Single Trip Research Articles

Small-scale LNG Carriers Revolutionize Power Plant Supply in Eastern Indonesia

As a consequence of the global greenhouse gas problem, various adjustments are required, particularly in the energy sector. The government program envisages the development and conversion of power plant fuels to LNG to ensure energy distribution throughout the region, especially in Indonesia's remote islands. One of the biggest challenges in distributing energy to remote locations is the logistical difficulties in reaching these areas. Utilization-scale LNG carriers as a mode of transportation offers a potential solution to this problem. This study aims to optimize the distribution of LNG using small-scale LNG carrier transportation mode to meet the needs of power plants. The application of the Capacitated Vehicle Routing Problem method to a single vessel with different speed variations is used to optimize the distribution of LNG aiming to maximize its cargo capacity. The results of this study show that using a vessel with identical specifications as in Eastern Indonesia, operating at a specific speed, optimizes cargo capacity for a single round trip. These results will serve as a basis for future studies and facilitate the further development of existing methods.

High dynamic range vector soliton mode-locking via nonlinear Sagnac gating

Ultrafast fiber lasers enable vector soliton generation with richer dynamics than scalar solitons, offering enhanced flexibility for high-capacity communications and optical storage. However, generating vector solitons in short resonators without any physical saturable absorbers remains challenging, consequently limiting their dynamic ranges, energy scales, and repetition rates. Here, we propose a nonlinear Sagnac gating method in a hybrid mode-locked fiber laser to facilitate intracavity vector soliton generation, combining nonlinear amplifying loop mirror and nonlinear polarization rotation (NPR) mechanisms. This method significantly enhances the vectorial characteristics of solitons within a single short round trip, enabling high-repetition-rate operation even with the intracavity polarizer necessary for NPR. In turn, pulse shaping and phase bias introduced by NPR effectively improve system stability and reduce the self-starting mode-locking threshold. The expanded parameter space and dynamic range enable flexible switching between various vector soliton states. Moreover, the polarization states on the generated vector solitons no longer change pulse by pulse, ready for scientific and industrial applications. Our research results offer valuable insights into the formation and evolution of vector solitons. The developed laser also provides an excellent multifunctional platform for simulating complex nonlinear systems and investigating the corresponding soliton dynamics.

Determination of Tourist Bus Fares in Batu City Based on Ability to Pay, Willingness to Pay, and Vehicle Operating Cost

Batu City often experiences traffic congestion. This congestion is caused by the road network in Batu City needing to be proportional to the number of vehicles present. Therefore, breakthroughs (innovations) are required to reduce traffic jams and make it easier for tourists visiting Batu City to reach tourist areas. However, attention must be given to several important factors, including the community's preference for using the Batu City Tourist Bus and the Willingness to Pay (WTP), Ability to Pay (ATP), and Vehicle Operating Costs (BOK) to determine a fare that aligns with these aspects. The method used is a quantitative approach with frequency distribution analysis techniques, Willingness to Pay (WTP) analysis, Ability to Pay (ATP) analysis, and Vehicle Operating Costs (BOK) analysis. The study results show that 71% of tourists are interested in using the tourist bus, mainly because of the ease and comfort of travel, cost efficiency, tourism development, and flexibility. The tourist bus fare based on ATP is IDR 64,397, and the fare of the two routes based on WTP is IDR 24,219 and IDR 24,730. Then, on the BOK calculation, the fare is IDR 54,972 and IDR 45,450. Therefore, the determined fare for the Batu City Tourist Bus for a single round trip is IDR 30,000, with a government subsidy for the tourist bus's BOK amounting to IDR 329,520,297 per year. This study's results are expected to serve as a consideration for the Batu City Government in determining the fare for the Batu City Tourist Bus.

Research and Application of Geomechanics Using 3D Model of Deep Shale Gas in Luzhou Block, Sichuan Basin, Southwest China

The deep shale gas resources of the Sichuan Basin are abundant and constitute an important component of China’s natural gas production. Complicated by fault zones and other geostructures, the in situ stress state of the deep shale gas reservoirs in the Luzhou block remains poorly understood. This study integrated multiple datasets, including acoustic logging, diagnostic fracture injection testing (DFIT), imaging logging, and laboratory stress measurements, for calibration and constraint. A high-precision geomechanical model of the Luzhou block was constructed using the finite element method. This model characterizes the geomechanical properties of the reservoir and explores its applications in optimizing shale gas horizontal well placement, drilling processes, and fracture design. The study findings indicate that the Longmaxi Formation reservoir demonstrates abnormally high pore pressure, with gradients ranging from 16.7 to 21.7 kPa/m. The predominant stress regime is strike-slip, with an overburden stress gradient of 25.5 kPa/m and a minimum horizontal principal stress gradient ranging from 18.8 to 24.5 kPa/m. Based on a three-dimensional geomechanical model, a quantitative delineation of areas conducive to density reduction and pressure control drilling was conducted, and field experiments were implemented in well Y65-X. Utilizing an optimized drilling fluid density of 1.85 g/cm3, the deviated horizontal section was completed in a single trip, resulting in a 67% reduction in the drilling cycle compared to adjacent wells. Similarly, the Y2-X well demonstrated a test daily output of 506,900 cubic meters following an optimization of segmentation clustering and fracturing parameters. Studies indicate that 3D geomechanical modeling, informed by multi-source data constraints, can markedly enhance model precision, and such geomechanical models and their results can effectively augment drilling operational efficiency, elevate single-well production, and are advantageous for development.

Mending a World of Problems: 12-Year Review of Medical Tourism Inbound Complications in a Tertiary Centre.

Medical tourism is a rapidly expanding multi-billion-dollar industry. Reduced costs, all-inclusive vacation packages that include cosmetic surgery, globalization, and affordable flight expenses have encouraged patients to seek aesthetic procedures in different countries. Cosmetic medical tourism is associated with high complication rates, such as severe infections, wound dehiscence, pain or discomfort, aesthetic dissatisfaction, and even death. A twelve-year survey of medical records was conducted using ADAMS healthcare database software. Data regarding patient demographics, the country of the original procedure, the operation type, complications, and subsequent treatment were recorded. Fifty-six patients have been admitted to the Department of Plastic and Reconstructive Surgery. The youngest patient was 18, and the oldest was 65, with an average age of 37.46. The majority were females (n = 51, 91.07%). The most common procedure was liposuction (n = 40), followed by abdominoplasty (38). Only eleven patients had a single procedure while travelling; on average, they had 2.34 procedures in a single trip. Patients presented with an average POD of 30.9. The most common complaint was dehiscence at the surgical site. Eleven patients required re-operation. The average hospitalization length in the Plastic and Reconstructive Surgery Department was 4.4 days. Medical tourism has a positive impact on patients and caregivers alike. However, the combination of multiple procedures in a short time, relatively short follow-up, different microbial environments, and more led to substantial complications, which had a devastating effect on many patients. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

The shared autonomous vehicle’s scheduling and routing problem when providing the trip-chain based service for users

Shared autonomous vehicle (SAV) is expected to become an essential transportation mode. However, the studies on its scheduling and routing problems are all based on peer-to-peer (P2P) service, which refers to a pickup and delivery on a single trip. The P2P service ignores the correlations between sub-trips and users' journey continuity. To address this problem, a trip-chain based (TCB) service is proposed in SAV system, where users can choose paying and keep SAVs (PKSS) with no waiting time. Furthermore, based on the network flow theory, an integer linear programming model was established to decide optimal SAV's routing and scheduling. Finally, experiments are conducted in Beijing, China. Compared with the P2P service, the TCB service can not only increases operators' profitability but also reduces users' waiting time, provided that the operators set the price for PKSS between 0.1 and 0.65 CNY per minute.

Praktik Rantai Pasok Berkelanjutan: Penerapan Milk Run di Industri Plastik

This study aims to explore the impact of implementing the Milk Run method in supply chain of plastic industry in PT RPI. By reducing the distance of 48 km per day, equivalent to 1,200 km in a month of deliveries, the research highlights significant changes in logistics’ efficiency, cost savings, and carbon emission reduction. More connected travel patterns allow trucks to combine pick-ups or deliveries of multiple sources in single trip to enhance the overall logistics’ efficiency. Reducing the distance contributes to saving transportation’s cost by lowering fuel consumption and maintaining vehicle expenses. Reducing a 1,200 km distance, assumed that a fuel consumption rate of 7 km per liter and a carbon emission rate of 2.68 kg CO2 per liter, could result in a substantial carbon emission reduction. This study provides a foundation for further research, including route and scheduling optimization, in-depth environmental impact analysis, and Milk Run implementation in other industries. The findings offer a comprehensive overview of Milk Run effectiveness in the plastic industry, emphasize operational advantages, economic impact, and commitment to sustainability.

Encouraging shared and pooled-use automated vehicle mode choice—what users are sensitive to what instruments?

In recent years, the body of literature on automated vehicles (AV) regarding simulation, user acceptance, and accompanying research on pilot projects has increased substantially. However, studies investigating the relationship between user characteristics and preference of shared or pooled-use AV, such as automated taxis or automated shuttles, mainly investigate socioeconomic or mobility characteristics of potential users. Further, there are no studies on user-type sensitivity toward instruments fostering the uptake of shared and pooled-use AV. The aim of our study is to contribute to fill this gap, to provide important knowledge for decision-makers to develop transport policies designed to foster future sharing of AV. To this end, we re-analyze data from a choice experiment with 709 participants together with individual user characteristics, collected within the Swiss Household Energy Demand Survey. Specifically, we analyze the role of socioeconomic and mobility characteristics, attitudes and values regarding sensitivity toward policy-relevant push and pull instruments to foster shared and pooled-use AV mode choice. We show that different types of user characteristics have an impact on AV mode preference and on the sensitivity toward the categories and types of instruments tested. Furthermore, we show that it is worthwhile to differentiate between short-term mobility decisions on single trips and long-term mobility decisions, concerning purchase decisions for AV or subscriptions to AV-related mobility services.

A real-time energy and cost efficient vehicle route assignment neural recommender system

A real-time energy and cost efficient vehicle route assignment neural recommender system

Linear-coupling-induced double-period pulsating vector solitons in lasers.

Pulsating solitons is a universal phenomenon originating from the Hopf-type bifurcation in dissipative systems such as lasers and microresonators. Here, we report the vector soliton in a fiber laser pulsating with two periods of different orders of magnitude. The short-period pulsation manifests as the period-tripling facilitated by the linear coupling between orthogonal polarization components, which breaks the self-consistent evolution of the vector soliton over a single round trip (RT). The long-period pulsation arises from the mode competition between the two polarization components mediated by various cavity effects. The interplay between linear coupling and mode competition gives rise to the robust double-period pulsating (DPP) vector soliton. Our results provide a clear physical mechanism for the broadly observed double-period breather, which has a significant value in exploring breathers with complex dynamics and multiple comb spectroscopy.

A novel technique for estimating age and demography of long-lived seabirds (genus Pterodroma) using an epigenetic clock for Gould's petrel (Pterodroma leucoptera).

Understanding the demography of wildlife populations is a key component for ecological research, and where necessary, supporting the conservation and management of long-lived animals. However, many animals lack phenological changes with which to determine individual age; therefore, gathering this fundamental information presents difficulties. More so for species that are rare, highly mobile, migratory and those that reside in inaccessible habitats. Until recently, the primary method to measure demography is through labour intensive mark-recapture approaches, necessitating decades of effort for long-lived species. Gadfly petrels (genus: Pterodroma) are one such taxa that are overrepresented with threatened and declining species, and for which numerous aspects of their ecology present challenges for research, monitoring and recovery efforts. To overcome some of these challenges, we developed the first DNA methylation (DNAm) demography technique to estimate the age of petrels, using the epigenetic clock of Gould's petrels (Pterodroma leucoptera). We collected reference blood samples from known-aged Gould's petrels at a long-term monitored population on Cabbage Tree Island, Australia. Epigenetic ages were successfully estimated for 121 individuals ranging in age from zero (fledgling) to 30 years of age, showing a mean error of 2.24 ± 0.17 years between the estimated and real age across the population. This is the first development of an epigenetic clock using multiplex PCR sequencing in a bird. This method enables demography to be measured with relative accuracy in a single sampling trip. This technique can provide information for emerging demographic risks that can mask declines in long-lived seabird populations and be applied to other Pterodroma populations.

ANALISIS PERBANDINGAN HEADWAY DAN METODE PEMBAYARAN PADA JAKARTA MASS RAPID TRANSIT (MRT JAKARTA) DAN SINGAPORE MASS RAPID TRANSIT (MRT SINGAPURA)

The global population growth increased by 0.88% at the end of 2022 compared to the previous year. Jakarta and Singapore, as two densely populated areas in Southeast Asia, need to pay extra attention to the need for infrastructure, including adequate transportation systems. One of the prominent transportation modes in both regions is Mass Rapid Transit (MRT). MRT is an urban rail-based transportation mode aimed at providing regular and sustainable public services. The MRT system excels in capacity, speed, and reliability compared to other transportation modes, as it operates on fully separated tracks. Despite both regions having MRT systems, there are differences in several aspects. This research is conducted using a qualitative method, applying techniques such as the analysis of literature. The differing aspects between the Jakarta MRT and the Singapore MRT are headway (time between trains) and payment methods. The Singapore MRT has a smaller headway compared to the Jakarta MRT. The shorter the time, the better the service. In terms of payment methods, the Singapore MRT predominantly implements a cardless payment system, in contrast to the Jakarta MRT. The Jakarta MRT still offers the purchase of Single Trip Tickets and Multi Trip Tickets.

Smart Data Harvesting in Cache-Enabled MANETs: UAVs, Future Position Prediction, and Autonomous Path Planning

The task of gathering data from nodes within mobile ad-hoc wireless sensor networks presents an enduring challenge. Conventional strategies employ customized routing protocols tailored to these environments, with research focused on refining them for improved efficiency in terms of throughput and energy utilization. However, these elements are interconnected, and enhancements in one often come at the expense of the other. An alternative data collection approach involves the use of Unmanned Aerial Vehicles (UAVs). In contrast to traditional methods, UAVs directly collect data from mobile nodes, bypassing the need for routing. While existing research predominantly addresses static nodes, this paper proposes an evolutionary based, innovative path selection approach based on future position prediction of caching enabled mobile ad-hoc wireless sensor network nodes for UAV data collection, aimed at maximizing node encounters and gathering the most valuable information in a single trip. The proposed technique is evaluated for different movement models and parameter configurations.

Advancing clinical trial equity through integration of telehealth and decentralized treatment.

Innovative strategies to increase clinical trial accessibility and equity are needed. We conducted a retrospective review of a phase II investigator-initiated trial to determine whether the modification of clinical trial design to decentralize study treatment can improve trial accessibility among underrepresented groups. Sociodemographic characteristics, including area deprivation indices, as well as study site travel distance, time, and costs were compared between enrolled participants who received chemotherapy locally and participants who did not. Participants who received chemotherapy locally lived substantially farther from the study site (median = 95.90 vs 25.20 miles, P = .004), faced a greater time burden traveling to the study site (median = 115.00 vs 34.00 minutes, P = .002), and had higher travel-related costs for a single trip to the study site (median = $62.81 vs $16.51, P = .004). This study highlights opportunities for alleviating financial and time burdens associated with clinical trial participation, promoting equity in clinical research. Trial Registration: ClinicalTrials.gov identifier: NCT04380337.

Spaycations: A Qualitative Study of Veterinarians’ Motivations And Perceived Impacts of Remote Volunteer Spay Neuter

Increasingly, veterinarians skilled in High Quality High Volume Spay Neuter (HQHVSN) are invited to volunteer their surgical services in distant low-resource communities on trips that have become casually known as “spaycations.” While these trips are numerous, there is little research on veterinarians’ motivations for participating and their perceptions of the impacts these clinics have on communities they visit. The current study was open to veterinarians who work in or are trained in HQHVSN whether or not they had been on a spaycation trip. For the purpose of this study, a spaycation is defined as an unpaid or minimally paid trip from a high resource area to a low or moderate resource country or area to provide spay neuter services that is organized by someone other than the individual surgeon. Forty-one veterinarians responded to an electronic questionnaire containing open-ended questions relating to their thoughts and experiences regarding spaycations and their impacts on the volunteer veterinarians as well as on the animals, clients, communities, veterinary practitioners, and animal populations in the areas visited. A reflexive thematic analysis was conducted in which the veterinarians’ responses were coded inductively for semantic themes using a critical realist approach. Respondents had participated in a variety of spaycations around the world over the past 20 years. Most responding veterinarians were motivated by a desire to make a difference and give back to communities in need as well as the desire to travel and to experience other cultures. Many enjoyed bonding with and learning from other vets and team members on the spaycation, and said that while the trips were exhausting they were also paradoxically energizing, and that they renewed their professional passion. Many veterinarians were concerned by the financial and time commitments associated with participating in spaycations, and these costs had prevented some veterinarians from participating. Further reasons for not participating in spaycations included concerns about stress and burnout and about the continual expectation for veterinarians to volunteer their time. Some veterinarians presented concerns about spaycations producing damaging interactions with the local communities including cultural misunderstandings, distrust, the creation of dependence, colonialism, and White Savior syndrome. Local involvement in the spay neuter event varied, with some events entirely planned and staffed locally and involving training and mentorship of local veterinary professionals and students, while other spaycations included little local involvement. Veterinarians varied in their estimation of the animal population impact of the spaycation and agreed that recurrent or ongoing interventions are necessary for appreciable and sustainable population impacts, but that health impacts on individual animals and their families were important and visible even after a single trip. Thematic analysis identified three main themes, HQHVSN is a special skill set, Colonialism and Cost and Value. Spaycations are a unique way for HQHVSN veterinarians to use their distinctive skills in communities of need. The compelling nature of these trips necessitates conscientious and culturally-sensitive leadership and planning to provide safe, sustainable, community-centered programs with a focus on long-term solutions.

The Traveling Trucker Problem

This paper documents three new stylized facts showing that truckers in Colombia frequently choose to make complex chains of shipments in a single trip before returning home. It then provides a new model of optimal trucker trip-chaining with a general geography that is consistent with these facts.

Elevating Innovation: Unveiling the Twin Traction Method for a 50-Ton Load Capacity Elevator in Building and Construction Applications

Most commercial elevators for buildings exceeding four stories use a cable-driven traction system. Typically, a single traction machine operates by hoisting the main cable on a traction sheave, thus vertically transporting the elevator car through rotational motion of the sheave. This research introduces a groundbreaking advancement aimed at elevating loading capacity to an unprecedented 50 tons—the highest known in the world. The innovation involves the development of a twin traction system, wherein two traction machines collaborate to lift the elevator. This novel elevator system has demonstrated remarkable capabilities, showcasing the ability to transport up to 300 passengers in a single trip. The installation of this high-capacity elevator system has yielded substantial improvements in construction work efficiency and safety protocols, particularly in scenarios where cranes are traditionally used. The newly developed elevator could lift 50 tons of equipment 60 times a day, whereas the crane was limited to 8 times. The positive impact on labor is also noteworthy, with increased safety and health considerations, especially in adverse weather conditions. By eliminating the need for manual stair climbing, the well-being of the workforce is prioritized. Furthermore, the heightened productivity resulting from a significant reduction in wait times for conventional elevators is a key outcome of this transformative technology. This research not only unveils a groundbreaking twin traction system but also highlights its multifaceted features in enhancing efficiency, safety, and overall productivity in various industries.

Alchemical Enhanced Sampling with Optimized Phase Space Overlap.

An alchemical enhanced sampling (ACES) method has recently been introduced to facilitate importance sampling in free energy simulations. The method achieves enhanced sampling from Hamiltonian replica exchange within a dual topology framework while utilizing new smoothstep softcore potentials. A common sampling problem encountered in lead optimization is the functionalization of aromatic rings that exhibit distinct conformational preferences when interacting with the protein. It is difficult to converge the distribution of ring conformations due to the long time scale of ring flipping events; however, the ACES method addresses this issue by modeling the syn and anti ring conformations within a dual topology. ACES thereby samples the conformer distributions by alchemically tunneling between states, as opposed to traversing a physical pathway with a high rotational barrier. We demonstrate the use of ACES to overcome conformational sampling issues involving ring flipping in ML300-derived noncovalent inhibitors of SARS-CoV-2 Main Protease (Mpro). The demonstrations explore how the use of replica exchange and the choice of softcore selection affects the convergence of the ring conformation distributions. Furthermore, we examine how the accuracy of the calculated free energies is affected by the degree of phase space overlap (PSO) between adjacent states (i.e., between neighboring λ-windows) and the Hamiltonian replica exchange acceptance ratios. Both of these factors are sensitive to the spacing between the intermediate states. We introduce a new method for choosing a schedule of λ values. The method analyzes short "burn-in" simulations to construct a 2D map of the nonlocal PSO. The schedule is obtained by optimizing an alchemical pathway on the 2D map that equalizes the PSO between the λ intervals. The optimized phase space overlap λ-spacing method (Opt-PSO) leads to more numerous end-to-end single passes and round trips due to the correlation between PSO and Hamiltonian replica exchange acceptance ratios. The improved exchange statistics enhance the efficiency of ACES method. The method has been implemented into the FE-ToolKit software package, which is freely available.

Psychedelics: reconnecting the brain to heal the mind

Natural psychedelics such as magic mushrooms have a long history of human use of at least 7000 years. Their use underwent a resurgence in the 1950/1960s following the synthesis of LSD as a psychedelic and its use as a medicine with powerful therapeutic benefits. But because non-medical use led to massive cultural changes especially in young people, all psychedelics were banned globally in the early 1970s. Over the past 20 years, there has been a resurrection of psychedelic research. This has revealed their common modes of action as agonists (stimulators) of the serotonin 5-HT2A receptor in the brain and that this activity leads to profound alterations in neuro-circuitry, producing a more integrated and flexible pattern of activity. These brain changes found in healthy volunteers predicted utility in mental illnesses such as depression and addiction and subsequent trials revealed this to be true. A single psychedelic trip can lead to very long-lasting improvements in a range of mental illnesses. From these remarkable and consistent positive outcomes, it seems likely that psychedelic therapy will soon become widely approved in western medicine, as it has already been in Australia for treatment-resistant depression.

Sustainability Tools in Cultural Heritage: Life Cycle Assessment Examining Crates for Heritage Objects

ABSTRACT The Sustainability Tools in Cultural Heritage (STiCH) https://stich.culturalheritage.org project informs cultural heritage professionals about sustainable choices through life cycle assessment (LCA). This paper focuses on one study https://stich.culturalheritage.org/crates/ that examines the environmental impacts of transporting cultural heritage. The study models four crate types crates single trip, round trip, and reusable. For each crate, three major material categories (exterior, interior, and wrapping) were analyzed, giving each configuration an environmental profile. The study compares these crate options over their life cycles, including impacts from material production, transportation, and disposal. The results show that reusable crate have lower impacts than wooden crates across a broad range of environmental considerations. Transportation dominates reusable crates and is relatively less important for single-trip crates. For single-trip and round-trip crates, foams can be a major source of greenhouse gas emissions. Actions that would reduce impacts include reusing the crate itself or its disassembled components. Lowering the weight of the crate, possibly by using lighter materials for the crate shell, would reduce impacts from transport. These findings can encourage further research and exploration of sustainable materials that perform similarly to the items they replace.