bluuebunny/crossref_metadata_2025 huggingface dataset:
Symbol Digit Modalities Test Variant in a Smartphone App for Persons With Multiple Sclerosis: Validation Study
Authors: van Oirschot Pim , Heerings Marco , Wendrich Karine , den Teuling Bram , Martens Marijn B , Jongen Peter J
Published: October 2020

Background

The decline of cognitive processing speed (CPS) is a common dysfunction in persons with multiple sclerosis (MS). The Symbol Digit Modalities Test (SDMT) is widely used to formally quantify CPS. We implemented a variant of the SDMT in MS sherpa, a smartphone app for persons with MS.

Objective

The aim of this study was to investigate the construct validity and test-retest reliability of the MS sherpa smartphone variant of the SDMT (sSDMT).

Methods

We performed a validation study with 25 persons with relapsing-remitting MS and 79 healthy control (HC) subjects. In the HC group, 21 subjects were matched to the persons with MS with regard to age, gender, and education and they followed the same assessment schedule as the persons with MS (the “HC matched” group) and 58 subjects had a less intense assessment schedule to determine reference values (the “HC normative” group). Intraclass correlation coefficients (ICCs) were determined between the paper-and-pencil SDMT and its smartphone variant (sSDMT) on 2 occasions, 4 weeks apart. Other ICCs were determined for test-retest reliability, which were derived from 10 smartphone tests per study participant, with 3 days in between each test. Seven study participants with MS were interviewed regarding their experiences with the sSDMT.

Results

The SDMT scores were on average 12.06% higher than the sSDMT scores, with a standard deviation of 10.68%. An ICC of 0.838 was found for the construct validity of the sSDMT in the combined analysis of persons with MS and HC subjects. Average ICCs for test-retest reliability of the sSDMT for persons with MS, the HC matched group, and the HC normative group were 0.874, 0.857, and 0.867, respectively. The practice effect was significant between the first and the second test of the persons with MS and the HC matched group and trivial for all other test-retests. The interviewed study participants expressed a positive attitude toward the sSDMT, but they also discussed the importance of adapting a smartphone cognition test in accordance with the needs of the individual persons with MS.

Conclusions

The high correlation between sSDMT and the conventional SDMT scores indicates a very good construct validity. Similarly, high correlations underpin a very good test-retest reliability of the sSDMT. We conclude that the sSDMT has the potential to be used as a tool to monitor CPS in persons with MS, both in clinical studies and in clinical practice.
Computing SARS-CoV-2 Infection Risk From Symptoms, Imaging, and Test Data: Diagnostic Model Development (Preprint)
Authors: D'Ambrosia Christopher , Christensen Henrik , Aronoff-Spencer Eliah
Published: October 2020

BACKGROUND

Assigning meaningful probabilities of SARS-CoV-2 infection risk presents a diagnostic challenge across the continuum of care.

OBJECTIVE

The aim of this study was to develop and clinically validate an adaptable, personalized diagnostic model to assist clinicians in ruling in and ruling out COVID-19 in potential patients. We compared the diagnostic performance of probabilistic, graphical, and machine learning models against a previously published benchmark model.

METHODS

We integrated patient symptoms and test data using machine learning and Bayesian inference to quantify individual patient risk of SARS-CoV-2 infection. We trained models with 100,000 simulated patient profiles based on 13 symptoms and estimated local prevalence, imaging, and molecular diagnostic performance from published reports. We tested these models with consecutive patients who presented with a COVID-19–compatible illness at the University of California San Diego Medical Center over the course of 14 days starting in March 2020.

RESULTS

We included 55 consecutive patients with fever (n=43, 78%) or cough (n=42, 77%) presenting for ambulatory (n=11, 20%) or hospital care (n=44, 80%). In total, 51% (n=28) were female and 49% (n=27) were aged <60 years. Common comorbidities included diabetes (n=12, 22%), hypertension (n=15, 27%), cancer (n=9, 16%), and cardiovascular disease (n=7, 13%). Of these, 69% (n=38) were confirmed via reverse transcription-polymerase chain reaction (RT-PCR) to be positive for SARS-CoV-2 infection, and 20% (n=11) had repeated negative nucleic acid testing and an alternate diagnosis. Bayesian inference network, distance metric learning, and ensemble models discriminated between patients with SARS-CoV-2 infection and alternate diagnoses with sensitivities of 81.6%-84.2%, specificities of 58.8%-70.6%, and accuracies of 61.4%-71.8%. After integrating imaging and laboratory test statistics with the predictions of the Bayesian inference network, changes in diagnostic uncertainty at each step in the simulated clinical evaluation process were highly sensitive to location, symptom, and diagnostic test choices.

CONCLUSIONS

Decision support models that incorporate symptoms and available test results can help providers diagnose SARS-CoV-2 infection in real-world settings.
Impact of COVID-19 on Emergency Utilization for Mental Health and Substance Use: A Rapid Review (Preprint)
Authors: Munich Julie , Dennett Elizabeth , Swainson Jennifer , Greenshaw Andrew , Hayward Jake
Published: October 2020

BACKGROUND

A prolonged COVID-19 pandemic has the potential to trigger a global mental health crisis increasing demand for mental health emergency services. We undertook a rapid review of the impact of pandemics and epidemics on emergency department utilization for mental health (MH) and substance use (SU).

OBJECTIVE

To rapidly synthesize available data on emergency department utilization for psychiatric concerns during COVID-19.

METHODS

An information specialist searched Medline, Embase, Psycinfo, CINAHL, and Scopus on June 16, 2020 and updated the search on July 24, 2020. Our search identified 803 abstracts, 7 of which were included in the review. Six articles reported on the COVID-19 pandemic and one on the SARS epidemic.

RESULTS

All studies reported a decrease in overall and MH related ED utilization during the early pandemic/epidemic. Two studies found an increase in SU related visits during the same period. No data were available for mid and late stage pandemics and the definitions for MH and SU related visits were inconsistent across studies.

CONCLUSIONS

Our results suggest that COVID-19 has resulted in an initial decrease in ED visits for MH and an increase in visits for SU. Given the relative paucity of data on the subject and inconsistent analytic methods used in existing studies, there is an urgent need for investigation of pandemic-related changes in ED case-mix to inform system-level change as the pandemic continues.

CLINICALTRIAL

None
Improving Management of Type 2 Diabetes Using Home-Based Telemonitoring: Cohort Study (Preprint)
Authors: Milani Richard , Chava Pavan , Wilt Jonathan , Entwisle Jonathan , Karam Susan , Burton Jeffrey , Blonde Lawrence
Published: October 2020

BACKGROUND

Diabetes is present in 10.5% of the US population and accounts for 14.3% of all office-based physician visits made by adults. Despite this established office-based approach, the disease and its adverse outcomes including glycemic control and clinical events tend to worsen over time. Available home technology now provides accurate, reliable data that can be transmitted directly to the electronic medical record.

OBJECTIVE

This study aims to evaluate the impact of a virtual, home-based diabetes management program on clinical measures of diabetes control compared to usual care.

METHODS

We evaluated glycemic control and other diabetes-related measures after 1 year in 763 patients with type 2 diabetes enrolled into a home-based digital medicine diabetes program and compared them to 794 patients matched for age, sex, race, BMI, hemoglobin A1c (HbA1c), creatinine, estimated glomerular filtration rate, and insulin use in a usual care group after 1 year. Digital medicine patients completed questionnaires online, received medication management and lifestyle recommendations from a clinical pharmacist or advanced practice provider and a health coach, and were asked to submit blood glucose readings using a commercially available Bluetooth-enabled glucose meter that transmitted data directly to the electronic medical record.

RESULTS

After 1 year, usual care patients demonstrated no significant changes in HbA1c (mean 7.3, SE 1.7 to mean 7.3, SE 1.6; P=.41) or changes in the proportion of patients with HbA1c≥9.0 (n=117, 15% to n=113, 14%; P=.51). Digital medicine patients demonstrated improvements in HbA1c (mean 7.3, SE 1.5 to mean 6.9, SE 1.2; P<.001) and significant changes in the proportion of patients with HbA1c≥9.0 (n=107, 14% to n=49, 6%; P<.001), diabetes distress (n=198, 26% to n=122, 16%; P<.001), and hypoglycemic episodes (n=313, 41.1% to n=91, 11.9%; P<.001).

CONCLUSIONS

A digital diabetes program is associated with significant improvement in glycemic control and other diabetes measures. The use of a virtual health intervention using connected devices was widely accepted across a broad range of ethnic diversity, ages, and levels of health literacy.
Heart Rate Variability and Firstbeat Method for Detecting Sleep Stages in Healthy Young Adults: Feasibility Study (Preprint)
Authors: Kuula Liisa , Pesonen Anu-Katriina
Published: October 2020

BACKGROUND

Polysomnography (PSG) is considered the only reliable way to distinguish between different sleep stages. Wearable devices provide objective markers of sleep; however, these devices often rely only on accelerometer data, which do not enable reliable sleep stage detection. The alteration between sleep stages correlates with changes in physiological measures such as heart rate variability (HRV). Utilizing HRV measures may thus increase accuracy in wearable algorithms.

OBJECTIVE

We examined the validity of the Firstbeat sleep analysis method, which is based on HRV and accelerometer measurements. The Firstbeat method was compared against PSG in a sample of healthy adults. Our aim was to evaluate how well Firstbeat distinguishes sleep stages, and which stages are most accurately detected with this method.

METHODS

Twenty healthy adults (mean age 24.5 years, SD 3.5, range 20-37 years; 50% women) wore a Firstbeat Bodyguard 2 measurement device and a Geneactiv actigraph, along with taking ambulatory SomnoMedics PSG measurements for two consecutive nights, resulting in 40 nights of sleep comparisons. We compared the measures of sleep onset, wake, combined stage 1 and stage 2 (light sleep), stage 3 (slow wave sleep), and rapid eye movement (REM) sleep between Firstbeat and PSG. We calculated the sensitivity, specificity, and accuracy from the 30-second epoch-by-epoch data.

RESULTS

In detecting wake, Firstbeat yielded good specificity (0.77), and excellent sensitivity (0.95) and accuracy (0.93) against PSG. Light sleep was detected with 0.69 specificity, 0.67 sensitivity, and 0.69 accuracy. Slow wave sleep was detected with 0.91 specificity, 0.72 sensitivity, and 0.87 accuracy. REM sleep was detected with 0.92 specificity, 0.60 sensitivity, and 0.84 accuracy. There were two measures that differed significantly between Firstbeat and PSG: Firstbeat underestimated REM sleep (mean 18 minutes, P=.03) and overestimated wake time (mean 14 minutes, P<.001).

CONCLUSIONS

This study supports utilizing HRV alongside an accelerometer as a means for distinguishing sleep from wake and for identifying sleep stages. The Firstbeat method was able to detect light sleep and slow wave sleep with no statistically significant difference to PSG. Firstbeat underestimated REM sleep and overestimated wake time. This study suggests that Firstbeat is a feasible method with sufficient validity to measure nocturnal sleep stage variation.
Using a Personal Health Library–Enabled mHealth Recommender System for Self-Management of Diabetes Among Underserved Populations: Use Case for Knowledge Graphs and Linked Data (Preprint)
Authors: Ammar Nariman , Bailey James E , Davis Robert L , Shaban-Nejad Arash
Published: October 2020

BACKGROUND

Traditionally, digital health data management has been based on electronic health record (EHR) systems and has been handled primarily by centralized health providers. New mechanisms are needed to give patients more control over their digital health data. Personal health libraries (PHLs) provide a single point of secure access to patients' digital health data and enable the integration of knowledge stored in their digital health profiles with other sources of global knowledge. PHLs can help empower caregivers and health care providers to make informed decisions about patients’ health by understanding medical events in the context of their lives.

OBJECTIVE

This paper reports the implementation of a mobile health digital intervention that incorporates both digital health data stored in patients’ PHLs and other sources of contextual knowledge to deliver tailored recommendations for improving self-care behaviors in diabetic adults.

METHODS

We conducted a thematic assessment of patient functional and nonfunctional requirements that are missing from current EHRs based on evidence from the literature. We used the results to identify the technologies needed to address those requirements. We describe the technological infrastructures used to construct, manage, and integrate the types of knowledge stored in the PHL. We leverage the Social Linked Data (Solid) platform to design a fully decentralized and privacy-aware platform that supports interoperability and care integration. We provided an initial prototype design of a PHL and drafted a use case scenario that involves four actors to demonstrate how the proposed prototype can be used to address user requirements, including the construction and management of the PHL and its utilization for developing a mobile app that queries the knowledge stored and integrated into the PHL in a private and fully decentralized manner to provide better recommendations.

RESULTS

To showcase the main features of the mobile health app and the PHL, we mapped those features onto a framework comprising the user requirements identified in a use case scenario that features a preventive intervention from the diabetes self-management domain. Ongoing development of the app requires a formative evaluation study and a clinical trial to assess the impact of the digital intervention on patient-users. We provide synopses of both study protocols.

CONCLUSIONS

The proposed PHL helps patients and their caregivers take a central role in making decisions regarding their health and equips their health care providers with informatics tools that support the collection and interpretation of the collected knowledge. By exposing the PHL functionality as an open service, we foster the development of third-party applications or services and provide motivational technological support in several projects crossing different domains of interest.
The Influence of CEO Hubris on Firm Performance in Indonesia: The Moderating Effects of CEO Power and Board Vigilance
Authors: Rizka Noni Ayu , Handoko T. Hani
Published: October 2020

Past studies on CEO hubris has found that board vigilance is effective in managing the negative outcome of hubris. Some studies found CEO non-duality and independent director representation are effective in decreasing the damage of hubris. However, these studies have only explored the causal relationship of hubris and firm performance in the one-tier corporate governance setting. This study analyzed the influence of CEO hubris on firm performance in Indonesia by taking into account the CEO-board power dynamics. Indonesia adopts the two-tier corporate system where the board is divided into the board of directors and commissioners. Through 99 public listed companies, this study found that hubris in Indonesian CEOs contributes well to firm performance. Moreover, a bigger commissioner board is effective in strengthening the positive influence of hubris on firm performance in Indonesia. Furthermore, this study hints that two-tier corporate governance is more efficient in controlling hubris than the one-tier system.
PHOTOCATALYTIC DEGRADATION OF METHYLENE BLUE USING IRON OXIDE NANOPARTICLES SYNTHESIZED USING ANNONA MURICATA LEAF EXTRACT
Authors: JOSE BEENA , THOMAS FEMY
Published: October 2020

Objective: The objective of the present study is the synthesis of iron oxide nanoparticles using Annona muricata aqueous leaf extract, characterization of the synthesized nanoparticles and evaluation of the antibacterial, photocatalytic activity and cytotoxicity.

Methods: The iron oxide nanoparticle was synthesized using Annona muricata aqueous leaf extract and the crystal structure of the iron oxide nanoparticle was determined by UV-Visible spectroscopy, Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). The in vitro cytotoxicity of iron oxide nanoparticles was evaluated using Dalton’s lymphoma ascites cells and the antibacterial assay was conducted using agar well diffusion method.

Results: The UV-Visible spectrum of iron oxide nanoparticle showed a maximum absorption peak at 265 nm. This is the XRD pattern of iron oxide nanoparticles exhibited a distinct peak at 26.029 (2θ), accounting for crystal plane (211). SEM images revealed that the synthesized iron oxide nanoparticles were aggregated as irregular sphere shapes with rough surfaces. TEM image reveals the size of the synthesized iron oxide nanoparticles are spherical in shape with an average size of 20 nm. Green synthesized iron oxide nanoparticles using Annona muricata leaf extract effectively degraded methylene blue dye.

Conclusion: This study showed that the synthesized iron oxide nanoparticles using Annona muricata aqueous leaf extract exhibited pronounced antibacterial, anticancer and photocatatytic activity and can be used in the textile industry for the purification of water contaminated with carcinogenic textile dyes. It can also be used as an external antiseptic in the prevention and treatment of bacterial infections.
HYPOGLYCEMIC AND HYPOLIPIDEMIC EFFECTS OF OLDENLANDIA CORYMBOSA AGAINST ALLOXAN INDUCED DIABETES MELLITUS IN RATS
Authors: ELWON CAYSANDRA AUDREY MICHELLE , SHAH MUHAMMAD DAWOOD , IQBAL MOHAMMAD
Published: October 2020

Objective: The present study was designed to demonstrate the antioxidant, hypolipidemic and hypoglycaemic potentials of aqueous extract of O. corymbosa against alloxan-induced diabetes in rats.

Methods: O. corymbosa extract was tested for phytochemical screening, total phenolic, flavonoids content and DPPH free radical scavenging activity. Diabetes was induced in Sprague Dawley rats by administration of alloxan monohydrate (65 mg/kg b. w i. v). The aqueous extract of O. corymbosa at a dose of 100 mg/kg and 200 mg/kg were administered through gavage feeding daily to diabetic induced rats for 14 d. The effect of aqueous extract of O. corymbosa was assessed on blood glucose, body weight, lipid peroxidation, catalase activity, glutathione and lipid profile. Pancreatic tissues were also examined by haematoxylin and eosin staining methods.

Results: Phytochemical screening shows the presence of tannins, saponins, phlobatannins and flavonoids. Total phenolic content was found to be 22.85±0.21 mg/g, IC50 is 450±1.39 µg/ml and total flavonoids content was found to be 4.25±0.09 mg/g of extract. The results of the present study showed that O. corymbosa can lower blood glucose and lipid parameters except for HDL. The levels of antioxidant enzymes CAT and GSH were increased along with the decreased in LPO level by the pre-treatment of animals with O. corymbosa. Microscopic examination of pancreatic sections revealed that diabetic rats treated with O. corymbosa extracts at either dose have normal architecture structure of islets.

Conclusion: These results indicate that O. corymbosa may be effective as a hypoglycaemic and antihyperlipidemic agent.
ПОТЕНЦИАЛ ТОЛСТОПЛЕНОЧНОЙ ТЕХНОЛОГИИ
Authors: Васютин М.С. , Островский Д.П. , Адарчин С.А. , Гурин В.М.
Published: October 2020

В работе описаны современные возможности электронных компонентов, получаемых по толстопленочной технологии, показаны преимущества использования такой технологии.
БЛОК ТЕНЗОРНЫХ ВЫЧИСЛЕНИЙ ДЛЯ УСКОРЕНИЯ РАСЧЕТА ИСКУССТВЕННЫХ НЕЙРОННЫХ СЕТЕЙ
Authors: Осипенко П.Н. , Увкин И.В.
Published: October 2020

Разработан конфигурируемый СФ-блок тензорных вычислений для ускорения расчета искусственных нейронных сетей (IVA_TPU), предназначенный для встраивания в СнК. Приведены характеристики СФ-блока и параметры разрабатываемых микросхем на его основе. Дается описания маршрута программирования СФ-блока IVA_TPU.
ОСОБЕННОСТИ РЕАЛИЗАЦИИ ИЗМЕРИТЕЛЬНОЙ СХЕМЫ КОНТРОЛЛЕРОВ ПРОЕКЦИОННОЕМКОСТНЫХ СЕНСОРНЫХ ПАНЕЛЕЙ ДЛЯ СЛОЖНОЙ ПОМЕХОВОЙ ОБСТАНОВКИ
Authors: Тикменов В.Н. , Скляров С.Н. , Автушенко И.В. , Воронов А.С.
Published: October 2020

Рассмотрены вопросы проектирования измерительной схемы сенсорной панели. Проанализированы подходы к повышению стойкости к внешним помехам. Приведены результаты моделирования работы различных вариантов измерительных схем, определены их преимущества и недостатки, предложен алгоритм повышения устойчивости работы сенсора.
СХЕМА НОРМАЛИЗАЦИИ КАНАЛА СБОРА ДАННЫХ НА ОСНОВЕ УСИЛИТЕЛЯ С ПРОГРАММИРУЕМЫМ КОЭФФИЦИЕНТОМ УСИЛЕНИЯ
Authors: Рогаткин Ю.Б.
Published: October 2020

Представлен программируемый усилитель для использования вместе с аналого-цифровым преобразователем средней точности и быстродействия в микроконтроллерах устройств промышленного Интернета вещей.
МЕТОДЫ МОДЕЛИРОВАНИЯ РАДИАЦИОННО-ИНДУЦИРОВАННЫХ СЛУЧАЙНЫХ СБОЕВ В КОМБИНАЦИОННЫХ СХЕМАХ НА СХЕМОТЕХНИЧЕСКОМ И ЛОГИЧЕСКОМ УРОВНЕ
Authors: Тельпухов Д.В. , Надоленко В.В. , Деменева А.И. , Жукова Т.Д.
Published: October 2020

Разработаны автоматизированные методы моделирования случайных сбоев переключения на логическом и схемотехническом уровне. Проведено исследование методов на наборе схем LGSynth’89.
La adaptación y las instituciones de educación superior: conceptos y desafíos
Authors: Roncancio-Roncancio Patricia
Published: October 2020

Este trabajo busca delimitar el concepto de adaptación para configurar un escenario que permita comprender las interacciones entre el concepto y las prácticas administrativas en las instituciones de educación superior (IES) privadas. Con frecuencia se asigna a la administración la tarea de lograr la adaptación de la organización. Sin embargo, no se encuentran trabajos que indiquen cómo el adoptar una noción de la adaptación puede impactar la toma de decisiones y la construcción de indicadores de gestión de las IES. La revisión sistemática de literatura evidencia que los fenómenos adaptativos y administrativos suelen abordarse de manera independiente, por lo que el estado de la teoría en este campo es insuficiente. La ruta metodológica responde a las características de una heurística que posibilite la construcción de un campo de problemas para la investigación y la comprensión de la adaptación de las universidades latinoamericanas, desde su administración. La discusión permite delinear escenarios para la investigación y señala desafíos a nivel de la elaboración de políticas públicas y de la administración de las IES.
Reseña del libro de Eduardo Míguez, Crítica (y reivindicación) de la universidad
Authors: Aragón-Falomir Jaime-Arturo
Published: October 2020

El sugestivo título muestra que la crítica tendrá un lugar central que marca el agudo pulso de la obra y que, si bien la “reivindicación” está presente, estará acotada. El texto se convierte en un documento esencial para entender las aristas problematizadas que podemos encontrar en su análisis del caso argentino, igualmente reflejadas en sistemas educativos latinoamericanosiento”
PdFeCo Supported on N-rGO as a Bifunctional Catalyst for Methanol Oxidation and High Stability Oxygen Reduction Reaction
Authors: Vietanti Frizka , Wang Chen-Hao
Published: October 2020

In this study, we have synthesized nitrogen doped reduced graphene oxide (N-rGO) supported ternary PdFeCo nanoparticle by three methods. A hydrothermal method to synthesize N-rGO, an emulsion method to synthesize PdFeCo nanoparticle, and a rota-evaporation to synthesize PdFeCo/N-rGO composite. A bifunctional PdFeCo/N-rGO exhibited excellent electrocatalytic activity towards both methanol oxidation and stability in oxygen reduction reaction (ORR). During methanol oxidation reaction, PdFeCo/N-rGO exhibited stronger methanol tolerance than Pt/C. In stability ORR, PdFeCo/N-rGO exhibited 2.85 times greater than Pt/C  in ORR stability. The high performance of PdFeCo/N-rGO was attributed by strong bonding of structure. A strong bonding of transition metals in Pd based catalyst can servemethanol tolerance and stability during ORR activity.
Fractional Recrystallization Behavior of Impurity-Doped Commercially Pure Aluminum
Authors: Kaiser Mohammad Salim
Published: October 2020

This manuscript reports the effects of trace impurities on the fractional recrystallization behavior of commercially pure aluminum. To allow the recrystallization cold rolled by 75% alloy samples are annealed isothermally at 700ºK for different time up to 60 minutes. Recrystallization kinetics is evaluated from the micro hardness variation of the different annealed samples. The JMAK type analysis is also used to study the recrystallization behavior as well as to observe the correlation with the experimental results. The behavior of the fraction recrystallization between two methods the trace impurities added alloys is evidence for the higher variation as to form GP zones and metastable phases during annealing. Higher addition shows the more variation as the formation of higher fraction phases. The microstructural study reveals that annealing at 700ºK for 30 minutes the alloys attain almost fully re-crystallized state.
Aluminum Combustion under Different Condition: A Review
Authors: Nurdiansyah Haidzar , A M. Miftahul , Ridha Fabrobi
Published: October 2020

This paper reviews the collection of literature on aluminum combustion, with an emphasis on various parameters used. These parameters which affect combustion of aluminum are particles size and oxygen content. Aluminum is a material that is often used in combustion processes due to its effortless reactive material and explosive. A large amount of research has been published about combustion in aluminum materials where aluminum can be used as a way to increase propulsion in combustion. The purpose of this paper is to review some aspects that affect combustion in aluminum. It goes on to discuss the particles size differences and the different oxygen content mixture with gas in used. The results of various existing studies show that there is a difference in ignition temperature and burning time effect in aluminum combustion due to the size and oxygen content. Where, decreasing particles size can decrease ignition temperature and burning time. The review paper is intended to outline a parameter range for aluminum combustion.
Design of a High Sea Wave Sensor System in Puger Beach
Authors: Fibriani Ike , Irawan Januar Fery , Satriya Alfredo Bayu , Utomo Satrio Budi , Hadi Widyono , Widjonarko Widjonarko , Khoiril Khoiril
Published: October 2020

Indonesia is an archipelagic country that has a very wide sea area. Thus, Indonesian sea has a huge potential of natural resources that can be utilized to grow the nation's economy. There are many occupations and efforts that can be done to increase the income from the sea and also to conserve it. Fishery is one of the most effective way to gain the sea resources; however, fishery is limited by the weather condition on the sea. This is also a problem that happened in Puger Beach. Puger Beach is located in the south Jember and it faces the Hindia Ocean, which means the weather condition is more dangerous for fishermen than other part of coastal. To ensure the safety of the fishermen, the weather condition on the sea must be evaluated and predicted before the fishery. This study designed a system to provide fishermen in Puger Beach an information about sea and beach weather condition which consist of wave height prediction, wind speed, temperature, humidity and weather prediction. The wind speed is obtained from self-designed anemometer system, the temperature is measured using LM35 sensor, and the humidity is assessed using DHT22. The wave height in the sea was predicted by calculating the wind speed value and effective average fetch value using neural network algorithm. The weather on the sea and on the beach were predicted by rain and light sensor. This weather prediction would be classified into three different results, namely raining, cloudy and bright. After some experiments, the result showed that the device can provide the information needed for fishermen and it has a high sensing accuracy. The humidity measurement had an average error of 1.1%, the temperature measurement had 1.42% average error, and 2.37% for the wind speed measurement. The wave height measurement system worked out and found the average wave height in Puger Beach 0.37 meters.
Kinetics Study of Acid Catalyzed Degradation of Glucose in High-Temperature Liquid Water
Authors: Rahmawati Atiqa , Saputri Aulia Iin , Gunardi Ignatius
Published: October 2020

Glucose is the most abundant monosaccharide in nature, glucose obtained from cellulose and starch, it is many used to degradation process, and for the production of several organic compounds, one of the degradation products of glucose is an HMF (5-hydroxymethylfurfural). HMF is a platform chemical, which can be converted into several chemical and liquid fuels through hydrogenation, oxidation, and esterification. The objective of this researches has studied the kinetics of glucose degradation using acid-catalyzed (H2SO4) in high-temperature liquid water and observe the effect of acid concentration and temperature on degradation of glucose to HMF. In this research was used reactor with pressure 10 atm, with variation time of reaction, sulfuric acid concentration, and temperature of the reaction. From this research found kinetics of glucose degradation was followed by the first-order reaction in each variable. Activation Energy (Ea) values were 7306,593 J/mol; 6341,59 J/mol; 3988,14 J/mol and 3988,14 J/mol on the concentration sulfuric acid 0,05M; 0,1 M; 0,05M, from that result indicated that reaction rate was increase when activation energy was decrease this was related to Arrhenius equation. The effect of acid concentration on degradation glucose was the higher acid concentration used, the more glucose was degraded, and more HMF was formed. Meanwhile, the effect of temperature of reaction on degradation glucose was the higher temperature of the reaction, more glucose was degraded, and more HMF was formed. The highest value of HMF was in operation condition of concentration H2SO4 0,5 M at 175°C, with a time of reaction 120 minutes. However, the reduction rate of glucose was not equal to the rate of formation of HMF (5-hydroxymethylfurfural), it can be indicated that HMF (5-hydroxymethylfurfural) was not the only product of degradation of glucose, but the others product might be formed from this operating condition. The other product that might be formed was humin and levulinic acid.
The Effect of Agitation Parameter on Hardness and Thickness of Decorative Nickel-Chrome Coating on A36 Steel using Electroplating Process
Authors: Harsito Akmal Hanif Khairullah , Aisyah Iis Siti , Daryono Daryono , Saifullah Ali , Hendaryati Heni , Sudarman Sudarman
Published: October 2020

Electroplating is a process of settling substances (metal ions) on the electrodes (cathodes) using electrolysis. The occurrence of a precipitate in this process is due to the presence of electrically charged ions moving from an electrode through the electrolyte, the result of the electrolyte will seal on another electrode (cathode). During the process of deposition/deposit takes place a chemical reaction occurs at the electrode and electrolyte both reduction in a certain direction permanently, therefore it requires direct current and a constant voltage. Metal coatings commonly used are copper, nickel, chromium, and others. Electroplating is basically to coat the metal to make it look more attractive and protected from corrosion, and can increase the product's resistance to friction. The purpose of this study was to determine the effect of stirrer rpm variations on the thickness and thickness of the A36 steel layer in the decorative nickel-chrome electroplating process. 4 specimens in this study were 30x30x2 (mm). Nickel and chromium coatings have variations in the speed of 72, 102, 132, and 162 (rpm) with a time immersion of 22 minutes and with a temperature of 55-60 ° C. The results of this electroplating process were tested by Vickers's hardness test and observation of microstructure results. The results showed that the faster the rpm, the more hardness was obtained which increased and the thickness of the layer increased. The highest hardness and thickness values are found at a rotational speed of 132 rpm. With a hardness value of 77.5 VHN and a thickness value of 4.55 µm (Nickel) and 13.76 µm (Chrome).
Exit only: harms from silencing employee voice
Authors: Adkins Karen
Published: October 2020

The nationwide shortage of PPE for health care workers has been well documented. Reporting on this issue has been complicated by hospitals' imposition of gag orders on physicians and health care workers. There are harms that result from imposing these gag orders that go beyond the obvious harms to public and employee health and safety. Using Hirschman's ‘Exit, Voice, and Loyalty’ (1970) as a framework demonstrates that these orders represent a dangerous concentration of power in employer hands — health care workers are reduced to functionaries. Hirschman's argument, in part, is that organisations should seek to balance the availability of exit, voice, and loyalty for employees. Restricting employee options in morally untenable situations to exit only leads to direct and indirect harms. These gag orders are a pernicious practice, and bring with them long-term negative implications for employee morale, employee effectiveness, and public service.
Science communication for the Deaf in the pandemic period: absences and pursuit of information
Authors: G. Silva Alexandre , Batista Tiago , Giraud Felipe , Giraud Andrea , Pinto-Silva Flavio Eduardo , Barral Julia , Nascimento Guimarães Juan , rumjanek Vívian
Published: October 2020

COVID-19 pandemic hit Brazil in February 2020. Controversial information, minimization of the problem, and difficulties resulting from extreme social inequality, led to the intensification of the disease and number of deaths. During this period, the government failed to provide information to the Deaf minority that uses Brazilian Sign Language to communicate. This study analyzes information provided by a TV with accessibility, as well as a Facebook page created by Deaf and hearing interpreters, and videos posted on Instagram and YouTube for that community. The novelty of the subject required linguistic efforts so that information could be coherent in sign language.
COVID-19 infections on international celebrities: self presentation and tweeting down pandemic awareness
Authors: Mututwa Wishes , Matsilele Trust
Published: October 2020

The novel coronavirus (COVID-19) which was first reported in China's Wuhan province in December 2019 became a global pandemic within a few months. The exponential rise in COVID-19 cases globally was accompanied by a spike in misinformation about the pandemic, particularly on social media. Employing Social Network Theory as a lens, this qualitative study explores how selected international celebrities appropriated their Twitter micro-blogging pages to announce their COVID-19 infection to the world. The study finds that these celebrities can take advantage of their huge social media following to counter disinfodemic and promote awareness about health pandemics.
Aportes al estudio paleodietario mediante el análisis de isótopos estables de δ13C y δ15N en restos óseos humanos de la región centro-oriental del Cauca medio
Authors: Osorio Ramírez Katherine Andrea
Published: October 2020

La dieta, considerada como hábito alimenticio, es un componente biocultural fundamental en todas las sociedades, en particular en las precolombinas. Se reconstruye mediante la combinación de indicadores arqueológicos y bioarqueológicos que hacen posible identificar el uso y consumo de diferentes tipos de alimentos y su relación con otras variables culturales (p. e., la jerarquía) y demográficas (p. e., el sexo y la edad). El objetivo del presente estudio es reconstruir la dieta de ocho individuos prehispánicos de yacimientos arqueológicos del centro-oriente del Cauca medio, entre los siglos IX y XIV d. C., mediante razones de isótopos estables de C y N ( δ13C y δ15N). Los resultados evidencian la importancia de los recursos alimenticios disponibles en la región, así como diferencias y similitudes en el uso y consumo de alimentos entre los sitios investigados.
Schiff bases of 1,5-diarylpent-4-ene-1,3-diones and their metal complexes: Synthesis, characterization and fluorescent studies
Authors: Ummathur Muhammed , Pallikkavil Radhika , Krishnankutty Krishnannair
Published: October 2020

Four Schiff bases (H2L1 to H2L4) were synthesized by the condensation of o-aminophenol and unsaturated diketones (1,5-diarylpent-4-ene-1,3- -diones). Analytical, IR, 1H-NMR and mass spectral data revealed their existence in the imine?enamine form. Dibasic tetradentate coordination of the Schiff bases in their ML complexes (M = Cu(II), Ni(II), Co(II), Zn(II), Cd(II), and Hg(II)) was established based on physical, analytical and spectral data. The fluorescent studies of H2L4 showed that the fluorescence emission maxima shifted with increasing polarity and hydrogen bonding ability of the solvent. Paramagnetic Cu(II), Ni(II) and Co(II) ions decrease the fluorescence intensity with increasing concentration of the metal ion while diamagnetic Zn(II), Cd(II) and Hg(II) ions have very little influence on the fluorescence intensity of the Schiff base H2L4.
Probabilistic design strategy for improved Austin-Moore stem used in artificial cementless hip prosthesis considering material property uncertainty
Authors: Kharmanda G. , Antypas I. R.
Published: October 2020

Introduction. The use of probabilistic analysis is important when the input data are random, that leads to stochastic results. This paper describes the integration of a probabilistic design strategy of the solid and hollow stems implanted in a proximal femur in order to compare their advantages. The used hollow stem is called “Improved Austin-Moore” (IAM) model.

Materials and Methods. Probabilistic methods allow variations in factors which control the biomechanical effects of the implanted femur to be taken into account while determining its performance. Different material properties were generated randomly using Monte Carlo simulation (MCS). Monte Carlo sampling techniques were applied, and different von Mises stresses of the layers (bone and metal) were chosen as a performance indicator.

Results. A simple 2D implant-bone study of solid and IAM stem design was carried out with a high level of confidence, 99.87%, which corresponds to a target reliability index with regard to statistical uncertainties. The probabilistic design results show that the input and output parameters for the IAM stem are highly correlated relative to those for the solid stem.

Discussion and Conclusions. The sensitivity analysis shows that the input parameters for the IAM stem play a much larger part in the output parameters relative to the solid stem. The IAM stem is much more advantageous than the solid stem which causes an increase in the performance of the hip prosthesis.
Bucket working bodies with conveyor bottom: systematics and design features
Authors: Lyashenko Yu. M. , Revyakina E. A. , Lyashenko A. Yu.
Published: October 2020

Introduction. The creation of new types of bucket working bodies of excavators through synthesizing technical solutions to improve the transporting functions of the bottom is considered. These solutions are based on reducing the resistance and energy consumption under digging-in and scooping due to the transition from sliding friction to rolling friction during the movement of the rock mass along the bottom of the bucket.

Materials and Methods. Analysis of the bulk materials handling processes using existing loading appliances identified design flaws that affect the efficiency of their operation. Advanced design diagrams of loading bodies were searched on the basis of the accumulated experience and the study of the morphological features of the existing equipment. Combinatorial analysis of possible combinations of elements with their various qualitative compositions, mutual arrangement, imposed links, and synthesis of new technical solutions for loading and transportation modules are carried out.

Results. The results of the morphological synthesis implementation were the systematization and development of designs of bucket working bodies with a bottom in the form of a roller surface and a closed belt, as well as with a conveyor-type drive mechanism. The application of rollers as a supporting surface of a loaded rock mass causes a decrease in friction forces and in the power capacity of the work process. In addition, rotating rollers provide uniform abrasion of the working surface, which increases significantly the time to the equipment breakdown and increases the process efficiency. Working bodies with a drive mechanism make it possible to activate the interaction of the conveyor bottom in the form of a closed belt with the rock mass and, as a result, to accelerate the process of filling the bucket container.

Discussion and Conclusions. The bucket working bodies described in the paper compare favorably with existing analogues in that they provide a reduction in the time to digging-in, scooping and unloading, a decrease in specific energy consumption, an increase in bucket filling, which ultimately contributes to an increase in productivity. A slight increase in the structural complexity and cost of the working body causes additional capital costs, which are paid back within two to four months.
Overview of fuzzy vehicle routing problems
Authors: Chernyshev Yu. O. , Kubil V. N. , Trebukhin A. V.
Published: October 2020

Introduction. Various algorithms for solving fuzzy vehicle routing problems are considered. The work objective was to study modern methods for the optimal solution to fuzzy, random and rough vehicle routing problems.

Materials and Methods. The paper reviews fuzzy vehicle routing problems, existing methods and approaches to their solution. The most effective features of some approaches to solving fuzzy vehicle routing problems considering their specificity, are highlighted.

Results. The Fuzzy Vehicle Routing Problem (FVRP) occurs whenever the routing data is vague, unclear, or ambiguous. In many cases, these fuzzy elements can better reflect reality. However, it is very difficult to use Vehicle Routing Problem (VRP) solving algorithms to solve FVRP since several fundamental properties of deterministic problems are no longer fulfilled in FVRP. Therefore, it is required to introduce new models and algorithms of fuzzy programming to solve such problems. Thus, the use of methods of the theory of fuzzy sets will provide successful simulation of the problems containing elements of uncertainty and subjectivity.

Discussion and conclusions. As a result of reviewing various methods and approaches to solving vehicle routing problems, it is concluded that the development and study of new solutions come into sharp focus of researchers nowadays, but the degree of elaboration of various options varies. Methods for the optimal solution of FVRP are limited, in general, to some single fuzzy variable. There is a very limited number of papers that consider a large number of fuzzy variables.
Revisiting computer modeling
Authors: Yadrovskaya M. V.
Published: October 2020

Introduction. Modeling serves as a methodological basis for modern science and a tool for cognitive activity. It can be considered as a thinking activity mediated and optimized through information models. In this case, logical operations of cognition and simulation techniques are applied to the information.

Materials and Methods. The scientific research results on how knowledge is formed, stored and processed in a person's memory, how they interact with information representations are studied and summarized. Information models used in various subject domains are analyzed. The provisions on rational ways of presenting information under modeling are formulated, and computer tools for constructing such representations are indicated.

Results. Methods and techniques for visualizing information on the object under study are specified. Software tools and services providing visualizations and research modeling procedures are given.

Discussion and Conclusions. The results obtained can be used to optimize modeling procedures. Images, structures, relationships and connections of the object under study are visualized in special programs with the help of the described methods and techniques. They, in turn, mediate the process of mental modeling and broaden the basis for its implementation.
ANALISIS MODEL MENTAL SISWA MENGGUNAKAN TES DIAGNOSTIK MODEL MENTAL TWO-TIER (TDM-TWO-TIER) PADA MATERI LAJU REAKSI
Authors: Armawita Armawita , Okmarisa Heppy
Published: October 2020

AbstractThis research was instigated by student mental model that was not intact on Reaction Rate lesson.  It aimed at analyzing and knowing student mental model through Two-Tier (TDM-Two-Tier) Mental Model Diagnostics Test instrument (TDM-Two-Tier) on Reaction Rate lesson at State Senir High School 2 Pekanbaru.  This research was conducted at the first semester in the Academic Year of 2019/2020.  It was Descriptive quantitative research.  The data in this research were collected by Two-Tier (TDM-Two-Tier) Mental Model Diagnostics Test instrument, interview, and documentation.  The collected data were analyzed by using Descriptive analysis.  Purposive Sampling technique was used in this research.  The samples of this research were 36 students at the eleventh grade of MIPA 2 of State Senior High School 2 Pekanbaru.  The research findings showed that student mental model was not intact.  It could be seen from the mean score of student mental model that was obtained from TDM-Two-Tier Diagnostics Test, Scientifically Correct (SC) of intact mental model or Scientifics was 47%, Partially Correct (PC) or partial mental model or alternative was 48%, students were able to understand the macroscopic level was 12%, symbolic level was 17% and submicroscopic level was 19% and Specific Misconception (SM) or misconception was 5%.  Keywords: Mental Model, TDM-Two-Tier, Reaction Rate
PENGEMBANGAN LKPD BERBASIS OSBORN PADA POKOK BAHASAN LAJU REAKSI UNTUK KELAS XI SMA/MA SEDERAJAT
Authors: Ari Angga Yogi , Wati Susila , Wetti Rasmi
Published: October 2020

This study aims to develop Student Worksheets Based on Osborn on the subject of valid reaction rates based on aspects of content suitability, Osborn characteristics, language, presentation, and graphics. This type of research is research and development (R and D) with reference to the Plomp development process. The subject of this study was a student worksheet based on Osborn. Data collection instrument is a validation given to three validators, and from the data analysis, the validity of the content aspect, Osborn characteristic aspects, language aspects, presentation aspects, and graphic aspects are 95.8%, 100%, 88.28%, 88.86% and 91.62% with a valid category. The student worksheet validated by the validator was tested on 30 students and got a response result with a percentage of 89.35% with very good criteria, and from two teachers got a response result with a percentage of 93.75% with very good criteria. Based on the results of data analysis, it can be concluded that the student worksheet based on OSBORN produced is valid and can be used for the subject of the reaction rate.