bluuebunny/crossref_metadata_2025 huggingface dataset:
PENGARUH JARAK TURBIN ANGIN SAVONIUS TIPE-U SUMBU VERTIKAL DENGAN SUMBER BUANGAN ANGIN EXHAUST FAN KITCHEN TERHADAP UNJUK KERJA PROTOTIPE PEMBANGKIT LISTRIK TENAGA BAYU
Authors: Dharma Pawitra Ida Bagus Gede , Arta Wijaya I Wayan , Janardana I Gusti Ngurah
Published: January 2024

Energy needs in Indonesia are increasing, especially in the realization of electricity consumption which reached 20.18 TWh in July 2020. Using exhaust wind energy from exhaust fans as an alternative source of wind energy is considered quite effective because the characteristics of the wind produced are stable. The method used in This research is quantitative and the purpose of this research is to get the optimal distance from the vertical axis of the savonius wind turbine to the exhaust fan. Setting the distance of the turbine is done by adjusting the position of the wind turbine to the exhaust fan with 4 test distances, namely 10 cm, 20 cm, 30 cm and 50 cm. The results of this study are a distance of 10 cm with a 40 ohm load, the output power is 1.74 watts with an efficiency of 23%, an 80 ohm load, the output power is 1.4 watts with an efficiency of 18%, a 120 ohm load, the output power is 1.215 watts with an efficiency of 16%. , a 160 ohm load produces 0.91 watts of output power with an efficiency of 12%, a 200 ohm load produces 0.91 watts of output power with an efficiency of 12%. distance of 50 cm 40 ohm load output power generated 0.4 watts with 11% efficiency, 80 ohm load output power generated 0.19 watts with 5% efficiency, 120 ohm load output power generated 0 watts with 0% efficiency, 160 ohm load power the output is 0 watts with 0% efficiency, a 200 ohm load produces 0 watts output power with 0% efficiency, so the optimal distance for placing the turbine is 10 cm.
POTENSI PEMBANGKIT LISTRIK TENAGA MIKROHIDRO DENGAN TURBIN KAPLAN PADA SUNGAI MAMBAL
Authors: Dwi Lasmana I Kadek Oki , Indra Partha Cokorda Gede , Arta Wijaya I Wayan
Published: January 2024

The Kaplan turbine is a type of reaction turbine that utilizes potential energy to generate motion energy. The Kaplan turbine is very suitable for use in places where the head is low but requires a large discharge. Currently Kaplan turbines are still very little used in Indonesia, especially in Bali. So that it is difficult to obtain specification data relating to Kaplan turbines. Many prototypes are made on a laboratory scale to get maximum results. This study discusses the results of the output voltage, current, power, and efficiency that can be produced by a PLTMH prototype using a Kaplan turbine. This study also discusses the analytical study of the existing hydropower potential, namely, the water flow rate and the height of the water fall (head) of the Mambal River water flow. This prototype test uses a water flow rate of 6 L or 0.006 m^3/s with a guide vane angle of 30 º and a total of 5 runner blades. In the no-load test, the average turbine rotation before being coupled to the generator was 556 rpm, the average turbine rotation after being coupled was 353 rpm. The average result of the largest turbine rotation is 303 rpm, the largest generator rotation result is 499 rpm, the largest generator voltage average result is 5.60 volts, the largest average generator current result is 0.61 Ampere, the result the largest average generator powerKey Words : Prototype of PLTMH, Kaplan Turbine, Water Discharge, Output producedis 1.93 Watt, the largest torque is 0.14 Nm, the largest PLTMH efficiency is 5.1%.
KONTROL FREKUENSI BEBAN MENGGUNAKAN METODE ADAPTIVE NEURO FUZZY INFERENCE SYSTEM (ANFIS) PADA SISTEM HYBRID WIND MIKROHIDRO DAN DIESEL
Authors: Febryanto Simorangkir Walter Willy Metyu , Mataram I Made , Wijaya I Ketut
Published: January 2024

This study aims to analyze and compare the performance of three frequency load controller methods in a hybrid generator consisting of three types of energy generation, namely microhydro, diesel and wind. The controller methods being compared are the PID (Proportional Integral Derivative) method, ANFIS (Adaptive Neuro-Fuzzy Inference System), and Fuzzy. This analysis was carried out to improve the efficiency and stability of the hybrid generating system by optimizing the frequency load controller. Frequency instability can occur due to load fluctuations, changes in environmental conditions, or system disturbances. Therefore, the use of an effective and adaptive controller method is very important in maintaining the stability and reliability of the hybrid generator system. The analytical method used in this study involved data collection and computer modeling. The required data includes information on load variations, energy production, and environmental conditions. Furthermore, the PID, ANFIS, and Fuzzy methods are applied to the data to build a frequency load controller model. The results of the analysis show that the three controller methods have different performance in maintaining frequency stability in the hybrid generator system. The PID method provides a fast and accurate response to load fluctuations, but is less adaptive to environmental changes. While the ANFIS method is able to adapt well to changes in system conditions, it requires time for model training. Fuzzy methods can provide control that is more adaptive and tolerant to disturbances, but may require more complex tuning. However, in general, the use of intelligent controller methods such as ANFIS and Fuzzy can improve the performance of hybrid generators by producing more adaptive and stable controls. This research has important implications for the development of more efficient and reliable hybrid power systems. By choosing the right controller method, hybrid power plants can provide energy in a more stable and environmentally friendly manner, and reduce dependence on limited fossil resources. Therefore, this research can make a significant contribution to the development of renewable energy and sustainable development in the future.
The Impact of Controversial Esg On the Market Value and Financial Constraints of Brics Companies
Authors: Fernandes Caio Guelli , Luna Marcelus Silas de Freitas , Maria Junior Elizeu , Maria Michele Monteiro Lirio
Published: January 2024

Objective: Analyze the relationship between the controversial ESG and the market value and the financing restrictions of companies that make up the BRICS.
 
Method: 403 companies from the capital markets of the BRICS member countries were analyzed from 2017 to 2022, making a total of 2702 total observations. The main analysis of the study was carried out using Panel Data regressions, Pooled model. The main research model tested the relationship between market value and the financial constraints indicator, as dependent variables, and controversial ESG as the main explanatory variable.
 
Results: There was a negative relationship between the controversial ESG score and the market value of the companies analyzed. From this result, it was possible to infer that negative experiences, events and news in relation to ESG practices tend to generate a reduction in the market value of a company, corroborating previous studies and one of the hypotheses of this study. However, the increase in the controversial ESG score was found to reduce the company's financing constraints, differing from expected.
 
Contributions: The practical conclusions of this research point to the importance of companies continuing to analyze in depth the potential negative impacts that controversial ESG can generate in the financial sphere, covering the short, medium and long term. Furthermore, corporate and public policy makers have the opportunity to improve the regulatory structures of both companies and governments regarding the integration of ESG into investment activities. This, in turn, not only helps to avoid a reduction in the market value of companies, but also prevents a decrease in the financing options available to them.
Pengaruh Konten Media Sosial Instagram terhadap Minat Beli Followers Golden Monkey Malatang Hotpot
Authors: Runturambi James , Farid Farid
Published: January 2024

The development of more and more modern technologies has made the development of information technology faster and fasterOne way to counter the competition is to use social media. Instagram social media was chosen as the object of study because it has a greater influence. One sector in the culinary business that is leveraging social media is Golden Monkey Malatang Hotpot, with an Instagram account @Malatang_hotpot. The aim of this study is to find out whether there is an influence of social media content on Instagram @malatang_hotpot on followers' buying interest. The sample size in this study was 100 respondents who are followers of the @malatang_hotpot Instagram account. In this study using explanatory quantitative methods while the samples in this study use a targeted sampling technique. Data collection in this study used an online questionnaire with a Google form. In managing the data in this study using SPSS version 29. The bottom line of this study is the influence of social media content on Instagram @malatang_hotpot on followers' buying interest of 42.7%, while the rest of other factors outside of this study being affected.
Perkembangan teknologi yang semakin modern membuat perkembangan terknologi informasi semakin meningkat pesat. Media sosial Instagram dipilih menjadi objek penelitian karena memiliki pengaruh yang lebih besar. Salah satu sektor di bisnis kuliner yang memanfatkan media sosial adalah Golden Monkey Malatang Hotpot dengan akun instagram @Malatang_hotpot. Tujuan dari penelitian ini adalah untuk mengetahui adakah pengaruh konten sosial media Instagram @malatang_hotpot terhadap minat beli followers. Jumlah sampel dalam penelitian ini sebanyak 100 responden yang merupakan followers akun Instagaram @malatang_hotpot. Didalam penelitian ini menggunakan metode kuantitatif yang bersifat ekplanatif. kemudain pengambilan sampel dalam penelitian ini menggunakan teknik purposive sampling. Pengumpulan data dalam penelitian ini menggunakan kuisioner secara online dengan google form. Dalam mengelola data dalam penelitian ini menggunakan SPSS versi 29. Hasil akhir dari penelitian ini adalah adanya pengaruh konten sosial media Instagram @malatang_hotpot terhadap minat beli followers sebesar 42,7% sedangkan sisanya dipengaruhi oleh faktor lain diluar penelitian ini.
Peran Brand Ambassador Kopi Kekinian untuk Menciptakan Brand Recall Mahasiswa Universitas Tarumanagara
Authors: Hartono Jason Harley , Pribadi Muhammad Adi
Published: January 2024

A brand ambassador is an advertising supporter or also known as an advertising star who supports advertised products to create brand recall of the brand from the promotions being carried out. According to Prashar, brand recall refers to how well consumers do a recall of a brand in various situations. In this study, the selection of the Kopi Kenangan brand as the object of research is because Kopi Kenangan is one of the leading contemporary coffee brands that is popular with the public and often uses the services of Brand Ambassadors in its promotional activities. This study uses a qualitative research approach with the exploratory case method. After conducting research on Kopi Kenangan consumers, the researchers concluded that Kopi Kenangan had followed the Brand Ambassador theory put forward by Rosister and Percy, this was evidenced by the creation of brand recall among Tarumanagara University students because of using brand ambassadors in Kopi Kenangan promotional activities.
Brand ambassadoradalah pendukung iklan atau juga yang dikenal sebagai bintang iklan yang mendukung produk yang diiklankan agar terciptanya brand recall terhadap branddari promosi yang dijalankan. Menurut Prashar, brand recallmerujuk pada seberapa baik konsumen melakukan recall terhadap sebuah merek dalam berbagai situasi. Pada penelitian ini, pemilihan brandKopi Kenangan sebagai objek penelitian karena Kopi Kenangan menjadi salah satu brandkopi kekinian unggulan yang digemari masyarakat serta kerap kali menggunakan jasa brand ambassador dalam kegiatan promosinya. Penelitian ini menggunakan pendekatan penelitian kualitatif dengan metode kasus eksploratoris. Setelah dilakukan penelitian terhadap para konsumen Kopi kenangan, peneliti menyimpulkan bahwa Kopi Kenangan sudah mengikuti teori Brand Ambassador yang dikemukan oleh Rosister dan Percy, hal tersebut dibuktikan dari terciptanya brand recall dikalangan mahasiswa Universitas Tarumanagara sebagai hasil penggunaan brand ambassador dalam kegiatan promosi Kopi Kenangan.
Analisis Motif Perempuan Dewasa Muda dalam Membeli Produk Quby Lamp
Authors: Subandi Jason , Sari Wulan Purnama
Published: January 2024

The Quby Lamp sleeping lamp phenomenon is very popular on social media. To market these products, sellers or buyers recommend each other to other people because the design is unique and the design is very pleasant and the design is very beautiful for tips to like or have. This Quby Lamp product is very popular with all groups, especially young adult women. They are interested because the design of this product is very unique. This research was conducted to obtain an idea of how consumers are interested in purchasing Quby lamp products. In order to obtain these images, the author tries to dig in depth with the sources, namely by conducting interviews with women who are interested in buying a Quby lamp, or those who have purchased a Quby Lamp before. The results of the study show that the factors that build a Quby Lamp purchasing motive are the quality, uniqueness or cuteness of the product, the use of the Quby Lamp. Meanwhile, factors that support purchases are conversations on social media.
Fenomena Quby Lamp lampu tidur gemoi merupakan hal yang sangat populer di media sosial. Untuk memasarkan produk tersebut penjual atau pembeli saling merekomendasikan untuk orang lain karena desain nya yang unik dan desainya yang sangat menyenangkan serta desai yang sangat cantik untuk kiat sukai atau kita miliki. Dengan produk Quby Lamp ini sangat banyak digemari oleh semua kalangan terutama kalangan perempuan dewasa muda. Mereka tertarik karena desain dari produk ini sangat unik. Penelitian ini dilakukan untuk memperoleh gambaran bagaimana konsumen tertarik untuk melakukan pembelian produk Quby lamp. Untuk memperoleh gambar tersebut penulis mencoba menggali narasumber secara mendalam, yakni dengan melakukan wawancara dengan para perempuan yang tertarik untuk membeli Quby lamp, atau mereka yang pernah membeli Quby Lamp. Hasil penelitian menunjukkan faktor yang membangun motif pembelian Quby Lamp adalah kualitas, keunikan ataupun kelucuan produk, kegunaan Quby Lamp. Sedangkan faktor yang mendukung pembelian adalah percakapan atau conversation di media sosial.
Strategi Komunikasi dalam Membangun Kesadaran Merek Marque.Co melalui Media Sosial
Authors: Pranata Jennifer Mia , Junaidi Ahmad
Published: January 2024

Technological developments have had an influence on product promotion efforts, this has also enabled businesspeople to be able to optimize them well. This research focuses on Marque.Co's communication strategy in building brand awareness through social media. Marque.Co was used as the object of research because local products are built with serious effort and prioritize product quality and efforts to provide optimal service to its customers. This research uses a qualitative approach method with primary and secondary data collection techniques. Primary data was carried out by observation and interviews, while secondary data was carried out by literature study. The results show that Marque.Co itself makes efforts to approach communication with its consumers through social media Instagram and TikTok and makes sales through online marketplaces such as Shopee and Tokopedia. The communication strategy carried out was successful in building brand awareness, this is proven by Marque.Co's Instagram followers reaching more than 50,000 and sales of thousands of units on Shopee.

Perkembangan teknologi telah memberikan pengaruh pada upaya promosi produk, hal tersebut pun membuat para pelaku bisnis untuk bisa mengoptimalkannya dengan baik. Penelitian ini memiliki fokus pada strategi komunikasi Marque.Co dalam membangun kesadaran merek melalu media sosial. Marque.Co ini dijadikan objek penelitian karena produk lokal yang dibangun dengan upaya yang serius dan juga mengedepankan kualitas produk serta upaya memberikan pelayanan yang optimal kepada customernya. Penelitian ini menggunakan metode pendakatan kualitatif dengan teknik pengumupulan data primer dan juga sekunder. Data primer dilakukan dengan observasi dan juga wawancara, sedangkan data sekunder dengan studi pustaka. Hasil menujukkan bahwa Marque.Co sendiri melakukan upaya pendekatan komunikasi dengan konsumennya melalui media sosial Instagram dan TikTok, dan melakukan penjualan melalui marketplace online seperti Shopee dan Tokopedia. Strategi komunikasi yang dilakukan berhasil membangun kesadaran merek (brand awareness), hal ini terbukti dari followers Instagram Marque.Co mencapai lebih dari 50.000 dan penjualan dengan jumlah ribuan unit di Shopee.
Strategi Komunikasi Pemasaran Butik Lianepuspita melalui Media Sosial
Authors: Setiawan Jimmy , Junaidi Ahmad
Published: January 2024

Communication is the link of all social interactions. Communication is one of the main keys in the world of marketing. The use of Instagram media sosial as a marketing tool is inseparable from the pattern of community interaction which has shifted from face-to-face communication to virtual communication. The choice of marketing through online media occurs due to several factors such as time and cost efficiency. This study aims to find out how the internet-based marketing communication strategy is implemented by Lianepuspita Boutique in marketing its products both through Instagram and the Marketplace. The data in this study used observation data, interviews, documentation, and internet searching. The data needed includes the promotional strategy implemented by the Lianepuspita Boutique. This type of research uses qualitative research with a case study research approach to the object under study. Lianepuspita Boutique is a kebaya brand that chooses the online route in marketing its products. The results show that the marketing communication strategy carried out by Lianepuspita Boutique uses elements of the marketing mix with a focus on sales promotion on Instagram and Marketplace.

Komunikasi adalah penghubung semua interaksi sosial. Komunikasi merupakan salah satu kunci utama dalam dunia pemasaran. Penggunaan media sosial Instagram sebagai alat pemasaran tidak terlepas dari pola interaksi masyarakat yang bergeser dari komuikasi yang mendapatkan tatap muka ke komunikasi virtual. Pemilihan pemasaran melalui media online terjadi karena beberapa faktor seperti efisiensi waktu dan biaya. Penelitian ini bertujuan mengetahui bagaimana strategi komunikasi pemasaran berbasis internet yang dijalankan oleh Butik Lianepuspita dalam memasarkan produk buatannya baik melalui Instagram dan marketplace. Data dalam penelitian ini mengumpulkan data dengan observasi, wawancara, dokumentasi, dan internet searching. Data yang diperlukan meliputi strategi promosi yang diterapkan Butik Lianepuspita. Pendekatan penelitian ini adalah kualitatif dengan metode studi kasus pada objek yang diteliti. Butik Lianepuspita merupakan brand kebaya yang memilih jalur online dalam memasarkan produk-produknya. Hasil menunjukkan bahwa dalam strategi komunikasi pemasaran yang dilakukan oleh Butik Lianepuspita menggunakan elemen bauran pemasaran dengan fokus pada promosi penjualan di Instagram dan marketplace.
Analisis Strategi Kreatif YouTuber Bangpop
Authors: Pratama Jody Kurniawan , Paramita Sinta
Published: January 2024

The presence of YouTube today greatly influences content creators in the creative industry. Content creators use YouTube as a place to make money, work and also do live streaming. The advantage of YouTube is its ability to quickly disseminate information to the public. Of the many YouTube contents, content playing games is one of the content that is in great demand. One of the YouTubers who creates content for playing this game is Bangpop, a Youtuber from Bandung. In this study, researchers. Want to know how Bangpop's creative strategy is to produce content that is in great demand by the audience. This research approach is qualitative while the method used is a case study. To collect data, an analysis of the content was carried out, and conducted in-depth interviews with Bangpop content creators. In addition, interviews were also conducted with relevant informants to obtain a more complete perspective in the research. The results of this research show that evaluating ideas, namely by creating content based on comments and responses from viewers on live streaming, will make viewers prefer the content produced.

Kehadiran YouTube saat ini sangat memengaruhi content creator di industri kreatif. Content creator menggunakan YouTube sebagai wadah untuk mencari uang, berkarya dan juga melakukan live streaming. Kelebihan YouTube adalah kemampuannya yang dapat dengan cepat menyebarkan informasi kepada masyarakat. Dari banyaknya konten Youtube, konten bermain game adalah salah satu konten yang banyak diminati. Salah satu youtuber yang membuat konten bermain game ini adalah Bangpop, seorang Youtuber asal Bandung. Pada penelitian ini peneliti. Ingin mengetahui bagaimana strategi kreatif Bangpop untuk menghasilkan konten yang banyak diminati oleh penonton. Pendekatan penelitian ini adalah kualitatif sedangkan metode yang digunakan adalah studi kasus. Untuk mengumpulkan data, dilakukan analisis terhadap konten, dan melakukan wawancara mendalam dengan content creator Bangpop. Selain itu dilakukan juga wawancara dengan narasumber yang relevan untuk mendapat perspektif yang lebih lengkap dalam penelitian. Hasil penelitian ini menunjukkan bahwa evaluasi ide yakni dengan membuat konten berdasarkan komentar dan respon dari penonton di live streaming, akan membuat penonton lebih menyukai konten yang diproduksi.
Peran Brand Ambassador Perusahaan E-Sport dalam Menumbuhkan Loyalitas Penggemar
Authors: Wen Kellie , Oktavianti Roswita
Published: January 2024

This research aims to find out about the role of ESport company brand ambassadors in growing fan loyalty. ESports or electronic sports is a term for the competitive world of multi- player video game games or competitions. Meanwhile, brand ambassadors are individuals or groups appointed as icons or identities to represent certain products as the best image representation of a product, so that consumers can be attracted and invited to buy or use the product with expertise and attractiveness. The theory used to support this research is public opinion. This study uses a qualitative method. Data collection in this research used focus group discussion techniques. The subjects of this research were brand ambassador followers and ESport followers on social media. In accordance with the objectives of this research, the author wants to see how public opinion is regarding the role and influence of brand ambassadors in growing fan loyalty for ESport companies. This research shows that the influence of a brand ambassador in building fan loyalty for an E-Sport company is very important. Apart from that, this research shows the importance of visibility, credibility, attraction and brand ambassador power indicators to grow or increase fan loyalty.

Penelitian ini bertujuan untuk mengetahui tentang peran brand ambassador perusahaan ESport dalam menumbuhkan loyalitas penggemar. ESports atau electronic sports adalah sebuah istilah untuk dunia kompetitif dalam game atau kompetisi video game pemain jamak. Sementara Brand ambassador atau duta merek adalah individu atau kelompok yang ditunjuk sebagai ikon atau identitas untuk mewakili produk tertentu sebagai representasi citra terbaik dari suatu produk, sehingga konsumen dapat tertarik dan diundang untuk membeli atau menggunakan produk dengan keahlian dan daya tarik. Teori yang dipakai untuk mendukung penelitian ini adalah opini publik. Penelitian ini menggunakan metode kualitatif. Pengumpulan data pada penelitian ini menggunakan teknik focus group discussion atau diskusi kelompok. Subjek dari penelitian ini adalah pengikut brand ambassador dan pengikut ESport di media sosial. Sesuai dengan tujuan dari dari penelitian ini, maka penulis ingin melihat bagaimana opini publik terhadap peran dan pengaruh brand ambassador dalam menumbuhkan loyalitas penggemar untuk perusahaan ESport. Penelitian ini menunjukkan bahwa pengaruh seorang brand ambassador dalam membangun loyalitas penggemar untuk perusahaan E-Sport sangatlah penting. Selain itu penelitain ini menunjukkan hasil bahwa pentingnya indicator visibility, credibility, attraction, dan power brand ambassador untuk menumbuhkan atau meningkatkan loyalitas penggemar.
Komunikasi Verbal dan Nonverbal Sebagai Basis Layanan Penumpang KAI
Authors: Febrian Louis Alviando Abadi , Erdiansyah Rezi
Published: January 2024

KAI or known as PT. Kereta Api Indonesia is a service provider. KAI provides public transportation services for the needs of the community. In this study, the authors focused on the objective to find out whether the quality of PT. Kereta Api Indonesia in providing services has an influence on the satisfaction of service users of PT. Kereta Api Indonesia both in the process of verbal communication and non-verbal communication. In an effort to achieve the research objectives, in this study qualitative research methods were used as research methods that are in accordance with the service users of PT. Indonesian Railroad as a population and as many as 100 respondents based on the results of the Slovin formula, as the required number of samples. Multiple linear regression, t test, f test and coefficient of determination test are the data analysis techniques used in this study. Based on the results obtained from this study, it was stated that the service quality of KAI employees had an influence on the level of KAI customer satisfaction.
KAI atau dikenal dengan PT Kereta Api Indonesia merupakan penyedia layanan jasa. KAI menyediakan jasa angkutan umum untuk kebutuhan masyarakat. Pada penelitian ini, penulis berfokus kepada tujuan untuk mengetahui apakah kualitas karyawan PT. Kereta Api Indonesia dalam memberikan pelayanan memberikan pengaruh kepada kepuasan pengguna jasa layanan PT. Kereta Api Indonesia baik dalam proses komunikasi verbal maupun komunikasi secara nonverbal. Dalam usaha mencapai tujuan penelitian, pada penelitian ini pendekatan penelitian kualitatif digunakan sebagai metode penelitian yang sesuai dengan pengguna jasa layanan PT Kereta Api Indonesia sebagai populasi dan sebanyak 100 responden berdasarkan hasil rumus Slovin, sebagai jumlah sampel yang dibutuhkan. Regresi linier berganda, uji t, uji f dan uji koefisien determinasi merupakan teknik analisis data yang digunakan pada penelitian ini. Berdasarkan hasil yang didapatkan dari penelitian ini menyatakan bahwa kualitas pelayanan dari karyawan KAI, memberikan pengaruh kepada tingkat kepuasan pelanggan KAI.
Charge regulation triggers condensation of short oligopeptides to polyelectrolytes
Authors: Pineda Sebastian , Staňo Roman , Murmiliuk Anastasiia , Blanco Pablo , Montes Patricia , Tošner Zdeněk , Groborz Ondřej , Pánek Jiří , Hrubý Martin , Štepánek Miroslav , Kosovan Peter
Published: January 2024

Electrostatic interactions between charged macromolecules are ubiquitous in bio- logical systems and they are important also in materials design. Attraction between oppositely charged molecules is often interpreted as if the molecules had a fixed charge, which is not affected by their interaction. Less commonly, charge regulation is invoked to interpret such interactions, i.e., a change of the charge state in response to a change of the local environment. Although some theoretical and simulation studies suggest that charge regulation plays an important role in intermolecular interations, experi- mental evidence supporting such view is very scarce. In the current study, we used a model system, composed of a long polyanion interacting with cationic oligolysines, containing up to 8 lysine residues. We showed using both simulations and experiments that while these lysines are only weakly charged in the absence of the polyanion, they charge up and condense on the polycations if the pH is close to the pKa of the lysine side chains. We show that the lysines coexist in two distinct populations within the same solution: 1. practically non-ionized and free in solution; 2. highly ionized and condensed on the polyanion. Using this model system, we demonstrate under what conditions charge regulation plays a significant role in the interactions of oppositely charged macromolecules and generalize our findings beyond the specific system used here.
Betaketothioesters in Organocatalysis: Harnessing Nucleophilic Reactivity, the Fluorophobic Effect, and Expanding the Substrate Repertoire
Authors: Dajek Maciej , Kubiak Paulina , Bąkowicz Julia , Dziuk Błażej , Kowalczyk Rafał
Published: January 2024

The use of thioesters as nucleophiles marks a considerable change in organic synthesis. This new method, propelled by gentle enolization with minimal catalyst loading, results in enantiomeric excesses surpassing 95% under ambient conditions, accomplishing total conversion in merely 6 hours. Remarkably, this method eliminates the need for additional functional groups in nitroalkenes for efficient chirality transfer from the organocatalyst. The exceptional reactivity of thioesters, combined with their water tolerance, enables reactions utilizing the hydrophobic effect, resulting in reaction times as short as 15 minutes and products with slightly enhanced stereoselectivity compared to analogous reactions in dichloromethane. Additionally, reactions performed in perfluorinated solvents outpace their homogenous counterparts in organic solvents, delivering products in shorter time with comparable stereoselectivity. This work highlights the rare utilization of the fluorous effect in organocatalysis. Simple squaramides also exhibit remarkable catalytic activity in the reactions of beta-keto thioesters with alpha-bromo nitroalkenes. As little as 0.1 mol% of the catalyst leads to product formation with an 86% yield (qNMR) and 93% enantiomeric excess. Upscaling the reaction does not significantly affect the enantiomeric excess but leads to a slight decrease in yield from 82% to 77%. It has been demonstrated that thioesters react more rapidly than their ketoester counterparts, and the two-step reaction leading to dihydrofuran ring closure is entirely accomplished by extending the reaction time, eliminating the need for additional base. The examples presented here expand the range of substrates derived from carboxylic acid esters in catalytic reactions, suggesting the potential for the synthesis of challenging reactions in analogues of alkoxyl esters.
Catalytic Water Electrolysis by Co-Cu-W Mixed Metal Oxides: In-sights from Operando X-ray Absorption Spectroscopy
Authors: Gupta Nikita , Segre Carlo , Streb Carsten , Gao Dandan , Glusac Ksenija
Published: January 2024

Mixed Metal oxides (MMOs) are a promising class of electrocatalysts for the oxygen evolution reaction (OER) and hydrogen evolu-tion reaction (HER). Despite their importance for sustainable energy schemes, our understanding of relevant reaction pathways, catalytically active sites and synergistic effects is rather limited. Here, we applied synchrotron-based X-ray absorption spectrosco-py (XAS) to explore the evolution of an amorphous Co-Cu-W MMO electrocatalyst, shown previously to be an efficient bifunc-tional OER and HER catalyst for water splitting. Ex-situ K- and L-edge XAS measurements provided structural environments and the oxidation state of the metals involved, revealing Co2+ (octahedral), Cu+/2+ (tetrahedral / square-planar) and W6+ (octahedral) cen-ters. Operando XAS investigations, including X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS), elucidated the dynamic structural transformations of Co, Cu, and W metal centers during OER or HER. The ex-perimental results indicate that Co3+ and Cu0 are the active catalytic sites involved in OER and HER, respectively, while Cu2+ and W6+ play crucial roles as structure stabilizers, suggesting strong synergistic interactions within the Co-Cu-W MMO system. These results, combined with the Tafel slope analysis, revealed that the bottleneck intermediate during OER is Co3+ hydroperoxide, whose formation is accompanied by changes in the Cu-O bond lengths, pointing to a possible synergistic effect between Co and Cu ions. Our study reveals important structural effects taking place during MMO-driven OER/HER electrocatalysis and provides es-sential experimental insights into the complex catalytic mechanism of emerging noble metal-free MMO electrocatalysts for full water splitting.
Catalytic Antioxidant Activity of Two Diterpenoid Polyphenols of Rosemary, Carnosol and Isorosmanol, against Lipid Oxidation in the Presence of Cysteine Thiol
Authors: Higashino Hayate , Karatsu Asuka , Masuda Toshiya
Published: January 2024

Lamiaceae herbs such as rosemary have excellent antioxidant properties, and lipidic diterpenoid constituents, such as carnosol, are known as characteristic components to exhibit strong antioxidant activity. This study investigates the effect of thiol compounds on the antioxidant properties of diterpenoid polyphenols. The results concerning the antioxidant activity of polyphenols in the presence of thiol showed that two polyphenols, namely carnosol and isorosmanol, enhanced antioxidant capacity against the radical-induced oxidation of lipids. Further examination of the mechanism revealed that both polyphenols exhibit excellent catalytic antioxidant activity by using the thiol group as a reduction source. Using density functional theory calculations, we attempted to explain why only these two polyphenols exhibit catalytic antioxidant properties. The calculation results and the assumed reaction mechanism suggested that the orthoquinones produced in the antioxidant reactions of carnosol and isorosmanol are more unstable than the others, and that the regioselectivity of their reactions with thiols contributes to their catalytic antioxidant properties.
SmartGraph API: Programmatic Knowledge Mining in Network- Pharmacology Setting
Authors: Zahoránszky-Kőhalmi Gergely , Walker Brandon , Miller Nathan , Yang Brett , Penna Dhatri V. L. , Binder Jessica , Sheils Timothy , Wang Ke , King Jennifer , Sidky Hythem , Vuyyuru Sridhar , Soundarajan Jeyaraman , Michael Samuel G. , Godfrey Alexander G. , Oprea Tudor I.
Published: January 2024

The recent SmartGraph platform facilitates the execution of complex drug-discovery workflows with ease in the network-pharmacology paradigm. However, at the time of its publication, we identified the need for the development of an Application Programming Interface (API) that could promote biomedical data integration and hypothesis generation in an automated manner. This need was magnified at the time of the COVID-19 pandemic. This study addresses this hiatus. Most functionalities of the original platform were implemented in the SmartGraph API. We demonstrate that by using the API it is possible to transform the original semi-automated workflow behind the Neo4COVID19 database to a fully automated one. The availability of the SmartGraph API lends a significant improvement to the programmatic integration of networkpharmacology- oriented knowledge graphs and analytics, as well as predictive functionalities and workflows.
THE ROLE OF cis-MoO2(BHAN)2 COMPLEX IN HALOPEROXIDASE MIMICKING OXIDATIVE BROMINATION
Authors: Deb Priyangana
Published: January 2024

The cis-MoO2(BHAN)2 (BHAN= β-hydroxy-α-naphthaldehyde) has shown promising potential as a biomimetic catalyst for VHPO (vanadium haloperoxidase) activity. In particular, it has demonstrated effective catalytic activity in the bromination of organic substrates such as phenol red producing the corresponding brominated product, bromo phenol blue. This reaction closely mimics bromoperoxidase activity, highlighting the potential of the synthesized complex as a bio-inspired catalyst. Overall, these findings open exciting avenues for development of novel Mo-based VHPO biomimetic catalysts with potential applications in diverse fields like organic synthesis, catalysis and pharmaceuticals.
Semi-continuous temperature cycle-induced deracemization using an axially chiral naphthamide
Authors: Oketani Ryusei , Naito Riku , Hisaki Ichiro
Published: January 2024

This study outlines a practical semi-continuous method for temperature cycle-induced deracemization (TCID) using a batch mode crystallizer. We employed an axially chiral naphthamide derivative as a model compound, and deracemized the crystalline phase by conventional TCID. To achieve a continuity of deracemization, we harvested a part of the suspension after the conventional TCID, then feeding a new racemic suspension into the enriched suspension and applying temperature cycles. By leaving a highly enriched crystalline phase as seed crystals to direct the chirality of the following enrichment, the enrichment process was significantly accelerated, verifying the stable and high production efficiency. Furthermore, from the perspective of process productivity, the moderate suspension density is optimal for efficient deracemization. In the naphthamide system, up to 7.71 g·L−1·h−1 of the productivity was achieved. Thanks to the simple operation, the method described here is applicable for most of batch mode deracemization reported to date. In terms of industrial application, the semi-continuous deracemization could be a good option to utilize the existing batch crystallizers.
SYNTHESIS AND CHARACTERIZATION OF A DIOXOMOLYBDENUM COMPLEX [cis-MoO2(BHAN)2] USING β-HYDROXY-α-NAPHTHALDEHYDE (BHAN) AS LIGAND
Authors: Deb Priyangana
Published: January 2024

This finding demonstrates the synthesis and characterization of a molybdenum-based complex, namely [cis-MoO2(BHAN)2]. The characterization process involved the application of various spectroscopic techniques, including IR, ESI-MS, UV-VIS, and NMR. Additionally, the structural analysis was conducted using Density Functional Theory (DFT), demonstrating excellent concordance with experimental results. The successful synthesis and isolation of cis-MoO2(BHAN)2 in a highly pure form can be confidently concluded based on these findings. This abstract encapsulates the key aspects of the study, emphasizing the comprehensive approach to both synthesis and characterization of the molybdenum complex.
A Simple Regeneration Process Using a CO2-switchable Solvent for Cellulose Hydrogels
Authors: Matsui Arata , Putri Deandra Ayu , Thomas Morgan L. , Takeoka Yuko , Rikukawa Masahiro , Yoshizawa-Fujita Masahiro
Published: January 2024

Cellulose is one of the main components of plant cell walls, abundant on earth, and is a non-edible material that can be acquired at a low cost. Furthermore, there has been increasing interest in its use in environmentally friendly, carbon-neutral, sustainable materials. It is expected that the applications of cellulose will expand with the development of a simple processing method. Previously, it was demonstrated that cellulose can be dissolved in a non-heated, short-duration process using an aqueous pyrrolidinium hydroxide solution. In this study, we dissolved cellulose in aqueous N-butyl-N-methylpyrrolidinium hydroxide solution ([C4mpyr][OH]/H2O) and investigated the cellulose regeneration process based on changes in solubility upon application of CO2 gas. We investigated the effect of transformation of the anion chemical structure on cellulose solubility by flowing CO2 gas into [C4mpyr][OH]/H2O and conducted pH, FT-IR, and 13C NMR measurements. We observed that the changes in anion structure allowed for the modulation of cellulose solubility in [C4mpyr][OH]/H2O, thus establishing a simple and safe cellulose regeneration process. This regeneration process was also applied to enable the production of cellulose hydrogels. The hydrogel formed using this approach was revealed to be of a higher mechanical strength than that of an analogous hydrogel produced using the same dissolution solvent with addition of a cross-linker. The ability to produce cellulose-based hydrogels of different mechanical properties is expected to expand the possible applications.
Making 1H-1H couplings more accessible and accurate with selective 2DJ NMR experiments aided by 13C satellites
Authors: Cantrelle François-Xavier , Boll Emmanuelle , Sinnaeve Davy
Published: January 2024

1H-1H coupling constants are one of the primary sources of information for NMR structural analysis. Several selective 2DJ experiments have been proposed that allow their individual measurement at pure shift resolution. However, all these experiments fail in the not uncommon case when coupled protons have very close chemical shifts. Firstly, the coupling between protons with overlapping multiplets is inaccessible due to the inability of a frequency-selective pulse to invert just one of them. Secondly, the strong coupling condition affects the accuracy of coupling measurements involving third spins. These shortcomings impose a limit on the effectiveness of state-of-the-art experiments, such as G-SERF or PSYCHEDELIC. Here, we introduce two new and complementary selective 2DJ experiments that we coin SERFBIRD and SATASERF. These experiments overcome the aforementioned issues by utilizing the 13C satellite signals at natural isotope abundance, which resolve the chemical shift degeneracy. We demonstrate the utility of these experiments on the tetrasaccharide stachyose and the challenging case of norcamphor, for the latter achieving measurement of all JHH couplings while only few were accessible with PSYCHEDELIC. The new experiments are applicable to any organic compound and will prove valuable for configurational and conformational analyses.
Unveiling the Anti-Radical Potential of Galangin — A Detailed Density Functional Theory Investigation
Authors: Spiegel Maciej
Published: January 2024

A comprehensive quantum mechanical investigation into the antiradical activity of galangin (Glg), a natural flavonoid recognized for its robust antioxidant and anti-inflammatory properties, is presented. The compound undergoes successive deprotonation at C7 (pKa=7.48), C3 (pKa=9.34), and C5 (pKa=12.07). At pH 7.4, the predominant species are the neutral form (54.37%) and the first deprotonation product (45.11%), with the dianion present at a minor level (0.51%). According to eH-DAMA results, Glg exhibits improved antiradical effectiveness in water compared to apolar solvents. In both solvents, exergonic pathways towards •OOH radicals involve radical adduct formation at C2, while the highest propensity for HAT is associated with the C3 hydroxyl. Electron transfer pathways are not preferred, as indicated by Marcus’s parabola. The overall reaction rate was established at 3.77 × 103 M-1 s-1 in pentyl ethanoate and 1.69 × 105 M-1 s-1 in water, considering the molar fractions of individual species and hy-droperoxyl radicals at pH=7.4. The magnitude of the same reaction rate within the physiological pH range (pH=1.5 – 8.5) is consistently not less than 3.5, gradually reaching a peak value of 5.48 starting from pH=5. Furthermore, all Glg species readily undergo regeneration mediated by O2•-.
Cu(II)-Assisted Novel Covalent Warheads for Proteome-wide Cysteine Profiling
Authors: Fu Songsen , Yao Yingrui , Chen Jiaqi , Mao Xiaoran , Hong Bang , Ni Feng
Published: January 2024

In the realm of residue-specific labeling of amino acids within the proteome, cysteine (-SH) emerges as a particularly nucleophilic residue and plays a pivotal role in covalent drug discovery. Despite significant strides in targeting cysteine sites, there remains a substantial expanse of unexplored site space. We discovered that a nucleophilic phenol (DBA)/Cu2+ ‘complex’ serves as a potent warhead for traditionally "inert" cysteines. In the context of a general chemoproteomics profiling, the DBA-1 probe exhibits higher reactivity than IAA toward approximately 45% of quantifiable Cys sites. Dose-dependent profiling experiments suggest that Cu2+ may function not only as an oxidizing agent of phenol but also as a chelating agent of polar residues in proteins. Given its reliance on structural characteristics of proteins for site targeting, this novel (DBA)/Cu2+ ‘complex’ fits the scope of ‘structure-based protein profiling’ (SBPP), highlighting the role of metal ion in the design of effective warheads and the virtue of new proteomic microenvironmental chemistry ‘hunting’.
Structural isomerism-tuned magnetisation relaxation dynamics in lanthanide coordination complexes
Authors: Hansen Steen Hansgaard , Buch Christian Dirk , Piligkos Stergios
Published: January 2024

The eigenspectrum and eigenvectors of the 2F7/2 ground multiplets of two structural isomer coordination complexes, Yb(trenovan) (H3trenovan = tris(((3-methoxysaliclidene)amino)ethyl)amine) and Yb(trenpvan) (H3trenpvan = tris(((5-methoxysaliclidene)amino)ethyl)amine), were determined by use of magnetometry and electron paramagnetic resonance and luminescence spectroscopies. The two 4f complexes crystallise in the trigonal 𝑃3̅ space group, have identical chemical formulas and differ only in the placement of the methoxy group on the aromatic ring of salicylaldehyde, with it being either ortho, Yb(trenovan), or para, Yb(trenpvan), to the phenoxo group. This structural isomerism is found to have a profound influence on the solid state static and dynamic magnetic properties of the complexes. In the bulk, both isomers display a combination of direct and raman magnetisation relaxation procceses, however, at vastly different rates. Magnetic dilution in an isostructural diamagnetic host supresses the occurrence of the direct procces suggesting that the direct process observed in the bulk originates from Yb(III) centres coupled by magnetic dipole interactions. The eigenspectrum, eigenvectors and spin lattice relaxation of Yb(trenpvan) are found to be closer to the ones found in Yb(trensal) (H3trensal = tris(((saliclidene)amino)ethyl)amine) where the methoxy group is substituted by an H atom, than to those of Yb(trenovan) where the methoxy group is in the ortho position. Thus, the position of chemical modifications has a tremendous influence on the static and dynamic solid state magnetic properties of 4f coordination complexes. Our detailed study on single crystals, demonstrates that the rarely studied effect of modifications of the position of second coordination sphere chemical groups on the dynamic magnetic properties can in fact be used to chemically tune the magnetisation dynamics of 4f spin systems.