bluuebunny/crossref_metadata_2025_split huggingface dataset:
Voluntourism as an Effort to Realize Sustainable Tourism to Reduce Waste in the Ocean
Authors: Janitra Nabila Thyra , Muis Afni Regita Cahyani 
Published: June 2023

In response to the problem of increasing waste in the ocean, UNWTO formulated sustainable tourism to create economic, social, and environmental stability. In the effort to realize sustainable tourism, UNWTO introduces a voluntourism program that directly seek to attract tourists' interest and make tourists become aware of the importance of protecting the environment. This study aims to understand the voluntourism strategy to realize sustainable tourism to reduce waste in the ocean. The method used in this study is a qualitative-explorative method that intends to explore social phenomenon based on the variables that have been formulated. In responding to the issue of marine pollution caused by garbage, voluntourism makes various efforts to cooperate with several stakeholders. The voluntourism program that focuses on the topic of marine pollution is expected to become a policy recommendation to be implemented by various countries, hence efforts to reduce waste in the sea can be massively carried out in different parts of the world. This study discusses the distribution of waste in the oceans and efforts to handle it through voluntourism programs.
Keywords: Ocean Waste, Sustainable Tourism, Voluntourism

Dalam merespon permasalahan peningkatan sampah di lautan, UNWTO memformulasikan pariwisata berkelanjutan untuk menciptakan kestabilan ekonomi, sosial dan lingkungan. Dalam mewujudkan pariwisata yang berkelanjutan, UNWTO memperkenalkan program volunterisme yang secara langsung menarik minat wisatawan dan membuat wisatawan semakin menyadari akan pentingnya menjaga lingkungan. Penelitian ini bertujuan untuk memahami strategi volunterisme untuk mewujudkan pariwisata berkelanjutan guna mengurangi sampah di lautan. Metode yang digunakan dalam penelitian ini adalah metode kualitatif-eksploratif yang menggali fenomena sosial berdasarkan variabel yang telah dirumuskan. Merespon isu polusi laut yang disebabkan oleh sampah, volunterisme menciptakan berbagai upaya untuk bekerja sama dengan para pemangku kepentingan. Program volunterisme yang berfokus pada topik polusi kelautan diharapkan mampu menjadi rekomendasi kebijakan yang dapat diimplementasikan oleh berbagai negara, sehingga upaya pengurangan sampah di lautan dapat secara masif dilakukan di berbagai bagian dunia yang berbeda. Studi ini mendiskusikan tentang penyebaran sampah di lautan dan upaya untuk menanganinya melalui program volunterisme.
Kata-Kata Kunci: Limbah Lautan, Pariwisata Berkelanjutan, Volunterisme
Traumatic Hallux Metatarsophalangeal Joint Medial Collateral Ligament Avulsion in a Professional Surfer: Suture Anchor Repair and Suture Tape Augmentation
Authors: Epstein Caroline , Montero Daniel , Haupt Edward 
Published: June 2023

Case:
Acute medial collateral ligament (MCL) tears of the great toe metatarsophalangeal joint are rare, leading to sparse literature regarding their management. Suture anchor repair with suture tape augmentation is an effective treatment of thumb ulnar collateral ligament tears, a close analog. This case report presents a 23-year-old professional surfer with an acute hallux MCL avulsion. Management included repair with suture anchor and suture tape augmentation. The patient returned to sport quickly and had no pain or complications at 1-year follow-up.

Conclusion:
In this case of acute MCL tear of the great toe, suture anchor repair with suture tape augmentation facilitated early mobilization, rapid rehabilitation, return to competitive sport, and sustained good outcome.

Level of Evidence:
Level V
Synthetic Fractional Flow Curves Based on Continuous Well Logs Honoring Highly Heterogeneous Properties in Heavy Oil Reservoirs
Authors: Angle Sáez Franklyn Javier , Galán Toloza José Antonio 
Published: June 2023

Abstract
Perforation intervals selection is an issue in heavy oil reservoirs since low water saturation is not directly related to low water cuts in production, thus, making it necessary to use fractional flow (fw) curves; nevertheless, for highly heterogeneous reservoirs it is useless to average an fw curve by stratigraphic or hydraulic flow units. In this paper we present continuous vertically variable fw curves, each half feet (logs resolution), as a novel approach to honor heterogeneity.
Heterogeneity in the tertiary rocks of Llanos Basin, Colombia, is exhibited by dramatic changes in properties, mainly driven by diagenesis rather than mineralogy; and even when rock types were defined via FZI, there is a wide range of potential clay volume-effective porosity-permeability (VCL-PHIE-K) combinations within a single rock type. Following a series of multiple regressions, we could get unique values of fw, every half feet, for any VCL-PHIE-K combination at a given water saturation (Sw) and then, by simply averaging the fw values over the perforating intervals, it was possible to predict the expected water cut (BSW) during the first production stages. Then, a comparison of fw with BSW, in some random wells, yielded an average estimation difference of ±9 percent points, which validates the methodology and offers a much more reliable alternative to SW curves when predicting oil production. Among other results, since strong aquifers and an active water injection process influence these fields, the estimation of a water saturation before water breakthrough (Sw_BT) curve helped us understand how the highest permeability sands (RT1) were irrupted by high BSW slower compared to lower permeability sands (RT3). Consequently, the Sw cutoff (Sw_CUTOFF), estimated for a maximum fractional flow (fw_MAX) of 95%, showed averaged values between 32% and 45%, depending on rock types (RTs).
We conclusively found that this methodology can help avoid undesirable high BSW, since we can first diagnose if the water is about to irrupt by using an Sw_BT curve, then we can dodge water saturated intervals above a variable Sw_CUTOFF (instead of using a constant 50% cutoff), and finally we can predict, with more than a 90% of accuracy, the BSW to manage at surface by using fw curves, rather than simple Sw curves.
Electro-Acoustic Solvent-Based Method for Enhancing Heavy Oil Recovery
Authors: Khasi Saeid , Kantzas Apostolos 
Published: June 2023

Abstract
A novel multi-physics approach is proposed to enhance performance of solvent extraction methods in heavy oil reservoirs by utilizing the enhanced mixing and spreading during acoustic excitation. In the modeling, the macroscopic flow equation is coupled to the conservative form of the advection-dispersion model while it is linked with an external time harmonic body load in a poroelastic domain. Linking the latter elements of the modeling is fully coupled and both impacts of the pressure load on the rock stress as well as the induced pore pressure by the rock strain are considered. Numerical simulation results are obtained by solving coupled macroscopic equations using the finite element method for a quarter five-spot source-sink geometry. Based on the numerical solutions, normalized concentration profiles of the displacing fluid as well as plots of resident and effluent concentrations are obtained for qualitative and quantitative analyses. Simulation results of the recovery enhancements are compared to conventional solvent-based methods of enhanced heavy oil recovery in terms of energy trade-off. Acoustically assisted solvent flooding reduces the required volume of injected solvent through enhancing dispersive mixing. The acoustic excitation at a relative amplitude of 200, which is applicable to field scale applications, can result in an additional 12 % enhancement in displacing an in-place fluid via an assisted solvent extraction process as compared to the equivalent silent displacement. Such enhancement happens both before and after breakthrough. Higher amplitudes and frequencies and wave propagations transverse to the flow direction increase the enhancement. Combining acoustic stimulations and electromagnetic (EM) heating may further enhance the recovery. The required equations to incorporate EM heating are provided as well. In the proposed multi-physics approach, both the required amounts of solvent and the greenhouse gas (GHG) emissions can be reduced. Electricity usage by the elements of excitations will be the key contributors in reducing GHG emissions’ footprints of heavy oil extraction. The simulation results of the developed model can provide an estimation of input parameters in economic analysis such as the cumulative delivered energy to oil ratio that is an essential component in calculating GHG emissions.
Reducing Environmental Footprint of Borehole Seismic Acquisition by Using DAS on Hybrid Logging Cable
Authors: Duque Helman , Briceño Alexander López , Perez Alexander Duarte , Villasmil Jose , Useche Manuel , Martinez Alejandro , Ruge Susy Mercado , Ordoñez Andrea , Sanchez Diego , Marin Dilan 
Published: June 2023

Summary
Borehole seismic data from vertical seismic profiles (VSP) provide valuable information in different stages of reservoir evaluation. Land VSPs are generally acquired using a wireline-specific run involving a logging unit, a downhole geophone-based tool, and vibrator truck operating 10 hours to 1 day for typical zero-offset VSP surveys (ZOVSP). Nowadays, novel technologies, such as fiber optic cable, allow geoscientists to get VSP measurements while reducing logging times to minutes and reducing the environmental footprint of the operation.
Distributed acoustic sensing (DAS) and electric hybrid logging cable allow borehole seismic information to be efficiently obtained over the entire well in a fraction of the time required by conventional methods. The land ZOVSP surveys discussed in this work were acquired while conveying various logging tools with a hybrid optical heptacable by Ecopetrol S.A. in Colombia onshore. In many of these jobs, data acquisition is carried out in areas close to communities, houses, or infrastructure that may be impacted by closing roads or by vibrations emitted by the seismic source. Also, high levels of noise for long periods could distress nearby inhabitants.
The reduction of carbon footprint is a direct benefit when using this technology. Less operating time can reduce CO2 emissions over 90% in a VSP acquisition. ZOVSPs with conventional geophone technology were estimated to take in average 17 hours in wells with the profiles considered here. In contrast, with DAS on hybrid logging cable, this operation takes 1.5 hours, which immediately translates into a lower carbon emission footprint equating to an estimated 95% CO2 reduction per job.
Another Look at Bovallius, Onshore Southern Basin Trinidad
Authors: Bishop M. , Moonan X. , Lalla W. , Anderson L. 
Published: June 2023

Abstract
The Bovallius field, located in the southeastern part of Trinidad is bordered to the west by the Balata East block and to the south by the Ortoire block. The field spans approximately 942 acres with six wells drilled in the block to date, the first well being drilled in 1954. Regionally the Bovallius field occurs on trend with a WSW plunging, SE verging thrusted anticlinal system. The major tectonic features within the Bovallius field consists of the eastern extension of the Balata anticline which is truncated by several NE-SW trending thrust faults, several NW-SE trending normal faults and bordered to the east by the NE-S/SW Cedar Grove fault. Previous evaluations done on the Bovallius field resulted in little prospectivity for the block. Recent discovery wells within the Ortoire Block, created renewed interest over the Bovallius field. It is known from analogous fields that there are three structural limbs which occur in the Herrera formation: Overthrust, Intermediate and Sub-thrust. Field wide mapping indicated that most of the wells within the Bovallius field penetrated three thrust sheets within the Overthrust limb only. As such the undrilled Intermediate and Sub-thrust limbs present an exploration opportunity within the field. Sand maps constructed on the producing reservoirs show that these sands trend in a NE-SW direction with the thickest accumulations occurring sub-parallel to the axis of the anticline. Similarly, as seen in the Penal/Barrackpore and Cascadura fields, within the Bovallius field the anticlinal system plunges to the SW with NW-SE trending normal faults dissecting the anticlinal feature. The most prospective areas tend to be in the eastern crestal structurally up-dip parts of these fault blocks. This updated model resulted in three outstep prospects. Field development in the southern part of the Bovallius block was heavily influenced by Balata East wells, BE-6, and BE-19. These wells are located on the southern flank of the Balata anticline and encountered the Herrera sands wet. At the time it was believed that as the majority of the Bovallius block lies downdip of these wet wells, the Herrera sands would also be wet over this acreage. However, on examination of some of the surrounding wells in the area, this assumption has been relooked. There is a thrust fault running in a NE-SW direction, south of the wet Balata wells which allow for hydrocarbon accumulation within the OL-4/Royston area. This makes the southern part of the Bovallius block prospective for the Herrera sands.
Comparison of Riser Gas Unloading in Water and SBM: Full-Scale Experiments
Authors: Kunju Mahendra R , Almeida Mauricio 
Published: June 2023

Abstract
The potential for a gas-in-riser situation to become uncontrollable by the rapid displacement of mud out of the riser is extremely high if the riser-top is left open. The unloading can be catastrophic in synthetic-based mud (SBM) or oil-based mud (OBM) when the gas remains dissolved and undetected till pressure reduction causes sudden desorption of dissolved gas closer to the surface. This work demonstrates, investigates, and provides insights into the riser gas unloading phenomena with the help of full-scale gas migration experiments.
A 5200 ft deep vertical test well (9 5/8" x 2 7/8" casing/drill-pipe) at LSU instrumented with 4 down-hole PT gauges was used for the tests. Tests were carried out in water, and SBM. Each test started by injecting a fixed volume of nitrogen gas (5 to 15 bbl) at a low (0.3 bbl/min) or high flow rate (4 bbl/min) from the bottom of the annulus while keeping the annulus open. After the influx, the annulus was either closed at the surface to study the effects of gas migration under shut-in conditions or left open to study the effects of gas migration under open-top annulus conditions.
The rate of pit-gain reduced during the low-void-fraction gas tests in water, and SBM-filled-annulus when gas influx stopped (closing of subsea BOP). However, for the high-void-fraction test in SBM, the pit-gain stopped once influx stopped and remained negative from 6.5 minutes to 35.5 minutes due to a reduction in mud level caused by the dissolution of gas in SBM. The pit gain later resumed and continued to increase. Keeping the annulus open resulted in a rapid exponential increase in pit-gain as the gas-front neared the surface requiring an immediate shut-in of the annulus to avoid unsafe rapid discharge. The final estimated outflow rate based on cumulative pit-gain (Coriolis) was 160gpm for the high-void-fraction test in SBM. Pressure, and differential pressure data from pairs of gauges were used to make real-time decisions during the tests and to estimate the location and migration velocities of gas-front and tail. The model developed for analysis and comparison of test results in water is used here to explain the behavior of gas migration under open-top conditions.
A thorough investigation with the help of gauge data and pit gain has explicated our understanding of gas migration behavior and its effect on the dynamics of gas-liquid equilibrium from influx to impending unloading situation. The interesting results from the tests are extremely useful in explaining the dangers of using open-top annulus on rigs.
Association between body mass index and age of disease onset with clinical outcomes in paediatric Crohn's Disease (CD): a UK nation-wide analyses using the NIHR-IBD Bioresource
Authors: Aljilani Bayan , Tsintzas Kostas , Siervo Mario , Moran Gordon W 
Published: June 2023

Abstract
Background:
The relationship between adiposity and disease outcomes has never been investigated in paediatric Crohn’s disease (CD).
Aim:
To investigate the relationship between a) body mass index (BMI) and clinical disease outcomes (hospitalisation, surgery, disease behaviour, biologic use and comorbidities) and b) the association between age of disease onset with clinical outcomes.
Design:
Outcomes were examined retrospectively in CD patients diagnosed at age <17 years. Data was obtained from the National Institute for Health Research IBD-UK BioResource. Subjects were categorised into normal BMI (<25kg/m2) and high BMI (≥25 kg/m2). Age at disease diagnosis was categorised into pre-puberty/early puberty (<11 years), puberty (11-14 years) and post-puberty (15-17 years). Spearman rank correlation was used to test the associations between continuous variables and chi-square test was used to compare categorical variables.
Results:
848 participants with CD were included, 51.8% males and a median age at diagnosis was 14 years. The median BMI measured at consent was 22.6 kg/m2. Most of the participants (N= 605) had a BMI<25 kg/m2 with 243 (28%) participants having a BMI³25 kg/m2. Those with high BMI were linked to a greater frequency of comorbidities (1 type of comorbidities: BMI³25= 20.6%; P=0.05 and ≥2 types of comorbidities: BMI³25= 8.6%; P=0.05, respectively). BMI and age at diagnosis showed a correlation with corticosteroid use (ρ=-0.09, P=0.01 and ρ=0.08, P=0.03, respectively). An early diagnosis (<11 years) was associated with complicated disease behaviour (p=0.01) and hospitalisation (P<0.001).
Conclusions:
A higher BMI and an earlier age of disease are associated with worse CD outcomes.
Freedom From Infection (FFI): A paradigm shift towards evidence-based decision-making for malaria elimination.
Authors: Nelli Luca , Surendra Henry , Byrne Isabel , Ahmad Riris , Arisanti Risalia , Lesmanawati Dyah , Elyazar Iqbal , Dumont Elin , Drakeley Chris , Wu Lindsey , Matthiopoulos Jason , Stresman Gillian 
Published: June 2023

Abstract

Background: Assessing elimination of malaria locally requires a surveillance system with high sensitivity and specificity to detect its presence without ambiguity. Currently, the absence of locally acquired cases for three consecutive years is used as confirmation of elimination. However, relying on routine health data to prove the absence of infection presents challenges, as even one missed case can lead to incorrect inferences and potential resurgence. Overcoming this challenge requires innovative approaches to model the coupled processes of malaria transmission and its clinical observation.
Methods: We propose a novel statistical framework based on a state-space model to probabilistically demonstrate the absence of malaria, using routinely collected health system data (which is extensive but inherently imperfect). By simultaneously modelling the transmission dynamics within the population and the probability of detection, our approach was designed to provide a robust estimate of the surveillance system's sensitivity and the corresponding probability of local elimination (PFree).
Findings: Our study reveals a critical limitation of the traditional criterion for declaring malaria freedom, highlighting its inherent bias and potential for misinterpreting ongoing transmission. Importantly, our research demonstrates the high sensitivity of this approach to observation biases, where even a single missed infection can lead to erroneous conclusions. We show that the traditional criterion can fail to identify ongoing transmission, even in the absence of reported cases.
Interpretation: Our approach represents a significant advancement in programmatic decision-making and malaria interventions. This methodological advancement has far-reaching implications, not only for malaria control but also for infectious disease control in general. By enhancing surveillance systems and optimizing resource allocation, our approach creates opportunities to address the limitations of traditional criteria for declaring disease freedom. Our findings emphasize the urgent need to reassess existing methods to accurately confirm malaria elimination, and the importance of incorporating comprehensive modelling techniques to improve the design and implementation of surveillance systems, ultimately leading to more effective strategies for infectious disease control. The scalability and feasibility of our integrative modelling approach further support its potential to revolutionize surveillance systems and enhance public health outcomes.
Funding: Bill and Melinda Gates Foundation, Indonesia Endowment Fund for Education.
Investigation of Work Coordinate System Setting in Ultra-Precision Machining Using Electrical Breakdown for Non-Conductive Materials
Authors: Lowery Zach , Maeng Sangjin , Min Sangkee 
Published: June 2023

Abstract
The ultra-precision machine tool industry has been consistently improving to the point where machine tools with extreme thermal controls, vibration damping, and command resolutions of 0.1 nm are commercially available. As little research focus has been given to developing peripheral technologies, currently available work coordinate system setting methods are a bottleneck on the achievable accuracy of ultra-precision machine tools. One of the work coordinate system setting methods uses electrical breakdown. The electrical phenomenon occurs when a sufficiently large voltage difference is applied between two conductors. This phenomenon has been observed to have a linear relationship between the breakdown voltage and gap length at short gap lengths. Electrical breakdown is a capable work coordinate system setting with an accuracy of 100s nm. However, this method is limited to electrically conductive cutting tools and workpiece materials. This study proposes a work coordinate system setting method for ultra-precision machining based on electrical breakdown for non-conductive materials. In this study, a conductive thin film coating is applied to polycrystalline diamond cutting tools to facilitate electrical breakdown work coordinate system setting. With similar motivation, a modification method was tested to enable electrical breakdown work coordinate system setting on non-conductive workpiece materials. The modification method used a 50 nm thick platinum coating on the workpiece. This study also introduces a method for automatic work coordinate system setting using electrical breakdown and sensors built into the machine tool.