bluuebunny/crossref_metadata_2025 huggingface dataset:
Geoarqueologia de Julio Cezar Rubin de Rubin e Rosiclér Theodoro da Silva (Editores)
Authors: Villagran Ximena S.
Published: June 2023

O livro “Geoarqueologia”, organizado pelos Profs. Julio Cezar Rubin de Rubin e Rosiclér Theodoro da Silva, publicado pela editora da PUC de Goiás em 2013, representa um avanço no desenvolvimento da geoarqueologia na América do Sul por três motivos: dá continuidade à primeira obra publicada pelos mesmos organizadores em 2008; reúne tanto trabalhos de pesquisadores já reconhecidos na área, assim como trabalhos realizados por pesquisadores jovens; contém uma diversidade de temas, cronologias e áreas de estudo que servem como panorama do atual campo de ação da disciplina no nosso continente.
Construindo um trabalho sobre musealização da arqueologia
Authors: Toledo Grasiela Tebaldi
Published: June 2023

A construção de uma pesquisa sobre Musealização da Arqueologia envolve diferentes questões e enfoques, não sendo possível consolidar um modelo único de trabalho nesse campo. A Musealização da Arqueologia mostra-se cada vez mais plural, pois os trabalhos, mesmo sendo particularmente diferentes, norteiam-se por premissas comuns, que garantem uma linha de pensamento e atuação que envolve a salvaguarda e a comunicação dos acervos e sítios arqueológicos. Nesse artigo será apresentado como uma pesquisa nessa área foi construída, contribuindo para a ampliação das discussões acerca da preservação e divulgação de uma memória local/regional, através da pesquisa arqueológica desenvolvida na Estância Velha do Jarau, Quaraí/RS e a investigação museológica realizada nos museus da Fronteira Oeste do Rio Grande do Sul.
Applications and design peculiarities of modern controllable-pitch propellers
Authors:   Krylov State Research Centre, St. Petersburg, Russia, Pustoshny A.V. , Borusevich V.O. ,   Krylov State Research Centre, St. Petersburg, Russia, Bushuev A.V. ,   NPO Vint, JSC Ship Repair Centre Zvezdochka, Moscow, Russia, Gaberzettel F.I. ,   Krylov State Research Centre, St. Petersburg, Russia
Published: June 2023

Object and purpose of research. This paper discusses controllable-pitch propellers (CPPs) of various designs. The purpose of this study was to summarize the findings of CPP studies in Russia and abroad, as well as to identify current challenges in Russian CPP design and manufacturing. Materials and methods. This paper relies on the test data obtained at Deepwater Tank and cavitation tunnels of Krylov State Research Centre. It analyses the results of computational studies for CPP hydrodynamics and strength obtained as per the latest techniques of CFD and FE analysis. Main results. The history of CPP design and manufacturing in Russia clearly shows that our country has considerable expertise in design of controllable-pitch propellers that can operate in the harshest conditions. Analysis of global shipbuilding experience has shown that CPPs not only ensure optimal operational conditions for “engine-propeller” system in the conditions of variable hydrodynamic load on the propeller, but also feature better cavitation and vibroacoustic performance because the skew of CPP blades can be moderate and high: actually, it can be significantly higher than for fixed-pitch propellers (FPPs) because FPP blades in reversal conditions do not have to operate their trailing edges forward, which reduces the risk of high stresses and damage of skewed blades in crash-stop scenarios. Analysis of CPP test results obtained at Krylov State Research Centre hydrodynamic and cavitation laboratories, as well as the findings of foreign computational studies enabled justified assessment of CPP advantages. It also highlighted the challenges that require dedicated studies and special consideration in design of skewed CPPs, so as to improve their performance in partialcavitation and cavitation-inception conditions. Conclusion. Currently, Russia has all the pre-requisites for increased production and wide application of modern CPPs. Controllable blades with moderate and high skew have a certain potential in terms of improving their vibroacoustic performance as compared to FPPs. However, to design these blades correctly, with consideration of their possible operational risks, it is necessary to use state-of-the art computational and experimental methods, as well as to rely on the experience of full-scale trials.
One-step Spray coating CsPbBr3 film for planar photodetector applications
Authors: Thanh Bui Xuan , Phuong Nam Tran , Hoan Tran Quoc , Tuan Pham Van , Thanh Tung Duong
Published: June 2023

Metal halide perovskite, a promising semiconductor material, is suitable for new generation optoelectronic application. In comparison to organic -inorganic hybrid perovskites (OIHP), all inorganic CsPbX3 (X = Cl, Br and I) show superior thermal and chemical stability. Although there are many kinds of coating procedures for producing perovskite QDs peorovskite film, most studies of CsPbX3 perovskite thin film fabrication focus on solution processing techniques such as spin coating. Unfortunately, the CsPbBr3 precusor dissolubility is very low compared to OIHP, resulting in a low materials utilization and poor uniformity for the large-scale area. In this work, we report a facile spray coating method to produce CsPbBr3 film on pre-patterned Pt electrode for photodetector (PD) application. The spray-coated perovskite was demonstrated suitable for photodiode application with numbers figure of merit such as: A high responsivity of 60 A/W, high detectivity of 6× 10-13 Jones, the response time (rising and fall time) below 17 ms were obtained at 1 V under 405 nm illumination. From this study, we belive that the spray deposition technique will benefit for futher thin film-based perovskite optoelectronic devices.
Use of Recurrence Plots to Find Mutations in Deoxyribonucleic Acid Sequences
Authors:   Universidad Autónoma de Nuevo León, Pedro de Alba S/N, Niños Héroes, Ciudad Universitaria, San Nicolás de los Garza, N. L, México, Rivas-Cisneros D. E.
Published: June 2023

This paper examines the use of recurrence plots to find changes in the deoxyribonucleic acid (DNA) sequence. The DNA sequence is entered into the recurrence plot algorithm in codons and not consecutively, in order to make it easier to find the nucleotide change. The results show that the codon arrangement makes it easy to identify two types of mutations, insertion and deletion, by means of the recurrence plot. It is also shown that the recurrence plot of a short codon sequence has a homogeneous structure. Similarly, a comparison is made with the digital signal processing methodology. Some limitations are the number of codons that can be entered into the algorithm because computationally it becomes very slow and matrix issues, which are mentioned in the discussion section.
IMPLEMENTATION OF PSC COST RECOVERY AND PSC GROSS SPLIT CONTRACTS IN THE IYP FIELD
Authors: Irvan Yulian Pratama  , Bayu Satiyawira  , Prayang Sunny Yulia
Published: June 2023

In producing oil and gas, Indonesia has two valid contract schemes, namely PSC Cost Recovery and PSC Gross Split. The IYP field is a field that has great potential in producing petroleum, with 25 workover and 2 infill wells. The scheme released to compare with the PSC Cost Recovery scheme is the Gross Split PSC scheme. The previous scheme was considered to be ineffective and still detrimental to the government. So the government issued Ministerial Regulation No. 52 of 2017 which is the result of a revision of Permen no. 8 of 2017. Gross Split PSC Scheme, the contractor bears all operational costs for the development of oil and gas fields. The economic research on the IYP field aims to compare the Cost Recovery PSC scheme with the Gross Split PSC.
ANALISIS DENSITAS LUMPUR STARCH DAN DRISPAC TERHADAP PROSES PENGANGKATAN CUTTING DENGAN MENGGUNAKAN METODE CUTTING TRANSPORT RATIO
Authors: Rangga Wastu Apriandi Rizkina , Husla Ridha , Yasmaniar Ghanima , Yulia Prayang Sunny , Dio Mario Valentino , Subardja Tedy
Published: June 2023

The use of the right drilling mud in a drilling well has a good ability to clean the hole so that the process of removing the cutting to the surface can run optimally.. Aim: In this research, we will analyze the physical properties of density mud using starch and Drispac mud samples which are natural. The two mud samples are used to find out whether the two mud samples can carry cuttings optimally. Cutting Transport Ratio is one of the cutting removal methods used in the cutting lifting process using the average speed and slip speed of the mud. The cutting removal process can be said to be successful if it has a percentage of > 50%. Methodology and Results: The starch and Drispac sludge samples will be tested using several temperatures, namely 150°F, 200°F and 250°F. Both samples will be tested for their physical properties, namely the density value. The selected density value is one of the parameters needed in the slip speed calculation process in the cutting lifting process. The density value obtained in the starch mud sample was 8.7-9.1 ppg while in the Drispac sample it was 8.65 - 9 ppg. These results are the initial results obtained, but because the results on the 200°F and 250°F samples are not in accordance with the specifications, an additional barite is needed for each of these samples. Both starch and drispac sludge added 60 grams of barite at a sample temperature of 200°F and 120 grams at a sample temperature of 250°F. The results of the density values ​​obtained when barite was added were 10-10.7 ppg for starch mud samples and 9.9-10.65 ppg for Drispac mud samples. The results of the density test will be carried out by testing the removal of cuttings using the Cutting Transport Ratio. The results obtained for the two samples, for starch sludge, obtained a value of 98.31-99.19% while for drispac mud 98.61-99.18%.m. Conclusions: The increase in temperature causes the value of the filtration loss to decrease because the water content in the filtrate also evaporates, causing the filtration loss to decrease. The mudcake value in this experiment was also influenced by the results of the filtration loss value. The higher the filtration loss value, the thicker the value of the mudcake is due to the large number of precipitated particles.
Probability of Trajectory Deviation of Unmanned Aerial Vehicle in Presence of Wind
Authors: Banerjee Portia , Corbetta Matteo , Jarvis Katelyn , Smalling Kyle , Turner Andrew
Published: June 2023

Incorporating unmanned aerial vehicles (UAVs) into the United States National Airspace System would demand enhanced airspace safety technologies for the safety of the UAVs, people, and property on the ground. One of the safety-critical factors to consider is the risk of a UAV deviating from its planned trajectory, which may result in loss of separation between other vehicles or obstacles or may cause early depletion of battery power. In this paper, we studied the effect of wind on UAV trajectory deviation by incorporating wind velocity as a drag component in a six-degrees-of-freedom trajectory simulation comprising a rotorcraft lumped-mass model. Both steady-state wind and wind turbulence effects were investigated. We validated our approach using real flight data from UAV experiments conducted at NASA Langley Research Center. The proposed approach would enable risk-informed decision making by timely mitigation of current and future collision events in an uncertain and dynamic environment.
The analysis of the effect of cutting mode and coolant on formation of burrs when drilling aluminum alloy
Authors:   Omsk State Technical University, Kisel A. G. , Makashin D. S. ,   Omsk State Technical University, Belan D. Yu. ,   Omsk State Transport University, Averkov K. V. ,   Omsk State Transport University
Published: June 2023

Drilling is an extremely important process widely used in the manufacture of fuel control equipment. The sustainable drilling process of aluminum alloy is promising for today's industry, which reduces energy and coolant consumption without compromising the quality of workmanship. This article examines the effect of feed and spindle speed on maximum power input, the height of the burrs generated during drilling, and the resulting deviation in the diameter of the drilled hole.
The analysis of power curves of wind power plants
Authors:   Saint Petersburg Mining University, Belsky A. A. , Zamyatin A. I. ,   Saint Petersburg Mining University
Published: June 2023

The use of wind power plants is growing rapidly, despite the continued growth in the extraction of traditional fossil resources. In this paper, the analysis of the power curves of real wind turbine models and the polynomials common among the scientific community describing the dependence of the wind turbine output power on wind is carried out. The article discusses 82 models of wind power plants with a horizontal axis of rotation, rated power up to 100 kW and with a method of limiting the speed of rotation in the operating mode pitch control. The calculation of the potential generation of each wind turbine at an oil and gas field for a period of twenty years with an interval of one hour is carried out, the Installed Capacity Utilization Factor is calculated, after which the values are compared with the results of calculations based on polynomials of other authors. The results obtained can be widely applied in modeling the operating modes of wind power plants and will improve the accuracy of feasibility studies for the implementation of autonomous power supply systems.
THE LONG-TERM DYNAMICS OF ZOOBENTHOS COMMUNITIES IN THE LAKE UNDER CONDITIONS OF WASTEWATER POLLUTION FROM APATITE- NEPHELINE PRODUCTION
Authors:   Institute of North Industrial Ecology Problems, Russian Academy of Sciences, Kola SC, 14a Fersman st., Apatity, 184 209, Russia, Valkova S.A.
Published: June 2023

The changes in the composition and structure of zoobenthos of Bolshoi Vudyavr Lake were analyzed in the long-term dynamics. Benthic fauna is characterized by low taxonomic diversity. Zoocenosis consists of eurybiont species of oligochaetes (Tubifi cinae), chironomids (Chironiminae, Tanypodinae), and mollusks (Pisidiidae) in the deep-water zone. Chironomids Orthocladiina dominated in the littoral zone. Communities are complemented by bivalves, oligochaetes and invertebrates typical for the littoral zone of the lakes (gastropods, caddisfl y, beetles, mayfl ies, stonefl ies). In the structure of deep-water biocenoses there is a tendency of increasing of mollusks Pisidiidae. Their share in the total number of invertebrates increased from 30 % in 2001 to 66 % in 2022. Zoobenthos are characterized by relatively high values of abundance number and biomass. The average level of biomass of zoobenthos in the lake varies from “moderate” (5,0–10,0 g/m2) to “elevated” class (10–20 g/m2).
ASSESSMENT OF THE STATE OF WATER, BOTTOM SEDIMENTS AND SOILS OF THE BEZYMYANNY STREAM FLOOD PLAIN (VLADIVOSTOK)
Authors:   Federal Scientific Center of the East Asia Terrestrial Biodiversity, Far East Branch of the Russian Academy of Sciences, Vladivostok, 690022, Russia, Zharikova E.A. , Popova A.D. ,   Federal Scientific Center of the East Asia Terrestrial Biodiversity, Far Eastern Branch of the Russian Academy of Sciences, Vladivostok 690022, Russia, Klyshevskaya S.V. ,   Federal Scientific Center of the East Asia Terrestrial Biodiversity, Far East Branch of the Russian Academy of Sciences, Vladivostok, 690022, Russia
Published: June 2023

The main parameters of the chemical composition of water, bottom sediments and soils ii monitoring sites have been laid from the headwaters to the mouth of the Bezymyanny stream were determined. The characterization of sanitary and microbiological properties of river water is carried out. An increase in the content of macroelements and heavy metals in bottom sediments and soils. The level of pollution was determined using various geoecological indicators. The consequence of the infl uence of the solid waste landfi ll and the highway is an extremely high level of environmental risk on the Glass Beach.
NEW DATA ON THE COMPOSITION OF CYANOBACTERIA AND ALGAE OF SOME WATERCOURSES OF THE KAMCHATKA PENINSULA
Authors:   Federal Scientific Center of the East Asia Terrestrial Biodiversity, Far East Branch of the Russian Academy of Sciences, Vladivostok, 690022, Russia, Medvedeva L.A. , Nikulina T.V. ,   Federal Scientific Center of the East Asia Terrestrial Biodiversity, Far Eastern Branch of the Russian Academy of Sciences, Vladivostok 690022, Russia, Semenchenko A.A. ,   Federal Scientific Center of the East Asia Terrestrial Biodiversity, Far East Branch of the Russian Academy of Sciences, Vladivostok, 690022, Russia,   Institute of the World Ocean, Far Eastern Federal University, Russky Island, 10 Ajax Bay, Vladivostok, 690922, Russia, Seliverstov N.A. ,   Institute of the World Ocean, Far Eastern Federal University, Russky Island, 10 Ajax Bay, Vladivostok, 690922, Russia
Published: June 2023

The results of studying the biological diversity of the fl ora of freshwater algae in some streams of the Kamchatka Peninsula are presented, the structure of algal periphyton communities is revealed and the ecological characteristics of the studied algofl ora are given. The following rivers were surveyed: Kamchatka, Andrianovka, Plotnikova, Avacha, Paratunka, Gavanka, Kirpichnaya, Karymshina, Mutnushka and the Perviy stream. As a result of sample processing, 193 species, varieties and forms of cyanobacteria and algae from fi ve divisions were found: Cyanobacteria – 5 species, Bacillariophyta – 167 taxa (taking into account varieties and forms – 177), Ochrophyta – 2, Charophyta – 4, Chlorophyta – 5. In the algae communities of the surveyed water bodies, both in terms of abundance in fouling and species diversity, diatoms prevailed. The most common species, often growing on stones and dominating in fouling, were Encyonema minutum, E. silesiacum, Hannaea arcus, Gomphonema ventricosum, Ulnaria inaequalis, Cocconeis placentula, Fragilaria capucina, Nitzschia palea. Melosira varians, Meridion circulare, Planothidium lanceolatum, Gomphonella olivacea, species of the genera Staurosira, Diatoma, Cymbella, Fragilaria and some others were most often present as subdominants. In some cases, Rhoicosphenia abbreviata, Didymosphenia geminata, and Tabularia fasciculata took the fi rst places in terms of abundance. Of the Chlorophyta Ulothrix zonata and Cladophora glomerata were found. In a number of streams Hydrurus foetidus was encountered in mass. The division of Charophyta is represented by fi laments of Spirogyra and single specimens of the genera Closterium and Cosmarium. Cyanobacteria practically did not form mass fouling, except for the Tapinothrix genus. For each surveyed area, the species composition of algae was determined and complexes of dominant species were characterized. Giving a general ecological characteristic of the studied algofl ora, it should be noted that benthic and planktonic- benthic organisms predominate in periphyton communities, which are indiff erent to water salinity and prefer a slightly alkaline habitat.
FIRST INFORMATION ON THE STONEFLY FAUNA (INSECTA, PLECOPTERA) OF THE BOTCHINSKY AND THE TUMNINSKY NATURE RESERVES (KHABAROVSK TERRITORY)
Authors:   Federal Scientific Center of the East Asia Terrestrial Biodiversity, Far East Branch of the Russian Academy of Sciences, Vladivostok, 690022, Russia, Teslenko V.A.
Published: June 2023

For the fi rst time, the results of long-term studies of the fauna of amphibiotic insects of stonefl ies inhabiting the watercourses of the Botchinsky and the Tumninsky Nature Reserves are presented. The common annotated list includes 41 species from 24 genera and 8 families, 24 species were revealed in the stonefl y fauna of the Botchi River basin and 35 species in the Tumnin River basin. The plecopterofauna is close to the Lower Amur River fauna and is represented mainly by widespread Eastern Palaearctic species.
NEW DATA ON MOLLUSCAN FAUNA OF THE UBSUNUR HOLLOW RESERVE (THE REPUBLIC OF TYVA, RUSSIA)
Authors:   Federal Scientific Center of the East Asia Terrestrial Biodiversity, Far East Branch of the Russian Academy of Sciences, Vladivostok, 690022, Russia, Sharyi-ool M.О.
Published: June 2023

New data on a molluscan fauna of the «Ubsunur Hollow» UNESCO Reserve are presented. Species Odhneripisidium stewarti (Preston, 1909) (Bivalvia: Sphaeriidae) is recorded for Russia and Mongolia for the fi rst time.
HYDROCHEMISTRY OF THE ZEYA RESERVOIR IN HIGH-WATER YEARS
Authors:   Institute of Water and Ecological Problems FEB RAS, 56 Dikopoltsev St., Khabarovsk 680000, Russia, Shesterkin V.P. , Terskiy P.N. ,   State Oceanographic Institute named after N.N. Zubov, Moscow,   A.M. Obukhov Institute of Atmospheric Physics Russian Academy of Sciences, 3, Pyzhyovskiy pereulok, Moscow, 119017, Russia, Gorin S.L. ,   Russian Federal Research Institute Of Fisheries and Oceanography (VNIRO), 19 Okruzhnoy proezd, Moscow, 105187, Russia,   A.M. Obukhov Institute of Atmospheric Physics Russian Academy of Sciences, 3, Pyzhyovskiy pereulok, Moscow, 119017, Russia
Published: June 2023

The results of studying the chemical composition of the waters of the Zeya reservoir in high-water years (2013, 2021) are presented. It is shown that a signifi cant infl ow of water into the reservoir during these years caused in its waters a uniform distribution of concentrations of dissolved substances in the water area and depth in the summer- autumn period and extremely uneven in winter. The maximum values of mineralization, concentrations of calcium, magnesium, bicarbonate and sulfate ions, ammonium nitrogen, organic substances and dissolved iron were established in winter in the estuarine areas of the Argi and Zey regions as a result of the infl uence of cryogenic processes and fl ooding of the marshes of the Upper Zey plain. In the dam and canyon parts of the reservoir in winter, there were no large diff erences in mineralization values (28,4–41,9 mg/dm3), low content of ammonium nitrogen (< 0,03 mg N/dm3), increased values of water color (62–87°), concentrations of dissolved iron (0,35–0,74 mg/dm3) and organic matter (10,0–13,3 mg O/dm3). An assumption is made about the receipt of large amounts of dissolved substances in the Amur River in winter due to increased water consumption of the Zeyskaya HPP
LONG-TERM DYNAMICS OF PERIPHYTON ALGAE PIGMENT CHARACTERISTICS OF THE AMURSKAYA CHANNEL OF THE AMUR RIVER (KHABAROVSK TERRITORY)
Authors:   Institute of Water and Ecological Problems FEB RAS, 56 Dikopoltsev St., Khabarovsk, 680000, Russia, Yavorskaya N.M. , ,   Federal State Budgetary Institution «Zapovednoe Priamurye», 60 Seryshev St., Khabarovsk 680038, Russia, Klimin M.A. ,   Institute of Water and Ecological Problems FEB RAS, 56 Dikopoltsev St., Khabarovsk, 680000, Russia
Published: June 2023

As a result of long-term studies of the content of photosynthetic pigments in periphyton algae in the Amurskaya channel of the Amur River during a period of high water level, it was found that chlorophylls predominate in the pigment fund, its basis is chlorophyll a (68 %). The interannual and seasonal dynamics of photosynthetic pigments has a cyclical nature, in which an increase in their content is observed in spring and autumn, after the passage of fl oods and the establishment of low water, and a decrease occurs in summer during fl oods. The trophic status of the channel according to the weighted average values of chlorophyll a concentration over the growing seasons is estimated as mesotrophic (second quality class, clean waters). The Amurskaya channel, previously classifi ed as a hypereutrophic watercourse, changed its status to eutrophic.
O papel da vigilância epidemiológica no controle de surtos de doenças infecciosas no SUS
Authors: Silveira Rodrigo Euripedes da , Silva Francisco Ronner Andrade da , Santos Marcos Antônio Lima dos , Salgado Paula Regina Rodrigues , Guedes Erik Vinicius Barros , Padilha Kethelin Cristina Carvalho , Fachini Mérlim , Fernandes Jefferson Douglas Lima , Rocha Rachel Leal Marcelino da , Souza Luiz Claudio Oliveira Alves de
Published: June 2023

Objetivo: Analisar qual o papel da vigilância epidemiológica no controle de surtos de doenças infecciosas no SUS. Métodos: Trata-se de uma revisão integrativa, os artigos foram pesquisados entre janeiro e março de 2023, nas bases de dados SCIELO, BVS e Acervo+ Index Base, além de utilizar o mecanismo de busca do Google Acadêmico. Os Descritores em Ciências da Saúde (DeCS) foram: vigilância epidemiológica, sistema único de saúde, doenças contagiosas e saúde pública. Os critérios de inclusão foram: estudos gratuitos, em português e publicados entre os anos de 2018 e 2023. Os critérios de exclusão foram estudos duplicado, fora do tema proposto, incompletos, teses e projetos de conclusão de curso. Foram selecionados vários artigos no processo de triagem, porém apenas oito estudos foram escolhidos para fazer parte da amostra final. Resultados: O papel da vigilância epidemiológica, além da coleta de dados, é adotar medidas preventivas e de controle, como a vacinação, a distribuição de medicamentos e a implementação de medidas de higiene e segurança. Considerações finais: Conclui-se que, a vigilância epidemiológica permite a identificação rápida e eficaz de casos e surtos de doenças, além de monitorar a evolução das doenças e avaliar a efetividade das medidas adotadas.
Mapping the Genesis of the Abraham Accords Elite Preferences, Rising Nationalism, and the Quest for Political Stability
Authors: Çınkara Gökhan , Coşkun Batu
Published: June 2023

The Abraham Accords have presented themselves as one of the most significant geopolitical developments in the Middle East in this decade. They represent a trend in which increasingly, Arab states are seeking their own geopolitical arrangements with the State of Israel. This commentary considers the Abraham Accords from the lenses of elite preferences and nationalism –arguing that the recent politicization of the Gulf-Arab elite constitutes the nexus of the Abraham Accords. We argue that the Abraham Accords were born from a desire of bolstering regime security, regional security and extend local transformations to the international domain. Our analysis opens the literature to a wider discussion on the political capital of Gulf elites, and how increasingly their decisions impact wider Middle Eastern geopolitics.
Prevalence of hepatitis B virus infection among antenatal attendees in a university teaching hospital in Southern Nigeria
Authors: Ukpe Michael Thompson , Abasiattai Aniekan Monday , Utuk Ntiense Macaulay , Umoh Augustine Vincent , Ibanga Godwin Jim
Published: June 2023

Objectives:

The aim of the study was to determine the prevalence of HBV infection among pregnant women receiving antenatal care at the University of Uyo Teaching Hospital, Nigeria.

Material and Methods:

This was a cross-sectional study of 291 antenatal attendees over a period of 3 months. Blood samples from all consenting pregnant women were tested for hepatitis B surface antigen (HBsAg) and antibody, hepatitis B envelop antigen and antibody, and hepatitis C antibody serum markers for HBV infection. A structured questionnaire was used to obtain sociodemographic data and the presence of risk factors. Data obtained were analyzed using SPSS, version 17.0.

Results:

Twenty-three women (7.9%) tested positive for Hepatitis B core antibody, while 6 (2.1%) tested positive for HBsAg. None tested positive for Hepatitis B envelop antigen. Forty-one (14.1%) women showed evidence of post vaccination immunity while 8 (2.8%) had evidence of post-infection immunity. Two hundred and twenty-seven (78.0%) women were susceptible to HBV infection. Higher educational attainment correlated significantly with less risk of acquiring HBV infection (P = 0.003).

Conclusion:

Our study revealed an intermediate prevalence and low infectivity of HBV infection among our pregnant women. Government and non-governmental organizations should intensify efforts to create awareness about the disease through public enlightenment campaigns, as well as recall systems through systems of mobile communication.
A study on needs to design English teaching materials at vocational school
Authors: Abidah Lailatul , Askangela Mifta Libby , Berlianty Declarieta , Herliana Noor Aina , Qomariah Nunuk Nur , Teladan Ryan Permadi , Sabilah Fardini
Published: June 2023

English for Specific Purpose (ESP) instruction in vocational schools necessitates the use of English materials that are tailored to the students' particular requirements. However, the English materials currently available for vocational institutions lack an adequate needs analysis. In order to address this issue, the purpose of this study is to determine the requirements of students in the computer and network engineering department for procedure text teaching materials. Eleventh-grade students majoring in computer and network engineering were selected by simple random sampling and surveyed for the study. The results indicated that the primary objective of the students' explanation-based learning process was to enhance their speaking skills. In addition, instructors favoured interactive, engaging, and simple-to-understand multimedia learning to teach English. This research can be used as a guide for designing English language instructional materials that meet the requirements of vocational students, especially those majoring in computer and network engineering.
Teachers’ challenges and strategies in using digital media in teaching English
Authors: Salam Urai , Wahdini Wahdini , Surmiyati Surmiyati , Rezeki Yanti Sri , Riyanti Dwi , Suthathothon Payupol
Published: June 2023

This study aimed to identify the challenges faced by teachers in integrating digital media in EFL classrooms and explore their innovative solutions to overcome them. Data were derived from interviews with teachers who attempted to incorporate digital media in a variety of situations. Official documents, including local and national government regulations, school websites, school YouTube channels, and lesson plans supplemented the interview data. The results revealed that teachers faced challenges such as lack of competence, deficient teaching materials, and inadequate digital teaching skills when attempting to integrate technology into their classroom. Limitations of infrastructures, such as low internet bandwidth and a scarcity of devices available in their schools were also reported as additional contributing challenges. Despite the difficult circumstances, evident in the study were teachers’ willingness and efforts to make use of a diverse array of technology devices and applications in their classrooms. These included projectors, laptops, smartphones, audio speakers, as well as software such as word processors, PowerPoint, Google Classroom, Hot Potatoes, search engines, WhatsApp, Zoom, Google Meet, online dictionaries, YouTube, and video editors. This study sheds light on the resilience and resourcefulness of EFL teachers in adapting to digital media and offers insights into ways to support and enhance their efforts.
JENIS BIAYA DAN PENDAPATAN PETERNAK LEBAH MADU KELULUT DI DUSUN KAYU ARA DESA KAYU ARA KECAMATAN MANDOR KABUPATEN LANDAK
Authors: Ansyah Heri , Hardiansyah Gusti , Mariani Yeni
Published: June 2023

Kelulut honey cultivation business is a potential business. This study aims to determine the types of costs, income, and profits as well as the feasibility of kelulut honey cultivation as well as the obstacles faced by kelulut honey entrepreneurs.The research method is carried out by surveying with census data collection techniques. Collecting data using primary data and secondary data with data collection techniques, namely observation and interview techniques. Data analysis using descriptive analysisthe business processes of the kelulut honeyare nest preparation, box nest making, colonybreakdown, feed preparation, harvesting and making cultivation racks. From the 20 respondents of bee honey entrepreneurs, the results of the study showed a fixed cost of Rp. 12.405.070/month and variable costs Rp. 218,000/month. The total cost of business is Rp. 12.623.070/month. The honey income earned by the kelulut honey business is Rp. 13,500,000/month.The profit earned is Rp. 876.930/month, and business feasibility obtained a > 1 = 1.07.Keywords: Cost of farming, Income, Feasibility, Kelulut honeyAbstrakUsaha budidaya kelulut adalah usaha yang berpotensial. Penelitian ini bertujuan untuk mengetahui jenis biaya, pendapatan dan keuntungan serta kelayakan dalam usaha budidaya kelulut serta kendala-kendala yang dihadapi pengusaha kelulut. Metode penelitian dilakukan dengan survei dengan teknik pengambilan data secara sensus. Pengumpulan data menggunakan data primer dan data sekunder dengan teknik pengambilan data yaitu teknik observasi dan wawancara. Analisis data menggunakan analisis deskriptif. Proses usaha kelulut yaitu penyiapan sarang, pembuatan sarang kotak, pemecahan koloni, penyiapan pakan, pemanenan dan pembutan rak budidaya. Dari 20 responden pengusaha kelulut menunjukan bahwa biaya tetap sebesar Rp. 12.405.070/bulan dan biaya tidak tetap Rp. 218.000/bulan. Total biaya usaha sebesar Rp. 12.623.070/bulan. Pendapatan madu yang di peroleh oleh  usaha lebah madu kelulut yaitu Rp. 13.500.000/bulan. Keuntungan yang diperoleh sebesar Rp. 876.930, dan kelayakan usaha yang di dapatkan a >1 = 1,07.Kata kunci: Biaya usaha, Pendapatan, Kelayakan, Madu Kelulut
Utilization of Luminescent Carbon Nanodots from Soybean Husk Wastes for Fingerprint Identification using Tracker Software Spectrum Analysis
Authors: Dwandaru Wipsar Sunu Brams , Hidayatullah Abdul Rosyid , Listari Eka Sentia Ayu , SL Deby Grace
Published: June 2023

Visible fingerprints (FPs) play a crucial role in forensic identification, and luminescent carbon nanodots (C-Dots) have shown promise in enhancing their visibility. However, the optimal concentration of C-Dots for effective coating remains largely unexplored. This research aimed to determine the ideal C-Dots concentration for FPs identification. The fingerprint (FP) patterns of two subjects, L and P, were analyzed, revealing intensity peaks in 200 mm - 250 mm and 100 mm - 150 mm, respectively. The FP patterns were observed using a light microscope and Tracker software spectral analysis. The C-Dots samples were produced with variation in concentrations of (%W/V) 40%, 43.4%, and 47.6%. The spectrophotometer ultraviolet-visible (UV-Vis) test of the C-Dots showed absorption peaks at 270 nm and 330 nm wavelengths. The photoluminescence test indicated that the C-Dots have cyan luminescence. The X-ray diffraction (XRD) test showed that the C-Dots were amorphous. The spectrometer Fourier transform infrared (FTIR) test showed the presence of C = C functional groups. The scanning electron microscope (SEM) images with 5000x magnification showed the surface morphology of the C-Dots mimicking crumpled papers. Using Tracker software, FPs were successfully differentiated, with the clearest visual FPs observed when using a C-Dots concentration of 43.4%. Thus, the optimal concentration of C-Dots for FP identification was 43.4%.
Beneath the Surface: Identifying Subsurface Caves in "Gua Pandan" Using Integrated Electrical Profiling Method
Authors: Antosia Risky Martin , Akbar Hendra Hidayat , Santoso Nono Agus , Putri Intan Andriani , Farishi Bilal Al , Natalia Happy Christin
Published: June 2023

One of the geopark tourism areas in East Lampung Regency, "Gua Pandan," has run into rock subsidence on the surface. As part of the subsidence prevention, indirect electrical methods between resistivity and chargeability profiling were applied to identify the presence of a subsurface cave in the study area. Two measurement lines were carried out with Wenner Alpha and Wenner Schlumberger arrays. Because the depth target is shallow (approximately 10 m) and to obtain a better resolution, each line has a stretch length of 70 m and 2 m electrode spacing. A line was measured over a known underground cave to produce a desired outcome, and the other was in an area with no cavities. Based on the results from each profile of resistivity and chargeability, an air-filled target has a value of over 5,000  and under 6 ms, respectively. Then, integrated processing of both methods generated a metal factor (MF) profile to view the presence and estimated shape of the cave/ cavities. The result represents that an MF value under 1.5 ms/Ωm is a cavity, and solid rock is over 1.5 ms/Ωm. Also, the MF level from both configurations delineates a similar section. However, a modest difference occurs in estimating the cavity shape geometry,  for Wenner Apha and  for Wenner Schlumberger. Furthermore, this study can be an initial step in safety assessment in the area.
Identifying Pore Type of Lagoon and Barrier Carbonate to Model Shear Wave Velocity in Salawati Basin by Differential Kuster-ToksÖz
Authors: Wulandari Yulia Putri , Rosid Mohammad Syamsu
Published: June 2023

The shape of pores in sedimentary rocks is dependent on the geometric structure of the rock matrix grains. Carbonate rocks have more complex pore types compared to clastic due to the effects of diagenesis and the depositional environment. The study analyzed the deposition of Kais carbonate in barrier and lagoon environments. It categorized the pores into inter-particle, moldic/vuggy, and micro-cracks. The type of pore in a rock is directly related to its stiffness and shear resistance, which influences its shear wave velocity (Vs). Thus, a higher shear modulus leads to a higher Vs value. Reservoir characterization heavily relies on the Vs data. However, this data is limited to the observed area. Therefore, Vs modeling is a more effective and efficient approach. The modeling will conduct thoroughly with the identification of the pore type. The rocks moduli are calculated by the pore inclusion method using the differential Kuster-Toksöz (DKT) equation and defining the aspect ratio, reflecting the pore type. The YP-1 well has barrier carbonate, while YP-2 and YP-3 have lagoon carbonate with inter-particle as the primary pore type. Micro-cracks on top of Kais are present. YP-4 and YP-5 have similar proportions of micro-cracks and inter-particle as dominant pore types. The predicted Vs and measured logs strongly correlate with an R2 value above 0.8. The Vs value range for micro-cracks is 2,300 ft/s to 6,000 ft/s, and for inter-particle, it is 6,000 ft/s to 8,500 ft/s. Pore types above 8,500 ft/s are very stiff (moldic pore type).
Intrinsic Bond Strength Index as a halogen bond interaction energy predictor
Authors: Šivickytė Ona , Costa Paulo J.
Published: June 2023

Halogen bonds (XBs) have become increasingly popular over the past few years with numerous applications in catalysis, material design, anion recognition, and medicinal chemistry. To avoid a \textit{post factum} rationalization of XB trends, descriptors can be tentatively employed to predict the interaction energy of potential halogen bonds. These typically comprise the electrostatic potential maximum at the tip of the halogen, ${V_{S, max}}$, or properties based on the topological analysis of the electronic density. However, such descriptors either can only be used with confidence for specific families of halogen bonds or require intense computations and, therefore, are not particularly attractive for large datasets with diverse compounds or biochemical systems. Therefore, the development of a simple, widely applicable, and computationally cheap descriptor remains a challenge as it would facilitate the discovery of new XB applications while also improving the existing ones. Recently, the Intrinsic Bond Strength Index (IBSI) has been proposed as a new tool to evaluate any bond strength, however, it has not been extensively explored in the context of halogen bonding. In this work, we show that IBSI values linearly correlate with the interaction energy of diverse sets of closed-shell halogen-bonded in the ground state, and therefore, can be used to quantitatively predict this property. Although the linear fit models that use quantum-mechanics-based electron density provided MAEs typically below 1~kcal~mol$^{-1}$, this type of calculation might still be computationally heavy in large sets or systems. Therefore, we also explored the exciting possibility to use a promolecular density approach (\pro{}), which only requires the geometry of the complex as an input, being computationally cheap. Surprisingly, the performance was comparable to the QM-based methods, thus opening the door for the usage of \pro{} as a fast, yet accurate, XB energy descriptor in large datasets but also in biomolecular systems such as protein--ligand complexes. We also show that $\delta g^{pair}$ descriptor emerging from the Independent Gradient Model that leads to IBSI can be seen as a term proportional to the overlapping van der Waals volume of the atoms at a given interaction distance. Overall ISBI can be thought of as a complementary descriptor to ${V_{S, max}}$ for situations when the geometry of the complex is available and QM calculations are not feasible whereas the latter still remains a hallmark of XB descriptors
Pseudo-equilibrium equations for calcium phosphate precipitation with multi-unit particles
Authors: ZHANG Tian-Lan
Published: June 2023

In the reaction of calcium phosphate precipitation from a near-neutral solution, an amorphous phase and hydroxyapatite nanoparticles appear successively, and the reaction system containing either of the two kinds of precipitates is in a non-equilibrium state. Here, we report an extension of our previous study on the relationship between a precipitate and the corresponding ion product in pseudo-equilibrium states. We adopted two reaction series, collected samples at various stages, and analyzed the solution chemistry data on the basis of a simplified reaction model. We derived two types of pseudo-equilibrium equations from the two series, respectively. These equations reveal the presence of multiple structural units in a precipitate particle and correlate the ion product with the average value of the surface proportion per structural unit (m). The m value decreased as the number of structural units in a particle (u) increased. Besides, we determined the free energy differences (ΔG) from the pseudo-equilibrium constants (Kd), which explains the observations in the crystal ripening process well. Notably, the two types of pseudo-equilibrium equations take the common form of “Kd = ion product” if u→∞. Overall, our findings provide new insights into the study of precipitation reactions. The relationship between the ion product and the structural unit of a precipitate particle is not only fundamental in chemistry, but may also be applicable to certain natural or biological systems at non-equilibrium, such as marine sedimentation and human vascular calcification.
Exploring the Role of Solvent Polarity in Mechanochemical Knoevenagel Condensation: In-situ Tracking and Isolation of Reaction Intermediates
Authors: Scheurell Kerstin , Martins Ines , Murray Claire , Emmerling Franziska
Published: June 2023

Mechanochemistry has proven to be a highly effective method for the synthesis of organic compounds. We studied the kinetics of the catalyst-free Knoevenagel reaction between 4-nitrobenzaldehyde and malononitrile, activated and driven by ball milling. The reaction was investigated in the absence of solvents (neat grinding) and in the presence of solvents with different polarities (liquid-assisted grinding). The reaction was monitored using time-resolved in-situ Raman spectroscopy and powder X-ray diffraction (PXRD). Our results indicate a direct relationship between solvent polarity and reaction kinetics, with higher solvent polarity leading to faster product (2-(4-nitrobenzylidone)malononitrile) formation. For the first time, we were able to isolate and determine the structure of an intermediate 2-(hydroxy(4-nitrophenyl)methyl)malononitrile based on PXRD data
Spectral tuning and excitation-energy transfer by unique carotenoids in diatom light-harvesting antenna
Authors: Fujimoto Kazuhiro J. , Seki Takuya , Minoda Takumi , Yanai Takeshi
Published: June 2023

The light-harvesting antennae of diatoms and spinach are composed of similar chromophores; however, they exhibit different absorption wavelengths. Recent advances in cryoelectron microscopy have revealed that the diatom light-harvesting antenna fucoxanthin chlorophyll a/c-binding protein (FCPII) forms a tetramer and differs from the spinach antenna in terms of the number of protomers; however, the detailed molecular mechanism remains elusive. Herein, we report the physicochemical factors contributing to the difference in light absorption between the light-harvesting antennae of diatoms and spinach based on spectral calculations using an exciton model. Spectral analysis reveals the significant contribution of unique fucoxanthins (fucoxanthin-S) in FCPII to the diatom-specific spectrum, and further analysis determines their essential role in the excitation-energy transfer to chlorophyll. The findings of this study demonstrate that diatoms employ fucoxanthin-S to harvest energy under the ocean in the absence of long-wavelength sunlight and can provide significant information on the survival strategies of photosynthetic organisms to adjust to their living environment.
Towards Universal Substituent Constants: Relating QTAIM Functional Group Descriptors to Substituent Effect Proxies
Authors: Lefrancois-Gagnon Kevin , Mawhinney Robert
Published: June 2023

Substituents modulate reactions, but are commonly described using proxies to their true properties. Substituent descriptors from the Quantum Theory of Atoms in Molecules are related here to these proxies, which have historically had chemically intuitable effects. Due to the large number of descriptors, multivariate analysis is used to intuit their meaning. Multiple linear regression, Principal Components, and Partial Least Squares Regression analyses highlight that these substituent descriptors contain similar information to the proxies, while being truly substituent properties. Sources of error limiting quantitative reproduction of the proxies data include transferability, experimental accuracy, and solvation issues.
Open Circuit Potential Decay Transients Quantify Non-Equilibrium Local pH During Electrocatalysis
Authors: Surendranath Yogesh , Sauvé Ethan Richard , Tang Bryan Yuk-Wah , Razdan Neil Kanth , Toh Wei Lun , Weng Sophia
Published: June 2023

Many key energy conversion reactions are proton-coupled electron transfer (PCET) reactions that consume or generate protons at electrode surfaces. Thus, catalytic turnover can generate non-equilibrium local pH environments at the surface that differ substantially from that of the bulk. Quantitative insight into the magnitude of this interfacial pH swing is a prerequisite for understanding and designing efficient systems for energy conversion, but is difficult to measure, particularly under high current density operation; with complex gas diffusion electrodes (GDEs); and with membrane-decorated surfaces employed in functional devices. Herein, we develop and validate a general methodology for experimentally quantifying interfacial pH swings using open circuit potential (OCP) decay transients. Using this method, we quantify the impact of buffer strength, supporting electrolyte composition, and the presence of cation exchange polymer overlayers on the polarization-induced pH swing on Pt GDEs. We find that modest current densities of −30 mA cm−2 are sufficient to sustain pH swings of > 2 pH units, even for strongly buffered solutions. Meanwhile, the addition of alkali supporting electrolyte to unbuffered, acidic electrolyte can induce pH swings so large that the polarized electrode environment becomes strongly alkaline. The presence of a Nafion polymer overlayer containing fixed anionic charges serves to further augment the interfacial pH swing, resulting in a similar pH swing at half the applied current density. The transport characteristics of these systems were analytically modelled, enabling direct calculation of boundary layer thickness and quantitative prediction of the OCP decay transient. These studies establish methods for quantifying local pH swings and highlight the dramatic variation in local pH relative to the bulk under many electrolyte conditions.