50%) and fish (40%). Piedmont and Mountain river otters consumed fish (32% and 42%, respectively) most often followed by crustaceans (62% and 50%, respectively). Prey selection was similar between the sexes. Out of 368 samples, metabarcoding DNA examination was able to reliably match 164 prey items to species, 5 classes, 18 orders, 25 families, and 42 genera. Fishes made up 33% of the identifications, particularly Perciformes (13%), Cypriniformes (7%), and Siluriformes (5%). Twelve percent of identifications was made up by Amphibia, split evenly by Anura and Urodela. No birds or reptiles were detected in the Mountain or Piedmont FMUs, and no mammals were detected in the Coastal Plain or Mountain FMU. Overall, river otters in North Carolina consume a large variety of prey that varied regionally. The manual examination provided identifications that were not provided by the DNA examination (i.e., crayfish, brown snakes), while the DNA examination provided a more accurate identification of the broad array of prey items. To understand the composition of annual river otter diets we encourage managers to expand research to evaluate river otter diets year‐round and incorporate additional noninvasive methods (e.g., scat surveys) throughout the year.

Reliability Investigations in Printed Electronic Assemblies

Aerosol-Jet Printing (AJP) technology is a popular additive manufacturing method for achieving complex net geometry with micron-level accuracy. This opens up new possibilities in fabrication of electronic assemblies in 3D curvilinear form factors. Therefore, it is vital to understand not only the performance of AJP printed electronics, but also their reliability under different kinds of life-cycle operational and environmental stresses. Electrochemical migration (ECM) under temperature-humidity-bias (THB) conditions can lead to dendritic growth, which can cause dielectric breakdown, leakage current, and unexpected short circuit. ECM propensity and life prediction models for THB conditions were studied for AJP printed coupons based on silver-nanoparticle (AgNP) inks. Cyclic thermo-mechanical fatigue was studied under accelerated temperature cycling testing and modeling. Failures were found to occur mostly at interconnect transition regions due to stress concentrations caused by sudden transitions in local architecture. Drop/Shock failures for extreme accelerations were studied using a high-G drop tower. Deformations were characterized using high-speed photography and transient finite element modeling was used to study high strain-rate failures. Acknowledgments: Jason Fleischer from the Laboratory for Physical Sciences, Harvey Tseng and Jian Yu from the Army Research Lab

SMART 3D Manufacturing of Printed Electronics

Printed electronics has been around for many years, reaching back to screen printing of thick film hybrid microelectronics. As time went on new material technologies emerged and integrated with graphically based printing processes like gravure, ink jet and others. Additionally, 3d printing matured over time, again with new material technologies and printing processes to include fused deposition modeling (FDM). Born out of the desire to print engineering models the technology has evolved into the ability to print higher performance structures as the final product. The idea in creating a factory in a box for 3D printed electronics was enabled in creating the ability to print multimaterial with multiple printed processes that included additive and subtractive methods. This integration allowed for the ability to print electronics and the electronic packaging in the same system. The goal was the ability to achieve the green -button, meaning load a digital file, press the green button and the electronic device, module or product emerged. True digital to physical manufacturing. Missing in this process is the integration of machine learning, artificial intelligence and in situ monitoring of processes and materials and digital twin. This presentation will cover the industry evolution of SMART 3D Manufacturing of electronic products the enable distributed manufacturing at the point of use/need.

Validation of powder layering simulation via packing density measurement for laser-based powder bed fusion

Powder bed fusion using a laser beam (PBF-LB/M) is considered one of the most versatile additive manufacturing methods as the parts printed have high resolution thanks to the low layer thickness used. The powder packing density (PD) of the powder layer has a significant impact on the density, surface roughness and other mechanical properties of the built parts. Due to the difficulty of characterizing the powder bed in situ, simulation has often been used to study the powder behavior on the powder bed. However, in order for the simulation to have practical value, there must be some way of confirming the results via experimental methods, also called validation. The aim of this study was to develop a powder packing density-based validation method for a powder bed simulation. The developed method featured a simplistic “open cup” style sample which traps powder inside for PD measurement. The samples were built with an EOS M 290 PBF-LB/M system using Alloy 718 (also known as “IN718” or “Inconel”) powder. Average PD over the five built samples was 52.4 %, with a standard deviation of 0.2 %. The method was used to successfully validate a powder bed simulation with four recoated powder layers, modelled using FLOW-3D DEM simulation software from Flow Science Inc. Similar methods for PD characterization were found in literature, but in many cases the method does not fully correspond to the conditions of a simulated powder bed, the scale is very small, or the reliability of the PD measurement is not confirmed. The method presented in this study corresponds to typical powder bed simulation conditions, while retaining high reliability and repeatability of results.

Optimized Inconel 718 pressure vessel manufactured with laser powder bed fusion

Laser powder bed fusion (L-PBF) is one of the most novel additive manufacturing methods used for a wide range of industrial grade metallic materials. The process can produce end-use metal parts with desirable qualities and mechanical properties. L-PBF however, remains a complicated and expensive manufacturing method. Design for additive manufacturing (DfAM) is a key aspect leveraging the uptake of advantages and possibilities offered by AM in augmenting its competitiveness against conventional manufacturing (CM) methods. Inconel 718 (IN718) is a nickel-based superalloy boasting high temperature strength, good oxidation, and corrosion resistance at elevated temperatures. IN718 is commonly used for high performance applications, such as power and process industry parts, and gas turbine components. High inherent toughness, hardness, work hardening, and low thermal conductivity properties make the material difficult to manufacture through conventional machining methods. The layer-by-layer building of powder metals via L-PBF makes it possible to build different geometrical intricacy. The offered manufacturing flexibility for complex high-end metal structures for variety of applications makes L-PBF an alternative manufacturing method for high performance metals. This study investigates use of DfAM for a small-scale pressure vessel with predefined geometry, dimensions, design space and load condition. The aim is to introduce and exploit contemporary design optimization methods and their feasibility with AM. Structures, such as lattices and stress field driven geometries based on finite element analysis are investigated in this study. The designs are virtually tested under predefined pressure load of 50 bar. All four design options are manufactured on EOS M290 and IN718 powder. The result of the study shows the different optimizations decrease weight and improve material savings without compromising the linear load capacity. Optimized designs could also be made in such a way that it does not increase the manufacturing duration or add additional steps to it.

Cytoarchitectonic and connection stripes in the dysgranular insular cortex in the macaque monkey.

The insula has been classically divided into broad granular, dysgranular, and agranular architectonic sectors. We previously proposed a novel partition, dividing each sector into four to seven sharply delimited architectonic areas, with the dysgranular areas being possibly further subdivided into subtle horizontal partitions or "stripes." In architectonics, discrete subparcellations are prone to subjective variability and need being supported with additional neuroanatomical methods. Here, using a secondary analysis of indirect connectional data in the rhesus macaque monkey, we examined the spatial relationship between the dysgranular architectonic stripes and tract-tracing labeling patterns produced in the insula with injections of neuronal tracers in other cortical regions. The injections consistently produced sharply delimited patches of anterograde and/or retrograde labeling, which formed stripes across consecutive coronal sections of the insula. While the overall pattern of labeling on individual coronal sections varied with the injection site, the boundaries of the patches consistently coincided with architectonic boundaries on an adjacent cyto- (Nissl) and/or myelo- (Gallyas) architectonic section. This overlap supports the existence of a fine dysgranular stripe-like partition of the primate insula, with possibly major implications for interoceptive processing in primates including humans. The modular organization of the insula could underlie a serial stream of integration from a dorsal primary interoceptive cortex toward progressively more ventral egocentric "self-agency" and allocentric "social" dysgranular processing units.

Reconstruction of the early ethnic history of the Yakut tribe "Jarkhan" on the basis of ethnonymy, oral tradition and totemic ideas

The article is devoted to the early history of the Yakut tribe "Jarkhan", which was one of the main ethnic components involved in the formation of the Vilyui group of Yakuts. Previously, historical and genealogical information was transmitted orally with help of historical legends. The end of the XIX – the middle of the XX centuries marks a qualitatively new period in the formation of the written tradition of the genealogy of the Yakut people associated with the painstaking source studies, collecting and research work of G.V. Ksenofontov, S.I. Bolo, A.A. Savvin, G.U. Ergis, etc. We have made an attempt to show the process of segmentation of the Jarkhan clans and the formation of new tribal groups by compiling a nomenclature of the generic composition. The study of the generic composition allows us to imagine the processes of movement and settlement of genera, renaming, merging and formation of new ones. The purpose and objectives of the research are to systematize and interpret the materials of the oral genealogical tradition, legends and archival documents. The methodological basis of the research is based on the basic principles of historical science - the principle of historicism and the principle of objectivity. The principle of historicism is important for conducting genealogical research, as it allows us to trace the segmentation of large tribal groups into small ones. General scientific and historical methods (historical-comparative, historical-typological, source analysis) were used as additional research methods. The novelty of the research lies in the systematization of the tribal composition and the introduction into scientific circulation of previously unpublished documents of the National Archive of the RS(Ya) revealing the tribal composition. Based on the studied material, it is concluded that oral historical traditions and pedigrees represented the central core in the structure of historical knowledge among the Yakuts. Conceptually, genealogical traditions were formed from real genealogy and unreal, which is basically a structure-forming fictional genealogy (within the boundaries of tribal communities). The result of the work performed is the preparation of the nomenclature of the Yakut generic composition. We also found that the Yakuts had common, group and individual totems. Along with this, the practice of changing the historical totem to a new one associated with a new habitat has been revealed.

The Influence of the Levels and Addition Methods of Zinc on Stimulating some Enzymes to Resist Salinity

A field experiment was conducted in Haditha city – Anbar governorate in winter season of 2021-2022, in a loamy texture soil to study the influence of levels and addition methods of Zinc to stimulate some enzymes for increasing the tolerance of wheat crop to salinity. The experiment was designed with randomized complete blocky design with split plots (R. C. B. D), by three replicates included included the experiment included soaking the seeds before planting with zinc in three levels of zinc, the first level (0) which represents the comparison treatment (soaking with water only) and the second level (75) which represents the soaking of the seeds with zinc at a concentration (75 mg Zn kg−1) while the third level included the soaking of the seeds with zinc With a concentration of (150 mg Zn kg−1) for eight hours, then the plant was sprayed with the same concentrations above in two batches, the first at the branching stage and the second was at the plant booting stage.The statistical analysis results showed that Zn addition (seed soaking and foliar spraying), led to reduction of harmful effects of saline stress, as well as increasing Zn concentration in soil, wheat straw, roots, 1000 grain weight m, grains yield and activity of antioxidants enzymes (POD and CAT). The best results have achieved by using the level 150 mg kg−1 Zn with seed soaking and with foliar Zn spraying on plant together and that reduce the effects of saline stress in plant.

Equilibrium, kinetic and thermodynamic studies for the purification of wastewater from Congo red using simple and low cost adsorbents

AbstractThis manuscript reports the purification of wastewater from Congo red (CR) by adsorbing it on sawdust of Pinus walichiana (PW) and Populus ciliata (PC) used as adsorbents. The adsorbents were characterized by Field emission scanning electron microscopy (FESEM), Energy dispersive X‐rays (EDX) spectroscopy, X‐rays diffraction (XRD) and BET surface area and pore size analysis. Different adsorption models like Langmuir, Temkin, Freundlich and Dubinin‐Radushkevich (R‐D) were applied to the system. The adsorption of CR on sawdust of both plants followed Freundlich adsorption isotherm to greater extent than Langmuir and Temkin isotherms which means that the surface of adsorbents was mostly heterogeneous and there occurred adsorbate‐adsorbate interaction which influenced the adsorption process. The process also obeyed D‐R model and mean free energy of adsorption was calculated to be 7.11 kJ.mol‐1 showing that the process of adsorption was physical. Adsorption of CR on both adsorbents followed film diffusion, particle diffusion, pseudo first order and Elovich models. It means that the process of adsorption was mixed diffusional in nature, occurred through physical process, the sites for adsorption increased exponentially with adsorption and multimolecular layer was formed on the surface of adsorbents. ∆H was 3.77 kJ.mol‐1 and 15.92 kJ.mol‐1, ∆S was 19.49 kJ.mol‐1 and 85.91 kJ.mol‐1 while ∆G was (‐1.75 to ‐2.33) kJ.mol‐1 and (‐8.39 to 10.97) kJ.mol‐1 for PW and PC, respectively. It means that the adsorption process was endodermic, resulted in increase in entropy and spontaneous for both the adsorbents. Isoelectric point (IEP) was determined by salt addition method, and it was found to be 6.9 for sawdust of PW and 5.1 for PC. The process of adsorption was found to be higher in the low pH range for both the adsorbents.

Exploring fibre addition methods and mechanical properties of fibre-reinforced 3D printed concrete: A review

3D Concrete Printing (3DCP) is a growing field of sustainable technology that offers an avenue for rapid industrialisation of the construction industry. Over the years, many non-structural elements have been fabricated by 3D printing, thus demonstrating significant advantages over traditional casting process, including freedom from the need of mold, realisation of complex geometries and reduction of material use etc. However, examples of 3D printed structural parts are still limited with addition of fibres into concrete mixes. The fibres can be incorporated in 3D printed concrete either before mixing or printing; or during the printing. The present study adopted systematic review methodology to recommend effective fibre addition method in terms of mechanical properties of the printed concrete composite. In this review work, an attempt has been made to summarise the effect of different fibres including their type, dosage, entrainment methods, while highlighting the technical challenges and approaches adopted in the past for increasing the fibre dosages, controlling their distribution and orientation. This may save a significant amount of time and resources for the industrial sector for 3D printing high strength fibre reinforced concrete structures.

Calibration in machine learning uncertainty quantification: Beyond consistency to target adaptivity

Reliable uncertainty quantification (UQ) in machine learning (ML) regression tasks is becoming the focus of many studies in materials and chemical science. It is now well understood that average calibration is insufficient, and most studies implement additional methods for testing the conditional calibration with respect to uncertainty, i.e., consistency. Consistency is assessed mostly by so-called reliability diagrams. There exists, however, another way beyond average calibration, which is conditional calibration with respect to input features, i.e., adaptivity. In practice, adaptivity is the main concern of the final users of the ML-UQ method, seeking the reliability of predictions and uncertainties for any point in the feature space. This article aims to show that consistency and adaptivity are complementary validation targets and that good consistency does not imply good adaptivity. An integrated validation framework is proposed and illustrated with a representative example.

Recommendation System for Mobile Applications Tour Guide and Travel Services using Demographic Filtering and Content-Based Filtering Methods based on Android

This research aims to build a tourism service recommendation system by providing recommendations for tour guides and tourism destinations using machine learning recommendation system methods. The recommendation system method in this research uses the demographic filtering method to recommend tour guides using a model with three stages, namely filtering, scoring and sorting the tour guide data category. At the scoring stage, it is carried out using a decision-making system method using the Simple Additive Weighting method to weight the tour guide value with the weighting value of each criterion in the tour guide data. This research also applies a content-based filtering method using a model with two stages, namely training and recommendation. The training stage uses tf-idf weighting and the recommendation stage uses cosine similarity to recommend tourism spots based on the similarity of metadata for each item. In using the recommendation system, the data will focus on collecting tour guide data and data on tourist attractions selected by the user. This data will be processed by a recommendation system using demographic filtering and content-based filtering methods. Through the Simple Additive Weighting method in demographic filtering and tf-idf weighting with consistent similarity in content-based filtering, this research found personalized recommendation results so that the level of accuracy of the recommendation results becomes more personal and accurate. The results of this research provide a recommendation system for tourist guides and tourist attractions which is implemented into an Android-based mobile application that can be used to meet tourists' needs.

Extended study: experience of using rehabilitation magnetotherapy in patients with melanoma receiving immunotherapy

Immunotherapy is becoming an increasingly popular cancer treatment method due to its high specificity and potential to be more effective than traditional approaches. The problem of the use of concomitant rehabilitation measures remains in the highlight, as they can help reduce unwanted side effects of the main treatment and improve the overall quality of life of patients. Purpose of the study. To expand the comparative analysis of the quality of life of patients diagnosed with melanoma and receiving immunotherapy, as well as the overall response rate during treatment with the use of accompanying rehabilitation magnetotherapy. Materials and methods. The study included 128 patients diagnosed with melanoma and receiving immunotherapy with pembrolizumab or nivolumab. The patients of the study group (n = 67) underwent a course of immunotherapy and an accompanying course of rehabilitation magnetotherapy. The patients in the control group underwent a course of immunotherapy without accompanying rehabilitation magnetotherapy. Treatment efficacy was assessed according to iRECIST 1.1 criteria. The EORTC QLQ-C30 questionnaire was used to study the quality of life. The degree of adverse events was assessed according to CTCAE 5.0 criteria. Results. The use of accompanying rehabilitation magnetotherapy during the course of immunotherapy led to an improvement in the overall quality of life of patients and a decrease in treatment side effects. Further research in this area is needed in order to determine the potential of magnetotherapy as an additional rehabilitation method.

Lattice distortion induced by rare‐earth ions doping in (Bi0.5Na0.5)TiO3‐based thin films with high piezoelectric properties

AbstractHigh‐performance lead‐free piezoelectric thin films are urgently required for microelectromechanical systems. In this study, thin films based on the 0.8Bi0.5Na0.5TiO3–0.2(Sr0.7Bi0.2□0.1)TiO3 system were prepared on Pt(111)/TiOx/SiO2/Si substrates by a sol–gel method. The large lattice distortions were induced by introducing five rare‐earth ions with different ionic radii (Er/Pr/Sm/Nd/La) to achieve the purpose of regulating the piezoelectric response of the thin films with the maximum inverse piezoelectric coefficient up to 425.9 pm/V. X‐ray diffraction, Raman spectroscopy, Piezoresponse force microscope, and additional testing methods were used to observe the phase composition and microstructure of the thin films to investigate the effect of doping rare‐earth elements with different ionic radii at the A‐site on lattice distortion, and to summarize the transformation law. This study is significant for improving the piezoelectric properties of thin films and has crucial applications in microelectronic sensing.

Investigation of Manufacturability of in-situ crosslinked Polylactic Acid (PLA) and Peroxide composite in additive manufacturing method

Eklemeli imalat, endüstriyel sektörde kullanımı günden güne hızla artan bir üretim teknolojisidir. Eriyik yığma modelleme (FDM) düşük maliyet ve tasarım avantajı ile karmaşık geometrilere sahip ürünlerin üretilmesinde yaygın olarak kullanılan bir eklemeli imalat yöntemidir. Bununla birlikte, FDM ile üretilmiş polimer ürünlerin ara yüzey yapışma mukavemetlerinin düşük olması bu yöntemin zayıf yönünü oluşturmaktadır. Bu çalışmada, FDM teknolojisi ile çalışan 3B yazıcıda polilaktik asit (PLA) filamentinin serilmesi esnasında peroksit takviye edilerek yeni bir kompozit malzeme üretimi gerçekleştirilmiştir. PLA katmanları arasına ince film olarak serilmiş olan peroksit ile polimerin çapraz bağlanmasını sağlayarak katmanlar arasındaki ara yüzey mukavemetinin artırılması amaçlanmıştır. Peroksit ile PLA polimerleri arasında kimyasal bir etkileşim olup olmadığını gözlemlemek için Fourier dönüşümlü kızılötesi spektroskopisi (FTIR) cihazında analizler gerçekleştirilmiştir. Üretilen kompozit örneklerin mekanik özelliklerindeki değişimin gözlemlenebilmesi için çekme dayanım özellikleri araştırılmıştır. Ayrıca, çekme testi sonrasında kompozit numunelerin kopma yüzeyleri taramalı elektron mikroskobu (SEM) ile incelenmiştir. Deneysel sonuçlar, 3B yazıcıda üretilmiş kompozit numunelerde peroksit ile PLA polimerlerinin çapraz bağlanması ile kompozit bir malzemenin üretilebileceğini göstermiştir. Ayrıca çapraz bağlama sayesinde kompozit numunelerin fiberleri arasında ara yüzey mukavemetinin artırıldığı ve buna bağlı olarak mekanik özelliklerinin geliştiği gözlemlenmiştir.

PERAMALAN JUMLAH KEDATANGAN WISATAWAN ASING BANDARA DI BALI DAN BANTEN MENGGUNAKAN METODE HOLT-WINTER ADITIF DAN MULTIPLIKATIF

Tourism is an important sector in the Indonesian economy. One of the benchmarks for the development of the tourism sector is the number of foreign tourist arrivals to Indonesia. Forecasting the number of foreign tourist arrivals is needed so that actors contributing to the tourism sector can optimize their service efforts. It is necessary to forecast the number of foreign tourist arrivals, especially through the arrival gate at I Gusti Ngurah Rai airport (Bali) and Soekarno-Hatta airport (Banten) as one of the main arrival gates most visited by foreign tourists. This study aims to predict the number of foreign tourist arrivals through the airport by comparing the accuracy of the Holt-Winter's additive and multiplicative method. MAPE (Mean Absolute Percentage Error) and the Durbin Watson statistical test are used and to measure the accuracy of the forecast value against the original data. Overall, the MAPE value and Durbin Watson statistical test result indicate that the additive and multiplicative approaches are good enough to be used. However, judging from the smallest MAPE value, Holt-Winter multiplicative is better used in processing data on the number of foreign tourist arrivals at both I Gusti Ngurah Rai and Soekarno-Hatta airports with MAPE values ??of 7.57% and 6.80% respectively.

Frequency domain adaptation of multichannel active road-noise sound control system with virtual sensing

The convergence speed of multichannel adaptive active noise control algorithms can be improved by pre-whitening the reference signals and reducing their cross-correlations. When considering nonstationary processes, like road noise, it proves advantageous to use a short time-based cross-correlation estimation of the reference signal, which can be obtained as part of the bin-normalised frequency domain least-means-squares algorithm. However, the regularisation of such an algorithm is crucial to its success and can further improve the convergence rate. In addition, virtual sensors can be employed by using the additional filter method, which provides targets for the measured error signals to follow, generated from the reference signals. Still, the performance of this virtual sensing is known to be degraded if the properties of the reference signals change, so special consideration should be taken when the reference signals are nonstationary.