bluuebunny/crossref_metadata_2025 huggingface dataset:
Tren Healing di Instagram: Penyembuhan Kekinian di Kalangan Mahasiswa
Authors: Halijah Nur
Published: January 2024

Healing has become a trended term on Instagram since Covid-19. In 2022, there were a sharp increase of searching for the word “healing” in the Google search engine as compared to 2021. The search for “healing” itself refers more to healing in the sense of traveling, which include holiday. This is due to the fact that during Covid-19 pandemic people stayed at home which caused boredom and stress, so it needs some kind of refresh, popularly known as healing. While most of literatures on healing focus more on the impact of healing, the novel contribution of this article is the importance of posting students’ healing activities in social media.
This study was conducted virtually through Instagram since healing caption and healing hashtags (#healing) are widely posted on Instagram. There were 12 students involved in this study, consisting of seven women and five men, whose age ranges between 18 and 21 years, and who are quite active and intensive in healing and posting them on Instagram. Data was collected using interview through chatting and voice note in Instagram and Whatsapp; and observation was carried out by searching for and following #healing.
The study shows that healing means the process of curing. In current practice, students interpret healing as: (1) taking a break from activities that cause stress (2) taking a vacation to reduce psychological burden; and (3) “sedative” from various mental tensions. The way they interpret healing is reflected in the healing-related activities they undertake. They are hang-outing in coffee shops/cafés with friends, climbing cool mountains, enjoying the beauty of the beach, exercising, or motorbiking without a clear destination or going to places that can soothe the soul. In essence, whatever activity is carried out for recuperation, this can be categorized as healing. The underlying reason for students to post their healing activities is to promote tourist destinations; as a platform for expressing oneself; and to save immortalized moments considering that Instagram has its archiving facilities. Therefore, Instagram, in this context, is a platform to make this happen.
ANALISIS KUALITAS BITUMEN DI TAMBANG KABUNGKA PIT B PT. WIJAYA KARYA BITUMEN SULAWESI TENGGARA
Authors: Asriani Asriani , Salmawati Siti , Khadijah Khadijah
Published: January 2024

Bitumen di tambang B Kabungka PT. Wijaya Karya Bitumen yang secara administratif berlokasi di desa Banabugi kecamatan Pasarwajo kabupaten Buton provinsi Sulawesi Tenggara telah dikarakterisasi untuk mengetahui kualitas bitumennya. Kualitas yang dianalisis berupa kadar bitumen menggunakan metode Shoklet dan kadar air menggunakan metode Denstrak serta perhitungan densitas aspal dengan menerapkan prinsip Archimedes. Hasil pengujian untuk enam titik yang berbeda diperoleh kadar air dan kadar bitumen secara berturut-turut sebesar 5,20% dan 17,08%, 9,00% dan 12,81%, 9,60% dan 14,95%, 13,60% dan 16,11%, 7,80% dan 22,36%, serta 5,00% dan 23,90%. Selanjutnya densitas bitumen diketahui sebesar 1,83 gr/ml yang diperoleh melalui pengukuran volume dan massa masing-masing sebanyak dua kali pengukuran untuk setiap titik penambangan. Secara umum, berdasarkan karakterisasi yang dilakukan diketahui bahwa kualitas bitumen memenuhi standar perusahaan, yakni maksimal 16% untuk kadar air dan minimal 20% untuk kadar bitumen. Dengan demikian, bitumen yang terdapat di Tambang B Kabungka PT. Wijaya Karya Bitumen layak untuk dipasarkan.
IDENTIFIKASI UNSUR TANAH LITOSOL DENGAN METODE XRF (X-RAY FLUORESCENCE) DAN FTIR (FOURIER TRANSFORM INFRA RED) BERDASARKAN TITIK ELEVASI DI DESA SAMANGKI KECAMATAN SIMBANG KABUPATEN MAROS
Authors: Jumardin Jumardin , Rizal Andi Syam , Minarti Minarti , Thariq Abdul Munim , Turayni Nurhafida , Wahyullah Wahyullah
Published: January 2024

XRF method to determine elemental content and FTIR test to determine the nature of chemical compounds (functional groups) of Litosol soil at the slope (elevation angle) and the distance of the research trajectory lines. The identified elemental levels are Fe, Si, Ti, K, Mn and Ca. Fe represents the highest elemental content value for each research path. Fe for paths (1-2) are 23.82 % and 37.69%, tracks (5-6) are 23.11% and 37.47%, and paths (9-10) are 40.44% and 33.99% at different elevation angles. The lowest element level is Ca. The value of Ca for each track is 0.24% and 0.66% (1-2), 0.28% and 0.30% (5-6) and 0.27% and 0.62% (9-10) for each different elevation angle. The FTIR method to determine functional groups (chemical compounds) uses the same parameters as the XRF method. The O-H functional groups were detected at wave numbers 3698.31 cm-1 and 3620.34 cm-1 with the theoretical accuracy ranges of 3700-3000 cm-1 and 3590-3650 cm-1. The C=C which is a double bond functional group was detected at wave number 1640.8 cm-1 in the theoretical range of 1610-1680 cm-1. The C-H functional group on each track was detected in three different types of wave numbers with values of 908.99 cm-1, 786.86 cm-1 and 746 cm-1, respectively. The range of wave number accuracy for C-H is 690-900 cm-1.
PENGEMBANGAN PERANGKAT PEMBELAJARAN YANG BERFOKUS PADA CONTEXTUAL TEACHING AND LEARNING UNTUK MENINGKATKAN KETERAMPILAN BERPIKIR KRITIS PESERTA DIDIK
Authors: Sulaiman Ayu Zulpiah , Afdalia Afdalia , Rosita Rosita , Anggriani Sri
Published: January 2024

Penelitian ini merupakan suatu usaha penelitian dan pengembangan dengan tujuan utama yakni (i) pengembangan perangkat pembelajaran yang berfokus pada contextual teaching and learning, (ii) mengevaluasi peningkatan kemampuan berpikir kritis siswa setelah mendapatkan pengajaran menggunakan perangkat yang dikembangkan, dan (iii) menilai respon siswa terhadap perangkat pembelajaran tersebut. Komponen perangkat pembelajaran yang dihasilkan mencakup Rencana Pelaksanaan Pembelajaran (RPP), Bahan Ajar Peserta Didik (BAPD), dan Lembar Kegiatan Peserta Didik (LKPD). Proses pengembangan perangkat pembelajaran ini mengikuti model yang telah dirumuskan oleh Kemp, Morisson, dan Ross yang terdiri dari sembilan unsur pengembangan, antara lain masalah pembelajaran, karakteristik siswa, analisis tugas, tujuan pembelajaran, urutan materi, strategi pembelajaran, penyampaian pembelajaran, instrumen evaluasi, dan sumber pembelajaran. Uji coba perangkat pada siswa kelas XI IPA1 di SMA Negeri 6 Pinrang. Hasil analisis data menunjukkan bahwa (i) pengembangan perangkat pembelajaran yang berfokus pada contextual teaching and learning, termasuk Rencana Pelaksanaan Pembelajaran, Modul Pembelajaran, dan Lembar Kegiatan Peserta Didik dinyatakan valid dan reliabel; (ii) terdapat peningkatan signifikan pada keterampilan berpikir kritis siswa, dengan nilai peningkatan sebesar 0,42, yang dapat dikategorikan sebagai peningkatan sedang; (iii) respon siswa terhadap perangkat pembelajaran dan pelaksanaan kegiatan pembelajaran sangat positif, dengan 84,79% berada dalam kategori sangat positif.
Management Information Systems and Correlation Between E-Business and Information Security from a Business Intelligence Perspective
Authors: El Qasemy Hajar
Published: January 2024

The research focus was motivated by the emergence of electronic business which increased during and after the COVID-19 pandemic. The research is a literature review and its purpose is to build awareness about the importance of information security and to analyze the correlation between information security and electronic business in an environment where electronic business is emerging and the gap between electronic business and information security is enlarging. The research is a review of peer-reviewed articles retrieved from case studies, empirical research, case analysis, literature reviews, comparative studies, systematic reviews, and conceptual analysis dating from the years of 2018 to 2023. This literature review defines four business intelligence concepts: management information systems, value driven business, electronic business, and information security. This literature review also reveals the effects of all four business intelligence concepts on organizations’ decision-making and financial objectives. Findings of this literature review revealed that electronic businesses need a stronger risk management approach regarding information security. The conclusion shows that the current technological approach and information security tools such as encryption key management, mantraps, and network intrusion detection systems do not ensure trust and/or eliminate digital security risks.
Genetic Variant rs1800795 (G>C) in the Interleukin 6 (IL6) Gene and Susceptibility to Coronary Artery Diseases, Type 2 Diabetes, Acute Pancreatitis, Rheumatoid Arthritis, and Bronchial Asthma in Asians: A Comprehensive Meta-Analysis Based on 30154 Subjects
Authors: Harun-Or-Roshid Md. , Mollah Md. Nurul Haque , Jesmin
Published: January 2024

Numerous studies conducted globally have explored the possible connection between the IL6 gene variant rs1800795 (G>C) and the risk of several diseases. Nonetheless, the correlation specifically within the Asian population remains inconclusive. Hence, this extensive meta-analysis aims to establish a conclusive correlation between the rs1800795 variant and susceptibility to various diseases among Asians. Fifty eligible articles were chosen from Google Scholar, PubMed, Web of Science, and PMC based on specific inclusion criteria. Odds ratios alongside 95% confidence intervals (CI) were utilized. Additionally, subgroup analysis, publication bias, and sensitivity evaluation were conducted. The analysis, of 14,737 cases and 15,417 controls, showed a notable correlation between the rs1800795 (G>C) single-nucleotide polymorphism and the overall disease susceptibility to all models (p-value <2.5E-05). The ethnicity-specific stratified findings indicated that the C-allele of (C vs. G) model of −174G/C polymorphism expressively elevated the overall disease susceptibility in both East and South Asian populations. The disease-based stratified analyses suggested that the C variant of rs1800795 was related to coronary artery diseases and bronchial asthma (under all models), type 2 diabetes (CG vs. GG), acute pancreatitis (AP) (C vs. G; and CC vs. GG), rheumatoid arthritis (CC+CG vs. GG; CC vs. CG+GG; and C vs. G), and AP (C or CC vs. G or GG respectively). IL6 rs1800795 polymorphism is a highly significant disease risk factor in Asians and can potentially serve as a prognostic biomarker for future disease screening and evaluation.
 
Received: 3 November 2023 | Revised: 18 December 2023 | Accepted: 31 December 2023
 
Conflicts of Interest
The authors declare that they have no conflicts of interest to this work.
 
Data Availability Statement
The data that support this work are available upon reasonable request to the corresponding author.
Orta Afrika’da Güvenlik Sorunları ve Devlet Dışı Silahlı Aktörler: Boko Haram Örneği
Authors: MOHAMADOU Amınou
Published: January 2024

Bu çalışmanın amacı, Boko Haram terör örgütü ve Orta Afrika’da bölgesel güvenlik sorunlarının ortaya çıkmasındaki temel faktörleri, güvenlik sorunlarını, küresel ve bölgesel aktörlerin yaklaşımını analiz etmektir. Boko Haram, özellikle Nijerya’da faaliyet gösteren bir terör örgütüdür ve yıllar içinde Orta Afrika bölgesine genişleyerek bölgesel güvenlik endişelerini artırmıştır. Sınırların geçişkenliği, yoksulluk, işsizlik, devlete karşı güvensizlik ve bölgesel terörist gruplar arasındaki bağlantılar, örgütün Orta Afrika’da yayılmasının temel faktörleridir. Bu yayılma, kitlesel nüfus yer değiştirmelerine, ekonomik bozulmalara ve topluluklar arası gerilimlere yol açmıştır. Birleşmiş Milletler (BM) ve Orta Afrika Ülkeleri Ekonomik Topluluğu (Economic Community of Central African States – ECCAS) gibi küresel ve bölgesel aktörler, Boko Haram’a karşı istihbarat ve güvenlik iş birliğini artırmış ve uluslararası düzeyde çeşitli ortaklıklar kurulmuştur. Ancak, Boko Haram’ın Orta Afrika’da oluşturduğu tehdit, bölgesel ve uluslararası düzeyde koordineli bir mücadeleyi gerektirmektedir. Bu tehdide karşı yapılan askeri operasyonlarla birlikte, uzun vadeli istikrar için yoksulluk, eğitimsizlik ve çatışmanın nedenleriyle mücadele edilmesi stratejik öneme sahiptir.
Utilization of Chitosan from Fresh Water Lobster (Cherax quadricarinatus) Shells in Anti-Acne Gel Preparations
Authors: Ridwanto Ridwanto , Rosa Vici Delvio , Rani Zulmai , Fauzi Ziza Putri Aisyia
Published: January 2024

Cutibacterium acnes is one of the bacteria that cause acne on the face. Freshwater crayfish (Cherax quadricarinatus) shells have been abandoned and are not used by the community; thus, their shells are processed into economically valuable compounds such as chitosan. Chitosan has antibacterial characteristics that can inhibit acne bacterial development. The purpose of this study is to see if chitosan derived from crayfish shells may be stable in the form of an anti-acne gel and has antibacterial action against Cutibacterium acnes. Anti-acne gel was made from crayfish shells at concentrations of 2, 4 and 6 %, then gel formulations were evaluated and antibacterial efficacy against Cutibacterium acnes germs was tested. Chitosan produced by freshwater lobster shells was 68.75 %. The results of the test of freshwater crayfish shells against Cutibacterium acnes revealed that the average diameter of the inhibition was 6.34 mm at a concentration of 2 %, 6.57 mm at a concentration of 4 % and 6.90 mm at a concentration of 6 %; thus, a concentration of 6 % has the best inhibition. According to the organoleptic test, there was no change in shape or color. According to the homogeneity test, there are no lumps or coarse grains. According to the spreadability test, all preparations were within a 56 cm range. The adhesion test shows a satisfactory adhesion time of more than 1 s. The pH test revealed that all preparations were within the normal skin pH range, indicating that the recipe satisfied the specifications. Anti-acne gel prepared from the shell of a freshwater crayfish displays antibacterial action against Cutibacterium acnes as a cause of acne, with an inhibitory diameter of 6.11 mm at 2 % concentration, 6.8 mm at 4 % concentration and 7.11 mm at 6 % concentration. The diameter of the inhibitory zone in the positive control was 11.9 mm.
HIGHLIGHTS

Freshwater crayfish shells against Cutibacterium acnes revealed that the average diameter of the inhibition was 6.34 mm at a concentration of 2 %, 6.57 mm at a concentration of 4 %, and 6.90 mm at a concentration of 6 %; thus, a concentration of 6 % has the best inhibition
Anti-acne gel prepared from the shell of a freshwater crayfish displays antibacterial action against Cutibacterium acnes as a cause of acne, with an inhibitory diameter of 6.11 mm at 2 % concentration, 6.8 mm at 4 % concentration, and 7.11 mm at 6 % concentration. The diameter of the inhibitory zone in the positive control was 11.9 mm

GRAPHICAL ABSTRACT
Surgical treatment and recurrence of preauricular sinus over a 15-year period at the Clinic of Children Otorhinolaryngology of the MFCU and the NICD in Bratislava
Authors: Chovanová Jana , Šebová Irina
Published: January 2024

Summary Introduction: Preauricular sinus (PAS) is a congenital defect of soft tissue located in the preauricular region. Its manifestation usually occurs when the sinus is infected but there is a possibility that preauricular sinus will not manifest at all. Surgical drainage is indicated in case of abscess formation. Complete extirpation is the method of choice in case of acute infection or long-lasting secernation from sinus. Failure to completely excise preauricular sinus is a common complication of the surgical intervention. The aim of this article is to get familiar with PAS, analyze group of observed patients and evaluate risk factors leading to recurrence of PAS. Material and methods: We evaluated a group of 55 patients with the PAS diagnosis (55 surgical extirpations PASS, N = 55) who underwent surgery at the Department of children otorhinolaryngology of MFCU and NICD during 15-years long period. It is retrospective analysis that is focused on surgical intervention and PAS recurrence. Results: In the observed group of patients (N = 55), 49 patients (89.09%) fully healed without any recurrence and 6 patients (10.91%) had a PAS recurrence. Conclusion: The most of PAS recurrences are results of an incomplete extirpation. The main reason for this is problematic identification of the PAS in its entirety. There are factors which lead to lower prevalence of PAS recurrence. They are precise dissection of PAS, an experienced surgeon, surgical procedure in general anaesthesia, identification of PAS in its entirety with all its branches using instillation of methylene blue, using a sondage and microscope, using an extended supra-auricular approach to identify temporal fascia, total removal of all epithelial components of the PAS with extraction of auricular cartilage that adheres to the sinus, prevention of rupture and leaking of a content of the PAS during surgery and reduction of a dead space in the wound using precise suture without drainage. Key words preauricular sinus – abscess – drainage – extirpation – recurrence
Language adaptation of a swallowing assessment tool in non-surgically treated head and neck tumour patients
Authors: Frajková Žofia , Tedla Miroslav
Published: January 2024

Summary Objective: The objective of the study is the language adaptation of the diagnostic tool Dynamic Imaging Grade of Swallowing Toxicity (DIGEST), which aims at the uniform assessment of flexible endoscopic swallowing examination (FEES) in non-surgically treated patients with head and neck tumours. Material and methods: The language adaptation of the original English version of DIGEST-FEES was carried out based on the recommendations of the World Health Organization. The language adaptation consisted of the translation of the tool into the target language, an expert panel evaluating the cultural and linguistic correctness of the translation and back-translation into the original language. Results: Based on a valid translation, a Slovak version of DIGEST-FEES sk was created, which is culturally, linguistically and structurally adapted to Slovak conditions. Conclusion: New diagnostic tool DIGEST-FEES en version 1.1. enables uniform reporting of swallowing deficits in non-surgically treated head and neck tumour patients, and quantified follow-up of swallowing changes over time. Key words diagnostic procedures – dysphagia – head and neck tumours
En el corazón de la migración: la sociología (política) de las emociones de hombres mexicanos deportados
Authors: De Almeida Arão Galhardi Renato
Published: January 2024

Este artículo examina el papel de las emociones en las experiencias migratorias de hombres mexicanos deportados en Tijuana. Desde una discusión sobre la indivisibilidad de las emociones en la construcción social de la realidad, resalto la importancia de corporeizar el análisis migratorio a través de las emociones. Para migrantes y deportados en una zona fronteriza como Tijuana, las emociones surgen como reacción y en referencia a los procesos biopolíticos de la administración de la frontera; por lo tanto, propongo abordar la fenomenología de experiencias migratorias desde la sociología política de las emociones. Sobre esto, discuto cómo, dónde y de qué forma hombres mexicanos articulan, sitúan e interpretan el papel de las emociones en la construcción del sentido y significado de sus vidas, identidades e ideaciones, desde la condición de la deportación y su situada posición frente a una frontera. Utilizando datos de mi trabajo de campo, realizado entre agosto de 2021 y marzo de 2022, detallo estrategias, expectativas, esperanzas sobresalientes de resistencia y agenciamiento, fundamentadas en la sociología política de las emociones, de vivir en y desde una frontera como un deportado. Concluyo subrayando el carácter político y el papel de las emociones en los procesos migratorios y su participación en el análisis migratorio.
Evaluation of secondary metabolites and antibacterial effect of Boerhavia diffusa roots with chromatographic studies
Authors:   Himalaya wellness company, Dehradun, Chhimwal Suman Lata , Khan Danish , Joshi Anil Kumar
Published: January 2024

India has a vast diversity of medicinal herbs. Around 3,000 years ago, these herbs were acknowledged and used as medicinal plants helpful for treating people. New scientific research has established that some plants and herbs have presence of many active compounds and possess specific pharmacological properties.Boerhavia diffusa is one of the renowned medicinal plants used to treat large number of human ailments as mentioned in Ayurveda. The plant in whole or its peculiar parts (aerial parts and roots) have a numerous medicinal properties. It shows antibacterial, hepato-protective, antistress and also in treatment of stress, abdominal pain, inflammation and jaundice. Various phytochemical, Pharmacological, experimental and clinical investigations were done on Boerhavia diffusa by many scientists to clearly understand the ancient ayurvedic usage of punarnava. The evaluation of secondary metabolites and antibacterial activities of punarnava root extract were investigated on pathogens using the well diffusion method. HPTLC analysis of Boerhavia diffusa extracts were also carried out in different solvent.
Joining of Polymer to Aluminum Alloy AA1050 By Friction Spot Welding
Authors: Osamah Sabah Barrak  , Mahmood Mohammed Hamzah  , Ali Safaa Ali  , Slim Ben-Elechi  , Sami Chatti  , Wasaq Haider Moubder  , Ruba Rasool Radhi  , Arfan Ali Ahmad
Published: January 2024

The friction spot welding process is used to join the hybrid joint of aluminium to polymer. AA 1050 Aluminum alloy and polyethylene polymer (type of plastic) were used for joining. Aluminium surface treatment was done to increase the wettability of it. The surface treatment was done by electrochemical treatment. Two parameters of the joining process were used: (1, 1.5 and 2) min. (920, 1340 and 1500) rpm for time and rotational speed, respectively. Many tests for the joint are done: shear test and Scanning electron microscopy (SEM). Using the Minitab program, the effect of the parameters on the joint was analysed. The maximum value of the shear force was (1587 N) at 1.5 min. time and 1340 rpm rotational speed. The minimum shear force was (589 N) at 1 min. time and 920 rpm rotational speed. The joints which were tested failed by an interfacial shear with a ductile fracture of the polymer side. The process of joining mechanism occurred through a mechanical interlocking between the molten polymer and the surface of the AA 1050 aluminium specimen, cohesive and adhesive. The average thickness for the joint of the tested specimens was 4µm.
CABARAN PEMULIHARAAN HUTAN MELALUI PENDEKATAN PENGLIBATAN KOMUNITI DAN PIHAK BERKEPENTINGAN DI MALAYSIA DAN INDONESIA: TINJAUAN LITERATUR
Authors: Pingking Andreas , Hussin Rosazman
Published: January 2024

Hutan adalah salah satu sumber alam semula jadi yang sangat penting untuk kesejahteraan ekologi, ekonomi dan sosial manusia. Hal ini kerana hutan menyediakan produk kayu dan bukan kayu dan hutan juga menjadi penapis udara serta air yang bersih untuk kehidupan manusia. Jika hutan diuruskan mengikut prinsip pengurusan hutan lestari, maka mengoptimumkan pelbagai fungsinya, termasuk mitigasi perubahan iklim adalah selaras sepenuhnya dengan objektif pemuliharaan hutan untuk pertumbuhan yang mampan (Broadmeadow & Carnus 2009). Namun begitu, penglibatan daripada komuniti dan pihak berkepentingan juga dianggap sangat penting terutamanya dalam proses merancang strategi dan membuat keputusan. Peranan komuniti setempat pula secara jelas adalah untuk memberikan komuniti peluang menguruskan hutan dan memberikan mereka pendidikan berkaitan pengurusan. Penulisan artikel ini adalah bertujuan untuk melihat cabaran yang dihadapi oleh komuniti dan pihak berkepentingan (kerajaan, NGO, Swasta) dalam pemuliharan hutan. Kajian ini juga melihat pengurusan hutan daripada negara Malaysia dan Indonesia disebabkan kedua-dua negara mempunyai landskap serta geografi yang hampir sama. Usaha yang dilaksanakan juga berpandukan kepada Sustainable Development Goals (SDG) dan matlamat yang sama iaitu menjadikan hutan sebagai kawasan yang mampan
CES im Zeichen von KI
Authors: von Rekowski Elke
Published: January 2024

CES 2024: Die Vorteile von künstlicher Intelligenz zeigen sich auch auf der diesjährigen Consumer Electronics Show (CES, 9. bis 12. Januar) in Las Vegas. Selten war neben den vielen technischen Spielereien so viel echter Nutzwert zu sehen. Von Elke von Rekowski
Characteristics and Geoeffectiveness of Small-scale Magnetic Flux Ropes in the Solar Wind
Authors: Kim Myeong Joon , Park Kyung Sun , Lee Dae-Young , Choi Cheong-Rim , Kim Rok Soon , Cho Kyungsuk , Choi Kyu-Cheol , Kim Jaehun
Published: January 2024

Magnetic flux ropes, often observed during intervals of interplanetary coronal mass ejections, have long been recognized to be critical in space weather. In this work, we focus on magnetic flux rope structure but on a much smaller scale, and not necessarily related to interplanetary coronal mass ejections. Using near-Earth solar wind advanced composition explorer (ACE) observations from 1998 to 2016, we identified a total of 309 small-scale magnetic flux ropes (SMFRs). We compared the characteristics of identified SMFR events with those of normal magnetic cloud (MC) events available from the existing literature. First, most of the MCs and SMFRs have similar values of accompanying solar wind speed and proton densities. However, the average magnetic field intensity of SMFRs is weaker (~7.4 nT) than that of MCs (~10.6 nT). Also, the average duration time and expansion speed of SMFRs are ~2.5 hr and 2.6 km/s, respectively, both of which are smaller by a factor of ~10 than those of MCs. In addition, we examined the geoeffectiveness of SMFR events by checking their correlation with magnetic storms and substorms. Based on the criteria Sym-H < -50 nT (for identification of storm occurrence) and AL < -200 nT (for identification of substorm occurrence), we found that for 88 SMFR events (corresponding to 28.5 % of the total SMFR events), substorms occurred after the impact of SMFRs, implying a possible triggering of substorms by SMFRs. In contrast, we found only two SMFRs that triggered storms. We emphasize that, based on a much larger database than used in previous studies, all these previously known features are now firmly confirmed by the current work. Accordingly, the results emphasize the significance of SMFRs from the viewpoint of possible triggering of substorms.
Solar Influence on Tropical Cyclone in Western North Pacific Ocean
Authors: Kim Jung-Hee , Kim Ki-Beom , Chang Heon-Young
Published: January 2024

Solar activity is known to be linked to changes in the Earth’s weather and climate. Nonetheless, for other types of extreme weather, such as tropical cyclones (TCs), the available evidence is less conclusive. In this study the modulation of TC genesis over the western North Pacific by the solar activity is investigated, in comparison with a large-scale environmental parameter, i.e., El-Niño-Southern Oscillation (ENSO). For this purpose, we have obtained the best track data for TCs in the western North Pacific from 1977 to 2016, spanning from the solar cycle 21 to the solar cycle 24. We have confirmed that in the El-Niño periods TCs tend to form in the southeast, reach its maximum strength in the southeast, and end its life as TSs in the northeast, compared with the La-Niña periods. TCs occurring in the El-Niño periods are found to last longer compared with the La-Niña periods. Furthermore, TCs occurring in the El-Niño periods have a lower central pressure at their maximum strength than those occurring in the La-Niña periods. We have found that TCs occurring in the solar maximum periods resemble those in the El-Niño periods in their properties. We have also found that TCs occurring in the solar descending periods somehow resemble those in the El-Niño periods in their properties. To make sure that it is not due to the ENSO effect, we have excluded TCs both in the El-Niño periods and in the La-Niña periods from the data set and repeated the analysis. In addition to this test, we have also reiterated our analysis twice with TCs whose maximum sustained winds speed exceeds 17 m/s, instead of 33 m/s, as well as TCs designated as a typhoon, which ends up with the same conclusions.
Early Phase Contingency Trajectory Design for the Failure of the First Lunar Orbit Insertion Maneuver: Direct Recovery Options
Authors: Song Young-Joo , Bae Jonghee , Kim Young-Rok , Kim Bang-Yeop
Published: January 2024

To ensure the successful launch of the Korea pathfinder lunar orbiter (KPLO) mission, the Korea Aerospace Research Institute (KARI) is now performing extensive trajectory design and analysis studies. From the trajectory design perspective, it is crucial to prepare contingency trajectory options for the failure of the first lunar brake or the failure of the first lunar orbit insertion (LOI) maneuver. As part of the early phase trajectory design and analysis activities, the required time of flight (TOF) and associated delta-V magnitudes for each recovery maneuver (RM) to recover the KPLO mission trajectory are analyzed. There are two typical trajectory recovery options, direct recovery and low energy recovery. The current work is focused on the direct recovery option. Results indicate that a quicker execution of the first RM after the failure of the first LOI plays a significant role in saving the magnitudes of the RMs. Under the conditions of the extremely tight delta-V budget that is currently allocated for the KPLO mission, it is found that the recovery of the KPLO without altering the originally planned mission orbit (a 100 km circular orbit) cannot be achieved via direct recovery options. However, feasible recovery options are suggested within the boundaries of the currently planned delta-V budget. By changing the shape and orientation of the recovered final mission orbit, it is expected that the KPLO mission may partially pursue its scientific mission after successful recovery, though it will be limited.
Limitations of Electromagnetic Ion Cyclotron Wave Observations in Low Earth Orbit
Authors: Hwang Junga , Kim Hyangpyo , Park Jaeheung , Lee Jaejin
Published: January 2024

Pc1 pulsations are geomagnetic fluctuations in the frequency range of 0.2 to 5 Hz. There have been several observations of Pc1 pulsations in low earth orbit by MAGSAT, DE-2, Viking, Freja, CHAMP, and SWARM satellites. However, there has been a clear limitation in resolving the spatial and temporal variations of the pulsation by using a single-point observation by a single satellite. To overcome such limitations of previous observations, a new space mission was recently initiated, using the concept of multi-satellites, named the Small scale magNetospheric and Ionospheric Plasma Experiments (SNIPE). The SNIPE mission consists of four nanosatellites (~10 kg), which will be launched into a polar orbit at an altitude of 600 km (TBD) in 2020. Four satellites will be deployed in orbit, and the distances between each satellite will be controlled from 10 to 1,000 km by a highend formation-flying algorithm. One of the possible science targets of the SNIPE mission is observing electromagnetic ion cyclotron (EMIC) waves. In this paper, we report on examples of observations, showing the limitations of previous EMIC observations in low earth orbit, and suggest possibilities to overcome those limitations through a new mission.
Solar Insolation Effect on the Local Distribution of Lunar Hydroxyl
Authors: Kim Suyeon , Yi Yu , Hong Ik-Seon , Sohn Jongdae
Published: January 2024

Moon mineralogy mapper (M3)'s work proved that the moon is not completely dry but has some hydroxyl/water. M3’s data confirmed that the amount of hydroxyl on the lunar surface is inversely related to the measured signal brightness, suggesting the lunar surface is sensitive to temperature by solar insolation. We tested the effect of solar insolation on the local distribution of hydroxyl by using M3 data, and we found that most craters had more hydroxyl in shade areas than in sunlit areas. This means that the local distribution of hydroxyl is absolutely influenced by the amount of sunshine. We investigated the factors affecting differences in hydroxyl; we found that the higher the latitude, the larger the difference during daytime. We also measured the pyroxene content and found that pyroxene affects the amount of hydroxyl, but it does not affect the difference in hydroxyl between sunlit and shaded areas. Therefore, we confirmed that solar insolation plays a significant role in the local distribution of hydroxyl, regardless of surface composition.
Conceptual Design of Life-Detecting Experiment for Future Europa Lander Mission
Authors: Park Nuri , Yi Yu
Published: January 2024

A previous exo-terrestrial life-detecting experiment, which was conducted on Mars, sought to detect the products of glucose metabolism, the most common biological process on Earth (Viking biological experiment). Today, glucose metabolism is not considered the universal process of life survival. As NASA plans to launch an orbiter mission in the near future (2020s, the Clipper) and ultimately conduct a lander mission on Europa, a detection experiment that can give broader information regarding habitability is highly required. In this study, we designed a life-detecting experiment using a more universal feature of life, the amphipathic molecular membrane, theoretically considering the environment of Europa (waterdominant environment). This designed experiment focuses on finding and profiling hydrophobic cellular membrane-like microstructures. Expected results are given by conceptual data analysis with plausible hypothetical samples.
Unusual Radar Echo from the Wake of Meteor Fireball in Nearly Horizontal Transits in the Summer Polar Lower-Thermosphere
Authors: Lee Young-Sook , Kirkwood Sheila , Kwak Young-Sil
Published: January 2024

The summer polar lower thermosphere (90–100 km) has an interesting connection to meteors, adjacent to the mesopause region attaining the lowest temperature in summer. Meteors supply condensation nuclei for charged ice particles causing polar mesospheric summer echoes (PMSE). We report the observation of meteor trail with nearly horizontal transit at high speed (20–50 km/s), and at last with re-enhanced echo power followed by diffusive echoes. Changes in phase difference between radar receivers aligned in meridional and zonal directions are used to determine variations in horizontal displacements and speeds with respect to time by taking advantage of radar interferometric analysis. The actual transit of echo target is observed along the straight pathway vertically and horizontally extended as much as a distance of at least 24 km and at most 29 km. The meteor trail initially has a signature similar to ‘head echoes’, with travel speeds from 20 – 50 km/s. It subsequently transforms into a different type of echo target including specular echo and then finally the power reenhanced. The reenhancement of echo power is followed by fume-like diffusive echoes, indicating sudden release of plasma as like explosive process probably involved. We discuss a possible role of meteor-triggered secondary plasma trail, such as fireball embedded with electrical discharge that continuously varies the power and transit speed.
Manual Scaling of Ionograms Measured at Jeju (33.4°N, 126.3°E) Throughout 2012
Authors: Jeong Se-Heon , Kim Yong Ha , Kim Ki-nam
Published: January 2024

The ionosphere has been monitored by ionosondes for over five decades since the 1960s in Korea. An ionosonde typically produces an ionogram that displays radio echoes in the frequency-range plane. The trace of echoes in the plane can be read either manually or automatically to derive useful ionospheric parameters such as foF2 (peak frequency of the F2 layer) and hmF2 (peak height of the F2 layer). Monitoring of the ionosphere should be routinely performed in a given time cadence, and thus, automatic scaling of an ionogram is generally executed to obtain ionospheric parameters. However, an auto-scaling program can generate undesirable results that significantly misrepresent the ionosphere. In order to verify the degree of misrepresentation by an auto-scaling program, we performed manual scaling of all 35,136 ionograms measured at Jeju (33.43°N, 126.30°E) throughout 2012. We compared our manually scaled parameters (foF2 and hmF2) with auto-scaled parameters that were obtained via the ARTIST5002 program. We classified five cases in terms of the erroneous scaling performed by the program. The results of the comparison indicate that the average differences with respect to foF2 and hmF2 between the two methods approximately correspond to 0.03 MHz and 4.1 km, respectively with corresponding standard deviations of 0.12 MHz and 9.58 km. Overall, 36 % of the auto-scaled results differ from the manually scaled results by the first decimal number. Therefore, future studies should be aware of the quality of auto-scaled parameters obtained via ARTIST5002. Hence, the results of the study recommend the use of manually scaled parameters (if available) for any serious applications.
Relative Navigation with Intermittent Laser-based Measurement for Spacecraft Formation Flying
Authors: Lee Jongwoo , Park Sang-Young , Kang Dae-Eun
Published: January 2024

This paper presents relative navigation using intermittent laser-based measurement data for spacecraft flying formation that consist of two spacecrafts; namely, chief and deputy spacecrafts. The measurement data consists of the relative distance measured by a femtosecond laser, and the relative angles between the two spacecrafts. The filtering algorithms used for the relative navigation are the extended Kalman filter (EKF), unscented Kalman filter (UKF), and least squares recursive filter (LSRF). Numerical simulations reveal that the relative navigation performances of the EKF- and UKF-based relative navigation algorithms decrease in accuracy as the measurement outage period increases. However, the relative navigation performance of the UKF-based algorithm is 95 % more accurate than that of the EKF-based algorithm when the measurement outage period is 80 sec. Although the relative navigation performance of the LSRF-based relative navigation algorithm is 94 % and 370 % less accurate than those of the EKF- and UKF-based navigation algorithms, respectively, when the measurement outage period is 5 sec; the navigation error varies within a range of 4 %, even though the measurement outage period is increased. The results of this study can be applied to the design of a relative navigation strategy using the developed algorithms with laser-based measurements for spacecraft formation flying.
Satellite Laser Ranging System at Geochang Station
Authors: Lim Hyung-Chul , Sung Ki-Pyoung , Yu Sung-Yeol , Choi Mansoo , Park Eunseo , Park Jong-Uk , Choi Chul-Sung , Kim Simon
Published: January 2024

Korea Astronomy and Space Science Institute (KASI) has been developing the space optical and laser tracking (SOLT) system for space geodesy, space situational awareness, and Korean space missions. The SOLT system comprises satellite laser ranging (SLR), adaptive optics (AO), and debris laser tracking (DLT) systems, which share numerous subsystems, such as an optical telescope and tracking mount. It is designed to be capable of laser ranging up to geosynchronous Earth orbit satellites with a laser retro-reflector array, space objects imaging brighter than magnitude 10, and laser tracking low Earth orbit space debris of uncooperative targets. For the realization of multiple functions in a novel configuration, the SOLT system employs a switching mirror that is installed inside the telescope pedestal and feeds the beam path to each system. The SLR and AO systems have already been established at the Geochang station, whereas the DLT system is currently under development and the AO system is being prepared for testing. In this study, the design and development of the SOLT system are addressed and the SLR data quality is evaluated compared to the International Laser Ranging Service (ILRS) tracking stations in terms of single-shot ranging precision. The analysis results indicate that the SLR system has a good ranging performance, to a few millimeters precision. Therefore, it is expected that the SLR system will not only play an important role as a member of the ILRS tracking network, but also contribute to future Korean space missions.
Experimental Study of Spacecraft Pose Estimation Algorithm Using Vision-based Sensor
Authors: Hyun Jeonghoon , Eun Youngho , Park Sang-Young
Published: January 2024

This paper presents a vision-based relative pose estimation algorithm and its validation through both numerical and hardware experiments. The algorithm and the hardware system were simultaneously designed considering actual experimental conditions. Two estimation techniques were utilized to estimate relative pose; one was a nonlinear least square method for initial estimation, and the other was an extended Kalman Filter for subsequent on-line estimation. A measurement model of the vision sensor and equations of motion including nonlinear perturbations were utilized in the estimation process. Numerical simulations were performed and analyzed for both the autonomous docking and formation flying scenarios. A configuration of LED-based beacons was designed to avoid measurement singularity, and its structural information was implemented in the estimation algorithm. The proposed algorithm was verified again in the experimental environment by using the Autonomous Spacecraft Test Environment for Rendezvous In proXimity (ASTERIX) facility. Additionally, a laser distance meter was added to the estimation algorithm to improve the relative position estimation accuracy. Throughout this study, the performance required for autonomous docking could be presented by confirming the change in estimation accuracy with respect to the level of measurement error. In addition, hardware experiments confirmed the effectiveness of the suggested algorithm and its applicability to actual tasks in the real world.
Characteristics of Relative Navigation Algorithms Using Laser Measurements and Laser-GPS Combined Measurements
Authors: Kang Dae-Eun , Park Sang-Young , Son Jihae
Published: January 2024

This paper presents a satellite relative navigation strategy for formation flying, which chooses an appropriate navigation algorithm according to the operating environment. Not only global positioning system (GPS) measurements, but laser measurements can also be utilized to determine the relative positions of satellites. Laser data is used solely or together with GPS measurements. Numerical simulations were conducted to compare the relative navigation algorithm using only laser data and laser data combined with GPS data. If an accurate direction of laser pointing is estimated, the relative position of satellites can be determined using only laser measurements. If not, the combined algorithm has better performance, and is irrelevant to the precision of the relative angle data between two satellites in spherical coordinates. Within 10 km relative distance between satellites, relative navigation using double difference GPS data makes more precise relative position estimation results. If the simulation results are applied to the relative navigation strategy, the proper algorithm can be chosen, and the relative position of satellites can be estimated precisely in changing mission environments.
Observational Arc-Length Effect on Orbit Determination for KPLO Using a Sequential Estimation Technique
Authors: Kim Young-Rok , Song Young-Joo , Bae Jonghee , Choi Seok-Weon
Published: January 2024

In this study, orbit determination (OD) simulation for the Korea Pathfinder Lunar Orbiter (KPLO) was accomplished for investigation of the observational arc-length effect using a sequential estimation algorithm. A lunar polar orbit located at 100 km altitude and 90° inclination was mainly considered for the KPLO mission operation phase. For measurement simulation and OD for KPLO, the Analytical Graphics Inc. Systems Tool Kit 11 and Orbit Determination Tool Kit 6 software were utilized. Three deep-space ground stations, including two deep space network (DSN) antennas and the Korea Deep Space Antenna, were configured for the OD simulation. To investigate the arc-length effect on OD, 60-hr, 48-hr, 24-hr, and 12-hr tracking data were prepared. Position uncertainty by error covariance and orbit overlap precision were used for OD performance evaluation. Additionally, orbit prediction (OP) accuracy was also assessed by the position difference between the estimated and true orbits. Finally, we concluded that the 48-hr-based OD strategy is suitable for effective flight dynamics operation of KPLO. This work suggests a useful guideline for the OD strategy of KPLO mission planning and operation during the nominal lunar orbits phase.
A war is a war is a war: Na Medida do Impossível, de Tiago Rodrigues
Authors: Catarino Beatriz
Published: January 2024

Crítica ao espectáculo Na medida do impossível.
UJI KOMPARASI VOLUME MESIN BAKAR TERHADAP BAHAN BAKAR YANG DIGUNAKAN
Authors: Achmadin Wahyu Nur , Dewi Indah Noor Dwi Kusuma , Prasetiyo Dani Hari Tunggal , Swari Utami Ratna , Defriatno Mawan Eko
Published: January 2024

Uji komparasi mesin bakar bervolume 110 cc dengan mesin bakar bervolume 125 cc telah dilakukan. Bahan bakar yang digunakan pada penelitian ini adalah jenis pertamax turbo. Penelitian ini bertujuan untuk mengetahui perbandingan yang terjadi pada mesin bakar bervolume berbeda dengan menggunakan bahan bakar yang sama. Metode yang digunakan adalah menganalisa nilai daya tertinggi pada masing-masing mesin bakar pada putaran mesin. Penelitian ini memberikan hasil bahwa daya terbesar pada masing-masing mesin bakar yang diuji terletak pada putaran 7000 rpm, dengan mencapai 12 hp pada mesin bakar volume 110 cc serta 7,4 hp pada mesin bakar volume 125 cc. Hasil yang diperoleh adalah daya yang dihasilkan pada mesin bakar bervolume 110 cc lebih besar dibandingkan dengan mesin bakar bervolume 125 cc. Hal ini disebabkan volume yang bekerja pada mesin mempengaruhi jumlah beban pembakaran yang terjadi di mesin bakar
ANALISIS PENYIMPANGAN GEOMETRI PICK ARM PADA PROSES BORING CNC Milling
Authors: Arrohman Sigit , Antonio Dafit
Published: January 2024

Proses pembuatan Pick Arm menggunakan proses repair id eye. Proses repair id eye pada pick arm menggunakan proses boring yaitu proses pembuatan lubang sesuai dengan keinginan dengan memperhatikan penyimpangan geometri dari id eye pick arm. Penelitian ini menggunakan variasi kedalaman pemotongan sebesar 1 mm, 2mm, dan 3mm. Putaran spindle dengan 3 variasi kecepatan yaitu 300 rpm, 400 rpm, dan 500 rpm. Kecepatan pemakanan 0,1 mm/s. Diameter pick arm sebesar 32 mm. dalam pengukuran dimensi dan penyimpangan geometri pick arm menggunakan jangka sorong. Adapun toleransi hasil boring id eye pick arm ± 0,014 mm. pengambilan pengukuran memperhatikan 4 sumbu pengukuran yaitu X, Y, x’ dan y’. Hasil penelitian ini berupa penyimpangan geometri pick arm terbesar terjadi pada kedalaman potong 1mm dan dengan kecepatan spindle 500 rpm yaitu 0,06 mm yang melebihi dari batas toleransi ± 0,014 mm. Sedangkan hasil yang mendekati nilai batas toleransi adalah 0,12 mm pada kedalaman potong 1 mm dan kecepatan spindle 300 rpm. Kesimpulan dari penelitian ini adalah semakin dalam pemotongan dan besarnya putaran spindle memberikan hasil penyimpangan geometri yang besar.